Method for producing composition containing purified fluorine-containing ether compound

Abstract

To provide a composition comprising a purified fluorine-containing ether compound.SOLUTION: The present invention provides a composition comprising 1,1,2,3,3,3-hexafluoropropyl methyl ether (HFE-356mec), and CF3CF=CFOCH3 and / or CF2=CFCF2OCH3, wherein the total content of CF3CF=CFOCH3 and CF2=CFCF2OCH3 is 0.00001 mass% or more to 0.1 mass% or less relative to HFE-356mec, and the purity of HFE-356mec in the composition is more than 95 mass%.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a method for producing a composition containing a purified fluorine-containing ether compound.

Background Art

[0002] In recent years, hydrofluoroethers (HFEs) have attracted attention as alternatives to chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) because of their low global warming potential (GWP) and ozone depletion potential (ODP) and low toxicity. It is disclosed in Non-Patent Document 1 that 1,1,2,3,3,3-hexafluoropropyl methyl ether (HFE-356mec), which is a kind of HFE, can be obtained by the reaction of hexafluoropropene (HFP) and methanol in the presence of an alkali.

[0003]

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present disclosure provides a purified general formula (1) CHX X 2 CF2OX 3 (wherein X 1 and X 2 are the same or different and each represents a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and X 3 represents an alkyl group having 1 to 6 carbon atoms. However, X 1 and X 2 ​Neither of them will be a trifluoromethyl group. An object of the present invention is to provide a method for producing a composition containing a fluorine-containing ether compound represented by the following formula (1). **Means for Solving the Problems**

[0006] This disclosure includes the inventions described in the following items. Item 1. A method for producing a composition containing a purified fluorine-containing ether compound, comprising: (A) In the presence of a fluorine-containing ether compound represented by the general formula (1) CHX 1 X 2 CF2OX 3 (wherein X 1 and X 2 are the same or different and each represents a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and X 3 represents an alkyl group having 1 to 6 carbon atoms. However, both X 1 and X 2 will not both be trifluoromethyl groups.), a fluorine-containing olefin compound represented by the general formula (2) CX 1 X 2 =CF(CF2) n OX 3 (wherein n represents 0 or 1. X 1 , X 2 and X 3 are the same as defined above. However, when X 1 or X 2 is a trifluoromethyl group, n is 0, and both X 1 and X 2 will not both be trifluoromethyl groups.) is reacted with a halogenating agent and / or an oxidizing agent to convert the fluorine-containing olefin compound represented by the general formula (2) into a halogen adduct and / or an oxide, thereby obtaining a composition containing the fluorine-containing ether compound represented by the general formula (1) and the halogen adduct and / or the oxide; and (B) separating the halogen adduct and / or the oxide from the composition obtained in the step (A) to obtain a composition containing a purified fluorine-containing ether compound. Item 2. The production method according to claim 1, wherein the halogenating agent is a chlorinating agent and / or a brominating agent. Item 3. The production method according to claim 1 or 2, wherein, in the step (A), the reaction is carried out in a liquid phase. 。 Item 4. The production method according to any one of claims 1 to 3, wherein, in the step (B), the composition obtained in the step (A) is rectified in a rectification column to separate the halogen adduct and / or the oxide from the composition obtained in the step (A). Item 5. The production method according to any one of claims 1 to 4, wherein the fluorine-containing ether compound represented by the general formula (1) is 1,1,2,3,3,3-hexafluoropropyl methyl ether (HFE-356mec). Item 6. The production method according to any one of claims 1 to 5, wherein the fluorine-containing olefin compound represented by the general formula (2) is CF3CF = CFOCH3 and / or CF2 = CFCF2OCH3. Item 7. 1,1,2,3,3,3-hexafluoropropyl methyl ether (HFE-356mec), CF3CF = CFOCH3 and / or CF2 = CFCF2OCH3, and a composition containing the same. Item 8. The composition according to claim 7, wherein the total content of CF3CF = CFOCH3 and CF2 = CFCF2OCH3 is 0.1% by mass or less based on HFE-356mec. Item 9. Furthermore, it contains hydrogen fluoride, The composition according to claim 7 or 8, wherein the content of the hydrogen fluoride is 0.01% by mass or less based on HFE-356mec.

Advantages of the Invention

[0007] According to the production method of the present disclosure, a composition containing a purified fluorine-containing ether compound represented by the general formula (1) can be produced by a simple method.

Embodiments for Carrying Out the Invention

[0008] As a result of intensive studies, the present inventors have found that the above object can be achieved by utilizing the reaction of the fluorine-containing olefin compound represented by the above general formula (2) with a halogenating agent and / or an oxidizing agent.

[0009] Based on such findings, the present disclosure has been completed as a result of further studies. Hereinafter, embodiments included in the present disclosure will be described in detail.

[0010] In this specification, the expressions "containing" and "comprising" include the concepts of "containing", "comprising", "consisting essentially of", and "consisting only of".

[0011] In this specification, "purity" means the component ratio (mass%) by quantitative analysis using gas chromatography (GC).

[0012] In this specification, "reflux ratio" means the molar flow rate ratio of the reflux liquid to the distillate (reflux liquid / distillate).

[0013] The pressure described in this specification is in gauge pressure units unless otherwise specified. That is, atmospheric pressure is expressed as 0.0 MPa.

[0014] In this specification, "A and / or B" means either one of A and B, or both A and B.

[0015] In this specification, the "alkyl group having 1 to 6 carbon atoms" means a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group.

[0016] 1. Process for producing a composition containing a refined fluorine-containing ether compound A method for producing a composition containing a purified fluorine-containing ether compound of the present disclosure (hereinafter, also simply referred to as "the production method of the present disclosure") includes the following steps (A) and (B) in this order. Hereinafter, the production method of the present disclosure will be described in the order of steps (A) and (B).

[0017] Step (A) Step (A) is carried out in the presence of a fluorine-containing ether compound represented by the general formula (1) CHX 1 X 2 CF2OX 3 (wherein X 1 and X 2 are the same or different and each represents a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and X 3 represents an alkyl group having 1 to 6 carbon atoms. However, both X 1 and X 2 will not both be trifluoromethyl groups.) and a fluorine-containing olefin compound represented by the general formula (2) CX 1 X 2 =CF(CF2) n OX 3 (wherein n represents 0 or 1. X 1 and X 2 are the same or different and each represents a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and X 3 represents an alkyl group having 1 to 6 carbon atoms. However, when X 1 or X 2 is a trifluoromethyl group, n is 0, and both X 1 and X 2 will not both be trifluoromethyl groups.) are reacted with a halogenating agent and / or an oxidizing agent to convert the fluorine-containing olefin compound represented by the general formula (2) into a halogen adduct and / or an oxide, and obtain a composition containing the fluorine-containing ether compound represented by the general formula (1), a halogen adduct of the fluorine-containing olefin compound represented by the general formula (2), and / or an oxide of the fluorine-containing olefin compound represented by the general formula (2).

[0018] In the present disclosure, the fluorine-containing ether compound is represented by the general formula (1) CHX1 X 2 CF2OX 3 (wherein X 1 、X 2 and X 3 are the same as defined above.) is represented by. Specifically, CF3CHFCF2OX 3 、CHF2CF2OX 3 、CH2FCF2OX 3 、CH3CF2OX 3 etc. are exemplified (in each case, X 3 represents an alkyl group having 1 to 6 carbon atoms).

[0019] The fluorine-containing ether compound represented by the general formula (1) is preferably at least one compound selected from the group consisting of CF3CHFCF2OCH3, CHF2CF2OCH3, CH2FCF2OCH3 and CH3CF2OCH3. Among these, CF3CHFCF2OCH3 (1,1,2,3,3,3 - hexafluoropropyl methyl ether: HFE - 356mec) is more preferred.

[0020] In the present disclosure, the fluorine-containing olefin compound is represented by the general formula (2) CX 1 X 2 =CF(CF2) n OX 3 (wherein X 1 、X 2 、X 3 and n are the same as defined above.) is represented by. Specifically, CF3CF=CFOX 3 、CF2=CFCF2OX 3 、CF2=CFOX 3 、CHF=CFOX 3 、CH2=CFOX 3 etc. are exemplified (in each case, X 3 represents an alkyl group having 1 to 6 carbon atoms).

[0021] The fluorine-containing olefin compound represented by the general formula (2) is preferably at least one compound selected from the group consisting of CF3CF=CFOCH3, CF2=CFCF2OCH3, CF2=CFOCH3, CHF=CFOCH3, and CH2=CFOCH3. Among these, at least one of CF3CF=CFOCH3 and CF2=CFCF2OCH3 is more preferable.

[0022] As the halogenating agent, a chlorinating agent and / or a brominating agent is preferable.

[0023] Examples of the chlorinating agent include chlorine gas; hypochlorites such as sodium hypochlorite; chlorites such as sodium chlorite; chlorates such as sodium chlorate; interhalogen compounds containing chlorine, etc. Examples of the interhalogen compound containing chlorine include chlorine monofluoride, etc. Among these chlorinating agents, chlorine gas or sodium hypochlorite is preferable. The chlorinating agents can be used alone or in combination of two or more.

[0024] Examples of the brominating agent include bromine; bromates such as potassium bromate; interhalogen compounds containing bromine, etc. Examples of the interhalogen compound containing bromine include bromine monofluoride, etc. Among these brominating agents, bromine is preferable. The brominating agents can be used alone or in combination of two or more.

[0025] Examples of the oxidizing agent include hydrogen peroxide solution; oxygen; hypochlorites such as sodium hypochlorite; chlorites such as sodium chlorite; chlorates such as sodium chlorate; bromates such as sodium bromide and potassium bromide, etc. The oxidizing agents can be used alone or in combination of two or more.

[0026] Chlorine gas; hypochlorites such as sodium hypochlorite; chlorites such as sodium chlorite; and chlorates such as sodium chlorate can be used as both a chlorinating agent and an oxidizing agent. Also, bromine; and bromates such as potassium bromate can be used as both a brominating agent and an oxidizing agent.

[0027] In step (A), it is more preferable that the halogenating agent and / or the oxidizing agent is at least one selected from the group consisting of chlorine gas, bromine, and sodium hypochlorite.

[0028] In step (A), when the fluorinated olefin compound represented by the general formula (2) reacts with a halogenating agent in the presence of the fluorinated ether compound represented by the general formula (1), a halogen is added to the fluorinated olefin compound represented by the general formula (2). As a result, a composition containing the fluorinated ether compound represented by the general formula (1) and the halogenated adduct of the fluorinated olefin compound represented by the general formula (2) is obtained. Further, in step (A), when the fluorinated olefin compound represented by the general formula (2) reacts with an oxidizing agent in the presence of the fluorinated ether compound represented by the general formula (1), the fluorinated olefin compound represented by the general formula (2) is converted into an oxide. As a result, a composition containing the fluorinated ether compound represented by the general formula (1) and the oxide of the fluorinated olefin compound represented by the general formula (2) is obtained. Furthermore, in step (A), when the fluorinated olefin compound represented by the general formula (2) reacts with a halogenating agent and an oxidizing agent in the presence of the fluorinated ether compound represented by the general formula (1), a composition containing the fluorinated ether compound represented by the general formula (1), the halogenated adduct of the fluorinated olefin compound represented by the general formula (2), and the oxide of the fluorinated olefin compound represented by the general formula (2) is obtained.

[0029] In step (A), when converting the fluorine-containing olefin compound represented by the general formula (2) into a halogen adduct and / or an oxide by reacting the fluorine-containing olefin compound represented by the general formula (2) with a halogenating agent and / or an oxidizing agent, it is preferable to coexist the fluorine-containing ether compound represented by the general formula (1) and hydrogen fluoride. When the fluorine-containing ether compound represented by the general formula (1) and hydrogen fluoride coexist in step (A), the amount of hydrogen fluoride is preferably 0.1% by mass or less, more preferably 0.075% by mass or less, still more preferably 0.05% by mass or less, based on the fluorine-containing ether compound represented by the general formula (1). When the fluorine-containing ether compound represented by the general formula (1) and hydrogen fluoride coexist in step (A), the amount of hydrogen fluoride is preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more, still more preferably 0.001% by mass or more, based on the fluorine-containing ether compound represented by the general formula (1). - For the ether compound, it is preferably 0.0001% by mass or more, more preferably 0.0005% by mass or more, still more preferably 0.001% by mass or more.

[0030] Examples of the halogen adduct include a chlorine adduct of the fluorine-containing olefin compound represented by the general formula (2), a compound in which hydrogen contained in the fluorine-containing olefin compound represented by the general formula (2) is substituted with chlorine or bromine, a bromine adduct of the fluorine-containing olefin compound represented by the general formula (2), and the like. Examples of the oxide include a compound in which the fluorine-containing olefin compound represented by the general formula (2) is oxidized and converted into a carboxylic acid.

[0031] Before the reaction in step (A), the content ratio of the fluorine-containing olefin compound represented by the general formula (2) is preferably 2% by mass or less based on the fluorine-containing ether compound represented by the general formula (1).

[0032] The reaction in step (A) is preferably a contact reaction between the fluorine-containing olefin compound represented by the general formula (2) and a halogenating agent and / or an oxidizing agent.

[0033] The supply amount of the halogenating agent is preferably 1 mol or more and preferably 2 mol or less per 1 mol of the fluorine-containing olefin compound represented by the general formula (2). The supply amount of the oxidizing agent is preferably 1 mol or more and preferably 2 mol or less per 1 mol of the fluorine-containing olefin compound represented by the general formula (2).

[0034] In the reaction of step (A), from the viewpoint of suppressing heat generation, an inert gas component such as nitrogen gas may coexist.

[0035] The reaction in step (A) can be carried out in the liquid phase or the gas phase. As a case of carrying out in the liquid phase, in the reactor, a halogenating agent and / or an oxidizing agent is introduced into the crude liquid containing the fluorine-containing ether compound represented by the general formula (1) and the fluorine-containing olefin compound represented by the general formula (2), and the crude liquid is brought into contact with the halogenating agent and / or the oxidizing agent. As a case of carrying out in the gas phase, in the reactor, a method of bringing the gasified crude liquid into contact with the halogenating agent and / or the oxidizing agent can be mentioned. From the viewpoint of improving the recovery rate of the fluorine-containing ether compound represented by the general formula (1), the reaction in step (A) is preferably carried out in the liquid phase.

[0036] When the reaction in step (A) is carried out in the liquid phase, in the presence of the fluorine-containing ether compound represented by the general formula (1), it is preferable to carry out light irradiation to bring the fluorine-containing olefin compound represented by the general formula (2) into contact with the halogenating agent and / or the oxidizing agent. As a light source for carrying out light irradiation, it is preferable to use a light source capable of irradiating ultraviolet rays having a wavelength of about 300 nm or more and 400 nm or less. Specifically, an arc lamp containing mercury, argon or xenon, and a filament lamp containing tungsten and halogen can be mentioned. The halogenating agent and / or the oxidizing agent may be continuously supplied under light irradiation, or after introducing a predetermined amount into the reactor at once, light irradiation may be started.

[0037] When the reaction in step (A) is carried out in the liquid phase, the reaction temperature is preferably 0 °C or higher, preferably 30 °C or lower, and more preferably less than 20 °C. Also, the reaction pressure is preferably 0.0 MPa or higher, preferably 0.5 MPa or lower, and more preferably under atmospheric pressure. Further, the reaction time is preferably 0.1 hour or longer, and preferably 24 hours or shorter.

[0038] When the reaction in step (A) is carried out in the gas phase, it is preferably carried out in the presence of a catalyst. Examples of the catalyst include activated carbon, zeolite, alumina, silica alumina, and the like.

[0039] When the reaction in step (A) is carried out in the gas phase, the reaction temperature is preferably 70 °C or higher, and preferably 300 °C or lower. Also, the reaction pressure is preferably -0.05 MPa or higher, and preferably 0.50 MPa or lower. Further, the reaction time is preferably 0.1 hour or longer, and preferably 24 hours or shorter.

[0040] Examples of the reactor used in the liquid phase reaction in step (A) include glass containers, glass-lined containers, resin-lined containers, SUS containers, and the like. Examples of the reactor used in the gas phase reaction in step (A) include glass containers, glass-lined containers, resin-lined containers, SUS containers, and the like.

[0041] Step (B) Step (B) is a step of separating the halogen adduct of the fluorine-containing olefin compound represented by the general formula (2) and / or the oxide of the fluorine-containing olefin compound represented by the general formula (2) from a composition containing the fluorine-containing ether compound represented by the general formula (1) obtained in step (A) and the halogen adduct of the fluorine-containing olefin compound represented by the general formula (2) and / or the oxide of the fluorine-containing olefin compound represented by the general formula (2), to obtain a composition containing the purified fluorine-containing ether compound represented by the general formula (1).

[0042] In the composition obtained through the steps of step (B), the purity of the fluorine-containing ether compound represented by the general formula (1) is usually more than 95% by mass, preferably 97% by mass or more, more preferably 99% by mass or more, even more preferably 99.3% by mass or more, and particularly preferably 99.5% by mass or more.

[0043] In the composition obtained through the steps of step (B), the purity of the fluorine-containing olefin compound represented by the general formula (2) is usually 0.1% by mass or less, preferably 0.05% by mass or less, more preferably 0.01% by mass or less, even more preferably 0.005% by mass or less, and particularly preferably 0.001% by mass or less.

[0044] The separation operation preferably employs distillation (particularly preferably rectification). Distillation (particularly rectification) can use a distillation column (particularly a rectification column) having a multi-stage number of theoretical plates, and either continuous distillation or batch distillation can be adopted. The pressure for performing distillation (particularly rectification) is preferably -0.05 MPa or more and preferably 0.10 MPa or less. When distilling (particularly rectifying) within such a pressure range, the boiling point difference between the fluorine-containing ether compound represented by the general formula (1) and the halogen addition product of the fluorine-containing olefin compound represented by the general formula (2) and / or the oxide of the fluorine-containing olefin compound represented by the general formula (2) can be increased (for example, the boiling point difference can be made 10 °C or more), so that the separation operation and separation accuracy are improved.

[0045] The number of theoretical plates of the distillation column (particularly the rectification column) used in distillation (particularly rectification) is preferably 2 or more and preferably 30 or less. The reflux ratio of the distillation column (particularly the rectification column) used in distillation (particularly rectification) is preferably 2 or more and preferably 50 or less. The distillation column (particularly the rectification column) is preferably formed of a material resistant to corrosion such as glass, stainless steel (SUS), Hastelloy (HASTALLOY), Inconel (INCONEL), Monel (MONEL), etc., and more preferably formed of SUS. Examples of the packing used in the distillation column (particularly the rectification column) include Raschig rings and McMahon packing.

[0046] According to the manufacturing method of the present disclosure including the above steps (A) and (B), a purified general formula (1) CHX 1 X 2 CF2OX 3 (wherein X 1 and X 2 are the same or different and represent a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and X 3 represents an alkyl group having 1 to 6 carbon atoms. However, both X 1 and X 2 will not both be trifluoromethyl groups.) represented by a composition containing a fluorine-containing ether compound can be obtained.

[0047] 2. Composition The composition of the present disclosure contains 1,1,2,3,3,3-hexafluoropropyl methyl ether (HFE-356mec) as an essential component, and further contains at least one of CF3CF=CFOCH3 and CF2=CFCF2OCH3. In the present disclosure, a composition containing HFE-356mec and CF3CF=CFOCH3 and / or CF2=CFCF2OCH3 can be used as a cleaning agent.

[0048] The composition of the present disclosure preferably contains HFE-356mec, CF3CF=CFOCH3, and CF2=CFCF2OCH3. In this case, from the viewpoints of the stability of the composition, the stability of the material brought into contact with the composition, etc., the total content of CF3CF=CFOCH3 and CF2=CFCF2OCH3 is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, still more preferably 0.01% by mass or less, with respect to HFE-356mec. Also, from the viewpoints of the stability of the composition, cost reduction during the production of HFE-356mec, etc., the total content of CF3CF=CFOCH3 and CF2=CFCF2OCH3 is preferably 0.00001% by mass or more, more preferably 0.00005% by mass or more, still more preferably 0.0001% by mass or more, with respect to HFE-356mec.

[0049] The composition of the present disclosure may contain hydrogen fluoride. When the composition of the present disclosure contains hydrogen fluoride, the content of hydrogen fluoride is preferably 0.01% by mass or less, more preferably 0.001% by mass or less, based on HFE-356mec.

[0050] The composition of the present disclosure may contain a trace amount of water. The water content in the composition of the present disclosure is preferably 0.3% by mass or less, more preferably 0.05% by mass or less, based on the total amount of HFE-356mec and CF3CF=CFOCH3 and / or CF2=CFCF2OCH3. When the composition of the present disclosure contains a trace amount of moisture, the decomposition of the fluorine-containing olefin compound is suppressed, so that the stability of the composition is improved.

Examples

[0051] Examples are shown below to more specifically explain the embodiments of the present disclosure. However, the present disclosure is not limited to these examples. Hereinafter, "room temperature" means 20 to 25°C.

[0052] (Example 1-1: Liquid-phase contact reaction using chlorine gas) A 1 L glass container was charged with 300 g of a crude product containing 94.4% by mass of HFE-356mec, 1.38% by mass of a fluorine-containing olefin compound (1.28% by mass of CF3CF=CFOCH3 and 0.10% by mass of CF2=CFCF2OCH3), and 0.035% by mass of hydrogen fluoride. Then, while cooling the glass container to 0°C, chlorine gas was supplied at 20 ml / min for 30 minutes, and the contact reaction between the fluorine-containing olefin compound in the crude product and chlorine gas was carried out in the liquid phase at a pressure of 0.0 MPa. Thereafter, 25 g of a 10% by mass aqueous sodium sulfite solution was added and stirred for 30 minutes. After confirming that the chlorine gas had disappeared with potassium iodide starch paper, the organic phase was separated. The separated organic phase was washed with water to obtain 246 g of a composition containing HFE-356mec (purity 95.5% by mass) (recovery rate of HFE-356mec: 82%).

[0053] (Example 1-2: Rectification in a rectification column) A device equipped with a glass rectification column (5 theoretical plates) made of SUS as a filler, a condenser (the temperature of the cooling water in the condenser: 0°C to 5°C), and a fractionator was prepared in a 500 mL glass container. 220 g of the composition (246 g) containing HFE-356mec obtained in Example 1-1 was added to the device, and the total reflux state was maintained for 1 hour. Then, the reflux ratio was started from 50, and rectification was completed when 177 g of the fraction was recovered. The obtained fraction was analyzed by GC, and it was confirmed that the purity of HFE-356mec was 99.9% by mass (recovery rate 80%), and the purity of the above fluorine-containing olefin compound was 0.002% by mass. Also, the purity of hydrogen fluoride was 0.0002% by mass. In addition, in the GC analysis of the obtained fraction, the presence of the chlorine adduct of the fluorine-containing olefin compound and the oxide of the fluorine-containing olefin compound could not be confirmed.

[0054] (Example 1-3: Liquid-phase contact reaction using chlorine gas) 300 g of a crude product containing HFE-356mec with a purity of 93.0% by mass, a fluorine-containing olefin compound with a purity of 1.84% by mass (CF3CF=CFOCH3 with a purity of 1.74% by mass and CF2=CFCF2OCH3 with a purity of 0.10% by mass), and hydrogen fluoride with a purity of 0.035% by mass was charged into a 1 L SUS container. Then, under room temperature conditions, chlorine gas was supplied at 173 mL / min for 10 minutes, and the contact reaction between the fluorine-containing olefin compound in the crude product and chlorine gas was carried out in the liquid phase at a pressure of 0.3 MPa. Then, 25 g of a 10% by mass aqueous sodium sulfite solution was added and stirred for 30 minutes. After confirming that the chlorine gas had disappeared with potassium iodide starch paper, the organic phase was separated. The separated organic phase was washed with water to obtain 285 g of a composition containing HFE-356mec (purity of HFE-356mec: 94.5% by mass, recovery rate of HFE-356mec: 96.5%).

[0055] (Example 1-4: Gas-phase contact reaction using chlorine gas) A 1-L SUS container was charged with 300 g of a crude product containing HFE-356mec with a purity of 93.0% by mass, a fluorinated olefin compound with a purity of 1.84% by mass (CF3CF=CFOCH3 with a purity of 1.74% by mass and CF2=CFCF2OCH3 with a purity of 0.10% by mass), and hydrogen fluoride with a purity of 0.035% by mass. The reactor was heated to 70 °C, and chlorine gas was supplied at 173 mL / min for 10 minutes. The contact reaction between the fluorinated olefin compound in the crude product and chlorine gas was carried out in the gas phase at a pressure of 0.4 MPa. Then, 25 g of a 10% by mass aqueous sodium sulfite solution was added and stirred for 30 minutes. After confirming that the chlorine gas had disappeared using potassium iodide starch paper, the organic phase was separated. The separated organic phase was washed with water, and 282 g of a composition containing HFE-356mec was obtained (purity of HFE-356mec: 94.2% by mass, recovery rate of HFE-356mec: 95.2%).

[0056] (Example 1-5: Rectification in a rectification column) A 500-mL glass container was prepared with a glass rectification column (5 theoretical plates) using a SUS packing material, a condenser (temperature of cooling water in the condenser: 0 °C to 5 °C), and a fractionator. 220 g of the composition containing HFE-356mec (261 g) obtained in Examples 1-3 was added to the apparatus, and the total reflux state was maintained for 1 hour. Then, fractionation was started at a reflux ratio of 50, and rectification was completed when 99 g of the fraction was recovered. When the obtained fraction was analyzed by GC, it was confirmed that the purity of HFE-356mec was 99.9% by mass (recovery rate 45%), the purity of the above-mentioned fluorinated olefin compound was 0.003% by mass, and the purity of hydrogen fluoride was 0.0002% by mass. In addition, in the GC analysis of the obtained fraction, the presence of the chlorine adduct of the fluorinated olefin compound and the oxide of the fluorinated olefin compound could not be confirmed.

[0057] (Example 2-1: Contact reaction in the liquid phase using sodium hypochlorite) 220 g of a crude product containing 94.4 mass% of HFE-356mec, 1.37 mass% of a fluorine-containing olefin compound (1.27 mass% of CF3CF=CFOCH3 and 0.10 mass% of CF2=CFCF2OCH3), and 0.035 mass% of hydrogen fluoride, and 66 g of a 12 mass% aqueous sodium hypochlorite solution were charged into a 1-L glass container. Then, the mixture was stirred under reflux at 54°C for 1.5 hours, and the contact reaction between the fluorine-containing olefin compound in the crude product and sodium hypochlorite was carried out in the liquid phase at a pressure of 0.0 MPa. After stirring even after 1.5 hours, the residual amount of the fluorine-containing olefin compound (purity: 0.474 mass%) was confirmed by GC. Then, 33 g of a 12 mass% aqueous sodium hypochlorite solution was added three times at 1-hour intervals (a total of 99 g was added). However, since the residual amount of the fluorine-containing olefin compound (purity: 0.07 mass%) was confirmed by GC, the mixture was stirred for 16 hours after returning to room temperature. Thereafter, 15.5 g of a 10 mass% aqueous sodium sulfite solution was added and stirred for 30 minutes. After confirming that sodium hypochlorite had disappeared using potassium iodide starch paper, the organic phase was separated. The separated organic phase was washed with water, and 186 g of a composition containing HFE-356mec was obtained (purity of HFE-356mec: 95.7 mass%, recovery rate of HFE-356mec: 85%).

[0058] (Example 2-2: Contact reaction in the liquid phase using sodium hypochlorite) A 1-L glass container was charged with 220 g of a crude product containing HFE-356mec with a purity of 94.4% by mass, a fluorinated olefin compound with a purity of 1.37% by mass (CF3CF=CFOCH3 with a purity of 1.27% by mass and CF2=CFCF2OCH3 with a purity of 0.10% by mass), and hydrogen fluoride with a purity of 0.035% by mass, and 66 g of a 12% by mass aqueous sodium hypochlorite solution. Then, the mixture was stirred at room temperature for 22 hours, and the contact reaction between the fluorinated olefin compound in the crude product and sodium hypochlorite was carried out in the liquid phase at a pressure of 0.0 MPa. Thereafter, 15.5 g of a 10% by mass aqueous sodium sulfite solution was added and stirred for 30 minutes. After confirming that sodium hypochlorite had disappeared using potassium iodide starch paper, the organic phase was separated. The separated organic phase was washed with water, and 183 g of a composition containing HFE-356mec was obtained (yield of HFE-356mec: 83%).

[0059] (Example 2-3: Rectification in a rectification column) A 500-mL glass container was prepared with a rectification column (5 theoretical plates) using a SUS filler, a condenser (temperature of cooling water in the condenser: 0°C to 5°C), and a fractionator. 90 g of the composition containing HFE-356mec (183 g) obtained in Example 2-2 was added, and the total reflux state was maintained for 1 hour. Thereafter, fractional distillation was started at a reflux ratio of 50, and rectification was completed when 71 g of a fraction was recovered. When the obtained fraction was analyzed by GC, it was confirmed that the purity of HFE-356mec was 99.9% by mass (recovery rate 79%), the purity of the above-mentioned fluorinated olefin compound was 0.003% by mass, and the purity of hydrogen fluoride was 0.0002% by mass. In addition, in the GC analysis of the obtained fraction, the presence of a chlorine adduct of the fluorinated olefin compound and an oxide of the fluorinated olefin compound could not be confirmed.

[0060] (Example 2-4: Rectification in a rectification column) A device equipped with a rectification column (two theoretical plates) using a filler made of SUS, a condenser (the temperature of the cooling water in the condenser: 0°C to 5°C), and a fractionator was prepared in a 500 mL glass container. 90 g of the composition (183 g) containing HFE-356mec obtained in Example 2-2 was added, and the total reflux state was maintained for 1 hour. Then, fractional distillation was started at a reflux ratio of 50, and rectification was completed when 69 g of the fraction was recovered. The obtained fraction was analyzed by GC, and it was confirmed that the purity of HFE-356mec was 99.8% by mass (recovery rate 76%), the purity of the above-mentioned fluorine-containing olefin compound was 0.003% by mass, and the purity of hydrogen fluoride was 0.0002% by mass. In addition, in the GC analysis of the obtained fraction, the presence of a chlorine adduct of the fluorine-containing olefin compound and an oxide of the fluorine-containing olefin compound could not be confirmed.

[0061] (Example 3-1: Contact reaction in the liquid phase using bromine) 2918 g of a crude product containing 93% by mass of HFE-356mec, 1.38% by mass of a fluorine-containing olefin compound (1.28% by mass of CF3CF=CFOCH3 and 0.10% by mass of CF2=CFCF2OCH3), and 0.025% by mass of hydrogen fluoride was charged into a 5 L reactor. Next, the reactor was placed in an ice bath and cooled until the internal temperature reached 5°C or lower, and 133 g of bromine was dropped into the reactor. After the dropping was completed, the inside of the reactor was returned to room temperature and stirred at room temperature for 10 hours to carry out the contact reaction between the fluorine-containing olefin compound in the crude product and bromine in the liquid phase. Then, the reaction solution obtained was transferred to a 5 L plastic bucket, 500 g of ice water and 50 g of sodium bicarbonate were added and stirred. After confirming that it was basic with pH test paper, sodium thiosulfate (40 g) was added. Then, it was confirmed that the excess bromine was removed using potassium iodide starch paper. Next, when the reaction solution was transferred to a separating funnel and the lower layer was taken out, the product was a colorless and transparent liquid. Mass spectrometry of the product was performed by gas chromatography / mass spectrometry (GC / MS), and structural analysis was performed by NMR spectrum. From the results of mass spectrometry and structural analysis, it was confirmed that the purity of HFE-356mec was 96.1% by mass and the recovery rate of HFE-356mec was 96% (yield 2793 g).

[0062] (Example 3-2: Rectification in a rectification column) The product obtained in Example 3-1 was transferred to a 3 L round-bottom flask equipped with a mantle heater and an internal thermometer in advance, and a glass Oldershaw-type rectification column (20 theoretical plates) equipped with a condenser and a fractionator was attached to the upper part of the round-bottom flask. The mantle heater was set to 100 °C, and the total reflux state was maintained for 1 hour. Then, fractionation was started at a reflux ratio of 50, and purification was terminated when 2725 g of fraction was recovered. The obtained fraction was subjected to mass spectrometry by GC / MS and structural analysis by NMR spectrum. From the results of mass spectrometry and structural analysis, the recovery rate of HFE-356mec was 93% calculated from Example 3-1, and the purity of HFE-356mec was 99.95 mass%. Also, the purity of the fluorinated olefin compound was 0.003 mass%. In addition, in the GC analysis of the obtained fraction, the presence of the bromine adduct of the fluorinated olefin compound and the oxide of the fluorinated olefin compound could not be confirmed.

[0063] (Example 4) A glass flask equipped with a Dimroth condenser was charged with a solvent containing HFE-356mec, CF3CF=CFOCH3 and hydrogen fluoride (the content of CF3CF=CFOCH3 was 0.004 mass% based on HFE-356mec, and the content of hydrogen fluoride was 0.0002 mass% based on HFE-356mec). Further, test pieces of iron, copper, zinc, and aluminum were placed in the flask, and the mixture was heated to 53 °C and refluxed under atmospheric pressure in air to observe the stability of the above solvent and each test piece. After 72 hours, no acid was generated in the solvent, and no change such as corrosion was observed in any of the test pieces.

[0064] (Example 5) Observation was carried out under the same conditions as in Example 4 except that the content of CF3CF=CFOCH3 was 0.004 mass% based on HFE-356mec and 0.3 mass% of water was added to the solvent. After 72 hours, no acid was generated in the solvent, and no change such as corrosion was observed in any of the test pieces.

[0065] (Example 6) Observation was carried out under the same conditions as in Example 4, except that the content of CF3CF=CFOCH3 was 0.009% by mass with respect to HFE-356mec, the content of hydrogen fluoride was 0.0004% by mass with respect to HFE-356mec, and 0.03% by mass of water was added to the solvent. After 72 hours, no acid was generated in the solvent, and no changes such as corrosion were observed in any of the test pieces.

[0066] (Comparative Example 1) A solvent containing HFE-356mec, CF3CF=CFOCH3, CF2CF=CF2OCH3 and hydrogen fluoride (the content of CF3CF=CFOCH3 was 1.38% by mass with respect to HFE-356mec, the content of CF2CF=CF2OCH3 was 0.8% by mass with respect to HFE-356mec, and the content of hydrogen fluoride was 0.0004% by mass with respect to HFE-356mec) was placed in a glass flask equipped with a Dimroth condenser, and 0 .3% by mass of water was added. Further, test pieces of iron, copper, zinc, and aluminum were placed in the flask, heated to 53 °C and refluxed in air under atmospheric pressure to observe the stability of the above solvent and each test piece. After 72 hours, acid was generated in the solvent, and corrosion was observed in all test pieces.

Claims

**Claim 1** A composition comprising 1,1,2,3,3,3 - hexafluoropropyl methyl ether (HFE - 356mec) and CF ３ CF = CFOCH ３ and / or CF ２ = CFCF ２ OCH ３ and wherein the purity of HFE - 356mec in the composition is more than 95% by mass. CF ３ CF = CFOC H ３ and CF ２ = CFCF ２ OCH ３ the total content of which is 0.00001% by mass or more and 0.1% by mass or less with respect to HFE-356mec, A composition. **Claim 2** Further containing hydrogen fluoride, The composition according to claim 1, wherein the content of the hydrogen fluoride is 0.01% by mass or less based on HFE - 356mec.