Coated substrate
The present invention relates to a substrate coated with a coating composition wherein the coating composition comprises a crosslinkable component and the crosslinkable component is a mixture of two different and optionally three different acrylic polymers. Each acrylic polymer has functional groups present that are reactive with a crosslinking component. The functional groups present on each polymer have different rates of reactivity with the crosslinking component.
1. A substrate coated by a dried and cured layer of a coating composition wherein the coating composition comprises a crosslinkable component and a crosslinking component and wherein said crosslinkable component comprises at least three polymers, a linear or branched acrylic polymer A and a linear or branched acrylic polymer B and a linear or branched acrylic polymer C wherein;
a) the linear or branched acrylic polymer A, having a weight average molecular weight in the range of from 1,000 to 40,000 and comprises in the range of from 10 to 25 percent by weight of primary hydroxy functional monomers;
b) the linear or branched acrylic polymer B, has a weight average molecular weight in the range of from 1,000 to 40,000 and comprises in the range of from 0.5 to 5 percent by weight of primary or secondary amine functional monomers; and
c) the linear or branched acrylic polymer C, has a weight average molecular weight in the range of from 1,000 to 40,000 and comprises in the range of from 5 to 25 percent by weight of secondary hydroxy functional monomers and monomers having primary hydroxy functional groups
wherein the crosslinkable component comprises polymer A in the range of from 20 to 99 percent by weight, polymer B in the range of from 1 to 20 percent by weight, and polymer C up to 75 percent by weight, wherein the percentages are based on 100 percent by weight of the polymers A, B and C in the crosslinkable component.
2. The substrate of claim 1 wherein the crosslinking component comprises at least one polyisocyanate.
3. The substrate of claim 1 wherein the primary hydroxy functional group of polymer A is from 4-hydroxybutyl acrylate or 4-hydroxybutyl methacrylate.
4. The substrate of claim 1 wherein the secondary amine functional group of polymer B is from t-butylaminoethyl acrylate or t-butylaminoethyl methacrylate.
5. The substrate of claim 1 wherein the secondary hydroxyl group of polymer C is from 2-hydroxypropyl acrylate or 2-hydroxypropyl methacrylate.
6. The substrate of claim 1 wherein the crosslinkable composition further comprises a polyester or polyether.
7. A coating composition comprising a crosslinkable component and a crosslinking component wherein said crosslinkable component comprises at least three polymers;
a) a linear or branched acrylic polymer A having a weight average molecular weight in the range of from 1,000 to 40,000 and comprising in the range of from 10 to 25 percent by weight of primary hydroxy functional monomers;
b) a linear or branched acrylic polymer B having a weight average molecular weight in the range of from 1,000 to 40,000 and comprising in the range of from 0.5 to 5 percent by weight of primary or secondary amine functional monomers; and,
a linear or branched acrylic polymer C having a weight average molecular weight in the range of from 1,000 to 40,000 and comprising in the range of from 5 to 25 percent by weight of secondary hydroxy functional monomers and monomers having primary hydroxy functional groups;
wherein the crosslinkable component comprises polymer A in the range of from 20 to 99 percent by weight, polymer B in the range of from 1 to 20 percent by weight, and polymer C up to 75 percent by weight, wherein the percentages are based on 100 percent by weight of the polymers A, B and C in the crosslinkable component.
8. The substrate of claim 1 wherein the linear or branched acrylic polymer A is substantially free from other monomers that have isocyanate reactive functional groups.
9. The substrate of claim 1 wherein polymer C is present in the range of from 45 to 75 percent by weight, wherein the percentage by weight is based on 100 percent by weight of the polymers A, B and C in the crosslinkable component.
10. A process of applying a coating composition to a substrate said process comprising;
1) forming a pot mix comprising the coating composition of claim 7 ; and
2) applying said pot mix to the substrate.