The print edition basic plate, in photoengraving manner of the print edition which uses that and on the print mannered null water-proof base material which

摘要

PROBLEM TO BE SOLVED: To provide a printing plate original plate of superior sharpness to be exposed by infrared ray laser, provided with exposure visible picture properties and forming a lithographic printing plate without the development using a liquid and also provide a method for making a printing plate using the printing plate original plate and a printing method using the printing plate. ;SOLUTION: A printing plate original plate is provided with a recording layer containing (A) a photothermic conversion agent provided with absorbability on a wave length range of 600 nm or more and (B) a compound generating acid, base or radical by light or heat and a compound changing color by the relative action with the generated acid, base or radical on a water-resistant substrate. The peak of absorption spectrum of (A) exists on the wave length range of 600 nm or more, and at least one of roots of the absorption spectrum of (A) exists in the range of 350-750 nm, and the ratio of absorbency between the root and the main peak is 2 or more.;COPYRIGHT: (C)1999,JPO