Photosensitive planographic printing plate and fabrication process thereof

Abstract

A photosensitive planographic printing plate which can avoid quality defects such as residue films and the like and improve yield, and a fabrication process thereof. A coating layer of a region corresponding to an edge portion of a PS plate is preparatorily cleared by coating removal. Hence, pressure fogging which is formed by pressure at a time of cutting of a web will not occur.

Description

technical field [0001] The present invention relates to a photosensitive lithographic printing plate and a manufacturing method thereof, and more particularly, to a photosensitive lithographic printing plate excellent in multi-layer format on which a plurality of coatings are formed and a manufacturing method thereof. Floor. Background technique [0002] A photosensitive lithographic printing plate (hereinafter, referred to as a PS plate where appropriate) is usually produced by subjecting a support such as an aluminum plate in sheet or roll form to surface treatment such as sandblasting, anodizing, silicate treatment, etc. One or a proper combination of chemical treatments, etc.; then apply a photosensitive liquid and perform a drying treatment; then cut the PS plate into a desired size. This PS plate undergoes plate-making processes such as exposure, development treatment, gumming, etc., and is set in a printing press and coated with ink, thereby printing text, images, et...

AI Technical Summary

Problems solved by technology

[0008] In the aforementioned process of forming the cutout portion along the edge portion of the support, it is necessary to take out one PS plate at a time to form the cutout portion, which is not suitable for batch processing

In addition, when a defect such as a burr, a scratch, etc. occurs that will cause ink to stick, the ink sticks in the area where such a defective portion is formed, and finally the surface of the printing paper is stained with ink

Additionally, using the process of applying a desensitizing fluid to the cut surface, PS plates can stick together and can adversely affect handling, which can lead to developing problems

[0009] Also, even if burrs are prevented from occurring on the printing side during cutting, contamination occurs due to printing conditions

In addition, although the shape in which the cut edge portion is bent downward (curved toward the side opposite to the printing surface) contributes to improvement in contamination, there is a problem that the PS plate is damaged during transport through a plate making machine that performs exposure and development, etc. get stuck and will cause a transport failure

[0012] When, for example, a large burr is formed on the back side (the side opposite to the side where the surface treatment layer is formed), there arises a problem that the PS plate meanders when it is conveyed in the exposure device, the burr comes off and becomes waste, etc.

[0013] In addition, when shearing, large cracks are formed on the front surface (the surface where the surface treatment layer is formed), which affects printed products

Also, when performing multiple slits, there is a problem with loss between slits

However, the formation of rolled shapes for reducing edge contamination is more difficult, and there is a problem that there is a loss between cuts when multiple slitting is performed

In this mass production process, it is difficult to specify the cross-cut part before early coating, making it difficult to pre-coat according to the cross-cut part

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