Polyvinyl chloride-base resin and multistage graft resin composition

Abstract

A composition with high impact resistance and little fish eyes content, comprising 97 to 60 parts by weight of a polyvinyl chloride-base resin and 3 to 40 parts by weight of a graft copolymer obtained by the three-stage graft-polymerization of 65 to 25 parts by weight of a monomer combination (B) comprising 12 to 57% by weight of methyl methacrylate, 1 to 24% by weight of at least one of alkyl acrylates having a C.sub.1-8 -alkyl group, 80 to 40% by weight of styrene and 0 to 3% by weight of a polyfunctional crosslinking agent having one or more alkyl groups in the molecule onto 35 to 75 parts by weight of a butadiene-base elastomer (A) containing 30% by weight or more of 1,3-butadiene units, said three-stage graft polymerization being carried out in the following way: at first at least one member selected from the group consisting of electrolytes and carboxyl-containing polymer latices is added to the reaction system; then in the first stage monomer mixture consisting of major amount of methyl methacrylate and minor amount of an alkyl acrylate or acrylates, which has a proportion of 50 to 90% by weight based on total weight of methyl methacrylate and alkyl acrylate or acrylates, and, if included in said monomer combination, a polyfunctional crosslinking agent are graft-polymerized; in the second stage, styrene is graft-polymerized; and in the third stage, the remaining 10 to 50% by weight of methyl methacrylate and an alkyl acrylate or acrylates are graft-polymerized.

Dependencies are inferred from the claim text.