Temperature Detection Label With Irreversible Anti-Falsification Color Change

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Solution Overview

Problem

Existing temperature-indicating agents can revert to their original color after a temperature change, allowing for falsification, and dual-ink systems require complex structures for independent temperature detection.

Innovation Solution

A temperature detection label with a simple structure using a temperature-indicating material that changes color irreversibly and includes a supporting member, protective layer, and a fraud detection member with a high melting point, utilizing a leuco dye, developer, and decolorant to maintain color change across temperature transitions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a reversible temperature-indicating agent is used, then the label can return to its original color after temperature change, but this allows for falsification of temperature detection

Engineering Contradiction:
Improvecolor reversibilityVSAvoidanti-falsification capability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent extracts the reversible color-changing component (temperature-indicating agent) from the label structure and replaces it with an irreversible temperature detection material. This removal of the reversible function eliminates the possibility of falsification while maintaining temperature detection capability through irreversible color change or physical state change.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the fundamental parameter of the temperature-indicating agent from reversible to irreversible color change. By selecting materials that undergo permanent chemical or physical changes at specific temperatures (such as leuco dyes that permanently decolorize or materials that change crystal structure), the label maintains operational simplicity while achieving anti-falsification reliability.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If two kinds of inks are used for independent temperature detection functions, then temperature detection accuracy is improved, but the label structure becomes complex

Engineering Contradiction:
Improvetemperature detection accuracyVSAvoidlabel structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the temperature detection material serve multiple functions simultaneously: it detects temperature changes, provides irreversible falsification prevention, and maintains visual indication. By selecting materials that exhibit both detection and anti-falsification properties in a single component, the patent eliminates the need for separate ink layers or microencapsulation systems, thereby reducing structural complexity while maintaining detection accuracy.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functions of temperature detection and falsification prevention into a single integrated material system. Instead of using separate inks for different detection functions, the patent combines these roles into one temperature detection material that inherently provides both measurement capability and anti-tampering properties through its irreversible response characteristics.

Inventive Principle:
Principle #5Merging (Combining)

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 label effectively prevents falsification by maintaining color changes and providing reliable temperature detection without returning to its original state, using a microencapsulated or phase-separated structure to isolate the temperature-indicating material.

Implementation Method 1

a temperature-indicating material that changes color irreversibly

Methodology Applied
Scientific EffectThermochromism: Thermochromism

Implementation Method 2

utilizing a leuco dye, developer, and decolorant to maintain color change across temperature transitions

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 3

using a microencapsulated or phase-separated structure to isolate the temperature-indicating material

Methodology Applied
Scientific EffectPhase separation:

Data Source

PatentEP3745105B1Temperature detection label and article management device using same
Publication Date: 2025.08.27 HITACHI LTD
  • EP3745105B1 patent drawingFigure 1
  • EP3745105B1 patent drawingFigure 2
  • EP3745105B1 patent drawingFigure 3(a)~3(b)

AI summary

The present invention addresses the problem of providing a temperature detection label capable of preventing falsification using a simple structure. To solve this problem, the present invention provides a temperature detection label that is characterized by comprising a supporting member and a temperature detection part provided on the supporting member and in that: the temperature detection part has a temperature detection material that, in a heating process, starts color development at temperature T1 and starts losing color as a result of melting at temperature T2 and, in a cooling process, solidifies while remaining colorless by being cooled to temperature T1 or lower; the temperature detection material includes a leuco dye, decolorizer, and developer; and the temperature detection label also comprises a member having an appearance that changes between T1 and T2, inclusive, or a high-melting-point material having a melting point or glass transition temperature higher than T2.