3,3'-[1,1'-Biphenyl-4,4'-diylbis(azo)]bis(6-amino-4-hydroxynaphthalene-2-sulfonic acid sodium) salt

Preparation

4-(4-Aminophenyl)benzenamine double nitriding, in alkaline conditions and 6-Amino-4-hydroxynaphthalene-2-sulfonic acid? (2 Moore) coupled.

Properties and Applications

blue ash. Soluble in water (for violet black) and soluble fiber element, slightly soluble in ethanol is shallow purple, insoluble in other organic solvents. The strong sulfuric acid in blue, diluted for purple, have precipitation. The dye solution to join strong hydrochloric acid for dark, precipitation; Add thick sodium hydroxide solution for purplish red color, have precipitation.

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