Hydrogel from ultraviolet-initiated copolymerization
US4620954A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1985 |
| Grant date | Nov 4, 1986 |
| Priority date | — |
| Expiry date | Jun 7, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B1/043
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
In the particular embodiment described in the specification, a contact lens hydrogel is prepared by copolymerizing 75 parts of N-vinyl pyrrolidone and 23 parts of phenyl ethyl methacrylate together with allyl methacrylate as a crosslinker, t-butyl peroctoate as a thermal initiator and 2,2-dimethoxy-2-phenylacetophenone or benzoin methyl ether as a photoinitiator. The mixture is maintained at a temperature of 5.degree. C. and protected from light prior to photopolymerization which is carried out under ultraviolet radiation. The copolymer is then post-cured thermally. Cloudy or hazy hydrogels are avoided by preventing prepolymerization of the mixture.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.