| 摘要 |
<p>A polyester film comprises a non-liquid crystal polyester (A) and a copolyester (B) containing mesogen groups in the main chain to form a phase separated structure in the non-liquid crystal polyester (A), and the dispersed domains of the copolyester (B) having respective dimensions such as to satisfy the following formulae (1) and (2): <MATH> <MATH> where I, J and K are shape indicators expressing the average shape of the plurality of domains existing in the film: I is the average length of the dispersed domains of the copolyester (B) in the machine direction of the film; J, that in the transverse direction; and K, that in the normal direction: and S is a function for selecting the shorter value of the lengths I and J; if I > J, SÄI, JÜ means J, and if I < J, SÄI, JÜ means I.</p> |
