| 摘要 |
<p>Disclosed is a block copolymer composition containing an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer having a high-level balance between high elastic modulus and small permanent elongation. The block copolymer composition contains a block copolymer A represented by formula (A) and a block copolymer B represented by formula (B). The weight ratio between the block copolymer A and the block copolymer B (A/B) is from 36/64 to 85/15, and the ratio of the aromatic vinyl monomer units relative to all polymer components in the block copolymer composition is 27-70% by weight. (In the formulae, Ar1a, Ar1b and Ar2b each represents an aromatic vinyl polymer block having an Mw of 6,000-18,000; Ar2a represents an aromatic vinyl polymer block having an Mw of 40,000-400,000; Da and Db each represents a conjugated diene polymer block having a vinyl bond content of 1-20% by mole; and Db has an Mw of 60,000-400,000.)</p> |
