disodium 7,7'-(carbonyldiimino)bis[3-[(3-aminophenyl)azo]-4-hydroxynaphthalene-2-sulphonate]

N-(3-aminophenyl)formamide (2 Moore) diazo, and N,N’-bis(4-hydroxy-2-sulfonaphthalene-7-yl)urea coupling, and then hydrolysis formex amino.

red. Soluble in water for red, slightly soluble in alcohol for Shallow red brown, insoluble in other organic solvents. The strong sulfuric acid for quality in red, with golden yellow to orange after diluted, orange precipitation; In nitric acid for red brown, then to yellow. The dye solution to join strong hydrochloric acid have brown light orange precipitation; Add thick sodium hydroxide solution for orange brown.

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