Direct blue 26, trisodium salt

3,3′-Dimethylbenzidine double nitriding, in alkaline conditions and 6-Amino-4-hydroxynaphthalene-2-sulfonic acid? coupling, and then diazo, and 4,5Dihydroxynaphthalene-1-sulfonic acid (2 Moore) coupled.

red light navy blue. Soluble in water for hidden cyan, soluble in ethanol. The strong sulfuric acid for blue, shallow purple for diluted. The dye solution to join strong hydrochloric acid have hidden cyan precipitation; Add thick sodium hydroxide solution has the purple precipitation.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	4-5	3	2	2-3		4
AATCC	4	2	2	1-2		2-3