Copolycarbonates, their derivatives and the use thereof in silicone hardcoat compositions
View Patent ↗Disclosed herein are novel copolycarbonates containing repeating units A and B respectively of the formulae: (A) —[R 1 OC(═O)O]—, and (B) —[(R 2 O)n-C(═O)—O]—, wherein the molar ratio of units (A) to units (B) is in the range of from about 9:1 to about 1:9, and wherein R 1 is a divalent C8 to C12 alicyclic group, and R 2 is ethylene or propylene, and n is an integer ranging from 4 to 40. Also disclosed are silicone hardcoat compositions containing the copolycarbonates and their derivatives. Upon cure, these silicone hardcoat compositions exhibit improved flexibility as compared to that of the conventional hardcoats while at the same time maintain the abrasion resistance of conventional silicone hardcoats.
1. A copolycarbonate comprising repeating units A and B respectively of the formulae:
wherein the molar ratio of units (A) to units (B) is in the range of from about 9:1 to about 1:9, and wherein R 1 is a divalent C8 to C12 alicyclic group, R 2 is a divalent group selected from the group consisting of ethylene and propylene, n is an integer ranging from 4 to 40.
2. The copolycarbonate of claim 1 comprising terminal groups, wherein each terminal group is a member selected from the group consisting of a hydroxyl group, and a substituted silyl group of the formula
wherein R 1 is a monovalent hydrocarbon residue having 1 to 10 carbon atoms, each Y is independently a member selected from the group consisting of a halogen atom, an alkoxy group having 1 to 10 carbon atoms, and an acyloxy group having 1 to 10 carbon atoms, and a is a number having a value of from 1 to 3.
3. The copolycarbonate of claim 2 wherein substantially all of the terminal groups are hydroxyl groups.
4. The copolycarbonate of claim 2 wherein substantially all of the terminal groups are silyl groups of Formula (I).
5. The copolycarbonate of claim 1 wherein each occurrence of R 1 is independently
6. A polyurethane obtained by reaction of a polyisocyanate and a copolycarbonate diol of claim 3 .
7. The polyurethane of claim 6 wherein the polyisocyanate is a diisocyanate represented by
OCN—R 4 —NCO,
wherein R 4 is selected from
8. The polyurethane of claim 6 wherein the polyurethane is hydroxyl-terminated or isocyanate-terminated.
9. The polyurethane of claim 8 wherein the polyurethane is silylated with at least one compound selected from the group consisting of aminosilane and isocyanatosilane.
10. The polyurethane of claim 9 wherein the aminosilane is of the general formula:
wherein R 6 is hydrogen or an alkyl group of from about 1 to about 10 carbon atoms, R 7 is a divalent alkylene group of from about 1 to about 10 carbon atoms, R 2 and R 3 each independently is an alkyl group of from about 1 to about 6 carbon atoms or an aryl group of from about 6 to about 8 carbon atoms, and b has a value of 0, 1 or 2; and
the isocyanatosilane is of the general formula:
wherein R 8 is a divalent alkylene group of from about 1 to about 10 carbon atoms, R 4 and R 5 each independently is an alkyl group of from about 1 to about 6 carbon atoms or an aryl group of from about 6 to about 8 carbon atoms, and c has a value of 0, 1 or 2.
11. A coating composition comprising a copolycarbonate of claim 1 .
12. The coating composition of claim 11 further comprising: a partial condensate of an organoalkoxysilane; and colloidal silica.
13. The coating composition of claim 12 wherein the organoalkoxysilane is of the formula (R 9 ) d Si(OR 10 ) 4-d , wherein R 9 is a C1-C6 monovalent hydrocarbon radical, R 10 is an R 9 or a hydrogen radical, and d is 0, 1 or 2.
14. The coating composition of claim 13 wherein the organoalkoxysilane is selected from the group consisting of methyltrimethoxysilane, methyltriethoxysilane, tetraethoxysilane, ethyltriethoxysilane, diethyldiethoxysilane, tetramethoxysilane, dimethyldimethoxysilane, and combinations thereof.
15. The coating composition of claim 12 wherein the composition additionally comprises a UV light absorbing agent.
16. A coating composition comprising the polyurethane of claim 6 .
17. A polymeric substrate having at least one surface coated with a cured composition of claim 11 .
18. The polymeric substrate of claim 17 wherein the substrate comprises polycarbonate.
19. A polymeric substrate as in claim 17 wherein a primer layer is disposed between the polymeric substrate and the coating.
20. A polymeric substrate according to claim 17 wherein the coating is directly disposed on the surface of the polymeric substrate.
21. A polymeric substrate having at least one surface coated with a cured composition of claim 16 .