| 摘要 |
<p>PURPOSE:To obtain the titled dye suitable for a recording liquid for ink-jet recording and usable without causing the clogging of nozzle, orifice, etc., nor depositing a precipitate to a heated head even at a high dye concentration, by adjusting the amount of Mg existing as an impurity below a specific level. CONSTITUTION:The objective dye contains a dye (e.g. C.I. Direct Black 17, C.I. Acid Black 2, 7, C.I. Basic Black 2, etc.) and Mg as an impurity, wherein the concentration of said Mg is adjusted to <=600ppm. The adjustment of the Mg content is carried out e.g. by adding sodium sulfate to an aqueous solution of the dye to effect the salting-out of the dye, separating the precipitate by filtration, washing with saturated solution of sodium sulfate, drying the cake, dissolving in an organic solvent, filtering the solution, concentrating the filtrate to dryness, dissolving in pure water and subjecting to cation exchange resin treatment.</p> |
