JPH0558535B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a silver halide photographic material with improved latent image regression, and particularly relates to a sulfur-sensitized and spectrally sensitized silver halide material with improved latent image regression. This invention relates to a silver halide photographic material using an emulsion. (Background technology) When a silver halide photographic light-sensitive material is exposed to light,
It is well known that a latent image is formed in silver halide crystals contained in a light-sensitive material, and an image is formed when this latent image is developed. If the latent image is left undeveloped, the latent image gradually regresses, resulting in lower photographic sensitivity and lower image density. The latent image is composed of fine aggregates of silver atoms (for example, as described in The Theory of the Photographic Process by TH James).
The photographic process) 4th edition, Chapter 4) is oxidized and decomposed into silver ions by the action of moisture and oxygen in the air, which is thought to cause latent image regression (for example, Photographic Technology Manual Volume 1 p.33, Shashin Kogyo Publishing (1977)
). Various methods have already been attempted to improve latent image regression. For example, German patent
Examples include the use of a hydroxyl-substituted aromatic compound as described in No. 1107508, the use of nitrilotriacetic acid and the like as described in US Pat. No. 3,318,702, the method described in US Pat. No. 3,424,583, and the method described in German Patent No. 1,173,339. However, according to the results of research conducted by the present inventors, the latent image regression of light-sensitive materials using sulfur-sensitized and spectrally sensitized silver halide emulsions is particularly large; It has become clear that latent image regression is difficult to prevent. (Objective of the Invention) An object of the present invention is to provide a photographic material using a sulfur-sensitized and spectrally sensitized silver halide emulsion, which has excellent latent image storage stability. (Structure of the Invention) The object of the present invention has been achieved by a silver halide photographic light-sensitive material prepared by adding a formamidine sulfinic acid compound to a silver halide emulsion that has been subjected to sulfur sensitization and spectral sensitization. As formamidine sulfinic acids, U.S. Patent Nos. 2983609, 2983610, 3062652,
The same compounds used as reduction sensitizers or fogging agents for direct positive silver halide light-sensitive materials can be used in British Patent No. 789823 and the like. That is, formamidine sulfinic acids represented by the following general formula () are used for the purpose of preventing latent image regression. In the formula, R ₁ , R ₂ , and R ₃ are each a hydrogen atom, a lower alkyl group (alkyl group having 1 to 4 carbon atoms such as a methyl group, ethyl group, or propyl group), or an aryl group (such as a phenyl group or a chlorophenyl group). , represents a heterocyclic group (benzothiazole group, piperidyl group, etc.), and M represents a hydrogen atom or an alkali metal (potassium, sodium, etc.). Specifically, (I-1) (I-2) (I-3) (I-4) (I-5) These include, but are not limited to. In the present invention, the amount of formamidine sulfinic acids used is usually per mole of silver halide.
Good effects can be obtained in the range of 10 ^-8 mol to 10 ^-4 mol, particularly 10 ^-7 mol to ^{10 -5} mol. The formamidine sulfinic acids of the present invention can be added before, during, or after the formation of silver halide grains, or before or after sulfur sensitization of silver halide grains. . Furthermore, the effect of preventing latent image regression can also be obtained by adding formamidine sulfinic acids before or after adding the sensitizing dye to the silver halide emulsion. The silver halide emulsion used in the present invention is usually prepared by mixing a water-soluble silver salt (for example, silver nitrate) solution and a water-soluble halide salt (for example, potassium bromide, sodium chloride, potassium iodide alone or a mixture thereof) solution with gelatin. It is produced by mixing in the presence of a water-soluble polymer solution such as Typical silver halides produced in this manner include silver chloride and silver bromide, as well as mixed silver halides such as silver chlorobromide, silver chloroiodobromide, and silver iodobromide. The silver halide grains may have different phases inside and on the surface, may have a multiphase structure such as a bonded structure, or may have a uniform phase throughout the grain. Moreover, they may be mixed. For example, silver chlorobromide grains having different phases may have a core or single or multiple layers within the grain that are richer in silver bromide than the average halogen composition. Furthermore, the grains may have a core or single or multiple layers that are richer in silver chloride than the average halogen composition. Therefore, the grain surface layer may be covered with a layer richer in silver bromide than the average halogen composition, or vice versa. The average grain size of the silver halide grains is preferably 2μ or less and 0.1μ or more, particularly preferably 1μ or less and 0.15μ or more. The particle size distribution may be narrow or wide. A so-called monodisperse silver halide emulsion having a narrow grain size distribution in which 90% or more, especially 95% or more of all grains are within ±40% of the average grain size in terms of grain number or weight can be used in the present invention. can. In addition, in order to satisfy the target gradation of a light-sensitive material, two or more types of monodisperse silver halide emulsions with different grain sizes are mixed in the same layer or in separate layers in emulsion layers having substantially the same color sensitivity. Can be applied in multiple layers. Furthermore, two or more types of polydisperse silver halide emulsions or a combination of a monodisperse emulsion and a polydisperse emulsion may be mixed or layered for use. The silver halide grains used in the present invention may have regular crystal shapes such as cubes, octahedrons, dodecahedrons, and dodecahedrons, or may have irregular crystal shapes such as spherical shapes. It may have an irregular crystal form, or it may have a composite form of these crystal forms. Further, tabular grains may be used, and in particular, an emulsion may be used in which tabular grains having a length/thickness ratio of 5 or more, particularly 8 or more occupy 50% or more of the total projected area of the grains. It may also be an emulsion consisting of a mixture of these various crystal forms. The photographic emulsions used in the present invention are as follows: P. Grafkide, Simi et Physique Fotografique (Published by Paul Montell, 1967), G.F.
Making and Coating Photographic Emulsions (Focal Press, 1964) (P.Glafkides, Chimie et
Physique Photographique (published by Paul Montel)
1967), Photographic by GF Duffin
Emulsion Chemistry (Focal Press, 1966),
Making and Coating Photographic by VLZelikman et al
It can be prepared using the method described in Emulsion (Focal Press, 1964). That is, any of the acidic method, neutral method, ammonia method, etc. may be used, and the method for reacting the soluble silver salt with the soluble halogen salt may be any one-sided mixing method, simultaneous mixing method, or a combination thereof. good. It is also possible to use a method in which particles are formed in an excess of silver ions (so-called back-mixing method). As one type of simultaneous mixing method, a method in which the pAg in the liquid phase in which silver halide is produced can be kept constant, that is, a so-called controlled double jet method can also be used. According to this method, a silver halide emulsion having a regular crystal shape and a nearly uniform grain size can be obtained. In the process of silver halide grain formation or physical ripening, a cadmium salt, a zinc salt, a lead salt, a thallium salt, an iridium salt or a complex salt thereof, a rhodium salt or a complex salt thereof, an iron salt or an iron complex salt, etc. may be present. Silver halide emulsions are usually subjected to physical ripening after grain formation.
It is desalted and chemically aged before being used for coating. In order to remove soluble silver salts from the emulsion before and after physical ripening, washing with nude water, flocculation sedimentation method, ultrafiltration method, etc. are used. The silver halide emulsion used in the present invention may contain a tetrasubstituted thiourea compound. The silver halide emulsion used in the present invention is sulfur sensitized. Examples of reagents for sulfur sensitization include sulfur-containing compounds obtained by reacting with active gelatin and silver, such as thiosulfate, allylthiocarbamide, thiourea, allyl isothiacyanate, cystine, p
-Toluenethiosulfonate, rhodan, mercapto compounds, etc. are used. Others: US Patent No. 1574944, US Patent No. 2410689, US Patent No. 2278947
Those described in No. 2728668, No. 3656955, etc. can also be used. The amount of these sulfur sensitizers used varies over a wide range under various conditions, but is usually preferably about 10 ^-7 to ^{10 -2} mol per mol of silver. In the present invention, these sulfur sensitizers are added to silver halide photographic emulsions by conventional methods. That is, a water-soluble compound is added as an aqueous solution, and an organic solvent-soluble compound is added as a solution in an organic solvent that is easily miscible with water, such as methanol or ethanol. In addition, there are no particular restrictions on the conditions such as pH, pAg, temperature, etc. during sulfur sensitization, but the pH value should be 4 to 9, especially 5 to 8.
is preferred, and the pAg value is preferably maintained at 5-11, particularly 6-9. Also, the temperature is 40 to 90
℃, especially 45 to 75℃ is preferred. The photographic emulsion used in the present invention is spectrally sensitized with a photographic sensitizing dye. The dye used is selected from the group of compounds represented by the following general formula (). In the present invention, Z ₁ , Z ₂ and
The methine group represented by Z ₃ may be substituted with an alkyl group such as a methyl group or an ethyl group. Further, n representing the number of methyl groups is 0, 1 or 2. When n=2, a 6-membered ring containing the central three of the five methine groups may be formed. The effects of the present invention are observed for so-called monomethine dyes, trimethine dyes and pentamethine dyes with n=0, 1 and 2, but especially with n=1
and 2, the trimethine dye and the pentamethine dye. Y ₁ and Y ₂ in the general formula () are each a benzoxazole nucleus, a naphthoxazole nucleus, a benzimidazole nucleus, a naphthimidazole nucleus, a benzothiazole nucleus, a naphthothiazole nucleus, a benzoselenazole nucleus, a naphthoselenazole nucleus, a pyridine nucleus, or Represents an atomic group sufficient to constitute a quinoline nucleus, and each represents a halogen atom such as fluorine, chlorine, bromine or iodine, a hydroxyl group, an alkyl group such as a methyl group, ethyl group, propyl group, butyl group, or a methoxy group. , an alkoxy group such as an ethoxy group, an aryl group such as a phenyl group or a hydroxyphenyl group, an alkoxycarbonyl group such as a methoxycarbonyl group or an ethoxycarbonyl group, a cyano group, a nitro group, etc. good. R ₄ and R ₅ in the general formula () are an alkyl group, an alkenyl group, or an aryl group which may be substituted with a hydroxyl group, a sulfonic acid group, or a carboxyl group, such as a methyl group, an ethyl group, or a n-propyl group. , i-propyl group, n-butyl group, hydroxymethyl group, hydroxyethyl group, hydroxypropyl group, sulfoethyl group, sulfopropyl group, sulfobutyl group, carboxymethyl group, carboxyethyl group, benzyl group, phenethyl group, propenyl group, etc. represents. (I) _n in the general formula () represents a counter ion sufficient to neutralize the charge of the molecule. Examples of cations include hydrogen ions, sodium ions, potassium ions, triethylammonium ions, and pyridinium ions, and examples of anions include:
Examples include chlorine ions, bromine ions, and iodine ions. If an inner salt is formed, such as when one of R ₄ and R ₅ contains a sulfone group, m=0 and there is no counter ion. Specific examples of the compound represented by the general formula () are shown below, but the invention is not limited thereto. -1 -2 -3 -4 -5 -6 -7 -8 -9 −10 −11 −12 −13 −14 −15 −16 −17 −18 −19 −20 −21 −22 −23 −24 −25 −26 −27 −28 −29 −30 −31 −32 In the present invention, generally well-known methods may be used to spectrally sensitize the silver halide emulsion with the compound represented by the general formula (). That is, it is carried out by dissolving a sensitizing dye represented by the general formula () in an appropriate solvent (methanol, ethanol, ethyl acetate, etc.) to obtain a solution with an appropriate concentration, and adding the solution to a silver halide emulsion. The above solution is
It is added at any step before, during or after the formation of silver halide grains. For example, it may be added during grain formation of a silver halide emulsion, during chemical ripening, after chemical ripening, or during preparation of a coating solution, and the order in which the stabilizer and antifoggant are added does not matter. Alternatively, the amount of the sensitizing dye represented by the general formula () used in the present invention, which may be added in one or more of these steps, varies over a wide range depending on the case, but usually, It can be used in a range of about 10 ^-6 to ^{10 -3} mol per mol of silver halide. Particularly preferred is 10 ^-5 to ^{10 -3}
It is in the molar range. In the present invention, the sensitizing dyes represented by the general formula () can be used alone or in combination of two or more. Further, a compound exhibiting a supersensitizing effect can also be used in combination with a sensitizing dye. Along with the sensitizing dye, the emulsion may contain a dye that itself does not have a spectral sensitizing effect or a substance that does not substantially absorb visible light and exhibits supersensitization. For example, aminostilbene compounds substituted with nitrogen-containing heterocyclic groups (e.g., U.S. Pat.
2933390 and 3635721), aromatic organic acid formaldehyde condensates (for example, those described in US Pat. No. 3743510), cadmium salts, azaindene compounds, and the like. The combinations described in US Pat. Nos. 3,615,613, 3,615,641, 3,617,295 and 3,635,721 are particularly useful. A variety of color couplers can be used in the present invention, examples of which are described in the patents listed in Research Disclosure (RD) No. 17643, -CG, cited above. As dye-forming couplers, couplers that provide the three primary colors (i.e., yellow, magenta, and cyan) in subtractive color development are important. Specific examples of diffusion-resistant 4-equivalent or 2-equivalent couplers include the aforementioned RD17643, -
In addition to the couplers described in the patents listed in Sections C and D, the following can be preferably used in the present invention: A representative example of the yellow coupler that can be used in the present invention is a hydrophobic acylacetamide coupler having a ballast group. Specific examples thereof are described in US Pat. No. 2,407,210, US Pat. No. 2,875,057, and US Pat. No. 3,265,506. In the present invention, it is preferable to use a two-equivalent yellow coupler, such as the oxygen atom separation type yellow coupler described in U.S. Pat. No. 3,408,194, U.S. Pat. −10739, U.S. Patent No. 4401752, U.S. Patent No.
No. 4326024, RD18053 (April 1979), British Patent No.
No. 1425020, West German Published Application No. 2219917, same no.
Typical examples thereof include nitrogen atom separation type yellow couplers described in Japanese Patent Nos. 2261361, 2329587, and 2433812. α-pivaloylacetanilide couplers have excellent color fastness, especially light fastness, while α-benzoylacetanilide couplers provide high color density. Magenta couplers that can be used in the present invention include hydrophobic indazolone or cyanoacetyl couplers, preferably 5-pyrazolone and pyrazoloazole couplers, which have a ballast group. The 5-pyrazolone coupler is preferably a coupler in which the 3-position is substituted with an arylamino group or an acylamino group from the viewpoint of the hue and color density of the coloring dye.
It is described in No. 2311082, No. 2343703, No. 2600788, No. 2908573, No. 3062653, No. 3152896, No. 3936015, etc. As a leaving group for a two-equivalent 5-pyrazolone coupler,
Particularly preferred are the nitrogen-absorbing type described in US Pat. No. 4,310,619 or the arylthio group described in US Pat. No. 4,351,897. Also European patent no.
The 5-pyrazolone coupler having a ballast group described in No. 73636 provides high color density. As a pyrazoloazole coupler, U.S. Patent No.
Pyrazolobenzimidazoles described in No. 3369879,
Preferably, the pyrazolo[5,1-c][1,2,4]triazoles described in U.S. Pat. No. 3,725,067, Research Disclosure 24220 (1984
(June 1984) and pyrazolotetrazoles described in JP-A-60-33552 and Research Disclosure 24230 (June 1984) and JP-A-60-33552.
Examples include pyrazolopyrazoles described in No. 43659. Imidazo[1,2-b]pyrazoles described in U.S. Pat. No. 4,500,630 are preferred from the viewpoint of low yellow side absorption of the coloring dye and light fastness.
Pyrazolo [1,5
-b][1,2,4]triazole is particularly preferred. Cyan couplers that can be used in the present invention include:
Hydrophobic, diffusion-resistant naphthol and phenolic couplers include the naphthol couplers described in U.S. Pat. No. 2,474,293, preferably U.S. Pat. A typical example is the oxygen atom dissociating type two-equivalent naphthol coupler described in the above issue. Specific examples of phenolic couplers include U.S. Patent No. 2369929, U.S. Patent No. 2801171,
It is described in No. 2772162, No. 2895826, etc. Cyan couplers that are stable against humidity and temperature are preferably used in the present invention, and a typical example thereof is a phenolic coupler having an alkyl group equal to or higher than ethyl group at the meta position of the phenol nucleus described in U.S. Pat. No. 3,772,002. Cyan coupler, US Patent No. 2772162, US Patent No. 3758308, US Patent No. 4126396,
No. 4334011, No. 4327173, West German Patent Publication No.
3329729 and European Patent No. 121365, etc., and U.S. Pat. No. 3446622 and European Patent No.
These include phenolic couplers having a phenylureido group at the 2-position and an acylamino group at the 5-position, which are described in Japanese Patent Nos. 4333999, 4451559, and 4427767. In order to correct unnecessary absorption of color pigments, it is preferable to perform masking by using a colored coupler in combination with a color photosensitive material for photographing. US Patent No.
Yellow-colored magenta couplers described in Japanese Patent Publication No. 4163670 and Japanese Patent Publication No. 57-39413, or U.S. Pat.
4004929, 4138258 and British Patent No.
Typical examples include the magenta-colored cyan coupler described in No. 1146368 and the like. Other colored couplers are described in Sections RD17643-G above. Granularity can be improved by using a coupler in which the coloring dye has an appropriate diffusibility. Examples of such couplers include magenta couplers in U.S. Pat. No. 4,366,237 and British Patent No. 2,125,570.
Also European Patent No. 96570 and West German Patent Publication No.
Specific examples of yellow, magenta or cyan couplers are described in No. 3234533. The dye-forming couplers and the special couplers described above may form dimers or more polymers. Typical examples of polymerized dye-forming couplers are described in US Pat. No. 3,151,820 and US Pat. No. 4,080,211. Specific examples of polymerized magenta couplers are given in UK Patent No. 2102173 and US Patent No.
Described in No. 4367282. Couplers that release photographically useful residues upon coupling are also preferably used in the present invention. DIR couplers that release development inhibitors are the aforementioned
The patent couplers described in RD17643, Sections ~F are useful. Preferable combinations with the present invention include the developer deactivation type represented by JP-A No. 57-151944; the timing type represented by U.S. Pat. No. 4,248,962 and JP-A-57-154234; The reaction type represented by No. 59-39653 is particularly preferred.
Developer deactivated DIR described in No. 75474, No. 59-82214, No. 59-82214, No. 59-90438, etc.
This is a reactive DIR coupler described in Japanese Patent Application No. 59-39653. In the light-sensitive material of the present invention, a coupler that releases a nucleating agent, a development accelerator, or a precursor thereof in an image form during development can be used. Specific examples of such compounds include British Patent No. 2097140;
It is described in the same No. 2131188. Particularly preferred are couplers that release a nucleating agent or the like that has an adsorption effect on silver halide; specific examples thereof include:
It is described in JP-A-59-157638 and JP-A-59-170840. Suitable supports that can be used in the present invention include, for example:
Page 28 of the aforementioned RD.No.17643 and the same, No.18716
It is described from the right column on page 647 to the left column on page 648. The color photographic material according to the present invention is as described above.
RD, No. 17643, pages 28-29 and the same, No. 18716.
651 can be developed by the usual methods described in the left column to right column. The color photographic material of the present invention is usually subjected to a water washing treatment or a stabilization treatment after development, bleach-fixing or fixing treatment. In the washing process, two or more tanks are generally used for countercurrent washing to save water. A representative example of the stabilization treatment is a multistage countercurrent stabilization treatment as described in JP-A-57-8543 instead of the water washing step. In the case of this step, 2 to 9 countercurrent baths are required.
Various compounds are added to this stabilizing bath for the purpose of stabilizing images. For example, various buffers (e.g., borates, metaborates, borax, phosphates, carbonates, potassium hydroxide, sodium hydroxide, aqueous ammonia) to adjust the membrane pH (e.g., PH 3 to 8). Typical examples include carboxylic acids, dicarboxylic acids, polycarboxylic acids, etc.) and formalin. In addition, water softeners (inorganic phosphoric acid, aminopolycarboxylic acid, organic phosphoric acid, aminopolyphosphonic acid,
phosphonocarboxylic acids, etc.), bactericidal agents (benzisothiazolinone, irithiazolone, 4-thiazolinebenzimidazole, halogenated phenols, etc.), surfactants, fluorescent brighteners, hardeners, and other additives. Alternatively, two or more of the same or different target compounds may be used in combination. Further, it is preferable to add various ammonium salts such as ammonium chloride, ammonium nitrate, ammonium sulfate, ammonium phosphate, ammonium sulfite, and ammonium thiosulfate as a membrane PH regulator after treatment. The present invention can be applied to various color photosensitive materials. Typical examples include color negative film for general use or movies, color reversal film for slides or television, color paper, color positive film, and color reversal paper. The present invention also provides research and
It can also be applied to black-and-white light-sensitive materials using a mixture of three-color couplers as described in Disclosure 17123 (July 1978). The present invention can also be applied to ordinary black-and-white photosensitive materials that utilize silver images, such as X-ray photosensitive materials, photosensitive materials for printing plate making, microphotosensitive materials, and the like. Known photographic additives that can be used in the present invention are Research Disclosure No. 17643 and No. 18716.
It is described in. The following table summarizes the information.

[Table] The present invention will be further explained below with reference to Examples. Example 1 The molar ratio of AgNO ₃ aqueous solution and KBr to NaCl is 7:3
and a mixed aqueous halogen solution were simultaneously added to an aqueous gelatin solution containing NaCl over a period of 50 minutes while stirring and maintaining the temperature at 60°C to precipitate a silver halide emulsion. After removing the soluble salts by washing with water, the emulsion was redispersed in an aqueous gelatin solution to obtain Emulsion-1. The obtained emulsion-1 had an average grain size containing 30 mol% silver chloride.
It was a 0.4μ emulsion. A sulfur-sensitized emulsion was prepared by adding 1 x 10 ^-4 mol of sodium thiosulfate per mol of silver to Emulsion-1 and chemically ripening it at 50°C for 50 minutes. This emulsion is designated as Emulsion-2. Emulsion-3 was prepared by adding 5 x 10 ^-7 mol of Compound I-1 per mol of silver to Emulsion-1 and aging at 60°C for 20 minutes. Further, Emulsion-4 was prepared by adding Compound I-1 to Emulsion-2 in an amount of 5.times.10.sup. ^-7 mol per mol of silver 20 minutes before the end of chemical ripening. Sensitizing dye-9 was added to Emulsion-1 to Emulsion-4 at 2.5×10 ^-4 mol per mol of silver halide to obtain Emulsion-5 to Emulsion-8, respectively. Furthermore, an emulsion (emulsion-9) was prepared in which the amount of compound I-1 was increased compared to emulsion-8. Table I shows the contents of these emulsions.
summarized in. The emulsion shown in Table I and the magenta coupler emulsion dispersion were coated on double-sided polyethylene laminated paper in the configuration shown in Table I to obtain coated samples No. 1 to No. 9.
The polyethylene on the coated side contains titanium dioxide as a white pigment and a trace amount of ultramarine blue. Gelatin was applied as a protective layer. The hardener for each layer is 2,4-dichloro-6-hydroxy-s-
Triazine sodium salt was used. The contents and coating amount of the coating sample are shown in the table.

【table】

【table】

[Table] That's right.
(*a) Magenta coupler (*b) Anti-fading agent (*c) Anti-fading agent Using these coated samples, gradation exposure for sensitometry was applied through a blue filter for samples 1 to 4 and a green filter for samples 5 to 9, and the samples were stored at room temperature for 3 days and developed. Immediately before, a sample was prepared that had been exposed under the same conditions as described above. These samples were developed through the following development process, and the density of the resulting images was measured. The exposure amount that gives a density 0.2 higher than the fog density is determined, and this value is taken as the sensitivity.The sensitivity difference (common logarithmic representation) caused by latent image regression is calculated from the difference between the sensitivity of the image stored at room temperature and the sensitivity of the image exposed immediately before development. Calculated. The results are shown in Table. In order to estimate the effect of improving latent image regression due to the addition of a formamidine sulfinic acid compound to the emulsion, the ratio of the sensitivity difference between the presence and absence of addition was determined. The results are shown in Table. Processing process Temperature Time Developer solution 33℃ 3.5 minutes Bleach-fix solution 33℃ 1.5 minutes Washing with water 28-35℃ 3.0 minutes Developer solution Nitrilotriacetic acid/3Na 2.0g Benzyl alcohol 15ml Diethylene glycol 10ml Na ₂ SO ₃ 2.0g KBr 0.5g Hydroxylamine Sulfate 3.0g 4-amino-3-methyl N-ethyl-N-[β-(methanesulfonamide) ethyl]-p-phenylenediamine sulfate 5.0g Na ₂ SO ₃ (monohydrate) 30g Add water Bleach-fix ammonium thiosulfate (70wt%) 150ml Na ₂ SO ₃ 15g NH ₄ [Fe (EDTA)] 55g EDTA2.2Na 4g Add water to make 1 liter (PH 6,9) )

【table】

[Table] The latent image regression of Sample 6 using a sulfur-sensitized and further spectrally sensitized emulsion is particularly large.
It's more obvious. However, the latent image regression of a sample using an emulsion in which formamidine sulfinic acid was added to this emulsion according to the present invention was small. or,
As is clear from the comparison of the ratio of sensitivity differences with and without addition of formamidine sulfuric acid (Table-
), the formamidine sulfinic acid compound is
It can be said that it acts specifically on sulfur-sensitized and color-sensitized emulsions and has the effect of preventing latent image regression. Example 2 A color multilayer coating sample 10 consisting of the first to seventh layers shown in Table V was prepared. The polyethylene on the side coated with the first layer contains titanium dioxide as a white pigment and a trace amount of ultramarine blue. The emulsion used for the first blue-sensitive layer was prepared by mixing an aqueous AgNO ₃ solution and a mixed halogen aqueous solution with a molar ratio of KBr and NaCl of 8:2, kept at 70°C, and adding it to an aqueous gelatin solution containing NaCl for 60 minutes. The silver halide emulsion was added at the same time to precipitate the silver halide emulsion. After removing soluble salts by washing with water, they were redispersed in an aqueous gelatin solution. The resulting emulsion contained 20 mol % of silver chloride and had an average grain size of 0.7 μm. This emulsion was sulfur sensitized by adding 0.5 x 10 ^-4 mol of sodium thiosulfate per mol of silver and chemically ripening at 60°C for 50 minutes to prepare Emulsion-10. Next, the yellow coupler *d was dissolved together with the antifading agent *e in a mixed solution of dibutyl phthalate (DBP) and ethyl acetate to obtain an emulsified dispersion of the coupler. The chemical structures of *d and *e are as follows. (*d) Yellow coupler (*e) Anti-fading agent A blue-sensitive layer was prepared using Emulsion 10 and this emulsion according to the structure shown in Table V. Emulsion-10 contained 3.5×10 ^-4 mol of sensitizing dye-1 per mol of silver halide. For the third layer, Emulsion-6 of Example-1 was used to prepare a green-sensitive layer with the same structure as the photosensitive layer of Example-1. As an emulsion for the fifth red-sensitive layer, Emulsion-2, which was also used in Example-1, was used, to which sensitizing dye-28 was added in an amount of 6.5×10 ^-5 mol per mol of silver halide. Next, cyan couplers *f, *g are dissolved in a mixed solution of dibutyl phthalate (DBP) and ethyl acetate together with anti-fade agent *h and ultraviolet absorbers *i, *j, *k, and sodium dodecylbenzenesulfonate is dissolved. It was emulsified and dispersed in a 10% aqueous gelatin solution. A red-sensitive layer was prepared using the above emulsion and this emulsion according to the structure shown in Table V.

【table】

[Table] (*f) Cyan coupler (*g) Cyan coupler (*h) Anti-fading agent (*i) Ultraviolet absorber (*j) Ultraviolet absorber (*k) Ultraviolet absorber Sample-11 was prepared having the same structure as shown in Table V, but differing from sample-10 only in the type of emulsion. The emulsion used in Sample-10 as an emulsion for the blue-sensitive layer was
Emulsions with the same contents were used except that 10 ^-6 of foam amidine sulfinic acid was added. Emulsion-9, which was also used in Example 1, was used as the emulsion for the green-sensitive layer. As the emulsion for the red-sensitive layer, the emulsion 4 of Example 1 to which sensitizing dye-28 was added in an amount of 6.5 x 10 ^-5 mol per mol of silver halide was used. Using sample-10 and sample-11, blue filter,
Gradation exposure was provided through a green filter and a red filter, and the temperature was increased to room temperature in the same manner as in Example 1.
The difference in sensitivity between those stored for days and those exposed immediately before development was investigated. The results are shown in the table. Sample-11 prepared according to the present invention exhibits better latent image storage stability than Comparative Sample-10 in all of the blue-sensitive layer, green-sensitive layer, and red-sensitive layer. By producing a silver halide photographic light-sensitive material using a sulfur-sensitized emulsion to which the formamidine sulfinic acid compound and spectral sensitizer shown in the above examples are added, halogenation with excellent latent image storage stability can be achieved. The object of the present invention to provide a silver photographic material has been achieved.

【table】

Claims (1)

[Claims] 1. A silver halide photographic material having a silver halide emulsion which has been subjected to sulfur sensitization and spectral sensitization and which contains a formamidine sulfinic acid compound.