PROCESS FOR MANUFACTURING PIGMENTARY QUINACRIDONES

摘要

A process for preparing quinacridone pigments involving (a) preparing a reaction mixture of a substituted or unsubstituted 2,5-dianilino-terephthalic acid or ester thereof, and at least about 0.5 parts by weight of acid of a dehydrating agent; (b) combining the reaction mixture through one or more heated zones at a temperature of about 80 C to about 300 C; and (c) mixing the resulting crude quinacridone composition with a liquid in which the quinacridone pigment is substantially insoluble.