trisodium 2-[[2-amino-6-[[4'-[(3-carboxylato-4-hydroxyphenyl)azo]-3,3'-dimethoxy[1,1'-biphenyl]-4-yl]azo]-5-hydroxy-7-sulphonato-1-naphthyl]azo]-5-nitrobenzoate

Direct Black 91 is used as a jet-printing ink with improved storage stability and nozzle clogging resistance. Direct Black 91 is a cotton fiber dye.

3,3′-Dimethoxylbenzidine double nitriding, First coupled with 2-Hydroxybenzoic acid, coupled with the first again with 2-Amino-5-nitrobenzoic acid diazo, in acid conditions and 7-Amino-4-hydroxynaphthalene-2-sulfonic acid and coupled the product of coupling.

red light black. Black powder. Soluble in water, the solution for the red light black, hard to stability. In dyeing of copper (a slight change color in a dark colored light iron ion. Used for cotton, viscose and their blended fabric dyeing, can be in cotton or viscose fabric direct printing can and dispersal dyes with bath dyeing.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	4	5	6-7	4-5		5
AATCC			7	5