Polymerized Films with Line Texture for Forgeryproof Markings
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Solution Overview
Problem
Existing forgeryproof markers based on chiral nematic compounds are unsatisfactory in terms of optical properties and ease of detection, and there is a constant need for novel solutions to prevent counterfeiting of valuable articles.
Innovation Solution
A process involving the thermal treatment of polymeric films composed of achiral nematic polymerizable monomers, with or without chiral dopants, to create films with line or fingerprint textures, which are then used for producing substrates or pigments suitable for optical filters, decorative media, and forgeryproof markers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If chiral nematic compounds are used for forgeryproof markings, then optical properties are improved, but detection difficulty increases and ease of manufacture deteriorates
Solution Approach 1:
The patent employs liquid crystalline compounds that exhibit color changes and optical anisotropy under different lighting conditions. The markings display characteristic interference patterns and color shifts that are easily detectable with simple UV light sources, converting complex optical properties into simple visual detection cues.
Solution Approach 2:
The invention utilizes changes in optical parameters (birefringence, helical pitch) of liquid crystalline compounds in response to environmental stimuli such as temperature and light. These parameter changes produce visually detectable patterns that simplify detection while maintaining optical sophistication.
2Reliability
If complex forgeryproof markers are developed to prevent counterfeiting, then reliability is improved, but ease of manufacture deteriorates
Solution Approach 1:
The patent utilizes phase transitions of liquid crystalline compounds, particularly the formation of cholesteric phases with specific helical structures during controlled cooling or polymerization. This phase transition naturally creates the forgeryproof optical patterns without requiring complex manufacturing equipment or multiple processing steps.
Solution Approach 2:
The liquid crystalline compounds self-organize into characteristic helical structures and interference patterns when subjected to simple processing conditions. This self-organization property eliminates the need for complex patterning equipment, masks, or multi-step fabrication processes, allowing reliable forgeryproof markings to be produced through simple coating and controlled phase transition.
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 process results in polymerized films with unique optical properties, enhancing their suitability for optical filters and making forgeryproof markings easier to detect, while being easy to prepare and implement.
Implementation Method 1
liquid-crystalline mixtures comprising at least one curable liquid-crystalline component A which reflects in the UV and/or visible wavelength range
Implementation Method 2
at least one radiation-absorbing and optionally fluorescent conjugated polycyclic compound
Implementation Method 3
radiation-absorbing and optionally fluorescent conjugated polycyclic compound
Implementation Method 4
use of particular chiral-nematic polymerizable monomers for producing forgeryproof markings
Implementation Method 5
The chiral nematic phase has particular optical properties: high optical rotation and marked circular dichroism
Implementation Method 6
polymerizing, applying a further layer which comprises dyes or pigments which absorb or fluoresce in the IR or UV region
Implementation Method 7
The copying and forging or articles of value, such as banknotes, certificates, luxury and brand articles, causes enormous economic damage
Data Source
Figure 1
AI summary
The present invention relates to a process for producing polymerized films with line texture or fingerprint texture or for producing substrates coated with polymerized films with line texture or fingerprint texture, to polymerized films, obtainable by this process, with line texture or fingerprint texture or substrates coated with polymerized films with line texture or fingerprint texture, to pigments obtainable by comminuting such films, to the use of such films, substrates or pigments as or in optical filter(s), polarizers, decorative media, forgeryproof markers, reflective media or for focusing light (in solar cells), to the use of such films as an antibacterial coating, to a forgeryproof marker which comprises such a film, and to a process for detecting forgeryproof markings.