Lubricating oil composition

Abstract

A lubricating oil composition contains (A) a base oil for a lubricating oil in a range of 5 mass % to 70 mass % based on a total amount of the composition, the base oil containing a sulfur content of 0.03 mass % or less and having a kinematic viscosity at 100 degrees C. in a range of 0.5 mm 2 /s to 1.5 mm 2 /s, and (B) a poly-alpha-olefin in a range of 15 mass % to 30 mass % based on the total amount of the composition, the poly-alpha-olefin having a kinematic viscosity at 100 degrees C. of 150 mm 2 /s or more.

1 . A lubricating oil composition comprising:
 (A) a base oil suitable as a lubricating oil, wherein the base oil
 is present in a range of 5 mass % to 70 mass % based on a total amount of the composition, 
 comprises a sulfur content of 0.03 mass % or less and 
 has a kinematic viscosity at 100 degrees C. in a range of 0.5 mm 2 /s to 1.5 mm 2 /s; and 
   (B) a poly-alpha-olefin (B), wherein the poly-alpha-olefin (B)
 is present in a range of 15 mass % to 30 mass % based on the total amount of the composition, and 
 has a kinematic viscosity at 100 degrees C. of 150 mm 2 /s or more. 
   
     
     
         2 . The lubricating oil composition according to  claim 1 , further comprising:
 (C) a silicone oil having a kinematic viscosity at 100 degrees C. in a range of 0.5 mm 2 /s to 4 mm 2 /s.   
     
     
         3 . The lubricating oil composition according to  claim 1 , further comprising:
 (D) a polymethacrylate (D) having a mass average molecular weight of 100000 or more.   
     
     
         4 . The lubricating oil composition according to  claim 1 , further comprising:
 (E) a poly-alpha-olefin (E) having a kinematic viscosity at 100 degrees C. in a range of 1.5 mm 2 /s to 2.5 mm 2 /s.   
     
     
         5 . The lubricating oil composition according to  claim 1 , further comprising:
 (F) a polymethacrylate (E) having a mass average molecular weight of 300000 or more and present in a range of 0.1 mass % to 5.0 mass % based on a total amount of the composition; and   (G) a poly-alpha-olefin (G) having a kinematic viscosity of 100 degrees C. in a range of 1.7 mm 2 /s to 2.1 mm 2 /s and present in a range of 0.1 mass % to 60 mass % based on the total amount of the composition,   wherein   a kinematic viscosity of the base oil (A) at 100 degrees C. is in a range of 0.7 mm 2 /s to 1.3 mm 2 /s, and   a kinematic viscosity of the poly-alpha-olefin (B) at 100 degrees C. is in a range of 150 mm 2 /s to 400 mm 2 /s.   
     
     
         6 . The lubricating oil composition according to  claim 1 , wherein the lubricating oil composition is suitable for a transmission. 
     
     
         7 . The lubricating oil composition according to  claim 2 , further comprising:
 (D) a polymethacrylate (D) having a mass average molecular weight of 100000 or more.   
     
     
         8 . The lubricating oil composition according to  claim 2 , further comprising:
 (E) a poly-alpha-olefin (E) having a kinematic viscosity at 100 degrees C. in a range of 1.5 mm 2 /s to 2.5 mm 2 /s.   
     
     
         9 . The lubricating oil composition according to  claim 3 , further comprising:
 (E) a poly-alpha-olefin (E) having a kinematic viscosity at 100 degrees C. in a range of 1.5 mm 2 /s to 2.5 mm 2 /s.   
     
     
         10 . The lubricating oil composition according to  claim 7 , further comprising:
 (E) a poly-alpha-olefin (E) having a kinematic viscosity at 100 degrees C. in a range of 1.5 mm 2 /s to 2.5 mm 2 /s.   
     
     
         11 . The lubricating oil composition according to  claim 5 , wherein the lubricating oil composition is suitable for a transmission.