Field of the Invention

The present invention relates to a solid cleaning composition for use in cleaning surfaces, in particular for cleaning submerged surfaces such as toilet bowls.

Background of the Invention

There is a need to provide consumers with cleaning compositions that are able to clean and disinfect household surfaces, for example surfaces in the kitchen and bathroom. Particularly, there is a need for cleaning compositions that are effective on surfaces submerged in water, for example in toilet bowls, kitchen sinks, washing machines for laundry and in dishwashing machines.

Cleaning compositions known in the art for cleaning toilet bowls are effective in maintaining a hygienic surface through use of antimicrobial agents, but typically such cleaning compositions, tend to have low cleaning efficacy on submerged surfaces. The present inventors have invented a solution to such a problem which is published as WO2021/180936. This involves use of a unit dose cleaning composition that comprises a cationic surfactant and a combination of selected substituted phenol, aliphatic terpene alcohol and unsaturated terpene in an effervescent system. Such compositions when used in a submerged body like a toilet bowl produces a foam that ensures that the cleaning and disinfecting actives are in contact with the vertical surfaces of the bowl for delivering the desired benefit. A higher foam height which is stable for a longer time ensures better cleaning and disinfection. While the composition disclosed in the aforementioned patent publication is effective in stain and limescale removal there is a need to deliver superior foaming to ensure enhanced cleaning and disinfection. When the composition is delivered in a unit dose solid form, it is also desirable that the solid composition dissolves quickly in water. The present inventors during the course of developing such a composition found that these desired benefits could be delivered through a composition comprising a solid peroxide compound like peroxydone, calcium peroxide or urea peroxide in combination with two types of surfactants. Solid peroxide composition for use in cleaning application has been reported in the past e.g. in US2008/0045593. While the use of solid peroxide compounds and some surfactants are disclosed, they are found to be not suitable for use in submerged surfaces like toilet bowls. It is an object of the present invention to provide for a composition that delivers a cleaning and disinfecting benefit to submerged surfaces.

It is another object of the invention to provide for a composition that dissolves quickly in water.

It is yet another object of the present invention to provide for such a composition that delivers high amount of foam which is stable and creamy.

Summary of the Invention

The first aspect of the invention provides for a solid cleaning and disinfection composition comprising

(a) a solid peroxide compound;

(b) one or more primary surfactant selected from alkyl sulphate surfactant, alkyl benzene sulphonate surfactant, alkyl ether sulfate surfactant and soap; preferably alkyl sulphate surfactant; and

(c) one or more secondary surfactant selected from fatty acyl isethionate, sodium lauroyl taurate, sodium lauroyl cocoate, and coco amido propyl betaine ; preferably fatty acyl isethionate.

Another aspect of the present invention provides for a method of cleaning a surface, preferably a toilet bowl, comprising the step of contacting the composition of the invention with water on said surface.

Detailed Description of the Invention

For the avoidance of doubt, any feature of one aspect of the present invention may be utilised in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of” or "composed of". Thus, the term "comprising" is meant not to be limiting to any subsequently stated elements, but rather to optionally also encompass nonspecified elements of major or minor functional importance. In other words, the listed steps or options need not be exhaustive. Whenever the words "including" or "having" are used, these terms are meant to be equivalent to "comprising" as defined above. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about". Unless specified otherwise, numerical ranges expressed in the format "x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "x to y", it is understood that all ranges combining the different endpoints are also contemplated. Unless specified otherwise, amounts as used herein are expressed in percentage by weight based on total weight of the composition and is abbreviated as “wt%”.

The composition comprises a sold peroxide compound. The preferred solid peroxide compound is selected from one or more of peroxydone, calcium peroxide and urea peroxide, preferably peroxydone. They have the structures as given below:

Peroxydone which is a PVP polymer complex.

CaO ₂ • XH ₂ O

Calcium peroxide.

Urea peroxide and peroxydone when in contact with water release hydrogen peroxide. Calcium peroxide releases hydrogen peroxide when in contact with acidic water. Of the solid peroxide compounds, peroxydone is preferred for use in the composition of the present invention. Urea peroxide is available as urea hydrogen peroxide adduct from Alfa Aesar (Thermo Fisher Scientific), calcium peroxide from Sigma Aldrich and peroxydone as Peroxydone™ XL-10 from Ashland.

The solid peroxide compound is preferably included in 0.1 to 10%, preferably 0.5 to 5%, further more preferably 1 to 4% by weight of the composition.

The composition of the invention comprises one or more primary surfactant selected from alkyl sulphate surfactant, alkyl benzene sulphonate surfactant, alkyl ether sulfate surfactant and soap.

A preferred primary surfactant is alkyl sulphate surfactant. The alkyl sulphate surfactant for inclusion in the composition of the invention preferably has 10 to 18 carbon atoms, more preferably 10 to 12 carbon atoms. The surfactant has a counterion which is an alkali metal such as sodium or potassium; or an ammoniacal counterion such as monoethanolamine, (MEA) diethanolamine (DEA) or triethanolamine (TEA). Preferably it is sodium or potassium, most preferably it is sodium.

Other primary surfactant may be alkyl benzene sulphonate (LAS). The chemical structure of LAS is

Yet another primary surfactant may be an alkyl ether sulphate surfactant. The alkyl ether sulphate surfactant for inclusion in the composition of the invention preferably has 10 to 18 carbon atoms, more preferably C10 to C12 carbon atoms. The alkyl ether sulphate surfactant preferably has one to ten ethylene oxide or propylene oxide units per molecule, preferably one to three ethylene oxide units per molecule. The surfactant has a counterion which is an alkali metal such as sodium or potassium; or an ammoniacal counterion such as monoethanolamine, (MEA) diethanolamine

(DEA) or triethanolamine (TEA). Preferably it is sodium or potassium, most preferably it is sodium. The most preferred surfactant of this class for inclusion in the composition is sodium laureth sulphate 1 EO.

Yet another primary surfactant may be soap. The soap is preferably C8-C24 soap, more preferably C10-C20 soap and most preferably C12-C18 soap. The soap may or may not have one or more carbon-carbon double bond or triple bond. The cation of the soap may be alkali metal, alkaline earth metal or ammonium. Preferably, the cation of the soap is selected from sodium, potassium or ammonium. More preferably the cation of the soap is sodium or potassium. The soap may be obtained by saponifying a fat and/or a fatty acid. The fats or oils generally used in soap manufacture may be such as tallow, tallow stearines, palm oil, palm stearines, soya bean oil, fish oil, castor oil, rice bran oil, sunflower oil, coconut oil, babassu oil, palm kernel oil, and others.

The primary surfactant is preferably included in 0.1 to 5%, more preferably 0.5 to 4 % by weight of the composition.

The composition of the invention comprises one or more secondary surfactant selected from fatty acyl isethionate, sodium lauroyl taurate, sodium lauroyl cocoate, and coco amido propyl betaine; preferably fatty acyl isethionate. Fatty acyl isethionates (e.g. cocoyl isethionates) surfactant "products" are defined as mixtures of anionic acyl isethionate surfactants and fatty acids/fatty acid soaps. They are highly desirable in personal care skin or hair cleansing products, particularly in personal care products, because they lather well, are mild to the skin and have good emollient properties. Typically, fatty acid isethionate surfactant products are produced by esterification of fatty acids or by reaction of fatty acid chloride having carbon chain length of C8 to C20 with isethionate. A typical surfactant product containing fatty acyl isethionate contains about 40 to 95 wt.% acid isethionate, and 5 to 50 wt.%, typically 10 to 40 wt.% free fatty acid, in addition to isethionate salts, typically at less than 5%, and trace (less than 2 wt.%) of other additives. The secondary surfactant is preferably included in the composition at 0.1 to 5 wt%, more preferably at 0.5 to 4 wt%.

The composition preferably comprises an acidic component. The acidic component is preferably selected from an organic acid, for example a carboxylic acid, organic acid salts, organic acid anhydrides, inorganic acids, inorganic acid salts, and mixtures thereof. Preferably, the organic acid, and related salts and anhydrides are selected from carboxylic acids having up to 8 carbon atoms. Preferably, the acid component is an organic acid, an acid anhydride, sodium dihydrogen phosphate, disodium dihydrogen pyrophosphate, acid citrate salts, sodium acid sulphite and mixtures thereof, preferably wherein the acid source is an organic acid selected from citric acid, malic acid, tartaric acid, fumaric acid, sulfamic acid, oxalic acid, maleic acid, gluconic acid, succinic acid, salicylic acid, adipic acid and mixtures thereof, more preferably wherein the acid is one or both of citric acid and sulfamic acid.

The composition is preferably delivered in unit dose form. The composition is further preferably delivered as an effervescent system having an acidic component and a basic component.

The basic component is preferably selected from carbonates, bicarbonates, sequicarbonates and mixtures thereof. More preferably, the carbonate component is preferably an alkali metal carbonate, preferably sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, sodium glycine carbonate and mixtures thereof.

The acidic component is present in the effervescent system in an amount preferably ranging from 20 to 80 wt%, more preferably from 20 to 60 wt% and even more preferably ranging from 20 to 40 wt%. The acidic and basic components are included in amounts to achieve rapid, complete solubility of the unit dose. Consequently, the molar ratio of acid component to basic component should be approximately within a range of from about 1 .0:2.0 to about 1.0:4.0.

Preferably, the combination of acidic and basic components should comprise 50 wt% of the unit dose. More preferably, the acidic and basic components comprise at least 75 wt% of the unit dose and most preferably, at least 80 wt% of the unit dose.

The composition of the invention is preferably in unit dose form. Preferably, the unit-dose is a concentrate, capsule, tablet, lozenge or block. Preferably the unit dose is a tablet, lozenge or block.

The composition of the invention preferably has a pH in the range of 2 to 7 preferably 2.5 to 4.5. The pH of the composition of the invention Is measured using the following procedure. A tablet of 25 g is dissolved in 1.5 L of distilled water. The pH of the solution is then measured using a pH meter at 25 °C.

Another aspect relates to a method of cleaning a surface, preferably a toilet bowl, comprising the step of contacting the composition of the invention with water on said surface. Yet another aspect relates to use of the composition of the invention for cleaning a surface, preferably a submerged surface like a toilet bowl.

The invention shall now be exemplified by the following non-limiting examples.

Examples

Examples A, 1, 2: Effect of compositions as per the invention compared to that outside the invention on the various desired benefits:

Compositions as shown in Table -1 were prepared as a tablet.

Table -1

The compositions were tested for the following parameters:

(1) Dissolution time: A Beaker was filled with water to about 60% of its height. A tablet was put in the beaker. A stopwatch was started to note the time. The time to complete dissolution of the tablet till effervescence stops completely was noted. This was noted as the dissolution time.

(2) Foam height: Once the Tablet is completely disintegrated in the water as per the above procedure to measure the dissolution time, the height of the foam was measured and noted down as the foam height. (3) Qualitative attributes like rate of effervescence (marked as fast, medium and slow), foam quality (creamy, light creamy and light) and foam stability (high, medium and low) were observed for each of the compositions.

The data is summarised in Table - 2:

Table - 2:

The data in the above table indicates that compositions as per the invention (Example 1 and 2) were acceptable in terms of dissolution time , rate of effervescence and foam stability while foam height and foam quality of these compositions were superior to that of a conventional composition (Example -A).

The compositions as in Table -1 were used to test the antibacterial efficacy using the following procedure:

The suspension test in this example is according to the common test protocol of EN1276.

The bacterial cultures as used have a bacterial count of having 10 ⁸ bacteria per ml.

In this test 8ml of formulation was used together with 1ml of bacterial culture and 1ml of BSA solution. The BSA solution is at a concentration of 0.03% to mimic a “clean” surface condition.

Therefore, after mixing 1 ml of culture with 8 ml of formulation and 1 ml of BSA solution the bacterial count is diluted 10 times, thus resulting in a bacterial count at the start of the experiment of 10 ⁷ bacteria per ml. The formulation and bacteria are in contact for appropriate time points (60 min, as specified in the examples below) and then neutralized (to quench the efficacy of the actives and stop its action against bacteria). With respect to a water control, the bacterial log reduction through formulations is be calculated and marked in the respective tables in the examples below. Evaluation of antimicrobial efficacy is done as such or after dilutions as specified in the data set. The examples are carried out at room temperature of 23 °C.

The efficacy against the various microorganisms is summarised in Table - 3 below:

Table -3:

In the table above the microorganisms used were:

EC: Escherichia coli ATCC 10536

EH: Enterococcus hirae ATCC 10541

PA: Pseudomonas aeruginosa ATCC 15442

SA: Escherichia coli AT CC 10536

The data in the Table -3 above indicates that there is no compromise on the hygiene benefit on using compositions as per the invention (Examples 1 & 2) as compared to a composition comprising SLS which is known to be a good surfactant for antimicrobial activity. (Example - A)

Examples B, 3: Effect of using a traditional solid peroxide sodium percarbonate as compared to using a solid peroxide as per the invention, peroxydone.

Compositions as shown in Table -4 were prepared as a tablet.

Table -4

The compositions were tested for dissolution and foam properties like dissolution time, foam height, rate of effervescence, foam quality and foam stability using the same procedure as for table -1 :

The data is summarized in Table - 5 below:

Table - 5: The data in T able - 5 above indicates that composition as per the invention (Example - 5) delivers faster dissolution and better rate of effervescence as compared to composition outside the invention (Example - B), thus proving the superiority of peroxydone over sodium percarbonate.

Examples C, 4: Difference between sodium percarbonate and peroxydone in a different surfactant system .

Compositions as shown in Table -6 were prepared as a tablet. Table -6

The compositions were tested for dissolution and foam properties like dissolution time, foam height, rate of effervescence, foam quality and foam stability using the same procedure as for table -1 :

The data is summarized in Table - 7 below:

Table - 7:

The data in Table -7 above indicates that composition as per the invention (Example -4) delivers faster dissolution and better foam height as compared to composition outside the invention (Example - C), thus proving the superiority of peroxydone over sodium percarbonate, in another surfactant system.