Method for preparing 4-aminodiphenylamine

Abstract

The invention discloses a method for preparing 4-aminodiphenylamine, which comprises the following steps: (1) mixing aniline and an alkali water solution, and distilling out aniline-water azeotrope; (2) adding nitrobenzene to react; (3) adding water and a hydrogenation catalyst, and introducing hydrogen gas; (4) carrying out solid-liquid separation to separate the hydrogenation catalyst and a liquid phase, returning the hydrogenation catalyst to the step (3) or returning the hydrogenation catalyst to the step (3) after regeneration, separating the liquid phase to obtain an organic phase and an alkali water solution, rectifying the organic phase to obtain 4-aminodiphenylamine and aniline, and returning the aniline to the step (1); and (5) returning the alkali water solution to the step (1) or returning the alkali water solution to the step (1) after the alkali water solution is treated by activated carbon. In the method disclosed by the invention, the activated carbon is used for treating the circulating alkali water solution so as to remove impurities, thereby improving the purity of the circulating alkali water solution and avoiding the use of an expensive electrolytic process. Thus, the invention has the advantages of short process route and low equipment investment, is simple to operate, lowers the operating cost and reduces the environmental pollution.

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...

Examples

Embodiment 1

[0026] The method for preparing 4-aminodiphenylamine may further comprise the steps:

[0027] (1) 113 grams of 25% tetramethylammonium hydroxide aqueous solution is mixed in a condensation reactor, and the temperature is raised to 60° C. at a gauge pressure of 0.009MPa, then 142 grams of aniline are added, and the mixture is heated at a gauge pressure of 0.009MPa. Heat up to 80°C for distillation, and dehydrate in the form of aniline and water azeotrope until the molar ratio of water / tetramethylammonium hydroxide is 3:1;

[0028] (2) Add 35 grams of nitrobenzene to carry out condensation reaction within 2.5 hours. After adding nitrobenzene, continue to stir for 0.5 hours. At the same time, continue to distill aniline / water azeotrope under gauge pressure 0.009MPa and 80°C, and control the distillation Speed, water / tetramethylammonium hydroxide molar ratio > 0.7 at the end of the reaction;

[0029] (3) After the condensation reaction finishes, add 85 grams of water, 5 grams of ...

Embodiment 2

[0035] The method for preparing 4-aminodiphenylamine may further comprise the steps:

[0036] (1) 135 grams of mass percentage composition is 25% alkali aqueous solution (alkali is tetramethylammonium hydroxide, potassium hydroxide and tetramethylammonium chloride that mol ratio is 1: 0.5: 0.5) in condensation reactor Mix in medium, heat up to 60°C at a gauge pressure of 0.009MPa, then add 142 grams of aniline, heat up to 80°C for distillation at a gauge pressure of 0.009MPa, and dehydrate in the form of aniline and water azeotrope until the water / alkali molar ratio is 3:1 hour;

[0037] (2) Add 35 grams of nitrobenzene to carry out condensation reaction within 2.5 hours. After adding nitrobenzene, continue to stir for 0.5 hours. At the same time, continue to distill aniline / water azeotrope under gauge pressure 0.009MPa and 80°C, and control the distillation Speed, water / alkali molar ratio > 0.7 at the end of the reaction;

[0038] (3) After the condensation reaction finishe...

Embodiment 3

[0043] The method for preparing 4-aminodiphenylamine may further comprise the steps:

[0044] (1) Aniline and 5% aqueous alkali solution (alkali is a mixture of tetramethylammonium hydroxide, sodium hydroxide and tetramethylammonium bromide with a molar ratio of 1:0.2:0.3) are condensed Mix in the reactor, distill out the aniline-water azeotrope, make the mol ratio of water and alkali in the condensation reactor be 0.6:1;

[0045] (2) At 20°C and a gauge pressure of 0.005MPa, add nitrobenzene to the condensation reactor within 5 hours so that the molar ratio of aniline and nitrobenzene in the condensation reactor is 10:1, and react for 1 hour to form A mixed solution containing 4-nitrodiphenylamine and 4-nitrosodiphenylamine and / or their salts; the molar ratio of alkali to nitrobenzene is 0.7:1;

[0046] (3) add water, make the mass percent composition of alkali in water be 5%, add platinum / carbon catalyst (platinum mass content is 3%), the mass ratio of platinum / carbon catal...

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...

Examples

Embodiment 1

[0026] The method for preparing 4-aminodiphenylamine may further comprise the steps:

[0027] (1) 113 grams of 25% tetramethylammonium hydroxide aqueous solution is mixed in a condensation reactor, and the temperature is raised to 60° C. at a gauge pressure of 0.009MPa, then 142 grams of aniline are added, and the mixture is heated at a gauge pressure of 0.009MPa. Heat up to 80°C for distillation, and dehydrate in the form of aniline and water azeotrope until the molar ratio of water / tetramethylammonium hydroxide is 3:1;

[0028] (2) Add 35 grams of nitrobenzene to carry out condensation reaction within 2.5 hours. After adding nitrobenzene, continue to stir for 0.5 hours. At the same time, continue to distill aniline / water azeotrope under gauge pressure 0.009MPa and 80°C, and control the distillation Speed, water / tetramethylammonium hydroxide molar ratio > 0.7 at the end of the reaction;

[0029] (3) After the condensation reaction finishes, add 85 grams of water, 5 grams of ...

Embodiment 2

[0035] The method for preparing 4-aminodiphenylamine may further comprise the steps:

[0036] (1) 135 grams of mass percentage composition is 25% alkali aqueous solution (alkali is tetramethylammonium hydroxide, potassium hydroxide and tetramethylammonium chloride that mol ratio is 1: 0.5: 0.5) in condensation reactor Mix in medium, heat up to 60°C at a gauge pressure of 0.009MPa, then add 142 grams of aniline, heat up to 80°C for distillation at a gauge pressure of 0.009MPa, and dehydrate in the form of aniline and water azeotrope until the water / alkali molar ratio is 3:1 hour;

[0037] (2) Add 35 grams of nitrobenzene to carry out condensation reaction within 2.5 hours. After adding nitrobenzene, continue to stir for 0.5 hours. At the same time, continue to distill aniline / water azeotrope under gauge pressure 0.009MPa and 80°C, and control the distillation Speed, water / alkali molar ratio > 0.7 at the end of the reaction;

[0038] (3) After the condensation reaction finishe...

Embodiment 3

[0043] The method for preparing 4-aminodiphenylamine may further comprise the steps:

[0044] (1) Aniline and 5% aqueous alkali solution (alkali is a mixture of tetramethylammonium hydroxide, sodium hydroxide and tetramethylammonium bromide with a molar ratio of 1:0.2:0.3) are condensed Mix in the reactor, distill out the aniline-water azeotrope, make the mol ratio of water and alkali in the condensation reactor be 0.6:1;

[0045] (2) At 20°C and a gauge pressure of 0.005MPa, add nitrobenzene to the condensation reactor within 5 hours so that the molar ratio of aniline and nitrobenzene in the condensation reactor is 10:1, and react for 1 hour to form A mixed solution containing 4-nitrodiphenylamine and 4-nitrosodiphenylamine and / or their salts; the molar ratio of alkali to nitrobenzene is 0.7:1;

[0046] (3) add water, make the mass percent composition of alkali in water be 5%, add platinum / carbon catalyst (platinum mass content is 3%), the mass ratio of platinum / carbon catal...