C.I. Vat Blue 42

sing 9-ethylcarbazole and p-nitrosophenol as raw materials, the two are first condensed in the presence of concentrated sulfuric acid at -23°C, reduced, and then refluxed with sodium polysulfide in a butanol medium to remove the butane After alcohol, oxidized, filtered, dried and crushed to obtain finished products. . Ethylcarbazole sulfate is obtained by melting 0.4mol ethylcarbazole and 325mL concentrated sulfuric acid at 70°C. Dissolve 0.41mol p-nitrosophenol and 325mL concentrated sulfuric acid at 10°C to obtain a nitrosophenol sulfuric acid solution. The ethylcarbazole sulfate and nitrosophenol sulfuric acid solution were reduced for 6h at -20°C, filtered to remove iron slag, and dried to obtain reduced leuco (I). Heat 200 mL of butanol, sodium sulfide, sulfur, and leuco body (I) together to 110°C and reflux for 24 hours, then add 4 g of sodium nitrite (95%), and continue to reflux for 2 hours. Steaming butanol, desulfurization, air oxidation, and drying to obtain products.

Sulfur-reduced blue GNX is mainly used for dyeing cotton, hemp, viscose fiber and Victoria cotton blended fabrics. It is also used for dyeing various blues with slightly greenish shade.