Lubricating oil composition for sliding glide surface

Abstract

A lubricating oil composition for a sliding guide surface, which exhibits excellent low friction properties and extreme pressure properties so as to enable high precision machining in a machine tool, is disclosed.

1 . A lubricating oil composition for a sliding guide surface comprising:
 a base oil that is a base oil of group Ito group IV in the API base oil categories or a mixture thereof,   a phosphonate represented by formula 1   
       
         
           
           
               
               
           
         
       
       wherein R 1  denotes a saturated or unsaturated alkyl group having 12-22 carbon atoms, and R 2  denotes a saturated or unsaturated alkyl group having 1-18 carbon atoms, and
 a fatty acid represented by formula 2
   R 3 COOH   (2)
 
 
 
       wherein R3 denotes a saturated or unsaturated alkyl group having 7-17 carbon atoms. 
     
     
         2 . A lubricating oil composition for a sliding guide surface according to  claim 1 , wherein the phosphonate is present in a quantity of not less than 0.2 mass % but less than 2 mass % relative to the overall quantity of the lubricating oil composition, and the fatty acid is is present in a quantity of not less than 0.03 mass % but less than 1 mass % relative to the overall quantity of the lubricating oil composition. 
     
     
         3 . A lubricating oil composition for a sliding guide surface according to  claim 1 , wherein the base oil is a base oil belonging to group III and/or a base oil belonging to group IV in the API base oil categories. 
     
     
         4 . A lubricating oil composition for a sliding guide surface according to  claim 1 , which further comprises an anti-wear agent and/or a metal deactivator. 
     
     
         5 . (canceled) 
     
     
         6 . A lubricating oil composition for a sliding guide surface according to  claim 1 , wherein the fatty acid is present in a quantity of not less than 0.1 mass % and not more than 0.7 mass % relative to the overall quantity of the lubricating oil composition. 
     
     
         7 . A lubricating oil composition for a sliding guide surface according to  claim 1 , wherein the phosphonate comprises one or more phosphonates selected from the group consisting of dimethyldodecyl phosphonate, dimethyltridecyl phosphonate, dimethyltetradecyl phosphonate, dimethylpentadecyl phosphonate, dimethylhexadecyl phosphonate, dimethylheptadecyl phosphonate, dimethyloctadecyl phosphonate, dimethylnonadecyl phosphonate, dimethyleicosyl phosphonate, tridodecyl phosphonate, tritridecyl phosphonate, tritetradecyl phosphonate, tripentadecyl phosphonate, trihexadecyl phosphonate, triheptadecyl phosphonate, trioctadecyl phosphonate (tristearyl phosphite: tautomer) and trioleyl phosphonate. 
     
     
         8 . A lubricating oil composition for a sliding guide surface according to  claim 1 , wherein the fatty acid comprises one or more more fatty acids selected from the group consisting of caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid and linolenic acid. 
     
     
         9 . A method comprising:
 applying a lubricating oil composition to a sliding guide surface of a machine tool, wherein the lubricating oil composition comprises:   a base oil that is a base oil of group Ito group IV in the API base oil categories or a mixture thereof,   a phosphonate represented by formula 1   
       
         
           
           
               
               
           
         
       
       wherein R 1  denotes a saturated or unsaturated alkyl group having 12-22 carbon atoms, and R2 denotes a saturated or unsaturated alkyl group having 1-18 carbon atoms, and
 a fatty acid represented by formula 2
   R 3 COOH   (2)
 
 
 wherein R3 denotes a saturated or unsaturated alkyl group having 7-17 carbon atoms. 
 
     
     
         10 . A method according to  claim 9 , wherein the phosphonate in the lubricating oil composition is present in a quantity of not less than 0.2 mass % but less than 2 mass % relative to the overall quantity of the lubricating oil composition, and the fatty acid is is present in a quantity of not less than 0.03 mass % but less than 1 mass % relative to the overall quantity of the lubricating oil composition. 
     
     
         11 . A method according to  claim 9 , wherein the base oil is a base oil belonging to group III and/or a base oil belonging to group IV in the API base oil categories. 
     
     
         12 . A method according to  claim 9 , wherein the lubricating oil composition further comprises an anti-wear agent and/or a metal deactivator. 
     
     
         13 . A method according to  claim 9 , wherein the fatty acid in the lubricating oil composition is present in a quantity of not less than 0.1 mass % and not more than 0.7 mass % relative to the overall quantity of the lubricating oil composition. 
     
     
         14 . A method according to  claim 9 , wherein the phosphonate in the lubricating oil composition comprises one or more phosphonates selected from the group consisting of dimethyldodecyl phosphonate, dimethyltridecyl phosphonate, dimethyltetradecyl phosphonate, dimethylpentadecyl phosphonate, dimethylhexadecyl phosphonate, dimethylheptadecyl phosphonate, dimethyloctadecyl phosphonate, dimethylnonadecyl phosphonate, dimethyleicosyl phosphonate, tridodecyl phosphonate, tritridecyl phosphonate, tritetradecyl phosphonate, tripentadecyl phosphonate, trihexadecyl phosphonate, triheptadecyl phosphonate, trioctadecyl phosphonate (tristearyl phosphite: tautomer) and trioleyl phosphonate. 
     
     
         15 . A method according to  claim 9 , wherein the fatty acid in the lubricating oil composition comprises one or more more fatty acids selected from the group consisting of caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid and linolenic acid.