JP5399821B2 - Refrigerator oil and working fluid composition for refrigerator - Google Patents

Description

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

  Due to the problem of ozone depletion 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. Has been.

  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, viscosity during refrigerant dissolution, 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 refrigerant to HFC-134a, both ODP and GWP are very small, non-flammable, and thermodynamic characteristics that are a measure of refrigerant performance are almost equivalent to HFC-134a. More than that, the use of refrigerants of unsaturated fluorinated hydrocarbons has been proposed. In addition, use of mixed refrigerants of unsaturated fluorinated hydrocarbons and saturated hydrofluorocarbons, saturated hydrocarbons having 3 to 5 carbon atoms, dimethyl ether, carbon dioxide, bis (trifluoromethyl) sulfide, or trifluoroiodomethane is also proposed. (See Patent Document 5).

  Also, unsaturated fluorinated hydrocarbon refrigerant or unsaturated fluorinated hydrocarbon and saturated hydrofluorocarbon, saturated hydrocarbon having 3 to 5 carbon atoms, dimethyl ether, carbon dioxide, bis (trifluoromethyl) sulfide, or trifluoroiodomethane Refrigerating machine oils that can be used with refrigerants such as mineral oil, alkylbenzenes, polyalphaolefins, polyalkylene glycols, monoesters, diesters, polyol esters, phthalates, alkyl ethers, ketones , Refrigerating machine oils using carbonates, polyvinyl ethers, and the like have 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 above, in refrigeration systems that use unsaturated fluorinated hydrocarbon refrigerants, mineral oils used in CFCs and HCFCs, hydrocarbons such as alkylbenzenes, and HFCs It is considered that any of refrigerating machine oils such as polyalkylene glycols, polyol esters, and polyvinyl ethers that are used are applicable. However, according to the study by the present inventors, it has been found that various required performances cannot be achieved at a high level simply by diverting these conventional refrigeration oils as they are to the system. In particular, in the case of ether-based refrigeration oils such as polyalkylene glycol and polyvinyl ether, in the presence of an unsaturated fluorinated hydrocarbon refrigerant, the refrigerant or the refrigeration oil may be decomposed to cause a system malfunction. Further, it has been found that the stability in the presence of an unsaturated fluorinated hydrocarbon refrigerant is further deteriorated when a conventionally used antiwear agent is added to improve wear resistance.

  The present invention has been made in view of such circumstances, and in a refrigeration system using an unsaturated fluorinated hydrocarbon refrigerant, the stability and wear resistance in the presence of the unsaturated fluorinated hydrocarbon refrigerant are high. It is an object of the present invention to provide a refrigerating machine oil and a working fluid composition for a refrigerating machine that are compatible with each other.

In order to solve the above problems, the present invention provides a refrigeration containing a base oil containing an ether compound, an amine salt of an acidic phosphate ester, an amine antioxidant, a metal deactivator and an alicyclic epoxy compound. It contains machine oil and an unsaturated fluorinated hydrocarbon refrigerant, and the content of amine salt of acidic phosphate ester is 400 mass ppm or more and 5000 mass ppm or less based on the total amount of refrigerating machine oil. A working fluid composition for a refrigerator is provided.

The present invention also includes a base oil containing an ether compound, an amine salt of an acidic phosphate ester, an amine antioxidant, a metal deactivator and an alicyclic epoxy compound, and an amine of an acidic phosphate ester. Provided is a refrigerating machine oil characterized by having a salt content of 400 mass ppm or more and 5000 mass ppm or less based on the total amount of refrigerating machine oil, and being used together with an unsaturated fluorinated hydrocarbon refrigerant.

  The fluid working fluid composition for refrigerators of the present invention includes 1,2,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, 2, It is preferable to contain at least one selected from 3,3,3-tetrafluoropropene, 1,2,3,3-tetrafluoropropene and 3,3,3-trifluoropropene.

  Further, the working fluid composition for a refrigerator of the present invention may use at least one unsaturated fluorohydrocarbon refrigerant (hereinafter referred to as “refrigerant (A)”) alone, saturated hydrofluorocarbon, carbon. It further contains at least one selected from hydrocarbons of several to five, dimethyl ether, carbon dioxide, bis (trifluoromethyl) sulfide, and trifluoroiodomethane refrigerant (hereinafter referred to as “refrigerant (B)”). It may be.

Furthermore, in the mixed refrigerant of the refrigerant (A) and the refrigerant (B), as the unsaturated fluorinated hydrocarbon refrigerant, 1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,3,3 3,3-tetrafluoropropene (HFO-1234ze), 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,2,3,3-tetrafluoropropene (HFO-1234ye) and 3,3 , 3-trifluoropropene (HFO-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 -Selected from pentafluoropropane (HFC-245fa) and 1,1,1,3,3-pentafluorobutane (HFC-365mfc) Preferably one even without;
The hydrocarbon having 3 to 5 carbon atoms is preferably at least one selected from propane, normal butane, isobutane, 2-methylbutane and normal pentane.

  According to the present invention, in a refrigeration system using an unsaturated fluorinated hydrocarbon refrigerant, refrigerating machine oil and refrigeration capable of achieving both high stability and wear resistance in the presence of the unsaturated fluorinated hydrocarbon refrigerant. A mechanical working fluid composition is provided.

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

  The refrigerating machine oil of the present invention contains a base oil containing an ether compound, an amine salt of an acidic phosphate ester, an amine antioxidant, a metal deactivator and an alicyclic epoxy compound. The content of the amine salt is 400 mass ppm or more based on the total amount of the refrigerating machine oil, and the amine salt is used together with the unsaturated fluorinated hydrocarbon refrigerant. The working fluid composition for a refrigerator according to the present invention contains a base oil containing an ether compound, an amine salt of an acidic phosphate ester, an amine antioxidant, a metal deactivator, and an alicyclic epoxy. It contains a refrigerating machine oil and an unsaturated fluorinated hydrocarbon refrigerant, and the content of the amine salt of acidic phosphate is 400 ppm by mass or more based on the total amount of refrigerating machine oil. Here, the working fluid composition for a refrigerator of the present invention includes an embodiment containing the refrigerator oil of the present invention and an unsaturated fluorinated hydrocarbon refrigerant.

  In the present invention, the ether compound constituting the base oil is not particularly limited as long as it is a compound having one or more ether bonds in the molecule. Specifically, polyalkylene glycol, polyvinyl ether, polyphenyl ether, perfluoroether and the like are listed, and among them, polyalkylene glycol and polyvinyl ether are preferably used.

Examples of the polyalkylene glycol include a compound represented by the following general formula (1).
R ¹ -[(OR ² ) _f -OR ³ ] _g (1)
[In Formula (1), R ¹ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an acyl group having 2 to 10 carbon atoms, or a residue of a compound having 2 to 8 hydroxyl groups, and R ² represents the number of carbon atoms. Represents an alkylene group having 2 to 4, R ³ represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an acyl group having 2 to 10 carbon atoms, f represents an integer of 1 to 80, and g represents 1 to 8 Represents an integer. ]

In the general formula (1), the alkyl group represented by R ¹ and R ³ may be linear, branched or cyclic. Preferably the carbon number of the said alkyl group is 1-10, More preferably, it is 1-6. When the number of carbon atoms in the alkyl group exceeds 10, the compatibility with the working medium tends to decrease.

Moreover, the alkyl group part of the acyl group represented by R ¹ and R ³ may be linear, branched, or cyclic. Carbon number of an acyl group becomes like this. Preferably it is 2-10, More preferably, it is 2-6. If the number of carbon atoms in the acyl group exceeds 10, the compatibility with the working medium may be reduced and phase separation may occur.

When the groups represented by R ¹ and R ³ are both alkyl groups or are both acyl groups, the groups represented by R ¹ and R ³ may be the same or different. Furthermore, when g is 2 or more, the groups represented by a plurality of R ¹ and R ³ in the same molecule may be the same or different.

When the group represented by R ¹ is a residue of a compound having 2 to 8 hydroxyl groups, this compound may be a chain or a cyclic one.

Among the polyalkylene glycols represented by the general formula (1), at least one of R ¹ and R ³ is preferably an alkyl group (more preferably an alkyl group having 1 to 4 carbon atoms), particularly methyl. The group is preferable from the viewpoint of compatibility with the working medium.

Furthermore, from the viewpoint of thermal and chemical stability, it is preferable that both R ¹ and R ³ are alkyl groups (more preferably, alkyl groups having 1 to 4 carbon atoms), and particularly that both are methyl groups. Is preferred.

From the viewpoint of ease of production and cost, it is preferable that either R ¹ or R ³ is an alkyl group (more preferably an alkyl group having 1 to 4 carbon atoms) and the other is a hydrogen atom. It is preferable that one is a methyl group and the other is a hydrogen atom.

R ² in the general formula (1) represents an alkylene group having 2 to 4 carbon atoms, and specific examples of such an alkylene group include an ethylene group, a propylene group, and a butylene group. Examples of the oxyalkylene group of the repeating unit represented by OR ² include an oxyethylene group, an oxypropylene group, and an oxybutylene group. The oxyalkylene groups in the same molecule may be the same, or two or more oxyalkylene groups may be included.

  Among the polyalkylene glycols represented by the general formula (1), a copolymer containing an oxyethylene group (EO) and an oxypropylene group (PO) is preferable from the viewpoint of viscosity-temperature characteristics. In this case, the ratio (EO / (PO + EO)) of the oxyethylene group to the total of the oxyethylene group and the oxypropylene group is in the range of 0.1 to 0.8 from the standpoint of baking load and viscosity-temperature characteristics. Is preferable, and it is more preferable to be in the range of 0.3 to 0.6.

  In addition, the value of EO / (PO + EO) is preferably in the range of 0 to 0.5, and in the range of 0 to 0.2 in terms of compatibility with the working medium, hygroscopicity, and heat / oxidation stability. More preferably, it is most preferably 0 (that is, a propylene oxide homopolymer).

F of the general formula (1) represents the repetition number of the oxyalkylene group OR ² (degree of polymerization) is an integer of 1 to 80. Moreover, g is an integer of 1-8. For example, when R ¹ is an alkyl group or an acyl group, g is 1. When R ¹ is a residue of a compound having 2 to 8 hydroxyl groups, g is the number of hydroxyl groups that the compound has.

  In addition, the product of f and g (f × g) is not particularly limited, but in order to satisfy the required performance as the above-described lubricating oil for a refrigerator in a balanced manner, the average value of f × g is 6 to 80. It is preferable to do so.

  The number average molecular weight of the polyalkylene glycol represented by the general formula (1) is preferably 500 to 3000, more preferably 600 to 2000, more preferably 600 to 1500, and n is the number average molecular weight of the polyalkylene glycol. It is preferable that the number satisfies the above conditions. When the number average molecular weight of the polyalkylene glycol is too low, the lubricity in the presence of the unsaturated fluorinated hydrocarbon refrigerant becomes insufficient. On the other hand, if the number average molecular weight is too high, the composition range showing compatibility with the unsaturated fluorinated hydrocarbon refrigerant under low temperature conditions is narrowed, resulting in poor lubrication of the refrigerant compressor and inhibition of heat exchange in the evaporator. Is likely to occur. In the polyalkylene glycol represented by the general formula (1), the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.00 to 1.20 or less. Is preferred. When Mw / Mn exceeds 1.20, the compatibility between the unsaturated fluorinated hydrocarbon refrigerant and the refrigerating machine oil tends to be insufficient.

Among the polyalkylene glycols, polypropylene glycol dimethyl ether represented by the following general formula (2) and polyethylene polypropylene glycol dimethyl ether represented by the following general formula (3) are preferable in terms of economy and the above-mentioned effects, In addition, polypropylene glycol monobutyl ether represented by the following general formula (4), further polypropylene glycol monomethyl ether represented by the following general formula (5), polyethylene polypropylene glycol monomethyl ether represented by the following general formula (6), Polyethylene polypropylene glycol monobutyl ether represented by the following general formula (7) and polypropylene glycol diacetate represented by the following general formula (8) are preferable in terms of economy and the like.
_{CH 3 O- (C 3 H 6} O) h -CH 3 (2)
(In the formula, h represents a number of 6 to 80.)
_{CH 3 O- (C 2 H 4} O) i - (C 3 H 6 O) j -CH 3 (3)
(In the formula, i and j each represent a number that is 1 or more and the sum of i and j is 6 to 80.)
_{C 4 H 9 O- (C 3} H 6 O) k -H (4)
(In the formula, k represents a number of 6 to 80.)
_{CH 3 O- (C 3 H 6} O) l -H (5)
(In the formula, l represents a number of 6 to 80.)
_{CH 3 O- (C 2 H 4} O) m - (C 3 H 6 O) n -H (6)
(In the formula, m and n each represent a number that is 1 or more and the sum of m and n is 6 to 80.)
_{C 4 H 9 O- (C 2} H 4 O) m - (C 3 H 6 O) n -H (7)
(In the formula, m and n each represent a number that is 1 or more and the sum of m and n is 6 to 80.)
_{CH 3 COO- (C 3 H 6} O) l -COCH 3 (8)
(In the formula, l represents a number of 6 to 80.)

［式（９）中、Ｒ^４〜Ｒ^７は同一でも異なっていてもよく、それぞれ水素原子、炭素数１〜１０の１価の炭化水素基または下記一般式（１３）：

［式（１０）中、Ｒ^８およびＲ^９は同一でも異なっていてもよく、それぞれ水素原子、炭素数１〜１０の１価の炭化水素基または炭素数２〜２０のアルコキシアルキル基を表し、Ｒ^１０は炭素数２〜５のアルキレン基、アルキル基を置換基として有する総炭素数２〜５の置換アルキレン基またはアルコキシアルキル基を置換基として有する総炭素数４〜１０の置換アルキレン基を表し、ｒは０〜２０の整数を表し、Ｒ^１３は炭素数１〜１０の１価の炭化水素基を表す）で表される基を表し、Ｒ^８〜Ｒ^１１の少なくとも１つが一般式（１３）で表される基である。］ In the present invention, a polyalkylene glycol derivative having at least one structural unit represented by the general formula (9) can be used as the polyalkylene glycol.

[In Formula (9), R ^{4 to} R ⁷ may be the same or different, and are each a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or the following General Formula (13):

[In Formula (10), R ⁸ and R ⁹ may be the same or different and each represents a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms, R ¹⁰ represents an alkylene group having 2 to 5 carbon atoms, a substituted alkylene group having 2 to 5 carbon atoms having an alkyl group as a substituent, or a substituted alkylene group having 4 to 10 carbon atoms having an alkoxyalkyl group as a substituent. , R represents an integer of 0 to 20, R ¹³ represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, and at least one of R ^{8 to} R ¹¹ is represented by the general formula (13 ). ]

In the general formula (9), R ^{4 to} R ⁷ each represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a group represented by the general formula (10). Specific examples of the monovalent hydrocarbon group having 10 include linear or branched alkyl groups having 1 to 10 carbon atoms, linear or branched alkenyl groups having 2 to 10 carbon atoms, Examples thereof include a cycloalkyl group having 5 to 10 carbon atoms or an alkylcycloalkyl group, an aryl group having 6 to 10 carbon atoms or an alkylaryl group, and an arylalkyl group having 7 to 10 carbon atoms. Among these monovalent hydrocarbon groups, a monovalent hydrocarbon group having 6 or less carbon atoms, particularly an alkyl group having 3 or less carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group. preferable.

In the general formula (10), R ⁸ and R ⁹ each represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or an alkoxyalkyl group having 2 to 20 carbon atoms. An alkyl group having a number of 3 or less or an alkoxyalkyl group having a carbon number of 6 or less is preferred.

In the general formula (10), R ¹⁰ is an alkylene group having 2 to 5 carbon atoms, a substituted alkylene group having 2 to 5 carbon atoms having an alkyl group as a substituent, or a total carbon number 4 having an alkoxyalkyl group as a substituent. Represents a substituted alkylene group having 10 to 10 carbon atoms, preferably an alkylene group having 2 to 4 carbon atoms and a substituted ethylene group having 6 or less carbon atoms in total.

In the general formula (10), R ¹¹ represents a monovalent hydrocarbon group having 1 to 10 carbon atoms. Specifically, as the hydrocarbon group, a linear or 1 to 10 carbon atom or A branched alkyl group, a linear or branched alkenyl group having 2 to 10 carbon atoms, a cycloalkyl group or alkylcycloalkyl group having 5 to 10 carbon atoms, an aryl group or alkylaryl having 6 to 10 carbon atoms Group, an arylalkyl group having 7 to 10 carbon atoms, and the like. Among these, a monovalent hydrocarbon group having 6 or less carbon atoms is preferable, and an alkyl group having 3 or less carbon atoms is particularly preferable.

In the general formula (9), at least one of R ^{4 to} R ⁷ is a group represented by the general formula (10). In particular, any one of R ^{4 and} R ⁶ is a group represented by the above general formula (10), and the remaining one of R ⁴ or R ⁶ and R ⁵ and R ⁷ are each a hydrogen atom or carbon. A monovalent hydrocarbon group having 1 to 10 is preferable.

［式（１１）中、Ｒ^１２〜Ｒ^１５は同一でも異なっていてもよく、それぞれ水素原子または炭素数１〜３のアルキル基を示す。］ The polyalkylene glycol having the structural unit represented by the general formula (9), preferably used in the present invention, is a homopolymer consisting only of the structural unit represented by the general formula (9); A copolymer composed of two or more structural units represented by different structures and a structural unit represented by the general formula (9) and other structural units (for example, a structural unit represented by the following general formula (11)) It can be roughly divided into three types of copolymers consisting of: Preferred examples of the homopolymer include 1 to 200 structural units A represented by the general formula (9), and each terminal group is a hydroxyl group, an acyloxy group having 1 to 10 carbon atoms, or a 1 to 10 carbon atom. The thing which consists of an alkoxy group or an aryloxy group can be mentioned.

[In formula (11), R ^{12 to} R ¹⁵ may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ]

  On the other hand, suitable examples of the copolymer include 1 to 200 of the two types of structural units A and B represented by the general formula (9), or the structural unit A represented by the general formula (9). 1 to 200 and 1 to 200 structural units C represented by the general formula (10), and each terminal group is a hydroxyl group, an acyloxy group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or aryloxy The thing which consists of groups can be mentioned.

  These copolymers include alternating copolymerization of the structural unit A and the structural unit B (or the structural unit C), a random copolymer, a block copolymer, or a graft in which the structural unit B is graft-bonded to the main chain of the structural unit A. Any polymerization form of the copolymer may be used.

  The hydroxyl value of the polyalkylene glycol is not particularly limited, but is desirably 100 mgKOH / g or less, preferably 50 mgKOH / g or less, more preferably 30 mgKOH / g or less, and most preferably 10 mgKOH / g or less.

The polyalkylene glycol according to the present invention can be synthesized by a conventionally known method ("alkylene oxide polymer", Mitsuta Shibata et al., Kaibundo, issued on November 20, 1990). For example, an alcohol (R 1 ^OH; R ¹ represents the same definition as R ¹ in the general formula (1)) by addition polymerization of one or more predetermined alkylene oxide to, etherified or further terminal hydroxyl group By esterification, the polyalkylene glycol represented by the general formula (1) is obtained. When two or more different alkylene oxides are used in the above production process, the resulting polyalkylene glycol may be either a random copolymer or a block copolymer, but tends to be more excellent in oxidative stability. Therefore, a block copolymer is preferable, and a random copolymer is preferable because it tends to be more excellent in low-temperature fluidity.

The kinematic viscosity at 100 ° C. of the polyalkylene glycol according to the present invention is preferably 5 to 20 mm ² / s, preferably 6 to 18 mm ² / s, more preferably 7 to 16 mm ² / s, and still more preferably 8 to. 15 mm ² / s, most preferably 9~13mm ² / s. When the kinematic viscosity at 100 ° C. is less than the lower limit, the lubricity in the presence of the refrigerant becomes insufficient. On the other hand, when the upper limit is exceeded, the composition range showing compatibility with the refrigerant becomes narrow, and the refrigerant compression Machine lubrication and heat exchange in the evaporator are likely to be hindered. Moreover, kinematic viscosity at 40 ° C. of the polyalkylene glycol is preferably 10 to 200 mm ² / s, more preferably 20 to 150 mm ² / s. If the kinematic viscosity at 40 ° C. is less than 10 mm ² / s, the lubricity and the sealing performance of the compressor tend to be reduced. If the kinematic viscosity exceeds 200 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, the pour point of the polyalkylene glycol represented by the general formula (1) is preferably −10 ° C. or less, and more preferably −20 to −50 ° C. When a polyalkylene glycol 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.

  Further, in the production process of the polyalkylene glycol represented by the general formula (1), an alkylene oxide such as propylene oxide may cause a side reaction to form an unsaturated group such as an allyl group in the molecule. When an unsaturated group is formed in the polyalkylene glycol molecule, the thermal stability of the polyalkylene glycol itself is reduced, a polymer is produced and sludge is produced, or the antioxidant property (antioxidant property) is lowered. Therefore, a phenomenon such as generation of peroxide is likely to occur. In particular, when a peroxide is generated, it decomposes to generate a compound having a carbonyl group, and the compound having a carbonyl group generates sludge, which easily causes capillary clogging.

  Accordingly, the polyalkylene glycol according to the present invention preferably has a low degree of unsaturation derived from an unsaturated group or the like, specifically preferably 0.04 meq / g or less, and 0.03 meq / g or less. It is more preferable that it is 0.02 meq / g or less. The peroxide value is preferably 10.0 meq / kg or less, more preferably 5.0 meq / kg or less, and most preferably 1.0 meq / kg. Furthermore, the carbonyl value is preferably 100 ppm by weight or less, more preferably 50 ppm by weight or less, and most preferably 20 ppm by weight or less.

  In addition, the degree of unsaturation, the peroxide value, and the carbonyl value according to the present invention are values measured by a standard oil analysis test method established by the Japan Oil Chemists' Society. That is, the degree of unsaturation according to the present invention refers to reacting a sample with a Wis solution (ICl-acetic acid solution), leaving it in the dark, and then reducing excess ICl to iodine, and converting the iodine content with sodium thiosulfate. The iodine value is calculated by titration, and the iodine value is converted into a vinyl equivalent (meq / g); the peroxide value according to the present invention refers to the free iodine produced by adding potassium iodide to a sample. Is a value (meq / kg) obtained by converting this free iodine into the number of milliequivalents per 1 kg of the sample; the carbonyl value according to the present invention refers to 2,4-dinitrophenylhydrazine added to the sample. The quinoid ion is colored, and the absorbance at 480 nm of this sample is measured. Based on the calibration curve obtained in advance using cinnamaldehyde as a standard substance, Say-converted value Le amount (wt ppm).

  In the present invention, in order to obtain a polyalkylene glycol having a low degree of unsaturation, peroxide value, and carbonyl value, the reaction temperature when reacting propylene oxide is 120 ° C. or lower (more preferably 110 ° C. or lower). preferable. In addition, if an alkali catalyst is used in the production, the use of an inorganic adsorbent, such as activated carbon, activated clay, bentonite, dolomite, aluminosilicate, etc., to remove it may reduce the degree of unsaturation. Can do. Further, when the polyalkylene glycol is produced or used, contact with oxygen is avoided as much as possible, and an increase in the peroxide value or carbonyl value can also be prevented by adding an antioxidant.

  The refrigerating machine oil of the present invention contains a polyalkylene glycol having the above-described configuration, and even when only the polyalkylene glycol is used alone, the low-temperature fluidity, lubricity and stability are sufficiently high. In addition, it exhibits excellent characteristics such as having a sufficiently wide compatibility region with the unsaturated fluorinated hydrocarbon refrigerant, but other base oils and additives described later may be added as necessary. The content of the polyalkylene glycol in the refrigerating machine oil of the present invention is not particularly limited as long as the above excellent characteristics are not impaired, but is preferably 50% by mass or more based on the total amount of refrigerating machine oil, 70 The content is more preferably at least mass%, more preferably at least 80 mass%, particularly preferably at least 90 mass%. If the content of the polyalkylene glycol represented by the general formula (1) is less than 50% by mass, any one of various performances such as refrigerating machine oil lubricity, refrigerant compatibility, thermal / chemical stability, etc. It tends to be insufficient.

  In the refrigerating machine oil of the present invention, the content of the polyalkylene glycol according to the present invention is not particularly limited. It is preferable to contain 50% by mass or more based on the total amount of machine oil, more preferably 70% by mass or more, still more preferably 80% by mass or more, and most preferably 90% by mass or more.

［式（１２）中、Ｒ^１６〜Ｒ^１８は同一でも異なっていてもよく、それぞれ水素原子または炭素数１〜８の炭化水素基を表し、Ｒ^１９は炭素数１〜１０の２価の炭化水素基または炭素数２〜２０の２価のエーテル結合酸素含有炭化水素基を表し、Ｒ^２０は炭素数１〜２０の炭化水素基を表し、ｓはその平均値が０〜１０の数を表し、Ｒ^１６〜Ｒ^２０は構成単位毎に同一であってもそれぞれ異なっていてもよく、また一般式（１２）で表される構成単位が複数のＲ^１９Ｏを有するとき、複数のＲ^１９Ｏは同一でも異なっていてもよい。］ Moreover, as a polyvinyl ether used in this invention, the polyvinyl ether type compound which has a structural unit represented, for example by following General formula (12) is mentioned.

[In the formula (12), R ^{16 to} R ¹⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and R ¹⁹ is a divalent carbon atom having 1 to 10 carbon atoms. Represents a hydrogen group or a divalent ether-bonded oxygen-containing hydrocarbon group having 2 to ²⁰ carbon atoms, R ²⁰ represents a hydrocarbon group having 1 to ²⁰ carbon atoms, and s represents a number having an average value of 0 to 10; , R ^{16 to} R ²⁰ may be the same or different for each structural unit, and when the structural unit represented by the general formula (12) has a plurality of R ¹⁹ O, a plurality of R ¹⁹ Os. May be the same or different. ]

［式（１３）中、Ｒ^２１〜Ｒ^２４は同一でも異なっていてもよく、それぞれ水素原子または炭素数１〜２０の炭化水素基を表し、Ｒ^２１〜Ｒ^２４は構成単位毎に同一でも異なっていてもよい。］ Moreover, the polyvinyl ether compound which consists of a block copolymer or a random copolymer which has a structural unit represented by the said General formula (12) and a structural unit represented by the following General formula (13) is also used. Can do.

[In Formula (13), R ^{21 to} R ²⁴ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R ^{21 to} R ²⁴ are the same or different for each constituent unit. It may be. ]

R ^{16 to} R ¹⁸ in the general formula (12) each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms (preferably 1 to 4 hydrocarbon group), and they may be the same or different from each other. Good. Examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, an aryl group, an arylalkyl group, and the like. As R ^{15 to} R ¹⁸ , a hydrogen atom is preferable.

On the other hand, R ¹⁹ in the general formula (12) is a divalent hydrocarbon group having 1 to 10 carbon atoms (preferably 2 to 10) or a divalent ether bond oxygen-containing hydrocarbon group having 2 to 20 carbon atoms. Represents. Examples of the divalent hydrocarbon group having 1 to 10 carbon atoms include a divalent aliphatic chain hydrocarbon group, an alicyclic hydrocarbon group having two bonding sites on the alicyclic hydrocarbon, and a divalent aromatic group. Aromatic hydrocarbon group, alkyl aromatic hydrocarbon group, and the like. Among these, an aliphatic chain hydrocarbon group having 2 to 4 carbon atoms is particularly preferable.

Specific examples of the divalent ether bond oxygen-containing hydrocarbon group having 2 to 20 carbon atoms include methoxymethylene group, methoxyethylene group, methoxymethylethylene group, 1,1-bismethoxymethylethylene group, 1,2 Preferred examples include -bismethoxymethylethylene group, ethoxymethylethylene group, (2-methoxyethoxy) methylethylene group, (1-methyl-2-methoxy) methylethylene group, and the like. Incidentally, s in the general formula (15) represents a repeating number of ^{R 19} O, the average value thereof is 0 to 10, preferably a number in the range of 0-5. When the R ^{19 O} is more, the same configuration units, a plurality of R ^{19 O} may be the same or different.

Further, R ²⁰ in the general formula (12) represents a hydrocarbon group having 1 to ²⁰ carbon atoms, preferably 1 to 10 carbon atoms. Examples of such hydrocarbon groups include alkyl groups, cycloalkyl groups, aryl groups, and arylalkyls. Group, and the like. R ^{22 to} R ²⁶ may be the same or different for each structural unit.

  When the polyvinyl ether according to the present invention is a homopolymer composed only of the structural unit represented by the general formula (12), the carbon / oxygen atom number ratio is in the range of 4.2 to 7.0. preferable. If the atomic ratio is less than 4.2, the hygroscopicity becomes excessively high, and if it exceeds 7.0, the compatibility with the working medium tends to decrease.

In the general formula (13), R ^{21 to} R ²⁴ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

Examples of the hydrocarbon group having 1 to 20 carbon atoms, and hydrocarbon groups exemplified in the description of R ²⁰ in the general formula (12).

R ^{21 to} R ²⁴ may be the same or different for each structural unit.

  When the polyvinyl ether according to the present invention is a block copolymer or a random copolymer having a structural unit represented by the general formula (12) and a structural unit represented by the general formula (13), the carbon / oxygen The atomic ratio is preferably in the range of 4.2 to 7.0. If the atomic ratio is less than 4.2, the hygroscopicity becomes excessively high, and if it exceeds 7.0, the compatibility with the working medium tends to decrease.

  Furthermore, in this invention, the homopolymer which consists only of the structural unit represented by the said General formula (12), the structural unit represented by the said General formula (12), and the structure represented by the said General formula (13) Mixtures of block copolymers or random copolymers comprising units can also be used. These homopolymers and copolymers can be produced by polymerization of corresponding vinyl ether monomers and copolymerization of corresponding hydrocarbon monomers having olefinic double bonds and corresponding vinyl ether monomers.

［式（１４）中、Ｒ^２５〜Ｒ^２７は同一でも異なっていてもよく、それぞれ水素原子または炭素数１〜８の炭化水素基を表し、Ｒ^２８は炭素数１〜１０の２価の炭化水素基または炭素数２〜２０の２価のエーテル結合酸素含有炭化水素基を表し、Ｒ^２９は炭素数１〜２０の炭化水素基を表し、ｔはその平均値が０〜１０の数を表し、上記一般式（１４）で表される末端構造が複数のＲ^２８Ｏを有するとき、複数のＲ^２８Ｏはそれぞれ同一でも異なっていてもよい。］

［式（１５）中、Ｒ^３０〜Ｒ^３３は同一でも異なっていてもよく、それぞれ水素原子または炭素数１〜２０の炭化水素基を表す。］

［式（１６）中、Ｒ^３４〜Ｒ^３６は同一でも異なっていてもよく、それぞれ水素原子または炭素数１〜８の炭化水素基を表し、Ｒ^３７は炭素数１〜１０の２価の炭化水素基または炭素数２〜２０の２価のエーテル結合酸素含有炭化水素基を表し、Ｒ^３８は炭素数１〜２０の炭化水素基を表し、ｔはその平均値が０〜１０の数を表し、上記一般式（１６）で表される末端構造が複数のＲ^３７Ｏを有するとき、複数のＲ^３７Ｏはそれぞれ同一でも異なっていてもよい。］

［式（１７）中、Ｒ^３９〜Ｒ^４２は同一でも異なっていてもよく、それぞれ水素原子または炭素数１〜２０の炭化水素基を表す。］

［式（１８）中、Ｒ^４３〜Ｒ^４５は同一でも異なっていてもよく、それぞれ水素原子または炭素数１〜８の炭化水素基を表す。］ As the polyvinyl ether used in the present invention, one of the terminal structures is represented by the following general formula (14) or (15), and the other is represented by the following general formula (16) or (17). And those having one end represented by the general formula (14) or (15) and the other represented by the following general formula (18) are preferable.

[In the formula (14), R ^{25 to} R ²⁷ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and R ²⁸ is a divalent carbon atom having 1 to 10 carbon atoms. Represents a hydrogen group or a divalent ether-bonded oxygen-containing hydrocarbon group having 2 to 20 carbon atoms, R ²⁹ represents a hydrocarbon group having 1 to 20 carbon atoms, and t represents a number having an average value of 0 to 10. When the terminal structure represented by the general formula (14) has a plurality of R ²⁸ Os, the plurality of R ²⁸ Os may be the same or different. ]

[In the formula (15), R ^{30 to} R ³³ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. ]

[In the formula (16), R ^{34 to} R ³⁶ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and R ³⁷ is a divalent carbon atom having 1 to 10 carbon atoms. Represents a hydrogen group or a divalent ether-bonded oxygen-containing hydrocarbon group having 2 to 20 carbon atoms, R ³⁸ represents a hydrocarbon group having 1 to 20 carbon atoms, and t represents a number having an average value of 0 to 10. When the terminal structure represented by the general formula (16) has a plurality of R ³⁷ O, the plurality of R ³⁷ O may be the same or different. ]

[In formula (17), R ^{39 to} R ⁴² may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. ]

[In the formula (18), R ^{43 to} R ⁴⁵ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. ]

Among such polyvinyl ethers, the following are particularly suitable.
(I) One of the terminals has a structure represented by the general formula (14) or (15) and the other has the structure represented by the general formula (16) or (17), and R ¹⁶ in the general formula (12) -R ¹⁸ are all hydrogen atoms, s is a number from 0 to 4, R ¹⁹ is a divalent hydrocarbon group having 2 to 4 carbon atoms, and R ²⁰ is a carbon atom having 1 to ²⁰ carbon atoms. Being a hydrogen group;
(Ii) It has only the structural unit represented by the general formula (12), and one of the terminals has a structure represented by the general formula (14) and the other is represented by the general formula (15). R ^{16 to} R ¹⁸ in the general formula (12) are all hydrogen atoms, s is a number from 0 to 4, and R ¹⁹ is a divalent hydrocarbon group having 2 to 4 carbon atoms. And R ²⁰ is a hydrocarbon group having 1 to ²⁰ carbon atoms;
(Iii) One of the terminals has a structure represented by the general formula (14) or (15) and the other is represented by the general formula (16), and R ^{16 to} R ¹⁸ in the general formula (12) are All are hydrogen atoms, s is a number from 0 to 4, R ¹⁹ is a divalent hydrocarbon group having 2 to 4 carbon atoms, and R ²⁰ is a hydrocarbon group having 1 to ²⁰ carbon atoms. thing;
(Iv) It has only the structural unit represented by the general formula (12), and one of the terminals has a structure represented by the general formula (14) and the other is represented by the general formula (17). R ^{16 to} R ¹⁸ in the general formula (12) are all hydrogen atoms, s is a number from 0 to 4, and R ¹⁹ is a divalent hydrocarbon group having 2 to 4 carbon atoms. R ²⁰ is a hydrocarbon group having 1 to ²⁰ carbon atoms.

［式（１９）中、Ｒ^４６〜Ｒ^４８は同一でも異なっていてもよく、それぞれ水素原子または炭素数１〜８の炭化水素基を表し、Ｒ^４９およびＲ^５１は同一でも異なっていてもよく、それぞれ炭素数２〜１０の２価の炭化水素基を表し、Ｒ^５０およびＲ^５２は同一でも異なっていてもよく、それぞれ炭素数１〜１０の炭化水素基を表し、ｕおよびｖは同一でも異なっていてもよく、それぞれその平均値が０〜１０の数を表し、上記一般式（１９）で表される末端構造が複数のＲ^４９ＯまたはＲ^５１Ｏを有するとき、複数のＲ^４９ＯまたはＲ^５１Ｏは同一であっても異なっていてもよい。］ Moreover, in this invention, it has a structural unit represented by the said General formula (15), One of the terminal is represented by General formula (17), and the other is represented by following General formula (19). Polyvinyl ether compounds having a structure can also be used.

[In the formula (19), R ^{46 to} R ⁴⁸ may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, and R ⁴⁹ and R ⁵¹ may be the same or different. Each represents a divalent hydrocarbon group having 2 to 10 carbon atoms, R ⁵⁰ and R ⁵² may be the same or different, each represents a hydrocarbon group having 1 to 10 carbon atoms, and u and v may be the same They may be different, each having an average value of 0 to 10, and when the terminal structure represented by the general formula (19) has a plurality of R ⁴⁹ O or R ⁵¹ O, a plurality of R ⁴⁹ Os. Or R ⁵¹ O may be the same or different. ]

［式（２０）中、Ｒ^５３は炭素数１〜８の炭化水素基を示す。］

［式（２１）中、Ｒ^５４は炭素数１〜８の炭化水素基を示す。］

［式（２２）中、Ｒ^５５は炭素数１〜３のアルキル基を表し、Ｒ^５６は炭素数１〜８の炭化水素基を示す。］

［式（２３）中、Ｒ^５７は炭素数１〜８の炭化水素基を示す。］ Furthermore, in this invention, it consists of a structural unit represented by the following general formula (20) or (21), has a weight average molecular weight of 300 to 5,000, and one of the terminals is represented by the following general formula (22). Alternatively, a polyvinyl ether compound composed of a homopolymer or copolymer of an alkyl vinyl ether having a structure represented by (23) can also be used.

[In the formula (20), R ⁵³ represents a hydrocarbon group having 1 to 8 carbon atoms. ]

[In the formula (21), R ⁵⁴ represents a hydrocarbon group having 1 to 8 carbon atoms. ]

[In the formula (22), R ⁵⁵ represents an alkyl group having 1 to 3 carbon atoms, and R ⁵⁶ represents a hydrocarbon group having 1 to 8 carbon atoms. ]

[In the formula (23), R ⁵⁷ represents a hydrocarbon group having 1 to 8 carbon atoms. ]

The kinematic viscosity at 100 ° C. of the polyvinyl ether according to the present invention is preferably 5 to 20 mm ² / s, preferably 6 to 18 mm ² / s, more preferably 7 to 16 mm ² / s, and still more preferably 8 to 15 mm. ² / s, most preferably 10-15 mm ² / s. When the kinematic viscosity at 100 ° C. is less than the lower limit, the lubricity in the presence of the refrigerant becomes insufficient. On the other hand, when the upper limit is exceeded, the composition range showing compatibility with the refrigerant becomes narrow, and the refrigerant compression Machine lubrication and heat exchange in the evaporator are likely to be hindered. Moreover, kinematic viscosity at 40 ° C. of the polyvinyl ether is preferably a kinematic viscosity at 40 ° C. is 10 to 200 mm ² / s, more preferably 20 to 150 mm ² / s. If the kinematic viscosity at 40 ° C. is less than 10 mm ² / s, the lubricity and the sealing performance of the compressor tend to be reduced. If the kinematic viscosity exceeds 200 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 polyvinyl ether concerning this invention is -10 degrees C or less, and it is more preferable that it is -20--50 degreeC. If polyvinyl ether 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.

  Moreover, in the manufacturing process of the polyvinyl ether concerning this invention, a side reaction may occur and unsaturated groups, such as an allyl group, may be formed in a molecule | numerator. When an unsaturated group is formed in the polyvinyl ether molecule, the thermal stability of the polyvinyl ether itself is reduced, a polymer is produced and sludge is produced, or the antioxidant property (antioxidant property) is lowered. Phenomena such as generation of oxides are likely to occur. In particular, when a peroxide is generated, it decomposes to generate a compound having a carbonyl group, and the compound having a carbonyl group generates sludge, which easily causes capillary clogging.

  Accordingly, the polyvinyl ether according to the present invention is preferably one having a low degree of unsaturation derived from an unsaturated group or the like, specifically preferably 0.04 meq / g or less, and 0.03 meq / g or less. More preferably, it is most preferably 0.02 meq / g or less. The peroxide value is preferably 10.0 meq / kg or less, more preferably 5.0 meq / kg or less, and most preferably 1.0 meq / kg. Furthermore, the carbonyl value is preferably 100 ppm by weight or less, more preferably 50 ppm by weight or less, and most preferably 20 ppm by weight or less.

  The hydroxyl value is not particularly limited, but is desirably 10 mgKOH / g, preferably 5 mgKOH / g, and more preferably 3 mgKOH / g.

  The content of the polyvinyl ether in the refrigerating machine oil and working fluid composition for the refrigerating machine of the present invention is not particularly limited as long as the above excellent characteristics are not impaired, but is 50% by mass or more based on the total amount of refrigerating machine oil. It is preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more. If the content of the polyvinyl ether represented by the general formula (1) is less than 50% by mass, any of various performances such as lubricity, refrigerant compatibility, thermal / chemical stability, etc. of the refrigerating machine oil is unsatisfactory. It tends to be sufficient.

  In the refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention, the base oil may be composed only of an ether compound, but may further contain a base oil other than the ether compound.

  Base oils other than ether compounds include mineral oils, olefin polymers, naphthalene compounds, hydrocarbon oils such as alkylbenzenes, and ester base oils (monoesters, diesters, polyol esters, etc.), ketones, silicones, polysiloxanes, etc. A synthetic oil containing oxygen may be used in combination. Of the above, polyol esters are preferably used as the synthetic oil containing oxygen.

  In the refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention, the base oil containing the ether compound is blended with an amine salt of an acidic phosphate and an alicyclic epoxy compound. Furthermore, it can also be used in a form in which various additives are blended. In the following description, the additive content is shown based on the total amount of the refrigerating machine oil, but the content of these components in the refrigerating machine fluid composition is based on the total amount of the refrigerating machine oil composition. It is desirable to select so that it may become in the preferable range mentioned later.

  Examples of the amine salt of an acidic phosphate ester include an amine salt of an acidic phosphate ester and an amine having a primary or tertiary alkyl group having 1 to 24 carbon atoms, preferably 5 to 18 carbon atoms.

  Examples of the acidic phosphate ester constituting the amine salt of acidic phosphate ester 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, dipenty Acid phosphate, dihexyl acid phosphate, diheptyl acid phosphate, dioctyl acid phosphate, dinonyl acid phosphate, didecyl acid phosphate, diundecyl acid phosphate, didodecyl acid phosphate, ditridecyl acid phosphate, ditetradecyl acid didecate Examples include acid phosphate, dihexadecyl acid phosphate, diheptadecyl acid phosphate, dioctadecyl acid phosphate, and dioleyl acid phosphate.

  In addition, the amine constituting the acid phosphate ester salt includes linear or branched methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecyl. Amine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, oleylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptyl Amine, dioctylamine, dinonylamine, didecylamine, diundecylamine, didodecylamine, ditridecylamine, ditetradecylamine, dipentadecylamine, Hexadecylamine, diheptadecylamine, dioctadecylamine, dioleylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine And salts with amines such as triundecylamine, tridodecylamine, tritridecylamine, tritetradecylamine, tripentadecylamine, trihexadecylamine, triheptadecylamine, trioctadecylamine, and trioleylamine. The amine may be a single compound or a mixture of two or more compounds.

  In the refrigerating machine oil and working fluid composition for refrigerating machine of the present invention, the content of the amine salt of acidic phosphate is 400 mass ppm or more based on the total amount of refrigerating machine oil (based on the total amount of base oil and all blended additives). Preferably, it is 450-10000 mass ppm, More preferably, it is 500-5000 mass ppm. By setting the content of the amine salt of the acidic phosphate ester to 400 mass ppm or more, it is possible to ensure excellent lubricity.

  Moreover, the refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention contain an amine-based antioxidant. Examples of the amine antioxidant include phenyl-α-naphthylamines represented by the following formula (24), p, p′-dialkylated diphenylamine represented by the formula (25), and the like.

In the general formula ^{(24), R 58} represents a hydrogen atom or an alkyl group having 1 to 16 carbon atoms.
In General Formula (25), R ⁵⁹ and R ⁶⁰ each independently represent an alkyl group having 1 to 16 carbon atoms.

Among the compounds represented by the general formula (24), when R ⁵⁸ is an alkyl group, a more excellent sludge generation suppressing effect can be obtained. Therefore, R ⁵⁸ is a branched alkyl group having 8 to 16 carbon atoms. Further, a branched alkyl group having 8 to 16 carbon atoms derived from an oligomer of an olefin having 3 or 4 carbon atoms is more preferable. Specific examples of the olefin having 3 or 4 carbon atoms include propylene, 1-butene, 2-butene and isobutylene, but propylene or isobutylene is preferable in order to obtain a more excellent sludge formation suppressing effect. In order to obtain a further excellent sludge generation inhibiting effect, R ⁵⁸ is a branched octyl group derived from a dimer of isobutylene, a branched nonyl group derived from a trimer of propylene, and a trimer of isobutylene. A branched dodecyl group derived from a propylene tetramer, a branched dodecyl group derived from a propylene tetramer, or a branched pentadecyl group derived from a propylene pentamer is more preferred, and a branch derived from a dimer of isobutylene. A branched dodecyl group derived from a branched octyl group, a trimer of isobutylene, or a branched dodecyl group derived from a tetramer of propylene is more preferred, and a branched dodecyl group is most preferred.

R ⁵⁹ and R ⁶⁰ of the p, p′-dialkyldiphenylamine represented by the general formula (25) are each independently a branched alkyl group having 3 to 16 carbon atoms in order to obtain a more excellent sludge formation inhibiting effect. Further, a branched alkyl group having 3 to 16 carbon atoms derived from an olefin having 3 or 4 carbon atoms or an oligomer thereof is more preferable. Specific examples of the olefin having 3 or 4 carbon atoms include propylene, 1-butene, 2-butene, and isobutylene. Propylene or isobutylene is preferable in order to obtain a more excellent sludge generation suppressing effect.
Further, R ⁵⁹ or R ⁶⁰ is most preferably a tert-butyl group derived from isobutylene or a branched octyl group derived from a dimer of isobutylene in order to obtain a better antioxidant effect.

  As the p, p'-dialkyldiphenylamine represented by the general formula (25), a commercially available product or a synthesized product may be used. Similar to the phenyl-α-naphthylamine represented by the general formula (24), the synthesized product is a halogenated alkyl compound having 1 to 16 carbon atoms and diphenylamine, or an olefin having 2 to 16 carbon atoms or a carbon having 2 to 16 carbon atoms. Although it can be easily synthesized by reacting an olefin or an oligomer thereof with diphenylamine using a Friedel-Crafts catalyst, any synthesis method may be used.

  The upper limit of the content of the amine-based antioxidant is preferably 2% by mass based on the total amount of the composition, more preferably 1.5% by mass, and even more preferably 1% by mass. If the content exceeds 2% by mass, sludge is generated, which is not preferable. On the other hand, the lower limit of the content of the amine antioxidant is preferably 0.001% by mass, more preferably 0.05% by mass, and still more preferably 0.1% by mass based on the total amount of the composition. When the content of the antioxidant is less than 0.001% by mass, the antioxidant effect is insufficient, which is not preferable.

  Moreover, the refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention contain a metal deactivator. As the metal deactivator, benzotriazole or a derivative thereof is preferably used.

Benzotriazole is a compound represented by the following formula (26).

Examples of the benzotriazole derivative include alkylbenzotriazole represented by the following general formula (27), (alkyl) aminoalkylbenzotriazole represented by the following general formula (28), and the like.

In the general formula (27), R ⁶¹ represents a linear or branched alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group, and a represents 1 to 3, preferably 1 or 2. Examples of R ⁶¹ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. As the alkylbenzotriazole represented by the general formula (27), a compound in which R ⁶¹ is a methyl group or an ethyl group and a is 1 or 2 is particularly preferable from the viewpoint of excellent antioxidant properties. Examples thereof include benzotriazole (tolyltriazole), dimethylbenzotriazole, ethylbenzotriazole, ethylmethylbenzotriazole, diethylbenzotriazole, and mixtures thereof.

In the general formula (28), R ⁶² represents a linear or branched alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group, R ⁶³ represents a methylene group or an ethylene group, R ⁶⁴ and R ⁶⁵ is the same or different group, and represents a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms, preferably a linear or branched alkyl group having 1 to 12 carbon atoms, b represents 0 to 3, preferably 0 or 1.

Examples of R ⁶² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. R ⁶⁴ and R ⁶⁵ include a hydrogen atom, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-bull group, pentyl group, hexyl group, heptyl group, Examples thereof include alkyl groups such as octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group. R ⁶⁴ and R ⁶⁵ may be the same or different.

As the (alkyl) aminobenzotriazole represented by the general formula (28), R ⁶² is a methyl group, b is 0 or 1, R ⁶³ is a methylene group or an ethylene group, R is particularly excellent in the antioxidant property. Dialkylaminoalkylbenzotriazole, dialkylaminoalkyltolyltriazole, or a mixture thereof, in which ⁶⁴ and R ⁶⁵ are linear or branched alkyl groups having 1 to 12 carbon atoms, are preferably used.
Examples of these dialkylaminoalkylbenzotriazoles include dimethylaminomethylbenzotriazole, diethylaminomethylbenzotriazole, dipropylaminomethylbenzotriazole, dibutylaminomethylbenzotriazole, dipentylaminomethylbenzotriazole, dihexylaminomethylbenzotriazole, diheptyl. Aminomethylbenzotriazole, dioctylaminomethylbenzotriazole, N, N-bis (2-ethylhexyl) -methylbenzotriazole, dinonylaminomethylbenzotriazole, didecylaminomethylbenzotriazole, diundecylaminomethylbenzotriazole, didodecylamino Methylbenzotriazole; dimethylaminoethylbenzotriazole, Ethylaminoethylbenzotriazole, dipropylaminoethylbenzotriazole, dibutylaminoethylbenzotriazole, dipentylaminoethylbenzotriazole, dihexylaminoethylbenzotriazole, diheptylaminoethylbenzotriazole, dioctylaminoethylbenzotriazole, dinonylaminoethylbenzotriazole , Didecylaminoethylbenzotriazole, diundecylaminoethylbenzotriazole, didodecylaminoethylbenzotriazole; dimethylaminomethyltolyltriazole, diethylaminomethyltolyltriazole, dipropylaminomethyltolyltriazole, dibutylaminomethyltolyltriazole, dipentylaminomethyltolyl Triazole, dihex Ruaminomethyltolyltriazole, diheptylaminomethyltolyltriazole, dioctylaminomethyltolyltriazole, dinonylaminomethyltolyltriazole, didecylaminomethyltolyltriazole, diundecylaminomethyltolyltriazole, didodecylaminomethyltolyltriazole; Tolyltriazole, diethylaminoethyltolyltriazole, dipropylaminoethyltolyltriazole, dibutylaminoethyltolyltriazole, dipentylaminoethyltolyltriazole, dihexylaminoethyltolyltriazole, diheptylaminoethyltolyltriazole, dioctylaminoethyltolyltriazole, dinonylaminoethyl Tolyltriazole, didecylami Noethyltolyltriazole, diundecylaminoethyltolyltriazole, didodecylaminoethyltolyltriazole; or a mixture thereof.

  When the refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention contain a metal deactivator, the content is not particularly limited, but is usually 0.001 to 1.0% by mass based on the total amount of the refrigerating machine oil. Preferably, 0.005 to 0.5 mass% is more preferable. If the content of the metal deactivator is less than 0.001% by mass, the effect of the addition may not be sufficient. On the other hand, if the content exceeds 1.0% by mass, an effect of adding only the content can be obtained. This is not preferable because it is economically disadvantageous.

The refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention contain an alicyclic epoxy compound. As an alicyclic epoxy compound, the compound in which the carbon atom which comprises an epoxy group directly comprises the alicyclic ring like the compound represented by the following general formula (29) is mentioned.

Examples of the alicyclic epoxy compound include 1,2-epoxycyclohexane, 1,2-epoxycyclopentane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and bis (3,4-epoxycyclohexyl). Methyl) 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-methylcyclohexane, 4 -. epoxyethyl-1,2-epoxycyclohexane, and the like on SL alicyclic epoxy compound is 1 It may be used alone or in combination of two or more.

  When the refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention contains an alicyclic epoxy compound, the content is not particularly limited, but is usually 0.01 to 6.0% by mass based on the total amount of refrigerating machine oil. Is preferable, 0.05-5.0 mass% is more preferable, 0.10-4.0 mass% is still more preferable, 0.15-3.0 mass% is still more preferable, 0.20-2 0.0 mass% is most preferable. When the content of the alicyclic epoxy compound is less than 0.01% by mass, the effect of improving the heat and hydrolysis stability due to the addition of the alicyclic epoxy compound may not be sufficient. When exceeding, it is not preferable because insoluble matter may be precipitated.

  In the refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention, an alicyclic epoxy compound can be used alone, but an alicyclic epoxy compound and an epoxy compound other than the alicyclic epoxy compound are used. You may use together. As an epoxy compound other than the alicyclic epoxy compound, a phenyl glycidyl ether type epoxy compound, a glycidyl ester type epoxy compound, an epoxidized fatty acid monoester, and the like are preferable, and a glycidyl ester type epoxy compound is more preferable.

  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, zinc dithiophosphate, antiwear agents such as phosphorus compounds other than the present application, chlorinated paraffin, sulfur compounds and the like. Extreme pressure agents, oily agents such as fatty acids, silicone-based antifoaming 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 500 mm ² / s, and most preferably 5 to 400 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.

  Moreover, the water content of the refrigerating machine oil of the present invention is not particularly limited, but can be preferably 500 ppm by mass or less, more preferably 300 ppm by mass or less, and most preferably 200 ppm by mass 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 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 ash content of the refrigerating machine oil of the present invention is not particularly limited. However, 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, it is preferably 100 ppm by mass or less, more preferably 50 masses ppm or less. In the present invention, 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 refrigerator oil of the present invention is used together with an unsaturated fluorinated hydrocarbon refrigerant, and the working fluid composition for a refrigerator of the present invention contains an unsaturated fluorinated hydrocarbon refrigerant.

As the unsaturated fluorinated hydrocarbon refrigerant, an unsaturated fluorinated hydrocarbon having 3 to 5 fluorine atoms is preferable, and 1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,3,3 , 3-tetrafluoropropene (HFO-1234ze), 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,2,3,3-tetrafluoropropene (HFO - 1234ye), and 3,3 , 3-trifluoropropene (HFO-1243zf) is preferably one or a mixture of two or more. From the viewpoint of the physical properties of the refrigerant, one or more selected from HFO-1225ye, HFO-1234ze, and HFO-1234yf are preferable.

  The refrigerant used in the present invention may be a mixed refrigerant of an unsaturated fluorinated hydrocarbon 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 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 fluorine-containing 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 unsaturated fluorinated hydrocarbon refrigerants (hereinafter referred to as “refrigerant (A)”), saturated hydrofluorocarbon, Contains at least one selected from hydrocarbons having 3 to 5 carbon atoms, dimethyl ether, carbon dioxide, bis (trifluoromethyl) sulfide, and trifluoroiodomethane refrigerant (hereinafter referred to as “refrigerant (B)”). It is preferable to do.

  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 unsaturated fluorinated hydrocarbon refrigerant or saturated hydrofluorocarbon, You may further contain natural refrigerants, such as fluorine-containing ether refrigerant | coolants, such as a bar fluoro ether, hydrocarbons other than C3-C5 hydrocarbon, or ammonia.

  The refrigerating machine oil of the present invention is usually present in the form of a refrigerating machine fluid composition mixed with an unsaturated fluorinated hydrocarbon refrigerant or 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 in 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 hot water heater, a freezer, a freezer / refrigerator 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 further more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

[Examples 1-46, Comparative Examples 1-10]
In Examples 1 to 46 and Comparative Examples 1 to 10, refrigerator oils were prepared using the base oils and additives shown below, respectively. Various properties of the obtained refrigerating machine oil are shown in Tables 1 to 26 .

(Base oil)
Base oil 1: polyethylene propylene glycol monomethyl ether.
Base oil 2: polypropylene glycol dimethyl ether.
Base oil 3: polyvinyl ether.
(Additive)
A1: oleylamine salt of di (2-ethylhexyl) acid phosphate A2: 2-ethylhexylamine salt of dioctyl acid phosphate A3: mono (C11-C14 mixed alkyl) amine salt of dihexyl acid phosphate B1: dioctyldiphenylamine B2: dinonyldiphenylamine B3 : Octylphenyl α-naphthylamine C1: Benzotriazole C2: N, N-bis (2-ethylhexyl) -methylbenzotriazole D1: 1,2-epoxycyclohexane D2: 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxy Rate D3: 4- (1′-methylepoxyethyl) -1,2-epoxy-2-methylcyclohexane a1: tricresyl phosphate a2: di (2-ethylhexyl) ) Acid phosphate a3: Dilauryl hydrogen phosphite b1: 2,6-di-t-butyl-p-cresol b2: 3,5-bis (1,1-dimethyl-ethyl) -4-hydroxy-benzenepropanoic acid C7-C9 branched alkyl ester c1: 2,5-bis (alkyldithio) 1,3,4-thiadiazole d1: pt-butylphenyl glycidyl ether d2: glycidyl-2, 2'-dimethyloctanoate d3: 1 , 2-Epoxyoctadecane

  Next, the following evaluation tests were carried out for each of the refrigerating machine oils of Examples 1 to 46 and Comparative Examples 1 to 10.

(Evaluation of thermal and chemical stability)
30 ml of sample oil (initial hue L0.5) adjusted to a water content of 100 mass ppm or less, 30 g of 2,3,3,3-tetrafluoropropene, and catalyst (iron, copper, and aluminum wires) in 200 ml of stainless steel After enclosing in the autoclave made, it was heated to 175 ° C. and held for 2 weeks for testing. After the test, the hue, acid value, fluorine ion amount, and catalyst appearance change of the refrigerator oil composition were measured. The obtained results are shown in Tables 1-6.

(Evaluation of lubricity)
In accordance with ASTM D2670, while blowing 2,3,3,3-tetrafluoropropene 10L / h into the sample oil, the test is conducted for one hour at an oil temperature of 80 ° C. and a load of 250 LB, and the amount of pin wear after the test is measured. did. The obtained results are shown in Tables 1-6.

Claims (5)

A base oil containing an ether compound, an amine salt of an acidic phosphate, an amine antioxidant, a metal deactivator and a refrigeration oil containing an alicyclic epoxy compound;
An unsaturated fluorinated hydrocarbon refrigerant;
Containing
The working fluid composition for a refrigerating machine, wherein the content of the amine salt of the acidic phosphate is 400 mass ppm or more and 5000 mass ppm or less based on the total amount of the refrigerating machine oil.   As the unsaturated fluorinated hydrocarbon refrigerant, 1,2,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene, 1, The working fluid composition for a refrigerator according to claim 1, comprising at least one selected from 2,3,3-tetrafluoropropene and 3,3,3-trifluoropropene.   It further contains at least one selected from saturated hydrofluorocarbons, hydrocarbons having 3 to 5 carbon atoms, dimethyl ether, carbon dioxide, bis (trifluoromethyl) sulfide, and trifluoroiodomethane refrigerant, Item 3. A working fluid composition for a refrigerator according to Item 1 or 2.   The unsaturated fluorinated hydrocarbon refrigerant is 1,2,3,3,3-pentafluoropropene, 1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene, 1, At least one selected from 2,3,3-tetrafluoropropene and 3,3,3-trifluoropropene, and the saturated hydrofluorocarbon is difluoromethane, pentafluoroethane, 1,1,2,2-tetra Fluoroethane, 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 It is at least one selected from 3,3-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, wherein Contains a base oil containing an ether compound, an amine salt of an acidic phosphate ester, an amine antioxidant, a metal deactivator and an alicyclic epoxy compound,
The content of the amine salt of the acidic phosphate is 400 mass ppm or more and 5000 mass ppm or less based on the total amount of refrigerating machine oil,
A refrigerating machine oil characterized by being used together with an unsaturated fluorinated hydrocarbon refrigerant.