Thickeners and hydraulic compositions

Patent metadata

Field	Value
Publication number	US-10858287-B2
Application number	US-201816164363-A
Country	US
Kind code	B2
Filing date	Oct 18, 2018
Priority date	Oct 31, 2017
Publication date	Dec 8, 2020
Grant date	Dec 8, 2020

Abstract

A thickener is provided comprising an anionic polyacrylamide group containing at least two anionic polyacrylamides having different degrees of anionization, and a water-soluble cellulose ether. When added to a hydraulic composition, the thickener is effective for improving flow while maintaining rheological properties.

First claim

The invention claimed is:

1. A thickener for hydraulic compositions consisting essentially of:
1 to 25% by weight of an anionic polyacrylamide group containing at least two anionic polyacrylamides having different degrees of anionization;
75 to 99% by weight of at least one hydroxyalkyl alkyl cellulose; and
0 to 20% by weight of a defoamer,
wherein the thickener does not include hydroxyalkyl celluloses.

2. The thickener of claim 1 wherein in the anionic polyacrylamide group containing at least two anionic polyacrylamides having different degrees of anionization, a difference in degree of anionization between anionic polyacrylamides is at least 3 mol %.

3. The thickener of claim 1 wherein in the anionic polyacrylamide group containing at least two anionic polyacrylamides having different degrees of anionization, a weighted average value of the degrees of anionization is from more than 2.0 mol % to 33.2 mol %.

4. The thickener of claim 1 wherein the anionic polyacrylamide group has an alkali metal or alkaline earth metal cation as the counter cation.

5. The thickener of claim 1 wherein the anionic polyacrylamide group consists of a first anionic polyacrylamide having a degree of anionization of 1 mol % to 6 mol % and a second anionic polyacrylamide having a degree of anionization of more than 6 mol % to 40 mol %.

6. The thickener of claim 1 wherein the at least one hydroxyalkyl alkyl cellulose has a 1 wt % aqueous solution viscosity of 30 to 30,000 mPa·s at 20° C.

7. The thickener of claim 1 wherein the at least one hydroxyalkyl alkyl cellulose is at least one cellulose selected from the group consisting of hydroxypropyl methyl cellulose and hydroxyethyl methyl cellulose.

8. A hydraulic composition comprising the thickener of claim 1 , a hydraulic substance, and water.

9. The thickener of claim 1 wherein the at least one hydroxyalkyl alkyl cellulose is hydroxypropyl methyl cellulose or hydroxyethyl methyl cellulose.

10. The thickener of claim 1 wherein the defoamer is any one selected from the group consisting of oxyalkylene, silicone, alcohol, mineral oil, fatty acid, and fatty acid ester base defoamers.

11. The thickener of claim 1 wherein the defoamer is any one selected from the group consisting of oxyalkylene base defoamers.

12. The thickener of claim 1 wherein the anionic polyacrylamide group is present in an amount of 1 to 10% by weight.

13. The thickener of claim 1 wherein the defoamer is present in an amount of 5 to 20% by weight.

14. The hydraulic composition of claim 8 wherein the thickener is present in an amount of 0.004 to 0.065% by weight when the hydraulic composition is for concrete use.

15. The hydraulic composition of claim 8 wherein the thickener is present in an amount of 0.006 to 0.094% by weight when the hydraulic composition is for mortar use.

16. The hydraulic composition of claim 8 wherein the thickener is present in an amount of 0.018 to 0.265% by weight when the hydraulic composition is for cement paste use.

17. The thickener of claim 1 wherein the anionic polyacrylamide group consists of two anionic polyacrylamides having different degrees of anionization, a difference in degree of anionization between anionic polyacrylamides is at least 3 mol %.

18. The thickener of claim 1 wherein the at least one hydroxyalkyl alkyl cellulose has a 1 wt % aqueous solution viscosity of 500 to 20,000 mPa·s at 20° C.

Assignees

• Shinetsu Chemical Co

Inventors

• Saito Hironao
• Konishi Hidekazu
• Yamakawa Tsutomu

Classifications

• C08L33/26 Primary

  Homopolymers or copolymers of acrylamide or methacrylamide · CPC title

• C08L1/26

  Cellulose ethers · CPC title

• C04B2103/44

  Thickening, gelling or viscosity increasing agents · CPC title

• C04B28/02 Primary

  containing hydraulic cements other than calcium sulfates · CPC title

• C04B2111/62

  Self-levelling compositions · CPC title