Production method of 4-aminodiphenylamine

Abstract

The invention discloses a production method of 4-aminodiphenylamine, which comprises the following steps of: (1) mixing phenylamine and alkaline water solution, distilling out phenylamine-water azeotrope; (2) adding nitrobenzene for reaction; (3) adding water, Ni-B amorphous alloy catalyst, and filling hydrogen; (4) carrying out solid-liquid separation, separating out Ni-B amorphous alloy catalyst and liquid phase, and returning the Ni-B amorphous alloy catalyst back into the step (3); separating the liquid phase to obtain organic phase and alkaline water solution, carrying out rectification on the organic phase to obtain the product 4-aminodiphenylamine, recovering phenylamine, and returning the phenylamine back into the step (1); and (5) returning the alkaline water solution which is separated out back into the step (1), or treating the alkaline water solution by activated carbon and then returning back in the step (1). The method is simple, improves the purity of circulating alkaline water solution, avoids using expensive electrolytic process, shortens the process flow, is low in equipment investment, has simple operation, and can remarkably reduce the operation cost.

Description

technical field [0001] The present invention relates to a kind of production method of 4-aminodiphenylamine. Background technique [0002] p-4-aminodiphenylamine (4-aminodiphenylamine) is an important fine chemical intermediate, which can be used in rubber additives, dyes, textiles, printing and pharmaceutical industries, etc., mainly used in the production of p-phenylenediamine rubber anti-aging Agent 4010NA, 4020, etc. There are four main production processes for p-4-aminodiphenylamine: aniline method, diphenylamine method, formanilide method and nitrobenzene method. Each of the four routes has its own characteristics. The aniline method is simple in process and low in cost, but has high reaction temperature, many side reactions, and poor product quality. The diphenylamine method mainly uses diphenylamine as a raw material. In the presence of inorganic acids, nitrosation is carried out with nitrite in an organic solvent to obtain N-nitrosodiphenylamine, which is then rea...

AI Technical Summary

Problems solved by technology

The four routes have their own characteristics. The aniline method is simple in process and low in cost, but the reaction temperature is high, side reactions are many, and the product quality is poor.

[0014] Although the electrolysis method can significantly improve the purity of the aqueous solution containing tetramethylammonium hydroxide, the investment in the electrolysis method equipment is very large, the power consumption is large, and the operating cost is high. Sometimes, fouling occurs on the anode during the electrolysis process and the electrolysis stops

[0015] Another shortcoming of this method is, use noble metal catalyst; In the reactor, in the presence of noble metal catalysts and co-catalysts, it is hydrogenated and reduced to aniline, and then recycled and applied to the condensation reaction

Although this method can reclaim azobenzene and improve the yield, it will increase the equipment, the process route will be long, and the investment and production costs will be increased.