Glass articles with adhesion and stain resistant non-stick coatings
View Patent ↗The invention provides a non-stick coating for glass cookware that has good adhesion and stain resistance while maintaining the abrasion resistance of the non-stick coating. The non-stick coating comprises a base coat that contains fluoropolymer and colloidal silica and an overcoat comprising one or more polymer layers containing inorganic filler film hardener.
1. A coated article comprising:
a) a glass substrate having a surface, and
b) a stain resistant, non-stick coating adhered to the surface of said substrate, wherein said non-stick coating comprises:
i) a base coat comprising fluoropolymer and colloidal silica, and
ii) an overcoat comprising a primer layer, one or more intermediate layers and a topcoat, and wherein said overcoat comprises one or more polymer layers containing ceramic particles having an aspect ratio of not greater than 2.5; and
wherein the amount of colloidal silica present in the base coat is from 20% to 35% by weight of the total solids.
2. The coated article of claim 1 , wherein said coated article is cookware.
3. The coated article of claim 1 , wherein said ceramic particles comprise a Knoop hardness of greater than 1200.
4. The coated article of claim 1 , wherein said ceramic particles comprise an average particle size of greater than 10 micrometers.
5. The coated article of claim 1 , wherein said ceramic particles comprises silicon carbide.
6. The coated article of claim 1 , wherein said base coat has a dry film thickness of up to 8 microns.
7. The coated article of claim 1 , wherein said glass substrate is borosilicate glass.
8. The coated article of claim 1 , wherein said glass substrate is roughened prior to applying of the base coat.
9. The coated article of claim 8 , wherein said glass substrate has an average roughness greater than 2 microns.
10. The coated article of claim 9 , wherein said glass substrate has been roughened by grit blasting.
11. The coated article of claim 1 , wherein said overcoat comprises at least one polymer layer comprising fluoropolymer.
12. The coated article of claim 1 , wherein said primer comprises fluoropolymer.
13. The coated article of claim 1 , wherein said one or more intermediate layers comprises fluoropolymer.
14. The coated article of claim 1 , wherein said overcoat further comprises polymer binder.
15. The coated article of claim 12 , wherein said primer further comprises polymer binder.
16. The coated article of claim 13 , wherein one or more of said intermediate layers further comprises polymer binder.
17. The coated article of claim 14 , wherein said coated article has a stain resistance sufficient to pass the Accelerated Roasted Chicken Test.
18. The coated article of claim 1 , wherein said coated article passes 100 cycles of the Dishwasher Adhesion Test.
19. The coated article of claim 1 , wherein said primer comprises silicon carbide and polyamideimide.
20. The coated article of claim 15 , wherein said primer further comprises silicon carbide.
21. The coated article of claim 1 , wherein the primer layer or one or more intermediate layers contains ceramic particles.
22. The coated article of claim 1 , wherein the primer layer and one or more intermediate layers contains ceramic particles.
23. The coated article of claim 1 , wherein said base coat further comprises silicone resin.
24. The coated article of claim 1 , wherein said base coat further comprises silicone resin in an amount up to 3 weight percent in the dry base coat.