Multilayer Optical Film UV Absorber Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current polarizing plates in image display devices face issues with moisture resistance, heat resistance, and ultraviolet light absorption, leading to degradation in performance and optical properties due to the use of triacetyl cellulose films and known ultraviolet absorbers, which decompose at high temperatures and cause yellowing and contamination.
Innovation Solution
A multilayer optical film is developed using a thermoplastic acrylic resin composition with specific ranges of triazine-based and other ultraviolet absorbers in different layers, providing superior heat resistance and ultraviolet light absorptivity while preventing migration and pyrolysis, and maintaining economic feasibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If known ultraviolet absorbers (benzotriazole-based, benzophenone-based, etc.) are added to acrylic film, then ultraviolet light absorbing capability is improved, but the ultraviolet absorbers decompose during high temperature processing, causing yellowing and contamination
Solution Approach 1:
The patent divides the ultraviolet absorption function across multiple layers with different absorber types. The first and third layers use benzotriazine-based absorbers for UV-B absorption, while the second layer uses triazole-based absorbers for UV-A absorption. This segmentation allows each layer to use absorbers optimized for specific wavelength ranges, reducing overall decomposition and yellowing during high-temperature processing.
Solution Approach 2:
Different ultraviolet absorbers are placed in different layers based on their specific absorption characteristics and thermal stability. The benzotriazine-based absorbers are positioned in outer layers where they provide UV-B protection, while triazole-based absorbers are placed in the intermediate layer for UV-A protection. This local optimization ensures each absorber operates in its most effective environment.
2Object-affected harmful factors
If excessive amount of benzotriazine-based ultraviolet absorber is added to achieve high UV-B absorption, then ultraviolet light absorptivity is improved, but migration phenomenon occurs during casting-rolling process causing contamination on casting roll
Solution Approach 1:
The patent segments the ultraviolet absorption function by using benzotriazine-based absorbers only in the first and third layers at controlled concentrations (0.01-2.0 parts by weight per 100 parts acrylic resin). This prevents excessive concentration in any single layer, thereby reducing migration during the casting-rolling process while maintaining effective UV-B absorption across the multilayer structure.
Solution Approach 2:
The intermediate second layer acts as a buffer between the outer layers containing benzotriazine-based absorbers. This layer uses triazole-based absorbers which have different migration characteristics, effectively isolating the benzotriazine absorbers and preventing their migration to the casting roll while maintaining overall UV protection.
3Object-affected harmful factors
If large quantity of ultraviolet absorbers with low molecular weight and low glass transition temperature are added, then ultraviolet light absorptivity is improved, but glass transition temperature of resin composition is significantly lowered, degrading heat resistance properties
Solution Approach 1:
The patent carefully controls the concentration parameters of ultraviolet absorbers in each layer (0.01-2.0 parts by weight for benzotriazine-based, 0.1-5.0 parts by weight for triazole-based per 100 parts acrylic resin). This parameter optimization ensures sufficient ultraviolet absorption while preventing excessive reduction in glass transition temperature, thereby maintaining heat resistance properties.
Solution Approach 2:
The patent creates a composite multilayer structure combining acrylic resin with different types of ultraviolet absorbers in specific proportions. This composite approach allows the system to achieve comprehensive ultraviolet protection (both UV-A and UV-B) while the distributed architecture prevents any single absorber from excessively lowering the overall glass transition temperature of the material.
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 multilayer optical film achieves excellent heat resistance, ultraviolet light absorptivity, and mechanical strength, preventing contamination and yellowing, and reducing manufacturing costs, thus enhancing the durability and performance of polarizing plates.
Implementation Method 1
it is known that a benzotriazole-based compound, a benzophenone-based compound, a benzotriazine-based compound, a cyano acrylate-based compound, a salicylic acid-based compound or the like may be used as the ultraviolet absorber
Implementation Method 2
since a majority of known ultraviolet absorbers may decompose during a high temperature processing operation, ultraviolet light absorbing capability may be deteriorated and further, a resin and a film may be yellowed due to pyrolysis of the ultraviolet absorbers
Data Source
AI summary
The present disclosure relates to a multilayer optical film including a first film layer formed of a thermoplastic acrylic resin composition including 0.01 to 2.0 parts by weight of a triazine-based ultraviolet absorber; a second film layer formed of a thermoplastic acrylic resin composition including 0.1 to 5.0 parts by weight of at least one ultraviolet absorber selected from a group consisting of a triazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, an oxanilide-based ultraviolet absorber and a cyanoacrylate-based ultraviolet absorber; and a third film layer formed of the thermoplastic acrylic resin composition including 0.01 to 2.0 parts by weight of the triazine-based ultraviolet absorber, with respect to 100 parts by weight of the thermoplastic acrylic resin composition, a method of manufacturing the same, and a polarizing plate including the same.