Modified Diene Polymer with N/S Aromatic Units for Tire Rubber
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Solution Overview
Problem
Conventional conjugated diene-based polymers face challenges in achieving a balance between processability, productivity, and physical properties such as tensile strength and viscoelasticity, particularly in the context of tire rubber materials, where wide molecular weight distribution and low wet skid resistance are prevalent.
Innovation Solution
A modified conjugated diene-based polymer is developed, incorporating derived units from N-containing aromatic hydrocarbon and S-containing aromatic hydrocarbon or heterocycle compounds, with specific molecular weight distribution and sulfur content, prepared through a two-step polymerization process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If batch type polymerization is used to prepare SBR, then physical properties are improved, but productivity and processability deteriorate
Solution Approach 1:
The patent applies segmentation by dividing the polymerization process into two distinct stages: a first polymerization stage and a second polymerization stage. This allows the process to combine advantages of different approaches - the first stage operates under conditions optimized for physical properties while the second stage enhances productivity and processability, thus resolving the contradiction between these competing requirements.
Solution Approach 2:
The patent implements dynamics by making the polymerization process adaptable and adjustable through the two-stage approach. Process parameters such as temperature, monomer feed rates, and initiator addition can be dynamically optimized in each stage to achieve both high physical properties and productivity, rather than being constrained by fixed batch process conditions.
2Strength
If batch type polymerization is used to prepare SBR, then physical properties are improved, but processability deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the polymerization process into two distinct stages: a first polymerization stage and a second polymerization stage. This allows the process to combine advantages of different approaches - the first stage operates under conditions optimized for physical properties while the second stage enhances productivity and processability, thus resolving the contradiction between these competing requirements.
3Productivity
If continuous type polymerization is used to prepare SBR, then productivity and processability are improved, but physical properties deteriorate
Solution Approach 1:
The patent applies segmentation by dividing the polymerization process into two distinct stages: a first polymerization stage and a second polymerization stage. This allows the process to combine advantages of different approaches - the first stage operates under conditions optimized for physical properties while the second stage enhances productivity and processability, thus resolving the contradiction between these competing requirements.
Solution Approach 2:
The patent applies preliminary action by conducting the first polymerization stage under conditions optimized for physical properties before proceeding to the second stage. This preliminary optimization of polymer structure and properties in the first stage ensures that subsequent processing in the second stage can focus on productivity and processability without compromising the physical properties already established.
4Use of energy by moving object
If vinyl content in SBR is increased to control glass transition temperature, then fuel consumption is reduced, but wet skid resistance deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the vinyl content and styrene content as key parameters during the two-stage polymerization process. By optimizing these parameters in the first stage and adjusting them in the second stage, the patent achieves a balance where the glass transition temperature is controlled for low fuel consumption while maintaining adequate wet skid resistance through appropriate composition design.
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 modified polymer exhibits improved processability, tensile strength, and viscoelasticity, along with enhanced abrasion and rolling resistance, addressing the limitations of conventional polymers.
Implementation Method 1
The solution-polymerized SBR is prepared by using an anionic polymerization initiator
Implementation Method 2
U.S. Pat. No. 4,397,994 discloses a method of coupling active anions of the chain terminals of a polymer obtained by polymerizing styrene-butadiene using alkyllithium which is a monofunctional initiator in a non-polar solvent, using a coupling agent such as a tin compound
Data Source
AI summary
A modified conjugated diene-based polymer including a repeating unit from a conjugated diene-based monomer; a derived unit from an N-containing aromatic hydrocarbon compound; a derived unit from an S-containing aromatic hydrocarbon compound or an S-containing heterocycle compound, and Si. Each of Si content and N content is 50 ppm or more based on the total weight of the polymer. The modified conjugated diene-based polymer satisfies the following conditions: (i) molecular weight distribution (PDI; MWD): 1.0 or more and less than 3.0; and (ii) a S content is 25 ppm or more based on a total weight of the polymer.