| 摘要 |
PURPOSE:To obtain a magnetic recording medium which maintains a lubricating function for a long period of time and has excellent wear resistance and durability by providing a magnetic layer contg. magnetic powder, prescribed solid polishing material, binder and specific compd. on a nonmagnetic base. CONSTITUTION:The magnetic layer contg. the magnetic powder, the solid polishing material holding an Al element on the surface and the polycyclic ketone compd. having at least two carbon rings of a non-condensation type is provided on the nonmagnetic base. The ketone compd. is expressed by the formulas I-III (where m, n are 3-8). The content of the ketone compd. is preferably 0.05-30pts.wt., more particularly preferably 0.5-5pts.wt. per 100pts. wt. magnetic powder. Al2O3 powder, nonmagnetic metallic powder or metallic oxide powder which is deposited with >=10wt% Al element on the surface is used for the solid polishing material and is incorporated into the magnetic layer at >=0.1wt% by the weight of the magnetic powder. Polyurethane, and various others are usable for the binder.
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