Lithographic Plate Precursor Composition Against Humidity-Induced Aggregation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing lithographic printing plate precursors face issues with development defects in high-humidity environments and loss of developability over time, particularly due to aggregation of onium polymerization initiators.

Innovation Solution

Incorporating a compound A, an onium salt with a lower shape index than the onium polymerization initiator, into the image-recording layer to suppress aggregation and improve dispersibility, ensuring excellent developability and visibility even after prolonged exposure to high humidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an onium polymerization initiator is used in the image-recording layer, then polymerization reaction efficiency is improved, but aggregation occurs leading to loss of developability over time

Engineering Contradiction:
Improvepolymerization reaction efficiencyVSAvoiddevelopability over time
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

A compound (Formula 1) acting as an intermediary substance is introduced between the onium polymerization initiator and the environment. This compound suppresses aggregation of the onium polymerization initiator through molecular interaction, thereby maintaining developability over time while preserving polymerization efficiency. The compound serves as a protective mediator that prevents harmful aggregation without interfering with the intended polymerization function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The chemical environment parameters of the image-recording layer are modified by adding compound (Formula 1). This changes the molecular distribution parameters and suppresses aggregation tendencies. The addition alters the physical-chemical parameters of the system to maintain initiator dispersibility and prevent loss of developability while preserving polymerization reactivity.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If the lithographic printing plate precursor is stored in high-humidity environment, then availability is improved, but aggregation of onium polymerization initiator occurs reducing developability

Engineering Contradiction:
Improveavailability in high-humidity environmentVSAvoiddevelopability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

Compound (Formula 1) acts as a protective intermediary that shields the onium polymerization initiator from humidity-induced aggregation. The compound interacts with the initiator to prevent moisture from causing aggregation, thereby maintaining developability even when stored in high-humidity environments. This intermediary protection enables the plate precursor to be stored and transported under less stringent humidity conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If on-press development method is used, then environmental friendliness is improved by eliminating wet treatment, but development defects occur due to aggregation

Engineering Contradiction:
Improvewaste liquid from wet treatmentVSAvoiddevelopment quality
Core Design Contradiction:
Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

By introducing compound (Formula 1) as an intermediary that suppresses initiator aggregation, the patent enables on-press development to proceed without the harmful wet treatment steps. The compound ensures that even without conventional alkaline development, the initiator remains sufficiently dispersed to allow clean differentiation between image and non-image areas, thereby eliminating waste liquid generation while maintaining development quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The compound (Formula 1) performs preliminary protective action by suppressing aggregation before the on-press development process occurs. This pre-protection ensures that when on-press development is applied, the initiator is already in a dispersed state that prevents development defects, allowing the environmentally friendly on-press method to achieve high manufacturing precision without conventional wet development.

Inventive Principle:
Principle #10Preliminary action

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 lithographic printing plate precursor maintains excellent developability and visibility, reducing development defects and enhancing printing durability by using an onium salt with a lower shape index to inhibit aggregation of the onium polymerization initiator.

Implementation Method 1

the image-recording layer contains an onium polymerization initiator, an onium salt formed of a cation having a shape index lower than a shape index of a cationic moiety of the onium polymerization initiator

Methodology Applied
Scientific EffectElectrostatic repulsion: Ion Repulsion/Attraction

Implementation Method 2

the image-recording layer contains an onium polymerization initiator, an infrared absorber, a chromogenic agent, and a compound A

Methodology Applied
Scientific EffectInfrared absorption: Absorption (EM radiation)

Implementation Method 3

the image-recording layer contains a radical initiator, a radically polymerizable component, and a radiation absorption compound

Methodology Applied
Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentEP4245542B1Lithographic printing plate precursor, method of preparing lithographic printing plate, and lithographic printing method
Publication Date: 2025.12.10 FUJIFILM CORP
  • EP4245542B1 patent drawingFigure 1
  • EP4245542B1 patent drawingFigure 2
  • EP4245542B1 patent drawingFigure 3~4

AI summary

Provided are: a lithographic printing plate precursor having a support and an image-recording layer on the support, in which the image-recording layer contains an onium polymerization initiator, a borate compound, an infrared absorber, a chromogenic agent, and a compound A which is an onium salt formed of a cation having a shape index lower than a shape index of a cationic moiety of the onium polymerization initiator; a method of preparing a lithographic printing plate using the lithographic printing plate precursor; and a lithographic printing method.