| abstract |
1. A composition for reducing the copper-lead bearing corrosion of a formulation that includes a major amount of an oil of lubrication viscosity and a minor amount of a corrosion-reducing additive comprising (A) a borated dispersant with a total base number of from 20 to 160 on an oil-free basis; (B) a metal salt of a phosphorus acid; and (C) a metal overbased composition comprising at least one carboxylate, phenate, or sulfonate wherein the metal is lithium, sodium, potassium, magnesium or calcium, and wherein the improvement comprises (D) a borate ester. The borated ester and borated dispersant provide from 20 to about 800 parts per million (ppm) mass of boron in the composition. |