JPS61201233A - Silver halide photographic sensitive material and formation of extremely contrasty negative image using it - Google Patents

Abstract

PURPOSE:To form an extremely contrasty negative image having such photographic characteristics as >10 gamma, extremely high sensitivity and few black spots by imagewise exposure and development with a stable developer by incorporating a hydrazine deriv. into an emulsion layer or other hydrophilic colloidal layer. CONSTITUTION:A silver halide photographic sensitive material is obtd. by forming a silver halide emulsion layer contg. singly dispersed silver halide particles having a practically octahedral crystal form prepd. in the presence of an iridium salt added by 10<-8>-1X10<-5>mol per 1mol Ag. A hydrazine deriv. having an aliphatic or aromatic group is incorporated into the sensitive material by 10<-6>-1X10<-1>mol per 1mol silver halide. At this time, the hydrazine deriv. is incorporated into the silver halide emulsion layer. It may be incorporated into other nonphotosensitive hydrophilic colloidal layer. The sensitive material contains >=0.15mol/l sulfite ions as a preservative and gives an extremely contrasty negative image with a developer of 9.5-12.3pH.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a silver halide photographic material and a method for forming an ultra-high contrast negative image using the same. This invention relates to a silver photographic material and a method of forming ultra-high contrast negative images using the same.

(Prior art) In the field of graphic arcs, in order to improve the reproduction of continuous tone images or line images using halftone images, image formation exhibiting photographic characteristics of ultra-high contrast (especially gamma of io or higher) is required. A system is needed.

Traditionally, a special developer called a Lith developer has been used for this purpose. Lith developer contains only hydroquinone as a developing agent, and uses sulfite as a preservative in the form of an adduct with formaldehyde to keep the concentration of free sulfite ions extremely low (usually O31 mol/l or less). Therefore, the Liss current S solution has a serious drawback in that it is extremely susceptible to air oxidation and cannot be stored for more than 3 days.

Methods for obtaining high-contrast photographic properties using stable developing solutions include U.S. Pat. λ issue, same issue! , 3//,'7♂No.1, '1,272. tO6, same number ≠, 2//,? ! No. 7,
There is a method using a hydrazine derivative described in No. μ, 2≠3,732 and the like. According to this method, photographic properties with ultra-high contrast and high sensitivity can be obtained, and since it is permissible to add a high concentration of sulfite to the developer, the stability of the developer against air oxidation is better than that of the lithium developer. A dramatic improvement in comparison.

However, the above-mentioned image forming system causes not only a remarkable increase in contrast but also undesirable development such as black spots due to contagious development, which poses a serious problem in the photolithography process. Black spots are, for example, black spots that occur in areas that should be undeveloped between halftone dots, and they increase over time, especially when the photosensitive material is stored at high temperatures, or due to fatigue of the liquid over time. , occurs frequently due to a decrease in sulfite ion, which is generally used as a preservative, and an increase in the p■] value, which significantly reduces the commercial value of the photolithographic material. Therefore, great efforts are being made to improve these black spots, but the improvement of black spots is often due to sensitivity and gamma (
There has been a strong desire for a system that maintains high contrast sensitivity and improves black blemishes while reducing γ).

(Object of the Invention) Therefore, the object of the present invention is to use a stable developer to reduce γ to I.
It is an object of the present invention to provide a silver halide photographic light-sensitive material having photographic properties with extremely high contrast sensitivity exceeding 0 and less black spots, and an image forming method using the same.

(Means for Solving the Problems) The above object of the present invention is: 10 to 1 × 1 mole of Ay
at least one silver halide emulsion layer consisting of monodisperse silver halide grains having substantially octahedral crystals prepared in the presence of 10-5 mol of iridium salt, and the emulsion layer or other hydrophilic emulsion layer; A negative-working silver halide photographic light-sensitive material whose fPf characteristic is that the colloid layer contains a hydrazine derivative, and a 0.0-. Contains more than /j mol/l of sulfite ions and has a pH value of ! ~12.3
This was achieved using a method for forming ultra-high contrast negative images using a developer solution.

Examples of the hydrazine derivatives used in the present invention include hydrazine derivatives having a sulfinyl group as described in US Pat. No. 71,771, and compounds represented by the following general formula ('I').

General formula (I) R1-NHNH-CHO In the formula, R1 represents an aliphatic group or an aromatic group.

In the general formula (I), the aliphatic group represented by R1 preferably has carbon atoms/~30, particularly carbon atoms/~30.
20 straight chain, branched or cyclic alkyl groups. Here, the branched alkyl group may be cyclized to form a saturated beta term containing one or more heteroatoms therein. In addition, this alkyl group is an aryl group,
It may have a substituent such as an alkoxy group, a sulfoxy group, a sulfonamide group, or a carbonamide group.

For example, t-butyl group, n-octyl group, t-octyl group, cyclohexyl group, pyrrolidyl group, imidazolyl group,
Examples include a tetrahydrofuryl group and a morpholino group.

In the general formula (1), the aromatic group represented by R1 is a single or binary aryl group or an unsaturated heterocyclic group.

Here, the unsaturated heterocyclic group may be condensed with a monocyclic or bicyclic aryl group to form a heteroaryl group.

For example, there are benzene rings, naphthalene terms, hyridine terms, pyrimidine rings, imidazole rings, virolazole rings, quinoline rings, isoquinoline rings, benzimidazole 3Ji, thiazole rings, benzothiazole rings, etc. Among them, there are those that contain a benzene term. preferable.

Particularly preferred as R1 is an aryl group.

The aryl group or aromatic group of AR1 may have a substituent.

Typical substituents include straight chain, branched or cyclic alkyl groups (preferably those with a carbon number of up to 20), aralkyl groups (preferably monocyclic or binary groups with an alkyl moiety of up to 3 carbon atoms). ), alkoxy groups (preferably carbon numbers/-20), substituted amine groups (preferably carbon numbers/-20), substituted amine groups (preferably carbon numbers/-20),
amines substituted with ~20 alkyl groups), acylamino groups (preferably those having 2 to 30 carbon atoms), sulfonamide groups (preferably those having 1 to 30 carbon atoms)
, ureido group (preferably having carbon number/~30)
and so on.

R1 in the general formula (I) may have a ballast group commonly used in immobile photographic additives such as couplers incorporated therein. The palaste group is a group having a carbon number of r or more and is relatively inert to photography, and can be selected from, for example, an alkyl group, an alkoxy group, a phenyl group, an alkylphenyl group, a phenoxy group, an alkylphenoxy group, etc. I can do it.

R1 in the general formula (I) may have a group incorporated therein to enhance adsorption to the surface of the silver halide grains. Such adsorption groups include the groups described in US Pat.

Synthesis methods for these compounds are described in Japanese Patent Application Kokai Sho J-3-, 20-2/2012.
No., J-J-, No. 209, 22, No. 33-tt732
No. J3-203/I, etc.

In the present invention, when a hydrazine derivative is contained in a photographic light-sensitive material, it is preferably contained in a silver halide emulsion layer, but other non-photosensitive hydrophilic colloid layers (e.g., a protective layer, an intermediate layer, a filter layer, It may be included in an antihalation layer, etc.). Specifically, when the compound used is water-soluble, it is prepared as an aqueous solution, and when it is poorly water-soluble, it is prepared as a solution of water-miscible organic solvents such as alcohols, esters, and ketones, and as a hydrophilic colloid solution. It can be added to. When added to the silver halide emulsion layer, it may be added during the period from the start of chemical ripening to before coating, but it is preferably added between the end of chemical ripening and before coating. In particular, it is preferable to add it to a coating solution prepared for coating.

The content of the hydrazine derivative of the present invention includes the grain size of the silver halide emulsion, the halogen composition, the method and degree of chemical sensitization, the relationship between the layer containing the compound and the silver halide emulsion layer,
It is desirable to select the optimum amount depending on the type of antifoggant compound, etc., and testing methods for selection are well known to those skilled in the art. Usually, it is preferably used in the range of 10-6 mol to / x / 0 = mol, especially / 0-5 to ≠ × 10 -2 mol, per mol of silver halide.

Specific examples of the compound represented by general formula (I) are shown below.

However, the present invention is not limited to the following compounds.

one day ■-2 ■−≠ 1-, t I-A ■-ta J-// ■-/2 ■-/g ■- /! ■−＃ H3 l 3- i-/7 CH2CH2CH2SH -it ■ I-/ri ■-ko O -/4'- knee. 2/ ) −, 2, 2 J-, 2j I-241 ■-, 2z ■-22 ■-27 1-Koza ■−Kota Other U.S. Patent Nos.≠,’! 71. As stated in issue 2g and so on.

771 The silver halide emulsion used in the present invention may have any composition such as silver chloride, silver chlorobromide, silver iodochlorobromide, silver iodochlorobromide, etc., but it has a composition of 70 mol% or more, especially 2θ molar ratio or more. Silver halide consisting of silver bromide is preferred.

The content of silver iodide is less than /Q morti, especially o, i~! Morti is preferred.

The average grain size of the silver halide used in the present invention is preferably fine grains (for example, 0.7μ or less), especially O
l, tμ or less is preferable.

In the present invention, "monodisperse silver halide grains consisting essentially of octahedral crystals" means that the weight of the silver halide grains or the number of grains is at least 9j'% of the average grain size.
Refers to particles having a size within 110% and all or a majority of their surfaces being (///) planes.

The silver halide grains in the present invention may be obtained by any of the acid method, ammonia method, and theoetherenol method. When growing silver halide, it is preferable to control pAg and simultaneously add silver ions and halide ions.

-/I- The iridium salt used in the present invention is a water-soluble iridium salt or an iridium complex salt, such as iridium trichloride,
Iridium tetrachloride, hexachloroiridium (TII)
Potassium hexachloroiridate (■), ammonium hexachloroiridate (II), and the like.

In the present invention, the iridium salt may be added at any time before the end of the first ripening during emulsion production, but it is particularly desirable to add it during grain formation.

Gelatin is advantageously used as a binder or protective colloid in photographic emulsions, but other hydrophilic colloids can also be used. For example, gelatin derivatives, graft polymers of gelatin and other polymers, proteins such as albumin and casein; hydroxyethylcellulose,
Cellulose derivatives such as carboxymethylcellulose and cellulose sulfate esters, sugar derivatives such as sodium alginate and starch derivatives, polyvinyl alcohol, polyvinyl alcohol partial acetal, poly-N-vinylpyrrolidone, polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinyl A wide variety of synthetic hydrophilic polymeric materials can be used, such as single or copolymers of imidazole, polyvinylpyrazole, and the like.

The silver halide emulsion used in the method of the present invention does not need to be chemically sensitized, but may be chemically sensitized. Sulfur sensitization, reduction sensitization, and noble metal sensitization methods are known as methods for chemical sensitization of silver halide emulsions, and any of these methods can be used alone or in combination for chemical sensitization. Good too.

Regarding these, the above-mentioned GIafkide
3 Y or ZeIikman et al.'s book or H, Fr1eser.
Die Grundlagen der Photo
ographischen Prozesse mi
tSilberhalogeniden) Akademitssie 7 Erlaksgesellschaft (Akadem
ische Ver lagsg, esel l5ch
af t +/dit♂).

Among the noble metal sensitization methods, the gold sensitization method is a typical method and uses a gold compound, mainly a total complex salt. There is no problem in containing complex salts of noble metals other than pure metals, such as platinum, radium, and rhodium. Specific examples are U.S. Patent Co., Hiro≠r, ot
No. o, British patent tar.

It is described in the 06/ issue etc.

As the sulfur sensitizer, in addition to the sulfur compounds contained in gelatin, various sulfur compounds such as thiosulfates, thioureas, thiazoles, rhodanines, etc. can be used.

As the reduction sensitizer, stannous salts, amines, formamidine sulfinic acid, silane compounds, etc. can be used.

The photosensitive material used in the present invention is disclosed in Japanese Patent Application Laid-open No. 1983-4.20jtO, page 4tj~! for the purpose of increasing sensitivity. The sensitizing dyes described on page 3 (for example, cyanine dyes, merocyanine dyes, etc.) can be added.

These sensitizing dyes may be used alone or in combination, and combinations of sensitizing dyes are often used particularly for the purpose of supersensitization.

Along with the sensitizing dye, it is a dye that itself does not have a spectral sensitizing effect or a substance that does not substantially absorb visible light,
A substance exhibiting supersensitization may also be included in the emulsion.

Useful sensitizing dyes, dye combinations exhibiting supersensitization, and substances exhibiting supersensitization are disclosed in Research Disclosure (Res.
erch Disclosure) / 7 Volume A 17
It is described in Section 5 of page 23 (■) of TDA J (published in December 1971).

The light-sensitive material of the present invention may contain various compounds for the purpose of preventing fogging or stabilizing photographic performance during the manufacturing process, storage, or photographic processing of the light-sensitive material. That is, azoles such as benzothiazolium salts, nitroindazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobenzothiazoals, mercaptothiadiazoles, aminotriazoles, benzothiazoles, etc.
．． 2-azoles, nitrobenzotriazoles, etc.; mercazotovirimidines; mercaptotriazines; thioketo compounds, such as oxazolinthione; azaindenes, such as triazaindenes, tetraazaindenes (% l- Hydroxy substitution (' p 3r 3
a t 7) Tetrazaindenes), pentaazaindenes, etc.: Many known antifoggants or stabilizers such as benzenethiosulfonic acid, benzenesulfinic acid, benzenesulfonic acid amide, etc. Compounds can be added. Among these, preferred are benzotriazoles (eg !-methyl-benzotriazole) and nitroindazoles (eg !-nitroindazole). Further, these compounds may be included in the treatment liquid.

The photographic material of the present invention may contain an inorganic or organic hardener in the photographic emulsion layer or other hydrophilic colloid layer.

For example, chromium salts (chromium alum, chromium acetate, etc.)
, aldehydes (formaldehyde, glyoxal, geltaraldehyde, etc.), N-methylol compounds (dimethylol urea, methylol dimethyl hydantoinato), dioxane derivatives (2,3-dihydroxydioxane, etc.), activated vinyl compounds (/+3+'-trihydroxydioxane, etc.), Acryloyl-hexahydro-8-triazine, /, 3-
vinylsulfonyl-copropanol, etc.), active halogen compounds (co,≠-dichloro-t-hydroxy-8-
)! Mucohalogen acids (mucochloric acid, mucophenoxychloric acid, etc.), etc. can be used alone or in combination.

The photographic emulsion layer or other hydrophilic colloid layer of the light-sensitive material prepared using the present invention may contain coating aids, antistatic properties, smoothness improvement, milk dispersion, adhesion prevention, and improvement of photographic properties (e.g., development acceleration, high contrast). Various surfactants may be included for various purposes such as oxidation, sensitization, etc.

For example, saponins (steroids), alkylene oxide derivatives (e.g. polyethylene glycol, polyethylene glycol/polypropylene glycol condensates, polyethylene glycol alkyl ethers M or HadflJ ethylene glycol alkylaryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan esters, alkylene glycol alkylamines or amides, polyethylene oxide adducts of silicone), glycidol derivatives (e.g. alkenylsuccinic acid polyglycerides, alkylphenol polyglycerides), fatty acid esters of polyhydric alcohols,
Nonionic surfactants such as alkyl esters of sugars;
Alkyl carboxylates, alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkyl sulfates, alkyl phosphates, N-acyl-N-alkyl taurines, sulfosuccinates, sulfoalkyl poly Anionic surfactants containing acidic groups such as carboxy groups, sulfo groups, phospho groups, sulfate ester groups, and phosphate ester groups, such as oxyethylene alkyl phenyl ethers and polyoxyethylene alkyl phosphate esters. agents; amphoteric surfactants such as amino acids, aminoalkyl sulfonic acids, aminoalkyl sulfates or phosphates, alkyl betaines, amine oxides; alkylamine salts, aliphatic or aromatic μ-class ammonium salts, pyridinium, Cationic surfactants such as complex secondary ammonium salts such as imidazolium, and phosphonium or sulfonium salts containing aliphatic or heterocycles can be used.

In particular, surfactants preferably used in the present invention are polyalkylene oxides having a molecular weight of 6oo or more and described in Japanese Patent Publication No. 12.

The photographic light-sensitive material of the present invention may contain a matting agent such as silica, magnesium oxide, polymethyl methacrylate, etc. in the photographic emulsion layer and other hydrophilic colloid layers for the purpose of preventing adhesion.

The light-sensitive material used in the present invention may contain a dispersion of a water-insoluble or sparingly soluble synthetic polymer for the purpose of improving dimensional stability. For example, Al-2-kyl (meth)acrylate, alkoxyalkyl (meth)acrylate, glycidyl (meth)acrylate, (
meth)acrylamide, vinyl esters (e.g. vinyl acetate), acrylonitrile, olefins, styrene, etc. alone or in combination, or together with acrylic acid, methacrylic acid, α,β-unsaturated dicarboxylic acids, hydroxyalkyl (meth)acrylates. , sulfoalkyl (meth)acrylate, styrene sulfonic acid, and the like as monomer components can be used. For example, U.S. Pat. No. 2, 371. ．． No. 005,
Same 2,73, No. 737, same, 133゜Hiro! No. 7, No. 3, Ot2, No. 74, No. 3. ≠//, ri11
No. 3. i2s, t2o, 3゜607.290, 3. t4tj, those described in No. 7≠θ can be used.

In order to obtain ultra-high contrast and high-sensitivity photographic properties using the silver halide photosensitive material of the present invention, it is necessary to use a conventional infectious developing solution or US Pat. Gu/Ri, Ri7! It is not necessary to use a highly alkaline developer with a pH close to 73 as described in the above publication, and a stable developer can be used.

That is, the silver halide photosensitive material of the present invention contains sulfite ions as a preservative at a concentration of 0. /tamol/l or more, pH
, t-/2.3, especially pi-(/(7゜j~72.3
A sufficiently high contrast negative image can be obtained using this developer.

There are no particular limitations on the developing agent that can be used in the method of the present invention, such as dihydroxybenzenes (eg, hydroquinone), 3-pyrazolidones (eg, /-phenyl-3-pyrazolidone, ≠).

Gauge methyl-/-phenyl-3-pyrazolidone), amine phenols (for example, N-methyl-p-aminophenol), etc. can be used alone or in combination.

In particular, the silver halide photosensitive material of the present invention contains dihydroxybenzenes as a main developing agent and 3-3 as an auxiliary developing agent.
Suitable for processing with developers containing pyrazolidones or aminone enols. Preferably, in this developer, the dihydroxybenzenes are contained in an amount of 0.0 to 0.00%. J mol/l 13-Pyrazolidones or amine phenol M are used together in a range of 01 Ot mol/l or less.

Furthermore, as described in US Pat. No. 26, T, by adding amines to the developer, the development speed can be increased and the development time can be shortened.

The developer also contains alkali metal sulfites, carbonates,
Contains pH buffering agents such as borates and phosphorous M salts, development inhibitors or antifoggants such as bromides, iodides, and organic antifoggants (particularly preferably nitroindazoles or benzotriazoles). I can do it.

If necessary, water softeners, solubilizing agents, color toning agents, development accelerators, surfactants (especially preferably the aforementioned polyalkylene oxides), antifoaming agents, hardeners, and film silver stain preventive agents may be added. (for example, λ-mercaptobenzimidazole sulfonic acids, etc.).

As the fixer, one having a commonly used composition can be used. As the fixing agent, in addition to thiosulfates and thiocyanates, organic sulfur compounds known to be effective as fixing agents can be used.

The fixing solution may contain a water-soluble aluminum salt or the like as a hardening agent.

The processing temperature in the method of the present invention is normal/♂0C to so
Selected between 0c.

It is preferable to use an automatic processor for photographic processing, but according to the method of the present invention, the total processing time from when the photosensitive material is put into the automatic processor until it comes out is set to 0 seconds to /20 seconds. However, it is possible to obtain photographic characteristics with sufficient ultra-high contrast and negative gradation.

The light-sensitive material of the present invention uses a monodisperse silver halide emulsion containing a predetermined amount of iridium salt and consisting of substantially octahedral grains in combination with at least one hydrazine derivative such as a compound represented by the general formula (I). By doing so, it is possible to obtain characteristics with high sensitivity, high contrast, and few black spots that are effective in reproducing halftone images and line drawings.

The present invention will be described in detail below with reference to Examples.

Example 1 Emulsions 1 to 2 were prepared in the following manner.

[Emulsion ■]

Iridium chloride (II[
) In the presence of potash and ammonia, a silver nitrate aqueous solution, potassium iodide, and a potassium bromide aqueous solution were simultaneously added for to minutes, and by keeping the pAg at r and evening during that time, the average particle size was reduced to 0.
2! An octahedral monodisperse emulsion having an average silver iodide content of 1 molti was prepared. Further, this emulsion was washed with water in a conventional manner to remove soluble salts, gelatin was added, and chemical sensitization was performed with sodium thiosulfate to obtain emulsion (2).

[Emulsion■]

Using exactly the same method as Emulsion I, the average grain size was 0.2! An octahedral monodisperse emulsion was prepared with μ, average silver iodide content λ, and j morti. Chemical ripening was then carried out in the same manner as Emulsion I to obtain Emulsion II.

[Emulsion ■]

Emulsion ■ and iridium dichloride (I [[) 0.2. An octahedral monodisperse emulsion having an average silver iodide content of 1 molt was prepared.

Chemical ripening was then carried out in the same manner as Emulsion I to obtain Emulsion II.

[Emulsion■]

per mole of Ay in gelatin aqueous solution kept at ro 0c≠
In the presence of x/0”-7 moles of potassium iridium(III) hexachloride and ammonia, an aqueous solution of silver nitrate, potassium iodide, and potassium bromide were added simultaneously over a period of 60 minutes, during which pAg was reduced to 7.!r. A cubic monodisperse emulsion having an average grain size of 0.2 µm and an average silver iodide content of 1 mol was prepared by maintaining the emulsion at 0.2 μm.

Chemical ripening was then carried out in the same manner as Emulsion (2) to obtain Emulsion (2).

[Emulsion ■]

The average grain size is 0. ．． 2Jμ, average silver iodide content λ,! A cubic monodisperse emulsion of Morch was prepared. Chemical ripening was then carried out in the same manner as Emulsion (2) to obtain Emulsion (2).

The degree of chemical sensitization of emulsions (I), (n), (III), (■), and (V) is adjusted to obtain optimum performance, and methods for doing so are well known to those skilled in the art.

As a sensitizing dye in these silver iodobromide emulsions! .

! '-dichlorodeethyl-3,3/-bis(3-sulfoprobyl)oxacarbocyanine sodium salt, as stabilizer ≠-hydroxy-t-methyl-/, 3.
3a,7-titrazaindene, a dispersion of polyethyl acrylate, polyethylene glycol 7.3-vinylsulfonyl-λ-pro, e-nol, and the compound ■-ta were added to deposit silver on a cellulose triacetate film.
Coating was carried out so that the ratio was ty/rrL2. Each sample was subjected to fog light development and photographic properties were measured. The results are shown in Table 1. As is clear from Table 1, the sample /-3 of the present invention has better black spots than the comparative sample t~//.

Developer formulation Hydroquinone 33.0 g N-methyl-p-aminophenol // 2 sulfate 0. Ig sodium hydroxide / 3.0g potassium triphosphate 7≠, og potassium sulfite
90. Og ethynecyaminetetraacetic acid dinatrilam salt /, 0g potassium bromide Hiroshi, ogj-methylbenzotriazole 0. Ag3-diethylamino-l,
2-pronone diol /j, add 0g water /l (pH=//, J
-) -3 Goo (Example 2) Emulsion I, I[[, Compound I prepared in Example 2]
Compound 1-. Coating was carried out in exactly the same manner except that 2j was added, and after storage under forced deterioration conditions, exposure and development were carried out, and photographic performance was examined. The results are shown in Table 2. As is clear from Table 2, samples 12 and /3 of the present invention have a remarkable effect compared to comparative samples /≠~17.

Claims (2)

[Claims] (1) It has at least one silver halide emulsion layer on the support, and the emulsion layer has a density of 1×10^-^8 to 1 per mole of silver.
It consists of monodisperse silver halide grains with substantially octahedral crystals prepared in the presence of ×10^-^5 moles of iridium salt, and the emulsion layer or other hydrophilic colloid layer contains a hydrazine derivative. Characteristic silver halide photographic materials. (2) having at least one silver halide emulsion layer on the support, the emulsion layer having a density of 1×10^-^8 to 1 per mole of silver;
×10^-^ Consisting of monodispersed silver halide grains with substantially octahedral crystals prepared in the presence of 5 moles of iridium salt, the emulsion layer or other hydrophilic colloid layer contains a hydrazine derivative. Formation of an ultra-high contrast negative image, which is characterized by subjecting a silver photographic material to imagewise exposure and then developing it with a developer containing 0.15 mol/l or more of sulfite ions and having a pH of 9.5 to 12.3. Method.