Polymerizable Compound for Reversed-Wavelength Dispersion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polymerizable compounds used in liquid crystal displays and organic EL devices face challenges in maintaining good liquid crystal properties, alignment properties, solubility, and optical stability, particularly when introducing vertical units to achieve reversed-wavelength dispersion, which can lead to degradation in solubility and optical stability.
Innovation Solution
A polymerizable compound represented by General Formula (I) is developed, which includes specific polymerizable functional groups, spacer groups, and aromatic hydrocarbon groups to enhance liquid crystal and alignment properties while maintaining solubility and optical stability, allowing for the production of optically anisotropic bodies with improved reversed-dispersion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a vertical unit is introduced into the polymerizable compound to achieve reversed-wavelength dispersion, then the optical property is improved, but the liquid crystal property and alignment property are degraded
Solution Approach 1:
The molecule is divided into distinct functional segments: a vertical unit (cyclohexylidene or indanone group) for optical property, a mesogenic unit for liquid crystal property, and a polymerizable unit for alignment property. This segmentation allows each unit to contribute its specific function without interfering with others, resolving the contradiction between improved optical property and maintained liquid crystal/alignment properties
Solution Approach 2:
The vertical unit is positioned at specific locations within the molecule (at the para-position of the mesogenic unit or at the terminal position of the polymerizable unit) to locally provide the desired optical property while the rest of the molecule maintains its liquid crystal and alignment properties. This localized placement ensures that the vertical unit's effect on optical property does not propagate negatively to other functional properties
2Illumination intensity
If a vertical unit is introduced into the polymerizable compound, then the optical property is improved, but the solubility in solvent is degraded
Solution Approach 1:
A flexible spacer unit (alkylene group with 1-10 carbon atoms) is introduced as an intermediary between the vertical unit and the mesogenic unit. This spacer acts as a mediator that improves solubility by providing flexibility and reducing molecular packing, while still allowing the vertical unit to exert its optical effect and the mesogenic unit to maintain liquid crystal properties
Solution Approach 2:
The polymerizable compound is designed as a composite molecular structure combining four distinct functional units (vertical unit, spacer unit, mesogenic unit, and polymerizable unit) in specific arrangements. This composite approach allows each unit to contribute its specific property (optical, solubility, liquid crystal, and alignment properties respectively) without the negative effects of the other units, achieving a balance among all required properties
3Illumination intensity
If a vertical unit is introduced into the polymerizable compound, then the optical property is improved, but the absorption spectrum shifts to longer wavelengths which degrades optical stability
Solution Approach 1:
The chemical structure parameters of the vertical unit are specifically optimized by selecting from cyclohexylidene or indanone groups, which have been determined to provide reversed-wavelength dispersion while maintaining absorption spectra in ranges that preserve optical stability. This parameter optimization ensures that the vertical unit delivers the desired optical property without shifting absorption to problematic longer wavelengths
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 enables the production of optically anisotropic bodies with excellent optical properties, enabling liquid crystal display elements and organic EL devices with increased viewing angles and improved stability.
Implementation Method 1
causing polymerization using ultraviolet radiation or heat
Implementation Method 2
the wavelength dispersion of birefringence (Δn) is small or reversed
Data Source
AI summary
It is an object of the present invention to provide a polymerizable compound having a good liquid crystal property, a good alignment property, sufficient solubility in solvents, high preservation stability in a solution state, and high optical stability; a composition including the polymerizable compound; a polymer produced by polymerizing the polymerizable compound, such as a resin produced using the polymerizable compound; an optically anisotropic body including the polymer; and a liquid crystal display element and an organic EL device that include the optically anisotropic body. As a result of conducting intensive studies in order to achieve the above object, the compound represented by General Formula (I) is developed.