Dimethylacrylamide-copolymer hydrogels with high oxygen permeability
US4954587A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 23, 1989 |
| Grant date | Sep 4, 1990 |
| Priority date | — |
| Expiry date | May 23, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B1/043
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
This invention describes polymers which are obtained by copolymerization of 15-85 wt % N,N-dimethylacrylamide with about 15-85% of a fluorinated monomer such as perfluoroalkyl-alkylene acrylate or methacrylate with from 3 to 25 fluorine atoms and optionally, 0-50 wt % other acrylates or methacrylates and 0-20 wt %, but not more than 5 mol % of a polyvinyl functional crosslinking agent. These polymers are machinable in the dry state and form clear hydrogels with about 25-75 wt % water content and which possess oxygen-permeabilities 3-7 times higher than conventional hydrogels of similar water content. In the absence of crosslinking, the novel polymers are plasticized by water, forming clear hydroplastics with 30-70 wt % water content. The crosslinked polymers are especially useful for fabricating contact lenses for extended wear by either cutting and polishing a xerogel button, or by spin casting or direct molding in bulk or in solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.