AZO YELLOW

Preparation

4-Aminobenzenesulfonic acid diazo, with Diphenylamine coupling, and then using aqueous sodium nitrite processing, form N-and the nitro derivatives, then nitrification, into two or three nitro

Properties and Applications

red light yellow. Soluble in water for lemon yellow, soluble in ethanol for yellow, almost insoluble in benzene and ethyl ether. The strong sulfuric acid for quality of red, yellow and red to dilute solution, and immediately become yellow brown precipitation; In nitric acid solution by red to brown. The dye solution to join strong hydrochloric acid into brown and the rules precipitation; Add sodium hydroxide solution into yellow brown, then, appear tan precipitation. Used for wool, silk, polyamide fiber dyeing, also used in leather, paper and soap shading, its heavy metal salt used as organic pigments.