Antidegradant Compounds for Rubber Fatigue Resistance
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Solution Overview
Problem
Current antidegradants for vulcanized rubber articles and elastomeric formulations face challenges in providing long-term protection against oxidative degradation, ozonative degradation, and mechanical fatigue, especially at lower concentrations and over extended periods, while maintaining compatibility with other additives and desirable characteristics.
Innovation Solution
Development of compounds represented by the formula I, which include substituted or unsubstituted alkyl, aryl, and alkylaryl groups, with specific bridging options, demonstrating antidegradant and antifatigue efficacies by inhibiting crack propagation and degradation in various applications, including tires and their components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If conventional antidegradants are used in vulcanized rubber articles, then some protection against degradation is provided, but the protection duration is insufficient for prolonged service periods
Solution Approach 1:
The patent divides the antidegradant protection into multiple functional components: primary antidegradants for initial protection, secondary antidegradants for sustained protection, and antifatigue agents for mechanical stress resistance. This segmented approach ensures continuous protection throughout the service life of the rubber article.
Solution Approach 2:
The patent modifies the chemical structure of antidegradant compounds by varying substituents (R1-R6 groups including alkyl, aryl, and heteroatom groups) to optimize protection duration and effectiveness. Different substituent patterns provide tailored protection profiles for extended service periods.
2Reliability
If higher concentrations of antidegradants are used to improve protection, then degradation resistance increases, but compatibility with other additives and desirable characteristics deteriorates
Solution Approach 1:
The patent assigns different functions to different additive components at different concentrations: primary antidegradants at lower concentrations provide initial protection, while secondary antidegradants and antifatigue agents at optimized concentrations provide sustained protection and mechanical stress resistance, respectively. This localized functional distribution maintains compatibility while achieving comprehensive protection.
3Strength
If existing antidegradant materials are used, then basic protection is achieved, but mechanical fatigue life and crack propagation resistance are insufficient
Solution Approach 1:
The patent combines antidegradant functionality with antifatigue functionality in a single compositional system. The formulation includes both antidegradant compounds (for chemical degradation protection) and antifatigue agents (for mechanical stress and crack propagation resistance), creating a unified protection system that addresses both chemical and mechanical failure modes.
4Duration of action of stationary object
If conventional elastomeric formulations are used, then basic performance is achieved, but protection against oxidative and ozonative degradation over extended periods is insufficient
Solution Approach 1:
The patent incorporates antidegradant compounds and antifatigue agents into the elastomeric formulation during the compounding stage, before vulcanization and service. This preliminary incorporation ensures that protection is present from the outset and continues throughout the service life, preventing degradation rather than merely responding to it.
Data Source
AI summary
A compound represented by the formula:wherein each R is independently selected from the group consisting of (i) substituted or unsubstituted alkyl with C=0 to 12 inclusive;wherein X1, X2, X3 and X4 are each independently selected from the group consisting of alkyl, aryl, alkylaryl groups and hydrogen;wherein R1, R2, R3, and R4 are each independently selected from the group consisting of alkyl, aryl, alkylaryl groups and hydrogen; and wherein one of R1 and R2 and one of R3 and R4 may optionally be bridged by a polymethylene group to form a cycloalkyl;wherein when C=0 in R, the combined group R1 R2 is the same as the combined group R3 R4; andwherein when C=1 in R, each of R1, R2, R3, and R4 are hydrogen.