| 摘要 |
PURPOSE:To provide an invisible information record medium with which invisible information can be recorded, recorded information can be concealed without unnatural feeling, information is recorded in a thermal recording layer as an intermediate layer of the invisible information record medium by laser beam, and alteration of the record by a thermal head is impossible and forgery of the record can be prevented, and the surface shape does not change. CONSTITUTION:On a surface of a base material 1, an infrared ray absorbing ink layer 2 which has, for example, diphosphorus pentoxide as a main component and is made of phosphoric acid white crystal powder containing Fe<2+> and/or Cu<2+>, and a thermal recording layer 3 which is made of, for example, hollow microcapsule and has the same color as the infrared ray absorbing ink layer 2 and scatters the infrared rays at room temperature and increases its infrared ray transmission factor at heating with a heat higher than a predetermined temperature are layered. The base material 1 is further covered with a protective layer 4 made of infrared ray transmitting material. |
