Room-Temperature Epoxy Structural Adhesive for Rapid High-Strength Bonding
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Solution Overview
Problem
Existing structural adhesives face challenges in achieving rapid bonding at room temperature without heat, while maintaining high bonding strength, and often involve harmful components or lengthy curing processes.
Innovation Solution
A composition comprising an epoxy resin, macromolecular polyol, isocyanate, glycerol carbonate, polyamine curing agent, and catalyst, which forms a toughened molecular network through branched polyurethane structures, enabling rapid curing and high bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If epoxy adhesives are used to achieve high bonding strength, then bonding strength is improved, but curing requires high temperature
Solution Approach 1:
The patent changes the chemical parameters of the curing system by using polyamine curing agents with specific functional groups (amino groups) that enable low-temperature curing. The epoxy adhesive composition is modified to include curing agents with multiple amino groups per molecule, which fundamentally alters the curing temperature parameter from high temperature to room temperature or low temperature ranges while preserving high bonding strength through effective crosslinking reactions.
2Temperature
If room temperature curing is implemented, then temperature requirement is reduced, but curing time increases to 7 days
Solution Approach 1:
The patent incorporates preliminary action by adding catalysts to the epoxy adhesive composition before application. These catalysts are pre-selected and pre-dosed to accelerate the curing reaction from the moment mixing occurs. The catalysts work immediately upon contact with moisture or through their inherent catalytic activity, initiating rapid crosslinking without requiring extended waiting periods, thus reducing curing time from 7 days to significantly shorter durations while maintaining room temperature curing.
Solution Approach 2:
The patent changes the kinetic parameters of the curing reaction by introducing catalysts that lower the activation energy barrier. This parameter change enables the curing reaction to proceed at practical speeds at room temperature, transforming an otherwise extremely slow room-temperature curing process into a rapid one that achieves full strength in hours rather than days.
3Productivity
If rapid bonding is achieved, then productivity is improved, but bonding strength may be compromised
Solution Approach 1:
The patent creates a composite curing system that combines multiple curing agents with different reaction characteristics. The polyamine curing agents provide rapid initial crosslinking for quick strength development, while the epoxy resin matrix ensures ultimate high bonding strength. This composite approach allows the adhesive to achieve both rapid bonding (high productivity) and high bonding strength by leveraging the complementary properties of different chemical components working together in the same system.
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 achieves rapid bonding strength increase to 16.0 MPa within 4 hours, stabilizing at 21 MPa after 7 hours, with improved toughness and resistance to solvents and environmental conditions, maintaining strength comparable to traditional heat-cured adhesives.
Implementation Method 1
a polyamine curing agent... enabling rapid curing and high bonding strength
Implementation Method 2
forms a toughened molecular network through branched polyurethane structures
Implementation Method 3
a catalyst... achieving rapid bonding strength increase
Data Source
AI summary
The present disclosure relates to the technical field of epoxy-based structural adhesives, in particular to the field of IPC C09J163, and more specifically relates to an epoxy-based structural adhesive capable of curing at room temperature and rapid bonding and a preparation method therefor. The adhesive includes: an epoxy resin, a macromolecular polyol, an isocyanate, a glycerol carbonate, a polyamine curing agent, and a catalyst. In the present application, by using glycerol carbonate terminated polyurethane to achieve a toughening effect and using a polyamine as the rapid curing agent, an epoxy-based structural adhesive capable of curing at room temperature and rapid bonding is obtained. Not only is the problem of a low curing speed solved, but also high bonding strength after curing is ensured.