FR2972630A1 - Cosmetic composition, useful e.g. as care product for skin and face, comprises dispersion of ethylene polymer particles that are surface-stabilized with stabilizer, in nonaqueous medium, where stabilizer is ethylenic polymer block - Google Patents

Abstract

Cosmetic composition comprises, in a medium, a dispersion of ethylene polymer particles that are surface-stabilized with a stabilizer, in a nonaqueous medium, where the stabilized ethylene polymer is rigid, and the stabilizer is an ethylenic polymer block comprising at least one first block and at least one second block, the first and second blocks are linked together via an intermediate segment comprising at least one monomer constituent of the first block and at least one monomer constituent of the second block.

Description

The present invention relates to a cosmetic composition comprising a dispersion of very particular polymer particles, in a non-aqueous medium, as well as to a cosmetic treatment method using it.

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 claim 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, from the surface can also be mentioned. which 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. Furthermore, the solids content of the aqueous dispersion prepared according to this application is about 1.20 / 0; it may be advantageous to have dispersions having a higher solids content, for example of the order of 15 to 200% by weight, in order to avoid the formulation constraints related to the presence of too much important liquid phase.

The present invention therefore aims to overcome these limitations and to provide dispersions, in a non-aqueous medium, of ethylene polymer particles capable of generating an optical effect.

An object of the present invention is a cosmetic composition comprising, in a cosmetically acceptable medium, a dispersion, in a non-aqueous medium, of ethylene polymer particles stabilized on the surface by a stabilizer, said stabilized ethylenic polymer being rigid, and said stabilizer being chosen from sequenced ethylenic polymers comprising at least a first block and at least a second block, said first and second blocks being interconnected by an intermediate segment comprising at least one constituent monomer of said first block and at least one constituent monomer of said block; said second sequence.

Stabilization by a block polymer as defined in the present invention has been found to provide several advantages. In particular, said sequenced polymer generally itself has advantageous film-forming properties, which will improve the properties of the film obtained with the polymer dispersion; in particular, the sequenced polymer can provide the net, while decreasing the tackiness of the deposit. Particularly advantageously, it can be noted an improvement in the brightness of the deposit or the film obtained from the dispersion according to the invention. Finally, thanks to its (meth) acrylic nature, similar to that of the polymer particles to be stabilized, the stabilizing block polymer has a better affinity for said particle than the polystyrene-b-poly (ethylenepropylene) type block polymers of the prior art. which were not of (meth) acrylic nature.

In the end, the deposits and films obtained according to the invention are advantageously more brilliant, less tacky and more resistant than those of the prior art. In addition, the dispersions of polymer particles according to the invention have adequate cosmetic properties, and in particular good behavior of the cosmetic composition, good stability over time, and allow to obtain a deposit which has little stickiness.

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 about 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 formation temperature. deposition, 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 non-aqueous liquid medium, could also make it possible to obtain a stable dispersion capable of comprising the particles in large quantities. leading 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 in such a way that the glass transition temperature (Tg) of the resulting ethylenic polymer is greater than or equal to at 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 on the surface by a stabilizer, in a non-aqueous medium. By "ethylenic" polymer is meant a polymer obtained by polymerization of at least two monomers, identical or different, comprising ethylenic unsaturation. Said ethylene polymer may in particular be a homopolymer or a vinyl copolymer, in particular (meth) acrylic copolymer. It may be chosen by those skilled in the art depending on its properties, depending on the subsequent application desired for the composition.

According to the first embodiment, the ethylenic dispersion polymer exhibits a glass transition temperature (Tg) greater than or equal to 20 ° C., preferably between 20 and 180 ° C., especially between 30 and 150 ° C., preferential 40 to 130 ° C.

In the present invention, the Tg (or glass transition temperature) indicated 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, Seme. ed, 1989, John Wiley, according to the following relation, 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 (K). In the present description, the term "Tg monomer" refers to the monomer whose homopolymer has such a glass transition temperature. The ethylenic polymers in dispersion according to the invention may be homopolymers or copolymers, linear, branched or even star. They can be statistical or alternating. Preferably, they are linear random copolymers. According to the first embodiment, in order to obtain rigid particles whose Tg is greater than or equal to 20 ° C., 60 to 99.90% by weight, based on the total weight of monomers, of monomers can be polymerized. of Tg greater than or equal to 20 ° C, especially 80-950 / 0 by weight of monomers with a Tg greater than or equal to 20 ° C; preferably, 1000/0 by weight of the monomers capable of forming the polymer in dispersion are of Tg greater than or equal to 20 ° C. The monomers of Tg strictly below 20 ° C can therefore be absent (00/0) or present, to form the particle, but preferably in a minor amount, that is to say between 0.1 and 400/0. by weight, especially 5 to 200/0 by weight, of the total weight of 25 monomers used to form the particle (and excluding crosslinking agent if appropriate). Monomers with a Tg lower than 20 ° C. and monomers with a Tg higher than 20 ° C. in any quantity may be used, the person skilled in the art being able, on the basis of his general knowledge, to determine the nature and proportions of each monomer to ultimately obtain a polymer having the required Tg, based on Fox's law.

According to the second embodiment, in order to obtain particles of rigid ethylenic polymer, it is possible, after polymerization of the monomers, to crosslink the polymer thus formed, with the aid of a crosslinking agent, in particular present in a quantity from 1 to 250% by weight, preferably 2 to 200% by weight, and more preferably 5 to 150% by weight, based on the total weight of monomers. In this case, the polymer can be obtained from monomers of Tg greater than 20 ° C and / or monomers Tg strictly less than 20 ° C.

Preferably, all or part of the monomers capable of forming the particles of ethylenic polymer is chosen from the monomers that are insoluble in the liquid medium of the dispersion. By insoluble monomer is meant in the present description any monomer whose homopolymer is insoluble. at 50/0 by weight, at 20 ° C, in the liquid medium of the dispersion; the monomer as such may be soluble or insoluble in said medium.

The insoluble monomers represent especially 55 to 1000/0 by weight, in particular 65 to 950/0 by weight, or even 70 to 850/0 by weight, of the total weight of monomers forming the ethylene polymer particles.

As a monomer of Tg greater than or equal to 20 ° C, which can be used to form the dispersion according to the invention, the following monomers, and their salts, may be mentioned, alone or as a mixture:

(I) (meth) acrylates of formula CH2 = C (CH3) -OOR or CH2 = CH-OOOR, in which R represents a linear, branched or cyclic alkyl group, saturated or unsaturated, or even aromatic, comprising 1 to 32 carbon atoms, which can comprise one or more substituents chosen from -OH, the halogen atoms (F, Cl, Br, 1) and -NR'R "with R 'and R", which are identical or different, chosen from from linear or branched C1-C4 alkyls; and especially: methyl methacrylate, ethyl, cyclohexyl, isobutyl, butyl, tert-butyl, tetrahydrofurfuryl, dicyclopentenyloxyethyl, benzyl; Tert-butyl acrylate, trifluoroethanol methacrylate (MATRIFE), 2-hydroxyethyl, 2-hydroxypropyl, dicyclopentenyl (meth) acrylates, (ii) (meth) acrylamides of formula CH 2 = 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 a linear or branched alkyl group, comprising: from 1 to 6 carbon atoms, which may comprise one or more substituents chosen from -OH, = 0, the halogen atoms (F, Cl, Br, 1) and -NR'R "with R 'and R", identical or different, chosen from alkyls, linear or branched, C1-C4; or - R'3 represents a hydrogen atom and R'4 represents a 1,1-dimethyl-3-oxobutyl group; Dimethylaminopropylmethacrylamide may be mentioned; Acrylamide, methacrylamide, N-tert-butylacrylamide, 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, styrenesulfonic acid, vinylbenzoic acid, vinylphosphoric acid, acrylic acid, methacrylic acid, acrylamidopropanesulfonic acid, acrylamidoglycolic acid, and salts thereof; (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) ethylenically unsaturated monomers comprising at least one tertiary amine function, such as 2-vinylpyridine and / or 4-vinylpyridine; - (vi) styrene and its derivatives; (vii) maleic anhydride.

Among the Mg monomers higher than 20 ° C more particularly preferred, mention may be made of 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.

As a monomer of Tg strictly below 20 ° C, which can be used to form the polymer particles in dispersion, the following monomers, and their salts, may be mentioned, alone or as a mixture: 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.

The ethylenic polymers in dispersion that can be used in the context of the present invention preferably have a number-average molecular weight (Mn) of between 2,000 and 1,000,000, in particular between 3,000 and 800,000, more preferably between 4,000 and 500,000, and even between 10,000 and 300,000.

Preferably, the monomers that can be used to prepare the ethylenic polymer in dispersion can be chosen from, alone or as a mixture, the esters of (meth) acrylic acid C1-C18, and in particular the (meth) methyl, ethyl, propyl, n-butyl, isobutyl, 2-ethylhexyl, tert-butyl, isooctyl, decyl, myristyl, stearyl and isobornyl acrylates; styrene, ethylhexylvinylether, dodecylvinylether, vinyl hexanoate; acrylic acid and methacrylic acid; maleic anhydride.

Preferably, the ethylenic polymer in dispersion is a copolymer of (meth) acrylic acid and alkyl (meth) acrylate, especially of C1-C4 alkyl. Among the crosslinking agents that may be used, mention may be made of any mono-mother 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, 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. The dispersion of ethylene polymer particles according to the invention thus comprises a non-aqueous medium in which said particles are dispersed. This non-aqueous medium consists of at least one non-aqueous compound, liquid at 25 ° C., having an overall solubility parameter according to the HANSEN solubility space less than or equal to 20 (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" 5th edition, Chapter VII, pages 519-559 by the relation: 30 _ (dp2 + dp2 + dH2) 1/2 in which: - dp characterizes the dispersion forces of LONDON resulting from the formation of di-poles induced during molecular shocks, - dp characterizes the interaction forces of DEBYE between permanent dipoles, 35 - dH characterizes the specific interaction forces (hydrogen bonds, 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 nonaqueous liquid compounds having an overall solubility parameter according to the HANSEN solubility space less than or equal to 20 (MPa) 1/2, there may be liquid fatty substances, in particular oils, which may be chosen from natural or synthetic oils, carbonaceous, hydrocarbon, fluorinated and / or silicone, optionally branched, alone or in admixture. Among these oils, mention may be made of vegetable oils formed by esters of fatty acids and of polyols, in particular triglycerides, such as sunflower, sesame or rapeseed oil, or esters derived from acids or long-chain alcohols (ie having from 6 to 20 carbon atoms), in particular the esters of formula RCOOR 'in which R represents the residue of a higher fatty acid containing 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. Mention may also be made of hydrocarbons and especially paraffin oils, petroleum jelly, hydrogenated polyisobutylene, C 6 -C 16 isoparaffins and volatile isoparaffins such as isododecane or 'ISOPARs'. It is also possible to mention linear or branched C8-C60, or cyclic, nonaromatic, C5-C12, volatile or non-volatile alcohols. Mention may also be made of silicone oils such as polydimethylsiloxanes and polymethylphenylsiloxanes, optionally substituted with aliphatic and / or aromatic groups, optionally fluorinated, or with functional groups such as hydroxyl, thiol and / or amine groups; and volatile silicone oils, in particular cyclic or linear oils, such as cyclodimethylsiloxanes, cyclophenylmethylsiloxanes and linear dimethylsiloxanes, among which mention may be made of linear dodecamethylpentasiloxane (L5), octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexadecamethylcyclohexasiloxane, Heptamethylhexyltrisiloxane, heptamethyloctyltrisiloxane. Mention may also be made of solvents, alone or as a mixture, chosen from linear, branched or cyclic esters having from 6 to 30 carbon atoms; ethers having 6 to 30 carbon atoms and ketones having 6 to 30 carbon atoms. Among the non-aqueous compounds that may be employed, mention may also be made of monoalcohols having an overall solubility parameter according to the HANSEN solubility space of less than or equal to 20 (MPa) 1/2, that is to say aliphatic fatty monoalcohols having at least 6 carbon atoms, especially 6 to 32, or even 12 to 30, the hydrocarbon chain having no substitution group. As monoalcohols according to the invention, mention may be made of oleic alcohol, decanol, dodecanol, octadecanol and linoleic alcohol.

Preferably, the non-aqueous medium comprises, alone or as a mixture: volatile silicone oils, in particular cyclic or linear oils, such as cyclodimethylsiloxanes and linear dimethylsiloxanes; esters of formula RCOOR 'in which R represents the residue of a higher fatty acid containing from 7 to 19 carbon atoms and R' represents a hydrocarbon-based chain containing from 3 to 20 carbon atoms, such as palmitates and adipates; myristates and benzoates, especially diisopropyl adipate and isopropyl myristate; - linear or branched C8-C60 alkanes, volatile or non-volatile; cyclic, non-aromatic, C 5 -C 12 alkanes; volatile or non-volatile; aliphatic fatty monoalcohols having 12 to 30 carbon atoms, the hydrocarbon chain having no substitution group.

The choice of the non-aqueous medium can be carried out easily by those skilled in the art depending on the nature of the monomers constituting the ethylene polymer and / or the nature of the stabilizer. The polymer dispersion can be manufactured as described in EPA-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. The stabilizer may be added in solid form, and will solubilize or self-disperse in the synthesis solvent; it can also be added in the form of a solution in a solvent compatible with the synthetic solvent. 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. Ethylenic polymer particles protected on the surface by the stabilizer are thus obtained. The polymerization can be carried out directly in the non-aqueous medium which can 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 oil, the polymerization can be carried out in an apolar organic solvent (synthetic solvent) and then the non-volatile oil (which must be miscible with the said solvent) is added. synthesis) and selectively distilling the synthesis solvent. A synthesis solvent is thus preferably chosen such that the initial monomers and the free-radical initiator are soluble therein, and the polymer particles obtained are insoluble therein so that they precipitate during their formation. In particular, the synthesis solvent can be chosen from alkanes such as heptane, isododecane or cyclohexane, or silicone oils such as D5 or L5. When the non-aqueous 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 5-800% 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; the initiators mentioned later in the description can also be used.

The polymer particles are surface stabilized.

In a first embodiment, the particles can be stabilized on the surface as the polymerization progresses; 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 monomers are also added continuously. 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 0.1 to 200% by weight of stabilizer relative to the weight of rigid ethylenic polymer, preferably 2 to 180% by weight, preferably 5 to 170% by weight, or even 8 to 160% by weight. .

The stabilizer that can be used in the context of the present invention is a sequenced ethylenic polymer comprising at least a first and at least a second sequence, said first and second sequences preferably being incompatible with each other, said first and second sequences being preferably incompatible with each other, said first and second sequences being preferably and second sequences being interconnected by a segment, preferably an intermediate sequence which comprises at least one constituent monomer of each of said two sequences. Such block ethylenic polymers are in particular described in the patent application EP1411069.

Preferably, said sequenced ethylenic polymer comprises at least a first block having a glass transition temperature (Tg) of greater than or equal to 40 ° C. and at least a second block having a glass transition temperature of less than or equal to 20 ° C. first sequence and said second sequence being interconnected by an intermediate segment, preferably random, comprising at least a first constituent monomer of said first block and at least a second constituent monomer of the second block, different from said first monomer.

Preferably, the first block having a glass transition temperature (Tg) greater than or equal to 40 ° C is derived in whole or in part from one or more first monomers which are such that the homopolymer prepared from these monomers has a glass transition temperature greater than or equal to 40 ° C. Preferably, the second block having a glass transition temperature of less than or equal to 20 ° C is derived in whole or in part from one or more second monomers which are such that the homopolymer prepared from these monomers has a temperature of glass transition less than or equal to 20 ° C.

By "sequenced" polymer is meant a polymer comprising at least 2 distinct sequences, preferably at least 3 distinct sequences.

By "ethylenic" polymer is meant a polymer obtained by polymerization of monomers comprising ethylenic unsaturation. The block ethylenic polymer used according to the invention is prepared exclusively from monofunctional monomers. This means that the sequenced ethylenic polymer does not contain multifunctional monomers which make it possible to break the linearity of a polymer in order to obtain a connected or even cross-linked polymer as a function of the multifunctional monomer content. The sequenced ethylenic polymer also does not contain a macromonomer; the term "macromonomer" means a monofunctional monomer having a pendant group of polymeric nature, and preferably having a molecular weight Mw of greater than 500 g / mol, or a polymer comprising on one of its ends a polymerizable terminal group or at least one ethylenic unsaturation, which are used for the preparation of a graft polymer. It is specified that the terms "first" and "second" sequences do not condition the order of said sequences (or blocks) in the polymer structure. The first and second sequences of the sequenced ethylenic polymer may be advantageously incompatible with each other. By "sequences incompatible with each other" is meant that the mixture formed by a polymer corresponding to the first block and a polymer corresponding to the second block is immiscible in the polymerization solvent. , predominantly by weight, of the sequenced polymer, at ambient temperature (25 ° C.) and atmospheric pressure (105 Pa), for a content of the mixture of said polymers greater than or equal to 50% by weight, relative to the total weight of the mixture of said and said polymerization solvent, it being understood that: i) said polymers are present in the mixture in a content such that the respective weight ratio ranges from 10/90 to 90/10, and that ii) each of the polymers corresponding to the first and second sequences have an average molecular weight (by weight or number) equal to that of the +/- 150/0 block polymer. In the case of a mixture of polymerization solvents, assuming two or more solvents present in identical mass proportions, said polymer mixture is immiscible in at least one of them. Of course, in the case of a polymerization carried out in a single solvent, the latter is the majority solvent.

The intermediate segment is preferably a sequence, or block, comprising at least one constituent monomer of the first block and at least one constituent monomer of the second block of the polymer; it can allow to "compatibilize" these sequences. Said intermediate segment is preferably a random copolymer. It generally has a glass transition temperature Tg between the glass transition temperatures of the first and second sequences. Preferably, said intermediate segment or sequence is derived essentially from monomers constituting the first sequence and the second sequence. By "essentially" is meant at least 850/0, preferably at least 900/0, better at 950/0 and even better at 1000/0.

The ethylenic block polymer according to the invention is advantageously filmogenic. By this is meant a polymer capable of forming, on its own or in the presence of an auxiliary film-forming agent, a continuous deposit on a support, in particular on keratin materials.

Preferably, the block ethylenic polymer does not comprise silicon atoms in its backbone. By "skeleton" is meant the main chain of the polymer, as opposed to the pendant side chains. Preferably, the block ethylenic polymer is not water-soluble, that is to say that the polymer is not soluble in water or in a mixture of water and linear or branched lower monoalcohols having from 2 to 5 atoms of carbon such as ethanol, isopropanol or n-propanol, without any change in pH, at an active ingredient content of at least 10% by weight, at room temperature (25 ° C). Preferably, the sequenced ethylenic polymer is not an elastomer. By this is meant a polymer which, when subjected to a stress to stretch it (for example 300/0 relative to its initial length), does not return to a length substantially identical to its initial length when stop the constraint.

Preferably, said sequenced ethylenic polymer has a polydispersity index Ip greater than 2, in particular between 2 and 9, preferably between 2.5 and 8, better still between 2.8 and 6. The polydispersity index Ip is equal to the ratio of the weight average mass Mw to the number average mass Mn. The weight average (Mw) and number (Mn) molar masses are determined by gel permeation liquid chromatography (THF solvent, calibration curve established with linear polystyrene standards, refractometric detector). The weight average mass (Mw) of the sequenced ethylenic polymer is preferably from 35,000 to 300,000, more preferably from 45,000 to 150,000 g / mol. The number average mass (Mn) of the sequenced ethylenic polymer is preferably from 10,000 to 70,000, more preferably from 12,000 to 50,000 g / mol. Preferably, the sequence having a Tg greater than or equal to 40 ° C has a Tg ranging from 40 to 150 ° C, preferably from 50 ° C to 120 ° C, and more preferably from 60 ° C to 120 ° C. The sequence having a Tg greater than or equal to 40 ° C may be a homopolymer or a copolymer.

In the case where this sequence is a homopolymer, it is derived from monomers which are such that the homopolymers prepared from these monomers have glass transition temperatures greater than or equal to 40 ° C. This first block may be a homopolymer consisting of a single type of monomer (the Tg of the corresponding homopolymer is greater than or equal to 40 ° C.).

In the case where the first block is a copolymer, it is derived from several monomers whose nature and concentration are chosen so that the Tg of the resulting copolymer is greater than or equal to 40 ° C.

The monomers whose homopolymers have a glass transition temperature greater than or equal to 40 ° C. are preferably chosen from the following monomers: methacrylates of formula CH 2 CC (CH 3) -000 R 2 in which R 2 represents a non-alkyl group; substituted, linear or branched, C1-C4, such as a methyl, ethyl, propyl or isobutyl group, or R2 represents a C4-C12 cycloalkyl group, preferably a C8-C12 cycloalkyl, mention may be made of isobornyl methacrylate, acrylates of formula CH 2 CHCH-COOR '2 in which R' 2 represents a C 4 to C 12 cycloalkyl group such as an isobornyl group or a tert-butyl group, the (meth) acrylamides of formula CH 2 = CHCONR 7 R 8 or CH 2 = C (CH 3) CONR 7 R 8, R 'CH 2 = C R 8 in which R 3 and R 4, which may be identical or different, represent a hydrogen atom or a C 1 -C 12 linear or branched alkyl group, such as a n-butyl, t-butyl, isopropyl, isohexyl, isooctyl, or is ononyle; or R, is H and R $ is 1,1-dimethyl-3-oxobutyl; mention may be made of N-butylacrylamide, N-t-butylacrylamide, N-isopropylacrylamide, N, N-dimethylacrylamide and N, N-dibutylacrylamide.

The first block is advantageously obtained from at least one acrylate monomer of formula CH2 = CH-000R and at least one methacrylate monomer of formula CH2 = C (CH3) -000R in which R, which is identical or different, is C4-C12cycloalkyl, preferably C8-C12cycloalkyl, preferably R is the same in the monomers; preferably, these monomers are acrylate and isobornyl methacrylate. The acrylate monomer and the methacrylate monomer are preferably in mass proposals of between 30:70 and 70:30, preferably between 40:60 and 60:40, in particular of the order of 50:50. The first block can be obtained exclusively from isobornyl acrylate and methacrylate, which are preferably in acrylate: methacrylate mass proposals of between 30:70 and 70:30, preferably between 40:60 and 60:40. , in particular of the order of 50:50.

The proportion of the first block within the sequenced ethylenic polymer is preferably from 20 to 900% by weight, more preferably from 30 to 800% by weight and more preferably from 60 to 800% by weight of the polymer.

Preferably, the sequence having a Tg of less than or equal to 20 ° C has a Tg ranging from -100 ° C to 20 ° C, preferably from -80 ° C to 15 ° C, and more preferably from -50 ° C to 10 ° C. ° C, especially from -30 ° C to 0 ° C.

The sequence having a Tg of less than or equal to 20 ° C may be a homopolymer or a copolymer. In the case where this sequence is a homopolymer, it is derived from monomers which are such that the homopolymers prepared from these monomers have glass transition temperatures less than or equal to 20 ° C. This first block may be a homopolymer consisting of a single type of monomer. In the case where the second block is a copolymer, it is derived from several monomers whose nature and concentration are chosen so that the Tg of the resulting copolymer is less than or equal to 20 ° C.

The monomers whose homopolymers have a glass transition temperature of less than or equal to 20 ° C. are preferably chosen from the following monomers: acrylates of formula CH 2 CHCHCOOR 3 in which R 3 represents an unsubstituted C 1 to C 12 alkyl group , linear or branched, with the exception of the tert-butyl group, in which is (are) optionally intercalated (s) one or more heteroatoms selected from O, N, S; mention may be made of isobutyl acrylate, - methacrylates of formula CH 2 CC (CH 3) -COOR 4, in which R 4 represents a linear or branched C 6 to C 12 unsubstituted alkyl group, in which is (are) optionally intercalated (s) one or more heteroatoms selected from O, N and S; vinyl esters of formula R 5 -CO-O-CH =CH 2 where R 5 represents a linear or branched C 4 to C 12 alkyl group; vinyl alcohol and C4 to C12 alcohol ethers; C4 to C12 N-alkyl acrylamides, such as N-octylacrylamide; and mixtures thereof.

The monomers having a Tg less than or equal to 20 ° C are preferably chosen from isobutyl acrylate, 2-ethylhexyl acrylate, and mixtures thereof in all proportions.

According to a preferred embodiment of the invention, (i) the monomers whose homopolymers have a glass transition temperature greater than or equal to 40 ° C. are chosen from the following monomers: methacrylates of formula CH 2 = C (CH 3) Wherein R 2 represents a linear or branched C 1 -C 4 unsubstituted alkyl group, such as a methyl, ethyl, propyl or isobutyl group, or R 2 represents a C 4 to C 12 cycloalkyl group, preferably a cycloalkyl group; at C12 to C12; acrylates of formula CH2 = CH-COOR'2 in which R'2 represents a C4-C12 cycloalkyl group such as an isobornyl group or a tert-butyl group; and (ii) the monomers whose homopolymers have a glass transition temperature of less than or equal to 20 ° C are chosen from the following monomers: acrylates of formula CH 2 = CHCOOR 3 in which R 3 represents an unsubstituted C 1 to C 12 alkyl group , linear or branched, with the exception of the tert-butyl group, in which is (are) optionally intercalated (s) one or more heteroatoms selected from O, N, S; mention may be made of isobutyl acrylate, - methacrylates of formula CH 2 CC (CH 3) -COOR 4, in which R 4 represents a linear or branched C 6 to C 12 unsubstituted alkyl group, in which is (are) optionally intercalated (s) one or more heteroatoms selected from O, N and S.

Said first and / or second sequences may comprise, in addition to the monomers indicated above, one or more other monomers called additional monomers, different from the main monomers mentioned above. In particular, each of the first and / or second sequences comprises at least one additional monomer. The nature and amount of these additional monomers are chosen such that the sequence in which they are located has the desired glass transition temperature. In particular, the first sequence and / or the second sequence may comprise, as additional monomer, (meth) acrylic acid, preferably acrylic acid. Particularly preferably, the second block comprises (meth) acrylic acid, preferably acrylic acid.

In particular, said block ethylenic polymer that can be used as a stabilizer, is such that: the first block is obtained from at least one monomer of formula CH2 = CH-OOOR2 in which R2 represents a C4 cycloalkyl group; C12, preferably isobornyl acrylate, and at least one monomer of formula CH2 = C (CH3) -COOR'2 in which R'2 represents a C4-C12 cycloalkyl group, preferably methacrylate of isobornyl, and / or - the second block is obtained from at least one monomer such as the homopolymer obtained at a Tg less than or equal to 20 ° C, and at least one monomer chosen from methacrylic acid and acrylic acid.

Advantageously, the block polymer according to the invention comprises from 50 to 800% by weight of methacrylate / isobornyl acrylate mixture, from 10 to 300% by weight of isobutyl acrylate and from 2 to 10% by weight of acrylic acid.

As indicated above, the intermediate segment, or intermediate sequence, which connects the first block and the second sequence of the block polymer can result from the polymerization of: i) at least one monomer of the first block, remaining available after the polymerization at a conversion rate of at most 900/0 to form the first block, ii) and at least one monomer of the second block, added to the reaction mixture. The formation of the second sequence is initiated when the monomers of the first sequence no longer react or become incorporated in the polymeric chain either because they are all consumed or because their reactivity no longer allows them to be used. to be. Thus the intermediate segment comprises the monomers of the first available sequence, resulting from a conversion rate of these first monomers less than or equal to 900/0, during the introduction of the monomers of the second block during the synthesis of the polymer.

The intermediate segment of the sequenced polymer is a random polymer (may also be called a statistical sequence), i.e. it comprises a statistical distribution of at least one of the monomers of the first sequence and at least one of one of the monomers of the second sequence.

The ethylenic block polymer according to the invention is prepared in particular by free radical polymerization, according to techniques well known in this type of polymerization. The free radical polymerization is carried out in the presence of an initiator whose nature is adapted, in known manner, depending on the desired polymerization temperature and the polymerization solvent. In particular, the initiator may be chosen from peroxide-functional initiators, oxidation-reduction pairs, or other radical polymerization initiators known to those skilled in the art. In particular, as a peroxide-functional initiator, there may be mentioned, for example: peroxy esters, such as terbutylperoxyacetate, tert-butyl perbenzoate, tertbutylperoxy-2-ethylhexanoate (Trigonox 21S from Akzo Nobel), 2,5-bis (2-ethylhexanoylperoxy) -2,5-dimethylhexane (Trigonox 141 from Akzo Nobel); peroxydicarbonates, such as di-isopropylperoxydicarbonate; peroxycetones, such as methyl ethyl ketone peroxide; hydroperoxides, such as hydrogen peroxide (H2O2), terbutylhydroperoxide; diacyl peroxides, such as acetyl peroxide, benzoyl peroxide; dialkyl peroxides, such as di-tert-butyl peroxide; inorganic peroxides, such as potassium peroxodisulfate (K2S2O4). As an initiator in the form of a redox couple, mention may be made of the potassium thiosulfate + potassium peroxodisulphate pair, for example. According to a preferred embodiment, the initiator is chosen from organic peroxides comprising 8 to 30 carbon atoms. Preferably, the initiator used is 2,5-bis (2-ethylhexanoylperoxy) -2,5-dimethylhexane, especially sold under the reference Trigonoe 141 by Akzo Nobel. The block polymer used according to the invention is preferably prepared by free radical polymerization and not by controlled or living polymerization. In particular, the polymerization is carried out in the absence of control agents, and in particular in the absence of control agent conventionally used in the living or controlled polymerization processes such as nitroxides, alkoxyamines, dithioesters, dithiocarbamates, dithiocarbonates or xanthates, trithiocarbonates, copper catalysts, for example.

The sequenced polymer may be prepared by free radical polymerization, and in particular by a process comprising mixing, in the same reactor, a polymerization solvent, an initiator, at least one glass transition monomer greater than or equal to 40 ° C., less than a glass transition monomer less than or equal to 20 ° C according to the following sequence: - is poured into the reactor, a portion of the polymerization solvent and optionally part of the initiator and monomers of the first casting mixture which is heated to a reaction temperature of between 60 and 120 ° C, is then poured, in a first casting, said at least one monomer of Tg greater than or equal to 40 ° C and optionally a portion of the initiator that is allowed to react for a time T corresponding to a conversion rate of said monomers of 90% maximum, - then poured into the reactor, in a second casting, again of the polymerization initiator, at least one glass transition monomer less than or equal to 20 ° C, which is allowed to react for a period T 'at the end of which the degree of conversion of said monomers reaches a plateau, - the reaction mixture at room temperature.

Preferably, the copolymer may be prepared by free radical polymerization, in particular by a process consisting of mixing, in one and the same reactor, a polymerization solvent, an initiator, an acrylic acid monomer, at least one lower glass transition monomer or equal to 20 ° C, at least one acrylate monomer of formula CH2 = CH-OOOR2 in which R2 represents a C4-C12 cycloalkyl group, and at least one methacrylate monomer of formula CH2 = C (CH3) -COOR'2 in which R '2 represents a C4 to C12 cycloalkyl group, according to the following stage sequence: a portion of the polymerization solvent and optionally part of the initiator and monomers of the polymer are poured into the reactor; first casting, which mixture is heated to a reaction temperature between 60 and 120 ° C, is then poured, in a first casting, said acrylate of formula CH 2 = CH-OOOR 2 and said methacrylate of formula CH 2 = C ( CH3 ) -COOR'2 as monomers of Tg greater than or equal to 40 ° C, and optionally a part of the initiator which is allowed to react for a duration T corresponding to a conversion rate of said monomers of 90% maximum the acrylic acid monomer and at least one vitreous transition monomer less than or equal to 20 ° C. are then poured into the reactor, in a second casting, again from the polymerization initiator, and allowed to react. during a period T 'after which the conversion rate of said monomers reaches a plateau, - the reaction mixture is brought to room temperature.

By polymerization solvent is meant a solvent or a mixture of solvents. In particular, as a polymerization solvent that may be used, mention may be made of: ketones that are liquid at room temperature, such as methyl ethyl ketone, methyl-sobutyl ketone, diisobutyl ketone, isophorone, cyclohexanone or acetone; propylene glycol ethers which are liquid at ambient temperature, such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate or dipropylene glycol mono-butyl ether; esters having from 3 to 8 carbon atoms in total, such as ethyl acetate, methyl acetate, propyl acetate, n-butyl acetate, isopentyl acetate, ; ethers which are liquid at room temperature (25 ° C.), such as diethyl ether, dimethyl ether or dichlorodiethyl ether; alkanes which are liquid at ambient temperature, such as decane, heptane,--decane, isododecane, cyclohexane and isohexadecane; aromatic cyclic compounds which are liquid at ambient temperature, such as toluene and xylene; aldehydes which are liquid at ambient temperature, such as benzaldehyde and acetaldehyde, and mixtures thereof. The polymerization solvent may be chosen especially from ethyl acetate, butyl acetate, alcohols such as isopropanol, ethanol, aliphatic alkanes such as isododecane and mixtures thereof. Preferably, the polymerization solvent is a mixture of butyl acetate and isopropanol or isododecane.

As indicated above, the dispersion of ethylene polymer particles according to the invention is very preferably monodisperse, which means that it has a very low particle size polydispersity, in particular less than or equal to 0.15, preferably less than or equal to 0.1; In particular, particle size polydispersity (PDI) can 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, in particular between 100 and 1000 nm, in particular between 120 and 800 nm, preferably between 130 and 700 nm (determined by diffusion dynamic of light, using a Malvern Zetasizer Nano S90). Preferably, the dispersion according to the invention has a solids content of 5 to 400/0 by weight, especially 6 to 300/0 by weight, or even 7 to 250/0 by weight.

The dispersions obtained according to the invention can then be used in a cosmetic composition which moreover comprises a cosmetically acceptable medium. The dispersions may be present in the cosmetic compositions according to the invention in an amount of from 0.1 to 990 wt.%, Preferably from 5 to 980 wt.%, In particular from 10 to 950 wt.%, Even 50 to 900 wt. By weight, of dispersion relative to the total weight of the composition.

The composition may then comprise, according to the intended application, the usual constituents for this type of composition. Among these constituents, mention may be made of waxes, oils, gums and / or pasty fatty substances, of vegetable, animal, mineral or synthetic origin, or even silicone, and mixtures thereof. Among the waxes that may be present in the composition according to the invention, mention may be made, alone or as a mixture, of hydrocarbon-based waxes such as beeswax; Carnauba wax, Candellila wax, Ouricoury wax, Japan wax, cork fiber wax or sugar cane wax; paraffin waxes of lignite; microcrystalline waxes; lanolin wax; the wax of Montan; ozokerites; polyethylene waxes; waxes obtained by Fischer-Tropsch synthesis; hydrogenated oils, fatty esters and glycerides at 25 ° C. It is also possible to use silicone waxes, among which mention may be made of alkyls, alkoxys and / or polymethylsiloxane esters. The composition according to the invention may also comprise oils of mineral, animal, plant or synthetic origin, carbonated, hydrocarbon-based, fluorinated and / or silicone-based, alone or as a mixture insofar as they form a homogeneous and stable mixture and where they are compatible with the intended use. Among the oils that may be present in the composition according to the invention, mention may be made, alone or as a mixture, of hydrocarbon-based oils such as liquid paraffin or petroleum jelly; perhydrosqualene; arara oil; sweet almond oil, calophyllum, palm, castor oil, avocado, jojoba, olive or cereal sprouts; esters of lanolic acid, oleic acid, lauric acid, stearic acid; alcohols such as oleic alcohol, linoleic or linolenic alcohol, isostearyl alcohol or octyl dodecanol. Mention may also be made of silicoated oils such as PDMS, which may be phenylated, such as phenyltrimethicones. Volatile oils such as cyclotetradimethylsiloxane, cyclopentadimethylsiloxane, cyclohexadimethylsiloxane, methylhexyldimethylsiloxane, hexamethyldisiloxane or isoparaffins can also be used.

The composition according to the invention may also comprise one or more dyestuffs chosen from pulverulent compounds and / or liposoluble or water-soluble dyes. The pulverulent compounds may be chosen from pigments and / or nacres and / or fillers usually used in cosmetic or pharmaceutical compositions. Advantageously, the pulverulent compounds represent 0.1 to 50% of the total weight of the composition and better still 1 to 40%. The pigments may be white or colored, inorganic and / or organic, interferential or not. Among the inorganic pigments, mention may be made of titanium dioxide, optionally surface-treated, zirconium or cerium oxides, as well as iron or chromium oxides, manganese violet, ultramarine blue, hydrate of chrome and ferric blue. 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 with iron oxides, titanium mica with in particular ferric blue or chromium oxide, titanium mica with an organic pigment of the aforementioned type as well as pearlescent pigments based on bismuth oxychloride.

The fillers can be mineral or organic, lamellar or spherical. Mention may be made of talc, mica, silica, kaolin, powders of nylon and polyethylene, poly-R-alanine and polyethylene, Teflon, lauroyl-lysine, starch, boron nitride, tetrafluoroethylene polymer powders, hollow microspheres such as Expancel (Nobel Industrie), polytrap (Dow Corning) and silicone resin microspheres (Toshiba Tospearls, for example), precipitated calcium carbonate, magnesium carbonate and hydrocarbonate, hydroxyapatite, hollow silica microspheres (SILICA BEADS from MAPRECOS), glass or ceramic microcapsules, metallic soaps derived from organic carboxylic acids having from 8 to 22 atoms carbon, preferably from 12 to 18 carbon atoms, for example zinc stearate, magnesium or lithium, zinc Iaurate, magnesium myristate. Liposoluble dyes are, for example, Sudan Red, DC Red 17, DC Green 6, I3-carotene, soybean oil, Sudan Brown, DC Yellow, 11, DC Violet 2, DC Orange 5 , yellow quinoline. They may represent from 0 to 20% and in particular from 0.01 to 20% of the weight of the composition and better still from 0.1 to 6%. The water-soluble dyes are, for example, beet juice, methylene blue and may represent up to 6% of the total weight of the composition.

The composition may furthermore comprise any additive usually used in the cosmetics field, such as antioxidants, perfumes, essential oils, preservatives, cosmetic active ingredients, moisturizers, vitamins, essential fatty acids, ceramides, filters sunscreens, polymers, thickeners, gelling agents, surfactants. Of course, those skilled in the art will take care to choose this or these additives 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 addition envisaged.

The composition according to the invention may be in the form of a suspension, in particular a dispersion of oil in water by means of vesicles; an oily solution optionally thickened or gelled; an oil-in-water emulsion, water-oil, or multiple; a gel or a mousse; an oily or emulsified gel; a dispersion of vesicles, in particular lipids; a biphase or multiphase lotion; a spray; a lotion, a cream, an ointment, a soft paste, an ointment, a solid cast or molded and especially stick or cup, or compacted solid. 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 cosmetic composition according to the invention can be in the form of a care product and / or make-up of the skin of the body or of the face, the lips, the eyelashes, the nails, the hair or a solar product. or self-tanning, a hair product including for maintaining, shaping, cleaning, conditioning, coloring, straightening, hair. The compositions according to the invention can be used for washing or treating keratin materials such as hair, skin, eyelashes, eyebrows, nails, lips, scalp, hair.

The composition according to the invention finds a particularly interesting application in the field of make-up, more particularly the makeup of the lips, nails, eyelashes and / or face, as well as in the field of hair care and after-shampoos. It can therefore be advantageously in the form of makeup composition, including mascara, eyeliner, lipstick, blush, eyeshadow, foundation; of hair care composition of the hair and / or conditioner.

The subject of the invention is also a process for the cosmetic treatment of keratin materials, in particular the skin of the body or of the face, the lips, the eyelashes, the nails and / or the hair, comprising the application on the said materials of a cosmetic composition as defined above.

This process allows the makeup of the skin, lips, eyelashes, nails and / or hair.

The invention is illustrated in more detail in the following examples. Example 1 Synthesis of the Stabilizer The desired stabilizer is a block polymer of poly (isobornyl acrylate / isobornyl methacrylate / isobutyl acrylate / acrylic acid).

It is synthesized as follows: 300 g of isododecane are introduced into a 1 liter reactor and then heated to 25 ° C to 90 ° C in 1 hour. 105 g of isobornyl methacrylate, 105 g of isobornyl acrylate and 1.8 g of 2,5-bis (2-ethylhexanoylperoxy) -2,5-dimethylhexane are added at 90 ° C. and over 1 hour. (Trigonox® 141 from Akzo Nobel). The mixture is maintained at 90 ° C. for 1 h 30 min. 75 g of isobutyl acrylate, 15 g of acrylic acid and 1.2 g of 2,5-bis (2-ethylhexanoylperoxy) -2,5-dimethylhexane are then introduced at 90 ° C. and over 30 minutes. . The mixture is kept at 90 ° C. for 3 hours, then the mixture is cooled. A 50% solution of active polymer material in solution in isododecane is obtained. EXAMPLE 2 Preparation of a Dispersion According to the Invention A dispersion of poly (methyl methacrylate) stabilized with the block polymer prepared in Example 1 is prepared

25 g of isododecane, 103.5 g of heptane, 27 g of methyl methacrylate, 26.7 g of block polymer prepared in Example 1 and 50.7% are charged into a 1-liter reactor. in isododecane and 1.35 g of tertbutyl-2-peroxyethyl hexanoate (Trigonox 21S Akzo Nobel). The mixture is stirred and the temperature is raised to 25 ° C. to 90 ° C. in 1 hour. Bleaching is noted at around 90 ° C. The temperature of the reaction medium is maintained at 90 ° C. Once 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 of rigid polymer particles (Tg = 100 ° C.) at 19.8% dry matter in isododecane is obtained.

Dp: average diameter determined by dynamic light scattering and its polydispersity index Q. (Malvern Zetasizer Nano S90, monodisperse dispersion from 40 Ω <0.1); Dp: 253 nm (Q = 0.14) Color effect observed on a wet 10 μm film, made on a Leneta contrast map from the dispersion in isododecane; the deposit is left for 24 hours at 25 ° C. for drying, before observation. A gray-white effect is observed.

Example 3 Mascara A mascara is prepared having the following composition: Modified hectorite (Bentone® 38V from Elementis) 2 g pigments 2 g Dispersion of Example 2 (at 200/0 MS) 75 g (ie 15 g MS) Isododecane qsp 100 g * MS: dry matter The mascara, after application on the eyelashes, is considered very satisfactory.

EXAMPLE 4 Lipstick Stick The following lipstick composition (% by weight) is prepared: polyethylene wax 30/0 dispersion of Example 2 (at 200/0 MS) 650/0 (ie 130%) / 0 MS) - Isododecane qs 1000/0 The composition obtained after application to the lips has good cosmetic properties.

Example 5 Lip Gloss A gloss having the following composition (% by weight) is prepared: Dispersion of Example 2 (at 200/0 DM) 250/0 (ie 50/0 MS) - Parléam qs 1000 / The composition obtained after application to the lips has good cosmetic properties.

Example 6: W / O foundation A foundation composition is prepared comprising the following compounds: Phase A cetyl dimethicone copolyol (ABIL EM 90 from Goldschmidt) 30 / o Isostearyl diglyceryl succinate (IMWITOR 780K from Condea) 0, 60/0 Pigments (hydrophobic iron and titanium oxides) Io / o Dispersion of Example 2 (at 200/0 MS) 6.50 / 0 (ie 1.30 / 0 MS) Isododecane qs 1000/0 (on phase A) Phase 8 Magnesium sulphate 0.70 / 0 Preservative qs Water qs 1000/0 (on phase B) The composition obtained has good cosmetic properties.

EXAMPLE 7 Nail Polish A nail polish having the following composition is prepared: Dispersion of Example 2 (at 200/0 MS) 20 g (ie 4 g MS) 23 - Butyl acetate 25 g - Isopropanol 11 g - Hexylene Glycol 2.5 g - pigment 1 g - modified Hectorite (Bentone® 27V from Elementis) 1.3 g - ethyl acetate qs 100 g Example 8: 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 2 (at 200/0 MS) 25 g (ie 5 g MS) Composition 8: Iron oxides 2 g Vaseline 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 the mixture is milled for about 2 minutes. 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 9: qel for visaqe The following composition is prepared: 10 g - isopropyl palmitate - modified hectorite 0.15 g - oxyethylenated sorbitan septaoleate (400E) 5 g Example 10: care oil The following composition is prepared: g (12.8 g MS) - Dispersion of Example 2 (at 200/0 MS) - Jojoba oil 10 g - Soybean oil 10 g After application to the nails, this varnish was judged to be very good cosmetic properties. Dispersion of Example 2 (at 200/0 MS) 46.25 g (9.25 g MS) - Parléam qs 100 g A gel having good cosmetic properties is obtained.

A care oil is obtained which can be applied to the body or face.

Claims (10)

REVENDICATIONS1. Cosmetic composition comprising, in a cosmetically acceptable medium, a dispersion, in a non-aqueous medium, of ethylene polymer particles stabilized on the surface by a stabilizer, said stabilized ethylenic polymer being rigid, and said stabilizer being chosen from ethylenic polymers sequencers comprising at least a first sequence and at least a second sequence, said first and second sequences being interconnected by an intermediate segment comprising at least one constituent monomer of said first block and at least one constituent monomer of said second block. 2. Cosmetic composition according to claim 1, wherein the rigid ethylene polymer is obtained by polymerization of monomers, alone or as a mixture, chosen in such a way that the glass transition temperature (Tg) of the resulting ethylenic polymer is greater or equal to 20 ° C. 3. Cosmetic composition according to claim 2, in which the rigid ethylene polymer is obtained by polymerization of 60 to 99.90% by weight, relative to the total weight of monomers, of monomers with a Tg greater than or equal to 20 °. C, in particular 80-950 / 0 by weight of monomers with a Tg greater than or equal to 20 ° C .; preferably, 1000/0 by weight of the monomers capable of forming the polymer in dispersion are of Tg greater than or equal to 20 ° C. 4. Cosmetic composition according to claim 1, wherein the rigid ethylenic polymer is obtained by polymerization of monomers, alone or in mixture, in the presence of at least one crosslinking agent. Cosmetic composition according to claim 4, wherein the crosslinking agent is present in an amount of 1 to 250% by weight, preferably 2 to 200% by weight, and more preferably 5 to 150% by weight, relative to the total weight of monomers. 6. Cosmetic composition according to one of claims 4 to 5, wherein the crosslinking agent is selected from, alone or in 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. 7. Cosmetic composition according to one of the preceding claims, wherein the rigid ethylenic polymer is a linear random copolymer. 8. Cosmetic composition according to one of the preceding claims, in which the monomers employed to prepare the dispersed ethylenic polymer are chosen from, alone or as a mixture,: the esters of (meth) acrylic acid; C1-C18, and especially methyl, ethyl, propyl, n-butyl, isobutyl, 2-ethylhexyl, tert-butyl, isooctyl, decyl, myristyl, stearyl (meth) acrylates; , isobornyl; styrene, ethylhexylvinylether, dodecylvinylether, vinyl hexanoate; acrylic acid and methacrylic acid; maleic anhydride. 9. Cosmetic composition according to one of the preceding claims, in which the non-aqueous medium consists of at least one non-aqueous compound, liquid at 25 ° C, having an overall solubility parameter according to the solubility space of HANSEN less than or equal to 20 (MPa) 1/2, or a mixture of such compounds. 10. Cosmetic composition according to one of the preceding claims, in which the non-aqueous medium comprises, alone or in mixture: volatile silicone oils, especially cyclic or linear, such as cyclodimethylsiloxanes and linear dimethylsiloxanes; esters of formula RCOOR 'in which R represents the residue of a higher fatty acid containing from 7 to 19 carbon atoms and R' represents a hydrocarbon-based chain containing from 3 to 20 carbon atoms, such as palmitates and adipates; myristates and benzoates, especially diisopropyl adipate and isopropyl myristate; - linear or branched C8-C60 alkanes, volatile or non-volatile; cyclic, non-aromatic, C 5 -C 12 alkanes; volatile or non-volatile; aliphatic fatty monoalcohols having 12 to 30 carbon atoms, the hydrocarbon chain having no substitution group. 16. Cosmetic composition according to one of the preceding claims, in which the stabilizer is present in a proportion of 0.1 to 200/0 by weight relative to the weight of the rigid ethylenic polymer, preferably 2 to 180/0 by weight. preferably 5 to 170/0 by weight, or even 8 to 160/0 by weight. 17. Cosmetic composition according to one of the preceding claims, in which the stabilizing ethylenic block polymer comprises at least a first block having a glass transition temperature greater than or equal to 40 ° C and at least a second block having a temperature of vitreous transition less than or equal to 20 ° C, said first sequence and said second sequence being interconnected by an intermediate segment, preferably a random segment, comprising at least a first constituent monomer of said first block and at least a second constituent monomer of the second sequence, different from said first monomer. 13. Cosmetic composition according to one of the preceding claims, in which the stabilizing ethylenic block polymer has a polydispersity index Ip greater than 2, especially between 2 and 9, preferably between 2.5 and 8, better understood between 2.8 and 6. 14. Cosmetic composition according to one of the preceding claims, in which the stabilizing ethylenic block polymer is such that: the first block is obtained from at least one monomer of formula CH 2 = CH In which R 2 represents a C 4 to C 12 cycloalkyl group, preferably isobornyl acrylate, and at least one monomer of formula CH 2 = C (CH 3) -COOR '2 in which R' 2 represents a group C4 to C12 cycloalkyl, preferably isobornyl methacrylate, and / or - the second block is obtained from at least one monomer such as the homopolymer obtained at a Tg of less than or equal to 20 ° C., and at least one monomer selected from ac methacrylic ide and acrylic acid. 15. Composition according to one of the preceding claims, being in the form of a care product and / or make-up of the skin of the body or face, lips, eyelashes, nails, hair, hair. a sunscreen or self-tanning product, a hair product especially for the maintenance, shaping, cleaning, conditioning, coloring, straightening, hair. 16. Process for the cosmetic treatment of keratinous substances, in particular the skin of the body or face, lips, eyelashes, nails and / or hair, comprising the application to said materials of a cosmetic composition as defined in one of claims 1 to 15. 2730