Refrigeration cycle device, refrigeration oil and refrigerant leakage prevention agent

Abstract

The present invention provides a novel refrigeration cycle device, refrigeration oil and refrigerant leakage preventing agent that can effectively deal with refrigerant leakage. The refrigeration cycle device comprises a working fluid for a refrigerator, the working fluid for a refrigerator contains a refrigeration oil and a refrigerant composition, the refrigeration oil contains a D 50 and D of 4.0 to 14.0 90 / D 10 The refrigerant composition contains a refrigerant.

Description

[0001] This case is filed on April 27, 2020 、Application number is 202080089969.4 (PCT / JP2020 / 017971) , divisional application for invention titled Refrigeration cycle device, refrigeration oil and refrigerant leakage preventer. Technical Field

[0002] The invention relates to a refrigeration cycle device, refrigeration oil and a refrigerant leakage preventing agent. Background Art

[0003] Patent document 1 below discloses a method for injecting a sealing material for a refrigerating device and a refrigerating device for plugging holes with a pore size of 10 μm or less, wherein particles with an average particle size of 0.05 to 5.00 μm are used as particles for sealing. It is described that using the refrigerating device and the method for injecting a sealing material for a refrigerating device, a more reliable and stable seal can be achieved over a long period of time compared to the prior art.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-75221 Summary of the invention

[0007] Technical problem to be solved by the invention

[0008] The refrigerant leakage rate needs to be further reduced, and an object of the present invention is to provide a novel refrigeration cycle device, refrigeration oil and refrigerant leakage preventer.

[0009] Technical solutions for solving technical problems

[0010] The present invention includes the following aspects.

[0011] [1] A refrigeration cycle device comprising a refrigerator working fluid, wherein the refrigerator working fluid comprises a refrigerator oil and a refrigerant composition, wherein the refrigerator oil comprises a refrigerant composition having a D 50 and D of 4.0 to 14.0 90 / D 10 The refrigerant composition contains a refrigerant.

[0012] [2] The refrigeration cycle device according to the above [1], wherein the resin particles have a standard deviation of 3.0 μm to 8.0 μm.

[0013] [3] The refrigeration cycle device according to [1] or [2] above, wherein the resin particles are fluorine-containing resin particles.

[0014] [4] The refrigeration cycle device according to the above [3], wherein the fluorine-containing resin particles are polytetrafluoroethylene particles.

[0015] [5] A refrigerating machine oil containing a D having a particle size of 2.0 μm to 10.0 μm. 50 and D of 4.0~14.0μm 90 / D 10 of resin particles.

[0016] [6] The refrigerating machine oil according to [5] above, wherein the resin particles have a standard deviation of 3.0 μm to 8.0 μm.

[0017] [7] The refrigerating machine oil according to [5] or [6] above, wherein the resin particles are fluorine-containing resin particles.

[0018] [8] The refrigerating machine oil according to [7] above, wherein the fluorine-containing resin particles are polytetrafluoroethylene particles.

[0019] [9] A refrigerant leakage preventer comprising the refrigeration oil according to any one of [5] to [8] above.

[0020] Effects of the Invention

[0021] The refrigeration cycle device and refrigeration oil of the present invention contain resin particles with a relatively wide particle size distribution, thereby further reducing the refrigerant leakage rate. In addition, the refrigerant leakage prevention agent of the present invention is injected into the refrigeration cycle device before operation, thereby realizing the refrigeration cycle device of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a diagram showing an example of a refrigerant circuit included in a refrigeration cycle device.

[0023] Explanation of symbols

[0024] 1: Air conditioning device; 2: Outdoor unit; 3: Indoor unit; 4: Compressor; 5: Outdoor heat exchanger; 6: Expansion valve; 7: Outdoor heat exchanger; 8: Gas-side refrigerant connection piping; 9: Liquid-side refrigerant connection piping; 10: Refrigerant circuit or four-way switching valve; 11: Liquid accumulator; 12: Outdoor fan; 13: Indoor fan; 14: Liquid-side closing valve; 15: Gas-side closing valve. DETAILED DESCRIPTION

[0025] Next, specific embodiments of the present invention will be described in detail.

[0026] (1) Refrigeration cycle device

[0027] The refrigeration cycle apparatus of the present invention comprises the refrigerant composition described in the column (4) described later, and refrigerating machine oil.

[0028] (2) Refrigeration oil

[0029] When a refrigeration cycle such as a refrigeration cycle is performed in the presence of the refrigeration oil and the refrigerant composition, the lubricity in the refrigeration cycle device can be improved and efficient cycle performance can be exhibited.

[0030] As refrigeration oil, for example, oxygen-containing synthetic oil (ester refrigeration oil, ether refrigeration oil, etc.), hydrocarbon refrigeration oil, etc. can be cited. Among them, from the viewpoint of compatibility with refrigerants or refrigerant compositions, ester refrigeration oils and ether refrigeration oils are preferred. As refrigeration oil, one kind can be used alone, or two or more kinds can be used in combination.

[0031] From at least any one of the viewpoints of suppressing the reduction of lubricity and airtightness of the compressor, ensuring compatibility with the refrigerant under low temperature conditions, suppressing poor lubrication of the compressor, and improving the heat exchange efficiency of the evaporator, the refrigeration oil preferably has a kinematic viscosity of 1 mm at 40°C. 2 / s above 750mm 2 / s or less, more preferably 1mm 2 / s above 400mm 2 / s or less. The kinematic viscosity of the refrigeration oil at 100°C may be, for example, 1 mm 2 / s above 100mm 2 / s or less, more preferably 1mm 2 / s above 50mm 2 / s or less.

[0032] The aniline point of the refrigeration oil is preferably -100°C or more and 0°C or less. Among them, the "aniline point" is a numerical value indicating the solubility of, for example, a hydrocarbon solvent, and indicates the temperature at which a sample (here, the refrigeration oil) becomes immiscible with an equal volume of aniline and begins to become turbid when it is mixed and cooled (specified in JIS K 2256). In addition, these values ​​are the values ​​of the refrigeration oil itself in a state where the refrigerant is not dissolved. By using a refrigeration oil with such an aniline point, for example, even when the refrigeration oil is used at a position where the insulating material of each bearing and motor constituting the resin functional component contacts the refrigeration oil, the adaptability of the refrigeration oil to these resin functional components can be improved. Specifically, when the aniline point is too low, the refrigeration oil easily penetrates the bearing and the insulating material, and the bearing, etc. easily swells. On the other hand, when the aniline point is too high, the refrigeration oil is difficult to penetrate the bearing and the insulating material, and the bearing, etc. easily shrinks. Therefore, by using a refrigeration oil with an aniline point in the above-mentioned specified range (-100°C or more and 0°C or less), swelling / shrinkage deformation of the bearing or the insulating material can be prevented. Here, once each bearing swells and deforms, the gap (interval) of the sliding part cannot be maintained at the desired length. As a result, the sliding resistance may increase. Once each bearing shrinks and deforms, the hardness of the bearing will increase, and the bearing may be damaged due to the vibration of the compressor. In other words, once each bearing shrinks and deforms, the rigidity of the sliding part may decrease. In addition, once the insulating material (insulating covering material, insulating film, etc.) of the motor swells and deforms, the insulation of the insulating material will decrease. Once the insulating material shrinks and deforms, the insulating material may be damaged as in the case of the above-mentioned bearings, and in this case, the insulation will also decrease. In contrast, by using a refrigeration oil with an aniline point within the specified range as described above, the swelling / shrinkage deformation of the bearings and the insulating material can be suppressed, thereby avoiding such undesirable conditions.

[0033] The refrigerator oil is mixed with the refrigerant composition and used as a refrigerator working fluid. The mixing ratio of the refrigerator oil to the total amount of the refrigerator working fluid is preferably 5 mass % to 60 mass %, more preferably 10 mass % to 50 mass %.

[0034] (2-1) Oxygen-containing synthetic oil

[0035] Ester refrigeration oil and ether refrigeration oil, which are oxygen-containing synthetic oils, are mainly composed of carbon atoms and oxygen atoms. In ester refrigeration oil or ether refrigeration oil, when the ratio of carbon atoms to oxygen atoms (carbon / oxygen molar ratio) is too small, the hygroscopicity becomes high; when the ratio is too large, the compatibility with the refrigerant decreases, so the ratio is preferably 2 or more and 7.5 or less in terms of molar ratio.

[0036] (2-1-1) Ester Refrigeration Oil

[0037] As ester-based refrigeration oils, from the viewpoint of chemical stability, base oil components include dibasic acid ester oils of dibasic acids and monohydric alcohols, polyol ester oils of polyols and fatty acids, or complex ester oils of polyols, polyacids and monohydric alcohols (or fatty acids), and polyol carbonate oils.

[0038] (Dibasic acid ester oil)

[0039] As the dibasic acid ester oil, esters of dibasic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, and terephthalic acid, in particular, dibasic acids having 5 to 10 carbon atoms (glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, etc.) and monohydric alcohols having 1 to 15 carbon atoms (methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecyl alcohol, etc.) having a linear or branched alkyl group are preferred. Specific examples of the dibasic acid ester oil include ditridecyl glutarate, di(2-ethylhexyl) adipate, diisodecyl adipate, ditridecyl adipate, di(3-ethylhexyl) sebacate, etc.

[0040] (Polyol ester oil)

[0041] The polyol ester oil is an ester synthesized from a polyol and a fatty acid (carboxylic acid), and has a carbon / oxygen molar ratio of 2 to 7.5, preferably 3.2 to 5.8.

[0042] Examples of the polyol constituting the polyol ester oil include diols (ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 1,7-heptanediol, 2-methyl-2-propyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, etc.), polyols having 3 to 20 hydroxyl groups (trimethylolethane, trimethylolpropane, trimethylolbutane, etc.), , di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol, di-(pentaerythritol), tri-(pentaerythritol), glycerol, polyglycerol (dimer to trimer of glycerol), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol glycerol condensate, adonitol, arabitol, xylitol, mannitol and other polyols, xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbitol, cellobiose, maltose, isomaltose, trehalose, sucrose, raffinose, gentiotriose, melezitose and other sugars and their partial etherification products, etc.), the polyol constituting the ester may be one of the above-mentioned ones or may contain two or more of the above-mentioned ones.

[0043] The number of carbon atoms of the fatty acid constituting the polyol ester is not particularly limited, and generally, a fatty acid having 1 to 24 carbon atoms is used. Straight-chain fatty acids and branched fatty acids are preferred. Straight-chain fatty acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, eicosanoic acid, oleic acid, linoleic acid, linolenic acid, and the like. The hydrocarbon groups bonded to the carboxyl group may all be saturated hydrocarbons or may have unsaturated hydrocarbons.Examples of branched fatty acids include 2-methylpropionic acid, 2-methylbutyric acid, 3-methylbutyric acid, 2,2-dimethylpropionic acid, 2-methylvaleric acid, 3-methylvaleric acid, 4-methylvaleric acid, 2,2-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3,3-dimethylbutyric acid, 2-methylhexanoic acid, 3-methylhexanoic acid, 4-methylhexanoic acid, 5-methylhexanoic acid, 2,2-dimethylvaleric acid, 2,3-dimethylvaleric acid, 2,4-dimethylvaleric acid, 3,3-dimethylvaleric acid, 3,4-dimethylvaleric acid, 4,4-dimethylvaleric acid, 2-ethylvaleric acid, 3-ethylvaleric acid, 2,2,3-trimethylvaleric acid, Butyric acid, 2,3,3-trimethylbutyric acid, 2-ethyl-2-methylbutyric acid, 2-ethyl-3-methylbutyric acid, 2-methylheptanoic acid, 3-methylheptanoic acid, 4-methylheptanoic acid, 5-methylheptanoic acid, 6-methylheptanoic acid, 2-ethylhexanoic acid, 3-ethylhexanoic acid, 4-ethylhexanoic acid, 2,2-dimethylhexanoic acid, 2,3-dimethylhexanoic acid, 2,4-dimethylhexanoic acid, 2,5-dimethylhexanoic acid, 3,3-dimethylhexanoic acid, 3,4-dimethylhexanoic acid, 3,5-dimethylhexanoic acid, 4,4-dimethylhexanoic acid, 4,5-dimethylhexanoic acid, 5,5-dimethylhexanoic acid, 2-propylpentanoic acid, 2-methyloctanoic acid, 3-methylhexanoic acid, octanoic acid, 4-methyloctanoic acid, 5-methyloctanoic acid, 6-methyloctanoic acid, 7-methyloctanoic acid, 2,2-dimethylheptanoic acid, 2,3-dimethylheptanoic acid, 2,4-dimethylheptanoic acid, 2,5-dimethylheptanoic acid, 2,6-dimethylheptanoic acid, 3,3-dimethylheptanoic acid, 3,4-dimethylheptanoic acid, 3,5-dimethylheptanoic acid, 3,6-dimethylheptanoic acid, 4,4-dimethylheptanoic acid, 4,5-dimethylheptanoic acid, 4,6-dimethylheptanoic acid, 5,5-dimethylheptanoic acid, 5,6-dimethylheptanoic acid, 6,6-dimethylheptanoic acid, 2-methyl-2-ethylhexanoic acid, 2-methyl-3-ethylhexanoic acid, 2-methyl- 4-ethylhexanoic acid, 3-methyl-2-ethylhexanoic acid, 3-methyl-3-ethylhexanoic acid, 3-methyl-4-ethylhexanoic acid, 4-methyl-2-ethylhexanoic acid, 4-methyl-3-ethylhexanoic acid, 4-methyl-4-ethylhexanoic acid, 5-methyl-2-ethylhexanoic acid, 5-methyl-3-ethylhexanoic acid, 5-methyl-4-ethylhexanoic acid, 2-ethylheptanoic acid, 3-methyloctanoic acid, 3,5,5-trimethylhexanoic acid, 2-ethyl-2,3,3-trimethylbutanoic acid, 2,2,4,4-tetramethylpentanoic acid, 2,2,3,3-tetramethylpentanoic acid, 2,2,3,4-tetramethylpentanoic acid, 2,2-diisopropylpropionic acid, etc. The fatty acid may be an ester with one or more fatty acids selected from these.

[0044] The polyol constituting the ester may be one kind or a mixture of two or more kinds. In addition, the fatty acid constituting the ester may be a single component or an ester with two or more kinds of fatty acids. The fatty acid may be one kind or a mixture of two or more kinds. In addition, the polyol ester oil may also have free hydroxyl groups.

[0045] As specific polyol ester oils, esters of hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di(trimethylolpropane), tri(trimethylolpropane), pentaerythritol, di(pentaerythritol), and tri(pentaerythritol) are more preferred; esters of neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, and di(pentaerythritol) are further preferred; esters of neopentyl glycol, trimethylolpropane, pentaerythritol, di(pentaerythritol), and the like with fatty acids having 2 to 20 carbon atoms are preferred.

[0046] In the fatty acid constituting such a polyol fatty acid ester, the fatty acid may be only a fatty acid having a straight-chain alkyl group, or may be selected from a fatty acid having a branched structure. It may also be a mixed ester of a straight-chain fatty acid and a branched fatty acid. Further, the fatty acid constituting the ester may also use two or more selected from the above-mentioned fatty acids.

[0047] As a specific example, in the case of a mixed ester of a straight-chain fatty acid and a branched-chain fatty acid, the molar ratio of a fatty acid having 4 to 6 carbon atoms in a straight chain to a fatty acid having 7 to 9 carbon atoms in a branched chain is 15:85 to 90:10, preferably 15:85 to 85:15, more preferably 20:80 to 80:20, further preferably 25:75 to 75:25, and most preferably 30:70 to 70:30. In addition, the total proportion of a fatty acid having 4 to 6 carbon atoms in a straight chain and a fatty acid having 7 to 9 carbon atoms in a branched chain in the total amount of fatty acids constituting the polyol fatty acid ester is preferably 20 mol% or more. Regarding the fatty acid composition, it is preferred to take into account both the sufficient compatibility with the refrigerant and the viscosity required as a refrigerating machine oil. In addition, the ratio of fatty acids mentioned here is a value based on the total amount of fatty acids constituting the polyol fatty acid ester contained in the refrigerating machine oil.

[0048] Among them, as such a refrigeration oil, it is preferred to contain the following ester (hereinafter referred to as "polyol fatty acid ester (A)"): the molar ratio of fatty acids with 4 to 6 carbon atoms to branched fatty acids with 7 to 9 carbon atoms in the fatty acids is 15:85 to 90:10, the fatty acids with 4 to 6 carbon atoms contain 2-methylpropionic acid, and the total of fatty acids with 4 to 6 carbon atoms and branched fatty acids with 7 to 9 carbon atoms accounts for more than 20 mol% of the total amount of fatty acids constituting the above-mentioned ester.

[0049] The polyol fatty acid ester (A) includes complete esters in which all hydroxyl groups of the polyol are esterified, partial esters in which a part of the hydroxyl groups of the polyol remain unesterified, and mixtures of complete esters and partial esters. The hydroxyl value of the polyol fatty acid ester (A) is preferably 10 mgKOH / g or less, more preferably 5 mgKOH / g or less, and most preferably 3 mgKOH / g or less.

[0050] In the fatty acids constituting the polyol fatty acid ester (A), the molar ratio of the fatty acid having 4 to 6 carbon atoms to the fatty acid having 7 to 9 carbon atoms with a branched chain is 15:85 to 90:10, preferably 15:85 to 85:15, more preferably 20:80 to 80:20, further preferably 25:75 to 75:25, and most preferably 30:70 to 70:30. In addition, the total proportion of the fatty acid having 4 to 6 carbon atoms and the fatty acid having 7 to 9 carbon atoms with a branched chain in the total amount of the fatty acids constituting the polyol fatty acid ester (A) is 20 mol% or more. In the case where the above conditions regarding the fatty acid composition are not met, when difluoromethane is contained in the refrigerant composition, it is difficult to take into account both the sufficient compatibility with the difluoromethane and the viscosity required as a refrigerating machine oil at a high level. Among them, the ratio of fatty acids is a value based on the total amount of fatty acids constituting the polyol fatty acid ester contained in the refrigerating machine oil.

[0051] Specific examples of the fatty acid having 4 to 6 carbon atoms include butyric acid, 2-methylpropionic acid, valeric acid, 2-methylbutyric acid, 3-methylbutyric acid, 2,2-dimethylpropionic acid, 2-methylvaleric acid, 3-methylvaleric acid, 4-methylvaleric acid, 2,2-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3,3-dimethylbutyric acid, and caproic acid. Among these, a fatty acid having a branched chain on the alkyl skeleton, such as 2-methylpropionic acid, is preferred.

[0052] Specific examples of the branched fatty acid having 7 to 9 carbon atoms include 2-methylhexanoic acid, 3-methylhexanoic acid, 4-methylhexanoic acid, 5-methylhexanoic acid, 2,2-dimethylpentanoic acid, 2,3-dimethylpentanoic acid, 2,4-dimethylpentanoic acid, 3,3-dimethylpentanoic acid, 3,4-dimethylpentanoic acid, 4,4-dimethylpentanoic acid, 2-ethylpentanoic acid, 3-ethylpentanoic acid, 1,1,2-trimethylbutanoic acid, 1,2,2-trimethylbutanoic acid, 1-ethyl-1-methylbutanoic acid, 1-ethyl-2-methylbutanoic acid, octanoic acid, 2-ethylhexanoic acid, 3-ethylhexanoic acid, 3,5 ...3,5-dimethylpentanoic acid, 3,5-dimethylpentanoic acid, 3,5-dimethylpentanoic acid, Methylhexanoic acid, 2,4-dimethylhexanoic acid, 3,4-dimethylhexanoic acid, 4,5-dimethylhexanoic acid, 2,2-dimethylhexanoic acid, 2-methylheptanoic acid, 3-methylheptanoic acid, 4-methylheptanoic acid, 5-methylheptanoic acid, 6-methylheptanoic acid, 2-propylpentanoic acid, nonanoic acid, 2,2-dimethylheptanoic acid, 2-methyloctanoic acid, 2-ethylheptanoic acid, 3-methyloctanoic acid, 3,5,5-trimethylhexanoic acid, 2-ethyl-2,3,3-trimethylbutanoic acid, 2,2,4,4-tetramethylpentanoic acid, 2,2,3,3-tetramethylpentanoic acid, 2,2,3,4-tetramethylpentanoic acid, 2,2-diisopropylpropionic acid, etc.

[0053] As long as the molar ratio of the fatty acid having 4 to 6 carbon atoms to the fatty acid having 7 to 9 carbon atoms with a branch is 15:85 to 90:10 and the fatty acid having 4 to 6 carbon atoms contains 2-methylpropionic acid, the polyol fatty acid ester (A) may contain fatty acids other than the fatty acid having 4 to 6 carbon atoms and the fatty acid having 7 to 9 carbon atoms with a branch as a constituent acid component.

[0054] Specific examples of fatty acids other than the above-mentioned fatty acids having 4 to 6 carbon atoms and branched fatty acids having 7 to 9 carbon atoms include: fatty acids having 2 to 3 carbon atoms such as acetic acid and propionic acid; straight-chain fatty acids having 7 to 9 carbon atoms such as heptanoic acid, octanoic acid, and nonanoic acid; fatty acids having 10 to 20 carbon atoms such as decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecanoic acid, eicosanoic acid, and oleic acid; and the like.

[0055] When the above-mentioned fatty acid having 4 to 6 carbon atoms and the fatty acid having 7 to 9 carbon atoms with a branched chain are used in combination with fatty acids other than these fatty acids, the total proportion of the fatty acid having 4 to 6 carbon atoms and the branched fatty acid having 7 to 9 carbon atoms in the total amount of fatty acids constituting the polyol fatty acid ester (A) is preferably 20 mol% or more, more preferably 25 mol% or more, and further preferably 30 mol% or more. When the proportion is 20 mol% or more, when difluoromethane is contained in the refrigerant composition, the compatibility with the difluoromethane is sufficient.

[0056] In the polyol fatty acid ester (A), it is particularly preferred that the acid constituents contain only 2-methylpropionic acid and 3,5,5-trimethylhexanoic acid from the viewpoint of ensuring the necessary viscosity and compatibility with difluoromethane when the refrigerant composition contains difluoromethane.

[0057] The above-mentioned polyol fatty acid ester may be a mixture of two or more esters having different molecular structures. In this case, it is not necessary for each molecule to satisfy the above-mentioned conditions as long as the fatty acid constituting the pentaerythritol fatty acid ester contained in the refrigeration oil satisfies the above-mentioned conditions as a whole.

[0058] As described above, in the polyol fatty acid ester (A), as the acid component constituting the ester, a fatty acid having 4 to 6 carbon atoms and a fatty acid having 7 to 9 carbon atoms with a branched chain are essential components, and other fatty acids are contained as constituent components as required. That is, the polyol fatty acid ester (A) may contain only two fatty acids as acid constituent components, or may contain three or more fatty acids with different structures as acid constituent components, and the polyol fatty acid ester preferably contains only fatty acids whose carbon atoms adjacent to the carbonyl carbon (α-position carbon atom) are not quaternary carbons as acid constituent components. In the case where the fatty acid constituting the polyol fatty acid ester contains a fatty acid whose α-position carbon atom is a quaternary carbon, there is a tendency that the lubricity becomes insufficient in the presence of difluoromethane when the refrigerant composition contains difluoromethane.

[0059] As the polyol constituting the polyol ester according to the present embodiment, it is preferred to use a polyol having 2 to 6 hydroxyl groups.

[0060] Specific examples of the diols include ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 1,7-heptanediol, 2-methyl-2-propyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol. Specific examples of trivalent or higher alcohols include trimethylolethane, trimethylolpropane, trimethylolbutane, di(trimethylolpropane), tri(trimethylolpropane), pentaerythritol, di(pentaerythritol), tri(pentaerythritol), glycerol, polyglycerol (dimer to trimer of glycerol), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol glycerol condensate, adonitol, arabitol, xylitol, mannitol and other polyols, xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose and other sugars, and partial etherification products thereof. Among these, esters of hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di(trimethylolpropane), tri(trimethylolpropane), pentaerythritol, di(pentaerythritol), and tri(pentaerythritol) are more preferred from the viewpoint of better hydrolysis stability; esters of neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane and pentaerythritol and di(pentaerythritol) are further preferred; neopentyl glycol, trimethylolpropane, pentaerythritol, and di(pentaerythritol) are further preferred; and pentaerythritol, di(pentaerythritol), or a mixed ester of pentaerythritol and di(pentaerythritol) is most preferred from the viewpoint of particularly excellent compatibility with refrigerants and hydrolysis stability.

[0061] Preferred examples of the acid constituent component constituting the polyol fatty acid ester (A) include the following.

[0062] (i) a combination of 1 to 13 selected from butyric acid, 2-methylpropionic acid, valeric acid, 2-methylbutyric acid, 3-methylbutyric acid, 2,2-dimethylpropionic acid, 2-methylvaleric acid, 3-methylvaleric acid, 4-methylvaleric acid, 2,2-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3,3-dimethylbutyric acid and caproic acid and 1 to 13 selected from 2-methylhexanoic acid, 3-methylhexanoic acid, 4-methylhexanoic acid, 5-methylhexanoic acid, 2,2-dimethylvaleric acid, 2,3-dimethylvaleric acid, 2,4-dimethylvaleric acid, 3,3-dimethylvaleric acid, 3,4-dimethylvaleric acid, 4,4-dimethylvaleric acid, 2-ethylvaleric acid, 3-ethylvaleric acid and 2-ethyl-3-methylbutyric acid;

[0063] (ii) one to thirteen selected from butyric acid, 2-methylpropionic acid, valeric acid, 2-methylbutyric acid, 3-methylbutyric acid, 2,2-dimethylpropionic acid, 2-methylvaleric acid, 3-methylvaleric acid, 4-methylvaleric acid, 2,2-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3,3-dimethylbutyric acid and hexanoic acid and one to thirteen selected from 2-methylheptanoic acid, 3-methylheptanoic acid, 4-methylheptanoic acid, 5-methylheptanoic acid, 6-methylheptanoic acid, 2,2-dimethylhexanoic acid, 3,3-dimethylhexanoic acid, 4,4-dimethylhexanoic acid, 5,5-dimethyl A combination of 1 to 25 of hexanoic acid, 2,3-dimethylhexanoic acid, 2,4-dimethylhexanoic acid, 2,5-dimethylhexanoic acid, 3,4-dimethylhexanoic acid, 3,5-dimethylhexanoic acid, 4,5-dimethylhexanoic acid, 2,2,3-trimethylpentanoic acid, 2,3,3-trimethylpentanoic acid, 2,4,4-trimethylpentanoic acid, 3,4,4-trimethylpentanoic acid, 2-ethylhexanoic acid, 3-ethylhexanoic acid, 2-propylpentanoic acid, 2-methyl-2-ethylpentanoic acid, 2-methyl-3-ethylpentanoic acid, and 3-methyl-3-ethylpentanoic acid;

[0064] (iii) 1 to 13 selected from butyric acid, 2-methylpropionic acid, valeric acid, 2-methylbutyric acid, 3-methylbutyric acid, 2,2-dimethylpropionic acid, 2-methylvaleric acid, 3-methylvaleric acid, 4-methylvaleric acid, 2,2-dimethylbutyric acid, 2,3-dimethylbutyric acid, 3,3-dimethylbutyric acid and caproic acid and 2-methyloctanoic acid, 3-methyloctanoic acid, 4-methyloctanoic acid, 5-methyloctanoic acid, 6-methyloctanoic acid, 7-methyloctanoic acid, 8-methyloctanoic acid, 2, 2-dimethylheptanoic acid, 3,3-dimethylheptanoic acid, 4,4-dimethylheptanoic acid, 5,5-dimethylheptanoic acid, 6,6-dimethylheptanoic acid, 2,3-dimethylheptanoic acid, 2,4-dimethylheptanoic acid, 2,5-dimethylheptanoic acid, 2,6-dimethylheptanoic acid, 3,4-dimethylheptanoic acid, 3,5-dimethylheptanoic acid, 3,6-dimethylheptanoic acid, 4,5-dimethylheptanoic acid, 4,6-dimethylheptanoic acid, 2-ethylheptanoic acid, 3-ethylheptanoic acid, 4-ethylheptanoic acid , 5-ethylheptanoic acid, 2-propylhexanoic acid, 3-propylhexanoic acid, 2-butylpentanoic acid, 2,2,3-trimethylhexanoic acid, 2,2,3-trimethylhexanoic acid, 2,2,4-trimethylhexanoic acid, 2,2,5-trimethylhexanoic acid, 2,3,4-trimethylhexanoic acid, 2,3,5-trimethylhexanoic acid, 3,3,4-trimethylhexanoic acid, 3,3,5-trimethylhexanoic acid, 3,5,5-trimethylhexanoic acid, 4,4,5-trimethylhexanoic acid, 4,5,5-trimethyl A combination of 1 to 50 of hexanoic acid, 2,2,3,3-tetramethylvaleric acid, 2,2,3,4-tetramethylvaleric acid, 2,2,4,4-tetramethylvaleric acid, 2,3,4,4-tetramethylvaleric acid, 3,3,4,4-tetramethylvaleric acid, 2,2-diethylvaleric acid, 2,3-diethylvaleric acid, 3,3-diethylvaleric acid, 2-ethyl-2,3,3-trimethylbutanoic acid, 3-ethyl-2,2,3-trimethylbutanoic acid, and 2,2-diisopropylpropionic acid.

[0065] Further preferred examples of the acid constituent component constituting the polyol fatty acid ester include the following.

[0066] (i) a combination of 2-methylpropionic acid and 1 to 13 selected from the group consisting of 2-methylhexanoic acid, 3-methylhexanoic acid, 4-methylhexanoic acid, 5-methylhexanoic acid, 2,2-dimethylvaleric acid, 2,3-dimethylvaleric acid, 2,4-dimethylvaleric acid, 3,3-dimethylvaleric acid, 3,4-dimethylvaleric acid, 4,4-dimethylvaleric acid, 2-ethylvaleric acid, 3-ethylvaleric acid and 2-ethyl-3-methylbutyric acid;

[0067] (ii) a combination of 2-methylpropionic acid and 1 to 25 selected from the group consisting of 2-methylheptanoic acid, 3-methylheptanoic acid, 4-methylheptanoic acid, 5-methylheptanoic acid, 6-methylheptanoic acid, 2,2-dimethylhexanoic acid, 3,3-dimethylhexanoic acid, 4,4-dimethylhexanoic acid, 5,5-dimethylhexanoic acid, 2,3-dimethylhexanoic acid, 2,4-dimethylhexanoic acid, 2,5-dimethylhexanoic acid, 3,4-dimethylhexanoic acid, 3,5-dimethylhexanoic acid, 4,5-dimethylhexanoic acid, 2,2,3-trimethylpentanoic acid, 2,3,3-trimethylpentanoic acid, 2,4,4-trimethylpentanoic acid, 3,4,4-trimethylpentanoic acid, 2-ethylhexanoic acid, 3-ethylhexanoic acid, 2-propylpentanoic acid, 2-methyl-2-ethylpentanoic acid, 2-methyl-3-ethylpentanoic acid, and 3-methyl-3-ethylpentanoic acid;

[0068] (iii) 2-methylpropionic acid and a diisocyanate selected from the group consisting of 2-methyloctanoic acid, 3-methyloctanoic acid, 4-methyloctanoic acid, 5-methyloctanoic acid, 6-methyloctanoic acid, 7-methyloctanoic acid, 8-methyloctanoic acid, 2,2-dimethylheptanoic acid, 3,3-dimethylheptanoic acid, 4,4-dimethylheptanoic acid, 5,5-dimethylheptanoic acid, 6,6-dimethylheptanoic acid, 2,3-dimethylheptanoic acid, 2,4-dimethylheptanoic acid, 2,5-dimethylheptanoic acid, 2,6-dimethylheptanoic acid, 3,4-dimethylheptanoic acid, 3,5-dimethylheptanoic acid, 3,6-dimethylheptanoic acid, 4,5-dimethylheptanoic acid, 4,6-dimethylheptanoic acid, 2-ethylheptanoic acid, 3-ethylheptanoic acid, 4-ethylheptanoic acid, 5-ethylheptanoic acid, 2-propylhexanoic acid, 3-propylhexanoic acid, 2-butylpentanoic acid, 2,2,3-trimethylhexanoic acid, 2,2,3 -trimethylhexanoic acid, 2,2,4-trimethylhexanoic acid, 2,2,5-trimethylhexanoic acid, 2,3,4-trimethylhexanoic acid, 2,3,5-trimethylhexanoic acid, 3,3,4-trimethylhexanoic acid, 3,3,5-trimethylhexanoic acid, 3,5,5-trimethylhexanoic acid, 4,4,5-trimethylhexanoic acid, 4,5,5-trimethylhexanoic acid, 2,2,3,3-tetramethylpentanoic acid, 2,2,3, A combination of 1 to 50 of 4-tetramethylvaleric acid, 2,2,4,4-tetramethylvaleric acid, 2,3,4,4-tetramethylvaleric acid, 3,3,4,4-tetramethylvaleric acid, 2,2-diethylvaleric acid, 2,3-diethylvaleric acid, 3,3-diethylvaleric acid, 2-ethyl-2,3,3-trimethylbutanoic acid, 3-ethyl-2,2,3-trimethylbutanoic acid and 2,2-diisopropylpropionic acid.

[0069] Based on the total amount of refrigeration oil, the content of the above-mentioned polyol fatty acid ester (A) is 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and further preferably 75% by mass or more. As described later, the refrigeration oil involved in the present embodiment may contain a lubricating base oil or additive other than the polyol fatty acid ester (A), but when the polyol fatty acid ester (A) is less than 50% by mass, it is impossible to have both the necessary viscosity and compatibility at a high level.

[0070] In the refrigeration oil involved in the present embodiment, polyol fatty acid ester (A) is mainly used as a base oil. As the base oil of the refrigeration oil involved in the present embodiment, polyol fatty acid ester (A) can be used alone (i.e., the content of polyol fatty acid ester (A) is 100% by mass), but in addition, a base oil other than polyol fatty acid ester (A) can be further contained to the extent that its excellent performance is not impaired. As base oils other than polyol fatty acid ester (A), hydrocarbon oils such as mineral oil, olefin polymer, alkyl diphenyl alkane, alkyl naphthalene, alkyl benzene, etc. can be listed; esters such as polyol esters, complex esters, alicyclic dicarboxylates, polyethylene glycol, polyvinyl ether, ketone, polyphenylene ether, silicone, polysiloxane, perfluoroether, etc. containing oxygen (hereinafter sometimes referred to as "other oxygen-containing synthetic oils"), etc.

[0071] As the synthetic oil containing oxygen, among the above, esters other than the polyol fatty acid ester (A), polyethylene glycol, and polyvinyl ether are preferred, and polyol esters other than the polyol fatty acid ester (A) are particularly preferred. As polyol esters other than the polyol fatty acid ester (A), esters of polyols and fatty acids such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, pentaerythritol, and dipentaerythritol can be cited, and esters of neopentyl glycol and fatty acids, esters of pentaerythritol and fatty acids, and esters of dipentaerythritol and fatty acids are particularly preferred.

[0072] The neopentyl glycol ester is preferably an ester of neopentyl glycol and a fatty acid having 5 to 9 carbon atoms. Specific examples of such neopentyl glycol esters include neopentyl glycol di(3,5,5-trimethylhexanoate), neopentyl glycol di(2-ethylhexanoate), neopentyl glycol di(2-methylhexanoate), neopentyl glycol di(2-ethylvalerate), esters of neopentyl glycol with 2-methylhexanoic acid and 2-ethylvaleric acid, esters of neopentyl glycol with 3-methylhexanoic acid and 5-methylhexanoic acid, esters of neopentyl glycol with 2-methylhexanoic acid and 2-ethylhexanoic acid, esters of neopentyl glycol with 3,5-dimethylhexanoic acid, 4,5-dimethylhexanoic acid and 3,4-dimethylhexanoic acid, neopentyl glycol divalerate, neopentyl glycol di(2-ethylbutyrate), neopentyl glycol di(2-methylvalerate), neopentyl glycol di(2-methylbutyrate), and neopentyl glycol di(3-methylbutyrate).

[0073] As the pentaerythritol ester, an ester of pentaerythritol and a fatty acid having 5 to 9 carbon atoms is preferred. Specific examples of such pentaerythritol ester include esters of pentaerythritol and one or more fatty acids selected from valeric acid, 2-methylbutyric acid, 3-methylbutyric acid, hexanoic acid, 2-methylvaleric acid, 2-ethylbutyric acid, 2-ethylvaleric acid, 2-methylhexanoic acid, 3,5,5-trimethylhexanoic acid and 2-ethylhexanoic acid.

[0074] As the dipentaerythritol ester, an ester of dipentaerythritol and a fatty acid having 5 to 9 carbon atoms is preferred. Specific examples of such dipentaerythritol ester include esters of dipentaerythritol and one or more fatty acids selected from valeric acid, 2-methylbutyric acid, 3-methylbutyric acid, hexanoic acid, 2-methylvaleric acid, 2-ethylbutyric acid, 2-ethylvaleric acid, 2-methylhexanoic acid, 3,5,5-trimethylhexanoic acid and 2-ethylhexanoic acid.

[0075] In the case where the refrigerating machine oil involved in the present embodiment contains oxygen-containing synthetic oil other than polyol fatty acid ester (A), there is no particular restriction on the content of oxygen-containing synthetic oil other than polyol fatty acid ester (A) as long as it does not damage the excellent lubricity and compatibility of the refrigerating machine oil involved in the present embodiment. In the case of mixing polyol esters other than polyol fatty acid ester (A), based on the total amount of refrigerating machine oil, it is preferably less than 50% by mass, more preferably 45% by mass or less, further preferably 40% by mass or less, further preferably 35% by mass or less, further preferably 30% by mass or less, and most preferably 25% by mass or less; in the case of mixing oxygen-containing synthetic oil other than polyol ester, based on the total amount of refrigerating machine oil, it is preferably less than 50% by mass, more preferably 40% by mass or less, and further preferably 30% by mass or less. When the amount of polyol esters other than pentaerythritol fatty acid ester or other oxygen-containing synthetic oil is too much, the above-mentioned effect cannot be fully obtained.

[0076] Among them, the polyol ester other than the polyol fatty acid ester (A) may be a partial ester in which a part of the hydroxyl groups of the polyol are not esterified but the hydroxyl groups still remain, or a complete ester in which all the hydroxyl groups are esterified, or a mixture of a partial ester and a complete ester, and the hydroxyl value is preferably 10 mgKOH / g or less, more preferably 5 mgKOH / g or less, and most preferably 3 mgKOH / g or less.

[0077] When the refrigeration oil and the working fluid for a refrigeration machine involved in this embodiment contain a polyol ester other than the polyol fatty acid ester (A), the polyol ester may contain a polyol ester composed of a single structure or a mixture of two or more polyol esters with different structures.

[0078] In addition, the polyol ester other than the polyol fatty acid ester (A) may be any of esters of one fatty acid and one polyol, esters of two or more fatty acids and one polyol, esters of one fatty acid and two or more polyols, and esters of two or more fatty acids and two or more polyols.

[0079] The refrigeration oil involved in the present embodiment can be composed of only polyol fatty acid ester (A), or can be composed of polyol fatty acid ester (A) and other base oils, and can further contain various additives described later. In addition, in the working fluid for refrigerators involved in the present embodiment, various additives can be further contained. Among them, in the following description, the content of additives is expressed based on the total amount of refrigeration oil, and the content of these components in the working fluid for refrigerators is preferably selected so that it is within the preferred range described later when the total amount of refrigeration oil is used as a benchmark.

[0080] In order to further improve the wear resistance and load resistance of the refrigerator oil and refrigerator working fluid involved in this embodiment, at least one phosphorus compound selected from phosphate esters, acidic phosphate esters, thiophosphate esters, amine salts of acidic phosphate esters, chlorinated phosphate esters and phosphites can be added. These phosphorus compounds are esters of phosphoric acid or phosphorous acid with alkanols, polyether alcohols or derivatives thereof.

[0081] Specifically, for example, as the phosphoric acid ester, there can be mentioned tributyl phosphate, tripentyl phosphate, trihexyl phosphate, triheptyl phosphate, trioctyl phosphate, trinonyl phosphate, tridecyl phosphate, triundecyl phosphate, tridodecyl phosphate, tritridecyl phosphate, tritetradecyl phosphate, tripentadecyl phosphate, trihexadecyl phosphate, triheptadecyl phosphate, trioctadecyl phosphate, trioleyl phosphate, triphenyl phosphate, tricresyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, and dicresyl diphenyl phosphate.

[0082] Examples of the acidic phosphate ester include monobutyl acid phosphate, monopentyl acid phosphate, monohexyl acid phosphate, monoheptyl acid phosphate, monooctyl acid phosphate, monononyl acid phosphate, monodecyl acid phosphate, monoundecyl acid phosphate, monododecyl acid phosphate, monotridecyl acid phosphate, monotetradecyl acid phosphate, monopentadecyl acid phosphate, monohexadecyl acid phosphate, monoheptadecyl acid phosphate, monooctadecyl acid phosphate, monooleyl acid phosphate, dibutyl ... phosphate, dipentyl acid phosphate, dihexyl acid phosphate, diheptyl acid phosphate, dioctyl acid phosphate, dinonyl acid phosphate, didecyl acid phosphate, diundecyl acid phosphate, didodecyl acid phosphate, didodecyl acid phosphate, didedecyl acid phosphate, didetradecyl acid phosphate, didopentadecyl acid phosphate, didhexadecyl acid phosphate, didephedecyl acid phosphate, dideoctadecyl acid phosphate, dioleyl acid phosphate, etc.

[0083] Examples of the phosphorothioate include tributyl phosphorothioate, tripentyl phosphorothioate, trihexyl phosphorothioate, triheptyl phosphorothioate, trioctyl phosphorothioate, trinonyl phosphorothioate, tridecyl phosphorothioate, triundecyl phosphorothioate, tridodecyl phosphorothioate, tritridecyl phosphorothioate, tritetradecyl phosphorothioate, tripentadecyl phosphorothioate, trihexadecyl phosphorothioate, triheptadecyl phosphorothioate, trioctadecyl phosphorothioate, trioleyl phosphorothioate, triphenyl phosphorothioate, tricresyl phosphorothioate, trixylyl phosphorothioate, cresyl diphenyl phosphorothioate, and xylyl diphenyl phosphorothioate.

[0084] Examples of the amine salt of the acidic phosphoric acid ester include amine salts of the acidic phosphoric acid ester and a primary, secondary or tertiary amine having a linear or branched alkyl group having 1 to 24 carbon atoms, preferably 5 to 18 carbon atoms.

[0085] Examples of the amines constituting the amine salts of the acidic phosphates include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, oleylamine, tetracosylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, diundecylamine, didodecylamine, ditridecylamine, ditetradecylamine, The amine may be a salt of an amine such as di(pentadecyl)amine, di(hexadecyl)amine, di(heptadecyl)amine, di(octadecyl)amine, dioleylamine, di(tetracosyl)amine, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, triundecylamine, tridodecylamine, tritridecylamine, tritetradecylamine, tripentadecylamine, trihexadecylamine, triheptadecylamine, trioctadecylamine, trioleylamine, and tritetracosylamine. The amine may be a single compound or a mixture of two or more compounds.

[0086] As chlorinated phosphate, tris (dichloropropyl) phosphate, tris (chloroethyl) phosphate, tris (chlorophenyl) phosphate, polyoxyalkylene bis [di (chloroalkyl)] phosphate, etc. can be listed. As phosphite, dibutyl phosphite, dipentyl phosphite, dihexyl phosphite, diheptyl phosphite, dioctyl phosphite, dinonyl phosphite, didecyl phosphite, diundecyl phosphite, didodecyl phosphite, dioleyl phosphite, diphenyl phosphite, ditolyl phosphite, tributyl phosphite, tripentyl phosphite, trihexyl phosphite, triheptyl phosphite, trioctyl phosphite, trinonyl phosphite, tridecyl phosphite, triundecyl phosphite, tridodecyl phosphite, trioleyl phosphite, triphenyl phosphite, tricresyl phosphite, etc. can be listed. In addition, their mixture can also be used.

[0087] When the refrigeration oil and the working fluid for refrigerators involved in the present embodiment contain the above-mentioned phosphorus compound, the content of the phosphorus compound is not particularly limited. Based on the total amount of the refrigeration oil (based on the total amount of the base oil and all the additives), it is preferably 0.01 to 5.0% by mass, and more preferably 0.02 to 3.0% by mass. Among them, the above-mentioned phosphorus compound can be used alone or in combination of two or more.

[0088] In addition, the refrigerator oil and refrigerator working fluid according to the present embodiment may be added with a terpene compound to further improve its thermal and chemical stability. The "terpene compound" referred to in the present invention refers to a compound obtained by polymerizing isoprene and its derivatives, and preferably dimers to octamers of isoprene are used. Terpene compounds include monoterpenes such as geraniol, nerol, linalool, citral (including geranial), citronellol, menthol, limonene, pinoleol, carvone, ionone, thujone, camphor, and borneol; sesquiterpenes such as farnesene, farnesol, nerolidol, juvenile hormone, humulene, caryophyllene, elemene, cadinol, cadinene, and hydroxymazantoxin; diterpenes such as geranylgeraniol, phytol, abietic acid, pinadiene, daphnetoxin, taxol, and pimaric acid; diterpenes such as geranylfarnesene; triterpenes such as squalene, limonin, camellia sapogenin, hopane, and lanosterol; and tetraterpenes such as carotenoids.

[0089] Among these terpene compounds, monoterpenes, sesquiterpenes, and diterpenes are preferred, sesquiterpenes are more preferred, and α-farnesene (3,7,11-trimethyldodeca-1,3,6,10-tetraene) and / or β-farnesene (7,11-dimethyl-3-methylenedodeca-1,6,10-triene) are particularly preferred. In the present invention, the terpene compounds may be used alone or in combination of two or more.

[0090] The content of the terpene compound in the refrigerator oil involved in the present embodiment is not particularly limited, and is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, and further preferably 0.05 to 3% by mass, based on the total amount of the refrigerator oil. When the content of the terpene compound is less than 0.001% by mass, there is a tendency that the effect of improving the thermal and chemical stability is insufficient, and when it exceeds 10% by mass, there is a tendency that the lubricity is insufficient. In addition, it is preferred that the content of the terpene compound in the refrigerator working fluid involved in the present embodiment be selected so that it is within the above-mentioned preferred range based on the total amount of the refrigerator oil.

[0091] In addition, in order to further improve the thermal and chemical stability of the refrigeration oil and the working fluid for the refrigeration machine involved in this embodiment, at least one epoxy compound selected from phenyl glycidyl ether type epoxy compounds, alkyl glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, allyl oxirane (Oxirane) compounds, alkyl oxirane compounds, alicyclic epoxy compounds, epoxidized fatty acid monoesters and epoxidized vegetable oils may be contained.

[0092] As the phenyl glycidyl ether type epoxy compound, specifically, phenyl glycidyl ether or alkylphenyl glycidyl ether can be exemplified. The alkylphenyl glycidyl ether mentioned here can be exemplified by alkylphenyl glycidyl ethers having 1 to 3 alkyl groups with 1 to 13 carbon atoms, and among them, as preferred examples, alkylphenyl glycidyl ethers having 1 alkyl group with 4 to 10 carbon atoms can be exemplified, such as n-butylphenyl glycidyl ether, isobutylphenyl glycidyl ether, sec-butylphenyl glycidyl ether, tert-butylphenyl glycidyl ether, pentylphenyl glycidyl ether, hexylphenyl glycidyl ether, heptylphenyl glycidyl ether, octylphenyl glycidyl ether, nonylphenyl glycidyl ether, decylphenyl glycidyl ether, etc.

[0093] Specific examples of the alkyl glycidyl ether type epoxy compound include decyl glycidyl ether, undecyl glycidyl ether, dodecyl glycidyl ether, tridecyl glycidyl ether, tetradecyl glycidyl ether, 2-ethylhexyl glycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, 1,6-hexanediol diglycidyl ether, sorbitol polyglycidyl ether, polyalkylene glycol monoglycidyl ether, and polyalkylene glycol diglycidyl ether.

[0094] Specific examples of the glycidyl ester epoxy compound include phenyl glycidyl ester, alkyl glycidyl ester, alkenyl glycidyl ester, and preferred examples include glycidyl-2,2-dimethyloctanoate, glycidyl benzoate, glycidyl acrylate, and glycidyl methacrylate.

[0095] Specific examples of the allyloxirane compound include 1,2-epoxystyrene and alkyl-1,2-epoxystyrene.

[0096] Specific examples of the alkyl oxirane compound include 1,2-butylene oxide, 1,2-pentene oxide, 1,2-hexene oxide, 1,2-heptene oxide, 1,2-octane oxide, 1,2-nonane oxide, 1,2-decane oxide, 1,2-undecane oxide, 1,2-dodecane oxide, 1,2-tridecane oxide, 1,2-tetradecane oxide, 1,2-pentadecane oxide, 1,2-hexadecane oxide, 1,2-heptadecane oxide, 1,1,2-octadecane oxide, 2-nonadecane oxide, and 1,2-eicosane oxide.

[0097] Specific examples of the alicyclic epoxy compound include 1,2-epoxycyclohexane, 1,2-epoxycyclopentane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis(3,4-epoxycyclohexylmethyl)adipate, exo-2,3-epoxynorbornane, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, 2-(7-oxabicyclo[4.1.0]hept-3-yl)-spiro(1,3-dioxane-5,3'-[7]oxabicyclo[4.1.0]heptane, 4-(1'-methyloxiranyl)-1,2-epoxy-2-methylcyclohexane, and 4-oxiranyl-1,2-epoxycyclohexane.

[0098] Specific examples of the epoxidized fatty acid monoester include esters of epoxidized fatty acids having 12 to 20 carbon atoms and alcohols, phenols, or alkylphenols having 1 to 8 carbon atoms. In particular, butyl, hexyl, benzyl, cyclohexyl, methoxyethyl, octyl, phenyl, and butylphenyl epoxy stearates are preferably used.

[0099] Specific examples of the epoxidized vegetable oil include epoxides of vegetable oils such as soybean oil, linseed oil, and cottonseed oil.

[0100] Among these epoxy compounds, preferred are phenyl glycidyl ether type epoxy compounds, alkyl glycidyl ether type epoxy compounds, glycidyl ester type epoxy compounds, and alicyclic epoxy compounds.

[0101] When the refrigerating machine oil and the working fluid for a refrigerating machine according to the present embodiment contain the above-mentioned epoxy compound, the content of the epoxy compound is not particularly limited, but is preferably 0.01 to 5.0% by mass, more preferably 0.1 to 3.0% by mass, based on the total amount of the refrigerating machine oil. The above-mentioned epoxy compound may be used alone or in combination of two or more.

[0102] Among them, the kinematic viscosity of the refrigerating machine oil containing the polyol fatty acid ester (A) at 40° C. is preferably 20 to 80 mm 2 / s, more preferably 25 to 75 mm 2 / s, preferably 30 to 70 mm 2 / s. In addition, the kinematic viscosity at 100°C may preferably be 2 to 20 mm 2 / s, more preferably 3 to 10 mm 2 When the kinematic viscosity is above the lower limit, the viscosity required for refrigerating machine oil can be easily ensured. On the other hand, when the kinematic viscosity is below the upper limit, when difluoromethane is contained as a refrigerant composition, the compatibility with difluoromethane can be made sufficient.

[0103] The volume resistivity of the refrigerating machine oil containing the polyol fatty acid ester (A) is not particularly limited, but is preferably 1.0×10 12 Ω·cm or more, more preferably 1.0×10 13 Ω·cm or more, most preferably 1.0×10 14 Ω·cm or more. In particular, when used in a sealed refrigerator, there is a tendency to require high electrical insulation. The volume resistivity refers to the value measured at 25°C based on JIS C 2101 "Test methods for electrical insulating oils".

[0104] In addition, the water content of the refrigeration oil containing the polyol fatty acid ester (A) is not particularly limited, and can be preferably 200 ppm or less, more preferably 100 ppm or less, and most preferably 50 ppm or less, based on the total amount of the refrigeration oil. In particular, when used for a sealed refrigerator, the water content is required to be low from the perspective of the thermal and chemical stability of the refrigeration oil and the influence on the electrical insulation.

[0105] In addition, the acid value of the refrigeration oil containing the polyol fatty acid ester (A) is not particularly limited, but in order to prevent corrosion of metals used in refrigerators or pipes, it can be preferably 0.1 mgKOH / g or less, and more preferably 0.05 mgKOH / g or less. In the present invention, the acid value refers to the acid value measured based on JIS K 2501 "Petroleum products and lubricating oils-Neutralization value test method".

[0106] In addition, the ash content of the refrigeration oil containing polyol fatty acid ester (A) is not particularly limited, but in order to improve the thermal and chemical stability of the refrigeration oil and inhibit the generation of sludge, etc., it can be preferably 100 ppm or less, and more preferably 50 ppm or less. Among them, the ash content refers to the ash value measured based on JIS K 2272 "Determination of ash content of crude oil and petroleum products and sulfated ash content".

[0107] (Compound ester oil)

[0108] The complex ester oil is an ester of a fatty acid, a dibasic acid, a monohydric alcohol, and a polyhydric alcohol. As the fatty acid, the dibasic acid, the monohydric alcohol, and the polyhydric alcohol, the same ones as those described above can be used.

[0109] Examples of the fatty acid include the fatty acids listed above as the fatty acids of the polyol ester.

[0110] Examples of the dibasic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, phthalic acid, isophthalic acid, and terephthalic acid.

[0111] Examples of the polyol include the polyols listed above as the polyols of the polyol esters. Complex esters are esters of these fatty acids, dibasic acids, and polyols, and may be esters of a single component or composed of a plurality of components.

[0112] (Polyol carbonate oil)

[0113] Polyol carbonate oils are esters of carbonic acid and polyols.

[0114] Examples of the polyol include the same diols and polyols as those mentioned above.

[0115] In addition, the polyol carbonate oil may be a ring-opening polymer of a cyclic alkylene carbonate.

[0116] (2-1-2) Ether Refrigeration Oil

[0117] Examples of the ether-based refrigeration oil include polyvinyl ether oil and polyoxyalkylene oil.

[0118] (Polyvinyl ether oil)

[0119] Examples of the polyvinyl ether oil include polymers of vinyl ether monomers, copolymers of vinyl ether monomers and hydrocarbon monomers having olefinic double bonds, and copolymers of monomers having olefinic double bonds and polyoxyalkylene chains and vinyl ether monomers.

[0120] The carbon / oxygen molar ratio of the polyvinyl ether oil is preferably 2 to 7.5, more preferably 2.5 to 5.8. When the carbon / oxygen molar ratio is lower than this range, the hygroscopicity becomes high; when it is higher than this range, the compatibility decreases. In addition, the weight average molecular weight of the polyvinyl ether is preferably 200 to 3000, more preferably 500 to 1500.

[0121] The pour point of the polyvinyl ether oil is preferably -30°C or lower. The surface tension of the polyvinyl ether oil at 20°C is preferably 0.02 N / m or more and 0.04 N / m or less. The density of the polyvinyl ether oil at 15°C is preferably 0.8 g / cm 3 Above 1.8g / cm 3 The saturated water content of the polyvinyl ether oil at a temperature of 30° C. and a relative humidity of 90% is preferably 2000 ppm or more.

[0122] The refrigeration oil may contain polyvinyl ether as a main component. When the refrigerant contains HFO-1234yf, the polyvinyl ether as the main component of the refrigeration oil is compatible with the HFO-1234yf, and the kinematic viscosity of the refrigeration oil at 40°C is 400 mm 2 / s or less, HFO-1234yf dissolves in the refrigeration oil to a certain extent. In addition, when the pour point of the refrigeration oil is below -30°C, it is easy to ensure the fluidity of the refrigeration oil even in the refrigerant circuit where the refrigerant composition or the refrigeration oil is at a low temperature. In addition, when the surface tension of the refrigeration oil at 20°C is below 0.04N / m, the refrigeration oil ejected from the compressor is not likely to become large oil droplets that are difficult to be pushed and flowed by the refrigerant composition. Therefore, the refrigeration oil ejected from the compressor is easily dissolved in HFO-1234yf and returns to the compressor together with HFO-1234yf.

[0123] In addition, the kinematic viscosity of refrigeration oil at 40°C is 30 mm 2 / s or more, it is possible to prevent the kinematic viscosity from being too low and the oil film strength from becoming insufficient, and it is easy to ensure lubrication performance. In addition, when the surface tension of the refrigeration oil at 20°C is 0.02N / m or more, it is not easy to form small oil droplets in the gas refrigerant in the compressor, and it is possible to prevent the refrigeration oil from being ejected from the compressor in large quantities. Therefore, it is easy to ensure a sufficient storage amount of refrigeration oil in the compressor.

[0124] In addition, when the saturated water content of the refrigeration oil is 2000 ppm or more at a temperature of 30°C and a relative humidity of 90%, the hygroscopicity of the refrigeration oil can be made higher. Thus, when the refrigerant contains HFO-1234yf, the refrigeration oil can be used to capture the water in the HFO-1234yf to a certain extent. HFO-1234yf has a molecular structure that is easily deteriorated / degraded by the influence of the contained water. Therefore, by utilizing the hygroscopic effect of the refrigeration oil, such degradation can be suppressed.

[0125] Further, in the case where a sealing portion or sliding portion that can contact the refrigerant circulating in the refrigerant circuit is provided with a prescribed resin functional component, and the resin functional component is composed of any of polytetrafluoroethylene, polyphenylene sulfide, phenolic resin, polyamide resin, chloroprene rubber, silicone rubber, hydrogenated nitrile rubber, fluorine-containing rubber, and chloroether rubber, the aniline point of the refrigeration oil is preferably set to its numerical range in consideration of the adaptability to the resin functional component. By setting the aniline point in this way, for example, the adaptability of the bearing constituting the resin functional component and the refrigeration oil is improved. Specifically, when the aniline point is too small, the refrigeration oil is easy to penetrate the bearing, etc., and the bearing, etc. is easy to swell. On the other hand, when the aniline point is too large, the refrigeration oil is difficult to penetrate the bearing, etc., and the bearing, etc. is easy to shrink. Therefore, by making the aniline point of the refrigeration oil a prescribed numerical range, the swelling / shrinkage deformation of the bearing, etc. can be prevented. Here, for example, when swelling / shrinkage deformation occurs in each bearing, etc., the gap (interval) of the sliding portion cannot be maintained at a desired length. As a result, the sliding resistance may increase or the rigidity of the sliding portion may decrease. However, by setting the aniline point of the refrigeration oil to a predetermined numerical range as described above, the swelling / shrinkage deformation of the bearing and the like can be suppressed, thereby avoiding such inconvenience.

[0126] The vinyl ether monomer may be used alone or in combination of two or more thereof. Examples of hydrocarbon monomers having olefinic double bonds include ethylene, propylene, various butenes, various pentenes, various hexenes, various heptenes, various octenes, diisobutylene, triisobutylene, styrene, α-methylstyrene, and various alkyl-substituted styrenes. The hydrocarbon monomers having olefinic double bonds may be used alone or in combination of two or more thereof.

[0127] The polyvinyl ether copolymer may be a block copolymer or a random copolymer. The polyvinyl ether oil may be used alone or in combination of two or more.

[0128] The polyvinyl ether oil preferably used has a structural unit represented by the following general formula (1).

[0129]

[0130] (Where R 1 , R 2 and R 3 may be the same or different, and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms, 4 represents a divalent hydrocarbon group having 1 to 10 carbon atoms or a divalent ether bond-containing oxygen hydrocarbon group having 2 to 20 carbon atoms, R 5 represents a hydrocarbon group having 1 to 20 carbon atoms, m represents a number such that the average value of m in the above polyvinyl ether is 0 to 10, and R 1 ~R 5The same or different R may be present in each structural unit. When m is 2 or more in one structural unit, the multiple R 4 O can be the same or different.)

[0131] In the above general formula (1), R 1 , R 2 and R 3 Preferably, at least one of them is a hydrogen atom, and particularly preferably all of them are hydrogen atoms. m in the general formula (1) is preferably 0 to 10, particularly preferably 0 to 5, and further preferably 0. R in the general formula (1) 5 represents a hydrocarbon group having 1 to 20 carbon atoms, and specifically represents: alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, various pentyls, various hexyls, various heptyls, and various octyl groups; cycloalkyl groups such as cyclopentyl, cyclohexyl, various methylcyclohexyls, various ethylcyclohexyls, and various dimethylcyclohexyls; aryl groups such as phenyl, various methylphenyls, various ethylphenyls, and various dimethylphenyls; and aralkyl groups such as benzyl, various phenylethyls, and various methylbenzyls. Among the alkyl, cycloalkyl, phenyl, aryl, and aralkyl groups, alkyl groups are preferred, and alkyl groups having 1 to 5 carbon atoms are particularly preferred. Among the polyvinyl ether oils, those having R 5 Polyvinyl ether oil with an alkyl group having 1 or 2 carbon atoms: R 5 The polyvinyl ether oil having an alkyl group having 3 or 4 carbon atoms is contained in a ratio of 40%:60% to 100%:0%.

[0132] The polyvinyl ether oil of the present embodiment may be a homopolymer having the same structural unit represented by the general formula (1), or may be a copolymer composed of two or more structural units. The copolymer may be a block copolymer or a random copolymer.

[0133] The polyvinyl ether oil according to the present embodiment may be composed only of the structural unit represented by the above general formula (1), or may be a copolymer further comprising a structural unit represented by the following general formula (2). In this case, the copolymer may be a block copolymer or a random copolymer.

[0134]

[0135] (Where R 6 ~R 9 They may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

[0136] Examples of the vinyl ether monomer include compounds represented by the following general formula (3).

[0137]

[0138] (Where R 1 , R 2 , R 3 , R 4 , R 5 and m represent the same as R in the general formula (1) 1 , R 2 , R 3 , R 4 , R 5 Same definition as m.)

[0139] There are various compounds corresponding to the above-mentioned polyvinyl ether compounds, for example, vinyl methyl ether, vinyl ethyl ether, vinyl n-propyl ether, vinyl isopropyl ether, vinyl n-butyl ether, vinyl isobutyl ether, vinyl sec-butyl ether, vinyl tert-butyl ether, vinyl n-pentyl ether, vinyl n-hexyl ether, vinyl-2-methoxyethyl ether, vinyl-2-ethoxyethyl ether, vinyl-2-methoxy-1-methylethyl ether, vinyl-2-methoxy-propyl ether, vinyl-3,6-dioxepane ether, vinyl-3,6,9-trioxydecyl ether, vinyl-1,4-dimethyl-3,6-dioxyheptyl ether, vinyl-1,4,7-trimethyl-3,6,9-trioxydecyl ether, vinyl-2,6-dioxy-4-heptyl ether, vinyl-2,6,9-trioxy-4-decyl ether, 1-methoxypropylene, 1-ethoxypropylene, 1-n-propoxypropylene, 1-isopropoxypropylene, 1-n-butoxypropylene, 1-isobutoxypropylene, 1-sec-butoxypropylene, 1-tert-butoxypropylene; 2- methoxypropylene, 2-ethoxypropylene, 2-n-propoxypropylene, 2-isopropoxypropylene, 2-n-butoxypropylene, 2-isobutoxypropylene, 2-sec-butoxypropylene, 2-tert-butoxypropylene, 1-methoxy-1-butene, 1-ethoxy-1-butene, 1-n-propoxy-1-butene, 1-isopropoxy-1-butene, 1-n-butoxy-1-butene, 1-isobutoxy-1-butene, 1-sec-butoxy-1-butene, 1-tert-butoxy-1-butene, 2-methoxy-1-butene, 2- Ethoxy-1-butene, 2-n-propoxy-1-butene, 2-isopropoxy-1-butene, 2-n-butoxy-1-butene, 2-isobutoxy-1-butene, 2-sec-butoxy-1-butene, 2-tert-butoxy-1-butene, 2-methoxy-2-butene, 2-ethoxy-2-butene, 2-n-propoxy-2-butene, 2-isopropoxy-2-butene, 2-n-butoxy-2-butene, 2-isobutoxy-2-butene, 2-sec-butoxy-2-butene, 2-tert-butoxy-2-butene, etc. These vinyl ether monomers can be produced by known methods.

[0140] The polyvinyl ether compound having the structural unit represented by the general formula (1) can be converted to a desired structure at its terminal by the method described in the present invention or by a known method. Examples of the group to be converted include saturated hydrocarbons, ethers, alcohols, ketones, amides, and nitriles.

[0141] The polyvinyl ether-based compound preferably has the following terminal structure.

[0142]

[0143] (Where R 11 , R 21 and R 31 They may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. 41 represents a divalent hydrocarbon group having 1 to 10 carbon atoms or a divalent ether bond-containing oxygen hydrocarbon group having 2 to 20 carbon atoms, R 51 represents a hydrocarbon group having 1 to 20 carbon atoms, and m represents a number such that the average value of m in the polyvinyl ether is 0 to 10. When m is 2 or more, a plurality of R 41 O can be the same or different.)

[0144]

[0145] (Where R 61 , R 71 , R 81 and R 91 They may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

[0146]

[0147] (Where R 12 , R 22 and R 32 They may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. 42 represents a divalent hydrocarbon group having 1 to 10 carbon atoms or a divalent ether bond-containing oxygen hydrocarbon group having 2 to 20 carbon atoms, R 52 represents a hydrocarbon group having 1 to 20 carbon atoms, and m represents a number such that the average value of m in the polyvinyl ether is 0 to 10. When m is 2 or more, a plurality of R 42 O can be the same or different.)

[0148]

[0149] (Where R 62 , R 72 , R 82 and R 92They may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms.

[0150]

[0151] (Where R 13 , R 23 and R 33 They may be the same or different and each represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms.

[0152] The polyvinyl ether oil in this embodiment can be produced by subjecting the above-mentioned monomers to free radical polymerization, cationic polymerization, radiation polymerization, etc. After the polymerization reaction is completed, conventional separation and purification methods are carried out as necessary to obtain the target polyvinyl ether compound having a structural unit represented by the general formula (1).

[0153] (Polyoxyalkylene oil)

[0154] Examples of polyoxyalkylene oils include polyoxyalkylene compounds obtained by a method of polymerizing alkylene oxides having 2 to 4 carbon atoms (ethylene oxide, propylene oxide, etc.) using water or a hydroxyl-containing compound as an initiator. In addition, compounds obtained by etherification or esterification of the hydroxyl group of the polyoxyalkylene compound may also be used. The oxyalkylene units in the polyoxyalkylene oil may be the same in one molecule, or may contain two or more oxyalkylene units. Preferably, at least oxypropylene units are contained in one molecule.

[0155] Specific examples of the polyoxyalkylene oil include compounds represented by the following general formula (9).

[0156] R 101 -[(OR 102 ) k -OR 103 ] l …(9)

[0157] (Where R 101 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an acyl group having 2 to 10 carbon atoms, or an aliphatic hydrocarbon group having 1 to 10 carbon atoms and having 2 to 6 bonding parts, and R 102 represents an alkylene group having 2 to 4 carbon atoms, R 103 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an acyl group having 2 to 10 carbon atoms, l represents an integer of 1 to 6, and k represents a number whose average value of k×1 is 6 to 80.

[0158] In the above general formula (9), R 101 , R 103The alkyl group in the above-mentioned group may be any of a straight chain, a branched chain, or a cyclic group. Specific examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, various decyl groups, cyclopentyl groups, and cyclohexyl groups. When the number of carbon atoms in the alkyl group exceeds 10, the compatibility with the refrigerant decreases, and phase separation may sometimes occur. The number of carbon atoms in the alkyl group is preferably 1 to 6.

[0159] In addition, R 101 , R 103 The alkyl portion of the acyl group in the formula (A) may be any of linear, branched, and cyclic. Specific examples of the alkyl portion of the acyl group include various groups having 1 to 9 carbon atoms as described above as specific examples of the alkyl group. When the number of carbon atoms of the acyl group exceeds 10, the compatibility with the refrigerant decreases and phase separation may occur. The preferred number of carbon atoms of the acyl group is 2 to 6.

[0160] In R 101 and R 103 When all R 101 With R 103 They can be the same or different from each other.

[0161] Furthermore, when l is 2 or more, a plurality of R 103 It can be the same or different.

[0162] In R 101 In the case of an aliphatic hydrocarbon group having 1 to 10 carbon atoms and having 2 to 6 bonding sites, the aliphatic hydrocarbon group may be chain-shaped or cyclic. Examples of aliphatic hydrocarbon groups having two bonding sites include ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, cyclopentylene, and cyclohexylene. Examples of aliphatic hydrocarbon groups having 3 to 6 bonding sites include residues obtained by removing hydroxyl groups from polyols such as trimethylolpropane, glycerol, pentaerythritol, sorbitol, 1,2,3-trihydroxycyclohexane, and 1,3,5-trihydroxycyclohexane.

[0163] When the carbon number of the aliphatic hydrocarbon group exceeds 10, the compatibility with the refrigerant decreases and phase separation may occur. The carbon number is preferably 2 to 6.

[0164] In the above general formula (9), R 102The alkylene group is an alkylene group having 2 to 4 carbon atoms. Examples of the oxyalkylene group as a repeating unit include oxyethylene, oxypropylene, and oxybutylene. The oxyalkylene groups in one molecule may be the same or may contain two or more oxyalkylene groups. It is preferred that at least oxypropylene units are contained in one molecule, and it is particularly preferred that oxypropylene units contain 50 mol% or more of the oxyalkylene units.

[0165] In the above general formula (9), l is an integer of 1 to 6, which can be calculated according to R 101 The number of bonding sites is determined by 101 In the case of an alkyl group or an acyl group, l is 1; in the case of R 101 In the case of an aliphatic hydrocarbon group having 2, 3, 4, 5 or 6 bonding sites, l is 2, 3, 4, 5 or 6, respectively. l is preferably 1 or 2. k is preferably a number such that the average value of k×l is 6 to 80.

[0166] From the viewpoint of economic efficiency and the above-mentioned effects, the structure of the polyoxyalkylene oil is preferably polyoxypropylene glycol dimethyl ether represented by the following general formula (10) and poly(oxyethylene / oxypropylene) glycol dimethyl ether represented by the following general formula (11). In addition, from the viewpoint of economic efficiency and the like, polyoxypropylene glycol monobutyl ether represented by the following general formula (12), polyoxypropylene glycol monomethyl ether represented by the following general formula (13), poly(oxyethylene / oxypropylene) glycol monomethyl ether represented by the following general formula (14), poly(oxyethylene / oxypropylene) glycol monobutyl ether represented by the following general formula (15), and polyoxypropylene glycol diacetate represented by the following general formula (16) are preferred.

[0167] CH3O-(C3H6O) h -CH3…(10)

[0168] (In the formula, h represents a number from 6 to 80.)

[0169] CH3O-(C2H4O) i -(C3H6O) j -CH3…(11)

[0170] (In the formula, i and j each represent a number greater than or equal to 1, and the total of i and j is a number from 6 to 80.)

[0171] C4H9O-(C3H6O) h -H…(12)

[0172] (In the formula, h represents a number from 6 to 80.)

[0173] CH3O-(C3H6O) h -H…(13)

[0174] (In the formula, h represents a number from 6 to 80.)

[0175] CH3O-(C2H4O) i -(C3H6O) j -H…(14)

[0176] (In the formula, i and j each represent a number greater than or equal to 1, and the total of i and j is a number from 6 to 80.)

[0177] C4H9O-(C2H4O) i -(C3H6O) j -H…(15)

[0178] (In the formula, i and j each represent a number greater than or equal to 1, and the total of i and j is a number from 6 to 80.)

[0179] CH3COO-(C3H6O) h -COCH3…(16)

[0180] (In the formula, h represents a number from 6 to 80.)

[0181] The polyoxyalkylene oils may be used alone or in combination of two or more.

[0182] (2-2) Hydrocarbon Refrigeration Oil

[0183] As the hydrocarbon-based refrigeration oil, for example, alkylbenzene can be used.

[0184] As alkylbenzenes, branched alkylbenzenes synthesized from propylene polymers and benzene using a catalyst such as hydrogen fluoride, and linear alkylbenzenes synthesized from normal alkanes and benzene using the same catalyst can be used. From the viewpoint of adjusting the viscosity suitable for lubricating base oil, the number of carbon atoms in the alkyl group is preferably 1 to 30, more preferably 4 to 20. In addition, although it also depends on the number of carbon atoms in the alkyl group, in order to make the viscosity within the set range, the number of alkyl groups in one molecule of alkylbenzene is preferably 1 to 4, more preferably 1 to 3.

[0185] Among them, hydrocarbon-based refrigeration oil is preferably circulated in the refrigeration cycle system together with the refrigerant. It is most preferred that the refrigeration oil dissolves in the refrigerant, but as long as it can circulate in the refrigeration cycle system together with the refrigerant, even a refrigeration oil with low solubility (such as the refrigeration oil described in Japanese Patent Gazette No. 2803451) can be used. In order to circulate the refrigeration oil in the refrigeration cycle system, the kinematic viscosity of the refrigeration oil is required to be small. As the kinematic viscosity of the hydrocarbon-based refrigeration oil, it is preferably 1 mm at 40°C. 2 / s above 50mm 2 / s or less, more preferably 1mm 2 / s above 25mm 2 / s or less.

[0186] These refrigerating machine oils may be used alone or in combination of two or more.

[0187] The content of the hydrocarbon-based refrigerating machine oil in the refrigerating machine working fluid may be, for example, 10 parts by mass to 100 parts by mass, and more preferably 20 parts by mass to 50 parts by mass, based on 100 parts by mass of the refrigerant composition.

[0188] (2-3) Resin particles

[0189] In the present invention, the refrigeration oil contains resin particles having a specific particle size distribution. The resin particles are aggregates of granular materials formed by resin. In addition, for the sake of convenience, in the present invention, "resin particles" refer to the state of being dispersed in the refrigeration oil. In addition, the "resin powder" described later is an aggregate of granular materials formed by resin, but refers to the state of being in a dry state. Having a "specific particle size distribution" means that the particle size of the resin particles has a relatively wide and wide range of particle size distribution.

[0190] As described later, the refrigeration cycle device has a refrigerant circuit, and a refrigerant composition, refrigeration oil, or a refrigeration working fluid exists depending on the location of the refrigerant circuit. When fine through holes are generated in such a refrigerant circuit, there is a possibility that the refrigerant leaks to the outside through the holes.

[0191] In the present invention, the resin particles work by having a part of them enter the holes that are the cause of the refrigerant leakage and at least partially block the holes, preferably substantially completely block the holes. The pore sizes of the blocked holes are not necessarily the same, and there may be various differences due to major reasons such as individual differences in the refrigeration cycle devices and the environment in which they are configured. In addition, depending on the environment in which the refrigerant circuit exists, there is a possibility that the generated holes grow and the pore size becomes larger. In order to cope with such various pore sizes, in the present invention, as a specific particle size distribution, the resin particles preferably have a relatively wide distribution range and a wide distribution. As a result, a reduction in the refrigerant leakage rate can be achieved.

[0192] In the present invention, as such a specific particle size distribution, specifically, D 50 and D 90 / D 10 As an indicator. Among them, D 10 , D 50 and D 90 The particle sizes are 10%, 50% and 90% respectively in the volume-based particle size distribution. As described in the examples below, the particle size is a value calculated from the particle size distribution obtained by measuring the resin particles dispersed in the refrigeration oil using a centrifugal sedimentation particle size distribution measuring device (CAPA-700, Horiba).

[0193] In the present invention, the specific particle size distribution is 2.0 μm to 10.0 μm. 50 and D of 4.0 to 14.0 90 / D 10 . D 50 It is a concept similar to the average particle size of resin particles. 50 When the particle size is smaller than this range, there is a tendency that the number of particles that are too small to pass through the pores and thus do not contribute to the closure of the pores increases. 50 If the particle size is larger than this range, there is a tendency that the number of particles which are too large to enter the pores and thus do not contribute to the closure of the pores increases.

[0194] D 50 The lower limit of D is preferably 2.5 μm, more preferably 3.0 μm, particularly preferably 3.5 μm, further preferably 4.0 μm, most preferably 4.5 μm, for example 5.0 μm. 50 The upper limit of is preferably 9.5 μm, more preferably 9.0 μm, particularly preferably 8.5 μm, further preferably 8.0 μm.

[0195] Although it depends on the environment in which the refrigeration cycle apparatus exists, for example, when the resin particles have the upper and / or lower limits as described above, it is expected that there is a tendency for the proportion of particles that can contribute to pore closure to increase, but this does not limit the present invention.

[0196] In addition, D 90 / D 10 The lower limit of is preferably 4.5, more preferably 5.0. 90 / D 10 The upper limit of D is preferably 13.5, more preferably 13.0. 90 / D 10 The value of means that the distribution range of particle size is large. 50 The same is true for the upper and lower limits. 90 / D 10 When the value is too small, the number of small particles that pass through the pores and do not contribute to occlusion increases. On the other hand, when it is too large, the number of large particles that enter the pores and do not contribute to occlusion tends to increase.

[0197] In the present invention, in a preferred embodiment, the specific particle size distribution includes a standard deviation of 3.0 μm to 8.0 μm. The standard deviation is a value calculated from the particle size distribution measured by the centrifugal sedimentation particle size distribution measuring device as described above. The lower limit of the standard deviation is more preferably 3.5 μm, and particularly preferably 4.0 μm. The upper limit of the standard deviation is more preferably 7.5 μm. Such a standard deviation value indicates that the distribution range of the particle size is large, and the upper and lower limits are similar to the above-mentioned D90 / D 10 The same choice is appropriate.

[0198] In the present invention, the resin constituting the resin particles can be any suitable resin, preferably with flexibility, easily suitable for the shape of the hole that becomes the cause of refrigerant leakage and enter. Specifically, the resin can be a silicone resin, a fluorine-containing resin, etc., preferably a fluorine-containing resin, such as more preferably polytetrafluoroethylene (PTFE) resin, tetrafluoroethylene / hexafluoropropylene copolymer (FEP) resin, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) resin, etc., particularly preferably polytetrafluoroethylene (PTFE) resin, further preferably low molecular weight PTFE resin. In the case of the resin particles consisting of silicone resin, fluorine-containing resin, etc., due to specific gravity, easily uniformly dispersed in refrigerator oil. In addition, heat resistance, durability, lubricity are also high, and refrigerant or refrigerator oil are also stable, thereby suitable.

[0199] The melt viscosity of low molecular weight PTFE resin at 380°C is preferably 1×10 2 ~7×10 5 Pa·s. In such a low molecular weight PTFE resin, it is preferred that perfluorocarboxylic acid and / or its salt having a carbon number of 8 to 14 is substantially free of perfluorocarboxylic acid (PFOA) and / or its salt having a carbon number of 8 is further preferred. In addition, in the present invention, "substantially free of" means that it is preferably less than 50 ppb, more preferably less than 25 ppb, further preferably less than 15 ppb, and particularly preferably less than 5 ppb on a mass basis. The lower limit is not particularly limited and can be an amount less than the detection limit. The amount of the above-mentioned perfluorocarboxylic acid and / or its salt can be measured by liquid chromatography.

[0200] As the manufacturing method of low molecular weight PTFE resin, there are polymerization method, radiation decomposition method, thermal decomposition method, etc. In the present invention, the low molecular weight PTFE resin obtained by polymerization method is preferred. In the present invention, in the case of the low molecular weight PTFE resin obtained by radiation decomposition method, it is preferred that the perfluorocarboxylic acid and / or its salt having a carbon number of 8 to 14 is not substantially contained.

[0201] In addition, the low molecular weight PTFE resin obtained by the radiolysis method is more preferably a low molecular weight PTFE resin obtained by the method described in International Patent Publication (WO) 2018 / 026012, WO2018 / 026017, WO2019 / 156036, WO2020 / 156037, WO2019 / 156038, WO2019 / 156039, WO2019 / 156053, WO2019 / 156065, WO2019 / 156067, and WO2019 / 156071.

[0202] Such resin particles can be contained in the refrigeration oil in any suitable content. Relative to 100 parts by mass of the refrigeration oil, for example, as a lower limit, preferably 0.0001 parts by mass, more preferably 0.001 parts by mass, further preferably 0.01 parts by mass, and particularly preferably 0.1 parts by mass. As an upper limit, preferably 20 parts by mass, more preferably 10 parts by mass, further preferably 5 parts by mass, and particularly preferably 3 parts by mass. When it is less than 0.0001 parts by mass, the effect of acting in a manner of substantially completely blocking the holes that are the cause of the refrigerant leakage becomes smaller. When it exceeds 20 parts by mass, the viscosity of the refrigeration oil increases and the fluidity of the refrigeration oil decreases.

[0203] The refrigeration oil containing resin particles having a specific particle size distribution of the present invention can be obtained by, for example, obtaining a resin powder having a wide particle size distribution, crushing it as needed, mixing it, and dispersing the resin powder in the refrigeration oil to obtain it. The crushing method, dispersion and mixing method can be any suitable known method, for example, a homogenizer, a roller mill, a sand mill, etc. can be used.

[0204] (2-4) Additives

[0205] The refrigerating machine oil may contain one or more additives.

[0206] Examples of the additives include acid scavengers, extreme pressure agents, antioxidants, defoamers, oiliness agents, metal deactivators such as copper deactivators, anti-wear agents, and compatibilizers.

[0207] The acid scavenger can use phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxidation, epoxidized soybean oil and other epoxy compounds, carbodiimide and the like. In addition, among these, from the viewpoint of compatibility, phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxidation are preferred. The alkyl group of the alkyl glycidyl ether and the alkylene group of the alkylene glycol glycidyl ether may have a branched chain. Their carbon number may be 3 or more and 30 or less, more preferably 4 or more and 24 or less, and further preferably 6 or more and 16 or less. In addition, the total carbon number of the oxidized α-olefin may be 4 or more and 50 or less, more preferably 4 or more and 24 or less, and further preferably 6 or more and 16 or less. The acid scavenger may be used alone or in combination.

[0208] As the extreme pressure agent, for example, a compound containing a phosphoric acid ester can be used.

[0209] As the phosphoric acid esters, phosphoric acid esters, phosphorous acid esters, acidic phosphoric acid esters, acidic phosphorous acid esters, and the like can be used. Compounds containing amine salts of phosphoric acid esters, phosphorous acid esters, acidic phosphoric acid esters, and acidic phosphorous acid esters can also be used.

[0210] Phosphate esters include triaryl phosphates, trialkyl phosphates, trialkylaryl phosphates, triaryl alkyl phosphates, trialenyl phosphates, etc. More specifically, phosphate esters include triphenyl phosphate, tricresyl phosphate, benzyl diphenyl phosphate, ethyl diphenyl phosphate, tributyl phosphate, ethyl dibutyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, ethyl phenyl diphenyl phosphate, diethyl phenyl phenyl phosphate, propyl phenyl diphenyl phosphate, dipropyl phenyl phenyl phosphate, triethyl phenyl phosphate, tripropyl phenyl phosphate, butyl phenyl diphenyl phosphate, dibutyl phenyl phenyl phosphate, tributyl phenyl phosphate, trihexyl phosphate, tri(2-ethylhexyl) phosphate, tridecyl phosphate, trilauryl phosphate, trimyristyl phosphate, tripalmityl phosphate, tristearyl phosphate, trioleyl phosphate, etc.

[0211] In addition, specific examples of phosphites include triethyl phosphite, tributyl phosphite, triphenyl phosphite, tricresyl phosphite, tri(nonylphenyl) phosphite, tri(2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite, triisooctyl phosphite, diphenyl isodecyl phosphite, tristearyl phosphite, trioleyl phosphite, and the like.

[0212] Specific examples of the acidic phosphate ester include 2-ethylhexyl acid phosphate, ethyl acid phosphate, butyl acid phosphate, oleyl acid phosphate, lignoceryl acid phosphate, isodecyl acid phosphate, lauryl acid phosphate, tridecyl acid phosphate, stearyl acid phosphate, and isostearyl acid phosphate.

[0213] Specific examples of the acidic phosphite include dibutyl hydrogen phosphite, dilauryl hydrogen phosphite, dioleyl hydrogen phosphite, distearyl hydrogen phosphite, diphenyl hydrogen phosphite, etc. Among the above phosphates, oleyl acid phosphate and stearyl acid phosphate are preferred.

[0214] Specific examples of monosubstituted amines used in the amine salts of phosphoric acid esters, phosphorous acid esters, acidic phosphoric acid esters or acidic phosphorous acid esters include butylamine, amylamine, hexylamine, cyclohexylamine, octylamine, laurylamine, stearylamine, oleylamine, benzylamine, etc. Specific examples of disubstituted amines include dibutylamine, diamylamine, dihexylamine, dicyclohexylamine, dioctylamine, dilaurylamine, distearylamine, dioleylamine, dibenzylamine, stearyl-monoethanolamine, decyl-monoethanolamine, hexyl-monopropanolamine, benzyl-monoethanolamine, phenyl-monoethanolamine, tolyl-monopropanol, etc. Specific examples of the trisubstituted amines include tributylamine, tripentylamine, trihexylamine, tricyclohexylamine, trioctylamine, trilaurylamine, tristearylamine, trioleylamine, tribenzylamine, dioleyl-monoethanolamine, dilauryl-monopropanolamine, dioctyl-monoethanolamine, dihexyl-monopropanolamine, dibutyl-monopropanolamine, oleyl-diethanolamine, stearyl-dipropanolamine, lauryl-diethanolamine, octyl-dipropanolamine, butyl-diethanolamine, benzyl-diethanolamine, phenyl-diethanolamine, tolyl-dipropanolamine, xylyl-diethanolamine, triethanolamine, and tripropanolamine.

[0215] In addition, as extreme pressure agents other than the above, for example, there can be listed: extreme pressure agents of organic sulfur compounds such as monosulfides, polysulfides, sulfoxides, sulfones, thiosulfinates, sulfurized oils and fats, thiocarbonates, thiophenes, thiazoles, and mesylates; extreme pressure agents of thiophosphates such as thiophosphate triesters; extreme pressure agents of esters such as higher fatty acids, hydroxyaryl fatty acids, polyol esters, and acrylic esters; extreme pressure agents of chlorinated hydrocarbons such as chlorinated paraffins, and organic chlorine such as chlorinated carboxylic acid derivatives; extreme pressure agents of organic fluoride such as fluorinated aliphatic carboxylic acids, fluorinated vinyl resins, fluorinated alkyl polysiloxanes, and fluorinated graphite; extreme pressure agents of alcohols such as higher alcohols; extreme pressure agents of metal compounds such as naphthenates (lead naphthenate, etc.), fatty acid salts (lead fatty acid, etc.), thiophosphates (zinc dialkyl dithiophosphate, etc.), thiocarbamates, organic molybdenum compounds, organic tin compounds, organic germanium compounds, and borate esters.

[0216] As the antioxidant, for example, phenolic antioxidants and amine-based antioxidants can be used. Phenolic antioxidants include 2,6-di-tert-butyl-4-methylphenol (DBPC), 2,6-di-tert-butyl-4-ethylphenol, 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-butylphenol, di-tert-butyl-p-cresol, bisphenol A, and the like. In addition, amine-based antioxidants include N,N'-diisopropyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine, phenyl-α-naphthylamine, N.N'-diphenyl-p-phenylenediamine, N,N-di(2-naphthyl)-p-phenylenediamine, and the like. Among them, an oxygen scavenger that captures oxygen can also be used as the antioxidant.

[0217] As the defoaming agent, for example, a silicon compound can be used.

[0218] As the oiliness agent, for example, higher alcohols, fatty acids, etc. can be used.

[0219] As a metal deactivator such as a copper deactivator, benzotriazole or a derivative thereof can be used.

[0220] As the anti-wear agent, zinc dithiophosphate or the like can be used.

[0221] The compatibilizer is not particularly limited and can be appropriately selected from commonly used compatibilizers. One or more types can be used alone. Examples of the compatibilizer include polyoxyalkylene glycol ethers, amides, nitriles, ketones, chlorinated hydrocarbons, esters, lactones, aryl ethers, fluoroethers, and 1,1,1-trifluoroalkanes. As the compatibilizer, polyoxyalkylene glycol ethers are particularly preferred.

[0222] In addition, load-bearing additives, chlorine scavengers, detergent dispersants, viscosity index improvers, heat resistance improvers, stabilizers, corrosion inhibitors, heat resistance improvers, pour point depressants, rust inhibitors, etc. may be added to the refrigeration oil as needed.

[0223] The proportion of the amount of each of the above-mentioned additives contained in the refrigerator oil can be 0.01% by mass or more and 5% by mass or less, preferably 0.05% by mass or more and 3% by mass or less. In addition, in the refrigerator working fluid mixed with the refrigerant composition and the refrigerator oil, the proportion of the additive is preferably 5% by mass or less, more preferably 3% by mass or less.

[0224] Furthermore, the chlorine concentration of the refrigerating machine oil is preferably 50 ppm or less, and the sulfur concentration is preferably 50 ppm or less.

[0225] (3) Refrigerant circuit

[0226] Figure 1 An example of a refrigerant circuit 10 included in an air-conditioning apparatus 1 as a refrigeration cycle apparatus is shown.

[0227] The air conditioning device 1 is a device for indoor cooling and / or heating by performing a vapor compression refrigeration cycle operation. The air conditioning device 1 mainly includes an outdoor unit 2, an indoor unit 3, and a liquid-side refrigerant connection pipe 9 and a gas-side refrigerant connection pipe 8 connecting the outdoor unit 2 and the indoor unit 3.

[0228] The refrigerant circuit 10 of the air conditioning device 1 includes a compressor 4, an outdoor heat exchanger 5, an expansion valve 6, and an indoor heat exchanger 7, which are connected through a liquid-side refrigerant connection pipe 9, a gas-side refrigerant connection pipe 8, and other refrigerant pipes to form the above-mentioned compression-type refrigerant circuit. In addition, the air conditioning device 1 includes a microcomputer or a memory, etc., and has a control unit for driving and controlling various actuators.

[0229] In addition, the refrigerant circuit 10 contains a refrigerator working fluid containing the above-mentioned refrigerant composition as a refrigerant and refrigeration oil.

[0230] (3-1) Indoor unit

[0231] The indoor unit 3 is installed on the indoor ceiling or wall, and is connected to the outdoor unit 2 via the liquid-side refrigerant connection pipe 9 and the gas-side refrigerant connection pipe 8, forming a part of the refrigerant circuit 10. In addition, a plurality of indoor units 3 may be connected in parallel in the refrigerant circuit 10.

[0232] The indoor unit 3 includes an indoor heat exchanger 7 and an indoor fan 13 .

[0233] The indoor heat exchanger 7 is not particularly limited and is composed of, for example, a heat transfer tube and a plurality of fins. The indoor heat exchanger 7 functions as an evaporator of the refrigerant to cool the indoor air during cooling operation, and functions as a condenser of the refrigerant to heat the indoor air during heating operation.

[0234] The indoor fan 13 draws indoor air into the indoor unit 3, exchanges heat with the refrigerant in the indoor heat exchanger 7, and then generates an air flow supplied to the room as supply air. The indoor fan 13 includes an indoor fan motor.

[0235] (3-2) Outdoor unit

[0236] The outdoor unit 2 is installed outdoors, and is connected to the indoor unit 3 via a liquid-side refrigerant communication pipe 9 and a gas-side refrigerant communication pipe 8 .

[0237] The outdoor unit 2 includes a compressor 4 , an outdoor heat exchanger 5 , an outdoor fan 12 , an expansion valve 6 , a accumulator 11 , a four-way switching valve 10 , a liquid-side closing valve 14 , a gas-side closing valve 15 , and the like.

[0238] The compressor 4 is a positive displacement compressor driven by a compressor electric motor or the like. The compressor electric motor can be driven by receiving electric power supply via an inverter device (not shown), for example.

[0239] The outdoor heat exchanger 5 is not particularly limited, and is composed of, for example, a heat transfer tube and a plurality of fins. The outdoor heat exchanger 5 functions as a condenser of the refrigerant during cooling operation, and functions as an evaporator of the refrigerant during heating operation.

[0240] The outdoor fan 12 draws outdoor air into the outdoor unit 2, exchanges heat with the refrigerant in the outdoor heat exchanger 5, and then generates an air flow to be exhausted outdoors. The outdoor fan 12 includes an outdoor fan motor.

[0241] The expansion valve 6 can adjust the pressure of the refrigerant passing therethrough by adjusting the valve opening.

[0242] The accumulator 11 is provided on the suction side of the compressor 4 between the four-way switching valve 10 and the compressor 4 , and separates the refrigerant in a liquid state and the refrigerant in a gas state.

[0243] The four-way switching valve 10 can switch between a cooling operation connection state and a heating operation connection state by switching the connection state. The cooling operation connection state connects the discharge side of the compressor 4 with the outdoor heat exchanger 5, and connects the downstream side of the liquid reservoir 11 with the gas side closing valve 15. The heating operation connection state connects the discharge side of the compressor 4 with the gas side closing valve 15, and connects the downstream side of the liquid reservoir 11 with the outdoor heat exchanger 5.

[0244] The liquid-side closing valve 14 and the gas-side closing valve 15 are valves provided at connection ports with external equipment and pipes (specifically, the liquid-side refrigerant communication pipe 5 and the gas-side refrigerant communication pipe 6 ).

[0245] (3-3) Refrigeration cycle

[0246] In the air conditioning device 1, during cooling operation, the four-way switching valve 10 is in a cooling operation connection state, and the high-temperature and high-pressure refrigerant ejected from the compressor 4 is condensed in the outdoor heat exchanger 5 functioning as a condenser of the refrigerant, is decompressed when passing through the expansion valve 6, and is supplied to the gas side of the indoor unit 3 via the liquid-side refrigerant connection pipe 9. The refrigerant supplied to the indoor unit 3 evaporates in the indoor heat exchanger 7 functioning as an evaporator of the refrigerant, and is sucked into the compressor 4 via the gas-side refrigerant connection pipe 8 and the accumulator 11 of the outdoor unit 2.

[0247] In the air conditioning device 1, during the heating operation, the four-way switching valve 10 is in the heating operation connection state, and the high-temperature and high-pressure refrigerant discharged from the compressor 4 is sent to the gas side of the indoor unit 3 through the gas-side refrigerant connection pipe 8. The refrigerant sent to the indoor unit 3 is condensed in the indoor heat exchanger 7 that functions as a condenser of the refrigerant, and is sent to the expansion valve 6 of the outdoor unit 2 through the liquid-side refrigerant connection pipe 9. The refrigerant that has been decompressed when passing through the expansion valve 6 evaporates in the outdoor heat exchanger 5 that functions as an evaporator of the refrigerant, and is sucked into the compressor 4 through the accumulator 11.

[0248] In addition, as refrigeration cycle device, it is not particularly limited, for example, the cooling device of room air conditioner, modular air conditioner, refrigerator, automobile air conditioner, hot water supplier, dehumidifier, freezer, freezing and refrigerating warehouse, vending machine, showcase, chemical equipment etc. can be listed, wherein, it is particularly preferred to use in the refrigerator with closed compressor. In addition, each refrigerator oil of the present embodiment can be used in the compressor of any form such as reciprocating motion type, rotary type, centrifugal type. In addition, in these refrigerators, the refrigerator oil of the present embodiment can be used as the refrigerator working fluid mixed with the refrigerant composition.

[0249] (4) Definition of terms for refrigerants and refrigerant compositions (4-1)

[0250] In this specification, the term "refrigerant" includes at least compounds that are marked with refrigerant numbers (ASHRAE numbers) starting with R that indicate the type of refrigerant as specified by ISO817 (International Organization for Standardization), and also includes compounds that have not yet been marked with refrigerant numbers but have the same properties as them as refrigerants. From the perspective of the structure of the compounds, refrigerants are roughly divided into "fluorocarbon compounds" and "non-fluorocarbon compounds". "Fluorocarbon compounds" include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs). As "non-fluorocarbon compounds", propane (R290), propylene (R1270), butane (R600), isobutane (R600a), carbon dioxide (R744) and ammonia (R717) can be listed. Among them, "refrigerant" also includes a mixture of multiple refrigerants.

[0251] In this specification, the term "refrigerant composition" includes the refrigerant itself (including a mixture of refrigerants) and other components, thereby distinguishing from the refrigerant itself (including a mixture of refrigerants). The "refrigerant composition" includes a composition that can be used to obtain a working fluid for a refrigerator by mixing with at least a refrigerator oil.

[0252] In this specification, the term "refrigerating machine working fluid" includes a composition containing a refrigerant composition and a refrigerating machine oil, and is distinguished from a "refrigerant composition" and may be referred to as a "refrigerating machine oil-containing working fluid".

[0253] In addition, as a term including at least three aspects of "refrigerant", "refrigerant composition" and "refrigerator working fluid (working fluid containing refrigerator oil)", "refrigerant-containing composition" may be used.

[0254] In this specification, the term "replacement" when used in the context of "replacing" the first refrigerant with a second refrigerant, as a first type, refers to a device designed to operate using the first refrigerant, which can be operated under optimal conditions using the second refrigerant by only changing a small number of components (at least one of the refrigeration oil, seals, gaskets, expansion valves, dryers or other components) and adjusting the equipment as needed. In other words, this type refers to operating the same equipment with a "replacement" refrigerant. As a form of "replacement" of this type, there can be "direct (drop in) replacement", "nearly direct (nearly drop in) replacement" and "retrofit" in order from small to large in the degree of change and adjustment required when replacing with the second refrigerant.

[0255] The second type is to use a second refrigerant and the equipment designed to operate with the second refrigerant for the same purpose as the existing purpose of the first refrigerant, and this type is also included in the term "replacement". This type means "replacing" the refrigerant to provide the same purpose.

[0256] In this specification, the term "refrigerator" refers to all devices that remove heat from objects or spaces to a temperature lower than the surrounding external air and maintain the low temperature. In other words, a refrigerator is a conversion device that obtains energy from the outside to perform work and convert energy in order to move heat from a low temperature to a high temperature.

[0257] In this specification, the refrigerant is "WCF slightly flammable" means that according to the US ANSI / ASHRAE34-2013 standard, the burning speed of the most flammable composition (the worst case of formulation for flammability (WCF)) is 10 cm / s or less. In addition, in this specification, the refrigerant is "ASHRAE slightly flammable" means that the burning speed of WCF is 10 cm / s or less, and the burning speed of the most flammable fractionation composition (the worst case of fractionation for flammability (WCFF)) determined by the leakage test during storage, transportation and use using WCF based on ANSI / ASHRAE34-2013 is 10 cm / s or less, and the flammability classification of the US ANSI / ASHRAE34-2013 standard is judged to be "2L grade".

[0258] In this manual, regarding a refrigerant, the so-called "RCL is x% or more" means that the refrigerant concentration limit (Refrigerant Concentration Limit; RCL) calculated in accordance with the U.S. ANSI / ASHRAE34-2013 standard for such a refrigerant is x% or more. RCL is the concentration limit in the air after taking into account the safety factor. It is an indicator established for the purpose of reducing the risk of acute toxicity, asphyxiation and flammability in a confined space where people exist. RCL is determined in accordance with the above standards. Specifically, among the acute toxicity exposure limit (Acute-Toxicity Exposure Limit; ATEL), oxygen deprivation limit (Oxygen Deprivation Limit; ODL) and flammable concentration limit (FCL) calculated in accordance with 7.1.1, 7.1.2 and 7.1.3 of the above standards, the lowest concentration is the RCL.

[0259] In this specification, the temperature glide refers to the absolute value of the difference between the start temperature and the end temperature of the phase change process of the refrigerant composition of the present invention in the heat exchanger of the refrigerant system.

[0260] (4-2) Use of refrigerants

[0261] The refrigerant of the present invention can be preferably used as a working fluid of a refrigerator.

[0262] The composition of the present invention is suitable for use as a refrigerant replacing HFC refrigerants such as R410A, R407C and R404A, and HCFC refrigerants such as R22.

[0263] (4-3) Refrigerant composition

[0264] The refrigerant composition of the present invention contains at least the refrigerant of the present invention and can be used for the same purpose as the refrigerant of the present invention. In addition, the refrigerant composition of the present invention can be used to obtain a working fluid for a refrigerator by further mixing it with at least a refrigerator oil.

[0265] In addition to the refrigerant of the present invention, the refrigerant composition of the present invention also contains at least one other component. The refrigerant composition of the present invention may contain at least one of the following other components as required. As described above, when the refrigerant composition of the present invention is used as a working fluid of a refrigerator, it is usually mixed with at least a refrigerator oil. Therefore, the refrigerant composition of the present invention preferably does not substantially contain refrigerator oil. Specifically, with respect to the refrigerant composition of the present invention, the content of refrigerator oil is preferably 0 to 1% by mass, more preferably 0 to 0.1% by mass, relative to the entire refrigerant composition.

[0266] (4-3-1) Water

[0267] The refrigerant composition of the present invention may contain a trace amount of water. The water content in the refrigerant composition is preferably 0.1% by mass or less relative to the entire refrigerant.

[0268] (4-3-2) Tracer

[0269] When the refrigerant composition of the present invention is diluted, contaminated, or undergoes any other changes, a tracer may be added to the refrigerant composition of the present invention at a detectable concentration in order to track the changes.

[0270] The refrigerant composition of the present invention may contain one type of tracer alone or two or more types of tracers.

[0271] The tracer is not particularly limited and can be appropriately selected from commonly used tracers. It is preferred to select a compound that does not become an impurity that is inevitably mixed into the refrigerant of the present invention as the tracer.

[0272] Examples of the tracer include hydrofluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrochlorocarbons, fluorocarbons, deuterated hydrocarbons, deuterated hydrofluorocarbons, perfluorocarbons, fluoroethers, bromides, iodides, alcohols, aldehydes, ketones, and nitrous oxide (N2O).

[0273] As tracers, hydrofluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrochlorocarbons, fluorocarbons and fluoroethers are particularly preferred.

[0274] As the tracer, the following compounds are specifically preferred.

[0275] FC-14 (tetrafluoromethane, CF4)

[0276] HCC-40 (Methyl Chloride, CH3Cl)

[0277] HFC-23 (trifluoromethane, CHF3)

[0278] HFC-41 (fluoromethane, CH3Cl)

[0279] HFC-125 (pentafluoroethane, CF3CHF2)

[0280] HFC-134a (1,1,1,2-tetrafluoroethane, CF3CH2F)

[0281] HFC-134 (1,1,2,2-tetrafluoroethane, CHF2CHF2)

[0282] HFC-143a(1,1,1-trifluoroethane, CF3CH3)

[0283] HFC-143 (1,1,2-trifluoroethane, CHF2CH2F)

[0284] HFC-152a(1,1-difluoroethane, CHF2CH3)

[0285] HFC-152 (1,2-difluoroethane, CH2FCH2F)

[0286] HFC-161 (Ethyl fluoride, CH3CH2F)

[0287] HFC-245fa (1,1,1,3,3-pentafluoropropane, CF3CH2CHF2)

[0288] HFC-236fa (1,1,1,3,3,3-hexafluoropropane, CF3CH2CF3)

[0289] HFC-236ea (1,1,1,2,3,3-hexafluoropropane, CF3CHFCHF2)

[0290] HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane, CF3CHFCF3)

[0291] HCFC-22 (chlorodifluoromethane, CHClF2)

[0292] HCFC-31 (chlorofluoromethane, CH2ClF)

[0293] CFC-1113 (Chlorotrifluoroethylene, CF2=CClF)

[0294] HFE-125 (trifluoromethyl-difluoromethyl ether, CF3OCHF2)

[0295] HFE-134a (trifluoromethyl-fluoromethyl ether, CF3OCH2F)

[0296] HFE-143a (trifluoromethyl-methyl ether, CF3OCH3)

[0297] HFE-227ea (trifluoromethyl-tetrafluoroethyl ether, CF3OCHFCF3)

[0298] HFE-236fa (trifluoromethyl-trifluoroethyl ether, CF3OCH2CF3)

[0299] The tracer compound may be present in the refrigerant composition at a combined concentration of about 10 parts per million (ppm) by weight to about 1000 ppm. Preferably, the tracer compound is present in the refrigerant composition at a combined concentration of about 30 ppm to about 500 ppm, and most preferably, the tracer compound is present in the refrigerant composition at a combined concentration of about 50 ppm to about 300 ppm.

[0300] (4-3-3) Ultraviolet fluorescent dye

[0301] The refrigerant composition of the present invention may contain one type of ultraviolet fluorescent dye alone or two or more types thereof.

[0302] The ultraviolet fluorescent dye is not particularly limited and can be appropriately selected from commonly used ultraviolet fluorescent dyes.

[0303] Examples of the ultraviolet fluorescent dye include naphthalimide, coumarin, anthracene, phenanthrene, xanthene, thioxanthene, benzoxanthene, fluorescein, and derivatives thereof. As the ultraviolet fluorescent dye, any one or both of naphthalimide and coumarin are particularly preferred.

[0304] (4-3-4) Stabilizer

[0305] The refrigerant composition of the present invention may contain one type of stabilizer alone or two or more types of stabilizers.

[0306] The stabilizer is not particularly limited and can be appropriately selected from commonly used stabilizers.

[0307] Examples of the stabilizer include nitro compounds, ethers, and amines.

[0308] Examples of the nitro compound include aliphatic nitro compounds such as nitromethane and nitroethane, and aromatic nitro compounds such as nitrobenzene and nitrostyrene.

[0309] Examples of the ethers include 1,4-dioxane and the like.

[0310] Examples of the amines include 2,2,3,3,3-pentafluoropropylamine and diphenylamine.

[0311] Other examples include butylated hydroxyxylene and benzotriazole.

[0312] The content of the stabilizer is not particularly limited, but is usually preferably 0.01 to 5% by mass, more preferably 0.05 to 2% by mass, based on the entire refrigerant.

[0313] (4-3-5) Inhibitor

[0314] The refrigerant composition of the present invention may contain one type of polymerization inhibitor alone or two or more types thereof.

[0315] The polymerization inhibitor is not particularly limited and can be appropriately selected from commonly used polymerization inhibitors.

[0316] Examples of the polymerization inhibitor include 4-methoxy-1-naphthol, hydroquinone, hydroquinone methyl ether, dimethyl-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, and benzotriazole.

[0317] The content of the polymerization inhibitor is not particularly limited, but is usually preferably 0.01 to 5% by mass, more preferably 0.05 to 2% by mass, based on the entire refrigerant.

[0318] (4-4) Working fluid containing refrigeration oil

[0319] The working fluid containing refrigeration oil of the present invention contains at least the refrigerant or refrigerant composition of the present invention and refrigeration oil, and is used as the working fluid of a refrigerator. Specifically, the working fluid containing refrigeration oil of the present invention is obtained by mixing the refrigeration oil and the refrigerant or refrigerant composition used in the compressor of the refrigerator. The working fluid containing refrigeration oil usually contains 10 to 50% by mass of refrigeration oil.

[0320] The refrigerating machine oil contained in the refrigerating machine oil-containing working fluid may contain one type of the refrigerating machine oil listed in the column (2) Refrigerating machine oil, or may contain two or more types. The refrigerating machine oil may further contain the additives listed in the column (2-3) Additives.

[0321] As the refrigerant that can be used in the present invention, HFC refrigerants such as R410A, R407C, R404A and R32 can be listed. HFO refrigerants such as R1123, R1234yf and R1234ze can also be used. For example, refrigerants 1 to 75 shown in Tables 1 and 2 below can be used.

[0322] [Table 1]

[0323] name composition (Weight %) Refrigerant 1 R32 / R125 / R1234yf (15 / 25 / 60) Refrigerant 2 R5138 R1234yf / R134a (58.5 / 41.5) Refrigerant 3 R1234yf R1234yf (100) Refrigerant 4 R463A R744 / R32 / R125 / R1234yf / R134a (6.0 / 36.0 / 30.0 / 14.0 / 14.0) Refrigerant 5 R452B R32 / R125 / R1234yf (67 / 7 / 26) Refrigerant 6 R32 / R1234yf (72.5 / 27.5) Refrigerant 7 R454B R32 / R1234yf (68.9 / 31.1) Refrigerant 8 R449A R32 / R125 / R1234yf / R134a (24.3 / 24.7 / 25.3 / 25.7) Refrigerant 9 R452A R32 / R125 / R1234yf (11.0 / 59.0 / 30.0) Refrigerant 10 R454A R32 / R1234yf (35 / 65) Refrigerant 11 R449C R32 / R125 / R1234yf / R134a (20 / 20 / 31 / 29) Refrigerant 12 R454C R32 / R1234yf (21.5 / 78.5) Refrigerant 13 R513A R1234yf / R134a (56 / 44) Refrigerant 14 R1336mzz(Z) R1336mzz(Z) (100) Refrigerant 15 R1336mzz(E) R1336mzz(E) (100) Refrigerant 16 R514A R1336mzz(Z) / R1130(E) (74.7 / 25.3) Refrigerant 17 R32 / R125 / R1234ze(E) (68 / 15 / 17) Refrigerant 18 R447B R32 / R125 / R1234ze(E) (68 / 8 / 24) Refrigerant 19 R447A R32 / R125 / R1234ze(E) (68 / 35 / 28.5) Refrigerant 20 R32 / R1234yf / R1234ze(E) (73 / 15 / 12) Refrigerant 21 R32 / R1234ze(E) (72 / 27) Refrigerant 22 R446A R32 / R1234ze(E) / Butane (68 / 29 / 3) Refrigerant 23 R448A R32 / R125 / R1234yf / R134a / R1234ze(E) (26 / 26 / 20 / 21 / 7) Refrigerant 24 R32 / R125 / R1234yf / R134a / R1234ze(E) (25 / 25 / 9 / 21 / 20) Refrigerant 25 R322 / R1251R1234yf / R134a (25 / 25 / 30 / 20) Refrigerant 26 R32 / R1234yf / R152a / R1234ze(E) (40 / 20 / 10 / 30) Refrigerant 27 R455A R744 / R32 / R1234yf (3.0 / 21.5 / 75.5) Refrigerant 28 R32 / R125 / R134a / R1234yf (13 / 13 / 31 / 43) Refrigerant 29 R32 / R125 / R1234yf / R134a / R1234ze(E) (12.5 / 12.5 / 13.5 / 31.5 / 30) Refrigerant 30 R32 / R152a / R1234ze(E) (45 / 20 / 35) Refrigerant 31 R444B R32 / R152a / R1234ze(E) (41.5 / 10 / 48.5) Refrigerant 32 R1234yf / R134a / R1234ze(E) (18 / 42 / 40) Refrigerant 33 R450A R134a / R1234ze(E) (42 / 58) Refrigerant 34 R515A R1234ze(E) / R27ea (88 / 12) Refrigerant 35 R515B R1234ze(E) / R227ea (91.1 / 8.9) Refrigerant 36 R1234ze(E) R1234ze(E) (100) Refrigerant 37 R1233zd(E) R1233zd(E) (100) Refrigerant 38 R32 / R125 / CF31 (49.0 / 11.5 / 39.5) Refrigerant 39 R32 / R1234yf / R134a (50 / 40 / 10) Refrigerant 40 R459A R32 / R1234yf / R1234ze(E) (68 / 26 / 6) Refrigerant 41 R452C R32 / R125 / R1234yf (12.5 / 61 / 26.5) Refrigerant 42 R449B R32 / R125 / R1234yf / R134a (25.2 / 24.3 / 23.2 / 27.3) Refrigerant 43 R32 / R1234γf / R134a (28 / 51 / 21) Refrigerant 44 R32 / R1234yf / R152a (35 / 55 / 10) Refrigerant 45 R32 / R1234yf (29 / 71) Refrigerant 46 R465A R-32 / R290 / R1234yf (21.0 / 7.9 / 71.1) Refrigerant 47 R457A R32 / R1234yf / R152a (18 / 70 / 12) Refrigerant 48 R32 / R125 / R1234yf / R134a (25 / 30 / 20 / 25) Refrigerant 49 R32 / R125 / R1234yf / R134a Refrigerant 50 R32 / R1234yf / R134a (6 / 31 / 63)

[0324] [Table 2]

[0325]

[0326] As an example of an embodiment of the present invention, a refrigeration cycle device including a working fluid for a refrigerator is first described, wherein the working fluid for a refrigerator includes a refrigerant composition containing a refrigerant and a refrigerator oil containing resin particles, and the present invention also provides a refrigerant leakage preventer including refrigerator oil containing resin particles. The refrigerant leakage preventer contains the above-mentioned resin particles of the present invention and refrigerator oil, and may contain other components as needed.

[0327] The refrigerant leakage preventing agent can be supplied to the refrigerant circuit and sealed in advance before the refrigeration cycle device in which the working fluid for the refrigerator does not contain the resin particles starts to operate. The sealed state corresponds to the refrigeration cycle device containing the working fluid for the refrigerator of the present invention. Afterwards, when the refrigeration cycle device starts to operate, even if a hole that causes refrigerant leakage is formed in the refrigerant circuit, the hole can be quickly blocked by the resin particles supplied in advance.

[0328] In another aspect of the present invention, the refrigeration cycle device is operated in a state where the refrigeration working fluid does not contain the resin particles, and then the refrigeration working fluid is injected into the refrigerant circuit. The injection can be performed, for example, by sucking into the compressor of the outdoor unit according to Japanese Patent Application Laid-Open No. 2013-139934.

[0329] In another embodiment of the present invention, when refrigerant leakage occurs during operation of a refrigeration cycle device, or when leakage is suspected, a refrigerant leakage preventer is injected into the refrigerant circuit. Resin particles contained in the injected refrigerant leakage preventer enter the hole that is the cause of the leakage, thereby preventing or suppressing the refrigerant leakage.

[0330] Such a refrigerant leakage preventing agent may contain resin particles in any suitable content in the refrigerating machine oil. In the refrigerant leakage preventing agent, the lower limit of the content of the resin particles contained relative to 100 parts by mass of the refrigerating machine oil is preferably 0.01 parts by mass, more preferably 0.05 parts by mass, and further preferably 0.1 parts by mass. In addition, the upper limit of the content of the resin particles contained relative to 100 parts by mass of the refrigerating machine oil is preferably 50 parts by mass, more preferably 30 parts by mass, further preferably 10 parts by mass, and particularly preferably 5 parts by mass.

[0331] Example

[0332] Hereinafter, the present invention will be described in more detail using Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0333] <Preparation of resin particles of Examples 1 to 6>

[0334] An aqueous dispersion of low molecular weight PTFE was obtained by the method described in Example 7 of International Publication No. 2009 / 020187. 20 g of nitric acid was added to 3000 g of the obtained aqueous dispersion of low molecular weight PTFE, and the mixture was vigorously stirred to coagulate the mixture. Then, 20 g of a 24% by mass sodium hydroxide aqueous solution was added for neutralization to obtain a wet PTFE resin powder.

[0335] The wet powder was filtered, washed with 1800 g of pure water, and dried in a hot air circulation dryer at 160° C. for 18 hours to obtain a low molecular weight PTFE resin powder. The obtained resin powder was pulverized in a ball mill as needed.

[0336] The particle size distribution of the low molecular weight PTFE resin powder used in the examples described below is adjusted by appropriately selecting the stirring conditions during coagulation (specifically, the rotation speed, temperature, etc.) and / or the pulverizing conditions of the obtained low molecular weight PTFE resin powder using a ball mill, thereby obtaining the PTFE resin powder used in Examples 1 to 6.

[0337] <Adjustment of Resin Pellets in Example 7>

[0338] Low molecular weight PTFE resin powder was obtained by the method described in Example 2 disclosed in International Publication No. 2018 / 026012.

[0339] <Measurement of Particle Size Distribution of Resin Powder>

[0340] The particle size distribution (D) of the obtained resin powder was measured using a laser diffraction particle size distribution measuring apparatus (HELOS & RODOS) manufactured by JEOL Ltd. without using a cascade and at a dispersion pressure of 3.0 bar. 10 , D 50 and D 90 ). 50 as the average particle size.

[0341] <Determination of the content of perfluorooctanoic acid and its salts>

[0342] The content of perfluorooctanoic acid and its salts was determined using a liquid chromatography mass spectrometer (Waters, LC-MS ACQUITY UPLC / TQD). 5 ml of acetonitrile was added to 1 g of the test powder, and ultrasonic treatment was performed for 60 minutes to extract perfluorooctanoic acid. The obtained liquid phase was measured using the MRM (Multiple Reaction Monitoring) method. As the mobile phase, acetonitrile (A) and ammonium acetate aqueous solution (20 mmol / L) (B) were transported in a concentration gradient (A / B = 40 / 60-2min-80 / 20-1min). A separation column (ACQUITY UPLC BEH C18 1.7μm) was used, the column temperature was 40°C, and the injection volume was 5μL. The ionization method used ESI (Electrospray ionization) Negative, the cone voltage was set to 25V, and the parent ion molecular weight / daughter ion molecular weight was measured to be 413 / 369. The content of perfluorooctanoic acid and its salts was calculated by the external standard method. The detection limit of this measurement was 5 ppb. <Measurement of particle size distribution of resin particles in refrigeration oil>

[0343] The refrigeration oil containing resin particles (containing 0.5 parts by mass of resin particles per 100 parts by mass of commercially available refrigeration oil (ether-based refrigeration oil)) was treated with an ultrasonic vibrator for 30 minutes to obtain a uniform dispersion, and the particle size distribution (D) was measured using a centrifugal sedimentation particle size distribution measuring device (CAPA-700, Horiba). 10 , D 50 and D 90 and standard deviation).

[0344] <Measurement of refrigerant leakage rate>

[0345] The air conditioner (refrigerant R-410A: filling amount 0.75 kg, commercially available refrigeration oil (ether-based refrigeration oil) filling amount 0.3 L) as a refrigeration cycle device was operated for cooling. The outdoor temperature and indoor temperature were both 40°C, and the refrigerant pressure was 3.2 MPa or more. The operation time was 150 hours.

[0346] The copper piping portion of the air conditioner (the gas-side refrigerant connection piping serving as the connecting piping connecting the outdoor unit and the indoor unit, through which the evaporated refrigerant passes) is maintained in an environment (adjusted to a temperature of 40°C and a humidity of 90% or more) containing an aqueous formic acid solution (0.005% by mass).

[0347] Before the start of refrigeration operation, nitrogen pressure (3.2 MPa) was applied to the copper piping part to measure the change of nitrogen pressure over time, and the leakage rate of nitrogen per unit time was calculated based on the reduced pressure. The copper piping used in the measurement was a used piping (so it could have holes that could cause refrigerant leakage) and had a pre-operation leakage rate of 0.5 to 3.0 g-N2 / hr. After 150 hours of operation, the refrigerant gas was removed from the corresponding piping part, and the leakage rate of nitrogen from the copper piping part was also measured to find the post-operation leakage rate.

[0348] (Refrigerant leakage rate) = [(leakage rate after operation) / (leakage rate before operation)] × 100 (%)

[0349] Example 1

[0350] 1.0 parts by mass of the PTFE resin powder (average particle size 4.2 μm) of Example 1 shown in Table 3 below was added to 100 parts by mass of commercially available refrigeration oil (ether-based refrigeration oil), and mixed using a homogenizer to obtain the refrigeration oil of the present invention. Based on Japanese Patent Publication No. 2013-139934, 50 ml of the obtained refrigeration oil was sucked into the compressor of the outdoor unit to form the refrigeration cycle device of the present invention. The refrigeration cycle device comprises the refrigeration oil of the present invention and the refrigerant composition. Afterwards, the air conditioner was operated.

[0351] Example 2

[0352] The air conditioner was operated by suction in the same manner as in Example 1 except that the PTFE resin powder of Example 2 (average particle size 5.8 μm) shown in Table 3 below was used instead of the PTFE resin powder of Example 1.

[0353] Example 3

[0354] The air conditioner was operated by suction in the same manner as in Example 1 except that the PTFE resin powder of Example 3 (average particle size 5.8 μm) shown in Table 3 below was used instead of the PTFE resin powder of Example 1.

[0355] Example 4

[0356] The air conditioner was operated by suction in the same manner as in Example 1 except that the PTFE resin powder of Example 4 (average particle size 8.6 μm) shown in Table 3 below was used instead of the PTFE resin powder of Example 1.

[0357] Example 5

[0358] The air conditioner was operated by suction in the same manner as in Example 1 except that the PTFE resin powder of Example 5 (average particle size 6.2 μm) shown in Table 3 below was used instead of the PTFE resin powder of Example 1.

[0359] Example 6

[0360] The air conditioner was operated by suction in the same manner as in Example 1 except that the PTFE resin powder of Example 6 (average particle size 7.1 μm) shown in Table 3 below was used instead of the PTFE resin powder of Example 1.

[0361] Example 7

[0362] The air conditioner was operated by suction in the same manner as in Example 1 except that the PTFE resin powder of Example 7 (average particle size 4.3 μm) shown in Table 3 below was used instead of the PTFE resin powder of Example 1.

[0363] Comparative Example 1

[0364] The air conditioner was operated by suction in the same manner as in Example 1 except that the PTFE resin powder of Comparative Example 1 (L-2 manufactured by Daikin Industries, Ltd., average particle size 1.3 μm) shown in Table 3 below was used instead of the PTFE resin powder of Example 1.

[0365] Comparative Example 2

[0366] The air conditioner was operated by suction in the same manner as in Example 1 except that the PTFE resin powder of Comparative Example 2 (8N manufactured by Kitamura, average particle size 4.3 μm) shown in Table 3 below was used instead of the PTFE resin powder of Example 1.

[0367] Comparative Example 3

[0368] The air conditioner was operated by suction in the same manner as in Example 1 except that the PTFE resin powder of Comparative Example 3 (manufactured by Heroflon, 5GR, average particle size 6.0 μm) shown in Table 3 below was used instead of the PTFE resin powder of Example 1.

[0369] The particle size distribution and refrigerant leakage rate measurement results of the resin powder and resin pellets used in Examples and Comparative Examples are shown in Tables 3 and 4 below.

[0370] [Table 3]

[0371]

[0372] [Table 4]

[0373]

[0374] As is clear from Table 4, when the resin particles having a specific particle size distribution of the present invention are used, leakage of the refrigerant can be suppressed more efficiently.

[0375] Industrial Applicability

[0376] The refrigeration cycle device, refrigeration oil and refrigerant leakage preventer of the present invention are very suitable for suppressing or preventing refrigerant leakage.

Claims

1. A refrigeration oil, characterized in that: Contains D with 2.0μm to 10.0μm 50 and D of 4.0 to 14.0 90 / D 10 of resin particles.

2. The refrigeration oil according to claim 1, characterized in that: The resin particles have a standard deviation of 3.0 μm to 8.0 μm.

3. The refrigeration oil according to claim 1 or 2, characterized in that: The resin particles are fluorine-containing resin particles.

4. The refrigeration oil according to claim 3, characterized in that: The fluorine-containing resin particles are polytetrafluoroethylene particles.

5. A working fluid for a refrigerator, characterized in that: The refrigerator working fluid contains refrigerator oil and a refrigerant composition. The refrigerating machine oil contains D having a particle size of 2.0 μm to 10.0 μm. 50 and D of 4.0 to 14.0 90 / D 10 Polytetrafluoroethylene particles, The refrigerator working fluid further contains an ultraviolet fluorescent dye.

6. The working fluid for a refrigerator according to claim 5, characterized in that: The polytetrafluoroethylene particles have a standard deviation of 3.0 μm to 8.0 μm.

7. The working fluid for a refrigerator according to claim 5 or 6, characterized in that: The ultraviolet fluorescent dye is selected from naphthalimide, coumarin, anthracene, phenanthrene, xanthene, thioxanthene, benzoxanthene and fluorescein and their derivatives.

8. A refrigeration cycle device, characterized in that: A refrigerator working fluid comprising the refrigerator working fluid according to any one of claims 5 to 7.

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