| 摘要 |
PURPOSE:To provide the title molded article obtained by stretching a partial hydrolysate of a vinyl ester polymer, having a high shrinkability in the presence of moisture such as humidity, a high transparency, and a high strength even after the shrinkage due to moisture absorption and widely adaptable to a packing material. CONSTITUTION:A vinyl ester polymer to be used is obtained, for example, by polymerizing or copolymerizing a vinyl aliphatic org. acid ester monomer such as vinyl formate or vinyl acetate and/or a vinyl aromatic org. acid ester such as vinyl benzoate. The polymer or copolymer is then partially hydrolyzed. The hydrolyzing ratio in this case is pref. 0.1-75mol%. The hydrolysis of the vinyl ester polymer can be easily performed at 30-50 deg.C in the presence of a catalyst such as sodium hydroxide. The partial hydrolysate thus obtained is stretched by an inflation method to form a film. |
