Patent ID: 6132938
Filing Date: 2000-10-17
Classification: B41C,G03F,Y10S

Abstract:
A process for making a lithographic printing plate which comprises subjecting a lithographic printing plate precursor having a silver thin film on a grained and anodized aluminum base to exposure by a heat-mode laser beam whereby removing said silver thin film, wherein said aluminum base has a surface activity which can form physical development silver in an amount of 0.5 g/m.sup.2 or more when the base is processed by using the following Physical development solution 1 at 23.degree. C. for 30 minutes:Physical development solution 1 wherein 1 part by volume of Solution B is added to 5 parts by volume of Solution A; Solution A: Anhydrous sodium sulfite 180 g 10% Silver nitrate solution 75 ml Make up to 1000 ml with addition of water, Solution B: Anhydrous sodium sulfite 20 g Hydroquinone 20 g Make up to 1000 ml with addition of water.