| 摘要 |
Certain metallocene compounds are provided that, when used as a component in a supported polymerization catalyst under industrially relevant polymerization conditions, afford high molar mass homo polymers or copolymers like polypropylene or propylene/ethylene copolymers without the need for any a -branched substituent in either of the two available 2- positions of the indenyl ligands. The substituent in the 2-position of one indenyl ligand can be any radical comprising hydrogen, methyl, or any other C2-C40 hydrocarbon which is not branched in the a -position, and the substituent in the 2-position of the other indenyl ligand can be any C5-C40 hydrocarbon radical with the proviso that this hydrocarbon radical is branched in the ß-position and that the ß-carbon atom is a quarternary carbon atom and part of a mono-cyclic hydrocarbon system. This metallocene topology affords high melting point, very high molar mass homo polypropylene and very high molar mass propylene-based copolymers. Furthermore, the activity/productivity levels of catalysts comprising the metallocenes of the present invention are exceptionally high. |
