BLOCK COPOLYMER AND POLYMER COMPOSITION COMPRISING THE SAME

摘要

A block copolymer comprising, in a main chain thereof, a crystalline polymer block A obtained by hydrogenation of at least 80% of unsaturated bonds of a butadiene-based polymer block having a 1, 2-bond content less than 20%, a polymer block B having a glass transition point of 20.degree.C or lower and a polymer block C composed mainly of a methacrylate ester unit and/or an acrylate ester unit and having a glass transition point exceeding 20.degree.C has good elastomeric properties, excellent weather resistance, solvent resistance and heat resistance and has good affinity with each of a polar polymer and non-polar polymer. A polymer composition comprising said block copolymer effectively exhibits the above-described characteristics of the block copolymer.