摘要 |
Catalyst system comprising (a) a procatalyst composition comprising (i) a transition metal compound of Group 4 to 6 of the Periodic table (IUPAC, Nomenclature of Inorganic Chemistry, 1989), (i) M9Cl2 and (ii) an internal donor, wherein (iii) said internal donor comprises a dialkylphthalate of formula (ii) wherein R1 and R2 are independently a C1 or C2 alkyl and (b) an external donor wherein the external donor has the formula (IV) R′R″Si(OCH2CH3)2 (IV) wherein R′ and R″ are identical or different hydrocarbon residues.
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