Mineral oil lubricating compositions

Claim 1

A LUBRICATING OIL COMPOSTION COMPRISING A MINERAL OIL OF LUBRICATING GRADE IN MAJOR AMOUNT BASED ON THE WEIGHT OF THE COMPOSITION, A SMALL AMOUNT OF AN OILSOLUBLE HALF AMIDE-ALIPHATIC HYDROCARBON ESTER OF AN ALIPHATIC HYDROCARBON DICARBOXYLIC ACID, SAID HALF AMIDEESTER BEING CHARACTERIZED IN THAT ITS AMIDE PORTION CONTAINS AN ALIPHATIC HYDROCARBON GROUP AS A SUBSTITUENT FOR AT LEAST ONE OF THE HYDROGEN ATOMS LINKED TO THE AMIDE NITROGEN ATOM, AND A SMALL AMOUNT OF AN OIL-SOLUBLE HETEROCYCLIC CARBON COMPOUND IN WHICH NITROGEN IS THE HETER-ATOM, SAID COMPOSITION BEING CHARACTERIZED BY CONTAINING FROM ABOUT 0.02 TO ABOUT 1.0% AS THE COMBINED WEIGHT OF SAID HALF AMIDE-ESTER AND HETEROCYCLIC COMPOUND IN A WEIGHT RATIO OF SAID HALF AMIDE-ESTER TO HETEROCYCLIC COMPOUND TO IMPART TO SAID COMPOSITION RUST-PREVENTIVE CHARACTERISTS IN EXCESS OF THE INDIVIDUAL EFFECTIVENESS OF SAID HALF AMIDE-ESTER AND HETEROCYCLIC COMPOUND, SAID HALF-AMIDE ESTER BEING A COMPOUND IN WHICH ONE CARBOXYL GROUP OF AN ALIPHATIC DICARBOXYLIC ACID FROM THE GROUP CONSISTING OF SUCCINIC, GLUTARIC, ADIPIC AND SUBERIC ACIDS IS ESTERIFIED WITH AN ALIPHATIC RADICAL CONTAINING ABOUT 4 TO ABOUT 20 CARBON ATOMS AND IN WHICH THE AMIDE PORTION OF THE ESTER CONTAINS AN ALKYL GROUP OF ABOUT 4 TO ABOUT 20 CARBON ATOMS SUBSTITUTED FOR AT LEAST ONE OF THE NITROGEN-LINKED HYDROGEN ATOMS, AND SAID HETEROCYCLIC COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF PIPERIDENE, PYRROLIDINE AND 1-ETHYL PIPERIDINE.