MANUFACTURE OF METALLIC MAGNETIC POWDER FOR MAGNETIC RECORDING

• Main Authors: MARUO MASATAKE, FUKITA TOKUO, KOYAMA ARATA
• Format: Patent
• Language: English
• Published: 06.03.1989
• Subjects: ADHESIVES; BASIC ELECTRIC ELEMENTS; CASTING; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; CORRECTING FLUIDS; DYES; ELECTRICITY; FILLING PASTES; INDUCTANCES; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; INKS; MAGNETS; MAKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; PERFORMING OPERATIONS; PHYSICS; POLISHES; POWDER METALLURGY; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS; TRANSPORTING; USE OF MATERIALS THEREFOR; WOODSTAINS; WORKING METALLIC POWDER

PURPOSE:To obtain metallic magnetic powder, the mutual sintering of particles of which is inhibited, particles of which retain their shapes and which has excellent magnetic characteristics, by applying a specific bonded treatment onto the surfaces of the particles of iron oxide hydrate or iron oxide and heating and reducing the whole after the application of the bonded treatment or after heating treatment. CONSTITUTION:A sodium hydroxide aqueous solution is added to aqueous slurry acquired by dispersing base body particles, the temperature of the whole is elevated and an ammonium zirconium carbonate aqueous solution is added, the temperature of the whole is raised and the whole is agitated for one hr and sulfuric acid is added, and the hydroxide precipitates of zirconium are applied onto the base body particles. A sodium aluminate aqueous solution is added to said treated slurry, sulfuric acid is added and the hydroxide precipitates of aluminum are applied onto the base body particles, and the aqueous solution is agitated and aged. A copper acetate aqueous solution is added to wet cake obtained by filtering and water-washing the applied treated slurry and kneaded, and the aqueous solution is dried. A dried matter is heated and treated at 550-900 deg.C, and reduced, thus acquiring metallic magnetic powder.