| abstract |
Esters and mixtures of esters of polyhydric alcohols. e.g.. of pentaerythritol, in which at least 22 number percent of the acyl groups in the esters are either branched or contain no more than six carbon atoms, are effective lubricants and/or lubricant base stocks for chlorine-free fluorocarbon refrigerant heat transfer fluids, particularly for chlorine-free heat transfer fluids such as Refrigerant 134a (1,1,1,2-tetrafluoroethane). |