Eastman-kodak Company

John A Haefner

Herbert S Wilgus

John E Keevert

Anthony D Gingello

Jess B Hendricks, Iii

Woodrow G McDugle, Jr

Alfred P Marchetti

Cynthia G Jones

James T Kofron

Francis J Evans

Robert E Booms

The invention provides a process for incorporating iridium into silver chloride or silver chlorobromide emulsions containing 90% or more chloride which comprises addition of an iridium salt along with or followed by the addition of bromide to the emulsion, after completion of the precipitation stage of emulsion manufacture. The invention also encompasses the formed emulsions and photographic elements comprising the emulsions.

Iridium and bromide in silver halide grain finish

Photographic silver halide emulsions are disclosed comprised of radiation sensitive silver halide grains exhibiting a face centered cubic crystal lattice structure internally containing a nitrosyl or thionitrosyl coordination ligand and a transition metal chosen from groups 5 to 10 inclusive of the periodic table of elements.

Photographic emulsions containing internally modified silver halide

High aspect ratio chemically and spectrally sensitized tabular grain silver halide emulsions, photographic elements incorporating these emulsions, and processes for the use of the photographic elements are disclosed. In the tabular grain emulsions the silver halide grains having a thickness of less than 0.3 micron and a diameter of at least 0.6 micron have a high aspect ratio and account for at least 50 percent of the total projected area of the silver halide grains present.

Sensitized high aspect ratio silver halide emulsions and photographic

A tabular grain silver halide emulsion is disclosed comprised of a dispersing medium and silver bromoiodide grains. Tabular silver bromoiodide grains having a thickness less than 0.3 micron and a diameter of at least 0.6 micron have 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. The high aspect ratio silver bromoiodide grains are prepared by concurrently running silver, bromide, and iodide salts into a reaction vessel while controlling pBr. Prior to the concurrent addition of silver and iodide salts the reaction vessel is substantially free of iodide.

High aspect ratio silver bromoiodide emulsions and processes for their

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Rush, NY, United States of America

John A Haefner