JP6849746B2 - Refrigerating machine lubricating oil and mixed composition for refrigerating machine - Google Patents

Description

The present invention relates to a refrigerating machine lubricating oil used by mixing with various refrigerants and a mixed composition of the refrigerating machine lubricating oil and the refrigerant, and is particularly used for car air conditioners such as open type car air conditioners and electric car air conditioners. Regarding refrigerating machine lubricating oil and mixed composition.

Generally, a refrigerator is composed of at least a compressor, a condenser, an expansion mechanism (expansion valve, etc.), an evaporator, or a dryer, and a mixture of a refrigerant and a refrigerator lubricant (refrigerator oil) is contained in this sealed system. It has a structure that circulates inside. Chlorofluorocarbons and other chlorine-containing compounds have been widely used as refrigerants for refrigerators, but from the viewpoint of environmental protection, in recent years, chlorine-free compounds such as hydrofluorocarbons (HFCs) and natural compounds such as carbon dioxide have been used. It has been replaced by a refrigerant. Examples of hydrofluorocarbons include 1,1,1,2-tetrafluoroethane, difluoromethane, pentafluoroethane, and 1,1,1-trifluoroethane (hereinafter referred to as R134a, R32, R125, and R143a, respectively). Saturated hydrofluorocarbons represented by (hereinafter, also referred to as saturated HFCs) have been put into practical use.

However, as a refrigerant for car air conditioners, it is currently difficult to use carbon dioxide as a main component, which requires high pressure, and saturated HFC also has a problem that it has a high global warming potential. Therefore, in recent years, the use of unsaturated fluorinated hydrocarbon refrigerants such as HFO1234ze and HFO1234yf has been studied as a refrigerant that can be used in a car air-conditioning system even though the global warming potential is low.
For unsaturated fluorinated hydrocarbon refrigerants, the use of oxygen-containing compounds such as polyoxyalkylene glycols, polyol esters, and polycarbonates as the base oil for refrigerating machine oil has been studied.

As the polyol ester-based refrigerating machine oil used for the unsaturated fluorinated hydrocarbon refrigerant, it is known that an ester of pentaerythritol or dipentaerythritol is used as a base oil. Specifically, a polyol ester composed of pentaerythritol or dipentaerythritol and a mixture of a fatty acid having 8 carbon atoms and a fatty acid having 9 carbon atoms, or a polyol ester composed of pentaerythritol or dipentaerythritol and a fatty acid having 5 to 7 carbon atoms. , Pentaerythritol or dipentaerythritol, and polyol esters composed of fatty acids having 14 to 22 carbon atoms are known (see Patent Documents 1 to 4).

Japanese Unexamined Patent Publication No. 2008-115266 JP-A-2009-74017 JP-A-2009-74021 Japanese Unexamined Patent Publication No. 2011-190319

However, the conventional polyol ester-based refrigerating machine oil may swell various rubber members used in the refrigerating machine, causing refrigerant leakage and lubricating oil leakage. In addition, some polyol ester-based refrigerating machine oils do not have sufficient compatibility with unsaturated fluorinated hydrocarbon refrigerants. That is, it has been difficult to appropriately suppress the swelling of various rubber members while improving the compatibility with the unsaturated fluorinated hydrocarbon refrigerant with the conventional polyol ester-based refrigerating machine oil.

The present invention has been made in view of the above problems, and it is appropriate to swell the rubber member used in the refrigerator without impairing the compatibility between the unsaturated hydrocarbon refrigerant and the lubricating oil of the refrigerator. It is an object of the present invention to provide a chiller lubricating oil that can be suppressed, and a mixed composition for a chiller composed of the chiller lubricating oil and an unsaturated fluorinated hydrocarbon refrigerant.

As a result of diligent studies, the present inventors have found that a polyol ester-based refrigerating machine oil having a specific structure can appropriately suppress rubber swelling without impairing compatibility with an unsaturated fluorinated hydrocarbon refrigerant. Completed the invention. That is, the present invention provides the following (1) to (15).
(1) The following molecular formula (1)
_Cp F _r H _s ... (1)
[In the formula, p is an integer of 2 to 6, r is an integer of 1 to 11, and s is an integer of 1 to 11, and has one or more carbon-carbon unsaturated bonds in the molecule. ]
A refrigerant containing at least one unsaturated fluorinated hydrocarbon compound selected from the compounds represented by
A fatty acid (a1) having 9 to 16 carbon atoms and having 9 carbon atoms in an amount of 50 mol% or more based on the total amount of the fatty acid (a1), and a polyol (a2) which is pentaerythritol and / or dipentaerythritol. A mixed composition for a refrigerator containing a refrigerating machine lubricating oil containing the polyol ester (A) as a main component.
(2) The mixed composition for a refrigerator according to (1) above, wherein the unsaturated fluorinated hydrocarbon compound is a fluoride of propene.
(3) The fluoride of the propene is various isomers of pentafluoropropene, 3,3,3-trifluoropropene, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetra. The mixed composition for a refrigerator according to (2) above, which is at least one selected from fluoropropene.
(4) The mixed composition for a refrigerator according to any one of (1) to (3) above, wherein the refrigerant comprises only the unsaturated fluorinated hydrocarbon compound.
(5) The mixed composition for a refrigerator according to any one of (1) to (4) above, wherein the fatty acid (a1) is composed of only a fatty acid having 9 carbon atoms.
(6) The fatty acid (a1) has 9 carbon atoms in an amount of 50 mol% or more based on the total amount of the fatty acid (a1), and the balance is a fatty acid having 10 to 12 carbon atoms. The mixed composition for a refrigerator according to any one of (4).
(7) The mixed composition for a refrigerator according to any one of (1) to (6) above, wherein the fatty acid having 9 to 16 carbon atoms contains a branched fatty acid.
(8) Hydrogenated nitrile rubber (H-NBR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene / propylene / diene ternary copolymer (EPDM), silicone rubber, butyl rubber (IIR), styrene butadiene rubber (SBR), Urethane Rubber (U), Chlorosulfonated Polyethylene (CSM), and Fluoro Rubber (FKM). ). The mixed composition for a refrigerator.
(9) Any of the above (1) to (8), wherein the refrigerator lubricating oil contains at least one additive selected from an extreme pressure agent, an oily agent, an antioxidant, an acid scavenger and an antifoaming agent. The mixed composition for a refrigerator described in Crab.
(10) The refrigerant further contains a saturated fluorinated hydrocarbon compound, and the saturated fluorinated hydrocarbon compound is at least one selected from 1,1-difluoroethane, trifluoroethane, tetrafluoroethane and pentafluoroethane. The mixed composition for a refrigerator according to any one of (1) to (3) and (5) to (9) above.
(11) The above (1) to (10) used in a refrigerator system, a hot water supply system, or a heating system selected from car air conditioners, gas heat pumps, air conditioners, refrigerators, vending machines, showcases, water heaters, and floor heating. The mixed composition for a refrigerator according to any one of.
(12) The mixed composition for a refrigerator according to (11) above, wherein the water content in the system is 300 mass ppm or less and the residual air partial pressure is 10 kPa or less.
(13) The following molecular formula (1)
_Cp F _r H _s ... (1)
[In the formula, p is an integer of 2 to 6, r is an integer of 1 to 11, and s is an integer of 1 to 11, and has one or more carbon-carbon unsaturated bonds in the molecule. ]
A refrigerating machine lubricating oil used as a refrigerant containing at least one unsaturated fluorinated hydrocarbon compound selected from the compounds represented by.
A fatty acid (a1) having 9 to 16 carbon atoms and having 9 carbon atoms in an amount of 50 mol% or more based on the total amount of the fatty acid (a1), and a polyol (a2) which is pentaerythritol and / or dipentaerythritol. Refrigerator lubricating oil containing the above-mentioned polyol ester (A) as a main component.
(14) The following molecular formula (1)
_Cp F _r H _s ... (1)
[In the formula, p is an integer of 2 to 6, r is an integer of 1 to 11, and s is an integer of 1 to 11, and has one or more carbon-carbon unsaturated bonds in the molecule. ]
In a refrigerator using a refrigerant containing at least one unsaturated fluorinated hydrocarbon compound as a main component selected from the compounds represented by
A fatty acid (a1) having 9 to 16 carbon atoms and having 9 carbon atoms in an amount of 50 mol% or more based on the total amount of the fatty acid (a1), and a polyol (a2) which is pentaerythritol and / or dipentaerythritol. A lubrication method using a refrigerator lubricating oil containing the above-mentioned polyol ester (A) as a main component.
(15) The following molecular formula (1)
_Cp F _r H _s ... (1)
[In the formula, p is an integer of 2 to 6, r is an integer of 1 to 11, and s is an integer of 1 to 11, and has one or more carbon-carbon unsaturated bonds in the molecule. ]
A refrigerant containing at least one unsaturated fluorinated hydrocarbon compound selected from the compounds represented by
A fatty acid (a1) having 9 to 16 carbon atoms and having 9 carbon atoms in an amount of 50 mol% or more based on the total amount of the fatty acid (a1), and a polyol (a2) which is pentaerythritol and / or dipentaerythritol. Refrigerator equipped with a refrigerating machine lubricating oil containing the above-mentioned polyol ester (A) as a main component.

According to the present invention, rubber swelling due to the chiller lubricating oil or the chiller mixed composition can be appropriately suppressed without impairing the compatibility between the unsaturated fluorinated hydrocarbon refrigerant and the chiller lubricating oil.

Hereinafter, preferred embodiments of the present invention will be described in detail.
The refrigerating machine lubricating oil according to the present invention is used for the following refrigerants. Further, the mixed composition for a refrigerator according to the present invention contains a refrigerating machine lubricating oil and a refrigerant. Hereinafter, the refrigerant and the lubricating oil for the refrigerator will be described in more detail.
<Refrigerant>
The refrigerant according to the present invention has the following molecular formula (1).
_Cp F _r H _s ... (1)
[In the formula, p is an integer of 2 to 6, r is an integer of 1 to 11, and s is an integer of 1 to 11, and has one or more carbon-carbon unsaturated bonds in the molecule. ]
It contains at least one unsaturated fluorinated hydrocarbon compound selected from the compounds represented by (1) as a main component.

The molecular formula (1) represents the type and number of elements in the molecule, and the formula (1) represents an unsaturated fluorinated hydrocarbon compound in which the number p of carbon atoms C is 2 to 6. An unsaturated fluorinated hydrocarbon compound having 2 to 6 carbon atoms can have physical and chemical properties such as boiling point, freezing point, and latent heat of vaporization required as a refrigerant.
In the molecular formula (1), _{the bond form of p carbon atoms represented by C p} includes an unsaturated bond such as a carbon-carbon single bond and a carbon-carbon double bond. The carbon-carbon unsaturated bond is preferably a carbon-carbon double bond from the viewpoint of stability, and the unsaturated fluorinated hydrocarbon compound is an unsaturated bond such as a carbon-carbon double bond in the molecule. It is preferable that the number is 1 or more and the number is 1. That is, it is more preferable that at least one of the bond forms of p carbon atoms represented by _{C p is a carbon-carbon double bond.}

Preferred examples of the unsaturated fluorinated hydrocarbon compound include fluorides of linear or branched chain olefins having 2 to 6 carbon atoms and cyclic olefins having 4 to 6 carbon atoms.
Specifically, the fluoride of ethylene having 1 to 3 fluorine atoms introduced, the fluoride of propene having 1 to 5 fluorine atoms introduced, and the butene having 1 to 7 fluorine atoms introduced. Fluoride, pentene fluoride with 1-9 fluorine atoms introduced, hexene fluoride with 1-11 fluorine atoms introduced, cyclobutene fluoride with 1-5 fluorine atoms introduced , Cyclopentene fluoride into which 1 to 7 fluorine atoms have been introduced, cyclohexene fluoride into which 1 to 9 fluorine atoms have been introduced, and the like.

Among these unsaturated fluoride hydrocarbon compounds, fluoride of propene is preferable, propene having 3 to 5 fluorine atoms introduced is more preferable, and specifically, various isomers of pentafluoropropene, 3, Preferred specific examples include 3,3-trifluoropropene, 1,3,3,3-tetrafluoropropene represented by HFO1234ze, and 2,3,3,3-tetrafluoropropene represented by HFO1234yf.
Among these, propene having four fluorine atoms introduced is more preferable, and 2,3,3,3-tetrafluoropropene represented by HFO1234yf is particularly preferable.
In the present invention, this unsaturated fluorinated hydrocarbon compound may be used alone or in combination of two or more.

[Other ingredients]
In the present invention, the refrigerant may be a mixed refrigerant containing, if necessary, other compounds in addition to the unsaturated fluorinated hydrocarbon compound, and may include, for example, a saturated fluorinated hydrocarbon compound.
As the saturated fluorinated hydrocarbon compound, a fluoride of alkane having 2 to 4 carbon atoms is preferable, and 1,1-difluoroethane (R152a), 1,1,1-trifluoroethane (R143a), which are fluorides of ethane, are used. Trifluoroethane such as 1,1,2-trifluoroethane (R143), tefura such as 1,1,1,2-tetrafluoroethane (R134a), 1,1,2,2-tetrafluoroethane (R134) Examples thereof include pentafluoroethanes such as fluoroethane and 1,1,1,2,2-pentafluoroethane (R125). These saturated fluorinated hydrocarbon compounds may be used alone or in combination of two or more.

Further, the refrigerant may contain carbon dioxide, in which case the refrigerant preferably contains an unsaturated fluorinated hydrocarbon compound, carbon dioxide, and another third component. Specifically, 1,3,3,3-tetrafluoropropene (HFO1234ze), carbon dioxide (R744), difluoromethane (R32), 1,1-difluoroethane (R152a), fluoroethane (R161), 1 , 1,1,2-Tetrafluoroethane (R134a), propylene, propane and a third component selected from mixtures thereof are preferably included.

Further, the fact that the refrigerant contains an unsaturated fluorinated hydrocarbon compound represented by the molecular formula (1) as a main component means that the refrigerant contains 50% by mass or more based on the total amount of the refrigerant, and the content thereof is based on the total amount of the refrigerant. It is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, but it is preferable that other components such as a saturated fluorinated hydrocarbon compound are not blended, and the refrigerant is unsaturated foot. It is better to consist only of the hydrocarbon compound.

<Refrigerator lubricant>
The refrigerating machine lubricating oil of the present invention contains a polyol ester (A) as a main component. Hereinafter, the polyol ester (A) will be described in more detail.

[Polyform ester (A)]
The polyol ester (A) is a fatty acid having 9 to 16 carbon atoms, and the fatty acid having 9 carbon atoms is 50 mol% or more based on the total amount of the fatty acid (a1), and pentaerythritol and / or dipenta. It is a polyol ester with a polyol (a2) which is erythritol. More specifically, in the polyol ester (A), the fatty acid (a1) is composed of only the fatty acid having 9 carbon atoms, or the fatty acid having 9 carbon atoms is 50 mol% based on the total amount of the fatty acid (a1). In addition to the above, the balance is a fatty acid having 10 to 16 carbon atoms.
By using the above-mentioned polyol ester (A) in the chiller lubricating oil, the compatibility with the refrigerant containing an unsaturated fluorinated hydrocarbon compound as a main component becomes good, and rubber swelling can be easily suppressed. Further, from the viewpoint of further improving the compatibility, the fatty acid (a1) is preferably composed only of the fatty acid having 9 carbon atoms, and in order to improve the compatibility and the effect of suppressing rubber swelling in a well-balanced manner, the fatty acid (a1) has 10 to 16 carbon atoms. It is preferable to contain the fatty acid of.

In the fatty acid (a1), examples of the fatty acid having 9 carbon atoms include linear fatty acids such as n-nonanoic acid and branched fatty acids such as branched nonane acid. Among these, branched fatty acids are preferable from the viewpoint of appropriately suppressing rubber swelling while improving compatibility with unsaturated fluorinated hydrocarbon compounds, and among the branched fatty acids, 3,5,5-trimethylhexane Acids are more preferred.
The fatty acids having 10 to 16 carbon atoms in the fatty acid (a1) include n-decanoic acid, n-undecanoic acid, lauric acid (n-dodecanoic acid), n-tridecanoic acid, and myristic acid (n-tetradecanoic acid). Linear fatty acids such as n-pentadecanoic acid and palmitic acid (n-hexadecanoic acid); branched decanoic acid typified by neodecanoic acid, branched undecanoic acid, branched decanoic acid typified by 2-butyloctanoic acid and the like. Examples thereof include branched fatty acids such as branched hexadecanoic acid represented by dodecanoic acid, branched tridecanoic acid, branched tetradecanoic acid, branched pentadecanoic acid, and isopalmitic acid.
As the fatty acid having 10 to 16 carbon atoms, a branched fatty acid is preferable from the viewpoint of appropriately improving the above-mentioned compatibility and the effect of suppressing rubber swelling. Of these, neodecanoic acid is more preferable from the viewpoint of more easily exerting the above-mentioned compatibility and the effect of suppressing rubber swelling. Further, 2-butyloctanoic acid, isopalmitic acid and the like are more preferable, and 2-butyloctanoic acid is further preferable among these, from the viewpoint of being able to improve the viscosity characteristics in addition to the compatibility and the effect of suppressing rubber swelling. ..

As described above, the fatty acid (a1), that is, the fatty acid having 9 carbon atoms and / or the fatty acid having 10 to 16 carbon atoms is preferably contained, but is contained in, for example, the fatty acid (a1). The 9-carbon fatty acid contains, preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more of branched fatty acids, but all of them are branched fatty acids. Is particularly preferable. Similarly, the fatty acid having 10 to 16 carbon atoms contained in the fatty acid (a1) is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 90, out of the total amount of fatty acids having 10 to 16 carbon atoms. It contains mol% or more of branched fatty acids, but it is particularly preferable that all of them are branched fatty acids.

When the fatty acid (a1) has 9 carbon atoms in an amount of 50 mol% or more based on the total amount of the fatty acid (a1) and the balance is composed of a fatty acid having 10 to 16 carbon atoms. The fatty acid having 9 carbon atoms is preferably 60 mol% or more with respect to the total amount of the fatty acid (a1) from the viewpoint that the compatibility and the effect of suppressing rubber swelling can be improved in a well-balanced manner while improving the viscosity characteristics.
When the fatty acid (a1) contains a fatty acid having 13 to 16 carbon atoms, the fatty acid having 13 to 16 carbon atoms is preferably 30 mol% or less, preferably 1 to 25 mol% or less, based on the total amount of the fatty acid (a1). Is more preferable. As described above, when a fatty acid having a relatively large number of carbon atoms is used, by suppressing the amount of the fatty acid used, it becomes easy to improve the compatibility as described above while appropriately suppressing the rubber swelling.
Further, when the fatty acid (a1) contains a fatty acid having 10 to 12 carbon atoms, the fatty acid having 10 to 12 carbon atoms may be 50 mol% or less based on the total amount of the fatty acid (a1), but 10 to 40 mol%. It is preferably about.
Further, as the fatty acid (a1), it is preferable that the fatty acid having 9 carbon atoms is 50 mol% or more based on the total amount of the fatty acid (a1), and the remaining amount is a fatty acid having 10 to 12 carbon atoms. As described above, when the fatty acid having 10 to 16 carbon atoms contained in the fatty acid (a1) has a relatively small carbon number, the compatibility and the effect of suppressing rubber swelling can be improved in a well-balanced manner.

The polyol ester (A) may be an ester in which pentaerythritol or dipentaerythritol is used alone as the polyol (a2), or may be a mixture of esters of these two types of polyols, but is compatible with each other. From the viewpoint of improving the above, it is preferable to contain pentaerythritol, and it is more preferable to use pentaerythritol alone. Further, from the viewpoint of appropriately suppressing rubber swelling, the polyol ester (A) preferably contains an ester of dipentaerythritol.
In the case of a mixture of the esters of the above two types of polyols, the ester of pentaerythritol is preferably more than the ester of dipentaerythritol on a molar basis, and the molar ratio of the ester of pentaerythritol to the ester of dipentaerythritol (penta). Estererythritol / dipentaerythritol) is more preferably 95/5 to 60/40.

When the fatty acid (a1) has 9 carbon atoms in an amount of 50 mol% or more based on the total amount of the fatty acid (a1) and the balance is a fatty acid having 10 to 16 carbon atoms, the fatty acid (a1) is It will contain two or more fatty acids. In this case, the polyol ester (A) may be a mixture of two or more types of ester of one type of fatty acid and polyol, but because of its excellent low temperature characteristics and compatibility with the refrigerant, the ester of two or more types of mixed fatty acid and polyol. Is more preferable.
The polyol ester (A) may be a partial ester in which all the hydroxyl groups of the polyol remain without esterification, a complete ester in which all the hydroxyl groups are esterified, or a partial ester. It may be a mixture of complete esters, but is preferably complete esters.

Polyol ester (A) preferably has 40 ° C. kinematic viscosity of 30~500mm ² / s, more preferably 40~200mm ² / s. 100 ° C. kinematic viscosity is not particularly limited, is preferably from 5 to 50 mm ² / s, more preferably 8~25mm ² / s.
The viscosity index is not particularly limited from the viewpoint of improving the viscosity characteristics, but is preferably 40 or more, more preferably 60 or more, and particularly preferably 80 or more. The upper limit of the viscosity index is not particularly limited, but is usually about 200 or less.

The hydroxyl value of the polyol ester (A) is preferably 5 mgKOH / g or less. By setting the hydroxyl value to 5 mgKOH / g or less, the decomposition of the polyol ester (A) is appropriately suppressed, and the stability of the refrigerating machine lubricating oil can be improved. From the above viewpoint, the hydroxyl value of the polyol ester (A) is preferably 4 mgKOH / g or less, more preferably 3.5 mgKOH / g or less. The hydroxyl value is measured by the neutralization titration method according to JIS K0070.
The acid value of the polyol ester (A) is preferably 0.1 mgKOH / g or less, preferably 0.05 mgKOH / g or less, from the viewpoint of suppressing its decomposition and enhancing the stability of the refrigerating machine oil composition. More preferably. The acid value is measured by the indicator method in accordance with the "lubricating oil neutralization test method" specified in JIS K 2501.

Further, the fact that the chiller lubricating oil contains the polyol ester (A) as a main component means that the chiller lubricating oil contains 50% by mass or more of the polyol ester (A) based on the total amount of the chiller lubricating oil. Based on the total amount of the refrigerating machine lubricating oil, it is preferably 70% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more.
The refrigerating machine lubricating oil may contain only the above-mentioned polyol ester (A) as the base oil, but may contain a base oil other than the polyol ester (A) as long as the effect of the present invention is not impaired. Good. Examples of the base oil other than the polyol ester (A) include polyesters other than the polyol ester (A), polyoxyalkylene glycols, polyvinyl ethers, poly (oxy) alkylene glycol or a copolymer of the monoether and polyvinyl ether. , Polycarbonates, hydrides of α-olefin oligomers, mineral oils, alicyclic hydrocarbon compounds, alkylated aromatic hydrocarbon compounds and the like.
Examples of polyesters other than the polyol ester (A) include polyol esters of 2 to 20-valent polyhydric alcohols, preferably 2 to 10-valent polyhydric alcohols, and fatty acids.

[Additive]
In addition to the base oil, the chiller lubricating oil of the present invention may contain at least one additive selected from extreme pressure agents, oily agents, antioxidants, acid scavengers, defoamers and the like. Good.
Examples of the extreme pressure agent include phosphorus-based extreme pressure agents such as phosphoric acid ester, acidic phosphoric acid ester, phosphite ester, acidic phosphite ester and amine salts thereof.
Among these phosphorus-based extreme pressure agents, tricresyl phosphate, trithiophenyl phosphate, tri (nonylphenyl) phosphite, dioleyl hydrogen phosphite, 2-ethylhexyldiphenyl phosphite in terms of extreme pressure properties and frictional properties. Etc. are particularly preferable.

Moreover, as an extreme pressure agent, a metal salt of a carboxylic acid can be mentioned. The metal salt of the carboxylic acid referred to here is preferably a carboxylic acid having 3 to 60 carbon atoms, and further a metal salt of a fatty acid having 3 to 30 carbon atoms, particularly 12 to 30 carbon atoms. Further, examples thereof include dimer acids and trimer acids of the fatty acids and metal salts of dicarboxylic acids having 3 to 30 carbon atoms. Of these, fatty acids having 12 to 30 carbon atoms and metal salts of dicarboxylic acids having 3 to 30 carbon atoms are particularly preferable.
On the other hand, as the metal constituting the metal salt, an alkali metal or an alkaline earth metal is preferable, and an alkali metal is particularly preferable.
Further, examples of extreme pressure agents other than the above include sulfur-based extreme pressure agents such as sulfide fats and oils, sulfide fatty acids, sulfide esters, thiocarbamates, thioterpens, and dialkylthiodipropionates.
From the viewpoint of lubricity and stability, the blending amount of the extreme pressure agent is usually 0.001 to 5% by mass, particularly preferably 0.005 to 3% by mass, based on the total amount of the refrigerating machine lubricating oil.
One type of extreme pressure agent may be used alone, or two or more types may be used in combination.

Examples of oily agents include aliphatic saturated and unsaturated monocarboxylic acids such as stearic acid and oleic acid, polymerized fatty acids such as dimer acid and hydrogenated dimer acid, hydroxy fatty acids such as ricinoleic acid and 12-hydroxystearic acid, and lauryl. Fatty acid saturated and unsaturated monoalcohols such as alcohol and oleic alcohol, aliphatic saturated and unsaturated monoamines such as stearic acid and oleic acid, aliphatic saturated and unsaturated monocarboxylic acid amides such as laurate amide and oleic acid amide, etc. Can be mentioned.
One of these may be used alone, or two or more thereof may be used in combination. The blending amount is usually selected in the range of 0.01 to 10% by mass, preferably 0.1 to 5% by mass, based on the total amount of the refrigerating machine lubricating oil.

Antioxidants include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, and 2,2'-methylenebis (4-methyl-6-tert). It is preferable to add a phenol-based antioxidant such as −butylphenol) or an amine-based antioxidant such as phenyl-α-naphthylamine and N, N'-diphenyl-p-phenylenediamine. The blending amount of the antioxidant is usually 0.01 to 5% by mass, preferably 0.05 to 3% by mass, based on the total amount of the refrigerating machine lubricating oil from the viewpoint of effect and economy.

Examples of the acid trapping agent include epoxy compounds such as phenylglycidyl ether, alkylglycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxide, and epoxidized soybean oil. Of these, phenylglycidyl ether, alkylglycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, and α-olefin oxide are preferable in terms of compatibility.
The alkyl group of the alkyl glycidyl ether and the alkylene group of the alkylene glycol glycidyl ether may have a branch and have a carbon number of usually 3 to 30, preferably 4 to 24, particularly 6 to 16. Further, the α-olefin oxide generally has a total carbon number of 4 to 50, preferably 4 to 24, particularly 6 to 16. In the present invention, the acid scavenger may be used alone or in combination of two or more. Further, the blending amount is usually 0.005 to 5% by mass, particularly preferably 0.05 to 3% by mass, based on the total amount of the refrigerating machine lubricating oil from the viewpoint of the effect and suppression of sludge generation.
In the present invention, the stability of the refrigerating machine oil composition can be improved by blending this acid scavenger. Further, by using the extreme pressure agent and the antioxidant in combination, the effect of further improving the stability is exhibited.
Examples of the defoaming agent include silicone oil and fluorinated silicone oil.
The refrigerating machine lubricating oil of the present invention may be further blended with various other known additives as long as the object of the present invention is not impaired.

The above-mentioned refrigerating machine lubricating oil is mixed with a refrigerant and used in a refrigerating machine as a mixing composition for a refrigerating machine. In the mixed composition for a refrigerator, the mass ratio of the refrigerant (refrigerant / refrigerator lubricant) to the refrigerator lubricant is preferably 99/1 to 10/90, and is in the range of 95/5 to 30/70. More preferably, it is more preferably in the range of 95/5 to 40/60.
When the mass ratio is in the above range, the refrigerating capacity and the lubricating performance can be improved in a well-balanced manner.

[Lubrication method and refrigerator]
The lubrication method of the present invention is a lubrication method using the above-mentioned refrigerating machine lubricating oil in a refrigerating machine using the above-mentioned refrigerant.
The refrigerator is provided with the refrigerant and the refrigerating machine lubricating oil to be mixed with the refrigerant, and any device constituting the refrigerating machine is provided with a mixing composition for the refrigerating machine or a rubber member in contact with the refrigerating machine lubricating oil. Is. The mixed composition for a refrigerator and the lubricating oil for the refrigerator come into contact with the rubber member, and the lubricating oil for the refrigerator of the present invention can suppress swelling of the rubber. Therefore, the chiller of the present invention can suppress chiller lubricating oil leakage and refrigerant leakage due to rubber swelling.
Further, the refrigerator of the present invention is a compression type refrigerator including at least a compressor, and the rubber member described above is preferably a rubber member provided in the compressor.

The rubber member is not particularly limited, but hydrogenated nitrile rubber (H-NBR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene / propylene / diene ternary copolymer (EPDM), silicone rubber, and the like. Examples thereof include butyl rubber (IIR), styrene-butadiene rubber (SBR), urethane rubber (U), chlorosulfonated polyethylene (CSM), fluororubber (FKM), and among these, hydrogenated nitrile rubber, chloroprene rubber, and the like. It is preferable to use an ethylene / propylene / diene ternary copolymer.

The refrigerator includes, for example, a compressor, a condenser, an expansion mechanism (expansion valve, etc.) and an evaporator, or a compressor, a condenser, an expansion mechanism, a dryer and an evaporator, which constitute a refrigeration cycle. The refrigerant used in combination with the chiller lubricating oil circulates in the refrigeration cycle and repeatedly absorbs and releases heat. The refrigerating machine lubricating oil lubricates a sliding portion of a refrigerating machine, for example, a compressor.

The refrigerator of the present invention can be applied to, for example, car air conditioners, gas heat pumps (GHP), air conditioners, refrigerators, vending machines, showcases, water dispensers, refrigerating system such as floor heating, hot water supply systems, and heating systems. It can be preferably used for car air conditioners such as electric car air conditioners and open car air conditioners, and is particularly suitable for open car air conditioners.
In each system to which the refrigerator is applied, it is preferable that the water content in the system system is 300 mass ppm or less and the residual air partial pressure is 10 kPa or less. The water content is more preferably 200 mass ppm or less, and the residual air partial pressure is more preferably 5 kPa or less.

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.
The evaluation of each physical property in the present invention was carried out by the following method.
[Evaluation methods]
(1) 40 ° C. kinematic viscosity, 100 ° C. kinematic viscosity The measurement was performed using a glass capillary viscometer according to JIS K2283.
(2) Viscosity index The viscosity index was calculated in accordance with JIS K 2283.
(3) Compatibility test The two-layer separation temperature measuring tube (internal volume 10 mL) was filled with the lubricating oil for the refrigerator and the refrigerant, and kept in a constant temperature bath. The temperature of the constant temperature bath was raised from room temperature (25 ° C.) to 80 ° C. at a rate of 1 ° C./min, and the two-layer separation temperature on the high temperature side was measured. Those in which the two layers are not separated up to 80 ° C. are indicated by "80 <" in the table, and those in which the refrigerant and the chiller lubricating oil are incompatible are indicated as "insoluble".
Further, the temperature of the constant temperature bath was lowered from room temperature (25 ° C.) to −50 ° C. at a rate of 1 ° C./min, and the two-layer separation temperature on the low temperature side was measured. Those in which the two layers are not separated up to −50 ° C. are indicated by “-50>” in the table, and those in which the refrigerant and the chiller lubricating oil are incompatible are indicated as “insoluble”.
The compatibility test was carried out when the ratio of the refrigerant to the total amount of the mixed composition for each refrigerator was 5% by mass, 10% by mass, 15% by mass, 20% by mass, and 30% by mass, respectively.
(4) Rubber Compatibility Test In an autoclave test, a rubber sample having a size of 10 mm × 10 mm and a thickness of 2 mm was immersed in a mixed composition for a refrigerator to evaluate the rubber swelling property of the mixed composition for a refrigerator. In this test, a mixed composition for a refrigerator having a mass ratio of the lubricating oil for the refrigerator and the refrigerant of 20: 8.5 was used.
Rubber sample: HNBR, CR, EPDM
Test temperature: 175 ° C, test time: 24 hours Evaluation items: weight change rate (%), volume change rate (%)

Examples 1 to 15, Comparative Examples 1 to 19
The carboxylic acid shown in Table 1 and the polyol ester of the polyhydric alcohol were used as the lubricating oil for the refrigerator. Further, using R1234yf as the refrigerant, a mixed composition for a refrigerator composed of a refrigerating machine lubricating oil and a refrigerant was prepared, and a compatibility test and a rubber compatibility test were carried out. Furthermore, the kinematic viscosity and viscosity index of the polyol ester (refrigerator lubricating oil) were also measured. The results are shown in Table 2.

Each abbreviation in Table 1 is as follows.
nC6: n-hexanoic acid nC7: n-heptane Branched C8: 2-ethylhexanoic acid Branched C9: 3,5,5-trimethylhexanoic acid neoC10: Neodecanoic acid Branched C12: 2-butyloctanoic acid Branched C16: Isopalmitic acid C18T: Linoleic acid C18': Oleic acid
Branched C18: Isostearic acid Branched C24: Isotetracosanoic acid C24: Tetracosanoic acid PE: Pentaerythritol DPE: Dipentaerythritol

As shown in Examples 1 to 15 above, the fatty acid (a1) consisting of only the fatty acid having 9 carbon atoms or the fatty acid having 9 carbon atoms is 50 mol% or more based on the total amount of the fatty acid (a1), and the fatty acid thereof. Unsaturation by using a polyol ester (A) of a fatty acid (a1) whose residue is a fatty acid having 10 to 16 carbon atoms and a polyol (a2) having pentaerythritol and / or dipentaerythritol as a base oil. It was possible to appropriately suppress rubber swelling while improving compatibility with the fluorinated hydrocarbon fatty acid.
On the other hand, as shown in each comparative example, when a fatty acid having 8 or less carbon atoms or a fatty acid having 17 or more carbon atoms is used as the fatty acid (a1), the compatibility is lowered and the rubber swelling cannot be sufficiently suppressed. , Sufficient performance could not be exhibited as a refrigerating machine lubricating oil for unsaturated fluorinated hydrocarbon refrigerants.

The mixed composition for a refrigerator of the present invention can be used for car air conditioners, gas heat pumps (GHP), air conditioners, refrigerators, vending machines, showcases, water heaters, floor heating, etc. It can be suitably used for car air conditioners such as electric car air conditioners.

Claims (12)

The following molecular formula (1)
_Cp F _r H _s ... (1)
[In the formula, p is an integer of 2 to 6, r is an integer of 1 to 11, and s is an integer of 1 to 11, and has one or more carbon-carbon unsaturated bonds in the molecule. ]
A refrigerant containing at least one unsaturated fluorinated hydrocarbon compound selected from the compounds represented by
A fatty acid (a1) containing a fatty acid having 9 carbon atoms and a fatty acid having 10 to 16 carbon atoms, wherein the fatty acid having 9 carbon atoms is 50 mol% or more based on the total amount of the fatty acid (a1). It contains a refrigerating machine lubricating oil containing a polyol ester (A) as a main component with a polyol (a2) which is pentaerythritol and / or dipentaerythritol.
The fatty acids having 10 to 16 carbon atoms are n-decanoic acid, n-undecanoic acid, lauric acid (n-dodecanoic acid), n-tridecanoic acid, myristic acid (n-tetradecanoic acid), n-pentadecylic acid, and palmitic acid. Selected from (n-hexadecanoic acid), neodecanoic acid, branched undecanoic acid, branched dodecanoic acid, branched tridecanoic acid, branched tetradecanoic acid, branched pentadecane acid, and branched hexadecanoic acid.
Hydrogenated nitrile rubber (H-NBR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene / propylene / diene ternary copolymer (EPDM), silicone rubber, butyl rubber (IIR), styrene butadiene rubber (SBR) , Urethane rubber (U), chlorosulfonated polyethylene (CSM), and fluororubber (FKM) .
You contact with the rubber member in the refrigerator, the refrigerator mix composition. The mixed composition for a refrigerator according to claim 1, wherein the unsaturated fluorinated hydrocarbon compound is a fluoride of propene. Fluoride of the propene is derived from various isomers of pentafluoropropene, 3,3,3-trifluoropropene, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetrafluoropropene. The mixed composition for a refrigerator according to claim 2, which is at least one selected. The mixed composition for a refrigerator according to any one of claims 1 to 3, wherein the refrigerant comprises only the unsaturated fluorinated hydrocarbon compound. The mixed composition for a refrigerator according to any one of claims 1 to 4, wherein the fatty acid having 9 carbon atoms and the fatty acid having 10 to 16 carbon atoms contain a branched fatty acid. The refrigeration according to any one of claims 1 to 5, wherein the refrigerator lubricant contains at least one additive selected from extreme pressure agents, oily agents, antioxidants, acid scavengers, and antifoaming agents. Machine mix composition. The refrigerant further contains a saturated fluorinated hydrocarbon compound.
One of claims 1 to 3 and 5 to 6, wherein the saturated fluorinated hydrocarbon compound is at least one selected from 1,1-difluoroethane, trifluoroethane, tetrafluoroethane, and pentafluoroethane. The mixed composition for a refrigerator according to the above. 7. Mixing composition for refrigerating machine. The mixed composition for a refrigerator according to claim 8, wherein the water content in the system is 300 mass ppm or less and the residual air partial pressure is 10 kPa or less. The following molecular formula (1)
_Cp F _r H _s ... (1)
[In the formula, p is an integer of 2 to 6, r is an integer of 1 to 11, and s is an integer of 1 to 11, and has one or more carbon-carbon unsaturated bonds in the molecule. ]
It is used as a refrigerant containing at least one unsaturated fluorinated hydrocarbon compound selected from the compounds represented by, as a main component, and
Hydrogenated nitrile rubber (H-NBR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene / propylene / diene ternary copolymer (EPDM), silicone rubber, butyl rubber (IIR), styrene butadiene rubber (SBR) , Urethane rubber (U), chlorosulfonated polyethylene (CSM), and fluororubber (FKM).
A fatty acid (a1) containing a fatty acid having 9 carbon atoms and a fatty acid having 10 to 16 carbon atoms, wherein the fatty acid having 9 carbon atoms is 50 mol% or more based on the total amount of the fatty acid (a1). Containing a polyol ester (A) with a polyol (a2) which is pentaerythritol and / or dipentaerythritol as a main component ,
The fatty acids having 10 to 16 carbon atoms are n-decanoic acid, n-undecanoic acid, lauric acid (n-dodecanoic acid), n-tridecanoic acid, myristic acid (n-tetradecanoic acid), n-pentadecylic acid, and palmitic acid. Selected from (n-hexadecanoic acid), neodecanoic acid, branched undecanoic acid, branched dodecanoic acid, branched tridecanoic acid, branched tetradecanoic acid, branched pentadecane acid, and branched hexadecanoic acid.
You contact with the rubber member in the refrigerator, refrigerator lubricating oil. The following molecular formula (1)
_Cp F _r H _s ... (1)
[In the formula, p is an integer of 2 to 6, r is an integer of 1 to 11, and s is an integer of 1 to 11, and has one or more carbon-carbon unsaturated bonds in the molecule. ]
A refrigerant containing at least one unsaturated fluorinated hydrocarbon compound selected from the compounds represented by is used as a main component, and
Hydrogenated nitrile rubber (H-NBR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene / propylene / diene ternary copolymer (EPDM), silicone rubber, butyl rubber (IIR), styrene butadiene rubber (SBR) In a refrigerator provided with a rubber member selected from any of urethane rubber (U), chlorosulfonated polyethylene (CSM), and fluororubber (FKM).
A fatty acid (a1) containing a fatty acid having 9 carbon atoms and a fatty acid having 10 to 16 carbon atoms, wherein the fatty acid having 9 carbon atoms is 50 mol% or more based on the total amount of the fatty acid (a1). A lubrication method using a refrigerating machine lubricating oil containing a polyol ester (A) as a main component with a polyol (a2) which is pentaerythritol and / or dipentaerythritol.
The fatty acids having 10 to 16 carbon atoms are n-decanoic acid, n-undecanoic acid, lauric acid (n-dodecanoic acid), n-tridecanoic acid, myristic acid (n-tetradecanoic acid), n-pentadecylic acid, and palmitic acid. Selected from (n-hexadecanoic acid), neodecanoic acid, branched undecanoic acid, branched dodecanoic acid, branched tridecanoic acid, branched tetradecanoic acid, branched pentadecane acid, and branched hexadecanoic acid.
A lubrication method in which the refrigerating machine lubricating oil comes into contact with the rubber member. The following molecular formula (1)
_Cp F _r H _s ... (1)
[In the formula, p is an integer of 2 to 6, r is an integer of 1 to 11, and s is an integer of 1 to 11, and has one or more carbon-carbon unsaturated bonds in the molecule. ]
A refrigerant containing at least one unsaturated fluorinated hydrocarbon compound selected from the compounds represented by
A fatty acid (a1) containing a fatty acid having 9 carbon atoms and a fatty acid having 10 to 16 carbon atoms, wherein the fatty acid having 9 carbon atoms is 50 mol% or more based on the total amount of the fatty acid (a1). A refrigerator lubricating oil containing a polyol ester (A) as a main component with a polyol (a2) which is pentaerythritol and / or dipentaerythritol is provided.
Hydrogenated nitrile rubber (H-NBR), nitrile rubber (NBR), chloroprene rubber (CR), ethylene / propylene / diene ternary copolymer (EPDM), silicone rubber, butyl rubber (IIR), styrene butadiene rubber (SBR) , Urethane rubber (U), chlorosulfonated polyethylene (CSM), and fluororubber (FKM) .
The fatty acids having 10 to 16 carbon atoms are n-decanoic acid, n-undecanoic acid, lauric acid (n-dodecanoic acid), n-tridecanoic acid, myristic acid (n-tetradecanoic acid), n-pentadecylic acid, and palmitic acid. Selected from (n-hexadecanoic acid), neodecanoic acid, branched undecanoic acid, branched dodecanoic acid, branched tridecanoic acid, branched tetradecanoic acid, branched pentadecane acid, and branched hexadecanoic acid.
Refrigerator A refrigerator in which the lubricating oil comes into contact with the rubber member .