Rubber Composition Mixing Sequence for Wet Grip
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing rubber compositions used in pneumatic tires, particularly those with high styrene-butadiene rubber content, face challenges in balancing wet grip performance, low temperature performance, abrasion resistance, and low heat generation (rolling resistance) due to the compatibility of syndiotactic-1,2-polybutadiene (SPB) with silica, which hinders the effective exhibition of SPB's performance.
Innovation Solution
A method involving the initial kneading of diene rubber with silica, followed by the addition and kneading of SPB, to accelerate phase separation and enhance the wet grip performance while maintaining low temperature and abrasion resistance, involves adding 20 parts by mass or more of silica to 100 parts by mass of diene rubber and then adding 3 to 20 parts by mass of SPB to the kneaded mixture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If syndiotactic-1,2-polybutadiene (SPB) is added to diene rubber together with silica or after silica addition, then processability and low rolling resistance are improved, but wet grip performance deteriorates due to compatibility between SPB and silica
Solution Approach 1:
The patent divides the mixing process into two distinct stages: first mixing diene rubber with silica to form a master batch, then separately adding SPB in a second mixing stage. This segmentation prevents SPB from directly contacting and interacting with silica, thereby avoiding the compatibility issue that would otherwise reduce wet grip performance while still achieving improved processability and low rolling resistance.
Solution Approach 2:
The patent performs preliminary mixing of diene rubber with silica to create a master batch before adding SPB. This preliminary action ensures that silica is already uniformly distributed in the diene rubber matrix, and when SPB is subsequently added, it does not directly interact with silica particles, thus preserving the ice controlling action and wet grip performance while still achieving the desired processability improvements.
2Reliability
If high styrene content is used in styrene-butadiene rubber to improve wet grip performance, then grip performance on wet road surface is improved, but low temperature performance, abrasion resistance, and low heat generation performance deteriorate
Solution Approach 1:
The patent creates a composite rubber composition by combining diene rubber (such as SBR with optimized styrene content) with syndiotactic-1,2-polybutadiene (SPB) as a functional additive. This composite approach allows the base diene rubber to provide good wet grip performance while SPB contributes ice controlling action and maintains low temperature flexibility, thereby achieving a balance among wet grip performance, low temperature performance, abrasion resistance, and low heat generation performance without requiring excessively high styrene content.
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
This approach effectively brings out the performance of SPB, improving wet grip performance and maintaining low temperature and abrasion resistance, while suppressing the deterioration of low heat generation performance, by controlling the mixing and phase separation of silica and SPB within the rubber composition.
Implementation Method 1
kneading 20 parts by mass or more of silica with 100 parts by mass of diene rubber
Implementation Method 2
adding from 3 to 20 parts by mass of syndiotactic-1,2-polybutadiene to the kneaded mixture obtained, followed by kneading... to accelerate phase separation
Data Source
AI summary
A method for producing a rubber composition, which comprises kneading 20 parts by mass or more of silica with 100 parts by mass of diene rubber, and adding from 3 to 20 parts by mass of syndiotactic-1,2-polybutadiene to the kneaded mixture obtained, followed by kneading is disclosed. This method brings out characteristics of syndiotactic-1,2-polybutadiene and can improve wet grip performance.