JP2007063336A5 - - Google Patents

Claims (29)

A lubricating oil composition comprising the following ingredients:
a) a major amount of base oil of lubricating viscosity;
b) an overbased alkaline earth metal alkylaryl sulfonate detergent having a total base number (TBN) of about 0.1 to 10% by weight of about 25 to 500;
c) about 0.02 to 10% by weight of an oxymolybdenum-containing complex;
d) about 0.1 to 5.0% by weight of an ester friction modifier, and e) about 0.2 to 10.0% by weight of a diphenylamine compound, a sulfur-containing compound, and a mixture thereof. Antioxidants,
[However, the total concentration of the oxymolybdenum-containing complex and the antioxidant is at least 1.3% by weight based on the total weight of the lubricating oil composition, and the total lubricating oil composition has a phosphorus content of the lubricating oil composition Of 0.08% by mass or less based on the total mass of   The lubricating oil composition according to claim 1, wherein the total concentration of the oxymolybdenum-containing complex and the antioxidant is at least 1.45% by weight based on the total weight of the lubricating oil composition.   The lubricating oil composition according to claim 1, wherein the phosphorus content is 0.06% by mass or less based on the total mass of the lubricating oil composition.   The lubricating oil composition according to claim 1, wherein the phosphorus content is 0.05% by mass or less based on the total mass of the lubricating oil composition.   The lubricating oil composition according to claim 1, wherein the alkaline earth metal is calcium. The sulfonate detergent is derived from a C _14-40 carbon linear normal alpha olefin, wherein at least 13 mol% of the alkyl groups are attached to the aryl group at the 1- or 2-position of the alkyl group. 2. The lubricating oil composition according to 1.   The lubricating oil composition of claim 1, wherein the TBN is from about 250 to 500.   The lubricating oil composition of claim 1, wherein the TBN is from about 300 to 450.   The lubricating oil composition of claim 1, further comprising an oil-soluble phosphorus-containing antiwear compound.   The lubricating oil according to claim 9, wherein the oil-soluble phosphorus-containing antiwear compound is selected from the group consisting of metal dithiophosphates, phosphorus esters, amine phosphates and phosphinates, sulfur-containing phosphorus esters, phosphorus amides and phosphonamides. Composition.   The lubricating oil composition according to claim 10, wherein the phosphoric ester is selected from the group consisting of phosphoric ester, phosphonic ester, phosphinic ester, phosphine oxide, phosphorous ester, phosphonous ester, phosphinic ester and phosphine. object.   The lubricating oil composition according to claim 10, wherein the sulfur-containing phosphorus ester is selected from the group consisting of phosphoro monothionate and phosphoro dithionate.   The lubricating oil composition according to claim 10, wherein the oil-soluble phosphorus-containing antiwear compound is a metal dithiophosphate.   The lubricating oil composition of claim 13, wherein the metal dithiophosphate is zinc dialkyldithiophosphate.   Nitrogen-containing compounds used in oxymolybdenum-containing complexes include succinimides, carboxylic acid amides, hydrocarbon monoamines, hydrocarbon polyamines, Mannich bases, phosphorus amides, thiolinamides, phosphonamides, dispersant-type viscosity index improvers, and mixtures thereof The lubricating oil composition according to claim 1, which is selected from the group consisting of:   The lubricating oil composition according to claim 15, wherein the nitrogen-containing compound is succinimide, and the oxymolybdenum-containing complex is molybdenum-succinimide.   The lubricating oil composition according to claim 16, wherein the molybdenum succinimide is molybdenum sulfide succinimide.   The lubricating oil composition according to claim 16, wherein the molybdenum succinimide is an unsulfurized molybdenum succinimide.   The lubricating oil composition of claim 1, wherein the ester friction modifier is a borated glycerol monooleate ester.   The lubricating oil composition according to claim 1, wherein the antioxidant is a diphenylamine type antioxidant.   The lubricating oil composition according to claim 20, wherein the diphenylamine-type antioxidant is selected from the group consisting of alkylated diphenylamine, phenyl-α-naphthylamine and alkylated-α-naphthylamine.   The lubricating oil composition according to claim 21, wherein the diphenylamine-type antioxidant is an alkylated diphenylamine.   The lubricating oil composition according to claim 1, wherein the antioxidant is a sulfur-containing compound.   The lubricating oil composition according to claim 23, wherein the sulfur-containing compound is selected from the group consisting of sulfurized ester compounds, sulfurized olefins, and dithiocarbamates.   The lubricating oil composition according to claim 24, wherein the sulfur-containing compound is dithiocarbamate.   The lubricating oil composition of claim 1, further comprising an alkenyl succinimide dispersant derived from a polyalkylene having an average molecular weight of about 450 to 3000.   27. The lubricating oil composition of claim 26, wherein the polyalkylene is a polyisobutenyl having an average molecular weight of about 900 to 2300.   28. A lubricating oil composition according to claim 27, wherein the polyisobutenyl succinimide is post-treated with ethylene carbonate. A method for improving the fuel economy of a gasoline internal combustion engine comprising operating the engine with a lubricating oil composition according to any one of claims 1 to 28 .