JPH10158222A - Production of diaryl carbonate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a diaryl carbonate continuously at a high reaction rate with high selectivity even industrially preferable low reaction temperature in a method for producing the diaryl carbonate by a decarbonylation of diaryl oxalate. SOLUTION: This production of a diaryl carbonate comprises continuously feeding diaryl oxalate and a decarbonylation catalyst in liquid state into a first reaction region of a reactor having a plurality of reaction regions in the liquid phase, sequentially leading the liquid phase into the continual reaction regions, and continuously extracting the reaction liquid, which contains the diaryl carbonate, from the final reaction region while removing the formed carbon monoxide from the top of the reaction region, thus carrying out the decarbonylation of the diaryl oxalate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a diaryl carbonate useful as a raw material for producing a polycarbonate.

[0002]

2. Description of the Related Art As a method for producing diaryl carbonate,
A method of producing a diaryl carbonate by decarbonylating a diaryl oxalate is known, but this method has a low reaction rate, a low selectivity and a low yield of the diaryl carbonate, and a high reaction temperature. However, it is very disadvantageous industrially. For example, a method of producing diphenyl carbonate by boiling diphenyl oxalate in a distillation flask without a catalyst [Journal of Organic Synthetic Chemistry, 5th edition]
Vol. 4-9, No. 47 (1948), 70], the reaction rate is low, and the reaction is carried out at a high temperature without a catalyst. However, when the reaction temperature is low, diphenyl carbonate is hardly obtained.

[0003] A method of producing dialkyl carbonate by heating a dialkyl oxalate or the like in the liquid phase at 50 to 150 ° C in the presence of an alcoholate catalyst (US Pat. No. 4,544,507) has also been reported. According to the example, even when diphenyl oxalate is heated in the presence of a potassium phenolate catalyst, the main product obtained is the starting diphenyl oxalate. As described above, there is no known method capable of continuously producing a diaryl carbonate at a high reaction rate and a high selectivity at an industrially suitable low reaction temperature by a decarbonylation reaction of the diaryl oxalate.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a method for producing a diaryl carbonate by decarbonylating a diaryl oxalate at a high reaction rate and a high selectivity even at an industrially suitable low reaction temperature. It is an object of the present invention to provide a method which can be manufactured continuously by using the method.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reaction apparatus having a liquid phase section having a plurality of reaction zones in a first reaction zone.
The diaryl oxalate and the decarbonylation catalyst are continuously supplied in a liquid phase state, the liquid phase portion of the reaction zone is successively led to a continuous reaction zone, and the reaction liquid containing the diaryl carbonate is continuously fed from the final reaction zone. This is achieved by a method for producing a diaryl carbonate, comprising performing a decarbonylation reaction of a diaryl oxalate while extracting the generated carbon monoxide from the upper part of the reaction zone while extracting.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION A diaryl carbonate is produced by a decarbonylation reaction of a diaryl oxalate represented by the following formula.

[0007]

Embedded image (In the formula, Ar represents an aryl group.)

In the present invention, a reactor having a plurality of reaction zones in the liquid phase is used as the reactor. And
In the first reaction zone, the diaryl oxalate and the decarbonylation catalyst are continuously supplied in a liquid phase state, and the liquid phase portion of the reaction zone is successively led to a continuous reaction zone. Is continuously withdrawn. Further, carbon monoxide generated according to the above reaction formula is continuously or intermittently extracted from the upper portion of the reaction zone. Examples of the decarbonylation catalyst include, for example, an organic phosphorus compound having a trivalent or pentavalent phosphorus atom and having at least one carbon-phosphorus (CP) bond (for example, an organic phosphonium salt, phosphine, phosphine diphosphorus). Halide, phosphine oxide) are preferably used.

Hereinafter, the present invention will be described in detail. Examples of the diaryl oxalate used in the present invention include: (1) a phenyl group, (2) (a) an alkyl group having 1 to 12 carbon atoms such as a methyl group and an ethyl group, (b) a methoxy group, An alkoxy group having 1 to 12 carbon atoms such as an ethoxy group, (c) a halogen atom such as a fluorine atom or a chlorine atom, or (d) a substituted phenyl group having a substituent such as a nitro group, or (3) a naphthyl group. The compound which is is mentioned. Of these aryl groups, a phenyl group is preferred.

The above substituted phenyl group includes various isomers. These isomers include (a) 2- (or 3-, 4-
-) A carbon number of 1 to 2 (or 3- or 4-) such as a methylphenyl group or a 2- (or 3- or 4-) ethylphenyl group;
An alkyl-substituted phenyl group having 12 alkyl groups,
(B) 2- (or 3-, 4-) methoxyphenyl group, 2
An alkoxy-substituted phenyl group having an alkoxy group having 1 to 12 carbon atoms at the 2- (or 3- or 4-) position such as-(or 3- or 4-) ethoxyphenyl group, (c) 2- (or 3
-, 4-) fluorophenyl group, 2- (or 3-, 4)
-) A halogen-substituted phenyl group having a halogen atom at the o- (or m-, p-) position such as a chlorophenyl group, (d)
2- (or 3-, 4-) nitrophenyl group, and the like.

Examples of the diaryl oxalate include diphenyl oxalate, bis (2-methylphenyl) oxalate, bis (3-methylphenyl) oxalate, and bis (4-methylphenyl oxalate).
Methylphenyl), bis (2-chlorophenyl) oxalate, bis (3-chlorophenyl) oxalate, bis (4-chlorophenyl) oxalate, bis (2-nitrophenyl) oxalate, bis (3-nitrophenyl) oxalate ,
Specific examples include bis (4-nitrophenyl) oxalate. Other diaryl oxalates are easily synthesized based on known methods. Among these diaryl oxalates, diphenyl oxalate is preferred.

The organic phosphonium salt used in the present invention is represented by the following general formula.

Embedded image (Wherein R ¹ , R ² , R ³ , and R ⁴ are an aryl group having 6 to 14 carbon atoms, an alkyl group having 1 to 16 carbon atoms, and 7 to 2 carbon atoms)
Represents an aralkyl group of 2, a heterocyclic group having 4 to 16 carbon atoms, or an aryloxy group having 6 to 14 carbon atoms, and X represents an atom or an atomic group capable of forming a counter ion of a phosphonium salt.
Further, these groups may be the same or different from each other, and may be cross-linked between the two groups to form a ring containing a phosphorus atom. )

The aryl, alkyl, aralkyl, heterocyclic, and aryloxy groups represented by R ¹ , R ² , R ³ , and R ⁴ include the following. That is, examples of the aryl group include an aryl group having 6 to 14 carbon atoms such as a phenyl group and a naphthyl group which may have a substituent, and the alkyl group may have a substituent. , A methyl group, an ethyl group, an n- (or i-) propyl group, an n- (or i-, sec-, tert-) butyl group and other alkyl groups having 1 to 16 carbon atoms. A benzyl group, a phenethyl group, a naphthylmethyl group or the like, which may have a substituent, having 7 to 2 carbon atoms.
2 aralkyl groups, and examples of the heterocyclic group include an optionally substituted heterocyclic group having 4 to 16 carbon atoms such as a thienyl group, a furyl group and a pyridyl group, and an aryloxy group Examples thereof include an aryloxy group having 6 to 14 carbon atoms such as a phenoxy group and a naphthoxy group which may have a substituent.

The above-mentioned aryl group, aralkyl group, heterocyclic group and aryloxy group each have an alkyl group having 1 to 15 carbon atoms, an alkoxy group having 1 to 15 carbon atoms, An amino group such as an alkoxycarbonyl group having 12 to 12 carbon atoms, an aryl group having 6 to 14 carbon atoms, an N, N-dialkyl-substituted amino group having 2 to 16 carbon atoms, a cyano group, a nitro group, and a halogen atom such as fluorine, chlorine and bromine. May have one or more substituents (including various isomers such as o, m, and p). The alkyl group is an alkoxy group having 1 to 15 carbon atoms, 2 carbon atoms.
At least one of various substituents such as an alkoxycarbonyl group having from 12 to 12, an amino group having 2 to 16 carbon atoms such as an N, N-dialkyl-substituted amino group, a cyano group, a nitro group, and a halogen atom such as fluorine, chlorine and bromine. You can have it.

As the organic phosphonium salt, for example, R
¹ , R ² , R ³ , and R ⁴ are all aryl groups (tetraarylphosphonium salts), R ¹ , R ² , and R 4
³ or R ⁴ is an aryl group and one is another group, or ^{two of} R ¹ , R ² , R ³ and R ⁴
One is an aryl group and two are different groups,
One of R ¹ , R ² , R ³ , and R ⁴ is an aryl group and three are other groups, and R ¹ , R ² , R ³ ,
R ⁴ is not an aryl group.

Among these organic phosphonium salts,
R ¹ , R ² , R ³ and R ⁴ in which all are aryl groups (tetraarylphosphonium salts), R ¹ , R ² and R 4
Preferably, ^three of R ³ and R ⁴ are aryl groups and one is a heterocyclic group, and among them, R ¹ , R ² ,
Those in which all of R ³ and R ⁴ are aryl groups (tetraaryl phosphonium salts) are preferred.

Examples of the counter ion X ⁻ of the organic phosphonium salt include a halogen ion (chlorine ion, bromine ion, iodine ion, etc.) and a hydrogen dihalide ion (hydrogen dichloride ion, hydrogen dibromide ion, hydrogen diiodide ion). Ion, hydrogen bromide chloride ion, etc.), halogenate ion (chlorate ion, bromate ion, iodate ion, etc.), perhalate ion (perchlorate ion, etc.)
Perbromate ion, periodate ion, etc.) and aliphatic carboxylate ions (acetate ion, trifluoroacetate ion,
Propionate ion), aromatic carboxylate ion (benzoate ion, α- (or β-) naphthalene carboxylate ion, etc.), aromatic hydroxy ion (phenoxide ion, etc.), inorganic acid ion (sulfate ion, etc.) , Hydrogen sulfate ion, phosphate ion, hydrogen phosphate ion, borate ion, hydrogen borate ion, cyanate ion, thiocyanate ion, fluoroborate ion, etc.) and tetraalkylborate ions (tetramethylborate ion, tetraethylborate ion) Having an alkyl group having 1 to 10 carbon atoms, such as a tetraarylborate ion (having an aryl group having 6 to 14 carbon atoms such as tetraphenylborate ion and tetrakis-p-fluorophenylborate ion), and alkyl sulfone Acid or alkylsulfinate ions (methyl group, ethyl group, n- ( Or i-) having an alkyl group having 1 to 16 carbon atoms such as a propyl group), an arylsulfonic acid or an arylsulfinate ion (phenyl group, p
-An aryl group such as -toluyl group and p-nitrophenyl group). These counterions by X ^- Among halogen ions, hydrogen dihalide ion are preferred, among them chlorine ions, hydrogen dichloride ion is particularly preferred.

Specific examples of the organic phosphonium salt include the following compounds. R ¹ , R ² , R
Examples of phosphonium salts wherein all of ³ and R ⁴ are aryl groups and X ⁻ is a halogen ion include tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetraphenylphosphonium iodide, tetrakis (p-chlorophenyl) phosphonium Chloride, tetrakis (p-fluorophenyl) phosphonium chloride, tetrakis (p-tolyl) phosphonium chloride, p-chlorophenyltriphenylphosphonium chloride, p-chlorophenyltriphenylphosphonium bromide, p-chlorophenyltriphenylphosphonium iodide, Tolyl triphenyl phosphonium chloride, p-tolyl triphenyl phosphonium bromide, p-tolyl triphenyl phosphonium ioda De, m- trifluoromethyl or methyl phenyl triphenyl phosphonium chloride, and p- biphenyl triphenyl phosphonium chloride, m- methoxyphenyl triphenyl phosphonium chloride,
p-methoxyphenyltriphenylphosphonium chloride, p-ethoxyphenyltriphenylphosphonium chloride, p-ethoxyphenyltriphenylphosphonium bromide, p-ethoxyphenyltriphenylphosphonium iodide, p-dimethylaminophenyltriphenylphosphonium chloride, -Ethoxycarbonylphenyltriphenylphosphonium chloride, m-cyanophenyltriphenylphosphonium chloride, 1-naphthyltriphenylphosphonium chloride, and 2-thiophenetriphenylphosphonium chloride. Among these organic phosphonium salts, tetraphenylphosphonium chloride is particularly preferred.

Examples of the phosphonium salt in which R ¹ , R ² , R ³ and R ⁴ are all aryl groups and X ⁻ is a hydrogendihalide ion include, for example, tetraphenylphosphonium hydrogendichloride, tetraphenylphosphonium Hydrogen dibromide, tetraphenyl phosphonium hydrogen diiodide, tetraphenyl phosphonium hydrogen bromide chloride are exemplified. Among these phosphonium salts, tetraphenylphosphonium hydrogen dichloride is particularly preferred.

Examples of the phosphonium salt in which ^{three of} R ¹ , R ² , R ³ and R ⁴ are an aryl group, one is a heterocyclic group, and X ⁻ is a halogen ion include 2-thiophenetriene. Phenylphosphonium chloride.

Examples of the phosphonium salt in which ^{three of} R ¹ , R ² , R ³ and R ⁴ are aryl groups, one is an aryloxy group and X ⁻ is a halogen ion include:
Phenoxytriphenylphosphonium chloride is exemplified.

Among the phosphonium salts, those not commercially available can be obtained by a known method [Bull. Chem. Soc. Jp
n. , 56, 2869 (1983); Am. Che
m. Soc. , 70, 737 (1948)]. For example, tetraarylphosphonium chloride is a triarylphosphine and a corresponding aryl halide (iodo or bromo compound)
Is reacted in the presence of a palladium acetate catalyst, and the resulting tetraarylphosphonium iodide or tetraarylphosphonium bromide is converted to tetraarylphosphonium chloride using an ion exchange resin (chlor type). The obtained tetraarylphosphonium chloride is dried at 80 to 200 ° C. for 0.5 to 5 hours under a flow of a dry inert gas such as dry argon gas, and then at a temperature in this range of 0.5 to 5 hours under a flow of hydrogen chloride gas. Treated for 2 hours.

The tetraarylphosphonium salt having a counter ion other than a halogen ion can be obtained by converting the tetraarylphosphonium chloride obtained as described above into an alkali metal salt (sodium salt, potassium salt, etc.) or ammonium having a corresponding counter ion. Reaction with salt (ion exchange)
And synthesized. Other phosphonium salts other than tetraarylphosphonium salts are synthesized by the same method.

As the phosphine represented by the general formula (B), R ⁵ , R ⁶ , and R ⁷ are the same as R ¹ , R ² , R ³ , and R ⁴ in the same aryl group, alkyl group, aralkyl group, or heterocyclic group. Is included. These groups may be the same or different from each other, and may be bridged between the two groups to form a ring containing a phosphorus atom.

As the phosphine, for example,
R ⁵ , R ⁶ , and R ⁷ in which all are aryl groups (triarylphosphine); and R ⁵ , R ⁶ , and R ⁷
One is an aryl group and one is another group,
One of R ⁵ , R ⁶ and R ⁷ is an aryl group;
Examples include those in which two are different groups, and those in which none of R ⁵ , R ⁶ , and R ⁷ is an aryl group. Among these phosphines, those in which all of R ⁵ , R ⁶ and R ⁷ are aryl groups are preferred.

Specific examples of the phosphine include the following compounds. Examples of the case where all of R ⁵ , R ⁶ and R ⁷ are aryl groups (triarylphosphine) include, for example, triphenylphosphine and tris (p
-Chlorophenyl) phosphine, tris (p-tolyl)
Phosphine and α-naphthyl (phenyl) -p-methoxyphenylphosphine.

As the phosphine dihalide represented by the general formula (C), R ⁸ , R ⁹ , and R ¹⁰ are R ¹ , R ² , R ³ ,
The same aryl group, alkyl group, aralkyl group or heterocyclic group as R ⁴ , wherein Y ¹ and Y ² are a halogen atom such as a chlorine atom, a bromine atom and an iodine atom. These groups may be the same or different from each other, and may be bridged between the two groups to form a ring containing a phosphorus atom. Also, Y ¹ and Y ² may be the same or different.

Examples of the phosphine dihalide include those in which all of R ⁸ , R ⁹ and R ¹⁰ are aryl groups (triarylphosphine dihalide), R ⁸ ,
Two of R ⁹ and R ¹⁰ are aryl groups and one is another group, or one of R ⁸ , R ⁹ and R ¹⁰ is an aryl group and two are different groups Or
Any of R ⁸ , R ⁹ , and R ¹⁰ is not an aryl group. Among these phosphine dihalides,
Preferably, all of R ⁸ , R ⁹ and R ¹⁰ are aryl groups.

Specific examples of the phosphine dihalide are as follows. Examples of the compound in which all of R ⁸ , R ⁹ and R ¹⁰ are an aryl group (triarylphosphine dihalide) include, for example, triphenylphosphine dichloride, triphenylphosphine dibromide,
Triphenylphosphine diiodide.

As the phosphine oxide represented by the general formula (D), R ¹¹ , R ¹² , and R ¹³ are R ¹ , R ² , R ³ ,
The same aryl group, alkyl group, aralkyl group or heterocyclic group as R ⁴ can be mentioned. These groups may be the same or different from each other, and may be bridged between the two groups to form a ring containing a phosphorus atom.

Examples of the phosphine oxide include those in which all of R ¹¹ , R ¹² and R ¹³ are aryl groups (triaryl phosphine oxide), R ¹¹ ,
One in which two of R ¹² and R ¹³ are aryl groups and one is another group, and one in which one of R ¹¹ , R ¹² and R ¹³ is an aryl group and two are Or
Any of R ¹¹ , R ¹² , and R ¹³ is not an aryl group. Among these phosphine oxides,
Preferably, all of R ¹¹ , R ¹² and R ¹³ are aryl groups.

Specific examples of the phosphine oxide include the following compounds in which the phosphorus atom of the phosphine is oxidized. Examples of the compound in which all of R ¹¹ , R ¹² and R ¹³ are aryl groups (triarylphosphine oxide) include triphenylphosphine oxide, tris (p-chlorophenyl) phosphine oxide, tris (p-tolyl) phosphine oxide,
α-naphthyl (phenyl) -p-methoxyphenylphosphine oxide.

Among the organic phosphonium salts used in the present invention, tetraarylphosphonium halides, tetraarylphosphonium hydrogendihalides, and triarylphosphine dihalides are preferred. Among them, tetraarylphosphonium chloride, tetraarylphosphonium hydrogendichloride, Triarylphosphine dichlorides are particularly preferred.

In the present invention, the decarbonylation reaction of the diaryl oxalate may be carried out while supplying the following inorganic and / or organic halogen compounds as required. Among inorganic or organic halogen compounds, chlorine compounds or bromine compounds are preferred, and among them, chlorine compounds are particularly preferred. As the organic phosphorus compound, when phosphine or phosphine oxide is used, when an organic phosphonium salt other than halide and hydrogendihalide is used, or when low-concentration phosphonium halide or phosphonium hydrogendihalide is used It is particularly preferable to supply a halogen compound.

Examples of the inorganic halogen compounds include phosphorus halides such as phosphorus trichloride, phosphorus pentachloride, phosphorus oxychloride, phosphorus tribromide, phosphorus pentabromide and phosphorus oxybromide, and thionyl chloride, sulfuryl chloride, Sulfur halides such as sulfur chloride and disulfur dichloride, hydrogen halides such as hydrogen chloride and hydrogen bromide, and simple halogens such as chlorine and bromine are used. Among these inorganic halogen compounds, the above-mentioned inorganic chlorine compounds are preferred.

As the organic halogen compound, for example, a structure in which a halogen atom is bonded to a saturated carbon (C-Ha)
l) or a structure in which a halogen atom is bonded to a carbonyl carbon (-CO-Hal) (where Hal is a chlorine atom,
Represents a halogen atom such as a bromine atom. ) Is suitably used. These structures are represented, for example, by the following general formulas (a) and (b).

[0037]

Embedded image (In the formula, Hal represents a halogen atom such as a chlorine atom or a bromine atom, and n represents an integer of 1 to 4.)

As such an organic halogen compound,
For example, the following compounds are specifically mentioned. Examples of the organic halogen compound having a structure in which a halogen atom is bonded to a saturated carbon represented by the general formula (a) include halogenated compounds such as chloroform, carbon tetrachloride, 1,2-dichloroethane, butyl chloride, and dodecyl chloride. Alkyl, benzyl chloride, benzotrichloride, triphenylmethyl chloride, aralkyl halides such as α-bromo-o-xylene, and β-chloropropionitrile, and halogen-substituted aliphatic nitriles such as γ-chlorobutyronitrile; And halogen-substituted aliphatic carboxylic acids such as chloroacetic acid, bromoacetic acid and chloropropionic acid.

Examples of the organic halogen compound having a structure in which a halogen atom is bonded to a carbonyl carbon represented by the general formula (b) include acetyl chloride, oxalyl chloride, propionyl chloride, stearoyl chloride, benzoyl chloride,
Examples thereof include acid halides such as 2-naphthalene carboxylic acid chloride and 2-thiophene carboxylic acid chloride, aryl halogenoglyoxylates such as phenyl chloroglyoxylate, and aryl halogenoformates such as phenyl chloroformate. Among these organic halogen compounds, the above-mentioned organic chlorine compounds in which the halogen atom is a chlorine atom are preferred.

In the present invention, in the decarbonylation reaction of diaryl oxalate, as described above, a reactor having a plurality of reaction zones in the liquid phase is used. In the reactor of the present invention, the number of reaction zones is not particularly limited, but is preferably 2 to 30, particularly 2 to 10, and more preferably 2 to 5. Examples of such a reactor include, for example,
As shown in FIGS. 1 and 3, a raw material supply line 1, a reaction zone 2 (2-1, 2-2, 2-3, 2-4, etc.), a reaction zone partition plate 3, a communication hole 5, a liquid phase portion A reaction apparatus including a withdrawal line 6, a gaseous-phase part withdrawal line 7, a reactor having a plurality of reaction zones in a liquid-phase part, and communicating with a gas-phase part is exemplified. Further, as shown in FIG. 2, the raw material supply line 1, the reaction zone 2 (2-1, 2-
2, 2-3, 2-4, etc.), a plurality of liquid-phase parts having at least one reaction zone, including a liquid-phase part inlet line 4, a liquid-phase part extraction line 6, a gas-phase part extraction line 7, and the like. (A multi-tank type reactor having a plurality of reaction zones having independent structures). 1
One reactor has at least one reaction zone (for example, 1 to 3, preferably 1), and the reaction zone may be the same as in FIGS. The reactor has a gas phase above the liquid phase. In this reactor, the number of all reaction zones is not particularly limited, but is preferably 2 to 30, particularly 2 to 10, and more preferably 2 to 5. As described above, as the reaction apparatus used in the present invention, a plurality of reaction zones have an independent structure, or the inside is divided into a plurality of reaction zones (liquid phases) by a reaction zone partition plate. Those having a structure in which the gas phase portions of each reaction zone communicate with each other are preferably used. In addition, a condenser is installed in the gas phase extraction line 7 (not shown).

In the reaction apparatus shown in FIGS. 1 and 3, the height of the reaction zone partition plate may be gradually reduced as shown in FIG. 1, or may be the same as shown in FIG. . In such a reactor, the partition plate has one or more communication holes at arbitrary positions, respectively, but in the former case, the partition plate may not have the communication hole. The reaction solution is
In the former case having no communication hole, each reaction zone is sequentially overflowed and led to the final reaction zone. In addition, as a method of dividing the reaction zone into a plurality, such as a method of inserting a perforated plate,
Any method can be used as long as it can approach the plug flow type by dividing the reaction zone. The liquid phase of each reaction zone may be forcibly stirred and mixed by a stirrer, pump circulation, gas injection, or the like, or by the generation of carbon monoxide accompanying the reaction, the flow or convection of the liquid phase. Stirring and mixing may be sufficient. Also, the reactor is
For example, it is heated by passing a heat medium through an outer jacket or the like.

In the present invention, by using these reactors, the raw material liquid (diaryl oxalate and, for example,
Dephosphorization catalyst containing an organic phosphorus compound and the above-mentioned halogen compound) is successively led to a continuous reaction zone,
The decarbonylation reaction is performed at a high reaction rate and a high selectivity, and a reaction liquid containing diaryl carbonate is continuously obtained through the liquid phase extraction line 6 from the final reaction zone. Then, carbon monoxide generated due to the decarbonylation reaction is continuously or intermittently extracted from the upper part (gas phase part) of the reactor through the gas phase part extraction line 7 and removed to the outside of the reaction system.

After the reaction, the diaryl carbonate is separated and purified from the reaction solution containing the diaryl carbonate extracted from the final reaction zone by distillation or the like. Decarbonylation catalyst (for example,
The distillation residue (including a small amount of diaryl carbonate and unreacted diaryl oxalate) containing the organic phosphorus compound) is passed through a raw material supply line after a required amount of diaryl oxalate, the organic phosphorus compound and the halogen compound are added. First
It is circulated to the reaction zone. In addition, low-boiling substances etc. accompanying the extracted carbon monoxide are removed by the condenser. The recovered carbon monoxide is used for producing dialkyl oxalate, which is a raw material of diaryl oxalate.

In the decarbonylation reaction of diaryl oxalate, a raw material liquid containing diaryl oxalate, a decarbonylation catalyst (for example, the above-mentioned organic phosphorus compound) and, if necessary, the above-mentioned halogen compound is supplied to the first reaction zone. , While sequentially leading the liquid phase portion of the first reaction zone to a continuous reaction zone. At this time, the reaction temperature is 100 to 4
50 ° C, especially 160-400 ° C, furthermore 180-350
C. is preferred. The reaction pressure is not particularly limited, and the reaction may be performed under any of pressurized, normal, and reduced pressure conditions. The organic phosphorus compound is present in an amount of 0.001 to 50 mol%, preferably 0.01 to 50 mol%, based on diaryl oxalate.
When the halogen compound is supplied, the molar ratio of the halogen compound to the organic phosphorus compound (halogen compound / organic phosphorus compound) is preferably 0.01 to 300, and more preferably 0.1 to 200 mol%. It is preferably added so as to be 1 to 100. The organic phosphorus compound may be used alone or in combination of two or more, and may be dissolved and / or suspended in the reaction solution.

A solvent is not particularly required for the above decarbonylation reaction, but if necessary, diphenyl ether, sulfolane, N-methylpyrrolidone, dimethylimidazolidone, 1,3-dimethyl-3,4,5,6-tetrahydro A solvent such as -2 (1H) -pyrimidinone can be used as appropriate. The material of the reactor is not particularly limited, and for example, a reactor made of glass or stainless steel (SUS) can be used. The material of the partition plate is not particularly limited as long as it is inert to the reaction.

[0046]

Next, the present invention will be described specifically with reference to examples and comparative examples. The conversion of the diaryl oxalate (the ratio of the consumed diaryl oxalate to the supplied diaryl oxalate) and the selectivity of the diaryl carbonate (the ratio of the generated diaryl carbonate to the consumed diaryl oxalate) are on a molar basis. Mol%), and the rate of formation of the diaryl carbonate was represented by the number of g of the diaryl carbonate produced per hour per 1 L of the volume of the liquid phase in the reaction zone.

Example 1 As shown in FIG. 1, the liquid phase portions of the three reaction zones were 37 mL, 36 mL, and 48 mL in order (total volume of the liquid phase portion: 121 mL) and had no communication holes. Using a reactor consisting of a reactor (made of glass) having
The decarbonylation reaction of diphenyl oxalate was performed under argon flow as follows. A raw material liquid (a solution of diphenyl oxalate containing 0.50 mol% of tetraphenylphosphonium chloride and 6400 ppm of chloroform based on diphenyl oxalate) was placed in a flask at 150 ° C.
And continuously supplied at 27 g / hr to the first reaction zone of the reactor placed in an oil bath at 270 ° C. Then, the liquid phase portion of the first reaction zone overflows from the partition plate and is successively led to the second reaction zone and the third reaction zone, and the reaction solution is continuously extracted from the third reaction zone and the reaction proceeds. Was continuously withdrawn from the upper part of the reactor. During the reaction, the raw material supply line, the liquid phase extraction line and the pump were kept at 150 ° C., and the liquid phase in each reaction zone was stirred. When the reaction reached a steady state, the reaction liquid extracted from the third reaction zone was analyzed by gas chromatography to find that the composition was 93.0% by weight of diphenyl carbonate and 6.1% by weight of diphenyl oxalate. The conversion of diphenyl oxalate was 94.6% and the selectivity for diphenyl carbonate was 99.1.
%, Diphenyl carbonate formation rate (STY) is 185 g / L
Hr. The reaction temperature was 25 in the first reaction zone.
0 ° C., 246 ° C. in the second reaction zone, 246 ° C. in the third reaction zone
° C.

Example 2 As shown in FIG. 2, a reactor (liquid phase section) in which three reactors (made of glass) each having a 70 mL internal volume equipped with a condenser (not shown) were connected via a conduit and a pump. Has a volume of 7
Using a reactor consisting of three reactors having one reaction zone of 0 mL), the decarbonylation reaction of diphenyl oxalate was carried out as follows under a flow of argon. A raw material solution (a solution of diphenyl oxalate containing 0.50 mol% of tetraphenylphosphonium chloride and 6500 ppm of chloroform based on diphenyl oxalate) was dissolved in a flask at 150 ° C., and 270 ° C.
3 in the first reaction zone (first reactor) in the oil bath
It was fed continuously at 4 g / hr. When the liquid phase in the first reaction zone reaches 50 mL, the second reaction zone (second
To the third reactor (third reactor) when the liquid phase in the second reactor reached 50 mL.
The reaction solution was continuously withdrawn from the third reaction zone, and carbon monoxide generated as the reaction proceeded was continuously withdrawn from the top of the reactor. The liquid phase of each reaction zone is 5
Adjust the volume of solution to be 0 mL (total volume of liquid phase: 1
(50 mL) and stirred. The temperature of the raw material supply line, the liquid phase extraction line and the pump was maintained at 150 ° C.
When the reaction reached a steady state, the reaction liquid extracted from the third reaction zone was analyzed by gas chromatography to find that the composition was 89.8% by weight of diphenyl carbonate and 9.6% by weight of diphenyl oxalate. , The conversion of diphenyl oxalate is 91.5% and the selectivity of diphenyl carbonate is 9
9.3%, diphenyl carbonate formation rate (STY) is 182
g / L · hr. The reaction temperature was 250 ° C. in all of the first to third reaction zones.

Comparative Example 1 A reactor as shown in FIG. 1 without a partition plate (made of glass) was used, and the volume of the liquid phase was 120 mL.
The reaction solution was analyzed by performing a decarbonylation reaction of diphenyl oxalate in the same manner as in Example 1 except that the solution was fed so as to be as follows. As a result, when the reaction reached a steady state, the composition of the reaction solution withdrawn from the reactor was 76.6% by weight of diphenyl carbonate and 23.1% by weight of diphenyl oxalate, and the conversion of diphenyl oxalate was The diphenyl carbonate selectivity was 79.4% and the diphenyl carbonate formation rate (STY) was 155 g / L · hr. In addition,
The reaction temperature was 250 ° C.

[0050]

According to the present invention, diaryl oxalate is
A diaryl carbonate can be continuously produced at a high reaction rate and a high selectivity by performing a decarbonylation reaction at a low reaction temperature which is industrially suitable in the presence of the above-mentioned organic phosphorus compound. According to the present invention, a diaryl carbonate useful as a raw material for a polycarbonate can be produced at a high reaction rate and a high selectivity without using phosgene which is a highly toxic compound. The present invention is a method for industrially continuously producing diaryl carbonate from diaryl oxalate, and is very useful.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a reaction apparatus used in Example 1.

FIG. 2 is a diagram schematically showing a reaction apparatus used in Example 2.

FIG. 3 is a diagram schematically showing an embodiment of the present invention.

[Explanation of symbols]

 1: Raw material supply line 2 (2-1, 2-2, 2-3, 2-4, etc.): Reaction zone 3: Reaction zone partition plate 4: Liquid phase part feed line 5: Communication hole 6: Liquid phase part Extraction line 7: Extraction line for gas phase

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Doi Ube Research Institute, Ube City, Yamaguchi Prefecture, 5th place, 1978 Kogushi, Ube Research Institute (72) Inventor Sadao Niida 578, Obe, Ube City, Yamaguchi Prefecture, 1978, 5th place, Kobe Ube, 5 Ube Industries Ube Research Institute Co., Ltd. (72) Inventor Toshio Kurato 5 Ube Kosan Co., Ltd. Ube Research Laboratory at 1978 Kogushi, Ube City, Yamaguchi Prefecture

Claims (12)

[Claims] In a first reaction zone of a reactor having a plurality of reaction zones, a diaryl oxalate and a phosphorus atom having a valence of trivalent or pentavalent and at least one carbon-phosphorus (C) are provided. -P) The organic phosphorus compound having a bond is continuously supplied in a liquid phase state, the liquid phase portion of the reaction zone is successively led to a continuous reaction zone, and a reaction liquid containing diaryl carbonate is continuously fed from the final reaction zone. A method for producing a diaryl carbonate, comprising performing a decarbonylation reaction of a diaryl oxalate while extracting the generated carbon monoxide from the upper part of the reaction zone while extracting the diaryl oxalate. 2. The carbonic acid reactor according to claim 1, wherein the reactor is a reactor comprising a reactor having a plurality of reaction zones in a liquid phase portion and communicating with a gas phase portion. Method for producing diaryl. 3. The method for producing a diaryl carbonate according to claim 1, wherein the reaction device is a reaction device comprising a plurality of reactors each having a liquid phase portion having at least one reaction zone. 4. The method for producing a diaryl carbonate according to claim 1, wherein the organic phosphorus compound is an organic phosphonium salt, phosphine, phosphine dihalide, or phosphine oxide. 5. The diaryl carbonate according to claim 1, wherein the organophosphorus compound is a tetraarylphosphonium salt, a triarylphosphine, a triarylphosphine dihalide or a triarylphosphine oxide. Production method. 6. The method for producing a diaryl carbonate according to claim 1, wherein the organic phosphorus compound is a tetraarylphosphonium halide or a tetraarylphosphonium hydrogendihalide. 7. The decarbonylation reaction is performed while supplying an organic halogen compound having a structure in which a halogen atom is bonded to a saturated carbon or a structure in which a halogen atom is bonded to a carbonyl carbon to the first reaction zone. The method for producing a diaryl carbonate according to claim 1, 2, or 3. 8. The decarbonylation reaction is performed while supplying at least one inorganic halogen compound selected from a halogen compound of phosphorus, a halogen compound of sulfur, a hydrogen halide and a simple halogen to the first reaction zone. The method for producing a diaryl carbonate according to claim 1, 2, or 3. 9. The method for producing a diaryl carbonate according to claim 7, wherein the halogen compound is a chlorine compound. 10. A diaryl oxalate and a decarbonylation catalyst are continuously supplied in a liquid phase state to a first reaction section of a reactor having a plurality of reaction sections in a liquid phase section, and the liquid phase section in the reaction section is supplied. The decarbonylation reaction of the diaryl oxalate is carried out by sequentially leading the reaction solution containing the diaryl carbonate from the final reaction zone and continuously extracting the generated carbon monoxide from the upper portion of the reaction zone by sequentially leading the reaction solution to the continuous reaction zone. A method for producing a diaryl carbonate. 11. The carbonic acid reactor according to claim 10, wherein the reactor is a reactor comprising a reactor having a plurality of reaction zones in a liquid phase portion and communicating with a gas phase portion. Method for producing diaryl. 12. The method for producing a diaryl carbonate according to claim 10, wherein the reactor is a reactor comprising a plurality of reactors each having a liquid phase portion having at least one reaction zone.