| 摘要 |
PURPOSE:To improve electromagnetic conversion characteristics by providing a specific relation between the thickness of an upper magnetic layer and the shape of ferromagnetic powder. CONSTITUTION:This magnetic recording medium has the plural magnetic layers consisting of the lower magnetic layer contg. the ferromagnetic powder and binder on the surface of a nonmagnetic base and the upper magnetic layer provided thereon. The above-mentioned magnetic recording medium is so formed that the major axis length of the ferromagnetic powder incorporated into the upper magnetic layer is <=0.30mum, the crystallite size is <=400Angstrom and the drying thickness of the upper magnetic layer is <=1.2mum. The medium is also so formed that the center line average roughness Ra on the surface of the upper magnetic layer is <=0.015mum. Further preferably, the ratio between the major axis length and the crystallite size is >=3 and <=7, the dry thickness of the upper magnetic layer is <=30 times the crystallite size of the ferromagnetic powder of the ferromagnetic layer of the upper magnetic layer and the roughness Ra is <=1/20 times the major axis length of the ferromagnetic powder of the upper magnetic layer. |
