Patent ID: 6423761
Filing Date: 2002-07-23
Classification: C07F,C08F,G02B

Abstract:
A cross-linked polymer obtained by polymerizing a mixture consisting essentially of:i) a zwitterionic monomer of the formula (V): wherein BB is a straight or branched C1-C6 alkylene chain optionally interrupted by one or more oxygen atoms:nn is from 1 to 12; R11 is H or a C1-C4 alkyl group; and YY is a zwitterionic group which is selected from the group consisting of: wherein mm is 1 to 4, nn is 1 to 12 and BB is a straight or branched C1-C6 alkylene chain optionally interrupted by one or more oxygen atoms;ii) a non-ionic diluent monomer; and iii) a cross-linking monomer which forms cross-links during the polymerization reaction.