Acid Brown 21

3-Amino-4-hydroxy-N-methylbenzenesulfonamide diazo, and N-(7-hydroxynaphthalen-1-yl)acetamide coupling, and the other will be 3-Amino-4-hydroxybenzenesulfonamide diazo, and 1-(4-Chlorophenyl)-3-methyl-1H-pyrazol-5(4H)-one?coupling, and then turn it into 1:2 chromium complex.

red light brown. Brown powder. The strong sulfuric acid for red sauce, diluted solution for red brown; No change in strong hydrochloric acid, diluted into shallow brown solution, and the precipitation; In the nitric acid for brown, sediment can dilute; In the thick of sodium hydroxide solution no change after dilute for brown. Water solution is brown. General for loose hair, tops and article polyamide, less used alone. Also used PVA fabric and dimension / cotton, wool / rayon blended fabric dyeing and printing, but also for leather dyeing.

Standard	Light Fastness	Soaping		Persperation Fastness	Oxygen bleaching		Fastness to seawater
		Fading	Stain		Fading	Stain	Fading	Stain
ISO	6-7	5	5	5	5	5	4-5	4-5