Agfa-gevaert Ag

Agfa-gevaert

Afga-gevaert Nv

Klaus-Peter Konrad

Andreas Elsaesser

Hans-Joachim Schlosser

Willi-Kurt Gries

Werner Frass

Steffen Denzinger

Klaus-Juergen Przybilla

Otfried Gaschler

Thomas Leichsenring

Thorsten Lifka

Guenter Jung

John Kynaston Davies

Michael Doerr

Armin Pink

Frank Fischer

Paul Eckler

The invention relates to a pigment dispersion which contains at least one polymer containing polyvinyl alcohol, polyvinyl ether an/or polyvinyl acetal units and at least one polymer based on acrylate, wherein the weight ratio is generally 1:10 to 10:1, preferably 4:1 to 1:4. This dispersion is used in positive- or negative-working and reversible photosensitive mixtures for the preparation of recording materials.

Stable pigment dispersion and photosensitive recording material prepared therewith

The present invention relates to a recording material having a substrate and a negative-working, radiation-sensitive layer which contains a diazonium salt, metal-free colored pigments dispersed in an organic polymeric binder, transparent spacer pigments having a pore volume of more than 1.0 ml/g and a polymeric binder. The predispersal of the colored pigments is achieved by milling with an organic polymeric binder containing hydroxyl groups, some or all of which have been reacted with a di- or polycarboxylic anhydride so that the binder has an acid number of from 20 to 200. Printing plates in which the printing parts have a clearly visible contrast relative to the substrate can be produced from the recording material.

Recording material having a pigment-colored radiation-sensitive layer

The invention relates to a developer for irradiated, radiation-sensitive recording materials, in particular for the production of offset printing plates, which contains water, a compound which is alkaline in aqueous solution and a copolymer which acts as an emulsifier and has units of (I) a hydrophobic vinyl compound which has at least one optionally substituted mono- or bicyclic (C.sub.6 -C.sub.14)aryl radical and (II) a hydrophilic, ethylenically unsaturated carboxylic acid. Some of the carboxyl groups of the copolymer are esterified with reaction products of (A) (C.sub.1 -C.sub.30)alkanols, (C.sub.8 -C.sub.25)alkanoic acids, (C.sub.1 -C.sub.12)-alkylphenols or di(C.sub.1 -C.sub.20)alkylamines with (B) (C.sub.2 -C.sub.4)-alkylene oxides or tetrahydrofuran, the molar ratio (A):(B) being in the range from 1:2 to 1:50. If it is intended to develop recording materials having a negative-working layer, the developer additionally contains a water-miscible organic solvent and a surface-active compound. The developer has a low initial viscosity, which increases only slowly with increasing contamination with layer components. Furthermore it shows only a particularly low tendency to foam.

Developer for irradiated, radiation-sensitive recording materials

A photosensitive mixture which contains a polycondensation product of an aromatic diazonium salt, a water-soluble amphophilic polymeric binder having a mean molecular weight M.sub.w of 5000 to 100,000 and a nonionic surface-active compound having a molecular weight of 150 to 2000 is suitable for the production of printing plates, particularly offset printing plates, which can be developed with pure water and are notable for a rapid ink take-up and long print run.

Photosensitive mixture comprising a diazonium salt, an amphophilic

A radiation-sensitive recording material comprising: a base; a radiation-sensitive layer comprising a diazonium salt polycondensation product and 3 to 50% by weight, relative to the total weight of the radiation-sensitive layer, of a mineral acid; and a silicone layer.

Water developable diazonium and mineral acid containing recording

A photosensitive recording material is described which has a layer base, a negative-working photosensitive layer containing a diazonium salt and a water-insoluble polymeric binder which is soluble or swellable in aqueous alkaline solutions, and a discontinuous top layer which forms a rough surface and which is composed of particles of a water-insoluble polymer which is dispersible in water in the presence of anionic or anionic/nonionic dispersants and which has a content of free acid groups or acid groups neutralized by salt formation of less than 0.8 mmol/g, the mean height of the particles being 2 to 6 .mu.m, the maximum height less than 10 .mu.m, the mean horizontal diameter less than 40 .mu.m, the maximum diameter less than 80 .mu.m and the number of particles being 100 to 10,000 per cm.sup.2. The material is suitable for the production of planographic printing plates and requires only short vacuum times in a vacuum-operated copying frame. The material can be developed without residue after exposure, the rough surface remaining intact at the image areas.

Photosensitive recording material containing negative working diazonium

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Gensingen, Germany

Klaus-Peter Konrad