Lubricating oil composition for internal combustion engines

Abstract

Provided is a lubricating oil composition for an internal combustion engine, including: an organic molybdenum compound as a component (A); a base oil having a kinematic viscosity at 100 ° C. of 25 mm 2 /s or more as a component (B); and a base oil having a kinematic viscosity at 100° C. of less than 12.5 mm 2 /s as a component (C), in which the composition has a kinematic viscosity at 100° C. of 5 mm 2 /s to 12.5 mm 2 /s and a phosphorus content of 800 ppm or less.

1 . A lubricating oil composition for an internal combustion engine, comprising:
 an organic molybdenum compound as a component (A);   a base oil having a kinematic viscosity at 100° C. of 25 mm 2 /s or more as a component (B); and   a base oil having a kinematic viscosity at 100° C. of less than 12.5 mm 2 /s as a component (C),   wherein the composition has a kinematic viscosity at 100° C. of 5 mm 2 /s to 12.5 mm 2 /s and a phosphorus content of 800 ppm or less.   
     
     
         2 . The lubricating oil composition for an internal combustion engine according to  claim 1 , wherein the lubricating oil composition for an internal combustion engine contains 200 to 2,000 ppm in terms of a molybdenum content of the component (A), 1 to 30 mass % of the component (B), and 50 to 95 mass % of the component (c) with respect to a total amount thereof. 
     
     
         3 . The lubricating oil composition for an internal combustion engine according to  claim 1 , wherein the component (A) comprises a compound represented by the following general formula (1): 
       
         
           
           
               
               
           
         
       
       where R 1  to R 4  each represent a linear or branched alkyl group or alkenyl group having 4 to 18 carbon atoms, and X 1  to X 4  each represent an oxygen atom or a sulfur atom. 
     
     
         4 . The lubricating oil composition for an internal combustion engine according to  claim 1 , wherein the lubricating oil composition for an internal combustion engine further comprises one or more kinds of additives selected from the group consisting of a viscosity index improver, a pour point depressant, an extreme-pressure agent, an oiliness improver, an antioxidant, a metal-based detergent, an ashless dispersant, a metal deactivator, a rust inhibitor, and an anti-foaming agent. 
     
     
         5 . The lubricating oil composition for an internal combustion engine according to  claim 4 , wherein the lubricating oil composition for an internal combustion engine contains 300 to 800 ppm in terms of a phosphorus content of a zinc dithiophosphate as an extreme-pressure agent with respect to a total amount thereof. 
     
     
         6 . The lubricating oil composition for an internal combustion engine according to  claim 2 , wherein the component (A) comprises a compound represented by the following general formula (1): 
       
         
           
           
               
               
           
         
       
       where R 1  to R 4  each represent a linear or branched alkyl group or alkenyl group having 4 to 18 carbon atoms, and X 1  to X 4  each represent an oxygen atom or a sulfur atom. 
     
     
         7 . The lubricating oil composition for an internal combustion engine according to  claim 2 , wherein the lubricating oil composition for an internal combustion engine further comprises one or more kinds of additives selected from the group consisting of a viscosity index improver, a pour point depressant, an extreme-pressure agent, an oiliness improver, an antioxidant, a metal-based detergent, an ashless dispersant, a metal deactivator, a rust inhibitor, and an anti-foaming agent. 
     
     
         8 . The lubricating oil composition for an internal combustion engine according to  claim 3 , wherein the lubricating oil composition for an internal combustion engine further comprises one or more kinds of additives selected from the group consisting of a viscosity index improver, a pour point depressant, an extreme-pressure agent, an oiliness improver, an antioxidant, a metal-based detergent, an ashless dispersant, a metal deactivator, a rust inhibitor, and an anti-foaming agent.