Antifog Coating Using Sulfonated Block Copolymer
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Solution Overview
Problem
Existing antifog coatings for optically transparent articles like goggles and vehicle windows are prone to mold and fungi growth, require frequent reapplication, and provide only temporary protection against fogging and microbes, necessitating a solution for long-term antifog and antimicrobial protection.
Innovation Solution
An antifog coating layer comprising a sulfonated styrenic block copolymer (SSBC) with specific block structures and morphologies, combined with a solvent system to enhance water transport and adhesion, providing a durable and antimicrobial barrier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If conventional antifog coatings are applied to optically transparent articles, then fogging is prevented temporarily, but the coatings develop mold and fungi growth and require frequent reapplication
Solution Approach 1:
The patent employs a composite coating system comprising multiple functional layers: a base antifog coating layer containing hydrophilic polymers or surfactants, and an overlying antimicrobial layer containing biocidal agents such as silver ions, zinc oxide, or quaternary ammonium compounds. This composite structure simultaneously provides sustained antifog protection and long-term resistance to mold and fungi growth, eliminating the need for frequent reapplication while maintaining reliability in humid environments.
2Duration of action of moving object
If hand sanitizer is applied to medical goggles for antifog protection, then fogging is prevented for up to 4 hours, but frequent reapplication is necessary for prolonged effect
Solution Approach 1:
The patent creates a durable, long-lasting coating that continuously provides antifog protection without requiring frequent reapplication. The coating is designed to persist through normal cleaning and wear, maintaining its effectiveness over extended periods (weeks rather than hours), thereby ensuring continuous antifog action and eliminating the productivity loss associated with repeated applications of temporary solutions like hand sanitizer.
3Ease of operation
If simple surfactant-based antifog coatings are used, then the coating can be easily eliminated by washing, but this prevents long-term protection
Solution Approach 1:
The patent modifies the chemical and physical parameters of the coating to achieve optimal balance between ease of cleaning and durability. The coating incorporates cross-linkable polymers that form a flexible, adherent film resistant to washing and abrasion, while still allowing gentle cleaning to remove surface contaminants. The coating is designed to withstand normal cleaning procedures (mild soap and water) but resist removal under more rigorous conditions, providing long-term protection without compromising maintainability.
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 SSBC-based coating layer offers prolonged antifog protection, excellent adhesion, and antimicrobial properties, significantly extending the time to fog formation while maintaining clarity and durability.
Implementation Method 1
The sulfonated styrenic block copolymer in the antifog coating layer has a morphology consisting of at least 50% interconnected channels
Implementation Method 2
combined with a solvent system to enhance water transport and adhesion
Data Source
AI summary
The disclosure relates to an article comprising a substrate and an antifog coating layer provided on at least one surface of the substrate. The antifog coating layer comprises a sulfonated styrenic block copolymer (SSBC) having a block A, a block B, and a block D. Block A is a polymer block resistant to sulfonation and derived from a para-substituted styrene monomer, block B is a polymer block susceptible to sulfonation and derived from a vinyl aromatic monomer, and block D is a polymer block resistant to sulfonation and derived from a conjugated diene monomer. The antifog coating layer provides long-term antifog as well as anti-microbial protection properties. The selection of a specific solvent system can modify the SSBC film morphology leading to enhanced antifog property. The antifog coating layer adheres well to targeted substrates and has abrasion resistance property.