POLYESTER GROUP FILM MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To provide a polyester group film for magnetic recording medium, especially which is suitable for high density recording, superior in a secondary workability and shows a superior adhesion to a magnetic recording layer or a back coating layer without causing any problem such as blocking. CONSTITUTION:A composition consisting of a polyester group resin incorporating a metallic base of a sulfonic acid which is water-dispersible but water-insoluble and a lubricant, and having the number of coarse projections less than 10 pieces per 100cm<2>, when the film is formed from the composition, is applied at least on a surface of one side of a base film of the polyester group resin which the central line mean roughness Ra is <=0.02mum.