| 摘要 |
PROBLEM TO BE SOLVED: To improve the long-term dispersion stability, prevent the scorching in hot ink jet method, and obtain a good fixing on paper. SOLUTION: This ink contains water, a colorant (e.g. a carbon black), a dispersant having at least one group selected from among a sulfo group, a sulfuric ester group, and their salt groups (e.g. polystyrenesulfonic acid salt polymer), and a dispersant having carboxyl or its salt groups (e.g. a styrene- maleic acid salt polymer) in a wt. ratio of the former dispersant to the latter of (1:5)-(1:100). The sum of amts. of the dispersants contained is pref. 0.1-20 pts.wt. based on 10 pts.wt. colorant, and the ink pref. has a pH 7.0-10.0, a surface tension of 30-65mN/m, and a viscosity of 1.0-10.0mPa.s. |
