| 摘要 |
PROBLEM TO BE SOLVED: To detect an unfair practice by laminating an infrared ray absorptive thermal recording layer consisting of specific phosphate white crystalline powder and a transparent coating layer laminated on one of the faces of a core base material and recording visible information through the process of heat generation to color formation or discoloration of an infrared ray absorptive photosensitive layer by the absorption of a near infrared ray or an infrared ray emitted through the transparent coating layer. SOLUTION: An information recording medium 1 consists of an information display part composed of an infrared absorptive thermal recording layer 3 on a core base material 2, and a less absorptive transparent coating layer 4 allowing permeation of lights in the visible ray, near infrared and infrared regions, laminated on the top of the information display part. Intrinsic and related information of the information recording medium 1 is recorded as an image in the information display part by inadiation with a laser beam in the near infrared and infrared regions. The infrared ray absorptive thermal recording layer 3 forming the information display part is composed mainly of diphosphorus pentaoxide, with phosphate white crystalline powder containing the cupric(Cu<2+> ) and/or the ferrous (Fe<2+> ). Further, these components are mixed with a binder, and all of these are applied to an area between the core base material 2 and the transparent coating layer 4 to form a layer. Finally the entire mixture is thermally pressurized so that it is welded by thermal fusion. |
