Acrylic-Modified Tungsten Oxide Powder for Transparent Heat Shielding

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Solution Overview

Problem

Existing heat ray shielding technologies face challenges such as high cost, poor adhesiveness, complex production processes, and limited weather resistance, particularly when using hexaboride fine particles dispersed in organic solvents, which lead to agglomeration and increased transportation costs.

Innovation Solution

A dispersion powder containing composite tungsten oxide fine particles with a hexagonal crystal structure, surface-modified with an acrylic dispersant, is used to create a heat ray shielding resin molded product and laminate, allowing for high concentrations of heat ray shielding particles with adjustable dilution, ensuring excellent weather resistance and transparency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hexaboride fine particles are dispersed in an organic solvent to form a coating liquid, then heat ray shielding function is achieved, but the coating liquid is classified as a dangerous material requiring special transportation restrictions and incurs high transportation costs

Engineering Contradiction:

Improveheat ray shielding functionVSAvoidtransportation cost and restrictions

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the physical state of the heat ray shielding composition from liquid (coating liquid requiring organic solvent) to solid (powder form). This parameter change eliminates the classification as dangerous material, removing transportation restrictions and reducing costs while maintaining the heat ray shielding function through the dispersed fine particles in powder form

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent extracts the organic solvent component from the coating liquid system, isolating only the essential heat ray shielding fine particles and binders in powder form. This extraction removes the dangerous material classification while preserving the core functional components needed for heat ray shielding

Inventive Principle:

Principle #2Taking out (Extraction)

2Duration of action of moving object

If hexaboride fine particles are stored in an organic solvent for a long period, then the coating liquid remains available for use, but the fine particles are prone to agglomeration due to Brownian motion forming precipitates

Engineering Contradiction:

Improvestorage durationVSAvoiddispersion stability

Core Design Contradiction:

Duration of action of moving objectVSStability of the object's composition

Solution Approach 1:

The patent removes the organic solvent medium that causes Brownian motion and agglomeration, storing only the fine particles in solid powder form. This extraction eliminates the mechanism causing instability while maintaining long-term availability of the heat ray shielding components

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the storage state from liquid suspension (prone to agglomeration) to solid powder (stable). This parameter change in physical state eliminates Brownian motion and prevents precipitate formation, ensuring long-term stability while maintaining dispersibility when needed

Inventive Principle:

Principle #35Parameter changes

3Reliability

If organic near-infrared absorbing agents are kneaded into thermoplastic transparent resin, then heat ray shielding is achieved, but the weather resistance is poor when exposed to direct sunlight

Engineering Contradiction:

Improveheat ray shielding functionVSAvoidweather resistance

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameter from organic near-infrared absorbing agents to inorganic heat ray shielding fine particles (such as metal oxides). This parameter change in material type provides superior weather resistance and stability under direct sunlight exposure while maintaining heat ray shielding functionality

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses composite inorganic heat ray shielding fine particles dispersed in thermoplastic transparent resin, combining the heat ray blocking properties of inorganic materials with the processability and transparency of thermoplastic resins. This composite approach achieves both durable weather resistance and effective heat ray shielding

Inventive Principle:

Principle #40Composite materials

4Reliability

If a large amount of near-infrared absorbing agent is incorporated to sufficiently shield heat rays, then heat ray shielding effectiveness is improved, but the visible light transmittance is reduced

Engineering Contradiction:

Improveheat ray shielding effectivenessVSAvoidvisible light transmittance

Core Design Contradiction:

ReliabilityVSIllumination intensity

Solution Approach 1:

The patent applies local quality by using fine particles with specific size ranges (0.1-10 μm) that are optimized to interact selectively with near-infrared radiation while being transparent to visible light. This localized optimization of particle properties achieves differential light interaction - blocking heat rays while maintaining visibility

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs composite inorganic heat ray shielding fine particles that possess unique optical properties allowing selective absorption of near-infrared radiation. These composite materials provide high heat ray shielding effectiveness at low concentrations, preserving visible light transmittance unlike organic absorbers that require large amounts

Inventive Principle:

Principle #40Composite materials

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 solution provides a heat ray shielding resin molded product and laminate with high weather resistance, effective heat ray blocking, and clear transparency, reducing cooling loads and energy consumption while avoiding complex processes and high costs.

Implementation Method 1

composite tungsten oxide fine particles with a hexagonal crystal structure... effective heat ray blocking... among the infrared rays contained in the sunlight, near-infrared rays with a wavelength of 800 to 2500 nm are called heat rays

Methodology Applied

Scientific EffectNear-infrared absorption: Absorption (EM radiation)

Implementation Method 2

surface-modified with an acrylic dispersant... composite tungsten oxide fine particles... dispersed in an organic solvent

Methodology Applied

Scientific EffectSurface modification: Adsorption

Implementation Method 3

when they enter through the opening, they cause the temperature inside a room to rise... heat ray shielding substrate that blocks heat rays... reducing cooling loads and energy consumption

Methodology Applied

Scientific EffectThermal radiation blocking: Absorption (EM radiation)

Data Source

PatentEP4703327A1Dispersed powder and method for producing same, heat ray-blocking resin molded body, and heat ray-blocking laminate

Publication Date: 2026.03.04 SUMITOMO METAL MINING CO LTD

AI summary

There is provided a dispersion powder containing composite tungsten oxide fine particles represented by a general formula MxWOy, having a hexagonal crystal structure, having a crystallite size of 15 nm or more and 80 nm or less, and surface-modified with an acrylic dispersant, wherein a weight ratio of the dispersant to the composite tungsten oxide fine particles is in a range of 0.3 ≤ (weight of dispersant / weight of composite tungsten oxide fine particles) < 3.0, and heat ray shielding resin molded product and heat ray shielding laminate produced using the dispersed powder.