LAMINATED POLYESTER FILM FOR MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To prevent generation of scratch or worn powder when running by containing a specific amount of an inorganic particle having a specific hardness and particle diameter in a front and rear layer of a film made of a laminated polyester having >3 layers and by allowing coefficient of friction and surface roughness of the front and rear layer of the film to satisfy a specific formula. CONSTITUTION:The inorganic particle having >=8 Mohs scale and 0.005-0.5mum av. particle diameter is contained in the front and rear layer of the film made of the laminated polyester having >=3 layers. The content is 0.25-5wt.% per the weight of the front and rear layer of the polyester and <=0.20wt.% per the total weight of the polyester including the inside layer. And the coefficient of friction of the bare surface of the front and rear layer is regulated to satisfy the formula. Aluminum oxide is preferable as the inorganic particle having >=8 Mohs scale.