Process for producing thermoplastic resin highly resistant to impact and

Abstract

A process for producing a thermoplastic polymer highly resistant to impact and weather by graft-copolymerizing, in the presence of a water-soluble polymer and a radical polymerization initiator in an aqueous medium, [B] 90 to 60 parts by weight of a monomer mixture comprising 30 to 100% by weight of an aromatic vinyl compound (for example, styrene) and 0 to 70% by weight of acrylonitrile plus methyl methacrylate in which the proportion of acrylonitrile is 20 to 100% by weight and that of methyl methacrylate is 80 to 0% by weight, on [A] 10 to 40 parts by weight (in terms of solids content) of a rubbery copolymer latex obtained by copolymerizing in an aqueous emulsion a mixture comprising [I] 60 to 99.9% by weight of at least one alkyl acrylate (for example, butyl acrylate) having 1 to 13 carbon atoms in the alkyl group, [II] 0 to 20% by weight of at least one vinyl compound copolymerizable with [I] (for example, styrene) and [III] 0.1 to 20% by weight of at least one organic polyallyl compound copolymerizable with [I] (for example, triallyl isocyanurate), which is characterized by previously subjecting the reaction system to a mechanical mixing treatment (mixing by means of, for example, an ordinary agitator, homogenizer, or colloid mill) and then conducting said graft-copolymerization.