US3925084A - Direct-positive silver halide emulsion containing a cyanine dye having a pyrazolo(1,5-a)benzimidazole nucleus - Google Patents

Direct-positive silver halide emulsion containing a cyanine dye having a pyrazolo(1,5-a)benzimidazole nucleus Download PDF

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US3925084A
US3925084A US351386A US35138673A US3925084A US 3925084 A US3925084 A US 3925084A US 351386 A US351386 A US 351386A US 35138673 A US35138673 A US 35138673A US 3925084 A US3925084 A US 3925084A
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silver halide
nucleus
group
direct positive
halide emulsion
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Akira Sato
Keisuke Shiba
Masanao Hinata
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Fujifilm Holdings Corp
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Fuji Photo Film Co Ltd
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B23/00—Methine or polymethine dyes, e.g. cyanine dyes
    • C09B23/10—The polymethine chain containing an even number of >CH- groups
    • C09B23/107—The polymethine chain containing an even number of >CH- groups four >CH- groups
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B23/00—Methine or polymethine dyes, e.g. cyanine dyes
    • C09B23/10—The polymethine chain containing an even number of >CH- groups
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B23/00—Methine or polymethine dyes, e.g. cyanine dyes
    • C09B23/10—The polymethine chain containing an even number of >CH- groups
    • C09B23/105—The polymethine chain containing an even number of >CH- groups two >CH- groups
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03C—PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR, STEREO-PHOTOGRAPHIC PROCESSES; AUXILIARY PROCESSES IN PHOTOGRAPHY
    • G03C1/00—Photosensitive materials
    • G03C1/005—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein
    • G03C1/485—Direct positive emulsions
    • G03C1/48515—Direct positive emulsions prefogged
    • G03C1/48523—Direct positive emulsions prefogged characterised by the desensitiser
    • G03C1/4853—Direct positive emulsions prefogged characterised by the desensitiser polymethine dyes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
    • Y10S430/1053—Imaging affecting physical property or radiation sensitive material, or producing nonplanar or printing surface - process, composition, or product: radiation sensitive composition or product or process of making binder containing
    • Y10S430/1055—Radiation sensitive composition or product or process of making
    • Y10S430/106—Binder containing
    • Y10S430/112—Cellulosic

Definitions

  • This invention relates to photographic silver halide emulsions, more particularly, it relates to a direct positive silver halide emulsion sensitized by a dye having a novel pyrazoloi 1,5-albenzimidazole nucleus.
  • direct positive silver halide emulsion in this specification means a silver halide emulsion prepared such that it directly forms a positive image after ordinary exposure to light, i.e., positive light image development.
  • sensitizers for ordinary negative silver halide emulsions there are known many dyes such as monomethinecyanine dyes, trimethinecyanine dyes, merocyanine dyes and rhodacyanine dyes.
  • monomethinecyanine dyes trimethinecyanine dyes
  • merocyanine dyes merocyanine dyes
  • rhodacyanine dyes rhodacyanine dyes.
  • the use of these dyes for the sensitization of direct positive silver halide emulsions is frequently accompanied with disadvantages, for instance, softening or flattening of characteristic curves and re-reversal (the phenomenon that with an increase in the exposure amount the blackened density decreases and then the blackened density increases again).
  • dyes conventionally known as sensitizers for direct positive silver halide emulsions frequently have faults such as leaving color stains after processing of photographic silver halide materials containing them.
  • the formation of such color stains is particularly inconvenient for color photographic papers.
  • dyes are used as sensitizers high whiteness is not obtained in black and white photographic papers and further true color reproduction cannot be obtained in color photographic papers.
  • the formation of such color stains is particularly undesirable in hard or high contrast photographic materials used for lithographic films, X-ray photographic films, duplication films for microphotographs, etc.
  • the dyes used for the sensitization of direct positive silver halide emulsions should not exhibit the above faults and further should not reduce the maximum density of the images formed.
  • An object of this invention is, therefore, to provide a direct positive silver halide emulsion of high sensitivity, desired maximum image density and further giving substantially no color stains.
  • the invention provides a direct positive 5 silver halide emulsion containing at least one cyanine being, however, only when the cyanine heterocyclic nucleus is a quinoline nucleus or a pyridine nucleus.
  • cyanine heterocyclic nu cleus of the cyanine dye used in this invention include an oxazoline nucleus, an oxazole nucleus, a benzoxazole nucleus, a naphthoxazole nucleus, a thiazoline nucleus, a thiazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a selenazole nucleus, a benzoselenazole nucleus, 21 naphthoselenazole nucleus, a 2-pyridine nucleus, a 4-pyridine nucleus, a Z-quinoline nucleus, a 4quinoline nucleus, a 3-isoquinoline nucleus, a l-isoquir ioline nucleus, an imidazole nucleus, :1 benzimidazole nucleus, an in
  • the benzene rings of those heterocyclic rings and/or the condensed heterocyclic rings may have substituents
  • substituents are an alkyl group, an aryl group, a hydroxyl group, an alkoxyl group, a carboxyl group, an alkoxycarbonyl group, a nitro group, and a halogen atom, with preferred alkyl groups or moieties having l-20 carbon atoms, preferred alkoxy groups having 1 10 carbon atoms and a preferred aryl group being a phenyl group.
  • thiazoles such as thiazole, 4-methylthiazole, 4phenylthiazole, 4-(p-hydroxyphenyl)thiazole, Smethylthiazole, S-phenylthiazole, S-(o-hydroxyphen yl thiazole, 4,5-dimethylthiazole and 4,5-diphenylthiazole; benzothiazoles such as benzothiazole, 4- hydroxybenzothiazole, 4-fluorobenzothiazole, 4- chlorobenzothiazole 5-chloroben zothiazole, 6- chlorobenzothiazole, 7-chlorobenzothiazole, 4-methylbenzothiazole, S-methylbenzothiazole, fi-methylbenzothiazole, 5 ,-dimethylbenzothiazole 5 -bromoben zothiazole, 6-bromobenzothiazole, S-phenylbenzothiazole, 6-phenylbenzothiazole, 6-phenylbenzothiazole
  • benzoxazoles such as benzoxazole, fi-chlorobenzoxazole, S-methylbenzoxazole, phenylbenzoxazole, fi-methylbenzoxazole, 6-nitr0benzoxazole.
  • Z-pyridines such as pyridine, 4-methylpyridine, -methylpyridine, 4,6-dimethylpyridine, 4- butylpyridine, 4-decylpyridine, 4-octadecylpyridine, 4,6-dibutylpyridine, 4-benzylpyridine, 4-phenylpyridine, 4-(p-hydr0xyphenyl)pyridine, 4,6-diphenylpyridine, 4,6-dinaphthylpyridine, 4-chloropyridine, 4- bromopyridine, 4,6-dichloropyridine, 4-chl0ropyridine, -bromopyridine, 4-hydr0xypyridine, 4-meth0xypyridine, 4-ethoxypyridine, 6-methoxypyridine, 6- ethoxypyridine and 4,6-dimeth0xypyridine; 4-pyridines such as pyridine, Z-methyIpyridine, 2-butylpyridine, 2- decyl
  • Examples of preferred cyanine dyes used in the present invention can be shown by the following general formulae I and II.
  • R and R each represents an unsubstituted alkyl (C,C group such as a methyl group,
  • the cyanine dyes shown by the aforesaid general formula I can be prepared by reacting under heating a compound represented by general formula III Formula II] 6 wherein R R and p have the same significance as in the General formula I and a heterocyclic quaternary ammonium salt represented by the general formula IV wherein Y represents SR, OR", or
  • R and R" each represents a methyl group, an ethyl group or a phenyl'group
  • R Z, L L n, m, and X have the same significance as in General formula l in ethanol in the presence of an organic base such as triethylamine.
  • the cyanine dyes represents by general formula I can also be prepared by reacting a compound represented by general formula V obtained by subjecting the compound of the above-mentioned general formula III to a Vilsmeier reaction Formula V CH3 R -c ⁇ L-cEcn-N ⁇ cH3 wherein R R and p have the same significance as in general formula I and a heterocyclic quaternary ammonium salt represented by general formula VI wherein R, L,, L X@ 2, m, and n have the same significance as in general formula I in acetic anhydride with heating and then treating the product with an alkali. ln place of reacting the above reactants in acetic anhydride, both reactants may be reacted in nitrobenzene in the presence of an organic base such as triethylamine, while heating, before the alkali treatment.
  • an organic base such as triethylamine
  • the dyes represented by general formula ll may be obtained by alkylating a cyanine dye represented by general formula I with an ordinary quaternizing reagent such as dimethyl sulfate, methyl-p-toluene sulfonate, propane sultone, butane sultone and an alkyl halide.
  • an ordinary quaternizing reagent such as dimethyl sulfate, methyl-p-toluene sulfonate, propane sultone, butane sultone and an alkyl halide.
  • an ordinary quaternizing reagent such as dimethyl sulfate, methyl-p-toluene sulfonate, propane sultone, butane sultone and an alkyl halide.
  • the alkylation will occur to the nitrogen atom at the l-position of the pyrazolo[ l ,5- a]benzimidazole nucleus or the nitrogen
  • the direct positive silver halide emulsion of this invention contain an organic desensitizer.
  • the organic desentizer used herein refers to a mate rial having the faculty of catching or trapping l'ree electrons generated in silver halide grains by irradiation and capable olbeing adsorbed on the silver halide.
  • the organic descnsitizer can further be defined as a material having a minimum space electron energy level lower than the electron energy level ol the conductive zone of the silver halide grains. It is preferably a com pound having a maximum occupied electron energy level lower than the valence electron zone of the silver halide grains. l'hc values of these electron energy levels can be determined, although complicated procedures are required for the measurement.
  • R represents an alk 1 group or an allyl group
  • R examples include a methyl group, an ethyl group, a butyl group, a hydroxyalkyl group (e.g.,
  • a hydroxyethyl group a carboxyalkyl group (e.g., carboxymethyl group and a B-carboxypropyl group) and a sulfoalkyl group (e.g., a 2-sulfoethyl group and a 4-sulfobutyl group).
  • carboxyalkyl group e.g., carboxymethyl group and a B-carboxypropyl group
  • a sulfoalkyl group e.g., a 2-sulfoethyl group and a 4-sulfobutyl group.
  • organic desensitizers which can be employed in the present invention are, phenosafra- 3 nine, pinakryptol yellow, 5-m-nitrobenzylidenerhoda- -nine, 3-ethyl-5-m-nitrobenzilidene rhodanine, 3-ethyl- 5-(2,4 dinitrobenzilidene) rhodanine, 5o-dinitrobenzilidene-3-phenylrhodanine, l,3-diethyl6-nitrothia-2'- cyanineiodine salt, 4-nitro-6-chlorobenzotriazole, 3,3'-diethyl-6,6-dinitro-9-phenylthiacarbocyanine.io-
  • iodine salt 3 ,3 '-dip-nitrophenylthiacarbocyanine 3 3 dimethyl-9-trifluoromethylthiacarbocyanine.iodine salt, 9-( 2,4-dinitrophenylmercapto)3 ,3 '-diethylthiac arbocyanineiodine salt, bis(4,6-diphenylpyryl-Z-trimethinecyanine.perchlorate, anhydrous 2-p-dimethylaminophenyliminomethyl-6-nitro-3-(4-sulfobutyl)- benzothiazolium.
  • a silver chloride emulsion there are illustrated a silver chloride emulsion, a silver bromide emulsion, a silver chlorobromide emulsion, a silver chloroiodide emulsion and a silver chloroiodobromide emulsion.
  • the grain size of such silver halides can be in the gen- ,5
  • the silver halide grains used in this invention can be reglar grains or irregular grains, but the invention is applied more effectively when regular silver halide grains are usedv
  • a simple dispersion type silver halide emulsion or a non-simple dispersion type silver halide emulsion can be used in this invention, but the use of a simple dispersion type emulsion is more preferred.
  • silver halide emulsions used for direct positive silver halide photographic materials are classitied into the following two types.
  • the first type is a silver halide emulsion having nuclei capable of trapping free electrons in the silver halide crystals, the surfaces of the silver halide grains of which have been preliminarily fogged chemically.
  • the main feature of the silver halide emulsion of this type is that by the addition of a sensitizing dye or dyes the silver halide emulsion is highly sensitized by the action of spectral sensitization as well as being sensitized in its characteristic absorption region.
  • a silver halide emulsion of this type is required to have its halogen composition adjusted so that the chemical sensitizers or the salts of metals belong to group VIII of the periodic table used for providing free electron trapping nuclei are readily incorporated in the silver halide.
  • the occurence of clearance and particularly the occurence of re-reversal can be prevented.
  • bromide ions or iodide ions added to a silver halide emulsion of this type the maximum density can be increased, the emulsion can be further sensitized and also the occurence of clearance can be prevented.
  • Emulsions of this type are described in US. Pat. Nos. 2,401,051, 2,717,833, 2,976,149 and 3,023,102, British Pat. Nos. 707,704, 1,097,999 and 1,520,822, and French Pat. Nos. 1,523,626, 1,520,817 and 1,520,824.
  • the second type is a silver halide emulsion which has no free electron trapping nuclie in the silver halide, the surfaces of the silver halide grains of which have been chemically fogged.
  • This type of emulsion has crystal defects as low as possible and comprises regular silver halide crystals having no twinning plane, and is prefera- 0 bly pure silver bromide. While this type of silver halide emulsion does not give direct positive images per se, if an organic desensitizer is adsorbed on the silver halide of the emulsion, direct positive images can be obtained.
  • Emulsions of this type are described in US. Pat. Nos.
  • silver halide emulsions of both types can be employed.
  • both types of the aforesaid silver halide emulsions can be effectively sensitized by the compound or the cyanine dyes of the present invention.
  • the silver halide emulsions used in this invention can be fogged by light or chemically.
  • Chemically fogged nuclei are formed by the addition of a reducing organic compound such as a hydrazine derivative, formalin, thiourea dioxide, a polyamine compound, amine borane or methyldichlorosilane and the like as disclosed in Belgian Pat. Nos. 721,564 and 708,563, US. Pat. No. 2,588,982, British Pat. No. 821,251, French Pat. No. 739,755 and Japanes Pat. Publication No. 43-13488.
  • a reducing organic compound such as a hydrazine derivative, formalin, thiourea dioxide, a polyamine compound, amine borane or methyldichlorosilane and the like as disclosed in Belgian Pat. Nos. 721,564 and 708,563, US. Pat. No. 2,588,982, British Pat. No. 821,251, French Pat. No. 7
  • the fogged nuclei can also be formed, in addition to the aforesaid manner, by the combination of a reducing agent and ions of a metal nobler than silver, such as gold ions, platinum ions or iridium ions or by a combination of such metals and halogen ions, as disclosed in US. Pat. Nos. 2,717,833 and 3,023,102, Belgian Pat. Nos. 713,272 and 721,567 and British Pat. No. 707,704.
  • gelatin is generally used as the protective colloid, and inert gelatin is particularly preferred.
  • a photographically inert gelatin derivative or watersoluble synthetic polymer such as polyvinyl acrylate, polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl alginate, carboxymethyl cellulose, and hydroxymethyl cellulose may be used, as may mixtures of any such materials.
  • the direct positive silver halide emulsions of this invention can further contain, if desired, a stabilizer for the fogged nuclei, such as a mercapto compound, a thion compound or a tetraazaindene compound; an agent to prevent the occurence of clearing (often re ferred to as uncoloring), such as a stilbene compound or an azine compound; a whitening agent; an ultraviolet absorbant; a hardening agent such as chromium alum, a 2,4-dichloro-s-triazine compound, an aziridine compound, an epoxy compound, a mucohalogenic acid compound (e.g., halogen formyl maleic acid compound); a wetting agent such as sodium polyalkylene sulfonate or saponin or an anionic surface active agent having a betaine structure; an antiseptic or disinfectant agent; a plasticizer such as polyalkyl acrylate, a copolymer of an alkylacrylate
  • the amount of the dimethine dye depends upon the amount of the silver halide and the surface area of the silver halide grains in the silver halide emulsion, but good results are obtained when the amount is l X to 2 X 10 mol of dye or dyes per mol of silver halide.
  • These dye(s) are generally added to the silver halide emulsion as a solutions in a solvent miscible with water, such as methanol, ethanol, ethyleneglycol monomethyl ether, methylethyl ketone, acetone and pyridine, as well as water.
  • a solvent miscible with water such as methanol, ethanol, ethyleneglycol monomethyl ether, methylethyl ketone, acetone and pyridine
  • ultrasonic waves may be applied to the system to promote dissolution.
  • the dyes can be added to the silver halide emulsion just before coating, but they can be added during chemical ripening of the silver halide emulsions or during precipitation of the silver halide(s).
  • the amount of the organic desensitizer used in the present invention depends upon the kind of desensitizer, but is preferably 2 X 10 to 10 mol per mol of silver halide.
  • the silver halide emulsions of this invention can be applied to various supports to give photographic elements.
  • the silver halide emulsions of this invention can be applied to one surface or both surfaces of the support and the support may be transparent or opaque.
  • Typical examples of the supports are cellulose nitrate films, cellulose acetate films, polyvinyl acetal films, polystyrene films, polyethylene terephthalate films, other polyester films, glasses, papers, metallic foils and woods. Plastic-laminated papers can also be used as the support. The exact support chosen is not important.
  • the photographic silver halide material comprising the silver halide emulsion layer of this invention may be processed after exposure in the manner used for prior art direct positive emulsions, e.g., in separate develop ment, fix, stabilization, etc., baths or in a bath having a combination of such processing functions.
  • the first feature of the present invention is that the direct positive silver halide emulsion is sensitized by at 30 least one cyanine dye having the pyrazolo[ l,5-a]ben- Zimidazole nucleus.
  • alkylated cyanine dyes give higher sensitivity to the silver halide emulsion.
  • the second feature of the present invention is that a direct positive silver halide emulsion having a sharp spectral sensitization maximum is obtained.
  • the spectral sensitivity curve of the direct positive silver halide emulsion of this invention has such a form that the longer wave length end of it is sharply cut. Therefore, the photographic materials prepared using the direct positive silver halide emulsions of this invention can be easily handled under a safe light.
  • the third feature of the present invention is that the cyanine dye (or dyes) having the pyrazolo[ l,5-a]benzimidazole nucleus used in this invention has the excellent property of not substantially reducing the maximum density of the direct positive silver halide emulsion.
  • the fourth feature of the present invention is that the direct positive silver halide emulsion of this invention shows substantially no reduction in maximum density during storage.
  • novel dimethine dyes used in this invention have such excellent features as mentioned above, and further by using the dimethine dyes together with the aforesaid organic desensitizers, the reversal sensitivity of the silver halide emulsions can further be improved and also direct positive silver halide emulsions showing excellent clearance can be prepared.
  • the direct positive silver halide emulsions of this invention can, of course, be used for making duplicating photographic materials for lithographic films and hard or high contrast direct positive silver halide photographic materials used for duplicating originals as well as for making duplicating photographic materials for microphotographic films and also comparatively soft direct positive silver halide photographic materials such as duplicating photographic materials for X-ray photographs.
  • the direct positive silver halide emulsion can also be used for making color photographic materials.
  • the direct positive silver halide emulsions of this invention can be used not only for the case of exposure to light, but also for the case of exposure to electrons, X- rays or gamma rays.
  • dimethine dyes to be used in this invention can be also used as photographic dyes, such as dyes for light-filtering layers, dyes for anti-irradiation and antihalation, etc.
  • EXAMPLE 1 The following four solutions were prepared for making silver halide emulsion.
  • the second so lution and the third solution were added to the first solution over a 50 minute period and then the mixture was physically ripened for 5 minutes by permitting it to stand at 60C.
  • 15 cc of a 0.2 normal aqueous potassium iodide solution was added to the ripened mixture and thereafter the pAg of the mixture was adjusted to 6.0 using an aqueous silver nitrate solution.
  • 12 mg hydrazine and 1.0 mg gold chlorine were added to the mixture and after adjusting the pH thereof to ID using aqueous sodium hydroxide solution, the resultant mixture was further ripened for 10 minutes by permitting it to stand at 60C.
  • the mixture was neutralized using citric acid and then was washed with water.
  • the mixture was melted again and the forth solution indi cated above was added thereto to give the silver halide emulsion.
  • the silver halide emulsion thus prepared contained silver halide grains having a mean grain size of about 0.2 microns, the silver halide grains being regular tetragonal system grains having the (100) plane.
  • a methanol solution of the dimethine dyes as shown in Table l was added to the silver halide emulsion prepared above, and after further adding 40 ml/Kg of emulsion of a 4 wt aqueous solution of saponin, the resultant emulsion was applied to a cellulose triacetate film in a dry thickness of about 5 microns to give a sample photographic material.
  • the sample was exposed for 1 second through an optical wedge to a tungsten light source of 2854K, developed in the developer having the following composition for 2 minutes at 20C., and then fixed in an acid hardening fix solution.
  • composition of the developer is composition of the developer:
  • EXAMPLE 2 The silver halide emulsion used in this example was prepared in the following manner.
  • the resultant mixture was then further rippened for l0 minutes at 60C and, after reducing the temperature to 35C, the mixture was washed with water.
  • the mixture was heated again, the pH thereof was adjusted to 10, hydrazine and gold chloride were added thereto in the amounts given in Example 1, and the mixture was ripened again for 10 minutes. Thereafter, the pH of the ripened mixture was adjusted to 6.5 using 8 ml of 10 wt citric acid.
  • a fifth solution prepared by dissolving g of inert gelatin in 300 cc of water was added to the mixture to yield the silver halide emulsion.
  • the mean grain size of the silver halide grains in the silver halide emulsion thus obtained was about 0.15 micron.
  • the sample prepared was exposed* through an optical wedge to a tungsten light source of 2854K and developed for 3 minutes at 20C. in the developer having the following composition. exposure time I second Composition of the developer:
  • a fogged direct positive silver halide emulsion containing at least one cyanine dye comprising a pyrazolo[ l,5-a]benzimidazole nucleus and a cyanine heterocyclic nucleus, which nuclei may be substituted with substituents as are commonly used in the cyanine dye art, in which the carbon atom at the 3-position of the pyrazolol l,5-a]benzimidazole nucleus is joined to the 2-position or 4-position of the cyanine heterocylic nucleus, by a methine chain, the carbon atom being joined to the 4-position, however, only when the cyanine heterocyclic nucleus is a quinoline nucleus or a pyridine nucleus, said cyanine dye being present in a concentration effective to provide high sensitivity, maximum image density and providing substantially no color stains.
  • tive silver halide emulsion comprises silver halide grains fogged by a reducing agent and a gold compound.
  • R and R each represents an alkyl group, a hydroxyalkyl group, an acetoxyalkyl group, an alkoxyalkyl group, a carboxyalkyl group, an alkoxycarbonyl
  • R and R each represents an alkyl group, a hydroxyalkyl group, an acetoxyalkyl group, an alkoxyalkyl group, a carboxyalkyl group, an alkoxycarbonylalkyl group, a sulfoalkyl group, an aralkyl group, a sulfoaralkyl group, a carboxyaralkyl group, or a vinylmethyl group
  • R represents a hydrogen atom, an alkyl group, a carboxyl group, an alkoxycarbonyl group, an amino group, an acylamino group, an aryl group or an acid amide group
  • L and L each represents a methine chain, and L and R may be combined with each other by a methylene chain
  • a fogged direct positive silver halide photo graphic material comprising a support having therein a fogged direct positive silver halide emulsion layer, said silver halide emulsion layer containing at least one cyanine dye comprising a pyrazolo[l,5-a]benzimidazole nucleus and a cyanine heterocyclic nucleus, which nuclei may be substituted with substituents as are commonly used in the cyanine dye art, in which the carbon atom at the 3-position of the pyrazolol l ,5-a]benzimidazole nucelus is joined to the 2-position or the 4- position of the cyanine heterocyclic nucleus by a methine chain, said carbon atom being joined to the 4-position, however, only when the cyanine heterocylic nucleus is a quinoline nucleus or a pyridine nucleus, said cyanine dye being present in a concentration effective to provide high sensitivity, maximum image density and providing substantially no color stains.
  • the carbon atom at the 2-position thereof is methyl or phenyl substituted
  • the nitrogen atom connected to the carbon atom at the 2-position thereof is unsubstituted, methyl substituted or sulfopropyl substituted.
  • the carbon atom at the 2position thereof is methyl or phenyl substituted
  • the nitrogen atom connected to the carbon atom at the 2-position thereof is unsubstituted, methyl substituted or sulfopropyl substituted.
  • a fogged direct positive silver halide photographic material as claimed in claim 22 wherein the amount of said dye is l X l to 2 X mol of dye amino group, an acylamino group, an aryl group or an acid amide group; L, and L each represents a methine chain, and L, and R, may be combined with each other by a methylene chain; R represents a halogen atom, a lower alkyl group, an alkoxyl group, an aryl group, a carboxyl group, an alkoxycarbonyl group or an acylamino group; Z represents an atomic group necessary for forming a cyanine heterocyclic nucleus; Xrepresents an acid anion; n represents 0 or 1, m represents 0. l or 2; and p represents 1, 2, 3, or 4.
  • a fogged direct positive silver halide photocyanme dye IS the compound represented by the folgraphic material as claimed in claim 22 wherein M is l lowing formula: or 2.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
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  • Physics & Mathematics (AREA)
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  • Plural Heterocyclic Compounds (AREA)
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US351386A 1972-04-14 1973-04-16 Direct-positive silver halide emulsion containing a cyanine dye having a pyrazolo(1,5-a)benzimidazole nucleus Expired - Lifetime US3925084A (en)

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US (1) US3925084A (enrdf_load_stackoverflow)
JP (1) JPS5221886B2 (enrdf_load_stackoverflow)
CA (1) CA1008291A (enrdf_load_stackoverflow)
DE (1) DE2318761A1 (enrdf_load_stackoverflow)
FR (1) FR2179987B1 (enrdf_load_stackoverflow)
GB (1) GB1387795A (enrdf_load_stackoverflow)

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JPS5288058A (en) * 1976-01-16 1977-07-22 Shibaura Eng Works Ltd Leveling device for rail
JPS5860216U (ja) * 1982-06-10 1983-04-23 芝浦メカトロニクス株式会社 レ−ルレベリング装置
JPS60107641A (ja) * 1983-11-16 1985-06-13 Fuji Photo Film Co Ltd 内部潜像型コア／シエルハロゲン化銀写真乳剤
EP4290596A4 (en) * 2021-02-05 2024-09-04 FUJIFILM Corporation PHOTOELECTRIC CONVERSION ELEMENT, IMAGING ELEMENT, LIGHT SENSOR AND INTERCONNECTION

Citations (1)

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US3758309A (en) * 1970-01-15 1973-09-11 Eastman Kodak Co -pyrazolo(3,2-c)-s-triazole silver halide emulsions containing sensitizing dyes derived from a 1h

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3758309A (en) * 1970-01-15 1973-09-11 Eastman Kodak Co -pyrazolo(3,2-c)-s-triazole silver halide emulsions containing sensitizing dyes derived from a 1h

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JPS491226A (enrdf_load_stackoverflow) 1974-01-08
CA1008291A (en) 1977-04-12
JPS5221886B2 (enrdf_load_stackoverflow) 1977-06-14
FR2179987B1 (enrdf_load_stackoverflow) 1976-05-21
FR2179987A1 (enrdf_load_stackoverflow) 1973-11-23
GB1387795A (en) 1975-03-19
DE2318761A1 (de) 1973-10-25

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