| 摘要 |
PURPOSE:To obtain the titled film, consisting of a polyethylene terephthalate based polyester containing neopentyl glycol as a copolymerization component, capable of exhibiting stable heat shrinkability in a specific direction and providing a beautiful and strong packaged state as a packaging material. CONSTITUTION:A film, obtained by using a copolyester containing terephthalic acid and ethylene glycol as principal components and neopentyl glycol as a copolymerization component and having >=30% heat shrinkage factor in at least either one of longitudinal and width directions thereof in hot air at 100 deg.C. The ratio of the neopentyl glycol is preferably 5-20mol%. Specifically, the above-mentioned film is preferably obtained by drawing an undrawn film prepared by forming the film from the afore-mentioned copolymer at 3-6 times in one direction, drawing the resultant drawn film at 1.1-1.8 times in a direction perpendicular to the afore-mentioned direction and cooling the drawn film in an extended state. |
