Abstract: A process of preparing a high bromide tabular grain emulsion comprising a dispersion medium and silver halide grains including tabular grains having {111} major faces and an aspect ratio of at least 2, which contain greater than 50 mole percent bromide, based on silver, and which account for greater than 50 percent of total grain projected area, where such tabular grains have an average aspect ratio of at least 5, the process comprising (i) in a grain nucleation step creating in a dispersing medium tabular silver halide grain nuclei containing parallel twin planes and (ii) in a grain growth step subsequently growing the tabular grain nuclei into tabular grains in a silver halide reaction vessel by adding a silver ion source and a halide ion source to the reaction vessel and precipitating silver halide onto the tabular grain nuclei, wherein thiocyanate ion is introduced into the silver halide reaction vessel prior to the addition of at least the final 10 mole percent of the total silver added to the

Abstract: High-speed black-and-white photothermographic emulsions and materials comprise chemically sensitized photosensitive silver halide grains, at least 70% of the total photosensitive silver halide projected area being provided by tabular silver halide grains comprising at least 70 mole % bromide (based on total silver halide). The tabular grains have an average thickness of at least 0.02 &mgr;m and up to and including 0.10 &mgr;m, an equivalent circular diameter of at least 0.5 &mgr;m and up to and including 8 &mgr;m, and an aspect ratio of at least 5:1. These high-speed materials can be imaged in any suitable fashion using ultraviolet, visible, infrared, or X-radiation. In one embodiment, they have one or more thermally developable layers on both sides of the support and can be imaged using X-radiation with or without a phosphor intensifying screen in an imaging assembly.

Abstract: The invention relates to a solution for forming silver halide emulsions comprising water, a gelatin containing less than 30 micromoles of methionine per gram of gelatin, and at least one antifoamant of Formula I(H.sub.3 C).sub.3 Si--(OSi(CH.sub.3).sub.2).sub.m --OSi(CH.sub.3).sub.3wherein m is the average number of dimethyl siloxane units.

Abstract: The invention relates to a radiation-sensitive silver halide emulsion comprisingsilver halide grains including tabular grains(a) having {111} major faces,(b) containing greater than 70 mole percent bromide, based on silver,(c) accounting for greater than 90 percent of total grain projected area,(d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m,(e) exhibiting an average thickness of less than 0.07 .mu.m, and(f) having latent image forming chemical sensitization sites on the surfaces of the tabular grains, anda spectral sensitizing dye adsorbed to the surfaces of the tabular grains,wherein the surface chemical sensitization sites include at least one silver salt epitaxially located on said tabular grains adsorbed onto said grains during grain forming or sensitizing and said emulsion further comprising at least one sulfodihydroxy aryl compound represented by the Formulas I or II ##STR1## wherein X and Y represent an SO.sub.

Abstract: The invention provides a radiation-sensitive silver halide emulsion comprisingsilver halide grains including tabular grains(a) having {111} major faces(b) containing greater than 70 mole percent bromide, based on silver,(c) accounting for greater than 90 percent of total grain projected area,(d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m,(e) exhibiting an average thickness of less than 0.07 .mu.m, and(f) having latent image forming chemical sensitization sites on the surfaces of the tabular rains, anda spectral sensitizing dye adsorbed to the surfaces of the tabular grains,wherein the surface chemical sensitization sites include at least one silver salt epitaxially located on said tabular rains and wherein said grains further comprise a mercapto compound represented by Formula III ##STR1## where R.sup.1 is an aliphatic or aromatic radical containing up to 20 carbon atoms.

Abstract: A chemically and spectrally sensitized ultrathin tabular grain emulsion is disclosed including tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (e) exhibiting an average thickness of less than 0.07 .mu.m.It has been observed that increased speed and contrast as well as improvements in speed-granularity relationships can be realized when the surface chemical sensitization sites include epitaxially deposited silver halide protrusions forming epitaxial junctions with the tabular grains, the protrusions (a) being located on up to 50 percent of the surface area of the tabular grains, (b) having a higher overall solubility than at least that portion of the tabular grains forming epitaxial junctions with the protrusions, and (c) forming a face centered cubic crystal lattice.

Abstract: A chemically and spectrally sensitized ultrathin tabular grain emulsion is disclosed including tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide and at least 0.25 mole percent iodide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (e) exhibiting an average thickness of less than 0.07 .mu.m.

Abstract: A chemically and spectrally sensitized ultrathin tabular grain emulsion is disclosed including tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide and at least 0.25 mole percent iodide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (e) exhibiting an average thickness of less than 0.07 .mu.m.

Abstract: A chemically and spectrally sensitized tabular grain emulsion is disclosed including tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide and at least 0.25 mole percent iodide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (f) exhibiting an average thickness in the range of from less than 0.3 .mu.m to at least 0.07 .mu.m.

Abstract: A chemically and spectrally sensitized tabular grain emulsion is disclosed including tabular grains (a) having major faces, (b) containing greater than 70 mole percent bromide and at least 0.25 mole percent iodide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (f) exhibiting an average thickness in the range of from less than 0.3 .mu.m to at least 0.07 .mu.m.

Abstract: A chemically and spectrally sensitized ultrathin tabular grain emulsion is disclosed including tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (e) exhibiting an average thickness of less than 0.07 .mu.m.Improved sensitivity is observed when the surface chemical sensitization sites include silver halide protrusions of a face centered cubic crystal lattice structure forming epitaxial junctions with the tabular grains and having a higher overall solubility than at least that portion of the tabular grains forming epitaxial junctions with the protrusions and a sensitivity enhancing combination of dopants are contained in the silver halide grains including a first sensitivity enhancing dopant capable of providing shallow electron trapping sites and a second sensitivity enhancing selenium dopant.

Abstract: A chemically and spectrally sensitized ultrathin tabular grain emulsion is disclosed including tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, and (e) exhibiting an average thickness of less than 0.07 .mu.m.It has been observed that increased speed and contrast as well as improvements in speed-granularity relationships can be realized when the surface chemical sensitization sites include epitaxially deposited silver halide protrusions forming epitaxial junctions with the tabular grains, the protrusions (a) being located on up to 50 percent of the surface area of the tabular grains, (b) having a higher overall solubility than at least that portion of the tabular grains forming epitaxial junctions with the protrusions, and (c) forming a face centered cubic crystal lattice.

Abstract: An improved spectrally sensitized ultrathin tabular grain emulsion is disclosed in which tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide and at least 0.25 mole percent iodide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, (e) exhibiting an average thickness of less than 0.07 .mu.m, and (f) having latent image forming chemical sensitization sites on the surfaces of the tabular grains, are spectrally sensitized. The speed-granularity relationship of the emulsion is improved by employing in forming the surface chemical sensitization sites at least one silver salt epitaxially located on tabular grain surface sites that contain increased iodide concentrations.

Abstract: An improved spectrally sensitized ultrathin tabular grain emulsion is disclosed in which tabular grains (a) having {111} major faces, (b) containing greater than 70 mole percent bromide, based on silver, (c) accounting for greater than 90 percent of total grain projected area, (d) exhibiting an average equivalent circular diameter of at least 0.7 .mu.m, (e) exhibiting an average thickness of less than 0.07 .mu.m, and (f) having latent image forming chemical sensitization sites on the surfaces of the tabular grains, are spectrally sensitized and improved by employing in forming the surface chemical sensitization sites at least one silver salt epitaxially located on the tabular grains.

Abstract: Novel tabular grain emulsions and a process for their preparation are disclosed in which silver bromoiodide tabular grains account for greater than 97 percent of total grain projected area and the coefficient of variation of the total grain population is less than 25 percent. This is achieved by forming in a first reaction vessel and transporting to a second reaction vessel a population of silver bromide grain nuclei in the form of regular octahedra having an equivalent circular diameter of less than 40 nanometers and a coefficient of variation of less than 50 percent and in the second reaction vessel converting the grain nuclei into a grain population containing parallel twin planes in more than 90 percent of the grains, so that upon further growth silver bromoiodide tabular grains of desired properties can be realized.

Abstract: The present invention is directed to a process of precipitating for use in photography a thin tabular grain silver bromide or bromoiodide emulsion within a novel range of low bromide ion concentrations (high pBr levels) at the nucleation stage. A variety of advantages can be realized, including thinner and/or larger diameter tabular grains and novel tabular grain forms.

Abstract: Moderate camera speed photographic elements for producing subtractive primary dye images are disclosed, including one emulsion layer comprised of silver bromide or bromoiodide grains having a mean diameter in the range of from 0.4 to 0.55 .mu.m including tubular grains having an aspect ratio of greater than 8:1 accounting for at least 50 percent of the total projected area of the grains in the emulsion layer and being positioned to receive imaging radiation prior to one or more emulsion layers sensitized to the red or green portion of the spectrum. Enhancement of speed-granularity relationships, blue to minus blue speed separation, silver utilization, and image sharpness can all be realized.

Abstract: An element is disclosed containing an emulsion comprised of silver iodide grains which are stable at room temperature and are bright yellow. In a preferred form the element is a photographic element.

Abstract: Moderate camera speed photographic elements for producing subtractive primary dye images are disclosed, including one emulsion layer comprised of silver bromide or bromoiodide grains having a mean diameter in the range of from 0.2 to 0.55 .mu.m including tabular grains having an aspect ratio of greater than 8:1 accounting for at least 50 percent of the total projected area of the grains in the emulsion layer and being positioned to receive imaging radiation prior to one or more blue recording emulsion layers. Enhancement of speed-granularity relationships, blue to minus blue speed separation, silver utilization, and image sharpness can all be realized.

Abstract: A radiographic element is disclosed having a support capable of transmitting blue light and, coated on each of two opposite major faces of said support, a silver halide emulsion layer capable of forming a latent image in response to exposure to blue light. Interposed between at least one of the latent image forming emulsion layers and the support is a blue absorbing silver iodide emulsion layer exhibiting at temperatures below 25.degree. C. an absorption transition wavelength that is bathochromically displaced by at least 20 nm as compared to the absorption transition wavelength of .beta. phase silver iodide.