JPH0475491B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a direct positive silver halide photographic light-sensitive material using an internal latent image type silver halide emulsion. The present invention also relates to a direct positive silver halide photographic light-sensitive material using an excellent internal latent image type silver halide emulsion layer. PRIOR ART It is well known that positive images can be formed directly using silver halide photographic materials without the need for reversal processing or negative photographic images. Conventionally known methods used to form positive images using direct positive silver halide photographic materials are mainly divided into two types in consideration of practical usefulness, excluding special methods. be able to. One type uses a silver halide emulsion that has been fogged in advance and uses solarization or the Herschel effect to destroy fogging nuclei (latent images) in exposed areas to obtain a positive image after development. . The other type uses an unfogged internal latent image type silver halide emulsion and performs surface development after image exposure and/or while performing fogging treatment to obtain a positive image. be. Here, the fogging treatment may be performed by exposing the entire surface to light, using a fogging agent, using a strong developer, heat treatment, etc., but usually a fogging agent is not used. It is carried out using The term "internal latent image type silver halide emulsion" refers to a silver halide emulsion which mainly has photosensitive nuclei inside the silver halide grains and forms a latent image inside the grains upon exposure. This latter type of method of directly obtaining a positive image using a silver halide emulsion generally has higher sensitivity than the former type of method, and is suitable for applications requiring high sensitivity. It is related to these. Various techniques are known to date in this technical field. For example, US Pat. No. 2,592,250,
Same No. 2456957, Same No. 2497875, Same No. 2588982,
British Patent No. 1151363, Japanese Patent Publication No. 43-29405, Japanese Patent Publication No. 47-9434, Japanese Patent Publication No. 47-9677, Japanese Patent Publication No. 47-32813,
No. 47-32814, No. 48-9727, No. 48-9717, U.S. Patent No. 3761266, U.S. Patent No. 3796577, JP
The main ones are No. 50-8524 and No. 50-38525. By using these known methods, it is possible to produce a relatively highly sensitive photographic material as a direct positive type. For details on the mechanism of direct positive image formation, see, for example, "The Theory of the Photographic Process" by Mies and James.
You can understand to some extent the process by which positive images are formed by the ``desensitizing effect of internal latent images'' as discussed on page 161 of the 3rd edition. In other words, due to the surface desensitization effect caused by the so-called internal latent image generated inside the silver halide grains by the initial image exposure, fog nucleation occurs selectively only on the surface of the unexposed silver halide grains in the non-image area. It is thought that a photographic image is formed in the unexposed areas by normal development. Hydrazine compounds and thiocarbazide derivatives are known as useful fogging agents that exhibit such a selective fogging effect. For example, hydrazine compounds described in U.S. Patent No. 2563785 and U.S. Patent No. 2588982;
Naphthylhydrazine sulfonic acid, described in British Patent No. 2604700, or sulfomethylhydrazines, described in British Patent No. 1403018, are used as fogging agents. In addition, the special public interest public
No. 17184 describes that a color positive image can be obtained using hydrazide or a hydrazine compound. However, in order to apply the method of directly forming positive images using these compounds as fogging agents to various photographic fields, technical problems remain that must be further improved. For example, in such fog development, a fog reaction by a fog agent must occur prior to the development reaction, so the induction period until development starts is shorter than in normal latent image silver development. long,
Its development is therefore considerably delayed. Therefore,
Particularly when applied to multilayer color photographic materials, there are problems such as non-uniformity of properties between layers. In addition, the maximum final concentration obtained with conventional fogging agents is also relatively low. Therefore, with conventional fogging agents, a relatively high concentration of fogging agent is required to obtain the desired fogging effect within a relatively short period of time; , various drawbacks were found. For example, it is known that when a fogging agent is contained in an emulsion, a large amount of the fogging agent dissolves into the developer, resulting in undesirable non-uniform development. Furthermore, if nitrogen gas bubbles produced by the decomposition of the fogging agent become trapped in the binder of the photosensitive material, the quality of the image will be significantly impaired.
Furthermore, when developing with a high concentration of fogging agent, there is a tendency for background areas to become discolored due to contamination by the fogging agent. Furthermore, when performing color development, the fogging agent competes with the color former and reacts with the oxidized product of the color developing agent, so if a high concentration of the fogging agent is used, the concentration of the coloring dye will be significantly reduced. In order to solve these problems, acylhydrazinophenylthiourea compounds have been proposed as fogging agents adsorbed on the surface of silver halide grains, for example, in U.S. Pat. It is disclosed that a good fogging effect can be achieved with a small amount of addition, and that it has the characteristics of having little dependence on development processing temperature. However, it has been found that when the above-mentioned compounds are included in emulsions, the storage stability of the emulsion liquid and the light-sensitive material is significantly deteriorated. In other words, when a photosensitive material is stored in a relatively high temperature or high humidity environment, the minimum density increases significantly.
The maximum density is also reduced, resulting in a significant loss in the quality of the positive image. Further, according to US Pat. No. 4,139,387, thiocarbohydrazide compounds have an effective fogging effect,
It is also disclosed that the water solubility is relatively high. However, it was recognized that this compound also has the following practical drawbacks. In other words, it has been found that the gradation of the highlight part of the obtained positive image, that is, the leg part on the photographic characteristic curve, is significantly softened, so that so-called toe-cutting tends to become worse. Such characteristics are extremely disadvantageous when creating a photographic image with a clear outline and a high contrast with a background portion such as text or line drawings. In addition to the above, various other fogging agents have been proposed, but all of them have drawbacks such as insufficient performance as a fogging agent or deterioration of performance due to heat and humidity during storage. The development of a fogging agent is desired. OBJECTS OF THE INVENTION The first object of the present invention is to provide a direct positive silver halide photographic material with good storage stability. A second object of the present invention is to provide a direct positive silver halide photographic light-sensitive material capable of producing clear images with a well-defined characteristic curve. Furthermore, the third object of the present invention is to have an excellent fogging effect, to prevent non-uniformity of development or to cause contamination;
To provide a novel fogging agent capable of forming a positive image with good stability as well as little variation due to development processing temperature or storage over time, and a direct positive silver halide photographic light-sensitive material containing the fogging agent. It is in. Structure of the Invention The present inventors have repeatedly studied the above-mentioned problems, and as a result, the above-mentioned object is to provide on a support at least one photosensitive silver halide emulsion layer containing internal latent image type silver halide grains. , a direct positive silver halide photographic light-sensitive material containing a fogging agent in at least one of the emulsion layer and/or other hydrophilic colloid layer, wherein the fogging agent is represented by the following general formula: We have discovered what can be achieved by general formula In the formula, R ₁ , R ₂ and R ₃ may be the same or different and each represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, and A is a phenylene group,

[Formula] Group also teeth

[Formula] represents a group, X represents an oxygen atom or a sulfur atom, Y represents a sulfur atom when X is an oxygen atom, and represents an oxygen atom when X is a sulfur atom. The present invention will be explained in more detail below. In the above general formula, the alkyl groups represented by R ₁ , R ₂ and R ₃ include, for example, linear or branched alkyl groups having 1 to 18 carbon atoms, and these groups include halogen atoms, alkoxy base,
It may be substituted with a carboxyl group, phenyl group, cyano group, etc., such as methyl group, ethyl group, n-butyl group, isopropyl group, octyl group, dodecyl group, trifluoromethyl group, ω-bromobutyl group, β- Examples include a methoxyethyl group, a carboxyethyl group, a benzyl group, and a phenethyl group. Further, the cycloalkyl group represented by R ₁ , R ₂ and R ₃ may be substituted, and examples of the substituent include an alkoxy group, a carboxyl group, a phenyl group, a cyano group, and a halogen atom. Examples include cyclopropyl group, cyclohexyl group, 4-chlorocyclohexyl group, and the like. Furthermore, the above R ₁ ,
The aryl group represented by R ₂ and R ₃ includes, for example, a phenyl group, a naphthyl group, etc., but these also include an alkyl group, an alkoxy group, a halogen atom,
It may be substituted with an amino group, a cyano group, a carboxyl group, etc., such as a phenyl group, tolyl group, methoxyphenyl group, chlorophenyl group, propylphenyl group, acetylaminophenyl group,
Examples include carboxyphenyl group.
Next, the phenylene group represented by A,

[Formula] group or

[Formula] The benzene ring of the group may have a substituent, and these substituents include, for example, a halogen atom (preferably a chlorine atom), an alkyl group (preferably a lower alkyl group,
For example, methyl, ethyl, t-butyl, etc.),
Examples include alkoxy groups (preferably lower alkoxy groups, such as methoxy groups and ethoxy groups). Typical specific examples of the fogging agent according to the present invention represented by the above general formula are listed below, but the present invention is not limited thereto. (Exemplary compound) The compound represented by the general formula of the present invention can be synthesized by the following method. That is, 1-acyl-2-(4-nitrophenyl)hydrazine is obtained by reacting 4-nitrophenylhydrazine with a carboxylic acid (or acid chloride or acid anhydride). This is hydrogenated using ethanol as a solvent and a catalyst to reduce it to a 4-amino derivative. The fogging agent according to the present invention is produced by deriving the 4-aminophenylhydrazine obtained above into 1-acyl-2-(4-thioisocyanate phenyl)hydrazine, and heating the mixture with the desired semicarbazide in an ethanol aqueous solvent. It can be synthesized by refluxing. There are several methods for converting the above amino group into thioisocyanate, but it is advantageous to use 1,1'-thiocarbanyldiimidazole because the reaction proceeds under mild conditions. The above semicarbazides can be easily synthesized from hydrazine and isocyanate. Further, when the fogging agent according to the present invention is a compound having the above-mentioned carboamidophenyl group or sulfoamidophenyl group as a linking group, the above-mentioned 1-acyl-2-(4-aminophenyl)hydrazine is combined with aminobenzoic acid. It can be obtained by using chloride or aminobenzenesulfonyl chloride to form the corresponding 1-acyl-2-(aminophenylamidophenyl)hydrazine, which is further induced into an isothiocyanate and reacted with semicarbazide. Another method is to protect one side of a carboxylic acid such as benzene dicarboxylic acid (terephthalic acid) by esterifying it with p-nitrophenol, etc., and converting the remaining carboxylic acid into an acid chloride. (Curtius) induced to isocyanate through rearrangement,
It can also be synthesized by first reacting with a thiosemicarbazide derivative and finally condensing with 4-aminophenylhydrazide. Next, a specific method for synthesizing the fogging agent according to the present invention will be described. Synthesis Example 1 (Synthesis of Exemplary Compound (1)) (a) 1-formyl-2-(4-nitrophenyl)
Synthesis of hydrazine intermediate, 19.2 g of 4-nitrophenylhydrazine, 8.5 g of sodium formate, 80 ml of ethanol, 400 ml of ethyl formate.
ml of formic acid and 60 ml of formic acid for 2 hours under reflux. Thereafter, the solvent was concentrated under reduced pressure, and the precipitated crystals were collected, washed with ethanol, and dried. Yield of target product: 13.1 g, melting point: 182-184°C. (b) 1-formyl-2-(4-aminophenyl)
Synthesis of hydrazine intermediate, 8 g of 1-formyl-2-(4-nitrophenyl)hydrazine was mixed with 200 ml of ethanol and 200 ml of ethyl acetate.
ml of mixed solvent, suspended in 1.0 g of palladium-carbon
was added and hydrogenated under normal pressure. The reaction solution was filtered, the solution was concentrated under reduced pressure, and the resulting crystals were collected, washed with a mixed solvent of ethanol/n-hexane, and dried. Yield of target product: 3.8g, melting point: 120-123
℃. (c) Synthesis of p-(1-formylhydrazinophenyl)isothiocyanate intermediate, dissolve 2.2 g of 1-formyl-2-(4-aminophenyl)hydrazine in 200 ml of acetone and heat at -50°C.
It was cooled to A solution of 2.7 g of 1,1'-thiocarbonyldiimidazole dissolved in 60 ml of acetone was added dropwise to this over 30 minutes. The mixture was then slowly warmed to room temperature and stirred for 1 hour. The solvent was evaporated to dryness under reduced pressure at 30° C. or lower, and 100 ml of ether was added to the residue, which was thoroughly ground. Filter the suspension, wash with 150 ml of water, and then wash with 50 ml of ether to obtain 1.8 g of the target product.
I got it. Melting point 173-177℃. (d) Synthesis of exemplified compound (1) 1.11 g of semicarbazide hydrochloride was added to 30 ml of ethanol,
Dissolve triethylamine in a mixed solution of 10 ml of water.
Added 1.01g. This solution was added to p-
1.8 g of (1-formylhydrazinophenyl)isothiocyanate was added, and the mixture was heated under reflux for 2 hours. After cooling, the reaction solution was filtered and washed with 20 ml of water and then with 20 ml of ethanol to obtain 0.95 g of the desired product. Melting point 204-205°C (decomposition). Synthesis Example 2 (Synthesis of Exemplary Compound (2)) 1.51 g of 4-phenyl semicarbazide was dispersed in a mixture of 40 ml of ethanol and 5 ml of water. To this was added 1.95 g of p-(1-formylhydrazinophenyl)isothiocyanate under a nitrogen stream, and the mixture was heated and refluxed for 2 hours. After cooling, the reaction solution was filtered and washed with 30 ml of ethanol to obtain 1.40 g of the desired product. Melting point 196-198°C (decomposition). The fogging agent according to the present invention is preferably contained in at least one emulsion layer consisting of a hydrophilic colloid layer having internal latent image type silver halide grains of a direct positive silver halide photographic light-sensitive material. It may be contained in a hydrophilic colloid layer on the same side of the support as the emulsion layer, such as a protective layer, an intermediate layer, a filter layer, an antihalation layer, etc. The amount of the fogging agent used can vary over a wide range depending on the characteristics of the silver halide emulsion used, the type of fogging agent, and the development conditions. After image exposure, the amount may be sufficient as long as it provides enough fogging action to obtain a positive image when developed with a surface developer, and it is desirable that the amount provides sufficient maximum density (for example, 1.5 or higher) after development. . Usually, the amount of the fogging agent is preferably about 10 ^-6 mol to 10 ^-2 mol, more preferably 10 ^-6 mol to 10 ^-3 mol, per 1 mol of internal latent image type silver halide. When a fogging agent is contained in the emulsion layer, the solvent for the fogging agent is usually an organic solvent that is miscible with water, such as methanol, ethanol, acetone, dimethylformamide, tetrahydrofuran, etc., used alone or in combination. sell. According to the present invention, the fogging agent according to the present invention includes:
As mentioned above, it can be contained not only in the emulsion layer containing the internal latent image type silver halide grains, but also in the hydrophilic colloid layer adjacent to the emulsion layer, such as an intermediate layer, a protective layer, a filter layer, or an antihalation layer. You can also do it. The fogging agent contained in the adjacent layer as described above flows out of the layer together with the processing solution during the development process, and penetrates into the emulsion layer containing internal latent image type silver halide grains adjacent to the layer, and the fogging agent contains the halogenated silver halide grains. It is presumed that the effect of the present invention is exerted by being adsorbed onto the surface of silver particles. Further, two or more types of fogging agents according to the present invention can be used in combination. When used in combination, it is preferable to contain them in the same hydrophilic colloid layer, but they can also be contained in separate layers. Further, when the fogging agent according to the present invention is applied to a color diffusion transfer method, it can be mixed into the image-receiving layer or sheet. In this case, the content of the fogging agent may be the same as when it is contained in the silver halide emulsion layer. The fogging agent according to the present invention can also be used in combination with conventionally known fogging agents. Specific examples of the above conventionally known useful fogging agents include hydrazine hydrochloride, phenylhydrazine hydrochloride, 4-methylphenylhydrazine hydrochloride,
-formyl-2-(4-methylphenyl)hydrazine, 1-acetyl-2-phenylhydrazine,
1-acetyl-2-(4-acetamidophenyl)
Hydrazine, 1-methylsulfonyl-2-phenylhydrazine, 1-benzoyl-2-phenylhydrazine, 1-methylsulfonyl-2-(3
-Hydrazine compounds such as phenylsulfonamidophenyl)hydrazine and formaldehyde phenylhydrazone: 3-(2-formylethyl)-
2-methylbenzothiazolium bromide, 3-
(2-formylethyl)-2-propylbenzothiazolium bromide, 3-(2-acetylethyl)
-2-benzylbenzoselenazolium bromide, 3-(2-acetylethyl-2-benzyl-
5-phenyl-benzoxazolium bromide, 2-methyl-3-[3-(phenylhydrazono)propyl]benzothiazolium bromide,
2-Methyl-3-[3-(p-tolylhydrazono)
propyl] benzothiazolium bromide, 2-
Methyl-3-[3-(p-sulfofenylhydrazono)propyl]benzothiazolium bromide, 2-Methyl-3-[3-(p-sulfofenylhydrazono)pentyl]benzothiazolium iode 1,2-dihydro-3-methyl-4-phenylpyrido [2,1-b)benzothiazolium bromide, 1,2-dihydro-3-methyl-4
-Phenylpyrido[2,1-b]-5-phenylbenzoxazolium bromide, 4,4'-ethylenebis(1,2-dihydro-3-methylpyrido[2,1-b]benzothiazolium bromide) ,
N-substituted quaternary cycloammonium salts such as 1,2-dihydro-3-methyl-4-phenylpyrido[2,1-b]benzoselenazolium bromide:
5-[1-ethylnaphtho(1,2-b)thiazolin-2-ylideneethylidene]-1-(2-phenylcarbazoyl)methyl-3-(4-sulfamoylphenyl)-2-thiohydantoin ,5-(3
-ethyl-2-benzothiazolinylidene)-3-
[4-(2-formylhydrazino)phenyl]rhodanine, 1-[4-(2-formylhydrazino)phenyl]-phenylthiourea, 1,3-bis[4-(2-formyl) hydrazino) phenyl]
Examples include thiourea. After imagewise exposure, the direct positive silver halide photographic light-sensitive material of the present invention (hereinafter referred to as the light-sensitive material of the present invention)
A positive image is directly formed by developing in the presence of a fogging agent, and any developing method can be adopted as the developing method for the photosensitive material of the present invention, but preferably a surface developing method. . This surface development processing method means processing with a developer substantially free of silver halide solvent. Common silver halide developers that can be used as a developer in the present invention include polyhydroxybenzenes such as hydroquinone, aminophenols, 3-pyrazolidones, ascorbic acid and its derivatives, reductones, and phenylenediamine. or a mixture thereof. Specifically, hydroquinone, aminophenol, N-methylaminophenol, 1-phenyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3
-pyrazolidone, 1-phenyl-4-methyl-4
-Hydroxymethyl-3-pyrazolidone, ascorbic acid, N,N-diethyl-p-phenylenediamine, diethylamino-o-toluidine, 4-
Examples include amino-3-methyl-N-ethyl-N-(β-methanesulfonamidoethyl)aniline, 4-amino-3-methyl-N-ethyl-N-(β-hydroxyethyl)aniline, and the like. These developers are included in the emulsion in advance and
It is also possible to act on silver halide during immersion in a PH aqueous solution. The developer used in the present invention may further contain specific antifoggants and development inhibitors, or these developer additives may be optionally incorporated into the layers of the silver halide photographic light-sensitive material. is also possible. Commonly useful antifoggants include:
Benzotriazoles such as 5-methylbenzotriazole; benzothiazoles; 1-
Included are heterocyclic thiones such as phenyl-5-mercaptotetrazole; aromatic and aliphatic mercapto compounds, and the like. Further, the developer can also contain a development accelerator such as a polyalkylene oxide derivative or a quaternary ammonium salt compound. The light-sensitive material of the present invention comprises at least one layer of internal latent image type silver halide emulsion. The internal latent image type silver halide emulsion according to the present invention is an emulsion having silver halide grains that mainly form a latent image inside the silver halide grains and has most of the photosensitive nuclei inside the grains. Silver halides such as silver bromide, silver chloride, silver chlorobromide, silver iodobromide, silver chloroiodobromide, and the like are included. Particularly preferably, the emulsion is prepared by exposing a portion of a sample coated on a transparent support to a light intensity scale for a defined period of time up to about 1 second so that the surface of the grains is substantially free of silver halide solvent. When developed for 4 minutes at 20°C using surface developer A as described below, which develops only the image, internal development as described below, in which another part of the same emulsion sample is exposed in the same way and develops the image inside the grain. It shows a maximum density that is not greater than 1/5 of the maximum density obtained when developing with solution B at 20° C. for 4 minutes. Preferably, the maximum density obtained with surface developer A is not more than 1/10 of the maximum density obtained with internal developer B. (Surface developer A) Metol 2.5g L-ascorbic acid 10g NaBO _{2.4H 2} O 35g KBr 1g Add water 1 (Internal developer B) Metol 2.0g Sodium sulfite (anhydrous) 90.0g Hydroquinone 8.0g Sodium carbonate water Salt 52.5g KBr 5.0g KI 0.5g Water added 1 The internal latent image type silver halide emulsion according to the present invention includes those prepared by various methods.
For example, the compound silver halide emulsions described in U.S. Pat. No. 2,592,250, or U.S. Pat.
Silver halide emulsions with internally chemically sensitized silver halide grains as described in US Pat. No. 3,567,778 or polyvalent metal ions as described in US Pat. A silver halide emulsion having built-in silver halide grains, or a silver halide emulsion in which the grain surface of silver halide grains containing a dopant as described in U.S. Pat. No. 3,761,276 is weakly chemically sensitized, or Silver halide emulsions comprising grains having a layered structure as described in JP-A-50-8524, JP-A-50-38525 and JP-A-53-2408, and other JP-A-52-156614 and JP-A-55- These include silver halide emulsions described in No. 127549. Further, in the internal latent image type silver halide emulsion according to the present invention, commonly used stabilizers, such as compounds having an azaindene ring and nitrogen-containing heterocyclic compounds having a mercapto group (typical examples include 4-hydroxy- 6-methyl-1,3,3a,
7-tetrazaindene and 1-phenyl-5-
By containing 1 mg to 10 g of mercaptotetrazole per mole of silver halide, a more stable result with a lower minimum concentration can be obtained. In addition, in the present invention, as antifoggants or stabilizers, for example, mercury compounds, triazole compounds, azaindene compounds, benzothiazolium compounds, zinc compounds, etc. may be used. Various photographic additives may optionally be added to the internal latent image type silver halide emulsion according to the present invention. For example, optical sensitizers that can be used in the present invention include cyanines, merocyanines, trinuclear or tetranuclear merocyanines, trinuclear or tetranuclear cyanines,
These optical sensitizers include styryls, homopolar cyanines, hemicyanines, oxonols, and hemioxonols, and these optical sensitizers have a basic group such as thiazoline or thiazole or Those containing a nucleus of rhodanine, thiohydantoin, oxazolidinedione, barbituric acid, thiobarbituric acid, pyrazolone, etc. are preferable, and such a nucleus includes alkyl, hydroxyalkyl, sulfoalkyl, carboxyalkyl,
It can be substituted with halogen, phenyl, cyano, alkoxy, and optionally fused with a carbocyclic or heterocyclic ring. The internal latent image type silver halide emulsion according to the present invention can be supersensitized. For information on the method of supersensitization, see, for example, "Review of the Mechanism of Supersensitization," Review of Supersensitization, Photographic Science and Engineering.
Vol. 18, page 4418 (1974). Other additives used depending on the purpose in the present invention include wetting agents such as dihydroxyalkanes, and film property improvers such as alkyl acrylate or alkyl methacrylate and acrylic acid or methacrylate. Water-dispersible particulate polymeric substances obtained by emulsion polymerization such as copolymers with acids, styrene-maleic acid copolymers, styrene-maleic anhydride half-alkyl ester copolymers, etc. are suitable; Examples of the auxiliary agent include saponin, polyethylene glycol lauryl ether, and the like. Other photographic additives include gelatin plasticizers, surfactants, ultraviolet absorbers, PH regulators, antioxidants, antistatic agents, thickeners, graininess improvers, dyes, mordants, brighteners, and development speed. The use of conditioning agents, matting agents, etc. is optional. The silver halide emulsion prepared as described above is directly applied to a support via a subbing layer, an antihalation layer, a filter layer, etc., as required, to obtain a positive silver halide photographic light-sensitive material. The light-sensitive material of the present invention can be used for color applications, in which case cyan, magenta and yellow dye-forming couplers or
Preferably, a dye image-forming substance such as a DIR compound is included. Examples of the above-mentioned yellow dye-forming couplers include benzoylacetanilide type, pivaloylacetanilide type, and two-equivalent type yellow couplers in which the carbon atom at the coupling position is substituted with a substituent that can be separated during the coupling reaction, a so-called split-off group. is useful.
As the magenta dye-forming coupler, pyrazolone type, pyrazolotriazole type, pyrazolinobenzimidazole type, indazolone type or two-equivalent type magenta couplers having a split-off group are useful. Furthermore, as cyan dye-forming couplers, phenolic, naphthol, pyrazoquinazolone, or two-equivalent cyan couplers having a split-off group are useful. In the present invention, it is useful to use ultraviolet absorbers, such as thiazolidone, benzotriazole, acrylonitrile, and benzophenone compounds, in order to prevent fading of dye images due to short-wavelength actinic rays.
326, 327, 328 (all manufactured by Ciba Geigy)
It is advantageous to use them alone or in combination. Any support can be used for the photosensitive material of the present invention, but typical supports include polyethylene terephthalate film, polycarbonate film, polystyrene film, polypropylene film, and cellulose acetate film, which are subbed-treated if necessary. , glass, Paraita paper, polyethylene laminate paper, etc. In addition to gelatin, the light-sensitive material of the present invention may contain a suitable gelatin derivative depending on the purpose. Suitable gelatin derivatives include, for example, acylated gelatin, guanidylated gelatin, carbamylated gelatin, cyanoethanolated gelatin, and esterified gelatin. In addition, in the present invention, other hydrophilic binders can be included depending on the needs. In addition to gelatin, suitable binders include colloidal albumin, agar, gum arabic, dextran, alginic acid, and acetyl-containing 10-20% % cellulose derivatives such as cellulose acetate, polyacrylamide, imidized polyacrylamide, casein, vinyl alcohol.
Vinyl alcohol polymers containing urethane carboxylic acid groups or cyanoacetyl groups such as vinylaminoacetate copolymers, polyvinyl alcohol, polyvinylpyrrolidone, hydrolyzed polyvinyl acetate, obtained by polymerization of proteins or saturated acylated proteins with monomers having vinyl groups. Contains polymers, polyvinylpyridine, polyvinylamine, polyaminoethyl methacrylate, polyethyleneamine, etc., and can be added to constituent layers of silver halide photographic materials such as emulsion layers, intermediate layers, protective layers, filter layers, and backing layers depending on the purpose. Can be added. Furthermore, the hydrophilic binder may contain appropriate plasticizers, lubricants, etc. depending on the purpose. Further, the above-mentioned constituent layers according to the present invention can be hardened with any suitable hardening agent. These hardening agents include chromium salts, zirconium salts, aldehyde types such as formaldehyde and mucohalogen acids, halotriazine types, polyepoxy compounds,
Examples include ethyleneimine hardeners, vinyl sulfone hardeners, and acryloyl hardeners. Furthermore, the light-sensitive material of the present invention allows a large number of various photographic constituent layers such as an emulsion layer, a filter layer, an intermediate layer, a protective layer, a subbing layer, a backing layer, and an antihalation layer to be provided on the support. be. In addition to the above-mentioned color photosensitive material, the photosensitive material of the present invention can also be used for color photosensitive materials.
It can be applied to various uses such as general black and white, X-ray, false color, printing, infrared, micro, silver dye bleaching, and color diffusion transfer photography. Among them, for diffusion transfer photography, it is particularly effective for systems using DRR compounds. The DRR
Compounds (dye-releasing redox compounds, Dye
Releasing Redox Compound) is, for example, a ballasted phenol (or naphthol) with a dye bound to the ortho or para position via a sulfonamide, or a compound bound to the 3-position of an indole via a sulfonamide. These are compounds that have the property of reacting with an oxidized product of a phenidone derivative during development, undergoing cross-oxidation, and then being hydrolyzed to release a diffusible dye. (Unexamined Japanese Patent Publication No. 48-33826, 51-104343
No. 54-130122, No. 57-85055, etc.) In the method using these compounds, the dye released during development is received in the image receiving area, and an image is formed there. A dye image will be obtained only at certain points. In other words, a commonly used silver halide emulsion having a surface latent image can provide a negative image, whereas an internal latent image type direct positive emulsion as shown in the present invention can provide a positive image. The present invention will be illustrated below with reference to Examples, but the embodiments of the present invention are not limited thereto. Example 1 An internal latent image type silver chloroiodobromide emulsion was prepared by a conversion method according to the method described in Example 1 of US Pat. No. 2,592,250. Separately magenta coupler-1-(2,4,6-trichlorophenyl)-
Mix and dissolve 40 g of 3-(2-chloro-5-octadecylsuccinimideanilino)5-pyrazolone, 1 g of 2,5-di-tert-octylhydroquinone, 75 g of dioctyl phthalate, and 30 g of ethyl acetate, including sodium isopropylnaphthalene sulfonate. It was added to an aqueous gelatin solution and emulsified and dispersed. This dispersion was previously spectrally sensitized with the following sensitizing dyes (Dye 1 and 2).
(contains 0.35 mol), and further contains 4-hydroxy-6
An emulsion was prepared by adding 1 g of -methyl-1,3,3a,7-tetrazaindene and 1 g of potassium 2,5-dihydroxy-4-sec-octadecylbenzenesulfonate. The fogging agent according to the present invention as shown in Table 1 below and the fogging agent for comparison below were added as a methanol solution to the emulsion prepared above, and this emulsion was coated on a resin-coated paper support and dried. did. The above coated samples were stored at a temperature of 23°C and a relative humidity of 55% for 1 day (conditions -1), at a temperature of 55°C, and at a relative humidity of 55%.
After storage for 2 days without humidity control (Condition-2) and 2 days at a temperature of 40°C and 80% relative humidity (Condition-3), imagewise exposure was applied and development was performed according to the following processing method. I processed it. Processing: Color development (3 minutes and 30 seconds) - Stop (30 seconds) - Bleach fixing (1 minute and 30 seconds) - Washing (1 minute and 30 seconds) The processing temperature was 30°C for each processing step, and each processing solution is shown below. The composition of Color developer; Potassium carbonate 25g Potassium bromide 1g Benzyl alcohol 10g Potassium sulfite 2.5g 5-Methylbenzotriazole 10mg 4-Amino-3-methyl-N-ethyl-
N'-(β-methanesulfonamidoethyl)aniline sulfate 4.5g PH (adjusted with potassium hydroxide) 12.0 Add water to make 1. Stop solution: Sodium acetate 6.7g Acetic acid 18.5g Sodium sulfite 4.5g PH 4.1 Adjust to 1 with water. Bleach-fix solution; Ammonium thiosulfate 110g Sodium bisulfite 10g Iron ammonium ethylenediaminetetraacetate
60g Diammonium ethylenediaminetetraacetate
5g Bis-thiourea 2g PH (adjust with ammonia water) 6.5 Finish to 1 with water. The results obtained are shown in Table 1 below.

【table】

[Table] In the above table, γ ₁ : represents the straight line portion γ as the tangent value of the inclination angle of the straight line connecting the two points of density 0.5 and 1.5 on the characteristic curve. γ ₂ : represents the leg γ on the characteristic curve as the tangent value of the slope of the straight line connecting the two points of minimum density +0.05 and minimum density +0.35. As shown in the above table, it was found that samples using the fogging agent of the present invention provided good positive images and exhibited excellent stability even under storage conditions of high temperature and high humidity. In other words, in samples other than the present invention using comparative fogging agents A and B, the minimum concentration increased significantly when stored at high temperature (condition-2), and the maximum concentration increased when stored at high humidity (condition-3). A significant decrease in concentration occurs. Also, a comparison fogging agent
When using B, the gradation of the leg of the characteristic curve (γ ₂ )
The tone is soft, and when stored under high temperature and high humidity, the tone softens even more and becomes difficult to cut. On the other hand, the sample according to the present invention has excellent storage stability as described above, and is also easy to cut and can obtain clear images. Example 2 A photosensitive sheet for diffusion transfer method was prepared by sequentially coating the following layers on an opaque polyethylene terephthalate film support. (1) A gelatin layer containing the following magenta dye image-forming compound. (2) Green-sensitive internal latent image type direct positive silver bromide emulsion layer. A spectrally sensitized internal latent image emulsion prepared in a manner similar to Emulsion C described in Example 1 of U.S. Pat.
A layer containing potassium -sec-octadecylbenzenesulfonate and a fogging agent (Exemplary Compound 1) according to the present invention shown in Table 2 below. (3) Gelatin protective layer Next, the fogging agent added to Layer 2 of the photosensitive sheet was changed, and Exemplified Compound (2) was used in place of Exemplified Compound (1). Agent-A and Comparative Fogging Agent-C below
An emulsion was prepared using the same composition as Layer 2 except for that, and three layers were coated on a support in the same manner as the photosensitive sheet to prepare a sample. A dye image receiving sheet was then prepared by sequentially coating the following layers on an opaque paper support. (1) Copolymer of styrene, N,N-dimethyl-N-benzyl-N-p-(methacroylaminophenyl)methylammonium chloride and divinylbenzene, gelatin and 1-phenyl-4
Image-receiving layer (2) consisting of -hydroxymethyl-4-methyl-3-pyrazolidinone Gelatin intermediate layer containing an ultraviolet absorber (3) Gelatin protective layer Each of the photosensitive sheets prepared above was subjected to imagewise exposure, and the following composition was prepared: activator solution for 15 seconds, and then passed between a pair of pressure rollers and overlapped with the above-mentioned image receiving sheet.
It was carried out in three stages: ℃, 24℃ and 33℃. (Activator solution composition) Potassium hydroxide 56.2g 5-methylbenzotriazole 7.2g 11-aminoundecanoic acid 2.0g Potassium bromide 2.0g Finish to 1 with water. After continuing the treatment with the activator solution for 3 minutes, the photosensitive sheet and image-receiving sheet were peeled off, and a magenta dye image was obtained on the image-receiving layer. Table 2 (not shown) shows the maximum and minimum densities of the color images obtained.

【table】

[Table] From the above results, it has been revealed that the fogging agent according to the present invention gives a good positive image even when used in a light-sensitive material for the diffusion transfer method, and also has excellent storage stability. That is, when the fogging agent according to the present invention is used, fluctuations (decrease in maximum density and increase in maximum density) during storage over time under high temperature and high humidity are smaller than when using comparative fogging agent-A. Furthermore, compared to the case where the comparative fogging agent-C was used, the variation in maximum density due to processing temperature was significantly smaller, and the generation of bubbles and uneven development were not observed at all when using the above-mentioned fogging agent-C. Ta. Effects of the Invention The direct positive silver halide photographic material containing the fogging agent according to the present invention can provide clear positive images with excellent maximum density, and is stable even when stored at high temperature and high humidity. Furthermore, even if the processing temperature is changed, the image density will hardly fluctuate.

Claims (1)

[Scope of Claims] 1. A support having at least one photosensitive silver halide emulsion layer containing internal latent image type silver halide grains, and at least one of the emulsion layer and/or other hydrophilic colloid layers. In a direct positive silver halide photographic material containing a fogging agent in one layer,
A direct positive silver halide photographic material, characterized in that the above-mentioned fogging agent is represented by the following general formula. general formula [In the formula, R ₁ , R ₂ and R ₃ may be the same or different and each represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, and A is a phenylene group, a [formula] group or a [formula] ] group, X represents an oxygen atom or a sulfur atom, Y represents a sulfur atom when X is an oxygen atom, and represents an oxygen atom when X is a sulfur atom. ]