Patent ID: 9062269
Filing Date: 2015-06-23
Classification: C10M,C10N

Abstract:
1. A method for improving thermo-oxidative stability and elastomer compatibility in an apparatus lubricated with a lubricating oil by using as the lubricating oil a formulated oil comprising a lubricating oil base stock; wherein the lubricating oil base stock comprises from about 25 to 50 wt. % of a multi-aromatic base stock of the formula: wherein each R 1 is the same or different and is a terminal group, each R 2 is the same or different and represents a substituted or unsubstituted aromatic moiety; each X is a linking moiety that is carbon-carbon single bond or a linking group, n is a number from 1 to 2000, and the ratio of the total number of aromatic ring carbon atoms to aliphatic carbon atoms in said formula is greater than 0.32:1; wherein the multi-aromatic base stock has a kinematic viscosity greater than 20 mm 2 /s at 100° C.; and wherein thermo-oxidative stability and elastomer compatibility are improved as compared to thermo-oxidative stability and elastomer compatibility achieved using a lubricating oil base stock other than the multi-aromatic base stock.