Lubricating oils for fluorinated hydrocarbon-based refrigerant type compressor, lubricating method for a such compressor, and working fluid compositions containing said lubricating oils for compressor.

摘要

A lubricating oil for a fluorinated hydrocarbon-based refrigerant type compressor, said lubricating oil having a kinematic viscosity at 100 DEG C being 7 to 30 cSt and comprising, as a base oil, at least one polyoxyalkylene glycol derivative represented by the following formula (I): R1-0-[(PO)p(EO<1>)q]-(EO<2>)r-R2 (I> in which R1 is an alkyl group having 1 to 4 carbon atoms, R2 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, PO is an oxypropylene group, EO<1> and EO<2> are oxyethylene groups, p, q and r are average polymerization degrees of PO, EO<1> and EO<2>, respectively, [(PO)p(EO<1>)q] is a random copolymer group of PO and EO<1>, (EO<2>)r is a block polymer group of EO<2>, p/(p + q) is 0.70 to 0.95, and r/(p + q + r) is 0.03 to 0.30. A lubricating method and a working fluid composition for the fluorinated hydrocarbon-based refrigerant type compressor are also disclosed.