DIRECT BLACK 22

Chemical Properties

black powder

Uses

Direct Black 22 is a polyimidazolium salt and an organic dye used in the textile industry. Direct Black 22 is considered a water pollutant, and is removed from wastewater by degradation.

Preparation

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 Benzene-1,3-diamine (2 Moore) coupled.

Properties and Applications

green and black. Blue gray powder. Soluble in water for violet black. The strong sulfuric acid for violet black, dilute black light after brown precipitation; In nitric acid solution for the red light brown in, precipitation. The dye solution to join strong hydrochloric acid have brown light black precipitation; Add thick sodium hydroxide solution for dark blue light red. Mainly used for cotton, viscose, wool/stick,nylon/rayon blended fabric dyeing and printing, also used in leather and paper dyeing.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	5	4	4	3		3
AATCC	5	4-5	5-6	3		3