Lubricating compositions with lactam or thiolactam-containing copolymers

摘要

There are disclosed novel lubricating compositions containing a major proportion of a lubricating oil and a minor proportion of an oil soluble polymer additive, and possibly other additives, wherein said polymer additive is a copolymer of ethylene, a monoolefin having 3 to 6 carbon atoms or a monoolefin having 3 to 6 carbon atoms and a non-conjugated diene with one or more specific nitrogenous monomers, said polymer having a reduced viscosity, measured in decalin at 135 DEG C., comprised between 0.5 and 2 and a polydispersity lower than 5.