4-Amino-3-hydroxy-7-nitronaphthalene-1-sulfonic acid diazo, and 7-Amino-4-hydroxynaphthalene-2-sulfonic acid coupling, and 2,4,6-Trichloro-1,3,5-triazine condensation, again ammoniation, make its forming metal complex (metal is the mixture of cobalt and chromium, also can use when complexation 2-Hydroxybenzoic acid).
Properties and Applications
black. Dark brown evenly powder. Solubility of 70 g/L (50 ℃). The strong sulfuric acid in blue, diluted for purple; Rare hydrochloric acid and sodium hydroxide solution in color. Used for cotton, hemp, polyamide fiber and viscose fabric such as printing and dyeing, not suitable for discharge.
