Cleaning Composition for Liquid Crystal Alignment Film
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Solution Overview
Problem
The existing cleaning processes for liquid crystal alignment layers after UV alignment often result in non-uniformity and deterioration of the alignment layer characteristics, particularly when using water, ethanol, or IPA as cleaning agents.
Innovation Solution
A cleaning composition comprising tetrahydrofurfuryl alcohol or methyl 2-hydroxyisobutyrate, combined with specific alkylene glycol-based compounds and polar solvents, is used to effectively clean the polymer surface of UV-aligned liquid crystal alignment layers, enhancing anisotropy and removing ionic impurities while maintaining alignment stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional cleaning agents (water, ethanol, or IPA) are used to clean the UV-aligned liquid crystal alignment layer, then the cleaning process can remove impurities, but the liquid crystal alignment layer becomes non-uniform and its characteristics are impaired
Solution Approach 1:
The patent changes the chemical parameters of the cleaning agent by selecting specific organic solvents (acetone, butanone, cyclohexanone, or methyl ethyl ketone) with particular molecular structures and polarities. These parameter changes enable effective impurity removal while preserving the alignment layer's uniformity and characteristics, resolving the contradiction between cleaning effectiveness and alignment quality.
2Manufacturing precision
If the UV alignment process is used to replace the rubbing process, then alignment uniformity and contrast ratio are improved, but an additional cleaning process is required
Solution Approach 1:
The patent modifies the cleaning process parameters by using specifically selected organic solvents that can effectively remove UV decomposition products without damaging the alignment layer. This optimized cleaning approach, while still requiring an additional step, minimizes the negative impact of process complexity by ensuring the cleaning step is highly effective and necessary for maintaining alignment quality.
3Ease of manufacture
If the rubbing method is used to align liquid crystals, then the alignment process is simple, but fine dust and electrostatic discharge occur causing serious manufacturing problems
Solution Approach 1:
The patent replaces the mechanical rubbing method with a UV light-based alignment method. This substitution eliminates the mechanical contact that generates fine dust and electrostatic discharge, thereby removing the harmful factors while maintaining alignment functionality. The UV alignment process uses photonic energy instead of mechanical force to achieve liquid crystal orientation.
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 proposed cleaning composition increases anisotropy and uniformity of the liquid crystal alignment layer, effectively removing impurities and preventing deterioration, thereby improving the stability and reliability of the liquid crystal display device's electrical characteristics and contrast ratio.
Implementation Method 1
The UV alignment process is a light alignment method in which anisotropy is induced on a polymer layer by light irradiation
Implementation Method 2
an ionic byproduct including a UV decomposition product of the polyimide layer is washed and removed from the polymer surface of the polyimide layer by the cleaning composition
Data Source
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AI summary
The present invention relates to a cleaning composition for a liquid crystal alignment layer, a manufacturing method of a liquid crystal alignment layer using the same, and a liquid crystal display device including the liquid crystal alignment layer manufactured by the manufacturing method. More specifically, the present invention relates to a cleaning composition for a liquid crystal alignment layer that is capable of solving a non-uniformity problem of the liquid crystal alignment layer and effectively removing an ionic byproduct on a polymer surface to increase anisotropy of the liquid crystal alignment layer, by using a cleaning composition including a specific solvent in a cleaning process after a UV alignment process, and a manufacturing method of a liquid crystal alignment layer.