Engine oil additive composition comprising nanodiamond and method for preparing same

Abstract

The present invention relates to an engine oil additive composition, whereby a hydrophobically surface-modified nanodiamond is capable of being stably dispersed in oil for a long time by being used together with a specific dispersant. According to the present invention, the nanodiamond is stably dispersed in the engine oil for a long time, thereby reducing friction and abrasion of the machine such as an engine and thus improving fuel efficiency.

1 . An engine oil additive composition, comprising:
 60˜99% by weight of a base oil;   0.001˜0.5% by weight of a nano-diamond the surface of which is modified into a hydrophobic state; and   a dispersion agent which is formed of 0.05˜10% by weight of oleylamine, 0.01˜5% by weight of polyalkenyl succinimide, and 0.5˜35% by weight of oleic acid, wherein the engine oil additive composition contains nano-diamonds.   
     
     
         2 . The composition of  claim 1 , wherein the nano-diamond the surface of which is modified into a hydrophobic state is prepared by:
 a process (first step) wherein the nano-diamonds are treated with one or more of acids selected from a group consisting of hydrochloric acid, nitric acid, sulfuric acid and hydrogen peroxide;   a process (second step) wherein the nano-diamonds acid-treated in the first step are reacted with one or more of acid chlorides selected from a group consisting of thionyl chloride, phosphorous trichloride, and phosphorous pentachloride; and   a process (third step) wherein the nano-diamonds obtained in the second step are reacted with alkyl amine having 16˜18 carbons.   
     
     
         3 . The composition of  claim 1 , wherein the polyalkenyl succinimide is polyisobutenyl succinimide. 
     
     
         4 . A method for preparing an engine oil additive composition, comprising:
 treating (first step) nano-diamonds with one or more of acids selected from a group consisting of hydrochloric acid, nitric acid, sulfuric acid and hydrogen peroxide;   reacting (second step) the nano-diamonds acid-treated in the first step with one or more of acid chlorides selected from a group consisting of thionyl chloride, phosphorous trichloride, and phosphorous pentachloride;   reacting (third step) the nano-diamonds obtained in the second step with alkyl amine having 16˜18 carbons, thus preparing nano-diamonds the surfaces of which are modified into a hydrophobic state;   obtaining (fourth step) a dispersed thing by mixing the nano-diamonds the surfaces of which are modified into a hydrophobic state, with oleylamine and dispersing with ultrasonic waves; and   inputting (fifth step) polyalkenyl succinimide, oleic acid, and a base oil into the dispersed thing obtained in the fourth step and dispersing with ultrasonic waves.