Surface-Treated Tungsten Oxide Particles for Moisture Resistance

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Solution Overview

Problem

Infrared shielding materials, particularly those containing tungsten oxide fine particles, face degradation due to penetration of steam and water, leading to reduced infrared absorption performance over time, necessitating improved moisture and heat resistance.

Innovation Solution

Surface-treated infrared absorbing fine particles coated with a hydrolysis product of metal chelate or metal cyclic oligomer compounds, such as aluminum or zinc-based compounds, to form a strong coating layer, enhancing moisture and heat resistance while maintaining infrared absorption properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If infrared shielding materials containing tungsten oxide fine particles are used, then infrared absorption performance is achieved, but moisture and heat resistance deteriorates due to penetration of steam and water

Engineering Contradiction:
Improveinfrared absorption performanceVSAvoidmoisture and heat resistance
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent creates a composite structure by coating tungsten oxide fine particles with a silane-based coating layer. The core tungsten oxide particles provide infrared absorption functionality, while the silane coating layer provides moisture and heat resistance, achieving a composite material that combines both properties effectively.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The silane-based coating layer acts as an intermediary protective barrier between the tungsten oxide fine particles and the external environment (steam and water). This coating layer mediates the interaction by preventing direct contact between water/steam and the tungsten oxide particles, thereby maintaining both infrared absorption performance and moisture/heat resistance.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Duration of action of stationary object

If surface coating is applied to improve moisture and heat resistance, then durability is enhanced, but manufacturing complexity increases

Engineering Contradiction:
ImprovedurabilityVSAvoidmanufacturing process complexity
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The silane-based coating is applied in advance to the tungsten oxide fine particles before they are incorporated into the final infrared shielding material. This preliminary surface treatment ensures that the particles are pre-protected against moisture and heat, enhancing durability without requiring complex post-processing steps.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the surface parameters of the tungsten oxide particles by introducing a silane-based coating layer with specific chemical properties (hydrolysis products, condensation products, or polymers). This parameter change at the surface level provides enhanced moisture and heat resistance while maintaining the bulk properties of the tungsten oxide particles.

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 surface-treated particles exhibit excellent moisture and heat resistance along with improved infrared absorption performance, making them suitable for outdoor applications with increased durability.

Implementation Method 1

a surface of infrared absorbing fine particles is coated with a coating layer containing at least one selected from a hydrolysis product of a metal chelate compound, a polymer of the hydrolysis product of the metal chelate compound, a hydrolysis product of a metal cyclic oligomer compound, and a polymer of the hydrolysis product of the metal cyclic oligomer compound

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

infrared absorbing fine particles that transmit light in a visible light region and absorb light in an infrared region

Methodology Applied
Scientific EffectInfrared absorption: Absorption (EM radiation)

Data Source

PatentEP3712223B1Surface-treated infrared-absorbing fine particles, surface-treated infrared-absorbing fine particle powder, infrared-absorbing fine particle dispersion in which said surface-treated infrared-absorbing fine particles are used, infrared-absorbing fine particle dispersoid, and methods for producing these
Publication Date: 2022.10.26 SUMITOMO METAL MINING CO LTD
  • EP3712223B1 patent drawingFigure 1~2

AI summary

An object is to provide surface-treated infrared-absorbing fine particles with excellent moisture and heat resistance and excellent infrared-absorbing properties, surface-treated infrared absorbing fine particle powder containing the surface-treated infrared absorbing fine particles, an infrared absorbing fine particle dispersion liquid and an infrared absorbing fine particle dispersion body using the surface-treated infrared absorbing fine particles, and a method for producing them, wherein a surface of infrared absorbing particles is coated with a coating layer containing at least one selected from hydrolysis product of a metal chelate compound, polymer of hydrolysis product of a metal chelate compound, hydrolysis product of a metal cyclic oligomer compound, and polymer of hydrolysis product of a metal cyclic oligomer compound.