C.I. Direct Red 191

Amino acid methyl diazo, coupled with N,N’-bis(4-hydroxy-2-sulfonaphthalene-7-yl)urea.

yellow light red. Soluble in water for yellow light red, slightly soluble in ethanol and soluble fiber element, insoluble in other organic solvents. The strong sulfuric acid to red light purple, diluted for colourful red. The dye solution to join a little red 10% sulfuric acid solution; Add 10% sodium hydroxide solution for shallow blue light purplish red color.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
AATCC	5	5	5	2		4