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Preparation method of isocyanate

A technology of isocyanate and carbamate, applied in the preparation of isocyanic acid derivatives, preparation of organic compounds, chemical instruments and methods, etc., can solve the problems of harsh reaction conditions and many by-products, and achieve reduction of by-products and low price Low, the effect of improving product quality

Inactive Publication Date: 2005-03-09
LANZHOU INST OF CHEM PHYSICS CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to provide a kind of preparation method of isocyanate by overcoming the problems such as harsh reaction conditions and many by-products existing in the prior art

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] In the high-pressure reactor of 5000 milliliters, add reaction solvent nitrobenzene 1000ml, 1,6-hexamethylenediamine 100 grams, triethylamine (alkali) 650ml, keep carbon dioxide pressure and be 0.1MPa, under stirring room temperature reaction 2 hours, A mixed solution containing 1,6-hexanediamino formate was obtained. Subsequently, 180ml of phosphorus oxychloride (dehydrating agent) was dissolved in 1000ml of nitrobenzene, and the temperature of the dehydration reaction was controlled at 15° C., then the above mixed solution was added, and the reaction was terminated after 3 hours to obtain nitrobenzene, triethylamine and 1, The chromatographic analysis yield of the mixed solution of 6-hexamethylene diisocyanate is 87%, and the selectivity is greater than 98%.

Embodiment 2

[0025] Change the carbon dioxide pressure to 0.2MPa, change the dehydration reaction temperature to 5°C, replace 1,6-hexanediamine with dicyclohexylmethane-4,4'-diamine, and use the same operating conditions as in Example 1 to obtain dicyclohexylmethane -4,4'-diisocyanate, the chromatographic analysis yield is 69%, and the selectivity is greater than 98%.

Embodiment 3

[0027] Change the carbon dioxide pressure to 1.0MPa, change the dehydration reaction temperature to 10°C, replace 1,6-hexamethylenediamine with isophoronediamine, and use the same operating conditions as in Example 1 to obtain isophorone diisocyanate, which was obtained by chromatographic analysis. The rate is 79%, and the selectivity is greater than 98%.

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PUM

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Abstract

An improved process for preparing isocyanate features that amine, CO2, alkali and dewatering agent take part in reaction in solvent.

Description

technical field [0001] The present invention relates to the improvement of a kind of preparation method of isocyanate. Background technique [0002] As a class of important organic reaction intermediates, isocyanates are widely used in industry, agriculture, medicine and health. These compounds are widely used in the synthesis of polyisocyanates, polyurethanes, polyureas, polymer adhesives, insecticides, herbicides, etc. At the same time, the demand for various isocyanates continues to grow with the development of society. At present, isocyanates are mainly prepared by reacting corresponding amine compounds with phosgene. Phosgene is a highly toxic compound, and a large amount of highly corrosive hydrogen chloride is formed during the reaction. Therefore, it often leads to equipment corrosion, phosgene leakage, environmental pollution and personal injury. [0003] With the increasing environmental pollution around the world, governments of various countries are constantl...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C263/00C07C265/00
Inventor 邓友全石峰周瀚成陈楠
Owner LANZHOU INST OF CHEM PHYSICS CHINESE ACAD OF SCI