High performance silicon based coatings
Provided herein is a method of coating a surface. A silicon-based coating composition is coated onto a surface. The composition comprises 5% to 80% polysilazane, 20% to 60% polysiloxane, and polysilane of a formula (R 1 R 2 Si) n , wherein n is greater than 1, and wherein R 1 and R 2 are the same or different and are chosen from alkyl, alkenyl, cycloalkyl, alkylamino, aryl, aralkyl, or alkylsilyl, which polysilane has a weight average molecular weight of more than 50,000, and optionally organic solvent. The coating is cured ambiently to provide a non-ceramic clear coating having a thickness ranging between 0.1 mil and 1.5 mil, a hardness ranging between 2H and 9H in accordance with ASTM 3363 for film hardness by pencil test, and a kinetic coefficient of friction between 0.03 and 0.04. Also provided are silicon-based coating compositions and cured coatings from those compositions using the provided method.
1. A silicon-based coating composition comprising:
polysilazane;
polysiloxane; and
polysilane comprising a formula (R 1 R 2 Si) n , wherein n is greater than 1, and wherein R 1 and R 2 are the same or different and are chosen from alkyl, alkenyl, cycloalkyl, alkylamino, aryl, aralkyl, or alkylsilyl, which polysilane has a weight average molecular weight of more than 50,000.
2. The composition of claim 1 , wherein the polysilazane has the formula (CH 3 ) 3 Si—NH—[(CH 3 ) 2 Si—NH] n —Si(CH 3 ) 3 , wherein n is greater than 1.
3. The composition of claim 1 , comprising about 5% (w/w of the total composition) to about 80% (w/w of the total composition) polysilazane.
4. The composition of claim 3 , comprising 15% (w/w of the total composition) to 20% (w/w of the total composition) polysilazane.
5. The composition of claim 1 , wherein the polysiloxane has the formula [SiOR 1 R 2 ] n , wherein n is greater than 1, and each R 1 and R 2 is methyl.
6. The composition of claim 1 , comprising about 20% (w/w of the total composition) to about 60% (w/w of the total composition) polysiloxane.
7. The composition of claim 6 , comprising 25% (w/w of the total composition) to 30% (w/w of the total composition) polysiloxane.
8. The composition of claim 1 , wherein the polysilane comprises the formula [R 1 R 2 Si—R 1 R 2 Si] n , wherein n is greater than 1, and each R 1 and R 2 is methyl.
9. The composition of claim 1 , comprising about 1% polysilane.
10. The composition of claim 1 , further comprising 15% (w/w of the total composition) to 60% (w/w of the total composition) organic solvent.
11. The composition of claim 10 , comprising about 55% (w/w of the total composition) to about 60% (w/w of the total composition) organic solvent.
12. The composition of claim 1 , further comprising an organic solvent chosen from tert-butyl acetate, isopropyl acetate, methyl acetate, aliphatic hydrocarbon, and mixtures thereof.
13. A method of coating a surface, which method comprises:
a. coating onto a surface the silicon-based coating composition of claim 1 ; and
b. curing the coating ambiently to provide a non-ceramic clear coating.
14. The method of claim 13 , wherein the coating step comprises wiping the coating composition onto the surface as a uniform wet film.
15. The method of claim 13 , wherein the curing step occurs for at least 15 minutes at room temperature.
16. The method of claim 13 , further comprising pre-conditioning the surface to be a clean surface before the coating step.
17. The method of claim 13 , wherein the surface is porous and comprises a material chosen from an epoxy resin, a composite material, and mixtures thereof.
18. The method of claim 17 , wherein the surface comprises an epoxy resin which comprises an amine hardener.
19. A cured coating formed from the method of claim 13 .
20. The cured coating of claim 19 , having a thickness ranging between 0.1 mil and 1.5 mil.
21. The cured coating of claim 19 , having a hardness ranging between 2H and 9H in accordance with ASTM 3363 for film hardness by pencil test.
22. The cured coating of claim 19 , having cured coating has a kinetic coefficient of friction between 0.03 and 0.04.
23. The composition of claim 1 , comprising about 1% (w/w of the total composition) to about 5% (w/w of the total composition) polysilazane.
24. The composition of claim 1 , comprising between 0% (w/w of the total composition) and 1% (w/w of the total composition) polysiloxane.
25. The composition of claim 1 , comprising about 1% (w/w of the total composition) to about 5% (w/w of the total composition) polysilane.
26. The composition of claim 1 , comprising about 1% (w/w of the total composition) to about 5% (w/w of the total composition) polysilazane; between 0% (w/w of the total composition) and 1% (w/w of the total composition) polysiloxane; and about 1% (w/w of the total composition) to about 5% (w/w of the total composition) polysilane.
27. A method of coating a surface, which method comprises:
a. coating onto a surface the silicon-based coating composition of claim 26 ; and
b. curing the coating ambiently to provide a non-ceramic clear coating.
28. A cured coating formed from the method of claim 27 .