POLYESTER HEAT-SHRINKABLE FILM

摘要

PURPOSE: To provide a polyester heat-shrinkable film having heat shrinkability well-balanced longitudinally and laterally and having clean finish appearance not generating a defect such as wrinkles, strain or shrinkage irregularity at the time of heat shrinkage by a usual sequential biaxial stretching method. CONSTITUTION: A polyester heat-shrinkable film is obtained by the sequential biaxial stretching of copolyester based on ethylene terephthalate and containing 5-25mol% of other dicarboxylic acid component and/or a diol component and characterized by that the relation of X>Y is formed between the heat shrinkage factors X%, Y% of a film uniaxially stretched within a temp. range from glass transition temp. +5 deg.C-+20 deg.C at 100 deg.C by 2 and 4 times. The heat shrinkage factors in the longitudinal and lateral directions of this film at 100 deg.C are set to 10-50% and the difference between them is set to 10% or less.