Thermally Triggered Silyl Hydride Epoxide Curing via Amine Blocking
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Solution Overview
Problem
Existing Lewis acid catalyzed reactions, such as those between silyl hydrides and epoxides, are highly reactive and difficult to control, making it challenging to create shelf-stable one-part systems that can be triggered to react on demand, especially when exposed to UV light or at elevated temperatures.
Innovation Solution
A composition comprising a silyl hydride, epoxide, and a thermally triggered amine blocking agent that complexes with the Lewis acid catalyst at room temperature, preventing reaction, but releases the catalyst at elevated temperatures to initiate the reaction, allowing for a shelf-stable one-part system that can be triggered to react quickly upon heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If UV light sensitive blocking agents are used to block Lewis acid catalysts, then the system can be stored stably in the dark, but the system requires UV light exposure to initiate reaction and needs to be kept in the dark during storage
Solution Approach 1:
The patent changes the triggering parameter from UV light exposure to thermal energy. The amine blocking agent is selected to release the Lewis acid catalyst at elevated temperatures (e.g., above 50°C) while maintaining stable complexation at room temperature, enabling simple thermal initiation without UV light equipment and eliminating the need for dark storage.
2Productivity
If the reaction system is made highly reactive to achieve fast curing, then the cure speed improves, but the system becomes difficult to control and reacts too quickly once components are combined
Solution Approach 1:
The patent applies preliminary action by pre-complexing the Lewis acid catalyst with the amine blocking agent in a stable complex that can be stored indefinitely at room temperature. The actual catalytic activity is postponed until thermal energy triggers the release of the catalyst from the complex, providing precise control over when the fast reaction occurs.
3Ease of operation
If a one-part system is created to simplify application, then the ease of operation improves, but the system loses shelf stability because reactants and catalyst would react immediately upon mixing
Solution Approach 1:
The patent introduces an intermediary substance (the amine blocking agent) that temporarily deactivates the Lewis acid catalyst by forming a stable complex. This intermediary allows all reaction components to coexist in a single part without immediate reaction, and can be removed by applying thermal energy during use, enabling both one-part simplicity and shelf stability.
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 rapid curing at elevated temperatures (e.g., 95 °C) with a cure speed of 10 minutes or less, maintaining stability at room temperature and allowing for controlled reaction initiation, suitable for applications in coatings and adhesives.
Implementation Method 1
Heating the composition releases the Lewis acid catalyst from the amine blocking agent and allows it to catalyze a reaction between the silyl hydride and epoxide
Implementation Method 2
Strong Lewis acids are known catalysts for numerous reactions. For instance, the Piers-Rubinsztajn (PR) reaction between silyl hydride and silyl ether is a well-known reaction catalyzed by a strong Lewis acid, particularly tris(pentafluorophenyl) borane ('BCF')
Data Source
AI summary
A composition contains a mixture of silyl hydride, an epoxide, a Lewis acid catalyst and an amine having the following formula: R1 R2 R3 N; where the nitrogen (N) is not a member of a N=C-N linkage and wherein each of R1, R2, and R3 is independently selected from a group consisting of hydrogen, alkyl, substituted alkyl, and conjugated moieties; and wherein at least one of R1, R2, and R3 is a conjugated moiety connected to the nitrogen by a conjugated carbon if the epoxide is linear and wherein none of R1, R2, and R3 are connected to the amine nitrogen with a conjugated carbon if the epoxide is a cyclic epoxide.