DURABLE MAGNETIC POWDER AND MAGNETIC RECORDING MEDIUM USING SAID POWDER

• Main Authors: SUEYOSHI TOSHINOBU, ASADA SEIICHI
• Format: Patent
• Language: English
• Published: 27.02.1989
• Subjects: ADHESIVES; CHEMICAL PAINT OR INK REMOVERS; CHEMISTRY; COATING COMPOSITIONS, e.g. PAINTS, VARNISHES ORLACQUERS; CORRECTING FLUIDS; DYES; FILLING PASTES; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; INKS; METALLURGY; MISCELLANEOUS APPLICATIONS OF MATERIALS; MISCELLANEOUS COMPOSITIONS; NATURAL RESINS; PAINTS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; PHYSICS; POLISHES; USE OF MATERIALS THEREFOR; WOODSTAINS

PURPOSE:To enhance the hardness of magnetic powder and to improve the durability of a magnetic recording medium by coating the surface of the magnetic powder with a Zr compd. CONSTITUTION:The Zr compd. is made to exist in the layer near the surface of the magnetic powder. Such a Zr oxide as represented by ZrO2 is general as the Zr compd. and the means for allowing said compd. to exist in the layer near the surface of the magnetic powder is arbitrary. The content of Zr as the Zr compd. is preferably 0.5-10wt.% based on the weight of the magnetic powder. Importation of sufficient hardness to the magnetic powder is not possible at <0.5wt.% and the saturation magnetization is deteriorated if the content exceeds 10wt.% and, therefore, such ratios are undesirable. The magnetic powder having the excellent durability and the magnetic recording medium are obtd. by increasing the surface hardness of the magnetic powder in such a manner.