| 摘要 |
PROBLEM TO BE SOLVED: To provide a polystyrene heat shrinkable film capable of being used for a shrink package, shrink-bundled package, shrink label, etc., excellent in low temperature shrinkage, reducing natural shrinkage, being firm, and improving elongation characteristics both in the main shrinking direction of the film and in its right-angled direction. SOLUTION: This heat shrinkable polystyrene film consisting of a mixture of (a) 50-80 wt.% styrene-butadiene block copolymer containing >=85 wt.% styrene, and having >=1.00×10<9> Pa storage elastic modulus (E') at 40 deg.C and one peak temperature of loss elastic modulus (E") at >=30 deg.C and <=80 deg.C, (b) 50-20 wt.% styrene-butadiene block copolymer containing 20-50 wt.% butadiene, and having >=1.00×10<9> Pa storage elastic modulus (E') at 40 deg.C and at least one peak temperature of loss elastic modulus (E") at <=-30 deg.C, and (c) 0-10 wt.% polystyrene resin is characterized by stretching it at least one direction and having >=5% heat shrinkage in a warm water at 70 deg.C in its main shrinking direction for 10 sec. |
