Patent ID: 6245254
Filing Date: 2001-06-12
Classification: C09K,C10M,C10N

Abstract:
A working fluid composition consisting essentially of:(A) a heat transfer fluid consisting of a mixture of at least two hydrofluoralkanes selected from the group consisting of difluoromethane, 1,1,1,2-tetrafluoroethane and pentafluoroethane; and(B) sufficient to provide lubrication of a lubricant which is at least partially soluble in each component of the heat transfer fluid and in said heat transfer fluid, said lubricant being selected from the group consisting of esters of general formula: ##STR3##whereinR.sup.2 is the hydrocarbon radical remaining after removing the hydroxyl groups from pentaerythritol or dipentaerythritol;each R.sup.3 is independently, a linear alkyl group of 3 to 10 carbons or a branched alkyl group of 6 to 12 carbons; andp is an integer of 4 or 6, said lubricant being characterized by its thermal stability, hydrolytic stability and solubility and miscibility in said heat transfer fluid.