Patent ID: 8648020

Claim:
A process for preparing a stable, free flowing overbased magnesium oxide dispersion with a magnesium content of 25 to 35% by weight based on the total weight of the dispersion, prepared by heating a reaction mixture comprising 2-15% of an alkylbenzene sulfonic acid dispersant having a MW of 300 or higher, 10-40% of MgO, 10%-20% of water, 1-10% of a C 1-5 carboxylic acid, 0-20% of a hydrocarbon carrier having a boiling point of 280° C. or higher selected from mineral oils, alkylated benzenes, oligomers or polymers of alpha olefins, polycyclic aromatics, alkylated derivatives of polycyclic aromatics and waxes, 30-80% of an alkylated aromatic organic solvent with a boiling point range from about 100° C. to about 250° C. selected from alkylated aromatic hydrocarbons, to an elevated temperature of 280-360° C. in a sealed reactor at, pressures of up to about 350 psig at which elevated temperature all water is removed wherein no acidic gas is passed through the mixture of MgO, dispersant, C 1-5 carboxylic acid , water, and alkylated aromatic organic solvent.