Lithographic Printing Plate Edge Polymer Coating for Adhesion Prevention

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Solution Overview

Problem

Lithographic printing plate precursors face issues with adhesion to interleaving paper and contamination within devices during the exposure process, leading to edge stains and equipment contamination, especially when treated with solutions containing organic solvents and surfactants.

Innovation Solution

A lithographic printing plate precursor with an image recording layer on a support, where the end portions are coated with a specific polymer solution containing polymers with amide, urethane, urea, ester, or carbonate bonds, and microgel particles, increasing polymer content by 10 mg/m² or more in the 5 mm region near the edges to prevent adhesion and contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the end portions are treated with a solution containing organic solvent and hydrophilic resin to prevent edge stain, then edge stain is reduced, but adhesion to interleaving paper deteriorates and contamination of device occurs

Engineering Contradiction:
Improveedge stainVSAvoidadhesion to interleaving paper and device contamination
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent applies different treatments to different regions of the lithographic printing plate precursor. Specifically, the end portions (within 5mm from the edge) are coated with a polymer solution containing amide, urethane, urea, ester, or carbonate bonds, while the central region undergoes conventional treatment with organic solvent and hydrophilic resin. This local differentiation allows the end portions to resist adhesion and contamination while the central region maintains proper developability and prevents edge stain.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The polymer coating on the end portions acts as an intermediary layer between the lithographic printing plate precursor and the interleaving paper or device surfaces. This intermediary polymer layer prevents direct contact and adhesion between the treated end portions and external surfaces, thereby eliminating both adhesion problems and contamination issues while maintaining the edge stain prevention function.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If treatment solution is applied to prevent edge stain, then edge stain is reduced, but the treated region adheres to interleaving paper during storage

Engineering Contradiction:
Improveedge stainVSAvoidadhesion strength to interleaving paper
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent creates a local quality difference by applying a polymer coating specifically to the end portions within 5mm from the edge. This polymer-coated region has different surface properties (lower adhesion) compared to the central region. During storage, the polymer-coated end portions do not adhere to interleaving paper, while the central region maintains normal adhesion characteristics for proper handling.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The polymer coating is applied in advance to the end portions before the plate is put into service. This preliminary coating creates a protective layer that prevents adhesion to interleaving paper during storage and handling, while still allowing the end portions to function properly in preventing edge stain during the printing process.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If treatment solution is used to prevent edge stain, then edge stain is reduced, but contamination of conveyance path and device occurs

Engineering Contradiction:
Improveedge stainVSAvoiddevice contamination
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The polymer coating on the end portions serves as an intermediary barrier that prevents the treatment solution and plate surface materials from contacting and contaminating the conveyance path and device surfaces. This intermediary layer is transfer-resistant and protects the surrounding equipment from contamination while maintaining the edge stain prevention function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extracts the problematic treatment solution application from the entire plate surface and confines it only to the end portions within 5mm from the edge. By removing the treatment solution from the central region, the source of contamination to the conveyance path and device is eliminated, while the end portion treatment continues to prevent edge stain.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP3656576B1Lithographic printing plate precursor and method of producing same
Publication Date: 2021.07.14 FUJIFILM CORP
  • EP3656576B1 patent drawingFigure 1~2
  • EP3656576B1 patent drawingFigure 3~4
  • EP3656576B1 patent drawingFigure 5

AI summary

Provided are a lithographic printing plate precursor for furnishing a lithographic printing plate in which adhesion to interleaving paper is prevented, contamination inside a device is prevented, and edge stain does not occur; a method of producing the same; and a printing method using the same. The lithographic printing plate precursor includes: a support; and an image recording layer on the support, in which a region of a surface of the lithographic printing plate precursor at a side of the image recording layer, which is from an end portion of the lithographic printing plate precursor to a portion inside the end portion by 5 mm, contains at least one polymer selected from polyamide, polyurethane, polyurea, polyester and polycarbonate, and has a content of the polymer per unit area which is greater than a content of the polymer per unit area in a region other than the above-described region by an amount of 10 mg/m2 or greater.