3-[(5-Chloro-2-hydroxy-4-nitrophenyl)azo]-4,5-dihydroxy-2,7-naphthalenedisulfonic acid disodium salt

Preparation

2-Amino-4-chloro-5-nitrophenol diazotization, with 4,5-Dihydroxynaphthalene-2,7-disulfonic acid coupling.

Properties and Applications

deep green light blue. Soluble in water for purple, slightly soluble in alcohol. In concentrated sulfuric acid for blue to black, dilution after pink to purple. Dye aqueous solution to join concentrated hydrochloric acid for magenta; Join strong caustic for red light blue.

Standard	Ironing Fastness	Light Fastness	Fulling		Persperation Fastness	Soaping	Water
			Alkali	Acid
ISO	5	5-6	5	2	3	4	4-5
AATCC	5	5-6	5		5	5	5