Pneumatic Tire Inner Liner Composite for Weight and Air Retention
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Solution Overview
Problem
Current pneumatic tires face challenges in achieving excellent air permeation resistance, crack resistance, and riding comfort while reducing rolling resistance, particularly in the context of weight-saving efforts.
Innovation Solution
A pneumatic tire design featuring an inner liner with a first layer containing styrene-isobutylene-styrene triblock copolymer and a second layer with styrene-isoprene-styrene or styrene-isobutylene diblock copolymer, optimized thickness ratios, and specific additives to enhance air permeation resistance and crack resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the inner liner is made thinner to reduce weight, then weight saving is achieved, but air permeation resistance deteriorates
Solution Approach 1:
The patent uses a composite material system consisting of a thermoplastic elastomer matrix combined with specific rubber components (natural rubber, isoprene rubber, and butyl rubber) to achieve both weight reduction and maintained air permeation resistance. The composite formulation allows the inner liner to be thinner while preserving functional performance.
Solution Approach 2:
The patent changes the chemical composition parameters of the inner liner material by specifying precise ranges of polymer components (styrene-isobutylene-styrene triblock copolymer, styrene-isoprene-styrene triblock copolymer, styrene-isobutylene diblock copolymer) and rubber components to optimize both weight and air permeation resistance properties.
2Reliability
If butyl-based rubber is used to improve air permeation resistance, then air permeation resistance is improved, but the inner liner thickness must be increased to 0.6-2.0 mm
Solution Approach 1:
The patent changes the material composition parameters by using a multi-component polymer system with specific thermoplastic elastomers combined with rubber components, allowing achievement of required air permeation resistance with reduced thickness compared to conventional butyl-based rubber formulations.
Solution Approach 2:
The patent employs a composite material system combining thermoplastic elastomer matrix with dispersed rubber components (natural rubber, isoprene rubber, butyl rubber) to achieve superior air permeation resistance at reduced thickness, overcoming the limitation of conventional single-material approaches.
3Weight of moving object
If the inner liner thickness is reduced for weight saving, then weight is reduced, but crack resistance deteriorates
Solution Approach 1:
The patent optimizes the compositional parameters by incorporating specific ratios of polymer components and rubber components, along with controlled amounts of sulfur and vulcanization accelerators, to enhance crack resistance while maintaining reduced thickness for weight savings.
Solution Approach 2:
The composite material system provides enhanced crack resistance through the synergistic combination of thermoplastic elastomer matrix and rubber component particles, which act as reinforcement and crack-arresting elements, allowing thinner construction without sacrificing durability.
4Device complexity
If a single-layer inner liner is used, then the structure is simple, but it cannot simultaneously achieve excellent air permeation resistance, crack resistance, and weight reduction
Solution Approach 1:
The patent segments the inner liner into distinct functional layers: a first layer containing styrene-isobutylene-styrene triblock copolymer with rubber components for air permeation resistance, and a second layer containing styrene-isoprene-styrene or styrene-isobutylene diblock copolymer with rubber components for crack resistance and adhesion, achieving multiple performance goals simultaneously.
Solution Approach 2:
The patent uses composite materials in a layered configuration where each layer has optimized composition for specific functions, combining the advantages of different polymer-rubber systems to achieve comprehensive performance improvement without excessive complexity.
Data Source
Figure 1
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AI summary
A pneumatic tire including an inner liner, the inner liner including a first layer including a first polymer composition having a polymer component containing not less than 5% by mass and not more than 70% by mass of an SIBS and not less than 30% by mass and not more than 95% by mass of a rubber component, and a second layer including a second polymer composition having a polymer component containing not less than 10% by mass and not more than 85% by mass of at least any of an SIS and an SIB and not less than 10% by mass and not more than 90% by mass of a rubber component, the first layer being placed inwardly in a tire radius direction, and the inner liner having an average thickness Gs in a buttress region Rs from a tire maximum width position to a position corresponding to a belt layer end Lu that is thinner than an average thickness Gb in a bead region Rb from the tire maximum width position to a bead toe.