Lubricating oils comprising polyoxyalkylenglycol derivates

摘要

A composition is disclosed which comprises a lubricating oil and a refrigerant, wherein the lubricating oil comprises a polyalkyleneglycol derivative of the formula (I): RX(R^aO)_x(R^bO)_y(R^cO)_zR^d, wherein: X-O or S, R is a C₃ to C₁₅ substituent comprising a heterocyclic ring, in which the heteroatom(s) in said ring is (are) oxygen and/or sulphur, R^a is a C₂ alkylene group, R^b is a C₃ alkylene group, R^c is a C₄ alkylene group, R^d is the same as R, or is H, a C₁-C₂₀ alkyl or a C₁-C₂₀ acyl, x, y, z are each independently 0 or an integer of 100 or less, and x+y+z=4 to 100, but excluding compositions where the refrigerant is halogen-free and R contains a carbonate group. The use of borate esters as dehydrogenating agents in conjunction with the above lubricating oils is also disclosed.