BINDER FOR MAGNETIC RECORDING MEDIUM AND MAGNETIC RECORDING MEDIUM

• Main Authors: OKADA TOMOYUKI, TSUSHIMA RIKIO, YAMASHITA KAZUTAKA, KANNEN NAOKI
• Format: Patent
• Language: English
• Published: 13.02.1987
• 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 improve the dispersibility of magnetic powder, surface smoothness and durability by consisting a binder of a polyurethane resin produced by using a lactone-modified diol. CONSTITUTION:The binder for a magnetic recording medium consisting of the polyurethane resin formed by using the lactone-modified diol expressed by the formula is used. A magnetic layer constituted by dispersing ferromagnetic powder into such binder is proved on a non-magnetic substrate. The polyure thane resin may be either of the polyurethane resin of which both terminals of the molecule are an isocyanate group and the resin of which one terminal is the isocyanate group and the other terminal is a hydroxyl group. The average mol.wt. thereof is relatively preferably in a 1,000-100,000 range. The proportion of the binder and the pulverous ferromagnetic powder. The performance of both the dispersibility and durability is thereby extremely improved.