Refrigeration oil composition and refrigeration mixture composition

Abstract

The present invention addresses the problem of providing a refrigerator oil composition which can effectively suppress an increase in acid value, even if there is an increase in the proportion of a unsaturated fluorohydrocarbon compound (HFO) in a refrigerant. This problem is solved by a refrigerator oil composition used for a refrigerant that contains one or more unsaturated fluorohydrocarbon compounds selected from compounds represented by the following general formula (1): CxFyHz [where x is an integer of 2-6, y is an integer of 1-11, z is an integer of 1-11, and one or more unsaturated carbon-carbon bonds are included in the molecule]. The refrigerator oil composition contains (A) a base oil and (B) one or more silicone compounds selected from the group consisting of (B1) unmodified silicone and (B2) modified silicone, wherein the content of the silicone compound (B) is not less than 0.05 mass% with respect to the entire amount of the refrigerator oil composition.

Description

[Technical Field]

[0001] The present invention relates to a refrigeration oil composition and a mixed composition for refrigeration. In this specification, "refrigeration mixed composition" refers to a composition obtained by mixing "refrigeration oil composition" and "refrigerant." [Background technology]

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

[0003] In refrigeration systems such as compression chillers, fluorinated hydrocarbon compounds with lower environmental impact are increasingly being used as refrigerants, replacing hydrochlorofluorocarbons (HCFCs), which were previously widely used. These fluorinated hydrocarbon compounds include saturated fluorinated hydrocarbon compounds (HFCs) such as 1,1,1,2-tetrafluoroethane (R134a), difluoromethane (R32), and 1,1-difluoroethane (R152a). Furthermore, 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), which have low global warming potential (GWP), is also being considered (see, for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Special Publication No. 2006-503961 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, while unsaturated fluorinated hydrocarbons (HFOs) have the advantage of a low global warming potential (GWP), they have the disadvantage of inferior thermal stability at high temperatures compared to saturated fluorinated hydrocarbons (HFCs). Therefore, an increase in the content of unsaturated fluorinated hydrocarbons (HFOs) in the refrigerant tends to raise the acid value of the refrigerant oil composition.

[0006] Furthermore, in recent years, refrigeration units have become more compact and high-performance, and their operating conditions have become more demanding than ever before. As a result, refrigeration oil compositions are required to have a higher level of quality than ever before. For example, while the amount of refrigeration oil composition used in the equipment is decreasing due to the miniaturization of refrigeration units, the increased demanding operating conditions have led to frictional heat in the sliding parts of the compressor, making it easier for localized high temperatures to occur. When refrigeration oil compositions are exposed to such areas, the acid value of the refrigeration oil composition tends to increase more easily.

[0007] Therefore, there is a need to create a refrigeration oil composition that can effectively suppress the rise in acid value even when the content of unsaturated fluorinated hydrocarbon compounds (HFOs) in the refrigerant is increased.

[0008] The present invention has been made in view of such needs, and aims to provide a refrigeration oil composition that can effectively suppress the rise in acid value even when the content of unsaturated fluorinated hydrocarbon compounds (HFOs) in the refrigerant is increased, and a mixed composition for refrigeration containing the refrigeration oil composition. [Means for solving the problem]

[0009] The inventors diligently conducted research to solve the above problems. As a result, they found that a refrigeration oil composition containing a specific amount or more of one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2) 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 F y H z ···(1) [In the general formula (1), x is an integer of 2 to 6, y is an integer of 1 to 11, z is an integer of 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds.] A refrigerant oil composition used in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by, containing base oil (A) and one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2), A refrigerant oil composition in which the content of the silicone compound (B) is 0.05% by mass or more based on the total amount of the refrigerant oil composition. [2] 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 selected from the compounds represented by, and the refrigerant oil composition according to [1] above. 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 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 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 one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2), A method for producing a refrigerant oil composition in which the blending amount of the silicone compound (B) is 0.05% by mass or more based on the total amount of the refrigerant oil composition. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a refrigeration oil composition that can effectively suppress the rise in acid value even when the content of unsaturated fluorinated hydrocarbon compounds (HFOs) in the refrigerant is increased, and a mixed composition for refrigeration containing the refrigeration oil composition. [Modes for carrying out the invention]

[0012] The upper and lower limits of the numerical ranges described herein can be combined in any way. For example, if 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 within the scope of the present invention. Furthermore, unless otherwise specified, the numerical range "lower limit to upper limit" described herein means that the value is greater than or equal to the lower limit and less than or equal to the upper limit. Furthermore, in this specification, the numerical values ​​in the examples are values ​​that can be used as upper or lower limits.

[0013] [Aspects of refrigerant oil composition] The refrigeration oil composition of this embodiment is the following general formula (1) C x F y H z ...(1) This is a refrigerant oil composition used in a refrigerant that contains one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the general formula (1) above: [wherein x is an integer between 2 and 6, y is an integer between 1 and 11, and z is an integer between 1 and 11, and the molecule has one or more carbon-carbon unsaturated bonds.] The refrigeration oil composition of this embodiment contains a base oil (A) and one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2). The content of silicone compound (B) is 0.05% by mass or more on a basis of the total amount of the refrigeration oil composition.

[0014] Based on the idea that one of the factors that makes the acid value of a refrigeration oil composition more likely to increase as the content of unsaturated fluorinated hydrocarbon compounds (HFOs) in the refrigerant increases is the fluorine content generated by the decomposition of unsaturated fluorinated hydrocarbon compounds (HFOs) under high-temperature conditions, the inventors conducted various studies. As a result, we found that a refrigeration oil composition containing a specific amount or more of one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2) can suppress the increase in fluorine concentration in the refrigeration oil composition caused by fluorine content resulting from the decomposition of unsaturated fluorinated hydrocarbon compounds (HFOs) under high-temperature conditions, thereby suppressing the increase in the acid value of the refrigeration oil composition.

[0015] The mechanism by which the effects of the present invention are achieved is presumed to be as follows. In other words, the fluorine content (e.g., hydrofluoric acid) generated by the decomposition of unsaturated fluorinated hydrocarbon compounds (HFOs) under high-temperature conditions is highly reactive with the siloxane bonds in the silicone compound (B), and therefore the fluorine content is captured within the silicone compound (B). As a result, it is presumed that the elution of fluorine into the refrigeration oil composition is suppressed, and the increase in the acid value of the refrigeration oil composition can be suppressed.

[0016] In the following explanation, "base oil (A)" and "silicone compound (B)" will also be referred to as "component (A)" and "component (B)," respectively.

[0017] The refrigeration oil composition of this embodiment may consist only of component (A) and component (B), but may also contain other components other than component (A) and component (B) as long as the effects of the present invention are not impaired. In the refrigeration oil composition of this embodiment, the total content of component (A) and component (B) is preferably 80% to 100% by mass, more preferably 85% to 100% by mass, and even more preferably 90% to 100% by mass, based on the total amount (100% by mass) of the refrigeration oil composition.

[0018] The following describes in detail each component contained in the refrigeration oil composition of this embodiment.

[0019] <Base oil (A)> The refrigeration oil composition of this embodiment contains a base oil (A). In the refrigeration oil composition of this embodiment, the base oil (A) content is preferably 85.0% by mass or more, more preferably 90.0% by mass or more, and even more preferably 92.0% by mass or more, based on the total amount (100% by mass) of the refrigeration oil composition, from the viewpoint of the long-term stability required for a refrigeration oil composition. Furthermore, from the viewpoint of making it easier to ensure the content of silicone compound (B) in the refrigeration oil composition, and further from the viewpoint of making it easier to ensure the content of additives other than silicone compound (B), the base oil (A) content is preferably 99.0% by mass or less, more preferably 98.5% by mass or less, and even more preferably 98.0% by mass or less. The upper and lower limits of these numerical ranges can be combined in any way. Specifically, they are preferably 85.0% by mass to 99.0% by mass, more preferably 90.0% by mass to 98.5% by mass, and even more preferably 92.0% by mass to 98.0% by mass.

[0020] As the base oil (A), any base oil commonly used in refrigeration oil compositions can be used without particular limitations. For example, as the base oil (A), one or more selected from the group consisting of synthetic oils and mineral oils can be used. In this embodiment, the refrigeration oil composition is preferably a synthetic oil from the viewpoint of the solubility of the silicone compound (B). Furthermore, among synthetic oils, from the viewpoint of improving the thermal stability of the refrigeration oil composition, it is preferable that the base oil (A) contains one or more base oils 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 copolymers of the monoether thereof and polyvinyl ether (hereinafter also referred to as "ECP"), and polyol esters (hereinafter also referred to as "POE") (hereinafter also referred to as "base oil (A1)"). Furthermore, from the viewpoint of improving compatibility with refrigerants, improving hydrolysis resistance, and further improving the thermal stability of the refrigerant oil composition, it is more preferable that base oil (A) includes one or more base oils selected from the group consisting of PAG and PVE (hereinafter also referred to as "base oil (A2)"). The following provides a detailed explanation of PAG, PVE, ECP, and POE.

[0021] (Polyalkylene glycols (PAGs)) As for PAG, any PAG used as a base oil in a refrigeration oil composition can be used without particular limitation, but it is preferable that it be a polymer (A-1) represented by the following general formula (A-1). R 13a -[(OR 14a ) p -OR 15a ] q (A-1) Furthermore, if PAG is included in the base oil (A), one type of PAG may be used alone, or two or more types may be used in combination.

[0022] In the above general formula (A-1), R 13a R 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. 14a This represents an alkylene group with 2 to 4 carbon atoms, R 15a This 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. Substituents that the heterocyclic group may have include alkyl groups having 1 to 10 carbon atoms (preferably 1 to 6, more preferably 1 to 3); cycloalkyl groups having 3 to 10 carbon atoms (preferably 3 to 8, more preferably 5 or 6); aryl groups having 6 to 18 carbon atoms (preferably 6 to 12); halogen atoms (fluorine, chlorine, bromine, iodine); cyano groups; nitro groups; hydroxyl groups; amino groups, etc. These substituents may be further substituted with any of the substituents described above.

[0023] q is an integer between 1 and 6, preferably between 1 and 3, and more preferably 1. Note that q is R in the general formula (A-1) above. 13a It is determined according to the number of bonding sites. For example, R 13a If is an alkyl group or acyl group, then q becomes 1, R 13a If is a hydrocarbon group or a heterocyclic group and the valency of the group is 2, 3, 4, 5, or 6, then q will be 2, 3, 4, 5, or 6, respectively. p is OR 14a The number of repeating units is usually 1 or more, and preferably a number such that p × q is between 6 and 80. The value of p is set as appropriate to adjust the kinematic viscosity of the base oil (A) at 40°C to an appropriate range, and is not particularly limited as long as the kinematic viscosity at 40°C is adjusted to an appropriate range. Note that there are multiple R 14a These may be the same or they may be different from each other. Also, if q is 2 or more, there may be multiple R in one molecule. 15a They may be the same, or they may be different from one another.

[0024] R 13a and R 15a Examples of the monovalent hydrocarbon groups represented above include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, and various decyl groups; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, various propylcyclohexyl groups, and various dimethylcyclohexyl groups; aryl groups such as phenyl group, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, and various naphthyl groups; and arylalkyl groups such as benzyl group, various phenylethyl groups, various methylbenzyl groups, various phenylpropyl groups, and various phenylbutyl groups. The alkyl groups may be linear or branched. Here, "various" refers to hydrocarbon groups that are "linear, branched, or cyclic." For example, "various butyl groups" refers to various butyl groups such as "n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, cyclobutyl group," etc. Furthermore, for groups with a cyclic structure, this indicates that positional isomers such as ortho, meta, and para areomers are included, and the same applies hereafter. R 13a and R 15a The number of carbon atoms in the monovalent hydrocarbon group represented by is preferably 1 to 10, more preferably 1 to 6, and even 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 above-mentioned acyl group having 2 to 10 carbon atoms, represented by , may be linear, branched, or cyclic. The alkyl group portion may be the above-mentioned R 13a and R 15a Examples of hydrocarbon groups represented by include those with 1 to 9 carbon atoms. R 13a and R 15a The number of carbon atoms in the acyl group represented by is preferably 2 to 8, more preferably 2 to 6, from the viewpoint of compatibility with the refrigerant.

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

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

[0028] R 13a and R 15a The heterocyclic group represented above may have substituents, and these substituents may be bonded to the oxygen atom in the general formula (A-1). As described above, the substituents are alkyl groups having 1 to 6 carbon atoms, and alkyl groups having 1 to 3 carbon atoms are more preferred. The number of ring-forming atoms in the above heterocyclic group is preferably 3 to 10, more preferably 3 to 6, from the viewpoint of compatibility with the refrigerant.

[0029] R 14aExamples of alkylene groups represented by the above include C2 alkylene groups such as dimethylene group (-CH2CH2-) and ethylene group (-CH(CH3)-); C3 alkylene groups such as trimethylene group (-CH2CH2CH2-), propylene group (-CH(CH3)CH2-), propyridene group (-CHCH2CH3-), and isopropylidene group (-C(CH3)2-); and C4 alkylene groups such as tetramethylene group (-CH2CH2CH2CH2-), 1-methyltrimethylene group (-CH(CH3)CH2CH2-), 2-methyltrimethylene group (-CH2CH(CH3)CH2-), and butylene group (-C(CH3)2CH2-). Among these, R 14a A propylene group (-CH(CH3)CH2-) is preferred.

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

[0031] Among the polymers (A-1) represented by the above general formula (A-1), one or more 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), polyoxyethylene 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 are preferred.

[0032] [ka] (In formula (A-1-i), p1 represents a number greater than or equal to 1, preferably a number between 6 and 80.)

[0033] [ka] (In formula (A-1-ii), p2 and p3 each independently represent a number greater than or equal to 1, preferably a number such that the value of p2 + p3 is between 6 and 80.)

[0034] [ka] (In formula (A-1-iii), p4 represents a number greater than or equal to 1, preferably a number between 6 and 80.)

[0035] [ka] (In formula (A-1-iv), p5 represents a number greater than or equal to 1, preferably a number between 6 and 80.)

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

[0037] (Polyvinyl ethers (PVE)) PVE is a polymer having one or more constituent units derived from vinyl ether, and PVE used as a base oil in refrigeration oil compositions can be used without particular limitations. Furthermore, if PVE is included in the base oil (A), PVE may be used alone or in combination of two or more types. From the viewpoint of compatibility with refrigerants, PVE is preferably a polymer having one or more constituent units derived from vinyl ether and an alkyl group having 1 to 4 carbon atoms in its side chain. From the viewpoint of further improving compatibility with refrigerants, the alkyl group is preferably a methyl group or an ethyl group, with a methyl group being more preferred.

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

[0039] [ka]

[0040] In formula (A-2), R 1a , R 2a , and R 3a Each of these independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. 4a This represents a divalent hydrocarbon group with 2 to 10 carbon atoms. 5a represents a hydrocarbon group with 1 to 10 carbon atoms. r represents OR 4a The number of repeating units is usually 0 to 10, but preferably 0 to 5, more preferably 0 to 3, and even more preferably 0. Note that OR is included in the constituent unit represented by the above general formula (A-2). 4a If multiple ORs exist, 4a They may be the same, or they may be different from one another.

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

[0042] R 1a , R 2a , and R 3a The number of carbon atoms in the hydrocarbon group represented is preferably 1 to 6, more preferably 1 to 3. R 1a , R2a , and R 3a Each of these is independently preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and even more preferably a hydrogen atom.

[0043] R 4a Examples of divalent hydrocarbon groups having 2 to 10 carbon atoms represented by include: divalent aliphatic groups such as ethylene, 1,2-propylene, 1,3-propylene, various butylene, various pentylene, various hexylene, various heptylene, various octylene, various nonylene, and various desilene; divalent alicyclic groups such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, and propylcyclohexane; divalent aromatic groups such as various phenylene, various methylphenylene, various ethylphenylene, various dimethylphenylene, and various naphthylene; divalent alkyl aromatic groups having monovalent bonding sites on both the alkyl and aromatic portions of alkyl aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; and divalent alkyl aromatic groups having bonding sites on the alkyl portion of polyalkyl aromatic hydrocarbons such as xylene and diethylbenzene. R 4a The number of carbon atoms in the hydrocarbon group represented is preferably 2 to 6, more preferably 2 to 4. R 4a The aliphatic group is preferably a divalent aliphatic group having 2 to 10 carbon atoms, and more preferably a divalent aliphatic group having 2 to 4 carbon atoms.

[0044] R 5aExamples of hydrocarbon groups having 1 to 10 carbon atoms represented include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, various butyl, various pentyl, various hexyl, various heptyl, various octyl, various nonyl, and various decyl groups; cycloalkyl groups such as cyclopentyl, cyclohexyl, various methylcyclohexyl, various ethylcyclohexyl, various propylcyclohexyl, and various dimethylcyclohexyl groups; aryl groups such as phenyl, various methylphenyl, various ethylphenyl, various dimethylphenyl, various propylphenyl, various trimethylphenyl, various butylphenyl, and various naphthyl groups; and arylalkyl groups such as benzyl, various phenylethyl, various methylbenzyl, various phenylpropyl, and various phenylbutyl groups. R 5a The number of carbon atoms in the hydrocarbon group represented is preferably 1 to 8, more preferably 1 to 6. R 5a From the viewpoint of further improving compatibility with the refrigerant, an alkyl group having 1 to 6 carbon atoms is preferred, an alkyl group having 1 to 4 carbon atoms is more preferred, a methyl group or an ethyl group is even more preferred, and a methyl group is even more preferred.

[0045] The number of constituent units (degree of polymerization) represented by the above general formula (A-2) is appropriately selected according to the required kinematic viscosity of the base oil (A). Furthermore, the polymer having the constituent unit represented by the general formula (A-2) above may be a homopolymer having only one type of the constituent unit, or a copolymer having two or more types of the constituent unit. When the polymer is a copolymer, there are no particular restrictions on the form of copolymerization; it may be a block copolymer, a random copolymer, or a graft copolymer.

[0046] The terminal portion of polymer (A-2) may be modified to include a monovalent group derived from saturated hydrocarbons, ethers, alcohols, ketones, amides, nitriles, etc. Among these, it is preferable that one terminal portion of polymer (A-2) is a group represented by the following general formula (A-2-i).

[0047] [ka]

[0048] In formula (A-2-i), * indicates the bond position with the carbon atom in the constituent unit represented by the general formula (A-2) above. In formula (A-2-i), R 6a , R 7a , and R 8a Each of these independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, with a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms being preferred, and a hydrogen atom or an alkyl group having 1 to 3 carbon atoms being more preferred. R 6a , R 7a , and R 8a As a hydrocarbon group having 1 to 8 carbon atoms represented by the above general formula (A-2), R 1a , R 2a , and R 3a The same examples listed as hydrocarbon groups with 1 to 8 carbon atoms are included.

[0049] In the above equation (A-2-i), R 9a This 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 equation (A-2-i), r1 is OR 9a The number of repeating units is usually 0 to 10, but preferably 0 to 5, more preferably 0 to 3, and even more preferably 0. Note that OR is included in the constituent unit represented by the above general formula (A-2-i). 9a If multiple ORs exist, 9a They may be the same, or they may be different from one another. R 9a As a divalent hydrocarbon group having 2 to 10 carbon atoms represented by the above general formula (A-2), R 4a The same divalent hydrocarbon groups with 2 to 10 carbon atoms represented by the formula are listed below.

[0050] In formula (A-2-i), R 10arepresents a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrocarbon group having 1 to 8 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms. In addition, R 10a when r1 in the above general formula (A-2-i) is 0, an alkyl group having 1 to 6 carbon atoms is preferred, and when r1 is 1 or more, an alkyl group having 1 to 4 carbon atoms is preferred. 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 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).

[0051] Regarding 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 the definitions in the above general formula (A-2-i). Also, 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 of poly(oxy)alkylene glycol or its monoether and polyvinyl ether (ECP)) The copolymer (ECP) of poly(oxy)alkylene glycol or its monoether and polyvinyl ether may be any copolymer having constituent units derived from poly(oxy)alkylene glycol or its monoether and constituent units derived from polyvinyl ether. Note that "poly(oxy)alkylene glycol" refers to both polyalkylene glycol and polyoxyalkylene glycol. Furthermore, if the base oil (A) contains ECP, one type of ECP may be used alone, or two or more types may be used in combination. Among the ECPs, it is preferable that the copolymer represented by the following general formula (A-3-i) (A-3-i) or the copolymer represented by the general formula (A-3-ii) (A-3-ii).

[0055] [ka]

[0056] In general formulas (A-3-i) and (A-3-ii), R 1c , R 2c , and R 3c Each of these independently represents either a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. R 4c Each of these independently represents a hydrocarbon group having 1 to 10 carbon atoms. R 5c Each of these independently represents an alkylene group having 2 to 4 carbon atoms. R 6c Each of these independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted ring-forming alicyclic group having 3 to 20 carbon atoms, a substituted or unsubstituted ring-forming aromatic group having 6 to 24 carbon atoms, an acyl group having 2 to 20 carbon atoms, or an oxygen-containing hydrocarbon group having 2 to 50 carbon atoms. Note, R 1c , R 2c , R 3c , R 4c , R 5c , and R 6c If multiple such units exist, they may be identical or different for each constituent unit. X C and Y C Each of these 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 OR 5c OR is the average value of the number of units represented by it, which is a number of 1 or more, preferably a number between 1 and 50. 5c If multiple ORs exist, 5c These may be the same or they may be different. 5c " indicates a constituent unit derived from poly(oxy)alkylene glycol or its monoether. In the general formula (A-3-i), u represents a number greater than or equal to 0, preferably between 0 and 50, and w represents a number greater than or equal to 1, preferably between 1 and 50. In general formula (A-3-ii), x and y each independently represent a number of 1 or more, preferably a number between 1 and 50. The values ​​of v, u, w, x, and y mentioned above are not particularly restricted, as long as they are adjusted according to the required hydroxyl value of the base oil (A).

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

[0059] R 1c , R 2c , and R 3c As for hydrocarbon groups having 1 to 8 carbon atoms that can be selected, the R in general formula (A-1) is 1a , R 2a , and R 3a Examples of monovalent hydrocarbon groups with 1 to 8 carbon atoms that can be selected as such include the same groups. R 1c , R 2c , and R 3cThe number of carbon atoms in the hydrocarbon group that can be selected 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 of these elements is independently preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and even more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Also, R 1c , R 2c , and R 3c Preferably, at least one of them is a hydrogen atom, R 1c , R 2c , and R 3c It is more preferable that all of them are hydrogen atoms.

[0060] R 4c As for hydrocarbon groups having 1 to 10 carbon atoms that can be selected, the R in general formula (A-2) is 5a Examples include the same hydrocarbon groups with 1 to 10 carbon atoms that can be selected as such. R 4c The number of carbon atoms in the hydrocarbon group that can be selected is preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 4.

[0061] R 5c The alkylene group that can be selected is R in general formula (A-1). 14a Examples of selectable alkylene groups with 2 to 4 carbon atoms include the same groups as the alkylene group, preferably a propylene group (-CH(CH3)CH2-). Furthermore, in copolymer (A-3-i) or copolymer (A-3-ii), the content of oxypropylene units (-OCH(CH3)CH2-) is determined by the oxyalkylene (OR) content, which is a constituent unit derived from poly(oxy)alkylene glycol or its monoether in copolymer (A-3-i) or copolymer (A-3-ii). 5c Based on the total amount (100 mol%), the amount is preferably 50 mol% to 100 mol%, more preferably 65 mol% to 100 mol%, and even more preferably 80 mol% to 100 mol%.

[0062] R 6c Examples of C1-C20 alkyl groups that can be selected include methyl groups, ethyl groups, various propyl groups, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, and various decyl groups. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 3.

[0063] R 6c Examples of alicyclic groups with 3 to 20 carbon atoms that can be selected as ring-forming groups include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, and cyclodecyl group. The number of ring-forming carbon atoms in the alicyclic group is preferably 3 to 10, more preferably 3 to 8, and even more preferably 3 to 6. The alicyclic group may have the aforementioned substituents, and alkyl groups are preferred as the substituents.

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

[0065] R 6c Examples of acyl groups with 2 to 20 carbon atoms that can be selected as ring-forming groups include acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, piperoyl, benzoyl, and toluyl groups. The number of carbon atoms in the acyl group is preferably 2 to 10, preferably 2 to 8, and more preferably 2 to 6.

[0066] R 6c Examples of oxygen-containing hydrocarbon groups having 2 to 50 carbon atoms that can be selected include methoxymethyl group, methoxyethyl group, methoxypropyl group, 1,1-bismethoxypropyl group, 1,2-bismethoxypropyl group, ethoxypropyl group, (2-methoxyethoxy)propyl group, and (1-methyl-2-methoxy)propyl group. The carbon-containing hydrocarbon group preferably has 2 to 20 carbon atoms, more preferably 2 to 10, and even more preferably 2 to 6 carbon atoms.

[0067] X C , Y C Examples of C1-C20 hydrocarbon groups that can be selected include C1-C20 (preferably 1-10, more preferably 1-6, even more preferably 1-3) alkyl groups, substituted or unsubstituted ring-forming C3-C20 (preferably 3-10, more preferably 3-8, even more preferably 3-6) cycloalkyl groups, substituted or unsubstituted phenyl groups, substituted or unsubstituted naphthyl groups, and C7-C20 (preferably 7-13) arylalkyl groups.

[0068] (Polyol esters (POE)) Examples of POEs include esters of diols or polyols with fatty acids. When POE is present in the base oil (A), one type of POE may be used alone, or two or more types may be used in combination. POE is preferably an ester of a diol or 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, and 1,12-dodecanediol.

[0070] Examples of polyols include trimethylolethane, trimethylolpropane, trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol, di-(pentaerythritol), tri-(pentaerythritol), glycerin, polyglycerin (2-20 mers of glycerin), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol-glycerin condensate, adonitol, arabitol, xylitol, mannitol, and other polyhydric alcohols; sugars such as xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose, raffinose, gentianose, and meridinetose; and their partial ethers, methyl glucosides (glycosides), etc. Among these, hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol, di-(pentaerythritol), and tri-(pentaerythritol) are preferred. A hindered alcohol refers to an alcohol having a quaternary carbon atom bonded to four carbon atoms.

[0071] From the viewpoint of lubrication performance, the number of carbon atoms in the fatty acid is preferably 3 or more, more preferably 4 or more, even 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, even more preferably 12 or less, and even more preferably 10 or less. Note that the number of carbon atoms in the above-mentioned fatty acids also includes the carbon atoms of the carboxyl group (-COOH) that the fatty acid possesses. Furthermore, the fatty acid may be either a linear fatty acid or a branched fatty acid, but linear fatty acids are preferred from the viewpoint of lubrication performance, and branched fatty acids are preferred from the viewpoint of hydrolysis stability. In addition, the fatty acid may be either a saturated fatty acid or an unsaturated fatty acid.

[0072] Examples of fatty acids include straight-chain or branched fatty acids 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, eicosanic acid, and oleic acid, or so-called neoacids in which the α-carbon atoms are quaternary. More specifically, isobutyric acid, valeric acid (n-pentanoic acid), caproic acid (n-hexanoic acid), enanthic acid (n-heptanoic acid), caprylic acid (n-octanoic acid), pelargonic acid (n-nonanoic acid), capric acid (n-decanoic acid), oleic acid (cis-9-octadecenoic acid), isopentanoic acid (3-methylbutanoic acid), 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, etc. are preferred.

[0073] The POE may be a partial ester in which some of the hydroxyl groups of the polyol remain unesterified, or it may be a complete ester in which all hydroxyl groups are esterified. Furthermore, the POE may be a mixture of a partial ester and a complete ester, but a complete ester is preferred.

[0074] As for POE, from the viewpoint of superior hydrolysis stability, esters of hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol, di-(pentaerythritol), and tri-(pentaerythritol) are preferred, esters of neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, and pentaerythritol are more preferred, and pentaerythritol esters are even more preferred from the viewpoint of particularly superior compatibility with refrigerants and hydrolysis stability.

[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; and trimethylolpropane with isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid. Examples include triesters of trimethylolbutane with one or more fatty acids selected from the group consisting of hexanoic 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; and 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.

[0076] Furthermore, the esters of two or more fatty acids may also be mixtures of two or more esters of one fatty acid and a polyol. Among POEs, esters of two or more mixed fatty acids and polyols are preferred from the viewpoint of improving low-temperature characteristics and compatibility with refrigerants.

[0077] (Preferred embodiment of base oil (A)) In the refrigeration oil composition of this embodiment, the main component of base oil (A) is preferably base oil (A1), and more preferably base oil (A2). In this specification, "main component" means the component that is present in the highest concentration. The content of base oil (A1) or base oil (A2) in base oil (A) is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, even more preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, even more preferably 90% to 100% by mass, and most preferably 100% by mass, based on the total amount (100% by mass) of base oil (A).

[0078] Here, the base oil (A1) is preferably PAG, PVE, ECP, or POE (i.e., consisting only of PAG, PVE, ECP, or POE). Therefore, the content of PAG, PVE, ECP, or POE in the base oil (A) is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, even more preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, even more preferably 90% to 100% by mass, and most preferably 100% by mass, based on the total amount (100% by mass) of the base oil (A).

[0079] Furthermore, it is preferable that the base oil (A2) is PAG or PVE (i.e., consists solely of PAG or PVE). Therefore, the content of PAG or PVE in base oil (A) is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, even more preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, even more preferably 90% to 100% by mass, and most preferably 100% by mass, based on the total amount (100% by mass) of base oil (A).

[0080] (Other base oils) Base oil (A) may further contain other base oils, provided that they do not impair the effects of the present invention. Other base oils include one or more selected from the group consisting of mineral oil and synthetic oils that do not fall under the aforementioned PVE, PAG, ECP, and POE.

[0081] Examples of mineral oils include oils obtained by distilling paraffinic crude oil, intermediate-base crude oil, or naphthenic crude oil at atmospheric pressure, or by performing one or more treatments such as solvent delamination, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, and hydrorefining on a lubricating oil fraction obtained by vacuum distillation of the atmospheric residue obtained from atmospheric distillation of crude oil, and oils produced by isomerizing mineral oil-based waxes. Furthermore, if mineral oil is included in the base oil (A), one type of mineral oil may be used alone, or two or more types may be used in combination.

[0082] Examples of synthetic oils that do not fall under the aforementioned PVE, PAG, ECP, and POE include polyesters, polycarbonates, hydrogenated α-olefin oligomers, alicyclic hydrocarbon compounds, alkylated aromatic hydrocarbon compounds, and oils produced by isomerizing GTL WAX (gastric liquid wax) manufactured by processes such as the Fischer-Tropsch process. Furthermore, if the base oil (A) contains synthetic oils that do not fall under the aforementioned PVE, PAG, ECP, and POE categories, such synthetic oils may be used individually or in combination of two or more types.

[0083] In the refrigeration oil composition of this embodiment, from the viewpoint of the solubility of the silicone compound (B), it is preferable that the mineral oil content be low. Specifically, the mineral oil content is preferably 10% by mass or less, more preferably 1% by mass or less, even more preferably 0.1% by mass or less, and even more preferably no mineral oil at all, based on the total amount of base oil (A).

[0084] (Kinematic viscosity of base oil (A) at 100°C) The kinematic viscosity of the base oil (A) at 100°C is preferably 3 mm from the viewpoint of improving lubrication performance (load-bearing capacity) and sealing performance. 2 / s or more, more preferably 4 mm2 / s or more, more preferably 5mm 2 It is 1 / s or more. Furthermore, from the viewpoint of improving compatibility with the refrigerant, 50 mm is preferable. 2 / s or less, more preferably 40mm 2 / s or less, more preferably 30mm 2 It is less than or equal to / s. The upper and lower limits of these numerical ranges can be combined in any way. Specifically, 3 mm is preferred. 2 / s~50mm 2 / s, more preferably 4mm 2 / s~40mm 2 / s, more preferably 5mm 2 / s~30mm 2 It is / s. In this specification, the kinematic viscosity of base oil (A) at 100°C is the value measured in accordance with JIS K2283:2000.

[0085] (Hydroxy value of base oil (A)) The hydroxyl value of the base oil (A) is preferably 30 mg KOH / g or less, more preferably 25 mg KOH / g or less, and even more preferably 20 mg KOH / g or less, from the viewpoint of improving the thermal stability of the refrigeration oil composition. It is also usually 0.5 mg KOH / g or more. In this specification, the hydroxyl value of base oil (A) is the value measured by neutralization titration in accordance with JIS K0070:1992.

[0086] (Number average molecular weight (Mn) of base oil (A)) The number-average molecular weight (Mn) of the base oil (A) is preferably 300 or more, more preferably 400 or more, and even more preferably 500 or more, from the viewpoint of improving lubrication performance (load-bearing capacity) and sealing performance. Furthermore, from the viewpoint of improving compatibility with the refrigerant, it is preferably 10,000 or less, more preferably 7,000 or less, and even more preferably 5,000 or less. The upper and lower limits of these numerical ranges can be combined in any way. Specifically, they are preferably 300 to 10,000, more preferably 400 to 7,000, and even more preferably 500 to 5,000. In this specification, the number-average molecular weight (Mn) of the base oil (A) is the value measured by the method described in the examples below.

[0087] <Silicone compound (B)> The refrigeration oil composition of this embodiment contains one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2). The siloxane bonds in the polysiloxane skeleton of silicone compound (B) are highly reactive with fluorine (e.g., hydrofluoric acid) produced by the decomposition of unsaturated fluorinated hydrocarbon compounds (HFOs) under high-temperature conditions. Therefore, silicone compound (B) has the function of incorporating and capturing this fluorine into its molecule. It is presumed that this function suppresses the elution of fluorine into the refrigeration oil composition and thus suppresses the increase in the acid value of the refrigeration oil composition.

[0088] In the refrigeration oil composition of this embodiment, the content of silicone compound (B) must be 0.05% by mass or more based on the total amount (100% by mass) of the refrigeration oil composition. If the content of silicone compound (B) is less than 0.05% by mass, the elution of fluorine into the refrigeration oil composition cannot be sufficiently suppressed, and the effect of suppressing the rise in the acid value of the refrigeration oil composition cannot be fully exerted. Here, from the viewpoint of making it easier to exert the effect of suppressing the rise in the acid value of the refrigeration oil composition, the content of silicone compound (B) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, even more preferably 0.8% by mass or more, and still more preferably 1.0% by mass or more, based on the total amount (100% by mass) of the refrigeration oil composition. There is no particular upper limit to the content of silicone compound (B), but from the viewpoint of obtaining an effect commensurate with the amount added, it is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, and even more preferably 3.0% by mass or less. The upper and lower limits of these numerical ranges can be combined in any way. Specifically, preferably 0.1% to 5.0% by mass, more preferably 0.3% to 4.0% by mass, even more preferably 0.5% to 3.0% by mass, even more preferably 0.8% to 3.0% by mass, and still more preferably 1.0% to 3.0% by mass.

[0089] In this embodiment, the silicone compound (B) can be one or more silicone compounds selected from the group consisting of unmodified silicone (B1) and modified silicone (B2), without any particular limitations. Herein, from the viewpoint of making it easier to exhibit the effects of the present invention, it is preferable that the silicone compound (B) includes a modified silicone (B2), and that the modified silicone (B2) includes a side-chain modified silicone (B21) in which at least the side chains of the polysiloxane skeleton are modified. The following provides a detailed explanation of unmodified silicone (B1) and modified silicone (B2).

[0090] (Unmodified silicone (B1)) Unmodified silicone (B1) is a silicone compound in which all of the side chains and terminals of the polysiloxane skeleton are composed of alkyl groups, and no functional groups other than the alkyl groups are introduced into the side chains and terminals of the polysiloxane skeleton. As the unmodified silicone (B1), compounds represented by the following general formula (b1-1) are preferred. [ka]

[0091] In the above general formula (b1-1), R b1 and R b2 Each of these is an alkyl group having 1 to 10 carbon atoms. n is an integer greater than or equal to 1. b1 and R b2 The number of carbon atoms in the alkyl group that can be selected is preferably 1 to 6, more preferably 1 to 3, even more preferably 1 to 2, and most preferably 1. In the following explanation, R b1 These are called alkyl groups in the side chains of the polysiloxane skeleton, and R b2 We will refer to this as the terminal alkyl group of the polysiloxane skeleton.

[0092] Unmodified silicone (B1) may be a commercially available product. When using dimethyl silicone (polydimethylsiloxane) as the unmodified silicone (B1), commercially available products include, for example, the KF-96 series manufactured by Shin-Etsu Chemical Co., Ltd.

[0093] Unmodified silicone (B1) may be used alone or in combination of two or more types.

[0094] (Modified silicone (B2)) Modified silicone (B2) is a silicone compound in which at least one of the side chains and terminal portions of the polysiloxane skeleton in unmodified silicone (B1) has been modified. Furthermore, "at least one of the side chains and terminals of the polysiloxane skeleton has been modified" means that the alkyl group of the side chain of the polysiloxane skeleton (R in the general formula (b1-1) above) has been modified. b1 ) and terminal alkyl groups (R in the above general formula (b1-1) b2 This means that at least one of the alkyl groups is substituted with a functional group other than the alkyl group in question.

[0095] In this embodiment, the modified silicone (B2) may be one or more selected from side-chain modified modified silicones in which the side chains of the polysiloxane skeleton in the unmodified silicone (B1) are modified and the terminals remain unmodified; one or more selected from terminal modified modified silicones in which the terminals of the polysiloxane skeleton in the unmodified silicone (B1) are modified and the side chains remain unmodified; or one or more selected from side-chain terminal modified modified silicones in which both the side chains and terminals of the polysiloxane skeleton in the unmodified silicone (B1) are modified.

[0096] Examples of side-chain modified silicones include monoamine-modified silicones, diamine-modified silicones, special amino-modified silicones, epoxy-modified silicones, alicyclic epoxy-modified silicones, carbinol-modified silicones, mercapto-modified silicones, carboxyl-modified silicones, hydrogen-modified silicones, amino-polyether-modified silicones, epoxy-polyether-modified silicones, epoxy-aralkyl-modified silicones, polyether-modified silicones, aralkyl-modified silicones, fluoroalkyl-modified silicones, long-chain alkyl-modified silicones, higher fatty acid ester-modified silicones, higher fatty acid amide-modified silicones, polyether-long-chain alkyl-aralkyl-modified silicones, long-chain alkyl-aralkyl-modified silicones, and phenyl-modified silicones. These may be used individually or in combination of two or more types.

[0097] Examples of end-modified silicones include end-modified silicones such as amino-modified silicones, epoxy-modified silicones, alicyclic epoxy-modified silicones, carbinol-modified silicones, methacrylic-modified silicones, polyether-modified silicones, mercapto-modified silicones, carboxyl-modified silicones, phenol-modified silicones, silanol-modified silicones, acrylic-modified silicones, and carboxylic acid anhydride-modified silicones; and one-end modified silicones such as epoxy-modified silicones, carbinol-modified silicones, diol-modified silicones, methacrylic-modified silicones, and carboxyl-modified silicones.

[0098] Examples of side-chain terminal-modified silicones include side-chain amino-modified and terminally methoxy-modified silicones, and side-chain epoxy-modified and terminally epoxy-modified silicones.

[0099] In this embodiment, from the viewpoint of making it easier to improve the effects of the present invention, it is preferable that the modified silicone (B2) includes one or more types selected from side-chain modified modified silicones and side-chain terminal modified modified silicones. That is, it is preferable that the modified silicone (B2) includes a side-chain modified silicone (B21) in which at least the side chains of the polysiloxane skeleton in the unmodified silicone (B1) are modified.

[0100] From the viewpoint of making it easier to exhibit the effects of the present invention, the content of side-chain modified silicone (B21) in the modified silicone (B2) is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, even more preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, even more preferably 90% to 100% by mass, and even more preferably 95% to 100% by mass, based on the total amount (100% by mass) of the modified silicone (B2).

[0101] Furthermore, from the viewpoint of making it easier to exhibit the effects of the present invention, it is preferable that the side-chain modified silicone (B21) is a side-chain modified silicone (B21a) having one or more epoxy groups. Examples of side-chain modified silicones (B21a) having one or more epoxy groups include side-chain modified epoxy-modified silicones, side-chain modified alicyclic epoxy-modified silicones, side-chain modified epoxy / polyether-modified silicones, side-chain modified epoxy / aralkyl-modified silicones, and side-chain terminal modified side-chain epoxy-modified / double-terminal epoxy-modified silicones.

[0102] A commercially available side-chain modified silicone (B21a) having one or more epoxy groups may be used. Commercially available side-chain modified epoxy-modified silicones include X-22-343, KF-101, KF-1001, and X-22-2000 from Shin-Etsu Chemical Co., Ltd., and SF8411 Fluid and SF8413 Fluid from Dow Toray Industries, Inc. Commercially available side-chain modified alicyclic epoxy-modified silicones include X-22-2046 and KF-102 from Shin-Etsu Chemical Co., Ltd., and BY16-839 Fluid and L-9300 from Dow-Toray Industries, Inc. Commercially available side-chain modified epoxy / polyether modified silicones include X-22-4741 and KF-1002 from Shin-Etsu Chemical Co., Ltd., and BY16-876 and FZ-3736 Fluid from Dow Toray Industries, Inc. Examples of commercially available side-chain modified epoxy aralkyl-modified silicones include KF-1005 manufactured by Shin-Etsu Chemical Co., Ltd. Examples of commercially available side-chain terminal-modified side-chain epoxy-modified and double-ended epoxy-modified silicones include X-22-9002 manufactured by Shin-Etsu Chemical Co., Ltd.

[0103] Among these, from the viewpoint of availability and effectiveness, it is preferable that the side-chain modified silicone (B21a) having one or more epoxy groups is one or more selected from the group consisting of side-chain modified epoxy-modified silicones and side-chain modified alicyclic epoxy-modified silicones. From the viewpoint of making it easier to exhibit the effects of the present invention, the content of side-chain modified silicone (B21a) in the modified silicone (B2) is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, even more preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, even more preferably 90% to 100% by mass, and even more preferably 95% to 100% by mass, based on the total amount (100% by mass) of the modified silicone (B2).

[0104] Modified silicone (B2) may be used alone or in combination of two or more types.

[0105] (Content of unmodified silicone (B1) when modified silicone (B2) is included) In this embodiment, when the refrigeration oil composition contains modified silicone (B2), it is preferable that the content of unmodified silicone (B1) be low, from the viewpoint of making it easier to further improve the effects of the present invention. Specifically, the content of unmodified silicone (B1) is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 1 part by mass or less, per 100 parts by mass of modified silicone (B2).

[0106] <Acid scavenger (C)> The refrigeration oil composition of this embodiment may further contain an acid scavenger (C). Examples of acid scavengers (C) include epoxy compounds. However, in this specification, epoxy compounds having a polysiloxane skeleton are classified as silicone compounds (B). Examples of epoxy compounds include glycidyl ether compounds, cyclohexene oxides, and α-olefin oxides. Among these, glycidyl ether compounds are preferred from the viewpoint of making it easier to improve the effects of the present invention. Examples of glycidyl ether compounds include aliphatic mono- or polyhydric alcohols having typically 3 to 30 carbon atoms, preferably 4 to 24, and more preferably 6 to 16 carbon atoms, or glycidyl ethers derived from 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 a saturated aliphatic mono-alcohol is preferred. Furthermore, in the case of aliphatic polyhydric alcohols or aromatic compounds containing two or more hydroxyl groups, it is preferable that all hydroxyl groups are glycidyl etherified, from the viewpoint of maintaining the stability of the refrigeration oil composition and suppressing an increase in the hydroxyl value. Examples of glycidyl ether compounds include phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, and among these, glycidyl ethers derived from linear, branched, or cyclic saturated aliphatic monoalcohols having 6 to 16 carbon atoms (i.e., alkyl glycidyl ethers with alkyl groups having 6 to 16 carbon atoms) are particularly preferred. Examples of such glycidyl ethers include 2-ethylhexyl glycidyl ether, isononyl glycidyl ether, decyl glycidyl ether, lauryl glycidyl ether, and myristyl glycidyl ether, with 2-ethylhexyl glycidyl ether being the most preferred. By using alkyl glycidyl ethers such as 2-ethylhexyl glycidyl ether, it is possible to appropriately prevent an increase in the acid value of the refrigeration oil composition and to improve its oxidation stability at high temperatures.

[0107] The content of the acid scavenger (C) is preferably 0.1 to 10% by mass, based on the total amount of the refrigerant oil composition. By setting the content of the acid scavenger (C) to 0.1% by mass or more, acids in the refrigerant oil composition can be appropriately captured, effectively preventing an increase in the acid value of the refrigerant oil composition and making it easier to improve high-temperature stability. Alternatively, by setting it to 10% by mass or less, it is possible to achieve an effect commensurate with the content. Furthermore, the above content of the acid scavenger (C) is more preferably 0.4% by mass or more, and even more preferably 0.5% by mass or more. More preferably 5% by mass or less, even more preferably 4% by mass or less, and even more preferably 3% by mass or less. The upper and lower limits of these numerical ranges can be arbitrarily combined. Specifically, more preferably 0.4% by mass to 5% by mass, even 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 acid scavenger (C) may be used alone or two or more may be used in combination.

[0108] <Ratio of silicone compound (B) and acid scavenger (C) content> In the refrigeration oil composition of this embodiment, from the viewpoint of making it easier to exhibit the effects of the present invention, the content ratio of silicone compound (B) to acid scavenger (C) [(B) / (C)] is preferably 0.025 or more by mass, more preferably 0.030 or more, even more preferably 0.035 or more, even more preferably 0.040 or more, even more preferably 0.045 or more, even more preferably 0.050 or more, even more preferably 0.15 or more, even more preferably 0.25 or more, and even more preferably 0.50 or more. Also, it is preferably 2.5 or less, more preferably 2.0 or less, and even more preferably 1.6 or less. The upper and lower limits of these numerical ranges can be combined in any way. Specifically, preferably 0.025 to 2.5, more preferably 0.030 to 2.0, even more preferably 0.035 to 1.6, even more preferably 0.040 to 1.6, still more preferably 0.045 to 1.6, even more preferably 0.050 to 1.6, even more preferably 0.15 to 1.6, even more preferably 0.25 to 1.6, and even more preferably 0.50 to 1.6.

[0109] <Antioxidant (D)> The refrigeration oil composition of this embodiment may further contain an antioxidant (D). Preferably, the antioxidant (D) is one or more selected from the group consisting of phenolic antioxidants and amine antioxidants. Examples of phenolic antioxidants include 2,6-di-tert-butyl-p-cresol (DBPC), 2,6-di-tert-butyl-4-ethylphenol, and 2,2'-methylenebis(4-methyl-6-tert-butylphenol). Examples of amine-based antioxidants include phenyl-α-naphthylamine and N,N'-diphenyl-p-phenylenediamine. Among these, phenolic antioxidants are preferred, and among phenolic antioxidants, 2,6-di-tert-butyl-p-cresol (DBPC) is preferred. From the viewpoint of stability and antioxidant performance, the content of antioxidant (D) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more, based on the total amount (100% by mass) of the refrigerant oil composition. Furthermore, it is preferably 5% by mass or less, more preferably 3% by mass or less, and even more preferably 1% by mass or less. The upper and lower limits of these numerical ranges can be combined in any way. Specifically, they are preferably 0.01% to 5% by mass, more preferably 0.05% to 3% by mass, and even more preferably 0.1% to 1% by mass.

[0110] <Ratio of silicone compound (B) and antioxidant (D) content> In the refrigeration oil composition of this embodiment, from the viewpoint of making it easier to exhibit the effects of the present invention, the content ratio of silicone compound (B) to antioxidant (D) [(B) / (D)] is preferably 0.17 or more, more preferably 0.33 or more, even more preferably 1.0 or more, even more preferably 1.7 or more, and still more preferably 3.3 or more, in terms of mass ratio. Also, it is preferably 17 or less, more preferably 13 or less, and even more preferably 10 or less. The upper and lower limits of these numerical ranges can be combined in any way. Specifically, they are preferably 0.17 to 17, more preferably 0.33 to 3.3, even more preferably 1.0 to 10, even more preferably 1.7 to 10, and still more preferably 3.3 to 10.

[0111] <Other additives> The refrigeration oil composition of this embodiment may further contain other additives other than the above components (A), (B), (C), and (D), as long as they do not impair the effects of the present invention. Other additives include one or more selected from the group consisting of oxygen scavengers, copper deactivators, and viscosity index improvers. The total content of these additives is preferably 0% to 10% by mass, more preferably 0.01% to 5% by mass, and even more preferably 0.1% to 3% by mass, based on the total amount (100% by mass) of the refrigerant oil composition.

[0112] (Oxygen scavenger) Examples of oxygen scavengers include aliphatic unsaturated compounds and terpenes containing double bonds. The above aliphatic unsaturated compounds are preferably unsaturated hydrocarbons, specifically olefins; and polyenes such as dienes and trienes. As for olefins, α-olefins such as 1-tetradecene, 1-hexadecene, and 1-octadecene are preferred from the viewpoint of reactivity with oxygen. Other aliphatic unsaturated compounds besides those mentioned above include those with the molecular formula C, from the viewpoint of reactivity with oxygen. 20 H 30 Unsaturated aliphatic alcohols having a conjugated double bond, such as vitamin A ((2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohexe-1-yl)nonano-2,4,6,8-tetraen-1-ol), represented by O, are preferred. As for terpenes having a double bond, terpene hydrocarbons having a double bond are preferred, and from the viewpoint of reactivity with oxygen, 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-methylidendodeca-1,6,10-triene) is more preferred. The oxygen scavenger may be used alone or in combination of two or more types.

[0113] (copper deactivator) Examples of copper deactivators include N-[N,N'-dialkyl (alkyl group with 3 to 12 carbon atoms) aminomethyl]triazole. The copper deactivator may be used alone or in combination of two or more types.

[0114] (Viscosity index improver) Examples of viscosity index improvers include polymethacrylate, polyisobutylene, ethylene-propylene copolymer, and styrene-diene hydrogenated copolymer. Viscosity index improvers may be used individually or in combination of two or more types.

[0115] [Method for producing refrigerant oil composition] The method for producing the above-mentioned refrigeration oil composition is not particularly limited. For example, the method for producing the refrigeration oil composition of this embodiment is the following general formula (1) C x F y H z ...(1) A method for producing a refrigerant oil composition used in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the general formula (1) above, where x is an integer from 2 to 6, y is an integer from 1 to 11, and z is an integer from 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds. The process includes a step of mixing a base oil (A) with one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2). The method for producing a refrigerant oil composition is such that the amount of the silicone compound (B) blended is 0.05% by mass or more based on the total amount of the refrigerant oil composition. There are no particular restrictions on the method of mixing the above components, but one example is a method that includes a step of blending a silicone compound (B) with a base oil (A). The acid scavenger (C), antioxidant (D), and other additives may be blended with the base oil (A) at the same time as the silicone compound (B), or they may be blended separately. Each component may also be blended in the form of a solution (dispersion) by adding a diluent oil or the like. After blending each component, it is preferable to stir and disperse them uniformly by a known method.

[0116] [Physical properties of refrigeration oil compositions] In this embodiment, the physical properties of the refrigeration oil composition after the autoclave test described in the examples below are as follows.

[0117] <Acid value> The acid value of the refrigerant oil composition after the autoclave test described in the examples below is preferably 0.15 mg KOH / g or less, more preferably 0.10 mg KOH / g or less.

[0118] <Fluorine content> The amount of fluorine in the refrigerant oil composition after the autoclave test described in the examples below is preferably 15 ppm by mass or less, more preferably 10 ppm by mass or less, and even more preferably 7 ppm by mass or less, based on the total amount of the refrigerant oil composition.

[0119] [Mixed composition for refrigerators] The above-mentioned refrigeration oil composition is mixed with a refrigerant and used as a mixed composition for refrigeration systems. In other words, the mixed composition for the refrigeration unit contains the above-mentioned refrigeration oil composition and a refrigerant. The following explains refrigerants.

[0120] <Refrigerant> The refrigerant used in this embodiment is the following general formula (1) C x F y H z ...(1) The refrigerant contains one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the general formula (1) above, where x is an integer from 2 to 6, y is an integer from 1 to 11, and z is an integer from 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds.

[0121] The general formula (1) above represents the types and number of elements in the molecule, specifically representing unsaturated fluorinated hydrocarbon compounds with 2 to 6 carbon atoms. Unsaturated fluorinated hydrocarbon compounds with 2 to 6 carbon atoms possess the physical and chemical properties, such as boiling point, freezing point, and latent heat of vaporization, required for use as a refrigerant. In the above general formula (1), C xThe bonding configuration of the x carbon atoms represented by can be a single carbon-carbon bond, a carbon-carbon double bond, or other unsaturated bonds. From the viewpoint of stability, a carbon-carbon double bond is preferred, and an unsaturated fluorinated hydrocarbon compound has one or more unsaturated bonds such as a carbon-carbon double bond in its molecule, preferably one in number. That is, C x It is more preferable that at least one of the bond configurations of the x carbon atoms represented by is a carbon-carbon double bond.

[0122] Preferred unsaturated fluorinated hydrocarbon compounds include, for example, fluorides of linear or branched chain olefins having 2 to 6 carbon atoms or cyclic olefins having 4 to 6 carbon atoms. Specifically, examples include ethylene fluoride with 1 to 3 fluorine atoms, propene fluoride with 1 to 5 fluorine atoms, butene fluoride with 1 to 7 fluorine atoms, pentene fluoride with 1 to 9 fluorine atoms, hexene fluoride with 1 to 11 fluorine atoms, cyclobutene fluoride with 1 to 5 fluorine atoms, cyclopentene fluoride with 1 to 7 fluorine atoms, and cyclohexene fluoride with 1 to 9 fluorine atoms. Among these, propene fluorides 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, with 2,3,3,3-tetrafluoropropene (R1234yf) being more preferred. The above unsaturated fluorinated hydrocarbon compounds may be used individually or in combination of two or more. Therefore, only one compound selected from 1,3,3,3-tetrafluoropropene (R1234ze), 2,3,3,3-tetrafluoropropene (R1234yf), and 1,2,3,3-tetrafluoropropene (R1234ye) may be used individually.

[0123] (Other refrigerants) In this embodiment, the refrigerant may be a mixed refrigerant that, in addition to the unsaturated fluorinated hydrocarbon compound shown in the general formula (1) above, optionally contains other compounds, for example, a saturated fluorinated hydrocarbon compound. The saturated fluorinated hydrocarbon compound is preferably a fluoride of an alkane having 1 to 4 carbon atoms, more preferably a fluoride of an alkane having 1 to 3 carbon atoms, and even more preferably a fluoride of an alkane (methane or ethane) having 1 or 2 carbon atoms. Examples of methane or ethane fluorides 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), and 1,1,1,2,2-pentafluoroethane (R125), among others, with difluoromethane and 1,1,1,2,2-pentafluoroethane being preferred. These saturated fluorinated hydrocarbon compounds may be used individually or in combination of two or more.

[0124] Furthermore, the refrigerant may include naturally occurring refrigerants. Examples of naturally occurring refrigerants include hydrocarbon refrigerants (HC), carbon dioxide (CO2, carbon dioxide gas), and ammonia. These naturally occurring refrigerants may be used individually or in combination of two or more types. The hydrocarbon refrigerant is preferably a hydrocarbon having 1 to 8 carbon atoms, more preferably a hydrocarbon having 1 to 5 carbon atoms, and even 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, making it preferable as a refrigerant. The hydrocarbon refrigerant is 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, cyclopentaneisobutane, and n-hexane. One of these may be used alone, or two or more may be used in combination.

[0125] (Content of unsaturated fluorinated hydrocarbon compounds in the refrigerant) In this embodiment, the refrigerant includes an unsaturated fluorinated hydrocarbon compound represented by the general formula (1) above. The content of the unsaturated fluorinated hydrocarbon compound represented by the above general formula (1) is preferably 50% to 100% by mass, more preferably 60% to 100% by mass, even more preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, even more preferably 90% to 100% by mass, and even more preferably 100% by mass, based on the total amount of the refrigerant. The refrigeration oil composition of this embodiment exhibits excellent suppression of acid value increase even with refrigerants containing a high amount of unsaturated fluorinated hydrocarbon compounds.

[0126] (Amount of refrigerant and refrigerant oil composition used) In the mixed composition for refrigeration according to this embodiment, the amounts of refrigerant and refrigerant oil composition used are, in terms of the mass ratio of the refrigerant oil composition to the refrigerant [(refrigerant oil composition) / (refrigerant)], preferably 1 / 99 to 90 / 10, and more preferably 5 / 95 to 70 / 30. By keeping the mass ratio of the refrigerant oil composition to the refrigerant within this range, suitable lubricity and refrigeration capacity in the refrigeration unit can be obtained.

[0127] [Uses of refrigerant oil compositions and mixed compositions for refrigeration] The above-mentioned refrigeration oil composition and refrigeration mixture composition are preferably used in, for example, air conditioners, refrigerators, vending machines, display cases, refrigeration systems, hot water supply systems, or heating systems. Examples of air conditioners include open-type car air conditioners, electric car air conditioners, and other car air conditioners; gas heat pump (GHP) air conditioners; and the like.

[0128] [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) A refrigerant oil composition for use in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the general formula (1) above, where x is an integer from 2 to 6, y is an integer from 1 to 11, and z is an integer from 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds. It contains a base oil (A) and one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2), A refrigerant oil composition in which the content of the silicone compound (B) is 0.05% by mass or more on a total basis of the refrigerant oil composition. [2] The silicone compound (B) comprises the modified silicone (B2), The refrigeration oil composition according to [1] above, wherein the modified silicone (B2) comprises a side-chain modified silicone (B21) in which at least the side chains of the polysiloxane skeleton are modified. [3] The refrigeration oil composition according to [2] above, wherein the side-chain modified silicone (B21) is a side-chain modified silicone (B21a) having one or more epoxy groups. [4] A refrigeration oil composition according to any one of [1] to [3] above, further comprising an acid scavenger (C). [5] The refrigeration oil composition according to [4] above, wherein the content ratio of the silicone compound (B) to the acid scavenger (C) [(B) / (C)] is 0.025 or more by mass ratio. [6] The refrigeration oil composition according to any one of [1] to [5] above, further comprising an antioxidant (D). [7] The refrigeration oil composition according to [6] above, wherein the content ratio of the silicone compound (B) to the antioxidant (D) [(B) / (D)] is 0.17 or more by mass. [8] The refrigeration oil composition according to any one of [1] to [7] above, wherein the base oil (A) comprises one or more selected from the group consisting of polyalkylene glycols, polyvinyl ethers, poly(oxy)alkylene glycol or copolymers of the monoether thereof with polyvinyl ether, and polyol esters. [9] The refrigeration oil composition according to any one of [1] to [8] above, wherein the unsaturated fluorinated hydrocarbon compound comprises one or more selected from the group consisting of R1234ze, R1234yf, and R1234ye.

[10] The following general formula (1) C x F y H z ...(1) A mixed composition for a refrigerator comprising a refrigerant containing one or more compounds selected from those represented by the general formula (1) above, where x is an integer from 2 to 6, y is an integer from 1 to 11, and z is an integer from 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds; and a refrigerant oil composition according to any of the above [1] to [9].

[11] The following general formula (1) C x F y H z ...(1) A method for producing a refrigerant oil composition used in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the general formula (1) above, where x is an integer from 2 to 6, y is an integer from 1 to 11, and z is an integer from 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds. The process includes a step of mixing a base oil (A) with one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2). A method for producing a refrigerant oil composition, wherein the amount of the silicone compound (B) blended is 0.05% by mass or more based on the total amount of the refrigerant oil composition. [Examples]

[0129] The present invention will be specifically described by the following embodiments. However, the present invention is not limited to the following embodiments.

[0130] [Methods for measuring various physical properties] The properties of each raw material used in each example and comparative example, as well as the properties of each refrigeration oil composition in each example and comparative example, were measured according to the following procedure. (1)Kinematic viscosity at 100℃ The kinematic viscosity of base oil (A) at 100°C was measured in accordance with JIS K2283:2000. (2) Hydroxyl value The base oil (A) was measured by neutralization titration 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) instrument. For GPC, two TSKgel SuperMultiporeHZ-M columns manufactured by Tosoh Corporation were sequentially linked together, tetrahydrofuran was used as the eluent, and a refractive index detector (RI detector) was used for the measurement. Polystyrene was used as the standard sample to determine the number-average molecular weight (Mn).

[0131] [Details of each component used in the preparation of the refrigeration oil composition] Details of each component used in the preparation of the refrigeration oil composition are shown below.

[0132] <Base oil (A)> (Base oil (A-1)) • "PAG": Polyoxypropylene glycol dimethyl ether (compound represented by the general formula (A-1-i) above), kinematic viscosity at 100°C = 9.5 mm² 2 / s, hydroxyl value = 6 mg KOH / g, number average molecular weight = 1,100 (Base oil (A-2)) • "PVE": Polyvinyl ether (in the above general formula (A-2), R 1a , R 2a , and R 3a This is a hydrogen atom, and r=0, R 5a It is a C2-C4 hydrocarbon group. ), kinematic viscosity at 100°C = 8.3 mm² 2 / s, hydroxyl value = 4 mg KOH / g, number average molecular weight = 1,200

[0133] <Silicone compound (B)> (Unmodified silicone (B1)) • "Dimethyl silicone": KF-96H-12500cs (manufactured by Shin-Etsu Chemical Co., Ltd.) (Modified silicone (B2)) The following side-chain modified silicone (B21) was used. · "Epoxy-modified silicone 1": X-22-2000 (manufactured by Shin-Etsu Chemical Co., Ltd.), an epoxy-modified silicone having a phenyl group in the side chain. · "Epoxy-modified silicone 2": KF-101 (manufactured by Shin-Etsu Chemical Co., Ltd.) · "Cycloaliphatic epoxy-modified silicone": KF-102 (manufactured by Shin-Etsu Chemical Co., Ltd.) · "Aralkyl-modified silicone": KF-410 (manufactured by Shin-Etsu Chemical Co., Ltd.) · "Polyether-modified silicone 1": KF-945 (manufactured by Shin-Etsu Chemical Co., Ltd.), HLB value = 4. · "Polyether-modified silicone 2": KF-6015 (manufactured by Shin-Etsu Chemical Co., Ltd.), HLB value = 5. Note that "epoxy-modified silicone 1", "epoxy-modified silicone 2", and "cycloaliphatic epoxy-modified silicone" are modified silicones corresponding to side-chain modified silicone (B21a) having one or more epoxy groups.

[0134] <Acid scavenger (C)> As the acid scavenger (C), 2-ethylhexyl glycidyl ether was used.

[0135] (4) Antioxidant (D) As the antioxidant (D), di-tert-butyl-p-cresol (DBPC) was used.

[0136] [Examples 1 to 17, Comparative Examples 1 to 5] The above components were mixed to prepare a refrigerant oil composition having the composition shown in Table 1, and an autoclave test described below was conducted. Note that the numerical unit of the blending composition in Table 1 is "mass%". Also, the content of the silicone compound (B) in Table 1 means the content in terms of solid content.

[0137] <Autoclave test> The procedure was carried out in accordance with Annex C of JIS K2211:2009. Specifically, a refrigeration mixed composition (water content 2,000 ppm) made by mixing 30 g of the refrigeration oil compositions of Examples 1-17 and Comparative Examples 1-5 with 30 g of R1234yf, along with a metal catalyst consisting of iron, copper, and aluminum, was sealed in a 200 mL autoclave. Subsequently, after vacuuming, the autoclave was maintained at a temperature of 175°C for 336 hours, and then the acid value and fluorine content of the refrigeration oil composition were evaluated using the method described below.

[0138] (Evaluation of the acid value of refrigeration oil compositions) Measurements were taken in accordance with JIS K2501:2003, using indicator photometric titration (see Annex 1 of the JIS standard). The evaluation criteria were as follows, with grades A and B being considered passing grades. • Rating A: 0.10 mg KOH / g or less • Rating B: Greater than 0.10 mg KOH / g, and less than or equal to 0.15 mg KOH / g • Rating C: Over 0.15 mg KOH / g

[0139] (Evaluation of fluorine content in refrigerant oil composition) The amount of fluorine in the refrigeration oil composition is determined by separating the refrigerant from the refrigeration mixed composition after autoclave testing and determining the amount of fluorine ions (F) in the refrigeration oil composition in accordance with JIS K 0127:2013 (General rules for ion chromatography analysis). - ) was detected and measured. The evaluation criteria were as follows, with grades A and B being considered passing grades. • Rating A: Less than 10 ppm by mass • Rating B: Over 10 ppm by mass, 15 ppm or less by mass • Rating C: Over 15 ppm by mass

[0140] [Table 1]

[0141] From Table 1, the following can be seen. The refrigerant oil compositions of Examples 1 to 17, which contain 0.05% by mass or more of silicone compound (B), exhibit excellent suppression of the increase in the acid value of the refrigerant oil composition after autoclave testing, and also show a low amount of fluorine in the refrigerant oil composition after testing. In particular, the refrigeration oil compositions of Examples 2-15 and 17, which contain 0.05% by mass or more of modified silicone (B2) (side-chain modified silicone (B21)), are extremely effective in suppressing the increase in the acid value of the refrigeration oil composition after autoclave testing, and it can be seen that the amount of fluorine in the refrigeration oil composition after testing is also extremely low. In contrast, the refrigerant oil compositions of Comparative Examples 1 to 5, which do not contain silicone compound (B), show insufficient suppression of 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 high. From the above results, it can be seen that the silicone compound (B) released fluorine (F) into the refrigerant oil composition due to the decomposition of the refrigerant. - ) captures fluorine (F) in the refrigeration oil composition. - It is presumed that this action of reducing the amount of acid suppresses the rise in the acid value of the refrigeration oil composition.

Claims

1. The following general formula (1) C ｘ F ｙ H ｚ ・・・(1) A refrigerant oil composition for use in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the general formula (1) above: [wherein x is an integer from 2 to 6, y is an integer from 1 to 11, and z is an integer from 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds.] It contains a base oil (A), one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2), and an acid scavenger (C). The base oil (A) is one or more selected from the group consisting of polyalkylene glycols and polyvinyl ethers. The silicone compound (B) comprises the modified silicone (B2), The modified silicone (B2) includes a side-chain modified silicone (B21) in which at least the side chains of the polysiloxane skeleton are modified. The side-chain modified silicone (B21) is a side-chain modified silicone (B21a) having one or more epoxy groups. The content of the silicone compound (B) is 0.05% by mass or more on a total basis of the refrigerant oil composition. The acid scavenger (C) is a glycidyl ether compound in the refrigeration oil composition.

2. The refrigeration oil composition according to claim 1, wherein the content ratio of the silicone compound (B) to the acid scavenger (C) [(B) / (C)] is 0.025 or more by mass.

3. Furthermore, the refrigeration oil composition according to claim 1 or 2 contains an antioxidant (D).

4. The refrigeration oil composition according to claim 3, wherein the content ratio of the silicone compound (B) to the antioxidant (D) [(B) / (D)] is 0.17 or more by mass.

5. The refrigeration oil composition according to any one of claims 1 to 4, wherein the unsaturated fluorinated hydrocarbon compound comprises one or more selected from the group consisting of R1234ze, R1234yf, and R1234ye.

6. The following general formula (1) C ｘ F ｙ H ｚ ・・・(1) A refrigerant comprising one or more compounds selected from those represented by the general formula (1) [wherein x is an integer from 2 to 6, y is an integer from 1 to 11, and z is an integer from 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds], and a refrigerant oil composition according to any one of claims 1 to 5.

7. The following general formula (1) C ｘ F ｙ H ｚ ・・・(1) A method for producing a refrigerant oil composition used in a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the general formula (1) above, where x is an integer from 2 to 6, y is an integer from 1 to 11, and z is an integer from 1 to 11, and the molecule has one or more carbon-carbon unsaturated bonds. The process includes mixing a base oil (A), one or more silicone compounds (B) selected from the group consisting of unmodified silicone (B1) and modified silicone (B2), and an acid scavenger (C). The base oil (A) is one or more selected from the group consisting of polyalkylene glycols and polyvinyl ethers. The silicone compound (B) comprises the modified silicone (B2), The modified silicone (B2) includes a side-chain modified silicone (B21) in which at least the side chains of the polysiloxane skeleton are modified. The side-chain modified silicone (B21) is a side-chain modified silicone (B21a) having one or more epoxy groups. The amount of the silicone compound (B) blended is 0.05% by mass or more based on the total amount of the refrigerant oil composition. The method for producing a refrigeration oil composition, wherein the acid scavenger (C) is a glycidyl ether compound.

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