BIAXIALLY ORIENTED POLYESTER FILM FOR MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain a high quality film excellent in flatness and lubricity having satisfactory running performance and wear resistance at the time of repetitive use and excellent also in running performance after storage at high temp. and humidity. CONSTITUTION:This polyester film contains 0.01-0.5wt.% spherical composite particles having 0.6-2mum average particle diameter and consisting of an org. compd. having plural amino groups in one molecule and silica gel and 0.05-2wt.% practically amorphous fine particles of a multiple oxide having 0.01-0.2mum average particle diameter. The multiple oxide is a compd. consisting of two or more kinds of metallic elements including Al and oxygen. In the compd., the pref. molar ratio of Al to (Al+M) (M is metallic elements other than Al) is 0.3-0.9.