| 摘要 |
PURPOSE:To improve traveling durability by providing specific two magnetic layers contg. ferromagnetic powder dispersed in a bonder on a nonmagnetic base. CONSTITUTION:This recording medium has two layers of the magnetic layers and the 2nd magnetic layer contains a polishing material having >=6 Mohs hardness and >=0.45mum average particle size and a polishing material having >=6 Mohs hardness and <=0.25mum average particle size. The 1st magnetic layer which is the lower layer is thicker than the 2nd magnetic layer which is the upper layer. The magnetic layer having the high packing density of the ferromagnetic powder and the excellent surface smoothness is thereby provided. The smoothness of the 2nd magnetic layer is, therefore, good. The degradation in the electromagnetic conversion characteristics is consequently obviated even if the polishing material which is effective for traveling durability and has a slightly large average particle size is used for the 2nd magnetic layer. Since the 2nd magnetic layer has the small layer thickness, the polishing material exists only near the surface over the entire part of the magnetic layer and the electromagnetic conversion characteristics over the entire part of the magnetic layer is hardly affected. The recording medium which is excellent in both the electromagnetic conversion characteristics and the traveling durability is thereby obtd. |
