Flexographic Printing Plate Adhesive for Solvent-Resistant Bonding

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Solution Overview

Problem

Flexographic printing plates face issues with adhesive layers separating from the supporting body and losing adhesion due to solvent exposure from ink, leading to difficulty in reusing the plates.

Innovation Solution

A flexographic printing original plate design featuring an adhesive layer composed of a polyester resin, an isocyanate compound, and a xylene-based resin with a melting point or softening point of 100°C or less, which enhances adhesion and solvent resistance by forming a crosslinked structure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the adhesive layer contains a thermoplastic elastomer and acrylate compound to achieve high adhesion to the photosensitive resin layer, then adhesion to the photosensitive resin layer is improved, but adhesion to the supporting body becomes insufficient and solvent resistance is reduced

Engineering Contradiction:
Improveadhesion to photosensitive resin layerVSAvoidadhesion to supporting body and solvent resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention changes the chemical composition parameters of the adhesive layer by incorporating a xylene-based resin with specific melting point (100°C or less) and controlled content (10-30 parts by mass per 100 parts polyester resin), along with isocyanate compound, to achieve both high adhesion and solvent resistance simultaneously

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The adhesive layer is designed as a composite material system comprising polyester resin, xylene-based resin, and isocyanate compound, where each component contributes specific properties: polyester resin provides base adhesion, xylene-based resin enhances adhesion to supporting body, and isocyanate compound forms crosslinked structure for solvent resistance

Inventive Principle:
Principle #40Composite materials

2Strength

If the adhesive layer is made with high adhesion components to prevent separation during peeling, then adhesion force is improved, but solvent resistance is reduced causing adhesion loss when in contact with ink

Engineering Contradiction:
Improveadhesion forceVSAvoidsolvent-induced adhesion loss
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention modifies the adhesive layer composition by adding xylene-based resin with specific melting point characteristics and isocyanate compound content to create a balanced system that maintains adhesion strength while resisting solvent attack

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The adhesive layer is designed with differentiated functional zones at the molecular level: the polyester resin and xylene-based resin provide adhesion to the supporting body, while the isocyanate compound creates a crosslinked network structure that specifically resists ink solvent penetration

Inventive Principle:
Principle #3Local quality

3Strength

If the adhesive layer composition is optimized for adhesion, then adhesion to supporting body is improved, but the complexity of achieving both adhesion and solvent resistance increases

Engineering Contradiction:
Improveadhesion to supporting bodyVSAvoidadhesive layer composition complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention simplifies the composition design by establishing specific parameter ranges: xylene-based resin content of 10-30 parts by mass per 100 parts polyester resin, and isocyanate compound at 1-15 parts by mass per 100 parts polyester resin, which simultaneously achieves adhesion and solvent resistance

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 adhesive layer maintains high adhesion to both the supporting body and photosensitive resin layer, even when exposed to ink solvents, ensuring stable reuse of the printing plate.

Implementation Method 1

the adhesive layer contains the following component (c) and a reaction product of the following components (a) and (b): (a) a polyester resin, (b) an isocyanate compound

Methodology Applied
Scientific EffectCrosslinking reaction: Chemical Bonding

Data Source

PatentEP4223533B1Flexographic printing original plate
Publication Date: 2025.08.13 SUMITOMO RIKO CO LTD
  • EP4223533B1 patent drawingFigure 1
  • EP4223533B1 patent drawingFigure 2(a)~2(e)
  • EP4223533B1 patent drawing

AI summary

The present invention provides a flexographic printing original plate which comprises an adhesive layer that exhibits excellent solvent resistance and excellent adhesion to a supporting body. The present invention provides a flexographic printing original plate 10 which sequentially comprises, on a surface of a supporting body 12, an adhesive layer 14 and an elastic layer 16, wherein the supporting body 12 contains a polyester resin and the adhesive layer 14 contains the components (a), (b) and (c) described below. (a) a polyester resin (b) an isocyanate compound (c) a xylene resin which has a melting point or softening point of 100°C or less.