Rhone-poulenc Systemes

Rhone-poulenc Systems

Marta Szretter

Marcel Pigeon

Chantal Perie

A film-forming oleophilic photopolymerizable composition is formed from a fluid epoxy resin having an epoxy equivalent of less than 350 and a photosensitive condensation product of a paradiazodiphenylamine fluoroborate and an organic condensation agent. The photopolymerizable compositions can be used as the photosensitive layer of negative lithographic plates, such as printing plates. Acidic aqueous solvent-developable negative lithographic plates are also provided in which the photosensitive layer is formed from a layer of the film-forming oleophilic photopolymerizable composition which is deposited on a hydrophilic support from an organic solvent solution. The lithographic printing plates of the present invention have high mechanical resistance, long shelf-life and can be used in large production runs to make a great number of copies.

Oleophilic, film-forming photopolymerizable diazo and epoxy resin

Montage films, duplicating films, color guide films, microfiche film, color transparencies and similar visual aids are prepared from photosensitive articles having a layer of a photosensitive composition coated on a transparent support, preferably a flexible plastic transparent support. The exposed articles are developable with water to form the visual aid. The photosensitive layer is formed from a composition which includes a photosensitive reaction product of a condensation product of a diazonium compound with an arylsulfonic acid, and an epoxy resin which is liquid at ambient temperatures. The diazonium compound is preferably a paradiazodiphenylamine and the preferred condensing agent is formaldehyde or paraformaldehyde. The photosensitive layer can be colored with a permanent dye of a color depending on the type and use of the visual aid. Best results, with regard to water-developability and mechanical strength, are provided by first coating the transparent support with an intermediate layer of an adhesive resin.

Photosensitive article for making visual aids with diazonium compounds

A film-forming oleophilic photopolymerizable composition is formed from a fluid epoxy resin having an epoxy equivalent of less than 350 and a photosensitive reaction product of a water-soluble, photosensitive condensation product of a diazonium compound and an organic condensation agent with an organic coupling agent. The organic coupling agent is selected such that the photosensitive reaction product is soluble in organic solvents but only slightly soluble in water. The photopolymerizable compositions can be used as the photosensitive layer of water-developable negative lithographic plates, such as printing plates. Water-developable negative lighographic plates are also provided in which the photosensitive layer is formed from a layer of the film-forming oleophilic photopolymerizable composition which is deposited on a hydrophilic support from an organic solvent solution. In addition to being water-developable the negative lithographic printing plates of the present invention have high mechanical resistance, long shelf-life and can be used in large production runs to make a great number of copies.

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Neuilly, France

Marta Szretter