Cellulose-Film Modifier for LCD Optical Anisotropy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cellulose acylate films used in liquid crystal display devices face issues with increased moisture permeability under high-temperature and high-humidity conditions, leading to deterioration in properties, and the addition of plasticizers results in increased optical anisotropy, thermal volatility, and incompatibility with the film, causing whitening and process contamination.
Innovation Solution
A cellulose-film modifier represented by specific succinic ester compounds is used to reduce optical anisotropy and enhance compatibility with cellulose acylate films, preventing volatilization and precipitation during casting and drying, and minimizing elution into saponification solutions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasticizer content is increased to reduce moisture permeability, then moisture resistance is improved, but optical anisotropy increases and film whitening occurs
Solution Approach 1:
The invention changes the chemical structure parameters of the plasticizer by specifying compounds with particular molecular weight ranges (500-2000) and functional groups (carboxyl, hydroxyl, or amine groups with specific substitution patterns). This parameter optimization allows achieving moisture resistance while controlling optical anisotropy and preventing film whitening.
Solution Approach 2:
The invention creates a composite system by combining cellulose acylate with specifically designed plasticizer molecules that have complementary properties. The composite achieves both moisture resistance and optical clarity by selecting plasticizers with appropriate molecular weights and functional groups that are compatible with the cellulose matrix.
2Strength
If plasticizer addition amount is increased to improve film properties, then film flexibility is improved, but compatibility deteriorates causing whitening
Solution Approach 1:
The invention optimizes the molecular weight parameter of the plasticizer within a specific range (500-2000) to achieve optimal compatibility. Plasticizers with molecular weights in this range provide sufficient flexibility while maintaining homogeneous distribution in the cellulose acylate matrix, preventing phase separation and whitening.
Solution Approach 2:
The invention introduces functional groups (carboxyl, hydroxyl, or amine groups with specific substitution patterns) that create localized interaction sites between the plasticizer and cellulose acylate chains. These localized interactions enhance compatibility and uniform distribution throughout the film matrix.
3Stability of the object's composition
If low-molecular weight plasticizer is used to improve compatibility, then film homogeneity is improved, but thermal volatility increases causing process contamination
Solution Approach 1:
The invention optimizes the molecular weight parameter to a balanced range (500-2000) rather than using low-molecular weight compounds. This parameter selection achieves sufficient film homogeneity while the increased molecular weight reduces thermal volatility, preventing vaporization during drying and casting processes.
Solution Approach 2:
The invention creates a composite system where the plasticizer's functional groups (carboxyl, hydroxyl, or amine groups) form strong intermolecular interactions with cellulose acylate chains. These interactions reduce the plasticizer's tendency to volatilize while maintaining homogeneous distribution in the film matrix.
4Manufacturing precision
If polyvalent alcohol plasticizer is added to reduce optical anisotropy, then optical isotropy is improved, but compatibility deteriorates causing whitening
Solution Approach 1:
The invention optimizes the molecular weight parameter of polyvalent alcohol-based plasticizers within the range of 500-2000 and specifies functional group substitution patterns. This parameter optimization allows achieving reduced optical anisotropy while maintaining compatibility and preventing film whitening.
Solution Approach 2:
The invention introduces specific functional group substitutions (carboxyl, hydroxyl, or amine groups at particular positions) that create localized interaction sites. These localized interactions enhance compatibility with cellulose acylate while the overall molecular structure reduces optical anisotropy.
Data Source
AI summary
A cellulose-film modifier, having a compound represented by the following Formula (1):wherein R1 represents a hydrogen atom or an aliphatic or aromatic acyl group; R2, R3 and R4 each represent a hydrogen atom or an aliphatic or aromatic group; and at least one of R2, R3 and R4 represents an aliphatic group bonding via its secondary carbon; a cellulose composition, an optical cellulose film, a polarizing plate-protecting film, a polarizing plate, and a liquid crystal display device.