Tread Rubber Composition for Tire Grip and Steering Stability

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Solution Overview

Problem

Existing tires face challenges in achieving both high dry grip performance and steering stability, particularly when the tan δ peak temperature is increased, leading to potential slippage and reduced contact area with the road surface.

Innovation Solution

A tire design comprising a tread part made of a rubber composition with styrene-butadiene rubber, carbon black filler, and a resin plasticizer, with specific parameters for radius of curvature and elastic modulus ratios to enhance heat generation and contact area, improving steering stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the tan δ peak temperature of tread rubber is increased to improve dry grip performance, then grip performance is improved, but the tread rubber becomes glassy and hardens at operational temperature, causing slippage and reducing contact area

Engineering Contradiction:
Improvedry grip performanceVSAvoidcontact area with road surface
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies parameter changes by precisely controlling the tan δ peak temperature within 70°C to 90°C and the 100°C tan δ value within 0.15 to 0.35, along with specific complex elastic modulus ranges. These parameter optimizations ensure the rubber maintains appropriate softness and contact area at operational temperatures while achieving high dry grip performance through controlled heat generation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by formulating a tread rubber composition containing styrene-butadiene rubber (SBR) as the base rubber, combined with specific fillers (carbon black, silica), plasticizers (polyester plasticizer, aromatic hydrocarbon oil), and curing agents. This composite formulation achieves both high tan δ peak temperature for grip and appropriate 100°C properties for contact area maintenance.

Inventive Principle:
Principle #40Composite materials

2Stability of the object's composition

If the complex elastic modulus is increased to improve steering stability, then steering stability is improved, but the contact area with road surface decreases

Engineering Contradiction:
Improvesteering stabilityVSAvoidcontact area with road surface
Core Design Contradiction:
Stability of the object's compositionVSArea of stationary object

Solution Approach 1:

The patent resolves this contradiction by precisely controlling the complex elastic modulus within 2.0 to 4.0 MPa at 100°C, which balances steering stability with adequate contact area. This parameter optimization ensures the tread rubber has sufficient stiffness for stable steering response while maintaining enough compliance for adequate road contact.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the radius of curvature of the tread part is optimized, then heat generation is promoted and grip performance is improved, but the structural design becomes more complex

Engineering Contradiction:
Improveheat generation and grip performanceVSAvoidtread structure design
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies curvature principles by optimizing the radius of curvature of the tread part within 50 mm to 220 mm. This curvature optimization promotes heat generation in the tread rubber during deformation, improving grip performance while maintaining a relatively simple overall tire structure that is easy to manufacture.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 design promotes heat generation in the tread rubber, increasing contact area with the road surface, thereby enhancing steering stability and grip performance.

Implementation Method 1

the tread part is composed of a rubber composition comprising a rubber component, a filler, and a plasticizer... 100°C tan δ represents a tan δ at 100°C of the rubber composition, and 100°C E* represents a complex elastic modulus, in MPa, at 100°C of the rubber composition

Methodology Applied
Scientific EffectViscoelastic heating: Viscoelasticity

Data Source

PatentEP4711150A1tire
Publication Date: 2026.03.18 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4711150A1 patent drawingFigure 1
  • EP4711150A1 patent drawingFigure 2
  • EP4711150A1 patent drawingFigure 3

AI summary

Provided is a tire comprising a tread part, wherein the tread part is composed of a rubber composition comprising a rubber component, a filler, and a plasticizer, wherein the rubber component comprises a styrene-butadiene rubber, wherein the filler comprises carbon black, wherein the plasticizer comprises a resin component, wherein a radius of curvature R of the tread part on a tire equator is 50 mm or more and 220 mm or less, and wherein Dt, 100°C tan δ, and 100°C E* satisfy the following inequality (1): 9.0×100°Ctanδ−1.0×103×100°CE*/Dt>0 where Dt represents a tire outer diameter, in mm, 100°C tan δ represents a tan δ at 100°C of the rubber composition, and 100°C E* represents a complex elastic modulus, in MPa, at 100°C of the rubber composition.