JP2000103747A - Production of liquid organic fluoride and apparatus for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means for efficiently producing a desired fluoride, especially a perfluoro compound in high yield by fluorinating a partially fluorinated organic compound and to provide a reactional apparatus therefor. SOLUTION: A fluorine-containing gas is fed from the bottom of a reactional apparatus having a structure in which a tank-shaped reactional zone is connected to the top of a columnar reactional zone so that gas and liquid flow can be carried out and the internal pressure of the tank-shaped reactional zone is weighted to the internal pressure of the columnar reactional zone and the ratio (V2/V1) of the internal volume (V2) of the tank-shaped reactional zone to the internal volume (V1) of the columnar reactional zone has a relationship of 0.2-2. A liquid organic compound having carbon-hydrogen bonds is fed to the tank-shaped reactional zone at the top and the liquid is kept in a uniformly mixed state in the tank-shaped reactional zone. The liquid flowing down to the columnar reactional zone flows down as a piston flow in the column while being brought into contact with the fluorine-containing gas and then discharged from the bottom of the columnar reactional zone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a fluorinated liquid organic compound and an apparatus used for the method. Preferably, the invention relates to a method and an apparatus for producing a perfluoro compound.

[0002]

2. Description of the Related Art Conventionally, fluorination of an organic compound, that is, a reaction of replacing an atom such as hydrogen or chlorine bonded to carbon with a fluorine atom or a reaction of adding a fluorine atom to an unsaturated bond between carbon atoms has been used. Various methods for producing fluorinated organic compounds are known. These are roughly classified into direct fluorination with fluorine gas, fluorination with high valent metal fluoride, and electrolytic fluorination.

[0003] Of these, direct fluorination using fluorine gas is a violent exothermic reaction and involves not only substitution or addition of fluorine but also cleavage of carbon-carbon bonds. In order to suppress these side reactions, the reaction heat is quickly removed,
It is necessary to control the reaction, and attempts have been made to conduct the reaction at a low temperature or to use an inert diluent, but no sufficient effect has been obtained. When a high valent metal fluoride is used as a fluorinating agent, the reaction proceeds relatively slowly, but requires a process for obtaining the fluorinating agent, and in which a fluorine gas must be used, and The process becomes complicated. Electrolytic fluorination involves the use of anhydrous hydrogen fluoride, which is relatively easily available industrially, and the replacement of hydrogen atoms by fluorine atoms without harming organic compounds having a functional group in the molecule. Is possible, but the unreacted organic compound and the partially fluorinated organic compound dissolve in the produced organic fluorinated compound and hinder fluorination, so that the completely fluorinated compound (perfluoro compound) and the partially fluorinated compound A mixture will be obtained,
Generally, the yield is low. In addition, an attempt to increase the yield lowers the current efficiency. Furthermore, the consumption of nickel or nickel alloy used as the anode cannot be ignored.

In any of the above methods, the yield of the desired fluorinated product cannot be said to be high, and the reaction product is generally formed by a mixture containing various partially fluorinated products or by cleavage of carbon-carbon bonds. The mixture also contains an organic fluorinated substance having a small molecular weight.

[0005] As a method for improving the above-mentioned drawbacks, many proposals have been made to carry out a fluorination reaction in two steps, particularly for the purpose of obtaining a perfluoro compound. For example, electrolytic fluorination
U.S. Pat. Nos. 3,840,445 and 4,035,250 disclose a separation step and a separation / purification step in the middle.
And the like, as a two-stage reaction using fluorine gas,
The stage performs a pre-reaction under cooling, and the second stage is a method of completing the fluorination reaction under heating.
No. 35 has been proposed.

Further, in the first stage, electrolytic fluorination is performed,
A compound having a relatively high fluorine substitution rate (F / H in the compound is large) is separated, and this is chemically fluorinated (fluorine by chemical treatment using fluorine gas, high valent metal fluoride, chlorine trifluoride, etc.). (US Pat. No. 3,709,800) or the first stage is treated by electrolytic fluorination, and the entire reaction mixture obtained is mixed with fluorine gas, and the reaction mixture is treated as an organic compound. A method has been proposed in which a hydrogen atom remaining in a compound is replaced with fluorine (JP-A-62-54093).
In the two-stage fluorination method, first, in the first-stage reaction, part of hydrogen to be replaced in an organic compound, generally 50
% Or more is replaced with fluorine. After removing the reaction heat generated here, the remaining hydrogen of the partially fluorinated organic compound is completely replaced with fluorine.

[0007]

Although the above two-stage fluorination method is a reasonable method, it is necessary to efficiently obtain a desired fluorinated compound such as a perfluoro compound in the second stage reaction in a high yield. Is not easy.

That is, when the second stage is carried out by electrolytic fluorination, the mixing ratio of a desired fluorinated compound, for example, a lower-order partially fluorinated compound in a perfluoro compound is relatively high,
In addition, purification means such as alkali washing is required, and the yield of the target fluorinated compound with respect to the starting organic compound cannot be said to be sufficient.

Further, even when the second stage is performed by means of chemical fluorination, for example, US Pat. No. 2,496,115
As described in the specification, when a tube reactor is filled with partially fluorinated substances and a conventionally conceivable means such as blowing of fluorine gas is used, the molecular chain is also cleaved due to the influence of heat of reaction. It has been found that it is difficult to obtain a desired fluorinated compound, for example, a perfluoro compound in a high yield by sufficiently controlling the reaction, for example, or increasing the amount of unreacted components.

Accordingly, an object of the present invention is to provide a means for fluorinating a partially fluorinated organic compound to obtain a desired fluorinated compound, particularly a perfluoro compound, with high yield and high efficiency. A reactor is provided.

Further, as a preferred embodiment of the present invention, there is provided a method for efficiently producing a perfluoro compound by fluorine gas using an obtained reaction mixture by electrolytically fluorinating an organic compound.

[0012]

Means for Solving the Problems In order to achieve the above object, the present invention has made intensive studies. As a result, when fluorinating a partially fluorinated organic compound with fluorine gas, it is extremely large in the early stage of the reaction. Fever occurs,
It was found that heating was required in the latter half region to promote the reaction. Therefore, in the first half of the reaction, the partially fluorinated organic compound is brought into a strong turbulent state, which is reacted with dilute fluorine to suppress a certain amount of heat generation and promote the diffusion of heat of reaction. It is also preferable to provide a cooling device as needed to remove heat of reaction. In the latter half, the present inventors searched for a method capable of continuously performing two types of reaction, that is, completing the reaction under a gentle liquid flow, and completed the present invention.

That is, the present invention has a structure in which a tank-like reaction zone is connected to the upper end of the tower-like reaction zone so as to allow gas-liquid flow, and the internal pressure of the tank-like reaction zone is added to the internal pressure of the tower-like reaction zone. The ratio of the internal volume (V2) of the tank-shaped reaction zone to the internal volume (V1) of the column-shaped reaction zone (V2 / V1) is 0.2 to 2. Is supplied to the tank-like reaction zone, and the liquid organic compound is supplied.The liquid is uniformly mixed in the tank-like reaction zone. A process for producing a liquid organic fluorinated product characterized by flowing down in a tower as a piston stream and discharging from a bottom of a tower-like reaction zone.

Further, a preferred embodiment of the present invention is that 20 to 80% of the fluorinated sites of the liquid organic compound are fluorinated in the tank-like reaction zone.

Further, as another preferred embodiment of the present invention, the column-like reaction zone is a step column, each step has a downcomer for flowing down a liquid, and the bottom surface of each step is at least partially vaporized. The present invention also proposes a method for producing a liquid organic fluorinated compound, characterized in that a phase portion is formed to prevent a flowing liquid from flowing back upward and to be brought into contact with a fluorine-containing gas.

Still another preferred embodiment of the present invention is:
The liquid organic compound is a partially fluorinated compound of a compound having a carbon-hydrogen bond. In this case, the ratio H / F of the fluorine atom (F) to the hydrogen atom (H) in the partially fluorinated organic compound as a whole is 1 or less, preferably 0.5 or less, particularly 0.25 or less.
The following is preferred.

Further, the partially fluorinated organic compound is a mixture of a perfluoro compound fluorinated by electrolytic fluorination of the organic compound and a partially fluorinated compound, and the liquid perfluoro organic compound is converted into a specific compound under a specific reaction apparatus and reaction conditions. This is a method for producing a liquid organic fluorinated product to be obtained.

Therefore, in the present invention, the electrolytic fluorination step of the organic compound and the fluorination step using fluorine gas described above are connected, and the reaction mixture discharged from the electrolytic fluorination step can be used as it is or as an unreacted substance. And / or a mixture having a H / F of 1 or less, preferably 0.5 or less, particularly preferably 0.25 or less, obtained by separating and removing low-order fluorinated substances by a separation means such as distillation with fluorine gas. An embodiment in which the raw material is supplied as a raw material to the fluorination step is included.

Further, the present invention has a structure in which a tank-like reaction zone is connected to the upper end of the tower-like reaction zone so as to allow gas-liquid flow, and the internal pressure of the tank-like reaction zone is added to the internal pressure of the tower-like reaction zone. , The internal volume (V2) of the tank-like reaction zone and the internal volume (V
The ratio (V2 / V1) of 1) has a relationship of 0.2 to 2, and the tank-like reaction zone has a liquid organic compound supply port, a gas discharge port, and a stirring means, and a liquid-state is provided below the tower-like reaction zone. There is also provided a fluorination reaction apparatus for a liquid organic compound having an organic fluoride discharge port, a fluorine-containing gas supply port and a heating means.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The most characteristic feature of the present invention is that a liquid organic compound is used as a starting material, and a fluorinated liquid organic fluorinated product is obtained at a high yield. The tank-shaped reaction zone is connected so as to allow gas-liquid flow, the internal pressure of the tank-shaped reaction zone is added to the internal pressure of the tower-shaped reaction zone, and the internal volume (V2) of the tank-shaped reaction zone is It is to use a reactor in which the ratio (V2 / V1) of the internal volume (V1) of the reaction zone is 0.2 to 2, preferably 0.5 to 1.

Here, the tank-like reaction zone means the contents, that is, the liquid organic compound as a raw material to be subjected to the reaction and its fluorination reaction product (including a reaction intermediate product; hereinafter, collectively referred to as a reaction solution). And a fluorine-containing gas are uniformly mixed.

As means for achieving uniform mixing in the tank-like reaction zone, generally the supply speed and position of the liquid to be used for the reaction are taken into consideration, or a stirrer is provided in the tank. The stirrer may be a commonly used paddle stirrer. In addition, one of preferred stirring means is to provide an inner cylinder as a baffle plate in the tank, as described later, to form a circulating flow in which the reaction liquid rises in the inner cylinder and descends between the tank wall and the inner cylinder. The configuration is as follows. In this case, the driving force of the reaction liquid circulation is sufficient with the fluorine-containing gas rising together with the liquid rising in the inner cylinder, but the supply liquid port may be provided so as to inject the supply liquid in the circulation direction of the liquid in the tank. It becomes a preferred form. Alternatively, bubbling mixing using an inert gas such as a nitrogen gas may be performed. In this case, generally, an inert gas may be introduced from the lower part of the tank-like reaction zone. In short, in the tank-like reaction zone,
What is necessary is just to achieve the mixing in which the liquids to be treated are sufficiently mixed, whereby the reaction heat is quickly diffused.

Further, in the tank-like reaction zone, 20 to 80%, preferably 40 to 70%, and more preferably 50 to 70% of the fluorinated reaction sites (for example, hydrogen atoms) of the partially fluorinated organic compound have fluorine atoms. Is preferable, and at this time, a large amount of reaction heat is generated. For this reason, it is particularly preferable to perform sufficient stirring of the liquid, and the partial heating is generally performed by adjusting the Reynolds number to about 10,000 to 1,000,000, more preferably 100,000 to 500,000. To avoid this, the temperature is adjusted by natural heat radiation from the reactor, preferably the supply liquid is cooled and supplied, or a jacket is provided in the tank-like area. In this case, the jacket may be either externally cooled or internally cooled, but it is also a preferable embodiment to employ an internal cooling system that also serves as an inner cylinder.

The column-like reaction zone is a so-called piston flow reaction zone in which the reaction liquid flows unilaterally from one (generally above) to the other (generally below). However,
It does not prevent the formation of a partial pool and the occurrence of uniform mixing therein. For example, a case where small reaction zones are connected in a cascade is also included. It is generally an upright tower, inside which packings and trays are arranged to help disperse the bubbles.

In these towers, a tray tower is preferably used. The type of the shelf is not particularly limited, and a bubble bell tower, a perforated plate tower, a valve tray, a turbo grid tray, a ripple tray, and the like are preferably used. Preferably, a cross-flow is formed with the fluorine-containing gas rising on the tray. Type tray,
That is, it is a stage column having a so-called downcomer. By using such a column tower, even if the column is filled with liquid, the lower surface of each tray can at least partially form a gas phase region, and the liquid flowing down the downcomer is It is not possible to ascend to the upper stage again, and as a result, it becomes a downward flow as a whole.

An outlet for the reaction liquid and a supply port for the fluorine-containing gas are provided below these tower-like reaction zones.

In the present invention, it is also important that the internal pressure of the tank-like reaction zone is added to the internal pressure of the column-like reaction zone. By doing so, the fluorine gas in the fluorine-containing gas is sufficiently absorbed in the reaction solution in the tower-like reaction zone. Another important point is that the ratio (V2 / V1) of the inner volume (V2) of the tank-shaped reaction zone to the inner volume (V1) of the tower-shaped reaction zone is 0.2 to 0.2.
2, preferably 0.5 to 1. By doing so, much of the heat of reaction can be easily removed, the breaking of the carbon chain by local heating can be prevented as much as possible, and the desired fluorinated product can be obtained. By the way, when the ratio of the internal volumes is smaller than 0.2, the effect of providing the tank-like reaction zone in the present invention is poor, and if the reaction temperature is raised in anticipation of perfluorination, the carbon chain may be cut. If mild reaction conditions are used, the desired fluorinated product cannot be obtained sufficiently. Conversely, if the internal volume ratio is too large, it becomes difficult to absorb fluorine gas sufficiently, and similarly, the yield of the desired fluorinated product is reduced.

Thus, a hydrogen atom in the case of a reaction in which a bonded hydrogen atom in a liquid organic compound is replaced with a fluorine atom,
Alternatively, 20 to 80%, preferably 40 to 70%, and more preferably 50 to 80% of the fluorinated sites of the liquid organic compound such as a double bond when a fluorine atom is added, or other functional groups capable of reacting with fluorine. About 70% is fluorinated in a tank-like reaction zone, after which the reaction liquid moves to a tower-like reaction zone. In the tower-like reaction zone, the reaction solution flows down slowly, comes into sufficient contact with the fluorine-containing gas, and the remaining fluorination sites are fluorinated as desired. Therefore, the liquid flow in the tower-like reaction zone is a gentle laminar flow as a whole, and the Reynolds number is about 0.1 to 1,000, preferably about 1 to 100.

Next, in the present invention, if the organic compound to be fluorinated is an organic compound capable of maintaining a liquid state in the reaction system and has a site to be fluorinated,
There is no restriction. Examples of these organic compounds include those having 4 to 2 carbon atoms such as butane, pentane, hexane, heptane, octane, nonane, decane, dodecane, and octadecane.
0, preferably 5 to 12 saturated aliphatic hydrocarbons, unsaturated aliphatic hydrocarbons having 4 to 20 carbon atoms such as butene, pentene, hexene, heptene and dodecene; and aromatics such as benzene, toluene, xylene, indene and acenaphthylene Halogenated hydrocarbons such as aromatic hydrocarbons, ethane dichloride, propane dichloride, and chlorobenzene, propyl alcohol,
Alcohols such as butyl alcohol, amyl alcohol, pentyl alcohol, and cyclohexyl alcohol;
Dibutyl ether, diphenyl ether, anisole,
Tetrahydrofuran, ethers such as dioxane, propionaldehyde, aldehydes such as butyraldehyde, isopropyl methyl ketone, methylphenyl ketone, ketones such as cyclohexanone, lactones such as β-propiolactone, acetic acid, propionic acid, butyric acid,
Carboxylic acids such as acrylic acid and caprylic acid, acid anhydrides such as acetic anhydride and butyric acid, sulfonic acids such as methylsulfonic acid, ethylsulfonic acid, butylsulfonic acid and octylsulfonic acid, acetyl bromide, propionyl chloride, butyryl chloride Acid halides such as, octylamine, dipentylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, aniline, pyridine, amines such as piperidine, amides such as dimethylformamide,
Nitriles such as propionitrile, thiophene, mercaptan, phenylmercaptan, dibutyl sulfide, sulfur-containing compounds such as dimethyl sulfone, morpholine, methyl morpholine, ethyl morpholine, propyl morpholine, morpholine derivatives such as butyl morpholine,
Examples thereof include compounds containing nitrogen and oxygen such as amino acids, carbamic acid, nitrobenzene, phenol, and urea, and generally have at least one oxygen atom, sulfur atom and / or nitrogen atom in the molecule, and An organic compound having a site to be converted is suitably used. Among them, nitrogen-containing compounds, particularly tertiary amine compounds, are preferred.

As described above, the present invention is directed to an organic compound having an active site to be fluorinated. In the case of a compound having too many active sites in one molecule, the heat generated during the fluorination reaction is controlled. It may be difficult to do. Therefore, when there are multiple active sites in one molecule, partial fluorination is performed in advance using electrolytic fluorination or a high valent metal fluoride such as cobalt trifluoride or silver difluoride or other fluorinating agents. Then, it is preferable because the present invention can be carried out more reliably. In this case, the partial fluorination is preferably performed by fluorinating 50% or more of all active sites, preferably 66% or more, particularly preferably about 80 to 99%. Here, when the active site is a hydrogen atom,
The partially fluorinated organic compound refers to an atomic ratio H / F between substituted fluorine atoms and unsubstituted hydrogen atoms in the mixture to be treated.
Is 1 or less, preferably 0.5 or less, and more preferably 0.25 to 0.01.

In this case, it is not necessary that each molecule contained in the mixture has a hydrogen atom and a fluorine atom, and it is not necessary that each molecule contained in the mixture be a perfluorinated molecule and a molecule partially having an unreacted hydrogen atom. It is generally a mixture.

When the present invention is carried out industrially, as a method of obtaining a partially fluorinated organic compound, first, an organic compound is electrolytically fluorinated, and the obtained fluorination reaction mixture is directly used as a fluorination raw material in a two-stage fluorination reaction. It is particularly preferable to use a chemical conversion step. In this case, the electrolytic fluorination step is limited by any known method, for example, the first-stage electrolytic fluorination means described in US Pat. Nos. 3,840,445, 4,035,250 and 3,709,800. Used without.

The conditions for the fluorination reaction of the liquid organic compound in the present invention differ depending on the type of the target organic compound and the magnitude of the heat of reaction during the fluorination reaction, and the optimum conditions should be determined by preliminary experiments and the like. Generally, in a tank-like reaction zone, -10 to 150C, preferably 50 to 1C.
It is preferable to select an appropriate temperature in the range of 20 ° C, more preferably 70 to 100 ° C. Even if the temperature exceeds 150 ° C., the reaction can of course be carried out, but the decomposition reaction gradually increases and the yield of the desired product decreases. At a temperature lower than -10 ° C, the reaction rate decreases, and it becomes difficult to control the reaction in the next column-shaped reaction zone. Further, the reaction pressure is 0.05 to 1 MPa · G at normal pressure.
Preferably, about 0.1 to 0.5 MPa · G is employed. Of course, the higher the pressure, the more advantageous is the dissolution of fluorine gas.However, in consideration of the production cost of the apparatus and the dissolution rate and reaction rate of fluorine gas in the partially fluorinated organic substance of the liquid organic compound, the pressure can be selected from the above range. Good.

After allowing 20 to 80% of the desired organic fluorination reaction to take place in the tank-like reaction zone, the partially fluorinated organic compound is usually continuously moved to the top of the tower-like reaction zone, Let the tower flow down. Of course, it can also be intermittently moved to the top of the tower-like reaction zone. It is particularly preferable that the temperature of the tower-like reaction zone is usually set to be the highest by using a plurality of divided heaters, and the top of the tower be at the lowest temperature. Generally, the bottom of the tower is 100 ~
The temperature is set to 200 ° C., preferably about 130 to 170 ° C., and the top of the tower is appropriately selected from the range of about 70 to 170 ° C., preferably about 100 to 140 ° C. depending on the type of the organic compound to be reacted and the desired degree of fluorination.

Since the liquid in the tower-like reaction zone is generally substantially full of liquid, the pressure in the top of the tower is substantially equal to the pressure in the tank-like reaction zone. The area hydraulic pressure will be applied.

The column-like reaction zone is a packed column or a column packed with Raschig rings or the like, and has at least two or more stages.

At the lower part of the tower-like reaction zone, there is a supply port of a fluorine-containing gas, and usually a fluorine gas alone or a fluorine gas diluted with an inert gas (for example, nitrogen gas or the like) is supplied. It is also preferable to use a fluorine gas containing hydrogen fluoride. The fluorine gas concentration in the fluorine gas-containing gas introduced from the lower part of the tower-like reaction zone is usually 70 to 10
0% by volume. If the fluorine gas concentration is lower than 70% by volume, it may be difficult to complete the target reaction. In addition, the fluorine-containing gas or the inert gas can be arbitrarily introduced not only in the bottom of the column but also in any place of the reactor as needed. Among them, a method in which an inert gas is introduced from the center of the tank-like reaction zone or the tower-like reaction zone to the top of the tower and the concentration of the fluorine gas is reduced toward the upper part of the reactor is a particularly preferred embodiment. At this time, the amount of inert gas is
The reaction can be efficiently carried out by introducing an equivalent to 4 times, particularly 1.5 equivalent to 3 times the amount of the fluorine gas contained in the fluorine-containing gas.

Hereinafter, a specific example of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view of a process for producing a fluorinated product of the present invention and a reaction apparatus used for the process. In the figure, reference numeral 1 denotes a storage tank for a liquid organic compound, which generally stores partially fluorinated compounds. 2 is a reactor used in the present invention,
A tank-shaped reaction zone 4 is connected to the upper part of the tower-shaped reaction zone 3 so as to allow gas-liquid flow. Further, since the lower end of the tank-shaped reaction zone is open at the upper end of the tower-shaped reaction zone, all the internal pressure of the tank-shaped reaction zone is weighted to the tower-shaped reaction zone. Although not shown exactly in FIG. 1, the ratio V2 / V1 between the inner volume (V2) of the tank-shaped reaction zone and the inner volume (V1) of the column-shaped reaction zone is 0.2 to 2, preferably 0.1 to 0.2.
It is configured to be 5 to 1. Further, an inner cylinder 5 is provided in the tank-like reaction zone, and an upward flow region u and a downward flow region d of the liquid are formed. For this reason, the reaction solution forms a circulating flow as indicated by the arrow. This circulating flow is a turbulent flow, and it is preferable that the number of Reynold nozzles be 100,000 or more in the upward flow region u inside the inner cylinder.

The organic compound as a raw material is introduced into the tank-like reaction zone 4 from the storage tank 1 through the line 11. In FIG. 1, the propulsive force is added to the upward flow by supplying the circulating liquid to a position where the upward flow changes. However, as another aspect, the liquid is supplied from above to the downward flow portion of the tank-like reaction zone,
Various modes such as increasing the descending speed can be adopted.

The fluorine gas passes through the pipeline 12, is mixed with nitrogen supplied from a nitrogen gas line 13 as an inert gas, if necessary, and is introduced into the lower part of the tower-like reaction zone 3 through the pipeline 14. Further, if necessary, nitrogen gas is introduced from lines 15 and 16 to an appropriate position in the tower-like reaction zone, and the fluorination is performed by adjusting the concentration of fluorine gas. Since the fluorination is efficiently completed according to the present invention, the fluorine gas amount may be substantially only the theoretical amount of fluorination of the organic compound if the flow rate of the supplied fluorine gas is constant. For example, when the purpose is complete fluorination, the theoretical amount of 10
A range of 0 to 110%, preferably 100 to 105% may be used.

The fluorine gas supplied as the fluorine-containing gas to the tank-like reaction zone is substantially exhausted in the tank-like reaction zone. From the upper part of the tank-shaped reaction zone, a very small amount of an inert gas such as fluorine gas and nitrogen, hydrogen fluoride generated by the reaction, and an organic substance mixed vapor corresponding to the vapor pressure of the organic substance at the temperature in the tank-shaped reaction zone are supplied to a line 17. Then, only the organic matter which is led to the condensation tank 6 and condensed at the set temperature is substantially condensed and circulated to the tank-like reaction zone. Inert gas, hydrogen fluoride and a small amount of fluorine gas and organic matter which are not condensed in the condensation tank 6 are discharged through a line 19. The exhaust gas is subjected to detoxification such as cryogenic separation or alkali washing as required, and is then discarded.

On the other hand, the fluoride of the target liquid organic compound is taken out from the lower part of the columnar reaction zone through the line 20 and stored in the storage tank 7.

FIG. 2 shows an embodiment of the present invention in which a liquid organic compound is partially fluorinated by electrolytic fluorination in the first stage, and then fluorinated by fluorine gas in the second stage. That is, the liquid organic compound is first supplied to the electrolytic fluorination battery 9 and electrolytically fluorinated in an anhydrous hydrogen fluoride solution having an organic compound concentration of about 1 to 20%. A known electrolytic cell is used without any limitation. In general, an electrolytic cell in which a large number of nickel anodes and nickel, iron, or copper cathodes are alternately installed is used.
Electrolysis is performed at about 10 V to about 10 V.

Since the fluorinated organic substance is insoluble in anhydrous hydrogen fluoride and has a large specific gravity, it usually separates into phases and collects at the bottom of the electrolytic cell. This fluorinated compound is a mixture containing unreacted organic compounds and various stages of organic fluorinated compounds.
These mixtures are withdrawn through a pipeline 21 and unreacted organic substances and, if necessary, low fluorinated organic substances are separated by a separation means such as a distillation column 10, and the unreacted substances are circulated to an electrolytic fluorination step. On the other hand, a perfluoro compound or an organic compound that has been advanced to some extent, especially a mixture in which 50% or more of the active sites in all organic substances are in a fluorinated state, that is, a partially fluorinated organic compound is obtained by the following fluorine gas The organic compound is sent to the storage tank 1 to be subjected to the conversion step.

Of course, when 50% or more of the active sites of the organic compound are fluorinated by the first-stage electrolytic fluorination, the above-mentioned separation means may not be used.

The partially fluorinated organic compound stored in the organic compound storage tank 1 is further fluorinated by the process described with reference to FIG. 1 to obtain a desired fluorinated compound, particularly a perfluoro compound.

On the other hand, the means for supplying the fluorine-containing gas to the bottom of the tower-like reaction zone is not particularly limited, but FIG. 2 shows an example in which the ejector 8 is used. It is also effective to withdraw a part of the reaction solution from the bottom of the tower-shaped reaction zone as needed and circulate it through the line 22 to the tank-shaped reaction zone 4 in order to stably carry out the reaction, especially at startup. In some cases. However, according to the present invention, since the reaction can be substantially completed in only one pass, it is not usually necessary to carry out the above-mentioned circulation.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

[0050]

EXAMPLE 1 A reactor 2 of the type shown in FIG.
Was used. The tank-shaped reaction zone 4 has an inner cylinder 200 having an inner diameter of 200 mm, a height of 600 mm, and a capacity of 16 L having a cooling jacket, and has an inner cylinder 5 having an inner diameter of 100 mm and a height of 300 mm, and a circulating flow rising inside the inner cylinder. u with a linear velocity of 1.4
m / sec.

The tower-shaped reaction zone 3 has an inner diameter of 80 mm having a heating jacket, a height of 4800 mm, and a capacity of 24 L, and has 24 internal trays.
It has a downcomer with an inner diameter of 8 mm and a length of 15 mm with 10 mm gas flow holes and 8 mm liquid flow opening diameter. At this time, the thickness of the gas phase formed on the lower surface of the shelf under the following conditions was 4 to 7 mm as determined from a cold model experiment and simulation.

Tributylamine was electrolytically fluorinated by a known method, and a polyfluoroamine liquid produced by phase separation was supplied at 4.0 L / hr through a supply line 11. The raw material polyfluoroamine liquid was analyzed by gas chromatography, gas chromatography / mass spectrometry, and infrared spectroscopy. As a result, the polyfluoroamine compound containing 38% by weight of the remaining hydrogen atoms was contained. H / F was 0.09 and hydrogen atoms were contained at 2.6 mol / kg.

The temperature of the reactor was set at 100 ° C.
A heating / cooling medium was passed through the respective jacket portions so that the upper part of the tower-like reaction zone was 130 ° C, the middle part was 140 ° C, and the lower part was 150 ° C. Also, the pressure at the bottom of the reactor was 0.2 MPa
G.

Fluorine gas is supplied at 430 NL / hr (101% of the theoretical amount) from the bottom of the reactor through the line 14, and at the same time, nitrogen gas is supplied from the line 15 to the lower part of the tank-like reaction zone at 700 NL / hr, and from the line 16 to the column. 100 NL / hr was supplied from the upper part of the reaction zone to one third of the column length.

While keeping the liquid level at the upper part of the reactor constant, the reaction liquid was withdrawn from the lower part of the reactor. The amount of the withdrawn liquid was 3.6 L / hr (yield 90%). The concentration of the polyfluoroamine compound in which hydrogen atoms remained in the withdrawn liquid was 18 ppm. Also, when analyzing the reaction solution that migrated from the lower part of the tank-like reaction zone to the tower-like reaction zone,
58% of the hydrogen atoms in the supplied polyfluoroamine compound were fluorinated in the tank-like reaction zone, and the hydrogen atoms were 1.1 mol / kg. Further, when this operation was performed for one month, no change was observed in the yield or the reactivity.

Comparative Example 1 Of the reactors used in the examples, fluorination was carried out using only the tank-like reaction zone 4. The supply liquid amount was 1.6 L / hr, and 172 NL / h of fluorine gas was supplied from the lower part of the tank-like reaction zone.
Example 1 except that r and nitrogen gas were introduced at 320 NL / hr.
Same as. When the reaction solution was withdrawn while keeping the liquid level at the top of the reactor constant, the yield was 74% and the concentration of the polyfluoroamine compound in which hydrogen atoms remained in the reaction solution was 2%.
It was 0000 ppm.

Comparative Example 2 Of the reactors used in Example 1, fluorination was performed using only the columnar reaction zone 3. The supply liquid is supplied at 2.4 L / hr from the upper part of the column-shaped reaction zone, 258 NL / hr of fluorine gas is supplied from the lower part of the column-shaped reaction zone, and one third of the column length is supplied from the upper part of the column-shaped reaction zone from the upper part of the column-shaped reaction zone. Except that 480 NL / hr was introduced into the position of Example 1, the same operation as in Example 1 was performed. When the reaction liquid was extracted while keeping the liquid level at the top of the tower-like reaction zone constant, the yield was 58% and the concentration of the polyfluoroamine compound in which hydrogen atoms remained in the reaction liquid was 4,000 ppm. Also,
At this time, heat generation was severe in the upper part of the tower-like reaction zone, making it difficult to control the temperature, and the operation could not be performed for a long time.

[0058]

According to the present invention, the reaction liquid and the fluorine-containing gas are reacted in contact with each other in the form of a piston flow after the reaction area in the form of a tank, that is, the reaction area in which the reaction liquid is substantially homogeneously mixed. By using a reaction system having a tower-like reaction zone, the internal pressure of the tank-like reaction zone is particularly weighted to the internal pressure of the tower-like reaction zone, and the inner volume (V2) of the tank-like reaction zone and the content of the tower-like reaction zone The ratio V2 / V1 to the product (V1) is 0.2
By setting the relationship to 2, the organic compound can be fluorinated, and the desired organic fluorine compound can be obtained in a high yield. In particular, it is an object of the present invention to provide a method and an apparatus for producing a liquid organic fluorinated compound suitable for obtaining a perfluoro compound by using a partially fluorinated organic compound as a raw material.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of a fluorination step used in the present invention.

FIG. 2 is a schematic diagram illustrating another embodiment of the present invention.

[Explanation of symbols]

 2: reactor of the present invention 3: tower-like reaction zone 4: tank-like reaction zone 5: an example of a stirring device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaki Yoshinaga 1-1, Mikage-cho, Tokuyama-shi, Yamaguchi F-term in Tokuyama Corporation (reference) 4H006 AA02 AA04 AC30 BC11 BD21 BD80 BD81 BD84 BE53 4K021 AC03 BA04 BA06 DA01 DC11

Claims (7)

[Claims] 1. A structure in which a tank-like reaction zone is connected to the upper end of the tower-like reaction zone so as to allow gas-liquid flow, and the internal pressure of the tank-like reaction zone is added to the internal pressure of the tower-like reaction zone. The ratio of the inner volume (V2) of the tank-shaped reaction zone to the inner volume (V1) of the tower-shaped reaction zone (V2 /
V1) is supplied with a fluorine-containing gas from the bottom of the reactor having a relationship of 0.2 to 2, a liquid organic compound is supplied to the tank-like reaction zone, and the liquid is in a homogeneously mixed state in the tank-like reaction zone. Wherein the liquid flowing down to the column-like reaction zone flows down in the column as a piston flow while being in countercurrent contact with the fluorine-containing gas, and is discharged from the bottom of the column-like reaction zone. . 2. The process according to claim 1, wherein 20 to 80% of the fluorinated sites of the liquid organic compound are fluorinated in the tank-like reaction zone. 3. The column-like reaction zone is a stage column, each stage has a downcomer for flowing down the liquid, and at least a gas phase portion is formed at least partially on the lower surface of each stage to flow down the liquid. The method for producing a liquid organic fluorinated substance according to claim 1, wherein the liquid is contacted with a fluorine-containing gas while preventing the liquid from flowing upward. 4. The process for producing a liquid organic fluorinated product according to claim 1, wherein the liquid organic compound supplied to the tank-like reaction zone has a carbon-hydrogen bond and is a partially fluorinated organic material. . 5. The liquid organic fluorinated compound according to claim 4, wherein the ratio H / F of the fluorine atom (F) to the hydrogen atom (H) in the partially fluorinated organic compound is 1 or less. Production method. 6. A liquid perfluoro organic compound obtained by using a mixture of a perfluoro compound fluorinated by electrolytic fluorination of an organic compound and a partially fluorinated compound as a raw material liquid organic compound. 6. The method for producing a liquid organic fluorinated product according to claim 3, 3, 4, or 5. 7. A structure in which a tank-like reaction zone is connected to the upper end of the tower-like reaction zone so as to allow gas-liquid flow, and the internal pressure of the tank-like reaction zone is added to the internal pressure of the tower-like reaction zone. The ratio of the inner volume (V2) of the tank-shaped reaction zone to the inner volume (V1) of the tower-shaped reaction zone (V2 /
V1) has a relationship of 0.2 to 2, and the tank-shaped reaction zone has a liquid organic compound supply port, a gas outlet and a stirring means, and a liquid organic fluorinated substance outlet, fluorine at the lower part of the tower-shaped reaction zone. An apparatus for fluorinating a liquid organic compound having a gas-containing port and a heating means.