PHOSPHITE ANTIOXIDANT, AND MAGNETIC RECORDING MEDIUM CONTAINING SAME

• Main Authors: MIYATA ICHIJI, SASAMOTO SAYAKA, NISHIHARA SHOJI
• Format: Patent
• Language: English
• Published: 02.03.1993
• 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; MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FORELSEWHERE; 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 prepare a magnetic recording medium which is sufficiently oxidation-resistant and hence sufficiently controlled in the staining of a magnetic head and drop out by incorporating a specific phosphite antioxidant into a magnetic layer contg. a magnetic metal power. CONSTITUTION:A phosphite antioxidant which has at least one phosphorus (III) atom and at lest one alkyl group having at least three methyl groups and bonded to the phosphorus atom through an oxygen atom in the molecule (and is prepd. by reacting an acid chloride of phosphorous acid, e.g. phosphorus trichoride or an alkylated phosphorus trichloride, with an alcohol having at least three methyl groups and dehydrochlorinating the reaction product) is incorporated into a magnetic layer contg. a magnetic metal powder to give a magnetic recording medium, which is highly reliable since it does not stain a magnetic head and hardly causes drop-out.