Wet Rubber Masterbatch Two-Step Solidification Process

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Solution Overview

Problem

Existing methods for producing wet rubber masterbatches do not adequately optimize the balance between thermal and mechanical energy in the solidifying steps, resulting in suboptimal filler dispersibility and properties such as exothermic property and fatigue resistance in vulcanized rubber.

Innovation Solution

A two-step solidifying process is employed, where thermal energy is optimized in the first step by heating the filler-containing rubber latex solution, and mechanical energy is controlled through low-speed stirring, followed by the addition of an acid in the second step to further solidify the mixture, enhancing carbon black dispersibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single-step solidifying process is used, then the production process is simple, but the filler dispersibility is insufficient

Engineering Contradiction:
Improveprocess complexityVSAvoidfiller dispersibility
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The solidifying process is divided into two distinct steps: first solidification by heating and low-speed stirring, and second solidification by acid addition. This segmentation allows each step to optimize specific aspects of filler dispersibility, with the first step providing gentle thermal solidification and the second step providing chemical solidification, thereby achieving superior overall dispersibility compared to a single-step process.

Inventive Principle:
Principle #1Segmentation

2Productivity

If high-speed stirring is used during solidification, then the solidification speed is fast, but the filler dispersibility deteriorates

Engineering Contradiction:
Improvesolidification speedVSAvoidfiller dispersibility
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The stirring speed is dynamically controlled to be low during the first solidification step, adapting the mechanical energy input to the specific requirements of thermal solidification. This dynamic adjustment prevents excessive shear forces that would harm filler dispersibility while still maintaining adequate mixing, and the stirring parameters can be further adjusted in the second step based on process progression.

Inventive Principle:
Principle #15Dynamics

3Productivity

If excessive mechanical energy is applied during solidification, then the solidification efficiency is high, but the average molecular weight of rubber is lowered

Engineering Contradiction:
Improvesolidification efficiencyVSAvoidaverage molecular weight of rubber
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The process replaces excessive mechanical energy input with thermal energy input for the primary solidification mechanism. By using heating to induce solidification in the first step rather than relying on high-speed mechanical stirring, the method achieves solidification efficiency while minimizing mechanical shear forces that would degrade rubber molecular weight. The second step uses chemical solidification through acid addition, further reducing dependence on mechanical energy.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Device complexity

If the balance between thermal energy and mechanical energy is not optimized, then the process is simple, but the exothermic property and fatigue resistance are insufficient

Engineering Contradiction:
Improveenergy control complexityVSAvoidexothermic property and fatigue resistance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The process systematically changes and optimizes key parameters including heating temperature, heating time, and stirring speed to achieve the optimal balance between thermal and mechanical energy. By controlling these parameters in the first solidification step, and then adjusting them in the second step, the method achieves superior exothermic property and fatigue resistance in the vulcanized rubber, demonstrating how parameter optimization directly impacts final product performance.

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 process significantly improves the dispersibility and stability of fillers, leading to improved exothermic properties and fatigue resistance in the resulting vulcanized rubber, as well as enhanced storage stability of the masterbatch.

Implementation Method 1

stirring the yielded filler-containing rubber latex solution while heating the filler-containing rubber latex solution, thereby solidifying the filler-containing rubber latex solution

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

adding an acid in the second step to further solidify the mixture

Methodology Applied
Scientific EffectAcid solidification: Precipitation

Data Source

PatentUS10544289B2Process for producing wet rubber masterbatch
Publication Date: 2020.01.28 TOYO TIRE CORP

AI summary

A process for producing a wet rubber masterbatch comprises a step (I) of dispersing a filler into a dispersing solvent to produce a filler-containing slurry solution, and a step (II) of adding a rubber latex solution to the filler-containing slurry solution to yield a filler-containing rubber latex solution, and stirring the yielded filler-containing rubber latex solution while heating the filler-containing rubber latex solution, thereby solidifying the filler-containing rubber latex solution, and a step (III) of stirring the resultant while adding an acid thereto, thereby solidifying the filler-containing rubber latex solution. In the step (II), the circumferential speed of a stirring impeller which a mixing tank used at the time of the stirring has is less than 10 m/s, and a calorie of 25 to 250 J both inclusive per unit period and unit mass is given to the filler-containing rubber latex solution by the heating.