Water-Based Barrier Adhesive for Food Packaging
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Solution Overview
Problem
Existing barrier films and compositions for food packaging applications suffer from insufficient barrier performance, high oxygen and water vapor transmission rates, long-term adhesion strength, and recyclability issues.
Innovation Solution
A water-based barrier adhesive comprising polyurethane, a water-soluble polymer with hydroxyl groups, and water, optionally with additives, which forms a laminate film with improved barrier and adhesive properties, enhancing oxygen and water vapor transmission rates while promoting recyclability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional adhesive compositions are used to bond films, then the films can be laminated together, but the oxygen transmission rate remains too high for various applications
Solution Approach 1:
The patent applies composite materials by combining polyurethane resin with water-soluble polymers (such as polyvinyl alcohol, carboxymethyl cellulose, or starch derivatives) to create an adhesive composition that provides both bonding and barrier functions. This composite approach enables the adhesive layer itself to act as an oxygen barrier, eliminating the need for separate barrier layers and reducing overall structure complexity while improving oxygen transmission rate performance
Solution Approach 2:
The adhesive composition is designed to perform multiple functions simultaneously: it provides adhesion between film layers and acts as an oxygen barrier. The water-soluble polymer components contribute to both the adhesive properties and the barrier performance, allowing a single layer to fulfill both roles and thereby simplifying the overall laminate structure
2Strength
If aqueous coating agents with polyurethane resin and water-soluble polymer are used, then adhesion is improved, but the oxygen transmission rate remains too high
Solution Approach 1:
The patent optimizes the molecular weight, composition ratio, and chemical structure parameters of the water-soluble polymer to achieve both adhesion and barrier performance. By adjusting parameters such as the degree of hydrolysis of polyvinyl alcohol or the substitution degree of carboxymethyl cellulose, the adhesive maintains strong bonding while developing sufficient oxygen barrier properties to meet application requirements
3Reliability
If polyester-based polyurethane dispersion and polyvinyl alcohol resin are used in specific ratios, then oxygen gas barrier properties improve, but long term adhesion stability and recyclability are compromised
Solution Approach 1:
The patent applies local quality by selecting specific types of polyurethane resins (aliphatic or aromatic) and water-soluble polymers with particular molecular weights and chemical characteristics. This localized optimization of material properties within the adhesive composition enables simultaneous achievement of oxygen barrier performance and long-term adhesion stability, rather than relying on broad ratio ranges alone
4Reliability
If barrier films with improved oxygen transmission rate are developed, then barrier performance increases, but water vapor transmission rate and recyclability remain problematic
Solution Approach 1:
The patent promotes recyclability by using water-soluble polymers that can facilitate the separation and recovery of film materials. The homogeneous composition of natural or semi-synthetic water-soluble polymers (such as carboxymethyl cellulose or starch derivatives) allows for easier material recovery and recycling processes compared to complex synthetic polymer blends, enabling sustainable packaging solutions
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 water-based barrier adhesive significantly reduces oxygen and water vapor transmission rates, maintains good adhesion properties, and enables the production of recyclable laminated films with over 95% monomaterial content, suitable for flexible packaging.
Implementation Method 1
a water-based barrier adhesive comprising: a polyurethane; at least one water-soluble polymer, wherein the water-soluble polymer comprises at least one hydroxyl group
Data Source
AI summary
The invention relates to a water-based barrier adhesive comprising: a polyurethane; at least one water-soluble polymer, wherein the water-soluble polymer comprises at least one hydroxyl group; and water; a barrier film comprising the same; a method for preparing the same; and the use thereof in food packaging.