High performance silicon based coatings
Provided herein is a silicon based coating formed from a mixture of constituents. The mixture comprises from about 5% (w/w of the mixture) to about 80% (w/w of the mixture) polysilazane, from about 0% (w/w of the mixture) to about 60% (w/w of the mixture) polysiloxane, and from about 8% (w/w of the mixture) to about 80% (w/w of the mixture) 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. The coating has a thickness ranging between about 0.1 mil and about 1.5 mil, a hardness ranging between about 2H and about 9H in accordance with ASTM 3363 for film hardness by pencil test, and a kinetic coefficient of friction between about 0.03 and about 0.04.
1. A silicon based coating formed from a mixture of constituents comprising:
from about 5% (w/w of the mixture) to about 80% (w/w of the mixture) polysilazane,
from about 0% (w/w of the mixture) to about 60% (w/w of the mixture) polysiloxane, and
from about 8% (w/w of the mixture) to about 80% (w/w of the mixture) 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, and wherein the polysilane has a weight average molecular weight of more than 50,000;
which coating has a thickness ranging between about 0.1 mil and about 1.5 mil, a hardness ranging between about 2H and about 9H in accordance with ASTM 3363 for film hardness by pencil test, and a kinetic coefficient of friction between about 0.03 and about 0.04.
2. The silicon based coating of claim 1 , wherein the polysilazane is of a formula [H 2 Si—NH] n , and wherein the polysilazane is branched, linear or cyclic polymers, with n greater than 1.
3. The silicon based coating of claim 1 , comprising about 5% (w/w of the mixture) to about 60% (w/w of the mixture) polysiloxane.
4. The silicon based coating of claim 3 , wherein the polysiloxane is of a formula [SiOR 1 R 2 ] n , wherein R 1 and R 2 are the same or different and are chosen from alkyl, aromatic hydrocarbon, organoamine, fluorinated hydrocarbon, alkoxy, mercapto, chloro, cyano, or allyl, and wherein n is greater than 1.
5. The silicon based coating of claim 4 , wherein the polysiloxane is of a formula CH 3 [Si(CH 3 ) 2 O] n Si(CH 3 ) 3 (polydimethylsiloxane), and wherein n is greater than 1.
6. The silicon based coating of claim 3 , wherein the polysiloxane comprises polydimethylsiloxane in isopropyl acetate solvent.
7. The silicon based coating of claim 1 , wherein both R 1 and R 2 are alkyl.
8. The silicon based coating of claim 7 , wherein both R 1 and R 2 are methyl.
9. The silicon based coating of claim 1 , the mixture further comprising one or more organic solvents.
10. The silicon based coating of claim 9 , wherein the organic solvent includes acetic esters selected from the group consisting of methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, ethylhexyl acetate, n-butyl acetate, tert-butyl acetate, amyl acetate, pentyl acetate, 2-methyl butyl acetate, and isoamyl acetate.
11. The silicon based coating of claim 10 , wherein the organic solvent further includes hydrocarbons selected from the group consisting of hexane, heptane, benzene, toluene, and branched-chain alkanes (isoparaffins).
12. The silicon based coating of claim 1 , the mixture further comprising one or more additives.
13. The silicon based coating of claim 12 , wherein the additive is chosen from pigments, matting agents, fillers, flow control agents, dry flow additives, anticratering agents, surfactants, texturing agents, light stabilizers, photosensitizers, wetting agents, anti-static agents, anti-oxidants, plasticizers, opacifiers, stabilizers, degassing agents, corrosion inhibitors, ceramic microspheres, slip agents, dispersing agents, and surface altering additives.
14. The silicon based coating of claim 1 , the mixture further comprising a curing catalyst.
15. The silicon based coating of claim 1 , the mixture further comprising a curing hardener.
16. The silicon based coating of claim 1 , wherein the polysilazane is in n-butyl acetate or tert-butyl acetate solvent.
17. The silicon based coating of claim 1 , wherein the polysilane is in a mixture of pentyl acetate, 2-methyl butyl acetate, isoamyl acetate and isoparaffin solvent.
18. The silicon based coating of claim 1 , the mixture comprising:
a. 45% to 55% (w/w of the mixture) polysilazane;
b. 20% to 30% (w/w of the mixture) 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, and wherein the polysilane has a weight average molecular weight of more than 50,000;
c. 10% to 45% (w/w of the mixture) organic solvent; and
d. 0% to 2% (w/w of the mixture) additives.
19. The silicon based coating of claim 1 , which coating is non-ceramic.