Lubricant composition

Abstract

A lubricating oil composition comprising a lubricating base oil, and a mixture and/or a reaction product of (A) 0.01-0.5% by mass of at least one compound selected from among acid phosphates represented by formula (1) or formula (2), and (B) 0.01-2% by mass of an alkylamine represented by formula (3), based on the total weight of the composition, wherein the acid value due to component (A) is 0.1-1.0 mgKOH/g. [R 1 and R 2 represent hydrogen or straight-chain alkyl or straight-chain alkenyl groups, with at least one of R 1 and R 2 being a C6-12 straight-chain alkyl or straight-chain alkenyl group; R 3 and R 4 represent hydrogen straight-chain alkyl or straight-chain alkenyl groups, with at least one of R 3 and R 4 being a C13-18 straight-chain alkyl or straight-chain alkenyl group; and R 5 and R 6 represent hydrogen or C4-30 branched-chain alkyl groups, with at least one of R 5 and R 6 being a branched-chain alkyl group.]

1 . A lubricating oil composition comprising:
 a lubricating base oil, and   a mixture and/or a reaction product of (A) 0.01-0.5% by mass of at least one compound selected from among acid phosphates represented by the following formula (1) or (2), and (B) 0.01-2% by mass of an alkylamine represented by the following formula (3), based on the total weight of the composition,   the acid value due to component (A) being 0.1-1.0 mgKOH/g.   
       
         
           
           
               
               
           
         
       
       wherein R 1  and R 2  may be the same or different, and each represents hydrogen or a straight-chain alkyl or straight-chain alkenyl group, and at least one of R 1  and R 2  is a C6-12 straight-chain alkyl or straight-chain alkenyl group;
 wherein R 3  and R 4  may be the same or different, and each represents hydrogen or a straight-chain alkyl or straight-chain alkenyl group, and at least one of R 3  and R 4  is a C13-18 straight-chain alkyl or straight-chain alkenyl group; and 
 wherein R 5  and R 6  may be the same or different, and each represents hydrogen or a C4-30 branched-chain alkyl group, and at least one of R 5  and R 6  is a branched-chain alkyl group. 
 
     
     
         2 . A lubricating oil composition according to  claim 1 , wherein the lubricating base oil is a lubricating base oil with a viscosity index of 105 or greater, a saturated hydrocarbon component of 70% by mass or greater and a sulfur content of not greater than 0.2% by mass. 
     
     
         3 . A lubricating oil composition according to  claim 1 , wherein the nitrogen content of the lubricating base oil is not greater than 10 ppm by mass and the flash point of the lubricating base oil is 250° C. or higher. 
     
     
         4 . A lubricating oil composition according to  claim 1 , further comprising (C) 0.01-5% by mass of a sulfur compound, based on the total weight of the composition. 
     
     
         5 . A lubricating oil composition according to  claim 1 , used in a machine tool.