Eastman-kodak Company

Joe E Maskasky

Victor P Scaccia

David A Dickinson

Kenneth Joseph Reed

Samuel Chen

James A Friday

Yun C Chang

Charles E Romano, Jr

Mark Lelental

Thomas W Martin

Martin McMillan

Carlos A Reyes

Thomas N Blanton

Roger L Klaus

Peter John Ghyzel

John W Boettcher

Lillian M Kellogg

James L Wakley

Dale E Hamilton

David Erdtmann

John E Keevert

Ralph W Jones, Jr

Michael G Antoniades

Scott A King

Philip I Rose

Richard L Gaines

Black-and-white direct thermographic materials and photothermographic materials can be processed or developed at lower temperatures because of the incorporation of a quaternary ammonium salt in an amount of at least 0.5 mol % based on total silver in the material.

Thermally developable materials processable at lower temperatures

Silver-free, aqueous-based direct thermographic materials are designed to have image tone with near neutral density. Without the use of organic silver salts containing reducible silver ions, the image is formed using a color developing agent precursor that releases a color developing agent when heated to a temperature of at least 80&#xb0; C., a combination of cyan, yellow and magenta dye-forming color couplers that provide cyan, yellow, and magenta dyes, and a substituted or unsubstituted benzoquinone as an oxidizing agent. No silver metal or silver ions are purposely added to these materials. This combination of components provides a means for controlling image tone without reliance upon conventional toning agents.

Silver-free black-and-white thermographic materials containing a benzoquinone and methods of imaging

Silver-free, aqueous-based direct thermographic materials are designed to have image tone with near neutral density. Without the use of organic silver salts containing reducible silver ions, the image is formed using a color developing agent precursor that releases a color developing agent when heated to a temperature of at least 80&#xb0; C., a combination of cyan, yellow and magenta dye-forming color couplers that provide cyan, yellow, and magenta dyes, and a hindered-amine N-oxyl as an oxidizing agent. No silver metal or silver ions are purposely added to these materials. This combination of components provides a means for controlling image tone without reliance upon conventional toning agents.

Silver-free black-and-white thermographic materials

Aqueous-based thermally sensitive emulsions and photothermographic imaging materials include photosensitive silver halide grains that comprise at least 15 mol % iodide based on total silver in the grains and are doped with bismuth (+3). These materials have increased photographic speed especially in the infrared region of the electromagnetic spectrum.

Photothermographic materials containing doped high iodide emulsions

The present disclosure relates to aqueous dispersions of silver (carboxylate-azine toner) particles wherein the azine content of the particles is from about 0.01 to 10% by weight relative to silver carboxylate. The carboxylates are typically silver salts of long chain fatty acids and the azine toners are the compounds that function as development accelerators and toning agents such as phthalazine. These silver (carboxylate-azine) particles can be used to formulate imaging forming compositions that are useful in aqueous thermographic or photothermographic imaging elements.

Silver-(carboxylate-azine toner) particles for photothermographic and thermographic imaging

A method of electronic processing of an imagewise exposed dispersed particle photoconductive material imaging element employing pulsed radiation and radio frequency photoconductivity apparatus having a sample capacitor with a gap is described, comprising the steps of: a) placing the imagewise exposed photoconductive material imaging element in an electromagnetic field adjacent the sample capacitor; b) scanning the element through the gap in the sample capacitor with a pulsed, focused beam of radiation; c) directly measuring the photoelectron response of the element and recording the resulting signals from the radio frequency photoconductivity apparatus; and d) advancing the element past the capacitor and repeating steps b) and c); wherein the photoconductive material imaging element comprises photoconductive particles which contain deep electron trapping agents which in an unfilled state effectively decrease the photoconductivity of the photoconductor particles, and wherein imagewise exposure of the photoconductive particles of the imaging element fill deep electron traps and increase the photoconductivity of exposed particles relative to unexposed particles, such that increased imagewise exposure in the photoconductive material results in an increased photoconductivity signal in step c).

Method of electronic processing of imagewise exposed photoconductive material imaging element

Aqueous-based thermally developable emulsions and photothermographic imaging materials include photosensitive silver halide core-shell grains that comprise at least 20 mol % iodide based on total silver, an amount of iodide in the core of the grains that can be up to the iodide saturation limit in silver iodobromide, and an amount of iodide in the shell of the grains that is at least 2 mol % less than the amount of iodide present in the core, and further provided that the total amount of silver in the shell is from about 10 to about 80 mol % of total silver in the grains. These materials provide desired D and reduced image &ldquo;print out&rdquo;.

Photothermographic materials containing high iodide core-shell emulsions

A photoconductive material imaging element is described comprising a support and a silver halide emulsion imaging layer comprising silver halide grains which have not been chemically sensitized to optimize formation of latent image Ag , centers upon imagewise exposure and which are doped with at least 500 deep electron trapping agent dopant centers per grain. In accordance with a preferred embodiment, the photoconductive material imaging element includes a planar support and the non-chemically sensitized, deep electron trapping agent doped silver halide grains comprise tabular grains, preferably with an average grain size equivalent circular diameter of greater than 2 &mgr;m, with the long dimensions of the tabular grains primarily oriented parallel to the plane of the support.

Photoconductive material imaging element

Silver-(carboxylate-azine toner) particles for photothemographic and thermographic imaging

Aqueous-based thermally sensitive emulsions and photothermographic imaging materials include phthalazine N-oxide or a derivative thereof to improve raw stock keeping and to extend the useful range of processing temperatures without interfering with spectral sensitization. The emulsions and photothermographic materials may also include a cyclic imide, phthalazinone, benzoxazine dione, benzthiazine dione, or quinazoline dione as a development promoter.

Thermally sensitive imaging materials containing phthalazine precursor

A process for precipitating a high bromide silver halide emulsion in an aqueous medium is disclosed comprising growing nucleated silver halide grains in a reaction vessel in the presence of a peptizer comprising a water dispersable starch to form high bromide radiation-sensitive silver halide grains, wherein the majority of grain growth in the reaction vessel is performed at a pH of less than 3.5. Growth of high bromide silver halide emulsion grains in the presence of a starch peptizer at low pH in accordance with the invention results in emulsion grains with lower fog, even in the absence of the use of strong oxidizing agents during grain precipitation.

Preparation of high bromide photographic emulsions with starch peptizer

A process for precipitating a high bromide silver halide emulsion in an aqueous medium is described comprising precipitating high bromide radiation-sensitive silver halide grains in a reaction vessel in the presence of a peptizer comprising a water dispersable starch, wherein a strong oxidizing agent is added to the reaction vessel during or after the precipitation at a pH of less than 4.0 such that an oxidation potential of at least 650 mV (Ag/AgCl ref.) is achieved. A reduction in the rate of reaction between strong oxidants such as bromine and starch at such low pH has been found to enable an advantageous decrease in the amount of oxidant required to achieve and maintain a high oxidation potential during emulsion grain precipitation. Starch, unlike gelatin, also advantageously has adequate stability at the combination of high acidity and high emulsion precipitation temperatures.

Preparation of high bromide photographic emulsions with starch peptizer and oxidizing agent

A process for precipitating a high chloride silver halide emulsion in an aqueous medium is disclosed comprising growing nucleated silver halide grains in a reaction vessel in the presence of a peptizer comprising a water dispersable starch to form high chloride radiation-sensitive silver halide grains, wherein the majority of grain growth in the reaction vessel is performed at a pH of less than 3.5. Growth of high chloride silver halide emulsion grains in the presence of a starch peptizer at low pH in accordance with the invention results in emulsion grains with lower fog, even in the absence of the use of strong oxidizing agents and antifoggants during grain precipitation.

Preparation of high chloride photographic emulsions with starch peptizer

There is disclosed an aqueous photothermographic composition comprising a) a photosensitive silver halide emulsion precipitated in a water dispersible cationic starch peptizing agent and b) an oxidation-reduction imaging forming composition comprising (I) a colloidal dispersion of silver compound particles and (ii) an organic reducing agent. The use of a starch peptizing agent reduces the fog in an element using the composition upon thermal processing.

Aqueous photothermographic imaging elements comprising aqueous silver halide emulsions precipitated in the presence of cationic starch peptizing agent

A process for preparing an ultrathin high bromide &lcub;111&rcub; tabular grain silver halide emulsion in a reaction vessel comprising the steps of (a) forming in the presence of a dispersing medium a population of silver halide grain nuclei containing twin planes, and (b) growing the silver halide grain nuclei containing twin planes to form high bromide &lcub;111&rcub; tabular silver halide grains by the addition of silver and halide ions, WHEREIN the majority of the silver added during growth step (b) is added at a pBr of less than 2.6 and in the presence of a triaminopyrimidine grain growth modifier containing mutually independent 4, 5 and 6 ring position amino substituents, the 4 and 6 ring position substituents being hydroamino substituents. High bromide ultrathin &lcub;111&rcub; tabular grain emulsions prepared by the process of the invention provide thinner tabular grains than that obtained in the absence of the triaminopyrimidine grain growth modifier. Additionally, the double jet process of the invention is highly controllable and commercially scalable.

Growing community of inventors

Rochester, NY, United States of America

Joe E Maskasky