Method of processing lubricating oil

Claim 2

A PROCESS FOR THE TREATMENT OF A LUBRICATING OIL STOCK TO ENHANCE THE QUALITY THEREOF WHICH CONSISTS ESSENTIALLY OF SUBJECTING A PARAFFIN BASE RESIDUAL LUBRICATING OIL FRACTION TO REFINING TREATMENT INCLUDING SOLVENT DEASPHALTING, SOLVENT REFINING AND SOLVENT DEWAXING AND THEREAFTER CONTACTING THE RESULTING TREATED OIL WITH ADDED HYDROGEN IN THE PRESENCE OF A MILD HYDROGENATION CATALYST UNDER CONDITIONS FROM ABOUT 400*F. TO ABOUT 650* F. A PRESSURE WITHIN THE RANGE OF FROM ABOUT 500 TO ABOUT 1000 P.S.I.G., AND A SPACE VELOCITY OF FROM ABOUT 0.23 TO 2.0 TO EFFECT REACTIONS CONVERTING SAID TREATED OIL INTO A PRODUCT OIL HAVING IMPROVED STABILITY TO THIN-FILM OXIDATION AT HIGH TEMPERATURES.

Claim 3

AN AIRCRAFT ENGINE LUBRICATING OIL HAVING IMPROVED STABILITY TO THIN FILM OXIDATION AT HIGH TEMPERATURES, SAID OIL HAVING AN API GRAVITY WITHIN THE RANGE OF FROM ABOUT 27*F TO ABOUT 29*, A VISCOSITY INDEX WITHIN THE RANGE OF FROM ABOUT 95 TO ABOUT 98.5, A VISCOSITY WITHIN THE RANGE OF FROM ABOUT 109 TO ABOUT 26 SAYBOLT UNIVERSAL SECONDS AT 210*, A COLOR (TAG ROBINSON SCALE) WITHIN THE RANGE OF FROM ABOUT 3.5 TO ABOUT 6, A POUR POINT WITHIN THE RANGE OF FROM ABOUT 5*F. TO ABOUT 10*F., A CARBON RESIDUE WITHIN THE RANGE OF FROM ABOUT 0.33 TO ABOUT 0.54% BY WEIGHT, A SULFUR (BOMB) CONTENT WITHIN THE RANGE OF FROM ABOUT 0.0,% TO ABOUT 0.23% BY WEIGHT, AND A NEUTRALIZATION NUMBER WITHIN THE RANGE OF FROM ABOUT 0.03 TO ABOUT 0.09, SAID OIL BEING THE PRODUCT OBTAINED BY IN SEQUENCE SUBJECTING A PARAFFIN BASE RESIDUAL LUBRICATING OIL FRACTION TO SOLVENT DEASPHALTING, SOLVENT REFINING, AND SOLVENT DEWAXING AND THEREAFTER HYDROGENATING THE RESULTING TREATED OIL FRACTION WITH ADDED HYDROGEN AND IN THE PRESENCE OF A HYDROGENATION CATALYST SELECTED FROM THE GROUP CONSISTING OF MOLYBDENUM SULFIDE AND COBALT OXIDE-MOLYBDENUM OXIDE AT A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 417* TO ABOUT 606*F., A PRESSURE WITHIN THE RANGE OF FROM ABOUT 500 TO ABOUT 1000 P.S.I.G., A SPACE VELOCITY WITHIN THE RANGE OF FROM ABOUT 0.23 TO ABOUT 1.7 AND A HYDROGEN RECYCLE RATE OF FROM ABOUT 3100 TO ABOUT 10,000 STANDARD CUBIC FEET OF HYDROGEN PER BARREL OF OIL.

Claim 4

AN AIRCRAFT ENGINE LUBRICATING OIL HAVING IMPROVED STABILITY TO THIN FILM OXIDATION AT HIGH TEMPERATURES, SAID OIL HAVING AN API GRAVITY WITHIN THE RANGE OF FROM ABOUT 27*F TO ABOUT 29*, A VISCOSITY INDEX WITHIN THE RANGE OF FROM ABOUT 95 TO ABOUT 98.5, A VISCOSITY WITHIN THE RANGE OF FROM ABOUT 109 TO ABOUT 26 SAYBOLT UNIVERSAL SECONDS AT 210*, A COLOR (TAG ROBINSON SCALE) WITHIN THE RANGE OF FROM ABOUT 3.5 TO ABOUT 6, A POUR POINT WITHIN THE RANGE OF FROM ABOUT 5*F. TO ABOUT 10*F., A CARBON RESIDUE WITHIN THE RANGE OF FROM ABOUT 0.33 TO ABOUT 0.54% BY WEIGHT, A SULFUR (BOMB) CONTENT WITHIN THE RANGE OF FROM ABOUT 0.0,% TO ABOUT 0.23% BY WEIGHT, AND A NEUTRALIZATION NUMBER WITHIN THE RANGE OF FROM ABOUT 0.03 TO ABOUT 0.09, SAID OIL BEING THE PRODUCT OBTAINED BY IN SEQUENCE SUBJECTING A PARAFFIN BASE RESIDUAL LUBRICATING OIL FRACTION TO SOLVENT DEASPHALTING, SOLVENT REFINING, AND SOLVENT DEWAXING AND THEREAFTER HYDROGENATING THE RESULTING TREATED OIL FRACTION WITH ADDED HYDROGEN AND IN THE PRESENCE OF A HYDROGENATION CATALYST SELECTED FROM THE GROUP CONSISTING OF MOLYBDENUM SULFIDE AND COBALT OXIDE-MOLYBDENUM OXIDE AT A TEMPERATURE WITHIN THE RANGE OF FROM ABOUT 417* TO ABOUT 606*F., A PRESSURE WITHIN THE RANGE OF FROM ABOUT 500 TO ABOUT 1000 P.S.I.G., A SPACE VELOCITY WITHIN THE RANGE OF FROM ABOUT 0.23 TO ABOUT 1.7 AND A HYDROGEN RECYCLE RATE OF FROM ABOUT 3100 TO ABOUT 10,000 STANDARD CUBIC FEET OF HYDROGEN PER BARREL OF OIL.