| 摘要 |
PROBLEM TO BE SOLVED: To provide a biaxially oriented polyester film for twisted packaging which is excellent in film making properties, thickness uniformity, twisting aptitude, bending fatigue resistance, and flavor properties. SOLUTION: The biaxially oriented polyester film is produced by a method in which in a polyester film comprising a layer A/a layer B/the layer A, the layer A is formed from a polyester mainly comprising ethylene terephthalate, the layer B is formed from a blended polymer of the ethylene terephthalate and a polyolefin, a cooled/solidified sheet (the layer A/the layer B/the layer A) is oriented in the transverse direction in the first step, oriented in the longitudinal direction in the second step, and heat-treated under tension, and the product (M×*T) of a draw ratio in the second step [M×(-)] and the temperature of the heat treatment under tension [T(°C)] is 200-400. COPYRIGHT: (C)2007,JPO&INPIT
|
