Bis(phenolate) Transition Metal Catalysts for High-Tacticity Olefin Polymerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a need for new catalyst systems that can produce high molecular weight and/or high tacticity polymers at high process temperatures, as existing catalysts for olefin polymerization do not effectively achieve these properties.
Innovation Solution
Transition metal complexes with a dianionic, tridentate ligand featuring a central neutral heterocyclic Lewis base and two phenolate donors, which coordinate to form two eight-membered rings, are used to create catalyst systems for olefin polymerization, enhancing polymer properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional olefin polymerization catalysts are used, then polymerization can proceed, but high molecular weight and high tacticity polymers cannot be effectively produced at high process temperatures
Solution Approach 1:
The patent modifies the catalyst structure by introducing a specific bis(phenolate) ligand system with particular steric and electronic properties. This changes the catalyst's parameters to enable it to maintain high activity and selectivity at elevated temperatures, thereby producing high tacticity polymers at high process temperatures where conventional catalysts fail
Solution Approach 2:
The catalyst system combines a transition metal center with a specially designed bis(phenolate) ligand framework, creating a composite catalytic system. This composite structure integrates the metal's catalytic activity with the ligand's steric control, enabling simultaneous achievement of high polymerization temperature tolerance and high tacticity production
2Strength
If conventional catalysts are used, then polymerization can occur, but high molecular weight polymers are not effectively produced
Solution Approach 1:
The patent optimizes catalyst parameters including metal selection (groups 3-6 or lanthanides), ligand substitution patterns, and steric bulk to create a catalyst that produces high molecular weight polymers while maintaining high productivity. The specific bis(phenolate) ligand design prevents premature chain termination and maintains catalyst activity
Solution Approach 2:
The catalyst design incorporates localized steric control through specific substituents on the phenolate rings (such as adamantyl or other bulky groups at ortho positions). This local steric environment controls the polymerization process to favor high molecular weight formation while maintaining overall catalyst productivity
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 effectively produce high molecular weight and high tacticity polymers at high temperatures, improving the industrial production of polyolefins by enhancing catalyst productivity and activity.
Implementation Method 1
Transition metal complexes with a dianionic, tridentate ligand featuring a central neutral heterocyclic Lewis base and two phenolate donors, which coordinate to form two eight-membered rings
Implementation Method 2
These catalyst systems effectively produce high molecular weight and high tacticity polymers at high temperatures, improving the industrial production of polyolefins by enhancing catalyst productivity and activity
Data Source
AI summary
This invention relates to transition metal complexes of a dianionic, tridentate ligand that features a central neutral heterocyclic Lewis base and two phenolate donors, where the tridentate ligand coordinates to the metal center to form two eight-membered rings. Preferably the bis(phenolate) complexes are represented by Formula (I):where M, L, X, m, n, E, E′, Q, R1, R2, R3, R4, R1′, R2′, R3′, R4′, A1, A1′,are as defined herein, where A1QA1′ are part of a heterocyclic Lewis base containing 4 to 40 non-hydrogen atoms that links A2 to A2′ via a 3-atom bridge with Q being the central atom of the 3-atom bridge.