Optical Laminate Structure for Humidity-Resistant Reflection Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical laminates using photo-alignment layers exhibit durability issues under high-temperature and high-humidity environments, leading to surface reflection unevenness due to resin layer deformation.
Innovation Solution
The optical laminate is configured with specific relationships between the storage elastic modulus of the pressure sensitive adhesive layer and the storage elastic modulus and moist heat strain of the resin layer, adhering to Expressions (1-1) and (1-2), ensuring the laminate's resilience against such environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a photo-alignment layer is used in the optical laminate, then the alignment of liquid crystal compound is achieved, but the durability against high-temperature and high-humidity environment deteriorates due to resin layer deformation
Solution Approach 1:
The patent changes the physical parameters of the pressure-sensitive adhesive layer by controlling its storage elastic modulus to be within a specific range (0.1 to 10 MPa) and adjusting its thickness (1 to 10 μm). These parameter changes enable the adhesive layer to provide appropriate cushioning effect, preventing resin layer deformation under high-temperature and high-humidity conditions while maintaining the photo-alignment layer's alignment function.
Solution Approach 2:
The patent creates a composite structure consisting of multiple layers with different functions: the photo-alignment layer (providing alignment function), the pressure-sensitive adhesive layer (providing mechanical cushioning), and the resin layer (providing structural support). This composite material approach allows each layer to contribute its specific properties, resolving the contradiction between alignment performance and environmental durability.
2Adaptability or versatility
If the optical laminate is exposed to high-temperature and high-humidity environment, then the operational conditions are met, but surface reflection unevenness occurs due to resin layer deformation
Solution Approach 1:
The patent implements beforehand cushioning by introducing a pressure-sensitive adhesive layer with specifically controlled mechanical properties (storage elastic modulus of 0.1 to 10 MPa) between the resin layer and the photo-alignment layer. This layer acts as a cushion that prevents deformation of the resin layer when exposed to high-temperature and high-humidity environments, thereby maintaining surface reflection uniformity and preventing the harmful effects of deformation before they occur.
3Strength
If the storage elastic modulus of the pressure sensitive adhesive layer is increased, then the bonding strength is improved, but the cushioning effect against resin layer deformation is reduced
Solution Approach 1:
The patent precisely controls the storage elastic modulus of the pressure-sensitive adhesive layer within the range of 0.1 to 10 MPa. This parameter optimization ensures that the adhesive layer has sufficient bonding strength to hold the layers together while simultaneously maintaining enough elasticity to provide cushioning effect, preventing resin layer deformation under thermal and humidity stress.
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 laminate maintains structural integrity and prevents surface reflection unevenness, enhancing durability and performance in adverse conditions.
Implementation Method 1
a storage elastic modulus Ep of the pressure sensitive adhesive layer 1 and a storage elastic modulus Ea and a moist heat strain δa of the resin layer satisfy Expression (1-1)
Implementation Method 2
a photo-alignment layer formed of a composition for forming an alignment layer containing a cinnamoyl compound that contains a functional group having an ethylenically unsaturated double bond
Implementation Method 3
the light absorption anisotropic layer contains a dichroic substance
Data Source
AI summary
An optical laminate with excellent durability and an image display device formed of the optical laminate. The optical laminate includes a pressure sensitive adhesive layer 1, a specific laminate including a resin layer and a light absorption anisotropic layer, and a pressure sensitive adhesive layer 2 in order, in which the light absorption anisotropic layer contains a dichroic substance, the pressure sensitive adhesive layer 1 is adjacent to the resin layer of the specific laminate, and a storage elastic modulus Ep of the pressure sensitive adhesive layer 1 and a storage elastic modulus Ea and a moist heat strain δa of the resin layer satisfy Expression (1-1) ¼(3×Ep/Ea)2/3>δa.