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US4520098A Expired / Lapsed US ⏱️ 0.0 years remaining

Photographic element exhibiting reduced sensitizing dye stain

Assignee: Eastman Kodak Co
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Filing: 1984-05-31
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Granted: 1985-05-28
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Expires: 2004-05-31
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Abstract

Abstract A spectrally sensitized silver halide photographic element capable of producing a stable, viewable silver image on development and fixing out is disclosed. The latent image forming silver halide grains in the image recording emulsion layer or layers of the photographic element are silver bromide, chloride, or chlorobromide grains. At least one of the image recording emulsion layers contains spectrally sensitized tabular grains. Located in proximity to the spectrally sensitized tabular grains are relatively fine high iodide silver halide grains capable of being dissolved during fixing out.

Inventors

  • 👤 Robert E. Dickerson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 10:12
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/005; G03C1/0051; G03C1/06; G03C1/08; G03C1/10; G03C1/12; G03C1/14; G03C1/16; G03C1/18; G03C1/22; G03C1/24; G03C2001/0055; G03C1/035; G03C2001/03564; G03C5/00; G03C5/16; G03C2005/168; G03C2200/00; G03C2200/11; G03C2200/38; Y; Y10; Y10S; Y10S430/00; Y10S430/167

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 168 words
In a photographic element capable of producing a stable, viewable silver image on development in an aqueous alkaline processing solution and fixing out comprising a support and one or more image recording silver halide emulsion layers each comprised of a dispersing medium and latent image forming silver halide grains, said halide consisting essentially of chloride, bromide, or mixtures thereof, at least one of said image recording silver halide emulsion layers being comprised of spectral sensitizing dye adsorbed to the surface of tabular latent image forming silver halide grains having a thickness of less than 0.5 μm and an average aspect ratio of at least 5:1 accounting for at least 35 percent of the total projected area of said latent image forming silver halide grains present in said silver halide emulsion layer, the improvement comprising high iodide silver halide grains of less than 0.25 μm in mean diameter located in proximity to said tabular silver halide grains and limited to a concentration capable of being dissolved on fixing out.
Claim 2
Dependent Claim 168 words
In a photographic element capable of producing a stable, viewable silver image on development in an aqueous alkaline processing solution and fixing out comprising a support and one or more image recording silver halide emulsion layers each comprised of a dispersing medium and latent image forming silver halide grains, said halide consisting essentially of chloride, bromide, or mixtures thereof, at least one of said image recording silver halide emulsion layers being comprised of spectral sensitizing dye adsorbed to the surface of tabular latent image forming silver halide grains having a thickness of less than 0.5 μm and an average aspect ratio of at least 5:1 accounting for at least 35 percent of the total projected area of said latent image forming silver halide grains present in said silver halide emulsion layer, the improvement comprising high iodide silver halide grains of less than 0.25 μm in mean diameter located in proximity to said tabular silver halide grains and limited to a concentration capable of being dissolved on fixing out.
Claim 3
Dependent Claim 34 words
A photographic element according to claim 1 in which the iodide present in said high iodide silver halide grains is less than 5 mole percent of the total halide present in said photographic element.
Claim 4
Dependent Claim 34 words
A photographic element according to claim 2 in which the iodide present in said high iodide silver halide grains is less than 3 mole percent of the total halide present in said photographic element.
Claim 5
Dependent Claim 24 words
A photographic element according to claim 1 in which said high iodide silver halide grains have a mean diameter of less than 0.1 μm.
Claim 6
Dependent Claim 34 words
A photographic element according to claim 1 in which said high iodide silver halide grains are present in said image recording silver halide emulsion layer containing said tabular latent image forming silver halide grains.
Claim 7
Dependent Claim 40 words
A photographic element according to claim 1 in which said high iodide silver halide grains are present in a hydrophilic colloid layer adjacent to said image recording silver halide emulsion layer containing said tabular latent image forming silver halide grains.
Claim 8
Dependent Claim 26 words
A photographic element according to claim 6 in which said hydrophilic colloid layer containing said high iodide silver halide grains overlies said image recording emulsion layer.
Claim 9
Dependent Claim 42 words
A photographic element according to claim 1 in which said spectral sensitizing dye is present in an amount sufficient to form a monolayer coverage of from 25 to 100 percent of the total available surface area of said tabular silver halide grains.
Claim 10
Dependent Claim 28 words
A photographic element according to claim 1 in which said high iodide silver halide grains are comprised of at least 90 mole percent iodide, based on total halide.
Claim 11
Dependent Claim 23 words
A photographic element according to claim 9 in which the halide content of said high iodide silver halide grains consists essentially of iodide.
Claim 12
Dependent Claim 80 words
A photographic element according to claim 1 in which said tabular grain containing image recording silver halide emulsion layer is a high aspect ratio tabular grain emulsion layer wherein the silver halide grains having a thickness of less than 0.3 μm and a diameter of at least 0.6 μm have an average aspect ratio of greater than 8:1 and account for at least 50 percent of the total projected area of the silver halide grains present in said emulsion layer.
Claim 13
Dependent Claim 71 words
A photographic element according to claim 1 in which said tabular grain containing image recording emulsion layer is a thin, intermediate aspect ratio tabular grain emulsion layer wherein the tabular silver halide grains having a thickness of less than 0.2 μm and average aspect ratio of from 5:1 to 8:1 account for at least 50 percent of the total projected area of the silver halide grains present in said emulsion layer.
Claim 14
Dependent Claim 235 words
In a radiographic element capable of producing a stable, viewable silver image on development in an aqueous alkaline processing solution and fixing out comprised of first and second image recording silver halide emulsion layers each comprised of a dispersing medium and latent image forming silver bromide grains, a film support interposed between said emulsion layers capable of transmitting radiation to which said image recording emulsion layers are responsive, at least said first image recording silver halide emulsion layer being a high aspect ratio tabular grain emulsion layer wherein the latent image forming silver bromide grains having a thickness of less than 0.3 μm and a diameter of at least 0.6 μm have an average aspect ratio of greater than 8:1 and account for at least 50 percent of the total projected area of the latent image forming silver bromide grains present in said first emulsion layer, said high aspect ratio tabular emulsion layer containing spectral sensitizing dye in an amount sufficient to form a monolayer coverage of from 25 to 100 percent of the total available surface area of said tabular silver bromide grains, the improvement comprising high iodide silver halide grains of from 0.25 μm to 0.01 μm in mean diameter located in proximity to said tabular silver bromide grains of said first emulsion layer in a concentration of less than 3 mole percent, based on total halide present in said first emulsion layer.
Claim 15
Dependent Claim 235 words
In a radiographic element capable of producing a stable, viewable silver image on development in an aqueous alkaline processing solution and fixing out comprised of first and second image recording silver halide emulsion layers each comprised of a dispersing medium and latent image forming silver bromide grains, a film support interposed between said emulsion layers capable of transmitting radiation to which said image recording emulsion layers are responsive, at least said first image recording silver halide emulsion layer being a high aspect ratio tabular grain emulsion layer wherein the latent image forming silver bromide grains having a thickness of less than 0.3 μm and a diameter of at least 0.6 μm have an average aspect ratio of greater than 8:1 and account for at least 50 percent of the total projected area of the latent image forming silver bromide grains present in said first emulsion layer, said high aspect ratio tabular emulsion layer containing spectral sensitizing dye in an amount sufficient to form a monolayer coverage of from 25 to 100 percent of the total available surface area of said tabular silver bromide grains, the improvement comprising high iodide silver halide grains of from 0.25 μm to 0.01 μm in mean diameter located in proximity to said tabular silver bromide grains of said first emulsion layer in a concentration of less than 3 mole percent, based on total halide present in said first emulsion layer.
Claim 16
Dependent Claim 30 words
A radiographic element according to claim 13 in which said high iodide silver halide grains consist essentially of silver iodide and have a mean diameter of less than 0.10 μm.
Claim 17
Dependent Claim 27 words
A radiographic element according to claim 14 in which said silver iodide grains are present in a hydrophilic colloid layer adjacent said first silver bromide emulsion layer.
Claim 18
Dependent Claim 47 words
A radiographic element according to claim 14 in which said first and second silver bromide emulsion layers are each high aspect ratio tabular grain emulsion layers and said high iodide silver halide grains are located in proximity to each of said high aspect ratio tabular emulsion layers.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-05-27 1988-11-26 1989-05-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-05-27 1992-11-26 1993-05-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-05-27 1996-11-26 1997-05-28 $7700.00 Window Closed / Lapsed

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