Magnesium-Titanium Catalyst High Temperature Polymerization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnesium-titanium catalysts used in olefin polymerization face deactivation at high temperatures, making it difficult to produce high activity 'leave-in' catalysts suitable for solution polymerization of thermoplastic polyolefins without causing quality issues such as polymer degradation.
Innovation Solution
A process involving the reaction of a diorganomagnesium compound with a controlled amount of active chlorine to form magnesium dichloride, followed by the addition of a tetravalent titanium chloride species, and subsequent washing to remove unreacted diorganomagnesium, results in a highly active magnesium-titanium procatalyst suitable for olefin polymerization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high polymerization temperatures are used for solution polymerization of thermoplastic polyolefins, then productivity is improved, but catalyst activity decreases due to deactivation
Solution Approach 1:
The patent modifies the catalyst composition parameters by using magnesium dichloride with specific chlorine content (1.55-1.90 equivalents per mole of magnesium) and controlling the magnesium-to-titanium ratio (5:1 to 10:1), enabling the catalyst to maintain high activity at elevated polymerization temperatures up to 250°C
Solution Approach 2:
The patent creates a composite catalyst system combining magnesium dichloride support with titanium chloride species and alkoxy/aryloxy ligands, forming a synergistic procatalyst that achieves both high temperature stability and high polymerization activity
2Productivity
If conventional magnesium-titanium catalysts are used, then catalyst activity is sufficient, but catalyst residues cause polymer quality problems and degradation
Solution Approach 1:
The patent removes harmful residues by optimizing the catalyst composition to minimize leftover metal species in the polymer, using controlled chlorine content (1.55-1.90 eq./mol Mg) and specific Mg:Ti ratios (5:1 to 10:1) to ensure complete reaction and reduce problematic catalyst residues
Solution Approach 2:
The patent changes the catalyst composition parameters including chlorine equivalents (1.55-1.90), magnesium-to-titanium ratio (5:1 to 10:1), and ligand types (alkoxy, aryloxy) to achieve high activity while minimizing harmful residues in the final polymer product
3Productivity
If very finely divided magnesium halide particles are used, then catalyst activity is improved, but manufacturing complexity increases
Solution Approach 1:
The patent controls particle size parameters by optimizing the reaction conditions including temperature (0-100°C), chlorine source addition rate, and magnesium compound concentration, producing finely divided particles with controlled surface area and morphology for 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 process enhances catalyst activity and reduces problematic residues, enabling the production of high-quality thermoplastic polyolefins with improved stability and performance at elevated temperatures.
Implementation Method 1
reacting a diorganomagnesium compound with a source of active chlorine to form magnesium dichloride
Implementation Method 2
collecting said solid product from step a) and separating said solid product from said diorganomagnesium which did not react in said step a)
Data Source
AI summary
A magnesium titanium olefin polymerization procatalyst is prepared by A) reacting a diorganomagnesium compound with a source of active chlorine, (with the proviso that the amount of chlorine is insufficient to completely convert the diorganomagnesium to magnesium dichloride); then B) removing unreacted diorganomagnesium from the reaction product; then depositing a tetravalent titanium species on the reaction product. This procatalyst is highly active for the solution polymerization of olefins when combined with a cocatalyst.