Eastman-kodak Company

Other

Donald L Black

Robert D Wilson

Xin Wen

Joseph C Deaton

Myra T Olm

Richard L Daubendiek

Timothy R Gersey

Joseph G Lighthouse

Mark Edward Irving

Thomas B Brust

David Howard Levy

Mark R Mis

Paul B Gilman, Jr

Michael R Roberts

David E Fenton

Kurt Michael Schroeder

Allen K Tsaur

Gary L House

Debra L Hartsell

Lucius S Fox

Stephen Swingley

Richard P Szajewski

Roger L Lok

Jerzy A Budz

Yun C Chang

Anne E Bohan

Tommie L Royster, Jr

James P Merrill

David Wallace Sandford

John E Keevert

Roger A Bryant

Mamie Kam-Ng

Sharon G Johnston

Michael G Antoniades

Sherrill A Puckett

JoAnn D Hanna

Philip J Dale

Eleanor Chaffee

Stephen C Stoker

Bernard D Stich

The present invention is directed to a method of forming a positive image in a photothermographic element comprising a potentially negative-working emulsion wherein fog density development is imagewise inhibited in exposed areas of the image upon thermal development, the element further comprising a developer or precursor thereof and an oxidized developer scavenging agent to accelerate development by removing oxidized developer as it is formed during the thermal development step. In one embodiment of the invention, in which a density-inhibiting agent is released during thermal development that inhibits the thermal development of unexposed silver salts in the exposed areas relative to the unexposed areas, the method comprises imagewise exposing the film with a non-solarizing amount of radiation/energy to form a latent image and thermally developing the latent image in a single development step to produce a positive image in the element. The present invention is also directed to a photothermographic element that can be used in the present process in which a positive image characterized by high speed and discrimination is formed when exposed and thermally heated above 150&#xb0; C.

High-speed positive-working photothermographic system comprising an accelerating agent

The present invention is directed to a method of forming a positive image in a photothermographic element comprising a potentially negative-working emulsion wherein fog density development is imagewise inhibited in exposed areas of the image upon thermal development. In one embodiment of the invention, a density-inhibiting agent is released during thermal development which agent inhibits the thermal development of unexposed silver salts in the exposed areas relative to the unexposed areas. The method preferably comprises imagewise exposing the film with a non-solarizing amount of radiation/energy to form a latent image and thermally developing the latent image in a single development step to produce a positive image in the element. The present invention is also directed to a photothermographic element that can be used in the present process in which a positive image characterized by high speed and discrimination is formed when exposed and thermally heated above 150&#xb0; C.

High-speed positive-working photothermographic system

The present invention is directed to a method of forming a positive image in a photothermographic film exposed by electrons in a transmission electron microscope to form a latent image in the film. The photothermographic film has at least one imaging layer comprising a potentially negative-working emulsion, but wherein thermal development of unexposed silver salts in exposed areas relative to unexposed areas is inhibited when thermally developing the imagewise exposed assembly, thereby producing a positive image. The present invention is also directed to the processing of the photothermographic film in which a positive image characterized by high speed and discrimination is formed in the film when heated above 150&#xb0; C.

Method of photothermographic imaging for transmission electron microscopy

A photographic element which comprises a support bearing: (i) a first radiation-sensitive silver halide emulsion image-forming layer comprising a high bromide tabular grain emulsion including tabular grains having &lcub;111&rcub; major faces, exhibiting an average thickness of at least 0.07 &mgr;m and an average aspect ratio of at least 2; and (ii) a second radiation-sensitive silver halide emulsion image-forming layer comprising an ultrathin tabular grain emulsion including tabular grains having &lcub;111&rcub; major faces, containing greater than 70 mole percent bromide and at least 0.25 mole percent iodide, exhibiting an average thickness of less than 0.07 &mgr;m and an average equivalent circular diameter of at least 0.7 &mgr;m, and having latent image forming chemical sensitization sites on the surfaces of the tabular grains; wherein the surface chemical sensitization sites include epitaxially deposited silver halide protrusions containing an actual chloride concentration of from 20-50 mole %, based on epitaxially deposited silver, the chloride concentration being at least 10 mole percent higher than that of the tabular grains, and containing an actual iodide concentration of from 1 to 7 mole %, based on epitaxially deposited silver.

Ultrathin tabular grain silver halide emulsion with improved performance in multilayer photographic element

The present invention is directed to a photothermographic element comprising silver halide, a blocked developer, a coupler, and core/shell particles, each such particle comprising a mixture of at least two non-photosensitive organic silver salts, which particle comprises a center portion comprising a non-photosensitive first organic silver salt and at least one shell portion covering the center portion, the shell comprising a non-photosensitive second organic silver salt. The organic silver salt in the shell has a lower pKsp relative to the organic silver salt in the core. This invention also provides a composition comprising the core/shell non-photosensitive organic silver salt particles, and a method of making the particles.

Core/shell silver donors for photothermographic systems comprising an oxidatively more reactive shell

The present invention is directed to a photothermographic element comprising silver halide, a blocked developer, a coupler, and core/shell particles, each such particle comprising a mixture of at least two non-photosensitive organic silver salts, which particle comprises a center portion comprising a non-photosensitive first organic silver salt and at least one shell portion covering the center portion, the shell comprising a non-photosensitive second organic silver salt. The organic silver salt in the shell has a higher pKsp relative to the organic silver salt in the core. This invention also provides a composition comprising core/shell non-photosensitive organic silver salt particles, and a method of making the particles.

Core/shell silver donors for photothermographic systems comprising an oxidatively less reactive shell

A process is disclosed of conducting in a single reaction vessel selective site high chloride epitaxy deposition as a continuation of host high bromide {1111} tabular grain emulsion precipitation. A host tabular grain emulsion is precipitated accounting for 0.05 to 1.5 moles of silver per liter of dispersing medium. Any iodide at the major faces of the tabular grains is uniformly distributed and any iodide in a surface region of the grains amounts to less than 7 mole, based on silver in the surface region. Until epitaxy is formed, pH is held in the range of 3 to 8. Gelatino-peptizer in an amount of 1 to 40 grams per Ag mole is added to the emulsion. Chloride ion in a range of from 0.03 to 0.15 mole per liter is dispersed in the emulsion. pBr is held in the range of from 3.0 to 3.8 until epitaxy is formed. Iodide ion in a concentration of from 5.times.10.sup.-6 to 1.times.10.sup.-4 mole per square meter of grain surface area is uniformly adsorbed to the major surfaces of the tabular grains.

Process of conducting epitaxial deposition as a continuation of emulsion

A process of preparing a radiation-sensitive silver halide emulsion is disclosed in which the silver halide grains form dispersed clumps. A population of fine silver halide grains is precipitated at higher concentrations than previously taught for preparing this type of an emulsion by employing a peptizer limited in amount, limited in methionine content, or both. Following formation of the grains, they are aggregated into clumps by the addition of a surfactant, optionally assisted by the adding iodide, increasing pH or both. The grain clumps are stabilized against further aggregation by adding a high methionine peptizer and optionally assisted by the precipitation of additional silver halide.

Process for the preparation of silver halide emulsions containing

Radiation-sensitive emulsions are disclosed comprised of high bromide tabular grains containing a peripheral band of increased iodide concentration. The tabular grains exhibit an average equivalent circular diameter of at least 2.0 .mu.m and are of a face centered cubic crystal lattice structure of the rock salt type. The tabular grains include central and peripheral regions extending between their major faces. The peripheral region is up to 0.2 .mu.m in width and contains an iodide concentration at least 2 mole percent higher than that of the central region measured at a location adjacent the peripheral region. Dislocations are present in the peripheral region to increase sensitivity and are minimized in the central region to maintain relatively constant sensitivities when pressure is applied locally.

Tabular grain emulsions exhibiting relatively constant high sensitivities

A photographic emulsion is disclosed in which radiation-sensitive silver halide grains are present containing (a) a continuous silver halide phase of a face centered cubic rock salt crystal lattice structure and (b) a discontinuous phase in the form of discrete islands separated by and surrounded by the continuous phase, each of the islands exhibiting a silver iodide crystal lattice structure.

Radiation-sensitive silver halide grains internally containing a

The invention relates to an emulsion comprising silver halide grains, said grains being tabular and comprising sensitizing dye(s) and silver salt epitaxial deposits, and addenda that include a mercaptotetrazole and a tetraazaindene.

Epitaxially sensitized ultrathin tabular grain emulsions containing

An emulsion of enhanced photographic sensitivity and reduced contrast is disclosed containing high bromide tabular grains having a non-uniform iodide distribution, including (a) a peripheral zone extending inwardly from edges and corners of the tabular grains and providing (i) a maximum iodide concentration along the edges and (ii) a lower iodide concentration at the corners than elsewhere along the edges, (b) a central zone providing a minimum iodide concentration and accounting for at least 35 percent of total silver forming the tabular grains and, (c) extending from the central zone to the peripheral zone, an intermediate zone (i) containing a higher iodide concentration than the central zone, ranging from greater than 2 to 10 mole percent, based on silver forming the intermediate zone, and (ii) accounting for from 5 to 35 percent of total silver forming the tabular grains.

Photographic emulsions of enhanced sensitivity and reduced contrast

An improved spectrally sensitized ultrathin tabular grain emulsion is disclosed in which tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, (e) exhibiting an average thickness of less than 0.07 .mu.m, and (f) having latent image forming chemical sensitization sites on the surfaces of the tabular grains, are spectrally sensitized and improved by employing dump iodide host tabular grains and, in forming the surface chemical sensitization sites, at least one silver salt epitaxially located on the tabular grains. A photographic element is disclosed comprised of a support, a first silver halide emulsion layer coated on the support and sensitized to produce a photographic record when exposed to specular light within the minus blue visible wavelength region of from 500 to 700 nm, a second silver halide emulsion layer capable of producing a second photographic record coated over the first silver halide emulsion layer to receive specular minus blue light intended for the exposure of the first silver halide emulsion layer, the second silver halide emulsion layer being capable of acting as a transmission medium for the delivery of at least a portion of the minus blue light intended for the exposure of the first silver halide emulsion layer in the form of specular light, wherein the second silver halide emulsion layer is comprised of the improved spectrally sensitized ultrathin tabular grain emulsion of the invention. The ultrathin dump iodide tabular grain emulsions with silver salt epitaxy chemical sensitization have been observed to produce larger than expected speed increases, to produce higher than expected contrasts, to be unexpectedly specularly transmissive and therefore compatible with forming sharp photographic images in underlying emulsion layers, to exhibit a higher percentage of total light absorption in the wavelength region of maximum absorption by the spectral sensitizing dye or dyes employed, and to exhibit a surprising tolerance of inadvertent manufacturing variances.

Epitaxially sensitized ultrathin dump iodide tabular grain emulsions

The invention provides a radiation-sensitive silver halide emulsion comprising

Epitaxially sensitized tabular grain emulsions containing speed/fog

A chemically and spectrally sensitized ultrathin tabular grain emulsion is disclosed including tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (e) exhibiting an average thickness of less than 0.07 .mu.m. It has been observed that increased speed and contrast as well as improvements in speed-granularity relationships can be realized when the surface chemical sensitization sites include epitaxially deposited silver halide protrusions forming epitaxial junctions with the tabular grains, the protrusions (a) being located on up to 50 percent of the surface area of the tabular grains, (b) having a higher overall solubility than at least that portion of the tabular grains forming epitaxial junctions with the protrusions, and (c) forming a face centered cubic crystal lattice. In further improving photographic performance by incorporating a photographically useful dopants, it has been observed that iridium placed in the ultrathin tabular grains and a shallow electron trapping site providing dopant placed in the silver halide protrusions can together increase photographic speed and reduce high intensity reciprocity failure.

Growing community of inventors

Webster, NY, United States of America

Donald L Black