摘要 |
The present invention provides a process for producing beta-form pigmentary copper phthalocyanine comprising a) producing crude copper phthalocyanine by charging phthalic anhydride or phthalimide, urea, a copper compound and a catalyst, at a substantially continuous and uniform rate, into a reaction chamber containing dry, granular, pre-formed copper phthalocyanine, and removing the reaction product from the reaction chamber; and b) convening the crude copper phthalocyanine produced in step a) into pigmentary form, by milling it either in the dry state or in an aqueous medium; mixing the milled material with an aqueous emulsion comprising i) a liquid C6-C20 amine which is insoluble in water or alkali but is soluble in acid and ii) a surfactant capable of emulsifying the liquid amine; rendering the resulting mixture acidic to thereby dissolve the amine; and finally separating the desired pigmentary copper phthalocyanine from the treatment mixture.
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