Verfahren zur Aufarbeitung von bei der Herstellung von Phthalocyaninen erhaltenen Reaktionsgemischen

摘要

A phthalocyanine pigment is obtained from a synthesis product mixture containing an inert water and acid-insoluble organic solvent and synthesis by-products by adding per part by weight of phthalocyanine pigment at least 10 parts of 90 to 100% sulphuric acid at a non-sulphonating temperature of 30 DEG -80 DEG C., agitating to dissolve the pigment, separating the acid solution from the solvent phase and drowning the solution in 50 to 200 parts of water per part of pigment and at least 4 parts of water per part of acid, the organic solvent in the product mixture having a specific gravity such that it separates from the solution of phthalocyanine pigment in sulphuric acid. The synthesis product mixture may be diluted with additional water and acid insoluble organic solvent before addition of sulphuric acid. Separated residual solvent phase may be recycled to a pigment synthesis. Conventional methods of pigment preparation are described using inter alia phthalic acid derivatives, urea and a catalyst.