| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an invisible information printing sheet capable of preventing invisible information from being visibly recognized, capable of visualizing easily the invisible information by rubbing with a hard currency, free from generation of shavings, and capable of precluding further more illegality from being executed. <P>SOLUTION: The invisible information printing sheet is printed with a printing portion due to an ink composition containing a material having 4.0 or more to 10.0 or less of Mohs hardness, and a printing portion due to scratch coloring ink containing a colorless or hypochromic electron donating dye precursor, an electron accepting compound and vanish, while both porions contact each other, on the same face of a support body, alternatively the invisible information printing sheet is provided with a printing portion due to ink containing the material having 4.0 or more to 10.0 or less of Mohs hardness, the colorless or hypochromic electron donating dye precursor, the electron accepting compound, and the vanish. <P>COPYRIGHT: (C)2010,JPO&INPIT |
