High Activity Catalyst Compositions Containing Silicon-Bridged Metallocenes With Bulky Substituents (Chevron Phillips)

PATENT
High Activity Catalyst Compositions Containing Silicon-Bridged Metallocenes With Bulky Substituents (Chevron Phillips)
Publication number US20130217842 A1
Publication type Application
Application number US 13/849,595
Publication date Aug 22, 2013
Also published as US8431729, US20130035458, WO2013019769A1
Inventors
Joel L. Martin, Qing Yang, Max P. McDaniel, Jim B. Askew
Original Assignee
Chevron Phillips Chemical Company Lp
Abstract
The present invention discloses catalyst compositions employing silicon-bridged metallocene compounds with bulky substituents. Methods for making these silicon-bridged metallocene compounds and for using such compounds in catalyst compositions for the polymerization of olefins also are provided.
Description
BACKGROUND OF THE INVENTION
Polyolefins such as high density polyethylene (HDPE) homopolymer and linear low density polyethylene (LLDPE) copolymer can be produced using various combinations of catalyst systems and polymerization processes. In some end-use applications, it can be beneficial for the polymer to have a high molecular weight. Moreover, it can be beneficial for the catalyst system employed to have a high catalytic activity for olefin polymerization, resulting in lower reactor catalyst concentration, lower overall cost, and improved operational efficiency. Accordingly, it is to these ends that the present invention is directed.
SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify required or essential features of the claimed subject matter. Nor is this summary intended to be used to limit the scope of the claimed subject matter.
The present invention generally relates to new catalyst compositions, methods for preparing catalyst compositions, methods for using the catalyst compositions to polymerize olefins, the polymer resins produced using such catalyst compositions, and articles produced using these polymer resins. In particular, the present invention relates to silicon-bridged metallocene compounds with bulky substituents, and catalyst compositions employing such bridged metallocene compounds. Catalyst compositions of the present invention which contain these silicon-bridged metallocene compounds can be used to produce, for example, ethylene-based homopolymers and copolymers.
In formula (I), M can be Ti, Zr, or Hf, X¹ and X² independently can be a monoanionic R^A can be a C₂ to C₁₈ alkenyl group, and n can be 0 or 1.
Catalyst compositions containing the silicon-bridged metallocene compounds of formula (I), or derivatives thereof, also are provided by the present invention. In one aspect, a catalyst composition is disclosed which comprises a silicon-bridged metallocene compound of formula (I), or a derivative thereof, and an activator. This catalyst composition can further comprise an organoaluminum compound. In some aspects, the activator can comprise an activator-support, while in other aspects, the activator can comprise an aluminoxane compound, an organoboron or organoborate compound, an ionizing ionic compound, or combinations thereof.
The present invention also contemplates and encompasses olefin polymerization processes. Such processes can comprise contacting a catalyst composition with an olefin monomer and optionally an olefin comonomer under polymerization conditions to produce an olefin polymer. Generally, the catalyst composition employed can comprise any of the silicon-bridged metallocene compounds disclosed herein and any of the activators disclosed herein. Further, organoaluminum compounds also can be utilized in the catalyst compositions and/or polymerization processes.
Polymers produced from the polymerization of olefins, resulting in homopolymers, copolymers, terpolymers, etc., can be used to produce various articles of manufacture.
Both the foregoing summary and the following detailed description provide examples and are explanatory only. Accordingly, the foregoing summary and the following detailed description should not be considered to be restrictive. Further, features or variations may be provided in addition to those set forth herein. For example, certain embodiments may be directed to various feature combinations and sub-combinations described in the detailed description.
Free Full Text Source: https://www.google.com/patents/US20130217842?dq=hydrogen+inassignee:chevron&hl=en&sa=X&ei=Y0zxUt3XIJOMyAG4uIG4Bg&ved=0CDMQ6AEwADge