Eriochrome Black A

Preparation

4-Amino-3-hydroxy-7-nitronaphthalene-1-sulfonic acid diazotization, and Naphthalen-2-ol coupling.

Properties and Applications

blue light gray to black. Black powder. Soluble in water for navy blue, in the water solubility 60 g/l (80 ℃), slightly soluble in ethanol and Acetone. In concentrated sulfuric acid for blue, yellow after diluted into light brown; In concentrated nitric acid for red orange. Its aqueous solution for navy blue, join concentrated hydrochloric acid to pale yellow light brown; Join strong caustic into orange brown. Dyeing wool in nitric acid into black light purple, and have a slight white streaks. Mainly used for wool fabric dyeing, also can be used for silk and nylon dyeing, also can be used for wool and a variety of fiber blended fabric dyeing, can be in acetic acid chromium pretreatment of wool fabric direct printing. Also used in the leather dyeing.

Standard	Ironing Fastness	Light Fastness	Fulling		Persperation Fastness	Soaping	Water
			Alkali	Acid
ISO	4-5		5	4-5	5	5	5
AATCC	4-5		4-5		5	5	5