High speed reflective radiographic material
View Patent ↗A reflective radiographic material is useful to provide images that can be viewed without a light box. This reflective radiographic material has a reflective support and a silver halide emulsion on one side of the support only. The material can be used with a single green- or blue-light emitting fluorescent intensifying screen as part of an imaging assembly. The reflective support enables the image in the radiographic material to be viewed without a light box and the speed of the material enables the use of low power X-radiation generating equipment.
1. A reflective radiographic material having a speed of at least 200 and comprising a reflective support that has first and second major surfaces, said reflective radiographic material having disposed on said first major reflective support surface only, one or more hydrophilic colloid layers including a silver halide emulsion layer.
2. The material of claim 1 wherein said reflective support is a resin-coated paper support.
3. The material of claim 1 wherein said silver halide emulsion layer comprises tabular silver halide grains that have an aspect ratio of at least 25, an average grain diameter of at least 2.5 μm, an average thickness of from about 0.07 to about 0.12 μm, and comprise at least 90 mol % bromide and up to 5 mol % iodide, both based on total silver in said grains.
4. The material of claim 1 wherein said silver halide emulsion layer comprises tabular silver halide grains having at least 95 mol % bromide and up to 3 mol % iodide, both based on the total silver in said grains.
5. The material of claim 3 wherein said tabular silver halide grains have an aspect ratio of from about 25 to about 45, and an average grain diameter of from about 2.5 to about 4.5 μm, and an average thickness of from about 0.07 to about 0.11 μm.
6. The material of claim 1 wherein said silver halide emulsion layer comprises silver halide grains that are dispersed in a hydrophilic polymeric vehicle mixture comprising at least 0.05% of oxidized gelatin, based on the total dry weight of said hydrophilic polymeric vehicle mixture.
7. The material of claim 6 wherein said silver halide emulsion layer comprises silver halide grains that are dispersed in a hydrophilic polymeric vehicle mixture comprising from about 0.1 to about 1.5% of oxidized gelatin, based on the total dry weight of said hydrophilic polymeric vehicle mixture.
8. The material of claim 1 having a total silver coverage of at least 13 and up to 18 mg/dm 2 , and the amount of polymer vehicle on said first major reflective support surface is from about 36 to about 40 mg/dm 2 .
9. The material of claim 1 comprising a single silver halide emulsion layer on said first major reflective support surface.
10. The material of claim 1 wherein said support comprises a microvoided continuous polyester first phase and a second phase dispersed within the continuous polyester first phase, said second phase comprising microvoids containing barium sulfate particles.
11. The material of claim 1 further comprising a protective overcoat disposed over said one or more hydrophilic colloid layers including a silver halide emulsion layer.
12. A reflective radiographic material having a speed of at least 800 and comprising a reflective resin-coated paper support that has first and second major surfaces, said reflective radiographic material having disposed on said first major reflective support surface, two or more hydrophilic colloid layers including a single silver halide emulsion layer,
said single silver halide emulsion layer comprising tabular silver halide grains that have an aspect ratio of from about 25 to about 40, an average grain diameter of from about 2.5 to about 4.5 μm, and an average thickness of from about 0.07 to about 0.11 μm, and comprise at least 95 mol % bromide and up to 1 mol % iodide, both based on total silver in said grains,
said material optionally comprising a protective overcoat disposed over all of said hydrophilic colloid layers,
wherein said tabular silver halide grains in said silver halide emulsion layer are dispersed in a hydrophilic polymeric vehicle mixture comprising from about 0.1 to about 1.5% of deionized oxidized gelatin, based on the total dry weight of said hydrophilic polymeric vehicle mixture,
the coverage of silver in said silver halide emulsion layer is from about 15 to about 18 mg/dm and the polymer vehicle coverage in said silver halide emulsion layer on said first major reflective support surface of from about 38 to about 40 mg/dm 2 .
13. An imaging assembly that has a system speed of at least 200 and comprises:
A) a radiographic material of claim 1 , and
B) a fluorescent intensifying screen or storage phosphor panel arranged on the imaging side of said radiographic material, said screen or panel having a screen speed of at least 100 and comprising an inorganic phosphor capable of absorbing X-rays and emitting electromagnetic radiation having a wavelength greater than 300 nm, said inorganic phosphor being coated in admixture with a polymeric binder in a phosphor layer onto a support.
14. The imaging assembly of claim 13 having a system speed of at least 800 wherein said radiographic material has a film speed of at least 800 and said fluorescent intensifying screen has a screen speed of at least 400.
15. A method of providing a black-and-white image comprising processing an exposed reflective radiographic material of claim 1 to provide a black-and-white image.
16. The method of claim 15 comprising exposing said reflective material with a fluorescent intensifying screen.
17. The method of claim 15 further comprising using said black-and-white image for a medical diagnosis.
18. The method of claim 15 wherein an image is obtained in said reflective radiographic material using less than 130 kVp power source of X-radiation.