| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an information recording medium simultaneously having the ease of discriminating forgery and the difficulty of forgery and alteration by depositing an amorphous ferromagnetic material layer on a hologram forming layer consisting of a resin by sputtering, etc. SOLUTION: This information recording medium has a protective layer 1 consisting of a polyethylene transparent resin having a thickness of about several tensμm. The embossing type hologram forming layer 2 on which embossing patterns are written and has a thickness of about severalμm is, for example, a UV curing type UV resin. The amorphous ferromagnetic material layer 3 having a thickness of about several tensμm is deposited by sputtering and evaporation on the hologram forming layer 2 and is formed as a reflection layer. The amorphous ferromagnetic material layer 3 is formed by sputtering using a ternary or quaternary alloy essentially consisting of cobalt Co or iron Fe as a target material. The alloy varying in the history characteristics of Hc (coercive force),μ(magnetic permeability), Bm (saturation magnetic flux density) and B-H characteristic (hysteresis curve) is used. Further, the recording medium is provided with an adhesive material layer 4 for adhering the medium to paper, cards, etc.</p> |
