In the past, sulfurized sperm oil has been used as an additive such as for friction modifiers in many lubricant formulations such as in gear oils, worm and spur gears, automatic transmission fluids, way lubricants, Permawick lubes for sintered bronze or sintered babbit bearings, and as a metal-working oil additive. Sperm oil has now become restricted and the present invention is directed to a replacement for sulfurized sperm oil. Sulfurized olefins alone do not have the lubricity necessary for many applications as is indicated by their high stick/slip ratios. Sulfurized naturally occurring triglycerides such as lard oil do not have adequate solubility in paraffinic base oils. It has now been found that by sulfurizing a blend of a triglyceride and an ethylenically unsaturated hydrocarbon and preferably an olefin together a material is obtained which has good lubricity and is soluble in paraffinic base lube stocks. When the olefin and triglyceride are sulfurized separately and then blended together, a different product is obtained and the blend of the separately sulfurized oils comes out of solution in paraffinic base lubes. When one or the other of the triglyceride and olefin are separately sulfurized and then blended with the unsulfurized component and re-exposed to sulfurization conditions, a different product is also obtained.
USPTO Backgrounds
USPTO Backgrounds