| abstract |
A high quality lubricant for compressors operated during at least part of their compression cycle at temperatures above normal human comfort temperatures, such as most automotive air conditioners, especially those using chlorine free hydrofluorocarbon refrigerant working fluids, is provided by mixed esters of hindered polyols, most desirably pentaerythritol, with a mixture of carboxylic acids including at least some iso-pentanoic acid along with either or both of iso-nonanoic acid and dibasic acids such as adipic. |