JP3384510B2 - Refrigerator oil and fluid composition for refrigerator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating machine oil and a fluid composition for a refrigerating machine, and more specifically, it contains 1,1,1,2-tetrafluoroethane (HFC-134a) which is an alkylbenzene having specific properties. The present invention relates to a refrigerating machine oil useful as an HFC refrigerant, and a refrigerating machine fluid composition containing the refrigerating machine oil.

[0002]

2. Description of the Related Art Due to the problem of ozone layer depletion in recent years, CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons), which have been conventionally used as refrigerants for refrigeration equipment, are subject to regulation. Fluorocarbons) are being used as refrigerants.

Refrigerating machine oil for this HFC refrigerant is H
PAG (polyalkylene glycol) compatible with FC,
Esters are being studied or used. PA for example
Regarding G, U.S. Pat. No. 4,755,316, JP-A-1
No. 198694, No. 1-256594, No. 1-259093, No. 1-259094,
No. 1-259095, No. 1-274191, No. 2-43290, No. 2-55791, No. 2-84491, etc., and regarding ester, publication No. 3-505602. JP-A-3-88892, JP-A-2-128991, JP-A-3-128992, and JP-A-3-200895,
JP-A-3-227397, JP-A-4-20597,
No. 4-72390, No. 4-218592.
It is described in Japanese Patent Laid-Open No. 4-249959.

However, PAG has a high hygroscopic property, and its electrical characteristics (volume resistivity) are not good. Ester oil may undergo hydrolysis due to its structure and generate an acid, and various inconveniences are expected to occur. In addition, these oils have a serious problem that they are inferior in lubricity as compared with mineral oil / CFC or mineral oil / HCFC systems.

On the other hand, Japanese Patent Laid-Open No. 5-157379 discloses HFC-134 using refrigerating machine oil that is incompatible with the refrigerant.
a Refrigerant refrigeration system is described, and alkylbenzene is mentioned as an incompatible oil. However, the usual alkylbenzene was added to HFC-134a.
When it is used as a refrigerating machine oil, a special devise on the system side is necessary, and when a normal alkylbenzene is used in a refrigeration system for HFC-134a refrigerant without such a devise, long-term operation is possible. It has become clear that seizure of the refrigeration compressor may occur.

The present inventors have focused their attention on alkylbenzene, which has no concern about hydrolysis or hygroscopicity, and as a result of earnest research, as a result, alkylbenzene having a specific property was identified as HFC-1.
The inventors have found that the use of the refrigerating machine oil for the 34a refrigerant does not cause seizure of the refrigerating compressor, has excellent lubricity, and has high reliability over a long period of time, and has completed the present invention.

Furthermore, the present inventors have found that by adding a specific amount of a phosphoric acid ester compound to an alkylbenzene having the above-mentioned specific properties, the wear resistance and load resistance of the compound can be greatly improved. Has been completed.

[0008]

SUMMARY OF THE INVENTION The present invention is based on the HFC-1.
A refrigerating machine oil that can be used for an HFC refrigerant containing 34a, is free from seizure of the refrigeration compressor, has excellent lubricity, and has high reliability over a long period of time, and contains the refrigerating machine oil and HFC-134a. It aims at providing the fluid composition for refrigerators which consists of HFC refrigerant.

[0009]

That is, according to the present invention, 60% by weight of alkylbenzene having a molecular weight of 200 to 350 is used.
Containing alkylbenzene containing more, HFC-134
A refrigerating machine oil for HFC refrigerant containing a.

The present invention also has a molecular weight of 200-350.
Include alkylbenzene containing alkylbenzene 60% by weight or more as the base oil further comprises a refrigerating machine oil based on the total amount of the composition in 0.01 to 5.0 wt% of phosphoric acid ester compounds, HFC containing HFC-134a A refrigerating machine oil composition for a refrigerant is provided.

The present invention also provides [I] HFC-134a.
HFC refrigerant containing, and [II] molecular weight of 200-
A refrigerating machine fluid composition comprising a refrigerating machine oil containing alkylbenzene of 350% by weight or more containing 60% by weight or more.

The present invention also provides [I] HFC-134a.
HFC refrigerant containing, and [II] molecular weight of 200-
Include alkylbenzene containing 350 of alkylbenzene 60% by weight or more as the base oil, further refrigerating machine oil composition in the total amount 0.01 to 5.0% by weight of phosphoric acid ester compound by blending the refrigerator oil composition A fluid composition for a cold-freezer containing the .

The contents of the present invention will be described in detail below. The refrigerator oil of the present invention is an alkylbenzene containing 60% by weight or more of an alkylbenzene having a molecular weight of 200 to 350.

The alkylbenzene has a molecular weight of 20.
It is necessary that the alkylbenzene of 0 to 350 is 60% by weight or more, preferably 65% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, and most preferably 100% by weight. If an alkylbenzene that does not satisfy this condition is used, the refrigeration compressor may seize during long-term operation, which is not preferable because it lacks reliability.

Further, as the alkylbenzene, the alkylbenzene having a molecular weight of 200 to 300 is preferably 30% by weight or more, more preferably 35% by weight or more, from the viewpoint that it is more excellent in the seizure prevention property of the refrigeration compressor particularly under long-term operation. Particularly preferably, it is desirable to contain 40% by weight or more.

The alkylbenzene having a molecular weight of 200 to 350, which is the alkylbenzene as the refrigerating machine oil of the present invention, is not limited in structure as long as the molecular weight is within this range, but the long-term reliability of the refrigeration system is not limited. Therefore, it is preferable that the alkylbenzene (A) has 1 to 4 alkyl groups having 1 to 19 carbon atoms, and the total number of carbon atoms of the alkyl groups is 9 to 19, and further alkyl having 1 to 15 carbon atoms. More preferably, it is an alkylbenzene having 1 to 4 groups and the total number of carbon atoms in the alkyl group is 9 to 15.

Specific examples of the alkyl group having 1 to 19 carbon atoms include a methyl group, an ethyl group, a propyl group (including all isomers) and a butyl group (including all isomers). , Pentyl group (including all isomers), hexyl group (including all isomers), heptyl group (including all isomers), octyl group (including all isomers), nonyl group (all (Including isomers), decyl group (including all isomers), undecyl group (including all isomers), dodecyl group (including all isomers), tridecyl group (including all isomers), Tetradecyl group (including all isomers), pentadecyl group (including all isomers), hexadecyl group (including all isomers), heptadecyl group (including all isomers), octadecyl group ( Including isomers of all), including nonadecyl (all isomers), including eicosyl group (all isomers) and the like.

The alkyl group may be linear or branched, but a branched alkyl group is preferable from the viewpoint of stability, viscosity characteristics and the like, and is particularly available. More preferred are branched alkyl groups derived from olefin oligomers such as propylene, butene, and isobutylene.

The number of alkyl groups in the above-mentioned (A) alkylbenzene is 1 to 4, but from the viewpoint of stability and availability, alkylbenzene having 1 or 2 alkyl groups, that is, monoalkylbenzene, dialkyl Alkylbenzene or a mixture thereof is most preferably used.

Of course, as the alkylbenzene of (A), not only alkylbenzene having a single structure but also 1 to 4 alkyl groups having 1 to 19 carbon atoms and the total number of carbon atoms of the alkyl groups is A mixture of alkylbenzenes having different structures may be used as long as it satisfies the condition of 9 to 19.

The alkylbenzene which is the refrigerating machine oil of the present invention has a molecular weight of less than 200 or a molecular weight of 350.
May be contained in an amount of less than 40% by weight, preferably less than 35% by weight, and more preferably less than 30% by weight. However, these alkylbenzenes may be contained because of their reliability during long-term operation of the compressor. Molecular weight is 350
Alkylbenzene having a molecular weight of more than 450 and 450 or less is preferable, and an alkylbenzene having a molecular weight of more than 350 and 430 or less is more preferable.

The structure of the alkylbenzene having a molecular weight of more than 350 and not more than 450 is not limited as long as the molecular weight is within this range. However, from the viewpoint of stability and availability, it has 1 carbon atom. 1 to 40 alkyl groups
It has 4 and the total number of carbon atoms of the alkyl group is 20 to 4
Alkylbenzene (B) which is 0 is preferred,
Furthermore, it is more preferable that the alkylbenzene has 1 to 4 alkyl groups having 1 to 30 carbon atoms and the total number of carbon atoms of the alkyl groups is 20 to 30.

Specific examples of the alkyl group having 1 to 40 carbon atoms include methyl group, ethyl group, propyl group (including all isomers) and butyl group (including all isomers). , Pentyl group (including all isomers), hexyl group (including all isomers), heptyl group (including all isomers), octyl group (including all isomers), nonyl group (all (Including isomers), decyl group (including all isomers), undecyl group (including all isomers), dodecyl group (including all isomers), tridecyl group (including all isomers), Tetradecyl group (including all isomers), pentadecyl group (including all isomers), hexadecyl group (including all isomers), heptadecyl group (including all isomers), octadecyl group ( All isomers), nonadecyl group (including all isomers), icosyl group (including all isomers), henicosyl group (including all isomers), docosyl group (all isomers) Including), tricosyl group (including all isomers), tetracosyl group (including all isomers), pentacosyl group (including all isomers), hexacosyl group (including all isomers), heptacosyl group ( All isomers), Octacosyl group (all isomers), Nonacosyl group (all isomers), Triacontyl group (all isomers), Hentriacontyl group (all isomers) ,), Dotriacontyl group (including all isomers), tritriacontyl group (including all isomers), tetratriacontyl group (all isomers) Including), pentatriacontyl group (including all isomers), hexatriacontyl group (including all isomers), heptatriacontyl group (including all isomers), octatriacontyl group (Including all isomers), nonatriacontyl group (including all isomers), tetracontyl group (including all isomers), and the like.

The alkyl group may be linear or branched, but a branched alkyl group is preferable from the viewpoints of stability, viscosity characteristics, etc., and is particularly available. More preferred are branched alkyl groups derived from olefin oligomers such as propylene, butene, and isobutylene.

The number of the alkyl groups in the above-mentioned (B) alkylbenzene is 1 to 4, but from the viewpoint of stability and availability, alkylbenzene having 1 or 2 alkyl groups, that is, monoalkylbenzene, dialkyl is included. Alkylbenzene or a mixture thereof is most preferably used.

Of course, as the alkylbenzene of (B), not only alkylbenzene having a single structure but also 1 to 4 alkyl groups having 1 to 40 carbon atoms and the total number of carbon atoms of the alkyl groups is A mixture of alkylbenzenes having different structures may be used as long as it satisfies the condition of 20 to 40.

The viscosity of the alkylbenzene which is the refrigerating machine oil of the present invention is not particularly limited, but the preferred kinematic viscosity is 40 ° C.
At 3 to 50 mm ² / s, more preferably 4 to 40 mm ²
/ S, and particularly preferably 5-35 mm ² / s.

The method for producing the alkylbenzene which is the refrigerating machine oil of the present invention is arbitrary and is not limited in any way, but generally it can be produced by the following synthetic method.

Specific examples of the aromatic compound as a raw material include benzene, toluene, xylene, ethylbenzene, methylethylbenzene, diethylbenzene, and mixtures thereof. As the alkylating agent, specifically, for example, ethylene, propylene,
Lower monoolefins such as butene and isobutylene, preferably 6 to 40 carbon atoms obtained by polymerization of propylene
Linear or branched olefins; waxes, heavy oils, petroleum fractions, polyethylene, polypropylene, and other linear or branched olefins having 6 to 40 carbon atoms; kerosene, gas oil A linear olefin having 6 to 40 carbon atoms obtained by separating n-paraffin from a petroleum fraction such as the above and converting it into an olefin with a catalyst; and mixtures thereof can be used.

As the alkylation catalyst for the alkylation, Friedel-Crafts type catalysts such as aluminum chloride and zinc chloride; acidic catalysts such as sulfuric acid, phosphoric acid, silicotungstic acid, hydrofluoric acid and activated clay; Known catalysts are used.

The alkylbenzene of the present invention is obtained, for example, by mixing separately produced alkylbenzene having a molecular weight of 200 to 350 and alkylbenzene having a molecular weight of less than 200 or having a molecular weight of more than 350 in a ratio within the range specified by the present invention. However, a method for obtaining a fraction containing 60% by weight or more of an alkylbenzene having a molecular weight of 200 to 350 by separating an alkylbenzene mixture obtained by the method as exemplified above or a commercially available alkylbenzene mixture by distillation or chromatography. However, it is practically convenient.

The refrigerating machine oil according to the present invention comprises the above-mentioned alkylbenzene, and can be suitably used as a refrigerating machine oil for HFC refrigerant containing HFC-134a even in a state where no additive is added. It can also be used in the form of a refrigerating machine oil composition containing additives.

In particular, in order to further improve the wear resistance and load bearing capacity of the refrigerating machine oil of the present invention, phosphoric acid ester, acidic phosphoric acid ester, amine salt of acidic phosphoric acid ester, chlorinated phosphoric acid ester and phosphorous acid. It is preferable to blend at least one phosphoric acid ester compound selected from the group consisting of acid esters.

These phosphoric acid ester compounds are esters of phosphoric acid or phosphorous acid with alkanols, polyether type alcohols or derivatives thereof.

Specific examples of the phosphoric acid ester include 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 Examples thereof include phosphate and xylenyldiphenyl phosphate. As the acidic phosphate, 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 Phosphate, Dihexyl Acid Phosphate, Diheptyl Acid Phosphate, Dioctyl Acid Phosphate, Dinonyl Acid Phosphate, Didecyl Acid Phosphate, Diundecyl Acid Phosphate, Didodecyl Acid Phosphate, Ditridecyl Acid Phosphate, Ditetradecyl Acid Phosphate,
Examples thereof include dipentadecyl acid phosphate, dihexadecyl acid phosphate, diheptadecyl acid phosphate, dioctadecyl acid phosphate, dioleyl acid phosphate, and the like. The amine salt of acidic phosphoric acid ester includes methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine of the acidic phosphoric acid ester. Examples thereof include salts with amines such as dipentylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine and trioctylamine. Examples of the chlorinated phosphoric acid ester include tris-dichloropropyl phosphate, tris-chloroethyl phosphate, tris-chlorophenyl phosphate, polyoxyalkylene bis [di (chloroalkyl)] phosphate and the like. Examples of the phosphite include 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 Fight, tridodecyl phosphite,
Examples include trioleyl phosphite, triphenyl phosphite, tricresyl phosphite, and the like. Also,
Mixtures of these can also be used.

When these phosphoric acid ester compounds are compounded in the refrigerating machine oil of the present invention, the compounding amount is arbitrary, but usually, the refrigerating machine oil composition total amount standard (the total of alkylbenzene of the present invention and all compounding additives is added). The content is 0.005 to 5.0% by weight, and more preferably 0.01 to 5.0% by weight.
It is desirable to add an amount of 3.0% by weight.

When the amount of the phosphoric acid ester compound is less than 0.005% by weight based on the total amount of the refrigerating machine oil composition, the effect of improving the wear resistance and load resistance by the compounding of the phosphoric acid ester compound is poor. However, if the blending amount exceeds 5.0% by weight based on the total amount of the refrigerating machine oil composition, corrosion may occur in the refrigeration system when used for a long period of time, which is not preferable.

It is one of the characteristics of the refrigerating machine oil of the present invention that the wear resistance and load bearing capacity are greatly improved by blending these phosphoric acid ester compounds. In PAG (polyalkylene glycol) and ester known as refrigerating machine oil for HFC, although abrasion resistance and load resistance are improved to some extent by blending a phosphoric acid ester-based compound, the effect thereof is that of the present invention. It is extremely small compared to refrigeration oil.

In order to further improve the stability of the refrigerating machine oil of the present invention, a phenyl glycidyl ether type epoxy compound, an alkyl glycidyl ether type epoxy compound, a glycidyl ester type epoxy compound, an allyl oxirane compound, an alkyl oxirane compound, At least one epoxy compound selected from the group consisting of alicyclic epoxy compounds, epoxidized fatty acid monoesters, and epoxidized vegetable oils can be blended.

Specific examples of the phenylglycidyl ether type epoxy compound include phenylglycidyl ether and alkylphenylglycidyl ether. The alkylphenyl glycidyl ether as used herein has 1 to 3 alkyl groups having 1 to 13 carbon atoms, and particularly 1 alkyl group having 4 to 10 carbon atoms.
Having one, for example, n-butylphenyl glycidyl ether, i-butylphenyl glycidyl ether, se
Examples thereof include c-butyl phenyl glycidyl ether, tert-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.

Specific examples of the alkyl glycidyl ether type epoxy compound include decyl glycidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, 2-ethylhexyl glycidyl ether, neopentyl glycol diester. Glycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether,
Examples thereof include 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,
Examples thereof include alkyl glycidyl ester and alkenyl glycidyl ester, and preferable examples include glycidyl 2,2-dimethyloctanoate, glycidyl benzoate, glycidyl acrylate, glycidyl methacrylate and the like.

Specific examples of the allyloxirane include 1,2-epoxystyrene and alkyl-1,2-epoxystyrene.

Specific examples of the alkyl oxirane include 1,2-epoxybutane, 1,2-epoxypentane, 1,2-epoxyhexane, 1,2-epoxyheptane, 1,2-epoxyoctane, 1, 2-epoxynonane, 1,2-epoxydecane, 1,2-epoxyundecane, 1,2-epoxydodecane, 1,2-epoxytridecane, 1,2-epoxytetradecane, 1,2.
-Epoxypentadecane, 1,2-epoxyhexadecane, 1,2-epoxyheptadecane, 1,1,2-epoxyoctadecane, 2-epoxynonadecane, 1,2-
Epoxy icosane etc. can be illustrated.

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-methylcyclohexane,
4-epoxyethyl-1,2-epoxycyclohexane etc. can be illustrated.

As the epoxidized fatty acid monoester, specifically, epoxidized fatty acid having 12 to 20 carbon atoms and alcohol or phenol having 1 to 8 carbon atoms,
Examples thereof include esters with alkylphenols. Especially epoxy stearic acid butyl, hexyl, benzyl,
Cyclohexyl, methoxyethyl, octyl, phenyl and butylphenyl esters are preferably used.

Specific examples of epoxidized vegetable oils include epoxy compounds of vegetable oils such as soybean oil, linseed oil and cottonseed oil.

Among these epoxy compounds, preferred are phenyl glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, alicyclic epoxy compounds and epoxidized fatty acid monoesters. Among them, phenyl glycidyl ether type epoxy compounds and glycidyl ester type epoxy compounds are more preferable, and phenyl glycidyl ether, butyl phenyl glycidyl ether, alkyl glycidyl ester or a mixture thereof is particularly preferable.

When these epoxy compounds are blended with the refrigerating machine oil of the present invention, the blending amount is optional, but usually,
The refrigerating machine oil composition has a content of 0.1 to 0.1 on the basis of the total amount (based on the total amount of the alkylbenzene of the present invention and all compounding additives)
It is desirable to add such an amount that the amount is 5.0% by weight, more preferably 0.2 to 2.0% by weight.

It is needless to say that two or more kinds of the above phosphorus compound and epoxy compound may be used in combination.

Further, for the refrigerating machine oil in the present invention,
In order to further enhance its performance, conventionally known refrigerating machine oil additives, such as di-tert-butyl-p, are added as needed.
-Phenolic compounds such as cresol and bisphenol A, phenyl-α-naphthylamine, amine-based antioxidants such as N, N-di (2-naphthyl) -p-phenylenediamine, antiwear agents such as zinc dithiophosphate, Extreme pressure agents such as chlorinated paraffins and sulfur compounds, oil agents such as fatty acids, defoaming agents such as silicones, metal deactivators such as benzotriazole, viscosity index improvers, pour point depressants, detergent dispersants, etc. It is also possible to mix the above additives alone or in combination of several kinds. The total compounding amount of these additives is usually 10% by weight or less, preferably 5% by weight or less, based on the total amount of the refrigerating machine oil composition (based on the total amount of the alkylbenzene of the present invention and all the compounding additives).

The refrigerant used in the refrigerator using the refrigerator oil of the present invention is a fluoroalkane having 1 to 3 carbon atoms, preferably 1 to 2 carbon atoms, and 1,1,1,2-tetrafluoroethane (HFC- 134a) 50% by weight or more (however, H
(Excluding the case of containing FC-125 in an amount of 20% by weight or more).

HFC (hydrofluorocarbon) which can be mixed with HFC-134a is not particularly limited, but specifically, for example, trifluoromethane (HFC-23),
Difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1-trifluoroethane (HFC-143a), 1 , 1-difluoroethane (HFC-152a) and the like.

More specifically, the HFC refrigerant containing HFC-134a in the present invention is, for example, HFC-
134a alone; HFC-134a / HFC-32 = 60
-80 wt% / 40-20 wt% mixture; HFC-1
34a / HFC-32 / HFC-125 = 50 to 70% by weight / 15 to 35% by weight / 5 to 19.99% by weight mixture; and the like.

The refrigerator oil according to the present invention is usually present in the refrigerator in the form of a refrigerator composition mixed with the above-mentioned fluoroalkane. The mixing ratio of the refrigerating machine oil and the refrigerant in this composition is arbitrary, but usually,
Refrigerating machine oil 1 to 500 parts by weight with respect to 100 parts by weight of the refrigerant,
It is preferably 2 to 400 parts by weight.

The refrigerating machine oil of the present invention is particularly preferably used for an air conditioner or a refrigerator having a reciprocating or rotating hermetic compressor because of its excellent electric characteristics and low hygroscopicity. Also, automotive air conditioners, dehumidifiers, freezers, freezers,
It is particularly preferably used for cooling devices for vending machines, showcases, chemical plants, and the like. Further, it is also preferably used for those having a centrifugal compressor.

[0057]

EXAMPLES The contents of the present invention will be described more specifically below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Table 1 shows the properties of the base oils used in Examples 1 to 12 and Comparative Examples 1 to 9 and Table 2 and the contents of the additives. The molecular weight distribution of the alkylbenzene mixture was measured by mass spectrum.

[0059]

[Table 1]

A, C, D, E, F, H: all produced by using a hydrofluoric acid catalyst with benzene and a branched olefin having a carbon number of 6 to 24 and consisting of a dimer to a propylene of 6 to 24 as a raw material. Distilled mixture of monoalkylbenzene and dialkylbenzene. B: 50% by weight / 50% by weight mixture of A and E. G: H redistilled. I, J: Both have 9 to 1 carbon atoms from benzene and kerosene fraction
A product obtained by distilling a mixture of monoalkylbenzene and dialkylbenzene produced by using a hydrofluoric acid catalyst as a raw material obtained by separating n-paraffin of 8 above.

[0061]

[Table 2]

Refrigerating machine oils according to the present invention were prepared according to the compositions shown in Table 3 (Examples 1 to 12).

These refrigerating machine oils were subjected to the following long-term operability evaluation test, and the results are also shown in Table 3.

[Evaluation test 1] Using a room air conditioner for home use with a cooling capacity of 2.5 kw, 350 g of test oil and HFC
-134a / HFC-32 = 70 wt% / 30 wt% mixed refrigerant 1000 g was charged and placed in a thermostatic chamber maintained at an ambient temperature of 43 ° C., and the temperature of the air conditioner was set to 25 ° C.
The continuous operation was performed for 00 hours, and the drivability was evaluated.

[Evaluation Test 2] Using a household three-door refrigerator with an effective internal volume of about 300 L, 150 g of test oil and HFC were used.
180g of -134a was filled and placed in a thermostatic chamber maintained at an atmospheric temperature of 43 ° C, and the operation was evaluated by setting the freezing room at -18 ° C and the refrigerating room at 3 ° C for 500 hours of continuous operation.

[Evaluation Test 3] With respect to the test oils that showed good performances in both the performance evaluation test 1 and the performance evaluation test 2, 70g of the test oil and 50g of HFC-134a were filled using a rolling piston compressor, and the discharge pressure was 16kgf. / Cm ² G, suction pressure 0 kgf / cm ² G,
Rotation speed 3000 rpm, test temperature 160 ℃ 10
After continuous operation for 00 hours, the surface roughness of the sliding surface of the vane of the compressor after 1000 hours was measured.

For comparison, according to the composition of Table 4, the content of alkylbenzene having a molecular weight of 200 to 350 is 60.
When the alkylbenzene mixture of less than wt% was used alone (Comparative Example 1 and Comparative Example 3), the molecular weight was 200-35.
When an additive was added to an alkylbenzene mixture having an alkylbenzene content of 0 of less than 60% by weight (Comparative Example 2).
And Comparative Example 4), when an additive was blended with a naphthenic mineral oil (Comparative Example 5), when pentaerythritol ester was used alone (Comparative Example 6), and when an additive was blended with pentaerythritol ester (Comparative Example). 7), when polypropylene glycol monoalkyl ether was used alone (Comparative Example 8) and when polypropylene glycol monoalkyl ether was blended with an additive (Comparative Example 9).
The same evaluation test was carried out for the same, and the results are also shown in Table 4.

[0068]

[Table 3]

[0069]

[Table 4]

As is clear from the results of the performance evaluation test in Table 3, the refrigerating machine oils of Examples 1 to 12 according to the present invention did not cause seizure of the refrigeration compressor, were excellent in lubricity, and were high over a long period of time. You can see that reliability is obtained.

In particular, the refrigerating machine oil compositions of Examples 7 to 12 were prepared by further incorporating a phosphoric acid ester compound, but compared with the refrigerating machine oils of Examples 1 to 6, the sliding surface of the vane of the compressor was The surface roughness is greatly improved, and it is clear that the phosphoric acid ester-based compound is very effective in improving the abrasion resistance.

On the other hand, the refrigerating machine oils of Comparative Examples 1 to 4 shown in Table 4 were obtained by using the alkylbenzene mixture having a molecular weight of 200 to 350 and an alkylbenzene content of less than 60% by weight. Seizure occurs, and long-term reliability cannot be obtained. Further, this image sticking is not improved even by blending a phosphate compound. This tendency is the same in Comparative Example 5 using naphthene-based mineral oil.

On the other hand, Comparative Example 6 is a case where pentaerythritol ester is used alone and Comparative Example 8 is a case where polypropylene glycol monoalkyl ether is used alone. Although seizure of the refrigerating compressor does not occur, It is much inferior in wear resistance to the refrigerator oil of the present invention.

Comparative Examples 7 and 9 are Comparative Example 6
And the case where the phosphoric acid ester compound was further added to the refrigerating machine oil of Comparative Example 8, the abrasion resistance thereof was hardly improved, and the base oil (having a molecular weight of 20
It is clear that the synergistic effect of the phosphoric acid ester-based compound and the alkylbenzene containing 0 to 350 alkylbenzene in an amount of 60% by weight or more.

[0075]

As described above, the refrigerating machine oil of the present invention can be used for the HFC refrigerant containing HFC-134a, does not cause seizure of the refrigerating compressor, has excellent lubricity, and has a long-term property. High reliability can be obtained throughout. Then, this refrigerating machine oil is used as an HFC containing HFC-134a.
By being mixed with a refrigerant, it is preferably used as a fluid composition for a refrigerator.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C10M 137: 04) C10N 20:04 C10N 20:04 30:06 30:06 40:30 40:30 (56) References JP-A-3-157477 (JP, A) JP-A-1-115998 (JP, A) JP-A1-115999 (JP, A) JP-A-2-170895 (JP, A) JP-A-49-97351 (JP , A) JP-A-53-104608 (JP, A) JP-A-61-296093 (JP, A) JP-A-57-177097 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB) (Name) C10M 105/06 C10M 137/04-137/10 C10M 169/04 C10N 20:04 C10N 30:06 C10N 40:30 C09K 5/04

Claims (4)

(57) [Claims] 1. An alkylbenzene containing 60% by weight or more of an alkylbenzene having a molecular weight of 200 to 350 is contained.
A refrigerating machine oil for HFC refrigerant containing HFC-134a. 2. A base oil comprising an alkylbenzene having an alkylbenzene having a molecular weight of 200 to 350 in an amount of 60% by weight or more , and further , 0.00 based on the total amount of the refrigerating machine oil composition.
H containing 5 to 5.0% by weight of a phosphate compound
Refrigerating machine oil composition for HFC refrigerants containing FC-134a. 3. HF containing [I] HFC-134a
C refrigerant and [II] alkylbenzene containing 60 wt% or more of alkylbenzene having a molecular weight of 200 to 350
A fluid composition for a refrigerating machine, the refrigerating machine oil containing: 4. HF containing [I] HFC-134a
C refrigerant and [II] the molecular weight comprises as an alkylbenzene a base oil containing at least 60 wt% of the alkylbenzene of 200-350, more phosphoric acid esters of 0.005-5.0 wt% in the refrigerator oil composition the total amount Based compounds
Refrigerating machine oil composition comprising, refrigeration fluid compositions comprising a.