Process for preparation of improved lubricating compositions

Claim 1

A PROCESS FOR PRODUCING SUPERIOR LUBRICATING OIL ADDITIVES WHICH COMPRISES INTIMATELY ADMIXING A QUANTITY OF SULFONATING AGENT CONSISTING ESSENTIALLY OF LIQUID SO3 DISSOLVED IN AN INORANIC SOLVENT EQUIVALENT TO FROM 0.2 TO 1 PART BY WEIGHT OF 20 PERCENT FUMING SULFURIC ACID AND 1 PART BY WEIGHT OF A PROPANE-FRACTIONATED, SOLVENT-EXTRACTED AND DEWAXED INTERMEDIATE BASE BRIGHT STOCK OF ABOUT 200 TO 230 SUS AT 210*F. AND HAVING A VISCOSITY INDEX OF AT LEAST ABOUT 85, AT A TEMPERATURE OF ABOUT 50 TO ABOUT 200*F.; NEUTRALIZING THE RESULTING REACTION PRODUCT WITH AT LEAST THE MINUMUM REQUIRED FOR NEUTRALIZATION OF AN AQUEOUS SLURRY OF A BASIC ALKALINE EARTH METAL COMPOUND; HEATING THE MIXTURE IN LIQUID PHASE AT A TEMPERATURE IN THE RANGE OF ABOUT 360 TO 400*F. FOR ABOUT 10 MINUTES TO RENDER SAME NONCORROSIVE; VAPORIZING AND REMOVING WATER FROM SAID MIXTURE; AND REMOVING INORGANIC SOLIDS SO AS TO RECOVER A MIXTURE OF ALKALINE EARTH PETROLEUM SULFONATE AND PRODUCT OIL HAVING A SULFATED ASH CONTENT OF NOT MORE THAN 6 WEIGHT PERCENT.