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Preparation method of RT base condensation liquid

A technology of condensation reaction and condensation catalyst, which is applied to the preparation of amino compounds by condensation/addition reactions, chemical instruments and methods, organic compounds/hydrides/coordination complex catalysts, etc. Problems such as low selectivity of aniline

Active Publication Date: 2021-03-05
CHINA PETROLEUM & CHEM CORP +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] Ding Kehong et al. (Rare earth oxides catalyzed the condensation of aniline and nitrobenzene to prepare 4-aminodiphenylamine, rare earth [J], 31(3), 2010) mixed rare earth oxides with inorganic bases as RT base of nitrobenzene method Solid base catalyst for condensation reaction, due to La 2 o 3 and Y 2 o 3 Alkalinity is relatively strong, its catalytic effect is better, and the conversion rate of nitrobenzene is more than 80%, but the selectivity of the target product 4-(sub)nitrodiphenylamine is not high, about 50%, and the main product is azobenzene

Method used

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  • Preparation method of RT base condensation liquid
  • Preparation method of RT base condensation liquid

Examples

Experimental program
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Effect test

Embodiment 1

[0023] Catalyst preparation:

[0024] Add 100g of urotropine, 1000g of methanol, 300g of dimethyl carbonate, and 50g of molecular sieve into the reaction kettle, stir, control the reaction temperature at 110°C, react for 3 hours, filter and separate the reaction solution and molecular sieve; add 100g of hydrogen to the reaction solution Sodium oxide neutralization, temperature control 80 ℃, reaction time 0.5 hours; Concentrate the neutralization solution, the concentration temperature is 75 ℃, when the methanol content in the concentrated solution is 70%, cool down and crystallize, the crystallization temperature is 30 ℃, filter and separate; in the filtrate Add 600g of water to the mixture, distill under reduced pressure, the distillation temperature is 60°C, the pressure is -0.095MPa, and the methanol content in the liquid phase is controlled to 0.2%, to obtain 747g of RT base condensation catalyst. The hydroxide ion content was determined to be 6.17wt% by potentiometric tit...

Embodiment 2

[0026] Catalyst preparation:

[0027] Add 100g of urotropine, 2000g of methanol, 210g of dimethyl carbonate, and 20g of molecular sieve into the reaction kettle, stir, control the reaction temperature at 120°C, react for 1 hour, filter and separate the reaction solution and molecular sieve; add 90g of hydrogen to the reaction solution Sodium oxide neutralization, temperature control 80 ℃, reaction time 1 hour; Concentrate the neutralization solution, the concentration temperature is 85 ℃, when the methanol content in the concentrated solution is 70%, cool down and crystallize, the crystallization temperature is 30 ℃, filter and separate; in the filtrate Add 1800g of water to the mixture, distill under reduced pressure, the distillation temperature is 80°C, the pressure is -0.080MPa, the methanol content in the liquid phase is controlled to 0.02%, and 1629g of RT base condensation catalyst is obtained. The hydroxide ion content was determined to be 2.32wt% by potentiometric tit...

Embodiment 3

[0029] Condensate preparation:

[0030] Take 125.0g of RT base condensation catalyst prepared in Example 1, 150.0g of aniline, and 40.0g of nitrobenzene, and add them to the reactor, control the reaction vacuum pressure-0.092MPa, and the reaction temperature at 65°C to carry out the dehydration condensation reaction. The reaction time was 3 hours, and 188.3 g of a condensate was obtained. The content of each substance in the condensation liquid was analyzed by liquid chromatography: 44.57% of aniline, 0.12% of nitrobenzene, 26.41% of 4-nitrosodiphenylamine, 3.28% of 4-nitrodiphenylamine, 2.08% of azobenzene, and 0.05% of phenazine , Determination of 8.13% moisture in the condensation liquid, condensation fraction 126.7g. The conversion rate of nitrobenzene was calculated to be 95.89%, and the reaction selectivity was 93.11%.

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Abstract

The invention discloses a preparation method of an RT base condensation solution, which comprises the following steps: mixing an RT base condensation catalyst, aniline and nitrobenzene, and carrying out condensation reaction to prepare a 4-nitrosodiphenylamine and 4-nitrodiphenylamine condensation solution, wherein the RT base condensation catalyst is an aqueous solution of a mixture of tetramethyl hexamethylene tetraammonium hydroxide and trimethyl hexamethyleneamine triammonium hydroxide. The method solves the problem of environmental pollution caused by generation of a large amount of difficult-to-treat trimethylamine in the production process of the RT base by a nitrobenzene method, and when the process is used for condensation reaction, the conversion rate of nitrobenzene is more thanor equal to 95%, and the selectivity of 4-nitrodiphenylamine (nitrosodiphenylamine) is more than or equal to 92%.

Description

technical field [0001] The invention belongs to the field of fine chemicals, and in particular relates to a preparation method of RT base condensation liquid. Background technique [0002] RT base (p-aminodiphenylamine) is widely used in the fields of rubber additives, dyes, textiles, printing and pharmaceutical industries, and is mainly used in the production of rubber antioxidants IPPD, 6PPD, etc. At present, the production capacity of domestic RT base is 20kt / a. With the development of the rubber industry, the demand for rubber antioxidants is growing steadily. [0003] At present, the production of RT base mainly adopts the nitrobenzene process. The nitrobenzene method uses nitrobenzene and aniline as raw materials, and under the action of an organic base condensation catalyst, condenses to obtain 4-nitrosodiphenylamine and 4-nitrodiphenylamine condensation liquid, and the obtained condensation liquid is hydrogenated Reduction gives RT base. The nitrobenzene process ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C209/60C07C211/56C07D487/18B01J31/02
CPCC07C209/60C07D487/18B01J31/0282C07C211/56Y02P20/584
Inventor 陈永平袁维国吴其建刘卓
Owner CHINA PETROLEUM & CHEM CORP