METHOD FOR PRODUCING DICHLOROQUINACRIDONE PIGMENT

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a yellowish red and transparent dichloroquinacridone pigment which requires less working for waste solvent treatment or recovery-recycling as compared to that in a conventional technology and which is envionmentally friendly.;SOLUTION: The method comprises cyclizing 2,5-di-(3-chloroanilino) terephthalic acid of 96% or more purity in polyphosphoric acid containing 85 mass% or more of phosphoric anhydride, followed by hydrolyzing, filtering the resultant, and heating the resultant solid in water. Due to characteristic hue and high transparency, the pigment can be used for coloring a printing ink, a paint, a plastic molded article, a pigment for inkjet, a tonor for statistic developing, a liquid crystal color filter, etc.;COPYRIGHT: (C)2007,JPO&INPIT