| abstract |
A block copolymer comprising: a polymer block (A) containing more than 70 mol% of a structural unit derived from an aromatic vinyl compound; and a polymer block (B) containing 30 mol% or more of a structural unit derived from a conjugated diene compound, said block copolymer further satisfying the following conditions. Condition (1): the contained amount of the polymer block (A) in the block copolymer is 1-70 mass%. Condition (2): the maximum width of a sequential temperature range in which tanδ is 1.0 or more is less than 16°C, as measured under the conditions of a distortion amount of 0.1%, a frequency of 1 Hz, a measurement temperature of -70 to 100°C and a temperature rise rate of 3°C/min, in accordance with JIS K 7244-10 (2005). Condition (3): the temperature at a peak position of tanδ under condition (2) is 0°C to +50°C. Condition (4): a mobility parameter M indicating the mobility of the polymer block (B) is 0.01 to 0.25 seconds. |