JPWO2009035110A1 - Method for producing fluoroalkyl iodide - Google Patents

Abstract

Provided is a method for producing a fluoroalkyl iodide with high selectivity and high productivity of a fluoroalkyl iodide (telomer) having a desired degree of polymerization. When a compound represented by the following formula (2) is added to a compound represented by the following formula (1) in the presence of a radical initiator to obtain a compound represented by the following formula (3), radical initiation As the agent, a compound represented by the following formula (4) is used. RfI (1), CF2 = CF2 (2), RfCF2CF2I (3), {F (CF2) xCOO} 2 (4). However, Rf is a fluoroalkyl group having 2 to 16 carbon atoms, and x is an even number of 2 to 14.

Description

  The present invention relates to a method for producing a fluoroalkyl iodide by a telomerization reaction.

  Fluoroalkyl iodide is used as a raw material for water and oil repellents, fluorine surfactants and the like. The carbon chain length of fluoroalkyl iodide varies depending on the application. For example, the carbon chain length for obtaining water and oil repellency is usually 4 or more.

A fluoroalkyl iodide having a carbon chain length of 4 or more is, for example, a compound of the following formula (1) (hereinafter referred to as compound (1)) (telogen) to a compound of the following formula (2) (hereinafter referred to as compound (2). ) (Taxogen) is added to obtain a compound of the following formula (5) (hereinafter referred to as Compound (5)) (telomer), which is produced by chain length extension by so-called telomerization reaction.
R ^f I (1),
CF ₂ = CF ₂ (2),
R ^f (CF ₂ CF ₂ ) _n I (5).
Here, R ^f is a fluoroalkyl group having 1 or more carbon atoms, and n is the degree of polymerization and is an integer of 1 or more.

Specifically, the following method has been proposed as a method for producing a fluoroalkyl iodide by a telomerization reaction.
(I) adding a compound (2) to the compound (1) in the presence of a radical initiator in the first reactor to obtain a reaction mixture containing the compound (5), and subjecting the mixture to the degree of polymerization; In the second reactor, in the presence of the radical initiator, the compound (2) is added to the compound (5) having a degree of polymerization one less than the desired degree of polymerization in the second reactor. (Patent document 1) which has a process of obtaining the reaction mixture containing the compound (5) of a polymerization degree.

  (Ii) A mixed liquid containing a compound (1), a compound (2) and a radical initiator, which is supplied to a tubular reactor and kept in a liquid phase state under conditions where the mixed liquid does not undergo gas-liquid separation. In which a compound (2) is added to the compound (1) in the presence of a radical initiator to obtain a mixture containing the compound (5) having a desired degree of polymerization (Patent Document 2) ).

In the method (i), the production rate of the compound (5) is higher than that in the method (ii), but the reaction is carried out batchwise, that is, the compound (2) which is a taxogen is a gas phase part in the reactor. Therefore, the compound (5) having a long carbon chain length is likely to be produced.
Moreover, it cannot be said that the production speed is sufficiently high, and further improvement in productivity is desired.

  In the method (ii), the compound (2), which is a taxogen, is reacted under conditions that do not exist more than necessary. Therefore, the selectivity of the compound (5) having a desired degree of polymerization is higher than the method (i). However, productivity is low. Moreover, it cannot be said that the selectivity of the compound (5) is sufficiently high, and further improvement in selectivity is desired.

In the methods (i) and (ii), there is a problem that a compound represented by the following formula (6) (hereinafter referred to as compound (6)) is by-produced. Compound (6) is difficult to separate from compound (5) by distillation.
R ^f (CF ₂ CF ₂ ) _n H (6).
Here, R ^f is a fluoroalkyl group having 1 or more carbon atoms, and n is the degree of polymerization and is an integer of 1 or more.
International Publication No. 02/062735 Pamphlet JP 2006-298817 A

An object of the present invention is to provide a method for producing a fluoroalkyl iodide with high selectivity and high productivity of a fluoroalkyl iodide (telomer) having a desired degree of polymerization.
Another object of the present invention is to provide a method for producing a fluoroalkyl iodide in which the byproduct of a compound in which the iodine atom of the fluoroalkyl iodide is replaced with a hydrogen atom is suppressed.

In the method for producing a fluoroalkyl iodide of the present invention, a compound represented by the following formula (2) is added to a compound represented by the following formula (1) in the presence of the compound represented by the following formula (4). The compound represented by the following formula (3) is obtained.
R ^f I (1),
CF ₂ = CF ₂ (2),
R ^f CF ₂ CF ₂ I (3),
{F (CF ₂ ) _x COO} ₂ (4).
However, R ^f is a fluoroalkyl group having 2 to 16 carbon atoms, and x is an even number of 2 to 14.

The compound represented by the formula (4) is preferably a fluorine-containing radical initiator having a 10-hour half-life temperature of 40 ° C. or less.
The compound represented by the formula (4) is preferably (C ₂ F ₅ COO) ₂ or (C ₄ F ₉ COO) ₂ .

According to the method for producing a fluoroalkyl iodide of the present invention, an intermediate active species (R ^f radical) of the target fluoroalkyl iodide (telomer) produced by the decomposition product (R ^f radical) of the compound represented by formula (4) Therefore, a fluoroalkyl iodide (telomer) having a desired degree of polymerization can be obtained with high selectivity and high productivity. Moreover, since the compound represented by Formula (4) is a perfluoro radical initiator, the by-product of the compound in which the iodine atom of the fluoroalkyl iodide is replaced with a hydrogen atom is suppressed.

It is a block diagram which shows an example of the manufacturing apparatus of a fluoroalkyl iodide.

  In the present specification, a compound represented by the formula (1) is referred to as a compound (1). The same applies to compounds represented by other formulas.

  FIG. 1 is a configuration diagram showing an example of an apparatus for producing a fluoroalkyl iodide. The production apparatus 10 includes a mixing tank 12 for preparing a mixed solution (hereinafter referred to as a first mixed solution) containing the compound (1), the compound (2), and the compound (4), and in the presence of the compound (4). A tubular reactor 14 for adding a compound (2) to a compound (1) to obtain a reaction mixture containing the compound (3) (hereinafter referred to as a second mixture), and a second mixture A first distillation column 16 that separates into compounds (1) and (2) and a mixed liquid excluding the compounds (1) and (2) (hereinafter referred to as a third mixed liquid); A second distillation column 18 that separates the mixture into a compound (3) and a mixture excluding the compound (3) (hereinafter referred to as a fourth mixture), and the compound (1) in the mixing tank 12 The compound (1) supply flow path 20 for supplying the compound (2), the compound (2) supply flow path 22 for supplying the compound (2) to the mixing tank 12, and the compound (4 (4) supply channel 24, first mixed solution supply channel 26 that supplies the first mixed solution in the mixing tank 12 to the tubular reactor 14, and discharge from the tubular reactor 14 The second mixed liquid supply channel 28 for supplying the second mixed liquid to be supplied to the first distillation column 16 and the compounds (1) and (2) taken out from the top of the first distillation column 16 are mixed. A raw material return flow path 30 for returning to the tank 12, a third mixed liquid supply flow path 32 for supplying the third mixed liquid taken out from the bottom of the first distillation tower 16 to the second distillation tower 18, and The compound (3) recovery flow path 34 for recovering the compound (3) taken out from the top of the second distillation column 18 and the fourth mixed liquid taken out from the bottom of the second distillation column 18 are discharged. 4 liquid mixture discharge flow path 36.

The mixing tank 12 is an autoclave equipped with a stirrer.
The tubular reactor 14 is a so-called multi-tube reactor in which a plurality of reaction tubes are arranged in parallel in a shell.
The ratio of the length of the tubular reactor 14 to the maximum inner diameter (length / maximum inner diameter) is preferably 1 or more, and more preferably 3 or more.
The maximum inner diameter of the tubular reactor 14 is usually 0.5 mm to 1.5 m.

In addition, the manufacturing apparatus of a fluoroalkyl iodide is not limited to the thing of the example of illustration.
For example, a line mixer may be used as the mixing tank. The cross-sectional shape of the tubular reactor is not limited to a circular shape, and may be an elliptical shape, a rectangular shape, or the like. The tube reactor may be a single tube type. The tubular reactor may not be installed such that the axial direction of the reaction tube is a vertical direction. The packing may be loaded into a tubular reactor. The material for the filling is preferably a corrosion-resistant material, which may be a metal or a resin. The filling may be an irregular filling or a regular filling.
Moreover, you may use the manufacturing apparatus of patent document 1 as a manufacturing apparatus of a fluoroalkyl iodide.

Next, a method for producing a fluoroalkyl iodide using the production apparatus 10 will be described.
A fluoroalkyl iodide is produced through the following steps (a) to (c).
(A) The process of preparing the liquid mixture containing a compound (1), a compound (2), and a compound (4).
(B) A step of adding the compound (2) to the compound (1) in the presence of the compound (4) in the mixed solution obtained in the step (a) to obtain a mixed solution containing the compound (3). .
(C) The process of collect | recovering the compounds (3) contained in the liquid mixture obtained at the process (b).

Step (a):
A compound (1), a compound (2), and a compound (4) are supplied to the mixing tank 12 from each supply flow path, and it mixes with a stirrer and prepares a 1st liquid mixture.

-20-100 degreeC is preferable and, as for the temperature in the mixing tank 12, -10-80 degreeC is more preferable.
From the point which suppresses the telomerization reaction in the mixing tank 12, the residence time of the 1st liquid mixture in the mixing tank 12 is preferably 30 minutes or less, more preferably 15 minutes or less, and particularly preferably 5 to 15 minutes.

In the compound (1), R ^f is preferably a linear perfluoroalkyl group.
The compound (1) may be selected according to the carbon chain length of the target compound (3). For example, when compound (3) is C ₆ F ₁₃ I, compound (1) is C ₄ F ₉ I, and when compound (3) is C ₄ F ₉ I, compound (1) is C ₂ F ₅ I.
As the compound (1), C ₂ F ₅ I is preferable from the viewpoint of availability. When C ₂ F ₅ I is used as a starting material and finally a compound (3) having a carbon chain length of 6 or more is obtained, the steps (a) to (c) are defined as one cycle, and the compound (3) in the previous cycle May be repeated while using as the compound (1) for the next cycle.

  The molar ratio (compound (1) / compound (2)) between compound (1) and compound (2) in the first mixed solution is preferably 1 or more. Since the compound (2) usually does not dissolve in an equimolar amount or more with respect to the compound (1), if the compound (1) / compound (2) is 1 or more, the compound (1) is converted into the compound (2). ) Will be dissolved at a saturation concentration or less, and the liquid mixture is difficult to separate in the step (b). Therefore, it is difficult to form a gas phase portion in the reaction tube of the tubular reactor 14, and it becomes easy to maintain the liquid phase state of the mixed solution. The compound (1) / compound (2) is more preferably 20 to 200, particularly preferably 70 to 180, from the viewpoint of increasing the selectivity of the compound (3).

Compound (4) is a so-called fluorine-containing radical initiator.
Examples of the compound (4) include (C ₂ F ₅ COO) ₂ , (C ₄ F ₉ COO) ₂ , (C ₆ F ₁₃ COO) ₂ , and (C ₈ F ₁₇ COO) ₂ . The 10 hour half-life temperature of the compound is less than 40 ° C.

  As the compound (4), a fluorine-containing radical initiator having a 10-hour half-life temperature of 40 ° C. or less is preferable. When the 10-hour half-life temperature of the compound (4) is 40 ° C. or less, the compound (3) can be obtained with higher selectivity and higher productivity. Further, the 10-hour half-life temperature of the compound (4) is preferably −20 ° C. or higher.

When the compound (4) having a perfluoroalkyl group having the same or shorter ^Rf carbon chain length as the carbon chain length of the compound (3) is used, the decomposition product of the compound (4) becomes a fluoroalkyl iodide. Since the impurities derived from the radical initiator contained in the compound (3) can be reduced, it is preferable.
For example, when C ₆ F ₁₃ I is to be obtained as the compound (3), it is preferable to use (C ₂ F ₅ COO) ₂ or (C ₄ F ₉ COO) ₂ as the compound (4). Furthermore, when it is desired to obtain C ₆ F ₁₃ I as the compound (3), first, C ₂ F ₅ I is used as the compound (1), and (C ₂ F ₅ COO) ₂ is used as the compound (4). Reaction with 2) gives C ₄ F ₉ I as compound (3). Subsequently, this C ₄ F ₉ I is used for compound (1), and (C ₂ F ₅ COO) ₂ or (C ₄ F ₉ COO) ₂ is used as compound (4) to form compound (2). It is particularly preferable to obtain C ₆ F ₁₃ I as the compound (3) by the reaction.

0.001-2 mol% is preferable with respect to compound (1), and, as for the quantity of a compound (4), 0.01-1 mol% is more preferable.
The compound (4) may be supplied to the mixing tank 12 in a state dissolved in the compound (1), a hydrocarbon organic solvent, a fluorine-containing organic solvent, or the like.

Step (b):
In the tubular reactor 14 of the step (b), the first mixed solution is gradually changed to the second mixed solution, and therefore the first mixed solution and the second mixed solution are clearly defined. I can't distinguish. Therefore, in the present specification, the first mixed solution, the second mixed solution, and the mixed solution of these intermediate states existing in the tubular reactor 14 are collectively referred to simply as “mixed solution”.

Only the first mixed solution is withdrawn from the bottom of the mixing tank 12 without the gas phase portion, and the first mixed solution is supplied to the bottom of the tubular reactor 14 via the first mixed solution supply channel 26.
The first mixed liquid supplied to the bottom of the tubular reactor 14 is distributed to each reaction tube in the tubular reactor 14.
The compound (2) is added to the compound (1) in the presence of the compound (4) while flowing the mixture from the inlet to the outlet of the reaction tube so that the mixture does not undergo gas-liquid separation. A second liquid mixture containing is obtained.
The second mixed liquid is discharged from the head of the tubular reactor 14.

The temperature in the reaction tube is preferably 30 ° C. or more higher than the 10-hour half-life temperature of the compound (4). If it is this temperature, a compound (3) can be obtained with a higher selectivity.
Further, the temperature in the reaction tube is preferably a temperature at which 50 mol% or more of the compound (4) is decomposed within the time during which the mixed solution stays in the tubular reactor 14. If it is this temperature, a compound (3) can be obtained with a still higher selectivity.

The pressure in the reaction tube may be any pressure as long as the liquid mixture can flow in the reaction tube in a liquid phase state without gas-liquid separation.
The residence time of the mixed solution in the tubular reactor 14 is preferably a time sufficient for the compound (2) in the mixed solution to contribute to the reaction and be consumed. Specifically, the residence time is preferably 5 minutes or more, more preferably 10 minutes or more, further preferably 15 minutes or more, and particularly preferably 30 minutes or more. Further, the residence time is preferably 3 hours or less from an industrial viewpoint.

In order to prevent the liquid mixture from being separated into gas and liquid, the molar ratio (compound (1) / compound (2)) between the compound (1) and the compound (2) in the first liquid mixture is set to 1 or more. Etc. are preferably carried out.
In step (b), the compound (2) is added to the compound (1) in the presence of the compound (4) while flowing the mixture from the inlet to the outlet of the reaction tube so that the mixture does not gas-liquid separate. Thus, the compound (3) can be obtained with a higher selectivity for the following three reasons.

(I) When the mixed liquid is gas-liquid separated, a gas phase part (bubbles or the like) is formed. Most of the gas phase part is the compound (2) which cannot be dissolved in the mixed solution. Therefore, when the gas phase part is formed, the compound (2) is unevenly distributed in the liquid phase part (mixed liquid) near the interface with the gas phase part, and the compound ( The telomerization reaction between 3) and the compound (2) proceeds, and the compound (5) in which n is 2 or more is easily generated.
On the other hand, if the mixed solution does not undergo gas-liquid separation, the telomerization reaction between the compound (1) and the compound (2) proceeds preferentially in the mixed solution in which the compound (2) exists uniformly, and the compound ( Since 2) is efficiently consumed, the telomerization reaction between the compound (3) and the excess compound (2) does not proceed easily.
(Ii) When the telomerization reaction between the compound (1) and the compound (2) is performed while flowing the mixed solution from the inlet to the outlet of the reaction tube, the concentration of the compound (2) is relatively low on the inlet side of the reaction tube. Since it is high, compound (2) is efficiently consumed. Therefore, the concentration of the compound (2) gradually decreases as it approaches the outlet side of the reaction tube, and the telomerization reaction between the compound (3) and the compound (2) hardly proceeds on the outlet side of the reaction tube.
(Iii) The state in which the liquid mixture does not undergo gas-liquid separation means that the compound (2) is dissolved in the compound (1) at a saturation concentration or less. In the reasons (i) and (ii), the compound ( As a result of efficient consumption of 2), the second mixture discharged from the tubular reactor 14 contains little or no compound (2). Therefore, since the compound (2) hardly exists on the outlet side of the reaction tube, the telomerization reaction between the compound (3) and the compound (2) hardly proceeds on the outlet side of the reaction tube.

Step (c):
First, the second mixed solution discharged from the tubular reactor 14 is supplied to the first distillation column 16 via the second mixed solution supply flow path 28, The mixed solution is distilled, and the second mixed solution is separated into the compounds (1) and (2) and the third mixed solution. The third mixed solution contains the compound (3) as a main component, and contains a small amount of the compound (5) in which n is 2 or more, other by-products, and the like.
The compounds (1) and (2) taken out from the top of the first distillation column 16 are returned to the mixing tank 12 via the raw material return channel 30 and reused as raw materials.

Next, the third mixed solution taken out from the bottom of the first distillation column 16 is supplied to the second distillation column 18 via the third mixed solution supply flow path 32, and the second distillation column 18 The third mixed solution is distilled to separate the third mixed solution into the compound (3) and the fourth mixed solution.
The compound (3) taken out from the top of the second distillation column 18 is recovered via the compound (3) recovery channel 34.
The fourth mixed liquid taken out from the bottom of the second distillation column 18 is discharged via the fourth mixed liquid discharge channel 36. The fourth liquid mixture contains the compound (5) where n is 2 as a main component, and contains a small amount of the compound (5) where n is 3 or more, other by-products and the like.

In the present invention, it is preferable that the steps (a) to (c) are continuously operated, and it is particularly preferable to perform the steps (a) to (c) in a continuous process.
When the compound (3) is further extended in chain length to finally obtain a compound (3) having a long carbon chain length, the steps (a) to (c) are defined as one cycle, and the compound (3) in the previous cycle is What is necessary is just to repeat this cycle, using it as a compound (1) of the next cycle.

The recovered compound (3) is used as a raw material for the alcohol component of acrylic acid fluoroalkyl ester, for example. The compound (3) is preferably C ₆ F ₁₃ I because it has the following advantages.
(I) A water / oil repellent containing a (co) polymer of a fluoroalkyl ester of acrylic acid can impart water repellency to the substrate while maintaining the texture of the substrate, and also adheres to the substrate at low temperatures (low temperature) Cure property is good.
(Ii) The emulsion stability during polymerization of the fluoroalkyl ester of acrylic acid is good.
(Iii) A fluoroalkyl compound having 6 or less carbon atoms has better environmental adaptability such as biodegradability than a fluoroalkyl compound having 8 or more carbon atoms.

The acrylic acid fluoroalkyl ester can be produced by a known method.
Examples of the resulting fluoroalkyl ester of acrylic acid include the compound (14), and the compound (14-1) is preferable.
_{CH 2 = CZCOO (C 2 H} 4) y CF 2 CF 2 R f ··· (14),
_{CH 2 = CZCOOC 2 H 4 CF} 2 CF 2 R f ··· (14-1).
However, Z _{is, H, CH 3, C 2} H 5, Cl, F or Br, y is an integer of 1 or more.

In the method for producing the fluoroalkyl iodide of the present invention described above, since the compound (4) is used, the compound (3) is highly selected as compared with the case of using a conventional general radical initiator. And high productivity.
That is, since compound (4) has a faster decomposition rate than conventional general radical initiators, the telomerization reaction between compound (1) and compound (2) proceeds efficiently. As a result, productivity is increased. Further, since the telomerization reaction between the compound (1) and the compound (2) proceeds efficiently and the compound (2) is consumed efficiently, the telomerization reaction between the compound (3) and the compound (2) proceeds. And the selectivity of the compound (3) is increased.

Moreover, since the decomposition product (R ^f radical) of the compound (4) becomes an active species similar to the intermediate active species (R ^f radical) of the target fluoroalkyl iodide (telomer), impurities can be reduced, As a result, a fluoroalkyl iodide (telomer) having a desired degree of polymerization can be obtained with high selectivity and high productivity.
Moreover, since the compound (4) is a perfluoro radical initiator, the by-product of the compound (6) in which the iodine atom of the fluoroalkyl iodide is replaced with a hydrogen atom is suppressed.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
Examples 1-2 are examples and examples 3-4 are comparative examples.

The mixed solution discharged from the tubular reactor is subjected to composition analysis by gas chromatography, and C ₆ F ₁₃ I selectivity, C ₆ F ₁₃ I production rate, and C ₄ F ₉ H production rate are obtained as follows. It was.

(C ₆ F ₁₃ I selectivity)
Using the results of the composition analysis, the C ₆ F ₁₃ I selectivity was determined from the following formula.
C ₆ F ₁₃ I selectivity (%) = {1- (C ₈ F ₁₇ I (mol) / C ₆ F ₁₃ I (mol))} × 100.

(C ₆ F ₁₃ I production rate)
As a result of the tubular reactor outlet flow rate value and composition analysis, the C ₆ F ₁₃ I production rate per liter of the tubular reactor was determined from the following equation.
C ₆ F ₁₃ I production rate (g / min) = {C ₆ F ₁₃ I outlet concentration (g / g) × outlet flow rate (g / min)} / reactor capacity.

(C ₄ F ₉ H production rate)
As a result of the tubular reactor outlet flow rate value and composition analysis, the C ₄ F ₉ H production rate was determined from the following equation.
C ₄ F ₉ H production rate (mg / min) = C ₄ F ₉ H outlet concentration (g / g) × outlet flow rate (g / min) × 1000.

[Example 1]
In a mixing tank, an autoclave with a stirrer (stainless steel, volume: 1 L), C ₄ F ₉ I as the compound (1) was supplied at a flow rate of 25 mL / min, and CF ₂ = CF ₂ (tetrafluoro as the compound (2)). (Ethylene) was supplied at a flow rate of 0.37 g / min, and (C ₂ F ₅ COO) ₂ (10-hour half-life temperature: 31 ° C.) as compound (4) was supplied at a flow rate of 0.052 mmol / min. A mixed solution was prepared by mixing. The temperature in the autoclave was 10 ° C., and the residence time of the mixed solution in the autoclave was 10 minutes. The molar ratio (C ₄ F ₉ I / CF ₂ = CF ₂ ) between C ₄ F ₉ I and CF ₂ ═CF ₂ in the mixture is 41, and the amount of (C ₂ F ₅ COO) ₂ is C against ₄ F ₉ I, it was 0.034 mol%.

Only the mixed solution was withdrawn from the bottom of the autoclave without any gas phase portion, and the mixed solution was supplied to the bottom of a tubular reactor (single tube type, volume: 0.5 L).
The mixed solution was allowed to flow from the inlet to the outlet of the reaction tube in the tubular reactor so that the mixed solution did not undergo gas-liquid separation, thereby obtaining a mixed solution containing C ₆ F ₁₃ I as the compound (3). The temperature in the reaction tube was 70 ° C., and the residence time of the mixed solution in the tubular reactor was 20 minutes.
The mixed solution discharged from the tubular reactor was subjected to composition analysis to determine C ₆ F ₁₃ I selectivity, C ₆ F ₁₃ I production rate, and C ₄ F ₉ H production rate. The results are shown in Table 1.

[Example 2]
In a mixing tank, an autoclave with a stirrer (stainless steel, volume: 1 L), C ₄ F ₉ I as the compound (1) was supplied at a flow rate of 25 mL / min, and CF ₂ = CF ₂ (tetrafluoro as the compound (2)). (Ethylene) was supplied at a flow rate of 0.37 g / min, and (C ₂ F ₅ COO) ₂ (10-hour half-life temperature: 31 ° C.) as compound (4) was supplied at a flow rate of 0.155 mmol / min. A mixed solution was prepared by mixing. The temperature in the autoclave was 10 ° C., and the residence time of the mixed solution in the autoclave was 10 minutes. The molar ratio (C ₄ F ₉ I / CF ₂ = CF ₂ ) between C ₄ F ₉ I and CF ₂ ═CF ₂ in the mixture is 41, and the amount of (C ₂ F ₅ COO) ₂ is C It was 0.10 mol% with respect to ₄ F ₉ I.

Only the mixed solution was withdrawn from the bottom of the autoclave without any gas phase portion, and the mixed solution was supplied to the bottom of a tubular reactor (single tube type, volume: 0.5 L).
The mixed solution was allowed to flow from the inlet to the outlet of the reaction tube in the tubular reactor so that the mixed solution did not undergo gas-liquid separation, thereby obtaining a mixed solution containing C ₆ F ₁₃ I as the compound (3). The temperature in the reaction tube was 70 ° C., and the residence time of the mixed solution in the tubular reactor was 20 minutes.
The mixed solution discharged from the tubular reactor was subjected to composition analysis to determine C ₆ F ₁₃ I selectivity, C ₆ F ₁₃ I production rate, and C ₄ F ₉ H production rate. The results are shown in Table 1.

[Example 3]
(C ₂ F ₅ COO) A mixed solution containing C ₆ F ₁₃ I as the compound (3) was obtained in the same manner as in Example 1 except that ₂ was changed to diisopropyl peroxydicarbonate.
The mixed solution discharged from the tubular reactor was subjected to composition analysis to determine C ₆ F ₁₃ I selectivity, C ₆ F ₁₃ I production rate, and C ₄ F ₉ H production rate. The results are shown in Table 1.

[Example 4]
Except that the _(C 2 _F 5 _{COO) 2} was changed to diisopropyl peroxydicarbonate, in the same manner as in Example 2, to obtain a mixture containing _C 6 _{F 13} I is the compound (3).
The mixed solution discharged from the tubular reactor was subjected to composition analysis to determine C ₆ F ₁₃ I selectivity, C ₆ F ₁₃ I production rate, and C ₄ F ₉ H production rate. The results are shown in Table 1.

The fluoroalkyl iodide obtained by the production method of the present invention is useful as a raw material for water and oil repellents, fluorine surfactants and the like.

The entire contents of the specification, claims, drawings and abstract of Japanese Patent Application No. 2007-237661 filed on Sep. 13, 2007 are cited here as disclosure of the specification of the present invention. Incorporated.

Claims (11)

In the presence of the compound represented by the following formula (4), the compound represented by the following formula (2) is added to the compound represented by the following formula (1) to obtain a compound represented by the following formula (3). A process for producing a fluoroalkyl iodide.
R ^f I (1),
CF ₂ = CF ₂ (2),
R ^f CF ₂ CF ₂ I (3),
{F (CF ₂ ) _x COO} ₂ (4).
However, R ^f is a fluoroalkyl group having 2 to 16 carbon atoms, and x is an even number of 2 to 14.   The method for producing a fluoroalkyl iodide according to claim 1, wherein the compound represented by the formula (4) is a fluorine-containing radical initiator having a 10-hour half-life temperature of 40 ° C or lower. Compound represented by the formula (4) _{is (C} 2 F 5 _{COO) 2} or _{(C 4} F 9 _{COO) 2,} the production method of the fluoroalkyl iodide according to claim 1 or 2. The compound represented by the formula (4) is a compound having a perfluoroalkyl group having the same or shorter carbon chain length than the ^Rf carbon chain length of the compound represented by the formula (3). The manufacturing method of the fluoroalkyl iodide of any one of these.   The production of the fluoroalkyl iodide according to any one of claims 1 to 4, wherein 0.001 to 2 mol% of the compound represented by the formula (4) is added to the compound represented by the formula (1). Method.   The method for producing a fluoroalkyl iodide according to any one of claims 1 to 5, wherein a tubular reactor is used as the reactor.   The method for producing a fluoroalkyl iodide according to claim 6, wherein the temperature in the tubular reactor is 30 ° C or more higher than the 10-hour half-life temperature of the compound represented by the formula (4).   The temperature in the tubular reactor is a temperature at which 50 mol% or more of the compound represented by the formula (4) is decomposed within a time during which the reaction solution stays in the tubular reactor. A method for producing a fluoroalkyl iodide.   The molar ratio (compound (1) / compound (2)) of the compound represented by the formula (1) and the compound represented by the formula (2) is 20 to 200. The manufacturing method of the fluoroalkyl iodide of any one. The method for producing a fluoroalkyl iodide according to any one of claims 1 to 9, wherein R ^{f in the} formula (1) is a linear perfluoroalkyl group. The compound represented by the formula (3) _is a C _{6 F 13} I, the production method of the fluoroalkyl iodide according to any one of claims 1 to 10.

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