PROCESS FOR PREPARING COPPER PHTHALOCYANINE PIGMENTS OF THE A-MODIFICATION

摘要

PROCESS FOR PREPARING COPPER PHTHALOCYANINE PIGMENTS OF THE .alpha.-MODIFICATIONs Highly pure .alpha.-coppar phthalocyanine is obtained when a product regenerated from .alpha.-copper phthalocyanine sulfate by hydrolysis with water is aftertreated in an aqueous medium containing a polar organic non-aromatic compound which is water-soluble or liquid. The aftertreated product has an especially high tinctorial strength, is very easily disporsible and has a very pure reddish-blue shade.