Liquid Crystal Alignment Film Side Chain Structures for Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional reverse PDLC devices face challenges with low adhesion between the liquid crystal layer and the vertical liquid crystal alignment film, which affects the vertical alignment property and optical performance, requiring high amounts of polymerizable compounds that impair transparency and scattering properties.
Innovation Solution
A liquid crystal display device using a vertical liquid crystal alignment film obtained from a liquid crystal aligning agent with specific side chain structures, which enhances adhesion and alignment, achieved through a polymerization reaction with ultraviolet rays, improving both transparency and scattering properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vertical liquid crystal alignment film is used to achieve high vertical alignment property, then the adhesion to liquid crystal layer is improved, but the transparency and scattering property are significantly decreased due to the need for large amounts of polymerizable compounds
Solution Approach 1:
The invention changes the chemical structure parameters of the polymerizable compound by specifying particular molecular structures (formula 1 with specific R1-R6 groups, formula 2 with specific R7-R12 groups) and their compositional ratios (formula 3), thereby achieving both high adhesion and good optical properties without the need for large amounts of generic polymerizable compounds
Solution Approach 2:
The invention uses a composite liquid crystal composition containing both the specifically structured polymerizable compounds (formulas 1 and 2) and liquid crystal compounds, where the composite achieves synergistic effects providing both adhesion enhancement and optical performance
2Reliability
If a polymerizable compound is incorporated in a large amount to increase adhesion, then the adhesion between liquid crystal layer and alignment film is improved, but the vertical alignment property is impaired
Solution Approach 1:
The invention specifies precise structural parameters and compositional ratios of the polymerizable compounds (formulas 1, 2, and 3) to achieve the optimal balance between adhesion and vertical alignment property, avoiding the need for large amounts of polymerizable compounds that would impair alignment
3Stability of the object's composition
If a conventional vertical liquid crystal alignment film is used, then the film is highly hydrophobic, but the adhesion to liquid crystal layer tends to be low
Solution Approach 1:
The invention modifies the chemical parameters of the polymerizable compounds by introducing specific functional groups (formula 1 with R1-R6, formula 2 with R7-R12) that can interact with the hydrophobic alignment film surface, thereby improving adhesion while maintaining the film's hydrophobic character
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 high adhesion and stable vertical alignment, ensuring favorable optical properties with improved transparency when no voltage is applied and scattering when voltage is applied, addressing the limitations of conventional devices.
Implementation Method 1
a liquid crystal composition containing a polymerizable compound which undergoes polymerization by ultraviolet rays
Implementation Method 2
liquid crystal molecules are aligned in an electric field direction, whereby light is transmitted
Implementation Method 3
liquid crystal molecules are randomly aligned, and is in a transmission state when a voltage is applied since liquid crystal molecules are aligned in an electric field direction
Implementation Method 4
a liquid crystal alignment film to vertically align a liquid crystal
Data Source
AI summary
To provide a liquid crystal display device, in which the vertical alignment property of the liquid crystal is high, favorable transparency when no voltage is applied and favorable scattering property when a voltage is applied are achieved, and the adhesion between the liquid crystal layer and the vertical liquid crystal alignment film is high. A liquid crystal display device, which comprises a liquid crystal layer formed by disposing a liquid crystal composition containing a polymerizable compound which undergoes a polymerization reaction by ultraviolet rays, between a pair of substrates provided with an electrode, and irradiating the liquid crystal composition with ultraviolet rays and curing it in such a state that the liquid crystal composition partly or entirely shows liquid crystallinity, and at least one of the substrates being provided with a liquid crystal alignment film to vertically align a liquid crystal, wherein the liquid crystal alignment film is a liquid crystal alignment film obtained from a liquid crystal aligning agent containing a polymer having a first side chain structure and a second side chain structure.