BIAXIALLY ORIENTED POLYESTER FILM

摘要

PURPOSE: To provide a biaxially oriented polyester film having straightforward tearability as well as excellent mechanical properties, heat resistance and dimensional stability. CONSTITUTION: This film is prepared by orienting an unoriented sheet mainly made of a mixture of 50-95wt.% thermoplastic polyester resin in which the acid component mainly consists of a terephthalic acid or naphthalenedicarboylic acid with 50-5wt.% thermoplastic polyester resin in the state in which it with the former resin forms a substantially phase-separated structure and satisfying the relationship: 0.1=IAR =1.0 (IAR is the transmitted and scattered light illuminance anisotropic ratio.