Anodized Aluminum Support Surface Area Control for Lithographic Printing Durability
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Solution Overview
Problem
Lithographic printing methods face challenges in achieving excellent printing durability and suppressing residual color in non-image areas, especially when using ultraviolet curable ink, due to environmental concerns related to waste liquids from wet treatments.
Innovation Solution
A lithographic printing method involving a lithographic printing plate precursor with an aluminum support and an image recording layer containing an acid color developing agent and an acid generator, where the aluminum support has a specific surface area and micropores, and using acidic dampening water to remove the non-image area, thereby reducing residual color.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wet development treatment is used to remove non-image area, then development effectiveness is improved, but environmental pollution from waste liquid increases
Solution Approach 1:
The invention extracts and eliminates the harmful wet development process from the printing plate preparation system. By using a dry photopolymerizable layer that can be removed without chemical developers, the harmful waste liquid generation is completely avoided while maintaining effective non-image area removal through simple mechanical or thermal means.
Solution Approach 2:
The invention employs a disposable photopolymerizable layer that can be easily removed after serving its purpose of defining the image area. This single-use layer eliminates the need for repeated chemical treatments, reducing environmental impact while maintaining effective development results.
2Reliability
If UV curable ink is used to improve printing durability, then printing durability is improved, but residual color in non-image area increases
Solution Approach 1:
The invention applies different properties to different areas: the photopolymerizable layer is designed to be removable in non-image areas while maintaining adhesion in image areas. This local differentiation allows UV ink to be applied durably only where needed, preventing residual color in non-image areas while maintaining printing durability in image areas.
Solution Approach 2:
The invention performs preliminary removal of the photopolymerizable layer in non-image areas before UV ink application. This preliminary action ensures that UV curable ink is applied only to areas where it should adhere, preventing residual color formation while allowing the ink to provide its full printing durability benefit in the image areas.
3Manufacturing precision
If photopolymerizable layer is used to define image area, then image area definition is improved, but residual color in non-image area occurs
Solution Approach 1:
The invention changes the physical and chemical parameters of the photopolymerizable layer to enable complete removal without residue. By adjusting composition, thickness, and removal conditions, the layer can be precisely defined for image areas and completely eliminated from non-image areas, preventing residual color while maintaining sharp image definition.
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 method provides excellent printing durability and effective suppression of residual color in non-image areas even with UV ink, by controlling the surface roughness and adhesiveness of the aluminum support, leading to improved printing performance and reduced environmental impact.
Implementation Method 1
the aluminum support includes an aluminum plate and an anodized aluminum film disposed on the aluminum plate
Implementation Method 2
the anodized film has micropores extending from a surface of the anodized film on the side of the image recording layer in a depth direction
Implementation Method 3
supplying acidic dampening water to the exposed lithographic printing plate precursor and removing a non-image area of the image recording layer
Implementation Method 4
an image recording layer that contains an acid color developing agent and an acid generator on the aluminum support
Data Source
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AI summary
Provided is a lithographic printing method including a preparing step of preparing a lithographic printing plate precursor which includes an aluminum support, and an image recording layer containing an acid color developing agent and an acid generator on the aluminum support, an exposing step of exposing the lithographic printing plate precursor, a developing step of supplying acidic dampening water to the exposed lithographic printing plate precursor and removing a non-image area of the image recording layer, and a printing step, in which the aluminum support includes an anodized aluminum film, the anodized film has micropores, and a value ΔS acquired by ΔS = (Sx - S0)/S0 × 100 (%) for a geometrically measured area So and an actual area Sx obtained by an approximate three-point method, based on three-dimensional data obtained by measuring 512 × 512 points in a range of 25 µm × 25 µm on the surface of the anodized film on the side of the image recording layer using an atomic force microscope, is 15% or greater and 60% or less.