4,4'-diamido diphenylmethane direct preparation method

A direct technology of diaminodiphenylmethane, applied in the field of catalytic synthesis technology of diaminodiphenylmethane, can solve the problems of complicated separation and purification process, strong acid corrosion, low product selectivity and the like

Inactive Publication Date: 2007-08-01
ZHEJIANG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] In the existing 4,4'-diaminodiphenylmethane synthesis technology, there are problems such as low product selectivity, corrosion by strong acid, complicated separation and purification pr

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] Example 1. Add 70.80 mmoles of freshly steamed aniline to a 25 ml three-necked flask equipped with reflux condenser and water separator, and stir to raise the temperature to 50° C. while being protected by nitrogen. Then add 23.54 mmoles of formaldehyde solution, and the rate of addition is controlled at 1 ml / min. Then add 1 gram of molecular sieve catalyst that has been pre-calcined at 550°C for 3 hours and placed in a desiccator for standby use. The reaction temperature was raised to 150° C., and the reaction time was 60 minutes.

[0022] The reaction product and the catalyst are centrifuged, and the catalyst can be recycled for reuse. The reaction liquid is subjected to vacuum rectification, and the unreacted aniline can be recovered and reused; the solid product after rectification is dissolved with ethanol, and the rectification under reduced pressure is repeated twice to obtain 4.40 grams of solid product. The product obtained through chromatography, mass spectr...

Embodiment 2

[0023] Example 2, according to the same reaction conditions as in Example 1 (150°C, 60 minutes), raw material composition (70.80 mmoles of aniline, 23.54 mmoles of formaldehyde) and separation steps, the catalysts were successively selected from H-X molecular sieves, USY molecular sieves, and H-beta molecular sieves , H-ZSM-5 molecular sieve, MCM-22 and MCM-41, the yield of the product diaminodiphenylmethane obtained and the selectivity of each isomer are as shown in table 1:

[0024] Table 1. Yield and selectivity of each isomer of direct synthesis of diaminodiphenylmethane from aniline and formaldehyde under the action of different catalysts

[0025]

Embodiment 3

[0026] Example 3, according to the same reaction conditions (150°C, 60 minutes) and raw material composition (70.80 mmoles of aniline, 23.54 mmoles of formaldehyde) as in Example 1, USY molecular sieves of different qualities were used as catalysts, and 0.4 grams and 0.6 grams were investigated in turn. , 0.8 gram, 10 gram, the yield and the isomer selectivity of diaminodiphenylmethane under the catalyst action of 1.2 gram metering, the obtained results are shown in Table 2:

[0027] Table 2. Yield and isomer selectivity of direct synthesis of diaminodiphenylmethane from aniline and formaldehyde under the action of different quality USY molecular sieve catalysts

[0028]

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PUM

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Abstract

The invention discloses a catalytic synthesizing technique of 4, 4'-diamino diphenylmethane, which comprises the following steps: adopting phenylamine and formaldehyde as raw material to do one-step condensed reaction intervally acted by solid acid catalyst; setting the molar rate of phenylamine and formaldehyde at 10/1-2/1 under 100-200 deg.c for 1-8h; circulating diamino diphenylmethane; recycling USY to synthesize the product with high activity.

Description

technical field [0001] The invention relates to a green, environment-friendly, clean and efficient catalytic synthesis process of diaminodiphenylmethane. Background technique [0002] Diaminodiphenylmethane (molecular formula: NH 2 C 6 h 4 CH 2 C 6 h 4 NH 2 , Molecular weight: 198.27, white or light yellow solid at room temperature, melting point 92-93°C, boiling point 398-399°C, soluble in ethanol, ether, benzene, etc., slightly soluble in water), easily oxidized in air, exposed to light There is blackening phenomenon. It is a dye and an intermediate in organic synthesis. Used in the production of MDI, corrosion inhibitor, epoxy resin curing agent, polyamide, etc., as a curing agent for epoxy resin, its function is similar to that of m-phenylenediamine. Suitable for castings, laminates, adhesives and coatings. The general dosage is 27-30 parts, curing conditions: 120°C / 3 hours, 150°C / 2 hours. The cured product has excellent electrical properties, chemical resista...

Claims

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Application Information

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IPC IPC(8): C07C209/24C07C211/50
Inventor 金顶峰侯昭胤郑小明
Owner ZHEJIANG UNIV
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