| 摘要 |
PURPOSE:To improve magnetic characteristics, stability and video characteristics, by limiting the amount of a ferromagnetic metallic component of ferromagnetic metallic powder, constituting a magnetic recording medium, eluting into water to <=1,500ppm. CONSTITUTION:Ferromagnetic powder is produced by reducing alpha-Fe2O3, obtained by heating and decomposing alpha-FeOOH containing 5wt% Co, with hydrogen, and before it is taken out of the furnace, the partial pressure of oxygen in the furnace is increased gradually for a slow oxidiation treatment. The water solubility of metallic components of this material is 2,150ppm. Fe and 85ppm Co. Then, 500pts. ferromagnetic powder is steeped in 4,000pts. of 10%H2O2 for about three hours, and the solubility of metallic components after separation and drying is 120ppm Fe and 30ppm Co. Magnetic characterictics, stability and video characteristcis of a magetic tape produced by using this ferromagnetic powder and a suitable binder are superior to those of a tape using a ferromagnetic material which is not treated with H2O2. |
