A polymer that takes the form of a powdery solid and has the property of thickening polar media.

Abstract

Disclosed is a polymer (P) in the form of a pulverulent solid, consisting of monomer units derived from partially or completely salified glutamic acid (GA) and at least one crosslinker (XLA) having at least two glycidyl functional groups.

Description

[Technical field]

[0001] The present invention relates to a polymer (P) in the form of a pulverulent solid, to a process for preparing said polymer and to cosmetic compositions containing said polymer. [Background technology]

[0002] Polymers are now widely used in cosmetic formulations for topical use. They are the second most widely used product group in this type of complex formulation. Cosmetic compositions contain polar phases, such as water, and in most cases require the use of rheology modifiers to increase the viscosity of these polar phases and also provide them with distinct rheological behavior.

[0003] Among the polymers that adjust the rheology of the polar phase, mention may be made of natural polymers, such as polysaccharides based on sugars or sugar derivatives, or synthetic polymers of the linear or branched, crosslinked or non-crosslinked, anionic, cationic or amphiphilic polyelectrolyte type. The synthetic polymers that are predominantly present on the market of ingredients intended for cosmetic formulations have the property of being arranged in the polar phase under the influence of electrostatic repulsion due to the presence of negative and / or positive charges on the polymer backbone. These rheology modifiers not only increase the viscosity of the polar phase, but also impart a certain consistency and / or stabilizing effect to the thickened cosmetic, dermatological or dermatological pharmaceutical formulation.

[0004] In order to meet consumer needs and improve the performance of cosmetic formulations, various recent scientific studies have reported the development of new innovative and diverse polymer systems. The polymers used can fulfill various functional roles: - film formers, - rheology modifiers, - agents for stabilising the fatty phase in water-in-oil and oil-in-water emulsions, - agents for stabilizing solid particles (pigments or fillers), - agents imparting specific organoleptic properties (soft feel, ease of ingestion and application, freshness effect, etc.); - Agents which also have a direct effect on the appearance of the formulation (transparent, translucent or opaque).

[0005] The polymers that modify the rheology of the polar phase, and more specifically the aqueous phase, are mainly polyelectrolytes obtained by radical polymerization of (meth)acrylic monomers, i.e. acrylic acid, methacrylic acid, esters derived from acrylic acid or methacrylic acid or acrylamide or methacrylamide derivatives.

[0006] The development of new bio-based and biodegradable rheology modifiers that are as effective as the synthetic polymers currently used remains a major challenge and a key issue for suppliers of cosmetic raw materials. Indeed, the solutions that have been mainly used to thicken the aqueous phase up to now contain ingredients that are derived from raw materials of petrochemical origin, in particular acrylic or methacrylic acid and their derivatives.

[0007] Given the increasing consumer interest in sustainable and responsible economy and development, the replacement of petrochemically derived raw materials with those of natural and renewable origin for the preparation of polymers is a high priority research area.

[0008] To date, the literature describes the use of various natural polymers or polymers from renewable raw materials, whose monomer units are derived from the sugar classes (glucose, arabinose, xylose, galactose, mannose, ribose, glucuronic acid, etc.) or from the amino acid classes (glutamic acid, aspartic acid, lysine, etc.) These polymers are mostly linear or branched, depending on the plant source or the process for their production.

[0009] An example of a naturally occurring polymer is polyglutamic acid (PGA), which is currently the subject of much research. It is a predominantly linear polymer made up of glutamic acid (GA) monomer units. Glutamic acid is an amino acid characterized by an amine functional group at the α-position and two carboxylic acid functional groups (or carboxylate salts, depending on the pH) at the α- and γ-positions (see formula no. 1). [Chemical formula 1] [ka]

[0010] One of the methods to increase the branching of synthetic or natural polymers or polymers of natural origin is to carry out a crosslinking reaction. The purpose of crosslinking polymer chains is to link together several polymer chains which, when added to a polar phase, more specifically to water, appear in the form of a water-insoluble but water-swellable three-dimensional network, which then produces an aqueous gel.

[0011] The preparation of the crosslinked polymer can be carried out in one or two steps according to the following two routes: Route 1: in one step by reacting the monomer with the crosslinker during the polymerization reaction, or - Pathway 2: in at least two steps, the first step consisting of preparing a polymer and the second step consisting of reacting the polymer with a crosslinking agent to obtain a crosslinked polymer.

[0012] There are various reactions for the crosslinking of PGA, which make it possible to obtain polymers of natural origin with improved thickening properties in polar media, especially aqueous media.

[0013] Among the crosslinking agents known to be used in PGA crosslinking reactions, polyepoxide derivatives are the most widely described, since they allow the crosslinking process to be carried out under environmentally friendly conditions (moderate temperatures, reaction in aqueous medium, absence of harmful solvents).

[0014] However, implementing these processes requires high levels of dilution of the PGA, which results in the production of compositions in the form of aqueous gels containing 10% or less by mass of polymer per 100% of its mass, which is difficult for formulators to implement. Summary of the Invention [Problem to be solved by the invention]

[0015] On this basis, the problem that arises is to provide compositions that are easy to formulate, comprising polymers of natural origin whose raw materials are renewable and which have thickening properties for polar media, more particularly aqueous media. [Means for solving the problem]

[0016] One solution of the invention is a polymer (P) in the form of a pulverulent solid, comprising monomer units derived from partially or completely salified glutamic acid (GA) and at least one crosslinker (XLA) having at least two glycidyl functional groups. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] For the purposes of the present invention, the term "pulverulent solid" means a solid consisting of fine particles that are barely or not bonded to one another.

[0018] In the polymer (P) that is the subject of the present invention, the monomer units derived from glutamic acid (GA), partially or completely salified, are linked to one another by: - via a peptide or amide bond involving an amine functional group of a glutamic acid (GA) monomer unit and a carboxylic acid (or carboxylate) functional group located at the alpha (α) position of a second glutamic acid (GA) monomer unit; the corresponding polymer is α-polyglutamic acid or PAGA (see formula number 2), [Chemical formula 2] [ka] - instead, through an amide bond involving an amine functional group of a glutamic acid (GA) monomer unit and a carboxylic acid (or carboxylate) functional group located at the gamma (γ) position of a second glutamic acid (GA) monomer unit; the corresponding polymer is γ-polyglutamic acid or PGGA (see formula number 3). [Chemical formula 3] [ka]

[0019] Typically, PGAs can be prepared chemically according to peptide synthesis methods known to those skilled in the art, in particular through selective protection, activation, coupling and deprotection steps, where coupling generally consists of a nucleophilic attack of an amine function of one glutamic acid monomer unit on an activated carboxylic acid function of another glutamic acid monomer unit.

[0020] PGGA may also be obtained by a process comprising at least one microbial fermentation step involving the use of at least one bacterial strain.

[0021] For the purposes of the present invention, the term "salified" in the polymer (P) defined above means that the "pendant" carboxylic acid functional group present on each glutamic acid (GA) monomer unit of the polymer (at the γ-position in the case of PAGA or the α-position in the case of PGGA) is in anionic or carboxylate form, the counterion of which is a cation derived, for example, from an alkali metal salt such as sodium, potassium, or a salt of a nitrogen-containing base such as an amine, lysine, or monoethanolamine (HO-CH2-CH2-NH2).

[0022] For the purposes of the present invention, the term "crosslinking agent (XLA)" refers to a chemical molecule whose structure allows for the covalent attachment of at least two polymer chains.

[0023] For the purposes of the present invention, the term "crosslinking agent having at least two glycidyl functional groups (XLA)" refers to a crosslinking agent having a molecular structure that contains at least two glycidyl units or a crosslinking agent having the formula (I'): [Chemical formula 3] [ka] By this reference is meant a crosslinker (XLA) as defined above, comprising a functional group:

[0024] The crosslinking of the polymer chains of the polymer (P) is effected by the addition of terminal free amine functional groups (-NH2) and / or one or more "pendant" or terminal carboxylic acids (-COOH) or carboxylates (-COO) present in the structure of said polymer (P). - ) functional group with at least one epoxide group present in the structure of a crosslinker (XLA) having at least two glycidyl functional groups.

[0025] The cross-linking agent (XLA) may be selected from a member of the group consisting of: - Formula (I): - [Chemical formula 4] [ka] monoethylene glycol diglycidyl ether, - Formula (II): [Chemical formula 5] [ka] (In the formula, R is a hydrogen atom or a glycidyl group.) [ka] and n represents an integer of 1 or more and 10 or less. When R represents a hydrogen atom and n is 1, the compound has the formula (IIa): [Chemical formula 6] [ka] where R is a glycidyl group. [ka] and when n is 1, it represents formula (IIb): [Chemical formula 7] [ka] where R represents a hydrogen atom and n is 2, the formula (IIc): [Chemical formula 8] [ka] where R is a glycidyl group. [ka] and when n is 2, it represents formula (IId): [Chemical formula 9] [ka] The compound is a diglyceryl tetraglycidyl ether of - Formula (III): [Chemical formula 10] [ka] 1,3-propanediol diglycidyl ether, - Formula (IV): [Chemical formula 11] [ka] 1,2-propanediol diglycidyl ether, - Formula (V): [Chemical formula 12] [ka] 1,4-butanediol diglycidyl ether, - Formula (VI): [Chemical formula 13] [ka] 1,2-butanediol diglycidyl ether, - Formula (VII): [Chemical formula 14] [ka] 1,3-butanediol diglycidyl ether, - Formula (VIII): [Chemical formula 15] [ka] 1,6-hexanediol diglycidyl ether, - Formula (IX): [Chemical formula 16] [ka] (wherein R1 is a hydrogen atom or a glycidyl group) [ka] (represents When R1 represents a hydrogen atom, the compound has the formula (IXa): [Chemical formula 17] [ka] where R1 is a glycidyl group. [ka] When the formula (IXb): [Chemical formula 18] [ka] The compound is trimethylolethane triglycidyl ether of - Formula (X): [Chemical formula 19] [ka] (wherein R1 is a hydrogen atom or a glycidyl group) [ka] (represents When R1 represents a hydrogen atom, the compound has the formula (Xa): [Chemical formula 20] [ka] where R1 is a glycidyl group. [ka] When the formula (Xb): [Chemical formula 21] [ka] The compound is trimethylolpropane triglycidyl ether of - Formula (XI): [Chemical formula 22] [ka] (wherein R1 and R2 are independent of each other and each represents a hydrogen atom or a glycidyl group.) [ka] (represents When R1 and R2 each represent a hydrogen atom, the compound has the formula (XIa): [Chemical formula 23] [ka] wherein R1 represents a hydrogen atom and R2 represents a glycidyl group. [ka] When the formula (XIb): [Chemical formula 24] [ka] wherein R1 and R2 are each a glycidyl group. [ka] When the formula (XIc): [Chemical formula 25] [ka] The compound is a pentaerythritol tetraglycidyl ether of the formula: - Formula (XII): [Chemical formula 26] [ka] (In the formula, m represents an integer of 2 or more). Polyethylene glycol diglycidyl ether of - Formula (XIII): [Chemical formula 27] [ka] (wherein R3 is a hydrogen atom or a glycidyl group) [ka] and x, y, z, o, p, and q each independently represent an integer of 2 or more and 10 or less. Compound.

[0026] Furthermore, the polymer (P) according to the invention may have one or more of the following characteristics: - the polymer (P) is PGGA in acid form or partially or completely salified, - the crosslinker (XLA) represents 0.5% to 10% by weight per 100% by weight of the monomer units derived from partially or completely salified glutamic acid (GA); the polymer (P) has formula (XIV): [Chemical formula 28] [ka] where R4 represents a linear or branched, saturated or unsaturated hydrocarbon-based group, optionally containing at least one hydroxyl functional group, and containing from 6 to 22 carbon atoms; R4 represents a hydrocarbon-based radical selected from the group consisting of heptyl, octyl, nonyl, decyl, undecyl, undecenyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, hydroxyoctadecyl, oleyl, linoleyl, linolenyl, eicosyl and dodecosyl radicals. Also includes compounds of In said polymer (P), the compound of formula (XIV) accounts for 1% to 50% by weight per 100% by weight of the monomer units derived from partially or completely salified glutamic acid (GA).

[0027] PGGA can exist in various conformational forms in aqueous solution. These forms depend on intermolecular and intramolecular hydrogen bonds, and therefore on the pH, polymer concentration, ionic strength and also temperature of the solution. Thus, PGGA chains can adopt α-helical shapes, β-sheets, aggregates or otherwise disordered and random states.

[0028] According to a particular embodiment, the polymer (P) is in a helical conformation when it is present in a solution at a mass content less than or equal to 0.1% and said solution has a pH value less than or equal to 7.

[0029] According to a particular embodiment, the polymer (P) is in a sheet conformation when it is present in an aqueous solution at a mass content less than or equal to 0.1% and said aqueous solution has a pH value greater than 7.

[0030] According to another particular embodiment, the crosslinking agent (XLA) represents from 0.5% to 8% by weight, and even more particularly from 0.5% to 5% by weight, per 100% of the mass of the monomer units derived from partially or completely salified glutamic acid (GA).

[0031] According to another particular embodiment, R4 representing a hydrocarbon-based group is selected from the members of the group consisting of n-octyl, n-nonyl, n-decyl, n-undecyl, n-undecenyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, 12-hydroxyoctadecyl, n-eicosyl and n-dodecosyl groups.

[0032] A subject of the present invention is a process for preparing a polymer (P) as defined above, comprising: a) preparing a polar phase (PP) comprising a partially or fully salted PGA, at least one polar solvent (PS) and at least one crosslinker (XLA) comprising at least two glycidyl functional groups; b) adjusting the pH of the aqueous solution obtained in step a) to a pH of 3 to 11; and c) drying the polar phase (PP) obtained from step b) by spray drying to obtain a polymer (P) It is also a method that includes the following three steps.

[0033] Optionally, the method according to the invention may have one or more of the following features: In step a), - The polyglutamic acid used is PGGA, - all of the monomer units constituting the PGA are derived from sodium glutamate, potassium glutamate, ammonium glutamate, calcium glutamate, magnesium glutamate or mixtures of these forms; - the polar phase (PP) contains, per 100% of its mass, 5% to 80% by mass of polyglutamic acid (PGA), 0.025% to 8% by mass of a crosslinker (XLA), and 12% to 94.975% by mass of at least one polar solvent; the polar solvent (PS) is selected from the following list: water, methanol, ethanol, 1-propanol, 2-propanol, isobutanol, tert-butanol, 2-methyl-2-propanol, 1-butanol, 2-butanol, acetone, dimethyl ketone, diethyl ketone, tetrahydropyran, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane and 1,4-dioxane; the polar phase (PP) has the formula (XIV): [Chemical formula 29] [ka] where R4 represents a linear or branched, saturated or unsaturated hydrocarbon-based group, optionally containing at least one hydroxyl functional group, and containing from 6 to 22 carbon atoms; R4 represents a hydrocarbon-based radical selected from the group consisting of heptyl, octyl, nonyl, decyl, undecyl, undecenyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, hydroxyoctadecyl, oleyl, linoleyl, linolenyl, eicosyl and dodecosyl radicals. and also comprising at least one compound of - the content of the compound of formula (XIV) in the polar phase (PP) is 0.05% by weight to 35% by weight per 100% by weight of said polar phase (PP), it being understood that the sum of the mass proportions of polyglutamic acid (PGA), crosslinker (XLA), polar solvent (PS) and compound of formula (XIV) is equal to 100%. In step b), The pH is between 4 and 10, preferably between 5 and 7. In step c), - drying is carried out with a sprayer using an air stream and a nozzle; The inlet temperature of the air stream is between 80 and 180°C, preferably between 100 and 170°C.

[0034] According to a particular embodiment, the polar phase (PP) comprises, per 100% of its mass, 5% to 70% by weight of a polymer (P) polyglutamic acid (PGA), 0.025% to 7% by weight of a crosslinker (XLA), and 23% to 94.975% by weight of at least one polar solvent (PS).

[0035] According to an even more specific embodiment, the polar phase (PP) comprises, per 100% of its mass, 5% to 60% by mass of the polymer (P) polyglutamic acid (PGA), 0.025% to 6% by mass of the crosslinker (XLA), and 34% to 94.975% by mass of at least one polar solvent (PS).

[0036] According to another particular embodiment, the polar solvent (PS) is selected from the list: water, ethanol, acetone, dimethyl ketone.

[0037] According to another more particular embodiment, the polar solvent (PS) is water.

[0038] According to another particular embodiment, R4 representing a hydrocarbon-based group is selected from the members of the group consisting of n-octyl, n-nonyl, n-decyl, n-undecyl, n-undecenyl, n-dodecyl, n-tetradecyl, n-hexadecyl, n-octadecyl, 12-hydroxyoctadecyl, n-eicosyl and n-dodecosyl groups.

[0039] According to another particular embodiment, the content of the compound of formula (XIV) in the polar phase (PP) is between 0.05% and 20% by weight, and even more particularly between 0.05% and 15% by weight, per 100% by weight of said polar phase (PP), it being understood that the sum of the mass proportions of polyglutamic acid (PGA), crosslinker (XLA), polar solvent (PS) and compound of formula (XIV) is equal to 100%.

[0040] Finally, the present invention also relates to a cosmetic composition (F) for topical use comprising, per 100% of its total mass, from 0.05% to 10% by weight, more preferably from 0.1% to 5% by weight, and even more specifically from 0.1% to 3% by weight, of at least one polymer (P) as defined above.

[0041] The term "topical" as used in the definition of composition (F) means that it is used by applying to the skin, hair, scalp or mucous membranes, whether this is a direct application, as in the case of cosmetics or dermatological cosmetics, or an indirect application, as in the case of body care products, for example in the form of textile or paper wipes, or hygiene products intended to come into contact with the skin or mucous membranes.

[0042] Said composition (F) is generally in the form of an aqueous, or aqueous-alcoholic, or aqueous-glycolic solution, a suspension, an emulsion, a microemulsion or a nanoemulsion, which may be of the water-in-oil, oil-in-water, water-in-oil-in-water or oil-in-water-in-oil type.

[0043] Said composition (F) as defined above can be contained in a bottle, in a pump bottle type device, in a pressurized form in an aerosol device, in a device with an openwork wall, such as a grate, or in a device with a ball applicator (known as a roll-on).

[0044] Generally, said composition (F) also contains pharmaceutical additives and / or active ingredients customary in formulations for topical use, in particular in the field of cosmetics or dermatological cosmetics: for example thickening and / or gelling surfactants, stabilizers, film-forming compounds, hydrotropes, plasticizers, emulsifiers and coemulsifiers, opacifiers, pearlescent agents, superfatting agents, sequestering agents, chelating agents, antioxidants, fragrances, preservatives, conditioning agents, bleaching agents intended for bleaching hair and skin, active ingredients intended for providing a treatment action on the skin or hair, sunscreens, pigments or mineral fillers, particles intended for providing a visual effect or for encapsulating active ingredients, exfoliant particles or texturizing agents.

[0045] Examples of foaming and / or cleansing surfactants which can be combined with the polymer (P) in said composition (F) defined above include anionic, cationic, amphoteric or nonionic foaming and / or cleansing surfactants.

[0046] Examples of anionic foaming and / or cleaning surfactants which may be combined with the polymer (P) in said composition (F) as defined above include the alkali metal, alkaline earth metal, ammonium, amine or amino alcohol salts of: alkyl ether sulfates, alkyl ether sulfates, alkyl sulfates, alkyl amido ether sulfates, alkyl aryl polyether sulfates, monoglyceride sulfates, α-olefin sulfonates, paraffin sulfonates, alkyl phosphates, alkyl ether phosphates, alkyl sulfonates, alkyl amido sulfonates, alkyl aryl sulfonates, alkyl carboxylates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkyl amido sulfosuccinates, alkyl sulfoacetates, alkyl sarcosinates, acyl isethionates, N-acyltaurates, acyl lactylates, N-acyl amino acid derivatives, N-acyl peptide derivatives, N-acyl protein derivatives, N-acyl fatty acid derivatives.

[0047] Examples of foaming and / or cleansing amphoteric surfactants which may be combined with the polymer (P) in said composition (F) defined above include: alkylbetaines, alkylamidobetaines, sultaines, alkylamidoalkylsulfobetaines, imidazoline derivatives, phosphobetaines, amphopolyacetates and amphopropionates.

[0048] As examples of cationic foaming and / or cleaning surfactants which may be combined with the polymer (P) in said composition (F) defined above, mention may in particular be made of quaternary ammonium derivatives.

[0049] Examples of nonionic foaming and / or cleaning surfactants which may be combined with the polymer (P) in said composition (F) defined above include: alkyl polyglycosides, more particularly containing a linear or branched, saturated or unsaturated aliphatic group and containing from 8 to 16 carbon atoms, such as octylpolyglucoside, decylpolyglucoside, undecylenylpolyglucoside, dodecylglucoside, tetradecylpolyglucoside, hexadecylpolyglucoside, 1,12-dodecanediylpolyglucoside; ethoxylated hydrogenated castor oil derivatives, such as the product sold under the INCI name PEG-40 hydrogenated castor oil; polysorbates, such as polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 70, polysorbate 80 and polysorbate 85; coconut kernel amides; N-alkylamines.

[0050] Examples of thickening and / or gelling surfactants which may be combined with the polymer (P) in said composition (F) defined above include: fatty acid esters of alkyl polyglycosides, optionally alkoxylated, such as ethoxylated methyl polyglucoside esters, such as PEG 120 methyl glucose trioleate and PEG 120 methyl glucose dioleate (sold under the names Glutamate® LT and Glutamate® DOE 120, respectively); alkoxylated Fatty acid esters, such as PEG 150 pentaerythrityl tetrastearate (sold under the name Crothix® DS53), PEG 55 propylene glycol oleate (sold under the name Antil® 141); aliphatic chain polyalkylene glycol carbamates, such as PPG-14 laureth isofloryl dicarbamate (sold under the name Elfacos® T211), PPG-14 palmetto-60 hexyl dicarbamate (sold under the name Elfacos® GT2125).

[0051] As examples of thickening and / or gelling agents that can be combined with the polymer (P) in said composition (F) defined above, mention may be made of the following: a copolymer of AMPS and an alkyl acrylate whose carbon chain contains from 4 to 30 carbon atoms, more particularly from 10 to 30 carbon atoms, at least one monomer having a strong acid function in free form, partially or completely salted, at least one neutral monomer and a compound of formula (XXX): CH2=C(R'3)-C(=O)-[CH2-CH2-O]n'-R'4(XXX) (In the formula, R'3 represents a hydrogen atom or a methyl group, R'4 represents a linear or branched alkyl group containing 8 to 30 carbon atoms, and n' represents a number of 1 or more and 50 or less.) Linear, branched or crosslinked terpolymers with at least one monomer of

[0052] Examples of thickening and / or gelling agents which may be combined with the polymer (P) in said composition (F) defined above include: polysaccharides consisting only of monosaccharides, such as glucans or homopolymers of glucose, glucomanoglucans, xyloglycans, galactomannans whose degree of substitution (DS) of D-galactose units on their D-mannose backbone is between 0 and 1, more particularly between 1 and 0.25, such as those derived from cassia gum (DS=1 / 5), locust bean gum (DS=1 / 4), tara gum (DS=1 / 3), guar gum (DS=1 / 2) or fenugreek gum (DS=1).

[0053] Examples of thickening and / or gelling agents which may be combined with the polymer (P) in said composition (F) as defined above include: polysaccharides consisting of monosaccharide derivatives, such as sulfated galactans, more particularly carrageenans and agar-agar, uronans, more particularly algins, alginates and pectins, heteropolymers of monosaccharides and uronic acids and more particularly xanthan gum, gellan gum, gum arabic and karaya exudates or glycosaminoglycans.

[0054] Examples of thickening and / or gelling agents which may be combined with the polymer (P) in said composition (F) defined above include: cellulose, cellulose derivatives such as methylcellulose, ethylcellulose, hydroxypropylcellulose, silicates, starch, hydrophilic starch derivatives or polyurethanes.

[0055] As examples of stabilizers which may be combined with the polymer (P) in said composition (F) defined above, mention may be made of: monocrystalline waxes, more particularly ozokerite, inorganic salts such as sodium chloride or magnesium chloride, as well as silicone polymers, such as polysiloxane polyalkyl polyether copolymers.

[0056] Examples of solvents which may be combined with the polymer (P) in said composition (F) defined above include: water, organic solvents such as glycerol, diglycerol, glycerol oligomers, ethylene glycol, propylene glycol, butylene glycol, 1,3-propanediol, 1,2-propanediol, hexylene glycol, diethylene glycol, xylitol, erythritol, sorbitol, water-soluble alcohols such as ethanol, isopropanol or butanol, or mixtures of water with said organic solvents.

[0057] As examples of thermal or mineral waters which can be combined with the polymer (P) in the composition (F) defined above, mention may be made of: thermal or mineral waters having a mineralization of at least 300 mg / l, in particular Avene water, Vittel water, Vichy basin water, Uriage water, La Roche-Posay water, La Bourboule water, Enghien-les-bains water, Saint-Gervais-les-bains water, Neris-les-bains water, Allevard-les-bains water, Digne water, Maizieres water, Neyrac-les-bains water, Lons-le-Saunier water, Rochefort water, Saint Christau water, Les Fumades water and Tercis-les-Bains water.

[0058] As examples of hydrotropic agents which may be combined with the polymer (P) in said composition (F) defined above, mention may be made of: xylene sulfonate, cumene sulfonate, hexyl polyglucoside, 2-ethylhexyl polyglucoside or n-heptyl polyglucoside.

[0059] As examples of emulsifying surfactants which can be combined with the polymer (P) in said composition (F) defined above, mention may be made of: nonionic surfactants, anionic surfactants or cationic surfactants.

[0060] Examples of emulsifying nonionic surfactants which can be combined with the polymer (P) in said composition (F) defined above include: fatty acid esters of sorbitol, such as the products sold under the names Montane® 40, Montane® 60, Montane® 70, Montane® 80 and Montane® 85; compositions comprising glyceryl stearate and stearic acid ethoxylated with 5 to 150 moles of ethylene oxide, such as a composition comprising stearic acid ethoxylated with 135 moles of ethylene oxide and glyceryl stearate (sold under the name Simulsol® 165); mannitan esters, ethoxylated mannitan esters; sucrose esters; methyl glucoside esters; fatty acids containing linear or branched, saturated or unsaturated aliphatic groups. alkyl polyglycosides containing 14 to 36 carbon atoms, such as tetradecyl polyglucoside, hexyldecyl polyglucoside, octadecyl polyglucoside, hexadecyl polyxyloside, octadecyl polyxyloside, eicosyl polyglucoside, dodecyl polyglucoside, 2-octyldodecyl polyxyloside, 12-hydroxystearyl polyglucoside; compositions of linear or branched, saturated or unsaturated fatty alcohols containing 14 to 36 carbon atoms and the above-mentioned alkyl polyglycosides, such as those sold under the names Montanov™ 68, Montanov™ 14, Montanov™ 82, Montanov™ 202, Montanov™ S, Montanov™ WO18, Montanov™ L, Fluidanov™ 20X and Easynov™.

[0061] Examples of anionic surfactants which can be combined with the polymer (P) in said composition (F) defined above include: glyceryl stearate citrate, cetearyl sulfate, soaps such as sodium stearate or triethanolammonium stearate or N-acyl derivatives of amino acids in salified form, such as stearoyl glutamate.

[0062] As examples of emulsifying cationic surfactants which can be combined with the polymer (P) in the composition (F) defined above, mention may be made of: amine oxides, Quaternium-82 and the surfactants described in patent application WO 96 / 00719, mainly those whose aliphatic chain contains at least 16 carbon atoms.

[0063] As examples of opacifying and / or pearlescent agents which may be combined with the polymer (P) in said composition (F) defined above, mention may be made of: sodium palmitate, sodium stearate, sodium hydroxystearate, magnesium palmitate, magnesium stearate, magnesium hydroxystearate, ethylene glycol monostearate, ethylene glycol distearate, polyethylene glycol monostearate, polyethylene glycol distearate and fatty alcohols containing from 12 to 22 carbon atoms.

[0064] Examples of texturizing agents which may be combined with the polymer (P) in said composition (F) defined above include: N-acylamino acid derivatives, such as lauroyl lysine (sold under the name Aminohope™ LL), octenyl starch succinate (sold under the name Dryflo™), myristyl polyglucoside (sold under the name Montanov™ 14), cellulose fibres, cotton fibres, chitosan fibres, talc, sericite and mica.

[0065] Examples of deodorising agents which may be combined with the polymer (P) in said composition (F) as defined above include: alkali metal silicates, zinc salts, such as zinc sulfate, zinc gluconate, zinc chloride or zinc lactate; quaternary ammonium salts, such as cetyltrimethylammonium salts or cetylpyridinium salts; glycerol derivatives, such as glyceryl caprate, glyceryl caprylate or polyglyceryl caprate; 1,2-decanediol, 1,3-propanediol; salicylic acid; sodium bicarbonate; cyclodextrins; metal zeolites; Triclosan®; aluminium bromohydrate, aluminium chlorohydrate, aluminium chloride, aluminium sulphate, aluminium zirconium chlorohydrate, Aluminum zirconium trichlorohydrate, aluminum zirconium tetrachlorohydrate, aluminum zirconium pentachlorohydrate, aluminum zirconium octachlorohydrate, aluminum sulfate, aluminum sodium lactate or a complex of aluminum chlorohydrate with glycol, for example a complex of aluminum chlorohydrate with propylene glycol, a complex of aluminum dichlorohydrate with propylene glycol, a complex of aluminum sesquichlorohydrate with propylene glycol, a complex of aluminum chlorohydrate with polyethylene glycol, a complex of aluminum dichlorohydrate with polyethylene glycol or a complex of aluminum sesquichlorohydrate with polyethylene glycol.

[0066] Examples of oils that may be combined with the polymer (P) in said composition (F) as defined above include mineral oils, such as liquid paraffin, liquid petroleum jelly, isoparaffin or white mineral oil; oils of animal origin, such as squalene or squalane; vegetable oils, such as phytosqualane, sweet almond oil, palm kernel oil, castor oil, jojoba oil, olive oil, rapeseed oil, peanut oil, sunflower oil, malt oil, corn germ oil, soybean oil, cotton oil, alfalfa oil, poppy seed oil, carrot oil, thyme ... Tea oil, evening primrose oil, millet oil, barley oil, rye oil, safflower oil, kukui oil, passionflower oil, hazel oil, palm oil, shea butter, apricot kernel oil, beauty leaf oil, sisymbrium oil, avocado oil, calendula oil, oils of flower or vegetable origin, ethoxylated vegetable oils; synthetic oils, for example fatty acid esters, for example butyl myristate, propyl myristate, isopropyl myristate, cetyl myristate, isopropyl palmitate, octyl palmitate, butyl stearate, stearyl hexadecyl stearate, isopropyl stearate, octyl stearate, isocetyl stearate, dodecyl oleate, hexyl laurate, propylene glycol dicaprylate, esters derived from lanolic acid such as isopropyl lanolate, isocetyl lanolate, mono-, di- and triglycerides of fatty acids such as glyceryl triheptanoate, alkyl benzoates, hydrogenated oils, poly(α-olefins), polyolefins such as poly(isobutane), synthetic isoalkanes such as isohexadecane, isododecane, perfluorinated oils; silicone oils such as dimethylpolysiloxane, methylphenylpolysiloxane, silicones modified with amines, silicones modified with fatty acids, silicones modified with alcohols, silicones modified with alcohols and fatty acids, silicones modified with polyether groups, epoxy modified silicones, silicones modified with fluoro groups, cyclic silicones and silicones modified with alkyl groups. In this patent application, the term "oil" refers to a compound and / or mixture of compounds that is insoluble in water and has the appearance of a liquid at a temperature of 25°C.

[0067] Examples of waxes that can be combined with the polymer (P) in said composition (F) defined above include: beeswax, carnauba wax, candelilla wax, ourica wax, Japan wax, cork fiber wax, sugarcane wax, paraffin wax, lignite wax, microcrystalline wax, lanolin wax; ozokerite; polyethylene wax; silicone wax; vegetable waxes; fatty alcohols and fatty acids that are solid at room temperature; glycerides that are solid at room temperature. In this patent application, the term "wax" refers to compounds and / or mixtures of compounds that are insoluble in water and have a solid appearance at temperatures above 45°C.

[0068] Examples of active ingredients which can be combined with the polymer (P) in said composition (F) as defined above include: vitamins and their derivatives, in particular their esters, such as retinol (vitamin A) and its esters (for example retinyl palmitate), ascorbic acid (vitamin C) and its esters, saccharide derivatives of ascorbic acid (for example ascorbyl glucoside), tocopherol (vitamin E) and its esters (for example tocopherol acetate), vitamins B3 or B10 (vitamin B10), vitamins B2 and B3 (vitamin B2), vitamins B10 and B2 (vitamin B3), vitamins B10 and B2 (vitamin B4), vitamins B2 and B3 (vitamin B5), vitamins B3 and B10 (vitamin B6), vitamins B4 and B10 (vitamin B7), vitamins B5 and B10 (vitamin B8), vitamins B6 and B10 (vitamin B9), vitamins B7 and B10 (vitamin B10), vitamins B8 and B10 (vitamin B10), vitamins B9 and B10 (vitamin B10), vitamins B10 and B20 (vitamin B10), vitamins B10 and B20 (vitamin B2), vitamins B10 and B10 (vitamin B3), vitamins B10 and B10 (vitamin B4), vitamins B10 and B20 (vitamin B5), vitamins B10 and B10 (vitamin B6), vitamins B10 and B20 (vitamin B1), vitamins B20 and B20 (vitamin B2), vitamins B3 and B10 (vitamin B3), vitamins B4 and B10 (vitamin B4), vitamins B5 and B10 (vitamin B5), vitamins B6 and B10 (vitamin B6), vitamins B7 and B10 (vitamin B7 iacinamide and its derivatives; compounds having a lightening or depigmenting effect on the skin, such as ω-undecylenoylphenylalanine (sold under the names Sepiwhite® MSH, Sepicalm® VG), glycerol monoesters and / or diesters of ω-undecylenoylphenylalanine, ω-undecylenoyl dipeptide, arbutin, kojic acid, hydroquinone; compounds having a soothing effect, in particular Sepicalm® S, allantoin and bisabolol; anti-inflammatory agents; compounds having a moisturizing effect. compounds such as urea, hydroxyurea, glycerol, polyglycerol, glycerol glucoside, diglycerol glucoside, polyglyceryl glucoside, xylityl glucoside; polyphenol-rich plant extracts such as grape extract, pine extract, wine extract or olive extract; slimming or lipolytic compounds such as caffeine or its derivatives, Adiposlim™, Adipoless™, fucoxanthin; N-acyl proteins; N-acyl peptides such as Matrixy l(trademark);N-acyl amino acids;N-acyl partial protein hydrolysates;amino acids;peptides;total protein hydrolysates;soy extracts, e.g. Raffermine(trademark);wheat extracts, e.g. Tensine(trademark) or Gliadine(trademark);plant extracts, e.g. tannin-rich plant extracts, isoflavone-rich plant extracts or terpene-rich plant extracts;freshwater or saltwater algae extracts;marine plant extracts;marine extracts in general, such as coral;refined waxes;bacterial extracts;ceramides;phospholipids;Compounds exhibiting antibacterial or cleansing action, such as Lipacide® C8G, Lipacide® UG, Sepicontrol® A5, Octotropirox® or Sensiva® SC50; compounds exhibiting energizing or stimulating properties, such as Physiogenyl®, panthenol and its derivatives, such as Sepicap® MP; anti-ageing active agents, such as Sepilift® DPHP, Lipacide® PVB, Sepivinol®, Sepivital®, Manoliva®, Phyto-Age®, Timecode®; Survic ode™;anti-photoaging active agents;agents for protecting the integrity of the epidermal-dermal junction;agents promoting the synthesis of components of the extracellular matrix, such as collagen, elastin or glycosaminoglycans;active agents with a promoting effect on chemical cell communication, such as cytokines, or active agents with a promoting effect on physical cell communication, such as integrins;active agents for producing a "warm" sensation on the skin, such as cutaneous microcirculation activators (for example nicotinic acid derivatives) or products for producing a "cool" sensation on the skin (for example menthol and its derivatives);active agents for improving cutaneous microcirculation, such as venous activators;pus drainage active agents;active agents for relieving congestion, such as extracts of Ginkgo biloba, ivy, horse chestnut, bamboo, Ruscus, butcher's-broom, Centella asiatica, fucus, rosemary or willow;Agents for tanning or browning the skin, such as dihydroxyacetone (DHA), erythrulose, mesotartaric aldehyde, glutaraldehyde, glyceraldehyde, alloxan or ninhydrin, plant extracts, such as the red wood of the genera Pterocarpus and Baphia, for example extracts of Pterocarpus santalinus, Pterocarpus osun, Pterocarpus soyauxii, Pterocarpus erinaceus, Pterocarpus indicus or Baphia nitida, for example those described in European Patent Application Publication No. 0 971 683; agents known for their action of facilitating and / or accelerating the tanning and / or browning of human skin and / or for their action in pigmenting human skin, such as carotenoids (more particularly β-carotene and γ-carotene), the product sold by the company Provital under the brand name Carrot Oil (INCI name: Daucus carrota, Helianthus annuus sunflower oil), which contains carotenoids, vitamin E and vitamin K;Tyrosine and / or its derivatives, known for their effect in accelerating the tanning of human skin in combination with UV exposure, such as the product sold under the brand name SunTan Accelerator™ by the company Provital, which contains tyrosine and riboflavin (vitamin B), tyrosine and tyrosinase complex sold under the brand name Zymo Tan Complex by the company Zymo Line, the product sold under the brand name MelanoBronze™ by the company Mibelle (INCI name: Acetyl Tyrosine, Italian carrot bark extract (Vitex agnus-castus)), which contains acetyl tyrosine, Unipertan by the company Unipex, Products sold under the brand name VEG-24 / 242 / 2002 (INCI Name: Butylene Glycol and Acetyl Tyrosine and Hydrolyzed Vegetable Proteins and Adenosine Triphosphate), products sold under the brand name Try-Excell™ by Sederma (INCI Name: Oleoyl Tyrosine and Luffa cylindrica (Seed) Oil and Oleic Acid) (which contains an extract of mallow seeds (or loofah oil)), Alban products sold under the brand name Actibronze™ by the company Muller (INCI Name: Hydrolyzed Wheat Protein, Acetyl Tyrosine and Copper Gluconate), products sold under the brand name Tyrostan™ by the company Synerga (INCI Name: Potassium Caproyl Tyrosine), products sold under the brand name Tyrosinol by the company Synerga (INCI Name: Sorbitan Isostearate, Glyceryl Oleate, Caproyl Tyrosine), products sold under the brand name InstaBronze™ by the company Alban Muller (INCI Name: Dihydroxyacetone, Acetyl Tyrosine and Copper Gluconate), products sold under the brand name Tyrosilane by the company Exymol (INCI Name: Methylsilanol and Acetyl Tyrosine);Peptides known for their effect in activating melanogenesis, such as the product sold under the brand name Bronzing SF Peptide Powder by the company Infinitec Activos (INCI Name: Dextran and Octapeptide-5), the product sold under the brand name Melitane (INCI Name: Glycerin and Water and Dextran and Acetyl Hexapeptide-1) (containing Acetyl Hexapeptide-1, known for its α-MSH antagonistic activity), the product sold under the brand name Melatimes Solutions™ by the company Lipotec (INCI Name: Butylene Glycol, Palmitoyl Tripeptide-40), sugars and sugar derivatives, such as the product sold under the brand name Tanositol™ by the company Provital (INCI Name: Inositol), the product sold under the brand name Thalitan™ (or Phycosaccharide™ AG) by the company CODIF International (INCI Name: Water and Hydrolyzed Algin (Laminaria digitata) digitata) and magnesium and manganese sulfates) (containing marine-derived oligosaccharides (guluronic and mannuronic acids chelated with magnesium and manganese ions)), products sold under the brand name Melactiva™ by Alban Muller (INCI name: Maltodextrin, Mucuna pruriens seed extract), flavonoid-rich compounds such as products sold under the brand name Biotanning by Silab (INCI name: Hydrolyzed Citrus Aurantium dulcis fruit extract) and those known to be rich in lemon flavonoids (of the hesperidin type);agents intended for treating scalp and / or body hair, for example agents for protecting melanocytes of hair follicles, selected from those described in EP 1 515 688 A2, such as for example mimicking the tautomerase activity of DOPAchrome, intended to protect said melanocytes against cytotoxic agents that cause senescence and / or apoptosis of said melanocytes, such as synthetic SOD mimetic molecules, for example manganese complexes, antioxidant compounds, for example cyclodextrin derivatives, ascorbic acid, silica-containing compounds derived from lysine or arginine pyrrolidone carboxylate, combinations of mono- and diesters of cinnamic acid and vitamin C, and more generally those described in EP 1 515 688 A2;

[0069] Examples of antioxidants that may be combined with the polymer (P) in said composition (F) defined above include: EDTA and its salts, citric acid, tartaric acid, oxalic acid, BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), tocopherol derivatives such as tocopherol acetate, mixtures of antioxidant compounds such as Dissolvine™ GL47S (INCI name: tetrasodium glutamate diacetate) sold by AkzoNobel.

[0070] Examples of sunscreens which may be combined with the polymer (P) in the composition (F) defined above include: all those listed in Annex VII of the Cosmetics Regulation 76 / 768 / EEC, as amended.

[0071] Among the organic sunscreens which may be combined with the polymer (P) in said composition (F) defined above, mention may be made of: the family of benzoic acid derivatives, such as para-aminobenzoic acid (PABA), in particular the monoglyceryl esters of PABA, the ethyl ester of N,N-propoxy PABA, the ethyl ester of N,N-diethoxy PABA, the ethyl ester of N,N-dimethyl PABA, the methyl ester of N,N-dimethyl PABA and the butyl ester of N,N-dimethyl PABA; the family of anthranilic acid derivatives, such as the family of salicylic acid derivatives, such as amyl salicylate, homomenthyl salicylate, ethylhexyl salicylate, phenyl salicylate, benzyl salicylate and p-isopropanolphenyl salicylate; the family of cinnamic acid derivatives, such as ethylhexyl cinnamate, ethyl-4-isopropyl cinnamate, methyl 2,5-diisopropyl cinnamate, p-methoxypropyl cinnamate, p-methoxyisopropyl cinnamate, p-methoxyisoamyl cinnamate, p-methoxyoctyl cinnamate (p-methyl cinnamate); p-methoxy-2-ethylhexyl), p-methoxy-2-ethoxyethyl, p-methoxycyclohexyl cinnamate, ethyl-α-cyano-β-phenyl cinnamate, 2-ethylhexyl-α-cyano-β-phenyl cinnamate or glyceryl cinnamate, di-para-methoxymono-2-ethylhexanoyl cinnamate; the family of benzophenone derivatives, such as 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-Hydroxy-4-methoxy-4'-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, 2-ethylhexyl-4'-phenylbenzophenone-2-5-carboxylate, 2-hydroxy-4-n-octyloxybenzophenone, 4-hydroxy-3-carboxybenzophenone;3-(4'-methylbenzylidene)-d,l-camphor, 3-(benzylidene)-d,l-camphor, camphor benzalkonium methosulfate;Urocanic acid, ethyl urocanate;the family of sulfonic acid derivatives, such as 2-phenylbenzimidazole-5-sulfonic acid and its salts; the family of triazine derivatives, such as hydroxyphenyltriazine, ethylhexyloxyhydroxyphenyl-4-methoxyphenyltriazine, 2,4,6-trianilino(p-carbo-2'-ethylhexyl-1'-oxy)-1,3,5-triazine, 4,4-((6-(((1,1-dimethylethyl)amino)carbonyl)phenyl)amino)-1,3,5-triazine-2,4-diyldiimino)bis(2-ethylhexyl)benzoate, 2-phenyl-5-methylbenzoxazole, 2,2'-hydroxyphenyl-4-methoxyphenyltriazine, 5-methylphenylbenzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, 2-(2'-hydroxy-5'-methyphenyl)benzotriazole; dibenzadine; dianisoylmethane, 4-methoxy-4''-t-butylbenzoylmethane; 5-(3,3-dimethyl-2-norbornylidene)-3-pentan-2-one; the family of diphenylacrylate derivatives, such as 2-ethylhexyl 2-cyano-3,3-diphenyl-2-propenoate, ethyl 2-cyano-3,3-diphenyl-2-propenoate; the family of polysiloxanes, such as benzylidene siloxane malonate.;

[0072] Mineral sunscreens (also called "mineral sunblocks") that can be combined with the polymer (P) in the composition (F) defined above can include: titanium oxide, zinc oxide, cerium oxide, zirconium oxide, yellow, red or black iron oxide and chromium oxide. These mineral sunblocks may be micronized or not, may be surface-treated or not, and may optionally be in the form of an aqueous or oily predispersion. EXAMPLES

[0073] The following examples illustrate the invention without, however, limiting it.

[0074] Example 1: Preparation of sodium PGGA according to the present invention crosslinked with polyethylene glycol diglycidyl ether and sprayed: The synthesis process involves four steps: Step 1): Preparation of aqueous sodium PGGA gel: 200 grams of demineralized water are stirred with a Rayneri™ brand mechanical stirrer equipped with a deflocculating rotor, and then 20 grams of PGGA sold by Lubon under the name Cosmetic Grade PGGA are slowly added to the vortex. Step 2): Adjust pH: Adjust the pH of the mixture from step 1) to a value of 5.5-6.0 using 5 M aqueous HCl solution (temperature = 20 °C). Step 3): Add crosslinker: Add 1.2 grams of polyethylene glycol diglycidyl ether (PEGDGE) having an average molecular weight of about 500 g / mol to the mixture of step 2). Step 4): Spraying: The aqueous solution obtained in step 3) is concentrated by passing it through an atomizer. The operating parameters are as follows: - Solution introduction rate = 4ml / min, - spray nozzle pressure=1.5bar, - Circulating air temperature = 150°C.

[0075] Composition (E1) is finally isolated in powder form.

[0076] Example 2: Preparation of sodium PGGA according to the present invention crosslinked with 1,4-butanediol diglycidyl ether and sprayed: The synthesis process of Example 1 is reproduced, replacing 1.2 grams of polyethylene glycol diglycidyl ether (PEGDGE) with 0.48 grams of 1,4-butanediol diglycidyl ether sold under the name Erisys™ GE21 by the company Emerald.

[0077] The resulting composition (E2) is finally isolated in powder form.

[0078] Evaluation of the crosslinked and sprayed sodium PGGA obtained in the two previous examples: The evaluation of the compositions (E1) and (E2) (crosslinked and sprayed sodium PGGA) obtained in the two previous examples was carried out as follows: - Dispersing 4 g of the composition to be tested in 196 g of water in a 400 ml high-sided beaker while stirring using a Rayneri™ brand mechanical stirrer equipped with a deflocculating rotor until a homogenous gel is obtained; - Measure the kinematic viscosity using a Brookfield RVT Viscometer, speed 5, selecting the appropriate spindle, - adding 0.1% NaCl to the previously obtained gel and stirring with a Rayneri™ brand mechanical stirrer equipped with a deflocculating rotor until the mixture is homogenous; - Using the same viscometer as before, but again selecting the appropriate spindle, measure the kinematic viscosity.

[0079] A control was made from non-crosslinked PGGA sold by Lubon under the name Cosmetic Grade PGGA.

[0080] The measured kinematic viscosity values ​​are summarized in the table below.

[0081] [Table 1]

[0082] Dynamic viscosity of aqueous gels obtained using compositions (E1) and (E2). The control sodium PGGA gel (uncrosslinked and unsprayed) has a viscosity of 100-200 mPa.s in the presence or absence of NaCl.

[0083] In the absence of NaCl, the crosslinked sprayed sodium PGGA gels have viscosities of 30,400 mPa.s when the crosslinker is PEGDGE and 41,520 mPa.s when Erisys™ GE 21 is used as the crosslinker, respectively.

[0084] In the presence of NaCl, the viscosity of the sprayed sodium PGGA gel crosslinked with PEGDGE is 9320 mPa.s.

[0085] Compositions (E1) and (E2) according to the invention therefore make it possible to thicken the aqueous phase.

Claims

1. A process for preparing a polymer (P) in the form of a pulverulent solid, comprising monomer units derived from glutamic acid (GA) partially or completely salified and at least one crosslinker (XLA) having at least two glycidyl functional groups, comprising the steps of: Step a) a partially or fully salified polyglutamic acid (PGA) and at least one polar solvent (PS), - Formula (I): [Formula 1] monoethylene glycol diglycidyl ether, - Formula (II): [Case 2] (wherein R is a hydrogen atom or a glycidyl group) [C3] and n represents an integer of 1 or more and 10 or less. Compounds of - Formula (III): [C4] 1,3-propanediol diglycidyl ether, - Formula (IV): [C5] 1,2-propanediol diglycidyl ether, - Formula (V): [C6] 1,4-butanediol diglycidyl ether of Formula (VI): [C7] 1,2-butanediol diglycidyl ether of - Formula (VII): [C8] 1,3-butanediol diglycidyl ether of - Formula (VIII): [C9] 1,6-hexanediol diglycidyl ether, - Formula (IX): [C10] (wherein R1 is a hydrogen atom or a glycidyl group) [C11] (represents Compounds of - Formula (X): [C12] (wherein R1 is a hydrogen atom or a glycidyl group) [C13] (represents Compounds of - Formula (XI): [C14] (Wherein, R1 and R2 are independent and each represents a hydrogen atom or a glycidyl group. [C15] (represents Compounds of Formula (XII): [C16] (In the formula, m represents an integer of 2 or more). Compounds of Formula (XIII): [C17] (Wherein, R3 is a hydrogen atom or a glycidyl group. [C18] and x, y, z, o, p, and q each independently represent an integer of 2 or more and 10 or less. Compound and at least one crosslinker (XLA) containing at least two glycidyl functional groups, selected from the group consisting of: step b) adjusting the pH of the aqueous solution obtained in step a) to a pH of 3 to 11; and Step c) drying the polar phase (PP) obtained from step b) by spraying using an atomizer using an air stream and a nozzle to obtain the polymer (P), wherein the inlet temperature of the air stream is between 80 and 180° C.; The method includes:

2. The method according to claim 1, wherein the polyglutamic acid (PGA) is gamma-polyglutamic acid or PGGA.

3. 3. The method according to claim 2, wherein in step a) all of the monomer units constituting the polyglutamic acid (PGA) are derived from sodium glutamate, potassium glutamate, ammonium glutamate, calcium glutamate, magnesium glutamate or a mixture of these forms.

4. In step a), the polar phase (PP) comprises, per 100% of its mass: - 5% to 70% by weight of said polyglutamic acid (PGA), - 0.025% to 7% by weight of said crosslinker (XLA), - from 23% to 94.975% by weight of said at least one polar solvent (PS), The method according to any one of claims 1 to 3, characterized in that it comprises:

5. 5. The method according to claim 1, characterized in that in step a) the polar solvent (PS) is selected from the group consisting of water, acetone, dimethyl ketone.

6. 6. The method according to claim 5, characterized in that in step a) the polar solvent (PS) is water.

7. Formula (XIV): [C19] 7. The method according to claim 1, further comprising the step of: wherein R4 represents a linear or branched, saturated or unsaturated hydrocarbon-based radical, optionally comprising at least one hydroxyl function, selected from the members of the group consisting of the heptyl, octyl, nonyl, decyl, undecyl, undecenyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, hydroxyoctadecyl, oleyl, linoleyl, linolenyl, eicosyl and dodecosyl radicals.

8. 8. The method according to claim 7, characterized in that the content of the compound of formula (XIV) in the polar phase (PP) is between 0.05% and 35% by weight per 100% by weight of the polar phase (PP), the sum of the mass proportions of the polyglutamic acid (PGA), the crosslinker (XLA), the polar solvent (PS) and the compound of formula (XIV) being understood to be equal to 100%.

9. The method according to claim 1, wherein in step b), the pH is between 4 and 10, preferably between 5 and 7.

10. A method according to any one of the preceding claims, characterized in that the inlet temperature of the air stream is between 100 and 170°C.

11. A cosmetic composition (F) for topical use, comprising from 0.05% to 10% by weight, per 100% of its total weight, of at least one polymer (P) obtained directly by the method according to any one of claims 1 to 10.

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