Abstract: In a silver halide color photographic photo-sensitive material comprising a reflective support having thereon photographic structural layers comprising one or more photo-sensitive silver halide emulsion layers, pH of a coating of the silver halide color photographic photo-sensitive material ranges from 4.0 to 6.5. The photo-sensitive silver halide emulsion layer contains a mercapto heterocyclic compound and silver halide grains, each comprising silver chlorobromide or silver chloride and containing substantially no silver iodide. The silver halide grains are formed in the presence of a specific grain growth controlling agent. The silver halide grain contains a metal complex of Ir.

Abstract: A silver halide photographic element comprising a silver halide emulsion in reactive association with a compound of the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are each independently an aryl, alkyl or arylalkyl group; and wherein Z represents the atoms necessary to form a 5 or 6 membered heterocyclic ring and contains at least one atom selected from N, O, S, and Se; and methods of making same.

Abstract: Emulsions having an improved sensitivity/grain ratio are obtained when a silver halide emulsion containing up to 20 mol % of AgI is prepared by the precipitation of a silver halide emulsion A containing up to 100 mol % of AgI and the addition of a silver halide emulsion B which contains up to 40 mol % of AgI, has an average grain size of at most 0.25 .mu.m and is always more soluble in aqueous gelatine solution than emulsion A either due to its grain size or due to its iodide content, this being carried out in the presence of at least two compounds selected from imidazole, histidine (.alpha.-amino-.beta.

Abstract: Disclosed is a silver halide photographic light-sensitive material comprising an induced absorption peak intensity not less than 3.5 units and a long-lived light component intensity not less than 0.50 unit in the microwave photo conductivity measurement.A silver halide color photographic light-sensitive material is improved in a sensitivity and excellent in high intensity reciprocity law failure.

Abstract: A silver halide emulsion comprises at least one dispersion medium and silver halide grains having a silver iodide content of less than 5 mol %. At least 5% by number of the silver halide grains have at least one intrafacial epitaxy limited in the neighborhood of the corners of a major plane of the grain, and the thickness of the epitaxy is 0.1 .mu.m or less. A silver halide photographic light-sensitive material having at least one silver halide emulsion layer on a support, wherein this emulsion layer comprises the above emulsion, is also disclosed.

Abstract: There are disclosed an internal latent image type direct positive light-sensitive emulsions having improved spectral sensitization performance, and chemical sensitization performance, and color diffusion transfer photographic film units in which said emulsions are used. The emulsions are prepared by subjecting a silver halide grain, which forms an internal nucleus, to chemical sensitization, in the presence of an organic silver halide solvent, and adding a solid adsorbing agent, before finishing the formation of an outer shell silver halide phase, to remove a part or all of the silver halide solvent, wherein the emulsions may further contain a tabular silver halide grain having an average grain diameter of at least 0.3 .mu.m and a ratio of an average grain diameter to an average grain thickness of 2 or more, based on 50% or more of the total silver halide grains.

Abstract: An apparatus for producing a highly uniform mixture of a first solution with two or more solute-containing solutions comprises a reaction vessel with a porous member located therein. The porous member, whic may be a membrane or a plurality of fine tubes, is located within the vessel below the surface of the first solution. One or more solute-containing solutions are rapidly and uniformly introduced into the first solution through the porous member. The solute containing solutions diffuse rapidly into the first solution through the openings in the porous member, mixing evenly to produce a uniform composition.

Abstract: The invention concerns a process for obtaining emulsions of the core/shell type having a low fog level.The process consists of precipitating, by the double jet method, a photographic emulsion comprising core-shell silver halide grains, the concentrations of halides varying progressively during at least the formation of the core.Application to reversal or negative photographic products is disclosed.

Abstract: An internal latent image type positive silver halide emulsion has improved sensitivity reduction in low illuminance exposures. A color diffusion transfer light-sensitive material incorporates the emulsion and has reduced sensitivity reduction. The internal latent image type positive silver halide emulsion is prepared using a polymer having a repetitive unit derived from an ethylenically unsaturated monomer having at least one thioether structure on a side chain as a deflocculating agent to form silver halide grains and subjecting the grain surfaces to a chemical sensitization in the presence of a polymer having a repetitive unit represented by the following Formula (I): ##STR1## wherein R.sup.1 represents a hydrogen atom or a substituted or unsubstituted alkyl group and Q represents a group selected from the group consisting of groups represented by the following Formula (1) to Formula (4): ##STR2## wherein q represents an integer of 2 to 4; ##STR3## wherein R.sup.2 and R.sup.

Abstract: Photosensitive matting agents for photosensitive recording materials that are known can be prepared only at considerable expense. A much simplified process involves preparing a photosensitive matte material from photoinsensitive matting agent particles by incorporating the particles into the starting solutions for the silver halide precipitation. The invention is particularly useful in reprography and in medical diagnostics.

Abstract: A method for preparing silver halide emulsion which comprises silver halide grains containing an average iodide content of not more than 2 mol % comprising the steps of (i) preparing a seed emulsion containing silver halide seed grains, (ii) introducing the seed emulsion into a reaction vessel containing a hydrophilic colloid solution and (iii) introducing into the reaction vessel a silver salt and a halide salt to grow the silver halide grains from the seed grains, wherein in the step (iii), an emulsion containing silver iodide fine grains previously formed is supplied into the reaction vessel as a source of silver iodide; said seed grains are contained in an amount of 0.5 to 5.0% by volume in the hydrophilic colloid solution in the reaction vessel prior to introduction of silver and halide salts.

Abstract: Disclosed is a silver halide color photographic light-sensitive material comprising a support having thereon a red-sensitive layer, a green-sensitive layer and a blue-sensitive layer, wherein at least one of said sensitive layer contains light-sensitive silver halide grains having the dispersibility of not less than 85%.The silver halide color photographic light-sensitive material is improved in a high image quality and a pressure resistance.

Abstract: A grain growth process is disclosed for providing an ultrathin tabular grain emulsion in which the average equivalent circular diameter of tabular grains is increased. An aqueous dispersion is provided containing high bromide grains having an average thickness of less or equal to that of the ultrathin tabular grains to be produced, the dispersion having a pH in the range of from 2 to 8 and a limited stoichiometric excess of bromide ions. An 8-hydroxyquinoline that contains at least one iodo substituent is introduced into the dispersing medium as a grain growth modifier. The aqueous dispersion containing the iodo-8-hydroxyquinoline grain growth modifier is held at 40.degree. C. or a convenient higher temperature until greater than 50 percent of total grain projected area is accounted for by ultrathin tabular grains having {111} major faces of a higher average equivalent circular diameter than the starting grains and an average aspect ratio of at least 5.

Abstract: A silver halide photographic emulsion, in which silver halide grains have been formed while iodide ions are rapidly being generated in a reactor vessel to form a silver iodide-containing region in the silver halide grains, and the silver halide grains have been spectrally sensitized by a sensitizing dye represented by the following formula (I): ##STR1## wherein Z.sub.1 and Z.sub.2.sup.- represent non-metallic atom group which form a 5- or 6-membered heterocyclic ring having nitrogen atom and carbon atom in the ring, R.sub.3 and R.sub.4 represent alkyl groups, X.sub.1.sup.- represents an anion, and p represents 1 or 2.

Abstract: A silver halide photographic element comprising a silver halide emulsion which is greater than 50 mole % silver chloride, said emulsion being in reactive association with a sulfur donating compound and a phosphine compound represented by Formulae I and II, and polymers having a repeating unit derived from the compounds of Formula I,Formula (I) R.sup.18 R.sup.19 R.sup.20 PFormula (II) R.sup.21 R.sup.22 P--A--PR.sup.23 R.sup.24wherein R.sup.18, R.sup.19, R.sup.20, R.sup.21, R.sup.22, R.sup.23, and R.sup.24 are independently alkyl, or aryl groups, or R.sup.18, R.sup.19, R.sup.20, R.sup.21, R.sup.22, R.sup.23, and R.sup.24 may combine to form a 5 or 6-membered ring , and wherein A is a divalent carbon linking group, and a method of making the silver chloride emulsion.

Abstract: The present invention relates to water soluble photographic sensitivity increasing alkynylamine compounds. It also relates to photographic elements containing such compounds.

Abstract: An improved preparation of high chloride {100} tabular grain emulsions that relies on iodide ions to produce tabular grain growth is disclosed. By delaying iodide ion introduction until after the initiation of grain nucleation the proportion of total grain projected area accounted for by high chloride {100} tabular grains is increased. The projected areas of the {100} tabular grains can exceed 95 percent of total grain projected area.

Abstract: A silver halide light-sensitive photographic material comprising a support having a silver halide emulsion layer in which an induced absorption peak (a) obtained in a microwave photoconductivity measurement and a peak (b) obtained from the material with a pressure treatment under a prescribed condition satisfies a relation of b/a.gtoreq.0.85, is disclosed. The material shows less pressure desensitizations and high sensitivities.

Abstract: A silver halide photographic light-sensitive material comprising a support having thereon a silver halide emulsion layer containing a silver halide emulsion comprising silver halide grains, which is prepared by a process comprising(i) forming the silver halide emulsion by mixing a silver salt and a halide salt in a dispersion medium,(ii) subjecting the emulsion formed to washing to remove water-soluble salts, and then(iii) carrying out chemical sensitization of the emulsion wherein in (ii), the washing is carried out by coagulating the emulsion by a gelatin coagulant selected from of a modified gelatin or a polymeric coagulant represented by the following formula [I]; and in (iii), iodide-containing silver halide fine grains are added at a time during the course of the chemical sensitization, ##STR1##

Abstract: A grain growth process is disclosed for providing an ultrathin tabular grain emulsion in which the equivalent circular diameter of tabular grains is increased. An aqueous dispersion is provided containing high bromide seed grains having an average thickness of less or equal to that of the ultrathin tabular grains to be produced, the dispersion having a pH in the range of from 4.6 to 9.0 and a limited stoichiometric excess of bromide ions. An aminopyrimidine grain growth modifier containing mutually independent amino substituents, the 4 and 6 ring position substituents being hydroamino substituents, is introduced into the dispersing medium. The aqueous dispersion containing the aminopyrimidine grain growth modifier is held at room temperature or a convenient higher temperature until greater than 50 percent of total grain projected area is accounted for by ultrathin tabular grains having {111} major faces of a higher average equivalent circular diameter than the seed grains.

Abstract: A grain growth process is disclosed for providing an ultrathin tabular grain emulsion in which the average equivalent circular diameter of tabular grains is increased. An aqueous dispersion is provided containing high bromide starting grains having an average thickness of less or equal to that of the ultrathin tabular grains to be produced, the dispersion having a pH in the range of from 1.5 to 8 and a limited stoichiometric excess of bromide ions. A phenol that is incapable of reducing the starting grains and that contains at least two iodo substituents is introduced into the dispersing medium as a grain growth modifier. The aqueous dispersion containing the phenol grain growth modifier is held at 40.degree. C. or a convenient higher temperature until greater than 50 percent of total grain projected area is accounted for by ultrathin tabular grains having {111} major faces of a higher average equivalent circular diameter than the starting grains and an average aspect ratio of at least 5.

Abstract: An apparatus for producing amorphous particle dispersions of high-melting microcrystalline solids in a continuous process. The apparatus comprises a pump, two heat exchangers, a back-pressure valve and conduits connecting them, whereby it is possible to make aqueous dispersions of particles whose melting points are above 100.degree. C.

Abstract: A process is disclosed of preparing a high chloride {111} tabular grain emulsion. Tabular grains are formed having {111} major faces, containing at least 50 mole percent chloride and less than 5 mole percent iodide, based on silver, and accounting for at least 50 percent of total grain projected area by introducing silver ion into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions with respect to silver ions and a phenol that is incapable of reducing silver chloride and has at least two iodo substituents, which acts as a grain growth modifier.

Abstract: The present invention provides a photographic element comprising a support having thereon a silver halide emulsion layer. The emulsion layer contains an organic compound having a thiosulfonic acid substituent, an organic compound having a sulfinic acid substituent, and an amine borane.

Abstract: A light-sensitive silver halide photographic material is disclosed. The light-sensitive material comprises a support having thereon a silver halide emulsion layer, and the silver halide emulsion layer comprises silver halide grains having a silver chloride content of not less than 95 mol %. The emulsion is optically sensitized by addition of a dispersion of an optical sensitizer comprising a medium and particles of the dye dispersed in the medium. The ratio of silver to gelatin (Ag/Gel) in the emulsion at the time of addition of the dispersion of the dye is 2 to 8.5.

Abstract: A silver halide photographic emulsion comprises silver halide grains to which an iridium compound was added during a preparation process. At least 5% by number of said silver halide grains have at least one intrafacial epitaxy limited in the neighborhood of the corners of a major plane of the grain, and the thickness of said epitaxy is 0.1 .mu.m or less.

Abstract: The present invention provides a photographic element comprising a support having thereon a silver halide emulsion layer. The emulsion layer contains an organic compound having a thiosulfonic acid substituent, an organic compound having a sulfinic acid substituent, and an alkynylamine.

Abstract: A silver halide photographic material having at least one light-sensitive silver halide emulsion layer coated on a support, wherein the silver halide emulsion layer contains silver chlorobromide grains comprising silver chlorobromide containing 90 mol % or more of silver chloride, having at least one region in which the silver bromide content is high at the vicinity of the corner of the grains, and with not more than 15 mol % of average silver bromide content at the surface of the grains. A method producing the silver halide photographic materials is also disclosed.

Abstract: A process is disclosed of preparing a high chloride {111} tabular grain emulsion. Tabular grains are formed having {111} major faces, containing at least 50 mole percent chloride and less than 5 mole percent iodide, based on silver, and accounting for at least 50 percent of total grain projected area by introducing silver ion into a gelatino-peptizer dispersing medium containing a stoichiometric excess of chloride ions with respect to silver ions and an iodo-substituted 8-hydroxyquinoline, which acts as a grain growth modifier.

Abstract: Disclosed are photographic elements comprising a silver halide emulsion having incorporated therein silver halide grains, wherein the grains are essentially tabular in morphology and have at least two parallel {100} major faces and substantially equivalent {111} corner faces or substantially equivalent {110} corner faces or substantially equivalent {110} side faces.

Abstract: The invention describes silver halide packet emulsion grains or crystals that are conventionally precipitated using gelatin of a given isoelectric pH, surrounded by a layer of gelatin-grafted-polymer particles wherein the grafted gelatin has a different isoelectric pH and the said gelatin-grafted-polymer particles are optionally chemically bonded to the gelatin surrounding the silver halide microcrystals. Such packet emulsions can form the basis for a mixed-packet color photographic system.

Abstract: A silver halide photographic light-sensitive material comprises, on a support, at least one negative silver halide emulsion layer containing silver halide grains which are subjected to selenium sensitization, have at least one peak value in internal sensitivity speck numbers in a distribution of sensitivity specks, the peak value being present at a depth of 2 nm to less than 50 nm from the surface of the grains, and have an average aspect ratio of less than 8.

Abstract: A radiation sensitive emulsion is disclosed that improves the light absorption of high chloride tabular grain emulsions in the longer wavelength half of the blue spectrum. The tabular grains each have a tabular substrate portion containing at least 50 mole percent chloride, based on silver, bounded by {100} major faces and a portion deposited on the substrate containing a silver salt exhibiting a higher solubility than silver iodide and a higher absorption of blue light at wavelengths longer than 450 nm than silver iodide.

Abstract: A method for preparing a silver halide emulsion. The method comprises supplying bromine and/or bromine ion at a plurality of processing stages to silver halide host grains to form a phase rich in silver bromide in the vicinity of the apexes of the grains. The host grains are substantially of a cube or octahedron and have a silver chloride content of about 95 mole % or more, and a silver bromide content of about 0 to about 5 mole %. The bromine and/or bromine ion is supplied at the plurality of stages by adding and mixing in a reaction vessel at least one of (i) a water soluble bromine compound, (ii) silver halide grains having a smaller average grain size and a larger silver bromide content than the silver halide host grains, and (iii) a bromine or bromine ion precursor represented by a certain formula (S). In at least one stage of the plurality of processing stages the bromine and/or bromine ion is supplied when the formation of the silver bromide-rich phase is at least 80% complete in the previous stage.

Abstract: The invention provides a process for incorporating iridium into silver chloride or silver chlorobromide emulsions containing 90% or more chloride which comprises addition of an iridium salt along with or followed by the addition of bromide to the emulsion, after completion of the precipitation stage of emulsion manufacture. The invention also encompasses the formed emulsions and photographic elements comprising the emulsions.

Abstract: A silver halide photographic light-sensitive material comprising at least one light-sensitive silver halide emulsion layer formed on a support. The emulsion layer containing at least one silver halide emulsion which comprises regular-crystal grains having a silver halide phase containing silver iodide. The silver halide phase has been formed while iodide ions are rapidly being generated.

Abstract: A radiation sensitive emulsion is disclosed containing a silver halide grain population comprised of at least 50 mole percent chloride, based on silver, in which greater than 50 percent of the total grain projected area is accounted for by ultrathin tabular grains containing a 7-azaindole type compound.

Abstract: The present invention relates to a photographic element comprising a silver halide emulsion, the emulsion comprising silver halide grains which contain an alkynylamine dopant. The presence of the alkynylamine dopant imparts to the photographic element the advantageous characteristic of increased sensitivity.

Abstract: A process for preparing a thin tabular grain silver halide emulsion comprised of silver halide grains which have a halide content of at least 50 mole percent bromide, wherein tabular grains of less than 0.15 micrometers in thickness and having an aspect ratio of greater than 8 account for greater than 50 percent of the total grain projected area, comprises the steps of nucleating the silver halide grains with a gelatino-peptizer or with the use of certain synthetic polymers that serve as effective nucleation peptizers and then growing the silver halide grains with the use of either a gelatino-peptizer or certain synthetic polymers that serve as effective growth peptizers.

Abstract: Disclosed are photographic elements comprising a silver halide emulsion having incorporated therein a hollow silver halide grain, wherein the hollow silver halide grain internally contains at least two distinct voids. Also disclosed is a process for making photographic emulsions containing grains that internally contain at least two distinct voids.

Abstract: A silver halide emulsion comprises silver halide grains having a silver chloride content of not less than 10 mol % and a silver bromide content of not less than 0.1 mol % the silver halide grains being formed in the presence of at least one of compounds represented by the following Formula I:Formula IY.sub.n1 MBr.sub.n2 X.sub.n3wherein M represents an ion selected from the group consisting of rhenium, ruthenium, osmium, platinum, palladium, and iridium ion; Y represents a cation; X represents a ligand coordinating M; n.sub.1 represents an integer of 0 to 3; and n.sub.2 and n.sub.3 each represent an integer, provided that n.sub.2 .gtoreq.n.sub.3 and n.sub.2 +n.sub.3 =4 or 6.

Abstract: A process for preparing a thin tabular grain silver halide emulsion comprised of silver halide grains which have a halide content of at least 50 mole percent bromide, wherein tabular grains of less than 0.15 micrometers in thickness and having an aspect ratio of greater than 8 account for greater than 50 percent of the total grain projected area, comprises the steps of nucleating the silver halide grains with a gelatino-peptizer or with the use of certain synthetic polymers that serve as effective nucleation peptizers and then growing the silver halide grains with the use of either a gelatino-peptizer or certain synthetic polymers that serve as effective growth peptizers.

Abstract: A silver halide photographic light-sensitive material in which silver halide grains contain rhodium salt and not more than 4 mol % of silver iodide, and at least one of spectral sensitizing dyes represented by formula 1 is added before the commencement of chemical ripening, is disclosed. ##STR1## Z.sub.1 and Z.sub.2 represent ring forming groups with non-metallic atoms i.e. a pyrroline, thiazoline, thiazole, benzothiazole, naphthothiazole, selenazole, benzoselenazole, naphthoselenazole, oxazole, benzooxazole, naphthooxazole, imidazole, benzimidazole or a pyridine group. Each group is unsubstituted or substituted with a halogen atom, a lower alkyl group, a lower alkoxy group or a phenyl group; R.sub.1 and R.sub.2 each represent a lower alkyl group, a hydroxyalkyl group, a carboxylalkyl group or a sulfoalkyl group; R.sub.3, when n.sub.3 is 1, represents a lower alkyl group or a hydrogen atom, while, when n.sub.3 is zero, represents a hydrogen atom; n.sub.1 and n.sub.2 each is 0 or 1; n.sub.3 is 0 or 1; X.sup.

Abstract: Disclosed is a novel process for the preparation of tabular silver halide grains having parallel twinning planes which comprises the steps of:1) supplying an aqueous solution of a water-soluble silver salt, an aqueous solution of a water-soluble halide and an aqueous solution of a protective colloid into a mixing machine provided external to a reaction vessel where they are mixed to form nuclear grains; and2) introducing the nuclear grains into a ripening vessel comprising a pipe where they are ripened at an elevated temperature.

Abstract: A silver halide photographic light-sensitive emulsion is disclosed. The emulsion comprises silver halide grains formed under a condition in which fine grains of silver halide are supplied into the protective colloid solution, in which the silver halide grains are formed, in a period in the course of formation of the grains, andthe sum of projection area of tabular grains each having a aspect ratio larger than 1.2 accounts for lower than 50% of the total projection area of the whole silver halide grains of the emulsion, and the tabular grains have an average aspect ratio is more than 1.2 and less than 5.0 and an average grain size of not larger than 0.6 .mu.m.

Abstract: The invention provides a method of nucleating silver halide particles wherein said nucleation is carried out in the presence of acid processed ossein (APO) gelatin or chain-extended acid processed ossein (CE-APO) gelatin and the composition formed therefrom.

Abstract: A photographic silver halide emulsion comprised of silver halide grains containing chloride, bromide and iodide ions in which the molar ratio of bromide ions to chloride ions ranges from 9:1 to 1:1 and the proportion of iodide has been increased.

Abstract: A method for preparing a silver iodobromide emulsion comprising silver iodobromide grains containing an average silver iodide content of 2 mol % or less is provided, wherein the silver iodobromide emulsion is prepared by incorporating simultaneously a silver salt solution and a solution of bromide and iodide salts into a hydrophilic colloid solution containing silver halide seed grains to grow the silver iodobromide grains from the seed grains, wherein the total volume of the solutions of the silver salt and the bromide and iodide salts is within a range of 2 to 10 times the volume of the hydrophilic colloid solution containing the seed grains in an amount of 0.5 to 5.0% by volume.

Abstract: A process for controlling the silver halide grain-to-grain distribution of a variable contrast dye in a light sensitive silver halide emulsion layer of a variable contrast photographic element, and thereby adjusting the low contrast characteristic curve of the element, is disclosed comprising the process steps of adding a green variable contrast sensitizing dye of the following formula (I) to a silver halide emulsion for a variable contrast photographic element, adding a blue sensitizing dye of the following formula (II) to the same silver halide emulsion, and coating the emulsion on a support. In the process, the green and blue sensitizing dyes are added to the emulsion at substantially the same time, and the green dye is added in an amount less than that required to impart maximum sensitivity to all of the silver halide in the emulsion. ##STR1## In formula (I), R.sup.1, R.sup.2, R.sup.6 and R.sup.

Abstract: A silver halide photographic light-sensitive material comprising a support bearing on both sides thereof a silver halide emulsion layer containing a silver halide emulsion comprising monodispersed and spectrally-sensitized silver halide tabular grains having an average aspect ratio of grain diameter to grain thickness of from not less than 2 to less than 8 and accounting for at least 70% of the total projected area of the grains contained in the silver halide emulsion and a method of preparing the silver halide emulsion are disclosed, wherein the silver halide emulsion is chemically sensitized in the presence of iodide-containing silver halide fine grains, thus chemically-sensitized emulsion having a value of 100 mV or less with respect to a silver electrode potential at 50.degree. C.