| 摘要 |
PROBLEM TO BE SOLVED: To enable determination of authenticity by making confidential information emit fluorescence by black light, although the confidential information can not recognized visually under visible light, and also to enable determination of the authenticity by a simple method without using ultraviolet irradiation equipment. SOLUTION: A sheet for preventing forgery which has confidential information such as a character, a numeral, a figure, a sign or a pattern having transparency under visible light and formed of a transparent ink film emitting fluorescence under ultraviolet irradiation and of which the transparent ink film contains microcapsules of leuco dye crystal violet lactone. |
