C.I. Direct Blue, heptasodium salt

5-Amino-2-(4-aminophenylamino)benzenesulfonic acid double nitriding, in alkaline conditions and 6-Amino-4-hydroxynaphthalene-2-sulfonic acid? (2 Moore) coupled, then double nitriding, and 4-Amino-5-hydroxynaphthalene-1,3-disulfonic acid (2 Moore) coupled:

navy blue. Soluble in water for dark red light blue, insoluble in organic solvents. The strong sulfuric acid for blue-ray gray, diluted dark purple solution for blue-ray, and accompanied by precipitation; In 10% of sulfuric acid for shallow dark. The dye solution to join 10% sodium hydroxide solution for shallow dark.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
AATCC	5	5	5	3		5