| abstract |
(57) Summary: Composition The copper corrosiveness of a composition consisting of a large amount of a base oil, at least 50% by volume of which is a mineral oil having an inherent sulfur content of at least 0.2% by weight, is Of at least one oil-soluble neutral hydrocarbyl phosphite, most preferably triphenyl phosphite, is added. The addition of phosphite, in Cincinnati Milacron Thermal Stability Test Method "A", will also give copper of 5 or less if the composition fails this test without the addition of phosphite. A composition is obtained that exhibits a bar rating. The unpredictability of the present invention is demonstrated by the fact that not all high sulfur oils respond to this treatment and no explanation for the variety of results is presently known. |