Nanoparticle-containing lubricating oil compositions

Abstract

To provide a nanoparticle-containing lubricating oil composition which demonstrates a low friction coefficient and realizes a further fuel economy. A nanoparticle-containing lubricating oil composition comprising a base oil, an additive having hydroxyl group, and nanoparticle. A nanoparticle-containing lubricating oil composition comprising a base oil, an ashless friction modifier having hydroxyl group, and nanoparticle. A nanoparticle-containing lubricating oil composition comprising a base oil, an additive having hydroxyl group, and nanoparticle having a particle diameter of 1 to 100 nm. A nanoparticle-containing lubricating oil composition comprising a base oil, an ashless friction modifier having hydroxyl group, and nanoparticle having a particle diameter of 1 to 100 nm.

1 . A nanoparticle-containing lubricating oil composition comprising a lubricating oil including an oxygen-containing base oil or an oxygen-containing base oil containing an oxygen-containing additive, characterized in that the lubricating oil contains nanoparticle. 
   
   
       2 . A nanoparticle-containing lubricating oil composition comprising a base oil, an oxygen-containing additive, and nanoparticle. 
   
   
       3 . A nanoparticle-containing lubricating oil composition as claimed in  claim 1 , wherein all or a part of the oxygen-containing additive is an ashless friction modifier. 
   
   
       4 . A nanoparticle-containing lubricating oil composition as claimed in  claim 1 , wherein the nanoparticle has a particle diameter ranging from 1 to 100 nm. 
   
   
       5 . A nanoparticle-containing lubricating oil composition as claimed in  claim 1 , wherein the nanoparticle is contained in an amount ranging from 0.05 to 3%. 
   
   
       6 . A nanoparticle-containing lubricating oil composition as claimed in  claim 1 , wherein the nanoparticle is contained in an amount ranging from 0.1 to 0.6 part by weight based on 100 parts by weight of total of the base oil and the additive. 
   
   
       7 . A nanoparticle-containing lubricating oil composition as claimed in  claim 6 , wherein the nanoparticle is contained in an amount ranging from 0.3 to 0.5 part by weight based on 100 parts by weight of total of the base oil and the additive. 
   
   
       8 . A nanoparticle-containing lubricating oil composition as claimed in  claim 1 , wherein all or a part of the nanoparticle is oxide or carbide. 
   
   
       9 . A nanoparticle-containing lubricating oil composition as claimed in  claim 8 , wherein all or a part of the oxide is alumina. 
   
   
       10 . A nanoparticle-containing lubricating oil composition as claimed in  claim 1 , wherein all or a part of the nanoparticle is a carbon material whose main component is carbon. 
   
   
       11 . A nanoparticle-containing lubricating oil composition as claimed in  claim 10 , wherein all or a part of the carbon material is soot. 
   
   
       12 . A nanoparticle-containing lubricating oil composition as claimed in  claim 10 , wherein all or a part of the carbon material is diamond-like carbon. 
   
   
       13 . A nanoparticle-containing lubricating oil composition as claimed in  claim 10 , wherein all or a part of the carbon material is diamond. 
   
   
       14 . A nanoparticle-containing lubricating oil composition as claimed in  claim 13 , wherein the nanoparticle formed of the diamond is of single crystal. 
   
   
       15 . A nanoparticle-containing lubricating oil composition as claimed in  claim 13 , wherein the nanoparticle formed of diamond has a particle diameter of not larger than 10 nm. 
   
   
       16 . A lubricating oil composition as claimed in  claim 1 , wherein a nonionic surface active agent is mixed in order to disperse the particle in the lubricating oil. 
   
   
       17 . A lubricating oil composition as claimed in  claim 16 , wherein the surface active agent is a mixture of an ether-based surface active agent and a phosphorus-based surface active agent. 
   
   
       18 . A lubricating oil composition as claimed in  claim 17 , wherein the surface active agent is a mixture of polyoxyethylenealkyl ether and polyoxyethylenealkyletherphosphate. 
   
   
       19 . A lubricating oil composition as claimed in  claim 18 , wherein the surface active agent includes polyoxyethylenealkyl ether in an amount ranging from 5 to 15%, and polyoxyethylenealkyletherphosphate in an amount ranging from 85 to 95%. 
   
   
       20 . A lubricating oil composition as claimed in  claim 17 , wherein the surface active agent is a mixture of polyoxyethylenedialkylphenyl ether and polyoxyethylenealkylphenylphosphate. 
   
   
       21 . A lubricating oil composition as claimed in  claim 20 , wherein the surface active agent includes polyoxyethylenealkylphenyl ether in an amount ranging from 10 to 15%, and polyoxyethylenealkyletherphosphate in an amount ranging from 85 to 90%. 
   
   
       22 . A lubricating oil composition as claimed in  claim 17 , wherein the surface active agent comprises a mixture of polyoxyethylenealkylphenyl ether and polyoxyethylenealkylphenyletherphosphate