Heat-resistant copolymer of alpha-methylstyrene and acrylonitrile, process for preparing the same, and thermoplastic resin composition containing the same

摘要

A heat-resistant copolymer obtained by copolymerizing (A) 72-82 parts by weight of alpha -methylstyrene and (B) 26-18 parts by weight of acrylonitrile, characterized in that the copolymer contains (a) 0-15% by weight of monomer chain -(A)-(A)-(A)-, (b) 50% by weight or more of monomer chain -(A)-(A)-(B)-, and (c) 50% by weight or less of monomer chain-(B)-(A)-(B)-, the total of (a), (b) and (c) being 100% by weight. This copolymer is excellent in heat stability and moldability when molded at high temperatures, and the blending of this copolymer with other thermoplastic resins gives thermoplastic resins with excellent heat resistance.