TUBULAR FORMING MATERIAL AND ITS HEAT-SHRINKABLE FILM

摘要

To provide a tubular forming material excellent in bubble formation stability in the case of producing a heat-shrinkable film. To provide a tubular forming material made of a composition comprising block copolymers each made of a vinyl aromatic hydrocarbon and a conjugated diene, which has uniaxial elongation viscosity at 88°C at a strain rate of 0.5 sec -1 satisfying the following formula between 1.0 sec and 2.8 sec after initiation of elongation, 0.25 < LOG · 2.8 - LOG · 1.0 / 2.8 - 1.0 < 0.4
wherein · 1.0 and · 2.8 represent uniaxial elongation viscosities at elongation times of 1.0 sec and 2.8 sec, respectively, when measured by a Meissner model elongation viscometer.