KR102014585B1 - Method for preparing aromatic dicarbonate - Google Patents

Abstract

A method for producing an aromatic diester carbonate according to the present invention comprises transesterification of an aliphatic carbonate diester and an aromatic alcohol in the presence of an organometallic catalyst to prepare a reaction mixture; Separating a carbonate reaction by-product containing an aromatic diester carbonate and an organometallic catalyst from the reaction mixture; Preparing a first reactant in which a byproduct is dissolved by mixing a polar solvent with the carbonate reaction byproduct containing the organometallic catalyst; Adding a nonpolar solvent to the first reactant to precipitate an organometallic catalyst; Recovering the precipitated organometallic catalyst and injecting it into the transesterification reaction; Steps.

Description

Aromatic Carbonic Acid Diester Production Method {METHOD FOR PREPARING AROMATIC DICARBONATE}

The present invention relates to a method for producing aromatic diester carbonate. More specifically, the present invention relates to a method for producing an aromatic diester which can recover the catalyst in a high yield from the by-products produced when producing the aromatic diester carbonate.

Aromatic carbonate diester compounds are prepared using toxic toxic, but toxic, toxic toxic, excessive alkali salts, there is a problem using an organic solvent. In order to solve the problems occurring in the process of producing an aromatic carbonate diester compound using phosgene, a method for producing an aromatic carbonate diester compound by reacting an aliphatic carbonate diester compound and an aromatic alcohol in the presence of an organometallic catalyst has been developed. The reaction between the aliphatic carbonate diester compound and the aromatic alcohol has a small equilibrium constant so that the productivity can be improved through a reaction distillation method of improving the forward reaction by removing alcohol as a byproduct under high temperature and high pressure conditions. However, by-products are produced because the high temperature reaction proceeds in the presence of the catalyst, and some of the waste products are discarded to suppress the increase in the reaction system. In this process, some catalysts are disposed of together. Since the disposal of the catalyst in the aromatic diester carbonate manufacturing process is not caused by deactivation, but by the removal of by-products, this is a loss of material cost. When the catalyst in the waste is recovered and reused, It can be prevented from being discarded as waste.

Since the by-products generated in the process has a high boiling point, it is not easy to separate from the catalyst by a simple distillation method. Even if the separation is possible, a large amount of energy is required at a high temperature, and the method is not suitable for synthesizing the aromatic carbonic acid diester through aliphatic carbonic acid diester and aromatic alcohol, which consumes a lot of energy.

Another method for preventing the loss of the catalyst is to apply a heterogeneous catalyst in which the catalyst is supported on a metal oxide. In this case, since the catalyst is bound to the metal oxide support, the amount of the by-products incorporated into the by-products is extremely low, so even if the by-products are disposed of, the content of the catalyst contained in the waste is extremely low, so that no separate separation process is required. In case of supporting the catalyst on the metal oxide, it can be applied through the new process or the improvement of the existing equipment, but it is less effective when applied in the operation process because it is more complicated and expensive compared to the construction of the catalyst recovery process. A problem arises.

Related prior arts are Japanese Patent Laid-Open No. 1997-169704.

An object of the present invention is to provide a method for producing an aromatic diester carbonate that can recover the catalyst from the reused by-products without discarding the by-products produced when producing the aromatic diester carbonate.

Another object of the present invention is to provide an aromatic diester carbonate production method which minimizes energy consumption by not using distillation when recovering a catalyst.

Still another object of the present invention is to provide an aromatic diester carbonate production method capable of recovering the catalyst used in the production of the aromatic diester carbonate in high yield.

The above and other objects of the present invention can be achieved by the present invention described below.

The present invention relates to a method for producing aromatic diester carbonate. The method comprises transesterifying aliphatic diester carbonate and an aromatic alcohol in the presence of an organometallic catalyst to prepare a reaction mixture; Separating a carbonate reaction by-product containing an aromatic diester carbonate and an organometallic catalyst from the reaction mixture; Preparing a first reactant in which a byproduct is dissolved by mixing a polar solvent with the carbonate reaction byproduct containing the organometallic catalyst; Adding a nonpolar solvent to the first reactant to precipitate an organometallic catalyst; Recovering the precipitated organometallic catalyst and injecting it into the transesterification reaction; Steps.

The polar solvent may include one or more of anisole, aliphatic alcohol, aromatic alcohol, ketone, aldehyde, glycol, carbonate.

The nonpolar solvent may include at least one of pentane, hexane, heptane, octane, decane, dodecane, cyclopentane, cyclohexane, and cyclooctane.

In one embodiment the polar solvent is anisole, the non-polar solvent may be hexane.

In another embodiment, the polar solvent may be acetone, and the nonpolar solvent may be cyclohexane.

In embodiments, the polar solvent may be 50 to 500 parts by weight based on 100 parts by weight of the carbonate reaction by-product.

In embodiments, the nonpolar solvent may be 50 to 200 parts by weight based on 100 parts by weight of the polar solvent.

In embodiments, the organometallic catalyst may include one or more of metals of Ti, Pb, Ce, Cu, Zn, Fe, Co, Ni, Al, V, Sm, Sn, and Zr.

The organometallic catalyst may be an unsupported homogeneous catalyst.

The present invention can recover the catalyst from the by-product without disposing the by-products produced when producing the aromatic diester carbon dioxide can be reused, the energy consumption can be minimized by using a distillation method when the catalyst is recovered, high yield as a catalyst It has the effect of providing an aromatic diester carbonate production method which can be recovered.

1 is a process chart showing an aromatic carbonate diester production method according to an embodiment of the present invention.

A method for producing an aromatic diester carbonate according to the present invention comprises transesterification of an aliphatic carbonate diester and an aromatic alcohol in the presence of an organometallic catalyst to prepare a reaction mixture; Separating a carbonate reaction by-product containing an aromatic diester carbonate and an organometallic catalyst from the reaction mixture; Preparing a first reactant in which a byproduct is dissolved by mixing a polar solvent with the carbonate reaction byproduct containing the organometallic catalyst; Adding a nonpolar solvent to the first reactant to precipitate an organometallic catalyst; Recovering the precipitated organometallic catalyst and injecting it into the transesterification reaction; Steps.

1 is a process chart showing an aromatic carbonate diester production method according to an embodiment of the present invention.

Referring to FIG. 1, aliphatic carbonic acid diester, aromatic alcohol, and the like, which are reaction raw materials, are introduced into a transesterification reactor R1 through a line L1. Although illustrated as one line L1 in the figure, each may be input through a separate line.

In the transesterification reactor (R1), an aliphatic diester and an aromatic alcohol are transesterified in the presence of an organometallic catalyst to prepare a reaction mixture.

The organometallic catalyst may be introduced via line (L1), after which the recovered catalyst is introduced via line (L5).

The aliphatic diester carbonate may be represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1, R ₁ is each independently a substituted or unsubstituted C1 to C10 alkyl group or C3 to C10 cycloalkyl group.

Specific examples of the aliphatic carbonic acid diesters include dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, dipentyl carbonate, dihexyl carbonate, diheptyl carbonate, dioctyl carbonate, dinonyl carbonate, didecyl carbonate, and dish Clopentylcarbonate, dicyclohexylcarbonate, dicycloheptylcarbonate, di (methoxymethyl) carbonate, di (methoxyethyl) carbonate, di (chloroethyl) carbonate, di (cyanoethyl) carbonate, and the like.

The aromatic alcohols include phenol, cresol, xenol, trimethylphenol, tetramethylphenol, ethylphenol, propylphenol, butylphenol, diethylphenol, methylethylphenol, methylpropylphenol, dipropylphenol, methylbutylphenol, and pentyl. Various alkylphenols such as phenol, hexylphenol, cyclohexylphenol, various alkoxyphenols such as methoxyphenol and ethoxyphenol, and arylalkylphenols such as phenyl propylphenol can be used.

The organometallic catalyst may include one or more of metals of Ti, Pb, Ce, Cu, Zn, Fe, Co, Ni, Al, V, Sm, Sn, and Zr. In an embodiment said organometallic catalyst is an unsupported homogeneous catalyst. Specifically, TiCl ₄ , Ti (OMe) ₄ , (MeO) Ti (OPh) ₃ , (MeO) ₂ Ti (OPh) ₂ , (MeO) ₃ Ti (OPh), Ti (OPh) ₄ , Ti (= O) (acac) ₂ , Pb (OPh) ₂ , FeCl ₃ , Fe (OH) ₃ , Fe (OPh) _{3 ,} SnCl ₄ , Sn (OPh) ₄ , Bu ₂ SnO, Bu ₂ Sn (OPh) ₂ , and the like. May be, but is not necessarily limited thereto.

The reaction mixture prepared by transesterification of the aliphatic diester and the aromatic alcohol is mixed with the aromatic diester and the by-product. The reaction mixture is discharged through line (L2), the aromatic diester carbonic acid product is discharged through line (L4), and by-products are recovered in the catalytic recovery reactor (R2) without being discarded through line (L3).

The by-products are organometallic catalysts, unreacted raw materials, aromatic alcohols, carbonate derivatives, carbonyl acids, esters, and the like as carbonate reaction by-products containing organometallic catalysts.

The first reactant is prepared by mixing and dissolving a polar solvent in a carbonate reaction by-product containing the organometallic catalyst. Since the carbonate reaction by-product containing the organometallic catalyst contains a metal catalyst which is a Lewis acid and an aliphatic carbonate, an aromatic carbonate, an aromatic alcohol, a carbonate derivative, carbonyl acid, an ester, and the like, polar substances such as anisole and aliphatic alcohol Excellent solubility in aromatic alcohols, ketones, aldehydes, glycols, carbonates and the like can be dissolved well without forming precipitates.

In embodiments, the polar solvent may be 50 to 500 parts by weight based on 100 parts by weight of the carbonate reaction by-product. While completely dissolving the metal catalyst and the high by-products in the composition, even when a small amount of nonpolar solvent is used, the metal catalyst forms a precipitate, and the by-products can be maintained in a liquid phase at room temperature to facilitate catalyst separation through filtering.

The polar solvent is soluble in both by-products and organometallic catalysts, and may include one or more of anisole, aliphatic alcohol, aromatic alcohol, ketone, aldehyde, glycol, and carbonate.

Thereafter, a nonpolar solvent is added to the first reactant to precipitate an organometallic catalyst. When a nonpolar solvent is added to the polar first reactant, only the polar metal catalyst forms a precipitate. Aliphatic carbonates, aromatic carbonates, aromatic alcohols, carbonate derivatives, carbonic acid, and esters, which are components of by-products, exist in the liquid phase at a temperature below room temperature to 100 ° C. Since it does not occur, only the metal catalyst to be recovered may selectively form a precipitate. While the nonpolar solvent is insoluble in organometallic catalysts, those having solubility in by-products can be used. For example, it may include one or more of pentane, hexane, heptane, octane, decane, dodecane, cyclopentane, cyclohexane, cyclooctane. In this way, the polarity of the solution is changed through the addition of a non-polar solvent, so that the remaining by-products can be separated into a liquid phase and the catalyst can be separated into a solid phase and recovered as a solid catalyst.

In one embodiment the polar solvent is anisole, the non-polar solvent may be hexane. The combination of such a polar solvent and a non-polar solvent has the advantage of excellent catalyst recovery and easy handling, and low cost.

In another embodiment, the polar solvent may be acetone, and the nonpolar solvent may be cyclohexane. The combination of such a polar solvent and a non-polar solvent has an advantage of excellent catalyst recovery.

In embodiments, the nonpolar solvent may be 50 to 200 parts by weight based on 100 parts by weight of the polar solvent. In the above range, only the metal catalyst selectively forms precipitates, and organic byproducts have a dissolving effect.

1 shows a catalytic recovery reactor (R2) as a single reactor, but is not limited thereto, and may be formed as a multistage reactor.

The organometallic catalyst is precipitated and precipitated due to the difference in solubility, and then the organometallic catalyst and residual by-products are separated by filtration. The organometallic catalyst thus separated is introduced into the transesterification reactor (R1) through the line (L5) to participate in the aromatic diester carbonate synthesis. The filtrate remaining after the filtration does not leave the metal oxide of the organometallic catalyst, the unreacted raw materials such as aliphatic carbonate diester, phenol, etc. are left in the filtrate. Therefore, these unreacted raw materials can be recovered and reused.

Hereinafter, the present invention will be described in more detail with reference to examples, but these examples are for illustrative purposes only and should not be construed as limiting the present invention.

Example

Example  1-6 and Comparative example  1: catalyst recovery process

Example  One

In a 50 mL flask, 5 g of a carbonate reaction by-product containing Ti (= O) (acac) ₂ and 5 g of anisole were mixed and dissolved at room temperature. After confirming that the carbonate reaction by-products were completely dissolved, 1 g of hexane was added to the solution, followed by stirring for 1 hour. After the stirring was completed, it was filtered using a syringe filter having a pore of 0.2μm.

Example  2

The same procedure as in Example 1 was conducted except that 3 g of hexane was added.

Example  3

The same procedure as in Example 1 was conducted except that 5 g of hexane was added.

Example  4

The same procedure as in Example 1 was carried out except that 7 g of hexane was added.

Example  5

The same procedure as in Example 1 was conducted except that 10 g of hexane was added.

Example  6

In a 50 mL flask, 5 g of a carbonate reaction by-product containing Ti (= O) (acac) ₂ and 5 g of acetone were mixed and then dissolved at room temperature. After confirming that the carbonate reaction by-products were completely dissolved, 5 g of cyclohexane was added to the solution, followed by stirring for 1 hour. After the stirring was completed, it was filtered using a syringe filter having a pore of 0.2μm.

Comparative example  One

The same procedure as in Example 1 was conducted except that no hexane was added.

In Examples 1 to 6 and Comparative Example 1, the catalyst concentrations were analyzed using ICP-MS, respectively, before and after the catalyst precipitation. The results are shown in Table 1 below.

Comparative example  2

In a 50 mL flask, 5 g of a carbonate reaction by-product containing Ti (= O) (acac) ₂ and 5 g of methylene chloride were mixed and then dissolved at room temperature. After confirming that the carbonate reaction by-products were completely dissolved, 5 g of toluene was added to the solution, followed by stirring for 1 hour. After the stirring was completed, it was filtered using a syringe filter having a pore of 0.2μm.

Example Comparative example One 2 3 4 5 6 One 2 Raw material
input By Product Input (g) 5.0 5.0 5.0 5.0 5.0 5.0 5.0 5.0 Anisole Dose (g) 5.0 5.0 5.0 5.0 5.0 - 5.0 - Acetone input (g) - - - - - 5.0 - - Hexane Input (g) 1.0 3.0 5.0 7.0 10.0 - - 5.0 Cyclohexane Input (g) 5.0 Methylene
Chloride
Input amount (g) - - - - - - - 5.0 toluene
Input amount (g) - - - - - - - 5.0 catalyst
density Before filtration (ppm) 3,455 2,923 2,533 2,235 1,900 2,533 3,800 2,533 After filtration (ppm) 3,094 2,108 1,576 1,214 764 1,601 3,649 2,508 Recovery rate (%) 10.44 27.88 37.79 45.69 59.79 36.79 3.97 1.00

As confirmed in Table 1, Example 1-6 it can be seen that the catalyst recovery is significantly higher than Comparative Example 1-2.

Example  7

12.29 g of phenol, 5.88 g of dimethyl carbonate (DMC), 20 ppm of the catalyst recovered in Example 1 were added to a 20 mL tubular SUS reactor, and then sealed. The sealed tube reactor was introduced into an oil bath whose temperature was maintained at 235 ° C. and shaken for 15 minutes. After removing the tube reactor and quenching the sample, 1g of sample was diluted with 10g of Acetone and 0.5g of internal standard solution, and the composition analysis and yield were calculated using GC (Agilent's 7890A Gas chromatography).

Example  8

The same process as in Example 7 was carried out except that 30 ppm of the catalyst recovered in Example 1 was added.

Example  9

The same process as in Example 7 was carried out except that 40 ppm of the catalyst recovered in Example 1 was added.

Control  One

The same process as in Example 7 was carried out except that 20 ppm of fresh Ti (= O) (acac) ₂ catalyst was added instead of the recovered catalyst.

Control  2

The same process as in Example 7 was carried out except that 30 ppm of a fresh Ti (= O) (acac) ₂ catalyst was added instead of the recovered catalyst.

Control  3

Fresh Ti (= O) (acac) ₂ catalyst not recovered catalyst Except for adding 40ppm it was carried out in the same manner as in Example 7.

Example 7 Example 8 Example 9 Comparative Example 1 Comparative Example 2 Comparative Example 3 Raw material
input Phenolic Dose (g) 12.29 12.29 12.29 12.29 12.29 12.29 DMC input (g) 5.88 5.88 5.88 5.88 5.88 5.88 catalyst
density Recovery catalyst
(ppm) 20 30 40 - - - Fresh catalyst
(ppm) - - - 20 30 40 Reaction temperature (℃) 235 235 235 235 235 235 Reaction time (min) 15 15 15 15 15 15 MPC yield (%) 4.15 6.56 7.94 4.27 6.39 7.90

As confirmed in Table 2, the aromatic carbonate diester production method of the present invention, even if the recovery catalyst is applied, the yield of the aromatic carbonate diester is similar or higher than that of Comparative Example 1-3 to which a fresh catalyst is applied. Can be.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be manufactured in various forms, and a person of ordinary skill in the art to which the present invention pertains has the technical spirit of the present invention. However, it will be understood that other specific forms may be practiced without changing the essential features. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

Claims (9)

An aliphatic carbonate and an aromatic alcohol are transesterified in the presence of an organometallic catalyst to prepare a reaction mixture;
Aromatic diester carbonate from the reaction mixture; Separating carbonate reaction byproducts containing organometallic catalysts;
Preparing a first reactant in which a byproduct is dissolved by mixing a polar solvent with the carbonate reaction byproduct containing the organometallic catalyst;
Adding a nonpolar solvent to the first reactant to precipitate an organometallic catalyst; And
Recovering the precipitated organometallic catalyst and injecting it into the transesterification reaction;
Aromatic carbonic acid diester manufacturing method comprising the step,
The polar solvent includes at least one of anisole, aliphatic alcohol, aromatic alcohol, ketone, aldehyde, glycol and carbonate,
The non-polar solvent is aromatic carbonate diester production method comprising at least one of pentane, hexane, heptane, octane, decane, dodecane, cyclopentane, cyclohexane and cyclooctane.
delete delete The method of claim 1, wherein the polar solvent is anisole, and the nonpolar solvent is hexane.
The method of claim 1, wherein the polar solvent is acetone, and the nonpolar solvent is cyclohexane.
The method of claim 1, wherein the polar solvent is 50 to 500 parts by weight based on 100 parts by weight of the carbonate reaction byproduct.
The method of claim 1, wherein the nonpolar solvent is 50 to 200 parts by weight based on 100 parts by weight of the polar solvent.
The method of claim 1, wherein the organometallic catalyst is characterized in that it comprises at least one of the metals of Ti, Pb, Ce, Cu, Zn, Fe, Co, Ni, Al, V, Sm, Sn, and Zr. Aromatic diester carbonate manufacturing method.
The method of claim 1, wherein the organometallic catalyst is an unsupported homogeneous catalyst.

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