Petroleum pitch and process for its manufacture

Claim 1

A PROCESS FOR THE PREPARTION OF A PETROLUM PITCH SUBSTANTIALLY COMPLETELY SOLUBLE IN BENZENE AND HAVING A SOFTENING POINT ABOVE 350*F. COMPRISING DISTILLING A REDUCED CRUDE PETROLEUM OIL SELECTED FROM THE GROUP CONSISTING OF PARAFFINIC AND MIED BASE CRUDE OILS UNDER A VACUUM TO PRODUCE A RESIDAL STOCK HAVING A CONRADSON CARBON NUMBER OF AT LEAST 18, AN API GRAVITY BELOW 10, AND A VISCOSITY, SUS AT 210*F. OF AT LEAST 6000, HEATING THE RESIDUAL STOCK TO A TEMPEATURE OF 900* TO ABOUT 100*F. AND QUICKLY THEREAFTER QUENCHING THE HEATED RESIDUAL STOCK TO BISBREAK THE REIDUAL STOCK IN A HIGH SEVERITY, SHORT-PERIOD VISBREAKING OPERATION, SAID VISBREAKING OPERATION YEILDING ABOUT 15% GASOLINE AND LIGHTER HYDROCARBONS, FLASHING LOW BOILING FRACTIONS FROM THE VISBROKEN PRODUCTS TO LEAVE A VISBROKEN BOTTOMS PRODUCT, HEATING THE VISBROKEN BOTTOMS, AND VACUUM DISTILLING THE THUS HEATED BOTTOMS AT A DISTILLATION TEMPERATURE ABOVE 1075*F., CORRECTED TO 760 MM. OF MERCURY ABSOLUTE PRESSURE, IN THE PRESENCE OF STEAM TO FORM THE PETROLEUM PITCH AS A RESIDUAL PRODUCT.