Ashless type engine oil composition

Abstract

Disclosed is an ashless-type engine oil composition. The engine oil composition particularly includes glyceryl monooleate, molybdenum dithiocarbamate and a dihydrocarbyl dithiophosphate metal salt together as a friction modifier. Accordingly, the engine oil composition of the present invention provides advantages of protecting a filter equipped in an exhaust gas after-treatment device and improving gas mileage and engine durability by maintaining sulfated ash in an amount of 0.8 wt % or less based on total weight of the engine oil composition.

What is claimed is: 
     
         1 . An ashless-type engine oil composition comprising:
 a base oil;   an ashless dispersant;   a metal purifier;   a friction modifier; and   common engine oil additives,   wherein the friction modifier includes glyceryl monooleate, molybdenum dithiocarbamate and a dihydrocarbyl dithiophosphate metal salt; and   a sulfated ash content in the engine oil composition is in an amount of about 0.8 wt % or less by weight, based on total weight of the engine oil composition.   
     
     
         2 . The ashless-type engine oil composition of  claim 1 , wherein the friction modifier includes the glyceryl monooleate in an amount of about 0.8 to 1.5 wt %, the molybdenum dithiocarbamate in an amount of about 0.4 to 1 wt % and the dihydrocarbyl dithiophosphate metal salt in an amount of about 1 to 2 wt %, based on total weight of the engine oil composition. 
     
     
         3 . The ashless-type engine oil composition of  claim 1 , wherein the dihydrocarbyl dithiophosphate metal salt is zinc di(alkyl having 8 to 20 carbon atoms)dithiophosphate. 
     
     
         4 . The ashless-type engine oil composition of  claim 1 , comprising:
 the base oil in an amount of about 80 to 92 wt %;   the ashless dispersant in an amount of about 3 to 8 wt %;   the alkali earth metal salicylate metal purifier in an amount of about 3 to 6 wt %;   the glyceryl monooleate in an amount of about 0.8 to 1.5 wt %;   the molybdenum dithiocarbamate in an amount of about 0.4 to 1 wt %; and   the dihydrocarbyl dithiophosphate metal salt in an amount of about 1 to 2 wt %, based on total weight of the engine oil composition.   
     
     
         5 . The ashless-type engine oil composition of  claim 4 , wherein the ashless dispersant is obtained by reacting polyalkylene polyamine and alkenylsuccinic anhydride. 
     
     
         6 . The ashless-type engine oil composition of  claim 1 , wherein kinematic viscosity of the oil composition at a temperature of about 100° C. is in a range of about 5 to 15 cSt. 
     
     
         7 . The ashless-type engine oil composition of  claim 1 , wherein phosphorous content is maintained in an amount of about 0.09 wt % or less, and sulfur content is maintained in an amount of about 0.3 wt % or less, based on total weight of the engine oil composition.