| abstract |
Phthalic acid, such as terephthalic acid, is made soluble in oils of lubricating viscosity by mixing it with at least one phosphorus compound. The resulting product is useful for reducing corrosion in transmission lubricants. The composition of the present invention comprises (a) phthalic acid or an anhydride, ester or salt thereof; (b) (i) an inorganic phosphorus acid or salt thereof; and (ii) an aliphatic phosphorus ester other than zinc dialkyldithiophosphate. At least one of: (c) a dispersant; and (d) an oil of lubricating viscosity. |