Temperature-staged catalyst pretreatment

Claim 1

A CONTINUOUS PROCESS FOR MAKING A NORMAL C3-C4 ALPHA MONOOLEFIN POLYMERIZATION CATALYST WHICH COMPRISES CONTINUOUSLY AGITATING A MIXTURE CONSISTING ESSENTIALLY OF AN ALUMINUM TRIALKYL, THE ALKYL GROUP HAVING FROM 2-4 CARBON ATOMS AND A TITANIUM TETRAHALIDE SELECTED FROM THE GROUP CONSISTING OF TITANIUM TETRACHLORIDE AND TITANIUM TETRABROMIDE IN A HYDROCARBON SOLUTION TO GIVE A MIXTURE HAVING AN AL/TI RATIO OF ABOUT 0.1/1 TO 0.8/1, MAINTAINING THE MIXTURE IN A FIRST PRETREATMENT ZONE AT A TEMPERATURE BETWEEN ABOUT 0* AND 35*C. AND AN AVERAGE RESIDENCE OF ABOUT 0.1 TO 60 MINUTES, CONTINUOUSLY PASSING THE RESULTING LIQUID MIXTURE TO AT LEAST ONE SUBSEQUENT PRETREATMENT ZONE, AND MAINTAINING THE MIXTURE IN SAID SUBSEQUENT PRETREATMENT ZONE AT A TEMPERATURE OF ABOUT 55* TO 150*C. FOR AN AVERAGE RESIDENCE OF ABOUT 5 TO 120 MINUTES UNTIL SUBSTANTIALLY ALL TITANIUM IS REDUCED TO A VALENCE RANGING FROM ABOUT 2.1 TO 3.