Solid Support Polymethylaluminoxane Complex for Polymerization
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Solution Overview
Problem
Conventional supported solid polymethylaluminoxane compositions exhibit lower polymerization activity compared to liquid forms, and the selection of suitable solid supports is limited, leading to issues like polymer fouling and reduced catalyst efficiency in polymerization processes.
Innovation Solution
A solid support-polymethylaluminoxane complex is developed with a coating layer of polymethylaluminoxane and trimethylaluminum on a solid support, specifically optimized in terms of aluminum content, mole fraction of methyl groups, and specific surface area, allowing for higher polymerization activity and improved catalyst performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If solid inorganic supports such as silica are used to support polymethylaluminoxane composition, then the polymerization system can be applied to suspension or vapor phase polymerization, but the polymerization activity drops significantly compared to homogeneous systems
Solution Approach 1:
The invention changes the physical and chemical parameters of the support by using solid polymethylaluminoxane composition instead of conventional inorganic supports. This composition has controlled aluminum content (36-41 mass%) and controlled mole fraction of methyl groups (≤12 mol%), which optimizes the polymerization activity while maintaining the solid state benefits for suspension or vapor phase polymerization.
Solution Approach 2:
The invention creates a composite material where polymethylaluminoxane composition is supported on a solid support. The composite combines the advantages of solid supports (ease of handling in suspension or vapor phase) with the high activity of polymethylaluminoxane, achieving both operational flexibility and high polymerization activity.
2Ease of operation
If conventional solid supports are used, then the polymethylaluminoxane composition can be in solid state for improved handling, but the support remains on the polymer causing fisheyes and other defects
Solution Approach 1:
The invention changes the chemical composition parameters by controlling the aluminum content (36-41 mass%) and the mole fraction of methyl groups (≤12 mol%). This optimization reduces the negative impact of the support on the polymer quality, minimizing fisheyes and other defects while maintaining solid state handling advantages.
3Ease of manufacture
If the aluminum content and methyl group composition are not controlled in the polymethylaluminoxane composition, then the preparation is simpler, but the polymerization activity and catalyst performance are reduced
Solution Approach 1:
The invention establishes specific parameter ranges for aluminum content (36-41 mass%) and mole fraction of methyl groups (≤12 mol%). These controlled parameters ensure high polymerization activity and catalyst performance while maintaining a practical preparation process. The parameters are optimized to balance manufacturing feasibility with catalytic effectiveness.
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 complex demonstrates enhanced polymerization activity and reduced fouling, enabling high-yield production of polyolefins with improved catalyst efficiency and industrial applicability.
Implementation Method 1
They are known to be useful as co-catalysts that efficiently activate the transition metal compounds serving as primary catalysts in the producing of olefin polymers
Implementation Method 2
a coating layer comprising polymethylaluminoxane and trimethylaluminum is present on at least part, or all, of the surface of a solid support
Data Source
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AI summary
Disclosed is a solid support-polymethylaluminoxane complex exhibiting a higher polymerization activity than a conventional substance and being homogeneous. Also disclosed is a method for producing an olefin-based polymer having a favorable quality using the complex and a transition metal compound. The complex comprises a coating layer comprising polymethylaluminoxane and trimethylaluminum on the surface of a solid support. The coating layer comprises a solid polymethylaluminoxane composition in which (i) the content of aluminum is in a range of 36 to 41 mass% and (ii) the molar fraction of methyl groups derived from a trimethylaluminum moiety to the total number of moles of methyl groups is 12 mol% or less. Also disclosed is an olefin polymerization catalyst comprising the complex and a transition metal compound represented by general formula (III): MR5R6R7R8 as catalyst components, and a method for producing a polyolefin comprising polymerizing an olefin using the catalyst.