abstract |
The present invention provides esters of hindered polyols most preferably pentaerythritol with a carboxylic acid mixture comprising at least some iso-pentanoic acid together with iso-nonanoic acid such as adipic acid and dibasic acids such as adipic acid. A high quality lubricant for compressors of welded sealed household air conditioners and cooling using chlorine-free hydrofluorocarbon refrigerant working fluids provided by the mixture. |