| 摘要 |
PURPOSE:To improve the dispersibility of fine ferromagnetic material powder into a binder so that a magnetic layer having high S/N is obtd. by using respectively specific fine ferromagnetic metallic powder and binder and to lower the surface electric resistance of the magnetic layer so that the electrostatic chargeability thereof and drop-outs are decreased by improving the surface characteristic of the magnetic layer. CONSTITUTION:The fine ferromagnetic metallic powder of a magnetic recording medium provided with the magnetic layer formed by uniformly dispersing the fine ferromagnetic material powder into the binder on a nonmagnetic base is the fine ferromagnetic metallic powder having >=45m<2>/g SBET, >=1,000Oe coercive force and >=7 acicular ratio and further,the binder consists of a polymer which contains the polar group expressed by formula I and has the mol. wt. within a 10,000-100,000 range. The ratio (weight) of the fine ferromagnetic material powder and the binder is 2.5-10. The dispersibility of the respective components in a coating liquid for formation of the magnetic layer is thereby improved. As a result, the surface electric resistance of particularly the magnetic layer of the magnetic recording medium having good video S/N is low and, therefore, the drop-outs are less increased.
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