Patent ID: 7371805

Claim:
A hydrogenated copolymer obtained by hydrogenating an unhydrogenated copolymer comprising conjugated diene monomer units and vinyl aromatic monomer units, said hydrogenated copolymer comprising: at least two polymer blocks (A) of vinyl aromatic monomer units, and at least one hydrogenated copolymer block (B) which is obtained by hydrogenating an unhydrogenated random copolymer block comprised of conjugated diene monomer units and vinyl aromatic monomer units, said unhydrogenated random copolymer block having a vinyl bond content of 60% or less as measured with respect to the conjugated diene monomer units in said unhydrogenated random copolymer block, said hydrogenated copolymer having the following characteristics (1) to (6): (1) said hydrogenated copolymer has a content of said vinyl aromatic monomer units of from more than 50% by weight to less than 95% by weight, based on the weight of said hydrogenated copolymer, (2) said hydrogenated copolymer has a content of said at least two polymer blocks (A) of 5 to 60% by weight, based on the weight of said hydrogenated copolymer, (3) said hydrogenated copolymer has a weight average molecular weight of from 30,000 to 1,000,000, (4) said hydrogenated copolymer has a hydrogenation ratio of 75% or more, as measured with respect to the double bonds in said conjugated diene monomer units, (5) at least one peak of loss tangent (tan δ) is observed at −10 to 80° C. in a dynamic viscoelastic spectrum obtained with respect to said hydrogenated copolymer, and (6) substantially no crystallization peak ascribed to said at least one hydrogenated copolymer block (B) is observed at −20 to 80° C. in a differential scanning calorimetry (DSC) chart obtained with respect to said hydrogenated copolymer.