Multifunctional Vulcanizing Agent for Tire Rubber Durability
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Solution Overview
Problem
Existing rubber mixtures for tires face challenges in balancing abrasion and fatigue resistance, often requiring trade-offs that compromise other properties like heat build-up and rolling resistance.
Innovation Solution
A tire composition with a vulcanizing agent having a functionality greater than 4, which introduces additional crosslinking sites into the rubber matrix, enhancing tear energy and durability while maintaining other physical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional vulcanizing agents with functionality ≤4 are used, then the crosslinking density is limited, but improving abrasion and fatigue resistance requires higher crosslinking density which increases heat build-up and reduces rebound resilience
Solution Approach 1:
The patent changes the functionality parameter of the vulcanizing agent from conventional values (≤4) to greater than 4, allowing achievement of higher crosslinking density without the same negative effects on heat build-up and rebound resilience. This parameter change enables decoupling of the trade-off between durability and energy loss.
Solution Approach 2:
The patent uses a composite vulcanizing system combining a vulcanizing agent with functionality >4, sulfur, and accelerators. This composite approach creates a synergistic effect where the multifunctional agent provides the backbone for high crosslinking density while sulfur and accelerators optimize the vulcanization process, achieving improved abrasion and fatigue resistance without excessive heat build-up.
2Strength
If the crosslinking density is increased to improve tear energy and durability, then the network structure becomes more rigid, but this typically worsens rebound resilience and increases rolling resistance
Solution Approach 1:
The patent changes the crosslinking functionality parameter to >4, which allows formation of a more rigid network structure for improved tear energy and durability while the specific chemical nature of the multifunctional agent prevents excessive rigidity that would harm rebound resilience. This enables simultaneous improvement of strength and maintenance of 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 solution improves tire durability and wear resistance, decoupling the trade-offs between rolling resistance and durability, and maintaining other physical properties at similar levels.
Implementation Method 1
The crosslinks that the sulfur forms with the organic polymer are primarily polysulfide crosslinking points
Data Source
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AI summary
A tire composition, in particular for pneumatic tires, which has a shore-A hardness (DIN 53 505 and ASTM D2240) of at least 40 ShA and no more than 95 ShA and a glass transition temperature Tg (E" max) (DIN 53 513) of at least -80° C and no more than 0° C at a specific temperature sweep of -80° C to +80° C and at a specific compression of 10 + 0.2 percent at 10 Hz, is characterized by the following composition: - at least one vulcanizable diene rubber selected from among natural rubbers, synthetic polyisoprene rubbers, polyisobutylene rubbers, polybutadiene rubbers, and styrene-butadiene rubbers; 35 to 300 phr of at least one active filler selected from among blacks, silicas, silicon-based fillers, and metal oxides, at least 10 phr of said active fillers having to be blacks, silicas, or a combination thereof; - 0 to 250 phr of other or additional additives; - 0.1⋅10-3 to 42⋅10-3 mhr of a vulcanizing ingredient that is cross-linked with a functionality of more than 4; and - 0.1 to 20 phr of at least one vulcanization accelerator.