| abstract |
The invention relates to a procatalyst for the production of ethylene polymers, which procatalyst comprises an inorganic support, a chlorine compound carried on said support, a magnesium compound carried on said support, a titanium compound carried on said support, whereby the chlorine compound can be different from or the same as the magnesium compound and/or the titanium compound. The activity balance AB of the procatalyst in specified polymerization conditions, is AB > 3.2 wherein AB = [(A + A'):2] · [log (MFR₂' : MFR₂) : (A - A')] , A means polymerization activity expressed as kg PE / g cat · h, MFR₂ means the melt flow rate in g/min units at a load of 2,16 kg, according to the standard ISO 1133, the absence of the upper index ' means low melt flow rate polymerization and the presence of the upper index ' means high melt flow polymerization. This means that the catalyst activity is relatively independent of the presence of chain transfer agents. |