Patent ID: 8138112

Claim:
A method for activating a Ziegler-Natta pre-catalyst component comprising: providing a Ziegler-Natta pre-catalyst component, wherein the Ziegler-Natta pre-catalyst component comprises magnesium, titanium, an amount of chlorine sufficient to chlorinate Mg and Ti and form MgCl 2 and TiCl 4 and internal electron donor(s) that comprise at least two distinct oxygen-containing functions; submitting the pre-catalyst component to a thermal treatment carried out at a temperature of from 80 to 150° C. under vacuum better than 10 −5 bars; treating the pre-catalyst component by adding a Lewis acid BX 3 that is a boron compound soluble in apolar solvents, wherein X is halogen or alkyl group; optionally further treating the Ziegler-Natta pre-catalyst component with a titanium compound TiX 4 before or after treatment with the Lewis acid; adding aluminium compound of general formula AlR n Z 3-n wherein R is alkyl group having from 1 to 10 carbon atoms, Z is halogen and n is 0, 1, 2 or 3; and optionally adding an external electron donor either of general formula SiR a m (OR b ) 4-m or of general formula R′O—(CH2—CR 1 R 2 —CH2)—OR′ wherein R a and R b are each independently selected from alkyl, aryl, cycloalkyl, arylalkyl or alkylaryl having at most 12 carbon atoms, and two neighbouring R can be linked together to make a ring, m is 0 or an integer from 1 to 4, wherein each R′, R 1 and R 2 is independently selected from alkyl, aryl, cycloalkyl, arylalkyl or alkylaryl having at most 12 carbon atoms, and R 1 and R 2 can be linked together to make a ring or rings.