Infrared Shielding Laminate with Core-Shell ITO Particles

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Solution Overview

Problem

Existing infrared light shielding laminates face issues such as low transmittance, radio wave shielding leading to communication interference, and poor thermal insulation, as well as peeling of ITO particle films due to inadequate protection and spatial arrangement of nanoparticles.

Innovation Solution

An infrared light shielding laminate with a core shell ITO particle-containing layer, where ITO particles are coated with an insulating material, and an overcoat layer is applied to prevent conductive contact and enhance adhesion, using materials like silica, alumina, or organic protective agents, and a base coat layer for additional protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a continuous thin Ag film is used for infrared light shielding, then excellent transparency to visible light and reflectance of near infrared light are achieved, but radio waves are shielded causing communication failure

Engineering Contradiction:
Improvevisible light transparencyVSAvoidradio wave shielding
Core Design Contradiction:
Illumination intensityVSObject-generated harmful factors

Solution Approach 1:

The continuous Ag film is replaced with discrete Ag nanoparticles dispersed in a transparent resin layer. This segmentation allows the film to reflect near-infrared light through plasmon resonance while maintaining radio wave transparency, as the gaps between particles prevent continuous conduction paths for radio frequencies.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent optimizes the particle diameter of Ag nanoparticles to 1-100 nm to achieve selective optical properties. At this scale, the particles exhibit plasmon resonance in the near-infrared region while remaining transparent to visible light and radio waves, effectively changing the electromagnetic interaction parameters.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If ITO particles are used without proper protection, then infrared light shielding is achieved, but the film peels due to inadequate adhesion and protection

Engineering Contradiction:
Improveinfrared light shieldingVSAvoidfilm adhesion and protection
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent creates a composite structure with ITO particles embedded in a transparent resin matrix, combined with a base coat layer and overcoat layer. This composite approach provides both infrared shielding functionality and mechanical protection, preventing peeling while maintaining optical properties.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies a transparent resin overcoat layer that forms a protective shell around the ITO particle layer. This thin film provides mechanical protection and adhesion without significantly affecting the optical transparency or infrared shielding performance of the underlying particles.

Inventive Principle:
Principle #30Flexible shells and thin films

3Object-generated harmful factors

If nanoparticles are used for infrared shielding, then radio wave transparency is maintained, but thermal insulation characteristics are insufficient

Engineering Contradiction:
Improveradio wave transparencyVSAvoidthermal insulation
Core Design Contradiction:
Object-generated harmful factorsVSLoss of energy

Solution Approach 1:

The patent combines multiple functional layers: a base coat layer for adhesion, an ITO particle-containing layer for infrared shielding and radio wave transparency, and an overcoat layer for protection. This merging of layers achieves both radio wave transparency and improved thermal insulation through the collective properties of the composite structure.

Inventive Principle:
Principle #5Merging (Combining)

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 laminate achieves high reflectance of near infrared light, prevents peeling, maintains radio wave transparency, and improves thermal insulation, making it suitable for applications like window glasses and automotive components.

Implementation Method 1

The electric field of surface plasmons excited by the light is strengthened due to near field effects occurring within the distance between particles

Methodology Applied
Scientific EffectNear field effect:

Implementation Method 2

The electric field of surface plasmons excited by the light is strengthened due to near field effects occurring within the distance between particles. The plasmon resonance light is radiated so that reflection occurs.

Methodology Applied
Scientific EffectSurface plasmon resonance:

Implementation Method 3

the overcoat layer infiltrates into the gap between the core shell particles in the surface portion of the upper surface of the ITO particle-containing layer

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3239746B1Infrared light shielding laminate and infrared light shielding material using same
Publication Date: 2021.01.20 MITSUBISHI MATERIALS CORP
  • EP3239746B1 patent drawingFigure 1(a)~2

AI summary

This infrared light shielding laminate includes: an ITO particle-containing layer; and an overcoat layer which covers an upper surface of the ITO particle-containing layer, wherein core shell particles are present in a state of being in contact with each other in the ITO particle-containing layer, and the core shell particle includes an ITO particle serving as a core and an insulating material serving as a shell that covers the core.