Synthesis and application of T310A thiophosphate antiwear additive

Dihydrocarbyl phosphate, sulfur, and aliphatic amine were catalytically synthesized for preparing T310A thiophosphate, a new anti-wear additive, possessing superior EP anti-wear and friction reducing performance, good thermal oxidation stability, and hydrolytic stability. Compared with T310 boronating thiophosphate, multifunctional phosphorus-containing additive T310A exhibited better EP anti-wear property, and adaptability for various base oils, such as common base oil, hydrogenated base oil, and synthetic base oil. A gear oil additive package (T4208) was formulated using T310A thiophosphate and other additives. The 80W/90 heavy-duty automobile gear oil with 4.2% of the additive package in hydrogenated base oil reached and exceeded the standard API GL-5.