JPH11190893A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the image forming method capable of forming an image high in density and low in Dmin and excellent in discriminability and storage stability in a short time by using a reducing agent represented by a specified formula. SOLUTION: The silver halide photographic sensitive material containing photosensitive silver halide, a basic metal compound hardly soluble in water, a hydrophilic binder, and a reducing agent on a support is processed after imagewise exposure or at the same time as the exposure in the following way: Overlaying a sheet containing a compound capable of executing complex forming reaction with a metal ion of the basic metal compound and containing physical development nuclei on the photographic sensitive material and heating them in the presence of water and a silver halide solvent, and thus, an image is formed. At that time, the reducing agent represented by the formula or the like is used, and in the formula, A is a carboxyl or sulfo group; R is H or halogen atom or a hydroxy or aliphatic group or the like; (m) 1, 2, 3, or 4; and (n) is 0, 1, 2, or 3 and m+n=<=4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a black-and-white image using a silver halide light-sensitive material (hereinafter also simply referred to as a light-sensitive material or a heat-developable light-sensitive material). The present invention relates to an image forming method capable of obtaining a monochrome image having excellent discrimination and excellent image storability.

[0002]

2. Description of the Related Art A heat development process in which a development process is performed by heating is known, and a process for obtaining a color image and a black and white image is known. In recent years, color images have been widely used, but black-and-white images have been widely used in the fields of medicine and printing.

As the heat-developable black-and-white light-sensitive materials in such fields, for example, "Dry Silver" and "Dry View" are widely known as heat-developable light-sensitive materials as products of 3M Company and Imation Company. The light-sensitive material mainly comprises silver halide, an organic silver salt, and a reducing agent. In this system, undeveloped silver halide and organic silver salt remain in the light-sensitive material after image formation, so that when exposed to strong light or stored for a long period of time, the residual silver halide and organic silver salt react to produce a white background. Comes to color.

[0004] Also, various methods for forming a black pigment have been proposed. JP-A-3-260645,
JP-A-4-147254 discloses a thermal development transfer type black-and-white image forming method utilizing a coupling reaction, but this method also requires a long processing time.
Also, with the aim of obtaining a high density image in a short time,
JP-A-7-209834 discloses a heat development transfer type black-and-white image forming method using a dye release reaction.
Because it is necessary to use a large amount of the dye-donating compound,
The film quality deteriorates and the cost increases. In addition, applications are limited due to a decrease in sharpness due to transfer.

In order to improve these problems, Japanese Patent Application Laid-Open No.
179458, JP-A-8-220686, etc.
Although high-density photosensitive materials with excellent sharpness and image forming methods are described, the discrimination of silver images is inferior to those of ordinary liquefaction processing,
It was found that the stain increased when the image was preserved due to insufficient fixation of the silver halide.

Further, conventional reducing agents have insufficient discrimination or insufficient development in a complexing agent sheet, so that when the image is stored, the silver halide remaining in the photosensitive material is colored. However, when an image is stored, the stain increases and there is a problem in the image storability.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for forming a black-and-white image in a short time with a high density and a low Dmin.
An object of the present invention is to provide an image forming method capable of obtaining an image excellent in discrimination and excellent image storability.

[0008]

The above object of the present invention is attained by the following constitutions.

1. A silver halide photosensitive material containing a photosensitive silver halide, a water-insoluble basic metal compound, a hydrophilic binder, and a reducing agent on a support after imagewise exposure or at the same time as the imagewise exposure. A method of forming a silver image by superimposing a film containing a compound capable of forming a complex with a metal ion constituting a compound and a sheet containing a physical development nucleus in the presence of water and a silver halide solvent. And wherein the reducing agent is represented by the following general formula (I) or (II).

[0010]

Embedded image

In the formula, A represents a carboxyl group or a sulfo group, and R represents a hydrogen atom, a halogen atom, a hydroxy group, an aliphatic group, an aromatic group, a heterocyclic group, a carboxy group, an acyl group, or a sulfonyl group. m represents an integer of 1 to 4;
Represents an integer of 0 to 3. The sum of m and n is 4 or less.

Hereinafter, the present invention will be described in detail.

First, the compounds of the general formulas (I) and (II) will be described.

In the general formulas (I) and (II), A represents a carboxyl group or a sulfo group, and R represents a hydrogen atom, a halogen atom, a hydroxy group, an aliphatic group, an aromatic group, a heterocyclic group, a carboxy group, Represents an acyl group or a sulfonyl group.
m represents an integer of 1 to 4, and n represents an integer of 0 to 3. The sum of m and n is 4 or less.

The reducing agents represented by the general formulas (I) and (II) can provide a high-density, low-Dmin image in a short time in the image forming method of the present invention, and can provide an image having a high image stability. It has excellent properties and low stain rise. Although the details of the mechanism are unknown, the developer of the present invention having a water-soluble group such as a carboxy group and a sulfo group has an increased diffusibility during thermal development of the developer, so that the development reaction in the complexing agent sheet is active. It is estimated that the image stability is excellent.

In the above general formulas (I) and (II), the aliphatic group, aromatic group and heterocyclic group represented by R may each have a substituent. As the substituent, an alkyl group substituted with a halogen atom, a halogen atom,
Cyano group, nitro group, hydroxy group, carbonyl group, oxycarbonyl group, carbamoyl group, alkoxy group, aryloxy group, heterocyclic oxy group, carbonyloxy group, urethane group, sulfonyloxy group, amino group, sulfonylamino group, sulfonyl group Famoylamino group, acylamino group, ureido group, sulfonyl group, sulfamoyl group,
Examples include an alkylthio group, an arylthio group, and a heterocyclic thio group.

In the general formulas (I) and (II), R may be different or the same, or may be bonded to each other to form a cyclic structure.

In the general formulas (I) and (II), A is preferably a sulfo group.

In the general formulas (I) and (II), R is preferably a hydrogen atom, a halogen atom, a hydroxy group or an aliphatic group.

In formulas (I) and (II), the total number of carbon atoms of R is preferably from 0 to 8, particularly preferably from 0 to 4.

Next, typical examples of the compounds represented by formulas (I) and (II) are shown below, but the present invention is not limited to these compounds.

[0022]

Embedded image

The amount of the compound represented by the general formula (I) of the present invention may vary depending on the kind of the compound, single use or combination use of two or more kinds, or kind and amount of the photosensitive silver halide used. The amount may be determined according to the mixing ratio and the like, but is preferably from 10 ⁻² to 10 mol, more preferably from 0.05 mol to 5 mol, per mol of silver halide. Particularly preferably, it is 10 ^-1 mol to 2 mol.

When the compound of the present invention is contained in a light-sensitive material, if the compound is hydrophobic, it can be dissolved in a high-boiling organic solvent, emulsified and dispersed, and then added. In addition, there is a method of dissolving and adding in water or an alkaline solution, and a method of dissolving and adding in an organic solvent such as methanol or ethanol. Preferably,
It is preferable to add it after dissolving it in water or an alkaline solution such as sodium hydroxide or potassium hydroxide. Further, the fine particles may be dispersed in a hydrophilic binder as solid fine particles.

The compounds of the present invention may be of one kind or two.
More than one species may be used in combination.

In the photothermographic material of the present invention, the added layer of the compound (I) or (II) of the present invention may be composed of layers (emulsion layer, non-photosensitive intermediate layer, undercoat layer, protective layer) constituting the photographic material.
May be added to the layer, but is preferably added to a non-photosensitive layer other than the emulsion layer.

The reducing agent of the present invention can be used in combination with a conventionally known reducing agent. The conventional reducing agent mentioned here includes a reducing agent precursor that releases the reducing agent during development.

Examples of the reducing agent which can be used in combination with the reducing agent of the present invention include, for example, US Pat.
No. 86, No. 3, 761, 270, No. 3, 764, 32
Nos. 8, 3,342,599 and 3,719,492
No., Research Disclosure 12,146
And p-phenylenediamines described in JP-A-56-27,132, JP-A-53-135,628 and JP-A-57-79,035; p-aminophenol developing agents, phosphoric amide phenol developing agents, sulfonamidoaniline developing agents, and hydrazone developing agents, phenols, sulfonamidophenols, polyhydroxybenzenes, naphthols, hydroxybisnaphthyls, There are methylenebisphenols, ascorbic acids, 1-aryl-3-pyrazolidones, hydrazones, and precursors of the above various reducing agents.

Two or more reducing agents may be used in combination.
Preferred is a combination with -aryl-3-pyrazolidone or a derivative thereof. The amount of the reducing agent to be used is generally 0.01 to 20 mol, particularly preferably 0.1 to 10 mol, per mol of silver.
Is a mole.

The photothermographic material used in the image forming method of the present invention contains photosensitive silver halide as a constituent. Conventionally known photosensitive silver halides can be used, for example, silver chloride, silver bromide, silver iodobromide,
Silver chlorobromide and silver chloroiodobromide can be used. Among them, silver chloride and silver chlorobromide are preferable, and the chlorine content is preferably 70% or more, more preferably 80% or more. Particularly, a chlorine content of 90% or more or silver chloride is preferable.

These silver halides have a uniform composition from the inside to the surface of the grain, and have a so-called core / shell type in which the composition differs between the inside and the surface, or a multilayered structure in which the composition changes stepwise or continuously. It may be silver halide.

Further, the silver halide may be monodisperse having a relatively uniform grain size or polydisperse having a wide grain size distribution.

The shape of silver halide is cubic, spherical,
Either octahedral, dodecahedral, or tetrahedral ones having a distinct crystal habit or those having no clear crystal habit can be used. Further, for example, JP-A-58-111933 and JP-A-58-11
No. 1934, Research Disclosure 22534
And two parallel crystallographic planes, each of which has a larger area than the other crystallographic planes, as described in US Pat. One or more tabular silver halide grains can also be used.

Further, for example, US Pat. No. 2,592,25
No. 0, 3,220,613, 3,271,257
No. 3,317,322 and 3,511,622
Nos. 3,531,291 and 3,447,927
Nos. 3,761,266 and 3,703,584
Nos. 3,736,140 and 3,761,276
No., JP-A-50-8524, JP-A-50-38525,
Internal latent image type silver halide emulsions in which the grain surface is not fogged in advance described in JP-A Nos. 52-15661 and 55-127549 can also be used.

The photosensitive silver halide grains may be formed at any stage of the grain formation by using iridium, gold, rhodium,
Metal ion species such as iron and lead can be added in the form of a suitable salt.

In this case, these metal ions are generally added in a range of 10 ^-7 to 10 ^-5 mol per mol of silver.

The particle size of the photosensitive silver halide grains is usually from 0.05 to 2 μm, preferably from 0.1 to 1.0 μm.
m. Further, silver halide grains having different average grain sizes can be used together in the same photosensitive layer for gradation adjustment.

Photosensitive silver halide grains are obtained by chemically sensitizing the surface of silver halide grains with a known sensitizer (eg, active gelatin, inorganic sulfur, sodium thiosulfate, thiourea dioxide, sodium chloroaurate, etc.). Is preferred. Chemical sensitization can also be performed in the presence of a nitrogen-containing heterocyclic compound or a mercapto group-containing heterocyclic compound.

The above-mentioned photosensitive silver halide grains can be appropriately subjected to spectral sensitization to blue, green, red and infrared light by a known spectral sensitizing dye. Representative sensitizing dyes include, for example, JP-A-59-180553, JP-A-60-140335, JP-A-60-263937, and JP-A-61-6523.
No. 2, No. 61-153635, No. 61-15
No. 3631, No. 62-32446, No. 63-
JP-A-61242, JP-A-63-138343, JP-A-3-163440, JP-A-4-31854,
It is described in JP-A-4-34547 and JP-A-5-45833. Further, for example, see JP-A-62-39846.
JP-A-62-86360, JP-A-62-8903
No. 7, No. 62-147450, No. 62-14
No. 7451, the sensitizing dye is 2
More than one species may be used together in a single silver halide.

The use amount of these sensitizing dyes is usually 10 ^-5 to 10 ^-2 mol per mol of silver halide. The sensitizing dye may be added in any step of the silver halide emulsion. Specifically, at the time of forming silver halide grains, at the time of removing soluble salts, before the start of chemical sensitization, at the time of chemical sensitization, or at the time of chemical sensitization. It may be any time after the end.

These light-sensitive silver halide grains and light-sensitive silver salt-forming components are used in an amount of usually 0.01 to ⁴ per m ² of the light-sensitive material.
0 g, preferably in the range of 0.05 to 25 g.

In the photothermographic material used in the image forming method of the present invention, a known organic silver salt can be used, if necessary, for the purpose of increasing sensitivity and improving developability.

Preferred organic silver salts are silver salts of long-chain aliphatic carboxylic acids, silver salts of carboxylic acids having a heterocyclic ring, and silver salts of compounds having an imino group.

The poorly water-soluble basic metal compound of the present invention includes zinc or aluminum oxides, hydroxides and basic carbonates, particularly preferably zinc oxide and zinc hydroxide.
Basic zinc carbonate. The basic metal compound that is hardly soluble in water is preferably used as solid fine particles dispersed in a hydrophilic binder. The average particle size of the fine particles is usually 0.01
To 2 μm, preferably 0.05 to 1 μm.
The content in the photosensitive material is usually 0.1 to 5 g / m ² , preferably 0.5 to 2.5 g / m ² .

The compound capable of forming a complex with the metal ion constituting the basic metal compound is contained in a sheet of a support different from the photosensitive material (hereinafter referred to as a complexing agent sheet). Preferred compounds capable of forming a complex with a metal ion are described in, for example, JP-A Nos. 62-174745, 62-187847, and 8-87097. Particularly, guanidinium salts such as picolinic acid, EDTA, and benzyliminodiacetic acid, methylguanidinium salts, tetraalkylammonium salts, and alkali metal salts are preferable. The content of the complexing agent sheet is preferably from 0.01~15g / m ^2, more preferably from 0.1 to 10 g / m ^2.

As the binder which can be used in the photothermographic material and the complexing agent sheet of the present invention, hydrophilic binders are preferable, such as ethyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene glycol (molecular weight of about 2000 or more), gelatin , Gelatin derivatives such as phthalated gelatin, cellulose derivatives, and synthetic or natural polymer substances such as starch, agar, and gum arabic.
More than one species can be used in combination.

Particularly, gelatin is preferably used, and as the gelatin, ordinary alkali-treated gelatin or acid-treated gelatin, or a gelatin derivative such as phenylcarbamoylated gelatin or phthalated gelatin is used. They can be used together. Also, a combination of the above-mentioned various gelatins and a water-soluble polymer other than gelatin is preferably used.

The amount of the binder to be used is generally 0.05 to 8 g, preferably 0.2 to 5 g, per m ^{2 of the} support in each constituent layer. The total amount of the binder on the photosensitive layer side of the photothermographic material is usually 1 to 30 g, preferably 2 to 15 g per 1 m ² of the support.

The binder is preferably hardened with a known photographic hardener. Examples of the hardener include a vinyl sulfone hardener, an aldehyde hardener, an epoxy hardener, an N-methylol hardener, and a halogen-substituted s- hardener.
And triazine-based hardeners. Further, the hardener may be a polymer hardener.

The image forming method of the present invention can form a silver image on a photosensitive material and a complexing agent sheet. It is sufficient to select whether to use the image of the photosensitive material or the image of the complexing agent sheet depending on the application. On the other hand, it is more preferable to use the image of the photosensitive section because of its versatility in view of performance such as sharpness.

Examples of the silver halide solvent of the present invention include:
Examples include compounds containing the general formula described in JP-B-7-120023. In the present invention, thiosulfates (eg, sodium thiosulfate, ammonium thiosulfate), imide compounds (eg, uracil, 5-methyluracil, 6
-Methyluracil, 6-butylthiouracil), 4-substituted thiourea compounds, organic thioether compounds, thione compounds, active methylene compounds, and mesoionic compounds are preferably used. Preferably, sodium thiosulfate, ammonium thiosulfate, uracil, 5-methyluracil, 6-
Methyluracil and 6-butylthiouracil are used. Particularly, sodium thiosulfate is preferable. In the present invention, the silver halide solvent is contained in the photosensitive material and the complexing agent sheet, and may be supplied from the outside during development. It is particularly preferable that the complexing agent sheet contains a silver halide solvent. The content of the silver halide solvent is usually from 0.01 mol to 10 mol, preferably from 0.1 mol to 5 mol, per 1 mol of silver halide.

The physical development nucleus of the present invention comprises zinc, mercury, lead,
Cadmium, iron, chromium, nickel, tin, cobalt,
Conventionally known physical development nuclei such as heavy metals such as copper, noble metals such as palladium, platinum, silver, and gold, and sulfides, selenides, and tellurides of these metals can be used. Of these, zinc, silver, sulfide of palladium and silver are preferred as physical development nuclei, and metallic silver, zinc sulfide and palladium sulfide are particularly preferred. These physical development nuclei may be used in combination. These physical development nuclei reduce the corresponding metal ions to form a metal colloidal dispersion, or mix a metal ion solution with a soluble sulfide, selenide or telluride solution to form a water-insoluble metal sulfide. , Metal selenide or metal telluride to obtain a colloidal dispersion. These physical development nuclei are contained in the complexing agent sheet, and usually 10 ^{-6 to 1} g / m ² , preferably 10 ^{-5 to} 0.1 g / m ² .
m ² are included.

In the photothermographic material and the complexing agent sheet used in the image forming method of the present invention, various additives as shown below can be used, if necessary, in addition to the above.

[Base Precursor] Compounds that decarboxylate by heating to release a basic compound (such as guanidine trichloroacetic acid), and compounds that decompose by an intramolecular nucleophilic substitution reaction to release amines, and the like. For example, JP-A-56-130745 and JP-A-59-15763
No. 7, No. 59-166943, No. 59-180537
Nos. 59-174830 and 59-195237
No. 62-108249, No. 63-97942,
No. 63-96159 and JP-A-1-68746.

[Heat Solvent] In the photothermographic material and the complexing agent sheet, a heat solvent used for accelerating the transfer of image dyes and for other purposes is liquefied during heat development to promote heat development and transfer of soluble silver complex. It is preferable that the compound is in a solid state at normal temperature.

Examples of the thermal solvent which can be used in the present invention include, for example, US Pat. Nos. 3,347,675 and 3,663.
No. 7,959, No. 3,438,776, No. 3,66
No. 6,477, Research Disclosure No. 1
7,643, JP-A-51-19525, 53-2
No. 4829, No. 53-60223, No. 58-1186
No. 40, No. 58-198038, No. 59-22955
No. 6, No. 59-68730, No. 59-84236,
Nos. 60-191251, 60-232525, 60-14241, 61-52643, and 62-
No. 78554, No. 62-42153, No. 62-47
No. 37, No. 63-53548, No. 63-161446
And compounds described in JP-A Nos. 1-222451 and 2-863.

[Development accelerator] For example, JP-A-59-177
No. 550, No. 59-111636, No. 59-1243
No. 33, No. 61-72233, No. 61-236548
And JP-A-1-152454 are useful, and compounds disclosed in JP-A-61-159542 and JP-A-1-159454 are useful.
No. 04645 and JP-A-1-110767 can also be used.

[Anti-fogging agent] For example, JP-A-62-3
No. 0248, US Patent No. 3,7
Mercapto compound-releasing compounds described in US Pat. No. 4,138,00,457, and JP-A-51-50725, JP-A-2-297548, and JP-A-2-282241.
265, thiazolythion described in JP-A-54-51821.
No. 55-142331, U.S. Pat. No. 4,137,
No. 079, triazoles described in JP-A-55-1408.
No. 83 thiosulfinic acid esters,
-46641, 59-57233, 59-57
Di- or tri-halides described in JP-A-234; thiol compounds described in JP-A-59-111636;
No. 78554, a fog inhibitor having a hydrophilic group,
The polymer fogging inhibitor described in JP-A-62-214452,
Antifoggants having a ballast group described in JP-A-62-123456.

Further, water-soluble halides (potassium bromide, potassium iodide, sodium chloride, etc.) and the like can also be used for the purpose of preventing fog and other purposes. The antifoggant can be added to any layer of the photothermographic material and the complexing agent sheet.

Various known photographic additives other than those described above can be used in the photothermographic material and the complexing agent sheet of the present invention. Examples thereof include a filter dye, a fluorescent whitening agent, an antistatic agent, and a surfactant. Agents (anionic, cationic, nonionic, fluorine-containing anions, etc.), inorganic and organic matting agents,
It can contain an ultraviolet absorber and a mordant. These are specifically described in RD (Research Disclosure) Magazine No. No. 17029, the same No. No. 29963,
JP-A Nos. 62-135825 and 64-13546
It is described in each gazette of the issue. As the mordant, a polymer containing a tertiary amine or a quaternary ammonium salt is preferably used, and examples thereof include JP-A-48-75237, JP-A-50-61228, and JP-A-50-80132.
JP-A-50-73440, JP-A-53-129034, JP-A-54-145529, and JP-A-55-14233.
No. 9, No. 56-161410, No. 59-21
Nos. 9745, 62-30249 and 62
Polymer mordants having a quaternary ammonium group described in JP-A-34159 and the like, for example, US Pat.
No. 393, JP-A-60-23851 and the like.
No. 15,124, British Patent Nos. 2,056,101, 2,093,041, JP-A-59-55436, JP-A-60-23854, JP-A-60-39644 and JP-A-60-60643. Gazette, pp. 60-11883
No. 4, No. 60-122941, No. 60-23
No. 5124, a polyvinyl imidazole mordant described in JP-A No. 47-3689, a mordant having a group having a mordant ability grafted thereon described in JP-A-47-3689, and a mordant described in JP-A-60-57836. Combination of tertiary amine mordant and quaternary ammonium mordant,
Examples include mordants having an image stabilizing group described in JP-A-63-198051 and JP-A-2-32335. Further, as a binder used for holding these mordants, for example, a hydrophilic binder such as gelatin or polyvinyl alcohol is preferably used.

These various additives can be appropriately added not only to the photosensitive layer but also to any constituent layers such as an intermediate layer, an undercoat layer, a protective layer and a backing layer.

The complexing agent sheet used in combination with the photothermographic material of the present invention comprises a support and a physical developing layer provided thereon for developing a soluble silver complex. The layer is a complexing agent sheet containing a physical development nucleus in a hydrophilic binder.

The support for the complexing agent sheet may be either a transparent support or a reflective support. More specifically, polyethylene phthalate, polypropylene, and a support obtained by adding a white pigment such as barium sulfate or titanium dioxide to a support thereof, or a paper support coated with a thermoplastic resin containing a white pigment (eg, polyethylene). Laminated paper can be used.

When a paper support is used, a support in which both sides of the paper support are coated with polyethylene is particularly preferable. In this case, at least one side (particularly preferably, the side of the complexing agent-containing layer) contains polyethylene. It preferably contains titanium oxide.

Various known additives can be added to the complexing agent sheet. Such additives include, for example, a stain inhibitor and an ultraviolet absorber (for example,
Benzophenone-based compounds, benzotriazole-based compounds, and the like described in JP-A-130735 and JP-A-61-153638, etc., fluorescent whitening agents (for example,
Diaminostilbene compounds described in JP-A-143752, compounds described in JP-A-63-147166, etc.), image stabilizers (for example, JP-A-5959 / 1988).
182785 and 61-159644), development accelerators, antifoggants (KBr, NaCl,
KI, benzotriazole derivatives and 1-phenyl-5-
Nitrogen-containing heterocyclic compounds such as mercaptotriazole derivatives, etc.), pH regulators (acid and acid precursors, base precursors, etc.), thermal solvents, organic fluorine compounds, oil droplets,
Examples thereof include a surfactant, a hardener, a polymer latex (for example, described in JP-A-61-156045), a matting agent, and various transition metal ions.

The above-mentioned complexing agent sheet can have a so-called back layer in order to balance the curl and improve the slipperiness. The back layer can use either a hydrophilic binder or a hydrophobic binder,
It can be appropriately selected according to the application and configuration.

The photothermographic material of the present invention may optionally have a non-photosensitive layer such as an undercoat layer, an intermediate layer, a protective layer, a filter layer, a backing layer, and a release layer in addition to the photosensitive layer. .

The photothermographic material of the present invention can be exposed by known exposure means suitable for the color sensitivity of the photosensitive material.

Exposure light sources that can be used include a tungsten lamp, a halogen lamp, a xenon lamp,
A mercury lamp, a CRT light source, a FO-CRT light source, a light emitting diode, a laser light source (for example, a gas laser, a dye laser, a YAG laser, a semiconductor laser, etc.) can be used alone or in combination. Further, a light source in which a semiconductor laser and an SHG element (second harmonic generation element) are combined can also be used.

The photothermographic material of the present invention is preferably used at 60 to 100 ° C., more preferably at 70 to 100 ° C., preferably at 1 to 100 ° C. after or simultaneously with imagewise exposure.
For 2 seconds, more preferably 2 to 60 seconds, to form a silver image on the photosensitive material or the complexing agent sheet.

In the image forming method of the present invention, a very small amount of water may be supplied to the light-sensitive material or the complexing agent sheet immediately before the heat development, and the two may be adhered to each other for heat development. In this case, the water may be simple water, or may be an alkaline aqueous solution, water containing a surfactant, the above-mentioned thermal solvent, or sulfite ion, and may be represented by the general formula (I) of the present invention. It may be water containing the compound. The amount of supply of water is preferably within the range of the maximum swelling film thickness of the photosensitive material or the image receiving material to be supplied. In addition, this water may contain a known antifungal agent, a development accelerator or an antifoggant, a fluorescent whitening agent, and the like, in addition to the additives.

In the photothermographic material of the present invention, a known heating means can be applied at the time of thermal development. For example, the photothermographic material may be brought into contact with a heated heat block or a surface heater, or may be heated with a heat roller or a heat drum. A method of contacting, a method of passing through an atmosphere maintained at a high temperature, a method of using a high-frequency heating method, or a method of providing a heat-generating conductive material such as a carbon black layer on the back surface of a photosensitive material or an image receiving member, and applying an electric current. A known thermal development system such as a system utilizing the generated Joule heat can be applied.

The heating pattern at the time of thermal development is not particularly limited, and a method of performing at a constant temperature, a method of performing initial development at a high temperature state and performing the latter half of the development at a low temperature state, or a converse method, and further increasing the temperature in three or more steps Any method such as a method of changing the area or a method of continuously changing the temperature can be used. In particular, JP-A-63-250646.
As described in the above item, in the dye release method, silver development can be performed at a low temperature in advance so that silver development occurs preferentially prior to the dye release reaction, silver development can be performed to some extent, and then heat development can be performed. .

[0074]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but embodiments of the present invention are not limited thereto.

Example 1 Preparation of Silver Halide AgCl particles having an average particle size of 0.12 μm were added to an aqueous gelatin solution. Using this emulsion as a core emulsion, a silver nitrate emulsion and an aqueous sodium chloride solution were simultaneously added while controlling pAg. Thus, a monodispersed cubic silver chloride emulsion (average particle size: 0.25 μm) was prepared. In the process of particle formation,
At the stage when the grain size became 0.20 μm, 10 ^-8 mol of potassium iridium (IV) hexachloride was added per mol of silver halide.

After desalting according to a conventional method, pAg =
Adjusted to 7.5, pH = 5.8.

Then, 3.5 per mol of silver halide was used.
mg of sodium thiosulfate was added, and the mixture was chemically ripened at an optimum point at 60 ° C., and then sensitizing dye-1 was added as a methanol solution in an amount of 15 mg per mol of silver halide. After the sensitizing dye was added, the mixture was further aged at 60 ° C. for 10 minutes, and then ST-1 was added as a stabilizer in an amount of 0.9 to 1 mol of silver halide.
g was added to terminate the chemical sensitization to obtain a silver halide emulsion.

1-phenyl-4,4'-dimethyl-3-
Preparation of Pyrazolidone Dispersion A mixed water component of 22 g of 1-phenyl-4,4'-dimethyl-3-pyrazolidone, 120 ml of a 3.7% aqueous gelatin solution and 0.7 g of a surfactant (SU-1), and further having a diameter of 0.1 g. 8mm glass beads about 18
0 g was dispersed by a sand grinder (BSG-1 / 16, manufactured by IMEX Co., Ltd.) at 2200 rpm for 1 hour.
After the dispersion, the glass beads were separated by filtration, washed with 25 ml of water, and the washing water was mixed with the dispersion. The particle size of the dispersion was about 0.5 μm.

The light-sensitive material 10 is prepared by using the above emulsions, dispersions and the like.
1 was produced. A layer having the following composition was applied to a 100 μm-thick gelatin-subbed polyethylene terephthalate. Here, the addition amount of each material is shown in an amount (g) per 1 m ^{2 of the} photothermographic material, and the photosensitive silver halide emulsion is shown in terms of silver.

First layer (basic metal compound layer insoluble in water) Alkali-treated gelatin 1.95 g Phenylcarbamoylated gelatin 0.45 g Polyvinylpyrrolidone (PVP) 0.30 g Zinc hydroxide 1.50 g Surfactant (SU -1) 0.09 g Surfactant (SU-2) 0.09 g Second layer (developer-containing layer) Alkali-treated gelatin 2.90 g Phenylcarbamoylated gelatin 0.10 g Polyvinylpyrrolidone (PVP) 0.10 g Polyethylene glycol ( (Molecular weight 2000) 0.15 g 1-phenyl-4,4'-dimethyl-3-pyrazolidone 0.27 g Surfactant (SU-1) 0.05 g Surfactant (SU-2) 0.02 g Hydroquinone 1.10 g Stable 0.36 g Third layer (emulsion layer) Alkali-treated gelatin 1.80 g Photosensitivity Silver halide emulsion 2.00 g Phenylcarbamoylated gelatin 0.30 g Polyvinylpyrrolidone (PVP) 0.15 g Surfactant (SU-1) 0.09 g Surfactant (SU-2) 0.03 g Development inhibitor 0.06 g Development inhibitor-2 0.04 g Dye-1 0.05 g Dye-2 0.02 g Fourth layer (protective layer) Alkali-treated gelatin 0.24 g Phenylcarbamoylated gelatin 0.09 g Polyvinylpyrrolidone (PVP) 0.05 g Surface activity Agent (SU-1) 0.002 g Surfactant (SU-2) 0.010 g Hardener-1 0.07 g Hardener-2 0.04 g PMMA latex (size 3 μm) 0.01 g Same as photosensitive material 101 In the same manner as in the light-sensitive materials 102 to 11 except that the reducing agent shown below was used instead of the hydroquinone in the second layer by the method described in It was produced.

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[Table 1]

The obtained photothermographic material was stored at 40 ° C. and a relative humidity of 60% for 2 days to harden to a desired hardness.

Preparation of Complexing Agent Sheet A paper support having a thickness of 120 μm and laminated on both sides with polyethylene (complexing agent-containing layer was 10
An image-receiving layer having the following composition was applied on the surface of the image-receiving material (containing titanium dioxide in an amount of 2% by weight) to prepare a complexing agent sheet 201 (the amount of addition was shown per 1 m ² of the image-receiving material).

First layer Gelatin 2.0 g Surfactant (SU-1) 0.02 g Surfactant (SU-2) 0.01 g Liquid paraffin 0.5 g ALP-108 2.8 g Second layer (physical development nuclei) Layer) Gelatin 2.0 g Surfactant (SU-1) 0.08 g Surfactant (SU-2) 0.03 g Diisodecyl phthalate (DIDP) 0.4 g Polyvinyl alcohol (PVP) 0.4 g 2-pyridinemethyliminodi Disodium acetate 2.8 g Sodium thiosulfate 0.71 g Metallic silver 0.01 g Polymer (1) 0.35 g Third layer (protective layer) Gelatin 0.45 g Polyvinyl alcohol 0.08 g Surfactant (SU-1) 09 Hardener-1 0.08 g The obtained complexing agent sheet was stored at 23 ° C for 3 days to harden to the desired degree of hardening. In addition, the film surface pH of these complexing agent sheets was 9.8.

Evaluation of Photothermographic Material The obtained photothermographic material was subjected to wedge exposure using a semiconductor laser of 786 nm, immersed in pure water for about 2 seconds, and exposed to the complexing agent-containing layer surface of the complexing agent sheet. After laminating the photosensitive layer surfaces, they were heated at 80 ° C. for 20 seconds. Subsequently, when the complexing agent sheet was peeled off, a silver image was obtained on the photosensitive material and the complexing agent sheet. Dmax and Dmin of the obtained photosensitive material
Was measured using PDA-65: Konica Corporation. Further, the obtained image was stored at 85 ° C. and a humidity of 60% for 2 days, and the density of the Dmin part was measured. Dm
Table 2 summarizes the differences between the values of ax, Dmin, and the value of Dmin after storage and immediately after storage as the amount of increase in stain.

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[Table 2]

As is apparent from the above results, the image forming method of the present invention can provide a black and white silver image having excellent discrimination and excellent image storability in a short time.

Evaluation of Complexing Agent Sheet Dmax and Dmin of the complexing agent sheet obtained by the above process
Was measured using PDA-65: manufactured by Konica Corporation. Further, the obtained image was stored at 85 ° C. and a humidity of 60% for 2 days, and the density of the Dmin part was measured. Dma
Table 3 summarizes the difference between the values of x, Dmin and Dmin immediately after storage and as the increase in stain.

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[Table 3]

It can be seen that the image forming method of the present invention provided a black and white silver image having excellent discrimination and excellent image storability even on the complexing agent sheet.

[0094]

As has been demonstrated in the examples, the image forming method according to the present invention, in a method for forming a black-and-white image, can provide an image excellent in high density and low Dmin discrimination in a short time, and It has an effect of excellent preservability.

Claims (1)

[Claims] A silver halide photosensitive material containing a photosensitive silver halide, a water-insoluble basic metal compound, a hydrophilic binder and a reducing agent on a support after imagewise exposure or simultaneously with imagewise exposure. A film containing a compound capable of forming a complex with metal ions constituting the basic metal compound and a physical development nucleus is superposed on each other, and heated in the presence of water and a silver halide solvent to form silver. A method of forming an image, comprising:
An image forming method, wherein the reducing agent is represented by the following general formula (I) or (II). Embedded image [In the formula, A represents a carboxyl group or a sulfo group, and R represents a hydrogen atom, a halogen atom, a hydroxy group, an aliphatic group, an aromatic group, a heterocyclic group, a carboxy group, an acyl group, or a sulfonyl group. m represents an integer of 1 to 4, and n represents an integer of 0 to 3. The sum of m and n is 4 or less. ]