| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an unrewritable magnetic recording medium with high magnetic shield power and a high output by using a magnetic body with the high magnetic shield power and low coercive force, forming a magnetic shield layer on a magnetic recording layer and forming an unrewritable magnetic recording layer on it. SOLUTION: The magnetic recording layer 2 containing the magnetic body with magnetic field strength higher than it applied when the unrewritable magnetic recording layer is formed and the coercive force of 800-5000 Oe is formed on non-magnetic base material 1 such as polyester resin, etc., to the thickness of 2-30μm. A shield layer 3 is applied on it by the magnetic body with the coercive force of 20 Oe or below to the prescribed thickness to prevent visibility, decipherment due to a third person, and paint containing the magnetic body with an average particle size of 20μm or below is applied on the shield layer 3 under a magnetic field saturating the magnetic shield layer, and a magnetically unrewritable magnetic signal recording layer 4 answering to a magnetic signal recorded on the magnetic recording layer 2 is formed. Thus, compatibility between sufficient magnetic shield power and a high output magnetic pattern becomes possible.</p> |
