Silane-Bonded Silica Rubber Compounds for Tire Rolling Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The dispersion of silicon dioxide in rubber compounds for tires is challenging due to its hydrophilic nature and surface silanol groups, leading to agglomeration and poor compatibility with hydrophobic rubber, which limits the effectiveness of silicon dioxide in reducing rolling resistance without compromising mechanical properties.

Innovation Solution

A method involving a cross-linkable polymer base, a reactive reinforcing filler functionalized with polar groups, and a nucleophile agent, along with an intermediate mixing step using a silane bonding agent, to improve the dispersion and interaction of silicon dioxide within the rubber compound, allowing for reduced filler usage while maintaining mechanical properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If silicon dioxide is used as a reinforcing filler to reduce rolling resistance, then rolling resistance is improved, but dispersion of silicon dioxide in the rubber compound deteriorates due to agglomeration of particles

Engineering Contradiction:
Improverolling resistanceVSAvoiddispersion of silicon dioxide
Core Design Contradiction:
Loss of energyVSStability of the object's composition

Solution Approach 1:

The patent introduces silane bonding agents as intermediary substances that chemically bond to both the silicon dioxide particles and the rubber polymer. This mediator resolves the incompatibility between hydrophilic silicon dioxide and hydrophobic rubber, preventing agglomeration and improving dispersion while maintaining the rolling resistance benefits of silicon dioxide reinforcement.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the surface properties of silicon dioxide by treating it with silane bonding agents, changing its chemical and physical parameters. This treatment alters the surface energy and compatibility of silicon dioxide, enabling better dispersion in the rubber matrix without sacrificing the reinforcing effect that reduces rolling resistance.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If the quantity of reinforcing filler is reduced to improve rolling resistance, then rolling resistance is improved, but mechanical properties of the compound deteriorate

Engineering Contradiction:
Improverolling resistanceVSAvoidmechanical properties
Core Design Contradiction:
Loss of energyVSStrength

Solution Approach 1:

The patent changes the chemical parameters of the filler-rubber interface by introducing silane bonding agents. This creates strong chemical bonds between the filler and polymer, allowing the system to maintain mechanical strength with reduced filler content. The enhanced interfacial adhesion compensates for the lower filler quantity, preserving both mechanical properties and rolling resistance performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite system where silane bonding agents form a molecular bridge between silicon dioxide and rubber polymer. This composite structure at the interface level enhances the overall material performance, allowing reduced filler content while maintaining or improving both mechanical strength and rolling resistance characteristics.

Inventive Principle:
Principle #40Composite materials

3Reliability

If silicon dioxide is used to improve roadholding on wet surfaces, then roadholding is improved, but compatibility with hydrophobic rubber deteriorates due to hydrophilic characteristics

Engineering Contradiction:
Improveroadholding on wet surfacesVSAvoidcompatibility with rubber
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The silane bonding agent serves as a molecular intermediary that is compatible with both hydrophilic silicon dioxide and hydrophobic rubber. It forms chemical bonds with both materials, creating a bridge that resolves the incompatibility. This allows silicon dioxide to maintain its beneficial roadholding properties on wet surfaces while being properly integrated into the rubber compound matrix.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 method enhances the rolling resistance and stiffness of tire compounds while reducing the amount of silicon dioxide used, achieving improved performance without compromising mechanical properties.

Implementation Method 1

a dendrimer functionalized with polar groups adapted to interact with the reactive reinforcing filler

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 2

the use of silane bonding agents has been known for some time; these inhibit the formation of the above-mentioned hydrogen bonds bonding with the silanol groups and, at the same time, chemically bond the silicon dioxide to the polymer base

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 3

a subsequent mixing step in which the compound being prepared is mixed with a vulcanization system

Methodology Applied
Scientific EffectVulcanization: Chemical Bonding

Data Source

PatentUS9896568B2Rubber compounds containing silicon dioxide for the production of tyres
Publication Date: 2018.02.20 BRIDGESTONE CORP

AI summary

A method for preparing a rubber compound comprising at least one first mixing step in which at least part of a cross-linkable polymer base is mixed at least with a reactive reinforcing filler, a dendrimer functionalized with polar groups adapted to interact with the reactive reinforcing filler and a nucleophile agent; and a subsequent mixing step in which the compound being prepared is mixed with a vulcanization system.