Photo-Alignment Layer Composition for Liquid Crystal Cells
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Solution Overview
Problem
Cyclic olefin-based photo-alignment polymers used in liquid crystal cells often suffer from afterimage generation and decreased voltage holding ratio due to non-hardened photoreactive groups, which affect thermal stability and alignment rates.
Innovation Solution
Incorporating a polyamic acid ester-based photo-alignment additive with the cyclic olefin-based photo-alignment polymer to enhance thermal stability, alignability, and voltage holding ratio by promoting fine phase separation and improved interactions with the liquid crystal layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If cyclic olefin-based photo-alignment polymer is used, then thermal stability and photo-alignability are improved, but afterimage generation occurs and voltage holding ratio decreases
Solution Approach 1:
The patent combines cyclic olefin-based photo-alignment polymer with polyamic acid ester-based photo-alignment additive to create a composite photo-alignment layer. This composite structure allows the cyclic olefin polymer to provide thermal stability while the polyamic acid ester additive suppresses afterimage generation and improves voltage holding ratio, thus resolving the contradiction between thermal stability and reliability
2Ease of operation
If cyclic olefin-based photo-alignment polymer is used, then photo-alignability is improved, but afterimage generation occurs
Solution Approach 1:
The patent converts the harmful effect of non-hardened photoreactive groups (which cause afterimage) into a beneficial effect by adding polyamic acid ester-based photo-alignment additive. This additive undergoes photoreaction to form a hardened structure that suppresses afterimage generation while maintaining the photo-alignability provided by the cyclic olefin polymer
3Productivity
If cyclic olefin-based photo-alignment polymer is used, then alignment rate is improved, but voltage holding ratio decreases
Solution Approach 1:
The patent creates a composite photo-alignment layer combining cyclic olefin-based polymer (providing high alignment rate) with polyamic acid ester-based additive (providing improved voltage holding ratio). The synergistic effect of this composite material allows both high productivity in alignment and high reliability in voltage holding
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 combination significantly reduces afterimage formation and improves voltage holding ratio while maintaining superior alignability and alignment rates, effectively addressing the limitations of cyclic olefin-based polymers alone.
Implementation Method 1
irradiated with linearly polarized UV light so that a photoreaction takes place
Implementation Method 2
non-hardening of the photoreactive group or the backbone of the photo-alignment polymer which has not yet undergone photoreaction and photo-alignment
Data Source
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AI summary
This invention relates to a composition for a photo-alignment layer which can exhibit superior thermal stability, alignability, and alignment rate, and can also suppress generation of an afterimage and further improve a voltage holding ratio when applied to a liquid crystal cell, and to a photo-alignment layer and a liquid crystal alignment layer using the same. The composition for a photo-alignment layer includes a cyclic olefin-based photo-alignment polymer and a polyamic acid ester-based photo-alignment additive.