METAL FREE LUBRICANTS

摘要

Lubricant compositions especially useful as hydraulic fluids contain a metal-free anti-wear or load-carrying additive containing sulphur and/or phosphorus and an amino succinate ester as corrosion inhibitor. Such compositions are free from heavy metal and have improved environmental acceptability where heavy metals are to be avoided, e.g. in agriculture. The lubricant base stock may be a biodegradable natural oil.