Sulfide-Extended Epoxy Resin Oxygen Barrier Coatings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current oxygen barrier coatings, particularly those based on chlorinated polymers and poly(vinyl alcohol) or ethylene/vinyl alcohol copolymers, fail to provide effective oxygen barrier properties at relative humidity levels above 75%, limiting their use in humid climates, and there is a need for non-chlorinated, high-speed, in-line printable oxygen barrier coatings.
Innovation Solution
A gas barrier coating composition incorporating a resin with β-hydroxysulfide moieties formed by reacting multifunctional glycidyl ethers with mercapto compounds, which reduces oxygen transmission rates without using bound chlorine, and can be applied as a single layer on packaging materials, eliminating the need for additional adhesives and reducing processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chlorinated polymers or PVA/EVOH are used for oxygen barrier coatings, then good oxygen barrier properties are achieved at low relative humidity, but oxygen transmission rate increases significantly at relative humidity higher than 75%
Solution Approach 1:
The patent changes the chemical composition parameters of the resin by incorporating sulfide groups (β-hydroxysulfide moieties) into the polymer structure. This chemical modification alters the resin's interaction with water molecules, preventing the barrier property degradation that occurs in conventional polymers at high humidity. The sulfide groups create a more stable barrier mechanism that is not compromised by moisture absorption.
Solution Approach 2:
The invention creates a composite resin system by combining epoxy resins with sulfide-containing compounds (such as mercapto compounds or thiadiazole derivatives). This composite approach integrates the beneficial properties of both components: the epoxy resin provides structural integrity and adhesion, while the sulfide groups provide moisture-resistant oxygen barrier properties, achieving both low OTR and high humidity adaptability.
2Object-affected harmful factors
If non-chlorinated polymers are used to replace chlorinated polymers, then environmental and regulatory compliance is improved, but oxygen barrier properties at high relative humidity remain insufficient
Solution Approach 1:
The patent modifies the chemical structure of non-chlorinated polymers by incorporating sulfide groups into the resin matrix. This parameter change in molecular structure fundamentally alters the barrier mechanism, creating a moisture-resistant oxygen barrier that maintains effectiveness at high relative humidity while containing no bound chloride, thus satisfying both environmental compliance and performance requirements.
Solution Approach 2:
The invention converts the typical weakness of non-chlorinated polymers (susceptibility to humidity-induced barrier degradation) into a benefit by introducing sulfide groups that specifically resist moisture absorption. The sulfide groups create hydrophobic interactions that prevent water from disrupting the oxygen barrier pathway, turning the potential harm of humidity into an opportunity for enhanced performance.
3Reliability
If conventional barrier coatings are applied, then oxygen barrier properties are achieved, but additional adhesives and multiple layers are required, increasing device complexity and processing time
Solution Approach 1:
The patent merges the functions of the barrier coating and adhesive into a single integrated resin system. The epoxy-based resin with sulfide groups provides both excellent oxygen barrier properties and strong adhesion to substrates like PET and nylon. This consolidation eliminates the need for separate adhesive layers, reducing the total number of coating layers from two or more to just one, thereby simplifying the overall coating structure.
Solution Approach 2:
The invention creates a universal coating resin that performs multiple functions simultaneously: it provides oxygen barrier protection, ensures strong substrate adhesion, and maintains flexibility for high-speed printing applications. This multi-functional resin replaces the need for specialized separate coatings for each function, reducing complexity while maintaining or enhancing overall performance.
4Reliability
If conventional barrier coatings are used, then oxygen barrier properties are achieved, but processing time and production speed are reduced due to multiple coating steps
Solution Approach 1:
The patent combines multiple coating functions into a single resin formulation that can be applied in one coating pass. This single-layer system eliminates the need for sequential application of barrier and adhesive layers, reducing the number of drying and curing cycles. The result is a streamlined process that maintains excellent oxygen barrier properties while enabling high-speed printing operations without compromising barrier performance.
Solution Approach 2:
The invention allows the coating process to skip intermediate steps by using a resin that inherently provides both barrier and adhesion properties. Instead of applying a barrier layer, drying it, then applying an adhesive layer and drying again, the single-functional resin enables the process to rush through directly to one application and one cure cycle, significantly reducing total processing time and increasing productivity.
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 coating achieves oxygen transmission rates of less than 50 cc/m²-day at 50% relative humidity and less than 35 cc/m²-day at 75% relative humidity, with a coating weight of less than 2 grams per square meter, providing excellent oxygen barrier properties across varying humidity levels.
Implementation Method 1
The coating achieves oxygen transmission rates of less than 50 cc/m²-day at 50% relative humidity and less than 35 cc/m²-day at 75% relative humidity
Data Source
AI summary
Provided is an oxygen barrier coating composition includes a resin including a compound of the following formula: where R1 is an alkyl, cycloalkyl, aryl, alkyl aryl, glycol or polyol group, where the alkyl, cycloalkyl, aryl, alkyl aryl, glycol or polyol group is substituted with one or more glycidyl groups, the alkyl group of R1 is further substituted with one or more OH, cycloalkyl, aryl, heteroaryl or glycidyl ethers or combinations thereof, and the cycloalkyl, aryl, alkyl aryl, glycol or polyol group of R1 optionally is substituted with one or more alkyl, OH, cycloalkyl, aryl, heteroaryl or glycidyl ethers or combinations thereof, and R2 is an alkyl, cycloalkyl, aryl or heteroaryl group, where the alkyl, cycloalkyl, aryl or heteroaryl group is substituted with one or more mercapto groups, and the aryl, alkyl aryl, alkyl, cycloalkyl or heteroaryl group optionally is substituted with one or more alkyl, OH, cycloalkyl, aryl, heteroaryl or glycidyl ethers or combinations thereof. Also provided are methods of reducing the transmission rate of a gas through a substrate, the method including applying the gas barrier coating composition provided herein on the substrate and drying the gas barrier coating composition.