| 摘要 |
<p>PURPOSE: To easily obtain information for judgment of authenticity of a magnetic recording medium and to prevent forgery by utilizing a continuous output change by the change in the degree of orientation of magnetic powder. CONSTITUTION: A magnetic recording layer is formed by applying a magnetic coating material 3 by a coating head 4 on a nonmagnetic base 2 delivered from an unwinding device 1. This magnetic coating material 3 contains the magnetic powder and binder resin as essential components and an org. solvent is used in combination therewith at need. Before the coating surface of the magnetic coating material 3 applied on the nonmagnetic base 2 dries, orientation patterns are formed by a magnetic field orienting device 5. The coating surface is then dried by a drying device 6 to fix the orientation and thereafter, the base 2 is taken up by a take-up device 7. the nonmagnetic base 2 is formed into a sheet form or corrugated form, for which a polyvinyl chloride, nylon, etc., are used. The magnetic powder used for the magnetic coating material 3 isγ-Fe2 O3 , Co-depositedγ-Fe2 O3 , etc. The information for judgment of the authenticity of the magnetic recording medium is easily obtd. and the process for production is extremely simple.</p> |
