JPH0553843B

PURPOSE:To prepare a metal cobalt magnetic powder having good magnetic characteristics and suitable as a magnetic recording medium suitable for high density recording, by coating the surface of a plate shaped cobalt hydroxide powder with a sintering preventing agent while reducing the coated powder...

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Bibliographische Detailangaben
Hauptverfasser:	SUEYOSHI TOSHINOBU, NAONO HIROMITSU
Format:	Patent
Sprache:	eng
Schlagworte:	ADHESIVES ALLOYS BASIC ELECTRIC ELEMENTS CASTING CHEMICAL PAINT OR INK REMOVERS CHEMISTRY COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS CORRECTING FLUIDS DYES ELECTRICITY FERROUS OR NON-FERROUS ALLOYS 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 TREATMENT OF ALLOYS OR NON-FERROUS METALS USE OF MATERIALS THEREFOR WOODSTAINS WORKING METALLIC POWDER
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Beschreibung
Zusammenfassung:	PURPOSE:To prepare a metal cobalt magnetic powder having good magnetic characteristics and suitable as a magnetic recording medium suitable for high density recording, by coating the surface of a plate shaped cobalt hydroxide powder with a sintering preventing agent while reducing the coated powder under heating in a reductive atmosphere. CONSTITUTION:A plate shaped cobalt hydroxide powder is added and dispersed in an aqueous alkali solution in which a known sintering preventing agent is dissolved and, thereafter, CO2 gas is blown into said solution or an acid is added thereto to neutralize said solution. Whereby, the surface of the cobalt hydroxide powder is coated with a crystalline or amorphous sintering preventing coating. Because the shape of the plate shaped cobalt hydroxide powder particle is effectively held and the sintering between the particles is effectively suppressed, heating reduction is performed sufficiently well and reducing reaction is also uniformized. As a result, the plate shaped metal cobalt magnetic powder having high coercive force and high magnetic saturation susceptibility is obtained.