Eastman-kodak Company

Sanford Howard Ehrlich

James L Edwards

Benjamin T Chen

Roger L Lok

Radiation sensitive emulsions are disclosed comprised of silver iodochloride grains having three pairs of equidistantly spaced parallel {100} crystal faces and containing from 0.05 to 3 mole percent iodide, based on total silver, in a controlled, non-uniform iodide distribution forming a core containing at least 50 percent of total silver, a surface shell, and a sub-surface shell that contains a maximum iodide concentration and provides, when the emulsion is exposed to 390 nm electromagnetic radiation at 10.degree. K., stimulated fluorescent emissions in the range of from 450 to 470 nm and at 500, the stimulated fluorescent emission in the range of from 450 to 470 nm having a peak intensity more than twice the stimulated fluorescent emission intensity at 500 nm. The emulsion is prepared by a process wherein a) grains accounting for at least 50 percent of total silver forming the silver iodochloride grains are grown in the dispersing medium, (b) while employing the grains as substrates for further grain growth, locating crystal lattice variances in the grains by the incorporation of iodide to form a first shell having a higher local iodide concentration than any other grain portion, and (c) precipitating silver chloride onto the surface of the grains formed in step (b) to create a surface shell separating the first shell from the surface of the completed grains.

Cubical grain silver iodochloride emulsions and processes for their

Photographic print elements are disclosed of enhanced speed and controlled minimum densities provided by emulsion layer units that contain emulsions that are blends of (a) cubical silver iodochloride grains that contain iodide in a controlled, non-uniform distribution forming a core containing at least half of total silver, a iodide-free surface shell having a thickness of greater than 25 .ANG., and a sub-surface shell that contains a maximum iodide concentration and (b) minimum density controlling silver halide grains that are of smaller mean grain size than the silver iodochloride grains and that consist essentially of chloride and/or bromide and are present in a molar concentration at least equal to that of silver iodide in the silver iodochloride grains.

Photographic print elements containing cubical grain silver iodochloride

A photographic print element is disclosed having a reflective support and at least one image recording emulsion layer unit containing cube-like silver iodochloride grains containing from 0.05 to 3 mole percent iodide, based on total silver, in a controlled, non-uniform iodide distribution forming a core, an iodide-free surface shell having a thickness of greater than 50 .ANG., and a sub-surface shell that contains a maximum iodide concentration.

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Pittsford, NY, United States of America

Sanford Howard Ehrlich