Direct Brown 171

4-(4-Aminophenyl)benzenamine double nitriding, first and 2,4-Diamino-5-methylbenzenesulfonic acid coupling, and then and 4-Aminonaphthalene-1-sulfonic acid diazo, and Benzene-1,3-diamine coupled to accidentally coupled nitrogen compounds.

red light brown. Slightly soluble in water for orange brown, soluble in ethanol for yellow brown. The strong sulfuric acid for dark red to blue light in brown light purple, for yellow brown after diluted, precipitation. The dye solution to join strong hydrochloric acid have dark red light brown precipitation; Add thick sodium hydroxide solution for orange brown.

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