Dupont (UK) Limited

Vickers, Inc.

E.i. Dupont De Nemours and Company

Other

Agfa-Gevaert

Afga-Gevaert Nv

Du Pont-Howson Limited

John R Wade

Michael John Pratt

Rodney M Potts

Jianrong Ren

Robert A Johnstone

Allen P Gates

Andrew E Matthews

David E Murray

Christopher W Folkard

John Kynaston Davies

Maria De Lurdes Dos Santos Cristiano

William A King

Robert Alexander Walker Johnstone

Sharon Dowd

Terrence Etherington

Terence Etherington

Keith M Fletcher

Jeremy R Burch

David I Smith

Organic photoprecursors of amines are provided for use in photosensitive imaging systems, finding particular application in the preparation of lithographic printing plates. Said photoprecursors generate free amines on exposure to long wavelength UV or visible radiation, have high solubility in organic solvents, and include photolabile 2-nitrobenzyl functional groups. Methods for the synthesis of the photoprecursors are described, and the use of the said photoprecursors for the production of printing plates using both positive working and negative working techniques are discussed.

Photoactive materials applicable to imaging systems

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

Colorants, polymeric binder resins, photoinitiators, photosensitizers, color-change agents, anti-halation agents, stabilizers, and other active hydrogen-containing components of radiation sensitive compositions for lithographic printing plate production and the like are reacted with a polyethylenically unsaturated monoisocyanate compound of the formula ##STR1## wherein Y is the residue of a monohydroxyl compound of formula YOH and Y contains at least two ethylenically unsaturated double bonds. In this way the components are bonded to the image on exposure.

Photopolymerisable components of radiation sensitive compositions

Radiation-sensitive materials comprising a layer having core-shell

A radiation-sensitive plate comprises a substrate coated with a radiation-sensitive composition including a component having groups imparting solubility in aqueous solutions and a component having functional groups capable of reacting with a silane compound. The surface of the composition is modified by reaction with a silane compound. The plate gives rise to images of improved ink receptivity and can be developed in aqueous developer liquids after image-wise exposure.

Lithographic printing plates containing functional groups capable of

Polyunsaturated diazonium compounds suitable for use in negative working radiation sensitive compositions are provided. They may be produced by reacting an aromatic diazonium compound of the formula

Process for preparing a polyunsaturated diazonium compounds

A radiation-sensitive compound has the general formula ##STR1## wherein A represents the ring members required to complete a 5- or 6-membered heterocyclic ring which may optionally be fused to an optionally substituted aromatic nucleus,

Radiation sensitive compounds

Polyunsaturated diazonium compounds

A radiation sensitive plate comprises a substrate coated with a photopolymerisable composition. The composition comprises a polymerisable compound containing ethylenic unsaturation, a perester photoinitiator and optionally an optical sensitiser. The substrate may be a sheet of grained and anodised aluminum and the plate is useful in the production of lithographic printing plates.

Radiation sensitive plates

A polymeric compound is derived from a polyhydric material and has pendant sulphonate groups of the general formula ##STR1## where X is an aliphatic, aromatic, carbocylic or heterocyclic group; Y is hydrogen, halogen or an alkyl, aryl, alkoxy, aryloxy or aralkyl group, CO.sub. --Z.sup.+, CO.sub.2 R or SO.sub.3 -Z.sup.+ ; Z.sup.+ is a cationic counter ion and R is hydrogen, alkyl, alkylene, aryl or aralkyl group.

Polymeric compounds having pendant sulphonate groups for use in a

A radiation sensitive composition comprises a radiation sensitive material and a dye which dye undergoes a colour change in the radiation-struck areas on image-wise exposure of the composition and a colour change when the exposed and developed composition is heated to a temperature of at least 180.degree. C.

Radiation sensitive compositions

Radiation sensitive compound

A radiation sensitive composition comprises a radiation sensitive material and a dye which dye undergoes a color change in the radiation-struck areas on image-wise exposure of the composition and a color change when the exposed and developed composition is heated to a temperature of at least 180.degree. C.

A radiation sensitive plate comprises a substrate coated with a photopolymerizable composition. The composition comprises a polymerizable compound containing ethylenic unsaturation, a perester photoinitiator and optionally an optical sensitiser. The substrate may be a sheet of grained and anodized aluminum and the plate is useful in the production of lithographic printing plates.

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Otley, United Kingdom

John R Wade