Eastman-kodak Company

Other

Jeffrey S Baugher

Robert E Dickerson

Alan S Fitterman

Lloyd A Lobo

Barry M Brown

Dirk J Hasberg

Douglas L Oehlbeck

James E Novak

A process for preparing a concentrated photographic spectral sensitizing dye-water composition which comprises adding an anionic sensitizing dye to an aqueous medium in the substantial absence of organic solvent, and agitating the combined dye and aqueous medium, wherein the anionic dye forms a liquid-crystalline dye phase in the aqueous medium and the agitation is performed in the presence of a nonionic surfactant having an HLB of less than 12 and an aqueous solubility at 25&deg; C. of greater than 10 ppm, which nonionic surfactant is in the aqueous medium at a level of from 10 to 1000 ppm. In a specific embodiment of the invention, where the viscosity (at 0.1 s shear rate) of the dye-water composition in the absence of the nonionic surfactant would be greater than 100 cp and especially where such viscosity would be greater than 500 cp, the surfactant is preferably present at a level sufficient to substantially reduce air entrainment during agitation of the dye-water composition.

Process for the preparation of concentrated dye-water compositions

A direct X-ray dental film is disclosed that, following imagewise exposure, can be removed from its opaque package and processed in room light. The film is comprised of emulsion and protective layers that contain dye particles which can be decolorized during processing. The dye particles provide an average density of greater than 3.0 over a spectral range of above 320 nm over which the silver halide exhibits an absorption coefficient of at least 0.5 cm.sup.-1. For additional protection the emulsion layers contain desensitizer adsorbed to the silver halide grains to reduce their sensitivity to light without significantly reducing their sensitivity to X-radiation.

Direct dental X-ray films adapted for room light handling

Black-and-white elements, such as radiographic films, can be processed in roomlight because they include certain light absorbing dyes and desensitizers. Processing is carried out by processing the exposed element using a two-stage process in the same light-tight processing container. In the first stage, development is initiated with a developing composition having a pH of from about 10 to about 12.5, and comprising an appropriate black-and-white developing agent in a concentration of from about 0.1 to about 0.5 mol/l, and a sulfite at from about 0.25 to about 0.7 mol/l. After an appropriate time, a fixing agent (other than a sulfite) is introduced into the processing container to provide a combined developing/fixing compositions, and development and fixing are carried out simultaneously. The processing method is carried out quickly, usually within about 90 seconds, including a washing step at the end. The presence of sulfite and high pH in both stages decolorize or deactivate the particulate dyes.

Composition for processing roomlight handleable radiographic films using

Direct X-ray films are disclosed capable of being handled in room light prior to and during processing. The films contain silver halide grains responsive to X-radiation that are sulfur sensitized. The films also contain a combination of processing solution bleachable dyes chosen to provide prior to processing (a) an average density of greater than 3.0 over a first, continuous spectral sensitivity range extending from a minimum wavlength of 320 nm over which the silver halide grains exhibit an absorption coefficient of at least 0.5 cm.sup.-1 and (b) a density of greater than 3.0 throughout a second spectral range including wavelengths of from 600 to 650 nm.

Direct X-ray elements capable of handling in ambient light

Method for processing roomlight handleable radiographic films using

Black-and-white elements, such as radiographic films, can be handled and processed in roomlight because they include certain light absorbing dyes and desensitizers. Processing is carried out by developing the exposed element using a developing composition having a pH of less than 10. The developed elements are fixed using a fixing composition having a pH of from 10 to 11.5, and comprising specific amounts of fixing agent and sulfite to solubilize silver halide and to bleach or decompose the light absorbing dyes. The processing method is carried out quickly, usually within 120 seconds.

Growing community of inventors

Rochester, NY, United States of America

Jeffrey S Baugher