WO2005123969A1

WO2005123969A1 - Polish composition for leather or synthetic leather

Info

Publication number: WO2005123969A1
Application number: PCT/GB2005/002383
Authority: WO
Inventors: Jason Radley; Chris Wigley
Original assignee: Reckitt Benckiser (Uk) Limited
Priority date: 2004-06-21
Filing date: 2005-06-17
Publication date: 2005-12-29
Also published as: PL1759023T3; ES2341263T3; MXPA06015074A; BRPI0512339A; GB0413831D0; DE602005019565D1; BRPI0512339B1; EP1759023A1; EP1759023B1; ATE458836T1; ZA200609719B

Abstract

A polish composition for treating a leather and/or synthetic leather article, said composition comprising water, at least one way, at least one film-forming polymer, and a layered silicate incorporating an inorganic peptiser.

Description

Improvements in or relating to a Composition

This invention relates to a polish composition suitable for treating leather and/or synthetic leather articles. In particular, although not exclusively, this invention relates to self-shining polish compositions.

Polish compositions are often used to impart a shine to leather and synthetic leather articles, such as items of footwear. Conventional polish compositions are typically formed of wax and organic solvents. Such polishes dry to form a dull finish on the treated article. Subsequent. buffing is required to provide the article with a shiny finish.

Self-shining polishes in liquid form have been developed to allow a shine to be achieved without any buffing. More recently, gel or cream self-shining compositions have also been developed. Such compositions are generally based on aqueous emulsions of wax and acrylic polymers. When applied to an article, the compositions dry to form a glossy finish. Buffing is not generally required to provide the treated article with the desired shine.

We have found that known self-shine polish compositions tend to suffer from storage problems. For example, when stored for prolonged periods, liquid may separate from the known compositions. The separation of liquid from the bulk of the composition is known as syneresis. According to the present invention, there is provided a polish composition for treating leather and/or synthetic leather articles, said composition comprising water, at least one wax, at least one film-forming polymer, and a layered silicate incorporating an inorganic peptiser.

By including a layered silicate in the polish composition, the storage problems of the polish composition can advantageously be reduced. In particular, the use of the layered silicate may reduce the likelihood of liquid separating from the polish composition even after prolonged periods of storage. The layered silicate, therefore, may be used in the polish composition to reduce or prevent syneresis. The layered silicate may also help to ensure that the rheological properties of the polish composition are maintained, for example, to ensure ease of application. Preferably, the composition of the present invention is storage stable for at least 4 weeks, more preferably, at least 8 weeks, and most preferably, at least 12 weeks.

Preferably, the layered silicate is a synthetic layered silicate. The layered silicate may be a metal silicate, such as silicate of an alkali metal and/or alkali earth metal. Suitable alkali metal silicates include silicates of lithium, sodium and potassium. Suitable alkali earth metal silicates include silicates of magnesium and calcium. Preferably, the metal silicate is a silicate of at least one alkali metal and at least one alkali earth metal. In one embodiment, sodium lithium magnesium silicate is employed. Preferably, the layered silicate comprises less than 2 weight %, more preferably, less than 1 weight %, even more preferably, less than 0.5 weight %, and most preferably, less than 0.1 weight % of crystalline silica. In one embodiment, the layered silicate is substantially free of crystalline silica.

The layered silicate may also have a low transition metal content. For example, the layered silicate may have a transition metal content of less than 2 weight %, more preferably less than 1 weight %, yet more preferably less than 0.5 weight %, for example, less than 0.1 weight %. In one embodiment, the layered silicate is substantially free of transition metal.

The layered silicate incorporates an inorganic peptiser. Preferably, the inorganic peptiser is a phosphate. Any suitable phosphate peptiser may be employed. However, metal phosphates, such as alkali metal and/or alkali earth metal phosphates are preferred. Suitable alkali metal phosphates include phosphates of lithium, sodium and potassium. Suitable alkali earth metal phosphates include phosphates of magnesium and calcium.

Preferably, the phosphate is a polyphosphate, such as a pyrophosphate . In a preferred embodiment, sodium tera pyrosphosphate is employed. An example of a suitable layered silicate is Laptonite ® RDS. The layered silicate is preferably provided in finely divided form.

The layered silicate may be present in an amount of 0.01 to 5 weight % of the overall polish composition.

Preferably, the layered silicate is present in an amount of 0.05 to 4 weight %, more preferably, 0.1 to 3 weight %, for example, 0.2 to 2 weight %. In a preferred embodiment, 0.4 to 1 weight %, for example, 0.5 to 0.7 weight % of layered silicate is employed.

The polish composition comprises at least one wax. Mixtures of one or more waxes may also be employed. Suitable waxes include insect waxes, such as beeswax; vegetable waxes, such as carnauba wax and candelilla wax; mineral ester waxes and acid waxes. Preferably, mineral ester waxes are employed. Suitable mineral ester waxes include montanic wax (e.g. montanic wax ester) . Synthetic waxes, such as polyethylene wax (e.g. oxidised) and polyol ether/ester wax may also be employed. In a preferred embodiment, the polish composition comprises montanic wax ester and a synthetic wax, such as oxidised polyethylene wax. Where a montanic wax ester is employed, it may be a refined montanic wax ester.

The wax or wax mixture employed in the polish composition of the present invention preferably has an acid value of 5 to 50, preferably, 10 to 30. The wax or wax mixture employed in the polish composition preferably has an average molecular weight of 500 to 5000, preferably, 1000 to 4000, for example, 2000 to 3000.

The amount of wax in the polish composition may be 1 to 20 weight %, preferably, 2 to 15 weight %, more preferably, 5 to 10 weight %. In a preferred embodiment, the polish composition comprises 1 to 6 (e.g. 2 to 4) weight % oxidised polyethylene wax and 2 to 10 (e.g. 3 to 8) weight % montanic wax ester.

The polish composition includes a film-forming polymer. One or more film-forming polymers may be included in the polish composition. Suitable film-forming polymers include, acrylic polymers (e.g. modified acrylic polymers), polyurethane and silicones.

Suitable acrylic polymers include polymers of monomers selected from at least one of acrylic acid, methacrylic acid and esters thereof . Homopolymers and copolymers may be employed. Suitable copolymers include styrene/acrylic copolymers, such as copolymers of methacrylic acid ester and styrene acrylic copolymer. In one embodiment, a mixture of methacrylic acid ester copolymer and styrene acrylic copolymer is employed.

The film-forming polymer may be present in the polish composition in an amount of 1 to 20 weight %, preferably, 8 to 18 weight %, for example, 4 to 12 weight % of the total composition. In one embodiment, the polish composition comprises 2 to 4 weight % of a styrene acrylic copolymer and 2 to 4 weight % of a methacrylic acid ester copolymer. The polish composition of the present invention is preferably in the form of a gel or cream. Thus, the polish composition of the present invention preferably has a viscosity of 50 to 100,000 centipoise.

The polish composition preferably includes an alkali soluble resin. Preferably, maleinic acid resin is employed as the alkali soluble resin. A suitable maleinic resin is sold under the trademark ALRESAT ®. The alkali soluble resin may improve shine and may help to gel the composition.

The alkali soluble resin may be present in an amount of 0.01 to 10 weight %, preferably, 0.5 to 8 weight %, for example, 1 to 5 weight %.

The polish composition of the present invention is preferably in the form of an emulsion, for example, an oil- in-water emulsion. Water may be present in the polish composition in an amount of 5 to 90 weight %, preferably, 10 to 75 weight %, more preferably, 20 to 60 weight %, for example, 40 to 55 weight %. The polish composition preferably comprises at least one alcohol, such as a Ci to Cι₀ alcohol. The alcohol may help to gel the polish composition. Examples of suitable alcohols include methanol , ethanol, propanol, butanol, pentanol , hexanol , heptanol , octanol , nonanol and decanol . Preferably, a C₂ to C₆ alcohol, such as ethanol, propanol, butanol, pentanol and/or hexanol, is employed. In a preferred embodiment, a C₃ or C alcohol, such as propanol or butanol is employed. Isopropyl alcohol is preferred. Alcohols may be employed in an amount of 1 to 30 weight %, preferably, 5 to 20 weight %, more preferably, 8 to 15 weight %. In a preferred embodiment, the polish composition contains 8 to 15 weight % isopropyl alcohol.

Other organic solvents may also be present in the polish composition. For example, the polish composition may include one or more hydrocarbon solvents. Without wishing to be bound by any theory, the hydrocarbon solvent may help to stabilise the composition, particularly, when the composition is in the form of a gel . When hydrocarbon solvents are employed, the hydrocarbon solvent is preferably treated to remove any aromatic components. A suitable hydrocarbon solvent is sold under the trademark EXXSOL ® D40. When a hydrocarbon solvent is used, it is preferably used in an amount of 1 to 5 weight % .

The polish composition of the present invention may optionally include a surfactant or emulsifier. Nonionic surfactants, such as fatty alcohol ethoxylates, are preferred. Fatty alcohol ethoxylates derived from the reaction between a C₁₂ to C_i5 alcohol and ethylene oxide are particularly preferred. Preferably, each mole of alcohol reacts with 8 to 15 moles of ethylene oxide. Examples of suitable surfactants and emulsifiers are sold under the trademarks Emulsifier 4106 (Clariant) and Genopol X060 (ex Clariant) . Emulsifiers or surfactants may be employed in an amount of 0.1 to 10 weight %, preferably, 1 to 10 weight %, for example, 2 to 5 weight % of the total composition. The polish composition may optionally include dyes. Suitable dyes include Acid black 2. In one embodiment, carbon black dispersion is included in the polish composition.

Dye(s) may be present in an amount of 0.01 to 10 weight %, for example, 0.1 to 5 weight %. Other optional components such as perfumes and preservatives may also be included in the polish composition.

The composition may also include a stabilising additive such as 2-amino 2 -methyl propan-1-ol. Such additives are believed to promote emulsion stability.

In one embodiment, the polish composition of the present invention is an aqueous emulsion comprising: water (e.g. in an amount of 20 to 60 weight %) , wax (e.g. in an amount of 5 to 10 weight) , film-forming polymer (e.g. in an amount of 8 to 20 weight %) , alkali soluble resin (e.g. in an amount of 0.5 to 8 weight %) , alcohol (e.g. in an amount of 5 to 20 weight %) , layered silicate incorporating an inorganic polyphosphate (e.g. in an amount of 0.01 to 5 weight %) , and, optionally, hydrocarbon solvent and/or surfactant . In the embodiment above, the wax is preferably a mixture of montanic ester wax and oxidised polyethylene wax, the film-forming polymer preferably comprises at least one acrylic polymer, the alkali soluble resin is preferably maleinic acid resin, and the alcohol is preferably isopropyl alcohol. More preferably, the film-forming polymer comprises a copolymer of methacrylic acid esters and a styrene acrylic copolymer. The polish composition of the present invention is suitable for treating leather and synthetic leather articles. Suitable articles include items of footwear, such as shoes, boots and sandals, as well as bags, belts, gloves, saddles and furniture.

Preferably, the polish composition of the present invention provides a shiny or glossy finish to the article under treatment. The polish composition may also help to increase the leather's (or synthetic leather's) resistance to weathering, scuffing and scratching.

The polish composition of the present invention may be applied to a leather or synthetic leather article and left to dry. Once dry, the composition leaves a shiny film on the surface of the article. The treated article may be buffed to increase the shine but, in a preferred embodiment, buffing is not necessary to provide the treated article with a shine. Thus, in this preferred embodiment, the polish composition is self-shining. The layered silicate is believed to be especially useful in a self-shining polish composition, as the silicate is believed to provide the composition with a shear-thinning rheology that assists in the formation of a shiny film on the article upon application.

The polish composition of the present invention may be dispensed using a sponge applicator. The polish composition may be contained in a tube or, preferably, a jar.

The polish composition of the present invention may be prepared by mixing the individual components of the composition together, for example, to form an emulsion.

In one embodiment, the film-forming polymer and layered silicate are added to an aqueous emulsion of the wax(es), preferably, with vigorous stirring. Preferably, the layered silicate (e.g. sodium lithium magnesium silicate modified with tera sodium pyrophosphate) is added to the wax emulsion in the form of a pre-formed aqueous solution.

In addition to the film-forming polymer and layered silicate, components such as resins, dye(s), surfactants, emulsifiers and solvents may also be added to the wax emulsion, preferably, with continuous stirring. When employed, the surfactant (e.g. fatty acid polyglycol ether) and solvent (e.g. hydrocarbon solvent) may be added as a pre-formed mixture. In a preferred embodiment, an alcohol solvent, such as iso-propyl alcohol is added to the resulting mixture in a steady stream, so as to aid gel formation. The wax emulsion may be formed in a preliminary step, for example, by melting the wax(es) at an elevated temperature of, for example, 80 to 150°C, preferably, 100 to 130°C, more preferably, 120 to 125°C. In a separate container, water may heated to a temperature of, for example, 80 to 100°C, preferably, 90 to 95°C. The molten wax may then be added to the water and the resulting mixture stirred to form an emulsion (e.g. oil-in-water emulsion). Optionally, an emulsifier (e.g. fatty acid polyglycol ethers) and/or a stabilizing additive (e.g. 2-amino-2-methyl prompan-1-ol) may be added to the molten wax, for example, before the molten wax is mixed with water. Once the molten wax has been mixed with water, the resulting mixture may be cooled, for example, by crash cooling to a temperature of, for example, 10 to 50°C, for example, 30 to 40°C.

Example

The self-shining composition of Table 1 was prepared by first heating waxes (ii and iii) with component (iv) at a temperature of 120 to 125°C to form a molten wax mixture. Component (v) was added to the mixture. The molten wax mixture was then slowly added to hot water (90 to 95°C) with vigorous stirring. The resulting mixture was then crash cooled to 40°C to form a wax emulsion. Approximately 75% of the 46.58 w/w% water in the composition is employed to form the wax emulsion. The remaining water is mixed with component (xi) to form a dispersion (see below) .

Components (xiv) , (xiii) , (x) , (ix) and (viii) were then added to the wax emulsion with vigorous stirring. Thereafter, a mixture of component (xi) and water was added and the resulting mixture stirred for a further 15 minutes. A premix of components (vi) and (vii) was then added. The resulting mixture was stirred for a further 20 minutes before component (xii) was added in a steady stream. Creamy gel formation took place within 1 hour of the addition of component (xii) .

Comparative Example The procedure described with reference to the Example above was repeated to prepare the self-shining composition of Table 2. Component (xi) , however, was omitted from the composition of the Comparative Example. Thus, all of the 49.16 w/w% water in this Comparative Example is used to form the wax emulsion.

The compositions of the Example and the Comparative Example were stored in sealed glass jars for one month. The composition according to the Example was storage stable. In contrast, composition of the Comparative Example exhibited syneresis.

Table 1

Table 2

Claims

1. A polish composition for treating a leather and/or synthetic leather article, said composition comprising water, at least one wax, at least one film-forming polymer, and a layered silicate incorporating an inorganic peptiser.

2. A composition as claimed in claim 1, wherein the inorganic peptiser is an inorganic polyphosphate.

3. A composition as claimed in claim 1 or 2 , wherein the wax comprises montanic wax ester and oxidised polyethylene wa .

4. A composition as claimed in any one of the preceding claims, wherein the film-forming polymer is selected from at least one of silicone, polyurethane and acrylic polymer.

5. A composition as claimed in claim 4, wherein the film- forming polymer comprises a mixture of styrene acrylic copolymer and a copolymer of methacrylic acid ester.

6. A composition as claimed in any one of the preceding claims, which further comprises an alkali soluble resin.

7. A composition as claimed in claim 6, wherein the alkali soluble resin is a maleinic acid resin.

8. A composition as claimed in any one of the preceding claims, which is in the form of an oil-in-water emulsion.

9. A composition as claimed in any one of the preceding claims, which comprises 1 to 20 weight % of said wax, 1 to 20 weight % of said at least one film- forming polymer, 0.01 to 5 weight % of said layered silicate.

10. A composition as claimed in any one of the preceding claims, which further comprises an alcohol.

11. A composition as claimed in claim 10, wherein the alcohol is isopropyl alcohol.

12. A composition as claimed in any one of the preceding claims, which is a self-shining polish composition.

13. A method of preparing a composition as claimed in any one of claims 1 to 12, said method comprising: forming an aqueous emulsion of said wax, said film- forming polymer, and said synthetic layered silicate.

14. A method as claimed in claim 15, which further comprises the addition of an alcohol.

15. A method of treating a leather and/or synthetic leather article, which comprises applying a composition as claimed in any one of claims 1 to 12 to a leather and/or synthetic leather article.

16. A method as claimed in claim 15, wherein said composition is allowed to dry to form a shiny finish without buffing.

17. Use of a synthetic layered silicate incorporating an inorganic peptiser in a polish composition to reduce or prevent syneresis of the polish composition.

18. Use as claimed in claim 17, wherein said polish composition comprises water, at least one wax and at least one film- forming polymer.

19. Use as claimed in claim 18, wherein said polish composition is a self-shining polish composition.