Composition comprising a gelling agent and specific particles

Abstract

Composition comprising a gelling agent and specific particles The present invention relates to a composition comprising, in a physiologically acceptable medium: - at least one gelling agent chosen from homo- and copolymers comprising a 2-acrylamido-2-methyl-propanesulfonic acid monomer, clays, polysaccharides consisting solely of glucose, polysaccharides rich in fucose and mixtures thereof; and - at least one hollow silica particle comprising a shell containing silica and a hollow space inside the shell, said particle having a size of between 100 nm and 5 µm and having a refractive index of less than 1.3. The present invention also relates to a cosmetic process for caring for keratin materials, preferably the skin, comprising the application to said keratin materials of a composition according to the invention. Figure for abstract: none

Description

Title of the invention: Composition comprising a gelling agent and specific particles

[0001] The present invention relates to a composition comprising, in a physiologically acceptable medium:

[0002] - at least one gelling agent chosen from homo- and copolymers comprising a 2-acrylamido-2-methyl-propanesulfonic acid monomer, clays, polysaccharides consisting solely of glucose, fucose-rich polysaccharides and mixtures thereof; and

[0003] - at least one hollow silica particle comprising a shell containing silica and a hollow space inside the shell, said particle having a size (primary particle size) between 100 nm and 5 pm and having a refractive index of less than 1.3.

[0004] The present invention also relates to a cosmetic process for caring for keratin materials, preferably the skin, comprising the application to said keratin materials of a composition according to the invention.

[0005] Cosmetic compositions for skin care or makeup generally aim to unify the complexion. In particular, they aim to mask and / or blur imperfections. This blurred effect which camouflages the micro-reliefs of the skin is also called the soft-focus effect.

[0006] In cosmetics, the search for soft-focus properties to mask imperfections is a real challenge.

[0007] To add blurred effects and obtain a soft-focus effect, it is classically known to use particles having a size (primary particle size) greater than 5 pm, such as silica or cellulose spheres for example.

[0008] However, such particles can cause problems of comfort and sensoriality upon application. Indeed, these particles are generally added in a significant quantity, which causes these cosmetic inconveniences.

[0009] To overcome this discomfort, smaller particles can be used. However, the use of gelling agents conventionally used in cosmetics, such as xanthan gum, (meth)acrylic polymer (such as Pemulen) or cellulose derivative (such as hydroxyethylcellulose or cellulose gum), does not allow these particles to be dispersed correctly, which results in poor cosmetic and optical performance.

[0010] There is therefore a need for compositions exhibiting a soft-focus effect, containing an optimal dispersion of particles. Such a dispersion then allows a total expression of the optical properties of the particles and thus the blurring of imperfections such as wrinkles, fine lines and / or pores.

[0011] The present invention solves this problem.

[0012] Indeed, the Applicant has now discovered that the dispersion of particles of size (primary particle size) between 100 nm and 5 pm and having a specific refractive index, provides the cosmetic film with soft-focus effects. In addition, thanks to the addition of a particular gelling agent, no aggregation of the particles is observed: the dispersion is optimal.

[0013] The combination of the particles and the gelling agent according to the invention thus allows optimal dispersion of the particles, while improving their soft-focus effect capacity (including masking and coverage).

[0014] The present invention therefore relates to a composition comprising, in a physiologically acceptable medium:

[0015] - at least one gelling agent chosen from homo- and copolymers comprising a 2-acrylamido-2-methyl-propanesulfonic acid monomer, clays, polysaccharides consisting solely of glucose, fucose-rich polysaccharides and mixtures thereof; and

[0016] - at least one hollow silica particle comprising a shell containing silica and a hollow space inside the shell, said particle having a size (primary particle size) between 100 nm and 5 pm and having a refractive index of less than 1.3.

[0017] The composition is preferably in the form of an emulsion, more preferably direct (oil-in-water).

[0018] By “physiologically acceptable” is meant a medium compatible with keratin materials.

[0019] The present invention also relates to a cosmetic process for caring for keratin materials, preferably the skin, comprising the application to said keratin materials of a composition according to the invention. Gelling agent

[0020] The composition according to the invention comprises at least one gelling agent chosen from homo- and copolymers comprising a 2-acrylamido-2-methyl-propanesulfonic acid monomer, clays, polysaccharides consisting solely of glucose and polysaccharides rich in fucose.

[0021] The gelling agent ensures good dispersion of the particles and thus allows the expression of their optical properties, without cosmetic inconvenience.

[0022] The concentration of gelling agent (i.e. active material) generally ranges from 0.1 to 20% by weight relative to the total weight of the composition, and preferably from 0.5 to 15% by weight, preferably from 0.5 to 10% by weight and even more particularly from 0.5 to 5%. in weight.

[0023] Polymers comprising a 2-acrvlamido-2-methyl-propane acid monomer sulfonic

[0024] The gelling agent may be chosen from homo- and copolymers comprising a 2-acrylamido-2-methyl-propane sulfonic acid monomer.

[0025] Homopolymers of 2-acrylamido-2-methyl-propane sulfonic acid (AMPS®, Lubrizol monomer) or their salts may or may not be crosslinked.

[0026] Such a homopolymer may have a number average molecular weight ranging from 1000 to 20,000,000 g / mol, preferably ranging from 20,000 to 5,000,000 and more preferably still from 100,000 to 1,500,000 g / mol.

[0027] More particularly, 2-acrylamido-2-methylpropanesulfonic acid and its partially or totally neutralized forms are used.

[0028] When the polymers are crosslinked, the crosslinking agents can be chosen from olefinically polyunsaturated compounds commonly used for crosslinking polymers obtained by radical polymerization.Examples of crosslinking agents that may be mentioned are divinylbenzene, diallyl ether, dipropylene glycol diallyl ether, polyglycol diallyl ethers, triethylene glycol dipropylene ether, hydroquinone diallyl ether, ethylene glycol or tetraethylene glycol di(meth)acrylate, trimethylol propane triacrylate, methylene bis acrylamide, methylene bis methacrylamide, triallylamine, triallyl cyanurate, diallyl maleate, tetraallylethylenediamine, tetraallyloxyethane, trimethylol propane diallyl ether, allyl (meth)acrylate, allyl ethers of sugar alcohols, or other allyl or vinyl ethers of polyfunctional alcohols, as well as allyl esters of derivatives of phosphoric and / or vinylphosphonic acid, or mixtures of these compounds.

[0029] According to a preferred embodiment of the invention, the crosslinking agent is chosen from methylene-bis-acrylamide, allyl methacrylate or trimethylol propane triacrylate (TMPTA). The crosslinking rate generally ranges from 0.01 to 10 mol% and more particularly from 0.2 to 2 mol% relative to the polymer.

[0030] The homopolymer only comprises monomers with a sulfonic group and, if it is crosslinked, one or more crosslinking agents.

[0031] The preferred 2-acrylamido-2-methylpropanesulfonic acid homopolymers are generally characterized by the fact that they comprise, randomly distributed:

[0032] a) from 90 to 99.9% by weight of units of the following general formula:

[0033] [Chem.l] CH. ----CH^SCÇX* CHâ

[0034] in which X+ denotes a proton, an alkali metal cation, an alkaline earth cation or the ammonium ion, at most 10 mol% of the X+ cations being able to be H+ protons;

[0035] and crosslinking units originating from at least one monomer having at least two olefinic double bonds, the proportions by weight being defined relative to the total weight of the polymer.

[0036] The more particularly preferred homopolymers according to the invention comprise from 98 to 99.5% by weight of units of formula (I) above and from 0.2 to 2% by weight of crosslinking units.

[0037] As polymers of this type, mention may in particular be made of the crosslinked and neutralized homopolymer of 2-acrylamido 2-methylpropane sulfonic acid, marketed by the company Clariant under the trade name “Hostacerin AMPS®” (INCI name: Ammonium Polyacryldimethyltauramide).

[0038] The polymer may also be an amphiphilic homopolymer (or hydrophobic modified homopolymer) chosen from random amphiphilic polymers of 2-acrylamido-2-methylpropanesulfonic acid modified by reaction with a C6-C22 n-monoalkylamine or di-n-alkylamine, such as those described in document WO-A-00 / 31154, which are grafted homopolymers.

[0039] The gelling agent may also be chosen from copolymers of acrylamido-2-methyl propane sulfonic acid or its salts and one or more non-ionic monomers. They may be crosslinked or non-crosslinked.

[0040] When the polymers are crosslinked, the crosslinking agents may be chosen from olefinically polyunsaturated compounds commonly used for crosslinking polymers obtained by radical polymerization. Such agents are described above.

[0041] According to a preferred embodiment of the invention, the crosslinking agent is chosen from methylene-bis-acrylamide, allyl methacrylate or trimethylol propane triacrylate (TMPTA). The crosslinking rate generally ranges from 0.01 to 10 mol% and more particularly from 0.2 to 2 mol% relative to the polymer.

[0042] The copolymers according to the invention are obtained from AMPS® (Lubrizol monomer) and one or more hydrophilic or hydrophobic ethylenically unsaturated non-ionic monomers and, if they are crosslinked, one or more crosslinking agents such as those defined above.

[0043] The 2-acrylamido-2-methylpropanesulfonic acid monomer of the copolymer contained in the composition according to the invention is in free form or is partially or totally neutralized by a mineral base (soda, potash, ammonia) or an organic base such as mono-, di-, or tri-ethanolamine, an amino-nomethylpropanediol, N-methyl-glucamine, basic amino acids such as arginine and lysine as well as the mixture of these compounds.

[0044] Preferably, the 2-acrylamido-2-methylpropane sulfonic acid monomer is partially or completely salified in the form of an ammonium or sodium salt.

[0045] Preferably, the 2-acrylamido-2-methylpropane sulfonic acid monomer is fully salified, preferably in the form of ammonium or sodium salt.

[0046] AMPS® copolymers (Lubrizol monomer) contain one or more nonionic monomers selected from water-soluble ethylenically unsaturated monomers, hydrophobic monomers, or mixtures thereof.

[0047] Among the non-ionic water-soluble monomers, we can cite for example:

[0048] - (meth)acrylamide,

[0049] - N-vinylacetamide and N-methyl N-vinylacetamide,

[0050] - N-vinylformamide and N-methyl N-vinylformamide,

[0051] - maleic anhydride,

[0052] - vinylamine,

[0053] - N-vinyllactams comprising a cyclic alkyl group having from 4 to 9 atoms of carbon, such as N-vinylpyrrolidone, N-butyrolactam and N-vinylcaprolactam,

[0054] - vinyl alcohol of formula CH2=CHOH,

[0055] - the water-soluble vinyl monomers of the following formula (2):

[0056] [Chem.2] <- * L. V"" (2)

[0057] in which:

[0058] - Rb is chosen from H, -CH3, -C2H5 or -C3H7

[0059] - X2 is chosen from alkyl oxides of type -ORi6 where Ri6 is a hy radical carbonaceous, linear or branched, saturated or unsaturated, having from 1 to 6 carbons, even- partially substituted by a halogen atom (iodine, bromine, chlorine, fluorine); a hydroxy group (-OH); ether.

[0060] Examples include glycidyl (meth)acrylate, hydroxyethyl (meth)acrylate, and ethylene glycol, diethylene glycol, or polyalkylene glycol (meth)acrylates.

[0061] Preferably the water-soluble monomer is chosen from acrylamide, vinylpyrrolidone, hydroxyalkyl(meth)acrylates, more particularly vinylpyrrolidone.

[0062] As copolymers of AMPS® (Lubrizol monomer) in accordance with the invention with hydrophilic monomers, we can cite for example:

[0063] - copolymers of acrylamido-2-methyl propane sulfonic acid and vinylpyr rolidone such as in particular the commercial product ARISTOFLEX AVC sold by CLARIANT,

[0064] - crosslinked acrylamide / acrylamido-2-methyl propane sulfonate copolymers of sodium, such as that used in the commercial product SEPIGEL 305® (INCI name: Polyacrylamide / Ci3-Ci4 Isoparaffin / Laureth-7) or that used in the commercial product sold under the name SIMULGEL 600® (INCI name: Acrylamide / Sodium Acryloyldimethyltaurate / Isohexadecane / Polysorbate-80) by the company SEPPIC;

[0065] - copolymers of AMPS® (Lubrizol monomer) and hydroxyethyl acrylate, such as for example the AMPS® sodium / hydroxyethyl acrylate copolymer such as that used in the commercial product sold under the name SIMULGEL NS® by the company SEPPIC (INCI name: Hydroxyethyl acrylate / Sodium Acryloyldimethyltaurate copolymer (and) Squalane (and) Polysorbate 60);

[0066] - hydrophobically modified AMPS® copolymers such as the copolymer known as INCI: AMMONIUM ACRYLOYLDIMETHYLTAURATE / STEARETH-25 METHACRYLATE CROSSPOLYMER sold under the trade name ARISTOFLEX HMS by the company CLARIANT. Clays

[0067] The composition may comprise at least one clay. Clays are products already well known in themselves, which are described for example in the work "Minéralogie des argiles, S. Caillère, S. Hénin, M. Rautureau, 2nd edition 1982, Masson".

[0068] Clays are silicates containing a cation which can be chosen from calcium, magnesium, aluminum, sodium, potassium, lithium cations and their mixtures.

[0069] Examples of such products include clays from the smectite family such as montmorillonites, hectorites, bentonites, beidellites, saponites, as well as from the vermiculite, stevensite or chlorite family.

[0070] These clays can be of natural or synthetic origin. Preferably, we use clays which are cosmetically compatible and acceptable with keratin materials such as skin.

[0071] The clay is preferably chosen from hydrophilic clays. These clays are clays modified by chemical compounds making the clay capable of swelling in aqueous media.

[0072] The clay may be chosen from montmorillonite, bentonite, hectorite, attapulgite, sepiolite and mixtures thereof.

[0073] The clay is preferably a bentonite or a hectorite.

[0074] These clays can be modified with a chemical compound chosen from quaternary amines, tertiary amines, amine acetates, imidazolines, amine soaps, fatty sulfates, alkyl aryl sulfonates, amine oxides, and mixtures thereof.

[0075] Polysaccharides consisting solely of glucose and polysaccharides rich in fucose

[0076] The composition may comprise at least one polysaccharide consisting solely of glucose and / or at least one polysaccharide rich in fucose.

[0077] Polysaccharides consisting solely of glucose

[0078] The polysaccharides consisting solely of glucose are preferably chosen from sclerotium gum and modified or unmodified starches.

[0079] Sclerotium gum (or scleroglucan) is a naturally occurring hydrophilic polymer. It is a polymerized glucose, which can be obtained from a variety of Sclerotium fungi, in particular Sclerotium rolfsii. Sclerotium gum (also called scleroglucan gum) is a polysaccharide consisting solely of glucose units. Sclerotium gum is used as a thickening and gelling agent. A particularly suitable sclerotium gum is available from Alban Mueller International under the trade name Amigel or Amigel Granule.

[0080] Starches are polysaccharides of D-glucose. They can be modified or unmodified.

[0081] Preferably, unmodified starches will be used.

[0082] Among the unmodified starches, mention may be made of unmodified corn starches (INCI name: ZEA MAYS STARCH) such as the products sold under the trade names Farmal CS® in particular the commercial product Farmal CS 3650® by the company Corn Products International. Mention may also be made of unmodified rice starches (INCI name: ORYZA SATIVA (RICE) STARCH) such as the commercial product REMY DR I® sold by the company BENEO-REMY.

[0083] Mention may also be made of distarch phosphates or compounds rich in distarch phosphate, in particular hydroxypropyl ethers of distarch phosphate. distarch with the INCI name Hydroxypropyl Starch Phosphate such as products sold under the trade names Farinex VA70 C or FARMAL MS 689® from the company AVEBE Stadex; or products sold under the trade names Structure BTC®, Structure HVS®, Structure XL® or STRUCTURE ZEA® from NATIONAL STARCH (corn distarch phosphate).

[0084] Polysaccharides rich in fucose

[0085] The fucose-rich polysaccharides are preferably polyholosides comprising more than 10 oses.

[0086] The oses can be chosen from all conceivable oses, of natural or synthetic origin, and in particular such as:

[0087] aldoses such as pentoses such as ribose, arabinose, xylose or apiose, or hexoses such as glucose, fucose, mannose or galactose,

[0088] ketoses such as fructose,

[0089] deoxyoses, such as rhamnose, digitoxose, cymarose or oleandrose, or

[0090] ose derivatives such as uronic acids like mannuronic acids, glu- curonic, galacturonic or glucuronic, or even itols such as mannitol or sorbitol.

[0091] Among these oses, trehalose and / or hexoses will be used more preferably, and more particularly glucose, mannose, rhamnose and / or fucose.

[0092] Mention may also be made of their derivatives, in particular alkylated ones, such as methylated derivatives like methylglucose, as well as compounds containing one or more sugars, and their mixtures.

[0093] Preferably, the fucose-rich polysaccharide is a polymer containing fucose, galactose and galacturonic acid.

[0094] As a polysaccharide rich in fucose, mention may be made of natural compounds such as honey, and polymers such as, for example, the product marketed under the name “Fucogel 1000” by the company Solabia (CTFA name Biosaccharide gum-1), a polymer containing fucose, galactose and galacturonic acid. Particles

[0095] The composition according to the invention comprises at least one hollow silica particle comprising a shell containing silica and a hollow space inside the shell, said particle having a primary particle size of between 100 nm and 5 pm and having a refractive index of less than 1.3.

[0096] The particle according to the invention is a hollow silica particle comprising a shell containing silica and a hollow space inside the shell.

[0097] Thus, the hollow silica particles of the present invention comprise a shell containing silica, and have a space (void) inside the shell.

[0098] The fact that the hollow silica particles have a space inside the layer shell can be confirmed by transmission electron microscopy (TEM) or scanning electron microscopy (SEM) observation. In the case of SEM observation, the particle can be confirmed to be hollow by observing a partially broken particle. A particularly spherical particle with a space inside said particle, which can be confirmed by TEM or SEM observation, is defined as a "primary particle". In hollow silica particles, the primary particles are partially bonded to each other during manufacturing and drying, so the hollow silica obtained during manufacturing is often an aggregate of secondary particles in which the primary particles are aggregated.

[0099] Preferably, the primary particles have a size (diameter) of between 100 nm and 3 pm, preferably of between 150 nm and 1 pm, preferably of between 200 nm and 900 nm, preferably of between 300 nm and 800 nm.

[0100] The primary particle size is measured by scanning electron microscopy (SEM). Specifically, the primary particle size of 100 particles is measured from an SEM image, and the primary particle size distribution obtained by aggregating them is evaluated as the overall primary particle size distribution.

[0101] The size of the secondary particles (agglomeration diameter (D50)) of hollow silica is preferably 0.1 to 50 μm.

[0102] The agglomeration diameter (D50) of the secondary particles is preferably 0.2 pm or more, preferably 0.3 pm or more, particularly preferably 0.4 pm or more, and preferably 0.5 pm or more. Furthermore, from the viewpoint of dispersibility when mixed with a water or oil type solvent, the agglomeration diameter (D50) of the secondary particles is preferably 35 pm or less, more preferably 30 pm or less, even more preferably 25 pm or less, preferably 15 pm or less. The method for measuring the agglomeration diameter (D50) of the secondary particles is a method in which the median value of the particle distribution (diameter) is measured by a diffraction measuring apparatus, for example MT3300 of Microtrac Bell. The apparatus makes two measurements and the average value is determined.

[0103] Preferably, the thickness of the envelope is between 0.01 and 0.3 for a primary particle diameter of 1. The thickness of the envelope is measured by observation in transmission electron microscopy (TEM).

[0104] In the composition according to the invention, said particle is hollow and is advantageously in the form of an envelope, in particular spherical, around a single hollow space. In particular, the envelope of the particle is impermeable to the rest of the composition, so that the hollow space of the particle remains empty, even though the particle is located within the composition according to the invention. By the expression "the envelope of the particle is impermeable to the rest of the composition", we mean that the envelope is impermeable to the other ingredients of the composition, in particular impermeable to water, oil and solvents possibly present in the composition.

[0105] The refractive index nparticulates is calculated from the composition of the materials in volume proportion, defined by the following equation with ni the index of the material i and the volume fraction of the material i in the particle:

[0106] [Math.l]

[0107] The particle has a refractive index of less than 1.3. Preferably, the particle has a refractive index of between 1 and 1.3, preferably between 1.1 and 1.3.

[0108] The particles may have a spherical or non-spherical shape. When the particles have a non-spherical shape, they may in particular be in the form of platelets.

[0109] Preferably, the particles are white in color.

[0110] As particles that can be used according to the invention, mention may be made of the particles marketed under the name Sunballoon HS-040 by AGC SLTECH. These particles are hollow spherical silica particles. They have a refractive index of 1.13 and a primary particle size of between 400 nm and 800 nm.

[0111] Mention may also be made of the particles marketed under the name Sunballoon HS-070 by AGC SLTECH. These particles are hollow spherical silica particles. They have a refractive index of between 1.10 and 1.25 and a primary particle size of between 400 nm and 800 nm.

[0112] Mention may also be made of the particles marketed under the name Sunballoon HS-200 by AGC SLTECH. These particles are hollow spherical silica particles. They have a refractive index of between 1.10 and 1.25 and a primary particle size of between 400 nm and 800 nm.

[0113] Preferably, the composition according to the invention comprises from 0.1 to 20% by weight of particles relative to the total weight of the composition, and preferably from 0.2 to 10% by weight, preferably from 0.3 to 7% by weight and even more particularly from 0.4 to 3% by weight. Aqueous phase

[0114] The composition according to the invention may comprise an aqueous phase.

[0115] The aqueous phase comprises water and optionally an organic solvent soluble in water, at 25°C, chosen for example from polyols; alkanols, linear or branched, C2-C4, such as ethanol and isopropanol, propanol, butanol; and mixtures thereof.

[0116] By polyol is meant a hydrocarbon chain comprising at least 2 carbon atoms, preferably from 2 to 50 carbon atoms, preferably from 4 to 20 carbon atoms, preferably having from 2 to 10 carbon atoms, and preferentially having from 2 to 6 carbon atoms, and carrying at least two hydroxyl groups. The polyols used in the present invention may have a weight-average molecular mass of less than or equal to 1000, preferably between 90 and 500. The polyol may be a natural or synthetic polyol. The polyol may have a linear, branched or cyclic molecular structure.

[0117] The polyol may be selected from glycerin and derivatives thereof, and glycols and derivatives thereof. The polyol may be selected from the group consisting of glycerin, diglycerin, polyglycerin, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, pentylene glycol, hexylene glycol, 1,3-propanediol, 1,5-pentanediol, octane 1,2-diol, polyethylene glycols, especially having from 5 to 50 ethylene oxide groups, and sugars such as sorbitol, and mixtures thereof. Preferably, the polyol is glycerin.

[0118] Said water-soluble organic solvent(s) may be present in a content ranging from 1% to 30% by weight, relative to the total weight of the composition, preferably ranging from 2% to 25% by weight, and preferentially ranging from 5% to 20% by weight.

[0119] The composition generally comprises from 10% to 99% by weight of water relative to the total weight of the composition, preferably from 30% to 98% by weight, preferably from 35% to 90% by weight.

[0120] Preferably, the composition according to the invention further comprises an oily phase.

[0121] Preferably, the composition according to the invention is an oil-in-water emulsion. Oily phase

[0122] The composition according to the invention preferably also comprises at least one oily phase. When the composition used according to the invention comprises an oily phase, the latter preferably contains at least one oil, in particular a cosmetic oil. It may also contain other fatty substances.

[0123] By “oil” is meant a non-aqueous compound, liquid at 25°C and atmospheric pressure (1,013.105 Pa), immiscible with water.

[0124] By "immiscible" is meant that the mixture of the same quantity of water and oil, after stirring, does not lead to a stable solution comprising only one phase, under the aforementioned temperature and pressure conditions. The observation is made by eye or by means of a phase contrast microscope if necessary, on 100g of mixture obtained after sufficient Rayneri agitation to create a vortex within the mixture (for information purposes 200 to 1000 rpm); the resulting mixture being left to stand, in a closed bottle, for 24 hours at room temperature before observation.

[0125] As oils which can be used in the composition of the invention, we can cite for example:

[0126] - hydrocarbon oils of animal origin, such as perhydrosqualene;

[0127] - hydrocarbon oils of vegetable origin, such as liquid triglycerides fatty acids containing 4 to 10 carbon atoms such as triglycerides of heptanoic or octanoic acids or, for example, sunflower, corn, soybean, pumpkin, grape seed, sesame, hazelnut, apricot, macadamia, arara, sunflower, castor, avocado oils, triglycerides of caprylic / capric acids 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, jojoba oil, shea butter oil;

[0128] - synthetic esters and ethers, in particular of fatty acids, such as oils of formulas R1COOR2 and R1OR2 in which RI represents the residue of a fatty acid containing from 8 to 29 carbon atoms, and R2 represents a hydrocarbon chain, branched or not, containing 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, isostearyl isostearate; hydroxylated esters such as isostearyl lactate, octylhydroxystearate, octyldodecyl hydroxystearate, diisostearylmalate, triisocetyl citrate, fatty alcohol heptanoates, octanoates, decanoates; polyol esters, such as propylene glycol dioctanoate, neopentyl glycol diheptanoate and diethylene glycol diisononanoate; and pentaerythritol esters such as pentaerythrityl tetraisostearate or dipentaerythrityl pentaisononanoate;

[0129] - linear or branched hydrocarbons, of mineral or synthetic origin, such as paraffin oils, volatile or not, and their derivatives, branched-chain hydrocarbon oils containing 10 to 20 carbon atoms such as isohexadecane, isododecane, isoparaffins and their mixtures, petroleum jelly, polydecenes, polyisobutenes, hydrogenated polyisobutenes such as, for example, Parléam® marketed by the company NIPPON OIL FATS, PANALANE H-300 E marketed by the company AMOCO, VISEAL 20000 marketed by the company SYNTEAL, REWOPAL PIB 1000 marketed by the company WITCO, or PARLEAM LITE marketed by NOF Corporation;

[0130] - partially hydrocarbon and / or silicone fluorinated oils such as those described in document JP-A-2-295912;

[0131] - silicone oils such as volatile or non-volatile polymethylsiloxanes (PDMS) linear or cyclic silicone chain, liquid or pasty at room temperature, in particular cyclopolydimethylsiloxanes (cyclomethicones) such as cyclohexasiloxane; polydimethylsiloxanes comprising alkyl, alkoxy or phenyl groups, pendant or at the end of the silicone chain, groups having from 2 to 24 carbon atoms; phenyl silicones such as phenyltrimethicones, phenyldimethicones, phenyltrimethylsiloxydiphenylsiloxanes, diphenyldimethicones, diphenylmethyldiphenyl trisiloxanes, 2-phenylethyltrimethylsiloxysilicates, and polymethylphenylsiloxanes; or

[0132] - their mixtures.

[0133] As indicated above, the composition according to the invention may comprise, in the oily phase, other fatty substances. Preferably, this fatty substance is chosen from fatty alcohols having from 8 to 26 carbon atoms, such as cetyl alcohol, stearyl alcohol, the mixture of cetyl alcohol and stearyl alcohol (cetyl-stearyl alcohol), octyldodecanol, 2-butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol, oleyl alcohol or linoleyl alcohol.

[0134] The amount of oily phase may range, for example, from 0.1 to 40% by weight, preferably from 0.5 to 35% by weight, preferably from 1% to 30% by weight relative to the total weight of the composition.

[0135] The composition of the invention may also contain adjuvants usual in the cosmetic and / or dermatological fields, such as active ingredients, preservatives, antioxidants, complexing agents, pH adjusters (acidic or basic), perfumes, odor absorbers or coloring materials (pigments and dyes).

[0136] The quantities of these different adjuvants are those conventionally used in the field considered, and for example from 0.01 to 20% of the total weight of the composition. These adjuvants, depending on their nature, can be introduced into the fatty phase and / or into the aqueous phase.

[0137] The present invention also relates to a cosmetic process for caring for keratin materials, preferably the skin, comprising the application to said keratin materials of a composition according to the invention.

[0138] The following examples of compositions according to the invention are given by way of illustration and without limitation.

[0139] The quantities are given in % by weight of the total weight of composition (% w / w), unless otherwise stated.

[0140] Example 1: Preparations and evaluations of compositions METHODS Optical microscopy

[0141] Microscopic observations were carried out at 25°C between slide and coverslip, using a Leica Zeiss microscope which is used in transmission (the light passes through the sample), or by reflection if the object is opaque. Haze measurement

[0142] Haze-Gard® (BYK Gardner) quantifies the perception of visual effects with objective measurements. It measures the intensity of light passing through a sample, which corresponds to the hemispherical (or total) transmittance. The higher the transmittance of a material, the more transparent it is.

[0143] The Haze-Gard® measures the Direct Transmittance (i.e. in the same direction as the incident ray) or Hemispherical Transmittance (in all directions in space, which is equivalent to the total transmittance) separately. The more hemispherical the transmittance of a material is compared to the direct transmittance, the more it has a "blurring" effect.

[0144] We define the Haze value (%) to highlight this relationship between hemispherical transmittance and direct transmittance. Thus, the higher a material's Haze value, the higher its "blur" (or soft focus) effect.

[0145] [Math.2] (%)=100 K (TH -HMH

[0146] The product is deposited in a controlled thickness of 25 μm using an automatic spreader (Byko drive®) on a transparent plastic film. After a drying time of 1 hour at room temperature and in the open air, the optical parameters (T, H, C) are measured using the Haze-Gard, at three separate points on the deposit in order to obtain an average. The state of the film is also characterized. For the measurements to be relevant, the deposit must be uniform, without streaks or heterogeneity. Opacity Measurement

[0147] The contrast ratio represents a measure of the covering power of the formula. To do this, a deposit is made on a glossy BYC contrast card (reference 2814 or 2830).

[0148] Once these deposits have been made, the tristimulus parameters XYZ and L*a*b* are measured on the white and black areas using the Minolta spectrometer.

[0149] From these parameters, we can then determine the contrast ratio (CR) which we define as:

[0150] [Math.3] y^y CR = — * 190

[0151] with YFN, the average Y value measured on the black background and YFB the average Y value measured on the white background. The higher this value, the more the product will tend to provide color coverage. Preparation of compositions

[0152] The compositions are prepared by mixing the ingredients mentioned in water. RESULTS (in vitro) Evaluation of the dispersion

[0153] Firstly, a macroscopic evaluation of the dispersion is carried out, after mixing the particles, the homogeneity of the bulk and the deposit is observed and the different formulas are noted according to their appearance.

[0154] The protocol used is as follows: the overall appearance of a quantity of formula of approximately 5 mL is evaluated (presence of inhomogeneity, grain, aggregate) then one gram of formula is taken and spread on the black part of a BYK contrast card using a glass slide. The presence or absence of aggregate / poorly dispersed grains of particles in the deposit is then observed. Indeed, good dispersion or poor dispersion can be observed.

[0155] Polymers outside the invention are marked with a star. Optical characterization

[0156] These compositions are characterized for their optical properties.

[0157] It is observed during the characterization of the optical properties of the different formulas presented previously that those containing the polymers of the invention allow better optical performances (Haze & CR).

[0158] The results of all the tests are summarized below:

[0159] Reference and comparative compositions (all outside the invention)

[0160] [Tables 1] Gel only Gel only Gel only Gel only Reference Reference Reference Reference Reference Glycerin 10 10 10 10 10 10 10 10 Silica 2 0.5 Silica 1 - - - - 1 1 - 1 Hectorite 5 5 Pemulen* 0.85 0.85 Sepigel 2 2 Xanthan* 1.5 1.5 Gel appearance Soft gel Soft gel Soft gel Soft gel Good dispersion Good dispersion Good dispersion Haze 23.3 1.86 10.3 1.74 37.9 13.5 30 15.8 Contrast Ratio 3.34 1.06 1.78 1.06 4.96 1.95 2.59 2.45 Interest Gel reference Gel reference Gel reference Gel reference Particle outside the invention Particle outside the invention Particle outside the invention Particle outside the invention

[0161] KO = not OK

[0162] Silica 1 = RICESILK silica particles from Soliance, which are comparative and have a refractive index of 1.47 and a particle size of 10 pm

[0163] Silica 2 = NF Biosilica silica particles from NFC Corporation, which are comparative and have a refractive index of 1.45 and a particle size of 0.73 pm

[0164] Hectorite = marketed under the name Bentone Hydroclay™ 2000 LO by Elementis

[0165] Pemulen (excluding invention) = INCI name: ACRYLATES / C10-30 ALKYL ACRYLATE CROSSPOLYMER from Lubrizol

[0166] Sepigel = INCI name: POLYACRYLAMIDE (and) C13-14 ISOPARAFFIN (and) LAURETH-7 from SEPPIC

[0167] Xanthan (not the invention) = xanthan gum from CP KELCO (trade name KELTROL CG).

[0168] The comparative large RICESILK particles are well dispersed throughout the polymers.

[0169] Examples according to the invention and counter-examples

[0170] [Tables2] Example 1 Example 2 Example 5 Example 6 Counterexample Counterexample Counterexample Glycerin 10 10 10 10 10 10 10 Sunballoon HS-040 0.5 0.5 - - 0.5 0.5 Sunballoon HS-070 - - 0.5 0.5 0.5 Hectorite 5 5 Pemulen* 0.85 0.85 Sepigel 2 2 Xanthan* 0.84 Gel Appearance Good Dispersion Good Dispersion Good Dispersion Poor Dispersion Poor Dispersion Haze 54 34 55.3 56.7 9.3 18 34 Contrast Ratio 6.79 3.73 5.52 4.98 1.45 2.51 3.37 Interest OK OK OK OK KO KO KO

[0171] Sunballoon HS-040 = hollow silica particles according to the invention marketed by AGC

[0172] Sunballoon HS-070 = hollow silica particles according to the invention marketed by AGC

[0173] Hectorite = marketed under the name Bentone Hydroclay™ 2000 LO by Elementis

[0174] Pemulen (excluding invention) = INCI name: ACRYLATES / C10-30 ALKYL ACRYLATE CROSSPOLYMER from Lubrizol

[0175] Sepigel = INCI name: POLYACRYLAMIDE (and) C13-14 ISOPARAFFIN (and) LAURETH-7 from SEPPIC

[0176] Xanthan (outside the invention) = xanthan gum from CP KELCO (trade name KELTROL CG).

[0177] With particles according to the invention, different states of aggregation can be observed.

[0178] It is observed that in the case of small, well-dispersed particles (Sunballoon HS-040 in hectorite or in Sepigel) a significant increase in opacity (Contrast Ratio SCE) as well as in the blurring potential (Haze) is observed. Indeed, a significant performance delta is observed between the control bases (outside the invention) and the bases with well-dispersed particles (invention). It is also observed that in the case of poor dispersion, the optical properties are not expressed to their full potential: for example with Sunballon HS-040 in Pemulen-glycerin gel: CR SCE of 1.45 and Haze of 9.3.

[0179] Furthermore, the use of comparative particles of larger size (Ricesilk comparative silica of table 1) but not meeting the specifications of the invention (i.e. refractive index and size), does not present a dispersion problem; however the properties in terms of opacity are not as effective (CR ~ 1-1.5).

[0180] Other examples according to the invention

[0181] [Tables3] Example 1 Example 2 Example 3 Example 4 Example 5 Example 8 Example 9 Glycerin 10 10 10 10 10 10 10 Sunballoon HS-040 0.5 0.5 0.5 0.5 0.5 - Sunballoon HS-070 - - 0.5 0.5 Bentonite 5 Hectorite 5 5 Sepigel 2 2 Biosaccharide 1 Starch 4.5 Gel appearance Good dispersio n Good dispersio n Good dispersio n Good dispersio n Good dispersio n Good dispersio n Good dispersio n Interest OK OK OK OK OK OK OK

[0182] Counterexamples to the examples in Table 3

[0183] [Tables4] Counter-exe sample Counter-exe sample Counter-exe sample Counter-exe sample Counter-exe sample Glycerin 10 10 10 10 10 10 Sunballoon HS-040 0.5 0.5 0.5 Sunballoon HS-070 0.5 0.5 Silica 2 0.5 Pemulen* 0.85 0.85 0.85 Xanthan* 0.84 1.5 HEC* 2 Gel appearance Poor dispersion Presence of aggregates Poor dispersion Presence of aggregates Poor dispersion Presence of aggregates Poor dispersion Presence of aggregates Poor dispersion Presence of aggregates Poor dispersion Presence of aggregates Poor dispersion Presence of aggregates Interest KO KO KO KO KO KO

[0184] KO = not OK

[0185] Sunballoon HS-040 = hollow silica particles according to the invention marketed by AGC

[0186] Sunballoon HS-070 = hollow silica particles according to the invention marketed by AGC

[0187] Silica 2 = NF Biosilica silica particles from NFC Corporation, which are comparative and have a refractive index of 1.45 and a D

[50] size of 0.73 pm

[0188] Bentonite = marketed by Kunimine

[0189] Hectorite = marketed under the name Bentone Hydroclay™ 2000 LO by Elementis

[0190] Sepigel = INCI name: POLYACRYLAMIDE (and) C13-14 ISOPARAFFIN (and) LAURETH-7 from SEPPIC

[0191] Starch = INCI name: HYDROXYPROPYL STARCH PHOSPHATE from Cargill (88% by weight of hydroxypropyl starch phosphate and 12% by weight of water)

[0192] Pemulen (not for invention) = INCI name: ACRYLATES / C10-30 ALKYL ACRYLATE CROSSPOLYMER from Lubrizol

[0193] Biosaccharide = Fucogel 1000 from Solabia (CTFA name Biosaccharide gum-1)

[0194] HEC (excluding invention) = hydroxyethylcellulose

[0195] Xanthan (not the invention) = xanthan gum from CP KELCO (trade name KELTROL CG).

[0196] It emerges from these results that only compositions comprising a gelling agent chosen from homo- and copolymers comprising a 2-acrylamido-2-methyl-propanesulfonic acid monomer, clays, polysaccharides consisting solely of glucose and polysaccharides rich in fucose, and particles having a primary particle size of between 100 nm and 5 pm and having a refractive index of less than 1.3 exhibit both good dispersion and the desired optical properties.

[0197] Example 2: impermeable nature of the particles according to the invention a. First tests:

[0198] The composition of Example 2a according to the invention and the comparative counter-example below were prepared by mixing the ingredients in water, then the evaluation of the appearance of the gel obtained and the Haze and Contrast Ratio measurements, according to the protocols of Example 1, were carried out.

[0199] [Tables5] Example 2a Counterexample Glycerin 10 10 Silica particles according to the invention (Sunballoon HS-040 from AGC SLTECH) 0.5 - Comparative permeable hollow silica particles - 0.5 Polyacrylamide / Ci3-Ci4 Iso-paraffin / Laureth-7) (Sepigel 305 from Seppic) 2 2 water Qsp 100 Qsp 100 Gel appearance Good dispersion Good dispersion Haze 34 18.2 Contrast Ratio 3.73 2.25 Interest OK Outside the invention

[0200] The results show that only the composition of example 2a according to the invention, comprising a copolymer-type gelling agent comprising an acid monomer 2-acrylamido-2-methyl-propane sulfonic acid and particles with a primary particle size between 100 nm and 5 pm and a refractive index of less than 1.3, exhibits both good dispersion and the desired optical properties (Haze and Contrast Ratio higher than the counterexample). a. Second tests: tests outside the invention

[0201] The comparative test compositions A and B below were prepared by mixing the particles in water.

[0202] [Tableauxô] Test A Test B Silica particles according to the invention (Sunballoon HS-040 from AGC SLTECH) 1 - Comparative permeable hollow silica particles - 1 Water Qsp 100 Qsp 100

[0203] Microscopy images were taken to define the permeability. For this, optical microscopy was carried out on each test A and B: the observation is carried out at D+1 and the contrast between the particle and the solvent is observed. In the case where the particle is impermeable, the contrast is kept high; conversely, there is a significant loss of contrast between the two phases in the case of porous particles.

[0204] The results show that for the silica particles according to the invention (Sunballoon HS-040 from AGC SLTECH) in water (test A), the contrast between the two phases is high. On the other hand, for the comparative permeable hollow silica particles, a significant loss of contrast between the two phases is observed.

Claims

Claims

1. Composition comprising, in a physiologically acceptable medium: - at least one gelling agent chosen from homo- and copolymers comprising a 2-acrylamido-2-methyl-propanesulfonic acid monomer, clays, polysaccharides consisting solely of glucose, polysaccharides rich in fucose and mixtures thereof; and - at least one hollow silica particle comprising a shell containing silica and a hollow space inside the shell, said particle having a size between 100 nm and 5 pm and having a refractive index of less than 1.

3.

2. Composition according to claim 1, characterized in that it comprises a concentration of gelling agent in active material ranging from 0.1 to 20% by weight relative to the total weight of the composition, and preferably from 0.5 to 15% by weight, preferably from 0.5 to 10% by weight and even more particularly from 0.5 to 5% by weight.

3. Composition according to claim 1 or 2, characterized in that the homo- or copolymer comprising a 2-acrylamido-2-methylpropanesulfonic acid monomer is chosen from crosslinked and neutralized homopolymers of 2-acrylamido-2-methylpropanesulfonic acid and copolymers of acrylamido-2-methylpropanesulfonic acid or its salts and one or more non-ionic, crosslinked or non-crosslinked monomers, preferably chosen from crosslinked and neutralized homopolymers of 2-acrylamido-2-methylpropanesulfonic acid, copolymers of acrylamido-2-methylpropanesulfonic acid and vinylpyrrolidone, crosslinked acrylamide / sodium acrylamido-2-methylpropanesulfonate copolymers, copolymers of acrylamido-2-methylpropanesulfonic acid and hydroxyethyl acrylate and hydrophobically modified acrylamido-2-methyl propane sulfonic acid copolymers.

4. Composition according to claim 1 or 2, characterized in that the clay is chosen from montmorillonites, hectorites, bentonites, beidellites, saponites and their mixtures, preferably it is chosen from montmorillonite, bentonite, hectorite, attapulgite, sepiolite and their mixtures, preferably it is a bentonite or a hectorite.

5. Composition according to claim 1 or 2, characterized in that the po- lysaccharide consisting solely of glucose is selected from sclerotium gum and modified or unmodified starches; preferably selected from sclerotium gum and unmodified starches such as unmodified corn starches, unmodified rice starches or hydroxypropyl ethers of distarch phosphate.

6. Composition according to claim 1 or 2, characterized in that the fucose-rich polysaccharide is a polymer containing fucose, galactose and galacturonic acid.

7. Composition according to one of the preceding claims, characterized in that the particle has a size of between 100 nm and 3 pm, preferably between 150 nm and 1 pm, preferably between 200 nm and 900 nm, preferably between 300 nm and 800 nm.

8. Composition according to one of the preceding claims, characterized in that the particle has a refractive index of between 1 and 1.3; preferably, the particle has a refractive index of between 1.1 and 1.

3.

9. Composition according to one of the preceding claims, characterized in that the particle is hollow and is in the form of a spherical envelope around a single hollow space; preferably, the envelope of the particle is impermeable to the rest of the composition, i.e. the envelope is impermeable to the other ingredients of the composition, in particular impermeable to water, oil and solvents possibly present in the composition.

10. Composition according to one of the preceding claims, characterized in that it comprises from 0.1 to 20% by weight of particles relative to the total weight of the composition, and preferably from 0.2 to 10% by weight, preferably from 0.3 to 7% by weight and even more particularly from 0.4 to 3% by weight.

11. Composition according to one of the preceding claims, characterized in that it comprises an aqueous phase comprising water and optionally an organic solvent soluble in water, at 25°C, chosen for example from polyols; linear or branched C2-C4 alkanols, such as ethanol and isopropanol, propanol, butanol; and mixtures thereof; and / or an oily phase.

12. Composition according to one of the preceding claims, characterized in that it is an oil-in-water emulsion.

13. Cosmetic process for caring for keratin materials, preferably the skin, comprising the application to said keratin materials of a composition according to one of the preceding claims.