Modified Conjugated Diene Polymer via Alumoxane Extraction
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Solution Overview
Problem
Existing methods for producing modified conjugated diene polymers struggle to achieve a balance between low heat build-up, excellent wear resistance, and reduced cold flow, often requiring high catalyst levels or resulting in insufficient mechanical properties.
Innovation Solution
A method involving a modification reaction with specific compounds, such as alkoxysilane and metal carboxylate, is used to introduce modifiers into conjugated diene polymers with high cis-1,4-bond content, optimizing the polymer's molecular structure and properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a catalyst system using methylalumoxane is used to obtain a conjugated diene polymer with high polymerization activity and narrow molecular weight distribution, then polymerization activity and molecular weight distribution are improved, but cold flow increases and storage stability deteriorates
Solution Approach 1:
The invention extracts and removes the harmful component (alumoxane) from the polymer system after it has served its catalytic function. By using a specific catalyst system that allows complete removal of alumoxane through extraction processes, the patent eliminates the source of cold flow while maintaining the benefits of high polymerization activity during production.
Solution Approach 2:
The invention performs preliminary action by selecting a catalyst system designed from the outset to enable complete alumoxane removal. The catalyst composition and polymerization conditions are optimized in advance to facilitate thorough extraction of alumoxane, preventing cold flow issues before they manifest in the final product.
2Power
If alumoxane is used to maintain sufficient catalytic activity during polymerization, then polymerization activity is improved, but the amount of metal remaining in the polymer increases and removal becomes necessary
Solution Approach 1:
The invention employs extraction processes to remove metal contaminants from the polymer. By using solvents and extraction methods that selectively remove metal ions while preserving the polymer structure, the patent reduces metal content to acceptable levels while maintaining high catalytic activity during the polymerization process.
Solution Approach 2:
The invention discards the alumoxane catalyst component after it has fulfilled its catalytic function by implementing thorough extraction and removal processes. The metal-containing alumoxane is separated from the polymer product, allowing the polymer to be obtained with minimal metal residue while the catalyst system maintains high activity during polymerization.
3Stability of the object's composition
If existing modification methods are used to reduce cold flow, then cold flow is reduced, but low heat build-up and wear resistance remain insufficient
Solution Approach 1:
The invention changes the fundamental parameter of cold flow reduction from chemical modification to physical removal of the catalyst. By completely removing alumoxane through extraction rather than adding modifying agents, the patent achieves cold flow reduction while preserving the original polymer's excellent wear resistance and low heat build-up characteristics.
Solution Approach 2:
The invention converts the harmful presence of alumoxane (which causes cold flow) into a benefit by using the alumoxane's role as a catalyst during polymerization to create high-cis polymers with inherent good properties, then removing the alumoxane afterward. This transforms the source of the problem into a means of achieving the desired polymer structure.
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 approach results in modified conjugated diene polymers with improved wear resistance, mechanical properties, and reduced cold flow, suitable for applications in tire rubber compositions.
Implementation Method 1
A conjugated diene polymer having a cis-1,4-bond content of 99.2% or more and having an active end is obtained by polymerizing a conjugated diene compound using a specific catalyst system
Implementation Method 2
carrying out a modification reaction that reacts a modifier with a conjugated diene polymer having a cis-1,4-bond content of 99.2% or more and having an active end to introduce the modifier into the active end of the conjugated diene polymer
Data Source
AI summary
A method for producing a modified conjugated diene polymer includes carrying out a modification reaction that reacts a modifier that includes a specific compound with a conjugated diene polymer having a cis-1,4-bond content of 98.5% or more and possessing an active end to introduce the modifier into the active end of the conjugated diene polymer to obtain a modified conjugated diene polymer. The modified conjugated diene polymer that exhibits excellent wear resistance, excellent mechanical properties, and reduced cold flow can be obtained by the method.