Non-stick finish

Abstract

A non-stick coating on a substrate is provided wherein the coating comprises an overcoat and a primer adhering the overcoat to the substrate, the overcoat comprising fluoropolymer and an effective amount of ceramic particles, preferably at least 3 wt % based on the combined weight of the fluoropolymer and the ceramic particles in the overcoat, said ceramic particles having an average particle size of at least about 10 micrometers to increase the abrasion resistance of said coating as determined by the dry SBAR method.

Description

Claims

1. A substrate having non-stick coating thereon comprising an overcoat and a primer adhering said overcoat to said substrate, said overcoat comprising fluoropolymer and an effective amount of ceramic particles having an average particle size of at least about 10 micrometers to increase the abrasion resistance of said coating as determined by the dry SBAR method.

2. The substrate of claim 1 wherein said amount of said ceramic particles is at least about 3 wt % based on the combined weight of said ceramic particles and said fluoropolymer in said overcoat.

3. The substrate of claim 1 wherein said primer also contains ceramic particles having an average size of at least about 10 micrometers.

4. The substrate of claim 1 wherein said primer comprises adhesion promoter and optionally, fluoropolymer.

5. The substrate of claim 4 wherein said adhesion promoter is selected from the group consisting of polyamideimide, polyether sulfone, and polyphenylene sulfide.

6. The substrate of claim 1 wherein said primer is substantially free of fluoropolymer.

7. The substrate of claim 1 wherein said non-stick coating includes a topcoat which comprises fluoropolymer and is free of said ceramic particles.

8. The substrate of claim 7 wherein said overcoat has a thickness which is less than the major dimension of said ceramic particles.

9. The substrate of claim 3 wherein said non-stick coating includes a topcoat which comprises fluoropolymer and is free of said ceramic particles.

10. The substrate of claim 1 wherein additionally inorganic film hardener is present in at least one of said primer and said overcoat, said inorganic film hardener having an average particle size of less than about 5 micrometers.

11. The substrate of claim 1 wherein the thickness of said overcoat is at least about 50% greater than the thickness of said primer.

12. The substrate of claim 1 wherein said primer has a thickness of about 0.2 to 0.6 mils (5.1 to 16 micrometers).

13. The substrate of claim 1 wherein said overcoat contains adhesion promoter in an amount of up to about 10 wt % based on the weight of said fluoropolymer.

14. The substrate of claim 13 wherein said amount of said adhesion promoter is up to about 8 wt %.

15. The substrate of claim 13 wherein said adhesion promoter is selected from the group consisting of polyamideimide, polyether sulfone, and polyphenylene sulfide.

16. The substrate of claim 1 wherein said overcoat is substantially free of adhesion promoter.

17. The substrate of claim 1 wherein said primer and overcoat are sequentially applied to said substrate from a liquid medium.

18. The substrate of claim 18 wherein said liquid medium comprises water.