JP2009242301A - Method for producing alkylaryl carbonate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an alkylaryl carbonate wherein the transesterification of an aromatic hydroxy compound and a dialkyl carbonate is efficiently carried out. <P>SOLUTION: The method for producing an alkylaryl carbonate by causing an aromatic hydroxy compound and a dialkyl carbonate to react with each other by a gas phase reaction in the presence of a metal composite-oxide comprising titanium and a second metal component comprising group V metal and/or group VI metal in the periodic table, is characterized by using the metal-composite oxide that contains group V metal or group VI metal in the periodic table in an amount of 0.1 to 2.0 mol% relative to the amount of titanium contained therein. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

Carbonate is a useful compound for polycarbonate raw materials not using phosgene, lithium battery electrolytes, gasoline additives for improving octane number, alkylating agents in various reactions, carbonylating agents, and the like.
As a conventional method for producing a carbonate ester, first, a method for producing a carbonate ester by reacting phosgene with an alcohol such as methanol, ethanol or phenol using a carbonylating agent as a carbonylating agent is known and produced on an industrial scale. Has been. However, since this method uses phosgene, which is extremely toxic and corrosive, care must be taken in handling such as transportation and storage, maintenance of manufacturing facilities, waste disposal, ensuring worker safety, etc. Was costly. Therefore, a method for producing a carbonate ester without using phosgene is desired, and various methods have been studied. Known methods for producing carbonate esters without using phosgene include oxidative carbonylation, in which carbon monoxide is used as a carbonylating agent to react with alcohol and oxygen, a method in which oxirane and carbon dioxide are reacted, and a method in which urea and alcohol are reacted. (Non-Patent Document 1).

  As a method for producing a diaryl carbonate, a method for producing a target diaryl carbonate by transesterifying a dialkyl carbonate, such as dimethyl carbonate, which is generally easily available and an aryl compound such as phenols, is known. In general, it is known that the reaction proceeds by a combination of the following reactions.

1) A transalkylation reaction between a dialkyl carbonate and an aromatic hydroxy compound is performed to produce an alkyl aryl carbonate.
2) The alkylaryl carbonate and the aromatic hydroxy compound are transesterified to produce a diaryl carbonate.
3) Diaryl carbonate and dialkyl carbonate are produced by disproportionation of alkylaryl carbonate, and purified and separated.
Both of the above reactions are equilibrium reactions. In particular, since the equilibrium state of the reaction described in 1) is biased toward the raw material side (dialkyl carbonate side), in order to improve the overall reactivity of the diaryl carbonate production reaction, It is important to shift the equilibrium state in the reaction described in 1) to the product side (alkyl aryl carbonate side).

Up to now, as a method for moving the equilibrium state in the reaction described in 1) above to the product side, the reaction described in 1) is performed in a gas phase state, using a catalyst in which titanium oxide is supported on a silica support, A method has been disclosed in which the equilibrium is biased toward the product side (alkyl aryl carbonate side) by carrying out the reaction to advance the reaction (Non-patent Document 2, Patent Document 1). However, in the above reaction, since the reaction is performed at a high temperature, the reaction rate of the side reaction is increased, and there is a difficulty in that the selectivity of the alkylaryl carbonate tends to be lowered.
Ullmann's Encyclopedia Of Industrial Chemistry, 6th Edition, Vol.6 P427-455 Catalysis Letters, 59, 83-89 (1999) WO2001-00560

  This invention makes it a subject to provide the manufacturing method of the alkyl aryl carbonate which performs efficiently the transesterification reaction of an aromatic hydroxy compound and a dialkyl carbonate. Furthermore, it is an object to provide a method for producing a diaryl carbonate using the alkylaryl carbonate produced as described above, and a method for producing a polycarbonate using the diaryl carbonate.

  As a result of intensive studies to solve the above problems, the present inventors have found that when transesterification of an aromatic hydroxy compound and a dialkyl carbonate is carried out in the gas phase, titanium and group V or group of the periodic table are used. It has been found that the selectivity can be improved while maintaining a sufficient reaction rate by using, as a catalyst, a metal composite oxide containing a second metal component composed of a metal of VI at a specific content. It came to complete.

That is, the present invention
(1) An aromatic hydroxy compound and a dialkyl carbonate are reacted by a gas phase reaction in the presence of titanium and a metal complex oxide containing a second metal component made of a group V and / or VI metal of the periodic table. In the method for producing an alkylaryl carbonate, the content of the second metal component in the metal composite oxide is 0.1 to 2.0 mol% with respect to the titanium content. ,
(2) The method for producing an alkylaryl carbonate according to (1), wherein the second metal component is vanadium,
(3) The method for producing an alkylaryl carbonate according to the above (1) or (2), wherein the aromatic hydroxy compound is phenol, the dialkyl carbonate is dimethyl carbonate, and the alkylaryl carbonate is methylphenyl carbonate,
(4) A method for producing a diaryl carbonate, comprising transesterifying the alkylaryl carbonate produced by the method described in (1) to (3) above,
(5) The method for producing a diaryl carbonate according to (4), wherein the diaryl carbonate is diphenyl carbonate,
(6) A method for producing a polycarbonate, comprising melt-polymerizing diphenyl carbonate and bisphenol A produced by the method described in (5) above,
It is.

  INDUSTRIAL APPLICABILITY According to the present invention, there is provided a method with high selectivity while maintaining a sufficient reaction rate in a method for producing an alkylaryl carbonate by transesterification of an aromatic hydroxy compound and a dialkyl carbonate. Further, a method for producing diaryl carbonate using the alkylaryl carbonate thus produced as a raw material, and further using this to produce polycarbonate efficiently without using harmful components has been provided.

  The process for producing an alkylaryl carbonate according to the present invention includes the presence of a metal complex oxide comprising an aromatic hydroxy compound and a dialkyl carbonate, titanium, and a second metal component comprising a Group V or Group VI metal of the Periodic Table. In the method for producing an alkylaryl carbonate to be reacted by a gas phase reaction under the above condition, the content of the second metal component in the metal composite oxide is 0.1 to 2.0 mol% with respect to the titanium content. It is characterized by being.

(material)
Examples of the aromatic hydroxy compound used in the method of the present invention include an aromatic monohydroxy compound, an aromatic dihydroxy compound, and an aromatic trihydroxy compound depending on the number of hydroxy groups substituted on the aromatic ring. Group monohydroxy compounds are preferred. Specifically, for example, phenol, cresol, xylenol, alkylphenol having an alkyl group having 1 to 12 carbon atoms such as 2- (or 3-, 4-) ethylphenol, 2- (or 3-, 4-) Alkoxyphenol having an alkoxy group having 1 to 12 carbon atoms such as methoxyphenol and 2- (or 3-, 4-) ethoxyphenol, and nitro having a nitro group such as 2- (or 3-, 4-) nitrophenol Halogenophenol having a halogen atom such as phenol, 2- (or 3-, 4-) fluorophenol, 2- (or 3-, 4-) chlorophenol, naphthol such as α-naphthol, β-naphthol, etc. Among these, phenol is particularly preferable.

  In addition, as the dialkyl carbonate, a carbonate having a linear alkyl group having 1 to 12 carbon atoms and a branched alkyl group such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, diisopropyl carbonate, dibutyl carbonate, diisobutyl carbonate, dihexyl carbonate, dioctyl carbonate, etc. Is good. Moreover, the carbonate which has two different alkyl groups like methyl ethyl carbonate may be sufficient, and cyclic carbonates, such as ethylene carbonate and propylene carbonate, may be sufficient. Of these, dimethyl carbonate is particularly preferred.

(Metal composite oxide)
The metal composite oxide used in the method of the present invention includes titanium and a second metal component composed of a Group V or Group VI metal of the periodic table, and includes the second metal component in the metal composite oxide. Content of a metal component is 0.1-2.0 mol% with respect to titanium content, It is characterized by the above-mentioned. This metal composite oxide can be prepared using a method for preparing a normal composite oxide catalyst. Specifically, for example, a powder obtained by drying an aqueous solution (or aqueous dispersion) containing titanium and the metal element of the second metal component or a compound thereof is heat-treated, and then molded and fired. (For example, Kodansha Scientific Catalyst Preparation Chemistry, Kodansha (1980), p214-215), but is not particularly limited thereto.

  Specific examples of titanium, Group V and Group VI metal element compounds in the periodic table include titanium, Group V and Group VI metal compound halides, sulfates and nitrates in the Periodic Table , Ammonium salts, oxides, carboxylates, ammonium carboxylates, ammonium halides, hydrogen acids, acetylacetonates, alkoxides, and the like. Of these, titanium tetrachloride is preferable as the titanium compound, and ammonium salts are preferable as the metal compounds of Group V and Group VI of the periodic table.

The second metal component in the metal composite oxide of the present invention is vanadium, niobium, tantalum, chromium, molybdenum, tungsten or the like, and in the metal composite oxide, at least one or more of them as the second metal component. Is included. Of these, vanadium and molybdenum are preferable, and vanadium is particularly preferable. The total content of these second metal components relative to titanium in the metal composite oxide is 0.1 to 2.0 mol%, more preferably 0.1 to 1.0 mol%. When the content of the second metal component in the metal composite oxide is less than 0.1 mol% with respect to the titanium content, there is a problem that the specific surface area and pore volume are not sufficiently obtained. If the amount is too large, the acid strength is greatly affected, and there is a problem that the acid strength becomes too strong or too weak. As for the acid strength, for example, based on the method described in Non-Patent Document 2, a metal having a more optimal acid strength depending on selection of two or more kinds of metals to be mixed, composition at the time of mixing, catalyst firing conditions, and the like. It is also possible to prepare a composite oxide.
The metal composite oxide of the present invention includes, in addition to the above-mentioned titanium, Group V or Group VI metal of the periodic table, alkali metals such as sodium and magnesium, alkaline earth metals, iron, zirconium, cerium, tungsten It may further contain a metal such as

(Transesterification reaction)
The transesterification performed in the method for producing an alkylaryl carbonate of the present invention is performed in the gas phase. The reaction conditions and method can be appropriately selected from commonly used methods according to the reaction raw materials, catalysts, equipment, etc., but the temperature at which both the aromatic hydroxy compound and dialkyl carbonate as raw materials are in a gaseous state, It must be a condition. Specifically, the reaction is preferably performed at a temperature of 320 to 600 ° C. The amount of the metal composite oxide is preferably in a range where the space velocity (SV) is 1000 to 10,000.

In the transesterification reaction of the present invention, since the liquid is not stabilized for a while after the start of the liquid flow, it is preferable to start the reaction after passing the reaction liquid to some extent. The liquid passing time for stabilization is preferably 8 hours or longer after the start of liquid passing, and more preferably 12 hours or longer.
The alkylaryl carbonate thus produced can be appropriately purified and obtained by a commonly used method known per se.

(Method for producing diaryl carbonate)
The alkylaryl carbonate obtained by the method for producing an alkylaryl carbonate of the present invention is disproportionated in the liquid phase in the presence of an acidic catalyst to remove the resulting dialkyl carbonate, thereby producing a diaryl carbonate. A known catalyst can be used as the acidic catalyst.
The disproportionation reaction can be carried out at a known temperature and pressure, but it is preferable to carry out the reaction under reaction conditions of 150 to 250 ° C. and 0.01 to 2.0 Pa. Although there is no restriction | limiting in the removal method of the dialkyl carbonate to produce | generate, The method of advancing reaction, removing a product with a reactive distillation apparatus is preferable. If necessary, purification such as removal of residual catalyst may be further performed.

(Polycarbonate production method)
As the dialkyl carbonate obtained as described above, with respect to diphenyl carbonate, bisphenol A can be reacted in the presence of an alkali catalyst to produce a polycarbonate. Examples of the production method of this polycarbonate include known methods that are generally used. For example, the method described in Plastic Materials, Polycarbonate Resin, Second Edition, p62-65, Nikkan Kogyo Shimbun (1976) is used. It is done. In addition, as alkali catalysts, alkali metal hydroxides such as sodium hydroxide, various salts such as carbonates such as sodium carbonate and cesium carbonate, ammonium hydroxide compounds such as tetramethylammonium hydroxide, etc. are used. can do.

  The reaction temperature is preferably raised stepwise as the polymerization proceeds in the range of 120 to 300 ° C, and the temperature of the final polymerization step is preferably 250 ° C to 300 ° C. The reaction pressure is preferably increased stepwise as the polymerization proceeds, and the pressure reduction in the final polymerization step is preferably 1 kPa or less.

EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited to a following example, unless the summary is exceeded.
Example 1
(1) Preparation of metal composite oxide 500 g of titanium tetrachloride (manufactured by Wako Pure Chemical Industries, Ltd., special grade reagent) was dropped into 1.5 L of pure water at 10 ° C. or less to obtain a 25 wt% titanium tetrachloride aqueous solution. 400 ml of this titanium tetrachloride aqueous solution (51.67 g in titania conversion) was neutralized at a low temperature of 5 to 10 ° C. with an aqueous ammonia solution (manufactured by Wako Pure Chemical Industries, Ltd., special grade reagent) prepared to 4N, and the resulting hydrogel was Then, suction filtration and pure water washing were performed to obtain a titanium hydrogel cake. The obtained hydrogel cake was dispersed in pure water, and 302.7 mg of ammonium metavanadate (manufactured by Shinsei Chemical Industry Co., Ltd., industrial reagent) was added as an aqueous solution, followed by mixing and stirring (7500 rpm, 15 minutes) with a disperser. The obtained slurry solution was concentrated and dried overnight at 300 ° C. in a constant temperature dryer, and subjected to salt decomposition.

  Next, water was added to the obtained solid, and it was pulverized and mixed with an automatic mortar until it became creamy. This creamy slurry was transferred to a Teflon (registered trademark) vat and dried overnight at 150 ° C. with a circulation dryer. The obtained solid was molded into a disk shape of about 2 cmφ with a press molder, and then fired in a muffle furnace at 450 ° C. for 3 hours to obtain a metal composite oxide. All the above operations were performed in air. Table 1 shows the molar composition of metal components in the catalyst calculated from the charged amount.

(2) Reaction and Analysis The metal composite oxide obtained in (1) above was pulverized and granulated to 10 to 20 mesh for evaluation as a catalyst, and filled into a SUS reaction tube having an inner diameter of 10 mm. Thereafter, a ceramic heater was attached around the reactor and heated to 400 ° C. over 1 hour while flowing nitrogen gas at 0.5 L / hr. Next, a dimethyl carbonate-phenol mixed solution (dimethyl carbonate: phenol (molar ratio) = 10: 1) was fed to the reaction tube at 12 ml / hr for 12 hours using a plunger pump. The space velocity (SV) at this time was 1800.

  The obtained reaction product was collected every hour, and gas chromatography (Shimadzu GC-1700 and 2014 column: TC-5 manufactured by GL Sciences, column temperature: 50 ° C. to 300 ° C., inlet temperature: 300 ° C. ), The yield of methyl phenyl carbonate was 26.5% in the collected liquid with a passing time of 8 hours, the selectivity was 96.6%, and the yield of methyl phenyl carbonate in the collected liquid with a flowing time of 12 hours. Was 23.6% and the selectivity was 96.9%. The results are shown in Table 1.

Example 2
Catalyst preparation, reaction, and analysis were performed in the same manner as in Example 1 except that in the catalyst preparation of Example 1, the amount of ammonium metavanadate added was 151.4 mg.
In the reaction and analysis, the yield of methyl phenyl carbonate was 21.9% when the sample was collected for 8 hours, and the selectivity was 96.4%. The yield of methyl phenyl was obtained when the sample was collected for 29 hours. Was 13.1% and the selectivity was 95.0%. The results are shown in Table 1.

Example 3
In the catalyst preparation of Example 1, the catalyst preparation, reaction, and analysis were performed in the same manner as in Example 1 except that the amount of ammonium metavanadate added was 717.1 mg.
In the reaction and analysis, the yield of methyl phenyl carbonate was 14.6% in the collected liquid with a flow time of 8 hours, the selectivity was 90.5%, and the yield of methyl phenyl carbonate in the collected liquid with a flow time of 29 hours. Was 9.6% and the selectivity was 91.0%. The results are shown in Table 1.

Example 4
In preparing the catalyst of Example 1, 200 ml of titanium tetrachloride aqueous solution (25.83 g in titania conversion) was used, and 228.5 mg of ammonium paramolybdate (manufactured by Nippon Inorganic Chemical Industries, Ltd., industrial reagent) was added as an aqueous solution. Further, the catalyst was prepared in the same manner as in Example 1 except that the baking condition of the catalyst was 500 ° C. and 4 hours.
As a result of reaction and analysis in the same manner as in Example 1, the yield of methyl phenyl carbonate was 18.1%, the selectivity was 95.5%, and the collection time was 30 hours. The yield of methyl phenyl carbonate in the liquid was 12.1%, and the selectivity was 97.6%. The composition of the catalyst used in Examples 1 to 4 and the results of the reaction are shown in Table 1.

Comparative Example 1
In the catalyst preparation of Example 1, the catalyst preparation, reaction, and analysis were performed in the same manner as in Example 1 except that the amount of ammonium metavanadate added was 7.171 g.
In the reaction and analysis, the yield of methyl phenyl carbonate was 2.7% when the sample was collected for 8 hours and the selectivity was 82.3%. The yield of methyl phenyl was obtained when the sample was collected for 29 hours. Was 1.4% and the selectivity was 81.2%. The results are shown in Table 1.

Comparative Example 2
In the catalyst preparation of Example 1, 652 ml of titanium tetrachloride aqueous solution (84.22 g in titania conversion) was used, and 57.03 g of silica gel Aerodiesel (manufactured by Aerodiesel, Japan, industrial reagent) was added in place of ammonium metavanadate. did. Further, the catalyst was prepared in the same manner as in Example 1 except that the baking condition of the catalyst was 500 ° C. and 4 hours.
As a result of performing the reaction and analysis in the same manner as in Example 1, the yield of methyl phenyl carbonate was 6.6% and the selectivity was 91.5% in the collected liquid having a passage time of 8 hours. The results are shown in Table 1.

Comparative Example 3
In the catalyst preparation of Example 1, 100 ml of titanium tetrachloride aqueous solution (38.74 g in titania conversion) was used, and instead of ammonium metavanadate, 50 wt% ammonium metatungstate aqueous solution (manufactured by Nippon Inorganic Chemical Industry) 22.50 g Was added. Further, the catalyst was prepared in the same manner as in Example 1 except that the catalyst firing conditions were 500 ° C. and 3 hours.
As a result of the reaction and analysis, the yield of methyl phenyl carbonate was 2.0% and the selectivity was 62.5% when the sample was collected for 8 hours. The yield was 1.3% and the selectivity was 78.4%. The results are shown in Table 1.

Comparative Example 4
In the catalyst preparation of Example 1, 200 ml of titanium tetrachloride aqueous solution (25.83 g in titania conversion) was used, and in addition to 151.3 mg of ammonium metavanadate (manufactured by Shinsei Chemical Industry), a 50 wt% ammonium metatungstate aqueous solution ( 15.00 g of Nippon Inorganic Chemical Industry) was added. Further, the catalyst was prepared in the same manner as in Example 1 except that the catalyst firing conditions were 500 ° C. and 3 hours.

  As a result of reaction and analysis in the same manner as in Example 1, the yield of methyl phenyl carbonate was 3.9%, the selectivity was 68.3%, and the collection time was 30 hours. The yield of methyl phenyl carbonate in the liquid was 2.9%, and the selectivity was 83.7%. The composition of the catalyst used in Comparative Examples 1 to 4 and the results of the reaction are shown in Table 1.

Example 5 Production of diphenyl carbonate A 1 L stainless steel autoclave equipped with a 30 cm high packed tower was charged with 380 g (2.5 mol) of methylphenyl carbonate obtained in Example 1 and 6.3 g (0 g of dibutyltin oxide). 0.025 mol), and reactive distillation was performed at 180 ° C. and 9.5 atm in a nitrogen atmosphere. The reaction was carried out until dimethyl carbonate extracted from the upper part of the packed column was not distilled.
From the tower bottom, 269 g of a tower bottom liquid mainly composed of diphenyl carbonate was obtained. This was further distilled under reduced pressure at 180 ° C. and 20 Torr in a nitrogen atmosphere to obtain 245 g of high-purity diphenyl carbonate from the top.

Example 6 Production of Polycarbonate 220 g (1.03 mol) of diphenyl carbonate obtained in Example 5, 226 g (1.00 mol) of bisphenol A (manufactured by Mitsubishi Chemical Corporation), and cesium carbonate as a catalyst in an aqueous solution (0.005 mol / l) ) Was added in 0.1 ml, charged in a polymerization apparatus capable of stirring at high viscosity, purged with nitrogen, and then heated and melted to 210 ° C. After reducing the pressure to 100 Torr and reacting for 60 minutes while removing the distilling phenol, 240 degreeC, 15 Torr, 260 degreeC, 0.5 Torr, 270 degreeC, 0.5 Torr and the degree of pressure reduction and temperature stepwise. While raising, each was reacted for 60 minutes to obtain a transparent polycarbonate. The viscosity average molecular weight of the obtained polycarbonate was Mv = 20000.

Claims (6)

  Alkylaryl which reacts aromatic hydroxy compound and dialkyl carbonate by gas phase reaction in the presence of titanium and metal complex oxide containing second metal component consisting of group V and / or group VI metal of periodic table In the method for producing carbonate, the content of the second metal component in the metal composite oxide is 0.1 to 2.0 mol% with respect to the titanium content.  The method for producing an alkylaryl carbonate according to claim 1, wherein the second metal component is vanadium.   The method for producing an alkylaryl carbonate according to claim 1 or 2, wherein the aromatic hydroxy compound is phenol, the dialkyl carbonate is dimethyl carbonate, and the alkylaryl carbonate is methylphenyl carbonate.   A process for producing a diaryl carbonate, comprising transesterifying the alkylaryl carbonate produced by the method according to claim 1.   The method for producing a diaryl carbonate according to claim 4, wherein the diaryl carbonate is diphenyl carbonate. A method for producing a polycarbonate, comprising melt-polymerizing diphenyl carbonate and bisphenol A produced by the method according to claim 5.