Inverse latex for a cosmetic composition, comprising a specific polyvalent chelating agent and a polyelectrolyte combining strong acid functional groups and neutral functional groups

Abstract

The present invention relates to a self-reversible inverse latex having an aqueous phase, the aqueous phase comprising: a) a crosslinked anionic polyelectrolyte (P) consisting of: - at least a first monomer unit derived from 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid in free acid or partially or fully salified acid form; and - at least a second monomer unit derived from a monomer of at least one element selected from the group consisting of 2-hydroxyethyl acrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2,3-dihydroxypropyl methacrylate, or vinylpyrrolidone; and - at least a monomer unit derived from a polyene crosslinking monomer (AR); b) a polyvalent chelating compound (SQ) of at least one element selected from the group consisting of: ethylenediamine disuccinic acid in trisodium salt form, tetrasodium salt of glutamic acid N,N-diacetic acid, or sodium salt of iminosuccinic acid.

Description

[0001] The present invention relates to self-reversible inverse latexes comprising novel multivalent chelating agents, to methods for preparing such self-reversible inverse latexes, to the use of said self-reversible inverse latexes as thickeners and / or emulsifiers and / or stabilizers for preparing cosmetic or pharmaceutical compositions for topical use, and also to said compositions thus prepared.

[0002] Polymers are currently widely used in cosmetic formulations for topical use and represent the second most widely used product family in this type of formulation. Cosmetic compositions contain polar phases, such as phases consisting of water, and in most cases it is necessary to use rheology-modifying polymers to increase the viscosity of these polar phases and also to impart a well-defined rheological behavior.

[0003] Among the polymers that modify the rheology of polar phases, mention may be made of natural or synthetic polymers, and in particular linear or branched, crosslinked or non-crosslinked, anionic or cationic or amphoteric polyelectrolyte-type polymers. Once introduced into the polar phase, these polymers exhibit the property of unfolding under the action of electrostatic repulsion due to the presence of (negative and / or positive) charges on the linear or branched, non-crosslinked or crosslinked polymer backbone. The rheology modifiers provide both an increase in the viscosity of the polar phase and an increase in the consistency and / or stabilizing action imparted to the cosmetic, dermatological cosmetic or dermatological pharmaceutical formulation to be thickened.

[0004] In order to meet the needs of consumers and improve cosmetic formulations for topical use, scientists have developed new, innovative and diverse polymer systems. Thus, polymers used in cosmetics for topical use or in dermatological cosmetics can act as film formers, rheology modifiers, making it possible to stabilize the fatty phase in an emulsion (oil-in-water or water-in-oil) or to stabilize particles (pigments or fillers), or to impart specific sensory properties (such as a soft touch, ease of handling and application, a refreshing effect, etc.) after application to the skin, and also have a direct impact on the appearance of the formulation (translucent or opaque).

[0005] Polymers (mainly polyelectrolytes) that modify the rheology of the aqueous phase are produced by the free radical polymerization of monomers of the (meth)acrylate type (i.e., esters derived from acrylic acid or methacrylic acid) or derivatives of acrylamide.

[0006] Today, these polymers, which can be provided in the form of inverse latexes, concentrated inverse latexes or powders, make it possible to meet the needs of consumers in terms of thickening properties in polar solvents such as water. Once these polymers are dispersed in water, the aqueous gels obtained exhibit a smooth appearance, without particles or lumps, with specific tactile properties and ease of handling and application.

[0007] A composition provided in the form of a liquid (referred to as "self-reversible inverse latex") or a concentrated liquid form thereof is provided in the form of a water-in-oil emulsion and comprises:

[0008] - An aqueous phase which itself comprises at least one polyelectrolyte-type, anionic, or cationic, or amphoteric polymer, which polymer is linear and / or branched and / or crosslinked,

[0009] - A fatty phase which comprises at least one oil,

[0010] - At least one water-in-oil emulsifying surfactant (S1),

[0011] - At least one oil-in-water emulsifying surfactant (S2),

[0012] The polymer is obtained by using a reverse emulsion radical polymerization method.

[0013] Free radical polymerization is known for its sensitivity to the presence of impurities, even in small amounts. Compounds that can cause a decrease in the polymerization rate at low concentrations are called inhibitors or retarders. However, the distinction between these two effects is not always straightforward, and the same compound may have two detrimental contributions, depending on its concentration in the medium or the nature of the monomers and the reaction medium. It is necessary to ensure the reproducible properties of the polymers that thicken the aqueous phase in order to ensure the consistent quality of cosmetic formulations for cosmetic use containing these polymers. To this end, industrial manufacturers must ensure that the polymerization reaction repeatedly follows the same kinetics, more particularly with regard to the inhibition time over time, the reaction exothermicity (°C / min), and the total duration of the polymerization reaction. Taking these limitations into account, particular attention is paid to factors that may affect the initiation of the free radical polymerization reaction, such as the presence of oxygen, which can retard the polymerization reaction by reacting with the generated radicals. These new peroxide radicals exhibit lower reactivity and reduced initiating ability. This results in a weaker initiation stage and a lower propagation rate, and thus ultimately produces polymers with different thickening properties. Therefore, a deoxygenation stage of the medium (particularly by purging with nitrogen) proves necessary before the start of the polymerization reaction.

[0014] Another factor that directly affects the polymerization is the presence of metal entities (Fe 2+ 、Fe 3+ 、Cu 2+ etc.), which in turn have an inhibitory effect. In this case, during the initiation stage, inhibition may occur through the reaction of the initiator radicals with the metal impurities, such that the active radical centers then become unable to fix another monomer unit and become inactivated during the polymerization.

[0015] The above metal ions can potentially originate from the starting materials or components of the equipment.

[0016] The monomers used for preparing self-reversible inverse latexes may exhibit trace amounts of metal cations. Similarly, it is not unthinkable that metal contaminants are present in the parts of the industrial equipment where the polymerization reaction is carried out. In most cases, the parts of the equipment are made of stainless steel, and several types of stainless steels with different compositions are encountered. Stainless steel is an iron-based alloy, to which nickel, chromium or molybdenum is added in certain cases. Chromium imparts antioxidant properties to stainless steel because in the presence of oxygen it is able to regenerate its surface chromium oxide layer, called the passivation layer, by itself.

[0017] However, it is not impossible that, upon prolonged contact with sources of pollution, acids, humidity, sea spray or iron-containing dust, or in the case of deep scratches, the protective layer will then become depassivated (and thus activated) and the stainless steel will oxidize faster than it can protect itself. In these cases, the appearance of rust can be observed, and thus the rust is a source of iron-based metal contaminants.

[0018] Given the risks associated with the presence of all these sources of metal contaminants, the use of polyvalent chelating agents is inevitable. The product commonly used is pentasodium diethylenetriaminepentaacetate (also known under the trade name Versenex TM 80).

[0019] However, the change in the European regulations regarding the classification of pentasodium diethylenetriaminepentaacetate has led to the search for an alternative solution as a polyvalent chelating agent for preparing self-reversible inverse latexes.

[0020] From this, the problem that arises is to provide a novel inverse latex with a novel polyvalent chelating agent that is as effective as pentasodium diethylenetriaminepentaacetate but exhibits characteristics that are more in line with the regulatory changes.

[0021] The solution of the present invention is a self-reversible inverse latex that comprises an aqueous phase, which aqueous phase comprises:

[0022] a) a crosslinked anionic polyelectrolyte (P), which consists of:

[0023] - at least one first monomer unit derived from 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid in free acid or partially or fully salted form; and

[0024] - at least one second monomer unit derived from a monomer of at least one element selected from the group consisting of 2-hydroxyethyl acrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2,3-dihydroxypropyl methacrylate and vinylpyrrolidone; and

[0025] - at least one monomer unit derived from a polyene crosslinking monomer (AR);

[0026] b) a polyvalent chelating compound (SQ) of at least one element selected from the group consisting of: disodium ethylenediamine disuccinate in the trisodium salt form, tetrasodium glutamate N,N-diacetate, and sodium salt of iminosuccinic acid.

[0027] Depending on the circumstances, the self-reversible inverse latex according to the present invention may exhibit one or more of the following characteristics:

[0028] - The polyvalent chelating agent (SQ) is disodium ethylenediamine disuccinate in the trisodium salt form;

[0029] - The aqueous phase contains at least 0.01 mol% of the polyvalent chelating agent (SQ), and more particularly at least 0.01 mol% of disodium ethylenediamine disuccinate in the trisodium salt form;

[0030] - The polyene crosslinking monomer (AR) is selected from methylenebis(acrylamide), ethylene glycol dimethacrylate, diethylene glycol diacrylate, ethylene glycol diacrylate, diallylurea, triallylamine, trimethylolpropane triacrylate, diallyloxyacetic acid or one of its salts such as sodium diallyloxyacetate, or a mixture of these compounds;

[0031] - The crosslinking monomer (AR) is methylenebis(acrylamide) or triallylamine;

[0032] - The crosslinked anionic polyelectrolyte contains per 100 mol%:

[0033] · Monomer units produced from 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid in a proportion by weight between 10% and 95%, more particularly between 20% and 90%, and still more particularly between 32% and 80%, in the free acid or partially or fully salted form;

[0034] · Monomer units produced from at least one monomer selected from the group consisting of 2-hydroxyethyl acrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2,3-dihydroxypropyl methacrylate, and vinylpyrrolidone in a proportion by weight between 5% and 90%, more particularly between 10% and 80%, and still more particularly between 20% and 68%; and

[0035] · A molar proportion greater than 0 mol% and less than or equal to 1 mol%, more particularly less than or equal to 0.5 mol%, more particularly less than or equal to 0.25 mol% and very particularly less than or equal to 0.1 mol%, and more particularly greater than or equal to 0.005 mol% of monomer units produced from at least one polyene crosslinking monomer (AR).

[0036] Within the meaning of the present invention, the crosslinked anionic polyelectrolyte (P) represents, for the polymer (P), a non-linear polyelectrolyte which is provided in the form of a three-dimensional network, is insoluble in water but can swell in water and then leads to the formation of a chemical gel.

[0037] Within the meaning of the present invention, the term "salification" indicates that the acid functional groups present in the monomers are in the anionic form and are combined with cations to form a salt form, in particular an alkali metal salt such as sodium or potassium cations, or cations such as those of nitrogenous bases such as ammonium salts, lysine salts or monoethanolamine salts (HOCH2-CH2-NH3 + ). They are preferably sodium salts or ammonium salts.

[0038] According to a specific aspect of the present invention, the self-reversible inverse latex as defined above contains from 20% to 90% by weight, and more particularly from 30% to 90% by weight, more particularly from 30% to 80% by weight, and even more particularly from 33% to 80% by weight of the crosslinked anionic polyelectrolyte (P).

[0039] According to another specific aspect of the present invention, the molar proportion of monomer units resulting from 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid in the free acid or partially or fully salified form present in the crosslinked anionic polyelectrolyte (P) is greater than or equal to 32 mol% and less than or equal to 100 mol%, more particularly greater than or equal to 40 mol% and less than or equal to 100 mol%.

[0040] According to a specific aspect of the present invention, 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid is in the form of a sodium salt or an ammonium salt.

[0041] Another subject of the present invention is a method for preparing an inverse latex as defined above, the method comprising the following stages:

[0042] a) preparing an aqueous phase as defined above,

[0043] b) preparing an organic phase comprising at least one oil (O) and a water-in-oil emulsifying surfactant (S1) system,

[0044] c) mixing and emulsifying the aqueous phase prepared in stage a) and the organic phase prepared in stage b) to form an emulsion,

[0045] d) inertizing the emulsion with nitrogen,

[0046] e) initiating a polymerization reaction by introducing a radical initiator into the inertized emulsion, and

[0047] f) At a temperature between 30 °C and 60 °C, an oil-in-water emulsifying surfactant (S2) system is introduced into the reaction medium resulting from stage e).

[0048] Depending on the circumstances, the process according to the invention may exhibit one or more of the following characteristics:

[0049] - In stage e), the radical initiator is a redox pair that generates bisulfite (HSO3−) ions, such as the cumene hydroperoxide / sodium metabisulfite (Na2S2O5) pair or the cumene hydroperoxide / thionyl chloride (SOCl2) pair;

[0050] - In stage e), a polymerization co-initiator, preferably azobis(isobutyronitrile), is introduced into the inertized emulsion;

[0051] - In stage a), the pH of the aqueous phase is adjusted to between 3.0 and 7.0, more particularly between 3.5 and 6.5, and even more particularly between 4.0 and 6.5;

[0052] - Before carrying out stage f), the reaction medium resulting from stage e) is concentrated by distillation;

[0053] - Spray-drying the reaction medium resulting from stage e) or f).

[0054] In the definition of the self-reversible inverse latex, the oil (O) particularly denotes:

[0055] - Straight-chain alkanes containing from 11 to 19 carbon atoms;

[0056] - Branched-chain alkanes containing from 7 to 40 carbon atoms, such as isododecane, isopentadecane, isohexadecane, is heptadecane, isooctadecane, isononadecane or isoeicosane, or mixtures of some of them, such as those mentioned below and identified by their INCI names: C 7-8 Isoparaffin, C 8-9 Isoparaffin, C 9-11 Isoparaffin, C 9-12 Isoparaffin, C 9-13 Isoparaffin, C 9-14 Isoparaffin, C 9-16 Isoparaffin, C 10-11 Isoparaffin, C 10-12 Isoparaffin, C 10-13 Isoparaffin, C 11-12 Isoparaffin, C 11-13 Isoparaffin, C 11-14 Isoparaffin, C 12-14 Isoparaffin, C 12-20 Isoparaffin, C 13-14 Isoparaffin, C 13-16Isoparaffin;

[0057] - Cycloalkane optionally substituted by one or more linear or branched alkyl groups;

[0058] - White mineral oil, such as those sold under the names: Marcol TM 52, Marcol TM 82, Drakeol TM 6VR, Eolane TM 130, Eolane TM 150;

[0059] - Squalane (or 2,6,10 - trimethyldodecane; CAS No.: 3891 - 98 - 3), Squalene (or 2,6,10,15,19,23 - hexamethyltetracosane), Hydrogenated polyisobutene or Hydrogenated polydecene;

[0060] - Mixture of alkanes containing from 15 to 19 carbon atoms, said alkanes being linear alkanes, branched alkanes and cycloalkanes, and more particularly mixture (M1), which contains, per 100% of its weight, a weight proportion of branched alkanes greater than or equal to 90% and less than or equal to 100%; a weight proportion of linear alkanes greater than or equal to 0% and less than or equal to 9%, and more particularly less than 5%; and a weight proportion of cycloalkanes greater than or equal to 0% and less than or equal to 1%, such as the mixture sold under the name Emogrecn TM L15 or Emogreen TM L19;

[0061] - Fatty alcohol ethers of formula (IV):

[0062] - Z1 - O - Z2 (IV),

[0063] wherein Z1 and Z2, which may be the same or different, represent linear or branched alkyl groups containing from 5 to 18 carbon atoms, such as dioctyl ether, didecyl ether, di - dodecyl ether, dodecyl octyl ether, di - hexadecyl ether, 1,3 - dimethylbutyl tetradecyl ether, 1,3 - dimethylbutyl hexadecyl ether, bis(1,3 - dimethylbutyl) ether or dihexyl ether;

[0064] - Monoesters of fatty acids and alcohols of formula (V):

[0065] - R′1 - (C = O) - O - R′2 (V),

[0066] wherein R′1-(C=O) represents a saturated or unsaturated, straight-chain or branched acyl group containing from 8 to 24 carbon atoms, and R′2, independently of R′1, represents a saturated or unsaturated, straight-chain or branched hydrocarbon chain containing from 1 to 24 carbon atoms, such as methyl laurate, ethyl laurate, propyl laurate, isopropyl laurate, butyl laurate, 2-butyl laurate, hexyl laurate, methyl cocoate, ethyl cocoate, propyl cocoate, isopropyl cocoate, butyl cocoate, 2-butyl cocoate, hexyl cocoate, methyl myristate, ethyl myristate, propyl myristate, isopropyl myristate, butyl myristate, 2-butyl myristate, hexyl myristate, octyl myristate, methyl palmitate, ethyl palmitate, propyl palmitate, isopropyl palmitate, butyl palmitate, 2-butyl palmitate, hexyl palmitate, octyl palmitate, methyl oleate, ethyl oleate, propyl oleate, isopropyl oleate, butyl oleate, 2-butyl oleate, hexyl oleate, octyl oleate, methyl stearate, ethyl stearate, propyl stearate, isopropyl stearate, butyl stearate, 2-butyl stearate, hexyl stearate, octyl stearate, methyl isostearate, ethyl isostearate, propyl isostearate, isopropyl isostearate, butyl isostearate, 2-butyl isostearate, hexyl isostearate or isooctyl isostearate;

[0067] - Diesters of fatty acids and glycerol of formula (VI) and formula (VII):

[0068] R′3-(C=O)-O-CH2-CH(OH)-CH2-O-(C=O)-R′4 (VI)

[0069] R′5-(C=O)-O-CH2-CH[O-(C=O)-R′6]-CH2-OH (VII),

[0070] In formula (VI) and (VII), R′3-(C=O), R′4-(C=O), R′5-(C=O) and R′6-(C=O), which may be the same or different, represent saturated or unsaturated, straight-chain or branched acyl groups containing from 8 to 24 carbon atoms;

[0071] - Triesters of fatty acids and glycerol of formula (VIII):

[0072] R′7-(C=O)-O-CH2-CH[O-(C=O)-R′8]-CH2-O-(C=O)-R′9 (VIII),

[0073] wherein, R′7-(C=O), R′8-(C=O) and R′9-(C=O), which may be the same or different, represent straight-chain or branched, saturated or unsaturated acyl groups containing from 8 to 24 carbon atoms.

[0074] According to another specific aspect of the present invention, the oil (O) is selected from undecane, tridecane, isododecane or isocetane, mixtures of paraffins and isoparaffins and naphthenes, such as the mixture (M1) as defined above and mixtures sold under the name Emogreen TM L15, Emogreen TM L19, Emosmart TM L15, Emosmart TM L19, Emosmart TM V21, Isopar TM L or Isopar TM mixtures sold under the name Marcol TM 52, Marcol TM 82, Drakeol TM 6VR, Eolane TM 130 or Eolane TM white mineral oils sold under the name Marcol 52, Marcol 82, Drakeol 6VR, Eolane 130 or Eolane 150; squalane, squalene, hydrogenated polyisobutene or hydrogenated polydecene; dioctyl ether or didecyl ether; isopropyl myristate, hexyl palmitate, octyl palmitate, isostearyl isostearate, octanoyl / decanoyl triglyceride, hexadecanoyl / octadecanoyl triglyceride or triglycerides derived from rapeseed oil, sunflower oil, linseed oil or palm oil.

[0075] In the water-in-oil self-reversible inverse latex which is the subject of the present invention, the water-in-oil emulsifying surfactant (S1) system consists of a single emulsifying surfactant or a mixture of emulsifying surfactants, provided that the resulting emulsifying (S1) system has a sufficiently low HLB value to cause the formation of a water-in-oil emulsion.

[0076] Examples of water-in-oil emulsifying surfactants (S1) include esters of anhydrohexitols with saturated or unsaturated, straight-chain or branched aliphatic carboxylic acids containing from 12 to 22 carbon atoms optionally substituted by one or more hydroxyl groups, and more particularly esters of anhydrohexitols selected from sorbitan and mannitol with saturated or unsaturated, straight-chain or branched aliphatic carboxylic acids containing from 12 to 22 carbon atoms optionally substituted by one or more hydroxyl groups.

[0077] According to another specific aspect of the present invention, the water-in-oil emulsifying surfactant (S1) system is selected from the elements of the group consisting of: sorbitan laurate, such as those sold under the name Montane TM 20, sorbitan palmitate, such as those sold under the name Montane TM 40, sorbitan stearate, such as those sold under the name MontaneTM those sold at 60, sorbitan oleates, such as those sold under the name Montane TM those sold at 80, sorbitan sesquioleates, such as those sold under the name Montane TM those sold at 85, sorbitan trioleates, such as those sold under the name Montane TM those sold at 83, sorbitan isolaureates, sorbitan isostearates, such as those sold under the name Montane TM those sold at 70, mannitol monolaurates, mannitol monooleates, or mixtures of these esters; polyesters having a molecular weight between 1000 and 3000 and produced by the condensation between poly(isobutenyl) succinic acid or its anhydride, such as Hypermer TM 2296, or under the trade name Simaline TM mixtures sold as IE 501 A, polyglycol polyhydroxystearates of formula (IX):

[0078] [Chemical Formula 1]

[0079]

[0080] In formula (IX), y2 represents an integer greater than or equal to 2 and less than or equal to 50, Z4 represents a hydrogen atom, a methyl group or an ethyl group, and Z3 represents a group of formula (X):

[0081] [Chemical Formula 2]

[0082]

[0083] In formula (X), y′2 represents an integer greater than or equal to 0 and less than or equal to 10, more particularly greater than or equal to 1 and less than or equal to 10, and Z′3 represents: a group of formula (X) as defined above, where Z′3 is the same as or different from Z3; or a hydrogen atom.

[0084] Examples of water-in-oil emulsifying surfactants of formula (IX) that can be used for preparing an emulsifying surfactant (S1) system include PEG-30 dimer hydroxystearates sold under the name Simaline TM WO, or mixtures containing PEG-30 dimer hydroxystearates and sold under the name Simaline TM IE 201 A and Simaline TM mixtures sold as IE 201 B, or mixtures containing trimethylolpropane-30 trimer hydroxystearates sold under the name Simaline TM mixtures sold as IE 301 B.

[0085] According to a specific aspect of the present invention, the oil-in-water emulsion system (S2) contains, per 100% of its weight, a proportion of composition (Ce) greater than or equal to 50% by weight and less than or equal to 100% by weight, and the composition (Ce) contains, per 100% of its weight:

[0086] - at least one compound of formula (I) from 10% to 60% by weight, more particularly from 15% to 60% by weight, and very particularly from 15% to 50% by weight:

[0087] HO-[CH2-CH(OH)-CH2-O] n -H (I)

[0088] where n represents an integer greater than or equal to 1 and less than or equal to 15;

[0089] - at least one compound of formula (II) from 40% to 90% by weight, more particularly from 40% to 85% by weight, and very particularly from 50% to 85% by weight:

[0090] R1-(C=O)-[O-CH2-CH(OH)-CH2] p -OH (II),

[0091] where p, different or identical to n, represents an integer greater than or equal to 1 and less than or equal to 15; and where the R1-(C=O)- group represents a saturated or unsaturated, straight-chain or branched aliphatic group containing from 6 to 22 carbon atoms; and optionally

[0092] - up to 30% by weight, more particularly from 0% to 25% by weight, and very particularly from 0% to 20% by weight, of at least one composition (C 11 ) represented by formula (III):

[0093] HO-[CH2-CHOH-CH2-O-] q -(G) r -H (III),

[0094] where q, different or identical to n, represents an integer greater than or equal to 1 and less than or equal to 3, G represents a residue of a reducing sugar and r represents a decimal greater than or equal to 1.05 and less than or equal to 5.00,

[0095] said composition (C 11 ) consists of a mixture of compounds of formula (III1), (III2), (III3), (III4) and (III5):

[0096] HO-[CH2-CHOH-CH2-O-] q -O-(G)1-H (III1),

[0097] HO-[CH2-CHOH-CH2-O-] q -O-(G)2-H (III2),

[0098] HO-[CH2-CHOH-CH2-O-] q -O-(G)3-H (III3),

[0099] HO-[CH2-CHOH-CH2-O-] q -O-(G)4-H (III4),

[0100] HO-[CH2-CHOH-CH2-O-] q -O-(G)5-H (III5),

[0101] The molar ratios of the compounds of formulae (III1), (III2), (III3), (III4) and (III5) are respectively equal to a1, a2, a3, a4 and a5, such that the sum (a1 + a2 + a3 + a4 + a5) is equal to 1, and such that the sum (a1 + 2a2 + 3a3 + 4a4 + 5a5) is equal to r.

[0102] The oil-in-water emulsifying surfactant (S2) system consists of the sole composition (Ce) or a mixture of said composition (Ce) with one or more other emulsifying surfactants, provided that the resulting emulsifying surfactant (S2) system has a sufficiently high HLB value to cause the formation of an oil-in-water emulsion.

[0103] In formula (III) as defined above, the reducing sugar represents a sugar derivative that does not exhibit, in its structure, a glycosidic bond established between the anomeric carbon and the oxygen of the acetal group, as defined in the following reference publication: "Biochemistry", Daniel Voet / Judith G. Voet, page 250, John Wiley & Sons, 1990. The oligomeric structure (G)x can exist in any isomeric form, whether it involves optical isomerism, geometric isomerism or positional isomerism; it can also represent a mixture of isomers.

[0104] Regarding the polymerization reaction, it is initiated at a preferred temperature of 10 °C in stage e) and then proceeds quasi-adiabatically until a temperature of 50 °C or higher, or is carried out by controlling the temperature.

[0105] Another subject of the invention is the use of the self-reversible inverse latex as defined above as a thickening agent and / or emulsifying agent and / or stabilizing agent in a composition for topical use (cosmetic or pharmaceutical).

[0106] Another subject of the invention is a topical cosmetic composition (F) or a topical pharmaceutical composition (G), characterized in that the topical cosmetic composition (F) or the topical pharmaceutical composition (G) per 100% of its total weight comprises, as a thickening agent, from 0.1% to 10% by weight of the self-reversible inverse latex as defined above.

[0107] The expression "for topical use" used in the definition of the compositions (F) and (G) means that they are used by application to the skin, hair, scalp or mucous membranes, whether it involves direct application in the case of cosmetics, dermatological cosmetics, dermatological pharmaceuticals or pharmaceutical preparations, or indirect application, for example, in the case of body care products in the form of textile or paper wipes or hygiene products intended to come into contact with the skin or mucous membranes.

[0108] The compositions (F) and (G) are generally provided in the form of an aqueous solution or a water / alcohol solution or a water / diol solution, in the form of a suspension, an emulsion, a microemulsion or a nanoemulsion, regardless of whether they have a water-in-oil, oil-in-water, water-in-oil-in-water or oil-in-water-in-oil type.

[0109] The compositions (F) and (G) can be packaged in a bottle, in a device of the "pump spray" type, in a pressurized form in an aerosol device, in a device equipped with a perforated wall (such as a grille) or in a device equipped with a ball applicator (called a "roller").

[0110] Generally, the compositions (F) and (G) also contain excipients and / or active ingredients customarily used in the field of formulations for topical use (especially cosmetic, dermatological cosmetic, pharmaceutical or dermatological pharmaceutical formulations), such as thickening and / or gelling surfactants, stabilizing agents, film-forming compounds, hydrotropes, plasticizers, emulsifying agents and co-emulsifying agents, opacifiers, pearlescent agents, emollients, polyvalent chelating agents, chelating agents, antioxidants, fragrances, preservatives, conditioning agents, whitening agents intended for bleaching body hair and skin, active ingredients intended to contribute to the treatment effect on the skin or hair, sunscreens, pigments or inorganic fillers, particles providing a visual effect or intended for encapsulating active ingredients, exfoliating particles, or texture agents.

[0111] Examples of foaming and / or detergent surfactants that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include anionic, cationic, amphoteric or non-ionic foaming and / or detergent surfactants.

[0112] The foaming and / or detergent anionic surfactants which can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts or amino alcohol salts of alkyl ether sulfates, alkyl sulfates, alkylamido ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates, α-olefin sulfonates, alkane sulfonates, alkyl phosphates, alkyl ether phosphates, alkyl sulfonates, alkylamido sulfonates, alkylaryl sulfonates, alkyl carboxylates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylamido sulfosuccinates, alkyl sulfacetates, alkyl sarcosinates, acyl hydroxyethyl sulfonates, N-acyl taurates, acyl lactates, N-acylated derivatives of amino acids, N-acylated derivatives of peptides, N-acylated derivatives of proteins or N-acylated derivatives of fatty acids.

[0113] The foaming and / or detergent amphoteric surfactants which can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include alkyl betaines, alkylamido betaines, sulfobetaines, alkylamidoalkyl sulfobetaines, imidazoline derivatives, phosphate betaines, amphoteric polyacetates and amphoteric propionates.

[0114] The foaming and / or detergent cationic surfactants which can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) particularly include quaternary ammonium derivatives.

[0115] The foaming and / or detergent nonionic surfactants which can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) more particularly include alkyl polyglycosides containing straight-chain or branched and saturated or unsaturated aliphatic groups and containing from 8 to 16 carbon atoms, such as octyl polyglucoside, decyl polyglucoside, undecyl polyglucoside, dodecyl polyglucoside, tetradecyl polyglucoside, hexadecyl polyglucoside or 1,12-dodecanediyl polyglucoside; ethoxylated hydrogenated castor oil derivatives, such as the product sold under the INCI name "PEG-40 hydrogenated castor oil"; polysorbates, such as polysorbate 20, polysorbate 40, polysorbate 60, polysorbate 70, polysorbate 80 or polysorbate 85; coconut amide; or N-alkylamines.

[0116] Examples of the thickening and / or gelling surfactants which can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include optionally alkoxylated alkyl polyglycoside fatty esters, such as ethoxylated methyl polyglucoside esters, for example the products sold under the names Glucamate TM LT and Glucamate TMPEG 120 methyl glucoside trioleate and PEG120 methyl glucoside dioleate sold by DOE-120; alkoxylated fatty esters, such as those sold under the name Crothix TM PEG 150 pentaerythritol tetrastearate sold by DS53, or those sold under the name Antil TM PEG 55 propylene glycol oleate sold by TM ; aliphatic chain polyalkylene glycol carbamates, such as those sold under the name Elfacos TM PPG-14 lauryl ether isophorone dicarbamate sold by T211, or those sold under the name Elfacos TM PPG-14 palm kernel oil ether-60 hexyl dicarbamate sold by GT2125.

[0117] Examples of thickeners and / or gelling agents that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include copolymers of AMPS and alkyl acrylates, the carbon chain of the alkyl acrylate containing between 4 and 30 carbon atoms, and more particularly between 10 and 30 carbon atoms; linear, branched or crosslinked terpolymers of at least one monomer having free, partially or fully salified strong acid functional groups with at least one neutral monomer and at least one monomer of formula (XIII):

[0118] CH2=C(R′3)-C(=O)-[CH2-CH2-O] n′ -R′4 (XIII)

[0119] wherein R′3 represents a hydrogen atom or a methyl group, R′4 represents a linear or branched alkyl group containing from 8 to 30 carbon atoms, and n′ represents a number greater than or equal to 1 and less than or equal to 50.

[0120] Examples of thickeners and / or gelling agents that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include polysaccharides consisting only of monosaccharides, such as dextran or glucose homopolymers, glucomannan dextran, xyloglucan, galactomannan, the degree of substitution (DS) of D-galactose units on the main D-mannose chain of which is between 0 and 1, and more particularly between 1 and 0.25, such as galactomannans derived from cassia gum (DS = 1 / 5), locust bean gum (DS = 1 / 4), tara gum (DS = 1 / 3), guar gum (DS = 1 / 2) or fenugreek gum (DS = 1).

[0121] Examples of thickeners and / or gelling agents that may be combined with the self-inverting inverse latex as defined above in the compositions (F) and (G) include polysaccharides consisting of monosaccharide derivatives, such as sulfated galactans and more particularly carrageenans and agar, uronans and more particularly alginates, alginates and pectins, heteropolymers of monosaccharides and uronic acids, and more particularly xanthan gum, gellan gum, gum arabic exudate and gum tragacanth exudate, or glucosaminoglycans.

[0122] Examples of thickeners and / or gelling agents that may be combined with the self-inverting inverse latex as defined above in the compositions (F) and (G) include cellulose, cellulose derivatives, such as methylcellulose, ethylcellulose or hydroxypropylcellulose, silicates, starches, hydrophilic starch derivatives or polyurethanes.

[0123] Examples of stabilizers that may be combined with the self-inverting inverse latex as defined above in the compositions (F) and (G) include microcrystalline waxes and more particularly ceresin wax, inorganic salts, such as sodium chloride or magnesium chloride, or silicone polymers, such as polysiloxane polyalkyl polyether copolymers.

[0124] Examples of solvents that may be combined with the self-inverting inverse latex as defined above in the compositions (F) and (G) include water, organic solvents, such as glycerol, diglycerol, glycerol oligomers, ethylene glycol, propylene glycol, butylene glycol, 1,3-propanediol, 1,2-propanediol, hexylene glycol, diethylene glycol, xylitol, erythritol, sorbitol, water-soluble alcohols (such as ethanol, isopropyl alcohol or butanol), or mixtures of water and the organic solvents.

[0125] Examples of thermal or mineral waters that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include thermal or mineral waters having a mineralization of at least 300 mg / I, in particular Avene water, Vittel water, Vichy basin water, Uriage water, La Roche-Posay water, La Bourboule water, Enghien-les-Bains water, Saint-Gervais-les-Bains water, Néris-les-Bains water, Allard-les-Bains water, Digne water, Maizières water, Neyrac-les-bains water, Lons-le-Saunier water, Rochefort water, Saint Christau water, Les Fumades water and Tercis-les-Bains water.

[0126] Examples of hydrotropic agents that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include xylenesulfonates, cumenesulfonates, hexyl polyglucoside, 2-ethylhexyl polyglucoside and n-heptyl polyglucoside.

[0127] Examples of emulsifying surfactants that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include nonionic surfactants, anionic surfactants or cationic surfactants.

[0128] Examples of emulsifying nonionic surfactants that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include esters of fatty acids and sorbitol, such as products sold under the name Montane TM 40, Montane TM 60, Montane TM 70, Montane TM 80 and Montane TM 85; compositions comprising glyceryl stearate and stearic acid ethoxylated with ethylene oxide between 5 mol and 150 mol, such as a composition comprising stearic acid ethoxylated with 135 mol of ethylene oxide and glyceryl stearate (under the name Simulsol TM(available for sale); dehydrated mannitol esters; ethoxylated dehydrated mannitol esters; sucrose esters; methyl glucoside esters; alkyl polyglycosides containing linear or branched, saturated or unsaturated aliphatic groups and containing from 14 to 36 carbon atoms, such as tetradecyl polyglucoside, hexadecyl polyglucoside, octadecyl polyglucoside, hexadecyl xyloside, octadecyl xyloside, eicosyl polyglucoside, dodecyl polyglucoside, 2-octyldodecyl xyloside or 12-hydroxystearyl polyglucoside; compositions containing linear or branched, saturated or unsaturated fatty alcohols containing from 14 to 36 carbon atoms and alkyl polyglycosides as described above, for example under the name Montanov TM 68, Montanov TM 14, Montanov TM 82, Montanov TM 202, Montanov TM S, Montanov TM WO18, Montanov TM L, Fluidanov TM 20X and Easynov TM compositions available for sale.

[0129] Examples of anionic surfactants that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include glyceryl stearate citrate, cetyl stearyl sulfate, soaps such as sodium stearate or triethanolamine stearate, and N-acylated derivatives of salted amino acids (e.g., stearoyl glutamate).

[0130] Examples of emulsifying cationic surfactants that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include amine oxides, quaternary ammonium salt-82, and the surfactants described in patent application WO 96 / 00719, and mainly those whose fatty chains contain at least 16 carbon atoms.

[0131] Examples of opacifying agents and / or pearlescing agents that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include sodium palmitate, sodium stearate, sodium hydroxystearate, magnesium palmitate, magnesium stearate, magnesium hydroxystearate, ethylene glycol monostearate, ethylene glycol distearate, polyethylene glycol monostearate, polyethylene glycol distearate, or fatty alcohols containing from 12 to 22 carbon atoms.

[0132] Examples of texturizing agents that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include N-acylated derivatives of amino acids, such as under the name Aminohope TMLauryl lysine sold by LL, under the name Dryflo TM Octenyl succinate starch sold by TM , under the name Montanov TM Myristyl polyglucoside, cellulose fiber, cotton fiber, chitosan fiber, talc, sericite or mica sold by .

[0133] Examples of deodorants that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include alkali metal silicates, zinc salts such as zinc sulfate, zinc gluconate, zinc chloride or zinc lactate; quaternary ammonium salts such as cetyltrimethylammonium salts or cetylpyridinium salts; glycerol derivatives such as glycerol decanoate, glycerol octanoate or polyglycerol decanoate; 1,2-decanediol, 1,3-propanediol; salicylic acid; sodium bicarbonate; cyclodextrin; metal zeolite; Triclosan TM ; aluminum bromide hydrate, aluminum chloride hydrate, aluminum chloride, aluminum sulfate, zirconium aluminum chloride hydrate, zirconium trichloride hydrate, zirconium tetrachloride hydrate, zirconium pentachloride hydrate, zirconium octachloride hydrate, aluminum sulfate, sodium lactate aluminum, complex of aluminum chloride hydrate and diol such as complex of aluminum chloride hydrate and propylene glycol, complex of aluminum dichloride hydrate and propylene glycol, complex of sesquichlorohydroxyaluminum and propylene glycol, complex of aluminum chloride hydrate and polyethylene glycol, complex of aluminum dichloride hydrate and polyethylene glycol, or complex of sesquichlorohydroxyaluminum and polyethylene glycol.

[0134] Examples of oils that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include mineral oils such as liquid paraffin, liquid petrolatum, isoparaffin or white mineral oil; oils of animal origin such as squalene or squalane; vegetable oils such as squalane, sweet almond oil, coconut oil, castor oil, jojoba oil, olive oil, rapeseed oil, peanut oil, sunflower oil, wheat germ oil, corn germ oil, soybean oil, cottonseed oil, alfalfa oil, poppy oil, pumpkin seed oil, evening primrose oil, millet oil, barley oil, rye oil, safflower oil, tung oil, passionflower oil, hazelnut oil, palm oil, shea butter, almond oil, calophyllum oil, sisymbrium oil, avocado oil, marigold oil, oils produced from flowers or vegetables, or ethoxylated vegetable oils; synthetic oils such as fatty acid esters, for example butyl myristate, propyl myristate, isopropyl myristate, cetyl myristate, isopropyl palmitate, octyl palmitate, butyl stearate, cetyl stearate, isopropyl stearate, octyl stearate, isocetyl stearate, dodecyl oleate, hexyl laurate, propylene glycol dicaprylate, esters derived from lanolin acids (such as isopropyl lanolate or isocetyl lanolate), fatty acid monoglycerides, glycerol diacylglycerols and glycerol triacylglycerols (such as triheptanoin), alkyl benzoates, hydrogenated oils, poly(α-olefins), polyolefins (such as poly(isobutene)), synthetic isoparaffins (such as isocetane or isododecane), or perfluorinated oils; silicone oils such as dimethylpolysiloxane, methylphenylpolysiloxane, silicone modified by amines, silicone modified by fatty acids, silicone modified by alcohols, silicone modified by alcohols and fatty acids, silicone modified by polyether groups, epoxy modified silicone, silicone modified by fluorinated groups, cyclic silicones, and silicone modified by alkyl groups. It should be understood that the term "oil" in this patent application means a compound and / or mixture of compounds that is insoluble in water and exists in a liquid appearance at a temperature of 25 °C.

[0135] Examples of waxes that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include beeswax, carnauba wax, candelilla wax, ouricury wax, Japan wax, cork fiber wax, sugarcane wax, paraffin wax, lignite wax, microcrystalline wax, lanolin wax; ozokerite, polyethylene wax, silicone wax, vegetable waxes, fatty alcohols and fatty acids that are solid at ambient temperature, or glycerol esters that are solid at ambient temperature. It should be understood that the term "wax" in this patent application means a compound and / or mixture of compounds that is insoluble in water and exists in a solid appearance at a temperature greater than or equal to 45 °C.

[0136] Examples of active ingredients that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include vitamins and their derivatives, especially their esters, such as retinol (vitamin A) and its esters (e.g., retinyl palmitate), ascorbic acid (vitamin C) and its esters, sugar derivatives of ascorbic acid (such as ascorbyl glucoside), tocopherol (vitamin E) and its esters (such as tocopheryl acetate), vitamin B3 or B10 (niacinamide and its derivatives); compounds showing whitening or depigmenting effects on the skin, such as TM MSH, Sepicalm TM ω-undecylenoyl phenylalanine sold under the name Sepiwhite MSH, Sepicalm VG, monoglyceride and / or diglyceride of ω-undecylenoyl phenylalanine, ω-undecylenoyl dipeptide, arbutin, kojic acid, hydroquinone; compounds showing a soothing effect, especially Sepicalm TM S, allantoin and bisabolol; anti-inflammatory agents; compounds showing a moisturizing effect, such as urea, hydroxyurea, glycerol, polyglycerol, glycerol glucoside, diglycerol glucoside, polyglycerol glucoside, xylitol glucoside; plant extracts rich in polyphenols, such as grape extract, pine extract, wine extract or olive extract; compounds showing slimming or lipolytic effects, such as caffeine or its derivatives, Adiposlim TM 、Adipoless TM 、fucoxanthin; N-acylated proteins; N-acylated peptides, such as Matrixyl TM ; N-acylated amino acids; partially hydrolyzed products of N-acylated proteins; amino acids; peptides; total hydrolyzed products of proteins; soybean extracts, such as Raffermine TM ; wheat extracts, such as Tensine TM or Gliadine TM ; plant extracts, such as plant extracts rich in tannins, plant extracts rich in isoflavones or plant extracts rich in terpenes; extracts of freshwater or seaweeds; marine plant extracts; marine extracts, usually such as corals; essential wax; bacterial extracts; ceramides; phospholipids; compounds showing antibacterial or purifying effects, such as Lipacide TM C8G, Lipacide TM UG, Sepicontrol TM A5; Octopirox TM or Sensiva TM SC50; compounds showing stimulating or excitatory properties, such as Physiogenyl TM 、panthenol and its derivatives, such as Sepicap TMMP; Anti-aging active ingredients, such as Sepilift TM DPHP, Lipacide TM PVB, Sepivinol TM , Sepivital TM , Manoliva TM , Phyto-Age TM , Timecode TM ; Survicode TM; anti-photoaging active ingredients; active ingredients that protect the integrity of the dermo-epidermal junction; active ingredients that increase the synthesis of extracellular matrix components such as collagen, elastin or glycosaminoglycans; active ingredients that act favorably on chemical cell communication such as cytokines, or active ingredients that act favorably on physical cell communication such as integrins; active ingredients that produce a "heating" sensation on the skin such as skin microcirculation activators (such as niacin derivatives) or products that produce a "cooling" sensation on the skin (such as menthol and derivatives); active ingredients that improve skin microcirculation such as venotonics; drainage active ingredients; active ingredients with decongestant purposes such as Ginkgo biloba, ivy, horse chestnut, bamboo, Ruscus, butcher's broom, Centella asiatica, fucus, rosemary or willow extracts; agents for tanning or darkening the skin such as dihydroxyacetone (DHA), erythrulose, mesoxalaldehyde, glutaraldehyde, glyceraldehyde, alloxan or ninhydrin, plant extracts such as redwood extracts of the genus Pterocarpus and Baphia such as Pterocarpus santalinus, Pterocarpus osun, Pterocarpus soyauxii, Pterocarpus erinaceus, Pterocarpus indicus or Baphia nitida, such as those described in European patent application EP 0971683; agents known for their action of promoting and / or accelerating the tanning or darkening of human skin and / or for their action of coloring human skin such as carotenoids (and more particularly β-carotene and γ-carotene)), products sold by Provital under the trade name "Carros Oil" (INCI name: Daucus Carota, sunflower oil) which contain carotenoids, vitamin E and vitamin K; tyrosine and / or its derivatives known for their action of accelerating the tanning of human skin when combined with exposure to ultraviolet radiation, such as the product sold by Provital under the trade name SunTan Accelerator TM sold containing tyrosine and riboflavin (vitamin B), the tyrosine and tyrosinase complex sold by Zymo Line under the trade name Zymo Tan Complex, MelanoBronze sold by Mibelle TMProducts sold containing acetyl tyrosine (INCI name: Acetyl Tyrosine, Monk's Pepper Extract (Vitex Agnus-castus)), products sold by Unipex under the trade name Unipertan VEG-24 / 242 / 2002 (INCI name: Butylene Glycol and Acetyl Tyrosine and Hydrolyzed Vegetable Protein and Adenosine Triphosphate), products sold by Sederma under the trade name Try-Excell TM (Products sold containing oleoyl tyrosine and Luffa Cylindrica extract (seed oil and oleic acid), which contain extracts of zucchini seeds (or luffa oil), sold by Alban Muller under the trade name Actibronze TM (Products sold containing hydrolyzed wheat protein and acetyl tyrosine and copper gluconate), sold by Synerga under the trade name Tyrostan TM (Products sold containing potassium hexanoyl tyrosine), sold by Synerga under the trade name Tyrosinol (INCI name: Sorbitan Isostearate, Glyceryl Oleate, Potassium Hexanoyl Tyrosine), products sold by Alban Muller under the trade name InstaBronze TM (Products sold containing dihydroxyacetone and acetyl tyrosine and copper gluconate), sold by Exymol under the trade name Tyrosilane (INCI name: Methylsilanol and Acetyl Tyrosine); peptides known for their role in activating melanogenesis, such as products sold by Infinitec Activos under the trade name Bronzing SF Peptide Powder (INCI name: Dextran and Octapeptide-5), products sold under the trade name Melitane (INCI name: Glycerin and Water and Dextran and Acetyl Hexapeptide-1), which contain Acetyl Hexapeptide-1 known for its α-MSH agonist action, sold by Lipotec under the trade name Melatimes Solutions TM (INCI name: Butylene Glycol,

[0137] Palmitoyl Tripeptide-40), sugars and sugar derivatives, such as products sold by Boiron under the trade name Tanositol TM (Products sold containing inositol), sold by Codif International under the trade name Thalitan TM (or Phycosaccharide TM AG) products (INCI name:

[0138] A product sold by Albion Millet Co., Ltd. under the trade name Melactiva, containing marine - derived oligosaccharides (guluronic acid and mannuronic acid chelated with magnesium and manganese ions), Aqua, hydrolyzed algae (Laminaria digitata), magnesium sulfate, and manganese sulfate TM (INCI name: Maltodextrin, Mucuna pruriens seed extract)) A product sold, rich in flavonoid compounds, such as a product sold by Silab under the trade name Biotanning (INCI name: Hydrolyzed orange fruit extract) and known to be rich in limonflavones (hesperidin type); Reagents intended for treating hair and / or body hair, such as reagents that protect the melanocytes of hair follicles, intended to protect said melanocytes from cytotoxins that are the cause of the senescence and / or apoptosis of said melanocytes, such as agents that mimic the activity of dopachrome tautomerase, as described in the European patent application disclosed under number EP 1 515 688 A2, synthetic molecules that mimic SOD, such as manganese complexes, antioxidant compounds, such as cyclodextrin derivatives, silica - containing compounds derived from ascorbic acid, lysine pyrrolidone carboxylate, or arginine pyrrolidone carboxylate, combinations of monoesters and diesters of cinnamic acid and vitamin C, and more generally those mentioned in the European patent application disclosed under number EP 1 515 688 A2.

[0139] Examples of antioxidants that can be combined with the self - reversible inverse latex as defined above in the compositions (F) and (G) include EDTA and its salts, citric acid, tartaric acid, oxalic acid, BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene), tocopherol derivatives such as tocopheryl acetate, mixtures of antioxidant compounds (such as Dissolvine sold by AkzoNobel under the INCI name: Tetrasodium glutamate diacetate TM GL 47S.

[0140] Examples of sunscreens that can be combined with the self - reversible inverse latex as defined above in the compositions (F) and (G) include all those appearing in Annex VII of the amended Cosmetics Directive 76 / 768 / EEC.

[0141] Organic sunscreens that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include the family of benzoic acid derivatives, such as p-aminobenzoic acid (PABA), in particular the monoglyceride of PABA, the ethyl ester of N,N-diethoxy PABA, the ethyl ester of N,N-dimethoxy PABA, the ethyl ester of N,N-dimethyl PABA, the methyl ester of N,N-dimethyl PABA, or the butyl ester of N,N-dimethyl PABA; the family of anthranilic acid derivatives, such as the trimethylcyclohexyl ester of N-acetylanthranilic acid; the family of salicylic acid derivatives, such as amyl salicylate, trimethylcyclohexyl salicylate, ethylhexyl salicylate, phenyl salicylate, benzyl salicylate, or p-isopropylphenyl salicylate; the family of cinnamic acid derivatives, such as ethylhexyl cinnamate, ethyl 4-isopropylcinnamate, methyl 2,5-diisopropylcinnamate, propyl p-methoxycinnamate, isopropyl p-methoxycinnamate, isoamyl p-methoxycinnamate, octyl p-methoxycinnamate (2-ethylhexyl p-methoxycinnamate), 2-ethoxyethyl p-methoxycinnamate, cyclohexyl p-methoxycinnamate, ethyl α-cyano-β-phenylcinnamate, 2-ethylhexyl α-cyano-β-phenylcinnamate, or bis(p-methoxycinnamic acid) mono(2-ethylhexanoyl) glycerol; the family of benzophenone derivatives, such as 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4'-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, 2-ethylhexyl 4'-phenylbenzophenone-2,5-dicarboxylate, 2-hydroxy-4-(n-octyloxy)benzophenone, 4-hydroxy-3-carboxybenzophenone; 3-(4'-methylbenzylidene)-d,l-camphor, 3-benzylidene-d,l-camphor, camphor benzalkonium methyl sulfate; urocanic acid, ethyl urocanate; the family of sulfonic acid derivatives, such as 2-phenylbenzimidazole-5-sulfonic acid and its salts; the family of triazine derivatives, such as hydroxyphenyltriazine, ethylhexyl oxyhydroxyphenyl-4-methoxyphenyltriazine, 2,4,6-trianilino(p-carbo-2'-ethylhexyl-1'-oxy)-1,3,5-triazine, 4,4-((6-(((1,1-dimethylethyl)amino)carbonyl)phenyl)amino)-1,3,5-triazine-2,4-diyl)diimino)bis-(2-ethylhexyl) ester of benzoic acid, 2-phenyl-5-methylbenzoxazole, 2,2'-hydroxy-5-methylphenylbenzotriazole, 2-(2'-hydroxy-5'-(tert-octyl)phenyl)benzotriazole, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole; dibenzazine; di-p-methoxybenzoylmethane, 4-methoxy-4''-tert-butylbenzoylmethane;5-(3,3-dimethyl-2-norbornene)-3-pent-2-one; the family of diphenylacrylate derivatives such as 2-ethylhexyl 2-cyano-3,3-diphenylacrylate or ethyl 2-cyano-3,3-diphenylacrylate; or those of the polysiloxane family such as benzylidene siloxane malonate.;

[0142] Inorganic sunscreens (also known as "inorganic filters") that can be combined with the self-reversible inverse latex as defined above in the compositions (F) and (G) include titanium oxide, zinc oxide, cerium oxide, zirconium oxide, yellow, red or black iron oxides, or chromium oxide. These inorganic filters can be micronized or not, can be surface-treated or not, and can optionally be presented in the form of an aqueous or oily pre-dispersion.

[0143] The following examples illustrate the invention, but do not limit the invention.

[0144] 1 - Example

[0145] 1.1 Preparation of an inverse latex (IL1) of a crosslinked copolymer of sodium 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonate and 2-hydroxyethyl acrylate containing disodium ethylenediamine disuccinate in the form of a trisodium salt as a multivalent chelating agent

[0146] Under stirring, the following were charged into a beaker:

[0147] - 632.5 g of a 55% commercial solution of sodium 2-methyl-[(1-oxo-2-propenyl)amino]-1-propanesulfonate

[0148] - 19.6 g of 2-hydroxyethyl acrylate

[0149] - 0.143 g of methylenebisacrylamide

[0150] - 0.62 g of a commercial solution of disodium ethylenediamine disuccinate in the form of a trisodium salt (sold under the trade name Natriquest TM E30)

[0151] - 0.1 g of copper sulfate pentahydrate.

[0152] The pH of the aqueous phase was adjusted to 4.0. The aqueous phase was made up to 660 g.

[0153] The organic phase was prepared in parallel by mixing the following:

[0154] - 240 g of isocetane

[0155] - 21 g of MontaneTM 70 (1)

[0156] (1): Montane TM 70 is sorbitan isostearate dehydrate sold by SEPPIC, i.e., a water-in-oil surfactant

[0157] Gradually add the aqueous phase prepared above to the oil phase, and then use an Ultra-Turrax TM sold by IKA TM type rotor-stator dispersion.

[0158] Subsequently, transfer the obtained emulsion to a jacketed reactor and subject it to nitrogen bubbling to remove oxygen. Introduce a 0.64% by weight solution of cumene hydroperoxide in isododecane, and keep the emulsion stirred at ambient temperature for 5 minutes for homogenization.

[0159] Initiate the polymerization reaction using a redox pair: cumene hydroperoxide / sodium metabisulfite. Once the polymerization reaction is complete, heat the reaction medium at 85 °C for 1 hour, then cool the entire mixture to approximately 35 °C, and subsequently add 33.7 g of Montanox TM 60 (2) to the formulation.

[0160] This test is called (IL1), and its characteristics are presented in Table 4.

[0161] (2): Montanox TM 60 is polyethoxylated sorbitan stearate sold by SEPPIC, i.e., an oil-in-water surfactant.

[0162] 1.2 Preparation of an inverse latex (IL2) containing sodium diethylenetriaminepentaacetate as a multivalent chelating agent, the sodium salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid, and a crosslinked copolymer of hydroxyethyl acrylate

[0163] Implement the same protocol as in Example 1.1, but replace a commercial solution of ethylenediamine disuccinic acid in the trisodium salt form with a solution of 0.45 g of sodium diethylenetriaminepentaacetate (sold under the trade name Versenex TM 80).

[0164] The product is called (IL2).

[0165] 1.3 Preparation of an inverse latex (IL3) of a crosslinked copolymer containing the sodium salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid and 2-hydroxyethyl acrylate and containing the tetrasodium salt of glutamic acid N,N-diacetic acid as a multivalent chelating agent

[0166] The same protocol as in Example 1.1 was implemented, but a commercial solution of ethylenediamine disuccinic acid in the trisodium salt form (0.62 g) was replaced with a solution of the tetrasodium salt of glutamic acid N,N-diacetic acid (sold under the trade name Dissolvine TM GLDA 47-S) (0.62 g).

[0167] The product was designated (IL3).

[0168] 1.4 Preparation of an inverse latex (IL4) of a crosslinked copolymer containing the sodium salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid and 2-hydroxyethyl acrylate and containing the sodium salt of iminodisuccinic acid as a multivalent chelating agent

[0169] The same protocol as in Example 1.1 was implemented, but a commercial solution of ethylenediamine disuccinic acid in the trisodium salt form (0.62 g) was replaced with a solution of the sodium salt of iminodisuccinic acid (sold under the trade name Baypure TM CX100) (0.62 g).

[0170] The product was designated (IL4).

[0171] [Table 1]

[0172]

[0173] Properties of the copolymers obtained in Examples 1.1, 1.2, 1.3, and 1.4.

[0174] In summary, tests of the copolymerization of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid and 2-hydroxyethyl acrylate by inverse emulsion radical polymerization showed that, in the presence of copper cations, the various chelating agents tested exhibited similar effectiveness. In each example, the polymerization exhibited the following similar characteristics: inhibition time, polymerization duration, and exothermicity. The self-reversible inverse latexes obtained under these conditions had equivalent thickening properties in water and in the presence of electrolytes.

Claims

1. A method for preparing a self-reversible inverse latex, the self-reversible inverse latex comprising an aqueous phase, the aqueous phase comprising: a) a crosslinked anionic polyelectrolyte (P), which consists of: - the monomer units produced from 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid in a proportion between 10% and 95%, in the form of free acid or partially or fully salified form; - the monomer units produced from at least one monomer selected from the group consisting of 2-hydroxyethyl acrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2,3-dihydroxypropyl methacrylate and vinylpyrrolidone in a proportion between 5% and 90%; and - monomer units produced from at least one polyene crosslinking monomer (AR) in a proportion greater than 0 mol% and less than or equal to 1 mol%, the polyene crosslinking monomer (AR) being selected from methylenebis(acrylamide), ethylene glycol dimethacrylate, diethylene glycol diacrylate, ethylene glycol diacrylate, diallylurea, triallylamine, trimethylolpropane triacrylate, diallyloxyacetic acid or one of its salts such as sodium diallyloxyacetate, or a mixture of these compounds; b) a polyvalent chelating compound (SQ) selected from at least one element of the group consisting of: disodium ethylenediamine disuccinate in the form of trisodium salt, tetrasodium glutamate N,N-diacetate and sodium salt of iminosuccinic acid, The method comprises the following stages: a) preparing an aqueous phase, the aqueous phase comprising monomers for obtaining the monomer units of the crosslinked anionic polyelectrolyte (P) and comprising the polyvalent chelating compound (SQ), b) preparing an organic phase comprising at least one oil (O) and a water-in-oil emulsifying surfactant (S1) system, c) mixing and emulsifying the aqueous phase prepared in stage a) and the organic phase prepared in stage b) to form an emulsion, d) inertizing the emulsion with nitrogen, e) initiating a polymerization reaction by introducing a radical initiator into the inertized emulsion, and f) introducing a water-in-oil emulsifying surfactant (S2) system into the reaction medium produced in stage e) at a temperature between 30 °C and 60 °C.

2. The method according to claim 1, characterized in that The aqueous phase comprises at least 0.01 mol% of the polyvalent chelating agent (SQ).

3. The method according to claim 1, characterized in that The polyene crosslinking monomer (AR) is methylenebis(acrylamide) or triallylamine.

4. The method according to claim 2, wherein The polyene crosslinking monomer (AR) is methylenebis(acrylamide) or triallylamine.

5. The method according to any one of claims 1 to 4, characterized in that In stage e), the free radical initiator is a redox pair that generates bisulfite (HSO3 - ) ions, such as the cumene hydroperoxide / sodium metabisulfite (Na2S2O5) pair or the cumene hydroperoxide / thionyl chloride (SOCl2) pair.

6. The method according to any one of claims 1 to 4, characterized in that, In stage e), a polymerization co-initiator is introduced into the inertized emulsion.

7. The method according to claim 5, characterized in that, In stage e), a polymerization co-initiator is introduced into the inertized emulsion.

8. The method according to claim 6, wherein In stage e), the polymerization co-initiator is azobis(isobutyronitrile).

9. The method according to claim 7, wherein In stage e), the polymerization co-initiator is azobis(isobutyronitrile).

10. The method according to any one of claims 1 to 4 and 7 to 9, characterized in that, In stage a), the pH of the aqueous phase is adjusted to between 3.0 and 7.

0.

11. The method according to any one of claims 1 to 4 and 7 to 9, characterized in that, Before carrying out stage f), the reaction medium produced in stage e) is concentrated by distillation.

12. The method according to any one of claims 1 to 4 and 7 to 9, characterized in that, The reaction medium produced in stage e) or f) is spray-dried.

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