Lubricating oil composition for industrial machine, and lubricating method

Abstract

A lubricating oil composition for industrial machines containing a base oil (A) and a specific acylglycerol (B) and having excellent brake squeal preventing performance, and a lubrication method using the composition.

1 : A lubricating oil composition for industrial machines, the composition comprising:
 (A) a base oil (A); and   (B) an acylglycerol (B) represented by the following general formula (1):   
       
         
           
           
               
               
           
         
         wherein: 
         R 11 , R 12 , and R 13  each independently represent an acyl group represented by —C(═O)R 14 , or a hydrogen atom; 
         at least any of R 11 , R 12 , and R 13  is the acyl group; 
         R 14  represents a monovalent hydrocarbon group having 12 or more and 30 or less carbon atoms; and 
         when a plurality of the acyl groups is present, R 14 's in the acyl groups may be the same or different. 
       
     
     
         2 : The lubricating oil composition for industrial machines according to  claim 1 , wherein a content of the acylglycerol (B) based on the total amount of the composition is 0.01% by mass or more and 2.5% by mass or less. 
     
     
         3 : The lubricating oil composition for industrial machines according to  claim 1 , further comprising:
 (C) an amine compound (C) represented by the following general formula (2):   
       
         
           
           
               
               
           
         
         wherein: 
         R 21  represents a hydrogen atom, or a monovalent hydrocarbon group having 12 or more and 30 or less carbon atoms; 
         R 22  and R 23  each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 or more and 5 or less carbon atoms; and 
         at least one of R 21 , R 22 , and R 23  is a hydrocarbon group. 
       
     
     
         4 : The lubricating oil composition for industrial machines according to  claim 3 , wherein a content of the amine compound (C) based on the total amount of the composition is 0.01% by mass or more and 2.5% by mass or less. 
     
     
         5 : The lubricating oil composition for industrial machines according to  claim 1 , which has a total nitrogen atom content of 500 ppm by mass or more and 2,000 ppm by mass or less based on the total amount of the composition. 
     
     
         6 : The lubricating oil composition for industrial machines according to  claim 1 , wherein:
 the acylglycerol (B) is a monoacylglycerol represented by the general formula (1) where any one of R 11 , R 12 , and R 13  is an acyl group represented by —C(═O)R 14 ;   R 14  is an alkyl or alkenyl group having 12 or more and 30 or less carbon atoms; and   any two of the other R 11 , R 12 , and R 13  are hydrogen atoms.   
     
     
         7 : The lubricating oil composition for industrial machines according to  claim 3 , wherein:
 the amine compound (C) is an amine represented by the general formula (2) where R 21  is an alkyl or alkenyl group having 12 or more and 30 or less carbon atoms; and   R 22  and R 23  are hydrogen atoms.   
     
     
         8 : The lubricating oil composition for industrial machines according to  claim 1 , which has a kinematic viscosity at 40° C. of 30 mm 2 /s or more and 70 mm 2 /s or less. 
     
     
         9 : The lubricating oil composition for industrial machines according to  claim 1 , wherein the industrial machines are those equipped with a transmission, a hydraulically actuated part and a wet brake. 
     
     
         10 : The lubricating oil composition for industrial machines according to  claim 1 , wherein the industrial machines are transporting machines. 
     
     
         11 : A lubrication method, comprising lubricating an industrial machine with the lubricating oil composition of  claim 1 . 
     
     
         12 : The lubrication method according to  claim 11 , wherein lubricating of the industrial machine includes lubricating at least one of a transmission, a hydraulically actuated part and a wet brake contained in the industrial machine.