C.I. Direct red 42

4-(4-Aminophenyl)benzenamine double nitriding, first and 6-Aminonaphthalene-1,3-disulfonic acid?coupling, and then in alkaline conditions and 7-Amino-4-hydroxynaphthalene-2-sulfonic acid coupling.

dark blue light red. Soluble in water for product red, slightly soluble in ethanol for shallow peachblossom. The strong sulfuric acid in blue, diluted for Shallow red time The dye solution to join strong hydrochloric acid for red light brown, have precipitation; Add thick sodium hydroxide solution for orange brown.

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