R3 is an alkyl group containing from 6 to 20 carbon atoms, and R4 is selected from an alkyl group containing 6 to 20 carbon atoms, an aralkyl group wherein alkyl contains 1 to 2 carbon atoms and heterocyclic radicals and X is a suitable anion such as halide, e.g., chloride, bromide and iodide or nitrate, methosulfate or acetate.