| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyester film which has good heat-invulnerable peelability to inks, adhesives, etc. and undergoes less dimensional change due to heat.SOLUTION: A polyester film is a stretched polyester film of a thickness of 3-50 μm and has a thermal shrinkage in the film longitudinal direction of 1-8%, and (i) the crystallinity of at least one side of the film, measured by the total reflection infrared absorption(ATR-IR) method, (ii) the surface orientation coefficient, measured by the total reflection infrared absorption(ATR-IR) method, and (iii) the polarity force component in the surface free energy are each within specified ranges. |
