| 摘要 |
PROBLEM TO BE SOLVED: To provide a polylactic-acid-series shrink-sheet-like matter which has a sufficient shrinkage factor and biodegradability and, moreover, to provide the biodegradable polylactic-acid series shrink-sheet-like matter which causes no mutual fusing of labels in sterilization by heating when the matter is used for the labels of a drink bottle or the like. SOLUTION: This sheet-like matter is molded of a biodegradable polymer constituted mainly of a polylactic-acid-series polymer. In this case, the crystal melting heat quantity (ΔHm) of the polylactic-acid-series polymer is 5-45 J/g, and a difference between a crystallization heat quantity (ΔHc) generated by the crystallization of the polylactic-acid-series polymer, a constituent of the biodegradable polymer forming this sheet-like matter, on the occasion when the temperature of the sheet-like matter is raised, and ΔHm, i.e., ΔHm-ΔHc, is 5-32 J/g. |
