Modified Conjugated Diene Polymer for Tire Rubber
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional conjugated diene-based polymers for tires face challenges in maintaining storage stability and achieving optimal processability, tensile properties, and viscoelasticity while controlling molecular weight distribution and mooney viscosity over time.
Innovation Solution
A modified conjugated diene-based polymer is developed with a repeating unit derived from a conjugated diene-based monomer and a functional group from an aminoalkoxysilane-based modifier, which has a rate of change in molecular weight distribution of 10% or less, and includes a derived unit from a macromonomer for enhanced filler affinity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If batch type polymerization is used to improve physical properties through narrow molecular weight distribution, then manufacturing productivity is low and processability is deteriorated
Solution Approach 1:
The patent divides the polymerization process into two distinct stages: a first polymerization stage producing a base polymer with narrow molecular weight distribution for excellent physical properties, and a second polymerization stage producing a grafted polymer with broader distribution for improved processability. This segmentation allows each stage to optimize for its specific function, resolving the contradiction between physical properties and productivity.
Solution Approach 2:
The invention creates a composite polymer structure by grafting a second polymer onto the first polymer backbone. The base polymer provides the narrow molecular weight distribution for superior physical properties, while the grafted polymer chains contribute to broader overall distribution and enhanced processability, achieving both goals simultaneously.
2Productivity
If continuous type polymerization is used to improve productivity and processability, then molecular weight distribution becomes wide and physical properties are deteriorated
Solution Approach 1:
The patent segments the polymerization into two stages where the first stage (using continuous polymerization) ensures high productivity and establishes the base polymer structure, while the second stage (using batch polymerization) refines the molecular weight distribution by grafting additional chains, thereby recovering physical properties without sacrificing overall productivity.
Solution Approach 2:
The first polymerization stage performs preliminary action by creating the base polymer structure with appropriate molecular weight and narrow distribution. This preliminary structure serves as the foundation for the second stage, allowing the grafted polymer to enhance processability while maintaining the quality benefits of the initial narrow distribution.
3Use of energy by moving object
If vinyl content in SBR is increased to control glass transition temperature and reduce fuel consumption, then rotation resistance and braking force are improved, but storage stability may be affected
Solution Approach 1:
The patent optimizes the vinyl content parameter within a specific range (20-40%) to achieve the desired glass transition temperature for reduced fuel consumption. Additionally, it controls the ratio of grafted polymer to base polymer (5-50 wt%) to maintain storage stability, demonstrating parameter optimization to balance performance and stability.
Data Source
AI summary
The present invention relates to a modified conjugated diene-based polymer having excellent storage stability and excellent processability, tensile strength and viscoelasticity properties, and a rubber composition including the same, and provides a modified conjugated diene-based polymer including a repeating unit derived from a conjugated diene-based monomer; and a functional group derived from an aminoalkoxysilane-based modifier, wherein the rate of change of molecular weight distribution calculated by Mathematical Formula 1 is 10% or less, and a rubber composition including the same.