Patent ID: 6132462
Filing Date: 2000-10-17
Classification: A61L,C08F,G02B

Abstract:
A copolymer comprising, based on a total weight of 100%,(a) 60 to 80 weight % of a structure unit (I) ##STR10## wherein R.sup.1 represents a hydrogen atom or a lower alkyl group, R.sup.2 represents an unsubstituted lower alkylene group or a lower alkylene group substituted by a hydroxyl group, said lower alkylene group optionally containing an oxygen atom,(b) 10 to 30 weight % of a structure unit (II) ##STR11## wherein R.sup.3 represents a single bond or ##STR12## in which R.sup.5, R.sup.6, R.sup.7 and R.sup.8 each independently represent a hydrogen atom or a lower alkyl group, m, n, p and q are integers from 1 to 4, and R.sup.4 represents a hydrogen atom or a lower alkyl group, and(c) 5 to 20 weight % of a structure unit (III) ##STR13## wherein R.sup.9 represents a hydrogen atom or a lower alkyl group and R.sup.10 represents a lower alkyl group.