3,3′-Dimethoxylbenzidine double nitriding, first and 7-Hydroxynaphthalene-1-sulfonic acid, and then in three alkaline conditions and 4-Amino-5-hydroxynaphthalene-1-sulfonic acid coupling.
Properties and Applications
dark blue. Soluble in water for hidden cyan, soluble in ethanol for purple. The strong sulfuric acid for green light blue, blue for red after diluted. The dye solution to join strong hydrochloric acid as dark blue; Add thick sodium hydroxide solution for purple.
