LUBRICATING OIL FOR INTERNAL COMBUSTION ENGINE Russian patent published in 1994 - IPC

FIELD: internal combustion engines. SUBSTANCE: lubricating oil contains, mass % : imperfect ester of fatty acid and polihydric alcohol 0.01-2.00, product of interaction of polyisobutylene succinic acid and alkelenepolyamine 0.01-0.15, metal salt of dialkyldithiophosphoric acid 0.01-2.00, petroleum oil to 100. Mentioned above product is prepared on the base of polyisobutylene succinic acid containing 1,3-4 groups of succinic acid per equivalent mass of polyisobutylene, its numerical mean molecular weight being 1300-1500, ratio mass mean molecular weight and numerical mean molecular weight being 1.5-4.5. Quantity of alkylenepolyamine is 1-2 molar equivalents per 1 equivalent of acid. Said salt dialkyldithiophosphoric acid contains isopropyl or secondary butyl, another alkyl contains 5-13 carbon atoms, molar content of isopropyl or secondary butyl groups being 10-90% . Metal of II group of periodic table, namely Al, Sn, Fe, Co, Pb, Mo, Mn, Ni, or Cu forms said salt. EFFECT: improves lubricating capacity. 3 cl, 2 tbl