JP5546917B2 - 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. 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 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. In particular, in a car air conditioner, it is advantageous if the polyalkylene glycol used for R134a can be diverted as it is. However, according to the study by the present inventors, refrigerant compatibility and refrigerant stability cannot be achieved at a high level simply by diverting these conventional polyalkylene glycol refrigeration oils as they are to the system.

  The present invention has been made in view of such circumstances, and in a refrigeration system using an unsaturated fluorinated hydrocarbon refrigerant, a refrigerating machine oil capable of achieving a high level of refrigerant compatibility and refrigerant stability, and It is an object to provide a working fluid composition for a refrigerator.

  As a result of intensive studies to achieve the above object, the present inventors have obtained sufficient compatibility and stability with a refrigerant in the presence of an unsaturated fluorinated hydrocarbon refrigerant by using a specific polyalkylene glycol. The present inventors have found that a refrigerating machine oil having can be realized, and have completed the present invention.

That is, the present invention provides the following general formula (1):
R _1- (OR ₃ ) _n -OR ₂ (1)
[Wherein, R ₁ and R ₂ may be the same or different and each represents hydrogen, an alkyl group, an acyl group, an aromatic group or an alicyclic hydrocarbon group, and at least one of R ₁ and R ₂ is aromatic. Or an alicyclic hydrocarbon group, R ₃ represents an alkylene group having 2 to 4 carbon atoms, and n represents the number of repeating oxyalkylene groups represented by OR ₃ . ]
Providing a refrigerating machine oil, the refrigerant consisting of unsaturated fluorinated hydrocarbon, a refrigerant working fluid composition characterized by containing the containing polyalkylene glycol represented in more than 50 wt% total amount of the refrigerating machine oil based To do.

Further, the present invention includes a polyalkylene glycol represented by the above general formula (1) in an amount of 50% by mass or more based on the total amount of refrigerating machine oil , and is used together with a refrigerant composed of an unsaturated fluorinated hydrocarbon. Provide machine oil.

  The working fluid composition for refrigerators according to the present invention includes 1,2,3,3,3-pentafluoropropene (HFO-1225ye), 1,3,3,3-tetrafluoro as unsaturated fluorinated hydrocarbon refrigerants. Propene (HFO-1234ze), 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,2,3,3-tetrafluoropropene (HFC1234ye) and 3,3,3-trifluoropropene (HFO) It is preferable to contain at least one selected from −1243zf).

  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.

  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 contains a polyalkylene glycol represented by the following general formula (1) (hereinafter sometimes referred to as “polyalkylene glycol according to the present invention”) and is used together with an unsaturated fluorinated hydrocarbon refrigerant. It is characterized by being able to. The working fluid composition for a refrigerator according to the present invention is characterized by containing a polyalkylene glycol represented by the following general formula (1) and an unsaturated fluorinated hydrocarbon 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 an unsaturated fluorinated hydrocarbon refrigerant.
R _1- (OR ₃ ) _n -OR ₂ (1)
[Wherein, R ₁ and R ₂ may be the same or different and each represents hydrogen, an alkyl group, an acyl group, an aromatic group or an alicyclic hydrocarbon group, and at least one of R ₁ and R ₂ is aromatic. Or an alicyclic hydrocarbon group, R ₃ represents an alkylene group having 2 to 4 carbon atoms, and n represents the number of repeating oxyalkylene groups represented by OR ₃ . ]

In the above formula (1), R ₁ and R ₂ may be the same or different and each represents hydrogen, an alkyl group, an aromatic group or an alicyclic hydrocarbon group. At least one of R ₁ and R ₂ is an aromatic group or an alicyclic hydrocarbon group. As the alkyl group, those having 1 to 5 carbon atoms are preferably used, methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, linear or branched And a pentyl group having a shape. As the acyl group, those having 2 to 5 carbon atoms are preferably used. Specifically, an acetyl group, a linear or branched propanoyl group, a linear or branched butanoyl group, a linear or Examples thereof include a branched pentanoyl group.
As an aromatic group, a phenyl group, a phenyl group having 1 to 3 alkyl groups having 1 to 6 carbon atoms, an alkylphenyl group, a naphthyl group, and an alkyl naphthyl group having 1 to 6 alkyl groups having 1 to 6 carbon atoms Is mentioned. Specifically, phenyl group, cresyl group, ethylphenyl group, n-propylphenyl group, i-propylphenyl group, n-butylphenyl group, i-butylphenyl group, t-butylphenyl group, n-pentylphenyl group I-pentylphenyl group, n-hexylphenyl group, i-hexylphenyl group; xylenyl group, methylethylphenyl group, methylpropylphenyl group, diethylphenyl group, ethylpropylphenyl group; trimethylphenyl group; naphthyl group, methylnaphthyl Group, dimethylnaphthyl group, methylethylnaphthyl group and the like.
As the alicyclic hydrocarbon group, cyclopentyl group, cyclohexyl group, 5-membered ring and 6-membered ring having 1 to 3 alkyl groups having 1 to 6 carbon atoms are preferably used, and specifically, cyclopentyl group , Alkylcyclopentyl group, cyclohexyl group, and alkylcyclohexyl group. More specifically, examples include a methylcyclopentyl group, a dimethylcyclopentyl group, a methylethylcyclopentyl group, a diethylcyclopentyl group; a methylcyclohexyl group, a dimethylcyclohexyl group, a methylethylcyclohexyl group, and a diethylcyclohexyl group.
Among these groups, from the viewpoint of compatibility with the refrigerant, hydrogen, methyl group, ethyl group, linear or branched propyl group, linear or branched butyl group, acetyl group, linear Or a branched propanoyl group, a linear or branched butanoyl group, a phenyl group, or a C1-C4 alkyl-substituted phenyl group is more preferable, and hydrogen, a methyl group, an ethyl group, an acetyl group, a phenyl group, a C1- A C4 alkyl-substituted phenyl group is more preferable, and hydrogen, a methyl group or an acetyl group, a phenyl group, and a C1-C4 alkyl-substituted phenyl group are most preferable. If at least _one of R ₁ and R ₂ is not an aromatic group or an alicyclic hydrocarbon group, the refrigerant stability is poor, which is not preferable. When the number of carbon atoms of the alkyl group and acyl group exceeds 5, the composition range showing compatibility with the refrigerant becomes narrow, and the lubrication of the refrigerant compressor is liable to be poor and heat exchange in the evaporator is liable to occur. The hydroxyl value is not particularly limited, but is preferably 200 to 100 mgKOH / g from the viewpoint of refrigerant stability, 100 mgKOH / g or less, preferably 50 mgKOH / g or less, more preferably from the viewpoint of refrigerant compatibility. It is desirable that it is 30 mgKOH / g or less, most preferably 10 mgKOH / g or less.

Further, in the above general formula (1), _{R 3} represents an alkylene group having 2 to 4 carbon atoms. Specific examples of such an alkylene group include an ethylene group (—CH ₂ CH ₂ —), a propylene group (—CH (CH ₃ ) CH ₂ —), and a trimethylene group (—CH ₂ CH ₂ CH ₂ —). , Butylene group (—CH (CH ₂ CH ₃ ) CH ₂ —), tetramethylene group (—CH ₂ CH ₂ CH ₂ CH ₂ —) and the like. Among these alkylene groups, an ethylene group, a propylene group, a butylene group, and a tetramethylene group are more preferable. Further, the proportion of the alkylene group having 2 carbon atoms in the entire R3 is preferably 30% by weight or less, preferably 25% by weight or less, and more preferably 20% by weight or less from the viewpoint of refrigerant compatibility.

Furthermore, in said general formula (1), n represents the repeating number (polymerization degree) of the oxyalkylene group represented by OR < ₃ >, and the ratio of the alkylene group of 2 carbon atoms which occupies n R < ₃ > is 30 mol%. It is as follows. The number average molecular weight of the polyalkylene glycol represented by the formula (1) is preferably 500 to 3000, more preferably 600 to 2000, and more preferably 600 to 1500, and n is the number average molecular weight of the polyalkylene glycol. Is a number that 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. preferable. When Mw / Mn exceeds 1.20, the compatibility between the unsaturated fluorinated hydrocarbon refrigerant and the refrigerating machine oil tends to be insufficient.

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 to 14 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 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.

  The refrigerating machine oil of the present invention may consist only of the polyalkylene glycol according to the present invention, but may further contain a base oil other than the polyol ester and various additives. Moreover, the working fluid composition for a refrigerator of the present invention may further contain a base oil and various additives other than the polyalkylene glycol according to the present invention. In the following description, the contents of the base oil and additives other than the polyalkylene glycol according to the present invention are shown based on the total amount of refrigerating machine oil, but the content of these components in the refrigerating machine fluid composition is When the total amount of refrigerating 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 polyalkylene glycol according to the present invention include mineral oils, olefin polymers, naphthalene compounds, hydrocarbon oils such as alkylbenzene, and ester base oils (monoesters, diesters, polyol esters, etc.), other than the present invention 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 the 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 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 amine constituting the acid phosphate ester salt include linear or branched methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, Dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, oleylamine, tetracosylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, Diheptylamine, dioctylamine, dinonylamine, didecylamine, diundecylamine, didodecylamine, ditridecylamine, ditetradecylamine, dipenta Silamine, dihexadecylamine, diheptadecylamine, dioctadecylamine, dioleylamine, ditetracosylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine , Trinonylamine, tridecylamine, triundecylamine, tridodecylamine, tritridecylamine, tritetradecylamine, tripentadecylamine, trihexadecylamine, triheptadecylamine, trioctadecylamine, trioleylamine tritetra And salts with amines such as cosylamine. The amine may be a single compound or a mixture of two or more compounds.

  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.

  Further, the refrigerating machine oil and the working fluid composition for the refrigerating machine according to 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 allyl oxirane compound, an alkyl oxirane 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 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 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.

  Further, the water content of the refrigerating machine oil of the present invention is not particularly limited, but can be preferably 500 ppm or less, more preferably 300 ppm or less, and most preferably 200 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 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, 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, 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 (HFC1234ye), and 3,3,3 -It is preferable that it is any 1 type, or a mixture of 2 or more types of trifluoropropene (HFO-1243zf). 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 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 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 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 to 11 and Comparative Examples 1 to 3]
In Examples 1 to 11 and Comparative Examples 1 to 3, refrigerating machine oils were prepared using base oils 1 to 11 and additives 1 to 3 shown below, respectively. Various properties of the obtained refrigerator oil are shown in Tables 1 to 3.

(Base oil)
Base oil 1: a polyalkylene glycol represented by the general formula (1), wherein R ₁ is a phenyl group, R ₂ is hydrogen,-(OR ₃ ) _n -is an oxypropylene chain, and has an average molecular weight of 800 Base oil 2: polyalkylene represented by the general formula (1), R ₁ is a phenyl group, R ₂ is a methyl group,-(OR ₃ ) _n -is an oxypropylene chain, and has an average molecular weight of 1000 Glycol base oil 3: represented by the general formula (1), R ₁ is a pt-butylphenyl group, R ₂ is hydrogen,-(OR ₃ ) _n -is an oxypropylene chain, and an average molecular weight 700, polyalkylene glycol base oil 4: represented by the general formula (1), R ₁ is a pt-butylphenyl group, R ₂ is a methyl group, and — (OR ₃ ) _n — is oxypropylene Chain, average molecular weight Polyalkylene glycol base oil 5 50: represented by general formula (1), _{R 1} is p-t-butylphenyl group, _{R 2} is hydrogen, - _{(OR 3) n} - is oxypropylene Polyalkylene glycol base oil 6 which is an oxybutylene random copolymer chain and has an average molecular weight of 900: represented by the general formula (1), R ₁ is a pt-butylphenyl group, and R ₂ is a methyl group , — (OR ₃ ) _n — is an oxypropylene / oxybutylene random copolymer chain, polyalkylene glycol base oil 7 having an average molecular weight of 900: represented by the general formula (1), and R ₁ is p-t-butyl a phenyl group, _{R 2} is a phenyl group, - _{(OR 3) n} - is oxypropylene chain, the average molecular weight of 900 polyalkylene glycol base oil 8: formula (1) Represented, R ₁ is cyclohexyl group, R ₂ is a methyl group, _- (OR ₃₎ n - is oxypropylene chain, the average molecular weight of 950 polyalkylene glycol base oil 9: Polyethylene glycol dimethyl ether group Oil 10: Polypropylene glycol dimethyl ether base oil 11: Polypropylene glycol butyl methyl ether (additive)
Additive 1: p-tert-butylphenylglycidyl ether additive 2: tricresyl phosphate additive 3: 2,6-di-tert-butyl-p-cresol

  Next, the following evaluation tests were carried out for each of the refrigerating machine oils of Examples 1 to 11 and Comparative Examples 1 to 3.

(Evaluation of refrigerant compatibility)
In accordance with JIS-K-2211 “Refrigerating machine oil” “Compatibility test method with refrigerant”, 1 g of refrigerating machine oil is blended with 19 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 Tables 1-3. In Tables 1 to 3, “compatible” means that the refrigerant and the refrigerating machine oil are dissolved in each other, and “separation” means that the refrigerant and the refrigerating machine oil are separated into two layers.

(Evaluation of thermal and chemical stability)
After enclosing 30 g of refrigerating machine oil (initial hue L0.5) whose water content was adjusted to 1000 ppm, 30 g of 2,3,3,3-tetrafluoropropene and catalyst (each wire of iron, copper, and aluminum) in an autoclave, Tested by heating to 175 ° C and holding for 1 week. After the test, the hue and acid value of the refrigerator oil composition were evaluated. Hue was evaluated according to ASTM D156. The obtained results are shown in Tables 1-3.

  As is clear from the results shown in Tables 1 to 3, the refrigeration oils of Examples 1 to 11 are excellent in refrigerant stability and refrigerant compatibility when used together with the unsaturated fluorinated hydrocarbon refrigerant. Recognize.

  The refrigerating machine oil and the working fluid composition for a refrigerating machine of the present invention can achieve refrigerant compatibility and refrigerant stability at a high level in a refrigerating system using an unsaturated fluorohydrocarbon refrigerant, and can be used for the reliability of refrigerating and air-conditioning equipment. This is useful in that the property can be improved.

Claims (3)

Refrigerating machine oil containing 50% by mass or more of the polyalkylene glycol represented by the following general formula (1) based on the total quantity of refrigerating machine oil ;
A refrigerant comprising an unsaturated fluorohydrocarbon ;
A working fluid composition for a refrigerator, comprising:
R _1- (OR ₃ ) _n -OR ₂ (1)
[Wherein, R ₁ and R ₂ may be the same or different and each represents hydrogen, an alkyl group, an acyl group, an aromatic group or an alicyclic hydrocarbon group, and at least one of R ₁ and R ₂ is aromatic. Or an alicyclic hydrocarbon group, R ₃ represents an alkylene group having 2 to 4 carbon atoms, and n represents the number of repeating oxyalkylene groups represented by OR ₃ . ]   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. A refrigerating machine oil comprising a polyalkylene glycol represented by the following general formula (1) in an amount of 50% by mass or more based on the total amount of refrigerating machine oil and used together with a refrigerant composed of an unsaturated fluorinated hydrocarbon.
R _1- (OR ₃ ) _n -OR ₂ (1)
[Wherein, R ₁ and R ₂ may be the same or different and each represents hydrogen, an alkyl group, an acyl group, an aromatic group or an alicyclic hydrocarbon group, and at least one of R ₁ and R ₂ is aromatic. Or an alicyclic hydrocarbon group, R ₃ represents an alkylene group having 2 to 4 carbon atoms, and n represents the number of repeating oxyalkylene groups represented by OR ₃ . ]