Fused Ligand Transition Metal Catalyst for High-Temperature Olefin Polymerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current catalysts for olefin polymerization, such as those derived from constrained-geometry catalysts, do not achieve significant improvements in activity, copolymerization performance, and practical application in commercial plants, necessitating the development of novel transition metal and ligand compounds for enhanced polymerization performance.
Innovation Solution
A novel transition metal compound and ligand compound are introduced, characterized by a structure where cyclopentadiene is fused with benzothiophene via a ring-type bond and an amido group, stably bridged by Si, C, N, or P, enabling high activity in olefin polymerization at high temperatures and producing polyolefins with low density and high molecular weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional metallocene catalysts are used, then polymerization can be performed, but activity is low and molecular weight is limited at high polymerization temperatures
Solution Approach 1:
The patent modifies the ligand structure by introducing a fused ring system (cyclopentadiene fused with benzothiophene) and specific bridging groups (silicon, carbon, nitrogen, or phosphorous) to change the steric and electronic parameters of the catalyst. This structural modification enables the catalyst to maintain high activity and produce high molecular weight polymers even at elevated polymerization temperatures where conventional metallocene catalysts fail
Solution Approach 2:
The catalyst employs a composite ligand structure combining cyclopentadiene and benzothiophene rings with various bridging elements (Si, C, N, P) to create a constrained-geometry catalyst system. This composite structure provides both the stability needed for high-temperature operation and the appropriate steric environment for maintaining high polymerization activity and molecular weight
2Productivity
If conventional metallocene catalysts are used, then copolymerization can be performed, but copolymerization degree of alpha-olefins with large steric hindrance is insufficient
Solution Approach 1:
The patent creates a localized steric environment at the metal center through the constrained geometry of the ligand system. The fused ring structure and bridging groups create a specific spatial configuration that accommodates bulky alpha-olefin monomers (such as 1-hexene and 1-octene) while maintaining catalytic activity, enabling high copolymerization degrees that are not achievable with conventional metallocene catalysts
3Productivity
If derivatives of constrained-geometry catalysts are synthesized, then polymerization performance may be improved, but synthesis complexity increases
Solution Approach 1:
The ligand synthesis is divided into discrete steps: first forming the core fused ring system (cyclopentadiene-benzothiophene), then introducing the appropriate bridging groups (Si, C, N, or P) in subsequent steps. This segmented approach allows for systematic optimization of different bridge types while maintaining a consistent core structure, managing synthesis complexity through modular design
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 catalyst composition achieves high activity and copolymerization performance, allowing for the production of polyolefins with low density and high molecular weight, particularly suitable for applications requiring polymers with low melt index and high molecular weight.
Implementation Method 1
a transition metal compound represented by the following Formula 1: M is a transition metal in group 4... useful as a catalyst of polymerization reaction for preparing an olefin-based polymer
Data Source
AI summary
The present invention relates to a novel ligand compound, a transition metal compound and a catalyst composition including the same. The novel ligand compound and the transition metal compound of the present invention may be useful as a catalyst of polymerization reaction for preparing an olefin-based polymer having a low density. In addition, an olefin polymer which is polymerized using the catalyst composition including the transition metal compound may be used for the manufacture of a product having low melt index (MI) and high molecular weight.