Thermal Recording Layer with Calcined Silicate Barrier Stability

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Solution Overview

Problem

Existing heat-sensitive recording materials lack sufficient resistance to environmental influences such as heat, humidity, chemicals, and light, leading to issues like image fading, smearing, and reduced durability, particularly in applications like tickets and receipts.

Innovation Solution

A heat-sensitive recording material comprising a substrate with a heat-sensitive recording layer containing specific dye precursors and color developers, and an intermediate layer of calcined aluminum silicate, which enhances resistance and image stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional heat-sensitive recording materials are used, then the basic color-forming function is achieved, but the resistance to environmental influences (heat, humidity, chemicals, light) is insufficient

Engineering Contradiction:
Improveresistance to environmental influencesVSAvoidimage stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

An intermediate layer comprising calcined aluminum silicate is introduced between the substrate and the heat-sensitive recording layer. This intermediary layer acts as a barrier that protects the recording layer from environmental influences such as humidity and chemicals, thereby improving resistance without altering the core color-forming components. The intermediate layer specifically prevents moisture penetration and chemical interaction while maintaining thermal conductivity for proper heat transfer during recording.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The recording material is structured as a composite system with distinct functional layers: a substrate, an intermediate layer of calcined aluminum silicate, and a heat-sensitive recording layer containing dye precursors and color developers. This composite structure allows each layer to optimize its specific function - the aluminum silicate layer provides environmental resistance while the recording layer maintains color-forming capability, achieving both durability and image stability simultaneously.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If the recording layer contains phenolic color developers and dye precursors, then color formation is achieved, but resistance to water, aqueous alcohol solutions, and plasticizers is reduced

Engineering Contradiction:
Improvecolor-forming capabilityVSAvoidresistance to water and chemicals
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The calcined aluminum silicate intermediate layer serves as a protective mediator between the hydrophobic recording layer and water-based environmental factors. This layer specifically blocks penetration of water, aqueous alcohol solutions, and plasticizers to the recording layer, preventing degradation of the phenolic color developers and dye precursors while allowing the color-forming chemistry to proceed normally during recording.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If environmental resistance is improved through material composition, then durability increases, but production cost and complexity may increase

Engineering Contradiction:
ImprovedurabilityVSAvoidlayer structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The calcined aluminum silicate is applied as a porous coating material that provides effective environmental protection with minimal material quantity. The porous structure offers high surface area and effective barrier properties against moisture and chemicals while maintaining thin layer thickness, thus adding protective function without significant increase in material cost or structural complexity.

Inventive Principle:
Principle #31Porous 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 material exhibits improved daylight resistance, higher optical density, reduced smearing, and increased print density, maintaining legibility under various environmental conditions.

Implementation Method 1

an intermediate layer comprising calcined aluminum silicate arranged between the substrate and the heat-sensitive recording layer

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

heat-sensitive recording layer containing at least one dye precursor and at least one color developer reactive with this dye precursor

Methodology Applied
Scientific EffectThermal reaction: Exothermic Reaction

Data Source

PatentEP3746309B1Heat-sensitive recording material
Publication Date: 2026.01.28 MITSUBISHI HITEC PAPER EURO
  • EP3746309B1 patent drawingFigure 1
  • EP3746309B1 patent drawingFigure 2
  • EP3746309B1 patent drawingFigure 3

AI summary

The invention relates to a heat-sensitive recording material comprising a substrate, a heat-sensitive recording layer which comprises N-(4-methylphenylsulfonyl)-N'-(3-(4-methylphenylsulfonyloxy)phenyl)urea and/or N-[2-(3-phenylureido)phenyl]benzol sulfonamide, and an intermediate layer which is arranged between the substrate and the heat-sensitive recording layer and which comprises calcined aluminum silicate. The invention also relates to a method for producing a heat-sensitive recording material and to the use of calcined aluminum silicate in an intermediate layer of a heat-sensitive recording material.