Polyolefin Adhesive Composition for Low-Temperature Pouch Lamination
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Solution Overview
Problem
Existing adhesive compositions for lithium-ion battery packaging materials face challenges with moldability, adhesion, heat resistance, and durability, particularly when exposed to high temperatures and mechanical stress, leading to potential electrolyte leakage and delamination.
Innovation Solution
A blend of two modified polyolefins with different melting points and a styrene-based or olefin-based thermoplastic resin, along with a curing agent, is used to create an adhesive composition that exhibits excellent adhesion to polyolefin and metal substrates, providing improved followability and resistance to electrolyte solutions, even at low temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a conventional adhesive composition is used to bond packaging materials, then adhesion between layers is achieved, but the adhesive layer cannot follow substrate extension during pouch formation, causing peeling and poor moldability
Solution Approach 1:
The adhesive composition uses a composite system combining modified polyolefin (A1) with low melting point for flexibility and followability, modified polyolefin (A2) with high melting point for thermal stability, and thermoplastic resin (B) for enhanced adhesion. This composite formulation allows the adhesive to follow substrate extension during pouch formation while maintaining strong bonding strength.
2Strength
If the adhesive is processed at high temperature to improve bonding, then adhesion strength increases, but the adhesive layer breaks due to pulling force and heat resistance deteriorates
Solution Approach 1:
The invention optimizes the melting point parameters of the adhesive components. Modified polyolefin (A1) has a low melting point (50-100°C) allowing processing at lower temperatures, while modified polyolefin (A2) has a high melting point (100-160°C) providing heat resistance. The melting point difference between (A1) and (A2) is controlled at 30-50°C to balance processability and thermal stability, enabling bonding without breaking under pulling force.
3Ease of manufacture
If the adhesive composition is simplified to improve ease of manufacture, then production becomes easier, but adhesion to both polyolefin and metal substrates deteriorates
Solution Approach 1:
The adhesive composition is designed with multi-functionality to bond both polyolefin resin substrates and metal substrates effectively. Modified polyolefin components provide compatibility with polyolefin substrates, while the thermoplastic resin (B) and acid value control (2-50 mgKOH/g) enable adhesion to metal substrates. This universal bonding capability is achieved within a single composition formulation that maintains ease of manufacture.
4Weight of moving object
If the adhesive layer is made thinner to reduce packaging material weight, then weight reduction is achieved, but electrolyte solution penetration increases causing delamination
Solution Approach 1:
The adhesive composition uses a composite system where modified polyolefin (A1) and (A2) provide baseline electrolyte resistance, while thermoplastic resin (B) enhances barrier properties. The acid-modified components (acid value 2-50 mgKOH/g) improve chemical resistance to electrolyte solutions. This composite formulation maintains excellent electrolyte solution resistance even in thin adhesive layers, preventing delamination while reducing packaging material weight.
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 adhesive composition demonstrates enhanced moldability, adhesion, electrolyte solution resistance, and heat resistance, ensuring durability and reliability of lithium-ion battery packaging materials under various environmental conditions.
Implementation Method 1
an adhesive composition comprising a modified polyolefin (A1); a modified polyolefin (A2) containing propylene in an amount of 30 mol% or more and having a melting point higher than that of the modified polyolefin (A1); and a thermoplastic resin (B)
Implementation Method 2
the adhesion of the adhesives after curing in a high-temperature environment may be poor, or breakage may occur due to pulling force
Data Source
AI summary
Provided is an adhesive composition that is capable of bonding and aging at low temperature, and that has excellent adhesion, electrolyte solution resistance, heat resistance, durability, and moldability. The adhesive composition comprises a modified polyolefin (A1), a modified polyolefin (A2) having a melting point higher than that of the modified polyolefin (A1), and a thermoplastic resin (B).