Patent ID: 6852816

Claim:
A polymerisation process in which ethylenically unsaturated monomers including a zwitterionic monomer of the general formula I Y B X I in which Y as 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 — a 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 —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, and alkylene (oligooxalkylehe) groups, optionally containing one or more fluorine substituents; X is ammonium phosphonium, or sulphonium phosphate or phosphonate ester zwitterionic group; are polymerised by a living radical polymerisation process in the presence of an initiator, and a catalyst.