Near Infrared Cut Filter Pigment Elution Prevention

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Solution Overview

Problem

Existing curable compositions for near infrared cut filters used in solid-state imaging elements, such as plasma display panels or CCDs, face issues with near infrared-absorbing pigments being eluted when the cured films are immersed in solvents, leading to reduced effectiveness.

Innovation Solution

A curable composition comprising a near infrared-absorbing pigment with a hydrophobic group and a curable polymer containing fluorine or silicon atoms, along with curable functional groups like (meth)acryloyloxy, epoxy, or oxetanyl groups, which forms a high concentration surface layer during curing, preventing pigment elution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a curable composition including a near infrared-absorbing pigment is used to form a cured film, then the near infrared cut filter can be manufactured, but the near infrared-absorbing pigment is eluted when the cured film is immersed in a solvent

Engineering Contradiction:
Improvepigment retentionVSAvoidpigment elution
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The invention changes the chemical composition parameters of the curable polymer by incorporating fluorine atoms and silicon atoms, along with specific curable functional groups. This compositional modification creates a cured film with enhanced chemical resistance that prevents pigment elution while maintaining the near infrared absorption function

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite curable polymer system combining fluorine-containing components and silicon-containing components with specific functional groups ((meth)acryloyloxy, epoxy, or oxetanyl groups). This composite material structure provides both the durability to resist solvent-induced pigment elution and the optical properties needed for near infrared cut filtration

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If a conventional curable composition is used, then the manufacturing process is simple, but the cured film allows pigment elution in solvents reducing filter effectiveness

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidfilter effectiveness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention modifies the chemical parameters of the curable polymer by specifying the inclusion of fluorine atoms, silicon atoms, and particular curable functional groups. These parameter changes enhance the cured film's resistance to pigment elution while maintaining compatibility with existing curable composition manufacturing processes

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 composition effectively prevents the elution of near infrared-absorbing pigments from the cured film even when immersed in solvents, enhancing the durability and performance of near infrared cut filters.

Implementation Method 1

a near infrared-absorbing pigment (A) comprising a hydrophobic group; and a curable polymer (B) comprising at least one of a fluorine atom and a silicon atom

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 2

a curable polymer (B) comprising at least one of a fluorine atom and a silicon atom, and comprising one or more curable functional groups selected from a (meth)acryloyloxy group, an epoxy group, and an oxetanyl group

Methodology Applied
Scientific EffectPhotopolymerisation: Photopolymerisation

Data Source

PatentEP3009479B1Curable composition, cured film, near infrared cut filter, camera module and method for manufacturing camera module
Publication Date: 2021.12.15 FUJIFILM CORP
  • EP3009479B1 patent drawingFigure 1
  • EP3009479B1 patent drawingFigure 2
  • EP3009479B1 patent drawingFigure 3~5

AI summary

Provided are a curable composition which can be used to produce a cured film that does not easily allow a near infrared-absorbing pigment to be eluted even when the cured film is immersed in a solvent, a cured film, a near infrared cut filter, a camera module, and a method for manufacturing a camera module. The curable composition including: a near infrared-absorbing pigment (A) and a curable compound (B) having one or more atoms or groups selected from a fluorine atom, a silicon atom, a linear alkyl group having 8 or more carbon atoms, and a branched alkyl group having 3 or more carbon atoms.