| 摘要 |
PROBLEM TO BE SOLVED: To obtain an image forming material having high density and high contrast and to obtain a lithographic printing plate with little printing contamination and excellent printing durability by using a nitrosyl metal or its sulfide or selenide. SOLUTION: As for the physical developing nuclei used for a silver complex salt diffusion transfer method, a nitrosyl metal or its sulfide or selenide is used. The metal used for the nitrosyl metal or its sulfide or selenide is preferably a metal element in the groups VII, VIII, IB, IIB, and for example, heavy metals such as silver, platinum, palladium, copper, cobalt, nickel and gold can be used. The nitrosyl groups may be used in a various range of proportion to the metal element, and is preferably in the range from 5×10-5 to 5 mol. Generally, after the obtd. lithographic printing plate is exposed for an image, it is subjected to the treatment with an alkali developer, and then if necessary, subjected to the plate making and printing treatment with a neutralizing liquid, fixing liquid, desensitizer, dampening liquid or the like. |
