Fluorinated Organometallic Activating Supports for Metallocene Catalysts
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Solution Overview
Problem
Traditional supported metallocene catalyst systems for olefin polymerization face challenges such as high costs, instability, and poor polymer morphology, particularly in film applications, due to the use of activators like methyl aluminoxane and borates, which also result in issues with gel formation and rheological properties.
Innovation Solution
The development of novel activating supports based on fluorine-containing compounds and organometallic compounds, which are used to prepare supported catalyst systems by combining a fluorine-containing compound with an organometallic compound and a porous mineral oxide support, eliminating the need for fluorination steps involving hydrogen fluoride, and improving polymer rheology and extrudability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional activators like methyl aluminoxane and borates are used in supported metallocene catalyst systems, then catalyst activity is achieved, but cost increases and instability occurs
Solution Approach 1:
The patent extracts the activator function from separate chemical additives (methyl aluminoxane and borates) and integrates it into the support structure itself. The support is modified with fluorinated organometallic compounds that provide activating functionality, eliminating the need for separate activator components and thereby reducing cost and improving stability.
Solution Approach 2:
The patent merges the support structure and activator functions into a single integrated component. The fluorinated organometallic compounds are grafted onto the support surface, combining the structural role of the support with the activating role previously performed by separate chemicals, thus reducing system complexity and improving reliability.
2Productivity
If traditional activators are used in supported metallocene catalyst systems, then polymerization occurs, but poor polymer morphology and gel formation occur
Solution Approach 1:
The patent applies local quality modification by introducing fluorinated organometallic compounds at specific locations on the support surface. This creates localized activating sites with controlled distribution, leading to more uniform polymer growth and improved morphology while reducing gel formation associated with traditional activators.
3Ease of manufacture
If fluorination steps involving hydrogen fluoride are used to prepare activating supports, then activating supports are obtained, but process complexity and safety issues arise
Solution Approach 1:
The patent replaces the dangerous and complex hydrogen fluoride fluorination process with a milder, safer alternative using fluorinated organometallic compounds. This substitution eliminates the need for specialized equipment and safety infrastructure required for HF handling, simplifying the manufacturing process while maintaining effectiveness.
4Productivity
If traditional catalyst systems are used, then polymerization occurs, but rheological properties and extrudability are poor
Solution Approach 1:
The patent changes the chemical parameters of the activating system by using fluorinated organometallic compounds with specific molecular structures and electronic properties. This modification alters the interaction between the catalyst and monomer, leading to polymerization products with improved rheological properties and extrudability 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 new supported catalyst systems exhibit enhanced activity, improved rheological properties, and better bubble stability during film blowing, leading to more processable polymers with improved extrudability and stability, while also being more economically viable than traditional systems.
Implementation Method 1
combining (i) a fluorine-containing compound having a reactive group, and being of the formula R(Fn)-X wherein R is hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl with up to 20 non-hydrogen atoms, n is 1-41, X is OH, SH or NH2, and (ii) an organometallic compound selected from an alkylated derivative of aluminium or boron, (b) addition of a porous mineral oxide support material
Implementation Method 2
heating the functionalized support from step (b) under an inert gas and then under an atmosphere comprising oxygen
Data Source
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AI summary
Activating supports may be suitably prepared by (a) combining (i) fluorine-containing compounds having a reactive group and (ii) an organometallic compound, (b) addition of a porous mineral oxide support material, (c) heating the functionalized support from step (b) under an inert gas and then under an atmosphere comprising oxygen, and (d) recovering the activating support. The preferred fluorine-containing compounds have the formula: R(Fn) − X wherein R is hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl with up to 20 non-hydrogen atoms, n is 1 - 41, X is OH, SH or NR'2, R' is hydrogen or hydrocarbyl. The activating supports are suitable used in combination with transition metal catalysts for the polymerization of olefins. The supports are most preferably used in combination with metallocene complexes. The preparative route for the activating supports is easier and more economic than prior art methods and also provides for supported polymerization catalyst systems having excellent activities. Polymers produced by use of the activating supports exhibit improved rheology properties.