Patent ID: RE41208

Claim:
A sea water-insoluble polymer comprising quaternary ammonium groups and/or quaternary phosphonium groups bound to a backbone of the polymer comprising a group of formula: wherein Y is O or NH, Z is N or P, R 1 is a hydrogen atom or a C 1 -C 4 alkyl group, R 2 is a C 2 or a C 3 -C 12 divalent hydrocarbon group, R 3 and R 4 independently represent a C 1 -C 6 alkyl group, R 5 is a C 1 -C 5 alkyl group, said quaternary ammonium groups and/or quaternary phosphonium groups being neutralised by counter-ions that consist of the anionic residue of an acid having an aliphatic, aromatic, or alkaryl hydrocarbon group comprising 6 or more carbon atoms; said counter-ions being capable of hydrolyzing, dissociating or exchanging with sea water species to leave a polymer framework that is soluble in sea water.