| 摘要 |
PROBLEM TO BE SOLVED: To provide a biodegradable polylactic acid-based shrink sheet product for package which has a satisfactory shrinkage rate and is excellent in impact resistance (breakage resistance) and, especially, in transparency and is free of irregularity of thickness upon stretching. SOLUTION: The shrink film or sheet is obtained by shaping a plastic material, which is made of a mixture of a polylactic acid material having a ratio between D-lactic acid and L-lactic acid within a given range sand an aliphatic polyester wherein the aliphatic polyester has a heat quantityΔHm of melting of crystals of 55 J/g or below and an apparent melt viscosity of the polymer is in a constant relation when an apparent shearing rate is 102 (1/sec). The film or sheet has a skin layer made mainly of the polylactic acid material and has a thermal shrinkage rate in a uniaxial direction of, at least, 10% or over in hot water of 80 deg.C/10 seconds. |
