JP2008100881A - Production method of iodine pentafluoride - Google Patents

Abstract

[PROBLEMS] To avoid the problems of conventional iodine pentafluoride production methods as much as possible, and gently carry out the reaction between fluorine and iodine, resulting in safer and more productive results. A method capable of producing excellent iodine pentafluoride is provided.
In a method for producing iodine pentafluoride by reacting fluorine and iodine, a molten iodine phase and an iodine pentafluoride phase positioned above and adjacent thereto are formed, and the iodine pentafluoride phase is formed. Fluorine is supplied to the gas phase and / or iodine pentafluoride phase adjacent and above it.
[Selection] Figure 1

Description

The present invention relates to a method for producing iodine pentafluoride (IF ₅ ) by reacting iodine with fluorine. Iodine pentafluoride is useful as a raw material for producing an intermediate of a highly reactive fluorinating agent or fluorine-containing compound.

  Examples of a method for producing iodine pentafluoride by reaction of iodine and fluorine include, for example, a counter-current contact method between iodine and fluorine dissolved in iodine pentafluoride (see Patent Document 1), molten iodine or slurry form. There is a method of bubbling fluorine into iodine (see Patent Documents 2 and 3).

  In these methods, fluorine is supplied into the liquid phase, and therefore, sublimation of iodine is promoted by entrainment with a gas such as nitrogen and unreacted fluorine used as a dilution gas. There is a risk that iodine solidifies and adheres and eventually the piping is blocked. Also, it is difficult to raise the temperature to avoid it.

  In addition, iodine pentafluoride has a large heat of formation of 920 kJ / mol, and iodine that solidifies and adheres to the piping reacts with fluorine to cause a local increase in temperature, which is not necessarily industrial in terms of safety. It is not a useful method.

  Furthermore, since fluorine and iodine are very reactive, if fluorine is brought into contact with high-concentration iodine such as molten iodine or slurry iodine, they may react explosively. As a result, fluorine supply There is a risk of iodine flowing back to the piping side. When iodine flows backward to the fluorine distribution supply pipe side, fluorine and iodine react vigorously in the fluorine supply pipe, and there is a risk that the temperature rises rapidly and damages the pipe.

  In particular, in the reaction heat removal by sensible heat using an indirect heat exchanger (such as an outer jacket) generally used for removing reaction heat in the reactor, the amount of heat that can be effectively removed is too much compared to the reaction heat. Therefore, it is difficult to control the reaction temperature, and when scaled up, there is a risk of runaway reaction and further explosion.

  As another manufacturing method, these are reacted with molten iodine through fluorine gas to produce a vapor mixture containing iodine pentafluoride and iodine, and the vapor is produced in the presence of liquid iodine pentafluoride already produced. There is a method of reacting the mixture with fresh fluorine gas to further generate iodine pentafluoride (see Patent Document 4).

This method has the advantage that heat of reaction can be used to maintain iodine in a liquid state, but fluorine gas is rich in reactivity, so runaway reaction due to intense heat generation due to the reaction, advanced reaction that can avoid explosion Control technology is required. Further, since there is a risk of pipe clogging due to sublimable iodine, it is not necessarily an industrially satisfactory method.
U.S. Pat. No. 3,367,745 JP-A-54-65196 British Patent No. 1326130 JP 58-145602 A

  As described above, conventionally known methods for producing iodine pentafluoride are not necessarily satisfactory from the viewpoint of industrial practicality. Therefore, the problem to be solved by the present invention is to solve the above-mentioned various problems as much as possible by replacing the conventional method using molten iodine with higher productivity of iodine pentafluoride. It is to provide a new industrial manufacturing method.

  In order to solve the above-mentioned problems, the inventors have made extensive studies, and as a result, formed a molten iodine phase and an iodine pentafluoride phase located above (adjacent to the upper side), and an iodine pentafluoride phase. The present invention has been completed by using a reactor constituting a reaction system for supplying fluorine to the gas phase and / or iodine pentafluoride phase located adjacent to and above the gas phase.

  The supply of fluorine to the reactor is usually carried out continuously, but fluorine may be intermittently supplied in an amount corresponding to the amount of fluorine consumed by the reaction. The iodine pentafluoride phase and iodine phase present in the reactor may be kept in the reactor as they are, or an amount of iodine corresponding to the amount of iodine consumed by the reaction is continuously added to the molten iodine phase. Or you may supply intermittently. Furthermore, since iodine pentafluoride is produced by the reaction, iodine pentafluoride in an amount corresponding to the amount of iodine pentafluoride produced can be removed continuously or intermittently from the iodine pentafluoride phase of the reactor. Good.

When supplying fluorine to the iodine pentafluoride phase and / or the gas phase located above and adjacent thereto as described above, the fluorine and iodine come into contact with each other to react with iodine pentafluoride as follows: Produces:
(A) a gas phase reaction in which iodine that was present in the iodine pentafluoride liquid phase moves from the liquid phase to the gas phase and reacts with the fluorine present in the gas phase;
(B) A liquid phase reaction in which fluorine existing in the gas phase moves from the gas phase into the iodine pentafluoride liquid phase and reacts with the iodine present in the iodine pentafluoride liquid phase. ;
(C) Reaction at the interface between the gas phase and the liquid phase, in which fluorine present in the gas phase contacts and reacts with iodine present in the iodine pentafluoride liquid phase.

  When supplying fluorine to the gas phase, reaction (a) takes place preferentially, and the fluorine supplied to the gas phase is preferably consumed mostly, and the majority of the remaining fluorine is reacted (b) and / Or consumed by reaction (c).

  When supplying fluorine to the iodine pentafluoride phase, reaction (b) occurs first and the supplied fluorine is consumed, and the remaining fluorine is consumed by reaction (a). Depending on the relative relationship between the amount of fluorine supplied and the amount of iodine present in the iodine pentafluoride phase, it is determined which reaction (a) or reaction (b) mainly occurs. In addition, reaction (c) also takes place.

  It should be noted that the mechanism of movement of fluorine in the vapor phase into the iodine pentafluoride liquid phase and the mechanism of movement of iodine in the iodine pentafluoride liquid phase into the gas phase are not particularly limited. For example, as a result of diffusion, evaporation, sublimation, etc. of fluorine or iodine.

  Accordingly, the present invention provides a method for producing iodine pentafluoride by reacting fluorine and iodine, which method forms a molten iodine phase and an iodine pentafluoride phase located above and adjacent thereto. And fluorine is supplied to the gas phase and / or iodine pentafluoride phase adjacent to and above the iodine pentafluoride phase. When fluorine is supplied in this manner, at least reaction (a) and / or reaction (b) among the above reactions (a) to (c), fluorine and iodine are brought into contact with each other, and iodine pentafluoride is reacted. Produces. Of course, other reactions (c) may occur simultaneously.

  In this specification, the term “gas phase” does not include bubbles present in the liquid phase, and therefore supplying fluorine into the liquid phase by bubbling means “supplying fluorine into the gas phase”. Does not correspond to “Supplying fluorine to the gas phase” means supplying fluorine to the gas phase existing above and adjacent to the liquid phase, that is, supplying fluorine to the space above the liquid phase. This means that the fluorine constitutes the gas phase (along with the inert gas described below if necessary).

  In the production method of the present invention, the iodine pentafluoride phase contains iodine dissolved therein. This is because iodine diffuses from the molten iodine phase and moves to the iodine pentafluoride phase because the iodine pentafluoride phase is adjacent to the molten iodine phase. In a preferred embodiment, the iodine pentafluoride phase contains an amount of iodine substantially corresponding to or near saturation solubility. Specifically, the iodine pentafluoride phase is preferably 2.0 to 5.0% by mass, more preferably 3.0 to 5.0% by mass, for example 4.0 to 5%, based on the mass of the entire liquid phase. Contains 0% by weight iodine. When the amount is less than 2.0% by mass, the reaction rate may decrease, and thus productivity may decrease. When the amount exceeds 5.0% by mass, iodine pentafluoride contained in the exhaust gas may increase. There is.

  Iodine pentafluoride used in the production method of the present invention does not adversely affect the reaction between fluorine and iodine that generate iodine pentafluoride, and is a medium that takes in iodine from the molten iodine phase, or iodine from the molten iodine phase to the gas phase. Can be suitably used as a medium for transporting the liquid.

  According to the iodine pentafluoride production method of the present invention, only the amount of iodine dissolved in the iodine pentafluoride phase is involved in the reaction in the iodine pentafluoride phase and / or in the gas phase. For this reason, there exists an advantage that reaction control can be implemented very efficiently, without the needless iodine participating in reaction. Further, by setting the reaction temperature to be equal to or higher than the melting point of iodine, the reaction rate can be increased by the effect of increasing the temperature and the effect of increasing the solubility of iodine. Even if the reaction temperature is increased, iodine pentafluoride is located at the upper position, so that unreacted iodine is prevented from flowing out from the reactor to the piping that discharges the gas. The possibility of adhesion is reduced, and the backflow of iodine to the fluorine supply pipe and the problems associated therewith can be avoided.

  Furthermore, iodine pentafluoride produced by the reaction is included in the iodine pentafluoride phase. Therefore, the iodine pentafluoride phase containing the produced iodine pentafluoride can be used as it is according to the standard of the target iodine pentafluoride. In that case, a rectifying apparatus for separating the produced iodine pentafluoride can be omitted. As a result, the apparatus for carrying out the iodine pentafluoride production method of the present invention is simplified as a whole, which is economically advantageous. It is.

BEST MODE FOR CARRYING OUT THE INVENTION

  In one aspect of the method for producing iodine pentafluoride according to the present invention, a molten iodine phase as a lower phase and an iodine pentafluoride liquid phase located thereon are allowed to exist in the reactor as an upper phase, Fluorine, preferably continuously, is fed into the phase and / or gas phase adjacent to it (ie, either or both) to react iodine and fluorine.

  Although it is not necessary to supply fluorine after once supplying fluorine to the reactor, it is generally preferable to supply fluorine continuously or intermittently. For the molten iodine phase and iodine pentafluoride phase, once both phases are present in the reactor, the components constituting these phases may not be added thereafter. In another aspect, iodine consumed by the reaction (solid state, preferably molten) may be added to the iodine phase intermittently or continuously. Further, since the amount of iodine pentafluoride phase increases due to the iodine pentafluoride produced, a part of the iodine pentafluoride phase may be taken out continuously or intermittently as necessary. The extracted iodine pentafluoride phase can be purified to obtain iodine pentafluoride having a product specification.

In one aspect of the method for producing iodine pentafluoride of the present invention,
1) a step of forming a molten iodine phase and an iodine pentafluoride phase located above and adjacent thereto in a mixing tank;
2) supplying fluorine to the gas phase and / or iodine pentafluoride phase, and 3) adding iodine to the molten iodine phase as needed, corresponding to the amount of iodine pentafluoride generated in the reactor And a step of removing iodine pentafluoride in an amount corresponding to the amount of iodine pentafluoride generated from the iodine pentafluoride phase.

The purification process of the iodine pentafluoride phase may be carried out by any appropriate method, for example, by rectifying under normal pressure.

  In one aspect, the method for producing iodine pentafluoride according to the present invention may be carried out batchwise for supplying fluorine and for supplying iodine constituting the iodine phase, and in another aspect, continuous supply for fluorine. The iodine supply may be carried out batchwise (so-called semi-batch method), and when the reaction proceeds by a predetermined amount, for example, the supply of fluorine gas is stopped and the iodine pentafluoride phase is removed from the reactor. And iodine pentafluoride can be recovered.

  In yet another embodiment, all feeds may be carried out continuously. In this case, it is preferable to supply a stoichiometric amount or more of fluorine with respect to iodine. For example, at least 5 moles of fluorine, preferably 5 to 6 times as much fluorine, are supplied per mole of iodine. Regarding iodine pentafluoride constituting the iodine pentafluoride phase, since the product is iodine pentafluoride, the amount of iodine pentafluoride present in the reactor is increased. Therefore, the iodine pentafluoride phase may be taken out from the reactor, or if there is no problem in increasing iodine pentafluoride, it is not always necessary to remove the iodine pentafluoride phase from the reactor. The iodine pentafluoride phase taken out can be taken out to recover iodine pentafluoride.

  In another aspect of the method for producing iodine pentafluoride according to the present invention, iodine is melted in advance in a melting tank to prepare molten iodine, and the prepared molten iodine is continuously or intermittently added to the lower phase of the reactor. To supply. For this melting, a stirrer may be provided in the melting tank. In another embodiment, solid iodine may be fed to the lower phase of the reactor.

  In another aspect of the iodine pentafluoride production method of the present invention, the iodine pentafluoride liquid phase adjacent to the gas phase supplying fluorine may further contain hydrogen fluoride. When the iodine pentafluoride phase contains hydrogen fluoride, the amount of iodine that can be dissolved from the molten iodine phase into the iodine pentafluoride phase can be increased, and the reaction proceeds more efficiently. For example, the solubility of iodine in iodine pentafluoride at 30 ° C. is 0.6% by mass, and it is fluorinated on the basis of the total amount of iodine pentafluoride phase (ie, based on the total amount of iodine pentafluoride, hydrogen fluoride and iodine). When the concentration of hydrogen is 1.0% by mass, the solubility (saturated concentration) of iodine is 2.0% by mass; on the other hand, at 120 ° C., the solubility of iodine in iodine pentafluoride is 2.7% by mass, When the concentration of hydrogen fluoride is 1.0 mass% on the basis of the total amount of iodine pentafluoride phase (that is, based on the total amount of iodine pentafluoride, hydrogen fluoride and iodine), the solubility (saturation concentration) of iodine is 4. 0% by mass, corresponding to about twice that at 30 ° C. In this case, since the concentration of the reactant increases, the reaction efficiency increases dramatically in combination with the effect of increasing the reaction temperature. Hydrogen fluoride may be supplied to the reaction system by any appropriate method. For example, it may be directly supplied to the iodine pentafluoride liquid phase to be dissolved, or it may be supplied as a gas to the gas phase adjacent to the iodine pentafluoride liquid phase, together with fluorine gas as necessary. You may supply by making it transfer to.

  In the production method of the present invention, when the batch type is adopted for the iodine pentafluoride phase (therefore, the iodine pentafluoride phase is not extracted), as the reaction proceeds, iodine pentafluoride in the iodine pentafluoride phase Since the amount increases, the concentration of hydrogen fluoride in the iodine pentafluoride phase gradually decreases when hydrogen fluoride is not added on the way. Even considering this decrease, the concentration of hydrogen fluoride contained in the iodine pentafluoride phase of the reactor during the reaction period is based on the total amount of iodine pentafluoride phase (ie iodine pentafluoride, hydrogen fluoride and For example, it is preferably maintained at 1.0 to 10% by mass, particularly 3.0 to 5.0% by mass based on the total amount of iodine. When the concentration of hydrogen fluoride exceeds 10% by mass, the concentration of fluorine that can be dissolved in the iodine pentafluoride phase may be lowered, and as a result, there is a problem that the reactivity is lowered. In the case of carrying out the production method in a steady state, the concentration of hydrogen fluoride becomes substantially constant, but even in that case, the hydrogen fluoride contained in the iodine pentafluoride phase of the reactor is The above-mentioned range is preferable.

  The conditions for reacting fluorine and iodine (for example, conditions such as reaction temperature and pressure) are not particularly limited, and conditions conventionally employed for this reaction are also employed in the production method of the present invention. it can. However, it is particularly preferable to employ conditions where iodine pentafluoride does not boil.

  Specifically, as the temperature condition, a temperature that is higher than the temperature at which iodine can exist as a liquid and lower than the temperature at which the iodine pentafluoride phase boils (usually near the boiling point of iodine pentafluoride) can be adopted. Reaction temperatures within the range of 114 ° C to 130 ° C, preferably 118 ° C to 125 ° C, more preferably 120 ° C to 123 ° C can be used. When iodine pentafluoride boils, there is a greater possibility of iodine adhering to the gas phase discharge piping of the reactor. The reaction pressure is preferably selected in relation to the reaction temperature so that no boiling of the iodine pentafluoride phase occurs. Accordingly, it is usually sufficient that the pressure allows iodine pentafluoride to exist as a liquid phase in the reactor. For example, it can be carried out at a pressure of 0.14 to 0.30 MPa (absolute pressure), and may usually be carried out under a pressure slightly higher than atmospheric pressure.

  The reaction temperature / pressure combinations that can be employed are, for example, 114 ° C to 130 ° C / 0.14 MPa to 0.30 MPa (absolute pressure), preferably 115 ° C to 130 ° C / 0.16 to 0.23 MPa (absolute pressure), and more. Preferably, it is 118 to 125 ° C / 0.17 to 0.21 MPa (absolute pressure), for example, 120 to 123 ° C / 0.18 to 0.20 MPa (absolute pressure).

  The mass ratio of iodine and iodine pentafluoride constituting the liquid phase (molten iodine phase and iodine pentafluoride phase) in the reactor is not particularly limited. For example, it is preferable to operate so that the amount of iodine is at least 10% by mass or more, preferably at least 30% by mass or more, for example, 40 to 60% by mass.

  As for the reactor used in the production method of the present invention, the apparatus conventionally employed for this reaction can also be used in the production method of the present invention. Usually, a generally used tank reactor, a reactor with a condenser, or the like may be used. The reactor preferably has a stirring device that promotes mixing of the iodine pentafluoride phase. The stirring device is preferably a stirrer that can make the iodine concentration distribution inside the iodine pentafluoride phase more uniform, and has the effect of renewing the interface between the molten iodine phase and the iodine pentafluoride phase. The type is particularly preferred, and the type that greatly disturbs the interface is less preferred.

  The fluorine supplied in the production method of the present invention is preferably supplied in a state diluted with a gas that is inert to the reaction. Usually, it is diluted with nitrogen, helium, argon, hydrogen fluoride, carbon tetrafluoride, sulfur hexafluoride, perfluoroethane or the like. Although the dilution rate is not particularly limited, for example, the dilution is performed such that the volume% of fluorine is 10 to 95% based on the total amount of the supplied gas. If it is smaller than this range, iodine pentafluoride or iodine may flow out of the reactor. If it is larger than this range, iodine pentafluoride or iodine may flow back to the fluorine supply line. there is a possibility. In a preferred embodiment, the volume% of fluorine contained in the supplied gas is 20 to 90%. In a more preferred embodiment, the volume% of fluorine contained in the supplied gas is 30 to 90%, particularly 50 to 90%. .

  In addition, it is preferable to use hydrogen fluoride as a diluent gas because the solubility of iodine in iodine pentafluoride is increased and the reactivity is improved. However, iodine pentafluoride, which is the target product, is obtained from the iodine pentafluoride phase. In order to recover, separation / removal of hydrogen fluoride is required.

  In another embodiment, fluorine and inert gas may be separately supplied to the reactor gas phase so that the fluorine is diluted in the reactor gas phase. Also in this case, it is preferable to supply the fluorine so that the ratio of fluorine is in the above range with respect to the total amount of fluorine and inert gas to be supplied.

  In addition, when diluting and supplying fluorine with an inert gas, it is preferable that the reactor has a cooler in the middle of a pipe for discharging the gas phase, and the cooler is a dilution exhausted from the reactor. Iodine pentafluoride accompanying the gas (including unreacted fluorine) is condensed and recovered. Depending on the amount of fluorine contained in the diluted gas to be discharged, it is preferable to recycle and reuse the diluted gas containing fluorine.

  In yet another embodiment, an iodine pentafluoride phase in which iodine is dissolved is prepared separately in the absence of a molten iodine phase at the bottom of the reactor and fed to the reactor to provide an iodine pentafluoride phase and It can also be carried out by supplying fluorine to the gas phase located adjacent to and above the iodine pentafluoride phase.

  Next, the production method of the present invention will be described in more detail with reference to the flow sheet of FIG. 1 schematically showing an example of the production method of iodine pentafluoride of the present invention. In the production method of the present invention, a molten iodine phase 12 as a lower phase and an iodine pentafluoride phase 14 as an upper phase thereon are formed in the reactor 10. For example, iodine and iodine pentafluoride are put into a reactor in predetermined amounts, and heated to a temperature lower than the boiling point of iodine pentafluoride under slight pressure to melt iodine.

  Since the specific gravity of iodine is greater than the specific gravity of iodine pentafluoride, a molten iodine phase is formed below the iodine pentafluoride phase by placing more iodine in the reactor than the saturation solubility of iodine pentafluoride. . By maintaining the state in which both phases are in contact, iodine moves to the iodine pentafluoride phase 14 and dissolves, and then moves to the gas phase 16. Some iodine pentafluoride also moves to the molten iodine phase 12. At this time, it is preferable to stir the iodine pentafluoride phase 14 with the stirrer 20.

  After the two phases are separated in this way, the gas phase 16 located above the iodine pentafluoride phase 14 is diluted with fluorine, preferably with nitrogen and / or hydrogen fluoride, for example, as shown. Supply the generated fluorine. In addition to or instead of such supply of fluorine, fluorine may be supplied to the iodine pentafluoride phase 14. When supplying fluorine to both the gas phase and iodine pentafluoride phase, preferably 10 to 100%, more preferably 50 to 100%, for example 80 to 100%, is supplied to the gas phase based on the total amount of fluorine to be supplied. The remainder is fed to the iodine pentafluoride phase.

  Fluorine supplied to the gas phase 16 mainly reacts with iodine present in the gas phase 16, and part of the fluorine moves into the iodine pentafluoride phase 14 and reacts with iodine present there. obtain. In addition, fluorine in the gas phase 16 and iodine in the iodine pentafluoride phase 14 can also react at the gas-liquid interface 18.

  The fluorine supplied to the iodine pentafluoride phase 14 reacts with iodine present in the iodine pentafluoride phase 14, and the remaining fluorine moves into the gas phase 16 and reacts with iodine present therein. Can do. In addition, fluorine in the gas phase 16 and iodine in the iodine pentafluoride phase 14 can also react at the gas-liquid interface 18.

  In one aspect of the method for producing iodine pentafluoride of the present invention, iodine constituting the molten iodine phase 12 may be prepared, for example, in the melting tank 30. Solid iodine is added to the melting tank 30 and heated. The obtained molten iodine is charged into the molten iodine phase 12 of the reactor 10 (note that it may be supplied via the iodine pentafluoride phase 14 as shown in the drawing or directly to the molten iodine phase 12). Prior to the reaction, the molten iodine prepared in advance as described above may be supplied to the reactor 10 as a lower phase, and then the molten iodine may not be supplied to the reactor 10. In this case, since fluorine is continuously supplied to the gas phase, iodine pentafluoride is produced by a semi-batch method. When fluorine is first supplied to the gas phase and not supplied thereafter, iodine pentafluoride is produced in a batch mode.

In another embodiment, fluorine and molten iodine are continuously or intermittently supplied to the reactor 10, and in this case, iodine pentafluoride is produced continuously. In this case, since iodine pentafluoride contained in the reaction system gradually increases, a part of the iodine pentafluoride phase 14 is extracted from the reactor 10 by a pump, and iodine pentafluoride generated therefrom is recovered from the reaction system. It is preferable to do this. This recovery may be performed by any suitable method. For example,
A method such as separation / recovery by distillation can be employed.

  In the illustrated embodiment, the fluorine to be supplied is supplied to the gas phase in a state diluted with nitrogen. In the reactor, it is preferred that fluorine react with iodine as much as possible, and substantially at least 80%, preferably at least 90%, more preferably at least 95%, eg at least 99% of the supplied fluorine reacts with iodine. To do. Unreacted fluorine (usually a small amount) and nitrogen are discharged from the reactor 10 through the gas discharge pipe 24. The pipe 24 is provided with a cooler 26 for collecting the accompanying iodine pentafluoride.

  A fluororesin (PFA) tube having an internal volume of 10 mL was used as the reactor. A reactor was charged with 3.8 g of iodine and 6.25 g of iodine pentafluoride, and the temperature in the tube was 120 ° C. with the pressure in the tube being 0.2 MPa (gauge pressure). The metal tube attached to the outside of the tube was heated to melt iodine, and an iodine pentafluoride phase was formed on the molten iodine phase.

  Next, fluorine gas diluted to 33 vol% with nitrogen was introduced into the gas phase part of the tube at a flow rate of 10 cc / min and reacted until the iodine pentafluoride phase became colorless and transparent. This reaction was performed at 0.2 MPa (gauge pressure) to suppress boiling of the liquid in the reactor.

  The gas discharged from the reactor through the gas phase discharge pipe was passed through a mixed solution of alkali and reducing agent to absorb and remove unreacted fluorine gas. When the iodine pentafluoride phase in the tube was analyzed by 19F-NMR, iodine pentafluoride was 100 mol%. There was no solidification or adhesion due to sublimated iodine on the wall surface of the gas phase portion of the tube, and the gas phase exhaust piping was not blocked.

Comparative Example 1

  Example 1 was repeated in the same manner except that fluorine gas was charged into the molten iodine phase. Immediately after the start of the reaction, the temperature in the tube suddenly increased, the tube burst and the reaction could not be continued.

Comparative Example 2

  Example 1 was repeated except that the reaction was carried out at a pressure of 0.1 MPa (absolute pressure) by pressurizing to 0.1 MPa (absolute pressure) with nitrogen. During the reaction, the iodine pentafluoride phase in the tube was in a boiling state. The reaction was continued until the iodine pentafluoride phase became colorless and transparent. The time required to become transparent increased twice as compared with Example 1. When the iodine pentafluoride phase in the tube was analyzed by 19F-NMR, iodine pentafluoride was 100 mol%. On the wall surface of the gas phase portion of the tube, there was about 0.1 g of iodine that sublimated and solidified and adhered, but the gas phase discharge piping was not blocked.

  In this example, the reaction was carried out using a metal autoclave (manufactured by SUS316, capacity 200 mL) as a reactor. A SUS316 condenser was attached to the autoclave. The reactor is charged with 70 g of iodine and 300 g of iodine pentafluoride, and the reactor is heated while cooling by flowing a cooling liquid at 20 ° C. into the condenser, and nitrogen pressure is applied so that the internal temperature becomes about 120 ° C. The pressure control valve was controlled so that the internal pressure was about 0.2 MPa (absolute pressure).

Fluorine gas diluted with nitrogen gas (F ₂ concentration 90 vol%) was charged into the gas phase part of the reactor at a flow rate of 100 Ncc / min. The non-condensable gas discharged from the top of the condenser was guided to the detoxification tower and washed with a mixed aqueous solution of potassium hydroxide and potassium sulfite. When the non-condensable gas was analyzed with an ultraviolet-visible spectrophotometer, the conversion of fluorine gas was 95 mol%.

  After the reaction was continued for 6 hours, the supply of fluorine gas was stopped, and the liquid remaining in the reactor was collected. As a result, all the iodine in the reactor was consumed and the liquid was colorless and transparent. When this liquid was analyzed by 19F-NMR, iodine pentafluoride was 100 mol%.

  Example 2 was repeated except that fluorine gas diluted with nitrogen was bubbled into the iodine pentafluoride phase of the reactor. The iodine pentafluoride phase was bubbled at a flow rate of 100 Ncc / min. When the non-condensed gas was analyzed with an ultraviolet-visible spectrophotometer, the conversion of fluorine gas was 98 mol%.

  After the reaction was continued for 6 hours, the supply of fluorine gas was stopped, and the liquid remaining in the reactor was recovered, and it was a colorless and transparent liquid. When analyzed by 19F-NMR, it was found that iodine pentafluoride was 100 mol%. About 1 g of iodine solidified and adhered by sublimation adhered to the inside of the upper lid of the reactor.

Example 2 was repeated, except that fluorine gas diluted with hydrogen fluoride (F ₂ concentration 90 vol%) was supplied to the gas phase portion of the reactor instead of fluorine gas diluted with nitrogen. When the non-condensed gas was analyzed with an ultraviolet-visible spectrophotometer, the conversion of fluorine gas was 98 mol%.

  After the reaction was continued for 6 hours, the supply of the raw material gas was stopped and the liquid remaining in the reactor was recovered. As a result, all the iodine in the reactor was not consumed, and the liquid was colorless and transparent. When this liquid was analyzed by 19F-NMR, it was found that iodine pentafluoride was 100 mol%.

Comparative Example 4

In this comparative example, the reaction was performed using a metal autoclave (manufactured by SUS316, capacity 200 mL) as a reactor. A SUS316 condenser was attached to the autoclave. 70 g of iodine and 300 g of iodine pentafluoride were charged into the reactor, and the outside of the reactor was cooled so that the temperature inside the reactor became about 30 ° C. while cooling by flowing a 20 ° C. cooling liquid through the condenser.

  Fluorine gas diluted with nitrogen gas (concentration 90 vol%) was charged into the gas phase part of the reactor at a flow rate of 100 Ncc / min. The non-condensable gas discharged from the top of the condenser was guided to the detoxification tower and washed with a mixed aqueous solution of potassium hydroxide and potassium sulfite. When the non-condensed gas was analyzed with an ultraviolet-visible spectrophotometer, the conversion of fluorine gas was 85 mol%.

It is a flow sheet which shows typically an example of a manufacturing method of iodine pentafluoride of the present invention.

Explanation of symbols

10 ... reactor, 12 ... molten iodine phase, 14 ... iodine pentafluoride phase, 16 ... gas phase,
18 ... Gas phase-liquid phase interface, 20 ... Stirrer, 24 ... Gas phase discharge piping,
26 ... Cooler (condenser), 30 ... Melting tank.

Claims (6)

A method for producing iodine pentafluoride by reacting fluorine and iodine,
A molten iodine phase and an iodine pentafluoride phase located above and adjacent thereto are formed, and fluorine is supplied to the gas phase and / or iodine pentafluoride phase located adjacent to and above the iodine pentafluoride phase. A method for producing iodine pentafluoride, comprising:   The method for producing iodine pentafluoride according to claim 1, wherein the method is carried out under conditions where the iodine pentafluoride phase does not boil.   The method for producing iodine pentafluoride according to claim 1 or 2, wherein fluorine is supplied in a state diluted with an inert gas.   The method for producing iodine pentafluoride according to any one of claims 1 to 3, wherein the iodine pentafluoride phase contains 2.0 to 5.0 mass% iodine based on the mass of the entire liquid phase. .   The method for producing iodine pentafluoride according to any one of claims 1 to 4, wherein the iodine pentafluoride phase contains 1.0 to 10% by mass of hydrogen fluoride based on the total mass. . 1) a step of forming a molten iodine phase and an iodine pentafluoride phase located above and adjacent thereto in a mixing tank;
2) supplying fluorine to the gas phase and / or iodine pentafluoride phase, and 3) adding iodine to the molten iodine phase as needed, corresponding to the amount of iodine pentafluoride generated in the reactor A method for producing iodine pentafluoride, comprising a step of extracting iodine pentafluoride in an amount corresponding to the amount of iodine pentafluoride produced from the iodine pentafluoride phase.

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