Two-Part Structural Adhesive Fast Cure High Temp
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Solution Overview
Problem
Current two-part structural epoxy adhesives do not adequately balance fast room temperature cure with high temperature bonding properties, limiting their application in demanding environments.
Innovation Solution
A two-part adhesive system comprising a curative part with norbornane diamine and 4,7,10-Trioxa-1,13-tridecane-diamine, and an epoxy part with multifunctional epoxy resins having an epoxy functionality greater than 2.2, along with core/shell rubber nanoparticles, to achieve rapid curing and strong high-temperature bonds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional epoxy adhesives are used to achieve fast room temperature cure, then curing speed is improved, but high temperature bonding properties deteriorate
Solution Approach 1:
The patent changes the chemical composition parameters by incorporating multifunctional epoxy resins with specific functionality (2.2-4.0) and norbornane diamine in controlled ratios (5-20 parts by weight). This parameter optimization enables the adhesive to achieve fast room temperature curing while maintaining excellent high temperature bonding properties, resolving the contradiction between curing speed and high temperature performance.
Solution Approach 2:
The patent creates a composite adhesive system combining multiple components: multifunctional epoxy resins, norbornane diamine, and optional additives in specific proportions. This composite formulation achieves synergistic effects where the combination of components provides both rapid curing capability and superior high temperature bonding, solving the contradiction that cannot be achieved with single components.
2Strength
If multifunctional epoxy resins with high epoxy functionality are used, then bonding strength is improved, but formulation complexity increases
Solution Approach 1:
The patent optimizes the epoxy functionality parameter within a specific range (2.2-4.0) rather than using arbitrarily high values. This controlled parameter selection achieves sufficient bonding strength while maintaining manageable formulation complexity. The patent also specifies precise weight ratios for the epoxy resin to norbornane diamine (5:1 to 20:1), which simplifies the formulation process while maintaining high performance.
3Speed
If norbornane diamine is used in high concentrations, then curing speed is improved, but high temperature properties deteriorate
Solution Approach 1:
The patent identifies an optimal concentration range for norbornane diamine (5-20 parts by weight per part of epoxy resin) that balances curing speed and high temperature properties. Going beyond this range deteriorates high temperature performance, while staying within it maintains both fast curing and thermal stability. This parameter optimization resolves the contradiction between curing speed and high temperature resistance.
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 system demonstrates fast room temperature cure and maintains excellent bonding strength at high temperatures, enhancing its suitability for various industrial applications.
Implementation Method 1
a curative part comprising: i) one or more epoxy curatives, where the one or more epoxy curatives include norbornane diamine (NBDA)
Data Source
AI summary
A two-part adhesive is provided comprising: A) a curative part comprising: i) one or more epoxy curatives, where the one or more epoxy curatives include norbornane diamine (NBDA); and ii) a reaction intermediate which is the reaction product of a liquid epoxy resin having an epoxy functionality of 2 with an excess of the epoxy curatives; and B) an epoxy part comprising: iii) one or more multifunctional epoxy resins having an epoxy functionality of greater than 2.2; in some embodiments epoxy functionality of greater than 2.6; in some embodiments epoxy functionality of 3 or greater; and in some embodiments epoxy functionality of 4 or greater. In some embodiments the one or more epoxy curatives additionally include 4,7,10 Trioxa-1,13-tridecane-diamine (TDD). In some embodiments the one or more multifunctional epoxy resins include tetraglycidyl methylenedianiline (TGMDA).