Vat dyestuff prepared from crude anthraquinone mixtures

摘要

Useful vat dyestuffs can be prepared by reacting a mixture of aminoanthraquinones containing 65-80% 1-aminoanthraquinone and 20-35% of a mixture containing 2-aminoanthraquinone and 1,5- and 1,8-diaminoanthraquinones with, for example, a halogenated benzanthrone or anthraquinone. The mixture of aminoanthraquinones can be obtained by nitrating anthraquinone in sulfuric acid and thereafter reducing the resulting nitroanthraquinones.