Refrigeration oil composition and refrigeration mixture

Abstract

The present invention provides a refrigeration oil composition having an incompatible region in which hydrocarbon refrigerants are incompatible within the temperature range expected for a refrigeration cycle. [Solution] A refrigeration oil composition for use with a refrigerant containing a hydrocarbon refrigerant, wherein the base oil consists solely of synthetic oil, and the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1). [Case 1] JPEG0007909676000018.jpg16103 [In the above general formula (1), R 1 and R 2 One of them is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0. However, 0

Description

[Technical Field]

[0001] This invention relates to refrigeration oil compositions and mixtures for refrigeration systems. In this specification, "refrigeration mixture" refers to a mixture of "refrigeration oil composition" and "refrigerant." [Background technology]

[0002] For example, refrigerators such as compression refrigerators generally include at least a compressor, a condenser, an expansion mechanism (e.g., an expansion valve), and an evaporator, and have a structure in which a refrigerator mixture circulates within a sealed system. Various refrigerants, such as saturated fluorinated hydrocarbon compounds (HFCs) and unsaturated fluorinated hydrocarbon compounds (HFOs), have been considered for use in refrigerators, including compression refrigerators. In recent years, the use of hydrocarbon-based refrigerants has also been considered from the perspective of reducing environmental impact by significantly reducing the global warming potential (GWP) (Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2004-043611 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, when hydrocarbon refrigerants are mixed with refrigeration oil compositions to form a refrigeration mixture, the hydrocarbon refrigerants tend to dissolve easily in the refrigeration oil composition, which can reduce the viscosity of the refrigeration mixture. This decrease in viscosity can cause problems such as poor lubrication in the compressor and other components of the refrigeration system. Therefore, the inventors diligently studied how to solve this problem. As a result, they came up with the idea that the above problem can be solved by creating a refrigeration oil composition that is incompatible with hydrocarbon refrigerants in a specific temperature range.

[0005] The present invention is based on the inventors' idea and aims to provide a refrigeration oil composition having an incompatible region in which hydrocarbon refrigerants are incompatible in the temperature range assumed for a refrigeration cycle, and a refrigeration mixture containing the refrigeration oil composition. [Means for solving the problem]

[0006] According to the present invention, the following [1] to [4] are provided. [1] A refrigeration oil composition used in refrigerants containing hydrocarbon refrigerants, The base oil consists solely of synthetic oils. A refrigeration oil composition wherein the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1). [ka] [In the above general formula (1), R 1 and R 2 One of them is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0. However, 0 <m / n≦7 / 3である。] [2] A mixture for a refrigerator containing the refrigerant oil composition described in [1] above and a refrigerant containing a hydrocarbon refrigerant. [3] A method of using a refrigeration oil composition, A method for using a refrigeration oil composition, wherein the base oil consists solely of synthetic oil, and the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1), and the refrigeration oil composition is circulated in an immiscible state with a hydrocarbon refrigerant in at least a portion of the refrigeration system. [ka] [In the above general formula (1), R 1 and R 2 One of them is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0. However, 0 <m / n≦7 / 3である。] [4] A method for producing a refrigeration oil composition used in refrigerants containing hydrocarbon refrigerants, The process includes blending only synthetic oils as the base oil. A method for producing a refrigeration oil composition, wherein the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1). [ka] [In the above general formula (1), R 1 and R 2 One of them is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0. However, 0 <m / n≦7 / 3である。] [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a refrigeration oil composition having an incompatible region in which hydrocarbon refrigerants are incompatible within the temperature range assumed for a refrigeration cycle, and further, a mixture for refrigeration containing the refrigeration oil composition. [Modes for carrying out the invention]

[0008] The upper and lower limits of the numerical ranges described herein can be combined in any way. For example, if the numerical ranges "A to B" and "C to D" are described, the numerical ranges "A to D" and "C to B" are also included within the scope of the present invention. Furthermore, unless otherwise specified, the numerical range "lower limit to upper limit" described herein means that the value is greater than or equal to the lower limit and less than or equal to the upper limit. Furthermore, in this specification, the numerical values ​​in the examples are values ​​that can be used as upper or lower limits. In the following explanation, "polyalkylene glycol compounds" may be abbreviated as "PAG compounds."

[0009] [Aspects of refrigerant oil composition] The refrigeration oil composition of this embodiment is a refrigeration oil composition used for refrigerants containing hydrocarbon refrigerants, The base oil consists solely of synthetic oils. The synthetic oil is a refrigeration oil composition containing a polyalkylene glycol compound (A) represented by the following general formula (1). [ka] [In the above general formula (1), R 1 and R 2 One of them is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0. However, 0 <m / n≦7 / 3である。]

[0010] The inventors of the present invention conducted diligent research to solve the above problems. As a result, they discovered that the PAG compound (A) represented by the above general formula (1) has an incompatible region in the temperature range assumed for a refrigeration cycle in which hydrocarbon refrigerants are incompatible. After further investigations, they completed the present invention.

[0011] Although the mechanism by which the effects of the present invention are achieved is not yet clear, it can be inferred, for example, as follows: It is inferred that the PAG compound (A) represented by the above general formula (1) has a molecular structure that is well-balanced for achieving the above objectives. Furthermore, according to the present invention, it is possible to suppress the compatibility of hydrocarbon refrigerants with refrigeration oil compositions, which may also have the secondary effect of reducing the amount of highly flammable hydrocarbon refrigerants used.

[0012] In the refrigerant oil composition of the present embodiment, the PAG-based compound (A) functions as a base oil. Here, the refrigerant oil composition of the present embodiment may be composed only of the PAG-based compound (A), but may contain other components other than the PAG-based compound (A) as long as the effects of the present invention are not impaired. In the refrigerant oil composition of the present embodiment, the content of the PAG-based compound (A) is preferably 90% by mass or more, more preferably 95% by mass or more, and still more preferably 97% by mass or more based on the total amount (100% by mass) of the refrigerant oil composition.

[0013] Hereinafter, the components and the like contained in the refrigerant oil composition of the present embodiment will be described in detail.

[0014] <PAG-based compound (A)> The refrigerant oil composition of the present embodiment contains a PAG-based compound (A). The PAG-based compound (A) is one or more selected from the compounds represented by the following general formula (1). [Chemical formula]

[0015] In the above general formula (1), one of R 1 and R 2 is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers of 0 or more. However, 0 < m / n ≤ 7 / 3.

[0016] R 1 and R 2 The carbon number of the alkyl group that can be selected as either one of them may be 1 to 3 as described above, but from the viewpoint of improving the effects of the present invention, it is preferably 1 to 2, and more preferably 1 (that is, one of R 1 and R 2 is a methyl group).

[0017] In the above general formula (1), E is an ethylene group and P is a propylene group. Therefore, in the above general formula (1), "EO" means an oxyethylene group and "PO" means an oxypropylene group.

[0018] In the above general formula (1), m and n are numbers of 0 or more. In this specification, the value of m is the average value (average added mole number) of the number of EO units. The value of n is the average value (average added mole number) of the number of PO units. Here, from the viewpoint of improving the effects of the present invention and making it easier to adjust the viscosity of the PAG-based compound (A) within an appropriate range, the value of m + n is preferably 1 to 200, more preferably 3 to 150, and still more preferably 5 to 120.

[0019] In the above general formula (1), 0 < m / n ≤ 7 / 3. Therefore, the PAG-based compound (A) represented by the above general formula (1) contains both an oxyethylene group and an oxypropylene group. And when m / n is within the above range, the PAG-based compound (A) has a non-compatible region where a hydrocarbon-based refrigerant is not compatible in the temperature region assumed as a refrigeration cycle. Here, the range of m / n is preferably 1 / 9 ≤ m / n ≤ 6 / 4, more preferably 2 / 8 ≤ m / n ≤ 5.5 / 4.5, and still more preferably 2.5 / 7.5 ≤ m / n ≤ 5 / 5. When m / n is within the above range, even when the proportion of the refrigerating machine oil composition is increased in the mixture for a refrigerating machine of the refrigerating machine oil composition and a hydrocarbon-based refrigerant, it is possible to easily secure a non-compatible region where the hydrocarbon-based refrigerant is not compatible.

[0020] <Kinematic viscosity of PAG-based compound (A)> From the viewpoint of ensuring good lubricity in the sliding part such as the compressor of the refrigerating machine, the kinematic viscosity of the PAG-based compound (A) at 40°C is preferably 5 mm 2 / s or more, more preferably 7 mm 2 / s or more, still more preferably 10 mm 2 / s or more. Also, from the viewpoint of oil return, it is preferably 150 mm 2 / s or less, more preferably 140 mm 2 / s or less, even more preferably 120 mm 2 / s or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, preferably 5 mm 2 / s to 150 mm 2 / s, more preferably 7 mm 2 / s to 140 mm 2 / s, even more preferably 10 mm 2 / s to 120 mm 2 / s.

[0021] The kinematic viscosity of the PAG-based compound (A) at 100 °C is preferably 1 mm 2 / s or more, more preferably 1.5 mm 2 / s or more, even more preferably 2 mm 2 / s or more. Also, from the viewpoint of oil return, preferably 70 mm 2 / s or less, more preferably 50 mm 2 / s or less, even more preferably 40 mm 2 / s or less. The upper and lower limit values of these numerical ranges can be arbitrarily combined. Specifically, preferably 1 mm 2 / s to 70 mm 2 / s, more preferably 1.5 mm 2 / s to 50 mm 2 / s, even more preferably 2 mm 2 / s to 40 mm 2 / s.

[0022] In this specification, the kinematic viscosity of the PAG-based compound (A) means the value measured in accordance with JIS K2283:2000.

[0023] <Other synthetic oils other than the PAG-based compound (A)> The refrigerant oil composition of this embodiment consists only of synthetic oil as the base oil. By using only synthetic oils as the base oil, the dissolution of hydrocarbon refrigerants into the refrigeration oil composition is suppressed, thereby preventing a decrease in the viscosity of the refrigeration mixture.

[0024] Herein, the refrigeration oil composition of this embodiment may contain synthetic oils other than PAG compound (A) as synthetic oils. Other synthetic oils besides PAG compounds (A) include polyvinyl ethers; polyalkylene glycols that do not fall under PAG compounds (A); copolymers of polyalkylene glycols or their monoethers with polyvinyl ethers; polyol esters; polyesters; polycarbonates; and the like. Synthetic oils may be used individually or in combination of two or more types.

[0025] Furthermore, from the viewpoint of improving the effects of the present invention, it is preferable that the content of synthetic oils other than PAG compound (A) is low. Specifically, the content of synthetic oils other than PAG compound (A) is preferably less than 100 parts by mass, more preferably less than 50 parts by mass, even more preferably less than 30 parts by mass, even more preferably less than 10 parts by mass, even more preferably less than 1 part by mass, even more preferably less than 0.1 parts by mass, and even more preferably no synthetic oils other than PAG compound (A) per 100 parts by mass of PAG compound (A).

[0026] <Additives> The refrigeration oil composition of this embodiment may or may not contain additives, as long as they do not impair the effects of the present invention. Examples of additives include those commonly incorporated into refrigeration oil compositions. Examples of such additives include one or more selected from the group consisting of antioxidants, oxygen scavengers, acid scavengers, extreme pressure agents, oiliness agents, metal deactivators, and defoaming agents. The total content of these additives is preferably 0% to 10% by mass, more preferably 0.01% to 5% by mass, and even more preferably 0.1% to 3% by mass, based on the total amount (100% by mass) of the refrigerant oil composition.

[0027] (Antioxidant) Examples of antioxidants include phenolic antioxidants such as 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, and 2,2'-methylenebis(4-methyl-6-tert-butylphenol), and amine-based antioxidants such as phenyl-α-naphthylamine and N,N'-diphenyl-p-phenylenediamine. Furthermore, antioxidants may be used individually or in combination of two or more types.

[0028] (Oxygen scavenger) Examples of oxygen scavengers include aliphatic unsaturated compounds and terpenes containing double bonds. The above aliphatic unsaturated compounds are preferably unsaturated hydrocarbons, specifically olefins; and polyenes such as dienes and trienes. As for olefins, α-olefins such as 1-tetradecene, 1-hexadecene, and 1-octadecene are preferred from the viewpoint of reactivity with oxygen. Other aliphatic unsaturated compounds besides those mentioned above include those with the molecular formula C, from the viewpoint of reactivity with oxygen. 20 H 30 Unsaturated aliphatic alcohols having a conjugated double bond, such as vitamin A ((2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohexe-1-yl)nonano-2,4,6,8-tetraen-1-ol), represented by O, are preferred. As for terpenes having a double bond, terpene hydrocarbons having a double bond are preferred, and from the viewpoint of reactivity with oxygen, α-farnesene (C 15 H 24 :3,7,11-trimethyldodeca-1,3,6,10-tetraene) and β-farnesene (C 15 H 24(7,11-dimethyl-3-methylidendodeca-1,6,10-triene) is more preferred. The oxygen scavenger may be used alone or in combination of two or more types.

[0029] (Acid scavenger) Examples of acid scavengers include phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, cyclohexene oxide, α-olefin oxide, and epoxy compounds such as epoxidized soybean oil. However, at least one selected from glycidyl esters, glycidyl ethers, and α-olefin oxides is preferably used as the acid scavenger. Examples of glycidyl ethers include linear, branched, or cyclic saturated or unsaturated aliphatic mono or polyhydric alcohols, or aromatic compounds containing one or more hydroxyl groups, typically having 3 to 30, preferably 4 to 24, and more preferably 6 to 16 carbon atoms. In the case of aliphatic polyhydric alcohols or aromatic compounds containing two or more hydroxyl groups, it is preferable that all hydroxyl groups are converted to glycidyl ethers in order to suppress an increase in the hydroxyl value for the stability of the lubricating oil composition. Among these, glycidyl ethers derived from linear, branched, or cyclic saturated aliphatic monoalcohols having 6 to 16 carbon atoms are particularly preferred. Examples of such glycidyl ethers include 2-ethylethyl glycidyl ether, isononyl glycidyl ether, caprinoyl glycidyl ether, lauryl glycidyl ether, and myristyl glycidyl ether. On the other hand, α-olefin oxides generally have 4 to 50 carbon atoms, preferably 4 to 24, and more preferably 6 to 16. Acid scavengers may be used individually or in combination of two or more types.

[0030] (Extreme pressure agent) Examples of extreme pressure agents include phosphorus-based extreme pressure agents such as phosphate esters, acidic phosphate esters, phosphite esters, acidic phosphite esters, and their amine salts. Among these phosphorus-based extreme pressure agents, tricresyl phosphate, trithiophenyl phosphate, tri(nonylphenyl) phosphate, dioleyl hydrogen phosphate, and 2-ethylhexyl diphenyl phosphate are particularly preferred in terms of extreme pressure properties and frictional characteristics. Furthermore, metal salts of carboxylic acids can be used as extreme pressure agents. The metal salts of carboxylic acids referred to here are preferably carboxylic acids having 3 to 60 carbon atoms, more preferably carboxylic acids having 3 to 30 carbon atoms, and particularly preferably metal salts of fatty acids having 12 to 30 carbon atoms. In addition, metal salts of dimer acids and trimer acids of the aforementioned fatty acids, as well as dicarboxylic acids having 3 to 30 carbon atoms, can be used. Of these, metal salts of fatty acids having 12 to 30 carbon atoms and dicarboxylic acids having 3 to 30 carbon atoms are particularly preferred. On the other hand, alkali metals or alkaline earth metals are preferred as the metals that make up the metal salt, and alkali metals are particularly optimal. Furthermore, as extreme pressure agents other than those mentioned above, examples of sulfur-based extreme pressure agents include sulfurized oils and fats, sulfurized fatty acids, sulfurized esters, sulfurized olefins, dihydrocarbyl polysulfides, thiocarbamates, thioterpenes, and dialkylthiodipropionates. Extreme pressure additives may be used individually or in combination of two or more types.

[0031] (Oily-based agent) Examples of oily agents include aliphatic saturated and unsaturated monocarboxylic acids such as stearic acid and oleic acid, polymerized fatty acids such as dimer acid and hydrogenated dimer acid, hydroxy fatty acids such as ricinoleic acid and 12-hydroxystearic acid, aliphatic saturated and unsaturated monoalcohols such as lauryl alcohol and oleyl alcohol, aliphatic saturated and unsaturated monoamines such as stearylamine and oleylamine, aliphatic saturated and unsaturated monocarboxylic acid amides such as lauric acid amide and oleic acid amide, and partial esters of polyhydric alcohols with aliphatic saturated or unsaturated monocarboxylic acids such as glycerin and sorbitol. Oily agents may be used individually or in combination of two or more types.

[0032] (metal deactivator) Examples of metal deactivators include copper deactivators such as N-[N,N'-dialkyl (alkyl group with 3 to 12 carbon atoms) aminomethyl]triazole. The metal deactivator may be used alone or in combination of two or more types.

[0033] (Antifoaming agent) Examples of defoaming agents include silicone oil and fluorinated silicone oil. The defoaming agent may be used alone or in combination of two or more types.

[0034] [Method for producing refrigerant oil composition] The method for producing the refrigeration oil composition of this embodiment is not particularly limited. For example, the method for producing the refrigerant oil composition of this embodiment is a method for producing a refrigerant oil composition used in refrigerants containing hydrocarbon refrigerants, This process includes blending only synthetic oils as the base oil. Furthermore, the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1). [ka] [In the above general formula (1), R 1 and R 2 One of them is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0. However, 0 <m / n≦7 / 3である。]

[0035] The method for producing the PAG compound (A) represented by the above general formula (1) is not particularly limited and can be produced by standard methods. Furthermore, in the manufacturing method of this embodiment, only synthetic oil containing the PAG compound (A) represented by the general formula (1) above is used as the base oil.

[0036] The method for producing the refrigeration oil composition of this embodiment may or may not further include a step of mixing PAG compound (A) with another synthetic oil other than PAG compound (A), and a step of mixing the above-mentioned additives. Furthermore, when incorporating the above-mentioned additive into PAG-based compound (A), the additive may be incorporated after being converted into a solution (dispersion) by adding a diluent oil or the like. In addition, in the above general formula (1), R 1 , R 2 The preferred ranges for m, n, and m / n are as described above in the explanation of PAG compound (A).

[0037] [Physical properties of refrigeration oil compositions] <Kinematic viscosity of refrigerant oil composition> The kinematic viscosity of the refrigeration oil composition at 40°C is preferably 5 mm, from the viewpoint of ensuring good lubrication in sliding parts such as the compressor of the refrigeration unit. 2 / s or more, more preferably 7mm 2 / s or more, more preferably 10mm 2 It is 150 mm or more. Also, from the viewpoint of oil return, it is preferable. 2 / s or less, more preferably 140 mm 2 / s or less, more preferably 120 mm 2 It is less than or equal to / s. The upper and lower limits of these numerical ranges can be combined in any way. Specifically, 5 mm is preferred. 2 / s~150mm 2 / s, more preferably 7mm 2 / s~140mm 2 / s, more preferably 10 mm 2 / s~120mm 2 It is / s.

[0038] From the viewpoint of ensuring good lubrication in sliding parts such as the compressor of the refrigeration unit, the kinematic viscosity of the refrigeration oil composition at 100°C is preferably 1 mm. 2 / s or more, more preferably 1.5 mm 2 / s or more, more preferably 2mm 2 It is 1 / s or more. Also, from the viewpoint of oil return, 70mm is preferable.2 / s or less, more preferably 50mm 2 / s or less, more preferably 40mm 2 It is less than or equal to / s. The upper and lower limits of these numerical ranges can be combined in any way. Specifically, 1 mm is preferred. 2 / s~70mm 2 / s, more preferably 1.5mm 2 / s~50mm 2 / s, more preferably 2mm 2 / s~40mm 2 It is / s.

[0039] In this specification, the kinematic viscosity of the refrigeration oil composition refers to the value measured in accordance with JIS K2283:2000.

[0040] <Incompatibility> The incompatibility of a refrigerant oil composition with hydrocarbon refrigerants means that neither the low-temperature two-phase separation temperature nor the high-temperature two-phase separation temperature falls within the temperature range of -50°C to 80°C, which is assumed to be the temperature range for a refrigeration cycle, and that the hydrocarbon refrigerant in the refrigerant oil composition is incompatible and separates within the range of -50°C to 80°C.

[0041] [Mixture for refrigerator] The above-mentioned refrigeration oil composition is mixed with a refrigerant containing a hydrocarbon-based refrigerant and used as a refrigeration mixture. In other words, the mixture for the refrigeration unit contains the above-mentioned refrigeration oil composition and a refrigerant containing a hydrocarbon-based refrigerant. The following explains refrigerants.

[0042] <Refrigerant> (Hydrogen-based refrigerants) The refrigerant used in this embodiment is a refrigerant that includes hydrocarbon-based refrigerants. The hydrocarbon refrigerant is preferably a hydrocarbon having 1 to 8 carbon atoms, more preferably a hydrocarbon having 1 to 5 carbon atoms, and even more preferably a hydrocarbon having 3 to 5 carbon atoms. When the number of carbon atoms is 8 or less, the boiling point of the refrigerant does not become too high, making it preferable as a refrigerant. The hydrocarbon refrigerant is one or more selected from the group consisting of methane, ethane, ethylene, propane (R290), cyclopropane, propylene, n-butane, isobutane (R600a), 2-methylbutane, n-pentane, isopentane, cyclopentaneisobutane, and n-hexane. Hydrocarbon refrigerants may be used individually or in combination of two or more types.

[0043] (Other refrigerants) In this embodiment, the refrigerant may be a mixed refrigerant that includes, as necessary, other refrigerants in addition to a hydrocarbon refrigerant. Other refrigerants include, for example, one or more selected from saturated fluorinated hydrocarbon refrigerants, unsaturated fluorinated hydrocarbon refrigerants, carbon dioxide, and ammonia. The following describes saturated fluorinated hydrocarbon refrigerants and unsaturated fluorinated hydrocarbon refrigerants.

[0044] -Saturated fluorinated hydrocarbon refrigerant- The saturated fluorinated hydrocarbon refrigerant is preferably a fluoride of an alkane having 1 to 4 carbon atoms, more preferably a fluoride of an alkane having 1 to 3 carbon atoms, and even more preferably a fluoride of an alkane (methane or ethane) having 1 or 2 carbon atoms. Examples of methane or ethane fluorides include trifluoromethane (R23), difluoromethane (R32), 1,1-difluoroethane (R152a), 1,1,1-trifluoroethane (R143a), 1,1,2-trifluoroethane (R143), 1,1,1,2-tetrafluoroethane (R134a), 1,1,2,2-tetrafluoroethane (R134), and 1,1,1,2,2-pentafluoroethane (R125). These may be used individually or in combination of two or more types.

[0045] -Unsaturated fluorinated hydrocarbon refrigerants- Examples of unsaturated fluorinated hydrocarbon refrigerants include compounds represented by the following general formula (3). C x F y H z ...(3) [In the general formula (3) above, x is an integer between 2 and 6, y is an integer between 1 and 11, and z is an integer between 1 and 11, and the molecule has one or more carbon-carbon unsaturated bonds.]

[0046] The general formula (3) above represents the types and number of elements in the molecule, specifically representing unsaturated fluorinated hydrocarbon compounds with 2 to 6 carbon atoms. Unsaturated fluorinated hydrocarbon compounds with 2 to 6 carbon atoms possess the physical and chemical properties, such as boiling point, freezing point, and latent heat of vaporization, required for use as a refrigerant. In the above general formula (3), C x The bonding configuration of the x carbon atoms represented by can be a single carbon-carbon bond, a carbon-carbon double bond, or other unsaturated bonds. From the viewpoint of stability, a carbon-carbon double bond is preferred, and an unsaturated fluorinated hydrocarbon compound has one or more unsaturated bonds such as a carbon-carbon double bond in its molecule, preferably one in number. That is, C x It is more preferable that at least one of the bond configurations of the x carbon atoms represented by is a carbon-carbon double bond.

[0047] Preferred unsaturated fluorinated hydrocarbon compounds include, for example, fluorides of linear or branched chain olefins having 2 to 6 carbon atoms or cyclic olefins having 4 to 6 carbon atoms. Specifically, examples include ethylene fluoride with 1 to 3 fluorine atoms, propene fluoride with 1 to 5 fluorine atoms, butene fluoride with 1 to 7 fluorine atoms, pentene fluoride with 1 to 9 fluorine atoms, hexene fluoride with 1 to 11 fluorine atoms, cyclobutene fluoride with 1 to 5 fluorine atoms, cyclopentene fluoride with 1 to 7 fluorine atoms, and cyclohexene fluoride with 1 to 9 fluorine atoms. Among these, propene fluorides are preferred, and propene with 3 to 5 fluorine atoms introduced is more preferred. Specifically, one or more selected from 1,3,3,3-tetrafluoropropene (R1234ze), 2,3,3,3-tetrafluoropropene (R1234yf), and 1,2,3,3-tetrafluoropropene (R1234ye) are preferred, with 2,3,3,3-tetrafluoropropene (R1234yf) being more preferred. Unsaturated fluorinated hydrocarbon refrigerants may be used individually or in combination of two or more types.

[0048] (Content of hydrocarbon refrigerants in the refrigerant) In this embodiment, the refrigerant includes a hydrocarbon refrigerant. The hydrocarbon refrigerant content is preferably 20% to 100% by mass, more preferably 30% to 100% by mass, even more preferably 40% to 100% by mass, even more preferably 50% to 100% by mass, even more preferably 60% to 100% by mass, even more preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, even more preferably 90% to 100% by mass, and even more preferably 100% by mass, based on the total amount of refrigerant.

[0049] (Amount of refrigerant and refrigerant oil composition used) In the refrigerator mixture of this embodiment, the amounts of refrigerant and refrigerant oil composition used are preferably 5 / 95 to 90 / 10, more preferably 10 / 90 to 85 / 15, and even more preferably 10 / 90 to 80 / 20, in terms of the mass ratio of the refrigerant oil composition to the refrigerant [(refrigerant oil composition) / (refrigerant)], from the viewpoint of improving the effects of the present invention and making it easier to obtain a suitable refrigeration capacity in the refrigerator. Furthermore, the mass ratio of the refrigerant oil composition to the hydrocarbon refrigerant [(refrigerant oil composition) / (hydrocarbon refrigerant)] is preferably 5 / 95 to 90 / 10, more preferably 10 / 90 to 85 / 15, and even more preferably 10 / 90 to 80 / 20.

[0050] [Uses of refrigerant oil compositions and refrigerant mixtures] The refrigeration oil composition and refrigeration mixture of this embodiment are preferably used in, for example, refrigeration systems, hot water supply systems, or heating systems. Specifically, examples include air conditioners, refrigerators, freezers, vending machines, and display cases. Examples of air conditioners include car air conditioners such as open-type car air conditioners and electric car air conditioners; gas heat pump (GHP) air conditioners; and the like.

[0051] In this embodiment, even if the refrigeration oil composition is incompatible with the hydrocarbon refrigerant, it can be returned to the compressor via an oil separator, thus maintaining an incompatible state with the hydrocarbon refrigerant. Therefore, the present invention provides the following method of use. (1) Usage method 1 A method for using a refrigeration oil composition, A method for using a refrigeration oil composition, wherein the base oil consists solely of synthetic oil, and the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1), and the refrigeration oil composition is circulated in an immiscible state with a hydrocarbon refrigerant in at least a portion of the refrigeration system. [ka] [In the above general formula (1), R 1 and R 2 One of them is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0. However, 0 <m / n≦7 / 3である。] (2) Usage mode 2 A method for using a refrigeration oil composition, A method for using a refrigeration oil composition, wherein the base oil consists solely of synthetic oil, and the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1), the refrigeration oil composition is circulated in a state of incompatibility with the hydrocarbon refrigerant in at least a portion of the compressor within the refrigeration system. [ka] [In the above general formula (1), R 1 and R 2 One of them is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0. However, 0 <m / n≦7 / 3である。]

[0052] In the embodiments of the methods of use described in (1) and (2) above, the R of the PAG compound (A) represented by the general formula (1) above 1 , R 2 The preferred ranges of m, n, and m / n are as described above in the explanation of the PAG compound (A) contained in the synthetic oil in the refrigeration oil composition of this embodiment. Furthermore, in the embodiments of the usage methods described in (1) and (2) above, for example, the mass ratio of the refrigerant oil composition to the refrigerant (hydrocarbon refrigerant) [(refrigerant oil composition) / (refrigerant (hydrocarbon refrigerant))] under the two-phase separation temperature measurement conditions described in the examples later is preferably 5 / 95 to 90 / 10, more preferably 10 / 90 to 85 / 15, and even more preferably 10 / 90 to 80 / 20. In the embodiments of the methods of use described in (1) and (2) above, for example, the mass ratio of the refrigerant oil composition to the refrigerant (hydrocarbon refrigerant) [(refrigerant oil composition) / (refrigerant (hydrocarbon refrigerant))] under the two-phase separation temperature measurement conditions described in the examples later described below may be preferably 5 / 95 to 70 / 30, more preferably 5 / 95 to 65 / 35, even more preferably 5 / 95 to 60 / 40, and even more preferably 10 / 90 to 55 / 45 within the refrigeration cycle. Furthermore, in the embodiment of the method of use described in (1) above, the temperature range within the refrigeration system when the refrigeration oil composition is circulated within the refrigeration system in an immiscible state with the hydrocarbon refrigerant is preferably -50°C to 80°C. Furthermore, in the usage method embodiment described in (2) above, the temperature range inside the compressor of the refrigerator is preferably -50°C to 80°C.

[0053] [One aspect of the present invention provided] In one aspect of the present invention, the following [1] to

[10] are provided. [1] A refrigeration oil composition used in refrigerants containing hydrocarbon refrigerants, The base oil consists solely of synthetic oils. A refrigeration oil composition wherein the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1). [ka] [In the above general formula (1), R 1 and R 2 One of them is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0. However, 0 <m / n≦7 / 3である。] [2] In the above general formula (1), R 1 and R 2 The refrigeration oil composition according to [1] above, wherein one of the groups is a methyl group. [3] The refrigerant oil composition according to [1] or [2] above, wherein the content of the polyalkylene glycol compound (A) is 90% by mass or more on a total basis of the refrigerant oil composition. [4] The kinematic viscosity at 40°C is 5 mm 2 / s~150mm 2 A refrigeration oil composition according to any of the above [1] to [3], wherein the ratio is / s. [5] A refrigeration oil composition according to any of [1] to [4] above, wherein in the general formula (1), 1 / 9 ≤ m / n ≤ 6 / 4. [6] The refrigeration oil composition according to any one of [1] to [5] above, wherein the hydrocarbon refrigerant is a hydrocarbon having 1 to 8 carbon atoms. [7] A mixture for a refrigerator containing the refrigerant oil composition described in any of [1] to [6] above and a refrigerant containing a hydrocarbon refrigerant. [8] A method of using a refrigerant oil composition, A method for using a refrigeration oil composition, wherein the base oil consists solely of synthetic oil, and the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1), and the refrigeration oil composition is circulated in an immiscible state with a hydrocarbon refrigerant in at least a portion of the refrigeration system. [ka] [In the general formula (1), one of R 1 and R 2 is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers of 0 or more. However, 0 < m / n ≦ 7 / 3.] [9] A method for using a refrigerant oil composition, comprising: circulating a refrigerant oil composition, in which the base oil consists only of a synthetic oil containing a polyalkylene glycol compound (A) represented by the following general formula (1), in at least a part of a compressor in a refrigeration system in a state incompatible with the hydrocarbon refrigerant. [Chemical formula] [In the general formula (1), one of R 1 and R 2 is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers of 0 or more. However, 0 < m / n ≦ 7 / 3.]

[10] A method for producing a refrigerant oil composition used for a refrigerant containing a hydrocarbon refrigerant, comprising: a step of blending only a synthetic oil as the base oil, and the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1). [Chemical formula] [In the general formula (1), one of R 1 and R 2 is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers of 0 or more. However, 0 < m / n ≦ 7 / 3.] [Examples]

[0054] The present invention will be specifically described by the following embodiments. However, the present invention is not limited to the following embodiments.

[0055] [Methods for measuring various physical properties] The properties of each raw material used in each example and comparative example, as well as the properties of each refrigeration oil composition in each example and comparative example, were measured according to the following procedure. (1)Kinematic viscosity The kinematic viscosity at 40°C and 100°C was measured in accordance with JIS K2283:2000.

[0056] [Examples 1-3, Comparative Examples 1-2] In Examples 1-3 and Comparative Examples 1-2, refrigeration oil compositions were prepared using the following PAG compounds or mixtures of the following PAG compounds as base oils and subjected to the evaluation described later. The refrigeration oil composition used consisted of 98.3% by mass of PAG compounds and 1.7% by mass of additives. The additives included the following antioxidants, extreme pressure agents, acid scavengers, and defoamers. Due to the addition of additives, the kinematic viscosity of the refrigeration oil composition at 40°C was 1-2 mm higher than that of the PAG compounds at 40°C. 2 A slight decrease in / s occurs. • Antioxidant: 2,6-di-tert-butyl-p-cresol (DBPC) • Extreme pressure agent: Tricresyl phosphate (TCP) • Acid scavenger: 2-ethylhexylglycidyl ether • Defoaming agent: A solution of dimethyl silicone, a silicone-based defoaming agent, dissolved in diluted oil. Furthermore, the m and n values ​​of the PAG compounds described later were calculated from the number-average molecular weight (Mn) of the PAG compounds. The number-average molecular weight (Mn) of PAG compounds was measured using a gel permeation chromatography (GPC) instrument. For GPC measurement, two columns of "TSKgel SuperMultipore HZ-M" manufactured by Tosoh Corporation were sequentially connected and used. Tetrahydrofuran was used as the eluent, and measurement was carried out using a refractive index detector (RI detector) as the detector. The number average molecular weight (Mn) was determined using polystyrene as the standard sample.

[0057] <Example 1> PAG compound (A)-1a was used. In PAG compound (A)-1a, in the above general formula (1), R 1 and R 2 One of them is a methyl group and the other is a hydrogen atom. Also, m = 5.3, n = 47.7, and m / n = 1 / 9. The kinematic viscosity at 40°C is 100 mm 2 / s, and the kinematic viscosity at 100°C is 19.1 mm 2 / s.

[0058] <Example 2> PAG compound (A)-1b was used. In PAG compound (A)-1b, in the above general formula (1), R 1 and R 2 One of them is a methyl group and the other is a hydrogen atom. Also, m = 8.5, n = 19.8, and m / n = 3 / 7. The kinematic viscosity at 40°C is 32 mm 2 / s, and the kinematic viscosity at 100°C is 6.9 mm 2 / s.

[0059] <Example 3> PAG compound (A)-1c was used. In PAG compound (A)-1c, in the above general formula (1), R 1 and R 2 One of them is a methyl group and the other is a hydrogen atom. Also, m = 28, n = 28, and m / n = 5 / 5. The kinematic viscosity at 40°C is 100 mm 2 / s, and the kinematic viscosity at 100°C is 19.0 mm 2 / s.

[0060] <Comparative Example 1> PAG compound (A’)-1a was used. PAG compound (A')-1a is a compound in which R in the above general formula (1) 1 and R 2 This is a methyl group. Also, m=0, n=34, and m / n=0. The kinematic viscosity at 40°C is 32 mmHg. 2 kinematic viscosity at 100°C is 7.6 mm² / s. 2 The hydroxyl value is 11.1 mgKOH / g.

[0061] <Comparative Example 2> PAG compound (A')-1b was used. PAG compound (A')-1b is a compound in the above general formula (1) where R 1 and R 2 This is a methyl group. Also, m=0, n=70, and m / n=0. The kinematic viscosity at 40°C is 100 mm². 2 kinematic viscosity at 100°C is 20.9 mm² / s. 2 The hydroxyl value is 5.6 mgKOH / g.

[0062] <Evaluation: Evaluation of the compatibility between the refrigerant oil composition and the refrigerant (measurement of two-phase separation temperature)> Two-layer separation temperature measuring tubes (internal volume 10 mL) were filled with the refrigerant oil compositions of Examples 1 to 3 and the refrigerant (R290) in the various mixing ratios shown in Table 1, and then held in a constant temperature bath. Then, for samples in which the refrigerant oil composition and refrigerant (R290) were separated at room temperature (25°C), the temperature of the constant temperature bath was lowered from room temperature to -50°C at a rate of 1.0°C / min, and samples in which the refrigerant oil composition and refrigerant (R290) remained separated at -50°C were classified as "mismatched". Furthermore, for samples where the refrigerant oil composition and refrigerant were separated at room temperature (25°C), the temperature of the constant temperature bath was raised from room temperature to 80°C at a rate of 1.0°C / min, and the temperature at which the miscibility of the refrigerant oil composition and refrigerant (R290) was confirmed was defined as the "low-temperature separation temperature." Samples that remained separated even after raising the temperature to 80°C were defined as "immigrant." Samples in which the refrigerant oil composition and refrigerant (R290) became miscible during the process of raising the temperature to 80°C and remained miscible even after raising the temperature to 80°C were indicated as "80<" in Table 1. In other words, for these samples, the "high-temperature separation temperature" exists in the temperature range above 80°C. In Examples 1 to 3, "-" in Table 1 indicates a sample in which the refrigerant oil composition and refrigerant (R290) were compatible at room temperature.

[0063] For Comparative Examples 1 and 2, since the refrigerant oil composition and refrigerant (R290) were miscible at room temperature (25°C), the temperature of the constant temperature bath was lowered from room temperature to -50°C at a rate of 1.0°C / min for the samples that were miscible at room temperature, and the temperature at which separation occurred was defined as the "low-temperature separation temperature." Furthermore, samples that remained miscible even after being lowered to -50°C were defined as "miscible." Similarly, for samples that were miscible at room temperature, the "high-temperature separation temperature" was measured, and the temperature at which separation occurred was defined as the "high-temperature separation temperature." Samples that remained miscible even after being heated to 80°C were defined as "miscible." In Comparative Examples 1 and 2, "-" in Table 1 indicates that the measurement was not taken. Furthermore, the oil content percentage in Table 1 refers to the percentage of the refrigerant oil composition (unit: mass%) relative to the total amount of the refrigerant oil composition and refrigerant (100% by mass).

[0064] In this embodiment, samples with an oil content of 10% to 80% by mass that had an immiscible region within the temperature range of -50°C to 80°C were deemed acceptable. Samples with an oil content of 10% to 80% by mass that did not have an immiscible region within the temperature range of -50°C to 80°C were deemed unacceptable.

[0065] [Table 1]

[0066] From Table 1, the following can be seen. It can be seen that the PAG compounds of Examples 1 to 3, when mixed with the hydrocarbon refrigerant R290, have an incompatible region with the hydrocarbon refrigerant R290 in the range of -50°C to 80°C. In contrast, the PAG compounds of Comparative Examples 1 and 2, when mixed with the hydrocarbon refrigerant R290, do not exhibit an incompatible region with the hydrocarbon refrigerant R290 in the range of -50°C to 80°C.

Claims

1. A refrigeration oil composition used in refrigerants containing hydrocarbon refrigerants, The base oil consists solely of synthetic oils. A refrigeration oil composition wherein the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1). 【Chemistry 1】 [In the above general formula (1), R １ and R ２ One of them is a methyl group, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0, where 0 < m / n ≤ 7 / 3.

2. The refrigeration oil composition according to claim 1, wherein in the general formula (1), m + n is 1 to 200.

3. The refrigerant oil composition according to claim 1 or 2, wherein the content of the polyalkylene glycol compound (A) is 90% by mass or more on a total basis of the refrigerant oil composition.

4. The kinematic viscosity at 40°C is 5 mm ２ / s ~ 150mm ２ A refrigerant oil composition according to claim 1 or 2, wherein the ratio is / s.

5. The refrigeration oil composition according to claim 1 or 2, wherein in the general formula (1), 1 / 9 ≤ m / n ≤ 6 / 4.

6. The refrigeration oil composition according to claim 1 or 2, wherein the hydrocarbon refrigerant is a hydrocarbon having 1 to 8 carbon atoms.

7. A mixture for a refrigerator, comprising the refrigeration oil composition according to claim 1 or 2 and a refrigerant containing a hydrocarbon refrigerant.

8. A method for using a refrigeration oil composition, A method for using a refrigeration oil composition, wherein the base oil consists solely of synthetic oil, and the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1), and the refrigeration oil composition is circulated in an immiscible state with a hydrocarbon refrigerant in at least a portion of the refrigeration system. 【Chemistry 2】 [In the above general formula (1), R １ and R ２ One of the atoms is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0, where 0 < m / n ≤ 7 / 3.

9. A method for using a refrigeration oil composition, A method for using a refrigeration oil composition, wherein the base oil consists solely of synthetic oil, and the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1), the refrigeration oil composition is circulated in an immiscible state with a hydrocarbon refrigerant in at least a portion of the compressor within the refrigeration system. 【Transformation 3】 [In the above general formula (1), R １ and R ２ One of the atoms is an alkyl group having 1 to 3 carbon atoms, and the other is a hydrogen atom. E is an ethylene group, and P is a propylene group. m and n are numbers greater than or equal to 0, where 0 < m / n ≤ 7 / 3.

10. A method for producing a refrigeration oil composition used in refrigerants containing hydrocarbon refrigerants, The process includes blending only synthetic oils as the base oil. A method for producing a refrigeration oil composition, wherein the synthetic oil contains a polyalkylene glycol compound (A) represented by the following general formula (1). 【Chemistry 4】 [In the general formula (1), R １ and R ２ One of them is a methyl group and the other is a hydrogen atom. E is an ethylene group and P is a propylene group. m and n are numbers of 0 or more. However, 0 < m / n ≤ 7 / 3.]

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