| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a water-based ink composition for writing utensil, which has an ink color tone visually checked from the outside, not impairing appearance caused by fading and browning, does not deteriorate color tone of writing and permanently forms an excellent writing, an ink cartridge having a built-in water-based ink composition and a writing utensil in a cartridge of a type in which ink is check visually and a writing utensil. <P>SOLUTION: The ink composition is stored in the ink cartridge to be visually checked from the outside or a writing utensil. The ink composition comprises at least water, a colorant and 5-mercapto-3-phenyl-1,3,4-thiadiazole-2-thione and/or its salt. The cartridge stores the water-based ink composition for writing utensil and has transparency. The writing utensil has a built-in cartridge in a transparent shaft cylinder. <P>COPYRIGHT: (C)2010,JPO&INPIT |
