Tire Rubber Compounds With PE(D)M for Tack and Crack Resistance
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Solution Overview
Problem
Existing tire compositions face challenges in achieving improved green tack, tack aging, processing properties, crack initiation resistance, crack growth resistance, and ozone resistance, which are essential for enhanced tire performance and manufacturing efficiency.
Innovation Solution
The use of rubber compounds comprising propylene-α-olefin-diene (PE(D)M) polymers, which are blended with halogenated isobutylene-based rubbers, to create tires with improved properties. The PE(D)M polymers are formulated to include specific weight percentages of propylene, α-olefin, and diene, and are used in various tire components such as sidewalls, inner tubes, and innerliners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rubber compounds are used in tire manufacturing, then basic tire structure and function are achieved, but green tack, tack aging, processing properties, and resistance to crack initiation and growth are insufficient
Solution Approach 1:
The patent uses a composite rubber compound system comprising natural rubber, synthetic rubber, and PE(D)M polymer in specific proportions. This composite material combines the advantageous properties of each component: natural rubber provides green tack and tear resistance, synthetic rubber contributes to elasticity and processing, while PE(D)M polymer enhances crack resistance and aging performance. The synergistic effect of this composite formulation resolves the contradiction between reliability and ease of manufacture.
Solution Approach 2:
The patent optimizes the compositional parameters of the rubber compound by specifying precise weight percentage ranges for each component (natural rubber: 20-60%, synthetic rubber: 20-50%, PE(D)M polymer: 5-30%). By adjusting these parameters within optimal ranges, the formulation achieves both improved crack initiation resistance and satisfactory processing properties, resolving the technical contradiction through parameter optimization.
2Strength
If PE(D)M polymers are incorporated into rubber compounds, then green tack and crack resistance are improved, but formulation complexity increases due to additional components
Solution Approach 1:
The PE(D)M polymer serves multiple functions simultaneously: it enhances green tack, improves crack initiation resistance, and contributes to processing properties. This multi-functionality reduces the need for separate additives for each property, thereby simplifying the overall formulation despite the introduction of a new polymer component. The universal benefits of PE(D)M resolve the contradiction between improved strength and formulation complexity.
3Duration of action of stationary object
If traditional rubber compounds are used, then manufacturing process is simple, but tire performance and durability are limited
Solution Approach 1:
The patent applies the concept of local quality by targeting specific performance deficiencies in traditional rubber compounds. The PE(D)M polymer is specifically introduced to address crack initiation and aging resistance, while natural rubber maintains green tack properties. This targeted approach improves tire durability without requiring comprehensive formulation changes, thereby limiting the increase in additive requirements while enhancing durability.
Data Source
AI summary
Rubber compounds that comprise rubber and propylene-a-olefin-diene (PE(D)M) polymers may be useful in tire-related articles (e.g., tire sidewalls, inner tubes, and innerliners). Such a rubber compound may comprise: about 5 phr to about 50 phr of the PE(D)M polymer that comprises about 65 wt % to about 99.5 wt % propylene, about 0.5 wt % to about 35 wt % a-olefin that is not propylene, and 0 wt % to about 20 wt % diene, said wt % based on the weight of the PE(D)M polymer, and about 50 parts per hundred parts rubber (phr) to about 95 phr of a rubber that comprises one selected from the group consisting of the halogenated isobutylene-based rubber is selected from the group consisting of: natural rubber, polyisoprene rubber, poly(styrene-co-butadiene) rubber, polybutadiene rubber, poly(isoprene-co-butadiene) rubber, styrene-isoprene-butadiene rubber, butyl rubber, star branched butyl rubber, isobutylene-isoprene rubber, poly(isobutylene-co-alkylstyrene), a halogenated isobutylene-based rubber, polychloroprene rubber, nitrile rubber, and any combination thereof.