Aqueous coating composition and process of making the same

Patent metadata

Field	Value
Publication number	US-10759947-B2
Application number	US-201515774094-A
Country	US
Kind code	B2
Filing date	Dec 14, 2015
Priority date	Dec 14, 2015
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

The present invention provides a novel aqueous coating composition comprising a multi-stage aqueous emulsion polymer, an anionic colloidal silica, and a thickener. This novel aqueous coating composition provides low gloss, while maintaining good physical stability and transparency.

First claim

What is claimed is:

1. An aqueous coating composition comprising,
(a) a multi-stage aqueous emulsion polymer comprising: from 20% to 80% by weight, based on dry weight of the multi-stage aqueous emulsion polymer, of a first polymer having an acid number of from 9 to 33, said first polymer having a calculated Mn of from 50,000 to 1,000,000; and
from 80% to 20% by weight, based on dry weight of the multi-stage aqueous emulsion polymer, of a second polymer having an acid number of from 0 to 7, said second polymer having a calculated Mn of from 50,000 to 1,000,000;

(b) an anionic colloidal silica; and
(c) an alkali-based thickener,
wherein the aqueous coating composition is characterized in that a coating made from the aqueous coating composition has a gloss number of 20 or less on 60° Gardner Gloss scale, and a transparency level of L* of less than or equal to 30 measured on a BYK Gardner Color-guide Sphere Spectrophotometer.

2. The aqueous coating composition of claim 1 , wherein the multi-stage aqueous emulsion polymer is present in an amount from 46% to 85% by weight, based on solid weight of the aqueous coating composition.

3. The aqueous coating composition of claim 1 , wherein the first polymer has an acid number of from 13 to 26.

4. The aqueous coating composition of claim 1 , wherein the second polymer has an acid number of from 0 to 5.

5. The aqueous coating composition of claim 1 , wherein the first polymer of the multi-stage aqueous emulsion polymer has a glass transition temperature of from −36° C. to 50° C.

6. The aqueous coating composition of claim 1 , wherein the second polymer of the multi-stage aqueous emulsion polymer has a glass transition temperature of from 30° C. to 100° c.

7. The aqueous coating composition of claim 1 , wherein the multistage emulsion polymer has a silane coupling agent from 0.1 to 5% by weight, based on solid weight of the aqueous coating composition.

8. The aqueous coating composition of claim 1 , wherein the anionic colloidal silica is present in an amount from 15% to 49% by weight, based on solid weight of the aqueous coating composition.

9. The aqueous coating composition of claim 1 , wherein the anionic colloidal silica has a pH value of greater than 8.5.

10. The aqueous coating composition of claim 1 , wherein the alkali-based thickener is an alkali swellable emulsion.

11. The aqueous coating composition of claim 1 , wherein the alkali-based thickener is an hydrophobically modified alkali swellable emulsion.

12. The aqueous coating composition of claim 1 , wherein the thickener is present in an amount of from 1% to 5% by weight, based on solid weight of the aqueous coating composition.

13. A method for providing a coating comprising,
(a) forming an aqueous coating composition comprising (1) mufti-stage aqueous emulsion polymer comprising: from 20% to 80% by weight, based on dry weight of the multi-stage aqueous emulsion polymer, of a first polymer having an acid number of from 9 to 33, said first polymer having a calculated Mn of from 50,000 to 1,000,000; and
from 80% to 20% by weight, based on dry weight of the multi-stage aqueous emulsion polymer, of a second polymer having an acid number of from 0 to 7,
said second polymer having a calculated Mn of from 50,000 to 1,000,000; ( 2 ) an anionic colloidal silica; and ( 3 ) an alkali-based thickener;

(b) applying the aqueous coating composition to a substrate; and
(c) drying, or allowing to dry, said applied aqueous coating composition wherein the coating has a gloss number of 20 or less on 60° Gardner Gloss scale, and a transparency level of L* of less than or equal to 30 measured on a BYK Gardner Color-guide Sphere Spectrophotometer.

Assignees

• Dow Global Technologies Llc
• Rohm & Haas

Inventors

• Wang Caifeng
• Xu Jianming
• Wang Yujiang
• Lan Yunfei

Classifications

• C09D5/022 Primary

  Emulsions, e.g. oil in water · CPC title

• C08F220/1808 Primary

  C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate · CPC title

• C09D133/064

  containing anhydride, COOH or COOM groups, with M being metal or onium-cation · CPC title

• C09D5/024

  characterised by the additives · CPC title

• C09D7/61

  inorganic · CPC title