HETEROCYCLISCHE ESTER ENTHALTENDE ZUSAMMENSETZUNGEN UND IHRE VERWENDUNG ALS ZUSAETZE FUER SCHMIERMITTEL ZUR VERHINDERUNG VON BLEIABLAGERUNGEN IN VERBRENNUNGSMOTOREN

Combinations of substituted carboxylic (especially succinic) acid esters and heterocyclic condensation products of said substituted carboxylic acids are useful in lubricants for inhibitors of "lead paint" deposition in internal combustion engines. Especially useful are compositions comprising a major proportion of a pentaerythritol ester of an alkenyl succinic acid in which the alkenyl group contains at least about 30 carbon atoms, and a minor proportion of a heterocyclic condensation product of said alkenyl succinic acid derived from a 5-membered ring heterocycle containing at least two ring hetero atoms separated by a single carbon atom, at least one of said hetero atoms being nitrogen.