Improvements in or relating to acrylonitrile copolymers

摘要

Acrylonitrile copolymers having an affinity for basic dyes comprise as one monomer component a cyclic sulphone of general formula: where R and R1 are the same or different and are hydrogen atoms or hydrocarbon groups, preferred sulphones being those obtained by the reaction of sulphur dioxide with butadiene, isoprene, dimethylbutadiene and phenyl butadiene. The proportion of acrylonitrile is preferably 85% by weight and there may also be present as monomer component an acrylate or methacrylate. Examples describe the production of the copolymers by polymerization in aqueous emulsion in the presence of a catalyst system comprising potassium chlorate and sodium bisulphite at a pH of 2-5 by batch and continuous processes. The copolymers may be used for the production of films and fibres.