| 摘要 |
<p>PURPOSE:To provide a water-based ink having specific pH value and extremely excellent water resistance, and resistant to the dissolution of the dye even by immersing in water after writing, by compounding a specific coloring material having sulfonanilide structure, a water-soluble organic solvent, and water. CONSTITUTION:The objective ink is prepared by mixing (A) a coloring material having sulfonailide structure of formula (Pc is metal-containing phthalocyanine residue; a is 2-4; b is 0-2; a+b is <=4; x is Na or K), (B) a water-soluble organic solvent (e.g. ethylene glycol) and (C) water, and adjusting the pH of the mixture at >=10 with a strong base such as sodium hydroxide. The amounts of the components (A)-(C) are pref. 0.5-20wt%, 5-50wt% and 50-95wt% of the ink, respectively. The component (A) is, e.g. copper phthalocyanine sulfonic acid anilide derivative, nickel phthalocyanine sulfonic acid anilide derivative, etc.</p> |
