Fluororubber-Fluoropolymer Laminate for Direct Adhesion
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Solution Overview
Problem
Current rubber hoses for fuel transfer face challenges with fuel permeability, as increasing the thickness of the fluoropolymer barrier layer increases weight and reduces flexibility, and using perhalogen fluoropolymers complicates adhesion with rubber layers, leading to higher costs and productivity issues.
Innovation Solution
A laminate comprising a fluororubber layer and a fluoropolymer layer, where the fluororubber layer is made of a composition containing uncured fluororubber, silica particles with specific characteristics, and a basic multifunctional compound, enabling direct adhesion between fluororubber and fluoropolymer without additional processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the thickness of the fluoropolymer barrier layer is increased to decrease fuel permeability, then fuel-barrier properties are improved, but hose weight increases and energy conservation is compromised
Solution Approach 1:
The invention changes the chemical composition parameters of the fluoropolymer from conventional types to perfluoro(alkylvinylether)-containing copolymers, which provide superior fuel barrier properties at reduced thickness, thereby decreasing hose weight while maintaining reliability
2Reliability
If the thickness of the fluoropolymer barrier layer is increased to decrease fuel permeability, then fuel-barrier properties are improved, but hose bendability and flexibility are reduced
Solution Approach 1:
The invention changes the polymer composition to perfluoro(alkylvinylether)-containing copolymers with specific molecular structure parameters that provide high fuel barrier properties at thinner sections, thereby maintaining hose flexibility and bendability while achieving the required barrier performance
3Reliability
If a perhalogen fluoropolymer is used as a barrier layer to achieve low fuel permeability, then fuel-barrier properties are improved, but adhesion with rubber layers deteriorates
Solution Approach 1:
The invention introduces a specific copolymer composition containing perfluoro(alkylvinylether) units as an intermediary material that maintains the low fuel permeability of perhalogen fluoropolymers while providing improved adhesion to rubber layers, eliminating the need for additional surface treatment processes
4Reliability
If a perhalogen fluoropolymer is used as a barrier layer to achieve low fuel permeability, then fuel-barrier properties are improved, but manufacturing complexity and production cost increase
Solution Approach 1:
The invention uses perfluoro(alkylvinylether)-containing copolymers as an intermediary material that inherently provides both low fuel permeability and good adhesion properties, eliminating the need for additional surface treatment processes or film winding operations, thereby simplifying manufacturing and reducing costs
Data Source
AI summary
Adding silica particles having specified collective characteristics to a fluororubber formulation enhances direct adhesion between the fluororubber formulation and a copolymer upon curing. Specifically, as measured before being mixed into the fluororubber formulation, the silica particles have an average value of the product “(particle size)×(circularity)” that is 17.5 nm or higher and 500 μm or lower. The silica particles may also have an average particle size of between 25.0 nm inclusive and 500 μm inclusive, and an average circularity of 0.80 or higher. Alternatively, as measured after being incorporated into the fluororubber formulation and then cured, the silica particles have an apparent average value of the product “(particle size)×(circularity)” that is 32.0 nm or higher and 500 μm or lower. The silica particles may also have an apparent average particle size of between 40.0 nm inclusive and 500 μm inclusive as measured after being incorporated into the fluororubber formulation and then cured.