Lubricant composition

Abstract

A lubricating oil composition is used in an internal combustion engine that uses a fuel containing at least one fat and oil selected from a group consisting of natural fat and oil, hydrotreated natural fat and oil, transesterified natural fat and oil and hydrotreated transesterified natural fat and oil. A polyol ester having a kinematic viscosity in the range of 3 to 8 mm 2 /s at 100 degrees C and/or a polybasic acid ester having a kinematic viscosity in the range of 3 to 8 mm 2 /s at 100 degrees C is mixed in an amount in the range of 5 to 30 mass % of a total amount of the lubricating oil composition as a base oil of lubricating oil.

1 . A lubricating oil composition comprising a base oil in an amount in the range of 5 to 30 mass % of a total amount of the lubricating oil composition, wherein said base oil comprises a polyol ester having a kinematic viscosity in the range of 3 to 8 mm 2 /s at 100 degrees C. and/or a polybasic acid ester having a kinematic viscosity in the range of 3 to 8 mm 2 /s at 100 degrees C. 
     
     
         2 . The lubricating oil composition according to  claim 1 , further comprising
 a boron derivative of polybutenyl succcinimide compound including a polybutenyl group that has a number average molecular weight of 500 to 3500 and possessing a mass ratio (B/N) between boron (B) and nitrogen (N) of 0.5 or more, and   an alkaline earth metal detergent.   
     
     
         3 . The lubricating oil composition according to  claim 1 , further comprising
 a sulfated ash in an amount of 1.1 mass % or less in reference to the total amount of the lubricating oil composition.   
     
     
         4 . The lubricating oil composition according to  claim 1 , further comprising
 a phenol-based antioxidant and/or an amine-based antioxidant in an amount of from 0.3 mass % or more in reference to the total amount of the lubricating oil composition.   
     
     
         5 . The lubricating oil composition according to  claim 2 , wherein
 the boron derivative of the polybutenyl succinimide compound has a boron content of 0.01 mass % or more in reference to the total amount of the lubricating oil composition.   
     
     
         6 . The lubricating oil composition according to  claim 1 , further comprising
 sulfur in an amount of 0.5 mass % or less in reference to the total amount of the lubricating oil composition.   
     
     
         7 . A method of lubricating an internal combustion engine, comprising
 adding the lubricating oil composition of  claim 1  to an internal combustion engine, wherein   said internal combustion engine comprises a fuel that comprises at least one fat and oil selected from a group consisting of natural fat and oil, hydrotreated natural fat and oil, transesterified natural fat and oil and hydrotreated transesterified natural fat and oil.   
     
     
         8 . The method of lubricating an internal combustion engine according to  claim 7 , wherein the lubricating oil composition further comprises
 a boron derivative of polybutenyl succcinimide compound including a polybutenyl group that has a number average molecular weight of 500 to 3500 and possessing a mass ratio (B/N) between boron (B) and nitrogen (N) of 0.5 or more, and   an alkaline earth metal detergent.   
     
     
         9 . The method of lubricating an internal combustion engine according to  claim 8 , wherein the lubricating oil composition further comprises a sulfated ash in an amount of 1.1 mass % or less in reference to the total amount of the lubricating oil composition. 
     
     
         10 . The method of lubricating an internal combustion engine according to  claim 8 , wherein the lubricating oil composition further comprises a phenol-based antioxidant and/or an amine-based antioxidant in an amount of from 0.3 mass % or more in reference to the total amount of the lubricating oil composition. 
     
     
         11 . The method of lubricating an internal combustion engine according to  claim 8 , wherein the boron derivative of the polybutenyl succinimide compound of the lubricating oil composition has a boron content of 0.01 mass % or more in reference to the total amount of the lubricating oil composition. 
     
     
         12 . The method of lubricating an internal combustion engine according to  claim 9 , wherein the lubricating oil composition comprises sulfur in an amount of 0.5 mass % or less in reference to the total amount of the lubricating oil composition. 
     
     
         13 . An internal combustion engine, comprising the lubricating oil composition of  claim 1  and a fuel that comprises at least one fat and oil selected from a group consisting of natural fat and oil, hydrotreated natural fat and oil, transesterified natural fat and oil and hydrotreated transesterified natural fat and oil.