| 摘要 |
PURPOSE:To decrease coefft. of friction without decreasing S/N in particular and to improve runnability and durability by using a layer consisting of the inorg. powder dispersed in a binder and impregnated therein with silicone oil in constituting the back layer of a magnetic recording medium. CONSTITUTION:A back layer contg. inorg. powder, such as carbon black, graphite, MoS2, SiO2, talc or the like having <=0.8mu average particle size, 0.01- 10wt% silicone oil by the weight of the inorg. powder and a binder resin in a range of 4:1-0.1:1 by weight in the ratio between the inorg. powder and the binder is formed on the base of a magnetic recording medium on the side opposite from the surface provided with a magnetic layer. The back layer is so formed that the surface roughness thereof is <=0.1mu with respect to Ra (average roughness at the centerline) and that the thickness of the layer attains <=1.5mu. Then the transfer of the ruggedness on the back layer to the surface of the magnetic layer when the magnetic medium is wound into a roll or stacked in sheets and the consequent deterioration in the S/N characteristic are obviated and the recording medium having a good running characteristic, good lubricating performance, wear resistance and a long life is obtd. |
