Method for thickening a cosmetic formulation using an alkali swellable emulsion of a polymer with amps and which is rich in acrylic acid

Patent metadata

Field	Value
Publication number	US-11065191-B2
Application number	US-201615291504-A
Country	US
Kind code	B2
Filing date	Oct 12, 2016
Priority date	Mar 7, 2011
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

Process for thickening a composition, through the use of a direct emulsion in water, which is alkali-swellable, of a polymer of the ASE or HASE type, which is both rich in acrylic acid and which has a certain quantity of AMPS. The use of such emulsions simultaneously allows there to be no obligation to use surfactants and organic solvents other than water, and allows the thickening phenomenon to be activated for pHs of less than 7: this latter characteristic is particularly advantageous for formulations intended to be used in contact with skin.

First claim

The invention claimed is:

1. A method for thickening a formulation, the method comprising:
contacting the formulation with a direct aqueous emulsion of a polymer, followed by
regulating a pH of the formulation to a value between 5 and 7, thereby forming a thickened formulation,
wherein the emulsion is free from surfactants and organic solvents other than water and
the polymer consists, expressed as a content by weight of monomers therein, of:
a) from 20% to 60% by weight of acrylic acid and, optionally, methacrylic acid, wherein a content by weight of acrylic acid compared to a total weight of acrylic and methacrylic acid is at least 50%,
b) from 40% to 80% by weight of ethyl acrylate, butyl acrylate, methyl methacrylate, or any combination thereof,
c) from 0.05% to 22% by weight of 2-acrylamido-2-methylpropane sulfonic acid, and
d) from 0 to 1% by weight of at least one cross-linked monomer.

2. The method according to claim 1 , wherein the cross-linked monomer is present and is ethylene glycol dimethacrylate, trimethylolpropanetriacrylate, diallyl phtalate, allyl acrylate, an allyl maleate, methylene-bis-acrylamide, methylene-bis-methacrylamide, tetraallyloxyethane, a triallylcyanurate, an allylic ether, an acrylic ester obtained from a polyol, a methacrylic ester obtained from a polyol, a methacrylurethane ester obtained from a polyol, or any combination thereof.

3. The method according to claim 1 , wherein the aqueous emulsion has a dry extract of between 10% and 50% by dry weight of polymer, compared to its total weight.

4. The method according to claim 1 , wherein the emulsion has a particle size of between 50 nm and 500 nm.

5. The method according to claim 1 , wherein the polymer has an average molar mass by weight of between 20,000 g/mole and 1,000,000 g/mole.

6. The method according to claim 1 , wherein the content by weight of acrylic acid compared to the total weight of the acrylic acid and methacrylic acid is from 80% to 100%.

7. The method according to claim 1 , wherein the content by weight of acrylic acid compared to the total weight of the acrylic acid and methacrylic acid is from 98% to 100%.

8. The method according to claim 1 , wherein the polymer does not comprise methacrylic acid.

9. The method according to claim 1 , wherein the formulation is a cosmetic formulation.

10. The method according to claim 9 , wherein the cosmetic formulation comprises a surfactant and is suitable for application to human skin.

11. The method according to claim 1 , wherein the formulation has a pH of from 5 to 6.5 after thickening.

12. The method according to claim 8 , wherein the formulation has a pH of from 5.5 to 6 after thickening.

13. The method according to claim 1 , wherein the 40% to 80% by weight of (b) is a combination of two monomers selected from the group consisting of ethyl acrylate, butyl acrylate, and methyl methacrylate, or else is a combination of ethyl acrylate, butyl acrylate, and methyl methacrylate.

14. The method according to claim 1 , wherein, for a 1% dry weight content of the polymer in the thickened formulation, a viscosity of the thickened formulation is at least 1200 mPas at a pH of 7.

15. The method according to claim 1 , wherein, for a 1% dry weight content of the polymer in the thickened formulation, a viscosity of the thickened formulation is at least 400 mPas greater at a pH of 6 than at a pH of 5.

16. The method according to claim 1 , wherein, for a 1% dry weight content of the polymer in the thickened formulation, a viscosity of the thickened formulation is at least 1200 mPa·s greater at a pH of 7 than at a pH of 5.

17. The method according to claim 15 , wherein, for a 1% dry weight content of the polymer in the thickened formulation, a viscosity of the thickened formulation is at least 1200 mPa·s greater at a pH of 7 than at a pH of 5.

18. The method according to claim 1 , wherein:
the emulsion has a particle size of between 50 nm and 500 nm, and
the polymer has an average molar mass by weight of between 20,000 g/mole and 1,000,000 g/mole.

19. The method according to claim 18 , wherein the content by weight of acrylic acid compared to the total weight of the acrylic acid and methacrylic acid is from 80% to 100%.

20. The method according to claim 19 , wherein the cross-linked monomer is present and is ethylene glycol dimethacrylate, trimethylolpropanetriacrylate, diallyl phtalate, allyl acrylate, an allyl maleate, methylene-bis-acrylamide, methylene-bis-methacrylamide, tetraallyloxyethane, a triallylcyanurate, an allylic ether, an acrylic ester obtained from a polyol, a methacrylic ester obtained from a polyol, a methacrylurethane ester obtained from a polyol, or any combination thereof.

Assignees

• Coatex Sas

Inventors

• Souzy Renaud
• Suau Jean-Marc
• Kensicher Yves
• Guerret Olivier

Classifications

• C08F220/585

  and containing other heteroatoms, e.g. 2-acrylamido-2-methylpropane sulfonic acid [AMPS] · CPC title

• C08F220/288

  and containing polypropylene-co-ethylene oxide in the alcohol moiety · CPC title

• C08F220/12

  of monohydric alcohols or phenols · CPC title

• A61K8/81 Primary

  obtained by reactions involving only carbon-to-carbon unsaturated bonds · CPC title

• C08F220/06

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title