Regenerative plate making and printing process, and plate making and printing apparatus

Abstract

The regenerative plate making and printing process, and plate making and printing apparatus of the present invention are applied to a printing system requiring a separate developing step independent of a printing step. In accordance with the present invention, by repeatedly conducting (A) a photosensitive layer-coating step of coating a photosensitive plate material onto a substrate to prepare a photosensitive lithographic plate having a photosensitive layer thereon; (B) an exposure step of exposing the photosensitive layer to image light; (C) a development step of supplying a plate-treating agent to the photosensitive layer to form developed images thereon; (D) a printing step of supplying a printing ink and dampening water to surfaces of the thus obtained images to conduct printing; and (E) a substrate regeneration step of removing the image portions from the substrate to regenerate the substrate, on the same rotary drum or conveyer, it is possible to considerably improve the working efficiency and stably provide high-quality images.

1 - 32 . (canceled)  
     
     
         33 . A process for producing a positive-type lithographic plate, comprising: 
 forming a photosensitive layer composed of a positive-type photosensitive composition containing (P-1) a light-heat converting material capable of converting light absorbed from a light source for image exposure into heat and (P-2) an alkali-soluble resin, on a surface of an aluminum substrate to obtain a positive-type photosensitive lithographic plate having a photosensitive layer thereon;    subjecting the photosensitive layer of the thus obtained positive-type photosensitive lithographic plate to scanning exposure using a laser source and then development treatment to form positive images thereon;    detachably fixing the positive-type lithographic plate on a plate cylinder of a printing machine to print a printing material with ink;    removing the positive images formed on the surface of the aluminum substrate while keeping the positive-type lithographic plate fixed on the plate cylinder, to regenerate the aluminum substrate; and    forming a photosensitive layer composed of the positive-type photosensitive composition containing the components (P-1) and (P-2) again on the surface of the regenerated aluminum substrate, followed by subjecting the photosensitive layer to scanning exposure using the laser source and then development treatment again to form the positive images thereon.