Method for preparing 4,4'-dicyclohexyl methane 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

Inactive Publication Date: 2011-06-15
UPCHEM CHINA
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] 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

[0024] 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

[0026] 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

[0028] 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 organic compounds and in particular relates to a method for preparing dicyclohexyl methane diisocyanate by a non-phosgene method. In the method, 4,4'-diamino dicyclohexyl methane or an isomer mixture thereof or salt thereof or a mixture of amine and salt thereof, serving as a raw material, reacts with di(trichloromethyl)carbonic ester or trichloromethyl chloroformate or a mixture of the di(trichloromethyl)carbonic ester and the trichloromethyl chloroformate in an inert solvent. By the method, defects of long process route, complex technology, low safety and the like in the preparation of the 4,4'-dicyclohexyl methane diisocyanate by the traditional phosgene method are overcome. The method has the advantages of convenience of operation, high safety and environmental friendliness. In the method, reactants are charged and metered accurately and rate of charge is reduced, so production safety coefficient is improved. Tail gas is simple in treatment; hydrogen chloride gas generated by the reaction is absorbed by water; high-purity hydrochloric acid can be prepared; chloride ions can be utilized completely; and environmental friendliness is contributed.

Description

technical field [0001] 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 [0002] 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 also difficult to apply to high-performance polyurethane products because its performance is not as good as the former. h 12 The emergence of MDI can make up for the shortcomings of both IPDI and HDI. Dicyclohexylmethane diisocya...

Claims

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Application Information

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