| 摘要 |
PROBLEM TO BE SOLVED: To provide a refining method for inkjet grade type solvent-soluble dyes containing no salt nor solvent and so causing no nozzle clogging. SOLUTION: This method comprises (a) a mixing step of an aqueous press cake of a dye e.g. Solvent Black with a water-miscible liquid, (b) a step of distilling water to <=5 wt.% water content, (c) a step of filtrating a dye composition containing a solvent-soluble dye e.g. a 1:2 metal complex dye comprising e.g. a metal such as Cr and a water-miscible liquid e.g. polypropylene glycol and removing total insoluble contaminants and (d) a step of diluting the dye composition containing the solvent-soluble dyestuff and the water-miscible liquid with deionized water, precipitating the solvent-soluble dyestuff, filtrating, washing with the deionized water and separating thereafter. |
