To obtain a thermoplastic resin composition excellent in heat resistance by compounding a resin mixture comprising a polyketone resin and an ABS resin with a block copolymer containing aromatic vinyl polymer blocks and aromatic vinyl/vinyl cyanide polymer blocks.
An aromatic vinyl monomer, such as styrene, is subjected to radical polymerization in the presence of, e.g. thio-S-acetic acid to form a polymer having a mercapto group on one end and a number-average molecular weight of 1,000 to 1000,000. In the presence of this polymer, a monomer mixture comprising an aromatic vinyl and vinyl cyanide, e.g. styrene and acrylonitrile at a molar ratio of about (70:30) to (95:5) is subjected to radical polymerization to form polymer blocks with a number-average molecular weight of 1,000 to 100,000, thus giving a block copolymer. 100 pts.wt. resin mixture comprising 10-90 pts.wt. polyketone resin having structural units represented by the formula (wherein A is an olefin) and 90-10 pts.wt. ABS resin is formulated with 0.1-20 pts.wt. of the block copolymer, and the compound is compounded and extruded through, e.g. a twin-screw extruder to give a thermoplastic resin composition.
UNO MASANARI
MIURA TSUTOMU
