Catalyst System for UHMWPE Bulk Density and Activity
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Solution Overview
Problem
The production of ultra high molecular weight polyethylene (UHMWPE) requires a catalyst system that achieves high powder bulk density, narrow particle size distribution, and high catalyst activity, while minimizing catalyst residues and costs.
Innovation Solution
A catalyst system comprising a solid reaction product of a hydrocarbon solution containing organic oxygen containing magnesium and titanium compounds, combined with a mixture of metal and silicon compounds, and an organoaluminium compound, where the molar ratio of metal to titanium is less than 1:1, and post-treated with an aluminium compound, resulting in a catalyst with high activity and desired polymer properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the average particle size of UHMWPE powder is reduced below 250 μm, then the bulk density and processability are improved, but the catalyst activity requirements become more severe and catalyst costs increase
Solution Approach 1:
The patent changes the chemical composition parameters of the catalyst system by incorporating specific metal compounds (MeRnX3-n where Me is Group III metal) and silicon compounds (RmSiCl4-m) in controlled molar ratios, along with organoaluminium compounds, to optimize catalyst activity while maintaining small particle size and high bulk density
Solution Approach 2:
The patent creates a composite catalyst system combining multiple components: metal compounds of Group III metals, silicon compounds, organoaluminium compounds, and their reaction products, where each component contributes specific properties to achieve the desired balance of particle size, bulk density, and catalyst activity
2Length of moving object
If the catalyst yield is reduced to produce small polymer particles, then the average particle size is reduced below 250 μm, but the catalyst residues in polymer increase and catalyst costs increase
Solution Approach 1:
The patent optimizes the molar ratios of catalyst components, specifically controlling the ratio of metal from (b) to titanium from (a) to be less than 1:1, and adjusting organoaluminium compound quantities to achieve high catalyst activity that enables small particle production with minimal catalyst residues and reduced catalyst costs
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 catalyst system produces UHMWPE with high bulk density, narrow particle size distribution, and low catalyst residues, facilitating efficient processing and reducing production costs.
Implementation Method 1
a catalyst system comprising I. the solid reaction product obtained by reaction of: (a) a hydrocarbon solution comprising (1) an organic oxygen containing magnesium compound or a halogen containing magnesium compound and (2) an organic oxygen containing titanium compound and (b) a mixture comprising a metal compound having the formula MeRnX3-n... II. an organoaluminium compound
Data Source
AI summary
The invention relates to a catalyst system comprisingI. a solid reaction product obtained by reaction of:(a) a hydrocarbon solution comprising(1) an organic oxygen containing magnesium compound or a halogen containing magnesium compound and(2) an organic oxygen containing titanium compound and(b) a mixture comprising a metal compound having the formula MeRnX3-n wherein X is a halogenide, Me is a metal of Group III of Mendeleev's Periodic System of Chemical Elements, R is a hydrocarbon radical containing 1-10 carbon atoms and 0≦n≦3 and a silicon compound of formula RmSiCl4-m wherein 0≦m≦2 and R is a hydrocarbon radical containing 1-10 carbon atoms wherein the molar ratio of metal from (b): titanium from (a) is lower then 1:1 andII. an organoaluminium compound having the formula AlR3 in which R is a hydrocarbon radical containing 1-10 carbon atoms.