JP2514090C - - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a lubricating oil composition for a refrigeration apparatus using 1,1,1,2-tetrafluoroethane as a refrigerant. [Prior art] Conventionally, various types of refrigerators have been used. Among them, a so-called vapor compression type refrigerator using a refrigerant has a reciprocating type, a centrifugal type and a rotary type due to the structure of the compressor. Classified. Among them, a refrigerator with a rotary (rotary) compressor has such features that it has a large refrigerating capacity even in a small size, can exhibit excellent performance even in a high rotation range, and can operate smoothly and quietly. It is widely used for home refrigerators and air conditioners. Naphthenic mineral oils having a kinematic viscosity of 5 to 200 cSt at 40 ° C.
A paraffinic mineral oil, an alkylbenzene, a polyglycol-based oil, a mixture thereof, or a mixture of these various base oils with an additive is generally used. On the other hand, as a refrigerant of the compression refrigerator, halogen represented by trichloromonofluoromethane (CFC 11), dichlorodifluoromethane (CFC 12), monochlorodifluoromethane (CFC 22), or trichlorotrifluoroethane (CFC 113) is used. A wide range of refrigerants, hydrocarbon refrigerants such as propane, and inorganic gas refrigerants such as ammonia and carbon dioxide are widely used. Among them, halogen-based refrigerants have been widely used in refrigerators such as home refrigerators and air conditioners because they are chemically stable, have low toxicity, are nonflammable, and have ideal thermodynamic characteristics. However, of these, perhalogenocarbons, i.e., chlorofluorocarbons in which all the hydrogens of hydrocarbons have been replaced with halogens, are hardly decomposable and have high stability. , 25-3 above ground
It reaches the 0 km ozone layer and encounters strong ultraviolet rays from the sun, decomposes and releases chlorine atoms, reacts with ozone, and reduces the ozone concentration in the ozone layer. This ozone layer
It absorbs harmful ultraviolet rays from the sun and protects creatures on the surface of the earth. In order to prevent the depletion of the ozone layer by CFCs, the production and consumption of CFCs are being regulated by international treaties. Under these circumstances, the United States Environmental Protection Agency (EPA)
Dichloro-2,2,2-trifluoroethane (CFC-123), 1-chloro-
1,2,2,2-tetrafluoroethane (CFC-124), 1,2-dichloro-2,2-difluoroethane (CFC-132b), 1-chloro-2,2,2-
Trifluoroethane (CFC-133a), 1,1,1,2-tetrafluoroethane (FC-134a) and 1,1-dichloro-1-fluoroethane (CFC
-141b) are proposed as alternative refrigerants. Among these compounds, 1,1,1,2-tetrafluoroethane has similar thermodynamic properties to dichlorodifluoromethane (CFC 12), which has been conventionally used in refrigerators such as home refrigerators and air conditioners. And the refrigerant is 1,1
The use of 1,1,2-tetrafluoroethane (FC-134a) should be able to obtain the same performance as the conventional one without largely changing the design of those refrigerator systems. However, for that purpose, the refrigerating machine oil filled in the compressor enters the condenser and the evaporator together with the discharge gas, so that it is sufficiently dissolved in the refluxing refrigerant, circulates in the cycle and returns to the compressor. Good oil return is essential. That is, since it is not uncommon for the temperature to reach −20 to −30 ° C. from the expansion valve or the capillary tube, which is the coldest part in the refrigerating cycle, to the evaporator, the refrigerating machine oil is used at such a low temperature. Those which do not cause two-layer separation with the refrigerant are preferred. Since it is not unusual for a compressor, a receiver, and a condenser to reach a high temperature, it is preferable that the refrigerating machine oil not cause two-layer separation from the refrigerant in the high-humidity region in addition to the low-temperature region. Conventionally, as a refrigerating machine oil, a naphthenic mineral oil, a paraffinic mineral oil, an alkylbenzene, a mixture thereof, or a mixture of these various base oils with additives has been generally used. For these conventional refrigerating machine oils, for example,
11940, JP-B-49-4107, JP-B-49-13483, JP-B-4
Nos. 9-13829, JP-B-49-19084, JP-B-52-39509, JP-B-52-43722, JP-B-53-17602, JP-A-46-4532, JP-A-48-606, JP-A-49-47498, JP-A-51-22971
JP-A-52-28503, JP-A-52-54707, JP-A-53-88
007 or the like. However, these conventional refrigerating machine oils have almost no compatibility with 1,1,1,2-tetrafluoroethane (FC-134a) which is a substitute refrigerant for dichlorodifluoromethane (Freon 12), so that 1,1,1 ,
When used in combination with 2-tetrafluoroethane, two-layer separation occurs at normal temperature, and the most important oil return property in the refrigeration system is deteriorated, and the refrigeration efficiency is reduced or lubricity is poor, and the compressor is burned. Practical inconveniences such as the occurrence of jaggedness occur and the product cannot be used. Polyglycols are also known as refrigerating machine oils having a high viscosity index, and are described, for example, in JP-B-57-42119, JP-B-61-52880, and JP-A-57-51795. However, the polyglycol oils specifically disclosed in these prior arts still have insufficient compatibility with 1,1,1,2-tetrafluoroethane, and therefore have the same problems as described above, and cannot be used practically. [Problems to be Solved by the Invention] As a result of repeated studies to develop a lubricating oil composition for a compression refrigeration apparatus using 1,1,1,2-tetrafluoroethane as a refrigerant, When a polyglycol oil having a limited structure and properties is used as a base oil, it has been found that a refrigerating machine oil composition having excellent performance that cannot be obtained with other base oils can be obtained,
The present invention has been completed. The present invention is suitable for use in a compression refrigeration apparatus using 1,1,1,2-tetrafluoroethane as a refrigerant. It is an object of the present invention to provide a good lubricating oil composition for a refrigerator. [Means for Solving the Problems] The present invention uses a general formula (Wherein, R ₁ represents an alkyl group having 1 to 18 carbon atoms, a represents an integer of 5 to 70, R ₂ represents an alkylene group having 2 to 4 carbon atoms, and (R The ratio of the number of —OR ₂ — groups in which ₂ is an ethylene group) / a (hereinafter referred to as α) is more than 0 and not more than 0.8), and the pour point is -10 ° C. or less, The kinematic viscosity at 100 ° C. is 2 to (1
0 + 120α) cSt, the number average molecular weight is more than 506 and less than 2000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.00 to 1.2.
A lubricating oil composition for refrigeration equipment using 1,1,1,2-tetrafluoroethane as a refrigerant, characterized by using polyoxyalkylene glycol monoether which is 0 as a base oil. . Further, the present invention provides a compound represented by the general formula (Wherein, R ₁ represents an alkyl group having 1 to 18 carbon atoms, a represents an integer of 5 to 70, R ₂ represents an alkylene group having 2 to 4 carbon atoms, and (R The ratio of the number of —OR ₂ — groups in which ₂ is an ethylene group) / a (hereinafter referred to as α) is more than 0 and not more than 0.8), and the pour point is -10 ° C. or less, The kinematic viscosity at 100 ° C. is 2 to (1
0 + 120α) polyoxyalkylene glycol having cSt, a number average molecular weight of less than 2000, and a ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 1.00 to 1.20 Monoether is used as a base oil, and based on 100 parts by weight of the base oil, (A) a general formula (Wherein, R ₃ represents an alkyl group having 1 to ₃ carbon atoms, and b represents an integer of 0 to 2) 0.1 to 5.0 parts by weight of a phosphate represented by the following formula: An object of the present invention is to provide a lubricating oil composition for refrigeration equipment using 1,1,1,2-tetrafluoroethane as a refrigerant. Further, the present invention provides a compound represented by the general formula (Wherein, R ₁ represents an alkyl group having 1 to 18 carbon atoms, a represents an integer of 5 to 70, R ₂ represents an alkylene group having 2 to 4 carbon atoms, and (R The ratio of the number of —OR ₂ — groups in which ₂ is an ethylene group) / a (hereinafter referred to as α) is more than 0 and not more than 0.8), and the pour point is -10 ° C. or less, The kinematic viscosity at 100 ° C. is 2 to (1
0 + 120α) cSt and the ratio of weight average molecular weight (Mw) to number average molecular weight (Mn)
A polyoxyalkylene glycol monoether having a (Mw / Mn) of 1.00 to 1.20 is used as a base oil. (Wherein, R ₃ represents an alkyl group having 1 to ₃ carbon atoms, and b represents an integer of 0 to 2). 0.1 to 5.0 parts by weight of a phosphate represented by the following formula: (B) (i) phenyl 0.1 to 5.0 parts by weight of at least one epoxy compound selected from the group consisting of a glycidyl ether type epoxy compound, (ii) an epoxidized fatty acid monoester, and (iii) an epoxidized vegetable oil is blended as an essential component. It is intended to provide a lubricating oil composition for refrigeration equipment using 1,1,1,2-tetrafluoroethane as a refrigerant. Further, the present invention provides a compound represented by the general formula (Wherein, R ₁ represents an alkyl group having 1 to 18 carbon atoms, a represents an integer of 5 to 70, R ₂ represents an alkylene group having 2 to 4 carbon atoms, and (R The ratio of the number of —OR ₂ — groups in which ₂ is an ethylene group) / a (hereinafter referred to as α) is more than 0 and not more than 0.8), and the pour point is -10 ° C. or less, The kinematic viscosity at 100 ° C. is 2 to (1
0 + 120α) cSt, the number average molecular weight is more than 506 and 1500 or less, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.00 to 1.2.
A lubricating oil composition for refrigeration equipment using 1,1,1,2-tetrafluoroethane as a refrigerant, characterized by using polyoxyalkylene glycol monoether as a base oil as a base oil. It is. Hereinafter, the contents of the present invention will be described in more detail. The base oil of the refrigerating machine oil composition of the present invention has the following general formula (I): Is a polyoxyalkylene glycol monoether. In the formula, R ₁ represents a linear or branched alkyl group having 1 to 18 carbon atoms, and a represents an integer of 5 to 70, respectively. R ₂ represents an alkylene group having 2 to 4 carbon atoms. Specific examples of R ₁ include, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl Groups, a pentadecyl group, a hexadecyl group, a heptadecyl group, an octadecyl group, and the like. Among them, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, and an octadecyl group are more preferable. As R ₂ , specifically, for example, an ethylene group (—CH ₂ CH ₂ —), Trimethylene group _{(-CH 2 CH 2 CH 2 -} ), Examples include a tetramethylene group (—CH ₂ CH ₂ CH ₂ CH ₂ —), and among them, an ethylene group, a propylene group, a butylene group, and a tetramethylene group are more preferable. Further, in the polyoxyalkylene glycol monoether of the present invention, an alkylene group having a different number of carbon atoms may be present in one molecule, that is, an oxyalkylene group having a different number of carbon atoms is randomly or block copolymerized. However, the ratio (α) of (the number of —OR ₂ — groups in which R ₂ is an ethylene group) / a in one molecule needs to be more than 0 and 0.8 or less. If the value of α exceeds 0.8, the refrigerating machine oil becomes solid at room temperature or its pour point becomes undesirably high. The polyoxyalkylene glycol monoether in the present invention has a pour point of -10 ° C or lower, preferably -20 to -50 ° C, and a kinematic viscosity at 100 ° C of 2 to (10 + 120α) cSt, preferably 3 to ( 7 + 120α) cSt
Must be within the range. If the pour point exceeds −10 ° C., the refrigerating machine oil may be solidified in the refrigerating system at a low temperature, which is not preferable. When the kinematic viscosity at 100 ° C. is less than 2 cSt, the compressor cannot maintain the hermeticity. On the other hand, when the kinematic viscosity exceeds (10 + 120α) cSt, the refrigerant 1,1,
The solubility with 1,2-tetrafluoroethane is poor, and the two layers are separated at a low temperature, which is not preferable. As the polyoxyalkylene glycol monoether in the present invention, those having a number average molecular weight of 300 to 4000 are preferably used from the viewpoint of further improving the sealing property of the compressor, and those having a number average molecular weight of 500 to 3500 are preferred. More preferably used. Furthermore, those having a number average molecular weight of 500 to 1500 are more preferably used from the viewpoint of raising the two-layer separation temperature with the refrigerant under high temperature. Further, the polyoxyalkylene glycol monoether in the present invention has a ratio (Mw / Mn) of 1 between the weight average molecular weight (Mw) and the number average molecular weight (Mn).
. When it is 00 to 1.20, the two-layer separation temperature with the refrigerant at a high temperature is further increased. The lubricating oil composition for a refrigeration apparatus of the present invention can be prepared by using the above-mentioned polyoxyalkylene glycol monoether as a base oil alone, that is, without adding any additive, 1,1, It exhibits excellent performance as a lubricating oil for refrigeration equipment using 1,1,2-tetrafluoroethane as a refrigerant, but in order to further enhance its wear resistance and load resistance (anti-seizure properties), formula It is preferable to blend a phosphate represented by the following formula. In the formula, R ₃ has 1 to ₃ carbon atoms.
Represents an alkyl group, preferably a methyl group, and b represents 0 to 2, preferably 0 to 1
Are respectively shown. Specific examples of R ₃ include a methyl group, an ethyl group, and a propyl group. As the phosphate as the component (A), specifically, triphenyl phosphate, tolyl phosphate (tricresyl phosphate), and a mixture thereof are preferably used. When the component (A) is used in the lubricating oil composition for a refrigeration apparatus of the present invention in order to further improve the wear resistance and the load resistance, the amount of the component (A) is 0.1 to 100 parts by weight of the base oil. To 5.0 parts by weight, preferably 0.2 to 2.0 parts by weight. (
When the compounding amount of the component (A) does not reach this range, the wear resistance due to the compounding of the component (A),
If the effect of improving the load resistance is poor, and if the amount of the component (A) exceeds this range, the heat stability may be reduced or metals in the refrigeration system may be corroded, which is not preferable. . In the lubricating oil composition for a refrigerator according to the present invention, as described above, by blending the component (A) as an essential component in a specific amount, the wear resistance and the load resistance are improved. In the case where copper or a copper alloy is used for such purposes, there is a danger that the metal may occasionally be corroded due to the blending of the component (A). Therefore, when the component (A) is blended, (B) (i) a phenylglycidyl ether type epoxy compound, and (ii) an epoxidized fatty acid It is preferable to blend at least one epoxy compound selected from the group consisting of an ester and (iii) an epoxidized vegetable oil. Examples of the (i) phenyl glycidyl ether type epoxy compound include phenyl glycidyl ether and alkyl phenyl glycidyl ether. The alkyl phenyl glycidyl ether referred to herein is one having 1 to 3 alkyl groups having 1 to 13 carbon atoms, and among them, an alkyl group having 4 to 10 carbon atoms is one.
Preferred are butyl phenyl glycidyl ether, pentyl phenyl glycidyl ether, hexyl phenyl glycidyl ether, heptyl phenyl glycidyl ether, octyl phenyl glycidyl ether, nonyl phenyl glycidyl ether, and decyl phenyl glycidyl ether. Also, (ii) the epoxidized fatty acid monoester includes an epoxidized C 1
Esters of 2 to 20 fatty acids with 1 to 8 carbon atoms of alcohols or phenols and alkylphenols can be exemplified. Particularly, butyl, hexyl, benzyl, cyclohexyl, methoxyethyl, octyl, phenyl and butylphenyl esters of epoxystearic acid are preferably used. Examples of the (iii) epoxidized vegetable oil include epoxy compounds of vegetable oils such as soybean oil, linseed oil, and cottonseed oil. Among these epoxy compounds (i) to (iii), those preferable as the component (B) are a phenylglycidyl ether type epoxy compound and an epoxidized fatty acid monoester. Above all, a phenylglycidyl ether type epoxy compound is more preferable, and phenylglycidyl ether, butylphenylglycidyl ether and a mixture thereof are particularly preferable. In the lubricating oil composition for a refrigerator according to the present invention, the composition further comprises (A)
When the component (B) is used in combination as an essential component, the amount of the component (B) is 100
It is 0.1 to 5.0 parts by weight, preferably 0.2 to 2.0 parts by weight based on parts by weight. When the amount of the component (B) does not reach this range, the effect of improving the corrosion prevention by the component (B) is poor. On the other hand, when the amount of the component (B) exceeds this range, the abrasion resistance and the anti-corrosion property are reduced. Each of them is not preferable because it has an adverse effect on loadability. In order to further enhance the performance of the lubricating oil composition for a refrigeration apparatus of the present invention, conventionally known refrigeration oil additives such as di-tert-butyl-
Phenols such as P-cresol, phenyl-α-naphthylamine, N, N ′
Amine-based antioxidants such as -di (2-naphthyl) -p-phenylenediamine;
Load-bearing additives such as zinc dithiophosphate, chlorinated paraffin, fatty acids, sulfur, etc., silicone-based defoamers, metal deactivators such as benzotriazole, glycidyl methacrylate, phosphite-based hydrogen chloride scavengers And the like can be used alone or in combination of several kinds. The lubricating oil composition for a refrigerator according to the present invention, which uses 1,1,1,2-tetrafluoroethane as a refrigerant, is particularly preferably used for a refrigerator having a rotary (rotary) compressor. However, it can be preferably used for other refrigerating and refrigerating apparatuses having a reciprocating or centrifugal compressor. The lubricating oil composition for a refrigerator according to the present invention can be used for refrigerators, freezers, refrigerator-freezer warehouses, vending machines, showcases, cooling devices such as chemical plants, dehumidifiers, and the like. Examples of the Invention Hereinafter, the contents of the present invention will be described more specifically with reference to Examples and Comparative Examples. Examples 1 to 5 and Comparative Examples 1 to 17 The properties of the base oil of the refrigerating machine oil used in Examples and Comparative Examples are shown in Table 1. In order to measure the low-temperature separability between the refrigerating machine oil (Examples 1 to 5) and the refrigerant according to the present invention, the base oils of Examples 1 to 5 were added to 1,1,1,2-tetrafluoroethane as a refrigerant. A mixed liquid containing 10, 20, 30, 40, 50 and 70 parts by weight was prepared, and the mixed liquid was gradually cooled from room temperature, and the temperature at which the mixed liquid became cloudy or separated into two layers, that is, the low temperature side Was determined. In the case where cloudiness or two-layer separation had already occurred at room temperature, the temperature was gradually increased to obtain a temperature at which the cloudiness or two-layer separation was eliminated, and this was taken as the low-temperature side two-layer separation temperature. The results are shown in Table 2. Further, in order to measure the high-temperature separability between the refrigerant oil (Examples 1 to 5) according to the present invention and the refrigerant, 3, 10 and 30 parts by weight of the base oils of Examples 1 to 5 were added to the same refrigerant as above. A mixed solution was prepared, and the obtained mixed solution was gradually heated from room temperature, and the temperature at which the mixed solution became cloudy or separated into two layers, that is, the two-layer separation temperature on the high temperature side was also determined. In the case where cloudiness or two-layer separation had already occurred at room temperature, the temperature was gradually reduced to obtain a temperature at which no cloudiness or two-layer separation occurred, and this was taken as the high-temperature side two-layer separation temperature. The results are shown in Table 2. For comparison, the base oils of Comparative Examples 1 to 17, which are out of the scope of the present invention, were also used to determine the low-temperature two-layer separation temperature in the same manner as in Examples 1 to 5. The results are also shown in Table 2. Examples 6 to 13 and Comparative Examples 18 to 19 Refrigeration oil compositions according to the present invention were obtained from the compositions shown in Table 3. Example 6
9 to the specific invention (Claim 1), Embodiment 10 is the invention of Claim 2, and Embodiments 11 to 13.
The present invention relates to the third aspect of the present invention. The performance of these compositions was evaluated by the test methods described below, and the results are also shown in Table 3. (Falex baking load test) According to ASTM D3233, the baking load was measured under the conditions of an initial oil temperature of 25 ° C, a running-in operation of 250 lb, and 5 minutes. (Shield tube test) Oil and catalyst after an equal volume mixture of oil and refrigerant (1,1,1,2-tetrafluoroethane) was sealed in a glass tube with copper and iron catalysts and heated at 175 ° C. for 1000 hours. Was observed and measured. The degree of discoloration of the oil was classified into 12 levels, with blackish brown being 11 and colorless being 0. There is no problem with discoloration of the metal catalyst as long as the gloss is lost, but it is defective when the iron catalyst is plated with copper. As is clear from the results of the two-layer separation temperature in Table 2, Examples 1 to 5 according to the present invention were used.
Is 1,1,1,2-tetrafluoroethane and -20 to-
It shows very good compatibility even at a low temperature of about 30 ° C. On the other hand, the mineral oils and alkylbenzenes of Comparative Examples 13 to 15 and the diethers as in Comparative Example 16 even if they are polyglycol oils, and even if they are monoethers as in Comparative Example 17, even those other than the viscosity range of the present invention. In this case, even at room temperature, two-layer separation occurs with the refrigerant at a low temperature, especially in Comparative Examples 13 to 16, so that it cannot be put to practical use. Further, Mn is 500 to 1500 and Mw / Mn is 1.00 to 1.2.
The refrigerating machine oils of Examples 1 to 5 using polyoxyalkylene glycol monoether, which is 0, as a base oil, show very good compatibility with the above refrigerant not only at a low temperature but also at a high temperature of about 60 to 80 ° C. I have. Further, as is clear from the results of the performance evaluation test in Table 3, the refrigerating machine oils of Examples 6 to 9 according to the specific invention of the present invention show excellent performance in the Falex test and the shield tube test. The composition of Example 10 according to the present invention has a significantly improved seizure load in a Falex test due to the combination of the component (A), and is a refrigerating machine oil having more excellent lubricity. Furthermore, the compositions of Examples 11 to 13 according to the invention of Claim 3 of the present invention were obtained by comparing Comparative Examples 19 and 10 while maintaining excellent lubricity.
The results of the shield tube test are improved as compared with the composition of Example 1. In particular, Examples 11 to
In the composition of No. 13, the result of the shield tube test was improved as compared with the refrigerating machine oils of Examples 6 to 9 consisting only of the base oil, and the effect of blending the component (B) on the stability of the refrigerating machine oil was clearly shown. ing. [Effect of the Invention] As described above, the composition of the present invention does not separate from the refrigerant at a low temperature, which is suitable for use in a refrigeration apparatus using 1,1,1,2-tetrafluoroethane as a refrigerant. And a lubricating oil composition for a refrigerating and refrigerating apparatus having good lubricity, sealing properties and stability. In particular, when a polyalkylene glycol monoether having a number average molecular weight within a certain range and a ratio of a weight average molecular weight to a number average molecular weight within a certain range is used as a base oil, the refrigerant can be used not only at a low temperature but also at a high temperature. A lubricating oil composition for a refrigeration unit that does not separate can be obtained.

Claims (1)

[Claims] 1. General formula (Wherein, R ₁ represents an alkyl group having 1 to 18 carbon atoms, a represents an integer of 5 to 70, R ₂ represents an alkylene group having 2 to 4 carbon atoms, and (R The ratio of the number of —OR ₂ — groups in which ₂ is an ethylene group) / a (hereinafter referred to as α) is more than 0 and not more than 0.8), and the pour point is -10 ° C. or less, The kinematic viscosity at 100 ° C. is 2 to (1
0 + 120α) cSt, the number average molecular weight is more than 506 and less than 2000, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.00 to 1.2.
A lubricating oil composition for refrigeration equipment using 1,1,1,2-tetrafluoroethane as a refrigerant, characterized by using polyoxyalkylene glycol monoether which is 0 as a base oil. 2. General formula (Wherein, R ₁ represents an alkyl group having 1 to 18 carbon atoms, a represents an integer of 5 to 70, R ₂ represents an alkylene group having 2 to 4 carbon atoms, and (R The ratio of the number of —OR ₂ — groups in which ₂ is an ethylene group) / a (hereinafter referred to as α) is more than 0 and not more than 0.8), and the pour point is -10 ° C. or less, The kinematic viscosity at 100 ° C. is 2 to (1
0 + 120α) polyoxyalkylene glycol having cSt, a number average molecular weight of less than 2000, and a ratio (Mw / Mn) of weight average molecular weight (Mw) to number average molecular weight (Mn) of 1.00 to 1.20 Monoether is used as a base oil, and based on 100 parts by weight of the base oil, (A) a general formula (Wherein, R ₃ represents an alkyl group having 1 to ₃ carbon atoms, and b represents an integer of 0 to 2) 0.1 to 5.0 parts by weight of a phosphate represented by the following formula: A lubricating oil composition for refrigeration equipment, which uses 1,1,1,2-tetrafluoroethane as a refrigerant. 3. General formula (Wherein, R ₁ represents an alkyl group having 1 to 18 carbon atoms, a represents an integer of 5 to 70, R ₂ represents an alkylene group having 2 to 4 carbon atoms, and -R in the molecule The ratio of the number of —OR ₂ — groups in which ₂ is an ethylene group) / a (hereinafter referred to as α) is more than 0 and not more than 0.8), and the pour point is -10 ° C. or less, The kinematic viscosity at 100 ° C. is 2 to (1
0 + 120α) cSt and the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (
(Mw / Mn) of 1.00 to 1.20 is used as a base oil, and 100 parts by weight of the base oil is represented by the following general formula: (Wherein, R ₃ represents an alkyl group having 1 to ₃ carbon atoms, and b represents an integer of 0 to 2). 0.1 to 5.0 parts by weight of a phosphate represented by the following formula: (B) (i) phenyl 0.1 to 5.0 parts by weight of at least one epoxy compound selected from the group consisting of a glycidyl ether type epoxy compound, (ii) an epoxidized fatty acid monoester, and (iii) an epoxidized vegetable oil is blended as an essential component. A lubricating oil silk product for refrigeration equipment using 1,1,1,2-tetrafluoroethane as a refrigerant. 4. General formula (Wherein, R ₁ represents an alkyl group having 1 to 18 carbon atoms, a represents an integer of 5 to 70, R ₂ represents an alkylene group having 2 to 4 carbon atoms, and (R ₂ Is the number of —OR ₂ — groups in which is an ethylene group) / a (hereinafter α is from 0 to 0.8 or less), and the pour point is -10 ° C. or less and 100 Kinematic viscosity at 2 ° C. is 2 to (1
0 + 120α) cSt, the number average molecular weight is more than 506 and 1500 or less, and the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.00 to 1.2.
A lubricating oil composition for refrigeration equipment using 1,1,1,2-tetrafluoroethane as a refrigerant, characterized by using a polyoxyalkylene glycol monoether as a base oil.