Patent ID: 7163912

Claim:
A lubricating oil composition comprising a lubricating oil and as a metal protectant, an additive selected from the group consisting of (a) a shelf stable haze free liquid of an overbased amorphous alkaline earth metal carbonate of a fatty acid and (b) a powdered overbased amorphous alkaline earth metal carbonate of a fatty acid isolated from said liquid, said liquid or powdered additive prepared according to the process of (i) reacting an alkaline earth metal base and a fatty acid with an equivalent ratio of metal base to fatty acid being greater than 1:1 in the presence of liquid hydrocarbon, (ii) carbonating the mixture to produce amorphous alkaline earth metal carbonate, (iii) adding during carbonation a dispersion of alkaline earth meta base, a liquid hydrocarbon and an aliphatic alcohol having at least 8 carbon atoms in relative amounts at a controlled rate of alkaline earth metal base addition to produce a stable haze free liquid reaction product, and (iv) removing water from the reaction product to obtain said liquid additive or powdered additive.