Paper coating composition

Patent metadata

Field	Value
Publication number	US-10184062-B2
Application number	US-201615366100-A
Country	US
Kind code	B2
Filing date	Dec 1, 2016
Priority date	Dec 4, 2015
Publication date	Jan 22, 2019
Grant date	Jan 22, 2019

Abstract

The present invention relates to a coating composition comprising an aqueous dispersion of a binder and first and second core-shell polymer particles having aqueous neutralized acid cores, wherein the dry bulk density of the first core-shell polymer particles is in the range of 0.25 to 0.5 g/mL; and the dry bulk density of the second core-shell polymer particles is in the range of 0.30 to 0.90 g/mL. The composition of the present invention is useful as an undercoat layer for a thermosensitive recording material.

First claim

The invention claimed is:

1. A coating composition comprising an aqueous dispersion of a binder and first and second core-shell polymer particles having aqueous neutralized acid cores, wherein
a) the first core-shell polymer particles have a diameter in the range of from 1.0 μm to 1.8 μm;
b) the second core-shell polymer particles have a diameter in the range of from 0.25 μm to 1.0 μm;
c) the number ratio of the second to the first core-shell polymer particles is in the range of from 1:1 to 20:1;
d) the diameter of the second core-shell polymer particles is in the range of from 15 to 65% of the diameter of the first core-shell polymer particles;
e) the dry bulk density of the first core-shell polymer particles is in the range of 0.25 to 0.5 g/mL; and
f) the dry bulk density of the second core-shell polymer particles is in the range of 0.30 to 0.90 g/mL.

2. The coating composition of claim 1 wherein the first core-shell polymer particles have a diameter in the range of from 1.2 μm to 1.8 μm; and the second core-shell polymer particles have a diameter in the range of from 0.3 μm to 0.8 μm; wherein the number ratio of the second to the first core-shell polymer particles is in the range of from 2:1 to 15:1; wherein the diameter of the second core-shell polymer particles in the range of from 20 to 40% of the diameter of the first core-shell polymer particles.

3. The coating composition of claim 2 wherein the first core-shell polymer particles have a diameter in the range of from 1.3 μm to 1.7 μm; and the second core-shell polymer particles have a diameter in the range of from 0.35 μm to 0.6 μm; wherein the number ratio of the second to the first core-shell polymer particles is in the range of from 3:1 to 12:1; wherein the diameter of the second core-shell polymer particles in the range of from 25 to 33% of the diameter of the first core-shell polymer particles.

4. The coating composition of claim 3 the second core-shell polymer particles have a diameter in the range of from 0.4 μm to 0.5 μm; wherein the number ratio of the second to the first core-shell polymer particles is in the range of from 4:1 to 10:1; wherein the diameter of the second core-shell polymer particles is in the range of from 27 to 30% of the diameter of the first core-shell polymer particles; and wherein the first core-shell polymer particles have a diameter in the range of from 1.4 μm to 1.6 μm.

5. The coating composition of claim 2 wherein the dry bulk density of the first core-shell polymer particles is in the range of 0.30 to 0.45 g/mL; and the dry bulk density of the second core-shell polymer particles is in the range of 0.40 to 0.80 g/mL.

6. The coating composition of claim 3 wherein the dry bulk density of the first core-shell polymer particles is in the range of 0.35 to 0.40 g/mL; and the dry bulk density of the second core-shell polymer particles is in the range of 0.50 to 0.75 g/mL.

7. The coating composition of claim 4 wherein the dry bulk density of the first core-shell polymer particles is in the range of 0.35 to 0.40 g/mL; and the dry bulk density of the second core-shell polymer particles is in the range of 0.55 to 0.65 g/mL.

8. The coating composition of claim 1 wherein the first and second core-shell polymer particles have a total pigment volume concentration in the range of from 50 to 98%.

Assignees

• Dow Global Technologies Llc
• Rohm & Haas

Inventors

• Einsla Brian R
• Ginzburg Valeriy V
• Li Lanfang
• Roper Iii John A
• Smith Rebecca
• Yang Jian

Classifications

• C09D7/69

  Particle size larger than 1000 nm · CPC title

• B41M2205/38

  Intermediate layers; Layers between substrate and imaging layer · CPC title

• B41M2205/04

  Direct thermal recording [DTR] · CPC title

• C09D7/68

  Particle size between 100-1000 nm · CPC title

• D21H19/58

  Polymers or oligomers of diolefins, aromatic vinyl monomers or unsaturated acids or derivatives thereof · CPC title