Elastomeric Composition with Coarse Carbon Black for Low Rolling Resistance
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Solution Overview
Problem
Tires face a challenge in achieving a balance between low rigidity and hysteresis while maintaining sufficient reinforcement to withstand thermomechanical stresses, which affects rolling resistance and energy efficiency.
Innovation Solution
An elastomeric composition comprising at least 60 phr of natural rubber or synthetic polyisoprene, 10-30 phr of carbon black with specific surface area and oil absorption index, 10-30 phr of plasticizer, and a crosslinking system, specifically designed for the underlayer of a tire to achieve this balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional carbon black with high surface area is used to increase reinforcement, then thermomechanical resistance improves, but stiffness and hysteresis increase
Solution Approach 1:
The patent changes the physical parameters of carbon black by selecting coarse particles with low specific surface area (15-28 m²/g) and controlled oil absorption (20-60 ml/g), deviating from conventional fine carbon blacks. This parameter change reduces the carbon-black-elastomer interaction surface, thereby reducing hysteresis and rolling resistance while maintaining reinforcement through optimized composition ratios
Solution Approach 2:
The patent creates a composite material system combining coarse carbon black with specific elastomers (natural rubber and/or synthetic polyisoprene) and plasticizers in optimized ratios. This composite approach leverages the low hysteresis of natural rubber/polyisoprene combined with the reinforcement of coarse carbon black and the flexibility enhancement of plasticizers to achieve low rolling resistance with sufficient thermomechanical resistance
2Strength
If carbon black content is increased to improve reinforcement, then thermomechanical resistance improves, but hysteresis and rolling resistance worsen
Solution Approach 1:
The patent optimizes the carbon black particle size parameter to be coarse (low specific surface area), which reduces the total interfacial area between carbon black and elastomer matrix. This parameter optimization minimizes hysteresis losses while maintaining reinforcement efficiency through the specific surface area range of 15-28 m²/g
Solution Approach 2:
The patent applies local quality by using coarse carbon black particles that provide reinforcement at specific locations within the elastomer matrix without creating excessive hysteresis throughout the entire material. The coarse particles act as discrete reinforcement points rather than a continuous fine network, reducing energy loss
3Use of energy by moving object
If fine carbon black is used to reduce hysteresis, then rolling resistance improves, but reinforcement and thermomechanical resistance worsen
Solution Approach 1:
The patent employs a composite material strategy combining coarse carbon black with plasticizers and specific elastomers to compensate for the lower reinforcement efficiency of coarse particles. The plasticizer content (at least 10 parts per 100 parts elastomer) and selected elastomer types enhance the matrix flexibility and load-bearing capacity, allowing coarse carbon black to provide sufficient reinforcement without requiring high surface area
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 composition effectively reduces rolling resistance and hysteresis while maintaining necessary reinforcement, leading to improved energy efficiency and thermomechanical resistance.
Implementation Method 1
10 to 30 parts of a carbon black having a specific surface area BET ranging from 15 to 28 m2/g and a COAN index ranging from 20 to 60 ml/g
Implementation Method 2
at least 10 parts of at least one plasticizer
Implementation Method 3
a crosslinking system
Data Source
Figure 1
Figure 2
AI summary
The present invention relates to an elastomeric composition comprising a) an elastomeric matrix comprising at least 60 phr of at least one elastomer chosen from natural rubber and synthetic polyisoprenes, b) 10 to 30 phr of a carbon black having a BET specific surface area varying from 15 to 28 m2/g and a COAN index varying from 20 to 60 ml/g, c) at least 10 phr of at least one plasticizer, and d) a crosslinking system.