PROCESS FOR THE PREPARATION OF MALEIMIDE COPOLYMERS AND THERMOPLASTIC RESIN COMPOSITION USING THE SAME

摘要

The present invention provides a process for the preparation of maleimide copolymers by emulsion polymerization of an aromatic vinyl monomer, a vinyl cyanide monomer and a maleimide monomer in specific proportions, a specific proportion of the aromatic vinyl monomer and not more than a specific proportion of the vinyl cyanide monomer is charged into the polymerization system before initiation of the polymerization. A mixture composed of the total amount of the maleimide monomer and the remainder of the other monomers is added to the polymerization system after initiation of the polymerization. According to the polymerization process, maleimide copolymers having excellent thermal resistance and resistance to thermal decomposition can be prepared in high yield. The present invention also provides a resin composition having excellent thermal resistance, resistance to thermal decomposition, and impact resistance which is formed by blending, in a specific proportion, a maleimide copolymer prepared by the aforesaid process with a rubber-reinforced resin obtained by grafting a vinyl cyanide monomer or the like onto a specific elastomer; and optionally blending the resulting thermoplastic resin composition with a thermoplastic resin that is hard at room temperature. Although other uses will be evident, the copolymers of the invention are particularly useful in producing molded parts for automobiles.