Eastman-kodak Company

Benjamin T Chen

James L Edwards

Roger L Lok

Richard L Parton

Eric L Bell

Sanford Howard Ehrlich

Roger L Klaus

Jerzy Z Mydlarz

Jerzy A Budz

Weimar W White

Jess B Hendricks, Iii

Michael G Antoniades

Donald Robert Irwin

Sucheta Tandon

Heinz E Stapelfeldt

Jeri L Mount

Katrin I Parsiegla

Douglas E Singer

Harold G Judd

A mixer for preparing silver halide grains for photographic use has upper and lower impellers housed in a draft tube. The bottom impeller has flat blades for micromixing silver and halide reactants introduced into the bottom of the draft tube. The upper impeller has pitched blades for macromixing the bulk fluid. The impellers are spaced apart at least the distance of their diameters so that the upper and lower impellers operate independently of one another so that micromixing is independent of macromixing. A flow disrupter structurally associated with the draft tube and positioned above the top impeller prevents vortexing of the fluid during mixing. Baffles may be provided in the draft tube to discourage vortexing.

Scalable impeller apparatus for preparing silver halide grains

Precipitation of high chloride content silver halide emulsions

The invention relates to a method of forming a silver halide emulsion comprising adding triiodide during grain formation or sensitization.

Preparation of silver chloride emulsions having iodide containing grains

A radiation sensitive emulsion is disclosed containing iridium doped composite silver halide grains comprised of (a) host portions having an average aspect ratio of less than 1.3 and consisting essentially of monodisperse silver iodochloride grains containing from 0.05 to 3 mole percent iodide, based on total silver forming the host portions, with maximum iodide concentrations located nearer the surface of the host portions than their center and (b) epitaxially deposited portions containing the iridium dopant and silver bromide accounting for from 0.1 to 5 mole percent of total silver forming the composite grains. The emulsions are prepared by (a) first providing an emulsion containing grains which form the host portions of the grains and (b) modifying the performance properties of the host grains by a combination of silver bromide addition, iridium dopant incorporation and antifoggant addition, in which, prior to antifoggant addition, silver bromide in the amount of from 0.1 to 5.0 mole percent, based on total silver, is added to the host grain emulsion and deposited onto the host grains in the presence of the iridium dopant to be incorporated. The emulsions of the invention demonstrate generally acceptable photographic characteristics, increased speed, and increases in contrast as exposure intensities are increased.

Composite silver halide grains and processes for their preparation

The invention relates to a photographic element for digital exposure comprising at least one layer comprising an emulsion of cubic silver iodochloride grain wherein said grain has been sensitized with a gold compound and with less than 1 .mu.mole per silver mole of sulfur.

Digital imaging with high chloride emulsions containing iodide

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.

The invention relates to a photographic element comprising a silver halide emulsion wherein at least one layer contains a silver chloroiodide emulsion containing at least 95 mole percent chloride and contains a sensitizing dye of the following general formula (I): ##STR1## wherein: Z1 represents a halogen, a cyano group, an amide substituted aromatic group, or a heteroaromatic group that is directly appended to the benzene ring shown or an aromatic group that is attached through an amide linking group and

Low staining green spectral sensitizing dyes and silver chloride

The invention provides a radiation sensitive emulsion comprised of a dispersing medium and silver iodochloride grains

Iodochloride emulsions containing iodonium salts having high sensitivity

The invention relates to a radiation sensitive emulsion comprised of a dispersing medium and silver iodochloride grains wherein the silver iodochloride grains

High chloride emulsions having high sensitivity and low fog and improved

The invention relates to a radiation sensitive emulsion comprised of a dispersing medium and silver iodochloride grains Wherein the silver iodochloride grains are partially bounded by {100} crystal faces satisfying the relative orientation and spacing of cubic grains and contain from 0.05 to 1 mole percent iodide, based on total silver, with maximum iodide concentrations located nearer the surface of the grains than their center and wherein said emulsion further comprises a quinone comprising ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, and R.sub.4 may be independently substituted or non-substituted alkyl, aryl, alkylaryl, or halogen, carboxy, amido, cyano, methoxy; together R.sub.1 and R.sub.2, R.sub.3 and R.sub.4 may form carbocyclic, heterocyclic, aromatic, or heteroaromatic rings.

Iodochloride emulsions containing quinones having high sensitivity and

The invention provides a cyan color producing silver halide emulsion layer or a magenta color producing silver halide emulsion layer wherein said at least one layer has an exposure range of at least 0.6 log E from the point where the instantaneous contrast is 1.0 and wherein the instantaneous contrast of said layer increases as a function of increasing exposure over at least 70 percent of said exposure range.

Silver halide color photography element with improved high density

Silver halide color photographic element with improved high density

This invention provides a process for preparing a bleach accelerator silver salt dispersion by precipitating a salt of a bleach accelerating compound and a silver salt wherein the vAg is maintained at a predetermined level during the precipitation. This invention further provides a photographic element containing a dispersion of grains of a bleach accelerator silver salt wherein the grains are isomorphic or derived from needle or platelet isomorphic crystals.

Growing community of inventors

Penfield, NY, United States of America

Benjamin T Chen