Patent ID: 7871966

Claim:
A lubricating oil composition comprising a lubricant base oil containing a base oil (X) of which % C P is 70˜97, % C A is 1 or less, % C N is 3˜30, % C P /% C N is 4 or more, viscosity index is 115 or more, NOACK evaporation is 8˜16 mass %, and CCS viscosity at −35° C. is 3000 mPa·s or less, wherein said lubricant base oil, to total mass of the composition, contains following components (A)˜(D): (A) 0.01˜10 mass % of ashless friction modifier; (B) 0.01˜0.2 mass % of phosphorus-containing anti-wear agent as phosphorous content; (C) 0.01˜1 mass % of metallic detergent as metal content; and (D) 0.01˜0.4 mass % of ashless dispersant having 3000˜20000 of weight-average molecular weight as nitrogen content, wherein said (A) component is one or more compound selected from the group consisting of: aliphatic polyamine, imide compound, an ester of fatty acid with aliphatic polyvalent alcohol, fatty acid amide, fatty acid, aliphatic alcohol, aliphatic ether, respectively having at least one of hydrocarbon group of carbon number 6˜30 within the molecule, compounds containing nitrogen represented by the following general formulas (1) and (2), and acid modification derivatives thereof, and wherein said (B) component is one compound selected from the group consisting of: a phosphorus compound represented by the following general formula (5), a phosphorus compound represented by the following general formula (6), metal salts thereof, amine salts thereof, and derivatives thereof; wherein in the general formula (1), R 1 is hydrocarbon group of carbon number 1˜30 or functional hydrocarbon group of carbon number 1˜30; R 2 and R 3 are respectively hydrocarbon group of carbon number 1˜30, functional hydrocarbon group of carbon number 1˜30 or hydrogen; X 1 is oxygen or sulfur; wherein in the general formula (2), R 4 is hydrocarbon group of carbon number 1˜30 or functional hydrocarbon group of carbon number 1˜30; R 5 ˜R 7 are respectively hydrocarbon group of carbon number 1˜30, functional hydrocarbon group of carbon number 1˜30 or hydrogen; wherein in the formula (5), X 2 , X 3 , and X 4 respectively indicate oxygen atom or sulfur atom; R 16 , R 17 , and R 18 respectively indicate hydrogen atom or hydrocarbon group of carbon number 1˜30; wherein in the formula (6), all of X 5 ˜X 8 are oxygen atom (one or two of X 5 , X 6 , and X 7 may be chain of single bond or (poly) oxyalkylene group; and R 19 , R 20 , and R 21 respectively indicate hydrogen atom or hydrocarbon group of carbon number 1˜30.