Ionic liquids containing symmetric quaternary phosphonium cations and phosphorus-containing anions, and their use as lubricant additives

摘要

An ionic liquid composition having the following generic structural formula:; wherein R¹, R², R³, and R⁴ are equivalent and selected from hydrocarbon groups containing at least three carbon atoms, and X⁻ is a phosphorus-containing anion, particularly an organophosphate, organophosphonate, or organophosphinate anion, or a thio-substituted analog thereof containing hydrocarbon groups with at least three carbon atoms. Also described are lubricant compositions comprising the above ionic liquid and a base oil, wherein the ionic liquid is dissolved in the base oil. Further described are methods for applying the ionic liquid or lubricant composition onto a mechanical device for which lubrication is beneficial, with resulting improvement in friction reduction, wear rate, and/or corrosion inhibition.