Patent ID: 8333945

Claim:
A method for reducing a friction coefficient adjacent a lubricated surface, comprising providing an amount of reaction product comprising metal-containing nanoparticles dispersed in a fully formulated lubricant composition containing a base oil of lubricating viscosity, and applying the lubricant composition containing the reaction product to a surface to be lubricated, wherein the nanoparticles in the reaction product are self-dispersing and the reaction product is made by an improved process of reacting an organo-cerium salt, a fatty acid, and an amine in a reaction mixture in the absence of solvent at a temperature ranging from about 150° to about 250° C., wherein the improvement comprises reacting the organo-cerium salt, a fatty acid, and an amine in a molar ratio ranging from about 1:1:1 to about 1:2:2 in the reaction mixture and under an atmosphere selected from the group consisting of air, oxygen, nitrogen, and argon which is delivered subsurface to the reaction mixture to provide the reaction product comprising from about 20 to about 40% by weight of the nanoparticles in a substantially organic medium.