BLOCK COPOLYMER AND METHOD FOR PRODUCING SAME, COMPOSITION FOR RESIN MODIFICATION, AND MODIFIED RESIN COMPOSITION AND METHOD FOR PRODUCING SAME

摘要

Disclosed is a block copolymer including a polymer block A containing a conjugated diene monomer unit, and a polymer block B containing a conjugated diene monomer unit and an aromatic vinyl monomer unit. This block copolymer is characterized in that (1) the glass transition temperature of the polymer block A is from -88°C to -45°C; (2) the glass transition temperature of the polymer block B is from 30°C to 90°C; (3) the aromatic vinyl monomer unit content in the total block copolymer is 3-52% by weight; (4) the aromatic vinyl block ratio in the total block copolymer is less than 69% by weight; and (5) the 5 wt% styrene solution viscosity is 30-80 mPa·s. This block copolymer can be used as a resin modifier.