New surfactants for soluble extreme pressure cutting oils

The use of nonionic and anionic 'surfactants is common in soluble cutting oils to facilitate spontaneous emulsification and to keep the formulation stable. Various additives are also introduced in order to achieve high pressure stability, better resistance to high shears, minimum corrosion and other related properties. Tailor-made surfactants into which specific functional groups are introduced into the hydrophobic chain are of special interest mainly if extreme pressure (EP) properties can be improved. Those surfactants will help to replace part of the additives and will reduce the cost of the formulation. Incorporation of halogens (chlorine, bromine) to the hydrophobic tail of ethoxylated nonylphenols; sorbitan esters of fatty acids, ethoxylated oleyl alcohols and polyglycerol esters has been carried out. The new surfactants have high specific gravities and therefore can minimize creaming of the emulsion and will improve the EP properties of the soluble cutting oils. Functionalization of the surfactants did not retained the emulsion stability, yet reduced the creaming and the cost of the formulation. It has been also shown that the lubrication properties e.g. the resistance to load and torque have been improved.