Lubricant oil composition for internal combustion engine

Abstract

A lubricant oil composition for internal combustion engines with which further reduction of friction can be achieved to provide excellent fuel efficiency is provided. (A) A lubricant oil base oil having a kinematic viscosity at 100° C. of 2.0 to 5.0 mm 2 /s; (B) a molybdenum-based friction modifier in an amount of 0.005 to 0.2 mass % in terms of the mass of the molybdenum relative to the total mass of the composition; (C) a metal-based detergent in an amount of 0.01 to 1 mass % in terms of the mass of the metal relative to the total mass of the composition; and (D) 0.01 to 10 mass % of at least one compound selected from amino acids having a C 6-24 alkyl, alkenyl, or acyl group, and/or derivatives of the amino acids.

1 . A lubricant oil composition for internal combustion engines,
 the lubricant oil composition comprising:   (A) a lubricant oil base oil having a kinematic viscosity at 100° C. of 2.0 to 5.0 mm 2 /s;   (B) a molybdenum-based friction modifier in an amount of 0.005 to 0.2 mass % in terms of the mass of the molybdenum relative to the total mass of the composition;   (C) a metal-based detergent in an amount of 0.01 to 1 mass % in terms of the mass of the metal relative to the total mass of the composition; and   (D) 0.01 to 10 mass % of at least one compound selected from amino acids having a C 6-24  alkyl, alkenyl, or acyl group, and/or derivatives of the amino acids.   
     
     
         2 . The lubricant oil composition for internal combustion engines according to  claim 1 , wherein the (C) metal-based detergent contains at least a salicylate-based detergent. 
     
     
         3 . The lubricant oil composition for internal combustion engines according to  claim 1 , wherein the lubricant oil composition has a kinematic viscosity at 100° C. of 4.0 to 12.5 mm 2 /s. 
     
     
         4 . The lubricant oil composition for internal combustion engines according to  claim 1 , further comprising zinc dialkyl dithiophosphate (ZnDTP) in an amount of 0.02 to 0.2 mass % in terms of the mass of the phosphorus relative to the total mass of the composition. 
     
     
         5 . The lubricant oil composition for internal combustion engines according to  claim 2 , wherein the lubricant oil composition has a kinematic viscosity at 100° C. of 4.0 to 12.5 mm 2 /s. 
     
     
         6 . The lubricant oil composition for internal combustion engines according to  claim 2 , further comprising zinc dialkyl dithiophosphate (ZnDTP) in an amount of 0.02 to 0.2 mass % in terms of the mass of the phosphorus relative to the total mass of the composition. 
     
     
         7 . The lubricant oil composition for internal combustion engines according to  claim 3 , further comprising zinc dialkyl dithiophosphate (ZnDTP) in an amount of 0.02 to 0.2 mass % in terms of the mass of the phosphorus relative to the total mass of the composition. 
     
     
         8 . The lubricant oil composition for internal combustion engines according to  claim 5 , further comprising zinc dialkyl dithiophosphate (ZnDTP) in an amount of 0.02 to 0.2 mass % in terms of the mass of the phosphorus relative to the total mass of the composition.