| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ink-jet ink which can retain the initial printing performance, even after long-term use, and can form safe, clear images on food, eggs, pharmaceuticals, etc. <P>SOLUTION: The ink-jet ink comprises at least water and a food dye chosen from sodium iron chlorophyllin and/or sodium copper chlorophyllin purified through ultrafiltration. Here, cross-flow ultrafiltration method using a ceramic or polypropylene membrane is employed. <P>COPYRIGHT: (C)2003,JPO |
