TWI683790B - Manufacturing method of iodine heptafluoride - Google Patents

Abstract

The invention discloses a method for manufacturing iodine pentafluoride, which comprises: supplying iodine heptafluoride gas to a reaction tank having iodine pentafluoride containing a liquid phase containing iodine, and reacting iodine with iodine heptafluoride to produce Steps of iodine pentafluoride. With this method, high-speed generation of iodine pentafluoride can be achieved safely and stably.

Description

Manufacturing method of iodine heptafluoride

The invention relates to a method for producing iodine pentafluoride by reacting iodine with iodine heptafluoride, and a method for producing iodine heptafluoride from iodine pentafluoride.

As a method for producing iodine pentafluoride which is effectively used as a raw material for intermediate production of a fluorinating agent or a fluorine-containing compound, a method of reacting iodine with fluorine is known.

For example, Patent Document 1 discloses "a method for producing iodine pentafluoride by direct fluorination of molten iodine".

Patent Document 2 discloses "(1) A method for producing iodine pentafluoride, which is characterized in that: (a) Fluorine gas is introduced into liquid iodine to react to generate a vapor containing iodine pentafluoride and iodine. Mixture; (b) in the presence of the liquid iodine pentafluoride that has been generated, reacting the vapor mixture with new fluorine gas to produce iodine pentafluoride."

The reaction of fluorine and iodine to generate iodine pentafluoride has a heat of formation exceeding 800 kJ/mol, accompanied by large-scale exotherm. Therefore, regardless of solid (Non-Patent Document 1), liquid (Patent Document 1), and gas (Patent Document 2), if pure iodine is reacted with fluorine, there is a concern that the reaction proceeds locally and exotherms, making it difficult to control the reaction.

In view of the above, in order to "stablely implement the reaction of fluorine and iodine, and ultimately provide a safer and more productive method for producing iodine pentafluoride", Patent Document 3 discloses "a method for producing iodine pentafluoride" The method is characterized in that it reacts fluorine with iodine to produce iodine pentafluoride, and supplies fluorine to the gas phase adjacent to the liquid containing iodine pentafluoride."

The method for producing iodine pentafluoride described in Patent Document 3 is to produce pentafluoro by contacting iodine dispersed or dissolved in iodine pentafluoride in a liquid phase with a gas phase containing fluorine gas, and reacting iodine with fluorine gas The method of iodine.

[Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 54-65196

[Patent Document 2] Japanese Patent Laid-Open No. 58-145602

[Patent Document 3] Specification of International Publication No. WO2008/047871

[Non-patent literature]

[Non-Patent Document 1] Walter C. Schumb, one outsider, "Ind. Eng. Chem.", 1950, 42(7), pp1383~1386

However, in Patent Document 3, by contacting iodine dispersed or dissolved in iodine pentafluoride in the liquid phase with a gas phase containing fluorine gas, and reacting iodine with fluorine gas, pentafluoride of iodine pentafluoride is produced. In the manufacturing method of iodine, if the fluorine in the gas phase is contacted with the iodine vaporized from the liquid phase or the iodine in the liquid phase, the fluorine gas in the gas phase is difficult to dissolve in the iodine pentafluoride in the liquid phase, resulting in There is a concern that the reaction between fluorine gas and iodine is difficult to proceed.

That is, the object of the present invention is to provide a method for producing iodine pentafluoride, which allows iodine pentafluoride to undergo a mild reaction without the occurrence of local reactions and rapid exotherm. A high manufacturing method, in other words, a manufacturing method that produces more iodine pentafluoride per unit time.

Furthermore, an object of the present invention is to provide a method for easily producing iodine heptafluoride from the obtained iodine pentafluoride.

The inventors have made intensive studies and found that by dissolving or dispersing the iodine heptafluoride gas in the reaction system of the reaction tank with iodine pentafluoride containing a liquid phase containing iodine, iodine and iodine heptafluoride Contact and react so that pentafluoride can be produced at a higher production rate Iodine, and even the method for producing iodine pentafluoride of the present invention.

The reaction formula for obtaining iodine pentafluoride (IF ₅ ) from iodine (I ₂ ) and iodine heptafluoride (IF ₇ ) is as follows.

5IF ₇ +I ₂ →7IF ₅

The present inventors focused on the fact that although fluorine gas is difficult to dissolve in liquid phase iodine pentafluoride, iodine heptafluoride gas is easily dissolved in liquid phase iodine pentafluoride. Since fluorine gas is insoluble in iodine pentafluoride in the liquid phase, the reaction of fluorine gas and iodine in liquid iodine pentafluoride is a gas-liquid reaction or a gas-solid reaction, and it cannot be expected to increase the generation rate of iodine pentafluoride. However, iodine heptafluoride gas is easily soluble in liquid iodine pentafluoride. The reaction of iodine heptafluoride in liquid iodine pentafluoride with iodine is not only gas-liquid reaction, gas-solid reaction, but also heptafluoride The liquid-solid reaction or liquid-liquid reaction of iodine and iodine proceeds to achieve a higher generation rate of iodine pentafluoride.

As shown in Example 1 and Comparative Example 2 of this specification, the iodine heptafluoride gas is supplied to the reaction tank having iodine pentafluoride containing a liquid phase containing iodine according to the present invention to react iodine with iodine heptafluoride The production method of iodine pentafluoride” was carried out quickly to obtain iodine pentafluoride (Example 1). In contrast, the previous method was “to the gas phase adjacent to the liquid containing iodine pentafluoride It is difficult to produce iodine pentafluoride by supplying fluorine to react iodine with fluorine (Comparative Example 2).

In addition, the inventors of the present invention have found a method for easily producing iodine heptafluoride from the obtained iodine pentafluoride.

That is, the present invention includes the following inventions 1 to 9.

〔Invention 1〕

A method for manufacturing iodine pentafluoride, which comprises: supplying iodine heptafluoride to a reaction tank with a liquid phase containing iodine containing iodine pentafluoride, and reacting iodine with iodine heptafluoride to produce iodine pentafluoride step.

〔Invention 2〕

The method of manufacturing iodine pentafluoride according to invention 1, wherein the reaction between iodine and iodine heptafluoride In the process, iodine heptafluoride was supplied while stirring in the reaction tank.

〔Invention 3〕

The method for producing iodine pentafluoride according to invention 1 or invention 2, wherein the iodine pentafluoride in the liquid phase containing iodine is in a solution state containing dissolved iodine, or a state in which solid iodine is dispersed and deposited in the liquid phase.

〔Invention 4〕

The method for producing iodine pentafluoride according to inventions 1 to 3, wherein the iodine pentafluoride in the above-mentioned liquid phase containing iodine is expressed in terms of the content ratio with respect to the total amount of iodine and iodine pentafluoride, including 0.01 weight of iodine % To 70% by weight.

〔Invention 5〕

The manufacturing method of iodine pentafluoride according to inventions 1 to 4, wherein the iodine pentafluoride in the above-mentioned liquid phase containing iodine is expressed as a content rate relative to the total amount of iodine, iodine pentafluoride and iodine heptafluoride , Containing iodine heptafluoride 0.001% by weight or more and 91% by weight or less.

〔Invention 6〕

A method for manufacturing iodine heptafluoride, comprising: using the method for manufacturing iodine pentafluoride of inventions 1 to 5, reacting iodine with iodine heptafluoride to obtain iodine pentafluoride, and allowing fluorine gas to obtain The step of reacting iodine pentafluoride to obtain iodine heptafluoride.

〔Invention 7〕

The manufacturing method of iodine heptafluoride according to invention 6, wherein in the step of obtaining the above iodine heptafluoride, iodine pentafluoride gas and fluorine gas are supplied to a reactor having a filler containing metal fluoride inside, and Its other reactions.

〔Invention 8〕

The method for producing iodine heptafluoride according to invention 7, wherein the metal fluoride contains at least one compound selected from the group consisting of NiF ₂ , FeF ₃ , and CoF ₂ .

〔Invention 9〕

The method for producing iodine heptafluoride according to invention 7 or invention 8, wherein the temperature of the metal fluoride when the iodine pentafluoride gas reacts with the fluorine gas is 150°C or more and 350°C or less.

According to the method for producing iodine pentafluoride of the present invention, the generation rate of iodine pentafluoride can be increased, and iodine heptafluoride can be easily produced from the iodine pentafluoride produced by this production method.

10‧‧‧Reaction device

11‧‧‧Reaction tank (cooled by cooler)

12‧‧‧Solid iodine

13‧‧‧Iodine pentafluoride (dissolved iodine)

14‧‧‧gas phase

15‧‧‧liquid phase (iodine pentafluoride)

16‧‧‧Supply source of iodine heptafluoride

17‧‧‧Iodine supply source

18‧‧‧Supply source of inert gas

19‧‧‧Pump

20‧‧‧Agitator

Fig. 1 is an explanatory diagram showing a reaction apparatus of an embodiment.

1. Manufacturing method of iodine pentafluoride

The present invention is a method for producing iodine pentafluoride, which includes supplying iodine heptafluoride gas to a reaction tank having iodine pentafluoride containing a liquid phase containing iodine to react iodine with iodine heptafluoride to produce pentafluoride Steps to iodine.

An example of the embodiment of the method for producing iodine pentafluoride of the present invention will be described using FIG. 1. The present invention is not limited to the embodiments shown below.

Furthermore, in the present invention, the liquid phase refers to a phase in which a substance is in a liquid state, and the gas phase refers to a phase in which a substance is in a gas state.

〔Reaction device〕

The reaction device 10 of the embodiment of the method for producing iodine pentafluoride of the present invention is shown in FIG. 1. The reaction device 10 has an iodine pentafluoride 13 in a liquid phase (liquid state) in which iodine 12 is precipitated, dispersed or dissolved in the reaction tank 11. Iodine heptafluoride is supplied to the liquid phase 15 in the reaction tank 11, and the iodine heptafluoride and iodine 12 are reacted in the liquid phase 15, thereby generating iodine pentafluoride.

At this time, iodine heptafluoride may be supplied to the liquid phase 15 or the gas phase 14. When iodine heptafluoride is supplied to the liquid phase 15, iodine heptafluoride moves in the gas phase 14 at a certain ratio. When iodine heptafluoride is supplied to the gas phase 14, heptafluoride Iodine according to A certain ratio moves in the liquid phase 15. By blowing iodine heptafluoride into the liquid phase 15 containing iodine 12 and iodine pentafluoride, the iodine heptafluoride can be quickly dissolved in the liquid phase 15, and the reaction between iodine heptafluoride and iodine 12 can be efficiently carried out , Thereby increasing the rate of iodine pentafluoride formation.

The iodine heptafluoride is preferably supplied to the liquid phase 15 from the iodine heptafluoride supply source 16 attached to the reaction tank 11. Since the vapor pressure of iodine pentafluoride is low, in order to easily control the pressure of the reaction tank 11 and ensure the driving pressure of the pump 19, the inert gas can also be used as a buffer gas (buffer) from the inert gas supply source 18 attached to the reaction tank 11 It is preferably supplied to the reaction tank 11 and preferably to the gas phase 14. Examples of the inert gas include gases that do not react with iodine, iodine heptafluoride, or iodine pentafluoride, such as nitrogen, argon, and helium. Nitrogen, which is easily available, is preferred.

In the reaction between iodine 12 and iodine heptafluoride, the liquid phase 15 in the reaction tank 11 is stirred by the pump 19 or the stirrer 20.

[Reaction of iodine with iodine heptafluoride]

The reaction of iodine and iodine heptafluoride occurs in the gas phase 14, the liquid phase 15, or the interface between the gas phase 14 and the liquid phase 15. That is, in the liquid phase 15, the iodine 12 present in the iodine pentafluoride 13 becomes a gas corresponding to the vapor pressure, moves in the gas phase 14, and reacts with the iodine heptafluoride present in the gas phase 14. In addition, the iodine heptafluoride present in the gas phase 14 moves from the gas phase 14 to the liquid phase 15 and reacts with the iodine 12 present in the liquid phase 15. In addition, iodine heptafluoride present in the gas phase 14 and iodine 12 present in the iodine pentafluoride 13 in the liquid phase 15 react at the interface between the gas phase 14 and the liquid phase 15. Also, in the liquid phase 15, iodine heptafluoride reacts with iodine 12 present in iodine pentafluoride 13.

The reaction tank 11 may be cooled by a water cooling device (not shown). In the reaction of iodine and iodine heptafluoride, it is preferable to maintain the state of the liquid phase by maintaining the temperature of the liquid phase 15 in the reaction tank 11 at 10°C or higher and 95°C or lower. When the liquid phase 15 is maintained at less than 10°C, there is a concern that the iodine pentafluoride 13 solidifies, and the energy consumption required for cooling also increases. On the other hand, when the liquid phase 15 is maintained at a temperature higher than 95°C, not only does the pressure in the reaction tank 11 become higher during the reaction, but it also occurs in the liquid phase 15 dissolved in iodine pentafluoride 13 Seven The decrease in the amount of iodine fluoride may cause problems such as a decrease in the production rate of iodine pentafluoride. The maintenance temperature of the liquid phase 15 is preferably 15°C or higher and 75°C or lower, more preferably 20°C or higher and 50°C or lower.

The pressure of the gas phase 14 in the reaction tank 11 during the reaction is preferably 40 kPa or more and 133 kPa or less in absolute pressure, more preferably 67 kPa or more and 101 kPa or less. If the pressure in the reaction tank 11 is less than 40 kPa, the amount of iodine heptafluoride dissolved in iodine pentafluoride 13 decreases, and the production rate of iodine pentafluoride decreases. If the pressure in the reaction tank 11 is higher than 133 kPa, the reaction tank 11 must have a pressure-resistant structure. The pressure can be adjusted according to the supply rate of iodine heptafluoride gas 16, cooling of the reaction tank 11, addition of inert gas, and the like. Although the supply rate of iodine heptafluoride depends on the size of the reaction device and the scale of the reaction, during the reaction, the pressure of the gas phase 14 in the reaction tank 11 preferably falls within the above range.

[Content of iodine and iodine heptafluoride during the reaction]

Iodine 12 may be charged into the reaction tank 11 before the start of the reaction, or may be grounded or continuously supplied from the iodine supply source 17 into the reaction tank 11 at the start of the reaction and in the middle of the reaction process. In the method for producing iodine pentafluoride of the present invention, the content rate of iodine 12 in the reaction tank 11 is expressed as a content rate in which the total amount of iodine in the reaction tank 11 and iodine pentafluoride is 100% by weight, It is preferably 0.01% by weight or more and 70% by weight or less.

If the content of iodine is less than 0.01% by weight, the amount of iodine pentafluoride produced is small. If the content of iodine is more than 70% by weight, there is a possibility that the reaction heat may not be removed, causing a local reaction or a reaction out of control. Furthermore, in order to increase the production volume of iodine pentafluoride, the concentration of iodine 12 is preferably higher, more preferably 1% by weight to 60% by weight.

Furthermore, although it also depends on conditions such as temperature and pressure, in the liquid phase 15, iodine 12 cannot be dissolved in the liquid iodine pentafluoride 13 by about 1% by mass or more. Iodine 12, which cannot be dissolved in iodine pentafluoride 13, will be dispersed in a solid state and deposited in the liquid phase 15.

During the reaction, it is preferable to supply iodine heptafluoride from the iodine heptafluoride supply source 16 to the liquid phase 15 of the reaction tank 11. By supplying iodine heptafluoride gas into the gas phase 14, it is also carried out The reaction of iodine 12 with iodine heptafluoride can also produce iodine pentafluoride. However, in order to improve the reaction efficiency of iodine 12 and iodine heptafluoride, iodine pentafluoride is produced at a relatively high production rate, and it is preferable to supply iodine heptafluoride to the liquid phase 15.

During the reaction, the content of iodine heptafluoride in the liquid phase 15 in the reaction tank 11 is such that the total amount of iodine pentafluoride 13 and iodine heptafluoride in the reaction tank 11 is set to 100% by weight The ratio indicates that it is preferably 0.001% by weight or more and 91% by weight or less. If the content of iodine heptafluoride in the liquid phase 15 is less than 0.001% by weight, the amount of iodine pentafluoride produced becomes smaller. If the concentration of iodine heptafluoride is more than 91% by weight, the temperature and pressure of the reaction tank 11 may rise, and there is a risk of local reaction or runaway reaction. More preferably, the content of iodine heptafluoride is 0.01% by weight or more and 64% by weight or less.

The purity of the iodine heptafluoride supplied to the liquid phase 15 is preferably 98% by weight or more, and more preferably 99% by weight or more. When the purity of iodine heptafluoride is low, the purity of iodine pentafluoride as a product may decrease.

〔Stirring〕

In the reaction of reacting iodine 12 in liquid phase 15 with iodine heptafluoride to obtain iodine pentafluoride, it is preferred to stir the liquid phase in order to avoid local heterogeneous reaction or excessive heat of reaction. 15. As a method for agitating the liquid phase 15 in the reaction tank 11, agitation in which the liquid phase 15 is circulated by the pump 19 or agitation using a stirrer 20 having a rotary wing can be exemplified. When the liquid phase 15 is stirred by the pump 19, in order to ensure the driving pressure of the pump 19, it is preferable to introduce an inert gas at a specific pressure into the reaction tank 11. For example, the inert gas system is supplied from the inert gas supply source 18. Examples of the inert gas include gases that do not react with iodine, iodine heptafluoride, or iodine pentafluoride, such as nitrogen, argon, and helium. As the purity of the inert gas, in order not to affect the purity of the product iodine pentafluoride, it is preferably high purity, preferably 99% by weight or more. Nitrogen, which is easily available, is preferred.

[Purity of iodine and iodine heptafluoride]

The purity of iodine and iodine heptafluoride used in the method for producing iodine pentafluoride of the present invention is There is no particular limitation on the aspect of implementing the present invention. However, the purity of iodine and iodine heptafluoride will affect the purity of the generated iodine pentafluoride. For example, in order to obtain 99% by weight or more of iodine pentafluoride, it is preferable to use iodine and iodine heptafluoride having a purity of 99% by weight or more.

In addition, when the iodine heptafluoride gas supplied from the iodine heptafluoride supply source 16 contains an inert gas, the inert gas has the effect of stirring the liquid phase 15 in the reaction tank 11 by bubbling, Thus, the heat of reaction when iodine 12 is reacted with iodine heptafluoride to obtain iodine pentafluoride is removed. However, since the pressure of the reaction tank 11 increases with time due to the increase of the partial pressure of the inert gas, it is necessary to install a pressure adjustment valve to control the pressure.

2. Manufacturing method of iodine heptafluoride

The present invention is a method for producing iodine heptafluoride, which comprises the steps of obtaining iodine pentafluoride by reacting iodine with iodine heptafluoride using the method for producing iodine pentafluoride, and making the obtained iodine pentafluoride and The step of reacting fluorine gas to obtain iodine heptafluoride.

By reacting the iodine pentafluoride obtained by the above-mentioned method for producing iodine pentafluoride of the present invention with fluorine gas, iodine heptafluoride can be produced.

As an example of a method for obtaining iodine heptafluoride by reacting iodine pentafluoride with fluorine gas, the following method may be mentioned: iodine pentafluoride gas and fluorine obtained by blowing fluorine gas into a liquid of iodine pentafluoride The gas is introduced into the reactor together, and iodine pentafluoride gas is reacted with fluorine gas to obtain iodine heptafluoride. Alternatively, a method of vaporizing iodine pentafluoride by heating to produce iodine pentafluoride gas and supplying it to the reactor, or a method of directly supplying iodine pentafluoride in the liquid phase to the reactor may also be considered.

In the case where a method of supplying iodine pentafluoride gas and fluorine gas to a reactor and reacting it to obtain iodine heptafluoride is adopted, in this step, it is preferable to have a high temperature containing metal fluoride inside Iodine pentafluoride gas and fluorine gas are supplied to the reactor of the packing. By using fillers, the yield of iodine heptafluoride based on iodine pentafluoride can be increased, for example, the yield can be increased to more than 70%.

The metal fluoride contained in the filler used in the method for producing iodine heptafluoride of the present invention is not particularly limited as long as it fluorinates the metal. For example, examples of the metal fluoride include NiF ₂ , FeF ₃ , CoF ₂ , LiF, NaF, KF, CsF, MgF ₂ or CaF ₂ , or _two or more of these may be mixed. In consideration of cheapness and a large contribution to the improvement in yield, it is preferable to use any one or more fillers including NiF ₂ , FeF ₃ , and CoF ₂ as fluorides of transition metals.

The shape of the filler used is not particularly limited as long as the iodine pentafluoride gas and fluorine gas are efficiently contacted and the gas does not block during circulation. The filler can be obtained, for example, by fluorinating a net-shaped metal sheet with fluorine gas, chlorine trifluoride gas, iodine heptafluoride gas, etc. to generate metal fluoride on the metal surface, or by powdering metal fluoride The compound is obtained by molding into a particle shape.

The temperature of the filler when reacting iodine pentafluoride gas with fluorine gas to obtain iodine heptafluoride is preferably 150° C. or higher and 350° C. or lower. If the temperature of the filling material does not reach 150°C, the production rate of iodine heptafluoride from iodine pentafluoride gas and fluorine gas may decrease. If it exceeds 350°C, the generated iodine heptafluoride may decompose It is the risk of reverse reaction of iodine pentafluoride and fluorine. The temperature of the particularly good filler is above 200°C and below 330°C. For example, the filler can be set to a desired temperature by heating the reactor with an electric heater, steam, or the like while being filled with the filler.

In the above reaction of reacting iodine pentafluoride gas with fluorine gas to obtain iodine heptafluoride, as long as the reaction temperature does not become significant in the reverse reaction, not only the iodine pentafluoride gas and fluorine gas in the reactor are retained The time increases, and the yield of iodine heptafluoride also increases. There is a risk that the productivity of iodine hexafluoride will decrease due to the increase in residence time. Considering the required yield and productivity of iodine hexafluoride, the residence time of iodine pentafluoride gas and fluorine gas in the reactor can be Make various choices. When considering the productivity of iodine heptafluoride, the residence time of the iodine pentafluoride gas and fluorine gas in the reactor is expected to be shorter. For example, when the molar ratio of F ₂ /IF ₅ is 1 or more, when iodine pentafluoride gas is reacted with fluorine gas to obtain iodine heptafluoride, if the temperature of the metal fluoride is 200° C. or more and 330 Below ℃, and at least the residence time of iodine pentafluoride gas and fluorine gas is more than 4 seconds, you can get more than 80% yield.

In the case of using a flow-through reactor to react iodine pentafluoride gas with fluorine gas to obtain iodine heptafluoride, the flow rate ratio at the time of introduction of iodine pentafluoride gas and fluorine gas, or when using a closed reactor In this case, the mixing ratio of iodine pentafluoride gas and fluorine gas is preferably 1 or more in terms of the molar ratio of iodine pentafluoride to fluorine (F ₂ /IF ₅ ). In particular, if the molar ratio is 1.3 or more, the yield of iodine heptafluoride can be more than 80% when the residence time of iodine pentafluoride gas and fluorine gas is 4 seconds or more, but if the molar ratio is When (F ₂ /IF ₅ ) is set to 35 or more, the yield of iodine heptafluoride is improved, and the decrease in economic efficiency due to the increase in the use of fluorine gas becomes significant, which is not good. In addition, if the molar ratio (F ₂ /IF ₅ ) is less than 1, there is a possibility that the yield of iodine heptafluoride may decrease due to an increase in unreacted iodine pentafluoride.

The pressure in the reactor during the reaction to obtain iodine heptafluoride from iodine pentafluoride gas and fluorine gas is fluorine, iodine pentafluoride, and iodine heptafluoride are toxic, so in order to prevent leakage, it is preferably below atmospheric pressure In consideration of economy, it is preferably 40 kPa (absolute pressure) or more.

[Example]

The examples and comparative examples of the present invention are listed below, but the present invention is not limited to the following examples.

Example 1

As shown in FIG. 1, to a 2.3 L stainless steel reaction tank 11 in which the gas in the tank was replaced with nitrogen, liquid iodine pentafluoride 13 with a mass of 3036 g was added, followed by solid iodine 12 with a weight of 3710 g. The concentration of iodine 12 in the liquid iodine pentafluoride 13 at the time of addition was about 55% by weight relative to the total weight of iodine pentafluoride 13 and solid iodine 12 in total. As a method of stirring the solid iodine 12 and iodine pentafluoride 13 in the liquid phase 15, the pump 19 is driven to circulate the liquid phase 15. The iodine heptafluoride gas is supplied to the liquid phase 15 at a flow rate of 0.6 L/min from the iodine heptafluoride supply source 16 to react the iodine heptafluoride gas with the solid iodine 12 in the iodine pentafluoride 13 to obtain five Iodine fluoride. During the reaction, the pressure in the reaction tank 11 was maintained at 93 kPa (absolute pressure). Again, one The surface cooling makes the internal temperature of the reaction tank 11 during the reaction 30 to 60°C, and the reaction is carried out for 60 minutes. Except for the portion charged before the start of the experiment, the newly generated amount of iodine pentafluoride is 499g.

Example 2

As a stirring method, the stirrer 20 equipped with a rotating wing was rotated at 100 rpm to stir the liquid phase 15, and the liquid phase 15 was circulated by using the pump 19 instead of the pump in Example 1 except that the liquid phase 15 was circulated. Ground, reacting iodine heptafluoride gas with solid iodine 12. Except for the portion charged before the start of the experiment, the newly generated amount of iodine pentafluoride is 499g.

Irrespective of the use of a pump, agitator, or any agitating device, by reacting iodine in iodine pentafluoride with iodine heptafluoride, heat can be efficiently removed, and iodine pentafluoride can be produced safely and stably.

Comparative example 1

To a 2.3 L stainless steel reaction tank 11 in which the gas in the tank was replaced with nitrogen, solid iodine 12 with a mass of 3710 g was added, and iodine heptafluoride gas was supplied from an iodine heptafluoride gas supply source at 0.6 L/min to make It reacts directly with solid iodine 12. The pressure in the reaction tank during the reaction was controlled to 93 kPa (absolute pressure), but after 5 minutes from the supply of iodine heptafluoride gas, a reaction was found near the supply port of iodine heptafluoride gas in the reaction tank 11 The temperature rise caused by heat had to stop the supply of iodine heptafluoride gas and interrupt the reaction.

Table 1 shows the production conditions and results of each example.

Among the liquid 5 iodine fluoride, in Examples 1 to 2 in which iodine heptafluoride reacts with iodine, at a supply rate of 0.6 L/min to the liquid phase 15 to supply iodine heptafluoride gas, no The reaction "5IF ₇ +I ₂ →7IF ₅ "is accompanied by local exotherm, and 499 g of iodine pentafluoride is obtained every hour. In this way, it can be confirmed that the production method of iodine pentafluoride of the present invention has a large output per unit time and can produce iodine pentafluoride at a high speed.

However, in Comparative Example 1, which does not belong to the scope of the present invention, which directly reacts iodine heptafluoride with fixed iodine, the reaction "5IF ₇ +I ₂ →7IF ₅ "generates local exotherm, and the reaction has to be interrupted.

Comparative example 2

To a 2.3 L stainless steel reaction tank 11 in which the gas in the tank was replaced with nitrogen, liquid iodine pentafluoride 13 with a mass of 3036 g was added, and solid iodine 12 with a mass of 3710 g was added. The concentration of solid iodine 12 is about 55% by weight relative to the total weight of iodine pentafluoride 13 and solid iodine 12 at the time of addition. The liquid phase 15 was stirred at 100 rpm with a stirrer equipped with a rotating wing.

Under stirring, fluorine gas diluted with nitrogen to 70% by volume was supplied to the gas phase 14 of the reaction vessel 11 to start the reaction to obtain iodine pentafluoride from iodine and fluorine gas. The pressure in the reaction tank 11 during the reaction is maintained at 93 kPa (absolute pressure) by the pressure regulating valve. Furthermore, while cooling, the temperature of the reaction tank 11 during the reaction is 30 to 60°C, and the reaction is performed for 60 minutes.

Regarding the concentration of the fluorine gas discharged from the pressure adjustment valve, the spectrophotometric analysis obtained by the ultraviolet-visible-near infrared spectrophotometry using a spectrophotometer UV-Vis (manufactured by Hitachi High-Technologies Co., Ltd. model U2810), the results are approximately As 70% by volume progresses, the fluorine gas is almost not consumed, and the reaction to obtain iodine pentafluoride from iodine and fluorine gas does not proceed. Except for the part loaded before the experiment, the newly generated amount of iodine pentafluoride is only 0.0025g.

Example 3

Using the iodine pentafluoride obtained in Example 1, iodine heptafluoride was synthesized. The specific manufacturing sequence is as follows.

Nickel fluoride (NiF ₂ ) (purity 99%, manufactured by Apollo Scientific Limited), which is a metal fluoride, was formed into particles (4 mm×4 mm×2 mm in size) by press molding. A bright annealed tube made of nickel (inner diameter 22.1 mm, length 0.3 m) equipped with an electric heater and a pressure gauge used as a reactor was filled with 48 g (0.5 mole) of particulate nickel fluoride. The bright annealing tube is heated by an electric heater, thereby setting the temperature of the above-mentioned particles as a filler to 270°C. At this temperature, the mixed gas of fluorine (F ₂ ) and iodine pentafluoride (IF ₅ ) (mol ratio (F ₂ /IF ₅ )=30.3 (F ₂ concentration 96.8% by volume, IF ₅ concentration 3.20% by volume )) is introduced from one end (inlet) of the two ends of the bright annealing tube and discharged from the other end (outlet).

At this time, the pressure in the bright annealing tube was set to 66.7 kPa (absolute pressure), and the mixed gas was circulated for 1 hour at a flow rate of 1730 cm ³ /min (retention time 4 seconds). In addition, when the mixed gas flows, the gas from the outlet of the reactor is introduced to the cooling trap. Using liquid argon (temperature: -186°C) as the cooling medium for cooling the trap, the iodine heptafluoride and iodine pentafluoride are cooled and captured. After the circulation of the mixed gas is completed, the weight of the captured object in the cooling trap is measured, and the obtained seventh is obtained by using Fourier Transform Infrared Spectrophotometer (FT-IR) (Shimadzu Corporation, trade name: Prestige21). The composition of iodine fluoride and iodine pentafluoride was analyzed. Based on the results of gravimetry and composition analysis, the yield relative to the theoretical capture amount of iodine pentafluoride based on the supply of iodine pentafluoride IF _{5 was} calculated. The yield was 99.8%.

10‧‧‧Reaction device

11‧‧‧Reaction tank (cooled by cooler)

12‧‧‧Solid iodine

13‧‧‧Iodine pentafluoride (dissolved iodine)

14‧‧‧gas phase

15‧‧‧liquid phase (iodine pentafluoride)

16‧‧‧Supply source of iodine heptafluoride

17‧‧‧Iodine supply source

18‧‧‧Supply source of inert gas

19‧‧‧Pump

20‧‧‧Agitator

Claims (7)

A method for manufacturing iodine heptafluoride, comprising: supplying iodine heptafluoride to a reaction tank having a liquid phase containing iodine containing iodine pentafluoride, and iodine and heptafluoride in liquid phase iodine pentafluoride The step of reacting iodine to obtain iodine pentafluoride; and the step of reacting fluorine gas with the obtained iodine pentafluoride to obtain iodine heptafluoride. _2. Iodine pentafluoride gas and fluorine gas are supplied to the reactor of the filler of at least one metal fluoride of the group consisting of FeF ₃ and CoF ₂ , and the temperature of the metal fluoride is 150°C or more and The reaction proceeds below 350°C. The method for producing iodine heptafluoride according to claim 1, wherein in the step of obtaining the iodine pentafluoride, in the reaction of iodine and iodine heptafluoride, heptafluoride is supplied while stirring in the reaction tank Iodine gas. The method for producing iodine heptafluoride according to claim 1, wherein in the step of obtaining the iodine pentafluoride, the iodine pentafluoride in the liquid phase containing iodine is in the state of a solution containing dissolved iodine, or in the liquid phase The state of solid iodine dispersed and Shendian. The method for producing iodine heptafluoride according to claim 2, wherein in the step of obtaining the iodine pentafluoride, the iodine pentafluoride in the liquid phase containing iodine is in the state of a solution containing dissolved iodine, or in the liquid phase The state of solid iodine dispersed and Shendian. The method for producing iodine heptafluoride according to any one of claims 1 to 4, wherein in the step of obtaining the iodine pentafluoride, the iodine pentafluoride in the liquid phase containing iodine is compared with The content rate of the total amount of iodine fluoride is 0.01% or more and 70% or less of iodine. The method for producing iodine heptafluoride according to any one of claims 1 to 4, wherein in the step of obtaining the iodine pentafluoride, in the iodine pentafluoride in the liquid phase containing iodine, the phase The content rate of the total amount of iodine pentafluoride and iodine heptafluoride is expressed as including 0.001 wt% or more and 91 wt% or less of iodine heptafluoride. The method for producing iodine heptafluoride according to claim 5, wherein in the step of obtaining the iodine pentafluoride, the iodine pentafluoride in the liquid phase containing iodine is compared with the iodine pentafluoride and iodine heptafluoride The content rate of the total amount indicates that iodine heptafluoride is included in 0.001% by weight or more and 91% by weight or less.

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