FR2821744A1 - Cosmetic treatment for wrinkled skin, comprises applying a skin-tautening composition comprising polymer particles dispersed in a liquid fat phase - Google Patents

Abstract

The present invention relates to the cosmetic use of a dispersion of polymer particles in a liquid fatty phase, as a tightening agent, and to the cosmetic use of a composition for topical application containing such a dispersion, for blurring and / or erase wrinkles and / or fine lines of the skin by a tightening effect. The polymers constituting the particles in dispersion which can be used in the composition of the invention preferably have a molecular weight of the order of 2000 to 10,000,000 and a Tg greater than 40 ° C., and they are preferably chosen from homopolymers or radical, acrylic or vinyl copolymers, and mixtures thereof.

Description

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The present invention relates to the cosmetic use of a dispersion of polymer particles in a liquid fatty phase, as tensioning agent, and to the cosmetic use of such a composition, for reducing and / or erasing wrinkles and / or or the fine lines of the skin by a tightening effect and / or tighten the skin.

The aging process of the skin is accompanied by a gradual change in the structure and functions of the skin. The main clinical signs of skin aging are the appearance of wrinkles and fine lines that increase with age. It is known to remedy these signs of aging by using cosmetic or dermatological compositions containing active principles such as α-hydroxy acids, (3-hydroxy-acids and retinoids, these molecules act on wrinkles, for example by eliminating dead cells and accelerating the cell renewal process.

However, the visible effect of these compositions occurs only after a certain time of application, ranging from a few days to several weeks.

However, we seek more and more to obtain an immediate effect, leading quickly to a smoothing of wrinkles and / or fine lines and the disappearance, even temporary, marks of fatigue. In particular, it has been proposed to use so-called "tensor" agents which, by a tensioning effect of the superficial layer of the skin, are capable of smoothing the skin by reducing the number and the depth of the wrinkles and fine lines, and of to remove the marks of fatigue, and this almost instantaneously.

These "tensing agents" may be in particular polymers of natural or synthetic origin in aqueous dispersion, capable of forming a film causing shrinkage of the stratum corneum, the superficial horny layer of the epidermis.

The cosmetic or dermatological use of such polymeric systems for attenuating the effects of aging of the skin is described in patent applications FR-A-2,758, 083, FR-A-2,758, 084 and EP-A-1,038,519.

These tensor polymer systems, although very effective and fast, sometimes cause some discomfort to some users, especially those with fragile skin. These tensing agents form indeed on the skin a relatively rigid film and not very flexible.

The Applicant has found, surprisingly and unexpectedly, that the use of a dispersion of polymer particles in a liquid fatty phase makes it possible to obtain a composition that can be applied to the skin and gives an immediate tightening effect to the skin. wrinkles and / or wrinkles already formed. The fact of using a dispersion in a fatty phase gives a greater comfort of application.

The polymer dispersions used in the present invention constitute particularly effective tensing agents. Tensor is understood to mean compounds that may have a tightening effect, that is to say, that can reseal the skin and, by this tensioning effect, smooth the skin and reduce or even

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disparaître de façon immédiate les rides et les ridules, et donner ainsi un coup d'éclat à la peau.

disappear immediately wrinkles and fine lines, and give a boost to the skin.

Admittedly, it is described in EP-A-749746 that dispersions of polymer particles in a fatty phase can camouflage the fine lines of the skin. However, it is not described that these dispersions can have a tensor effect, since the effect observed on the fine lines is an effect of camouflage improvement provided by the powdery compounds also present in the composition, the particles of polymer entering the interior of the fine lines and camouflaging them by filling the wrinkles, which is quite different from a tensor effect. In addition, the polymers described in this document can be film-forming or non-film-forming, whereas the polymers that can be used in the present application are non-film-forming. Non-film-forming polymer is understood to mean a polymer which is incapable of forming, on its own, an isolatable film, that is to say a polymer which remains in the form of particles when the dispersion is applied to the skin.

The subject of the invention is therefore the cosmetic use of at least one dispersion of polymer particles in a liquid fatty phase, as a skin tightening agent.

The subject of the invention is also the cosmetic use of a cosmetic composition containing at least one dispersion of polymer particles in a liquid fatty phase, for retightening the skin and / or blurring the wrinkles or fine lines of the skin by a tensor effect, and / or give a boost to the skin.

In a preferred embodiment of the invention, a dispersion of polymer particles in a liquid fatty phase is used, making it possible to obtain a film having an isolated stratum corneum shrinkage, greater than about 0.5%, of preferably greater than or equal to 1%, measured with the aid of an extensometer, at 30 ° C., under a relative humidity of 40%, for a concentration of 7% by weight of polymer solids in a solvent such as isoparaffin such as isododecane or ISOPAR, isoparaffin mixtures.

The method of measuring the retraction of the isolated stratum comeum is hereinafter described in the examples.

dispersion de particules de polymère dans une phase grasse liquide, pour obtenir un film donnant une rétraction du stratum corneum isolé, supérieure à environ 1%, mesurée à l'aide d'un extensomètre, à 30 C, sous une humidité relative de 40%, pour une concentration de 7 % en poids de matière sèche de polymère dans un solvant. Also, the invention also relates to the cosmetic use of at least one

dispersion of polymer particles in a liquid fatty phase, to obtain a film giving an isolated stratum corneum shrinkage, greater than about 1%, measured using an extensometer, at 30 C under a relative humidity of 40% at a concentration of 7% by weight of polymer solids in a solvent.

Another object of the invention is a method of cosmetic treatment of a wrinkled skin consisting in applying thereto a cosmetic composition containing at least one dispersion of polymer particles in a liquid fatty phase, in an amount effective for blurring immediately the wrinkle or the wrinkle

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 by tensor effect and / or to tighten the skin. By an immediate effect is meant that occurs within 15 to 30 minutes after application of the composition.

An effective amount is called here an amount sufficient to achieve the desired result, that is to say the smoothing of wrinkles and fine lines by tensor effect. This amount corresponds to a quantity of polymer in dry matter, as indicated below.

application, les rides et les ridules à la surface de la peau. Elle permet aussi de retendre la peau, par exemple en vue de redessiner l'ovale du visage. Elle peut notamment être appliquée sur le visage et/ou sur le cou, notamment sur le décolleté. The composition used according to the invention is easily applied to the skin and spreads easily there. It allows by tensor effect, to fade immediately after

application, wrinkles and fine lines on the surface of the skin. It also makes it possible to retighten the skin, for example in order to redraw the oval of the face. It can in particular be applied to the face and / or the neck, especially on the neckline.

The cosmetic composition according to the invention intended for topical application contains a physiologically acceptable medium. The term "physiologically acceptable medium" means a medium that is compatible with all keratin materials such as the skin, including the scalp, the nails, the mucous membranes, the eyes and the hair, or any other cutaneous zone of the body.

Furthermore, by liquid fatty phase is meant a phase immiscible with water, comprising fatty substances such as oils, fatty acids, fatty alcohols, waxes, resins and gums. This fatty phase is liquid, that is to say that it is in the liquid state at ambient pressure (about 760 mm Hg) and at room temperature (20 to 30 C). It usually contains at least one oil.

Polymers in Dispersion One or more dispersions of particles of one or more polymers may be used according to the invention in a physiologically acceptable liquid fatty phase. These polymer particles are generally spherical. These particles may in particular be in the form of nanoparticles of stable dispersion polymer in said fatty phase. The nanoparticles are preferably of a number average size ranging from 5 to 600 nm. It is possible, however, to obtain polymer particle sizes of up to 1 μm.

The particles may be formed of one or more polymers, said polymer being itself obtainable from a single type of monomer (homopolymer) or from several types of polymers (copolymer).

la norme ASTM D3418-97. The dispersion polymers that can be used in the composition of the invention preferably have an average molecular weight of the order of 2,000 to 10,000,000, and a glass transition temperature (Tg) of greater than 40 ° C. and preferably of 40 to 200 C and better from 450 to 1500C. The measurement of Tg (glass transition temperature) is performed by DSC (Differential Scanning Calorimetry) according to

ASTM D3418-97.

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 When the polymer has a glass transition temperature that is too high for the desired application, a plasticizer can be associated with it so as to obtain an appropriate glass transition temperature with the mixture used.

The plasticizer may be chosen from plasticizers usually used in the cosmetics field, and especially from compounds that may be solvents of the polymer.

non volatil du type huile, de former un dépôt continu sur la peau et/ou les lèvres, le composé non volatil reliant entre elles les particules de polymère. The polymers that can be used in the composition of the invention are non-film-forming polymers, that is to say polymers that are not capable of forming, on their own, an isolatable film. These polymers allow, in combination with a compound

nonvolatile oil type, to form a continuous deposit on the skin and / or lips, the non-volatile compound interconnecting the polymer particles.

As polymers that may be used in the composition of the invention, homopolymers or radical copolymers, vinylic or acrylic, optionally crosslinked may be mentioned, preferably having a Tg greater than 40 ° C. and in particular ranging from 45 ° to 150 ° C., used alone or as a mixture. .

Radical polymer is understood to mean a polymer obtained by polymerization of unsaturated monomers, in particular ethylenic monomers, each monomer being capable of homopolymerizing (unlike polycondensates). The radical polymers may in particular be vinyl polymers, especially acrylic polymers. Polymers are understood to mean both homopolymers and copolymers.

The vinyl polymers may result from the polymerization of ethylenically unsaturated monomers having at least one acidic group and / or esters of these acidic monomers and / or amides of these acids.

As the acid group-bearing monomer, α, β-ethylenic unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid may be used. It is preferable to use (meth) acrylic acid (acrylic or methacrylic acid) and crotonic acid, and more preferably (meth) acrylic acid.

d'alkyle, on peut citer les (méth) acrylates de méthyle, d'éthyle, de butyle, d'isobutyle, d'éthyl-2 hexyle et de lauryl. Comme (méth) acrylates d'hydroxyalkyle, on peut citer le (méth) acrylate d'hydroxyéthyle, le (méth) acrylate de 2hydroxypropyl. Comme (méth) acrylates d'aryle, on peut citer l'acrylate de benzyle ou de phényle. The acidic monomer esters are advantageously chosen from esters of (meth) acrylic acid (also called (meth) acrylates), such as alkyl (meth) acrylates, in particular C 1 -C 20 alkyl, preferably C1-C8, the (meth) acrylates of aryl, in particular of aryl in CS-C1o'les (meth) acrylates of hydroxyalkyl, in particular hydroxyalkyl C2-C6. As (meth) acrylates

alkyl, mention may be made of (meth) acrylates of methyl, ethyl, butyl, isobutyl, 2-ethylhexyl and lauryl. Hydroxyalkyl (meth) acrylates include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and the like. Aryl (meth) acrylates include benzyl or phenyl acrylate.

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 Particularly preferred (meth) acrylic acid esters are alkyl (meth) acrylates, more particularly those in which the alkyl radical has from 1 to 8 carbon atoms.

The radical polymer used is preferably copolymers of (meth) acrylic acid and alkyl (meth) acrylate, especially of (C 1 -C 4) alkyl. More preferably, it is possible to use methyl acrylates copolymerized with acrylic acid.

le N-éthyl acrylamide, le N-t-butyl acrylamide, le N-octyl acrylamide ; les N-dialkyl (C,-C4) (méth) acrylamides. As amides of the acidic monomers, mention may be made of (meth) acrylamides, and especially N-alkyl (meth) acrylamides, in particular C 2 -C 12 alkyl such as

N-ethyl acrylamide, Nt-butyl acrylamide, N-octyl acrylamide; N-dialkyl (C 1 -C 4) (meth) acrylamides.

The vinyl polymers can also result from the polymerization of ethylenically unsaturated monomers having at least one amine group, in free form or partially or completely neutralized, or even partially or totally quaternized. Such monomers may be, for example, dimethylaminoethyl (meth) acrylate, dimethylaminoethyl methacrylamide, vinylamine, vinylpyridine or diallyldimethylammonium chloride.

vinyle, le pivalate de vinyle, le benzoate de vinyle et le t-butylbenzoate de vinyle. The vinyl polymers may also result from the homopolymerization or copolymerization of at least one monomer chosen from vinyl esters and styrenic monomers. In particular, these monomers can be polymerized with acidic monomers and / or their esters and / or their amides, such as those mentioned above. Examples of vinyl esters that may be mentioned are vinyl acetate, vinyl propionate, sodium neodecanoate and

vinyl, vinyl pivalate, vinyl benzoate and vinyl t-butylbenzoate.

Examples of styrenic monomers include styrene and alphamethyl styrene.

The list of monomers given here is not limiting and it is possible to use any monomer known to those skilled in the art falling into the categories of acrylic and vinyl monomers (including monomers modified with a silicone chain).

- la N-vinylpyrrolidone, la vinylcaprolactame, les vinyl-N-alkyl (C,-C6) pyrroles, les vinyl-oxazoles, les vinyl-thiazoles, les vinylpyrimidines, les vinylimidazoles, - les oléfines tels que l'éthylène, le propylène, le butylène, l'isoprène, le butadiène. Le polymère vinylique peut être réticulé à l'aide d'un ou plusieurs monomères difonctionnels, notamment ceux comprenant au moins deux insaturations éthyléniques, tel que le diméthacrylate d'éthylène glycol ou le phtalate de diallyl. Other vinyl monomers that can be used include:

N-vinylpyrrolidone, vinylcaprolactam, vinyl-N-alkyl (C 1 -C 6) pyrroles, vinyl-oxazoles, vinyl-thiazoles, vinylpyrimidines, vinylimidazoles, olefins such as ethylene, propylene , butylene, isoprene, butadiene. The vinyl polymer may be crosslinked with one or more difunctional monomers, especially those comprising at least two ethylenic unsaturations, such as ethylene glycol dimethacrylate or diallyl phthalate.

The polymer dispersion can be manufactured according to the process described in EP-A-749746 (cited herein by reference). The polymerization can be

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effectuée en dispersion, c'est-à-dire par précipitation du polymère en cours de formation, avec protection éventuelle des particules formées par un stabilisant.

carried out in dispersion, that is to say by precipitation of the polymer being formed, with possible protection of the particles formed by a stabilizer.

The process then consists in preparing a mixture comprising the initial monomers as well as a radical initiator. This mixture is dissolved in a solvent called "synthetic solvent" in the following description. When the fatty phase is a non-volatile oil, the polymerization can be carried out in an apolare organic solvent (synthetic solvent), then the non-volatile oil (which must be miscible with the said synthesis solvent) is added and the synthesis solvent is selectively distilled off. .

choisir le solvant de synthèse parmi les huiles volatiles telles que les alcanes comme l'heptane, le cyclohexan, les isoalcanes appelées aussi isoparaffines comme l'isododécane, l'isodécane, l'isohexadécane et par exemple les huiles vendues sous les noms commerciaux Isopar ou Permetyl , les esters ramifiés en Cg-Ce comme le néopentanoate d'isohexyle, et leurs mélanges. On peut utiliser notamment les mélanges d'isoparaffines commercialisés par la société Exxon Chemicals sous les dénominations ISOPAR, et notamment le

mélange en à ,3, commercialisé sous la dénomination ISOPAR L (nom CTFA : Cii-13 Isoparaffin). A synthesis solvent is chosen such that the initial monomers and the radical initiator are soluble therein, and that the polymer particles obtained are insoluble so that they precipitate during their formation. In particular, one can

choose the synthesis solvent from volatile oils such as alkanes such as heptane, cyclohexane, isoalkanes also called isoparaffins such as isododecane, isodecane, isohexadecane and for example the oils sold under the trade names Isopar or Permetyl, Cg-Ce branched esters such as isohexyl neopentanoate, and mixtures thereof. It is possible in particular to use the isoparaffin mixtures marketed by Exxon Chemicals under the names ISOPAR, and especially the

mixture in 3, marketed under the name ISOPAR L (CTFA name: Cii-13 Isoparaffin).

According to a particular embodiment of the invention, the polymerization can be carried out directly in a volatile oil forming part of the liquid fatty phase, this volatile oil thus also playing the role of synthesis solvent. The monomers must also be soluble there, as well as the radical initiator, and the polymer obtained must be insoluble. According to this method, the polymer particles are prepared in the liquid fatty phase comprising one or more volatile cosmetic oils at ambient temperature (approximately 20 to 25 ° C.). These volatile oils are favorable to obtaining a deposit of good behavior. After evaporation of these oils, a continuous, flexible, non-sticky deposit is obtained on the skin. These volatile oils also facilitate the application of the composition to the skin. They may be hydrocarbon, silicone or fluorinated and may optionally comprise alkyl or alkoxy groups, pendant or at the end of the silicone chain.

The monomers are preferably present in the synthesis solvent, before polymerization, in a proportion of 5 to 20% by weight of the reaction mixture. All of the monomers may be present in the solvent before the start of the reaction, or the monomers or some of the monomers may be added as the polymerization reaction progresses.

The radical initiator may be in particular azobisisobutyronitrile or tert-butylperoxy-2-ethylhexanoate.

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 According to a preferred embodiment of the invention, the synthesis solvent is a volatile oil chosen from the isoparaffins indicated above.

ajout direct du polymère séquencé, polymère greffé et/ou polymère statistique, lors de la polymérisation. Stabilizer Preferably, the polymer particles are stabilized at the surface, as the polymerization progresses, thanks to a stabilizer which may be a block polymer, a graft polymer and / or a random polymer, alone or as a mixture. Stabilization can be carried out by any known means, and in particular by

direct addition of the sequenced polymer, graft polymer and / or random polymer during the polymerization.

The stabilizer is preferably also present in the mixture before polymerization. However, it is also possible to add it continuously, in particular when the monomers are also added continuously.

About 2 to 30% by weight of stabilizer based on the weight of the initial monomer mixture can be used, and preferably 5 to 20% by weight.

When a grafted and / or sequenced polymer is used as a stabilizer, the synthesis solvent is chosen such that at least a part of the grafts or sequences of said stabilizing polymer is soluble in said solvent, the other part of the grafts or sequences not being soluble therein. The stabilizing polymer used in the polymerization must be soluble or dispersible in the synthesis solvent. In addition, a stabilizer whose insoluble sequences or grafts have a certain affinity for the polymer formed during the polymerization is preferably chosen.

Among the graft polymers that can be used as stabilizers, mention may be made of silicone polymers grafted with a hydrocarbon chain and hydrocarbon polymers grafted with a silicone chain. Also suitable are graft copolymers having, for example, an insoluble polyacrylic backbone with soluble grafts of the pol-12- (hydroxystearic acid) type.

Thus, it is possible to use as stabilizer one or more grafted or sequenced block copolymers comprising at least one block of polyorganosiloxane type and at least one block of a radical polymer, such as graft copolymers of acrylic / silicone type which can be used especially when the non-aqueous medium is silicone.

It is also possible to use block or graft block copolymers comprising at least one polyorganosiloxane type block and at least one polyether block. The polyorganopolysiloxane block may in particular be a polydimethylsiloxane or else a poly (C2-C8) alkylsiloxane alkyl; the polyether block may be a C2-C18 polyalkylene, in particular polyoxyethylene and / or polyoxypropylene. In particular, it is possible to use dimethicones copolyol or alkyl (C2-Cg) dimethicone copolyols such as those sold under the names Dow Corning 3225C and Dow Corning 5225C by the company Dow Corning, lauryl

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 meticone copolyols such as the product sold under the name Dow Corning Q2-5200 by Dow Corning.

As graft or block block copolymers, mention may also be made of those comprising at least one block resulting from the polymerization of at least one ethylenic monomer comprising one or more optionally conjugated ethylenic bonds, such as ethylene or dienes such as butadiene and isoprene, and at least one block of a vinyl polymer and better styrenic. When the ethylenic monomer comprises several optionally conjugated ethylenic bonds, the residual ethylenic unsaturations after the polymerization are generally hydrogenated.

tels que les copolymères vendus sous le nom de Kraton par la société Shell Chemical Co. 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. Among these polymers, mention may be made of block copolymers, in particular of the "diblock" or "triblock" type of the polystyrene / polyisoprene (SI), polystyrene / polybutadiene (SB) type, such as those sold under the name LUVITOL HSB by the company BASF styrene / butadiene / styrene (SBS), styrene / copoly (ethylene-propylene) (SEP), styrene / copoly (ethylene-butylene) (SEB) or styrene / copoly (ethylene-butylene) type styrene (SEBS),

such as the copolymers sold under the name Kraton by Shell Chemical Co.

In particular, Kraton G1650 (SEBS), Kraton G1651 (SEBS), Kraton G1652 (SEBS), Kraton G1657X (SEBS), Kraton G1701X (SEP), Kraton G1702X (SEP), Kraton can be used. G1726X (SEB), Kraton D-1101 (SBS), Kraton D-1102 (SBS), Kraton D-1107 (SIS). The polymers are generally called copolymers of hydrogenated dienes or not.

(copolymère styrène/méthacrylate). Comme copolymères blocs greffés ou séquencés comprenant au moins un bloc résultant de la polymérisation d'au moins un monomère éthylénique à une ou plusieurs liaisons éthyléniques et d'au moins un bloc d'un polymère acrylique, on peut citer les copolymères bi-ou tri-séquences poly (méthylacrylate de méthyle)/polyisobutylène ou les copolymères greffés à squelette poly (méthylacrylate de méthyle) et à greffons polyisobutylène. It is also possible to use the products sold under the names Gelled Permethyl 99A-750.99A-753-59 and 99A-753-58 (mixture of triblock and star polymer) by the company Presperse; under the name Versagel 5960 by the company Penreco (triblock + star polymer); under the names OS129880, OS129881 and OS84383 by the company Lubrizol

(styrene / methacrylate copolymer). As grafted or sequenced block copolymers comprising at least one block resulting from the polymerization of at least one ethylenic monomer with one or more ethylenic bonds and at least one block of an acrylic polymer, mention may be made of the bi-or tri-copolymers poly (methyl methyl acrylate) / polyisobutylene or poly (methyl methyl acrylate) backbone graft copolymers and polyisobutylene graft copolymers.

polyalkylène en C-Cg (potyéthyténé et/ou potyoxypropyténé notamment), on peut As graft or block block copolymers comprising at least one block resulting from the polymerization of at least one ethylenic monomer with one or more ethylenic bonds and at least one block of a polyether such as a

poly (C 3 -C 6) polyalkylene (potyethylenated and / or potyoxypropytene in particular), it is possible to

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citer les copolymères bi-ou tri-séquencés polyoxyéthylène/polybutadiène ou polyoxyéthylène/polyisobutylène.

mention polyoxyethylene / polybutadiene or polyoxyethylene / polyisobutylene bi- or tri-block copolymers.

When a random polymer is used as a stabilizer, it is chosen so that it has a sufficient quantity of groups making it soluble in the envisaged synthetic solvent.

d'alkyle, issus d'alcools en C1-C4, et d'acrylates ou de méthacrylates d'alkyle, issus d'a ! coo ! s en Cg-Cgo. On peut en particulier citer le copolymère méthacrylate de stéaryle/méthacrylate de méthyle. Lorsque le solvant de synthèse est apolare, il est préférable de choisir en tant que stabilisant, un polymère apportant une couverture des particules la plus complète possible, plusieurs chaînes de polymères stabilisants venant alors s'adsorber sur une particule de polymère obtenu par polymérisation. It is thus possible to use copolymers based on acrylates or methacrylates

alkyl, derived from C1-C4 alcohols, and alkyl acrylates or methacrylates, derived from a! coo! s in Cg-Cgo. In particular, mention may be made of stearyl methacrylate / methyl methacrylate copolymer. When the synthesis solvent is apolare, it is preferable to choose as a stabilizer, a polymer providing the most complete coverage of the particles possible, several stabilizing polymer 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.

Indeed, the sequences or grafts insoluble in the synthetic solvent provide a larger coverage on the surface of the particles.

polyéther ou d'un polyester comme les blocs polyoxypropyléné et/ou oxyéthyléné. When the liquid synthetic solvent comprises at least one silicone oil, the stabilizing agent is preferably chosen from the group consisting of graft or block 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.

- (b) les copolymères d'acrylates ou de méthacrylates d'alkyle issus d'alcools en C1-C4, et d'acrylates ou de méthacrylates d'alkyle issus d'alcools en Cg-Cgo ; c - (c) les copolymères blocs greffés ou séquencés comprenant au moins un bloc résultant de la polymérisation d'au moins un monomère éthylénique, à liaisons éthyléniques conjuguées et au moins un bloc d'un polymère vinylique ou acrylique ou d'un polyéther ou d'un polyester ; - ou leurs mélanges. When the liquid fatty phase does not comprise silicone oil, the stabilizing agent is preferably chosen from the group consisting of: (a) grafted or sequenced block copolymers comprising at least one block of polyorganosiloxane type and at least one block of a radical polymer or a polyether or a polyester;

(b) copolymers of alkyl acrylates or methacrylates derived from C 1 -C 4 alcohols, and of alkyl acrylates or methacrylates derived from C 8 -C 8 alcohols; c - (c) grafted or sequenced block copolymers comprising at least one block resulting from the polymerization of at least one ethylenic monomer, with conjugated ethylenic bonds and at least one block of a vinyl or acrylic polymer or a polyether or a polyester; - or their mixtures.

Preferably, there is used as stabilizing agent, a block polymer and in particular a block polymer comprising a styrenic block, such as a Kraton.

The polymer particles in oily (or oily) dispersion may represent (in dry matter or active material) from 0.1 to 40% of the total weight of the composition, preferably from 1 to 30% and better still from 2 to 20% of the total weight of the composition. total weight of

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la composition. Quand la dispersion contient un stabilisant, la quantité en matière sèche de la dispersion représente la quantité de polymère et celle de stabilisant.

the composition. When the dispersion contains a stabilizer, the amount of dry matter of the dispersion represents the amount of polymer and that of stabilizer.

Fatty phase The liquid fatty phase of the composition comprises at least one oil and may contain any physiologically acceptable oil, especially chosen from oils of mineral, animal, vegetable or synthetic origin, carbonaceous, hydrocarbon, fluorinated and / or silicone, alone or mixed as long as they form a homogeneous and stable mixture, and where they are compatible with the intended use.

 The term "hydrocarbon-based oil" means oils containing predominantly carbon atoms and hydrogen atoms and optionally ester, ether, fluoro, carboxylic acid and / or alcohol groups, in particular oils containing alkyl or alkenyl chains, such as alkanes or alkenes but also alkyl or alkenyl chain oils containing one or more ether, ester and / or carboxylic acid groups.

The liquid fatty phase preferably comprises at least one non-volatile oil, and better still at least one nonvolatile oil and at least one volatile oil, the latter being the synthesis solvent of the preparation of the polymer particles.

- les esters de synthèse, comme les huiles de formules R1COOR2 et R1OR2 dans laquelle R1 représente le reste d'un acide gras comportant de 7 à 40 atomes de carbone, et R2 représente une chaîne hydrocarbonée, ramifiée ou non, contenant de 3 à 40 atomes de carbone, comme par exemple l'huile de Purcellin (octanoate de cétostéaryle), l'isononanoate d'isononyle, le benzoate d'alcool es cd à Cl,, les octanoates, décanoates ou ricinoléates d'alcools ou de polyalcools, le myristate d'isopropyle, le palmitat d'isopropyle, le stéarate de butyle, le laurate d'hexyle, l'adipate de diisopropyl, le palmitate d'éthyl-2-hexyle, le stéarate d'octyl-2- dodécyle, l'érucate d'octyl-2-dodécyle, l'isostéarate d'isostéaryle le laurate de 2- Non-volatile oils that can be used in the composition of the invention include, for example: hydrocarbon-based oils of animal origin, such as mink oil, turtle oil, perhydrosqualene; hydrocarbon oils of plant origin, such as liquid triglycerides of fatty acids containing from 4 to 10 carbon atoms, for example triglycerides of heptanoic or octanoic acids, or else, for example, sweet almond, calophyllum, palm, sunflower, maize, soya, squash, grape seed, sesame, hazelnut, apricot, macadamia, arara, cotton, castor oil, alfalfa, blackcurrant, rosebush muscat, hazelnut, avocado, jojoba, olive or cereal sprouts (corn, wheat, barley, rye), triglycerides of caprylic / capric acids such as those sold by Stearineries Dubois or those sold under Miglyol names 810,812 and 818 by the company Dynamit Nobel, shea butter oil; esters and ethers of fatty acids and in particular of lanolic acid, oleic acid, lauric acid and stearic acid;

synthetic esters, such as the oils of formulas R1COOR2 and R1OR2 in which R1 represents the residue of a fatty acid containing from 7 to 40 carbon atoms, and R2 represents a hydrocarbon chain, branched or unbranched, containing from 3 to 40 carbon atoms, such as, for example, purcellin oil (cetostearyl octanoate), isononyl isononanoate, alcohol benzoate, and the octanoates, decanoates or ricinoleates of alcohols or polyalcohols, isopropyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, diisopropyl adipate, 2-ethylhexyl palmitate, octyl-2-dodecyl stearate, octyl-2-dodecyl erucate, isostearyl isostearate 2- laurate

<Desc / Clms Page number 11>

hexyl-décyle, le palmitat de 2-octyl-décyle, le myristate de 2-octyl-dodécyle, le succinate de 2-diéthyl-hexyle, le malate de diisostéaryle, le triisostéarate de glycérine ou de diglycérine ; les esters hydroxylés comme le lactate d'isostéaryle, le malate de di-isostéaryle, l'octylhydroxystéarate, l'hydroxystéarate d'octyldodécyle, le citrate de triisocétyle, les heptanoates, octanoates, décanoates d'alcools gras ; les esters de polyol, comme le dioctanoate de propylène glycol, le diheptanoate de néopentylglycol et le diisononanoate de diéthylèneglycol ; et les esters du pentaérythritol comme le tétraisostéarate de pentaérythrityle ; - les hydrocarbures linéaires ou ramifiés, d'origine minérale ou synthétique, non volatils, tels que l'huile de paraffine ou ses dérivés, l'huile de vaseline, les polydécènes, le polyisobutène hydrogéné tel que l'huile de parléam ; - les alcools gras ayant de 8 à 26 atomes de carbone, comme l'alcool cétylique,

t'atcoo ! stéaryfique et leur mélange (alcool cétylstéarylique), l'octyldodécanol, le 2- butyloctanol, le 2-hexyldécanol, le 2-undécylpentadécanol, l'alcool oléique ou l'alcool linoléique ; - les alcools gras alcoylés et notamment éthoxylés tels que l'oleth-12 ; - les huiles de silicone comme les polyméthylsiloxanes (PDMS) non volatiles à chaîne siliconée linéaire ou cyclique, liquides ou pâteux à température ambiante, notamment les polydiméthylsiloxanes comportant des groupements alkyle, alcoxy ou phényle, pendant ou en bout de chaîne siliconée, groupements ayant de 2 à 24 atomes de carbone ; les silicones phénylées comme les phényltriméthicones,

les phényldiméthicones, les phényltriméthylsiloxydiphényl-siloxanes, les diphényldiméthicones, les diphénylméthyldiphényl trisiloxanes, les 2-phényléthyltriméthylsiloxysilicates liquides, éventuellement substitués par des groupements aliphatiques et/ou aromatiques comme les groupes alkyle, alcoxy ou phényle, pendant et/ou en bout de chaîne siliconée, groupements ayant de 2 à 24 atomes de carbone et éventuellement fluorés, ou par des groupements fonctionnels tels que des groupements hydroxyle, thiol et/ou amine, les polysiloxanes modifiés par des acides gras, des alcools gras ou des polyoxyalkylènes ; les silicones fluorées

et les polyméthylphénylsiloxanes ; - leurs mélanges.

hexyl decyl, 2-octyl decyl palmitate, 2-octyl-dodecyl myristate, 2-diethylhexyl succinate, diisostearyl malate, glycerin or diglycerine triisostearate; hydroxylated esters such as isostearyl lactate, di-isostearyl malate, octyl hydroxystearate, octyldodecyl hydroxystearate, triisocetyl citrate, heptanoates, octanoates, decanoates of fatty alcohols; polyol esters, such as propylene glycol dioctanoate, neopentyl glycol diheptanoate and diethylene glycol diisononanoate; and pentaerythritol esters such as pentaerythrityl tetraisostearate; non-volatile linear or branched hydrocarbons of mineral or synthetic origin, such as paraffin oil or its derivatives, liquid petroleum jelly, polydecenes, hydrogenated polyisobutene such as parleam oil; fatty alcohols having from 8 to 26 carbon atoms, such as cetyl alcohol,

t'atcoo! stearyl and their mixture (cetylstearyl alcohol), octyldodecanol, 2-butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol, oleyl alcohol or linoleic alcohol; alkyl and especially ethoxylated fatty alcohols such as oleth-12; silicone oils such as non-volatile polymethylsiloxanes (PDMS) with a linear or cyclic silicone chain, which are liquid or pasty at room temperature, in particular polydimethylsiloxanes comprising alkyl, alkoxy or phenyl groups, during or at the end of the silicone chain, groups having 2 to 24 carbon atoms; phenyl silicones such as phenyltrimethicones,

phenyldimethicones, phenyltrimethylsiloxydiphenylsiloxanes, diphenyldimethicones, diphenylmethyldiphenyltrisiloxanes, liquid 2-phenylethyltrimethylsiloxysilicates, optionally substituted with aliphatic and / or aromatic groups such as alkyl, alkoxy or phenyl groups, during and / or at the end of the silicone chain, groups having from 2 to 24 carbon atoms and optionally fluorinated, or with functional groups such as hydroxyl, thiol and / or amine groups, polysiloxanes modified with fatty acids, fatty alcohols or polyoxyalkylenes; fluorinated silicones

and polymethylphenylsiloxanes; - their mixtures.

Preferably, the non-volatile oil is chosen from oils of plant origin, branched hydrocarbon oils and mixtures thereof. As an oil of vegetable origin, mention may in particular be made of apricot oil, and as branched hydrocarbon oil, mention may be made especially of Parleam oil.

hydrocarbonées volatiles, les huiles fluorées volatiles et leurs mélanges. Comme huiles siliconées volatiles utilisables dans l'invention, on peut citer par exemple les huiles de silicones linéaires ou cycliques ayant une viscosité à température ambiante inférieure à 8 cSt et ayant notamment comportant de 2 à 7 atomes de silicium, ces silicones comportant éventuellement des groupes alkyle ou alkoxy ayant de 1 à 10 atomes de carbone. Comme huiles de silicone volatiles utilisables dans l'invention, on peut citer notamment les cyclométhicones comme

l'octaméthylcyclotétrasiloxane, le décaméthylcyclopentasiloxane, le dodécaméthyl cyclohexasiloxane, l'heptaméthyl-hexyltrisiloxane, l'heptaméthyloctyl-trisiloxane, As volatile oils, mention may be made of volatile silicone oils, oils

volatile hydrocarbon compounds, volatile fluorinated oils and mixtures thereof. As volatile silicone oils that can be used in the invention, mention may be made, for example, of linear or cyclic silicone oils having a viscosity at room temperature of less than 8 cSt and having in particular having from 2 to 7 silicon atoms, these silicones possibly comprising groups alkyl or alkoxy having 1 to 10 carbon atoms. As volatile silicone oils that may be used in the invention, cyclomethicones such as

octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, heptamethylhexyltrisiloxane, heptamethyloctyltrisiloxane,

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l'hexaméthyl-disiloxane, l'octaméthyl trisiloxane, le décaméthyltétrasiloxane, le dodécaméthy-Ipentasiloxane, et leurs mélanges.

hexamethyl disiloxane, octamethyl trisiloxane, decamethyltetrasiloxane, dodecamethyl pentasiloxane, and mixtures thereof.

As volatile hydrocarbon oils that may be used in the composition of the invention, mention may be made, for example, of volatile hydrocarbon oils having 8 to 16 carbon atoms and mixtures thereof, and in particular C 8 -C 18 branched alkanes, such as the isoparaffins indicated above. and in particular the oils sold under the trade names Isopar or Permetyl, and mixtures thereof.

"MSX 4518"par la Société 3M et le nonafluoroéthoxyisobutane ; les dérivés de perfluoromorpholine, tels que la 4-trifluorométhyl perfluoromorpholine vendue sous la dénomination"PF 5052"par la Société 3M. As fluorinated oils, mention may be made of partially hydrocarbon-based and / or silicone-based fluorinated oils, such as those described in the document JP-A-2-295912. As fluorinated oils, mention may also be made of perfluoromethylcyclopentane and perfluor-1,3 dimethylcyclohexane, sold under the names "FLUTEC PC1" and "FLUTEC PC3" by BNFL Fluorochemicals; perfluoro-1,2-dimethylcyclobutane; perfluoroalkanes such as dodecafluoropentane and tetradecafluorohexane, sold under the names "PF 5050" and "PF 5060" by the 3M Company, or bromoperfluorooctyl sold under the name "Foralkyl #" by the company Atochem; nonafluoromethoxybutane sold under the name

"MSX 4518" by the Company 3M and nonafluoroethoxyisobutane; perfluoromorpholine derivatives, such as 4-trifluoromethyl perfluoromorpholine sold under the name "PF 5052" by the company 3M.

As indicated above, the volatile oil present in the composition is preferably used as a synthetic solvent, and it is preferably chosen from isoparaffins and mixtures thereof, such as the products marketed by Exxon Chemicals under the names ISOPAR. .

comme l'acide stéarique, l'acide laurique, l'acide palmitique et l'acide oléique ; des cires comme la lanolin, la cire d'abeille, la cire de Carnauba ou de Candellila, les cires de paraffine, de lignite ou les cires microcristallines, la cérésine ou l'ozokérite, des cires synthétiques comme les cires de polyéthylène, les cires de Fischer-Tropsch ; des gommes telles que les gommes de silicone (diméthiconol) ; des résines de silicone telles que la trifluorométhyl-C1-4-alkyidimethicone et la trifluoropropyl-dimethicone ; et des élastomères de silicone de préférence

réticulés comme les produits commercialisés sous les dénominations KSG par la société Shin-Etsu, sous les dénominations Trefil , BY29 ou EPSX par la société Dow Corning ou sous les dénominations Gransil par la société Grant Industrie. The composition used according to the invention may comprise, in addition to the oils indicated above, one or more fatty substances chosen from waxes, gums and / or pasty, hydrocarbon, silicone and / or fluorinated fats of plant origin, animal, mineral or synthetic, and mixtures thereof. There may be mentioned, for example, fatty acids containing from 8 to 30 carbon atoms,

such as stearic acid, lauric acid, palmitic acid and oleic acid; waxes such as lanolin, beeswax, carnauba or candellila wax, paraffin waxes, lignite waxes or microcrystalline waxes, ceresin or ozokerite, synthetic waxes such as polyethylene waxes, waxes Fischer-Tropsch; gums such as silicone gums (dimethiconol); silicone resins such as trifluoromethyl-C1-4-alkylidimethicone and trifluoropropyl dimethicone; and preferably silicone elastomers

crosslinked as the products sold under the names KSG by the company Shin-Etsu, under the names Trefil, BY29 or EPSX by Dow Corning or under the names Gransil by the company Grant Industry.

The entire liquid fatty phase of the composition, comprising the oils and other fatty substances, can represent, when the composition is anhydrous, from 60 to

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 99.9% of the total weight of the composition and preferably 70 to 98% by weight relative to the total weight of the composition. This fatty phase preferably contains at least one non-volatile oil and even more preferably several non-volatile oils. The amount of non-volatile oil (s) may range, for example, from 5 to 90% and better still from 10 to 80% of the total weight of the liquid fatty phase. As indicated above, this fatty phase contains more preferably at least one non-volatile oil and at least one volatile oil.

The composition comprising the dispersion of polymer particles used according to the invention may constitute an anhydrous composition or may also contain an aqueous phase and constitute an emulsion. Emulsion is here understood to mean mixing an aqueous phase and an oily phase, whether this mixture is made in the presence or absence of emulsifying agents.

According to a preferred embodiment of the invention, the composition used according to the invention is anhydrous.

- les esters d'acide carboxylique inférieurs en C1-C3 tels que l'acétate de méthyle, l'acétate d'éthyle. When present, the aqueous phase may comprise water and / or thermal water and / or spring water and / or mineral water and / or floral water. It may also comprise one or more physiologically acceptable organic solvents or a mixture of water and one or more physiologically acceptable organic solvents. Among these organic solvents include: - C 1 -C 6 alcohols such as ethanol, isopropanol, n-propanol - ethers such as dimethoxyethane; ketones such as acetone, methyl ethyl ketone;

lower C 1 -C 3 carboxylic acid esters such as methyl acetate and ethyl acetate.

When the composition comprises an aqueous phase, the pH is generally close to the pH of the skin, that is to say from about 4 to about 8, and preferably 5 to 6.5.

The oily phase of the emulsions comprises the dispersion of polymer particles in the liquid fatty phase, and may further comprise oils and other fatty substances selected from those indicated above for the liquid fatty phase.

When the composition of the invention is an emulsion, the proportion of the fatty phase comprising oils and other fatty substances can range from 5 to 80% by weight and preferably from 5 to 50% by weight relative to the total weight of the composition. .

The fats, emulsifiers and coemulsifiers used in the composition in emulsion form are chosen from those conventionally used in the field under consideration. The emulsifier and the coemulsifier may be present in the composition in a proportion ranging from 0.3 to 30% by weight, and preferably from 0.5 to 20% by weight relative to the total weight of the composition. As emulsifiers and coemulsifiers that can be used in the invention, mention may be made, for example, of fatty acid and polyethylene glycol esters such as

<Desc / Clms Page number 14>

 PEG-50 stearate and PEG-40 stearate, fatty acid esters of polyol such as glyceryl stearate and sorbitan tristearate, and ethers of fatty alcohols and polyethylene glycols, or mixtures thereof as the product marketed by the company Gattefossé under the name HYDROLACTOL 70)) comprising the mixture: glyceryl stearate, propylene glycol stearate, glyceryl isostearate, propylene glycol isostearate, oleth-25 (oleic alcohol polyethylene glycol ether containing 25 units oxyethylenated) and ceteth-25 (cetyl alcohol polyethylene glycol ether containing 25 oxyethylenated units).

Furthermore, the composition according to the invention may contain adjuvants commonly used in cosmetic compositions. In particular, these compositions may comprise: cosmetic active agents such as softeners, antioxidants, opacifiers, emollients, hydroxy acids, vitamins, moisturizers, perfumes, preservatives, sequestering agents, UV filters, ceramides anti-free radical agents, bactericides; complexing agents, anti-bacterials, tensing agents other than those of the present application, such as protein hydrolysates, silicon compounds described in EPA-1, 008, 340 or dendritic polymers described in EP -A-0,987,016; - fillers, nacres, lacquers; thickeners, gelling agents, propellants, pH adjusting agents (alkalizing or acidifying agents), plasticizers, surfactants; additional hydrophilic or water-soluble polymers, such as polyvinyl alcohols and their copolymers; polysaccharides or cellulosic polymers; natural proteins or synthetic polypeptides.

Of course, those skilled in the art will take care to choose this or these optional adjuvants, 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 considered.

d'une pommade, d'un lait, d'une lotion, d'un sérum, d'une pâte, d'une mousse. The compositions according to the invention may be in various forms and in particular in the form of oily solutions or in a solvent medium, oily gels, oily dispersions, oil-in-water, water-in-oil or multiple emulsions, microemulsions, microcapsules, microparticles or vesicular dispersions of ionic or nonionic type. They may be of liquid or semi-liquid consistency of the milk type, or of soft or semi-solid consistency of the cream or gel type, or in solid form such as in stick or stick form. These compositions may have the appearance of a white or colored cream,

an ointment, a milk, a lotion, a serum, a paste, a mousse.

They can optionally be applied to the skin in the form of an aerosol.

The compositions according to the invention find a particular application as a protective or care product for the skin of the face, neck, hands or body, especially as a composition with a tensor effect, anti-fatigue to give a boost to the skin.

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 The invention is illustrated in more detail in the following examples. Percentages are percentages by weight unless otherwise indicated.

EXAMPLE 1 Dispersion of Polymer Particles in a Liquid Fat Phase A dispersion of polymethyl methacrylate crosslinked with ethylene glycol dimethacrylate is prepared in volatile branched paraffin oil (ISOPAR L from Exxon) according to the method of US Pat. EXAMPLE 2 of EP-A-749746 360 g of ISOPAR L and 15 g of block copolymer polymer of the polystyrene / copoly (ethylene-propylene) diblock copolymer type sold under the name KRATON G1701 (hell) are mixed. The mixture is heated for at least 3 hours at about 60 ° C to obtain a dispersed solution.

At 25 ° C., 19 g of methyl methacrylate, 1 g of ethylene glycol dimethacrylate, 0.4 g of tert-butylperoxy-2-ethylhexanoate (Trigonox 21S from Akzo) and 5 g of ISOPAR L. are added to the mixture. The mixture is heated at 75 ° C under nitrogen for at least 3 hours. A mixture of 76 g of methyl methacrylate, 4 g of ethylene glycol dimethacrylate and 1.6 g of tert-butylperoxy-2-ethylhexanoate (Trigonox 21S from Akzo) is then added at 75 ° C. for 1.5 hours. 80 g of ISOPAR L. At the end of the addition, the mixture is heated at 85 ° C. for 4 hours, 1 g of Trigonox dissolved in 5 g of ISOPAR L is added and the mixture is heated at 85 ° C. for 7 hours.

This gives a stable dispersion of polymethyl methacrylate particles in ISOPAR L, surface stabilized by a styrene / ethylene-propylene block diblock copolymer (SEP) sold under the name Kraton G1701 (hell), having a dry matter of 19% by weight and an average particle size of 159 nm.

Examples 2 and 3: anhydrous serum

<Tb>
<tb> Composition <SEP> Example <SEP> 2 <SEP> Example <SEP> 3
<tb> Dispersion <SEP> of <SEP> Example <SEP> 190, <SEP> 5 <SEP>% <SEP> 97, <SEP> 8 <SEP>%
<tb> Apricot oil <SEP> 9, <SEP> 5 <SEP>% <SEP> 2, <SEP> 2%
<tb> Percentage <SEP> of <SEP> retraction-3, <SEP> 7 <SEP>% <SEP> +/- 0, <SEP> 7-2, <SEP> 94 <SEP>% <SEP> + / -0.8
<tb> to <SEP> the extensometer
<Tb>
Procedure: The oil introduced into the dispersion of polymer particles is mixed with stirring at room temperature (about 20 to 25 ° C.). An opalescent fluid gel is obtained.

<Desc / Clms Page number 16>

Extensometer Measurement Method: The principle consists in measuring, before treatment and after treatment of the skin by the studied composition, the length of an isolated stratum comeum specimen and determining the percentage of retraction of the specimen.

Specimens with a surface area of 1 cm × 0.4 cm of stratum corneum, with a thickness ranging from 10 to 20 μm, are used, placed on the extensometer MTT 610 sold by the company DIASTRON. The test specimen is placed between 2 jaws and then left for 12 hours in an atmosphere at 30 ° C. and 40% relative humidity. The specimen with a length of between 5 and 10% of the initial length is drawn at a speed of 2 mm / minute to determine the length L1 from which the specimen begins to exert a force on the jaws and detected by the device. The test piece is then relaxed and then 2 mg of the composition studied is applied to the stratum corneum. After complete evaporation of the composition, the test specimen is towed under the same conditions as those described previously to also determine the length L 2 for the treated specimen.

The shrinkage percentage is determined by the ratio: 100 x (L-L)) / L.

application des produits. On note une nette diminution de la visibilité des rides 30 minutes après l'application de la composition selon l'invention. Photographic visualization: models are photographed before and after

application of products. There is a clear decrease in the visibility of the wrinkles 30 minutes after application of the composition according to the invention.

EXAMPLE 4 HIE Emulsion Phase A 1 Hydrolactol-70 6% Apricot Oil 1% Preservatives 0.2% Phase A2 Dispersion of Example 1 10% Phase B 1 Glycerin 5% Carbomer 0.4% Preservatives 0.2% Deionized water qs 100% Phase B2 Triethanolamine 0.4% Procedure: The phase A1 is heated separately to a water bath at about 75 ° C. and the B1 phase is stirred at approximately 75 ° C. When phase B1 is homogeneous and lipid, phase B2 is added to neutralize Carbomer. Then we cool the phases, and after returning to room temperature, we add the

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phase A2 à la phase A1 et on émulsionne en versant le mélange (A1 + A2) dans le mélange (Bl + B2) sous agitation. On arrête l'agitation quand l'émulsion est homogène.

phase A2 to phase A1 and emulsified by pouring the mixture (A1 + A2) into the mixture (Bl + B2) with stirring. Stirring is stopped when the emulsion is homogeneous.

Extensometer result: -0.6% +/- 0.3.

Claims (21)

 1. Cosmetic use of at least one dispersion of polymer particles in a liquid fatty phase, as tensioning agent for the skin. 2. Cosmetic use of a cosmetic composition containing at least one dispersion of polymer particles in a fatty phase, for retightening the skin and / or blurring the wrinkles or fine lines of the skin by a tensor effect, and / or for giving a whitening effect. to the skin. 3. Cosmetic use of at least one dispersion of polymer particles in a liquid fatty phase, to obtain a film giving an isolated stratum comeum shrinkage greater than about 0.5%, measured using an extensometer, to At 40% relative humidity for a concentration of 7% by weight of polymer solids in a solvent. 4. Use according to any one of the preceding claims,

 characterized in that the polymer is non-film-forming. 5. Use according to any one of the preceding claims, characterized in that the polymer particles are spherical. 6. Use according to the preceding claim, characterized in that the polymer particles are nanoparticles having a number average size ranging from 5 to 600 nm. 7. Use according to any one of the preceding claims, characterized in that the polymer particles dispersed has a molecular weight of the order of 2000 to 10 000 000.

8. Use according to any one of the preceding claims, characterized in that the polymer particles dispersed has a Tg greater than 40 C. 9. Use according to any one of the preceding claims, characterized in that the polymer of the particles in dispersion has a Tg ranging from 45 C to 300 C. 10. Use according to any one of the preceding claims, characterized in that the polymer of the particles in dispersion is chosen from

 homopolymers or radical copolymers, acrylic or vinyl, and mixtures thereof. 11. Use according to any one of the preceding claims, characterized in that the polymer particles dispersed is selected from copolymers of (meth) acrylic acid and (meth) acrylate. <Desc / Clms Page number 19> 12. Use according to any one of the preceding claims, characterized in that the particles in dispersion contain at least one stabilizer selected from block polymers, graft polymers, random polymers and mixtures thereof. 13. Use according to the preceding claim, characterized in that the stabilizer is a grafted or sequenced block polymer, comprising at least one block resulting from the polymerization of diene and at least one block of a vinyl polymer. 14. Use according to any one of claims 2 to 13, characterized in that the polymer dispersion represents (in dry matter) from 0.1 to 40% and preferably from 1 to 30% of the total weight of the composition. 15. Use according to any one of the preceding claims, characterized in that the liquid fatty phase consists of oils of mineral origins, animal, vegetable or synthetic, carbonaceous, hydrocarbon, fluorinated and / or silicone, alone or in mixture . 16. Use according to any one of the preceding claims, characterized in that the liquid fatty phase contains at least one non-volatile oil. 17. Use according to any one of the preceding claims characterized in that the liquid fatty phase contains at least one volatile oil and a non-volatile oil. 18. Use according to any one of claims 2 to 17, characterized in that the composition further comprises one or more fatty substances selected from waxes, gums and / or pasty fatty substances, hydrocarbon, silicone and / or fluorinated, of vegetable, animal, mineral or synthetic origin, and mixtures thereof. 19. Use according to any one of claims 2 to 18, characterized in that the composition is in anhydrous form. 20. Use according to the preceding claim characterized in that the liquid fatty phase is from 60 to 99.9% by weight relative to the total weight of the composition. 21. A method of cosmetic treatment of wrinkled skin consisting in applying thereto a cosmetic composition containing at least one dispersion of polymer particles in a liquid fatty phase, in an amount effective to immediately reduce the wrinkle or the wrinkle by tensor effect and / or tighten the skin.