Patent ID: 8618031

Claim:
A method for improving the resistance to deposit formation of High Performance Category turbine oil comprising a synthetic polyol ester base oil, one or more of a polymeric aryl aminic antioxidant and IDP antiwear additive of the formula: wherein n=1 to 7, Ph is phenyl, the IDP being present in an amount in the range of 2.09 to 3.28 wt % based on active ingredient, wherein the resistance to deposit formation as measured by the Vapor Phase Coker Test at 700Â° F. of the turbine oil is at least 30 mg lower than the deposit formation of turbine oils containing the same ester base stock and polymeric aryl aminic antioxidant, but containing tricresyl phosphate in place of the IDP, and wherein the one or more polymeric aryl aminic antioxidant are present in an amount in the range 7 to 10 wt % as delivered.