| abstract |
(57) [Summary] [PROBLEMS] A hidden display that is invisible under visible light cannot be easily identified by an unspecified number of persons, and is also printed on a thermal paper type printing paper on which a hidden display is printed. To provide an ink composition for invisible identification which does not sometimes wear a heating element for printing. A binder component and 1,3,3,1 ', Selected from the group consisting of 3 ', 3'-hexamethylindocarbocyanine iodide and 5,5'-dichloro-11-diphenylamino-3,3-diethyl-10,12-ethylene-thiatricarbocyanine perchlorate It contains at least one laser dye and has a viscosity of 20 An invisible identification ink composition having a viscosity of 0 mPa ยท s or more. |