BIAXIALLY ORIENTED POLYESTER FILM

摘要

PURPOSE:To obtain the title film which has high scratch resistance unattainable by any conventional polyester film and can give a magnetic tape improved in insusceptibility to tape edge damage during running. CONSTITUTION:The tape consists mainly of ethylene naphthalate units, contains 0.13-3wt.% particles comprising an oxide of an element of the 5th or 6th period of the periodic table and having a mean primary particle diameter of 0.001-0.3mum and an average degree of agglomeration of 2-100 and has a Young's modulus of elasticity of 600kg/mm<2> or above in the direction of film width.