Polymerizable Polar Compound for Liquid Crystal Alignment and Response Time
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Solution Overview
Problem
Current liquid crystal display devices face challenges in achieving high chemical stability, effective liquid crystal molecule alignment, solubility, and voltage holding ratio, while also requiring a wide temperature range, short response time, and long service life.
Innovation Solution
A compound with polymerizable and polar groups is introduced into a liquid crystal composition, which, when irradiated with ultraviolet light, forms a polymer network that stabilizes liquid crystal alignment and improves response time, allowing for a wide temperature range and high voltage holding ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a polymerizable compound is added to improve alignment and response time, then alignment capability and response time are improved, but chemical stability and voltage holding ratio deteriorate
Solution Approach 1:
The invention divides the functional requirements by using separate compounds: a polymerizable compound (acrylate or methacrylate) for alignment and response time improvement, and a distinct polar compound with specific structures (compounds 1-34) for voltage holding ratio maintenance. This segmentation allows each compound to optimize its specific function without compromising the other.
Solution Approach 2:
The invention creates a composite liquid crystal composition containing multiple types of compounds (polymerizable compound, polar compound of formula 1-34, and liquid crystal compounds) that work synergistically. The polar compounds with specific structural features provide both alignment capability and high voltage holding ratio, while the polymerizable compound forms a polymer network to improve response time, achieving a composite effect that satisfies multiple contradictory requirements.
2Speed
If viscosity is reduced to improve response time, then response time is improved, but alignment capability and stability deteriorate
Solution Approach 1:
The invention uses polymerizable compounds that form a polymer network structure within the liquid crystal composition before the device operates. This preliminary polymer network formation provides stable alignment guidance for liquid crystal molecules, ensuring alignment capability is maintained even when viscosity is reduced for faster response times.
Solution Approach 2:
The composite composition combines low-viscosity liquid crystal compounds with polymerizable and polar compounds. The polar compounds (formula 1-34) provide strong alignment capability through their molecular structure, while the overall composition maintains low viscosity for fast response, achieving both speed and stability simultaneously.
3Reliability
If chemical stability is improved to extend service life, then service life is extended, but solubility and alignment capability deteriorate
Solution Approach 1:
The invention modifies molecular parameters of the polar compounds by introducing specific structural features (compounds 1-34 with particular ring structures, substituent groups, and molecular configurations) that balance chemical stability with solubility. These parameter changes ensure the compounds remain chemically stable for long service life while maintaining adequate solubility in the liquid crystal composition for effective alignment.
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 compound enhances the chemical stability and solubility of the liquid crystal composition, enabling a liquid crystal display device with improved alignment, reduced viscosity, and extended service life, along with a short response time and low threshold voltage.
Implementation Method 1
when irradiated with ultraviolet light, forms a polymer network that stabilizes liquid crystal alignment
Data Source
AI summary
Provided are a compound represented by formula (1). For example, R1, R2 and R3 are alkyl having 1 to 15 carbons; ring A1 and ring A3 are cyclohexylene or phenylene, ring A3 is 1,4-cyclohexylene or phenylene; Z1 and Z5 are a single bond or alkylene having 1 to 10 carbons; a is 0, 1, 2, 3 or 4; c, d and e are 0, 1, 2, 3 or 4; and P1 to P3 are a polymerizable group represented by formula (P-1); wherein M1 and M2 are hydrogen or alkyl having 1 to 5 carbons; and R4 is a polar group represented by formulas (1a) to (1c) : wherein Sp5 and Sp6 are a single bond or alkylene having 1 to 10 carbons; S1 is >CH-, and S2 is >C<; and X1 is -OH.