| 摘要 |
PURPOSE:To have polishing power and wear resistance and to improve durability by using alumina particles as a polishing material and incorporating benzoguanamine particles therein at 2-30wt% by the weight of the alumina particles. CONSTITUTION:The alpha-alumina and the benzoguanamine particles are used in combination. The average grain size of the benzoguanamine particles used is <=1mum, more preferably 0.05-0.3mum and the amt. thereof to be added is 2-30wt% by the weight of the alumina. There is no effect on the wear resistance if the amt. is <=2% and the packing degree of a magnetic material into a magnetic layer decreases and noise increases if the amt. is >=30%. Such amt. is, therefore, undesirable. The ferromagnetic powder which can be used is exemplified by gamma-Fe2O3, Co-contg. gamma-Fe2O3, Fe, Fe-Co, Fe-Ni, Co-Ni, Fe-Co-Ni, Fe-Co-B, Fe-Co-Cr-B, etc. The recording medium having the improved wear resistance and excellent durability is thus obtd.
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