Imidazole-Functional Dipolar Additive for Rubber Curing Stiffness
Solution Overview
Problem
Existing rubber compositions for tire treads face challenges in achieving a balance between cured rigidity and hysteresis, with solutions like increasing loading rates or introducing styrene-butadiene copolymers often increasing hysteresis, and methods to enhance rigidity, such as using glycerol, may not adequately address both properties simultaneously.
Innovation Solution
Incorporating a 1,3-dipolar compound, specifically a compound with an imidazole ring, into a diene rubber composition reinforced with a filler, which involves adding the 1,3-dipolar compound and a reinforcing filler during a thermomechanical kneading process, followed by cooling and incorporating a crosslinking system, to create a rubber composition with improved cured rigidity and reduced hysteresis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If filler content is increased or styrene-butadiene copolymers with high styrene content are introduced to increase curing stiffness, then the curing stiffness of the rubber compound is improved, but the hysteresis of the rubber compound increases
Solution Approach 1:
The patent introduces a novel compound with specific molecular structure (formula I) containing an imidazole ring and dipole group, changing the chemical composition parameters of the rubber compound. This specific compound provides curing stiffness enhancement while maintaining low hysteresis, resolving the trade-off between strength and energy loss
Solution Approach 2:
The patent creates a composite rubber compound by combining diene elastomer with the specific compound of formula (I) and reinforcing fillers. This composite approach allows the unique molecular structure of the compound to interact with the elastomer matrix, achieving both high curing stiffness and low hysteresis simultaneously
2Loss of energy
If low-hysteresis compounds are used to reduce hysteresis, then the hysteresis of the rubber compound is improved, but the curing stiffness becomes low
Solution Approach 1:
The patent modifies the chemical composition by introducing the compound of formula (I) with specific functional groups (imidazole ring and dipole). This parameter change enables the rubber compound to achieve low hysteresis while simultaneously providing sufficient curing stiffness, reversing the traditional trade-off
3Strength
If glycerol is introduced to increase the curing stiffness of a low-hysteresis rubber compound, then the curing stiffness is improved, but the hysteresis may increase
Solution Approach 1:
The patent replaces glycerol (a conventional additive) with a specifically designed compound of formula (I) that has superior performance characteristics. This new compound provides more effective and durable curing stiffness enhancement without the hysteresis penalty associated with glycerol
Solution Approach 2:
The patent changes the chemical identity of the curing stiffness enhancer from glycerol to the compound of formula (I). This parameter change results in a material that provides both curing stiffness and low hysteresis, overcoming the limitations of glycerol-based formulations
Data Source
AI summary
The invention relates to a rubber composition based on at least one diene elastomer, a reinforcing filler, and a 1,3-dipolar compound having an imidazole function. Such a composition has an improved compromise of the properties of post-cure rigidity and hysteresis.