Multi component coating composition

Abstract

The present invention is directed to a multi component coating composition that includes a crosslinkable, crosslinking and catalyst components. The catalyst component includes organo zinc cocatalysts, organo tin catalysts, and carboxylic acids. The catalyst component provides long pot life to a pot mix obtained by mixing the aforementioned with components while simultaneously providing a coating resulting from the pot mix with desired coating properties, such as desired early hardness of a coating resulting from a relatively low temperature baking cure cycle.

Description

Claims

1. A coating composition comprising a crosslinkable component, a crosslinking component and a catalyst component, wherein said crosslinkable component comprises one or more crosslinkable polymers;wherein said crosslinking component comprises one or more polyisocyanates having on an average two or more isocyanate groups and;wherein said catalyst component consists essentially of one or more organo zinc cocatalysts, one or more organo tin catalysts, and one or more C1 to C8 carboxylic acids.

2. The coating composition of claim 1 wherein said zinc cocatalyst is a reaction product of zinc oxide with C1 to C12 carboxylic acids, hydroxy C1 to C12 carboxylic acids, or a combination thereof.

3. The coating composition of claim 2 wherein said zinc cocatalyst is selected from the group consisting of zinc octoate, zinc napthenate, zinc formate, zinc acetate, zinc propionate, zinc acetylacetonate, zinc lactate, and a combination thereof.

4. The coating composition of claim 1 wherein said organo tin catalyst is dialkyl tin carboxylate of aliphatic carboxylic acid.

5. The coating composition of claim 1 wherein said organo tin catalyst is selected from the group consisting of dibutyl tin dilaurate, dibutyl tin dioctoate, dibutyl tin diacetate, and a combination thereof.

6. The coating composition of claim 1 wherein said C1 to C8 carboxylic acid is acetic acid.

7. The coating composition of claim 1 wherein weight percentage of zinc cocatalyst ranges from 0.01 percent to 1 percent, wherein weight percentage of organo tin catalysts ranges from 0.003 percent to 0.1 percent, and wherein weight percentage of carboxylic acids component ranges from 0.01 percent to 1.5 percent all weight percentages being based on the crosslinkable, crosslinking and catalyst component solids.

8. The coating composition of claim 1 wherein said crosslinkable polymer is a hydroxy functional acrylic polymer, hydroxy functional polyester or a combination thereof.

9. The coating composition of claim 1 or 8 wherein said crosslinkable polymer has GPC weight average molecular weight ranging from 200 to 100,000.

10. The coating composition of claim 1 or 8 wherein said crosslinkable polymer has a Tg ranging from −70° C. to 100° C.

11. The coating composition of claim 8 wherein said hydroxy functional acrylic polymer is polymerized from a monomer mixture comprising hydroxy C1 to C8 alkyl(meth)acrylate; and styrene, α-methyl styrene, C1 to C8 alkyl(meth)acrylate, C3 to C12 cycloalkyl (meth)acrylate, or a combination thereof.

12. The coating composition of claim 8 wherein said hydroxy functional polyester is prepared by polymerizing one or more polyols and one or more lactones to provide said polyester with on average, two or more terminal hydroxyl groups.

13. The coating composition of claim 8 wherein said hydroxy functional polyester is prepared by: (a) polymerizing one or more polyols and one or more dicarboxylic acids, anhydrides of said dicarboxylic acids or a combination thereof to form an intermediate; and(b) contacting said intermediate with a monofunctional C2 to C8 alkylene oxide, a glycidyl ester, or a combination thereof.

14. The coating composition of claim 8 wherein said hydroxy functional polyester is prepared by: (a) polymerizing one or more polyols and one or more dicarboxylic acids, anhydrides of said dicarboxylic acids or a combination thereof to form an intermediate; and(b) contacting said intermediate with a caprolactone.

15. The coating composition of claim 1 wherein ratio of said isocyanate groups to said hydroxyl group ranges from 0.7 to 1.5.

16. The coating composition of claim 1 wherein said polyisocyanate is a trimer of isophorone diisocyanate, a trimer of hexamethylene diisocyanate, or a combination thereof.

17. The coating composition of claim 1 formulated as a two-pack composition wherein said crosslinkable component and said crosslinking component are stored in separate containers and wherein said catalyst component is included in said container containing said crosslinkable component or in said container containing said crosslinking component.

18. The coating composition of claim 1 formulated as a two-pack composition wherein said crosslinkable component and said crosslinking component are stored in separate containers and wherein a portion of said catalyst component is included in said container containing said crosslinkable component and a remainder of said catalyst component is included in said container containing said crosslinking component.

19. The coating composition of claim 1, 17 or 18 formulated as a refinish or OEM clear coating composition.

20. The coating composition of claim 1,17, or 17 formulated as a refinish or OEM basecoat composition.

21. The coating composition of claim 1,17, or 17 formulated as a refinish or OEM primer composition.

22. The coating composition of claim 20 wherein said crosslinkable component further comprises dispersed pigments.

23. The coating composition of claim 1 wherein when said crosslinkable, crosslinking and catalyst components are mixed to form a pot mix, said pot mix having a shelf life ranging from 20 minutes to four hours when said coating composition has a VOC of 0.52 kilograms per liter.