Low-concentration, inverse emulsion obtained by polymerization of weakly neutralized polymers

Patent metadata

Field	Value
Publication number	US-9963532-B2
Application number	US-201615014247-A
Country	US
Kind code	B2
Filing date	Feb 3, 2016
Priority date	Feb 21, 2013
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

The present invention relates to a polymer prepared by polymerization of an aqueous solution of one or more monomers in water-in-oil inverse emulsion, in which one or more of the monomers used comprise(s) at least one acid function, the molar percentage of monomers bearing at least one weak acid function relative to all the monomers used being at least 30%. The polymerization is carried out with a concentration of all the monomers in aqueous solution which falls within the range of from 1.3 mmol to 3.6 mmol per gram of aqueous solution and during the polymerization, at most 20% of the acid functions present on the monomers which have at least one acid function are in neutralized form.

First claim

What is claimed is:

1. A polymer in the form of a water-in-oil inverse emulsion obtained by polymerization of an aqueous solution of one or more monomers in water-in-oil inverse emulsion, in which one or more of the monomers used comprise(s) at least one acid function, the molar percentage of monomers bearing at least one weak acid function relative to all the monomers used being at least 30%, wherein:
i) the polymerization is carried out with a concentration of all the monomers in aqueous solution which falls within the range of from 1.3 mmol to 3.6 mmol per gram of aqueous solution, and
ii) during the polymerization, at most 20% of the acid functions present on the monomers which have at least one acid function are in neutralized form.

2. The polymer as claimed in claim 1 , wherein at most 20% of the acid functions present in the polymer are in neutralized form.

3. The polymer as claimed in claim 2 , subsequently subjected to a neutralization step resulting in a percentage of neutralized acid functions relative to all the acid functions present on the polymer of from 30% to 100%.

4. The polymer as claimed in claim 1 , which is branched or crosslinked.

5. The polymer as claimed in claim 1 , subsequently subjected to an isolation step so as to be in the form of a powder.

6. The polymer as claimed in claim 5 , wherein the isolation step is selected from the group consisting of precipitation, azeotropic distillation and spray-drying techniques.

7. The polymer as claimed in claim 1 , which is water-soluble or water-swelling.

8. The polymer as claimed in claim 1 , wherein at most 5% of the acid functions present in the polymer are in neutralized form.

9. The polymer as claimed in claim 1 , wherein at most 2% of the acid functions present in the polymer are in neutralized form.

10. The polymer as claimed in claim 1 , wherein, during the polymerization, at most 5% of the acid functions present on the monomers which have at least one acid function are in neutralized form.

11. The polymer as claimed in claim 2 , wherein, during the polymerization, at most 2% of the acid functions present on the monomers which have at least one acid function are in neutralized form.

12. The polymer as claimed in claim 3 , wherein all the acid functions present on the monomers are in free acid form during the polymerization.

13. The polymer as claimed in claim 1 , wherein the polymerization is carried out with a concentration of all the monomers in aqueous solution which falls within the range of from 1.7 to 3.3 mmol per gram of aqueous solution.

14. The polymer as claimed in claim 1 , wherein the molar percentage of monomers bearing one or more weak acid function(s) relative to all the monomers used which bear an acid function is at least 50%.

15. The polymer as claimed in claim 1 , wherein all the monomers used are monomers which have at least one ethylenic unsaturation.

16. The polymer as claimed in claim 1 , wherein the monomer bearing at least one weak acid function, in free acid form, is selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid and fumaric acid.

17. The polymer as claimed in claim 1 , wherein the polymerization is carried out with at least one neutral monomer selected from the group consisting of acrylamide, methacrylamide, N,N-dimethylacrylamide, N-vinylmethylacetamide, N-vinylformamide, vinyl acetate, diacetone acrylamide, N-isopropylacrylamide, N-[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]propenamide, (2-hydroxyethyl) acrylate, (2,3-dihydroxypropyl) acrylate, methyl methacrylate, (2-hydroxyethyl) methacrylate, (2,3-dihydroxypropyl) methacrylate and vinylpyrrolidone, in addition to the said monomers bearing at least one weak acid function.

18. The polymer as claimed in claim 1 , wherein all the monomers used to carry out the polymerization which bear at least one acid function are monomers bearing one or more weak acid function(s).

19. The polymer as claimed in claim 17 , wherein the polymerization is carried out with a mixture of acrylic acid/acrylamide monomers, with a degree of neutralization of the acid functions, wherein at most 20% of the acid functions present on the monomers, which have at least one acid function are in neutralized form, or wherein all of the acid functions present on the monomers are in free acid form during polymerization, wherein the acrylic acid monomer is the monomer bearing the weak acid function and the acrylamide monomer is the neutral monomer.

20. The polymer as claimed in claim 1 , wherein the polymerization is carried out with at least one monomer bearing one or more strong acid function(s) in addition to at least one monomer bearing at least one weak acid function.

21. The polymer as claimed in claim 20 , wherein the polymerization is carried out with a molar percentage of monomers bearing one or more strong acid function(s) relative to all the monomers used of less than 50%.

22. The polymer as claimed in claim 20 , wherein the monomer bearing one or more strong acid function(s), in free acid form, is an acrylamidoalkylsulfonic acid.

23. The polymer as claimed in claim 20 , wherein the polymerization is carried out with a mixture of 2-acrylamido-2-methylpropanesulfonic acid/acrylic acid monomers or a mixture of 2-acrylamido-2-methylpropanesulfonic acid/acrylic acid/acrylamide monomers, with a degree of neutralization of the acid functions, wherein the 2-acrylamido-2 methylpropanesulfonic acid monomer is the monomer bearing a strong acid function, the acrylic acid monomer is the monomer bearing the weak acid function, and the acrylamide monomer is the neutral monomer.

Assignees

• Spcm Sa

Inventors

• Blondel Frederic
• Champagnon Lionel

Classifications

• C08F220/06 Primary

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

• C08F220/38

  Esters containing sulfur · CPC title

• C08F220/56

  Acrylamide; Methacrylamide · CPC title

• C08F2/32

  Polymerisation in water-in-oil emulsions · CPC title

• C08F220/10

  Esters · CPC title