Colored Photocurable Composition for Image Sensors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current colored photocurable compositions for solid state image pick-up devices face challenges such as pigment aggregation, low light transmittance, color unevenness, and insufficient curing sensitivity due to coarse pigment particles and limited photopolymerization initiator and monomer concentrations, leading to image quality issues and difficulties in forming fine pixel patterns.
Innovation Solution
A colored photocurable composition containing a dispersion resin with an unsaturation equivalent of less than 600, a pigment, a photopolymerization initiator, and a polyfunctional photopolymerizable compound with acidic functional groups or alkyleneoxy chains, which improves pigment dispersibility, storage stability, and curing sensitivity, enabling the formation of high-quality color filters with enhanced light transmittance and color purity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pigment particles are finely pulverized to improve dispersibility and light transmittance, then color purity and light transmittance are improved, but particle aggregation is promoted due to increased surface area
Solution Approach 1:
The patent introduces a specific dispersant as an intermediary substance between pigment particles to prevent aggregation. The dispersant has a molecular structure comprising a polyol portion and a carboxylic acid portion, which adsorbs onto pigment surfaces and provides steric and electrostatic repulsion, allowing fine pigment particles to remain dispersed without aggregating.
Solution Approach 2:
The patent optimizes the molecular weight ratio between the dispersant and pigment, specifying that the dispersant molecular weight should be 0.01 to 10 times the pigment molecular weight. This parameter control ensures effective surface coverage and stabilization of fine pigment particles while maintaining flowability and preventing aggregation.
2Manufacturing precision
If pigment concentration is increased to improve color density, then color purity is improved, but viscosity increases and fluidity deteriorates
Solution Approach 1:
The dispersant acts as a mediator that reduces inter-particle forces and prevents aggregation even at high pigment concentrations. This allows the composition to maintain low viscosity and good fluidity while achieving high color density through increased pigment concentration.
Solution Approach 2:
The patent specifies optimal pigment concentration ranges (5-50 wt%) combined with appropriate dispersant amounts (0.1-10 parts by weight per 100 parts pigment) to achieve high color density while maintaining processability and fluidity through controlled composition parameters.
3Productivity
If photopolymerization initiator and monomer concentrations are increased to improve curing sensitivity, then curing speed is improved, but color unevenness occurs due to light scattering and absorption by pigment particles
Solution Approach 1:
The patent applies preliminary dispersion treatment using the specific dispersant before photopolymerization, ensuring uniform pigment distribution and minimizing light scattering. This preliminary action prevents color unevenness during curing while allowing high initiator and monomer concentrations for fast curing sensitivity.
Solution Approach 2:
The dispersant serves as an intermediary that creates a uniform medium between light and pigment particles, reducing light scattering effects. This enables high photopolymerization initiator concentrations to achieve fast curing without the color unevenness that would normally result from light absorption by aggregated pigment particles.
4Stability of the object's composition
If pigment particles are coarse to maintain storage stability, then particle aggregation is reduced, but light transmittance decreases and contrast is deteriorated
Solution Approach 1:
The dispersant acts as a protective intermediary that stabilizes fine pigment particles in storage, preventing aggregation despite their high surface area. This allows the use of fine particles (0.1-10 μm) that provide high light transmittance and contrast while maintaining storage stability through the dispersant's steric and electrostatic stabilization mechanisms.
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 achieves improved pigment dispersibility, storage stability, and curing sensitivity, resulting in high-quality color filters with enhanced light transmittance and color purity, addressing issues of color unevenness and image quality by ensuring proper curing and pattern formation, even at fine pixel sizes.
Implementation Method 1
contains a photopolymerization initiator and a polyfunctional photopolymerizable compound
Data Source
AI summary
A colored photocurablc composition for a solid state image pick-up device, the composition including at least (A) a dispersion resin having an unsaturation equivalent of less than 600, (B) a pigment, (C) a photopolymerization initiator, and (D) a polyfunctional photopolymerizable compound having an acidic functional group and/or an alkyleneoxy chain.