Biodegradable lubricating oil composition having flame retardancy

Abstract

The present invention provides a lubricating oil composition exhibiting more excellent flame retardancy and biodegradability. The biodegradable lubricating oil composition of the invention has flame retardancy and contains (1) a base oil containing a plant-derived oil in an amount of 60 mass % or more, and a polyol ester in an amount of 40 mass % or less, and (2) a polymethacrylate having a mass average molecular weight of 20,000 to 300,000 in an amount of 0.1 to 5 mass %.

1 . A biodegradable lubricating oil composition comprising:
 (A) a base oil comprising (a) a plant-derived oil in an amount of 60 mass % or more, and (b) a polyol ester in an amount of 40 mass % or less; and   (B) a polymethacrylate having a mass average molecular weight of 20,000 to 300,000 in an amount of 0.1 to 5 mass %.   
     
     
         2 . The biodegradable lubricating oil composition according to  claim 1 , wherein the plant-derived oil (a) is rapeseed oil having an oleic acid content of 60 mass % or more. 
     
     
         3 . The biodegradable lubricating oil composition according to  claim 1 , wherein the polyol ester (b) is a polyol partial ester having a hydroxyl value of 30 mg KOH/g or more and a flash point of 300° C. or higher. 
     
     
         4 . The biodegradable lubricating oil composition according to  claim 1 , which exhibits a kinematic viscosity at 40° C. of 120 mm 2 /s or less. 
     
     
         5 . The biodegradable lubricating oil composition according to  claim 1 , which is suitable as a hydraulic oil, a door closer oil, or a sliding surface oil. 
     
     
         6 . A hydraulic oil, comprising the biodegradable lubricating oil composition according to  claim 1 . 
     
     
         7 . A door closer oil comprising the biodegradable lubricating oil composition of  claim 1 . 
     
     
         8 . The biodegradable lubricating oil composition according to  claim 2 , wherein the polyol ester (b) is a polyol partial ester having a hydroxyl value of 30 mg KOH/g or more and a flash point of 300° C. or higher. 
     
     
         9 . The biodegradable lubricating oil composition according to  claim 2 , which exhibits a kinematic viscosity at 40° C. of 120 mm 2 /s or less. 
     
     
         10 . The biodegradable lubricating oil composition according to  claim 2 , which is suitable as a hydraulic oil, a door closer oil, or a sliding surface oil. 
     
     
         11 . A hydraulic oil, comprising the biodegradable lubricating oil composition according to  claim 2 . 
     
     
         12 . A door closer oil, comprising the biodegradable lubricating oil composition of  claim 2 .