Radiographic element
AssigneeEastman Kodak Company
InventorsRobert E. Dickerson, James E. Kelly, Donald R. Diehl, Ronda E. Factor
Life of this patent
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Abstract
A radiographic element is disclosed which exhibits high covering power, reduced crossover without emulsion desensitization, reduced wet pressure sensitivity, and can be fully processed in a rapid transport processor in less than 90 seconds. The radiographic is comprised of tabular grain emulsion layers on opposite sides of a transparent film support and processing solution decolorizable dye particles in hydrophilic colloid layers interposed between the emulsion layers and the support. Hydrophilic colloid on each side of the support is in the range of from 35 to 65 mg/dm.sup.2, with the interposed layer containing hydrophilic colloid in the amount of at least 10 mg/dm.sup.2.
Claims14
A radiographic element comprised of
- a film support capable of transmitting radiation to which said radiographic element is responsive having opposed major surfaces, and, coated on said opposed major surfaces,
- processing solution permeable hardenable hydrophilic colloid layers including
- at least one silver halide emulsion layer comprised of
- silver bromide or bromoiodide grains including tabular grains having a thickness of less than 0.3 .mu.m which have an average aspect ratio of greater than 5:1 and account for greater than 50 percent of the total grain projected area and
- spectral sensitizing dye adsorbed to the surface of said grains in an amount sufficient to substantiality optimally spectrally sensitize said emulsion layer and
- a layer interposed between said silver halide emulsion layer and said support containing a dye capable of absorbing radiation to which said emulsion layer coated on the opposite of said major surfaces is responsive to reduce crossover,
- characterized in that
- said dye in said interposed layer is, prior to processing, in the form of particles and present in an amount sufficient to reduce crossover to less than 10 percent and is capable of being substantially decolorized during processing,
- said interposed layer contains at least 10 mg/dm.sup.2 of hardenable hydrophilic colloid,
- said emulsion layers contain a combined silver coating coverage sufficient to produce a maximum density on processing in the range of from 3 to 4,
- a total of from 35 to 65 mg/dm.sup.2 of processing solution permeable hardenable hydrophilic colloid is coated on each of said opposed major surfaces of said support, and
- said processing solution permeable hydrophilic colloid layers are forehardened in an amount sufficient to reduce swelling of said layers to less than 300 percent, percent swelling being determined by (a) incubating said radiographic element at 38.degree. C. for 3 days at 50 percent relative humidity, (b) measuring layer thickness, (c) immersing said radiographic element in distilled water at 21.degree. C. for 3 minutes, and (d) determining the percent change in layer thickness as compared to the layer thickness measured in step (b),
- whereby said radiographic element exhibits high covering power, reduced crossover without emulsion desensitization, reduced wet pressure sensitivity, and can be developed, fixed, washed, and emerge dry to the touch in a 90 second 35.degree. C. process cycle consisting of
- ______________________________________ development 24 seconds at 40.degree. C., fixing 20 seconds at 40.degree. C., washing 10 seconds at 40.degree. C., and drying 20 seconds at 65.degree. C., ______________________________________
- where the remaining time is transport between processing steps, the development step employs the following developer:
- ______________________________________ Hydroquinone 30 g 1-Phenyl-3-pyrazolidone 1.5 g KOH 21 g NaHCO.sub.3 7.5 g K.sub.2 SO.sub.3 44.2 g Na.sub.2 S.sub.2 O.sub.5 12.6 g NaBr 35 g 5-Methylbenzotriazole 0.06 g Glutaraldehyde 4.9 g Water to 1 liter at pH 10.0, and ______________________________________ the fixing step employs the following fixing composition:
- ______________________________________ Ammonium thiosulfate, 60% 260.0 g Sodium bisulfite 180.0 g Boric acid 25.0 g Acetic acid 10.0 g Aluminum sulfate 8.0 g Water to 1 liter at pH 3.9 to 4.5. ______________________________________
A radiographic element comprised of a blue tinted film support capable of transmitting radiation to which said radiographic element is responsive having opposed major surfaces, and, coated on said opposed major surfaces,
- processing solution permeable hardenable hydrophilic colloid layers including
- at least one silver halide emulsion layer comprised of
- silver bromide or bromoiodide grains including tabular grains having a thickness of less than 0.2 .mu.m which have an average aspect ratio of at least 12:1 and account for greater than 70 percent of the total grain projected area and
- blue spectral sensitizing dye adsorbed to the surface of said grains in an amount sufficient to provide a monolayer coverage of from 25 to 100 percent of the surface area of said grains and capable of sensitizing said emulsion layer to at least 60 percent of its maximum attainable sensitivity and
- a layer interposed between said silver halide emulsion layer and said support containing a yellow dye capable of absorbing radiation to which said emulsion layer coated on the opposite of said major surfaces is responsive to reduce crossover,
- characterized in that
- said yellow dye in said interposed layer is, prior to processing, in the form of particles of less than 1 .mu.m in mean diameter present in an amount sufficient to provide an optical density of at least 1.00 in the spectral region of from 400 to 500 nm, thereby reducing crossover to less than 10 percent, said dye being capable of being substantially decolorized during processing,
- said interposed layer contains at least 10 mg/dm.sup.2 of hardenable hydrophilic colloid,
- said emulsion layers contain a combined silver coating coverage sufficient to produce a maximum density on processing in the range of from 3 to 4,
- a total of from 35 to 65 mg/dm.sup.2 of processing solution permeable hardenable hydrophilic colloid is coated on each of said opposed major surfaces of said support, and
- said processing solution permeable hydrophilic colloid layers are forehardened in an amount sufficient to reduce swelling of said layers to less than 200 percent, percent swelling being determined by (a) incubating said radiographic element at 38.degree. C. for 3 days at 50 percent relative humidity, (b) measuring layer thickness, (c) immersing said radiographic element in distilled water at 21.degree. C. for 3 minutes, and (d) determining the percent change in layer thickness as compared to the layer thickness measured in step (b),
- whereby said radiographic element exhibits high covering power, reduced crossover without emulsion desensitization, reduced wet pressure sensitivity, and can be developed, fixed, washed, and emerge dry to the touch in a 90 second 35.degree. C. process cycle consisting of
- ______________________________________ development 24 seconds at 40.degree. C., fixing 20 seconds at 40.degree. C., washing 10 seconds at 40.degree. C., and drying 20 seconds at 6.degree. C., ______________________________________
- where the remaining time is transport between processing steps, the development step employs the following developer:
- ______________________________________ Hydroquinone 30 g 1-Phenyl-3-pyrazolidone 1.5 g KOH 21 g NaHCO.sub.3 7.5 g K.sub.2 SO.sub.3 44.2 g Na.sub.2 S.sub.2 O.sub.5 12.6 g NaBr 35 g 5-Methylbenzotriazole 0.06 g Glutaraldehyde 4.9 g Water to 1 liter at pH 10.0, and ______________________________________
- the fixing step employs the following fixing composition:
- ______________________________________ Ammonium thiosulfate, 60% 260.0 g Sodium bisulfite 180.0 g Boric acid 25.0 g Acetic acid 10.0 g Aluminum sulfate 8.0 g Water to 1 liter at pH 3.9 to 4.5. ______________________________________
A radiographic element comprised of
- a blue tinted film support capable of transmitting radiation to which said radiographic element is responsive having opposed major surfaces, and, coated on said opposed major surfaces,
- processing solution permeable hardenable hydrophilic colloid layers including
- at least one silver halide emulsion layer comprised of
- silver bromide or bromoiodide grains including tabular grains having a thickness of less than 0.2 .mu.m which have an average aspect ratio of at least 12:1 and account for greater than 70 percent of the total grain projected area and
- green spectral sensitizing dye adsorbed to the surface of said grains in an amount sufficient to provide a monolayer coverage of from 25 to 100 percent of the surface area of said grains and capable of sensitizing said emulsion layer to at least 60 percent of its maximum attainable sensitivity and
- a layer interposed between said silver halide emulsion layer and said support containing a magenta dye capable of absorbing radiation to which said emulsion layer coated on the opposite of said major surfaces is responsive to reduce crossover,
- characterized in that
- said magenta dye in said interposed layer is, prior to processing, in the form of particles of less than 1 .mu.m in mean diameter present in an amount sufficient to provide an optical density of at least 1.00 in the spectral region of from 450 to 550 nm, thereby reducing crossover to less than 10 percent, said dye being capable of being substantially decolorized during processing,
- said interposed layer contains at least 10 mg/dm.sup.2 of hardenable hydrophilic colloid,
- said emulsion layers contain a combined silver coating coverage sufficient to produce a maximum density on processing in the range of from 3 to 4,
- a total of from 35 to 65 mg/dm.sup.2 of processing solution permeable hardenable hydrophilic colloid is coated on each of said opposed major surfaces of said support, and
- said processing solution permeable hydrophilic colloid layers are forehardened in an amount sufficient to reduce swelling of said layers to less than 200 percent, percent swelling being determined by (a) incubating said radiographic element at 38.degree. C. for 3 days at 50 percent relative humidity, (b) measuring layer thickness, (c) immersing said radiographic element in distilled water at 21.degree. C. for 3 minutes, and (d) determining the percent change in layer thickness as compared to the layer thickness measured in step (b),
- whereby said radiographic element exhibits high covering power, reduced crossover without emulsion desensitization, reduced wet pressure sensitivity, and can be developed, fixed, washed, and emerge dry to the touch in a 90 second 35.degree. C. process cycle consisting of
- ______________________________________ development 24 seconds at 40.degree. C., fixing 20 seconds at 40.degree. C., washing 10 seconds at 40.degree. C., and drying 20 seconds at 65.degree. C., ______________________________________
- where the remaining time is transport between processing steps, the development step employs the following developer:
- ______________________________________ Hydroquinone 30 g 1-Phenyl-3-pyrazolidone 1.5 g KOH 21 g NaHCO.sub.3 7.5 g K.sub.2 SO.sub.3 44.2 g Na.sub.2 S.sub.2 O.sub.5 12.6 g NaBr 35 g 5-Methylbenzotriazole 0.06 g Glutaraldehyde 4.9 g Water to 1 liter at pH 10.0, and ______________________________________
- the fixing step employs the following fixing composition:
- ______________________________________ Ammonium thiosulfate, 60% 260.0 g Sodium bisulfite 180.0 g Boric acid 25.0 g Acetic acid 10.0 g Aluminum sulfate 8.0 g Water to 1 liter at pH 3.9 to 4.5. ______________________________________
Dependencies are inferred from the claim text.