WO2013057113A2

WO2013057113A2 - Cosmetic composition comprising aerogel silica particles and silicone oils

Info

Publication number: WO2013057113A2
Application number: PCT/EP2012/070508
Authority: WO
Inventors: Claire PELE; Christèle SECLET
Original assignee: L'oreal
Priority date: 2011-10-21
Filing date: 2012-10-16
Publication date: 2013-04-25
Also published as: WO2013057113A3; FR2981571A1; FR2981571B1

Abstract

A subject-matter of the present invention is a cosmetic composition in the form of an oil-in-water emulsion comprising: (1) at least one organopolysiloxane elastomer; (2) at least one hydrophobic silica; and (3) at least one gemini surfactant of formula (I): in which R₁ and R₃ denote, independently of one another, an alkyl radical having from 1 to 25 carbon atoms; R₂ denotes a spacer consisting of a linear or branched alkylene chain having from 1 to 12 carbon atoms; X and Y denote, independently of one another, a -(C₂H₄O)_a-(C₃H₆O)_bZ group; and n ranges from 1 to 10. The composition in accordance with the invention makes it possible to obtain mattifying properties and/or to mask skin imperfections while having good cosmetic properties, such as softness and freshness on application, a non-greasy finish, an ease of penetration and good moisturisation of the skin.

Description

Cosmetic composition comprising aerogel silica particles

and silicone oils

The invention relates to a cosmetic composition for keratinous substances, in particular the skin and the lips, the hair and the nails. The invention also relates to a cosmetic method for treating keratinous substances employing the said composition. In the field of cosmetic skin care compositions, it is known to use soft-focus inorganic or organic fillers which absorb sebum and perspiration, in order to mattify the skin and/or optically smooth the microrelief and conceal skin imperfections.

However, the use of these fillers is generally accompanied by a dry, rough feel and a lack of comfort which is unacceptable to the user.

Silicone elastomers are also widely used as mattifying agent as they make it possible to obtain a soft feel on the skin but have to be used at a relatively high content in order to have the mattifying effect. They are generally formulated in an anhydrous medium and are essentially used as make-up base. This is because the compositions obtained do not exhibit all the sensory characteristics of a care formula, such as freshness on application, ease of penetration, moisturisation or a non-greasy finish.

The need remains to have available cosmetic compositions which are mattifying and/or which make it possible to mask skin imperfections while having good cosmetic properties, in particular which are soft, fresh and non-greasy on application, which easily penetrate and which make possible good moisturisation of the skin.

The Applicant Company has discovered that this need can be met by combining, in a composition of oil-in-water emulsion type, a silicone elastomer, a hydrophobic silica and a gemini surfactant.

More specifically, a subject-matter of the present invention is a cosmetic composition in the form of an oil-in-water emulsion comprising:

(1 ) at least one organopolysiloxane elastomer;

(2) at least one hydrophobic silica; and

(3) at least one gemini surfactant of formula (I):

in which:

- Ri and R3 denote, independently of one another, an alkyl radical having from 1 to 25 carbon atoms;

- R2 denotes a spacer consisting of a linear or branched alkylene chain having from 1 to 12 carbon atoms;

- X and Y denote, independently of one another, a -(C2H₄O)_a-(C3H₆O)_bZ group, where:

• Z denotes a hydrogen atom or a -CH₂-COOM, -SO3M, -P(O)(OM)₂, -C₂H₄- SO3M, -C3H6-SO3M or -CH₂(CHOH)₄CH₂OH radical, where M represents H or an alkali metal or alkaline earth metal or ammonium or alkanolammonium ion,

• a ranges from 0 to 15,

• b ranges from 0 to 10, and

• the sum of a + b ranges from 1 to 25, and

- n ranges from 1 to 10.

As the composition of the invention is intended for a topical application on the skin or superficial body growths, it comprises a physiologically acceptable medium, that is to say a medium compatible with all keratinous substances, such as the skin, nails, mucous membranes and keratinous fibres (such as the hair or eyelashes).

The composition in accordance with the invention makes it possible to obtain mattifying properties and/or to mask skin imperfections while having good cosmetic properties, such as softness and freshness on application, a non-greasy finish, an ease of penetration and good moisturisation of the skin.

Another subject-matter of the present invention is a cosmetic method for making up and/or caring for keratinous substances, comprising a stage of applying a composition as defined above to the said substances.

In that which follows and unless otherwise indicated, the limits of a range of values are included in this range.

Organopolysiloxane elastomer

The composition of the invention comprises at least one organopolysiloxane elastomer, preferably at least partially crosslinked. The term "elastomer" is understood to mean a deformable, flexible solid material having viscoelastic properties and in particular the consistency of a sponge or of a flexible sphere. Its modulus of elasticity is such that this material withstands deformation and has a limited ability to extend and to contract. This material is capable of regaining its original shape after stretching. This elastomer is formed from polymer chains of high molecular weight, the mobility of which is limited by a uniform network of crosslinking points.

The organopolysiloxane elastomers used in the composition according to the invention are preferably partially or completely crosslinked. They are provided in the form of particles. In particular, the organopolysiloxane elastomer particles have a size ranging from 0.1 to 500 μιτι, preferably from 3 to 200 μιτι and better still from 3 to 50 μιτι. These particles can have any shape and can, for example, be spherical, flat or amorphous.

The crosslinked organopolysiloxane elastomer can be obtained by an addition- crosslinking reaction of a diorganopolysiloxane comprising at least one hydrogen atom bonded to a silicon atom and of a diorganopolysiloxane having at least two ethylenically unsaturated groups bonded to separate silicon atoms, in particular in the presence of a platinum catalyst; or by a condensation-crosslinking-dehydrogenation reaction between a hydroxyl-terminated diorganopolysiloxane and a diorganopolysiloxane comprising at least one hydrogen atom bonded to a silicon atom, in particular in the presence of an organotin compound; or by a condensation- crosslinking reaction of a hydroxyl-terminated diorganopolysiloxane and of a hydrolysable organopolysilane; or by thermal crosslinking of organopolysiloxane, in particular in the presence of an organoperoxide catalyst; or by crosslinking of organopolysiloxane by high-energy radiation, such as gamma rays, ultraviolet rays or an electron beam.

Preferably, the crosslinked organopolysiloxane elastomer is obtained by an addition- crosslinking reaction (A) of a diorganopolysiloxane comprising at least one hydrogen atom bonded to a silicon atom, and (B) of a diorganopolysiloxane having at least two ethylenically unsaturated groups each bonded to a separate silicon atom, in particular in the presence (C) of a platinum catalyst, such as, for example, described in Application EP-A-295 886.

The compound (A) is in particular an organopolysiloxane having at least two hydrogen atoms bonded to separate silicon atoms in each molecule.

The compound (A) can exhibit any molecular structure, in particular a linear-chain or branched-chain structure or a cyclic structure. The compound (A) can have a viscosity at 25°C ranging from 1 to 50 000 centistokes, in particular in order to be highly miscible with compound (B).

The organic groups bonded to the silicon atoms of the compound (A) can be 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 groups, such as an epoxy group, a carboxylate ester group or a mercapto group.

The compound (A) can thus be chosen from methylhydropolysiloxanes comprising trimethylsiloxy end groups, dimethylsiloxane-methylhydrosiloxane copolymers comprising trimethylsiloxy end groups, and dimethylsiloxane-methylhydrosiloxane cyclic copolymers.

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

In addition to the abovementioned alkenyl groups, the other organic groups bonded to the silicon atoms in the compound (B) can be 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 groups, such as an epoxy group, a carboxylate ester group or a mercapto group.

The organopolysiloxanes (B) can be chosen from methylvinylpolysiloxanes, methylvinylsiloxane-dimethylsiloxane copolymers, dimethylpolysiloxanes comprising dimethylvinylsiloxy end groups, dimethylsiloxane-methylphenylsiloxane copolymers comprising dimethylvinylsiloxy end groups, dimethylsiloxane-diphenylsiloxane- methylvinylsiloxane copolymers comprising dimethylvinylsiloxy end groups, dimethylsiloxane-methylvinylsiloxane copolymers comprising trimethylsiloxy end groups, dimethylsiloxane-methylphenylsiloxane-methylvinylsiloxane copolymers comprising trimethylsiloxy end groups, methyl(3,3,3-trifluoropropyl)polysiloxanes comprising dimethylvinylsiloxy end groups, and dimethylsiloxane-methyl(3,3,3- trifluoropropyl)siloxane copolymers comprising dimethylvinylsiloxy end groups.

In particular, the organopolysiloxane elastomer can be obtained by reaction of dimethylpolysiloxane comprising dimethylvinylsiloxy end groups and of methylhydropolysiloxane comprising trimethylsiloxy end groups, in the presence of a platinum catalyst.

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

It is advantageous for the compound (A) to be added in an amount such that the molecular ratio of the total amount of hydrogen atoms bonded to silicon atoms in the compound (A) to the total amount of all the ethylenically unsaturated groups in the compound (B) is within the range from 1 .5/1 to 20/1 .

The compound (C) is the catalyst for the crosslinking reaction, and is in particular chloroplatinic acid, chloroplatinic acid-olefin complexes, chloroplatinic acid- alkenylsiloxane complexes, chloroplatinic acid-diketone complexes, platinum black and platinum on a support.

The catalyst (C) is preferably added in a proportion 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 the compounds (A) and (B).

The elastomer obtained can be a non-emulsifying elastomer or an emulsifying elastomer.

The term "non-emulsifying" defines organopolysiloxane elastomers not comprising polyoxyalkylene units. The term "emulsifying" means crosslinked organopolysiloxane elastomers having at least one polyoxyalkylene unit, in particular a polyoxyethylene or polyoxypropylene unit.

The particles of crosslinked organopolysiloxane elastomer can be conveyed in the form of a gel consisting of an elastomeric organopolysiloxane included in at least one hydrocarbon oil and/or one silicone oil. In these gels, the organopolysiloxane particles are often non-spherical particles.

The particles of crosslinked organopolysiloxane elastomer can also be provided in the form of a powder, in particular in the form of a spherical powder. Non-emulsifying elastomers are described in particular 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 Application JP- A-61 -194 009.

Use may be made, as non-emulsifying elastomers, of those sold under the names KSG-6, KSG-15, KSG-16, KSG-18, KSG-31 , KSG-32, KSG-33, KSG-41 , KSG-42, KSG-43 and KSG-44 by Shin-Etsu, DC 9040, DC 9041 , DC 9509, DC 9505 and DC 9506 by Dow Corning, Gransil by Grant Industries and SFE 839 by General Electric.

Advantageously, the emulsifying elastomers comprise polyoxyalkylene-modified elastomers formed from divinyl compounds, in particular polysiloxanes having at least two vinyl groups, reacting with Si-H bonds of a polysiloxane. Emulsifying elastomers are described in particular in Patents US 5 236 986, US 5 412 004, US 5 837 793 and US 5 81 1 487.

Use may be made, as emulsifying elastomers, of those sold under the names KSG- 21 , KSG-20, KSG-30 and X-226146 by Shin-Etsu, and DC9010 and DC901 1 by Dow Corning.

The particles of crosslinked organopolysiloxane elastomer can also be provided in the form of a crosslinked organopolysiloxane elastomer powder coated with silicone resin, in particular silsesquioxane resin, as described, for example, in Patent US 5 538 793. Such elastomers are sold under the names KSP-100, KSP-101 , KSP-102, KSP-103, KSP-104 and KSP-105 by Shin-Etsu.

Other crosslinked organopolysiloxane elastomers in the form of powders can be powders formed of a hybrid silicone functionalized by fluoroalkyl groups, sold in particular under the name KSP-200 by Shin-Etsu, or powders formed of hybrid silicones functionalized by phenyl groups, sold in particular under the name KSP-300 by Shin-Etsu.

Preferably, the composition according to the invention comprises at least one non- emulsifying organopolysiloxane elastomer.

Preferably, the organopolysiloxane elastomer used in the composition of the invention is capable of being obtained by hydrosilylation of polydimethylsiloxanes having vinyl end groups, comprising from 35 to 45 dimethylsiloxane units, with poly(methylhydrosiloxane-dimethylsiloxane)s comprising two methylhydrosiloxane units and from 25 to 35 and more preferably 30 dimethylsiloxane units (such as, for example, KSG-6 from Shin-Etsu). The organopolysiloxane elastomer or elastomers are present in the composition in accordance with the invention in an amount, as active material, which can range, for example, from 2 to 50% by weight, preferably from 5 to 30% by weight and better still from 5 to 20% by weight, of the total weight of the composition.

In particular, the organopolysiloxane elastomer or elastomers are generally present in an amount, as active material, of greater than or equal to 2% by weight, better still of greater than or equal to 5% by weight, of the total weight of the composition.

Hydrophobic silica

The composition comprises one or more hydrophobic silicas. The term "hydrophobic silica" is understood to mean, in the context of the present invention, both pure hydrophobic silicas and particles coated with hydrophobic silica.

According to a specific embodiment, the hydrophobic silicas which can be used in the composition of the invention are amorphous and of fumed origin. They are preferably provided in the pulverulent form.

The amorphous hydrophobic silicas of fumed origin are obtained from hydrophilic silicas. The latter are obtained by pyrolysis of silicon tetrachloride (SiCI₄) in a continuous flame at 1000°C in the presence of hydrogen and oxygen. They are subsequently rendered hydrophobic by treatment with halogenated silanes, alkoxysilanes or silazanes. The hydrophobic silicas differ from the starting hydrophilic silicas, inter alia, in a lower density of silanol groups and in a smaller adsorption of water vapour.

According to this embodiment, the hydrophobic silica is preferably chosen from silicas having a specific surface of from 50 to 500 m²/g and a number-average particle size ranging from 3 to 50 nm. These are more particularly the hydrophobic silicas described in the following table, and their mixtures.

According to this embodiment, the hydrophobic silica used in the composition of the invention can also consist of a particle completely or partially covered with silica, in particular of an inorganic particle completely or partially covered with hydrophobic silica, such as pigments and metal oxides covered with hydrophobic silica. These particles can also have optical properties in the product and on the skin; for example, they can have a mattifying or slightly whitening effect.

Use is preferably made, as hydrophobic silica, of a hydrophobic fumed silica treated at the surface with a dimethylsiloxane, such as that sold under the name Aerosil R972 (INCI name: Silica Dimethyl Silylate) by Evonik Degussa.

According to another specific embodiment, the hydrophobic silicas which can be used in the composition of the invention are aerogel particles of hydrophobic silica exhibiting a specific surface per unit of weight (Sw) ranging from 500 to 1500 m²/g and a size, expressed as volume-average diameter (D[0.5]), ranging from 1 to 1500 μιτι.

Silica aerogels are porous materials obtained by replacing (by drying) the liquid component of a silica gel with air.

They are generally synthesized via a sol-gel process in a liquid medium and then dried, usually by extraction of a supercritical fluid, the one most commonly used being supercritical CO2. This type of drying makes it possible to avoid shrinkage of the pores and of the material. The sol-gel process and the various drying operations are described in detail in Brinker C.J. and Scherer G.W., Sol-Gel Science: New York: Academic Press, 1990.

The aerogel particles of hydrophobic silica used in the present invention exhibit a specific surface per unit of weight (Sw) ranging from 500 to 1500 m²/g, preferably from 600 to 1200 m²/g and better still from 600 to 800 m²/g, and a size, expressed as volume-average diameter (D[0.5]), ranging from 1 to 1500 μιτι, better still from 1 to 1000 μιτι, preferably from 1 to 100 μιτι, in particular from 1 to 30 μιτι, more preferably from 5 to 25 μιτι, better still from 5 to 20 μιτι and even better still from 5 to 15 μιτι. According to one embodiment, the aerogel particles of hydrophobic silica used in the present invention exhibit a size, expressed as volume-average diameter (D[0.5]), ranging from 1 to 30 μιτι, preferably from 5 to 25 μιτι, better still from 5 to 20 μιτι and even better still from 5 to 15 μιτι.

The specific surface per unit of weight can be determined by the nitrogen absorption method, known as the BET (Brunauer-Emmett-Teller) method, described in The Journal of the American Chemical Society, Vol. 60, page 309, February 1938, and corresponding to the international standard ISO 5794/1 (appendix D). The BET specific surface corresponds to the total specific surface of the particles under consideration. The sizes of the aerogel silica particles can be measured by static light scattering using a commercial particle size analyser of MasterSizer 2000 type from Malvern. The data are processed on the basis of the Mie scattering theory. This theory, which is exact for isotropic particles, makes it possible to determine, in the case of non-spherical particles, an "effective" particle diameter. This theory is described in particular in the publication by Van de Hulst, H .C., "Light Scattering by Small Particles", Chapters 9 and 10, Wiley, New York, 1957.

According to an advantageous embodiment, the aerogel particles of hydrophobic silica used in the present invention exhibit a specific surface per unit of weight (Sw) ranging from 600 to 800 m²/g and a size, expressed as volume-average diameter (D[0.5]), ranging from 5 to 20 μιτι and even better still from 5 to 15 μιτι.

The aerogel silica particles used in the present invention can advantageously exhibit a packed density (p) ranging from 0.04 g/cm³ to 0.10 g/cm³ and preferably from 0.05 g/cm³ to 0.08 g/cm³.

In the context of the present invention, this density, known as the packed density, can be assessed according to the following protocol:

40 g of powder are poured into a graduated measuring cylinder; the measuring cylinder is then placed on the Stav 2003 device from Stampf Volumeter; the measuring cylinder is subsequently subjected to a series of 2500 packing actions (this operation is repeated until the difference in volume between two consecutive tests is less than 2%); the final volume Vf of packed powder is then measured directly on the measuring cylinder. The packed density is determined by the ratio w/Vf, in the case in point 40/Vf (Vf being expressed in cm³ and w in g).

According to one embodiment, the aerogel particles of hydrophobic silica used in the present invention exhibit a specific surface per unit of volume Sv ranging from 5 to 60 m²/cm³, preferably from 10 to 50 m²/cm³ and better still from 15 to 40 m²/cm³. The specific surface per unit of volume is given by the relationship: Sv = Sw x p where p is the packed density, expressed in g/cm³, and Sw is the specific surface per unit of weight, expressed in m²/g, as defined above. Preferably, the aerogel particles of hydrophobic silica according to the invention have an oil absorption capacity, measured at the wet point, ranging from 5 to 18 ml/g, preferably from 6 to 15 ml/g and better still from 8 to 12 ml/g.

The absorption capacity measured at the wet point, denoted Wp, corresponds to the amount of oil which it is necessary to add to 100 g of particles in order to obtain a homogeneous paste.

It is measured according to the "wet point" method or method for determining the oil uptake of a powder described in Standard NF T 30-022. It corresponds to the amount of oil adsorbed onto the available surface of the powder and/or absorbed by the powder by measurement of the wet point, described below:

An amount w = 2 g of powder is placed on a glass plate, and the oil (isononyl isononanoate) is then added dropwise. After addition of 4 to 5 drops of oil to the powder, mixing is carried out using a spatula, and addition of oil is continued until conglomerates of oil and powder have formed. From this point, the oil is added at the rate of one drop at a time and the mixture is subsequently triturated with the spatula. The addition of oil is stopped when a firm and smooth paste is obtained. This paste must be able to be spread on the glass plate without cracking or forming lumps. The volume Vs (expressed in ml) of oil used is then noted.

The oil uptake corresponds to the ratio Vs/w.

The aerogels used according to the present invention are hydrophobic silica aerogels, preferably of silylated silica (INCI name: silica silylate).

The term "hydrophobic silica" is understood to mean any silica whose surface is treated with silylating agents, for example with halogenated silanes, such as alkylchlorosilanes, siloxanes, in particular dimethylsiloxanes, such as hexamethyldisiloxane, or silazanes, so as to functionalize the OH groups with silyl groups Si-Rn, for example trimethylsilyl groups.

As regards the preparation of aerogel particles of hydrophobic silica modified at the surface by silylation, reference may be made to the document US 7 470 725.

Use will in particular be made of aerogel particles of hydrophobic silica modified at the surface with trimethylsilyl groups (trimethylsiloxylated silica).

Mention may be made, as hydrophobic silica aerogels which can be used in the invention, for example, of the aerogel sold under the name VM-2260 (INCI name: Silica silylate) by Dow Corning, the particles of which exhibit an average size of approximately 1000 microns and a specific surface per unit of weight ranging from 600 to 800 m²/g.

Mention may also be made of the aerogels sold by Cabot under the references Aerogel TLD 201 , Aerogel OGD 201 and Aerogel TLD 203.

Use will more particularly be made of the aerogel sold under the name VM-2270 (INCI name: Silica silylate) by Dow Corning, the particles of which exhibit an average size ranging from 5 to 15 microns and a specific surface per unit of weight ranging from 600 to 800 m²/g.

The hydrophobic silicas can be present in the composition according to the invention in a content ranging from 0.05 to 15% by weight, preferably from 0.1 to 10% by weight, better still from 0.3 to 5% by weight and more preferably from 0.3 to 1 % by weight, with respect to the total weight of the composition.

Gemini surfactant

The gemini surfactant of formula (I) is preferably such that each of the R1-CO- and R3-CO- groups comprises from 8 to 20 carbon atoms and preferably denotes a coconut fatty acid residue (comprising predominantly lauric acid and myristic acid). In addition, this surfactant is preferably such that, for each of the X and Y radicals, the sum of a and b has a mean value ranging from 10 to 20 and is preferably equal to 15. A preferred group for Z is the -SO3M group, where M is preferably an alkali metal ion, such as a sodium ion.

The spacer R₂ advantageously consists of a linear C1-C3 alkylene chain and preferably of an ethylene (CH₂CH₂) chain.

Finally, n is advantageously equal to 1 .

A surfactant of this type is in particular that identified by the INCI name: Sodium dicocoylethylenediamine PEG-15 sulfate, having the following structure :

H _/(PEG-15)— S0₃Na

cocoyl— C— N

CH₂

I

CH₂

I

cocoyl -C -N __(pEG. J ₅₎ __So₃N_a

O

it being understood that PEG represents the CH₂CH₂O group and cocoyl represents the coconut fatty acid residue. This surfactant has a molecular structure very similar to that of ceramide-3.

Preferably, the gemini surfactant according to the invention is used as a mixture with other surfactants, in particular as a mixture with (a) an ester of a C6-C22 fatty acid (preferably a C14-C20 fatty acid, such as a stearate) and of glycerol, (b) a diester of a C6-C22 fatty acid (preferably a C14-C20 fatty acid, such as a stearate) and of citric acid and of glycerol (in particular a diester of a C6-C22 fatty acid and of glyceryl monocitrate), and (c) a C10-C30 fatty alcohol (preferably behenyl alcohol).

Advantageously, the composition according to the invention comprises a mixture of sodium dicocoylethylenediamine PEG-15 sulfate, of glyceryl stearate, of glyceryl stearate monocitrate and of behenyl alcohol .

More preferentially, the gemini surfactant according to the invention represents from 10 to 20% by weight and advantageously 15% by weight ; the ester of a C6-C22 fatty acid and of glycerol represents from 30 to 40% by weight, advantageously 35% by weight; the diester of a C6-C22 fatty acid and of citric acid and of glycerol represents from 10 to 20% by weight, advantageously 15% by weight; and the C10-C30 fatty alcohol represents from 30 to 40% by weight, advantageously 35% by weight, with respect to the total weight of the mixture of surfactants comprising the gemini surfactant.

Advantageously, the composition according to the invention comprises a mixture of from 10 to 20% by weight of sodium dicocoylethylenediamine PEG-15 sulfate, from 30 to 40% (in particular 35%) by weight of glyceryl stearate, from 10 to 20% (in particular 15%) by weight of glyceryl stearate monocitrate and from 30 to 40% (in particular 35%) by weight of behenyl alcohol, with respect to the total weight of the mixture of surfactants comprising the gemini surfactant.

In an alternative form, the gemini surfactant according to the invention can be used as a mixture with an anionic surfactant, such as an ester of lauric acid, sodium lauroyl lactate. In this case, the gemini surfactant preferably represents from 30 to 50% by weight and the anionic surfactant represents from 50 to 70% by weight, with respect to the total weight of the mixture.

The gemini surfactant can be used, for example, as a mixture with other surfactants in the form of the products sold by Sasol under the Ceralution® names, in particular the following products :

^• Ceralution® H: Behenyl Alcohol, Glyceryl Stearate, Glyceryl Stearate Citrate and Sodium Dicocoylethylenediamine PEG-15 Sulfate, • Ceralution® F: Sodium Lauroyl Lactylate and Sodium Dicocoylethylenediamine PEG-15 Sulfate,

• Ceralution® C: Aqua, Capric/Caprylic triglyceride, Glycerin, Ceteareth-25, Sodium Dicocoylethylenediamine PEG-15 Sulfate, Sodium Lauroyl Lactylate, Behenyl Alcohol, Glyceryl Stearate, Glyceryl Stearate Citrate, Gum Arabic, Xanthan Gum, Phenoxyethanol, Methylparaben, Ethylparaben, Butylparaben, Isobutylparaben (INCI names).

This gemini surfactant represents from 3 to 50% of the weight of these mixtures.

The gemini surfactant of formula (I) can be present in a composition according to the invention in a content ranging from 0.01 to 5% by weight, preferably ranging from 0.1 to 3% by weight and better still ranging from 0.2 to 1 .5% by weight, with respect to the total weight of the composition.

Aqueous phase

The aqueous phase of the composition according to the invention comprises at least water. According to the formulation form of the composition, the amount of aqueous phase can range from 0.1 to 99% by weight, preferably from 0.5 to 98% by weight, better still from 30 to 95% by weight and even better still from 40 to 95% by weight, with respect to the total weight of the composition. This amount depends on the formulation form of the desired composition. The amount of water can represent all or a portion of the aqueous phase and it is generally at least 30% by weight, with respect to the total weight of the composition.

The aqueous phase can comprise at least one hydrophilic solvent, such as, for example, substantially linear or branched lower monoalcohols having from 1 to 8 carbon atoms, such as ethanol, propanol, butanol, isopropanol or isobutanol; polyols, such as propylene glycol, isoprene glycol, butylene glycol, glycerol, sorbitol, polyethylene glycols and their derivatives; and their mixtures.

Fatty phase

The proportion of the fatty phase of the emulsion can range, for example, from 1 to 80% by weight, preferably from 2 to 50% by weight and better still from 5 to 30% by weight, with respect to the total weight of the composition.

This indicated amount does not comprise the content of lipophilic surfactants. The nature of the fatty phase of the emulsion is not critical. The fatty phase can thus consist of any fatty substance conventionally used in the cosmetic or dermatological fields; it comprises in particular at least one oil (fatty substance liquid at 25°C).

Mention may be made, as oils which can be used in the composition of the invention, for example, of:

- hydrocarbon oils of animal origin, such as perhydrosqualene;

- hydrocarbon oils of vegetable origin, such as liquid triglycerides of fatty acids comprising from 4 to 10 carbon atoms, such as heptanoic or octanoic acid triglycerides, or alternatively, for example, sunflower oil, maize oil, soybean oil, cucumber oil, grape seed oil, sesame seed oil, hazelnut oil, apricot oil, macadamia oil, arara oil, castor oil, avocado oil, caprylic/capric acid triglycerides, such as those sold by Stearineries Dubois or those sold under the names Miglyol 810, 812 and 818 by Dynamit Nobel, jojoba oil and shea butter oil;

- synthetic esters and ethers, in particular of fatty acids, such as oils of formulae R^aCOOR^b and R^aOR^b in which R^a represents the residue of a fatty acid comprising from 8 to 29 carbon atoms and R^b represents a branched or unbranched hydrocarbon chain comprising from 3 to 30 carbon atoms, such as, for example, purcellin oil, isononyl isononanoate, isopropyl myristate, 2-ethylhexyl palmitate, 2- octyldodecyl stearate, 2-octyldodecyl erucate or isostearyl isostearate; hydroxylated esters, such as isostearyl lactate, octyl hydroxystearate, octyldodecyl hydroxystearate, diisostearyl malate, triisocetyl citrate, fatty alcohol heptanoates, octanoates and decanoates; polyol esters, such as propylene glycol dioctanoate, neopentyl glycol diheptanoate and diethylene glycol diisononanoate; and pentaerythritol esters, such as pentaerythrityl tetraisostearate;

- substantially linear or branched hydrocarbons of mineral or synthetic origin, such as volatile or non-volatile liquid paraffins, and their derivatives, petrolatum, polydecenes, isohexadecane, isododecane or hydrogenated polyisobutene, such as Parleam ^® oil;

- fatty alcohols having from 8 to 26 carbon atoms, such as cetyl alcohol, stearyl alcohol and their mixture (cetearyl alcohol), octyldodecanol, 2-butyloctanol, 2- hexyldecanol, 2-undecylpentadecanol, oleyl alcohol or linoleyl alcohol;

- alkoxylated and in particular ethoxylated fatty alcohols, such as oleth-12, ceteareth- 12 and ceteareth-20;

- partially hydrocarbon-based and/or silicone-based fluoro oils, such as those described in the document JP-A-2-295 912. Mention may also be made, as fluoro oils, of perfluoromethylcyclopentane and perfluoro-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 3M, or bromoperfluorooctyl, sold under the name Foralkyl® by Atochem; nonafluoromethoxybutane, sold under the name MSX 4518® by 3M, and nonafluoroethoxyisobutane; or perfluoromorpholine derivatives, such as 4- (trifluoromethyl)perfluoromorpholine, sold under the name PF 5052® by 3M.

- silicone oils, such as volatile or non-volatile polymethylsiloxanes (PDMSs) comprising a substantially linear or cyclic silicone chain, which are liquid or pasty at ambient temperature, in particular cyclopolydimethylsiloxanes (cyclomethicones), such as cyclohexadimethylsiloxane and cyclopentadimethylsiloxane; polydimethylsiloxanes comprising alkyl, alkoxy or phenyl groups, which are pendent or at the end of a silicone chain, which groups have from 2 to 24 carbon atoms; or phenylated silicones, such as phenyl trimethicones, phenyl dimethicones, phenyl(trimethylsiloxy)diphenylsiloxanes, diphenyl dimethicones, diphenyl(methyldiphenyl)trisiloxanes, (2-phenylethyl)trimethylsiloxysilicates and polymethylphenylsiloxanes;

- their mixtures.

In the list of the abovementioned oils, the term "hydrocarbon oil" is understood to mean any oil predominantly comprising carbon and hydrogen atoms, and optionally ester, ether, fluoro, carboxylic acid and/or alcohol groups.

The other fatty substances which can be present in the oily phase are, for example, fatty acids comprising from 8 to 30 carbon atoms, such as stearic acid, lauric acid, palmitic acid and oleic acid; waxes, such as lanolin, beeswax, carnauba wax, candelilla wax, paraffin waxes, lignite or microcrystalline waxes, ceresin or ozokerite, or synthetic waxes, such as polyethylene waxes or Fischer-Tropsch waxes; or petrolatum paste.

These fatty substances can be chosen in a way varied by a person skilled in the art so as to prepare a composition having the desired properties, for example of consistency or texture.

In a known way, all the compositions of the invention can comprise one or more of the adjuvants normal in the cosmetic and dermatological fields: hydrophilic or lipophilic gelling agents and/or thickeners; moisturisers; emollients; hydrophilic or lipophilic active agents; agents for combating free radicals; sequestering agents; antioxidants; preservatives; basifying or acidifying agents; fragrances; film-forming agents; fillers; and their mixtures.

The amounts of these various adjuvants are those conventionally used in the fields under consideration. In particular, the amounts of active agents vary according to the desired aim and are those conventionally used in the fields under consideration, for example from 0.1 to 20% and preferably from 0.5 to 10% of the total weight of the composition. Active agents

Mention may be made, as examples of active agents, in a non-limiting way, of ascorbic acid and its derivatives, such as 5,6-di-O-dimethylsilyl ascorbate (sold by Exsymol under the reference PRO-AA), the potassium salt of dl-alpha-tocopheryl 2-1- ascorbyl phosphate (sold by Senju Pharmaceutical under the reference Sepivital EPC), magnesium ascorbyl phosphate or sodium ascorbyl phosphate (sold by Roche under the reference Stay-C 50); phloroglucinol; enzymes; and their mixtures. According to a preferred embodiment of the invention, use is made, among oxidation- sensitive hydrophilic active agents, of ascorbic acid. The ascorbic acid can be of any nature. Thus, it can be of natural origin, in the powder form or in the form of orange juice, preferably orange juice concentrate. It can also be of synthetic origin, preferably in the powder form.

Mention may be made, as other active agents which can be used in the composition of the invention, for example, of moisturising agents, such as protein hydrolysates and polyols, such as glycerol, glycols, such as polyethylene glycols; natural extracts; anti-inflammatories; procyanidol oligomers; vitamins, such as vitamin A (retinol), vitamin B (tocopherol), vitamin B5 (panthenol), vitamin B3 (niacinamide), the derivatives of these vitamins (in particular esters) and their mixtures; urea; caffeine; depigmenting agents, such as kojic acid, hydroquinone and caffeic acid; salicylic acid and its derivatives; alpha-hydroxy acids, such as lactic acid and glycolic acid and their derivatives; retinoids, such as carotenoids and vitamin A derivatives; hydrocortisone; melatonin; extracts of algae, of fungi, of plants, of yeasts or of bacteria; steroids; antibacterial active agents, such as 2,4,4'-trichloro-2'- hydroxydiphenyl ether (or triclosan), 3,4,4'-trichlorocarbanilide (or triclocarban) and the acids indicated above, in particular salicylic acid and its derivatives; mattifying agents, such as fibres; tensioning agents; UV screening agents; fillers; and their mixtures.

Of course, a person skilled in the art will take care to choose the optional adjuvant or adjuvants added to the composition according to the invention so that the advantageous properties intrinsically attached to the composition in accordance with the invention are not, or not substantially, detrimentally affected by the envisaged addition.

The composition according to the invention is provided in the form of a direct (oil-in- water) emulsion with a liquid or semi-liquid consistency of the milk type for example, obtained by dispersion of a fatty phase in an aqueous phase, or of suspensions or emulsions with a soft, semi-solid or solid consistency of the cream or gel type. These compositions are prepared according to the usual methods.

In addition, the composition in accordance with the invention can be more or less fluid and can have the appearance of a gel, a white or coloured cream, an ointment, a milk, a lotion, a serum, a paste or a mousse.

The composition preferably exhibits a skin-friendly pH which generally ranges from 3 to 8 and preferably from 4.5 to 7. The examples which follow will make possible a better understanding of the invention without, however, exhibiting a limiting nature. The starting materials are referred to by their INCI names. Unless otherwise mentioned, the amounts indicated are as % by weight.

Examples

Comparative Examples 1 to 3

The following three compositions were

Phase Compositions 1 2 3

(invention) (invention) (comparative)

A1 Behenyl Alcohol (and) Glyceryl 2 2 2

Stearate (and) Disodium

Ethylene Dicocamide PEG-15

Disulfate (and) Glyceryl

Stearate Citrate, sold under the

name Ceralution H by Sasol

A1 Cetyl Alcohol 0.5 0.5 0.5

A1 Isononyl Isononanoate 4 4 4

A1 Hydrogenated Polyisobutene 3 3 3

A1 Preservative(s) 0.6 0.6 0.6

A2 Dimethicone, sold under the 5 5 5

name Xiameter PMX-200

Silicone Fluid 5CS by Dow

Corning

A2 Silica Silylate, sold under the 0.3

name VM-2270 by Dow Corning

A2 Silica Dimethyl Silylate, sold 1

under the name Aerosil R 972

by Evonik Degussa

A3 Care active agent(s) 1 .2 1 .2 1 .2

B Glycerin 7 7 7

B Sequestering agent(s) 0.1 0.1 0.1

B Water 36.66 35.96 36.96

B Caprylyl Glycol 0.3 0.3 0.3

C Gelling agent(s) 0.25 0.25 0.25 D Water 3 3 3

D Sodium Hydroxide 0.09 0.09 0.09

E Vinyl Dimethicone/Methicone 1 1 1

Silsesquioxane Crosspolymer,

sold under the name KSP 100

by Shin-Etsu

E Polymer(s) 2 2 2

E Silica (and) Polyethylene, sold 2 2 2

under the name Acematt OK

412 by Evonik Degussa

F Dimethicone, sold under the 13 13 13

name Xiameter PMX-200

Silicone Fluid 5CS by Dow

Corning

F Dimethicone/Vinyl Dimethicone 5 5 5

Crosspolymer (and)

Dimethicone, sold under the

name KSG-6 by Shin-Etsu

G Dimethicone (and) Dimethicone 10 10 10

Crosspolymer, sold under the

name DC9041 by Dow Corning

H Denat. Alcohol 3 3 3

Such compositions can be prepared according to the following protocol:

The phase A1 is heated under a magnetic bar up to 70°C. The phases A2 and A3 are then added immediately before emulsification. The phase B is slowly emulsified with regard to the phase A (A1 + A2 +A3) under a turbine mixer and then the power is increased. The phase C is introduced. The power is further increased. Neutralisation is carried out by addition of the phase D. The phase E is added.

The gel phase with the KSG (phase F) is prepared under scraping blades. The phase G and then the phase H are added. The compositions 1 and 2 according to the invention exhibit cosmetic and sensory properties which are better than those of the comparative composition 3, which does not comprise hydrophobic silica. In particular, they exhibit a mat, non-greasy and soft texture on application, with a mattifying and moisturising finish.

Furthermore, the compositions 1 and 2 are stable for two months at ambient temperature and at 45°C.

Comparative Examples 4 and 5

The following two compositions were prepared.

Phase Compositions 4 5

(invention) (comparative)

A1 Behenyl Alcohol (and) Glyceryl Stearate 2

(and) Disodium Ethylene Dicocamide PEG- 15 Disulfate (and) Glyceryl Stearate Citrate,

sold under the name Ceralution H by Sasol

A1 Glyceryl Stearate (and) PEG-100 Stearate, 2

sold under the name Arlacel 165 FL by

Croda

A1 Cetyl Alcohol 0.5 0.5

A1 Isononyl isononanoate 4 4

A1 Hydrogenated polyisobutene 3 3

A1 Preservative(s) 0.6 0.6

A2 Dimethicone, sold under the name Xiameter 5 5

PMX-200 Silicone Fluid 5CS by Dow Corning

A2 Silica Silylate, sold under the name VM-2270 0.3 0.3

by Dow Corning

A3 Active agent(s) 1 .2 1 .2

B Glycerin 7 7

B Sequestering agent(s) 0.1 0.1

B Water 36.66 36.66

B Caprylyl Glycol 0.3 0.3

C Gelling agent(s) 0.25 0.25 D Water 3 3

D Sodium Hydroxide 0.09 0.09

E Vinyl Dimethicone/Methicone Silsesquioxane 1 1

Crosspolymer, sold under the name KSP

100 by Shin-Etsu

E Polymer(s) 2 2

E Silica (and) Polyethylene, sold under the 2 2

name Acematt OK 412 by Evonik Degussa

F Dimethicone, sold under the name Xiameter 13 13

PMX-200 Silicone Fluid 5CS by Dow Corning

F Dimethicone/Vinyl Dimethicone 5 5

Crosspolymer (and) Dimethicone, sold under

the name KSG-6 by Shin-Etsu

G Dimethicone (and) Dimethicone 10 10

Crosspolymer, sold under the name DC9041

by Dow Corning

H Denat. Alcohol 3 3

Such compositions can be prepared according to the following protocol:

The phase A1 is heated under a magnetic bar up to 70°C. The phases A2 and A3 are then added immediately before emulsification. The phase B is slowly emulsified with regard to the phase A (A1 + A2 +A3) under a turbine mixer while increasing the power. The phase C is introduced. The power is further increased. Neutralisation is carried out by addition of the phase D. The phase E is added.

The gel phase with the KSG (phase F) is prepared under scraping blades. The phase G and then the phase H are added.

The composition 4 according to the invention exhibits cosmetic and sensory properties which are better than those of the comparative composition 5, which comprises a different surface-active agent from the gemini surface-active agents of use in the context of the invention. In particular, it is more comfortable and soft on application and it makes it possible to obtain a better mattifying effect on the skin. Furthermore, the composition 4 according to the invention is more stable than the comparative composition 5.

Claims

1 . Cosmetic composition in the form of an oil-in-water emulsion comprising: (1 ) at least one organopolysiloxane elastomer;

(2) at least one hydrophobic silica; and

(3) at least one gemini surfactant of formula (I):

in which:

· Z denotes a hydrogen atom or a -CH₂-COOM, -SO3M, -P(O)(OM)₂, - C₂H₄SO₃M, -C3H6-SO3M or -CH₂(CHOH)₄CH₂OH radical, where M represents H or an alkali metal or alkaline earth metal or ammonium or alkanolammonium ion,

• a ranges from 0 to 15,

• b ranges from 0 to 10, and

· the sum of a + b ranges from 1 to 25, and

- n ranges from 1 to 10.

2. Composition according to Claim 1 , in which the organopolysiloxane or organopolysiloxanes are partially or completely crosslinked.

3. Composition according to Claim 2, in which the crosslinked organopolysiloxane elastomer or elastomers are obtained by an addition-crosslinking reaction (A) of a diorganopolysiloxane comprising at least one hydrogen atom bonded to a silicon atom, preferably chosen from methylhydropolysiloxanes comprising trimethylsiloxy end groups, dimethylsiloxane-methylhydrosiloxane copolymers comprising trimethylsiloxy end groups, and dimethylsiloxane- methylhydrosiloxane cyclic copolymers, and (B) of a diorganopolysiloxane having at least two ethylenically unsaturated groups each bonded to a separate silicon atom, preferably chosen from methylvinylpolysiloxanes, methylvinylsiloxane- dimethylsiloxane copolymers, dimethylpolysiloxanes comprising dimethylvinylsiloxy end groups, dimethylsiloxane-methylphenylsiloxane copolymers comprising dimethylvinylsiloxy end groups, dimethylsiloxane-diphenylsiloxane- methylvinylsiloxane copolymers comprising dimethylvinylsiloxy end groups, dimethylsiloxane-methylvinylsiloxane copolymers comprising trimethylsiloxy end groups, dimethylsiloxane-methylphenylsiloxane-methylvinylsiloxane copolymers comprising trimethylsiloxy end groups, methyl(3,3,3-trifluoropropyl)polysiloxanes comprising dimethylvinylsiloxy end groups, and dimethylsiloxane-methyl(3,3,3- trifluoropropyl)siloxane copolymers comprising dimethylvinylsiloxy end groups.

4. Composition according to any one of Claims 1 to 3, in which the organopolysiloxane elastomer or elastomers are obtained by reaction of dimethylpolysiloxane comprising dimethylvinylsiloxy end groups and of methylhydropolysiloxane comprising trimethylsiloxy end groups, in the presence of a platinum catalyst.

5. Composition according to Claim 4, in which the organopolysiloxane elastomer or elastomers are obtained by hydrosilylation of polydimethylsiloxanes having vinyl end groups, comprising from 35 to 45 dimethylsiloxane units, with poly(methylhydrosiloxane-dimethylsiloxane)s comprising two methylhydrosiloxane units and from 25 to 35 dimethylsiloxane units, preferably 30 dimethylsiloxane units.

6. Composition according to any one of Claims 1 to 5, in which the hydrophobic silica or silicas are chosen from amorphous hydrophobic silicas of fumed origin, preferably treated at the surface with a dimethylsiloxane, and aerogel particles of hydrophobic silica exhibiting a specific surface per unit of weight (Sw) ranging from 500 to 1500 m²/g, preferably from 600 to 1200 m²/g and better still from 600 to 800 m²/g, and a size, expressed as volume-average diameter (D[0.5]), ranging from 1 to 1500 μιτι, preferably from 1 to 1000 μιτι, more preferably still from 1 to 100 μιτι, in particular from 1 to 30 μιτι, more preferably from 5 to 25 μιτι, better still from 5 to 20 μιτι and even better still from 5 to 15 μιτι.

7. Composition according to Claim 6, in which the aerogel particles of hydrophobic silica exhibit a packed density ranging from 0.04 g/cm³ to 0.10 g/cm³ and preferably from 0.05 g/cm³ to 0.08 g/cm³.

8. Composition according to either one of Claims 6 and 7, in which the aerogel particles of hydrophobic silica exhibit a specific surface per unit of volume Sv ranging from 5 to 60 m²/cm³, preferably from 10 to 50 m²/cm³ and better still from 15 to 40 m²/cm³ and/or an oil absorption capacity, measured at the wet point, ranging from 5 to 18 ml/g of particles, preferably from 6 to 15 ml/g and better still from 8 to 12 ml/g.

9. Composition according to one of Claims 6 to 8, in which the aerogel particles of hydrophobic silica are trimethylsiloxylated silica particles.

10. Composition according to any one of Claims 1 to 9, in which each of the Rr CO- and R3-CO- groups comprises from 8 to 20 carbon atoms and preferably denotes a coconut fatty acid residue.

1 1 . Composition according to one of Claims 1 to 10, in which, for the gemini surfactant of formula (I), for each of the X and Y radicals, the sum of a and b has a mean value ranging from 10 to 20.

12. Composition according to any one of Claims 1 to 1 1 , in which, for the gemini surfactant of formula (I), Z is the -SO3M group, where M is an alkali metal ion, such as a sodium ion.

13. Composition according to any one of Claims 1 to 12, in which, for the gemini surfactant of formula (I), n is equal to 1 .

14. Composition according to any one of Claims 1 to 13, in which the surfactant of formula (I) has the following structure:

H _/(PEG- 15)— S0₃Na

cocoyl— C— N

CH₂

I

CH₂

I

cocoyl -C -N __(pEG. J ₅₎ __So₃N_a

O

15. Cosmetic method for making up and/or caring for keratinous substances, comprising a stage of applying a composition according to one of Claims 1 to 14 to the said substances.