The development direction of metal working liquid is to have the advantages of non-toxicity, low odor, low oil mist, long life, low waste liquid treatment cost, and strong biodegradability. Synthetic ester series products with the above advantages are widely used in the formulation of metal working oil (liquid). Among them, the most advantageous isooctyl oleate and trihydroxymethyl propane oleate are playing an important role in the metal processing liquid, which can replace the traditional formula of vulcanized lard, refined lard and fatty acid and other materials, so as to further improve the lubrication, environmental protection, and service life of the metal processing liquid. Oleate commonly used mainly polyol esters oleate (trihydroxymethyl propane oleate) and monoester oleate (isooctyl oleate).

Trihydroxymethyl propane oleate is an ISO 46, biodegradable, hydroxy-stable, high flash point low pour point polyol ester, which is very suitable for use in very high environmental requirements, as a synthetic base oil and additives have a wide range of applications. Due to the existence of a number of ester groups than isooctyl oleate has better lubrication performance, high viscosity index, fire resistance, or biodegradation rate of more than 90%, which is easy to emulsifying type can be used as oil agent in cold rolling oil, steel tube drawing oil, cutting oil and other metal processing fluid is widely used, can also be used as textile leather additives intermediate and textile oil. In addition, the difficult emulsification type can be used as the base oil in the automobile gear oil or 46# and 68# anti-combustion hydraulic oil. The automobile gear oil based on trihydroxymethyl propane oleate is characterized by trihydroxymethyl propane oleate as the base oil, which is made by heating and mixing evenly. The lubricating oil has good extreme pressure wear resistance and high bearing capacity, which can meet the needs of gear lubrication for medium load vehicles. Fatty acid ester hydraulic oil (HFDU) used as fire resistance hydraulic oil is the development trend in recent years, because HFDU has excellent lubricity, high and low temperature stability, good fire resistance and biodegradability, and phosphate ester market competition because of its good biodegradability and non-toxic and win, and replace part of mineral oil in steel mill continuous casting line hydraulic system, Mechanical industry quenching hydraulic system, transmission machine hydraulic system. The easily emulsified trihydroxymethyl propane oleate is mainly used in the formula of metal processing oil to replace the vulcanized lard and tolic acid and other materials, which can improve the lubricity of oil products, extend the service life of processing oil, and reduce the physical injury of oil products to operators. A domestic metal processing liquid manufacturer, before with the downstream metal processing plant to provide a large number of vulcanized lard in the process oil, downstream factories complained that the smell of oil and gas is too large workers can not bear, then changed to trihydroxymethyl propane oleate formula, successfully solved the customer's problem, although the cost has been improved, but the service life of the oil products longer, Overall, there is no significant increase in usage costs.