Bismarck brown R-Basic brown 4

red light brown. For yellow brown is soluble in water, soluble in ethanol and soluble fiber element, slightly soluble in acetone, insoluble in benzene. The strong sulfuric acid for brown, diluted into a red light brown; In nitric acid solution for purple, to brown; In strong hydrochloric acid for purple solution (don’t). The dye solution to join strong hydrochloric acid for yellow brown; Add 10% sodium hydroxide solution into orange. Mainly used for silk, wool fabric dyeing, also used in leather and paper color