Lubricant composition

Abstract

Provided is a lubricant composition that, even when the viscosity thereof has decreased, can suppress abrasion of bearings, etc. and scoring of gear tooth surfaces, etc. A lubricant composition that contains a lubricant base oil and a sulfur-based extreme pressure agent. The lubricant composition is characterized in that the amount of active sulfur in the extreme pressure agent is 5-30 mass % and in that the extreme pressure agent content of the lubricant composition is 5-15 mass % with respect to the mass of the whole composition.

1 . A lubricant composition comprising a lubricant base oil and a sulfur-based extreme pressure agent, wherein the amount of active sulfur in the extreme pressure agent is from 5% to 30% by weight, and the content of the extreme pressure agent in the composition is from 5% to 15% by weight based on the total weight of the lubricant composition. 
     
     
         2 . The lubricant composition according to  claim 1 , wherein the sulfur-based extreme pressure agent is a sulfurized olefin. 
     
     
         3 . The lubricant composition according to  claim 1 , wherein the lubricant composition has a kinetic viscosity at 100° C. of 5 to 15 mm 2 /s. 
     
     
         4 . The lubricant composition according to  claim 1 , wherein at least a part of the lubricant base oil is a Fischer-Tropsch-derived base oil. 
     
     
         5 . The lubricant composition according to  claim 1 , wherein at least a part of the lubricant base oil is a poly-α-olefin (PAO) base oil. 
     
     
         6 . The lubricant composition according to  claim 1 , wherein the lubricant base oil has a kinetic viscosity at 100° C. of 5 to 15 mm 2 /s. 
     
     
         7 . The lubricant composition according to  claim 1 , which is used for transmissions. 
     
     
         8 . The lubricant composition according to  claim 1 , which is used for differential gears. 
     
     
         9 . The lubricant composition according to  claim 2 , wherein the lubricant composition has a kinetic viscosity at 100° C. of 5 to 15 mm 2 /s. 
     
     
         10 . The lubricant composition according to  claim 2 , wherein at least a part of the lubricant base oil is a Fischer-Tropsch-derived base oil. 
     
     
         11 . The lubricant composition according to  claim 3 , wherein at least a part of the lubricant base oil is a Fischer-Tropsch-derived base oil. 
     
     
         12 . The lubricant composition according to  claim 2 , wherein at least a part of the lubricant base oil is a poly-α-olefin (PAO) base oil. 
     
     
         13 . The lubricant composition according to  claim 3 , wherein at least a part of the lubricant base oil is a poly-α-olefin (PAO) base oil. 
     
     
         14 . The lubricant composition according to  claim 4 , wherein at least a part of the lubricant base oil is a poly-α-olefin (PAO) base oil. 
     
     
         15 . The lubricant composition according to  claim 2 , wherein the lubricant base oil has a kinetic viscosity at 100° C. of 5 to 15 mm 2 /s. 
     
     
         16 . The lubricant composition according to  claim 3 , wherein the lubricant base oil has a kinetic viscosity at 100° C. of 5 to 15 mm 2 /s. 
     
     
         17 . The lubricant composition according to  claim 4 , wherein the lubricant base oil has a kinetic viscosity at 100° C. of 5 to 15 mm 2 /s. 
     
     
         18 . The lubricant composition according to  claim 5 , wherein the lubricant base oil has a kinetic viscosity at 100° C. of 5 to 15 mm 2 /s. 
     
     
         19 . The lubricant composition according to  claim 2 , which is used for transmissions. 
     
     
         20 . The lubricant composition according to  claim 2 , which is used for differential ge