Dinuclear Metallocene Catalyst for Polyolefin Productivity
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Solution Overview
Problem
Current catalysts, such as Zeigler-Natta and metallocene catalysts, face limitations in achieving desired polyolefin properties like uniform molecular weight distribution and reactivity, with metallocene catalysts having issues with productivity and reactor fouling, and existing dinuclear metallocene catalysts facing challenges in structure modification and substituent addition.
Innovation Solution
A novel dinuclear metallocene compound with a specific structure, bridged by a phenylene group and crosslinked by an alkylenedioxy chain, is used in conjunction with cocatalysts to form a catalyst composition that allows for high molecular weight polyolefin production with controlled electronic and steric environments, enhancing catalytic activity and accessibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a metallocene catalyst is used to achieve narrow molecular weight distribution and controlled polymer properties, then the molecular weight distribution is narrowed and polymer properties are controlled, but productivity is remarkably decreased due to extrusion load
Solution Approach 1:
The patent combines a dinuclear metallocene catalyst system with a specific carrier material to create a composite catalyst system. This merging allows the catalyst to maintain the narrow molecular weight distribution characteristic of metallocene catalysts while the carrier system addresses the productivity issue by reducing extrusion load and improving overall catalytic efficiency.
Solution Approach 2:
The patent modifies the catalyst structure by introducing a dinuclear metallocene compound with specific ligands and steric environments. This parameter change in the catalyst structure enables simultaneous achievement of narrow molecular weight distribution and improved productivity by optimizing the active sites for both precision polymerization and high catalytic activity.
2Power
If a dinuclear metallocene catalyst is used to increase catalytic activity and molecular weight, then catalytic activity and molecular weight increase, but the metallocene catalyst part dissociates in the carrier component causing reactor fouling
Solution Approach 1:
The patent introduces a specifically designed carrier material that acts as an intermediary between the dinuclear metallocene catalyst and the reaction environment. This carrier prevents dissociation of the catalyst components while maintaining high catalytic activity, thereby eliminating reactor fouling without sacrificing power output.
Solution Approach 2:
Instead of allowing the catalyst to remain freely mobile in the reaction medium, the patent inverts the approach by anchoring the dinuclear metallocene catalyst to a solid carrier. This inversion prevents catalyst dissociation and reactor fouling while the controlled accessibility of active sites maintains high catalytic activity through the carrier's structured surface.
3Productivity
If existing dinuclear metallocene catalyst structures are used, then some copolymer incorporation and activity increase are achieved, but addition of substituents and structure modification is problematic
Solution Approach 1:
The patent segments the catalyst system into distinct modular components: the dinuclear metallocene core, specific ligand units, and carrier material. This segmentation allows independent optimization of each component, enabling easy modification of substituents and structure without compromising the overall catalytic function and copolymer incorporation capability.
Solution Approach 2:
The patent designs a universal catalyst framework based on the dinuclear metallocene structure that can accommodate multiple substituents and ligand configurations. This multi-functional design allows the same basic catalyst architecture to achieve high copolymer incorporation while facilitating easy structure modification for different applications.
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
The novel dinuclear metallocene catalyst composition achieves high activity and wide molecular weight distribution for polyolefin production, improving productivity and controlling polymer properties, while minimizing unnecessary metal interactions for stable catalytic performance.
Implementation Method 1
a catalyst composition comprising a dinuclear metallocene compound... which can prepare polyolefin with high molecular weight
Data Source
AI summary
This disclosure relates to a catalyst composition that can prepare polyolefin having high molecular weight, a method for preparing the same, and a method for preparing polyolefin using the same. The dinuclear metallocene compound included in the catalyst composition according to the present invention is a dinuclear metallocene compound with a new structure, and, unlike a single-site catalyst, has high accessibility to a substrate, and thus, can provide a multi-site catalyst with high activity.