BIAXIALLY STRETCHED POLYESTER FILM

摘要

PURPOSE:To suppress the lowering of the flatness of a film due to heat shrinkage such as unevenness or a curl by stabilizing heat behavior after processing. CONSTITUTION:A biaxially stretched polyester film wherein at least two or more endothermic peaks are observed other than a melting peak at the time of thermal analysis and the temp. difference between the endothermic peak of the highest temp. and that of the lowest temp. excepting the melting peak is within the range of 20-130 deg.C and heat shrinkage factors at 150 deg.C in longitudinal and lateral directions are 0.8-0.5% has a water-soluble or water-dispersible resin layer with thickness of 0.001-0.3mum on at least the single surface thereof.