| 摘要 |
PROBLEM TO BE SOLVED: To provide a block copolymer having both of high low-temperature shrinkage and high shrinkage stress and excellent in the balance of physical properties as a film, and to provide a heat shrinkable film therefrom. SOLUTION: The block copolymer consists of a vinyl aromatic hydrocarbon and a conjugated diene; has a weight average mol.wt. of 50,000-300,000; has a specific proportion of a polymer block A having a mass ratio of 90/10-100/0 respecting the vinyl aromatic hydrocarbon and the conjugated diene, a polymer block B having a mass ratio of 60/40-90/10, and a polymer block C having a mass ratio of 0/100-60/40, having at least one as for each; and has at least one random copolymer block having a mass ratio of 60/40-90/10. COPYRIGHT: (C)2004,JPO&NCIPI
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