| 摘要 |
PROBLEM TO BE SOLVED: To provide a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene having sufficient shock resistance and flexibility and forming a sheet or its fabricated product hardly whitening by bending and exhibiting good appearance. SOLUTION: In the block copolymer comprising a vinyl aromatic hydrocarbon and a conjugated diene, a local maximal value is observed for a loss elastic modulus (E"<SB>T1</SB>) in a temperature range from -20 to +20°C by dynamic viscoelasticity measurement, and a mass ratio of the conjugated diene to the total mass of the block copolymer is 15-35 mass%. COPYRIGHT: (C)2010,JPO&INPIT
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