JP2004123600A - Method for removing impurity in dihydroxybenzene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve effect on removal of impurities in dihydroxybenzene. <P>SOLUTION: The subject method for removing the impurities in the dihydroxybenzene comprises a first process for distilling crude dihydroxybenzene to obtain an acetone-containing fraction from a low-boiling side and a dihydroxybenzene-containing fraction from a high-boiling side, a second process for distilling the dihydroxybenzene-containing fraction to obtain the dihydroxybenzene-containing fraction from a low-boiling side and a heavy component-containing fraction from a high-boiling side, a third process for adding water to the dihydroxybenzene-containing fraction, bringing an extraction solvent into contact with the fraction and separating the fraction into a dihydroxybenzene-containing water layer and an impurity-containing oil layer, and a fourth process for distilling the dihydroxybenzene-containing water layer to obtain the dihydroxybenzene-containing fraction and a water-containing fraction. <P>COPYRIGHT: (C)2004,JPO

Description

【００１４】
【発明の効果】
本発明により、ジイソプロピルベンゼンを酸化する工程とジ（２−ジヒドロペルオキシ−２−プロピル）ベンゼンを分解する工程を含むプロセスから得られた粗ジヒドロキシベンゼンの精製方法であって、抽出操作の際に不純物除去のために添加物を用いることにより、不純物の少ない精製されたジヒドロキシベンゼンを得ることができるという優れた特徴を有するジヒドロキシベンゼンの精製方法を提供することができた。
【図面の簡単な説明】
【図１】本発明における不純物除去方法の流れの一例を示す図である。
【符号の説明】
１　第一工程
２　第二工程
３　第三工程
４　第四工程
５　抽出溶剤回収工程
６　粗ジヒドロキシベンゼン
７　精製ジヒドロキシベンゼン
８　アセトンを含む区分
９　ジヒドロキシベンゼンを含む区分
１０　重質分を含む区分
１１　ジヒドロキシベンゼンを含む区分
１２　水を含む区分
１３　抽出溶剤
１４　ジヒドロキシベンゼンを含む水層
１５　イソプロペニルフェノールを含む油層（抽出溶剤層）
１６　ジヒドロキシベンゼンを含む区分
１７　イソプロペニルフェノールを含む区分[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for purifying crude dihydroxybenzene obtained from a process comprising a step of oxidizing diisopropylbenzene and a step of decomposing di (2-dihydroperoxy-2-propyl) benzene, wherein purified dihydroxybenzene having a small amount of impurities is provided. The present invention relates to a method for removing impurities in dihydroxybenzene, which has an excellent feature that it can obtain
[0002]
[Prior art]
A method for obtaining purified dihydroxybenzene from crude dihydroxybenzene obtained from a process including a step of oxidizing diisopropylbenzene and a step of decomposing di (2-dihydroperoxy-2-propyl) benzene is described, for example, in an extraction operation. (See Patent Document 1), which provides excellent effects without using additives for improving liquid separation, and monovalent is contained in the deacetone bottom obtained by distilling acetone. A method of performing an extraction operation using an additive for improving liquid separation such as phenols (see Patent Document 2) is disclosed. However, trace amounts of impurities in dihydroxybenzene include isopropenylphenol and oxyacetophenone, but isopropenylphenol is a problem mainly as a trace impurity remaining in the final product. There has been a problem that impurities may not always be sufficiently removed.
[0003]
[Patent Document 1]
Japanese Patent Application No. 2001-173726 (Pages 2 to 3)
[Patent Document 2]
JP-A-64-38 (pages 1 to 4)
[0004]
[Problems to be solved by the invention]
In such circumstances, the problem to be solved by the present invention is to provide a method for purifying crude dihydroxybenzene obtained from a process comprising a step of oxidizing diisopropylbenzene and a step of decomposing di (2-dihydroperoxy-2-propyl) benzene. And a method for removing impurities in dihydroxybenzene, which has an excellent feature that purified dihydroxybenzene with less impurities can be obtained by using an additive for removing impurities during the extraction operation. On the point.
[0005]
[Means for Solving the Problems]
That is, the present invention relates to a method for purifying crude dihydroxybenzene obtained from a process comprising a step of oxidizing diisopropylbenzene and a step of decomposing di (2-dihydroperoxy-2-propyl) benzene, comprising: The method includes the third step from the step, and the effect of removing impurities in dihydroxybenzene is improved by adding the third component to the extraction solvent used in the extraction operation of the third step. It relates to a method for removing impurities.
First step: a step of subjecting crude dihydroxybenzene to distillation to obtain a fraction containing acetone from the low boiling side and to obtain a fraction containing dihydroxybenzene from the high boiling side;
Second step: a step of subjecting the section containing dihydroxybenzene obtained in the first step to distillation to obtain a section containing dihydroxybenzene from the low boiling side and obtaining a section containing heavy components from the high boiling side;
Third step: a step of adding water to the section containing dihydroxybenzene obtained in the second step, and then contacting it with an extraction solvent and subjecting it to extraction to separate into an aqueous layer containing dihydroxybenzene and an oil layer containing impurities;
Fourth step: a step of subjecting the aqueous layer containing dihydroxybenzene obtained in the third step to distillation to obtain a section containing dihydroxybenzene and a section containing water;
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
The raw material used in the present invention is crude dihydroxybenzene obtained from a process including a step of oxidizing diisopropylbenzene and a step of decomposing di (2-dihydroperoxy-2-propyl) benzene. The main components of the crude dihydroxybenzene are usually 2 to 40% by weight of acetone, usually 0.01 to 5% by weight of isopropenylphenol, and usually 2 to 40% by weight of dihydroxybenzene. % By weight, and the other component is methyl isobutyl ketone.
[0007]
Hereinafter, the impurity removing method of the present invention will be described in detail with reference to FIG.
[0008]
The first step 1 of the present invention is a step of subjecting the above crude dihydroxybenzene 6 to distillation to obtain a section 8 containing acetone from the low boiling side and a section 9 containing dihydroxybenzene from the high boiling side. The following can be exemplified as the conditions and the specific method of the first step. The distillation can be usually performed using a rectification column under the conditions of -95 to 1000 KpaG. A composition containing 2-80% by weight of acetone on the low boiling side, 0.1-20% by weight of isopropenylphenol, 1-30% by weight of heavy components and 70-99% by weight of dihydroxybenzene on the high boiling side. Can be.
[0009]
In the second step 2 of the present invention, the section 9 containing dihydroxybenzene obtained in the first step is subjected to distillation to obtain a section 11 containing dihydroxybenzene from the low boiling side and a section containing heavy components from the high boiling side. This is the step of obtaining No. 10. The following can be exemplified as the conditions and the specific method of the second step. The distillation can be usually performed using a simple distillation or a rectification column under the conditions of -100 to 0 KpaG. A fraction containing 0.1 to 20% by weight of isopropenylphenol and 80 to 99.9% by weight of dihydroxybenzene on the low boiling side and heavy components on the high boiling side can be obtained.
[0010]
In the third step 3 of the present invention, the section 11 containing dihydroxybenzene obtained by removing the section containing heavy components in the second step is divided into the section 12 containing water recycled from the fourth step and the section containing dihydroxybenzene. After adding 16, it is a step of contacting with an extraction solvent 13 for extraction to separate into an aqueous layer 14 containing dihydroxybenzene and an oil layer 15 containing isopropenylphenol as an impurity. The following can be exemplified as conditions and specific methods of the third step. The extraction can be usually carried out by countercurrent extraction using an extraction column and / or a mixer settler. Water is added to the section containing isopropenylphenol and dihydroxybenzene from which the heavy components obtained in the second step have been removed, and the concentration of dihydroxybenzene is adjusted to 5 to 70% by weight. It can be extracted on the oil side and separated into an aqueous layer containing dihydroxybenzene and an oil layer containing 0.05 to 20% by weight of isopropenylphenol. As the extraction solvent, toluene, xylene, cymene, triisopropylbenzene, diisopropylbenzene and the like can be used, but toluene is preferably used from the viewpoint of extraction efficiency and liquid separation. By adding the third component to the toluene, the impurity extraction efficiency can be further improved. Ketones are used as the third component, and among them, methyl isobutyl ketone is preferably used. The third component is added at least 2 wt% in toluene.
[0011]
In the fourth step 4 of the present invention, the aqueous layer 14 containing dihydroxybenzene obtained in the third step is subjected to distillation to obtain a purified dihydroxybenzene 7, and a section 16 containing dihydroxybenzene and impurities and a section 12 mainly containing water This is the step of obtaining The following can be exemplified as the conditions and specific method of the fourth step. The distillation can be usually performed using a rectification column under the conditions of -99 to 1000 KpaG. First, after distilling and removing a section mainly containing water, purified dihydroxybenzene is distilled to obtain a section containing dihydroxybenzene and impurities. Further, dihydroxybenzene containing a low-boiling component and a high-boiling component generated in this step can be recycled to the preceding step.
[0012]
【Example】
The present invention will be described more specifically based on examples, but the present invention is not limited to these examples.
Examples 1, 2, 3; Comparative Example 1
2.3 parts by weight containing 1.5% by weight of m-isopropenylphenol (hereinafter abbreviated as OST) obtained in the second step and 98% by weight of resorcinol, and a section mainly containing resorcinol partially recycled from the fourth step Water was added to 0.2 parts by weight to prepare a resorcinol aqueous solution having a resorcinol concentration of 50% by weight. With respect to 5 parts by weight of this resorcinol aqueous solution, 2.4 wt% (Example 1), 5 wt% (Example 2), and 8 wt% (Example 1) of methyl isobutyl ketone (hereinafter abbreviated as MIBK) as a third component in toluene Using 3 parts by weight of the extraction solvent to which 3) was added and 3 parts by weight of toluene to which MIBK was not added (Comparative Example 1), countercurrent liquid extraction was performed by an apparatus combining an extraction column and a mixer settler.
The OST removal rate was determined as follows.
OST removal rate = (OST amount before extraction−OST amount after extraction) / OST amount before extraction Experimental results are shown in Table 1.
[0013]
[Table 1]

[0014]
【The invention's effect】
According to the present invention, there is provided a method for purifying crude dihydroxybenzene obtained from a process comprising a step of oxidizing diisopropylbenzene and a step of decomposing di (2-dihydroperoxy-2-propyl) benzene. By using an additive for removal, it was possible to provide a method for purifying dihydroxybenzene having an excellent feature that purified dihydroxybenzene having few impurities can be obtained.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a flow of an impurity removing method according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st process 2 2nd process 3 3rd process 4 4th process 5 Extraction solvent collection process 6 Crude dihydroxybenzene 7 Purified dihydroxybenzene 8 Category 9 containing acetone Category 10 containing dihydroxybenzene Category 11 containing heavy matter 11 Dihydroxybenzene Category 12 containing water Category 13 containing water Extraction solvent 14 Water layer containing dihydroxybenzene 15 Oil layer containing isopropenylphenol (extraction solvent layer)
16 Category containing dihydroxybenzene 17 Category containing isopropenylphenol

Claims (5)

A method for purifying crude dihydroxybenzene obtained from a process comprising a step of oxidizing diisopropylbenzene and a step of decomposing di (2-dihydroperoxy-2-propyl) benzene, comprising the following first to third steps: A method for removing impurities in dihydroxybenzene, wherein the third component is added to an extraction solvent used in the extraction operation of the third step, thereby improving the effect of removing impurities in dihydroxybenzene.
First step: a step of subjecting crude dihydroxybenzene to distillation to obtain a fraction containing acetone from the low boiling side and to obtain a fraction containing dihydroxybenzene from the high boiling side;
Second step: a step of subjecting the section containing dihydroxybenzene obtained in the first step to distillation to obtain a section containing dihydroxybenzene from the low boiling side and obtaining a section containing heavy components from the high boiling side;
Third step: a step of adding water to the section containing dihydroxybenzene obtained in the second step, and then contacting it with an extraction solvent and subjecting it to extraction to separate into an aqueous layer containing dihydroxybenzene and an oil layer containing impurities;
Fourth step: a step of subjecting the aqueous layer containing dihydroxybenzene obtained in the third step to distillation to obtain a section containing dihydroxybenzene and a section containing water; The method for removing impurities in dihydroxybenzene according to claim 1, wherein the extraction solvent in the third step is toluene, and the third component to be added is a ketone. 3. The method for removing impurities in dihydroxybenzene according to claim 2, wherein the ketone as the third component is methyl isobutyl ketone. 4. The method for removing impurities in dihydroxybenzene according to claim 1, wherein the diisopropylbenzene is m-diisopropylbenzene, and the dihydroxybenzene is resorcin. 5. The method for removing impurities from dihydroxybenzene according to claim 1, wherein the crude dihydroxybenzene is crude resorcinol containing acetone, isopropenylphenol, methyl isobutyl ketone and heavy components.

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