摘要 |
<p>A water insol., water swellable copolymer comprises 50-90, pref. 60-70% of (a) heterocyclic monomer selected from N-vinyl lactams, N-vinyl imidazolidene, N-vinyl succinimide, N-vinyl diglycol imide, N-vinyl glutarimide, N-vinyl-3-morpholinone and/or N-vinyl-5-methyl-3-morpholinone, 5-40, pref. 25-35 wt.% of (b) unstd. ester selected from 1-22C alkyl (meth)acrylates, vinyl esters of satd. monocarboxylic acids of =22C and 0.5-30, pref. 2.5-15 wt.% of (c) glycidyl esters selected from glycidyl (meth)acrylate and -crotonate. The polymers form transparent hydrogels for use as contact lenses.</p> |