JP2604638B2 - Refrigerating machine oil - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a refrigerating machine oil, and more particularly to a refrigerating machine oil excellent in various performances, mainly composed of a carbonate having a specific structure.

[Problems to be Solved by Conventional Techniques and Inventions] Conventionally, as refrigeration oil, kinematic viscosity at 40 ° C.
A naphthenic mineral oil, a paraffinic mineral oil, an alkylbenzene, a polyglycol-based oil, a mixture thereof, or a mixture of these various base oils with an additive of 10 to 200 cSt are generally used.

On the other hand, CFC-based refrigerants used in refrigerators include CF
C-11, CFC-12, CFC-115, HCFC-22 and the like are used.

Among these CFC-based refrigerants, CFC-11, CFC-12, CF
CFCs in which all the hydrogens of hydrocarbons such as C-115 are replaced by halogens containing chlorine are subject to regulation because they lead to ozone depletion. Therefore, HFC-134a and HFC-
Non-chlorinated chlorofluorocarbons such as 152a are being used as substitutes for CFCs.In particular, HFC-134a is the same as CFC-12, which has been used in many refrigerators such as home refrigerators, air conditioners, and car air conditioners. It has similar thermodynamic properties and is a promising alternative refrigerant.

Refrigerator oil has various required performances, but compatibility with the refrigerant is extremely important from the viewpoint of lubricity of the refrigerator and system efficiency. However, refrigeration oils based on naphthenic mineral oils, paraffinic mineral oils, alkylbenzenes, etc. have little compatibility with non-chlorinated chlorofluorocarbons such as HFC-134a. In the refrigeration system, the most important oil return property is deteriorated and the refrigerating efficiency is reduced or the lubricity is poor, causing various inconveniences such as seizure of the compressor. I can't stand it.

In order to solve this problem, we have developed HFC-134a
A polyglycol-based refrigerating machine oil, which has much better compatibility with conventional refrigerating machine oils, has been developed and has already been filed (JP-A-1-256594, JP-A-1-274191). etc). Also, U.S. Pat.No. 4,755,316 includes HFC-134a
Polyglycol-based refrigerating machine oils that are compatible with are disclosed. 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 the known refrigerating machine oils, those having the highest electrical insulation properties are alkylbenzenes and mineral oils. However, as described above, alkylbenzenes and mineral oils have almost no compatibility with non-chlorinated chlorofluorocarbons such as HFC-134a. Therefore, it is highly compatible with currently used chlorofluorocarbons such as CFC-12 and HCFC-22.
Refrigeration oils having both high compatibility with non-chlorinated chlorofluorocarbons and high insulation properties have not yet emerged.

The present inventors have conducted studies to develop a refrigerating machine oil that can meet the above-mentioned requirements, and as a result, carbonates having a specific structure are not limited to chlorofluorocarbons such as CFC-12, HCFC-22, and HCFC-142b. , HFC-134a, HFC-152a, etc. that have excellent compatibility with non-chlorinated chlorofluorocarbons and have high electrical insulation properties, and further have excellent lubricating properties, hydrolysis stability, and during hydrolysis. Of the present invention has been found to be less corrosive, and the present invention has been completed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a refrigerating machine oil having a carbonic ester having a specific structure as a main component, which has excellent compatibility with chlorofluorocarbon and high electrical insulation.

[Means for Solving the Problems] That is, the present invention provides a compound represented by the general formula [Wherein X ₁ is a hydrogen atom or a general formula Wherein R _{1 to} R ₃ may be the same or different and each have an alkyl group having 1 to 12 carbon atoms,
12 represents a cycloalkyl group or a neopentyl-type polyol residue having 5 to 30 carbon atoms and 3 to 8 hydroxyl groups, R ₄ represents an alkyl group having 1 to 6 carbon atoms, and a represents 1 or 2, b Represents 0 or 1 and represents a number satisfying a + b = 2, and m represents 0 to 30 (when m = 0, at least one of R ₁ and R ₂ represents a neopentyl-type polyol residue); and n represents an integer of 1 to 3]. A refrigerating machine oil characterized by having a carbonate represented by the following formula as a main component:

 Hereinafter, the contents of the present invention will be described in more detail.

The refrigerating machine oil of the present invention has a general formula Characterized by containing a carbonate represented by the following formula as a main component. In the above formula, X ₁ is a hydrogen atom or a general formula Wherein R _{1 to} R ₃ may be the same or different and each have 1 to 12 carbon atoms, preferably 3 to 7 alkyl groups, and 5 to 12 carbon atoms, preferably 5 to 8 carbon atoms. A cycloalkyl group or a neopentyl polyol residue having 5 to 30, preferably 5 to 21 and 3 to 8 hydroxyl groups,
R ₄ represents an alkyl group having 1 to 6 carbon atoms, preferably 1 to ₄ carbon atoms. A is 1 or 2, b is 0 or 1,
And a + b = 2, and m is 0 to 30 (m
= 0, at least one of R ₁ and R ₂ represents a neopentyl-type polyol residue), preferably 1 to
30 and n each represent an integer of 1 to 3. It is not preferable to use a carbonate ester that does not satisfy the above conditions as a main component because various properties such as compatibility with a non-chlorinated chlorofluorocarbon refrigerant are inferior.

As the alkyl group having 1 to 12 carbon atoms represented by R _{1 to} R ₃ , specifically, a methyl group, an ethyl group, an n-propyl group,
iso-propyl group, n-butyl group, iso-butyl group, sec
-Butyl group, tert-butyl group, n-pentyl group, iso-
Pentyl group, neo-pentyl group, n-hexyl group, iso-
Hexyl group, n-heptyl group, iso-heptyl group, n-
Octyl, iso-octyl, n-nonyl, iso-nonyl, n-decyl, iso-decyl, n-undecyl, iso-undecyl, n-dodecyl, iso-dodecyl, etc. The cycloalkyl group having 5 to 12 carbon atoms is a concept including an alkylcycloalkyl group. Specifically, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl Groups, cycloundecyl group, cyclododecyl group, methylcyclohexyl group, ethylcyclohexyl group, propylcyclohexyl group, butylcyclohexyl group, pentylcyclohexyl group and the like.
As the residue of the neopentyl polyol having 5 to 30 carbon atoms and 3 to 8 hydroxyl groups, specifically, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol,
Residues such as monomers are exemplified. Further, as the alkyl group having 1 to 6 carbon atoms represented by R ₄ , specifically, a methyl group,
Ethyl group, propyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group,
tert-butylyl, n-pentyl group, iso-pentyl group, n
Examples thereof include an eo-pentyl group, an n-hexyl group, and an iso-hexyl group.

The method for producing the carbonate ester used in the present invention is optional, for example, a chloroformate having 1 to 12 carbon atoms,
Reaction of pentaerythritol, trimethylolethane, trimethylolpropane, trimethylolbutane, or a dimer or trimer thereof, or a mixture thereof in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. It can be obtained by:

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 is not impaired, there is no problem even if it is present. In the present invention, the carbonate may be used in the form of a mixture or may be used alone. The molecular weight of the ester according to the present invention is not particularly limited, but from the viewpoint of further improving the sealing property of the compressor, those having a number average molecular weight of 200 to 3000 are preferably used, and the number average molecular weight is 300 to 2000. Are more preferably used. Further, the preferred kinematic viscosity of the carbonate ester according to the present invention is 2 to 150 cSt, preferably 4 to 100 cSt at 100 ° C.

The refrigerating machine oil of the present invention and the above-mentioned carbonate ester may be used alone, but if necessary, other refrigerating machine oil base oils may be mixed and used. Preferred examples of the base oil include the following.

In the general formula R ₅ OR _{7 C} OR ₆ [wherein, R ₅ and R ₆ represents hydrogen or an alkyl group having 1 to 18 carbon atoms, R ₇ represents an alkylene group having 2 to 4 carbon atoms,
c represents an integer of 5 to 70.] A polyoxyalkylene glycol or an ether thereof.

General formula [Wherein, R _{8 to} R ₁₀ represent hydrogen or an alkyl group having 1 to 18 carbon atoms, R _{11 to} R ₁₃ represent an alkylene group having 2 to 4 carbon atoms, and d to f represent an integer of 5 to 7 And a polyoxyalkylene glycol glycerol ether represented by the formula:

General formula Wherein X ₂ is -OR ₁₆ or X ₃ is a group represented by Or Wherein each of R ₁₄ and R ₂₀ is an alkylene group having 1 to 8 carbon atoms, and R ₁₅ and R ₁₇ are each a group having 2 to 16 carbon atoms.
R ₁₆ and R ₂₁ each represent an alkyl group having 1 to 15 carbon atoms; R ₁₈ and R ₁₉ each represent an alkyl group having 1 to 14 carbon atoms; g and h each represent an integer of 0 or 1;
Represents an integer of 0 to 30].

General formula [Wherein X ₄ is a methyl group, an ethyl group, a propyl group and a general formula Wherein R _{22 to} R ₂₅ are linear alkyl groups having 3 to 11 carbon atoms, branched alkyl groups having 3 to 15 carbon atoms, and 6 And 12 represents a group selected from cycloalkyl groups, wherein the proportion of linear alkyl groups is 60% or less based on all alkyl groups, and j represents an integer of 1 to 3].

General formula [Wherein X ₅ and X ₆ may be the same or different, and each represents a methyl group, an ethyl group, a propyl group and a general formula Represents any group selected from the group consisting of groups represented by the following formulas, wherein R _{26 to} R ₃₀ represent an alkyl group having 3 to 15 carbon atoms, and R ₃₁ represents a divalent hydrocarbon group having 1 to 8 carbon atoms. And k represents an integer of 1 to 5].

General formula Wherein R ₃₂ and R ₃₃ may be the same or different;
An alkyl group having 1 to 15 carbon atoms or 2 to 12 carbon atoms, respectively
Wherein R ₃₄ represents an alkylene group having 2 to 12 carbon atoms, and l represents an integer of 0 to 30].

These oils may be used alone or in combination of several kinds. Oils such as paraffinic and naphthenic mineral oils, poly-α-olefins, alkylbenzenes and the like may be mixed, but in this case, the compatibility with the non-chlorinated fluorocarbon solvent is reduced.

The amount of these base oils is not particularly limited as long as the excellent performance of the refrigerating machine oil of the present invention is not impaired, but is usually less than 50% by weight, preferably 30% by weight, based on the total amount of the refrigerating machine oil. % Or less.

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, dipentadidecyl acid phosphate, dihexadecyl acid phosphate, diheptadecyl acid phosphate, and dioctadecyl acid phosphate. Examples of the amine salt of the acidic phosphate include methylamine, ethylamine, propylamine, and butylamine of the acidic phosphate.
Pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentyl Examples thereof include salts with amines such as amine, trihexylamine, 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, it is desirable to incorporate them in a proportion of 0.1 to 5.0% by weight, preferably 0.2 to 2.0% by weight, based on the total amount of the refrigerating machine oil.

In the refrigerator oil of the present invention, in order to further improve the stability, at least one 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. The following epoxy compounds can be blended. 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, butylphenyl glycidyl ether, pentyl Phenyl glycidyl ether, hexyl phenyl glycidyl ether, heptyl phenyl glycidyl ether, octyl phenyl glycidyl ether,
Nonylphenyl glycidyl ether and decylphenyl glycidyl ether are preferred. As glycidyl ester type epoxy compounds, phenyl glycidyl ester,
Examples thereof include an alkyl glycidyl ester and an alkenyl glycidyl ester, and preferred examples include glycidyl benzoate, glycidyl allylate, and glycidyl methacrylate.

Examples of the epoxidized fatty acid monoester include esters of an epoxidized fatty acid having 12 to 20 carbon atoms and an alcohol or phenol or alkylphenol having 1 to 8 carbon atoms. Particularly, butyl, hexyl, benzyl, cyclohexyl, methoxyethyl, octyl, phenyl and butylphenyl esters of epoxystearic acid are preferably used.

Epoxidized vegetable oils include soybean oil, linseed oil,
Examples include epoxy compounds of vegetable oils such as cottonseed oil.

Preferred among these epoxy compounds are phenylglycidyl ether type epoxy compounds and epoxidized fatty acid monoesters. Above all, a phenylglycidyl ether type epoxy compound is more preferable, and phenylglycidyl ether, butylphenylglycidyl ether and a mixture thereof are particularly preferable.

When these epoxy compounds are blended, it is desirable that they be contained in a proportion of 0.1 to 5.0% by weight, preferably 0.2 to 2.0% by weight, based on the total amount of the refrigerator oil.

Furthermore, in the refrigerating machine oil of the present invention, its wear resistance,
In order to further improve the load carrying capacity of the general formula R ₃₅ -CH (COOH) ₂ and / or R ₃₆ -CH ₂ -COOH [wherein, R ₃₅ and R ₃₆ may be the same or different,
Each represents an alkyl group having 8 to 18 carbon atoms]. Specific examples of the carboxylic acid include octylmalonic acid, nonylmalonic acid, decylmalonic acid, undecylmalonic acid, dodecylmalonic acid, tridecylmalonic acid, tetradecylmalonic acid, pentadecylmalonic acid, hexadecylmalonic acid, Heptadecylmalonic acid, octadecylmalonic acid, decanoic acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, nonadecanoic acid, eicosanoic acid and mixtures of two or more of these Is mentioned.
When these carboxylic acids are blended, they are desirably contained in a proportion of 0.01 to 3% by weight, preferably 0.05 to 2% by weight, based on the total amount of the refrigerating machine oil.

Further, needless to say, two or more of the above phosphorus compounds, epoxy compounds and carboxylic acids may be used in combination.

Furthermore, in order to further improve the performance of the refrigerating machine oil of the present invention, conventionally known refrigerating machine oil additives such as di-tert-butyl-p-cresol, phenols such as bisphenol A, phenyl −α
Amine antioxidants such as -naphthylamine, N, N-di (2-naphthyl) -p-phenylenediamine; antiwear agents such as zinc dithiophosphate; extreme pressure agents such as chlorinated paraffins and sulfur compounds; fatty acids; It is also possible to compound additives such as an oily agent, an antifoaming agent such as silicone, a metal deactivator such as benzotriazole alone or in combination of several kinds. The total amount of these additives is usually 10% by weight or less, preferably 5% by weight or less, based on the total amount of the cooling machine oil.

In the present invention, when other refrigerating machine oils and additives are blended, the carbonate ester according to the present invention is preferably contained in an amount of more than 50% by weight, preferably 70% by weight or more based on the total amount of the refrigerating machine oil. .

Refrigeration oil containing the ester of the present invention as a main component is usually
It is only necessary to have a kinematic viscosity and a pour point of a degree used as a refrigerating machine oil, but in order to prevent solidification of the refrigerating machine oil at a low temperature, the pour point is −10 ° C. or less, preferably −20 ° C. to −
Preferably, it is 80 ° C. In order to maintain the sealing performance with the compressor, the kinematic viscosity at 100 ° C is preferably 2 cSt or more, and more preferably 3 cSt or more.In consideration of the fluidity at low temperature and the efficiency of heat exchange in the vaporizer, the kinematic viscosity at 100 ° C is considered. Is desirably 150 cSt or less, preferably 100 cSt or less.

As the refrigerant used in the refrigerating machine oil of the present invention, specifically, 1,1,2,2-tetrafluoroethane (HFC-134),
1,1,2-tetrafluoroethane (HFC-134a), 1,1-difluoroethane (HFC-152a), trifluoromethane (H
Non-chlorinated fluorocarbons such as FC-23), trichloromonofluoromethane (CFC-11), and dichlorodifluoromethane (CFC-
12), monochlorotrifluoromethane (CFC-13), monochloropentafluoromethane (CFC-115), monochlorodifluoromethane (HCFC-22), 1-chloro-1,1-
Chlorine-based chlorofluorocarbons such as difluoroethane (HCFC-142b), or a mixture of two or more of these chlorinated fluorocarbons may be used.
HFC-134a is preferred. The refrigerating machine oil of the present invention has significantly better compatibility with non-chlorinated fluorocarbons than conventionally known refrigerating machine oils.

Further, the refrigerating machine oil of the present invention is an excellent refrigerating machine oil having not only high compatibility with non-chlorinated chlorofluorocarbons and high electric insulation but also high lubricity and low hygroscopicity.

The refrigerating machine oil of the present invention is particularly preferably used for an air conditioner having a reciprocating or rotary compressor, a dehumidifier, a refrigerator, a freezer, a freezing and refrigerated warehouse, a vending machine, a showcase, a cooling device of a chemical plant and the like. However, those having a centrifugal compressor can also be preferably used.

[Examples] Hereinafter, the contents of the present invention will be described more specifically with reference to Examples and Comparative Examples.

Examples 1 to 3 and Comparative Examples 1 to 5 Refrigeration oils used in the present examples and comparative examples are shown below.

Example 1: A carbonate having a branched structure represented by the formula 1, wherein R is is
o-C ₆ H _13, or, iso-C ₇ H ₁₅ Example 2: In a carbonate having a branched structure represented by the formula 2, R is
o-C ₆ H _13, or, iso-C ₇ H ₁₅ Example 3: In a carbonate having a branched structure represented by the formula 3, R is
o-C ₃ H ₇ or, iso-C ₄ H ₉ Comparative Example 1: Naphthenic mineral oil.

Comparative Example 2: Branched alkylbenzene (average molecular weight of about 30
0).

Comparative Example 3: Pentaerythritol and tetraester of 2-methyl-hexanoic acid and 2,4-dimethylheptanoic acid.

Comparative Example 4: Complex ester of 3-methyl-1,5-pentanediol, adipic acid and 3,5,5-trimethylhexanoic acid having an average molecular weight of about 500.

Comparative Example 5: Polyoxypropylene glycol (average molecular weight: about 900).

For the performance evaluation of the base oils of the refrigerating machine oils of Examples 1 to 3 according to the present invention, the solubility with HFC-134a, the hydrolyzability, the insulating properties, the Falex abrasion test and the absorption were evaluated. For comparison, mineral oil, alkylbenzene, ester oil and U.S. Pat.
Table 1 also shows the test results of the polyalkylene glycol disclosed in No. 755,316 (Comparative Examples 1 to 5).

(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 the sample oil of each of Examples and Comparative Examples was sampled, and a refrigerant (HFC-134a) 2.0
Collect g and seal the glass tube. 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.

(Hydrolysis test) 60 g of sample oil and 0.6 g of water were placed in a 200 ml glass test tube, and a copper plate, an iron plate and an aluminum plate (each 6 cm ² ) were added as a catalyst for promoting deterioration, and the mixture was placed in a stainless steel autoclave for 175 minutes. Degraded by heating at ℃ for 168 hours.

 After the test, the acid value and hydroxyl value of the sample oil were measured.

(Insulation Characteristics) The volume resistivity of the sample oil at 25 ° C. was measured in accordance with JIS C2101.

(FALEX abrasion test) Sample oil temperature 100 ℃, 150lb according to ASTM D2670
After running-in for 1 minute under load, the test journal was operated under a load of 250 lbs for 2 hours, and the wear amount of the test journal was measured.

(Hygroscopicity) 30 g of the sample oil was placed in a 300 ml beaker, and allowed to stand in a thermo-hygrostat kept at 30 ° C. and 60% humidity for 7 days, and then the water content was measured by the Karl Fischer method.

As shown in Examples 1 to 3 in Table 1, the refrigerating machine oil according to the present invention has extremely excellent refrigerant solubility in HFC-134a as compared with Comparative Examples 1 and 2.

As shown in Comparative Examples 3 and 4, ester oil is soluble in refrigerant,
Although it has excellent electrical insulation properties, it has poor hydrolyzability, and there is a problem in use in a refrigerator system in which water is expected to be mixed or penetrated due to corrosion of generated acid. On the other hand, Examples 1 to 3
Although it is slightly hydrolyzed to generate a hydroxyl group, no acid is generated, so there is no problem.

Examples 1 to 3 are also comparable to mineral oils and alkylbenzenes in terms of insulating properties, are almost equivalent to ester oils, and are superior to the alkylene glycol oils of Comparative Example 5.

Also in the wear test by Falex, it can be seen that Examples 1 to 3 are equal to or more than Comparative Examples 1 to 5.

Regarding the hygroscopicity of water, the refrigerating machine oils of Examples 1 to 3 are not inferior to Comparative Examples 1 and 2 and are almost equal to the ester oils of Comparative Examples 3 and 4, and furthermore, the alkylene glycol of Comparative Example 5 Are also extremely low in hygroscopicity.

[Effect 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 refrigerating machine, has excellent electrical insulation properties, and has excellent wear resistance and non-hygroscopicity. Refrigeration oil.

Continued on the front page (51) Int.Cl. ⁶ Identification number Reference number in the agency FI Technical display location C10M 107: 32 105: 38 137: 04 137: 08 137: 02 129: 18 129: 66) (C10M 169/04) 105: 48 129: 40 129: 42) C10N 40:16 40:30

Claims (8)

(57) [Claims] (1) General formula [Wherein X ₁ is a hydrogen atom or a general formula Wherein R _{1 to} R ₃ may be the same or different and each have an alkyl group having 1 to 12 carbon atoms,
12 represents a cycloalkyl group or a neopentyl-type polyol residue having 5 to 30 carbon atoms and 3 to 8 hydroxyl groups, R ₄ represents an alkyl group having 1 to 6 carbon atoms, and a represents 1 or 2, b Represents 0 or 1 and represents a number satisfying a + b = 2, and m represents 0 to 30 (when m = 0, at least one of R ₁ and R ₂ represents a neopentyl-type polyol residue); and n represents an integer of 1 to 3.] A refrigerating machine oil comprising a carbonate represented by the following formula: 2. The refrigerating machine oil according to claim 1, wherein the refrigerant used is a non-chlorinated fluorocarbon. 3. The refrigerating machine oil according to claim 1, wherein the carbonate ester is used as a base oil. Wherein (I) said carbonic acid ester, and (II) In the general formula R ₅ OR _{7 C} OR ₆ [wherein, R ₅ and R ₆ represents hydrogen or an alkyl group having 1 to 18 carbon atoms, R ₇ Represents an alkylene group having 2 to 4 carbon atoms,
c represents an integer of 5 to 70], a polyoxyalkylene glycol represented by the formula: [Wherein, R _{8 to} R ₁₀ represent hydrogen or an alkyl group having 1 to 18 carbon atoms, R _{11 to} R ₁₃ represent an alkylene group having 2 to 4 carbon atoms, and d to f represent an integer of 5 to 7 Polyoxyalkylene glycol glycerol ether represented by the general formula: Wherein X ₂ is -OR ₁₆ or X ₃ is a group represented by Or Wherein each of R ₁₄ and R ₂₀ is an alkylene group having 1 to 8 carbon atoms, and R ₁₅ and R ₁₇ are each a group having 2 to 16 carbon atoms.
R ₁₆ and R ₂₁ each represent an alkyl group having 1 to 15 carbon atoms; R ₁₈ and R ₁₉ each represent an alkyl group having 1 to 14 carbon atoms; g and h each represent an integer of 0 or 1;
Is an integer of 0 to 30], an ester represented by the general formula: [Wherein X ₄ is a methyl group, an ethyl group, a propyl group and a general formula Wherein R _{22 to} R ₂₅ are linear alkyl groups having 3 to 11 carbon atoms, branched alkyl groups having 3 to 15 carbon atoms, and 6 A group selected from cycloalkyl groups of from 12 to 12, wherein the proportion of linear alkyl groups is 60% or less based on all alkyl groups, and j is an integer of from 1 to 3]. [Wherein X ₅ and X ₆ may be the same or different, and each represents a methyl group, an ethyl group, a propyl group and a general formula Represents any group selected from the group consisting of groups represented by the following formulas, wherein R _{26 to} R ₃₀ represent an alkyl group having 3 to 15 carbon atoms, and R ₃₁ represents a divalent hydrocarbon group having 1 to 8 carbon atoms. And k represents an integer of 1 to 5], and a polyol dicarboxylic acid ester represented by the following general formula: Wherein R ₃₂ and R ₃₃ may be the same or different;
An alkyl group having 1 to 15 carbon atoms or 2 to 12 carbon atoms, respectively
Wherein R ₃₄ represents an alkylene group having 2 to 12 carbon atoms, l represents an integer of 0 to 30], and at least one kind selected from the group consisting of: The refrigerating machine oil according to claim 1 or 2, wherein a base oil is a mixed oil of the oil. 5. The refrigerating machine oil according to claim 3, wherein the (I) carbonate ester is blended in an amount exceeding 50% by weight based on the total amount of the refrigerating machine oil. 6. At least one phosphorus compound 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 according to any one of claims 1 to 5, comprising 0.1 to 5.0% by weight as an essential component. 7. 0.1 to 5.0% by weight of 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. The refrigerating machine oil according to any one of claims 1 to 6, further comprising: 8. A method according to claim 1, wherein the total amount of the refrigerating machine oil is represented by a general formula: R ₃₅ —CH (COOH) ₂ and / or R ₃₆ —CH ₂ —COOH, wherein R ₃₅ and R ₃₆ may be the same or different;
The refrigerating machine oil according to any one of claims 1 to 7, which contains 0.01 to 3% by weight of a carboxylic acid represented by the following formula: