Crosslinkable polymer
View Patent ↗The present invention provides a crosslinkable prepolymer which can be used to produce crosslinked polymeric materials (or contact lenses containing the same) having a high strength and excellent durability. The present invention relates to a polyvinyl alcohol-based prepolymer containing a unit having a pendant 1,2-diol containing group and a unit having a specific crosslinkable functional group, as well as a molding using the same.
1. A polyvinyl alcohol-based prepolymer comprising at least one unit of the formula (1) and at least one unit of the formula (2):
wherein
each of R 1a , R 2a and R 3a independently is hydrogen or an organic group,
X is a single bond or a bonding chain, and
each of R 4a , R 5a and R 6a independently is hydrogen or an organic group;
wherein
R b is an alkylene group having up to 12 carbon atoms,
R 1b is hydrogen or a C 1 -C 6 alkyl group,
R 2b is an olefinically unsaturated, electron-withdrawing, crosslinkable functional group, and
R 3b is hydrogen, a C 1 -C 6 alkyl group or a cycloalkyl group.
2. The polyvinyl alcohol-based prepolymer according to claim 1 , wherein R 2b in the formula (2) is an olefinically unsaturated, electron-withdrawing, crosslinkable functional group, having up to 25 carbon atoms.
3. The polyvinyl alcohol-based prepolymer according to claim 2 , which further comprises at least one unit of the formula (3):
wherein R 1c is a C 1 -C 6 alkyl group.
4. A crosslinked polymer obtainable by photocrosslinking the polyvinyl alcohol-based prepolymer according to claim 1 .
5. A molding comprising the crosslinked polymer according to claim 4 .
6. The polyvinyl alcohol-based prepolymer according to claim 1 , which further comprises at least one unit of the formula (3):
wherein R 1c is a C 1 -C 6 alkyl group.
7. The crosslinked polymer of claim 4 , wherein R 2b in the formula (2) is an olefinically unsaturated, electron-withdrawing, crosslinkable functional group, having up to 25 carbon atoms.
8. The crosslinked polymer of claim 7 , wherein the polyvinyl alcohol-based prepolymer further comprises at least one unit of the formula (3):
wherein R 1c is a C 1 -C 6 alkyl group.
9. The crosslinked polymer of claim 4 , wherein the polyvinyl alcohol-based prepolymer further comprises at least one unit of the formula (3):
wherein R 1c is a C 1 -C 6 alkyl group.
10. The molding of claim 5 , wherein the moldings are contact lenses.
11. The molding of claim 5 , wherein R 2b in the formula (2) is an olefinically unsaturated, electron-withdrawing, crosslinkable functional group, having up to 25 carbon atoms.
12. The molding of claim 11 , wherein the moldings are contact lenses.
13. The molding of claim 11 , wherein the polyvinyl alcohol-based prepolymer further comprises at least one unit of the formula (3):
wherein R 1c is a C 1 -C 6 alkyl group.
14. The molding of claim 13 , wherein the moldings are contact lenses.
15. The molding of claim 5 , wherein the polyvinyl alcohol-based prepolymer further comprises at least one unit of the formula (3):
wherein R 1c is a C 1 -C 6 alkyl group.
16. The molding of claim 15 , wherein the moldings are contact lenses.
17. A process for producing moldings, comprising the step of irradiating actinically a polymerizable composition comprising a polyvinyl alcohol-based prepolymer which comprises at least one unit of the formula (1) and at least one unit of the formula (2):
wherein
each of R 1a , R 2a and R 3a independently is hydrogen or an organic group,
X is a single bond or a bonding chain, and
each of R 4a , R 5a and R 6a independently is hydrogen or an organic group;
wherein
R b is an alkylene group having up to 12 carbon atoms,
R 1b is hydrogen or a C 1 -C 6 alkyl group,
R 2b is an olefinically unsaturated, electron-withdrawing, crosslinkable functional group, and
R 3b is hydrogen, a C 1 -C 6 alkyl group or a cycloalkyl group.
18. The process of claim 17 , wherein R 2b in the formula (2) is an olefinically unsaturated, electron-withdrawing, crosslinkable functional group, having up to 25 carbon atoms.
19. The process of claim 18 , wherein the polyvinyl alcohol-based prepolymer further comprises at least one unit of the formula (3):
wherein R 1c is a C 1 -C 6 alkyl group.
20. The process of claim 17 , wherein the moldings are contact lenses.