Acid Black 2
CAS Registry Number 8005-03-6
Synonyms C.I. 50420; Nigrosine
Chemical properties ：black with flash in the granular. Soluble in water, water solution is violet, sodium hydroxide solution to produce brown purple precipitation. Soluble in ethanol is blue. In strong sulfuric acid also is blue, diluted into purple, and the precipitation exhalation
Use ： mainly used for wool, silk dyeing, also used in leather dyeing (usually the chrome mordant dyeing), and paper, wood, soap, electrical-controlled aluminum coloring and manufacturing ink.
Mainly used for leather, silk and wool dyeing, also can be made into color which used to colour paper and printing