Lithographic Printing Plate Precursor On-Press Development
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lithographic printing plate precursors face challenges in achieving a balance between ink receptivity and printing durability, particularly during on-press development, where the incorporation of hydrophilic polymers and inorganic stratiform compounds can lead to interlayer mixing and degradation of ink receptivity.
Innovation Solution
A lithographic printing plate precursor is developed with an image-recording layer containing an infrared absorbing dye, polymerization initiator, polymerizable compound, and binder polymer with an alkylene oxide group, along with a protective layer comprising a hydrophilic polymer with specific repeating units that inhibit mixing with the image-recording layer, ensuring good ink receptivity and on-press development properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a hydrophilic polymer is incorporated into the protective layer to improve on-press development property, then the on-press development property is improved, but the polymer mixes with the image-recording layer causing degradation of ink receptivity and printing durability
Solution Approach 1:
A low molecular weight compound containing a carboxylic acid group is introduced as an intermediary substance between the hydrophilic polymer in the protective layer and the image-recording layer. This compound prevents direct contact and mixing between the polymer and image-recording layer components, thereby maintaining ink receptivity while preserving the improved on-press development property provided by the hydrophilic polymer
Solution Approach 2:
The harmful mixing effect is prevented by extracting or blocking the interaction pathway between the hydrophilic polymer and the image-recording layer through the intermediary low molecular weight compound, allowing the beneficial on-press development property to be retained without the detrimental interlayer mixing
2Duration of action of stationary object
If an inorganic stratiform compound is incorporated into the protective layer to improve printing durability, then the printing durability is improved, but it promotes interlayer mixing with the image-recording layer degrading ink receptivity
Solution Approach 1:
The low molecular weight compound containing a carboxylic acid group serves as a barrier between the inorganic stratiform compound and the image-recording layer, preventing direct interaction that would cause interlayer mixing and ink receptivity degradation, while allowing the inorganic compound to maintain its printing durability enhancement function
3Manufacturing precision
If conventional development processing is used to remove unnecessary image-recording layer, then the image-forming property is achieved, but environmental pollution from waste liquid discharge occurs
Solution Approach 1:
The lithographic printing plate precursor is designed to enable on-press development where the plate itself undergoes development directly on the printing machine without requiring separate wet development processing. This self-service approach eliminates the need for conventional development tanks and waste liquid disposal systems, achieving both image-forming property and environmental protection
4Device complexity
If a lithographic printing plate precursor capable of on-press development is used, then simplified plate making operation is achieved, but balance between ink receptivity and on-press development property deteriorates
Solution Approach 1:
The low molecular weight compound acts as a protective intermediary that allows simplified on-press development operation while preventing the chemical interaction that would otherwise degrade ink receptivity, thus maintaining both operational simplicity and printing quality
Solution Approach 2:
The introduction of the low molecular weight compound changes the chemical parameters of the protective layer, creating a barrier that controls the interaction between layers and maintains the balance between ink receptivity and on-press development capability
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 a lithographic printing plate with enhanced ink receptivity and printing durability, maintaining ink receptivity even with specific color inks and improving on-press development performance without deterioration over time.
Implementation Method 1
contains (A) an infrared absorbing dye
Implementation Method 2
exposed through a mask, for example, a lith film, and then subjected to development processing
Implementation Method 3
contains (B) a polymerization initiator, (C) a polymerizable compound
Data Source
AI summary
A lithographic printing plate precursor includes, in the following order: a support; an image-recording layer which is capable of forming an image by removing an unexposed area of the image-recording layer with at least one of printing ink and dampening water on a printing machine after exposure and contains an infrared absorbing dye, a polymerization initiator, a polymerizable compound and a binder polymer having an alkylene oxide group; and a protective layer containing a hydrophilic polymer which contains at least a repeating unit represented by the formula (1) as defined herein, a repeating unit represented by the formula (2) as defined herein, and a repeating unit represented by the formula (4) as defmed herein, and in which a content of the repeating unit represented by the formula (4) is from 0.3 to 5.0% by mole based on total repeating units of the hydrophilic polymer.