| 摘要 |
PROBLEM TO BE SOLVED: To obtain a medium which can maintain a const. frictional coefft. before and after travelling and has a high output characteristic by suppressing the blending amt. of carbon black at the min. or without blending the carbon black on an extremely thin uppermost magnetic layer and making silicone resin particles having a larger average primary particle size than the film thickness of the magnetic layer exist in a specific amount. SOLUTION: An intermediate layer 3 and a magnetic layer 4 as an uppermost layer are formed on one surface of a supporting body 2 and a back coating layer 5 is provided on the other surface. The magnetic layer 4 has a 0.05 to 0.5μm thickness and basically contains no carbon black. Even if the layer contains carbon black, its amt. is <=0.5 pts.wt. to 100 pts.wt. of ferromagnetic powder. Further, silicone resin particles having average particle size as 1.2 to 5 times as the thickness of the magnetic layer 4 are blended by 0.05 to 0.5 pts.wt. to 100 pts.wt. of the ferromagnetic powder into the magnetic layer 4. Thereby, good surface properties are obtd., low friction characteristics before or after repeated travelling can be maintained and high output characteristics can be achieved.
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