Magnesium-Doped Silica Masterbatch for Rubber Dispersion

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Solution Overview

Problem

Inorganic fillers like silica tend to clump in elastomeric matrices, limiting their dispersion and reinforcing properties in tire treads, which affects wear resistance and processing difficulties, especially when high specific surface area is desired for improved reinforcement.

Innovation Solution

A method of preparing a silica/natural rubber masterbatch by doping silica with magnesium, dispersing it in water, mixing with natural rubber latex, and recovering the coagulum through filtering or centrifuging, without using coagulants or coupling agents, to achieve high filler dispersion and yield.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If silica filler is used to reinforce tire treads, then wear resistance is improved, but silica particles clump together forming aggregates that limit dispersion and reinforcing properties

Engineering Contradiction:
Improvewear resistanceVSAvoiddispersion uniformity
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary action by pre-treating silica particles with specific surface treatments and coupling agents before incorporation into the rubber matrix. This pre-treatment modifies the silica surface to reduce aggregation tendency and improve compatibility with the elastomeric matrix, thereby achieving better dispersion and reinforcing properties without the harmful clumping effect

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses coupling agents as intermediary substances that mediate between the inorganic silica filler and the organic elastomeric matrix. These coupling agents create a bridging interface that prevents silica particle aggregation and ensures uniform distribution throughout the matrix, resolving the contradiction between reinforcement and dispersion uniformity

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If high specific surface area silica is used to increase reinforcement, then reinforcing properties are improved, but processing difficulty increases due to higher viscosity

Engineering Contradiction:
Improvereinforcing propertiesVSAvoidprocessing difficulty
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by carefully controlling the specific surface area of silica within an optimized range and adjusting compounding parameters such as mixing temperature, shear rate, and additive composition. These parameter modifications allow high surface area silica to provide adequate reinforcement while maintaining processability by reducing viscosity and improving flow characteristics during manufacturing

Inventive Principle:
Principle #35Parameter changes

3Strength

If silica particles are incorporated into elastomeric matrix, then reinforcing properties are improved, but viscosity in uncured state increases making processing more difficult

Engineering Contradiction:
Improvereinforcing propertiesVSAvoidviscosity
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent employs lubricating agents and processing aids as intermediary substances that reduce friction and adhesion between silica particles and matrix during processing. These intermediaries lower the viscosity of the uncured compound, improving flow and processing ease while maintaining the reinforcing effect of silica in the final cured product

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies processing parameters such as temperature, mixing time, and shear conditions to optimize the balance between reinforcement and viscosity. By controlling these parameters, the patent achieves adequate dispersion and reinforcement while minimizing energy loss to viscosity during the compounding and processing stages

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 method achieves a high yield (>80 wt%) and good filler dispersion in the elastomeric matrix, enhancing the reinforcing properties of silica in tire treads while avoiding processing difficulties, particularly with highly dispersible silicas.

Implementation Method 1

doping the silica with magnesium

Methodology Applied
Scientific EffectSurface modification through doping: Adsorption

Implementation Method 2

preparing at least one dispersion of the resulting doped silica in water

Methodology Applied
Scientific EffectDispersion: Dispersion (of waves)

Implementation Method 3

bringing a natural rubber latex into contact with the aqueous doped-silica dispersion and mixing them together so as to obtain a coagulum

Methodology Applied
Scientific EffectCoagulation: Coagulation

Implementation Method 4

recovering the coagulum; and drying the recovered coagulum so as to obtain the masterbatch

Methodology Applied
Scientific EffectCentrifugal separation: Centrifugal Separation

Implementation Method 5

recovering the coagulum

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentUS9505890B2Method for preparing a masterbatch of natural rubber and magnesium-doped silica
Publication Date: 2016.11.29 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)

AI summary

Method for preparing a silica/natural rubber masterbatch, including: doping the silica with magnesium; preparing at least one dispersion of the resulting doped silica in water; bringing a natural rubber field latex into contact with the aqueous doped-silica dispersion and mixing them together so as to obtain a coagulum; recovering the coagulum; and drying the recovered coagulum so as to obtain the masterbatch.