Patent ID: 8430954
Filing Date: 2013-04-30
Classification: C09B,C09D

Abstract:
1. A pigment comprising 2,9-dimethoxyquinacridone and 2,9-dichloroquinacridone, made by the process comprising the steps of: a) heating a mixture of 2,5-di(4-methoxyanilino)terephthalic acid, and 2,5-di(4-chloroanilino)terephthalic acid in polyphosphoric acid at a temperature less than 105° C. to form a mixture of 2,9-dimethoxyquinacridone and 2,9-dichloroquinacridone; b) combining the mixture of 2,9-dimethoxyquinacridone and 2,9-dichloroquinacridone with water; and c) heating the mixture of 2,9-dimethoxyquinacridone and 2,9-dichloroquinacridone, wherein the pigment comprises crystal form Type II, crystal form Type III, or a mixture thereof.