Lubricant composition

Abstract

A lubricating oil composition containing a base oil (A), a molybdenum-based friction modifier (B), and a benzotriazole-based compound (C). The molybdenum-based friction modifier (B) contains a compound (B1) represented by the following general formula (b1): R 1 -R 4 and X 1 -X 4 are as defined in the disclosure. A content of the benzotriazole-based compound (C) is 0.03 mass % or less based on a total amount of the lubricating oil composition, and a kinematic viscosity at 100° C. of the lubricating oil composition is 9.3 mm 2 /s or less.

1 . A lubricating oil composition comprising:
 a base oil (A);   a molybdenum-based friction modifier (B); and   a benzotriazole-based compound (C),   wherein the molybdenum-based friction modifier (B) contains a compound (B1) represented by the following general formula (b1):   
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , R 3 , and R 4  each independently represent a short-chain substituent group (α) which is an aliphatic hydrocarbon group having 4 to 12 carbon atoms or a long-chain substituent group (β) which is an aliphatic hydrocarbon group having 13 to 22 carbon atoms; a molar ratio [(α)/(β)] of the short-chain substituent group (α) to the long-chain substituent group (β) in all molecules of the compound (B1) is 0.10 to 0.50; and X 1 , X 2 , X 3 , and X 4  each independently represent an oxygen atom or a sulfur atom, 
         a content of the benzotriazole-based compound (C) is 0.03 mass % or less based on a total amount of the lubricating oil composition, and 
         a kinematic viscosity at 100° C. of the lubricating oil composition is 9.3 mm 2 /s or less. 
       
     
     
         2 . The lubricating oil composition according to  claim 1 , wherein the benzotriazole-based compound (C) contains a compound (C1) represented by the following general formula (c1): 
       
         
           
           
               
               
           
         
         wherein R c1  is an alkyl group having 1 to 4 carbon atoms; p is an integer of 0 to 4; when multiple R c1 's are present, the multiple R c1 's may be same as or different from each other; R c2  is a methylene group or an ethylene group; and R c3  and R c4  are each independently a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. 
       
     
     
         3 . The lubricating oil composition according to  claim 1 , wherein a content of the molybdenum-based friction modifier (B) is 0.30 mass % to 1.50 mass % based on the total amount of the lubricating oil composition. 
     
     
         4 . The lubricating oil composition according to  claim 1 , wherein a content ratio [(B)/(C)] of the molybdenum-based friction modifier (B) to the benzotriazole-based compound (C) is 20 to 120 in mass ratio. 
     
     
         5 . The lubricating oil composition according to  claim 1 , further comprising:
 one or more lubricating oil additives selected from the group consisting of a viscosity index improver, a pour point depressant, a metal-based detergent, an ashless dispersant, an antioxidant, an anti-wear agent, and an extreme pressure agent.   
     
     
         6 . The lubricating oil composition according to  claim 1 , wherein a content of a dissolution aid is less than 5 parts by mass with respect to 100 parts by mass of the molybdenum-based friction modifier (B). 
     
     
         7 . The lubricating oil composition according to  claim 1 , wherein a content of an ashless friction modifier is less than 10 parts by mass with respect to 100 parts by mass of the molybdenum-based friction modifier (B). 
     
     
         8 . The lubricating oil composition according to  claim 1 , which is used in an internal combustion engine. 
     
     
         9 . The lubricating oil composition according to  claim 1 , which is used in a gasoline engine. 
     
     
         10 . (canceled) 
     
     
         11 . A method for producing a lubricating oil composition, comprising:
 mixing a base oil (A), a molybdenum-based friction modifier (B), and a benzotriazole-based compound (C), wherein   the molybdenum-based friction modifier (B) contains a compound (B1) represented by the following general formula (b1):   
       
         
           
           
               
               
           
         
         wherein R 1 , R 2 , R 3 , and R 4  each independently represent a short-chain substituent group (α) which is an aliphatic hydrocarbon group having 4 to 12 carbon atoms or a long-chain substituent group (β) which is an aliphatic hydrocarbon group having 13 to 22 carbon atoms; a molar ratio [(α)/(β)] of the short-chain substituent group (α) to the long-chain substituent group (β) in all molecules of the compound (B1) is 0.10 to 0.50; and X 1 , X 2 , X 3 , and X 4  each independently represent an oxygen atom or a sulfur atom, 
         a content of the benzotriazole-based compound (C) is 0.03 mass % or less based on a total amount of the lubricating oil composition, and 
         a kinematic viscosity at 100° C. of the lubricating oil composition is 9.3 mm 2 /s or less. 
       
     
     
         12 . A method of using the lubricating oil composition according to  claim 1  in an internal combustion engine.