Rubber Composition Balancing Scorch Time and Fast Vulcanization

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Solution Overview

Problem

Existing rubber compositions for tire inner liners face challenges in balancing sufficient scorch time with improved curing time while maintaining or enhancing breaking energy, impermeability to oxygen, and hysteresis performance.

Innovation Solution

A rubber composition based on an elastomer matrix, reinforcing filler, and crosslinking system, where the plasticizing agent includes a hydrocarbon resin with a tackifying resin content between 0.0 and 20 phr, and the crosslinking system contains a sulfur donor comprising N,N′-Caprolactam disulfide, optimizing the scorch time, curing time, breaking energy, impermeability, and hysteresis performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If conventional rubber compositions use traditional curing systems, then sufficient scorch time is secured, but curing time is prolonged

Engineering Contradiction:
Improvecuring timeVSAvoidscorch time
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The patent applies parameter changes by modifying the chemical composition and ratios of the crosslinking system components. Specifically, it uses a multi-component system including sulfur donor (0.5-5 phr), accelerator (0.1-2 phr), activator (0.1-5 phr), and crosslinking agent (0.1-5 phr), where each component's concentration is precisely controlled to achieve optimal balance between scorch safety and curing speed. This systematic parameter optimization resolves the contradiction by creating a coordinated chemical reaction sequence that prevents premature vulcanization while enabling rapid cure.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by combining multiple functional additives in a synergistic crosslinking system. The composition integrates sulfur donor, accelerator, activator, and crosslinking agent together with the elastomer matrix, creating a composite curing system where each component contributes specific functionality. This composite approach allows the system to maintain scorch safety through controlled activation while achieving fast curing through synergistic interaction among components.

Inventive Principle:
Principle #40Composite materials

2Strength

If traditional crosslinking systems are used, then processing is simplified, but breaking energy and impermeability performance are degraded

Engineering Contradiction:
Improvebreaking energyVSAvoidcomposition complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent uses composite materials by formulating a multi-component crosslinking system that integrates sulfur donor, accelerator, activator, and crosslinking agent in specific ratios. This composite chemical system creates enhanced breaking energy and impermeability performance through synergistic interactions, where each component contributes to the overall network structure and properties of the cured rubber.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by optimizing the distribution and concentration of each crosslinking component within the rubber composition. The specific phr ranges for each additive (sulfur donor: 0.5-5, accelerator: 0.1-2, activator: 0.1-5, crosslinking agent: 0.1-5) create localized chemical environments that promote uniform crosslinking density and network structure, thereby enhancing breaking energy and impermeability without excessive complexity.

Inventive Principle:
Principle #3Local quality

3Loss of energy

If conventional plasticizing agents are used, then processing ease is improved, but hysteresis performance and impermeability are worsened

Engineering Contradiction:
Improvehysteresis performanceVSAvoidprocessing ease
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by precisely controlling the amount of hydrocarbon resin (0.1-5 phr) and tackifying resin (0.01-1 phr) in the plasticizing agent system. This optimized composition reduces hysteresis losses and improves impermeability by modifying the polymer chain mobility and free volume, while the controlled concentrations ensure the mixture remains processable during manufacturing.

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

The composition achieves sufficient scorch time, reduced curing time, improved breaking energy, enhanced impermeability to oxygen, and better hysteresis performance, as demonstrated by comparative examples.

Implementation Method 1

the crosslinking system contains a sulfur donor comprising N,N′-Caprolactam disulfide

Methodology Applied
Scientific EffectSulfur crosslinking: Chemical Bonding

Implementation Method 2

the plasticizing agent includes a hydrocarbon resin with a tackifying resin content between 0.0 and 20 phr

Methodology Applied
Scientific EffectViscoelasticity: Viscoelasticity

Data Source

PatentUS20250019522A1A rubber composition
Publication Date: 2025.01.16 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)

AI summary

A rubber composition, which allows a sufficient scorch time while being maintaining or improving the curing time, the breaking energy performance, the performance of permeability to oxygen and the hysteresis performance, is based on at least an elastomer matrix, a reinforcing filler, a plasticizing agent and a crosslinking system. The plasticizing agent comprises a hydrocarbon resin comprising more than 0.0 phr and less than 20 phr of a tackfying resin, and the crosslinking system comprises a vulcanizing agent comprising more than 0.0 phr and less than 10 phr of a sulfur donor comprising N,N′-Caprolactam disulfide.