Production equipment and production technology of precursor of 4-aminodiphenylamine

Abstract

The invention relates to a production technology of a precursor of 4-aminodiphenylamine. The technology comprises the following steps: respectively processing and degassing nitrobenzene and phenylamine through an alkali metal oxide or a hydroxide; continuously feeding the processed phenylamine and concentrated quaternary ammonium alkali catalyst to a tubular condensation reactor by flow measurement according to a certain ratio after concentrating the quaternary ammonium alkali catalyst in vacuum; firstly, reacting the phenylamine to form aniline anions; continuously adding the processed nitrobenzene at different positions of the tubular condensation reactor from a plurality of points and controlling the water yield, so that the anions generate 4-nitrosodiphenylamine and 4-nitrodiphenylamine condensed liquid by replacing hydrogen reaction on nitrobenzene by nucleophilic addition. The technology disclosed by the invention is reasonable in steps and composition and advanced in equipment, and is used raw material enters a continuous production device of a high-efficiency reactor pipeline after being pretreated under a totally-enclosed condition, so as to produce the 4-nitrosodiphenylamine and the 4-nitrodiphenylamine.

Description

technical field [0001] The invention relates to a precursor of 4-aminodiphenylamine, which is specifically synthesized by directly reacting aniline with nitrobenzene. The reaction is initiated by a base, which forms an aniline anion through the reaction, and then the anion replaces the nitro group by nucleophilic addition. Production technology and equipment for preparing 4-nitrosodiphenylamine and 4-nitrodiphenylamine from hydrogen on benzene. Background technique [0002] 4-Nitrosodiphenylamine and 4-nitrodiphenylamine are widely used precursors for the production of 4-aminodiphenylamine with antiozonants, antioxidants and stabilizers. [0003] Most of the industrialized preparation of 4-nitrosodiphenylamine and 4-nitrodiphenylamine in the prior art uses quaternary ammonium hydroxide as a base to directly react aniline with nitrobenzene. Patent CN1193010A discloses a kind of in the presence of alkali and heterogeneous catalyst containing hydroxide and / or oxide group and i...

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Problems solved by technology

[0004] The present invention solves the problem that 4-nitrosodiphenylamine and 4-nitrodiphenylamine catalysts are easy to decompose and difficult to recycle by directly reacting aniline with nitrobenzene by using quaternary ammonium hydroxide as a base, further reducing energy consumption and raw materials. For the problem of consumption, provide a method that utilizes the known advantages and eliminates their disadvantages. The composition of the process steps is reasonable and the equipment is advanced. In a fully enclosed state, the raw materials used are pretreated and then enter the high-efficiency reactor pipeline continuous production device for production and preparation 4 —Nitrosodiphenylamine and 4-nitrodiphenylamine process

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