Hybrid Supported Metallocene Catalyst for Olefin Polymerization
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Solution Overview
Problem
Existing methods for preparing olefinic polymers using hybrid metallocene catalysts face challenges in achieving high molecular weight and desired physical properties due to complex supporting procedures, limited activity, and fouling issues in reactors.
Innovation Solution
A hybrid supported metallocene catalyst system comprising one or more first metallocene compounds with indenoindole or fluorene derivatives crosslinked via a bridge, combined with second metallocene compounds and a cocatalyst, supported on a Lewis acid surface to enhance polymerization activity and molecular weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple metallocene compounds are supported on separate supports, then molecular weight distribution can be controlled, but the supporting procedure becomes complex and time-consuming
Solution Approach 1:
The patent combines multiple metallocene compounds (first metallocene compound and second metallocene compound) onto a single support material, eliminating the need for separate supporting procedures for each catalyst. This merging approach maintains the ability to control molecular weight distribution while significantly simplifying the overall supporting procedure and reducing process complexity.
Solution Approach 2:
The single support material serves multiple functions by simultaneously carrying different metallocene compounds with distinct catalytic activities. The support acts as a universal platform that enables both high molecular weight polymer production (via first metallocene) and low molecular weight polymer production (via second metallocene), consolidating what would otherwise require multiple specialized supports.
2Reliability
If metallocene catalysts are supported using conventional methods, then catalyst activity can be maintained, but the supporting process requires large amounts of solvent and long preparation time
Solution Approach 1:
The support material is pre-modified with functional groups (such as silane groups) before the metallocene compounds are introduced. This preliminary action creates ready-to-bind sites on the support surface, enabling direct and rapid attachment of the metallocene catalysts without requiring lengthy conventional supporting procedures, thereby reducing preparation time while maintaining catalyst activity.
Solution Approach 2:
The patent introduces a coupling agent or functional group as an intermediary between the support material and the metallocene compounds. This intermediary facilitates rapid and effective binding, eliminating the need for large amounts of solvent and extended reaction times typically required in conventional supporting methods, thus reducing preparation time while preserving catalyst activity.
3Manufacturing precision
If hybrid metallocene catalysts are used to produce high molecular weight polymers, then desired physical properties are achieved, but fouling occurs in the reactor due to catalyst departure
Solution Approach 1:
The patent converts the potential harm of catalyst departure into a benefit by using a support material with strong anchoring capabilities. The support not only prevents unwanted catalyst detachment that causes fouling but also leverages the synergistic interaction between multiple metallocene compounds to enhance polymerization activity and control polymer properties, thereby eliminating fouling while achieving desired physical properties.
Solution Approach 2:
The patent employs a support material with specific surface characteristics (analogous to 'color' in material properties) that selectively interact with the metallocene compounds. The support's surface properties are optimized to strongly retain the catalysts, preventing their departure and subsequent reactor fouling, while still allowing the catalysts to function effectively in producing polymers with desired physical properties.
4Productivity
If Ziegler-Natta catalyst is used for polymerization, then high activity is achieved, but molecular weight distribution becomes broad and comonomer composition is non-uniform
Solution Approach 1:
The patent segments the catalytic function by using two distinct metallocene compounds with different activities and selectivities. The first metallocene compound (with indenoindole or fluorene derivative) produces high molecular weight polymer with uniform composition, while the second metallocene compound produces low molecular weight polymer. This segmentation of catalytic functions across two specialized catalysts enables precise control over molecular weight distribution while maintaining high overall polymerization activity.
Solution Approach 2:
The patent applies local quality by assigning different ligand structures to different metallocene compounds based on their specific functions. The first metallocene uses indenoindole or fluorene derivative ligands optimized for high molecular weight polymer production, while the second metallocene uses different ligands optimized for low molecular weight polymer production. This localized optimization of catalyst properties at each active site enables precise control over polymer characteristics while maintaining high activity.
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 catalyst system achieves high polymerization activity, producing olefinic polymers with ultra-high molecular weight and broad molecular weight distribution, maintaining activity even in the presence of hydrogen, and facilitating the preparation of polymers with desired physical properties.
Implementation Method 1
supported on a Lewis acid surface to enhance polymerization activity
Data Source
AI summary
The present invention relates to a hybrid supported metallocene catalyst. More specifically, the present invention relates to a hybrid supported metallocene catalyst using two or more different types or more of metallocene compounds, among which one type of the metallocene compounds shows a high polymerization activity even when it is supported, and thus the catalyst has an excellent activity and can be utilized in the polymerization of olefinic polymers having ultra-high molecular weight. Based on the hybrid supported metallocene catalyst of the present invention, an olefinic polymer having high molecular weight and the desired physical property can be prepared.