Dichroic Security Features Using UV-Cured Silver Nanoplatelet Inks
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Solution Overview
Problem
Existing methods for producing overt security features using silver nanoplatelets lack reliability, ease of implementation, and speed, particularly in high-demand applications requiring high counterfeiting resilience and excellent optical properties, and do not allow for easy, direct authentication by humans without external devices.
Innovation Solution
A method involving the application of a UV-Vis radiation curable ink containing silver nanoplatelets and specific additives, followed by a top coating composition, cured within 5 seconds using contactless fluid microdispensing, to create security features with distinct optical characteristics visible in transmitted and incident light.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods for producing overt security features using silver nanoplatelets are used, then the security features can be produced, but the methods lack reliability, ease of implementation, and production speed
Solution Approach 1:
The patent applies parameter changes by optimizing the UV-Vis radiation curable ink composition with specific weight percentages of silver nanoplatelets (7.5-20 wt%), cycloaliphatic epoxide (45-80 wt%), and other components. It also specifies precise curing conditions (UV-Vis radiation, 5 seconds) and processing parameters (contactless fluid microdispensing) to ensure reliable and easy production of security features with consistent optical properties
Solution Approach 2:
The patent replaces conventional mechanical application methods with UV-Vis radiation curing technology. The curable ink is applied in a liquid state and then cured through UV-Vis radiation exposure, eliminating the need for complex thermal or mechanical curing processes. This substitution improves both reliability and ease of manufacture while enabling industrial-scale production
2Productivity
If conventional security feature production methods are used, then production can occur, but the production speed is insufficient for high-demand applications
Solution Approach 1:
The patent implements continuous production through a streamlined process where the UV-Vis radiation curable ink is applied and cured in a continuous manner. The contactless fluid microdispensing system enables continuous application of the ink followed by immediate UV-Vis curing, eliminating interruptions and maximizing production speed while maintaining consistent security feature quality and counterfeiting resilience
Solution Approach 2:
The replacement of thermal or mechanical curing with UV-Vis radiation curing enables faster production cycles. The UV-Vis curing process occurs instantly upon exposure, eliminating the need for prolonged heating or complex mechanical curing mechanisms, thereby significantly increasing production speed without compromising the optical properties or counterfeiting resistance
3Ease of operation
If security features are produced without distinct optical characteristics, then production is simpler, but human authentication becomes difficult
Solution Approach 1:
The patent utilizes color changes by formulating the UV-Vis radiation curable ink with silver nanoplatelets that provide distinct optical characteristics. The cured security features exhibit specific color properties that are easily distinguishable to the human eye, enabling simple authentication. The ink composition and curing process are optimized to produce consistent, visually distinct features without requiring complex production equipment or multi-step processes
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 production of eye-catching, easily recognizable security features with high contrast and optical properties, suitable for industrial-scale production, allowing unambiguous authentication by humans.
Implementation Method 1
UV-Vis radiation curable ink... UV-Vis curing the ink layer obtained at step b) to form the security feature
Implementation Method 2
Dichroic security features exhibiting a first color upon viewing in transmitted light and a second color different from the first color upon viewing in incident light
Data Source
Figure 1A~2
Figure 3A~3B
AI summary
The present invention relates to the field of methods for producing eye-catching overt security features exhibiting one or more indicia as anti-counterfeit means on value documents or articles as well as decorative purposes. In particular, the present invention provides methods for producing security features that can be easily, directly and unambiguously authenticated by the human without any external device or tool, wherein said security features comprised a cured ink and one or more cured indicia, said ink comprising cured cationically curable compounds or cured hybrid curable compounds and silver nanoplatelets.