JP2631803C - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION       [0001]     [Industrial applications]   The present invention relates to a method for producing a dialkyl carbonate. Learn more
Is an alkylene carbonate represented by the general formula (1) and a compound represented by the general formula (
Transesterification of the alcohol represented by 2) with the alcohol represented by the general formula (3)
The present invention relates to a method for producing a dialkyl carbonate. In this transesterification reaction,
In addition to the target dialkyl carbonate, an alkylene glycer represented by the general formula (4)
Generate calls as well.       [0002]   Embedded image (Where R¹, R^Two, R^ThreeAnd R4 each independently represent a hydrogen atom, an alkyl group,
Nil, aryl, cycloalkyl, alkoxyalkyl or alkoxy
Represents a group, R^FiveRepresents an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an aryl
Represents a kill group, a cycloalkyl group or an alkoxyalkyl group)       [0003]   Dialkyl carbonate is used for solvents, gasoline additives, etc.
Highly safe and easy-to-handle carbon dioxide alternative to phosgene and dimethyl sulfate
It is a compound that demand is expected to grow in the future as an oxidizing agent and an alkylating agent.       [0004]     [Prior art]   As a method for producing dialkyl carbonate, alkylene carbonate and alcohol
There have been proposed various methods for subjecting a polyester to a transesterification reaction. The basic technology
Is a transesterification catalyst and is classified into a homogeneous catalyst and a heterogeneous catalyst.       [0005]   As the homogeneous catalyst, for example, an alkali metal or an alkali metal derivative (US
Patent No. 364858, JP-B-61-16267), tertiary aliphatic amines (
JP-B-59-28542), alkyltin alkoxide (JP-B-56-407)
No. 08), alkoxides of zinc, aluminum and titanium (JP-B-60-226)
No. 97), thallium compound (JP-B-60-27658), Lewis acid and nitrogen-containing
Compounds of organic bases (JP-B-60-22698) and phosphine compounds (JP-B-61-1986)
-4381), quaternary phosphonium salt (JP-A-56-10144), Group V element
-Containing Lewis base and epoxide or cyclic amidine (JP-A-59-106)
No. 436) has been proposed.       [0006]   In these methods using a homogeneous catalyst, high catalytic activity can be obtained with a small amount of addition.
However, it is difficult to separate the catalyst from the reaction solution. This es
The tell-exchange reaction is an equilibrium reaction.
When trying to separate the kill carbonate, an equilibrium shift occurs during distillation and a reverse reaction occurs.
The dialkyl carbonate once formed returns to the alkylene carbonate. Also
, The presence of a catalyst causes decomposition, polymerization, etc. to occur simultaneously, resulting in poor efficiency in the purification process.
And it was not desirable in the process.       [0007]   On the other hand, in the case of a heterogeneous catalyst, it is easy to separate the catalyst from the reaction solution,
The above-mentioned problem encountered in the mono-system catalyst is solved.   Ion exchange resins as heterogeneous catalysts, especially quaternary ammonium groups as exchange groups
A method using a solid strong basic anion exchange resin has been proposed.
64-31737, JP-A-63-238043). These methods are relatively expensive
Although it exhibits high catalytic activity, it has problems in heat resistance and durability for industrial use, In particular, decomposition of nitrogen-containing compounds from quaternary ammonium groups occurs under high temperature conditions,
There was a problem that the medium component was dissolved in the reaction solution.       [0008]   As a heterogeneous catalyst, silica-titania solid acid (Japanese Patent Publication No. 61-5467)
No.); Alkali metal or alkaline earth metal silicate-supported silica, ammonium
Exchanged zeolite (JP-A-64-31737); zirconium, titanium, tin
Oxides (JP-A-63-41432); lead compounds (JP-A-4-9356).
Methods using any inorganic solid catalyst have been proposed. These methods are generally catalytic
The activity was low and it was hardly applicable for practical use.       [0009]   Furthermore, in recent years, hydrotalls containing MgO and Al2O3 as heterogeneous catalysts have been developed.
A method using a site compound (JP-A-3-43354) or a method using a composite oxide
A law (European Patent Publication No. 478073) has been proposed. These methods are described above
Although the catalytic activity is improved over the method, it is still not satisfactory,
Transesterification takes a long time to reach equilibrium or requires high reaction temperature
There is still a problem.       [0010]     [Problems to be solved by the invention]   An object of the present invention is to provide a transesterification reaction between an alkylene carbonate and an alcohol.
In the method for producing a dialkyl carbonate, the prior art
Industrially advantageous using a solid catalyst with excellent catalytic activity and durability.
An object of the present invention is to provide a method for producing an alkyl carbonate.       [0011]     [Means for Solving the Problems]   The present inventors have conducted a transesterification reaction between an alkylene carbonate and an alcohol.
After diligently studying a method for producing a dialkyl carbonate,
It was found that the above object was achieved by using a rare earth element oxide as a medium.
The present invention has been completed.       [0012]   That is, the present invention relates to an alkylene carbonate represented by the general formula (1).
In the general formula (3), a transesterification reaction between the alcohol represented by the general formula (2) and
In the method for producing dialkyl carbonate shown, yttrium and lanthanum
At least one oxide of rare earth elements consisting of nido (lanthanum series element)
Dialkyl carbonate characterized by using a catalyst containing as a catalytically active component
It is a manufacturing method of. Hereinafter, the present invention will be described in detail.       [0013]   The alkylene car represented by the general formula (1) used as a raw material in the present invention
The carbonate is, for example, ethylene carbonate, propylene carbonate, 1,2
, -Butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene
Carbonate, styrene carbonate, 3-methoxy-1,2-propylene carbonate
Carbonate, 3-ethoxy-1,2-propylene carbonate, and the like,
These mixtures may be used. Among them, industrially easily available
What can be done and the utility value of the by-product alkylene glycol represented by the general formula (4)
Of ethylene carbonate or propylene carbonate
Is industrially useful.       [0014]   In the present invention, an aluminum compound represented by the general formula (2) used as another raw material
Cole is, for example, methyl alcohol, ethyl alcohol, propyl alcohol
, Isopropyl alcohol, butyl alcohol, isobutyl alcohol, t-
Butyl alcohol, pentyl alcohol, hexyl alcohol, octyl alcohol
, 2-ethylhexyl alcohol, decyl alcohol, dodecyl alcohol
, Tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol
, Allyl alcohol, benzyl alcohol, cyclohexyl alcohol, ethyl
Glycol monomethyl ether, ethylene glycol monoethyl ether,
Tylene glycol monopropyl ether, ethylene glycol monobutyl ether
Diethylene glycol monomethyl ether, diethylene glycol monoethyl
And a mixture thereof. these
Among them, the demand for dimethyl carbonate as dialkyl carbonate to be produced
Is large Because of its strength, methyl alcohol is industrially useful.       [0015]   By the combination of these raw materials, alkylene carbonate and alcohol,
The dialkyl carbonate represented by the general formula (3) and the general formula
The alkylene glycol represented by (4) is produced.       [0016]   In the present invention, the catalyst is a rare earth element composed of yttrium and lanthanide.
At least one of the oxides is contained as a catalytically active component. Lantani
La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho,
Er, Tm, Yb and Lu are included. The catalytically active component is one of those elements
Or not only those consisting of two or more oxides, but also those other than those elements
Also includes those containing elemental compounds. The catalyst of the present invention is a catalyst for these rare earth elements.
It is essential to use an oxide as a catalyst. Oxides of rare earth elements are generally acids
An oxide of the formula 3 is formed, but an oxide of the oxidation number 4 or a higher oxide is used.
Or a lower oxide having an oxidation number of less than 3, or a mixture thereof.
However, there is no particular limitation. Among these rare earth element oxides, yttrium oxide
Lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, rare earth
An oxide of a mixture of elements (referred to as mixed rare earth element) is preferred because it is industrially easy to use.
Good. In order to produce oxides of these rare earth elements, for example, a rare earth element
Method of firing acid salts, acetates, nitrates, hydroxides, carbonates, etc. in air
Can be. It is also possible to use rare earth oxides that are generally sold.
You.       [0017]   The catalyst oxide used in the present invention is porous and has a large specific surface area.
It is preferable because the property can be obtained. Specific surface area is usually 5-500m^Two/ G, more preferred
Is 10 to 300 m^Two/ G of rare earth element oxide is used. Specific surface area
5m^Two/ G is not preferable because sufficient catalytic activity cannot be obtained. Also, the ratio
Surface area is 500m^Two/ G, the strength of the catalyst decreases, and there is a problem in durability.
It is not preferable because it occurs.       [0018]   The oxide of the catalyst used in the present invention may be carbon dioxide or moisture before use as a catalyst.
Heat treatment in a stream of inert gas such as nitrogen to remove surface adsorbates.
It is preferable to activate by. The processing temperature at that time is 100 ° C to 1000 ° C
, More preferably in the range of 200 to 800 ° C. Processing temperature is not 100 ° C
If it is full, the desorption of the adsorbed substance becomes insufficient, which is not preferable. When the processing temperature is 10
If the temperature exceeds 00 ° C., heat treatment is costly, and rare earth element oxides are partially contained.
It is not preferable because it melts and the surface area decreases. Activation time is the amount of surface adsorbate
And is not particularly limited because it depends on the processing temperature.
The range is 0 hours.       [0019]   In the present invention, the shape of the oxide used as the catalyst is not particularly limited,
In order to facilitate liquid permeability at the time of separation and to facilitate catalyst separation after the reaction,
No. Its form is a general method such as granulation and tableting even with a fine powder of about 100 μm.
What was molded with can be used.       [0020]   In preparing the catalyst used in the present invention, an appropriate binder may be used.
it can. The binder binds the oxide solids of the catalyst and increases the mechanical strength of the catalyst.
To inhibit the reaction according to the present invention or to remove rare earth elements.
Inorganic or organic substances that do not inhibit the catalytic activity of the oxide
May be. In addition, the binder exhibits a certain degree of catalytic activity for the reaction.
There is no particular limitation. Specific examples of the binder used in the present invention include silica sol.
Sol, alumina sol, zirconia sol, organic polymer and the like.       [0021]   In preparing the catalyst used in the present invention, an appropriate carrier may be used.
. The support is made by dispersing a rare earth element oxide on its surface to make a high surface area catalyst or
It is used for the purpose of increasing the mechanical strength of the medium. The carrier may inhibit the reaction or rare earth
There is no particular limitation as long as it does not inhibit the catalytic activity of the oxides of the similar elements.
The catalyst may exhibit a certain degree of catalytic activity. Carrier used in the present invention
of Specific examples include silica, alumina, zirconia, titania, silica-alumina
, Zirconia-titania, silica-zirconia, alumina-titania, silica-
Inorganic carrier such as titania, alumina-zirconia; kaolinite of kaolinite family
, Dickite, halloysite, chrysotile, lizardite, amesite
Montmorillonite, beidellite, saponite, hectora
And mica tribe mica, paragonite, phlogopite, biotite,
Clay minerals such as hydrotalcite and talc;
You.       [0022]   Composition of Alkylene Carbonate and Alcohol Used as Raw Materials in the Present Invention
The ratio is theoretically 2 in molar ratio, but is not particularly limited,
In addition, it can be used in a wide range. Since the reaction is an equilibrium reaction,
Increase the alcohol ratio to improve the conversion of alkylene carbonate
Preferably, the molar ratio of the alkylene carbonate to the alcohol is 1-2.
It is preferably in the range of 2 to 10.       [0023]   In the present invention, the applicable range of the reaction temperature varies depending on the type of the raw material and the activity of the catalyst.
However, it is generally in the range of 30 to 300 ° C, more preferably in the range of 50 to 200 ° C.
. At that time, the pressure is defined by the vapor pressure of the reaction solution, and there is no particular limitation.
, Has little effect on the transesterification reaction.       [0024]   In the present invention, an alkylene carbonate and an alcohol are separated in the presence of a catalyst.
The method of the tell exchange reaction may be a batch type reaction or a flow type reaction.
It is not specified.       [0025]   The amount of the catalyst used in the case of performing a batch reaction is 0.1 to 30 wt.
%, More preferably in the range of 1 to 15% by weight. In a batch reactor, the present invention
A predetermined amount of catalyst and raw materials are charged, and transesterification is performed at a predetermined temperature with stirring.
By reaction, a reaction mixture containing the desired dialkyl carbonate is obtained.
Can be At that time, the reaction time varies depending on the reaction temperature and the amount of the catalyst used, but is generally 0
. A range of 1 to 100 hours, more preferably 1 to 30 hours is used. Thus obtained
The catalyst is easily separated from the reaction solution containing the catalyst by filtration, centrifugation, etc.
Dialkyl carbonate and by-product alkylene from the reaction solution from which the catalyst was separated
Glycols, unreacted alkylene carbonates and alcohols are generally distilled
In some cases, it can be recovered by a method such as extraction or recrystallization.       [0026]   When performing a flow-type reaction, any of fixed bed, fluidized bed, and stirred tank systems is used.
Can also be used. The liquid passing condition at this time is a liquid hourly space velocity (LH
SV), the range of 0.1 to 50 / hr, more preferably 0.2 to 10 / hr.
An enclosure can be used.       [0027]     【The invention's effect】   According to the method of the present invention, dialkyl carbonate is converted from alkylene carbonate and alcohol.
The transesterification reaction to the carbonate proceeds rapidly and the rare earth element acid
Since the compound is insoluble in the reaction solution, it is easy to separate the catalyst from the reaction solution,
Due to reverse reaction, decomposition, polymerization reaction, etc. due to residual catalyst in distillation process seen in catalyst
A decrease in yield can be prevented. Therefore, industrially important dialkyl carbonates can be efficiently
It can be produced efficiently and contributes to the development of industry.       [0028]     【Example】   Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.
The invention is not so limited.   The conversion and yield in the examples were determined by the following equations.       [0029]   (Equation 1)       [0030]     Embodiment 1   95.7 g of yttrium nitrate hexahydrate was dissolved in 1000 g of water, and yttrium nitrate was dissolved.
To obtain an aqueous solution. Under stirring, the yttrium nitrate aqueous solution is heated to 80 ° C.
500 g of an aqueous solution of Monia was added dropwise over 2 hours, and the mixture was further stirred at 80 ° C. for 5 hours.
Then, a slurry of yttrium hydroxide was obtained. This slurry is separated by filtration, and the filtrate p with pure water.
Washing was sufficiently performed until H became neutral to obtain a hydrate of yttrium hydroxide. Thus obtained
After drying the obtained yttrium hydroxide in air at 120 ° C.,
Calcined at 500 ° C for 5 hours and then at 500 ° C for 5 hours in nitrogen
Yttrium oxide was obtained and used as catalyst (1). This catalyst has a specific surface area of 58 m.^Two/ G
Met.       [0031]   1 mol of ethylene carbonate was added to an autoclave equipped with a stirrer and thermometer.
88 g), methyl alcohol 2 mol (64 g), catalyst (1) 15.2 g (reaction liquid
Of 10% by weight), heated and reacted at a reaction temperature of 100 ° C. for 2 hours. Responded. The reaction pressure was the expected pressure. After the reaction, collect the reaction solution and
The composition of the reaction solution was analyzed by body chromatography. Table 1 shows the results.       [0032]     Embodiment 2   Lanthanum nitrate hexahydrate in place of yttrium nitrate hexahydrate in Example 1
A lanthanum oxide was prepared in the same manner as in Example 1 except that 108 g was used.
Medium (2). This catalyst has a specific surface area of 49 m.^Two/ G.   Example 1 was the same as Example 1 except that the catalyst (2) was used in place of the catalyst (1).
Transesterification was performed in the same manner. Table 1 also shows the results.       [0033]     Embodiment 3   Cerium nitrate hexahydrate instead of yttrium nitrate hexahydrate in Example 1
Cerium oxide was prepared in the same manner as in Example 1 except that 109 g was used.
The medium (3) was used. This catalyst has a specific surface area of 53 m.^Two/ G.   Example 1 was the same as Example 1 except that the catalyst (3) was used instead of the catalyst (1).
Transesterification was performed in the same manner. Table 1 also shows the results.       [0034]     [Comparative Example 1]   Hydrotalcite compounds (composition formula: Mg₆Al_Two(OH)₁₆CO_Three
・ 4H_TwoTransesterification and analysis in the same manner as in Example 1 except that O) was used.
Was done. This catalyst has a specific surface area of 88 m.^Two/ G. The analysis results
It is shown in Table 1.       [0035]   [Table 1]      [0036]   From the results of Examples 1 to 3 and Comparative Example 1, any of the examples under this reaction condition
Also, the composition of the reaction solution reached the equilibrium composition and the reaction was apparently terminated. For it
Although the catalyst of Comparative Example 1 has a larger specific surface area than the catalysts of Examples 1 to 3,
Under the above reaction conditions, the composition of the reaction solution has not yet reached the equilibrium composition. From this,
The catalysts of Examples 1 to 3 have a higher reaction rate and a higher catalytic activity than the catalyst of Comparative Example 1.
I understand.       [0037]     Embodiment 4   5.08 g of yttrium nitrate hexahydrate was dissolved in 10.8 g of water, and yttrium nitrate was dissolved.
An aqueous solution was obtained. This yttrium nitrate aqueous solution is mixed with silica gel (Fuji Devison C
ARIACT-30) 15.0 g, and dried in air at 120 ° C.
Thereafter, in air at 500 ° C. for 5 hours, and then in nitrogen at 500 ° C. Calcination for 5 hours to obtain yttrium oxide using silica gel as carrier, and used as catalyst (4)
Was. The supported catalyst had a supported amount of yttrium oxide of 10 wt% and a specific surface area of 110 wt%.
m^Two/ G.       [0038]   10 ml of the catalyst (4) is filled in a tubular reaction tube (inner diameter 10 mm, length 150 mm).
, Ethylene carbonate / methyl alcohol = 1/2 (mol / mol)
The raw material was passed through the metering pump at a space velocity of 2 / hr. Then the pressure
10Kg / cm^TwoAnd immerse the tubular reaction tube in a 100 ° C oil bath to start the reaction.
Was. Sample the reaction solution over time and analyze the composition of the reaction solution by high performance liquid chromatography
did. Table 2 shows the results.       [0039]   [Table 2]       [0040]   According to the results of Example 4, the composition of the reaction solution reached the equilibrium composition under the reaction conditions.
ing. The catalyst activity did not decrease even after 1000 hours of use.
Shows that the durability is high.       [0041]     Embodiment 5   Dissolve 2.00 g of lanthanum nitrate hexahydrate in 7.3 g of water to obtain an aqueous solution of lanthanum nitrate
Was. This lanthanum nitrate aqueous solution was used as γ-alumina (NEOBEAD manufactured by Mizusawa Chemical Industry).   GB-45) After impregnating 15.0 g and drying in air at 120 ° C., empty
5 hours at 500 ° C in air, then 5 hours at 500 ° C in nitrogen
By calcining, lanthanum oxide using γ-alumina as a carrier was obtained, and used as catalyst (5). this
The supported catalyst has a supported amount of lanthanum oxide of 5 wt% and a specific surface area of 194 m.^Two/ G
Was.   Example 4 was repeated except that the catalyst (5) was used instead of the catalyst (4).
Transesterification and analysis were performed in the same manner. Table 3 shows the results.
.   It can be seen that the catalyst of Example 5 also has high durability.       [0042]   [Table 3]       [0043]     Embodiment 6   1 mol of propylene carbonate in an autoclave equipped with a stirrer and thermometer
(102 g), 1.25 mol (40 g) of methyl alcohol, according to the preparation method of Example 1.
The catalyst (1) prepared above was charged with 7.1 g (5% by weight of the reaction solution), heated, and reacted.
The transesterification reaction was performed at a temperature of 160 ° C. for 5 hours. Again, the reaction pressure
Outgoing pressure.   After completion of the reaction, the composition of the reaction solution was analyzed by high performance liquid chromatography. as a result
Propylene carbonate conversion rate 38 mol%, methyl alcohol conversion rate 44 mol
%, Dimethyl carbonate yield 20 mol%, propylene glycol yield 17 mol
%so there were.       [0044]     Embodiment 7   3.82 g of yttrium nitrate hexahydrate and 0.997 g of lanthanum nitrate hexahydrate were added to water.
This was dissolved in 11.5 g to obtain a mixed aqueous solution of yttrium nitrate and lanthanum nitrate. This
Mixed solution of silica gel (CARACT-30 manufactured by Fuji Devison) 15.0
g in air and dried in air at 120 ° C, then in air at 500 ° C.
For 5 hours and subsequently in nitrogen at 500 ° C. for 5 hours.
The oxides of yttrium and lanthanum were obtained and used as catalyst (7). This carrying type
The supported amount of yttrium oxide in the catalyst is 7.5 wt%, and the supported amount of lanthanum oxide is 2.5 wt%.
%, Specific surface area is 110m^Two/ G.   Example 4 was repeated except that the catalyst (7) was used in place of the catalyst (4) in Example 4.
Transesterification and analysis were carried out in the same manner as in Example 4. Table 4 shows the results.
Shown in       [0045]   [Table 4]       [0046]     Embodiment 8   2.99 g of lanthanum nitrate hexahydrate and 0.95 g of cerium nitrate hexahydrate were added to 12.2 g of water.
In 5 g, a mixed aqueous solution of lanthanum nitrate and cerium nitrate was obtained. This mixed aqueous solution
The solution was impregnated with 15.0 g of silica gel (Fuji Devison CARIACT-30)
, After drying in air at 120 ° C., it is pulled in air at 500 ° C. for 5 hours.
Subsequently, the mixture is calcined in a nitrogen atmosphere at 500 ° C. for 5 hours, and a lantern using silica gel as a carrier.
Oxides of cerium and cerium were obtained, and used as catalyst (8). Lanthanum oxide of this supported catalyst
The supported amount of cerium oxide is 7.5 wt%, the supported amount of cerium oxide is 2.5 wt%, and the specific surface area is 109 wt%.
m^Two/ G.   Example 4 was repeated except that the catalyst (8) was used instead of the catalyst (4) in Example 4.
Transesterification and analysis were carried out in the same manner as in Example 4. Table 5 shows the results.
Shown in       [0047]   [Table 5]       [0048]     Embodiment 9   In Example 1, instead of 95.7 g of yttrium nitrate hexahydrate, yttrium nitrate was used.
Except using 84.8 g of thorium hexahydrate and 8.37 g of magnesium nitrate hexahydrate
Is a yttrium oxide partially containing magnesium oxide in the same manner as in Example 1.
Was prepared and used as catalyst (9). The yttrium oxide content of this catalyst is 95% by weight.
, Magnesium oxide content is 5% by weight, specific surface area is 50m^Two/ G.   Example 1 was the same as Example 1 except that the catalyst (9) was used instead of the catalyst (1).
Transesterification and analysis were performed in the same manner. Table 6 shows the results.
.       [0049]     Embodiment 10   In Example 1, instead of 95.7 g of yttrium nitrate hexahydrate, yttrium nitrate was used.
Using 84.8 g of thorium hexahydrate and 9.68 g of aluminum nitrate hexahydrate, 25
% Oxidized aluminum in the same manner as in Example 1 except that 75 g of aqueous ammonia was used.
Yttrium oxide partially containing minium was prepared and used as catalyst (10). This catalyst
Has a yttrium oxide content of 95% by weight, an aluminum oxide content of 5% by weight,
Specific surface area is 59m^Two/ G.   Example 1 Example 1 was repeated except that the catalyst (10) was used instead of the catalyst (1).
The transesterification and analysis were carried out in the same manner as described above. The results are also shown in Table 6.
You.       [0050]   [Table 6]       [0051]   According to the results of Examples 9 and 10, the yttrium oxide contained elements other than rare earth elements.
It can be seen that the catalyst activity is maintained even when the oxide content is about 5%.       [0052]     Embodiment 11   In Example 1, 95.7 g of yttrium nitrate hexahydrate was dissolved in 1000 g of water.
Of mixed rare earth elements (the content of each rare earth element is Cerium 50 wt%, lanthanum 25 wt%, praseodymium 5
wt., 20 wt.% neodymium).
And the same method as in Example 1 except that 130 g of 25 wt% ammonia water was used.
Thus, an oxide of a mixed rare earth element was prepared, and used as a catalyst (11). The ratio of this catalyst
Surface area is 52m^Two/ G.   Example 1 Example 1 was repeated except that the catalyst (11) was used instead of the catalyst (1).
The transesterification and analysis were carried out in the same manner as described above. Table 7 shows the results.
You. Mixed rare earth oxide catalysts also exhibit similar catalytic activity.       [0053]   [Table 7]       [0054]     [Comparative Example 2]   Ion exchange resin DIAION PA-308 (Mitsubishi Kasei Co., Ltd., grade 4) as a catalyst
Ammonium-type strongly basic anion exchange resin) and 60
Dehydrated by heating at ℃.   Except that the ion exchange resin was used in place of the catalyst (4) in Example 4.
Was subjected to transesterification and analysis in the same manner as in Example 4. as a result
Is shown in Table 8.       [0055]   [Table 8]       [0056]   According to the results of Comparative Example 2, when this catalyst was used for 5 hours, the reaction solution was flat.
The reaction solution has reached the equilibrium composition after 100 hours of use.
Not reached, indicating that the catalytic activity was reduced, the reaction rate was reduced, and the durability was low.
doing. On the other hand, the catalyst of the present invention has a capacity of 1000 as shown in Examples 4 and 7.
Since the reaction speed does not decrease even with the use of time, it can be seen that the durability is high.
You.       [0057]     Embodiment 12   1 mol of ethylene carbonate was added to an autoclave equipped with a stirrer and a thermometer.
90 g), 2 mol (92 g) of ethyl alcohol, prepared according to the preparation method of Example 2.
The catalyst (2) was charged with 18.2 g (10% by weight of the reaction solution) and heated to a reaction temperature of 12%.
The transesterification was performed at 0 ° C. for 2 hours. Also in this case, the reaction pressure
Pressure.   After completion of the reaction, the reaction composition was analyzed by high performance liquid chromatography. as a result
Ethylene carbonate conversion 57 mol%, ethyl alcohol conversion 43 mol%,
The yield of diethyl carbonate is 30 mol% and the yield of ethylene glycol is 29 mol%.
Was.       [0058]     Embodiment 13   In Example 4, the raw material composition was ethylene carbonate / methyl alcohol =
A method similar to that of Example 4 except that a raw material consisting of 1/5 (mol / mol) was used.
To perform transesterification and analysis. Table 9 shows the results.       [0059]   [Table 9]       [0060]   By increasing the proportion of methyl alcohol in the raw material composition,
The conversion of ethylene carbonate in the equilibrium composition increases, and the conversion of methyl alcohol increases.
Conversion and the yield of ethylene glycol and dimethyl carbonate are increasing.
You.

Claims (1)

[Claim 1] General formula (1) (Wherein R ¹ , R ² , R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group or an alkoxy group) And the general formula (2) (Wherein R ⁵ represents an alkyl group having 1 to 20 carbon atoms, an alkenyl group, an arylalkyl group, a cycloalkyl group or an alkoxyalkyl group), which is subjected to a transesterification reaction with an alcohol represented by the following general formula (3): Chemical formula 3] Wherein R ⁵ is the same as described above, wherein a catalyst containing at least one oxide of a rare earth element composed of yttrium and lanthanide as a catalytically active component is used. A method for producing a dialkyl carbonate, comprising: 2. The method according to claim 1, wherein the catalytically active component is an oxide of at least one of yttrium, lanthanum, cerium, praseodymium, and neodymium. 3. The method according to claim 1, wherein the alkylene carbonate is one of ethylene carbonate and propylene carbonate, and the alcohol is one of methyl alcohol and ethyl alcohol. .