Vat dyes obtainable by bromination of dibenzanthrone and reaction with 1-aminoanthraquinone
AssigneeCiba-Geigy Corporation
InventorAthanassios Tzikas
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Abstract
Vat dyes which dye cellulosic material in a grey or black shade of good fastness properties are obtained by brominating dibenzanthrone in 80-100% sulfuric acid to a bromine content of 24 to 32%, and reacting the bromination product with 1-aminoanthraquinone.
Claims8
A process for the preparation of a vat dye which is a reaction product of brominated dibenzanthrone with 1-aminoanthraquinone, which process comprises brominating dibenzanthrone with bromine in 80-100% sulfuric acid and in the presence of a bromination catalyst to a bromine content of 24 to 32%, and reacting the bromination product with 1.5 to 2.0 moles of 1-aminoanthraquinone per mole of brominated dibenzanthrone.
Dependencies are inferred from the claim text.