THICKENING COMPOSITION

Abstract

Thickening composition comprising at least one polymeric microgel, said polymeric microgel being structured by a crosslinking agent of natural origin, and use of this thickening composition in thickened formulations of cosmetic products; detergents or in the manufacture of printing paste in textiles.

Description

Title of the invention: THICKENING COMPOSITION FIELD OF THE INVENTION

[0001] The present invention belongs to the technical field of thickening compositions. More specifically, the subject of the invention is a thickening composition comprising at least one polymeric microgel, said polymeric microgel being structured by a crosslinking agent of natural origin.

[0002] The invention also relates to the use of this thickening composition in the formulation of cosmetic products; in the formulation of detergents or in the manufacture of printing paste in textiles. PREVIOUS ART

[0003] Thickening compositions play an essential role in many industrial application fields. In particular, they make it possible to increase the viscosity of various aqueous preparations thanks to the thickening agents they contain.

[0004] Among these thickening agents we can find polymeric micro-gels. A micro-gel as described in the document "Polymer Networks", Chapter 8, p.227-275, are structured synthetic polymers, spherical in shape whose dimensions are of the order of the size of linear polymer molecules or branched polymers. Micro-gels are microscopic networks whose properties depend on their crosslinking density, their connectivity, the presence of solvent, etc.

[0005] These polymeric microgels exhibit unparalleled application performance, however they are derived from crude oil. However, recent environmental, economic and sustainability issues limit the use of products derived from this limited resource. There is therefore a real need to develop more sustainable and biodegradable polymeric microgels, while being effective.

[0006] To this end, in recent years, the synthesis of hybrid polymers, that is to say of a polymeric entity combining two polymers of different nature, has been the subject of enormous research and development efforts.

[0007] Among these hybrid polymers, we find hybrid polymers combining biopolymers from natural and / or renewable resources, such as polysaccharides, and synthetic polymers from fossil resources.

[0008] Document US 7,666,963 describes the use of a hybrid copolymer comprising a chain transfer agent containing a hydroxyl of natural origin, preferably chosen from polysaccharides. But the document seeks to avoid the formation of a structured polymer.

[0009] There is no solution for the synthesis of a structured polymer included in a water-soluble micro-gel, exhibiting controlled and desired crosslinking for thickening applications.

[0010] Thus the Applicant unexpectedly discovered that the use of a crosslinking agent of natural origin, used according to a predefined ratio, made it possible to optimize the crosslinking of polymeric microgels, to obtain water-soluble microgels, while presenting application performances approaching the application performances of synthetic polymers, in thickening compositions.

[0011] The thickening composition according to the invention is part of a general principle of optimizing application performance, offering opportunities for innovation and development of ever more efficient and environmentally friendly products. Statement of the invention

[0012] The present invention relates to a thickening composition comprising at least one polymeric micro-gel.

[0013] More specifically, the present invention relates to a thickening composition comprising at least one polymeric microgel, characterized in that said polymeric microgel is structured by at least one crosslinking agent of natural origin, the weight ratio; polymeric microgel to crosslinking agent being between 0.1 and 10.

[0014] Even more precisely, the polymeric micro-gel is obtained by radical polymerization of at least one monomer comprising at least one ethylenic unsaturation, and structured by at least one crosslinking agent of natural origin, preferably of polysaccharide origin.

[0015] The present invention also relates to the use of the thickening composition according to the invention, in the formulation of cosmetic products; in the formulation of detergents, or in the manufacture of printing paste in textiles. DETAILED DESCRIPTION OF THE INVENTION

[0016] Throughout this application, the following definitions apply unless specifically indicated otherwise.

[0017] In the context of the invention, a compound “of natural origin” is a compound at least partly of natural origin, preferably totally of natural origin. More precisely, a compound of natural origin is a compound derived partially or totally from biomass or synthesis gas (syngas). It may be the result of one or more chemical transformations carried out on one or more raw materials having a natural, and not fossil, origin.

[0018] According to the invention, the crosslinking agent of natural origin preferably has a biosourced carbon content preferably between 5% by weight and 100% by weight relative to the total weight of carbon of said compound.

[0019] In the context of the invention, ASTM D6866-21, method B, is used to characterize the bio-sourced nature of a chemical compound and to determine the bio-sourced carbon content of said compound. The value is expressed as a percentage by weight of bio-sourced carbon relative to the total weight of carbon in said compound.

[0020] ASTM D6866-21 is a test method that teaches how to experimentally measure the biobased carbon content of solid, liquid, and gaseous samples by radiocarbon analysis.

[0021] Throughout the invention, the bio-sourced carbon content of a compound for which it is specified that it is at least partly of natural origin, or for which the bio-sourced carbon content is specified, relative to the total weight of carbon in said compound, is from 5% by weight to 100% by weight, and preferably from 10% by weight to 100% by weight, preferably from 20% by weight to 100% by weight, preferably from 40% by weight to 100% by weight, preferably from 60% to 100% by weight, preferably from 80% to 100% by weight, the bio-sourced carbon content being measured according to ASTM D6866-21, method B.

[0022] By "polymer microgel" is meant a microgel as described in the document "Polymer Networks", Chapter 8, p.227-275. Microgels are spherical gels composed of structured polymers having a diameter of approximately 0.0 μm to 100 μm. Microgels are microscopic networks whose properties depend on their crosslinking density, their connectivity, the presence of solvent, their hydrated or dehydrated form, etc.They can be in the form of a suspension of pre-hydrated isolated particles, such as in inverse emulsions (EMI), or in the form of dehydrated isolated particles, such as when the inverse emulsion comprising micro-gels is distilled to obtain a partially dehydrated inverse emulsion, or in the form of a solid whose grains are agglomerates of dehydrated micro-gels, such as when the micro-gels are obtained by spray drying of an inverse emulsion comprising micro-gels (PSD) for Polymer Spray Dried, or when the micro-gels are obtained by Precipitation Polymerization (PPP).

[0023] By “crosslinking agent” is meant a radical crosslinking agent capable of forming polymer side chains or of bridging polymer side chains together.

[0024] By "polymer" is meant a homopolymer prepared from a monomer or a copolymer prepared from at least two different monomers, it may therefore be a copolymer of at least two monomers chosen from anionic hydrophilic monomers, cationic hydrophilic monomers, non-ionic hydrophilic monomers, zwitterionic hydrophilic monomers, hydrophobic monomers and mixtures thereof.

[0025] By “hydrophilic monomer” is meant a monomer which has an octanol / water partition coefficient, Kow, less than or equal to 1, in which the partition coefficient Kow is determined at 25°C in an octanol / water mixture having a volume ratio of 1 / 1, at a pH between 6 and 8.

[0026] By "hydrophobic monomer" is meant a monomer which has an octanol / water partition coefficient, Kow, greater than 1, in which the partition coefficient Kow is determined at 25°C in an octanol / water mixture having a volume ratio of 1 / 1, at a pH between 6 and 8.

[0027] The octanol / water partition coefficient, Kow, represents the ratio of concentrations (g / L) of a monomer between the octanol phase and the aqueous phase. It is defined as follows:

[0028] [Math.l] „ [monomer^octanol | monomer J water

[0029] With

[0030] [monomer]octanol = equilibrium concentration of monomer solubility in g / L in n-octanol

[0031] [monomer]water = concentration of the monomer at equilibrium in g / L in water.

[0032] By “X and / or Y”, we mean according to the invention “X”, or “Y”, or “X and Y”.

[0033] Also part of the invention are all possible combinations between the different embodiments disclosed, whether preferred embodiments or given by way of example. Furthermore, when ranges of values ​​are indicated, the limits are part of these ranges. The disclosure also includes all combinations between the limits of these ranges of values. For example, the ranges of values ​​"1-20, preferably 5-15", imply the disclosure of the ranges "1-5", "1-15", "5-20" and "15-20" and the values ​​1, 5, 15 and 20. Thickening composition

[0034] The present invention relates to a thickening composition comprising at least one polymeric micro-gel.

[0035] Advantageously, the thickening composition comprises between 10% and 100% by weight of polymeric micro-gel, relative to the total weight of the thickening composition, preferably between 40% by weight and 100% by weight.

[0036] According to a first aspect of the invention, the thickening composition is advantageously preferably in the form of an inverse emulsion. The latter comprises polymeric microgels dispersed in the lipophilic main phase. When the inverse emulsion is implemented in an aqueous phase, the polymeric microgels are then dispersed in the main aqueous phase.

[0037] According to a first alternative of this aspect, the thickening composition is an inverse emulsion directly obtained via inverse emulsion polymerization. In this case, the thickening composition comprises between 10% and 70% by weight of polymeric microgel, relative to the total weight of the thickening composition, preferably between 40% by weight and 60% by weight.

[0038] According to a second alternative of this same aspect, the thickening composition is a dehydrated inverse emulsion, that is to say an inverse emulsion obtained by inverse emulsion polymerization, on which a distillation step is carried out to remove part of the water.

[0039] According to this first aspect, the thickening composition comprises polymeric microgels, water (generally between 10 and 50% by weight), a solvent or an oil (generally between 5 and 50% by weight), at least one oil-in-water surfactant (generally between 1 and 10% by weight), and at least one water-in-oil surfactant (generally between 1 and 10% by weight).

[0040] According to a second aspect of the invention, the thickening composition is in powder form. The particles of the powder are then dehydrated microgels or agglomerates of dehydrated microgels. When the thickening composition is a powder, it is preferably obtained either by inverse emulsion polymerization which is then dried, for example by spray-drying, or by precipitation polymerization.

[0041] The thickening composition according to the invention is capable of thickening aqueous phases.

[0042] The implementation of the thickening composition according to the invention may be carried out according to the knowledge and practices of the formulators of cosmetic, detergent and textile printing paste formulations. Naturally occurring crosslinking agent

[0043] According to the present invention, the polymeric micro-gel is structured by at least one crosslinking agent of natural origin.

[0044] The crosslinking agent of natural origin is preferably of polysaccharide origin.

[0045] This crosslinking agent comprises at least one polysaccharide chain functionalized by at least one monomeric reagent providing carbon-carbon double bonds on said polysaccharide chain.

[0046] According to the invention, the polysaccharides can be simple or complex synthesized by living organisms.

[0047] As used herein, the term "polysaccharide" includes both so-called native or natural polysaccharides and modified polysaccharides.

[0048] By “modified polysaccharides” this means a polysaccharide that has undergone one or more treatments. These treatments may be physical (mechanical degradation, thermal stress, etc.) and / or chemical (hydrolyzed polysaccharides, acid treatment, etc.) and / or enzymatic in nature.

[0049] Advantageously, the polysaccharide is soluble in water.

[0050] Among these polysaccharides, we can cite by way of example starch and its derivatives, cellulose and its derivatives, hemicellulose, alginates, pectin, agarose, carrageenans, dextran, pullulan, curdlan, amylose, amylopectin, maltodextrin, natural gums. By starch and its derivatives, we mean starch as such and chemically modified starches. The same applies to cellulose.

[0051] According to one embodiment, the polysaccharide is selected from natural gums. Suitable gums are described in Rana, V. et al, Carbohydrate Polymers 83 (2011) 1031-1047 (see, in particular, Table 1). The polysaccharide is then selected from the group consisting of chitosan, xanthan gum, fenugreek gum, tara gum, locust bean gum, carrageenan, guar gum, alginate, agar, tragacanth gum, tamarind gum, gum arabic, cherry gum, karaya gum, okra gum, cassia gum, chicle gum, konjac gum, glucomannan, gum ghatti, pectin, sclerotium gum, gellan gum, their derivatives and combinations thereof. Modified versions of these polymers can also be used.

[0052] The polysaccharide can be modified by amines (primary, secondary, tertiary), amides, esters, ethers, methanes, alcohols, carboxylic acids, tosylates, sulfonates, sulfates, nitrates, phosphates and mixtures thereof.

[0053] Non-limiting examples of such modified polysaccharides include: carboxyl and hydroxymethyl substitutions (e.g., glucuronic acid instead of glucose); amino polysaccharides (amine substitution, e.g., glucosamine instead of glucose); Cr-C6 alkylated polysaccharides; acetylated polysaccharide ethers; polysaccharides to which amino acid residues are attached (small glycoprotein fragments). Suitable examples of such modified polysaccharides include, but are not limited to, amino alginates, such as hexanediamine alginate, amine-functionalized cellulose, such as O-methyl-(Nl,12-dodecanediamine) cellulose, oxidized starches, carboxymethylated dextran, guar polycarboxylic acid, carboxymethylated carob, carboxymethylated locust bean gum, carboxymethylated xanthan, chitosan phosphate, chitosan phosphate, deacetylated chitosan, dodecylamide alginate, sialic acid, glucuronic acid, galacturonic acid, mannuronic acid, guluronic acid, N-acetylgluosamine, N-acetylgalactosamine, carboxymethyl starch, carboxymethyl cellulose, and mixtures thereof.

[0054] Preferably, the polysaccharide has a dextrose equivalent (or DE) of between 0 and 50.

[0055] The measurement of the dextrose equivalent is carried out using the international standard ISO 5377, according to the Lane and Eynon method.

[0056] Dextrose equivalent, or DE, is a unit of measurement used to assess the degree of hydrolysis of a carbohydrate. It represents the proportion of glucose present relative to the total weight of carbohydrates. The higher the DE, the more hydrolysis there is in the product, and the higher the proportion of simple (short-chain) sugars. For example, a DE=0 corresponds to a starch, while a DE=100 corresponds to a product composed entirely of dextrose. Another example, the DE of maltodextrin, varies depending on the production process, but it is between 3-20. This means that maltodextrin contains a range of carbohydrates from short to medium chains.

[0057] The polysaccharide according to the invention can be hydrolyzed by techniques known to those skilled in the art, to obtain a final polysaccharide before functionalization having a DE of between 0-50.

[0058] The polysaccharide that can be used according to the invention is in the form of powder or a concentrated solution.

[0059] According to the present invention, the polysaccharide is functionalized by a monomeric reagent to form the crosslinking agent according to the invention.

[0060] As used herein, the term "monomeric reactant" includes both activated monomers capable of reacting directly with the hydroxyl functions of the polysaccharide and "non-activated" monomers requiring the provision of a coupling agent, said agent reacting with the hydroxyl functions of the polysaccharide and the "non-activated" monomer reacting with the coupling agent.

[0061] As used herein, the term "activated monomer" includes a reactive monomer capable of forming covalent bonds between said monomer and said polysaccharide, preferably on the hydroxyl functions of the polysaccharide.

[0062] Preferably, the monomeric reagent is an activated monomer.

[0063] The monomeric reagent is chosen from anhydrides such as maleic anhydrides, methacrylic anhydrides, itaconic anhydrides; acid and epoxy chlorides, glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether.

[0064] The monomeric reagent may be of natural origin. It may be chosen from itaconic anhydride of natural origin or maleic anhydride of natural origin.

[0065] The crosslinking agent is preferably obtained in the following manner: - A polysaccharide comprising a Dextrose equivalent (DE) of between 0 and 50 is functionalized by adding to a reactor containing said polysaccharide, at least one monomeric reagent by pouring or in one go (one shot). - The pH of the reaction medium is maintained during the reaction between the polysaccharide and the monomeric reagent at a pH between 6 and 10, preferably between 7-9. - The reaction is carried out at atmospheric pressure and at room temperature.

[0066] By "room temperature" is meant a temperature between 10 and 30 °C.

[0067] The crosslinking agent according to the invention preferably has a weight-average molecular weight of between 100 and 1,000,000 Da, preferably between 100 and 100,000 Da, even more preferably between 500 and 5,000 Da.

[0068] The molecular weight is advantageously determined from the intrinsic viscosity of the polymer. The intrinsic viscosity can be measured by methods known to those skilled in the art and can be calculated from the reduced viscosity values ​​for different polymer concentrations by a graphical method consisting of plotting the reduced viscosity values ​​(y-axis) on the concentration (x-axis) and extrapolating the curve to zero concentration. The intrinsic viscosity value is plotted on the y-axis or using the least squares method. The molecular weight can then be determined by the Mark-Houwink equation:

[0069] [Math 2] [î]] = K Ma

[0070] [r|] represents the intrinsic viscosity of the polymer determined by the method of measurement of viscosity in solution.

[0071] K represents an empirical constant.

[0072] M represents the molecular weight of the polymer.

[0073] a represents the Mark-Houwink coefficient.

[0074] K and a depend on the particular polymer-solvent system.

[0075] The crosslinking agent preferably has a degree of substitution of between 10 4 and 10 '. The degree of substitution corresponds to the number of hydroxyl functions of the polysaccharide functionalized by a monomeric reagent over the total number of hydroxyl functions present on the polysaccharide chain before the reaction with the monomeric reagent.

[0076] The measurement of the degree of substitution or (DS) was carried out as described in the article “Position of acetyl groups on anhydroglucose unit in acetylated starches with in- "Intermediate degrees of substitution" by J. Xu and Y.-C. Shi, published in Volume 220, 15 September 2019, Pages 118-125. Polymeric micro-gel

[0077] According to the present invention, the polymeric microgel is obtained by polymerization of at least one monomer having at least one ethylenic unsaturation in the presence of at least one crosslinking agent of natural origin according to the invention. More precisely, the polymeric microgel is obtained by polymerization of at least one monomer having a single ethylenic unsaturation (double bond between two carbon atoms) in the presence of at least one crosslinking agent of natural origin according to the invention.

[0078] The monomers having at least one ethylenic unsaturation are preferentially chosen from non-ionic monomers, anionic monomers, cationic monomers, and / or zwitterionic monomers.

[0079] The sum of the molar percentages of the monomers having at least one ethylenic unsaturation are adjusted by the person skilled in the art, and is equal to 100 mol%.

[0080] The non-ionic monomers are preferably chosen from the group comprising water-soluble vinyl monomers, such as acrylamide, methacrylamide, N-alkylacrylamides, N-alkylmethacrylamides, N,N-dialkyl acrylamides (for example N,N-dimethylacrylamide or N,N-diethylacrylamide), N,N-dialkylmethacrylamides, alkoxylated esters of acrylic acid, alkoxylated esters of methacrylic acid, N-vinylpyrrolidone, N-methylol(meth)acrylamide, N-vinyl caprolactam, N-vinylformamide (NVF), N-vinyl acetamide, N-vinyl imidazole, N-vinyl succinimide, acryloyl morpholine (ACMO), glycidyl methacrylate, glyceryl methacrylate, diacetone acrylamide, methacrylic anhydride, acrylonitrile, maleic anhydride, itaconic anhydride, itaconamide, vinylpyridine, hydroxyalkyl (meth)acrylate, thioalkyl (meth)acrylate, isoprenol and its alkoxylated derivatives,hydroxyethyl(meth)acrylates and their alkoxylated derivatives, hydroxypropylacrylate and its alkoxylated derivatives, vinyl acetate, and mixtures thereof. Among these non-ionic monomers, the alkyl groups are advantageously C1-C5, more advantageously C1-C3. They are preferably linear alkyls.

[0081] Preferably, the structured micro-gel advantageously comprises between 0 and 100 mol% of non-ionic monomers, preferably between 0 and 50 mol%, more preferably between 0 and 10 mol%.

[0082] The anionic monomers are preferentially chosen from acrylic acid; methacrylic acid; dimethylacrylic acid; itaconic acid; crotonic acid; maleic acid; fumaric acid; acrylamido undecanoic acid; 3-acrylamido 3-methylbutanoic acid; maleic anhydride; monomers of strong acid type having for example a sulfonic acid or phosphonic acid function such as vinylsulfonic acid, vinylphosphonic acid, allylsulfonic acid, methallylsulfonic acid, 2-methylidenepropane-1,3-disulfonic acid, 2-sulfoethylmethacrylate, sulfopropylmethacrylate, sulfopropylacrylate, allylphosphonic acid, styrenesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (ATBS), 2-acrylamido-2-methylpropanedisulfonic acid; the water-soluble salts of these monomers such as their alkali metal salts (as distinct from the crystalline form of the sodium salt of 2-acrylamido-2-methylpropanesulfonic acid), alkaline earth metal salts, or ammonium salts; and mixtures thereof.

[0083] By salified is meant the substitution of a proton of at least one acid function of the type -R(=O)-OH (with R= P, S or C) of the anionic monomer by a metal or ammonium cation to form a salt of the type -R(=O)-OX (X being a metal or ammonium cation). In other words, the non-salified form corresponds to the acid form of the monomer, for example RC(=O)-OH in the case of the carboxylic acid function, whereas the salified form of the monomer corresponds to the form RC(=O)-O- X+, X+ corresponding to a metal cation, preferably alkaline or ammonium. The salification of the acid functions of the polymer can be partial or total.

[0084] The salified form advantageously corresponds to the salts of alkali metals (Li, Na, K, etc.), alkaline earth metals (Ca, Mg, etc.) or ammonium (for example the ammonium ion or a tertiary ammonium). The preferred salts are the sodium salts.

[0085] Salification can be done before or after polymerization.

[0086] The polymeric micro-gel advantageously comprises between 0 and 100 mol% of anionic monomers, preferably between 30 and 100 mol%, more preferably between 50 and 100 mol%.

[0087] In a particular embodiment of the invention, the polymeric microgel advantageously comprises between 5 and 50 mol% of anionic monomers in salified form, preferably between 10 and 30 mol%. In a particular embodiment, the anionic hydrophilic monomer(s) may be salified.

[0088] The cationic monomers are preferentially chosen from monomers derived from vinyl-type units (advantageously acrylamide, acrylic, allyl or maleic), these monomers having a phosphonium function, an ammonium salt or quaternary ammonium.

[0089] Mention may be made, in particular and in a non-limiting manner, of diallyldialkyl ammonium salts such as diallyl dimethyl ammonium chloride (DADMAC); acidified or quaternized salts of dialkylaminoalkylacrylamides; acidified or quaternized salts of dialkylaminoalkylmethacrylamides, such as for example methacrylamidopropyl trimethyl ammonium chloride (MAPTAC), chloride of acrylamido-propyl trimethyl ammonium (APTAC), acidified or quaternized salts of dialkyl aminoalkyl acrylate such as quaternized or salified dimethylaminoethyl acrylate (ADAME), acidified or quaternized salts of dialkyl aminoalkyl methacrylate such as quaternized or salified dimethylaminoethyl methacrylate (MADAME) and mixtures thereof. Advantageously, the alkyl groups are C1-C3.

[0090] Furthermore, the present invention also covers monomers of the DADMAC, APTAC and MAPTAC type whose counterion is a sulfate, a fluoride, a bromide or an iodide instead of chloride.

[0091] Preferably, the cationic hydrophilic monomer is dimethylaminoethyl methacrylate in its quaternized form.

[0092] A person skilled in the art will know how to prepare the quaternized monomers, for example using a quaternizing agent of the RX type, R being an alkyl group and X being a halogen or a sulfate.

[0093] By “quaternizing agent” we mean a molecule capable of alkylating a tertiary amine.

[0094] The quaternizing agent may be chosen from dialkyl sulfates comprising from 1 to 6 carbon atoms or alkyl halides comprising from 1 to 6 carbon atoms. Preferably, the quaternizing agent is chosen from methyl chloride, benzyl chloride, dimethyl sulfate or diethyl sulfate.

[0095] The polymeric micro-gel advantageously comprises between 0 and 100 mol% of cationic monomers, preferably between 0 and 85 mol%, more preferably between 0 and 70 mol%, and even more preferably between 0 and 50 mol%.

[0096] The zwitterionic monomers are preferably chosen from derivatives having a vinyl-type unit, in particular acrylamide, acrylic, allyl or maleic. Preferably, this monomer comprises an amine or quaternary ammonium function and an acid function of the carboxylic (or carboxylate), sulfonic (or sulfonate) or phosphoric (or phosphate) type.Mention may be made in particular and in a non-limiting manner of dimethylaminoethyl acrylate derivatives, such as 2-((2-9-(acryloyloxy)ethyl)dimethylammonio)ethane-1-sulfonate, 3-((2-(acryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 4-((2-(acryloyloxy)ethyl)dimethylammonio)butane-1-sulfonate, [2-(acryloyloxy)ethyl](dimethylammonio)acetate, dimethylaminoethyl methacrylate derivatives such as 2-((2-(methacryloyloxy)ethyl)dimethylammonio)ethane-1-sulfonate, 3-((2-(methacryloyloxy)ethyl)dimethylammonio)propane-1-sulfonate, 4-(2-(methacryloyloxy) ethyl)dimethylammonio)butane-l-sulfonate, [2(methacryloyloxy)ethyl](dimethylammonio)acetate, propyla-crylamide dimethylamino derivatives such as 2-((3-acrylamidopropyl)dimethylammonio)ethane-l-sulfonate, . 3-((3-acrylamidopropyl)dimethylammonio)propane-1-sulfonate, 4-((3-acrylamidopropyl) dimethylammonio)butane-1-sulfonate, [3-(acryloyl)oxy)propyl] (dimethylammonio) acetate, dimethylaminopropylmethyla-crylamide, 2-((3-methacrylamidopropyl) dimethylammonio) ethane-1-sulfonate, 3-(dimethylammonio)propane-1-sulfonate-4-((3-methacrylamidopropyl)dimethylammonio)butane-1-sulfonate, propyl [3-(methacryloyloxy)] (dimethylammonio) acetate; and mixtures thereof.

[0097]

[0098] Other zwitterionic monomers are described by the Applicant in document WO21123599.

[0099] Hydrophobic monomers, the partition coefficient Kow of which is greater than 1, may also be used in the preparation of the polymeric microgel according to the invention. They are advantageously chosen, in particular, from (meth)acrylic acid esters having a C4-C30 alkyl, arylalkyl (C4-C30 alkyl, C4-C30 aryl), propoxylated, ethoxylated, or ethoxylated and propoxylated chain; (meth)acrylamide derivatives having a C1-C3 alkyl, arylalkyl propoxylated (C4-C30 alkyl, C4-C30 aryl), ethoxylated, ethoxylated and propoxylated, or dialkyl (C4-C30 alkyl) chain; alkyl aryl sulfonates (C4-C30 alkyl, C4-C30 aryl), or by mono- or di-substituted amides of (meth)acrylamide having a C4-C30 alkyl, arylalkyl (C4-C30 alkyl, C4-C30 aryl), propoxylated, ethoxylated, or ethoxylated and propoxylated chain;(meth)acrylamide derivatives having a C4-C30 alkyl, propoxylated arylalkyl (C4-C30 alkyl, C4-C30 aryl), ethoxylated, ethoxylated and propoxylated, or C4-C30 dialkyl chain; alkyl aryl sulfonates (C4-C30 alkyl, C4-C30 aryl), anionic or cationic monomeric derivatives of (meth)acrylamide or acrylic acid bearing a hydrophobic chain, and mixtures thereof.;

[0100] The hydrophobic monomers may comprise halogen atoms, for example chlorine. Among these hydrophobic monomers:

[0101] - the alkyl groups are preferably C4-C20, more preferably C4-C8. C6-C20 alkyls are preferably linear alkyls while C4-C5 alkyls are preferably branched,

[0102] - the arylalkyl groups are preferably C7-C25, more preferably C7-C15,

[0103] - the ethoxylated chains preferably comprise 6 to 100 -CH2-CH2-O- groups, more preferably 10 to 40,

[0104] - the propoxylated chains preferably comprise 1 to 50 groups - CH2-CH2-CH2-O-, more preferably 1 to 20.

[0105] Preferred monomers belonging to these classes are, for example:

[0106] - n-hexyl (meth)acrylate, n-octyl (meth)acrylate, (meth)acrylamide octyl, lauryl (meth)acrylate, lauryl (meth)acrylamide, myristyl (meth)acrylate, myristyl (meth)acrylamide, pentadecyl (meth)acrylate, pentadecyl (meth)acrylamide, cetyl (meth)acrylate, cetyl (meth)acrylamide, oleyl (meth)acrylate, oleyl (meth)acrylamide, erucyl (meth)acrylate, erucyl (meth)acrylamide, N-tert-Butyl(meth)acrylamide, 2-ethylhexyl acrylate, C4-C22 itaconic acid hemiesters, acidified or quaternized salts of C4-C22 dialkylaminoalkyl (meth)acrylate, acidified or quaternized salts of dialkylaminoalkyl (meth)acrylamides C4-C22, acrylamido undecanoic acid and their combinations.

[0107] - cationic allyl derivatives.

[0108] When the polymer comprises one or more hydrophobic monomers, they are present in such an amount that the polymer remains soluble in water.

[0109] The polymeric micro-gel advantageously comprises less than 10 mol% of hydrophobic monomers.

[0110] Preferably, the polymeric microgel is free of hydrophobic monomers.

[0111] In a particular embodiment, the polymer may comprise at least one LCST group. According to the general knowledge of a person skilled in the art, an LCST group corresponds to a group whose solubility in water for a given concentration is modified beyond a certain temperature and as a function of the salinity. This is a group having a transition temperature upon heating defining its lack of affinity with the solvent medium. The lack of affinity with the solvent results in opacification or a loss of transparency which may be due to precipitation, aggregation, gelation or viscosification of the medium. The minimum transition temperature is called “LCST” (Lower Critical Solution Temperature). For each concentration of LCST group, a transition temperature upon heating is observed.It is greater than the LCST which is the minimum point of the curve. Below this temperature, the polymer is soluble in water, above this temperature, the polymer loses its solubility in water.

[0112] In a particular embodiment, the polymer may comprise at least one UCST group. According to the general knowledge of a person skilled in the art, a UCST group corresponds to a group whose solubility in water for a given concentration is modified below a certain temperature and as a function of the salinity. This is a group having a cooling transition temperature defining its lack of affinity with the solvent medium. The lack of affinity with the solvent results in opacification or loss of transparency which can be due to precipitation, aggregation, gelation or viscosification of the medium. The maximum transition temperature is called "UCST" (Upper Critical Solution Temperature). For each group concentration at UCST, a cooling transition temperature is observed. It is lower than the UCST which is the maximum point of the curve. Above this temperature, the polymer is soluble in water, below this temperature, the polymer loses its solubility in water.

[0113] The sum of the monomers is equal to 100 mol%.

[0114] In a preferred embodiment, the polymeric microgel comprises at least one cationic monomer and at least one non-ionic monomer chosen from the list cited above. According to this embodiment, the polymeric microgel advantageously comprises between 50 and 100 mol% of cationic hydrophilic monomer(s), preferably between 60 and 90 mol%, and between 0 and 50 mol% of non-ionic hydrophilic monomer(s), preferably between 5 and 50 mol%, even more preferably between 5 and 30 mol%.

[0115] According to a second preferred embodiment of the invention, the polymeric micro-gel comprises at least one anionic monomer and optionally at least one non-ionic monomer.

[0116] The polymeric micro-gel advantageously comprises between 0 and 100 mol% of anionic hydrophilic monomer(s), preferably between 30 and 90 mol%, even more preferably between 60 and 90 mol% and between 0 and 50 mol% of anionic hydrophilic monomer(s) in salified form, preferably between 10 and 30 mol%.

[0117] According to these two aspects, the quantities of the different monomer(s) are adjusted by the person skilled in the art so as not to exceed 100 mol% during the preparation of the polymeric micro-gel.

[0118] The polymeric microgel is obtained by radical polymerization. By radical polymerization, we include polymerization by means of photochemical (UV or radiation), azo, thermal, or redox salt initiators, as well as controlled radical polymerization (PCR) techniques.

[0119] As a controlled radical polymerization technique, we can cite, in a non-limiting manner, techniques such as iodine transfer polymerization (ITP), nitroxide-mediated polymerization (NMP), atom transfer (ATRP), reversible addition-fragmentation chain transfer polymerization (RAFT), of which the technology is part MADIX (“MAcromolecular Design by Interchange of Xanthates” in English), various variations of polymerizations with organometallic compounds (“Organometallic Mediated Radical Polymerization” in English (OMRP)), radical polymerization controlled by heteroatomic compounds (“OrganoHeteroatom-mediated Radical Polymerization” in English (OHRP)).

[0120] In a preferred embodiment, the polymerization is carried out by reversible addition-fragmentation chain transfer (“Reversible Addition Fragmentation chain Transfer Polymerization” in English (RAFT)).

[0121] The polymerization is initiated using free radical initiators with one or more of the above hydrophilic and / or hydrophobic monomers, and the polysaccharide(s). As an example of a free radical initiating agent, mention may be made of oxidizing-reducing couples with, among the oxidants, cumene hydroperoxide or tertiary butylhydroxyperoxide, and among the reducers, persulfates such as sodium metabisulfite and Mohr's salt. Azo compounds such as 2,2'-azobis(isobutyronitrile), 2,2'-azobis(2-methylbutyronitrile) and 2,2'-azobis(2-amidinopropane) hydrochloride can also be used as well as peroxide compounds such as benzoyl peroxide, tert-butyl hydroperoxide or lauroyl peroxide.

[0122] According to one aspect of the invention, optionally at least one additional crosslinking agent may be additionally included during the preparation of the polymeric microgel. This additional crosslinking agent is advantageously chosen from polyfunctional agents such as methylenebisacrylamide (MBA), ethylene glycol diacrylate, polyethylene glycol dimethacrylate, diacrylamide, cyanomethylacrylate, vinyloxyethylacrylate, vinyloxymethacrylate, triallylamine, trimethylolpropane triacrylate (TMPTA), tetraallylammonium chloride (TAAC), formaldehyde, glyoxal, glycidyl ethers such as ethylene glycol diglycidyl ether, epoxies and mixtures thereof.

[0123] Preferably, this additional crosslinking agent is methylenebisacrylamide (MBA).

[0124] According to this aspect, the polymeric micro-gel preferably comprises less than 5,000 ppm, by weight relative to the monomers, of crosslinking agent, more preferably between 100 and 5,000 ppm, more preferably between 300 and 3,000 ppm by weight relative to the monomers, even more preferably between 500 and 1,500 ppm by weight relative to the monomers.

[0125] The polymeric microgel can be obtained by different radical polymerization techniques known to those skilled in the art. Advantageously, the polymeric microgel is obtained by inverse emulsion polymerization or by precipitation polymerization. Inverse emulsion

[0126] The thickening composition according to the invention is preferably obtained by inverse emulsion polymerization. The formation of the polymer microgel in the droplet of hydrophilic phase containing the monomers leads to the production of a polymer microgel.

[0127] This polymerization technique is well known to those skilled in the art. It consists of emulsifying a hydrophilic phase comprising the monomer(s) and the crosslinker(s) in a lipophilic phase. This emulsification is carried out using a water-in-oil emulsifying agent.

[0128] According to the present invention, the polymeric micro-gel according to the invention is prepared in inverse emulsion from at least the following compounds:

[0129] - a hydrophilic phase comprising the monomer(s) and at least one reticulating agent culation of natural origin as described previously;

[0130] - a lipophilic phase;

[0131] - at least one emulsifying agent of the water-in-oil type;

[0132] - at least one oil-in-water type emulsifying agent.

[0133] In a preferred embodiment, the thickening composition according to the invention is in the form of an inverse emulsion. It preferably comprises: - A lipophilic phase; - At least one polymeric micro-gel obtained by polymerization of monomers having at least one ethylenic unsaturation in the presence of at least one crosslinking agent of natural origin; - At least one emulsifying agent of the water-in-oil type; - At least one oil-in-water type emulsifying agent.

[0134] An inverse emulsion comprises droplets (hydrophilic phase) dispersed in the lipophilic phase.

[0135] In the present invention, the term "water-in-oil emulsifying agent" refers to a compound capable of emulsifying water in an oil and an "oil-in-water emulsifying agent" is a compound capable of emulsifying an oil in water. Generally, a water-in-oil emulsifying agent is considered to be a surfactant having an HLB strictly less than 8, and an oil-in-water emulsifying agent is considered to be a surfactant having an HLB greater than or equal to 10. A surfactant having an HLB between 8 and 10 is considered to be a wetting agent. Those skilled in the art may refer to the document "Handbook of Applied Surface and Colloid Chemistry" by K. Holmberg, Chapter 11, if necessary.

[0136] The hydrophilic-lipophilic balance (HLB) of a chemical compound is a measure of its hydrophilic and / or lipophilic properties, determined by calculating the values ​​for the different segments of the molecule, as described by Griffin, WC (1949) Classi fication of Surf ace-Active Agents by “HLB”. The Journal of the Society of Cosmetic Chemists, 1, 311-326.

[0137] In the present invention, we have adopted Griffin's method based on calculating a value based on the chemical groups of the molecule. Griffin assigned a dimensionless number between 0 and 20 to give information on the solubility in water and oil.

[0138] The HLB value of a substance having a total molecular weight M and a hydrophilic part of a molecular weight Mh is given by:

[0139] [Math 3]

[0140] HLB = 20(Mh / M)

[0141] The lipophilic phase of the inverse emulsion may comprise a mineral oil, a vegetable oil, a synthetic oil or a mixture of several of these oils.

[0142] Examples of mineral oil are mineral oils containing saturated hydrocarbons of aliphatic, naphthenic, paraffinic, isoparaffinic, cycloparaffinic or naphthyl type.

[0143] Examples of synthetic oil are hydrogenated polydecene or hydrogenated polyisobutene, esters such as octyl stearate or butyl oleate. Exxon's Exxsol® product line is ideally suited.

[0144] The solvent of the hydrophilic phase of the inverse emulsion is advantageously water.

[0145] Generally, the inverse emulsion has, during polymerization, a weight ratio between the hydrophilic phase and the lipophilic phase preferably between 50 / 50 and 90 / 10, more preferably between 60 / 40 and 80 / 20.

[0146] Advantageously, the inverse emulsion contains as at least one emulsifying agent of the water-in-oil type chosen from the following list: sorbitan extracts, such as sorbitan monooleate or sorbitan polyoleates, sorbitan isostearate or sorbitan sesquioleate, polyethoxylated sorbitan esters, diethoxylated oleocetyl alcohol, tetraethoxylated laurylacrylate, condensation products of fatty alcohols higher than ethylene (such as the reaction product of oleyl alcohol with 2 ethylene oxide units), condensation products of alkylphenols and ethylene oxide (such as the reaction product of nonyl phenol with 4 ethylene oxide units), and mixtures thereof. Ethoxylated fatty amines such as Witcamide® 511, betaine products and ethoxylated amine and their mixtures are also good candidates as emulsifying agents.

[0147] Generally, the inverse emulsion comprises between 1 and 10% by weight of water-in-oil type emulsifying agent relative to the total weight of the inverse emulsion.

[0148] Advantageously, the inverse emulsion may comprise stabilizing agents. Examples include: polyesters having a molecular weight of between 1000 and 3000 g / mol, condensation products between a poly(isobutenyl) succinic acid or its anhydride and a polyethylene glycol, water-soluble block polymers having a molecular weight between 2500 and 3500 g / mol, such as those sold under the names Hypermer®.

[0149] Generally, the inverse emulsion comprises between 1 and 10% by weight of stabilizing agents relative to the total weight of the inverse emulsion.

[0150] The oil-in-water emulsifying agent is advantageously chosen from ethoxylated non-nylphenols, preferably having 4 to 10 ethoxylations (i.e. preferably having a degree of ethoxylation ranging from 4 to 10); ethoxylated / propoxylated alcohols preferably having an ethoxylation / propoxylation comprising 12 to 25 carbon atoms; ethoxylated tridecyl alcohols; ethoxylated / propoxylated fatty alcohols; ethoxylated sorbitan esters (advantageously having 20 molar equivalents of ethylene oxide); polyethoxylated sorbitan laurate (advantageously having 20 molar equivalents of ethylene oxide); polyethoxylated castor oil (advantageously having 40 molar equivalents of ethylene oxide); decaethoxylated oleodecyl alcohol; heptaoxyethylated lauryl alcohol; polyethoxylated sorbitan monostearate (advantageously having 20 molar equivalents of ethylene oxide);polyethoxylated alkyl phenols (advantageously having 10 molar equivalents of ethylene oxide) cetyl ether; polyethylene oxide alkyl aryl ether; N-cetyl-N-ethyl morpholinium ethosulfate; sodium lauryl sulfate; condensation products of fatty alcohols with ethylene oxide (advantageously having 10 molar equivalents of ethylene oxide); condensation products of alkylphenols and ethylene oxide (advantageously having 12 molar equivalents of ethylene oxide); condensation products of fatty amines with 5 molar equivalents or more of ethylene oxide (advantageously 5 to 50 equivalents); ethoxylated tristyryl phenols; condensates of ethylene oxide with polyhydric alcohols partially esterified with fatty chains as well as their anhydrous forms; amine oxides advantageously having alkyl polyglucosides; glucamide; phosphate esters; alkylbenzene sulfonic acids and their salts;and water-soluble surfactant polymers. The oil-in-water emulsifying agent may also be a mixture of one or more of these oil-in-water emulsifying agents. The alkyl groups of these oil-in-water emulsifying agents denote linear or branched groups and advantageously having 1 to 20 carbon atoms, more preferably 3 to 15 carbon atoms. In addition, the aryls of these oil-in-water emulsifying agents advantageously comprise 6 to 20 carbon atoms, more preferably 6 to 12 carbon atoms and mixtures thereof. ;

[0151] The inverse emulsion can be partially dehydrated to obtain a dehydrated inverse emulsion (Dewatered inverse emulsion).

[0152] “Generally, the concentration of polymeric microgel in the composition thickening agent obtained by inverse emulsion is between 10 and 70% by weight, preferably between 40 and 60% by weight, relative to the total weight of the thickening composition.

[0153] The polymerization of the monomer(s) is a radical polymerization. By radical polymerization, we include polymerization using UV, azo, redox or thermal initiators. Precipitation polymerization

[0154] According to a second aspect of the present invention, the polymeric microgel is obtained by precipitation polymerization. Precipitation polymerization in a solvent medium consists of the polymerization of monomers soluble in a solvent while the polymer obtained is insoluble, and therefore precipitates in this solvent. Once the polymerization is complete, the polymer appears in the reaction medium in the form of a precipitate. Generally the precipitate is isolated for example by filtration, then dried to obtain a powder.

[0155] Suitable solvents can be polar and non-polar.

[0156] Non-polar solvents include cyclohexane, heptane, benzene, toluene, xylene, ethylbenzene and linear, branched or cyclic alkanes having from 2 to 20 carbon atoms, dichloromethane, ethyl acetate.

[0157] Preferably, the polymeric microgel is polymerized by radical precipitation polymerization in a polar solvent. It is possible to use a polar solvent or a mixture of polar solvents. The mixture of polar solvents preferably comprises water and an alcohol or a ketone.

[0158] The alcohol or ketone are preferably chosen from methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-2 propanol, 1-butanol, 2-butanol, dimethyl ketone, diethyl ketone, pentan-2-one, butanone, tetrahydropyran, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane, 1,4-dioxane. The mixture of polar solvents is preferably a mixture of protic solvents (proton donors).

[0159] In a particular embodiment of the invention, the solvent used for the precipitation polymerization is preferably an alcohol comprising 1 to 4 carbons. It is advantageously chosen from methanol, ethanol, propan-1-ol, isopropanol, tert-butanol or mixtures thereof. Preferably, the solvent used is only tert-butanol.

[0160] The mixture of polar solvents preferably contains up to 10% by weight of water, preferably between 1% and 6% by weight of water and even more preferably between 2 and 4% by weight of water.

[0161] The polymerization is preferably carried out in the absence of oxygen, according to the present invention. Degassing consists of eliminating the residual oxygen in the medium reaction. For this purpose, an inert gas is introduced to degas the reaction medium. The inert gas is usually passed through the solution. Suitable inert gases for this purpose are, for example, nitrogen or carbon dioxide.

[0162] According to one aspect of the invention, surfactants are added in order to stabilize the medium to obtain optimal polymerization conditions. The solution may comprise at least one surfactant having an HLB (Hydrophilic Lipophilic Balance) of less than 15, preferably between 9-13 in order to stabilize said solution and improve the polymerization. Generally the amount of said surfactant in the solution is between 0.2 and 20% by weight, preferably from 1 to 10%.

[0163] The surfactant may be non-ionic, anionic, cationic, amphoteric, zwi-terrionic, preferably it is a non-ionic surfactant. The surfactant(s) are preferably chosen from ethoxylated surfactants, PEG diacrylates, ethoxylated fatty alcohol ethers, saccharide or polyhydric alcohol esters or betaines, esters prepared from alcohol of the glycerol, di-glycerol, triglycerol type or other alcohols such as saccharides like maltinol or sorbitol and mixtures thereof. Advantageously, alkyl polyglucosides are used.

[0164] According to the present invention, the radical precipitation polymerization takes place at a temperature between 60 and 85°C at atmospheric pressure.

[0165] Generally, the concentration of polymeric micro-gel in the thickening composition obtained by precipitation polymerization is between 90 and 100% by weight, preferably between 97 and 100%, relative to the total weight of the thickening composition.

[0166] According to the present invention, the polymeric microgel has a particle size of between 0.05 qm and 50 qm, preferably between 0.5 qm and 10 qm, and even more preferably between 0.5 qm and 2 qm.

[0167] The average size of the polymeric micro-gel is the average size of the diameter, measured by laser granulometry, with a laser measuring device using conventional techniques which are part of the knowledge of the person skilled in the art. A Mastersizer type device from the company Malvern may be used for this purpose.

[0168] Use of the thickening composition according to the invention in thickened formulations

[0169] The present invention also relates to the use of the thickening composition according to the invention in thickened formulations of cosmetic products; detergents; or textile manufacturing.

[0170] The implementation of the thickening composition according to the invention may be carried out according to the knowledge and practices of the formulators of the cos- metics, detergents and textile printing pastes.

[0171] In the present invention, cosmetic formulations also include dermatological and pharmaceutical formulations. They generally comprise an aqueous phase. They are applied in particular to the skin or hair and are generally in the form of oil-in-water emulsions, and sometimes water-in-oil, to form, for example, creams or lotions. Such compositions may, for example, correspond to anti-aging creams or lotions, after-shave care, moisturizing creams, hair coloring lotions, shampoos, conditioners, shower products, cleansing creams, or even ointments or sunscreen creams or lotions. Creams are distinguished from lotions by their higher viscosity.

[0172] Thickening compositions are widely used in these cosmetic formulations to adapt their sensory profile (appearance, application) to consumer requirements, but also to suspend or stabilize active ingredients.

[0173] By thickened detergent formulations is meant formulations for cleaning various surfaces, in particular textile fibers, hard surfaces of any kind such as dishes, floors, windows, wooden, metal or composite surfaces. Such formulations correspond, for example, to detergents for washing clothes manually or in a washing machine, products for cleaning dishes manually or for dishwashers, detergent products for washing home interiors such as kitchen units, toilets, furnishings, floors, windows, and other cleaning products for universal use.

[0174] Cosmetic and detergent formulations may also contain other ingredients well known to those skilled in the art such as water, mineral or vegetable oils, organic solvents, surfactants, cosmetic or pharmaceutical active ingredients, vitamins, chelating agents, emollients, moisturizing agents, botanical extracts, sunscreens, detergent or cleaning adjuvants, fluorescent agents, foaming agents or foam suppressants, neutralizing agents, pH adjusting agents, preservatives, perfumes, opacifying compounds, colorants, without this list being limiting. Those skilled in the art know how and with which ingredients they can formulate a cosmetic or detergent formulation.For cosmetic formulations, reference may be made to application FR 2 979 821, and for detergent compositions, reference may be made to documents FR 2 766 838, FR 2 744 131, EP 0 759 966.

[0175] Advantageously, the thickened formulation comprises between 0.1% and 10% by weight of polymeric micro-gel, relative to the total weight of the thickened formulation, preferably between 0.3% by weight and 7% by weight, even more preferably 0.5% by weight and 3% weight.

[0176] Another subject of the invention relates to a cosmetic or detergent formulation or textile printing paste thickened with at least one thickening composition according to the invention. EXAMPLES

[0177] The following examples best illustrate the advantages of the invention in a clear and non-limiting manner. I. Synthesis of polymeric microgels

[0178] Preparation of the crosslinking agent of natural origin M

[0179] An aqueous solution is prepared by dispersing 280g of maltodextrin in 280g of deionized water. 1.54g of 30% sodium hydroxide and 1.96g of methacrylic anhydride are then added dropwise. The addition of 30% sodium hydroxide is stopped before the end of the addition of the methacrylic anhydride to allow the pH to be adjusted between 6.5 and 7.

[0180] Example 1: Composition A: Synthesis of polymeric micro-gels PI by reverse emulsion polymerization 1. Aqueous phase

[0181] The aqueous phase is prepared by mixing acrylic acid (91.93g), deionized water (23.59g), methylene-bis-acrylamide (0.46g) and 0.56g of penta sodium salt of diethylenetriamine penta acetic acid (Versenex® 80).

[0182] The aqueous phase is neutralized with 20.41g of a 50% sodium hydroxide solution.

[0183] The aqueous solution comprising the crosslinking agent of natural origin, prepared above in I, is added to this aqueous phase. The mixture is kept stirring for 10 minutes for homogenization. 2. Organic phase

[0184] Octyldodecyl myristate (171.55g) and Isopar® J (100.95g) are added to an IL reactor. Primary surfactants are added: 5g of Span 80, 10g of Hypermer® 6212 and 12.5g of a stearyl methacrylate.

[0185] The organic phase is stirred for 10 minutes to homogenize it. 3. Formation and polymerization of the emulsion

[0186] The aqueous phase prepared in 1. is added to the reactor containing the organic phase prepared in 2. and kept stirring.

[0187] This mixture is emulsified and degassed by bubbling nitrogen for 30 minutes before initiating polymerization by co-pouring solutions of reducer (sodium metabisulfite) and oxidant (tert-butyl hydroperoxide).

[0188] A rotary agitator is used to place the emulsion under a pressure of 80mbar at 90°C in order to remove the water and Isopar® J to concentrate the emulsion.

[0189] After cooling the emulsion, an alkyl polyglucoside type reversing surfactant is added (10% by weight) with stirring.

[0190] An inverse emulsion is thus obtained.

[0191] Example 2: Composition B: Synthesis of polymeric micro-gels P2 by precipitation polymerization

[0192] In a double jacketed IL reactor equipped with an air inlet on the bottom and equipped with a reflux condenser and a thermometer, 450g of tert-butanol comprising 2.5% by mass of distilled water are placed under the stirring of a half-moon blade. 25g of maltodextrin are dispersed in the reactor before adjusting the pH to 9 by bubbling ammonia. Methacrylic anhydride (0.2g) is then added, and stirring is maintained for 30 minutes. 2-acrylamido-2-methylpropane sulfonic acid (ATBS, 60g) is then added before bubbling ammonia again for 30 minutes, taking care to keep the pH below 7.

[0193] The reaction medium is degassed by bubbling nitrogen for at least thirty minutes, before adding trimethylolpropane triacrylate (TMPTA) and gradually heating to reach 70°C using a thermostatically controlled bath. The polymerization initiator (di-lauroyl peroxide, 0.6g) is then added.

[0194] The polymerization, exothermic, reaches a maximum temperature at which the medium is maintained at reflux for two hours.

[0195] A white precipitate forms, indicating the successful synthesis of the hybrid polymer. By evaporating the solvent using a rotary evaporator (90°C, 100 mbar), the precipitate is collected and dried for 12 hours at 70°C.

[0196] A composition in powder form is thus obtained.

[0197] II. Preparation of thickened formulations comprising the thickening compositions according to the invention.

[0198] Table 1 below details the viscosity of different formulations: - Formulation A comprises 1% by weight of thickening composition A and 99% by weight of water. - Formulation B comprises 1% by weight of thickening composition B and 99% by weight of water. - Formulation C comprises 1% by weight of a thickening composition C and 99% by weight of water. Said thickening composition C comprises polyacrylate microgels which have not been structured with a crosslinking agent of natural origin, said microgels having been obtained via an inverse emulsion process (EMI). - Formulation D comprises 1% by weight of a thickening composition D and 99% by weight of water. Said composition D comprises polyacrylate-type microgels which have not been structured with a crosslinking agent of natural origin, said micro-gels having been obtained via a precipitation polymerization process (PPP).

[0199] [Tableauxl] Formulation A (Invention) Formulation B (Invention) Formulation C (Counterexample) Formulation D (Counterexample) Brookfield RVT Viscosity 20 rpm 1% aq. 25,000 cP 10,000 cP 35,000 cP 12,000 cP

[0200] Brookfield viscosity is measured on formulations at 1% by weight in water with a Brookfield viscometer RVT module with a rotation speed of 20 rpm.

[0201] The compositions according to the invention make it possible to obtain formulations presenting a significantly interesting alternative, compared to thickening compositions comprising current polymeric micro-gels which have not been structured with a crosslinking agent of natural origin.

Claims

Claims

1. Thickening composition comprising at least one polymeric micro-gel, characterized in that said polymeric micro-gel is structured by at least one crosslinking agent of natural origin, the weight ratio between the polymeric micro-gel and said crosslinking agent of natural origin being between 0.1 and 10.

2. Thickening composition according to claim 1, characterized in that the crosslinking agent of natural origin is derived partially or totally from biomass or synthesis gas.

3. Thickening composition according to one of claims 1 or 2, characterized in that the crosslinking agent of natural origin has a biosourced carbon content preferably between 5% by weight and 100% by weight relative to the total weight of carbon of said crosslinking agent, the biosourced carbon content being measured according to standard ASTM D6866-21, method B.

4. Thickening composition according to one of claims 1 to 3, characterized in that the crosslinking agent comprises at least one polysaccharide chain functionalized by at least one monomeric reagent providing carbon-carbon double bonds on said polysaccharide chain.

5. Thickening composition according to claim 4, characterized in that the monomeric reagent is chosen from maleic anhydrides, methacrylic anhydrides, itaconic anhydrides; acid and epoxy chlorides, glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether.

6. Thickening composition according to one of claims 4 or 5, characterized in that the polysaccharide is chosen from starch and its derivatives, cellulose and its derivatives, hemicellulose, alginates, pectin, agarose, carrageenans, dextran, pullulan, curdlan, amylose, amylopectin, maltodextrin and natural gums.

7. Thickening composition according to any one of the preceding claims, characterized in that the crosslinking agent has a degree of substitution of between 10 4 and 10 '.

8. Thickening composition according to any one of the preceding claims, characterized in that the crosslinking agent has a weight average molecular weight of between 100 and 1,000,000 Da.

9. Thickening composition according to any one of the preceding claims, characterized in that the polymeric micro-gel comprises at least one hydrophilic monomer comprising at least one unsaturated ethylenic function chosen from non-ionic and / or anionic and / or cationic.

10. Thickening composition according to any one of the preceding claims, characterized in that the polymeric microgel comprises at least one hydrophilic monomer comprising at least one unsaturated ethylenic function chosen from; acrylamide, acrylic acid, an oligomer of acrylic acid, 2-acrylamido-2-methylpropane sulfonic acid (ATBS) and / or one of its salts, N-vinylformamide (NVF), N-vinylpyrrolidone (NVP), dimethyldiallylammonium chloride (DADMAC), quaternized dimethylaminoethyl acrylate (ADAME), quaternized dimethylaminoethyl methacrylate (MADAME).

11. Thickening composition according to any one of the preceding claims, characterized in that the polymeric micro-gel has a particle size of between 0.05 qm and 50 qm.

12. Thickening composition according to any one of the preceding claims, characterized in that said composition comprises between 10% and 100% by weight of polymeric micro-gel.

13. Use of the thickening composition according to one of claims 1 to 12, in thickened formulations of cosmetic products; detergents; or in the manufacture of textiles.

14. Cosmetic or detergent formulation or textile printing paste thickened with at least one thickening composition according to one of claims 1 to 12.