Bridged Bis Indenyl Metallocene Catalyst for Olefin Polymerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for new and improved catalyst systems for olefin polymerization to achieve specific polymer properties such as high melting point, high molecular weights, increased conversion, and altered comonomer distribution without compromising the polymer's properties.
Innovation Solution
The development of novel bridged transition metal complexes, specifically represented by the formula (I), which include —Si—Si— bridges and are used in catalyst systems for olefin polymerization, allowing for the production of polymers with controlled comonomer incorporation and high molecular weights.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional metallocene catalysts are used for olefin polymerization, then catalyst activity is maintained, but comonomer incorporation is too high and molecular weight is limited
Solution Approach 1:
The patent modifies the catalyst structure by introducing a disiladiyl bridge between indenyl groups, changing the steric and electronic parameters of the catalyst. This structural parameter change controls the polymerization mechanism to achieve less than 20% comonomer incorporation by weight while maintaining high molecular weights, resolving the trade-off between comonomer incorporation and molecular weight
2Manufacturing precision
If catalyst structure is modified to control polymer properties, then specific polymer properties are achieved, but catalyst complexity increases
Solution Approach 1:
The patent creates a composite catalyst structure combining indenyl groups with a disiladiyl bridge (—Si—Si—) connecting them. This composite molecular structure integrates multiple functional elements (indenyl ligands, silicon atoms, bridging units) to achieve precise control over polymer properties including comonomer incorporation below 20% by weight and high molecular weights, while the systematic design keeps the complexity manageable
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
These catalyst systems produce polymers with less than 20% comonomer incorporation by weight, achieving high molecular weights while maintaining good catalyst activity and specific polymer properties.
Implementation Method 1
novel bridged transition metal complexes represented by the formula (I) wherein M1 is selected from the group consisting of titanium, zirconium, hafnium... R13 is —((R15*)2Si—Si(R15)2)—
Data Source
AI summary
This invention relates to novel bridged bis indenyl metallocene catalyst compounds where the bridge is —((R15*)2Si—Si(R15)2)— wherein, each R15 and R15* is identical or different and is a substituted or unsubstituted, branched or unbranched C1-C20 alkyl group, preferably each R15 together do not form a ring, and/or each R15* together do not form a ring, and/or R15 and R15* together do not form a ring. This invention also relates to polymerization processes to produce polymer and to polymer compositions produced by the methods described.