Winter Tyre Tread Mix Silica Silane Bonding Agent

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Solution Overview

Problem

Winter tire tread mixes face a challenge in achieving a balance between wet-pavement grip and performance on snow, as high silica content improves wet-pavement grip but impairs performance on ice and snow by making the tread mix too rigid.

Innovation Solution

A tread mix comprising a cross-linkable unsaturated-chain polymer base, 50 to 90 phr of silica with a surface area of 80 to 130 m^2/g, and 4 to 10 phr of a specific silane bonding agent, combined with 10 to 40 phr of BR with a vinyl content of 60 to 80%, using low-surface-area silica and a particular silane bonding agent to enhance grip and winter performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If silica content is increased to improve wet-pavement grip, then wet-pavement grip is improved, but performance on ice and snow deteriorates due to increased rigidity

Engineering Contradiction:
Improvewet-pavement gripVSAvoidperformance on ice and snow
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent changes the surface area parameter of silica from conventional high values (150-200 m²/g) to a specific range (70-120 m²/g), and adjusts the silane bonding agent content to 3-8 phr. This parameter optimization allows the tread mix to achieve both high wet-pavement grip and good winter performance by preventing excessive rigidity while maintaining strong adhesion.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite system combining silica, silane bonding agents, and unsaturated-chain polymer base in specific proportions. This composite approach allows the synergistic interaction between components to achieve both wet-pavement grip and winter performance, as the silane bonding agent mediates between silica particles and the polymer matrix to optimize both adhesion and flexibility.

Inventive Principle:
Principle #40Composite materials

2Strength

If silica content is increased to improve wet-pavement grip, then wet-pavement grip is improved, but the tread mix becomes too rigid

Engineering Contradiction:
Improvewet-pavement gripVSAvoidflexibility of tread mix
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent optimizes the surface area parameter of silica to 70-120 m²/g (lower than conventional high-silica mixes) and controls the silane bonding agent content at 3-8 phr. This parameter adjustment prevents excessive cross-linking and rigidity formation, maintaining the flexibility needed for winter conditions while achieving strong wet-pavement grip.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies silane bonding agents specifically to bond with silica silanol groups at localized sites, creating strong chemical bonds only where needed at the silica-polymer interface. This localized bonding approach prevents uniform rigidity throughout the entire tread mix, allowing flexible regions to maintain compliance on snow and ice while bonded regions provide strong wet-pavement adhesion.

Inventive Principle:
Principle #3Local quality

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 achieves excellent grip on both wet-pavement and winter conditions while maintaining good dry-pavement performance and wear index values, with mix F and G showing superior results when high-vinyl-content BR is used in conjunction with low-surface-area silica and the specified silane bonding agent.

Implementation Method 1

Silica is used in combination with silane bonding agents, which bond with silica silanol groups to prevent the formation of hydrogen bonds between silica particles, while at the same time fixing the silica chemically to the polymer base.

Methodology Applied
Scientific EffectSilane bonding: Chemical Bonding

Data Source

PatentEP2344349B1Winter tyre tread mix
Publication Date: 2012.09.05 BRIDGESTONE CORP

AI summary

A tread mix having a cross-linkable unsaturated-chain polymer base; 50 to 90 phr of silica with a surface area of 80 to 130 m2/g; and 4 to 10 phr of a silane bonding agent of formula (I) SH(CH2)3SiR1R2 2, where : R1 is -OCH2CH3, and R2 is -O(CH2CH2O)5(CH2)12CH3 .