E.i. Dupont De Nemours and Company

Dupont (uk) Limited

Du Pont-howson Limited

Andrew E Matthews

Sheau-Hwa Ma

David E Murray

John R Wade

Michael John Pratt

Allen P Gates

William A King

Philip John Watkiss

John Michael Kitteridge

Peter Walker

A radiation sensitive material comprises particles including a water-insoluble heat-softenable core surrounded by a shell which is soluble or swellable in aqueous medium. The material also includes a radiation sensitive component which, on exposure to radiation, causes the solubility characteristics of the material to change. The material may be positive- or negative-working and may be coated onto a substrate from aqueous media to form a radiation sensitive plate which, after image-wise exposure, can be developed in aqueous media and then heated to cause the particles to coalesce and form a durable printing image.

Radiation-sensitive materials

A hydrophobic synthetic resin is used to partially or completely replace the hydrophilic colloid conventionally used in silver halide emulsions to obtain a radiation sensitive composition useful in the manufacture of radiation sensitive plates for use in printing plate production by image-wise exposure, tanning development, and washing. The synthetic resin includes a plurality of primary amino groups and optionally acidic groups and is soluble in aqueous or semi-aqueous alkaline solution.

Improvements in or relating to printing plates

Radiation-sensitive materials comprising a layer having core-shell

A method for preparing high resolution negative-working wash-off relief images comprising the sequential steps of: (a) providing a non-photosensitive, aqueous processable layer, preferably on a substrate, said layer comprising a dispersion of solvent-coalesceable particles in a polymer matrix; (b) imagewise applying an ink to the non-photosensitive layer to coalesce the particles and form a water-insoluble polymer blend between the particles and the polymer matrix in the ink applied areas; and (c) washing the layer with an aqueous developer solution to remove the non-ink applied areas of the layer.

Element containing latent image suited for aqueous wash-out development

Method for preparing negative-working wash-off relief images

A method for preparing high resolution wash-off images, preferably using ink jet printing, comprising the sequential steps of: (a) providing a non-photosensitive layer, preferably on a substrate, wherein the non-photosensitive layer comprises a polymer selected from the group consisting of acid containing polymers having at least 0.4 milliequivalents of acid functions per gram of polymer and amine containing polymers having at least 0.4 milliequivalents of amine functions per gram of polymer, (b) applying an aqueous ink imagewise to the non-photosensitive layer to form a salt of the polymer in the ink applied areas, said aqueous ink comprising an aqueous carrier medium and a salt-forming agent; and (c) washing the non-photosensitive layer with an aqueous solution to remove the imaged areas of the non-photosensitive layer.

Method for preparing high resolution wash-off images

A radiation sensitive device is provided with a discontinuous covering layer to improve vacuum draw down. The covering layer is produced by forming a solution or dispersion of the layer-forming material in a liquid hydrocarbon. Drops of the solution or dispersion are then sprayed onto the radiation sensitive device to form the discontinuous covering layer.

Radiation sensitive devices

Growing community of inventors

Leeds, United Kingdom

Andrew E Matthews