Coating composition exhibiting specific gloss properties for extreme washable coatings

Patent metadata

Field	Value
Publication number	US-11059993-B2
Application number	US-201816124808-A
Country	US
Kind code	B2
Filing date	Sep 7, 2018
Priority date	Sep 7, 2018
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

A coating composition including: an aqueous dispersion of self-crosslinkable core-shell particles, where the core-shell particles include (1) a polymeric core at least partially encapsulated by (2) a polymeric shell having urethane linkages, keto and/or aldo functional groups, and hydrazide functional groups, where the polymeric core is covalently bonded to at least a portion of the polymeric shell, and an acrylic polymer, where the acrylic polymer is non-reactive with the polymeric core and the polymeric shell. A substrate coated with a coating formed from the coating composition and a method of improving stain resistance of a substrate are also disclosed.

First claim

The invention claimed is:

1. A coating composition comprising:
an aqueous dispersion of self-crosslinkable core-shell particles, wherein the core-shell particles comprise (1) a polymeric core at least partially encapsulated by (2) a polymeric shell comprising urethane linkages, keto and/or aldo functional groups, and hydrazide functional groups, wherein the polymeric core is covalently bonded to at least a portion of the polymeric shell,
an acrylic polymer, wherein the acrylic polymer is non-reactive with the polymeric core and the polymeric shell, and
a matting agent, wherein the coating composition comprises an effective amount of the matting agent such that when the coating composition is applied to a substrate and dried to form a coating, the coating exhibits a 60° gloss below 20 units and an 85° sheen below 35 units.

2. The coating composition of claim 1 , wherein the polymeric core comprises an addition polymer derived from ethylenically unsaturated monomers.

3. The coating composition of claim 2 , wherein the ethylenically unsaturated monomers comprise a (meth)acrylate monomer, a vinyl monomer, and/or a combination thereof.

4. The coating composition of claim 1 , wherein the polymeric shell comprises a water dispersible group.

5. The coating composition of claim 1 , wherein the core-shell particles are formed from a mixture of reactants comprising: (a) isocyanate-functional ethylenically unsaturated polyurethane prepolymers; (b) a Michael addition reaction product of ethylenically unsaturated monomers comprising a keto and/or aldo functional group, and a compound comprising at least two amino groups; (c) a hydrazide functional component; and (d) ethylenically unsaturated monomers.

6. The coating composition of claim 1 , wherein the polymeric core is completely free of keto and/or aldo functional groups.

7. The coating composition of claim 1 , wherein the acrylic polymer is added to the aqueous dispersion after formation of the core-shell particles.

8. The coating composition of claim 1 , comprising 10-50 wt % of the core-shell particles and 50-90 wt % of the acrylic polymer, based on total resin solids.

9. The coating composition of claim 1 , wherein the self-crosslinkable core-shell particles further comprise a fluorine-containing group and/or a silicon-containing group bonded to the polymeric shell.

10. The coating composition of claim 1 , wherein the polymeric core comprises a Tg of 0° C. to 50° C.

11. The coating composition of claim 1 , further comprising a rheology modifier.

12. The coating composition of claim 1 , further comprising an inorganic pigment and/or filler.

13. The coating composition of claim 1 , wherein when the coating composition is applied to a substrate and dried to form a coating, the coating exhibits an improved stain resistance compared to the same coating composition not including the core-shell particles.

14. A substrate at least partially coated with a coating formed from the coating composition of claim 1 .

15. The substrate of claim 14 , wherein the substrate comprises an architectural component.

16. The substrate of claim 14 , wherein the substrate is non- metallic.

17. A method of improving stain resistance of a substrate comprising:
preparing a coating composition by:
preparing an aqueous dispersion of self-crosslinkable core-shell particles dispersed in an aqueous medium, wherein the core-shell particles comprise (1) a polymeric core at least partially encapsulated by (2) a polymeric shell comprising urethane linkages, keto and/or aldo functional groups, and hydrazide functional groups wherein the polymeric core is covalently bonded to at least a portion of the polymeric shell;
adding an acrylic polymer to the aqueous dispersion, wherein the acrylic polymer is non-reactive with the polymeric core and the polymeric shell; and
adding a matting agent to the coating composition, wherein the coating composition comprises an effective amount of the matting agent such that when the coating composition is applied to a substrate and dried to form a coating, the coating exhibits a 60° gloss below 20 units and an 85° sheen below 35 units; and

applying the coating composition to a substrate.

18. The method of claim 17 , wherein the acrylic polymer is added to the aqueous dispersion after formation of the core-shell particles.

19. The method of claim 17 , wherein the coating composition comprises 10-50 wt % of the core-shell particles and 50-90 wt % of the acrylic polymer, based on total resin solids.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Wang Maria
• Swarup Shanti
• Wang Yu
• Xu Xiangling

Classifications

• C09D7/42

  Gloss-reducing agents · CPC title

• C09D133/08

  Homopolymers or copolymers of acrylic acid esters · CPC title

• C08G18/6644

  having at least three hydroxy groups · CPC title

• C08K3/346

  Clay · CPC title

• C08G18/3231

  Hydrazine or derivatives thereof · CPC title