LUBRICATING OIL AND COMPOSITION FOR REFRIGERATING MACHINE, AND REFRIGERATING MACHINE

摘要

A lubricating oil for refrigerating machines mainly comprises polyoxyalkylene compounds represented by the following formula (I); <IMG> wherein A represents a residue obtained from a compound which has both a heterocyclic ring having an ether linkage and hydroxyl groups in the molecule by eliminating the hydroxyl groups from the compound; R1 and R2 are each an alkylene group; R3 is an alkyl group; R4 is hydrogen atom or an alkyl group; a and b are each a positive integer and ~, m and n are each an integer of 0 or more with the proviso that a~ ~ + b ~ m = 2 to 100 and ~ + m + n = 2 to 20; further, the polyoxyalkylene compounds satisfying the following two conditions: (a) the compounds have a hydroxyl value ranging from 0 mgKOH/g to 30.0 mgKOH/g and (b) a ratio of butylene groups of all alkylene groups represented by R1 and R2 to the all alkylene groups satisfies the following formula (1) 0.5 ~ p/(p + q) .ltoreq. 1.0 (1) wherein "p" is the number of butylene groups, "q" is the number of alkylene groups excluding the butylene groups.