Direct Blue 157

2′-Methoxy-4′-amino-5′-chlorooxanilic acid diazo, and 5-Aminonaphthalene-2-sulfonic acid coupling, product to diazo, and 7-Hydroxynaphthalene-2-sulfonic acid coupling, and then 2-(4-Aminophenylamino)-2-oxoacetic acid hydrolysis base, again diazo, and 4,5Dihydroxynaphthalene-1-sulfonic acid coupling.

dark blue. Soluble in water for blue, soluble in ethanol. concentrated sulfuric acid in olive green, diluted to blue. The dye solution with strong hydrochloric acid blue precipitation; Add thick dark for sodium hydroxide solution.

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