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Method for producing naphthalenedicarboxylic acid

A manufacturing method, a technology of naphthalene dicarboxylic acid, applied in 2 fields, can solve the problems that 2,6-naphthalene dicarboxylic acid cannot have the purity of polyethylene phthalate, etc., so as to improve the purity, increase the yield, reduce the The effect of using

Active Publication Date: 2007-11-28
HYOSUNG CHEM CORP
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, according to the proposed method, although relatively high-purity naphthalene dicarboxylic acid can be obtained, the purity of the obtained solid content is at most 98.5% by weight, and an additional purification process is required for use in polymerization.
[0005] The 2,6-naphthalene dicarboxylic acid produced by the conventional technology or the known invention cannot have the purity that can be directly used in the polymerization process of polyethylene phthalate

Method used

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  • Method for producing naphthalenedicarboxylic acid
  • Method for producing naphthalenedicarboxylic acid

Examples

Experimental program
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Effect test

Embodiment 1

[0052] The reactant was fed together with the catalyst into a titanium reactor with a capacity of 300 L having a condenser, a heater and a stirrer to carry out an oxidation reaction. In addition, the temperature of the oxidation reactor was adjusted to 200°C, and the pressure was adjusted to 20kg / cm 2 , rotate the stirrer at 700 rpm to disperse the reaction gas. During the reaction, add air in an amount of about 35.7 moles per 1 mole of 2,6-dimethylnaphthalene before the initial amount of recirculated gas is ensured; Naphthalene plus air was added in an amount of 22 moles. In addition, 1.8 mol of nitrogen was added as a diluent gas, and after stabilization, the circulation rate of the exhaust gas was adjusted so that the oxygen content of the exhaust gas was 4% to 6% by weight. After the crystallization step and the solid-liquid separation step after the oxidation reaction, the final product is obtained, and the final product is subjected to BSTFA displacement treatment unde...

Embodiment 2 and Embodiment 3

[0055] Production was carried out under the same conditions as in Example 1, except that the amount of acetic acid, the catalyst, and the circulation of the mother liquor were different from Example 1, thereby producing 2,6-naphthalene dicarboxylic acid. The compounds used in the reaction and the results are shown in Table 1 and Table 2, respectively.

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Abstract

A method for producing naphthalenedicarboxylic acid comprising the steps of: dissolving 2,6-dimethylnaphthalene in acetic acid solvent; oxidizing the product from the dissolution process using oxygen and a diluent gas; crystallizing naphthalenedicarboxylic acid that has been produced from the oxidation process; and separating the crystallized naphthalenedicarboxylic acid, wherein the amount of the diluent gas being discharged from and recycled to the oxidation process is controlled during the oxidation process, and the amount of mother liquor being recycled to the dissolution process after crystallization is controlled during the separation process, is provided.

Description

technical field [0001] The present invention relates to a method for producing naphthalene dicarboxylic acid (or "2,6-naphthalene dicarboxylic acid"), and in particular, to a method for producing 2,6-naphthalene dicarboxylic acid capable of improving purity and yield, wherein oxidized A portion of the product of the reaction is recycled to the process, reducing the use of reactants. Background technique [0002] Polyethylene phthalate is produced by a process including the steps of: oxidizing 2,6-dimethylnaphthalene with molecular oxygen to produce naphthalene dicarboxylic acid; esterifying naphthalene dicarboxylate to produce naphthalene dicarboxylate an acid ester and refining; and a step of polymerizing the refined naphthalene dicarboxylate with ethylene glycol. In such a production process, cobalt, manganese and bromine catalysts are required in the process of oxidizing 2,6-dimethylnaphthalene. [0003] The reason why naphthalene dicarboxylic acid cannot be directly us...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C63/38C07C51/265
CPCC07C51/265Y02P20/582C07C63/38C07C51/43C07C67/52
Inventor 千亮镐崔英教权益铉
Owner HYOSUNG CHEM CORP
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