MAGNETIC RECORDING MEDIUM AND ITS MANUFACTURE

• Main Authors: SUZUKI MASAYASU, ISHIGAKI KAZUO, MOCHIZUKI TAKESHI
• Format: Patent
• Language: English
• Published: 16.01.1990
• 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 a magnetic recording medium having excellent charac- teristics against counterfeiting by inserting deciding information, which cannot be added or erased later, to a magnetic recording medium when a magnetic coating is applied. CONSTITUTION:On a substrate consisting of a non-magnetic substance, a first magnetic layer, which consists of a magnetic substance having higher coercive force than that of the ordinarily used magnetic recording material, namely, the higher coercive force than 3000 oersted, and to which discriminating magnetic information for counterfeiting prevention has been written beforehand, is provided. Further, a second magnetic layer consisting of the ordinarily used magnetic substance is laminated as the magnetic recording material. Since the first magnetic layer consists of the magnetic substance at the high coercive force, which is ordinarily used as the magnetic recording material, the magnetic recording and erasing is difficult by a generally used magnetic head or a permanent magnet excluding a period before the magnetic layer at the time of the coating is dried. Thus, the counterfeiting and unjust use are made difficult.