Imaging element and method for making lithographic printing plates according to the silver salt diffusion transfer process

A method for making a lithographic printing plate according to the silver salt diffusion transfer process comprising the steps of:

• (a) image-wise exposing an imaging element comprising on a flexible hydrophobic support in the order given (i) a subbing layer containing a hydrophilic binder and silica in an amount between 200 mg/m.sup.2 and 750 mg/m.sup.2, (ii) a hardened hydrophilic layer, contiguous to said subbing layer and containing a hydrophilic synthetic homopolymer or copolymer and being hardened with a hydrolyzed tetraalkyl orthosilicate crosslinking agent, (iii) a receiving layer containing physical development nuclei contiguous to said hydrophilic layer, (iv) an intermediate layer comprising a non-proteinic hydrophilic film-forming polymer or hydrophobic polymer beads having an average diameter not lower than 0.2 .mu.m and having been prepared by polymerization of an ethylenically unsaturated monomer and (v) a photosensitive layer containing a silver halide emulsion being in water permeable relationship with said receiving layer,
• (b) applying an aqueous alkaline solution to the imaging element in the presence of (a) developing agent(s) and (a) silver halide solvent(s) to form a silver image and to allow unreduced silver halide or complexes formed thereof to diffuse image-wise from the photosensitive layer to said receiving layer to produce therein a silver image, and
• (c) washing the imaging element to remove the photosensitive layer, thereby exposing said silver image formed in said receiving layer.