Patent ID: 7300990

Claim:
A block copolymer of the A-B or A-B-A type in which A and B are different in which at least one of the A and B is formed from ethylenically unsaturated monomer including a zwitterionic monomer of the general formula VI YBX 1 VI in which Y is an ethylenically unsaturated group selected from the group consisting of H 2 C═CR—CO-A-, H 2 C═CR—C 6 H 4 -A 1 -, H 2 C═CR—CH 2 A 2 , R 2 O—CO—CR═CR—CO—O, RCH═CH—CO—O—, RCH═C(COOR 2 )CH 2 —CO—O, A is —O— or NR 1 ; A 1 is selected from the group consisting of a bond, (CH 2 ) n A 2 and (CH 2 ) n SO 3 — in which n is 1 to 12; A 2 is selected from the group consisting of a bond —O—, O—CO—, CO—O, CO—NR 1 —, —NR 1 —CO, O—CO—NR 1 — and NR 1 —CO—O—; R is hydrogen or C 1-4 alkyl; R 1 is hydrogen, C 1-4 alkyl or BX; R 2 is hydrogen or C 1-4 alkyl; B is selected from the group consisting of a bond and straight and branched alkanediyl, alkylene oxaalkylene, or alkylene (oligooxalkylene) groups, optionally containing one or more fluorine substituents; and X 1 is a zwitterionic group.