Curable Composition Resin for Color Filter Moisture Resistance

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Solution Overview

Problem

Curable compositions used in color filters and solid-state imaging elements face challenges with storage stability and moisture resistance, leading to film shrinkage and deteriorated light-collecting properties when exposed to high humidity environments.

Innovation Solution

A curable composition incorporating a resin with a poly(meth)acrylate structure and an acid group, which includes a graft chain with specific repeating units, improves pigment dispersibility and storage stability while enhancing moisture resistance by forming a film with improved developability and color reproducibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a curable composition includes a pigment dispersed with a conventional graft polymer resin, then storage stability is improved, but moisture resistance deteriorates leading to film shrinkage in high humidity environments

Engineering Contradiction:

Improvestorage stabilityVSAvoidmoisture resistance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent modifies the chemical structure parameters of the dispersant by specifying a graft polymer with particular characteristics: poly(meth)acrylate structure in the graft chain, glass transition temperature of -50°C to 0°C, and specific Hansen solubility parameters. These parameter changes enable the dispersant to provide both storage stability and moisture resistance, preventing film shrinkage in high humidity while maintaining pigment dispersibility.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite dispersant system combining a base polymer with grafted poly(meth)acrylate chains. This composite structure integrates the dispersing capability of the base polymer with the moisture resistance properties of the poly(meth)acrylate graft chains, achieving both storage stability and resistance to humidity-induced film shrinkage simultaneously.

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If the film is exposed to high humidity environment for long period, then storage stability is compromised, but film shrinkage occurs leading to deteriorated light-collecting property

Engineering Contradiction:

Improvestorage stabilityVSAvoidlight-collecting property

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent applies beforehand cushioning by incorporating a dispersant with predetermined moisture-resistant properties (specific graft polymer with controlled glass transition temperature and solubility parameters) into the curable composition before film formation. This preemptive measure cushions against the harmful effects of high humidity exposure, preventing film shrinkage and maintaining pixel height uniformity and light-collecting properties during long-term storage.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If conventional dispersants are used to disperse pigment, then storage stability is improved, but developability deteriorates

Engineering Contradiction:

Improvestorage stabilityVSAvoiddevelopability

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent optimizes the dispersant structure by controlling the glass transition temperature (-50°C to 0°C) and Hansen solubility parameters of the graft polymer. This parameter optimization enables the dispersant to maintain pigment dispersibility and storage stability while being compatible with the photopolymerization process, ensuring good developability without compromising storage stability.

Inventive Principle:

Principle #35Parameter changes

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 curable composition achieves excellent storage stability and moisture resistance, preventing film shrinkage and maintaining light-collecting properties even in high humidity conditions, thereby ensuring consistent performance in color filters and solid-state imaging elements.

Implementation Method 1

a curable composition including a pigment, a resin, a polymerizable compound, a photopolymerization initiator, and a solvent

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentUS11965047B2Curable composition, film, structural body, color filter, solid-state imaging element, and image display device

Publication Date: 2024.04.23 FUJIFILM CORP

AI summary

Provided are a curable composition including a pigment, a resin, a polymerizable compound, a photopolymerization initiator, and a solvent; a film formed of the curable composition; a structural body; a color filter; a solid-state imaging element; and an image display device. The resin includes a resin A which includes a repeating unit having a graft chain of a poly(meth)acrylate structure and a repeating unit having an acid group, and the graft chain of a poly(meth)acrylate structure includes a repeating unit represented by the following formula. R1 represents a hydrogen atom or a methyl group, and R2 represents a hydrocarbon group having 1 to 20 carbon atoms. However, R1 is a hydrogen atom in a case where R2 is a methyl group, and R2 is a hydrocarbon group having 2 or more carbon atoms in a case where R1 is a methyl group.