PURPOSE: To provide a pollution-free lubrication oil composition for metal working such as cold forging, etc., capable of facilitating the plastic working of a metallic material such as steel only by applying to the surface of metal without necessitating the film-forming treatment of the metal, by adding a specific phosphoric or phosphorous acid ester to a mineral oil or a synthetic oil.
CONSTITUTION: The objective lubrication oil composition is prepared by mixing a mineral oil and/or a synthetic oil with a phosphoric or phosphorous acid ester of formula (R is H, alkyl or aryl; R' is alkyl, higher alkenyl or aryl; n is 1 or 2) having a nevtralization or acid valve of preferably ≥0.2KOHmg/g. The amount of the ester is preferably 0.5W5wt% of the oil composition in terms of phosphorus content.
KOMATSUZAKI SHIGEKI
ITOU TADASHI
