Resin Tire Elastomer Interface Viscosity Balance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Non-pneumatic tires with resin framework members face durability issues due to crack growth from stone chip damage and curbstone scraping, which worsens with improved elastomer dispersibility techniques that increase melt viscosity, leading to decreased productivity and strength.

Innovation Solution

A tire using a resin composition with a polyamide resin and an elastomer having a glass transition temperature of 25° C. or less, where the melt viscosity and average distance between elastomer interfaces satisfy the relationship ν < 34.369τ - 3.525, enhancing durability by balancing fluidity and dispersibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the dispersibility of the elastomer is improved by optimizing kneading conditions or improving the modification ratio, then the effect of suppressing crack growth increases, but the melt viscosity of the resin composition is remarkably increased

Engineering Contradiction:

ImprovedurabilityVSAvoidproductivity by injection molding

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent changes the chemical structure parameters of the elastomer by specifying a glass transition temperature of 25°C or less, which fundamentally alters the elastomer's properties to achieve low melt viscosity while maintaining good dispersibility and crack growth suppression effects

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the dispersibility of the elastomer is improved by optimizing kneading conditions or improving the modification ratio, then the effect of suppressing crack growth increases, but the resin composition is not sufficiently mixed at the junction (weld) of the resin composition flowing through the mold, leading to a decrease in strength

Engineering Contradiction:

ImprovedurabilityVSAvoidstrength of the framework member

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent specifies a glass transition temperature of 25°C or less for the elastomer, which changes the material parameters to ensure low melt viscosity. This enables sufficient mixing at junctions while maintaining good dispersibility for crack growth suppression, thus improving both strength and durability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite resin composition containing a polyamide resin and a specific elastomer with controlled glass transition temperature. This composite structure achieves synergistic effects where the elastomer suppresses crack growth while the low viscosity ensures proper mixing and welding, simultaneously improving durability and strength

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS11225108B2Tire

Publication Date: 2022.01.18 BRIDGESTONE CORP

AI summary

An object of the present disclosure is to provide a highly durable tire using a resin composition, and a solution to the problem is a tire obtained by using a resin composition containing a polyamide resin and an elastomer having a glass transition temperature of 25° C. or less, wherein the melt viscosity ν (Pa·sec) at 240° C. and the average distance between elastomer interfaces, τ (μm), satisfy the relationship of the following expression (1):ν<34.369τ−3.525 (1).