Abstract: An acrylonitrile polymer composition comprising an admixture of(I) 30 to 80 weight % of an acrylonitrile polymer containing at least 40 weight % acrylonitrile;(II) 10 to 80 weight % of a chlorine containing polymer having a chlorine content of at least 20 weight %; and(III) 0.5 to 10 weight % of an A-B block copolymer in which B is acrylonitrile and A is a monomer copolymerizable with monomer B.

Abstract: An impact resistant plastic graft copolymer composition is prepared by1. agglomerating 100 parts by weight in terms of the solids content of a synthetic rubber latex (A) containing small-sized rubber particles by adding 0.1 - 5 parts by weight, in terms of the solids content of a carboxylic acid containing copolymer latex (B) having a pH of at least 4, said copolymer latex being prepared by polymerizing a mixture of monomers comprising 5 - 20% by weight of at least one monomer selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid and crotonic acid and 95-80% by weight of alkyl acrylate having 1 to 12 carbon atoms in the alkyl group, in the presence of at least one anionic emulsifier, and adjusting the pH of the mixed latexes (A) and (B) to not less than 6;2. stabilizing the agglomerated latex with at least one nonionic emulsifier, and3.