Rubber Mixture Mixing Process Anti-Reversion Agent

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current rubber mixture production methods face challenges in achieving optimal physical and mechanical properties, such as rolling resistance and abrasion, while maintaining reduced vulcanization time without significant changes in network density, especially when using 1,6-bis(N,N-dibenzylthiocarbamoyldithio)hexane, which requires careful temperature management to prevent premature crosslinking.

Innovation Solution

A method involving a multi-stage mixing process where 1,6-bis(N,N-dibenzylthiocarbamoyldithio)hexane is added in the first mixing stage with silica and silanes, allowing for the use of anti-reversion agents at elevated temperatures without increasing mixture viscosity, followed by subsequent addition of vulcanization additives at lower temperatures to control crosslinking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If 1,6-bis(N,N-dibenzylthiocarbamoyldithio)hexane is added in the first mixing stage with elevated temperatures, then the mixture viscosity does not increase significantly and processing remains easy, but premature crosslinking may occur

Engineering Contradiction:
Improvemixture processingVSAvoidcrosslinking control
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The anti-reversion agent is added in the first mixing stage before the rubber mixture is fully prepared, performing preliminary protection against reversion during the mixing process. This preliminary action allows the agent to be distributed throughout the mixture before high-temperature processing begins, preventing premature crosslinking while maintaining processability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the temperature parameter during mixing, using elevated temperatures (140°C - 170°C) in the first mixing stage when the anti-reversion agent is present, then controlling temperature in subsequent stages. This parameter change allows easy processing without premature crosslinking by leveraging the thermal stability of the anti-reversion agent.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If crosslinking chemicals are added during high-temperature mixing, then the mixing process is simplified, but the crosslinking chemicals decompose due to temperature sensitivity

Engineering Contradiction:
Improvemixing processVSAvoidchemical stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The mixing process is segmented into multiple stages: first mixing stage with anti-reversion agent at elevated temperatures, and second mixing stage with crosslinking chemicals at controlled temperatures. This segmentation allows each stage to optimize for its specific requirements - high temperature for processing ease, then controlled temperature for chemical stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The anti-reversion agent is added in advance during the first mixing stage, performing preliminary protection before crosslinking chemicals are introduced. This preliminary action establishes a protective environment that allows subsequent addition of temperature-sensitive crosslinking chemicals without decomposition.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If a two-stage mixing process is used with cooling and storage, then crosslinking chemicals remain stable, but the production time increases

Engineering Contradiction:
Improvechemical stabilityVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The anti-reversion agent performs preliminary protection during the first mixing stage, eliminating the need for extended cooling and storage periods. This preliminary action stabilizes the mixture immediately, allowing direct progression to the second mixing stage without time-consuming intermediate storage.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent skips the traditional extended cooling and storage period between mixing stages by using the anti-reversion agent to maintain stability during continuous processing. This rushing through of the intermediate period reduces production time while maintaining chemical stability.

Inventive Principle:
Principle #21Skipping (Rushing through)

4Productivity

If the vulcanization time is reduced, then production efficiency increases, but the network density may change significantly

Engineering Contradiction:
Improveproduction efficiencyVSAvoidnetwork density
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent changes the vulcanization parameters by using the anti-reversion agent to control the crosslinking process. This allows reduced vulcanization time while maintaining network density through the stabilizing effect of the anti-reversion agent, which prevents reversion and ensures complete crosslinking even under accelerated conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The anti-reversion agent provides feedback control during vulcanization by continuously preventing reversion reactions. This feedback mechanism ensures that network density remains stable even when vulcanization time is reduced, as the agent compensates for the shorter processing time by preventing any back-reactions that would reduce crosslinking efficiency.

Inventive Principle:
Principle #23Feedback

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 approach enables significant reduction in vulcanization time, improves mechanical properties, and maintains network stability, leading to cost savings and enhanced production efficiency without compromising the quality of the rubber mixture.

Implementation Method 1

1,6-bis(N,N-dibenzylthiocarbamoyldithio)hexane, which is mixed in in the first mixing stage

Methodology Applied
Scientific EffectAnti-reversion:

Implementation Method 2

sulfur-containing organic silanes are used in the mixture production

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 3

couple it to the rubber matrix during vulcanization

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

one or more vulcanization additives

Methodology Applied
Scientific EffectVulcanization:

Implementation Method 5

crosslinking chemicals such as accelerators, peroxides and vulcanization resins

Methodology Applied
Scientific EffectCrosslinking:

Data Source

PatentEP2701926B1Method for producing rubber mixtures
Publication Date: 2015.08.12 LANXESS DEUTSCHLAND GMBH

AI summary

The invention relates to a method for producing rubber mixtures in a mixing process having, for example, several mixing steps, wherein the mixing steps can be divided into several sub-steps if applicable, comprising the mixing of the following components: one or more rubbers; one or more oxidic fillers containing hydroxyl groups; one or more organosilicon compounds containing sulfur and/or one or more hydroxypolysulfide compounds; one or more reversion protection agents, selected from 1,6-bis(N,N-dibenzylthiocarbamoyldithio)hexane (CAS number: 151900-44-6), 1,3-bis((3-methyl-2,5-dioxopyrrol-1-yl)methyl)benzene (CAS number: 119462-56-5), and hexamethylene-1,6-bis(thiosulfate), disodium salt, dihydrate (CAS number: 5719-73-3), individually or mixtures thereof, wherein said reversion protection agents are mixed in during the first mixing step; one or more vulcanization additives; and one or more rubber additives.