Patent ID: 7727944

Claim:
A method for lubricating a mechanical device comprising elastomeric materials, comprising supplying thereto a lubricant formulation comprising an oil of lubricating viscosity and: (A) at least one ester-containing phenolic antioxidant seal-conditioning agent represented by the formula wherein R is an alkyl group of 2 to 6 carbon atoms; and (B) at least one second seal-conditioning agent comprising a sulfolane represented by the general formula wherein R 1 is a hydrocarbon group having at least about 4 carbon atoms and each of R 2 and R 3 is independently hydrogen or an alkyl group of 1 to about 7 carbon atoms; wherein the amounts of components (A) and (B) are in the ratio of about 5:95 to about 95:5 by weight and the total amount of components (A) and (B) is about 1 to about 15 percent by weight of the composition.