Diacid-Crosslinked Rubber Composition for Sulfur-Free Adhesion
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Solution Overview
Problem
Tire manufacturers face challenges in finding rubber compositions that eliminate sulfur while maintaining good adhesion to reinforcing cables, as existing solutions often require sulfurization, cobalt salts, or specific formulations that are not optimal.
Innovation Solution
A rubber composition based on elastomers with epoxy functions, a crosslinking system comprising polycarboxylic acid and imidazole, and a specific phenolic compound, which provides excellent adhesion to reinforcing elements without the need for vulcanization or sulfurization, and without using cobalt salts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sulfur-based crosslinking system is used, then adhesion to reinforcing cables is improved, but harmful factors increase due to sulfurization requirements and interphase evolution under humidity and temperature
Solution Approach 1:
The patent changes the chemical parameters of the crosslinking system by replacing sulfur-based crosslinking with a phenolic compound system. This substitution eliminates sulfurization and the associated harmful interphase evolution, while maintaining adhesion through phenolic-based crosslinking chemistry that is stable under humidity and temperature conditions.
Solution Approach 2:
The patent extracts and removes sulfur and cobalt salts from the rubber composition. By eliminating these substances, the harmful sulfurization process and interphase evolution are removed, while the desired adhesion function is achieved through alternative phenolic-based crosslinking mechanisms.
2Reliability
If sulfur and cobalt salts are used for adhesion, then adhesion function is improved, but device complexity and manufacturing constraints increase due to specific formulation requirements
Solution Approach 1:
The patent removes sulfur and cobalt salts from the formulation, eliminating the need for complex sulfurization processes and cobalt salt-based adhesion mechanisms. This simplification maintains adhesion functionality through phenolic compound crosslinking without the restrictive formulation requirements of traditional systems.
Solution Approach 2:
The patent changes the chemical composition parameters by substituting phenolic compounds for sulfur-cobalt systems. This parameter change simplifies the formulation by removing multiple constrained components (sulfur, cobalt salts, specific accelerators) while achieving adhesion through the phenolic crosslinking mechanism.
3Strength
If sulfur-based vulcanization is used, then crosslinking is achieved, but loss of substance occurs due to sulfur consumption and environmental concerns
Solution Approach 1:
The patent extracts sulfur from the crosslinking system and replaces it with phenolic compounds. This elimination of sulfur removes the associated substance loss and environmental issues, while phenolic-based crosslinking provides equivalent or superior network formation for achieving the desired strength and elasticity.
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 strong and durable adhesion to reinforcing elements, enhancing the performance of tire composites while eliminating the need for sulfur and cobalt salts, thus improving tire manufacturing processes.
Implementation Method 1
The composition according to the invention thus makes it possible to obtain excellent adhesion to the reinforcing elements requiring neither vulcanization or sulfurization, nor the presence of cobalt salts
Implementation Method 2
a crosslinking system comprising a polycarboxylic acid of general formula (I) in which A represents a covalent bond or a hydrocarbon group comprising at least 1 carbon atom, optionally substituted and optionally interrupted by one or more heteroatoms, an imidazole of general formula (II)
Data Source
AI summary
The invention relates to a rubber composition based on at least one elastomer comprising epoxide functions, a crosslinking system comprising a carboxylic polyacid and an imidazole and at least one phenolic compound substituted with at least one group selected from among carboxyl, hydrogencarbonyl and amino groups, or a radical selected from among carbonylalkyl, carboxylalkyl and aminoalkyl radicals.