One-Pack Adhesive for Fuel Cell Separators
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Solution Overview
Problem
Current adhesives for bonding fuel cell separators lack high-temperature durability, resistance to moist heat, rapid curability, and purity, leading to potential gas leaks and reduced fuel cell lifespan due to contamination and inadequate assembly efficiency.
Innovation Solution
A one-part adhesive comprising epoxy resin, amine-type curing agent, capsule-type curing accelerator, flaky inorganic filler, and polycarbodiimide compound, which provides excellent printability, rapid curing, and moist heat resistance, preventing adhesive bleeding and contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional adhesives are used for bonding fuel cell separators, then bonding can be achieved, but the adhesive lacks high-temperature durability and resistance to moist heat
Solution Approach 1:
The patent changes the chemical parameters of the adhesive system by incorporating specific epoxy resins with appropriate molecular weights, amine-type curing agents, and capsule-type curing accelerators in optimized ratios. This chemical parameter optimization enables the adhesive to achieve both high-temperature durability and rapid curability, resolving the contradiction between reliability and productivity
Solution Approach 2:
The patent creates a composite adhesive system combining epoxy resin, amine-type curing agent, capsule-type curing accelerator, and flaky inorganic filler. This composite formulation synergistically provides high-temperature durability, moist heat resistance, and rapid curability, simultaneously improving reliability and productivity
2Productivity
If the adhesive cures rapidly, then productivity increases, but adhesive ingredients may bleed out and contaminate areas during lamination
Solution Approach 1:
The patent optimizes the molecular weight and chemical structure parameters of the epoxy resin and curing agent system to achieve rapid curing without excessive reactivity that would cause bleeding. The capsule-type curing accelerator is designed to release at controlled rates, enabling fast curing while preventing ingredient migration and contamination during lamination
Solution Approach 2:
The flaky inorganic filler acts as an intermediary component that reinforces the adhesive matrix, preventing ingredient bleeding and contamination during the lamination process. The filler particles create a physical barrier that maintains adhesive integrity while allowing rapid curing to proceed
3Productivity
If screen printing is used to apply adhesive, then productivity increases, but residual adhesive may remain in mesh openings of the screen printing plate
Solution Approach 1:
The patent adjusts the viscosity and surface tension parameters of the adhesive formulation to optimize screen printing performance. The modified adhesive flows easily through the screen mesh during printing but maintains its shape after deposition, preventing residual adhesive from remaining in mesh openings and ensuring clean transfer to the separator surface
Solution Approach 2:
The patent utilizes capillary action and surface tension effects (hydraulic principles) in the adhesive formulation to enable complete evacuation of adhesive from screen mesh openings during the printing process. The adhesive's rheological properties are designed to allow air or inert gas to push the adhesive through the mesh efficiently, leaving no residue that would contaminate the printed pattern
4Reliability
If O-rings or rubber seals are used to prevent gas leakage, then sealing can be achieved, but they are insufficient for preventing gases from leaking out
Solution Approach 1:
The patent merges the separator and MEA into an integral bonded structure using the epoxy-based adhesive, eliminating the need for separate O-rings or rubber seals. This merging of components achieves superior gas leakage prevention while simplifying the overall sealing structure, directly resolving the contradiction between reliability and device complexity
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 adhesive ensures reliable bonding of fuel cell separators with high productivity, maintaining integrity under moist heat conditions and preventing gas leaks, thus enhancing fuel cell performance and longevity.
Implementation Method 1
a curing accelerator which includes a capsule-type curing accelerator
Implementation Method 2
a curing agent which includes an amine-type curing agent
Data Source
AI summary
Provided is a one-pack type adhesive which contains (A) an epoxy resin, (B) a curing agent, (C) a curing accelerator, (D) an inorganic filler and (E) a polycarbodiimide compound, and wherein: the curing agent (B) contains at least one amine-based curing agent; the curing accelerator (C) contains at least one capsule type curing accelerator; the inorganic filler (D) contains at least one flake-like inorganic filler; and the content of the inorganic filler (D) is 10-200 parts by mass relative to 100 parts by mass of the epoxy resin (A).