Patent ID: 8637604
Filing Date: 2014-01-28
Classification: C08F,C08L

Abstract:
1. A block copolymer comprising polymer block A comprising conjugated diene monomer units and aromatic vinyl monomer units, and polymer block B comprising conjugated diene monomer units and aromatic vinyl monomer units, wherein said block copolymer is a straight chain block copolymer represented by the following general formula (1) or (2): wherein A represents polymer block A, and B represents polymer block B, wherein A represents polymer block A, B represents polymer block B, X the ratio of the conjugated diene monomer units to aromatic vinyl monomer units in the polymer block A is in the range of 95/5 to 30/70 by weight, and the ratio of the conjugated diene monomer units to the aromatic vinyl monomer units in the polymer block B is in the range of 5/95 to 30/70 by weight, and said block copolymer satisfies the following requirements: (1) the polymer block A has a glass transition temperature in the range of −88° C. to −45° C. as measured by differential scanning calorimetry, (2) the polymer block B has a glass transition temperature in the range of 30° C. to 90° C. as measured by differential scanning calorimetry, (3) the content of aromatic vinyl monomer units in the whole block copolymer is in the range of 3% to 52% by weight based on the weight of the block copolymer, (4) the aromatic vinyl block ratio in the whole block copolymer is smaller than 69% by weight, (5) the viscosity of a solution of the block copolymer in styrene with a concentration of 5% by weight as measured at 25° C. is in the range of 30 to 80 mPa·s, and (6) the ratio of the polymer block A to the polymer block B is in the range of 0.43 to 4.0 by weight.