| 摘要 |
PURPOSE:To prevent the roughening of the surface of a thin ferromagnetic metallic film which is a magnetic layer and to suppress the deterioration of reproduction output by specifying the surface roughnesses of the thin ferromagnetic metallic film and back coat layer. CONSTITUTION:The surface roughness of the thin ferromagnetic metallic film 2 of a magnetic recording medium having the thin ferromagnetic metallic film 2 of <=3,000Angstrom film thickness on one face of a nonmagnetic substrate 1 having 3.5-9mum thickness and the back coat layer 3 on the other face is specified to <=0.002mum center line average height Ra and the surface roughness of the back coat layer is specified to 0.004-0.035mum. The transfer of the ruggedness on the back coat layer to the surface of the thin ferromagnetic metallic film which is the magnetic layer is obviated and the roughening of the surface of the thin ferromagnetic metallic film is prevented even if the tape-like medium is coiled and prescribed or the cupping thereof is corrected by a hot roll, etc.
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