Silver Halide Identified-grain, Identified Emulsion Binder Other Than Nominal Gelatin, Or Identified Sensitizer Or Identified Desensitizer Containing Patents (Class 430/217)
  • Patent number: 4601976
    Abstract: A multilayer color photographic light-sensitive material containing no image-receiving layer is described, comprising a support, an internal latent image type direct reversal silver halide emulsion layer combined with a dye-providing substance, and a void layer between the support and the layer containing the dye-providing substance closest to the support.
    Type: Grant
    Filed: August 15, 1985
    Date of Patent: July 22, 1986
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Yukio Karino
  • Patent number: 4552828
    Abstract: A direct positive silver halide photographic emulsion which is able to provide a high maximum density and a low minimum density and having a high developing progress. The emulsion contains at least one of the sensitizing dyes represented by following general formula I and at least one of the compounds represented by general formula II:Formula I: ##STR1## Formula II: ##STR2## The substituents are defined in the specification.
    Type: Grant
    Filed: August 30, 1983
    Date of Patent: November 12, 1985
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Ichizo Toya, Yuji Mihara, Haruo Takei
  • Patent number: 4548887
    Abstract: Colored dye diffusion images are produced using a recording material containing, on a layer support (layer element 1), a first dye absorbent layer (layer element 2), a light-sensitive element containing silver halide emulsion layers and color-providing compounds (layer element 3) and optionally a second dye absorbent layer (layer element 4), in that order. An imagewise distribution of diffusible dyes is produced in the light-sensitive element in the course of development and transferred to the first dye absorbent layer.The light-sensitive element is then decomposed by a treatment which decomposes its layers, e.g. by means of a proteolytic enzyme, but leaves the first dye absorbent layer intact. The second dye absorbent layer optionally present, which has a lower mordanting capacity than the first dye absorbent layer and serves to prevent contamination of the developer bath with diffusible dyes, is also decomposed.
    Type: Grant
    Filed: July 3, 1984
    Date of Patent: October 22, 1985
    Assignee: AGFA-Gevaert A.G.
    Inventors: Gunter Helling, Wolfgang Himmelmann
  • Patent number: 4510235
    Abstract: A silver halide photographic emulsion containing a particular combination of dyes is described which prevents aggravated fogging of the emulsion under the influence of high temperature or the combination of high temperature and high humidity, and minimizes the degradation of sensitivity of the emulsion thus providing an emulsion of high stability to withstand the adverse effects of aging.
    Type: Grant
    Filed: April 26, 1984
    Date of Patent: April 9, 1985
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Toshinao Ukai, Masaki Okazaki, Haruo Takei, Ichizo Toya, Sadanobu Syuto
  • Patent number: 4504570
    Abstract: High aspect ratio tabular grain direct reversal silver halide emulsions are disclosed. The emulsions can be incorporated in photographic elements, such as multicolor photographic elements. Image transfer film units incorporating these direct reversal emulsions are specifically disclosed.
    Type: Grant
    Filed: December 23, 1983
    Date of Patent: March 12, 1985
    Assignee: Eastman Kodak Company
    Inventors: Francis J. Evans, Richard L. Daubendiek, Ronald G. Raleigh
  • Patent number: 4499181
    Abstract: A photographic recording material. On a support are provided a silver emulsion halide layer and a photographic layer. The photographic layer contains an indole compound represented by the general formula (I): ##STR1## wherein PUG represents a photographically useful group, Ball represents an organic group which has enough molecular weight and/or disposition to render the compound non-diffusible during processing of the photographic recording material with an alkaline medium and wherein the Ball contains a nitrogen atom which is directly attached to the 5th or 6th position of the indole ring. R.sub.1 represents a halogen atom or a monovalent organic group. R.sub.2 represents a hydrogen atom or a low molecular group attached, through a carbon atom, to the 2nd position of the indole ring. "m" represents an integer of zero to 3.
    Type: Grant
    Filed: June 2, 1983
    Date of Patent: February 12, 1985
    Assignee: Konishiroku Photo Ind., Co., Ltd.
    Inventors: Kazumasa Watanabe, Hidetaka Deguchi, Shunji Suginaka
  • Patent number: 4478929
    Abstract: Photographic dye image transfer film units are disclosed employing negative working high aspect ratio tabular grain silver halide emulsions. The dye image transfer film units can achieve a variety of advantages, such as reductions in silver coverage with diminished reductions in speed, diminished increases in minimum density levels, allowing a transferred image to be rapidly accessible for viewing, and producing lower minimum densities and higher maximum densities for a given time of development, and greater image discrimination. Improvements in other photographic characteristics (such as sharpness), advantageous layer order arrangements, and reduction or elimination of various layers, such as yellow filter layers and scavenger interlayers can be obtained also.
    Type: Grant
    Filed: November 21, 1983
    Date of Patent: October 23, 1984
    Assignee: Eastman Kodak Company
    Inventors: Cynthia G. Jones, Cliff O. Hill
  • Patent number: 4478928
    Abstract: The use of sulfinic acid radical substituted arylhydrazides in producing images in silver halide photographic elements is disclosed. The sulfinic acid radical substituted arylhydrazide can be incorporated in photographic silver halide, emulsions, and photographic elements. The sulfinic acid radical substituent is capable of activating the arylhydrazides, particularly for use at a lower alkaline pH. In negative working surface latent image forming emulsions the sulfinic acid radical substituted arylhydrazides permit higher speed or contrast to be achieved. In direct positive internal latent image forming emulsions increased nucleation activity and reduced rereversal can be achieved.
    Type: Grant
    Filed: May 11, 1983
    Date of Patent: October 23, 1984
    Assignee: Eastman Kodak Company
    Inventors: Thomas C. Hess, Karl E. Wiegers
  • Patent number: 4471044
    Abstract: The use of thioamido and alkynyl substituted heterocyclic ammonium salts in producing images in silver halide photographic elements is disclosed. The thioamido and alkynyl substituted heterocyclic ammonium salts can be incorporated in photographic silver halide emulsions. The thioamido substituent is capable of promoting adsorption of these salts to silver halide grain surfaces. In negative working surface latent image forming emulsions the thioamido and alkynyl substituted heterocyclic ammonium salts permit higher speeds to be achieved. In direct positive internal latent image forming emulsions nucleation activity and improved incubation stability can be achieved.
    Type: Grant
    Filed: June 13, 1983
    Date of Patent: September 11, 1984
    Assignee: Eastman Kodak Company
    Inventors: Richard L. Parton, Wilbur S. Gaugh, Karl E. Wiegers
  • Patent number: 4459347
    Abstract: The use of oxythioamido substituted arylhydrazides in producing images in silver halide photographic elements is disclosed. The oxythioamido substituted arylhydrazide can be incorporated in photographic silver halide emulsions. The oxythioamido substituent is capable of promoting adsorption of the arylhydrazide to silver halide grain surfaces. In negative working surface latent image forming emulsions the oxythioamido substituted arylhydrazides permit higher speeds to be achieved. In direct positive internal latent image forming emulsions increased nucleation activity can be achieved.
    Type: Grant
    Filed: May 11, 1983
    Date of Patent: July 10, 1984
    Assignee: Eastman Kodak Company
    Inventors: Richard L. Parton, James A. Friday
  • Patent number: 4444865
    Abstract: Blended emulsions for use in forming a direct-positive image are disclosed. The emulsions are comprised of a first, radiation-sensitive core-shell grain population having a relatively low coefficient of variation and a second, substantially smaller size grain population capable of internally trapping photolytically generated electrons. Photographic elements incorporating the blended emulsions exhibit improved covering power and can exhibit enhanced speed.
    Type: Grant
    Filed: September 15, 1982
    Date of Patent: April 24, 1984
    Assignee: Eastman Kodak Company
    Inventors: Robert A. Silverman, Harry A. Hoyen
  • Patent number: 4433050
    Abstract: A direct positive type light sensitive silver halide photographic material is disclosed. At least one layer containing an unfogged internal latent image type silver halide emulsion, is provided on a support, and an internal latent image type silver halide emulsion having fog centers in silver halide grains, is incorporated in said layer or in another constituent layer of the photographic material. A dye image forming substance may be incorporated in the same layer or in a separate layer to form a color diffusion transfer type light sensitive photograhic material. The photographic materials present a positive image having a high maximum density and a low minimum density.
    Type: Grant
    Filed: September 9, 1981
    Date of Patent: February 21, 1984
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Takao Abe, Satoru Hohnishi
  • Patent number: 4431728
    Abstract: There is disclosed a silver halide photographic light-sensitive material which comprises a support, a combination of an unfogged surface latent image type silver halide photographic emulsion and a material which is non-diffusible under alkali conditions and which is capable of releasing a diffusible development inhibitor or a precursor thereof as a result of cross oxidation with an oxidized product of a photographic developing agent; and a combination of an internal latent image type silver halide photographic emulsion whose silver halide grains contain therein, prior to development, fog nuclei and a dye image-forming material which is initially non-diffusible under alkaline conditions but which is capable of releasing a diffusible dye or a precursor thereof as a result of being oxidized by the oxidized product of said photographic developing agent.
    Type: Grant
    Filed: June 9, 1982
    Date of Patent: February 14, 1984
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventors: Takao Abe, Tatsuhiko Kobayashi
  • Patent number: 4423142
    Abstract: Photographic material and process suitable for producing by diffusion transfer a color image and comprising on a support at least two differently spectrally sensitive negative working silver halide emulsion layers (FIG. 3, layers 12, 14 and 16) and having operatively associated with each of said emulsion layers a different non-diffusing dye providing compound that is initially immobile in an alkali-permeable colloid medium and wherefrom by reduction in alkaline medium a dye or dye precursor can be split off in diffusible state, wherein at least one of said negative working silver halide emulsion layers is associated in water-permeable relationship with a visible light-sensitive direct-positive emulsion layer (FIG. 3, layers 13 and 15) whereby interimage effects can be obtained.
    Type: Grant
    Filed: February 18, 1982
    Date of Patent: December 27, 1983
    Assignee: AGFA-Gevaert, N.V.
    Inventor: Wilhelmus Janssens
  • Patent number: 4416969
    Abstract: A nucleating agent composition is described comprising a triazole substituted phenylhydrazide and an thiourea substituted phenylhydrazide wherein the molar ratio of the triazole substituted phenylhydrazide to the thiourea substituted phenylhydrazide is between 1:20 and 20:1. The described composition is useful in photographic emulsions, processing compositions and elements and provides excellent nucleation at low concentrations under a variety of processing conditions.
    Type: Grant
    Filed: September 1, 1982
    Date of Patent: November 22, 1983
    Assignee: Eastman Kodak Company
    Inventors: Paul M. Magee, Gareth B. Evans
  • Patent number: 4395478
    Abstract: A radiation-sensitive emulsion for use in forming a direct-positive image is disclosed. The emulsion is comprised of core-shell silver halide grains. The shell portions of the grains contain polyvalent metal ions to reduce rereversal.
    Type: Grant
    Filed: November 12, 1981
    Date of Patent: July 26, 1983
    Assignee: Eastman Kodak Company
    Inventor: Harry A. Hoyen
  • Patent number: 4387155
    Abstract: Photosensitive silver halide emulsions containing a green-sensitive dye of the formula ##STR1## wherein R is hydrogen or chlorine. The invention is also directed to the novel sensitizing dyes.
    Type: Grant
    Filed: May 26, 1981
    Date of Patent: June 7, 1983
    Assignee: Polaroid Corporation
    Inventors: Ruth L. Hill, Roger E. Jerry
  • Patent number: 4374923
    Abstract: A direct positive silver halide photographic light-sensitive material is described comprising a support having coated thereon at least one light-sensitive silver halide photographic emulsion layer, wherein at least one layer of the light-sensitive silver halide photographic emulsion layers and other hydrophilic colloid layers contains a compound represented by formula (I) ##STR1## wherein R.sup.1 and R.sup.2 can each represent a hydrogen atom, an aliphatic group, an aromatic group, or a heterocyclic group; R.sup.3 represents a hydrogen atom or an aliphatic group; R.sup.4 represents a hydrogen atom, an aliphatic group, or an aromatic group; and X represents a divalent aromatic group.
    Type: Grant
    Filed: November 17, 1981
    Date of Patent: February 22, 1983
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Shigeo Hirano, Tadao Sugimoto, Nobuyuki Tsujino
  • Patent number: 4362806
    Abstract: Photographic elements, multicolor filters and receivers are disclosed having supports providing microvessels for materials such as radiation-sensitive materials, imaging materials, mordants, silver precipitating agents and materials which are useful in conjunction with these materials. Processes of forming microvessels and introducing materials therein are also disclosed. Processes of forming images are disclosed employing microvessel containing elements. Image transfer processes are disclosed for producing one or a combination of silver and multicolor subtractive primary images alone or in combination with multicolor additive primary images.
    Type: Grant
    Filed: September 8, 1980
    Date of Patent: December 7, 1982
    Assignee: Eastman Kodak Company
    Inventor: Keith E. Whitmore
  • Patent number: 4358525
    Abstract: Photographically useful compounds such as photographic reagents and photographic dyes are blocked with a grouping which, under alkaline conditions, is cleaved from the compound by an intramolecular nucleophilic displacement reaction. The compounds are resistant to unblocking under storage conditions, but are uniformly unblocked under conditions encountered during photographic processing.
    Type: Grant
    Filed: August 12, 1981
    Date of Patent: November 9, 1982
    Assignee: Eastman Kodak Company
    Inventors: Jared B. Mooberry, William C. Archie, Jr.
  • Patent number: 4347301
    Abstract: The present invention is directed to photosensitive elements and to diffusion transfer film units employing said elements wherein said photosensitive element includes a plurality of essential layers, including a first photosensitive silver halide layer and a second photosensitive silver halide layer, said first and second silver halide layers being sensitized to substantially the same spectral absorption range; a spacer layer intermediate and contiguous to said first and second silver halide layers, said spacer layer consisting essentially of inert particles which are substantially non-swelling in alkali, and substantially non-film forming; wherein said inert particles are equal to or less than the average diameter of the silver halide grains in said first and second silver halide layers and wherein said silver halide grains are 2.
    Type: Grant
    Filed: November 26, 1980
    Date of Patent: August 31, 1982
    Assignee: Polaroid Corporation
    Inventor: Peter O. Kliem
  • Patent number: 4345016
    Abstract: A color photographic sensitive material containing a polymer comprising at least 1 mol % of a repeating unit represented by formula (I) ##STR1## wherein A represents a divalent group, n is 1 or 2, R.sub.1 represents hydrogen, a halogen atom or an alkyl group, and R.sub.2, R.sub.3, and R.sub.4 each represents hydrogen, a halogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an amino group, an acylamino group, or a sulfonamide group, and R.sub.3 and R.sub.4 together can form an aromatic ring, provided that the total of carbon atoms of R.sub.2, R.sub.3, and R.sub.4 is 60 or less.
    Type: Grant
    Filed: July 1, 1981
    Date of Patent: August 17, 1982
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Osamu Takahashi, Nobutaka Ohki, Kozo Aoki
  • Patent number: 4341858
    Abstract: Direct-positive photographic emulsions and elements which include internal-image silver halide grains, a nucleating amount of a hydrazine compound and a redox dye releaser are improved by the incorporation of a nucleation-promoting amount of a quinone oxidizing agent. Diffusion transfer images made from elements using these emulsions exhibit improved image discrimination and improved maximum density.
    Type: Grant
    Filed: May 1, 1981
    Date of Patent: July 27, 1982
    Assignee: Eastman Kodak Company
    Inventors: Eleanor Chaffee, Richard C. Tuites
  • Patent number: 4332885
    Abstract: Photographic sensitive materials for a color-diffusion transfer process which are particularly useful in a wide variety of temperature and climate conditions are disclosed. The materials are comprised of a red-sensitive emulsion layer; a green-sensitive emulsion layer; and a blue-sensitive emulsion layer on a support wherein at least one of the layers is comprised of a plurality of additional layers. Two or more of the additional layers are direct reversal photographic emulsion layers of higher and lower sensitivity which are not previously fogged. The emulsion layer having lower sensitivity has a gradation of 1.8 or more resulting in a hard tone.
    Type: Grant
    Filed: April 7, 1981
    Date of Patent: June 1, 1982
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Hideki Ohmatsu
  • Patent number: 4323635
    Abstract: A color photographic material suitable for processing with an alkaline solution in the presence of a developing agent is described, comprising a support and, in sequence, the following five layers:(1) a first emulsion layer containing an internal latent image forming direct reversal silver halide emulsion that is selectively sensitive to light in a first spectral region;(2) a first color material layer containing a ballasted dye releasing redox compound that provides a dye image that selectively absorbs light in the first spectral region;(3) an intermediate layer containing a ballasted reducing agent that captures an oxidized developing agent or electron transfer agent;(4) a second emulsion layer containing an internal latent image forming direct reversal silver halide emulsion that is selectively sensitive to light in a second spectral region; and(5) a second color material layer containing a ballasted dye releasing redox compound that provides a dye image that selectively absorbs light in the second spectra
    Type: Grant
    Filed: November 6, 1980
    Date of Patent: April 6, 1982
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Yasushi Oishi
  • Patent number: 4302525
    Abstract: Photosensitive silver halide emulsions for use in diffusion transfer processes are stabilized without adversely affecting spectral sensitization by the following steps: (a) spectrally sensitizing the silver halide grains; (b) lowering the pH of the emulsion from a first pH of the emulsion subsequent to chemical ripening to a pH of about 5.5 to 4.0 and/or increasing the Br ion/Ag ratio to at least 5 mg Br ion/gAg and, subsequent to steps (a) and (b), (c) adding 5-80 mg/gAg to said emulsion of a stabilizer selected from the group consisting of an hydroxy triazaindene, an amino triazaindene, an hydroxy tetrazaindene, an amino tetrazaindene, an hydroxy pentazaindene and an amino pentazaindene.
    Type: Grant
    Filed: February 15, 1980
    Date of Patent: November 24, 1981
    Assignee: Polaroid Corporation
    Inventors: T. Nelson Baker, III, Bernard Zuckerman
  • Patent number: 4287291
    Abstract: This invention relates to a light-sensitive color photographic material and more particularly to a diffusion transfer color photographic film unit, the processing composition of which contains a specific saturated aliphatic or saturated alicyclic alcohol.
    Type: Grant
    Filed: November 21, 1979
    Date of Patent: September 1, 1981
    Assignee: Konishiroku Photo Industry Co., Ltd.
    Inventor: Kaoru Onodera
  • Patent number: 4278748
    Abstract: Novel triazole-substituted phenylhydrazide nucleating agents are disclosed as well as silver halide photographic emulsions and elements containing silver halide grains capable of forming an internal latent image having the nucleating agents adsorbed to the surface of the silver halide grains.
    Type: Grant
    Filed: July 25, 1979
    Date of Patent: July 14, 1981
    Assignee: Eastman Kodak Company
    Inventors: Jasbir Sidhu, Michael J. Simons, Miroslav V. Mijovic
  • Patent number: 4276364
    Abstract: Novel 3,3-disubstituted acylhydrazinophenylthiourea nucleating agents are disclosed as well as silver halide photographic emulsions and elements containing silver halide grains capable of forming an internal latent image having the nucleating agents adsorbed to the surface of the silver halide grains. Imaging processes in which these materials participate are also disclosed.
    Type: Grant
    Filed: June 23, 1980
    Date of Patent: June 30, 1981
    Assignee: Eastman Kodak Company
    Inventor: Ronald E. Leone
  • Patent number: 4275145
    Abstract: A method for dispersing an oil-soluble photographic additive into a hydrophilic colloid composition is disclosed wherein a solution of an oil-soluble photographic additive in an organic solvent or the melted oil-soluble photographic additive is dispersed in a hydrophilic colloid containing an anionic surface active agent and lecithin together with a gelatin derivative.
    Type: Grant
    Filed: December 11, 1979
    Date of Patent: June 23, 1981
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Takeshi Mikami
  • Patent number: 4269927
    Abstract: This disclosure relates to high chloride silver halide emulsions and photographic elements containing silver halide grains which are internally doped with cadmium, lead, zinc or mixtures thereof in concentrations up to 7.times.10.sup.-5 mole/mole of silver halide.
    Type: Grant
    Filed: July 16, 1980
    Date of Patent: May 26, 1981
    Assignee: Eastman Kodak Company
    Inventor: Robert E. Atwell
  • Patent number: 4255511
    Abstract: A direct positive light-sensitive silver halide photographic material comprising a support having thereon a layer containing a compound represented by the formula (I): ##STR1## wherein R.sub.1 represents an aliphatic residue or an aromatic residue; R.sub.2 represents a hydrogen atom, an aliphatic residue, or an aromatic residue; X.sub.1 and X.sub.2, which may be the same or different, each represents a divalent aromatic residue; and Y represents --R--, --O--R or --S--R-- wherein R represents a divalent aliphatic residue and the O or S is bonded to X.sub.1. The compound is particularly effective in combination with a diffusible dye releasing dye image providing compound having an o-hydroxyarylsulfamoyl group.
    Type: Grant
    Filed: April 4, 1979
    Date of Patent: March 10, 1981
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Shigeo Hirano, Keiichi Adachi, Nobuyuki Tsujino
  • Patent number: 4250244
    Abstract: Photosensitivity of a blue-sensitive emulsion in a multi-color diffusion transfer photographic system is enhanced by sensitizing the emulsion with certain 3,3'-disubstituted 4,5-benzothia-thiacyanine betaines.
    Type: Grant
    Filed: February 2, 1977
    Date of Patent: February 10, 1981
    Assignee: Polaroid Corporation
    Inventors: Alan L. Borror, Ruth L. Hill
  • Patent number: 4245037
    Abstract: A direct positive light-sensitive silver halide photographic material comprising a support having thereon a layer containing a compound represented by the formula (I): ##STR1## wherein R.sub.1 represents an aliphatic residue or an aromatic residue; R.sub.2 represents a hydrogen atom, an aliphatic residue, or an aromatic residue; X.sub.1 and X.sub.2, which may be the same or different, each represents a divalent aromatic residue; and Y represents ##STR2## or a direct bond wherein the O or S is bonded to X.sub.1 ; R represents a divalent aliphatic residue and R.sub.3 represents an aliphatic residue or an aromatic residue. The compound is particularly effective in combination with a diffusible dye releasing dye image providing compound having an o-hydroxyarylsulfamoyl group.
    Type: Grant
    Filed: October 25, 1979
    Date of Patent: January 13, 1981
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Nobuyuki Tsujino, Shigeo Hirano, Keiichi Adachi
  • Patent number: 4232107
    Abstract: Said material contains a quinone-type compound which corresponds to one of the formulae (A) or (B) and which is capable in reduced state and under alkaline conditions of releasing a photographically useful group e.g. a dye: ##STR1## wherein: each of (Nuox).sup.1 and (Nuox).sup.2 represents an oxidized nucleophilic group,Z represents a bivalent atomic group which is electronegative,Q together with the Z group represents a releasable photographically useful group,each of R.sup.1, R.sup.2 and R.sup.3 is hydrogen, halogen, alkyl, alkoxy, or an acylamino group or R.sup.1 and R.sup.2 in adjacent positions on the ring form a ring fused with the remainder of the molecule, or R.sup.2 and R.sup.3 together are fused with the remainder of the molecule.each of R.sup.4 and R.sup.5 represents hydrogen or a hydrocarbon group.At least one of the substituents R.sup.1, R.sup.2, R.sup.3, R.sup.4 or R.sup.5 is a ballasting group X.
    Type: Grant
    Filed: March 15, 1979
    Date of Patent: November 4, 1980
    Assignee: AGFA-GEVAERT N.V.
    Inventor: Wilhelmus Janssens
  • Patent number: T105001
    Abstract: The use of thioamido and alkynyl substituted heterocyclic ammonium salts in producing images in silver halide photographic elements is disclosed. The thioamido and alkynyl substituted heterocyclic ammonium salts can be incorporated in photographic silver halide emulsions. The thioamido substituent is capable of promoting adsorption of these salts to silver halide grain surfaces. In negative working surface latent image forming emulsions the thioamido and alkynyl substituted heterocyclic ammonium salts permit higher speeds to be achieved. In direct positive internal latent image forming emulsions nucleation activity and improved incubation stability can be achieved.
    Type: Grant
    Filed: February 27, 1984
    Date of Patent: January 1, 1985
    Inventors: Richard L. Parton, Wilbur S. Gaugh, Karl E. Wiegers
  • Patent number: RE32097
    Abstract: Blended emulsions for use in forming a direct-positive image are disclosed. The emulsions are comprised of a first, radiation-sensitive core-shell grain population having a relatively low coefficient of variation and a second, substantially smaller size grain population capable of .Iadd.internally forming a latent image by .Iaddend.internally trapping photolytically generated electrons. Photographic elements incorporating the blended emulsions exhibit improved covering power and can exhibit enhanced speed.
    Type: Grant
    Filed: July 2, 1984
    Date of Patent: March 25, 1986
    Assignee: Eastman Kodak Company
    Inventors: Robert A. Silverman, Harry A. Hoyen