3,3′-Dimethoxylbenzidine double nitriding, first and 3-Hydroxynaphthalene-2,7-disulfonic acid coupled , and then 4-Hydroxynaphthalene-1-sulfonic acid coupling.
Properties and Applications
blue. Soluble in water, soluble in alcohol. The strong sulfuric acid for blue, blue after diluted precipitation. The dye water solution is blue, to join the hydrochloric acid have precipitation of dark; Add sodium hydroxide solution for purplish red color.
