1H-Naphth[1,2-d]imidazole-8-sulfonic acid, 6-hydroxy-2-[3-[(2-hydroxy-6-sulfo-1-naphthalenyl)azo]phenyl]-7-(phenylazo)-, disodium salt

aniline diazo, and 2-(3-Aminophenyl)-6-hydroxynaphtho[2,1-d]thiazole-8-sulfonic acid?coupling, its product to diazo, and 6-Hydroxynaphthalene-2-sulfonic acid coupling.

yellow light red. Soluble in water for orange red to big red, soluble in ethanol for subtle stitching red light, insoluble in other organic solvents. The strong sulfuric acid in red for quality, to orange diluted. The dye solution is to add strong hydrochloric acid for orange red, precipitation; Add thick sodium hydroxide solution for orange brown.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	5	5	3	1		2