Lithographic Plate Outermost Layer Contact Angle for Ink and Development

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Solution Overview

Problem

Existing lithographic printing plate precursors face a trade-off between printing ink receptivity and on-press developability, with improvements in one often leading to deterioration in the other.

Innovation Solution

A lithographic printing plate precursor with a specific outermost layer configuration, containing a hydrophobic polymer and a hydrophilic polymer, and a contact angle optimized for both exposed and non-exposed areas, enhancing both receptivity and on-press developability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the lithographic printing plate precursor is improved in on-press developability, then the developability during on-press development is improved, but the printing ink receptivity deteriorates

Engineering Contradiction:
Improveon-press developabilityVSAvoidprinting ink receptivity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the contact angle of the outermost layer surface (5° to 40°) and adjusting the molecular weight and content of the polymer (10,000 to 1,000,000 molecular weight, 1 to 50 parts by mass). These parameter optimizations enable the surface to achieve balanced properties that simultaneously improve on-press developability while maintaining printing ink receptivity, resolving the technical contradiction between these two opposing requirements

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the lithographic printing plate precursor is improved in printing ink receptivity, then the receptivity is improved, but the on-press developability deteriorates

Engineering Contradiction:
Improveprinting ink receptivityVSAvoidon-press developability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent resolves this contradiction through parameter changes by optimizing the contact angle range (5° to 40°) and polymer characteristics (molecular weight 10,000 to 1,000,000, content 1 to 50 parts by mass). These controlled parameter changes enable the outermost layer to maintain appropriate hydrophobicity for ink receptivity while ensuring sufficient hydrophilicity for on-press development, achieving simultaneous improvement of both properties

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a hydrophobic polymer is added to the outermost layer, then the printing ink receptivity is improved, but the on-press developability deteriorates

Engineering Contradiction:
Improveprinting ink receptivityVSAvoidon-press developability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies parameter changes by controlling the contact angle (5° to 40°) and limiting the hydrophobic polymer content to 1 to 50 parts by mass. This quantitative control transforms the hydrophobic polymer from a harmful factor into a beneficial component, enabling it to enhance ink receptivity while the contact angle control ensures sufficient hydrophilicity for on-press development

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining hydrophobic polymer with other components in the outermost layer to create a composite structure. This composite approach allows the hydrophobic polymer to provide ink receptivity enhancement while the overall composition maintains the contact angle within the optimal range for on-press developability, resolving the contradiction between these two functions

Inventive Principle:
Principle #40Composite 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 configuration achieves improved printing ink receptivity and on-press developability without compromising the other, ensuring high-quality printing performance.

Implementation Method 1

a contact angle of a water droplet on a surface of the outermost layer that is measured 2 seconds after the water droplet is landed by an airborne water droplet method is 5° or more and 40° or less

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Data Source

PatentEP4159457B1On-press development type lithographic printing plate precursor and method of preparing a lithographic printing plate
Publication Date: 2025.12.31 FUJIFILM CORP
  • EP4159457B1 patent drawingFigure 1~2
  • EP4159457B1 patent drawingFigure 3
  • EP4159457B1 patent drawing

AI summary

The present disclosure provides an on-press development type lithographic printing plate precursor having a support, an image-recording layer, and an outermost layer in this order, in which the outermost layer contains a hydrophobic polymer, and a contact angle of a water droplet on a surface of the outermost layer that is measured 2 seconds after the water droplet is landed by an airborne water droplet method is less than 36°. The present disclosure also provides applications of the on-press development type lithographic printing plate precursor.