Abstract: A borate ester represented by one of the following formulae:

Abstract: A borate ester represented by one of the following formulae: wherein each R1 is independently hydrocarbyl, a hydrocarbyloxy or a hydrocarbylthio group or both R1 on the same phosphorus atom taken together form a heterocyclic group; each X1 and X2 is independently an oxygen or sulfur; and each R2 is independently a hydrocarbylene group. These reaction products are useful as lubricant additives for oil-based and water-based functional fluids. These materials act as anti-wear, extreme pressure and friction modifying agents.

Abstract: A composition is disclosed which comprises:(A) a compound represented by the formula ##STR1## wherein Ar.sup.1 and Ar.sup.2 are independently mononuclear or polynuclear, substituted or unsubstituted aromatic groups; R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently hydrogen or hydrocarbyl groups of from 1 to about 25 carbon atoms; X is at least one divalent sulfur atom, sulfone group, sulfixide group, or a mixture thereof; and n is a number ranging from 1 to about 5; and(B) a compound represented by the formula ##STR2## wherein Ar.sup.3 and Ar.sup.4 are independently mononuclear or polynuclear, substituted or unsubstituted aromatic groups; and R.sup.5 is hydrogen, halogen, OH, NH.sub.2, SH, NO.sub.2 or a hydrocarbyl group of from 1 to about 50 carbon atoms. Concentrates, lubricants, functional fluids, fuels, aqueous compositions and emulsions comprising the foregoing compositions are also disclosed.