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 a proportion of an unsaturated fluorocarbon compound (HFO) in a refrigerant is increased.SOLUTION: A refrigerating machine oil composition that is used as a refrigerant containing one or more unsaturated fluorohydrocarbon compounds selected from compounds represented by the general formula (1) of CxFyHz comprises: a base oil (A) selected from a group consisting of polyalkylene glycols, polyvinyl ethers, poly(oxy)alkylene glycols or copolymers of mono-ether and polyvinyl ether thereof, and polyol esters; and an epoxy compound (B) that satisfies following requirements (B1), (B2) (in the 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 one or more compounds represented by the formula (1) have one or more carbon-carbon unsaturated bonds in a molecule). Requirement (B1): at least one divalent group shown in Figure (1) is included in a molecule. Requirement (B2): at least one ester group is included in a molecule.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a refrigeration 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 "refrigeration 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 the conventionally widely used hydrochlorofluorocarbon (HCFC), a fluorinated hydrocarbon compound with a low environmental impact is being used. As the fluorinated hydrocarbon compound, saturated fluorinated hydrocarbon 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 fluorinated hydrocarbon 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 refrigeration oil composition tends to rise.

[0006] In recent years, refrigerators have become more compact and have higher performance, and their operating conditions have become more severe than before. Therefore, the refrigeration oil composition is required to have a higher quality than ever. For example, as the refrigerator becomes more compact, the amount of the refrigeration oil composition used in the device decreases, while due to frictional heat and the like in the sliding part of the compressor due to the severer operating conditions, locations where the temperature locally becomes high are likely to occur. When the refrigeration oil composition is exposed to such locations, the acid value of the refrigeration 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 refrigeration 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 refrigeration oil composition that can effectively suppress an increase in acid value even when the content of unsaturated fluorinated hydrocarbon compounds (HFOs) in the refrigerant is increased, and a refrigeration machine use mixed composition containing the refrigeration oil composition.

Means for Solving the Problems

[0009] The present inventors conducted intensive studies to solve the above problems. As a result, they found that a refrigeration oil composition containing a specific epoxy compound can solve the above problems, and thus completed the present invention.

[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 from 2 to 6, y is an integer from 1 to 11, z is an integer from 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, It contains a base oil (A) selected from the group consisting of polyalkylene glycols, polyvinyl ethers, poly(oxy)alkylene glycol or a copolymer of the poly(oxy)alkylene glycol and its monoether with polyvinyl ether, and polyol esters, and an epoxy compound (B). The refrigerant oil composition in which the epoxy compound (B) satisfies the following requirements (B1) and (B2). (B1) It has at least one divalent group represented by the following formula (1) in the molecule. [Chemical formula] (B2) It has at least one ester group in the molecule. [2] 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 at least one carbon-carbon unsaturated bond.] A refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by, and the refrigerant oil composition according to [1]. A refrigerant mixture composition for a refrigerator. [3] 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 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, A step of mixing a base oil (A) selected from the group consisting of polyalkylene glycols, polyvinyl ethers, poly(oxy)alkylene glycols or copolymers thereof with polyvinyl ethers, and polyol esters, and an epoxy compound (B). A method for producing a refrigerating machine oil composition, wherein the epoxy compound (B) satisfies the following requirements (B1) and (B2). (B1) It has at least one divalent group represented by the following formula (1) in the molecule. [Chemical formula] (B2) It has at least one ester group in the molecule. [Advantages of the Invention]

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

[0012] The upper and lower limit values of the numerical ranges 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. Also, 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 unless otherwise specified. Also, 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] [Aspects of Refrigerating Machine Oil Composition] The refrigerating machine oil composition of the present embodiment has the following general formula (1) C x F y H z ···(1) [In the above 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 the molecule has one or more carbon-carbon unsaturated bonds.] The refrigerating machine oil composition of the present embodiment contains a base oil (A) and an epoxy compound (B). The epoxy compound (B) satisfies the following requirements (B1) and (B2). (B1) has at least one divalent group represented by the following formula (1) in the molecule. [ka] (B2) has at least one ester group in the molecule.

[0014] The present inventors conducted extensive research based on the idea that one of the factors that causes the acid value of a refrigerating machine oil composition to easily increase when the content of unsaturated fluorohydrocarbon compounds (HFOs) in a refrigerant increases is fluorine content generated by decomposition of unsaturated fluorohydrocarbon compounds (HFOs) in a high-temperature environment. As a result, the inventors have found that a refrigerating machine oil composition containing an epoxy compound (B) that satisfies specific requirements can suppress an increase in the fluorine concentration in the refrigerating machine oil composition that is caused by fluorine content generated by decomposition of unsaturated fluorohydrocarbon compounds (HFOs) in a high-temperature environment, and can suppress an increase in the acid value of the refrigerating machine oil composition.

[0015] The mechanism by which the effects of the present invention are achieved is believed to be as follows. That is, compared with an epoxy compound having a structure with an epoxy group at the molecular end, the epoxy compound (B) having an epoxy group inside the molecule is less likely to decompose an unsaturated fluorocarbon compound (HFO). Therefore, particularly in a high-temperature environment, it is less likely to generate fluorine components (e.g., hydrofluoric acid, etc.) that are generated by the decomposition of an unsaturated fluorocarbon compound (HFO), and even if a small amount of fluorine components are generated, they react with the epoxy groups in the epoxy compound (B) and are captured in the epoxy compound (B). That is, by using the epoxy compound (B), it is difficult to decompose HFO. As a result, the elution of fluorine components into the refrigerant oil composition is suppressed, and the eluted fluorine components can be captured. Therefore, it is presumed that an increase in the acid value of the refrigerant oil composition can be suppressed.

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

[0017] The refrigerant oil composition of the present embodiment may be composed only of component (A) and component (B), but may contain other components other than component (A) and component (B) as long as the effects of the present invention are not impaired. In the refrigerant oil composition of the present embodiment, the total content of component (A) and component (B) is preferably 80% by mass to 100% by mass, more preferably 85% by mass to 100% by mass, still more preferably 90% by mass to 100% by mass, based on the total amount (100% by mass) 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 the present embodiment contains a base oil (A). In the refrigerant oil composition of the present embodiment, the content of the base oil (A) is preferably 85.0% by mass or more, more preferably 90.0% by mass or more, still more preferably 92.0% by mass or more, based on the total amount (100% by mass) of the refrigerant oil composition, from the viewpoint of long-term stability required for the refrigerant oil composition. Also, from the viewpoint of easily ensuring the content of the epoxy compound (B) in the refrigerant oil composition, and further from the viewpoint of easily ensuring the content of additives other than the epoxy compound (B), it is preferably 99.0% by mass or less, more preferably 98.5% by mass or less, still more preferably 98.0% by mass or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, 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] As the base oil (A), the base oils usually used in the refrigerant oil composition can be used without particular limitation. For example, as the base oil (A), one or more selected from the group consisting of synthetic oils and mineral oils can be used. Here, in the refrigerant oil composition of the present embodiment, from the viewpoint of the solubility of the epoxy compound (B), the base oil (A) is preferably a synthetic oil. Among synthetic oils, from the viewpoint of improving the thermal stability of the refrigerant oil composition, the base oil (A) preferably contains one or more base oils (hereinafter also referred to as "base oil (A1)") selected from the group consisting of polyalkylene glycols (hereinafter also referred to as "PAG"), polyvinyl ethers (hereinafter also referred to as "PVE"), poly(oxy)alkylene glycol or a copolymer of its monoether and polyvinyl ether (hereinafter also referred to as "ECP"), and polyol esters (hereinafter also referred to as "POE"). Furthermore, from the viewpoints of improving the compatibility with the refrigerant, improving the hydrolysis resistance, and further improving the thermal stability of the refrigerant oil composition, the base oil (A) more preferably contains one or more base oils (hereinafter also referred to as "base oil (A2)") selected from the group consisting of PAG and PVE. Hereinafter, PAG, PVE, 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 ) p -OR 15a ) q (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 kinds.

[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] q is an integer of 1 to 6, preferably an integer of 1 to 3, more preferably 1. Note that q 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, q 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, q is 2, 3, 4, 5, or 6, respectively. p is the number of repeating units of OR 14a and is usually 1 or more, preferably a number such that p×q is 6 to 80. Note that the value of p is a value appropriately set to adjust the kinematic viscosity at 40 °C of the base oil (A), and is not particularly limited as long as the kinematic viscosity at 40 °C is adjusted to an appropriate range. Note that a plurality of R14a may be the same or different from each other. When q is 2 or more, a plurality of Rs in one molecule 15a may be the same or different from each other.

[0024] R 13a and R 15a Examples of the monovalent hydrocarbon group represented by include 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 and other alkyl groups; cyclopentyl group, cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, various propylcyclohexyl groups, various dimethylcyclohexyl groups and other cycloalkyl groups; phenyl group, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, various naphthyl groups and other aryl groups; benzyl group, various phenylethyl groups, various methylbenzyl groups, various phenylpropyl groups, various phenylbutyl groups and other arylalkyl groups; etc. The 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". In addition, for a group having a cyclic structure, it means including positional isomers such as ortho-isomer, meta-isomer, para-isomer, etc., and the same applies hereinafter. R 13a and R 15a The carbon number 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-mentioned R 13a and R 15aExamples 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 of 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 residues obtained by further removing 1 to 5 hydrogen atoms from the monovalent hydrocarbon group represented by the above-mentioned R 13a residues obtained by removing hydroxyl groups from polyhydric alcohols such as trimethylolpropane, glycerin, pentaerythritol, sorbitol, 1,2,3-trihydroxycyclohexane, and 1,3,5-trihydroxycyclohexane, and the like. R 13a From the viewpoint of compatibility with the refrigerant, the number of carbon atoms of 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, and hexamethylene oxide; residues obtained by removing 1 to 6 hydrogen atoms from oxygen atom-containing unsaturated heterocycles such as acetylene oxide, furan, pyran, oxycycloheptatriene, isobenzofuran, and isochromene, and the like. 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, and hexamethylene sulfide; residues obtained by removing 1 to 6 hydrogen atoms from sulfur atom-containing unsaturated heterocycles such as acetylene sulfide, thiophene, thiapyran, and thiotripyridine, and the like.

[0028] R 13a and R15a The above-mentioned complex ring group represented by the formula may have a substituent, and the substituent may be bonded to the oxygen atom in the above general formula (A-1). As the substituent, as described above, 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 complex ring 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-), etc. 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-), etc. alkylene groups having 4 carbon atoms. Among these, as 14a R, a propylene group (-CH(CH3)CH2-) is preferable.

[0030] In the polymer (A-1) represented by the above general formula (A-1), the content of oxypropylene units (-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 preferable.

[0032]

Chemical formula

[0033]

Chemical formula

[0034]

Chemical formula

[0035]

Chemical formula

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

[0037] (Polyvinyl ethers (PVE)) PVE is a polymer having one or more structural units derived from vinyl ether, and in the refrigerant oil composition, PVE used as the base oil can be used without particular limitation. In addition, when PVE is contained in the base oil (A), PVE may be used alone or in combination of two or more. From the viewpoint of compatibility with the refrigerant, PVE is preferably a polymer having one or more structural units derived from vinyl ether and having an alkyl group having 1 to 4 carbon atoms in the side chain. As the alkyl group, from the viewpoint of further improving the compatibility with the refrigerant, a methyl group or an ethyl group is preferable, and a methyl group is more preferable.

[0038] PVE is preferably a polymer (A-2) having one or more structural units represented by the following general formula (A-2).

[0039] [Chemical formula]

[0040] In the formula (A-2), R 1a , R 2a , and R 3a each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. R 4a represents a divalent hydrocarbon group having 2 to 10 carbon atoms. R 5a represents a hydrocarbon group having 1 to 10 carbon atoms. r is the number of repeating units of OR 4a , and is usually 0 to 10, preferably 0 to 5, more preferably 0 to 3, and still more preferably 0. When there are a plurality of OR 4a in the structural unit represented by the general formula (A-2), the plurality of OR 4amay be the same or different from each other.

[0041] R 1a , R 2a and R 3a Examples of the hydrocarbon group having 1 to 8 carbon atoms represented by the formula (I) include alkyl groups such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, and various octyl groups; cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, and various dimethylcyclohexyl groups; aryl groups such as a phenyl group, various methylphenyl groups, various ethylphenyl groups, and various dimethylphenyl groups; and arylalkyl groups such as a benzyl group, various phenylethyl groups, and various methylbenzyl groups.

[0042] R 1a , R 2a , and R 3a The hydrocarbon group represented by the following formula (1) preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms. R 1a , R 2a , and R 3a are each 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 3 carbon atoms, and further preferably a hydrogen atom.

[0043] R 4aExamples of the divalent hydrocarbon group having 2 to 10 carbon atoms represented by include divalent aliphatic groups such as ethylene group, 1,2-propylene group, 1,3-propylene group, various butylene groups, various pentylene groups, various hexylene groups, various heptylene groups, various octylene groups, various nonylene groups, various decylene groups; divalent alicyclic groups such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, propylcyclohexane; divalent aromatic groups such as various phenylene groups, various methylphenylene groups, various ethylphenylene groups, various dimethylphenylene groups, various naphthylene; divalent alkylaromatic groups having a monovalent bonding site in each of the alkyl group part and the aromatic part of alkylaromatic hydrocarbons such as toluene, xylene, ethylbenzene; divalent alkylaromatic groups having a bonding site in the alkyl group part of polyalkylaromatic hydrocarbons such as xylene, diethylbenzene; and the like. R 4a The carbon number of the hydrocarbon group represented by is preferably 2 to 6, more preferably 2 to 4. R 4a is preferably a divalent aliphatic group having 2 to 10 carbon atoms, more preferably a divalent aliphatic group having 2 to 4 carbon atoms.

[0044] R 5a Examples of the hydrocarbon group having 1 to 10 carbon atoms 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, 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; and the like. R 5a The carbon number of the hydrocarbon group represented by is preferably 1 to 8, more preferably 1 to 6. R 5a From the viewpoint of further improving the compatibility with the refrigerant, an alkyl group having 1 to 6 carbon atoms is preferable, an alkyl group having 1 to 4 carbon atoms is more preferable, a methyl group or an ethyl group is still more preferable, and a methyl group is even more preferable.

[0045] The number of units (degree of polymerization) of the structural unit represented by the above general formula (A-2) is appropriately selected according to the kinematic viscosity required for the base oil (A). In addition, the polymer having the structural unit represented by the general formula (A-2) may be a homopolymer having only one kind of the structural unit, or may be a copolymer having two or more kinds of the structural unit. When the polymer is a copolymer, the form of copolymerization is not particularly limited, and it may be any of a block copolymer, a random copolymer, or a graft copolymer.

[0046] A monovalent group derived from a saturated hydrocarbon, ether, alcohol, ketone, amide, nitrile, etc. may be introduced into the terminal portion of the polymer (A-2). Among these, it is preferable that one terminal portion of the polymer (A-2) is a group represented by the following general formula (A-2-i).

[0047]

Chemical formula

[0048] In formula (A-2-i), * indicates the bonding position with the carbon atom in the structural unit represented by the above general formula (A-2). In formula (A-2-i), R 6a , R 7a , and R 8a each independently represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. R 6a , R 7a , and R 8a As the hydrocarbon group having 1 to 8 carbon atoms represented by, in the R in the above general formula (A-2) 1a , R 2a , and R3a The same ones as those listed as the hydrocarbon groups having 1 to 8 carbon atoms represented by

[0049] In the above formula (A-2-i), R 9a represents a divalent hydrocarbon group having 2 to 10 carbon atoms, preferably a divalent hydrocarbon group having 2 to 6 carbon atoms, and more preferably a divalent aliphatic group having 2 to 4 carbon atoms. In the above formula (A-2-i), r1 is the number of repeating units of OR 9a , and is usually 0 to 10, preferably 0 to 5, more preferably 0 to 3, and still more preferably 0. In addition, when there are a plurality of OR 9a in the structural unit represented by the above general formula (A-2-i), the plurality of OR 9a may be the same or different from each other. R 9a The divalent hydrocarbon group having 2 to 10 carbon atoms represented by is the same as those listed as the divalent hydrocarbon group having 2 to 10 carbon atoms represented by R in the above general formula (A-2). 4a

[0050] In formula (A-2-i), R 10a represents a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrocarbon group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 8 carbon atoms. In addition, as R 10a , when r1 in the above general formula (A-2-i) is 0, an alkyl group having 1 to 6 carbon atoms is preferable, and when r1 is 1 or more, an alkyl group having 1 to 4 carbon atoms is preferable. R 10a The hydrocarbon group having 1 to 10 carbon atoms represented by is the same as those listed as the hydrocarbon group having 1 to 10 carbon atoms represented by R in the above general formula (A-2). 5a

[0051] ​​Further, for the polymer (A-2), when one terminal portion is a group represented by the above general formula (A-2-i), the other terminal portion is preferably any one of a group represented by the above general formula (A-2-i), a group represented by the following general formula (A-2-ii), a group represented by the following general formula (A-2-iii), and a group having an olefinic unsaturated bond.

[0052]

Chemical formula

[0053] In formulas (A-2-ii) and (A-2-iii), R 6a , R 7a , R 8a , R 9a , R 10a , and r1 are the same as defined in the above general formula (A-2-i). Further, in formula (A-2-ii), R 11a , R 12a , and r2 are the same as the definitions of R 9a , R 10a and r1 in the above general formula (A-2-i), respectively.

[0054] (Copolymer (ECP) of poly(oxy)alkylene glycol or its monoether and polyvinyl ether) The copolymer (ECP) of poly(oxy)alkylene glycol or its monoether and polyvinyl ether may be any copolymer having a structural unit derived from poly(oxy)alkylene glycol or its monoether and a structural unit derived from polyvinyl ether. 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.

[0055] [Chemical]

[0056] In 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 6c each 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 when there are a plurality of R 1c , R 2c , R 3c , R 4c , R 5c , and R 6c , 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.

[0057] In general formulas (A-3-i) and (A-3-ii), v is the average value of the number of units represented by OR 5c , indicating a number of 1 or more, preferably a number from 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 general formula (A-3-i), u represents a number of 0 or more, preferably a number from 0 to 50, and w represents a number of 1 or more, preferably a number from 1 to 50. In general formula (A-3-ii), x and y each independently represent a number of 1 or more, preferably a number from 1 to 50. The values of v, u, w, x, and y only need to be adjusted according to the hydroxyl value required for base oil (A), and there are no particular restrictions.

[0058] There are no particular restrictions on the copolymerization form of copolymer (A-3-i) and copolymer (A-3-ii), and it may be a block copolymer, a random copolymer, or a graft copolymer.

[0059] R 1c 、R 2c 、and R 3c Examples of the hydrocarbon group having 1 to 8 carbon atoms that can be selected as R in general formula (A-1) include the same ones as the monovalent hydrocarbon groups having 1 to 8 carbon atoms that can be selected as R 1a 、R 2a 、and R 3a 。 R 1c 、R 2c 、and R 3c 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 even more preferably 1 to 3. R 1c 、R 2c 、and R 3c Each independently is 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 even 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.

[0060] R4c Examples of the hydrocarbon group having 1 to 10 carbon atoms that can be selected as R in the general formula (A-2) include 5a the same as those of the hydrocarbon group having 1 to 10 carbon atoms that can be selected as R. 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.

[0061] R 5c Examples of the alkylene group that can be selected as R in the general formula (A-1) include 14a the same as those of the alkylene group having 2 or more and 4 or less carbon atoms that can be selected as R, and preferably a propylene group (-CH(CH3)CH2-). In the copolymer (A-3-i) or copolymer (A-3-ii), the content of oxypropylene units (-OCH(CH3)CH2-) is based on the total amount (100 mol%) of oxyalkylene (OR 5c ) that is a structural unit derived from poly(oxy)alkylene glycol or its monoether in the copolymer (A-3-i) or copolymer (A-3-ii), and is 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.

[0062] 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, etc. 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.

[0063] R 6c Examples of the alicyclic group having 3 to 20 ring-forming carbon atoms 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, etc. The number of carbon atoms forming the ring of the alicyclic group is preferably 3 to 10, more preferably 3 to 8, still more preferably 3 to 6. The alicyclic group may have the aforementioned substituents, and as the substituents, an alkyl group is preferred.

[0064] R 6c Examples of the aromatic group having 6 to 24 carbon atoms forming the ring that can be selected as R include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthryl group, etc. The number of carbon atoms forming the ring of the aromatic group is preferably 6 to 18, more preferably 6 to 12. The aromatic group may have the aforementioned substituents, and as the substituents, an alkyl group is preferred.

[0065] R 6c Examples of the acyl group having 2 to 20 carbon atoms forming the ring 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, etc. The number of carbon atoms of the acyl group is preferably 2 to 10, preferably 2 to 8, still more preferably 2 to 6.

[0066] 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, etc. The number of carbon atoms of the carbon-containing hydrocarbon group is preferably 2 to 20, more preferably 2 to 10, still more preferably 2 to 6.

[0067] 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.

[0068] (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.

[0069] 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.

[0070] 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), and the like. 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.

[0071] 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.

[0072] Examples of the fatty acid 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 preferable.

[0073] As the POE, it may be a partial ester in which some of the plurality of hydroxyl groups possessed by the polyol remain unesterified, or a complete ester in which all the hydroxyl groups are esterified. Further, the POE may be a mixture of a partial ester and a complete ester, but a complete ester is preferable.

[0074] 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) etc. are preferable as the POE, esters of neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol are more preferable, and from the viewpoint of particularly excellent compatibility with the refrigerant and hydrolysis stability, esters of pentaerythritol are even more preferable.

[0075] 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.

[0076] Note that the ester with two or more fatty acids may be a mixture of two or more esters of one fatty acid and a polyol. 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.

[0077] (Preferred embodiments of base oil (A)) In the refrigerant oil composition of the present embodiment, from the viewpoint of long-term stability required for the refrigerant oil composition, the above base oil (A1) is preferable as the main component of the base oil (A), and the above base oil (A2) is more preferable. In addition, the "main component" in this specification means the component with the highest content rate. The content of the base oil (A1) or the base oil (A2) 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 more preferably 90% by mass to 100% by mass, and even more preferably 100% by mass, based on the total amount (100% by mass) of the base oil (A).

[0078] Here, it is preferable that the base oil (A1) is PAG, PVE, ECP, or POE (that is, it consists only of PAG, PVE, ECP, or POE). Therefore, the content of PAG, PVE, ECP, or 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 more preferably 90% by mass to 100% by mass, and even more preferably 100% by mass, based on the total amount (100% by mass) of the base oil (A).

[0079] In addition, from the viewpoint of long-term stability required for the refrigerant oil composition, it is preferable that the base oil (A2) is PAG or PVE (that is, it consists only of PAG or PVE). Therefore, the content of PAG or PVE 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 more preferably 90% by mass to 100% by mass, and even more preferably 100% by mass, based on the total amount (100% by mass) of the base oil (A).

[0080] (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 not corresponding to the aforementioned PVE, PAG, ECP, and POE.

[0081] Examples of the mineral oil include those obtained by subjecting paraffinic crude oil, intermediate-base crude oil, or naphthenic crude oil to atmospheric distillation, or by subjecting atmospheric residue obtained by atmospheric distillation of crude oil to vacuum distillation and then performing one or more treatments such as solvent dewaxing, solvent extraction, hydrocracking, solvent deasphalting, catalytic deasphalting, and hydrorefining on the obtained lubricating oil fraction, and oils produced by isomerizing mineral oil-based waxes. 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.

[0082] Examples of the synthetic oils not corresponding to the aforementioned PVE, PAG, ECP, and POE include polyesters, polycarbonates, hydrogenated products of α-olefin oligomers, alicyclic hydrocarbon compounds, alkylated aromatic hydrocarbon compounds, and oils produced by isomerizing GTL WAX (gas to liquid wax) produced by a Fischer-Tropsch process or the like. When the synthetic oil not corresponding to the aforementioned PVE, 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.

[0083] In the refrigerant oil composition of the present embodiment, from the viewpoint of the solubility of the epoxy compound (B), 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 1% by mass or less, still more preferably 0.1% by mass or less, and even more preferably not contain the mineral oil, based on the total amount of the base oil (A).

[0084] (Kinematic viscosity of base oil (A) at 100 °C) The kinematic viscosity of 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 from the viewpoint of improving lubrication performance (load-bearing performance) and sealing performance. Also, from the viewpoint of improving compatibility with the refrigerant, it is preferably 50 mm 2 / s or less, more preferably 40 mm 2 / s or less, still more preferably 30 mm 2 / s or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, it is preferably 3 mm 2 / s to 50 mm 2 / s, more preferably 4 mm 2 / s to 40 mm 2 / s, still 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.

[0085] (Hydroxyl value of base oil (A)) The hydroxyl value of base oil (A) is preferably 30 mgKOH / g or less, more preferably 25 mgKOH / g or less, still more preferably 20 mgKOH / g or less from the viewpoint of improving the thermal stability of the refrigerant oil composition. Also, usually, it is 0.5 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.

[0086] (Number average molecular weight (Mn) of base oil (A)) The number average molecular weight (Mn) of base oil (A) is preferably 300 or more, more preferably 400 or more, still more preferably 500 or more from the viewpoint of improving lubrication performance (load-bearing performance) and sealing performance. Also, from the viewpoint of improving compatibility with the refrigerant, it is preferably 10,000 or less, more preferably 7,000 or less, still 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 still more preferably 500 to 5,000. In this specification, the number average molecular weight (Mn) of the base oil (A) is a value measured by the method described in the examples below.

[0087] <Epoxy compound (B)> The refrigerant oil composition of this embodiment contains an epoxy compound (B) that satisfies the following requirements (B1) and (B2). (B1) It has at least one divalent group represented by the following formula (1) in the molecule.

Chemical formula

[0088] The group represented by the above formula (1) that the epoxy compound (B) has is less likely to decompose the unsaturated fluorinated hydrocarbon compound (HFO) compared to an epoxy compound having a structure with an epoxy group at the molecular end, and is less likely to generate fluorine components (for example, hydrofluoric acid, etc.) generated by the decomposition of the unsaturated fluorinated hydrocarbon compound (HFO) in a high-temperature environment. Also, the trace amount of fluorine components generated reacts with the epoxy groups in the epoxy compound (B) and is trapped in the epoxy compound (B). Due to these functions, it is presumed that the elution of fluorine components into the refrigerant oil composition can be suppressed, and the eluted fluorine components can be trapped, so that an increase in the acid value of the refrigerant oil composition can be suppressed.

[0089] When the above epoxy compound (B) has a molecular weight of 300 or more, the reactivity of the epoxy group can be moderately 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 350 or more. Further, from the viewpoints of solubility in the refrigeration oil and sludge formation after stability evaluation, the molecular weight of the epoxy compound (B) is preferably 2000 or less, more preferably 1500 or less, and even more preferably 1000 or less.

[0090] In the refrigeration oil composition of the present embodiment, from the viewpoint of more easily exhibiting the effect of suppressing the increase in the acid value of the refrigeration oil composition, the content of the epoxy compound (B) is preferably 0.10% by mass or more, more preferably 0.20% by mass or more, even more preferably 0.50% by mass or more, and still more preferably 1.00% by mass or more based on the total amount (100% by mass) of the refrigeration oil composition. The upper limit value of the content of the epoxy compound (B) is not particularly limited, but from the viewpoint of obtaining an effect commensurate with the addition amount, it is preferably 10.00% by mass or less, more preferably 7.00% by mass or less, and even more preferably 5.00% by mass or less. The upper limit and the lower limit of these numerical ranges can be arbitrarily combined. Specifically, it is preferably 0.10% by mass to 10.00% by mass, more preferably 0.20% by mass to 7.00% by mass, even more preferably 0.50% by mass to 5.00% by mass, and still more preferably 1.00% by mass to 5.00% by mass.

[0091] In the present embodiment, the epoxy compound (B) can be used without particular limitation as one or more selected from the group consisting of those satisfying the above two requirements. Specific examples of the epoxy compound (B) include epoxy fatty acid esters, epoxy alicyclic carboxylic acid esters, epoxy vegetable oils, etc. that satisfy the above requirements (B1) and (B2).

[0092] (Epoxy fatty acid ester) Examples of the epoxy fatty acid ester 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 having 1 to 8 carbon atoms, phenol, or an alkylphenol having 7 to 14 carbon atoms.

[0093] As the epoxidized fatty acid ester, from the viewpoint of effectively suppressing the increase in the acid value of the refrigerant oil composition, those represented by the following general formula (1-1) are preferably used.

Chemical formula

[0094] Specific examples of the above epoxidized fatty acid esters include those obtained by epoxidizing butyl esters, hexyl esters, 2-ethylhexyl esters, benzyl esters, cyclohexyl esters, methoxyethyl esters, octyl esters, phenyl esters, or butylphenyl esters of linoleic acid, oleic acid, palmitic acid, linolenic acid, or stearic acid. Examples of commercially available products of the above epoxidized vegetable oils include Sansosizer E-6000 manufactured by Shin Nippon Rika Co., Ltd., Chemisizer T-5000 manufactured by Sanwa Chemical Co., Ltd., and the like.

[0095] (Epoxidized alicyclic carboxylic acid ester) Examples of the above epoxidized alicyclic carboxylic acid esters include those obtained by epoxidizing esters of alicyclic carboxylic acids having 5 to 12 carbon atoms in the ring with alcohols having 1 to 8 carbon atoms, phenols, or alkylphenols having 7 to 14 carbon atoms. The above alicyclic carboxylic acids may be monocarboxylic acids or dicarboxylic acids.

[0096] From the viewpoint of effectively suppressing an increase in the acid value of the refrigerant oil composition, those represented by the following general formula (1-2) are preferably used as the above epoxidized alicyclic carboxylic acid esters.

Chemical formula

[0097] 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 Sansoziser E-PS manufactured by Shin Nippon Rika Co., Ltd.

[0098] (Epoxidized vegetable oil) Examples of the epoxidized vegetable oil include those obtained by epoxidizing vegetable oils such as soybean oil, linseed oil, rice bran oil, and cottonseed oil.

[0099] From the viewpoint of effectively suppressing an increase in the acid value of the refrigerant oil composition, the epoxidized vegetable oil preferably used is one having a group represented by the following general formula (1-3). More specifically, a glycerin ester having one or more groups represented by the following general formula (1-3) is preferable, a triglyceride having one or more groups represented by the following general formula (1-3) is more preferable, and a triglyceride having two or more groups represented by the following general formula (1-3) is even more preferable. [Chemical formula] (In formula (1-3), R 1 is a hydrocarbon group having 4 to 20 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.) The details of the above R 1 are the same as those in the above formula (1-1). In the group represented by the above (1-3), R 1 is preferably an alkyl group having 5 to 12 carbon atoms, p is 1, n is an integer of 1 to 10, and m is 1 or 2.

[0100] Examples of commercially available products of the epoxidized vegetable oil include Sansosizer E-2000H manufactured by Shin Nippon Rika Co., Ltd., Chemisizer SE-80, Chemisizer SE-100, Chemisizer T-3000N, Chemisizer LE-3000, Chemisizer 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.

[0101] <Glycidyl ether compound (C)> The refrigerant oil composition of the present embodiment may further contain a glycidyl ether compound (C). Examples of the glycidyl ether compound (C) 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 an aliphatic polyhydric alcohol or an aromatic compound 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, and the like. Among these, glycidyl ethers derived from linear, branched, or cyclic saturated aliphatic monoalcohols having 6 to 16 carbon atoms (that is, 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, and the like, 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 the oxidation stability at high temperatures can be more easily improved.

[0102] The content of the glycidyl ether compound (C) 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 (C) to 0.10% by mass or more, the acid in the refrigerant oil composition can be appropriately captured, effectively preventing the increase in the acid value of the refrigerant oil composition and facilitating the enhancement of 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 (C) 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. Note that the glycidyl ether compound (C) may be used alone or in combination of two or more.

[0103] <Content ratio of epoxy compound (B) and glycidyl ether compound (C)> In the refrigerant oil composition of the present embodiment, from the viewpoint of more easily exerting the effects of the present invention, the content ratio [(B) / (C)] of the epoxy compound (B) and the glycidyl ether compound (C) is preferably 0.050 or more, more preferably 0.10 or more, still more preferably 0.20 or more in terms of mass ratio, and is preferably 5.0 or less, more preferably 3.5 or less, still more preferably 2.5 or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, it is preferably 0.050 to 5.0, more preferably 0.10 to 3.5, and still more preferably 0.20 to 2.5.

[0104] <Other additives> The refrigerant oil composition of the present embodiment may further contain other additives other than the above components (A), (B), and (C) within a range that does not impair the effects of the present invention. Examples of other additives include one or more selected from the group consisting of antioxidants, stabilizers, extreme pressure agents, and defoaming agents. The total content of these additives is preferably 0% by mass to 10% by mass, more preferably 0.01% by mass to 5% by mass, and still more preferably 0.1% by mass to 3% by mass based on the total amount (100% by mass) of the refrigerant oil composition.

[0105] (Antioxidant) Examples of the antioxidant preferably include one or more selected from the group consisting of phenolic antioxidants and amine antioxidants. 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 is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and still more preferably 0.1% by mass or more based on the total amount (100% by mass) of the refrigerant oil composition. Also, it is preferably 5% by mass or less, more preferably 3% by mass or less, and 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, and still more preferably 0.1% by mass to 1% by mass.

[0106] (Stabilizer) Examples of the stabilizer include aliphatic unsaturated compounds, terpenes having double bonds, and the like. As the 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 is C 20 H 30 O, and 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) are preferable. As the terpenes having a double bond, terpene hydrocarbons having a double bond are preferable, and 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-methylidenedodeca-1,6,10-triene) are more preferable. The stabilizer may be used alone or in combination of two or more.

[0107] (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 preferable. Examples of the phosphorus-based extreme pressure agent include phosphate esters, acidic phosphate esters, phosphite esters, acidic phosphite esters, and amine salts thereof. Among these, from the viewpoints of improving extreme pressure properties and frictional properties, one or more selected from tricresyl phosphate (TCP), trithiophenyl phosphate, tri(nonylphenyl) phosphite, dioleyl hydrogen phosphite, and 2-ethylhexyl diphenyl phosphite are preferable, and tricresyl phosphate (TCP) is more preferable. Examples of the metal salt of carboxylic acid 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 dicarboxylic acids having 3 to 30 carbon atoms are preferable. Moreover, as the metal constituting the metal salt, an alkali metal and an alkaline earth metal are preferable, and an alkali metal is 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, dialkyl thiodipropionates, and the like. From the viewpoints of lubricity and stability, the content of the extreme pressure agent is preferably 0.001 to 5% by mass, more preferably 0.005 to 3% by mass, based on the total amount (100% by mass) of the refrigerant oil composition.

[0108] (Antifoaming agent) Examples of the antifoaming agent include silicone-based antifoaming agents such as silicone oil and fluorinated silicone oil.

[0109] [Method for producing 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 at least one carbon-carbon unsaturated bond.] 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, including a step of mixing base oil (A) and epoxy compound (B), The method for producing the refrigerant oil composition, wherein the epoxy compound (B) satisfies the following requirements (B1) and (B2). (B1) It has at least one oxirane-2,3-diyl group in the molecule. (B2) 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 epoxy compound (B) into the base oil (A) can be mentioned. The glycidyl ether compound (C) and other additives may be blended into the base oil (A) simultaneously with the epoxy compound (B), 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 uniformly disperse by a known method.

[0110] [Physical properties of the refrigerant oil composition] In this embodiment, the physical property values of the refrigerant oil composition after the autoclave test described in the examples below are as follows.

[0111] [Acid value] The acid value of the refrigerant oil composition after the autoclave test described in the examples below is preferably 0.15 mgKOH / g or less, more preferably 0.10 mgKOH / g or less.

[0112] [Fluorine content] The fluorine content in the refrigerant oil composition after the autoclave test described in the examples below is preferably 15 mass ppm or less, more preferably 10 mass ppm or less, and still more preferably 7 mass ppm or less based on the total amount of the refrigerant oil composition.

[0113] [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.

[0114] [Refrigerant] The refrigerant used in this 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 at least one carbon-carbon unsaturated bond. It is a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by

[0115] The general formula (1) represents the types and numbers of elements in the molecule. Specifically, it represents an unsaturated fluorinated hydrocarbon compound with 2 to 6 carbon atoms. Unsaturated fluorinated hydrocarbon compounds with 2 to 6 carbon atoms have physical and chemical properties such as boiling point, freezing point, and latent heat of vaporization required for refrigerants. In the general formula (1), C x The bonding forms of the x carbon atoms represented by are carbon-carbon single bonds, unsaturated bonds such as carbon-carbon double bonds, etc. From the perspective of stability, the carbon-carbon unsaturated bond is preferably a carbon-carbon double bond. The unsaturated fluorinated hydrocarbon compound has at least one unsaturated bond such as a carbon-carbon double bond in the molecule, and the number is preferably 1. That is, C x It is more preferable that at least one of the bonding forms of the x carbon atoms represented by is a carbon-carbon double bond.

[0116] Preferably, examples of the above unsaturated fluorinated hydrocarbon compounds include fluorides of linear or branched chain olefins with 2 to 6 carbon atoms and cyclic olefins with 4 to 6 carbon atoms. 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 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.

[0117] (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 general formula (1) above, 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 still 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.

[0118] The refrigerant may also include 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. The hydrocarbon refrigerant is preferably a hydrocarbon having 1 to 8 carbon atoms, more preferably a hydrocarbon having 1 to 5 carbon atoms, and still more preferably a hydrocarbon having 3 to 5 carbon atoms. 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.

[0119] (Content of unsaturated fluorinated hydrocarbon compound in refrigerant) In this embodiment, the refrigerant contains an unsaturated fluorinated hydrocarbon compound represented by the general formula (1). The content of the unsaturated fluorinated hydrocarbon compound represented by the 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 most preferably 100% by mass based on the total amount of the refrigerant. Even with a refrigerant having a high content of unsaturated fluorinated hydrocarbon compound as described above, the refrigerant oil composition of this embodiment is excellent in the effect of suppressing the increase in acid value.

[0120] (Usage amounts of refrigerant and refrigerant oil composition) In the refrigerant mixture composition for a refrigerator according to this embodiment, the usage amounts of the refrigerant and the refrigerator oil composition are represented by the mass ratio of the refrigerator oil composition to the refrigerant [(refrigerator oil composition) / (refrigerant)], preferably 1 / 99 to 90 / 10, more preferably 5 / 95 to 70 / 30. When the mass ratio of the refrigerator oil composition to the refrigerant is within this range, lubricity and suitable refrigerating capacity in the refrigerator can be obtained.

[0121] [Uses of Refrigerator Oil Composition and Refrigerant Mixture Composition for Refrigerator] The above-mentioned refrigerator oil composition and refrigerant mixture composition for a refrigerator 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.

[0122] [One Aspect of the Present Invention Provided] In one aspect of the present invention, the following [1] to

[11] 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 one or more carbon-carbon unsaturated bonds.] A refrigerator oil composition used in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by the formula, It contains a base oil (A) selected from the group consisting of polyalkylene glycols, polyvinyl ethers, poly(oxy)alkylene glycol or a copolymer of the monoether thereof and polyvinyl ether, and polyol esters, and an epoxy compound (B), The epoxy compound (B) satisfies the following requirements (B1) and (B2), a refrigerator oil composition. (B1) It has at least one divalent group represented by the following formula (1) in the molecule.

Chemical formula

[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, a stabilizer, 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 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 [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, comprising: a step of mixing a base oil (A) selected from the group consisting of polyalkylene glycols, polyvinyl ethers, poly(oxy)alkylene glycol or a copolymer of the poly(oxy)alkylene glycol and its monoether and polyvinyl ether, and polyol esters, and an epoxy compound (B). A method for producing a refrigerating machine oil composition, wherein the epoxy compound (B) satisfies the following requirements (B1) and (B2). (B1) It has at least one divalent group represented by the following formula (1) in the molecule. [Chemical formula] (B2) It has at least one ester group in the molecule. [Examples]

[0123] The present invention will be specifically described by the following examples. However, the present invention is not limited to the following examples.

[0124] [Measurement methods for various physical property values] The measurement of each property of each raw material used in each example and each comparative example and the refrigerating machine oil composition of each example and each comparative example was carried out according to the following procedures. (1) Kinematic viscosity at 100°C The kinematic viscosity at 100°C of the base oil (A) was measured in accordance with JIS K2283:2000. (2) Hydroxyl value The hydroxyl value of the 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 the base oil (A) was measured using a gel permeation chromatography (GPC) apparatus. For GPC, two "TSKgel SuperMultipore HZ-M" manufactured by Tosoh Corporation were sequentially connected as columns, tetrahydrofuran was used as the eluent, and the 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.

[0125] [Details of each component used in the preparation of the refrigerating machine oil composition] Details of each component used in the preparation of the refrigerating machine oil composition are shown below.

[0126] [Base oil (A)] · "PVE1": Polyvinyl ether (copolymer of polyethyl vinyl ether (PEVE) and polyisobutyl vinyl ether (PIBVE), copolymerization ratio (PEVE / PIBVE) = 9 / 1 (molar ratio)), kinematic viscosity at 100 °C = 8.4 mm 2 / s, hydroxyl value = 1 mg KOH / g, number average molecular weight = 940 · "PVE2": Polyethyl vinyl ether, kinematic viscosity at 100 °C = 8.6 mm 2 / s, hydroxyl value = 1 mg KOH / g, number average molecular weight = 1100 · "PAG": Polyoxypropylene glycol, kinematic viscosity at 100 °C = 10.3 mm 2 / s, hydroxyl value = 6 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, hydroxyl value = 1 mg KOH / g, number average molecular weight = 670

[0127] <Epoxy compound (B)> · "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

Chem.

Chem.

[0128] <Glycidyl ether compound (C)> As the glycidyl ether compound (C), 2-ethylhexyl glycidyl ether was used.

[0129] <Other additives> · Antioxidant: di-tert-butyl-p-cresol (DBPC) · Stabilizer: β-pinene · Others: Extreme pressure agent (tricresyl phosphate), silicone-based defoaming agent

[0130] [Examples 1 to 34, Comparative Examples 1 to 16] The above components were mixed to prepare a refrigerant oil composition having the compositions shown in Tables 1 to 3, and an autoclave test described below was conducted. Note that the numerical unit of the blending composition in Tables 1 to 3 is "mass%".

[0131] <Autoclave test> It was carried out in accordance with Appendix C of JIS K2211:2009. Specifically, an autoclave with an internal volume of 200 mL was charged with a refrigerant mixture composition (moisture content 2,000 ppm) obtained by mixing 30 g of the refrigerant oil compositions of Examples 1 to 34 and Comparative Examples 1 to 16 and 30 g of R1234yf, and a metal catalyst composed of iron, copper, and aluminum. Then, after evacuation, it was held at a temperature of 175 °C for 336 hours, and the appearance of the oil and the catalyst (presence or absence of deterioration), and the presence or absence of precipitates (color of the precipitates if any) 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, the acid value of the refrigerant oil composition and the fluorine content in the refrigerant oil composition were evaluated by the method described below.

[0132] (Evaluation of the acid value of the refrigerant oil composition) Measured by the indicator photometric titration method (refer to Appendix 1 in the following JIS standard) in accordance with JIS K2501:2003.

[0133] (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 refrigerant mixture composition for refrigerators 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).

[0134] [Table 1]

[0135] [Table 2]

[0136] [Table 3]

[0137] [Table 4]

[0138] From Tables 1 to 3, the following can be understood. It can be seen that the refrigerant oil compositions of Examples 1 to 34 containing the epoxy compound (B) are excellent in the effect of suppressing the increase in the acid value of the refrigerant oil composition after the autoclave test, and the amount of fluorine in the refrigerant oil composition after the test is also small. In particular, the refrigerant oil compositions of Examples 3, 6, 9, 13, and 14 containing the same amount of the epoxy compound (B) are extremely excellent in the effect of suppressing the increase in the acid value of the refrigerant oil composition after the autoclave test compared to the refrigerant oil composition of Comparative Example 3 containing 3.00% by mass of the epoxidized α-olefin, and it can be seen that the amount of fluorine in the refrigerant oil composition after the test is also small. From the above results, it is presumed that the epoxy compound (B) suppresses the decomposition of the refrigerant and captures fluorine (F - ) eluted into the refrigeration machine oil composition due to the decomposition of the refrigerant, and suppresses the increase in the acid value of the refrigeration machine oil composition by acting to reduce the amount of fluorine (F - ) in the refrigeration machine oil composition.

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 for a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by It contains a base oil (A) selected from the group consisting of polyalkylene glycols, polyvinyl ethers, poly(oxy)alkylene glycol or a copolymer of the monoether thereof and polyvinyl ether, and polyol esters, and an epoxy compound (B). The epoxy compound (B) satisfies the following requirements (B1) and (B2), and is one or more selected from the group consisting of an epoxidized fatty acid ester represented by the following general formula (1-1), an epoxidized alicyclic carboxylic acid ester represented by the following general formula (1-2), and an epoxidized vegetable oil, and the epoxidized vegetable oil is one or more selected from the group consisting of epoxidized soybean oil, epoxidized linseed oil, epoxidized rice bran oil, and epoxidized cottonseed oil. Refrigerant oil composition. (B1) It has at least one divalent group represented by the following formula (1) in the molecule. 【Chemical 1】 (B2) It has at least one ester group in the molecule. [Chemical 2] (In formula (1-1), R 1 is a hydrocarbon group having 4 to 20 carbon atoms, R 2 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 in the plurality of [ ] may be the same or different from each other.) In formula (1-2), R ３ and R ４ are each independently a hydrocarbon group having 4 to 20 carbon atoms.)

2. The refrigerant oil composition according to claim 1, wherein the epoxy compound (B) has a molecular weight of 300 or more.

3. The refrigerant oil composition according to claim 1 or 2, wherein the content of the epoxy compound (B) is 0.10% by mass or more based on the total amount of the refrigerant oil composition.

4. Furthermore, the refrigerant oil composition according to any one of claims 1 to 3, which contains a glycidyl ether compound (C).

5. The refrigerant oil composition according to claim 4, wherein the content ratio [(B) / (C)] of the epoxy compound (B) and the glycidyl ether compound (C) is 0.050 or more and 5.0 or less by mass ratio.

6. Furthermore, the refrigerant oil composition according to any one of claims 1 to 5, which contains one or more additives selected from the group consisting of an antioxidant, a stabilizer, an extreme pressure agent, and an antifoaming agent.

7. The refrigerant oil composition according to any one of claims 1 to 6, wherein the unsaturated fluorinated hydrocarbon compound contains one or more selected from the group consisting of R1234ze, R1234yf, and R1234ye.

8. The refrigerant oil composition according to any one of claims 1 to 7, wherein the refrigerant consists only of the unsaturated fluorinated hydrocarbon compound.

9. 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 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 claims 1 to 8. A refrigerant mixture composition for a refrigerator.

10. 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 method for producing a refrigerant oil composition used for a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by the formula, Including a step of mixing a base oil (A) selected from the group consisting of polyalkylene glycols, polyvinyl ethers, a copolymer of poly(oxy)alkylene glycol or its monoether and polyvinyl ether, and polyol esters, and an epoxy compound (B). The epoxy compound (B) satisfies the following requirements (B1) and (B2), and is one or more selected from the group consisting of an epoxidized fatty acid ester represented by the following general formula (1-1), an epoxidized alicyclic carboxylic acid ester represented by the following general formula (1-2), and an epoxidized vegetable oil, and the epoxidized vegetable oil is one or more selected from the group consisting of epoxidized soybean oil, epoxidized linseed oil, epoxidized rice bran oil, and epoxidized cottonseed oil. A method for producing a refrigerant oil composition. (B1) It has at least one divalent group represented by the following formula (1) in the molecule. [Chemical Formula 3] (B2) It has at least one ester group in the molecule. 【Chemical 4】 (In the formula (1-1), R1 is a hydrocarbon group having 4 to 20 carbon atoms, R2 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 in the plurality of [ ] may be the same or different from each other. In formula (1-2), R ３ and R ４ are each independently a hydrocarbon group having 4 to 20 carbon atoms.)

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