Trithiane and phosphorus and/or thiophosphorus acid derivatives are described which are useful as extreme pressure compositions. The process comprises a reaction product obtained by reacting (A) an aldehyde of the structure IMAGE wherein R is a hydrocarbyl group containing from 1 to about 18 carbon atoms with (B) a phosphorus acid of the structure IMAGE (I) wherein R2 and R3 are each independently a hydrocarbyl group containing from 1 to about 30 carbon atoms, X1 and X2 are each independently oxygen or sulfur and n is independently zero or one in the presence of a lubricating base oil. A neutralizing agent, component (C), may be reacted with the phosphorus acid and/or thiophosphorus acid intermediate formed by the reaction of components (A) and (B).
展开▼
