JP6687843B2 - Method for producing iodine pentafluoride - Google Patents

Description

  The present 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 useful as a raw material for producing an intermediate for 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 that "(1) (a) liquid iodine is reacted with fluorine gas through a fluorine gas to produce a vapor mixture containing iodine pentafluoride and iodine, and (b) liquid pentafluoride that has already been produced. A method for producing iodine pentafluoride, which comprises reacting the vapor mixture with fresh fluorine gas in the presence of iodine to further generate iodine pentafluoride. "

  The reaction of reacting fluorine with iodine to generate iodine pentafluoride has a heat of formation exceeding 800 kJ / mol and is accompanied by a large amount of heat generation. Therefore, when pure iodine and fluorine are reacted regardless of solid (non-patent document 1), liquid (patent document 1), and gas (patent document 2), they react locally to generate heat and it is difficult to control the reaction. There was a concern.

  In view of the above, Patent Document 3 discloses that "a reaction between fluorine and iodine is carried out gently, and as a result, a method for producing iodine pentafluoride which is safer and more excellent in productivity is provided. "A method for producing iodine pentafluoride by reacting fluorine with iodine, which comprises supplying fluorine to a gas phase adjacent to a liquid phase of iodine pentafluoride containing iodine. A method for producing iodine fluoride "is disclosed.

  In the method for producing iodine pentafluoride described in Patent Document 3, iodine dispersed and dissolved in liquid phase iodine pentafluoride is brought into contact with a gas phase containing fluorine gas to react iodine with fluorine gas. This is a method for producing iodine pentafluoride.

JP-A-54-65196 JP-A-58-145602 Pamphlet of International Publication WO2008 / 047871

Walter C. Schumb, 1 other person, "Ind. Eng. Chem.", 1950, 42 (7), pp 1383 to 1386

  However, iodine pentafluoride is produced by bringing iodine dispersed in or dissolved in liquid-phase iodine pentafluoride described in Patent Document 3 into contact with a gas phase containing fluorine gas to react iodine with fluorine gas. In the method for producing iodine pentafluoride, as long as fluorine in the gas phase is contacted with iodine vaporized from the liquid phase or iodine in the liquid phase, fluorine gas in the gas phase becomes iodine pentafluoride in the liquid phase. There was a concern that it would be difficult to dissolve and the reaction between fluorine gas and iodine would be difficult to proceed.

  That is, the present invention is a method for producing iodine pentafluoride with a high production rate of iodine pentafluoride by a mild reaction of iodine pentafluoride without causing a local reaction and sudden heat generation, in other words, per unit time of pentafluoride. It is an object to provide a production method that produces a large amount of iodine.

  A further object of the present invention is to provide a method for producing iodine heptafluoride that easily produces iodine heptafluoride from the obtained iodine pentafluoride.

  As a result of diligent studies by the present inventors, the iodine heptafluoride gas was dissolved or dispersed in a reaction system having a liquid phase iodine pentafluoride containing iodine, and iodine was contacted with iodine heptafluoride. It was found that it is possible to produce iodine pentafluoride with a high production rate by carrying out the reaction, and has completed 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.

  The present inventors have noted that fluorine gas is difficult to dissolve in liquid-phase iodine pentafluoride, but iodine heptafluoride gas is easily dissolved in liquid-phase iodine pentafluoride. Since fluorine gas is poorly soluble in liquid phase iodine pentafluoride, the reaction between fluorine gas and iodine in liquid phase iodine pentafluoride is a gas-liquid reaction or a gas-solid reaction, and iodine pentafluoride is produced. You cannot expect to increase the speed. However, iodine heptafluoride gas is easily dissolved in liquid phase iodine pentafluoride, and the reaction between iodine heptafluoride and iodine in liquid phase iodine pentafluoride is only gas-liquid reaction or gas-solid reaction. Instead, it proceeds by a liquid-solid reaction or a liquid-liquid reaction between iodine heptafluoride and iodine, and the production rate of iodine pentafluoride is high.

  As shown in Example 1 and Comparative Example 2 of the present specification, iodine heptafluoride gas is supplied to a reaction tank having “a liquid phase iodine pentafluoride containing iodine” according to the present invention to supply iodine and In the “method for producing iodine pentafluoride by reacting with iodine fluoride”, iodine pentafluoride was rapidly obtained (Example 1), whereas in the conventional method “iodine pentafluoride solution containing iodine”. It was difficult to proceed with the “method for producing iodine pentafluoride by supplying fluorine to the gas phase adjacent to the phase and reacting iodine with fluorine” (Comparative Example 2).

  Further, the present inventors have found a method for producing iodine heptafluoride by simply producing iodine heptafluoride from the obtained iodine pentafluoride.

That is, the present invention includes the following inventions 1 to 9.
[Invention 1]
A step of supplying iodine pentaheptafluoride to a reaction tank having liquid phase iodine pentafluoride containing iodine, reacting iodine with iodine pentafluoride to produce iodine pentafluoride, Method for producing iodine fluoride.
[Invention 2]
The method for producing iodine pentafluoride according to Invention 1, wherein iodine heptafluoride is supplied while stirring the inside of the reaction tank during the reaction between iodine and iodine heptafluoride.
[Invention 3]
The liquid phase iodine pentafluoride containing iodine is in a solution state containing dissolved iodine or in a state where solid iodine is dispersed and precipitated in the liquid phase. Method for producing iodine fluoride.
[Invention 4]
In the iodine pentafluoride in the liquid phase containing iodine, the content of iodine and iodine pentafluoride is expressed by the content ratio with respect to the total amount of iodine and is 0.01% by mass or more and 70% by mass or less. A method for producing iodine fluoride.
[Invention 5]
In the iodine pentafluoride in the liquid phase containing iodine, the content of iodine, iodine pentafluoride and iodine heptafluoride is represented by 0.001 mass% or more, 91 mass% or more. A method for producing iodine pentafluoride according to Inventions 1 to 4, which is included below.
[Invention 6]
A method for producing iodine pentafluoride according to Inventions 1 to 5,
A step of reacting iodine with iodine heptafluoride to obtain iodine pentafluoride,
A method for producing iodine heptafluoride, comprising the step of reacting the obtained iodine pentafluoride with fluorine gas to obtain iodine heptafluoride.
[Invention 7]
In the step of obtaining iodine heptafluoride,
The method for producing iodine heptafluoride according to Invention 6, wherein iodine pentafluoride gas and fluorine gas are supplied to and reacted with a reactor having a filler containing a metal fluoride therein.
[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]
9. The method for producing iodine heptafluoride according to Invention 7 or 8, wherein the temperature of the metal fluoride when the iodine pentafluoride gas and the fluorine gas react with each other is 150 ° C. or higher and 350 ° C. or lower.

  According to the method for producing iodine pentafluoride of the present invention, it is possible to increase the production rate of iodine pentafluoride, and moreover, easily produce iodine heptafluoride from the iodine pentafluoride produced by the production method. It can be manufactured.

It is explanatory drawing which showed the reaction apparatus which concerns on embodiment.

1. The present invention relates to a method for producing iodine pentafluoride by supplying iodine heptafluoride gas to a reaction tank containing liquid iodine pentafluoride containing iodine to react iodine with iodine heptafluoride, A method for producing iodine pentafluoride, which comprises the step of producing iodine fluoride.

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

  In the present invention, the liquid phase means a phase in which the substance is in a liquid state, and the gas phase means a phase in which the substance is in a gas state.

[Reactor]
FIG. 1 shows a reactor 10 according to an embodiment of the method for producing iodine pentafluoride of the present invention. The reactor 10 has a liquid phase (liquid) iodine pentafluoride 13 in which iodine 12 is precipitated, dispersed or dissolved in a reaction tank 11. Iodine heptafluoride can be supplied into the liquid phase 15 in the reaction tank 11, and iodine heptafluoride and iodine 12 can be reacted in the liquid phase 15 to generate iodine pentafluoride.

  At that time, iodine heptafluoride may be supplied into the liquid phase 15 or the gas phase 14. When iodine heptafluoride is supplied into the liquid phase 15, iodine heptafluoride moves at a certain rate in the gas phase 14, and when iodine heptafluoride is supplied to the gas phase 14, iodine heptafluoride is in the liquid phase. Move at a rate in 15. By blowing iodine heptafluoride into the liquid phase 15 that is iodine pentafluoride containing iodine 12, iodine heptafluoride gas can be dissolved more quickly in the liquid phase 15, and iodine heptafluoride and iodine The reaction of 12 efficiently proceeds, and the production rate of iodine pentafluoride can be increased.

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

  During the reaction of iodine 12 and iodine heptafluoride, the liquid phase 15 in the reaction tank 11 is agitated by the pump 19 or the agitator 20.

[Reaction of iodine with iodine heptafluoride]
The reaction between iodine and iodine heptafluoride occurs in the gas phase 14, in the liquid phase 15, or at 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 to the gas phase 14, and reacts with the iodine heptafluoride present in the gas phase 14. Further, iodine heptafluoride existing in the gas phase 14 moves from the gas phase 14 to the liquid phase 15 and reacts with the iodine 12 existing in the liquid phase 15. Further, iodine heptafluoride existing in the gas phase 14 reacts with iodine 12 existing in the iodine pentafluoride 13 in the liquid phase 15 at the interface between the gas phase 14 and the liquid phase 15. Further, in the liquid phase 15, iodine heptafluoride reacts with the iodine 12 present in the iodine pentafluoride 13.

  The reaction tank 11 may be cooled by a water cooling device (not shown). It is preferable to maintain the liquid phase state by maintaining the temperature of the liquid phase 15 in the reaction vessel 11 at a temperature of 10 ° C. or higher and 95 ° C. or lower during the reaction of iodine and iodine heptafluoride. If the liquid phase 15 is maintained below 10 ° C., there is a concern that the iodine pentafluoride 13 will solidify, and the energy consumption required for cooling will increase. On the other hand, when the liquid phase 15 is maintained at a temperature higher than 95 ° C., the pressure in the reaction tank 11 increases during the reaction and, in the liquid phase 15, the seven fluorines dissolved in the iodine pentafluoride 13 are added. There is a possibility that problems such as a decrease in the amount of iodine fluoride and a decrease in the production rate of iodine pentafluoride may occur. The temperature at which the liquid phase 15 is maintained is preferably 15 ° C or higher and 75 ° C or lower, and 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. When the pressure in the reaction tank 11 is less than 40 kPa, the amount of iodine heptafluoride dissolved in the iodine pentafluoride 13 decreases, and the production rate of iodine pentafluoride decreases. When the pressure in the reaction tank 11 is higher than 133 kPa, the reaction tank 11 needs to be structured to withstand the pressure. The pressure can be adjusted by the supply rate of the iodine heptafluoride gas 16, cooling of the reaction tank 11, addition of an inert gas, and the like. Although the supply rate of iodine heptafluoride depends on the size of the reaction apparatus and the scale of the reaction, it is preferable that the pressure of the gas phase 14 in the reaction tank 11 be within the above range during the reaction.

[Content of iodine and iodine heptafluoride during reaction]
The iodine 12 may be charged into the reaction tank 11 before the reaction starts, or may be intermittently or continuously supplied from the iodine supply source 17 into the reaction tank 11 at the start of the reaction and during the reaction. In the method for producing iodine pentafluoride according to the present invention, the content of iodine 12 in the reaction tank 11 is preferably represented by the content rate in which the total amount of iodine and iodine pentafluoride in the reaction tank 11 is 100% by mass. Is 0.01% by mass or more and 70% by mass or less.

  When the content of iodine is less than 0.01% by mass, the amount of iodine pentafluoride produced is small. If the content of iodine is more than 70% by mass, the reaction heat cannot be removed, which may cause local reaction or reaction runaway. In order to increase the production amount of iodine pentafluoride, the concentration of iodine 12 is preferably high, and more preferably 1 mass% or more and 60 mass% or less.

  Although it depends on conditions such as temperature and pressure, in the liquid phase 15, iodine 12 cannot be dissolved in the liquid iodine pentafluoride 13 in an amount of about 1% by mass or more. Iodine 12 that cannot be dissolved in iodine pentafluoride 13 is dispersed and precipitated in liquid phase 15 in a solid state.

  In the reaction, it is preferable to supply iodine heptafluoride gas from the iodine heptafluoride supply source 16 into the liquid phase 15 of the reaction tank 11. By supplying iodine heptafluoride into the gas phase 14, the reaction between iodine 12 and iodine heptafluoride proceeds, and iodine pentafluoride can be produced. However, it is preferable to supply iodine heptafluoride into the liquid phase 15 in order to increase the reaction efficiency of iodine 12 and iodine heptafluoride and to perform production with a high production rate of iodine pentafluoride.

  During the reaction, the content of iodine heptafluoride in the liquid phase 15 in the reaction tank 11 is represented by a content rate in which the total amount of iodine pentafluoride 13 and iodine heptafluoride in the reaction tank 11 is 100% by mass, Preferably it is 0.001 mass% or more and 91 mass% or less. When the content of iodine heptafluoride in the liquid phase 15 is less than 0.001% by mass, the amount of iodine pentafluoride produced is small. If the concentration of iodine heptafluoride is more than 91% by mass, the temperature and pressure of the reaction tank 11 may increase, which may cause local reaction or reaction runaway. More preferably, the content of iodine heptafluoride is 0.01% by mass or more and 64% by mass or less.

  The purity of the iodine heptafluoride gas supplied into the liquid phase 15 is preferably 98% by mass or more and more preferably 99% by mass or more. When the purity of iodine heptafluoride gas is low, the purity of iodine pentafluoride as a product may be reduced.

[Stirring]
During the reaction of reacting iodine 12 with iodine heptafluoride in the liquid phase 15 to obtain iodine pentafluoride, in order to avoid the occurrence of a heterogeneous reaction in which the reaction locally progresses or an excessive reaction heat is generated, It is preferable to stir 15. Examples of the method of stirring the liquid phase 15 in the reaction tank 11 include stirring by circulating the liquid phase 15 with a pump 19 or stirring with a stirrer 20 having a rotary blade. When the liquid phase 15 is agitated by the pump 19, it is preferable to introduce an inert gas having a predetermined pressure into the reaction tank 11 in order to secure the driving pressure of the pump 19. For example, the inert gas is supplied from the inert gas supply source 18. Examples of the inert gas include gases that do not react with iodine, iodine heptafluoride, and iodine pentafluoride, such as nitrogen gas, argon gas, and helium gas. As the purity of the inert gas, the purity of iodine pentafluoride, which is a product, is affected, and thus high purity is preferable, and purity of 99% by mass or more is preferable. Nitrogen gas, which is easily available, is preferable.

[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 not particularly limited in carrying out the present invention. However, the purity of iodine and iodine heptafluoride affects the purity of iodine pentafluoride produced. For example, in order to obtain 99 mass% or more of iodine pentafluoride, it is preferable to use iodine having a purity of 99 mass% or more and iodine heptafluoride.

  Further, when the iodine heptafluoride supplied from the iodine heptafluoride supply source 16 contains an inert gas, the inert gas stirs the liquid phase 15 in the reaction tank 11 by bubbling to obtain iodine 12 and iodine heptafluoride. Has the effect of removing the heat of reaction when the iodine is reacted to obtain iodine pentafluoride. However, since the pressure in the reaction tank 11 increases with time due to the increase in the partial pressure of the inert gas, it is necessary to control the pressure by installing a pressure adjusting valve or the like.

2. Method for producing iodine heptafluoride The present invention relates to the method for producing iodine pentafluoride, wherein the step of reacting iodine with iodine heptafluoride to obtain iodine pentafluoride, and the obtained iodine pentafluoride with fluorine gas. Is a method for producing iodine heptafluoride, which comprises the step of reacting with to obtain iodine heptafluoride.

  Iodine heptafluoride can be produced by reacting iodine pentafluoride obtained by the method for producing iodine pentafluoride of the present invention with fluorine gas.

  As an example of a method of reacting iodine pentafluoride with fluorine gas to obtain iodine heptafluoride, fluorine gas entrained with iodine pentafluoride gas obtained by blowing fluorine gas into a liquid of iodine pentafluoride is added to a reactor. A method of introducing iodine pentafluoride and fluorine gas to obtain iodine heptafluoride can be mentioned. Alternatively, a method in which iodine pentafluoride is vaporized by heating to form iodine pentafluoride gas and supplied to the reactor, or a method in which liquid-phase iodine pentafluoride is directly supplied to the reactor may be considered.

  When the method of supplying iodine pentafluoride gas and fluorine gas to the reactor to react them to obtain iodine heptafluoride is adopted, in the step, a reactor having a high temperature filler containing metal fluoride is used. It is preferable to supply iodine fluoride gas and fluorine gas. By using the filler, the yield of iodine heptafluoride based on iodine pentafluoride can be increased, and for example, the yield can be improved to 70% or more.

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 is a fluorinated metal. For example, the metal fluoride may be NiF ₂ , FeF ₃ , CoF ₂ , LiF, NaF, KF, CsF, MgF ₂ or CaF _2, and _two or more of these may be mixed. Considering that it is inexpensive and contributes greatly to the improvement of yield, it is preferable to use a filler containing at least one of transition metal fluorides NiF ₂ , FeF ₃ , and CoF ₂ .

  The shape of the filler to be used is not particularly limited as long as the iodine pentafluoride gas and the fluorine gas are in efficient contact with each other and the gas is not blocked during circulation. The filler is obtained, for example, by fluorinating a mesh-shaped metal piece with fluorine gas, chlorine trifluoride gas, iodine heptafluoride, or the like, in the form in which the metal fluoride is generated on the metal surface, or in the form of powder. It can be obtained by molding the metal fluoride of the above into a pellet shape.

  The temperature of the filler when the iodine pentafluoride gas and the fluorine gas are reacted to obtain iodine heptafluoride is preferably 150 ° C. or higher and 350 ° C. or lower. If the temperature of the filling is less than 150 ° C, the production rate at the time of producing iodine heptafluoride from the iodine pentafluoride gas and the fluorine gas may decrease, and if the temperature exceeds 350 ° C, the produced iodine heptafluoride may be reduced. The reverse reaction of decomposing iodine pentafluoride into fluorine may proceed. A particularly preferable temperature of the filler is 200 ° C or higher and 330 ° C or lower. For example, the reactor can be heated to a desired temperature by heating the reactor with an electric heater, steam or the like while the reactor is filled with the filler.

In the reaction of reacting iodine pentafluoride with fluorine gas to obtain iodine heptafluoride, if the reaction temperature is such that the reverse reaction is not significant, the iodine pentafluoride gas and the fluorine gas in the reactor will increase in time. The yield of iodine heptafluoride increases. The productivity of iodine heptafluoride may decrease due to the increase in residence time, and the residence time of iodine pentafluoride gas and fluorine gas in the reactor should be set considering the desired yield and productivity of iodine heptafluoride. However, various selections can be made. Considering the productivity of iodine heptafluoride, it is desirable that the residence time of iodine pentafluoride gas and fluorine gas in the reactor is short. For example, when iodine pentafluoride gas and fluorine gas are reacted at a F ₂ / IF ₅ molar ratio of 1 or more to obtain iodine heptafluoride, the temperature of the metal fluoride is 200 ° C. or higher and 330 ° C. or lower, and at least If the residence time of iodine pentafluoride gas and fluorine gas is 4 seconds or more, a yield of 80% or more can be obtained.

Flow rate ratio when introducing iodine pentafluoride gas and fluorine gas when reacting iodine pentafluoride gas and fluorine gas using a flow reactor to obtain iodine heptafluoride, or when using a closed reactor The mixing ratio of iodine pentafluoride gas to fluorine gas is preferably 1 or more in terms of the molar ratio of iodine pentafluoride to fluorine (F ₂ / IF ₅ ). In particular, when the molar ratio is 1.3 or more, a yield of iodine heptafluoride of 80% or more can be obtained when the residence time of iodine pentafluoride gas and fluorine gas is 4 seconds or more, but the molar ratio (F ₂ / IF _{When 5} ) is 35 or more, the yield of iodine heptafluoride is improved, but the economical efficiency is significantly reduced due to an increase in the amount of fluorine gas used, which is not preferable. When the molar ratio (F ₂ / IF ₅ ) is less than 1, the unreacted iodine pentafluoride increases and the yield of iodine heptafluoride may decrease.

  The pressure inside the reactor during the reaction to obtain iodine pentafluoride from iodine pentafluoride gas and fluorine gas is large in order to prevent leakage because fluorine, iodine pentafluoride and iodine heptafluoride are toxic. Atmospheric pressure is preferable, and in view of economy, 40 kPa (absolute pressure) or more is preferable.

  Examples of the present invention will be given below together with comparative examples, but the present invention is not limited to the following examples.

Example 1
As shown in FIG. 1, liquid iodine pentafluoride 13, mass 3036 g, was put into a stainless steel reaction tank 11 having a volume of 2.3 L in which the atmosphere in the tank was replaced with nitrogen, and then solid iodine 12, mass 3710 g was added. It was The concentration of iodine 12 in the liquid iodine pentafluoride 13 at the time of charging was about 55 mass% with respect to the total mass of the iodine pentafluoride 13 and the solid iodine 12. As a method of stirring the iodine pentafluoride 13 containing the solid iodine 12 in the liquid phase 15, the pump 19 was driven to circulate the liquid phase 15. Iodine heptafluoride gas is supplied from the iodine heptafluoride supply source 16 into the liquid phase 15 at a flow rate of 0.6 L / min to react the iodine heptafluoride gas with the solid iodine 12 in the iodine pentafluoride 13. , Iodine pentafluoride was obtained. During the reaction, the pressure in the reaction tank 11 was maintained at 93 kPa (absolute pressure). Further, the reaction was performed for 60 minutes while cooling the reaction vessel 11 during the reaction so that the internal temperature was 30 to 60 ° C. The amount of newly produced iodine pentafluoride other than that charged before the start of the experiment was 499 g.

Example 2
As a stirring method, instead of circulating the liquid phase 15 by the pump 19 performed in the first embodiment, the liquid phase 15 is agitated by rotating the stirrer 20 equipped with a rotary blade at a rotation speed of 100 rpm, as in the first embodiment. Similarly, iodine heptafluoride gas and solid iodine 12 were reacted. The amount of newly produced iodine pentafluoride other than that charged before the start of the experiment was 499 g.

  With any of a pump and a stirrer, by reacting iodine in iodine pentafluoride with iodine heptafluoride, it was possible to efficiently remove heat and safely and stably produce iodine pentafluoride.

Comparative Example 1
Solid iodine 12 and mass 3710 g were charged into a stainless steel reaction tank 11 having a volume of 2.3 L in which the atmosphere in the tank was replaced with nitrogen, and iodine heptafluoride gas was supplied from an iodine heptafluoride supply source 16 at 0.6 L / min. It was fed and reacted 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 start of the supply of iodine heptafluoride gas, the reaction heat was generated in the vicinity of the iodine heptafluoride gas supply port of the reaction tank 11. As the temperature increased, the supply of iodine heptafluoride gas was stopped and the reaction had to be interrupted.
Table 1 shows the production conditions and results of each example.

In Examples 1 and 2 in which iodine heptafluoride and iodine were reacted in liquid iodine pentafluoride, at a feed rate of 0.6 L / min of iodine heptafluoride gas into the liquid phase 15, local The reaction “5IF ₇ + I ₂ → 7IF ₅ ” progressed rapidly without a specific exotherm, and 499 g of iodine pentafluoride was obtained per hour. As described above, it was confirmed that the method for producing iodine pentafluoride according to the present invention can produce iodine pentafluoride in a high yield per unit time and at a high rate.

However, in Comparative Example 1 in which iodine heptafluoride is directly reacted with fixed iodine, which does not fall within the scope of the present invention, the reaction “5IF ₇ + I ₂ → 7IF ₅ ” locally generates heat and the reaction must be interrupted. Didn't get

Comparative example 2
Liquid iodine pentafluoride (13, mass: 3036 g) was placed in a stainless steel reaction tank (11) having a volume of 2.3 L in which the atmosphere in the tank was replaced with nitrogen, and solid iodine (12) and mass (3710 g) were added. The concentration of solid iodine 12 with respect to the combined mass of iodine pentafluoride 13 and solid iodine 12 at the time of charging was about 55 mass%. The liquid phase 15 was stirred with a stirrer equipped with a rotary blade at a rotation speed of 100 rpm.

  Under stirring, fluorine gas diluted to 70% by volume with nitrogen gas was supplied to the gas phase 14 of the reaction tank 11, and the reaction of obtaining iodine pentafluoride from iodine and fluorine gas was started. The pressure in the reaction tank 11 during the reaction was kept at 93 kPa (absolute pressure) by the pressure control valve. Further, the temperature of the reaction tank 11 during the reaction was cooled to 30 to 60 ° C., and the reaction was performed for 60 minutes.

  The concentration of the fluorine gas discharged from the pressure regulating valve was about 70 as a result of the spectroscopic analysis by UV / visible / near infrared spectroscopy using a spectrophotometer UV-Vis (manufactured by Hitachi High-Tech Science Co., Ltd., model U2810). It remained in volume%, the fluorine gas was hardly consumed, and the reaction of obtaining iodine pentafluoride from iodine and fluorine gas did not proceed. The amount of newly produced iodine pentafluoride other than that charged before the start of the experiment was only 0.0025 g.

Example 3
Using the iodine pentafluoride obtained in Example 1, iodine heptafluoride was synthesized. The specific manufacturing procedure is as follows.

Nickel fluoride (NiF ₂ ) as a metal fluoride (purity 99%, Apollo Sc
Authentic Limited) was pressed into pellets (size: 4 mm × 4 mm × 2 mm). A bright annealing tube made of nickel (inner diameter 22.1 mm, length 0.3 m) equipped with an electric heater and a pressure gauge, which was used as a reactor, was filled with pelletized nickel fluoride (48 g, 0.5 mol). By heating the bright annealing tube with an electric heater, the temperature of the pellets as a filling material was set to 270 ° C. At this temperature, a mixed gas of fluorine (F ₂ ) and iodine pentafluoride (IF ₅ ) (molar ratio (F ₂ / IF ₅ ) = 30.3 (F ₂ concentration 96.8% by volume, IF ₅ concentration 3. 20% by volume)) was introduced from one side (inlet) of both ends of the bright annealing tube and discharged from the other side (outlet).

At this time, the pressure in the bright annealing tube was set to 66.7 kPa (absolute pressure), and the flow rate of the mixed gas was set to flow at 1730 cm ³ / min (residence time 4 seconds) for 1 hour. Further, the gas from the reactor outlet was introduced into the cooling collector during the flow of the mixed gas. Iodine heptafluoride and iodine pentafluoride were cooled and collected by using liquid argon (temperature: -186 ° C) as a refrigerant of the cooling collector. After the completion of the flow of the mixed gas, the mass of the collected matter in the cooling collector and the Fourier transform infrared spectrophotometer (FT-IR) (manufactured by Shimadzu Corporation, product name, Prestige 21) were used to measure iodine and pentafluoride. The composition of iodine fluoride was analyzed. Based on the results of mass measurement and composition analysis, the yield relative to the theoretical amount of iodine pentafluoride based on the amount of iodine pentafluoride IF ₅ supplied was calculated. The iodine yield was 99.8%.

10 reactor 11 reaction tank (cooled by a cooler)
12 Solid iodine 13 Iodine pentafluoride (Iodine is dissolved)
14 Gas phase 15 Liquid phase (iodine pentafluoride)
16 Source of iodine heptafluoride 17 Source of iodine 18 Source of inert gas 19 Pump 20 Stirrer

Claims (9)

  A step of supplying iodine pentaheptafluoride to a reaction tank having liquid phase iodine pentafluoride containing iodine, reacting iodine with iodine pentafluoride to produce iodine pentafluoride, Method for producing iodine fluoride.   The method for producing iodine pentafluoride according to claim 1, wherein iodine heptafluoride is supplied while stirring the inside of the reaction tank during the reaction between solid iodine and iodine heptafluoride.   The iodine pentafluoride in the liquid phase containing iodine is in a solution state containing dissolved iodine, or in a state in which solid iodine is dispersed and precipitated in the liquid phase. The method for producing iodine pentafluoride described.   The iodine-containing liquid pentafluoride containing iodine in an amount of 0.01% by mass or more and 70% by mass or less in terms of content of iodine and iodine pentafluoride with respect to the total amount of iodine. 4. The method for producing iodine pentafluoride according to any one of 3 above.   In the iodine pentafluoride in the liquid phase containing iodine, the iodine heptafluoride is contained in an amount of 0.001% by mass or more and 91% by mass or less, as expressed by the content of iodine pentafluoride and iodine heptafluoride. The method for producing iodine pentafluoride according to any one of claims 1 to 4. The method for producing iodine pentafluoride according to any one of claims 1 to 5,
A step of reacting iodine with iodine heptafluoride to obtain iodine pentafluoride,
A method for producing iodine heptafluoride, comprising the step of reacting the obtained iodine pentafluoride with fluorine gas to obtain iodine heptafluoride. In the step of obtaining iodine heptafluoride,
The method for producing iodine heptafluoride according to claim 6, wherein iodine pentafluoride gas and fluorine gas are supplied and reacted in a reactor having a filler containing a metal fluoride therein. The method for producing iodine heptafluoride according to claim 7, wherein the metal fluoride contains at least one compound selected from the group consisting of NiF ₂ , FeF ₃ , and CoF ₂ .   The method for producing iodine heptafluoride according to claim 7 or 8, wherein the temperature of the metal fluoride when the iodine pentafluoride gas and the fluorine gas react is 150 ° C or higher and 350 ° C or lower. .

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