PROCESS FOR THE TREATMENT OF EFFLUENT FROM THE SYNTHESIS OF COPPER PHTHALOCYANINE

1492086 Treatment of copper phthalocyanine process effluent BAYER AG 3 Oct 1975 [12 Oct 1974] 40587/75 Heading C4P The mother liquor obtained from the synthesis of copper phthalocyanine is adjusted to pH 3 to 9 and the precipitated products are separated. The process may be continuous. The copper phthalocyanine may be synthesized by the phthalic anhydride/urea process or processes using phthalodinitrile. The pH of the mother liquor is about 1. The precipitated products including copper salts, e.g. the hydroxide or basic copper salts, phthalimide and Mo may be recycled to the synthesis process to increase yield.