2,4-Dinitrophenol?or its Sodium salt (by 1-Chloro-2,4-dinitrobenzene alkaline hydrolysis) and Sodium polysulfide heating, in 110 ~ 120 ℃ reflux heating 48 to 72 hours, or in 130 ~ 140 ℃ under pressure to short time heating, then dilution melt, adding acid or air oxidation make dye completely precipitated out. In the molten material to the intermediate Sodium polysulfide proportion must be appropriate, such ability in reaction end solution almost no dye residual. According to dye the preparation process of the use conditions, has determined the empirical formula is C24H16N6O8S7 orC24H16N6O8S8
Properties and Applications
green black and blue black. Black uniform powder. Insoluble in water and Etanol. In the Sodium sulfide solution solubility is good, for green black; Add Sodium hydroxide and Sodium sulfide solution of colour and lustre is blue; Add hydrochloric acid Sodium sulfide solution to have green black precipitation; In the cold part of concentrated sulfuric acid solution, after heating for deep green light blue, further heating into dark blue; In 25% of fuming sulfuric acid for black blue, dilution after green black precipitation. Dyeing content in alkaline insurance powder solution for yellow olive, after oxidation can restore the original colour and lustre; In Sodium hypochlorite solution all fade, join concentrated sulfuric acid no effect. Mainly used for cotton, vinylon/cotton blended fabric dyeing, and can also be used to hemp, viscose fiber dyeing.
