Ink oil and method of manufacture

Claim 1

A PROCESS FOR THE MANUFACTURE OF INK OIL WHICH COMPRISES CONTACTING A WAXY PETROLEUM DISTILLATE FRACTION WITH LIQUID FURFURAL AS A SELECTIVE SOLVENT WHICH SELECTIVELY DISSOLVES THE MORE AROMATIC PHYDROCARBONS THEREFROM, SAID SELECTIVE SOLVENT BEING AT LEAST PARTIALLY IMMISCIBLE WITH SAID PETROLEUM DISTILLATE FRACTION UNDER THE CONDITIONS OF CONTRACTING, TO YIELD AN EXTRACT CHARACTERIZED BY A RELATIVELY INCREASED PROPORTION OF AROMATIC HYDROCARBONS AS COMPARED WITH SAID DISTILLATE FRACTION, CONTACTING SAID EXTRACT WITH CONCENTRATED SULFURIC ACID, NEUTRALIZING THE RESULTING TREATED OIL WITH A NEUTRALIZING AGENT FOR SULFURIC ACID SELECTED FROM THE GROUP CONSISTING OF SODIUM CARBONATE, SODIUM BICARBONATE AND SODIUM HYDROXIDE AND ADMIXING THE RESULTING ACID TREATED, NEUTRALIZED EXTRACT WITH A MINOR AMOUNT IN THE RANGE 3-20% VOL. OF A NAPHTHENE BASE OIL AND A MINOR AMOUNT IN THE RANGE 0.05-1.5% VOL. OF A POUR POINT DEPRESSANT TO YIELD A FINISHED INK OIL, SAID INK OIL HAVING AN API GRAVITY NOT IN EXCERSS OF 22, A TAG-ROBINSON COLOR OF AT LEAST 1.0, A POUR POINT NOT IN EXCESS OF +30*F., WHICH INK OIL UPON ADMIXTURE WITH CARBON BLACK, WHEREIN CARBON BLACK COMPRISES ABOUT 5% BY WEIGHT OF THE ADMIXTURE, SHOWS NO APPRECIABLE OIL SEPARATION, GEL FORMATION OR THICKENING AFTER AGING ABOUT 164 HOURS AT 120*F.