A method for making a lithographic printing plate by phototypie with the use of the silver salt diffusion transfer process -

摘要

The present invention provides a method for making a lithographic printing plate according to the silver salt diffusion transfer process comprising the following steps:image-wise exposing with a high intensity-short time exposure an imaging element comprising on a support a photosensitive layer comprising at least one photosensitive silver halide emulsion comprising a heterocyclic compound containing at least one nitrogen atom in the ring and an image receiving layer comprising physical development nuclei in water permeable relationship with said photosensitive layer,developing said imaging element using an alkaline processing liquid in the presence of (a) developing agent(s) and (a) silver halide solvent(s), characterized in that said heterocyclic compound containing at least one nitrogen atom in the ring comprises at least one mercapto- or thione group and one substituent comprising at least 5 carbon atoms selected from the group consisting of linear or branched alkyls, alkenyls, alkynyls, aralkyls and alkylaryls.