Process for the preparation of overbased, molybdenum-alkaline earth

Abstract

The process comprises in sequence the following steps: (a) introducing into a reaction zone a sulfonic acid comprising a neutral ammonium sulfonate; (b) adding to and mixing with said sulfonic acid a substantially inert diluent, an alkaline earth metal compound, water, and an alkanol to form a hydration mixture; (c) heating said hydration mixture at an elevated temperature to hydrate said alkaline earth metal compound; (d) adding a molybdenum-containing compound to said reaction zone at a time during the period beginning after the introduction of said sulfonic acid and extending through said refluxing of said hydration mixture; and (e) adding an acidic material to said reaction zone at a temperature within the range of about 26.7.degree. C. (80.degree. F.) to about 68.5.degree. C. (155.degree. F.) to form a molybdenum-alkaline earth metal sulfonate dispersion. In an embodiment of the process, the process is characterized further by stripping the alkanol from the reaction zone prior to adding the acidic material. A polybutene succinic anhydride can be added to the reaction zone during the process as a process aid. Preferably, it is added prior to the addition of the molybdenum-containing compound.