Inner Liner Rubber Composition for Tire Crack Resistance
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Solution Overview
Problem
Tires with reduced heat generation on the inner liner face challenges in absorbing impact, leading to potential cracks and deterioration of air retention properties, which affects recyclability and performance.
Innovation Solution
A tire design with an inner liner formed from a rubber composition that maintains a specific relationship between elongation at break and loss tangent, along with a predetermined distance from the tread crown to the tire inner cavity surface, enhancing crack resistance and fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If heat generation on the inner liner is reduced to improve fuel efficiency, then fuel efficiency is improved, but the inner liner cannot absorb impact applied to the tire, leading to crack occurrence and deterioration of air retention properties
Solution Approach 1:
The patent applies parameter changes by precisely controlling the distance G from the crown part of the tread to the tire inner cavity surface within 8.0 mm to 9.5 mm, and by controlling the relationship between elongation at break and loss tangent of the inner liner rubber composition. This optimization allows the inner liner to have reduced heat generation while maintaining sufficient impact absorption capability, thereby resolving the contradiction between fuel efficiency and air retention properties.
2Productivity
If the inner liner is designed with reduced heat generation, then fuel efficiency is improved, but crack resistance deteriorates due to inability to absorb impact during long-term running
Solution Approach 1:
The patent optimizes specific parameters including the distance G (8.0-9.5 mm) from the crown part of the tread to the tire inner cavity surface, and the relationship between elongation at break and loss tangent of the inner liner rubber composition. These parameter changes enable the inner liner to achieve reduced heat generation while maintaining crack resistance through controlled strain distribution and impact absorption.
3Strength
If elongation at break of the inner liner is increased to improve crack resistance, then crack resistance is improved, but heat generation on the inner liner increases, reducing fuel efficiency
Solution Approach 1:
The patent resolves this contradiction by optimizing the relationship between elongation at break and loss tangent of the inner liner rubber composition, rather than simply increasing elongation at break. By controlling this relationship alongside the distance G parameter, the inner liner achieves sufficient crack resistance while minimizing heat generation and maximizing fuel efficiency.
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 tire exhibits improved crack resistance and fuel efficiency by securing sufficient elongation at high temperatures while minimizing strain on the inner liner, effectively preventing cracks and maintaining air retention.
Implementation Method 1
an elongation at break of the rubber composition measured under a condition of a temperature at 80°C and a tension rate of 3.3 mm/sec (80°CEB), a loss tangent tang δ of the rubber composition measured under a condition of a temperature at 70°C, a frequency of 10 Hz, an initial strain of 10%, and a dynamic strain of ± 2.5% (70°C tan δ)
Implementation Method 2
a loss tangent tang δ of the rubber composition measured under a condition of a temperature at 70°C, a frequency of 10 Hz, an initial strain of 10%, and a dynamic strain of ± 2.5% (70°C tan δ)
Data Source
Figure 1
AI summary
An object of the present invention is to provide a tire having improved crack resistance. Provided is a tire comprising a tread and an inner liner, wherein the inner liner is formed of a rubber composition comprising a polymer component, wherein a distance G from a crown part of the tread to a tire inner cavity surface is 9.0 mm or less, wherein an elongation at break of the rubber composition measured under a condition of a temperature at 80°C and a tension rate of 3.3 mm/sec (80°CEB), a loss tangent tang δ of the rubber composition measured under a condition of a temperature at 70°C, a frequency of 10 Hz, an initial strain of 10%, and a dynamic strain of ± 2.5% (70°C tan δ), and G (mm) satisfy inequalities (1) and (2) described below. 80°CEB/70°Ctanδ≥2600 80°CEB/G≥40