| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a discoloring ink composition excellent for practical use, which maintains the initial stroke of handwriting indefinitely and at the same time can be discolored or decolored by painting a liquid for discoloring on the writing, and also to provide a writing implement having the above ink with a built-in form and a writing set comprising the above writing implement and a painting tool storing a discoloring liquid. <P>SOLUTION: The discoloring ink composition comprises at least water, a pigment which is discolored or decolored by a reducing agent, and an amino acid or its salt. The discoloring writing implement is in a form of a marking pen and contains the above ink composition with a built-in form. The writing set comprises the above writing implement and the painting tool storing the discoloring liquid. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
