SILYL-CONTAINING NAIL ENAMEL

Abstract: Nail enamel compositions are disclosed which comprises a copolymer of (1) at least one siloxanylalkyl ester monomer of the formula: wherein X is OCH₃, OCH₂CH₃ or OCH₂CH₂CH₃; R₁ is either hydrogen or methyl; and n is an integer from 3 to 18; (2) at least one methacrylate monomer of the formula: wherein R₂ represents a linear or branched alkyl radical having up to 18 carbon atoms, or the radical wherein R₃ and R₄ represent an alkyl or hydroxyalkyl group having from 1 to 4 carbon atoms, and (3) at least one acrylate monomer of the formula: CH₂ =CH-COOR₅ (III) wherein R₅ represents a linear or branched alkyl radical having up to 18 carbon atoms, or an aralkyl having from 7 to 16 carbon atoms or a heteralkyl group.

Description: The present invention relates to a new nail enamel. More particularly, it relates to nail enamels containing a siloxyanylalkyl ester and which have good stability over time, a good gloss and excellent adhesion to the nail. Among the characteristics which nail enamels must possess include that they are not irritating towards the skin and the nails, that they give a film having satisfactory characteristics, that they are convenient to apply, that they are stable on storage, and that it is to say have a good homogeneity and a good stability with time. These characteristics of the film are essentially the production of a uniform thickness and a good gloss, which implies a smooth application surface, excellent adhesion to the nail and a satisfactory flexibility in order to prevent the enamel from breaking or crumbling. Nail enamels are film-forming lacquers which generally are air-dried at room temperature. Nail enamel lacquers have generally comprised (1) a film former, (2) a resin, (3) a plasticizer, (4) a solvent and (5) a colorant. Conventional nail enamels have included nitrocellulose as the film-forming constituent. Other conventional film-formers have included cellulose acetate butyrate, for example. The resin ingredient of a nail enamel is so chosen as to modify the characteristics of the film-former employed to impart sufficient hardness, resistance to chipping, and adhesive characteristics of the dried film. Resins known to be useful include synthetic resins such as arylsulfonamide-formaldehyde resins (e.g. toluene sulfonamide-formaldehyde resin), and various polyester and alkyd resins and naturally occurring resins such as damar. In some instances the same material may impart both the film-forming and resin hardening characteristics to nail enamel, e.g., poly­ styrene. The plasticizer portion is chosen with a variety of factors being considered. The plasticizer chosen depends not only upon the composition of the film-former but upon the effect desired of the indi­ vidual plasticizer on viscosity of the enamel, drying rates and the like in order to improve the adhesion and flexibility of the film. The solvents used in nail enamel compositions are employed as the volatile portion of the lacquer. The solvent systems generally include (a) one or more active (conventional) solvents, (b) couplers (which act in effect as solvents) and (c) diluents. The colorants incorporated in nail enamels impart the desired cosmetically acceptable shades and serve to opacify the dried films. Accordingly, it is the general object of this invention to provide a nail enamel having good film-­ forming and adhesion characteristics. Another object of the invention is to provide a nail enamel having a new film-forming constituent. It is yet another object of this invention to pro­ vide a silyl methacrylate ester copolymer as the film-forming constituent of a nail enamel composition. Still another object of this invention is to provide a low cost and easily handled nail enamel. Other objects, features and advantages will be apparent from the description which follows. In accordance with the present invention it has been found that it is possible to provide a satisfactory film-former for a nail enamel composition which dispenses with conventional film-forming agents without producing a deterioration in the properties of the film obtained by forming copolymers containing from 1 to 30% of a certain silyl methacrylate ester monomer, from 1 to 90% of certain methacrylate monomers, and 1 to 90% of certain acrylate monomers. Typical nail enamel compositions may have solids contents varying from about 20 to 35% and more, usually, from about 24 to 30%. The formulations of the prior art generally contain the following: film-former 8 to 16% resin 2 to 10% plasticizer 0.2 to 10% colorant .001 to 5% solvent balance The percentages given herein are (unless otherwise indicated) by weight. The copolymers used in the nail enamels according to the invention thus make it possible to partially or totally replace the film-forming and resin components of a nail enamel formulation. This itself represents an advantage by virtue of a lower cost and of a reduction in the risks involved in handling film-­ forming component and formaldehyde-based resin com­ ponent. The present invention provides an anhydrous nail enamel which is characterised in that it contains a solvent system and a film former comprising a copolymer resulting from the copolymerisation of: (1) the siloxanylalkyl ester monomer of the formula: wherein each X is OCH₃, OCH₂CH₃, OCH₂CH₂CH₃ or a phenyl group; R₁ is selected from the group consisting of methyl and hydrogen; and n is an integer from three to eighteen: (2) at least one methacrylate of the formula: in which R₂ represents a linear or branched alkyl radical having from 1 to 18 carbon atoms, or the radical wherein R₃ and R₄ represent an alkyl or hydroxyalkyl group having from 1 to 4 carbon atoms; and (3) at least one acrylate of the formula: CH₂=CHCOOR₅ (III) in which R₅ represents a linear or branched alkyl radical having from 1 to 18 carbon atoms or aralkyl having from 7 to 16 carbon atoms, or heteroalkyl group having from 1 to 18 carbon atoms wherein the carbon chain is interrupted by an O, S, or N. These copolymers comprise by weight of the copolymer: (1) at least one siloxanylakyl ester monomer of formula I, 1% to 30%, preferably 5% to 30% and more prefer­ ably 8% to 20%; (2) at least one methacrylate monomer of formula II, 1% to 90%, preferably 5% to 85%; and (3) at least one acrylate monomer of formula III, 1% to 90%, preferably 5% to 85%. These copolymers are usually terpolymers but can also be tetrapolymers, pentapolymers or higher polymers insofar as more than one of the monomers from each of the three groups mentioned above is used. Representative siloxyanylalkyl ester monomers of formula I which may be employed include trimethylsilo­ xanylmethyl methacrylate, trimethylsiloxanylethyl acrylate, propyl trialkoxy silyl methacrylate ester triphenyl siloxanylmethyl acrylate. Representative methacrylate monomers of formula II which may be employed in the practice of the invention include: methyl methacrylate ethyl methacrylate propyl methacrylate isopropyl methacrylate butyl methacrylate amyl methacrylate hexyl methacrylate heptyl methacrylate octyl methacrylate 2-ethylhexyl methacrylate nonyl methacrylate decyl methacrylate undecyl methacrylate dodecyl methacrylate lauryl methacrylate cetyl methacrylate octadecyl methacrylate oleyl methacrylate 2-N,N-dimethylamino-ethyl methacrylate Representative acrylate monomers of formula III which may be employed in the practice of this inven­ tion include: methyl acrylate ethyl acrylate butyl acrylate 2-ethyl hexyl acrylate dodecyl acrylate octadecyl acrylate In another embodiment of the invention, the cop­ olymers can also result from the copolymerization of other monomers in addition to those defined above, such as N-vinylpyrrolidone or acrylamides or methacrylamides of the formula: in which R₈ represents H or - CH₃ and R₉ represents H, -CH₂OH According to this embodiment, the percentage by weight of these additional monomers is suitably 1 to 20% by weight and preferably 2 to 15% by weight of the copolymer. Finally, the following may be mentioned amongst the additional monomers corresponding to formula (IV): acrylamide methacrylamide, N-tert.-butylacrylamide, N-­ hydroxymethylacrylamide , N-[(N'-pyrrolidone-2)-­ methyl]acrylamide and n-hydroxymethylacrylamide. The copolymers which can be used in the nail enamel compositions according to the invention can be obtained by various conventional polymerization pro­ cesses, such as suspension polymerization, bulk poly­ merization, emulsion polymerization or solution polymerization. As the nail enamels according to the invention are to be anhydrous, the polymerization is in consequence preferably carried out in solution in an organic solvent, such as ethyl acetate, butyl acetate, acetone, or preferably ethanol. Best results are obtained if the siloxanyl ester content of the comonomer is up to 35% by weight and correspondingly less, e.g., 10-15% with esters of higher silicon content. If one employs a branched chain acrylate ester derivative e.g., 2-ethylhexl acrylate, one preferably employs a lower siloxanyl ester comonomer, e.g., methyl siloxanylmethyl acrylate. The copolymers of the invention are prepared by contacting the mixture of comonomers with a free radical generating polymerization initiator of the type commonly used in polymerizing ethylenically unsaturated compounds. Representative free radical polymerization initiators include: acetyl peroxide lauroyl peroxide decanoyl peroxide caprylyl peroxide benzoyl peroxide tertiarybutyl peroxypivalate diisopropyl peroxycarbonate tertiarybutyl peroctoate N,N'-azobisisobutyronitrile Conventional polymerization techniques can be employed to produce the novel copolymers. The comonomer mixture containing between about 0.05 - 2% by weight of the free radical initiator is heated to a temperature between 30°C. - 100°C., preferably below 70°C., to initiate and complete the polymerization. The temperature is preferably maintained below 70°C. in order to minimize the formation of bubbles in the copolymer. Instead of employing the bulk polymerization techniques described above, one can employ solution, emulsion or suspension polymerization to prepare the novel copolymers, using techniques conventionally used in the preparation of polymers from ethylenically unsaturated monomers. The copolymers used in the invention generally have a molecular weight of 2,000 to 200,000 and prefer­ ably 10,00 to 100,000, measured by osmometry. Whether colored or colorless, the nail enamel compositions according to the present invention generally contain from 3 to 35% by weight of a copolymer as defined above, the remainder comprising the solvent system of the enamel, that is to say the customary solvents and/or conventional diluents for this type of composition. As has been stated, the nail enamels according to the invention are anhydrous, so that the solvent system is produced from organic solvents or mixtures thereof. This makes it possible to obtain relatively short drying times. The following are included among the solvents useful in the present invention: acetone, ethyl acetate, butyl acetate, 2-methoxyethyl acetate, methyl ethyl ketone, methyl isobutyl ketone and methyl acetate. The solvent system may also include a diluent, preferably an aromatic orangic solvent, such as toluene or xylene, in a proportion which is generally from 10 to 30%, relative to the total weight of the nail enamel composition. The enamels can also contain other volatile solvents, such as ethanol, n-butanol n-propanol, iso­ propanol or mixtures thereof. The nail enamels may also contain from, say, 0.2 to 10% by weight of at least one plasticizer to improve the adhesion and the flexibility of the film-­ forming copolymer. The following may be mentioned among the plasticizers: benzyl benzoate, tributyl phosphate, butyl acetylricinoleate, glyceryl acetylricinoleate, dibutyl phthalate, butyl glycolate, dioctyl phthalate, butyl stearate, tributoxyethyl phosphate, triphenyl phosphate, triethyl citrate, tributyl citrate, tributyl acetylcitrate, 2-triethylhexyl acetylcitrate, dibutyl tartrate, dimethoxyethyl phthalate, diisobutyl phthalate, diamyl phthalate, camphor and various mixtures thereof. Although, with the nail enamels according to the invention, it is possible to dispense with using nitrocellulose and/or a resin of the arylsulfonamide/­ formaldehyde type, it is possible to introduce them into the formulations, albeit in a substantially lower proportion than that which is commonly employed. The nitrocelluloses are typically the "RS" or "SS" type, in particular 1/4 second RS type nitrocellulose, 1/2 second RS type nitrocellulose and RS 1/4 second type nitrocellulose. The resins of the arylsulfonamide/formaldehyde type are those known by the tradenames "Santolite MHP" and "Santolite MS 30%, the former being the harder, the latter leaning to the formation of films of greater flexibility. If the nail enamel according to the present invention is to contain a colorant at least one organic or inorganic colorant may be used. The following may be mentioned among the organic colorants: D and C Red Nos. 10, 11, 12, and 13, D and C Red No. 7, D and C Red Nos. 5 and 6, D and C Red No. 34 and lakes, such as the lake D and C YELLOW No. 5 and the lake D and C Red inorganic colorants: titanium dioxide, bismuth oxychloride, brown iron oxide, red iron oxide, and also guanine. These colorants are preferably present in the nail enamel in an amount of 0.1 to 8% by weight, relative to the total weight of the nail enamel compo­ sition. The nail enamel compositions according to the invention can also contain other ingredients, such as products which make it possible to avoid sedimentation, and especially clays of the montmorillonite type such as bentonite, and/or a swelling agent, such as ortho­ phosphoric acid. The following examples further illustrate the present invention and the preparation of the copo­ lymers used in the nail enamel compositions according to the invention. EXAMPLE I This example illustrates the synthesis of a representative copolymer made from a representative siloxanylakyl ester monomer of formula I and a meth­ acrylic ester of formula II. A mixture of 40 grams of a propyl trialkoxy silyl methacrylate monomer, 40 grams 2-N,N-dimethylam­ inoethyl methacrylate, 20 grams of ethyl acrylate and 0.004 ml. of tert-butyl peroxypivalate per ml of monomer mixture are placed in a suitable flask fitted with a mechanical stirrer, a condenser and a nitrogen inlet tube. After stirring, the reaction mixture is heated under reflux for 16 hours. After cooling, the solution is diluted with 100 g of ethyl acetate and the polymer is then precipitated by adding 7 liters of petroleum ether. After drying, the expected polymer is obtained. EXAMPLE 2 A colorless nail enamel according to the invention may be prepared by mixing the following ingredients: Polymer of Example 1 - 25 g Dibutyl phthalate - 3 g Camphor - 2 g Ethyl acetate - 30 g Butyl acetate - 40 g On applying this nail enamel composition to the nails with a brush, a uniform layer is obtained which, after drying, has good adhesion and an excellent gloss. EXAMPLE 3 A colored nail enamel is prepared according to the invention by mixing the following ingredients: Polymer of Example 1 - 25 g Butyl phthalate - 2 g Ethyl acetate - 20 g Toluene - 10 g Bentonite 27 - 1.5 g Phosphoric acid - 0.02 Titanium oxide - 0.75 Brown iron oxide - 0.25 g D and C RED 7-calcium lake - 0.5 g D and C. RED 34 - 0.3 g D and C YELLOW 5-aluminum lake - 0.7 g Butyl acetate q.s.p. -100 g

Claims: 1. A nail enamel composition comprising a film-­ former and an organic solvent system, said film-former comprising a copolymer resulting from the polymerization of: (1) 1 to 30% by weight of at least one silox­ anylkyl ester monomer of the formula: wherein each X is OCH₃, OCH₂CH₃, OCH₂CH₂CH₃ or a phenyl group; R₁ is methyl or hydrogen; and n is an integer from 3 to 18; (2) 1 to 90% by weight of at least one methacrylate monomer of the formula: wherein R₂ represents a linear or branched alkyl radical having up to 18 carbon atoms, or the radical wherein R₃ and R₄ represent an alkyl or hydroxy­ alkyl group having from 1 to 4 carbon atoms; and (3) I - 90% by weight of at least one acrylate monomer of the formula: CH₂=CH-COOR₅ (III) wherein R₅ represents a linear or branched alkyl radical having up to 18 carbon atoms, or an aralkyl radical having from 7 to 16 carbon atoms, or an heteroalkyl group having from 1 to 18 carbon atoms wherein the carbon chain is interrupted by an 0, N or S atom. 2. The nail enamel according to claim 1 in which said copolymer comprises: (1) 5 to 20% by weight of at least one siloxanyl­ alkyl ester monomer of formula (I), (2) 5 to 85% by weight of at least one methacrylate monomer of formula (II), and (3) 5 to 85% by weight of at least one acrylate monomer of formula (III). 3. The nail enamel according to claim 1 or 2 in which said copolymer also contains at least one other monomer which is N-vinylpyrrolidone or an acrylamide or methacrylamide of the formula: in which R₈ represents H or - CH₃ and R₉ represents H, -CH₂OH, in an amount of 1 to 20% by weight relative to the total weight of the monomers. 4. The nail enamel according to claim 3 in which the said other monomer comprises from 2 to 15% by weight relative to the total weight of the monomers. 5. The nail enamel according to claim 3 or 4 in which the acrylamide or methacrylamide of formula (IV) is acrylamide, methacrylamide, N-tert.-butylacrylamide, N-hydroxyethylmethacrylamide , N-[(N'-pyrrolidone-2)-­ methyl]acrylamide or n-hydroxymethylacrylamide. 6. The nail enamel according to any of claims 1to5 unsaturated monomer of formula (I) is a propyl trialkoxy silyl methacrylate ester. 7. The nail enamel according to any of claims 1to6 in which the methacrylate monomer of formula (II) is methyl, ethyl, butyl, tert-butyl, hexyl, dodecyl or octadecyl methacrylates or 2-N,N-dimethylamino-ethyl methacrylate. 8. The nail enamel according to claim I in which the acrylate of formula (III) is of methyl,ethyl,butyl, 2-ethyl hexyl, dodecyl or octadecyl acrylate. 9. The nail enamel according to any of claims 1to8 in which the copolymer is quaternized with a quaternizing agent selected from dimethyl sulfate or ethyl bromide 10. The nail enamel composition according to any of claims 1to9 where the organic solvent system is acetone, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl acetate or mixtures thereof. 11. The nail enamel composition according to any of claims 1to10 further comprising a plasticizer. 12. The nail enamel composition according to claim 11 wherein the plasticizer is benzyl benzoate or tributyl phosphate. 13. The nail enamel composition according to any claims 1 to 12 further comprising a colorant.

Inventors: SCHNETZINGER, RICHARD W.
Applicants: REVLON, INC.
Application year: 1986
Main classification: A61K7
IPC codes: A61Q3, C08F220, A61K8, C08F30