Refrigerator oil, and working fluid composition for refrigerators
The present invention provides a refrigerating machine oil comprising a polyvinylether having a structural unit represented by the following formula (1): wherein R 1 , R 2 , and R 3 may be the same or different from each other and each represent a hydrogen atom or a hydrocarbon group, R 4 represents a divalent hydrocarbon group or an ethereal oxygen-containing divalent hydrocarbon group, R 5 represents a hydrocarbon group, m represents an integer of 0 or more, and in the case where m is 2 or more, a plurality of R 4 may be the same or different from each other, a number average molecular weight Mn is 500 or more and 2000 or less, a ratio of a weight average molecular weight Mw to a number average molecular weight Mn, Mw/Mn, is 1.10 or more and 1.25 or less, and the refrigerating machine oil is used with a mildly flammable hydrofluorocarbon refrigerant.
1. A refrigerating machine oil comprising a polyvinylether having a structural unit represented by the following formula (1):
wherein R 1 , R 2 , and R 3 are the same or different from each other and each represent a hydrogen atom or a hydrocarbon group, R 4 represents a divalent hydrocarbon group or an ethereal oxygen-containing divalent hydrocarbon group, R 5 represents a hydrocarbon group, m represents an integer of 0 or more, and in the case where m is 2 or more, a plurality of R 4 are the same or different from each other,
a number average molecular weight Mn of the polyvinylether is 500 or more and 2000 or less,
a ratio of a weight average molecular weight Mw to a number average molecular weight Mn, Mw/Mn, of the polyvinylether is 1.10 or more and 1.25 or less,
a flash point of the polyvinylether is 195° C. or more,
an autoignition point of the polyvinylether is 335° C. or more, and
the refrigerating machine oil is utilized with a mildly flammable hydrofluorocarbon refrigerant.
2. A working fluid composition for a refrigerating machine, comprising:
the refrigerating machine oil according to claim 1 ; and
a mildly flammable hydrofluorocarbon refrigerant.
3. The working fluid composition for a refrigerating machine according to claim 2 , wherein the mildly flammable hydrofluorocarbon refrigerant comprises at least one selected from difluoromethane, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetrafluoropropene.
4. A method of flame-retarding a refrigerating machine in which a mildly flammable hydrofluorocarbon refrigerant is utilized, the method comprising utilizing, as a refrigerating machine oil, a composition comprising a polyvinylether having a structural unit represented by a following formula (1):
wherein R 1 , R 2 , and R 3 are the same or different from each other and each represent a hydrogen atom or a hydrocarbon group, R 4 represents a divalent hydrocarbon group or an ethereal oxygen-containing divalent hydrocarbon group, R 5 represents a hydrocarbon group, m represents an integer of 0 or more, and in the case where m is 2 or more, a plurality of R 4 are the same or different from each other,
a number average molecular weight Mn of the polyvinylether is 500 or more and 2000 or less, and
a ratio of a weight average molecular weight Mw to the number average molecular weight Mn, Mw/Mn, of the polyvinylether is 1.10 or more and 1.25 or less,
a flash point of the polyvinylether is 195° C. or more, and
and autoignition point of the polyvinylether is 335° C. or more.
5. The refrigerating machine oil according to claim 1 , wherein the Mw/Mn of the polyvinylether is 1.17 or more and 1.25 or less.
6. The refrigerating machine oil according to claim 1 , wherein the Mw/Mn of the polyvinylether is more than 1.20 and 1.25 or less.
7. A working fluid composition for a refrigerating machine, comprising:
the refrigerating machine oil according to claim 5 ; and
a mildly flammable hydrofluorocarbon refrigerant comprising at least one selected from difluoromethane, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetrafluoropropene.
8. A working fluid composition for a refrigerating machine, comprising:
the refrigerating machine oil according to claim 6 ; and
a mildly flammable hydrofluorocarbon refrigerant comprising at least one selected from difluoromethane, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetrafluoropropene.
9. The refrigerating machine oil according to claim 1 , wherein the number average molecular weight Mn of the polyvinylether is 900 or more and 2000 or less.
10. A working fluid composition for a refrigerating machine, comprising:
the refrigerating machine oil according to claim 9 ; and
a mildly flammable hydrofluorocarbon refrigerant comprising at least one selected from difluoromethane, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetrafluoropropene.
11. The refrigerating machine oil according to claim 1 , wherein a kinematic viscosity of the polyvinylether at 40° C. is 50 mm 2 /s or more and 80 mm 2 /s or less.
12. The refrigerating machine oil according to claim 9 , wherein a kinematic viscosity of the polyvinylether at 40° C. is 50 mm 2 /s or more and 80 mm 2 /s or less.
13. A working fluid composition for a refrigerating machine, comprising:
the refrigerating machine oil according to claim 11 ; and
a mildly flammable hydrofluorocarbon refrigerant comprising at least one selected from difluoromethane, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetrafluoropropene.
14. A working fluid composition for a refrigerating machine, comprising:
the refrigerating machine oil according to claim 12 ; and
a mildly flammable hydrofluorocarbon refrigerant comprising at least one selected from difluoromethane, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetrafluoropropene.
15. The method according to claim 4 , wherein the Mw/Mn of the polyvinylether is more than 1.20 and 1.25 or less.
16. The method according to claim 15 , wherein the mildly flammable hydrofluorocarbon refrigerant comprising at least one selected from difluoromethane, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetrafluoropropene.
17. The method according to claim 4 , wherein the number average molecular weight Mn of the polyvinylether is 900 or more and 2000 or less.
18. The method according to claim 17 , wherein the mildly flammable hydrofluorocarbon refrigerant comprising at least one selected from difluoromethane, 1,3,3,3-tetrafluoropropene, and 2,3,3,3-tetrafluoropropene.