Polyfunctional Activator Compositions for High-Efficiency Metallocene Catalysis
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Solution Overview
Problem
Silica-supported methylaluminoxane catalysts have low efficiency due to the need for a large excess of methylaluminoxane and limited support capacity, resulting in inefficient activation of metallocenes in olefin polymerization.
Innovation Solution
Development of novel activator precursor compositions comprising a support material in contact with an organoaluminum compound and a polyfunctional compound with aromatic groups having polar monoprotic groups, enhancing catalyst efficiency and stability under inert conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If silica-supported methylaluminoxane is used as metallocene catalyst activator, then the catalyst system can activate metallocenes for polymerization, but the efficiency is low due to the need for large excess of methylaluminoxane and limited support capacity
Solution Approach 1:
The patent modifies the chemical composition and structure of the supported aluminoxane by introducing different aluminum compounds, support materials, and functional groups. This changes the parameters of the activator system to achieve higher metallocene activation efficiency with lower aluminum-to-metallocene ratios, directly resolving the contradiction between productivity and quantity of substance required.
Solution Approach 2:
The patent creates composite materials combining various support materials (silica, alumina, magnesium compounds) with modified aluminoxane species and organic compounds. These composite structures provide both high surface area for support and reactive sites for activation, enabling efficient metallocene activation without requiring large excess of aluminum compound, thus resolving the contradiction between productivity and quantity.
2Productivity
If large excess of methylaluminoxane is used to effectively activate metallocene molecules, then activation efficiency improves, but the amount of aluminum compound required increases significantly
Solution Approach 1:
The patent changes the chemical parameters of the activator system by using modified aluminoxane compositions with different aluminum compounds and ratios. This allows achieving effective metallocene activation at lower aluminum-to-metallocene ratios, resolving the contradiction between activation efficiency and aluminum compound quantity required.
Solution Approach 2:
The supported aluminoxane system is designed to be self-regulating in terms of activation efficiency. The support material and modified aluminoxane composition work together to provide sufficient activation capacity without requiring large excess of aluminum compound, enabling the system to achieve optimal performance with appropriate stoichiometry rather than large excess.
3Quantity of substance
If standard grades of silica are used as support, then the support capacity for methylaluminoxane is limited, but the system is simpler and more commercially available
Solution Approach 1:
The patent employs composite support materials combining silica or alumina with magnesium compounds and other inorganic materials. These composites provide enhanced surface area, improved surface chemistry, and increased capacity for aluminoxane support compared to standard silica alone, resolving the contradiction between support capacity and material complexity.
Solution Approach 2:
The patent utilizes porous support materials with controlled pore structures to increase the surface area available for aluminoxane support. The porous architecture allows higher loading of aluminum compound while maintaining structural integrity and accessibility, effectively increasing support capacity without proportionally increasing complexity.
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 new compositions yield highly active catalyst systems with increased aluminum loading and productivity, exceeding 200-400% compared to traditional supported methylaluminoxane systems.
Implementation Method 1
a support material in contact with an organoaluminum compound
Implementation Method 2
silica-supported methylaluminoxane
Data Source
AI summary
This invention provides activator precursor compositions and activator compositions. The activator precursor compositions are formed from a support material, an organoaluminum compound, and polyfunctional compounds having at least two aromatic groups in which at least two of said aromatic groups each has at least one polar moiety thereon. The activator compositions are formed from a support material, an organoaluminum compound, an aluminoxane, and a polyfunctional compound having at least two aromatic groups in which at least two of said aromatic groups each has at least one polar moiety thereon. Also provided are catalyst compositions, processes for forming catalyst compositions, and polymerization processes utilizing the catalyst compositions of this invention.