JP2002060770A - Lubricating oil composition for refrigerator and working fluid composition for refrigerator using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerating machine oil lubricating oil composition exhibiting particularly excellent compatibility with difluoromethane, and to include the lubricating oil composition for a refrigerating machine and the above-mentioned refrigerant, and to provide wear resistance, lubricating properties and To provide a working fluid composition for a refrigerator having excellent stability and the like. SOLUTION: The lubricating oil composition for a refrigerator using a chlorine-free refrigerant having 1 carbon atom and containing a polyoxyalkylene glycol derivative having a specific substituent as a main component as a base oil, and (a) polyvinyl as a base oil An ether derivative, and (b) the above polyoxyalkylene glycol derivative
When the refrigerant containing 0.1% by weight or more and less than 60% by weight and containing no chlorine and having 1 carbon atom is contained in the range of 3 to 50% by weight based on the total amount, the content is , A lubricating oil composition for a refrigerator having a low-temperature two-layer separation temperature of 5 ° C or lower, and (A) a chlorine-free carbon number 1
And (B) a working fluid composition for a refrigerator comprising the lubricating oil composition for a refrigerator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lubricating oil composition for a refrigerator and a working fluid composition for a refrigerator using the same. More specifically, the present invention relates to a lubricating oil composition for refrigerators having excellent compatibility with chlorine-free refrigerants having 1 carbon atom, particularly difluoromethane, and a lubricating oil composition for refrigerators and the refrigerant described above. And a working fluid composition for a refrigerator having excellent wear resistance, lubricating properties, electrical properties, stability, and the like.

[0002]

2. Description of the Related Art In general, a compression refrigerator comprises at least a compressor, a condenser, an expansion mechanism (expansion valve, etc.), an evaporator, or a dryer. It has a structure that circulates inside. In such a compression type refrigerator, although it depends on the type of equipment, generally, the temperature in the compressor is high and the temperature in the cooler is low, so the refrigerant and lubricating oil phase-separate within a wide temperature range from low to high. It is necessary to circulate in this system without doing. In general, the refrigerant and the lubricating oil have a region where phase separation occurs on the low temperature side and the high temperature side, and the maximum temperature of the low temperature side separation region is preferably 5 ° C or less, more preferably 3 ° C or less, and more preferably 0 ° C. or lower, more preferably −
2 ° C. or less. If phase separation occurs during the operation of the refrigerator, the life and efficiency of the device will be significantly adversely affected. For example, when the phase separation of the refrigerant and the lubricating oil occurs in the compressor part, the moving part becomes inadequately lubricated, causing seizure or the like to significantly shorten the life of the device, while the phase separation occurs in the evaporator, The presence of the lubricating oil having a high viscosity causes a reduction in the efficiency of heat exchange.

[0003] Conventionally, as a refrigerant of a compression refrigerator, particularly an air conditioner, chlorodifluoromethane (hereinafter referred to as R22) or a chlorodifluoromethane and chloropentafluoroethane having a weight ratio of 48.8: 51.2. Mixture (hereinafter,
Called R502. ) Is often used, and as the lubricating oil, various mineral oils and synthetic oils satisfying the above-mentioned required characteristics have been used. However, since R22 and R502 may cause environmental pollution such as destruction of the ozone layer existing in the stratosphere, the regulations thereof have recently become stricter worldwide. Therefore, as a new refrigerant 1,
1,1,2-tetrafluoroethane, difluoromethane, pentafluoroethane, 1,1,1-trifluoroethane (hereinafter, R134a, R32, R12
5, R143a. ) Is attracting attention. This hydrofluorocarbon, especially R134a,
R32, R125, and R143a have no risk of destruction of the ozone layer and are preferred as refrigerants for compression refrigerators.

Further, from the viewpoint of energy saving, further measures have been required, and among the above-mentioned new refrigerants,
In particular, difluoromethane (R32) has attracted attention. However, the R32 refrigerant has a higher working pressure and temperature than conventional refrigerants, and is likely to cause new lubrication problems. In lubricating oils for refrigerators, which have been studied so far for the new refrigerant, the R
In fact, none of them show sufficient compatibility with R.32, and R134a, R407c, (a mixture of R32, R125, and R134a in a weight ratio of 23:24:52), R
The development of a lubricating oil for refrigerators having the same level of compatibility as 410A (a mixture of R32 and R125 at a weight ratio of 50:50) has been awaited.

[0005]

SUMMARY OF THE INVENTION Under such circumstances, the present invention provides a lubricating oil for a refrigerator having excellent compatibility with a chlorine-free refrigerant having 1 carbon atom, particularly difluoromethane (R32). An object of the present invention is to provide a composition and a working fluid composition for a refrigerator including the lubricating oil composition for a refrigerator and the above-described refrigerant, and having excellent wear resistance, lubricating properties, stability, and the like.

[0006]

Means for Solving the Problems The present inventors have heretofore described R32 of a polyether compound such as a polyoxyalkylene glycol derivative or a polyvinyl ether derivative, or an oxygen-containing compound such as a polyol ester derivative.
Although the compatibility under a refrigerant atmosphere has been studied, it cannot be said that these compounds necessarily have sufficient compatibility with R32. The present inventors have further studied diligently to achieve the above object, and as a result, have a predetermined viscosity, and a polyoxyalkylene glycol derivative itself having a specific substituent, or a polyvinyl having a predetermined viscosity. A mixture obtained by mixing the above-mentioned polyoxyalkylene glycol derivative with an ether derivative in a specific ratio has excellent compatibility with a chlorine-free refrigerant having 1 carbon atom, in particular, R32. It has been found that those containing a refrigerant can meet the above purpose as a working fluid composition for a refrigerator. The present invention has been completed based on such findings. That is, the present invention provides (1) a base oil represented by the general formula (I):

[0007]

Embedded image

[Wherein, R ^{1 to} R ⁴ each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms or a general formula (I)
I)

[0009]

Embedded image

(R ⁵ and R ⁶ each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms or a carbon atom having 2 to 2 carbon atoms.
0 is an alkoxyalkyl group, R ⁷ is an alkylene group having 2 to 5 carbon atoms, and 2 carbon atoms having an alkyl group as a substituent.
A substituted alkylene group or a substituted alkylene group having 4 to 10 carbon atoms as a substituent, wherein R ⁸ is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and n is 0 to 5
It is an integer of 20. ) Represents a group represented by R ^{1 to} R ⁴
Is a group represented by the general formula (II). ]
A chlorine-free carbon, characterized by containing, as a main component, a polyoxyalkylene glycol derivative having at least one structural unit represented by the formula: and having a kinematic viscosity at 40 ° C of 3 to 500 mm ² / s. The lubricating oil composition for a refrigerator using a refrigerant of Formula 1 (hereinafter referred to as lubricating oil composition I for a refrigerator), (2) as a base oil, (a) 40 ° C.
(B) a kinematic viscosity at 40 ° C. of 3 to 500 mm ² / s based on a polyvinyl ether derivative having a kinematic viscosity of 3 to 500 mm ² / s and a total volume of the base oil represented by the general formula (I). 0.1% by weight or more of polyoxyalkylene glycol derivative having at least one unit of 60
A lubricating oil composition for refrigerators containing less than 3% by weight, based on the total amount of a chlorine-free refrigerant having 1 carbon atom.
When contained in a range of 50% by weight, the lubricating oil composition for a refrigerator (hereinafter, referred to as a refrigerator) is characterized in that at any one of the content rates, the two-layer separation temperature on the low temperature side is 5 ° C. or less. Lubricating oil composition II), and

(3) (A) a refrigerant having 1 carbon atom having no chlorine and (B) a working fluid composition for a refrigerator, comprising the lubricating oil composition I or II for a refrigerator. To provide. The use conditions of the lubricating oil composition for a refrigerator of the present invention are as follows: a refrigerant having no chlorine and having 1 carbon atom, particularly a fluorinated hydrocarbon-based refrigerant containing no chlorine, having a high internal pressure and a high operating temperature. Tends to be higher. Therefore, if necessary the hardness difference between the members forming the metal sliding portion of the compression mechanism is set to 10 or more H _RC equivalent, the side of a small member of hardness securing the wear resistance of conventional by conventional hardness Meanwhile, by improving the wear resistance of the other member sufficiently than before, the wear resistance of the required portion of the metal sliding portion is improved, and the fluorocarbon refrigerant does not contain chlorine. The resistance to the fact that the lubrication effect cannot be expected is obtained.
In addition, the fact that the sliding member on the higher hardness side easily promotes the wear of the sliding member on the lower hardness side is determined by at least one of orthophosphate, phosphite, and acid phosphate. It is considered that the addition of the compound compensates for insufficient lubrication due to the fact that the fluorocarbon-based refrigerant does not contain chlorine by acting as an extreme pressure agent.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The working fluid composition for a refrigerator according to the present invention has two aspects, namely, a working fluid composition I for a refrigerator.
And II. First, the lubricating oil composition I for a refrigerator will be described. The lubricating oil composition I for a refrigerator according to the present invention is used for a refrigerator using a refrigerant having no chlorine and having a carbon number of 1 and having a general formula (I) as a base oil.

[0013]

Embedded image

A polyoxyalkylene glycol derivative having at least one structural unit represented by the formula:
A lubricating oil composition containing, as a main component, one having a kinematic viscosity at 0 ° C. of 3 to 500 mm ² / s. In the general formula (I), R ^{1 to} R ⁴ each represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms or a general formula (II)

[0015]

Embedded image

The group represented by The monovalent hydrocarbon group having 1 to 10 carbon atoms among R ^{1 to} R ⁴ is generally an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, and a cycloalkyl having 5 to 10 carbon atoms. Group, carbon number 6-1
It represents an aryl group having 0 or an aralkyl group having 7 to 10 carbon atoms. Specifically, methyl group, ethyl group, n-propyl group, isopropyl group, various butyl groups, various pentyl groups,
Various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups and other alkyl groups, vinyl groups,
Allyl groups, propenyl groups, isopropenyl groups, various butenyl groups, various pentenyl groups, various hexenyl groups, various heptenyl groups, various octenyl groups, various nonenyl groups, various alkenyl groups such as decenyl groups, cyclopentyl groups, cyclohexyl groups, and other cycloalkyl groups Examples include an aryl group such as an alkyl group, a phenyl group, various tolyl groups, various xylyl groups, and a naphthyl group, and an aralkyl group such as a benzyl group, a 1-phenylethyl group, and a 2-phenylethyl group.
Among these, a monovalent hydrocarbon group having 6 or less carbon atoms is preferable, and an alkyl group having 3 or less carbon atoms is most preferable.

In the general formula (II), R ⁵ and R ⁶ each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms or an alkoxyalkyl group having 2 to 20 carbon atoms. Here, the monovalent hydrocarbon group having 1 to 20 carbon atoms is preferably a monovalent hydrocarbon group having 1 to 10 carbon atoms, and specific examples thereof include a monovalent hydrocarbon group having 1 to 10 carbon atoms in R ^{1 to} R ⁴ . The same ones as exemplified in the description of the group can be exemplified. The monovalent hydrocarbon group is preferably a group having 6 or less carbon atoms, and particularly preferably an alkyl group having 3 or less carbon atoms. Examples of the alkoxyalkyl group having 2 to 20 carbon atoms include a methoxymethyl group, an ethoxymethyl group, an n-propoxymethyl group, an isopropoxymethyl group, various butoxymethyl groups, various pentoxymethyl groups, various hexoxymethyl groups, Various heptoxymethyl groups, various octoxymethyl groups, various nonyloxymethyl groups, 1-methoxyethyl groups, 2-methoxyethyl groups,
-Ethoxyethyl group, 2-ethoxyethyl group, various propoxyethyl groups, various butoxyethyl groups, various pentoxyethyl groups, various hexoxyethyl groups, various heptoxyethyl groups, various octoxyethyl groups, various methoxypropyl groups, various ethoxypropyl groups , Various propoxypropyl groups, various butoxypropyl groups, various pentoxypropyl groups, various hexoxypropyl groups, various heptoxypropyl groups, various methoxybutyl groups, various ethoxybutyl groups, various propoxybutyl groups, various butoxybutyl groups,
Various pentoxybutyl groups, various hexoxybutyl groups, various methoxypentyl groups, various ethoxypentyl groups, various propoxypentyl groups, various butoxypentyl groups, various pentoxypentyl groups, various methoxyhexyl groups, various ethoxyhexyl groups, various propoxyhexyl groups And alkoxyalkyl groups such as various butoxyhexyl groups, various methoxyheptyl groups, various ethoxyheptyl groups, various propoxyheptyl groups, various methoxyoctyl groups, various ethoxyoctyl groups, and various methoxynonyl groups. Among them, an alkoxyalkyl group having 6 or less carbon atoms is preferable.

On the other hand, R ⁷ is an alkylene group having 2 to 5 carbon atoms, a substituted alkylene group having 2 to 5 carbon atoms having an alkyl group as a substituent or a C 4 to 10 carbon atom having a total alkylene group or an alkoxyalkyl group as a substituent. Shows a substituted alkylene group. Examples of such an alkylene group include an ethylene group; a 1-methylethylene group: an ethylethylene group;
-Dimethylethylene group; 1,2-dimethylethylene group;
n-propylethylene group; isopropylethylene group; 1
-Ethyl-2-methylethylene group; 1-ethyl-1-methylethylene group; trimethylene group; tetramethylene group;
Pentamethylene group; (methoxymethyl) ethylene group;
(Ethoxymethyl) ethylene group; (methoxyethyl) ethylene group; 1-methoxymethyl-2-methylethylene group; 1,2- (bismethoxymethyl) ethylene group;
1- (bismethoxymethyl) ethylene group; (ethoxyethyl) ethylene group; 1,2- (bisethoxyethyl) ethylene group; 2-methoxy-1,3-propylene group, and the like. It is a substituted ethylene group having 6 or less carbon atoms. Also, R ⁸ represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, and specific examples thereof include the R ¹
The same as those exemplified in the description of the monovalent hydrocarbon group having 1 to 10 carbon atoms in R ⁴ can be given. As R ⁸ , a hydrocarbon group having 6 or less carbon atoms is preferable, and an alkyl group having 3 or less carbon atoms is particularly preferable. n
Is an integer of 0 to 20.

The above R ^{1 to} R ⁴ may be the same or different, and at least one of them is a group represented by the general formula (II). In particular, R ¹
And a group of any one of R ³ are represented by the formula (II), the remaining one of R ¹ and R ³ and R ² and R
⁴ is preferably a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. In the lubricating oil composition I of the present invention, the polyoxyalkylene glycol derivative used as a main component of the base oil contains at least one of the structural units represented by the general formula (I). Is a homopolymer comprising the structural unit of the general formula (I), a copolymer comprising two or more different structural units contained in the general formula (I), and a structural unit of the general formula (I) Unit, for example, general formula (III)

[0020]

Embedded image

(Wherein R ^{9 to} R ¹² each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms). be able to. Preferable examples of the homopolymer include 1 to 200 structural units A represented by the general formula (I), and each of the terminal groups has a hydroxyl group, an acyloxy group having 1 to 10 carbon atoms, and an end group having 1 to 10 carbon atoms. Those comprising an alkoxy group or an aryloxy group can be exemplified. On the other hand, preferred examples of the copolymer include 1 to 200 units of each of the two types of structural units A and B represented by the general formula (I), or the structural unit A represented by the general formula (I) It has 1 to 200 structural units C represented by the general formula (III) and 1 to 200 structural units, each having a terminal group of a hydroxyl group, an acyloxy group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms or aryloxy. There can be mentioned those derived from groups. In these copolymers, the constitutional unit B is graft-bonded to the main chain of the constitutional unit A and the constitutional unit B (or constitutional unit C) alternate copolymer, random copolymer, block copolymer or constitutional unit A. There are various types such as grafted copolymers. The polyoxyalkylene glycol derivative used as a main component in the base oil in the lubricating oil composition for refrigerator I of the present invention can be produced, for example, by the following method. (X) Method general formula (IV)

[0022]

Embedded image

(Wherein R ^{1 to} R ⁴ are the same as described above), and a polyoxyalkylene glycol derivative can be obtained by homopolymerizing or copolymerizing two or more thereof. . Further, an oxirane compound represented by the above general formula (IV) and a general formula (V)

[0024]

Embedded image

(Wherein R ^{9 to} R ¹² are the same as described above) by copolymerizing an alkylene oxide having 2 to 8 carbon atoms, such as ethylene oxide or propylene oxide, to obtain a polyoxyalkylene glycol derivative. Can be manufactured. The oxirane compound represented by the general formula (IV) includes various compounds depending on the types of R ^{1 to} R ⁴ , and specifically, glycidyl methyl ether; ethyl glycidyl ether; propyl glycidyl ether; butyl glycidyl ether; 2-ethylhexyl glycidyl ether; 2-methyloctyl glycidyl ether; vinyl glycidyl ether; allyl glycidyl ether; phenyl glycidyl ether;
Butylphenylglycidyl ether; 4,7-dioxa-1,2-epoxyoctane; 1,2-epoxy-4,
7,10-trioxaundecane; 1,2-epoxy-
4,7,10,13-tetraoxatetradecane;
7-dioxa-1,2-epoxy-5-methyloctane; 4,7-dioxa-1,2-epoxy-6-methyloctane; 6,9-dimethyl-1,2-epoxy-4,
7,10-trioxaundecane; 1,2-epoxy-
4,7,10,13-tetraoxa-6,9,12-trimethyltetradecane; 1,2-epoxy-5-methyl-4,7,10-trioxaundecane; 1,2-epoxy-8-methyl-4 , 7,10-Trioxaundecane; 2,7-dioxa-4,5-epoxyoctane;
4,5-epoxy-9-methyl-2,7,10-trioxaundecane; 4,5-epoxy-2,7,10,1
3-tetraoxatetradecane; 7,8-epoxy-
2,5,10,13-tetraoxatetradecane; 3,
12-dimethyl-7,8-epoxy-2,5,10,1
3-tetraoxatetradecane; 1,2-epoxy-3
-Methoxy-5-oxahexane; 4,8-dioxa-
1,2-epoxy-6-methoxynonane; 4,7-dioxa-1,2-epoxy-5- (2-oxapropyl)
-Octane; 3,5-bis (2-oxapropyl)-
4,7-dioxa-1,2-epoxyoctane; 3,6
-Bis (2-oxapropyl) -4,7-dioxa-
1,2-epoxy-octane; 6,9-bis (2-oxapropyl) -1,2-epoxy-4,7,10-trioxaundecane and the like.

Examples of the polymerization initiator include water, an alkali hydroxide, a mono- to hexavalent alcohol; an alkoxide; a thiol; 2,2'-thiodiethanol; a sodium alkoxide of 2,2'-thiodiethanol, phenol, Known compounds such as phenoxide and amine can be used. Method (Y) At least one of the compounds represented by the general formula (I) obtained by the method (X)
The homopolymer of the oxirane compound represented by V) is polymerized with another oxirane compound represented by the general formula (IV) or an alkylene oxide having 2 to 8 carbon atoms represented by the general formula (V). Thus, a desired polyoxyalkylene glycol derivative can be produced. In this case, two kinds of reactions can be continuously performed in one reactor.

(Z) Method A polyoxyalkylene glycol is obtained by polymerizing an alkylene oxide having 2 to 8 carbon atoms represented by the general formula (V), and then an oxirane compound represented by the general formula (IV) is obtained. Alternatively, the desired polyoxyalkylene glycol derivative can be produced by polymerizing the oxirane compound with the alkylene oxide of the general formula (V). In this case, two kinds of reactions can be performed continuously in one reactor. Such polyoxyalkylene glycol derivatives obtained by the methods (X) to (Z) can improve the solubility, decrease the hygroscopicity, and increase the viscosity by deriving all or a part of the terminal hydroxyl group to an ester or an ether. The performance as a refrigerating machine oil such as an improvement in index and an improvement in lubricity can be further improved. The hydrocarbon group in the ester and ether residues preferably has 1 to 10 carbon atoms.
In the lubricating oil composition for refrigerators I of the present invention, the polyoxyalkylene glycol derivative used as a main component of the base oil has a kinematic viscosity at 40 ° C of 3 to 500 mm ^2.
/ S, preferably 5 to 300 mm ² / s, more preferably 5 to 200 mm ² / s.

Next, the lubricating oil composition II for a refrigerator according to the present invention will be described. Lubricating oil composition II for refrigerators of the present invention,
As a base oil, (a) a kinematic viscosity at 40 ° C. of 3 to 500
(b) a kinematic viscosity at 40 ° C. of 3 to 500 m, based on the mm ² / s polyvinyl ether derivative and the total amount of the base oil;
The polyoxyalkylene glycol derivative having at least one structural unit represented by the above general formula (I) having an m ² / s of 0.1 to less than 60% by weight.

And a chlorine-free refrigerant having 1 carbon atom,
For example, when R32 is contained in the range of 3 to 50% by weight based on the total amount, at any one of the content rates, it is compatible at a temperature of 5 ° C or less (the liquid phase is uniform). . Here, the content of the lubricating oil in which the lubricating oil and the refrigerant can be compatible at a temperature of 5 ° C. or less may be any of the above 3 to 50% by weight, preferably 10% by weight or 15% by weight, Particularly preferably, it is desirable to cover the entire range of 3 to 50% by weight. If the compatibility temperature, that is, the low-temperature two-layer separation temperature exceeds 5 ° C., phase separation may occur during operation of the refrigerator. If phase separation occurs during operation of the refrigerator, the life and efficiency of the device will be significantly adversely affected. For example, if phase separation between refrigeration and lubricating oil occurs in the compressor part, the moving parts will be inadequately lubricated, causing seizure etc., significantly shortening the life of the device, while if phase separation occurs in the evaporator, The presence of the lubricating oil having a high viscosity causes a reduction in the efficiency of heat exchange. For this reason, the maximum temperature of the low-temperature side separation region needs to be 5 ° C. or less, and preferably 3 ° C. or less. The temperature is more preferably 0 ° C or lower, further preferably -2 ° C or lower. Lubricating oil composition for refrigerator of the present invention II
Examples of the polyvinyl ether-based derivative used as the component (a) of the base oil in the general formula (VI)

[0030]

Embedded image

(Wherein, R ¹³ , R ¹⁴ , and R ¹⁵ each represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, which may be the same or different, and R ¹⁶ has 1 carbon atom. ~
10 divalent hydrocarbon groups, R ¹⁷ is a hydrocarbon group having 1 to 20 carbon atoms, a is a number having an average value of 0 to 10, and R ^{13 is}
R ¹⁷ may be the same or different for each structural unit, and when there are a plurality of R ¹⁶ O, a plurality of R ¹⁰ O
O may be the same or different. And the structural unit represented by formula (1). Further, a structural unit represented by the above general formula (VI),
General formula (VII)

[0032]

Embedded image

(Wherein, R ^{18 to} R ²¹ each represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, which may be the same or different, and R ^{18 to} R ^{21 each} have a structure The unit may be the same or different for each unit.) A polyvinyl ether-based compound (2) comprising a block or a random copolymer having a structural unit represented by the formula (2) can also be used.

In the general formula (VI), R ¹³ , R ¹⁴ and R ¹⁵ each represent a hydrogen atom or a hydrocarbon group having 1 to 8, preferably 1 to 4, carbon atoms, which may be the same or different. Is also good. Here, the hydrocarbon group specifically refers to a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group,
cycloalkyl groups such as tert-butyl group, various pentyl groups, various hexyl groups, various heptyl groups, various octyl group alkyl groups, cyclopentyl groups, cyclohexyl groups, various methylcyclohexyl groups, various ethylcyclohexyl groups, various dimethylcyclohexyl groups, Aryl groups of phenyl group, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, benzyl groups, various phenylethyl groups, and arylalkyl groups of various methylbenzyl groups are shown. In addition, as R ¹³ , R ¹⁴ and R ¹⁵ , a hydrogen atom is particularly preferable.

On the other hand, R ¹⁶ in the general formula (VI) has 1 carbon atom.
-10, preferably 2-10 divalent hydrocarbon groups, wherein the divalent hydrocarbon group having 1-10 carbon atoms specifically means a methylene group, an ethylene group, a phenylethylene group, 1,2-propylene group, 2-phenyl-1,2-propylene group, 1,3-propylene group, various butylene groups,
Divalent aliphatic groups such as various pentylene groups, various hexylene groups, various heptylene groups, various octylene groups, various nonylene groups, and various decylene groups, alicyclic carbonization such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, and propylcyclohexane. 2 for hydrogen
Divalent aromatic hydrocarbon groups such as alicyclic groups having various bonding sites, various phenylene groups, various methylphenylene groups, various ethylphenylene groups, various dimethylphenylene groups, various naphthylene groups, toluene, xylene, ethylbenzene, etc. The alkyl group of the alkyl aromatic hydrocarbon and the alkyl group of the polyalkyl aromatic hydrocarbon, such as xylene and diethylbenzene, each having a monovalent binding site on the aromatic portion and the aromatic moiety, and two binding sites on the alkyl group portion of the polyalkyl aromatic hydrocarbon such as xylene and diethylbenzene. Alkyl aromatic groups. Of these, aliphatic groups having 2 to 4 carbon atoms are particularly preferred.

In the general formula (VI), a represents the number of repetitions of R ¹⁶ O, and the average thereof is a number in the range of 0 to 10, preferably 0 to 5. When there are a plurality of R ¹⁶ O,
A plurality of R ¹⁶ Os may be the same or different. further,
R ¹⁷ in the general formula (VI) represents a hydrocarbon group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, and specifically, this hydrocarbon group is a methyl group, an ethyl group, an n-propyl group,
Isopropyl group, n-butyl group, isobutyl group, sec
-Butyl group, tert-butyl group, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl alkyl groups, cyclopentyl groups, cyclohexyl groups, various methylcyclohexyl groups,
Various cycloalkyl groups such as various ethylcyclohexyl groups, various propylcyclohexyl groups, various dimethylcyclohexyl groups, phenyl groups, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butyl groups Aryl groups such as phenyl group and various naphthyl groups, benzyl group, various phenylethyl groups, various methylbenzyl groups,
Examples include various phenylpropyl groups and arylalkyl groups of various phenylbutyl groups.

The R ^{13 to} R ¹⁷ may be the same or different for each structural unit. In the general formula (VII), R ^{18 to} R ²¹ each represent a hydrogen atom or a carbon atom
It represents 0 hydrocarbon radicals, which may be identical or different. Examples of the hydrocarbon group having 1 to 20 carbon atoms may include the same as those exemplified in the description of R ¹⁷ in general formula (VI). R ^{18 to} R ²¹ may be the same or different for each structural unit.

Further, in the present invention, a mixture of the polyvinyl ether compound (I) and the polyvinyl ether compound (2) can also be used. The polyvinyl ether compounds (1) and (2) used in the present invention are obtained by polymerizing the corresponding vinyl ether monomers and copolymerizing the corresponding hydrocarbon monomers having an olefinic double bond with the corresponding vinyl ether monomers. Can be manufactured. As the polyvinyl ether derivative used in the present invention, those having the following terminal structure, that is, one terminal thereof is represented by the general formula (V
III) or (IX)

[0039]

Embedded image

[0040] (wherein, R ^22, R ²³ and R ²⁴ each represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, R ^22,
R ²³ and R ²⁴ may be the same or different,
R ²⁷ , R ²⁸ , R ²⁹ and R ³⁰ each represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R ²⁷ , R ²⁸ , R ²⁹ and R ³⁰ may be the same or different from each other . R ²⁵ is a divalent hydrocarbon group having 1 to 10 carbon atoms, R ²⁶ is 1 to carbon atoms
20 hydrocarbon group, b has an average value thereof indicates the number of 0, when R ²⁵ O is plural, plural R ²⁵ O may be the same or different. ) And the remaining terminal is represented by the general formula (X) or (XI)

[0041]

Embedded image

[0042] (wherein, R ^31, R ³² and R ³³ each represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, R ^31,
R ³² and R ³³ may be the same or different,
R ³⁶ , R ³⁷ , R ³⁸ and R ³⁹ each represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and R ³⁶ , R ³⁷ , R ³⁸ and R ³⁹ may be the same or different from each other . R ³⁴ is a divalent hydrocarbon group having 1 to 10 carbon atoms, R ³⁵ is 1 to carbon atoms
20 hydrocarbon group, c is an average value thereof indicates the number of 0, when R ³⁴ O is plural, plural R ³⁴ O may be the same or different. ), And one end thereof is represented by the above general formula (VIII) or (IX), and the other end is represented by the general formula (XII)

[0043]

Embedded image

(Wherein R ⁴⁰ , R ⁴¹ and R ⁴² each represent a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, which may be the same or different). Those having a structure are preferred. Among such polyvinyl ether compounds, the following compounds are particularly preferred in the present invention. (1) one end of which is represented by the general formula (VIII) or (IX) and the other end has a structure represented by the general formula (X) or (XI); R ¹³ , R ¹⁴ and R ¹⁵
Are both hydrogen atoms, a is a number of 0 to 4, R ¹⁶ is a carbon atom of 2 to 4
And R ¹⁷ is a hydrocarbon group having 1 to 20 carbon atoms. (2) having only the structural unit represented by the general formula (VI), one end of which is represented by the general formula (VIII),
And the remaining terminal has a structure represented by the general formula (X),
In the general formula (VI), R ¹³ , R ¹⁴ and R ¹⁵ are all hydrogen atoms, a is a number of 0 to 4, R ¹⁶ is a divalent hydrocarbon group having 2 to 4 carbon atoms, and R ¹⁷ is a carbon atom of 1 ~ 20 hydrocarbon groups.

(3) One terminal of which is represented by the general formula (VIII) or
 (IX) and the remaining terminal is represented by the general formula (XII)
Having a structure represented by the general formula (VI)¹³, R¹⁴as well as
R^FifteenAre both hydrogen atoms, a is a number from 0 to 4, R¹⁶Has 2 carbon atoms
To 4 divalent hydrocarbon groups and R ¹⁷Is charcoal having 1 to 20 carbon atoms
What is a hydride group. (4) having only the structural unit represented by the general formula (VI)
Wherein one end is represented by the general formula (VIII),
And the other end has a structure represented by the general formula (XI),
R in general formula (VI)¹³, R¹⁴And R^FifteenAre both hydrogen sources
Child, a is a number from 0 to 4, R¹⁶Is a divalent carbon having 2 to 4 carbon atoms
Hydrogen group and R¹⁷Is a hydrocarbon group having 1 to 20 carbon atoms
of. In the present invention, the compound represented by the general formula (VI)
Having one end represented by the general formula (VIII)
And the remaining terminal is represented by the general formula (XIII)

[0046]

Embedded image

(Where R⁴³, R⁴⁴And R⁴⁵Respectively
A hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms,
Each may be the same or different, and R⁴⁶Passing
And R ⁴⁸Represents a divalent hydrocarbon group having 2 to 10 carbon atoms.
And they may be the same or different from each other.
K, R⁴⁷And R⁴⁹Is a hydrocarbon having 1 to 10 carbon atoms, respectively.
Groups which are the same or different
D and e are numbers each having an average value of 0 to 10
And they may be the same or different
Well, multiple R⁴⁶If there is O, multiple R⁴⁶O
May be the same or different, and a plurality of R⁴⁸O
In some cases more than one R⁴⁸O is the same but different
You may. Polyvinyl ether having a structure represented by)
Can also be used. Furthermore, the present invention
In the formula (XIV) or (XV)

[0048]

Embedded image

(Wherein, R ⁵⁰ represents a hydrocarbon group having 1 to 8 carbon atoms), the weight average molecular weight is 300 to 5000, and one terminal is represented by the general formula ( X
VI) or (XVII)

[0050]

Embedded image

(Wherein, R ⁵¹ represents an alkyl group having 1 to 3 carbon atoms, and R ⁵² represents a hydrocarbon group having 1 to 8 carbon atoms). A polyvinyl ether compound composed of a polymer can also be used. The above-mentioned polyvinyl ether derivatives are described in JP-A-6-128578 or Japanese Patent Application Nos. 5-125649 and 5-125650.
And Japanese Patent Application No. 5-303736 can be used. The polyvinyl ether derivative of the component (a)
A kinematic viscosity at 40 ° C. of 3 to 500 mm ² / s,
Preferably 5 to 200 mm ² / s, more preferably 5 to 200 mm ² / s
150 mm ² / s. On the other hand, the component (b) of the base oil has a kinematic viscosity at 40 ° C. of 3 to 500 mm ² / s,
Preferably 5 to 300 mm ² / s, more preferably 5 to 300 mm ² / s
A polyoxyalkylene glycol derivative (used as a main component of the base oil in the lubricating oil composition I) having at least one structural unit represented by the aforementioned general formula (I) and having a diameter of 200 mm ² / s is used.

The lubricating oil composition II for a refrigerator according to the present invention comprises, as a base oil, the above-mentioned polyvinyl ether derivative as the component (a) and the above-mentioned polyoxylated component as the component (b) based on the total amount of the base oil. It contains an alkylene glycol derivative in an amount of 0.1% by weight or more and less than 60% by weight, preferably 0.5% by weight to 55% by weight, more preferably 1.0% by weight to 50% by weight. And other hydrocarbon compounds such as polyesters such as polyoxyalkylene glycols and polyol esters, carbonates, mineral oils, and poly-α-olefins. Refrigeration lubricant composition I, the base oil in the II of the present invention preferably has kinematic viscosity at 40 ° C. is in the range of 7~150mm ² / s, which is in the range of inter alia 8~90mm ² / s Are preferable, and those having a viscosity index of 70 or more are preferable, and those having a viscosity index of 72 to 200, particularly preferably 75 to 180 are preferable. The lubricating oil compositions I and II for refrigerators of the present invention preferably contain an acid scavenger, an extreme pressure agent, an oil agent, and an antioxidant.

Examples of the acid scavenger include glycidyl ether group-containing compounds, epoxidized fatty acid monoesters,
Epoxidized oils and fats, epoxycycloalkyl group-containing compounds, and the like are included. Examples of extreme pressure agents include organic sulfides such as monosulfides, polysulfides, sulfoxides, sulfones, thiosulfinates, sulfurized fats and oils, thiocarbonates, thiophenes, thiazoles, and methanesulfonic acid esters. Compounds, phosphate monoesters, phosphate diesters, phosphate ester such as phosphate triesters (tricresyl phosphate, etc.), phosphite monoesters, phosphite diesters, Phosphorous esters such as phosphite triesters, thiophosphoric esters such as thiophosphoric triesters, higher fatty acids, hydroxyaryl fatty acids, polyhydric alcohol esters, acrylic acid esters, etc. Esters, chlorinated hydrocarbons, chlorinated carboxylic acid derivatives, etc. Chlorine-based, fluorinated aliphatic carboxylic acids, fluorinated ethylene resin, fluorinated alkylpolysiloxanes, organic fluorinated ones such as fluorinated graphite, alcoholic ones such as higher alcohols, naphthenates ( Metal compounds such as lead naphthenate, fatty acid salts (such as lead fatty acid), thiophosphates (such as zinc dialkyldithiophosphate), thiocarbamates, organic molybdenum compounds, organic tin compounds, organic germanium compounds, and borate esters And the like. Further, examples of the antioxidant include phenol-based compounds such as 2,6-di-tert-butyl-p-cresol and amine-based compounds such as α-naphthylamine. Further, as the oil agent, (x) an etherified product of a tri- to hexa-valent aliphatic polyhydric alcohol or (y) a di- or tri-molecular condensate of a tri- to hexa-valent aliphatic poly-alcohol is used. Preferred are mentioned. Next, the (x) component and the (y) component will be described. The etherified product of the tri- to hexa-valent aliphatic polyhydric alcohol of the component (x) is, for example, represented by the following general formula (XVIII-
Those represented by a) to (XVIII-f) are preferred.

[0054]

Embedded image

[Wherein, R ^{53 to} R ⁵⁸ each represent a hydrogen atom or a linear or branched alkyl group, aryl group or aralkyl group having 1 to 18 carbon atoms, which may be the same or different. . Further,-(R ^a O) _x -R ^b (R ^a
Is an alkylene group having 2 to 6 carbon atoms, and ^Rb is 1 to 20 carbon atoms.
An alkyl group, an aryl group or an aralkyl group, wherein x is 1 to
Indicates an integer of 10. ) Represents a glycol ether residue. ]. Specific examples of the tri- to hexa-valent aliphatic polyhydric alcohols include glycerin, trimethylolpropane, erythritol, pentaerythritol, arabitol,
Sorbitol, mannitol and the like can be mentioned. In the above general formulas (XVIII-a) to (XVIII-f),
R ^{53 to} R ⁵⁸ are, for example, methyl group, ethyl group, n-propyl group, isopropyl group, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups, Various undecyl groups,
Examples include various dodecyl groups, various tridecyl groups, various tetradecyl groups, various pentadecyl groups, various hexadecyl groups, various heptadecyl groups, various octadecyl groups, phenyl groups, and benzyl groups. Further, the case of a hydrogen atom, that is, a partially etherified product is also included. (Y) Component 3
Regarding the etherified product of a bimolecular condensate or a trimolecular condensate of an aliphatic polyhydric alcohol having 6 to 6 valences, for example, the etherified product of the alcohol corresponding to the general formula (XVIII-a) is represented by the general formula (XVIII-g). (XVIII-h) represented by the general formula (X
The etherified product of the alcohol corresponding to VIII-d) is represented by the general formulas (XVIII-i) and (XVIII-j).

[0056]

Embedded image

(In the formula, R ^{53 to} R ⁶⁰ are the same as R ^{53 to} R ⁵⁸ , and they may be the same or different.) Bimolecular condensate of tri to hexavalent aliphatic polyhydric alcohol Specific examples of the trimolecular condensate include diglycerin, ditrimethylolpropane, dipentaerythritol, disorbitol, triglycerin, tritrimethylolpropane,
Tripentaerythritol, trisorbitol and the like can be mentioned.

Specific examples of the components (x) and (y) represented by the general formulas (XVIII-a) to (XVIII-j) include trihexyl ether of glycerin, dimethyloctyl triether of glycerin, and glycerin of glycerin. Di (methyloxyisopropylene) dodecyl triether, diphenyloctyl triether of glycerin, di (phenyloxyisopropylene) dodecyl triether of glycerin, trihexyl ether of trimethylolpropane, dimethyloctyl triether of trimethylolpropane, trimethylol Propane di (methyloxyisopropylene) dodecyl triether, pentaerythritol tetrahexyl ether, pentaerythritol trimethyloctyltetraether, pentaerythritol tri (methyloxyyl) Propylene) dodecyltetraether, sorbitol hexapropylether, sorbitol tetramethyloctylpentaether, sorbitol hexa (methyloxyisopropylene) ether, diglycerin tetrabutylether, diglycerin dimethyldioctyltetraether, diglycerin tri ( Methyloxyisopropylene) dodecyltetraether, pentaethylether of triglycerin,
Triglycerin trimethyldioctyl pentaether, triglycerin tetra (methyloxyisopropylene) decyl pentaether, ditrimethylolpropane tetrabutylether, ditrimethylolpropane dimethyldioctyltetraether, ditrimethylolpropane tri (methyloxyisopropylene) dodecyl Tetraether, pentaethyl ether of tritrimethylolpropane, trimethyldioctyl pentaether of tritrimethylolpropane, tetra (methyloxyisopropylene) decyl pentaether of tritrimethylolpropane, hexapropylether of dipentaerythritol, pentamethyloctyl of dipentaerythritol Hexaether, dipentaerythritol hexa (methyl (Ciisopropylene) ether, octapropyl ether of tripentaerythritol, pentamethyloctyl hexaether of tripentaerythritol, hexa (methyloxyisopropylene) ether of tripentaerythritol, octamethyldioctyl decaether of disorbitol, deca of disorbitol (Methyloxyisopropylene) ether and the like. Among them, diphenyloctyl triether of glycerin, di (methyloxyisopropylene) dodecyl triether of trimethylolpropane, tetrahexyl ether of pentaerythritol, hexapropyl ether of sorbitol, dimethyldioctyl tetraether of diglycerin, and dimethyldioctyl tetraether of triglycerin Tetra (methyloxyisopropylene) decyl pentaether, hexapropyl ether of pentaerythritol, and pentamethyloctyl hexaether of tripentaerythritol are preferred.

The kinematic viscosity of the components (x) and (y) at 40 ° C. is 5 to 200 mm ² / s, preferably 10 to 200 mm ² / s.
It is in the range of 100 mm ² / s. If it is less than 5 mm ² / s, the effect of improving lubricity and the effect of preventing capillary clogging are small, and if it exceeds 200 mm ² / s, the compatibility with the refrigerant (two-layer separation temperature) is undesirably reduced. In the lubricating oil compositions I and II for refrigerators of the present invention, one of the above components (x) and (y) may be used alone, or two or more may be used in combination. Further, the amount is preferably in the range of 0.1 to 30% by weight based on the total amount of the composition. When the amount is less than 0.1% by weight, the object of the present invention is not sufficiently exhibited. When the amount exceeds 30% by weight, the effect is not improved for the amount, and the solubility in the base oil decreases. May be. A more preferred compounding amount is 0.1 to 1
It is in the range of 5% by weight, particularly preferably in the range of 0.5 to 10% by weight.

The lubricating oil compositions I and II of the present invention may contain other additives conventionally used in lubricating oils, such as metal deactivators, defoamers, detergent / dispersants, and viscosity index improvers. Agents, oily agents, anti-wear additives, rust inhibitors, corrosion inhibitors, pour point depressants, and the like can be included as desired.
Benzotriazole derivatives and the like as metal deactivators, silicone oil (dimethylpolysiloxane and the like), polymethacrylates and the like as defoamers and the like,
Detergents include sulfonates, phenates, succinimides, and the like, and viscosity index improvers include polymethacrylate, polyisobutylene, ethylene-propylene copolymers, styrene-diene hydrogenated copolymers, and the like. .

Next, the working fluid composition for a refrigerator according to the present invention comprises:
It contains (A) a refrigerant having 1 carbon atom and no chlorine, and (B) the lubricating oil composition I or II for a refrigerator according to the present invention described above. Difluoromethane (R32) can be cited as an example of the chlorine-free refrigerant having no component (A) and having 1 carbon atom. The content ratio of the component (A) to the component (B) is usually 5:95 to 99: 1, preferably 1 to 1 by weight.
It is selected in the range of 0:90 to 99: 1. If the amount of the refrigerant is less than the above range, the refrigeration capacity is reduced,
On the other hand, if it is more than the above range, the lubricating performance is undesirably reduced. The lubricating oil compositions I and II for refrigerators of the present invention can be used for various refrigerators, but are particularly preferably applied to a compression refrigeration cycle of a compression refrigerator. For example, JP-A-4-183788, JP-A-8-259975, JP-A-8-240362, JP-A-8-253779, JP-A-8-240352, JP-A-5-17792, and JP-A-8-226717. Gazette and Id.
For example, the lubricating oil compositions I and II for a refrigerator according to the present invention are suitable for use in a refrigerating apparatus disclosed in Japanese Patent No. 72-72 or the like. Even when applied to a compression refrigeration cycle having a hot gas line, the effect is effectively exerted.

FIG. 1 is a flowchart showing an example of a compression refrigeration cycle of “compressor-condenser-expansion valve-evaporator” having an oil separator and a hot gas line, and FIG. FIG. 3 is a flowchart showing an example of a compression-type refrigeration cycle of “compressor-condenser-expansion valve-evaporator” having a hot gas line. It is a flowchart which shows an example of a type refrigeration cycle.
Reference numeral 1 denotes a compressor, 2 denotes a condenser, 3 denotes an expansion valve, 4 denotes an evaporator, 5 denotes an oil separator, 6 denotes a hot gas line, and 7 denotes a hot gas line valve. Usually, the compression refrigeration cycle
It consists of a compressor-condenser-expansion valve-evaporator as shown in FIG. Generally, lubricating oil for refrigerators having good compatibility with the refrigerant used for refrigerators is used. However, when a refrigerant mainly containing the component (A) is used in the above refrigeration cycle, if the refrigerator is lubricated with a commonly used refrigerating machine oil, abrasion resistance is insufficient or stability is insufficient. As a result, long-term stable use was not possible. In particular, this tendency is remarkable when a capillary tube is used as an expansion valve as in a refrigeration cycle of an electric refrigerator or a small air conditioner. The lubricating oil compositions I and II for refrigerators of the present invention can be used even when a compression refrigeration cycle having an oil separator and / or a hot gas line is operated using a refrigerant containing the component (A) as a main component. It is effective as a lubricating oil composition for refrigerators.

In the working fluid composition for a refrigerator according to the present invention, the components (A) and (B) are extremely compatible with each other, and particularly, the maximum temperature of the low temperature side separation region is 5 ° C. or less, Preferably 3 ° C. or less, more preferably 0 ° C. or less,
More preferably, the temperature is -2 ° C or less. Since the working fluid composition for a refrigerator according to the present invention has a maximum temperature of 10 ° C. or less in the separation region on the low temperature side, phase separation does not occur on the low temperature side during operation of the refrigerator. Enables stable operation of

[0064]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The kinematic viscosity and viscosity index of the base oil and various properties of the lubricating oil were determined according to the following procedures. <Base oil> (1) Kinematic viscosity Kinematic viscosity was measured at a temperature of 40 ° C and 100 ° C using a glass capillary viscometer according to JIS K2283-1983. <Lubricating oil> (2) Kinematic viscosity Kinematic viscosity at a temperature of 40 ° C was measured using a glass capillary viscometer according to JIS K2283-1983.

(3) Compatibility test A predetermined amount of a sample was added to a pressure-resistant glass ampule, and this was connected to a vacuum pipe and a difluoromethane (R32) refrigerant pipe. After the ampoule was degassed under vacuum at room temperature, it was cooled to collect a predetermined amount of difluoromethane (R32) refrigerant. Next, the ampoule is sealed, and in a thermostat, for compatibility on the low temperature side,
By gradually cooling from room temperature to −50 ° C., the temperature at which phase separation started was measured. On the low temperature side, the lower the phase separation temperature, the better. (4) Lubricity ASTM, D-323 with closed Falex friction tester
Seizure load was determined according to the three methods. The test conditions were
The oil amount was 300 ml, the refrigerant R32, the pressure was 0.8 MPaG, and the temperature was 50 ° C. (5) Stability (Shield tube test) Lubricant sample 4 was placed in an autoclave with an internal volume of 200 ml.
0 g, R32 refrigerant gas 40 g and metal catalysts of copper, aluminum and iron were added, and water was added so that the water content in the system became 2000 ppm. Seal the autoclave and 175
After holding at 21 ° C. for 21 days, the lubricating oil samples were analyzed.

Production Example A polyoxyalkylene glycol derivative MIPPO was prepared with reference to the method described in JP-B-7-119430.
-1 and MIPPO-2 were produced. MIPPO-1: Poly [methoxyisopropoxypropylene oxide] (both terminal methyl groups) MIPPO-2: Poly [methoxyisopropoxypropylene oxide / ethylene oxide] copolymer (both terminal methyl groups) Kinematic viscosity and viscosity index of MIPPO-2 and PIP-1: PVE-2 and PV
This is shown together with the data of E-3.

[0067]

[Table 1]

(Note) MIPPO-1: Poly [methoxyisopropoxypropylene oxide] (both terminal methyl groups) MIPPO-2: Poly [methoxyisopropoxypropylene oxide / ethylene oxide] copolymer (both terminal methyl groups) PVE- 1: Poly [ethyl vinyl ether / isobutyl vinyl ether (molar ratio 9/1)] copolymer PVE-2: Poly [ethyl vinyl ether / isobutyl vinyl ether (molar ratio 8/2)] copolymer PVE-3: polyethyl vinyl ether Examples 1 to 7 A base oil (a) and a base oil (b) of the type shown in Table 2 were mixed in the proportions shown in the table to prepare a lubricating oil, and its properties were determined. The results are shown in Table 2. Comparative Examples 1 to 3 Various properties of lubricating oils composed of polyvinyl ether alone of the type shown in Table 2 were determined. The results are shown in Table 2.

[0069]

[Table 2]

[0070]

[Table 3]

(Note) 1) The weight% at the critical dissolution temperature is [sample / (sample +
R32)] × 100.

[0072]

The lubricating oil composition for refrigerators of the present invention contains, as a base oil, a polyoxyalkylene glycol derivative having a specific structure as a main component, or a polyvinyl ether derivative and the above polyoxyalkylene glycol derivative. And exhibits excellent compatibility with chlorine-free refrigerants having 1 carbon atom, particularly difluoromethane. The lubricating oil composition for a refrigerator and the working fluid composition for a refrigerator of the present invention containing the refrigerant are excellent in abrasion resistance, lubrication characteristics, stability and the like.

[Brief description of the drawings]

FIG. 1 is a flowchart showing an example of a compression-type refrigeration cycle of “compressor-condenser-expansion valve-evaporator” having an oil separator and a hot gas line.

FIG. 2 is a flowchart showing an example of a compression refrigeration cycle of a “compressor-condenser-expansion valve-evaporator” having an oil separator.

FIG. 3 is a flowchart showing an example of a compression refrigeration cycle of a “compressor-condenser-expansion valve-evaporator” having a hot gas line.

FIG. 4 is a flowchart showing an example of a compression refrigeration cycle of “compressor-condenser-expansion valve-evaporator”.

[Explanation of symbols]

 1: Compressor 2: Condenser 3: Expansion valve 4: Evaporator 5: Oil separator 6: Hot gas line 7: Valve for hot gas line

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C10N 30:00 C10N 30:00 Z 30:06 30:06 30:10 30:10 40:30 40:30

Claims (8)

[Claims] 1. A base oil of the general formula (I) [Wherein, R ^{1 to} R ⁴ each independently represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 10 carbon atoms, or a compound represented by the general formula (II): (R ⁵ and R ⁶ each independently represent a hydrogen atom,
A monovalent hydrocarbon group or an alkoxyalkyl group having 2 to 20 carbon atoms, R ⁷ is an alkylene group having 2 to 5 carbon atoms, a substituted alkylene group having 2 to 5 carbon atoms or a substituted alkylene group having an alkyl group as a substituent; A substituted alkylene group having a total of 4 to 10 carbon atoms having an alkyl group as a substituent, R ⁸ is a monovalent hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 0 to 20. ), Wherein at least one of R ^{1 to} R ⁴ is a group represented by the general formula (II). A polyoxyalkylene glycol derivative having at least one structural unit represented by the formula:
What is claimed is: 1. A lubricating oil composition for a refrigerator using a refrigerant having 1 carbon atom and having no chlorine, wherein the lubricating oil composition contains, as a main component, one having a diameter of 00 mm ² / s. 2. As a base oil, (a) kinematic viscosity at 40 ° C.
Degree is 3-500mm ^Two/ S polyvinyl ether derivative
(B) Kinematic viscosity at 40 ° C based on body and total amount of base oil
Is 3 ~ 500mm^Two/ S represented by the general formula (I)
Polyoxyalkylene having at least one structural unit
Contains 0.1% to less than 60% by weight of glycol derivatives
The number of carbon atoms in a lubricating oil composition for refrigerators that does not contain chlorine
3 to 50% by weight based on the total amount for one refrigerant
If contained in any of the
The two-layer separation temperature on the warm side is 5 ° C or less.
Lubricating oil composition for refrigerators. 3. A base oil having a kinematic viscosity at 40 ° C. of 7-15.
3. The lubricating oil composition for a refrigerator according to claim 1, which has a viscosity of 0 mm ² / s and a viscosity index of 70 or more. 4. The lubricating oil composition for a refrigerator according to claim 1, further comprising an acid scavenger. 5. The lubricating oil composition for a refrigerator according to claim 1, further comprising at least one additive selected from an extreme pressure agent, an oil agent and an antioxidant. 6. A refrigerant having no chlorine and having 1 carbon atom,
And (B) a working fluid composition for a refrigerator, comprising the lubricating oil composition for a refrigerator according to any one of claims 1 to 5. 7. The working fluid composition for a refrigerator according to claim 6, comprising the component (A) and the component (B) in a weight ratio of 5:95 to 99: 1. 8. The working fluid composition for a refrigerator according to claim 6, wherein the refrigerant of the component (A) is difluoromethane.