Complex Oxide Infrared Absorbing Particles for Selective NIR Transparency

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Solution Overview

Problem

Existing infrared ray absorbing materials lack optical characteristics that allow for selective absorption of near-infrared rays, particularly in the wavelength range that causes a burning sensation on human skin, while maintaining transparency in the visible light region.

Innovation Solution

Development of infrared ray absorbing particles composed of a complex oxide containing specific ratios of A1, A2, and B elements, which generate free electrons or electron holes to absorb near-infrared rays effectively in the 1,400 nm to 2,100 nm range, while being transparent in the visible light region.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional infrared absorbing materials (carbon black, titanium black, aniline black) are used, then infrared ray absorption is achieved, but visible light transparency is compromised and selective absorption in specific wavelength ranges cannot be realized

Engineering Contradiction:
Improveinfrared ray absorptionVSAvoidvisible light transparency
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent changes the chemical composition parameters by using complex oxide materials with specific element ratios (A1:A2:B = 1:2:4) and controls particle size parameters (0.1-10 μm) to achieve selective infrared absorption while maintaining visible light transparency. This resolves the contradiction by precisely adjusting material parameters rather than using conventional broad-spectrum absorbers.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite oxide materials containing specific combinations of elements (A1: H or alkali metals, A2: Mg or alkaline earth metals, B: V, Nb, or Ta) to create a material that selectively absorbs infrared rays in the 1,400-2,100 nm range while remaining transparent in the visible region, thus resolving the contradiction between absorption and transparency.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If broad-spectrum infrared absorbing materials are used, then overall infrared absorption is achieved, but selective absorption in the 1,400 nm to 2,100 nm wavelength range (which causes burning sensation) cannot be targeted

Engineering Contradiction:
Improveburning sensation reductionVSAvoidselective wavelength absorption
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent applies local quality by designing the complex oxide material to have specific absorption characteristics in the 1,400-2,100 nm wavelength range, which corresponds to the burning sensation-causing infrared rays. The material's composition (A1:A2:B = 1:2:4) and particle size are optimized to target this specific spectral region, allowing selective absorption of harmful rays while permitting other wavelengths to pass through.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

By precisely controlling the compositional parameters (element ratios) and physical parameters (particle size distribution) of the complex oxide, the patent achieves selective absorption in the specific wavelength range that causes burning sensation, rather than broad-spectrum absorption. This enables targeted protection against harmful infrared radiation.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If complex oxide particles with specific composition ratios are synthesized, then selective infrared absorption is achieved, but manufacturing complexity increases

Engineering Contradiction:
Improveselective near-infrared absorptionVSAvoidmanufacturing process complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent specifies precise compositional parameters (A1:A2:B = 1:2:4) and particle size parameters (0.1-10 μm) for the complex oxide to achieve selective infrared absorption. By defining these parameters clearly, the patent enables controlled synthesis through conventional ceramic or sol-gel processes, balancing performance requirements with manufacturing feasibility.

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 complex oxide particles provide high absorption of near-infrared rays in the specified wavelength range, reducing heat sensation on skin, while maintaining clear visibility, and are produced through methods like solid-phase reaction or aerosol spraying.

Implementation Method 1

the infrared ray absorbing particles include a complex oxide... When x1 is an amount of substance of the A1 element included in the complex oxide, x2 is an amount of substance of the A2 element included in the complex oxide, and y is an amount of substance of the B element included in the complex oxide, x1, x2, and y satisfy relationships of 0.002 ≤ (x1+x2)/y ≤ 1.5, 0.001≤ x1/y ≤ 1, and 0.001 ≤ x2/y ≤ 1

Methodology Applied
Scientific EffectFree electron absorption: Absorption (EM radiation)

Data Source

PatentEP4692271A1Infrared absorbing particles, infrared absorbing particle dispersion solution, infrared absorbing particle dispersion body, and infrared absorbing laminate
Publication Date: 2026.02.11 SUMITOMO METAL MINING CO LTD
  • EP4692271A1 patent drawingFigure 1~2
  • EP4692271A1 patent drawingFigure 3~5
  • EP4692271A1 patent drawingFigure 6~7

AI summary

Infrared ray absorbing particles include a complex oxide. The complex oxide includes: an A1 element that is at least one element selected from the group consisting of H and alkali metals; an A2 element that is at least one element selected from the group consisting of Mg and alkaline earth metals; and a B element that is at least one element selected from the group consisting of V, Nb, and Ta. When x1 is an amount of substance of the A1 element included in the complex oxide, x2 is an amount of substance of the A2 element included in the complex oxide, and y is an amount of substance of the B element included in the complex oxide, x1, x2, and y satisfy relationships of 0.002 ≤ (x1+x2)/y ≤ 1.5, 0.001≤ x1/y ≤ 1, and 0.001 ≤ x2/y ≤ 1.