Latex polymer for improved paint washability
View Patent ↗The present invention is directed to a coating composition or paint comprising a polymer system including one or more latex polymers, wherein the acid content and molecular weight of the latex polymers are balanced to provide a coating composition that demonstrates optimal performance characteristics of washability or stain resistance, especially when used in a flat finish paint.
1. A coating composition, comprising:
a polymer system comprising one or more latex polymers, wherein at least about 10% up to 30% by weight of the polymer system includes at least one polymer having a molecular weight of about 10,000 to about 40,000 and an acid percent of about 5 to 10, wherein the coating composition has a pigment volume concentration (PVC) of about 30 to 55.
2. The coating composition of claim 1 , wherein the one or more latex polymers include one or more polymerization products of one or more ethylenically unsaturated monomers.
3. The coating composition of claim 1 , wherein the one or more latex polymers include one or more polymerization products of one or more ethylenically unsaturated monomers selected from the group consisting of acrylic acid, C 1 -C 8 esters of acrylic acid, substituted C 1 -C 8 esters of acrylic acid, methacrylic acid, C 1 -C 8 ester of methacrylic acid, substituted C 1 -C 8 esters of methacrylic acid, styrene, a-methyl styrene, vinyl toluene, vinyl acetate, vinyl propionate, allyl methacrylate, and mixtures thereof.
4. The coating composition of claim 1 , wherein the one or more latex polymers include one or more polymerization products of one or more acrylic monomers.
5. The coating composition of claim 1 , wherein the one or more latex polymers comprise one or more alkali-soluble support polymers.
6. The coating composition of claim 1 , wherein the polymer system comprises:
a first latex polymer comprising about 50 to 85 wt % of the polymer system, based on the total weight of the system; and
a second latex polymer comprising about 15 to 50 wt % of the polymer system, based on the total weight of the system.
7. The coating composition of claim 1 , wherein the polymer system comprises a first latex polymer and a second latex polymer, wherein the ratio of the first latex polymer to the second latex polymer is from 10:90 to 90:10.
8. The coating composition of claim 1 , wherein the at least one polymer being at least about 10% up to 30% by weight of the polymer system has a molecular weight of about 20,000 to 30,000.
9. The coating composition of claim 1 , wherein the at least one polymer being at least about 10% up to 30% by weight of the polymer system has a molecular weight of about 15,000 to about 25,000.
10. The coating composition of claim 1 , wherein the at least one polymer being at least about 10% up to 30% by weight of the polymer system has a theoretical acid value of about 25 to about 75.
11. The coating composition of claim 1 , wherein the at least one polymer being at least about 10% up to 30% by weight of the polymer system has a theoretical acid value of about 30 to about 70.
12. The coating composition of claim 1 , wherein the composition exhibits a washability rating of at least 8.
13. The coating composition of claim 1 , wherein the polymer system comprises a polymerization product from styrene, butyl acrylate, 2-(acetoacetoxy)ethyl methacrylate, methyl methacrylate, and butyl methacrylate.
14. The coating composition of claim 1 , wherein the polymer system comprises at least one copolymer derived from styrene, butyl acrylate, 2-(acetoacetoxy)ethyl methacrylate, methyl methacrylate, and butyl methacrylate.
15. The coating composition of claim 1 , wherein the coating composition exhibits a washability rating of at least 6.
16. The coating composition of claim 1 , wherein the coating composition exhibits a washability rating of at least 7.
17. The coating composition of claim 1 , wherein at least about 15% up to 30% by weight of the polymer system includes the at least one polymer.
18. The coating composition of claim 1 , wherein at least about 15% up to 25% by weight of the polymer system includes the at least one polymer.
19. The coating composition of claim 1 , wherein the at least one polymer having the molecular weight of about 10,000 to about 40,000 and the acid percent of about 5 to 10 is methacrylic acid.