JP2014198854A - Refrigeration oil and hydraulic fluid composition for refrigerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigeration oil and a hydraulic fluid composition for a refrigerator capable of achieving both of refrigerant compatibility and thermal and chemical stability at high level in a refrigeration system using a fluoropropene refrigerant.SOLUTION: The refrigeration oil contains ester obtained by using following compounds (a) to (c): (a) a compound having two or more hydroxyl groups or a derivative thereof, (b) a compound having two or more carboxyl groups or a derivative thereof, and (c) a compound having a carboxyl group or a derivative thereof and/or a compound having a hydroxyl group or a derivative thereof. The flow point of the ester is -10°C or less and it is used with a fluoropropene refrigerant. The hydraulic fluid composition for a refrigerator contains ester obtained by using above compounds (a) to (c) and the fluoropropene refrigerant, and the flow point of the ester is -10°C or less.

Description

  The present invention relates to a refrigerator oil and a working fluid composition for a refrigerator.

  Due to the problem of ozone layer destruction in recent years, CFC (chlorofluorocarbon) and HCFC (hydrochlorofluorocarbon), which have been used as refrigerants in conventional refrigeration equipment, are subject to regulation, and HFC (hydrofluorocarbon) is used as a refrigerant instead. It is being done.

  When CFC or HCFC is used as a refrigerant, mineral oil or hydrocarbon oil such as alkylbenzene has been suitably used as the refrigeration oil. However, when the refrigerant is changed, the refrigeration oil used in the coexistence is compatible with the refrigerant, Refrigerating machine oil needs to be developed for each refrigerant in order to exhibit unpredictable behaviors such as lubricity, melt viscosity with refrigerant, and thermal and chemical stability. Therefore, as a refrigerating machine oil for HFC refrigerant, for example, polyalkylene glycol (see Patent Document 1), ester (see Patent Document 2), carbonate (see Patent Document 3), polyvinyl ether (see Patent Document 4) Etc. are being developed.

  Among HFC refrigerants, HFC-134a, which is standardly used as a refrigerant for car air conditioners, has zero ozone depletion potential (ODP), but has a high global warming potential (GWP). ing. Therefore, there is an urgent need to develop a refrigerant that replaces HFC-134a.

  Under such a background, as an alternative to HFC-134a, whether both ODP and GWP are very small, nonflammable, and thermodynamic properties that are a measure of refrigerant performance are almost equivalent to HFC-134a More than that, the use of refrigerants of fluoropropenes has been proposed. Furthermore, the use of a mixed refrigerant of fluoropropene and saturated hydrofluorocarbon, saturated hydrocarbon having 3 to 5 carbon atoms, dimethyl ether, carbon dioxide, bis (trifluoromethyl) sulfide or trifluoroiodomethane is also proposed ( (See Patent Document 5).

  Also usable with fluoropropene refrigerant or mixed refrigerant of fluoropropene and saturated hydrofluorocarbon, saturated hydrocarbon having 3 to 5 carbon atoms, dimethyl ether, carbon dioxide, bis (trifluoromethyl) sulfide or trifluoroiodomethane. Refrigerating machine oils include mineral oils, alkylbenzenes, polyalphaolefins, polyalkylene glycols, monoesters, diesters, polyol esters, phthalate esters, alkyl ethers, ketones, carbonate esters, and polyvinyl ethers. Refrigerating machine oil using the above has been proposed (see Patent Documents 5 to 7).

Japanese Patent Laid-Open No. 02-242888 Japanese Patent Laid-Open No. 03-200895 Japanese Patent Laid-Open No. 03-217495 Japanese Patent Laid-Open No. 06-128578 International Publication WO2006 / 094303 Pamphlet JP-T-2006-512426 International Publication WO2005 / 103190 Pamphlet

  As described in Patent Documents 5, 6, and 7, in a refrigeration system using a fluoropropene refrigerant, mineral oil used in CFC and HCFC, hydrocarbons such as alkylbenzene, and polyphenol used in HFC. It is considered that any refrigerating machine oil such as alkylene glycol, polyol ester, and polyvinyl ether is applicable. However, according to the study by the present inventors, refrigerant compatibility cannot be achieved at a high level simply by diverting these conventional refrigeration oils as they are to the system.

  The present invention has been made in view of such circumstances, and in a refrigerating system using a fluoropropene refrigerant, a refrigerating machine oil and a working fluid composition for a refrigerating machine that can achieve refrigerant compatibility at a high level. The purpose is to provide.

  As a result of intensive studies to achieve the above object, the present inventors have found that by using a specific ester, a refrigerating machine oil having sufficient compatibility with a refrigerant can be realized in the presence of a fluoropropene refrigerant. The present invention has been completed.

That is, the present invention provides the following compounds (a) to (c):
(A) a compound having two or more hydroxyl groups or a derivative thereof,
(B) a compound having two or more carboxyl groups or a derivative thereof; and (c) a compound having one carboxyl group or a derivative thereof and / or a compound having one hydroxyl group or a derivative thereof; A working fluid composition for a refrigerator, comprising a propene refrigerant and having an ester pour point of −10 ° C. or lower.

  Moreover, this invention contains ester obtained using said compound (a)-(c), The pour point of ester is -10 degrees C or less, The refrigerating machine oil characterized by being used with a fluoropropene refrigerant | coolant I will provide a.

  The working fluid composition for a refrigerator of the present invention includes 1,2,3,3,3-pentafluoropropene (HFC-1225ye), 1,3,3,3-tetrafluoropropene (HFC-) as a fluoropropene refrigerant. 1234ze), 2,3,3,3-tetrafluoropropene (HFC-1234yf), 1,2,3,3-tetrafluoropropene (HFC1234ye) and 3,3,3-trifluoropropene (HFC-1243zf) It is preferable to contain at least one selected.

  Moreover, the working fluid composition for a refrigerator of the present invention may use at least one fluoropropene refrigerant (hereinafter referred to as “refrigerant (A)”) alone, saturated hydrofluorocarbon, 3 to 5 carbon atoms. And at least one selected from hydrocarbons, dimethyl ether, carbon dioxide, bis (trifluoromethyl) sulfide, and trifluoroiodomethane refrigerant (hereinafter referred to as “refrigerant (B)”). .

Furthermore, in the mixed refrigerant of the refrigerant (A) and the refrigerant (B), 1,2,3,3,3-pentafluoropropene (HFC-1225ye), 1,3,3,3- Tetrafluoropropene (HFC-1234ze), 2,3,3,3-tetrafluoropropene (HFC-1234yf), 1,2,3,3-tetrafluoropropene (HFC1234ye) and 3,3,3-trifluoropropene At least one selected from (HFC-1243zf) is preferred;
Examples of saturated hydrofluorocarbons include difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoro. Ethane (HFC-134a), 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1 1,1,1,2,3,3-hexafluoropropane (HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1,1,1,3,3 A small amount selected from pentafluoropropane (HFC-245fa) and 1,1,1,3,3-pentafluorobutane (HFC-365mfc) Kutomo one is preferred;
The hydrocarbon having 3 to 5 carbon atoms is preferably at least one selected from propane, normal butane, isobutane, 2-methylbutane and normal pentane.

  As described above, according to the present invention, it is possible to provide a refrigerating machine oil and a working fluid composition for a refrigerating machine that can achieve refrigerant compatibility at a high level.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

The refrigerating machine oil of the present invention includes the following compounds (a) to (c):
(A) a compound having two or more hydroxyl groups or a derivative thereof,
(B) a compound having two or more carboxyl groups or a derivative thereof, and (c) a compound having one carboxyl group or a derivative thereof and / or an ester obtained using a compound having one hydroxyl group or a derivative thereof (hereinafter, Also referred to as "ester according to the present invention"),
It is characterized by being used with fluoropropene refrigerant. A decrease in refrigeration efficiency can be sufficiently prevented. In addition, the working fluid composition for a refrigerator according to the present invention is characterized by containing an ester obtained by using the compounds (a) to (c) and a fluoropropene refrigerant. Here, the working fluid composition for a refrigerator of the present invention includes an embodiment containing the refrigerator oil of the present invention and a fluoropropene refrigerant.

  The compound (a) constituting the ester according to the present invention is a compound having two or more hydroxyl groups or a derivative thereof. The number of hydroxyl groups is preferably 2 to 6 from the viewpoint of securing an appropriate viscosity and compatibility with the fluoropropene refrigerant. In addition, if only a compound having one hydroxyl group or a derivative thereof is used as the alcohol component, sufficient viscosity cannot be obtained in the resulting ester, and poor lubrication and reduced refrigeration efficiency are likely to occur. Thermal / chemical stability and low temperature The fluidity becomes insufficient.

  Specific examples of the compound (a) include polyhydric alcohols, polyhydric phenols, polyhydric amino alcohols and condensates thereof, and compounds obtained by esterifying hydroxyl groups of these compounds with a carboxylic acid such as acetic acid. Among them, it is preferable to use a polyhydric alcohol or a condensate thereof or a derivative thereof because refrigerant compatibility, electrical insulation and thermal stability tend to be further improved.

  The number of carbon atoms of the polyhydric alcohol is not particularly limited, but a polyhydric alcohol having 2 to 12 carbon atoms is preferably used. As such polyhydric alcohols, specific examples of the dihydric alcohol (diol) include ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, and 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, Examples include 1,11-undecanediol and 1,12-dodecanediol. Specific examples of trihydric or higher alcohols include trimethylolethane, trimethylolpropane, trimethylolbutane, di- (trimethylolpropane), tri- (trimethylolpropane), pentaerythritol, di- ( Pentaerythritol), tri- (pentaerythritol), glycerin, polyglycerol (glycerin 2-3 trimer), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol glycerol condensate, adonitol, arabitol, xylitol, mannitol Polysaccharides such as xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, and partial etherified products thereof It is. Among these, hindered alcohols such as neopentyl glycol, trimethylol ethane, trimethylol propane, trimethylol butane, di- (trimethylol propane), tri- (trimethylol propane), pentaerythritol, di- (pentaerythritol), etc. Is preferred.

  In the present invention, as described above, the compound (a) having a hydroxyl group esterified with a carboxylic acid can be used. As such a derivative, a compound in which a hydroxyl group is esterified with a lower carboxylic acid is preferable, and specifically, an acetate ester or a propionate ester of the compound exemplified in the above description of the polyhydric alcohol is preferably used.

  The compound (b) constituting the ester according to the present invention is a compound having two or more carboxyl groups or a derivative thereof. The number of carboxyl groups is preferably 2-6. If only a compound having one carboxyl group or a derivative thereof is used as the acid component, the resulting ester will have insufficient viscosity, which may cause poor lubrication and reduced refrigeration efficiency, thermal / chemical stability, and low-temperature flow. The property becomes insufficient.

  Specific examples of the compound (b) include divalent to hexavalent carboxylic acids, and carboxylic acid derivatives such as acid anhydrides, esters, and acid halides thereof.

  The carbon number of the divalent to tetravalent carboxylic acid is not particularly limited, but divalent carboxylic acids having 2 to 10 carbon atoms are preferably used. Specific examples of such divalent to hexavalent carboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, methylmalonic acid, and ethylmalon. Acid, dimethyl malonic acid, methyl succinic acid, 2,2-dimethyl succinic acid, 2,3-dimethyl succinic acid, 2-ethyl-2-methyl succinic acid, 2-methyl glutaric acid, 3-methyl glutaric acid, 3-methyl adipine Saturated aliphatic dicarboxylic acids such as acids; unsaturated aliphatic dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid, and mesaconic acid; 1,2-cyclohexanedicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid Alicyclic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, etc. Carboxylic acid, and the like, also preferably a divalent carboxylic acid Among these, further, saturated aliphatic dicarboxylic acids from the viewpoint of oxidation stability are more preferable.

  In the present invention, as described above, a derivative of a compound having two carboxyl groups can be used as the compound (b). Such derivatives include esters, acid anhydrides, acid halides, etc. Among them, esters of the above divalent carboxylic acids and lower alcohols (more preferably methanol or ethanol) are preferably used.

  The compound (c) constituting the ester according to the present invention is a compound having one carboxyl group or a derivative thereof and / or a compound having one hydroxyl group or a derivative thereof. In the present invention, as the compound (c), any one of a compound having one carboxyl group or a derivative thereof and a compound having one hydroxyl group or a derivative thereof may be used alone, or a mixture of both. It may be used as If only a compound having two or more carboxyl groups or a derivative thereof is used as the acid component and only a compound having two or more hydroxyl groups or a derivative thereof is used as the alcohol component, the thermal / chemical stability is poor. It will be enough.

  Specific examples of the compound having one carboxyl group or a derivative thereof according to the present invention include monovalent fatty acids and acid anhydrides, esters and acid halides thereof. The number of carbon atoms of the monovalent fatty acid is not particularly limited, and those having 1 to 24 carbon atoms are usually used, but the number of carbon atoms of the monovalent fatty acid is preferably 3 or more, more preferably 4 or more. 5 or more is more preferable, and 8 or more is particularly preferable. When the number of carbon atoms of the monovalent fatty acid is less than 3, the resulting ester inherently has insufficient lubricity, becomes excessively compatible with the fluoropropene refrigerant, and is diluted with the refrigerant to reduce the viscosity. It tends to decrease, resulting in a decrease in refrigeration efficiency and poor lubrication due to a decrease in sealing performance.

  Further, the carbon number of the monovalent fatty acid is preferably 22 or less, more preferably 20 or less, and further preferably 18 or less. When the number of carbon atoms of the monovalent fatty acid exceeds 22, the compatibility between the resulting ester and the fluoropropene refrigerant becomes insufficient, and the lubrication of the compressor due to a decrease in oil return and the tendency to decrease the refrigeration efficiency tend to occur. is there.

  The monovalent fatty acid as the compound (c) may be either linear or branched, but is preferably a linear monovalent fatty acid from the viewpoint of lubricity, and is stable in heat and hydrolysis. From the viewpoint of properties, branched chain monovalent fatty acids are preferred. The monovalent fatty acid may be either a saturated fatty acid or an unsaturated fatty acid.

  Specific examples of the monovalent fatty acid as the compound (c) according to the present invention include pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, and tetradecanoic acid. , Pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, icosanoic acid, oleic acid and the like, or those in which the α carbon atom is a quaternary carbon atom (neoic acid), etc. Among these, 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), lauric acid (n-dodecanoic acid), myristic acid (n-tetradecanoic acid), palmitic acid (n-hexadede) Acid), stearic acid (n-octadecanoic 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 is preferably used.

  Specific examples of the compound having one hydroxyl group or a derivative thereof according to the present invention include monohydric alcohol, monohydric phenol, monohydric amino alcohol, and the hydroxyl group of these compounds is esterified with carboxylic acid such as acetic acid. And the like. The number of carbon atoms of these compounds is not particularly limited, but those having 1 to 24 carbon atoms are preferred from the viewpoint that both lubricity and refrigerant compatibility are further improved in the resulting ester, and among them, those having 3 to 18 carbon atoms. A linear monohydric alcohol, a branched monohydric alcohol having 3 to 18 carbon atoms, and a monovalent cycloalcohol having 5 to 10 carbon atoms are preferable.

  Specific examples of the monohydric alcohol having a carbon number within the above preferred range include linear or branched propanol (including n-propanol, 1-methylethanol, etc.), linear or branched. Butanol (including n-butanol, 1-methylpropanol, 2-methylpropanol, etc.), linear or branched pentanol (n-pentanol, 1-methylbutanol, 2-methylbutanol, 3-methyl Butanol, etc.), linear or branched hexanol (including n-hexanol, 1-methylpentanol, 2-methylpentanol, 3-methylpentanol, etc.), linear or branched Heptanol (n-heptanol, 1-methylhexanol, 2-methylhexanol, 3-methylhexanol, 4-methylhexanol, 5-methyl Hexanol, 2,4-dimethylpentanol, etc.), linear or branched octanol (including n-octanol, 2-ethylhexanol, 1-methylheptanol, 2-methylheptanol, etc.), straight Linear or branched nonanol (including n-nonanol, 1-methyloctanol, 3,5,5-trimethylhexanol, 1- (2′-methylpropyl) -3-methylbutanol, etc.), linear or Branched decanol (including n-decanol, iso-decanol, etc.), linear or branched undecanol (including n-undecanol, iso-undecanol, etc.), linear or branched dodecanol (including n-dodecanol, iso-dodecanol, etc.), linear or branched tridecanol (n-tridecanol, iso-to) Decanol etc.), linear or branched tetradecanol (including n-tetradecanol, iso-tetradecanol, etc.), linear or branched pentadecanol (n-pentadecane) And straight-chain or branched hexadecanol (including n-hexadecanol, iso-hexadecanol, etc.), straight-chain or branched heptadecane. Nord (including n-heptadecanol, iso-heptadecanol, etc.), linear or branched octadecanol (including n-octadecanol, iso-octadecanol, etc.), cyclohexanol, methyl Examples include cyclohexanol and dimethylcyclohexanol.

  In the present invention, a derivative in which a hydroxyl group is esterified with a carboxylic acid can also be used as the compound (c). As such derivatives, acetates, propionates and the like of the compounds exemplified in the description of the monohydric alcohol are preferably used.

Among the esters according to the present invention, the following compounds (a ′), (b ′) and (c ′):
(A ′) at least one selected from the group consisting of ethylene glycol, propylene glycol, butylene glycol, glycerin, neopentyl glycol, diethylene glycol, dipropylene glycol, dibutylene glycol and dibutylene glycol;
(B ′) at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and (c ′) valeric acid, capron Acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, 3,5,5-trimethylhexanoic acid, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, n-undecanol, n-dodecanol, n-tridecanol , N-tetradecanol, n-pentadecanol, n-hexadecanol, n-hept Decanol, n-octadecanol, iso-butanol, iso-pentanol, iso-hexanol, iso-heptanol, 2-ethylhexanol, 3,5,5-trimethylhexanol, iso-decanol, iso-dodecanol, iso-tetra An ester obtained by using at least one selected from the group consisting of decanol and iso-hexadecanol is particularly preferred. When the ester obtained by using the above compounds (a ′) to (c ′) is contained in the refrigerating machine oil, the lubricity, sealability, refrigerant compatibility, thermal / chemical stability, electrical insulation and the like are more balanced. There is a tendency to be satisfied.

In the present invention, the composition ratio of the compounds (a) to (c) is not particularly limited, but the lubricity, sealability, refrigerant compatibility, thermal / chemical stability, electrical insulation, etc. are satisfied at a higher level and in a well-balanced manner. Therefore, it is preferable to be within the ranges shown below based on the total amount of the compounds (a) to (c).
Compound (a): 3-55 mol%, preferably 5-50 mol%, more preferably 10-45 mol%
Compound (b): 3 to 55 mol%, preferably 5 to 50 mol%, more preferably 10 to 45 mol%
Compound (c): 3-90 mol%, preferably 5-80 mol%, more preferably 10-70 mol%.

  The ester according to the present invention is esterified by heating the compounds (a) to (c) according to a conventional method, preferably in an inert gas atmosphere such as nitrogen, in the presence of an esterification catalyst or in the absence of a catalyst. It is prepared by.

  In addition, when an alcohol acetate or propionate is used as the compound (a) or (c), or when a lower alcohol ester or the like of a carboxylic acid is used as the compound (b) or (c), a transesterification reaction is performed. It is possible to obtain an ester according to the invention.

  Specific examples of esterification used in the above esterification reaction include Lewis acids such as aluminum derivatives, tin derivatives and titanium derivatives; alkali metal salts such as sodium alkoxide and potassium alkoxide; paratoluenesulfonic acid and methanesulfonic acid And sulfonic acids such as sulfuric acid are exemplified, but among these, use of Lewis acids such as aluminum derivatives, tin derivatives and titanium derivatives is preferable because the thermal and hydrolytic stability of the resulting ester is further enhanced. Furthermore, tin derivatives are particularly preferable from the viewpoint of reaction efficiency. The usage-amount of said esterification catalyst is about 0.1-1 mass% with respect to the total amount of compound (a)-(c) which is a raw material, for example.

  As reaction temperature in said esterification reaction, 150-230 degreeC is illustrated, and reaction is normally completed in 3 to 30 hours.

  Further, after the esterification reaction is completed, excess raw materials are distilled off under reduced pressure or normal pressure, and subsequently subjected to conventional purification methods such as adsorption purification treatment such as liquid-liquid extraction, vacuum distillation, activated carbon treatment, etc. The ester can be purified.

In the above esterification reaction, for example, a compound having two hydroxyl groups as the compound (a), a compound having two carboxyl groups as the compound (b), and a compound having one carboxyl group as the compound (c) ( Hereinafter, when each of “compound (c-1)” and a compound having one hydroxyl group (hereinafter referred to as “compound (c-2)”) is used, the resulting reaction product has the following formula (1) ) To (6):
^{X 2 -COO-R 1 -OCO-} X 1 -COO-R 1 -OCO-X 2 (1)
^{R 2 -OCO-X 1 -COO-} R 1 -OCO-X 1 -COO-R 2 (2)
^{X 2 -COO-R 1 -OCO-} X 1 -COO-R 2 (3)
^{X 2 -COO-R 1 -OCO-} X 2 (4)
^{R 2 -OCO-X 1 -COO-} R 2 (5)
^{R 2 -OCO-X 2 (6} )
[In formulas (1) to (6), R ¹ represents a residue obtained by removing two hydroxyl groups from compound (a), and R ² represents a residue obtained by removing one hydroxyl group from compound (c-2). X ¹ represents a residue obtained by removing two carboxyl groups from compound (b), and X ² represents a residue obtained by removing one carboxyl group from compound (c-1).
(Hereinafter, for example, the compound represented by the above formula (1) is referred to as “compound (1)”).

  In the present invention, when the compounds obtained in the esterification reaction are the compounds (1) to (6), one of the compounds (1) to (3) is used alone or the compound ( It is preferable to use a combination of one or more of 1) to (3) and one or more of the compounds (4) to (6). In the case where the ester does not contain any of the above compounds (1) to (3) and is composed only of the above compounds (4) to (6), the balance of lubricity, stability and low temperature fluidity is balanced. It tends to be difficult to meet well.

In addition, when the ester according to the present invention is a mixture of one or more of the compounds (1) to (3) and one or more of the compounds (4) to (6), the content of each compound is Although not particularly limited, the content of each compound based on the total amount of the mixture is preferably within the following range from the viewpoint of the balance between refrigerant compatibility and various performances and ease of production.
Compound (1): 0 to 100% by mass, preferably 1 to 99% by mass, more preferably 5 to 95% by mass
Compound (2): 0 to 100% by mass, preferably 1 to 99% by mass, more preferably 5 to 95% by mass
Compound (3): 0 to 100% by mass, preferably 1 to 99% by mass, more preferably 5 to 95% by mass
Compound (4): 0 to 90% by mass, preferably 0 to 80% by mass, more preferably 0 to 75% by mass
Compound (5): 0 to 90% by mass, preferably 0 to 80% by mass, more preferably 0 to 75% by mass
Compound (6): 0 to 90% by mass, preferably 0 to 80% by mass, more preferably 0 to 75% by mass
Total of compounds (1) to (3): 10 to 100% by mass, preferably 20 to 100% by mass, more preferably 25 to 100% by mass
Total of compounds (4) to (6): 0 to 90% by mass, preferably 0 to 80% by mass, more preferably 0 to 75% by mass.

  Here, although the esterification reaction using specific compounds (a) to (c) has been described, the reaction product obtained may be a mixture even in other cases. Furthermore, when the ester according to the present invention is a mixture of two or more compounds, the compound (a) and the compound (b) are directly obtained from the viewpoint of the balance between refrigerant compatibility and various performances and ease of production. The content of the bound ester is preferably 10 to 100% by mass, more preferably 20 to 100% by mass, and still more preferably 25 to 100% by mass based on the total amount of the mixture.

Although the kinematic viscosity of such ester to the present invention is not particularly limited, preferably a kinematic viscosity at 40 ° C. is 3~1000mm ² / s, more preferably 4~700mm ² / s, 5~500mm ² / More preferably, it is s. It is preferable that kinematic viscosity at 100 ° C. of the esters are 1 to 50 mm ² / s, more preferably 1.5~40mm ² / s, more preferably from 2 to 30 mm ² / s . When the kinematic viscosity of the ester is within the above range, the lubricity, sealability, refrigerant compatibility, etc. tend to be satisfied in a more balanced manner. When the kinematic viscosity at 40 ° C. is less than 3 mm ² / s, the lubricity and the hermeticity of the compressor tend to decrease, and when it exceeds 500 mm ² / s, it is compatible with the refrigerant under low temperature conditions. The composition range showing the above becomes narrow, and the lubrication failure of the refrigerant compressor and the heat exchange in the evaporator tend to be hindered.

  Moreover, it is preferable that the pour point of the ester concerning this invention is -10 degrees C or less, and it is more preferable that it is -20--50 degreeC. When an ester having a pour point of −10 ° C. or higher is used, the refrigerating machine oil tends to solidify in the refrigerant circulation system at low temperatures.

  The refrigerating machine oil and working fluid composition for a refrigerating machine of the present invention contains an ester obtained using the above compounds (a) to (c), and even when only the ester is used alone, It exhibits excellent properties such as low-temperature fluidity, lubricity and stability that are sufficiently high, and a sufficiently wide compatibility region for fluoropropene refrigerants. An agent may be added. In addition, the content of the ester in the refrigerating machine oil and the working fluid composition for the refrigerating machine of the present invention is not particularly limited as long as the above-described excellent characteristics are not impaired, but it is 50% by mass or more based on the total amount of the refrigerating machine oil. The content is preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more. If the ester content is less than 50% by mass, any of various performances such as lubricity, refrigerant compatibility, sealability, thermal / chemical stability, and electrical insulation properties of the refrigerating machine oil will be insufficient. There is a tendency.

  The refrigerating machine oil of the present invention may consist only of the ester according to the present invention, but may further contain a base oil and various additives other than the ester. Moreover, the working fluid composition for a refrigerator of the present invention may further contain a base oil and various additives other than the ester according to the present invention. In the following description, the contents of base oils and additives other than esters according to the present invention are shown based on the total amount of refrigerating machine oil, but the contents of these components in the fluid composition for refrigerating machines are When the total amount of machine oil is used as a reference, it is desirable to select so as to be within a preferable range described later.

  Base oils other than esters according to the present invention include hydrocarbon oils such as mineral oil, olefin polymers, naphthalene compounds, and alkylbenzenes, and ester base oils other than esters according to the present invention (monoesters, diesters, polyol esters, etc.) ), Synthetic oils containing oxygen such as polyglycol, polyvinyl ether, ketone, polyphenyl ether, silicone, polysiloxane, perfluoroether may be used in combination. Among the above, as the synthetic oil containing oxygen, polyol esters and polyvinyl ether are preferably used.

  Moreover, the refrigerating machine oil of the present invention can be used in a form in which various additives are further blended as necessary. In the following description, the additive content is shown based on the total amount of the refrigerating machine oil composition, but the content of these components in the refrigerating machine fluid composition is based on the total amount of the refrigerating machine oil composition. In this case, it is desirable to select so that it is within a preferable range described later.

  In order to further improve the wear resistance and load resistance of the refrigerating machine oil and working fluid composition for the refrigerating machine of the present invention, phosphoric acid ester, acidic phosphoric acid ester, thiophosphoric acid ester, amine salt of acidic phosphoric acid ester, chlorine At least one phosphorus compound selected from the group consisting of phosphorylated phosphates and phosphites can be blended. These phosphorus compounds are esters of phosphoric acid or phosphorous acid with alkanols and polyether type alcohols or derivatives thereof.

  Specifically, for example, as phosphate ester, tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, tridodecyl phosphate, tritridecyl Phosphate, tritetradecyl phosphate, tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xyl Examples include rhenyl diphenyl phosphate.

  Examples of acidic phosphate esters include monobutyl acid phosphate, monopentyl acid phosphate, monohexyl acid phosphate, monoheptyl acid phosphate, monooctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate, monoundecyl acid phosphate, monododecyl Acid phosphate, monotridecyl acid phosphate, monotetradecyl acid phosphate, monopentadecyl acid phosphate, monohexadecyl acid phosphate, monoheptadecyl acid phosphate, monooctadecyl acid phosphate, monooleyl acid phosphate, dibutyl acid phosphate, dipentyl acid , Dihexyl reed Dophosphate, diheptyl acid phosphate, dioctyl acid phosphate, dinonyl acid phosphate, didecyl acid phosphate, diundecyl acid phosphate, didodecyl acid phosphate, ditridecyl acid phosphate, ditetradecyl acid phosphate, dipentadecyl acid, dipentadecyl acid Examples include hexadecyl acid phosphate, diheptadecyl acid phosphate, dioctadecyl acid phosphate, dioleyl acid phosphate, and the like.

  Examples of thiophosphates include tributyl phosphorothioate, tripentyl phosphorothionate, trihexyl phosphorothionate, triheptyl phosphorothionate, trioctyl phosphorothionate, trinonyl phosphorothionate, tridecyl phosphorothioate. Phorothionate, triundecyl phosphorothionate, tridodecyl phosphorothionate, tritridecyl phosphorothionate, tritetradecyl phosphorothionate, tripentadecyl phosphorothionate, trihexadecyl phosphorothionate, Triheptadecyl phosphorothioate, trioctadecyl phosphorothionate, trioleyl phosphorothionate, triphenyl phosphorothionate, tricresyl phosphorothionate, trixyl Cycloalkenyl phosphorothionate, cresyldiphenyl phosphorothionate, like carboxymethyl Les sulfonyl diphenyl phosphorothionate.

  Examples of the amine salt of acidic phosphate ester include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, Examples thereof include salts with amines such as dipentylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine.

  Examples of the chlorinated phosphate ester include tris-dichloropropyl phosphate, tris-chloroethyl phosphate, tris-chlorophenyl phosphate, polyoxyalkylene bis [di (chloroalkyl)] phosphate, and the like. As phosphites, dibutyl phosphite, dipentyl phosphite, dihexyl phosphite, diheptyl phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, didodecyl phosphite, dioleyl Phosphite, diphenyl phosphite, dicresyl phosphite, tributyl phosphite, tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, triundecyl phosphite Phyto, tridodecyl phosphite, trioleyl phosphite, triphenyl phosphite, tricresyl phosphite and the like can be mentioned. Mixtures of these can also be used.

  When the refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention contain the phosphorus compound, the content of the phosphorus compound is not particularly limited, but is based on the total amount of refrigerating machine oil (based on the total amount of base oil and all blended additives). It is preferable that it is 0.01-5.0 mass%, and it is more preferable that it is 0.02-3.0 mass%. In addition, the said phosphorus compound may be used individually by 1 type, and may use 2 or more types together.

  In addition, the refrigerating machine oil and the working fluid composition for the refrigerating machine of the present invention include a phenyl glycidyl ether type epoxy compound, an alkyl glycidyl ether type epoxy compound, and a glycidyl ester type epoxy compound in order to further improve the thermal and chemical stability. , An allyloxirane compound, an alkyloxirane compound, an alicyclic epoxy compound, an epoxidized fatty acid monoester, and an epoxidized vegetable oil can be contained.

  Specific examples of the phenyl glycidyl ether type epoxy compound include phenyl glycidyl ether and alkylphenyl glycidyl ether. As used herein, the alkylphenyl glycidyl ether includes those having 1 to 3 alkyl groups having 1 to 13 carbon atoms, and those having one alkyl group having 4 to 10 carbon atoms, such as n-butylphenyl glycidyl. Ether, i-butylphenyl glycidyl ether, sec-butylphenyl glycidyl ether, tert-butylphenyl glycidyl ether, pentylphenyl glycidyl ether, hexylphenyl glycidyl ether, heptylphenyl glycidyl ether, octylphenyl glycidyl ether, nonylphenyl glycidyl ether, decylphenyl A glycidyl ether etc. can be illustrated as a preferable thing.

  As the alkyl glycidyl ether type epoxy compound, specifically, decyl glycidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, 2-ethylhexyl glycidyl ether, neopentyl glycol diglycidyl ether, Examples thereof include trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, 1,6-hexanediol diglycidyl ether, sorbitol polyglycidyl ether, polyalkylene glycol monoglycidyl ether, and polyalkylene glycol diglycidyl ether.

  Specific examples of the glycidyl ester type epoxy compound include phenyl glycidyl ester, alkyl glycidyl ester, alkenyl glycidyl ester, etc., and preferable ones are glycidyl-2,2-dimethyloctanoate, glycidyl benzoate, glycidyl acrylate. And glycidyl methacrylate.

  Specific examples of the allyloxirane compound include 1,2-epoxystyrene and alkyl-1,2-epoxystyrene.

  Specific examples of the alkyloxirane compound include 1,2-epoxybutane, 1,2-epoxypentane, 1,2-epoxyhexane, 1,2-epoxyheptane, 1,2-epoxyoctane, 1,2- Epoxy nonane, 1,2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane, 1,2-epoxytridecane, 1,2-epoxytetradecane, 1,2-epoxypentadecane, 1,2- Examples include epoxyhexadecane, 1,2-epoxyheptadecane, 1,1,2-epoxyoctadecane, 2-epoxynonadecane, 1,2-epoxyicosane and the like.

  Specific examples of the alicyclic epoxy compound include 1,2-epoxycyclohexane, 1,2-epoxycyclopentane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and bis (3,4 -Epoxycyclohexylmethyl) adipate, exo-2,3-epoxynorbornane, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 2- (7-oxabicyclo [4.1.0] hept-3- Yl) -spiro (1,3-dioxane-5,3 ′-[7] oxabicyclo [4.1.0] heptane, 4- (1′-methylepoxyethyl) -1,2-epoxy-2-methyl Examples include cyclohexane and 4-epoxyethyl-1,2-epoxycyclohexane.

  Specific examples of the epoxidized fatty acid monoester include esters of an epoxidized fatty acid having 12 to 20 carbon atoms with an alcohol or phenol having 1 to 8 carbon atoms or an alkylphenol. In particular, butyl, hexyl, benzyl, cyclohexyl, methoxyethyl, octyl, phenyl and butylphenyl esters of epoxy stearate are preferably used.

  Specific examples of the epoxidized vegetable oil include epoxy compounds of vegetable oils such as soybean oil, linseed oil and cottonseed oil.

  Among these epoxy compounds, phenyl glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, alicyclic epoxy compounds and epoxidized fatty acid monoesters are preferred. Of these, phenyl glycidyl ether type epoxy compounds and glycidyl ester type epoxy compounds are more preferred, and phenyl glycidyl ether, butylphenyl glycidyl ether, alkyl glycidyl esters or mixtures thereof are particularly preferred.

  When the refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention contain the above epoxy compound, the content of the epoxy compound is not particularly limited, but is 0.1 to 5.0% by mass based on the total amount of the refrigerating machine oil. It is preferably 0.2 to 2.0% by mass. In addition, the said epoxy compound may be used individually by 1 type, and may use 2 or more types together.

  In addition, the refrigerating machine oil and the working fluid composition for the refrigerating machine of the present invention can contain conventionally known additives for refrigerating machine oil as necessary in order to further enhance the performance. Examples of such additives include phenolic antioxidants such as di-tert-butyl-p-cresol and bisphenol A, phenyl-α-naphthylamine, N, N-di (2-naphthyl) -p-phenylenediamine, and the like. Amine-based antioxidants, anti-wear agents such as zinc dithiophosphate, extreme pressure agents such as chlorinated paraffin and sulfur compounds, oil-based agents such as fatty acids, antifoaming agents such as silicones, metal inertness such as benzotriazole Agents, viscosity index improvers, pour point depressants, detergent dispersants and the like. These additives may be used individually by 1 type, and may be used in combination of 2 or more type. The content of these additives is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total amount of refrigerating machine oil.

The kinematic viscosity of the refrigerating machine oil of the present invention is not particularly limited, but the kinematic viscosity at 40 ° C. is preferably 3 to 1000 mm ² / s, more preferably 4 to 700 mm ² / s, and most preferably 5 to 500 mm ² / s. can do. The kinematic viscosity at 100 ° C. is preferably 1 to 100 mm ² / s, more preferably ² to 50 mm ² / s.

  Further, the water content of the refrigerating machine oil of the present invention is not particularly limited, but can be preferably 300 ppm or less, more preferably 200 ppm or less, and most preferably 100 ppm or less based on the total amount of refrigerating machine oil. In particular, when it is used for a hermetic type refrigerator, the moisture content is required to be small from the viewpoint of the influence on the thermal / chemical stability and electrical insulation of the refrigerator oil.

  Further, the acid value of the refrigerating machine oil of the present invention is not particularly limited, but it prevents corrosion of the metal used in the refrigerating machine or piping, and prevents the decomposition of the ester contained in the refrigerating machine oil of the present invention. Therefore, it can be preferably 0.1 mgKOH / g or less, more preferably 0.05 mgKOH / g or less. In addition, in this invention, an acid value means the acid value measured based on JISK2501 "Petroleum products and lubricating oil-neutralization value test method".

  Further, the hydroxyl value of the refrigerating machine oil of the present invention is not particularly limited, but the hydroxyl value is preferably 20 mgKOH / g or less, more preferably 10 mgKOH / g or less, and further preferably 5 mgKOH / g or less.

  Further, the ash content of the refrigerating machine oil of the present invention is not particularly limited, but is preferably 100 ppm or less, more preferably 50 ppm or less in order to increase the thermal and chemical stability of the refrigerating machine oil of the present invention and suppress the generation of sludge and the like. be able to. In the present invention, the ash means the value of ash measured in accordance with JIS K2272 “Testing method for ash and sulfated ash of crude oil and petroleum products”.

  The refrigerating machine oil of the present invention is used together with a fluoropropene refrigerant, and the working fluid composition for a refrigerating machine of the present invention contains a fluoropropene refrigerant.

  As the fluoropropene refrigerant, fluoropropene having 3 to 5 fluorine atoms is preferable. 1,2,3,3,3-pentafluoropropene (HFC-1225ye), 1,3,3,3-tetrafluoropropene (HFC) -1234ze), 2,3,3,3-tetrafluoropropene (HFC-1234yf), 1,2,3,3-tetrafluoropropene (HFC1234ye), and 3,3,3-trifluoropropene (HFC-1243zf) 1) or a mixture of two or more of them. From the viewpoint of the physical properties of the refrigerant, it is preferably one or more selected from HFC-1225ye, HFC-1234ze, and HFC-1234yf.

  The refrigerant used in the present invention may be a mixed refrigerant of a fluoropropene refrigerant and another refrigerant. Examples of other refrigerants include HFC refrigerants, fluorine-containing ether refrigerants such as bar fluoroethers, and natural refrigerants such as dimethyl ether, ammonia, and hydrocarbons.

  Examples of the HFC refrigerant include hydrofluorocarbons having 1 to 3 carbon atoms, preferably 1 to 2 carbon atoms. Specifically, for example, difluoromethane (HFC-32), trifluoromethane (HFC-23), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1, 1,1,2-tetrafluoroethane (HFC-134a), 1,1,1-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1 1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1,2,3,3-hexafluoropropane (HFC-236ea), 1,1,1,3 , 3,3-hexafluoropropane (HFC-236fa), 1,1,1,3,3-pentafluoropropane (HFC-245fa), and 1,1, , 3,3-pentafluorobutane (HFC-365mfc), or a mixture of two or more thereof. These refrigerants are appropriately selected depending on the application and required performance. For example, HFC-32 alone; HFC-23 alone; HFC-134a alone; HFC-125 alone; HFC-134a / HFC-32 = 60 to 80 mass % / 40-20 mass% mixture; HFC-32 / HFC-125 = 40-70 mass% / 60-30 mass% mixture; HFC-125 / HFC-143a = 40-60 mass% / 60-40 mass % Mixture; HFC-134a / HFC-32 / HFC-125 = 60 wt% / 30 wt% / 10 wt% mixture; HFC-134a / HFC-32 / HFC-125 = 40-70 wt% / 15- 35 mass% / 5 to 40 mass% mixture; HFC-125 / HFC-134a / HFC-143a = 35-55 mass% / 1-15 mass% / 40-60 mass Such as a mixture of preferred examples include. More specifically, a mixture of HFC-134a / HFC-32 = 70/30 mass%; a mixture of HFC-32 / HFC-125 = 60/40 mass%; HFC-32 / HFC-125 = 50/50 mass % Mixture (R410A); HFC-32 / HFC-125 = 45/55 wt% mixture (R410B); HFC-125 / HFC-143a = 50/50 wt% mixture (R507C); HFC-32 / HFC -125 / HFC-134a = 30/10/60 wt% mixture; HFC-32 / HFC-125 / HFC-134a = 23/25/52 wt% mixture (R407C); HFC-32 / HFC-125 / HFC-134a = 25/15/60 mass% mixture (R407E); HFC-125 / HFC-134a / HFC-143a = Mixtures of 4/4/52 wt% (R404A), and the like.

  Of the HFC refrigerants, saturated hydrofluorocarbons include difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1. , 1,2-Tetrafluoroethane (HFC-134a), 1,1-difluoroethane (HFC-152a), fluoroethane (HFC-161), 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea), 1,1,1,2,3,3-hexafluoropropane (HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (HFC-236fa), 1, 1,1,3,3-pentafluoropropane (HFC-245fa), 1,1,1,3,3-pentafluorobutane (HFC-365 fc) is preferably one or a mixture of two or more, and from the viewpoint of refrigerant physical properties, HFC-32, HFC-125, HFC-134a, HFC-152a, or HFC-32 and HFC- A mixture of 134a is preferred.

  The hydrocarbon refrigerant is preferably a hydrocarbon having 3 to 5 carbon atoms, specifically, for example, methane, ethylene, ethane, propylene, propane, cyclopropane, normal butane, isobutane, cyclobutane, methylcyclopropane, 2-methylbutane. , Normal pentane, or a mixture of two or more thereof. Among these, gas at 25 ° C. and 1 atm is preferably used, and propane, normal butane, isobutane, 2-methylbutane or a mixture thereof is preferable.

  Specific examples of the fluorinated ether refrigerant include HFE-134p, HFE-245mc, HFE-236mf, HFE-236me, HFE-338mcf, HFE-365mcf, HFE-245mf, HFE-347mmy, HFE-347mcc, HFE-125, HFE-143m, HFE-134m, HFE-227me, etc. are mentioned, These refrigerant | coolants are suitably selected according to a use or required performance.

  When the refrigerant used in the present invention is a mixed refrigerant, the mixed refrigerant is at least one selected from fluoropropene refrigerant (hereinafter referred to as “refrigerant (A)”), saturated hydrofluorocarbon, 3 to 3 carbon atoms. 5 hydrocarbons, dimethyl ether, carbon dioxide, bis (trifluoromethyl) sulfide and at least one selected from trifluoroiodomethane refrigerant (hereinafter referred to as “refrigerant (B)”). .

  Further, when the refrigerant used in the present invention is a mixed refrigerant containing the refrigerant (A) and the refrigerant (B), the mixed refrigerant is preferably an azeotropic mixture, but has physical properties necessary as a refrigerant. If it does, it does not need to be an azeotrope in particular, The mixing ratio of both is preferably 1:99 to 99: 1, more preferably 5:95 to 95: 5.

  Furthermore, when the refrigerant used in the present invention is a mixed refrigerant containing the refrigerant (A) and the refrigerant (B), the mixed refrigerant is an HFC refrigerant other than a fluoropropene refrigerant or a saturated hydrofluorocarbon, or a bar fluoroether. And other natural refrigerants such as ammonia or hydrocarbons other than hydrocarbons having 3 to 5 carbon atoms.

  The refrigerating machine oil of the present invention is usually present in the form of a fluid composition for a refrigerating machine mixed with a fluoropropene refrigerant or a mixed refrigerant as described above in a refrigerating and air-conditioning apparatus. The mixing ratio of the refrigerating machine oil and the refrigerant in the composition and the mixing ratio of the refrigerating machine oil and the refrigerant in the working fluid composition for a refrigerating machine of the present invention are not particularly limited, but the refrigerating machine oil is preferable with respect to 100 parts by mass of the refrigerant. Is 1 to 500 parts by mass, more preferably 2 to 400 parts by mass.

  The refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention are preferably used for an air conditioner, a refrigerator, or an open or sealed car air conditioner having a reciprocating or rotating hermetic compressor. Further, the refrigerating machine oil and the working fluid composition for the refrigerating machine of the present invention are preferably used for a dehumidifier, a water heater, a freezer, a freezer / refrigerated warehouse, a vending machine, a showcase, a cooling device for a chemical plant, and the like. Furthermore, the refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention are also preferably used for those having a centrifugal compressor.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

[Examples 1-4, Comparative Examples 1-2]
In Examples 1-4 and Comparative Examples 1-2, refrigeration oil was prepared using base oils 1-6 shown below. Various properties of the obtained refrigerating machine oil are shown in Table 1.

(Base oil)
Base oil 1: Esters obtained by reacting 1 mol of adipic acid and succinic acid and 2 mol of 3,5,5-trimethylhexanoic acid, respectively, with 2 mol of neopentyl glycol.
Base oil 2: An ester obtained by reacting 2 moles of succinic acid and glutaric acid with 2 moles of 2-methylbutanoic acid and 2-ethylbutanoic acid with respect to 2 moles of trimethylolpropane, respectively.
Base oil 3: An ester obtained by reacting 1 mol of succinic acid and glutaric acid, and 2 mol of 2-methylbutanoic acid and 2 mol of 2-ethylbutanoic acid, respectively, with 2 mol of pentaerythritol.
Base oil 4: An ester obtained by reacting 2 moles of adipic acid with 1 mole each of neopentyl glycol and 3,5,5-trimethylhexyl alcohol.
Base oil 5: Ester base oil of n-heptanoic acid and pentaerythritol 6: Naphthenic mineral oil

  Next, the evaluation test shown below was implemented about each refrigeration oil of Examples 1-4 and Comparative Examples 1-2.

(Evaluation of refrigerant compatibility)
In accordance with JIS-K-2211 “Refrigerating machine oil” “Compatibility testing method with refrigerant”, 2 g of refrigerating machine oil is blended with 18 g of 2,3,3,3-tetrafluoropropene, and the refrigerant and refrigerating machine oil are mixed. Were observed to be mutually dissolved at 0 ° C. The obtained results are shown in Table 1. In Table 1, “compatible” means that the refrigerant and the refrigerating machine oil are mutually dissolved, and “separation” means that the refrigerant and the refrigerating machine oil are separated into two layers.

(Evaluation of thermal and chemical stability)
In accordance with JIS-K-2211, 1 g of refrigerating machine oil (initial hue L0.5) whose water content was adjusted to 100 ppm or less, 1 g of 2,3,3,3-tetrafluoropropene, and catalyst (iron, copper, aluminum) Each wire) was sealed in a glass tube, heated to 150 ° C. and held for 1 week for testing. After the test, the hue of the refrigerator oil composition and the color change of the catalyst were evaluated. Hue was evaluated according to ASTM D156. Further, the color change of the catalyst was visually observed for the appearance, and it was evaluated whether it corresponded to no change, no gloss, or blackening. The obtained results are shown in Table 1.

  As is clear from the results shown in Table 1, it can be seen that the refrigerating machine oils of Examples 1 to 4 are excellent in refrigerant compatibility when used together with a fluoropropene refrigerant.

Claims (5)

The following compounds (a) to (c):
(A) a compound having two or more hydroxyl groups or a derivative thereof,
(B) a compound having two or more carboxyl groups or a derivative thereof, and (c) a compound having one carboxyl group or a derivative thereof and / or an ester obtained using a compound having one hydroxyl group or a derivative thereof. Base oil,
A fluoropropene refrigerant;
Containing
A working fluid composition for a refrigerator, wherein the pour point of the ester is -10 ° C or lower.   As the fluoropropene refrigerant, 1,2,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene, 1,2,3, The working fluid composition for a refrigerator according to claim 1, comprising at least one selected from 3-tetrafluoropropene and 3,3,3-trifluoropropene.   Containing the fluoropropene refrigerant and at least one selected from saturated hydrofluorocarbons, hydrocarbons having 3 to 5 carbon atoms, dimethyl ether, carbon dioxide, bis (trifluoromethyl) sulfide, and trifluoroiodomethane refrigerant. The working fluid composition for a refrigerator according to claim 1 or 2, wherein   The fluoropropene refrigerant is 1,2,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene, 1,2,3, At least one selected from 3-tetrafluoropropene and 3,3,3-trifluoropropene, and the saturated hydrofluorocarbon is difluoromethane, pentafluoroethane, 1,1,2,2-tetrafluoroethane, 1 , 1,1,2-tetrafluoroethane, 1,1-difluoroethane, fluoroethane, 1,1,1,2,3,3,3-heptafluoropropane, 1,1,1,2,3,3- Hexafluoropropane, 1,1,1,3,3,3-hexafluoropropane, 1,1,1,3,3-pentafluoropropane and 1,1,1,3,3 It is at least one selected from pentafluorobutane, and the hydrocarbon having 3 to 5 carbon atoms is at least one selected from propane, normal butane, isobutane, 2-methylbutane and normal pentane, The working fluid composition for a refrigerator according to claim 3. The following compounds (a) to (c):
(A) a compound having two or more hydroxyl groups or a derivative thereof,
(B) a compound having two or more carboxyl groups or a derivative thereof, and (c) a compound having one carboxyl group or a derivative thereof and / or an ester obtained using a compound having one hydroxyl group or a derivative thereof. ,
The pour point of the ester is −10 ° C. or lower,
A refrigerating machine oil characterized by being used together with a fluoropropene refrigerant.