MAGNETIC RECORDING MEDIUM

• Main Author: SOMEZAWA MASASHI
• Format: Patent
• Language: English
• Published: 31.10.1989
• 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 obtain the recording medium having excellent durability by incorporating a specific acid or the salt thereof into a magnetic layer. CONSTITUTION:The magnetic layer 2 on a nonmagnetic base 1 is formed mainly of magnetic powder and binder into which the sulfophthalic acid or the salt thereof is incorporated. The sulfophthalic acid is phthalic acid, isophthalic acid or terephthalic acid introduced with sulfonic acid in any position of the benzene ring. The salt thereof is such that at least either of the carboxylic acid or sulfonic acid group in the molecule is in the form of a salt. Such salt generates a good interaction between the binders introduced with a neutral or basic polar group, by which the dispersibility of the magnetic powder and the boundary face reinforcement of a magnetic coating compd. are improved. The medium having the excellent durability is thus obtd. Sulfosalicylic acid may be used in place of the sulfophthalic acid.