METHOD FOR IMPROVING NITRILE SEAL COMPATIBILITY WITH LUBRICATING OILS

摘要

Provided is a method of improving nitrile seal compatibility with a lubricating oil in an engine lubricated with the lubricating oil. The method includes using as the lubricating oil a formulated oil comprising a lubricating oil base stock as a major component and an alkylated aromatic base stock as a minor component. Nitrile seal compatibility is improved as compared to nitrile seal compatibility achieved using a lubricating oil containing a minor component other than the alkylated aromatic base stock, e.g., an ester. A lubricating engine oil comprising a lubricating oil base stock as a major component and an alkylated aromatic base stock as a minor component. The alkylated aromatic base stock is present in an amount sufficient for the lubricating oil to exhibit improved nitrile seal compatibility as compared to nitrile seal compatibility achieved using a lubricating oil containing a minor component other than the alkylated aromatic base stock.