Dipyrromethene Metal Complex Colorant Multimer for High-Definition Color Filters
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional pigment dispersing methods for color filters, particularly in liquid crystal displays and solid-state image sensors, face challenges such as color unevenness, light scattering, and poor heat resistance due to coarse pigment particles, which hinder the achievement of high-definition and high-image-quality color filters with excellent light fastness and solvent resistance.
Innovation Solution
A colored curable composition incorporating a dipyrromethene metal complex as a colorant multimer with a polymerizable group and an alkali-soluble group is used, forming a cured film with improved light fastness, heat resistance, and solvent resistance, reducing color transfer and enhancing pattern formability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional dyes are used in colored curable compositions, then color purity can be achieved, but light fastness, heat resistance, and solvent resistance deteriorate
Solution Approach 1:
The patent uses dipyrromethene metal complex compounds as a composite material that combines the color purity of dyes with the stability of metal complexes. The metal center (Zn, Co, Cu, or V) coordinated with dipyrromethene ligands creates a stable composite structure that maintains excellent color properties while significantly improving light fastness, heat resistance, and solvent resistance compared to conventional organic dyes.
Solution Approach 2:
The patent changes the chemical parameters of the coloring agent by introducing polymerizable groups and alkali-soluble groups into the dipyrromethene metal complex structure. This allows the colorant to be incorporated into polymer networks for enhanced stability while maintaining solubility and processability, thus improving reliability without sacrificing color purity.
2Illumination intensity
If dyes are used in colored curable compositions, then color purity can be achieved, but radical polymerization is inhibited
Solution Approach 1:
The patent extracts the problematic property (radical polymerization inhibition) from conventional dyes by selecting dipyrromethene metal complexes that do not exhibit this inhibitory effect. The metal complex structure fundamentally changes the chemical behavior, allowing the coloring function to be retained while the harmful polymerization inhibition property is eliminated.
Solution Approach 2:
The patent copies the desirable color properties of conventional dyes into dipyrromethene metal complexes, which have similar optical characteristics but different chemical reactivity. The metal complex structure replicates the color purity function while avoiding the polymerization inhibition issue.
3Illumination intensity
If dyes are used in colored curable compositions, then color purity can be achieved, but solubility in alkaline solutions deteriorates
Solution Approach 1:
The patent changes the solubility parameters by introducing alkali-soluble groups into the dipyrromethene metal complex structure. This modification allows the colorant to be soluble in alkaline solutions, enabling easy removal of unreacted material during development while maintaining excellent color purity. The parameter change transforms an insoluble or poorly soluble dye into an alkali-soluble colorant.
4Reliability
If pigment dispersing methods are used, then heat resistance and light fastness are improved, but particle size must be reduced for higher image quality
Solution Approach 1:
The patent changes the fundamental parameter of the coloring agent from particulate pigment to molecular-level metal complex. This parameter change eliminates the need for particle size control while maintaining excellent heat resistance and light fastness. The molecular structure provides inherent stability without requiring dispersion of fine particles.
Solution Approach 2:
The patent replaces the mechanical dispersion approach (grinding and dispersing pigment particles) with a chemical approach (molecular-level metal complex formation). This substitution eliminates the need for mechanical particle size reduction while achieving the same or better performance in heat resistance and light fastness.
5Illumination intensity
If finer pigment particles are used to improve contrast, then color purity improves, but light scattering increases due to aggregation
Solution Approach 1:
The patent replaces the particulate pigment system with a molecular metal complex system, eliminating the mechanical aggregation issue. The molecular-level colorants do not aggregate into light-scattering clusters, thus achieving high color purity without the harmful light scattering effect that plagues fine pigment dispersions.
Solution Approach 2:
The patent changes the scale parameter from particulate (micrometer/nanometer scale) to molecular (angstrom scale). This parameter change fundamentally eliminates light scattering because molecular dimensions are far below the wavelength of visible light, making scattering negligible while maintaining intense color absorption.
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 solution enables the production of color filters with excellent color purity, light fastness, and heat resistance, even in thin films, while minimizing color unevenness and pattern defects, suitable for high-definition applications in liquid crystal displays and solid-state image sensors.
Implementation Method 1
Coloring agents used in the color filter are commonly required to have the following characteristics. That is, they are required to have preferable light absorption characteristics in view of color reproducibility
Implementation Method 2
A colorant multimer incorporating a dipyrromethene metal complex with a polymerizable group and an alkali-soluble group is introduced, forming a cured film with enhanced solvent resistance, reduced color transfer, and improved pattern formability
Data Source
AI summary
A colorant multimer includes, as a partial structure of a colorant moiety, a dipyrromethene metal complex compound or tautomer thereof obtained from:(i) a dipyrromethene compound represented by the following Formula (M); and(ii) a metal or a metal compound:wherein in Formula (M), R4, R5, R6, R7, R8, R9, and R10 each independently represent a hydrogen atom or a monovalent substituent.