Thickened composition

Abstract

The present invention provides a thickening composition comprising at least one polymeric microgel structured with a crosslinking agent of natural origin and the use of said thickening composition in thickened formulations of cosmetics and detergents or in printing pastes in the manufacture of textiles.

Description

Technical Field

[0001] This invention belongs to the field of thickening composition technology. More specifically, this invention relates to a thickening composition comprising at least one polymer microgel, said polymer microgel being structured with a naturally derived crosslinking agent.

[0002] The present invention also relates to the use of this thickening composition in cosmetic formulations, detergent formulations, or in printing pastes used in the manufacture of textiles. Background Technology

[0003] Thickening compositions play a vital role in many industrial applications. Specifically, thickening compositions increase the viscosity of various aqueous formulations due to the thickeners contained in these formulations.

[0004] One type of thickener that may be encountered is polymer microgels. As described in the literature *Polymer Networks*, Chapter 8, pp. 227-275, microgels are structured synthetic polymers with a spherical shape and a size comparable to that of linear or branched polymer molecules. Microgels are microscopic networks whose properties depend on their crosslinking density, connectivity, and the presence of solvents.

[0005] These polymer microgels are characterized by unparalleled performance qualities; however, they are derived from petroleum. Recent environmental, economic, and sustainability concerns have limited the use of products derived from this finite resource. Therefore, there is a real need to develop more durable, biodegradable, and effective polymer microgels.

[0006] In this regard, a great deal of research and development work has been carried out in recent years on the synthesis of hybrid polymers (i.e., polymer entities that combine two different types of polymers).

[0007] These hybrid polymers encompass those that combine biopolymers derived from natural and / or renewable resources (such as polysaccharides) with synthetic polymers derived from fossil resources.

[0008] Document US 7,666,963 describes the use of hybrid copolymers containing chain transfer agents, said chain transfer agents comprising naturally derived hydroxyl compounds, preferably selected from polysaccharides. However, this document seeks to avoid the formation of structured polymers.

[0009] There is no solution for synthesizing water-soluble microgel-structured polymers that exhibit the type of controlled crosslinking required for thickening applications.

[0010] Therefore, the applicant unexpectedly discovered that using a naturally sourced crosslinking agent at a predetermined ratio can optimize the crosslinking of polymer microgels to obtain water-soluble microgels, while exhibiting performance characteristics close to those of synthetic polymers in the thickening composition.

[0011] The general principle for controlling the thickening compositions according to the present invention is to optimize performance characteristics, thereby opening up opportunities for innovation and development of higher-performance and more environmentally friendly products. Summary of the Invention

[0012] This invention relates to a thickening composition comprising at least one polymer microgel.

[0013] More specifically, the present invention relates to a thickening composition comprising at least one polymeric microgel. Its characteristics are At The polymer microgel is structured with at least one crosslinking agent of natural origin, and the weight ratio of the polymer microgel to the crosslinking agent is between 0.1 and 10, preferably between 0.30 and 5, and more preferably between 0.35 and 2.59.

[0014] In one embodiment, the naturally derived crosslinking agent is partially or entirely derived from biomass or syngas. In a specific embodiment, the bio-based carbon content of the naturally derived crosslinking agent is preferably between 5% by weight and 100% by weight relative to the total weight of carbon in the crosslinking agent, and the bio-based carbon content is measured according to standard ASTM D6866-21, Method B.

[0015] In a preferred embodiment, the crosslinking agent comprises at least one polysaccharide chain, the at least one polysaccharide chain being functionalized with at least one monomer reactant that provides carbon-carbon double bonds to the polysaccharide chain.

[0016] In one embodiment, the monomer reactants are selected from maleic anhydride, methacrylic anhydride, itaconic anhydride, acid chloride, epoxy chloride, glycidyl methacrylate, glycidyl acrylate, and allyl glycidyl ether.

[0017] Preferably, the polysaccharide is selected from starch and its derivatives, cellulose and its derivatives, hemicellulose, alginate, pectin, agarose, carrageenan, dextran, pullulan, gelatin, amylose, amylopectin, maltodextrin, and natural gums.

[0018] According to one embodiment of the present invention, in the thickening composition, the degree of substitution of the crosslinking agent is between 10. -4 With 10 -1 between.

[0019] In another embodiment of the invention, the weight-average molecular weight of the crosslinking agent is between 100 Da and 1,000,000 Da.

[0020] According to another embodiment of the invention, in the thickening composition, the polymer microgel comprises at least one hydrophilic monomer, the at least one hydrophilic monomer comprising at least one unsaturated olefinic functional group selected from nonionic and / or anionic and / or cationic functional groups. Preferably, the polymer microgel comprises at least one hydrophilic monomer, the at least one hydrophilic monomer comprising at least one unsaturated olefinic functional group selected from: acrylamide, acrylic acid, oligomers of acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid (ATBS) and / or its salts, N-vinylformamide (NVF), N-vinylpyrrolidone (NVP), dimethyl diallyl ammonium chloride (DADMAC), quaternized dimethylaminoethyl acrylate (DMAEA), and quaternized dimethylaminoethyl methacrylate (DMAEMA).

[0021] In one specific embodiment, the polymer microgel in the thickening composition has a particle size between 0.05 µm and 50 µm.

[0022] In yet another embodiment of the invention, the thickening composition comprises 10% to 100% by weight of polymeric microgels.

[0023] More specifically, the polymer microgel is obtained by free radical polymerization of at least one monomer containing at least one degree of olefinic unsaturation, and is structured with at least one crosslinking agent of natural origin, preferably polysaccharide origin. The polymer microgel is included in the thickening composition according to the invention.

[0024] The present invention also relates to the use of the thickening compositions according to the invention in cosmetic formulations, detergent formulations, or in printing pastes used in the manufacture of textiles.

[0025] In another embodiment, the present invention relates to a cosmetic or detergent or textile printing paste formulation, which is thickened with at least one thickening composition according to the present invention.

[0026] In addition, the present invention relates to a polymer microgel obtained by free radical polymerization of at least one monomer and structured with at least one crosslinking agent of natural origin, said at least one monomer comprising at least one unsaturated olefinic functional group selected from nonionic and / or anionic and / or cationic functional groups. Detailed Implementation

[0027] Throughout this application, unless otherwise specifically instructed, the following definitions apply.

[0028] In the context of this invention, a "naturally derived" compound is one that is at least partially naturally derived, and preferably entirely naturally derived. More specifically, a naturally derived compound is one that is partially or entirely derived from biomass or from syngas. It can be the result of one or more chemical transformations of one or more starting materials derived from natural and non-fossil sources.

[0029] According to the present invention, the naturally derived crosslinking agent preferably has a bio-based carbon content, preferably between 5% by weight and 100% by weight, relative to the total weight of carbon in the compound.

[0030] In the context of this invention, standard ASTM D6866-21, Method B, is used to characterize the bio-based properties of chemical compounds and determine the bio-based carbon content of said compounds. This value is expressed as a weight percentage of bio-based carbon relative to the total weight of carbon in said compound.

[0031] The standard ASTM D6866-21 is a test method that experimentally measures the bio-based carbon content of solid, liquid, and gaseous samples through radiocarbon analysis.

[0032] Throughout this invention, the bio-based carbon content of compounds designated as having at least a partial natural source or compounds designated as having a bio-based carbon content is 5% to 100% by weight relative to the total weight of carbon in the compounds, and preferably 10% to 100%, preferably 20% to 100% by weight, preferably 40% to 100% by weight, preferably 60% to 100% by weight, preferably 80% to 100% by weight, said bio-based carbon content being measured according to standard ASTM D6866-21, method B.

[0033] "Polymer microgels" refer to microgels as described in the literature *Polymer Networks*, Chapter 8, pp. 227-275. Microgels are spherical gels composed of structured polymers with diameters ranging from approximately 0.01 µm to 100 µm. Microgels are microscopic networks whose properties depend on their crosslinking density, connectivity, the presence of solvents, and their hydration or dehydration form. Microgels can take the form of a suspension of separated prehydrated particles, such as in an inverse emulsion (IEM), or as separated dehydrated particles, such as when distilling an inverse emulsion containing microgels to obtain a partially dehydrated inverse emulsion, or further as solids where the particles are aggregates of dehydrated microgels, such as when obtaining microgels by spray drying (polymer spray drying; PSD) of an inverse emulsion containing microgels, or when obtaining microgels through a precipitation polymerization (PPP) process.

[0034] "Crosslinking agent" refers to a free radical crosslinking agent that can form polymer side chains or bridge polymer side chains together.

[0035] "Polymer" means a homopolymer prepared from a monomer, or a copolymer prepared from at least two different monomers, which can therefore be a copolymer of at least two monomers selected from the following: anionic hydrophilic monomers, cationic hydrophilic monomers, nonionic hydrophilic monomers, zwitterionic hydrophilic monomers, hydrophobic monomers and mixtures thereof.

[0036] "Hydrophilic monomer" refers to a monomer with an octanol / water partition coefficient Kow (expressed as Log) less than or equal to 1.5, where the partition coefficient Kow is determined at 25°C in a 1 / 1 volume mixture of octanol and water at a pH between 6 and 8. For clarity, log Kow < 1.5 for hydrophilic monomers.

[0037] "Hydrophobic monomer" refers to a monomer with an octanol / water partition coefficient Kow (expressed as Log) greater than 1.5, where the partition coefficient Kow is determined at 25°C in a 1 / 1 volume mixture of octanol and water with a pH between 6 and 8.

[0038] The octanol / water partition coefficient Kow represents the concentration ratio (g / L) of the monomer between the octanol phase and the aqueous phase. Its definition is as follows: [Mathematics 1]

[0039] in =Equilibrium concentration of monomer in n-octanol, in g / L; = The equilibrium concentration of the monomer in water, expressed in g / L.

[0040] According to the present invention, "X and / or Y" means X, or Y, or X and Y.

[0041] All possible combinations of the disclosed embodiments are also part of the invention, whether they are preferred embodiments or embodiments given by way of example. Furthermore, when indicating a range of values, endpoints constitute part of those ranges. This disclosure also includes all combinations of the endpoints of these ranges of values. For example, a range of values ​​1-20, preferably 5-15, means the disclosure of ranges 1-5, 1-15, 5-20, and 15-20, as well as values ​​1, 5, 15, and 20.

[0042] Thickening composition This invention relates to a thickening composition comprising at least one polymer microgel.

[0043] The thickening composition advantageously contains 10% to 100% by weight of polymer microgels relative to the total weight of the thickening composition, preferably 20% to 100% by weight, and most preferably 40% to 100% by weight.

[0044] According to a first aspect of the invention, the thickening composition is advantageously in the form of an inverse emulsion. This emulsion comprises polymeric microgels dispersed in a predominantly lipophilic phase. When an inverse emulsion is used in an aqueous phase, the polymeric microgels are subsequently dispersed in the predominantly aqueous phase.

[0045] According to a first alternative in this regard, the thickening composition is a reverse emulsion obtained directly via reverse emulsion polymerization. In this case, the thickening composition contains 10% to 70% by weight of polymer microgels, preferably 40% to 60% by weight, relative to the total weight of the thickening composition.

[0046] According to a second alternative of the same aspect, the thickening composition is a dehydrated reverse emulsion, which means that the reverse emulsion is obtained by reverse emulsion polymerization and then subjected to a distillation step to remove some of the water.

[0047] According to this first aspect, the thickening composition comprises a polymer microgel, water (typically between 10% and 50% by weight), a solvent or oil (typically between 5% and 50% by weight), at least one oil-in-water surfactant (typically between 1% and 10% by weight), and at least one water-in-oil surfactant (typically between 1% and 10% by weight).

[0048] According to a second aspect of the invention, the thickening composition is in powder form. In this case, the particles in the powder are dehydrated microgels or aggregates of dehydrated microgels. When the thickening composition is a powder, it is preferably obtained by reverse emulsion polymerization followed by drying of the emulsion (e.g., by spray drying), or by precipitation polymerization.

[0049] The thickening composition according to the present invention can thicken an aqueous phase.

[0050] The thickening compositions according to the present invention can be used based on the knowledge and practice of formulators of cosmetic formulations, detergents and textile printing pastes.

[0051] Naturally derived crosslinking agents According to the present invention, the polymer microgel is structured using at least one crosslinking agent from a natural source.

[0052] The cross-linking agent of natural origin is preferably of polysaccharide origin.

[0053] This crosslinking agent comprises at least one polysaccharide chain, said at least one polysaccharide chain being functionalized with at least one monomer reactant, said at least one monomer reactant providing carbon-carbon double bonds to said polysaccharide chain.

[0054] According to the present invention, the polysaccharide can be a simple or complex polysaccharide synthesized by a living organism.

[0055] As used in this article, the term "polysaccharide" includes both so-called native / natural polysaccharides and modified polysaccharides.

[0056] "Modified polysaccharide" refers to polysaccharide that has undergone one or more treatments. These treatments can be physical (mechanical degradation, thermal stress, etc.) and / or chemical (hydrolysis of polysaccharide, acid treatment, etc.) and / or enzymatic.

[0057] Polysaccharides are readily soluble in water.

[0058] These polysaccharides include, for example, starch and its derivatives, cellulose and its derivatives, hemicellulose, alginate, pectin, agarose, carrageenan, dextran, pullulan, gelatin, amylose, amylopectin, and natural gums. Starch and its derivatives refer to starch itself, hydrolyzed starch (including dextrin and maltodextrin), and chemically modified starch.

[0059] Cellulose and its derivatives refer to cellulose itself, hydrolyzed cellulose, and chemically modified cellulose.

[0060] 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 Table 1 for details). In this case, the polysaccharide is selected from the group consisting of: chitosan, xanthan gum, fenugreek gum, tarara gum, carob gum, carrageenan, guar gum, alginate, agar, tragacanth gum, tamarind gum, gum arabic, cherry gum, karaya gum, okra gum, cassia gum, chiclegum, konjac gum, glucomannan, ghatti gum, pectin, sclerotium gum, gellan gum, derivatives thereof, and combinations thereof. Modified versions of these polymers may also be used.

[0061] Polysaccharides can be modified with amines (primary amines, secondary amines, tertiary amines), amides, esters, ethers, urethanes, alcohols, carboxylic acids, toluenesulfonates, sulfonates, sulfates, nitrates, phosphates, and mixtures thereof.

[0062] Non-limiting examples of these modified polysaccharides include: carboxyl and hydroxymethyl substitutions (e.g., glucuronic acid instead of glucose); aminopolysaccharides (amine substitutions, e.g., glucosamine instead of glucose); C1-C6 alkyl polysaccharides; and acetylated polysaccharide ethers; and polysaccharides linked with amino acid residues (small fragments of glycoproteins). Suitable examples of these modified polysaccharides include aminoalginates (such as hexamethylenediamine alginate), amine-functionalized cellulose (such as O-methyl-N-(1,12-dodecanediamine)cellulose), oxidized starch, carboxymethyl dextran, guar polycarboxylic acid, carboxymethyl carob, carboxymethyl carob gum, carboxymethyl xanthan gum, chitosan phosphate, chitosan phosphate sulfate, deacetylated chitosan, dodecylamide alginate, sialic acid, glucuronic acid, galacturonic acid, mannuronic acid, guluronic acid, N-acetylglucosamine, N-acetylglucosamine, carboxymethyl starch, carboxymethyl cellulose, hydroxyethyl cellulose (HEC), hydroxypropyl guar gum (HPG), and mixtures thereof.

[0063] Some polysaccharides, such as starch in particular, can be characterized by their dextran equivalent (DE) value.

[0064] The dextran equivalent (or DE) of the polysaccharide is preferably between 0 and 50.

[0065] The dextran equivalent was measured according to the international standard ISO 5377 using the Lane and Eynon method.

[0066] Dextran equivalent, or DE, is a unit of measurement used to evaluate the degree of hydrolysis of carbohydrates. It represents the proportion of glucose present relative to the total weight of carbohydrates. The higher the DE, the greater the hydrolysis in the product, and the higher the proportion of monosaccharides (short-chain sugars). For example, DE = 0 corresponds to starch, while DE = 100 corresponds to a product composed entirely of dextrose. Another example is maltodextrin, where the DE varies depending on the production process but ranges from 3 to 20. This means that maltodextrin contains a range of carbohydrates with short to medium chains.

[0067] In some embodiments of the present invention, the polysaccharides according to the present invention can be hydrolyzed using techniques known to those skilled in the art to obtain a final polysaccharide with a DE of 0-50 before functionalization.

[0068] The polysaccharides used according to the present invention can be in the form of powder or concentrated solution.

[0069] According to the present invention, polysaccharides are functionalized with monomer reactants to form crosslinking agents according to the present invention.

[0070] As used herein, the term "monomer reactant" includes not only activated monomers that enable direct reaction with the hydroxyl functional groups of polysaccharides, but also "inactivated" monomers that require the addition of a coupling agent that reacts with the hydroxyl functional groups of the polysaccharides, and "inactivated" monomers that react with the coupling agent.

[0071] As used herein, the term "activated monomer" includes a reactive monomer capable of forming a covalent bond between the monomer and the polysaccharide, preferably on the hydroxyl functional group of the polysaccharide.

[0072] The monomer reactant is preferably an activated monomer.

[0073] The monomer reactants are selected from acid anhydrides (such as maleic anhydride, methacrylic anhydride and itaconic anhydride), acid chlorides, epoxy chlorides, glycidyl methacrylate, glycidyl acrylate and allyl glycidyl ether.

[0074] The monomer reactants can be of natural origin. They can be selected from naturally sourced itaconic anhydride or naturally sourced maleic anhydride.

[0075] In some embodiments of the present invention, the crosslinking agent is preferably obtained in the following manner: - To functionalize a polysaccharide with a dextran equivalent (DE) of 0 to 50 by adding or in a single go (one shot) at least one monomeric reactant into a reactor containing the polysaccharide.

[0076] - During the reaction of polysaccharides with monomer reactants, the pH of the reaction medium is maintained between pH 6 and 10, preferably 7-9.

[0077] The reaction takes place at atmospheric pressure and ambient temperature.

[0078] "Ambient temperature" should be understood as a temperature between 15°C and 30°C.

[0079] The weight-average molecular weight of the crosslinking agent according to the present invention is preferably between 100 Da and 1,000,000 Da, more preferably between 100 Da and 100,000 Da, and more preferably between 500 Da and 5,000 Da.

[0080] Molecular weight is advantageously determined by the intrinsic viscosity of the polymer. Intrinsic viscosity can be measured by methods known to those skilled in the art and can be calculated graphically based on the reduced viscosity values ​​of polymers at different concentrations, the graphical method involving plotting the reduced viscosity values ​​(y-axis) relative to concentration (x-axis) and extrapolating the curve to zero concentration. Intrinsic viscosity values ​​can be plotted on the y-axis or using the least squares method. The molecular weight can then be determined using the Mark-Houwinke equation: [Mathematics 2] [η] = K Mα [η] represents the intrinsic viscosity of the polymer, which is determined by measuring the viscosity in a solution.

[0081] K represents an empirical constant.

[0082] M represents the molecular weight of the polymer.

[0083] α represents the Mark-Houwink coefficient.

[0084] K and α depend on the specific polymer-solvent system.

[0085] The degree of substitution of the crosslinking agent is preferably between 10. -4 With 10 -1 The degree of substitution corresponds to the number of hydroxyl functional groups in the polysaccharide functionalized with the monomer reactant relative to the total number of hydroxyl functional groups present on the polysaccharide chain before reaction with the monomer reactant.

[0086] The method for measuring the degree of substitution (DS) is described in the following article: "Position of acetyl groups on anhydroglucoseunit in acetylated starches with intermediate degrees of substitution", J. Xu and Y.-C. Shi, Carbohydrate Polymers, Vol. 220, September 15, 2019, pp. 118-125.

[0087] Polymer microgels According to the present invention, polymer microgels are obtained by polymerizing at least one monomer having at least one degree of olefinic unsaturation in the presence of at least one naturally sourced crosslinking agent according to the present invention. More specifically, polymer microgels are obtained by polymerizing at least one monomer having a single degree of olefinic unsaturation (a double bond between two carbon atoms) in the presence of at least one naturally sourced crosslinking agent according to the present invention.

[0088] The monomer having at least one degree of olefinic unsaturation is preferably selected from nonionic monomers, anionic monomers, cationic monomers and / or zwitterionic monomers.

[0089] The sum of the molar percentages of monomers having at least one degree of olefinic unsaturation is adjusted by those skilled in the art and is equal to 100 mol.

[0090] The nonionic monomer is preferably selected from the group consisting of: water-soluble vinyl monomers, such as acrylamide, methacrylamide, N-alkylacrylamide, N-alkylmethylacrylamide, N,N-dialkylacrylamide (e.g., N,N-dimethylacrylamide or N,N-diethylacrylamide), N,N-dialkylmethylacrylamide, alkoxy esters of acrylic acid, alkoxy esters of methacrylic acid, N-vinylpyrrolidone, N-hydroxymethyl (meth)acrylamide, N-vinylcaprolactam, N-vinylformamide (NVF), N-vinylacetamide, N-vinylimazole, N-vinylsuccinimide, acrylamide (ACMO), glycidyl methacrylate, glyceryl methacrylate, diacetone acrylamide, methacrylic anhydride, acrylonitrile, maleic anhydride, itaconic anhydride, itaconamide, vinylpyridine, hydroxyalkyl (meth)acrylate, thioalkyl (meth)acrylate, its isoprene alcohol and alkoxy derivatives, hydroxyethyl (meth)acrylate and its alkoxy derivatives, hydroxypropyl acrylate and its alkoxy derivatives, vinyl acetate and mixtures thereof. In these nonionic monomers, the alkyl group is advantageously C1-C5, more advantageously C1-C3. Preferably, it is a straight-chain alkyl group.

[0091] The structured microgel preferably contains 0 mol% to 100 mol% of nonionic monomers, preferably 0 mol% to 50 mol%, more preferably 0 mol% to 10 mol%.

[0092] The anionic monomers are preferably selected from acrylic acid, methacrylic acid, dimethacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, acrylamide undecanoic acid, 3-acrylamido-3-methylbutyric acid, and maleic anhydride; for example, strong acid monomers having sulfonic or phosphonic functional groups, such as vinyl sulfonic acid, vinyl phosphonic acid, allyl sulfonic acid, methyl allyl sulfonic acid, 2-methylenepropane-1,3-disulfonic acid, 2-sulfoethyl methacrylate, sulfopropyl methacrylate, sulfopropyl acrylate, allyl phosphonic acid, styrene sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (ATBS), and 2-acrylamido-2-methylpropanedisulfonic acid; water-soluble salts of these monomers, such as their alkali metal salts (different from the crystal form of the sodium salt of 2-acrylamido-2-methylpropanesulfonic acid), alkaline earth metal salts, or ammonium salts; and mixtures thereof.

[0093] In a particular embodiment of the invention, the polymer microgel is obtained from at least one monomer that is partially or completely salt-forming.

[0094] Salt formation refers to the substitution of a proton in at least one -R(=O)-OH (where R = P, S, or C) type acid functional group of an anionic monomer with a metal or ammonium cation to form a -R(=O)-OX (X is a metal or cation) type salt. In other words, the non-salting form corresponds to the acid form of the monomer, such as RC(=O)-OH in the case of a carboxylic acid functional group, while the salting form of the monomer corresponds to the form RC(=O)-O-X+, where X+ corresponds to a metal, preferably an alkali metal or an ammonium cation. Salt formation of the acid functional groups of the polymer can be partial or complete.

[0095] Salt formation advantageously corresponds to salts containing alkali metals (Li, Na, K, etc.), alkaline earth metals (Ca, Mg, etc.), or ammonium (e.g., ammonium ions or tertiary ammonium). Preferred salts are sodium salts.

[0096] Salt formation can occur before or after polymerization.

[0097] The polymer microgels advantageously contain 0 mol% to 100 mol% of anionic monomers, preferably 30 mol% to 100 mol%, more preferably 50 mol% to 100 mol%.

[0098] In a particular embodiment of the invention, the polymer microgel advantageously comprises 5 mol% to 100 mol% of anionic monomers in salt-forming form, preferably 10 mol% to 90 mol% and 5 mol% to 50 mol%.

[0099] The cationic monomer is preferably selected from monomers derived from vinyl units (preferably acrylamide, acrylic acid, allyl or maleic acid), which have phosphocation functional groups, or ammonium salts or quaternary ammonium salts.

[0100] More specifically, but not limited to, it includes diallyl dialkylammonium salts, such as diallyl dimethylammonium chloride (DADMAC); acidified or quaternized dialkyl-aminoalkylacrylamide salts; acidified or quaternized dialkylaminoalkylmethylacrylamide salts, for example, methacrylamidopropyltrimethylammonium chloride (MAPTAC), acrylamidopropyltrimethylammonium chloride (APTAC), acidified or quaternized dialkylaminoalkyl acrylate salts, such as quaternized or salt-forming dimethylaminoethyl acrylate (DMAEA), acidified or quaternized dialkylaminoalkyl methacrylate salts, such as quaternized or salt-forming dimethylaminoethyl methacrylate (DMAEMA), and mixtures thereof. The alkyl group is advantageously C1-C3.

[0101] Furthermore, this invention also covers monomers of the DADMAC, APTAC, and MAPTAC types, wherein the counterion is a sulfate, fluoride, bromide, or iodide instead of a chloride.

[0102] The cationic hydrophilic monomer is preferably dimethylaminoethyl acrylate in quaternized form and / or dimethylaminoethyl methacrylate in quaternized form.

[0103] Those skilled in the art know how to prepare quaternized monomers, for example, by using an RX-type quaternizing agent, where R is an alkyl group and X is a halogen or sulfate.

[0104] Quaternizing agents refer to molecules that can alkylate tertiary amines.

[0105] The quaternizing agent can be selected from dialkyl sulfates containing 1 to 6 carbon atoms or alkyl halides containing 1 to 6 carbon atoms. The quaternizing agent is preferably selected from chloromethane, benzyl chloride, dimethyl sulfate or diethyl sulfate.

[0106] The polymer microgels advantageously contain 0 mol% to 100 mol% of cationic monomers, preferably 30 mol% to 100 mol%, and still more preferably 50 mol% to 100 mol%.

[0107] The zwitterionic monomer is preferably selected from derivatives having vinyl units, particularly acrylamide, acrylic acid, allyl or maleic acid types. This monomer preferably contains amine or quaternary ammonium functional groups and carboxylic acid (or carboxylates), sulfonic acid (or sulfonates), or phosphoric acid (or phosphate) type acid functional groups. More specifically, but not limited to, dimethylaminoethyl acrylate derivatives, such as 2-((2-(acryloyloxy)ethyl)dimethylammonium)ethane-1-sulfonate, 3-((2-(acryloyloxy)ethyl)dimethylammonium)propane-1-sulfonate, 4-((2-(acryloyloxy)ethyl)dimethylammonium)butane-1-sulfonate, and [2-(acryloyloxy)ethyl](dimethylammonium)acetate; dimethylaminoethyl methacrylate derivatives, such as 2-((2-(methacryloyloxy)ethyl)dimethylammonium)ethane-1-sulfonate, 3-((2-(methacryloyloxy)ethyl)dimethylammonium)propane-1-sulfonate, 4-(2-(methacryloyloxy)ethyl)dimethylammonium)butane-1-sulfonate, and [2-(methacryloyloxy)ethyl](dimethylammonium)acetate. [3-(3-acryloyloxy)propyl](dimethylammonium)acetate; dimethylaminopropylacrylamide derivatives, such as 2-((3-acryloyloxy)propyl](dimethylammonium)ethane-1-sulfonate, 3-((3-acryloyloxy)propyl](dimethylammonium)propane-1-sulfonate, 4-((3-acryloyloxy)propyl](dimethylammonium)butane-1-sulfonate, [3-(acryloyloxy)propyl](dimethylammonium)acetate, dimethylaminopropylmethacrylamide, 2-((3-methacryloyloxy)propyl](dimethylammonium)ethane-1-sulfonate, 3-(dimethylammonium)propane-1-sulfonate, 4-((3-methacryloyloxy)propyl](dimethylammonium)butane-1-sulfonate, [3-(methacryloyloxy)](dimethylammonium)acetate; and mixtures thereof.

[0108] The applicant has described other zwitterionic monomers in document WO21123599.

[0109] Hydrophobic monomers with a partition coefficient Kow greater than 1.5 can also be used to prepare polymer microgels according to the invention. They are advantageously selected particularly from: esters of (meth)acrylic acid having propoxylated, ethoxylated, or ethoxylated and propoxylated C4-C30 alkyl or aralkyl (alkyl C4-C30, aryl C4-C30) chains; (meth)acrylamide derivatives having C1-C3 alkyl or propoxylated, ethoxylated, or ethoxylated and propoxylated aralkyl (alkyl C4-C30, aryl C4-C30) or dialkyl (alkyl C4-C30) chains; alkyl aryl sulfonates (alkyl C4-C30, aryl C4-C30); or monosubstituted or disubstituted amides of (meth)acrylamide. (I) The following are compounds having propoxylated, ethoxylated, or ethoxylated and propoxylated C4-C30 alkyl or aralkyl (alkyl C4-C30, aryl C4-C30) chains; (meth)acrylamide derivatives having C4-C30 alkyl or propoxylated, ethoxylated, or ethoxylated and propoxylated aralkyl (alkyl C4-C30, aryl C4-C30) or dialkyl (alkyl C4-C30) chains; alkyl aryl sulfonates (alkyl C4-C30, aryl C4-C30); (meth)acrylamide or anionic or cationic monomeric derivatives of acrylic acid carrying hydrophobic chains; and mixtures thereof.

[0110] Hydrophobic monomers can contain halogen atoms, such as chlorine atoms. In these hydrophobic monomers: The alkyl group is preferably C4-C20, more preferably C4-C8. C6-C20 alkyl groups are preferably straight-chain alkyl groups, while C4-C5 alkyl groups are preferably branched-chain alkyl groups. -The aralkyl group is preferably C7-C25, more preferably C7-C15; -The ethoxylated chain preferably comprises 6 to 100 -CH2-CH2-O- groups, more preferably 10 to 40; -The propoxylated chain preferably contains 1 to 50 -CH2-CH2-CH2-O- groups, more preferably 1 to 20.

[0111] Preferred monomers belonging to these categories are, for example: - (meth)hexyl acrylate, (meth)octyl acrylate, octyl (meth)acrylamide, (meth)acrylate lauryl acrylate, lauryl (meth)acrylamide, (meth)acrylate myristyl acrylate, myristyl (meth)acrylamide, (meth)acrylate pentadecyl acrylate, pentadecyl (meth)acrylamide, (meth)acrylate hexadecyl acrylate, hexadecyl (meth)acrylamide, (meth)acrylate oleyl acrylate, oleyl (meth)acrylamide, (meth)acrylate mustard acrylate, mustard (meth)acrylamide, N-tert-butyl (meth)acrylamide, 2-ethylhexyl acrylate, C4-C22 half ester of itaconic acid, acidified or quaternized C4-C22 dialkylaminoalkyl (meth)acrylate, acidified or quaternized C4-C22 dialkylaminoalkyl (meth)acrylamide salt, acrylamido undecanoic acid and combinations thereof; -Cat allyl derivative.

[0112] When a polymer contains one or more hydrophobic monomers, their amounts allow the polymer to remain soluble in water.

[0113] The polymer microgels advantageously contain less than 10 mol% of hydrophobic monomers.

[0114] The polymer microgel preferably does not contain hydrophobic monomers.

[0115] In one particular embodiment, the polymer may contain at least one LCST group. As is common knowledge to those skilled in the art, an LCST group corresponds to a group whose solubility in water at a specific concentration varies with salinity above a certain temperature. This is a group that has a transition temperature induced by heating, defining its lack of affinity for the solvent medium. This lack of affinity manifests as opacity or loss of transparency, which may be due to precipitation, aggregation, gelation, or thickening of the medium. The lowest transition temperature is referred to as the LCST (Lower Critical Solution Temperature). For each concentration of the LCST group, a transition temperature induced by heating is observed. This temperature is greater than the LCST (the lowest point on the curve). Below this temperature, the polymer is soluble in water; above this temperature, the polymer loses its solubility in water.

[0116] In one particular embodiment, the polymer may contain at least one UCST group. As is common knowledge to those skilled in the art, a UCST group corresponds to a group whose solubility in water at a specific concentration varies with salinity below a certain temperature. This is a group that has a transition temperature induced by cooling, defining its lack of affinity for the solvent medium. This lack of affinity manifests as opacity or loss of transparency, which may be due to precipitation, aggregation, gelation, or thickening of the medium. The highest transition temperature is referred to as the UCST (Higher Critical Solution Temperature). For each concentration of the UCST group, a transition temperature induced by cooling is observed. This temperature is less than the UCST (the highest point on the curve). Above this temperature, the polymer is soluble in water; below this temperature, the polymer loses its solubility in water.

[0117] The total amount of monomers is equal to 100 mol%.

[0118] In a preferred embodiment, the polymer microgel comprises at least one cationic monomer and at least one nonionic monomer selected from the above list. According to this embodiment, the polymer microgel advantageously comprises 50 mol% to 100 mol% of a cationic hydrophilic monomer, preferably 60 mol% to 90 mol%, and 0 mol% to 50 mol% of a nonionic hydrophilic monomer, preferably 5 mol% to 50 mol%, still more preferably 5 mol% to 30 mol%.

[0119] According to a second preferred embodiment of the invention, the polymer microgel comprises at least one anionic monomer and optionally at least one nonionic monomer.

[0120] The polymer microgel advantageously comprises 0 mol% to 100 mol% of anionic hydrophilic monomers, preferably 30 mol% to 90 mol%, still more preferably 60 mol% to 90 mol%, and 0 mol% to 50 mol% of anionic hydrophilic monomers in salt-forming form, more preferably 10 mol% to 30 mol%.

[0121] Based on these two aspects, the amounts of various monomers are adjusted by those skilled in the art so as not to exceed 100 mol when preparing polymer microgels.

[0122] Polymer microgels are obtained through free radical polymerization. Free radical polymerization includes polymerization via photochemical (UV or radiation), azo or thermal initiators or redox salts, as well as controlled radical polymerization (CRP) technology.

[0123] Controlled radical polymerization techniques include, but are not limited to, various variants of techniques such as iodine transfer polymerization (ITP), nitride-controlled polymerization (nitride-mediated polymerization, NMP), polymerization controlled by nitrides (nitride-mediated polymerization, NMP), polymerization by atom transfer (atom transfer radical polymerization, ATRP), reversible addition-fragmentation chain transfer (RAFT) (including MADIX (macromolecular design by interchange of xanthates) technology), polymerization with organometallic compounds (organometallic-mediated radical polymerization, OMRP), and radical polymers controlled by heteroatom compounds (organoheteroatom-mediated radical polymerization, OHRP).

[0124] In a preferred embodiment, polymerization is carried out by reversible addition-fracture chain transfer (RAFT) polymerization.

[0125] The polymerization is initiated by a free radical initiator and one or more of the aforementioned hydrophilic and / or hydrophobic monomers, as well as one or more polysaccharides. Examples of free radical initiators include oxidant-reductant pairs, wherein the oxidant is cumene hydroperoxide or tert-butyl hydroperoxide, and the reductant is a persulfate, 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-amidinylpropane) hydrochloride, and peroxide compounds, such as benzoyl peroxide, tert-butyl hydroperoxide, or lauroyl peroxide, may also be used.

[0126] According to one aspect of the invention, at least one additional crosslinking agent may optionally be included in the preparation of the polymer microgel. This additional crosslinking agent is advantageously selected from classical crosslinking agents, particularly from multifunctional agents such as methylene bisacrylamide (MBA), ethylene glycol diacrylate, polyethylene glycol dimethacrylate, diacrylamide, methyl cyanoacrylate, ethylene oxyethyl acrylate, ethylene oxymethacrylate, triallylamine, trimethylolpropane triacrylate (TMPTA), tetraallyl ammonium chloride (TAAC), formaldehyde, glycidaldehyde, glycidyl ethers such as ethylene glycol diglycidyl ether, epoxy compounds, and mixtures thereof.

[0127] This additional crosslinking agent is preferably methylenebisacrylamide (MBA).

[0128] Accordingly, the polymer microgel preferably contains less than 5,000 ppm by weight of a crosslinking agent, particularly a classic crosslinking agent, more preferably 100 ppm to 5,000 ppm by weight of the monomer, more preferably 300 ppm to 3,000 ppm by weight of the monomer, and still more preferably 500 ppm to 1,500 ppm by weight of the monomer.

[0129] Polymer microgels can be obtained using various free radical polymerization techniques known to those skilled in the art. Advantageously, polymer microgels can be obtained via reverse emulsion polymerization or precipitation polymerization.

[0130] Inverse emulsion The thickening composition according to the invention is preferably obtained by reverse emulsion polymerization. The formation of polymer microgels in hydrophilic phase droplets containing monomers leads to the acquisition of polymer microgels.

[0131] This polymerization technique is well known to those skilled in the art. It involves emulsifying a hydrophilic phase comprising one or more monomers and one or more crosslinking agents in a lipophilic phase. This emulsification is carried out using a water-in-oil emulsifier.

[0132] According to the present invention, the polymer microgel is prepared from at least the following compounds in a reverse emulsion: - A hydrophilic phase comprising one or more monomers and at least one naturally derived crosslinking agent, as described above; -Lipophilic phase; - At least one water-in-oil emulsifier; - At least one oil-in-water emulsifier.

[0133] In a preferred embodiment, the thickening composition according to the invention is in the form of an inverse emulsion. It preferably comprises: -Lipophilic phase; - At least one polymer microgel, which is obtained by polymerizing a monomer having at least one degree of olefinic unsaturation in the presence of at least one crosslinking agent of natural origin; - At least one water-in-oil emulsifier; - At least one oil-in-water emulsifier.

[0134] Reverse emulsions contain droplets dispersed in a lipophilic phase (hydrophilic phase).

[0135] In this invention, the term "water-in-oil emulsifier" refers to a compound capable of emulsifying water in oil, and "oil-in-water emulsifier" is a compound capable of emulsifying oil in water. Generally, water-in-oil emulsifiers are considered surfactants with an HLB strictly less than 8, and oil-in-water emulsifiers are surfactants with an HLB greater than or equal to 10. Surfactants with an HLB between 8 and 10 are considered wetting agents. Where necessary, those skilled in the art may refer to the *Handbook of Applied Surface and Colloid Chemistry*, K. Holmberg, Chapter 11.

[0136] The hydrophilic-lipophilic balance (HLB) of a chemical compound is a measure of its hydrophilicity and / or lipophilicity determined by calculating the values ​​of individual segments of the molecule, as described by Griffin, WC (1949) in the classification of surface-active agents by “HLB”, as described in The Journal of the Society of Cosmetic Chemists, 1, 311-326.

[0137] In this invention, the Griffin method, which calculates values ​​based on chemical groups in the molecule, is employed. Griffin specifies a dimensionless number between 0 and 20 to provide information related to solubility in water and oil.

[0138] The HLB value of a substance with a total molecular weight of M and a hydrophilic moiety with a molecular weight of Mh is given by the following equation: [Mathematics 3] HLB = 20 (Mh / M) The lipophilic phase of a reverse emulsion may contain mineral oil, vegetable oil, synthetic oil, or a mixture of two or more of these oils.

[0139] Examples of mineral oils are mineral oils and mixtures thereof containing saturated hydrocarbons of the aliphatic, cycloalkanes, alkanes, isoalkanes, cycloparaffinic or naphthyl type.

[0140] Examples of synthetic oils are hydrogenated polydecenes or hydrogenated polyisobutylenes and esters such as octyl stearate, octyl dodecyl myristate, butyl oleate, cocoyl octanoate / decanoate, diisopropyl adipate, polyhydroxystearate ethylhexyl, isopropyl palmitate, hexyl laurate, ethyl oleate, myristyl palmitate, isostearyl palmitate, propylene glycol dicaprylate, propylene glycol dicaprylate / dicaprylate, and all glyceryl ester derivatives and mixtures thereof.

[0141] Examples of vegetable oils are selected from hydrocarbon oils of plant origin, such as liquid triglycerides of fatty acids containing 4 to 30 carbon atoms, such as heptanoic acid or caprylic acid triglycerides, or, for example, from jojoba, babassu, sunflower, olive, coconut, Brazil nut, marula, corn, soybean, squash, grape seed, sesame, hazelnut, almond, macadamia nut, arara, coriander, castor oil, avocado oil, caprylic / capric acid triglycerides, shea butter; liquid fractions of shea butter, almond oil, blackcurrant seed oil, jojoba oil, sesame oil, macadamia nut oil, sunflower oil, and rosehip oil, and mixtures thereof.

[0142] In a preferred embodiment, the lipophilic phase of the reverse emulsion is selected from coconut oil alcohol-caprylate / decanoate, diisopropyl adipate, poly(ethylhexyl hydroxystearate), isopropyl palmitate, hexyl laurate, ethyl oleate, myristyl myristate, isostearyl palmitate, propylene glycol dicaprylate, propylene glycol dicaprylate / decanoate, and all glyceryl ester derivatives and mixtures thereof. The solvent for the hydrophilic phase of the reverse emulsion is advantageously water.

[0143] Generally, during polymerization, the weight ratio of the hydrophilic phase to the lipophilic phase in the reverse emulsion is preferably between 50 / 50 and 90 / 10, and more preferably between 60 / 40 and 80 / 20.

[0144] At least one water-in-oil emulsifier in the reverse emulsion is advantageously selected from the following list: sorbitol extracts, such as sorbitol monooleate or sorbitol polyoleate, sorbitol isostearate or sorbitol sesquioleate, polyethoxylated sorbitol esters, diethoxylated cetyl alcohol, tetraethoxylated lauryl acrylate, ethylene condensation products of higher fatty alcohols (such as products of the reaction of oleyl alcohol with two ethylene oxide units), condensation products of alkylphenols and ethylene oxide (such as products of the reaction of nonylphenol with four ethylene oxide units), and mixtures thereof. Ethoxylated fatty amines (such as Witcamide® 511) based on betaine and ethoxylated amines and mixtures thereof are also good candidates for emulsifiers.

[0145] Generally, a reverse emulsion contains 1% to 10% by weight of water-in-oil emulsifier relative to the total weight of the reverse emulsion.

[0146] Reverse emulsions may advantageously contain stabilizers. Possible examples include: polyesters with molecular weights between 1,000 g / mol and 3,000 g / mol; condensation products of poly(isobutylene)succinic acid or its anhydrides with polyethylene glycol; and water-soluble block polymers with molecular weights between 2,500 g / mol and 3,500 g / mol, such as water-soluble block polymers sold under the name Hypermer®.

[0147] Generally, the reverse emulsion contains 1% to 10% by weight of stabilizer relative to the total weight of the reverse emulsion.

[0148] The oil-in-water emulsifier is advantageously selected from: ethoxylated nonylphenol, preferably having 4 to 10 degrees of ethoxylation (i.e., the degree of ethoxylation is preferably in the range of 4 to 10); ethoxylated / propoxylated alcohols, preferably having one degree of ethoxylation / propoxylation, comprising 12 to 25 carbon atoms; ethoxylated tridecyl alcohol; ethoxylated / propoxylated fatty alcohols; ethoxylated sorbitan esters (advantageously having 20 molar equivalents of ethylene oxide); polyethoxylated sorbitan lauryl esters (advantageously having 20 molar equivalents of ethylene oxide); polyethoxylated castor oil (advantageously having 40 molar equivalents of ethylene oxide); decaethoxylated oledecyl alcohol; heptaethoxylated lauryl alcohol; polyethoxylated sorbitan monostearate esters (advantageously having 20 molar equivalents of ethylene oxide); The following are included: 0 molar equivalents of ethylene oxide; polyethoxylated alkylphenols (advantageously having 10 molar equivalents of ethylene oxide) cetyl ethers; polyethylene oxide alkyl aryl ethers; N-cetyl-N-ethylmorpholine cation ethyl sulfate; sodium lauryl sulfate; condensation products of fatty alcohols and 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 and 5 molar equivalents or more of ethylene oxide (advantageously 5 to 50 molar equivalents); ethoxylated tristyrylphenol; condensates of ethylene oxide partially esterified with aliphatic chains and polyols and their anhydrous forms; amine oxides advantageously having alkyl polyglucosides; glucamides; phosphate esters; alkylbenzene sulfonic acids and their salts; and water-soluble surfactant polymers. Oil-in-water emulsifiers may also be one or more mixtures of these oil-in-water emulsifiers. The alkyl groups in these oil-in-water emulsifiers advantageously have 1 to 20 carbon atoms, and more advantageously have 3 to 15 carbon atoms in a straight-chain or branched group. Furthermore, the aryl groups in these oil-in-water emulsifiers advantageously contain 6 to 20 carbon atoms, and more advantageously 6 to 12 carbon atoms, and mixtures thereof.

[0149] Reverse emulsions can be partially dehydrated to obtain dehydrated reverse emulsions.

[0150] Therefore, in one aspect of the invention, an inverse emulsion is dehydrated to form a solid, wherein the particles are aggregates of dehydrated microgels, for example, when microgels are obtained by spray drying (polymer spray drying; PSD) of an inverse emulsion containing microgels. Spray drying is a well-known method of particle production that involves converting a fluid material into dry particles using a gaseous thermal drying medium (such as hot gas, air, or nitrogen) in a spray dryer. Available spray dryers are well known to those skilled in the art.

[0151] Generally, the concentration of polymer microgels in the thickening composition obtained by reverse emulsion polymerization is between 10% by weight and 70% by weight, and preferably between 40% by weight and 60% by weight, relative to the total weight of the thickening composition.

[0152] The polymerization of one or more monomers is free radical polymerization. Free radical polymerization includes polymerization carried out by UV, azo, redox, or thermal initiators.

[0153] Precipitation and polymerization According to a second aspect of the invention, the polymer microgel is obtained by precipitation polymerization. Precipitation polymerization in a solvent medium involves the polymerization of monomers soluble in the solvent, while the resulting polymer is itself insoluble and thus precipitates from the solvent. When polymerization is complete, the polymer appears as a precipitate in the reaction medium. Generally, the precipitate is separated, for example, by filtration, and then dried to obtain a powder.

[0154] Suitable solvents can be polar or non-polar.

[0155] Nonpolar solvents include cyclohexane, heptane, benzene, toluene, xylene, ethylbenzene, and straight-chain, branched, or cyclic alkanes having 2 to 20 carbon atoms, dichloromethane, and ethyl acetate.

[0156] The polymer microgels are preferably polymerized by free radical precipitation polymerization in a polar solvent. One polar solvent or a mixture of multiple polar solvents can be used. The mixture of polar solvents preferably contains water and an alcohol or ketone.

[0157] The alcohol or ketone is preferably selected from methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-2-propanol, 1-butanol, 2-butanol, dimethyl ketone, diethyl ketone, pent-2-one, butanone, tetrahydropyran, tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxane, and 1,4-dioxane. The mixture of polar solvents is preferably a mixture of proton solvents (proton donors).

[0158] In a particular embodiment of the invention, the solvent used for precipitation polymerization is preferably an alcohol containing one to four carbons. It is advantageously selected from methanol, ethanol, propanol, isopropanol, tert-butanol, or mixtures thereof. Preferably, only tert-butanol is used as the solvent.

[0159] The mixture of polar solvents preferably contains up to 10% by weight of water, preferably 0.5% to 6% by weight of water, still preferably 1% to 6% by weight of water, and still more preferably 1% to 4% by weight of water.

[0160] According to the invention, polymerization is preferably carried out in the absence of oxygen. Degassing involves removing residual oxygen from the reaction medium. For this purpose, an inert gas is introduced to degas the reaction medium. The inert gas typically passes through the solution. Suitable inert gases for this purpose are, for example, nitrogen or carbon dioxide.

[0161] According to one aspect of the invention, a surfactant is added to stabilize the medium, thereby providing optimal polymerization conditions. The solution may contain at least one surfactant with an HLB (hydrophilic-lipophilic balance) of less than 15, preferably between 9 and 13, to stabilize the solution and improve polymerization. Generally, the amount of said surfactant in the solution is between 0.2% by weight and 20% by weight, preferably from 1% by weight to 10% by weight.

[0162] Surfactants can be nonionic, anionic, cationic, amphoteric, or zwitterionic, and are preferably nonionic. One or more surfactants are preferably selected from ethoxylated surfactants, PEG diacrylates, ethoxylated fatty alcohol ethers, sugar esters or polyols or betaine, esters based on glycerol, diglycerol or triglycerides or other alcohols, such as sugars, such as maltitol or sorbitol, and mixtures thereof. Alkyl polyglucosides are advantageously used.

[0163] According to the present invention, free radical precipitation polymerization is carried out at atmospheric pressure at a temperature between 60°C and 85°C.

[0164] Generally, the concentration of polymer microgels 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.

[0165] According to the present invention, the particle size of the polymer microgel is between 0.01 µm and 100 µm, specifically between 0.05 µm and 50 µm, preferably between 0.5 µm and 20 µm, and still more preferably between 0.5 µm and 10 µm.

[0166] The average size of polymer microgels is the average diameter measured using conventional techniques, employing laser measurement instruments, through laser particle size analysis. These conventional techniques are part of the knowledge of those skilled in the art. The Mastersizer instrument from Malvern can be used for this purpose.

[0167] In this invention, the polymer microgel is structured with at least one crosslinking agent of natural origin, and the weight ratio of the polymer microgel to the crosslinking agent is between 0.1 and 10. Specifically, the weight ratio of the polymer microgel to the crosslinking agent is between 0.1 and 5.0, more specifically between 0.30 and 5; and more preferably between 0.35 and 2.59.

[0168] For the purposes of this invention, it should be understood that the weight of the polymer microgel encompasses the sum of the weight of the monomer and the weight of the naturally sourced crosslinking agent that reacts with the monomer during the polymerization stage.

[0169] When an additional crosslinking agent is used, the additional crosslinking agent is included in the weight of the polymer microgel.

[0170] The weight of unreacted crosslinking agent can be determined by size exclusion chromatography.

[0171] Therefore, the weight ratio of the polymer microgel to the crosslinking agent is the ratio of the sum of the weights of the monomers to the weight of the reacted naturally sourced crosslinking agent, and optionally, the weight of the additional crosslinking agent to the total weight of the naturally sourced crosslinking agent used to prepare the polymer microgel. This weight ratio is between 0.1 and 10.

[0172] Use of the thickening composition according to the invention in thickened formulations The present invention also relates to the use of the thickening compositions according to the invention in thickened formulations of cosmetics or detergents or in the manufacture of textiles.

[0173] The thickening compositions according to the present invention can be used based on the knowledge and practice of formulators of cosmetic compositions, detergents and textile printing pastes.

[0174] In this invention, cosmetic formulations also include dermatological formulations and pharmaceutical formulations. Cosmetic formulations typically contain an aqueous phase. Cosmetic formulations are applied, particularly to the skin or hair, and are typically in the form of an oil-in-water emulsion, and sometimes in the form of a water-in-oil emulsion, to form, for example, creams or lotions. Such compositions can, for example, correspond to anti-aging creams or lotions, aftershave products, moisturizing creams, hair dye lotions, shampoos, conditioners and conditioning shampoos, bath products, cleansing creams or hair care or sunscreen creams or lotions. Creams differ from lotions in that they have a higher viscosity.

[0175] Thickening compositions are widely used in these cosmetic formulations to adapt their sensory characteristics (appearance, application) to consumer requirements, but also to suspend or stabilize active ingredients.

[0176] Thickened detergent formulations are formulations used to clean a variety of surfaces, especially textile fibers, any type of hard surface such as tableware, floors, windows, and surfaces made of wood, metal, or composite materials. For example, such formulations correspond to detergents for washing clothes by hand or in a washing machine, products for cleaning tableware by hand or in a dishwasher, or detergents for cleaning kitchen components, toilets, furniture, floors, and windows, as well as other commonly used cleaning products.

[0177] 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, moisturizers, plant extracts, sunscreens, detergent adjuvants, fluorescent agents, foaming agents or foam inhibitors, neutralizers, pH adjusters, preservatives, fragrances, emulsifying compounds, and colorants, but this list is not limited. Those skilled in the art know how and what ingredients can be used to formulate cosmetic or detergent formulations. For cosmetic formulations, reference may be made to patent application FR 2 979 821, and for detergent compositions, references may be made to documents FR 2 766 838, FR 2 744 131, and EP 0 759 966.

[0178] The thickened formulation advantageously contains 0.1% to 10% by weight of the polymer microgel according to the invention, preferably 0.3% to 7% by weight, and still more preferably 0.5% to 3% by weight, relative to the total weight of the thickened formulation.

[0179] Another subject of the invention relates to a cosmetic or detergent or textile printing paste formulation, which is thickened with at least one thickening composition according to the invention.

[0180] Example The following examples clearly and without limitation provide the best illustration of the advantages of the present invention.

[0181] Use the following abbreviations: HEC indicates hydroxyethyl cellulose. HPG indicates hydroxypropyl guar gum. I. Synthesis of polymer microgels The purpose of the following examples is to illustrate the synthesis of different thickening compositions according to the present invention.

[0182] Example 1: Thickening composition A: Synthesis of polymer microgel P1 via reverse emulsion polymerization 1.1. Preparation of naturally derived crosslinking agent M An aqueous solution was prepared by dispersing 280 g of hydrolyzed starch in 280 g of deionized water. Then, 1.54 g of 30% sodium hydroxide and 1.96 g of methacrylic anhydride were added dropwise. The addition of 30% sodium hydroxide was interrupted before the addition of methacrylic anhydride was completed to allow the pH to be adjusted to between 6.5 and 7.

[0183] 1.2. Aqueous phase The aqueous phase was prepared by mixing acrylic acid (91.93 g), deionized water (23.59 g), methylenebisacrylamide (MBA) (0.46 g), and 0.56 g of the pentasodium salt of diethylenetriaminepentaacetic acid (Versenex® 80).

[0184] The aqueous phase was neutralized with 20.41 g of 50% sodium hydroxide solution.

[0185] The aqueous solution containing the naturally derived crosslinking agent prepared at 1.1 above was added to this aqueous phase. The mixture was kept stirred for 10 minutes to homogenize.

[0186] 1.3. Organic phase The 1 L reactor was charged with octyl dodecyl myristate (171.55 g) and C11-15 isoalkane (Isoalkane), also known as Isopar® J (100.95 g), as a low aromatic hydrocarbon solvent. The main surfactants added were: 5 g of sorbitol ester, such as Span® 80; 10 g of ABA block copolymer emulsifier, such as the ABA block copolymer emulsifier sold under the trade name Hypermer® 6212; and 25 g of stearyl methacrylate / methacrylic acid copolymer.

[0187] Stir the organic phase for 10 minutes to homogenize it.

[0188] 1.4. Emulsion Formation and Polymerization The aqueous phase prepared at 1.2 is added to the reactor containing the organic phase prepared at 1.3 and maintained under stirring.

[0189] The mixture is emulsified and degassed by purging with nitrogen for 30 minutes, and then polymerization is initiated by a combined feed solution of a reducing agent (sodium metabisulfite) and an oxidizing agent (tert-butyl hydroperoxide).

[0190] A rotary agitator is used to subject the emulsion to 80 mbar pressure at 90°C in order to concentrate the emulsion by removing water and Isopar® J.

[0191] After the emulsion is cooled, an inverse alkyl polyglucoside surfactant (10% by weight) is added while stirring.

[0192] This produces an inverse emulsion, thus yielding polymer microgel P1. 。

[0193] Example 2: Thickening composition B: Synthesis of polymer microgel P2 via precipitation polymerization (PPP) In a 1 L jacketed reactor, with an air inlet mounted on the base and equipped with a reflux condenser and thermometer, 450 g of tert-butanol containing 2.5% by mass distilled water was stirred with a crescent-shaped blade. 25 g of guar gum was dispersed in the reactor, and the pH was then adjusted to 9 by ammonia purging. Methacrylic anhydride (0.2 g) was then added, and stirring was maintained for 30 minutes. Subsequently, 2-acrylamido-2-methylpropanesulfonic acid (ATBS, 60 g) was added, and ammonia purging was restarted for another 30 minutes, taking care to keep the pH below 7.

[0194] The reaction mixture was degassed by purging with nitrogen for at least half an hour, then trimethylolpropane triacrylate (TMPTA, 0.86 g) was added, and the mixture was gradually heated to 70°C using a heat conditioning bath. Then, the polymerization initiator (dilauryl peroxide, 0.6 g) was added.

[0195] The polymerization is exothermic and reaches a maximum temperature, at which the mixture is held under reflux for two hours.

[0196] The formation of a white precipitate indicates the efficient synthesis of the hybrid polymer. The solvent was evaporated using a rotary evaporator (90°C, 100 mbar), and the precipitate was recovered and dried at 70°C for 12 hours.

[0197] This produces a composition in powder form. This yields polymer microgel P2.

[0198] Example 3: Thickening composition A': Synthesis of polymer microgel P3 via reverse emulsion polymerization 3.1. Preparation of naturally derived crosslinking agent M An aqueous solution was prepared by dispersing 152 g of hydrolyzed starch in 161 g of deionized water. Then, 0.84 g of 30% sodium hydroxide and 0.68 g of maleic anhydride were added dropwise. The addition of 30% sodium hydroxide was interrupted before the addition of maleic anhydride was completed to allow the pH to be adjusted to between 6.5 and 7.

[0199] 3.2. Aqueous phase An aqueous phase was prepared by mixing a solution of 80% quaternized DMAEA (285 g), deionized water (55.93 g), and methylenebisacrylamide (MBA) (0.17 g).

[0200] The aqueous solution containing the naturally derived crosslinking agent prepared at section 3.1 was added to this aqueous phase. The mixture was kept stirred for 10 minutes to homogenize.

[0201] 3.3. Organic Phase The 1 L reactor was charged with 220 g of coconut oil alcohol-octanoate / caprylate and 55 g of Isopar® J as a low aromatic hydrocarbon solvent. The main surfactants added were: 10 g of sorbitol ester, such as Span® 80; 10 g of sorbitol fatty acid ester ethoxylate, such as Tween® 81; 5 g of ABA copolymer emulsifier, such as Hypermer® 6212; and 22.5 g of stearyl methacrylate / methacrylic acid copolymer.

[0202] Stir the organic phase for 10 minutes to homogenize it.

[0203] 3.4. Emulsion Formation and Polymerization The aqueous phase prepared at step 3.2 is added to the reactor containing the organic phase prepared at step 3.3 and maintained under stirring.

[0204] The mixture is emulsified and degassed by purging with nitrogen for 30 minutes, and then polymerization is initiated by a combined feed solution of a reducing agent (sodium metabisulfite) and an oxidizing agent (tert-butyl hydroperoxide).

[0205] A rotary agitator is used to subject the emulsion to 80 mbar pressure at 90°C in order to concentrate the emulsion by removing water and Isopar® J.

[0206] After the emulsion is cooled, an inverse alkyl polyglucoside surfactant (10% by weight) is added while stirring.

[0207] This will produce an inverse emulsion. This yields polymer microgel P3.

[0208] II. Preparation of thickened formulations comprising the thickening composition according to the invention Example 4: Viscosity of various formulations In this example, the various formulations of the combined crosslinking agent are formulated as follows: - Formulation A contains 3% by weight of thickening composition A obtained according to Example 1 and 97% by weight of water.

[0209] - Formulation A' contains 3% by weight of the thickening composition A' obtained according to Example 3 and 97% by weight of water.

[0210] - Formulation A'' comprises 3% by weight of thickening composition A'' and 97% by weight of water. The thickening composition A'' comprises a polyacrylate microgel structured with a naturally derived crosslinking agent, the microgel being obtained via the method described in Example 1 (reverse emulsion (IEM) method), but with 0.49 g of methacrylic anhydride added at step 1.1 of this method.

[0211] - Formulation B contains 1% by weight of thickening composition B obtained according to Example 2 and 99% by weight of water.

[0212] Table 1 below details the weight ratios and viscosities of the various formulations: [Table 1]

[0213] (1) An internal method based on extracting microgel solutions and quantifying unreacted crosslinking agents by size exclusion chromatography.

[0214] Brookfield viscosity was measured using a Brookfield RVT module viscometer with a rotation speed of 20 rpm.

[0215] Compared to current thickening compositions containing polymer microgels structured with crosslinking agents not derived from natural sources, the compositions according to the present invention allow for formulations with significant alternatives.

[0216] In some cases, comparative results show that viscosity decreases when a naturally sourced crosslinking agent is present. This is due to excessive crosslinking of the formed microgel. This demonstrates the effectiveness of naturally sourced crosslinking agents.

[0217] Example 5: The role of the microgel of the present invention in cosmetic compositions The purpose of this example is to demonstrate the remarkable effects of the microgels of the present invention, obtained by reverse emulsion polymerization, in cosmetic compositions.

[0218] The combination of the product described in Example 1, obtained via reverse emulsion, with polysaccharides was investigated in cosmetic compositions. Hydrogels were prepared at different product concentrations (2% or 3%), and the viscosity (Böhler-Fair RVT, 20 RPM) was measured. The change in viscosity was then evaluated when polysaccharides were introduced into the hydrogels (0.2% polysaccharide in solution for 2% product, or 0.1% polysaccharide in solution for 3% product). The results are summarized in Table 2.

[0219] A synergistic effect was observed between the microgel of the present invention and the subsequently added polysaccharide in the aqueous cosmetic composition. The result was a significant change in viscosity, which was particularly impressive when the polysaccharide was konjac gum.

[0220] Table 2

Claims

1. A thickening composition comprising at least one polymeric microgel, Its features The polymer microgel is structured with at least one naturally derived crosslinking agent, and the weight ratio between the polymer microgel and the naturally derived crosslinking agent is between 0.1 and 10, preferably between 0.30 and 5, and more preferably between 0.35 and 2.

59.

2. The thickening composition according to claim 1, Its features The naturally derived crosslinking agent is partially or entirely derived from biomass or synthetic gas.

3. The thickening composition according to any one of claims 1 or 2, Its features The bio-based carbon content of the naturally sourced crosslinking agent is preferably between 5% by weight and 100% by weight, relative to the total weight of carbon in the crosslinking agent, and the bio-based carbon content is measured according to standard ASTM D6866-21, method B.

4. The thickening composition according to any one of claims 1 to 3, Its features The crosslinking agent comprises at least one polysaccharide chain, the at least one polysaccharide chain being functionalized with at least one monomer reactant, the at least one monomer reactant providing carbon-carbon double bonds to the polysaccharide chain.

5. The thickening composition according to claim 4, Its features The monomer reactants are selected from maleic anhydride, methacrylic anhydride, itaconic anhydride, acid chloride, epoxy chloride, glycidyl methacrylate, glycidyl acrylate, and allyl glycidyl ether.

6. The thickening composition according to any one of claims 4 or 5, Its features The polysaccharide is selected from starch and its derivatives, cellulose and its derivatives, hemicellulose, alginate, pectin, agarose, carrageenan, dextran, pullulan, gelatin, amylose, amylopectin, maltodextrin and natural gums.

7. The thickening composition according to any one of the preceding claims, Its features The degree of substitution of the crosslinking agent is between 10. -4 With 10 -1 between.

8. The thickening composition according to any one of the preceding claims, Its features The weight-average molecular weight of the crosslinking agent is between 100 Da and 1,000,000 Da.

9. The thickening composition according to any one of the preceding claims, Its features The polymer microgel contains at least one hydrophilic monomer, and the at least one hydrophilic monomer contains at least one unsaturated olefinic functional group selected from nonionic and / or anionic and / or cationic functional groups.

10. The thickening composition according to any one of the preceding claims, Its features The polymer microgel contains at least one hydrophilic monomer, which contains at least one unsaturated olefinic functional group selected from the following: acrylamide, acrylic acid, oligomers of acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid (ATBS) and / or its salts, N-vinylformamide (NVF), N-vinylpyrrolidone (NVP), dimethyl diallyl ammonium chloride (DADMAC), quaternized dimethylaminoethyl acrylate (DMAEA), and quaternized dimethylaminoethyl methacrylate (DMAEMA).

11. The thickening composition according to any one of the preceding claims, Its features The particle size of the polymer microgel is between 0.05 µm and 50 µm.

12. The thickening composition according to any one of the preceding claims, Its features The composition comprises 10% to 100% by weight of polymer microgel.

13. Use of a thickening composition according to any one of claims 1 to 12, for use in the manufacture of thickened formulations of cosmetics or detergents or textiles.

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

15. A polymer microgel obtained by free radical polymerization of at least one monomer and structured with at least one crosslinking agent of natural origin, said at least one monomer comprising at least one unsaturated olefinic functional group selected from nonionic and / or anionic and / or cationic functional groups.

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