TRANSPARENT IMPACT RESISTANT IMPROVED POLYSTYRENE BASED ON STYRENE/BUTADIENE BLOCK COPOLYMER, ITS POLYMER MIXTURE AND PROCESSES FOR THEIR PRODUCTION

摘要

PROBLEM TO BE SOLVED: To provide a transparent impact resistant improved polystyrene with favorable balance in the ratios of toughness and stiffness without conventional drawbacks. SOLUTION: The block copolymer is produced from an aromatic vinyl monomer and contains at least two hard blocks S1and S2. The block copolymer contains at least one random soft block B/S produced from the aromatic vinyl monomer and a diene between the hard blocks S1and S2, and contains less than 20% of 1,2-vinyl in the soft block B/S and has the hard block ratios at 51-74 mass% in the total block copolymers without containing a single polymer block B composed of the diene. COPYRIGHT: (C)2004,JPO&NCIPI