FR2950249A1 - Use of dispersion of rigid particles of ethylene polymer stabilized in surface, by stabilizing agent, in a non-aqueous dispersion medium to generate a coloured effect and to generate goniochromatic effect and in cosmetic composition - Google Patents

Abstract

Use of dispersion of rigid particles of ethylene polymer stabilized in surface, by stabilizing agent, in a non aqueous dispersion medium to generate a coloured effect, is claimed.

Description

The present invention relates to the use of dispersions of polymer particles to generate optical effects, including color.

It is known to use in cosmetics dispersions of polymer particles, generally of nanometric size, in aqueous or organic media. Thus, in the European patent application EP-A-0749747, there is described a cosmetic composition comprising a dispersion of polymer particles in a non-aqueous medium, said dispersion being stabilized by addition of stabilizing polymers which bind non-covalently through physical interactions on the polymer particles. Also known from EP1704854 are cosmetic compositions comprising dispersions, in an organic medium, of particles obtained by self-assembly of soluble / insoluble block copolymers and formation of polymeric micelles. These dispersions make it possible to obtain deposits having good cosmetic properties, especially in terms of stability, adhesion to the keratinous substrate and good strength. However, none of these dispersions has been described as likely to produce an optical effect, or even color, particular and may be used in cosmetics.

To obtain color effects, it is known to use in the makeup compositions pigments and dyes; however, their use may raise difficulties, such as low UV resistance, alteration to light, insufficiently bright and bright color, or formulation constraints.

It is also known, to obtain a goniochromatic effect, to use interferential pigments. These are nevertheless relatively complex and expensive to manufacture. A goniochromatic effect can also be provided by an ordered network of monodisperse particles, as taught in particular in application W000 / 47167.

EP1895974, which describes cosmetic compositions that make it possible to generate color by means of an ordered network of monodisperse particles, said compositions comprising a cosmetically acceptable medium and particles comprising a core that is insoluble in the medium, can be cited from whose surfaces extend, in particular by grafting, soluble polymer chains in the medium. According to this application, the insoluble core may be organic or inorganic and the polymeric grafts may be of any chemical nature. However, the particles mentioned in this document are mainly transportable in aqueous media, media that are not suitable for all cosmetic compositions, especially makeup compositions generally anhydrous or containing an oily fatty phase. Moreover, the solids content of the aqueous dispersion prepared according to this application is about 1.2%; it may be advantageous to have dispersions having a higher solids content, for example of the order of 15 to 20% by weight, to avoid the formulation constraints related to the presence of too much phase liquid.

The present invention therefore aims to overcome these limitations and to propose dispersions, in an oily medium, of polymer particles capable of generating an optical effect.

The present invention therefore relates to the use of a dispersion of rigid particles of ethylene polymer stabilized at the surface by a stabilizing agent, in a non-aqueous dispersion medium, to generate a color effect.

The dispersions of polymer particles according to the invention have adequate cosmetic properties, and in particular a good behavior of the cosmetic composition, good stability over time, and make it possible to obtain a deposit which does not have any tack. The dispersions also have a high affinity for the oily media usually used in cosmetics. In addition, they may have a high level of dry matter while maintaining their stability.

In order to achieve the object of the present invention, it has been necessary to select the monomers forming the particle and its stabilizer in a specifically adapted manner. Thus, according to the present invention, it is desired to prepare rigid particles which will form a deposit on the keratinous substrate; during the drying of the dispersion, after evaporation of the organic medium, said particles can be organized and generate a color effect. One could for example speak of deposit of 'organized marbles'. To obtain a deposit likely to generate an optical effect, it should preferably consist of organized objects and large size, especially greater than 100 nm. To do this, the dispersion according to the invention very preferably comprises particles having approximately all the same diameter (that is to say monodisperse), of diameter greater than or equal to 100 nm and keeping their spherical shape at the temperature deposit formation, about 25 ° C. It has been found that the particular choice of monomers capable of forming the particles according to the invention, as well as the particular choice of the dispersion medium, could also make it possible to obtain a stable dispersion capable of comprising the particles in large quantities, leading to to a dispersion having a dry matter content much higher than that described in the state of the art. In order to obtain such a dispersion, the particles of which retain their spherical shape in the deposit, it is proposed to polymerize particular monomers capable of forming a rigid polymeric particle in the presence of a stabilizing agent. This makes it possible to obtain dimensionally stable particles that can be organized regularly and form colloidal crystals.

In a first embodiment of such a dispersion, the rigid particles may be obtained by polymerization of monomers, alone or as a mixture, chosen such that the glass transition temperature (Tg) of the resulting polymer is greater than or equal to 20 ° C.

In a second embodiment, the rigid particles may be obtained by polymerization of monomers of any Tg, alone or as a mixture, in the presence of at least one crosslinking agent. The dispersions according to the invention therefore consist of particles, generally spherical, of at least one ethylene polymer, stabilized at the surface by a stabilizer, in a non-aqueous dispersion medium. The polymers according to the invention can be homopolymers or copolymers, linear, branched, grafted, or even in stars. They can be statistic or alternated. Preferably, they are linear random copolymers. In the present invention, the Tg (or glass transition temperature) of the indicated polymers are theoretical Tg determined from the theoretical Tg of the constituent monomers of the polymer, which can be found in a reference manual, such as the Polymer Handbook 4th ed. (Brandrup, Immergut, Grulke), 1999, John Wiley. The Tg of a polymer can be determined according to the following relationship, the so-called Fox's law: -E, () Tg Tgi wi being the mass fraction of the monomer i in the polymer and Tgi being the glass transition temperature of the homopolymer of the monomer i (expressed in Kelvin). In the present description, the term "Tg monomer" refers to the monomer whose homopolymer has such a glass transition temperature.

According to the first embodiment, in order to obtain rigid particles whose Tg is greater than or equal to 20 ° C., it is possible to polymerize 60 to 99.9% by weight, relative to the total weight of monomers, of monomers. of Tg greater than or equal to 20 ° C, in particular 80-95% by weight of monomers with a Tg greater than or equal to 20 ° C; preferably, 100% by weight of the monomers capable of forming the particle are of Tg greater than or equal to 20 ° C. The monomers of Tg strictly below 20 ° C can therefore be present to form the particle, but in a minor amount, that is to say between 0.1 and 40% by weight, especially 5 to 20% by weight. , the total weight of monomers used to form the core of the particle.

According to the second embodiment, in order to obtain rigid particles, it is possible, during and / or after polymerization of the monomers, to crosslink the polymer with the aid of a crosslinking agent, in particular added in a quantity of 1 part by weight of crosslinker for 3 to 19 parts by weight of monomers (monomers used to form the polymeric particle, excluding the crosslinking monomers), preferably 1 part by weight of crosslinking agent per 3.5 to 12 parts by weight of monomers, and even better 1 part by weight of crosslinking agent for 4 to 9 parts by weight of monomers. In this case, the polymer can be obtained from monomers of Tg greater than 20 ° C and / or Tg monomers strictly below 20 ° C.

Preferably, in order to obtain rigid particles, 60 to 100% by weight, based on the total weight of monomers, of monomers with a Tg of greater than or equal to 20 ° C are polymerized; and during and / or after polymerization of the monomers, is crosslinked with the aid of a crosslinking agent, in particular added in an amount of 1 part by weight of crosslinking agent for 3 to 19 parts by weight of monomers, preferably 3, 5 to 12 parts by weight, more preferably 4 to 9 parts by weight.

Preferably, all or part of the monomers capable of forming the particle is chosen from the monomers that are insoluble in the liquid carbon medium of the dispersion.

By insoluble monomer is meant in the present description any monomer whose homopolymer is insoluble, 5% by weight, at 20 ° C, in the liquid carbon medium of the dispersion; the monomer as such may be soluble or insoluble in said medium. The insoluble monomers represent in particular 55 to 100% by weight, in particular 65 to 95% by weight, or even 70 to 85% by weight, of the total weight of monomers forming the particle.

As a monomer with a Tg greater than or equal to 20 ° C., which may be used to form all or part of the particle, the following monomers, and their salts, may be mentioned, alone or as a mixture:

(i) (meth) acrylates of formula CH2 = C (CH3) -COOR or CH2 = CH-COOR, in which R represents an alkyl group, linear, branched or cyclic, saturated or unsaturated, or even aromatic, comprising 1 to 32 carbon atoms, which may contain one or more substituents selected from -OH, the halogen atoms (F, Cl, Br, I) and -NR'R "with R 'and R", which are identical or different, selected from alkyls, linear or branched, C1-C4; and especially: methyl methacrylate, ethyl, cyclohexyl, isobutyl, butyl, tert-butyl, tetrahydrofurfuryl, dicyclopentenyloxyethyl, benzyl; tert-butyl acrylate, trifluoroethanol methacrylate (MATRIFE), 2-hydroxyethyl, 2-hydroxypropyl, dicyclopentyl, (meth) acrylates,

(ii) (meth) acrylamides of formula CH2 = C (CH3) -CONR'3R'4 or CH2 = CH-CONR'3R'4 in which: R'3 and R'4, which are identical or different, represent a hydrogen atom or an alkyl group, linear or branched, having from 1 to 6 carbon atoms, which may comprise one or more substituents chosen from -OH, = 0, the halogen atoms (F, Cl, Br, I and -NR'R "with R 'and R", which are identical or different, chosen from linear or branched C 1 -C 4 alkyls; or - R'3 represents a hydrogen atom and R'4 represents a 1,1-dimethyl-3-oxobutyl group; There may be mentioned dimethylaminopropylmethacrylamide; acrylamide, methacrylamide, N-tertbutylacrylamide, diacetoneacrylamide of formula CH2 = CHC (O) N HC (CH3) 2 -CH2-C (O) CH3; (iii) ethylenically unsaturated monomers comprising at least one carboxylic, phosphoric or sulphonic acid function, such as crotonic acid, maleic anhydride, itaconic acid, fumaric acid, maleic acid, styrene sulfonic acid, vinylbenzoic acid, vinylphosphoric acid, acrylic acid, methacrylic acid, acrylamidopropanesulfonic acid, acrylamidoglycolic acid, and their salts;

(iv) vinyl esters of formula R'6-COO-CH = CH2 in which R'6 represents a linear or branched C1-C6 alkyl group, a C3-C6 cyclic alkyl group and / or an aromatic group for example benzene, anthracene and naphthalenic type;

(v) monomers containing ethylenic unsaturation (s) comprising at least one tertiary amine function, such as 2-vinylpyridine and / or 4-vinylpyridine; - (vi) styrene and its derivatives;

Among the Mg monomers higher than 20 ° C more particularly preferred, mention may be made of methacrylic acid, acrylic acid; methyl methacrylate, ethyl, cyclohexyl, isobutyl, butyl, tert-butyl, tetrahydrofurfuryl, dicyclopentenyloxyethyl, benzyl; tert-butyl acrylate; trifluoroethanol methacrylate; 2-hydroxyethyl, 2-hydroxypropyl, dicyclopentenyl (meth) acrylates; dimethylaminopropylmethacrylamide; styrene and its derivatives, vinyl acetate; and their mixtures. As monomer of Tg strictly below 20 ° C, which can be used to form the particle, mention may be made, alone or as a mixture, of the following monomers, as well as their salts: 530 - perfluorooctyl acrylate, butyl isobutyl, methyl, methoxyethyl, cyclohexyl, ethoxy-2-ethyl; dimethylaminoethyl methacrylate of ethoxy-2-ethyl; the ethylenic monomers whose ester group contains silanes, silsesquioxanes, siloxanes, carbosiloxane dendrimers as described in patent EP 0 963 751, with the exception of monomers containing only one silicon atom such as methacryloxypropryl; trimethoxysilane; and in particular (meth) acryloxypropyltris (trimethylsiloxy) silane, 3- (meth) acryloxypropylbis (trimethylsiloxy) methylsilane, (meth) acryloxymethyltris (trimethylsiloxy) silane, (meth) acryloxymethylbis (trimethylsiloxy) methylsilane.

Among the crosslinking agents that may be used, there may be mentioned any monomer capable of generating a three-dimensional network, thus comprising at least two functional sites capable of reacting simultaneously or sequentially to bind polymer chains; in particular, mention may be made of multifunctional monomers of diacrylate or dimethacrylate type; the following monomers are particularly preferred, alone or as a mixture,: allyl (meth) acrylate, cinnamoyl (meth) acrylate, glycidyl (meth) acrylate, pentaerythritol tetra (meth) acrylate, di (meth) acrylate, ethylene glycol (meth) acrylate, pentaerythritol tri (meth) acrylate, divinylbenzene, trivinylbenzene, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, bisphenol-A di (meth) acrylate, trimethylolpropane tri (meth) acrylate; monomers comprising an isocyanate side function which, after addition of diamine, dialcohol or amino alcohol, will form a urea or urethane linkage.

The polymer particles are surface stabilized. In a first embodiment, the particles may be stabilized at the surface as the polymerization progresses, thanks to a stabilizer which may be in particular a block polymer, a graft polymer, and / or a random polymer, alone or as a mixture . The stabilization can be carried out by any known means, and in particular by polymerization in the presence of the stabilizer. Preferably, the stabilizer is present in the mixture at the start of the polymerization. However, it is also possible to add it continuously, especially when continuously adding monomers. In a second embodiment, the polymer may be synthesized in a synthetic solvent, then dispersed in a non-aqueous dispersion medium by adding the dispersant, and the evaporated synthetic solvent.

It is possible to use from 0.1 to 30% by weight of stabilizer relative to the weight of the initial monomer mixture, and preferably from 1 to 25% by weight, preferably from 2 to 20% by weight, or even from 3 to 15% by weight. weight.

When a grafted and / or sequenced polymer is used as a stabilizer, the synthesis solvent is preferably chosen in such a way that at least a part of the grafts or sequences of said polymer-stabilizer is soluble in said solvent, the other part of the grafts or sequences not being soluble. The polymer-stabilizer used in the polymerization must be soluble or dispersible in the synthesis solvent. In addition, a stabilizer having a part (sequences, grafts or other) which has a certain affinity for the polymer formed during the polymerization is preferably chosen. When a random polymer is used as the stabilizer, it is preferably selected so that it has a sufficient amount of moieties rendering it soluble in the contemplated synthetic solvent.

It is especially possible to use as stabilizer, alone or as a mixture:

(A) silicone polymers grafted with a hydrocarbon chain and hydrocarbon polymers grafted with a silicone chain.

(b) graft polymers having an insoluble polyacrylic backbone with soluble poly (12-hydroxystearic acid) type grafts. (C) grafted or sequenced block copolymers comprising at least one block of polyorganosiloxane type and at least one block of a polymer (i) resulting from the radical polymerization or (ii) resulting from a polycondensation, in particular of polyether type , polyester or polyamide, or a mixture thereof, said copolymer may comprise fluorinated entities;

As graft or block block copolymers comprising at least one block of polyorganosiloxane type and at least one block of a radical polymer, mention may be made of graft copolymers of acrylic / silicone type which may be used in particular when the non-aqueous medium is silicone.

When the grafted or sequenced block copolymers comprise at least one block of polyorganosiloxane type and at least one polyether block, the polyorganopolysiloxane block may in particular be a polydimethylsiloxane or a polyalkyl (C2-C18) methylsiloxane; the polyether block may be a C2-C18 polyalkylene, in particular polyoxyethylene and / or polyoxypropylene. It is thus possible to use the dimethicones copolyol or else the (C2-C18) alkylicone copolyol, optionally crosslinked. It is possible, for example, to use the dimethicone copolyol sold under the name "Dow Corning 3225C" by the company Dow Corning, 40 or the lauryl methicone copolyol sold under the name Dow Corning Q2-5200 by the company Dow Corning. lauryl dimethicone copolyol crosspolymer, for example KSG31 or KSG32 from Shin-Etsu, cetyl dimethicone copolyol such as DMC 3071 from GE, and dimethicone copolyol PPG-3-oleyl ether such as KF-6026 from Shin Etsu.

(d) block copolymers comprising at least one block A resulting from the polymerization of non-acrylic ethylenic monomer, and at least one block B resulting from the polymerization of vinyl monomer, in particular (meth) acrylic, (meth) acrylamide or styrene, or polyether, polyester or polyamide, or mixtures thereof. The non-acrylic ethylenic monomers may comprise one or more optionally conjugated ethylenic bonds, and in particular be dienes, conjugated or otherwise. By non-acrylic means without acrylic group, methacrylic, including without acrylate group, methacrylate. In particular, mention may be made of ethylene, butadiene, isobutylene, isoprene and mixtures thereof. When the ethylenic monomer comprises several optionally conjugated ethylenic bonds, the residual ethylenic unsaturations after the polymerization are generally hydrogenated. Thus, in known manner, the polymerization of isoprene leads, after hydrogenation, to the formation of ethylene-propylene block, and the polymerization of butadiene leads, after hydrogenation, to the formation of ethylene-butylene block. Block A may therefore be of the polyethylene, polypropylene, polybutylene or polyisobutylene type, and their copolymers. When selected from polyethers, it may be polyoxyethylene, polyoxypropylene and copolymers thereof. Block B resulting from the polymerization of vinyl monomer can in particular be a block of styrenic polymer. It is therefore particularly possible to mention diblock or triblock copolymers of the polystyrene / polyisoprene, polystyrene / polybutadiene type, such as those sold under the name of 'LUVITOL HSB' by BASF, of the polystyrene / copoly (ethylene-propylene) type, such as those sold. as 'KRATON' by Shell Chemical, preferably of the polystyrene-b-poly (ethylene-butylene) type (Kraton G1701) or polystyrene-bpoly (ethylene-butylene) -b-polystyrene (Kraton G1650).

As block copolymers comprising a block resulting from the polymerization of non-acrylic ethylenic monomer and a block of (meth) acrylic polymer such as polymethyl methacrylate, mention may be made of poly (methyl methacrylate) / polyisobutylene bi- or triblock copolymers or graft block copolymers with poly (methyl methacrylate) skeleton and polyisobutylene grafts.

As grafted or sequenced block copolymers comprising a block resulting from the polymerization of non-acrylic ethylenic monomer and a block of polyether such as a polyoxyalkylene C 2 -C 18, in particular polyoxyethylene and / or polyoxypropylene, mention may be made of the two-component copolymers. or triblock polyoxyethylene / polybutadiene or polyoxyethylene / polyisobutylene.

(e) alkyl-dimethicones in which the alkyl group comprises 6 to 32 carbon atoms, such as lauryl meticone and stearyl methicone, in particular Si tec LDM 3107 from ISP, cetyl dimethicone such as ABIL Wax 9801 , behenoxydimethicone such as Goldschmidt's ABIL 5440 - (f) the dimethiconol ester of formula: II in which R is an alkyl radical having 6 to 32 carbon atoms, such as dimethiconol behenate, and in particular the ULTRABEE products of NOVEON and Pecosil DB from Phoenix Chemical.

(g) alkylamidoamines having in particular 6 to 60 carbon atoms, especially 12 to 50, such as behenamidopropyldimethylamine and in particular Catemol 220 from Phoenix Chemical, of formula: ## STR2 ## The copolymers comprising at least one polyorganosiloxane part and fluorinated groups, and in particular the fluorinated or fluorosilicone silicones which may be represented by the formula: Wherein X is an integer of 3 to 12, preferably 5 to 10, especially x = 8; y is an integer of 2 to 6, preferably 2 or 3; and m and n are such that the molecular weight of the compound is between 5000 and 15000; and more particularly perfluorononyldimethicone, such as those sold under the name PECOSIL FSH-150 and 300 or PECOSIL FSL-150 and 300 by Phoenix Chemical;

When the synthesis solvent is apolar, it is preferable to choose as a stabilizer, a polymer providing the most complete coverage of the particles possible, several polymer-stabilizer chains then being adsorbed on a particle of polymer obtained by polymerization. In this case, it is preferred to use as stabilizer, either a graft polymer or a block polymer, so as to have a better interfacial activity. In fact, the sequences or grafts insoluble in the synthetic solvent provide a more voluminous coverage on the surface of the particles. When the liquid synthetic solvent comprises at least one silicone oil, the stabilizing agent is preferably selected from the group consisting of grafted or sequenced block copolymers comprising at least one block of polyorganosiloxane type and at least one block of a polymer radical or a polyether or a polyester such as polyoxypropylene and / or oxyethylenated blocks.

Preferably, the stabilizer is chosen from block copolymers comprising at least one block A resulting from the polymerization of non-acrylic ethylenic monomer, and at least one block B resulting from the polymerization of vinyl monomer, in particular (meth) acrylic, (meth) acrylamide or styrenic, or polyether, polyester or polyamide, or mixtures thereof.

The dispersion of polymer particles according to the invention also comprises a liquid dispersion medium, especially oily, carbonaceous or silicone, in which said particles are dispersed. By liquid medium is meant in particular a medium preferably having a viscosity of less than or equal to 7000 centipoise at 20 ° C. According to the invention, the medium is said to be carbonaceous, if it comprises at least 50% by weight, in particular from 50% to 100% by weight, for example from 60% to 99% by weight, or from 65% to 95% by weight. or from 70 to 90% by weight, relative to the total weight of the carbonaceous medium, of carbon compound, liquid at 25 ° C., having an overall solubility parameter according to the HANSEN solubility space of less than or equal to 17 (MPa 1 "2, or a mixture of such compounds.

The overall solubility parameter 8 according to the solubility space of Hansen is defined in the article "Solubility parameter values" of Grulke, in the work "Polymer Handbook" 3rd edition, Chapter VII, pages 519-559 by the relation: S = (dp2 + dp2 + dH2) 1/2 in which: - dD characterizes the LONDON dispersion forces resulting from the formation of dipoles induced during molecular shocks, - dp characterizes the DEBYE interaction forces between permanent dipoles, dH characterizes the specific interaction forces (hydrogen bond, acid / base, donor / acceptor, etc.) type. The definition of solvents in the three-dimensional solubility space according to HANSEN is described in the HANSEN article: "The three dimensional solubility parameters" J. Paint Technol. 39, 105 (1967).

Among the liquid carbon compounds having an overall solubility parameter according to the HANSEN solubility space of less than or equal to 17 (MPa) 1 "2, it is possible here to include liquid fatty substances, in particular oils, which may be chosen from natural or synthetic oils, carbonaceous, hydrocarbon, optionally fluorinated, optionally branched, alone or in admixture.

In particular, mention may be made of: vegetable oils formed by esters of fatty acids and of polyols, in particular triglycerides, such as sunflower oil, sesame or rapeseed oil, macadamia oil, soybean oil, sweet almond oil, calophyllum, palm oil, grape seed oil, maize, arara, cotton, apricot, avocado, jojoba, olive or cereal seed; linear, branched or cyclic esters having more than 6 carbon atoms, especially 6 to 30 carbon atoms; and especially isononyl isononanoate; and more particularly the esters of formula RCOOR 'in which R represents the residue of a higher fatty acid having from 7 to 19 carbon atoms and R' represents a hydrocarbon chain comprising from 3 to 20 carbon atoms, such as palmitates, adipates, myristates and benzoates, especially diisopropyl adipate and isopropyl myristate; hydrocarbons and in particular linear, branched and / or cyclic alkanes, which are volatile or non-volatile, such as C 5 -C 60, especially C 8 -C 16 isoparaffins, which may be volatile, such as isododecane or Parleam (hydrogenated polyisobutene), isohexadecane, cyclohexane, or 'ISOPARs'; or paraffin oils, petroleum jelly, or hydrogenated polyisobutylene. ethers having 6 to 30 carbon atoms; ketones having 6 to 30 carbon atoms. aliphatic fatty alcohols having 6 to 30 carbon atoms, the hydrocarbon chain having no substitution group, such as oleic alcohol, decanol, dodecanol, octadecanol, octyldodecanol and linoleyl alcohol; than; polyols in particular having 6 to 30 carbon atoms, such as hexylene glycol; silicone oils, which are volatile or non-volatile, alone or as a mixture; Mention may in particular be made of polydimethylsiloxanes and polymethylphenylsiloxanes, optionally substituted with aliphatic and / or aromatic groups, optionally fluorinated, and / or containing functional groups such as hydroxyl, thiol and / or amine groups; and volatile silicones, in particular cyclic or linear silicones, such as cyclodimethylsiloxanes, cyclophenylmethylsiloxanes and linear dimethylsiloxanes, among which mention may be made of linear dodecamethylpentasiloxane (L5), octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexadecamethylcyclohexasiloxane and heptamethylhexyltrisiloxane; , heptamethyloctyltrisiloxane. esters having 2 to 5 carbon atoms, ethers having 2 to 6 carbon atoms, ketones 1 to 5 carbon atoms, monoalcohols having 1 to 5 carbon atoms. - their mixtures.

Preferably, the dispersion medium comprises at least one carbon compound chosen from: vegetable oils formed by esters of fatty acids and of polyols, in particular triglycerides, esters of formula RCOOR 'in which R represents the remainder a higher fatty acid having 7 to 19 carbon atoms and R 'represents a hydrocarbon chain having from 3 to 20 carbon atoms; linear or branched C8-C60 alkanes, which are volatile or non-volatile; cyclic, non-aromatic, C 5 -C 12 alkanes; volatile or non-volatile; ethers having 7 to 30 carbon atoms; Ketones having 8 to 30 carbon atoms; aliphatic fatty monoalcohols having 12 to 30 carbon atoms, the hydrocarbon chain having no substitution group, volatile silicone oils, such as D5.

Preferably, the dispersion medium comprises isopropyl myristate, octyldodecanol, C5-C60 isoparaffins, isododecane, isohexadecane, isononyl isononanoate, Parleam, D5 , or their mixture.

The polymer dispersion can be manufactured as described in EP-A-749747. In general, the polymerization can be carried out in dispersion, that is to say by precipitation of the polymer during formation, with protection of the particles formed using a stabilizer. It is therefore possible to prepare a mixture comprising the initial monomers and a radical initiator. This mixture is dissolved in a synthetic solvent. The monomers are soluble in the reaction medium, while the polymer is not soluble therein. As the polymerization proceeds, the polymer will precipitate and be stabilized by the stabilizer present. In this way, polymer particles protected at the surface by the stabilizer are obtained. The polymerization can be carried out directly in the non-aqueous medium which can therefore also act as a synthesis solvent. It is also possible to carry out the polymerization in a synthetic solvent and then carry out a solvent exchange, replacing the synthesis solvent with the non-aqueous medium.

Thus, when the non-aqueous medium chosen is a non-volatile oil, hydrocarbon or silicone, the polymerization can be carried out in an apolar organic solvent (synthetic solvent) and then the non-volatile oil (which must be miscible with said synthetic solvent) can be added. ) and selectively distilling the synthesis solvent. A synthetic solvent is thus preferably chosen such that the initial monomers and the radical initiator are soluble therein, and the polymer particles obtained therein are insoluble so that they precipitate during their formation. In particular, the synthesis solvent may be chosen from alkanes such as heptane, isododecane or cyclohexane. When the nonaqueous medium chosen is a volatile hydrocarbon or silicone oil, the polymerization can be carried out directly in the said oil, which thus also acts as a synthesis solvent. The monomers should preferably also be soluble therein, as well as the radical initiator, and the polymer obtained therein is insoluble. The monomers are preferably present in the synthesis solvent, before polymerization, in a proportion of 5-80% by weight. All the monomers may be present in the solvent before the start of the reaction, or a part of the monomers may be added as the polymerization reaction progresses. The radical initiator may be, for example , an azo compound or peroxide such as azobisisobutyronitrile or tert-butylperoxy-2-ethylhexanoate.

It is possible to add to the polymer dispersion a plasticizer so as to lower the Tg of the polymers used. The plasticizer may be chosen from plasticizers usually used in the field of application and in particular from compounds that may be solvents of the polymer. The plasticizer can be integrated during the synthesis or added once the synthesis is carried out.

As indicated above, the dispersion of polymer particles according to the invention is very preferably monodisperse, which means that it exhibits a very low particle size polydispersity, in particular less than or equal to 0.15, preferably less than or equal to 0.1; Particle size polydispersity (PDI) can in particular be determined by dynamic light scattering, using a Malvern Zetasizer Nano ZS; the sample previously diluted in isododecane is pipetted into a disposable plastic vat (4 transparent faces, 1 cm x 1 cm, 4 ml capacity) which is placed in the measuring cell; the measurements are carried out at 20 ° C. Measurements are made on the undiluted product and at the 1/3, 1/30, 1/300 and 1/1500 dilutions. The result retained corresponds to the dilution of the order of 1/300.

The polymer particles in dispersion according to the invention preferably have a spherical shape and a diameter greater than 100 nm, especially between 100 and 1000 nm, in particular between 125 and 800 nm, preferably between 150 and 700 nm (determined by diffusion dynamic of light, using a Malvern Zetasizer Nano ZS). Preferably, the dispersion according to the invention has a solids content of 5 to 40% by weight, especially 6 to 30% by weight, or even 7 to 25% by weight.

The dispersions according to the invention find a very particular application in cosmetics. Thus, they may be present in the cosmetic compositions according to the invention in an amount of 0.1 to 99% by weight, preferably 5 to 98% by weight, in particular 10 to 95% by weight, or even 50-90% by weight. by weight, of dispersion relative to the total weight of the composition.

The cosmetic compositions according to the invention also comprise a cosmetically acceptable medium, that is to say compatible with keratin materials such as the skin of the face or of the body, the lips, the hair, the eyelashes, eyebrows and nails.

The composition may advantageously comprise a fatty phase, which may itself comprise oils and / or preferably lipophilic solvents, as well as fats that are solid at room temperature, such as waxes, pasty fatty substances, gums and their mixtures. mixtures. Among the constituents of the fatty phase, mention may be made of volatile or nonvolatile oils, which may be chosen from natural or synthetic, carbonaceous, hydrocarbon, fluorinated or optionally branched oils, alone or as a mixture. The term "non-volatile oil" means an oil capable of remaining on the skin at ambient temperature and atmospheric pressure for at least one hour and having in particular a vapor pressure at room temperature (25 ° C.) and atmospheric pressure, which is not zero, less than 0.01 mmHg (1.33 Pa). Non-volatile carbonaceous oils, in particular hydrocarbon-based, of vegetable, mineral, animal or synthetic origin, such as liquid paraffin (or petrolatum), squalane, hydrogenated polyisobutene (Parleam), may especially be mentioned. perhydrosqualene, mink, macadamia, turtle, soya, almond oil, calophyllum, palm, grape seed, sesame, maize, arara, rapeseed oil, sunflower, cotton, apricot, castor oil, avocado, jubilee, olive or grain sprouts, shea butter; linear, branched or cyclic esters having more than 6 carbon atoms, especially 6 to 30 carbon atoms, such as the lanolic acid, oleic acid, lauric acid and stearic acid esters; esters derived from long chain (ie having from 6 to 20 carbon atoms) acids or alcohols, in particular esters of the formula RCOOR 'in which R represents the residue of a higher fatty acid having from 7 to 19 carbon atoms and R 'represents a hydrocarbon chain comprising from 3 to 20 carbon atoms, in particular the C 12 -C 36 esters, such as isopropyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, diisopropyl adipate, isononyl isononanoate, 2-ethylhexyl palmitate, 2-hexyl-decyl laurate, 2-octyl-decyl palmitate , myristate or 2-octyl-dodecyl lactate, di (2-ethyl hexyl) succinate, diisostearyl malate, glycerin or diglycerine triisostearate; higher fatty acids, especially C14-C22 fatty acids, such as myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, linoleic acid, linolenic acid or isostearic acid; higher fatty alcohols, especially C16-C22, such as cetanol, oleic alcohol, linoleic or linolenic alcohol, isostearyl alcohol or octyl dodecanol; and their mixtures.

Mention may also be made of decanol, dodecanol, octadecanol, liquid triglycerides of fatty acids containing from 4 to 10 carbon atoms, for instance triglycerides of heptanoic or octanoic acids and triglycerides of caprylic / capric acids; linear or branched hydrocarbons of mineral or synthetic origin, such as liquid paraffins and derivatives thereof, petroleum jelly, polydecenes, hydrogenated polyisobutene such as parleam; esters and synthetic ethers, in particular of fatty acids, for example purcellin oil, isopropyl myristate, 2-ethylhexyl palmitate, octyl-2-dodecyl stearate, erucate octyl-2-dodecyl, isostearyl isostearate; hydroxylated esters such as isostearyl lactate, octyl hydroxystearate, octyldodecyl hydroxystearate, diisostearyl malate, triisocetyl citrate, heptanoates, octanoates, decanoates of fatty alcohols; polyol esters such as propylene glycol dioctanoate, neopentyl glycol diheptanoate, diethylene glycol diisononanoate; and pentaerythritol esters; fatty alcohols having 12 to 26 carbon atoms such as octyldodecanol, 2-butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol. Mention may also be made of ketones which are liquid at ambient temperature, such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone and acetone; propylene glycol ethers which are liquid at room temperature, such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate or dipropylene glycol mono-butyl ether; short chain esters (having from 3 to 8 carbon atoms in total) such as ethyl acetate, methyl acetate, propyl acetate, n-butyl acetate, isopentyl; ethers which are liquid at ambient temperature, such as diethyl ether, dimethyl ether or dichlorodiethyl ether; liquid alkanes at room temperature such as decane, heptane, dodecane, isododecane, isohexadecane, cyclohexane; aromatic cyclic compounds which are liquid at room temperature, such as toluene and xylene; aldehydes which are liquid at room temperature, such as benzaldehyde and acetaldehyde, and mixtures thereof. Among the volatile compounds that may be mentioned are non-silicone volatile oils, in particular C 8 -C 16 isoparaffins such as isododecane, isodecane and isohexadecane. More preferentially, mention may be made of alkanes which are liquid at room temperature, volatile or otherwise, and more particularly decane, heptane, dodecane, isododecane, isohexadecane, cyclohexane and isodecane, and their mixtures. . The fatty phase may be present in a content ranging from 0.01 to 95%, preferably from 0.1 to 90%, more preferably from 10 to 85% by weight, relative to the total weight of the composition, and better from 30 to 80%.

The composition may also comprise a hydrophilic phase comprising water or a mixture of water and hydrophilic organic solvent (s) such as alcohols and in particular linear or branched lower monoalcohols having from 2 to 5 carbon atoms such as ethanol, isopropanol or n-propanol, and polyols such as glycerine, diglycerine, propylene glycol, sorbitol, pentylene glycol, and polyethylene glycols, or else ethers C2 and hydrophilic C2-C4 aldehydes. The water or the mixture of water and hydrophilic organic solvents may be present in the composition according to the invention in a content ranging from 0.1 to 80% by weight, relative to the total weight of the composition, and preferably from 1 to 70% by weight.

The composition according to the invention may also comprise waxes and / or gums. For the purposes of the present invention, the term "wax" means a lipophilic compound, solid at room temperature (25 ° C.), with a reversible solid / liquid state change, having a melting point of greater than or equal to 30 ° C. at 120 ° C. By bringing the wax to the liquid state (melting), it is possible to render it miscible with the oils that may be present and to form a homogeneous mixture microscopically, but by bringing the temperature of the mixture to room temperature, recrystallization of the mixture is obtained. wax in the oils of the mixture. The melting point of the wax can be measured using a differential scanning calorimeter (D.S.C.), for example the calorimeter sold under the name DSC 30 by the company METLER. The waxes may be hydrocarbon-based, fluorinated and / or silicone-based and may be of vegetable, mineral, animal and / or synthetic origin. In particular, the waxes have a melting point greater than 25 ° C. and better still greater than 45 ° C. As waxes that can be used in the composition of the invention, mention may be made of beeswax, carnauba or candelilla wax, paraffin wax, microcrystalline waxes, ceresin or ozokerite; synthetic waxes such as polyethylene or Fischer Tropsch waxes, silicone waxes such as alkyl or alkoxy dimeticone containing from 16 to 45 carbon atoms. The gums are generally high molecular weight polydimethylsiloxanes (PDMS) or cellulose gums or polysaccharides and the pasty substances are generally hydrocarbon compounds such as lanolines and their derivatives or else PDMSs.

The nature and quantity of the solid bodies depend on the mechanical properties and textures sought. As an indication, the composition may contain from 0.01 to 50% by weight of waxes, relative to the total weight of the composition and better still from 1 to 30% by weight.

The composition according to the invention may further comprise one or more dyestuffs chosen from water-soluble dyes, liposoluble dyes, and pulverulent dyestuffs such as pigments, nacres, and flakes well known to those skilled in the art. The dyestuffs may be present in the composition in a content ranging from 0.01 to 50% by weight, relative to the weight of the composition, preferably from 0.01 to 30% by weight. By pigments, it is necessary to include particles of any shape, white or colored, mineral or organic, insoluble in the physiological medium, intended to color the composition. By nacres, it is necessary to understand particles of any iridescent form, in particular produced by certain molluscs in their shell or else synthesized. The pigments may be white or colored, mineral and / or organic. Among the inorganic pigments, titanium dioxide, optionally surface-treated, zirconium oxide or cerium oxides, and oxides of zinc, iron (black, yellow or red) or chromium, the violet of manganese, ultramarine blue, chromium hydrate and ferric blue, metal powders such as aluminum powder, copper powder. Among the organic pigments, mention may be made of carbon black, D & C type pigments, and lacquers based on cochineal carmine, barium, strontium, calcium, aluminum.

The pearlescent pigments may be chosen from white pearlescent pigments such as mica coated with titanium, or bismuth oxychloride, colored pearlescent pigments such as titanium mica coated with iron oxides, titanium mica coated with, inter alia, blue. ferric oxide or chromium oxide, titanium mica coated with an organic pigment of the aforementioned type as well as pearlescent pigments based on bismuth oxychloride. Among the water-soluble dyes, mention may be made of the disodium salt of a culvert, the disodium salt of alizarin green, quinoline yellow, the trisodium salt of amaranth, the disodium salt of tartrazine, the monosodium salt of rhodamine and the disodium salt. fuchsin, xanthophyll, methylene blue.

The composition according to the invention may also comprise, in addition, one or more fillers, in particular in a content ranging from 0.01% to 50% by weight, relative to the total weight of the composition, preferably ranging from 01% to 30% by weight. By fillers, it is necessary to include particles of any form, colorless or white, mineral or synthetic, insoluble in the medium of the composition regardless of the temperature at which the composition is manufactured. These fillers serve in particular to modify the rheology or the texture of the composition. The fillers can be mineral or organic of any form, platelet, spherical or oblong, irrespective of the crystallographic form (for example sheet, cubic, hexagonal, orthorhombic, etc.). Mention may be made of talc, mica, silica, kaolin, polyamide (Nylon®) powders (Orgasol® from Atochem), poly-R-alanine and polyethylene, tetrafluoroethylene polymer powders (Teflon® ), lauroyl-lysine, starch, boron nitride, polymeric hollow microspheres such as those of polyvinylidene chloride / acrylonitrile such as Expancel® (Nobel Industrie), copolymers of acrylic acid (Polytrap®) from Dow Corning) and silicone resin microbeads (Toshiba's Tospearls®, for example), elastomeric polyorganosiloxane particles, precipitated calcium carbonate, magnesium carbonate and hydrocarbonate, hydroxyapatite, hollow silica microspheres (Silica Beads® from Maprecos), glass or ceramic microcapsules, metal soaps derived from organic carboxylic acids containing from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, exemp zinc, magnesium or lithium stearate, zinc laurate, magnesium myristate.

The composition may further comprise an additional polymer such as a film-forming polymer. According to the present invention, the term "film-forming polymer" means a polymer capable of forming on its own or in the presence of an auxiliary film-forming agent, a continuous and adherent film on a support, in particular on keratin materials. Among the film-forming polymers that may be used in the composition of the present invention, mention may be made of synthetic polymers, of radical type or of polycondensate type, polymers of natural origin and their mixtures, in particular acrylic polymers, polyurethanes , polyesters, polyamides, polyureas, cellulosic polymers such as nitrocellulose.

The composition according to the invention may also comprise ingredients commonly used in cosmetics, such as vitamins, thickeners, gelling agents, trace elements, softeners, sequestering agents, perfumes, alkalizing or acidifying agents, preservatives, sunscreens, surfactants, antioxidants, anti-hair loss agents, anti-dandruff agents, propellants, ceramides, or mixtures thereof. Of course, those skilled in the art will take care to choose this or these optional additional compounds, and / or their quantity, in such a way that the advantageous properties of the composition according to the invention are not, or not substantially, impaired by the proposed addition.

The composition according to the invention may be especially in the form of sus-pension, dispersion, especially organic solution, gel, emulsion, in particular emulsion oil-in-water (O / W) or water-in-oil (W / O), or multiple (W / O / E or polyol / H / E or O / W / H), in the form of cream, paste, foam, dispersion of vesicles including ionic lipids or not, two-phase or multiphase lotion, spray, powder, stick.

Those skilled in the art may choose the appropriate dosage form, as well as its method of preparation, on the basis of its general knowledge, taking into account, on the one hand, the nature of the constituents used, in particular their solubility in the support, and on the other hand, of the application envisaged for the composition.

The dispersions according to the invention are therefore ultimately formed of rigid polymeric particles, which preferably remain spherical, monodisperse in size, of fairly large diameter (preferably greater than 100 nm), and will lead to regularly organized the observation temperature (25 ° C). Thus, the deposit retains the structure of the particles and is organized, which generates a color or optical effect, of interest especially for makeup, hair coloring, conditioner, skincare and / or solar applications. In addition, said dispersion being in an oily medium, it becomes easy to formulate it in cosmetic compositions based on oily medium commonly used in cosmetics, in particular anhydrous media. Finally, it should be noted that the optical / color effect can be obtained without the addition of pigment, dye, mineral or metallic particle, chromophore and / or brightener usually used in cosmetics.

The composition according to the invention may be a makeup composition, especially a complexion product such as a foundation, a blush or an eyeshadow; a lip product such as lipstick, lip care, lip gloss; a concealer product; a blush, a mascara, an eyeliner; eyebrow make-up, lip pencil or eye pencil; nail product such as nail polish or nail care; a body make-up product; a hair makeup product (mascara or hairspray). The composition according to the invention may be a composition for protecting or caring for the skin of the face, neck, hands or body, in particular an anti-wrinkle, anti-fatigue composition which makes it possible to give the skin a radiance, a composition moisturizing or treating; an antisolar composition or artificial tanning. The composition according to the invention may also be a hair product, in particular for maintaining the hairstyle or shaping the hair; care, conditioning or hygiene of the hair; see the hair coloring. The hair compositions are preferably shampoos, conditioners, gels, styling lotions, blow-drying lotions, fixing and styling compositions such as lacquers or spray. The lotions may be packaged in various forms, in particular in vaporizers, pump-bottles or in aerosol containers to ensure application of the composition in vaporized form or in the form of foam. Such forms of packaging are indicated, for example when it is desired to obtain a spray, a mousse for fixing or treating the hair.

The composition according to the invention finds a particular application as a make-up composition, especially lipstick, gloss (lip gloss), eyeshadow, blush, nail polish or nail care All In particular, the composition according to the invention can be used to generate a color effect, in particular a deposit having a color effect, in particular a goniochromatic effect, on keratin materials.

The invention is illustrated in more detail in the following examples, given by way of illustration.

Comparative Example 1 Preparation of a Polyacrylate Dispersion In a 1 liter reactor, 270 g of isododecane, 103.5 g of heptane, 27 g of methyl acrylate and 13.5 g of copolymer are charged. polystyrene-b-poly (ethylene-butylene) block (Kraton G1701) and 1.35 g of tert-butylperoxy-2-ethylhexanoate (Trigonox 21S from Akzo Nobel). The mixture is stirred and raised to room temperature (25 ° C) at 90 ° C over 1 hour. Bleaching is noted at around 90 ° C. The temperature of the reaction medium is maintained at 90 ° C. with regulation of the temperature of the reaction medium.

Once the medium has turned white, 63 g of methyl acrylate and 0.99 g of Trigonox 21S are introduced. The mixture is kept at 90 ° C. for 3 hours, then the mixture is cooled to 25 ° C. Heptane is distilled and replaced during the distillation with 103.5 g of isododecane. A comparative dispersion in isododecane of methyl polyacrylate polymer particles is obtained with a solids content of 19.4%.

Comparative Example 2 Preparation of a Poly (Methyl Acrylate / Acrylic Acid) Dispersion In a 1 liter reactor, 270 g of isododecane, 103.5 g of heptane, 22.5 g of acrylate are charged. methyl, 4.5 g of acrylic acid, 13.5 g of polystyrene-b-poly (ethylene-butylene) block copolymer (Kraton G1701) and 1.35 g of 2-tertbutylperoxyethyl hexanoate (Akzo Trigonox 21S). Nobel). The mixture is stirred and raised to room temperature (25 ° C) at 90 ° C over 1 hour. Bleaching is noted at around 90 ° C. The temperature of the reaction medium is maintained at 90 ° C. with regulation of the temperature of the reaction medium. Once the medium became white, the following mixture was introduced over 1 hour: 63 g of methyl acrylate and 0.99 g of Trigonox 21S. The mixture is held for 3 hours at 90 ° C and then the whole is cooled to 25 ° C. Heptane is distilled and replaced during the distillation with 103.5 g of isododecane.

A comparative dispersion in isododecane of poly (methyl acrylate / acrylic acid) polymer particles with a solids content of 22.9% is obtained.

Example 1: Preparation of poly (methyl methacrylate / allyl methacrylate) dispersion In this example, allyl methacrylate is added during casting.

In a 1 liter reactor, 270 g of isododecane, 103.5 g of heptane, 27 g of methyl methacrylate and 13.5 g of polystyrene-bpoly (ethylene-butylene) block copolymer (Kraton G1701) are charged. and 1.35 g of tert-butylperoxy-2-ethylhexanoate (Trigonox 21S from Akzo Nobel). The mixture is stirred and raised to room temperature (25 ° C) at 90 ° C over 1 hour. Bleaching is noted at around 90 ° C. The temperature of the reaction medium is maintained at 90 ° C. with regulation of the temperature of the reaction medium. After the medium became white, the following mixture was introduced over 1 hour: 54 g of methyl methacrylate, 9 g of allyl methacrylate and 0.99 g of Trigonox 21S. The mixture is kept at 90 ° C. for 3 hours and then the whole is cooled to 25 ° C. Heptane is distilled and replaced during the distillation with 103.5 g of isododecane. A dispersion according to the invention is obtained in isododecane, polymer particles of poly (methyl methacrylate / allyl methacrylate), with a solids content of 21%.

Example 2 Preparation of a Dispersion of Poly (Methyl Methacrylate / Allyl Methacrylate) In this example, allyl methacrylate is added to the stock base.

In a 1 liter reactor, 270 g of isododecane, 103.5 g of heptane, 18 g of methyl methacrylate, 9 g of allyl methacrylate, 13.5 g of polystyrene-b-block copolymer are charged. poly (ethylene-butylene) (Kraton G1701) and 1.35 g of tert-butylperoxy-2-ethylhexanoate (Trigonox 21S from Akzo Nobel). The mixture is stirred and raised to room temperature (25 ° C) at 90 ° C over 1 hour. Bleaching is noted at around 90 ° C. The temperature of the reaction medium is maintained at 90 ° C. with regulation of the temperature of the reaction medium. After the medium became white, 63 g of methyl methacrylate and 0.99 g of Trigonox 21S were introduced within 1 hour. The mixture is kept at 90 ° C. for 3 hours and then the whole is cooled to 25 ° C. Heptane is distilled and replaced during the distillation with 103.5 g of isododecane. A dispersion according to the invention is obtained in isododecane, poly (methyl methacrylate / allyl methacrylate) polymer particles, with a solids content of 22.2%.

EXAMPLE 3 Preparation of a Dispersion of Poly (Methyl Methacrylate / Allyl Methacrylate) In this example, allyl methacrylate is added to the stock base.

In a 1-liter reactor, 270 g of isododecane, 103.5 g of heptane, 18 g of methyl methacrylate, 9 g of allyl methacrylate and 6.75 g of polystyrene-b-block copolymer are charged. poly (ethylene-butylene) (Kraton G1701) and 1.35 g of tert-butylperoxy-2-ethylhexanoate (Trigonox 21S from Akzo Nobel). The temperature was stirred and raised to room temperature (25 ° C) at 90 ° C in 1 hour. Bleaching is noted at around 90 ° C. The temperature of the reaction medium is maintained at 90 ° C. with regulation of the temperature of the reaction medium. After the medium became white, 63 g of methyl methacrylate and 0.99 g of Trigonox 21S were introduced within 1 hour. The mixture is kept at 90 ° C. for 3 hours and then the whole is cooled to 25 ° C. Heptane is distilled and replaced during the distillation with 103.5 g of isododecane. A dispersion according to the invention is obtained in isododecane of poly (methyl methacrylate / allyl methacrylate) polymer particles with a dry extract of 19.8%.

EXAMPLE 4 Preparation of a Dispersion of Poly (Methyl Methacrylate / Allyl Methacrylate) In this example, allyl methacrylate is added to the stock base. In a 1 liter reactor, 270 g of isododecane, 103.5 g of heptane, 18 g of methyl methacrylate, 9 g of allyl methacrylate, 4.5 g of polystyrene-b block copolymer are charged. poly (ethylene-butylene) (Kraton G1701) and 1.35 g of tert-butylperoxy-2-ethylhexanoate (Trigonox 21S from Akzo Nobel). The temperature was stirred and raised to room temperature (25 ° C) at 90 ° C in 1 hour. Bleaching is noted at around 90 ° C. The temperature of the reaction medium is maintained at 90 ° C. with regulation of the temperature of the reaction medium. After the medium became white, 63 g of methyl methacrylate and 0.99 g of Trigonox 21S were introduced within 1 hour. The mixture is kept at 90 ° C. for 3 hours and then the whole is cooled to 25 ° C. Heptane is distilled and replaced during the distillation with 103.5 g of isododecane. A dispersion according to the invention is obtained in isododecane, polymer particles of poly (methyl methacrylate / allyl methacrylate) with a solids content of 20%. Example 5: Preparation of poly (methyl methacrylate / allyl methacrylate) dispersion In this example, allyl methacrylate is added to the stock base and to the casting. In a 1 liter reactor, 270 g of isododecane, 103.5 g of heptane, 18 g of methyl methacrylate, 9 g of allyl methacrylate, 4.5 g of polystyrene-b-block copolymer are charged. poly (ethylene-butylene) (Kraton G1701) and 1.35 g of tertbutyl-2-peroxyethyl hexanoate (Trigonox 21S from Akzo Nobel). The mixture is stirred and raised to room temperature (25 ° C) at 90 ° C over 1 hour. Bleaching is noted at around 90 ° C. The temperature of the reaction medium is maintained at 90 ° C. with regulation of the temperature of the reaction medium.

After the medium became white, 54 g of methyl methacrylate, 9 g of allyl methacrylate and 0.99 g of Trigonox 21S were introduced within 1 hour. The mixture is kept at 90 ° C. for 3 hours and then the whole is cooled to 25 ° C. Heptane is distilled and replaced during the distillation with 103.5 g of isododecane. A dispersion according to the invention is obtained in isododecane, polymer particles of poly (methyl methacrylate / allyl methacrylate) with a solids content of 19.9%.

EXAMPLE 6 Preparation of a Dispersion of Poly (Methyl Methacrylate / Allyl Methacrylate) In this example, allyl methacrylate is added to the stock base.

180 g of isododecane, 103.5 g of heptane, 90 g of dicaprylyl carbonate (non-volatile oil), 18 g of methyl methacrylate and 9 g of allyl methacrylate are charged to a 1-liter reactor. 5 g of polystyrene-b-poly (ethylene-butylene) block copolymer (Kraton G1701) and 1.35 g of 2-tertbutylperoxyethyl hexanoate (Akzo Nobel Trigonox 21S). The mixture is stirred and raised to room temperature (25 ° C) at 90 ° C over 1 hour. Bleaching is noted at around 90 ° C. The temperature of the reaction medium is maintained at 90 ° C. with regulation of the temperature of the reaction medium.

After the medium became white, 63 g of methyl methacrylate and 0.99 g of Trigonox 21S were introduced within 1 hour. The mixture is kept at 90 ° C. for 3 hours and then the whole is cooled to 25 ° C. Heptane is distilled and replaced during the distillation with 103.5 g of isododecane. A dispersion according to the invention is obtained in the isododecane of poly (methyl methacrylate / allyl methacrylate) polymer particles with a solids content of 44.5%; the polymer concentration is 19.9% in the isododecane / dicaprylyl carbonate mixture.

EXAMPLE 7 Preparation of a Polymethylmethacrylate Dispersion In a 250 ml three-necked flask, 33.8 g of isododecane, 12.9 g of heptane and 3.4 g of methyl methacrylate are charged. 69 g of triblock copolymer polystyrene-b- (polyethylene-butylene) -b-polystyrene (Kraton G1650) and 0.17 g of tert-butylperoxy-2-ethylhexanoate (Trigonox 21S from Akzo Nobel). The mixture is stirred and raised to room temperature (25 ° C) at 90 ° C over 1 hour. The reaction medium is left for 5 hours at 90 ° C. and then overnight at 25 ° C. The reaction medium becomes white. The mixture is heated to 90 ° C. and introduced in one hour: 7.9 g of methyl methacrylate and 0.12 g of Trigonox 21S. The mixture is kept at 90 ° C. for 3 hours and then the whole is cooled to 25 ° C. Heptane is distilled and replaced during the distillation with 12.9 g of isododecane. A dispersion according to the invention is obtained in isododecane, polymer particles of poly (methyl methacrylate) with a solids content of 18.4%.

Example 8 Characterization of the Dispersions Films having a thickness of between 10 and 100 μm (measurement on the wet film, before drying) were formed using the polymer dispersions in isododecane. The films are made on LENETA contrast map; the deposits are left for 24 hours at room temperature (25 ° C) for drying. The deposits are visually observed and the effect obtained is noted. For the polymer dispersion of Example 6, a drop of the dispersion is deposited on a BYK contrast card and then spread by friction on the card; it is allowed to dry for 24 hours, then it is observed visually and the effect obtained is noted.

The following results are obtained: Diameter * polydis- Thick-Observation (nm) Persistence (Q) Comparative 1 68 0.09 50 pm Transparent, colorless film; no observed color effect Comparative 2 176 0.2 10 μm transparent, colorless film: no observed color effect Example 3 123 0.05 10 μm rainbow effect Example 4 135 0.04 10 μm arc effect sky Example 5 133 0.05 10 pm rainbow effect Example 1 - - 10 pm rainbow effect Example 2 170> 0.3 100 pm blue / gray effect Example 7 - - 10 and 50 goniochromatic effect pm green / purple Example 6 250 0.05 Green / red goniochromatic effect drop * average diameter determined by dynamic light scattering (in nm) and its polydispersity index Q; with the aid of a Malvern Zetasizer Nano ZS (monodisperse dispersion from Q <0.1) It is found that the dispersions according to the invention show color effects, whereas the comparative dispersion forms a colorless film. Composition of mascara A mascara is prepared having the following composition: Modified hectorite (Bentone® 38V from Elementis) 2 g pigments 2 g Dispersion of Example 4 15 g MS * Isododecane qs 100 g * MS: dry matter The mascara, after application on the eyelashes, is considered very satisfactory.

EXAMPLE 10 Lipstick Stick The following lipstick composition (% by weight) is prepared: polyethylene wax, 3%, dispersion of example 13% MS, isododecane, qs 100%, the composition obtained after application to the lips have good cosmetic properties.

Example 11 Lip Gloss A gloss having the following composition (% by weight) is prepared: Dispersion of Example 6 5% MS - Parléam qs 100% The composition obtained after application to the lips has good cosmetic properties.

Example 12: W / O Foundation A foundation composition is prepared comprising the following compounds: Phase A cetyl dimethicone copolyol (ABIL EM 90) 3% isostearyl diglyceryl succinate (IMWITOR 780K) 0.6% Pigments (oxides of hydrophobic iron and titanium) Io / o Dispersion of Example 1 2% MS Isododecane qs 100 g (on phase A) Phase B Magnesium sulphate 0.7 g Preservative qs Water qs 100 g (on phase B) The composition obtained has good cosmetic properties. EXAMPLE 13 Nail Polish A nail polish having the following composition is prepared: 4 g MS - Dispersion of Example 7 - Butyl acetate 25 g - Isopropanol 11 g40 - Hexylene Glycol 2.5 g - pigment 1 g - Hectorite modified (Bentone® 27V from Elementis) 1.3 g - Ethyl acetate qs 100 g After application to the nails, this varnish was judged to have very good cosmetic properties. 15 - Iron oxides 2 g - Petrolatum oil 6 g The powder is obtained as follows: Composition A is ground in a KENWOOD mill for about 5 minutes with gentle stirring, Composition B is added and ground set about 2 minutes at the same speed, then 3 minutes at a faster speed. The preparation is then sieved through a 0.16 mm sieve and this mixture is compacted in cups. A compacted powder having good cosmetic properties is obtained. EXAMPLE 14 Powder A compacted powder having the following composition is prepared: Composition A: Talc 10 g Bismuth oxychloride 10 g Zinc stearate 4 g Dispersion of Example 6 5 g MS Composition B Example 15 Qel for approval The following composition is prepared: 10 g - isopropyl palmitate - modified hectorite 0.15 g - oxyethylenated sorbitan septaoleate (400E) 5 g - dispersion of example 3 9.75 g MS - Parléam qs 100 g A gel having good cosmetic properties is obtained. Example 16: Care oil The following composition is prepared: 12.8 g MS - Dispersion of Example 2 - Jojoba oil 10 g Soybean oil 10 g A care oil is obtained which can be applied to the oil. body or face. 40

Claims (14)

REVENDICATIONS1. Use of a dispersion of rigid particles of ethylene polymer stabilized at the surface by a stabilizing agent, in a non-aqueous dispersion medium, to generate a color effect. 2. Use according to claim 1 for generating a goniochromatic effect. 3. Use according to one of the preceding claims, wherein the dispersed polymer particles have a diameter greater than 100 nm, especially between 100 and 1000 nm, in particular between 125 and 800 nm, preferably between 150 and 700 nm. nm. 4. Use according to one of the preceding claims, wherein the rigid particles are obtained by polymerization of monomers, alone or in mixture, chosen such that the glass transition temperature (Tg) of the resulting polymer is greater than or equal to 20 ° C. 5. Use according to claim 4, in which the rigid particles are obtained by polymerization of 60 to 100% by weight, relative to the total weight of monomers, of monomers with a Tg greater than or equal to 20 ° C, in particular 80-95%. by weight of monomers with a Tg greater than or equal to 20 ° C. 6. Use according to claim 5, wherein the monomers of Tg greater than 20 ° C are selected from methacrylic acid, acrylic acid; methyl, ethyl, cyclohexyl, isobutyl, butyl, tert-butyl, tetrahydrofurfuryl, dicyclopentenyloxyethyl, benzyl methacrylate; tert-butyl acrylate; trifluoroethanol methacrylate; 2- hydroxyethyl, 2-hydroxypropyl, dicyclopentenyl (meth) acrylates; dimethylaminopropylmethacrylamide; styrene and its derivatives, vinyl acetate; and their mixtures. 7. Use according to one of the preceding claims, wherein the rigid particles are obtained by crosslinking, in particular with the aid of a crosslinking agent added in an amount of 1 part by weight of crosslinking agent for 3 to 19 parts by weight. weight of monomers; preferably 1 part by weight of crosslinker for 3.5 to 12 parts by weight of monomers, and more preferably 1 part by weight of crosslinking agent for 4 to 9 parts by weight of monomers. 8. Use according to claim 7, wherein the crosslinking agents are chosen from, alone or in a mixture, the following monomers: allyl (meth) acrylate, cinnamoyl (meth) acrylate, glycidyl (meth) acrylate , pentaerythritol tetra (meth) acrylate, ethylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, divinylbenzene, trivinylbenzene, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, bisphenol-A di (meth) acrylate, trimethylolpropane tri (meth) acrylate; monomers comprising an isocyanate side function which, after addition of diamine, dialcohol or aminoalcohol, will form a urea or urethane linkage. 9. Use according to one of the preceding claims, wherein the stabilizing agent is present in a proportion of 0.1 to 30% by weight of stabilizer relative to the weight of the initial mixture of monomers, preferably from 1 to 25% by weight. weight, preferably from 2 to 20% by weight, or even from 3 to 15% by weight. 10. Use according to one of the preceding claims, wherein the stabilizing agent is selected from, alone or in mixture: - (a) silicone polymers grafted with a hydrocarbon chain and hydrocarbon polymers grafted with a silicone chain. (b) graft polymers having an insoluble polyacrylic backbone with soluble poly (12-hydroxystearic acid) type grafts. (c) grafted or sequenced block copolymers comprising at least one block of polyorganosiloxane type and at least one block of a polymer (i) resulting from the radical polymerization or (ii) resulting from a polycondensation, in particular of type polyether, polyester or polyamide, or a mixture thereof, said copolymer possibly comprising fluorinated entities; (d) block copolymers comprising at least one block A resulting from the polymerization of non-acrylic ethylenic monomer, and at least one block B resulting from the polymerization of vinyl monomer, in particular (meth) acrylic, (meth) acrylamide or styrene, or polyether, polyester or polyamide, or mixtures thereof. (e) alkyl dimethicones in which the alkyl group comprises 6 to 32 carbon atoms; (f) dimethiconol ester of formula: in which R is an alkyl radical having 6 to 32 carbon atoms; (g) alkylamidoamines having in particular 6 to 60 carbon atoms; (h) copolymers comprising at least one polyorganosiloxane part and fluorinated groups, and in particular fluorosilicones or fluorosilicones which may be represented by the formula: ## STR2 ## where ## STR2 ## n CH3 (CF2) x CF3 wherein x is an integer of 3 to 12; y is an integer from 2 to 6; and m and n are such that the molecular weight of the compound is from 5,000 to 15,000. 11. Use according to one of the preceding claims, in which the stabilizing agent is chosen from diblock or triblock copolymers of the polystyrene / polyisoprene, polystyrene / polybutadiene, polystyrene-b-poly (ethylenebutylene) and polystyrene-b type. -poly (ethylene-butylene) -b-polystyrene. 12. Use according to one of the preceding claims, wherein the non-aqueous dispersion medium comprises isopropyl myristate, octyldodecanol, C5-C60 isoparaffins, isododecane, isohexadecane, isononyl isononanoate, Parleam, D5, or their mixture. 13. Use according to one of the preceding claims, in a cosmetic composition. 14. Use according to one of the preceding claims, in a makeup composition, including lipstick, gloss (lip gloss), eyeshadow, blush, nail polish or nail care. . 295