Transparent Luminescent Security Coating for UV Authentication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing luminescent pigments and coatings used in security features scatter light significantly, reducing the transparency and visibility of security documents, making them appear matte or opaque, which compromises counterfeit protection.
Innovation Solution
A security element with a lacquer layer containing luminescent pigments and a binder, designed to have a transmittance of at least 75% in the visible wavelength range, minimizing light scattering and maintaining transparency while becoming visible under UV light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If luminescent pigments or coatings are used to increase counterfeit protection, then security features become detectable under UV light, but light scattering increases causing the coating to appear matte or opaque
Solution Approach 1:
The patent changes the particle size parameter of the luminescent pigments to less than 10 micrometers (preferably less than 5 micrometers), which reduces light scattering while maintaining the luminescent effect. This parameter change allows the coating to remain transparent in the visible spectrum while still providing UV detectability for counterfeit protection.
Solution Approach 2:
The patent uses composite material formulation by combining luminescent pigments with a clear lacquer or varnish base. This composite approach allows the luminescent properties to be preserved while the transparent matrix minimizes light scattering, achieving both security functionality and visual transparency.
2Reliability
If luminescent pigments are used in paint layers, then counterfeit protection is enhanced, but the paint layer becomes opaque or cloudy when dry
Solution Approach 1:
The patent applies parameter changes by controlling the particle size of luminescent pigments to be less than 10 micrometers and optimizing the binder composition. This ensures that the dried coating maintains high transparency (at least 75% transmittance in visible light) while preserving the luminescent properties for counterfeit protection.
Solution Approach 2:
The patent applies local quality by ensuring that the luminescent effect is localized to UV stimulation while maintaining visible transparency. The coating has different optical properties for different wavelengths: transparent in visible light but luminescent under UV, achieving both requirements simultaneously in different spectral regions.
3Illumination intensity
If transparent window areas are provided in security documents, then visibility is improved, but counterfeit protection features cannot be applied without altering optical effects
Solution Approach 1:
The patent applies parameter changes by using ultra-fine luminescent pigments (particle size < 10 micrometers) in the transparent window areas. This allows the application of security features in previously unusable transparent regions without compromising either visibility or counterfeit protection, as the fine pigments do not scatter visible light significantly.
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 solution provides high transparency and effective counterfeit protection by ensuring the security feature is invisible in normal light and detectable under UV illumination, maintaining optical effects without altering their perceptibility.
Implementation Method 1
luminescent pigments or the luminescent paint are not visible in the visible wavelength range of light, or they can be stimulated to emit visible light when exposed to electromagnetic waves outside the visible spectrum (ultraviolet (UV) (λ < 780 nm) radiation)
Implementation Method 2
the layer in a dried state, in particular in the visible wavelength range of light, has a transmittance of at least 75%, preferably 80%, particularly preferably 85%
Data Source
Figure 1~3
Figure 4~7
AI summary
The invention relates to a security element (1) for securities, security papers, or security items (2), and to a security, security paper, or security item (2). The security element (1) has a first side (3) and a second side (4), as well as a carrier layer (5) and at least one layer (6) of a lacquer containing luminescent pigments and at least one binder. It is provided that the layer (6) of the lacquer containing luminescent pigments and at least one binder has a transmittance of at least 75%, preferably 80%, and particularly preferably 85% in a dried state, especially in the visible wavelength range.