Refrigerating machine oil composition and working fluid composition for refrigerating machine using same
Provided is a refrigerating machine oil composition for a refrigerant consisting of difluoromethane, the composition comprising a polymer (A) below and an ester (B) of polyhydric alcohol(s) with aliphatic monocarboxylic acid(s). The polymer (A): a polymer which is obtained by polymerizing monomer(s) consisting of at least one monomer of monosubstituted ethylenes and disubstituted ethylenes, and in which a ratio of a monomer represented by the following general formula (I): wherein R 1 represents an alkyl group having 1 to 5 carbon atoms, R 2 represents hydrogen or an alkyl group having 1 to 4 carbon atoms, and the sum of carbon numbers in R 1 and R 2 is 2 to 5, is 75 to 100% by mass based on a total mass of monomers constituting the polymer.
1. A refrigerating machine oil composition for a refrigerant consisting of difluoromethane, the composition comprising:
a polymer (A) below, and
an ester (B) of polyhydric alcohol(s) with aliphatic monocarboxylic acid(s), wherein
the polymer (A) is a polymer which is obtained by polymerizing monomer(s) consisting of at least one monomer of monosubstituted ethylenes and disubstituted ethylenes, and in which a ratio of a monomer represented by the following general formula (I):
wherein R 1 represents an alkyl group having 1 to 5 carbon atoms, R 2 represents hydrogen or an alkyl group having 1 to 4 carbon atoms, and the sum of carbon numbers in R 1 and R 2 is 2 to 5, is 75 to 100% by mass based on a total mass of monomers constituting the polymer.
2. The refrigerating machine oil composition according to claim 1 , wherein a mass ratio between the polymer (A) and the ester (B) is 3/97 to 45/55 (the polymer (A)/the ester (B)).
3. The refrigerating machine oil composition according to claim 1 , wherein R 1 is an alkyl group having 1 to 4 carbon atoms, R2 is hydrogen or a methyl group, and the sum of carbon numbers in R 1 and R 2 is 2 to 5.
4. The refrigerating machine oil composition according to claim 1 , wherein, in the polymer (A), the ratio of a monomer represented by the general formula (I) is 100% by mass based on the total mass of monomers constituting the polymer.
5. The refrigerating machine oil composition according to claim 1 , wherein the ester (B) is an ester of at least one of pentaerythritol and dipentaerythritol with aliphatic monocarboxylic acid(s) having 4 to 9 carbon atoms.
6. The refrigerating machine oil composition according to claim 1 , wherein a weight average molecular weight of the polymer (A) is 500 to 11000.
7. A working fluid composition for a refrigerating machine, comprising the refrigerating machine oil composition according to claim 1 and difluoromethane.