| 摘要 |
<p>It is an object of the present invention to provide a method for preparing a lithographic printing plate, which permits the inhibition of any reduction in the developing properties even after the elapse of time and/or the repeated use, which is not accompanied by the formation of any sludge in the developer even if a large number of plates are developed, which can ensure a good ability of developing nonimage areas and which can provide a printing plate free of any scumming on non-image areas. It is also an object of the present invention to provide a method for preparing a lithographic printing plate, which is never accompanied by any trouble such as blinding during printing operations, which scarcely damages image portions during development, which can provide images having high strength and which can provide a printing plate having high printing durability. ÄMeans of SolutionÜ A method for preparing a lithographic printing plate comprises the steps of subjecting, to imagewise exposure, a presensitized plate for use in making a lithographic printing plate comprising an aluminum substrate provided thereon with a light-sensitive layer formed from a photopolymerizable light-sensitive composition, which comprises a compound having an ethylenically unsaturated double bond, a photopolymerization initiator and a polyurethane resin binder and then developing the imagewise exposed plate with a developer containing an inorganic alkaline agent and a nonionic surfactant, carrying a polyoxyalkylene ether group, and having a pH value ranging from 10.0 to 12.5 and an electrical conductivity ranging from 3 to 30 mS/cm.</p> |
