Tyre Rubber Composition Balancing Stiffness and Rolling Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Tire designers face the challenge of improving both rolling resistance and stiffness while maintaining low hysteresis, as increasing tread stiffness to enhance wear resistance often compromises rolling resistance properties.

Innovation Solution

A tire composition featuring a random copolymer with ethylene and conjugated diene units, combined with a polyfunctional acrylate derivative and peroxide, which balances rolling resistance, stiffness, and reinforcement without the need for reinforcing fillers, thereby reducing hysteresis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If tread stiffness is increased to improve wear resistance, then wear resistance is improved, but rolling resistance increases and hysteresis losses increase

Engineering Contradiction:

Improvewear resistanceVSAvoidrolling resistance

Core Design Contradiction:

StrengthVSLoss of energy

Solution Approach 1:

The invention changes the chemical composition parameters of the rubber compound by incorporating a specific polyfunctional acrylate derivative with 3 to 6 functional groups. This chemical parameter change enables the rubber matrix itself to provide reinforcement effects, achieving improved wear resistance without increasing tread stiffness through traditional means that would raise rolling resistance.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite rubber compound system combining diene elastomer, polyfunctional acrylate derivative, and peroxide. This composite material approach allows the acrylate derivative to function as both a crosslinking agent and a reinforcing agent, simultaneously improving wear resistance and maintaining low rolling resistance through synergistic material interactions.

Inventive Principle:

Principle #40Composite materials

2Strength

If tread stiffness is increased to improve wear resistance, then wear resistance is improved, but hysteresis losses increase

Engineering Contradiction:

Improvewear resistanceVSAvoidhysteresis losses

Core Design Contradiction:

StrengthVSLoss of energy

Solution Approach 1:

The invention modifies the molecular structure parameters of the rubber compound by introducing polyfunctional acrylate derivatives with high functionality (3-6 groups). This changes the crosslinking density and network structure parameters, enabling improved wear resistance through enhanced material cohesion without the stiffness increase that would elevate hysteresis losses.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The polyfunctional acrylate derivative acts as a molecular-level reinforcement that copies the load-bearing function of traditional filler particles. Instead of using macroscopic fillers that increase stiffness and hysteresis, the invention uses molecular crosslinks distributed throughout the rubber matrix to provide similar reinforcement effects without the adverse hysteresis impact.

Inventive Principle:

Principle #26Copying

3Stress or pressure

If reinforcing fillers are used to improve stiffness, then stiffness is improved, but rolling resistance increases

Engineering Contradiction:

ImprovestiffnessVSAvoidrolling resistance

Core Design Contradiction:

Stress or pressureVSLoss of energy

Solution Approach 1:

The invention extracts the reinforcing function from traditional filler particles and transfers it to the rubber matrix itself through polyfunctional crosslinking. By removing the need for reinforcing fillers and using the acrylate derivative to provide reinforcement through molecular crosslinks, the patent achieves improved stiffness without the rolling resistance penalty associated with filler incorporation.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical reinforcement system (filler particles physically supporting loads) with a chemical reinforcement system (molecular crosslinks providing structural integrity). The polyfunctional acrylate derivative creates a three-dimensional crosslinked network that provides stiffness through chemical bonds rather than physical filler support, thereby reducing rolling resistance.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 solution effectively enhances both rolling resistance and stiffness while minimizing hysteresis, improving the overall performance of tire materials without the use of reinforcing fillers, thus optimizing tire properties.

Implementation Method 1

a composition comprising a statistical copolymer comprising ethylene units and conjugated diene units, at least one peroxide, and at least one polyfunctional acrylate derivative

Methodology Applied

Scientific EffectPeroxide crosslinking: Chemical Bonding

Data Source

PatentEP3840962B1Tyre having a composition comprising an ethylene-rich elastomer, a peroxide and a specific acrylate derivative

Publication Date: 2023.10.04 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)

AI summary

The invention relates to a tyre having a rubber composition containing at least one elastomer matrix predominantly comprising a statistical copolymer comprising ethylene units and conjugated diene units, the molar fraction of the ethylene units in the copolymer being between 50% and 95%; a peroxide; and a specific polyfunctional acrylate derivative.