Universal Thermoplastic Adhesive for Multilayer Films
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional triple bubble films face challenges in maintaining adhesive strength between various polymer layers, such as polyethylene and polyamide, or polyester and polypropylene, requiring multiple distinct tie layer formulations, which complicates the manufacturing process.
Innovation Solution
A thermoplastic adhesive composition comprising maleic anhydride-grafted ethylene-based polymer, ethylene/α-olefin/non-conjugated diene interpolymer with a molecular weight distribution ≥ 2.5, and very low density polyethylene, along with an ethylene alkyl (meth)acrylate copolymer, providing adhesion to both polar and non-polar substrates after biaxial orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If multiple distinct tie layer formulations are used to achieve adhesion to different polymer layers, then adhesion strength is improved, but device complexity and manufacturing complexity increase
Solution Approach 1:
The patent develops a universal tie layer formulation based on polyethylene polymers and copolymers that can adhere to multiple different polymer substrates (polyolefins, polyamides, polyesters, etc.) through a single composition. This multi-functional adhesive layer eliminates the need for multiple specialized tie layers, thereby reducing manufacturing complexity while maintaining adhesion strength across different layer combinations.
Solution Approach 2:
The patent optimizes specific parameters of the polyethylene-based adhesive composition, including molecular weight distribution (MWD ≥ 2.5), density ranges (0.910-0.940 g/cm³), and compositional ratios of polymers and copolymers. These parameter optimizations enable the single tie layer formulation to achieve universal adhesion performance across polar and non-polar substrates after biaxial orientation, resolving the contradiction between adhesion strength and manufacturing simplicity.
2Reliability
If multiple distinct tie layer formulations are used for different polymer combinations, then adhesion reliability is improved, but the number of components and formulation complexity increase
Solution Approach 1:
The patent creates a single universal tie layer formulation that reliably adheres to multiple polymer types (polyolefins, polyamides, polyesters, biopolymers) through its optimized polyethylene-based composition. This eliminates the need for multiple distinct formulations, reducing the quantity of different substances required while maintaining adhesion reliability across various polymer combinations in multilayer films.
Solution Approach 2:
The tie layer employs a composite material system comprising specific blends of polyethylene polymers and copolymers with controlled molecular weight distribution and density. This composite formulation integrates multiple functional components into a single material that provides reliable adhesion to diverse substrates, reducing the need for multiple separate formulations while ensuring consistent performance.
3Ease of manufacture
If conventional tie layer formulations are used, then manufacturing process is simpler, but adhesion strength after biaxial orientation deteriorates
Solution Approach 1:
The patent implements specific parameter changes in the tie layer formulation, including molecular weight distribution (MWD ≥ 2.5), density (0.910-0.940 g/cm³), and compositional ratios of polyethylene polymers and copolymers. These optimized parameters enable the adhesive layer to maintain strong adhesion to polar and non-polar substrates after biaxial orientation, improving strength while keeping the manufacturing process simple through a single universal formulation.
Data Source
Figure 1
Figure 2
AI summary
Embodiments of the present disclosure are directed to coextruded multilayer films comprising a comprising a plurality of layers, wherein at least one layer comprises the thermoplastic adhesive composition, the thermoplastic adhesive composition comprising: at least one maleic anhydride-grafted ethylene-based polymer; at least one at least one ethylene/α-olefin/non-conjugated diene interpolymer having a molecular weight distribution (MWD) ≥ 2.5, wherein MWD = Mw/Mn, wherein Mw is weight averaged molecular weight and Mn is number averaged molecular weight, which are both determined by gel permeation chromatography; and a very low density polyethylene (VLDPE) having a density in the range 0.885 to 0.915 grams/cm3.