Method of preventing colouring of homopolymers of vinyl chloride, vinylidene chloride, vinylidene cyanide, or a copolymer comprising the same

摘要

Polymers containing vinyl chloride, vinylidene chloride or vinylidene cyanide are prevented from yellowing by the incorporation of phosphorus pentoxide. Polymers exemplified are vinylidene cyanide-vinyl acetate copolymers, polyvinyl chloride, vinyl chloride-acrylonitrile copolymers, vinylidene chloride-vinyl chloride-acrylonitrile copolymers and a mixture of poly-vinyl formal and a vinyl acetate-vinylidene cyanide copolymer. The phosphorus pentoxide may be added to a solution or dispersion of the polymer which may then be spun into fibres or it may be incorporated in shaped articles.