Eastman-kodak Company

Roger H Piggin

Allison Hazel Dale

Julie Baker

Philip J Coldrick

Philip J Zola

Dawn J Jenkins

Herbert S Wilgus

Julia Pich

David Beaumond

Ming Jye Lin

Michael B Ledger

John C Solberg

Colin J Bishop

Richard A Hallett

Ian Barford

Mark L Magill

Paul R McIntyre

High contrast photographic element containing a novel combination of nucleators

A high contrast photographic material free from nucleating agents comprising a support bearing a silver halide emulsion layer comprising silver halide grains and a hydrophilic colloid having a silver:hydrophilic colloid ratio above 1.9, and containing a density enhancing amine compound in the emulsion layer or an adjacent hydrophilic colloid layer wherein at least 60% of the silver halide grains are spectrally sensitized. A photographic image can be formed from the imagewise exposed material by a method comprising developing the exposed material for a time no longer than 25 seconds at a temperature no greater than 35&deg; C.

Photographic high contrast silver halide material and method of processing

A high contrast photographic material comprises a support bearing a silver halide emulsion layer. This material is free from nucleating agents and has a silver:gelatin ratio greater than 1. The emulsion layer comprises silver halide grains that are spectrally sensitized. Moreover, the material contains a density enhancing amine compound in the emulsion layer or in an adjacent hydrophilic colloid layer. The spectrally sensitized silver halide grains comprise one grain population sensitized to radiation of a particular wavelength region, and one or more additional grain populations sensitized to radiation of a different wavelength region.

Photographic high contrast silver halide material

A density enhancing amine compound is incorporated into a silver halide element containing both spectrally sensitized and non-spectrally sensitized silver halide grains in the emulsion layer.

A high-contrast photographic material, adapted for use in the field of graphic arts, includes a hydrazide nucleating agent and comprises a silver halide emulsion layer containing silver halide grains which are spectrally sensitized with a non-desorbing sensitizing dye and silver halide grains which are not spectrally sensitized. Preferably, the photographic material also contains a booster compound which enables it to be processed in a developer having a pH of below 11.

High contrast photographic silver halide material

A high-contrast photographic element, adapted for use in the field of graphic arts, includes a hydrazide nucleator and an amine booster and comprises a silver halide emulsion layer which is capable of forming a latent image under conditions of use and a second silver halide emulsion layer which is not capable of forming a latent image under conditions of use.

A process is disclosed for the preparation of a tabular grain silver bromoiodide emulsion in which silver bromoiodide laminae are formed on the major faces of the tabular grains. The sensitivity of the emulsion as a function of pressure applied is rendered more nearly constant by forming the silver bromoiodide laminae on the major faces of the tabular grains within a pAg and temperature range defined by Curve A in FIG. 1. The laminae are formed by first precipitating iodide as a silver salt at peripheral sites on the tabular grains and then precipitating silver bromoiodide onto the major faces of the host tabular grains with the primary source of iodide being the previously deposited iodide. The emulsions produced exhibit high sensitivity to exposing radiation and reduced sensitivity to localized pressure.

Process of preparing a tabular grain silver bromoiodide emulsion

A process is disclosed for the preparation of a tabular grain silver bromoiodide emulsion in which silver bromoiodide laminae are formed on the major faces of the tabular grains. The sensitivity of the emulsion as a function of pressure applied is rendered more nearly constant by forming the silver bromoiodide laminae on the major faces of the tabular grains. The silver bromoiodide laminae are formed on the major faces of the tabular grains with an iodide content higher than that of the host emulsion, and thereafter, within the pAg and temperature boundaries defined by Curve A in FIG. 1, bromide is deposited as a silver salt with the addition of iodide being limited or absent.

Process of preparing a tabular grain silver bromoiodide emulsion and

Radiation-sensitive emulsions are disclosed comprised of a dispersing medium and silver bromoiodide grains. These emulsions contains tabular silver bromoiodide grains having a lower proportion of iodide in a central region than in a laterally displaced region, a thickness of less than 0.3 micron, and a diameter of at least 0.6 micron. These tubular grains exhibit an average aspect ratio of greater than 8:1 and account for at least 50 percent of the total projected area of the silver bromoiodide grains.

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Abbots Langley, United Kingdom

Roger H Piggin