Liquid Crystal Composition Polymerizable Compound Pretilt Angle Control
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Solution Overview
Problem
PSA liquid crystal display devices face challenges with slow polymerization rates of polymerizable compounds, leading to residual polymerizable compounds and display defects like image-sticking due to changes in pretilt angles and low manufacturing efficiency.
Innovation Solution
A liquid crystal composition with a polymerizable compound having a specific chemical structure, represented by the general formula (I), which allows for a high polymerization rate, controlling pretilt angles, and reducing residual polymerizable compounds, thereby improving manufacturing efficiency and display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a polymerizable compound with conventional structure (terphenyl or acetylene) is used to increase polymerization rate, then the polymerization rate increases and residual polymerizable compound decreases, but display defects occur due to change in pretilt angle of liquid crystal molecules
Solution Approach 1:
The patent changes the chemical structure parameters of the polymerizable compound by introducing a specific molecular formula (I) with particular structural features (cyclic carbonate group, specific substituent patterns) to achieve optimal polymerization rate while maintaining display quality. This parameter optimization resolves the contradiction between fast polymerization and pretilt angle stability.
Solution Approach 2:
The patent creates a composite liquid crystal composition containing the polymerizable compound of formula (I) combined with specific liquid crystal compounds having defined structural characteristics. This composite approach enables both high polymerization rate and stable pretilt angle control, resolving the trade-off between productivity and reliability.
2Quantity of substance
If strong ultraviolet irradiation is applied for extended periods to decrease residual polymerizable compound, then the amount of residual polymerizable compound decreases, but manufacturing efficiency decreases and liquid crystal composition degrades
Solution Approach 1:
The patent optimizes the chemical structure parameters of the polymerizable compound to achieve rapid polymerization kinetics, allowing the reaction to complete in short irradiation time. This eliminates the need for extended strong UV irradiation, thereby maintaining high manufacturing efficiency while minimizing residual monomer.
Solution Approach 2:
The patent designs the polymerizable compound with pre-optimized molecular structure (formula I) that enables fast and complete polymerization under mild UV conditions. This preliminary structural design ensures that the polymerization reaction proceeds to completion quickly, avoiding the need for prolonged irradiation and preventing liquid crystal degradation.
3Productivity
If short ultraviolet irradiation time is used, then manufacturing efficiency increases, but the amount of residual polymerizable compound increases causing image-sticking display defect
Solution Approach 1:
The patent optimizes the molecular structure parameters of the polymerizable compound (formula I) to achieve extremely fast polymerization rate, enabling complete reaction within short UV irradiation time. This resolves the contradiction by making both short irradiation time and low residual monomer compatible.
Solution Approach 2:
The patent formulates a composite liquid crystal composition with specific ratios of polymerizable compound and liquid crystal compounds, where the polymerizable compound's structure (formula I) is specifically designed to polymerize rapidly and completely. This composite formulation achieves both high manufacturing efficiency and high display quality with minimal image-sticking.
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 composition achieves a high-speed response, minimal display defects, and efficient production with a high voltage holding ratio, maintaining refractive index anisotropy and nematic phase-isotropic liquid phase transition temperature, while optimizing energy costs.
Implementation Method 1
polymerizing the polymerizable compound by ultraviolet irradiation to fix the alignment of liquid crystal molecules
Data Source
AI summary
[Object] An object of the present invention is to provide a liquid crystal composition containing a polymerizable compound for use in the manufacture of a PSA or PSVA liquid crystal display device. The polymerizable compound has a sufficiently high polymerization rate. The PSA or PSVA liquid crystal display device has few or no display defects due to a change in pretilt angle, has an adequate pretilt angle, and has high responsiveness. The present invention also provides a liquid crystal display device having the liquid crystal composition.[Solution] The object is achieved by using a liquid crystal composition containing one or two or more polymerizable compounds represented by the general formula (I).