Polyamide Window Film for Flexible Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional window films for flexible display devices face challenges with refractive index differences leading to interference phenomena and rainbow effects, and require complex lamination processes, which increase manufacturing costs and complexity.
Innovation Solution
A window film with a light transmitting substrate made from a polyamide containing specific structural units and a hard coating layer, which reduces refractive index differences and improves wavelength dispersion properties, eliminating interference and enhancing optical and mechanical properties without the need for lamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a plastic film is used to substitute glass substrate, then flexibility and impact resistance are improved, but optical properties and mechanical hardness deteriorate
Solution Approach 1:
The patent uses a composite structure consisting of a polyamide film base layer and a hard coating layer. The polyamide film provides flexibility and impact resistance, while the hard coating layer (containing silica, zirconia, or titania particles) provides enhanced hardness and improved optical properties. This composite material approach resolves the contradiction by combining materials with complementary properties.
2Strength
If conventional polyimide or poly(amide-imide) is used as light transmitting substrate, then mechanical properties are maintained, but refractive index difference causes interference phenomena and rainbow effects
Solution Approach 1:
The patent changes the refractive index parameter of the light transmitting substrate by selecting polyamide with specific refractive index (1.50-1.65) that closely matches the hard coating layer's refractive index (1.60-1.75). This parameter optimization reduces the refractive index difference to less than 0.3, thereby minimizing interference phenomena and rainbow effects while maintaining mechanical properties.
3Reliability
If lamination process is used to combine multiple layers, then optical properties are improved, but manufacturing complexity and costs increase
Solution Approach 1:
The patent combines the light transmitting substrate and hard coating layer into a single integrated structure where the hard coating layer is directly formed on the polyamide film surface through coating processes. This merging of functions into a unified layered structure achieves improved optical properties and hardness while simplifying the manufacturing process compared to separate lamination of pre-made films.
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 provides improved optical properties, reduced interface interference, and enhanced visibility with a single-layer film production, simplifying the manufacturing process and reducing costs while maintaining high mechanical and heat resistance.
Implementation Method 1
A window film with a light transmitting substrate made from a polyamide containing specific structural units and a hard coating layer, which reduces refractive index differences and improves wavelength dispersion properties, eliminating interference and enhancing optical and mechanical properties
Implementation Method 2
Conventional window films for flexible display devices face challenges with refractive index differences leading to interference phenomena and rainbow effects
Data Source
AI summary
Disclosed is a window film for a display device including a light transmitting substrate including a polyamide including a structural unit represented by Chemical Formula 1 and a structural unit represented by Chemical Formula 2, and a hard coating layer laminated on one surface of the light transmitting substrate:in Chemical Formula 1 and Chemical Formula 2, each of A1, A2, B, and D is the same as defined in the detailed description.