Classifications

• • 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
  • G03C1/06—Silver halide emulsions; Preparation thereof; Physical treatment thereof; Incorporation of additives therein with non-macromolecular additives
  • G03C1/08—Sensitivity-increasing substances
  • G03C1/28—Sensitivity-increasing substances together with supersensitising substances
  • G03C1/29—Sensitivity-increasing substances together with supersensitising substances the supersensitising mixture being solely composed of dyes ; Combination of dyes, even if the supersensitising effect is not explicitly disclosed

Definitions

• This invention provides a light-sensitive material of the silver halide type having high speed green sensitivity and *being highly supersensitized to green light, which comprises a silver halide photographic emulsion and a specific combination of at least one compound expressed by following formula (I) with at least one compound expressed by following for- 1 34 (II)
• This light-sensitive material can be applied to not only black-and-white photography but also color photography, and is excellent over conventional supersensitized lightsensitive emulsions in spectral sensitivity, good storability, high color reproducibility with 'less color contamination, and other photographic characteristics.
• This invention relates to a light-sensitive material of the silver halide type exhibiting an excellent supersensitizing effect. More particularly, the invention relates to a photographic material of the silver halide type which has a high green sensitivity and is highly supersensitized to light of the green portion of the spectrum.
• the inherent sensitivity of silver halide emulsions is confined to short wavelength regions, namely ultraviolet and blue regions of the spectrum. It is known that the sensitivity of silver halide emulsions can be extended effectively by the use of certain dyes of the cyanine or merocyanine type. It is also known that when, in combination with such sensitizing dye, a certain other sensitizing dye or organic compound is incorporated into a silver halide emulsion, it is possible to impart to the emulsion a sensitivity higher than the sum of the individual effects of these sensitizing materials. Such effect is called supersensitizing effect.
• the spectral sensitization can be attained properly in the intended portion of the spectrum.
• the sensitizing material to be added does not cause such a reaction with other photographic additives as will result in bad influences to the quality of the resulting photographic material, and photographic charac- United States Patent 0 teristics of a photosensitive film or paper can be retained during storage stably.
• the supersensitizing method When the supersensitizing method is applied to greensensitized emulsions for use in preparing light-sensitive materials for color photography, it is especially important that these requirements will be satisfied. More specifically, it is desired that the emulsions have a sensitized spectrum portion optimum to exhibit a good color reproducibility as materials for color photography and have a green sensitivity of a high speed with less color contamination. Although various combinations of sensitizing dyes have been heretofore proposed to provide supersensitized silver halide emulsions, most of them fail to satisfy the above requirements sufficiently.
• Another object of this invention is to provide a combination of sensitizing dyes which gives such excellent supersensitized photographic material of the silver halide type.
• Still another object of this invention is to give a green sensitivity of a high speed to a silverhalide emulsion.
• a photographic material of the silver halide type which comprises a silver halide photographic emulsion and, incorporated therein, a combination of at least One member selected from compounds expressed by the above general ject having a specific reflective spectrum or to effect the photographing under a specific light source.
• the sensitizing compounds of the above formulae (I) and (II) do not cause such a reaction with additives contained in photographic emulsions as will affect 5 formula (I) with at least one member selected from combadly addltlfes resPltmg photographlc pounds expressed by the above general formula (II)
• a silver halide emulsion comprising the sensitizing In the photographic material of this invention compriscompounds f i gfq g ls g on g. substrat?
• These compounds may be synthesized by methods disclosed in French Pat. 1,108,788 Specification, Japanese Patent Publication 13,821/68, etc.
• Silver halide light-sensitive materials of this invention which have excellent photographic characteristics such as mentioned above, may be effectively applied to not only high speed black-and-white emulsion but also color lightsensitive photography. According to this invention, it is also possible to provide coloring dye-containing lightsensitive materials for color photography by the silver dye breach method.
• the distribution of the maximum sensitization wavelength may be varied depending upon the kinds of compounds of the general formulae (1) and (II) and the mixing ratio of them.
• These compounds are usually incorporated into a silver halide emulsion in the state dissolved in water or an organic solvent such as methanol and ethanol, or a mixture thereof. They may be added to the silver halide emulsion at any time during the emulsion preparation process, but it is generally preferred that the addition is effected just after the second-ripening step.
• the amounts added of the compounds of the general formulae (I) and (II) vary depending upon the kind of the silver halide emulsion, but in general it is preferred that they are added in such amounts that the sum of them is l to 500 mg. per mole of the silver halide. It is also preferred that the mixing ratio of both the compounds is within a range of from 1:10 to :1.
• Emulsions of any of silver chloride, silver chloridebromide, silver bromide, silver iodide-bromide and silver iodide-chloride-bromide may be used as the silver halide emulsion in this invention. It is permissible that these emulsions may be sensitized by noble metal sensitizers,
• these emulsions may further comprise additives such as stabilizers, surfactants and hardening agents.
• Example 1 A high speed emulsion of the silver iodide-bromide type containing 3 mole percent of silver iodide was prepared by efiecting the second-ripening by the gold sensitizing and sulfur sensitizing methods. Compounds of formulae (I) and (H) were added to the emulsion individually or in combination as indicated in Table 1 given below. Each compound was incorporated in the form of a 0.1% methanol solution.
• Each emulsion was maintained at about 40 C. for 20 minutes to stabilize the spectral sensitivity, and then it was uniformly coated on a cellulose triacetate film substrate and dried to obtain a sample.
• Each emulsion was immediately coated on a polyethylene terephthalate film substrate and dried to obtain an as-coated sample. Then, the as-coated sample was allowed to stand still at 50 C. for 3 days in a relative humidity of 80% to obtain a preserved sample for testing the storability under high temperature and high humidity conditions.
• Example 2 Compounds of general formulae (I) and (II) were added in a combination, as illustrated in Table 2, to a TABLE 2 Compound of Compound of Relative speed of Formula (1)
• Formula (II) green sensitivity
• Compound Amount Compound Amount .As-coated Preserved 530'540
• Sample number Number added Number added sample sample mu (2) 120 (11) 60 165 155 185 (5) 120 (13) 90 155 155 190 (3) 120 (11; 60 160 150 190
• I 90 9
• B 90 100 85 100 1 Mg. per mole of silver helife.
• Comparative Dye (A) From the results shown in Table 2, it will readily be understood that as compared with the comparative sample, the samples according to this invention exhibit excellent spectral sensitivity and have such excellent greensensitive characteristics that the sensitivity is hardly changed on storage under severe conditions and the sensitivity to the spectral region of 530540 mp, which is essential for faithful reproduction of a human image, is extremely high.
• Example 3 A high speed emulsion of the silver iodide/bromide type for negative prints of color light-sensitive material containing 5 mole percent of silver iodide was gold-sensitized and sulfur-sensitized to effect the after-ripening, and anhydro 5,5 dichloro-3,3'-disulfopropyl-9-ethylthiocarbocyaninehydroxide was added as a red-sensitizing dye in an amount of mg. per mole of the silver halide.
• a cyan coupler formed by dissolving 4-chloro-1-hydroxy-2- n-octylnaphthoic acid under heat into dibutyl phthalate and ethyl acetate and dispersing the solution into a gelatin solution with use of sodium alkylbenzenesulfonate was added to the emulsion.
• the pH of the emulsion was adjusted to 6.3, and the emulsion was coated uniformly on a cellulose triacetate film substrate, followed by drying.
• a thin gelatin layer was formed on the above emulsion coating.
• a yellow filter layer composed of colloidal silver was further coated on the above silver halide emulsion coating.
• a yellow coupler formed by emulsifying and dispersing 2-dodecyloxybenzoyl acetoanilide in a goldsensitized and sulfur-sensitized emulsion of the silver iodide/ bromide type for negative film in the same manner as described above with respect to formation of the cyan coupler and magenta coupler, and the pH of the emulsion was adjusted to 6.8.
• the so formed yellow coupler emulsion was coated on the above yellow filter layer and dried to obtain a sample of a multi-layer light-sensitive material for color photography. The sample was exposed in the same manner as in Example 1 and developed at 22 C. for minutes with use of a color developer of the following composition:
• R and R stand for a lower alkyl group having to to 3 carbon atoms or a sulfoalkyl group;
• R designates a hydrogen atom or a lower alkyl group having 1 to 3 carbon atoms;
• Y Y Y Y and Y stand for a hydrogen or halogen atom, a lower alkyl group having 1 to 3 carbon atoms, a lower alkoxy group having 1 to 3 carbon atoms or phenyl group, or they may be atomic groups bonded together to form a naphthoxazole nucleus;
• X indicates an acid anion; and
• n is 0 or 1, with at least one member selected from compounds expressed by the following general formula (II) B4 (II) wherein R is a lower alkyl group having 1 to 3 carbon atoms, a hydroxyalkyl group, a carboxyalkyl group or a sulfoalkyl group; Z is an atomic group necessary for forming an
• Formula (II) Relative Fog speed 0! color Photo- Compound Amount Compound Amount green eontamlgraphic Sample number umber added l number added I sensitivity nation) gamma 1 Mg. per mole of the silver halide.

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• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• General Physics & Mathematics (AREA)
• Silver Salt Photography Or Processing Solution Therefor (AREA)

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Cited By (10)

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• 1971
  • 1971-09-27 JP JP46074631A patent/JPS5040662B2/ja not_active Expired
• 1972
  • 1972-09-20 US US00290512A patent/US3822136A/en not_active Expired - Lifetime
  • 1972-09-26 GB GB4430972A patent/GB1377013A/en not_active Expired

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