| 摘要 |
PURPOSE:To greatly improve C/N by executing calendering by metallic rolls in order to obtain a supersmooth magnetic layer by using ferromagnetic powder having <=200Angstrom crystal size. CONSTITUTION:A small amt. of a polishing agent having the hardness higher than Mohs hardness 9 is used in the magnetic layer to improve the packing ratio of the ferromagnetic metallic powder. A fine particle magnetic material having <=200Angstrom crystal size is used as the ferromagnetic metallic powder and further, the treatment by the metallic roll calendering is executed in order to extremely smooth the surface of the magnetic layer. Since the polishing material having the high hardness is uniformly dispersed in the magnetic layer, the durability of the magnetic layer is not deteriorated even if the surface of the magnetic layer is smoothed in such a manner. The long-term recording by the reduction in thickness is allowed by reducing the thickness over the entire part of the magnetic recording medium to <=13mum. Namely, the supersmooth magnetic layer is formed by using the fine particle magnetic material, by which the C/N is greatly improved and the durability is improved as well. |
