Refining method of terephthalaldehyde

A technology of terephthalaldehyde and a purification method, applied in the field of polymer-grade terephthalaldehyde and the purification of terephthalaldehyde, can solve the problems of low yield, limitation, low yield of terephthalaldehyde, etc., and achieve the yield High, high product purity effect

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

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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 im...

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 -30KPa, 40°C. Then put the evaporated material in p-xylene at 70°C, the mass of p-xylene is 100g, fully stir and dissolve, then filter, cool to 20°C, terephthalaldehyde starts to crystallize during the cooling process, and then stand for 5h After the terephthalaldehyde crystallization is completed, filter to obtain a terephthalaldehyde product, and dry the filtered terephthalaldehyde product at 60° C. for 20 hours to obtain a refined terephthalaldehyde product. The total yield of refined terephthalaldehyde product is 92.2%, and the purity is 99.5%.

Embodiment 2

[0025] 10 g of crude terephthalaldehyde was placed in an evaporator and evaporated under normal pressure at 60°C. Then put the evaporated material in p-xylene at 90°C, the mass of p-xylene is 60g, fully stir and dissolve, then filter, cool to 40°C, terephthalaldehyde begins to crystallize during the cooling process, and then stand for 5h After the terephthalaldehyde crystallization is completed, filter to obtain a terephthalaldehyde product, and dry the filtered terephthalaldehyde product at 60° C. for 20 hours to obtain a refined terephthalaldehyde product. The total yield of refined terephthalaldehyde product is 94.5%, 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 put the evaporated material in p-xylene at 90°C, the mass of p-xylene is 80g, fully stir and dissolve, then filter, cool to 30°C, terephthalaldehyde starts to crystallize during the cooling process, and then stand for 5h After the terephthalaldehyde crystallization is completed, filter to obtain a terephthalaldehyde product, and dry the filtered terephthalaldehyde product at 60° C. for 20 hours to obtain a refined terephthalaldehyde product. The total yield of refined terephthalaldehyde product is 93.8%, and the purity is 99.5%.

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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 or normal pressure condition, and after impurities are removed, taking paraxylene as a solvent, and conducting dissolving, filtering, cooling crystallizing, filtering and drying to obtain a terephthalaldehyde refined product. The methodhas the advantages that only a reaction raw material paraxylene is used as the solvent, the technology process is environmentally friendly, impurities such as p-tolualdehyde are removed through evaporation, then the refined terephthalaldehyde product is obtained through paraxylene dissolution and crystallizing processes, the product purity is high, the yield is high, 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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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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