Patent ID: 8603956

Claim:
A process for preparing a super overbased polyisobutene sulfonate and alkylbenzene sulfonate composition comprising (a) one or more super overbased polyisobutene sulfonates and (b) one or more super overbased alkylbenzene sulfonates, wherein the process comprises: (a) preparing a mixture of (i) one or more polyisobutene sulfonic acids, stabilized polyisobutene sulfonic acids, or mixtures thereof and (ii) one or more alkylbenzene sulfonic acids, stabilized alkybenzene sulfonic acids, or mixtures thereof; (b) reacting the mixture in (a) with a source of an alkaline earth metal, a C 1 to C 5 alkanol and carbon dioxide in the presence of a solvent; wherein the Total Base Number (TBN) of the sulfonate composition is greater than 400 and wherein the ratio of super overbased polyisobutene sulfonates to super overbased alkylbenzene sulfonates based on percentage of the total sulfonic acid in the super overbased polyisobutene sulfonate and alkylbenzene sulfonate composition which was contributed from the polyisobutene sulfonates and alkylbenzene sulfonates on a sulfonic acid basis is from about 1:9 to about 9:1 and further wherein the super overbased polyisobutene sulfonate and alkylbenzene sulfonate composition has a viscosity in the range from about 60 to about 500 cSt at 100° C.