FR2972633A1 - PHOTORETICULABLE NAIL VARNISH EXEMPT FROM UNSATURATED MONOMERS - Google Patents

Abstract

The invention relates to a photocurable cosmetic composition, free from reactive monomers with a molecular mass of less than 400 g / mol comprising one or more ethylenic double bonds: at least one polymer containing ethylenic double bonds, the average number of ethylenic double bonds per molecule of polymer being greater than 1, said at least one polymer comprising at least one polyether polymer containing groups (meth) acrylate modified by reaction with an amino group, and - at least one radical photoinitiator. The invention also relates to a process for the cosmetic coating of nails or false nails using such a composition.

Description

The present invention relates to cosmetic compositions, especially photocurable nail polishes, free from monomers, and a method of depositing a crosslinked coating in situ using these compositions.

The nail polish compositions can be used as a base for varnish, as a nail makeup product, as a finishing composition, also called a top coat in English terminology, to be applied to the nail makeup product or else as a product of cosmetic care of nails. These compositions can be applied to both human nails and false nails.

Nail varnishes are known from liquid cosmetic compositions which, after deposition on the nail and under the action of actinic radiation, undergo polymerization and / or in situ crosslinking reactions resulting in polystyrene networks. more often crosslinked. Such photopolymerizable and / or photocurable compositions are described, for example, in patents CA 1 306 954, US 5 456 905, US Pat. No. 7,375,144 and FR 2 823 105.

These compositions generally contain one or more polymers and / or prepolymers comprising polymerizable ethylenic double bonds, one or more reactive monomers with double bond (s), at least one photoinitiator, optionally one or more agents that inhibit the premature polymerization of the components. or photosensitizing agents for modifying the absorption spectrum of the photoinitiator system.

The main disadvantage of these compositions lies in the toxicity of the unsaturated monomers used. Indeed, these highly reactive, low molecular weight molecules readily diffuse into underlying and adjacent substrates where they react with biological molecules.

The applicant has sought to solve this problem of toxicity of photocurable cosmetic compositions of the prior art by developing photocurable cosmetic compositions containing, as only polymerizable or crosslinkable reactive components, macromolecular compounds, that is to say components reagents having a molecular weight sufficient to prevent their diffusion to neighboring biological substrates.

No. 7,375,144 discloses photocurable compositions free of mono-acrylate monomers capable of polymerizing under UV radiation. However, the compositions described comprise large amounts of di-acrylate compounds of low molecular weight that can diffuse into underlying and adjacent substrates, and react with biological molecules.

Patent FR 2 823 105 describes photocrosslinkable compositions free of compounds having molecular weights of less than 500 g / mol. However, the compositions described do not make it possible to obtain compositions with a viscosity suitable for being applied correctly to the nails, or do not make it possible to obtain films with sufficient rigidity or cohesion to obtain good holding properties on the nails. 'nail.

The present invention therefore relates to photocurable cosmetic compositions free of reactive monomers with double bond (s) ethylene (s), comprising: - at least one polymer having ethylenic double bonds, the average number of ethylenic double bonds per molecule of polymer being greater than 1, said at least one polymer comprising at least one polyether polymer containing groups (meth) acrylate modified by reaction with an amino group, and - at least one radical photoinitiator.

Preferably, this composition comprises at least two polymers comprising ethylenic double bonds, the average number of ethylenic double bonds per molecule of polymer being greater than 1, said at least two polymers comprising at least one polyether polymer containing modified (meth) acrylate groups. by reaction with an amino group and at least one polyether polymer with (meth) acrylate group (s). Throughout the application, a polymer polyether unsaturated (meth) acrylate group (s) by reaction with an amino group is a polymer polyether group (s) (meth) acrylate not modified by reaction with an amino group.

In particular, photocurable cosmetic compositions free of reactive monomers with double (s) ethylenic link (s) are free of monomers (meth) acrylate and monomers urethane (meth) acrylate. "Monomer (meth) acrylate" means any compound having a single function, or group, (meth) acrylate of formula H 2 C = C (R) -C (O) -OX, with R = H or CH 3 and X radical on which this (meth) acrylate function is grafted. The term "urethane (meth) acrylate monomer" means any compound comprising at least one urethane function -OC (O) -NH-, and at least one (meth) acrylate function of formula H 2 C = C (R) -C (O) -OX, with R = H or CH3 and X the radical on which this (meth) acrylate function is grafted. Preferably, said photocurable cosmetic composition is a nail varnish. The invention also relates to a process for the cosmetic coating of nails or false nails using these photocurable cosmetic compositions previously defined. In the remainder of this application, the following terms are understood to mean: (poly) ol, a monoalcohol or a polyol, preferably a diol, advantageously having from 2 to 20 carbon atoms, more preferably from 2 to 6 carbon atoms; (poly) alkoxylated (s), one or more group (s) divalent -RO-, R being a C1-C6 alkylene, preferably -RO- being (CH2-CH2-0) n or (CH2-CH2-CH2 -0) n, n being an integer greater than 1, for example between 1 and 1000; - (poly) hydroxylated (s), one or more group (s) -OH.

As indicated above, the average number of ethylenic double bonds carried by the polymer (s) forming the crosslinked polymeric network of the final cured coating must be greater than 1. Indeed, a polymerizable system consisting of molecules (monomers, oligomers or polymers) each carrying a single double bond forms, after reaction of all the double bonds, a macromolecular system with linear or branched but not crosslinked chains. Only the presence of a certain fraction of molecules bearing at least two double bonds and thereby acting as a crosslinking agent makes it possible to obtain a crosslinked polymer system. In the practice of the present invention, the average number of functions per polymer molecule is preferably greater than or equal to 2, advantageously between 2 and 6 inclusive.

As explained above, the safety of the photocurable cosmetic compositions of the present invention is due to the fact that the polymer (s) having one or more ethylenic double bonds have a molecular weight sufficient to prevent their diffusion to and within the substrates biological neighbors. By sufficient molecular weight is meant a weight average molecular weight greater than or equal to 400. In particular, the weight average molecular weight may range from 400 to 5000.

In a preferred embodiment, the polyether (s) polyether group (meth) acrylate modified by reaction with an amino group according to the invention have a weight average molecular weight greater than or equal to 400, in particular ranging from 450 to 5000, and preferably from 500 to 3000.

Photocrosslinkable Polymers A composition according to the present invention comprises polymers carrying ethylenic double bonds and having an appropriate molecular weight. More specifically, a composition according to the invention comprises at least one polyether polymer containing (meth) acrylate groups modified by reaction with an amino group. Preferably, a composition according to the invention also comprises at least one polyether polymer containing (meth) acrylate groups (not modified by reaction with an amino group). a) Polyether polymers containing (meth) acrylate groups modified by reaction with an amino group A polyether polymer containing groups (meth) acrylate modified by reaction with an amino group present in a composition according to the invention preferably comprises at least two functions (meth) acrylates, preferably from 2 to 4 (meth) acrylate functions, and more preferably from 2.5 to 3.5 (meth) acrylate functions. Such a polymer has a molecular weight of preferably between 400 g / mol and 1500 g / mol, more preferentially between 500 g / mol and 1000 g / mol. This polymer is preferably obtained by esterification with (meth) acrylic acid of some or all of the terminal hydroxyl groups derived from homopolymers or copolymers of C 1 -C 6 alkylene glycols, such as polyethylene glycol, polypropylene glycol, copolymers of ethylene oxide and of propylene oxide preferably having a weight average molecular weight of less than 10 000 g / mol, polyethoxylated or polypropoxylated glycerols, polyethoxylated or polypropoxylated trimethylolpropanes, polyethoxylated or polypropoxylated pentaerythritols, polyethoxylated or polypropoxylated trimethylolpropanes, polyethoxylated or polypropoxylated di-pentaerythritols. Such polyols are described in particular in the US Pat. No. 5,543,557. According to the invention, at least a portion, or all, of the ethylenic groups of the (or) polymeric polyether (meth) acrylate group (s) is modified by reaction with an amino group. Such polymers may advantageously meet the following formula (I '). Such polymers according to the invention preferably comprise polymers partially modified by reaction with an amino group, as described in US2009 / 0098304. These polymers can in particular be obtained by reaction between a part of the ethylenic groups of the polyether polymer containing (meth) acrylate groups as described above and a primary or secondary amine, according to the following reaction scheme (Michael addition): CH 2 + O-ALK + i ## STR5 ## wherein R 1 is CH 2 O-ALK-R 7 R x; R 1 CH 2 -O-ALK-R 7 + 0-ALK11-20 x; XR "(Formula I ') Formula (I') in which: ^ -, identical or different, represent a single or double bond; ALKI and ALK2, which may be identical or different, represent a (C 1 -C 6) alkyl group such as ethyl or propyl; (Formula I) ^ xi and x2, which may be identical or different, represent an integer greater than or equal to 1 as inclusive between 1 and 1000; R 1 and R 2, which are identical or different, represent a hydrogen atom or a group (C 1 -C 8 alkyl) such as methyl, X, which are identical or different, represent a CH 2 group when - is a double bond or X represents an amino group CH 2 NRaRb when is a simple bond with Ra representing an alkyl optionally substituted with a hydroxy, alkoxy, tertiary amine or aryl, and Rb representing a hydrogen or an alkyl optionally substituted by a hydroxy, alkoxy, tertiary amine or aryl .Ra and Rb may be bonded together to form a ring; R 'representing: i) a group of the following formula (II'): O (*) CH2 + 0 ALK3 30: x X Formula (II ') in which: - ALK3 represents a group (C1 -COalkyl such as ethyl or propyl; -x3 represents an integer greater than or equal to 1 as inclusive between 1 and 1000; -R3 represents a hydrogen atom or a group (C1-COalkyl such as methyl - X being as previously def ii) a group of the following formula (III): ## STR2 ## wherein: ALK 4 represents a (C 1 -C 6) alkyl group such as ethyl or propyl; - x4 represents an integer greater than or equal to 1 such that inclusive inclusive between 1 and 1000; - R4 represents a hydrogen atom or a (Ct-C6) alkyl group such as methyl; X being as previously defined; iii) a group of the following formula (IV '): () - CHz - O - ALKs - O - ALK6 (IV) - Formula (IV) in which: - ALK5 and ALK6, which are identical or different, represent a group (CI-C6) ) alkyl such as ethyl or propyl, X being as defined above, or iv) a group of the following formula (V '):

## STR3 ## wherein: ALK7 and ALK8, which may be identical or different, are embedded in the formula (V ') in which: ## STR1 ## represent a (C 1 -C 6) alkyl group such as ethyl or propyl; - x 7 and x 8, which may be identical or different, represent an integer greater than or equal to 1, such as between 1 and 1000 inclusive, - R 7 and R 8, identical or different, represent a hydrogen atom or a (C 1 -C 6) alkyl group such as methyl; R "'being a hydrogen atom or a (C 1 -C 6) alkyl group such as ethyl, or an alkoxy group such as methoxy, or the group of formula (VI '): OK (1 CH2 + 0 ALK9 + 90 ~~ (VI') X Formula (VI ') in which: - ALK9 represents a group ( C1-C6) alkyl such as ethyl or propyl; -x9 represents an integer greater than or equal to 1 as inclusive between 1 and 1000; 5 -R9 represents a hydrogen atom or a group (C1-C6) alkyl such as methyl; - X being as previously defined - and their mixtures; R "representing a hydrogen atom, or a (C 1 -C 6) alkyl group such as ethyl, or an alkoxy group such as methoxy, or the group of formula (VII '): O R 10 (*) - CH 2 + 0 ALK 10], pZ / X; X 10 (VII ') Formula (VII') in which: - ALK 10 represents a (C 1 -C 6) alkyl group such as ethyl or propyl; - x 10 represents a higher integer or equal to 1 as inclusive between 1 and 1000; R10 represents a hydrogen atom or a (C1-C6) alkyl group such as methyl; and mixtures thereof. It is understood in the preceding formulas that these formulas comprise at least one X group representing an amino group (as previously defined) when the polyether (meth) acrylate is modified by reaction with an amino group The reaction between the (meth) acrylate and the amine does not require a catalyst or preferably, the molar ratio between the amine and the ethylenic groups of the polyether polymer containing (meth) acry groups lates is between 0.01: 1 and 0.5: 1. Such polymers are sold for example by CYTEC under the names EBECRYL® LEO 10551: molar mass 500 g / mol, on average 2.5 acrylate functions per molecule, EBECRYL® LEO 10552: molar mass 1000 g / mol, average 3.5 acrylate functions per molecule, or else such polyether polymers modified by reaction with an amino group of suitable molar mass are marketed for example under the names CN501 and CN550 by the company Sartomer, or under the name EBECRYL® 80, EBECRYL ® 81, and EBECRYL 83 by the company CYTEC, and under the names PHOTOMER® 5662 and PHOTOMER® 5930 by the company COGNIS. The polyether (s) with (meth) acrylate group modified by reaction with an amino group is (or are) preferably present in a total content greater than or equal to 20% by weight, relative to total weight of the photocurable cosmetic composition, advantageously between 30 and 70% by weight relative to the total weight of the photocurable cosmetic composition, inclusive. b) Polyether Polymer with (meth) acrylate Group (s) A polyether polymer with (meth) acrylate groups preferably present in a composition according to the invention preferably comprises at least 2 (meth) acrylate functions, preferably 2 to 4 functions (meth) acrylates, and more preferably from 2.5 to 3.5 functions (meth) acrylates. Such a polymer has a molecular weight of preferably between 400 g / mol and 1500 g / mol, more preferentially between 500 g / mol and 1000 g / mol. This polymer is preferably obtained by esterification with (meth) acrylic acid of some or all of the terminal hydroxyl groups derived from homopolymers or copolymers of C 1 -C 6 alkylene glycols, such as polyethylene glycol, polypropylene glycol, copolymers of ethylene oxide and of propylene oxide preferably having a weight average molecular weight of less than 10 000 g / mol, polyethoxylated or polypropoxylated glycerols, polyethoxylated or polypropoxylated trimethylolpropanes, polyethoxylated or polypropoxylated pentaerythritols, polyethoxylated or polypropoxylated trimethylolpropanes, polyethoxylated or polypropoxylated di-pentaerythritols. Such polyols are described in particular in the US Pat. No. 5,543,557. Preferably, the polyether polymer (s) containing (meth) acrylate groups is (or are) obtained by esterification with (meth) acrylic acid of some or all of the terminal hydroxyl groups. from (poly) hydroxylated (s), preferably polyhydroxylated, and (poly) alkoxylated (s), preferably polyalkoxylated compounds. Preferably, the polyether polymer containing (meth) acrylate is chosen from the compounds of formula (I) below: ## STR5 ## wherein R 1 is CH 2 + O-Au (+ O ~ x O (I) 7 N / R 2 R'-C-CH 2 + O In which: ALKI and ALK2, which may be identical or different, represent a (C1-C6) alkyl group such as ethyl or propyl; and xi and x2, which may be identical or different, represent an integer greater than or equal to 1 such that inclusive between 1 and 1000; R 1 and R 2, which are identical or different, represent a hydrogen atom or a (C 1 -C 6) alkyl group such as methyl; preferably: i) a group of the following formula (II): ## STR2 ## wherein: ethyl or propyl; -x3 represents an integer greater than or equal to 1 as inclusive between 1 and 1000; -R3 represents a hydrogen atom or a (C1-C6) alkyl group such as methyl;group of formula (III) below: embedded image in which: ALK 4 represents a (C 1 -C 6) alkyl group such as ethyl or propyl; - x4 represents an integer greater than or equal to 1 such that inclusive inclusive between 1 and 1000; R 4 represents a hydrogen atom or a (C 1 -C 6) alkyl group such as methyl; iii) a group of formula (IV) below: () CH2-O-ALKS-O-ALK6 (IV) Formula (IV) in which: ALK5 and ALK6, identical or different, represent a group (CI-C6) alkyl such as ethyl or propyl; or iv) a group of the following formula (V): ## STR2 ## which: ALK7 and ALK8, which are identical or different, represent a (C1-C6) alkyl group such as ethyl or propyl;

x 'and x8, which are identical or different, represent an integer greater than or equal to 1, such as between 1 and 1000 inclusive;

- R7 and R8, identical or different, represent a hydrogen atom or a group (C1-15 C6) alkyl such as methyl; R "'being a hydrogen atom or a (C 1 -C 6) alkyl group such as ethyl, or an alkoxy group such as methoxy, or the group of formula (VI): OK (1 CH 2 + 0 ALK 9 ] (VI) Formula (VI) wherein: - ALK9 represents a (C1-C6) alkyl group such as ethyl or propyl;

- x9 represents an integer greater than or equal to 1 as inclusive between 1 and 1000; O - R9 represents a hydrogen atom or a (Ct-C6) alkyl group such as methyl; - and their mixtures; R "representing a hydrogen atom, or a (C1-C6) alkyl group such as ethyl, or an alkoxy group such as methoxy, or the group of formula (VII): ## STR2 ## Embedded image wherein: ALK10 represents a (C1-C6) alkyl group such as ethyl or propyl; x10 represents an integer greater than or equal to 1 as inclusive from 1 to 1000; R10 represents a hydrogen atom or a (C1-C6) alkyl group such as methyl; and mixtures thereof.

Preferably, the (meth) acrylate polyether polymer is chosen from polyethoxylated or polypropoxylated glycerol triacrylates, polyethoxylated or polypropoxylated trimethylolpropane triacrylates, polyethoxylated or polypropoxylated ditrimethylolpropane tetraacrylates, and polyethoxylated or polypropoxylated dipentaerythritol pentaacrylates, and their mixtures. Such polymers are marketed by CYTEC under the name EBECRYL® LEO 10501: molecular weight 470 g / mol, on average 3 acrylate functions per molecule. Polypropoxylated glycerol triacrylates are sold, for example, under the names SR 9019 and SR 9020 by the company SARTOMER, or under the names OTA-480 and EBECRYL® 53 by the company CYTEC. Polyethoxylated trimethylolpropane triacrylates are sold, for example, under the names SR 454, SR 499, SR 502 and SR 415 by the company SARTOMER, or under the names TMPEOTA and EBECRYL® 160 by the company CYTEC. Polypropoxylated trimethylolpropane triacrylates are sold, for example, under the name SR 492 by the company Sartomer. The polyether (s) with (meth) acrylate group (s) is (or are) preferably present in a total content greater than or equal to 20% by weight, relative to the total weight of the photocurable cosmetic composition. , advantageously between 30 and 70% by weight relative to the total weight of the photocurable cosmetic composition, inclusive. The polyether (meth) acrylate polymer (s) and the polyether (meth) acrylate group (s) modified by reaction with an amino group are preferably present in a higher total content or equal to 50% by weight, relative to the total weight of the photocurable cosmetic composition, advantageously between 55 and 99.9% by weight relative to the total weight of the photocurable cosmetic composition, inclusive. The polyether (s) with (meth) acrylate group (s) and the polyether (s) with (meth) acrylate group modified by reaction with an amino group are preferably present in the composition in a content respective total amount such that the weight ratio of the polyester (s) to the (meth) acrylate group (s) on the polyether (meth) acrylate polymer (s) is between 0.3 and 3, preferably between 0.5 and 2 inclusive. Photoinitiators The photoinitiators that can be used in the cosmetic compositions of the present invention are also known in the art and are described, for example, in the following articles: "Photoinitiators in the crosslinking of coatings", G. Li Bassi, Double Liaison - Chemistry of Paints 361, November 1985, pages 34-41; "Industrial applications of photoinduced polymerization", Henri Strub, L'Actualité Chimique, February 2000, pages 5 - 13; and "Photopolymers: Theoretical Considerations and Catch Response", Marc, J.M. Abadie, Double Liaison - Chemistry of Paints, No. 435-436, 1992, pp. 28-34.

These photoinitiators include - α-hydroxyketones, sold for example under the names DAROCUR® 1173 and 4265, IRGACURE® 184, 2959, and 500 by BASF, and ADDITOL® CPK by CYTEC, - a-aminoketones, marketed for example under the names IRGACURE® 907 and 369 by BASF, - the aromatic ketones marketed for example under the name Esacure® TZT by LAMBERTI. Mention may also be made of thioxanthones marketed for example under the name ESACURE® ITX by LAMBERTI, and quinones. These aromatic ketones most often require the presence of a hydrogen donor compound such as tertiary amines and especially alkanolamines. It is possible to mention the tertiary amine ESACURE® EDB sold by the company LAMBERTI. the α-dicarbonyl derivatives, the most common representative of which is benzyldimethylketal, marketed under the name IRGACURE® 651 by BASF. Other commercial products are marketed by LAMBERTI under the name ESACURE® KB 1. Acylphosphine oxides, such as, for example, bisacylphosphine oxides (BAPO) sold for example under the names IRGACURE® 819, 1700, and 1800, DAROCURO 4265, LUCIRIN® TPO, and LUCIRIN® TPO-L by BASF.

A particular group of photoinitiators useful in the photocurable cosmetic compositions of the present invention are copolymerizable photoinitiators. These are molecules comprising both a photoinitiator group capable of photoinduced radical scission and at least one ethylenic double bond.

The photoinitiators of this group have the advantage over the conventional photoinitiators listed above that they can be integrated, via the double bond, in the macromolecular system. This possibility reduces the content of free residual photoinitiators that have not undergone a photoinduced radical cutoff and consequently improves the safety of the cosmetic compositions.

Examples of such copolymerizable photoinitiators are the acrylated benzophenone derivatives marketed by CYTEC under the names EBECRYL® P36 and EBECRYL® P37.

In a preferred embodiment of the invention, polymeric photoinitiators or photoinitiators attached to a molecule of high molecular weight are used. The choice of such a high mass photoinitiator has the same advantage as the selection of exclusively polymerizable copolymerizable components, namely a better safety of the photocurable cosmetic compositions due to the absence of very reactive small molecules capable of diffusing towards the neighboring biological substrates. . As for the copolymerizable components, the weight average molecular weight of the photoinitiator is preferably at least equal to 500 g / mol.

By way of example, mention may be made of the α-hydroxyketone oligomer corresponding to the following formula: ## STR3 ## which is marketed under the name ESACURE® KIP 150 by the company LAMBERTI.

The polymer to which the photoinitiator group is attached may optionally comprise one or more ethylenic double bonds possibly allowing the integration, in the macromolecular network, of photoinitiator molecules that have not undergone photoinduced cleavage. Examples of such high molecular weight photoinitiators carrying ethylenic double bonds are those corresponding to the following formulas: ## STR5 ## where n = 1 to R = H or -O ~ C-CH 3 or -0 ~ CH = CH2 II CH2 structures described in the following articles: S. Knaus, Pure Appl. Chem., A33 (7), 869 (1996); S. Knaus, J. Polym. Sci, Part A = Polym. Chem., 33, 929 (1995); and R. Liska, Rad'Tech Europe 97, Lyon, F, 1997, Conference Proceedings. The photo-crosslinkable cosmetic compositions of the present invention preferably employ a light-absorbing photoinitiator mixture at different wavelengths. It is thus possible to adapt the absorption spectrum of the compositions

Photocurable cosmetics with the emission spectrum of the light sources used. The content of the photoinitiator (s) used depends on a large number of factors such as, for example, the reactivity of the various components of the mixture, the presence of pigments or dyes, the desired crosslinking density, the intensity of the source. light or exposure time. To obtain satisfactory mechanical properties, the radical photoinitiator (s) is (or preferably) present in a total content greater than or equal to 0.1% by weight relative to the total weight of the composition. preferably between 1 and 5% by weight relative to the total weight of the composition. Preferably, the radical photoinitiator (s) is (are) present in a total content greater than or equal to 0.1% by weight relative to the total weight of the polymer (s) polyether group (meth) acrylate modified by reaction with an amino group, preferably between 0.5 and 3% by weight relative to the total weight of the polymer (s) polyether (meth) acrylate group modified by reaction with an amino group.

FILMOGENIC POLYMER Preferably, the cosmetic compositions of the present invention comprise at least one film-forming polymer. For the purposes of the present invention, the term "film-forming polymer" denotes a polymer capable of forming on its own (ie, in the absence of an auxiliary film-forming agent or of an external stimulus, for example of the UV type), a isolable film, especially continuous and adherent, on a support, especially on the nails. In the composition, it is possible to use a single film-forming polymer or a mixture of film-forming polymers. This film-forming polymer may be chosen from the group consisting of synthetic polymers, of radical type or of polycondensate type, polymers of natural origin and their mixtures. A film-forming polymer that is suitable for the invention may be chosen in particular from: polysaccharide derivatives, such as cellulose derivatives or guar gum derivatives. A preferred polysaccharide derivative suitable for the invention may be nitrocellulose or a polysaccharide ester or alkyl ether. The term "polysaccharide ester or alkyl ether" denotes a polysaccharide formed of repeating units comprising at least two identical or different rings and having a degree of substitution per saccharide unit of between 1.9 and 3, preferably of between 2.2 and 2.9, and more particularly between 2.4 and 2.8. By substitution is meant the functionalization of the hydroxyl groups as ester and / or alkyl ether functions, and / or the functionalization of the carboxylic groups as ester functions.

In other words, it may be a polysaccharide partially or totally substituted with ester and / or alkyl ether groups. Preferably, the hydroxyl groups may be substituted by ester and / or alkyl ether C2-C4 functions. Mention may in particular be made of cellulose esters, such as cellulose acetobutyrates or cellulose acetopropianates; cellulose alkylethers such as ethylcelluloses, and ethylguars; synthetic polymers such as polyurethanes, acrylic polymers, vinyl polymers, polyvinylbutyrals, alkyd resins and ketone / aldehyde resins, resins derived from aldehyde condensation products, such as arylsulfonamide formaldehyde resins such as resin toluene sulfonamide formaldehyde, aryl-sulfonamide epoxy resins or ethyl tosylamide resins; polymers of natural origin, such as plant resins such as dammars, elemi, copals, benzoin; gums such as shellac, sandalwood gum and putty gum. As film-forming polymer, the toluene sulfonamide formaldehyde resins "Ketjentflex MS80" from the company Akzo or "Santolite MHP", "Santolite MS 80" from the company Fontronno or "Resimpol 80" from the company Pan Americana, the alkyd resin, can especially be used. "BECKOSOL ODE 230-70-E" from the company DAINIPPON, the acrylic resin "ACRYLOID B66" of the company ROHM & HAAS, the polyurethane resin "TRIXENE PR 4127" from BAXENDEN, the acetophenone / formaldehyde resin marketed under the reference Synthetic Resin SK by Degussa. According to a particular preferred embodiment, the film-forming polymer is chosen from polysaccharides and polysaccharide derivatives, preferably from nitrocellulose and ethers and esters of polysaccharides, in particular from C2-C4, and more preferentially is chosen from acetobutyrates. cellulose, cellulose acetate propianates, ethylcelluloses, ethylguars and mixtures thereof. According to a particularly preferred embodiment, the film-forming polymer is chosen from cellulose derivatives such as nitrocellulose, cellulose acetate butyrate, and ethylcellulose.

According to one embodiment, a composition according to the invention comprises a total content of film-forming polymer (s) greater than or equal to 5%, in particular between 5 and 30% by weight, in particular between 7.5 and 25% by weight. % by weight, in particular between 10 and 20% by weight, relative to the total weight of the nail polish.

SOLVENTS The photocurable cosmetic compositions of the present invention may comprise at least one solvent selected from physiologically acceptable organic solvents. Said at least one organic solvent may in particular be chosen from: a) ketones which are liquid at ambient temperature, such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone and acetone, b) alcohols which are liquid at room temperature ambient temperature, such as ethanol, isopropanol, diacetone alcohol, 2-butoxyethanol or cyclohexanol; c) room temperature liquid glycols such as ethylene glycol, propylene glycol, pentylene glycol and glycerol, d) propylene glycol ethers which are liquid at ambient temperature, such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, dipropylene glycol mono-n-butyl ether, e) short-chain esters (comprising in total from 3 to 8 carbon atoms). carbon atoms) such as ethyl acetate, methyl acetate, propyl acetate, n-propyl acetate, iso-propyl acetate, n-buty acetate iso-butyl acetate, tert-butyl acetate, and isopentyl acetate, alkanes which are liquid at room temperature, such as decane, heptane, dodecane, cyclohexane, ) ambient temperature liquid aromatic hydrocarbons such as toluene and xylene, h) liquid silicones at room temperature and i) mixtures thereof. The solvent content in the composition may range from 5% to 50% by weight, relative to the total weight of the composition, and preferably from 10% to 30% by weight. Preferably, the composition comprises a solvent chosen from alcohols that are liquid at room temperature, short chain esters comprising in total from 3 to 8 carbon atoms, and their mixture. According to a particular embodiment of the composition according to the invention, the composition is free of solvent.

ADJUVANTS The photocurable cosmetic compositions of the present invention may further contain adjuvants, or additives, chosen in particular from pigments and dyes, plasticizers, coalescers, preservatives, waxes, thickeners, perfumes , UV filters, cosmetic actives for nail care, spreading agents, anti-foaming agents and dispersing agents.

Preferably, said photocurable cosmetic compositions of the present invention comprise at least one coloring agent chosen from pigments, and preferably from metal oxides, such as iron oxides.

The coloring agent (s) is (are) present in a total content greater than 0.1% by weight relative to the total weight of the composition, advantageously ranging from 0.2 to 1% by weight relative to to the total weight of the composition.

Of course those skilled in the art will take care to choose these optional adjuvants and additives so that the advantageous properties of the compositions according to the invention are not, or not substantially impaired by the addition envisaged.

When the composition comprises pigments and / or dyes, it is particularly appropriate to adapt the absorption spectrum of the pigments and / or dyes used to that of the photoinitiators, or conversely the absorption spectrum of the photoinitiators to that of the pigments and / or or dyes used, to prevent these two types of compounds absorb light at the same wavelengths. Indeed, the absorption of light by the pigments and / or dyes would render almost totally ineffective the photoinitiators present beyond a certain depth of the coating.

The present invention also relates to a process for the cosmetic coating of natural nails or false nails.

This process comprises: a step of applying a photocurable cosmetic composition containing, in a physiologically acceptable medium, (a) one or more oligomers and / or polymers containing ethylenic double bonds, the average number of ethylenic double bonds per molecule of oligomer and / or polymer being greater than 1, and (b) at least one radical photoinitiator, so as to form a film on nails or false nails, and a step of exposing the deposited film to a radiation of wave suitable for a time sufficient to induce the crosslinking of said film. When the composition comprises a volatile solvent such as a volatile organic solvent, the film is exposed to the radiation after evaporation of the solvent or water.

One embodiment of the method according to the invention consists in successively carrying out the steps of applying the composition and exposing the film a plurality of times, in particular twice in succession. According to another embodiment of the method according to the invention, the latter comprises a prior step of applying a layer to ensure a good adhesion (or base coat) transparent under the photocurable cosmetic composition. Preferably, this layer to ensure good adhesion free of coloring agent is transparent and the cosmetic composition comprises a coloring agent. Preferably, this layer to ensure good adhesion is also a photocurable cosmetic composition. According to another embodiment of the method according to the invention, the latter comprises a subsequent step of applying a transparent protective layer (or top coat) to the photocurable cosmetic composition. Preferably, this stain-free protection layer is transparent and the cosmetic composition comprises a coloring agent. Preferably, this protective layer is also a photocurable cosmetic composition.

According to another particular embodiment of the process of the present invention, the keratinous substrate (nails, false nails, eyelashes, false eyelashes, hair and hair prostheses) on which the photocurable cosmetic composition is deposited is already covered by a first coating. non-crosslinkable cosmetic, such as a base coat or conventional nail polish. The photocurable cosmetic composition then constitutes a protective layer (top coat) of the first non-crosslinkable cosmetic coating. The composition can also be deposited alone on the nail to protect it. In this embodiment, the photocurable cosmetic composition is preferably not colored, that is to say free of pigments and dyes.

The radiation suitable for crosslinking the cosmetic compositions of the present invention has a wavelength of between 210 and 600 nm, preferably between 250 and 400 nm, preferably between 350 and 400 nm. We can also consider the use of lasers.

In a preferred embodiment of the invention, a UV lamp is used and in particular a mercury vapor lamp, possibly doped with other elements, such as gallium, making it possible to modify the emission spectrum of the source. light.

The exposure time of the radiation deposited film depends on various factors such as the chemical nature and the content of the reactive components or the desired crosslinking density. For nail polish, it will generally seek to obtain satisfactory results for an exposure time of between 1 and 20 minutes, preferably between 2 and 10 minutes.

This curing time preferably does not correspond to the total crosslinking of the system, i.e. to the reaction of all the double bonds present. To guarantee a good performance of nail polishes over time, it is advantageous to obtain both a high crosslinking density at the surface of the film ensuring a good mechanical strength, and a low crosslinking at the interface coating-substrate essential for the good adhesion of the deposited film to the substrate.

Such a process can implement a UV lamp with a power of approximately 36 5 W. Exemplary embodiment: A nail polish having the following composition is prepared: polyether polymer with (meth) acrylate groups modified by reaction with an amino group (EBECRYL® LEO 10552 from CYTEC): 43% 10 - Polyether polymer with (meth) acrylate groups (EBECRYLLEO 10501 from CYTEC): 52.8% - Photoinitiator (ADDITOL CPK from CYTEC): 4% - Pigment (SUNPURO RED IRON OXIDE C33- 8001 of SUN): 0.2% The composition of the example is applied to the nails in the form of a film having a thickness of about 50 μm and this film is irradiated for 2 minutes with UV radiation emitted by a "Philips Original UVA" lamp (36W) marketed by Philips whose effective wavelength range is from 340 to 365 nm. The lamp is placed at a distance of about 50 cm from the nails and during the exposure period the hands are tilted alternately in one direction and the other so as to distribute the radiation uniformly over the entire surface of the nails. This operation is repeated two more times, so as to deposit 3 crosslinked layers on the nails. A layer of transparent nitrocellulose topcoat varnish is then applied to the surface of the deposit. We obtain a brilliant film of good behavior on the nail. It is understood in the context of the present invention that the weight percentages given for a compound or a family of compounds are always expressed as the dry weight of the compound in question.

Throughout the application, the expression "includes one" or "includes one" shall be understood to mean "containing at least one" or "comprising at least one", unless the contrary is specified.

Claims (18)

REVENDICATIONS1. Photocurable cosmetic composition, free from reactive monomers with a molecular mass of less than 400 g / mol comprising one or more ethylenic double bonds, comprising, in a physiologically acceptable medium: at least one polymer containing ethylenic double bonds, the average number of ethylenic double bonds per molecule of polymer being greater than 1, said at least one polymer comprising at least one polyether polymer containing groups (meth) acrylate modified by reaction with an amino group, and - at least one radical photoinitiator. The photocurable cosmetic composition according to claim 1, wherein the average number of ethylenic double bonds per polymer molecule is greater than or equal to 2. 3. photocurable cosmetic composition according to claim 1 or 2, further comprising at least one polymer polyether group (meth) acrylate unmodified by reaction with an amino group. 4. Photocurable cosmetic composition according to claim 1, 2 or 3, wherein the polymer (s) polyether (meth) acrylate group modified or not is (or are) obtained by esterification with the acid (Meth) acrylic part or all of the terminal hydroxyl groups derived from compounds (poly) hydroxylated (s), preferably polyhydroxylated, and (poly) alkoxylated (s), preferably polyalkoxylated. 5. Photocurable cosmetic composition according to claim 3 or 4, the (or) polymer (s) polyether group (meth) acrylate unmodified by reaction with an amino group differ only from (or) polymeric polyether groups (meth) acrylate modified by reaction with an amino group NHRaRb by the presence of this amino group, Ra representing a alkyl substituted by a hydroxy, alkoxy, tertiary amine or aryl, and Rb representing a hydrogen or an alkyl substituted by a hydroxy, alkoxy, tertiary amine or aryl, Ra and Rb may be bonded together to form a ring. 6. The photocurable cosmetic composition according to any one of the preceding claims, wherein the polymer (s) polyether group (meth) acrylate modified by reaction with an amino group, have the following formula (I '): O CH2 + O-ALKq_iO ~ / R x; XO 2 R R'-CH 2 + O-ALK q-20 x XR "Formula (I ') in which: -, identical or different, represent a single or double bond; ALKI and ALK2, identical or different, represent a group (C1-COalkyl) such as ethyl or propyl; xi and x2, which may be identical or different, represent an integer greater than or equal to 1, such as between 1 and 1000 inclusive, and R1 and RZ, which may be identical or different, represent a hydrogen atom or a group (C1-COalkyl such as methyl; 1 X ^ X, identical or different, represent a CH2 group when - is a double bond or X represents an amino group CH2NRaRb when - is a simple bond with Ra representing an optionally substituted alkyl with a hydroxy, alkoxy, tertiary amine or aryl, and Rb representing a hydrogen or an optionally substituted alkyl with a hydroxy, alkoxy, tertiary amine or aryl, Ra and Rb may be bonded together to form a cycle; * R 'representative t: i) a group of the following formula (II '): R3 (*) CH2 + 0 ALK3 30: (II') x; Formula (II ') wherein: - ALK3 represents a (C1-C6) alkyl group such as ethyl or propyl; x3 represents an integer greater than or equal to 1 as inclusive between 1 and 1000; R 3 represents a hydrogen atom or a (C 1 -C 6) alkyl group such as methyl; X being as previously defined; ii) a group of the following formula (III '): ## STR3 ## in which formula (III') in which: ALK 4 represents a (C 1 -C 6) alkyl group such as ethyl or propyl; 20- x4 represents an integer greater than or equal to 1 as inclusive between 1 and 1000; R 4 represents a hydrogen atom or a (C 1 -C 6) alkyl group such as methyl; X being as previously defined; iii) a group of the following formula (IV '): ## STR2 ## in which: ALK5 and ALK6, which are identical or different, represent a group (C1-); C6) alkyl such as ethyl or propyl; X being as previously defined; or iv) a group of the following formula (V '): ## STR3 ## x 'X (*) - CH2 - O CHZC-R' 'O CH2-f -O-ALKs ~ 8,077 x X 20 Formula (V') in which: ALK ~ and ALK8, identical or different, represent a (C 1 -C 6) alkyl group such as ethyl or propyl; V "- x 7 and x 8, which may be identical or different, represent an integer greater than or equal to 1, such as between 1 and 1000 inclusive, - R 7 and R 8, identical or different, represent a hydrogen atom or a group (CIC6) alkyl such as methyl; R "'being a hydrogen atom or a (C 1 -C 6) alkyl group such as ethyl, or a group alkoxy such as methoxy, or the group of the formula (VI ": OK () -CH 2 + 0ALK 9); Formula (VI) in which: ALK 9 represents a (C 1 -C 6) alkyl group such as ethyl or propyl; x 9 represents an integer greater than or equal to 1 such that inclusive between 1 and 1000; R 9 represents a hydrogen atom or a (C 1 -C 6) alkyl group such as methyl; X being as defined above; ; - and their mixtures wherein R "represents a hydrogen atom, or a (C 1 -C 6) alkyl group such as ethyl, or an alkoxy group such as methoxy, or the group of formula (VII '): R10 (1- CH2 + 0 ALK'0) xip7 (~ VU ') X Formula (VII') wherein: - ALK10 represents a (C1-C6) alkyl group such as ethyl or propyl; x X - x10 represents an integer greater than or equal to 1 as inclusive between 1 and 1000; - R10 represents a hydrogen atom or a (C1-C6) alkyl group such as methyl; - and their mixtures. The photocurable cosmetic composition according to one of the preceding claims, wherein the polyether (meth) acrylate group (s) modified by reaction with an amino group have a weight average molecular weight greater than 450, of preferably between 500 and 3000. 10 8. The photocurable cosmetic composition according to any one of the preceding claims 3 to 7, wherein the polymer (s) polyether group (meth) acrylate not modified by reaction with an amino group is (or are) present ( s) in a total content greater than or equal to 20% by weight, relative to the total weight of the photocurable cosmetic composition. The photocurable cosmetic composition according to any one of the preceding claims, wherein the polyether (meth) acrylate group (s) modified by reaction with an amino group is (or preferably) present (s). ) in a total content greater than or equal to 20% by weight, relative to the total weight of the photocurable cosmetic composition. The photocurable cosmetic composition according to any one of the preceding claims 3 to 9, wherein the polyether (meth) acrylate group (s) unmodified by reaction with an amino group and the polymer (s) polyether group (meth) acrylate modified by reaction with an amino group are present in the composition in a respective total content such that the weight ratio of (or) polymer (s) polyether group (meth) acrylate on the polymer (s) polyether (meth) acrylate group modified by reaction with an amino group is between 0.3 and 3. 11. The photocurable cosmetic composition according to any one of the preceding claims, in which the radical photoinitiator (s) is (are) chosen from α-hydroxyketones, α-aminoketones and aromatic ketones. preferably associated with a hydrogen donor compound, aromatic α-diketones, and acylphosphine oxides. 12. The photocurable cosmetic composition according to any one of the preceding claims, in which the radical photoinitiator (s) is (are) present in a total content greater than or equal to 0.1% by weight per relative to the total weight of the composition, preferably between 1 and 5% by weight relative to the total weight of the composition. 13. - photocurable cosmetic composition according to any one of the preceding claims, wherein the radical (or) photoinitiator (s) is (or are) present (s) in a total content greater than or equal to 0.1% by weight relative to to the total weight of the polymer (s) polyether group (meth) acrylate modified by reaction with an amino group, preferably between 0.5 and 3% by weight relative to the total weight of the polymer (s) (s) polyether group (meth) acrylate modified by reaction with an amino group. 14. The photocurable cosmetic composition according to any one of the preceding claims, characterized in that it contains one or more solvents chosen from physiologically acceptable organic solvents such as ketones, alcohols, glycols, propylene glycol ethers, short-chain esters. alkanes, aromatic hydrocarbons and silicones, all liquid at room temperature, and mixtures thereof. 15. photocurable cosmetic composition according to any one of the preceding claims, further comprising at least one coloring agent selected from pigments, and preferably from metal oxides, such as iron oxides. 16. The photocurable cosmetic composition according to any one of the preceding claims, wherein said composition is a nail polish. 17. A method of coating the nails and false nails comprising at least: a step of applying a photocurable cosmetic composition according to any one of claims 1 to 16, so as to form a film on the nails or false nails, and a step of exposing the deposited film to radiation of appropriate wavelength for a time sufficient to induce the crosslinking of said film. 18. The method of claim 17, comprising a subsequent step of applying a top coat, optionally photocrosslinkable, to the photocurable cosmetic composition.