JPH04257546A - Continuous producition of aromatic carbonate - Google Patents

Abstract

PURPOSE:To continuously produce an aromatic carbonate, especially diphenyl carbonate, useful as a raw material for polycarbonates and isocyanate compounds in high yield and selectivity at a high reaction rate. CONSTITUTION:When an aromatic hydroxy compound is reacted with carbon monoxide and molecular oxygen in the presence of a catalyst to produce an aromatic carbonate, the aromatic hydroxy compound 2, and the carbon monoxide and molecular oxygen 7 are continuously fed into a continuous multi-step distillation tower 1 and brought into contact with a catalyst comprising a main catalyst and an auxiliary catalyst in the distillation tower 1 for their reaction. Water by-produced by the reaction is simultaneously continuously distilled out in a gaseous state from a line 12, and the produced aromatic carbonate 19 is continuously taken out from the lower part 18 of the column in high yield and selectivity.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing aromatic carbonates. More specifically, the present invention relates to a method for continuously and efficiently producing aromatic carbonates by reacting an aromatic hydroxyl compound with carbon monoxide and molecular oxygen.

0002

BACKGROUND OF THE INVENTION Aromatic carbonates have traditionally been prepared from the reaction of aromatic hydroxyl compounds with phosgene or chloroformic acid aryl esters in the presence of dehydrochlorinating agents. Chlorformic acid aryl esters are prepared from aromatic hydroxyl compounds and phosgene, so both methods require phosgene. However, since phosgene is extremely toxic and the equipment is highly corrosive, there is a demand for the development of a method for producing aromatic carbonates without using phosgene, and several attempts have been made. As a preferred method, a method has been proposed in which an aromatic hydroxyl compound is oxidatively carbonylated in the presence of carbon monoxide and an oxidizing agent.

For example, Japanese Patent Publication No. 56-38143 proposes reacting phenols with carbon monoxide and palladium compounds in the presence of a base, but this method is not a catalytic reaction, but a stoichiometric reaction. A stoichiometric amount of palladium compound is required. Japanese Patent Publication No. 56-38144 and Japanese Patent Publication No. 56-38145 have proposed a method for causing a palladium compound to act catalytically. These methods produce aromatic carbonates by reacting phenols with carbon monoxide and oxygen in the presence of a palladium catalyst. IIIA and IV of the periodic table are used as redox agents to convert zero-valent palladium into divalent palladium.
A, VA, VIA, IB, IIB, IVB and VII
It is essential to use a compound containing a group metal, and it is also essential to coexist with a base in addition to this. Japanese Patent Publication No. 56-38145 proposes adding a desiccant such as a molecular sieve as a method of improving this catalytic reaction, but the reaction system becomes increasingly complex. Furthermore, such technology is disclosed in Japanese Patent Application Laid-Open No. 53-67847 and Japanese Patent Application Laid-Open No. 54-135743.
No. 54-135744, Japanese Patent Application Laid-Open No. 1982-135744
It is also disclosed in JP-A-102539, JP-A-2-104564, and JP-A-2-142754.

[0004] The present inventor also carried out an oxidative carbonylation reaction of an aromatic hydroxyl compound in the presence of palladium, an iodine compound, and zeolites.
The first application was filed for the discovery that aromatic carbonates can be produced with high selectivity (Japanese Patent Application Laid-open No. 1-165551). The method of producing aromatic carbonates by oxidative carbonylation of aromatic hydroxy compounds requires a very difficult reaction to proceed, and all methods proposed so far have been based on the use of catalysts and additives. It was related to the development of

[0005]

[Problems to be Solved by the Invention] However, in all of these methods, the reaction rate is low, and
With the exception of the method disclosed in Japanese Patent No. 165551, the reaction rate was extremely slow and it was substantially difficult to implement it industrially. Further, the methods proposed so far are essentially batch methods in which an aromatic hydroxy compound and a catalyst are charged into a reactor and reacted with carbon monoxide and oxygen. Therefore, there has been no disclosure of a continuous reaction system in which an aromatic hydroxy compound is continuously supplied and the product aromatic carbonate is continuously extracted.

[0006]

[Means for Solving the Problems] The present inventor has solved the problem of producing aromatic carbonates continuously at a high reaction rate and with high selectivity without the drawbacks of the methods proposed so far. As a result of intensive research to develop a method, we found that when carrying out this reaction, an aromatic hydroxy compound is continuously supplied to a continuous multi-stage distillation column, and the reaction is carried out within the column, while at the same time water produced by the reaction is removed. The present inventors have discovered that the above object can be easily achieved using a reactive distillation column system in which the reaction system is continuously removed by distillation, and the present invention has been completed.

That is, the present invention involves reacting an aromatic hydroxy compound with carbon monoxide and molecular oxygen in the presence of a catalyst to produce an aromatic carbonate. While carbon monoxide and molecular oxygen are reacted by contacting with a catalyst system consisting of a main catalyst and a co-catalyst in a distillation column, the by-product water is continuously distilled in a gaseous state. This is a continuous method for producing aromatic carbonates, which is characterized by continuously extracting the produced aromatic carbonates in liquid form from the bottom of the column.

The aromatic hydroxyl compound used in the present invention may be any compound as long as it has a hydroxyl group directly bonded to an aromatic group. For example, phenol; cresol (each isomer),
Various alkylphenols such as xylenol (each isomer), trimethylphenol (each isomer), tetramethylphenol (each isomer), ethylphenol (each isomer), propylphenol (each isomer); methoxyphenol (each isomer); isomer), ethoxyphenol (each isomer)
Various alkoxyphenols such as; chlorphenol (each isomer), bromophenol (each isomer), dichlorophenol (each isomer), halogenated phenols such as dibromophenol, methylchlorophenol (each isomer), Alkyl and halogen-substituted phenols such as ethylchlorophenol (each isomer), methylbromophenol (each isomer), ethylbromophenol;

[0009]

[Chemical formula 1]

(However, A is a simple bond or -O-
, -S-, -CO-, -CO2-, -SO2-, and other divalent groups; alkylene groups or substituted alkylene groups represented by chemical formulas 2 and 3;

[0011]

[Case 2]

0012

[Chemical formula 3]

[0013] (Here, R5, R6, R7, R8
each independently represents a hydrogen atom, a lower alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group, and may be optionally substituted with a halogen atom or an alkoxy group). or 4

[0014]

[C4]

A cycloalkylene group such as [0015] (where K is 3
-11, the hydrogen atom may be substituted with a lower alkyl group, an aryl group, a halogen atom, etc.), and the aromatic ring is a lower alkyl group, a lower alkoxy group, an ester group, a hydroxyl group, etc. may be substituted with a substituent such as a group, a nitro group, a halogen group, or a cyano group. ) various substituted phenols; naphthol (
(Each isomer) and various substituted naphthols; Hydroxypyridine (Each isomer), Hydroxycoumarin (Each isomer)
, hydroxyquinoline (each isomer); Aromatic dihydroxy compounds such as hydroquinone, resorcinol, catechol, and their alkyl-substituted or halogen-substituted dihydroxy compounds;

[0016]

[C5]

(A is as described above, and may be substituted with a substituent such as an aromatic ring halogen, an alkyl group, an alkoxy group, an ester group, an amide group, or a cyano group.) aromatic dihydroxy compounds; polyhydric phenols such as pyrogallol and phloroglucin; and the like. Further, a group containing an aromatic hydroxyl group may form the main chain or side chain of the polymer. Aromatic carbonates are obtained from aromatic dihydroxy compounds.

Such an aromatic hydroxyl compound has 1
It is possible to use only the seeds or a mixture of two or more kinds. Among these, preferred aromatic hydroxyl compounds are aromatic monohydroxy compounds, and phenols and various substituted phenols are preferred. Particularly preferred is
This is a case where diphenyl carbonate is produced using phenol. Diphenyl carbonate is an industrially important material that is important as a raw material for producing polycarbonate by reacting with organic dihydroxy compounds, and can also be used as a raw material for producing the corresponding isocyanates by reacting with amines. This is because it is a chemical compound.

In the present invention, the catalyst is used as a catalyst system consisting of a main catalyst and a co-catalyst. As the main catalyst,
For example, at least one selected from platinum group metals and compounds containing platinum group metal elements can be used. Regarding platinum group metals and compounds containing platinum metal elements, there are no particular restrictions as long as they contain at least one element selected from platinum group elements such as palladium, rhodium, platinum, ruthenium, iridium, and osmium. Without,
These elements may be in a metallic state or may be components forming a compound. In addition, these catalyst components include, for example, activated carbon, graphite, silica, alumina, silica alumina, silica titania, titania, zirconia, silicon carbide, barium sulfate, calcium carbonate, asbestos, bentonite, diatomaceous earth, polymers, and ions. It may be supported on a carrier such as an exchange resin, zeolite, molecular sieve, magnesium silicate, or magnesia.

[0020] Examples of platinum group elements in the metallic state include metals such as palladium, rhodium, platinum, ruthenium, iridium, and osmium, their metal blacks, and catalyst components containing these metal ions on the carrier as described above. , those reduced with hydrogen, formaldehyde, hydrazine, etc., and alloys or intermetallic compounds containing these metals are used. Further, the alloy or intermetallic compound may be one of these platinum group metals, or may be one of these platinum group metals, or may contain other elements such as selenium, tellurium, sulfur, antimony, bismuth, copper, silver, gold, zinc, tin, vanadium,
It may contain iron, cobalt, nickel, mercury, lead, thallium, chromium, molybdenum, tungsten, etc.

On the other hand, as compounds containing platinum group elements,
For example, inorganic salts such as halides, sulfates, nitrates, phosphates, borates, organic acid salts such as acetates, oxalates, and formates, cyanides, hydroxides, and oxidants. sulfides, metal salts containing anions such as nitro groups, cyano groups, halogens, oxalate ions, and salts containing ammonia, amines, phosphines, carbon monoxide, chelate ligands, etc. Examples include metal complex compounds such as complexes, and organometallic compounds having an organic ligand or an organic group.

Among these main catalyst components, those containing palladium or rhodium or both are particularly preferable, such as Pd black; Pd-C;
, Pd-Al2O3, Pd-SiO2, Pd-T
iO2, Pd-ZrO2, Pd-BaSO4, P
Supported palladium catalysts such as d-CaCO3, Pd-asbestos, Pd-zeolite, Pd-molecular sieve; Pd-Pb, Pd-Se, Pd-Te, Pd-H
g, Pd-Tl, Pd-P, Pd-Cu, Pd-Ag,
Alloys or intermetallic compounds such as Pd-Fe, Pd-Co, Pd-Ni, Pd-Rh, and these alloys or intermetallic compounds supported on the above-mentioned carriers; PdCl2
, PdBr2, PdI2, Pd(NO3)2
, PdSO4; Pd(OCOCH3
)2, organic acid salts such as palladium oxalate; Pd(
CN)2;PdO;PdS;M2 [PdX4],
Palladate salts (M2) represented by [PdX6]
represents an alkali metal, ammonium ion, nitro group, or cyano group, and X represents a halogen); [Pd(NH
3)4 Ammine complexes of palladium such as [Pd(en)2]X2 (X has the same meaning as above and en represents ethylenediamine); PdCl2
(PhCN)2, PdCl2 (PR3)2, P
d(CO)(PR3)3, Pd(PPh3)4
, PdCl(R)(PPh3)2, Pd(C2H
4) (PPh3)2, Pd(C3H5)2
Complex compounds or organometallic compounds such as (R is an organic group,
Ph represents a phenyl group); complex compounds coordinated with a chelate ligand such as Pd(acae)2 (acac represents an acetylacetonate group); Rh black; supported rhodium catalysts similar to Pd); Rh alloys or intermetallic compounds similar to Pd, and those supported on a carrier; Rh
Cl3 and hydrate, RhBr3 and hydrate, RhI
3 and hydrates, inorganic salts such as Rh2 (SO4)3 and hydrates; Rh2 (OCOCH3)4, R
h2O3, RhO2, M3[RhX6] and hydrates (M and X have the same meanings as above); [Rh(NH
3) Rhodium ammine complexes such as 5]X3, [Rh(en)3]X3; Rh4 (CO)12
, Rh6 (CO)16 and other rhodium carbonyl clusters; [RhCl(CO)2 ]2 , RhCl3
(PR3)3, RhCl(PPh3)3, R
hX(CO)L2. (X has the same meaning as above, L
is a ligand consisting of an organic phosphorus compound and an organic arsenic compound), a complex compound such as RhH(CO)(PPh3)3, or an organic metal compound.

Furthermore, among these, those containing palladium are particularly preferably used as the main catalyst of the present invention. Examples of the co-catalyst of the present invention include alkali metal halides, alkaline earth metal halides, halogenated onium compounds, compounds capable of producing halogenated onium compounds in the reaction system, halogen oxoacids or salts thereof, and halogens. Examples include complex compounds containing halogens, and compounds containing halogens such as organic halides.

Furthermore, copper, zinc, mercury, thallium, tin, titanium, arsenic, antimony, bismuth, vanadium, chromium, molybdenum, tungsten, manganese, iron,
Metals such as cobalt, nickel, and cerium, compounds such as oxides, halides, nitrates, sulfates, and organic acid salts of these metals, and metal carbonyls in which carbon monoxide is coordinated with these metals: and these. Organometallic compounds containing these metals; complex compounds in which chelate ligands are coordinated to these metals; and compounds such as alkoxides and aryloxides of these metals can also be used as promoters.

Among these promoters, the halogen species are chlorine,
Compounds containing halogens such as bromine and iodine are preferably used, and compounds whose halogen species is iodine are particularly preferably used. Among these iodine-containing compounds, alkali metal iodides, alkaline earth metal iodides and onium iodide compounds are more preferably used.

Examples of such alkali metal iodides and alkaline earth metal iodides include lithium,
Iodides such as sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, and radium, specifically lithium iodide, sodium iodide, potassium iodide,
Compounds of iodine and a single metal such as rubidium iodide, cesium iodide, beryllium iodide, magnesium iodide, calcium iodide, strontium iodide, barium iodide, radium iodide; potassium iodine chloride, rubidium iodine chloride Iodine-containing polyhalogenated alkali metal compounds such as cesium iodine chloride, cesium iodine chloride bromide, potassium iodine bromide, cesium iodine bromide, and rubidium iodine bromide are preferably used.

An onium iodide compound is a compound containing an element with a lone pair of electrons, in which a reagent in the form of a proton or other cation binds to these lone pairs, so that the element with a lone pair of electrons becomes a shared atom. It has an increased valence of 1 to become a cation, and has an iodine anion as a counter ion. Examples of such onium iodide compounds include ammonium iodide compounds ([R1 R
2 R3 R4 N+ ]I- ), phosphonium iodide compound ([R1 R2 R3 R4 P+ ]I-
), arsonium iodide compound ([R1 R2 R3
R4 As+ ]I-), stibonium iodide compound ([R1 R2 R3 R4 Sb+]I-), oxonium iodide compound ([R1 R2 R3 O+
]I-), sulfonium iodide compound ([R1 R2
R3S+]I-), oxysulfonium iodide compound ([R1R2R3S+ (O)]I-),
Selenoium iodide compound ([R1 R2 R3 Se
+]I-), telluronium iodide compound ([R1
R2 R3 Te+ ]I-), stannonium iodide compound ([R1 R2 R3 Sn+]I-),
Iodinium iodide compound ([R1 R2 I+]I
− ), etc. Here, R1, R2, R
3, R4 represents hydrogen or a group selected from an aliphatic group, an aromatic group, an alicyclic group, and an araliphatic group, and each may be the same, and in some cases, a lone pair of electrons may be present. It may be a constituent element of a ring containing an element having Of course, it may be a compound having two or more such onium groups in its molecule, or it may be a polymer containing such onium groups in its main chain or side chain.

Such onium iodide compounds include hydrogen iodide or organic iodine compounds, and corresponding amino compounds (including ammonia) or nitrogen-containing compounds, phosphine compounds, arsine compounds, stibine compounds, oxy compounds, sulfide compounds, It is easily obtained by reaction with sulfoxide compounds, selenide compounds, telluride compounds, etc., and these may be produced outside the reaction system or may be produced within the reaction system. Of course, it may be produced by other methods, or may be produced within the reaction system by other methods.

Among these, preferred are ammonium iodide compounds, phosphonium iodide compounds, arsonium iodide compounds and sulfonium iodide compounds, and particularly preferred are ammonium iodide compounds and phosphonium iodide compounds. Ammonium iodide compounds can be easily obtained by reacting a corresponding nitrogen-containing compound with hydrogen iodide, or by reacting a nitrogen-containing compound with an organic iodine compound such as alkyl iodide or aryl iodide. Examples of nitrogen-containing compounds include ammonia, amines such as primary amines, secondary amines, and tertiary amines, hydroxylamines, hydrazines, hydrazones, amino acids, oximes, imidoesters, and amides. and various nitrogen-containing heterocyclic compounds. Preferred hydrogen iodide salts of nitrogen-containing compounds include ammonium iodide which is a salt with ammonia, salts of aromatic amines such as aniline, diphenylamine, and triphenylamine, methylamine, ethylamine, hexylamine, octylamine, and dimethylamine. , trimethylamine, diethylamine, triethylamine, dibutylamine, tripropylamine, methylethylamine,
Salts of aliphatic amines such as dimethylethylamine, dibutylmethylamine, tributylamine, ethylenediamine, hexamethylenediamine, salts of aliphatic amines such as cyclopropylamine, cyclohexylamine, N-methylcyclohexylamine, benzylamine, N-methylbenzyl amines, salts of aromatic aliphatic amines such as N,N-diethylbenzylamine and dibenzylamine, piperidine, piperazine, morpholine, pyridine, quinoline, hexamethylenetetramine, oxazole, thiazole,
Salts of nitrogen-containing heterocyclic compounds such as imidazole, triazole, benzotriazole, and diazabicycloundecene, and salts of amides such as dimethylacetamide and N-methylpyrrolidone are used.

[0030] Examples of quaternary ammonium iodide compounds include aliphatic iodides such as tetramethylammonium iodide, tetraethylammonium iodide, tetrabutylammonium iodide, trimethylethylammonium iodide, and diethyldibutylammonium iodide. Quaternary ammonium compounds, alicyclic quaternary ammonium compounds such as N,N,N-trimethylcyclohexylammonium iodide, and aromatic aliphatic compounds such as tetrabenzylammonium iodide and trimethylbenzylammonium iodide. Quaternary ammonium iodide compounds, N iodide,
N,N-trimethylphenylammonium, N iodide,
Aromatic quaternary ammonium iodide compounds such as N,N-triethylphenylammonium, N-methylpyridium iodide, N-ethylquinolinium iodide, N-iodide
, N-dimethylpiperidinium, N,N'-dimethylimidazolium iodide, and other heterocyclic quaternary ammonium iodide compounds are preferably used.

Examples of polymers containing an ammonium iodide group in the main chain or side chain include compounds 6 to 8.
Those having main structural units as shown in are preferably used.

[0032]

[C6]

[0033]

[C7]

[0034]

[Chemical formula 8]

[0035] Here, R1, R2, and R3 have the above-mentioned meanings, and R3 represents a divalent organic group. Examples of phosphonium iodide compounds include symmetrical tetraalkylphosphonium iodide compounds such as tetramethylphosphonium iodide, tetraethylphosphonium iodide, and tetrabutylphosphonium iodide, ethyltrimethylphosphonium iodide, diethyldimethylphosphonium iodide, and the like. asymmetrical tetraalkylphosphonium iodide compounds such as asymmetrical diethyldimethylphosphonium iodide; symmetrical tetraarylphosphonium iodide compounds such as tetraphenylphosphonium iodide and tetra(p-tolyl)phosphonium iodide; , asymmetrical tetraarylphosphonium iodide compounds such as (α-naphthyl)triphenylphosphonium iodide, alkylaryl mixed phosphonium iodide compounds such as methyltriphenylphosphonium iodide, phenyltrimethylphosphonium iodide, Tetraaralkylphosphonium iodide compounds such as tetrabenzylphosphonium iodide are preferably used.

Examples of the arsonium iodide compound include symmetrical tetraalkylarsonium iodide compounds such as tetramethylarsonium iodide and tetraethylarsonium iodide, methyltriethylarsonium iodide, and dimethyldiethylarsonium iodide. Asymmetrical tetraalkylarsonium iodide compounds such as Ni, symmetrical tetraarylarsonium iodide compounds such as tetraphenylarsonium iodide, methyltriphenylarsonium iodide, ethyltriphenylarsonium iodide Alkylaryl mixed arsonium iodide compounds such as phenyltrimethylarsonium iodide and phenyltrimethylarsonium iodide are preferably used.

Examples of the sulfonium iodide compounds include symmetrical or asymmetrical alkylsulfonium iodide compounds such as trimethylsulfonium iodide, triethylsulfonium iodide, and methyldiethylsulfonium iodide, triphenylsulfonium iodide, etc. Aryl sulfonium iodide compounds, alkylaryl sulfonium iodide compounds such as dimethyl phenyl sulfonium iodide, methyl diphenyl sulfonium iodide,
Cyclic sulfonium compounds such as bicyclo-(2,2,1)-heptane-1-sulfonium iodide and thiopyrylium iodide are preferably used.

[0038] Polymers containing a phosphonium iodide group or a sulfonium iodide group in the main chain or side chain are also preferably used, and such polymers include, for example, those having a main structural unit as shown in formula 9. can be given.

[0039]

[Chemical formula 9]

(In the formula, R1, R2, and R3 have the above-mentioned meanings.) These cocatalysts can be used alone or in combination of two or more. In the present invention, when using a solid catalyst, for example, a mixture of a solid main catalyst and a co-catalyst, a solid main catalyst supporting a co-catalyst component, a solid co-catalyst supporting a co-catalyst component, etc. Those that support a catalyst component, those that co-support a main catalyst component and a co-catalyst component on a common carrier, etc. are used.

[0041] The continuous multi-stage distillation column used in the present invention is:
Any type of distillation column may be used as long as it has multiple theoretical stages of distillation of two or more and is capable of continuous distillation. As such a continuous multi-stage distillation column,
For example, tray tower systems using trays such as bubble bell trays, perforated plate trays, valve trays, and countercurrent trays, Raschig rings, Lessing rings, Pall rings, Berle saddles, Interlocks saddles, Dixon packing,
Any type of column that is normally used as a continuous multi-stage distillation column can be used, such as a packed column type packed with various types of packing such as McMahon packing, Helipak, Sulzer packing, Merapak, etc. (The number of plates in a distillation column in the present invention means, in the case of a plate column,
It represents the number of plates, and for packed column type and other distillation columns, it represents the number of theoretical plates. ) Furthermore, a tray-packed mixing column system having both a tray section and a section filled with packing materials is also preferably used. Furthermore, when a solid catalyst insoluble in the liquid phase within the distillation column is used, a packed column type distillation column in which the solid catalyst is filled in place of part or all of the packing is also preferably used.

In the present invention, it is essential to have a catalyst system consisting of a main catalyst and a co-catalyst in the continuous multi-stage distillation column, and more preferably the catalyst is present in two or more stages in the continuous multi-stage distillation column. It is to make it exist. Any method may be used to provide a catalyst system consisting of a main catalyst and a co-catalyst in such a continuous multi-stage distillation column.

For example, if both the main catalyst and the co-catalyst are soluble in the liquid phase in the distillation column, the catalyst system can be added to the reaction system by continuously feeding the main catalyst and the co-catalyst into the distillation column. Alternatively, if either the main catalyst or the co-catalyst is insoluble in the liquid phase in the distillation column, the insoluble one is placed in the distillation column and the soluble one is placed in the distillation column. The catalyst can be present in the reaction system by continuous feeding, or if both the main catalyst and co-catalyst are insoluble in the liquid phase in the distillation column, they can be placed in the distillation column. By doing so, a catalyst can be present in the reaction system, and a method using these in combination may also be used.

When the main catalyst and/or co-catalyst that is soluble in the liquid phase in the continuous multi-stage distillation column is continuously supplied into the distillation column, it is mixed with the aromatic hydroxy compound as the raw material and simultaneously supplied with the raw material. It may be supplied, or it may be supplied to a stage different from the raw material supply position. Further, the catalyst may be supplied to any position as long as it has at least one stage from the bottom of the column.

Furthermore, if at least one of the main catalyst and co-catalyst is insoluble in the liquid phase within the distillation column, the insoluble solid main catalyst and/or co-catalyst may be placed at a required position within the distillation column. The required amount can be filled, and the number of theoretical plates in the bed in which this catalyst is present may be at least one or more, preferably at least two or more. This solid catalyst also has the effect of filling the distillation column.

[0046] Furthermore, in the region of the distillation column where no catalyst is present, it only functions as a normal distillation column, such as concentrating reaction products. The molecular oxygen used in the present invention is pure oxygen or a substance containing oxygen, and may be air or other gases that do not inhibit the reaction of air or pure oxygen, such as nitrogen, argon, helium, carbon dioxide gas, etc. It may be diluted with an inert gas such as Also,
In some cases, it may contain gases such as hydrogen, carbon monoxide, hydrocarbons, and halogenated hydrocarbons.

[0047] The carbon monoxide may also be highly pure carbon monoxide, or it may be diluted with other gases that do not adversely affect the reaction, such as nitrogen, argon, helium, carbon dioxide, hydrocarbons, or halogenated hydrocarbons. It may be something. Carbon monoxide is used at a partial pressure of 0.1 to 300 kg/cm2, preferably 1 to 200 kg/cm2. An example of the reaction of the present invention in the case of an aromatic monohydroxy compound is represented by the following formula.

[0048]

[Chemical formula 10]

(Ar represents an aromatic group) In the method of the present invention, an aromatic hydroxy compound is continuously fed into a continuous multi-stage distillation column, and a catalyst system consisting of a main catalyst and a co-catalyst is reacted in the distillation column. At the same time, the reaction shown in Chemical Formula 10 is carried out by contacting carbon monoxide and molecular oxygen in the presence of carbon monoxide and molecular oxygen, and at the same time, by-product water is continuously extracted in gaseous form from the distillation column by distillation.

[0050] This method is characterized in that aromatic carbonate is continuously produced by continuously extracting aromatic carbonate in liquid form from the bottom of the column. There are no particular limitations on the method for continuously supplying aromatic hydroxy compounds to a continuous multi-stage distillation column. Any supply method may be used as long as it allows oxygen to be brought into contact with a catalyst system consisting of a main catalyst and a co-catalyst. For example, the aromatic hydroxy compound can be continuously fed into the required stages through the required number of inlets. The aromatic hydroxy compound is supplied continuously as a liquid, gas, or a mixture of liquid and gas.

[0051] Carbon monoxide and molecular oxygen are each normally supplied into the distillation column in gaseous form. It is preferable to supply carbon monoxide and molecular oxygen continuously, but as long as they are within the predetermined pressure range required for the reaction, the supply is stopped and if the reaction causes their pressure to drop below the pressure required for the reaction. An intermittent supply method can also be adopted. Any method may be used to supply carbon monoxide and molecular oxygen to the distillation column, and the carbon monoxide and molecular oxygen are introduced through the required number of inlets provided at required positions in the distillation column. Carbon monoxide and molecular oxygen may be supplied from separate inlets, or a mixture may be supplied. Preferably, carbon monoxide and molecular oxygen are each continuously supplied in gaseous form into the distillation column from the bottom of the distillation column.

In the method of the present invention, water as a by-product is continuously extracted in gaseous form from a continuous multi-stage distillation column. in this case,
The gaseous extract may be water alone, a mixture with aromatic hydroxy compounds, carbon monoxide, molecular oxygen, etc., and in some cases aromatic carbon, which is a high boiling point product. - May contain small amounts of bonate. Other low boiling by-products may be included if present.

[0053] The outlet for extracting gaseous substances containing by-product water from the continuous multi-stage distillation column can be provided at an appropriate position other than the bottom of the column, but the concentration of water in the vapor phase is usually It increases towards the top. Therefore, it is preferable that the outlet for the gaseous substance be provided above the supply position of the aromatic hydroxy compound as the raw material.
It should be provided between the supply position and the top of the column or at the top of the column, and is particularly preferably provided at the top of the column.

The gaseous components thus extracted may be liquefied by cooling or the like, and a portion thereof may be returned to the upper part of the distillation column, a so-called reflux operation. When the reflux ratio is increased by this reflux operation, the efficiency of distilling the by-product water into the vapor phase increases, so that the concentration of water in the extracted gas component can be increased. However, increasing the reflux ratio too much increases the required thermal energy, which is not preferable. Therefore, the reflux ratio is usually 0 to 20, preferably 0 to 10.

Aromatic carbonate, which is the target product produced by the method of the present invention, is continuously extracted in liquid form from the bottom of the continuous multi-stage distillation column as a high-boiling product. In this case, the liquid extract may be an aromatic carbonate alone or a mixture with an aromatic hydroxy compound. Moreover, a small amount of by-product water may be included. If a high-boiling catalyst is used that can be dissolved in the liquid phase, the liquid effluent also contains the catalyst. An outlet for extracting a liquid substance containing aromatic carbonate, which is the target product, from the continuous multi-stage distillation column is provided at the bottom of the column, particularly preferably at the bottom of the column. A portion of the liquid substance thus extracted may be returned to the lower part of the distillation column in the form of a gas or a gas-liquid mixture by heating a portion thereof in a reboiler.

It is generally known that in a reaction in which two or more products are produced by an equilibrium reaction, the reaction proceeds by removing at least one of the products from the reaction system. However, the reaction of the present invention is not an equilibrium reaction, as represented by reaction formula (1), for example. Therefore, the method of the present invention, in which the reaction is carried out in a continuous multi-stage distillation column, and the water produced by the reaction is continuously extracted from the reaction system by distillation, is highly selective for aromatic carbonates. It was completely unexpected that this method could be produced with high efficiency, high yield, and rapid reaction rate. Furthermore, one feature of the method of the present invention is that it has a high selectivity to aromatic carbonates based on carbon monoxide.

The amount of the main catalyst used in the present invention depends on the type of main catalyst used, the type and amount of co-catalyst used, the type of continuous multistage distillation column, the type of aromatic hydroxy compound, reaction temperature, reaction pressure, etc. It also varies depending on the reaction conditions. When the main catalyst is continuously supplied to the reaction zone of a continuous multi-stage distillation column, it is usually preferably used in an amount of 0.0001 to 50% by weight based on the aromatic hydroxy compound as the feedstock. Further, in the case of a solid distillation column in which the main catalyst is insoluble in the liquid phase within the distillation column, a catalyst amount of 0.001 to 75% by volume based on the empty column volume of the distillation column is preferably used. Further, the amount of the co-catalyst is usually 0.01 to 1000 times the amount of the metal component of the main catalyst, preferably 0.1
It is used in a range of up to 100 times the molar amount.

In carrying out the present invention, a basic substance may be present in the reaction system if necessary for the purpose of improving the yield and/or selectivity of aromatic carbonate. Such basic substances may be either inorganic or organic, and include, for example, oxides and hydroxides of alkali metals and alkaline earth metals, sodium carbonate, sodium hydrogen carbonate, and carbonate. Potassium, potassium bicarbonate, barium carbonate, sodium silicate, magnesium silicate, potassium aluminate, calcium aluminate,
Salts of strong bases and weak acids such as sodium borate and barium borate, carbides such as calcium carbide and cesium carbide, and aluminum group metals such as aluminum hydroxide, potassium hydroxide, indium hydroxide, thallium hydroxide, and thallium oxide. Hydroxides and oxides, oxides and hydroxides of rare earth elements such as lanthanum oxide, cerium oxide, cerium hydroxide, quaternary ammonium hydroxide compounds, quaternary phosphonium hydroxide compounds, hydroxide Tertiary sulfonium compounds, sodium acetate, potassium benzoate,
Salts of strong bases and weak organic acids such as rubidium oxalate and barium propionate, alcoholates of alkali metals and alkaline earth metals such as sodium methylate, sodium ethylate, and calcium ethylate, sodium phenolate, and potassium phenolate. , alkali metal and alkaline earth metal phenolates such as magnesium phenolate, alkali metal and alkaline earth metal amides such as lithium amide, sodium amide, calcium amide, lithium dimethylamide, trimethylamine, triethylamine, tri-n-butylamine. , triphenylamine, diethylmethylamine, N,N
-diethylaniline, N-methylpiperidine, N,N'
-diethylpiperazine, N-methylmorpholine, triethylenediamine, hexamethylenetetramine, N,N,
N',N'-tetramethylethylenediamine, dicyclohexylethylamine, 1,2,2,6,6-pentamethylpiperidine, pyridine, quinoline, phenanthroline, indole, N-methylimidazole, 1,8-diazabicyclo[5,4, 0]-Undesen-7 (DB
U), tertiary amines and cyclic nitrogen-containing compounds such as 1,5-diazabicyclo[4,3,0]-nonene-5 (DBN), (but not having an N-H group), crown Crown compounds such as ether, aza crown ether, thia crown ether, aza crown, and complexes of these crown compounds with alkali metals, alkaline earth metal ions, etc. are used. Furthermore, there may be two or more of these groups exhibiting basicity in the molecule, or even if they form part of a polymer such as an anion exchange resin having a quaternary ammonium hydroxide group. good. Further, these basic substances or groups having basicity may be supported on a solid or chemically bonded.

In the present invention, the reaction takes place in a continuous multi-stage distillation column in which a catalyst system consisting of a main catalyst and a co-catalyst is present, but the reaction time varies depending on other reaction conditions, the type of continuous multi-stage distillation column, and the interior of the continuous multi-stage distillation column. Although it varies depending on the structure (for example, the types of shelves and packing materials), the time is usually 0.001 to 50 hours, preferably 0.01 to 10 hours, and more preferably 0.05 to 2 hours.

[0060] Compared to the prior art method found in the above-mentioned patent publication, which requires a long reaction time of 40 to 200 hours, the method of the present invention has a high space-time yield. There is one. The reaction temperature is the temperature within the continuous multi-stage distillation column, and although it varies depending on the type of aromatic hydroxy compound used, the reaction temperature is usually 50 to 350°C, preferably 80 to 280°C. The reaction pressure varies depending on the type of aromatic hydroxy compound used, reaction temperature, and other reaction conditions, but it may be reduced pressure, normal pressure, or increased pressure, and is usually 1 mmHg to 350 kg/c.
It is carried out in the range of m2.

In the present invention, it is not necessary to use a solvent or a diluent, but an organic compound that does not adversely affect the reaction can also be used as a solvent or diluent. Examples of such organic compounds include benzene,
Aromatic hydrocarbons such as toluene, xylene, mesitylene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, trichlorobenzene, fluorobenzene, chlorotoluene, chlornaphthalene, promnaphthalene; chlorhexane, chlorocyclohexane, Halogenated aliphatic hydrocarbons or halogenated alicyclic hydrocarbons such as trichlorotrifluoroethane, methylene chloride, chloroform, and carbon tetrachloride; Nitriles such as acetonitrile and benzonitrile; Sulfones such as sulfolane, methylsulfolane, and dimethylsulfolane ethers such as tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, anisole; acetone,
Ketones such as methyl ethyl ketone and acetophenone;
Esters such as ethyl acetate and ethyl benzoate; N, N
Examples include amides such as -dimethylformamide, N,N-dimethylacetomide, N-methylpyrrolidone, and hexamethylphosphoramide.

[0062]

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

[0063]

[Example 1] From the top of a continuous multistage distillation column consisting of a packed column with a height of 4 m and an inner diameter of 2.5 cm, packed with stainless steel Dixon packing (about 3 mm in diameter) as shown in Figure 1. To the position of 0.5 m, phenol,
A mixture consisting of Pd(acac)2 and tetrabutylammonium iodide is heated to 175 to 180°C from an inlet pipe (2) through a preheater (5) and then into a distillation column (1).
It was continuously supplied in liquid form at 200 g/hr (acac represents an acetylacetonate group). The composition of this mixture is 91.3% by weight of phenol, Pd(acac)
2 1.5% by weight, tetrabutylammonium iodide 7
．． It was 2% by weight. In addition, there is a jacket on the outside of the continuous multi-stage distillation column, and this jacket has a temperature of 175 to 180℃.
The distillation column was kept warm by circulating heat transfer oil.

A mixed gas consisting of 75% by volume of carbon monoxide and 25% by volume of air is heated to 200 to 205°C from the inlet pipe (7) through the preheater (9), and then transferred to the lower part of the distillation column (1). It was continuously introduced into the distillation column at a flow rate of 10 Nl/min. The pressure inside the continuous multi-stage distillation column is 30 kg/cm2
was maintained. The gaseous components continuously extracted from the tower top (17) are passed through the condenser (13), and the condensable components therein are condensed and then separated into a liquid phase in the gas-liquid separator (14). Separated into gas phase. The condensed liquid component, consisting mainly of water and phenol, is continuously withdrawn through conduit (15) and transferred to the non-condensable gaseous component through conduit (16).
were continuously extracted from. Further, a liquid substance mainly consisting of diphenyl carbonate and phenol catalyst was continuously extracted from the bottom (18) of the column via a conduit (19). It was found that diphenyl carbonate was being produced at a rate of 35.0 g/hr when the reaction and distillation reached a steady state. Considering that the average residence time in the reaction zone in the continuous multi-stage distillation column is 15 minutes, the reaction rate to diphenyl carbonate per unit time per unit volume of phenol supplied is 39.5%/unit time. It was l・hr. Further, the selectivity of diphenyl carbonate based on phenol was 99%, and the selectivity based on carbon monoxide was 92%. The amount of water in the condensate that was continuously drawn out from the conduit (15) was 2.8 g/hr.

[0065]

[Comparative Example 1] Phenol with the same composition as that used in Example 1 in an autoclave with an internal volume of 2 liters, Pd(acac)2
, mixture 2 consisting of tetrabutylammonium iodide
00g, and the system was filled with 75% carbon monoxide and 25% air by volume.
After replacing the inside of the system with a mixed gas consisting of % by volume, the system was heated with stirring so that the internal temperature was 175 to 180°C. The reaction pressure was set to 3.
1 while stirring to maintain 0 kg/cm2.
It was made to react at 75-180 degreeC for 4 hours. Analysis of the reaction solution revealed that 4.8 g of diphenyl carbonate was produced. This corresponded to a yield of 2.3% based on the phenol used, and the selectivity was 85%. Further, the selectivity of diphenyl carbonate based on carbon monoxide was 72%. In addition, the reaction rate of the used phenol to diphenyl carbonate per unit volume of reaction solution and per unit time is approximately 2
．． It was 9%/l·hr.

[0066]

[Example 2] The main catalyst is Pd/S;C, which has 0.1% by weight of palladium supported on silicon carbide with a diameter of about 3 mm, and the main catalyst and stainless steel Dixon packing (about 3 mm in diameter) have a capacity of about 1 The mixture was mixed in a ratio of 1 to 1, and this mixture was packed into an apparatus similar to that used in Example 1, which was used as a continuous multi-stage distillation column. Using a mixture consisting of 95% by weight of phenol and 5% by weight of tetrabutylammonium iodide, the reaction temperature was 150-155°C and the reaction pressure was 50% by weight.
kg/cm2, carbon monoxide (75% by volume) and air (2
Reaction and distillation were carried out continuously in the same manner as in Example 1 except that the flow rate was 30 Nl/min (5% by volume) and 30 Nl/min. After steady state, 31.2 g of diphenyl carbonate
/hr. The reaction rate of the supplied phenol to diphenyl carbonate per unit volume and per unit time in the reaction zone in the continuous multi-stage distillation column was 32%/l·hr. In addition, the selectivity of diphenyl carbonate based on phenol is 99%, and the selectivity based on carbon monoxide is 99%.
It was 0%. Furthermore, analysis of the condensate obtained by condensing gaseous substances continuously extracted from the upper part of the distillation column revealed that water was extracted at a rate of 2.4 g/hr.

[0067]

[Embodiment 3] Thirty stages of seats are installed inside as shown in Figure 2.
A continuous multi-stage distillation column consisting of a plate column with a height of 3 m and an inner diameter of 5 cm equipped with a butley tray was placed at a position 0.4 m from the top of the column, consisting of 93% by weight of phenol, 1% by weight of PdCl2 (PhCN)2, and 6% by weight of NaI. Introducing the mixture into the tube (2)
After passing through a preheater (5) and being heated to 180° C., it was continuously fed into the distillation column (1) at a rate of 350 g/hr. A portion of the bottoms was heated in a reboiler (10) at 200° C. and then recycled to the bottom of the distillation column via a conduit (11). Further, a gas consisting of 70% by volume of carbon monoxide and 30% by volume of air is passed through the preheater (9) from the inlet pipe (7) to 210% by volume.
After being heated to .degree. C., it was continuously introduced into the distillation column from the bottom (18) of the distillation column at a flow rate of 30 Nl/min. The pressure inside the continuous multi-stage distillation column was maintained at 50 kg/cm2. The gaseous components continuously extracted from the top (17) were separated into condensable components and non-condensable components in the same manner as in Example 1. The bottom component was continuously withdrawn from the bottom (18) via a conduit (19). This column bottom component contains 50.2g of diphenyl carbonate.
/hr was found to be generated. In addition, the conduit (1
The amount of water in the condensate continuously extracted from 5) is 4.
It was 28g/hr.

[0068]

Example 4 Diparatricarbonate could be continuously obtained at 30 g/hr in the same manner as in Example 1 except that paracresol was used instead of phenol. The selectivity of the supplied para-cresol standard was 97%.

[0069]

Example 5 Diparamethoxyphenyl carbonate could be continuously obtained at 53 g/hr in the same manner as in Example 3 except that paramethoxyphenol was used instead of phenol. The selectivity based on the supplied paramethoxyphenol was 96%.

[0070]

[Example 6] Rh(ac
Diphenyl carbonate was continuously obtained at 9.2 g/hr by the same method as in Example 1 except that ac)3 was used.

[0071]

Effects of the Invention According to the method of the present invention, aromatic carbonates can be obtained continuously in high yield and high selectivity using aromatic hydroxy compounds, carbon monoxide, and molecular oxygen as raw materials.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an example process for implementing the invention.

FIG. 2 is a schematic diagram of another example process for implementing the invention.

[Explanation of symbols]

1 Continuous multi-stage distillation column 2, 7, 11 Introductory pipe 5, 9 Preheater 10 Reboiler 8, 12, 15, 16, 19 Conduit 13 Condenser 14 Gas-liquid separator 17 Tower top 18 Bottom of the tower

Claims (1)

[Claims] Claim 1: In producing an aromatic carbonate by reacting an aromatic hydroxy compound with carbon monoxide and molecular oxygen in the presence of a catalyst, the aromatic hydroxy compound is continuously fed into a continuous multi-stage distillation column. Carbon monoxide and molecular oxygen are brought into contact with a catalyst consisting of a main catalyst and a co-catalyst in a distillation column to react, while by-product water is continuously extracted in gaseous form by distillation, producing an aromatic aroma. A continuous method for producing aromatic carbonates characterized by continuously extracting group carbonates in liquid form from the bottom of the column.