Agfa Gevaert Nv

Agfa-gevaert

Alfons J Bertels

Rene M De Keyzer

Francis J Sels

Albert Lucien Poot

Antoine A De Jaeger

Luc Vanooteghem

An apparatus and a method for making a lithographic printing plate by silver salt diffusion transfer processing, comprising means for informationwise exposing an imaging element (5) comprising on a support in the order given a silver halide emulsion layer and a layer comprising physical development nuclei: means for processing a thus obtained informationwise exposed imaging element using a processor comprising a developing unit (120), the developing unit comprising (i) a tank holding an alkaline processing liquid, (ii) a plurality of guide rollers (50) and guide plates (121 to 126) for transporting and guiding the informationwise exposed imaging element in a transport direction X through the alkaline processing liquid characterised in that at least one of the guide plates (121 to 126) exhibits a plurality of apertures (150) to allow the alkaline processing fluid to pass evenly near the surface of the imaging element.

Apparatus and method for making a lithographic printing plate according

A method for the preparation of a planographic printing plate wherein a sheet material, which comprises an exterior hydrophilic colloid layer having concentrated on its surface a silver image formed by the silver complex diffusion transfer process with NiS or mixed crystal NiS.Ag.sub.2 S development nuclei in which the molar ratio of NiS to Ag.sub.2 S is not smaller than 1:1, is treated with a liquid for hydrophobizing the silver image for planographic printing, such liquid containing in dissolved state a heterocyclic compound corresponding to one of the following tautomeric structures (A) and (B) or (C) and (D): ##STR1## wherein: R.sup.1 represents hydrogen, amino or acylamino,

Method for the preparation of a planographic printing plate using NiS

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Olen, Belgium

Alfons J Bertels