Lubricating oil for refrigerator, hydraulic fluid composition for refrigerator and method for lubricating of refrigerator

Abstract

The invention provides a lubricating oil for refrigerators, comprising (a) at least one ester represented by the formula (1) wherein R1 is C1 to C18 straight-chain alkyl or C3 to C18 branched-chain alkyl; R2 is H, C1 to C18 straight-chain alkyl or C3 to C18 branched-chain alkyl; with the proviso that the total number of carbons contained in the alkyls represented by R1 and R2 is 2 to 18 and that when R2 is H, R1 is branched-chain alkyl; and R3 is C1 to C20 straight-chain alkyl, C3 to C20 branched-chain alkyl or C3 to C10 cycloalkyl, optionally in combination with (b) at least one member selected from the group consisting of fatty acid polyol esters, phthalic acid esters, alicyclic dicarboxylic acid esters, polyvinyl ethers, hydrocarbon oils and polyalkylene glycols; as well as a method for lubricating a refrigerator using such a lubricating oil, and a working fluid composition for refrigerators comprising (I) component (a) or components (a) and (b) and (II) a refrigerant.

Dependencies are inferred from the claim text.