5-[[4'-[(6-Amino-1-hydroxy-3-sulfo-2-naphtyl)azo]-1,1'-biphenyl-4-yl]azo]-2-hydroxybenzoic acid disodium salt

Preparation

4-(4-Aminophenyl)benzenamine double nitriding, first with 2-Hydroxybenzoic acid coupling, and then in alkaline conditions and 7-Amino-4-hydroxynaphthalene-2-sulfonic acid coupling.

Properties and Applications

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

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