| abstract |
The present invention relates to a process for the preparation of procatalysts for the polymerization of olefins, said process comprising combining a magnesium-containing support with a halogen-containing titanium compound, a monoester, a first internal electron donor and optionally a compound selected from diesters and diethers The second internal electron donor is contacted, wherein the first internal electron donor is represented by a compound represented by general formula A (such as the Fischer projection of general formula A), and the method comprises the steps of: i) making the butyl Grignard compound and Alkoxy or aryloxy-containing silane compounds are contacted to obtain a first intermediate reaction product; ii) optionally using at least one activating compound to activate the first intermediate reaction product to obtain a second intermediate reaction product; iii) making The first or second intermediate reaction product obtained in step i) or ii), respectively, and the halogen-containing Ti compound, monoester and the internal compound represented by the compound represented by general formula A (such as the Fischer projection of general formula A) The electron donor is contacted as a first internal electron donor and the optional diester or diether as a second internal electron donor. The present invention also relates to a polymerization catalyst system comprising said procatalyst, cocatalyst and optionally an external electron donor. In addition, the invention relates to polyolefins obtainable by the process of the invention and shaped articles thereof. |