Patent attributes
The present invention relates to an improved process for preparing polyalkenylsuccinimides having a sediment level less than 0.1 vol % comprising the steps of:(a) preparing a polyalkenyl derivative of an unsaturated acidic reagent by(i) reacting a polyalkylene with an unsaturated acidic reagent in the absence of a strong acid until at least 25% of the polyalkylene is converted to a polyalkenyl derivative of an unsaturated acidic reagent;(ii) continuing the reaction with an excess of the unsaturated acidic reagent in the presence of a strong acid to convert at least some of the unreacted polyalkylene to additional polyalkenyl derivative of an unsaturated acidic reagent; and(iii) removing the unreacted unsaturated acidic reagent;(b) reacting the unfiltered product of step (a) with a polyamine having at least one basic nitrogen atom;(c) diluting the product of step (b); and(d) subsequently filtering the polyalkenylsuccinimide product.
