Water-based polymer dispersions and uses thereof

Patent metadata

Field	Value
Publication number	US-11897982-B2
Application number	US-201816969684-A
Country	US
Kind code	B2
Filing date	Feb 13, 2018
Priority date	Feb 13, 2018
Publication date	Feb 13, 2024
Grant date	Feb 13, 2024

Abstract

Vinyl ester/ethylene copolymer aqueous dispersions containing an anionic polyacrylamide, at least one polyvinyl alcohol, and optionally a non-ionic surfactant, are useful in cementitious compositions as polymer additives.

First claim

What is claimed is:

1. An aqueous polymer dispersion, comprising:
i) a copolymer prepared by the polymerization of comonomers comprising a vinyl ester and ethylene,
ii) an anionic polyacrylamide,
iii) a polyvinyl alcohol, and
iv) water,
wherein the anionic polyacrylamide is present in an amount of at least 0.15 wt. %, based on the total weight of the vinyl ester and ethylene monomers.

2. The aqueous polymer dispersion of claim 1 , wherein the anionic polyacrylamide is present in an amount of 0.15 to 0.45 wt. %.

3. The aqueous polymer dispersion of claim 1 , wherein further comonomers are polymerized in an amount of less than 5 wt % based on the total weight of the vinyl ester and ethylene monomers.

4. The aqueous polymer dispersion of claim 1 , wherein the number average molecular weight of the anionic polyacrylamide is from 1×10 5 to 1×10 7 g/mol.

5. The aqueous polymer dispersion of claim 1 , wherein the aqueous polymer dispersion further comprises a nonionic surfactant with an HLB value of from 13 to 20.

6. The aqueous based polymer dispersion of claim 5 , wherein the nonionic surfactant are C 4 -C 40 alkyl alcohol ethoxylates having 10 to 60 EO units.

7. The aqueous polymer dispersion of claim 5 , wherein the nonionic surfactants are present in an amount of from 0.2 to 0.8 wt %, based on the total weight of the vinyl ester and ethylene monomers.

8. The aqueous polymer dispersion of claim 1 , wherein the polyvinyl alcohol comprises at least one medium molecular weight polyvinyl alcohol and at least one low molecular weight polyvinyl alcohol, wherein the medium molecular weight polyvinyl alcohol is a polyvinyl alcohol having a Hoppler viscosity, in 4 wt % aqueous solution, of from 10 to 35 mPa·s as measured at 20° C. according to DIN 53015, and
the low molecular weight polyvinyl alcohol is a polyvinyl alcohol having a Hoppler viscosity, in 4 wt % aqueous solution, of from 3 to less than 10 mPa·s as measured at 20° C. according to DIN 53015.

9. The aqueous polymer dispersion of claim 8 , wherein the medium molecular weight polyvinyl alcohol comprises a first medium molecular weight polyvinyl alcohol and a second medium molecular weight polyvinyl alcohol,
wherein the first medium molecular weight polyvinyl alcohol has a Hoppler viscosity, in 4 wt% aqueous solution, of from 20 to 30 mPa·s as measured at 20° C. according to DIN 53015, and
the second medium molecular weight polyvinyl alcohol has a Hoppler viscosity, in 4 wt % aqueous solution, of from 10 to less than 20 mPa·s as measured at 20° C. according to DIN 53015.

10. The aqueous polymer dispersion of claim 8 , wherein the mass ratio of the medium molecular weight polyvinyl alcohol to the low molecular weight polyvinyl alcohol is 0.6 to 2.5:1.

11. The aqueous polymer dispersions of claim 8 , wherein the polyvinyl alcohol is present in an amount of from 2 to 8 wt %, based on the total weight of the vinyl ester and ethylene monomers.

12. The aqueous polymer dispersion of claim 1 , wherein the anionic polyacrylamide is added after the polymerization is completed.

13. The aqueous polymer dispersion of claim 5 , wherein the mass ratio of the nonionic surfactant to the anionic polyacrylamide is 0.5 to 1.5:1 when the nonionic surfactant is added after the polymerization is completed, and
the mass ratio of the nonionic surfactant to the anionic polyacrylamide is 0.3-1.2:1 when the nonionic surfactant is added prior to the initiation of the polymerization.

14. The aqueous polymer dispersion of claim 8 , wherein all polyvinyl alcohols are added prior to the initiation of the polymerization.

15. A polymer modified cement-based coating containing an aqueous polymer dispersion of claim 1 .

16. A polymer modified cement composition comprising liquid and powder components, characterized in that the liquid component comprises an aqueous polymer dispersion of claim 1 .

Assignees

• Wacker Chemie Ag
• Zheng Jin

Inventors

• Zheng Jin
• Huang Lingyun
• Li Yun
• Sun Haoqing
• Zhang Jiyang

Classifications

• C08F220/285 Primary

  and containing a polyether chain in the alcohol moiety · CPC title

• C04B24/2623

  Polyvinylalcohols; Polyvinylacetates · CPC title

• C04B24/2647

  containing polyether side chains · CPC title

• C04B24/2652

  Nitrogen containing polymers, e.g. polyacrylamides, polyacrylonitriles · CPC title

• C04B40/0039

  Premixtures of ingredients · CPC title