REGIOSELECTIVELY SUBSTITUTED CELLULOSE ESTER BASED NEGATIVE BIREFRINGENT COMPENSATION FILMS HAVING IMPROVED WAVELENGTH DISPERSION

BACKGROUND OF THE INVENTION

Cellulose ester (“CE”) based films with negative birefringence are desirable for displays. However, negative birefringent CE films typically display normal wavelength dispersion, resulting in color shifts. To correct this problem, the films need to be tuned to exhibit improved wavelength dispersion, such as a flat or reverse wavelength dispersion. However, little is known on how to achieve flat or reverse wavelength dispersion in negative birefringent CE films. Applicants have disclosed stretched films comprising regioselectively substituted cellulose esters (“RCE”) and certain small molecule components that have improved wavelength dispersion. Some of the films have Z characteristics.

SUMMARY OF THE INVENTION

The present application discloses a film, comprising:

(1 ) a regioselectively substituted cellulose ester comprising:

(i) a plurality of aromatic-CO- substituents;

(ii) a plurality of a first unsaturated or saturated (Ci-e)alkyl-CO- substituents; and

(iii) a plurality of hydroxyl substituents; wherein: the degree of substitution for the hydroxyl (“DSOH”) is from 0.2 to 1 -1 , the cellulose ester has a C2 degree of substitution for the aromatic- CO- substituent (“C2DSArco”) which is from 0.15 to 0.8, the cellulose ester has a C3 degree of substitution for the aromatic- CO- substituent (“C3DSArco”) which is from 0.05 to 0.6, the cellulose ester has a C6 degree of substitution for the aromatic- CO- substituent (“C6DSArco”) which is from 0.05 to 0.6, the total degree of substitution for the aromatic-CO- substituent (“TotDSArco”) which is from 0.25 to 2.0, the aromatic-CO- is

(i) an (Ce-2o)aryl-CO-, wherein the aryl is unsubstituted or substituted by 1 -5 R ¹ ; or

(ii) a heteroaryl-CO-, wherein the heteroaryl is a 5- to 10-membered ring having 1 - to 4- heteroatoms chosen from N, O, or S, and wherein the heteroaryl is unsubstituted or substituted by 1 -5 R ¹ ; and

(2) a component A that is wherein: ring A is an (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; ring B is (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 - 4 heteroatoms chosen from N, O, or S; ring C is (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 - 4 heteroatoms chosen from N, O, or S; each R ¹ is independently saturated or unsaturated (Ci-2o)alkyl; saturated or unsaturated halo(Ci-2o)alkyl; saturated or unsaturated (Ci-2o)alkoxy; saturated or unsaturated halo(Ci- 2o)alkoxy; (Ce-2o)aryl unsubstituted or substituted by 1 -5 alkyl, haloalkyl, alkoxy, haloalkoxy, halo; 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; or -CH ₂ C(O)-R ³ ;

R ² is independently hydrogen, saturated or unsaturated (Ci-2o)alkyl, or saturated or unsaturated halo(Ci-2o)alkyl; each R ³ is independently saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, (Ce-2o)aryl, or 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S, wherein the aryl or heteroaryl are unsubstituted or substituted by 1 -5 R ⁶ ; each R ⁴ is independently saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated hetero(Ci-2o)alkyl containing 1 -2 heteroatoms chosen from N, O or S, saturated or unsaturated (Ci-2o)alkyl-CO- (Ci-2o)alkyl, , saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated halo(Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO- (Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, (Ci- 2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, (Ce-2o)aryl unsubstituted or substituted with 1 -5 R ⁶ , or 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S unsubstituted or substituted with 1 -5 R ⁶ , wherein each of the groups is unsubstituted or substituted by 1 - 3 hydroxyl, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl-, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci- 2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C<i- 2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci- 2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, unsubstituted or substituted (Ce-2o)aryl, or unsubstituted or substituted 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; each R ⁶ is independently hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated halo(Ci- 2o)alkoxy, halo, (Ce-2o)aryl, 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S, saturated or unsaturated hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci- 2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci- 2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO, saturated or unsaturated (Ci- 2o)alkyl-0-CO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl- COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci- 2o)alkyl-COO-(Ci-2o)alkyl, or (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci- 2o)alkyl, wherein each of the groups is unsubstituted or substituted by 1 -5 R ⁷ ; each R ⁷ is independently hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated hydroxy(Ci- 2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (C1 - 20)alkyl-O-CO, saturated or unsaturated (Ci-2o)alkoxy-(Ci- 2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkoxy-(C1 -20)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-0-CO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-0- CO-(Ci-2o)alkoxy; each R ⁹ is independently R ⁴ -O-, hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated hetero(Ci- 2o)alkyl containing 1 -2 heteroatoms chosen from N, O or S, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci- 2o)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-0-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-0- CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci- 2o)alkyl-COO-(Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci- 2o)alkyl, (Ce-io)aryl unsubstituted or substituted with 1 -5 R ⁶ , 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S unsubstituted or substituted with 1 -5 R ⁶ , wherein each of the groups are unsubstituted or substituted by 1 -3 hydroxy, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy, or saturated or unsaturated halo(Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl-, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci- 2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C<i- 2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci- 2o)alkyl, or (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, unsubstituted or substituted (Ce-2o)aryl, or unsubstituted or substituted 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; each n is independently 0, 1 , 2, 3, 4, or 5; each m is independently 0, 1 , 2, 3, 4, or 5; and k is independently 0, 1 , 2, 3, or 4, wherein: component A is present at less than 30 wt %, based on the total weight of the film, the film exhibits a R _e (589 nm) that is from -100 nm to -350 nm, the film exhibits a Rth(589 nm) that is from -100 nm to 100 nm, the film exhibits a ratio of R _e (450 nm)/R _e (550 nm) that is 0.7 to 1 .20, the film exhibits a ratio of R _e (650 nm)/R _e (550 nm) that is 0.9 to 1 .25, the film exhibits a [[-Rth(589 nm)/R _e (589 nm)] + 0.5] (“N _z “) that is from 0.2 to 0.8, each Rth(589 nm) is the out-of-plane retardation measured at 589 nm, each R _e (589 nm), R _e (450 nm), R _e (550 nm) is the in-plane retardation measured at 589 nm, 450 nm, and 550 nm, respectively, and the film is stretched.

BRIEF DESCRIPTION OF THE FIGURES

The present application makes reference to the following figures, wherein: Figure 1 provides a schematic representation for retardation films stretched along one direction (x direction). Figure 2 provides diagrams for the modes for wavelength dispersion in compensation films: (a) normal wavelength dispersion, (b) flat wavelength dispersion, and (c) reverse wavelength dispersion.

DETAILED DESCRIPTION OF THE INVENTION

The present invention may be understood more readily by reference to the following detailed description of the invention and the examples provided therein. It is to be understood that this invention is not limited to the specific methods, formulations, and conditions described, as such may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects of the invention only and is not intended to be limiting.

Definitions

In this specification and in the claims that follow, reference will be made to a number of terms, which shall be defined to have the following meanings.

Values may be expressed as “about” or “approximately” a given number. Similarly, ranges may be expressed herein as from “about” one particular value and/or to “about” or another particular value. When such a range is expressed, another aspect includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another aspect.

As used herein, the terms “a,” “an,” and “the” mean one or more.

As used herein, the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination.

As used herein, the terms “comprising,” “comprises,” and “comprise” are open-ended transition terms used to transition from a subject recited before the term to one or more elements recited after the term, where the element or elements listed after the transition term are not necessarily the only elements that make up the subject.

As used herein, the terms “having,” “has,” and “have” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.

As used herein, the terms “including,” “includes,” and “include” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.

Regioselectively substituted cellulose esters suitable for use in making optical films can comprise a plurality of alkyl-acyl or alkyl-CO- substituents, a plurality of aryl-acyl or aryl-CO- substituents, heteroaryl-acyl or heteroaryl-CO- substituents. As used herein, the term “acyl substituent” or “R-CO-" shall denote a substituent having the structure:

Such acyl or R-CO- groups in cellulose esters are generally bound to the pyranose ring of the cellulose via an ester linkage (i.e., through an oxygen atom).

Aromatic-CO- is an acyl substituent with an aromatic containing ring system. Examples include aryl-CO- or heteroaryl-CO-. Specific examples include benzoyl, naphthoyl, and furoyl, each being unsubstituted or substituted.

As used herein, the term “aryl-acyl” substituent shall denote an acyl substituent where “R” is an aryl group. As used herein, the term “aryl” shall denote a univalent group formed by removing a hydrogen atom from a ring carbon in an arene (i.e., a mono- or polycyclic aromatic hydrocarbon). In some cases the aryl-acyl group is preceded by the carbon units: For example, (Cs- 6)aryl-acyl, (Ce-i2)aryl-acyl, or (Ce-2o)aryl-acyl. Examples of aryl groups suitable for use in various embodiments include, but are not limited to, phenyl, benzyl, tolyl, xylyl, and naphthyl. Such aryl groups can be substituted or unsubstituted.

As used herein, the term “alkyl-acyl” shall denote an acyl substituent where “R” is an alkyl group. As used herein, the term “alkyl” shall denote a univalent group formed by removing a hydrogen atom from a non-aromatic hydrocarbon, and may include heteroatoms. Alkyl groups suitable for use herein can be straight, branched, or cyclic, and can be saturated or unsaturated. Alkyl groups suitable for use herein include any (C1-20), (C1-12), (C1-5), or (C1-3) alkyl groups. In various embodiments, the alkyl can be a C1-5 straight chain alkyl group. In still other embodiments, the alkyl can be a C1-3 straight chain alkyl group. Specific examples of suitable alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, decyl, dodecyl, cyclopentyl, and cyclohexyl groups. Examples of alkyl-acyl groups include acetyl, propionyl, butyryl, and the like.

“Haloalkyl” means an alkyl substituent where at least one hydrogen is replaced with a halogen group. The carbon units in the haloalkyl group is often included; for example halo(Ci-e)alkyl. The haloalkyl group can be straight or branched. Nonlimiting examples of haloalkyl include chloromethyl, trifluoromethyl, dibromoethyl and the like.

“Heteroalkyl” means an alkyl wherein one or more of the carbon atoms are replace with a heteroatoms such as for example N, O, or S.

“Heteroaryl” means an aryl where at least one of the carbon units in the aryl ring is replaced with a heteroatom such as O, N, and S. The heteroaryl is ring can be monocyclic or polycyclic. Often the units making up the heteroaryl ring system is include; for example a 5- to 20-membered ring system. A 5-membered heteroaryl means a ring system having five atoms forming the heteroaryl ring. Nonlimiting examples of heteroaryl include pyridinyl, quinolinyl, pyrimidinyl, thiophenyl and the like.

“Alkoxy” means alkyl-O- or an alkyl group terminally attached to an oxygen group. Often the carbon units are included; for example (Ci-e)alkoxy. Nonlimiting examples of alkoxy include Methoxy, ethoxy, propoxy and the like.

“Haloalkoxy” means alkoxy where at least one of the hydrogens is replace with a halogent. Often the carbon units are included; for example halo(Ci- e)alkoxy. Nonlimiting examples of haloalkoxy include trifluoromethoxy, bromomethoxy, 1 -bromo-ethoxy and the like.

“Halo” means halogen such as fluoro, chloro, bromo, or iodo.

“Degree of Substitution” is used to describe the substitution level of the substituents of the substituents per anhydroglucose unit (“AGU”). Generally, conventional cellulose contains three hydroxyl groups in each AGU that can be substituted. Therefore, the DS can have a value between 0 and 3. However, low molecular weight cellulose mixed esters can have a total degree of substitution slightly above 3 from end group contributions. Low molecular weight cellulose mixed esters are discussed in more detail subsequently in this disclosure. Because DS is a statistical mean value, a value of 1 does not assure that every AGU has a single substituent. In some cases, there can be unsubstituted anhydroglucose units, some with two and some with three substituents, and more often than not the value will be a noninteger. Total DS is defined as the average number of all of substituents per anhydroglucose unit. The degree of substitution per AGU can also refer to a particular substituent, such as, for example, hydroxyl, acetyl, butyryl, or propionyl. Additionally, the degree of substitution can specify which carbon unit of the anhydroglucose unit.

When the degree of substitution refers to hydroxyl, i.e, DSOH, the reference is to the average hydroxyl groups per anhydroglucose that are not substituted. As a result, DSOH is not used in the calculation of the total degree of substitution.

Numerical Ranges

The present description uses numerical ranges to quantify certain parameters relating to the invention. It should be understood that when numerical ranges are provided, such ranges are to be construed as providing literal support for claim limitations that only recite the lower value of the range as well as claim limitations that only recite the upper value of the range. For example, a disclosed numerical range of 10 to 100 provides literal support for a claim reciting “greater than 10” (with no upper bounds) and a claim reciting “less than 100” (with no lower bounds).

The present description uses specific numerical values to quantify certain parameters relating to the invention, where the specific numerical values are not expressly part of a numerical range. It should be understood that each specific numerical value provided herein is to be construed as providing literal support for a broad, intermediate, and narrow range. The broad range associated with each specific numerical value is the numerical value plus and minus 60 percent of the numerical value, rounded to two significant digits. The intermediate range associated with each specific numerical value is the numerical value plus and minus 30 percent of the numerical value, rounded to two significant digits. The narrow range associated with each specific numerical value is the numerical value plus and minus 15 percent of the numerical value, rounded to two significant digits. For example, if the specification describes a specific temperature of 62 °F, such a description provides literal support for a broad numerical range of 25 °F to 99 °F (62 °F +/- 37 °F), an intermediate numerical range of 43 °F to 81 °F (62 °F +/- 19 °F), and a narrow numerical range of 53 °F to 71 °F (62 °F +/- 9 °F). These broad, intermediate, and narrow numerical ranges should be applied not only to the specific values, but should also be applied to differences between these specific values. Thus, if the specification describes a first pressure of 110 psia and a second pressure of 48 psia (a difference of 62 psi), the broad, intermediate, and narrow ranges for the pressure difference between these two streams would be 25 to 99 psi, 43 to 81 psi, and 53 to 71 psi, respectively.

Throughout this application, where patents or publications are referenced, the disclosures of these references in their entireties are intended to be incorporated by reference into this application, to the extent they are not inconsistent with the present invention, in order to more fully describe the state of the art to which the invention pertains.

Compensation films are important to improve the viewing quality of liquid crystal displays (LCD) and organic light emitting diode displays (OLED). For isotropic materials, the refractive indices are the same regardless of the polarization status of the entering light. As materials become oriented and anisotropic, the refractive indices become dependent on the directions. The difference between refractive indices along different directions is birefringence. For polymer films, stretching around or above the glass transition temperature is usually required to make polymer oriented and lead to birefringence. Birefringence of compensation films are critical for the display qualities. It is widely used in-plane birefringence (An _e ) and out-of-plane birefringence (Anth) to characterize the compensation films. For a film stretched along x direction, An _e and Anth are defined by the following equations. Arie = (nx - n _y ) nth =[n _z - (nx + n _y )/2]

Where n _x is the refractive index along the stretching direction in the film plane while n _y is the refractive index perpendicular to the stretching direction in the film plane, and n _z is the refractive index perpendicular to the film plane. For the majority of polymer materials, when the film is stretched along on direction (x direction), the refractive index along stretching direction (n _x ) is larger than the refractive index orthogonal to the stretching direction (n _y ) in the film plane, i.e. An _e = (n _x - n _y ) is larger than zero, and the stretching direction is the slow axis in the film plane. Those polymer materials have intrinsic positive birefringence. Some polymer materials have intrinsic negative birefringence. When those materials are stretched along one direction (x direction), and the refractive index along stretching direction (n _x ) is smaller than the refractive index orthogonal to the stretching direction (n _y ) in the film plane, i.e. An _e = (n _x - n _y ) is smaller than zero, and the stretching direction is the fast axis in the film plane.

Correspondingly, in-plane retardation (R _e ) and out-of-plane retardation (Rth) are defined as the products of An _e with the thickness of the compensation film (d) and Anth with d.

R _e = (n _x - n _y )*d

Rth = [n _z - (n _x + n _y )/2]*d

Where for polymer films with positive birefringence, n _x is the refractive index along slow axis in the film plane, n _y is the refractive index along fast axis in the film plane, and n _z is the refractive index perpendicular to the film plane; for films with negative birefringence, n _x is the refractive index along fast axis in the film plane, n _y is the refractive index along slow axis in the film plane, and n _z is the refractive index perpendicular to the film plane.

In addition, Nz coefficient is also widely used, as defined by the following equation.

N _z = (nx — n _z )/ (nx — n _y ) = -Rth/Re + 0.5 Where for polymer films with positive birefringence, n _x is the refractive index along slow axis in the film plane, n _y is the refractive index along fast axis in the film plane, and n _z is the refractive index perpendicular to the film plane; for films with negative birefringence, n _x is the refractive index along fast axis in the film plane, n _y is the refractive index along slow axis in the film plane, and n _z is the refractive index perpendicular to the film plane.

Depending on the application field, various compensation films have been developed, such as biaxial films where all of three refractive indices are different (n _x n _y , n _x n _z , and n _y n _z ), and uniaxial films where two of the refractive indices are very close but different from the third one (n _x = n _y n _z , n _x = n _z n _y , n _y = n _z n _x ). For uniaxial films, there are A+ films, A- films, C+ films and C- films, which are defined by the following equations.

A+: n _x > n _y = n _z ; N _z coefficient = 1 A-: n _x < n _y = n _z ; N _z coefficient = 1 C+: n _x = n _y < n _z ; N _z coefficient = °° C-: n _x = n _y > n _z ; N _z coefficient = °°

For biaxial films, one important category of biaxial films is Z film, where n _x > n _z > n _y or n _y > n _z > n _x ; most specifically, biaxial films with n _z = (n _x +n _y )/2, which will lead to N _z coefficient equal to 0.5, is especially interesting.

In addition, wavelength dispersion is also important for compensation films. Wavelength dispersion relates to the relationship of birefringence or retardation with wavelength of light. R _e (450 nm)/R _e (550 nm), R _e (650 nm)/R _e (550 nm), Rth(450 nm)/Rth(550 nm) and Rth(650 nm)/Rth(550 nm), which indicates the ratio of retardation at 450 nm, 550 nm and 650 nm, are widely used to characterize the wavelength dispersion. As shown in Figure 2, normal wavelength dispersion means the birefringence or retardation of compensation films is larger at shorter wavelength with Re(450 nm)/Re(550 nm) > 1 , Re(650 nm)/Re(550 nm) < 1 , a flat wavelength dispersion means the birefringence or retardation of compensation films is constant over the wavelength range studied with Re(450 nm)/Re(550 nm) = 1 , Re(650 nm)/Re(550 nm) = 1 , and reverse wavelength dispersion means the birefringence or retardation of compensation films is smaller at shorter wavelength, with Re(450 nm)/Re(550 nm) < 1 , Re(650 nm)/Re(550 nm) > 1 . Reverse wavelength dispersion is highly desired as it can significantly depress the color shift of displays.

Cellulose esters have been widely used for compensation films. They have many advantages compared to other materials such as polycarbonate and poly(cyclic olefins). The majority of cellulose esters based compensation films are made from cellulose esters with aliphatic acyl substituents, such as cellulose acetate, cellulose acetate propionate and cellulose acetate butyrate. The acyl substituents are randomly distributed. And the birefringence of those compensation films is usually positive with n _x > n _y , where n _x is the refractive index along the stretching direction in the film plane while n _y is the refractive index perpendicular to the stretching direction in the film plane. Cellulose esters with negative birefringence (n _x < n _y ) can be achieved by adding aromatic acyl substituents and controlling the positions of the aromatic acyl substituents or long aliphatic acyl substituents. One problem with compensation films made from cellulose esters with negative birefringence is the normal wavelength dispersion of those compensation films with R _e (450 nm)/R _e (550 nm) > 1 and R _e (650 nm)/R _e (550 nm) < 1 . There is no commercial product based on cellulose esters with negative birefringence and flat or reverse wavelength dispersion. More specifically, there is no commercial product for Z film based on cellulose esters with negative birefringence and flat or reverse wavelength dispersion.

In various embodiments, regioselectively substituted cellulose esters can be employed in which the aryl-acyl substituent is preferentially installed at C2 and C3 of the pyranose ring. Regioselectivity can be measured by determining the relative degree of substitution (“RDS”) at C6, C3, and C2 in the cellulose ester by carbon 13 NMR spectroscopy (Macromolecules, 1991 , 24, 3050-3059). In the case of one type of acyl substituent or when a second acyl substituent is present in a minor amount (DS < 0.2), the RDS can be most easily determined directly by integration of the ring carbons. When 2 or more acyl substituents are present in similar amounts, in addition to determining the ring RDS, it is sometimes necessary to fully substitute the cellulose ester with an additional substituent in order to independently determine the RDS of each substituent by integration of the carbonyl carbons. In conventional cellulose esters, regioselectivity is generally not observed and the RDS ratio of C6/C3, C6/C2, or C3/C2 is generally near 1 or less. In essence, conventional cellulose esters are random copolymers. In contrast, when adding one or more acylating reagents to cellulose dissolved in an appropriate solvent, the C6 position of cellulose is acylated much faster than C2 and C3 positions. Consequently, the C6/C3 and C6/C2 ratios are significantly greater than 1 , which is characteristic of a 6,3- or 6,2-enhanced regioselectively substituted cellulose ester.

Examples of regioselectively substituted cellulose esters and their methods for preparation are described in US 2010/0029927, US 2010/0267942, and US 8,354,525; the contents of which are hereby incorporated by reference. In general, these applications concern preparation of cellulose esters by dissolution of cellulose in an ionic liquid, which is then contacted with an acylating reagent. Accordingly, for various embodiments of the present invention, two general methods can be employed for preparing regioselectively substituted cellulose esters. In one method, regioselectively substituted cellulose esters can be prepared using a staged addition by first contacting the cellulose solution with one or more alkyl acylating reagents followed by contacting the cellulose solution with an aryl-acylating reagent at a contact temperature and contact time sufficient to provide a cellulose ester with the desired degree of substitution (“DS”) and degree of polymerization (“DP”). In this staged addition, the acyl groups containing alkyl groups can be preferentially installed at C6 and the acyl groups containing an aryl group can be preferentially installed at C2 and/or C3. Alternatively, the regioselectively substituted cellulose esters can be prepared by contacting the cellulose solution with one or more alkyl acylating reagents followed by isolation of the alkyl ester in which the acyl groups containing alkyl groups are preferentially installed at C6. The alkyl ester can then be dissolved in any appropriate organic solvent and contacted with an aryl-acylating reagent which can preferentially install the acyl groups containing an aryl group at C2 and/or C3 at a contact temperature and contact time sufficient to provide a cellulose ester with the desired degree of substitution (“DS”) and degree of polymerization (“DP”).

Examples of regioselectively substituted cellulose esters and their methods for preparation are also described in US20170306054 and US20170307796; the contents of which are hereby incorporated by reference. In general, these applications concern preparation of cellulose esters by dissolution of starting cellulose esters with low degree of substitution (DS) in appropriate organic solvents, which is then contacted with an acylating reagent. Accordingly, for various embodiments of the present invention, two general methods can be employed for preparing regioselectively substituted cellulose esters. In one method, regioselectively substituted cellulose esters can be prepared using a staged addition by first contacting the starting cellulose ester solution with one or more alkyl acylating reagents followed by contacting the cellulose solution with an aryl-acylating reagent at a contact temperature and contact time sufficient to provide a cellulose ester with the desired degree of substitution (“DS”) and degree of polymerization (“DP”). In this staged addition, the acyl groups containing alkyl groups can be preferentially installed at C6 and the acyl groups containing an aryl group can be preferentially installed at C2 and/or C3. Alternatively, the regioselectively substituted cellulose esters can be prepared by contacting the starting cellulose ester solution with one or more alkyl acylating reagents followed by isolation of the alkyl ester in which the acyl groups containing alkyl groups are preferentially installed at C6. The alkyl ester can then be dissolved in any appropriate organic solvent and contacted with an aryl- acylating reagent which can preferentially install the acyl groups containing an aryl group at C2 and/or C3 at a contact temperature and contact time sufficient to provide a cellulose ester with the desired degree of substitution (“DS”) and degree of polymerization (“DP”).

The cellulose esters thus prepared generally comprise the following structure: where R ² , R ³ , and R ⁶ are hydrogen (with the proviso that R ² , R ³ , and R ⁶ are not hydrogen simultaneously), alkyl-acyl groups, and/or aryl-acyl groups (such as those described above) bound to the cellulose via an ester linkage.

The degree of polymerization (“DP”) of the cellulose esters prepared by these methods can be at least 10. In other embodiments, the DP of the cellulose esters can be at least 50, at least 100, or at least 250. In other embodiments, the DP of the cellulose esters can be in the range of from about 5 to about 100, or in the range of from about 10 to about 50.

Acylating reagents suitable for use herein can include, but are not limited to, alkyl or aryl carboxylic anhydrides, carboxylic acid halides, and/or carboxylic acid esters containing the above-described alkyl or aryl groups suitable for use in the acyl substituents of the regioselectively substituted cellulose esters described herein. Examples of suitable carboxylic anhydrides include, but are not limited to, acetic anhydride, propionic anhydride, butyric anhydride, pivaloyl anhydride, benzoic anhydride, and naphthoyl anhydride. Examples of carboxylic acid halides include, but are not limited to, acetyl, propionyl, butyryl, pivaloyl, benzoyl, and naphthoyl chlorides or bromides. Examples of carboxylic acid esters include, but are not limited to, acetyl, propionyl, butyryl, pivaloyl, benzoyl and naphthoyl methyl esters. In one or more embodiments, the acylating reagent can be one or more carboxylic anhydrides selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, pivaloyl anhydride, benzoyl anhydride, and naphthoyl anhydride.

Stretched Films

The present application discloses a film, comprising: (1 ) a regioselectively substituted cellulose ester comprising: (i) a plurality of aromatic-CO- substituents;

(ii) a plurality of a first unsaturated or saturated (Ci-e)alkyl-CO- substituents; and

(iii) a plurality of hydroxyl substituents; wherein: the degree of substitution for the hydroxyl (“DSOH”) is from 0.2 to 1.1 , the cellulose ester has a C2 degree of substitution for the aromatic-CO- substituent (“C2DSArco”) which is from 0.15 to 0.8, the cellulose ester has a C3 degree of substitution for the aromatic-CO- substituent (“C3DSArco”) which is from 0.05 to 0.6, the cellulose ester has a C6 degree of substitution for the aromatic-CO- substituent (“C6DSArco”) which is from 0.05 to 0.6, the total degree of substitution for the aromatic-CO- substituent (“TotDSArco”) which is from 0.25 to 2.0, the aromatic-CO- is an (i) (Ce-2o)aryl-CO-, wherein the aryl is unsubstituted or substituted by 1 -5 R ¹ ; or (ii) a heteroaryl-CO-, wherein the heteroaryl is a 5- to 10-membered ring having 1 - to 4- heteroatoms chosen from N, O, or S, and wherein the heteroaryl is unsubstituted or substituted by 1 -5 R ¹ ; and (2) a component A that is

, wherein: ring A is an (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; ring B is (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; ring C is (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; each R ¹ is independently saturated or unsaturated (Ci-2o)alkyl; saturated or unsaturated halo(Ci-2o)alkyl; saturated or unsaturated (Ci-2o)alkoxy; saturated or unsaturated halo(Ci-2o)alkoxy; (Ce-2o)aryl unsubstituted or substituted by 1 -5 alkyl, haloalkyl, alkoxy, haloalkoxy, halo; 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; or -CH2C(O)-R ³ ; R ² is independently hydrogen, saturated or unsaturated (Ci-2o)alkyl, or saturated or unsaturated halo(Ci-2o)alkyl; each R ³ is independently saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, (Ce-2o)aryl, or 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S, wherein the aryl or heteroaryl are unsubstituted or substituted by 1 -5 R ⁶ ; each R ⁴ is independently saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated hetero(Ci-2o)alkyl containing 1 -2 heteroatoms chosen from N, O or S, saturated or unsaturated (Ci-2o)alkyl-CO-(Ci-2o)alkyl, , saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated halo(Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C<i- 2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl- 0-CO-(Ci-2o)alkyl, (Ce-2o)aryl unsubstituted or substituted with 1 -5 R ⁶ , or 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S unsubstituted or substituted with 1 -5 R ⁶ , wherein each of the groups is unsubstituted or substituted by 1 -3 hydroxyl, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl-, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C(i-2o)alkyl, saturated or unsaturated (Ci- 2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO- (Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, unsubstituted or substituted (Ce-2o)aryl, or unsubstituted or substituted 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; each R ⁶ is independently hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated halo(Ci-2o)alkoxy, halo, (Ce-2o)aryl, 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S, saturated or unsaturated hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C<i- 2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, or (Ci-2o)alkoxy-(Ci- 2o)alkyl-0-CO-(Ci-2o)alkyl, wherein each of the groups is unsubstituted or substituted by 1 -5 R ⁷ ; each R ⁷ is independently hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated hydroxy(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-hydroxy(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl- CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci- 2o)alkoxy, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci- 2o)alkyl-COO, saturated or unsaturated (C1 -20)alkyl-O-CO, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl- COO, saturated or unsaturated (Ci-2o)alkoxy-(C1 -20)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl- 0-CO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- (Ci-2o)alkyl-COO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl- 0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci- 2o)alkoxy; each R ⁹ is independently R ⁴ -O-, hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated hetero(Ci-2o)alkyl containing 1 - 2 heteroatoms chosen from N, O or S, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-0-CO-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci- 2o)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-0-(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- (Ci-2o)alkyl-COO-(Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, (Ce- w)aryl unsubstituted or substituted with 1 -5 R ⁶ , 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S unsubstituted or substituted with 1 -5 R ⁶ , wherein each of the groups are unsubstituted or substituted by 1 -3 hydroxy, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy, or saturated or unsaturated halo(Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci- 2o)alkyl-, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci- 2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- (Ci-2o)alkyl-COO-(Ci-2o)alkyl, or (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, unsubstituted or substituted (Ce-2o)aryl, or unsubstituted or substituted 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; each n is independently 0, 1 , 2, 3, 4, or 5; each m is independently 0, 1 , 2, 3, 4, or 5; and k is independently 0, 1 , 2, 3, or 4, wherein: component A is present at less than 30 wt %, based on the total weight of the film, the film exhibits a R _e (589 nm) that is from -100 nm to -350 nm, the film exhibits a Rth(589 nm) that is from -100 nm to 100 nm, the film exhibits a ratio of R _e (450 nm)/R _e (550 nm) that is 0.7 to 1.20, the film exhibits a ratio of R _e (650 nm)/R _e (550 nm) that is 0.9 to 1 .25, the film exhibits a [[-Rth(589 nm)/R _e (589 nm)] + 0.5] (“N _z “) that is from 0.2 to 0.8, each Rth(589 nm) is the out-of-plane retardation measured at 589 nm, each R _e (589 nm), R _e (450 nm), R _e (550 nm) is the in-plane retardation measured at 589 nm, 450 nm, and 550 nm, respectively, and the film is stretched.

In one embodiment or in combination with any other embodiment, the film is stretched at a temperature of from 100°C to 220°C. In one embodiment or in combination with any other embodiment, the film is stretched at a temperature of from 100°C to 150°C. In one embodiment or in combination with any other embodiment, the film is stretched at a temperature of from 100°C to 175°C. In one embodiment or in combination with any other embodiment, the film is stretched at a temperature of from 150°C to 200°C. In one embodiment or in combination with any other embodiment, the film is stretched at a temperature of from 125°C to 200°C. In one embodiment or in combination with any other embodiment, the film is stretched at a temperature of from 175°C to 200°C. In one embodiment or in combination with any other embodiment, the film is stretched at a temperature of from 125°C to 175°C. In one embodiment, the film is stretched at a temperature of from T _g - 30°C to Tg + 50°C, wherein T _g is the glass transition temperature of the film. In one embodiment or in combination with any other embodiment, R ⁹ is R ⁴ - O-. In one embodiment or in combination with any other embodiment, R ⁹ is saturated or unsaturated (Ci-2o)alkyl, (Ci-2o)alkyl-0-(Ci-2o)alkyl-, wherein the alkyl groups are saturated or unsaturated, or saturated or unsaturated (Ci-2o)alkyl-0- (Ci-2o)alkyl-0-.

In one embodiment or in combination with any other embodiment, R ⁹ is hydroxy, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated hetero(Ci-2o)alkyl containing 1 -2 heteroatoms chosen from N, O or S, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl- CO, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-0-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl- 0-CO-(Ci-2o)alkyl- (Ce-io)aryl, 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S, wherein each of the groups are unsubstituted or substituted by 1 -3 hydroxyl, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxyl, or saturated or unsaturated halo(Ci-2o)alkoxyl. saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci- 2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl-, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl- 0-CO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, or (Ci- 2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl.

In one embodiment or in combination with any other embodiment, the film exhibits a R _e (589 nm) that is from -120 nm to -350 nm. In one embodiment or in combination with any other embodiment, the film exhibits a R _e (589 nm) that is from -120 nm to -320 nm. In one embodiment or in combination with any other embodiment, the film exhibits a R _e (589 nm) that is from -120 nm to -175 nm. In one embodiment or in combination with any other embodiment, the film exhibits a R _e (589 nm) that is from -175 nm to -350 nm. In one embodiment or in combination with any other embodiment, the film exhibits a R _e (589 nm) that is from -208 nm to -262 nm.

In one embodiment or in combination with any other embodiment, the film exhibits a Rth(589 nm) that is from -100 nm to 0 nm. In one embodiment or in combination with any other embodiment, the film exhibits a Rth(589 nm) that is from -100 nm to 0 nm. In one embodiment or in combination with any other embodiment, the film exhibits a Rth(589 nm) that is from 0 nm to 100 nm. In one embodiment or in combination with any other embodiment, the film exhibits a Rth(589 nm) that is from -50 nm to 50 nm.

In one embodiment or in combination with any other embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm.

In one embodiment or in combination with any other embodiment, wherein the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 1 .05. In one embodiment or in combination with any other embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 0.85.

In one embodiment or in combination with any other embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of Re(450 nm)/Re(550 nm) is from 0.95 to 1 .02, and the ratio of R _e (650 nm)/R _e (550 nm) is from 0.95 to 1 .05, wherein the Re(450 nm), Re(550 nm), and Re(650 nm) are the in-plane retardations measured at 450 nm, 550 nm and 650 nm, respectively.

In one class of this embodiment, the Re(589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm. In one class of this embodiment, the Re(589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one embodiment or in combination with any other embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 0.95, and the ratio of R _e (650 nm)/R _e (550 nm) is from 0.97 to 1 .15.

In one class of this embodiment, the Re(589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm. In one class of this embodiment, the Re(589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one embodiment or in combination with any other embodiment, N _z is from -2.0 to 2.0.

In one class of this embodiment or in combination with any other class within this embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of R _e (450 nm)/R _e (550 nm) is from 0.95 to 1 .02, and the ratio of R _e (650 nm)/R _e (550 nm) is from 0.95 to 1 .05, wherein the Re(450 nm), Re(550 nm), and Re(650 nm) are the in-plane retardations measured at 450 nm, 550 nm and 650 nm, respectively.

In one subclass of this class, the R _e (589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm. In one subclass of this class, the R _e (589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one class of this embodiment or in combination with any other class within this embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 0.95, and the ratio of R _e (650 nm)/R _e (550 nm) is from 0.97 to 1.15.

In one subclass of this class, the R _e (589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm. In one subclass of this class, the Re(589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one class of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of Re(450 nm)/Re(550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (589 nm)/d (nm) multiplied by 1000 is from -6.0 to -0.5, and the ratio of Rth (589 nm)/ d (nm) multiplied by 1000 is from -1 .0 to 1 .0.

In one subclass of this embodiment, the ratio of R _e (450 nm)/ R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (589 nm)/d(nm) multiplied by 1000 is from -6.0 to -0.5, and the ratio of Rth (589 nm)/d(nm) multiplied by 1000 is from 0.15 to 4.2.

In one subclass of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 0.9, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of Re(650 nm)/Re(550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one embodiment or in combination with any other embodiment, N _z is from -1 .5 to 1 .5.

In one class of this embodiment or in combination with any other class within this embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of Re(450 nm)/Re(550 nm) is from 0.95 to 1 .02, and the ratio of R _e (650 nm)/R _e (550 nm) is from 0.95 to 1 .05, wherein the Re(450 nm), Re(550 nm), and Re(650 nm) are the in-plane retardations measured at 450 nm, 550 nm and 650 nm, respectively.

In one subclass of this class, the Re(589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm. In one subclass of this class, the Re(589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one class of this embodiment or in combination with any other class within this embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 0.95, and the ratio of R _e (650 nm) to R _e (550 nm) is from 0.97 to 1.15.

In one subclass of this class, the Re(589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm. In one subclass of this class, the Re(589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one class of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (589 nm)/d (nm) multiplied by 1000 is from -6.0 to -0.5, and the ratio of Rth(589 nm)/d (nm) multiplied by 1000 is from -1 .0 to 1 .0.

In one subclass of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (589 nm)/d (nm) multiplied by 1000 is from -6.0 to -0.5, and the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from 0.15 to 4.2.

In one subclass of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one class of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.ln one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 0.9, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one embodiment or in combination with any other embodiment, N _z is from 0.3 to 0.7.

In one class of this embodiment, wherein R _e (589 nm) is from -120 to -320 nm and Rth (589 nm) is from -60 to 60 nm.

In one class of this embodiment or in combination with any other class within this embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of Re(450 nm) /R _e (550 nm) is from 0.95 to 1 .02, and the ratio of R _e (650 nm) /R _e (550 nm) is from 0.95 to 1 .05, wherein the R _e (450 nm), Re(550 nm), and R _e (650 nm) are the in-plane retardations measured at 450 nm, 550 nm and 650 nm, respectively.

In one subclass of this class, the R _e (589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm. In one subclass of this class, the R _e (589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one class of this embodiment or in combination with any other class within this embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of R _e (450 nm) /R _e (550 nm) is from 0.75 to 0.95, and the ratio of R _e (650 nm) /R _e (550 nm) is from 0.97 to 1.15.

In one subclass of this class, the Re(589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm. In one subclass of this class, the Re(589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one class of this embodiment, the ratio of R _e (589 nm)/ d (nm) multiplied by 1000 is from -6.0 to -0.5, and the ratio of Rth (589 nm)/ d (nm) multiplied by 1000 is from -1 .8 to 1 .8.

In one subclass of this class, the ratio of R _e (450 nm) /R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (450 nm) /R _e (550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (589 nm)/d (nm) multiplied by 1000 is from -6.0 to -0.5, and the ratio of Rth (589 nm)/ d (nm) multiplied by 1000 is from -1 .0 to 1 .0.

In one subclass of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.ln one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from

1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 0.9, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from

1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one embodiment or in combination with any other embodiment, N _z is from 0.4 to 0.6.

In one class of this embodiment or in combination with any other class within this embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of Re(450 nm) /R _e (550 nm) is from 0.95 to 1 .02, and the ratio of R _e (650 nm) /R _e (550 nm) is from 0.95 to 1 .05, wherein the R _e (450 nm), Re(550 nm), and R _e (650 nm) are the in-plane retardations measured at 450 nm, 550 nm and 650 nm, respectively.

In one subclass of this class, the R _e (589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm. In one subclass of this class, the R _e (589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one class of this embodiment or in combination with any other class within this embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of Re(450 nm) /R _e (550 nm) is from 0.75 to 0.95, and the ratio of R _e (650 nm) /R _e (550 nm) is from 0.97 to 1 .15.

In one subclass of this class, the Re(589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm. In one subclass of this class, the Re(589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from

1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from

1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 0.9, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from

1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one embodiment or in combination with any other embodiment, N _z is from 0.8 to 1.2.

In one class of this embodiment, wherein R _e (589 nm) is from -120 to -320 nm and Rth (589 nm) is from 60 to 120 nm.

In one class of this embodiment or in combination with any other class within this embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of Re(450 nm) /R _e (550 nm) is from 0.95 to 1 .02, and the ratio of R _e (650 nm) /R _e (550 nm) is from 0.95 to 1 .05, wherein the R _e (450 nm), Re(550 nm), and R _e (650 nm) are the in-plane retardations measured at 450 nm, 550 nm and 650 nm, respectively.

In one subclass of this class, the R _e (589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm. In one subclass of this class, the R _e (589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm.

In one class of this embodiment or in combination with any other class within this embodiment, the R _e (589 nm) is from -120 nm to -320 nm, the Rth(589 nm) is from -60 nm to 60 nm, the ratio of Re(450 nm) /R _e (550 nm) is from 0.75 to 0.95, and the ratio of R _e (650 nm) /R _e (550 nm) is from 0.97 to 1.15.

In one subclass of this class, the R _e (589 nm) is from -120 nm to -160 nm, the Rth(589 nm) is from -30 nm to 30 nm. In one subclass of this class, the R _e (589 nm) is from -240 nm to -320 nm, the Rth(589 nm) is from -30 nm to 30 nm. In one class of this embodiment, the ratio of R _e (589 nm)/ d (nm) multiplied by 1000 is from -6.0 to -0.5, and the ratio of Rth (589 nm) and d (nm) multiplied by 1000 is from 0.15 to 4.2.

In one subclass of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (589 nm)/ d (nm) multiplied by 1000 is from -8.0 to -0.5, and the ratio of Rth (589 nm)/ d (nm) multiplied by 1000 is from 0.15 to 5.6.

In one subclass of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one subclass of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is from 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one sub-subclass of this subclass, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1.2, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (450 nm) /R _e (550 nm) is less than 0.9, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm) /R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one class of this embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one subclass of this class, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one embodiment or in combination with any other embodiment, the ratio of R _e (589 nm)/d(nm) multiplied by 1000 is from -6.0 to -0.5. In one class of this embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -3.0 to 3.0. In one class of this embodiment, the ratio of Rth (589 nm)/d(nm) multiplied by 1000 is from -2.0 to 2.0. In one class of this embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -1 .8 to 1 .8. In one class of this embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -1.0 to 1.0.

In one embodiment or in combination with any other embodiment, the ratio of R _e (589 nm)/d (nm) multiplied by 1000 is from -8.0 to -0.5. In one class of this embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -3.0 to 3.0. In one class of this embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -2.4 to 2.4. In one class of this embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -1 .8 to 1 .8. In one class of this embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -1.0 to 1.0.

In one embodiment or in combination with any other embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -3.0 to 3.0. In one embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -2.0 to 2.0. In one embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -1.8 to 1.8. In one embodiment, the ratio of Rth (589 nm)/d (nm) multiplied by 1000 is from -1 .0 to 1 .0.

In one embodiment or in combination with any other embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one embodiment or in combination with any other embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 1.0, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one embodiment or in combination with any other embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is less than 0.9, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one embodiment or in combination with any other embodiment, the ratio of R _e (450 nm)/R _e (550 nm) is 0.75 to 0.85, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one class of this embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm.

In one embodiment or in combination with any other embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 0.95, wherein the R _e (650 nm) is the inplane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one embodiment or in combination with any other embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is greater than 1 .0, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one embodiment or in combination with any other embodiment, the ratio of R _e (650 nm)/R _e (550 nm) is from 1 .10 to 1 .25, wherein the R _e (650 nm) is the in-plane retardation measured at 650 nm and R _e (550 nm) is the in-plane retardation measured at 550 nm. In one embodiment or in combination with any other embodiment, the film is uniaxially stretched, biaxially stretched, or stretched at angles. In one class of this embodiment, the film is uniaxially stretched or biaxially stretched. In one class of this embodiment, the film is uniaxially stretched. In one class of this embodiment, the film is biaxially stretched. In one class of this embodiment, the film is stretched at angles.

In one embodiment or in combination with any other embodiment, the film is stretched along the machine direction. In one embodiment or in combination with any other embodiment, the film is shrunk along the machine direction. In one embodiment or in combination with any other embodiment, the film is stretched along the transverse direction. In one embodiment or in combination with any other embodiment, the film is shrunk along the transverse direction.

In one embodiment or in combination with any other embodiment, the slow axis in the film plane forms an angle between 0° to 180° relative to the machine direction of the film. In one embodiment or in combination with any other embodiment, the slow axis in the film plane forms an angle between 0° to 90° relative to the machine direction of the film. In one embodiment or in combination with any other embodiment, the slow axis in the film plane forms an angle between 90° to 180° relative to the machine direction of the film. In one embodiment or in combination with any other embodiment, the slow axis in the film plane forms an angle between 45° to 145° relative to the machine direction of the film. In one embodiment or in combination with any other embodiment, the slow axis in the film plane forms an angle between 75° to 1 15° relative to the machine direction of the film.

In one embodiment or in combination with any other embodiment, the film comprises less than 10 wt% of an unsubstituted or substituted (2- hydroxyphenyl)(phenyl)methanone or an unsubstituted or substituted 2H- chromen-2-one. In one embodiment or in combination with any other embodiment, the film comprises less than 5 wt% of an unsubstituted or substituted (2-hydroxyphenyl)(phenyl)methanone or an unsubstituted or substituted 2H-chromen-2-one. In one embodiment or in combination with any other embodiment, the film comprises less than 1 wt% of an unsubstituted or substituted (2-hydroxyphenyl)(phenyl)methanone or an unsubstituted or substituted 2H-chromen-2-one. In one embodiment or in combination with any other embodiment, the film comprises less than 0.1 wt% of an unsubstituted or substituted (2-hydroxyphenyl)(phenyl)methanone or an unsubstituted or substituted 2H-chromen-2-one. In one embodiment or in combination with any other embodiment, the film comprises less than 0 wt% of an unsubstituted or substituted (2-hydroxyphenyl)(phenyl)methanone or an unsubstituted or substituted 2H-chromen-2-one.

In one embodiment or in combination with any other embodiment, the component A is present at greater than 1 wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 1wt% to 30wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 1wt% to 20wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 1wt% to 15wt%.

In one embodiment or in combination with any other embodiment, the component one class of this embodiment, the component A is present at greater than 1 wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 30wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 20wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 15wt%. In one embodiment or in combination with any other embodiment, the component A is In one class of this embodiment, the component A is present at greater than 1 wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 30wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 20wt%. In one clas of this embodiment, the component A is present in the range of from 1wt% to 15wt%.

In one embodiment or in combination with any other embodiment, the component A is 1 ,3-diphenyl-1 ,3-propanedione, avobenzone, 2-(4,6-diphenyl- 1 ,3,5-triazin-2-yl)-5-(hexyloxy)phenol, 2-[4,6-bis(2,4-dimethylphenyl)-1 ,3,5-triazin- 2-yl]-5-[2-hydroxy-3-(dodecyloxy- and tridecyloxy)propoxy]phenols, isooctyl 2-(4- (4,6-di([1 ,1'-biphenyl]-4-yl)-1 ,3,5-triazin-2-yl)-3-hydroxyphenoxy)propanoate, 6,6'- (6-(2,4-dibutoxyphenyl)-1 ,3,5-triazine-2,4-diyl)bis(3-butoxyphenol), 2-(4,6-bis(2,4- dimethylphenyl)-1 ,3,5-triazin-2-yl)-5-(3-((2-ethylhexyl)oxy)-2- hydroxypropoxy)phenol, 2-(4,6-di([1 ,1 '-biphenyl]-4-yl)-1 ,3,5-triazin-2-yl)-5-((2- ethylhexyl)oxy)phenol, or combinations thereof.

In one class of this embodiment, the component A is present at greater than 1 wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 30wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 20wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 15wt%.

In one embodiment or in combination with any other embodiment, the component A is 1 ,3-diphenyl- 1 ,3-propanedione. In one class of this embodiment, the component A is present at greater than 1 wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 30wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 1wt% to 20wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 15wt%. In one embodiment or in combination with any other embodiment, the component A is avobenzone. In one class of this embodiment, the component A is present at greater than 1 wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 30wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 20wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 15wt%.

In one embodiment or in combination with any other embodiment, the component A is, 2-(4,6-diphenyl-1 ,3,5-triazin-2-yl)-5-(hexyloxy)phenol (Tinuvin® 1577). In one class of this embodiment, the component A is present at greater than 1 wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 30wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 20wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 15wt%.

In one embodiment, the component A is isooctyl 2-(4-(4,6-di([1 ,1 biphenyl]-4-yl)-1 ,3,5-triazin-2-yl)-3-hydroxyphenoxy)propanoate (Tinuvin® 479). In one class of this embodiment, the component A is present at greater than 1 wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 30wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 20wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 15wt%.

In one embodiment, the component A is 2-(4,6-di([ 1 ,1 '-biphenyl]-4-yl)- 1 ,3,5-triazin-2-yl)-5-((2-ethylhexyl)oxy)phenol (Tinuvin® 1600). In one class of this embodiment, the component A is present at greater than 1 wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 30wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 20wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 15wt%.

In one embodiment or in combination with any other embodiment, the component A is 6,6'-(6-(2,4-dibutoxyphenyl)-1 ,3 ,5-triazine-2,4-diyl)bis(3- butoxyphenol) (Tinuvin® 460). In one class of this embodiment, the component A is present at greater than 1 wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 30%. In one class of this embodiment, the component A is present in the range of from 1wt% to 20wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 15wt%.

In one embodiment or in combination with any other embodiment, the component A is 2-(4,6-bis(2,4-dimethylphenyl)-1 ,3 ,5-triazin-2-yl)-5-(3-((2- ethylhexyl)oxy)-2-hydroxypropoxy)phenol. In one class of this embodiment, the component A is present at greater than 1 wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 30%. In one class of this embodiment, the component A is present in the range of from 1wt% to 20wt%. In one class of this embodiment, the component A is present in the range of from 1wt% to 15wt%.

In one embodiment or in combination with any other embodiment, the celluloses ester has a degree of substitution for the first unsaturated or saturated (Ci-e)alkyl-acyl substituent (“DSFAk”) that is from 0.7 to 2.2. In one embodiment, the celluloses ester has a degree of substitution for the first unsaturated or saturated (Ci-e)alkyl-acyl substituent (“DSFAk”) that is from 0.7 to 1 .9.

In one class of this embodiment, the first unsaturated or saturated (Ci- 2o)alkyl-CO- substituent is acetyl, propionyl, butyryl, isobutyryl, 3-methylbutanoyl, pentanoyl, 4-methylpentanoyl, 3-methylpentanoyl, 2-methylpentanoyl, hexanoyl, or crotonyl. In one class of this embodiment, the first unsaturated or saturated (Ci-e)alkyl-CO- substituent is acetyl, propionyl, or crotonyl.

In one embodiment or in combination with any other embodiment, the cellulose ester further comprises a plurality of a second unsaturated or saturated (Ci-2o)alkyl-CO- substituent that is different than the first (Ci-e)alkyl-CO-. In one class of this embodiment, the degree of substitution for the second unsaturated or saturated (Ci-2o)alkyl-CO- substituent (“DSsAk”) is from 0.05 to 0.6.

In one class of this embodiment, the second unsaturated or saturated (Ci- 2o)alkyl-CO- substituent is acetyl, propionyl, butyryl, isobutyryl, 3-methylbutanoyl, pentanoyl, 4-methylpentanoyl, 3-methylpentanoyl, 2-methylpentanoyl, hexanoyl, pivalyl, or 2-ethylhexanoyl. In one class of this embodiment, the second unsaturated or saturated (Ci-2o)alkyl-CO- substituent is acetyl, isobutyryl, 3- methylbutanoyl, pentanoyl, 4-methylpentanoyl, 3-methylpentanoyl, 2- methylpentanoyl, hexanoyl, or 2-ethylhexanoyl. In one class of this embodiment, the second unsaturated or saturated (Ci-2o)alkyl-CO- substituent is acetyl or 2- ethylhexanoyl.

In one embodiment or in combination with any other embodiment, the aromatic-CO- is an (Ce-2o)aryl-CO-, wherein the aryl is unsubstituted or substituted by 1 -5 R ¹ . In one class of this embodiment, the aromatic-CO- is benzoyl or naphthoyl, which is unsubstituted or substituted by 1 -5 R ¹ . In one class of this embodiment, the aromatic-CO- is benzoyl, unsubstituted or substituted by 1 -5 R ¹ . In one class of this embodiment, the aromatic-CO- is naphthoyl, unsubstituted or substituted by 1 -5 R ¹ .

In one embodiment or in combination with any other embodiment, the aromatic-CO- is benzoyl, unsubstituted or substituted by 1 -5 R ¹ . In one class of this embodiment, the cellulose ester has a total DSArco of from 0.40 to 1 .60. In one subclass of this class, the sum of C2DSArco and C3DSArco is from 0.30 to 1.25.

In one class of this embodiment, the cellulose ester has a total DSArco of from 0.50 to 1 .50. In one subclass of this class, the sum of C2DSArco and C3DS _A rco is from 0.30 to 1 .20.

In one embodiment or in combination with any other embodiment, the aromatic-CO- is naphthoyl, unsubstituted or substituted by 1 -5 R ¹ . In one class of this embodiment, the cellulose ester has a total DSArco of from 0.30 to 0.6. In one subclass of this class, the sum of C2DSArco and C3DSArco is from 0.20 to 0.40. In one subclass of this class, the sum of C2DSArco and C3DSArco is from 0.30 to 0.40.

In one class of this embodiment, the cellulose ester has a total DSArco of from 0.50 to 1 .10. In one subclass of this class, the sum of C2DSArco and C3DS _A rco is from 0.20 to 0.40. In one subclass of this class, the sum of C2DSArco and C3DS _A rco is from 0.30 to 0.40.

In one embodiment or in combination with any other embodiment, the aromatic-CO- is heteroaryl-CO-, wherein the heteroaryl is a 5- to 10-membered ring having 1 - to 4- heteroatoms chosen from N, O, or S, and wherein the heteroaryl is unsubstituted or substituted by 1 -5 R ¹ . In one class of this embodiment, the heteroaryl-CO- is a pyridinyl-CO-, a pyrimidinyl-CO-, a furanyl- CO-, or a pyrrolyl-CO-. In one class of this embodiment, the heteroaryl-CO- is 2- furoyl.

In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 0.4 to 1 .6. In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 1 .0 to 1 .6. In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 0.3 to 1 .25. In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 0.4 to 1 .2. In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 0.4 to 0.8. In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 0.3 to 0.8. In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 0.3 to 0.6. In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 0.2 to 06. In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 0.2 to 0.5. In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 0.8 to 1 .2. In one embodiment or in combination with any other embodiment, the cellulose ester has a totDSArco of from 0.5 to 1.1.

In one embodiment or in combination with any other embodiment, the DSOH is from 0.3-1 .0. In one embodiment or in combination with any other embodiment, the DSOH is from 0.3-0.9. In one embodiment or in combination with any other embodiment, the DSOH is from 0.4-0.9. In one embodiment or in combination with any other embodiment, the DSOH is from 0.5-0.9. In one embodiment or in combination with any other embodiment, the DSOH is from 0.6- 0.9. In one embodiment or in combination with any other embodiment, the DSOH is from 0.4-0.8. In one embodiment or in combination with any other embodiment, the DSOH is from 0.5-0.8.

In one embodiment or in combination with any other embodiment, the sum of the C2DS _A rco and C3DSArco is from 0.3 to 1 .25. In one embodiment or in combination with any other embodiment, the sum of the C2DSArco and C3DSArco is from 0.2 to 0.4. In one embodiment or in combination with any other embodiment, the sum of the C2DSArco and C3DSArco is from 0.3 to 0.4. In one embodiment or in combination with any other embodiment, the sum of the C2DS _A rco and C3DSArco is from 0.4 to 1 .2. In one embodiment or in combination with any other embodiment, the sum of the C2DSArco and C3DSArco is from 0.4 to 1.1. In one embodiment or in combination with any other embodiment, the sum of the C2DSArco and C3DSArco is from 0.4 to 1 .0. In one embodiment or in combination with any other embodiment, the sum of the C2DSArco and C3DSArco is from 0.5 to 1.1. In one embodiment or in combination with any other embodiment, the sum of the C2DSArco and C3DSArco is from 0.6 to 1 .0. In one embodiment or in combination with any other embodiment, the sum of the C2DS _A rco and C3DSArco is from 0.6 to 1 .25. In one embodiment or in combination with any other embodiment, the sum of the C2DSArco and C3DSArco is from 0.30 to 0.75.

In one embodiment or in combination with any other embodiment, the component A is present at greater than 1 wt%. In one embodiment or in combination with any other embodiment, the component A is present at greater than 2.5 wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 1wt% to 30wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 2.5wt% to 30wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 5wt% to 30wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 2.5wt% to 25wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 1wt% to 30wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 1wt% to 20wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 1wt% to 18wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 1wt% to 15wt%. In one embodiment or in combination with any other embodiment, the component A is present in the range of from 1wt% to 10wt%.

In one embodiment or in combination with any other embodiment, m is 1 . In one embodiment or in combination with any other embodiment, m is 2. In one embodiment or in combination with any other embodiment, m is 3. In one embodiment or in combination with any other embodiment, m is 4. In one embodiment or in combination with any other embodiment, m is 5. In one embodiment or in combination with any other embodiment, m is 1 , 2, 3, or 4. In one embodiment or in combination with any other embodiment, m is 1 , 2, or 3. In one embodiment or in combination with any other embodiment, m is 1 , or 2.

In one embodiment or in combination with any other embodiment, n is 1 . In one embodiment or in combination with any other embodiment, n is 2. In one embodiment, n is 3. In one embodiment or in combination with any other embodiment, n is 4. In one embodiment, n is 5. In one embodiment or in combination with any other embodiment, n is 1 , 2, 3, or 4. In one embodiment or in combination with any other embodiment, n is 1 , 2, or 3. In one embodiment or in combination with any other embodiment, n is 1 , or 2.

A plasticizer can be added to improve workability and flexibility of the films. It may lower the glass transition point and melting temperature of the material the film is formed from, which could facilitate lower temperature and/or simplified film manufacturing. The plasticizer should be compatible with cellulose esters disclosed herein and have a boiling point higher than the maximum temperature applied in the film preparation and conditioning process requiring in particular nonvolatile plasticizer compounds in the case of film formation by melt casting.

In one embodiment or in combination with any other embodiment, the film further comprises 0.1 to 15 wt% of a plasticizer.

In one class of this embodiment or in combination with any other class of this embodiment, the plasticizer is present from 0.1 to 10 wt%. In one class of this embodiment or in combination with any other class of this embodiment, the plasticizer is present from 0.1 to 5 wt%. In one class of this embodiment or in combination with any other class of this embodiment, the plasticizer is present from 5 to 10 wt%. In one class of this embodiment or in combination with any other class of this embodiment, the plasticizer is present from 3 to 7 wt%.

In one class of this embodiment or in combination with any other class of this embodiment, the plasticizer is chosen from a phosphate type plasticizer, a phthalate type plasticizer, a terephthalate type plasticizer, a trimelitate type plasticizer, a benzoate type plasticizer, a glycolate type plasticizer, a citrate type plasticizer, a polyvalent alcohol ester type plasticizer, a polyol type plasticizer, a sugar ester type plasticizer, a cellulose ester type plasticizer, or a polyester type plasticizer. In one subclass of this class, the plasticizer is chosen from

Nonlimiting examples of glycolate plasticizers include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phihalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl ethyl glycolate, ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, propyl phthalyl butyl glycolate, butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octyl phthalyl methyl glycolate and octyl phthalyl ethyl glycolate.

Nonlimiting examples of phosphate type plasticizers include triphenyl phosphate and tricresyl phosphate.

Nonlimiting examples of citrate type plasticizers include triacetyl citrate and tributyl citrate.

Nonlimiting examples of benzoate type plasticizers include 2-naphthyl benzoate (BANE), dipropylene glycol dibenzoate, 1 ,4-cyclohexane dimethanol diben-zoate, 2,2,4-trimethyl-1 ,3-pentanediol, dibenzoate, and diethylene glycol dibenzoate.

Nonlimiting examples of phthalate type plasticizers include dicyclohexyl phthalate, dibenzyl phthalate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, diphenyl phthalate, and dihexyl phthalate.

Nonlimiting examples of phthalate type plasticizers include dimethyl terephthalate, diethyl terephthalate, dibutyl terephthalate, di-2-ethylhexyl terephthalate, diphenyl terephthalate and dihexyl terephthalate.

Nonlimiting examples of polyester type plasticizers include adipic acid polyesters such as Admex 523, Admex 6995, and Admex 760.

Nonlimiting examples of polyol type plasticizers include cyclohexane-1 ,4- dimethanol, sorbitol, 1 ,3-propanediol, ethylene glycol, glycerine, triethyleneglycol, tetramethyleneglycol, trimethylolpropane, and xylitol.

Nonlimiting examples of polyvalent alcohol ester type plasticizers include triethylene glycol bis (2-ethylhexanoate), dipropylene glycol dibenzoate, and diethylene glycol dibenzoate. Nonlimiting examples of trimellitate type plasticizers include tris(2-ethylhexanoate) trimellitate, and cresyldiphenyl phosphate.

Nonlimiting examples of cellulose ester type plasticizers include cellulose acetate, cellulose propionate, cellulose butyrate, cellulate acetate propionate, cellulose acetate butyrate

In one embodiment or in combination with any other embodiment, the plasticizer is triphenyl phosphate, diethyl phthalate, 2,2,4-trimethyl-1 ,3- pentanediol dibenzoate, 1 ,4-cyclohexane dibenzoate, 2-naphthyl benzoate, triethylene glycol bis (2-ethylhexanoate), polyesters having a weight average molecular weight of less than 10,000 g/mol, cellulose ester having a weight average molecular weight of less than 10,000 g/mol, or a combination thereof.

In one embodiment or in combination with any other embodiment, the plasticizer is a plasticizer having one or more aromatic groups.

The films disclosed in this application are useful in LCD, OLED, and QD OLED devices. The present application discloses a device comprising any of the previously disclosed films.

In one embodiment, the device is a liquid crystal display (LCD), organic light emitting diode (OLED), or quantum dot organic light emitting diode (QD OLED) device. In one class of this embodiment, the device is an LCD device. In one class of this embodiment, the device is an OLED device. In one class of this embodiment, the device is an QD OLED device.

The present application also discloses a composition comprising: (1 ) a regioselectively substituted cellulose ester comprising: (i) a plurality of aromatic- CO- substituents; (ii) a plurality of a first unsaturated or saturated (Ci-6)alkyl-CO- substituents; and (iii) a plurality of hydroxyl substituents; wherein: the degree of substitution for the hydroxyl (“DSOH”) is from 0.2 to 1 .1 , the cellulose ester has a C2 degree of substitution for the aromatic-CO- substituent (“C2DSArco”) which is from 0.15 to 0.8, the cellulose ester has a C3 degree of substitution for the aromatic-CO- substituent (“C3DSArco”) which is from 0.05 to 0.6, the cellulose ester has a C6 degree of substitution for the aromatic-CO- substituent (“C6DSArco”) which is from 0.05 to 0.6, the total degree of substitution for the aromatic-CO- substituent (“TotDSArco”) which is from 0.25 to 2.0, the aromatic- CO- is (i) an (C6-2o)aryl-CO-, wherein the aryl is unsubstituted or substituted by 1 - 5 R ¹ ; or (ii) a heteroaryl-CO-, wherein the heteroaryl is a 5- to 10-membered ring having 1 - to 4- heteroatoms chosen from N, O, or S, and wherein the heteroaryl is unsubstituted or substituted by 1 -5 R ¹ ; and (2) a component A that is wherein: ring A is an (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; ring B is (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; ring C is (Ce- 2o)aryl or a 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; each R ¹ is independently saturated or unsaturated (Ci-2o)alkyl; saturated or unsaturated halo(Ci-2o)alkyl; saturated or unsaturated (Ci-2o)alkoxy; saturated or unsaturated halo(Ci-2o)alkoxy; (Ce-2o)aryl unsubstituted or substituted by 1 -5 alkyl, haloalkyl, alkoxy, haloalkoxy, halo; 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; or -CH2C(O)-R ³ ; R ² is independently hydrogen, saturated or unsaturated (Ci-2o)alkyl, or saturated or unsaturated halo(Ci-2o)alkyl; each R ³ is independently saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, (Ce-2o)aryl, or 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S, wherein the aryl or heteroaryl are unsubstituted or substituted by 1 -5 R ⁶ ; each R ⁴ is independently saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated hetero(Ci-2o)alkyl containing 1 -2 heteroatoms chosen from N, O or S, saturated or unsaturated (Ci-2o)alkyl-CO-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated halo(Ci- 2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-0- CO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci- 2o)alkyl-0-CO-(Ci-2o)alkyl, (Ce-2o)aryl unsubstituted or substituted with 1 -5 R ⁶ , or 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S unsubstituted or substituted with 1 -5 R ⁶ , wherein each of the groups is unsubstituted or substituted by 1 -3 hydroxyl, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl-, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C(i-2o)alkyl, saturated or unsaturated (Ci- 2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO- (Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, unsubstituted or substituted (Ce-2o)aryl, or unsubstituted or substituted 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; each R ⁶ is independently hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated halo(Ci-2o)alkoxy, halo, (Ce-2o)aryl, 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S, saturated or unsaturated hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C<i- 2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, or (Ci-2o)alkoxy-(Ci- 2o)alkyl-0-CO-(Ci-2o)alkyl, wherein each of the groups is unsubstituted or substituted by 1 -5 R ⁷ ; each R ⁷ is independently hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated hydroxy(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-hydroxy(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl- CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci- 2o)alkoxy, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or nsaturated (Ci- 2o)alkyl-COO, saturated or unsaturated (C1 -20)alkyl-O-CO, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl- COO, saturated or unsaturated (Ci-2o)alkoxy-(C1 -20)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl- 0-CO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- (Ci-2o)alkyl-COO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl- 0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci- 2o)alkoxy; each R ⁹ is independently R ⁴ -O-, hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated hetero(Ci-2o)alkyl containing 1 - 2 heteroatoms chosen from N, O or S, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-0-CO-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci- 2o)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-0-(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- (Ci-2o)alkyl-COO-(Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, (Ce- w)aryl unsubstituted or substituted with 1 -5 R ⁶ , 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S unsubstituted or substituted with 1 -5 R ⁶ , wherein each of the groups are unsubstituted or substituted by 1 -3 hydroxy, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy, or saturated or unsaturated halo(Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci- 2o)alkyl-, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci- 2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- (Ci-2o)alkyl-COO-(Ci-2o)alkyl, or (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, unsubstituted or substituted (Ce-2o)aryl, or unsubstituted or substituted 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; each n is independently 0, 1 , 2, 3, 4, or 5; each m is independently 0, 1 , 2, 3, 4, or 5; and k is independently 0, 1 , 2, 3, or 4, wherein: component A is present at less than 30 wt %, based on the total weight of the compostion.

Specific Embodiments

Embodiment 1 . A film comprising: (1 ) a regioselectively substituted cellulose ester comprising: (i) a plurality of aromatic-CO- substituents; (ii) a plurality of a first unsaturated or saturated (Ci-e)alkyl-CO- substituents; and (iii) a plurality of hydroxyl substituents; wherein: the degree of substitution for the hydroxyl (“DSOH”) is from 0.2 to 1 .1 , the cellulose ester has a C2 degree of substitution for the aromatic-CO- substituent (“C2DSArco”) which is from 0.15 to 0.8, the cellulose ester has a C3 degree of substitution for the aromatic-CO- substituent (“C3DSArco”) which is from 0.05 to 0.6, the cellulose ester has a C6 degree of substitution for the aromatic-CO- substituent (“C6DSArco”) which is from 0.05 to 0.6, the total degree of substitution for the aromatic-CO- substituent (“TotDSArco”) which is from 0.25 to 2.0, the aromatic-CO- is (i) an (Ce-2o)aryl-CO-, wherein the aryl is unsubstituted or substituted by 1 -5 R ¹ ; or (ii) a heteroaryl-CO-, wherein the heteroaryl is a 5- to 10-membered ring having 1 - to 4- heteroatoms chosen from N, O, or S, and wherein the heteroaryl is unsubstituted or substituted by 1 -5 R ¹ ; and (2) a component A that is

, wherein: ring A is an (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; ring B is (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; ring C is (Ce-2o)aryl or a 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; each R ¹ is independently saturated or unsaturated (Ci-2o)alkyl; saturated or unsaturated halo(Ci-2o)alkyl; saturated or unsaturated (Ci-2o)alkoxy; saturated or unsaturated halo(Ci-2o)alkoxy; (Ce-2o)aryl unsubstituted or substituted by 1 -5 alkyl, haloalkyl, alkoxy, haloalkoxy, halo; 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; or -CH2C(O)-R ³ ; R ² is independently hydrogen, saturated or unsaturated (Ci-2o)alkyl, or saturated or unsaturated halo(Ci-2o)alkyl; each R ³ is independently saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, (Ce-2o)aryl, or 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S, wherein the aryl or heteroaryl are unsubstituted or substituted by 1 -5 R ⁶ ; each R ⁴ is independently saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated hetero(Ci-2o)alkyl containing 1 -2 heteroatoms chosen from N, O or S, saturated or unsaturated (Ci-2o)alkyl-CO-(Ci-2o)alkyl, , saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated halo(Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C<i- 2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl- 0-CO-(Ci-2o)alkyl, (Ce-2o)aryl unsubstituted or substituted with 1 -5 R ⁶ , or 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S unsubstituted or substituted with 1 -5 R ⁶ , wherein each of the groups is unsubstituted or substituted by 1 -3 hydroxyl, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl-, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C(i-2o)alkyl, saturated or unsaturated (Ci- 2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO- (Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, unsubstituted or substituted (Ce-2o)aryl, or unsubstituted or substituted 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S; each R ⁶ is independently hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated halo(Ci-2o)alkoxy, halo, (Ce-2o)aryl, 5- to 10-membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S, saturated or unsaturated hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C<i- 2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, or (Ci-2o)alkoxy-(Ci- 2o)alkyl-0-CO-(Ci-2o)alkyl, wherein each of the groups is unsubstituted or substituted by 1 -5 R ⁷ ; each R ⁷ is independently hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy, saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated hydroxy(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-hydroxy(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl- CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci- 2o)alkoxy, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci- 2o)alkyl-COO, saturated or unsaturated (C1 -20)alkyl-O-CO, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkyl- COO, saturated or unsaturated (Ci-2o)alkoxy-(C1 -20)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl- 0-CO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- (Ci-2o)alkyl-COO-(Ci-2o)alkoxy, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl- 0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci- 2o)alkoxy; each R ⁹ is independently R ⁴ -O-, hydroxy, cyano, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated hetero(Ci-2o)alkyl containing 1 - 2 heteroatoms chosen from N, O or S, saturated or unsaturated halo(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-0-CO-(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO, saturated or unsaturated (Ci- 2o)alkyl-0-CO, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-0-(Ci-2o)alkyl, saturated or unsaturated (Ci- 2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- (Ci-2o)alkyl-COO-(Ci-2o)alkyl, (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl, (Ce- w)aryl unsubstituted or substituted with 1 -5 R ⁶ , 5- to 10- membered heteroaryl containing 1 -4 heteroatoms chosen from N, O, or S unsubstituted or substituted with 1 -5 R ⁶ , wherein each of the groups are unsubstituted or substituted by 1 -3 hydroxy, saturated or unsaturated (Ci-2o)alkyl, saturated or unsaturated halo(Ci- 2o)alkyl, saturated or unsaturated (Ci-2o)alkoxyl, or saturated or unsaturated halo(Ci-2o)alkoxyl. saturated or unsaturated hydroxy(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- hydroxy(Ci-2o)alkyl, or saturated or unsaturated (Ci-2o)alkoxy-(Ci-2o)alkyl-CO-(Ci- 2o)alkyl-, saturated or unsaturated (Ci-2o)alkyl-CO, saturated or unsaturated (Ci- 2o)alkyl-COO, saturated or unsaturated (Ci-2o)alkyl-0-CO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkyl-COO-C(i-2o)alkyl, saturated or unsaturated (Ci-2o)alkoxy- (Ci-2o)alkyl-COO-(Ci-2o)alkyl, or (Ci-2o)alkoxy-(Ci-2o)alkyl-0-CO-(Ci-2o)alkyl unsubstituted or substituted (Ce-2o)aryl, or unsubstituted or substituted 5- to 10- membered heteroaryl containing 1-4 heteroatoms chosen from N, O, or S; each n is independently 0, 1 , 2, 3, 4, or 5; each m is independently 0, 1 , 2, 3, 4, or 5; and k is independently 0, 1 , 2, 3, or 4, wherein: component A is present at less than 30 wt %, based on the total weight of the film, the film exhibits a R _e (589 nm) that is from -100 nm to -350 nm, the film exhibits a Rth(589 nm) that is from -100 nm to 100 nm, the film exhibits a ratio of R _e (450 nm)/R _e (550 nm) that is 0.7 to 1.20, the film exhibits a ratio of R _e (650 nm)/R _e (550 nm) that is 0.9 to 1 .25, the film exhibits a [[-Rth(589 nm)/R _e (589 nm)] + 0.5] (“Nz“) that is from 0.2 to 0.8, each Rth(589 nm) is the out-of-plane retardation measured at 589 nm, each R _e (589 nm), R _e (450 nm), R _e (550 nm) is the in-plane retardation measured at 589 nm, 450 nm, and 550 nm, respectively, and the film is stretched.

Embodiment 2. The film of Embodiment 1 , wherein the film is stretched at a temperature of from 100°C to 220°C.

Embodiment 3. The film of any one of Embodiments 1 -2, wherein the film is stretched at a temperature between T _g - 30°C and T _g + 50°C, wherein Tg is the glass transition temperature of the film.

Embodiment 4. The film of any one of Embodiments 1 -3, wherein R _e (589 nm) is from -120 to -320 nm and Rth (589 nm) is from -60 to 60 nm.

Embodiment 5. The film of any one of Embodiments 1 -4, wherein the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 1 .05, wherein R _e (450 nm) is the in-plane retardation measured at 450 nm, and R _e (550 nm) is the in-plane retardation measured at 550 nm.

Embodiment 6. The film of Embodiment 5, wherein the ratio of R _e (450 nm)/R _e (550 nm) is from 0.75 to 0.85.

Embodiment 7. The film of any one of Embodiment 1 -6, wherein the component

Embodiment 8. The film of any one of Embodiment 1 -7, wherein the component A is 1 ,3-diphenyl-1 ,3-propanedione, avobenzone, 2-(4,6-diphenyl-1 ,3,5-triazin-2- yl)-5-(hexyloxy)phenol, 2-[4,6-bis(2,4-dimethylphenyl)-1 ,3,5-triazin-2-yl]-5-[2- hydroxy-3-(dodecyloxy- and tridecyloxy)propoxy]phenols, isooctyl 2-(4-(4,6- di([1 , 1 ’-biphenyl]-4-yl)-1 ,3,5-triazin-2-yl)-3-hydroxyphenoxy)propanoate, 6,6’-(6- (2,4-dibutoxyphenyl)-1 ,3,5-triazine-2,4-diyl)bis(3-butoxyphenol), 2-(4,6-bis(2,4- dimethylphenyl)-1 ,3,5-triazin-2-yl)-5-(3-((2-ethylhexyl)oxy)-2- hydroxypropoxy)phenol, 2-(4,6-di([ 1 ,1 ’-biphenyl]-4-yl)-1 ,3 ,5-triazin-2-yl)-5-((2- ethylhexyl)oxy)phenol or combinations thereof.

Embodiment 9. The film of any one of Embodiments 1 -8, wherein the aromatic- CO- is an (Ce-2o)aryl-CO-, wherein the aryl is unsubstituted or substituted by 1 -5 R ¹ .

Embodiment 10. The film of Embodiment 9, wherein the aromatic-CO- is benzoyl or naphthoyl, which is unsubstituted or substituted by 1 -5 R ¹ .

Embodiment 11 . The film of Embodiment 10, wherein the aromatic-CO- is benzoyl, unsubstituted or substituted by 1 -5 R ¹ .

Embodiment 12. The film of Embodiment 11 , wherein the cellulose ester has a totDSArco of from 0.50 to 1 .60.

Embodiment 13. The film of Embodiment 12, wherein the sum of C2DSArco and C3DSArco is from 0.30 to 1 .25.

Embodiment 14. The film of Embodiment 13, wherein the aromatic-CO- is naphthoyl, unsubstituted or substituted by 1 -5 R ¹ . Embodiment 15. The film of Embodiment 14, wherein cellulose ester has a totDSArco of from 0.3 to 0.8.

Embodiment 16. The film of Embodiment 15, wherein the sum of C2DSArco and C3DSArco is from 0.2 to 0.6.

Embodiment 17. The film of any one of Embodiments 1 -16, wherein the cellulose ester further comprises a plurality of a second (Ci-2o)alkyl-CO- substituent. Embodiment 18. The film of any one of Embodiments 1 -17, wherein the film further comprises one or more plasticizers.

Embodiment 19. The film of Embodiment 18, wherein the plasticizer is phosphate ester plasticizer, a phthalate ester plasticizer, mono- or dibenzoate plasticizer, sugar ester plasticizer, glycol ester plasticizer, polyester plasticizer, cellulose ester plasticizer, or a combination thereof.

Embodiment 20. The film of any one of Embodiments 18-19, wherein the plasticizer is triphenyl phosphate, diethyl phthalate, 2,2,4-trimethyl-1 ,3- pentanediol dibenzoate, 1 ,4-cyclohexane dibenzoate, 2-naphthyl benzoate, triethylene glycol bis (2-ethylhexanoate), polyesters having a weight average molecular weight of less than 10,000 g/mol, cellulose ester having a weight average molecular weight of less than 10,000 g/mol, or a combination thereof. Embodiment 21 . The film of any one of Embodiments 18-20, wherein the plasticizer is a plasticizer having one or more aromatic groups.

Embodiment 21 . The film of any one of Embodiments 1 -20, wherein the film is stretched along the machine direction (“MD”), shrunk along the MD, stretched along transverse direction (“TD”), shrunk along the TD, or a combination thereof. Embodiment 22. The film of any one of Embodiments 1 -21 , wherein the slow axis in the film plane forms an angle between 0° to 180° relative to the MD of the film.

EXAMPLES

Abbreviations

1 MIM: 1 -methylimidazole; 2EH or 2-EH: 2-ethylhexanoyl; 2EHCI: 2- ethylhexanoyl chloride; AcOH: acetic acid; Ak: alkyl acyl or alkyl-CO-; Ak1 is same as Fak; Ak2 is same as Sak; Ar: aryl; ArCO: aryl-acyl or aryl-CO-; atm: atmosphere; Bz: benzoyl; BzCI: benzoyl chloride; BZ2O: Benzoic anhydride; °C: degree(s) Celsius; C2DS: degree substitution at the C2 position; C3DS: the degree of substitution at the C3 position; C6DS: the degree of substitution at the C6 position; CacPr: acetyl propionyl substituted cellulose ester or cellulose acetate propionate; CCrBz: crotonyl and benzoyl substituted cellulose ester or cellulose crotonate benzoate; CE: cellulose ester(s); Coc: octanoyl substituted cellulose ester or cellulose octanoate; CPN: cyclopentanone; CPr: propionyl substituted cellulose ester or cellulose propionate; CPrBz: propionyl and benzoyl substituted cellulose ester or cellulose propionate benzoate; CPr2EH: propionyl and 2-ethylhexanoyl substituted cellulose ester or cellulose propionate 2- ethylhexanoate; CPr2EHBz: propionyl, 2-ethylhexanoyl and benzoyl substituted cellulose ester or cellulose propionate 2-ethylhexanoate benzoate; CPr2EHF: propionyl, 2-ethylhexanoyl and furanoyl substituted cellulose ester or cellulose propionate 2-ethylhexanoate furoate; CPr2EHNp: propionyl, 2-ethylhexanoyl and naphthoyl substituted cellulose ester or cellulose 2-ethylhexanoate naphthoate; CPrNp: propionyl and naphthoyl substituted cellulose ester or cellulose propionate naphthoate; CprAcBz: propionyl acetyl and benzoyl substituted cellulose ester or cellulose propionate acetate benzoate; CCrBz: crotonyl benzoyl substituted cellulose ester or cellulose crotonate benzoate; CPrPvNp: propionyl, Pivaloyl and naphthoyl substituted cellulose ester or cellulose propionate pivalate naphthoate; DCM: dichloromethane; DEAMC: 7-diethylamino-4-methylcoumarin; DEP: diethyl phthalate; DHODPO: (2-hydroxy-4-methoxyphenyl)(2- hydroxyphenyl)methanone; BANE: 2-naphthyl benzoate; DMAC: dimethyl acetamide; DMSO: Dimethyl sulfoxide; DPDO: 1 ,3-diphenylpropane-1 ,3-dione; DS: average degree substitution; eq: equivalent(s); EtOH: ethanol; Ex: example(s); F: furan-2-CO-; Fak: first alkyl-acyl, Ak1 or first alkyl-CO-; Far: first aryl-acyl or first aryl-CO-; FCI: furan-2-carbonyl chloride; g: gram; HODPO: (2- hydroxy-4-(octyloxy)phenyl)(phenyl)methanone; /-PrOH: iso-propanol; KOAc: potassium acetate; MEK: methyl ethyl ketone; hr or h: hour(s); L: liter; MeOH: methanol; min: minute(s); mL: milliliter; pm: micrometer or micron; mol: mole(s); mol eq: mole equivalent based on moles of anhydroglucose unit; NMP: N- Methylpyrrolidone; Np: naphthoyl; NpCI: naphthoyl chloride; Pr: propionyl; Pr20: propionic anhydride; PrCI: propionyl chloride; RBF: round bottom flask; RM: reaction mixture; SM: starting material; Int: intermediate; rt: room temperature; Sak: second alkyl-acyl or second alkyl-CO-; Sar: second aryl-acyl or second aryl- CO-; TBMADMP: tributylmethylammonium dimethylphosphate; Tot.: total; TFA: trifluoroacetic acid; TFAA: trifluoroacetic anhydride; UV: ultraviolet.

NMR Characterization: Proton NMR data were obtained on a JEOL Model Eclipse-600 NMR spectrometer operating at 600 MHz. The sample tube size was 5 mm, and the sample concentrations were ca. 20 mg/mL DMSO-de. Each spectrum was recorded at 80°C. using 64 scans and a 15 second pulse delay. One to two drops of trifluoroacetic acid-d were added to each sample to shift residual water from the spectral region of interest. Chemical shifts are reported in parts per million (“ppm”) from tetramethylsilane with the center peak of DMSO-d6 as an internal reference (2.49 ppm).

Quantitative ¹³ C NMR data were obtained on a JEOL Model GX-400 NMR spectrometer operating at 100 MHz. The sample tube size was 10 mm, and the sample concentrations were ca. 100 mg/mL DMSO-de. Chromium(lll) acetylaceto nate was added to each sample at 5 mg/100 mg cellulose ester as a relaxation agent. Each spectrum was typically recorded at 80°C. using 10000 scans and a 1 second pulse delay. Chemical shifts are reported in ppm from tetramethylsilane with the center peak of DMSO-d6 as an internal reference (39.5 PPm).

The proton and carbon NMR assignments, the degree of substitution and the relative degree of substitution (“RDS”) of the various acyl groups of the cellulose esters were determined by adapting the procedures disclosed in US 2012/0262650.

DMTA measurements were run DMA Q800 from TA Instruments with isothermal temperature set for 5 min followed by temperature ramp from 25°C to 230°C at 3°C/min. The oscillation strain was set at 0.1 %. Onset point of storage modulus can be used to determine the glass transition temperature (Tg) of the samples.

Differential scanning calorimetry (DSC) measurements were run with DSC Q2000 from 0 °C to 200°C or from 0 °C to 240°C in first heat, cooled back to 0 °C and reheat from 0 °C to 200 °C or 0 °C to 240°C at rate of 20 °C/min. 2 ^nd heat curve was used to determine the glass transition temperature (Tg) of the samples.

The solutions of the cellulose esters for preparation of the films and the film preparation were made by adapting the procedures disclosed in US 2012/0262650.

Solution preparation for film casting: cellulose ester solids and additives were added to solvent to give a final solution concentration of 8 - 16 wt%. Higher or lower solution concentration can used if needed. The mixture was sealed, placed on a roller, and mixed for 24 hours to create a uniform solution

Percentages of component A or plasticizers in the films are defined as below. Percentage of component A or plasticizers = weight of component A or plasticizers/ total weight of cellulose esters, component A, plasticizers and all other non-solvent components added.

Solution concentration is defined as below. Solution concentration = total weight of (cellulose esters, component A, plasticizers and all other components added excluding solvents)/total weight of (cellulose esters, component A, plasticizers, all other components added and solvents).

Solvent used for solution preparation can be but are not limited to cyclopentanone (CPN), DCM, mixtures of DCM with acetone, ethanol or methanol such as aceto ne/D CM = 10/90 (wt/wt), methanol/DCM = 10/90 (wt/wt), methanol/DCM=5/95 and ethanol/DCM = 10/90 (wt/wt), ethanol/DCM = 5/95 (wt/wt).

Film casting: The solution prepared above was cast onto a glass plate using a doctor blade to obtain a film with the desired thickness. Casting was conducted in a fume hood with relative humidity controlled at 45%~50%. After casting, if acetone/DCM = 10/90 (wt/wt), methanol/DCM/methanol = 10/90 (wt/wt) and ethanol/DCM = 10/90 (wt/wt), methanol/DCM = 5/95 (wt/wt), and ethanol/DCM = 5/95 (wt/wt) were used as solvent, unless otherwise noted, the film was allowed to dry for 60 to 110 min under a cover pan to minimize rate of solvent evaporation before the pan was removed. The film was allowed to dry for 15 to 30 min then the film was peeled from the glass and annealed in a forced air oven for 10 min at 100 ^e C. After annealing at 100 ^e C, the film was annealed at a higher temperature (120 ^e C) for another 10 min. If CPN was used as solvent, unless otherwise noted, the film was dried under cover pan for 75 min before the pan was removed. The film was further dried for another 2 hour in the hood before the film was peeled from the glass and annealed in a forced air oven for 10 min at 100 ^e C. After annealing at 100 ^e C, the film was annealed at a higher temperature (130 ^e C) for another 10 min.

Film stretching: Film stretching was done by Bruckner Karo IV laboratory film stretcher. Stretching conditions, such as, stretch ratio, stretch temperature, pre-heating and post-annealing were varied to obtain specific optical retardation and dispersion according to the requirements of the application.

Stretch ratio is defined as the end dimension of the films after stretching relative to the dimension of the films before stretching along one direction as shown in equation 1 . For example, for films stretched uniaxially along MD from 100 mm to 140 mm, the stretch ratio is defined as1 .4. Stretch ratio smaller than 1 .0 means the films shrink along the direction. dimension after stretching stretch ratio = — - - — - - - - dimension before stretching

Optical measurements: Film optical retardation and dispersion measurements were made using a J.A. Woollam M-2000V Spectroscopic Ellipsometer having a spectral range from 370 to 1000 nm or J.A.Woollam RC2 Ellipsometer having a spectral range from 250 - 2500 nm. RetMeas (Retardation Measurement) program from J.A. Woollam Co., Inc. was used to obtain optical film in-plane (R _e ) and out-of-plane (Rth) retardations. The thickness of the films was measured using a Metricon Prism Coupler 2010 (Metricon Corp.) or using a handheld Positector 6000. The haze and b* measurements were made using a HunterLab Ultrascan VIS colorimeter in diffused transmittance mode (1 -inch diameter port).

Chemicals: DEP, Admex™ 523, Admex™ 525, Admex™ 760 and Admex™ 6995, Solus™ 2100, Solus™ 2300, Benzoflex™ 352, Benzoflex™ 354 were obtained from Eastman Chemical Company, 1 ,3-diphenylpropane-1 ,3- dione, (2-hydroxy-4-(octyloxy)phenyl)(phenyl)methanone, (2-hydroxy-4- methoxyphenyl)(2-hydroxyphenyl)methanone and 7-diethylamino-4- methylcoumarin were purchased from Millipore Sigma, (2-hydroxy-4- (octyloxy)phenyl)(phenyl)methanone was purchased from Alfa-Aesar, Avobenzone was purchased from Tokyo Chemical Industry Co., Ltd., Tinuvin® 400, Tinuvin® 405 and Tinuvin® 1577 were purchased from Ciba Specialty Chemical Corp, Tinuvin® 460, Tinuvin® 1600 and Tinuvin® 479 were purchased from BASF.

Example 1

To a 5-neck RBF was added TBMADMP (4405.2 g). The TBMADMP was heated to 100°C (5 h) at 1 .20 -1 .80 mm Hg. After removing the vacuum, NMP (1887.9 g, 30 wt%) was added to the RM, and the RM was cooled to rt. DPv 610 cellulose (473.3 g, 7 wt%) was added over a 20 min to the RM. The resulting RM was stirred for 55 min at rt. The mixture was stirred (6 h) at 100°C, stirred (3 h) at 30°C, and reheated to 102°C. To the RM was added Pr20 (456 g, 1 .2 eq) over 67 min. After 46 min, BZ2O (21 15 g (3.30 eq) was added to the RM over 20 min. The RM was stirred for 67 min, and chilled 30% H2O2 (45 mL) was added dropwise to the RM. Then the mixture was stirred for 30 min. The crude product was precipitated in a MeOH/F (95/5) solution, and the material was filtered, washed (5X) with MeOH, and dried in vacuo (55 mmHg, 50°C) to give the titled product. Analysis by ¹ H NMR: DSp _r = 1 .64 and a DSBZ = 0.69. Analysis by ¹³ C NMR: C6DS=0.94, C3DS=0.56, C2DS=0.83. By integration of the benzoate carbonyl resonances ¹³ C NMR also showed that C2DSBZ + C3DSBz - C6DSBz = 0.39.

Example 2

Ex 2 was prepared by adapting the procedure for the preparation of Ex 1 , using 3.35 eq, instead of 3.3 eq, of BZ2O instead.

Table 1

Intermediate 1 (CPr, DS _pr = 1 .13)

To a 4-neck RBF, under a N2 atm with overhead stirring and a bottom valve, was added iPrOH (259 g). The jacket was set at 41 °C. To the reactor was added Eastman™ CAP 482-20 (60 g, 1 mol eq), and the RM was stirred for 40 min. To the RM was added N2H4 H2O (18.0 g, 1 .89 mol eq) in AcOH (4.63 g, 0.41 mol eq) and DMSO (259 g). The RM was stirred for 24 hr. The crude product was precipitated by the addition of water. The crude product was filtered with a wash bag and washed with copious amounts of water. The solid was transferred to an aluminum pan and dried in vacuo (60°C) overnight to give the title compound. ¹ H NMR, ¹³ C NMR: DS _pr =1 .13, DSOH = 1 .87, C2DS = 0.26, C3DS = 0.34, C6DS = 0.53.

Intermediate 2 (CPr, DSp _r = 1.16)

Int 2 was prepared by adapting the procedure for the preparation of Int 1 , except that except that N2H4.H2O (1 .87 mol eq) and AcOH (0.4 mol eq) were added to Eastman™ CAP482-20 (1.0 mol eq). ¹ H NMR, ¹³ C NMR: DS _pr =1.16, DSOH=1 .84, C2DS=0.26, C3DS=0.32, DSce= 0.57.

Intermediate 3 (CPr, DSp _r = 1.18)

Int 3 was prepared by adapting the procedure for the preparation of Int 1 , except that N2H4.H2O (1 .85 mol eq) and AcOH (0.4 mol eq) were added to Eastman™ CAP482-20 (1.0 mol eq). ¹ H NMR, ¹³ C NMR: DS _pr =1.18, DSOH=1 .82, C2DS=0.28, C3DS=0.31 , C6DS=0.59. Intermediate 4 (CPr, DS _pr = 1 .40)

Int 4 was prepared by adapting the procedure for the preparation of Int 1 , except that N2H4.H2O (1 .57 mol eq) and AcOH (0.35 mol eq) were added to Eastman™ CAP482-20 (1.0 mol eq). ¹ H NMR, ¹³ C NMR: DS _pr =1.40, DSOH=1 .60, C2DS=0.32, C3DS=0.44, C6DSc6=0.63.

Intermediate 5 (CPr, DS _pr = 1 .64)

Int 5 was prepared by adapting the procedure for the preparation of Int 1 , except that N2H4.H2O (1 .25 mol eq) and AcOH (0.29 mol eq) were added to Eastman™ CAP482-20 (1.0 mol eq). ¹ H NMR, ¹³ C NMR: DS _pr =1.64, DSOH=1 .36, C2DS=0.41 , C3DS=0.52, C6DS=0.71.

Intermediate 6 (CPr, DS _pr = 1.10)

Int 6 was prepared by adapting the procedure for the preparation of Int 1 , except that N2H4.H2O (1 .94 mol eq) and AcOH (0.42 mol eq) were added to Eastman™ CAP482-20 (1.0 eq). ¹ H NMR, ¹³ C NMR: DS _pr =1.10, DSOH=1 .90, C2DS=0.23, C2DS=0.30, C6DS=0.58.

Intermediate 7 (CPr2EH, DS _pr = 1.13 and DS2EH = 0.49)

To a 4-neck jacketed resin kettle reaction flask under a nitrogen atm with overhead mechanical stirring was added anhydrous DMAC (1 .86 mol eq) and NMI (0.39 mol eq). Int 1 (0.089 mol eq) was added to the RM, and the RM was stirred (30°C) for 48 h. Then 2-EHCI (0.52 mol eq) in DMAC (0.089 mol eq) was added dropwise over 25 min. The RM was stirred (70°C) for 16 h, and the crude product was precipitated by the addition of water (4 L). The solid was collected, continuously washed with deionized water for 6 h, and dried in vacuo (55°C) overnight to give the title compound. ¹ H NMR and ¹³ C NMR: DSp _r =1 .13, DS ₂ EH=0.49, DSOH=1 .38, C2DS=0.38, C3DS=0.40, C6DS=0.85.

Intermediate 8 (Cellulose Acetate Proprionate, DSA _C =0.1 7, DS _pr =1 .66, DSOH =1.17)

Int 8 was prepared as described in US20090096962A (Ex 18). Intermediates 9 (CPr, DSp _r =1.15) and 10 (Cellulose Propionate, DSp _r =1.41 )

Int 9 and 10 were synthesized by adapting the procedure for the synthesis of Int 1 by N2H4 H2O and AcOH. The DSp _r was determined by ¹ H and ¹³ C NMR.

Example 3 (CPrBz, Dsp _r = 1.15, DSBZ = 1.13)

To a stirred mixture RB flask containing DMAC (172 mL, 21 .2 mol eq) and 1 -methylimidazole (32 mL, 4.5 mol eq.) in a nitrogen atm, was added Int 2 (20 g, 1 .0 mol eq) which was dried in vacuo overnight. The RM was stirred for 4 h at 50°C, cooled to 26°C, and then BzCI (14.2 g, 1.15 mol eq in DMAC (14 mL)) was slowly added into the RM over 1 h. The RM was stirred for 14 h at 26°C. The crude product was precipitated iPrOH (2.2 L), and the solids was washed with water (2x500 mL), washed continuously with deionized water for 5 h, and dried in vacuo overnight to provide the title compound. ¹ H NMR and ¹³ C NMR: Dsp _r = 1.15, DSBZ = 1.13 (Table 3).

Ex 4 - Ex 11 Ex 25, EX26, EX27, and EX28 were prepared by adapting the procedure for the preparation of Ex 3 except different SM and BzCI levels were used as shown in Table 2. The compounds were characterized with ¹ H NMR and ¹³ C NMR as shown in Table 3.

Table 2 provides the preparation conditions of Ex 3-11 .

Table 2

Table 3 provides the NMR characterization of Ex 3-11 and Ex 25. Doesn’t work was prepared by adapting the procedures described herein.

Table 3.

Example 12 (CprAcBz, Dsp _r = 1 .66,DSA _C = 0.17, DSBZ = 0.86)

Ex 12 was prepared by adapting the procedure for the preparation of Ex 3, except that Int 8, (1 .0 eq, 20 g, CacPr, DSA _C 0.17 and DSp _r = 1 .66) and BzCI (10.2 g, 0.95 eq) was used. ¹ H NMR and ¹³ C NMR: Dsp _r = 1 .66, DSA _C = 0.17, DSBZ = 0.86 (Table 4).

Table 4 provides the NMR characterization of Ex 12.

Table 4.

Examples 13 (CPr2EHBz, Dspr = 1 .1 3,DSA _C = 0.49, DSBZ = 0.96) and 14 (CPr2EHBz, Dspr = 1 .13,DSA _C = 0.49, DSBZ = 1.02)

Ex 13 and 14 were prepared by adapting the procedure for the preparation of Ex 3. For Ex 13, Int 7 (10 g, 1.0 mol eq) and BzCI (5.1 g, 0.98 mol eq) were used, and for Ex 14, Int 7 (10 g, 1.0 mol eq) and BzCI (0.97 mol eq) were used.

Table 5 provides the NMR characterization of Ex 13 and 14.

Table 5.

Example 15 (CPrBz, Dspr = 1 .54, DSBZ = 0.63)

Ex 15 was prepared by adapting the procedure for preparation of Ex 3, except that Int 1 was used. After Int 1 (20 g, 1 .0 mol eq) was fully dissolved, BzCI (1 .87 g, 0.15 mol eq) in DMAC (2 mL) was added over 1 h at 26°C, and the RM was stirred for 1 h. at 26°C Then PrCI (3.95 g, 0.5 mol eq) in DMAC (3.7 mL) was added over 1 h at 26°C and stirred for 1 h. Then BzCI (6.09 g, 0.5 mol eq) in DMAC (5 mL) was added over 1 h at 26°C, and the RM was stirred for 14 h. The product was purified as described in the procedure for the preparation of Ex 3.

Example 16 (CPrBz, Dsp _r = 1 .69, DSBZ = 0.63)

Ex 16 was prepared according to the procedure for the preparation of Ex 15 (Ex 3), except that after Int 1 (20 g, 1.0 mol eq) was fully dissolved, PrCI (4.5 g, 0.5 mol eq) in DMAC (5 mL) was added over 1 h at 26°C, and the RM was stirred for 1 h at 26°C. Then BzCI (8.44 g, 0.68 mol eq) in DMAC (9 mL) was added over 1 h at 26°C, and stirred for 14 h at 26°C. The title compound was isolated and purified according to the procedure for the preparation of Ex 3.

Example 17 (CPrNp, Dsp _r = 1 .68, DSN _P = 0.46)

Ex 17 was prepared by adapting the procedure for the preparation of Ex 16, except that Int 3 was used. After Int 3 (20 g, 1 mol eq) was fully dissolved, PrCI (4.45 g, 0.55 mol eq) in DMAC (4.75 mL) was added over 1 h at 26°C, and the RM was stirred for 1 h at 26°C. Then NpCI (0.5 mol eq) in DMAC (8.6 mL) was added over 1 h at 26°C, and the RM was stirred for 14 h at 26°C. The title compound was isolated and purified as described in the procedure for the preparation of Ex 3.

Example 24 (CPrBz, Dsp _r = 1 .60, DSBZ = 0.92)

EX 24 was prepared was prepared according to the procedure for the preparation of Ex 15, except that Int 3 was used. After Int 3 (20 g, 1 .0 mol eq) was fully dissolved, PrCI (3.85 g, 0.45 mol eq) in DMAC (5 mL) was added over 1 h at 26°C, and the RM was stirred for 1 h at 26°C. Then BzCI (10.72 g, 0.90 mol eq) in DMAC (9 mL) was added over 1 h at 26°C, and stirred for 14 h at 26°C. The title compound was isolated and purified according to the procedure for the preparation of Ex 3.

Table 6 provides the NMR characterization of Ex 15 - 17, and Ex 24. Ex 24 were prepared by adapting the procedures described in this application. Table 6.

Example 18 (CPr2EHF, Dsp _r = 1.18, DS2EH = 0.36, DSF = 0.99) Int 3 (1 15 g, 1 mol eq) was added to a mixture of DMAC (931 g) and NMI

(186 g) under a nitrogen atm in a 4-neck resin kettle containing, and the RM was stirred for 4 h at 32°C. The RM was cooled to 26°C, and 2-EHCI (31 .93 g, 0.4 mol eq) dropwise over 60 min, and the RM was stirred at 26°C for 2 h. Then FCI (71.65 g, 1.09 mol eq based on Int 3) in DMAC (85 g) was dropwise over 120 min, and the RM was stirred for 12 h at 26°C. The crude product was precipitated with MeOH (2 L), then the solid was filtered and washed continuously with deionized water for 5 h. The material was dried in vacuo overnight at 55°C to provide the title compound. ¹ H NMR, ¹³ C NMR: DSp _r =1 .18, DS2EH=0.36; DSF=0.99; DSOH=0.51 ; C2DS=0.88; C3DS=0.65; C6DS=0.97. Table 7 provides the NMR characterization of Ex 18.

Table 7.

Example 19 (CCrBz, Dscr = 1 .39, DSBZ = 1 .33)

General procedure was described in Application WO2019190756A1 (Preparation of Intermediate 1 and Example 1 ).

Step (1 ) Preparation of Intermediate 11 Cellulose Crotonate

1 ARY cellulose pulp (70 g, 1 .0 eq 5 wt.%) was added to a cooled (25°C) jacketed reaction kettle. Then a solution of TFAA (151 g, 1 .67 mol eq) in trifluoroacetic acid (1 180 g, 24 eq) was added to the cooled cellulose solid with overhead stirring. After the addition was complete, the RM was heated at 55°C, stirred for 16 hr, and then cooled to rt. Then, a solution of trans-crotonic acid (52.0 g, 1.4 mol eq), TFA (10 mL), and trifluoroacetic anhydride (154 g, 1.7 mol eq) was prepared and stirred for 45 min. The resulting reagent mixture was added to the RM at rt, and the resulting RM was stirred for 8 h. The RM was treated with deionized water (1000 mL) to provide a solid material which was filtered. The solids were suspended in iPrOH and stirred for 30 min and mixture was filtered. The resulting solids were suspended in aq. KOAc (5 M, 2000 mL) and stirred for 36 h. The solids were collected by filtration and washed continuously with deionized water for 8 h, and dried in vacuo (60°C, 12 h) to give the title intermediate. ¹ H NMR, 13C NMR: DScr =1 .39, DSOH=1 .61 , C2DS=0.61 , C3DS=0.72, C6DS=0.05.

Step 2, Preparation of Example 19 Cellulose Crotonate Benzoate.

To an oven-dried 1000 mL jacketed 3-neck round bottomed flask equipped with a mechanical stirrer, Int 11 (20 g, 1 .0 mol eq) followed by pyridine (150 mL) and dimethylacetamide (50 mL) were added to a jacketed round bottom flask under a N2 atm. Was charged using a solids addition funnel under an atm of nitrogen. The RM was heated to 50°C and the mixture was stirred until dissolution of the solids, and then the RM was cooled to 25°C. BzCI (15.08 g, 1 .4 eq) was then added over 2 min at 25°C and the RM was stirred for 30 min followed by stirring at 50°C overnight. Acetone (-150 mL) was added to the RM followed by deionized water (2200 mL) to precipitate the crude product. The crude product was filtered and washed with a 1 :1 solution of iPrOH:water (2x). The crude product was washed with deionized water continuously for at least 5 h, the solids were filter collected and dried in vacuo (22.5 mm Hg, 60°C) overnight. ¹ H NMR, ¹³ C NMR: DScr=1.39, DSBZ=1.33, DSOH=0.29, C2DS=0.83, C3DS=0.89, C6DS=0.99.

Example 20 (CPrBz, Dsp _r = 1 .81 , DSBZ = 0.68)

Ex 20 was prepared by adapting the procedure for the synthesis of Ex 19, except that in Step 1 in the preparation of Int 12 Cellulose Propionate Benzoate, BzOH (0.5 mol eq), TF2O (0.8 mol eq), TFA (10 mL) after stirring for 45 min together were used, and the resulting reagent mixture was added to the reaction mixture and the RM was stirred (45°C) for 3 h. Afterwards, propionic acid (0.8 mol eq) TF2O (0.8 mol eq) and TFA (10 mL) were stirred for 45 min, the resulting reagent solution was added to the RM, and the resulting RM was stirred for 5 h. The Int 12 was obtained after using the work-up described in step 1 for Ex 19. The mixture was added into the reaction kettle at 45°C after the addition of the first mixed anhydride was added and stirred for 3 h. The reaction was allowed to stir for 5 h. ¹ H NMR, ¹³ C NMR: DSp _r =0.81 , DSBZ=0.52, DSOH=1 .67, C2DS=0.64, C3DS=0.63, C6DS=0.05.

In Step 2, Int 12 (1 .0 mol eq) and BzCI (0.15 mol eq) were stirred for 3 h at rt, and then propionic anhydride (1 mol eq) were stirred overnight at 50°C. The title product was isolated as described in step 2 for Ex 19. ¹ H NMR and ¹³ C NMR: DSp _r =1 .81 , DSBZ=0.68, DSOH=0.51 , C2DS=0.86, C3DS=0.76, C6DS=0.87.

Table 8 provides the NMR characterization of Ex 19 - 20.

Table 8.

Example 21, Cellulose Propionate Pivalate Naphthoate CPrPvNp (Dsp _r = 1.18, DSPV = 0.39, DSN _P = 1.18)

Ex 21 was prepared as described in US20170306054 (Ex 12, Table 3).

Example 22, Cellulose Propionate 2-ethylhexaonate Naphthoate CPr2EHNp (Dsp _r = 1.18, DS2EH = 0.40, DSN _P = 1 .26)

Ex 22 was prepared according to the procedure described in US Application No. 62/891561 (Ex 7, Table 9).

Table 9 provides the NMR characterization of Ex 21 - 22.

Table 9.

Film Casting and Stretching

Table 10 provides the general film compositions, with or without component A; solvent system used to prepare casting solutions; temperature used to stretch the cast films, if stretched; and the stretch ratios for the films. The stretch ratio is provided with either an “x” or a “c.” An “x” indicates that the films were stretched along the machine direction with two sides held and the other two sides free. A “c” indicates that the films were stretched along the machine direction with all four sides held. A “ratio 1 X ratio 2” indicates that the films were stretched or shink along MD direction at ratio 1 while being stretched or shrunk along TD direction at ratio 2. For example, casting solutions made with cellulose ester, Ex 1 , and with or without Component A (0-20 wt%) were prepared in a 10% acetone in DCM solution.

Regarding Films 18.1 -18.4, Films 21 .1 -21 .3, and Films 22.1 -22.3, the corresponding resin and Component A dissolved in corresponding solvent to prepare corresponding Solution A. Solution of Eastman™ CAP482-20 (90 wt%) and TPP (10 wt%) in 1 :9 EtOH/DCM at solid wt% of 12 wt% was prepared. Solution of CAP482-20 was casted on to glass substrate in a fume hood with relative humidity controlled at 45%~50%. The films were allowed to dry for 45 minutes under a cover pan to minimize rate of solvent evaporation before the pan was removed. Corresponding solution A was casted on to Eastman CAP482-20 films. The two-layer films were allowed to dry for 45 minutes under a cover pan to minimize rate of solvent evaporation before the pan was removed and further to dry for 15 minutes after the pan was removed. Then the two-layer films were peeled from the glass and annealed in a forced air oven for 10 minutes at 100 ^e C. After annealing at 100 ^e C, the film was annealed at a higher temperature (120 ^e C) for another 10 minutes. After the two-layer films were stretched, the top layers were peeled off the bottom layers and measured.

Table 10 provides the components of corresponding solutions and stretching conditions of example films.

Percentages of component A and plasticizers in the films are defined as below. Percentage of component A or plasticizers = weight of component A or plasticizers/ total weight of (cellulose esters, component A, plasticizers and all other non-solvent components added).

Solution concentration is defined as below. Solution concentration = total weight of (cellulose esters, component A, plasticizers and all other components added excluding solvents)/total weight of (cellulose esters, component A, plasticizers, all other non-solvent components added and solvents) For example, for film 1 .3, Resin 1 (8 g, 95 wt%) and Component A (0.421 g, 5 wt%) was added into 1 :9 Acetone/DCM (75.8 g, solution concentration at 10 wt%). The mixture was put on roller until the Resin 1 and Component A were fully dissolved. For example, for film 25.2, Ex 25 (15 g, 88 wt%), Component A (1 .19 g, 7 wt%) and plasticizer Admex 523 (0.85 g, 5 wt%) were added into 5:95 MeOH/DCM (104.7 g, solution concentration at 14 wt%). The mixture was put on roller until the Resin 1 , Component A and plasticizer were fully dissolved.

Table 10.

As shown in Table 11 , compared to the corresponding comparative film samples with negative birefringence or retardation, the invention film samples showed improved wavelength dispersion with negative birefringence or retardation. For examples, Film 1.1 and Film 1.2 (control samples) have R _e (450 nm)/R _e ( 550 nm) between 1.13 to 1.15 and R _e (650 nm)/R _e ( 550 nm) between 0.93 to 0.94. Film 1 .3 to 1.14 and Film 1 .18 to 1.19 have improved wavelength dispersion with R _e (450 nm)/R _e ( 550 nm) between 0.69 to 1 .06 and R _e (650 nm)/R _e ( 550 nm) between 0.95 to 1 .02. Film 1 .3, Film 1 .1 1 and Film 1.13 have R _e (450 nm)/R _e ( 550 nm) between 0.91 to 0.93 and R _e (650 nm)/R _e ( 550 nm) at 0.98. Film 1 .5 and 1 .6 showed further tuned wavelength dispersion with R _e (450 nm)/R _e ( 550 nm) between 0.69 to 0.78 and R _e (650 nm)/R _e ( 550 nm) from 1 .01 to 1.02.

As shown in Table 11 , the invention film samples have Nz coefficient from -3.0 to 3.0 with improved wavelength dispersion. Specifically, Film 1 .5, 1 .7, 1 .10, 1.1 1 , 2.6, 3.3, 3.5, 4.5, 4.6, 4.7, 5.4, 7.4, 8.3, 8.4, 9.1 , 9.2, 10.1 , 10.2, 12.4, 12.5, 15.3, 16.3, 17.7, 24.1 and 25.1 have Nz coefficient from 0.2 to 0.8, which can be used as Z films. Those invention film samples have improved wavelength dispersion with R _e (450 nm)/R _e (550 nm) smaller than 1 .02, R _e (650 nm)/R _e (550 nm) equal to or greater than 0.95, ratio of Re (589 nm)/d (nm) multiplied by 1000 is from -6.0 to -0.5. More specifically, Film 1 .7, 2.6, 3.3, 3.5, 4.6, 4.7, 5.4, 7.4, 8.3,

8.4, 9.1 , 10.1 , 10.2, 12.4, 12.5, 15.3, 16.3, 17.7 and 25.1 have improved Nz coefficient from 0.3 to 0.7. Further more specifically, Film 1 .7, 3.5, 8.3, 8.4, 15.3 and 25.1 have further improved Nz coefficient from 0.4 to 0.6. Further more specifically, Film 15.3, 16.3 and 17.7 have Nz coefficient from 0.3 to 0.7 and further improved wavelength dispersion with R _e (450 nm)/R _e (550 nm) equal to or smaller than 0.90, R _e (650 nm)/R _e (550 nm) equal to or greater than 0.99, ratio of Re (589 nm)/d (nm) multiplied by 1000 is from -6.0 to -0.5.

Film 1.3, 1.19, 2.5, 3.4, 5.3, 6.3, 7.5, 9.3, 10.3, 1 1.1 , 1 1.3, 11.4, 13.4, 17.6,

18.4, 19.4, 19.6, 20.3 have Nz coefficient from 0.8 to 1 .2, which can be used as - A films. Those film samples have improved wavelength dispersion with R _e (450 nm)/R _e (550 nm) equal to or smaller than 1 .05, R _e (650 nm)/R _e (550 nm) equal to or greater than 0.95, ratio of R _e (589 nm)/d (nm) multiplied by 1000 is from -6.0 to -0.5. More specifically, Film 1 .3, 6.3, 7.5, 1 1.1 and 17.6 have further improved wavelength dispersion with R _e (450 nm)/R _e (550 nm) equal to or smaller than 0.95, R _e (650 nm)/R _e (550 nm) equal to or greater than 0.97.

Table 11 also shows examples (Film 21 .1 to 22.3) that don’t have improved wavelength dispersion compared to the control samples.

Table 11 provides additional data on the films that were prepared. The film thickness after stretching, R _e measured at 589 nm, Rth measured at 589 nm, R _e (450 nm)/R _e (550 nm), N _z Coefficient, R _e /d, Rth/d are provided.

Table 11 .

I means invention, C means comparative, DW means doesn’t work.

As shown in Table 12, plasticizers were incorporated into the films. For films in Table 12, Nz coefficient between 0.3 to 0.7 are obtained. More specifically, Re(450nm/550nm) values for the example films are not greater than 1.0, ratio of R _e (589 nm)/d (nm) multiplied by 1000 is from -6.0 to -0.5.

Table 12.

Preparation of Film 1.20 Ex 1 (16 g) and Tinuvin 1577 (0.842 g) was added into 123 g dichloromethane: methanol = 95 : 5 (wt: wt). Tinuvin 1577 is calculated as 5 wt% in the film while Ex 1 is 95 wt% in the film. The mixture was put on roller until Ex 1 and Tinuvin 1577 were fully dissolved. The solution prepared above was cast onto a glass plate using a doctor blade to obtain a film with the desired thickness. Casting was conducted in a fume hood with relative humidity controlled at 45%~50%. After casting, the film was allowed to dry for 120 min under a cover pan to minimize rate of solvent evaporation before the pan was removed. The film was allowed to dry for 30 min then the film was peeled from the glass and annealed in a forced air oven for 10 min at 100 ^e C. After annealing at 100 ^e C, the film was annealed at a higher temperature (120 ^e C) for another 10 min.

The films were cut into squares or rectangles and stretched at conditions shown in Table 13.

Preparation of Film 26.1 to 28.1 in Table 13 and 14

Film 26.1 to 28.1 were prepared following the procedure of preparation of Film 1.20 except that different component A and plasticizers were used as shown in Table 13.

As shown in Tables 13 and 14, example films composed the regioselective cellulose esters and component A with or without plasticizers were stretched between 100 to 220 °C and showed the thickness (“d”) in microns is from 10 pm to 200 pm, R _e (589 nm) that is -120 nm to - 350 nm, Rth(589 nm) that is -100 nm to 100 nm, Nz factor from 0.2 to 0.8, the film exhibits a R _e (450/550) that is 0.7 to 1 .20, the film exhibits a R _e (650/550) that is 0.9 to 1 .25.

More specifically, film 1.20, 26.2, 26.3, 26.4, 26.5, 26.6, 26.7, 26.8, 26.9, 26.10, 26.11 , 26.12, 26.13, 26.14, 27.1 , 27.2, 27.3, 27.4, 27.5, 27.6 and 28.1 were stretched between Tg - 30 °C to Tg + 50 °C and showed, R _e (589 nm) that is -120 nm to - 350 nm, Rth(589 nm) that is -100 nm to 100 nm, Nz factor from 0.3 to 0.7, the film exhibits a R _e (450/550) that is 0.7 to 1 .05, the film exhibits a R _e (650/550) that is 0.9 to 1 .25. Table 13.

*c means the films were stretched constrainedly; x means the films were stretched non- constrainedly; #1 x # 2 means the films were stretched at ratio # 1 along MD direction while shrinking or being stretched at ratio # 2 along TD direction Table 14.