Manufacture of basic petroleum sulfonate salts using two-step neutralization in non-aqueous phase

Claim 1

IN THE PROCESS FOR PREPARING BASIC ALKALINE EARTH METAL SALTS OF PETROLEUM SULFONIC ACIDS DERIVED FROM THE TREATMENT OF SOLVENT REFINED, DEWAXED AND CLAY TREATED LUBRICATING OIL FRACTIONS HAVING VISCOSITIES OF ABOUT 200 SUS AT 100*F. AND A VISCOSITY INDEX OF ABOUT 85 WITH A SULFONATING AGENT COMPRISES SULFUR TRIOXIDE DISSOLVED IN SULFUR DIOXIDE UNDER CONDITIONS TO FORM A SULFONATED PETROLEUM LUBRICATING OIL MIXTURE FROM WHICH EXCESS SULFONATING AGENT HAS BEEN REMOVED, THE IMPROVEMENT COMPRISING REACTING SAID SULFONATED PETROLEUM LUBRICATING OIL MIXTURE WITH LESS THAN A STOICHIOMETRIC AMOUNT OF AN ALKALINE EARTH METAL SALT OF A WEAK INORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF CARBONATES, ACETATES, PHOSPHATES AND BORATES WHEREBY TO FORM AN ACID SALT OF SAID PETROLEUM SULFONIC ACIDS HAVING AN ACID NUMBER OF BETWEEN ABOUT 10 TO 20, SAID REACTION BEING CARRIED TO COMPLETION AT TEMPERATURE OF ABOUT 150*F. AND IN THE PRESENCE ABOUT 1.0 TO 5.0 WEIGHT PERCENT OF WATER BASED ON THE WEIGHT OF SAID SULFONATED PETROLEUM LUBRICATING OIL, SAID AMOUNT OF WATER BEING SUFFICIENT TO SUBSTANTIALLY SATURATE THE PETROLEUM SULFONIC ACID PHASE OF SAID MIXTURE, REACTING SAID PARTIALLY-NEUTRALIZED PETROLEUM SULFONIC ACIDS WITH A SUFFICIENT AMOUNT OF A PURIFIED CARBONATEFREE ALKALINE EARTH METAL BASE TO FORM THE BASIC METAL SALT OF SAID PARTIALLY-NEUTRALIZED PETROLEUM SULFONIC ACIDS, RAISING THE REACTION MIXTURE TO A TEMPERATURE OF ABOUT 300* TO 500*F. TO EVAPORATE THE WATER THEREFROM AND RECOVERING BASIC ALKALINE EARTH METAL PETROLEUM SULFONATES FROM SAID REACTION MIXTURE.