Infrared-Transmitting Rubber Composition With Visible Light Absorption

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Solution Overview

Problem

Existing technologies face challenges with materials that are hard and have poor flexibility and poor selectivity, and the existing technologies are not effectively addressing the issues of existing technologies are not effectively addressing the issues of flexibility and selectivity in the use of rubber compositions for sensors and the like, particularly in the absorption and transmission of specific wavelengths of light.

Innovation Solution

A rubber composition comprising a polymer, a crosslinking agent, and a colorant without inorganic black pigment, achieving a minimum transmittance of 50% in the wavelength range of 800 to 1600 nm and a maximum transmittance of 40% in the range of 350 to 700 nm, with the use of organic colorants for selective infrared transmission and visible light absorption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If resin compositions are used for wavelength-selective absorption, then light absorption selectivity is improved, but flexibility and crack resistance deteriorate

Engineering Contradiction:
Improvewavelength selection accuracyVSAvoidflexibility and crack resistance
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

The patent uses a composite material system consisting of rubber base (providing flexibility), transparent resin (providing structural integrity), and wavelength-selective absorption particles (providing optical function). This composite structure combines the advantages of different materials to achieve both flexibility and wavelength-selective absorption without cracking.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies wavelength-selective absorption particles locally within the rubber composition rather than making the entire material rigid. The particles are dispersed throughout the flexible rubber matrix, providing optical functionality only where needed while maintaining overall flexibility and crack resistance of the rubber base.

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If carbon black or inorganic pigments are added to rubber for visible light absorption, then visible light shielding is improved, but infrared light transmission deteriorates

Engineering Contradiction:
Improvevisible light shieldingVSAvoidinfrared light transmission
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The patent uses organic pigments with specific absorption characteristics that selectively absorb visible light while transmitting infrared light. The pigments are chosen based on their spectral absorption properties to achieve the desired optical filtering effect without blocking the infrared wavelength range needed for sensor operation.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent changes the chemical composition parameters by using organic pigments instead of traditional carbon black or inorganic pigments. This parameter change in the pigment type fundamentally alters the optical transmission characteristics, enabling selective visible light absorption while maintaining infrared transparency.

Inventive Principle:
Principle #35Parameter changes

3Illumination intensity

If transparent rubber is used for infrared transmission, then infrared light transmission is improved, but visible light absorption capability deteriorates

Engineering Contradiction:
Improveinfrared light transmissionVSAvoidvisible light absorption
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent creates a composite where transparent rubber provides the infrared transmission pathway while dispersed organic pigment particles provide visible light absorption. The transparent rubber matrix allows infrared wavelengths to pass through, while the embedded pigment particles selectively absorb visible light, achieving both functions simultaneously.

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 rubber composition provides improved flexibility, impact resistance, and design freedom while effectively absorbing visible light and selectively transmitting infrared light, reducing the risk of cracking and enhancing the versatility of applications in sensors and imaging devices.

Implementation Method 1

a maximum transmittance in a wavelength of 350 to 700 nm is 40% or less

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 2

a minimum transmittance in a wavelength of 800 to 1600 nm is 50% or more

Methodology Applied
Scientific EffectLight transmission: Absorption (EM radiation)

Data Source

PatentUS20250340717A1Rubber composition
Publication Date: 2025.11.06 NOK CORP

AI summary

A rubber composition that includes (A) a polymer, (B) a crosslinking agent, and (C) a colorant, wherein the colorant (C) does not contain an inorganic black pigment, and a minimum transmittance in a wavelength of 800 to 1600 nm is 50% or more and a maximum transmittance in a wavelength of 350 to 700 nm is 40% or less in a rubber sheet having a thickness of 2 mm.