Abstract: A refrigerating machine oil for use with a hydrofluorocarbon refrigerant in a refrigerator, which comprises at least one member selected from the group consisting of hydrocarbon compounds represented by the following general formulas (1), (2) and (3) ##STR1## (wherein R represents an alkylene group or alkenylene group having 1 to 8 carbon atoms; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may be the same or different and are each a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, the total number of carbon atoms of R, R.sup.1, R.sup.2 R.sup.3 and R.sup.4 being within a range of 1 to 8; and R.sup.6, R.sup.7, R.sup.8 and R.sup.9 may be the same or different and are each a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, the total number of carbon atoms of R.sup.6, R.sup.7, R.sup.8 and R.sup.9 being within a range of 1 to 10).

Abstract: A lubricating oil for refrigerating machines comprises polyoxyalkylene compounds represented by the formula (I): ##STR1## Wherein A is a residue obtained from a compound which has both a heterocyclic ring having an ether linkage therein and hydroxyl groups by eliminating the hydroxyl groups from the compound; R.sup.1 and R.sup.2 are each an alkylene group; R.sup.3 is an alkyl group; R.sup.4 is hydrogen atom or an alkyl group; a and b are each a positive integer and l, m, and n are each an integer of 0 or more; and a.multidot.1+b.multidot.m=2 to 100 and l+m+n=2 to 20; further,the polyoxyalkylene compounds have a hydroxyl value ranging from 0 to 30.0 mgKOH/g and satisfies the following formula (1)0.5<p/(p+q)<1.0 (1)wherein p is the number of butylene groups represented by R.sup.1 and R.sup.2, and q is the number of all alkylene groups excluding the butylene groups.

Abstract: A refrigerating machine oil for use with a hydrofluorocarbon refrigerant in a refrigerator, which comprises at least one member selected from the group consisting of hydrocarbon compounds represented by the following general formulas (1), (2) and (3) ##STR1## (wherein R represents an alkylene group or alkenylene group having 1 to 8 carbon atoms; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may be the same or different and are each a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, the total number of carbon atoms of R, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 being within a range of 1 to 8; and R.sup.6, R.sup.7, R.sup.8 and R.sup.9 may be the same or different and are each a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, the total number of carbon atoms of R.sup.6, R.sup.7, R.sup.8 and R.sup.9 being within a range of 1 to 10).