Method for preparing 4-aninodiphenylamine

A technology of aminodiphenylamine and aniline, which is applied in the field of preparation of 4-aminodiphenylamine, can solve the problems of expensive catalyst, low product purity, production scale limitation, etc., achieve high conversion rate and selectivity, continuous preparation process, reduce pollution effect

Inactive Publication Date: 2005-05-18
JIANGSU SINORGCHEM TECH CO LTD
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  • Abstract
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  • Application Information

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Problems solved by technology

These methods are to prepare 4-aminodiphenylamine with the mixture of the above raw materials by hydrogen hydrogenation in the presence of catalyzers, but there are some common shortcomings: the one, the selected catalyst is expensive, and the application of industrial scale production will cause the production cost to be too high , no advantage compared with the current production process
For example, the tetraalkylammonium hydroxide used in the condensation reaction and the noble metal palladium (Pd), platinum (Pt), rhodium (Rh) used in the hydrogenation reaction, etc., have few sources of raw materials and are extremely expensive.
Second, the operation is cumbersome, which is not conducive to continuous production, and the production scale is limited
Third, the product purity is not high

Method used

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  • Method for preparing 4-aninodiphenylamine

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038] At the same time, turn on the composite catalyst, aniline and nitrobenzene delivery pumps, adjust the flow rate to 150 kg / hour for aniline, 30 kg / hour for nitrobenzene, and 100 kg / hour for the composite alkali catalyst, and continuously enter the forced heat exchanger for forced heat exchange. The heat medium of the heat exchanger is alcohol vapor, and the condensed liquid in the heat exchanger is forced to enter the first-stage reactor from the top to continue dehydration and reaction, and then open the bottom valve of the first-stage reactor and the condensation circulation pump to adjust the outlet of the condensation circulation pump The valve makes the material return to the forced heat exchanger to form a partial circulation system, so that the material is continuously circulated, dehydrated and reacted. Control the reaction temperature to 75°C, the pressure (absolute pressure) to 0.008MPa, and control the circulating fluid flow rate to 2 meters 3 / Hour. As the r...

Embodiment 2

[0045] In a 500 ml three-necked flask equipped with a condenser and a stirrer, add 230 grams of water, add 91 grams of tetramethylammonium hydroxide (50%, 0.50 moles, the rest are water), 20 grams of sodium hydroxide in different order (0.5 mole), 52 grams (0.25 mole) of tetramethyl ammonium carbonate, control mixing temperature 72-77 (℃), stir evenly, promptly make composite type alkali catalyst, concentration 29.9 (weight %).

Embodiment 3

[0047] Get 46 grams of nickel powder, 51 grams of aluminum powder, and 3 grams of copper powder, melt in an induction furnace, discharge, cool, and roll into powder, process, sieve, and keep the mesh number at 40-300 mesh. In the there-necked flask of 500 milliliters, thermometer and stirrer are housed, and 375 gram concentration of charging is the NaOH aqueous solution of 20%, slowly adds the obtained powder, and reaction temperature is kept on 60 ℃, and the reaction time is 4 hours, and the back water washes catalyst to Neutral, that is, a composite powder catalyst.

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Abstract

The invention discloses a method for producing 4-aminodiphenylamine by using nitrobenzene and aniline as raw materials. The composite base catalyst and composite powder catalyst corresponding to condensation and hydrogenation reactions are respectively selected. The whole process consists of condensation, hydrogenation, The separation and recovery of the composite base catalyst and the recovery and recovery of the regenerated composite powder catalyst, the separation and recovery, and the application of hydrogenated solvent, aniline, and refining constitute a cyclic process flow, and the preparation method is continuously performed. The two catalysts selected in the present invention are cheap and have high catalytic activity; the reaction conditions are mild and the by-products are few; the whole preparation process is continuous, suitable for industrial-scale production, and the content of the prepared 4-aminodiphenylamine is higher than 99% (weight %) ), the yield of industrial scale production is higher than 92%.

Description

technical field [0001] The invention relates to a method for preparing 4-aminodiphenylamine, in particular to a method for continuously preparing 4-aminodiphenylamine by using nitrobenzene and aniline as raw materials, adopting two kinds of composite catalysts and a cyclic operation process flow. Background technique [0002] 4-aminodiphenylamine is an intermediate product of important antioxidants and stabilizers, and is an important chemical product in the rubber industry and polymer industry. According to the difference of raw materials used, at present, the method of producing 4-aminodiphenylamine has, (1 ) the aniline method, using p-nitrochlorobenzene and aniline as raw materials, reacting under the action of a catalyst to generate 4-nitrodiphenylamine, and then reducing it to 4-aminodiphenylamine with a sulfurized alkali. (2) formanilide method, with formic acid and aniline as raw material reaction to generate formanilide, then react with p-nitrochlorobenzene in the p...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01J31/02C07C209/36C07C209/60C07C211/55
Inventor 冯晓根
Owner JIANGSU SINORGCHEM TECH CO LTD
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