TECHNOLOGICAL FIELD

The invention generally relates to novel fiber and functional materials made therefrom.

BACKGROUND

Regenerated cellulose fiber is regenerated fiber of cellulose II. The raw material is natural plant cellulose. Compared with synthetic fiber, it is environmentally friendly and recurrent, and it does not contain harmful substances. It is more low-carbon and safer than synthetic fiber. At the beginning of the 20 ^th century, the entire world faced cotton shortage. Viscose was a new type of regenerated cellulose fiber produced to replace cotton fiber, and in the long run, to replace the synthetic petroleum-based products and their related significant environmental hazards.

Viscose (rayon), with cotton cellulose as its raw material, is made into sodium sulfate cellulose solution after going through such procedures as alkalization, aging and sulfuration, concluded with wet spinning. Through this special processing, cotton fiber is processed into new type of fiber which has similar tissue elements with cotton. Sustainable production and cheapness of the raw material has become a key breakthrough in textile industry. Yet, due to its limitation in production technology, its manufacturing process still causes inevitable pollution.

Modal fiber is the representative of the second generation of regenerated cellulose fiber, first developed and produced in 1980s. Cellulose pulp is made out of wood pulp (e.g. zelkova schneideriana), spinning and cooling are conducted after multiple procedures, and eventually green cellulose fiber with high-tech content is solidified. Modal fiber not only inherits the environmentally friendly advantage of viscose, but also pays greater attention to ecological balance in production processes compared with the first generation of viscose.

The short fiber represented by Tencel fiber and long fiber by Newcell are typical products of the third generation of regenerated cellulose fiber. For Tencel fiber, also known as ' Lyocelf , needle-leave trees are used as the raw material to produce cellulose

INCORPORATED BY REFERENCE (RULE 20.6) pulp, which is then mixed with NMMO solution and heated to complete dissolution. New type of regenerated cellulose fiber is formed after procedures such as cleaning. Compared with the two former generations, Tencel fiber is not only greatly improved in fabric performance such as strength, moisture absorption, stability, drapability and comfort, but also complies with modem demands of green technologies.

Regenerated cellulose is regarded to play a leading role as a replacement for cotton and synthetic fibers for textile and non-woven applications, with industrial uses such as in various types of filters, ropes, abrasive materials, protective suiting material, and bandages. Specific derivatives (e.g., oxidized) have pharmaceutical and medical applications, e.g., wound dressing, tissue engineering, controllable drug delivery system, blood purification, etc.

Increased demand for high-performance materials with tailored mechanical and physical properties, has led to further developments in regenerated cellulose technologies. Over the past few years, nanocellulose (NC), cellulose in the form of nanostructures, has been proved to be one of the most prominent green materials of modern times. NC materials have gained growing interests owing to their attractive and excellent characteristics such as abundance, high aspect ratio, better mechanical properties, renewability, and biocompatibility. The abundant hydroxyl functional groups allow a wide range of functionalizations via chemical reactions, leading to developing various materials with tunable features.

Typically, nanocellulose can be categorized into cellulose nanocrystals (NCC), cellulose nanfibrils, and bacterial cellulose (NFC). A number of nanocellulose forms can be produced using different methods and from various cellulosic sources. The morphology, size, and other characteristics of each nanocellulose class depend on the cellulose origin, the isolation and processing conditions as well as the possible pre- or post-treatments.

Owing to the hydrophilic nature of nanocellulose and its surface OH groups, the surface chemistry can be tuned chemically, physical interactions, and biological approaches. Surface functionalization can be carried out during the preparation step or post-production. These modifications can lead to attaining desirable properties, which, in turn, enhance their effectiveness for a given application.

Cellulose acetate, used in fiber-based materials such as cigarette filter, although biodegradable, takes years to disappear from the environments (up to 15 years).

INCORPORATED BY REFERENCE (RULE 20.6) Cellulose acetate fibers, like other microplastics, are also a common contaminant found throughout the world’s ecosystems and is one of the most significant causes of marine pollution.

GENERAL DESCRIPTION

In a global market in which nearly 10 trillion cigarette sticks are manufactured every year, cigarette filters become a major concern to the environment. Of the filtered cigarettes 80% or more are made from cellulose acetate fibers, less than 20% of the filters are made of unique materials, and the remaining are made from polymeric materials such as polypropylene.

Cigarette sticks are typically provided with "filter tow" that is structured of crimped fibers of cellulose acetate, encased in a tipping paper. One of the most pressing environmental concerns is the filters’ biodegradability, or rather slow rate of biodegradability. It is not only a visual concern, but more so a health risk as toxins adsorbed by used cigarette filters have been found to leach into the environment, have been found to pollute the oceans and have been found to generally be a potential biohazard.

The present invention seeks to address these problems by a novel biodegradable cigarette filter that is configured not only to easily degrade by, e.g., enzymes present in the environment, but more so improve the user’s experience and reduce transport of toxic materials from the burnt tobacco through the filter and into the user’s lungs. By constructing the cigarette tow with fibers composed of regenerated cellulose fibers that are chemically associated with a nanocellulose material, a more biodegradable and further improved tow is provided.

Thus, in a first aspect, there is provided a regenerated cellulose fiber for use in the manufacture of a cigarette filter tow, the fiber being chemically associated with at least one nanocellulose, as defined herein.

The invention further provides a regenerated cellulose fiber for use in the manufacture of a cigarette tow, the fiber being coated with one or more layers/coates/shells of a nanocellulose material.

Further provided is a composite of regenerated cellulose and a nanocellulose, the composite being in a form of a fiber, for use in the manufacture of a cigarette tow.

INCORPORATED BY REFERENCE (RULE 20.6) As used herein, the term “fiber” refers to a single filament of a regenerated cellulose that may be of various lengths and which is associated with a nanocellulose as disclosed herein. The “regenerated cellulose” is a material as known in the art, typically a cellulose produced by converting the naturally produced cellulose to a soluble cellulosic derivative that is subsequently regenerated. The fibers of the regenerated cellulose may be of a length extending between 0.5 cm and Thousands of meters and ranging in thickness between 0.5 micron and 500 microns. When processed into a final product, or for the purpose of treating same in accord with the invention, the fiber may be cut to any length.

As noted herein, fibers of regenerated cellulose are treated in the presence of a nanocellulose to bring about association between the two. The association is typically covalent, while ionic association or hydrogen bonding may also occur in place or in addition to covalent bonding. Notwithstanding the association, the regenerated cellulose becomes coated with one or more layers or coats or shells of the nanocellulose. After initial association between the regenerated cellulose and the nanocellulose, further coatings may be formed by association of nanocellulose to nanocellulose already on the surface of the bare, partially modified or modified regenerated cellulose.

The fibers may be prepared by a variety of technologies. According to one nonlimiting process, a regenerated cellulose fiber may be coated reel-to-reel with a nanocellulose material. As the nanocellulose material comprises primary reactive sites (such as hydroxyl groups), they possess high surface area to volume ratio, making the nanocellulose highly reactive and easy to be functionalized. Cellulose nanocrystals (CNC), as an example of such a nanocellulose material, are chemically modified in order to impart stable positive or negative electrostatic charges on their surfaces for a better distribution of particles and to enhance their compatibility. The association via, e.g., crosslinking is achieved by passing the fibers and the nanocellulose via a hot air chamber. Multilayers with different actives maybe applied on the fibers. The fibers may then be formed into bundles or composites used for the production of various types of products.

To achieve proper association and coating of the regenerated cellulose fibers, compositions which include the nanocellulose along with a poly -carboxylic acid may be used. Such poly-carboxylic acids may be 1,2,3,4-butane tetracarboxylic acid (BTCA) or citric acid. Any other suitable carboxylic acid capable of generating ester

INCORPORATED BY REFERENCE (RULE 20.6) bonds to crosslink the nanocellulose to the regenerated cellulose or the nanocellulose to itself may be used. Catalysts such as and sodium hypophosphite (SHP) may also be used.

The “nanocellulose” used is a material selected from cellulose nanocrystals (CNC), microfibrillated cellulose (MFC), nanofibrilar cellulose (NFC), microcrystalline cellulose (MCC) and combinations thereof. In some embodiments, the nanocellulose is CNC.

CNC, also known as nanocrystalline cellulose (NCC) and cellulose nanowhiskers, is a fiber produced from cellulose, wherein the CNC is typically a high- purity single crystal. CNC fibers constitute a generic class of materials having mechanical strengths equivalent to the binding forces of adjacent atoms. The resultant highly ordered structure produces not only unusually high strengths but also significant changes in thermal, electrical, optical, magnetic, and other properties. The tensile strength properties of CNC are far above those of the current high volume content reinforcements and allow the processing of the highest attainable composite strengths.

CNC may be produced from cellulose or any cellulose containing material or from fibrillated cellulose by means known in the art. The CNC may be the material having CAS number 9004-34-6 or its sulphated form having CAS number 9005-22-5.

In some embodiments, the CNC is prepared according to procedures provided, for example, in WO 2012/014213, WO 2015/114630, and in US applications derived therefrom, each being herein incorporated by reference.

As known in the art, cellulose nanofibrils (CNF or NFC) are cellulosic materials composed of at least one primary fibril, containing crystalline and amorphous regions, with aspect ratios usually greater than 50. Their length is 0.1-5 pm and their diameter is 5-60 nm. Similarly, cellulose microfibrils (CMF or MFC) are cellulosic materials containing crystalline and amorphous regions, with aspect ratios usually greater than 50. Their length is few micrometers and their diameter is larger than 100 nm. CMF can contain some fraction of CNF.

In some embodiments, the cellulose nanomaterial is characterized by having at least 50 percent crystallinity. In some embodiments, the cellulose nanomaterial is monocrystalline. In some embodiments, the cellulose nanomaterial is high purity monocrystalline material.

INCORPORATED BY REFERENCE (RULE 20.6) In some embodiments, the nanocrystals of the nanomaterial have a length of at least about 50 nm. In other embodiments, they are at least about 100 nm in length or are at most 1,000 nm in length. In other embodiments, the nanocrystals are between about 100 nm and 1,000 nm in length, 100 nm and 900 nm in length, 100 nm and 600 nm in length, or between 100 nm and 500 nm in length.

In some embodiments, the nanocrystals are between about 10 nm and 100 nm in length, 100 nm and 1,000 nm, 100 nm and 900 nm, 100 nm and 800 nm, 100 nm and 600 nm, 100 nm and 500 nm, 100 nm and 400 nm, 100 nm and 300 nm, or between about 100 nm and 200 nm in length.

The nanocrystals may be selected to have an averaged aspect ratio (length-to- diameter ratio) of 10 or more. In some embodiments, the averaged aspect ratio is between 10 and 100, or between 20 and 100, or between 30 and 100, or between 40 and 100, or between 50 and 100, or between 60 and 100, or between 70 and 100, or between 80 and 100, or between 90 and 100, or between 61 and 100, or between 62 and 100, or between 63 and 100, or between 64 and 100, or between 65 and 100, or between 66 and 100, or between 67 and 100, or between 68 and 100, or between 69 and 100.

In some embodiments, the fibers are collected into a bundle and treated to form the cigarette tow. The tow may include, in addition to the fibers, one or more additives. The additives are typically not chemically associated with any one fiber in the bundle. However, in some implementations, fibers used according to the invention may be further modified to associate to one or more functional material. Whether chemically or physically associated with a fiber or added to a collection of fibers comprising or consisting or constructed of a fiber according to the invention, the additive or functional material may be selected amongst plasticizers; chelating materials; adsorbing materials such as carbon black and charcoal; carbonaceous materials; flavoring materials; sweeteners; coloring materials or pigments; fragrant materials; flame retardants such as sodium tugstanate; taggant materials; ionic materials; reinforcing materials; pH stabilizers or modifiers; desiccants; antioxidants; solidifiers, UV stabilizers, polymeric materials, and any other material selected to endow the fiber or a collection of fibers with one or more additional attribute.

In some cases, the additive or functional material is contained within the bundle or collection of fibers or between layers of the nanocellulose, e.g., CNC formed on the surface of the regenerated cellulose fiber. In some other cases, at least a portion of the

INCORPORATED BY REFERENCE (RULE 20.6) additives or functional material may be chemically associated with the CNC or the regenerated cellulose. Thus, the invention also provides a regenerated cellulose fiber that is chemically associated to both a nanocellulose, as defined, and to a functional material selected as above, for use in the manufacture of a cigarette tow.

The invention also provides a filter tow (a cigarette filter) that is configured for the conventional and electronic cigarettes. Use of a regenerated cellulose coated with multilayers of a nanocellulose, e.g. , CNC, in the presence or absence of any one or more additives or functional materials, as defined herein contributes to the Young modulus of the fiber (stiffness), reduces surface roughness, thereby leading to a better control of porosity in achieving desirable tar/nicotine retention and pressure drop values. Due to the ester bond formed between the regenerated cellulose and the nanocellulose, the filter is readily biodegradable or compostable, having increased sensitivity towards hydrolysis by naturally occurring esterase enzymes present in the environment, e.g., soil, and thus, provides a viable alternative to filters manufactured of fine cellulose acetate.

In the conventional cigarettes, the filter is wrapped in a plug wrap. The filter may be joined via a tipping paper to a tobacco tow consisting of a loose tobacco mixture and wrapped in a cigarette paper. In electronic cigarettes, tire inhaler (also known as 'cartridge', a disposable non-refillable plastic mouthpiece) contains an absorbent material that is saturated with a liquid solution containing nicotine. In many cases, the absorbent material can comprise woven fibers or a sponge-like material according to the invention, per se, or with additional general and/or selective absorbent material as above. The absorbent material may be shaped as a hollow cylinder disposed adjacent to an exterior of a tube encircling the same, and may be in fluid communication with a vaporizing device.

Filter tows of the invention may be provided separately or part of a complete cigarette.

Thus, the invention provides a cigarette provided with a filter tow according to the invention.

Also provided is a kit or a commercial product containing a plurality of cigarette tows according to the invention, rolling papers and tobacco, and optionally further instructions to roll a cigarette.

INCORPORATED BY REFERENCE (RULE 20.6) Also provided is an electronic cigarette adapted to receive a filter tow according vention.

Fiber tows according to the invention may be manufactured as known in the art.

INCORPORATED BY REFERENCE (RULE 20.6)