POLYESTER FILM FOR MAGNETIC RECORDING MEDIUM

摘要

PURPOSE: To remarkably improve scraping resistance and handleability in a process for producing a tape using a film having <=10μm, especially <=6μm thickness, to ensure superior output characteristics for a high density magnetic recording medium using the film as the substrate and to make it possible for the medium to well withstand long-time high density recording. CONSTITUTION: This polyester film has a laminated structure consisting of two or more layers and the total thickness is <=10μm. The outermost layer (A) on one side has <=10nm three-dimensional surface roughness SRa and <=150nm SRz. The outermost layer (B) on the other side has <=30nm three- dimensional surface roughness SRa and the thickness is <=30% of the total thickness of this film. The surface of the layer B has been lubricated.