Antimicrobial Coating for Security Paper Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current security papers for valuable documents, such as banknotes, are prone to premature contamination and microbial growth due to their porous nature, leading to reduced circulation time and potential health risks, while existing antimicrobial coatings often compromise the document's properties or lead to environmental hazards.
Innovation Solution
A security paper with a flat substrate coated with a dirt-repellent, antimicrobial layer containing a combination of 1,2-benzisothiazol-3(2H)-one (BIT) and silver-based antimicrobial agents, applied in multiple layers to enhance durability and maintain the document's tactile properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a porous paper substrate is used for banknotes, then the paper provides good grip and flexibility, but the high surface roughness promotes dirt deposits and microbial growth
Solution Approach 1:
A thin film coating is applied to the porous paper substrate to create a protective barrier. The coating fills the pores and smooths the surface, preventing dirt and microorganisms from penetrating and adhering to the paper, while maintaining the underlying flexibility and grip characteristics of the porous structure.
Solution Approach 2:
The invention combines the porous paper substrate with a protective coating layer to create a composite material structure. The porous paper provides mechanical properties (flexibility, grip), while the coating layer provides protection against contamination and microbial growth, achieving both requirements simultaneously.
2Object-affected harmful factors
If existing antimicrobial coatings are applied to security papers, then microbial growth is reduced, but the document's tactile properties and environmental safety are compromised
Solution Approach 1:
The coating is designed to provide antimicrobial protection specifically where needed on the surface, while maintaining the natural tactile properties of the paper in areas where contact is expected. The coating composition and application method are optimized to preserve the document's characteristic feel and sound.
Solution Approach 2:
The invention uses specific chemical parameters in the coating formulation, including controlled amounts of antimicrobial agents combined with surface-modifying compounds that alter surface energy and roughness parameters. This creates a coating that is effective against microorganisms but maintains appropriate tactile properties for handling.
3Duration of action of stationary object
If the circulation time of banknotes is extended through protective measures, then fewer documents need to be produced, but the protective equipment may impair security features or harm the environment
Solution Approach 1:
The invention extracts and applies only the necessary protective functions to the banknote surface through a thin coating, rather than using bulk protective materials. This minimal intervention approach extends circulation life without adding significant mass or interfering with security features embedded in the paper structure.
Solution Approach 2:
The coating is designed as a thin, lightweight layer that provides protection throughout the extended circulation period. The coating materials are selected to be environmentally degradable after their service life, combining long-term protection with eventual environmental safety.
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 effectively extends the lifespan of valuable documents by preventing microbial growth and contamination, maintaining the typical feel and sound of banknotes, while ensuring environmental safety and compatibility with security features.
Implementation Method 1
a dirt-repellent, antimicrobial coating in order to extend the service life and fitness for circulation and to avoid endangering users from pathogenic microorganisms
Implementation Method 2
a dirt-repellent, antimicrobial coating in order to extend the service life and fitness for circulation
Data Source
Figure 1~2
Figure 3~4
AI summary
Security paper (1) comprises a flat substrate (2) at least partially provided with a stain-resistant and antimicrobial coating (3, 4). The coating comprises 1,2-benzisothiazol-3-(2H)-one as at least one first anti-microbial agent (10) and silver as a second antimicrobial agent (11). Independent claims are also included for: (1) the valuable document e.g. bank note, identity document or certificate, comprising the above mentioned security paper; (2) producing the above mentioned security paper, comprising providing the flat substrate with a first substrate surface and a second substrate surface, applying the above mentioned coating on the first substrate surface and/or on the second substrate surface by optionally applying a coating composition for forming a lower layer on the substrate, where the coating includes an upper layer or the upper layer and a lower layer that is present between the substrate and the upper layer, and applying the coating composition for forming the upper layer on the substrate or the lower layer; and (3) producing the valuable document e.g. banknote, identity document or certificate, comprising providing the above mentioned security paper with at least one security element.