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Method for preparing hexahydrophthalic anhydride

A technology of hexahydrophthalic anhydride and phthalic anhydride, which is applied in the field of fine chemical synthesis, can solve the problems of insufficient utilization of hexahydrophthalic anhydride, high requirements for catalyst hydrogenation activity, etc., achieves good economic benefits and industrial application prospects, improves productivity, and improves operation flexible effects

Active Publication Date: 2017-05-17
DALIAN UNIV OF TECH +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the requirements for catalyst hydrogenation activity are relatively high, and the existing hydrogenation of phthalic anhydride to produce hexahydrophthalic anhydride is not fully utilized.

Method used

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  • Method for preparing hexahydrophthalic anhydride
  • Method for preparing hexahydrophthalic anhydride
  • Method for preparing hexahydrophthalic anhydride

Examples

Experimental program
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Effect test

Embodiment 1

[0022] Example 1: Preparation of eggshell type PdRu catalyst to form Al 2 O 3 , MgO, ZnO, TiO 2 As carrier, with PdCl 2 And RuCl 3 It is a metal precursor that uses reactive deposition to prepare eggshell-type PdRu / Al 2 O 3 , PdRu / MgO, PdRu / ZnO, PdRu / TiO 2 Catalyst, reactive deposition is the use of rapid reduction reaction to deposit metal particles on the surface of the carrier. The metal ratio can be controlled by controlling the ratio of metal precursors. The eggshell catalyst can be controlled by controlling the system viscosity, carrier surface properties, and metal ion reduction speed. Layer thickness. By controlling experimental conditions, eggshell catalysts with different metal ratios and loadings were prepared. The eggshell catalyst is beneficial to the separation of the intermediate products of the hydrogenation reaction. For the hydrogenation of phthalic anhydride to prepare hexahydrophthalic anhydride, the eggshell catalyst can significantly improve the selectivity...

Embodiment 2

[0023] Example 2: Prepare different carrier eggshell type PdRu / Al with Pd loading of 0.1% and Ru loading of 0.8% 2 O 3 , PdRu / MgO, PdRu / ZnO, PdRu / TiO 2 The catalyst is used in the constant-pressure tank reaction to prepare hexahydrophthalic anhydride. For PdRu / Al 2 O 3 And PdRu / TiO 2 The catalyst, after reducing the above catalyst at 300℃ for 2h, pour it into a dioxane constant pressure reactor filled with 10% phthalic anhydride, and then add the auxiliary Na 2 CO 3 Or NaOH, the reaction conditions are: the reaction pressure is 10MPa, the reaction temperature is 100°C, the mass ratio of the substrate to the catalyst is 5:1, the reaction time is 8h, and the mass of the auxiliary agent is 5% of the substrate. The role of the auxiliary agent is: one is to inhibit the hydrolysis of phthalic anhydride and hexahydrophthalic anhydride, the second is to inhibit the hydrogenation of the side chain of p-phthalic anhydride, and the third is the water produced during the adsorption reaction. ...

Embodiment 3

[0026] Example 3: Eggshell PdRu / Al with Pd loading of 0.1% and Ru loading of 0.8% 2 O 3 The catalyst, after reducing the above catalyst at 300℃ for 2h, pour it into a constant pressure reactor containing 10% phthalic anhydride, dioxane, tetrahydrofuran, cyclohexane and decalin, and then add the auxiliary Na 2 CO 3 The reaction conditions are: reaction pressure 10MPa, reaction temperature 100°C, substrate to catalyst mass ratio 5:1, reaction time 8h, and auxiliary agent mass 5% of the substrate. Table 2 below shows the results of selective hydrogenation of phthalic anhydride to hexahydrophthalic anhydride as a solvent.

[0027]

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Abstract

The invention provides a method for preparing hexahydrophthalic anhydride, belonging to the field of synthesis of fine chemicals. The method comprises the steps: phthalic anhydride is heated to 50 DEG C and injected into a phthalic anhydride dissolving tower, the phthalic anhydride is dissolved with a solvent, the temperature of the dissolving tower is 50-70 DEG C, the dissolved phthalic anhydride solution is pressurized and injected into a constant-pressure reaction kettle or a fixed bed reactor filled with a selective hydrogenation catalyst to carry out selective hydrogenation reaction, the product directly enters a solvent recovery column after hydrogenation reaction, the solvent is distilled off at the tower top, the materials at the tower bottom enter a hexahydrophthalic anhydride rectifying tower, the hexahydrophthalic anhydride is obtained at the tower bottom, and a mixture of phthalide, o-toluic acid and o-methyl cyclohexanecarboxylic acid is obtained at the tower top; and the mixture obtained at the top of the rectifying tower is recrystallized to crystallize phthalide. The method has the advantages of simple operation, favorable economic benefit and industrial application prospects.

Description

Technical field [0001] The invention belongs to the field of fine chemical synthesis and relates to a method for preparing hexahydrophthalic anhydride. Background technique [0002] Hexahydrophthalic anhydride is an indispensable raw material for the production of high-grade polyester coatings. The amino alkyd paint produced by using hexahydrophthalic anhydride instead of aromatic polybasic acids can significantly improve the vividness and gloss of the coating, reduce the viscosity, and increase the solid content, especially Significantly improve the weather resistance of the coating. Hexahydrophthalic anhydride is also a raw material for the production of plasticizers, pesticides, and rust inhibitors. With the rapid development of the information industry, the quality requirements for semiconductor plastic packaging materials and potting materials are increasing, and the demand is increasing. Hexahydrophthalic anhydride has been widely used as an epoxy resin curing agent in thi...

Claims

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Application Information

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IPC IPC(8): C07D307/89C07D307/88B01J23/46B01J23/60B01J35/00
CPCC07D307/88C07D307/89B01J23/462B01J23/60B01J35/397
Inventor 梁长海闫桂林李洪岩李闯张海霞
Owner DALIAN UNIV OF TECH
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