Refrigerating machine oil composition and mixed composition for refrigerating machine

Abstract

To provide a refrigerating machine oil composition that can effectively suppress an increase in an acid value even when increasing a ratio of unsaturated fluorohydrocarbon compounds (HFO) in a refrigerant.SOLUTION: A refrigerating machine oil composition is used for a refrigerant comprising one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by a general formula (1) CxFyHz (1) [in the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, and z is an integer of 1 to 11, and has one or more carbon-carbon unsaturated bonds in a molecule.], and comprises: a base oil (A) containing one or more selected from a group consisting of polyalkylene glycols, copolymers of poly(oxy)alkylene glycol or mono-ether thereof and polyvinyl ether, and polyol esters; a modified silicone compound (B); and a specific epoxy compound (C), and a content of the modified silicone compound (B) is more than 0.10 mass% based on a total amount of the refrigerating machine oil composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a refrigerant oil composition and a refrigerant mixture composition for a refrigerator. In this specification, the "refrigerant mixture composition for a refrigerator" refers to a composition obtained by mixing a "refrigerant oil composition" and a "refrigerant".

Background Art

[0002] A refrigerator, such as a compression type refrigerator, generally includes at least a compressor, a condenser, an expansion mechanism (e.g., an expansion valve, etc.), and an evaporator, and has a structure in which a refrigerant mixture composition for a refrigerator circulates in a sealed system.

[0003] As a refrigerant used in a refrigerator such as a compression type refrigerator, instead of hydro-chloro-fluoro-carbon (HCFC) which has been conventionally used, a hydrocarbon fluoride compound with a low environmental load is being used. As the hydrocarbon fluoride compound, saturated hydrocarbon fluoride compounds (Hydro-Fluoro-Carbon; hereinafter also referred to as "HFC") such as 1,1,1,2-tetrafluoroethane (R134a), difluoromethane (R32), and 1,1-difluoroethane (R152a) are being used. In addition, the use of unsaturated hydrocarbon fluoride compounds (Hydro-Fluoro-Olefin; hereinafter also referred to as "HFO") such as 1,3,3,3-tetrafluoropropene (R1234ze), 2,3,3,3-tetrafluoropropene (R1234yf), and 1,2,3,3-tetrafluoropropene (R1234ye) with a low global warming potential (GWP) is also being considered (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, while unsaturated fluorinated hydrocarbon compounds (HFOs) have the advantage of a low global warming potential (GWP), they have the drawback of being inferior in thermal stability at high temperatures compared to saturated fluorinated hydrocarbon compounds (HFCs). Therefore, when the content of unsaturated fluorinated hydrocarbon compounds (HFOs) in the refrigerant increases, there is a problem that the acid value of the refrigerating machine oil composition tends to rise.

[0006] In recent years, refrigerating machines have been becoming more compact and higher in performance, and their operating conditions have become more severe than before. Therefore, the refrigerating machine oil composition is required to have a higher quality than ever. For example, while the amount of the refrigerating machine oil composition used in the equipment decreases with the compactification of the refrigerating machine, local high-temperature portions are likely to occur due to frictional heat or the like in the sliding part of the compressor due to the severer operating conditions. When the refrigerating machine oil composition is exposed to such portions, the acid value of the refrigerating machine oil composition is more likely to rise.

[0007] Therefore, even when the content of unsaturated fluorinated hydrocarbon compounds (HFOs) in the refrigerant is increased, it is desired to create a refrigerating machine oil composition that can effectively suppress the increase in acid value.

[0008] The present invention has been made in view of such demands, and an object thereof is to provide a refrigerating machine oil composition capable of effectively suppressing an increase in acid value even when the content of unsaturated fluorinated hydrocarbon compounds (HFOs) in the refrigerant is increased, and a refrigerating machine oil composition for a refrigerating machine containing the same.

Means for Solving the Problems

[0009] The present inventors intensively studied to solve the above problems. As a result, it was found that a refrigerating machine oil composition in which a modified silicone compound (B) and an epoxy compound (C) satisfying specific requirements are combined and the content of the modified silicone compound (B) is adjusted to a specific range can solve the above problems, and the present invention has been completed.

[0010] That is, the present invention relates to the following [1] to [3]. [1] The following general formula (1) C x F y H z ···(1) [In the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the molecule has at least one carbon-carbon unsaturated bond.] A refrigerant oil composition used in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by the formula, A base oil (A) containing one or more selected from the group consisting of polyalkylene glycols, poly(oxy)alkylene glycols or their monoethers and copolymers of polyvinyl ethers, and polyol esters, A modified silicone compound (B), An epoxy compound (C) satisfying the following requirements (α) and (β) and containing A refrigerant oil composition in which the content of the modified silicone compound (B) is more than 0.10% by mass based on the total amount of the refrigerant oil composition. ·Requirement (α): It has at least one divalent group represented by the following formula (2) in the molecule.

Chemical formula

Chemical formula

Advantages of the Invention

[0011] According to the present invention, even when the content of the unsaturated fluorinated hydrocarbon compound (HFO) in the refrigerant is increased, it is possible to provide a refrigerating machine oil composition capable of effectively suppressing an increase in acid value, and a refrigerating machine use mixed composition containing the refrigerating machine oil composition.

Embodiments for Carrying Out the Invention

[0012] The upper limit value and the lower limit value of the numerical range described in this specification can be arbitrarily combined. For example, when the numerical ranges "A to B" and "C to D" are described, the numerical ranges "A to D" and "C to B" are also included in the scope of the present invention. In addition, unless otherwise specified, the numerical range "lower limit value to upper limit value" described in this specification means that it is not less than the lower limit value and not more than the upper limit value. In addition, in this specification, the numerical values in the examples are numerical values that can be used as the upper limit value or the lower limit value.

[0013] [Aspect of Refrigeration Oil Composition] The refrigeration oil composition of the present embodiment is represented by the following general formula (1) C x F y H z ···(1) [In the general formula (1), x is an integer from 2 to 6, y is an integer from 1 to 11, z is an integer from 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds.] It is a refrigeration oil composition used for a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by The refrigeration oil composition of the present embodiment contains one or more base oils (A) selected from the group consisting of polyalkylene glycols, poly(oxy)alkylene glycols or monoethers thereof and copolymers of polyvinyl ethers, and polyol esters, a modified silicone compound (B), and an epoxy compound (C) satisfying the following requirements (α) and (β). ·Requirement (α): It has at least one divalent group represented by the following formula (2) in the molecule.

Chemical formula

[0014] The inventor has conducted various studies based on the idea that when the content of the unsaturated fluorinated hydrocarbon compound (HFO) in the refrigerant increases, one of the factors that easily increases the acid value of the refrigeration oil composition is the fluorine content generated by the decomposition of the unsaturated fluorinated hydrocarbon compound (HFO) in a high-temperature environment. As a result, it has been found that the refrigerant oil composition having the above configuration can suppress an increase in the fluorine concentration in the refrigerant oil composition caused by fluorine generated from the decomposition of an unsaturated fluorinated hydrocarbon compound (HFO) in a high-temperature environment, and can suppress an increase in the acid value of the refrigerant oil composition.

[0015] Regarding the mechanism by which the effects of the present invention are achieved, the details are not clearly understood, but it is presumed as follows, for example. That is, it is presumed that the refrigerant oil composition of the present embodiment suppresses an increase in the acid value of the refrigerant oil composition by at least one of the following actions (i) and (ii) due to having the above configuration. (i) An action of suppressing the decomposition of an unsaturated fluorinated hydrocarbon compound (HFO) in a high-temperature environment. (ii) An action of capturing fluorine (F - ) eluted into the refrigerant oil composition due to the decomposition of an unsaturated fluorinated hydrocarbon compound (HFO) in a high-temperature environment, and reducing the amount of fluorine (F - ) in the refrigerant oil composition.

[0016] In the following description, "base oil (A)", "modified silicone compound (B)", and "epoxy compound (C)" are also referred to as "component (A)", "component (B)", and "component (C)", respectively.

[0017] The refrigerant oil composition of the present embodiment may be composed only of component (A), component (B), and component (C), but may contain other components other than component (A), component (B), and component (C) within a range not departing from the gist of the present invention. In the refrigerant oil composition of the present embodiment, the total content of component (A), component (B), and component (C) is preferably 80% by mass or more, more preferably 85% by mass or more, and still more preferably 90% by mass or more based on the total amount of the refrigerant oil composition.

[0018] Hereinafter, each component contained in the refrigerant oil composition of the present embodiment will be described in detail.

[0019] <Base oil (A)> The refrigerant oil composition of this embodiment contains a base oil (A). In the refrigerant oil composition of this embodiment, the content of the base oil (A) is preferably 85.0% by mass or more, more preferably 90.0% by mass or more, and still more preferably 92.0% by mass or more, based on the total amount of the refrigerant oil composition, from the viewpoint of long-term stability required for the refrigerant oil composition. Also, from the viewpoint of facilitating the securing of the contents of component (B) and component (C) in the refrigerant oil composition, and further from the viewpoint of facilitating the securing of the contents of additives other than component (B) and component (C), it is preferably 99.0% by mass or less, more preferably 98.5% by mass or less, and still more preferably 98.0% by mass or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, it is preferably 85.0% by mass to 99.0% by mass, more preferably 90.0% by mass to 98.5% by mass, and still more preferably 92.0% by mass to 98.0% by mass.

[0020] The refrigerant oil composition of this embodiment contains, as the base oil (A), one or more selected from the group consisting of polyalkylene glycols (hereinafter also referred to as "PAG"), copolymers of poly(oxy)alkylene glycol or its monoether and polyvinyl ether (hereinafter also referred to as "ECP"), and polyol esters (hereinafter also referred to as "POE"). Hereinafter, PAG, ECP, and POE will be described in detail.

[0021] (Polyalkylene glycols (PAG)) As PAG, in the refrigerant oil composition, the PAG used as the base oil can be used without particular limitation, but it is preferably a polymer (A-1) represented by the following general formula (A-1). R 13a -[(OR 14a ) pa -OR 15a qa (A-1) ​In addition, when PAG is contained in the base oil (A), PAG may be used alone or in combination of two or more.

[0022] In the above general formula (A-1), R 13a represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, an acyl group having 2 to 10 carbon atoms, a divalent to hexavalent hydrocarbon group having 1 to 10 carbon atoms, or a substituted or unsubstituted heterocyclic group having 3 to 10 ring-forming atoms, and R 14a represents an alkylene group having 2 to 4 carbon atoms, and R 15a represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, an acyl group having 2 to 10 carbon atoms, or a substituted or unsubstituted heterocyclic group having 3 to 10 ring-forming atoms. Examples of the substituent that the heterocyclic group may have include an alkyl group having 1 to 10 (preferably 1 to 6, more preferably 1 to 3) carbon atoms; a cycloalkyl group having 3 to 10 (preferably 3 to 8, more preferably 5 or 6) ring-forming carbon atoms; an aryl group having 6 to 18 (preferably 6 to 12) ring-forming carbon atoms; a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom); a cyano group; a nitro group; a hydroxy group; an amino group, etc. These substituents may be further substituted by any of the above-mentioned substituents.

[0023] qa is an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 1. Note that qa is determined according to the number of bonding sites of R 13a in the above general formula (A-1). For example, when R 13a is an alkyl group or an acyl group, qa is 1, and when R 13a is a hydrocarbon group or a heterocyclic group and the valence of the group is 2, 3, 4, 5, or 6, qa is 2, 3, 4, 5, or 6, respectively. pa is the number of repeating units of OR 14a and is usually 1 or more, preferably a number such that pa × qa is 6 to 80. Note that the value of pa is a value appropriately set to adjust the kinematic viscosity of the base oil (A) to an appropriate range, and is not particularly limited as long as the kinematic viscosity is adjusted to an appropriate range. Incidentally, a plurality of Rs 14a may be the same or different from each other. Further, when qa is 2 or more, a plurality of Rs 15a in one molecule may be the same or different from each other.

[0024] R 13a and R 15a Examples of the monovalent hydrocarbon group represented by include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, and various decyl groups; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, various propylcyclohexyl groups, and various dimethylcyclohexyl groups; aryl groups such as phenyl group, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, and various naphthyl groups; arylalkyl groups such as benzyl group, various phenylethyl groups, various methylbenzyl groups, various phenylpropyl groups, and various phenylbutyl groups; etc. Incidentally, the above alkyl group may be either linear or branched. Here, "various" means a hydrocarbon group that is "linear, branched, or cyclic". For example, "various butyl groups" means various butyl groups such as "n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, cyclobutyl group". Further, a group having a cyclic structure includes positional isomers such as ortho-isomers, meta-isomers, and para-isomers, and the same applies hereinafter. R 13a and R 15a The number of carbon atoms of the monovalent hydrocarbon group represented by is preferably 1 to 10, more preferably 1 to 6, and still more preferably 1 to 3 from the viewpoint of compatibility with the refrigerant.

[0025] R 13a and R 15a The hydrocarbon group portion of the acyl group having 2 to 10 carbon atoms represented by may be either linear, branched, or cyclic. Examples of the alkyl group portion include the above-described Rs 13a and R15a Examples of the hydrocarbon group represented by [the formula] include those having 1 to 9 carbon atoms. R 13a and R 15a From the viewpoint of compatibility with the refrigerant, the number of carbon atoms in the acyl group represented by [the formula] is preferably 2 to 8, more preferably 2 to 6.

[0026] R 13a Examples of the 2- to 6-valent hydrocarbon group represented by [the formula] include a residue obtained by further removing 1 to 5 hydrogen atoms from the monovalent hydrocarbon group represented by the above-mentioned R 13a <the formula>, residues obtained by removing hydroxyl groups from polyhydric alcohols such as trimethylolpropane, glycerin, pentaerythritol, sorbitol, 1,2,3-trihydroxycyclohexane, 1,3,5-trihydroxycyclohexane, and the like. R 13a From the viewpoint of compatibility with the refrigerant, the number of carbon atoms in the 2- to 6-valent acyl group represented by [the formula] is preferably 2 to 10, more preferably 2 to 6.

[0027] R 13a and R 15a Examples of the above-mentioned heterocyclic group represented by [the formula] include an oxygen atom-containing heterocyclic group or a sulfur atom-containing heterocyclic group. The heterocyclic group may be a saturated ring or an unsaturated ring. Examples of the oxygen atom-containing heterocyclic group include residues obtained by removing 1 to 6 hydrogen atoms from oxygen atom-containing saturated heterocycles such as ethylene oxide, 1,3-propylene oxide, tetrahydrofuran, tetrahydropyran, hexamethylene oxide; and oxygen atom-containing unsaturated heterocycles such as acetylene oxide, furan, pyran, oxycycloheptatriene, isobenzofuran, isochromene. Examples of the sulfur atom-containing heterocyclic group include residues obtained by removing 1 to 6 hydrogen atoms from sulfur atom-containing saturated heterocycles such as ethylene sulfide, trimethylene sulfide, tetrahydrothiophene, tetrahydrothiopyran, hexamethylene sulfide; and sulfur atom-containing unsaturated heterocycles such as acetylene sulfide, thiophene, thiapyran, thiotripyridine.

[0028] R13a and R 15a The above-mentioned heterocyclic group represented by the formula may have a substituent, and the substituent may be bonded to the oxygen atom in the general formula (A-1). The substituent is as described above, but an alkyl group having 1 to 6 carbon atoms is preferable, and an alkyl group having 1 to 3 carbon atoms is more preferable. From the viewpoint of compatibility with the refrigerant, the number of ring-forming atoms of the above-mentioned heterocyclic group is preferably 3 to 10, more preferably 3 to 6.

[0029] R 14a Examples of the above-mentioned alkylene group represented by the formula include alkylene groups having 2 carbon atoms such as dimethylene group (-CH2CH2-), ethylene group (-CH(CH3)-); trimethylene group (-CH2CH2CH2-), propylene group (-CH(CH3)CH2-), propylidene group (-CHCH2CH3-), isopropylidene group (-C(CH3)2-) and other alkylene groups having 3 carbon atoms; tetramethylene group (-CH2CH2CH2CH2-), 1-methyltrimethylene group (-CH(CH3)CH2CH2-), 2-methyltrimethylene group (-CH2CH(CH3)CH2-), butylene group (-C(CH3)2CH2-) and other alkylene groups having 4 carbon atoms. Among these, R 14a is preferably a propylene group (-CH(CH3)CH2-).

[0030] In the polymer (A-1) represented by the above general formula (A-1), the content of the oxypropylene unit (-OCH(CH3)CH2-) is preferably 50 mol% or more, more preferably 65 mol% or more, still more preferably 80 mol% or more, based on the total amount (100 mol%) of oxyalkylene (OR 14a ) in the polymer (A-1).

[0031] Among the polymers (A-1) represented by the above general formula (A-1), at least one selected from the group consisting of polyoxypropylene glycol dimethyl ether represented by the following general formula (A-1-i), polyoxyethylene polyoxypropylene glycol dimethyl ether represented by the following general formula (A-1-ii), polyoxypropylene glycol monobutyl ether represented by the following general formula (A-1-iii), polyoxypropylene glycol monomethyl ether represented by the following general formula (A-1-iv), and polyoxypropylene glycol diacetate is preferred.

[0032]

Chemical formula

[0033]

Chemical formula

[0034]

Chemical formula

[0035]

Chemical formula

[0036] In the general formula (A-1-i), p1; in the general formula (A-1-ii), p2 and p3; in the general formula (A-1-iii), p4; and in the general formula (A-1-iv), p5 may be appropriately selected according to the kinematic viscosity required for the base oil (A).

[0037] (Copolymer (ECP) of poly(oxy)alkylene glycol or its monoether and polyvinyl ether) As the copolymer (ECP) of poly(oxy)alkylene glycol or its monoether and polyvinyl ether, a copolymer having a structural unit derived from poly(oxy)alkylene glycol or its monoether and a structural unit derived from polyvinyl ether may be used. Note that "poly(oxy)alkylene glycol" refers to both polyalkylene glycol and polyoxyalkylene glycol. Further, when ECP is contained in the base oil (A), ECP may be used alone or in combination of two or more. Among the ECPs, a copolymer (A-3-i) represented by the following general formula (A-3-i) or a copolymer (A-3-ii) represented by the general formula (A-3-ii) is preferable.

[0038] [Chemical formula]

[0039] In the general formulas (A-3-i) and (A-3-ii), R 1c , R 2c , and R 3c each independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. R 4c each independently represents a hydrocarbon group having 1 to 10 carbon atoms. R 5c each independently represents an alkylene group having 2 to 4 carbon atoms. R 6cEach independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alicyclic group having 3 to 20 ring-forming carbon atoms, a substituted or unsubstituted aromatic group having 6 to 24 ring-forming carbon atoms, an acyl group having 2 to 20 carbon atoms, or an oxygen-containing hydrocarbon group having 2 to 50 carbon atoms. Note that R 1c , R 2c , R 3c , R 4c , R 5c , and R 6c When there are a plurality of them, they may be the same or different for each structural unit. X C and Y C Each independently represents a hydrogen atom, a hydroxyl group, or a hydrocarbon group having 1 to 20 carbon atoms.

[0040] In the general formulas (A-3-i) and (A-3-ii), v is the average value of the number of units represented by OR 5c , represents a number of 1 or more, preferably a number of 1 to 50. When there are a plurality of OR 5c , the plurality of OR 5c may be the same or different from each other. Note that "OR 5c " represents a structural unit derived from poly(oxy)alkylene glycol or its monoether. In the general formula (A-3-i), u represents a number of 0 or more, preferably a number of 0 to 50, and w represents a number of 1 or more, preferably a number of 1 to 50. In the general formula (A-3-ii), x and y each independently represent a number of 1 or more, preferably a number of 1 to 50. Note that the values of v, u, w, x, and y only need to be adjusted according to the hydroxyl value required for the base oil (A), and there is no particular limitation.

[0041] Note that there is no particular limitation on the copolymerization form of the copolymer (A-3-i) and the copolymer (A-3-ii), and it may be a block copolymer, a random copolymer, or a graft copolymer.

[0042] R1c , R 2c , and R 3c Examples of the hydrocarbon group having 1 to 8 carbon atoms that can be selected as R in the general formula (A-1) include R 1a , R 2a , and R 3a The same as the monovalent hydrocarbon group having 1 to 8 carbon atoms that can be selected as R 1c , R 2c , and R 3c The number of carbon atoms of the hydrocarbon group that can be selected as is preferably 1 to 8, more preferably 1 to 6, and still more preferably 1 to 3. R 1c , R 2c , and R 3c Each is independently preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and still more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Also, it is preferable that at least one of R 1c , R 2c , and R 3c is a hydrogen atom, and it is more preferable that all of R 1c , R 2c , and R 3c are hydrogen atoms.

[0043] R 4c Examples of the hydrocarbon group having 1 to 10 carbon atoms that can be selected as include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, various propylcyclohexyl groups, various dimethylcyclohexyl groups; aryl groups such as phenyl group, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, various naphthyl groups; arylalkyl groups such as benzyl group, various phenylethyl groups, various methylbenzyl groups, various phenylpropyl groups, various phenylbutyl groups; etc. R 4c The number of carbon atoms of the hydrocarbon group that can be selected as R is preferably 1 to 8, more preferably 1 to 6, and still more preferably 1 to 4.

[0044] R 5c Examples of the alkylene group that can be selected as R in the general formula (A-1) include the same alkylene groups having 2 to 4 carbon atoms as those that can be selected as R 14a and preferably a propylene group (-CH(CH3)CH2-). In the copolymer (A-3-i) or the copolymer (A-3-ii), the content of oxypropylene units (-OCH(CH3)CH2-) is based on the total amount (100 mol%) of oxyalkylene (OR 5c ) which is a structural unit derived from poly(oxy)alkylene glycol or its monoether in the copolymer (A-3-i) or the copolymer (A-3-ii), preferably 50 mol% or more and 100 mol% or less, more preferably 65 mol% or more and 100 mol% or less, and still more preferably 80 mol% or more and 100 mol% or less.

[0045] R 6c Examples of the alkyl group having 1 to 20 carbon atoms that can be selected as R include a methyl group, an ethyl group, various propyl groups, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups, and the like. The number of carbon atoms of the alkyl group is preferably 1 to 10, more preferably 1 to 6, and still more preferably 1 to 3.

[0046] R 6c Examples of the alicyclic group having 3 to 20 carbon atoms forming a ring that can be selected as R include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, and the like. The number of carbon atoms forming the ring of the alicyclic group is preferably 3 to 10, more preferably 3 to 8, and still more preferably 3 to 6. The alicyclic group may have the aforementioned substituents, and an alkyl group is preferable as the substituent.

[0047] R 6c Examples of the aromatic group having 6 to 24 ring-forming carbon atoms that can be selected as R include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthryl group, and the like. The number of ring-forming carbon atoms of the aromatic group is preferably 6 to 18, more preferably 6 to 12. The aromatic group may have the aforementioned substituents, and an alkyl group is preferable as the substituent.

[0048] R 6c Examples of the acyl group having 2 to 20 ring-forming carbon atoms that can be selected as R include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a valeryl group, an isovaleryl group, a piperoyl group, a benzoyl group, a toluoyl group, and the like. The number of carbon atoms of the acyl group is preferably 2 to 10, preferably 2 to 8, and more preferably 2 to 6.

[0049] R 6c Examples of the oxygen-containing hydrocarbon group having 2 to 50 carbon atoms that can be selected as R include a methoxymethyl group, a methoxyethyl group, a methoxypropyl group, a 1,1-bismethoxypropyl group, a 1,2-bismethoxypropyl group, an ethoxypropyl group, a (2-methoxyethoxy)propyl group, a (1-methyl-2-methoxy)propyl group, and the like. The number of carbon atoms of the carbon-containing hydrocarbon group is preferably 2 to 20, more preferably 2 to 10, and still more preferably 2 to 6.

[0050] X C 、Y CExamples of hydrocarbon groups having 1 to 20 carbon atoms that can be selected include alkyl groups having 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 3 carbon atoms), substituted or unsubstituted cycloalkyl groups having 3 to 20 carbon atoms forming a ring (preferably 3 to 10 carbon atoms, more preferably 3 to 8 carbon atoms, still more preferably 3 to 6 carbon atoms), substituted or unsubstituted phenyl groups, substituted or unsubstituted naphthyl groups, arylalkyl groups having 7 to 20 carbon atoms (preferably 7 to 13 carbon atoms), and the like.

[0051] (Polyol esters (POE)) Examples of POE include esters of diols or polyols and fatty acids. When POE is contained in the base oil (A), POE may be used alone or in combination of two or more. POE is preferably an ester of a diol or a polyol having 3 to 20 hydroxyl groups and a fatty acid having 3 to 20 carbon atoms.

[0052] Examples of diols include ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 1,7-heptanediol, 2-methyl-2-propyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, and the like.

[0053] Examples of the polyol include polyhydric alcohols such as trimethylolethane, trimethylolpropane, trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol, di-(pentaerythritol), tri-(pentaerythritol), glycerin, polyglycerin (dimer to 20-mer of glycerin), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol glycerin condensate, adonitol, arabinitol, xylitol, mannitol; saccharides such as xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, raffinose, gentianose, melenditose; and partial etherified products thereof, methyl glucoside (glycoside), etc. Among these, hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol, di-(pentaerythritol), tri-(pentaerythritol) are preferred. Here, the hindered alcohol means an alcohol having a quaternary carbon atom bonded to four carbon atoms.

[0054] From the viewpoint of lubricating performance, the number of carbon atoms of the fatty acid is preferably 3 or more, more preferably 4 or more, still more preferably 5 or more, and even more preferably 8 or more. From the viewpoint of compatibility with the refrigerant, it is preferably 20 or less, more preferably 16 or less, still more preferably 12 or less, and even more preferably 10 or less. It should be noted that the number of carbon atoms of the above fatty acid includes the carbon atom of the carboxy group (-COOH) that the fatty acid has. The fatty acid may be either a linear fatty acid or a branched-chain fatty acid. From the viewpoint of lubricating performance, a linear fatty acid is preferred, and from the viewpoint of hydrolysis stability, a branched-chain fatty acid is preferred. Further, the fatty acid may be either a saturated fatty acid or an unsaturated fatty acid.

[0055] Examples of fatty acids include linear or branched ones such as isobutyric acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, eicosanoic acid, oleic acid, etc., or so-called neo acids in which the α-carbon atom is quaternary. More specifically, isobutyric acid, valeric acid (n-pentanoic acid), caproic acid (n-hexanoic acid), enanthic acid (n-heptanoic acid), caprylic acid (n-octanoic acid), pelargonic acid (n-nonanoic acid), capric acid (n-decanoic acid), oleic acid (cis-9-octadecenoic acid), isopentanoic acid (3-methylbutanoic acid), 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, etc. are preferred.

[0056] As for POE, it may be a partial ester in which some of the plurality of hydroxyl groups of the polyol remain unesterified, or a complete ester in which all hydroxyl groups are esterified. Further, POE may be a mixture of a partial ester and a complete ester, but a complete ester is preferred.

[0057] From the viewpoint of more excellent hydrolysis stability, esters of hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol, di-(pentaerythritol), tri-(pentaerythritol) are preferred as POE. Esters of neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol are more preferred. From the viewpoint of particularly excellent compatibility with the refrigerant and hydrolysis stability, esters of pentaerythritol are even more preferred.

[0058] Specific examples of preferred POEs include diesters of neopentyl glycol with one or more fatty acids selected from the group consisting of isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid; triesters of trimethylolethane with one or more fatty acids selected from the group consisting of isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid; triesters of trimethylolpropane with one or more fatty acids selected from the group consisting of isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid; triesters of trimethylolbutane with one or more fatty acids selected from the group consisting of isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid; tetraesters of pentaerythritol with one or more fatty acids selected from the group consisting of isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid, and the like.

[0059] Note that the ester with two or more fatty acids may be a mixture of esters of one fatty acid and a polyol in two or more species. Among POEs, esters of a mixture of two or more fatty acids and a polyol are preferred from the viewpoints of improving low-temperature characteristics and compatibility with the refrigerant.

[0060] (Preferred embodiments of base oil (A)) In the refrigerant oil composition of the present embodiment, from the viewpoint of facilitating the improvement of the effects of the present invention, the content of one or more selected from the group consisting of PAG, ECP, and POE in the base oil (A) is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, still more preferably 70% by mass to 100% by mass, even more preferably 80% by mass to 100% by mass, still even more preferably 90% by mass to 100% by mass, and even more preferably 100% by mass, based on the total amount of the base oil (A).

[0061] Here, from the viewpoint of more easily improving the effects of the present invention, in the refrigerant oil composition of the present embodiment, the base oil (A) preferably contains one selected from the group consisting of PAG, ECP, and POE alone. Here, from the viewpoint of further facilitating the improvement of the effects of the present invention, the content of one selected from the group consisting of PAG, ECP, and POE is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, still more preferably 70% by mass to 100% by mass, even more preferably 80% by mass to 100% by mass, still even more preferably 90% by mass to 100% by mass, and even more preferably 100% by mass, based on the total amount of the base oil (A).

[0062] (Other base oils) The base oil (A) may further contain other base oils as long as the effects of the present invention are not impaired. Examples of the other base oils include one or more selected from the group consisting of mineral oils and synthetic oils that do not fall under the aforementioned PAG, ECP, and POE.

[0063] Examples of the mineral oil include atmospheric residue obtained by atmospheric distillation of crude oil such as paraffinic crude oil, intermediate-base crude oil, or naphthenic crude oil; distillate oil obtained by vacuum distillation of these atmospheric residues; mineral oil obtained by subjecting the distillate oil to one or more refining treatments such as solvent dewaxing, solvent extraction, hydrocracking, solvent deoiling, catalytic deoiling, and hydrorefining; and the like. When the mineral oil is contained in the base oil (A), the mineral oil may be used alone or in combination of two or more.

[0064] Examples of synthetic oils that do not fall under the aforementioned PAG, ECP, and POE include, for example, polyvinyl ethers, polyesters, polycarbonates, hydrogenated α-olefin oligomers, alicyclic hydrocarbon compounds, alkylated aromatic hydrocarbon compounds, and oils produced by isomerizing GTL WAX (gas to liquid wax) produced by the Fischer-Tropsch process or the like. In addition, when a synthetic oil that does not fall under the aforementioned PAG, ECP, and POE is contained in the base oil (A), the synthetic oil may be used alone or in combination of two or more.

[0065] In the refrigerating machine oil composition of the present embodiment, from the viewpoint of the solubility of the component (B) and the component (C), it is preferable that the content of the mineral oil is low. Specifically, the content of the mineral oil is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 1% by mass or less, even more preferably 0.1% by mass or less, and still more preferably not containing mineral oil, based on the total amount of the base oil (A). Further, in the refrigerating machine oil composition of the present embodiment, from the viewpoint of facilitating the improvement of the effects of the present invention, it is preferable that the content of the synthetic oil that does not fall under PAG, ECP, and POE is low. Specifically, the content of the synthetic oil that does not fall under PAG, ECP, and POE is preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 1% by mass or less, even more preferably 0.1% by mass or less, and still more preferably not containing a synthetic oil that does not fall under PAG, ECP, and POE, based on the total amount of the base oil (A).

[0066] (Kinematic viscosity of base oil (A) at 100 °C) The kinematic viscosity of the base oil (A) at 100 °C is preferably 3 mm 2 / s or more, more preferably 4 mm 2 / s or more, still more preferably 5 mm 2 / s or more. Also, from the viewpoint of improving the compatibility with the refrigerant, it is preferably 50 mm 2 / s or less, more preferably 40 mm 2 / s or less, even more preferably 30 mm 2 / s or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, preferably 3 mm 2 / s to 50 mm 2 / s, more preferably 4 mm 2 / s to 40 mm 2 / s, even more preferably 5 mm 2 / s to 30 mm 2 / s. In this specification, the kinematic viscosity of base oil (A) at 100 °C is a value measured in accordance with JIS K2283:2000.

[0067] (Hydroxyl value of base oil (A)) From the viewpoint of improving the thermal stability of the refrigerant oil composition, the hydroxyl value of base oil (A) is preferably 30 mgKOH / g or less, more preferably 25 mgKOH / g or less, even more preferably 20 mgKOH / g or less, still more preferably 15 mgKOH / g or less, yet even more preferably 10 mgKOH / g or less, and even more preferably 5 mgKOH / g or less. Also, the hydroxyl value of base oil (A) is usually 0.1 mgKOH / g or more. In this specification, the hydroxyl value of base oil (A) is a value measured by the neutralization titration method in accordance with JIS K0070:1992.

[0068] (Number average molecular weight (Mn) of base oil (A)) From the viewpoints of improving lubrication performance (load-bearing performance) and sealing performance, the number average molecular weight (Mn) of base oil (A) is preferably 300 or more, more preferably 400 or more, and even more preferably 500 or more. Also, from the viewpoint of improving compatibility with the refrigerant, it is preferably 10,000 or less, more preferably 7,000 or less, and even more preferably 5,000 or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, preferably 300 to 10,000, more preferably 400 to 7,000, and even more preferably 500 to 5,000. In this specification, the number average molecular weight (Mn) of the base oil (A) is the value measured by the method described in the examples below.

[0069] <Modified silicone compound (B)> The refrigerant oil composition of this embodiment contains a modified silicone compound (B). By using the modified silicone compound (B) in combination with the epoxy compound (C), the elution of fluorine into the refrigerant oil composition due to the decomposition of the unsaturated fluorinated hydrocarbon compound (HFO) can be effectively suppressed, and the increase in the acid value of the refrigerant oil composition can be effectively suppressed. When the refrigerant oil composition does not contain the modified silicone compound (B), the increase in the acid value of the refrigerant oil composition cannot be sufficiently suppressed.

[0070] Here, in the refrigerant oil composition of this embodiment, the content of the modified silicone compound (B) needs to be more than 0.10% by mass based on the total amount of the refrigerant oil composition. When the content of the modified silicone compound (B) is 0.10% by mass or less, the elution of fluorine into the refrigerant oil composition due to the decomposition of the unsaturated fluorinated hydrocarbon compound (HFO) cannot be sufficiently suppressed, and the increase in the acid value of the refrigerant oil composition cannot be sufficiently suppressed. From the viewpoint of more easily improving the effect of suppressing the increase in the acid value of the refrigerant oil composition, the content of the modified silicone compound (B) is preferably 0.20% by mass or more, more preferably 0.30% by mass or more, still more preferably 0.40% by mass or more, and even more preferably 0.45% by mass or more based on the total amount of the refrigerant oil composition. The upper limit value of the content of the modified silicone compound (B) is not particularly limited, but from the viewpoint of obtaining an effect commensurate with the addition amount, it is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, still more preferably 3.0% by mass or less. Even more preferably, it is 2.0% by mass or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, preferably 0.20% by mass to 5.0% by mass, more preferably 0.30% by mass to 4.0% by mass, still more preferably 0.40% by mass to 3.0% by mass, and even more preferably 0.45% by mass to 2.0% by mass.

[0071] The modified silicone compound (B) can be used without particular limitation as long as it is a silicone compound in which at least one of the side chains and terminals of the polysiloxane skeleton in the unmodified silicone compound is modified. Note that the unmodified silicone compound is a silicone compound in which all of the side chains and terminals of the polysiloxane skeleton are composed of alkyl groups and no functional groups other than the alkyl groups are introduced into the side chains and terminals of the polysiloxane skeleton. As the unmodified silicone compound, preferably a compound represented by the following general formula (b1-1) can be mentioned. [Chemical formula]

[0072] In the above general formula (b1-1), R b1 and R b2 are each independently an alkyl group having 1 to 10 carbon atoms. nb is an integer of 1 or more. The number of carbon atoms of the alkyl group that can be selected as R b1 and R b2 is preferably 1 to 6, more preferably 1 to 3, still more preferably 1 to 2, and most preferably 1. Note that in the following description, R b1 will be referred to as the alkyl group of the side chain of the polysiloxane skeleton, and R b2 will be referred to as the alkyl group of the terminal of the polysiloxane skeleton.

[0073] Here, the above-mentioned "at least one of the side chains and terminals of the polysiloxane skeleton is modified" means that the alkyl group of the side chain of the polysiloxane skeleton in the unmodified silicone compound (R b1 in the following general formula (b1-1)) and the alkyl group of the terminal (R b2 in the above general formula (b1-1))means that at least one of them is substituted by a functional group other than the alkyl group.

[0074] Examples of the side-chain modified silicone include monoamine-modified silicone, diamine-modified silicone, special amino-modified silicone, epoxy-modified silicone, alicyclic epoxy-modified silicone, carbinol-modified silicone, mercapto-modified silicone, carboxyl-modified silicone, hydrogen-modified silicone, amino-polyether-modified silicone, epoxy-polyether-modified silicone, epoxy-aralkyl-modified silicone, polyether-modified silicone, aralkyl-modified silicone, fluoroalkyl-modified silicone, long-chain alkyl-modified silicone, higher fatty acid ester-modified silicone, higher fatty acid amide-modified silicone, polyether-long-chain alkyl-aralkyl-modified silicone, long-chain alkyl-aralkyl-modified silicone, and phenyl-modified silicone, etc. These may be used alone or in combination of two or more.

[0075] Examples of the terminal modified silicone include both-terminal modified silicone such as amino-modified silicone, epoxy-modified silicone, alicyclic epoxy-modified silicone, carbinol-modified silicone, methacryl-modified silicone, polyether-modified silicone, mercapto-modified silicone, carboxyl-modified silicone, phenol-modified silicone, silanol-modified silicone, acrylic-modified silicone, and carboxylic anhydride-modified silicone; and single-terminal modified silicone such as epoxy-modified silicone, carbinol-modified silicone, diol-modified silicone, methacryl-modified silicone, and carboxyl-modified silicone.

[0076] Examples of the side-chain and terminal modified silicone include side-chain amino-modified and both-terminal methoxy-modified silicone, side-chain epoxy-modified and both-terminal epoxy-modified silicone, etc.

[0077] Here, in the present embodiment, from the viewpoint of more easily improving the effects of the present invention, the modified silicone compound (B) preferably contains a side-chain modified silicone (B1) in which at least the side chains of the polysiloxane skeleton are modified. From the viewpoint of more easily improving the effects of the present invention, the content of the side-chain modified silicone (B1) in the modified silicone compound (B) is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, still more preferably 70% by mass to 100% by mass, even more preferably 80% by mass to 100% by mass, yet still more preferably 90% by mass to 100% by mass, still more preferably 95% by mass to 100% by mass, based on the total amount of the modified silicone compound (B).

[0078] Further, from the viewpoint of more easily further improving the effects of the present invention, the side-chain modified silicone (B1) preferably contains one or more selected from a side-chain modified silicone (B1a) having one or more epoxy groups in the side chain and a side-chain modified silicone (B1b) having one or more polyether groups in the side chain.

[0079] Examples of the side-chain modified silicone (B1a) having one or more epoxy groups in the side chain include side-chain modified epoxy-modified silicone, side-chain modified alicyclic epoxy-modified silicone, side-chain modified epoxy-polyether modified silicone, side-chain modified epoxy-aralkyl modified silicone; side-chain terminal modified side-chain epoxy-modified and both-terminal epoxy-modified silicone, etc.

[0080] As the side-chain modified silicone (B1a) having one or more epoxy groups in the side chain, commercially available products may be used. Examples of commercially available products of side-chain modified epoxy-modified silicone include X-22-343, KF-101, KF-1001, X-22-2000 manufactured by Shin-Etsu Chemical Co., Ltd.; SF8411 Fluid, SF8413 Fluid manufactured by Dow Corning Toray Co., Ltd., etc. Examples of commercially available products of side-chain modified alicyclic epoxy modified silicones include X-22-2046 and KF-102 manufactured by Shin-Etsu Chemical Co., Ltd.; BY16-839 Fluid and L-9300 manufactured by Dow Corning Toray Co., Ltd., etc. Examples of commercially available products of side-chain modified epoxy-polyether modified silicones include X-22-4741 and KF-1002 manufactured by Shin-Etsu Chemical Co., Ltd.; BY16-876 and FZ-3736 Fluid manufactured by Dow Corning Toray Co., Ltd., etc. Examples of commercially available products of side-chain modified epoxy-aralkyl modified silicones include KF-1005 manufactured by Shin-Etsu Chemical Co., Ltd., etc. Examples of commercially available products of side-chain terminal modified side-chain epoxy modified and both-terminal epoxy modified silicones include X-22-9002 manufactured by Shin-Etsu Chemical Co., Ltd., etc.

[0081] Among these, from the viewpoints of easy availability and effects, the side-chain modified silicone (B1a) having one or more epoxy groups in the side chain is preferably a side-chain modified epoxy modified silicone.

[0082] The side-chain modified silicone (B1a) having one or more epoxy groups in the side chain may be used alone or in combination of two or more.

[0083] Examples of the side-chain modified silicone (B1b) having one or more polyether groups in the side chain include side-chain modified polyether modified silicones, side-chain modified amino-polyether modified silicones, side-chain modified polyether-long chain alkyl-aralkyl modified silicones, etc. In this specification, silicone compounds having both an epoxy group and a polyether group in the side chain, such as side-chain modified epoxy-polyether modified silicones, are classified as side-chain modified silicones (B1a) having one or more epoxy groups in the side chain.

[0084] Commercially available products may be used as the side-chain modified silicone (B1b) having one or more polyether groups in the side chain. Examples of commercially available side-chain modified polyether-modified silicones include KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642, KF-643, KF-644, KF-6020, KF-6204, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6015, etc. manufactured by Shin-Etsu Chemical Co., Ltd., and FZ-2110, etc. manufactured by Dow Corning Toray Co., Ltd. Examples of commercially available side-chain modified amino polyether-modified silicones include X-22-3939A, etc. manufactured by Shin-Etsu Chemical Co., Ltd. Examples of commercially available side-chain modified polyether long-chain alkyl aralkyl-modified silicones include X-22-2516, etc. manufactured by Shin-Etsu Chemical Co., Ltd.

[0085] Among these, from the viewpoints of availability and effects, the side-chain modified silicone (B1b) having one or more polyether groups in the side chain is preferably a side-chain modified polyether-modified silicone.

[0086] The side-chain modified silicone (B1b) having one or more polyether groups in the side chain may be used alone or in combination of two or more.

[0087] The content of one or more selected from the side-chain modified silicone (B1a) having one or more epoxy groups in the side chain and the side-chain modified silicone (B1b) having one or more polyether groups in the side chain in the side-chain modified silicone (B1) is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, still more preferably 70% by mass to 100% by mass, even more preferably 80% by mass to 100% by mass, still even more preferably 90% by mass to 100% by mass, and most preferably 95% by mass to 100% by mass, based on the total amount of the side-chain modified silicone (B1).

[0088] <Epoxy compound (C)> The refrigerant oil composition of the present embodiment contains an epoxy compound (C) that satisfies the following requirements (α) and (β). (α) It has at least one divalent group represented by the following formula (2) in the molecule. [Chemical formula] (β) It has at least one ester group in the molecule.

[0089] By using the epoxy compound (C) in combination with the modified silicone compound (B), the elution of fluorine into the refrigerant oil composition due to the decomposition of the unsaturated fluorinated hydrocarbon compound (HFO) can be effectively suppressed, and the increase in the acid value of the refrigerant oil composition can be effectively suppressed. When the refrigerant oil composition does not contain the epoxy compound (C), the increase in the acid value of the refrigerant oil composition cannot be sufficiently suppressed.

[0090] When the epoxy compound (C) has a molecular weight of 300 or more, the reactivity of the epoxy group can be appropriately suppressed, the decomposition of the unsaturated fluorinated hydrocarbon compound can be suppressed, and the solubility in the base oil is improved, which is preferable. It is more preferable that the molecular weight is 320 or more, and even more preferable that the molecular weight is 350 or more. Also, from the viewpoints of solubility in the refrigerant oil and sludge formation after stability evaluation, the molecular weight of the epoxy compound (C) is preferably 2,000 or less, more preferably 1,500 or less, and even more preferably 1,000 or less.

[0091] In the refrigerant oil composition of the present embodiment, from the viewpoint of more easily improving the effects of the present invention, the content of the epoxy compound (C) is preferably 0.05% by mass or more, more preferably 0.07% by mass or more, and even more preferably 0.08% by mass or more based on the total amount of the refrigerant oil composition. The upper limit value of the content of the epoxy compound (C) is not particularly limited, but from the viewpoint of obtaining an effect commensurate with the addition amount, it is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, and even more preferably 3.0% by mass or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, preferably, it is 0.05% by mass to 5.0% by mass, more preferably 0.07% by mass to 4.0% by mass, still more preferably 0.08% by mass to 3.0% by mass.

[0092] In the present embodiment, the epoxy compound (C) can be used without particular limitation as one or more selected from the group consisting of those satisfying the above two requirements (α) and (β). Here, from the viewpoint of more easily improving the effects of the present invention, the epoxy compound (C) preferably contains one or more selected from the group consisting of epoxidized fatty acid esters (C1), epoxidized vegetable oils (C2), and epoxidized alicyclic carboxylic acid esters (C3). The content of one or more selected from the group consisting of epoxidized fatty acid esters (C1), epoxidized vegetable oils (C2), and epoxidized alicyclic carboxylic acid esters (C3) in the epoxy compound (C) is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, still more preferably 70% by mass to 100% by mass, even more preferably 80% by mass to 100% by mass, still even more preferably 90% by mass to 100% by mass, and still more preferably 95% by mass to 100% by mass, based on the total amount of the epoxy compound (C). Hereinafter, the epoxidized fatty acid ester (C1), the epoxidized vegetable oil (C2), and the epoxidized alicyclic carboxylic acid ester (C3) will be described.

[0093] (Epoxidized fatty acid ester (C1)) Examples of the epoxidized fatty acid ester (C1) include those obtained by epoxidizing an ester of a fatty acid having 8 to 30 carbon atoms (preferably 12 to 20 carbon atoms) and an alcohol, phenol, or alkylphenol having 1 to 10 carbon atoms or 7 to 14 carbon atoms.

[0094] As the epoxidized fatty acid ester (C1), those represented by the following general formula (c1) are preferably used from the viewpoint of effectively suppressing an increase in the acid value of the refrigerant oil composition. [Chemical formula] (In formula (c1), R c1 is a hydrocarbon group having 4 to 20 carbon atoms, and R c2 is a hydrocarbon group having 1 to 10 carbon atoms, p is an integer of 1 to 3, n is an integer of 0 to 12, and m is an integer of 1 to 3. When m is 2 or more, the structures within the plurality of [] may be the same or different from each other.) Examples of the above hydrocarbon group include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, various propylcyclohexyl groups, various dimethylcyclohexyl groups; aryl groups such as phenyl group, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, various naphthyl groups; arylalkyl groups such as benzyl group, various phenylethyl groups, various methylbenzyl groups, various phenylpropyl groups, various phenylbutyl groups; etc., each having the corresponding number of carbon atoms. Among the epoxidized fatty acid esters represented by the above (c1), R c1 is an alkyl group having 5 to 12 carbon atoms, R c2 is an alkyl group having 1 to 6 carbon atoms, p is 1, n is an integer of 1 to 10, and m is preferably 1 or 2.

[0095] Specific examples of the epoxidized fatty acid ester (C1) include epoxidized products of butyl ester, hexyl ester, 2-ethylhexyl ester, benzyl ester, cyclohexyl ester, methoxyethyl ester, octyl ester, phenyl ester or butylphenyl ester of linoleic acid, oleic acid, palmitic acid, linolenic acid, or stearic acid. Examples of commercially available epoxidized fatty acid esters (C1) include Sansosizer E-6000 manufactured by Shin Nippon Rika Co., Ltd., and Chemisizer T-5000 manufactured by Sanwa Chemical Co., Ltd.

[0096] The epoxidized fatty acid ester (C1) may be used alone or in combination of two or more.

[0097] (Epoxidized vegetable oil (C2)) Examples of the epoxidized vegetable oil (C2) include those obtained by epoxidizing vegetable oils such as soybean oil, linseed oil, rice bran oil, and cottonseed oil.

[0098] From the viewpoint of more easily improving the effects of the present invention, the epoxidized vegetable oil (C2) preferably has a group represented by the following general formula (c2). More specifically, a glycerin ester having one or more groups represented by the following general formula (c2) is preferred, a triglyceride having one or more groups represented by the following general formula (c2) is more preferred, and a triglyceride having two or more groups represented by the following general formula (c2) is even more preferred.

Chemical formula

[0099] Examples of commercially available epoxidized vegetable oils (C2) include Sansoizer E-2000H manufactured by Shin Nippon Rika Co., Ltd., Chemizer SE-80, Chemizer SE-100, Chemizer T-3000N, Chemizer LE-3000, Chemizer T-2000 manufactured by Sanwa Chemical Co., Ltd., New Sizer 510R manufactured by NOF Corporation, Adeka Sizer O-180A manufactured by ADEKA Corporation, and the like.

[0100] The epoxidized vegetable oil (C2) may be used alone or in combination of two or more.

[0101] (Epoxidized alicyclic carboxylic acid ester (C3)) Examples of the epoxidized alicyclic carboxylic acid ester (C3) include those obtained by epoxidizing esters of alicyclic carboxylic acids having 5 to 12 ring carbon atoms with alcohols having 1 to 8 carbon atoms, phenols, or alkylphenols having 7 to 14 carbon atoms. The above alicyclic carboxylic acid may be a monocarboxylic acid or a dicarboxylic acid.

[0102] From the viewpoint of effectively suppressing the increase in the acid value of the refrigerant oil composition, the epoxidized alicyclic carboxylic acid ester (C3) represented by the following general formula (c3) is preferably used. [Chemical formula] (In the formula (c3), R c3 and R c4 are each independently a hydrocarbon group having 4 to 20 carbon atoms.) Specific examples of the above hydrocarbon group include those having corresponding carbon numbers among those listed as the hydrocarbon group in the formula (c1). In the epoxidized alicyclic carboxylic acid ester represented by the above (c3), it is preferable that R c3 and R c4 are each independently an alkyl group having 6 to 12 carbon atoms.

[0103] Specific examples of the epoxidized alicyclic carboxylic acid ester include epoxidized alicyclic dicarboxylic acid esters, and more specifically, 4,5-epoxycyclohexane-1,2-dicarboxylic acid di-2-ethylhexyl. Commercially available products of the epoxidized alicyclic carboxylic acid ester include Sansosizer E-PS manufactured by Shin Nippon Rika Co., Ltd.

[0104] The epoxidized alicyclic carboxylic acid ester (C3) may be used alone or in combination of two or more.

[0105] Here, from the viewpoint of more easily improving the effects of the present invention, the epoxy compound (C) more preferably contains at least one selected from the group consisting of the epoxidized fatty acid ester (C1) and the epoxidized vegetable oil (C2), and further preferably contains the epoxidized fatty acid ester (C1).

[0106] <Content ratio of the modified silicone compound (B) and the epoxy compound (C)> In the refrigerant oil composition of the present embodiment, from the viewpoint of more easily improving the effects of the present invention, the content ratio [(B) / (C)] of the modified silicone compound (B) and the epoxy compound (C) is preferably 0.10 or more, more preferably 0.50 or more, still more preferably 1.0 or more, and even more preferably more than 1.0 in terms of mass ratio. Also, it is preferably 10 or less, more preferably 9.0 or less, and still more preferably 8.0 or less. The upper limit value and the lower limit value of these numerical ranges can be arbitrarily combined. Specifically, it is preferably 0.10 or more and 10 or less, more preferably 0.50 or more and 9.0 or less, still more preferably 1.0 or more and 8.0 or less, and even more preferably more than 1.0 and 8.0 or less.

[0107] <Antioxidant (D)> The refrigerant oil composition of the present embodiment may further contain an antioxidant (D). As the antioxidant (D), preferably, one or more selected from the group consisting of phenolic antioxidants and amine antioxidants are mentioned. Examples of the phenolic antioxidant include 2,6-di-tert-butyl-p-cresol (DBPC), 2,6-di-tert-butyl-4-ethylphenol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), and the like. Examples of the amine antioxidant include phenyl-α-naphthylamine, N,N'-diphenyl-p-phenylenediamine, and the like. Among these, phenolic antioxidants are preferred, and among the phenolic antioxidants, 2,6-di-tert-butyl-p-cresol (DBPC) is preferred. From the viewpoints of stability and antioxidant performance, the content of the antioxidant (D) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, still more preferably 0.1% by mass or more, based on the total amount of the refrigerant oil composition. Also, it is preferably 5% by mass or less, more preferably 3% by mass or less, still more preferably 1% by mass or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, it is preferably 0.01% by mass to 5% by mass, more preferably 0.05% by mass to 3% by mass, still more preferably 0.1% by mass to 1% by mass. The antioxidant (D) may be used alone or in combination of two or more.

[0108] (Content ratio of the modified silicone compound (B) and the antioxidant (D)) When the refrigerant oil composition of the present embodiment contains the antioxidant (D), from the viewpoint of more easily improving the effects of the present invention, the content ratio [(B) / (D)] of the modified silicone compound (B) and the antioxidant (D) is preferably 0.10 or more, more preferably 0.20 or more, still more preferably 0.30 or more, in terms of mass ratio. Also, it is preferably 5.0 or less, more preferably 3.5 or less, still more preferably 2.0 or less.

[0109] (Content ratio of epoxy compound (C) and antioxidant (D)) When the refrigerant oil composition of the present embodiment contains an antioxidant (D), from the viewpoint of making it easier to further improve the effects of the present invention, the content ratio [(C) / (D)] of the epoxy compound (C) and the antioxidant (D) is preferably 0.05 or more, more preferably 0.10 or more, still more preferably 0.20 or more, in terms of mass ratio. Also, it is preferably 5.0 or less, more preferably 2.0 or less, still more preferably 1.0 or less.

[0110] <Glycidyl ether compound (E)> The refrigerant oil composition of the present embodiment may further contain a glycidyl ether compound (E). Examples of the glycidyl ether compound (E) include glycidyl ethers derived from aliphatic mono- or polyhydric alcohols having 3 to 30 carbon atoms, preferably 4 to 24 carbon atoms, more preferably 6 to 16 carbon atoms, or aromatic compounds containing one or more hydroxyl groups. The aliphatic mono- or polyhydric alcohol may be linear, branched, or cyclic, and may be saturated or unsaturated, but is preferably a saturated aliphatic monoalcohol. In the case of aliphatic polyhydric alcohols or aromatic compounds containing two or more hydroxyl groups, from the viewpoint of the stability of the refrigerant oil composition, it is preferable that all of the hydroxyl groups are glycidyl etherified. Examples of the glycidyl ether compound include phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, etc. Among these, glycidyl ethers derived from linear, branched, or cyclic saturated aliphatic monohydric alcohols having 6 to 16 carbon atoms (i.e., alkyl glycidyl ethers having 6 to 16 carbon atoms in the alkyl group) are more preferable. Examples of such glycidyl ethers include 2-ethylhexyl glycidyl ether, isononyl glycidyl ether, decyl glycidyl ether, lauryl glycidyl ether, myristyl glycidyl ether, etc., and 2-ethylhexyl glycidyl ether is most preferable. By using an alkyl glycidyl ether such as 2-ethylhexyl glycidyl ether, an increase in the acid value of the refrigerant oil composition can be appropriately prevented, and it becomes easier to improve the oxidation stability at high temperatures.

[0111] The content of the glycidyl ether compound (E) is preferably 0.10 to 10.00% by mass based on the total amount of the refrigerant oil composition. By setting the content of the glycidyl ether compound (E) to 0.10% by mass or more, the acid in the refrigerant oil composition can be appropriately captured, and the increase in the acid value of the refrigerant oil composition can be effectively prevented, making it easier to enhance the high-temperature stability. Also, by setting it to 10.00% by mass or less, it is possible to achieve an effect commensurate with the content. Moreover, the above content of the glycidyl ether compound (E) is more preferably 0.4% by mass or more, still more preferably 0.5% by mass or more. Also, it is more preferably 5% by mass or less, still more preferably 4% by mass or less, and even more preferably 3% by mass or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, it is more preferably 0.4% by mass to 5% by mass, still more preferably 0.5% by mass to 4% by mass, and even more preferably 0.5% by mass to 3% by mass. The glycidyl ether compound (E) may be used alone or in combination of two or more.

[0112] (Content ratio of the modified silicone compound (B) and the glycidyl ether compound (E)) When the refrigerant oil composition of the present embodiment contains the glycidyl ether compound (E), from the viewpoint of more easily improving the effects of the present invention, the content ratio [(B) / (E)] of the modified silicone compound (B) and the glycidyl ether compound (E) is preferably 0.01 or more, more preferably 0.05 or more, still more preferably 0.08 or more in terms of mass ratio. Also, it is preferably 5.0 or less, more preferably 2.0 or less, still more preferably 1.0 or less.

[0113] (Content ratio of the epoxy compound (C) and the glycidyl ether compound (E)) When the refrigerant oil composition of the present embodiment contains the glycidyl ether compound (E), from the viewpoint of more easily improving the effects of the present invention, the content ratio [(C) / (E)] of the epoxy compound (C) and the glycidyl ether compound (E) is preferably 0.01 or more, more preferably 0.03 or more, still more preferably 0.04 or more in terms of mass ratio. Also, it is preferably 5.0 or less, more preferably 2.0 or less, still more preferably 1.0 or less.

[0114] <Stabilizer (F)> The refrigerant oil composition of the present embodiment may further contain a stabilizer (F). Examples of the stabilizer (F) include aliphatic unsaturated compounds and terpenes having double bonds. As the above aliphatic unsaturated compound, an unsaturated hydrocarbon is preferable, and specifically, olefins; polyenes such as dienes and trienes can be mentioned. As the olefin, from the viewpoint of reactivity with oxygen, α-olefins such as 1-tetradecene, 1-hexadecene, and 1-octadecene are preferable. As the aliphatic unsaturated compound other than the above, from the viewpoint of reactivity with oxygen, the molecular formula C 20 H 30 Unsaturated aliphatic alcohols having a conjugated double bond such as vitamin A ((2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohex-1-yl)nona-2,4,6,8-tetraen-1-ol) represented by O are preferable. As the terpenes having a double bond, terpene hydrocarbons having a double bond are preferred. From the viewpoint of reactivity with oxygen, α-pinene, β-pinene, α-farnesene (C 15 H 24 : 3,7,11-trimethyldodeca-1,3,6,10-tetraene) and β-farnesene (C 15 H 24 : 7,11-dimethyl-3-methylidenendodeca-1,6,10-triene) are more preferred.

[0115] The content of the stabilizer (F) is preferably 0.10% by mass or more, more preferably 0.20% by mass or more, and still more preferably 0.30% by mass or more based on the total amount of the refrigerant oil composition. Also, it is preferably 8.0% by mass or less, more preferably 5.0% by mass or less, and still more preferably 3.0% by mass or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, it is more preferably 0.10% by mass to 8.0% by mass, still more preferably 0.20% by mass to 5.0% by mass, and even more preferably 0.30% by mass to 3.0% by mass. The stabilizer (F) may be used alone or in combination of two or more.

[0116] (Content ratio of the modified silicone compound (B) and the stabilizer (F)) When the refrigerant oil composition of the present embodiment contains the stabilizer (F), from the viewpoint of more easily improving the effects of the present invention, the content ratio [(B) / (F)] of the modified silicone compound (B) and the stabilizer (F) is preferably 0.01 or more, more preferably 0.04 or more, and still more preferably 0.06 or more in terms of mass ratio. Also, it is preferably 5.0 or less, more preferably 3.0 or less, and still more preferably 1.0 or less.

[0117] (Content ratio of the epoxy compound (C) and the stabilizer (F)) When the refrigerant oil composition of the present embodiment contains the stabilizer (F), from the viewpoint of more easily improving the effects of the present invention, the content ratio [(C) / (F)] of the epoxy compound (C) and the stabilizer (F) is preferably 0.01 or more, more preferably 0.04 or more, still more preferably 0.06 or more in terms of mass ratio. Also, it is preferably 5.0 or less, more preferably 3.0 or less, still more preferably 1.0 or less.

[0118] <Other Additives> In addition to the modified silicone compound (B), epoxy compound (C), antioxidant (D), glycidyl ether compound (E), and stabilizer (F), the refrigerant oil composition of the present embodiment may contain other additives (hereinafter also referred to as "other additives"). Examples of other additives include extreme pressure agents and defoamers. That is, the refrigerant oil composition of the present embodiment may consist only of the base oil (A), modified silicone compound (B), and epoxy compound (C), but in addition to the base oil (A), modified silicone compound (B), and epoxy compound (C), it may further contain one or more selected from the group consisting of antioxidant (D), glycidyl ether compound (E), stabilizer (F), extreme pressure agent, and defoamer.

[0119] (Extreme Pressure Agent) As the extreme pressure agent, phosphorus-based extreme pressure agents, metal salts of carboxylic acids, and sulfur-based extreme pressure agents are preferred. Examples of phosphorus-based extreme pressure agents include phosphate esters, acidic phosphate esters, phosphite esters, acidic phosphite esters, and amine salts thereof. Among these, from the viewpoint of improving extreme pressure properties and friction characteristics, one or more selected from tricresyl phosphate (TCP), trithiophenyl phosphate, tri(nonylphenyl) phosphite, dioleyl hydrogen phosphite, and 2-ethylhexyl diphenyl phosphite are preferred, and tricresyl phosphate (TCP) is more preferred. Examples of the metal salts of carboxylic acids include metal salts of carboxylic acids having 3 to 60 carbon atoms (preferably 3 to 30 carbon atoms). Among these, one or more selected from metal salts of fatty acids having 12 to 30 carbon atoms and metal salts of dicarboxylic acids having 3 to 30 carbon atoms are preferable. Moreover, as the metal constituting the metal salt, alkali metals and alkaline earth metals are preferable, and alkali metals are more preferable. Examples of the sulfur-based extreme pressure agent include sulfurized oils and fats, sulfurized fatty acids, sulfurized esters, sulfurized olefins, dihydrocarbyl polysulfides, thiocarbamates, thioterpenes, dialkylthiodipropionates, and the like.

[0120] (Antifoaming agent) Examples of the antifoaming agent include silicone-based antifoaming agents such as silicone oil and fluorinated silicone oil. Note that the silicone compound used as the antifoaming agent is an unmodified silicone compound that is not classified as the modified silicone compound (B).

[0121] [Method for producing a refrigerant oil composition] The method for producing the above refrigerant oil composition is not particularly limited. For example, the method for producing the refrigerant oil composition of the present embodiment is represented by the following general formula (1) C x F y H z ···(1) [In the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds.] It is a method for producing a refrigerant oil composition used in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by a base oil (A) containing one or more selected from the group consisting of polyalkylene glycols, poly(oxy)alkylene glycol or a copolymer of its monoether and polyvinyl ether, and polyol esters, a modified silicone compound (B), An epoxy compound (C) satisfying the following requirements (α) and (β), is included in the step of mixing, In the above step, the modified silicone compound (B) is blended so as to exceed 0.10% by mass based on the total amount of the refrigerant oil composition. A method for producing a refrigerant oil composition. · Requirement (α): It has at least one divalent group represented by the following formula (2) in the molecule. [Chemical formula] · Requirement (β): It has at least one ester group in the molecule. As a method for mixing the above components, there is no particular limitation. For example, a method having a step of blending the modified silicone compound (B) and the epoxy compound (C) with the base oil (A) can be mentioned. The antioxidant (D), glycidyl ether compound (E), stabilizer (F), and other additives may be blended with the base oil (A) simultaneously with blending the modified silicone compound (B) and the epoxy compound (C) with the base oil (A), or may be blended separately. In addition, each component may be blended after adding a diluent oil or the like to form a solution (dispersion). After blending each component, it is preferable to stir and disperse them uniformly by a known method.

[0122] [Physical properties of refrigerant oil composition] In this embodiment, the physical property values of the refrigerant oil composition after the heat stability test described in the examples below are as follows.

[0123] [Acid value] The acid value of the refrigerant oil composition after the heat stability test described in the examples below is preferably less than 0.18 mgKOH / g, more preferably 0.17 mgKOH / g or less, and still more preferably 0.16 mgKOH / g or less.

[0124] [Fluorine content] The fluorine content in the refrigerant oil composition after the heat stability test described in the following examples is preferably less than 17 mass ppm, more preferably 15 mass ppm or less, and still more preferably 14 mass ppm or less, based on the total amount of the refrigerant oil composition.

[0125] [Refrigerant mixture composition for refrigerators] The above refrigerant oil composition is mixed with a refrigerant and used as a refrigerant mixture composition for a refrigerator. That is, the refrigerant mixture composition for a refrigerator contains the above refrigerant oil composition and a refrigerant. Hereinafter, the refrigerant will be described.

[0126] [Refrigerant] The refrigerant used in the present embodiment is a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the following general formula (1): C x F y H z ···(1) [In the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds.]]

[0127] The above general formula (1) represents the types and numbers of elements in the molecule. Specifically, it represents an unsaturated fluorinated hydrocarbon compound having 2 to 6 carbon atoms. Unsaturated fluorinated hydrocarbon compounds having 2 to 6 carbon atoms have physical and chemical properties such as boiling point, freezing point, and latent heat of vaporization required for a refrigerant. In the general formula (1), the bonding form of x carbon atoms represented by C x includes carbon-carbon single bonds and unsaturated bonds such as carbon-carbon double bonds. From the viewpoint of stability, the carbon-carbon unsaturated bond is preferably a carbon-carbon double bond. The unsaturated fluorinated hydrocarbon compound preferably has one or more unsaturated bonds such as carbon-carbon double bonds in the molecule, and the number thereof is preferably 1. That is, it is more preferable that at least one of the bonding forms of x carbon atoms represented by C x is a carbon-carbon double bond.

[0128] As the above-mentioned unsaturated fluorinated hydrocarbon compound, preferably, for example, fluorides of linear or branched chain olefins having 2 to 6 carbon atoms or cyclic olefins having 4 to 6 carbon atoms can be mentioned. Specifically, fluorides of ethylene with 1 to 3 fluorine atoms introduced, fluorides of propene with 1 to 5 fluorine atoms introduced, fluorides of butene with 1 to 7 fluorine atoms introduced, fluorides of pentene with 1 to 9 fluorine atoms introduced, fluorides of hexene with 1 to 11 fluorine atoms introduced, fluorides of cyclobutene with 1 to 5 fluorine atoms introduced, fluorides of cyclopentene with 1 to 7 fluorine atoms introduced, fluorides of cyclohexene with 1 to 9 fluorine atoms introduced, etc. can be mentioned. Among these, fluorides of propene are preferred, and propene with 3 to 5 fluorine atoms introduced is more preferred. Specifically, one or more selected from 1,3,3,3-tetrafluoropropene (R1234ze), 2,3,3,3-tetrafluoropropene (R1234yf), and 1,2,3,3-tetrafluoropropene (R1234ye) are preferred, and 2,3,3,3-tetrafluoropropene (R1234yf) is more preferred. The above-mentioned unsaturated fluorinated hydrocarbon compound may be used alone or in combination of two or more. Therefore, only one selected from 1,3,3,3-tetrafluoropropene (R1234ze), 2,3,3,3-tetrafluoropropene (R1234yf), and 1,2,3,3-tetrafluoropropene (R1234ye) may be used alone.

[0129] (Other refrigerants) In this embodiment, the refrigerant may be a mixed refrigerant containing other compounds as needed in addition to the unsaturated fluorinated hydrocarbon compound represented by the above general formula (1), and may contain, for example, a saturated fluorinated hydrocarbon compound. As the saturated fluorinated hydrocarbon compound, fluorides of alkanes having 1 to 4 carbon atoms are preferred, fluorides of alkanes having 1 to 3 carbon atoms are more preferred, and fluorides of alkanes having 1 or 2 carbon atoms (methane or ethane) are even more preferred. Examples of the fluorides of methane or ethane include trifluoromethane (R23), difluoromethane (R32), 1,1-difluoroethane (R152a), 1,1,1-trifluoroethane (R143a), 1,1,2-trifluoroethane (R143), 1,1,1,2-tetrafluoroethane (R134a), 1,1,2,2-tetrafluoroethane (R134), 1,1,1,2,2-pentafluoroethane (R125), etc. Among these, difluoromethane and 1,1,1,2,2-pentafluoroethane are preferred. These saturated fluorinated hydrocarbon compounds may be used alone or in combination of two or more.

[0130] In addition, the refrigerant may contain natural refrigerants. Examples of natural refrigerants include hydrocarbon refrigerants (HC), carbon dioxide (CO2, carbonic acid gas), and ammonia. These natural refrigerants may be used alone or in combination of two or more. As the hydrocarbon refrigerant, hydrocarbons having 1 to 8 carbon atoms are preferred, hydrocarbons having 1 to 5 carbon atoms are more preferred, and hydrocarbons having 3 to 5 carbon atoms are even more preferred. When the number of carbon atoms is 8 or less, the boiling point of the refrigerant does not become too high, which is preferable as a refrigerant. Examples of the hydrocarbon refrigerant include one or more selected from the group consisting of methane, ethane, ethylene, propane (R290), cyclopropane, propylene, n-butane, isobutane (R600a), 2-methylbutane, n-pentane, isopentane, cyclopentane isobutane, and normal hexane. These may be used alone or in combination of two or more.

[0131] (Content of unsaturated fluorinated hydrocarbon compound in the refrigerant) In this embodiment, the refrigerant contains an unsaturated fluorinated hydrocarbon compound represented by the above general formula (1). The content of the unsaturated fluorinated hydrocarbon compound represented by the above general formula (1) is preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, still more preferably 70% by mass to 100% by mass, even more preferably 80% by mass to 100% by mass, still even more preferably 90% by mass to 100% by mass, and even more preferably 100% by mass (that is, a refrigerant composed only of the unsaturated fluorinated hydrocarbon compound), based on the total amount of the refrigerant. Even in a refrigerant with a high content of the unsaturated fluorinated hydrocarbon compound as described above, the refrigerating machine oil composition of this embodiment is excellent in the effect of suppressing the increase in acid value.

[0132] (Usage amounts of the refrigerant and the refrigerating machine oil composition) In the mixed composition for a refrigerating machine of this embodiment, the usage amounts of the refrigerating machine oil composition and the refrigerant are preferably a mass ratio [(refrigerating machine oil composition) / (refrigerant)] of 1 / 99 to 90 / 10, more preferably 5 / 95 to 70 / 30. When the mass ratio of the refrigerating machine oil composition to the refrigerant is within this range, lubricity and a suitable refrigerating capacity in the refrigerating machine can be obtained.

[0133] [Uses of the refrigerating machine oil composition and the mixed composition for a refrigerating machine] The above refrigerating machine oil composition and the mixed composition for a refrigerating machine are preferably used, for example, in an air conditioner, a refrigerator, a vending machine, a showcase, a refrigeration system, a hot water supply system, or a heating system. Examples of the air conditioner include car air conditioners such as an open-type car air conditioner and an electric car air conditioner; a gas heat pump (GHP) air conditioner; and the like.

[0134] [One aspect of the present invention provided] In one aspect of the present invention, the following [1] to

[14] are provided. [1] The following general formula (1) C x F y H z ···(1) [In the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the molecule has at least one carbon-carbon unsaturated bond.], a refrigerant oil composition used in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by a base oil (A) containing one or more selected from the group consisting of polyalkylene glycols, copolymers of poly(oxy)alkylene glycol or its monoether and polyvinyl ether, and polyol esters, a modified silicone compound (B), an epoxy compound (C) satisfying the following requirements (α) and (β) and contains a refrigerant oil composition in which the content of the modified silicone compound (B) is more than 0.10% by mass based on the total amount of the refrigerant oil composition. · Requirement (α): It has at least one divalent group represented by the following formula (2) in the molecule. [Chemical formula] · Requirement (β): It has at least one ester group in the molecule. [2] The refrigerant oil composition according to [1], wherein the modified silicone compound (B) contains a side-chain modified silicone (B1) in which at least the side chain of the polysiloxane skeleton is modified. [3] The refrigerant oil composition according to [2], wherein the side-chain modified silicone (B1) contains one or more selected from the group consisting of a side-chain modified silicone (B1a) having one or more epoxy groups in the side chain and a side-chain modified silicone (B1b) having one or more polyether groups in the side chain. [4] The refrigerant oil composition according to any one of [1] to [3], wherein the content of the modified silicone compound (B) is 0.20% by mass or more based on the total amount of the refrigerant oil composition. [5] The refrigerant oil composition according to any one of [1] to [4], wherein the molecular weight of the epoxy compound (C) is 300 or more. [6] The refrigerating machine oil composition according to any one of [1] to [5], wherein the epoxy compound (C) is at least one selected from the group consisting of an epoxidized fatty acid ester (C1) and an epoxidized vegetable oil (C2). [7] The refrigerating machine oil composition according to [6], wherein the epoxidized fatty acid ester (C1) is represented by the following general formula (c1). [Chemical formula] [In formula (c1), R c1 is a hydrocarbon group having 4 to 20 carbon atoms, R c2 is a hydrocarbon group having 1 to 10 carbon atoms, p is an integer of 1 to 3, n is an integer of 0 to 12, and m is an integer of 1 to 3. When m is 2 or more, the structures within the plurality of [] may be the same as or different from each other.] [8] The refrigerating machine oil composition according to any one of [1] to [7], wherein the content of the epoxy compound (C) is 0.05% by mass or more based on the total amount of the refrigerating machine oil composition. [9] The refrigerating machine oil composition according to any one of [1] to [8], wherein the content ratio [(B) / (C)] of the modified silicone compound (B) and the epoxy compound (C) is 0.10 or more by mass ratio.

[10] The refrigerating machine oil composition according to any one of [1] to [9], further containing at least one additive selected from the group consisting of an antioxidant (D), a glycidyl ether compound (E), a stabilizer (F), an extreme pressure agent, and an antifoaming agent.

[11] The refrigerating machine oil composition according to any one of [1] to

[10] , wherein the unsaturated fluorinated hydrocarbon compound contains at least one selected from the group consisting of R1234ze, R1234yf, and R1234ye.

[12] The refrigerating machine oil composition according to any one of [1] to

[11] , wherein the refrigerant consists only of the unsaturated fluorinated hydrocarbon compound.

[13] The following general formula (1) C x F y H z ···(1) [In the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the molecule has at least one carbon-carbon unsaturated bond.] A refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by the formula, and the refrigerant oil composition according to any one of [1] to

[12] . A refrigerant machine use mixed composition.

[14] The following general formula (1) C x F y H z ···(1) [In the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the molecule has at least one carbon-carbon unsaturated bond.] A method for producing a refrigerant oil composition used in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by the formula, A base oil (A) containing at least one selected from the group consisting of polyalkylene glycols, poly(oxy)alkylene glycols or monoethers thereof and copolymers of polyvinyl ethers, and polyol esters, A modified silicone compound (B), An epoxy compound (C) satisfying the following requirements (α) and (β), including the step of mixing, In the step, the modified silicone compound (B) is blended so as to exceed 0.10% by mass based on the total amount of the refrigerant oil composition. A method for producing a refrigerant oil composition. ·Requirement (α): It has at least one divalent group represented by the following formula (2) in the molecule.

Chemical formula

Examples

[0135] The present invention will be specifically described by the following examples. However, the present invention is not limited to the following examples.

[0136] [Measurement methods for various physical property values] The measurements of each raw material used in each example and each comparative example, and each property of the refrigerant oil compositions of each example and each comparative example were carried out according to the following procedures. (1) Kinematic viscosity at 100 °C The kinematic viscosity at 100 °C of base oil (A) was measured in accordance with JIS K2283:2000. (2) Hydroxyl value The hydroxyl value of base oil (A) was measured by the neutralization titration method in accordance with JIS K0070:1992. (3) Number average molecular weight (Mn) The number average molecular weight (Mn) of base oil (A) was measured using a gel permeation chromatography (GPC) apparatus. For GPC, two columns of "TSKgel SuperMultipore HZ-M" manufactured by Tosoh Corporation were sequentially connected and used. Tetrahydrofuran was used as the eluent, and measurement was carried out using a refractive index detector (RI detector) as the detector. The number average molecular weight (Mn) was determined using polystyrene as the standard sample.

[0137] [Details of each component used in the preparation of the refrigerant oil composition] Details of each component used in the preparation of the refrigerant oil composition are shown below.

[0138] <Base oil (A)> (PAG) "Polyoxypropylene glycol dimethyl ether": kinematic viscosity at 100 °C = 10.3 mm 2 / s, hydroxyl value = 1 mg KOH / g, number average molecular weight = 1,020 (ECP) "Copolymer of polypropylene glycol (PPG) and polyethyl vinyl ether (PEV) (PPG / PEV = 5 / 5 (molar ratio))": kinematic viscosity at 100 °C = 10.5 mm 2 / s, hydroxyl value = 1 mg KOH / g, number average molecular weight = 870 (POE) "Ester of pentaerythritol and a mixture of octanoic acid (C8 acid) and nonanoic acid (C9 acid) (C8 acid / C9 acid = 1 / 1.1 (molar ratio))": kinematic viscosity at 100 °C = 8.5 mm 2 / s, acid value = 1 mg KOH / g, number average molecular weight = 670

[0139] <Modified silicone compound (B)> · "Epoxy-modified silicone": KF-101 (manufactured by Shin-Etsu Chemical Co., Ltd.) Epoxy-modified silicone is a modified silicone corresponding to side-chain modified silicone (B1a) having one or more epoxy groups in the side chain. · "Polyether-modified silicone": KF-945 (manufactured by Shin-Etsu Chemical Co., Ltd.), HLB value = 4 Polyether-modified silicone is a modified silicone corresponding to side-chain modified silicone (B1b) having one or more polyether groups in the side chain.

[0140] <Epoxy compound (C)> · "Epoxy compound 1": Epoxidized soybean oil represented by the following formula, molecular weight: 933, Sansoizer E-2000H (manufactured by Shin Nippon Rika Co., Ltd.)

Chemical formula

Chemical formula

[0141] <Antioxidant (D)> Di-tert-butyl-p-cresol (DBPC)

[0142] <Glycidyl ether compound (E)> 2-Ethylhexyl glycidyl ether

[0143] <Stabilizer (F)> β-Pinene

[0144] <Other additives> Extreme pressure agent (tricresyl phosphate), silicone-based defoaming agent ※ The silicone-based defoaming agent is an unmodified silicone compound that is not classified as the modified silicone compound (B).

[0145] [Examples, Comparative Examples] The above components were mixed to prepare refrigerant oil compositions having the compositions shown in Tables 1 to 3, and the thermal stability test described below was conducted. Note that the numerical unit of the compounding composition in Tables 1 to 3 is "mass%". Also, the content of the modified silicone compound (B) in Tables 1 to 3 means the content in terms of solid content.

[0146] <Thermal stability test> It was carried out in accordance with Appendix C of JIS K2211:2009. Specifically, a refrigerant mixture composition (water content 500 mass ppm, air content 25 mL) obtained by mixing 30 g of the refrigerant oil compositions of the examples and comparative examples and 30 g of R1234yf, and a metal catalyst composed of iron, copper, and aluminum were sealed in an autoclave tube with an internal volume of 200 mL. Next, after evacuation, the tube was sealed and held at a temperature of 175 °C for 14 days, and then the appearance of the oil and the presence or absence of precipitates (and the color if there were precipitates) were visually observed. Note that the appearance of the oil was evaluated by ASTM color, and those judged to be 0.5 or less (L0.5) were judged to have good oil appearance, and those judged to be greater than 0.5 (L1.0, L1.5, etc.) were judged to have poor oil appearance. Also, after the thermal stability test, the acid value of the refrigerant oil composition and the amount of fluorine in the refrigerant oil composition were evaluated by the method described below.

[0147] (Evaluation of acid value of refrigerant oil composition) It was measured by the indicator photometric titration method (see Appendix 1 in the above JIS standard) in accordance with JIS K2501:2003.

[0148] (Evaluation of the amount of fluorine in the refrigerant oil composition) The amount of fluorine in the refrigerant oil composition was determined by separating the refrigerant from the mixed composition for the refrigerator after the autoclave test and detecting and measuring the fluoride ions (F - ) in the refrigerant oil composition in accordance with JIS K 0127:2013 (General Rules for Ion Chromatographic Analysis).

[0149] [Table 1] [Table 2] [Table 3]

[0150] From Table 1, the following can be understood. It can be seen that the refrigerant oil compositions of Examples I-1 to I-4 are excellent in the effect of suppressing the increase in the acid value of the refrigerant oil composition after the thermal stability test, and the amount of fluorine in the refrigerant oil composition after the test is also small. On the other hand, it can be seen that the refrigerant oil compositions of Comparative Examples I-1 to I-10 are insufficient in the effect of suppressing the increase in the acid value of the refrigerant oil composition after the thermal stability test, and the amount of fluorine in the refrigerant oil composition after the test is also large.

[0151] From Table 2, the following can be understood. It can be seen that the refrigerant oil composition of Example II-1 is excellent in the effect of suppressing the increase in the acid value of the refrigerant oil composition after the thermal stability test, and the amount of fluorine in the refrigerant oil composition after the test is also small. On the other hand, it can be seen that the refrigerant oil compositions of Comparative Examples II-1 to II-4 are insufficient in the effect of suppressing the increase in the acid value of the refrigerant oil composition after the thermal stability test, and the amount of fluorine in the refrigerant oil composition after the test is also large.

[0152] From Table 3, the following can be understood. It can be seen that the refrigerant oil composition of Example III-1 is excellent in the effect of suppressing the increase in the acid value of the refrigerant oil composition after the thermal stability test. On the other hand, it can be seen that the refrigerant oil compositions of Comparative Examples III-1 to III-4 are insufficient in the effect of suppressing the increase in the acid value of the refrigerant oil composition after the thermal stability test. In Example III-1 and Comparative Examples III-1 to III-2, the amount of fluorine in the refrigerant oil composition after the test was small. The reason for this is considered to be that in Example III-1 and Comparative Examples III-1 to III-2, since iron and copper used as metal catalysts were slightly discolored, fluorine adhered to the iron and copper used as metal catalysts, resulting in a decrease in the amount of fluorine eluted into the refrigerant oil composition after the test. In other Examples and Comparative Examples, no discoloration of the metal catalyst was observed.

[0153] From the above results, it can be seen that the refrigerant oil composition containing the modified silicone compound (B) and the epoxy compound (C) and having the content of the modified silicone compound (B) adjusted to more than 0.10% by mass is excellent in the effect of suppressing the increase in the acid value of the refrigerant oil composition after the thermal stability test.

Claims

1. The following general formula (1) C ｘ F ｙ H ｚ ... (1) [In the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds.] A refrigerant oil composition used in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by the formula, A base oil (A) containing one or more selected from the group consisting of polyalkylene glycols, copolymers of poly(oxy)alkylene glycol or its monoether and polyvinyl ether, and polyol esters, A modified silicone compound (B), And an epoxy compound (C) satisfying the following requirements (α) and (β) Containing, The content of the modified silicone compound (B) is more than 0.10% by mass based on the total amount of the refrigerant oil composition. Refrigerant oil composition. - Requirement (α): It has at least one divalent group represented by the following formula (2) in the molecule. 【Chemical 1】 - Requirement (β): It has at least one ester group in the molecule.

2. The refrigerant oil composition according to claim 1, wherein the modified silicone compound (B) contains a side-chain modified silicone (B1) in which at least the side chains of the polysiloxane skeleton are modified.

3. The refrigerant oil composition according to claim 2, wherein the side-chain modified silicone (B1) contains one or more selected from the group consisting of a side-chain modified silicone (B1a) having one or more epoxy groups in the side chain and a side-chain modified silicone (B1b) having one or more polyether groups in the side chain.

4. The refrigerant oil composition according to any one of claims 1 to 3, wherein the content of the modified silicone compound (B) is 0.20% by mass or more based on the total amount of the refrigerant oil composition.

5. The refrigerant oil composition according to any one of claims 1 to 4, wherein the molecular weight of the epoxy compound (C) is 300 or more.

6. The refrigerant oil composition according to any one of claims 1 to 5, wherein the epoxy compound (C) is one or more selected from the group consisting of an epoxidized fatty acid ester (C1) and an epoxidized vegetable oil (C2).

7. The refrigerant oil composition according to claim 6, wherein the epoxidized fatty acid ester (C1) is represented by the following general formula (c1). [Chemical Formula 2] [In formula (c1), R ｃ１ is a hydrocarbon group having 4 to 20 carbon atoms, R ｃ２ is a hydrocarbon group having 1 to 10 carbon atoms, p is an integer of 1 to 3, n is an integer of 0 to 12, and m is an integer of 1 to 3. When m is 2 or more, the structures within the plurality of [] may be the same as or different from each other.]

8. The refrigerant oil composition according to any one of claims 1 to 7, wherein the content of the epoxy compound (C) is 0.05% by mass or more based on the total amount of the refrigerant oil composition.

9. The refrigerating machine oil composition according to any one of claims 1 to 8, wherein the content ratio [(B) / (C)] of the modified silicone compound (B) and the epoxy compound (C) is 0.10 or more by mass ratio.

10. The refrigerating machine oil composition according to any one of claims 1 to 9, further containing at least one additive selected from the group consisting of an antioxidant (D), a glycidyl ether compound (E), a stabilizer (F), an extreme pressure agent, and an antifoaming agent.

11. The refrigerating machine oil composition according to any one of claims 1 to 10, wherein the unsaturated fluorinated hydrocarbon compound contains at least one selected from the group consisting of R1234ze, R1234yf, and R1234ye.

12. The refrigerating machine oil composition according to any one of claims 1 to 11, wherein the refrigerant consists only of the unsaturated fluorinated hydrocarbon compound.

13. The following general formula (1) C ｘ F ｙ H ｚ ...(1) [In the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the molecule has at least one carbon-carbon unsaturated bond.] A refrigerating machine use mixed composition containing a refrigerant containing at least one unsaturated fluorinated hydrocarbon compound selected from the compounds represented by the formula, and the refrigerating machine oil composition according to any one of claims 1 to 12.

14. The following general formula (1) C ｘ F ｙ H ｚ ...(1) [In the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the molecule has at least one carbon-carbon unsaturated bond.] A method for producing a refrigerating machine oil composition used for a refrigerant containing at least one unsaturated fluorinated hydrocarbon compound selected from the compounds represented by the formula, A base oil (A) containing at least one selected from the group consisting of polyalkylene glycols, copolymers of poly(oxy)alkylene glycol or its monoether and polyvinyl ether, and polyol esters, A modified silicone compound (B), An epoxy compound (C) satisfying the following requirements (α) and (β), Including the step of mixing, In the step, the modified silicone compound (B) is blended so as to exceed 0.10% by mass based on the total amount of the refrigerating machine oil composition. A method for producing a refrigerating machine oil composition. ・Requirement (α): It has at least one divalent group represented by the following formula (2) in the molecule. [Chemical Formula 3] ・Requirement (β): It has at least one ester group in the molecule.

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