Refrigerating machine oil, and working fluid composition for refrigerating machines
The present invention provides a refrigerating machine oil comprising a base oil; a sulfide compound; and an orthophosphoric acid ester, wherein a content of the sulfide compound is 0.01 to 2.0% by mass and a content of the orthophosphoric acid ester is 0.1 to 5.0% by mass, based on a total amount of the refrigerating machine oil, and the refrigerating machine oil having a kinematic viscosity at 40° C. of 3 to 500 mm 2 /s.
1. A refrigerating machine oil comprising:
a base oil comprising a polyol ester obtainable by synthesis from a polyhydric alcohol with 4 or more and 12 or less carbon atoms and a fatty acid consisting of at least one selected from butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, isobutanoic acid, 2-methylbutanoic acid, 2-methylpentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-methylheptanoic acid and 3,5,5-trimethylhexanoic acid;
a sulfide compound;
an orthophosphoric acid ester; and
2 to 20% by mass of pentaerythritol tetra(2-ethylhexanoate) based on the total amount of the refrigerating machine oil,
wherein
a content of the sulfide compound is 0.01 to 2.0% by mass and
a content of the orthophosphoric acid ester is 0.1 to 5.0% by mass, based on a total amount of the refrigerating machine oil, and
the refrigerating machine oil having a kinematic viscosity at 40° C. of 5 to 150 mm 2 /s.
2. The refrigerating machine oil according to claim 1 , wherein
the sulfide compound is a thiobisphenol compound and
the orthophosphoric acid ester is at least one selected from the group consisting of
triphenyl phosphate,
tricresyl phosphate, and
an alkylphenyl phosphate having a C3-C4 alkyl group.
3. A working fluid composition for a refrigerating machine comprising:
a refrigerant comprising difluoromethane and having a global warming potential of 700 or less; and
the refrigerating machine oil according to claim 1 .
4. The refrigerating machine oil according to claim 1 , wherein the polyol ester is not an ester obtainable by synthesis from pentaerythritol and a mixed acid of 2-ethylhexanoic acid and 3,5,5-trimethylhexanoic acid in a mass ratio of 5:5.
5. The working fluid composition for a refrigerating machine comprising:
a refrigerant comprising difluoromethane; and
a refrigerating machine oil comprising:
a base oil comprising a polyol ester obtainable by synthesis from a polyhydric alcohol with 4 or more and 12 or less carbon atoms and a fatty acid consisting of at least one selected from butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, isobutanoic acid, 2-methylbutanoic acid, 2-methylpentanoic acid, 2-methylhexanoic acid, 2-ethylpentanoic acid, 2-methylheptanoic acid and 3,5,5-trimethylhexanoic acid;
a sulfide compound;
an orthophosphoric acid ester; and
2 to 20% by mass of pentaerythritol tetra(2-ethylhexanoate) based on the total amount of the refrigerating machine oil;
wherein
a content of the sulfide compound is 0.01 to 2.0% by mass, and
a content of the orthophosphoric acid ester is 0.1 to 5.0% by mass, based on a total amount of the refrigerating machine oil,
and wherein the refrigerating machine oil has a kinematic viscosity at 40° C. of 5 to 150 mm 2 /s.
6. The working fluid composition according to claim 5 , wherein
the sulfide compound is a thiobisphenol compound and
the orthophosphoric acid ester is at least one selected from the group consisting of
triphenyl phosphate,
tricresyl phosphate, and
an alkylphenyl phosphate having a C3-C4 alkyl group.
7. The working fluid composition according to claim 5 , the refrigerant with a global warming potential of 700 or less.
8. The working fluid composition according to claim 5 , wherein the polyol ester is not an ester obtainable by synthesis from pentaerythritol and a mixed acid of 2-ethylhexanoic acid and 3,5,5-trimethylhexanoic acid in a mass ratio of 5:5.