Laser Imaging Coatings With NIR-Activated Diacetylene Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Diacetylenes used in image formation are highly reactive to background radiation, leading to unstable colorless coatings that require purification and rapid color change, limiting their application range due to poor stability and high reactivity.
Innovation Solution
Utilizing activatable diacetylene compounds that are initially unreactive but become reactive upon activation, such as through melting and re-solidification, in combination with a near-infrared (NIR) absorbing agent, allowing for controlled color change reactions only in areas exposed to NIR light, while remaining stable to background radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If diacetylenes are used for image formation, then color change capability is achieved, but stability to background radiation deteriorates
Solution Approach 1:
The diacetylene compound is pre-coated on the substrate in an unreactive state before actual use. This preliminary coating allows the material to be prepared and stored without undergoing polymerization, and then activated only when needed by exposure to activation light, thereby achieving both color change capability and stability during storage and handling.
Solution Approach 2:
The invention changes the reactivity parameter of the diacetylene compound by controlling its exposure to activation light. The compound transitions from an unreactive state (when coated and stored) to a reactive state (when exposed to activation light), enabling controlled color change while maintaining stability under normal conditions.
2Reliability
If diacetylenes are purified via re-crystallisation, then stability is improved, but time consumption and waste increase
Solution Approach 1:
The invention extracts the problematic reactivity from the diacetylene compound by separating the coating application step from the polymerization step. The compound is applied in its raw form without requiring purification, and the polymerization reaction is triggered only when needed by exposure to activation light, eliminating the need for time-consuming re-crystallization processes.
Solution Approach 2:
The diacetylene compound is pre-coated on the substrate without purification, and the actual color-forming polymerization reaction is performed as a preliminary action only when and where needed through localized exposure to activation light, avoiding unnecessary purification steps and reducing time consumption and waste.
3Adaptability or versatility
If diacetylenes are applied as coatings, then application range is expanded, but unwanted polymerization increases
Solution Approach 1:
The diacetylene compound is pre-coated on various substrates in an unreactive state, allowing broad application across different materials and uses. The coating can be applied to substrates that would otherwise be incompatible with reactive diacetylenes, expanding the application range while preventing unwanted polymerization during coating and storage.
Solution Approach 2:
The invention changes the reactivity parameter of the diacetylene compound through controlled exposure to activation light, allowing the same coating to remain stable during application and storage but become reactive only when needed for image formation, thereby expanding application range while minimizing unwanted polymerization.
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 method enables the creation of stable coatings that can form images with controlled color changes, specifically from colorless to blue, magenta, red, orange, yellow, and green, without unwanted reactions, expanding the range of applications by preventing color change in unexposed areas.
Implementation Method 1
the coating can be prepared by applying the 'activatable' diacetylene in combination with a near infrared (NIR) absorbing agent. A NIR light source, such as a NIR fibre laser, can then be used to heat the coating only in the areas where the image is required
Implementation Method 2
10,12-Pentacosadiynoic acid is well known in the art to be an example of such a diacetylene. This compound is initially colourless in its unreacted state, but on exposure to UV light undergoes a topochemical polymerization reaction to generate a blue coloured polydiacetylene
Implementation Method 3
A UV light source, such as a germicidal lamp, is then used to flood the coating with UV light. However, the diacetylene compound only undergoes a colour change reaction to create an image in the areas which were initially exposed to NIR light
Implementation Method 4
10,12-Pentacosadiynoic acid is well known in the art to be an example of such a diacetylene. This compound is initially colourless in its unreacted state, but on exposure to UV light undergoes a topochemical polymerization reaction to generate a blue coloured polydiacetylene, which can then be transformed into a red coloured form by thermal perturbations
Data Source
AI summary
A method of forming an image on a substrate, which comprises applying to the substrate an activatable colour forming compound wherein said activatable colour forming compound is initially unreactive but becomes reactive upon activation; activating said colour forming compound in the areas of the substrate where the image is to be formed, and, reacting the activated colour forming compound into its coloured form to produce an image. A substrate imaged using this method is also provided.