Preparation method of 4,4'-dicyclohexylmethane diisocyanate

A technology for dicyclohexylmethane and diaminodicyclohexylmethane is applied in the field of preparing 4,4'-dicyclohexylmethane diisocyanate by non-phosgene method, and can solve the problems of poor safety, complicated technology, long process route and the like, To achieve the effect of convenient operation, simplified process and simple exhaust gas treatment

Active Publication Date: 2015-05-27
UPCHEM CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The present invention aims at the defects of long process route, complex technology and poor safety in the preparation of 4,4'-dicyclohexylmethane diisocyanate by the traditional phosgene method, and provides a non-phosgene preparation method of dicyclohexylmethane diisocyanate , the method has the advantages of convenient operation, high safety and environmental friendliness

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] A solution of 400 ml in o-dichlorobenzene containing 210.4 g (1 mol) of 4,4'-diaminodicyclohexylmethane isomer mixture and 300 ml containing 396 g (1.34 mol) of bis(trichloromethyl) carbonate The o-dichlorobenzene solution was slowly added to a 2000 ml three-necked flask, and the temperature of the reaction system was controlled below 50 °C during the dropwise addition. After the dropwise addition, the temperature was raised to reflux for 3 hours. After the solvent was distilled off under reduced pressure, the distillate product at 163-174°C / 1.5 mmHg was collected by rectification. The content of 4,4'-dicyclohexylmethane diisocyanate isomer mixture was detected and analyzed by GC to be 97.5%, and the isocyanate value was determined to be 31.1 wt% (theoretical value was 32.1 wt%).

Embodiment 2

[0027] Slowly add 400 ml of benzonitrile solution containing 210.4 g (1 mol) of 4,4'-diaminodicyclohexylmethane isomer mixture to 300 ml of 396 g (1.34 mol) of bis(trichloromethyl)carbonic acid Benzonitrile solution of the ester. During the dropwise addition, the temperature of the reaction system was controlled below 50 °C. After the dropwise addition was completed, the temperature was raised to reflux, and kept at this temperature for 3 hours under reflux. After distilling off the solvent, rectification collects the distillate product at 160-176 ℃ / 1.5 mmHg. GC analysis showed that the content of 4,4'-dicyclohexylmethane diisocyanate isomer mixture was 83.2%. The isocyanate value was determined to be 26.7 wt% (theoretical 32.1 wt%).

Embodiment 3

[0029] Add 100 ml of benzonitrile to the reaction flask, heat up to 140 °C, dissolve 400 ml of benzonitrile containing 210.4 g (1 mole) of 4,4'-diaminodicyclohexylmethane isomer mixture into 250 ml of A benzonitrile solution of 148.6 g (0.5 mol) bis(trichloromethyl)carbonate was simultaneously added to the reaction flask. The dropwise addition was completed within 4 hours at 140°C, and then another 250 ml of benzonitrile solution containing 148.6 g (0.5 moles) of bis(trichloromethyl)carbonate was added dropwise at the same temperature, and kept warm for 3 hours after the addition was completed. After distilling off the solvent, rectification collected the distillate product at 163-175 ℃ / 1.5 mmHg. GC analysis showed that the content of 4,4’-dicyclohexylmethane diisocyanate isomer mixture was 98.5%, and the isocyanate value was determined to be 31.5 wt% (theoretical value was 32.1 wt%).

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Abstract

The invention belongs to the technical field of an organic compound, and particularly relates to a method for preparing 4,4'-dicyclohexylmethane diisocyanate by utilizing a non-phosgene process. The method comprises the following step: reacting 4,4'-dicyclohexylmethane diisocyanate or an isomer mixture or salt thereof, or a mixture of amine and salt thereof which are as raw materials with bis(trichloromethyl) carbonate or trichloromethyl chlorocarbonate or a mixture thereof in an inert solvent. By adopting the method disclosed by the invention, the defects that preparation of the 4,4'-dicyclohexylmethane diisocyanate by utilizing the traditional phosgene process is long in process route, complicated in technique, poor in safety and the like are overcome. The method disclosed by the invention has the advantages of being convenient to operate, high in safety, environment-friendly, and accurate in reactant feeding and metering, and the feeding ratio is reduced, so that the safety coefficient of production is improved. In addition, exhaust treatment is simple; high-purity hydrochloric acid can be prepared from a hydrogen chloride gas generated by water absorption reaction; chloridion can be fully utilized; environmental conservation is facilitated.

Description

[0001] This application is a divisional application with an application date of December 23, 2010, an application number of 201010602661.3, and an invention title of "Preparation Method of 4,4'-Dicyclohexylmethane Diisocyanate". technical field [0002] The invention belongs to the technical field of organic compounds, in particular to a method for preparing 4,4'-dicyclohexylmethane diisocyanate by a non-phosgene method. Background technique [0003] Dicyclohexylmethane diisocyanate, also known as hydrogenated MDI, or H 12 MDI is an aliphatic isocyanate. The polyurethane products made from it have excellent characteristics such as non-yellowing, light stability, weather resistance and high mechanical properties. Currently commonly used aliphatic isocyanates are isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI). Although the former has good performance, its high price has been difficult to popularize because it mainly relies on imports; and the latter is a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C265/14C07C263/10
Inventor 夏晨东高剑萍
Owner UPCHEM CHINA
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