HEAT-RESISTANT COPOLYMER OF A-METHYLSTYRENE AND ACRYLONITRILE, PROCESS FOR PREPARING THE SAME ANF THERMOPLASTIC RESIN COMPOSITION CONTAINING THE SAME

摘要

A method for prepg. a novel heat resisting copolymer contg. alpha- methylstylene (MS) 74-82 wt.% and acrylonitrile (AN) 18-26 wt.% comprises (i) supplying MS and AN into a polymg. system, at the ratio of MS to AN less than 9, (ii) emulsifying the rxn. mixt. and polymerizing it at 67-90 deg.C and (iii) continuously or intermittently supplying AN or MS-AN mixt. to maintain at above 7 the wt. ratio of MS/AN in unreacted monomers. The copolymer contains - [MS-MS-MS - monomer-chain 0-15 wt.%, -[MS-MS-AN - chain above 50 wt.% and -[AN-MS-AN - chain below 50 wt.%.