Coating composition for stain resistant coatings
A coating composition includes: (a) a first acrylic polymer formed from a reaction mixture including: (i) an ethylenically unsaturated monomer including an acid group or an amine group; (ii) a reactive solvent reactive with the ethylenically unsaturated monomer (i); and (iii) a second monomer reactive with ethylenically unsaturated monomer (i); and (b) a second acrylic polymer different from the first acrylic polymer, where the second acrylic polymer (b) has a Mw of at least 100,000 Da. A method of preparing such a coating composition and coatings and coated substrates formed therefrom are also disclosed. Coatings formed from the disclosed coating composition may exhibit improved stain resistance.
1. A coating composition comprising:
(a) a first acrylic polymer formed from a reaction mixture comprising:
(i) an ethylenically unsaturated monomer comprising an acid group or an amine group;
(ii) a reactive solvent reactive with the ethylenically unsaturated monomer (i); and
(iii) a second monomer reactive with ethylenically unsaturated monomer (i); and
(b) a second acrylic polymer different from the first acrylic polymer, wherein the second acrylic polymer (b) has a Mw of at least 100,000 Da.
2. The coating composition of claim 1 , wherein a volatile organic content (VOC) of the coating composition is less than 50 g/L.
3. The coating composition of claim 1 , wherein the reactive solvent (ii) is completely consumed in an addition reaction with the ethylenically unsaturated monomer (i).
4. The coating composition of claim 1 , wherein the reactive solvent (ii) is ethylenically saturated and/or comprises oxirane functionality.
5. The coating composition of claim 1 , wherein the first acrylic polymer (a) has an average particle size of less than 0.5 microns.
6. The coating composition of claim 1 , wherein the coating composition is essentially free of a non-reactive organic solvent.
7. The coating composition of claim 1 , wherein the first acrylic polymer (a) comprises 5 to 50 percent by weight based on total solids of the first acrylic polymer (a) and the second acrylic polymer (b) in the coating composition.
8. The coating composition of claim 1 , wherein the ethylenically unsaturated monomer (i) comprises an ethylenically unsaturated acid functional monomer.
9. The coating composition of claim 1 , wherein the second acrylic polymer (b) comprises a latex acrylic polymer.
10. The coating composition of claim 1 , wherein the first acrylic polymer (a) has a Mw of up to 70,000 Da.
11. The coating composition of claim 1 , wherein the first acrylic polymer (a) has a Tg of from −50° C. to 100° C.
12. A coating formed from the coating composition of claim 1 , the coating exhibiting an improved stain resistance compared to a coating formed from the same coating composition not including the first acrylic polymer (a).
13. The coating of claim 12 , wherein the coating exhibits a stain rating of at least 45 according the Stain Resistance Test Method.
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. A method of preparing a coating composition for imparting improved stain resistance comprising:
reacting to form (a) a first acrylic polymer:
(i) an ethylenically unsaturated monomer comprising an acid group or an amine group;
(ii) a reactive solvent reactive with the ethylenically unsaturated monomer (i); and
(iii) a second monomer reactive with ethylenically unsaturated monomer (i); and
mixing (b) a second acrylic polymer different from the first acrylic polymer (a) with the first acrylic polymer (a) to form a coating composition, wherein the second acrylic polymer (b) has a Mw of at least 100,000.
17. The method of claim 16 , wherein the reactive solvent (ii) is ethylenically saturated and/or comprises oxirane functionality.
18. The method of claim 16 , wherein the first acrylic polymer (a) comprises 5 to 50 percent by weight based on total solids of the first acrylic polymer (a) and the second acrylic polymer (b) in the coating composition.
19. The method of claim 16 , wherein the ethylenically unsaturated monomer (i) comprises an ethylenically unsaturated acid functional monomer.
20. The method of claim 16 , wherein a volatile organic content (VOC) of the coating composition is less than 50 g/L.