摘要:
This invention relates to catalyst compositions, methods, and polymers encompassing at least one Group 4 metallocene compound comprising bridging η5-cyclopentadienyl-type ligands, typically in combination with at least one cocatalyst, and at least one activator. The compositions and methods disclosed herein provide ethylene polymers with low levels of long chain branching.
摘要:
This invention relates to catalyst compositions, methods, and polymers encompassing at least one first Group 4 metallocene compound comprising bridging η5-cyclopentadienyl-type ligands, in combination with at least one second Group 4 metallocene with non-bridging η5-cyclopentadienyl-type ligands, typically in combination with at least one cocatalyst, and at least one activator. The compositions and methods disclosed herein provide ethylene polymers with a bimodal molecular weight distribution.
摘要:
This invention relates to catalyst compositions, methods, and polymers encompassing at least one first Group 4 metallocene compound comprising bridging η5-cyclopentadienyl-type ligands, in combination with at least one second Group 4 metallocene with non-bridging η5-cyclopentadienyl-type ligands, typically in combination with at least one cocatalyst, and at least one activator. The compositions and methods disclosed herein provide ethylene polymers with a bimodal molecular weight distribution.
摘要:
Catalyst deactivating agents and compositions containing catalyst deactivating agents are disclosed. These catalyst deactivating agents can be used in methods of controlling polymerization reactions, methods of terminating polymerization reactions, methods of operating polymerization reactors, and methods of transitioning between catalyst systems.
摘要:
The present invention provides polymerization catalyst compositions employing novel heterodinuclear metallocene compounds. Methods for making these new dinuclear metallocene compounds and for using such compounds in catalyst compositions for the polymerization of olefins are also provided.
摘要:
The present invention provides polymerization catalyst compositions employing novel heterodinuclear metallocene compounds. Methods for making these new dinuclear metallocene compounds and for using such compounds in catalyst compositions for the polymerization of olefins are also provided.
摘要:
An exemplary housing mechanism (100) for an electronic device includes a front cover (10), a back cover (20), and an elastic sealing element (12). The front cover has a projecting edge (18) defined thereon. The back cover has a recessed edge (26) defined therein. The elastic sealing element has a tip portion (122) and is formed or sealed together with the front cover. The projecting edge of the front cover and the tip portion of the elastic sealing element are configured to be press fit into the recessed edge of the back cover.
摘要:
Metallocene compounds and pharmaceutical compositions containing these metallocene compounds are disclosed and described. Methods of treating cancer employing such metallocene compounds and pharmaceutical compositions also are provided.