Abstract: A thermal imaging method is provided which employs as color-forming co-reactants, (a) a substantially colorless di- or triarylmethane compound possessing on the meso carbon atom within its triarylmethane structure an aryl group substituted in the ortho position with a nucleophilic moiety which is ring-closed on the meso carbon atom and (b) an electrophilic reagent which upon heating and contacting said di- or triarylmethane compound undergoes a bimolecular nucleophilic substitution reaction with the nucleophilic moiety to form a colored, ring-opened di- or triarylmethane compound.

Abstract: An alloy having variable spectral reflectance having a composition which essentially consists of Ag, 30 to 46 wt % of Zn and 0.1 to 15 wt % in total of at least one element selected from elements of groups Ia, IIa, Iva, Va, VIa, VIIa, VIII, Ib to Vb and rare earth elements, the alloy being able to have different crystal structures, one of which is obtained when it is held in solid state at a first temperature above the room temperature, another of which is obtained when the same is held in the solid state at a second temperture lower than said first temperature. Disclosed also is an information recording medium made of the alloy. The alloy exhibits a reversible change in color or spectral reflectance as a result of change between two crystal phases, so that the information recording medium produced from this alloy can be used effectively as the medium for recording, regeneration and erasion of the informations.

Abstract: Method for preparing photosensitive silver halide crystals. A binder resin, a source of halide ions, and a source of silver ions are dissolved in an organic solvent, e.g., ethanol. Silver halide nuclei will then form. Additional source of halide ions and additional source of silver ions can be added to the solution in incremental additions, so that the initially-formed silver halide nuclei will grow. Upon removal of the solvent, the silver halide crystals will exist in a dry state, entrapped in the binder resin. Silver halide crystals formed and grown in this manner can be used to prepare photothermographic imaging compositions, which compositions will exhibit higher speed than photothermographic imaging compositions containing silver halide crystals grown according to conventional methods.

Abstract: An optical recording medium such as an optical disc memory, with which data can be stored and reproduced by means of laser beam with a high sensibility is disclosed.The optical recording medium comprises:a substrate transparent to the laser beam;a first spacer layer formed on the substrate, being substantially transparent to the laser beam and having a higher refractive index than the substrate with respect to said laser beam;a second spacer layer formed on the first spacer layer, being substantially transparent to the laser beam and having a lower refractive index than the first layer with respect to said laser beam; anda recording layer formed on the second spacer layer and for storing data therein by the radiation of laser beam.

Abstract: The present invention provides a process for preparing a negative image of high contrast comprising developing an exposed silver halide photographic material which is substantially a surface latent image-type material in the presence of a hydrazine derivative, wherein said material is processed with a water-soluble alkaline developer having a pH value of from 10.5 to 12.3 and at least comprising the following components (1) through (3):(1) a dihydroxybenzene-type developing agent;(2) 0.3 mole/liter (developer) or more of a sulfite preservative; and(3) from 0.01 to 0.30 mole/liter (developer) of a compound of formula (A) ##STR1## in which R.sub.2 represents an alkyl group having from 3 to 6 carbon atoms; R.sub.3 and R.sub.4 each represents an alkyl or hydroxyalkyl group having from 1 to 10 carbon atoms.The formed negative images are of high contrast and are almost free from silver stain. The sensitivity is high and the dot image quality is good.

Abstract: A photothermal transducing type of recording medium comprises at least one azulenium salt represented by the general formula [I], [II], [III], or [IV].

Abstract: A silver halide photographic material comprising a support having at least one silver halide emulsion layer containing substantially surface latent image type silver halide grains, said emulsion layer or at least one hydrophilic colloid layer adjacent to the emulsion layer containing a compound represented by general formula (III): ##STR1## wherein L.sub.2 represents --CONR--, --SO.sub.2 NR-- or --NRCONR' and Z, L.sub.1, m, Ro, R.sub.1 and M are as herein described. The silver halide photographic material is capable of having high contrast negative images, high sensitive negative images, and good dot images.

Abstract: A radiation-sensitive composition including silver halide grains capable of forming an internal latent image and a nucleating agent is useful as a coating on a support to form a photographic element.

Abstract: A silver halide photographic material for use in the field of graphic arts and a process for forming a high-contrast negative image using the same, wherein the silver halide emulsion layer or another layer of the silver halide photographic material provided on the support contains at least one compound represented by the formula (I) and at least one blocked development restrainer compound represented by the formula (II): ##STR1##

Abstract: This invention relates to an optical recording medium comprising a recording layer of a dye or dye composition on a substrate and adapted to be written and read using light such as laser or the like. The optical recording medium of the invention is characterized by further comprising a surface layer formed of a coating of a colloidal particle dispersion of a silicon base condensate on the recording layer, with improved S/N ratio as well as improved writing sensitivity and reading output of the optical recording medium.

Abstract: A silver halide photographic light-sensitive material which is excellent in raw-stock preservability, physical characteristics of its layers such as glossiness, scratch resistance, and degree of swelling and whose sensitivity changes very little with time after manufacture comprising a compound represented by Formula [I] of the specification, hardened with at least one of the compounds represented by Formula [II] or [III] of the specification. The storage stability is further improved when at least one of the cyan couplers represented by Formula [IX] or [X] of the specification is present.

Abstract: The process for improving radiant energy sensitivity of a film base coated with a dispersion of a normally crystalline polyacetylenic compound in a non-solvating liquid which is dried on the film surface; said polyacetylenic compound preferably having at least two conjugated acetylenic linkages and containing from 20 to 60 carbon atoms. The process comprises dispersing said normally crystalline polyacetylenic compound in the non-solvating liquid to a concentration of from about 2 to about 50% polyacetylene crystalline solids and ageing said dispersion by (a) storing at a temperature of between about 0.degree. C. and about 12.degree. C. for a period of from about 1 to about 30 days or (b) freezing said dispersion at a temperature between about -78.degree. C. and about -1.degree. C. for a period of from about 1 to about 75 hours or (c) a combination of the above ageing techniques any or all of which are completed before drying said dispersion on a substrate.

Abstract: A silver halide color light-sensitive material is described, which is increased in sensitivity, is adapted to form an image of high contrast, or is accelerated in development by incorporating a small amount of a specific compound which imagewise releases a foggant or a development accelerator. This compound is represented by the formula: Coup-(TIME).sub.n -FA (wherein Coup represents a coupler radical capable of undergoing a coupling reaction with an oxidized product of an aromatic primary amine developing agent; TIME represents a timing group which is eliminated from Coup by the coupling reaction and, thereafter, releases FA; n is 0 or 1; and FA represents a group which is eliminated from Coup in the coupling reaction when n is 0, whereas FA is released from TIME when n is 1. The FA has adsorption properties with respect to silver halide grains and also has a substantial fogging action with respect to the silver halide grains).

Abstract: A heat-developable light-sensitive material is described, comprising a support having provided thereon at least(a) a binder;(b) a light-sensitive silver halide;(c) at least one silver salt of a compound represented by formula (I) or (II) ##STR1## wherein Z represents a non-metallic atomic group forming a heterocyclic ring together with the nitrogen atom,A--C.tbd.

Abstract: A heat developable light-sensitive material comprising a support having thereon at least one light-sensitive layer wherein at least one layer comprises a compound represented by the following general formula (I): ##STR1## wherein R.sub.1 and R.sub.2, which may be the same or different, each represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aralkyl group, an aryl group, a heterocyclic group each of which may be substituted or unsubstituted; a carboxy group or a salt thereof; R.sub.3 and R.sub.

Abstract: A silver halide photographic material having one or more silver halide emulsion layers formed on a support is disclosed wherein at least one of said silver halide emulsion layers contains at least one cyan coupler of formula (I) dispersed therein with the aid of a high-boiling organic solvent having a dielectric constant of not more than 6.0: ##STR1## (wherein R.sub.1 is a straight- or branched-chain alkyl group having 2 or 4 carbon atoms; X is a hydrogen atom or a group capable of leaving upon coupling reaction; and R.sub.2 is a ballast group).

Abstract: A silver halide photographic light-sensitive material is disclosed, comprising a monodisperse silver halide emulsion of 0.30 .mu.m or less in average silver halide grain size containing at least 75 mol % silver chloride and 2 mol % or less silver iodide, and having incorporated in said emulsion a dye represented by the formula (I) ##STR1## wherein Z represents atoms forming a thiazoline nucleus, a thiazole nucleus, or a benzothiazole nucleus,X represents an oxygen atom or a sulfur atom, andR.sub.1 and R.sub.2 each represents an unsubstituted or substituted aliphatic group or an unsubstituted or substituted aromatic group.

Abstract: A light-sensitive silver iodobromide emulsion containing core/shell silver iodobromide grains having a core substantially comprising silver iodobromide containing at least about 5 mol % of silver iodide and a shell selected from the group consisting of (a) a shell comprising silver iodobromide having a lower silver iodide content than that of the silver iodobromide of the core and (b) a shell comprising silver bromide, wherein the relative standard deviation of the silver iodide content of the individual grains of said silver halide emulsion is lower than about 20%.

Abstract: A heat-developable light-sensitive material is described, comprising a support having thereon at least (1) a light-sensitive silver halide, (2) a silver salt oxidizing agent, (3) silver salt particles having adsorbed thereon at least one compound selected from a cyclic imino compound represented by formula (I) described below and a mercapto compound represented by formula (II) described below, (4) a reducing agent, and (5) a binder.Formula (I) is represented by ##STR1## wherein Z represents a non-metallic atomic group forming a heterocyclic ring containing an imino group together with the nitrogen atom of formula (I).Formula (II) is represented byR--S--M (II)wherein M represents a hydrogen atom or an alkali metal atom; and R represents a substituted or unsubstituted aliphatic hydrocarbon group, a substituted or unsubstituted aromatic hydrocarbon group, or a substituted or unsubstituted heterocyclic group.

Abstract: Photographic element comprising a support and a silver halide emulsion layer comprising in said emulsion layer and/or in a water-permeable layer coated at the same side of the support as said emulsion layer a compound corresponding to the following general formula: ##STR1## wherein: each of R.sup.1, R.sup.2, and R.sup.3, which may be the same or different, can represent hydrogen, C.sub.1 -C.sub.8 alkyl, or Alk.sub.1 - X - Alk.sub.2 - Y -, wherein: Alk.sub.1 is C.sub.1 -C.sub.8 alkyl, which may be substituted, X is --O-- or --S--, Alk.sub.2 is C.sub.1 -C.sub.8 alkylene, which may be substituted, and Y is a single bond, --O--, --S--, --CONH--, --SO.sub.2 NH--, or --NHCONH--, R.sup.3 can alternatively represent C.sub.1 -C.sub.8 alkyl-thio, the C.sub.1 -C.sub.8 alkyl group of which can be substituted, at least one of R.sup.1, R.sup.2, and R.sup.3, however, being other than hydrogen and other than C.sub.1 -C.sub.8 alkyl.The invention disclosed includes compounds per se, which correspond to said general formula.