INVERSE LATEX FOR A COSMETIC COMPOSITION COMPRISING A SPECIFIC CHELATING AGENT AND A POLYELECTROLYTE COMBINING A STRONG ACID FUNCTION AND A NEUTRAL FUNCTION

Abstract

Disclosed is a self-invertible inverse latex having an aqueous phase, including: a) a cross-linked anionic polyelectrolyte (P) including:—at least one first monomer unit derived from 2-methyl-2-[(1-oxo-2-propenyl)amino] 1-propane sulfonic acid in the form of a free or partially or totally salified acid; and—at least one second monomer unit derived from at least one monomer selected from the elements of the group consisting of (2-hydroxyethyl)acrylate, (2,3-dihydroxypropyl)acrylate, (2-hydroxyethyl)methacrylate, (2,3-dihydroxypropyl)methacrylate, or vinylpyrrolidone; and—at least one monomer unit derived from a cross-linking polyethylenic monomer (AR); b) at least one chelating compound (SQ) selected from the elements of the group consisting of ethylenediamine disuccinic acid in the form of trisodium salt, tetrasodium salt of glutamic acid, N,N diacetic, or the sodium salt of imminosuccinic acid.

Claims

1. A self-invertible inverse latex comprising an aqueous phase comprising: a) a crosslinked anionic polyelectrolyte (P) consisting of: at least one first monomer unit resulting from 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid in free acid or partially or completely salified form; and at least one second monomer unit resulting from at least one monomer chosen from the elements of the group consisting of 2-hydroxyethyl acrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2,3-dihydroxypropyl methacrylate and vinylpyrrolidone; and at least one monomer unit resulting from a polyethylenic crosslinking monomer (AR); b) at least one sequestering compound (SQ) chosen from the elements of the group consisting of ethylenediamine disuccinic acid in the trisodium salt form, the tetrasodium salt of glutamic acid, N,N diacetic acid, and the sodium salt of iminosuccinic acid.

2. The inverse latex as claimed in claim 1, wherein the aqueous phase comprises at least 0.01 molar % of the sequestering agent (SQ).

3. The inverse latex as claimed claim 1, wherein the polyethylenic crosslinking monomer (AR) is chosen from methylenebis(acrylamide), ethylene glycol dimethacrylate, diethylene glycol diacrylate, ethylene glycol diacrylate, diallylurea, triallylamine, trimethylolpropane triacrylate, diallyloxyacetic acid or one of its salts, or a mixture of these compounds.

4. The inverse latex as claimed in claim 1, wherein the polyethylenic crosslinking monomer (AR) is methylenebis(acrylamide) or triallylamine.

5. The inverse latex as claimed in claim 1, wherein the crosslinked anionic polyelectrolyte comprises, per 100 molar %: a) a proportion between 10% and 95% of the monomer unit resulting from 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid in free acid or partially or completely salified form; b) a proportion between 5% and 90% of the monomer unit resulting from at least one monomer chosen from the elements of the group consisting of 2-hydroxyethyl acrylate, 2,3-dihydroxypropyl acrylate, 2-hydroxyethyl methacrylate, 2,3-dihydroxypropyl methacrylate and vinylpyrrolidone; and c) a proportion of greater than 0 molar % and less than or equal to 1 molar % of monomer units resulting from at least one polyethylenic crosslinking monomer (AR).

6. A process for the preparation of an inverse latex as defined in claim 1, comprising the following stages: a) preparation of the aqueous phase as defined in claim 1, b) preparation of an organic phase comprising at least one oil (O) and an emulsifying surfactant (S.sub.1) system of water-in-oil type, c) mixing the aqueous phase and the organic phase prepared in stages a) and b) and emulsifying so as to form an emulsion, d) inerting the emulsion with nitrogen, e) initiating the polymerization reaction by introduction, into the inerted emulsion, of a free-radical initiator, and f) introduction, into the reaction medium resulting from stage e), of an emulsifying surfactant (S.sub.2) system of oil-in-water type at a temperature of between 30° C. and 60° C.

7. The process as claimed in claim 6, wherein, in stage e), the radical initiator is a redox pair which generates hydrogensulfite (HSO.sub.3.sup.−) ions

8. The process as claimed in claim 6, wherein, in stage e), a polymerization coinitiator, is introduced into the inerted emulsion.

9. The process as claimed in claim 6, wherein, in stage a), the pH of the aqueous phase is adjusted to between 3.0 and 7.0.

10. The process as claimed in claim 6, wherein the reaction medium resulting from stage e) is concentrated by distillation before carrying out stage f).

11. The process as claimed in claim 6, wherein the reaction medium resulting from stage e) or f) is spray dried.

12. A thickening and/or emulsifying and/or stabilizing agent of a topical cosmetic composition comprising the inverse latex of claim 1.

13. A topical cosmetic composition comprising, as thickening agent, per 100% of its total weight, between 0.1% and 10% by weight of said inverse latex as defined in claim 1.

14. A topical pharmaceutical composition comprising, as thickening agent, per 100% of its total weight, between 0.1% and 10% by weight of said inverse latex as defined in claim 1.

15. The process of claim 7, wherein the redox pair is the cumene hydroperoxide/sodium metabisulfite (Na2S2O5) pair.

16. The process of claim 7, wherein the redox pair is the cumene hydroperoxide/thionyl chloride (SOC12) pair.

17. The process of claim 8, wherein the polymerization coinitiator is azobis(isobutyronitrile).

18. The inverse latex as claimed in claim 2, wherein the polyethylenic crosslinking monomer (AR) is chosen from methylenebis(acrylamide), ethylene glycol dimethacrylate, diethylene glycol diacrylate, ethylene glycol diacrylate, diallylurea, triallylamine, trimethylolpropane triacrylate, diallyloxyacetic acid or one of its salts, or a mixture of these compounds.

19. The inverse latex as claimed in claim 2, wherein the polyethylenic crosslinking monomer (AR) is methylenebis(acrylamide) or triallylamine.

20. The inverse latex as claimed in claim 3, wherein the polyethylenic crosslinking monomer (AR) is methylenebis(acrylamide) or triallylamine.

Description

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0110] The following examples illustrate the invention without, however, limiting it.

1- EXAMPLES

1.1 Preparation of an Inverse Latex (IL.SUB.1.) Comprising a Crosslinked Copolymer of the Sodium Salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid and of hydroxyethyl acrylate Containing ethylenediamine disuccinic Acid in the Trisodium Salt Form as Sequestering Agent

[0111] The following are charged to a beaker with stirring: [0112] 632.5 g of a 55% commercial solution of sodium salt of 2-methyl-[(1-oxo-2-propenyl) amino]-1-propanesulfonic acid [0113] 19.6 g of hydroxyethyl acrylate [0114] 0.143 g of methylenebisacrylamide [0115] 0.62 g of a commercial solution of ethylenediamine disuccinic acid in the trisodium salt form (sold under the brand name Natriquest™ E30) [0116] 0.1 g of copper sulfate pentahydrate.

[0117] The pH of the aqueous phase is adjusted to 4.0. The aqueous phase is made up to 660 g.

[0118] The organic phase is prepared in parallel by mixing: [0119] 240 g of isohexadecane [0120] 21 g of Montane™ 70.sup.(1) [0121] (1): Montane™ 70 is a sorbitan isostearate, surfactant of water-in-oil type, sold by SEPPIC

[0122] The aqueous phase prepared above is gradually added to the oily phase and then dispersed using a rotor-stator of Ultra-Turrax™ type sold by IKA™. [0123] The emulsion obtained is subsequently transferred into a jacketed reactor and subjected to nitrogen sparging in order to remove the oxygen. A 0.64% by weight solution of cumene hydroperoxide in isohexadecane is introduced and the emulsion is kept stirred for 5 minutes of homogenization at ambient temperature. [0124] The polymerization reaction is initiated using the redox pair: cumene hydroperoxide/sodium metabisulfite. Once the polymerization reaction has finished, the reaction medium is heated at 85° C. for 1 h, then the whole mixture is cooled to approximately 35° C. and subsequently 33.7 g of Montanox™ 60.sup.(2)are added to the preparation. [0125] The test is referenced (IL.sub.1) and its characteristics are presented in table 4. [0126] (2): Montanox™ 60 is a polyethoxylated sorbitan stearate, surfactant of oil-in-water type, sold by SEPPIC.

1.2 Preparation of an Inverse Latex (IL.SUB.2.) Comprising a Crosslinked Copolymer of the Sodium salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid and of Hydroxyethyl Acrylate Containing sodium diethylenetriaminepentaacetate as Sequestering Agent

[0127] The same protocol as example 1.1 is implemented but the 0.62 g of a commercial solution of ethylenediamine disuccinic acid in the trisodium salt form is replaced by 0.45 g of a solution of sodium diethylenetriaminepentaacetate (sold under the brand name Versenex™ 80).

[0128] The product is referenced (IL.sub.2).

1.3 Preparation of an Inverse Latex (113) Comprising a Crosslinked Copolymer of the Sodium Salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid and of Hydroxyethyl Acrylate Containing the Tetrasodium Salt of Glutamic Acid, N,N-diacetic Acid as Sequestering Agent

[0129] The same protocol as example 1.1 is implemented but the 0.62 g of a commercial solution of ethylenediamine disuccinic acid in the trisodium salt form is replaced by 0.62 g of a solution of the tetrasodium salt of glutamic acid, N,N-diacetic acid (sold under the brand name Dissolvine™ GLDA 47-S).

[0130] The product is referenced (IL.sub.3).

1.4 Preparation of an Inverse Latex (IL.SUB.4.) Comprising a Crosslinked Copolymer of the Sodium salt of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid and of Hydroxyethyl Acrylate Containing the Sodium Salt of Iminodisuccinic Acid as Sequestering Agent

[0131] The same protocol as example 1.1 is implemented but the 0.62 g of a commercial solution of ethylenediamine disuccinic acid in the trisodium salt form is replaced by 0.62 g of a solution of the sodium salt of iminodisuccinic acid (sold under the brand name Baypure™ CX100).

[0132] The product is referenced (IL.sub.4).

TABLE-US-00001 TABLE 1 Characterizations Viscosity of Viscosity of Polymerization Viscosity of aqueous gel at aqueous gel at Sequestering Polymer- latex at 25° C., 2% by weight, 3% by weight + agent Inhibi- Exother- ization mPa .Math. s mPa .Math. s 0.1% NaCl, mPa .Math. s Test (amount in tion micity duration (Brookfield RVT, (Brookfield RVT, (Brookfield RVT, No. molar ppm)(*) (min) (° C.) (min) Spindle 3, Speed 20) Spindle 6, Speed 5) Spindle 6, Speed 5) (IL.sub.2) Versenex ™ 80 1 33 12.4 1710  98 000 8400 (210 ppm) (IL.sub.1) Natriquest ™ E30 1 32.8 12 2410 107 000 8600 (345 ppm) (IL.sub.3) Dissolvine ™ 0 31.7 8 2040 102 400 10 200   GLDA 47-S (485 ppm) (IL.sub.4) Baypure ™ CX 100 0 30.4 10 1660  92 200 5800 (368 ppm)
Properties of the copolymers obtained in examples 1.1, 1.2, 1.3 and 1.4.

[0133] In conclusion, the tests on the copolymerization of 2-methyl-2-[(1-oxo-2-propenyl)amino]-1-propanesulfonic acid and of 2-hydroxyethyl acrylate by inverse emulsion radical polymerization show that, in the presence of copper cations, the various chelating agents tested exhibit a similar effectiveness. In each of the examples, the polymerization exhibits similar characteristics: inhibition time, polymerization duration and exothermicity. The self-invertible inverse latexes obtained under these conditions have equivalent thickening properties in water and in the presence of electrolytes.