Liquid Crystal Composition for Suppressed Twisted Angle Variation
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Solution Overview
Problem
The production of optically anisotropic layers for display devices faces challenges in maintaining consistent twisted angles of liquid crystal compounds, leading to variations in optical performance due to the use of photosensitive chiral agents whose helical twisting power changes with light exposure.
Innovation Solution
A liquid crystal composition is developed comprising a photosensitive optically active compound with a high molar absorption coefficient and a non-photosensitive optically active compound, where the mass content ratio of the photosensitive compound is less than 0.01, and the helical twisting power changes significantly upon light exposure, while the non-photosensitive compound maintains stability, forming an optically anisotropic layer with suppressed twisted angle variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a photosensitive chiral agent is used to produce an optically anisotropic layer, then the helical twisting power changes upon light irradiation enabling optical control, but the twisted angle of liquid crystal compound varies in the in-plane direction leading to inconsistent optical performance
Solution Approach 1:
The patent uses a photosensitive chiral agent that undergoes localized structural changes upon light irradiation, creating spatially varying helical twisting power. This enables different regions of the liquid crystal composition to exhibit different optical properties, achieving in-plane optical control while maintaining uniform twisted angles through the specific combination of photosensitive and non-photosensitive chiral agents
Solution Approach 2:
The invention combines photosensitive and non-photosensitive chiral agents in a liquid crystal composition. The photosensitive component (0.01-5 wt%) provides light-responsive helical twisting power changes for optical control, while the non-photosensitive component (94.99-99.99 wt%) maintains stable helical twisting power to ensure uniform twisted angles across the in-plane direction, achieving both adaptability and manufacturing precision
2Reliability
If a photosensitive chiral agent is used to produce an optically anisotropic layer, then optical performance can be controlled by light exposure, but the helical twisting power changes lead to variations in twisted angle
Solution Approach 1:
The patent exploits changes in the helical twisting power parameter of the photosensitive chiral agent upon light irradiation. The photosensitive component undergoes photoisomerization or photochemical reactions that alter its molecular structure and consequently its helical twisting power, enabling dynamic control of optical properties while the non-photosensitive component provides compositional stability
Solution Approach 2:
The non-photosensitive chiral agent acts as an intermediary that stabilizes the overall helical twisting power of the composition. It compensates for the fluctuations caused by the photosensitive component, ensuring that the net helical twisting power remains sufficiently stable to maintain uniform twisted angles while still allowing optical control through the photosensitive portion
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 effectively forms an optically anisotropic layer with reduced twisted angle variations, enhancing the optical performance and stability of the layer, suitable for applications in circularly polarizing plates for organic EL displays.
Implementation Method 1
a photosensitive optically active compound whose helical twisting power changes upon irradiation with light
Implementation Method 2
a liquid crystal composition comprising a liquid crystal compound, an optically active compound A which is a photosensitive optically active compound whose helical twisting power changes upon irradiation with light
Data Source
AI summary
Provided is a liquid crystal composition capable of forming an optically anisotropic layer, and method thereof, in which a variation in a twisted angle of liquid crystal compound in an in-plane direction is suppressed an optical film, and a circularly polarizing plate for an organic EL display. The liquid crystal composition contains a liquid crystal, optically active compound A which is a photosensitive optically active compound whose helical twisting power changes upon irradiation with light and has a molar absorption coefficient of 5,000 M−1·cm−1 or more with respect to light having a wavelength of 365 nm, and an optically active compound B having a molar absorption coefficient with respect to light having a wavelength of 365 nm smaller than the molar absorption coefficient of the optically active compound A, in which a mass content ratio of the optically active compound A to the liquid crystal compound is less than 0.01.