Negative-Working Lithographic Printing Plate Precursor with Urea Bond Polymer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current lithographic printing plate precursors face challenges in achieving satisfactory on-press developability, fine line reproducibility, and printing durability, especially with UV inks, and generate scum that impairs press maintenance and print quality.
Innovation Solution
A negative-working lithographic printing plate precursor with a photopolymerizable layer containing a polymer compound having a urea bond in the main chain and a hydrophilic group, which facilitates removal by fountain solution or water-soluble resin-containing aqueous solution, reducing scum formation and enhancing image strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional photopolymerizable layer is used, then the plate can be manufactured with standard materials, but on-press developability is insufficient and scum is generated
Solution Approach 1:
The patent changes the chemical parameters of the photopolymerizable layer by incorporating specific polymer compounds with controlled carboxylic acid content (less than 0.05 meq/g) and specific functional groups. This parameter optimization enables the layer to be effectively removed by fountain solution on-press without generating scum, resolving the contradiction between developability and harmful byproduct generation.
Solution Approach 2:
The patent uses a composite photopolymerizable layer containing multiple components: polymer compounds with specific structures, photopolymerization initiators, and other auxiliary agents. This composite formulation achieves both excellent on-press developability and minimal scum generation by synergistic interaction of components, allowing the layer to dissolve cleanly in fountain solution.
2Reliability
If the photopolymerizable layer is made more soluble for better on-press development, then developability improves, but image strength and printing durability deteriorate
Solution Approach 1:
The patent optimizes the carboxylic acid content parameter to less than 0.05 meq/g and controls the molecular weight and structure of polymer compounds. This precise parameter control creates a balance where the photopolymerizable layer is sufficiently soluble for on-press development by fountain solution while maintaining adequate image strength and printing durability through controlled polymer architecture.
Solution Approach 2:
The patent creates different functional zones within the photopolymerizable layer through selective distribution of components. The polymer compounds provide localized solubility for development while other components maintain image strength, achieving both on-press developability and printing durability through spatial-functional differentiation within the layer structure.
3Ease of operation
If conventional developing solutions are used, then the process is simple, but fine line reproducibility is insufficient
Solution Approach 1:
The patent modifies the chemical composition parameters of the photopolymerizable layer to include specific polymer compounds with controlled solubility characteristics. This enables the layer to be effectively removed by conventional fountain solution used in simple on-press development processes while achieving excellent fine line reproducibility through optimized dissolution behavior that preserves fine image details.
4Duration of action of stationary object
If the photopolymerizable layer is designed for UV ink compatibility, then printing durability with UV inks improves, but scum generation increases
Solution Approach 1:
The patent optimizes the carboxylic acid content to less than 0.05 meq/g and controls the molecular structure of polymer compounds to achieve UV ink resistance while preventing scum generation. The specific parameter ranges create a photopolymerizable layer that forms durable images with UV inks yet dissolves cleanly in fountain solution during on-press development without producing harmful scum.
Solution Approach 2:
The patent converts the potential harm of scum generation into a benefit by designing polymer compounds that interact favorably with fountain solution. The controlled carboxylic acid content and molecular structure ensure that the layer removes completely and cleanly during development, transforming what could be a harmful scum-forming process into a clean dissolution that enhances both UV ink compatibility and press maintenance.
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 provides excellent on-press developability, fine line reproducibility, and printing durability, reducing waste and scum generation, and supports high-quality printing with UV inks.
Implementation Method 1
a photopolymerizable layer that contains a polymer compound having a urea bond in the main chain
Implementation Method 2
that has a hydrophilic group, which facilitates removal by fountain solution or water-soluble resin-containing aqueous solution
Implementation Method 3
a polymer compound that has the urea bond in the main chain
Data Source
Figure 1
Figure 2
AI summary
A negative-working lithographic printing plate precursor is disclosed that can be developed on the press without going through a development processing step, and a method of lithographic printing is also disclosed that uses this negative-working lithographic printing plate precursor. Also disclosed are a negative-working lithographic printing plate precursor that can be developed by a water-soluble resin-containing aqueous solution and a method of lithographic printing that uses this negative-working lithographic printing plate precursor. A negative-working lithographic printing plate precursor is provided that exhibits an excellent fine line reproducibility in nonimage areas even when printing is performed using ultraviolet-curing ink (UV ink). Also provided is a negative-working lithographic printing plate precursor that exhibits an excellent combination of fine line reproducibility and printing durability and that resists the production of scum during on-press development. The negative-working lithographic printing plate precursor has a support and has thereon a photopolymerizable layer that contains a polymer compound that has the urea bond in the main chain and a hydrophilic group and a carboxylic acid content less than 0.05 meq/g. The method of lithographic printing uses this negative-working lithographic printing plate precursor.