MAGNETIC RECORDING MEDIUM AND MANUFACTURE THEREOF

摘要

PURPOSE:To prevent forging and illegal use by laminating a first magnetic layer comprising a magnetic material with a high coercive force exceeding 4,000 oersted and a second magnetic layer comprising a magnetic material with the coercive force of 250-3,700 oersted sequentially. CONSTITUTION:A first magnetic layer 2 which comprises a magnetic material with a high coercive force exceeding 4,000 oersted while having identification magnetic information for preventing forging is written previously is provided on a substrate 1 made of a non-magnetic material. A second magnetic layer 3 comprising a magnetic material with the coercive force of 200-3,700 oersted is provided on the layer and a protective film 4 is formed thereon. The orientation of both the magnetic layers is so arranged that the orientation of one of the magnetic layers is set in the direction of applying a coating body on the first or second magnetic layer and that of the other is set 40-50 deg. or 130-140 deg. with respect to the coating direction. The magnetic orientation of the layer 2 made different from the coating direction can raise the coercive force in the directions of coating on the layer 2 apparently thereby achieving higher security with improved characteristic of resisting external magnetic fields of the anti-forgery information.