Fluorescent Ink with Rare Earth Complex for High Luminosity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current fluorescent inks used for security measures are low in luminosity and prone to light scattering, making them recognizable under visible light and compromising security levels.
Innovation Solution
Development of a fluorescent ink with a rare earth complex having an asymmetric ligand structure, which enhances luminosity and prevents crystallization in the binder, ensuring the ink is transparent under visible light and emits strong fluorescence under UV rays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional fluorescent inks are used, then the ink can be printed on substrates, but the luminosity is low and light scattering occurs making the image recognizable under visible light
Solution Approach 1:
The patent changes the chemical composition parameters of the fluorescent substance by introducing specific heterocyclic groups and adjusting the molecular structure. This transforms the fluorescent material's properties to achieve both high luminosity and reduced light scattering, resolving the contradiction between brightness and transparency under visible light.
Solution Approach 2:
The patent creates a composite fluorescent substance combining multiple heterocyclic structures (triazole, tetrazole, oxadiazole, thiadiazole groups) with aromatic hydrocarbon frameworks. This composite molecular structure achieves synergistic effects that simultaneously enhance luminosity and prevent crystallization-induced light scattering.
2Reliability
If fluorescent ink is used to create hidden marks, then security is enhanced, but the ink may crystallize in the binder causing light scattering and reducing security
Solution Approach 1:
The patent modifies the molecular parameters of the fluorescent substance by incorporating flexible heterocyclic chains and adjusting the aromatic core structure. These parameter changes reduce the tendency toward crystallization while maintaining fluorescent properties, ensuring the ink remains amorphous and transparent in the binder.
Solution Approach 2:
The patent designs a fluorescent substance with a molecular structure that prioritizes amorphous stability over long-term crystalline durability. The structure is optimized to remain in a stable amorphous state within the binder, preventing the harmful effects of crystallization that would compromise security.
3Illumination intensity
If europium complex with β-diketone ligand is used, then red fluorescence is emitted, but the luminosity is low
Solution Approach 1:
The patent replaces simple β-diketone ligands with composite heterocyclic ligand structures containing triazole, tetrazole, oxadiazole, or thiadiazole groups combined with aromatic hydrocarbons. These complex ligand structures enhance the europium complex's luminosity through improved electronic properties and energy transfer efficiency.
Solution Approach 2:
The patent changes the ligand's chemical parameters by introducing heterocyclic nitrogen or sulfur atoms that enhance the ligand's electron-donating ability. This parameter change improves the metal-ligand charge transfer efficiency, resulting in significantly enhanced luminosity of the europium complex.
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 new fluorescent ink is high in luminosity, transparent under visible light, and effectively enhances security by making forged images detectable only under UV irradiation, thereby improving the security level of printed materials.
Implementation Method 1
the fluorescent substance which is not visible under visible light but can be made visible under the irradiation of ultraviolet rays through the emission of fluorescent light in the visible region
Implementation Method 2
the fluorescent ink employing the rare earth metal complex is advantageous in that it is possible to suppress light scattering at an image portion formed of the fluorescent ink, thereby making it possible to overcome, to some extent, the problem that the presence of the fluorescent ink can be recognized as an image-printed article is observed under visible light
Data Source
AI summary
A fluorescent image-printed article including a substrate, and an image formed on the substrate, wherein the image is formed from a fluorescent ink containing a binder, and a fluorescent substance which is dispersed in the binder, is capable of emitting fluorescence when irradiated with ultraviolet rays, and is substantially transparent to visible light, the fluorescent substance being formed of a rare earth complex containing, as a ligand, a compound represented by the following formula (1):