| 摘要 |
<p>PURPOSE:To provide water ink for jet printing, which does not cause clogging, by dissolving a water-soluble dye having a specified formula together with a mildewproofing agent and a wetting agent in water, the inorg. impurity content of said dye being adjusted to a specified amount. CONSTITUTION:A water-soluble dye of the formula, a mildewproofing agent and a wetting agent are dissolved in water to produce water ink, said dye containing 0.5wt% or less inorg. impurities. The removal of the inorg. impurities from said dye can be conducted by recrystallizing said dye from ethanol. An example of said mildewproofing agent is 2-pyridinethiol 1-oxide sodium salt (sodium omadine) which is added in an amount of 0.05-5wt%. An example of said wetting agent is ethylene glycol which is added in an amount of 10-30wt%. If desired, a chelating agent may be added. In this way, the clogging of nozzles and filters due to the association of the dye or mildewing can be prevented.</p> |
