On-press-development-type lithographic printing plate precursor, lithographic printing plate production method, and lithographic printing method
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Solution Overview
Problem
Existing on-press development type lithographic printing plate precursors face issues with visibility and contamination during printing due to components like discoloring compounds adhering to the precursor surface, leading to non-image area contamination.
Innovation Solution
The lithographic printing plate precursor features an aluminum support with an anodic oxide film having a specific surface shape and micropores, along with a polymerizable compound and infrared absorber, to enhance visibility and suppress contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a discoloring compound is added to the image-recording layer for on-press development, then visibility is improved, but contamination occurs because the compound adheres to the precursor surface
Solution Approach 1:
The patent applies anodization to create a porous oxide film on the aluminum support surface. This porous structure allows the discoloring compound to be incorporated into the image-recording layer through capillary action during the anodization process, enabling the compound to be held within the porous structure rather than adhering to the surface, thus maintaining visibility while preventing contamination.
Solution Approach 2:
The anodized oxide film acts as an intermediary layer between the aluminum support and the image-recording layer. This intermediary porous film facilitates the incorporation of the discoloring compound into the image-recording layer while preventing direct adhesion to the support surface, thereby resolving the contradiction between visibility enhancement and contamination prevention.
2Illumination intensity
If the surface of the aluminum support is made rough to improve visibility, then contamination increases due to increased surface area for adhesion
Solution Approach 1:
Instead of creating a rough surface through mechanical means, the patent uses anodization to create a controlled porous oxide film. This porous structure provides surface area for visibility enhancement while the controlled pore structure prevents uncontrolled adhesion of discoloring compounds, thus improving visibility without increasing contamination.
Solution Approach 2:
The patent changes the surface parameters through anodization by controlling the pore size, distribution, and depth of the oxide film. This controlled modification of surface parameters allows for visibility enhancement while preventing the uncontrolled adhesion that would occur with mechanically rough surfaces, thereby reducing contamination.
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 improved visibility and reduces contamination, ensuring high-quality printing with reduced surface adherence of discoloring compounds, thus enhancing printing durability and contamination suppressiveness.
Implementation Method 1
an anodic oxide film having a specific surface shape and micropores
Implementation Method 2
the image-recording layer contains an infrared absorber, a polymerization initiator, and a polymerizable compound
Implementation Method 3
the image-recording layer contains an infrared absorber, a polymerization initiator, and a polymerizable compound
Data Source
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AI summary
Provided is an on-press development type lithographic printing plate precursor having an aluminum support, an image-recording layer, and an outermost layer in this order, in which the image-recording layer contains an infrared absorber, a polymerization initiator, and a polymerizable compound, the aluminum support has an aluminum plate and an anodic oxide film of aluminum disposed on the aluminum plate, a steepness a45 that represents an area ratio of a component having a wavelength of 0.2 µm to 2 µm in a portion having an inclination of 45° or more within a surface of the anodic oxide film on a side of the image-recording layer is 30% or less, and the outermost layer contains a discoloring compound. Also provided are a method of preparing lithographic printing plate and a lithographic printing method in which the on-press development type lithographic printing plate precursor is used.