Agfa Gevaert Nv

Agfa-gevaert

Agfa Graphics Nv

Ludovicus H Vervloet

Paul J Coppens

Leon L Vermeulen

Willy P De Smedt

Eric M Hoes

Luc H Leenders

Piet Kok

Ronald Schuerwegen

Augustin Meisters

Joan T Vermeersch

Serge M Tavernier

Paul R Callant

Eddie R Daems

Jean-Pierre D Tahon

Guido I Hauquier

Ludo Van Rompuy

Willem Cortens

Robert S Pauwels

Theofiel H Ghys

Paul F Sterckx

Jan Sinnesael

Brigitte Parmentier

A method of making a lithographic printing plate including the steps of a) image-wise exposing a lithographic printing plate precursor including a light or heat sensitive coating on a support having a hydrophilic surface or which is provided with a hydrophilic layer, and b) processing the precursor consecutively with a first solution and a second solution thereby removing the coating from the support in the non-printing areas. The first and second solutions are provided by a cascade system such that the second solution overflows into the first solution and the first solution overflows into a container to be further treated as waste, and the second solution is regenerated by adding a replenishing solution or a mixture of replenishing solutions at a rate of at least 5 ml/mof treated precursor and at most 30 ml/mof treated precursor.

Method of making a lithographic printing plate

The present invention provides a method for making an offset printing plate according to the silver salt diffusion transfer process comprising the steps of: (a) image-wise exposing an imaging element comprising (i) a hydrophilic base, (ii) an image receiving layer containing physical development nuclei, (iii) an intermediate layer, and (iv) a silver halide emulsion layer,

Method for making lithographic printing plates according to the silver

The present invention provides a method for making an offset printing plate according to the silver salt diffusion transfer process comprising the steps of: image-wise exposing an imaging element comprising in the order given on a hydrophilic surface of a support (i) an image receiving layer containing physical development nuclei and (ii) a photosensitive layer comprising a photosensitive silver halide emulsion said photosensitive layer being in water permeable relationship with said image receiving layer, 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 in said image receiving layer, treating the imaging element to remove the layer(s) on top of the image receiving layer, thereby exposing the imaged surface of the support by uncovering said silver image formed in said image receiving layer, characterized in that said aqueous alkaline solution comprises less than 0.0021 mole/l of inorganic bromide salts and thiosulphate salts in a range from 0.005 mole/l to 0.025 mole/l.

Method for making an offset printing plate according to the silver salt

The present invention provides a method for making an offset printing plate according to the silver salt diffusion transfer process comprising the steps of exposing and developing an imaging element comprising in the order given on a hydrophilic surface of a support (i) an image receiving layer and (ii) a photosensitive layer comprising a photosensitive silver halide emulsion, removing the layer(s) on top of the image receiving layer thereby exposing the imaged surface of the support and treating said exposed imaged surface of the support with a finisher having a temperature between 30.degree. C. and 60.degree. C.

Finisher at 30.degree.-60.degree. C. in method for making an offset

The present invention provides a finisher comprising (a) hydrophobizing agent(s) in a total concentration between 0.1 g/l and 10 g/l, (a) surface-active compound(s) and (a) polyglycol(s), characterized in that said polyglycol(s) comprise(s) at least 50% by weight ethyleneoxide groups and/or propyleneoxide groups whose total sum is at least 7 and is (are) present in said finisher in a total amount of at least 10 g/l and there is further provided a method for making an offset printing plate according to the silver salt diffusion transfer process therewith.

The present invention provides an imaging element comprising in the order given (i) a hydrophilic base, (ii) an image receiving layer containing physical development nuclei and (iii) a photosensitive layer containing a silver halide emulsion being in water permeable relationship with said image receiving layer, characterized in that said photosensitive layer or another optional layer being in water permeable relationship therewith contains at least one gelatin species whereof a 10% by weight aqueous solution at 36.degree. C. and pH 6 has a viscosity lower than 20 mPa.s at a shearing rate of 1000 s.sup.-1.

Imaging element and method for making lithographic printing plate

The present invention provides an imaging element comprising on a flexible hydrophobic support (i) a hardened hydrophilic layer, containing a hydrophilic synthetic homocopolymer or copolymer and being hardened with a hydrolyzed tetraalkyl orthosilicate crosslinking agent, (ii) a receiving layer containing physical development nuclei contiguous to said hydrophilic layer, (iii) 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 a ethylenically unsaturated monomer and (iv) a photosensitive layer containing a silver halide emulsion being in water permeable relationship with said receiving layer. The invention also relates to a method for making lithographic plates with said imaging element.

Imaging element and method for making lithographic printing plates

The present invention provides a method for making an offset printing plate according to the silver salt diffusion transfer process having improved printing properties comprising the step of developing an imaging element comprising in the order given (i) a hydrophilic base, (ii) an image receiving layer containing physical development nuclei and (iii) a photosensitive layer containing a silver halide emulsion in the presence of a 1-phenyl-5-mercapto-tetrazole, being substituted by one or two substituents from the group consisting of:

The present invention provides a method for making an offset printing plate according to the silver salt diffusion transfer process using rinsing water, characterized in that alkali is added to said rinsing water before washing at most 20 m.sup.2 of said exposed and developed imaging element and/or before being in use for more than 24 hours in such an amount that a pH in said washing water between 10.5 and 13 is obtained.

Method for making a lithographic offset plate by the silver salt

The present invention provides a method for making an offset printing plate according to the silver salt diffusion transfer process using rinsing water, characterized in that said rinsing water before washing at most 20 m.sup.2 of said exposed and developed imaging element and/or before being in use for more than 24 hours is brought in contact with (i) a metal of the group IB or IIB or VIII of the periodic table or (ii) with an alloy containing at least one of said metals or (iii) with a salt containing an ion of at least one of said metals.

Method for making lithographic aluminum offset printing plates according to the DTR-process by photo-exposing a photosensitive monosheet layer assemblage comprising a hydrophilic aluminum foil, an intermediate layer comprising hydrophobic polymer beads prepared by polymerization of ethylenically unsaturated monomer(s) and having an average diameter not lower than 0.2 .mu.m, and a silver halide emulsion layer, applying an aqueous alkaline solution to the photo-exposed silver halide emulsion layer in the presence of a developing agent and a silver halide solvent to form a silver image and to allow unreduced silver halide or complexes formed thereof to diffuse imagewise from the developed silver halide emulsion layer to said aluminum foil to produce thereon a silver image, and separating said emulsion layer and said intermediate layer from the imaged aluminum foil. The invention also relates to the photosensitive monosheet layer assemblage used for making such printing plates.

Method of making lithographic aluminum offset printing plates

Method for making lithographic aluminium offset printing plates according to the DTR-process by photo-exposing a photosensitive monosheet layer assemblage comprising a hydrophilic aluminium foil, a water-swellable intermediate layer comprising a non-proteinic hydrophilic film-forming polymer, and a silver halide emulsion layer, applying an aqueous alkaline solution thereto in the presence of a developing agent and a silver halide solvent, allowing to reduce the photo-exposed silver halide, allowing the unreduced silver halide or complexes thereof to diffuse to said aluminium foil to form a silver image thereon, and separating said emulsion layer and said intermediate layer from the imaged aluminium foil. The invention also relates to the photosensitive monosheet layer assemblage used for making such printing plates.

Lithographic aluminum offset printing plate made according to the

The present disclosure relates to an electrophotographic method of obtaining a lithographic printing plate comprising the step of transferring a toner image from a toner image bearing member to a toner receiving plate, said toner receiving plate comprising a thermoplastic film support and a crosslinked hydrophilic layer thereon, characterized in that said crosslinked hydrophilic layer either carries on top thereof or incorporates spacing particles forming protuberances on said layer. According to a preferred embodiment, the average particle diameter by volume of the spacing particles is at least twice the average particle diameter by volume of the electrophotographic toner.

Method for obtaining litographic printing plates by electrophotographic

Method for making lithographic aluminium offset printing plates according to the DTR-process by photo-exposing a photosensitive monosheet layer assemblage comprising a hydrophilic aluminium foil, a water-swellable intermediate layer comprising a non-protenic hydrophilic film-forming polymer, and a silver halide emulsion layer, applying an aqueous alkaline solution thereto in the presence of a developing agent and a silver halide solvent, allowing to reduce the photo-exposed silver halide, allowing the unreduced silver halide or complexes thereof to diffuse to said aluminium foil to form a silver image thereon, and separating said emulsion layer and said intermediate layer from the image aluminium foil. The invention also relates to the photosensitive monosheet layer assemblage used for making such printing plates.

An image receiving material suitable for image production by dye diffusion transfer processing controlled by the development of (an) image-wise exposed silver halide emulsion layer(s), wherein said image receiving material comprises a supported image receiving layer free from gelatin and containing (1) a cationic polymeric mordant, and (2) colloidal silica applied from an aqueous acidic colloidal sol having a pH of not more than 4, and containing hydrated silica in combination with a smaller amount of colloidal alumina, the amount of said colloidal material to said mordant in the image-receiving layer being in a weight ratio range from 1/5 to 1/2, and silica (SiO.sub.2) being present at a coverage of at least 0.5 g per m2.

Growing community of inventors

Kessel, Belgium

Ludovicus H Vervloet