Reinforced EVA Rubber Composition for Thermo-Oxidation-Resistant Tires
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Solution Overview
Problem
Existing rubber compositions for tires are sensitive to thermal oxidation due to carbon-carbon double bonds in diene elastomers, leading to property changes and poor endurance, and replacing these with EVA copolymers results in compositions that are too rigid and unsuitable for pneumatic use when reinforced with fillers.
Innovation Solution
A rubber composition using EVA copolymers combined with inorganic reinforcing fillers, a specific coupling agent, and a crosslinking system maintains rigidity and resistance to deformation despite temperature changes, achieved by using a copolymer A with ethylene and vinyl acetate, copolymer B with alpha-olefin and functional monomers, and a peroxide crosslinking system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If diene elastomers with carbon-carbon double bonds are used in rubber compositions, then good elastomeric properties are achieved, but the composition becomes sensitive to thermo-oxidation leading to property changes and poor endurance
Solution Approach 1:
The patent changes the chemical structure parameter of the elastomer from diene-based (with double bonds) to EVA copolymer (with saturated backbone), fundamentally altering the material's resistance to thermo-oxidation while maintaining elastomeric properties through copolymer composition control
Solution Approach 2:
The patent creates a composite system combining EVA copolymer with inorganic reinforcing fillers (silica, carbon black) and organic fillers (paraffin, microcrystalline wax) to achieve both durability through filler reinforcement and resistance to thermo-oxidation through the saturated polymer matrix
2Stability of the object's composition
If EVA copolymers replace diene elastomers to improve thermo-oxidation resistance, then stability at high temperature is improved, but the composition becomes too rigid when reinforced with fillers making it unsuitable for pneumatic use
Solution Approach 1:
The patent adjusts the compositional parameters of the EVA copolymer (ethylene content, vinyl acetate content, molecular weight, branching) to optimize the balance between thermal stability and flexibility, ensuring the material remains suitable for pneumatic applications while resistant to thermo-oxidation
Solution Approach 2:
The patent develops a composite formulation combining EVA copolymer with specific ratios of inorganic fillers (silica, carbon black) and organic fillers (paraffin, microcrystalline wax) to maintain flexibility and processability while achieving thermal stability and reinforcement
3Duration of action of stationary object
If inorganic reinforcing fillers are added to EVA copolymer compositions to improve wear resistance, then tire durability is improved, but the composition becomes too rigid and unsuitable for pneumatic use
Solution Approach 1:
The patent creates a multi-component composite system combining EVA copolymer with inorganic fillers (silica, carbon black), organic fillers (paraffin, microcrystalline wax), and processing aids to achieve wear resistance through filler reinforcement while maintaining flexibility through the elastomeric matrix and plasticizing effects of organic components
Solution Approach 2:
The patent applies different types of fillers with different functions: inorganic fillers (silica, carbon black) provide structural reinforcement and wear resistance, while organic fillers (paraffin, microcrystalline wax) provide plasticization and flexibility, creating local functional zones within the composite
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 composition achieves stable mechanical properties and good reinforcement with minimal rigidity variation, maintaining resistance to deformation and reinforcement even under thermal stress.
Implementation Method 1
a crosslinking system with peroxides
Implementation Method 2
an inorganic reinforcing filler which is characterized by the presence of hydroxyl groups on its surface
Implementation Method 3
a copolymer based on at least one alpha-olefin monomer and at least one functional monomer Y, the functional monomer Y being chosen from monomers carrying an epoxide function and monomers carrying a carboxylic acid function
Data Source
AI summary
The invention relates to a rubber composition comprising at least: a copolymer A at a concentration greater than or equal to 50 phr, said copolymer A being a copolymer containing at least one ethylene monomer and at least one vinyl acetate monomer; an inorganic reinforcing filler; by way of a coupling agent between copolymer A and the inorganic reinforcing filler, a copolymer B different from copolymer A, said copolymer B being a copolymer containing at least one alpha-olefin monomer and at least one functional monomer Y; and a peroxide crosslinking system. Said composition is particularly suitable for use in the production of semi-finished products for tyres or in tyre production.