| 摘要 |
PURPOSE:To improve traveling durability and wearing resistance of a back coating layer and a magnetic layer by incorporating carbon black of <=30nm particle size and >=300ml/100g DBP oil absorption and a lubricant into the back coating layer. CONSTITUTION:The carbon black having <=30nm particle size and >=300ml/100g DBP oil absorption has extremely high holding effect for a lubricant and allows the lubricant to ooze out from the back coating layer very slowly, little by little, for a long time. This increases the lubricating property and durability of the medium. Moreover, transfer of a rugged pattern of the back coating layer surface to a magnetic layer is prevented, and thereby, the obtd. magnetic recording medium has excellent traveling durability and wearing resistance of the back coating layer and the magnetic layer. It is more effective to preliminarily subject the carbon black to adsorption treatment with the lubricant, and thereby, the lubricant is enough adsorbed to the carbon black. Thus, lubricating property and durability can be further improved. |
