Survey on the development of inorganic borates as oil additives

The molecular structure, the preparation and the antiwear mechanism of borates additives were described. Inorganic borate additives are of no hazard, no smell, good antiwear ability and high load-carrying capacity. With the combination of inorganic borate additive with succinimide dispersant, the antiwear ability can be improved; whereas with sulfonate dispersant, the antiwear ability decreases. The tests show that an inorganic borate protective surface film is formed on the rubbing surface to have antiwear and extreme-pressure properties. It is also pointed out that more work should be done to study the tribological properties of the blends of inorganic borates and S, P and Cl containing additives, and to improve the stability of borate oil.