| 摘要 |
PURPOSE:To provide a film which has no surface failure due to contaminants and excellent transparency and in which there is a specified relationship between the quantity of oligomer in surface layer and haze, by incorporating a higher fatty acid in polyethylene terephthalate. CONSTITUTION:A film is an oriented film composed of polyethylene terephthalate contg. 0.11-0.5wt% higher fatty acid ester incorporated therein and has relationship of Mt<=0.8; Mt/Ht<0.1 wherein Mt(gamma/cm<2>) is the quality of oligomer in the surfacve layer of a film heat-treated at a temp. T( deg.C) of 160-200 deg.C for one hr, and Ht(%) is haze (interms of 15mu thick film) of a film heat-treated at the temp. T( deg.C) for one hr. The higher fatty acid ester is obtd. by partially or wholly esterfying a 10-33C, pref. 20-32C straight-chain or branched monocarboxylic acid with a 2-33C mono- or bivalent straight-chain or branched alcohol.
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