Method for preparing m-xylylenediamine

A technology of m-xylylenediamine and isophthalonitrile, which is applied in the field of m-xylylenediamine preparation, can solve the problems of unspecified main composition of impurities, equipment manufacturing, high material requirements, and unsatisfactory XDA yield, etc. , to achieve the effect of compact equipment, scientific process and mild operating conditions

Active Publication Date: 2010-07-14
WANHUA CHEM GRP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The catalyst cost of this method is high, easy to be poisoned and deactivated, and needs to be operated under high pressure, which requires high equipment

Method used

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  • Method for preparing m-xylylenediamine
  • Method for preparing m-xylylenediamine
  • Method for preparing m-xylylenediamine

Examples

Experimental program
Comparison scheme
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Example Embodiment

[0031] Catalyst preparation

[0032] Catalyst One

[0033] Weigh 101g of hydrated cobalt chloride, 28g of hydrated nickel chloride, 11g of hydrated titanium chloride, 20mg of hydrated rhodium chloride, 3.6g of hydrated manganese chloride, and 2.7g of hydrated chromium chloride to prepare a solution. On 100g diatomaceous earth, after drying under infrared light, layering is formed and dried for later use.

[0034] Catalyst two

[0035] Weigh 101g of hydrated cobalt chloride, 28g of hydrated nickel chloride, 11g of hydrated titanium chloride, 20mg of hydrated rhodium chloride, 4.0g of potassium molybdate to prepare a solution, and immerse it on 100g of diatomaceous earth using the dipping method. After drying under the lamp, the strips are formed and dried for later use.

Example Embodiment

[0036] Example 1

[0037] The hydrogenation reactor is a stainless steel tubular reactor with a diameter of 25mm×1500mm. The reaction tube is filled with 80ml of catalyst one with a particle size of 0.6-1mm, and the bottom of the reaction tube is filled with inert quartz sand. The catalyst was reduced by a mixture of hydrogen and nitrogen (volume ratio 1:10) under normal pressure at 600°C for 3 hours before use.

[0038] The mixture of isophthalonitrile (500g) and N-methylpyrrolidone (NMP) (2760ml) (isophthalonitrile content is 15%) is fed into the reactor from the top at a set speed, liquid ammonia (The flow rate is 47.5ml / min) and hydrogen (41.2 standard liters / H) are supplied from the other two pipelines. The raw materials are mixed with hydrogen and liquid ammonia and enter the bed containing the catalyst for hydrogenation reaction. The reaction temperature is 75°C, the reaction pressure is 8Mpa, the addition amount of isophthalonitrile is 9g / h, the liquid ammonia flow rate i...

Example Embodiment

[0039] Example 2

[0040] According to the equipment and catalyst used in Example 1, isophthalonitrile (500 g) was dissolved in 2650 ml of N-methylpyrrolidone (NMP), and the hydrogenation reaction was carried out on the fixed bed and the hydrogenation reaction was carried out on the fixed bed. The reaction temperature is 85°C, the reaction pressure is 8Mpa, the addition amount of isophthalonitrile is maintained at 13g / h, and the hydrogen flow rate is controlled to 41.2 standard liters / H under the condition of no ammonia. The reaction solution was collected and analyzed, and the results are shown in Table 1.

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PUM

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Abstract

The invention discloses a method for preparing m-xylylenediamine. The method includes the following steps that: a fixed-bed hydrogenation reactor is adopted, and isophthalonitrile is dissolved in organic acid amide solvent, and then enters a bed containing catalyst in the form of solution to react with hydrogen under the conditions of the reaction temperature of 50 DEG C to 100 DEG C, preferably 70 DEG C to 90 DEG C, and the reaction pressure of 5MPa to 10 MPa, preferably 7MPa to 8MPa, so that the m-xylylenediamine is prepared. Xylyl diisocyanate (XDI) can be directly prepared by the liquid phase salifying phosgenation method without refining and separating the prepared m-xylylenediamine reaction liquid; the method improves the prior XDA production technique, energy is saved, emission is reduced, the reaction conditions are mild, selectivity is high, the prepared m-xylylenediamine can be directly used for phosgenation reaction without being refined and purified.

Description

technical field [0001] The invention relates to a preparation method of m-xylylenediamine (XDA), in particular to a method of m-xylylenediamine which can be directly used for phosgenation reaction to prepare m-xylylene diisocyanate (XDI). Background technique [0002] m-xylylenediamine (m-xylyenediamine, XDA, molecule C 8 h 12 N 2 ) is an aliphatic amine containing an aromatic ring, it is a colorless liquid with a slightly bitter almond flavor at room temperature. [0003] An important application of m-xylylenediamine is the synthesis of the organic isocyanate m-xylene diisocyanate (XDI). In addition to the characteristics of low vapor pressure and high reactivity of XDI, because the isocyanate group in its molecular structure is not directly connected to the benzene ring but is separated by a methyl group, which prevents the resonance between the benzene ring and isocyanate, making it prepared by XDI The polyurethane products of our company have the unique advantages of...

Claims

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Application Information

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IPC IPC(8): C07C211/27C07C209/48C07C263/10C07C265/14
Inventor 李付国黎源赵文娟何光文华卫琦
Owner WANHUA CHEM GRP
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