Refrigerator oil and working fluid composition for refrigerators
The present invention provides a refrigerating machine oil comprising: a base oil containing an ester of dipentaerythritol with 2-methylbutanoic acid and n-pentanoic acid; and at least one epoxy compound selected from the group consisting of a glycidyl ester compound and a glycidyl ether compound, the refrigerating machine oil being used with a difluoromethane refrigerant.
1. A refrigerating machine oil comprising:
a base oil comprising an ester of dipentaerythritol with 2-methylbutanoic acid and n-pentanoic acid; and
an epoxy compound consisting of at least one epoxy compound selected from the group consisting of a glycidyl ester compound and a glycidyl ether compound,
wherein the glycidyl ester compound is represented by the following formula (1):
wherein R 1 represents an aryl group, an alkyl group, or an alkenyl group, and the number of carbon atoms of the aryl group, the alkyl group, and the alkenyl group is from 5 to 18, and
wherein the glycidyl ether compound is represented by the following formula (2):
wherein R 2 represents an aryl group or an alkyl group, and the number of carbon atoms of the aryl group and the alkyl group is from 5 to 18.
2. The refrigerating machine oil according to claim 1 , wherein a ratio of the ester in the base oil is 30% by mass or more and 100% by mass or less.
3. The refrigerating machine oil according to claim 1 , wherein a content of the epoxy compound is 0.01% by mass or more and 5.0% by mass or less based on a total amount of the refrigerating machine oil.
4. A working fluid composition for a refrigerating machine, comprising:
a refrigerating machine oil comprising:
a base oil comprising an ester of dipentaerythritol with 2-methylbutanoic acid and n-pentanoic acid; and
an epoxy compound consisting of at least one epoxy compound selected from the group consisting of a glycidyl ester compound and a glycidyl ether compound; and
a refrigerant comprising a difluoromethane refrigerant,
wherein the glycidyl ester compound is represented by the following formula (1):
wherein R 1 represents an aryl group, an alkyl group, or an alkenyl group, and the number of carbon atoms of the aryl group, the alkyl group and alkenyl group is from 5 to 18, and
wherein the glycidyl ether compound is represented by the following formula (2):
wherein R 2 represents an aryl group or an alkyl group, and the number of carbon atoms of the aryl group and the alkyl group is from 5 to 18.
5. The working fluid composition for a refrigerating machine according to claim 4 , wherein a ratio of the ester in the base oil is 30% by mass or more and 100% by mass or less.
6. The working fluid composition for a refrigerating machine according to claim 4 , wherein a content of the epoxy compound is 0.01% by mass or more and 5.0% by mass or less based on a total amount of the refrigerating machine oil.
7. The working fluid composition for a refrigerating machine according to claim 4 , wherein a content of the epoxy compound is 0.1% by mass or more and 5.0% by mass or less based on a total amount of the refrigerating machine oil.
8. The working fluid composition for a refrigerating machine according to claim 7 , wherein a ratio of the ester in the base oil is 30% by mass or more and 100% by mass or less.
9. The working fluid composition for a refrigerating machine according to claim 8 , wherein a content of difluoromethane is 20% by mass or more based on the total amount of the refrigerant.
10. The working fluid composition for a refrigerating machine according to claim 8 , wherein a ratio of the ester in the base oil is 50% by mass or more and 100% by mass or less.
11. The working fluid composition for a refrigerating machine according to claim 7 , wherein a molar ratio between 2-methylbutanoic acid and n-pentanoic acid (2-methylbutanoic acid:n-pentanoic acid) in fatty acids constituting the ester is from 8:2 to 2:8.
12. The working fluid composition for a refrigerating machine according to claim 7 , wherein a content of difluoromethane is 20% by mass or more based on the total amount of the refrigerant.
13. The working fluid composition for a refrigerating machine according to claim 4 , wherein a molar ratio between 2-methylbutanoic acid and n-pentanoic acid (2-methylbutanoic acid:n-pentanoic acid) in fatty acids constituting the ester is from 8:2 to 2:8.
14. The working fluid composition for a refrigerating machine according to claim 4 , wherein a content of difluoromethane is 20% by mass or more based on the total amount of the refrigerant.