	US 12,492,304 B2
	Aqueous dispersion of opacifying pigment particles and colorant
Qing Zhang, Collegeville, PA (US); and Yujie Lu, Blue Bell, PA (US)
Assigned to Rohm and Haas Company, Collegeville, PA (US)
Appl. No. 18/027,673
Filed by Rohm and Haas Company, Collegeville, PA (US)
PCT Filed Sep. 24, 2021, PCT No. PCT/US2021/051890 § 371(c)(1), (2) Date Mar. 22, 2023, PCT Pub. No. WO2022/076178, PCT Pub. Date Apr. 14, 2022.
Prior Publication US 2023/0383112 A1, Nov. 30, 2023
Int. Cl. C08L 33/12 (2006.01); C09D 5/32 (2006.01); C09D 133/12 (2006.01)

CPC C08L 33/12 (2013.01) [C09D 5/32 (2013.01); C09D 133/12 (2013.01); C08L 2201/54 (2013.01); C08L 2207/53 (2013.01)]

9 Claims

1. A composition comprising an aqueous dispersion of

1) multistage polymer particles comprising:

a) a water-occluded core comprising from 20 to 60 weight percent structural units of a salt of a carboxylic acid monomer and from 40 to 80 weight percent structural units of a nonionic monoethylenically unsaturated monomer;

b) a polymeric shell having a T_gin the range of from 60° C. and 120° C.; and

c) a polymeric binder layer superposing the shell, which polymeric binder layer has a T_gof not greater than 35° C. and comprises structural units of at least one monoethylenically unsaturated monomer;

wherein the weight-to-weight ratio of structural units of monomers in the water-occluded core to the shell in the multistage polymer particles is in the range of 1:10 to 1:20;

the weight-to-weight ratio of the polymer binder to the sum of the shell and the structural units of monomers in the core in the multistage polymer particles is in the range of 1:1 to 3.5:1; and

the z-average particle size of the multistage polymer particles is in the range of from 300 nm to 750 nm;

2) from 0.01 to 0.05 weight percent, based on the weight of the composition, of a colorant that absorbs light in the range of from 500 nm to 600 nm, and

3) an opacifying inorganic pigment having a pigment volume concentration in the range of from 25% to 40%.