Patent Description:
Hydrofluoroethers (HFEs) have attracted attention as alternatives to chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) because of their low global warming potential (GWP), low ozone depletion potential (ODP), and low toxicity.

<CIT> discloses a cleaning agent containing an azeotropic mixture-like composition containing <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexafluoroisopropyl methyl ether (HFE-356mmz), which is an HFE, and hexafluoroisopropanol (HFIP).

<CIT> discloses that an azeotrope-like composition containing <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexafluoro-<NUM>-methoxy-propane, which is another HFE, and <NUM>-bromopropane is usable in cleaning processes as a refrigerant.

<CIT> discloses an azeotropic mixture-like composition containing HFE-356mmz and HFIP. <CIT> relates to a method for producing high-purity HFE-356mmz, comprising contacting a composition containing HFE-356mmz, HFIP and at least one compound selected from dimethyl ether, halomethane and methyl p-toluenesulfonate with a silica-alumina solid adsorbent. <CIT> describes method of washing polyvinylidene fluoride resin using a fluorine-containing cleaning agent having a boiling point of above <NUM> and being at least one compound selected from chlorofluoroalkanes and (per)fluorinated alkanes, cycloalkanes, ethers, alcohols and ketones. <CIT> concerns a working medium for a boiling-type cooler comprising HFE-356mmz as a main component.

An object of the present disclosure is to provide a novel composition containing <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexafluoroisopropyl methyl ether (HFE-356mmz) and/or <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexafluoropropyl methyl ether (HFE-356mec), and a fluorine oil. Another object of the present disclosure is to provide a solvent composition or cleaning composition that contains HFE-356mmz and/or HFE-356mec for removing a fluorine oil.

The present disclosure provides a composition (also referred to as "the present composition" hereinafter) comprising.

the total amount of (A) and (B) being ≥ <NUM> mass%, based on the total of the composition.

Also, the present disclosure provides the use of the present composition in a coating agent which is a mixture existing in liquid form at room temperature and is applied to an article to form a coating film for protecting or imparting luster to the surface of the article.

Furthermore, the present disclosure provides a cleaning method comprising removing a fluorine oil (B) as defined in the present composition above, using a cleaning agent which contains HFE-356mmz and/or HFE-356mec.

Yet further, the present disclosure provides a dissolution method comprising dissolving a fluorine oil (B) as defined in the present composition above, using a solvent which contains HFE-356mmz and/or HFE-356mec.

The present disclosure provides a novel composition containing HFE-356mmz and/or HFE-356mec and a fluorine oil.

The present disclosure includes the following embodiments.

The present composition contains component (A) and component (B). The component (A) is <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexafluoroisopropyl methyl ether (HFE-356mmz) and/or <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexafluoropropyl methyl ether (HFE-356mec). The component (B) is a fluorine oil.

The fluorine oil, which is component (B), is at least one compound selected from (i) perfluoropolyether compounds, (ii) compounds which contain a perfluoropolyether group and a functional group and which are selected from monocarboxylic acid compounds, dicarboxylic acid compounds and silane compounds, and (III) polymers of chlorotrifluoroethylene having a number average molecular weight of ≤ <NUM>,<NUM>.

Examples of perfluoropolyether compounds include compounds having a constituent unit of the formula - (OCnF2n)- (<NUM>) wherein n is <NUM>, <NUM>, <NUM>, or <NUM>.

Commercial products of perfluoropolyether compounds include Krytox (registered trademark) GPL oil, <NUM> oil, vacuum pump oil (trade names, produced by Chemours), Demnum S-<NUM>, Demnum S-<NUM>, Demnum S-<NUM> (trade names, produced by Daikin Industries, Ltd. ), Fomblin M, Fomblin Z, Fomblin Y (trade names, produced by Solvay Specialty Polymers Japan K. ), and BARRIERTA (trade name, produced by NOK Klüber Co.

Examples of monocarboxylic acid compounds containing a perfluoropolyether group include compounds of formula (<NUM>) Rf<NUM>-PFPE<NUM>-Z<NUM>-COOH wherein PFPE<NUM> is a group of the formula: -(OC<NUM>F<NUM>)a-(OC<NUM>F<NUM>)b-(OC<NUM>F<NUM>)c-(OC<NUM>F<NUM>)d-(OC<NUM>F<NUM>)e-(OCF<NUM>)f-wherein a - f each independently are an integer of <NUM>-<NUM>, (a+b+c+d+e+f) is at least <NUM>, and the order of the repeating units in parentheses accompanied by a, b, c, d, e, or f is optional Form; Rf<NUM> is C<NUM>-<NUM>-alkyl optionally substituted with one or more F; and Z<NUM> is a single bond or a divalent organic group.

Examples of mono- and dicarboxylic acid compounds containing a perfluoropolyether group include compounds of formula (<NUM>) X1-O-Rf-Y wherein -Rf is a perfluoropolyoxyalkylene chain with a number average molecular weight of <NUM>-<NUM>,<NUM> containing a unit of (C<NUM>F<NUM>O), (CF<NUM>O), a (C<NUM>F<NUM>O) type (wherein the (C<NUM>F<NUM>O) unit can be a unit represented by formula -(CF<NUM>CF(CF<NUM>)O) or (CF(CF<NUM>)CF<NUM>O)-), (CF<NUM>(CF<NUM>)zCF<NUM>O)- (wherein is an integer of <NUM> or <NUM>), or -CR4R5CF<NUM>CF<NUM>O- (wherein R4 and R5 are identical or different and selected from H, Cl, or, for example, C<NUM>-<NUM> perfluoroalkyl) with the unit statistically distributed along the main chain; and -X1 and Y is a terminal group and contains at least one carboxyl group, provided that when one terminal group contains only one of these groups, the other terminal group contains a CF<NUM> group.

Specific examples of dicarboxylic acid compounds containing a perfluoropolyether group include HOOCCF<NUM>-O-[(CF<NUM>CF<NUM>O)<NUM>-(CF<NUM>O)<NUM>]-CF<NUM>COOH produced by Daikin Industries, Ltd. Specific examples of monocarboxylic acid compounds containing a perfluoropolyether group include CF<NUM>-O-[(CF<NUM>CF<NUM>O)<NUM>-(CF<NUM>O)<NUM>]-CF<NUM>COOH produced by Daikin Industries, Ltd. Examples of commercial products of silane compounds containing a perfluoropolyether group include KY-<NUM> series produced by Shin-Etsu Chemical Co. (e.g., KY-<NUM>, KY-<NUM>, KY-<NUM>), OPTOOL (registered trademark) DSX, OPTOOL (registered trademark) AES, OPTOOL (registered trademark) UF503, and OPTOOL (registered trademark) UD509 produced by Daikin Industries, Ltd. , and Afluid (registered trademark) S550 produced by AGC Inc. Specific examples of silane compounds containing a perfluoropolyether group include OPTOOL (registered trademark) UD500 produced by Daikin Industries, Ltd.

Commercial products of polymers of chlorotrifluoroethylene having a number average molecular weight of ≤ <NUM>,<NUM> include DAIFLOIL #<NUM>, DAIFLOIL #<NUM>, DAIFLOIL #<NUM>, DAIFLOIL #<NUM>, DAIFLOIL #<NUM>, and DAIFLOIL #<NUM> (trade names, produced by Daikin Industries, Ltd.

In the present disclosure, from the standpoint of achieving sufficient lubricity and sufficient coating film strength, component (B) for use is preferably a fluorine oil with a kinematic viscosity at <NUM> of <NUM>-<NUM> cst or a fluorine oil with a kinematic viscosity at <NUM> of <NUM>-<NUM> cst. In the present disclosure, from the standpoint of further increasing lubricity and coating film strength, component (B) for use is more preferably a fluorine oil with a kinematic viscosity at <NUM> of <NUM>-<NUM> cst or a fluorine oil with a kinematic viscosity at <NUM> of <NUM>-<NUM> cst.

In the present disclosure, preferably, the content of component (A) is <NUM>-<NUM> mass%, and the content of component (B) is <NUM>-<NUM> mass% based on the total amount of components (A) and (B). When the contents of components (A) and (B) are within these ranges, components (A) and (B) in the composition exhibit excellent solubility, resulting in a uniform composition. In the present specification, the total amount of components (A) and (B) means that the sum of the content of components (A) and (B) in the composition is <NUM> mass%.

In the present disclosure, more preferably, the content of component (A) is <NUM>-<NUM> mass%, and the content of component (B) is <NUM>-<NUM> mass%, based on the total amount of components (A) and (B).

In the present disclosure, still more preferably, the content of component (A) is <NUM>-<NUM> mass%, and the content of component (B) is <NUM>-<NUM> mass%, based on the total amount of components (A) and (B).

In the present disclosure, particularly preferably, the content of component (A) is <NUM>-<NUM> mass%, and the content of component (B) is <NUM>-<NUM> mass%, based on the total amount of components (A) and (B).

As described in Comparative Example <NUM> later, from the standpoint of dissolving HFE-356mmz in a fluorine oil, the present composition contains no HFIP.

In the present composition, the total amount of components (A) and (B) in the total amount of the composition taken as <NUM> mass% is ≥ <NUM> mass%, preferably ≥ <NUM> mass%.

It is the most preferable that the present composition consists of components (A) and (B) (with the proviso that unavoidable impurities other than components (A) and (B) are allowed to be present).

It has been unknown that HFE-356mmz and HFE-356mec each exhibit excellent miscibility with a fluorine oil. However, the inventors of the present disclosure, as a result of trial and error of numerous combinations of HFE and oil, surprisingly found that a composition of HFE-356mmz or HFE-356mec with a fluorine oil does not become turbid even when the content of the fluorine oil is set to such a high concentration as described above and becomes transparent due to the high miscibility of HFE-356mmz or HFE-356mec with the fluorine oil.

In the present specification, "transparent" means that the composition is uniform and not turbid.

The present composition can be suitably used as a coating agent because of the excellent miscibility of HFE-356mmz or HFE-356mec with a fluorine oil and the moderately high boiling point of these mixtures.

To achieve the excellent miscibility, the present composition has a boiling point of preferably <NUM>-<NUM>, and more preferably <NUM>-<NUM>. When the present composition having a boiling point within these temperature ranges is used in a coating agent, the composition will exhibit excellent solubility with limited evaporation.

In the present specification, the term "coating agent" refers to a mixture that exists in a liquid form at room temperature and that is applied to an article to form a coating film mainly for the purpose of, for example, protecting or imparting luster to the surface of the article.

Another aspect of the present disclosure is a coating method including applying the present composition.

The present composition may contain, in addition to HFE-356mmz or HFE-356mec, at least one member selected from additional solvents other than HFE-356mmz or HFE-356mec, antioxidants, stabilizers, preservatives, and surfactants.

Additional solvents for use can be selected from a wide range of solvents such as alkane compounds, alkene compounds, chloroalkane compounds, chloroalkene compounds, hydrofluoroalkane compounds, fluoroalkene compounds, chlorofluoroalkene compounds, and alcohol compounds, according to the properties to be added. However, hexafluoroisopropanol (HFIP) is not preferable as such an additional solvent in the present disclosure. For example, for the purpose of dissolving mineral oil, <NUM>,<NUM>-dichloroethylene (chloroalkene compound) or <NUM>,<NUM>-dichloro-<NUM>,<NUM>,<NUM>-trifluoropropene (chlorofluoroalkene compound) can be added. Isopropyl alcohol (IPA), <NUM>-butanol, or <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-dodecafluoro-<NUM>-heptanol (alcohol compounds), for example, can also be added. In the present disclosure, additional solvents are preferably an alcohol compound. The alcohol compound is preferably at least one member selected from isopropyl alcohol (IPA), <NUM>-butanol, and <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-dodecafluoro-<NUM>-heptanol, and more preferably isopropyl alcohol (IPA). If an additional solvent is added, the present composition contains such an additional solvent in an amount of preferably <NUM>-<NUM> mass%, more preferably <NUM>-<NUM> mass%, and still more preferably <NUM> mass%, based on <NUM> mass% of the composition.

The stabilizers become functional as an acid acceptor or an antioxidant by exerting a stabilization effect. Major stabilization effects include the effect of preventing the decomposition of HFE-356mmz or HFE-356mec by capturing radicals generated in a system, and the acid-accepting effect of preventing further decomposition of HFE-356mmz or HFE-356mec caused by an acid by capturing the acid generated in a system. Such stabilizers for use are selected from a wide range of known stabilizers. In particular, from the standpoint of effectively reducing metal corrosion by the composition, the stabilizer for use is preferably at least one stabilizer selected from unsaturated alcohol-based stabilizers, nitro-based stabilizers, amine-based stabilizers, phenol-based stabilizers, and epoxy-based stabilizers.

The unsaturated alcohol-based stabilizer for use can be selected from a wide range of known such stabilizers. For example, the unsaturated alcohol-based stabilizer for use is at least one member selected from <NUM>-buten-<NUM>-ol, <NUM>-buten-<NUM>-ol, <NUM>-propen-<NUM>-ol, <NUM>-propen-<NUM>-ol, <NUM>-methyl-<NUM>-buten-<NUM>-ol, <NUM>-methyl-<NUM>-buten-<NUM>-ol, <NUM>-methyl-<NUM>-buten-<NUM>-ol, <NUM>-hexen-<NUM>-ol, <NUM>,<NUM>-hexadien-<NUM>-ol, and oleyl alcohol.

The nitro-based stabilizer for use can be selected from a wide range of known such stabilizers. Examples of aliphatic nitro compounds include nitromethane, nitroethane, <NUM>-nitropropane, and <NUM>-nitropropane. For example, the aromatic nitro compound for use is at least one member selected from nitrobenzene, o-, m-, or p-dinitrobenzene, o-, m-, or p-nitrotoluene, dimethyl nitrobenzene, m-nitroacetophenone, o-, m-, or p-nitrophenol, o-nitroanisole, m-nitroanisole, and p-nitroanisole.

The amine-based stabilizer for use can be selected from a wide range of known such stabilizers. For example, the amine-based stabilizer for use is at least one member selected from pentylamine, hexylamine, diisopropylamine, diisobutylamine, di-n-propylamine, diallylamine, triethylamine, N-methylaniline, pyridine, morpholine, N-methylmorpholine, triallylamine, allylamine, α-methylbenzylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, isopropylamine, dipropylamine, tripropylamine, butylamine, isobutylamine, dibutylamine, tributylamine, dibenzylamine, tribenzylamine, <NUM>-ethylhexylamine, aniline, N,N-dimethylaniline, N,N-diethylaniline, ethylenediamine, propylenediamine, diethylenetriamine, tetraethylenepentamine, benzylamine, dibenzylamine, diphenylamine, and diethylhydroxylamine.

The phenol-based stabilizer for use can be selected from a wide range of known such stabilizers. For example, the phenol-based stabilizer for use is at least one member selected from <NUM>,<NUM>-ditertiarybutyl-<NUM>-methylphenol, <NUM>-cresol, phenol, <NUM>,<NUM>-benzenediol, <NUM>-isopropyl-<NUM>-methylphenol, and <NUM>-methoxyphenol.

The epoxy-based stabilizer for use can be selected from a wide range of known such stabilizers. For example, the epoxy-based stabilizer for use is at least one member selected from butylene oxide, <NUM>,<NUM>-propylene oxide, <NUM>,<NUM>-butylene oxide, butyl glycidyl ether, diethylene glycol diglycidyl ether, and <NUM>,<NUM>-epoxy-<NUM>-phenoxy propane.

From the standpoint of more effectively preventing the decomposition of HFE-356mmz or HFE-356mec caused by various factors by using a combination of stabilizers having different stabilization effects, the stabilizer is preferably composed of the above-described epoxy-based stabilizer and at least one member selected from the unsaturated alcohol-based stabilizers, nitro-based stabilizers, and phenol-based stabilizers.

From the standpoint of more effectively limiting acid liberation from HFE-356mmz or HFE-356mec and reducing metal corrosion caused by the composition in a liquid form, the content of the stabilizer in the composition taken as <NUM> mass% is preferably <NUM> mass% or more, and more preferably <NUM> mass% or more. However, in consideration of avoiding unfavorable changes in physical properties of the composition in a liquid form due to an excessively added stabilizer, the content of the stabilizer in the composition taken as <NUM> mass% is <NUM> mass% or less.

Another aspect of the present disclosure is a cleaning method including removing a fluorine oil by using a cleaning agent containing HFE-356mmz and/or HFE-356mec.

Another aspect of the present disclosure is a dissolution method including dissolving a fluorine oil by using a solvent containing HFE-356mmz and/or HFE-356mec.

In these aspects, the fluorine oil to be removed or dissolved is at least one compound selected from the fluorine ois (B) as defined for the present composition above. Of these, perfluoropolyether compounds are preferable.

A composition containing HFE-356mmz and/or HFE-356mec (<NUM> parts by mass) mixed with preferably <NUM> parts by mass or less of a fluorine oil is usable as a solvent or cleaning agent. Additionally, for example, after the composition is used as a solvent or cleaning agent, the composition containing HFE-356mmz and/or HFE-356mec that remains mixed with a fluorine oil can be used as a solvent or cleaning agent again.

Embodiments of the present disclosure are described in more detail with reference to the following Examples.

The following fluorine oils were used in the Examples and Comparative Examples.

<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-Hexafluoroisopropyl methyl ether (HFE-356mmz) and fluorine oil (A1) were placed in a glass test tube to prepare a composition. Whether HFE-356mmz and fluorine oil (A1) were dissolved into each other at <NUM> was observed. The content of each component in the composition was HFE-356mmz: <NUM> mass%, fluorine oil (A1): <NUM> mass%. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A1) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A1) was confirmed to have been completely dissolved in HFE-356mmz.

A composition was prepared under the same conditions as in Example <NUM>, except that the content of HFE-356mmz was <NUM> mass%, and the content of fluorine oil (A1) was <NUM> mass%. Whether HFE-356mmz and fluorine oil (A1) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A1) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A1) was confirmed to have been completely dissolved in HFE-356mmz.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A2) was used instead of fluorine oil (A1). Whether HFE-356mmz and fluorine oil (A2) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A2) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A2) was confirmed to have been completely dissolved in HFE-356mmz.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A3) was used instead of fluorine oil (A1). Whether HFE-356mmz and fluorine oil (A3) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A3) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A3) was confirmed to have been completely dissolved in HFE-356mmz.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A4) was used instead of fluorine oil (A1). Whether HFE-356mmz and fluorine oil (A4) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A4) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A4) was confirmed to have been completely dissolved in HFE-356mmz.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A5) was used instead of fluorine oil (A1). Whether HFE-356mmz and fluorine oil (A5) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A5) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A5) was confirmed to have been completely dissolved in HFE-356mmz.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A6) was used instead of fluorine oil (A1). Whether HFE-356mmz and fluorine oil (A6) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A6) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A6) was confirmed to have been completely dissolved in HFE-356mmz.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A7) was used instead of fluorine oil (A1). Whether HFE-356mmz and fluorine oil (A7) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A7) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A7) was confirmed to have been completely dissolved in HFE-356mmz.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A8) was used instead of fluorine oil (A1). Whether HFE-356mmz and fluorine oil (A8) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A8) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A8) was confirmed to have been completely dissolved in HFE-356mmz.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A9) was used instead of fluorine oil (A1). Whether HFE-356mmz and fluorine oil (A9) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A9) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A9) was confirmed to have been completely dissolved in HFE-356mmz.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A10) was used instead of fluorine oil (A1). Whether HFE-356mmz and fluorine oil (A10) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mmz and fluorine oil (A10) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A10) was confirmed to have been completely dissolved in HFE-356mmz.

<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-Hexafluoropropyl methyl ether (HFE-356mec) and fluorine oil (A1) were placed in a glass test tube to prepare a composition. Whether HFE-356mec and fluorine oil were dissolved into each other at <NUM> was observed. The content of each component in the composition was HFE-356mec: <NUM> mass%, fluorine oil (A1): <NUM> mass%. The glass test tube was observed, and the composition of HFE-356mec and fluorine oil (A1) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A1) was confirmed to have been completely dissolved in HFE-356mec.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A2) was used instead of fluorine oil (A1). Whether HFE-356mec and fluorine oil (A2) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mec and fluorine oil (A2) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A2) was confirmed to have been completely dissolved in HFE-356mec.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A4) was used instead of fluorine oil (A1). Whether HFE-356mec and fluorine oil (A4) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mec and fluorine oil (A4) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A4) was confirmed to have been completely dissolved in HFE-356mec.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A5) was used instead of fluorine oil (A1). Whether HFE-356mec and fluorine oil (A5) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mec and fluorine oil (A5) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A5) was confirmed to have been completely dissolved in HFE-356mec.

HFE-356mec and fluorine oil (A6) were placed in a glass test tube to prepare a composition. Whether HFE-356mec and the fluorine oil were dissolved into each other at <NUM> was observed. The content of each component in the composition was HFE-356mec: <NUM> mass%, fluorine oil (A6): <NUM> mass%. The glass test tube was observed, and the composition of HFE-356mec and fluorine oil (A6) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A6) was confirmed to have been completely dissolved in HFE-356mec.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A7) was used instead of fluorine oil (A1). Whether HFE-356mec and fluorine oil (A7) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mec and fluorine oil (A7) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A7) was confirmed to have been completely dissolved in HFE-356mec.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A8) was used instead of fluorine oil (A1). Whether HFE-356mec and fluorine oil (A8) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mec and fluorine oil (A8) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A8) was confirmed to have been completely dissolved in HFE-356mec.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A9) was used instead of fluorine oil (A1). Whether HFE-356mec and fluorine oil (A9) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mec and fluorine oil (A9) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A9) was confirmed to have been completely dissolved in HFE-356mec.

A composition was prepared under the same conditions as in Example <NUM>, except that fluorine oil (A10) was used instead of fluorine oil (A1). Whether HFE-356mec and fluorine oil (A10) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of HFE-356mec and fluorine oil (A10) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A10) was confirmed to have been completely dissolved in HFE-356mec.

HFE-356mec and isopropyl alcohol (IPA) were placed in a glass test tube to prepare a mixture. The content of each component in the mixture was HFE-356mec: <NUM> mass%, IPA: <NUM> mass%. Additionally, fluorine oil (A1) was added to the glass test tube such that the compositional percentages of the mixture and fluorine oil (A1) were respectively <NUM> mass% and <NUM> mass%. Whether the mixture and fluorine oil (A1) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the composition of the mixture and fluorine oil (A1) was found to be a single layer and stay in a transparent liquid form. Thus, fluorine oil (A1) was confirmed to have been completely dissolved in the mixture.

HFE-356mmz and hexafluoroisopropanol (HFIP) were placed in a glass test tube to prepare a mixture. The content of each component in the mixture was HFE-356mmz: <NUM> mass%, HFIP: <NUM> mass%. Additionally, fluorine oil (A3) was added to the glass test tube such that the compositional percentages of the mixture and fluorine oil (A3) were respectively <NUM> mass% and <NUM> mass%. Whether the mixture and fluorine oil (A3) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the mixture and fluorine oil (A3) were confirmed to have not been dissolved into each other, and to have separated into two layers.

HFE-356mmz and HFIP were placed in a glass test tube to prepare a mixture. The content of each component in the mixture was HFE-356mmz: <NUM> mass%, HFIP: <NUM> mass%. Additionally, fluorine oil (A3) was added to the glass test tube such that the compositional percentages of the mixture and fluorine oil (A3) were respectively <NUM> mass% and <NUM> mass%. Whether the mixture and fluorine oil (A3) were dissolved into each other at <NUM> was observed. The glass test tube was observed, and the mixture and fluorine oil (A3) were confirmed to have not been dissolved into each other, and to have separated into two layers.

The results of Comparative Example <NUM> and Comparative Example <NUM> indicate that the mixture of HFE-356mmz and HFIP is not miscible with fluorine oil (A3).

In this Comparative Example, bis(<NUM>,<NUM>,<NUM>-trifluoroethyl) ether (HFE-356mff2, CF<NUM>CH<NUM>OCH<NUM>CF<NUM>) was used as an HFE compound. HFE-356mff2 is an HFE compound composed of four carbon atoms, six fluorine atoms, four hydrogen atoms, and one oxygen atom, in the same manner as HFE-356mmz and HFE-356mec in the present disclosure.

Bis(<NUM>,<NUM>,<NUM>-trifluoroethyl) ether (HFE-356mff2, CF<NUM>CH<NUM>OCH<NUM>CF<NUM>) and fluorine oil (A2) were placed in a glass test tube to prepare a composition. Whether HFE-356mff2 and fluorine oil (A2) were dissolved into each other at <NUM> was observed. The content of each component in the composition was HFE-356mff2: <NUM> mass%, fluorine oil (A2): <NUM> mass%. The glass test tube was observed, and HFE-356mff2 and fluorine oil (A2) were confirmed to have not been dissolved into each other, and to have separated into two layers.

The results of Comparative Example <NUM> indicate that HFE-356mff2 is not miscible with fluorine oil (A2). It was also confirmed that even HFE compounds composed of the same constituent elements with the same number of those elements, as with HFE-356mmz, HFE-356mec, and HFE-356mff2 (i.e., structural isomers), differ as to whether these compounds can dissolve in fluorine oil or not.

In this Comparative Example, <NUM>,<NUM>,<NUM>,<NUM>-tetrafluoro-<NUM>-(<NUM>, <NUM>, <NUM>-trifluoroethoxy) ethane (HFE-347pcf, CF<NUM>HCF<NUM>OCH<NUM>CF<NUM>) was used as an HFE compound.

HFE-347pcf and fluorine oil (A2) were placed in a glass test tube to prepare a composition. Whether HFE-347pcf and fluorine oil (A2) were dissolved into each other at <NUM> was observed. The content of each component in the composition was HFE-347pcf: <NUM> mass%, fluorine oil (A2): <NUM> mass%. The glass test tube was observed, and HFE-347pcf and fluorine oil (A2) were confirmed to have not been dissolved into each other, and to have separated into two layers.

HFE-356mmz and fluorine oil (A2) (lubricant) were mixed in a glass test tube to prepare a lubricant solution. The content of each component in the lubricant solution was HFE-356mmz: <NUM> mass%, fluorine oil (A2): <NUM> mass%. Subsequently, the lubricant solution was applied to the surface of an aluminum substrate to give an average thickness of <NUM>, and dried in air at <NUM> to <NUM>, thereby forming a lubricant coating film on the surface of the aluminum substrate. The lubricant coating film was visually observed and confirmed to be a uniform coating film.

HFE-356mmz and fluorine oil (A2) were mixed in a glass test tube to prepare a solution. The content of each component in the solution was HFE-356mmz: <NUM> mass%, fluorine oil (A2): <NUM> mass%. After the obtained solution was allowed to stand at <NUM> for <NUM> days, the state of the solution was visually observed. The solution was confirmed to have undergone no changes in color, and precipitation formation.

A glass testpiece (<NUM> × <NUM> × <NUM>) was immersed in fluorine oil (A2) for <NUM> seconds. The glass test piece was then immersed in <NUM> of HFE-356mmz for <NUM> minute at <NUM> and pulled out, followed by drying in air at room temperature for <NUM> minutes. As a result, fluorine oil (A2) remaining on the glass test piece was confirmed to have been removed.

HFE-356mec and fluorine oil (A2) (lubricant) were mixed in a glass test tube to prepare a lubricant solution. The content of each component in the lubricant solution was HFE-356mec: <NUM> mass%, fluorine oil (A2): <NUM> mass%. Subsequently, the lubricant solution was applied to the surface of an aluminum substrate to give an average thickness of <NUM> and dried in air at <NUM> to <NUM>, thereby forming a lubricant coating film on the surface of the aluminum substrate. The lubricant coating film was visually observed and confirmed to be a uniform coating film.

HFE-356mec and fluorine oil (A2) were mixed in a glass test tube to prepare a solution. The content of each component in the solution was HFE-356mmz: <NUM> mass%, fluorine oil (A2): <NUM> mass%. After the obtained solution was allowed to stand at <NUM> for <NUM> days, the state of the solution was visually observed. The solution was confirmed to have undergone no changes in color, and precipitation formation.

Claim 1:
A composition comprising
(A) <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexafluoroisopropyl methyl ether (HFE-356mmz) and/or <NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexafluoropropyl methyl ether (HFE-356mec), and
(B) a fluorine oil, which is at least one compound selected from
- perfluoropolyether compounds,
- mono- or dicarboxylic acid compounds or silane compound, each containing a perfluoropolyether group, and
- polymers of chlorotrifluoroethylene having a number average molecular weight of ≤ <NUM>,<NUM>,
the total amount of (A) and (B) being ≥ <NUM> mass%, based on the total of the composition.