Ethylene Copolymer Blend Interlayer for Safety Glazing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current safety laminates face challenges in achieving optimal adhesion to glass while maintaining water resistance and high impact resistance, particularly when exposed to water, due to limitations in interlayer materials used in laminates.
Innovation Solution
A safety laminate comprising an interlayer sheet made from a blend of ethylene copolymers with specific melt flow rates and compositions, including ethylene copolymer A and B, which are chemically distinct and contain units of esters or anhydrides of unsaturated acids and polar monomers, respectively, providing enhanced adhesion and water resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional interlayer materials (poly(vinyl butyral), poly(urethane), ethylene vinyl acetate copolymers, ionomeric ethylene carboxylic acid copolymers) are used, then the laminate achieves good adhesion to glass and toughness, but the laminate shows poor water resistance and bond integrity when exposed to water
Solution Approach 1:
The patent uses a composite material system consisting of ethylene copolymer A (with carboxylic acid groups) and ethylene copolymer B (with polar monomers) in a specific weight ratio range. This composite blend provides both water resistance and strong adhesion to glass, resolving the contradiction between water resistance and bond integrity that plagues traditional single-material interlayers.
Solution Approach 2:
The patent optimizes the composition parameters by controlling the weight ratio of copolymer A to copolymer B within specific ranges (e.g., 20:80 to 80:20), and by adjusting the comonomer content (3-20 wt% for copolymer A, 6-40 wt% for copolymer B). These parameter optimizations ensure the interlayer achieves both water resistance and strong glass adhesion simultaneously.
2Strength
If complex multicomponent compositions are used for interlayers, then the laminate achieves good adhesion and toughness, but the manufacturing process becomes more complex and costly
Solution Approach 1:
The patent creates a composite material system using two ethylene-based copolymers with different functional groups. This composite approach provides the adhesion performance of complex multicomponent systems while maintaining relative manufacturing simplicity, as both components are based on the same ethylene polymer platform.
Solution Approach 2:
The ethylene copolymer blend system serves multiple functions simultaneously: it provides adhesion to glass, water resistance, toughness, and processability. This multi-functionality reduces the need for additional additives or complex compositions, simplifying the overall material system while maintaining high performance.
3Strength
If thick polymer sheets are used for interlayers to ensure toughness, then the laminate achieves high impact resistance, but the adhesion to glass may be insufficient and water can penetrate more easily
Solution Approach 1:
The patent changes the chemical composition parameters of the interlayer material by incorporating ethylene copolymer A with carboxylic acid groups (3-20 wt% comonomer) and ethylene copolymer B with polar monomers (6-40 wt% comonomer). This compositional change enhances adhesion to glass, allowing thinner interlayer sheets to achieve both sufficient toughness and strong adhesion, thereby improving water resistance.
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 laminate exhibits strong adhesion to glass and water resistance, maintaining bond integrity before and after water exposure, and supports high impact resistance, addressing the limitations of existing interlayer materials.
Implementation Method 1
polymeric sheets made from such ethylene copolymer blends can also form superior adhesive bonds to glass, and that such adhesive bonds are water resistant
Data Source
AI summary
Disclosed laminates particularly useful as safety glazings comprising a polymeric interlayer sheet, wherein the polymeric interlayer sheet comprises a blend composition of an ethylene copolymer A and an ethylene copolymer B, which has a melt flow rate of less than 100 g/10 min, as determined in accordance with ASTM D1238 at 190 °C and 2.16 kg, and wherein the ethylene copolymer A comprises copolymerized units of ethylene and about 3 to about 20 wt% of an ester or anhydride of a C4-C8 unsaturated acid having two carboxylic acid groups and the ethylene copolymer B comprises copolymerized units of ethylene and about 6 to about 40 wt% of a polar monomer selected from the group consisting of vinyl acetate, alkyl (meth)acrylates, and mixtures thereof.