Polyolefin process and catalyst

Claim 1

IN A POLYMERIZATION PROCESS WHICH COMPRISES TREATING A CATALYST CONSISTING OF EITHER A CRYSTALLINE TITANIUM TRICHLORIDE OR A COCYSTALLIZED TITANIUM TRICHLORIDE-ALUMINUM CHLORIDE COMPLEX HAVING THE FORMULA 3TICL3 AICI3 WITH AN ORGANALUMINUM COMPOUND AND USING THE TREATED CATALYST FOR THE POLYMERIZATION OF AN ALPHA OLEFIN, THE IMPROVEMENT WHICH COMPRISES PRETREATING SAID CATALYST IN THE FOLLOWING STEPS: (1) ADDING ALUMINUM TRIETHYL TO SAID CATALYSST IN AN AMOUND OF ABUT 25 TO 75% BY VOLUME OF THE TOTAL ORGANALALUMINUM COMPOUND REQUIRED FOR A FINAL ALUMINUM/TITANIUM METAL RATIO OF ABOUT 1:1 TO 5:1 IN A DILUENT AT A TEMPERATURE OF ABOUT 50* TO 70*C. FOR A PERIOD OF ABOUT 3 TO 30 MINUTES TO FORM A CATALYST SLURRY. (2) ADDING TO THE CATALYST SLURRY THE REMAINING 75 TO 25% BY VOLUME OF THE ORGANALUMINUM COMPOUND REQUIRED TO BRING THE TOTAL ALUMINUM/TITANIUM METAL RATIO OF THE CATALYST TO ABOUT 1:1 TO 5:1 AT A TEMPERATURE OF ABOUT 20* TO 60*C. AND POLYMERIZING SAID ALPHA OLEFIN AT A TEMPERATURE OF AT LEAST ABOVE 60*C. IN THE PRESENCE OF SAID PRETREATRED CATALYST.