MAGNETIC POWDER FOR MAGNETIC RECORDING MEDIUM

• Main Author: KUBO OSAMU
• Format: Patent
• Language: English
• Published: 03.03.1992
• Subjects: ADHESIVES; BASIC ELECTRIC ELEMENTS; 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; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; PHYSICS; POLISHES; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS; USE OF MATERIALS THEREFOR; WOODSTAINS

PURPOSE:To decrease the quantity of the alkali ions remaining on a surface and to improve dispersibility, etc., by incorporating a glass forming element in the form of oxide at 0.01 to 0.5wt.% into the hexagonal ferrite magnetic powder magnetic obtd. by a wet process. CONSTITUTION:This magnetic powder is the hexagonal ferrite magnetic powder and contains the glass forming element in the form of the oxide at 0.01 to 0.5wt.% ratio. Since the glass forming element has the high solubility of the alkali ion to a glass forming material, the alkali ions adsorbed on the surface of the codeposit are easily diffused into the glass forming material at the time of crystallization of the magnetic powder. Since the affinity of the ions of alkaline earths is strong, the alkali ions adsorbed on the surface of the codeposit are thereby desorbed and are in turn bonded to the alkaline earth ions on the surface of the magnetic powder. Further, the desorbed alkali ions are easily diffused into the glass forming material. The quantity of the alkali ions adsorbed to remain on the surface of the magnetic powder is decreased and the dispersibility of the magnetic powder is improved.