Minnesota Mining and Manufacturing Company

Imation Corporation

Alberto Vacca

Angelo Vallarino

Mauro Besio

Aldo Sgarbi

Marino Rossi

Paolo Barletta

Infrared sensitive photographic elements comprise an opaque film support, an infrared sensitized silver halide emulsion layer and a hydrophilic colloid protective layer on one side of the film support, said protective layer comprising colloidal silica having an average particle size lower than 15 nanometers. The elements have an increased exposure latitude upon exposure to infrared laser diodes, and higher maximum density upon photographic processing.

Infrared sensitive photographic elements

A method is disclosed of preparing washed silver halide photographic emulsions wherein silver halide grain formation is effected in the presence of an acid-coagulable gelatin derivative or a mixture of gelatin and an acid-coagulable gelatin derivative and coagulation of the emulsion occurs in the presence of ionic copolymers of styrene sulfonic acid and maleic acid.

Method of preparing silver halide photographic emulsions

UV-sensitive negative acting silver halide photographic elements for contact processes which can be safely handled under white light and have increased UV exposure latitude, said elements comprising a support base, a hydrophilic colloidal silver halide emulsion layer comprising UV sensitive negative acting silver halide grains, and one or more hydrophilic colloidal layers, wherein said silver halide emulsion is reactively associated with a water-removable UV-absorbing compound having at least 80% of the absorption in the range from 350 to 400 micronmeter.

Negative-acting silver halide photographic elements having extended UV

An improved process for preparing silver halide emulsions by precipitation of silver halide grains in a single reaction vessel comprising a dispersing medium is disclosed. The process comprises forming a silver halide emulsion by adding silver salt and halide salt solutions in a dispersing medium contained in a reaction vessel to form silver halide nuclei and allowing said silver halide nuclei to grow in said reaction vessel. The improvement comprises, during a pause of addition of silver salt and halide salt solutions, reducing the volume of silver halide emulsion by continuously delivering the silver halide emulsion to a cleaning stage for the partial removal of dispersing medium and any salt soluble therein and returning the silver halide emulsion to the reaction vessel.

Process for the production of photosensitive silver halide emulsions

UV-sensitive direct positive silver halide photographic elements for duplicating processes which can be safely handled under white light, said elements comprising a support base, a hydrophilic colloidal silver halide emulsion layer comprising fogged silver halide grains, and one or more hydrophilic colloidal layers, wherein said silver halide emulsion is reactively associated with a water-removable UV-absorbing compound having at least 80% of the absorption in the range from 350 to 400 .mu.m.

White light handeable direct-positive silver halide photographic elements

A photosensitive silver halide material for obtaining black and white half-tone dot or line images comprises a fine grain and high-chloride silver halide emulsion reactively associated with an aqueous latex of a hydrophobic vinyl addition polymer in combination with a stabilizer selected from the group consisting of 4-hydroxy-1,3,3a,7-tetrazaindenes, benzotriazoles and benzimidazoles. The silver halide emulsion has an average grain size lower than or equal to 0.20 micron with at least 60% of its molar halide content consisting of chloride ions. The material allows high-contrast and high resolving power images to be obtained. The material has a good developability in photographic processings and this reduces the development times and increases productivity.

Growing community of inventors

Carcare, Italy

Alberto Vacca