Tread Rubber Composition Balancing Wet Grip and Heat Buildup

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current tire technologies do not adequately address the need for improved wet grip performance during high-speed driving, despite advancements in highway infrastructure and vehicle performance.

Innovation Solution

A tire design featuring a tread portion with a rubber composition containing a polymer with an ethylene unit and a resin component with a cyclic structure, where the acetone-extractable content percentage is greater than or equal to 0.80 times the tread portion thickness, enhancing heat generation and adhesion on the tread surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silica is incorporated into tread rubber or low softening point resins are increased, then wet grip performance is improved, but heat generation increases and high-speed driving performance deteriorates

Engineering Contradiction:
Improvewet grip performanceVSAvoidheat generation
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The invention changes the chemical composition parameters of the tread rubber by incorporating specific polymers containing ethylene units (such as ethylene-propylene-diene copolymer) and cyclic resin components (such as coumarone-indene resin). This compositional parameter change allows the rubber to maintain lower temperature during high-speed driving while preserving wet grip performance, directly resolving the contradiction between wet grip improvement and heat generation reduction

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite rubber composition by combining multiple polymer components (natural rubber, polybutadiene, ethylene-containing polymers) with specific resin components (coumarone-indene resin, petroleum resin). This composite material approach synergistically improves wet grip performance while controlling heat generation, as the different components work together to achieve both objectives simultaneously

Inventive Principle:
Principle #40Composite materials

2Reliability

If more resin components are added to improve adhesion, then wet grip is enhanced, but the complexity of rubber composition increases

Engineering Contradiction:
Improvewet grip performanceVSAvoidrubber composition complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention optimizes the quantitative parameters of resin components by specifying precise proportion ranges (coumarone-indene resin: 1-10 parts by mass, petroleum resin: 1-20 parts by mass per 100 parts by mass of total rubber). This parameter optimization achieves effective wet grip performance while avoiding excessive composition complexity, as the controlled proportions ensure proper balance between adhesion and compositional simplicity

Inventive Principle:
Principle #35Parameter changes

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

This design significantly improves wet grip performance during high-speed driving by optimizing the migration and adhesion of components within the tread, leading to better traction and safety.

Implementation Method 1

enhancing heat generation and adhesion on the tread surface

Methodology Applied
Scientific EffectHeat generation: Viscous Heating

Implementation Method 2

enhancing heat generation and adhesion on the tread surface

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP4230438A1tire
Publication Date: 2023.08.23 SUMITOMO RUBBER INDUSTRIES LTD

AI summary

Provided is a tire having excellent wet grip performance during high-speed driving. The present invention relates to a tire which includes a tread portion including a rubber composition, the rubber composition containing a polymer containing an ethylene unit and a resin component containing a cyclic structure, the tire satisfying the following relationship (1): A/T ≥ 0.80, wherein A represents the acetone-extractable content (%) of the rubber composition, and T represents the thickness (mm) of the tread portion measured on the equator in a cross section taken in the radial direction of the tire.