Dynamically Vulcanized Alloys for Tire Inner Liners
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Solution Overview
Problem
Conventional dynamically vulcanized alloys (DVAs) used for tire inner liners face limitations in achieving sufficient impermeability, which is crucial for applications requiring flexibility, strength, and low permeability.
Innovation Solution
A DVA composition comprising a thermoplastic resin, a low-permeability elastomer with C4 to C7 isomonoolefin derived units, a nanofiller, and an ethylene copolymer resin, where the elastomer is dispersed as small particles in a continuous thermoplastic resin phase, enhancing the material's impermeability and mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional DVAs are used for tire inner liners, then flexibility and strength are achieved, but impermeability is insufficient
Solution Approach 1:
The patent creates a composite material system combining thermoplastic resin matrix, elastomer dispersed phase, nanofillers (montmorillonite clay), and ethylene copolymer resin. This multi-component composite achieves superior impermeability through the synergistic effect of the thermoplastic resin providing the continuous phase, elastomer providing flexibility, nanofillers creating tortuous diffusion paths, and ethylene copolymer enhancing barrier properties, thereby resolving the contradiction between achieving high reliability (impermeability) and maintaining ease of manufacture.
Solution Approach 2:
The patent applies local quality by dispersing elastomer as small particles (0.01-10 micrometers) throughout the thermoplastic resin matrix, creating regions with different properties: the continuous thermoplastic phase provides impermeability while the dispersed elastomer particles provide flexibility and toughness. This local differentiation allows the material to simultaneously achieve high impermeability and flexibility without compromising manufacturing ease.
2Reliability
If nanofiller is added to improve impermeability, then air barrier properties are enhanced, but processing complexity increases
Solution Approach 1:
The patent uses ethylene copolymer resin (5-30 phr) as an intermediary component that facilitates the integration of nanofillers into the thermoplastic resin matrix. The ethylene copolymer acts as a compatibilizer and processing aid, enabling uniform dispersion of nanofillers and elastomer particles while maintaining processability. This intermediary substance allows the system to achieve enhanced air barrier properties from nanofillers without proportionally increasing processing complexity.
Solution Approach 2:
The patent optimizes the amount of nanofiller and ethylene copolymer resin within specific ranges (nanofiller: sufficient to enhance barrier, ethylene copolymer: 5-30 phr) to achieve the desired air barrier properties while controlling processing complexity. By carefully controlling these parameters, the patent balances the improvement in impermeability against the increase in processing complexity, finding the optimal point where both requirements are satisfied.
3Strength
If elastomer is dispersed as small particles, then flexibility is maintained, but impermeability is reduced
Solution Approach 1:
The patent employs a composite material architecture where elastomer is dispersed as small particles (0.01-10 micrometers) in the thermoplastic resin matrix, combined with nanofillers and ethylene copolymer. The small elastomer particles provide flexibility and toughness, while the thermoplastic continuous phase and nanofiller network provide the impermeability barrier. This composite structure resolves the contradiction by distributing different functions to different components at different scales.
Solution Approach 2:
The patent applies local quality by creating a heterogeneous structure where elastomer particles are locally distributed throughout the thermoplastic matrix. The continuous thermoplastic phase maintains impermeability while the locally dispersed elastomer particles provide flexibility. This local differentiation of properties allows the material to simultaneously exhibit both high impermeability and flexibility, overcoming the trade-off between these two properties.
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 proposed DVA composition significantly improves air barrier properties, achieving a 70% reduction in air permeability when combined with a nanofiller and ethylene vinyl alcohol copolymer, making it suitable for thin-layer tire inner liners with enhanced flexibility and durability.
Implementation Method 1
The present invention is directed to a DVA/TPV composition comprising a thermoplastic resin, an elastomer, and a nanofiller... achieving a 70% reduction in air permeability when combined with a nanofiller and ethylene vinyl alcohol copolymer
Implementation Method 2
The elastomer is dispersed in the thermoplastic resin, providing flexibility to the material due to the elastomer... the elastomer is present as a dispersed phase of small particles in a continuous phase of the thermoplastic resin
Implementation Method 3
5 to 30 phr of an ethylene copolymer resin... achieving a 70% reduction in air permeability when combined with a nanofiller and ethylene vinyl alcohol copolymer
Implementation Method 4
The elastomer component is vulcanized during the melt mixing... The rubber is cured under conditions of dynamic vulcanization (curing the rubber during melt mixing as opposed to static curing that typically occurs in a rubber mold)
Data Source
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AI summary
This invention relates to the preparation of a dynamically vulcanized alloy comprising at least one elastomer, at least one thermoplastic resin, a nanofiller, and an ethylene copolymer resin.