Abstract: A lithium air battery including an anode for intercalating/deintercalating lithium ions; a cathode having oxygen as a cathode active material, a lithium ion conductive solid electrolyte membrane disposed between the anode and the cathode; and an electrolyte, wherein the electrolyte is disposed between the lithium ion conductive solid electrolyte membrane and the cathode, and wherein the electrolyte includes at least one compound selected from a compound represented by Formula 1 and a copolymer including a repeating unit represented by Formula 2 as an additive: wherein in Formulae 1 and 2, groups CY1, CY2, a, b, c, b, R1 to R18, and variables t, u, and v are defined in the specification.

Abstract: Disclosed is a silver halide photographic light-sensitive material comprising at least one silver halide emulsion layer on a support, which contains a fluorine compound having two or more fluorinated alkyl groups having two or more carbon atoms and 11 or less fluorine atoms and having at least one of an anionic hydrophilic group and a nonionic hydrophilic group, and has a characteristic curve drawn in orthogonal coordinates of logarithm of light exposure (x-axis) and optical density (y-axis) using equal unit lengths for the both axes, on which gamma is 5.0 or more for the optical density range of 0.3-3.0. There is provided a silver halide photographic light-sensitive material that provides high sensitivity, high contrast, favorable half tone dot quality and superior storage stability.

Abstract: Disclosed is a silver halide photographic light-sensitive material having a layer containing a compound of the following formula and a fluorine compound, and has a gamma of 5.0 or more for the optical density range of 0.3 to 3.0: wherein R1 is alkyl or alkenyl, R2 are H, alkyl, alkenyl, aralkyl or aryl, l1 is 1–10, m1 is 1–30, n1 is 0–4, a is 0 or 1, and Z1 is OSO3M or SO3M where M is cation.

Abstract: Polyether polymers providing a backbone substituted at intervals with electron stabilizing groups containing electron withdrawing groups are described. The polymers capture electrons and are electronegative. The polymers act to solvate alkali metals so that electrons are withdrawn from the alkali metal into the polymer. The polymer compositions are conductive under certain conditions and are magnetic. The compositions are useful in electronic applications.

Abstract: Disclosed is a silver halide photographic material containing a non ionic fluorine compound of formula (1) and an anionic fluorine compound of formula (2). The silver halide photographic material has good static resistance and excellent anti static properties. (1): C4F9—CH2CH(OH)CH2—(OCH2CH2)m—OCnH2n+1 wherein m is 15–40; n is 8–24; (2): wherein R11–R13 are H or substitutent; n1 and n2 are 4–8; L11 and L12 are alkylene, alkyleneoxy, or linking group; m11 is 0–1; M1 is cation.

Abstract: A multicolor image-forming material comprising: an image-receiving sheet comprising a support and an image-receiving layer; and at least four thermal transfer sheets each comprising a support, a light-to-heat converting layer and an image-forming layer, and each having a different color, wherein an image is formed by the method comprising the steps of: superposing each one of the at least four thermal transfer sheets on the image-receiving sheet to be in a state of the image-forming layer being in contact with the image-receiving layer; and irradiating the thermal transfer sheet with a laser beam to transfer an image in an area of the image-forming layer subjected to irradiation onto the image-receiving layer, and at least one layer selected from layers comprised in the image-receiving sheet and the at least four thermal transfer sheets comprises a fluorine-series surface active agent which is a homopolymer comprising a polymerizable monomer represented by the formula (1) and having a weight average molecular

Abstract: A silver halide photographic light-sensitive material having one or more layers including at least one light-sensitive silver halide emulsion layer on a support, wherein any of the layers formed on the support contains a compound represented by the following formula (1) and a fluorine-containing surfactant (in the formula (1), R1 represents an alkyl group or alkenyl group having 6-25 carbon atoms, ml represents an integer of 0-30, n1 represents an integer of 0-4, a represents 0 or 1, and Z1 represents OSO3M or SO3M, where M represents a cation). There is provided a silver halide photographic light-sensitive material that shows superior antistatic property and can be stably produced.

Abstract: A photographic material, comprising a support having thereon at least one yellow, cyan, and magenta color-forming light-sensitive silver halide emulsion layer, and at least one light-insensitive non-color forming hydrophilic colloid layer. At least one cyan emulsion layer contains a cyan dye-forming coupler [C-1] and at least one light-insensitive colloid layer exists between the support and a light-sensitive emulsion layer most adjacent thereto. Also, a photographic material, comprising a transparent support having thereon at least three kinds of light-sensitive hydrophilic colloid layers each containing any of yellow, magenta and cyan dye-forming couplers and containing silver halide grains different from each other in color sensitivity, and at least one light-insensitive hydrophilic colloid layer. Any layer contains a compound [XI], at least one colloid layer contains a solid fine particle dispersion of a dye [I], and said material has a film pH from 4.6 to 6.4.

Abstract: A heat-sensitive recording material includes a support having disposed thereon a heat-sensitive recording layer and a protective layer. The heat-sensitive recording layer contains at least two components that react to develop color by imagewise heating. At least one layer contains a compound represented by the following general formula (I). In the general formula (I), R represents a hydrophobic group or a hydrophobic polymer, and n represents an integer.

Abstract: A multicolor image-forming material comprising: an image-receiving sheet comprising a support and an image-receiving layer; and at least four thermal transfer sheets each comprising a support, a light-to-heat converting layer and an image-forming layer, and each having a different color, wherein an image is formed by the method comprising the steps of: superposing each one of the at least four thermal transfer sheets on the image-receiving sheet to be in a state of the image-forming layer being in contact with the image-receiving layer; and irradiating the thermal transfer sheet with a laser beam to transfer an image in an area of the image-forming layer subjected to irradiation onto the image-receiving layer, and at least one layer selected from layers comprised in the image-receiving sheet and the at least four thermal transfer sheets comprises a fluorine-series surface active agent which is a homopolymer comprising a polymerizable monomer represented by the formula (1) and having a weight average molecular

Abstract: A multicolor image forming material comprising: an image-receiving sheet comprising an image-receiving layer; and at least four thermal transfer sheets differing in color each comprising a support, a light-to-heat conversion layer and an image-forming layer, wherein the image forming material is used for recording a multicolor image by superposing the image-forming layer of each thermal transfer sheet and the image-receiving layer to face each other, irradiating laser light and transferring a region irradiated with the laser light of the image-forming layer onto the image-receiving layer, and at least one layer selected from the image-receiving layer and the image-forming layers comprises, as a fluorine-containing surfactant, a copolymer (I) comprising following repeating units (A), (B) and (C) as defined herein.

Abstract: An information recording material which contains a fluorine-containing nonionic surfactant, 1.5×10−5 mol/m2 or more of a polyvalent metal salt, and an anionic surfactant capable of forming a sparingly soluble salt in an aqueous solution with the polyvalent metal, in the outermost layer on a support on the side of an information recording layer. The information recording material is less in static charge and improved in surface deficiencies due to coating.

Abstract: The invention relates to a photographic element comprising a reflection support and an overcoat layer wherein said overcoat layer comprises hydrophilic binder and lubricant, said lubricant has a particle mean diameter of greater than 1 &mgr;m and the volume of particles of lubricant below 1 &mgr;m is less than 5% of said total volume of lubricant.

Abstract: The invention relates to a photographic element comprising a base and hydrophillic colloid layers comprising at least one layer comprising photosensitive silver halide, wherein said hydrophilic colloid imaging layers further comprise a flexibilizer agent and said flexibilizer agent has a logP of greater than −1.2.

Abstract: A hydrophilic colloid composition having hydrophobic material dispersed therein and comprising an anionic surface active agent further comprises a cationic surface active agent in an amount sufficient to reduce the viscosity of the composition, the cationic surface active agent comprising a hydrophobic moiety, a non-ionic hydrophilic moiety and a cationic hydrophilic moiety.

Abstract: A silver halide photographic emulsion comprising grains, wherein 70% or more of the total projected area of the grains is occupied by silver halide grains each meeting requirements (a) to (d) below

Abstract: A radiation-sensitive emulsion comprised of an aqueous dispersing medium and a coprecipitated grain population including tabular grains containing greater than 50 mole percent bromide, based on silver, having {111} major faces, and accounting for greater than 90 percent of total grain projected area, wherein said dispersing medium is comprised of (a) a gelatin which has been modified to convert at least one carboxylic acid group thereof to a group that does not exhibit pH-dependent ionization within the pH range from 4.0 to 7.0, and (b) a polyalkylene oxide block copolymer surfactant.

Abstract: A photographic film comprising a base layer and at least one emulsion layer, the emulsion layer having a melting temperature that is within 4 degrees centigrade of the incubation temperature used in an accelerated core-set test.

Abstract: A silver halide photographic light-sensitive material that has at least one silver halide emulsion layer on a support, the light-sensitive material containing a surfactant represented by the following formula (F), and having the characteristic curve that a gamma in the range of an optical density from 0.3 to 3.0 is 5.0 or more, on the characteristic curve shown in a rectangular coordinate where a logarithmic exposure amount (the x axis) and an optical density (the y axis) are indicated according to the same unit length; [Rf—(Rc)n]m—Z  formula (F) wherein Rf represents a perfluoroalkyl group, Rc represents an alkylene group, Z represents a group having an anionic group, cationic group, amphoteric ionic group, or nonionic polar group, n is an integer of 0 or 1, and m is an integer of 1 to 3.

Abstract: A photographic film comprising a base layer and at least one emulsion layer, the emulsion layer having a melting temperature that is within 4 degrees centigrade of the incubation temperature used in an accelerated core-set test.

Abstract: A black and white graphic arts film comprising a support having thereon at least one emulsion layer, said emulsion layer comprising:

Abstract: A process for forming a silver halide photographic emulsion is disclosed comprising precipitating silver halide grains in an aqueous dispersing medium to which has been added silver and halide salt solutions while agitating the dispersing medium, wherein the precipitation is done in the presence of an antifoamant compound of the formula RO(CH2CH2O)nH wherein R represents an alkyl or alkenyl group containing 10 to 25 carbon atoms, or mixtures thereof, and n represents a mean value of from 2 to 4. The antifoamant material may be delivered to the aqueous dispersing medium as a small particle dispersion, made with the same peptizer used for manufacturing the emulsion or another stabilizer. A further embodiment of the invention is directed towards a silver halide photographic material comprising a support upon which is coated at least one light sensitive silver halide emulsion layer, comprising a silver halide emulsion precipitated in accordance with the described process.

Abstract: A silver halide coated photographic material is disclosed comprising sensitized silver bromide or silver bromoiodide tabular grains having an average thickness of less than 0.30 &mgr;m, in at least one light-sensitive layer and which is characterised in that it further contains in the said light-sensitive layer and/or at least one non-light sensitive layer at least one polyoxyethylene compound comprising from about 20 to 100 mole percent recurring units of the formula (Ia) and 80 to 0 mole % recurring units of the formula and wherein R represents an aliphatic, aromatic, or heterocyclic group, and X represents a halogen.

Abstract: A photographic polyester film and a manufacturing method therefor. The photographic polyester film includes a polyester base film, a primer layer formed of polyurethane resin on at least one surface of the polyester base film, and a subbing layer formed of a hydrophillic polymer on at least one surface of the primer layer. Also, a photosensitive layer may be stacked on the subbing layer. The photographic polymer film having the primer layer, the subbing layer and the photosensitive layer exhibits excellent interlayer adhesiveness between the hydrophobic polyester base film and the hydrophilic sensitive layer.

Abstract: A photothermographic recording material comprising a support and a photo-addressable thermally developable element comprising photosensitive silver halide in catalytic association with a substantially light-insensitive organic silver salt, an organic reducing agent for the substantially light-insensitive organic silver salt in thermal working relationship therewith and a water-soluble or water-dispersible binder, characterized in that the substantially light-insensitive organic silver salt is a silver salt of an organic carboxylic acid, the photo-addressable thermally developable element further comprises a non-ionic or anionic surfactant and the photo-addressable thermally developable element is coatable from an aqueous medium and is capable of producing stable images without a wet-processing step; a process for producing the photothermographic recording material and a photothermographic recording process therefor.

Abstract: The present invention is a method for stabilizing a photographic coating melt. The photographic melt includes an aqueous medium and a dispersed liquid organic phase containing an ultraviolet ray absorbing compound, and an emulsion containing silver halide particles having an average equivalent circular diameter of from 0.03 to 0.10 microns. The photographically useful ultraviolet ray absorber compound is soluble in a liquid organic phase and substantially insoluble in water. The method includes the step of adding to the emulsion containing silver halide particles a sufficient amount of surfactant to passify surfaces of the silver halide particles. The present invention is also a method of preparing a photographic coating melt. A dispersion is prepared which includes an aqueous medium, a dispersed liquid organic phase and an ultraviolet ray absorber compound wherein the ultraviolet ray absorber compound is soluble in the dispersed liquid organic phase and substantially insoluble in water.

Abstract: There is disclosed a silver halide emulsion that comprises at least a dispersion medium and silver halide grains, wherein 60% or more of the total projected area of the silver halide grains is occupied by tabular grains having an epitaxial junction, which grains each have a {100} face as a main plane and an aspect ratio (diameter/thickness ratio) of from 2.

Abstract: Provided is a photographic support which is excellent in mechanical strength and is less liable to get into roll set curl and which is excellent in cutting property and flatness, and a photographic material using the same. The support for photographic material comprises a polyester film, wherein the polyester film comprises two kinds of polyester resins, each has intrinsic viscosity of 0.2-1.2, and a difference in the intrinsic viscosity between the polyester resins is 0.1-1.0.

Abstract: A method has been described of preparing a photosensitive emulsion comprising tabular silver halide grains rich in silver bromide, having {100} major faces and an aspect ratio more than 1.5, wherein at least 50% of the projected area of all grains is provided by said {100} tabular grains, said method comprising the step of running in a reaction vessel an aqueous silver salt solution and an aqueous alkali halide solution rich in alkali bromide, characterized in that before starting running said reaction vessel comprises in an aqueous solution of gelatin an amount of amino-modified polyvinyl alcohol as an aqueous soluble polymer.

Abstract: A silver halide emulsion is described, which comprises at least a dispersion medium and silver halide grains, wherein from 40 to 100% of the total projected area of the entire silver halide grains are occupied by tabular grains having a thickness of from 0.01 to 0.50 .mu.m, an aspect ratio (diameter/thickness) of from 1.6 to 500, and main planes of {100} faces, and the aspect ratio of a right angled parallelogram surrounded by edge sides of {100} face of the tabular grains or a right angled parallelogram formed by extending the edge sides (long side length/short side length) is from 1 to 8, and the tabular grains are tabular grains formed by the adsorption of compound A.sup.0 represented by formula (Z.sup.1), (Z.sup.2), (Z.sup.3) or (Z.sup.4) onto silver halide grains:B.sup.1 --S--B.sup.2 (Z.sup.1)B.sup.1 --S(O)--B.sup.2 (Z.sup.2)B.sup.1 --S(O.sub.2)--B.sup.2 (Z.sup.3)B.sup.1 --S.sup.+ (R.sup.0)--B.sup.2 .multidot.Y.sub.0.sup.-(Z.sup.4)wherein B.sup.

Abstract: A process of preparing a radiation-sensitive silver halide emulsion is disclosed in which a polyalkylene oxide block copolymer surfactant is employed. Dispersion of the polyalkylene oxide block copolymer surfactant in the aqueous dispersing medium is increased by the inclusion of an auxiliary surfactant. The auxiliary surfactants are selected from among those that, in the form of an aqueous solution containing 10 percent by weight of the auxiliary surfactant based on total weight of the aqueous solution, is miscible in all proportions with at least one of water and the polyalkylene oxide block copolymer surfactant.

Abstract: A support for an imaging element is described, which support comprises a polyester polymeric film having coated thereon a subbing layer comprising gelatin and a multi-hydric organic compound having at least three hydroxyl groups, which gelatin subbing layer coated support has been subjected to a heat treatment to reduce the core-set curling tendency of the polymeric film. Imaging elements for use in an image-forming process is also described, which elements comprise a gelatin subbing layer coated polyester polymeric film support as described above, and an image-forming layer coated on the subbed support. A method for forming a heat-tempered, gelatin-subbed support for an imaging element is also described, comprising coating a subbing layer comprising gelatin and a multi-hydric organic compound having at least three hydroxyl groups on a polyester polymeric film, and subjected the coated film to heat treatment to reduce the core-set curling tendency of the polymeric film.

Abstract: The present invention describes an aqueous coating composition useful in an imaging element which includes polymeric matte beads, an ionic surfactant and a dispersant selected from the group of polymers represented by the generic structures shown below ##STR1## wherein A comprises up to 150 repeat units of ethylene oxide, B comprises 3 to about 100 repeat units of a propylene oxide or higher alkylene oxide or combinations thereof, Q represents a multivalent linking group, x represents 1 or 2 and z represents 1 or 2.

Abstract: A method for producing a light-sensitive silver halide photographic emulsion is disclosed, comprising (a) a step of forming silver halide grain nuclei containing twin grain nuclei in a dispersion medium solution, (b) a step of ripening said grain nuclei to preferentially remain tabular grain nuclei, and (c) a step of growing said tabular grain nuclei into tabular grains to form a tabular silver halide grain, wherein in step (a), a silver halide nucleus having a chloride content of 10 mol % or more based on the amount of silver contained in the nucleus is formed, and the tabular silver halide grain obtained through steps (a), (b) and (c) has a Br content of 50 mol % or more based on the total silver amount.

Abstract: A method has been described for preparing a gelatinous emulsion having grains rich in silver choride, wherein at least 70%, and more preferred 90%, of the total projected area of all grains is provided by {111} tabular grains having an average aspect ratio of more than 2:1, an average equivalent circular diameter of at least 0.3 .mu.m and an average thickness of from 0.05 to 0.25 .mu.

Abstract: A method is disclosed for washing silver halide photographic emulsions, including desalting and/or concentrating, based on depletion phase separation mechanism, wherein phase separation is effected by the addition of water-soluble non-interactive and non-adsorbing carboxyl polymers. The process involves the separation of the supernatant fluid, containing the undesirable water soluble salts and the added phase separating agents, from the washed and condensed silver halide phase for desalting and redispersion of the latter.

Abstract: A method is disclosed for washing silver halide photographic emulsions, including desalting and/or concentrating, based on depletion phase separation mechanism, wherein phase separation is effected by the addition of water-soluble non-interactive and non-adsorbing non-ionic polymers or non-ionic surfactant micelles. The process involves the separation of the supernatant fluid, containing the undesirable water-soluble salts and the added phase separating agents, from the washed and condensed silver halide phase and redispersion of the latter.

Abstract: A thermally processable imaging element is disclosed having a protective coat overlying at least one thermographic or photothermographic imaging layer containing an organic silver salt and a thermally activated reducing agent for silver ion. The protective coat includes a film-forming binder comprised of a water dispersible polymer containing hydroxy pendant groups and, to reduce low density spots visible after thermal processing, a combination of anionic, non-ionic and fluorocarbon moiety containing surfactants satisfying formula defined selection criteria.

Abstract: A photographic element is disclosed comprising a support bearing at least one light sensitive silver halide emulsion layer comprising a dispersion of a dye-forming coupler and a water-insoluble polymer, wherein the polymer has a glass transition temperature of less than 75.degree. C. and is formed from at least 30 wt % monomer units which provide the polymer with functional groups that are hydrogen bond donors. The combination of such relatively low T.sub.g polymers with couplers in photographic elements leads to both decreased pressure sensitivity and improved image-dye light stability, as well as a decreased tendency toward dye smear or thermal induced change. The advantages of the invention are particularly useful for yellow coupler dispersions used in photographic color paper elements on reflective supports, although they will also be useful for motion picture print film and other projection or display films on transparent or diffuse supports.

Abstract: A process of preparing a radiation-sensitive silver halide emulsion is disclosed in which the silver halide grains form dispersed clumps. A population of fine silver halide grains is precipitated at higher concentrations than previously taught for preparing this type of an emulsion by employing a peptizer limited in amount, limited in methionine content, or both. Following formation of the grains, they are aggregated into clumps by the addition of a surfactant, optionally assisted by the adding iodide, increasing pH or both. The grain clumps are stabilized against further aggregation by adding a high methionine peptizer and optionally assisted by the precipitation of additional silver halide.

Abstract: The present invention concerns a photographic material comprising, in addition to the conventional light-sensitive silver halide layers, a protective top layer.According to the invention, the protective layer comprises, in combination, a surface-active fluorinated polyether and a vinyl polymer.This protective top layer enables the appearance of marks during photographic processing to be prevented without modifying the sensitometric results.

Abstract: A silver halide photographic light-sensitive material is disclosed. The light-sensitive material comprises a dispersion material which is obtained by emulsifying a mixture of a yellow coupler represented by the formula and a polymer compound that is insoluble in water and soluble in an organic solvent.

Abstract: A color photographic material with a support and at least one spectrally sensitised silver halide emulsion layer containing at least one color coupler, which layer contains a polymer with repeat units of the structure I ##STR1## in which R.sub.1, R.sub.2, R.sub.3 are identical or different and mean hydrogen, alkyl or halogen,L means a chemical bond or a linking member andX means a group which reacts with NH.sub.2 --, COOH-- or OH-- groups in an addition or condensation reaction,in dispersed form with an average particle size of <300 nm, is distinguished by improved "dark fading" stability.

Abstract: A silver halide color photographic element comprising a support, a silver halide emulsion and poly(alkylene oxide)s wherein greater than 50 percent of the poly(alkylene oxide)s have acidic functional end groups with an aqueous pKa.ltoreq.10, or end groups which will react to form acidic functional end groups with an aqueous pKa.ltoreq.10 during development, on both termini; and wherein the poly(alkylene oxide)s have a molecular weight ranging substantially between 1700 and 6000 AMU.

Abstract: The present invention is an imaging element which includes a support, and at least one imaging layer superposed on the support. A protective overcoat is superposed on the support, and is formed by coating and subsequent drying of an aqueous coating composition having therein colloidal polymer particles having a glass transition temperature of greater than 20.degree. C. and a fluoropolyether including more than 90 mole % units selected from the group consisting of --CF.sub.2 --CF.sub.2 --O--, --CF.sub.2 --O--, --CF(CF.sub.3)--O--, and --CF.sub.2 --CF(CF.sub.3)--O--, and a functional group selected from the group consisting of COOH, --CH.sub.2 --OH, --CH.sub.2 --COOH, --CH.sub.2 --SO.sub.3 H, --CH.sub.2 --PO.sub.3 H, --(CH.sub.2 --CH.sub.2 --O)--H, and --(CH.sub.2 --CH(CH.sub.3)--O--)--H. The present invention includes the imaging element produced from the coating composition.

Abstract: The present invention is a photographic element which includes a support having a front surface and a back surface, and a silver halide imaging layer superposed on the front side of the support. A backing layer is superposed on the backside of the support and is formed by the coating and subsequent drying of an aqueous coating composition having therein a mixture of film-forming colloidal particles and non-film-forming colloidal particles and a fluoropolyether comprising more than 90 mole % units selected from the group consisting of --CF.sub.2 --CF.sub.2 --O--, --CF.sub.2 --O--, --CF(CF.sub.3)--O--, and --CF.sub.2 --CF(CF.sub.3)--O--, and a functional group selected from the group consisting of COOH, --CH.sub.2 --OH, --CH.sub.2 --COOH, --CH.sub.2 --SO.sub.3 H, --CH.sub.2 --PO.sub.3 H, --(CH.sub.2 --CH.sub.2 --O)--H, and --(CH.sub.2 --CH(CH.sub.3)--O--)--H.

Abstract: A silver halide emulsion is disclosed, comprising at least a dispersing medium and silver halide grains, wherein at least 60% of the total projected area of silver halide grains is occupied by tabular grains having a crystal defect for anisotropic growth which have a {100} face as a main plane and an aspect ratio (diameter/thickness ratio) of not less than 2.0, and the right-angled parallelogram enclosed with {100} faces at the edges of the tabular grains or a right-angled parallelogram formed by extending the {100} faces at the edges having a slenderness side ratio (a ratio of the length of the long side to that of the short side) of 1 to 6; and said silver halide emulsion is prepared in the presence of a compound A.sup.0 and/or a compound B.sup.0, wherein the compound A.sup.0 represents an organic compound having covalently bonded to an individual molecule thereof at least two molecules of an adsorbable agent which accelerates formation of a {100} face of silver bromide grains, and the compound B.sup.

Abstract: The invention concerns a process for coating a photographic support.The process consists of depositing on a support a succession of at least two layers, at least one of which consists of a photosensitive composition, the top layer, situated at the opposite side to the support, containing a given concentration of at least one surfactant, the process being characterized in that a surfactant present in the top layer is introduced into the layer adjacent to the top layer at a concentration equal to at least 25% of the concentration of the same surfactant in the said top layer.

Abstract: Tabular gain silver halide emulsions prepared in the presence of a block copolymer selected from the group consisting of:A--B, A--(B--A).sub.m, B--(A--B).sub.m, (A--B).sub.p --X, (B--A).sub.p --X, ?A--(B--A).sub.m !.sub.p --X, and ?B--(A--B).sub.m !.sub.p --Xwhere m is an integer of 1 or more, p is an integer of 3 or more, X represents a p-valent linking group, A represents a poly(tetrahydrofuran) block, and B represents a poly(ethylene oxide) block.

Abstract: A process is disclosed of preparing a photographic emulsion comprised of high bromide silver halide tabular grains accounting for greater than 90 percent of total grain projected area. The grains exhibit a low level of size dispersity by reason of forming in the presence of a dispersing medium containing a polyalkylene oxide block copolymer surfactant a population of silver halide grain nuclei containing twin planes, the halide content of the grain nuclei consisting essentially of silver bromide, and growing the silver halide grain nuclei containing twin planes to form the tabular silver halide grains. Inadvertent variation in tabular grain sizes and thicknesses from one precipitation to the next are minimized by growing the silver halide grain nuclei at a pH in the range of from 3.0 to 8.0 and in the presence of at least a 0.01M concentration of a partially dissociated acid having a pKa that is within 2.