Method for preparing a lithographic printing plate and a light-sensitive material used therefor

摘要

A method for preparing a lithographic printing plate and the light-sensitive material for lithographic printing plates are disclosed. The method is comprised of providing a light-sensitive material which is comprised of an aluminum or aluminum alloy support having provided thereon a hydrophilic surface layer of aluminum oxide in an amount of 0.2 to 2.8 g/m2, having provided thereon a light-sensitive layer and a photoconductive insulating layer which may be present in separate layers in this order or combined in a single layer. The material thus-provided is imagewise exposed and then electrophotographically processed in order to form an electrostatic latent image on the photoconductive insulating layer. Development of the electrostatic latent image is then carried out with developer particles which are opaque to light to which the light-sensitive layer is sensitive. The light-sensitive material is then exposed through the developed image and the exposed or unexposed areas of the light-sensitive layer are removed by themselves or in combination with the photoconductive insulating layer. The lithographic printing plate prepared by the exposed method has excellent resolving power and does not cause printing stains.