Abstract: A presensitized plate comprising a support for a lithographic printing plate including an anodized layer formed on an aluminum plate and a recording layer recordable by infrared laser exposure on the support, wherein in a section of the anodized layer after the recording layer is provided, an atomicity ratio of carbon to aluminum (C/Al) represented by Auger Electron Spectroscopic analysis is 1.0 or less. In the case of being used as an on-machine development type, it exhibits a good on-machine development characteristic, a high sensitivity, a high press life, and high scum resistance during printing and while left (ink discharging). In the case of being used as a conventional thermal positive or negative working type, it exhibits an efficient use of heat for image formation, a high sensitivity, a high press life, and a slight possibility of scum occurrence at non-image areas.

Abstract: A lithographic printing plate precursor is disclosed, comprising a metal support having formed thereon an anodic oxide film, and an image-forming layer containing a light-to-heat converting agent, or a light-sensitive layer capable of image-forming with infrared laser exposure provided in this order from the support.

Abstract: Disclosed is a presensitized plate, having an anodized layer and recording layer provided on a support for a lithographic printing plate, wherein the anodized layer is provided by subjecting an aluminum plate to graining and anodizing treatments. The presensitized plate has wide development latitude, makes it difficult for scratch-like non-image portions to be generated and facilitates handling in usual operation.

Abstract: Objects of the present invention are to provide a positive working presensitized plate of a thermal type, which has damage resistance, and which is handled easily in conventional operation, high in sensitivity and excellent in press life when used as a lithographic printing plate, and to provide a support for a lithographic printing plate, which is suitably used for the same. The objects have been achieved by a support for a lithographic printing plate obtained by performing graining treatment, alkali etching treatment and anodizing treatment on an aluminum plate, wherein a ratio of a real area of a surface thereof to an apparent area of the surface set larger by 1.3 to 1.8 times, comprising a pit having an average diameter of 0.3 to 1.

Abstract: Objects of the present invention are to provide a positive working presensitized plate of a thermal type, which has damage resistance, and which is handled easily in conventional operation, high in sensitivity and excellent in press life when used as a lithographic printing plate, and to provide a support for a lithographic printing plate, which is suitably used for the same. The objects have been achieved by a support for a lithographic printing plate obtained by performing graining treatment, alkali etching treatment and anodizing treatment on an aluminum plate, wherein a ratio of a real area of a surface thereof to an apparent area of the surface set larger by 1.3 to 1.8 times, comprising a pit having an average diameter of 0.3 to 1.

Abstract: A presensitized plate comprising a support for a lithographic printing plate including an anodized layer formed on an aluminum plate and a recording layer recordable by infrared laser exposure on the support, wherein in a section of the anodized layer after the recording layer is provided, an atomicity ratio of carbon to aluminum (C/Al) represented by Auger Electron Spectroscopic analysis is 1.0 or less. In the case of being used as an on-machine development type, it exhibits a good on-machine development characteristic, a high sensitivity, a high press life, and high scum resistance during printing and while left (ink discharging). In the case of being used as a conventional thermal positive or negative working type, it exhibits an efficient use of heat for image formation, a high sensitivity, a high press life, and a slight possibility of scum occurrence at non-image areas.

Abstract: A lithographic printing plate precursor is disclosed, comprising a metal support having formed thereon an anodic oxide film, and an image-forming layer containing a light-to-heat converting agent, or a light-sensitive layer capable of image-forming with infrared laser exposure provided in this order from the support.

Abstract: Disclosed are a printing plate precursor having an anodized titanium film layer on a surface thereof; a process for lithography which comprises image-wise exposing the surface of the printing plate precursor to an actinic light, bringing the exposed surface into contact with a printing ink to form a printing surface where the image areas have received the ink, and using the resultant printing plate to conduct printing; and the process for lithography described above which further comprises cleaning the surface of the printing plate after completion of the printing to remove the remaining ink from the surface, subsequently heating the printing plate precursor at 80 to 500° C., and then repeatedly using the printing plate precursor.

Abstract: Disclosed is a presensitized plate, having intermediate and photosensitive layers sequentially provided on a support for a lithographic printing plate, which is provided by subjecting an aluminum plate to graining, alkali etching and anodizing treatments. The amount of alkali etching is set in a range of 0.5 to 4 g/m2 for the alkali etching treatment, and an average thickness of thinnest 10% of the photosensitive layer on convex portions of a surface of the support is set in a range of 0.2 to 2 &mgr;m. This presensitized plate has wide development latitude, makes it difficult for scratch-like non-image portions to be generated, and facilitates handling in usual operation.