Tire Rubber Composition With Tg Matching for Snow-Wet Wear Balance

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Solution Overview

Problem

Existing tire rubber compositions struggle to achieve a highly balanced performance in snow, wet conditions, and wear resistance, which is increasingly demanded by modern tire requirements.

Innovation Solution

A rubber composition for tires is developed, comprising 100 parts by mass of a diene rubber with a styrene-butadiene copolymer and a butadiene copolymer, 30-100 parts by mass of a white filler, and 15-80 parts by mass of a thermoplastic resin, specifically blended to maintain a glass transition temperature difference of 10°C or less, enhancing snow, wet, and wear resistance performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If silica and resin components are blended in styrene-butadiene rubber with low glass transition temperature, then wet performance is improved, but snow performance and wear resistance performance are insufficient

Engineering Contradiction:
Improvewet performanceVSAvoidsnow performance
Core Design Contradiction:
ReliabilityVSReliability

Solution Approach 1:

The patent changes the glass transition temperature parameter of the styrene-butadiene copolymer to -55°C or lower, and precisely controls the thermoplastic resin glass transition temperature to within 10°C of the rubber's Tg. This parameter optimization resolves the contradiction by achieving both wet performance (through low Tg) and snow performance (through balanced Tg matching with thermoplastic resin)

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining diene rubber (specifically styrene-butadiene copolymer with low Tg), white filler (silica), and thermoplastic resin. The composite achieves synergistic effects where the rubber provides wet performance, the filler enhances snow performance, and the resin balance improves wear resistance, resolving the performance contradictions

Inventive Principle:
Principle #40Composite materials

2Reliability

If thermoplastic resin is added to improve wear resistance, then wear resistance performance increases, but snow performance may deteriorate

Engineering Contradiction:
Improvewear resistance performanceVSAvoidsnow performance
Core Design Contradiction:
ReliabilityVSReliability

Solution Approach 1:

The patent precisely controls the glass transition temperature of the thermoplastic resin to be within 10°C of the diene rubber's Tg. This Tg matching parameter ensures that the resin enhances wear resistance without compromising snow performance, as the compatible Tg range maintains rubber elasticity in cold conditions while providing wear protection

Inventive Principle:
Principle #35Parameter changes

3Reliability

If styrene-butadiene copolymer with very low glass transition temperature is used to improve wet performance, then wet performance increases, but low-temperature performance may decrease

Engineering Contradiction:
Improvewet performanceVSAvoidlow-temperature performance
Core Design Contradiction:
ReliabilityVSReliability

Solution Approach 1:

The patent creates a composite system where styrene-butadiene copolymer (Tg ≤ -55°C) is combined with thermoplastic resin having Tg within 10°C of the rubber's Tg. The resin component compensates for potential low-temperature performance loss while the low-Tg rubber maintains wet performance, resolving the contradiction through composite synergy

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the Tg parameter relationship between rubber and resin, ensuring the resin Tg is within 10°C of the rubber Tg. This parameter control allows the use of very low Tg rubber for wet performance while the matched resin prevents low-temperature performance deterioration

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

The rubber composition achieves improved snow performance, wet performance, and wear resistance in a highly balanced manner, suitable for use in winter and all-season tires, with specific physical properties optimizing tire performance across various conditions.

Implementation Method 1

a styrene-butadiene copolymer whose glass transition temperature is −55° C. or lower

Methodology Applied
Scientific EffectGlass transition temperature:

Implementation Method 2

satisfying a difference Tga-Tgm between Tga and Tgm of 10° C. or less, where Tga is a theoretical glass transition temperature of a mixture in which the diene rubber and the thermoplastic resin are blended

Methodology Applied
Scientific EffectGlass transition temperature:

Implementation Method 3

silica and various resin components are blended in a styrene-butadiene rubber

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 4

5 mass % or more of a butadiene copolymer

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentUS20250179276A1Tire rubber composition
Publication Date: 2025.06.05 THE YOKOHAMA RUBBER CO LTD

AI summary

To provide a rubber composition for a tire capable of achieving improved snow performance, wet performance and wear resistance performance in a highly balanced manner. For a rubber composition for a tire, containing: 100 parts by mass of a diene rubber containing 55 mass % or more of a styrene-butadiene copolymer whose glass transition temperature is −55° C. or lower and 5 mass % or more of a butadiene copolymer; 30 parts by mass or more and less than 100 parts by mass of a white filler; and 15 parts by mass or more and 80 parts by mass or less of a thermoplastic resin, a difference Tga−Tgm between Tga and Tgm is set to 10° C. or less, where Tga is a theoretical glass transition temperature of a mixture in which the diene rubber and the thermoplastic resin are blended at a mass ratio of 1:1.