Salts of thiophosphoric acids and use thereof in lubricants

摘要

Salts of the anion of di-, tri- or tetrathiophosphoric acid of the formula I in which Z1 and Z2 are each independently an oxygen or sulfur atom, and Ra and Rb are each independently an organic group having 1 to 20 carbon atoms, and a cation which comprises a heterocyclic ring system having one to three nitrogen atoms.