Boron in lubricants:
To produce a lubricant, you must blend additives, viscosity modifiers, ashless dispersants, detergents, inhibitors, anti-wear agents, friction modifiers, and flow enhancers into a base oil stock.
Because there are several inputs, you must look for a synergistic additive such as borates to enhance a formulation without subverting functionality.
Extreme-pressure additives
Alkali borate microspheres are very stable in their dispersion, making them highly useful in the production of extreme-pressure additives. Inorganic borate spheres interact with metal surfaces to form a highly resistant film, providing load-carrying capacity and wear protection. Additives containing nitrogen and boron—prepared by reacting polyamines, carboxylate esters, or amine/ester mixtures with boric acid or boric oxide at elevated temperatures—have also been proposed for lubricating oil compositions.