| abstract |
A hydrogenated block copolymer having a number-average molecular weight of 40,000 to 700,000 and a thermoplastic resin composition comprising the same are disclosed. Said copolymer is obtained by hydrogenating a block copolymer (I) or (II) to such an extent that at least 80 % of the olefinically unsaturated bonds of said block copolymer are hydrogenated. Said block copolymer (I) is one having at least one polymer block A 90 wt % of which is composed of a vinyl aromatic compound, at least one polybutadiene polymer block B wherein 1,2-vinyl bonds account for 30 to 70%, and at least one polybutadiene polymer block C wherein 1,2-vinyl bonds account for less than 30%, with the proportions of the blocks A, B and C being specific, while said block copolymer (II) is one wherein the block copolymer (I) is bound to at least one of the polymer block units of A, B and C through a coupling agent residue to elongate or branch the polymer chain. |