| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a water-based ink composition which decolors instantaneously during writing or just after writing to conceal written contents, and makes the concealed handwriting emit light so as to be visible by irradiation of ultraviolet rays. <P>SOLUTION: The water-based ink composition at least comprises a fluorescent whitener, a pH indicator having a phthalein skeleton, a basic substance, water, and at least one or more members selected from N-acylamino acid and/or a salt thereof, and N-acylmethyl taurine and/or a salt thereof. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
