Agfa-gevaert

Agfa Graphics Nv

Agfa Gevaert Nv

Agfa Healthcare

Agfa Geveart

Huub Van Aert

Marc Irene Van Damme

Joan T Vermeersch

Bert Groenendaal

Johan August Loccufier

Dirk Franky Kokkelenberg

Eric Verschueren

Frank Louwet

Ivan Hoogmartens

Frank G De Voeght

Peter Slabbinck

Carlo A Uyttendaele

Guido I Hauquier

Leo Oelbrandt

Luc H Leenders

Hieronymus Andriessen

Etienne A Van Thillo

Johan J Lamotte

Stefaan Lingier

Dirk Cyriel Quintens

Tom Cloots

Jan Gilleir

Joseph Vander Aa

Marc Van Damme

Peter Hendrikx

Leo Vermeulen

Govert De Baecke

Wim Sap

Frank Ruttens

Walther Wouters

Michel Boulonne

Martin Moeller

Diane Vertruyen

Christiaan Van Roost

Dirk Faes

Uwe Beginn

Ahmed Mourran

Jos Huybrechts

Helmut Ritter

Joachim Storsberg

Veerle Verschueren

Peter Hendri Kx

Sue Wilkinson

Horst Friedel

A method of making a lithographic printing plate includes the steps of:

Method of developing a heat-sensitive lithographic printing plate precursor with a gum solution

A polymer for a heat-sensitive lithographic printing plate precursor is disclosed wherein the polymer comprises a phenolic monomeric unit wherein the H atom of the hydroxy group of the phenyl group of the phenolic monomeric unit is replaced by a group comprising a N-imide group and wherein the substitution of the polymer increases the chemical resistance of the coating of the printing plate precursor.

Polymer for heat-sensitive lithographic printing plate precursor

A polymer for a heat-sensitive lithographic printing plate precursor is disclosed wherein the polymer comprises a phenolic monomeric unit of which the phenyl group is substituted by a group A characterised in that the group A comprises an imide or thioimide group and wherein the modification of the polymer increases the chemical resistance of the coating of the printing plate precursor.

A positive working heat-sensitive lithographic printing plate precursor is disclosed which comprises a support having a hydrophilic surface and a coating, provided on the hydrophilic surface, wherein the coating comprises a spacer particle comprising aluminum hydroxide or aluminum oxide and having an average particle size larger than 0.3 &#x3bc;m, for improving the scuff-mark resistance of the coating. Furthermore, the coating comprises an infrared light absorbing agent, an oleophilic resin soluble in an aqueous alkaline developer and a developer resistant means.

Positive working heat-sensitive lithographic printing plate precursor

A heat-sensitive lithographic printing plate precursor is disclosed which comprises a hydrophilic support and an oleophilic coating comprising an infrared absorbing agent and a developer soluble polymer which comprises a phenolic monomeric unit wherein the phenyl group of the phenolic monomeric unit is substituted by a group Q, wherein Q has the structure and is covalently linked to a carbon atom of the phenyl group and wherein L, Land Lare linking groups, a, b and c are 0 or 1, and T, Tand Tare terminal groups. The polymer, substituted by the group Q, increases the chemical resistance of the coating.

Heat-sensitive lithographic printing plate precursor

A substantially light-insensitive monosheet thermographic recording material comprising a support and on one side of the support a thermosensitive element, the thermosensitive element comprising at least one substantially light-insensitive silver salt of a carboxylic acid, at least one reducing agent therefor in thermal working relationship therewith and at least one binder, the at least one binder comprising at least one first polymer consisting of vinyl aceto-acetal monomer units and optionally monomer units selected from the group consisting of vinyl alcohol, vinyl acetate and itaconic acid monomer units, wherein the weight ratio of the at least one binder to the light-insensitive silver salt(s) of a carboxylic acid in the thermosensitive element is greater than 1.6; and the at least one binder optionally contains less than 40% by weight of a second polymer consisting of vinyl butyral monomer units and optionally vinyl alcohol and/or vinyl acetate monomer units.

Binders for use in the thermosensitive elements of substantially light-insensitive thermographic recording materials

A method for preparing a negative-working lithographic printing plate is provided which comprises the steps of (1) providing a lithographic printing plate precursor comprising on a grained and anodized aluminum support, having a hydrophilic surface, a coating comprising (i) polymer particles which are core-shell particles having a hydrophobic heat-softenable core and a hydrophilic shell and (ii) an infrared light absorbing agent, (2) exposing said coating to heat, thereby inducing coalescence of said polymer particles at exposed areas of said coating, and (iii) developing said precursor by applying a gum solution to said coating, thereby removing non-exposed areas of said coating from said support. According to the above method the printing plates exhibit after ageing an improved clean-out and a reduced background stain, resulting in toning-free printing.

Method of making a negative-working lithographic printing plate

A method of making a lithographic printing plate is disclosed which comprises the steps of

A heat sensitive lithographic printing plate precursor is disclosed comprising on a support having a hydrophilic surface or which is provided with a hydrophilic layer, a coating comprising an infrared light absorbing agent and a copolymer which comprises a plurality of recurring units X having a hydrophilic polymeric pendant group and a plurality of recurring units Y having a hydrophobic polymeric pendant group. Said coating is capable of switching from a hydrophilic state into a hydrophobic state after exposure to heat and/or infrared light.

According to the present invention there is provided a positive-working lithographic printing plate precursor which comprises on a support having a hydrophilic surface or which is provided with a hydrophilic layer, an oleophilic coating comprising an infrared absorbing agent, an alkali-soluble polymeric binder and a polysiloxane which comprises at least one carboxylic acid group or a salt thereof. The disclosed printing plate precursor has an improved sensitivity and at the same time a high under exposure latitude and a high developer resistance.

A heat-sensitive lithographic printing plate precursor is disclosed which comprises a hydrophilic support and an oleophilic coating thereon which comprises an infrared light-to-heat converter, an alkali-soluble binder and a polymeric developer accelerator. The polymeric developer accelerator is preferably a phenolic formaldehyde resin comprising at least 70 mol % of meta-cresol as recurring unit or at least 40 mol % of monohydroxy benzene cresol as recurring unit. The PDA may also be a phenolic resin which comprises at least 5 mol % of a recurring monomeric unit having at least one phenolic hydroxyl group and at least one alkali solubilising group. The polymeric developer accelerator improves the sensitivity while maintaining a good under-exposure latitude and a good developer resistance of the printing plate.

A heat-sensitive lithographic printing plate precursor is disclosed which comprises a hydrophilic support and an oleophilic coating comprising an infrared absorbing agent and a polymer, which comprises a phenolic monomeric unit wherein the phenyl group of the phenolic monomeric unit is substituted by a group having the structure &#x2014;N&#x2550;N-Q wherein the &#x2014;N&#x2550;N&#x2014; group is covalently bound to a carbon atom of the phenyl group and wherein Q is an aromatic group and wherein the substitution increases the chemical resistance of the coating.

A method for making a heat-sensitive negative-working lithographic printing plate precursor is disclosed comprising the steps of

Method for making a negative working, heat-sensitive lithographic printing plate precursor

A method has been disclosed of preparing ultrafine hydrophobic latex particles of polymers and copolymers by free radical emulsion polymerization in a water-based system, making use therefor, in order to polymerize or copolymerize monomers or monomer mixtures respectively, of at least one compound selected from the group consisting of dimers and cobalt complexes, acting as a chain transfer agent (CTA), wherein said latex particles have an average particle size of less than 100 nm, being more than 10% lower than if prepared in the absence of said CTA, characterized in that said polymerization is conducted in a water-based reaction in the presence of a chain transfer agent and of a surfactant, wherein said surfactant is present in a concentration versus said monomer or monomer mixture of from 5 up to 25% by weight for a non-ionic surfactant or from 0.05 up to 10% by weight for an ionic surfactant, more particularly a surfactant in a concentration below twice its critical micelle concentration.

Method of emulsion polymerization

A method for the preparation of a flexographic printing plate is disclosed. In this method an ink jet image is used as mask for the exposure of a flexo plate precursor. The ink jet recording material is composed of several layers and comprises a binder, a cationic mordant and a spacing agent in its top layer.

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Pulderbos, Belgium

Huub Van Aert