FR3075635A1 - PROCESS FOR THE PREPARATION OF ANHYDROUS SPHEROIDS BY CRYOGENICITY - Google Patents

Abstract

The invention relates to a process for preparing anhydrous spheroids having a diameter of 0.1 to 10 mm by cryogenic treatment, as well as to anhydrous spheroids obtained by this process. The invention also relates to the use of such spheroids in cosmetic compositions for makeup and / or skin care.

Description

The invention relates to a process for the preparation of anhydrous spheroids by cryogenics, as well as to the spheroids obtained by this process. The invention also relates to the use of these anhydrous spheroids in cosmetic compositions for make-up and / or care. Finally, the invention relates to a cosmetic composition for care and / or for make-up comprising anhydrous spheroids according to the invention dispersed in a continuous phase immiscible with said spheroids.

PRIOR STATE OF THE ART AND PURPOSE OF I NVENTI ON

The preparation of cosmetic compositions consisting of a lipid matrix, solid at room temperature, is particularly complex when it is desired to obtain objects of very small size, of the order of a few millimeters, of regular shape and reproducible at a very large number of 'visually identical copies.

The conventional shaping processes consisting of pouring a composition hot into a mold and then cooling them are not suitable for manufacturing very small objects on an industrial scale.

In addition, molded cosmetic products usually have at least one flat surface so that they can be placed at the bottom of a bucket or be attached to a mechanism such as lipsticks.

We cannot therefore resort to this type of process when we seek to obtain very small spheroids.

Other methods of forming lipid particles are known, such as air bed spraying methods which make it possible to prepare powders, but it is in this case difficult to obtain monodisperse and regular shaped spheroids. To date, the methods for obtaining spheroids of a size between 0.1 and 10 mm consist in coating a core with one or more successive coating layers, but the result in this case is not matrix type.

To date, therefore, it has never been possible to obtain anhydrous matrix type spheroids.

Another technical problem underlying the present invention is to obtain anhydrous spheroids consisting of a lipid matrix, the texture of which is both sufficiently hard at room temperature to maintain its shape, and at the same time sufficiently flexible to deform and crush to be applied to the skin by a shearing movement using a finger.

A third technical problem underlying the invention is to obtain anhydrous spheroids consisting of a lipid matrix which can be dispersed in a continuous phase in which the lipid matrix is immiscible, said spheroids being sufficiently hard at temperature. ambient to maintain their shape and integrity, without them deforming or releasing material in the continuous phase immiscible with said spheroids. EP 2 979 690 describes a process for preparing round beads comprising an aqueous emulsion phase of the water-in-oil or oil-in-water type, which are then coated with a solid material for better stabilization over time. This process does not allow the manufacture of anhydrous solid beads. It is in this context that the Inventors have succeeded, quite surprisingly, in manufacturing anhydrous matrix type spheroids with a size between 0.1 and 10 mm, solid at room temperature. The spheroids of the invention are prepared according to a simplified process which can be used on an industrial scale and does not require specific storage conditions. The spheroids obtained according to this process have a regular appearance, a smooth surface and a uniform volume. They also consist of a lipid matrix whose texture at room temperature is sufficiently flexible and deformable to be able to be applied easily to the skin by low shear, for example using the fingers, and thus produce a care effect or of makeup on the skin.

The inventors have finally observed that the anhydrous spheroids of the invention can be dispersed directly in a continuous phase in which the lipid matrix is not miscible, without it being necessary to protect them by an external coating layer, so that it is possible to obtain new cosmetic compositions combining in themselves textures and performances which are difficult to combine by conventional techniques, such as freshness and shine, freshness and hold, shine and hold. The cosmetic compositions thus obtained, which comprise a continuous phase in which the spheroids of the invention are dispersed, have an original visual appearance. It is indeed possible to disperse in a transparent continuous phase a mixture of spheroids of several colors which, at the time of application, under the effect of a shear, mix with each other and with the continuous phase to form a single hue. These compositions finally produce a surprising texture at the time of application to the skin, the two phases (the anhydrous spheroids and the immiscible continuous phase in which they are dispersed) can mix in situ, emulsify or remain incompatible to accentuate a performance, such as a shine or freshness property on the surface of the skin. We can thus observe the transformation of the compositions into cream and / or the transformation of a mixture of different colors into a single uniform shade, the cosmetic composition of the invention having surprising new sensorialities due to the simultaneous contact of these two non-contact phases. miscible with the skin.

DESCRI PTI ON FROM I NVENTI ON

According to a first aspect, the subject of the present invention is a process for the preparation of anhydrous spheroids, said process comprising the following steps: (i) preparation of a cosmetically acceptable lipid matrix comprising: (a) at least one hydrocarbon-based oil and / or silicone, and optionally a gelling agent for said hydrocarbon and / or silicone oil, and / or (b) at least one wax, (ii) cryogenic treatment of the lipid matrix obtained at the end of step (i) to obtain anhydrous spheroids, solid at room temperature, having a diameter of 0.1 to 10 mm.

For the purposes of the invention, the term “lipid matrix” means a homogeneous composition (that is to say one not comprising a coating layer around a core) based on fatty substances, that is to say ie comprising (a) at least one hydrocarbon and / or silicone oil, and / or (b) at least one wax.

The inventors have observed that the cryogenic treatment of a lipid matrix as defined according to the invention makes it possible to obtain anodic monodisperse spheroids (of a single size) exhibiting good behavior, without it being necessary to coat them with '' an external protective layer.

According to a preferred embodiment, the method of the invention comprises the following steps: (i) preparation of a cosmetically acceptable lipid matrix comprising: (a) from 5 to 99.5% by weight of at least one hydrocarbon-based oil and / or silicone, and optionally a gelling agent for said hydrocarbon and / or silicone oil, and (b) from 0.5 to 95% by weight of at least one wax, (ii) cryogenic treatment of the lipid matrix obtained with after step (i) to obtain anhydrous spheroids, solid at room temperature, having a diameter of 0.1 to 10 mm.

The method of the invention consists of a first step (i) of preparation of a cosmetically acceptable lipid matrix, by mixing, with stirring, of the components constituting this lipid matrix, that is to say: (a) at least one oil hydrocarbon and / or silicone, and optionally a gelling agent for said hydrocarbon and / or silicone oil, and / or (b) at least one wax, said lipid matrix possibly comprising other components, such as pigments or nacres, fillers, film-forming polymers.

Advantageously, the cosmetically acceptable lipid matrix comprises: (a) from 5 to 99.5% by weight of at least one hydrocarbon and / or silicone oil, and optionally a gelling agent for said hydrocarbon and / or silicone oil, and (b ) from 0.5 to 95% by weight of at least one wax.

The oil (s) (a), and optionally the gelling agent of said hydrocarbon and / or silicone oil, can be present at a content ranging from 5 to 99.5% by weight, preferably from 10 to 95% by weight, more preferably from 20 to 90% by weight, even more preferably from 30 to 85% by weight, and even more preferably from 40 to 80% by weight, relative to the total weight of the lipid matrix. The oil (a) can be a hydrocarbon oil chosen from volatile and / or non-volatile hydrocarbon oils. Preferably, it is a mixture of hydrocarbon oils.

For the purposes of the invention, the term "hydrocarbon-based oil" means an oil containing mainly carbon and hydrogen atoms, and optionally oxygen, nitrogen, sulfur, phosphorus atoms.

A volatile hydrocarbon oil within the meaning of the invention is an oil capable of evaporating on contact with the skin in less than an hour, at room temperature and atmospheric pressure. The volatile oil or oils of the invention are oils that are liquid at room temperature, having a non-zero vapor pressure, at room temperature and atmospheric pressure, ranging in particular from 0.13 Pa to 40,000 Pa (103 to 300 mm Hg), in particular ranging from 1.3 Pa to 13,000 Pa (0.01 to 100 mm Hg), and more particularly ranging from 1.3 Pa to 1300 Pa (0.01 to 10 mm Hg). The term “non-volatile hydrocarbon-based oil” means an oil which remains on the skin at room temperature and atmospheric pressure for at least several hours and which in particular has a vapor pressure of less than 0.13 Pa (10 3 mm Hg).

The volatile hydrocarbon oils of the invention are advantageously chosen from hydrocarbon oils comprising from 8 to 16 carbon atoms, and in particular branched alkanes comprising from 8 to 16 carbon atoms such as isoalkanes comprising from 8 to 16 carbon atoms (called also isoparaffins) of petroleum origin such as isododecane (also called 2,2,4,4,6-pentamethylheptane), isodecane, isohexadecane, and for example the oils sold under the trade names of Isopars or Allowyls, branched esters comprising from 8 to 16 carbon atoms such as isohexyl neopentanoate, and their mixtures. Other volatile hydrocarbon oils such as petroleum distillates, in particular those sold under the name Shell Either by the company SHELL, can also be used. The volatile hydrocarbon oils can also be chosen from linear alkanes comprising from 8 to 16 carbon atoms. As an example of a linear alkane comprising from 8 to 16 carbon atoms, there may be mentioned n-nonadecane (Cg), n-decane (Qo), n-undecane (Cu), n-dodecane ( C2), n-tridecane (Ci3), n-tetradecane (Ci4), n-pentadecane (Cs), n-hexadecane (Ce), and their mixtures, and in particular the mixture of n-undecane (Ci ) and n-tridecane (C3) sold under the reference CETIOL UT by the Cognis Company.

According to one embodiment, a volatile linear alkane suitable for the invention can be chosen from n-nonadecane, n-undecane, n-dodecane, n-tridecane, and their mixtures.

The volatile hydrocarbon oils of the invention are advantageously chosen from volatile hydrocarbon oils comprising from 8 to 16 carbon atoms, and their mixtures.

As non-volatile hydrocarbon oils, mention may in particular be made of: hydrocarbon oils of vegetable origin such as fatty acid and glycerol triesters, the fatty acids of which contain from 4 to 24 carbon atoms, these oils possibly being linear or branched, saturated or unsaturated. These oils are advantageously oils of wheat germ, sunflower, grapeseed, sesame, corn, apricot, castor, shea, avocado, olive, soybean oil. almond, palm, rapeseed, cotton, hazelnut, macadamia, jojoba, alfalfa, poppy, pumpkin, sesame, squash, rapeseed, blackcurrant, evening primrose, millet, barley, quinoa, rye, safflower, bancoulier, passionflower, muscat rose; or caprylic / capric acid triglycerides such as those sold by the company Stéarineries Dubois or those sold under the names Miglyol 810, 812, 818 and 829 by the company Dynamit Nobel; or linear or branched hydrocarbons, comprising from 4 to 24 carbon atoms, of mineral or synthetic origin such as petrolatum, polydecenes, hydrogenated polyisobutene such as Parleam®, squalane, and their mixtures; synthetic esters such as, for example, Purcellin ™ oil (cetostearyl octanoate), isopropyl myristate, isopropyl palmitate, alcohol benzoate comprising from 12 to 15 carbon atoms, hexyl laurate , diisopropyl adipate, isononyl isononanoate, 2-ethylhexyl palmitate, isostearate isostearate, octanoates, decanoates or ricinoleates of alcohols or polyalcohols such as propylene glycol dioctanoate; hydroxylated esters such as isostearyl lactate, di-isostearyl malate; and pentaerythritol esters; fatty alcohols liquid at room temperature with branched and / or unsaturated carbon chain comprising from 12 to 26 carbon atoms such as octyl dodecanol, isostearyl alcohol, oleic alcohol, 2-hexyldecanol, 2-butyloctanol, 2- undecylpentadecanol; higher fatty acids such as oleic acid, linoleic acid, linolenic acid; carbonates, acetals, citrates, and mixtures thereof. The oil (a) can be a silicone oil chosen from volatile and / or non-volatile silicone oils. Preferably, it is a mixture of silicone oils.

As volatile silicone oils, mention may be made of volatile silicones, such as, for example, volatile linear or cyclic silicone oils, having in particular from 2 to 7 silicon atoms, these silicones optionally comprising alkyl or alkoxy groups comprising from 1 to 10 atoms of carbon. As volatile silicone oils which can be used in the context of the invention, mention may preferably be made of cyclopentadimethylsiloxane, octamethyl cyclotetrasiloxane, decamethyl cyclopentasiloxane, dodecamethyl cyclohexasiloxane, heptamethyl hexyltrisiloxane, heptamethylaneilanehexylisane hexyl octamethyl trisiloxane, decamethyl tetrasiloxane, dodecamethyl pentasiloxane, and mixtures thereof.

Mention may also be made of linear volatile alkyltrisiloxane oils chosen from 3-butyl-1,1,1,3,5,5,5-heptamethyl trisiloxane, 3-propyl-1,1,1,3,5,5, 5-heptamethyl trisiloxane, and 3-ethyl-1,1,1,3,5,5,5-heptamethyl trisiloxane, and mixtures thereof. The preferred volatile silicone oil is cyclopentadimethylsiloxane.

The non-volatile silicone oils which can be used in the composition according to the invention can be polydimethylsiloxanes (PDMS) comprising at least one alkyl or alkoxy group advantageously comprising from 12 to 24 carbon atoms, during and / or at the end of the silicone chain, the phenylated silicones such as phenyl trimethicones, phenyl dimethicones, phenyl trimethylsiloxy diphenylsiloxanes, diphenyl dimethicones, diphenyl methyldiphenyl trisiloxanes, 2-phenylethyl trimethylsiloxysilicates.

According to one embodiment, the oil (a) is a mixture of at least one hydrocarbon-based oil and at least one silicone oil.

When the lipid matrix of the invention does not comprise wax (b), the oil (s) (a) are combined with at least one gelling agent for said oils. The gelling agent for hydrocarbon and / or silicone oil is preferably chosen from silicas, clays, optionally modified hectorites, dextrin esters, polyamides or silicone polyamides, amides of L-glutamic acid or aspartic acid, the hydrocarbon block copolymers comprising at least one styrene unit.

Within the meaning of the invention, the hectorites can be hectorites modified with a quaternary alkylammonium chloride, preferably an ammonium substituted with at least one, preferably at least two alkyl groups comprising from 14 to 20 carbon atoms. The alkyl can advantageously be stearyl. Mention will be made of the compound bearing the name INCI disteardimonium hectorite in which the ammonium comprises two methyl groups and two stearyl groups.

Within the meaning of the invention, the dextrin esters are dextrin and fatty acid esters comprising from 12 to 24 carbon atoms, preferably comprising from 14 to 22 carbon atoms, and even more preferably comprising from 14 to 18 carbon atoms. Preferably, the dextrin esters are chosen from dextrin myristate, dextrin palmitate, and their mixture.

Within the meaning of the invention, the amides of L-glutamic acid (glutamides) or of aspartic acid preferably comprise at least one alkyl group comprising from 6 to 14 carbon atoms, for example 8 or 12 carbon atoms . Such an amide of glutamic acid is for example described in patent FR 2 820 739. The glutamides are preferably chosen from dibutyl lauroyl glutamide, dibutyl ethylhexanoyl glutamide, and their mixtures, and may for example be one of the products of brands EB-21, GP-1, AJK-OD2046, AJK-BG2055 and AJK-CE2046 manufactured by the company Ajinomoto. Glutamide is for example chosen from dibutyl lauroyl glutamide and dibutyl ethylhexanoyl glutamide, or mixtures thereof. The amide or the mixture of amides, in particular of glutamide (s), represents for example between 0.1% and 15.0% by weight, between 1.0% and 15.0% by weight, between 0.5 % and 8.0% by weight, between 1.0% and 5.0% by weight, between 0.8% and 5% by weight, see between 2.0 and 3.0% by weight relative to the total weight of the lipid matrix.

Within the meaning of the invention, the hydrocarbon block copolymers comprising at least one styrene unit are preferably block copolymers of styrene and olefin, such as for example the copolymers comprising at least one styrene unit and a unit chosen from butadiene, ethylene, propylene, butylene, isoprene, and mixtures thereof. The hydrocarbon block copolymers of the invention are advantageously chosen from styrene-ethylene / propylene copolymers, styrene-ethylene / propylene-styrene copolymers, styrene-ethylene / butadiene-styrene copolymers, styrene-isoprene copolymers styrene, styrene-butadiene-styrene copolymers, styrene-ethylene / butylene-styrene copolymers, styrene / methylstyrene / indene copolymers, and mixtures thereof.

The wax (es) (b) used in the process of the invention may be a lipophilic compound, solid at room temperature, with reversible solid / liquid state change, having a melting temperature above 30 ° C., preferably ranging from 50 to 120 ° C, more preferably from 60 to 110 ° C, and even more preferably from 70 to 100 ° C. Within the meaning of the invention, the melting temperature corresponds to the temperature of the most endothermic peak observed in thermal analysis (DSC) as described in standard NF EN ISO 11357-3. The melting temperature of the wax can be measured using a differential scanning calorimeter (DSC), for example the calorimeter sold under the name DSC Metler Toledo.

It is advantageously possible to form mixtures of waxes by combining waxes with a high melting temperature, that is to say one with a melting temperature above 50 ° C., preferably above 70 ° C., with waxes having lower melting temperatures, that is to say of which the melting temperature is less than 50 ° C, preferably less than or equal to 40 ° C. The mixture of waxes having a high melting temperature with waxes having a low melting temperature allows the texture of the spheroids to be adapted so that they produce a comfortable application on the skin.

The lipid matrix can advantageously be characterized by a melting point (or drop point) greater than 30 ° C, preferably ranging from 50 to 120 ° C, more preferably from 60 to 110 ° C, and even more preferably from 70 to 100 ° C. The melting point of the lipid matrix corresponds to the temperature at which the first drop of lipid matrix appears when it is heated.

The wax (es) (b) used in the context of the invention can be chosen from solid, room temperature waxes of animal, vegetable, mineral or synthetic origin, and mixtures thereof.

Advantageously, the wax (es) (b) of the invention can be chosen from: hydrocarbon waxes such as beeswax, lanolin wax, and Chinese insect waxes, rice bran wax, Carnauba wax, Candellila wax, Ouricury wax, Alfa wax, cork fiber wax, sugar cane wax, berry wax, shellac wax, Japanese wax, sumac wax, montan wax, orange and lemon waxes, paraffins and ozokerite, polymethylene, polyethylene, polypropylene waxes and their ethylene / propylene copolymers, waxes obtained by catalytic hydrogenation d '' animal or vegetable oils having fatty chains, linear or branched, comprising from 8 to 22 carbon atoms, such as isomerized jojoba oil, hydrogenated sunflower oil, hydrogenated castor oil, coconut oil hydrogenated, hydrogenated lanolin oil, di-tetrastearate thylol-1,1,1-propane) and di- (trimethylol-1,1,1-propane) tetrabehenate; fatty alcohol waxes chosen from saturated or unsaturated fatty alcohols, branched or not, comprising from 20 to 60 carbon atoms, silicone waxes, such as alkyl- or alkoxy-dimeticones comprising from 16 to 45 carbon atoms, or fluorinated waxes, and mixtures thereof.

According to a particularly advantageous embodiment, the wax (es) (b) are hydrocarbon waxes such as Microcrystalline Wax SP-88 and

Microcrystalline Wax SP-16 W (Strahl and Pitsch Inc.), and / or polyethylene waxes such as Jeenate® (Jeen International Corporation) and Performalene® (Baker Hughes) waxes, hydrocarbon waxes being the most preferred. The hydrocarbon waxes of the invention are advantageously waxes comprising from 18 to 60 carbon atoms.

The content of wax (es) (b) can vary from 0.5 to 95% by weight, preferably from 3 to 90% by weight, preferably from 3 to 60% by weight, more preferably from 4 to 45% by weight. weight, and even more preferably from 5 to 30% by weight, relative to the total weight of the lipid matrix.

The lipid matrix can also comprise at least one pigment or a nacre, preferably an organic or inorganic pigment. The pigment or mother-of-pearl may have been surface treated, that is to say having undergone one or more surface treatments of a chemical, electronic, mechanochemical and / or mechanical nature.

The pigment or mother-of-pearl content advantageously varies from 0 to 20% by weight, and preferably from 2 to 10% by weight, relative to the total weight of the lipid matrix.

The spheroids of the invention may also include other components, such as fillers, film-forming polymers, etc.

The fillers can be mineral or organic, and of all shapes, platelet, spherical or oblong.

The fillers are chosen in particular from inorganic fillers such as: - talc, preferably in the form of particles generally of dimensions less than 40 μm; - Micas of natural or synthetic origin having dimensions of 2 to 200 µm, preferably 5 to 70 µm and a thickness of 0.1 to 5 µm, preferably 0.2 to 3 µm; - kaolin having particle sizes generally less than 30 μm; - metallic soaps derived from organic carboxylic acids having from 8 to 22 carbon atoms, preferably from 12 to 18 carbon atoms, for example zinc stearate, magnesium stearate or lithium stearate, zinc laurate , magnesium myristate, preferably in the form of particles having dimensions less than 10 µm; - zinc oxides, titanium oxides; calcium carbonate; magnesium carbonate, magnesium hydrocarbonate, silica, glass beads, ceramic beads; - and their mixtures.

Organic fillers can also be used as fillers such as: - crosslinked or non-crosslinked starches, for example corn, wheat or rice starches; - synthetic polymer powders, crosslinked or not, spheronized or not, expanded or not, such as polyethylene powders, polyester powders (for example isophthalate or terephthalate), polyamide powders (for example polyamide powders · -Alanine and nylon powders such as those sold under the name ORGASOL®), poly (meth) acrylic acid or poly (meth) acrylate powders such as crosslinked methyl methacrylate powders, polyurethane powders such as the copolymers of hexamethylene diisocyanate and of trimethylol hexyl lactone sold under the names PLASTIC POWDER® D-400 and PLASTIC POWDERf® D-800 by the company TOSHIKI, polystyrene powders crosslinked by divinylbenzene, powders of silicone resin such as silsesquioxanes, or tetrafluoroethylene powders (Teflon®); and - their mixtures.

The term “film-forming polymer” is intended to mean a polymer capable of forming a continuous film on a support. The film-forming polymer can be of natural or synthetic origin, and is advantageously chosen from: trimethylsiloxysilicates, phenylalkylsiloxysilicates in which the alkyl group preferably comprises from 1 to 6 carbon atoms, such as phenylpropyldimethylsiloxysilicate, silicone acrylate polymers such as acrylate / dimethicone copolymers, and in particular acrylate / dimethicone copolymers in cyclopentasiloxane (such as KP-545 from Shin-Etsu), acrylate / dimethicone copolymers in methyltrimethicone (such as KP-579 from Shin-Etsu ), acrylate / dimethicone copolymers in isododecane (such as for example KP-550 from Shin-Etsu); acrylate / polytrimethylsiloxy-methacrylate copolymers, and in particular acrylate / polytrimethylsiloxy-methacrylate copolymers in dimethicone (such as for example FA-4003 DM from Dow Corning®), acrylate / polytrimethylsiloxy-methacrylate copolymers in isododecane (such as example FA-4004 ID from Dow Corning®), polyalkylsilsesquioxanes comprising from 1 to 6 carbon atoms, and preferably polymethylsilsesquioxane (such as Silform® Flexible Resin from Momentive), trialkylsiloxysilylcarbamoyl pullulans in which the alkyl group comprises from 1 to 6 carbon atoms, and preferably trimethylsiloxysilylcarbamoyl pullulan (such as for example TSPL-30-ID from Shin-Etsu), copolymers of vinylpyrrolidone (VP), and preferably copolymers of VP and alkene comprising from 2 to 20 carbon atoms, such as copolymers of VP / eicosene, VP / vinyl acetate, VP / ethyl methacrylate, VP / methacry ethyl late / methacrylic acid, VP / hexadecene, VP / triacontane, VP / styrene, VP / acrylic acid / lauryl methacrylate, butylated polyvinylpyrrolidone (PVP), copolymers of a vinyl ester, and preferably acetate copolymers vinyl / allyl stearate, vinyl acetate / vinyl laurate, vinyl acetate / vinyl stearate, vinyl acetate / octadecene, vinyl acetate / octadecylvinyl ether, vinyl propionate / allyl laurate, vinyl propionate / laurate vinyl, vinyl stearate / octadecene-1, vinyl acetate / dodecene-1, vinyl stearate / ethylvinyl ether, vinyl propionate / cetyl vinyl ether, vinyl stearate / allyl acetate, 2,2-dimethyl octanoate vinyl / vinyl laurate, allyl dimethyl-2,2-pentanoate / vinyl laurate, vinyl dimethyl propionate / vinyl stearate, allyl dimethyl propionate / vinyl stearate, polyolefins, hydrogenated or non-hydrogenated, and preference polymers or copolymers of alkenes comprising from 2 to 20 carbon atoms, such as polybutenes, polyisobutenes, polydecenes, alkylcelluloses, and preferably alkylcelluloses carrying an alkyl group comprising from 2 to 6 carbon atoms, such as ethylcellulose and propylcellulose, polyvinyl alcohols, and mixtures thereof.

The film-forming polymer is preferably chosen from silicone polymers such as trimethylsiloxysilicates; phenylalkylsiloxysilicates in which the alkyl group preferably comprises from 1 to 6 carbon atoms such as phenylpropyldimethylsiloxysilicate; and vinylpyrrolidone copolymers.

The lipid matrix obtained at the end of step (i) is made liquid before the cryogenic treatment by heating at a temperature preferably ranging from 40 ° C to 110 ° C, more preferably from 50 to 100 ° C, and again more preferably from 60 to 90 ° C. Once in the liquid state, the lipid matrix is poured in the form of a drop into the cryogenic liquid to form anhydrous spheroids with a diameter of 0.1 to 10 mm. Stage (ii) of cryogenic treatment can be carried out by bringing the lipid matrix obtained at the end of stage (i) into contact with a cryogenic gas chosen from liquid nitrogen, liquid oxygen and liquid air, or with dry ice, or with a mixture chosen from ice / acetone or ice / alcohol mixtures comprising from 1 to 6 carbon atoms, such as for example the ice / ethanol mixture. The cryogenic gas is chosen according to the desired cooling temperature. Advantageously, the cryogenic treatment (ii) is carried out with a cryogenic gas whose temperature varies from -10 to -200 ° C, preferably from -15 to -180 ° C, and even more preferably from -20 to -150 ° C . Preferably, the cryogenic liquid is liquid nitrogen.

The treatment of the lipid matrix with the cryogenic liquid is preferably carried out by pouring the lipid matrix in liquid state dropwise into a closed reactor (closed system). The drip allows to calibrate the diameter of the drops so as to obtain spheroids having the qualities mentioned above. The reactor is advantageously filled entirely with cryogenic liquid so as to limit the distance between the needle and the surface of the cryogenic liquid, this in order to avoid an excessive drop of the lipid matrix drops in the cryogenic liquid.

The diameter of the nozzle allowing the flow of the lipid matrix in the cryogenic liquid is adapted to the diameter of the spheroids which it is desired to reach. The diameter of the nozzle preferably varies from 0.2 to 3 mm, more preferably from 0.2 to 1 mm, and is even more preferably from 0.5 mm.

The second subject of the invention relates to anhydrous spheroids having a diameter of 0.1 to 10 mm, solid at room temperature, obtained according to the method of the invention, said spheroids being made up of a cosmetically acceptable lipid matrix comprising: ( a) at least one hydrocarbon and / or silicone oil, and optionally a gelling agent for said hydrocarbon and / or silicone oil, and / or (b) at least one wax, said spheroids having a melting point above 50 ° C.

Within the meaning of the invention, the term "spheroid" refers to a small solid of essentially spherical shape, solid at room temperature, having the same composition throughout the spheroid. By ambient temperature is meant a temperature between 15 and 27 ° C, and more generally between 20 and 25 ° C. The diameter of the spheroids can vary from 0.1 to 10 mm, preferably from 0.3 to 8 mm, more preferably from 0.5 to 5 mm, and even more preferably from 1 to 3 mm, this diameter being an average diameter measured over ten measurements by conventional methods, for example using a binocular magnifier or a sieve. These spheroids preferably have a regular appearance, a smooth surface and a uniform volume.

Advantageously, the spheroids of the invention are free from any external coating intended to isolate the lipid matrix from the external medium (i.e. the continuous phase), having a composition different from that of the lipid matrix.

The term "anhydrous" means, in the context of the invention, that the water content within the object considered is preferably less than 1% by weight, preferably less than 0.5% by weight of said object .

Advantageously, the cosmetically acceptable lipid matrix of the spheroids of the invention comprises: (a) from 5 to 99.5% by weight of at least one hydrocarbon and / or silicone oil, and optionally a gelling agent for said hydrocarbon oil and / or silicone, and (b) from 0.5 to 95% by weight of at least one wax.

The oil (s) (a), and the gelling agent for these oils, constituting the lipid matrix of the spheroids of the invention, are as described above. The oil (s) (a) may be present in a content ranging from 5 to 99.5% by weight, preferably from 10 to 95% by weight, more preferably from 20 to 90%, even more preferably from 30 to 85% by weight, and even more preferably from 40 to 80% by weight, relative to the total weight of the lipid matrix.

The wax (es) (b) constituting the lipid matrix of the spheroids of the invention are as described above. The wax (es) (b) may be present at a content ranging from 0.5 to 95% by weight, preferably from 3 to 90% by weight, more preferably from 3 to 60% by weight, even more preferably from 4 to 45% by weight, and even more preferably from 5 to 30% by weight, relative to the total weight of the lipid matrix.

The spheroids of the invention are characterized by a melting point higher than 50 ° C, preferably ranging from 50 to 120 ° C, more preferably from 60 to 110 ° C, and even more preferably from 70 to 100 ° C.

The spheroids of the invention may also comprise at least one pigment or a nacre, preferably an organic or inorganic pigment, as described above. The pigment or mother-of-pearl content can vary from 0 to 20% by weight, and preferably from 2 to 10% by weight, relative to the total weight of the lipid matrix.

The spheroids of the invention obtained after step (ii) of cryogenic treatment can then be recovered cold, either to be used as such, or to prepare a cosmetic composition.

Thus, a third subject of the invention relates to the use of anhydrous spheroids according to the invention in cosmetic compositions for making up and / or caring for the skin of the body or of the face, and in particular of the lips.

A fourth object of the invention relates to a cosmetic makeup and / or care composition in which anhydrous spheroids according to the invention are in dispersion in a continuous phase immiscible with said spheroids.

Within the meaning of the invention, the expression “immiscible” means that the spheroids of the invention do not diffuse, disintegrate or swell, in the phase in which they are dispersed.

Depending on the intended final application, the cosmetic composition of the invention may contain cosmetic adjuvants well known in the cosmetic field.

In the cosmetic composition of the invention, the level by weight of anhydrous spheroids can represent from 5 to 70% by weight, preferably from 10 to 60% by weight, and even more preferably from 20 to 50% by weight, relative the total weight of the cosmetic composition.

The cosmetic composition of the invention is prepared according to a process comprising a step of dispersing the anhydrous spheroids of the invention in a continuous phase immiscible with said spheroids. The invention also relates to a lipstick and a foundation comprising a cosmetic composition according to the invention.

Finally, a final object of the invention relates to a process for making up and / or caring for the skin of the body or of the face, and in particular of the lips, comprising the following steps: (i ') removal of an amount of cosmetic composition according to the invention, in an amount necessary to carry out at least one application, (ii ') shear mixing of anhydrous spheroids with the immiscible continuous phase, contained in the cosmetic composition of the invention, and (iii') application of the cosmetic composition thus mixed on the skin of the body or of the face, and in particular of the lips. The shearing mixing step can be carried out directly on the skin of the body or the face (direct application), for example using the fingers, either beforehand, within a dispensing device such as a packaging containing the cosmetic composition of the invention (indirect application). In the latter case, the texture of the cosmetic composition can be distributed in the form of spheroids which are then crushed at the time of application or modified from spheroids in cream or gel within said dispensing device, before application to the skin.

In addition to the foregoing arrangements, the invention also comprises other arrangements which will emerge from the additional description which follows, which relates to the preparation of anhydrous spheroids according to the process of the invention and of cosmetic compositions comprising such spheroids, as well than Figures 1 and 2. EXAMPLES:

The different tests and measurement methods used in the examples are as follows:

Measurement of the average diameter of the spheroids: 24 hours after manufacture, ten or so spheroids are taken. Their diameters are measured with a binocular magnifier under a magnification x10, at room temperature. The average diameter of the spheroids represents the average of these ten measurements.

Melting point measurement:

During the preparation of the lipid matrix, a sample of this matrix is poured into a pierced reservoir. This tank is maintained at 20 ° C, at atmospheric pressure, for 24 hours. It is then placed in an oven, then heated at a heating rate of 1 ° C per minute. The melting point corresponds to the melting of the first drop of lipid matrix in the reservoir.

Stability test:

Stability is evaluated at different temperatures: at 4 ° C, at room temperature, and in the oven at 50 ° C, for a period of one month. EXAMPLE 1 Preparation of anhydrous spheroids according to the process of the invention

Table 1: Composition of the spheroids (composition A)

All the ingredients of composition A are dispersed in water at a temperature of 90 ° C. The mixture is kept at this temperature for 10 minutes, with stirring, until a homogeneous mixture is obtained. The mixture maintained at this same temperature, with stirring, is then poured dropwise using a nozzle of 0.5 mm in diameter into a vase cooled to a temperature of -150 ° C and filled with liquid nitrogen, with stirring. The droplets solidify immediately on contact with the cryogenic liquid, to form solid spheroids. The spheroids are then separated by filtration on a molecular sieve, then dried at room temperature.

Characterization of the spheroids: - Melting point: 81 ° C, - Average diameter: 2.5 mm. EXAMPLE 2 Preparation of a lipstick composition comprising anhydrous spheroids according to the invention in a continuous silicone phase

A silicone-immiscible continuous phase is prepared by mixing the various ingredients listed in Table 2 below.

Table 2: Composition of the silicone continuous phase (composition B)

The diphenyl dimethicone (silicone oil) is heated to a temperature of 85 ° C, then the silica (gelling agent) is added gently to the silicone oil. The mixture is then kept under vigorous stirring at a temperature of 85 ° C., until a homogeneous mixture (without grains) is obtained. The two polymers are then added hot, at a temperature of 85 ° C., and the mixture homogenized by stirring. The mixture is then cooled to room temperature until a translucent gel is obtained.

The spheroids of composition A prepared in Example 1 are dispersed in a continuous silicone immiscible phase (composition B), according to a composition A / composition B weight ratio of 40/60, with stirring, at room temperature.

Evaluation of the properties of the lipstick composition:

Gloss test:

The gloss is measured by polarimetric imaging. The test implemented consists in manually spreading a precise quantity of the cosmetic composition (0.15 g) on synthetic skin, Bio Skin Plate, on a surface of 170 χ 30 mm. The

composition is spread out in a strip of homogeneous thickness, to obtain a smooth surface. Three bands are thus prepared. For each measurement, the Bio Skin Plate sample is placed on the cylindrical support of a SAMBA Hair device in order to view the sample. Three gloss measurements are carried out on each strip, in different places.

The gloss values obtained are presented in Table 3 below, the results being expressed in gloss units:

Table 3:

Gloss reference: DIOR ADDICT ULTRA-GLOSS product (Mintel ID: 4228439) Gloss lipstick reference: DIOR ADDICT LIPSTICK product (Mintel ID: 3263269) Satin lipstick reference: ROUGE DIOR INTERNATIONAL product (Mintel ID: 5206147) matte lips: product Dl ORI Fl C (Mintel ID: 4395479)

The composition of the invention has a higher level of gloss than that of reference lipsticks, and even higher than that of a gloss.

Sensory test:

A comparative sensory test between a lipstick according to the invention (anhydrous spheroids of composition A in a continuous silicone phase of composition B) and a long-lasting matte lipstick of reference (MAC MAT LIPSTICK lipstick, Russian Red shade, Mintel ID: 4601379) is then produced on a panel of eight subjects.

The evaluation of the lipsticks is carried out according to various criteria: slippery, shine, comfort, migration and transfer after 3 hours, hold of the shine and the film after 3 hours, according to a rating scale going from 0 (bad) to 4 (excellent).

Table 4:

The lipstick of the invention has a performance level equivalent to the benchmark matte long-wearing lipstick in terms of migration, transfer and holding of the film, while having a higher sliding power, a shine and a shine hold. very superior.

Example 3: Preparation of anhydrous spheroids according to the process of the invention

A composition F comprising the ingredients listed in Table 5 is used to prepare anhydrous spheroids according to two distinct methods: the method of the invention and the method described in application FR 2 649 608.

Table 5: Composition F

Spheroids are prepared according to the process of the invention by following the following steps:

All the ingredients of composition F are heated, mixed and homogenized at 85 ° C, with stirring.

When the mixture is homogeneous, it is poured dropwise into a vase filled with liquid nitrogen at a temperature of -180 ° C, using a nozzle with a diameter of 0.5 mm, with stirring. The droplets solidify immediately on contact with the cryogenic liquid, to form solid spheroids.

The solidified spheroids are then recovered by filtration using a molecular sieve, then dried at room temperature.

Characterization of the spheroids obtained: - Melting point: 72 ° C,

- Average diameter: 2.4 mm.

The spheroids obtained according to the method of the invention are then observed using a binocular magnifier (magnification x20). A photograph of these spheroids is shown in Figure 1. The spheroids obtained are spherical and monodisperse, with a regular diameter (2.4 mm). They also have a smooth surface.

Example 4 (comparative): Preparation of anhydrous spheroids according to the method of application FR 2 649 608

Spheroids are prepared according to the method described in application FR 2 649 68 by following the following steps:

All the ingredients of composition F are heated, mixed and homogenized at 85 ° C., with stirring,

When the mixture is homogeneous, it is dispersed slowly in an aqueous phase heated to the same temperature. Stirring is continued until droplets are obtained.

The mixture is then suddenly cooled by adding an aqueous phase cooled to 0 ° C. Agitation is stopped to avoid damaging the solidified spheroids.

The spheroids are then filtered using a molecular sieve and dried at room temperature.

Characterization of the spheroids obtained: - Melting point: 72 ° C, - Average diameter: 1.3 mm.

The spheroids obtained according to the method of application FR 2 649 608 are then observed using a binocular magnifier (magnification x20). A photograph of these spheroids is shown in Figure 2. The anhydrous spheroids obtained according to this process of the prior art do not have a spherical shape and a monodisperse population as with the process of the invention. It is thus not possible to visually obtain particles which can be used in a cosmetic composition to produce the desired visual effect, namely a population of solid spheroids of spherical and monodisperse shape in a continuous phase.

Claims (20)

1. Process for the preparation of anhydrous spheroids, characterized in that it comprises the following stages: (i) preparation of a cosmetically acceptable lipid matrix comprising: (a) at least one hydrocarbon and / or silicone oil, and optionally an agent gelling agent of said hydrocarbon and / or silicone oil, and / or (b) at least one wax, (ii) cryogenic treatment of the lipid matrix obtained at the end of step (i) to obtain anhydrous spheroids, solid to room temperature, having a diameter of 0.1 to 10 mm. 2. Method according to claim 1 characterized in that the cosmetically acceptable lipid matrix comprises: (a) from 5 to 99.5% by weight of at least one hydrocarbon and / or silicone oil, and optionally a gelling agent for said oil hydrocarbon and / or silicone, and (b) from 0.5 to 95% by weight of at least one wax. 3. Method according to claim 1 or claim 2 characterized in that the cryogenic treatment (ii) is carried out by bringing the lipid matrix obtained at the end of step (i) into contact with a cryogenic gas chosen from l liquid nitrogen, liquid oxygen and liquid air, or with dry ice, or with a mixture chosen from ice / acetone or ice / alcohol mixtures comprising from 1 to 6 carbon atoms. 4. Method according to one of claims 1 to 3 characterized in that the cryogenic treatment (ii) is carried out with a cryogenic gas whose temperature varies from -10 to -200 ° C, preferably at a temperature of -15 to -180 ° C, and even more preferably from -20 to -150 ° C. 5. Method according to one of claims 1 to 4 characterized in that the lipid matrix prepared during step (i) comprises at least one hydrocarbon and / or silicone oil (a) chosen from volatile or non-volatile oils. 6. Method according to one of claims 1 to 5 characterized in that the lipid matrix prepared during step (i) comprises a gelling agent for said hydrocarbon and / or silicone oil (a), said gelling agent being chosen from silicas, clays, optionally modified hectorites, dextrin esters, polyamides or silicone polyamides, amides of L-glutamic acid or of aspartic acid, hydrocarbon block copolymers comprising at least one styrene unit. 7. Method according to one of claims 1 to 6 characterized in that the lipid matrix prepared during step (i) comprises at least one wax (b) chosen from hydrocarbon waxes and / or polyethylene waxes , and preferably from hydrocarbon waxes. 8. Method according to one of claims 1 to 7 characterized in that the lipid matrix obtained at the end of step (i) is made liquid by heating at a temperature ranging from 40 ° C to 110 ° C, preferably from 50 to 100 ° C, and even more preferably from 60 to 90 ° C, prior to the cryogenic treatment step (ii). 9. anhydrous spheroids having a diameter of 0.1 to 10 mm, obtained according to the method of claims 1 to 8, characterized in that they consist of a cosmetically acceptable lipid matrix comprising: (a) at least one hydrocarbon-based oil and / or silicone, and optionally a gelling agent for said hydrocarbon and / or silicone oil, and / or (b) at least one wax, said spheroids having a melting point above 50 ° C. 10. Anhydrous spheroids according to claim 9 characterized in that they consist of a cosmetically acceptable lipid matrix comprising: (a) from 5 to 99.5% by weight of at least one hydrocarbon and / or silicone oil, and optionally a gelling agent for said hydrocarbon and / or silicone oil, and (b) from 0.5 to 95% by weight of at least one wax. 11. Anhydrous spheroids according to claim 9 or claim 10 characterized in that they are free from any external coating. 12. anhydrous spheroids according to one of claims 9 to 11 characterized in that they have a melting point ranging from 50 to 120 ° C, preferably from 60 to 110 ° C, and even more preferably from 70 to 100 ° vs. 13. Use of anhydrous spheroids according to one of claims 9 to 12 in cosmetic compositions for making up and / or caring for the skin of the body or the face, and in particular the lips. 14. Cosmetic makeup and / or care composition characterized in that it comprises anhydrous spheroids according to one of claims 9 to 12 in dispersion in a continuous phase immiscible with said spheroids. 15. Cosmetic composition according to claim 14 characterized in that said spheroids represent from 5 to 70% by weight, preferably from 10 to 60% by weight, and even more preferably from 20 to 50% by weight, relative to the total weight of the cosmetic composition. 16. Lipstick characterized in that it comprises a cosmetic composition according to claim 14 or claim 15. 17. Foundation characterized in that it comprises a cosmetic composition according to claim 14 or claim 15. 18. A method of preparing a cosmetic makeup and / or care composition according to claim 14 or claim 15 characterized in that it comprises a step of dispersing anhydrous spheroids according to one of claims 9 to 12 in a continuous phase immiscible with said spheroids. 19. A method of making up and / or caring for the skin of the body or of the face, and in particular of the lips, characterized in that it comprises the following steps: (i ') removal of an amount of cosmetic composition according to the claims 14 to 17, in an amount necessary to carry out at least one application, (ii ') shear mixing of the anhydrous spheroids according to claims 9 to 12 with the immiscible continuous phase, and (iii') application of the cosmetic composition thus mixed on the skin of the body or of the face, and in particular of the lips. 20. The method of claim 18 characterized in that the shearing mixing step is carried out directly on the skin of the body or face, for example using the fingers, or prior to application to the skin of the body or of the face, within a dispensing device containing said cosmetic composition.