WO2013190027A2

WO2013190027A2 - Cosmetic composition comprising hydrophobic silica aerogel particles and a mixture of surfactants

Info

Publication number: WO2013190027A2
Application number: PCT/EP2013/062837
Authority: WO
Inventors: Samira Khenniche; Grégory Plos
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2012-06-21
Filing date: 2013-06-20
Publication date: 2013-12-27
Anticipated expiration: 2014-12-21
Also published as: FR2992175A1; WO2013190027A3; FR2992175B1

Description

Cosmetic composition comprising hydrophobic silica aerogel particles and a mixture of surfactants

The present invention relates to a cosmetic composition, in particular a hair cosmetic composition, comprising the combination of hydrophobic silica aerogel particles, of anionic surfactants and of amphoteric surfactants, and also to a method of employment of the said composition. Hair has a tendency to lose some of its qualities under the action of factors such as natural regreasing, sweat, the removal of squamae, pollution, humidity and other factors. The visual appearance or the feel of the hair can thus be damaged. Regreasing, for example due to pollution, makes the hair lank, which then has a tendency to clump together. The hair can be difficult to style, in addition to having, for example, an unpleasant waxy feel or greasy sheen. In order to combat these inconveniences, it is possible to use detergent compositions, for example shampoos, in order to remove contaminants (sebum, sweat, pollution, and the like) or dandruff, and to loosen the hair. The hair is subsequently rinsed and then dried. The shampooing operations have to be repeated regularly, for example after a few days, indeed even after a few hours. However, shampoos, based on large amounts of surfactants, can be a nuisance, such as causing stinging on the scalp or in the eyes.

Shampooing compositions or compositions for washing the skin can also combine, with the surfactants, sebum absorbers in order to make it possible to extend in time the perception of cleanliness of the hair or skin. However, it has been found that the effectiveness of these products is still insufficient with respect to the expectations of consumers. This is because they do not make it possible to significantly reduce the frequency of washing of the hair in particular, which frequency can differ according to the country or even the region concerned and which can range from one to two shampooing operations per day to one or two shampooing operations per week.

To date, no hygienic cosmetic composition, in particular hair composition, makes it possible to significantly slow down regreasing, in particular of the hair.

The aim of the present invention is to provide cosmetic compositions which overcome these disadvantages.

The compositions according to the invention make it possible to retain a percep- tion of clean hair for a longer time than with a normal shampoo; by way of example, this perception of clean hair can be a week, for people who normally wash their hair 2 to 3 times weekly, and can be at least three days for people who normally wash their hair every day. Furthermore, the compositions according to the invention make it possible to obtain cleansing performances at least identical to those of a standard shampoo, in particular a very good detergency power. A subject-matter of the invention is thus a cosmetic composition comprising, in a cosmetically acceptable medium:

- hydrophobic silica aerogel particles,

- at least one anionic surfactant and

- at least one amphoteric or zwitterionic surfactant.

It has been found that the use of the compositions according to the invention makes it possible to significantly reduce regreasing of the hair and/or scalp and thus makes it possible to reduce the frequency of washing. In the present description, the expression "at least one" is equivalent to the expression "one or more" and can be substituted for it.

In the present description, the expression "between" or "of between" is equivalent to the expression "ranging from" and can be substituted for it. Hydrophobic silica aerogel particles

The composition according to the invention thus comprises hydrophobic silica aerogel particles.

Aerogels are ultralight porous materials which were first produced by Kristler in 1932.

They are generally synthesized by a sol-gel process in a liquid medium and then dried by extraction with a supercritical fluid. The supercritical fluid most commonly used is supercritical CO₂. This type of drying makes it possible to avoid the contraction of the pores and of the material. Other types of drying also make it possi- ble to obtain porous materials starting from gel, namely, for example, (i) drying by freeze drying, which consists in solidifying the gel at low temperature and in then subliming the solvent, and (ii) drying by evaporation. The materials thus obtained are referred to respectively as cryogels and xerogels. 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 term "hydrophobic silica" is understood to mean any silica whose surface is treated with silylating agents, for example halogenated silanes, such as alkylchlo- rosilanes; siloxanes, in particular dimethylsiloxanes, such as hexamethyldisilox- ane; or silazanes, so as to functionalize the OH groups with silyl groups Si-Rn, for example trimethylsilyl groups.

Preferably, the hydrophobic silica aerogel particles capable of being used in the present invention advantageously 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.

Preferably, the hydrophobic silica aerogel particles capable of being used in the present invention advantageously exhibit 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.

Preferably, the hydrophobic silica aerogel particles capable of being used in the present invention advantageously exhibit a size, expressed as mean diameter (D[0.5]), of less than 1500 μιτι and preferably 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. Preferably, the hydrophobic silica aerogel particles capable of being used in the present invention 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.

Preferably, the hydrophobic silica aerogel particles capable of being used in the present invention advantageously 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. According to a preferred embodiment, the hydrophobic silica aerogel particles according to the 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, a size, expressed as mean diameter (D[0.5]), ranging from 1 to 30 μιτι 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.

According to another preferred embodiment, the hydrophobic silica aerogel particles 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 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, which corresponds to international standard ISO 5794/1 (appendix D). The BET specific surface corresponds to the total specific surface of the particles under consideration.

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 ob- tain a homogeneous paste. It is measured according to the "wet point" method or the method for determining the oil uptake of a powder according to the principle 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 meas- uring the wet point, described below:

An amount w = 2 g of powder is placed on a glass plate and then the oil (isononyl isononanoate) is 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 con- glomerates 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 over the glass plate without cracks or the formation of lumps. The volume Vs (expressed in ml) of oil used is then noted.

The oil uptake (oil absorption capacity) corresponds to the ratio Vs/w.

The sizes of the aerogel particles according to the invention can be measured by static light scattering using a commercial particle sizer 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.

In the context of the present invention, the packed density can be assessed according to the following protocol, known as the packed density protocol: 40 g of powder are poured into a graduated measuring cylinder and then the measuring cylinder is placed on a 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%) and then the final volume Vf of packed powder is measured directly on the measuring cylinder. The packed density is determined by the ratio weight (w)A/f, in this case 40/Vf (Vf being expressed in cm³ and w in g).

The specific surface per unit of volume is given by the relationship: Sv = Sw^*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.

The hydrophobic silica aerogel particles used according to the present invention are preferably silylated silica (INCI name: silica silylate) aerogel particles.

The preparation of hydrophobic silica aerogel particles surface-modified by silyla- tion is further described in document US 7 470 725.

Use will in particular be made of aerogel particles of hydrophobic silica surface- modified by trimethylsilyl groups.

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 a mean 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, Enova Aerogel MT 1 100 and Enova Aerogel MT 1200.

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 a mean size ranging from 5 to 15 microns and a specific surface per unit of weight ranging from 600 to 800 m²/g.

It is, of course, possible to use a mixture of hydrophobic silica aerogel particles. The compositions according to the invention can comprise hydrophobic silica aerogel particles in an amount of between 0.01 % and 20% by weight, preferably between 0.05% and 10% by weight and preferentially between 0.1 % and 5% by weight, with respect to the total weight of the composition. Anionic surfactants

The composition according to the invention also comprises at least one anionic surfactant. It is, of course, possible to use a mixture of anionic surfactants.

The term "anionic surfactant" is understood to mean a surfactant comprising, as ionic or ionizable groups, only anionic groups. These anionic groups are preferably chosen from the following groups: CO₂H, CO₂ ^", SO₃H, SO₃ ^", OSO₃H, OSO₃ ^", -H₂PO₃, -HPO₃ ^", -PO₃ ^2", -H2PO2, =HPO₂, -HPO₂ ^", =PO₂ ^", =POH and =PO\

Mention may be made, among the anionic surfactants capable of being used in the composition according to the invention, of alkyl sulfates, alkyl ether sulfates, al- kylamido ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates, alkyl- sulfonates, alkylamidesulfonates, alkylarylsulfonates, a-olefinsulfonates, paraffin- sulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylamide sulfosuc- cinates, alkyl sulfoacetates, acyl sarcosinates, acyl glutamates, alykyl ether car- boxylates, alkyl sulfosuccinamates, acyl isethionates and N-acyl taurates; monoal- kyl esters of polyglycoside-polycarboxylic acids, acyl lactylates, salts of D- galactosideuronic acids, salts of alkyl ether carboxylic acids, salts of alkylaryl ether carboxylic acids, salts of alkylamido ether carboxylic acids; and the corresponding non-salified forms of all these compounds; the alkyl and acyl groups of all these compounds comprising from 6 to 24 carbon atoms and the aryl group denoting a phenyl group.

These compounds can be oxyethylenated and then preferably comprise from 1 to 50 ethylene oxide units and better still from 1 to 10 ethylene oxide units. The salts of C6-C₂₄ alkyl monoesters of polyglycoside-polycarboxylic acids can be chosen from C6-C₂₄ alkyl polyglycoside-citrates, C6-C₂₄ alkyl polyglycoside- tartrates and C6-C₂₄ alkyl polyglycoside-sulfosuccinates.

The acyl lactylates preferably have an acyl group comprising from 8 to 20 carbon atoms.

When the anionic surfactant is in the salt form, it can be chosen from the alkali metal salts, such as the sodium salt or potassium salt, the ammonium salt, the amine salts and in particular the aminoalcohol salts, or the alkaline earth metal salts, such as the magnesium salt.

Mention may be made, as examples of aminoalcohol salts, of monoethanolamine, diethanolamine and triethanolamine salts, monoisopropanolamine, diisopropa- nolamine or triisopropanolamine salts, 2-amino-2-methyl-1 -propanol salts, 2- amino-2-methyl-1 ,3-propanediol salts and tris(hydroxymethyl)aminomethane salts. Use is preferably made of alkali metal or alkaline earth metal salts and in particular of sodium or magnesium salts.

The preferred anionic surfactants are chosen from (C6-24)alkyl sulfates, (C6-24)alkyl ether sulfates, acyl glutamates and (C6-C2₄)alkyl ether carboxylates, in particular in the form of alkali metal, ammonium, aminoalcohol or alkaline earth metal salts, or a mixture of these compounds.

In particular, use is preferably made of (Ci2-2o)alkyl sulfates, (Ci2-2o)alkyl ether sul- fates comprising from 2 to 20 ethylene oxide units, acyl glutamates or (C12- C2o)alkyl ether carboxylates, in particular in the form of alkali metal, ammonium, aminoalcohol and alkaline earth metal salts, or a mixture of these compounds.

The composition according to the invention preferably comprises the anionic sur- factant or surfactants in an amount of between 0.1 % and 50% by weight, in particular between 4% and 30% by weight, indeed even between 5% and 20% by weight, with respect to the total weight of the composition.

Amphoteric or zwitterionic surfactants

The composition according to the invention also comprises at least one amphoteric or zwitterionic surfactant. It is, of course, possible to use a mixture of amphoteric or zwitterionic surfactants.

The amphoteric or zwitterionic surfactants capable of being used in the present invention can in particular be derivatives of optionally quaternized secondary or tertiary aliphatic amines comprising at least one anionic group, such as, for example, a carboxylate, sulfonate, sulfate, phosphate or phosphonate group, and in which the aliphatic group or at least one of the aliphatic groups is a linear or branched chain comprising from 8 to 22 carbon atoms.

Mention may in particular be made of (Cs-C2o)alkyl betaines, sulfobetaines, (Cs- C2o)alkylamido(Ci-C6)alkyl betaines, such as cocoamidopropyl betaine, or (Cs- C2o)alkylamido(Ci-C6)alkyl sulfobetaines. Mention may also be made, among the derivatives of optionally quaternized secondary or tertiary aliphatic amines capable of being employed, of the products with respective structures (A2) and (A3) below:

Ra-CONHCH2CH2-N+(Rb)(Rc)(CH2COO-) (A2)

in which:

R_a represents a C10-C30 alkyl or alkenyl group derived from an acid R_a-COOH preferably present in hydrolyzed coconut oil, or a heptyl, nonyl or undecyl group, R_b represents a β-hydroxyethyl group, and

R_c represents a carboxymethyl group;

Ra'-CONHCH2CH2-N(B)(B') (A3)

in which:

B represents -CH2CH2OX',

X' represents the group -CH2-COOH, CH2-COOZ', -CH2CH2-COOH or -CH2CH2-COOZ', or a hydrogen atom,

B' represents -(CH2)z-Y\ with z = 1 or 2,

Y' represents -COOH, -COOZ', the group -CH₂-CHOH-SO₃H or -CH₂-CHOH-

Z' represents an ion resulting from an alkali or alkaline earth metal, such as sodium, potassium or magnesium; an ammonium ion; or an ion resulting from an organic amine and in particular from an aminoalcohol, such as monoethanolamine, diethanolamine and triethanolamine, monoisopropanolamine, diisopropanolamine or triisopropanolamine, 2-amino-2-methyl-1 -propanol, 2-amino-2-methyl-1 ,3- propanediol and tris(hydroxymethyl)aminomethane,

R_a' represents a C10-C30 alkyl or alkenyl group of an acid R_a-COOH preferably present in hydrolyzed linseed oil or coconut oil, an alkyl group, in particular a C17 alkyl group, and its iso form, or an unsaturated C17 group.

The compounds corresponding to the formula (A3) are preferred. These compounds are also classified in the CTFA dictionary, 5th edition, 1993, under the names disodium cocoamphodiacetate, disodium lauroamphodiacetate, disodium caprylamphodiacetate, disodium caprylamphodiacetate, disodium cocoam- phodipropionate, disodium lauroamphodipropionate, disodium caprylam- phodipropionate, disodium caprylamphodipropionate, lauroamphodipropionic acid and cocoamphodipropionic acid.

Mention may be made, by way of example, of the cocoamphodiacetate sold by Rhodia under the trade name Miranol^® C2M Concentrate.

Use may also be made of the compounds of formula (A4):

R_a"-NH-CH(Y")-(CH2)n-C(O)-NH-(CH₂)n'-N(Rd)(Re) (A4)

in which: - Ra- represents a C 10-C30 alkyl or alkenyl group of an acid R_a"-C(O)OH preferably present in hydrolyzed linseed oil or coconut oil;

- Y" represents the group -C(O)OH, -C(O)OZ", -CH₂-CH(OH)-SO₃H or the group -CH₂-CH(OH)-SO3-Z", with Z" representing a cationic counterion resulting from an alkali metal or alkaline earth metal, such as sodium, an ammonium ion or an ion resulting from an organic amine;

- R_d and R_e represent, independently of one another, a Ci-C₄ alkyl or hydroxyalkyl radical; and

- n and n' denote, independently of one another, an integer ranging from 1 to 3.

Mention may in particular be made of the compound classified in the CTFA dictionary under the name sodium diethylaminopropyl cocoaspartamide and sold by Chimex under the name Chimexane HB. Preferably, the amphoteric or zwitterionic surfactants are chosen from (Cs- C2o)alkyl betaines, (C8-C2o)alkylamido(Ci-C6)alkyl betaines and (Cs- C2o)alkylamphodiacetates, and also the sodium salt of diethylaminopropyl laurylaminosuccinamate, and their mixtures.

Preferably, the amphoteric or zwitterionic surfactants are chosen, alone or as a mixture, from cocoylamidopropyl betaine, cocoyl betaine and cocoamphodiace- tate.

The composition according to the invention comprises the amphoteric or zwitterionic surfactant or surfactants in an amount preferably of between 0.1 % and 30% by weight, in particular between 1 % and 20% by weight, with respect to the total weight of the composition.

In a preferred embodiment, the anionic surfactant or surfactants are chosen from (C6-24)alkyl sulfates, (C6-24)alkyl ether sulfates comprising from 2 to 50 ethylene oxide units, acyl glutamates and (C6-C2₄)alkyl ether carboxylates, in particular in the form of alkali metal, ammonium, aminoalcohol or alkaline earth metal salts; and the amphoteric or zwitterionic surfactant or surfactants are chosen from (Cs- C2o)alkyl betaines, (C8-C2o)alkylamido(Ci-C6)alkyl betaines and (Cs- C2o)alkylamphodiacetates.

In a very particularly preferred embodiment, the anionic surfactant or surfactants are chosen from (Ci 2-2o)alkyl sulfates, (Ci 2-2o)alkyl ether sulfates comprising from 2 to 20 ethylene oxide units, acyl glutamates and (Ci2-C2o)alkyl ether carboxylates, in particular in the form of alkali metal, ammonium, aminoalcohol and alkaline earth metal salts; and the amphoteric or zwitterionic surfactant or surfactants are chosen from cocoylamidopropyl betaine, cocoyl betaine and cocoamphodiacetate.

In each of the embodiments described above, the concentration of anionic surfac- tant(s) (ii) and of amphoteric or zwitterionic surfactant(s) (iii) can be as described above.

Advantageously, the composition according to the invention can comprise a ratio by weight of the amount of anionic surfactant(s) to the amount of amphoteric or zwitterionic surfactant(s) of between 1 and 100 and better still of between 3 and 20.

Other ingredients

The cosmetic composition according to the invention generally comprises a cosmetically acceptable medium, that is to say a medium compatible with keratinous substances, such as the skin of the face or of the body, the lips, the hair, the eyelashes, the eyebrows and the nails. The compositions according to the invention can be provided in any formulation form conventionally used and in particular in the form of an aqueous, alcoholic or aqueous/alcoholic solution or suspension or oily solution or suspension; of a solution or a dispersion of the lotion or serum type; of an emulsion, in particular having a liquid or semi-liquid consistency, of the O/W, W/O or multiple type; of a suspen- sion or emulsion having a soft consistency of (O/W) or (W/O) cream type; of an aqueous or anhydrous gel, or of any other cosmetic form.

These compositions can be packaged in pump-action sprays or in aerosol containers, in order to provide for application of the composition in the vaporized (lacquer) form or in the form of a mousse. Such packaging forms are indicated, for example, when it is desired to obtain a spray or a mousse, for the treatment of the hair. In these cases, the composition preferably comprises at least one propellant.

The composition according to the invention can be aqueous or anhydrous. It is preferably aqueous and then comprises water at a concentration preferably rang- ing from 5% to 98% by weight, in particular from 20% to 95% by weight and better still from 50% to 90% by weight, with respect to the total weight of the composition.

The composition can also comprise one or more organic solvents which are liquid at 25°C and 1 atm, in particular water-soluble solvents, such as C1-C7 alcohols; mention may in particular be made of aliphatic or aromatic Ci-C₇ monoalcohols, C3-C₇ polyols or C3-C₇ polyol ethers, which can thus be employed alone or as a mixture with water. Advantageously, the organic solvent can be chosen from etha- nol, isopropanol, benzyl alcohol and their mixtures.

The composition according to the invention can additionally comprise at least one normal cosmetic ingredient, other than the compounds of the invention, chosen in particular from propellants; vegetable, mineral, animal or synthetic oils; solid fatty substances, in particular waxes, Cs-C₄o esters, Cs-C₄o acids; Cs-C₄o alcohols; non- ionic surfactants, cationic surfactants; sunscreens; moisturizing agents; antidan- druff agents; antioxidants; chelating agents; reducing agents; oxidation bases, couplers, oxidizing agents, direct dyes; hair-straightening agents, such as thiols and alkaline hydroxides; pearlescent agents and opacifiers; plasticizing or coalescence agents; hydroxy acids; pigments; fillers; silicones and in particular polydi- methylsiloxanes (PDMSs); polymeric or non-polymeric thickeners; gelling agents; emulsifiers; conditioning or styling polymers; fragrances; basifying or acidifying agents; silanes; crosslinking agents, such as polyphenols, aldehydes or DHA. The composition can, of course, comprise several cosmetic ingredients appearing in the above list.

Depending on their nature and the purpose of the composition, the normal cosmetic ingredients can be present in normal amounts which can be easily determined by a person skilled in the art and which can be, generally, for each ingredient, between 0.01 % and 80% by weight. The oils can preferably be present in a proportion of 0.01 % to 80% by weight, in particular 0.02% to 40% by weight, indeed even 0.5% to 20% by weight, with respect to the total weight of the composition. They can be carbon-based oils. Mention may in particular be made of vegetable, animal or mineral oils, which may or may not be hydrogenated; saturated or unsaturated, linear or branched, cyclic or aliphatic, synthetic hydrocarbon oils, such as, for example, poly-alpha-olefins, in particular polydecenes and polyisobutenes; liquid fatty alcohols, such as isostearyl alcohol, octyldodecanol, 2-butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol, oleyl alcohol or linoleyl alcohol; or liquid esters, such as isopropyl myristate or iso- propyl palmitate. Mention may also be made of silicone oils, which may or may not be volatile, which may or may not be organomodified and which may or may not be water-soluble; fluorinated or perfluorinated oils; and their mixtures.

The composition can also comprise one or more solid fatty substances and in particular one or more fatty alcohols, fatty esters and/or fatty acids, other than the above oils, having from 8 to 40 carbon atoms; these solid fatty substances can preferably be present in a proportion of 0.01 % to 30% by weight, in particular 0.1 % to 20% by weight, with respect to the total weight of the composition. Mention may in particular be made of fatty alcohols comprising linear C12-C32 chains, in particular C12-C26 chains, and especially of cetyl alcohol, stearyl alcohol, cetearyl alcohol or behenyl alcohol. Mention may also be made of fatty acids comprising linear or branched Ci6-C₄o chains and in particular of 18-methyleicosanoic acid, coconut oil or hydrogenated coconut oil acids; stearic acid, lauric acid, palmitic acid and oleic acid, behenic acid, and their mixtures. Preferably, the fatty acids are non-salified. Mention may also be made of fatty esters comprising linear chains, comprising in total between 8 and 40 carbon atoms, such as myristyl, cetyl or stearyl myristates, palmitates and stearates, alone or as a mixture.

A person skilled in the art will take care to choose the ingredients participating in the composition and their amounts so that they are not harmful to the properties of the compositions of the present invention. The pH of the composition, if it is aqueous, can be acidic, neutral or alkaline. Preferably, the composition exhibits a pH of between 2 and 1 1 , in particular 3 to 9, indeed even 3 to 7.

The cosmetic composition according to the invention can be provided in the form of a product for caring for, cleansing and/or making up the skin of the body or of the face, the lips, the eyebrows, the eyelashes, the nails and the hair, of an anti- sun or self-tanning product, of a body hygiene product or of a haircare product, in particular for caring for, cleansing, styling, shaping or dyeing the hair.

The composition especially finds a particularly advantageous application in the hair field, in particular for the retention of the hairstyle or the shaping of the hair, or the care, cosmetic treatment or cleansing of the hair. The hair compositions are preferably shampoos, conditioners, styling or care gels, care lotions or creams, masks, serums, hairsetting lotions, blow-drying lotions, fixing and styling compositions, such as lacquers or sprays, hair restructuring lotions, lotions or gels for combatting hair loss, antiparasitic shampoos, antidandruff lotions or shampoos, or antiseborrhoeic treating shampoos. The lotions can be packaged in various forms, in particular in vaporizers, pump-action sprays or aerosol containers, in order to provide for application of the composition in vaporized form or in the form of a mousse.

The composition according to the invention finds a particularly advantageous ap- plication for caring for, treating and/or cleansing the hair and/or scalp, for example in a shampooing operation, in a conditioning operation, in the after-treatment of a shampooing operation and/or of a conditioning operation; or else between two shampooing operations.

It is thus possible, for example, to apply the composition according to the invention on the scalp and/or hair, for example but not necessarily directly after a shampooing operation, on wet hair or on dry hair, with or without a leave-in time, with or without heat, the said application being followed or not followed by a rinsing operation and by a drying operation, either at ambient temperature or with a hair dryer or also with a smoothing iron (250°C), for example.

It is also possible to apply the composition according to the invention on the scalp and/or hair between two shampooing operations, on wet hair or on dry hair.

The cosmetic composition may or may not be rinsed off after having been applied to the keratinous substances (hair and/or scalp).

Another subject-matter of the invention is a method for the cosmetic treatment, in particular for making up, caring for, cleansing, dyeing or shaping, of keratinous substances, in particular of the skin of the body or of the face, the lips, the nails, the hair and/or the eyelashes, comprising the application, to the said substances, of a cosmetic composition according to the invention.

It is in particular a hair treatment method for the care, cosmetic treatment and/or cleansing of the hair and/or scalp, which makes it possible in particular to slow down, indeed even to prevent, the regreasing of the hair and/or scalp and thus to space out the shampooing operations.

The invention is illustrated in more detail in the following examples.

Examples 1 to 3

The following shampooing compositions are prepared (% by weight of the com- mercial product):

Composition 1

Silica Silylate (INCI name) 0.5%

Sodium lauryl ether sulfate comprising 2.2 mol

of EO, at 70% in aqueous solution (Texapon

AOS 225 UP from Cognis) 22%

Cocoyl betaine, at 30% in aqueous solution

(Dehyton AB 30 from Cognis) 8%

pH agent q.s. for pH 3.5

Water q.s. for 100%

Composition 2

Silica Silylate (INCI name) 0.5%

Sodium lauryl ether sulfate comprising 2.2 mol

of EO, at 70% in aqueous solution (Texapon

AOS 225 UP from Cognis) 22%

Cocoamphodiacetate (Miranol C2M Cone. NP

from Rhodia) 8%

pH agent q.s. for pH 3.5

Water q.s. for 100%

Cocoyl betaine, at 30% in aqueous solution

(Dehyton AB 30 from Cognis) 17%

pH agent q.s. for pH 3.5

Water q.s. for 100%

The Silica Silylate employed is the product sold under the name Dow Corning VM- 2270 Aerogel Fine Particles by Dow Corning. Compositions 1 to 3 are provided in the form of a dispersion; they are easy to apply on the hair and scalp; they make it possible to reduce the regreasing of the hair and in addition contribute styling properties to the hair.

Claims

1 . Cosmetic composition comprising:

- hydrophobic silica aerogel particles,

- at least one anionic surfactant and

- at least one amphoteric or zwitterionic surfactant.

2. Composition according to Claim 1 , in which the hydrophobic silica aerogel parti- cles 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.

3. Composition according to either one of the preceding claims, in which the hydrophobic silica aerogel particles exhibit 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.

4. Composition according to any one of the preceding claims, in which the hydrophobic silica aerogel particles exhibit a size, expressed as mean diameter (D[0.5]), of less than 1500 μιτι and preferably 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.

5. Composition according to any one of the preceding claims, in which the hydrophobic silica aerogel particles 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.

6. Composition according to any one of the preceding claims, in which the hydrophobic silica aerogel particles 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.

7. Composition according to any one of the preceding claims, in which the hydrophobic silica aerogel particles are silylated silica aerogel particles and in particular hydrophobic silica aerogel particles surface-modified by trimethylsilyl groups.

8. Composition according to any one of the preceding claims, in which the hydrophobic silica aerogel particles are present in an amount of between 0.01 % and 20% by weight, preferably between 0.05% and 10% by weight and preferentially between 0.1 % and 5% by weight, with respect to the total weight of the composi- tion.

9. Composition according to any one of the preceding claims, in which the anionic surfactants are chosen from (C6-24)alkyl sulfates, (C6-24)alkyl ether sulfates, acyl glutamates and (C6-C2₄)alkyl ether carboxylates, in particular in the form of alkali metal, ammonium, aminoalcohol or alkaline earth metal salts, or a mixture of these compounds.

10. Composition according to any one of the preceding claims, in which the anionic surfactant or surfactants are present in an amount of between 0.1 % and 50% by weight, in particular between 4% and 30% by weight, indeed even between 5% and 20% by weight, with respect to the total weight of the composition.

1 1 . Composition according to any one of the preceding claims, in which the amphoteric or zwitterionic surfactants are chosen from (Cs-C2o)alkyl betaines, sulfobetaines, (C8-C2o)alkylamido(Ci-C6)alkyl betaines, (C8-C2o)alkylamido(Ci- C6>alkyl sulfobetaines and (C8-C2o)alkylamphodiacetates, and also the sodium salt of diethylaminopropyl laurylaminosuccinamate, and their mixtures.

12. Composition according to any one of the preceding claims, in which the amphoteric or zwitterionic surfactant or surfactants are present in an amount of between 0.1 % and 30% by weight, in particular between 1 % and 20% by weight, with respect to the total weight of the composition.

13. Composition according to any one of the preceding claims, in which the ratio by weight of the amount of anionic surfactant(s) to the amount of amphoteric or zwitterionic surfactant(s) is between 1 and 100 and better still between 3 and 20.

14. Composition according to any one of the preceding claims, comprising water at a concentration ranging from 5% to 98% by weight, in particular from 20% to 95% by weight and better still from 50% to 90% by weight, with respect to the total weight of the composition.

15. Composition according to any one of the preceding claims, which is provided in the form of a hair product, in particular for the care, cosmetic treatment or cleansing of the hair and/or scalp.

16. Method for the cosmetic treatment, in particular for making up, caring for, cleansing, dyeing or shaping, of keratinous substances, in particular of the skin of the body or of the face, the lips, the nails, the hair and/or the eyelashes, comprising the application, to the said substances, of a cosmetic composition according to one of Claims 1 to 15.

17. Method according to Claim 16 for hair treatment, for the care, cosmetic treatment and/or cleansing of the hair and/or scalp, which makes it possible in particular to slow down, indeed even to prevent, the regreasing of the hair and/or scalp.