| 摘要 |
PURPOSE:To obtain a medium which has a low coefft. of friction without spoiling the S/N characteristic thereof, obviates chipping, etc. and has good running durability by incorporating oxide powder as an oxide powder component and carbon black into powder. CONSTITUTION:The powder of a magnetic recording medium provided with a magnetic recording layer on one surface of a nonmagnetic base and a back layer formed by dispersing the powder into a binder on the other surface contains the oxide powder expressed by the general formulas M-1, M-2.O2+x (M-1 is at least one kind selected from Ba, Sr, Pb and Ca and M-2 is at least one kind selected from Ti, Zr and Sn, x is 0<=x<=0.9) or the oxide powder and carbon black. The oxide expressed by the general formulas M-1, M-2.O2+x has electrical conductivity and therefore solid solns. (>=2 kinds) are also usable as the oxide. The materials expressed by, for example, (BabPb1-b)TuO2+x(o<b<1), Sr(TicZr1-c)O2+x(0<c<1), etc. are also usable. The oxide is obtd. by reducing, for example, pulverous powder of BaTiO3 for 2hr at 800 deg.C in gaseous H2 flow. |
