Soil and dirt repellent powder coatings
A dirt repellant panel coated with a powder coating composition that includes a polymeric binder and an anionic fluorosurfactant present in an amount ranging from about 0.1 wt. % to about 4 wt. %.
1. A powder coating composition comprising a blend of
a binder comprising a polymer resin that is substantially free of fluoro-carbon groups; and
a pigment that is pre-treated with an anionic fluorosurfactant having a pH ranging from 1 to 6;
wherein the blend is substantially free of solvent.
2. The powder coating composition of claim 1 , wherein the anionic fluorosurfactant is present in an amount ranging from 0.05 wt. % to 4 wt. % based on the total weight of the powder coating composition.
3. The powder coating composition of claim 2 wherein the anionic fluorosurfactant is present in an amount ranging from 0.7 wt. % to 3.0 wt. % based on the total weight of the powder coating.
4. The powder coating composition of claim 1 wherein the anionic fluorosurfactant comprises a phosphate group substituent.
5. The powder coating composition of claim 1 wherein the anionic fluorosurfactant has a melting point ranging from 50° C. to 70° C.
6. The powder coating composition according to claim 1 , wherein the blend further comprises a cross-linker.
7. The powder coating composition of claim 6 wherein the polymer resin comprises hydroxyl-terminated polyester resin and the cross-linker comprises a blocked polyisocyanate.
8. The powder coating composition of claim 6 wherein the polymer resin is selected from carboxylated polyester resin and a glycidyl-functional acrylic polymer resin, and the cross-linker comprises a hydroxyl-functional compound.
9. The powder coating composition of claim 1 wherein the polymer resin has a glass transition temperature ranging from 45° C. to 90° C.
10. The powder coating composition of claim 1 wherein the pigment is present in an amount ranging from 10 wt. % to 30 wt. % based on the total weight of the powder coating composition.
11. A dirt repellant panel comprising:
a substrate; and
a powder coating applied to the substrate, the powder coating formed from a mixture that is substantially free of solvent, the mixture comprising:
a binder comprising a polymer resin that is substantially free of fluoro-carbon groups; and
a pigment;
wherein the pigment is pre-treated with an anionic fluorosurfactant having a pH ranging from 1 to 6.
12. The dirt repellant panel of claim 11 wherein the anionic fluorosurfactant comprises a phosphate group substituent and a C6 to C16 perfluoroalkylethyl group.
13. The direct repellant panel of claim 11 , wherein the anionic fluorosurfactant is present in an amount ranging from 0.05 wt. % to 4 wt. % based on the total weight of the powder coating.
14. The dirt repellant panel of claim 11 wherein the pigment is present in an amount ranging from 10 wt. % to 30 wt. % based on the total weight of the powder coating.
15. The dirt repellant panel of claim 11 wherein the powder coating further comprises:
a cross-linker selected from the group consisting of a glycidyl-functional compound, a hydroxyl-functional compound, and a polyisocyanate; and
wherein the polymer resin is selected from the group consisting of hydroxyl-terminated polyester resin, carboxylated polyester resin, and a combination thereof.
16. The dirt repellant panel of claim 11 wherein the mixture is free of volatile organic solvent and has solids content of 100%.
17. The dirt repellant panel of claim 11 wherein the powder coating has a thickness ranging from 45 μm to 120 μm.