KR20210025808A - Method for preparing dibutyl tetrahydrophthalate and dibutyl tetrahydrophthalate prepared by the same - Google Patents

Abstract

The present invention relates to a method for preparing dibutyl tetrahydrophthalate and to dibutyl tetrahydrophthalate prepared thereby. According to the preparation method in the present invention, dibutyl tetrahydrophthalate can be prepared in a fast process and in high yield.

Description

Method for producing dibutyl tetrahydrophthalate and dibutyl tetrahydrophthalate prepared therefrom TECHNICAL FIELD [METHOD FOR PREPARING DIBUTYL TETRAHYDROPHTHALATE AND DIBUTYL TETRAHYDROPHTHALATE PREPARED BY THE SAME}

The present invention relates to a method for preparing dibutyl tetrahydrophthalate and to dibutyl tetrahydrophthalate prepared therefrom.

Phthalate-based compounds are widely used as plasticizers for plastics, especially polyvinyl chloride (PVC). For example, electrical and electronic products, pharmaceuticals, paint pigments, lubricants, binders, surfactants, adhesives, tiles, food containers, packaging materials, etc., indeed, their uses are very diverse.

However, as some phthalate-based compounds are known as substances that can cause environmental pollution and human endocrine system disorders, efforts to reduce their use are being strengthened in advanced countries such as Europe and the United States. In particular, among phthalate compounds, di(2-ethylhexyl) phthalate (di(2-ethylhexyl) phthalate, DEHP)), butyl benzyl phthalate (BBP), and di-n-butyl phthalate Some products, such as, DBP), are socially suspicious of environmental hormones as an endocrine disrupter that interferes or disrupts human hormone function, and there is a movement to regulate it.

Accordingly, efforts are being made to develop eco-friendly phthalate-based compounds that exhibit the same performance as conventional phthalate-based compounds and are free from environmental hormone controversies.

Korean Patent Application Publication No. 2018-0077995

Accordingly, an object of the present invention is to provide a method of preparing dibutyl tetrahydrophthalate having excellent process efficiency and yield.

In addition, an object of the present invention is to provide a method of preparing dibutyl tetrahydrophthalate that can improve environmental pollution and toxicity problems.

In order to achieve the above object, an exemplary embodiment of the present invention includes a first step of preparing a mixture by mixing tetrahydrophthalic acid and butyl alcohol; A second step of refluxing the mixture; A third step of cooling the refluxed mixture; And a fourth step of deacidification of the cooled mixture with a basic aqueous solution.

In the first step of preparing a mixture by mixing tetrahydrophthalic acid and butyl alcohol, the content of butyl alcohol may be 2.1 mol to 2.3 mol with respect to 1 mol of tetrahydrophthalic acid.

The second step of refluxing the mixture may be performed at a temperature of 120°C to 150°C.

In the second step of refluxing the mixture, the acid value of the mixture may be 10 or less.

After the second step of refluxing the mixture and before the third step of cooling the refluxed mixture, a second step of adding butyl alcohol may be further included. In step 2-1 of adding the butyl alcohol, the acid value of the mixture may be 3 or less.

In the fourth step of deoxidizing the cooled mixture with a basic aqueous solution, the basic aqueous solution may include an aqueous sodium hydroxide solution.

After the fourth step of deoxidizing the cooled mixture with a basic aqueous solution, a 4-1 step of washing the deoxidized mixture with water may be additionally included.

It may further include a 4-2 step of vacuum recovery after the 4-1 step of washing the deoxidized mixture with water. Step 4-2 of vacuum recovery may be performed at a temperature of 150°C to 160°C.

Dibutyl tetrahydrophthalate according to an embodiment of the present invention may be prepared by the above-described method.

Dibutyl tetrahydrophthalate according to an exemplary embodiment of the present invention may improve environmental pollution and toxicity problems as a substitute for dibutyl phthalate.

In addition, by performing the step of refluxing a mixture of tetrahydrophthalic acid and butyl alcohol, the acid value in the first reaction can be reduced as much as possible. In addition, by lowering the acid value, it is possible to provide a high yield of dibutyl tetrahydrophthalate, the amount of deoxidation can be reduced to reduce the generation of waste, and the final product can be prevented from being lost in the deoxidation step and water washing step. It can have a yield.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, and only these embodiments make the disclosure of the present invention complete, and are common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used with meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically.

In the present specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

Hereinafter, the present invention will be described in detail.

An exemplary embodiment of the present invention, the first step of preparing a mixture by mixing tetrahydrophthalic acid (tetrahydrophthalic acid) and butyl alcohol (Butyl alcohol); A second step of refluxing the mixture; A third step of cooling the refluxed mixture; And a fourth step of deacidification of the cooled mixture with a basic aqueous solution.

The first step of preparing a mixture by mixing tetrahydrophthalic acid and butyl alcohol is a process for preparing a mixture by mixing raw materials of dibutyl tetrahydrophthalate, and tetrahydrophthalic acid is anhydrous. It may also contain tetrahydrophthalic anhydride. In an exemplary embodiment of the present invention, the butyl alcohol may be N-butyl alcohol.

In an exemplary embodiment of the present invention, in the first step of preparing a mixture by mixing the tetrahydrophthalic acid and butyl alcohol, the content of butyl alcohol is based on 1 mole of the tetrahydrophthalic acid. It is from 2.1 moles to 2.3 moles. In the case of the content range of the butyl alcohol, it is appropriate in terms of physical properties and yield of the prepared dibutyl tetrahydrophthalate.

The first step of preparing a mixture by mixing tetrahydrophthalic acid and butyl alcohol may be performed in an atmosphere consisting of at least one inert gas of nitrogen gas or hydrogen gas at normal pressure, and preferably It can be reacted by mixing tetrahydrophthalic acid and butyl alcohol under the introduction of nitrogen gas.

The mixture may further contain additives such as an acid catalyst and an anti-coloring agent, for example, para-toluenesulfonic acid monohydrate (p-TSA), hypophosphorous acid (H ₃ PO ₂ ), methane sulfonic acid, tea Sodium phosphate (NaH ₂ PO ₂ ·H ₂ O), and the like, but is not limited thereto. The content of the additive is preferably 0.1% to 0.5% of the total input amount.

In an exemplary embodiment of the present invention, the second step of refluxing the mixture is performed at a temperature of 120°C to 150°C. More specifically, the second step of refluxing the mixture is performed for 8 to 12 hours under nitrogen input at a temperature of 120°C to 150°C.

In the second step of refluxing the mixture according to an exemplary embodiment of the present invention, the acid value of the mixture is 10 or less. More specifically, in the second step of refluxing the mixture, the acid value of the mixture is 5 or less.

In an exemplary embodiment of the present invention, after the second step of refluxing the mixture, before the third step of cooling the refluxed mixture, a second step of adding butyl alcohol is further included. In one exemplary embodiment, in step 2-1 of adding the butyl alcohol, the acid value of the mixture is 3 or less. The butyl alcohol may be N-Butyl alcohol.

In an exemplary embodiment of the present invention, after the second step of refluxing the mixture, before the third step of cooling the refluxed mixture, the content of the butyl alcohol added in step 2-1 of adding butyl alcohol is It may be 0.2 to 0.5 moles per 1 mole of the tetrahydrophthalic acid.

A high acid value means that unreacted acid remains, which adversely affects the purity of the product itself. In the present invention, an increase in the acid value can be prevented through the second step of refluxing the mixture.

As described above, in an exemplary embodiment of the present invention, after lowering the acid value as much as possible in the second step of refluxing the mixture, butyl alcohol may be added in small portions, thereby making it have a lower acid value with an acid value of 3 or less. In this case, a high yield of dibutyl tetrahydrophthalate can be expected, and as the acid value is lower, the amount of deoxidation decreases to reduce waste generation, and the loss of the product in the steps of deoxidation and washing with water, which will be described later, can be minimized. .

In an exemplary embodiment of the present invention, the third step is a step of cooling the mixture refluxed in the second step, and may be performed when the acid value of the mixture in the second step or the step 2-1 is 3 or less. have. More specifically, the third step of cooling the refluxed mixture may be cooled to 70 ℃ to 80 ℃. In this case, soap and impurities generated during the deoxidation treatment can be quickly separated.

In an exemplary embodiment of the present invention, the fourth step of deacidification of the cooled mixture with a basic aqueous solution may further lower the acid value of the mixture. More specifically, the acid value may be lowered to 0 through the fourth step.

The basic aqueous solution may be an aqueous solution containing an alkali metal or an alkaline earth metal. Specifically, any one of potassium hydroxide, sodium hydroxide, calcium hydroxide, or lithium hydroxide may be used alone or in combination of two or more. Preferably, it may contain an aqueous sodium hydroxide solution. More specifically, the basic aqueous solution may contain 10% sodium hydroxide aqueous solution.

In the method for producing dibutyl tetrahydrophthalate according to an exemplary embodiment of the present invention, by including a second step of refluxing the mixture and/or a second step of adding butyl alcohol after the second step of refluxing the mixture. In the fourth step of deacidification of the cooled mixture with a basic aqueous solution, the mixture having a low acid value is deoxidized. In the case of deoxidation treatment of a mixture having a low acid value, the amount of basic aqueous solution used can be reduced, thereby reducing the generation of waste and greatly improving the yield.

In an exemplary embodiment of the present invention, after the fourth step of deoxidizing the cooled mixture with a basic aqueous solution, a step 4-1 of washing the deoxidized mixture with water may be additionally included.

In addition, the 4-1 step of washing with water may include a first washing step; And a second washing step. More specifically, in an exemplary embodiment of the present invention, washing water corresponding to 5% of the total mass is firstly added to the deoxidized mixture, stirred for 30 minutes to 1 hour, and left to stand. A first washing step of separating the portion and washing water; And a second washing step in which secondary washing water corresponding to 5% of the total mass is added to the first washed mixture, stirred for 30 minutes, and then allowed to stand to remove remaining impurities. The separated washing water may be removed 1 to 2 hours after the second washing water is added.

In an exemplary embodiment of the present invention, a 4-2 step of vacuum recovery after the 4-1 step of washing the deoxidized mixture with water is further included.

In an exemplary embodiment of the present invention, step 4-2 of vacuum recovery may be performed at a temperature of 150°C to 160°C. More specifically, step 4-2 of the constant vacuum recovery may remove moisture remaining after deoxidation and excess alcohol by vacuum decompression under an inert gas atmosphere such as nitrogen at a temperature of 150°C to 160°C.

In the method for producing dibutyl tetrahydrophthalate according to an exemplary embodiment of the present invention, including a second step of refluxing the mixture and/or a second step of adding the butyl alcohol, a mixture of low acid value is deoxidized The filtration time can be shortened because the amount of the basic aqueous solution used is small.

Dibutyl tetrahydrophthalate finally obtained after step 4-2 of vacuum recovery is quality controlled (Q.C), and if there is no abnormality, it may be cooled to 50° C. and filtered and packaged.

In an exemplary embodiment of the present invention, it is possible to provide dibutyl tetrahydrophthalate prepared by the above-described manufacturing method.

The following is an experiment conducted to demonstrate the excellence of the method for preparing dibutyl tetrahydrophthalate of the present invention.

Example

After 315 g of tetrahydrophthalic anhydride was added to a 1000 ml four-necked flask, 362.6 g of butyl alcohol, 1.65 g of p-TSA _{, and 1.03 g of hypophosphorous acid (H 3} PO ₂ ) were added, and a water measuring water dispenser was used. Then, the temperature was raised (70°C) and stirred. When the temperature reached 70° C., a small amount of nitrogen was added and the temperature was gradually raised (130° C.). At about 110 ℃, the reaction water and alcohol were vaporized and liquefied again through a reflux cooler. Alcohol and reaction water were recovered with a water quantifying water, and the recovered alcohol was put back into the reaction tank. After 10 to 12 hours of reaction time, the first reaction acid value was 3.5, and 20 g of butyl alcohol was newly added, followed by further reaction. The final acid value was 1.9, and neutralization was performed by cooling to 70°C. NaOH: 1.9 g was dissolved in water: 18 g with a 10% aqueous solution of sodium hydroxide (NaOH) and used. After neutralization, the acid value became 0 and washed with water. Washing water was washed by dividing 60 g in two. After stirring for 30 minutes, it was transferred to a separatory funnel, left to stand for 1 hour, and impurities at the bottom were separated. (Proceed twice) After washing with water was separated, vacuum recovery (150°C) was performed to remove all remaining moisture and alcohol. After completion of the reaction, the mixture was cooled (50° C.) and the synthetic product was filtered to terminate. 50.5 g of reaction water and 44.3 g of alcohol were recovered. The product yield was 84%, and the total yield including the recovered alcohol was 89.3%. 590g of the synthesized product was added and 700g was added.

Comparative example

After 315 g of tetrahydrophthalic anhydride was added to a 1000 ml four-necked flask, 362.6 g of butyl alcohol, 1.65 g of p-TSA _{, and 1.03 g of hypophosphorous acid (H 3} PO ₂ ) were added to 130 ℃. The temperature was raised (nitrogen injection). The reaction water and alcohol were vaporized at around 110° C., liquefied through a cooler, and recovered. After 14 hours of reaction time, the result of acid value measurement was 95, and most of butanol was recovered and was not lowered any more. 110 g of the recovered alcohol was reused and further reacted. The acid value measured after 4 hours was 46.3. 95 g of the recovered alcohol was added and reacted, and the acid value measured again after 2 hours was 36.45. After 2 hours of further reaction, the acid value became 26.1, but the reaction time became too long, resulting in a reverse reaction, and the acid value increased to 35 again, and the reaction was terminated without further proceeding due to the high acid value and long reaction time.

Comparing the above Examples and Comparative Examples, dibutyl tetrahydrophthalate according to an exemplary embodiment of the present invention has reduced reaction time and filtration time, so that dibutyl tetrahydrophthalate can be obtained in a high yield in a short time. Specifically, dibutyl tetrahydrophthalate according to an exemplary embodiment of the present invention can increase the reaction rate and yield by lowering the acid value as much as possible through the reflux reaction of butanol and then adding butanol in small portions to make an acid value of 3 or less. .

The scope of the present invention is not limited to the above-described embodiments, but may be implemented in various forms within the scope of the appended claims. Anyone having ordinary knowledge in the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims is considered to be within the scope of the description of the claims of the present invention to various ranges that can be modified.

Claims (11)

A first step of preparing a mixture by mixing tetrahydrophthalic acid and butyl alcohol;
A second step of refluxing the mixture;
A third step of cooling the refluxed mixture; And
A method for producing dibutyl tetrahydrophthalate comprising a fourth step of deacidification with a basic aqueous solution to the cooled mixture. The method of claim 1,
In the first step of preparing a mixture by mixing the tetrahydrophthalic acid and butyl alcohol (Butyl alcohol), the content of the butyl alcohol is 2.1 mol to 2.3 mol with respect to 1 mol of the tetrahydrophthalic acid. Method for producing tetrahydrophthalate. The method of claim 1,
The second step of refluxing the mixture is a method for producing dibutyl tetrahydrophthalate that is performed at a temperature of 120°C to 150°C. The method of claim 1,
In the second step of refluxing the mixture,
The method for producing dibutyl tetrahydrophthalate, wherein the mixture has an acid value of 10 or less. The method of claim 4,
After the second step of refluxing the mixture and before the third step of cooling the refluxed mixture,
The method for producing dibutyl tetrahydrophthalate further comprising the step 2-1 of adding butyl alcohol. The method of claim 5,
In the 2-1 step of adding the butyl alcohol,
The method for producing dibutyl tetrahydrophthalate, wherein the mixture has an acid value of 3 or less. The method of claim 1,
In the fourth step of deoxidizing the cooled mixture with a basic aqueous solution,
The method for producing dibutyl tetrahydrophthalate, wherein the basic aqueous solution includes an aqueous sodium hydroxide solution. The method of claim 1,
After the fourth step of deoxidizing the cooled mixture with a basic aqueous solution, the method for producing dibutyl tetrahydrophthalate further comprises a 4-1 step of washing the deoxidized mixture with water. The method of claim 8,
The method for producing dibutyl tetrahydrophthalate further comprises a 4-2 step of vacuum recovery after the 4-1 step of washing the deoxidized mixture with water. The method of claim 9,
Step 4-2 of the vacuum recovery is a method of producing dibutyl tetrahydrophthalate is performed at a temperature of 150 ℃ to 160 ℃. A method for producing dibutyl tetrahydrophthalate prepared by the method according to any one of claims 1 to 10.