5413-69-4

3,3′-Dimethylbenzidine double nitriding, First coupling with 3-Aminonaphthalene-2,7-disulfonic acid, again with 4-Aminonaphthalene-1-sulfonic acid matches. There are some type of dyes, part 4-Hydroxynaphthalene-1-sulfonic acid can be 6-Aminonaphthalene-2-sulfonic acid instead.

red. Soluble in water is palm red light, and adequate soluble in ethanol, insoluble in other organic solvents. The strong sulfuric acid for blue, Purple gray for diluted. The dye solution to join strong hydrochloric acid for brown, have precipitation; Add thick sodium hydroxide solution for palm light orange, precipitation.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	3	5	2	3-4		2