Lubricating oil composition

Abstract

A lubricating oil composition that can suppress wear of bearings and the like and scoring of gear teeth surfaces and the like even at low viscosity. A lubricating oil composition that includes a lubricating oil base oil, a sulfur-based extreme pressure agent, and a phosphorus-based extreme pressure agent, wherein the lubricating oil composition is characterized in that: the quantity of active sulfur in the sulfur-based extreme pressure agent is 5-30% by mass; the sulfur-based extreme pressure agent is included in the composition at a quantity of 5-15% by mass relative to the mass of the entire lubricating oil composition; and the phosphorus-based extreme pressure agent is included in the composition at a quantity of 1.5-8% by mass relative to the mass of the entire lubricating oil composition.

1 . A lubricating oil composition comprising:
 (A) a lubricating base oil;   (B) a sulfur-based extreme pressure agent; and   (C) a phosphorus-based extreme pressure agent,   wherein the sulfur-based extreme pressure agent (B) has an active sulfur content of 5 to 30% by weight,   the sulfur-based extreme pressure agent (B) is contained in the composition in an amount of 5 to 15% by weight, based on a total weight of the lubricating oil composition, and   the phosphorus-based extreme pressure agent (C) is contained in the composition in an amount of 1.5 to 8% by weight, based on the total weight of the lubricating oil composition.   
     
     
         2 . The lubricating oil composition according to  claim 1 , wherein the sulfur-based extreme pressure agent is a sulfurized olefin. 
     
     
         3 . The lubricating oil composition according to  claim 1 , wherein the phosphorus-based extreme pressure agent (C) is at least one selected from phosphate esters, acid phosphate esters, phosphite esters, acid phosphite esters, thiophosphate esters, acid thiophosphate esters, thiophosphite esters, acid thiophosphite esters, amine salts of acid phosphate esters, amine salts of acid phosphite esters, amine salts of acid thiophosphate esters, and amine salts of acid thiophosphite esters. 
     
     
         4 . The lubricating oil composition according to  claim 3 , wherein the phosphorus-based extreme pressure agent (C) is at least one selected from amine salts of acid phosphate esters, amine salts of acid phosphite esters, amine salts of acid thiophosphate esters, and amine salts of acid thiophosphite esters. 
     
     
         5 . The lubricating oil composition according to  claim 1 , which has a kinematic viscosity at 100° C. of 3 to 40 mm 2 /s. 
     
     
         6 . The lubricating oil composition according to  claim 1 , wherein the lubricating base oil (A) is at least partially a GTL (Gas to Liquid)-derived based oil. 
     
     
         7 . The lubricating oil composition according to  claim 1 , wherein the lubricating base oil (A) is at least partially a poly-α-olefin (PAO) base oil. 
     
     
         8 . The lubricating oil composition according to  claim 1 , wherein the lubricating base oil (A) has a kinematic viscosity at 100° C. of 3 to 40 mm 2 /s. 
     
     
         9 . The lubricating oil composition according to  claim 1 , which is used for a transmission. 
     
     
         10 . The lubricating oil composition according to  claim 1 , which is used for a differential gear. 
     
     
         11 . The lubricating oil composition according to  claim 2 , wherein the phosphorus-based extreme pressure agent (C) is at least one selected from phosphate esters, acid phosphate esters, phosphite esters, acid phosphite esters, thiophosphate esters, acid thiophosphate esters, thiophosphite esters, acid thiophosphite esters, amine salts of acid phosphate esters, amine salts of acid phosphite esters, amine salts of acid thiophosphate esters, and amine salts of acid thiophosphite esters. 
     
     
         12 . The lubricating oil composition according to  claim 11 , wherein the phosphorus-based extreme pressure agent (C) is at least one selected from amine salts of acid phosphate esters, amine salts of acid phosphite esters, amine salts of acid thiophosphate esters, and amine salts of acid thiophosphite esters. 
     
     
         13 . The lubricating oil composition according to  claim 2 , which has a kinematic viscosity at 100° C. of 3 to 40 mm 2 /s. 
     
     
         14 . The lubricating oil composition according to  claim 3 , which has a kinematic viscosity at 100° C. of 3 to 40 mm 2 /s. 
     
     
         15 . The lubricating oil composition according to  claim 4 , which has a kinematic viscosity at 100° C. of 3 to 40 mm 2 /s. 
     
     
         16 . The lubricating oil composition according to  claim 11 , which has a kinematic viscosity at 100° C. of 3 to 40 mm 2 /s. 
     
     
         17 . The lubricating oil composition according to  claim 12 , which has a kinematic viscosity at 100° C. of 3 to 40 mm 2 /s. 
     
     
         18 . The lubricating oil composition according to  claim 2 , wherein the lubricating base oil (A) is at least partially a GTL (Gas to Liquid)-derived based oil. 
     
     
         19 . The lubricating oil composition according to  claim 3 , wherein the lubricating base oil (A) is at least partially a GTL (Gas to Liquid)-derived based oil. 
     
     
         20 . The lubricating oil composition according to  claim 4 , wherein the lubricating base oil (A) is at least partially a GTL (Gas to Liquid)-derived based oil.