Metallocene Catalyst for High Molecular Weight Olefin Polymers

The patent modifies the chemical structure of the metallocene catalyst by introducing specific substituents (such as -CH 2SiMe 3, -CH 2SiMe 2Ph, -CH 2SiPh 3) on the cyclopentadienyl rings and using bridged structures. These structural parameter changes enhance the catalyst's electronic and steric properties, allowing it to maintain high polymerization activity even when supported on solid carriers like silica gel or alumina.

The patent introduces specific local structural features into the metallocene catalyst, including bridged structures (such as dimethylsilyl bridges) and specific substituents at particular positions on the cyclopentadienyl rings. These localized structural modifications create unique electronic and steric environments at the catalyst active site that reduce hydrogen coordination strength, allowing the catalyst to maintain high activity while still controlling polymer molecular weight through other mechanisms.

The patent creates composite catalyst structures by combining metallocene cores with bridged ligand systems and specific substituents. The bridged structure (such as -SiMe 2- bridges between cyclopentadienyl rings) creates a rigid framework that positions substituents in specific spatial arrangements. This composite structure provides both the electronic properties needed for high copolymerization ability and the steric configuration needed to accommodate bulky alpha-olefin comonomers like 1-octene and 1-decene.