Thermochromic Paint for High-Temperature Indication

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Solution Overview

Problem

Existing thermochromic paints for temperature indication are limited by reversible color change, unsuitability for high-temperature applications like gas turbine engines, and difficulty in distinguishing temperature changes from carbon residues, especially at temperatures above 400°C.

Innovation Solution

A thermochromic paint formulation comprising a binder, inorganic oxide filler, and organic compounds with chromophores that provide irreversible color change at defined temperatures, excluding toxic metals, and featuring a distinctive white filler to differentiate from decomposition products, allowing for multiple temperature indications without requiring temperature-resistant monitoring equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing thermochromic paint is used for temperature indication, then color change occurs at defined temperature, but only one temperature change is indicated and the black color is indistinguishable from carbon residues

Engineering Contradiction:
Improvetemperature indication precisionVSAvoidinformation loss due to indistinguishable color
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent applies color change principle by using organic compound pigments that change color at specific temperatures. Multiple pigments with different decomposition temperatures are combined to create distinct color indications for different temperature levels, and the white filler ensures the decomposed state remains visually distinguishable from carbon residues

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent uses composite materials by combining binder, inorganic oxide filler, and organic compound pigments in specific proportions. The white inorganic oxide filler serves as a base that contrasts with decomposed organic compounds, preventing confusion with carbon residues while maintaining temperature indication capability

Inventive Principle:
Principle #40Composite materials

2Temperature

If existing thermochromic paint is used for high-temperature applications, then operation at elevated temperatures is possible, but the paint is unsuitable for gas turbine engines where temperatures reach 700°C

Engineering Contradiction:
Improveoperating temperature rangeVSAvoidadaptability to gas turbine engine applications
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by selecting organic compound pigments with specific decomposition temperatures suitable for high-temperature applications. The formulation includes pigments that remain stable and provide distinguishable color changes at temperatures up to 700°C and above, making the paint adaptable to gas turbine engine environments

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials with heat-resistant binder and inorganic oxide filler to maintain structural integrity and color indication capability at high temperatures. The combination of materials ensures the paint survives and functions in gas turbine engine conditions where temperatures reach 700°C

Inventive Principle:
Principle #40Composite materials

3Measurement precision

If existing thermochromic paint is used, then temperature indication is provided, but toxic heavy metals are included which fail to meet environmental requirements

Engineering Contradiction:
Improvetemperature indication capabilityVSAvoidenvironmental harm from toxic metals
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies the extraction principle by removing toxic heavy metals from the paint formulation. The temperature indication functionality is maintained using non-toxic organic compound pigments and inorganic oxide fillers, eliminating environmental harm while preserving measurement capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical composition parameters by substituting toxic heavy metal pigments with non-toxic organic compounds and inorganic oxides. This parameter change maintains the temperature indication capability through color changes at defined temperatures while meeting environmental requirements

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 paint effectively indicates multiple temperature changes with high stability up to 1200°C, enabling precise temperature assessment without confusion with carbon residues, and meets environmental requirements, suitable for high-temperature applications like gas turbine engines.

Implementation Method 1

an organic compound (0.1wt % to 28wt %) including a chromophore... each coloured pigment comprising a chromophore selected to decompose at a different temperature

Methodology Applied
Scientific EffectThermal decomposition: Decomposition (biological)

Implementation Method 2

The filler may comprise a distinctive colour. The distinctive colour may be white... Advantageously the filler is not black so that it is distinctive is comparison to decomposition products such as soot

Methodology Applied
Scientific EffectColor stability:

Implementation Method 3

1wt % to 90wt % binder... The binder may comprise an acrylic resin... Alternatively the binder may comprise a silicon resin

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3497170B1Thermochromic paint
Publication Date: 2021.05.05 ROLLS ROYCE PLC
  • EP3497170B1 patent drawingFigure 1~2
  • EP3497170B1 patent drawingFigure 3~4
  • EP3497170B1 patent drawingFigure 5

AI summary

A thermochromic paint 42 comprising: 1wt % to 90wt % binder; 2wt % to 40wt % filler comprising an inorganic oxide; and 0.1 wt % to 28wt % organic compound including a chromophore. The paint provides an irreversible indication of maximum temperature.