PREPARATION METHOD OF COLORANT FOR INK-JET INK USING HYDROPHOBIC DYE MATERIAL AND AMPHIPHILIC ELECTROLYTE AND COLORANT PREPARED BY THE METHOD

摘要

PURPOSE: A method for preparing a colorant and a colorant prepared by the method are provided, to obtain a colorant for an ink-jet ink which has no machine selectivity, a high light resistance and a high reliance and can be made with a low cost. CONSTITUTION: The method comprises the steps of dissolving a hydrophobic dye material in an organic solvent miscible with water to prepare a dye material solution containing 1-10 wt% of the dye material; contacting the dye material solution with an anion exchange resin and/or a cation exchange resin to prepare a purified dye material solution; dropping the purified dye material solution into a deionized water solution containing 10 wt% or less of an amphiphilic electrolyte with stirring to prepare a water-containing organic solvent solution of purified dye material; removing water and the organic solvent from the solution at a room temperature or under reduced pressure by azeotropic distillation with supplying deionized water and/or an organic solvent to obtain an aqueous solution of a dye material and an amphiphilic electrolyte; and centrifuging the aqueous solution with high speed. Preferably the hydrophobic dye material is an oil-soluble dye and the amphiphilic electrolyte is an amino acid.