Polymerizable Compound for Liquid Crystal Display
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Solution Overview
Problem
Current polymerizable compounds used in liquid crystal display devices face a trade-off between solubility and polymerization reactivity, with high solubility often leading to reduced reactivity and vice versa, and existing liquid crystal compositions struggle to achieve a balance of physical properties such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy, large dielectric anisotropy, and long service life.
Innovation Solution
A polymerizable compound with three or four non-condensed rings, featuring three or more polymerizable groups where at least one group is bonded to a ring not at both terminals, is developed. This compound is incorporated into a liquid crystal composition, allowing for high polymerization reactivity, solubility, and balanced physical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the solubility of polymerizable compound in liquid crystal composition is improved, then the compound can be better incorporated into the composition, but polymerization reactivity tends to reduce
Solution Approach 1:
The patent applies parameter changes by modifying the molecular structure of polymerizable compounds (changing ring configurations from condensed to non-condensed, adjusting the number and positioning of polymerizable groups) to achieve optimal balance between solubility and reactivity. This structural parameter optimization allows the compound to maintain high solubility in liquid crystal composition while preserving sufficient polymerization reactivity for effective crosslinking.
2Reliability
If a polymer is formed in the liquid crystal composition to shorten response time and improve image persistence, then display performance is enhanced, but the liquid crystal composition becomes more complex and may affect other physical properties
Solution Approach 1:
The patent employs composite materials by creating a hybrid system where polymerizable compounds are integrated into the liquid crystal composition. The polymerizable compound acts as a dual-function component: it maintains the liquid crystal's optical properties while providing polymerization capability for image persistence. The resulting composite structure combines the advantages of both liquid crystal molecules (optical anisotropy, response speed) and polymer networks (stability, image persistence) without requiring separate additive systems.
3Temperature
If the liquid crystal composition is optimized for high maximum temperature and low minimum temperature of nematic phase, then the operating temperature range is extended, but other physical properties such as viscosity and dielectric anisotropy may be compromised
Solution Approach 1:
The patent applies local quality by using polymerizable compounds with specific molecular structures (three or four non-condensed rings with three or more polymerizable groups) that provide localized functional properties. The polymerization creates a three-dimensional network structure that selectively enhances certain properties (image persistence, temperature stability) while maintaining other properties (response time, viscosity) through the liquid crystal matrix. This localized functional differentiation allows independent optimization of different performance aspects.
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 results in a liquid crystal composite with improved polymerization reactivity, high conversion ratio, and enhanced solubility, leading to a liquid crystal display device with a wide temperature range, short response time, high voltage holding ratio, low threshold voltage, large contrast ratio, and long service life.
Implementation Method 1
The display device is irradiated with ultraviolet light in a state in which voltage is applied between electrodes, and the polymerizable compound is polymerized to form the polymer in the liquid crystal composition.
Data Source
AI summary
To provide a polymerizable compound having high polymerization reactivity, a high conversion ratio and high solubility in a liquid crystal composition, a polymerizable composition containing the compound, a liquid crystal composite prepared from the composition and a liquid crystal display having the composite. The invention provides a polymerizable compound, the polymerizable compound being a compound which consists of three or four rings in a serial shape and not being mutually condensed, having three or more polymerizable groups, wherein at least one of the polymerizable groups thereof is combined with a ring which is not an either terminal of the three or four rings. The invention provides a polymerizable composition containing the polymerizable compound above and a liquid crystal composition. The invention provides liquid crystal composite prepared from the polymerizable composition above, and a liquid crystal display device thereof.