| 摘要 |
<p>PURPOSE:To prepare the titled ink keeping excellent jet stability even by repeating the jet printing for a long period and the pause for a lone period, by adding a specific N-formyl-N'-beta-hydroxyethylhydrazine to a mixture of a water-soluble direct dye, a specific wetting agent, water, etc. CONSTITUTION:The objective ink is prepared by adding (A) N-formul-N'-beta- hydroxyethylhydrazine of formula I to (B) an ink composed mainly of (i) a water-soluble direct dye and/or water-soluble acidic dye [preferably Direct Black 19 and/or dye of formula II (M is alkali metal, ammonium, quaternary ammonium substitued by aliphatic and/or aromatic group, formula III or formula IV], (ii) a wetting agent comprising an aliphatic polyhydric alcohol and/or its alkyl ether derivative (e.g. triethylene glycol), (iii) an antiseptic agent (e.g. sodium dehydroacetate) and (iv) water. The contents of the dye and the wetting agent in the whole ink composition are preferably 0.5-8.0wt% and 5.0-50.0wt%, respectively.</p> |
