Lightly cross-linked hydrogel formed from N-vinyl lactam and hydrophobic acrylic ester comonomer
US4036814A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1975 |
| Grant date | Jul 19, 1977 |
| Priority date | — |
| Expiry date | Jun 25, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B1/043
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A copolymeric hydrogel for contact lenses with physiological saline uptake 65-85% is formed from an N-vinyl lactam e.g. N-vinyl-2-pyrrolidone and up to 15% of a hydrophobic comonomer of formula ##STR1## where R.sup.1 is H or C.sub.1 -C.sub.4 alkyl (preferably methyl) X is --O-- or --NH-- and R.sup.2 is aryl, C.sub.1 -C.sub.6 alkyl substituted by aryl or aryloxy, or C.sub.1 -C.sub.6 alkoxy substituted by aryl or aryloxy. Preferably the aryl or aryloxy group contain one or two six-membered carbocyclic aromatic rings; they may be C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, or halogen, substituted. Crosslinking agents used preferably have their two functional groups differing in reactivity e.g. allyl, or 3-allyloxy-2-hydroxypropyl, methacrylates.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.