Process for producing dicyclohexyl methyl hydride diisocyanate and its midbody

A technology of dicyclohexylmethane and diaminodicyclohexylmethane, which is applied in the field of preparation of diisocyanate and its intermediates, can solve the problems of shortened catalyst life, increased production cost, and reduced catalyst activity, and achieve extended use Effects of longevity, reduction in toxicity, and reduction in production costs

Active Publication Date: 2009-05-13
WANHUA CHEMICAL (NINGBO) CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

When using this raw material, the impurities contained in the raw material such as isomers, oligomers and other impurities can lead to a rapid decrease in t

Method used

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  • Process for producing dicyclohexyl methyl hydride diisocyanate and its midbody
  • Process for producing dicyclohexyl methyl hydride diisocyanate and its midbody
  • Process for producing dicyclohexyl methyl hydride diisocyanate and its midbody

Examples

Experimental program
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Effect test

Embodiment 1

[0055] use figure 1In the process shown, the bicyclic MDA and polycyclic MDA from the condensation process of the diphenylmethane diisocyanate (MDI) plant are fully preheated to 220°C by the preheater and the falling film evaporator, and then enter the distillation tower with a diameter of 50mm , the column is filled with corrugated structured packing, the number of trays is 5, the bottom temperature is 250°C, the top temperature is 230°C and the top pressure is 3.5 mbar; the feed composition is 4,4'-diaminodiphenyl The methane content is 68wt%, the 2,4'-diaminodiphenylmethane content is 5wt%, and the polycyclic MDA is about 27wt%. The vapor phase material at the top of the distillation tower enters the middle of the rectification tower. The temperature at the bottom of the rectification tower is 244°C, the temperature at the top of the tower is 190°C, the temperature of the side line gas phase in the tower is 240°C, and the number of trays in the rectification tower is 25. ...

Embodiment 2

[0059] use figure 2 In the process shown, 4,4'-diaminodiphenylmethane content of 99.7wt% diaminodiphenylmethane and tetrahydrofuran are added to the autoclave at a mass ratio of 1:1, and 3wt% Rh / Al 2 o 3 The catalyst is added into the kettle, and the amount of the catalyst added accounts for 1.2wt% of the feeding amount of diaminodiphenylmethane. After replacing the reactor with nitrogen and hydrogen, fill the reactor with hydrogen to 5MPa, raise the temperature of the material in the reactor to 185°C, maintain the temperature, and maintain the hydrogen pressure in the reactor at 5MPa for 240 minutes. Cool down to 40°C and replace with pressure release, filter the reaction liquid in the kettle, flush the catalyst with trapped solids into the reaction kettle through backwashing operation and continue to be used for the hydrogenation reaction of the next batch, the main component of the filtrate It is a solution of diaminodicyclohexylmethane in tetrahydrofuran. The filtrat...

Embodiment 3

[0061] use figure 2 In the process shown, the diaminodiphenylmethane isomer mixture with a 4,4'-diaminodiphenylmethane content of 50.12wt% and cyclohexylamine are added to the high-pressure stirred tank at a mass ratio of 3:10. 5wt% Ru / C catalyst was added into the kettle, and the amount of catalyst added accounted for 5wt% of the feeding amount of diaminodiphenylmethane. After replacing the reactor with nitrogen and hydrogen, fill the reactor with hydrogen to 9MPa, raise the temperature of the material in the reactor to 180°C, maintain the temperature, and maintain the hydrogen pressure in the reactor at 9MPa for 360 minutes. After cooling and filtering, the filtrate sample was taken for gas chromatography analysis, and the content of diaminodiphenylmethane was 2.36wt%, and the content of diaminodicyclohexylmethane was 91.75wt%.

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Abstract

The invention discloses a method for preparing dicyclohexyl methane diisocyanate. The method comprises the following steps: a) a diamino diphenylmethane isomer mixture reacts in an organic solvent at a reaction temperature between 90 and 200 DEG C, under the hydrogen pressure between 3.0 and 12.0 MPa and under the action of a catalyst, so as to obtain a diamino dicyclohexyl methane isomer mixture; and b) the diamino dicyclohexyl methane isomer mixture obtained in the step a) and phosgene are heated to 330 to 400 DEG C so as to be gasify respectively and then are sent into a reactor with a mixing device to be mixed and react, have hydrogen chloride and phosgene removed, and are distilled, so as to obtain the dicyclohexyl methane diisocyanate. The method has the advantages of prolonging the life span of the catalyst and reducing cost. The invention also provides a complete technological process for preparing the dicyclohexyl methane diisocyanate.

Description

technical field [0001] The present invention relates to a preparation method of diisocyanate and its intermediate, in particular to a dicyclohexylmethane diisocyanate isomer with a 4,4'-dicyclohexylmethane diisocyanate mass percentage of 48%-100% Process for the preparation of mixtures and intermediates thereof. Background technique [0002] Diaminodicyclohexylmethane (H 12 MDA), also known as hydrogenated diaminodiphenylmethane, can be used in epoxy resin curing agent, and as the preparation of dicyclohexylmethane diisocyanate (H 12 MDI) raw material. Usually H 12 MDA can be obtained by catalytic hydrogenation of diaminodiphenylmethane at high pressure, followed by H 12 MDA can then be phosgenated to obtain H 12 MDI. [0003] And the starting material of preparing diaminodicyclohexylmethane generally adopts the higher homologue (abbreviation: polyamine, polycyclic MDA) that contains diaminodiphenylmethane (abbreviation: bicyclic MDA) and diaminodiphenyldiamine mixtur...

Claims

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Application Information

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IPC IPC(8): C07C265/14C07C263/10
Inventor 齐旺顺尚永华赵磊胡爽倪自林隋宝华罗务习王永胜华卫琦马德强
Owner WANHUA CHEMICAL (NINGBO) CO LTD
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