JP2627564C - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a refrigerating machine oil for a non-chlorinated chlorofluorocarbon refrigerant, and more specifically, contains an ester having a specific structure as a main component and contains a specific epoxy resin. The present invention relates to a refrigerating machine oil for a non-chlorinated chlorofluorocarbon refrigerant excellent in various performances. [Prior art] Conventionally, as a refrigerating machine oil, naphthenic mineral oil, paraffin mineral oil, alkylbenzene, polyglycol oil having a kinematic viscosity at 40 ° C of 10 to 200 cSt,
Ester oils and mixtures thereof, or mixtures of these various base oils with additives are generally used. On the other hand, CFC-11, CFC-12, CFC-113, HCFC-22, and the like are used as a CFC-based refrigerant used in a refrigerator. Among these CFC-based refrigerants, CFC-11, CFC-12, and CFC-113
Fluorocarbons in which all the hydrogens of such hydrocarbons are replaced by halogens containing chlorine are subject to regulation because they lead to ozone depletion. Therefore, HFC-134a
And non-chlorinated chlorofluorocarbons such as HFC-152a are being used as substitutes for CFCs. In particular, HFC-134a is not suitable for use in many refrigerators such as home refrigerators and air conditioners. It has similar mechanical properties and is a promising alternative refrigerant. Although refrigerating machine oils have various required performances, compatibility with a refrigerant is extremely important in terms of lubrication and system efficiency of the refrigerating machine. However, naphthenic mineral oils,
Refrigeration oils based on paraffinic mineral oils, alkylbenzenes and conventionally known ester oils have almost no compatibility with non-chlorinated chlorofluorocarbons such as HFC-134a, and therefore, when used in combination with HFC-134a. , Two-layer separation occurs at normal temperature, and the most important oil return property in the refrigeration system deteriorates, and the refrigeration efficiency decreases or lubricity deteriorates, causing various practical problems such as seizure of the compressor And cannot withstand use. Polyglycols are also known as refrigerating machine oils having a high viscosity index, for example, JP-B-57-42119, JP-B-61-528.
No. 80 and JP-A-57-51795. However, the polyglycol oils specifically disclosed in these prior arts still use HFC-13.
Since the compatibility with 4a is not sufficient, the same problem as described above occurs, and it cannot be used practically. U.S. Pat. No. 4,755,316 discloses a polyglycol-based refrigerator oil compatible with HFC-134a. Further, the present inventors have proposed that HFC-1
A polyglycol-based refrigerating machine oil, which has much higher compatibility with 34a than conventional known refrigerating machine oils, has been previously developed and has already been filed (Japanese Patent Application Laid-Open Nos. 1-256594 and 1-271491). Gazette). However, it has been found that polyglycol-based oils have problems of high solubility in water and poor electrical insulation. On the other hand, refrigerating machine oil used for compressors such as home refrigerators requires high electrical insulation. Among known refrigerating machine oils, those having the highest insulating properties are alkylbenzenes and mineral oils. However, as described above, alkylbenzenes and mineral oils have almost no compatibility with non-chlorinated Freon such as HFC-134a. Therefore, a refrigerating machine oil having both high compatibility with non-chlorinated chlorofluorocarbons such as HFC-134a and high insulating properties has not yet appeared. The present inventors have repeated research to develop a refrigerating machine oil that can meet the above requirements,
Refrigeration oil containing a specific epoxy compound as an essential component in an ester having a specific structure has excellent compatibility with non-chlorinated chlorofluorocarbons such as HFC-134a and has high electric insulation, and further excellent lubrication They have found that they have properties and stability, and have completed the present invention. [Problems to be Solved by the Invention] The present invention is excellent in compatibility with non-chlorofluorocarbons such as HFC-134a containing an ester having a specific structure as a main component and a specific epoxy compound as an essential component, and An object of the present invention is to provide a lubricating oil for non-chlorinated Freon refrigerant having high electrical insulation and stability. [Means for Solving the Problems] That is, the present invention provides the following (1) to (4) non-chlorinated chlorofluorocarbon refrigerant refrigerating machine oils. (1) General formula Wherein R ₁ and R ₇ are divalent hydrocarbon groups having 1 to 8 carbon atoms, R ₂ and R ₄ are divalent saturated hydrocarbon groups having 2 to 16 carbon atoms, ₃ and R ₈ each represent an alkyl group having 1 to 15 carbon atoms; R ₅ and R ₆ each represent an alkyl group having 1 to 14 carbon atoms; 1 and m are 0 or 1; And a phenyl glycidyl ether type epoxy compound, a glycidyl ester type epoxy compound, an epoxidized fatty acid monoester and an epoxidized vegetable oil, based on the total amount of the refrigerator oil. A refrigerating machine oil for a non-chlorinated Freon refrigerant, comprising as an essential component 0.1 to 5.0% by weight of at least one epoxy compound selected from the group. However,
This excludes the case where an ester having all of the following (a) to (c) in the same molecule as a base oil is contained in the same molecule. (A) an aliphatic polyhydric alcohol having 1 to 6 primary hydroxy groups (b) a linear or branched saturated aliphatic monocarboxylic acid having 2 to 9 carbon atoms or a derivative thereof (c) having 2 to 10 carbon atoms Linear or branched saturated aliphatic dicarboxylic acid or derivative thereof (2) Phosphoric acid ester, acidic phosphoric acid ester, amine salt of phosphoric acid ester, chlorinated phosphoric acid ester and phosphite ester, based on the total amount of refrigerator oil The refrigerating machine oil for a non-chlorinated Freon refrigerant according to claim 1, comprising 0.1 to 5.0% by weight of at least one phosphorus compound selected from the group consisting of: (3) General formula Wherein R ₁ and R ₇ are divalent hydrocarbon groups having 1 to 8 carbon atoms, R ₂ and R ₄ are divalent saturated hydrocarbon groups having 2 to 16 carbon atoms, ₃ and R ₈ each represent an alkyl group having 1 to 15 carbon atoms; R ₅ and R ₆ each represent an alkyl group having 1 to 14 carbon atoms; 1 and m are 0 or 1; The ester has a number average molecular weight of 300 to 2,000 represented by the following formula, and a volume resistivity at 25 ° C. of 1.1 × 10 ¹⁴ Ω · cm or more as a main component. As an essential component, 0.1 to 5.0% by weight of at least one epoxy compound selected from the group consisting of glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, epoxidized fatty acid monoesters and epoxidized vegetable oils. Refrigeration oil for non-chlorinated CFC refrigerants. However, this excludes the case where an ester having all of the following (a) to (c) in the same molecule as a base oil is contained in the same molecule. (A) an aliphatic polyhydric alcohol having 1 to 6 primary hydroxy groups (b) a linear or branched saturated aliphatic monocarboxylic acid having 2 to 9 carbon atoms or a derivative thereof (c) having 2 to 10 carbon atoms Linear or branched saturated aliphatic dicarboxylic acid or derivative thereof (4) General formula Wherein R ₁ and R ₇ are divalent hydrocarbon groups having 1 to 8 carbon atoms, R ₂ and R ₄ are divalent saturated hydrocarbon groups having 2 to 16 carbon atoms, ₃ and R ₈ each represent an alkyl group having 1 to 15 carbon atoms; R ₅ and R ₆ each represent an alkyl group having 1 to 14 carbon atoms; 1 and m are 0 or 1; And a number average molecular weight of 200 to 3,000, and a volume resistivity at 25 ° C. of 1.
1 × 10 ¹⁴ Ω · cm or more and a kinematic viscosity at 100 ° C. of 2 to 150 cS
at least one epoxy compound selected from the group consisting of a phenylglycidyl ether type epoxy compound, a glycidyl ester type epoxy compound, an epoxidized fatty acid monoester, and an epoxidized vegetable oil, based on the total amount of the refrigerator oil. 1. A refrigerating machine oil for non-chlorinated CFC refrigerants, which contains 0.1 to 5.0% by weight as an essential component. However, in the same molecule, the following (a) to (c)
) Is excluded as a base oil containing an ester having all of the constituents. (A) an aliphatic polyhydric alcohol having 1 to 6 primary hydroxy groups (b) a linear or branched saturated aliphatic monocarboxylic acid having 2 to 9 carbon atoms or a derivative thereof (c) having 2 to 10 carbon atoms Linear or branched saturated aliphatic dicarboxylic acid or derivative thereof [Embodiment of the Invention] Hereinafter, the content of the present invention will be described in more detail. The refrigerating machine oil of the present invention has a general formula The main component is an ester represented by And a group represented by However, this excludes the case where an ester having all of the following (a) to (c) in the same molecule as a base oil is contained in the same molecule. (A) an aliphatic polyhydric alcohol having 1 to 6 primary hydroxy groups (b) a linear or branched saturated aliphatic monocarboxylic acid having 2 to 9 carbon atoms or a derivative thereof (c) having 2 to 10 carbon atoms A linear or branched saturated aliphatic dicarboxylic acid or a derivative thereof; R ₁ and R _{7 each} represent a divalent hydrocarbon group having 1 to 8, preferably 1 to 6 carbon atoms;
₂ and R ₄ are 2 to 16 carbon atoms, a divalent saturated hydrocarbon group having preferably 2 to 9, R ₃
And R ₈ are an alkyl group having 1 to 15, preferably 1 to 12 carbon atoms, R ₅ and R ₆
Represents an alkyl group having 1 to 14 carbon atoms, preferably 1 to 11 carbon atoms. Further, 1 and m each represent a number of 0 or 1, and n represents an integer of 0 to 30, preferably 1 to 30. It is not preferable to use an ester that does not satisfy the above conditions as a main component because the compatibility with the hydrogen-containing chlorofluorocarbon is inferior. Specific examples of R ₁ and R ₇ include a methylene group, an ethylene group, a propylene group, a trimethylene group, a butylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, and a phenylene group. And other unsaturated groups. Examples of R ₂ and R ₄ include, in addition to the above-mentioned alkylene group (excluding the methylene group), a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group, a tridecamethylene group, Examples thereof include a tetradecamethylene group, a pentadecamethylene group, a hexadecamethylene group, and a cyclohexylene group. Also, R ₅
And R ₆ are, specifically, a methyl group, an ethyl group, a propyl group, a butyl group,
Examples of a linear or branched alkyl group such as a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group and a tetradecyl group, and R ₃ and R ₈ are And a linear or branched alkyl group such as a pentadecyl group in addition to the above alkyl groups. In the present invention, the above ester may be used alone or as a mixture of two or more. Further, the molecular weight of the ester in the present invention is not particularly limited, but those having a number average molecular weight of 200 to 3000 are preferably used from the viewpoint of further improving the sealing property of the compressor, and the number average molecular weight is 300 to 2000 are more preferably used. Further, the kinematic viscosity of the ester in the present invention is 2 to 1 at 100 ° C.
It is desirably 50 cSt, preferably 5 to 100 cSt. The method for producing the ester in the present invention is optional. For example, (a) a diol containing no ether bond in the branch, (b) a dicarboxylic acid, and (c) a monohydric alcohol and / or a monohydric alcohol are esterified. By reacting, the mixture can be produced at once. It can also be produced by reacting (a) with the monohydric carboxylic acid of (c) or by reacting (b) with the monohydric alcohol of (c). As (a), those having 2 to 16 carbon atoms are used. Specifically, ethylene glycol, propylene glycol, butylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, heptamethylene glycol, Octamethylene glycol, nonamethylene glycol, decamethylene glycol, neopentyl glycol, 2-ethyl-2-methyl-1,3-propanediol, 2-methyl-2-propyl-1,3
-Propanediol, 2,2-dimethyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol,
Examples thereof include alkylene glycols such as 2-methyl-1,6-hexane, 1,4-cyclohexanedimethanol, and 2,2-bis (4-hydroxycyclohexyl) propane. As (b), a dicarboxylic acid having 2 to 10 carbon atoms is used. Specifically, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suvalic acid, azelaic acid, sebacic acid , Methylmalonic acid, ethylmalonic acid, dimethylmalonic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, 2,3-dimethylsuccinic acid, 2-ethyl-2-methylsuccinic acid, 2-methylglutaric acid, 3-methyl Glutaric acid, 3,3-dimethylglutaric acid, saturated aliphatic dicarboxylic acids such as 3-methyladipic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, unsaturated aliphatic dicarboxylic acids such as mesaconic acid, phthalic acid, Examples thereof include aromatic dicarboxylic acids such as isophthalic acid and terephthalic acid. Further, (c) monovalent carboxylic acids having 2 to 15 carbon atoms are used. Specifically, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decane Acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, 3-methylbutanoic acid, 2-methylbutanoic acid, 2-ethylhexanoic acid, 2,4-dimethylpentanoic acid, 3,3,5-trimethylhexanoic acid And benzoic acid. As the (c) monohydric alcohol, one having 1 to 15 carbon atoms is used. Specifically, methanol, ethanol, propanol, butanol, pentanol,
Hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, isopropanol, isobutanol, 2-methyl-1-butanol, 2,2
-Dimethyl-1-propanol, 3,3-dimethyl-1-butanol, 2-methyl-1-pentanol, 3-methyl-1-pentanol, 2,4,4-trimethyl-1-pentanol, 2, Examples thereof include 2,4-trimethyl-1-pentanol, 2-ethyl-4-methyl-1-pentanol, and 2-ethyl-1-hexanol. The product obtained from the raw material as described above may be purified to remove by-products and unreacted products, but a small amount of by-products and unreacted products are excellent performance of the refrigerating machine oil of the present invention. As long as it does not adversely affect, there is no problem if it is present. In order to further improve the stability of the refrigerating machine oil of the present invention, at least one epoxy selected from the group consisting of a phenylglycidyl ether type epoxy compound, a glycidyl ester type epoxy compound, an epoxidized fatty acid monoester and an epoxidized vegetable oil is used. A compound is compounded. Examples of the phenylglycidyl ether type epoxy compound referred to here include phenylglycidyl ether and alkylphenylglycidyl ether. The alkylphenyl glycidyl ether referred to herein is one having 1 to 3 alkyl groups having 1 to 13 carbon atoms, among which one having one alkyl group having 4 to 10 carbon atoms, for example, butyl phenyl glycidyl ether, bench Ruphenyl glycidyl ether,
Hexylphenyl glycidyl ether, heptylphenyl glycidyl ether,
Octylphenyl glycidyl ether, nonylphenyl glycidyl ether and decylphenyl glycidyl ether are preferred. Examples of the glycidyl ester type epoxy compound include phenyl glycidyl ester, alkyl glycidyl ester, and alkenyl glycidyl ester, and preferable examples include glycidyl benzoate, glycidyl acrylate, and glycidyl methacrylate. Further, as the epoxidized fatty acid monoester, epoxidized carbon number 12 to
Esters of 20 fatty acids and alcohols having 1 to 8 carbon atoms or phenols and alkylphenols can be exemplified. Especially butyl and hexyl of epoxy stearic acid,
Benzyl, cyclohexyl, methoxyethyl, octyl, phenyl and butylphenyl esters are preferably used. Examples of the epoxidized vegetable oil include epoxy compounds of vegetable oils such as soybean oil, linseed oil, and cottonseed oil. When these epoxy compounds are blended, 0.1 to 5.0 with respect to the total amount of the refrigerator oil.
% By weight, preferably 0.2 to 2.0% by weight. In the refrigerating machine oil composition of the present invention, in order to further improve its abrasion resistance and load resistance, phosphate ester, acidic phosphate ester, amine salt of acidic phosphate ester, chlorinated phosphate ester and phosphorous acid At least one phosphorus compound selected from the group consisting of esters can be blended. These phosphorus compounds are esters of phosphoric acid or phosphorous acid with alkanols or polyether alcohols or derivatives thereof. Specifically, examples of the phosphoric ester include tributyl phosphate, triphenyl phosphate, tricresyl phosphate, and the like. Examples of the acidic phosphate include ditetradecyl acid phosphate, dipentadecyl acid phosphate, dihexadecyl acid phosphate, diheptadecyl acid phosphate, dioctadecyl acid phosphate, and the like. Examples of the amine salt of the acidic phosphate include methylamine, ethylamine, propylamine, butylamine, pentylamine, and the like of the acidic phosphate.
Hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, triethylamine Examples thereof include salts with amines such as hexylamine, triheptylamine, and trioctylamine. Examples of the chlorinated phosphate include tris-dichloropropyl phosphate, tris-chloroethyl phosphate, polyoxyalkylene bis [di (chloroalkyl)] phosphate, and tris-chlorophenyl phosphate. Examples of the phosphite include dibutyl phosphite, tributyl phosphite, dipentyl phosphite, tripentyl phosphite, dihexyl phosphite, trihexyl phosphite, diheptyl phosphite, triheptyl phosphite, dioctyl phosphite, and trioctyl phosphite. Phyto, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, triundecyl phosphite, didodecyl phosphite, tridodecyl phosphite, diphenyl phosphite, triphenyl phosphite, dicresyl phosphite, tricresyl Phosphite and the like. Also, a mixture of these can be used.
When these phosphorus compounds are blended, 0.1 to 5.0% by weight based on the total amount of the refrigerator oil.
, Preferably at a rate of 0.2 to 2.0% by weight. In order to further improve the performance of the refrigerating machine oil of the present invention, conventionally known refrigerating machine oil additives, for example, di-tert-butyl-
phenol-based antioxidants such as p-cresol and bisphenol A; amine-based antioxidants such as phenyl-α-naphthylamine and N, N-di (2-naphthyl) -p-phenylenediamine; abrasion inhibitors such as zinc dithiophosphate; Additives such as chlorinated paraffins, extreme pressure agents such as sulfur compounds, oil agents such as fatty acids, antifoaming agents such as silicones, metal deactivators such as benzotriazole, etc. alone or in combination of several kinds It is also possible. The total amount of these additives is usually 1 to the total amount of refrigerating machine oil.
0% by weight or less, preferably 5% by weight or less. The refrigerating machine oil comprising the ester of the present invention as a main component generally has only to have a kinematic viscosity and a pour point of a degree that is used as the refrigerating machine oil. It is desirable that the temperature is −10 ° C. or lower, preferably −20 ° C. to −80 ° C. Further, in order to maintain the hermeticity with the compressor, the kinematic viscosity at 100 ° C. is desirably 2 cSt or more, preferably 3 cSt or more. Considering the fluidity at low temperature and the efficiency of heat exchange in the vaporizer, the kinematic viscosity at 100 ° C. Is 15
It is desirably 0 cSt or less, preferably 100 cSt or less. The refrigerating machine oil of the present invention has significantly better compatibility with non-chlorinated fluorocarbons than conventionally known refrigerating machine oils. Specific examples of the non-chlorinated chlorofluorocarbon include 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a) and 1,1-difluoroethane. (HFC-152a), trifluoromethane (HFC-23) and the like are exemplified, but preferred is HFC-152a.
134a. Further, the refrigerating machine oil of the present invention is excellent not only in compatibility with non-chlorinated chlorofluorocarbons, electrical insulation and safety, but also in high lubricity and low hygroscopicity. The lubricating oil for refrigerators of the present invention is particularly suitable for air conditioners having reciprocating or rotary compressors, dehumidifiers, refrigerators, freezers, freezing and refrigerated warehouses, vending machines, showcases, cooling devices for chemical plants and the like. Although it can be used preferably, it can also be used preferably with a centrifugal compressor. [Examples] Hereinafter, the contents of the present invention will be described more specifically with reference to examples and the like. Reference Examples 1 to 7 and Comparative Examples 1 to 6 Refrigeration oils used in Reference Examples and Comparative Examples are shown below. Reference Example 1: Diester of adipic acid and 2-ethyl-1-hexanol. Reference Example 2: Diester of 3-methyl-1,5-pentanediol and 3,5,5-trimethylhexanoic acid. Reference Example 3: 3-methyl-1,5-pentanediol, adipic acid and 3,5
Complex ester of 5-trimethylhexanoic acid with an average molecular weight of about 500. and Reference Example 4: The same composition as Reference Example 3 and an average molecular weight of about 700. Reference Example 5: Complex ester of 3-methyl-1,5-pentanediol, adipic acid and 2-ethyl-1-hexanol having an average molecular weight of about 520. and Reference Example 6: Same composition as Reference Example 5 and average molecular weight of about 750. Reference Example 7: A product obtained by adding 1.0 g of a phosphate ester type wear inhibitor to Reference Example 3. Comparative Example 1: Naphthenic mineral oil. Comparative Example 2: Branched alkylbenzene (average molecular weight: about 300). Comparative Example 3: Polyoxypropylene glycol monobutyl ether (average molecular weight: about 500). Comparative Example 4: Polyoxypropylene glycol monobutyl ether (average molecular weight: about 1000). Comparative Example 5: Polyoxypropylene glycol (average molecular weight 700). Comparative Example 6: Polyoxypropylene glycol (average molecular weight: about 2000). For the performance evaluation of the refrigerating machine oils of Reference Examples 1 to 7, the solubility with HFC-134a, the insulating properties, the Falex wear test and the hygroscopicity were evaluated. Also, for comparison,
Table 1 also shows the test results of mineral oil, alkylbenzene, polypropylene glycol monoalkyl ether and polyalkylene glycol disclosed in U.S. Pat. No. 4,755,316, which have been conventionally used for refrigerator oil. (Solubility with HFC-134a) In a glass tube having an inner diameter of 6 mm and a length of 220 mm, 0.2 g of a sample oil is taken, and 2 g of a refrigerant (HFC-134a) is taken and the glass tube is sealed. The glass tube is placed in a low-temperature bath or a high-temperature bath at a predetermined temperature, and it is observed whether the refrigerant and the sample oil are mutually dissolved, separated or clouded. (Insulation Characteristics) The volume resistivity of the sample oil was measured according to JIS C 2101. The test was performed at 25 ° C. (FALEX abrasion test) In accordance with ASTM D2670, after running in the sample oil at a temperature of 100 ° C. and a load of 150 lb for 1 minute, it was operated for 2 hours under a load of 250 lb to measure the wear amount of the test journal. Was. (Hygroscopicity) 30 g of the sample oil was placed in a 300 ml beaker, and allowed to stand in a thermo-hygrostat maintained at 60 ° C. and 30% humidity for 7 days, and then the water content was measured by the Karl Fischer method. As shown in Table 1, Reference Examples 1 to 7 had higher H than the refrigerating machine oils shown in Comparative Examples 1 and 2.
Very good refrigerant solubility for FC-134a. As shown in Comparative Examples 3 to 6, polyalkylene glycol is excellent in refrigerant dissolution but has poor insulation properties and cannot be used for a closed type compressor. Also, in the wear test by Falex, it can be seen that Reference Examples 1 to 7 are equal to or more than Comparative Examples 3 and 6. The refrigerating machine oils of Reference Examples 1 to 7 are also lower in moisture absorbency than the alkylene glycols of Comparative Examples 3 to 6 and have excellent moisture absorbency. Examples 1 to 4 and Comparative Examples 7 to 13 The following epoxy compounds were added to the refrigerating machine oils of Reference Examples 1 to 7 in amounts shown in Table 2, and the stability was evaluated by a shield tube test. The results are shown in Table 2. [Epoxy compounds 1 to 6] Epoxy compound 1: phenyl glycidyl ether epoxy compound 2: p-s-butylphenyl glycidyl ether epoxy compound 3: pt-butyl phenyl glycidyl ether epoxy compound 4: glycidyl 1,1-dimethyloctanoate Ester epoxy compound 5: Epoxidized soybean oil Epoxy compound 6: Epoxidized stearic acid ester (shield tube test) Place 50 g of sample oil in a 100 ml beaker, and leave it in a constant temperature and humidity chamber at a relative humidity of 80% and a temperature of 25 ° C for 168 hours. did. An equal mixture of this sample oil and HFC134a is
The change in the oil after sealing in a glass tube together with iron, copper and aluminum catalysts and heating at 175 ° C. for 168 hours was observed and evaluated. As shown in Examples 1 to 4 in Table 2, the refrigerating machine oil of the present invention is much more stable than the refrigerating machine oils shown in Comparative Examples 7 to 13. [Effects of the Invention] As is clear from the above description and Examples, the refrigerating machine oil of the present invention is suitable for use in a non-chlorinated CFC refrigerator, has excellent electrical insulation properties and abrasion resistance, Refrigeration oil excellent in non-hygroscopicity and stability.

Claims (1)

[Claims] 1. General formula Wherein R ₁ and R ₇ are divalent hydrocarbon groups having 1 to 8 carbon atoms, R ₂ and R ₄ are divalent saturated hydrocarbon groups having 2 to 16 carbon atoms, ₃ and R ₈ each represent an alkyl group having 1 to 15 carbon atoms; R ₅ and R ₆ each represent an alkyl group having 1 to 14 carbon atoms; 1 and m are 0 or 1; And a phenylglycidyl ether-type epoxy compound, a glycidyl ester-type epoxy compound, an epoxidized fatty acid monoester, and an epoxidized vegetable oil, based on the total amount of the refrigerating machine oil. A refrigerating machine oil for a non-chlorinated Freon refrigerant, comprising as an essential component 0.1 to 5.0% by weight of at least one epoxy compound selected from the group. However,
This excludes the case where an ester having all of the following (a) to (c) in the same molecule as a base oil is contained in the same molecule. (A) an aliphatic polyhydric alcohol having 1 to 6 primary hydroxy groups (b) a linear or branched saturated aliphatic monocarboxylic acid having 2 to 9 carbon atoms or a derivative thereof (c) having 2 to 10 carbon atoms 1. linear or branched saturated aliphatic dicarboxylic acids or derivatives thereof At least one phosphorus compound 0.1 to 5 selected from the group consisting of phosphate esters, acidic phosphate esters, amine salts of acidic phosphate esters, chlorinated phosphate esters and phosphite esters, based on the total amount of refrigerator oil. The refrigerating machine oil for non-chlorinated CFC refrigerants according to claim 1, which contains 0.0% by weight as an essential component. 3. General formula Wherein R ₁ and R ₇ are divalent hydrocarbon groups having 1 to 8 carbon atoms, R ₂ and R ₄ are divalent saturated hydrocarbon groups having 2 to 16 carbon atoms, ₃ and R ₈ each represent an alkyl group having 1 to 15 carbon atoms; R ₅ and R ₆ each represent an alkyl group having 1 to 14 carbon atoms; 1 and m are 0 or 1; The ester has a number average molecular weight of 300 to 2,000 represented by the following formula, and a volume resistivity at 25 ° C. of 1.1 × 10 ¹⁴ Ω · cm or more as a main component. As an essential component, 0.1 to 5.0% by weight of at least one epoxy compound selected from the group consisting of glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, epoxidized fatty acid monoesters and epoxidized vegetable oils. Refrigeration oil for non-chlorinated CFC refrigerants. However, this excludes the case where an ester having all of the following (a) to (c) in the same molecule as a base oil is contained in the same molecule. (A) an aliphatic polyhydric alcohol having 1 to 6 primary hydroxy groups (b) a linear or branched saturated aliphatic monocarboxylic acid having 2 to 9 carbon atoms or a derivative thereof (c) having 2 to 10 carbon atoms 3. linear or branched saturated aliphatic dicarboxylic acids or derivatives thereof; General formula Wherein R ₁ and R ₇ are divalent hydrocarbon groups having 1 to 8 carbon atoms, R ₂ and R ₄ are divalent saturated hydrocarbon groups having 2 to 16 carbon atoms, ₃ and R ₈ each represent an alkyl group having 1 to 15 carbon atoms; R ₅ and R ₆ each represent an alkyl group having 1 to 14 carbon atoms; 1 and m are 0 or 1; And a number average molecular weight of 200 to 3,000, and a volume resistivity at 25 ° C. of 1.
1 × 10 ¹⁴ Ω · cm or more and a kinematic viscosity at 100 ° C. of 2 to 150 cS
at least one epoxy compound selected from the group consisting of a phenylglycidyl ether type epoxy compound, a glycidyl ester type epoxy compound, an epoxidized fatty acid monoester, and an epoxidized vegetable oil, based on the total amount of the refrigerator oil. 1. A refrigerating machine oil for non-chlorinated CFC refrigerants, which contains 0.1 to 5.0% by weight as an essential component. However, in the same molecule, the following (a) to (c)
) Is excluded as a base oil containing an ester having all of the constituents. (A) an aliphatic polyhydric alcohol having 1 to 6 primary hydroxy groups (b) a linear or branched saturated aliphatic monocarboxylic acid having 2 to 9 carbon atoms or a derivative thereof (c) having 2 to 10 carbon atoms Linear or branched saturated aliphatic dicarboxylic acid or derivative thereof