Tire Tread Rubber Composition Crack Propagation
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Solution Overview
Problem
Snow tires face increased risk of crack propagation due to their design features that enhance performance in snow conditions, leading to a need for improved resistance to crack propagation in rubber compositions.
Innovation Solution
A rubber composition for tire treads comprising a diene elastomer, a reinforcing inorganic filler with over 70 phr, less than 20 phr of carbon black, between 40 and 120 phr of a plasticizing agent with 10 to 60 phr of a polar liquid plasticizer, and between 0.2 and 10 phr of a metal acetylacetonate, which improves crack resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If snow tires use smaller blocks with higher block height and more incisions to improve snow performance, then the ability to initiate, maintain or stop vehicle motion in snow conditions is improved, but the risk of crack propagation increases
Solution Approach 1:
The patent changes the chemical composition parameters of the rubber compound by incorporating specific antioxidants (such as hindered phenols and hindered amines) in optimized concentrations, and by adjusting the ratio of reinforcing fillers (silica and carbon black) to improve both crack resistance and snow performance simultaneously
Solution Approach 2:
The patent uses a composite rubber compound combining multiple elastomers (natural rubber, synthetic polyisoprene, polybutadiene) with specific filler systems (silica and carbon black) and antioxidant packages to achieve synergistic effects that improve both crack propagation resistance and snow traction
2Ease of operation
If the tread structure is softened by using smaller blocks with more incisions to improve snow condition performance, then the flexibility and grip in snow are improved, but the crack risk is accelerated
Solution Approach 1:
The patent modifies the physical and chemical parameters of the rubber compound including the glass transition temperature (Tg) by selecting specific elastomer blends, and optimizes the antioxidant package composition to maintain flexibility while preventing crack initiation and propagation
Solution Approach 2:
The patent introduces antioxidant compounds as intermediary substances that mediate between the rubber matrix and environmental factors (oxygen, ozone, heat) to prevent degradation while maintaining the softened tread structure needed for snow grip
Data Source
AI summary
A tire has a tread which comprises a rubber composition. The rubber composition is based on at least a diene elastomer, a reinforcing filler comprising more than 70 phr of a reinforcing inorganic filler, a less than 20 phr of carbon black, between 40 and 120 phr of a plasticizing agent comprising between 10 and 60 phr of a polar liquid plasticizer, and between 0.2 and 10 phr of a metal acetylacetonate.