BIAXIALLY ORIENTED POLYESTER FILM

摘要

PURPOSE:To prepare a biaxially oriented polyester film with a flat surface and excellent scratch resistance and slipperiness by incorporating a specified inactive fine particle and providing the degree of surface roughness of the film in a specified range. CONSTITUTION:A biaxially oriented polyester film is prepd. by incorporating an inactive fine particle with a Mohs hardness of 8 or larger and a mean particle diameter of 0.1mum or smaller (pref. Al2O3 with a particle diameter of about 0.01-0.1mum obtd. by pyrolysis) in such a manner that the Ra of the surface of this film is in the range of 0.003-0.009mum and the max. length Rt is 0.10mum or smaller. A biaxially oriented polyester film with an extremely flat film surface and good scratch resistance and slipperiness is obtd.