Rare-Earth Ink Composition for High-Intensity Light Resistance
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Solution Overview
Problem
Conventional fluorescent inks used for security marking in printed products face challenges in maintaining high light emission intensity and resisting color changes when exposed to natural light, making them ineffective in preventing counterfeiting.
Innovation Solution
An ink composition comprising a rare-earth complex with trivalent rare-earth ions and a phosphine oxide ligand, combined with a light-emitting material, is developed to achieve a desired emitted light color with high intensity and excellent light resistance, using a structure that prevents vibrational deactivation and increases light emission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional fluorescent inks are used to achieve high light emission intensity, then the light emission intensity is improved, but the light resistance deteriorates causing color changes over time
Solution Approach 1:
The patent changes the chemical composition parameters of the fluorescent ink by incorporating specific rare-earth complexes (Eu³⁺, Tb³⁺, Dy³⁺, Er³⁺, Tm³⁺, Ho³⁺, Nd³⁺, Pr³⁺) with defined coordination structures. This parameter change enables the ink to achieve both high light emission intensity and excellent light resistance, resolving the contradiction between brightness and stability under light exposure.
Solution Approach 2:
The patent uses composite rare-earth complex structures combining multiple ligands (phosphine oxide, carboxylic acid, β-diketone, aromatic hydrocarbon) with rare-earth ions. This composite material approach creates a stable coordination structure that maintains high light emission intensity while providing excellent light resistance, preventing the color changes that occur with conventional fluorescent inks.
2Reliability
If conventional fluorescent inks are used for security marking, then the anti-counterfeiting feature is provided, but the emitted light color control capability deteriorates
Solution Approach 1:
The patent utilizes the inherent emission characteristics of different rare-earth ions (Eu³⁺ for red, Tb³⁺ for green, Dy³⁺ for yellow, Er³⁺ for red, Tm³⁺ for blue, Ho³⁺ for yellow, Nd³⁺ for red, Pr³⁺ for red) to precisely control the emitted light color. This parameter-based approach enables accurate color control for design purposes while maintaining high anti-counterfeiting effectiveness.
Solution Approach 2:
The patent deliberately selects and combines different rare-earth ions to achieve specific emitted light colors (red, green, yellow, blue) for security marking applications. This color control capability allows for customized design features while ensuring the marked products have enhanced anti-counterfeiting properties through controlled fluorescence characteristics.
3Illumination intensity
If organic light-emitting materials are used to achieve high light emission intensity, then the light emission intensity is improved, but the light resistance deteriorates
Solution Approach 1:
The patent employs composite rare-earth complex structures with stable coordination spheres formed by phosphine oxide, carboxylic acid, and β-diketone ligands. This composite structure provides both high light emission intensity and excellent color stability, overcoming the limitation of organic light-emitting materials that degrade and change color under prolonged light exposure.
Solution Approach 2:
The rare-earth complex structure creates a chemically inert coordination environment that protects the light-emitting center from degradation by oxygen and moisture. This inert coordination sphere maintains the stability of the emitted light color over time while preserving high light emission intensity, solving the degradation problem of organic materials.
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 ink composition achieves a desired emitted light color with high light emission intensity and excellent light resistance, effectively enhancing anti-counterfeiting properties and design features in printed products.
Implementation Method 1
a rare-earth complex containing one kind of trivalent rare-earth ion selected from the group consisting of Eu 3+ in the general formula (1)... wherein an emitted light color is white
Implementation Method 2
a rare-earth complex containing one kind of trivalent rare-earth ion selected from the group consisting of Eu 3+ in the general formula (1), Ar 1 and Ar 2 are each independently an aromatic group optionally containing a substituent group
Data Source
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AI summary
An ink composition comprising: a rare-earth complex containing one kind of trivalent rare-earth ion selected from the group consisting of Eu3+, Tb3+, Sm3+, Er3+, Pr3+, Ho3+, Tm3+ and Dy3+, and a specific phosphine oxide ligand coordinated to the rare-earth ion, and a light-emitting material different from the rare-earth complex, wherein an absolute value of a difference between a wavelength (λ1) at which a light emission intensity of the rare-earth complex is maximum and a wavelength (λ2) at which a light emission intensity of the light-emitting material is maximum, is 50 nm or more.