Colored Battery Packaging Laminate That Resists Cracking and Peeling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Packaging materials for batteries, particularly those colored black, tend to experience partial cracking and peeling during molding and sealing, and when exposed to harsh environments like high temperature and high humidity, due to the brittleness of print layers containing carbon black or other pigments, which affects their uniform coloration and structural integrity.
Innovation Solution
A packaging material configuration featuring a heat-resistant resin layer, a thermoplastic resin layer, a metal foil layer, and adhesive layers with a specific composition and thickness, including a color adhesive agent composition with 2-5 μmass % pigment content, a two-part curing type polyester urethane resin, and a chemical conversion coating on the metal foil layer, to prevent peeling and maintain uniform coloration and bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a print layer containing carbon black is provided on the inner surface of the outer resin layer to color the battery in black, then the battery achieves uniform black coloration, but the print layer partially cracks and peels off during molding and sealing
Solution Approach 1:
The patent extracts the coloring function from a separate print layer and integrates it into the outer resin layer itself by incorporating carbon black pigment directly into the resin material. This eliminates the need for a distinct print layer that is prone to cracking and peeling, while maintaining uniform black coloration throughout the outer layer.
Solution Approach 2:
The patent combines the coloring function with the structural outer resin layer by mixing carbon black pigment into the resin material. This merging of the print layer's coloring role with the outer layer's structural role creates a unified component that maintains both coloration uniformity and structural integrity during molding and sealing processes.
2Illumination intensity
If the packaging material is colored with pigments to achieve uniform appearance, then the aesthetic requirement is met, but the material becomes brittle and peels in harsh environments such as high temperature and high humidity
Solution Approach 1:
The patent removes the vulnerable print layer that contains pigments and instead incorporates the pigment directly into the outer resin layer material. This extraction of the problematic separate layer eliminates the brittleness and peeling issues that occur in harsh environments, while preserving the uniform appearance through direct pigment integration.
Solution Approach 2:
The patent creates a composite outer resin layer by combining the resin material with carbon black pigment at the material formulation stage. This composite structure ensures uniform distribution of the pigment throughout the resin matrix, providing both aesthetic uniformity and environmental resistance without the brittleness associated with separate print layers.
3Temperature
If a black body material layer is provided between the metal foil layer and the outer layer film to promote heat radiation, then heat radiation is enhanced, but the additional layer increases the complexity of the packaging material structure
Solution Approach 1:
The patent combines the heat radiation function with the outer resin layer by incorporating carbon black pigment into it. Since carbon black is an excellent heat radiating material, this merging of the black body material function with the outer layer eliminates the need for a separate black body layer, maintaining heat radiation performance while simplifying the overall structure.
Solution Approach 2:
The outer resin layer is given multiple functions: it provides structural protection, achieves uniform black coloration, and promotes heat radiation through carbon black incorporation. This multi-functionality eliminates the need for separate dedicated layers for each function, reducing structural complexity while maintaining all required performance characteristics.
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 solution ensures that the packaging material maintains uniform coloration and bonding strength during molding and sealing, and remains intact even in harsh environments, providing high formability, heat resistance, and corrosion resistance.
Implementation Method 1
a two-part curing type polyester urethane resin composed of a polyester resin as a main agent and a polyfunctional isocyanate compound as a curing agent
Implementation Method 2
a chemical conversion coating on the metal foil layer
Data Source
AI summary
A packaging material for molding includes a heat resistant resin layer as an outer layer; a thermoplastic resin layer as an inner layer; a metal foil layer disposed between the heat resistant resin layer and the thermoplastic resin layer; a first adhesive layer disposed between the metal foil layer and the heat resistant resin layer; and a second adhesive layer disposed between the metal foil layer and the thermoplastic resin layer. The first adhesive layer is composed of a color adhesive agent composition containing a color pigment and an adhesive agent. The color adhesive agent composition contains a color pigment of 2 mass % or more and less than 5 mass % with respect to a solid component. The first adhesive layer is a coating of the color adhesive agent composition of 5 g/m2 to 10 g/m2. The first adhesive layer contains a color pigment of 0.25 g/m2 to 0.49 g/m2.