| 摘要 |
PURPOSE: To obtain a magnetic recording medium which exhibits an output of high-frequency region equiv. to that of a vapor deposited tape in spite of a coating type, and has good electromagnetic conversion characteristics, such as C/N, and excellent traveling durability and a process for producing this medium at a good yield. CONSTITUTION: The average dry thickness (d) of an upper recording layer is >=1μm and the average value Δd of the thickness fluctuation at the boundary between an upper magnetic layer and a lower nonmagnetic layer is Δd<=d/2. The ferromagnetic powder of the upper recording layer is hexagonal-plate-like, its average plate diameter is 0.001 to 0.06μm and Hc is >=1000Oe. The Mohs hardness of the nonmagnetic powder of the lower nonmagnetic layer is >=3 and the average particle size thereof is <=0.5μm. The Ra of the resulted upper recording layer of this magnetic recording medium is <=20nm. This process for production comprises simultaneously or successively applying a coating liquid for the upper layer contg. the hexagonal planar ferromagnetic powder and a coating liquid for the lower layer contg. the nonmagntic powder having the Mohs hardness of >=3. |
