Refining method of terephthalaldehyde

A technology of terephthalaldehyde and purification method, applied in the field of terephthalaldehyde purification and polymerization grade terephthalaldehyde, can solve the problems of limitation, low yield, low terephthalaldehyde yield and the like, and achieve product purity The effect of high, high yield and simple process

Pending Publication Date: 2019-06-14
SINOPEC YANGZI PETROCHEM +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But this method is also limited in obtaining high-purity terephthalaldehyde
[0005] Chinese patent CN200580028008.8 discloses a method for preparing high-purity terephthalaldehyde from terephthalaldehyde crystals containing impurities by recrystallization using alcohol as solvent and water as anti-solvent, but the yield of terephthalaldehyde is low , the highest can only reach 79.2%
[0006] Chinese patent CN200780024375.X discloses a method for preparing high-purity terephthalaldehyde from terephthalaldehyde crystals containing impurities by using dimethyl sulfoxide as a solvent and water as an antisolvent through recrystallization, but terephthalaldehyde produces The rate is low, the highest can only reach 87%
[0007] Chinese patent CN200780041280.9 discloses a method of dissolving crude terephthalaldehyde in p-xylene, using dimethyl sulfoxide, etc. as a cosolvent, and then preparing high-purity terephthalaldehyde by recrystallization, but it obtains 99 When more than % purity terephthalaldehyde, productive rate is lower, and the highest can only reach 78.7%

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Put 10 g of crude terephthalaldehyde in an evaporator, and evaporate at -70KPa, 40°C. Then place the evaporated material in hot water at 70°C, the quality of the hot water is 20 times the mass of the terephthalaldehyde material, fully stir and dissolve, then filter, cool to 20°C, and terephthalaldehyde begins to crystallize during the cooling process , and then after standing for 5 hours, after the terephthalaldehyde crystallization is completed, filter to obtain the terephthalaldehyde product, and dry the filtered terephthalaldehyde product at 60°C for 20 hours to obtain the refined terephthalaldehyde product . The total yield of the refined terephthalaldehyde product is 92.6%, and the purity is 99.6%.

Embodiment 2

[0025] Put 10 g of crude terephthalaldehyde in an evaporator, and evaporate it at -90KPa, 20°C. Then place the evaporated material in hot water at 50°C, the quality of the hot water is 30 times the mass of the terephthalaldehyde material, fully stir and dissolve, then filter, cool to 20°C, and terephthalaldehyde begins to crystallize during the cooling process , and then after standing for 5 hours, after the terephthalaldehyde crystallization is completed, filter to obtain the terephthalaldehyde product, and dry the filtered terephthalaldehyde product at 60°C for 20 hours to obtain the refined terephthalaldehyde product . The total yield of the refined terephthalaldehyde product is 91.3%, and the purity is 99.4%.

Embodiment 3

[0027] Put 10 g of crude terephthalaldehyde in an evaporator, and evaporate at -30KPa, 50°C. Then place the evaporated material in hot water at 90°C, the quality of the hot water is 10 times the mass of the terephthalaldehyde material, fully stir and dissolve, then filter, cool to 40°C, and terephthalaldehyde begins to crystallize during the cooling process , and then after standing for 5 hours, after the terephthalaldehyde crystallization is completed, filter to obtain the terephthalaldehyde product, and dry the filtered terephthalaldehyde product at 60°C for 20 hours to obtain the refined terephthalaldehyde product . The total yield of the refined terephthalaldehyde product is 93.4%, and the purity is 99.7%.

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PUM

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Abstract

The invention discloses a refining method of terephthalaldehyde, which comprises the following steps: evaporating a terephthalaldehyde crude product under a vacuum condition, removing impurities, andwith water as a solvent, sequentially conducting dissolving, filtering, crystallizing, filtering and drying to obtain a terephthalaldehyde refined product. The method has the advantages that no solvent is used; the technological process is environmentally friendly, impurities such as p-tolualdehyde are removed through vacuum evaporation, then the refined terephthalaldehyde product is obtained through dissolving and crystallizing processes with water as a solvent, the method has the characteristics of high purity and high yield, the product purity reaches 99% or above, and the yield reaches 90%or above.

Description

technical field [0001] The invention belongs to the field of organic chemistry, in particular to a method for refining terephthalaldehyde, in particular to a method for refining crude terephthalaldehyde into polymer grade terephthalaldehyde. Background technique [0002] Terephthalaldehyde is an important intermediate in organic synthesis and polymer synthesis. Because it has two active aldehyde groups, it can not only self-polymerize, but also copolymerize with other units to form compounds with various properties. Terephthalaldehyde It is mainly used in industries such as plastics, spices, medicine, dyes, and fluorescent whitening agents. It is an important raw material for fine chemicals. There are many synthetic routes for terephthalaldehyde, such as chlorination and hydrolysis of p-xylene, gas-phase air oxidation of p-xylene, etc. Due to the complexity of the reaction, the obtained crude terephthalaldehyde contains more impurities, and needs to be further refined into p...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C45/78C07C47/544
Inventor 汪洋胡维强王英武刘经伟李泽壮
Owner SINOPEC YANGZI PETROCHEM
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