JP2023021148A - Method for producing perfluoroalkadiene compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method that can give perfluoroalkadiene compounds at high yield while reducing a produced amount of hard-to-separate impurities.

SOLUTION: Provided is a method for producing a perfluoroalkadiene compound represented by the general formula (1): CF₂=CF-(CF₂)_n-4-CF=CF₂ (1) [where n is an integer of 4-20]. The method includes a reaction step where: in an organic solvent, in the presence of a nitrogen-containing compound, an iodine-containing inorganic material, and zinc or a zinc alloy, a reaction is caused to occur with a compound represented by the general formula (2): CF₂X¹-CFX²-(CF₂)_n-4-CFX³-CF₂X⁴ (2) [where n is the same as described above; X¹, X², X³ and X⁴ are the same or different to represent a halogen atom, provided that both of X¹ and X² are not fluorine atoms at the same time, and both of X³ and X⁴ are not fluorine atoms at the same time].

SELECTED DRAWING: None

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present disclosure relates to methods for producing perfluoroalkadiene compounds.

Perfluoroalkadiene compounds are used as dry etching gases for semiconductors, various refrigerants,
It is a compound useful as a blowing agent, a heat transfer medium, etc., and has two double bonds between carbons. In particular, hexafluorobutadiene, which has 4 carbon atoms and double bonds at both ends, is utilized in various applications.

As a method for producing this perfluoroalkadiene compound, ICF ₂ CF ₂ CF ₂ CF ₂ I A method is known in which a compound such as IF is removed (see, for example, Patent Document 1). On the other hand, as _a method for producing perfluoroalkadiene compounds, it is also known to deIF a compound such as _{ICF2CF2CF2CF2I} in the presence _of metallic zinc and a nitrogen- _containing compound (for example, patent Reference 2).

JP-A-62-26240 Japanese Patent Application Laid-Open No. 2001-192345

An object of the present disclosure is to provide a method capable of obtaining a perfluoroalkadiene compound in high yield while reducing the amount of impurities that are difficult to separate.

The present disclosure includes the following configurations.
Section 1. General formula (1):
_CF2 =CF-( _CF2 ) _n-4 -CF= _CF2 (1)
[In the formula, n represents an integer of 4 to 20. ]
A method for producing a perfluoroalkadiene compound represented by
In an organic solvent, in the presence of a nitrogen-containing compound, an iodine-containing inorganic material, and zinc or a zinc alloy,
General formula (2):
_CF2X1 - ^CFX2- ( _CF2 ) _n-4 ^{- CFX3 -} _CF2X4 (2)
[In the formula, n is the same as above. X ¹ , X ² , X ³ and X ⁴ are the same or different and represent a halogen atom. However, both ^X1 and ^X2 are not fluorine atoms, and both ^X3 and ^X4 are not fluorine atoms. ]
A production method comprising a reaction step of reacting a compound represented by
Section 2. The amount of the iodine-containing inorganic material used is 0.000 per 1 mol of the zinc or zinc alloy
Item 2. The production method according to Item 1, wherein the amount is 5 mol or more and the solubility of the organic solvent is not more than that.
Item 3. Item 3. The production method according to Item 1 or 2, wherein the iodine-containing inorganic material is iodine and/or a metal iodide.
Section 4. Any one of Items 1 to 3, wherein the reaction step includes a first mixing step of mixing a solution containing the iodine-containing inorganic material, the zinc or zinc alloy, and the organic solvent, and the nitrogen-containing compound. The manufacturing method described in .
Item 5. Item 4, wherein in the first mixing step, the nitrogen-containing compound is added to the solution containing the zinc or zinc alloy at an addition rate of 0.1 to 600 mol/hour with respect to 1 mol of the zinc or zinc alloy. Method of manufacture as described.
Item 6. Item 6. The production method according to item 4 or 5, wherein the reaction step includes a second mixing step of mixing the obtained mixture with the compound represented by the general formula (2) after the first mixing step.
Item 7. In the second mixing step, 0.05 to 30 mol/hour of the compound represented by the general formula (2) is added to 1 mol of the zinc or zinc alloy in the mixture obtained in the first mixing step. Item 6. The method according to Item 6, wherein the addition rate is
Item 8. Items 4 to 7, wherein the first mixing step is performed at a temperature of 50 to 200°C when mixing the nitrogen-containing compound with the solution containing the iodine-containing inorganic material, zinc or zinc alloy, and the organic solvent.
The production method according to any one of.
Item 9. Item 9. The production method according to any one of Items 1 to 8, wherein the nitrogen-containing compound is N,N-dimethylformamide.
Item 10. Item 10. The production method according to any one of Items 1 to 9, wherein the boiling point of the organic solvent is equal to or lower than the boiling point of the nitrogen-containing compound.
Item 11. General formula (1):
_CF2 =CF-( _CF2 ) _n-4 -CF= _CF2 (1)
[In the formula, n represents an integer of 4 to 20. ]
A perfluoroalkadiene compound represented by
General formula (3):
_CF2 =CF-( _CF2 ) _n-4 - ^CFX3 - _CF2H (3)
[In the formula, n is the same as above. ^X3 represents a halogen atom. ]
A compound represented by
General formula (4A):
_CF2X1 ^{- CFX2-} ( _CF2 ) _n-4 -CF= _CF2 (4A)
[In the formula, n is the same as above. X ¹ and X ² are the same or different and represent a halogen atom. However, both X ¹ and X ² are not fluorine atoms. ]
A compound represented by and / or general formula (4B):
_CF2H - ^CFX2- ( _CF2 ) _n-4 - ^CFX3 - _CF2H (4B)
[In the formula, n is the same as above. ^X2 and ^X3 are the same or different and represent a halogen atom. ]
A compound represented by
General formula (5):
_CF2X1 - ^CFX2- ( _CF2 ) _n-4 - ^{CFX3 -} _CF2H (5)
[In the formula, n is the same as above. X ¹ , X ² and X ³ are the same or different and represent a halogen atom. However, both X ¹ and X ² are not fluorine atoms. ]
A perfluoroalkadiene composition containing a compound represented by
Item 12. The general formula (1
Item 12. The perfluoroalkadiene composition according to item 11, wherein the content of the compound represented by ) is 80 to 99.8 mol%.
Item 13. 13. The perfluoroalkadiene composition according to Item 11 or 12, wherein the perfluoroalkadiene compound is hexafluorobutadiene.
Item 14. An etching gas, refrigerant, heat transfer medium, foaming agent or resin monomer comprising the perfluoroalkadiene composition according to any one of Items 11 to 13.

According to the present disclosure, a perfluoroalkadiene compound can be obtained in high yield while reducing the amount of impurities that are difficult to separate.

As used herein, "containing" means "comprise", "consisting essentially of
It is a concept that includes both "consist of" and "consist of". Further, in this specification, when a numerical range is indicated by "A to B", it means A or more and B or less.

The method for producing the perfluoroalkadiene compound of the present disclosure comprises general formula (1):
_CF2 =CF-( _CF2 ) _n-4 -CF= _CF2 (1)
[In the formula, n represents an integer of 4 to 20. ]
A method for producing a perfluoroalkadiene compound represented by
In an organic solvent, in the presence of a nitrogen-containing compound, an iodine-containing inorganic material, and zinc or a zinc alloy,
General formula (2):
_CF2X1 - ^CFX2- ( _CF2 ) _n-4 ^{- CFX3 -} _CF2X4 (2)
[In the formula, n is the same as above. X ¹ , X ² , X ³ and X ⁴ are the same or different and represent a halogen atom. However, both ^X1 and ^X2 are not fluorine atoms, and both ^X3 and ^X4 are not fluorine atoms. ]
A reaction step of reacting is provided.

In the present disclosure, the yield is higher than the methods of Patent Documents 1 and 2, and the separation of 1,1,1,2,4,4,4-heptafluoro-2-butene and the like is better than that of Patent Document 2. The desired product can be obtained by suppressing impurities that are difficult to remove.

In general formulas (1) and (2), n is an integer of 4-20, more preferably an integer of 4-10. Within this range, the perfluoroalkadiene compound can be obtained at a higher yield while reducing the amount of impurities that are difficult to separate.

That is, the perfluoroalkadiene compound represented by the general formula (1) to be produced is hexafluorobutadiene ( _CF2 =CF-CF= _CF2 ), octafluoropentadiene ( _CF2 =CF-
_CF2 -CF= _CF2 ), decafluorohexadiene ( _CF2 =CF- _CF2 - _CF2 -CF= _CF2 ), and the like.

In general formula (2), X ¹ , X ² , X ³ and X ⁴ are halogen atoms such as fluorine, chlorine, bromine and iodine atoms. X ¹ , X ² , X ³ and X ⁴ may be the same or different. However, when both X ¹ and X ² are fluorine atoms, or when both X ³ and X ⁴ are fluorine atoms, the reaction does not proceed and a perfluoroalkadiene compound cannot be obtained ^.
and ^X2 are not both fluorine atoms, and both ^X3 and ^X4 are not fluorine atoms. Among them, X ¹ is a chlorine atom, a bromine atom, an iodine atom, etc. (especially a chlorine atom , bromine atom, etc.) are preferred, and X ² is a fluorine atom,
A chlorine atom, a bromine atom, etc. (especially a fluorine atom, a chlorine atom, etc.) are preferred, ^X3 is preferably a fluorine atom, a chlorine atom, etc. (especially a fluorine atom), and ^X4 is a chlorine atom, a bromine atom, an iodine atom, etc. ( Bromine atom, iodine atom, etc.) are particularly preferred.

Examples of the compound represented by the general formula (2) that satisfies these conditions include ClCF ₂ -CFCl-.
CF2 _{- CF2I} , _ClCF2- CFCl _- CF2- _CF2 -CF2I, ClCF2 _- CFCl- _CF2 - _CF2 - _{CF2 -CF2I} , ICF2 _{- CF2 -CF2 -} CF ₂
I, _ICF2 - _CF2 -CF2- _CF2 - _CF2I , ICF2 _- CF2- _CF2 - _{CF2 - CF2 -CF2I} , _{BrCF2 - CF2} - _{CF2 -CF2Br} , _BrCF2-
CF ₂ -CF ₂ -CF ₂ -CF ₂ -Br, BrCF ₂ -CF ₂ -CF ₂ -CF ₂ -CF ₂ -CF 2 -CF ₂ Br, etc., and perfluorinated perfluorinated compounds while reducing the amount of impurities that are difficult to separate. ClCF ₂ -CFCl-CF ₂ -CF _{2 I} , ClCF _{2 -CFCl} -CF 2 -CF 2 -CF ₂ I, ClCF ₂ -CFCl-CF ₂ from the viewpoint of obtaining an alkadiene compound in a higher yield _-CF2 -C
_F2 - _CF2I , _BrCF2 - _CF2 -CF2 _- CF2Br, BrCF2 _{-CF2 - CF2} - _CF2 - _CF2Br , BrCF2 _{- CF2} - _CF2 - _{CF2 - CF2 -CF2}
Br and the like are preferred, and _BrCF2 - _CF2 - _CF2 - _CF2Br , BrCF2 _-CF2 - _CF2 - _{CF2 -CF2Br} , BrCF2 _{- CF2 - CF2} - _CF2-
CF ₂ -CF ₂ Br and the like are more preferable.

The amount of the compound represented by the general formula (2) is determined from the viewpoint of obtaining a perfluoroalkadiene compound at a higher yield while reducing the amount of impurities that are difficult to separate. It is preferably 0.05 to 30 mol, more preferably 0.1 to 10 mol, even more preferably 0.2 to 5 mol, per 1 mol.

The nitrogen-containing compound is not particularly limited as long as it is a compound containing a nitrogen atom.
Amide compounds (N,N-dimethylformamide, N,N-diisopropylformamide, etc.), amine compounds (triethylamine, etc.), pyridine compounds (pyridine, methylpyridine, N-methyl-2-pyrrolidone, etc.), quinoline compounds (quinoline, methyl quinoline, etc.). These nitrogen-containing compounds can be used alone or in combination of two or more. Among them, amide compounds are preferred, and N,N-dimethylformamide is more preferred, from the viewpoint of obtaining a perfluoroalkadiene compound in a higher yield while reducing the amount of impurities that are difficult to separate.

This nitrogen-containing compound includes compounds that are liquid at room temperature. It is preferable to use (use a small amount) as. The amount of nitrogen-containing compound used is preferably 0.25 to 4 mol, and 0.5 to 1 mol of zinc or zinc alloy described later.
~2 molar is more preferred.

The iodine-containing inorganic material is not particularly limited as long as it contains an iodine atom.
Examples thereof include iodine; metal iodides such as typical metal iodides (sodium iodide, potassium iodide, magnesium iodide, calcium iodide, etc.), transition metal iodides (zinc iodide, etc.), and the like. According to the manufacturing method of the present disclosure, zinc halide (a mixture of zinc fluoride, zinc chloride and zinc iodide) may be produced as an impurity in the product. Zinc halide as an impurity contained in this product can be used as an iodine-containing inorganic material and reused in the production method of the present disclosure. These iodine-containing inorganic materials can be used alone or in combination of two or more. Among them, from the viewpoint of obtaining a perfluoroalkadiene compound at a higher yield while reducing the amount of impurities that are difficult to separate, iodine, transition metal iodides, and impurities in the product produced by the production method of the present disclosure is preferred, and iodine is more preferred. It should be noted that when a halogen-containing material such as zinc fluoride or zinc chloride is used instead of the iodine-containing inorganic compound, the effect of improving the yield of the perfluoroalkadiene compound is reduced. I can't get it.

The amount of the iodine-containing inorganic compound used is 0.0005 mol or more per 1 mol of zinc or zinc alloy from the viewpoint of obtaining a perfluoroalkadiene compound at a higher yield while reducing the amount of impurities that are difficult to separate. and preferably not more than the solubility of the organic solvent, more preferably 0.001 to 0.1 mol per 1 mol of zinc or zinc alloy.

Elements that can be contained in zinc or zinc alloys when using zinc alloys include:
Examples include lead, cadmium, and iron. Commercially available zinc contains lead, cadmium,
It may also contain impurities such as iron. The present disclosure also includes those containing these impurities.

As the organic solvent, a non-polar organic solvent is preferable from the viewpoint of dissolving the compound represented by the general formula (1), the iodine-containing inorganic material, and the like. The organic solvent preferably has a boiling point lower than that of the nitrogen-containing compound. Examples of such organic solvents include heptane, hexane,
Aromatic hydrocarbon compounds such as benzene, toluene and xylene; and ether compounds such as tetrahydrofuran and diethyl ether.

The amount of the organic solvent to be used is not particularly limited as long as it is a solvent amount, and is preferably 0.01 to 10 mol, more preferably 0.1 to 5 mol, per 1 mol of zinc or zinc alloy.

In the production method of the present disclosure, the compound represented by general formula (2) is reacted in an organic solvent in the presence of a nitrogen-containing compound, an iodine-containing inorganic material, and zinc or a zinc alloy. The order of addition is not particularly limited, and they can be added simultaneously or sequentially.
Among them, from the viewpoint of obtaining a perfluoroalkadiene compound at a higher yield while reducing the amount of impurities that are difficult to separate, a solution containing an iodine-containing inorganic material, the zinc or zinc alloy, and an organic solvent; It is preferable to mix a nitrogen-containing compound (in particular, to add the nitrogen-containing compound to a solution containing the iodine-containing inorganic material, the zinc or zinc alloy, and an organic solvent).

In the solution containing the iodine-containing inorganic material, the zinc or zinc alloy, and the organic solvent, the content of each component is preferably adjusted so as to satisfy the content ratio of each component described above. note that,
When mixing (especially adding) the compound represented by the general formula (2) in a later process, consider the amount of the compound represented by the general formula (2) to be mixed (especially added) It is preferable to adjust the content of the component.

A solution containing an iodine-containing inorganic material, the zinc or zinc alloy, and an organic solvent is mixed with a nitrogen-containing compound. is added), it is preferable to mix the solution containing the iodine-containing inorganic material, the zinc or zinc alloy, and the organic solvent with the nitrogen-containing compound at a temperature of preferably 50 to 200°C, more preferably 100 to 150°C. In particular, it is preferable to add a nitrogen-containing compound to a solution containing an iodine-containing inorganic material, the zinc or zinc alloy, and an organic solvent at a temperature of preferably 50 to 200°C, more preferably 100 to 150°C. Further, by adding a nitrogen-containing compound while refluxing a solution containing an iodine-containing inorganic material, zinc or a zinc alloy, and an organic solvent, the solvent is lower than the reaction temperature and volatilizes at the reaction temperature. It can also be returned to the reactor. When adding a nitrogen-containing compound while refluxing a solution containing an iodine-containing inorganic material, zinc or a zinc alloy, and an organic solvent, it is most preferable to heat the solution to a reflux temperature.

After heating (in particular, heating to reflux temperature), the solution containing the iodine-containing inorganic material, the zinc or zinc alloy, and the organic solvent is mixed with the nitrogen-containing compound. For example, when adding a nitrogen-containing compound to a solution containing an iodine-containing inorganic material, the zinc or zinc alloy, and an organic solvent, the addition rate (dripping rate) is adjusted to reduce the amount of impurities that are difficult to separate. From the viewpoint of obtaining a higher yield of the perfluoroalkadiene compound represented by the general formula (1), 0.1 to 600 mol/hour is preferable, and 0.33 to 60 mol/hour is more preferable with respect to 1 mol of the zinc or zinc alloy. . The addition time is preferably such that the reaction proceeds sufficiently, and it is particularly preferable to adjust the total amount of the added nitrogen-containing compound within the above range. Specifically, the addition time is preferably 0.002 to 10 hours, more preferably 0.02 to 3 hours.

In the production method of the present disclosure described above, a solution containing an iodine-containing inorganic material, the zinc or zinc alloy, and an organic solvent is mixed with a nitrogen-containing compound (especially, an iodine-containing inorganic material, the zinc or zinc alloy, and an organic solvent When a nitrogen-containing compound is added to a solution containing and), the compound represented by the general formula (2), which is a substrate, is added to a solution containing an iodine-containing inorganic material, the zinc or zinc alloy, and an organic solvent. may be contained (hereinafter sometimes referred to as "substrate pre-addition"), and a solution containing an iodine-containing inorganic material, the zinc or zinc alloy, and an organic solvent is mixed with a nitrogen-containing compound (particularly, After adding a nitrogen-containing compound to a solution containing an iodine-containing inorganic material, the zinc or zinc alloy, and an organic solvent), the thus obtained solution and the compound represented by the general formula (2), which is a substrate, Mixing (particularly, adding the compound represented by the general formula (2) as a substrate to the solution thus obtained) may be performed (hereinafter sometimes referred to as "addition after substrate"). Among these, by reacting zinc or a zinc alloy with a nitrogen-containing compound in advance, the compound represented by the general formula (2) reacts with the nitrogen-containing compound to generate impurities that are difficult to separate. From the viewpoint of further suppressing , and consequently improving the yield of the perfluoroalkadiene compound, addition after the substrate is particularly preferred.

When the substrate pre-addition is adopted, the content of the compound represented by the general formula (2) contained in the solution containing the iodine-containing inorganic material, the zinc or zinc alloy, and the organic solvent is equal to the content of each component described above. It is preferable to adjust to meet the ratio.

When the post-addition of the substrate is employed, after adding the nitrogen-containing compound to the solution containing the iodine-containing inorganic material, the zinc or zinc alloy, and the organic solvent, the solution obtained in this way is added with the substrate of the general formula (2 ), the addition rate (dripping rate) of the compound represented by the general formula (2) when adding the compound represented by the general formula (1) while reducing the amount of impurities that are difficult to separate. 0.05 to 30 mol/hour, more preferably 0.17 to 6 mol/hour, with respect to 1 mol of the zinc or zinc alloy, from the viewpoint of obtaining a perfluoroalkadiene compound with a higher yield. The addition time is preferably such that the reaction proceeds sufficiently, especially the general formula (2)
It is preferable to adjust so that the total amount of the added compound represented by is within the above range.
Specifically, the addition time is preferably 0.02 to 10 hours, more preferably 0.08 to 3 hours.

In addition, the reaction conditions other than the above are not particularly limited. For example, the reaction atmosphere is preferably an inert gas atmosphere (nitrogen gas atmosphere, argon gas atmosphere, etc.), and the reaction time (maintenance time at the maximum temperature reached) is sufficient to allow the reaction to proceed. It can be the extent to which it progresses. After completion of the reaction, the perfluoroalkadiene compound represented by the general formula (1) can be obtained by performing a purification treatment according to a conventional method.

According to the production method of the present disclosure, the yield of the perfluoroalkadiene compound represented by the general formula (1) is increased while the amount of impurities that are difficult to separate is reduced. The perfluoroalkadiene compound represented by the general formula (1) can be efficiently obtained while reducing labor for isolating difficult impurities. Impurities that are difficult to separate are, for example, 1,1,1,2,4,4,4-hepta Fluoro-2-butene ( _CF3CF = _CHCF3 )
etc.

The perfluoroalkadiene compound represented by the general formula (1) thus obtained is
It can be effectively used for various purposes such as etching gas for forming state-of-the-art fine structures such as semiconductors and liquid crystals, as well as refrigerants, heat transfer media, foaming agents, and resin monomers.

In this way, the perfluoroalkadiene compound represented by general formula (1) can be obtained, and the perfluoroalkadiene compound represented by general formula (1) and general formula (3):
_CF2 =CF-( _CF2 ) _n-4 - ^CFX3 - _CF2H (3)
[In the formula, n is the same as above. ^X3 represents a halogen atom. ]
and a compound represented by general formula (4A):
_CF2X1 ^{- CFX2-} ( _CF2 ) _n-4 -CF= _CF2 (4A)
[In the formula, n is the same as above. X ¹ and X ² are the same or different and represent a halogen atom. However, both X ¹ and X ² are not fluorine atoms. ]
A compound represented by and / or general formula (4B):
_CF2H - ^CFX2- ( _CF2 ) _n-4 - ^CFX3 - _CF2H (4B)
[In the formula, n is the same as above. ^X2 and ^X3 are the same or different and represent a halogen atom. ]
and a compound represented by general formula (5):
_CF2X1 - ^CFX2- ( _CF2 ) _n-4 - ^{CFX3 -} _CF2H (5)
[In the formula, n is the same as above. X ¹ , X ² and X ³ are the same or different and represent a halogen atom. However, both X ¹ and X ² are not fluorine atoms. ]
It may be obtained in the form of a perfluoroalkadiene composition containing the compound represented by.

In the general formula (3), ^X3 is a halogen atom, a fluorine atom, a chlorine atom, a bromine atom,
An iodine atom etc. are mentioned. As with the general formula (2), X ³ is preferably a fluorine atom, a chlorine atom, or the like (especially a fluorine atom). Compounds represented by the general formula (3) satisfying such conditions include, for example, _CF2 =CF- _CF2 - _CF2H , _CF2 =CF- _CF2 - _CF2 - _CF2H , and _CF2. =CF- _CF2 - _CF2 - _CF2 - _CF2H
etc.

In general formula (4A), X ¹ and X ² are halogen atoms such as fluorine, chlorine, bromine and iodine atoms. ^X1 and ^X2 may be the same or different. However, both X ¹ and X ² are not fluorine atoms as in the general formula (2). As in the general formula (2), X ¹ is preferably a chlorine atom, a bromine atom, an iodine atom (especially a chlorine atom, a bromine atom, etc.), and X ² is a fluorine atom, a chlorine atom, a bromine atom, etc. (especially a fluorine atom). atoms, chlorine atoms, etc.) are preferred. Examples of the compound represented by the general formula (4A) include ClCF ₂ -CFCl-CF=
_CF2 , _ClCF2 -CFCl-CF2- _CF = _CF2 , ClCF2 _- CFCl-CF2- _CF2 - _CF = _CF2 , ICF2 _- CF2- _CF = _CF2 , ICF2 _{- CF2
-CF2} -CF= _CF2 , ICF2 _{-CF2 -CF2 -CF2} -CF=CF2 _{, BrCF2 -CF2 -CF} = _CF2 , _{BrCF2 -CF2 -CF2 -CF} = _CF2 , Br
CF ₂ -CF ₂ -CF ₂ -CF ₂ -CF=CF ₂ and the like, and ClCF ₂ -CFCl-CF=CF ₂ for the same reason as general formula (2).
, _ClCF2 -CFCl- _CF2 -CF= _CF2 , ClCF2 _- CFCl-CF2- _CF2 - _CF = _CF2 , BrCF2 _- CF2- _CF = _CF2 , BrCF2 _{- CF2-
CF2} -CF= _CF2 , _BrCF2 - _CF2 -CF2- _CF2 -CF= _CF2 and the like are preferred, and _BrCF2 - _CF2 - _CF = _CF2 , BrCF2 _{- CF2} -CF
₂ -CF= _CF2 , _BrCF2 - _CF2 - _CF2 - _CF2 -CF= _CF2 and the like are more preferred.

In general formula (4B), ^X2 and ^X3 are halogen atoms such as fluorine, chlorine, bromine and iodine atoms. ^X2 and ^X3 may be the same or different. general formula (2
), ^X2 is preferably a fluorine atom, a chlorine atom, a bromine atom or the like (especially a fluorine atom, a chlorine atom or the like), and ^X3 is preferably a fluorine atom, a chlorine atom or the like (especially a fluorine atom). Examples of the compound represented by the general formula (4B) that satisfies such conditions include HCF ₂ -CFCl-CF ₂ -.
_CF2H , _HCF2 -CFCl-CF2- _CF2 -CF2H, _{HCF2 -} CFCl-CF2- _{CF2 - CF2 - CF2H} , HCF2 _{- CF2- CF2} - _CF2H , HCF
₂ - _CF2 - _CF2 - _CF2 - _CF2H , HCF2 _{- CF2} - _CF2 - _CF2 - _CF2 - _CF2H , etc., and HCF ₂ - _CF2 - _CF2 - _CF2H , HCF2 _- CF2- _CF2 - _{CF2 -CF2H} , HCF2 _{- CF2} - _CF2 - _{CF2 - CF2} - _CF2H and the like are preferred.

In general formula (5), X ¹ , X ² and X ³ are halogen atoms, fluorine atom, chlorine atom,
A bromine atom, an iodine atom and the like can be mentioned. X ¹ , X ² and X ³ may be the same or different. However, both X ¹ and X ² are not fluorine atoms as in the general formula (2). general formula (2
), X ¹ is preferably a chlorine atom, a bromine atom, an iodine atom (especially a chlorine atom, a bromine atom, etc.), and X ² is a fluorine atom, a chlorine atom, a bromine atom, etc. (especially a fluorine atom, a chlorine atom etc.), and X ³ is preferably a fluorine atom, a chlorine atom or the like (especially a fluorine atom).
Especially when ^X3 is a fluorine atom, the compound represented by general formula (5) occurs mostly in the liquid phase and hardly exists in the gas phase, so only the gas phase of the collection cylinder is analyzed. is not detected. That is, the perfluoroalkadiene composition of the present disclosure is composed of impurities present in both the gas phase and liquid phase of the collection cylinder. Examples of compounds represented by general formula (5) that satisfy these conditions include _ClCF2- CFCl- _CF2 - _CF2H and _ClCF2- CFCl- _CF2 - _CF2 -C.
_F2H , _ClCF2 -CFCl-CF2- _CF2 - _CF2 -CF2H, ICF2 _{- CF2} - _CF2 - _CF2H , ICF2 _{- CF2 - CF2 -CF2 - CF2H} , _ICF2
-CF2- CF2- _{CF2 - CF2} - _CF2H , BrCF2- _CF2 - _CF2-CF2H , _BrCF2 - _{CF2 - CF2} - _{CF2 -} CF2H, _{BrCF2 -} CF ₂ - _CF2
-CF2 - _CF2 - _CF2H and the like, and _ClCF2 -CFCl- _CF2 - _CF2H , _ClCF2 for the same reason as in general formula (2).
-CFCl- _{CF2- CF2 - CF2H} , ClCF2 _- CFCl-CF2- _CF2 - _{CF2-CF2H ,} BrCF2 _- CF2 _-CF2 - _CF2H , _{BrCF2 - CF2-} C.
_F2 - _CF2 - _CF2H , _BrCF2 - _CF2 -CF2- _CF2 - _{CF2 -CF2H ,} etc. are preferred, and _BrCF2 - _CF2 - _{CF2- CF2H} , BrCF2 _- C
_F2 - _CF2 - _CF2 - _CF2H , _BrCF2 - _CF2 - _CF2 - _CF2 - _CF2 - _CF2H and the like are more preferable.

In the perfluoroalkadiene composition of the present disclosure, the content of the perfluoroalkadiene compound represented by the general formula (1) is 80 to 99.8 when the total amount of the perfluoroalkadiene composition of the present disclosure is 100 mol%. mol% (especially 85 to 99 mol%) is preferable, and the content of the compound represented by general formula (3) is preferably 0.1 to 12 mol% (especially 0.5 to 10 mol%), and general formula (4A) and / Or the total content of the compound represented by (4B) is preferably 0.01 to 0.6 mol% (especially 0.02 to 0.5 mol%), and the content of the compound represented by general formula (5) is 0.05 to 1 mol% ( 0.1 to 0.5 mol %) is particularly preferred. In addition, in the perfluoroalkadiene composition of the present disclosure, components other than the above (
The content of other components) is preferably 0 to 5 mol % (especially 0.01 to 4 mol %). In the case of obtaining hexafluorobutadiene as a perfluoroalkadiene compound represented by general formula (1), 1,1,1,2,4,4,4- Heptafluoro-2-
Butene (CF ₃ CF=CHCF ₃ ), etc.) may be included, so it is preferable to reduce the content of other components as much as possible.

Such a perfluoroalkadiene composition of the present disclosure, like the above-described perfluoroalkadiene compound alone, can be used as an etching gas for forming state-of-the-art microstructures such as semiconductors and liquid crystals, as well as coolants. , heat transfer medium, foaming agent, resin monomer, etc.

Examples are provided below to clarify features of the present disclosure. The disclosure is not limited to these examples.

Example 1: ClCF2 _- CFCl-CF2 _- CF2I _; ZnI2 _0.18 mol%
200 g (0.53 mol
) of xylene, 34.93 g (0.53 mol) of zinc, 0.30 g (0.001 mol; 0.18 mol% relative to zinc) of
ZnI ₂ was added and heated with stirring until the internal temperature reached 140°C. After the internal temperature became constant, N,N-dimethylformamide (DMF) was added dropwise at a rate of 0.52 mol/hour (1.0 to 1 mol of zinc) while refluxing.
04 mol/hour) was added dropwise for 1 hour, and the mixture was heated under reflux with stirring for 0.5 hour. Then, while refluxing, the raw material ( _ClCF2 -CFCl- _CF2 - _CF2I ) was dropped at a rate of 0.24 mol/hour (0.48 mol/hour per 1 mol of zinc).
The mixture was added dropwise for 1 hour, and the reaction was allowed to continue with heating under reflux for 3 hours while stirring. After the reaction was completed, the gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography, and the conversion rate and selectivity were calculated in consideration of each. is the selectivity of CF
₂ =CFCF= _CF2 88 mol%, _CF2 =CF- _CF2 - _CF2H 8.2 mol%, ClCF2 _- CFCl-CF= _CF2 0.051 mol%, C
_lCF2 -CFCl- _CF2 - _CF2H was 0.32 mol%, and other by-products ( _CF3CF = _CHCF3 etc.) were 3.4 mol% in total.

Example 2: ClCF2 _- CFCl-CF2 _- CF2I _; ZnI2 _0.6 mol%
The treatment was carried out in the same manner as in Example 1, except that the amount of ZnI ₂ used was 0.95 g (0.003 mol; 0.56 mol % with respect to zinc). After the reaction was completed, the gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography, and the conversion rate and selectivity were calculated in consideration of each.
The selectivity of each component is 91 mol% for _CF2 =CFCF= _CF2 , 6.8 mol% for _CF2 =CF- _CF2 - _CF2H , and _ClCF2- CFCl-CF= _CF2. was 0.042 mol %, ClCF ₂ --CFCl--CF ₂ --CF ₂ H was 0.18 mol %, and other by-products (CF ₃ CF=CHCF ₃ etc.) were 2.0 mol % in total.

Example 3: ClCF2 _- CFCl-CF2 _- CF2I _; ZnI2 _1.6 mol%
The treatment was carried out in the same manner as in Example 1, except that the amount of ZnI ₂ used was 2.70 g (0.53 mol; 1.6 mol % relative to zinc). After the reaction was completed, the gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography.
The selectivity of each component is 93 mol% for _CF2 =CFCF= _CF2 and 5.6 mol% for _CF2 =CF- _CF2 - _CF2H .
, 0.082 mol% of ClCF2 _- CFCl-CF= _CF2 , 0.27 mol% of _ClCF2 -CFCl- _CF2 - _CF2H , and a total of 1.0 mol% of other by-products ( _CF3CF = _CHCF3, etc.) there were.

Example 4: ClCF2 _- CFCl-CF2 _- CF2I _; 1.6 mol% _I2
Same as Example ₁ except 2.20 g (0.009 mol; 1.6 mol% relative to zinc) _I2 was used instead of 0.30 g (0.001 mol; 0.18 mol% relative to zinc) ZnI2 did After completion of the reaction,
The gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography, and the conversion rate and selectivity were calculated in consideration of each. , _CF2 =CFCF= _CF2 96 mol%, _CF2 =CF- _CF2 - _CF2H 2.6 mol%, ClCF2 _- CFCl-CF= _CF2 0.031 mol
%, 0.17 mol% of _ClCF2 -CFCl- _CF2 - _CF2H , and a total of 1.2 mol% of other by-products ( _CF3CF = _CHCF3 , etc.)
Met.

Example 5: ClCF2 _- CFCl-CF2 _- CF2I _; NaI 1.6 mol%
The treatment was as in Example ₁ , except that 1.27 g (0.0085 mol; 1.6 mol% relative to zinc) NaI was used instead of 0.30 g (0.001 mol; 0.18 mol% relative to zinc) ZnI2. gone. After the reaction was completed, the gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography, and the conversion rate and selectivity were calculated in consideration of each. The selectivity of _CF2 =CFCF= _CF2 is 91 mol%, _CF2 =CF- _CF2 - _CF2H is 6.1 mol%, and _ClCF2- CFCl-CF= _CF2 is 0.053
mol %, ClCF ₂ -CFCl-CF ₂ -CF ₂ H 0.32 mol %, other by-products (CF ₃ CF=CHCF ₃ etc.) total 2.5
was mol %.

Example 6: ClCF2 _- CFCl-CF2 _- CF2I _; NaI 3.2 mol%
The treatment was as in Example ₁ , except that 2.54 g (0.017 mol; 3.2 mol% relative to zinc) NaI was used instead of 0.30 g (0.001 mol; 0.18 mol% relative to zinc) ZnI2. gone. After the reaction was completed, the gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography, and the conversion rate and selectivity were calculated in consideration of each. The selectivity of _CF2 =CFCF= _CF2 is 94 mol%, _CF2 =CF- _CF2 - _CF2H is 5.1 mol%, _ClCF2- CFCl-CF= _CF2 is 0.044 mol%, _ClCF2- CFCl--CF ₂ --CF ₂ H was 0.12 mol %, and other by-products (CF ₃ CF=CHCF ₃ etc.) were 0.72 mol % in total.

Reference Example 1: ClCF2 _- CFCl-CF2 _- CF2I _; no iodine-containing inorganic material
The treatment was carried out as in Example 1, except that ZnI ₂ was not used. After the reaction was completed, the gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography, and the conversion rate and selectivity were calculated in consideration of each. The selectivity of CF ₂ =
CFCF= _CF2 78 mol%, _CF2 =CF- _CF2 - _CF2H 14 mol%, _ClCF2- CFCl-CF= _CF2 0.66 mol%, _ClCF2
-CFCl- _CF2 - _CF2H was 1.5 mol%, and other by-products ( _CF3CF = _CHCF3 etc.) were 5.9 mol% in total.

Example 7: ICF2 _- CF2-CF2 _- CF2I _; ZnI2 _1.6 mol%
Using _ICF2 -CF2- _CF2 - _CF2I instead of _ClCF2 -CFCl- _CF2 - _CF2I as the substrate and reducing the amount of _ZnI2 used
The treatment was carried out in the same manner as in Example 1, except that 2.70 g (0.53 mol; 1.6 mol% with respect to zinc) was used. After the reaction was completed, the gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography, and the conversion rate and selectivity were calculated in consideration of each. The selectivity of _CF2 =CFCF= _CF2 is 87 mol%, _CF2 =CF- _CF2 - _CF2H is 5.4 mol%, and _HCF2 - _CF2 -CF2 _- C
_F2H was 2.2 mol%, ICF2 _{- CF2} -CF2 _{-CF2H was} 2.1 mol%, and other by-products ( _CF3CF = _CHCF3 , etc.) were a total of 3.3 mol%.

_{Reference Example} 2: ICF2 _{- CF2} - _{CF2 -} CF2I _; no iodine-containing _{inorganic material} , the treatment was carried out in the same manner as in Example 1, except that ZnI ₂ was not used. After the reaction was completed, the gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography, and the conversion rate and selectivity were calculated in consideration of each. The selectivity of _CF2 =CFCF= _CF2 is 63 mol
%, _CF2 =CF- _CF2 - _CF2H 25 mol%, HCF2 _{- CF2} - _CF2 - _CF2H 2.2 mol%, _ICF2 - _CF2 - _CF2 - _CF2H 2.1
mol %, and other by-products (CF ₃ CF=CHCF ₃ etc.) totaling 7.7 mol %.

Example 8: BrCF2 _- CF2-CF2 _- CF2Br _; ZnI2 _1.6 mol%
The treatment was carried out as in Example 1, except that _{BrCF2 - CF2} -CF2- _CF2Br was used as substrate instead of ClCF2-CFCl- _CF2 - _CF2I . After the reaction was completed, the gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography, and the conversion rate and selectivity were calculated in consideration of each of them.
The conversion rate was 100 mol%, and the selectivity of each component was 96 mol% for _CF2 =CFCF= _CF2 and _CF2 =CF- _CF2 - _CF2H .
is 3.0 mol%, _HCF2 - _CF2 - _CF2 - _CF2H is 0.51 mol%, _BrCF2 - _CF2 - _CF2 - _CF2H is 0.28 mol%, and other by-products ( _CF3CF = _CHCF3 etc.) was 0.21 mol % in total.

_{Reference Example} 3: BrCF2 _- CF2- _{CF2 - CF2Br ;} no iodine-containing _{inorganic material} , the treatment was carried out in the same manner as in Example 1, except that ZnI ₂ was not used. After the reaction was completed, the gas phase, liquid phase, and reaction liquid in the collection cylinder were analyzed by gas chromatography, and the conversion rate and selectivity were calculated in consideration of each. The selectivity of _CF2 =CFCF= _CF2 is 76 mol%, _CF2 =CF- _CF2 - _CF2H is 13 mol%, _HCF2 - _CF2 - _CF2 - _CF2H is 1.9 mol%, _BrCF2 - _CF2 - _CF2 - _CF2H is
2.1 mol %, and other by-products (CF ₃ CF=CHCF ₃ etc.) totaling 7.0 mol %.

The results are shown in Tables 1-3.

Claims (14)

General formula (1):
_CF2 =CF-( _CF2 ) _n-4 -CF= _CF2 (1)
[In the formula, n represents an integer of 4 to 20. ]
A method for producing a perfluoroalkadiene compound represented by
In an organic solvent, in the presence of a nitrogen-containing compound, an iodine-containing inorganic material, and zinc or a zinc alloy,
General formula (2):
_CF2X1 - ^CFX2- ( _CF2 ) _n-4 ^{- CFX3} _-CF2X4 ⁽ 2)
[In the formula, n is the same as above. X ¹ , X ² , X ³ and X ⁴ are the same or different and represent a halogen atom. However, both ^X1 and ^X2 are not fluorine atoms, and both ^X3 and ^X4 are not fluorine atoms. ]
A production method comprising a reaction step of reacting a compound represented by 2. The production method according to claim 1, wherein the amount of the iodine-containing inorganic material used is 0.0005 mol or more per 1 mol of the zinc or zinc alloy, and the solubility of the organic solvent or less. The production method according to claim 1 or 2, wherein the iodine-containing inorganic material is iodine and/or metal iodide. 4. Any one of claims 1 to 3, wherein the reaction step includes a first mixing step of mixing a solution containing the iodine-containing inorganic material, the zinc or zinc alloy, and the organic solvent, and the nitrogen-containing compound. The manufacturing method described in the item. Claim 4, wherein in the first mixing step, the nitrogen-containing compound is added to the solution containing the zinc or zinc alloy at an addition rate of 0.1 to 600 mol/hour with respect to 1 mol of the zinc or zinc alloy. The manufacturing method described in . 6. The production method according to claim 4 or 5, wherein the reaction step includes a second mixing step of mixing the obtained mixture with the compound represented by the general formula (2) after the first mixing step. . In the second mixing step, the mixture obtained in the first mixing step is added with the general formula (
7. The production method according to claim 6, wherein the compound represented by 2) is added at an addition rate of 0.05 to 30 mol/hour with respect to 1 mol of the zinc or zinc alloy. Claims 4 to 7, wherein in the first mixing step, the solution containing the iodine-containing inorganic material, zinc or zinc alloy, and the organic solvent is mixed with the nitrogen-containing compound at a temperature of 50 to 200°C. The production method according to any one of. The production method according to any one of claims 1 to 8, wherein the nitrogen-containing compound is N,N-dimethylformamide. 10. Any one of claims 1 to 9, wherein the boiling point of the organic solvent is equal to or lower than the boiling point of the nitrogen-containing compound.
The manufacturing method described in the item. General formula (1):
_CF2 =CF-( _CF2 ) _n-4 -CF= _CF2 (1)
[In the formula, n represents an integer of 4 to 20. ]
A perfluoroalkadiene compound represented by
General formula (3):
_CF2 =CF-( _CF2 ) _n-4 - ^CFX3 - _CF2H (3)
[In the formula, n is the same as above. ^X3 represents a halogen atom. ]
A compound represented by
General formula (4A):
_CF2X1 ^{- CFX2-} ( _CF2 ) _n-4 -CF= _CF2 (4A)
[In the formula, n is the same as above. X ¹ and X ² are the same or different and represent a halogen atom. However, both X ¹ and X ² are not fluorine atoms. ]
A compound represented by and / or general formula (4B):
_CF2H - ^CFX2- ( _CF2 ) _n-4 - ^CFX3 - _CF2H (4B)
[In the formula, n is the same as above. ^X2 and ^X3 are the same or different and represent a halogen atom. ]
A compound represented by
General formula (5):
_CF2X1 - ^CFX2- ( _CF2 ) _n-4 - ^{CFX3 -} _CF2H (5)
[In the formula, n is the same as above. X ¹ , X ² and X ³ are the same or different and represent a halogen atom. However, both X ¹ and X ² are not fluorine atoms. ]
A perfluoroalkadiene composition containing a compound represented by The perfluoroalkadiene composition according to claim 11, wherein the content of the compound represented by the general formula (1) is 80 to 99.8 mol% with respect to the total amount of the perfluoroalkadiene composition being 100 mol%. . Claim 11, wherein the perfluoroalkadiene compound is hexafluorobutadiene.
Or the perfluoroalkadiene composition according to 12. Etching gas, refrigerant, heat transfer medium, foaming agent or resin monomer comprising the perfluoroalkadiene composition according to any one of claims 11 to 13.