Moldings and preparation and uses thereof
View Patent ↗An ophthalmic lens made from a crosslinkable polymer containing H-active groups bonded to the oligomer or polymer backbone, some or all of whose hydrogen atoms have been substituted by radicals of a N-hydroxyalkyl (meth)acrylamide. The lens transmits at least 70% of visible light.
1. An ophthalmic lens comprising the cross-linked product of a first polymer, wherein said first polymer is a radiation-curable (meth)acrylamidoalkyl derivative of an oligomer or polymer containing a plurality of H-active groups, wherein said lens transmits at least 70% of visible light.
2. A lens as claimed in claim 1 , wherein said H-active groups are selected from the group consisting of —NH 2 groups and —OH groups.
3. A lens as claimed in claim 1 , wherein said (meth)acrylamidoalkyl derivative is obtained by substituting at least one hydrogen atom in H-active groups of the oligomer or polymer with radicals of a N-hydroxyalkyl (meth)acrylamide of the structure
wherein R 1 is methyl or —H; R 2 is —[(CH 2 ) x —O—] y —H, where x is 1, 2, or 3 and y is 1–5.
4. A lens as claimed in claim 3 , wherein R 1 is —H, x is 1 or 2, and y is 1 or 2.
5. A lens as claimed in claim 4 , wherein the N-hydroxyalkyl (meth)acrylamide is selected from the group consisting of N-2-hydroxylethyl acrylamide, N-2-hydroxyethyl methacrylamide, N-methylol acrylamide, and N-methylol methacrylamide.
6. A lens as claimed in claim 1 , wherein said lens has a water content between 40% and 80%.
7. A lens as claimed in claim 2 , wherein said first polymer is selected from the group consisting of polysaccharides, polysaccharide derivatives, poly(vinyl alcohol), poly(ethylene glycol), poly(propylene oxide), PEG-block-PPO, poly(acrylamide) poly(acrylamide), and copolymers thereof.
8. A lens as claimed in claim 7 , wherein said first polymer is selected from the group consisting of polysaccharides and polysaccharide derivatives.
9. A lens as claimed in claim 8 , wherein said first polymer is selected from the group consisting of dextran, hydroxypropylcellulose, hydroxyethylcellulose, and polysaccharides comprising glucose monosaccharide units.
10. A lens as claimed in claim 8 , wherein said first polymer is selected from the group consisting of water-soluble polysaccharides and water-soluble polysaccharide derivatives.
11. A lens as claimed in claim 1 , wherein said first polymer is dextran and said N-hydroxyalkyl (meth)acrylamide is N-methylol acrylamide.
12. A lens as claimed in claim 1 , wherein said first polymer is soluble in water before it is crosslinked, and swellable in water after it is crosslinked.
13. A lens as claimed in claim 1 , further comprising the crosslinked product of a second polymer, wherein said second polymer is a water-soluble crosslinkable polymer.
14. A lens as claimed in claim 13 , wherein said second polymer is nelfilcon A.
15. A lens as claimed in claim 14 , wherein said nelfilcon A is present in the lens in an amount greater than said first polymer.
16. A method for making a contact lens material comprising the steps of:
a) preparing a substantially aqueous solution of a polymer containing a plurality of H-active groups;
b) adding an N-hydroxyalkyl (meth)acrylamide and a water-soluble polymerization inhibitor to the solution; and
c) adding a water-soluble condensation catalyst to the solution to cause a condensation reaction between the hydroxyl groups of the N-hydroxyalkyl (meth)acrylamide and the H-active groups of the polymer.
17. A method for making a molding comprising the following steps:
a) preparing a substantially aqueous solution of a first polymer, wherein said first polymer is a radiation-curable (meth)acrylamidoalkyl derivative of an oligomer or polymer containing a plurality of H-active groups;
b) introducing the solution obtained into a mold;
c) exposing the polymer to radiation to crosslink the polymer; and
d) opening the mold such that the molding can be removed from the mold.
18. A method as claimed in claim 17 , wherein said H-active groups are selected from the group consisting of —NH 2 groups and —OH groups.
19. A method as claimed in claim 17 , wherein said (meth)acrylamidoalkyl derivative is obtained by substituting at least one hydrogen atom in H-active groups of the oligomer or polymer with radicals of a N-hydroxyalkyl (meth)acrylamide of the structure
wherein R 1 is methyl or —H; R 2 is —[(CH 2 ) x —O—]— y H, where x is 1, 2, or 3 and y is 1–5.
20. A method as claimed in claim 19 , wherein R 1 is —H, x is 1, and y is 1.
21. A method as claimed in claim 20 , wherein the N-hydroxyalkyl (meth)acrylamide is selected from the group consisting of N-2-hydroxylethyl acrylamide, N-2-hydroxyethyl methacrylamide, N-methylol acrylamide, and N-methylol methacrylamide.
22. A method as claimed in claim 17 , wherein said lens has a water content between 40% and 80%.
23. A method as claimed in claim 18 , wherein said first polymer is selected from the group consisting of polysaccharides, polysaccharide derivatives, poly(vinyl alcohol), poly(ethylene glycol), poly(propylene oxide), PEG-block-PPO, poly(acrylamide) poly(acrylamide), and copolymers thereof.
24. A method as claimed in claim 23 , wherein said first polymer is selected from the group consisting of polysaccharides and polysaccharide derivatives.
25. A method as claimed in claim 24 , wherein said first polymer is selected from the group consisting of dextran, hydroxypropylcellulose, hydroxyethylcellulose, and polysaccharides comprising glucose monosaccharide units.
26. A method as claimed in claim 24 , wherein said first polymer is selected from the group consisting of water-soluble polysaccharides and water-soluble polysaccharide derivatives.
27. A method as claimed in claim 17 , wherein said first polymer is dextran and said N-hydroxyalkyl (meth)acrylamide is N-methylol acrylamide.
28. A method as claimed in claim 17 , wherein said first polymer is soluble in water before it is crosslinked, and swellable in water after it is crosslinked.
29. A method as claimed in claim 17 , wherein said solution further comprises second polymer, wherein said second polymer is a water-soluble crosslinkable polymer.
30. A method as claimed in claim 29 , wherein said second polymer is nelfilcon A.
31. A method as claimed in claim 30 , wherein said nelfilcon A is present in the lens in an amount greater than said first polymer.