Pressure Phase Transition Layer Thickness Control for Printed Material Bonding

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Solution Overview

Problem

Existing printed materials with pressure-bonding surfaces experience unevenness in pressure-bonding strength due to variations in the thickness of the pressure phase transition layer, leading to local breakage or peeling, especially in Z-folded configurations where the influence of unevenness is significant.

Innovation Solution

A printed material with a recording medium having a pressure-bonding surface where the average thickness of the pressure phase transition layer on the image portion is greater than on the non-image portion, and the thickness of the pressure phase transition layer is within specific ranges (0.5 µm to 5.0 µm) to ensure uniform pressure-bonding strength, using a composition of styrene-based and (meth)acrylate-based resins with specific mass percentages and glass transition temperature differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the average thickness of the pressure phase transition layer on the image portion is made equal to that on the non-image portion, then the manufacturing process is simplified, but unevenness in pressure-bonding strength occurs leading to local breakage or peeling

Engineering Contradiction:
Improvesimplicity of pressure phase transition layer formationVSAvoiduniformity of pressure-bonding strength
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The pressure phase transition layer is designed with spatially varying thickness: thicker on image portions (0.5-5.0 µm) and thinner on non-image portions (0.1-2.0 µm). This local differentiation ensures that image areas receive sufficient pressure bonding strength while non-image areas maintain appropriate bonding, eliminating the unevenness that would occur with uniform thickness application.

Inventive Principle:
Principle #3Local quality

2Strength

If the pressure phase transition layer thickness on the image portion is increased to improve pressure-bonding strength, then bonding strength increases, but the layer thickness becomes non-uniform causing manufacturing complexity

Engineering Contradiction:
Improvepressure-bonding strength on image portionVSAvoidcomplexity of controlling pressure phase transition layer thickness distribution
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention specifies precise thickness parameter ranges: image portion layer thickness of 0.5-5.0 µm and non-image portion thickness of 0.1-2.0 µm. These quantified parameters provide clear manufacturing targets that balance pressure-bonding strength requirements with manufacturability, avoiding excessive complexity while ensuring sufficient bonding performance.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If a uniform pressure phase transition layer is applied across the entire surface, then application process is simplified, but Z-folded configurations exhibit significant unevenness in pressure-bonding strength

Engineering Contradiction:
Improvesimplicity of pressure phase transition layer applicationVSAvoidpressure-bonding strength uniformity in Z-folded configuration
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The pressure phase transition layer thickness is locally optimized for different functional areas: image portions receive 0.5-5.0 µm thickness for strong bonding, while non-image portions receive 0.1-2.0 µm thickness. This local differentiation specifically addresses Z-folded configuration requirements by ensuring uniform pressure-bonding strength across all folded surfaces, preventing the unevenness that would occur with uniform application.

Inventive Principle:
Principle #3Local quality

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 solution reduces unevenness in pressure-bonding strength between surfaces, preventing local breakage or peeling, even in Z-folded configurations, by maintaining consistent pressure-bonding strength across the material, enhancing the durability and reliability of the printed material.

Implementation Method 1

a pressure-bonding surface on which an image portion and a pressure phase transition layer are formed

Methodology Applied
Scientific EffectPressure phase transition: Phase Change

Implementation Method 2

the pressure phase transition layer contains: a styrene-based resin containing styrene and an additional vinyl monomer as polymerization components; and a (meth)acrylate-based resin containing at least two (meth)acrylates as polymerization components such that the mass percentage of the (meth)acrylates with respect to the total mass of the polymerization components of the (meth)acrylate-based resin is 90% by mass or more, the pressure phase transition layer having at least two glass transition temperatures

Methodology Applied
Scientific EffectGlass transition:

Data Source

PatentEP4067101B1Printed material and method for producing printed material
Publication Date: 2023.09.06 FUJIFILM BUSINESS INNOVATION CORP
  • EP4067101B1 patent drawingFigure 1
  • EP4067101B1 patent drawingFigure 2
  • EP4067101B1 patent drawingFigure 3

AI summary

A printed material includes: a recording medium having a pressure-bonding surface on which an image portion and a pressure phase transition layer are formed, the recording medium being folded upon the recording medium and pressure-bonded; or a recording medium having a pressure-bonding surface on which an image portion and a pressure phase transition layer are formed and an additional recording medium, the recording medium and the additional recording medium being stacked and pressure-bonded together. The average thickness of the pressure phase transition layer formed on the image portion on the pressure-bonding surface of the recording medium is larger than the average thickness of the pressure phase transition layer formed on a non-image portion on the pressure-bonding surface of the recording medium.