Magnetic metallic powder for magnetic recording and its manufacturing

Abstract

Abstract PURPOSE: To provide the high oxidation stability of the magnetic powder by effecting the wetting treatment of the magnetic metallic powder with organic solvent containing silicone oil and fatty acid and covering the powder surface with the oil and fatty acid evaporizing the solvent in a non-oxidizing gas. CONSTITUTION: In the ethanol solution dissolving 0.2% in weight of silicone oil and stearic acid respectively, the metallic magnetic powder having the particle diameter of about 0.3μm, axis ratio of about 7, saturated magnetizing amount of 160emu/g and coercive force of 1080 oersted, is charged to be dispersed and then filtrated. Then, the powder is heated at 150°C in the nitrogen gas atmosphere during 4 hours and the solvent is evaporated and cooled in such a way that the film composing of silicone oil and fatty acid is attached in the powder surface. By doing so, the saturated magnetizing amount when leaving in the air can remarkably reduced and storage stability can be improved. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Nariyuki Hosoo

Bibliographic Details