Production of an azine dye having excellent heat- and light-resistance

摘要

Disclosed is the process for the preparation of dye having excellent heat- and light-resistance. The dye can preferably be employed as a colorant for heat-resistant resin materials such as polyamide, as a colorant and a charge control agent for an electrostatic image developing toner (i.e. positively chargeable toner), and as a colorant for writing ink composition having a good aging stability. The process of the present invention comprising (a) mixing crude azine dye, produced by condensation of anilines or aniline hydrochlorides with nitrobenzenes in the presence of catalysts, with organic solvents; and (b) extracting by-products from the crude azine dye mixture.