Friction and wear reducing agent for lubricating oil and lubricating oil composition containing same

Abstract

The purpose of the present invention is to provide an additive for lubricating oil, which does not substantially contain metal elements or the like and is safe but which demonstrates extreme pressure performance equivalent to conventional extreme pressure agents each containing a metal element when used in lubricating applications. In order to achieve the above-mentioned purpose, the present invention provides a friction and wear reducing agent for lubricating oil consisting of a copolymer (A) comprising an alkyl acrylate (a) represented by the following general formula (1) and a hydroxyalkyl acrylate (b) represented by the following general formula (2) as essential constituent monomers, wherein the constitutive ratio of (a) to (b) is 50/50 to 90/10 (molar ratio) and the weight average molecular weight thereof is 2,000 to less than 40,000. (in the above formula, R′ represents an alkyl group having 10 to 18 carbon atoms) (in the above formula, R 2 represents an alkylene group having 2 to 4 carbon atoms)

1 . A friction and wear reducing agent for lubricating oil consisting of a copolymer (A) comprising an alkyl acrylate (a) represented by the following general formula (1) and a hydroxyalkyl acrylate (b) represented by the following general formula (2) as essential constituent monomers, wherein the constitutive ratio of (a) to (b) is 50/50 to 90/10 (molar ratio) and the weight average molecular weight thereof is 2,000 to less than 40,000. 
       
         
           
           
               
               
           
         
         (in the above formula, R 1  represents an alkyl group having 10 to 18 carbon atoms) 
       
       
         
           
           
               
               
           
         
         (in the above formula, R 2  represents an alkylene group having 2 to 4 carbon atoms) 
       
     
     
         2 . The friction and wear reducing agent for lubricating oil according to  claim 1 , wherein the copolymer (A) is a copolymer consisting of an alkyl acrylate (a) and a hydroxyalkyl acrylate (b). 
     
     
         3 . The friction and wear reducing agent for lubricating oil according to  claim 1 , wherein R 1  of the alkyl acrylate (a) is an alkyl group having 10 to 14 carbon atoms. 
     
     
         4 . A lubricating oil composition comprising a base oil and the friction and wear reducing agent for lubricating oil according to  claim 1 , wherein the friction and wear reducing agent for lubricating oil is contained in an amount of 0.1 to 50% by weight with respect to the total amount of the lubricating oil composition. 
     
     
         5 . A lubricating oil composition comprising a base oil and the friction and wear reducing agent for lubricating oil according to  claim 3 , wherein the friction and wear reducing agent for lubricating oil is contained in an amount of 0.1 to 50% by weight with respect to the total amount of the lubricating oil composition. 
     
     
         6 . The friction and wear reducing agent for lubricating oil according to  claim 2 , wherein R 1  of the alkyl acrylate (a) is an alkyl group having 10 to 14 carbon atoms. 
     
     
         7 . A lubricating oil composition comprising a base oil and the friction and wear reducing agent for lubricating oil according to  claim 2 , wherein the friction and wear reducing agent for lubricating oil is contained in an amount of 0.1 to 50% by weight with respect to the total amount of the lubricating oil composition. 
     
     
         8 . A lubricating oil composition comprising a base oil and the friction and wear reducing agent for lubricating oil according to  claim 6 , wherein the friction and wear reducing agent for lubricating oil is contained in an amount of 0.1 to 50% by weight with respect to the total amount of the lubricating oil composition.