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EP-4317377-B1 - REFRIGERATOR OIL COMPOSITION AND MIXED COMPOSITION FOR REFRIGERATOR

EP4317377B1EP 4317377 B1EP4317377 B1EP 4317377B1EP-4317377-B1

Inventors

  • MATSUMOTO, TOMOYA

Dates

Publication Date
20260506
Application Date
20220310

Claims (13)

  1. A refrigerator oil composition used for a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the following general formula (1): C x F y H z (1) [wherein x is an integer of 2 to 6, y is an integer of 1 to 11, and z is an integer of 1 to 11, and one or more carbon-carbon unsaturated bonds are present in the molecule], the refrigerator oil composition comprising a base oil (A) selected from the group consisting of a polyalkylene glycol compound, a polyvinyl ether compound, a copolymer of poly(oxy)alkylene glycol or a monoether thereof and polyvinyl ether, and a polyol ester compound; an epoxy compound (B), wherein the epoxy compound (B) satisfies the following requirements (B1) and (B2): (B1) at least one divalent group represented by the following formula (1) is present in the molecule; (B2) at least one ester group is present in the molecule; and a glycidyl ether compound (C).
  2. The refrigerator oil composition according to claim 1, wherein the epoxy compound (B) has a molecular weight of 300 or more.
  3. The refrigerator oil composition according to claim 1 or 2, wherein the content of the epoxy compound (B) is 0.10% by mass or more based on the total amount of the refrigerator oil composition.
  4. The refrigerator oil composition according to any one of claims 1 to 3, wherein the epoxy compound (B) is one or more selected from the group consisting of an epoxidized fatty acid ester, an epoxidized alicyclic carboxylic acid ester, and an epoxidized vegetable oil.
  5. The refrigerator oil composition according to claim 4, wherein the epoxidized fatty acid ester is represented by the following general formula (1-1): wherein R 1 is a hydrocarbon group having 4 to 20 carbon atoms, R 2 is a hydrocarbon group having 1 to 10 carbon atoms, p is an integer of 1 to 3, n is an integer of 0 to 12, m is an integer of 1 to 3, and when m is 2 or more, a plurality of structures in brackets [] may be the same as or different from each other.
  6. The refrigerator oil composition according to claim 4, wherein the epoxidized alicyclic carboxylic acid ester is represented by the following general formula (1-2): wherein R 3 and R 4 are each independently a hydrocarbon group having 4 to 20 carbon atoms.
  7. The refrigerator oil composition according to claim 4, wherein the epoxidized vegetable oil is one or more selected from the group consisting of an epoxidized soybean oil, an epoxidized linseed oil, an epoxidized rice bran oil, and an epoxidized cottonseed oil.
  8. The refrigerator oil composition according to any one of claims 1-7, wherein the content ratio [(B)/(C)] of the epoxy compound (B) to the glycidyl ether compound (C) is 0.050 or more and 5.0 or less in terms of mass ratio.
  9. The refrigerator oil composition according to any one of claims 1 to 8, further comprising one or more additives selected from the group consisting of an antioxidant, a stabilizer, an extreme pressure agent, and an anti-foaming agent.
  10. A refrigerator oil mixture composition containing the refrigerator oil composition according to any one of claims 1 to 9, and a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds, wherein the unsaturated fluorinated hydrocarbon compound contains one or more selected from the group consisting of R1234ze, R1234yf, and R1234ye.
  11. The refrigerator oil mixture composition according to claim 10, wherein the refrigerant consists only of the unsaturated fluorinated hydrocarbon compound.
  12. A refrigerator oil mixture composition comprising: a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the following general formula (1): C x F y H z (1) [wherein x is an integer of 2 to 6, y is an integer of 1 to 11, and z is an integer of 1 to 11, and one or more carbon-carbon unsaturated bonds are present in the molecule]; and the refrigerator oil composition according to any one of claims 1 to 9.
  13. A method for producing a refrigerator oil composition used for a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the following general formula (1): C x F y H z (1) [wherein x is an integer of 2 to 6, y is an integer of 1 to 11, and z is an integer of 1 to 11, and one or more carbon-carbon unsaturated bonds are present in the molecule], the method comprising a step of mixing a base oil (A) selected from the group consisting of a polyalkylene glycol compound, a polyvinyl ether compound, a copolymer of poly(oxy)alkylene glycol or a monoether thereof and polyvinyl ether, and a polyol ester compound; an epoxy compound (B), wherein the epoxy compound (B) satisfies the following requirements (B1) and (B2): (B1) at least one divalent group represented by the following formula (1) is present in the molecule; (B2) at least one ester group is present in the molecule; and a glycidyl ether compound (C).

Description

Technical Field The present invention relates to a refrigerator oil composition, and a refrigerator oil mixture composition. In the description herein, the term "refrigerator oil mixture composition" refers to a composition obtained by mixing the "refrigerator oil composition" and the "refrigerant". Background Art Refrigerators, for example, compression-type refrigerators generally include at least compressors, condensers, expansion mechanisms (for example, expansion valves and the like), and evaporators, and have a structure in which a refrigerator oil mixture composition circulates in a closed system. As a refrigerant used in a refrigerator such as a compression-type refrigerator, a fluorinated hydrocarbon compound having a low environmental load is being used instead of a hydrochlorofluorocarbon (HCFC) which has been conventionally used in many cases. As the fluorinated hydrocarbon compounds, saturated fluorinated hydrocarbon compounds (Hydro-Fluoro-Carbon; hereinafter also referred to as "HFC") such as 1,1,1,2-tetrafluoroethane (R134a), difluoromethane (R32), and 1,1-difluoroethane (R152a) are being used. In addition, the use of unsaturated fluorinated hydrocarbon compounds (Hydro-Fluoro-Olefin; hereinafter also referred to as "HFO") such as 1,3,3,3-tetrafluoropropene (R1234ze), 2,3,3,3-tetrafluoropropene (R1234yf), and 1,2,3,3-tetrafluoropropene (R1234ye) having low global warming potential (GWP) has also been examined (see, for example, PTL 1). Refrigerator oil compositions, such as those comprising (i) a polyalkylene glycol or a poly ester and (ii) an epoxy compound, useful with an unsaturated fluorinated hydrocarbon compound, such as HFO-1234yf, have been shown to provide an excellent long-term stability (see for example PTL 2). Citation List Patent Literature PTL 1: JP 2006-503961 TPTL 2: EP 2 891 703 A1 Summary of Invention Technical Problem However, while unsaturated fluorinated hydrocarbon compounds (HFO) have an advantage of a low global warming potential (GWP), they have a disadvantage of inferior thermal stability at high temperatures compared to saturated fluorinated hydrocarbon compounds (HFC). Therefore, when the content of the unsaturated fluorinated hydrocarbon compound (HFO) in the refrigerant increases, there is a problem that the acid value of the refrigerator oil composition is likely to increase. In addition, in recent years, refrigerators have been made more compact and higher in performance, and their operating conditions have become severer than before. Therefore, the refrigerator oil composition is required to have higher quality than ever before. For example, while the amount of refrigerator oil composition used in the equipment is decreasing along with the compactification of the refrigerator, a portion which is locally high in temperature is likely to be generated due to frictional heat and the like in the sliding portion of the compressor due to the severe operating conditions. When the refrigerator oil mixture composition is exposed to such a portion, the acid value of the refrigerator oil composition is more likely to increase. Therefore, it is desired to create a refrigerator oil composition that can effectively suppress an increase in the acid value even when the content of the unsaturated fluorinated hydrocarbon compound (HFO) in the refrigerant is increased. The present invention has been made in view of such a demand, and an object of the present invention is to provide a refrigerator oil composition capable of effectively suppressing an increase in an acid value even when a content of an unsaturated fluorinated hydrocarbon compound (HFO) in a refrigerant is increased, and a refrigerator oil mixture composition containing the refrigerator oil composition. Solution to Problem The present inventor has conducted intensive studies to solve the above problem. As a result, the present inventor has found that a refrigerator oil composition containing a specific epoxy compound can solve the above problem, and has completed the present invention. That is, the present invention relates to the following [1] to [3]. [1] A refrigerator oil composition used for a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from compounds represented by the following general formula (1):         CxFyHz     (1) [wherein x is an integer of 2 to 6, y is an integer of 1 to 11, and z is an integer of 1 to 11, and one or more carbon-carbon unsaturated bonds are present in the molecule], the refrigerator oil composition containing a base oil (A) selected from the group consisting of a polyalkylene glycol compound, a polyvinyl ether compound, a copolymer of poly(oxy)alkylene glycol or a monoether thereof and polyvinyl ether, and a polyol ester compound; and an epoxy compound (B), wherein the epoxy compound (B) satisfies the following requirements (B1) and (B2): (B1) at least one divalent group represented by the following formula (1) is present in the molecule