Catalyst for preparing isocyanate by thermal decomposition of aryl (alkyl) carbamic acid ester and use thereof

A technology based on carbamate and carbamate, applied in the field of catalysts, can solve problems such as low product yield and catalyst separation, and achieve the effects of simple process operation, easy separation, and mild reaction conditions

Inactive Publication Date: 2007-08-08
CHENGDU ORGANIC CHEM CO LTD CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to realize a heterogeneous catalyst for preparing isocyanate by thermally decomposing carba

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Add 3.0g of methyl phenylcarbamate and 47.0g of solvent o-dichlorobenzene in the three-necked bottle to form a dispersion with a mass concentration of 6%, and add 0.15g of Bi 2 o 3 Catalyst, the amount added is 5% of the mass of methyl phenylcarbamate, the temperature of the reaction solution is raised to 180°C under nitrogen protection and stirring conditions, the reaction is carried out for 30 minutes, and the formed methanol is evaporated. After the reaction, the catalyst is filtered and reacted with liquid separation. After the reaction solution was treated with di-n-butylamine, it was analyzed by HPLC. The conversion rate of methyl phenylcarbamate was 95.8%, and the yield of phenylisocyanate was 87.6%.

Embodiment 2

[0028] Add 3.0g methyl phenylcarbamate and solvent o-dichlorobenzene 47.0g in three-necked bottle, form the dispersion liquid that mass concentration is 6%, add the Bi of 0.12g after the reaction recovery of example 1 simultaneously 2 o 3 Catalyst, the addition amount is 4% of the mass of methyl phenylcarbamate, the temperature of the reaction solution is raised to 180°C under the condition of nitrogen protection and stirring, the reaction is carried out for 30 minutes, and the formed methanol is distilled off. After the reaction, the catalyst is suction filtered and reacted with liquid separation. After the reaction solution was treated with di-n-butylamine, it was analyzed by HPLC. The conversion rate of methyl phenylcarbamate was 92.2%, and the yield of phenylisocyanate was 81.2%.

Embodiment 3

[0030] Add 3.0g methyl phenylcarbamate and solvent methyl benzoate 30.3g in the three-necked bottle, form the dispersion liquid that mass concentration is 9%, add the Bi of 0.15g simultaneously 2 o 3 Catalyst, the addition amount is 5% of the mass of methyl phenylcarbamate, the temperature of the reaction solution is raised to 195°C under nitrogen protection and stirring conditions, the reaction is carried out for 30 minutes, and the formed methanol is distilled off. After the reaction, the catalyst is suction filtered and reacted with liquid separation. After the reaction solution was treated with di-n-butylamine, it was analyzed by HPLC. The conversion rate of methyl phenylcarbamate was 91.4%, and the yield of phenylisocyanate was 83.2%.

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PUM

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Abstract

The invention discloses a making method of catalyst of isocyanate through heat decomposing aromatic amino formic ether, which is made of bismuth monomer, oxide, sulfate, halogen or salt. The method improves receiving rate and transmitting rate, which is easy to separate from reacting liquid.

Description

technical field [0001] The invention relates to a catalyst for preparing isocyanate by thermal decomposition of aryl (alkyl) carbamate and its application. The catalyst is elemental bismuth, oxide, sulfide, halide or salt. Using the material as a catalyst has the advantages of high raw material conversion rate and target product yield, easy separation from reaction solution, reusability and the like. technical background [0002] As a class of important organic reaction intermediates, isocyanates are widely used in industry, agriculture, medicine and health. Such compounds are widely used in the synthesis of polyurethane materials, carbamate insecticides, herbicides, etc. (Jiawen. Application and Market Prospect of Isocyanates at Home and Abroad. Formaldehyde and Methanol, 2002, 3, 20-28.). [0003] The traditional production method of isocyanate is mainly phosgene method, but phosgene is highly toxic, and a large amount of corrosive gas hydrogen chloride is produced by t...

Claims

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Application Information

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IPC IPC(8): B01J23/18B01J27/08B01J27/053B01J27/232B01J27/25C07C263/04C07C265/12C07C265/14
Inventor 王公应戴云生王庆印刘良明王越姚洁曾毅
Owner CHENGDU ORGANIC CHEM CO LTD CHINESE ACAD OF SCI
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