Process for the manufacture of electrode pitches

Claim 1

THE PROCESS FOR PREPARING AN ELECTRODE COAL TAR PITCH COMPOSITION CONTAINING AT LEAST 30% BY WEIGHT OF MEDIUM-MOLECULAR WEIGHT TAR RESINS COMPRISING MIXING A COAL TAR WITH A LIGHT COAL TAR OIL AND A COMPOUND IN AN AMOUNT UP TO APPROXIMATELY 5% BY WEIGHT OF THE MIXTURE AT A TEMPERATURE OF APPROXIMATELY 150*C. TO APPROXIMATELY 200*C., SAID COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF MANGANIC CHLORIDE, CHROMIC CHLORIDE, FERRIC CHLORIDE, NITROBENZENE SULFONIC ACID CHLORIDE, PARATOLUENE SULFONIC ACID CHLORIDE, AND NITRONAPHTHALENE SULFONIC ACID CHLORIDE, STIRRING THE SO-FORMED MIXTURE, AND DISTILLING THE SO-TREATED MIXTURE UNTIL THE RESIDUE HAS A SOFTENING POINT OF APPROXIMATELY 80*C. KRAMER-SARNOW, THEREBY OBTAINING A COAL TAR PITCH FOR FORMING ELECTRODES OF EXCEPTIONALLY GOOD STABILITY AND HIGH TENSILE STRENGTH.