Aromatic Phosphorus Clathrate Curatives for Latent Resin Cure
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Solution Overview
Problem
Existing curable resin systems face challenges in achieving latency of cure, rapid cure, and flame retardancy, with existing clathrates not effectively addressing these needs.
Innovation Solution
The use of aromatic phosphorous-containing amino or hydroxy groups as host compounds in clathrates, combined with specific guest compounds, to create a clathrate structure that provides latent curing effects, enhancing cure speed, glass transition temperature, and flame retardancy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional curatives are used directly in resin systems, then rapid curing can be achieved, but premature curing occurs during storage reducing stability
Solution Approach 1:
The curative molecule is nested within the clathrate structure formed by the host compound. The host compound creates a cage-like structure that encapsulates the curative, preventing it from reacting with the resin during storage. When heated to the desired cure temperature, the clathrate structure breaks down and releases the curative, enabling rapid curing. This nesting approach resolves the contradiction by physically isolating the curative during storage while enabling its function during curing.
Solution Approach 2:
The invention changes the physical state and reactivity parameters of the curative by incorporating it into a clathrate structure. At storage temperature, the curative is trapped in the clathrate lattice with restricted mobility and reactivity. Upon heating to the curing temperature, the clathrate structure decomposes, releasing the curative in its active form. This parameter change from trapped to released state resolves the contradiction between storage stability and cure speed.
2Stability of the object's composition
If latency of cure is provided using existing clathrates, then storage stability is improved, but cure speed at desired temperature is insufficient
Solution Approach 1:
The invention optimizes the host compound structure to achieve optimal thermal decomposition characteristics. By selecting specific host compounds with appropriate lattice energies and structural features, the curative is held stably during storage but released rapidly at the desired cure temperature. This parameter optimization resolves the contradiction by tuning the stability-reactivity balance through host compound selection.
Solution Approach 2:
The invention creates a composite system where the host compound and curative form a clathrate composite with specific properties. The host compound provides structural stability for storage, while the curative provides curing functionality. The composite clathrate structure enables both long-term stability and rapid cure by combining these two components in a controlled manner, resolving the contradiction between stability and cure speed.
3Reliability
If standard curatives are used, then curing function is provided, but flame retardancy is not achieved
Solution Approach 1:
The host compound is designed to serve multiple functions: (1) forming the clathrate structure to provide latency and storage stability, (2) acting as a flame retardant through its chemical composition (phosphorous, nitrogen, or sulfur containing groups), and (3) enabling rapid cure when the curative is released. This multi-functionality resolves the contradiction by integrating flame retardancy into the curative delivery system itself, eliminating the need for separate flame retardant additives.
Solution Approach 2:
The invention merges the curative delivery function with the flame retardancy function in a single integrated system. The host compound that encapsulates the curative also provides flame retardant properties through its chemical structure. When the clathrate decomposes, it releases the curative while the host compound residues contribute to flame retardancy. This merging resolves the contradiction by combining two previously separate functions into one 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 clathrate system offers improved control over cure conditions, allowing for long-term storage stability and rapid cure at desired temperatures, while imparting high glass transition temperature and enhanced fire resistance to resin systems.
Implementation Method 1
the molecules may be bound by one of the hydrogens on the nitrogen forming a hydrogen bond with the oxygen functionality
Implementation Method 2
two or more molecules are bound via their molecular interaction
Implementation Method 3
the host element of the clathrate prevents the curative from reacting with the resin until the bond(s) between the host and the guest compound is broken so releasing the guest curative
Data Source
Figure 1~2
AI summary
The host compound in a clathrate is an amino or hydroxyl containing aromatic phosphorous compound, clathrates containing a resin curative and their use in curable resin compositions to produce moulded articles particularly fibre reinforced articles.