| 摘要 |
PURPOSE:To obtain a magnetic recording medium which excels in the anticorrosion performance, the driving stability and durability, by forming a back coat layer having the voids set within a specific percentage on the back side of a substrate containing a ferromagnetic thin metallic film on its surface and putting a lubricant into the void. CONSTITUTION:A filler of the fine powder of CaCO3, BaSO4, carbon black, MoS, etc. having 0.01-5mu grain sizes and different bulk densities is applied on the back side of a substrate containing a ferromagnetic thin metallic film on its surface together with the binder resin, an organic solvent, etc. and dried. Thus a back coat layer is obtained with the voids set within a 10-40% range. Then a lubricant of the fatty acid, fatty acid ester, silicone, etc. and especially an organic solvent solution of a lubricant having function groups COOH, PO(OH)2, etc. having affinity with the ferromagnetic thin film is applied or sprayed to the back coat layer. Thus a lubricant having a 10-80mg/m<2> range is put into the void. In such a way, a lubricant is permanently supplied to the ferromagnetic thin film. This improves the driving stability and durability of a magnetic recording medium. |
