WO2012098116A1

WO2012098116A1 - Anhydrous cosmetic composition comprising a crosslinked silicone elastomer and a volatile linear alkane

Info

Publication number: WO2012098116A1
Application number: PCT/EP2012/050641
Authority: WO
Inventors: Roshanak Debeaud; Vincent Grandjon; Mallaury GOUGE
Original assignee: L'oreal
Priority date: 2011-01-17
Filing date: 2012-01-17
Publication date: 2012-07-26
Also published as: EP2665522A1; FR2970413B1; FR2970413A1

Abstract

The present invention relates to an anhydrous cosmetic composition for caring for and/or making up keratin materials, in particular the skin, comprising, in a physiologically acceptable medium: (i) one or more crosslinked silicone elastomers in a total content, of active material, of greater than or equal to 5% by weight relative to the total weight of said composition, (ii) one or more volatile linear alkanes, especially C7-C15 alkanes, in a total content of greater than or equal to 5% by weight relative to the total weight of said composition, and (iii) at least one additional cosmetic ingredient.

Description

Anhydrous cosmetic composition comprising a crosslinked silicone elastomer and a volatile linear alkane

The field of the invention relates to an anhydrous cosmetic composition comprising a significant amount, as active material, of silicone elastomer and one or more volatile linear alkanes.

The composition of the invention may be in the form of a care composition for the skin or the hair, or of a sun protection composition. It is then in a colourless form, optionally containing cosmetic or dermatological active agents. It may then be used as a care base for keratin materials such as especially the skin or the lips or keratin fibres.

The composition of the invention may also be in the form of a coloured product for making up keratin materials such as especially the skin, and especially a foundation, a blusher, a face powder or eyeshadow, or for making up the lips such as a lipstick, optionally comprising cosmetic active agents imparting care properties to them or a coloured product for the hair.

Cosmetic compositions containing a continuous fatty phase, and in particular anhydrous compositions, are commonly used in cosmetics due to their good adhesion to the skin, their protective ability and their ability to form a water-impermeable film. The makeup obtained is comfortable and does not dry the skin.

However, due to their high content of fatty subtances, this type of product has the drawback of leaving on the skin a greasy or tacky feeling and/or a shiny appearance. The use of crosslinked silicone elastomers, in particular those with the I NCI name dimethicone crosspolymer and vinyl/dimethicone crosspolymer, the sensory properties of which are recognized in cosmetic compositions for improving the glide of the compositions on application and their matt effect after application, is known from the prior art. It is thus sought to incorporate these elastomers, in a large amount, into cosmetic compositions.

However, the incorporation of a large amount of said elastomers may generate, in combination with the oils of the liquid fatty phase, in particular cyclic volatile silicone oils, problems of viscosity and consequently a loss of cosmeticity and of use of said composition and of its performances on application.

Therefore there remains the need to find combinations of these silicone elastomers with compatible solvents that would enable them to be incorporated into cosmetic compositions in a large amount without affecting the viscosity of said compositions. Unexpectedly, the Applicant has been able to demonstrate that the use of one or more volatile linear alkanes in an anhydrous composition comprising a high content of crosslinked silicone elastomers made it possible to obtain a composition that was easier to use and to apply to keratin materials despite the high content of silicone elastomers: the composition according to the invention is more fluid and stable over time and gives the keratin material to which it is applied a silky and soft feel, a powdery feel and a matt and soft-focus finish, while exhibiting improved cosmetic properties on application (comfort).

Indeed, the Inventors have observed that the combination of volatile linear alkanes with crosslinked silicone elastomers at a high content, makes it possible to considerably reduce the viscosity of formulae containing said elastomers, compared to the same formula in the presence of a cyclic silicone oil for example. And this reduction in the viscosity of the formulae is further improved when use is made, as crosslinked silicone elastomer, of a crosslinked silicone elastomer in the form of a gel of crosslinked silicone elastomer dispersed in a linear silicone oil having a viscosity ranging from 1 to 500 centistokes (cSt) at 25°C.

Care and/or makeup compositions are known from applications EP 2 1 11 847 and DE102008012457 that comprise volatile linear alkanes and gels of crosslinked silicone elastomers dispersed in a linear silicone oil (Nulastik Silk MA, DM from Alzo or DC9041 from Dow Corning) or cyclic silicone oil (DC9040 from Dow Corning).

But, to the knowledge of the Applicant, until now it has never been proposed to use volatile linear alkanes, especially C7-C15 alkanes, in anhydrous compositions comprising a high content of crosslinked silicone elastomer (greater than or equal to 5% by weight of active material), the high content of which is known to have an impact on the fluidity of the composition, to reduce the viscosity of said compositions and to have compositions that are more fluid and stable.

According to a first aspect, the invention relates to an anhydrous cosmetic composition for caring for and/or making up keratin materials, in particular the skin, comprising, in a physiologically acceptable medium: one or more crosslinked silicone elastomers in a total content, of active material, of greater than or equal to 5% by weight relative to the total weight of said composition,

one or more volatile linear alkanes, especially C7-C15 alkanes, in a total content of greater than or equal to 5% by weight relative to the total weight of said composition, and

at least one additional cosmetic ingredient.

The additional cosmetic ingredient is chosen from oils, thickeners, gelling agents, pulverulent materials, UV screening agents, neutralizing agents, and mixtures thereof.

In particular, said additional cosmetic ingredient is chosen from oils, pulverulent materials chosen from fillers and pulverulent dyestuffs, and mixtures thereof.

The additional ingredient is present in the composition in a content ranging from 0.1 % to 50% by weight relative to the total weight of the composition, in particular from 1 % to 30% by weight, and especially from 2% to 20% by weight relative to the total weight of said composition.

In particular, the crosslinked silicone elastomer is present in the composition in a content, of active material, ranging from 5% to 22% by weight, especially from 6% to 18% by weight, in particular from 7% to 15% by weight and preferably from 8% to 12% by weight of active material relative to the total weight of said composition. According to one particular embodiment, the silicone elastomer is in the form of a gel of crosslinked silicone elastomer dispersed in a silicone oil.

The crosslinked silicone elastomer may be in the form of a gel of crosslinked silicone elastomer dispersed in a cyclic silicone oil.

According to one preferred embodiment, the crosslinked silicone elastomer is in the form of a gel of crosslinked silicone elastomer dispersed in a linear silicone oil, in particular having a viscosity ranging from 1 to 500 centistokes (cSt) at 25°C. In particular, the volatile linear alkane(s) is (are) present in a content ranging from 5% to 50% by weight, especially from 7% to 40% by weight and in particular from 10% to 35% by weight relative to the total weight of the composition. The crosslinked silicone elastomers according to the invention will generally have the I NCI name: 'dimethicone cross polymer', 'vinyldimethicone crosspolymer', 'dimethicone crosspolymer-3' or 'dimethicone/vinyl dimethicone crosspolymer'.

The preferred elastomers according to the invention are those corresponding to the I NCI name 'dimethicone crosspolymer' and 'dimethicone/vinyl dimethicone crosspolymer'.

The composition according to the invention is in anhydrous form, that is to say that it comprises less than 4% by weight of water, preferably less than 3%, preferably less than 2%, more preferably less than 1 %, more preferably still less than 0.5% by weight of water, relative to the total weight of said composition, or even is completely water-free.

VOLATILE LINEAR ALKANES The composition of the invention comprises one or more volatile linear alkanes, especially C7-C15 alkanes.

The term "one or more volatile linear alkane(s)" means, without preference, "one or more volatile linear alkane oil(s)".

A volatile linear alkane that is suitable for the invention is liquid at room temperature (about 25°C) and at atmospheric pressure (760 mmHg).

A "volatile linear alkane" that is suitable for the invention means a cosmetic linear alkane, which is capable of evaporating on contact with the skin in less than one hour, at room temperature (25°C) and atmospheric pressure (760 mmHg, i.e. 101 325 Pa), which is liquid at room temperature, especially having an evaporation rate ranging from 0.01 to 15 mg/cm²/min, at room temperature (25°C) and atmospheric pressure (760 mmHg).

Preferably, the "volatile linear alkanes" that are suitable for the invention have an evaporation rate ranging from 0.01 to 3.5 mg/cm²/min, at room temperature (25°C) and atmospheric pressure (760 mmHg). Preferably, the "volatile linear alkanes" that are suitable for the invention have an evaporation rate ranging from 0.01 to 1.5 mg/cm²/min, at room temperature (25°C) and atmospheric pressure (760 mmHg).

More preferably, the "volatile linear alkanes" that are suitable for the invention have an evaporation rate ranging from 0.01 to 0.8 mg/cm²/min, at room temperature (25°C) and atmospheric pressure (760 mmHg).

Even more preferably, the "volatile linear alkanes" that are suitable for the invention have an evaporation rate ranging from 0.01 to 0.3 mg/cm²/min, at room temperature (25°C) and atmospheric pressure (760 mmHg).

Even more preferably, the "volatile linear alkanes" that are suitable for the invention have an evaporation rate ranging from 0.01 to 0.12 mg/cm²/min, at room temperature (25°C) and atmospheric pressure (760 mmHg).

The evaporation rate of a volatile alkane in accordance with the invention (and more generally of a volatile solvent) may especially be evaluated by means of the protocol described in WO 06/013 413, and more particularly by means of the protocol described below.

15 g of volatile hydrocarbon-based solvent are placed in a crystallizing dish (diameter: 7 cm) placed on a balance that is in a chamber of about 0.3 m³ which is temperature-regulated (25°C) and hygrometry-regulated (50% relative humidity).

The liquid is allowed to evaporate freely, without stirring, while providing ventilation by means of a fan (Papst-Motoren, reference 8550 N, rotating at 2700 rpm) placed vertically above the crystallizing dish containing the volatile hydrocarbon-based solvent, the blades being directed toward the crystallizing dish, 20 cm away from the bottom of the crystallizing dish.

The mass of volatile hydrocarbon-based solvent remaining in the crystallizing dish is measured at regular time intervals.

The evaporation profile of the solvent is then obtained by plotting the curve of the amount of product evaporated (in mg/cm²) as a function of the time (in minutes).

The evaporation rate is then calculated, which corresponds to the tangent to the origin of the curve obtained. The evaporation rates are expressed in mg of volatile solvent evaporated per unit area (cm²) and per unit of time (minutes).

According to one preferred embodiment, the "volatile linear alkanes" that are suitable for the invention have a non-zero vapour pressure (also known as the saturation vapour pressure), at room temperature, in particular a vapour pressure ranging from 0.3 Pa to 6000 Pa.

Preferably, the "volatile linear alkanes" that are suitable for the invention have a vapour pressure ranging from 0.3 to 2000 Pa, at room temperature (25°C).

Preferably, the "volatile linear alkanes" that are suitable for the invention have a vapour pressure ranging from 0.3 to 1000 Pa, at room temperature (25°C).

More preferably, the "volatile linear alkanes" that are suitable for the invention have a vapour pressure ranging from 0.4 to 600 Pa, at room temperature (25°C).

Preferably, the "volatile linear alkanes" that are suitable for the invention have a vapour pressure ranging from 1 to 200 Pa, at room temperature (25°C).

More preferably, the "volatile linear alkanes" that are suitable for the invention have a vapour pressure ranging from 3 to 60 Pa, at room temperature (25°C).

According to one embodiment, a volatile linear alkane that is suitable for the invention may have a flash point that is in the range from 30 to 120°C and more particularly from 40 to 100°C. The flash point is in particular measured according to standard ISO 3679.

According to one embodiment, an alkane that is suitable for the invention may be a volatile linear alkane comprising from 7 to 15 carbon atoms, in particular from 7 to 14 carbon atoms.

Preferably, the "volatile linear alkane(s)" that are suitable for the invention comprise from 8 to 15 carbon atoms, in particular from 8 to 14 carbon atoms.

Preferably, the "volatile linear alkane(s)" that are suitable for the invention comprise from 9 to 15 carbon atoms, in particular from 9 to 14 carbon atoms.

Preferably, the "volatile linear alkane(s)" that are suitable for the invention comprise from 10 to 15 carbon atoms, in particular from 10 to 14 carbon atoms.

Preferably, the "volatile linear alkane(s)" that are suitable for the invention comprise from 1 1 to 15 carbon atoms, in particular from 11 to 14 carbon atoms.

According to one advantageous embodiment, the "volatile linear alkanes" that are suitable for the invention have an evaporation rate, as defined above, ranging from 0.01 to 3.5 mg/cm²/minute, at room temperature (25°C) and atmospheric pressure (760 mmHg), and comprise from 7 to 15 carbon atoms, in particular from 8 to 14 carbon atoms. A volatile linear alkane that is suitable for the invention may advantageously be of plant origin.

Preferably, the volatile linear alkane or the mixture of volatile linear alkanes present in the composition according to the invention comprises at least one ¹⁴C (carbon- 14) carbon isotope. In particular, the ¹⁴C isotope may be present in a ¹⁴C/¹²C ratio of greater than or equal to 1 * 10^"16, preferably greater than or equal to 1 * 10^"15, more preferably greater than or equal to 7.5x 10^"14 and better still greater than or equal to 1.5 10^"13. Preferably, the ratio ¹⁴C/¹²C ranges from 6 10^"13 to 1.2x 10^"12.

The amount of ¹⁴C isotopes in the volatile linear alkane or the mixture of volatile linear alkanes may be determined via methods known to those skilled in the art such as the Libby counting method, liquid scintillation spectrometry or accelerator mass spectrometry.

Such an alkane may be obtained, directly or in several steps, from a plant raw material, such as an oil, a butter, a wax, etc.

As examples of alkanes that are suitable for the invention, mention may be made of the alkanes described in patent applications by the company Cognis WO 2007/068371 or WO 2008/155059 (mixtures of different alkanes differing by at least one carbon). These alkanes are obtained from fatty alcohols, which are themselves obtained from coconut oil or palm oil.

As examples of linear alkanes that are suitable for the invention, mention may be made of n-heptane (C7), n-octane (C8), n-nonane (C9), n-decane (C10), n-undecane (C11), n-dodecane (C12), n-tridecane (C13) and n-tetradecane (C14), n-pentadecane (C15) and mixtures thereof. According to one particular embodiment, the volatile linear alkane is chosen from n-nonane, n-undecane, n-dodecane, n-tridecane, n-tetradecane and n-pentadecane, and mixtures thereof.

According to one preferred embodiment, mention may be made of mixtures of n-undecane (C1 1) and of n-tridecane (C13) obtained in Examples 1 and 2 of patent application WO 2008/155059 by the company Cognis.

Mention may also be made of n-dodecane (C12) and n-tetradecane (C14) such as those sold by Sasol under the references, respectively, Parafol 12-97 and Parafol 14-97, and also mixtures thereof. The volatile linear alkane may also be used alone. Alternatively or preferentially, a mixture of at least two different volatile linear alkanes, differing from each other by a carbon number n of at least 1 , in particular differing from each other by a carbon number of 1 or 2, may be used. According to a first embodiment, a mixture of at least two different volatile linear alkanes comprising from 10 to 15 carbon atoms and differing from each other by a carbon number of at least 1 may be used. Examples that may especially be mentioned include mixtures of C10/C1 1 , C11/C12 or C12/C13 volatile linear alkanes.

According to another embodiment, a mixture of at least two different volatile linear alkanes comprising from 10 to 15 carbon atoms and differing from each other by a carbon number of at least 2 is used. Examples that may especially be mentioned include mixtures of C10/C12 or C12/C14 volatile linear alkanes, for an even carbon number n and the C11/C13 mixture for an odd carbon number n.

According to one preferred embodiment, a mixture of at least two different volatile linear alkanes comprising from 10 to 14 carbon atoms and differing from each other by a carbon number of at least 2, and in particular a mixture of C11/C13 volatile linear alkanes or a mixture of C12/C14 volatile linear alkanes, is used.

Other mixtures combining more than two volatile linear alkanes according to the invention, for instance a mixture of at least three different volatile linear alkanes comprising from 7 to 15 carbon atoms and differing from each other by a carbon number of at least 1 , also form part of the invention, but mixtures of two volatile linear alkanes according to the invention are preferred (binary mixtures), said two volatile linear alkanes preferably representing more than 95% and better still more than 99% by weight of the total content of volatile linear alkanes in the mixture.

According to one particular embodiment of the invention, in a mixture of volatile linear alkanes, the volatile linear alkane having the smallest carbon number is predominant in the mixture.

According to another embodiment of the invention, a mixture of volatile linear alkanes in which the volatile linear alkane having the largest carbon number is predominant in the mixture is used.

As examples of mixtures that are suitable for the invention, mention may be made especially of the following mixtures:

- from 50% to 90% by weight, preferably from 55% to 80% by weight and more preferentially from 60% to 75% by weight of a Cn volatile linear alkane with n ranging from 7 to 15, - from 10% to 50% by weight, preferably from 20% to 45% by weight and preferably from 24% to 40% by weight of a Cn+x volatile linear alkane with x greater than or equal to 1 , preferably x = 1 or x = 2, with n+x between 8 and 15,

relative to the total weight of alkanes in said mixture.

In particular, said mixture of alkanes according to the invention contains:

less than 2% by weight and preferably less than 1 % by weight of branched hydrocarbons,

- and/or less than 2% by weight and preferably less than 1 % by weight of aromatic hydrocarbons,

and/or less than 2% by weight, preferably less than 1 % by weight and preferentially less than 0.1 % by weight of unsaturated hydrocarbons in the mixture.

More particularly, a volatile linear alkane that is suitable for the invention may be used in the form of a predominantly n-undecane/n-tridecane mixture.

In particular, use will be made of a mixture of volatile linear alkanes comprising:

- from 55% to 80% by weight and preferably from 60% to 75% by weight of a C11 volatile linear alkane (n-undecane),

- from 20% to 45% by weight and preferably from 24% to 40% by weight of a C13 volatile linear alkane (n-tridecane),

relative to the total weight of alkanes in said mixture.

According to one particular embodiment, the mixture of alkanes is an n- undecane/n-tridecane mixture. In particular, such a mixture may be obtained according to Example 1 or Example 2 of WO 2008/155059.

According to another particular embodiment, n-dodecane, such as that sold under the reference Parafol 12-97 by Sasol, is used.

According to another particular embodiment, n-tetradecane, such as that sold under the reference Parafol 14-97 by Sasol, is used. According to yet another embodiment, a mixture of n-dodecane and n- tetradecane is used.

According to one particular embodiment of the invention, the composition may comprise less than 10% by weight, or even less than 5% by weight, or even less than 2% by weight, or may even be free of cyclic silicone oil.

The volatile linear alkane(s) according to the invention may be present in the composition in a content ranging from 5% to 50% by weight, in particular from 7% to 40% by weight, especially from 10% to 35% and in particular from 20% to 35% by weight relative to the total weight of said composition.

According to one preferred embodiment of the invention, the volatile linear alkane(s) used according to the invention represent(s) from 15% to 100%, preferably from 18% to 60% by weight, relative to the total weight of the volatile oils of the composition, taking into account the volatile oils optionally introduced by the crosslinked silicone elastomer.

In particular, the volatile linear alkane(s) used according to the invention represent(s) from 15% to 100%, preferably from 18% to 60% by weight, relative to the total weight of the oils of the composition, taking into account the oils optionally introduced by the crosslinked silicone elastomer.

The composition according to the invention also comprises at least one particular silicone elastomer as defined below.

SILICONE ELASTOMERS

The silicone copolymers according to the invention, also known as elastomeric organopolysiloxanes, or silicone elastomers in the present description, are in general partially or completely crosslinked and have a three-dimensional structure.

Reference will be made, without preference, to 'crosslinked silicone copolymer' or 'silicone elastomer'. In particular, the silicone elastomer used in the present invention is chosen from Dimethicone Crosspolymer (INCI name), Vinyl Dimethicone Crosspolymer (INCI name), Dimethicone/Vinyl Dimethicone Crosspolymer (INCI name), Dimethicone Crosspolymer-3 (INCI name).

It is generally in the form of a gel, a paste or a powder, but advantageously in the form of a gel in which the silicone elastomer is dispersed in a linear silicone oil (dimethicone) or cyclic silicone oil (e.g.: cyclopentasiloxane).

The elastomeric crosslinked organopolysiloxane may be obtained:

by a crosslinking addition reaction of a diorganopolysiloxane containing at least one hydrogen bonded to silicon and of a diorganopolysiloxane containing ethylenically unsaturated groups bonded to silicon, especially in the presence of a platinum catalyst; or

by a dehydrogenation crosslinking condensation reaction between a hydroxyl-terminated diorganopolysiloxane and a diorganopolysiloxane containing at least one hydrogen bonded to silicon, especially in the presence of an organotin reagent; or

by a crosslinking condensation reaction of a hydroxyl-terminated diorganopolysiloxane and of a hydrolysable organopolysilane; or by thermal crosslinking of an organopolysiloxane, especially in the presence of an organic peroxide catalyst; or

by crosslinking of an organopolysiloxane with high-energy radiation such as gamma rays, ultraviolet rays or an electron beam.

Preferably, the elastomeric crosslinked organopolysiloxane is obtained by a crosslinking addition reaction (A2) of a diorganopolysiloxane containing at least two hydrogens each bonded to a silicon, and (B2) of a diorganopolysiloxane containing at least two ethylenically unsaturated groups bonded to silicon, especially in the presence (C2) of a platinum catalyst, for instance as described in patent application EP-A-295 886.

In particular, the organopolysiloxane may be obtained by reaction of dimethylvinylsiloxy- terminated dimethylpolysiloxane and of trimethylsiloxy-terminated methylhydropolysiloxane, in the presence of a platinum catalyst. Compound (A2) is the base reagent for the formation of an elastomeric organopolysiloxane and the crosslinking is performed via an addition reaction of compound (A2) with compound (B2) in the presence of the catalyst (C2). Compound (A2) is in particular an organopolysiloxane containing at least two hydrogen atoms bonded to different silicon atoms in each molecule. Compound (A2) may have any molecular structure, especially a linear-chain or branched- chain structure or a cyclic structure, preferably a linear structure.

Compound (A2) may have a viscosity at 25°C ranging from 1 to 50 000 centistokes, especially in order to have good miscibility with compound (B2).

The organic groups bonded to the silicon atoms of compound (A2) may be alkyl groups, especially C1-C24, in particular C4-C24 alkyl groups, such as methyl, ethyl, propyl, butyl, octyl; substituted alkyl groups such as 2-phenylethyl, 2-phenylpropyl or 3,3,3- trifluoropropyl; aryl groups such as phenyl, tolyl, xylyl; substituted aryl groups such as phenylethyl; and substituted monovalent hydrocarbon-based groups such as an epoxy group, a carboxylate ester group or a mercapto group. Preferably, the organic groups bonded to the silicon atoms of compound (A2) are C4-C24 alkyl groups.

Compound (A2) may thus be chosen from trimethylsiloxy-terminated methylhydropolysiloxanes, trimethylsiloxy-terminated dimethylsiloxane/methyl- hydrosiloxane copolymers, and dimethylsiloxane/methylhydrosiloxane cyclic copolymers.

Compound (B2) is advantageously a diorganopolysiloxane containing at least two lower alkenyl groups (for example C₂-C₄ alkenyl groups); the lower alkenyl group may be chosen from vinyl, allyl and propenyl groups. These lower alkenyl groups may be located in any position of the organopolysiloxane molecule, but are preferably located at the ends of the organopolysiloxane molecule. The organopolysiloxane (B2) may have a branched- chain, linear-chain, cyclic or network structure, but the linear-chain structure is preferred. Compound (B2) may have a viscosity ranging from the liquid state to the gum state. Preferably, compound (B2) has a viscosity of at least 100 centistokes at 25°C.

Besides the abovementioned alkenyl groups, the other organic groups bonded to the silicon atoms in compound (B2) may be alkyl groups, especially C1-C24, in particular C4- C24 alkyl groups, such as methyl, ethyl, propyl, butyl or octyl; substituted alkyl groups such as 2-phenylethyl, 2-phenylpropyl or 3,3,3-trifluoropropyl; aryl groups such as phenyl, tolyl or xylyl; substituted aryl groups such as phenylethyl; and substituted monovalent hydrocarbon-based groups such as an epoxy group, a carboxylate ester group or a mercapto group.

The organopolysiloxanes (B2) may be chosen from methylvinylpolysiloxanes, methylvinylsiloxane/dimethylsiloxane copolymers, dimethylvinylsiloxy-terminated dimethylpolysiloxanes, dimethylvinylsiloxy-terminated dimethylsiloxane/methylphenyl- siloxane copolymers, dimethylvinylsiloxy-terminated dimethylsiloxane/diphenyl- siloxane/methylvinylsiloxane copolymers, trimethylsiloxy-terminated dimethylsiloxane/methylvinylsiloxane copolymers, trimethylsiloxy-terminated dimethylsiloxane/methylphenylsiloxane/methylvinylsiloxane copolymers, dimethylvinylsiloxy-terminated methyl(3,3,3-trifluoropropyl)polysiloxanes, and dimethylvinylsiloxy-terminated dimethylsiloxane/methyl(3,3,3-trifluoropropyl)siloxane copolymers. In particular, the elastomeric organopolysiloxane may be obtained via reaction of dimethylvinylsiloxy-terminated dimethylpolysiloxane and of trimethylsiloxy-terminated methylhydropolysiloxane, in the presence of a platinum catalyst.

Advantageously, the sum of the number of ethylenic groups per molecule in compound (B2) and of the number of hydrogen atoms bonded to silicon atoms per molecule in compound (A2) is at least 5.

It is advantageous for compound (A2) to be added in an amount such that the molar ratio between the total amount of hydrogen atoms bonded to silicon atoms in compound (A2) and the total amount of all the ethylenically unsaturated groups in compound (B2) is within the range from 1.5/1 to 20/1.

Compound (C2) is the catalyst for the crosslinking reaction, and is especially chloroplatinic acid, chloroplatinic acid-olefin complexes, chloroplatinic acid- alkenylsiloxane complexes, chloroplatinic acid-diketone complexes, platinum black and platinum on a support.

The catalyst (C2) is preferably added in an amount of from 0.1 to 1000 parts by weight and better still from 1 to 100 parts by weight, as clean platinum metal, per 1000 parts by weight of the total amount of compounds (A) and (B). Elastomers are especially described in patents US 4 970 252, US 4 987 169, US 5 412 004, US 5 654 362 and US 5 760 1 16 and in patent application JP-A-61- 194 009.

Mention may be made advantageously of elastomers of dimethicone crosspolymer type (I NCI name) described in patents US 5 599 533 and US 6 027 738.

According to one particular embodiment, the organopolysiloxane elastomer is crosslinked with a C4 to C22, preferably C4 to C16, preferentially C6 to C12 hydrocarbon-based chain.

In particular, the organopolysiloxane elastomer is crosslinked with a hexadiene.

Preferably, the silicone elastomer used according to the invention is in the form of a gel of silicone elastomer in an oily vehicle, in particular a silicone vehicle.

The silicone elastomer according to the invention may be mixed with at least one silicone oil in order to form a gel. According to one particular embodiment, it will be a cyclic or linear silicone oil, in particular a linear silicone oil (dimethylsiloxane) having a molecular weight ranging from 1 to 500 cSt at 25°C.

The linear silicone oil may be volatile or non-volatile and may advantageously have a viscosity at 25°C ranging from 1 to 500 centistokes (cSt) (10 x 10^"6 m²/s), in particular from 2 to 350 cSt, especially from 2 to 100 cSt and in particular from 2 to 10 cSt, or even from 2 to 6 cSt, limits included.

The viscosity of these silicone oils may be measured according to standard ASTM D-445. In particular, the volatile or non-volatile silicone oils that can be used in the invention preferably have a viscosity at 25°C of less than 100 cSt, preferably less than or equal to 10 cSt and preferably less than or equal to 8 cSt. The term "oil" means a water-immiscible non-aqueous compound that is liquid at room temperature (25°C) and at atmospheric pressure (760 mmHg).

For the purposes of the present invention, the term "silicone oil" means an oil comprising at least one silicon atom, and especially at least one Si-0 group. The term "volatile oil" means any non-aqueous medium that is capable of evaporating from the keratin material in less than one hour, at room temperature and atmospheric pressure. The volatile oil is a cosmetic volatile oil, which is liquid at room temperature. More specifically, a volatile oil has an evaporation rate of between 0.01 and 200 mg/cm²/min, limits included.

The term "non-volatile oil" means an oil that remains on the skin or the keratin material at room temperature and atmospheric pressure. More specifically, a non-volatile oil has an evaporation rate strictly less than 0.01 mg/cm²/min.

To measure this evaporation rate, 15 g of oil or oil mixture to be tested are placed in a crystallizing dish 7 cm in diameter, placed on a balance that is in a large chamber of about 0.3 m³ which is temperature-regulated, at a temperature of 25°C, and hygrometry-regulated, at a relative humidity of 50%. The liquid is allowed to evaporate freely, without stirring it, while providing ventilation by means of a fan (Papst-Motoren, reference 8550 N, rotating at 2700 rpm) placed in a vertical position above the crystallizing dish containing said oil or said mixture, the blades being directed towards the crystallizing dish, 20 cm away from the bottom of the crystallizing dish. The mass of oil remaining in the crystallizing dish is measured at regular intervals. The evaporation rates are expressed in mg of oil evaporated per unit of area (cm²) and per unit of time (minutes).

According to one particular embodiment, the composition according to the invention comprises a gel of silicone elastomer dispersed in a silicone oil chosen from a non- exhaustive list comprising cyclopentadimethylsiloxane, dimethicones, dimethylsiloxanes, methyltrimethicone, phenylmethicone, phenyldimethicone, phenyltrimethicone, and cyclomethicone.

According to one preferred embodiment, the composition according to the invention comprises a gel of silicone elastomer dispersed in a linear silicone oil chosen from polydimethylsiloxanes (PDMSs) or dimethicones having a viscosity at 25°C ranging from 1 to 500 cSt at 25°C, which are optionally modified with optionally fluorinated, aliphatic groups, or with functional groups such as hydroxyl, thiol and/or amine groups.

In particular, mention may be made of:

- PDMSs comprising alkyl or alkoxy groups, which are pendent and/or at the end of the silicone chain, these groups each containing from 2 to 24 carbon atoms,

- PDMSs comprising aliphatic groups, or functional groups such as hydroxyl, thiol and/or amine groups,

- polyalkylmethylsiloxanes optionally substituted with a fluorinated group, such as polymethyltrifluoropropyldimethylsiloxanes, - polyalkylmethylsiloxanes substituted with functional groups such as hydroxyl, thiol and/or amine groups,

- polysiloxanes modified with fatty acids, fatty alcohols or polyoxyalkylenes, and mixtures thereof.

According to one embodiment, a composition according to the invention contains at least one polydimethylsiloxane linear silicone oil not modified with pendent groups.

As elastomers in acordance with the invention, mention may especially be made of the compounds having the INCI names below:

- DIMETHICONE/VINYL DIMETHICONE CROSSPOLYMER, such as USG-105 and USG-107A from the company Shin Etsu; DC9506 and DC9701 from the company Dow Corning,

- DIMETHICONE/VINYL DIMETHICONE CROSSPOLYMER (and) DIMETHICONE, such as KSG-6 and KSG-16 from the company Shin Etsu;

- DIMETHICONE/VINYL DIMETHICONE CROSSPOLYMER (and) CYCLOPENTASILOXANE, such as KSG-15,

- CYCLOPENTASILOXANE (and) DIMETHICONE CROSSPOLYMER, such as DC9040, DC9045 and DC5930 from the company Dow Corning,

- DIMETHICONE (and) DIMETHICONE CROSSPOLYMER, such as DC9041 from the company Dow Corning,

- C4-24 ALKYL DIMETHICONE/DIVINYL DIMETHICONE CROSSPOLYMER, such as NuLastic Silk MA from the company Alzo.

According to one particular embodiment of the invention, said silicone elastomer is dispersed in a linear silicone oil.

As examples of silicone elastomers dispersed in a linear silicone oil that can be used according to the invention, mention may especially be made of the following references:

- DIMETHICONE (and) DIMETHICONE CROSSPOLYMER, such as DC9041 from the company Dow Corning, According to one particular embodiment, said silicone elastomer is crosslinked with hexadiene.

As examples of silicone elastomers crosslinked with hexadiene that can be used according to the invention, mention may especially be made of the following references: - MIXTURE OF POLYDIMETHYLSILOXANE CROSSLINKED WITH HEXADIENE/POLY- DIMETHYLSILOXANE (5 cSt) sold under the name DC 9041 by DOW CORNING

- MIXTURE OF POLYDIMETHYLSILOXANE CROSSLINKED WITH HEXADIENE/ CYCLOPENTADIMETHYLSILOXANE sold under the names DC 9040 or DC5930 by DOW CORNING

- MIXTURE OF POLYDIMETHYLSILOXANE CROSSLINKED WITH HEXADIENE/ CYCLOPENTADIMETHYLSILOXANE sold under the name DC 9045 by DOW CORNING

According to one particularly preferred embodiment, the composition according to the invention comprises at least one crosslinked silicone elastomer having the I NCI name 'dimethicone (and) dimethicone crosspolymer', with preferably a dimethicone having a viscosity ranging from 1 to 100 cSt, in particular from 1 to 10 cSt at 25°C, such as the MIXTURE OF POLYDIMETHYLSILOXANE CROSSLINKED WITH HEXADIENE/POLY- DIMETHYLSILOXANE (5 cSt) sold under the name DC 9041 DOW CORNING.

In particular, the crosslinked silicone elastomer is present in the composition in a content, of active material, ranging from 5% to 22% by weight, especially from 6% to 18% by weight, in particular from 7% to 15% by weight and preferably from 8% to 12% by weight of active material relative to the total weight of said composition.

According to one particular embodiment of the invention, the weight ratio between the crosslinked silicone elastomer by weight of active material and the volatile linear alkane will be greater than or equal to 0.1 , and will advantageously range from 0.2 to 3, especially from 0.3 to 1 , preferably from 0.3 to 0.8.

According to one particular embodiment, the composition according to the invention comprises less than 10% by weight of cyclic silicone oil, in particular less than 5% by weight, preferably less than 1 % and better still less than 0.1 % by weight of cyclic silicone oil. GALENIC FORM

FATTY PHASE

The composition according to the invention comprises a liquid and/or solid continuous fatty phase.

The fatty phase is generally present in a composition according to the invention in a content ranging from 1 % to 95% by weight, preferably ranging from 5% to 90% by weight and preferentially ranging from 10% to 85% by weight relative to the total weight of the composition.

The fatty phase of a composition according to the invention comprises at least one or more volatile linear C7-C15 alkanes as defined above and may also comprise one or more additional oils or organic solvents.

Additional oils

For the purposes of the patent application, the term "oil or organic solvent" means a non-aqueous substance, which is liquid at room temperature (25°C) and atmospheric pressure (760 mmHg).

The additional oil may be chosen from volatile oils and/or non-volatile oils, and mixtures thereof.

The additional oil(s) may be present in a content ranging from 0 to 40% by weight and preferably from 0 to 20% by weight relative to the total weight of the composition.

According to one particular embodiment, the composition does not contain any additional oil.

According to one particular embodiment, a composition according to the invention comprises at least one additional volatile oil.

For the purposes of the invention, the term "volatile oil" means an oil that is capable of evaporating on contact with the keratin materials in less than one hour, at room temperature and atmospheric pressure. The volatile organic solvent(s) and volatile oils of the invention are volatile organic solvents and cosmetic oils that are liquid at room temperature, with a non-zero vapour pressure at room temperature and atmospheric pressure, ranging in particular from 0.13 Pa to 40 000 Pa (10^"3 to 300 mmHg), in particular ranging from 1.3 Pa to 13 000 Pa (0.01 to 100 mmHg), and more particularly ranging from 1.3 Pa to 1300 Pa (0.01 to 10 mmHg). In particular, the volatile oils are chosen from the oils having an evaporation rate greater than or equal to 0.002 mg/cm²/min. The evaporation rate is measured as follows:

15 g of oil or mixture of oils to be tested are placed in a crystallizing dish (diameter: 7 cm) placed on a balance that is in a chamber of about 0.3 m3 which is temperature-regulated (25°C) and hygrometry-regulated (50% relative humidity).

The liquid is allowed to evaporate freely, without stirring it, while providing ventilation by means of a fan (rotational speed of 2700 rpm and dimensions of 80 ^χ 80 ^χ 42 mm, for example reference 8550 N from Papst-Motoren, the flow rate corresponds to around 50 m³/hour) placed vertically above the crystallizing dish containing the solvent, the blades being directed toward the crystallizing dish, 20 cm away from the bottom of the crystallizing dish.

The mass of oil remaining in the crystallizing dish is measured at regular intervals. The evaporation rates are expressed in mg of oil evaporated per unit of area (cm²) and per unit of time (minutes).

The term "non-volatile oil" means an oil that remains on keratin materials, at room temperature and atmospheric pressure, for at least several hours and that especially has a vapour pressure of less than 10^"3 mmHg (0.13 Pa).

These oils may be hydrocarbon-based oils, silicone oils or fluoro oils, or mixtures thereof.

The term "hydrocarbon-based oil" means an oil mainly containing hydrogen and carbon atoms and optionally oxygen, nitrogen, sulphur or phosphorus atoms. The volatile hydrocarbon-based oils may be chosen from hydrocarbon-based oils containing from 8 to 16 carbon atoms, and especially branched C₈-Ci₆ alkanes, for instance C₈-Ci₆ isoalkanes of petroleum origin (also known as isoparaffins), for instance isododecane (also known as 2,2,4,4,6-pentamethylheptane), isodecane and isohexadecane, and for example the oils sold under the trade names Isopar or Permethyl, branched C₈-Ci₆ esters and isohexyl neopentanoate, and mixtures thereof. Other volatile hydrocarbon-based oils, for instance petroleum distillates, especially those sold under the name Shell Solt by the company Shell, may also be used. The volatile solvent is preferably chosen from volatile hydrocarbon-based oils containing from 8 to 16 carbon atoms, and mixtures thereof.

Volatile oils that may also be used include volatile silicones, or volatile silicone oils, for instance volatile linear or cyclic silicone oils, especially those having a viscosity < 8 centistokes (8 ^χ 10^"6 m²/s) and especially containing from 2 to 7 silicon atoms, these silicones optionally comprising alkyl or alkoxy groups containing from 1 to 10 carbon atoms. As volatile silicone oils that may be used in the invention, mention may be made especially of octamethylcyclotetrasiloxane, cyclopentadimethylsiloxane, decamethyl- cyclopentasiloxane, dodecamethylcyclohexasiloxane, heptamethylhexyltrisiloxane, heptamethyloctyltrisiloxane, hexamethyldisiloxane, octamethyltrisiloxane, decamethyltetrasiloxane and dodecamethylpentasiloxane, and mixtures thereof.

Volatile fluoro solvents such as nonafluoromethoxybutane or perfluoromethylcyclopentane may also be used.

The composition may also comprise at least one non-volatile oil or organic solvent chosen especially from non-volatile hydrocarbon-based oils and/or silicone oils and/or fluoro oils.

Non-volatile hydrocarbon-based oils that may especially be mentioned include:

- hydrocarbon-based oils of plant origin, such as fatty acid triesters of glycerol, the fatty acids of which may have chain lengths varying from C₄ to C₂₄, these chains possibly being linear or branched, and saturated or unsaturated; these oils are especially wheatgerm oil, sunflower oil, grapeseed oil, sesame seed oil, corn oil, apricot oil, castor oil, shea oil, avocado oil, olive oil, soybean oil, sweet almond oil, palm oil, rapeseed oil, cottonseed oil, hazelnut oil, macadamia oil, jojoba oil, alfalfa oil, poppy oil, pumpkin oil, sesame seed oil, marrow oil, rapeseed oil, blackcurrant oil, evening primrose oil, millet oil, barley oil, quinoa oil, rye oil, safflower oil, candlenut oil, passion flower oil and musk rose oil; or alternatively caprylic/capric acid triglycerides such as those sold by the company Stearineries Dubois or those sold under the names Miglyol 810, 812 and 818 by the company Dynamit Nobel;

- synthetic ethers containing from 10 to 40 carbon atoms;

- linear or branched hydrocarbons of mineral or synthetic origin, such as petroleum jelly, polydecenes, hydrogenated polyisobutene such as Parleam, and squalane, and mixtures thereof;

- synthetic esters such as oils of formula F^COORa in which represents a linear or branched fatty acid residue containing from 1 to 40 carbon atoms and R₂ represents an in particular branched hydrocarbon-based chain containing from 1 to 40 carbon atoms, on condition that + R₂ > 10, for instance purcellin oil (cetostearyl octanoate), isopropyl myristate, isopropyl palmitate, C₁₂ to Ci₅ alkyl benzoate, hexyl laurate, diisopropyl adipate, isononyl isononanoate, 2-ethylhexyl palmitate, isostearyl isostearate, alkyl or polyalkyl octanoates, decanoates or ricinoleates such as propylene glycol dioctanoate; hydroxylated esters such as isostearyl lactate and diisostearyl malate; and pentaerythritol esters; - fatty alcohols that are liquid at room temperature, with a branched and/or unsaturated carbon-based chain containing from 12 to 26 carbon atoms, for instance octyldodecanol, isostearyl alcohol, oleyl alcohol, 2-hexyldecanol, 2-butyloctanol and 2- undecylpentadecanol; and

- higher fatty acids such as oleic acid, linoleic acid or linolenic acid;

- carbonates;

- acetates;

- citrates;

- and mixtures thereof.

The non-volatile silicone oils that can be used in the composition according to the invention may be non-volatile polydimethylsiloxanes (PDMSs), polydimethylsiloxanes comprising alkyl or alkoxy groups, that are pendent and/or at the end of a silicone chain, the groups each containing from 2 to 24 carbon atoms, phenyl silicones, for instance phenyl trimethicones, phenyl dimethicones, phenyltrimethylsiloxydiphenylsiloxanes, diphenyl dimethicones, diphenylmethyldiphenyltrisiloxanes and 2-phenylethyl trimethylsiloxysilicates.

The fluoro oils that can be used in the invention are especially fluorosilicone oils, fluoro polyethers and fluorosilicones as described in document EP-A-847 752.

The composition according to the invention may also comprise, besides the silicone elastomer(s) in accordance with the invention, at least one agent chosen from lipophilic thickeners, lipophilic structuring agents, and mixtures thereof.

PUL VERULENT MA TERIALS

The composition according to the invention may also comprise at least pulverulent materials.

The term "pulverulent materials" is intended to mean any particles of dyestuff and/or filler type, as defined hereinafter.

In particular, the composition comprises at least one pulverulent material chosen from pigments, nacres and fillers, and mixtures thereof, in particular pigments.

The pulverulent materials are present in the composition in a content ranging from 0 to

50% by weight, in particular from 1 % to 20% by weight, and especially from 2% to 10% by weight, relative to the total weight of said composition.

Said pulverulent materials are dispersed in a homogeneous and stabilized form. According to one embodiment, the composition of the invention comprises at least one filler.

FILLERS

A composition in accordance with the invention may also comprise at least one filler of organic or mineral nature.

The term "filler" should be understood to mean colourless or white solid particles of any shape which are in a form that is insoluble and dispersed in the medium of the composition. They are mineral or organic in nature and make it possible to confer softness and mattness on the composition and a uniform makeup result.

The fillers may be present in the emulsion in a content ranging from 0.2% to 10% by weight, relative to the total weight of the emulsion, preferably 0.5% to 5% by weight, relative to the total weight of said composition.

The fillers used in the compositions according to the present invention may be in lamellar, globular or spherical form, in the form of fibres or in any other intermediate form between these defined forms.

The fillers according to the invention may or may not be surface-coated, and in particular they may be surface-treated with silicones, amino acids, fluoro derivatives or any other substance that promotes the dispersion and compatibility of the filler in the composition.

Among the mineral fillers that can be used in the compositions according to the invention, mention may be made of talc, mica, silica, trimethyl siloxysilicate, kaolin, bentone, calcium carbonate, magnesium hydrogen carbonate, hydroxyapatite, boron nitride, hollow silica microspheres (Silica Beads from Maprecos), glass or ceramic microcapsules, silica-based fillers, for instance Aerosil 200 or Aerosil 300; Sunsphere H- 33 and Sunsphere H-51 sold by Asahi Glass; Chemicelen sold by Asahi Chemical; composites of silica and of titanium dioxide, for instance the TSG series sold by Nippon Sheet Glass, and mixtures thereof.

Among the organic fillers that can be used in the compositions according to the invention, mention may be made of polyamide powders (Nylon® Orgasol from Atochem), poly^-alanine and polyethylene powders, polytetrafluoroethylene (Teflon^®) powders, lauroyllysine, starch, tetrafluoroethylene polymer powders, hollow polymer microspheres, such as EXPANCEL (NOBEL INDUSTRIE), metal soaps derived from organic carboxylic acids containing from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, for example zinc stearate, magnesium stearate or lithium stearate, zinc laurate, magnesium myristate, Polypore L 200 (Chemdal Corporation), silicone resin microbeads (Tospearl^® from Toshiba, for example), polyurethane powders, in particular powders of crosslinked polyurethane comprising a copolymer, said copolymer comprising trimethylol hexyllactone, for instance the hexamethylene diisocyanate/trimethylol hexyllactone polymer sold under the name Plastic Powder D-400® or Plastic Powder D- 800® by the company Toshiki, carnauba microwaxes, such as the product sold under the name MicroCare 350® by the company Micro Powders, microwaxes of synthetic wax, such as the product sold under the name MicroEase 114S® by the company Micro Powders, microwaxes constituted of a mixture of carnauba wax and of polyethylene wax, such as those sold under the names MicroCare 300® and 310® by the company Micro Powders, microwaxes constituted of a mixture of carnauba wax and of synthetic wax, such as the product sold under the name MicroCare 325® by the company Micro Powders, polyethylene microwaxes, such as those sold under the names Micropoly 200®, 220®, 220L® and 250S® by the company Micro Powders; fibres of synthetic or natural and mineral or organic origin. They may be short or long, individual or organized, for example braided, and hollow or solid. They may have any shape and may especially have a circular or polygonal (square, hexagonal or octagonal) cross section depending on the specific application envisaged. In particular, their ends are blunted and/or polished to prevent injury. The fibres have a length ranging from 1 μηι to 10 mm, preferably from 0.1 mm to 5 mm and better still from 0.3 mm to 3 mm. Their cross section may be included in a circle with a diameter ranging from 2 nm to 500 μηι, preferably ranging from 100 nm to 100 μηι and better still from 1 μηι to 50 μηι. As fibres that can be used in the compositions according to the invention, mention may be made of non-rigid fibres such as polyamide (Nylon^®) fibres or rigid fibres such as polyimideamide fibres, for instance those sold under the names Kermel^® and Kermel Tech^® by the company Rhodia or poly(p-phenyleneterephthalamide) (or aramid) fibres sold especially under the name Kevlar^® by the company DuPont de Nemours,

and mixtures thereof, According to one embodiment, the composition of the invention comprises at least one pulverulent dystuff, in particular at least one pigment.

PULVERULENT DYESTUFFS

The pulverulent dyestuffs may be present in a proportion of from 0 to 30% by weight, especially from 1 % to 20% by weight, and in particular from 2% to 15% by weight, relative to the total weight of the cosmetic composition. The pulverulent dyestuffs are in particular chosen from organic or inorganic pulverulent dyestuffs, in particular of pigment or nacre type, materials with a specific optical effect, and mixtures thereof.

According to one particular embodiment, the pulverulent dyestuffs are surface-treated with a hydrophobic agent. The hydrophobic treatment agent may be chosen from silicones such as methicones, dimethicones and perfluoroalkylsilanes; fatty acids such as stearic acid; metal soaps such as aluminium dimyristate, the aluminium salt of hydrogenated tallow glutamate, perfluoroalkyl phosphates, perfluoroalkylsilanes, perfluoroalkylsilazanes, polyhexafluoropropylene oxides, polyorganosiloxanes comprising perfluoroalkyl perfluoropolyether groups, amino acids; N-acylamino acids or salts thereof; lecithin, isopropyl triisostearyl titanate, and mixtures thereof. Pigments

The term "pigments" should be understood to mean white or coloured, mineral or organic particles which are insoluble in an aqueous solution, and which are intended to colour and/or opacify the resulting film.

As mineral pigments that can be used in the invention, mention may be made of titanium oxides, zirconium oxides or cerium oxides, and also zinc oxides, iron oxides or chromium oxides, ferric blue, manganese violet, ultramarine blue and chromium hydrate.

Iron oxide or titanium dioxide pigments are preferably used.

It may also be a pigment having a structure that may be, for example, of sericite/brown iron oxide/titanium dioxide/silica type. Such a pigment is sold, for example, under the reference Coverleaf NS or JS by the company Chemicals and Catalysts, and has a contrast ratio in the region of 30.

The dyestuff may also comprise a pigment having a structure which may be, for example, of the type such as silica microspheres containing iron oxide. An example of a pigment having this structure is the product sold by the company Miyoshi under the reference PC Ball PC-LL-100 P, this pigment being constituted of silica microspheres containing yellow iron oxide.

Among the organic pigments that may be used in the invention, mention may be made of carbon black, pigments of D&C type, lakes based on cochineal carmine or on barium, strontium, calcium or aluminium, or alternatively the diketopyrrolopyrroles (DPP) described in documents EP-A-542 669, EP-A-787 730, EP-A-787 731 and WO-A-

96/08537. Advantageously, the pigments may be present in a hydrophobic coated form in the emulsion according to the invention. They are more particularly pigments surface- treated with a hydrophobic agent to make them compatible with the fatty phase of the composition, especially so that they have good wettability with the oils of the fatty phase. Thus, these treated pigments are well dispersed in the fatty phase.

The hydrophobic treatment agent may be chosen from silicones such as methicones, dimethicones and perfluoroalkylsilanes; fatty acids such as stearic acid; metal soaps such as aluminium dimyristate, the aluminium salt of hydrogenated tallow glutamate, perfluoroalkyl phosphates, perfluoroalkylsilanes, perfluoroalkylsilazanes, polyhexafluoropropylene oxides, polyorganosiloxanes comprising perfluoroalkyl perfluoropolyether groups, amino acids, N-acylamino acids or salts thereof; lecithin, isopropyl triisostearyl titanate, and mixtures thereof.

The N-acylamino acids may comprise an acyl group containing from 8 to 22 carbon atoms, for instance a 2-ethylhexanoyl, caproyl, lauroyl, myristoyl, palmitoyl, stearoyl or cocoyl group. The salts of these compounds may be the aluminium, magnesium, calcium, zirconium, zinc, sodium or potassium salts. The amino acid may be, for example, lysine, glutamic acid or alanine.

The term "alkyl" mentioned in the compounds cited above especially denotes an alkyl group containing from 1 to 30 carbon atoms and preferably containing from 5 to 16 carbon atoms.

Hydrophobically treated pigments are described especially in patent application EP-A-1 086 683. Nacres

The term "nacres" should be understood as meaning iridescent or non- iridescent coloured particles of any form, especially produced by certain molluscs in their shell or alternatively synthesized, which have a colour effect via optical interference.

The nacres may be chosen from nacreous pigments such as titanium mica coated with an iron oxide, titanium mica coated with bismuth oxychloride, titanium mica coated with chromium oxide, titanium mica coated with an organic dye and also nacreous pigments based on bismuth oxychloride. They may also be mica particles at the surface of which are superposed at least two successive layers of metal oxides and/or of organic dyestuffs.

Examples of nacres that may also be mentioned include natural mica coated with titanium oxide, with iron oxide, with natural pigment or with bismuth oxychloride. Materials with an optical effect

The cosmetic composition according to the invention may also contain at least one material with a specific optical effect.

This effect is different from a simple conventional hue effect, i.e. a unified and stabilized effect as produced by standard dyestuffs, for instance monochromatic pigments. For the purposes of the invention, the term "stabilized" means lacking an effect of variability of the colour as a function of the angle of observation or alternatively in response to a temperature change.

For example, this material may be chosen from particles with a metallic tint, goniochromatic colouring agents, diffracting pigments, thermochromic agents, optical brighteners, and also fibres, especially interference fibres. Needless to say, these various materials may be combined so as to afford the simultaneous manifestation of two effects, or even of a novel effect in accordance with the invention.

The particles with a metallic tint that can be used in the invention are in particular chosen from:

particles of at least one metal and/or of at least one metal derivative, particles comprising a single-material or multi-material organic or mineral substrate, at least partially coated with at least one coat with a metallic tint comprising at least one metal and/or at least one metal derivative, and - mixtures of said particles.

Among the metals that may be present in said particles, mention may be made, for example, of Ag, Au, Cu, Al, Ni, Sn, Mg, Cr, Mo, Ti, Zr, Pt, Va, Rb, W, Zn, Ge, Te and Se, and mixtures or alloys thereof. Ag, Au, Cu, Al, Zn, Ni, Mo and Cr and mixtures or alloys thereof (for example bronzes and brasses) are preferred metals.

The term "metal derivatives" is intended to denote compounds derived from metals, especially oxides, fluorides, chlorides and sulphides.

The goniochromatic colouring agent may be chosen, for example, from multilayer interference structures and liquid-crystal colouring agents.

Cosmetic adjuvants

The compositions of the invention may also contain one or more of the adjuvants that are customary in the cosmetics and dermatological fields, such as moisturizing agents; emollients; hydrophilic or lipophilic active agents; free-radical scavengers; sequestering agents; antioxidants; preservatives; alkalinizing or acidifying agents; fragrances; hydrophilic gelling agents; film-forming agents, in particular film-forming polymers (for compositions in a sustained direction), organic or physical sunscreens, water-soluble or fat-soluble dyes; and mixtures thereof. The amounts of these various adjuvants are those conventionally used in foundations. Needless to say, a person skilled in the art will take care to select the optional adjuvant(s) added to the composition according to the invention, such that the advantageous properties intrinsically associated with the composition in accordance with the invention are not, or are not substantially, adversely affected by the envisioned addition.

The invention is illustrated, in the example presented below, as a non-limiting illustration of the field of the invention. The values are expressed therein as % by weight relative to the total weight of the composition.

EXAMPLES

Example 1 : Effect of the combination according to the invention on the viscosity of the composition

Simple formulations were prepared, comprising, as the sole ingredients:

10.5% by weight of active material of a crosslinked silicone elastomer in the form of gels in which the crosslinked silicone elastomer is respectively dispersed in a cyclic silicone oil (test 1 according to the invention) or in a linear silicone oil (test 3 according to the invention) and

oils, respectively volatile linear alkanes according to the invention (tests

1 and 3) or a cyclic silicone oil (comparative tests 2 and 4).

Preparation method: the elastomer gel is weighed into a beaker, the oily solvent is added little by little while mixing using a spatula. The whole assembly is mixed in a Rayneri mixer fitted with a deflocculator.

The viscosity of said compositions thus prepared was then measured, after 24 h at rest, on a Rheomat 180 (LAMY) using an M4 spindle, at 25°C, after 10 min of shear at 200 rpm.

The compositions and viscosity results are presented in Table 1 below. Table 1

application WO 2008/155059. The viscosity measurements show that the use of volatile linear alkanes in combination with silicone elastomers in a high content (10.5% by weight of active material) makes it possible to reduce the viscosity of the composition, compared to the same composition with a cyclic silicone oil.

The reduction in the viscosity of the compositions is even better (viscosity is reduced by half) with the combination 'volatile linear alkanes and silicone elastomer dispersed in a linear silicone oil (DOW CORNING 9041 SILICONE ELASTOMER BLEND)', compared to the combination of a volatile linear alkane with a silicone elastomer dispersed in a cyclic silicone oil (DOW CORNING 9045 SILICONE ELASTOMER BLEND) (viscosity is reduced by a third).

These results therefore show the particular and unexpected effect of the combination of a volatile linear alkane and of a gel of crosslinked silicone elastomer, on the fluidity of the compositions, thus making it possible to incorporate, at equivalent viscosity, a larger amount of silicone elastomer while retaining or improving the application properties (spreading over the skin).

Example 3: Formulations

The following compositions are prepared according to conventional methods.

MAKEUP BASE DIMETHICONE (and)

DIMETHICONE CROSSPOLYMER- (DC9041 from Dow Corning) 70% DODECANE (PARAFOL 12-97 from SASOL) 30%

FOUNDATION 1

DIMETHICONE (and)

DIMETHICONE CROSSPOLYMER- (DC9041 from Dow Corning) 64%

DODECANE (PARAFOL 12-97 from SASOL) 24%

COATED PIGMENTS (NAI COATED PIGMENT from MYOSHI) 10%

SUNSCREEN 2% FOUNDATION 2

CYCLOPENTASI LOXAN E (and)

DIMETHICONE CROSS POLYMER (DC9045 from DOW CORNING) 64% DODECANE (PARAFOL 12-97 from Sasol) 4% COATED PIGMENTS (PF PIGMENTS from DAITO KASEI KOGYO) 10% SILSESQUIOXANE CROSSPOLYMER (KSP 100 from SHIN ETSU) 2%

FOUNDATION 3

DIMETHICONE (and)

DIMETHICONE CROSSPOLYMER- (DC9041 from Dow Corning) 64%

UNDECANE/TRIDECANE* MIXTURE 24%

COATED PIGMENTS (NAI COATED PIGMENT from MYOSHI) 10%

SUNSCREEN 2%

* predominant undecane/tridecane mixture as prepared according to patent application WO 2008/155059.

For the preparation of the compositions of these foundations, the pigments are made into a paste with a portion of the oil and ground three times in a three-roll mill. The ground pigment material is then added to the mixture of elastomers + oil while stirring using a Rayneri mixer fitted with a deflocculator.

DAY CREAM

GLYCEROL 15% NULASTIC SILK MA, DM-6 ALZO (C4-24 ALKYL DIMETHICONE/DIVINYL

DIMETHICONE CROSSPOLYMER) 65% TETRADECANE (PARAFOL 14-97 from SASOL) 20%

DRY ENDS HAIR SERUM

DODECANE(PARAFOL 12-97 from SASOL) 15%

UNDECANE/TRIDECANE MIXTURE* 34%

DIMETHICONE/VINYL DIMETHICONE CROSSPOLYMER USG 107A 50%

FRAGRANCE 1 % * predominant undecane/tridecane mixture as prepared according to patent application WO 2008/155059.

Claims

1. Anhydrous cosmetic composition for caring for and/or making up keratin materials, in particular the skin, comprising, in a physiologically acceptable medium:

(i) one or more crosslinked silicone elastomers in a total content, of active material, of greater than or equal to 5% by weight relative to the total weight of said composition,

(ii) one or more volatile linear alkanes, especially C7-C15 alkanes, in a total content of greater than or equal to 5% by weight relative to the total weight of said composition, and

(iii) at least one additional cosmetic ingredient.

2. Anhydrous cosmetic composition according to Claim 1 , characterized in that the crosslinked silicone elastomer(s) is (are) present in the composition in a content, of active material, ranging from 5% to 22% by weight, especially from 6% to 18% by weight, in particular from 7% to 15% by weight and preferably from 8% to 12% by weight of active material relative to the total weight of said composition.

3. Anhydrous cosmetic composition according to either of Claims 1 and 2, characterized in that the silicone elastomer is in the form of a gel of crosslinked silicone elastomer dispersed in a silicone oil.

4. Anhydrous cosmetic composition according to the preceding claim, characterized in that the crosslinked silicone elastomer is in the form of a gel of crosslinked silicone elastomer dispersed in a cyclic silicone oil.

5. Anhydrous cosmetic composition according to Claim 3, characterized in that the crosslinked silicone elastomer is in the form of a gel of crosslinked silicone elastomer dispersed in a linear silicone oil, in particular having a viscosity ranging from 1 to 500 centistokes (cSt) at 25°C, in particular from 2 to 350 cSt, especially from 2 to 100 cSt and in particular from 2 to 10 cSt, or even from 2 to 6 cSt, limits included.

6. Anhydrous cosmetic composition according to any one of the preceding claims, characterized in that the volatile linear alkane(s) is (are) present in a content ranging from 5% to 50% by weight, especially from 7% to 40% by weight and in particular from 10% to 35% by weight relative to the total weight of the composition.

7. Anhydrous cosmetic composition according to any one of the preceding claims, characterized in that the volatile linear alkane(s) represent(s) from 15% to 100% by weight of the total content of volatile oils in the composition.

8. Composition according to any one of the preceding claims, characterized in that said volatile linear alkane comprises from 7 to 15 carbon atoms, in particular from 9 to 15 carbon atoms, and more particularly from 11 to 15 carbon atoms.

9. Composition according to any one of the preceding claims, characterized in that the volatile linear alkane is chosen from n-heptane, n-octane, n-nonane, n-undecane, n- dodecane, n-tridecane, n-tetradecane and n-pentadecane, and mixtures thereof.

10. Composition according to any one of the preceding claims, characterized in that it comprises at least two different volatile linear alkanes, differing from each other by a carbon number n of at least 1 , in particular differing from each other by a carbon number of 1 or 2.

1 1. Composition according to any one of the preceding claims, characterized in that it comprises a mixture of at least two volatile linear alkanes comprising:

- from 50% to 90% by weight, preferably from 55% to 80% by weight and more preferentially from 60% to 75% by weight of a Cn volatile linear alkane with n ranging from 7 to 15,

from 10% to 50% by weight, preferably from 20% to 45% by weight and preferably from 24% to 40% by weight of a Cn+x volatile linear alkane with x greater than or equal to 1 , preferably x = 1 or x = 2, with n+x between 8 and 15,

relative to the total weight of alkanes in said mixture.

12. Composition according to the preceding claim, characterized in that it comprises an n- undecane/n-tridecane (C11/C13) mixture comprising:

(i) from 55% to 80% by weight and preferably from 60% to 75% by weight of a

C1 1 volatile linear alkane (n-undecane),

(ii) from 20% to 45% by weight and preferably from 24% to 40% by weight of a

C13 volatile linear alkane (n-tridecane),

relative to the total weight of alkanes in said mixture.

13. Composition according to any one of the preceding claims, characterized in that said additional cosmetic ingredient is chosen from oils, thickeners, gelling agents, pulverulent materials, UV screening agents, neutralizing agents, and mixtures thereof.

14. Composition according to any one of the preceding claims, characterized in that it additionally contains pulverulent materials, in particular pulverulent dyestuffs.

15. Cosmetic method for caring for and/or making up keratin materials, in particular the skin, comprising the application to said keratin material of at least one composition as defined in one of Claims 1 to 14.