Method for synthesizing trioxymethylene

A synthesis method and trioxymethylene technology, which are applied in chemical recycling, organic chemistry and other directions, can solve the problems of high cost of ionic liquid and low trioxymethylene yield, and achieve a good promotion effect, remarkable promotion effect and mild reaction conditions. Effect

Active Publication Date: 2013-10-30
CHINA NAT OFFSHORE OIL CORP +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

But the disadvantage is that the cost of ionic liquid is higher, and the yield of paraformaldehyde is lower compared with sulfuric acid method

Method used

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  • Method for synthesizing trioxymethylene
  • Method for synthesizing trioxymethylene
  • Method for synthesizing trioxymethylene

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] The synthesis of embodiment 1, paraformaldehyde

[0028] A rectification reaction device is adopted, wherein the rectification section is a glass packed tower with an inner diameter of 30mm and a height of 300mm, and the reaction kettle is a 250mL glass four-necked flask. Add 137.6g 60.0wt.% formaldehyde solution in the reactor, heat to boiling, then add successively the ionic liquid shown in 2.75g catalyst formula I-1 (being 2.0% of formaldehyde solution quality) and 1.38g accelerator LaCl 3 (1.0% of the quality of the formaldehyde aqueous solution); Heating total reflux reaction, the temperature at the bottom of the reactor is controlled at 95 ° C, the temperature at the top of the tower is 90 ° C, and the reaction is 90 minutes. The reaction solution in the reactor is taken, and the content of each component is analyzed by chromatography.

[0029] The content of paraformaldehyde in the reaction solution was 2.51wt.%, the content of methanol was 0.39wt.%, and impuriti...

Embodiment 2

[0030] The synthesis of embodiment 2, paraformaldehyde

[0031] With embodiment 1, get the formaldehyde aqueous solution of 137.2g 59.7wt.%, add ionic liquid shown in 2.6g catalyst formula I-2 (being 1.90% of formaldehyde aqueous solution quality), 1.37g promotor LaCl 3 (1.0% of the mass of the formaldehyde aqueous solution); wherein the temperature at the bottom of the reaction tank was controlled at 102° C., the temperature at the top of the tower was 95° C., and the reaction was performed for 3 hours.

[0032] According to chromatographic analysis, the content of paraformaldehyde in the reaction kettle liquid was 2.72wt.%, and the content of methanol was 0.62wt.%, and impurities such as methylal and methyl formate were not detected. In contrast, under the same reaction conditions, 60.0wt.% concentrated formaldehyde was used to add 2.0wt.% of the ionic liquid shown in the catalyst formula I-2, but no accelerator LaCl was added 3 , the content of paraformaldehyde in the reac...

Embodiment 3

[0033] The synthesis of embodiment 3, paraformaldehyde

[0034] With embodiment 1, get the formaldehyde aqueous solution of 133.7g 60.0wt.%, add the ionic liquid shown in 2.6g catalyst formula I-3 (being 1.94% of formaldehyde aqueous solution quality), 1.32g accelerator CuCl 2 (1.0% of the mass of the formaldehyde aqueous solution), wherein the temperature at the bottom of the reaction tank was controlled at 98° C., the temperature at the top of the tower was 92° C., and the reaction was performed for 3 hours.

[0035] According to chromatographic analysis, the content of paraformaldehyde in the reaction kettle liquid was 2.69wt.%, and the content of methanol was 0.52wt.%, and impurities such as methylal and methyl formate were not detected. In contrast, under the same reaction conditions, 60.0wt.% concentrated formaldehyde was used to add 2.0wt.% catalyst ionic liquid shown in formula I-3, but no accelerator CuCl was added 2 , the content of paraformaldehyde in the reaction ...

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Abstract

The invention discloses a method for synthesizing trioxymethylene. The method comprises the following step of carrying out a reaction on the aqueous solution of formaldehyde under the presence of an ionic liquid and an accelerant, wherein the accelerant is a salt compound, and the mass percent of the aqueous solution of formaldehyde is 30-70%. The method disclosed by the invention has the advantages that (1) the accelerant is convenient to prepare and has a good acceleration effect; (2) the activity of the ionic liquid which serves as a catalyst can be improved significantly without affecting the selectivity of the product of reaction, and the use amount and the cost of the ionic liquid can be reduced under the condition that the catalytic performance is guaranteed; (3) the concentration of the formaldehyde which serves as a raw material is wide and ranges between 30wt.% and 70wt.%, and the reaction condition is mild; (4) the continuous distillation reaction is adopted, and the accelerant can be recycled; (5) the concentration of the product of reaction is wide, and the accelerant has low corrosivity and a significant accelerating effect and can be recycled.

Description

technical field [0001] The invention relates to a method for synthesizing paraformaldehyde. Background technique [0002] As an important chemical product, paraformaldehyde has been widely used in the preparation of anhydrous formaldehyde, insecticides, molding materials, adhesives, disinfectants, antibacterials and other products. In particular, paraoxymethylene is an important raw material for the production of polyoxymethylene resin, and the growth of the national economy has an increasing demand for polyoxymethylene resin. [0003] Existing industrial technology (such as sulfuric acid synthesis of paraformaldehyde technology) has the disadvantages of strong corrosion, high equipment investment, and many by-products. However, the potential technology based on solid acid catalyst has disadvantages such as harsh operating conditions, long reaction time, and a large amount of solid waste by-product. With the increasingly stringent environmental protection regulations at ho...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D323/06
CPCY02P20/582
Inventor 胡玉峰陈步宁操斌白振敏王洪波金传伟张金柱王智鑫
Owner CHINA NAT OFFSHORE OIL CORP
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