Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
  • C09K5/02—Materials undergoing a change of physical state when used
  • C09K5/04—Materials undergoing a change of physical state when used the change of state being from liquid to vapour or vice versa
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M107/00—Lubricating compositions characterised by the base-material being a macromolecular compound
  • C10M107/20—Lubricating compositions characterised by the base-material being a macromolecular compound containing oxygen
  • C10M107/22—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • C10M107/24—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds containing monomers having an unsaturated radical bound to an alcohol, aldehyde, ketonic, ether, ketal or acetal radical
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M107/00—Lubricating compositions characterised by the base-material being a macromolecular compound
  • C10M107/20—Lubricating compositions characterised by the base-material being a macromolecular compound containing oxygen
  • C10M107/30—Macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • C10M107/32—Condensation polymers of aldehydes or ketones; Polyesters; Polyethers
  • C10M107/34—Polyoxyalkylenes
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/08—Resistance to extreme temperature
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2040/00—Specified use or application for which the lubricating composition is intended
  • C10N2040/30—Refrigerators lubricants or compressors lubricants

Definitions

• the present invention relates to a composition for refrigeration machines that contains a mixed refrigerant and a refrigeration oil.
• a refrigerator for example, a compression type refrigerator, is generally composed of at least a compressor, a condenser, an expansion mechanism (such as an expansion valve), an evaporator, etc., and has a structure in which a mixture of a refrigerant and a refrigerating machine oil (hereinafter also referred to as a "refrigerating machine composition") circulates within a sealed system.
• refrigerants for compression-type refrigerators fluorohydrocarbon compounds, which have a low environmental impact, have begun to be used in place of the hydrochlorofluorocarbons (HCFCs) that have been widely used in the past.
• HCFCs hydrochlorofluorocarbons
• HFCs saturated fluorohydrocarbon compounds
• R134a 1,1,1,2-tetrafluoroethane
• R32 difluoromethane
• R410A pentafluoroethane
• HFOs unsaturated fluorinated hydrocarbon compounds
• R1234ze 1,3,3,3-tetrafluoropropene
• R1234yf 2,3,3,3-tetrafluoropropene
• carbon dioxide as a refrigerant with a lower global warming potential (GWP) is also being considered.
• Patent Document 1 discloses a composition for refrigerators used as a refrigerant comprising a mixture of an unsaturated fluorohydrocarbon compound, a saturated fluorohydrocarbon compound, and carbon dioxide.
• Patent Document 1 considers the practical application of a mixed refrigerant containing carbon dioxide, but depending on the composition of the mixed refrigerant and the composition of the refrigeration oil, differences may occur in the thermal stability of the entire refrigeration composition containing the mixed refrigerant and the refrigeration oil.
• the present invention was made in consideration of the above problems, and aims to provide a composition for refrigerators that has excellent thermal stability and is a mixture of a mixed refrigerant containing carbon dioxide, which is a refrigerant with a low global warming potential, and a refrigeration oil.
• a composition for a refrigerating machine comprising a mixed refrigerant and a refrigerating machine oil containing a base oil
• the mixed refrigerant contains a fluorohydrocarbon compound and carbon dioxide, The content of the fluorohydrocarbon compound is less than 25 mass% based on the total amount of the mixed refrigerant
• the composition for a refrigerator wherein the base oil contains one or more selected from the group consisting of polyvinyl ethers and polyalkylene glycols.
• content of the fluorohydrocarbon compound is 3 mass% or more and 20 mass% or less based on the total amount of the mixed refrigerant.
• fluorohydrocarbon compound contains 70 mass % or more and 100 mass % or less of an unsaturated fluorohydrocarbon compound.
• content of the polyalkylene glycols is 90 mass% or more and 100 mass% or less based on the total amount of the base oil.
• composition for a refrigerator according to any one of the above [1] to [7], wherein a total content of the mixed refrigerant and the refrigerating machine oil in the composition for a refrigerator is 90 mass% or more and 100 mass% or less.
• a refrigerating machine oil for use with a mixed refrigerant containing a fluorohydrocarbon compound and carbon dioxide, the content of the fluorohydrocarbon compound being less than 25% by mass Contains a base oil, The base oil contains one or more selected from the group consisting of polyvinyl ethers and polyalkylene glycols.
• a method for producing a refrigerating machine composition comprising a step of mixing a mixed refrigerant with a refrigerating machine oil containing a base oil,
• the mixed refrigerant contains a fluorohydrocarbon compound and carbon dioxide
• the method for producing a composition for a refrigerating machine according to any one of the above [1] to [8], wherein the content of the fluorohydrocarbon compound is less than 25 mass% based on the total amount of the mixed refrigerant, and the base oil contains one or more selected from the group consisting of polyvinyl ethers and polyalkylene glycols.
• a refrigeration composition having excellent thermal stability which is a mixture of a refrigerant containing carbon dioxide, which is a refrigerant with a low global warming potential, and a refrigeration oil.
• lower and upper limits described in stages can be combined independently.
• the “preferable lower limit (10)” can be combined with the “more preferred upper limit (60)” to give “10 to 60.”
• the numerical values of "greater than or equal to,” “less than or equal to,” “less than,” and “more than” in the description of numerical ranges can be combined in any way.
• the composition for a refrigeration machine of the present embodiment is a composition for a refrigeration machine comprising a mixed refrigerant and a refrigeration oil containing a base oil, wherein the mixed refrigerant contains a fluorohydrocarbon compound and carbon dioxide, the content of the fluorohydrocarbon compound is less than 25 mass% based on the total amount of the mixed refrigerant, and the base oil contains one or more types selected from the group consisting of polyvinyl ethers and alkylene glycols. If the mixed refrigerant does not contain carbon dioxide, this is undesirable from the viewpoint of global warming potential.
• the thermal stability is also insufficient. Furthermore, even if the content of fluorohydrocarbon compounds in the mixed refrigerant is 25 mass% or more, the thermal stability is also insufficient.
• hydrocarbon group refers to a group consisting of only carbon atoms and hydrogen atoms.
• hydrocarbon group includes "aliphatic groups” consisting of straight or branched chains, “alicyclic groups” having one or more saturated or unsaturated carbon rings that do not have aromaticity, and “aromatic groups” having one or more aromatic rings that exhibit aromaticity, such as a benzene ring.
• number of ring carbon atoms refers to the number of carbon atoms among the atoms constituting the ring itself of a compound having a structure in which atoms are bonded in a ring.
• the carbon atoms contained in the substituent are not included in the number of ring carbon atoms.
• the number of ring atoms refers to the number of atoms constituting the ring itself of a compound having a structure in which atoms are bonded in a ring, and does not include atoms that do not constitute the ring (e.g., hydrogen atoms terminating the bonds of atoms constituting the ring) or atoms contained in the substituent when the ring is substituted with a substituent.
• examples of the substituent in the description of "substituted or unsubstituted” include an alkyl group having 1 to 10 carbon atoms (preferably 1 to 6, more preferably 1 to 4, and even more preferably 1 to 3) ; a cycloalkyl group having 3 to 10 ring carbon atoms (preferably 3 to 8, more preferably 4 to 6, and even more preferably 5 or 6) ; an aryl group having 6 to 18 ring carbon atoms (preferably 6 to 12) ; a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom); a cyano group; a nitro group; a hydroxy group; and an amino group.
• an alkyl group having 1 to 10 carbon atoms preferably 1 to 6, more preferably 1 to 4, and even more preferably 1 to 3
• a cycloalkyl group having 3 to 10 ring carbon atoms preferably 3 to 8, more preferably 4 to 6, and even more
• substituents may be further substituted with any of the aforementioned substituents.
• unsubstituted in the description "substituted or unsubstituted” means that the group is not substituted with these substituents and has a hydrogen atom bonded thereto.
• the mixed refrigerant contains a fluorohydrocarbon compound and carbon dioxide, and the content of the fluorohydrocarbon compound is less than 25 mass % based on the total amount of the mixed refrigerant.
• the mixed refrigerant will be described below.
• the fluorohydrocarbon compounds include saturated fluorohydrocarbon compounds (HFCs) and unsaturated fluorohydrocarbon compounds (HFOs).
• HFCs saturated fluorohydrocarbon compounds
• HFOs unsaturated fluorohydrocarbon compounds
• the fluorohydrocarbon compound preferably contains an unsaturated fluorohydrocarbon compound in an amount of 70 mass% or more and 100 mass% or less, more preferably 80 mass% or more and 100 mass% or less, and even more preferably 90 mass% or more and 100 mass% or less.
• the saturated fluorinated hydrocarbon compound (HFC) 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.
• fluoride of methane or ethane examples 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).
• difluoromethane and 1,1,1,2-tetrafluoroethane are preferred.
• These saturated fluorohydrocarbon compounds may be used alone or in combination of two or more.
• HFOs Unsaturated fluorinated hydrocarbon compounds
• HFO unsaturated fluorinated hydrocarbon compound
• examples of the unsaturated fluorinated hydrocarbon compound (HFO) include compounds having a carbon-carbon double bond, such as fluorinated linear or branched chain olefins having from 2 to 6 carbon atoms; and fluorinated cyclic olefins having from 4 to 6 carbon atoms.
• More specific examples include ethylene having 1 to 3 (preferably 3) fluorine atoms introduced, propene having 1 to 5 fluorine atoms introduced, butene having 1 to 7 fluorine atoms introduced, pentene having 1 to 9 fluorine atoms introduced, hexene having 1 to 11 fluorine atoms introduced, cyclobutene having 1 to 5 fluorine atoms introduced, cyclopentene having 1 to 7 fluorine atoms introduced, and cyclohexene having 1 to 9 fluorine atoms introduced.
• HFOs preferred is a fluoride of propene, more preferred is propene having 3 to 5 fluorine atoms introduced, and even more preferred is propene having 4 fluorine atoms introduced.
• HFO 1,2,3,3,3-pentafluoropropene (R1225ye), 2,3,3,3-tetrafluoropropene (R1234yf), 1,3,3,3-tetrafluoropropene (R1234ze), 1,2,3,3-tetrafluoropropene (R1234ye), 1,1,2-trifluoroethylene (R1123), cis-1,2-difluoroethylene (R1132(Z)), trans-1,2-difluoroethylene (R1132(E)), (Z)-1,1,1,4,4,4-hexafluoro-2-butene (R1336mzz(Z)), etc.
• HFOs one or more selected from the group consisting of R1234yf, R1234ze, R1123 and R1132(E) are preferred. These HFOs may be used alone or in combination of two or more thereof. An example of a combination of two or more HFOs is a combination of R1234yf and R1234ze.
• the content of the propene fluoride is, based on the total amount of HFO (100 mass%), preferably 50 mass% or more and 100 mass% or less, more preferably 70 mass% or more and 100 mass% or less, even more preferably 90 mass% or more and 100 mass% or less, and still more preferably 100 mass%.
• the HFO contained in the mixed refrigerant preferably includes at least one of R1234yf and R1234ze.
• the content of R1234yf and R1234ze in the HFO contained in the mixed refrigerant is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, still more preferably 90% by mass or more and 100% by mass or less, and still more preferably 100% by mass, based on the total amount of HFO (100% by mass).
• the mixed refrigerant contains a fluorohydrocarbon compound and carbon dioxide, but may also contain other refrigerants.
• Such other refrigerants are preferably natural refrigerants other than carbon dioxide.
• Natural refrigerants other than carbon dioxide examples include one or more selected from the group consisting of hydrocarbon refrigerants (HC) and ammonia. These natural refrigerants may be used alone or in combination of two or more.
• 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. If the carbon number is 8 or less, the boiling point of the refrigerant does not become too high, which is preferable as a refrigerant.
• the hydrocarbon refrigerant may be 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, and cyclopentane isobutane, and one of these may be used alone, or two or more may be used in combination.
• the mixed refrigerant is required to contain carbon dioxide in order to have a low global warming potential.
• the carbon dioxide content in the mixed refrigerant is preferably 50 mass% or more, more preferably 75 mass% or more, and even more preferably 80 mass% or more, and is preferably 97 mass% or less, based on the total amount of the mixed refrigerant.
• the content of the fluorohydrocarbon compound should be less than 25 mass% based on the total amount of the mixed refrigerant, and is preferably 20 mass% or less, and more preferably 15 mass% or less, and is preferably 3 mass% or more, and more preferably 5 mass% or more.
• the refrigeration oil contains a base oil containing one or more selected from the group consisting of polyvinyl ethers (hereinafter also referred to as "PVE") and polyalkylene glycols (hereinafter also referred to as "PAG").
• PVE polyvinyl ethers
• PAG polyalkylene glycols
• the content of the base oil is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, even more preferably 97% by mass or more and 100% by mass or less, and still more preferably 98% by mass or more and 100% by mass or less, based on 100% by mass of the total amount of the refrigerating machine oil.
• the base oil contained in the refrigerating machine oil is a base oil containing one or more kinds selected from the group consisting of polyvinyl ethers (PVE) and polyalkylene glycols (PAG). From the viewpoint of obtaining better thermal stability, the base oil preferably contains one or more types selected from the group consisting of PVEs.
• the content of one or more selected from the group consisting of PVE and PAG in 100% by mass of the total amount of the base oil is preferably 80% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, even more preferably 95% by mass or more and 100% by mass or less, and even more preferably 98% by mass or more and 100% by mass or less.
• the content of PAG in 100% by mass of the total amount of the base oil is preferably 80% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, even more preferably 95% by mass or more and 100% by mass or less, and even more preferably 98% by mass or more and 100% by mass or less.
• the PVE and PAG contained in the base oil will be described in order.
• the polyvinyl ethers (PVE) include polymers having one or more structural units derived from vinyl ether.
• the base oil may contain the PVE alone or in combination of two or more kinds.
• a polymer having one or more structural units derived from vinyl ether and having an alkyl group having 1 to 4 carbon atoms in the side chain is preferred.
• polymer (A1) having one or more structural units represented by the following general formula (A-1) is preferred.
• R 1a , R 2a , and R 3a each independently represent a hydrogen atom or a hydrocarbon group having from 1 to 8 carbon atoms.
• R 4a represents a divalent hydrocarbon group having from 2 to 10 carbon atoms.
• R 5a represents a hydrocarbon group having from 1 to 10 carbon atoms.
• r is the average value of the number of units represented by OR 4a and is a number of 0 to 10, preferably a number of 0 to 5, more preferably a number of 0 to 3, and even more preferably 0.
• the plurality of OR 4a's may be the same or different.
• the bond between the carbon atom (C) and --OR 5a in the general formula (A-1) is a single bond, and the carbon atom (C) and --OR 5a are directly bonded to each other.
• hydrocarbon groups having 1 to 8 carbon atoms that can be selected as R 1a , R 2a , and R 3a include alkyl groups such as methyl group, ethyl group, various propyl groups, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, and various octyl groups; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, and various dimethylcyclohexyl groups; aryl groups such as phenyl group, various methylphenyl groups, various ethylphenyl groups, and various dimethylphenyl groups; arylalkyl groups such as benzyl group, various phenylethyl groups, and various methylbenzyl groups; and the like.
• alkyl groups such as methyl group, ethyl group, various
• variable XXX groups includes all possible isomers of the XXX group.
• variant alkyl groups refers to “linear, branched or cyclic hydrocarbon groups”
• variant propyl groups refers to various propyl groups such as “n-propyl group, isopropyl group”
• variant butyl groups refers to various butyl groups such as "n-butyl group, sec-butyl group, isobutyl group, tert-butyl group, cyclobutyl group”.
• the number of carbon atoms in the hydrocarbon group which can be selected as R 1a , R 2a , and R 3a is preferably 1 or more and 6 or less, more preferably 1 or more and 4 or less, and even more preferably 1 or more and 3 or less.
• R 1a , R 2a , and R 3a each independently represent preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, even more preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and still more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
• R 1a , R 2a and R 3a may be the same or different.
• divalent hydrocarbon groups having 2 to 10 carbon atoms that can be selected as R 4a include divalent aliphatic groups such as ethylene group, 1,2-propylene group, 1,3-propylene group, various butylene groups, various pentylene groups, various hexylene groups, various heptylene groups, various octylene groups, various nonylene groups, and various decylene groups; alicyclic groups which are divalent residues of alicyclic compounds such as cyclohexane, methylcyclohexane, ethylcyclohexane, dimethylcyclohexane, and propylcyclohexane; divalent aromatic groups such as various phenylene groups, various methylphenylene groups, various ethylphenylene groups, various dimethylphenylene groups, and various naphthylenes; divalent alkyl aromatic groups having monovalent bonding sites at the alkyl group moiety and aromatic moiety of alkyl aromatic hydrocarbons such
• the hydrocarbon group that can be selected as R 4a preferably has 2 or more and 8 or less carbon atoms, more preferably 2 or more and 6 or less carbon atoms, and further preferably 2 or more and 4 or less carbon atoms.
• R 4a is preferably a divalent aliphatic group having 2 to 10 carbon atoms, preferably a divalent aliphatic group having 2 to 6 carbon atoms, and more preferably a divalent aliphatic group having 2 to 4 carbon atoms.
• hydrocarbon groups having 1 to 10 carbon atoms that can be selected as R 5a include alkyl groups such as methyl group, ethyl group, various propyl groups, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, and various decyl groups; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, various propylcyclohexyl groups, and various dimethylcyclohexyl groups; aryl groups such as phenyl group, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, and various naphthyl groups; and arylalkyl groups such
• R 5a is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms.
• the polymer (A1) preferably has a structural unit ( ⁇ 1) in which R 5a is an ethyl group.
• the content of the structural unit ( ⁇ 1) is preferably 60% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 80% by mass or more and 100% by mass or less, still more preferably 85% by mass or more and 100% by mass or less, and even more preferably 90% by mass or more and 100% by mass or less, based on the total amount (100% by mass) of structural units other than terminal structural units contained in the polymer (A1).
• the number of units (degree of polymerization) of the structural unit represented by general formula (A-1) may be appropriately set so that the hydroxyl value of the base oil (P) falls within the range of 15 mgKOH/g or less.
• the polymer (A1) may be a homopolymer having only one type of structural unit represented by general formula (A-1), or a copolymer having two or more types of such structural units.
• the copolymerization form of the copolymer is not particularly limited, and the copolymer may be a block copolymer, a random copolymer, or a graft copolymer.
• a monovalent group derived from a saturated hydrocarbon, ether, alcohol, ketone, amide, nitrile, or the like may be introduced into the terminal portion of the polymer (A1).
• one end of the polymer (A1) is preferably a group represented by the following general formula (A-1-i).
• R 6a , R 7a , and R 8a each independently represent a hydrogen atom or a hydrocarbon group having from 1 to 8 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having from 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, and even more preferably a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms.
• R 6a , R 7a and R 8a may be the same or different.
• Examples of the hydrocarbon group having 1 to 8 carbon atoms that can be selected as R 6a , R 7a , and R 8a include the same groups as those listed as the hydrocarbon groups having 1 to 8 carbon atoms that can be selected as R 1a , R 2a , and R 3a in general formula (A-1).
• R 9a represents a divalent hydrocarbon group having from 2 to 10 carbon atoms, preferably a divalent hydrocarbon group having from 2 to 8 carbon atoms, more preferably a divalent hydrocarbon group having from 2 to 6 carbon atoms, and even more preferably a divalent aliphatic group having from 2 to 4 carbon atoms.
• r1 represents the average number of units represented by OR 9a and is a number of 0 to 10, preferably a number of 0 to 5, more preferably a number of 0 to 3, and even more preferably 0.
• the plurality of OR 9a may be the same or different.
• the bond between the carbon atom (C) and --OR 10a in the general formula (A-1-i) is a single bond, and the carbon atom (C) and --OR 10a are directly bonded to each other.
• Examples of the divalent hydrocarbon group having 2 to 10 carbon atoms that can be selected as R 9a include the same as those listed as the divalent hydrocarbon group having 2 to 10 carbon atoms that can be selected as R 4a in general formula (A-1).
• R 10a represents a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrocarbon group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 8 carbon atoms.
• R 10a is more preferably an alkyl group having 1 to 6 carbon atoms, and when r1 is 1 or more, R 10a is more preferably an alkyl group having 1 to 4 carbon atoms.
• Examples of the hydrocarbon group having 1 to 10 carbon atoms that can be selected as R 10a include the same groups as those listed as the hydrocarbon group having 1 to 10 carbon atoms that can be selected as R 5a in general formula (A-1).
• one end is a group represented by general formula (A-1-i) and the other end is one selected from the group consisting of a group represented by general formula (A-1-i), a group represented by the following general formula (A-1-ii), a group represented by the following general formula (A-1-iii), and a group having an olefinically unsaturated bond.
• R 11a , R 12a , R 13a , R 18a , R 19a , and R 20a each independently represent a hydrogen atom or a hydrocarbon group having from 1 to 8 carbon atoms, preferably a hydrogen atom or a hydrocarbon group having from 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, and even more preferably a hydrogen atom or an alkyl group having from 1 to 3 carbon atoms.
• R 11a , R 12a , R 13a , R 18a , R 19a , and R 20a may be the same or different.
• Examples of the hydrocarbon group that may be selected as R 11a , R 12a , R 13a , R 18a , R 19a , and R 20a include the same groups as those listed as the hydrocarbon groups having 1 to 8 carbon atoms that may be selected as R 1a , R 2a , and R 3a in general formula (A-1).
• R 14a and R 16a each independently represent a divalent hydrocarbon group having from 2 to 10 carbon atoms, preferably a divalent hydrocarbon group having from 2 to 6 carbon atoms, more preferably a divalent aliphatic group having from 2 to 4 carbon atoms.
• Examples of the divalent hydrocarbon group that can be selected as R 14a and R 16a include the same divalent hydrocarbon groups that can be selected as R 4a in general formula (A-1).
• r2 and r3 each represent the average value of the number of units represented by OR 14a and OR 16a , respectively, and each independently represents a number of 0 or more and 10 or less, preferably a number of 0 or more and 5 or less, more preferably a number of 0 or more and 3 or less, and even more preferably 0.
• the plurality of OR 14a and the plurality of OR 16a may be the same or different.
• R 15a and R 17a each independently represent a hydrocarbon group having 1 to 10 carbon atoms, preferably a hydrocarbon group having 1 to 8 carbon atoms, and more preferably an alkyl group having 1 to 8 carbon atoms.
• R 15a is more preferably an alkyl group having 1 to 6 carbon atoms
• R 15a is more preferably an alkyl group having 1 to 4 carbon atoms.
• R 17a is more preferably an alkyl group having 1 to 6 carbon atoms
• R 17a is more preferably an alkyl group having 1 to 4 carbon atoms.
• the polyalkylene glycol (PAG) is preferably a compound (B1) represented by the following general formula (B-1):
• B-1 The polyalkylene glycol (PAG)
• the base oil may contain the PAG alone or in combination of two or more kinds.
• R 1b represents a hydrogen atom, a monovalent hydrocarbon group having from 1 to 10 carbon atoms, an acyl group having from 2 to 10 carbon atoms, a divalent to hexavalent hydrocarbon group having from 1 to 10 carbon atoms, or a substituted or unsubstituted heterocyclic group having from 3 to 10 ring atoms.
• R 2b represents an alkylene group having 2 to 4 carbon atoms.
• R 3b represents a hydrogen atom, a monovalent hydrocarbon group having from 1 to 10 carbon atoms, an acyl group having from 2 to 10 carbon atoms, or a substituted or unsubstituted heterocyclic group having from 3 to 10 ring atoms.
• n is an integer of 1 or more and 6 or less, preferably an integer of 1 or more and 4 or less, more preferably an integer of 1 or more and 3 or less, and further preferably 1.
• n is determined according to the number of bonding sites of R 1b in general formula (B-1). For example, when R 1b is an alkyl group or an acyl group, n is 1, and when R 1b is a hydrocarbon group or a heterocyclic group and the valence of the group is 2, 3, 4, 5, or 6, n is 2, 3, 4, 5, or 6, respectively.
• m is the average value of the number of units represented by OR 2b and is a number of 1 or more, and is preferably a number such that the average value of m ⁇ n is 6 or more and 80 or less.
• the value of m is not particularly limited, and is preferably a number such that the average value of m ⁇ n satisfies the above-mentioned range.
• each of the plurality of OR 2b may be the same or different.
• n is 2 or more, each of the plurality of R 3b in one molecule may be the same or different.
• Examples of the monovalent hydrocarbon group that can be selected as R 1b and R 3b include alkyl groups such as methyl group, ethyl group, various propyl groups, various butyl groups, various pentyl groups, various hexyl groups, various heptyl groups, various octyl groups, various nonyl groups, and various decyl groups; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, various methylcyclohexyl groups, various ethylcyclohexyl groups, various propylcyclohexyl groups, and various dimethylcyclohexyl groups; aryl groups such as phenyl group, various methylphenyl groups, various ethylphenyl groups, various dimethylphenyl groups, various propylphenyl groups, various trimethylphenyl groups, various butylphenyl groups, and various naphthyl groups; and arylalkyl groups such
• the hydrocarbon group moiety of the acyl group having 2 to 10 carbon atoms that can be selected as R 1b and R 3b may be linear, branched, or cyclic.
• Examples of the alkyl group moiety include hydrocarbon groups having 1 to 9 carbon atoms among the hydrocarbon groups that can be selected as R 1b and R 3b .
• the number of carbon atoms in the acyl group is preferably 2 or more and 10 or less, more preferably 2 or more and 8 or less, and further preferably 2 or more and 6 or less.
• Examples of the divalent to hexavalent hydrocarbon group that can be selected as R 1b include residues in which one or more and five or less hydrogen atoms have been removed from the monovalent hydrocarbon groups that can be selected as R 1b described above, and residues in which a hydroxyl group has been removed from a polyhydric alcohol such as trimethylolpropane, glycerin, pentaerythritol, sorbitol, 1,2,3-trihydroxycyclohexane, or 1,3,5-trihydroxycyclohexane.
• the carbon number of the divalent or more and hexavalent or less hydrocarbon group is preferably 2 or more and 10 or less, more preferably 2 or more and 8 or less, and further preferably 2 or more and 6 or less.
• the heterocyclic group that can be selected as R 1b and R 3b is preferably an oxygen atom-containing heterocyclic group or a sulfur atom-containing heterocyclic group.
• the heterocyclic group may be a saturated ring or an unsaturated ring.
• Examples of the oxygen-atom-containing heterocyclic group include residues in which one to six hydrogen atoms have been removed from an oxygen-atom-containing saturated heterocycle such as ethylene oxide, 1,3-propylene oxide, tetrahydrofuran, tetrahydropyran, and hexamethylene oxide; or an oxygen-atom-containing unsaturated heterocycle such as acetylene oxide, furan, pyran, oxycycloheptatriene, isobenzofuran, and isochromene.
• sulfur atom-containing heterocyclic group examples include residues in which one to six hydrogen atoms have been removed from sulfur atom-containing saturated heterocycles such as ethylene sulfide, trimethylene sulfide, tetrahydrothiophene, tetrahydrothiopyran, and hexamethylene sulfide; or sulfur atom-containing unsaturated heterocycles such as acetylene sulfide, thiophene, thiapyran, and thiotripyridene.
• sulfur atom-containing saturated heterocycles such as ethylene sulfide, trimethylene sulfide, tetrahydrothiophene, tetrahydrothiopyran, and hexamethylene sulfide
• sulfur atom-containing unsaturated heterocycles such as acetylene sulfide, thiophene, thiapyran, and thiotripyridene.
• the heterocyclic group which may be selected as R 1b and R 3b may have a substituent, and the substituent may be bonded to an oxygen atom in general formula (B-1).
• the substituent is as described above, and is preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and even more preferably an alkyl group having 1 to 3 carbon atoms.
• the number of ring atoms in the heterocyclic group is preferably 3 or more and 10 or less, more preferably 3 or more and 8 or less, and even more preferably 3 or more and 6 or less, from the viewpoint of thermal stability with the mixed refrigerant.
• alkylene group examples include alkylene groups having two carbon atoms, such as dimethylene group (-CH 2 CH 2 -) and ethylene group (-CH(CH 3 )-); alkylene groups having three carbon atoms, such as trimethylene group (-CH 2 CH 2 CH 2 -), propylene group (-CH(CH 3 )CH 2 -), propylidene group (-CHCH 2 CH 3 -) and isopropylidene group (-C(CH 3 ) 2 -); tetramethylene group (-CH 2 CH 2 CH 2 CH 2 -), 1-methyltrimethylene group (-CH(CH 3 )CH 2 CH 2 -), 2-methyltrimethylene group (-CH 2 CH(CH 3 )CH 2 -), butylene group (-C(CH 3 ) 2 CH 2 - ), and the like.
• alkylene groups having two carbon atoms such as dimethylene group (-CH 2 CH 2 -) and ethylene group (-CH(CH 3 )-)
• R 2b alkylene groups having 4 carbon atoms such as 4-(1-(-)).
• the plurality of R 2b's may be the same or may be a combination of two or more types of alkylene groups.
• R 2b is preferably a propylene group (--CH(CH 3 )CH 2 -).
• the content of oxypropylene units (-OCH( CH3 ) CH2- ) in compound (B1) represented by general formula (B- 1 ) is preferably 50 mol% or more and 100 mol% or less, more preferably 65 mol% or more and 100 mol% or less, and even more preferably 80 mol% or more and 100 mol% or less, based on the total amount (100 mol%) of oxyalkylene units (OR2b) in compound (B1).
• At least one selected from the group consisting of polyoxypropylene glycol dimethyl ether represented by the following general formula (B-1-i), polyoxyethylene polyoxypropylene glycol dimethyl ether represented by the following general formula (B-1-ii), polyoxypropylene glycol monobutyl ether represented by the following general formula (B-1-iii), and polyoxypropylene glycol diacetate are preferred.
• m1 is the average number of oxypropylene units, and is a number of 1 or more, preferably 6 or more and 80 or less.
• m2 and m3 are the average values of the number of oxypropylene units and oxyethylene units, respectively, and each independently represents a number of 1 or more, preferably a number such that the value of m2+m3 is 6 or more and 80 or less.
• m4 is the average number of oxypropylene units, and is a number of 1 or more, preferably 6 or more and 80 or less.
• m1 in general formula (B-1-i), m2 and m3 in general formula (B-1-ii), and m4 in general formula (B-1-iii) are values that are appropriately set so that the hydroxyl value of the base oil (P) falls within a range of 15 mg KOH/g or less, and are not particularly limited as long as the hydroxyl value is adjusted to fall within a predetermined range, and each is preferably a number that satisfies the aforementioned range.
• the number average molecular weight (Mn) of the above-mentioned PVE and PAG, and the below-mentioned POE is preferably independently 300 or more and 3,000 or less.
• Mn number average molecular weight
• the lubricity and sealing property are good
• the compatibility with mixed refrigerants is good.
• the number average molecular weight (Mn) of the PVE and PAG, and the POE described later are each independently more preferably 350 or more, even more preferably 400 or more, and more preferably 2,800 or less, even more preferably 2,500 or less, still more preferably 2,000 or less, and even more preferably 1,500 or less.
• the number average molecular weight (Mn) is a value measured by the method described in the Examples section below.
• the base oil may further contain other base oils in addition to one or more base oils selected from the group consisting of PVE and PAG, within the range not impairing the effects of the present invention.
• the other base oils include mineral oils or other synthetic oils not corresponding to the above-mentioned PVEs and PAGs, such as polyol esters (POEs), polyesters, polycarbonates, hydrogenated ⁇ -olefin oligomers, alicyclic hydrocarbon compounds, and alkylated aromatic hydrocarbon compounds; or mineral oils.
• the polyol esters include, for example, esters of diols or polyols and fatty acids.
• the base oil may contain the POE alone or in combination of two or more kinds.
• esters of diols or polyols having 3 to 20 hydroxyl groups and fatty acids having 3 to 20 carbon atoms are preferred.
• diol examples 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.
• polyol examples include polyhydric alcohols such as trimethylolethane, trimethylolpropane, trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol, di-(pentaerythritol), tri-(pentaerythritol), glycerin, polyglycerin (a dimer to 20-mer of glycerin), 1,3,5-pentanetriol, sorbitol, sorbitan, sorbitol glycerin condensates, adonitol, arabitol, xylitol, and mannitol; sugars such as xylose, arabinose, ribose, rhamnose, glucose, fructose, galactose, mannose, sorbose, cellobiose, maltose, isomaltose, trehalose, sucrose,
• hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di-(trimethylolpropane), tri-(trimethylolpropane), pentaerythritol, di-(pentaerythritol), and tri-(pentaerythritol) are preferred.
• the number of carbon atoms in the fatty acid is preferably 3 or more, more preferably 4 or more, and is preferably 20 or less, more preferably 16 or less, and further preferably 9 or less.
• the carbon number of the fatty acid includes the carbon atom of the carboxy group (-COOH) contained in the fatty acid.
• the fatty acid may be either a linear fatty acid or a branched fatty acid, but from the viewpoint of lubrication performance, the linear fatty acid is preferred, and from the viewpoint of hydrolysis stability, the branched fatty acid is preferred.
• the fatty acid may further be either a saturated fatty acid or an unsaturated fatty acid.
• fatty acid examples include linear or branched fatty acids such as isobutyric acid, propionic acid, butanoic acid, pentanoic acid, hexanoic 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, icosanoic acid, and oleic acid, and so-called neo acids in which the ⁇ carbon atom is quaternary.
• linear or branched fatty acids such as isobutyric acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid,
• the fatty acid is preferably at least one selected from the group consisting of isobutyric acid, valeric acid (n-pentanoic acid), caproic acid (n-hexanoic acid), enanthic acid (n-heptanoic acid), caprylic acid (n-octanoic acid), pelargonic acid (n-nonanoic acid), capric acid (n-decanoic acid), oleic acid (cis-9-octadecenoic acid), isopentanoic acid (3-methylbutanoic acid), 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid.
• the POE may be a partial ester in which all of the hydroxyl groups of the polyol remain unesterified, a complete ester in which all of the hydroxyl groups are esterified, or a mixture of the partial ester and the complete ester, with a complete ester being preferred.
• esters of hindered alcohols such as neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, di(trimethylolpropane), tri(trimethylolpropane), pentaerythritol, di(pentaerythritol), and tri(pentaerythritol) are preferred from the viewpoint of superior hydrolytic stability, and neopentyl glycol, trimethylolethane, trimethylolpropane, trimethylolbutane, esters of pentaerythritol, and esters of di(pentaerythritol) are more preferred, and furthermore, esters of pentaerythritol and esters of di(pentaerythritol) are even more preferred from the viewpoint of superior compatibility with the mixed refrigerant and superior hydrolytic stability.
• hindered alcohols such as neopentyl glycol, trimethylo
• a preferred embodiment of POE is, for example, a diester of neopentyl glycol with one or more fatty acids selected from the group consisting of isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,5-trimethylhexanoic acid; a triester of trimethylolethane with one or more fatty acids selected from the group consisting of isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, oleic acid, isopentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-ethylhexanoic acid, and 3,5,
• an ester of a polyol and two or more mixed fatty acids is preferred, and an ester of a polyol having 2 to 20 hydroxyl groups and two or more mixed fatty acids having 3 to 20 carbon atoms is more preferred.
• Examples of the mixed fatty acids of two or more kinds include mixed fatty acids combining two or more kinds of fatty acids preferably selected from the group consisting of fatty acids having from 4 to 9 carbon atoms, more preferably mixed fatty acids combining fatty acids having 8 and 9 carbon atoms, mixed fatty acids combining fatty acids having 5 and 9 carbon atoms, and one or more mixed fatty acids selected from the group consisting of mixed fatty acids combining fatty acids having 4, 5 and 9 carbon atoms, and even more preferably mixed fatty acids combining fatty acids having 8 and 9 carbon atoms.
• the ester may be a mixture of two or more esters of one fatty acid and a polyol.
• mineral oil examples include oils obtained by subjecting lubricating oil fractions obtained by vacuum distillation of atmospheric residual oil obtained by atmospheric distillation of crude oils such as paraffinic crude oil, intermediate base crude oil, or naphthenic crude oil, to one or more of the following processes: solvent deasphalting; solvent extraction or hydrocracking; solvent dewaxing or catalytic dewaxing; hydrorefining; and the like; oils produced by isomerizing mineral oil wax; and oils produced by hydroisomerization dewaxing of residual wax (gas-to-liquid wax) in a GTL process having a Fischer-Tropsch process or the like.
• the synthetic oils and mineral oils that can be used as the other base oils described above may be used alone or in combination of two or more kinds.
• the content of the other base oils is preferably more than 0% by mass and not more than 10% by mass, more preferably more than 0% by mass and not more than 5% by mass, and even more preferably more than 0% by mass and not more than 2% by mass, based on 100% by mass of the total amount of the base oil.
• the content of the base oil in the refrigeration oil is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and even more preferably 97% by mass or more and 100% by mass or less, based on the total amount of the refrigeration oil (100% by mass).
• the kinematic viscosity of the base oil at 100° C. (hereinafter also referred to as “100° C. kinematic viscosity”) is preferably 2.0 mm 2 /s or more and 50.0 mm 2 /s or less.
• the kinetic viscosity is 2.0 mm 2 /s or more, the lubricating property and sealing property are good, whereas when the kinetic viscosity is 50.0 mm 2 /s or less, the energy saving property of the obtained composition for a refrigerator is good.
• the 100°C kinematic viscosity of the base oil is preferably 3.0 mm2 /s or more, more preferably 4.0 mm2 /s or more, even more preferably 5.0 mm2 /s or more, and preferably 40.0 mm2 /s or less, more preferably 30.0 mm2 /s or less, even more preferably 25.0 mm2 /s or less, and even more preferably 15.0 mm2 /s or less.
• the 40°C kinematic viscosity of the base oil (hereinafter also referred to as "40°C kinematic viscosity”) is preferably 10.0 mm2 /s or more, more preferably 20.0 mm2 /s or more, even more preferably 25.0 mm2 /s or more, and preferably 250.0 mm2 /s or less, more preferably 200.0 mm2 /s or less, even more preferably 150.0 mm2 /s or less, and even more preferably 120.0 mm2 /s or less.
• the 100° C. kinematic viscosity and 40° C. kinematic viscosity of the base oil are values measured by the method described in the examples below.
• the hydroxyl value of the base oil is preferably 30 mgKOH/g or less, more preferably 25 mgKOH/g or less, even more preferably 20 mgKOH/g or less, still more preferably 15 mgKOH/g or less, even more preferably 10 mgKOH/g or less, and even more preferably 5 mgKOH/g or less.
• the hydroxyl value of the base oil (A) is usually 0.1 mgKOH/g or more.
• the hydroxyl value of the base oil is a value measured by neutralization titration method in accordance with JIS K0070:1992.
• the flash point of the base oil is preferably 170° C. or higher. From this viewpoint, the flash point of the base oil is more preferably 180° C. or higher, even more preferably 190° C. or higher, and still more preferably 195° C. or higher. There is no particular upper limit to the flash point of the base oil, but it is, for example, 300° C. or lower.
• the flash point of the base oil is a value measured by the method described in the examples below.
• the refrigerating machine oil may contain, in addition to the base oil, various additives that the refrigerating machine oil may contain (hereinafter, also referred to as "other additives").
• other additives include one or more additives selected from the group consisting of an antioxidant, an oiliness improver, an extreme pressure agent, an acid scavenger, an oxygen scavenger, a metal deactivator, a rust inhibitor, and an antifoaming agent.
• the total content of the other additives is, based on the total amount (100 mass%) of the refrigerating machine oil, preferably 0.1 mass% or more, more preferably 0.2 mass% or more, even more preferably 0.3 mass% or more, and is preferably 10 mass% or less, more preferably 5 mass% or less, even more preferably 3 mass% or less, and still more preferably 2 mass% or less.
• the refrigerating machine oil does not necessarily need to contain the other additives.
• antioxidants examples include phenol-based antioxidants and amine-based antioxidants.
• examples of the phenol-based antioxidant include monophenol-based antioxidants and polyphenol-based antioxidants.
• examples of the monophenol-based antioxidant include alkyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionates such as n-octyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 6-methylheptyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and n-octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.
• alkyl group examples include those having 4 to 20 carbon atoms, preferably those having 8 to 18 carbon atoms; 2,6-di-tert-butyl-4-alkylphenols (alkyl group having 1 to 4 carbon atoms) such as 2,6-di-tert-butyl-4-methylphenol and 2,6-di-tert-butyl-4-ethylphenol; 2,4-dimethyl-6-tert-butylphenol, 2,6-di-tert-amyl-p-cresol, and the like.
• the polyphenol-based antioxidants include 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-bis(2,6-di-tert-butylphenol), 4,4'-bis(2-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 4,4'-isopropylidenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-nonylphenol), 2,2 '-isobutylidenebis(4,6-dimethylphenol), 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 4,4'-thiobis(2-methyl-6-tert-butylphenol), 4,4'-thiobis(
• the amine-based antioxidants include dialkyldiphenylamines such as 4,4'-dibutyldiphenylamine and 4,4'-dioctyldiphenylamine; phenyl- ⁇ -naphthylamines such as alkylphenyl- ⁇ -naphthylamine and phenyl- ⁇ -naphthylamine; and N,N'-diphenyl-p-phenylenediamine.
• dialkyldiphenylamines such as 4,4'-dibutyldiphenylamine and 4,4'-dioctyldiphenylamine
• phenyl- ⁇ -naphthylamines such as alkylphenyl- ⁇ -naphthylamine and phenyl- ⁇ -naphthylamine
• N,N'-diphenyl-p-phenylenediamine N,N'-diphenyl-p-pheny
• the refrigerating machine oil may contain one type of antioxidant alone or two or more types of antioxidants in combination.
• the content of the antioxidant is preferably 0.1 mass% or more, more preferably 0.2 mass% or more, and even more preferably 0.3 mass% or more based on the total amount (100 mass%) of the refrigerating machine oil, from the viewpoint of suppressing an increase in the acid value of the obtained refrigerating machine oil and making it easier to improve the oxidation stability at high temperatures.
• the content is preferably 5 mass% or less, more preferably 3 mass% or less, and even more preferably 1 mass% or less.
• oiliness improver examples include aliphatic saturated or 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 or unsaturated monoamines such as stearylamine and oleylamine; aliphatic saturated or unsaturated monocarboxylic acid amides such as lauric acid amide and oleic acid amide; partial esters of polyhydric alcohols such as glycerin and sorbitol with aliphatic saturated or unsaturated monocarboxylic acids; and the like.
• aliphatic saturated or unsaturated monocarboxylic acids such as stearic acid and oleic acid
• polymerized fatty acids such as dimer acid and hydrogenated dimer
• the refrigerating machine oil may contain one type of oiliness improver alone or two or more types of oiliness improvers in combination.
• the content of the oiliness improver is, based on the total amount (100 mass%) of the refrigerating machine oil, preferably 0.01 mass% or more, more preferably 0.05 mass% or more, even more preferably 0.1 mass% or more, and is preferably 10 mass% or less, more preferably 5 mass% or less, even more preferably 2 mass% or less.
• the extreme pressure agent examples include phosphorus-based extreme pressure agents, such as phosphate esters, phosphites, acid phosphate esters, acid phosphites, and amine salts thereof.
• phosphoric acid ester examples include triaryl phosphate, trialkyl phosphate, monoalkyl diaryl phosphate, dialkyl monoaryl phosphate, trialkenyl phosphate, etc.
• aryl used in the description of the extreme pressure agent is not limited to a functional group consisting of only an aromatic ring, but is a concept including alkylaryl and arylalkyl.
• phosphate esters examples include triaryl phosphates such as triphenyl phosphate, tricresyl phosphate, benzyl diphenyl phosphate, cresyl diphenyl phosphate, dicresyl phenyl phosphate, propyl phenyl diphenyl phosphate, dipropyl phenyl phosphate, ethyl phenyl diphenyl phosphate, diethyl phenyl phosphate, triethyl phenyl phosphate, tripropyl phenyl phosphate, butyl phenyl diphenyl phosphate, dibutyl phenyl phosphate, and tributyl phenyl phosphate; alkyl phosphates such as tributyl phosphate, ethyl dibutyl phosphate, trihexyl phosphate, tri(2-ethylhexyl) phosphate, tridec
• the refrigerating machine oil may contain one type of extreme pressure agent alone or two or more types of extreme pressure agents in combination.
• the content of the extreme pressure agent is, based on the total amount (100 mass%) of the refrigerating machine oil, preferably 0.1 mass% or more, more preferably 0.3 mass% or more, even more preferably 0.5 mass% or more, and is preferably 5 mass% or less, more preferably 3 mass% or less, even more preferably 2 mass% or less.
• the acid scavenger may be, for example, an epoxy compound.
• the epoxy compound include a glycidyl ether compound, cyclohexene oxide, ⁇ -olefin oxide, and epoxidized soybean oil. Among these, the glycidyl ether compound is preferred.
• Examples of the glycidyl ether compound include an aliphatic monoalcohol having preferably 3 to 30 carbon atoms, more preferably 4 to 24 carbon atoms, and even more preferably 6 to 16 carbon atoms; an aliphatic polyhydric alcohol having 3 to 30 carbon atoms, more preferably 4 to 24 carbon atoms, and even more preferably 6 to 16 carbon atoms; or a glycidyl ether derived from an aromatic compound containing one or more hydroxyl groups.
• the aliphatic monoalcohol or aliphatic polyhydric alcohol may be linear, branched, or cyclic, and may be saturated or unsaturated.
• the glycidyl ether compounds include phenyl glycidyl ether, alkyl glycidyl ether, alkylene glycol glycidyl ether, etc.
• Examples of the glycidyl ether compounds include linear, branched, or cyclic glycidyl ethers derived from saturated aliphatic monoalcohols having 6 to 16 carbon atoms (i.e., alkyl glycidyl ethers having an alkyl group with 6 to 16 carbon atoms), such as 2-ethylhexyl glycidyl ether, isononyl glycidyl ether, decyl glycidyl ether, lauryl glycidyl ether, and myristyl glycidyl ether.
• the refrigerating machine oil may contain one type of acid scavenger alone or two or more types in combination.
• the content of the acid scavenger is preferably 0.1 mass% or more, more preferably 0.4 mass% or more, and even more preferably 0.8 mass% or more based on the total amount (100 mass%) of the refrigerating machine oil from the viewpoint of further improving the oxidation stability at high temperatures, and the content is preferably 10 mass% or less, more preferably 5 mass% or less, even more preferably 3 mass% or less, and even more preferably 2 mass% or less from the viewpoint of easily exerting an effect commensurate with the content.
• oxygen scavengers include sulfur-containing aromatic compounds such as 4,4'-thiobis(3-methyl-6-tert-butylphenol), diphenyl sulfide, dioctyldiphenyl sulfide, dialkyldiphenylene sulfide, benzothiophene, dibenzothiophene, phenothiazine, benzothiapyran, thiapyran, thianthrene, dibenzothiapyran, and diphenylene disulfide; aliphatic unsaturated compounds such as various olefins, dienes, and trienes; and terpenes with double bonds.
• sulfur-containing aromatic compounds such as 4,4'-thiobis(3-methyl-6-tert-butylphenol), diphenyl sulfide, dioctyldiphenyl sulfide, dialkyldiphenylene sulfide, benzothiophene, dibenzothiophen
• the refrigerating machine oil may contain one type of oxygen scavenger alone or two or more types in combination.
• the content of the oxygen scavenger is, based on the total amount (100 mass%) of the refrigerating machine oil, preferably 0.01 mass% or more, more preferably 0.05 mass% or more, even more preferably 0.1 mass% or more, and preferably 10 mass% or less, more preferably 5 mass% or less, even more preferably 3 mass% or less, and still more preferably 2 mass% or less.
• the metal deactivator examples include copper deactivators such as N-[N,N'-dialkyl (alkyl group having 3 to 12 carbon atoms)aminomethyl]triazole.
• the rust inhibitor examples include metal sulfonates, aliphatic amines, organic phosphites, organic phosphates, organic sulfonic acid metal salts, organic phosphate metal salts, alkenyl succinates, and polyhydric alcohol esters.
• the antifoaming agent examples include silicone oils such as dimethylpolysiloxane, polymethacrylates, and the like.
• the refrigerating machine oil may contain one kind of the metal deactivator, the rust inhibitor, or the antifoaming agent, or may contain two or more kinds of them in combination.
• the content of each of them is, based on the total amount (100 mass%) of the refrigerating machine oil, preferably 0.01 mass% or more, more preferably 0.05 mass% or more, even more preferably 0.1 mass% or more, and preferably 10 mass% or less, more preferably 5 mass% or less, even more preferably 3 mass% or less, and still more preferably 2 mass% or less.
• the content ratio of the refrigerating machine oil to the mixed refrigerant is, in mass ratio, preferably 1/99 to 99/1, more preferably 1/99 to 90/10, even more preferably 5/95 to 88/12, and still more preferably 10/95 to 60/40.
• mass ratio of the refrigerating machine oil to the mixed refrigerant is within the range, lubricity and suitable refrigeration capacity in a refrigerator can be obtained.
• the total content of the mixed refrigerant and the refrigerating machine oil in the refrigerating machine composition is, based on the total amount (100 mass%) of the refrigerating machine composition, preferably 90 mass% or more and 100 mass% or less, more preferably 95 mass% or more and 100 mass% or less, even more preferably 98 mass% or more and 100 mass% or less, and still more preferably 100 mass%.
• refrigerator oil The refrigerating machine oil according to this embodiment is used together with the mixed refrigerant in the above-mentioned refrigerating machine composition, and the details thereof are the same as those described above.
• a method for producing a refrigerating machine composition is a method for producing a refrigerating machine composition, comprising a step of mixing a mixed refrigerant with a refrigerating machine oil containing a base oil, wherein the mixed refrigerant contains a fluorohydrocarbon compound and carbon dioxide, the content of the fluorohydrocarbon compound is less than 25 mass% based on the total amount of the mixed refrigerant, and the base oil contains one or more selected from the group consisting of polyvinyl ethers (PVE) and polyalkylene glycols (PAG).
• PVE polyvinyl ethers
• PAG polyalkylene glycols
• the detailed description of the mixed refrigerant and the refrigerating machine oil is the same as that described above, and therefore the description is omitted.
• the preferred range of the total content of the mixed refrigerant and the refrigerating machine oil in the refrigerating machine composition is also the same as that described above.
• the composition for refrigerator is used by being filled inside a refrigerator.
• the refrigerator is preferably a compression type refrigerator that uses the mixed refrigerant, and more preferably has a refrigeration cycle including a compressor, a condenser, an expansion mechanism (such as an expansion valve) and an evaporator, or a refrigeration cycle including a compressor, a condenser, an expansion mechanism, a dryer and an evaporator.
• the composition for refrigerators is used, for example, to lubricate sliding parts provided in compressors etc. The sliding parts are not particularly limited.
• Examples of equipment equipped with the above-mentioned refrigeration unit include car air conditioners such as open type car air conditioners and electric car air conditioners, air conditioners such as room air conditioners and packaged air conditioners, refrigeration systems such as gas heat pumps (GHPs), freezers, refrigerators, vending machines and showcases, hot water systems such as water heaters and floor heating, heating systems, and the like.
• the refrigeration unit is preferably applied to air conditioners, and more preferably to room air conditioners and packaged air conditioners.
• the usage ratio of the refrigerating oil to the mixed refrigerant (refrigerating oil/mixed refrigerant) in terms of mass ratio is preferably 1/99 or more and 99/1 or less, more preferably 1/99 or more and 90/10 or less, even more preferably 5/95 or more and 88/12 or less, and still more preferably 10/95 or more and 60/40 or less.
• the ratio of the amounts used is the ratio of the mixed refrigerant and the refrigerating machine oil used in the device, and is based on the amounts used when each is introduced into the system, regardless of whether the mixed refrigerant and the refrigerating machine oil are completely or partially compatible with each other. In other words, it does not refer to the ratio of the amounts of each component in the refrigerating machine composition.
• the GPC was performed using two "TSKgel SuperMultiporeHZ-M” columns connected in series, tetrahydrofuran as an eluent, and a refractive index detector (RI detector) as a detector, and the number average molecular weight (Mn) was determined using polystyrene as a standard sample.
• RI detector refractive index detector
• the oil appearance was evaluated by ASTM color, and oils judged to have a good appearance were those judged to be 1.0 or less (L1.0), and oils judged to have a poor appearance were those judged to be greater than 1.0 (L1.5, L2.0, etc.).
• the acid value of each refrigerating machine oil composition was evaluated by the method described below. (Evaluation of acid value of refrigerator oil composition) The measurement was performed by indicator photometric titration method (see Appendix 1 of the JIS standard) in accordance with JIS K2501:2003.
• Example 1 to 6 and Comparative Examples 1 to 9 Each refrigerating machine composition was prepared by mixing a refrigerating machine oil containing 100 mass% of the base oil shown in Table 1 and a mixed refrigerant having a composition shown in Table 2 below at the mixing ratio shown in Table 2 below, and the thermal stability was evaluated as described above. The obtained results are shown in Table 2 below.
• the refrigerator compositions of Examples 1 to 6 contain carbon dioxide and have low global warming potential, yet all have high thermal stability.
• the refrigerating machine compositions of Comparative Examples 1, 2, 8 and 9 had a fluorohydrocarbon compound content of 25 mass% or more, and had poor color after the thermal stability test and a larger acid value.
• the refrigerating machine compositions of Comparative Examples 3 to 7 in which polyol ethers were used as the base oil for the refrigerating machine oil the color after thermal stability test was poor, and discoloration of the iron catalyst and copper catalyst was confirmed.
• the refrigeration composition according to one embodiment of the present invention is a mixture of a refrigerant oil and a mixed refrigerant containing carbon dioxide, which is a refrigerant with a low global warming potential, and has excellent thermal stability, making it suitable for use in refrigeration machines, and can be used, for example, as a refrigeration composition for use in a closed compression type refrigeration device using a mixed refrigerant.
• the mixed refrigerant since it is a refrigeration composition containing the mixed refrigerant, it can also be used, for example, in car air conditioners such as open-type car air conditioners and electric car air conditioners, air conditioners such as room air conditioners and packaged air conditioners, refrigeration systems such as gas heat pumps (GHPs), freezers, refrigerators, vending machines, and showcases, hot water systems such as water heaters and floor heating, and heating systems.
• car air conditioners such as open-type car air conditioners and electric car air conditioners
• air conditioners such as room air conditioners and packaged air conditioners
• refrigeration systems such as gas heat pumps (GHPs), freezers, refrigerators, vending machines, and showcases
• hot water systems such as water heaters and floor heating, and heating systems.

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