JPH11190894A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming method with which images of a high density and excellent discrimination of low Dmin may be rapidly obtd. and further image preservation is excellent in the method for forming black and white images. SOLUTION: This image forming method forms the silver images by superposing the film surfaces of a silver halide photosensitive material including a photosensitive silver halide, a basic metal compd. hardly soluble in water, a hydrophilic binder and a reducing agent and a sheet contg. a compd. capable of making complex formation reaction with the metal ions constituting the basic metal compd. and physical development nuclei on each other after imagewise exposure or simultaneously with the imagewise exposure, then heating both in the presence of water and a silver halide solvent. In such a case, the basic metal compd. hardly soluble in the water and the compd. expressed by formula (R1 )n-Ar-Sh are incorporated into at least one layer constituting the silver halide photosensitive material. In the formula, R1 denotes an aliphat. group, arom. group, heterocyclic group, carboxyl group, acyl group and sulfonyl group and Ar denotes a carbon arom. ring or heterocyclic arom. ring.

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.

Various methods have been proposed for forming black using a dye. JP-A-3-260645
No. 4,147,254 discloses a thermal development transfer type black-and-white image forming method using a coupling reaction, but this method also requires a long processing time. In order to obtain a high-density image in a short time, Japanese Patent Application Laid-Open No. 7-209834 discloses a heat development transfer type black-and-white image forming method using a dye release reaction. Since it is necessary to minimize the amount and increase the amount of the dye-donating compound used, 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 Laid-Open No.
-295176, JP-A-8-179458, 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.

[0006]

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 further preserving an image.

[0007]

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

[0008] 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 surface with a sheet containing a compound capable of forming a complex with a metal ion constituting the compound and a physical development nucleus and heating in the presence of water and a silver halide solvent. So,
An image forming method, characterized in that at least one layer constituting a silver halide light-sensitive material contains the water-insoluble basic metal compound and the compound represented by the general formula (1).

Formula (1) (R ₁ ) n-Ar-SH In the formula, R ₁ represents an aliphatic group, an aromatic group, a heterocyclic group, a carboxy group, an acyl group, or a sulfonyl group, and Represents a group of 8 or more. Ar represents a carbon aromatic ring or a heteroaromatic ring. n represents an integer of 0 to 2.

[0010] 2. The image forming method according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2).

[0011]

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In the formula, Q represents an atom group necessary for forming a 5- or 6-membered heterocyclic ring composed of at least one atom of a carbon atom, a nitrogen atom, an oxygen atom and a selenium atom. The heterocyclic ring may be fused with a carbon aromatic ring or a heteroaromatic ring. L represents a heterocyclic ring or a carbon aromatic ring condensed to a heterocyclic ring or a divalent linking group substituted with a heteroaromatic ring, and B represents a ballast group having 8 or more carbon atoms. n is 0
Or represents an integer of 1.

Hereinafter, the present invention will be described in detail.

First, the compound represented by formula (1) will be described.

Formula (1) (R ₁ ) n-Ar-SH In the formula (1), R ₁ represents an aliphatic group, an aromatic group, a heterocyclic group, a carboxy group, an acyl group, a sulfonyl group, and a sulfo group. Represents a group, and represents a group having a total of 8 or more carbon atoms.
Ar represents a carbon aromatic ring or a heteroaromatic ring. n is 0-2
Represents an integer up to.

R ₁ may have a substituent. Examples of the substituent include an aliphatic group, an aromatic group, a heterocyclic group, an alkyl group substituted with a halogen atom, a halogen atom, a cyano group, a nitro group, a 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, sulfamoylamino group, acylamino group, ureido Group, a sulfonyl group, a sulfamoyl group, an alkylthio group, an arylthio group, and a heterocyclic thio group.

In the general formula (1), R ₁ is preferably substituted by a ballast group. Preferred ballast groups include the size and shape of the molecule which reduces the diffusivity of the compound represented by the general formula (1) and the silver salt (or silver complex) or is resistant to diffusion during thermal development. Organic ballast group provided, generally having at least 8 carbon atoms, more preferably 8 to 40 carbon atoms.
(Including a substituent carbon atom when having a substituent) (including those having a substituent).
More preferred ballast groups have a total carbon number of 10
The number is preferably 40 to 40, and particularly preferably 12 to 40. Also,
As the substituent represented by R ₁ , a carboxylic acid group or a sulfonic acid group is preferably not substituted.

Preferred specific examples of the ballast group used in the general formula (1) of the present invention are shown below.

[0019]

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The compound represented by the general formula (1) is preferably a compound represented by the following general formula (2).

[0021]

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In the general formula (2), Q represents an atom group necessary for forming a 5- or 6-membered heterocyclic ring composed of at least one atom of a carbon atom, a nitrogen atom, an oxygen atom and a selenium atom. . The heterocyclic ring may be fused with a carbon aromatic ring or a heteroaromatic ring. L represents a heterocyclic ring or a carbon aromatic ring condensed to a heterocyclic ring or a divalent linking group substituted with a heteroaromatic ring, and B represents a ballast group having 8 or more carbon atoms. n represents an integer of 0 or 1.

In the general formula (2), Q represents an atomic group necessary for forming a 5- or 6-membered heterocyclic ring composed of at least one atom of a carbon atom, a nitrogen atom, an oxygen atom and a selenium atom; Examples of the heterocycle formed by C, N, and Q include heterocycles such as imidazoles, triazoles, tetrazoles, thiazoles, thiadiazoles, oxazoles, oxadiazoles, and pyrimidines. Further, these rings may form a condensed ring. These heterocycles and condensed rings each have an optionally substituted alkyl group (for example, having 1 to 6 carbon atoms).
Linear, branched alkyl groups, alkenyl groups (eg, vinyl group, allyl group, etc.) and aryl groups (eg, phenyl group, naphthyl group, etc.), nitro groups, halogen atoms (eg, chlorine atom, bromine atom, etc.), It may have a substituent such as a mercapto group and a cyano group. Particularly preferred C, N,
The heterocyclic ring constituted by Q is a triazole ring or a tetrazole ring. When a condensed ring is formed, benzoxazole, benzothiazole and purine are particularly preferable.

In the general formula (2), 2 represented by L
As the valent group, preferably, an alkylene group having 1 to 7 carbon atoms (eg, a methylene group, an ethylene group, a propylene group, etc.), an alkenylene group (eg, a vinylene group, a propenylene group), an arylene group (eg, a p-phenylene group, m −
A phenylene group, an o-phenylene group), an imino group, a carbonyl group, a sulfonyl group, an ether group, or a combination thereof (eg, an alkylenecarbonylamino group,
Aralkyleneamino group, sulfonylamino group, etc.), and more specifically, the following.

--CONH--, --SO ₂ NH--, --NHC
ONH-, -COO-, -NHCO-, -NHSO
_2- , -O-, -S-, -NR- (R is a hydrogen atom or an alkyl group) and -CO-.

The ballast group represented by B in the general formula (2) has the same meaning as that of the ballast group in the general formula (1). Further, it is preferable that a carboxylic acid group or a sulfonic acid group is not substituted as a substituent of Q and B.

Next, specific examples of the compound represented by formula (1) of the present invention are shown, but the present invention is not limited by these.

[0028]

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[0029]

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[0030]

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[0031]

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The amount of the compound represented by the general formula (1) of the present invention added to the light-sensitive material depends on the kind of the compound, a single use or a combination use of two or more kinds, or a photosensitive silver halide used. May be determined according to the type, amount, mixing ratio and the like of the compound, but is preferably from 10 ^-3 to 2 mol, more preferably from 10 ^-2 to 2 mol, per mol of silver halide. Particularly preferably, it is 10 ^-1 mol to 1.5 mol.

When the compound of the present invention is contained in a light-sensitive material, if the compound is hydrophobic, the compound can be dissolved in a high-boiling organic solvent, emulsified and dispersed, and then added. Further, it is preferably dispersed in a hydrophilic binder as solid fine particles,
The compounds of the present invention are mixed with an aqueous solution that is substantially free of organic solvents such as ethyl acetate, methanol, methyl ethyl ketone and high boiling organic solvents and may contain one or more stabilizers or grinding agents. Can be prepared. The solid dispersion is prepared by repeatedly impacting the solid with a hard inorganic grinding medium in an aqueous solution which may contain one or more stabilizers or grinding agents. As the hard inorganic grinding medium, beads such as sand, silica spheres, stainless steel, silicon carbide, glass, zirconium, zirconium oxide, alumina, and titanium are used. These bead sizes typically range from 0.25 to 3.0 mm. It is often used to reduce the particle size by using a ball mill, a media mill, an attritor mill, a jet mill, a vibration mill or the like.

The average particle size of the hydrophobic compound in the dispersion obtained as described above can be in the range conventionally obtained by this method, and is generally 0.05 to 1.
5 μm, preferably between 0.1 and 1.0 μm.

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

In the dispersion used in the present invention, a stabilizer or a dispersion aid is used. The stabilizer or dispersing aid refers to a surfactant or a hydrophilic colloid.

As the surfactant, known anionic, cationic, nonionic, betaine surfactants and fluorine surfactants can be used. For example, surfactants include alkyl carboxylate, alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, alkyl sulfate, alkyl phosphate, N-acyl-N-alkyltaurine, sulfosuccinic acid Carboxyl groups, such as esters, sulfoalkyl polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl phosphates,
Anionic surfactants containing an acidic group such as a sulfonic acid group, a phosphoric acid group, a sulfate ester group, and a phosphate ester group, or alkylamine salts, aliphatic or aromatic quaternary ammonium salts, pyridinium, imidazolium, etc. Cationic activators such as heterocyclic quaternary ammonium salts and aliphatic or heterocyclic-containing phosphonium or sulfonium salts, or saponins (steroids), alkylene oxide derivatives, glycidol derivatives, fatty acid esters of polyhydric alcohols, sugars Nonionic surfactants such as alkyl esters of the above can be used.

The hydrophilic colloid is a known water-soluble polymer,
For example, polyethylene glycol, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, polystyrene sulfonate, gelatin, derivative gelatin (phthalated gelatin, phenylcarbamoylated gelatin),
Synthetic or natural polymer substances such as cellulose derivatives (cellulose ether, cellulose ester, etc.), starch, gum arabic, pullulan, dextran, dextrin and the like are used.

In the photothermographic material of the present invention, the added layer of the compound represented by the general formula (1) of the present invention comprises layers (emulsion layer, non-photosensitive intermediate layer, subbing layer, protective layer) constituting the photographic material. Layer), but is preferably added to a non-photosensitive layer other than the emulsion layer. More preferably, it is added to the non-photosensitive layer on the support side of the emulsion layer.

The poorly water-soluble basic metal compound of the present invention is
Zinc or aluminum oxides, hydroxides and basic carbonates, particularly preferably zinc oxide, zinc hydroxide and basic zinc carbonate. The basic metal compound which is hardly soluble in water is used by dispersing it in a hydrophilic binder as solid fine particles.
The average particle size of the fine particles is usually from 0.01 to 2 μm, preferably from 0.05 to 1 μm.

The water-insoluble basic metal compound of the present invention is added to the same layer as in the above-mentioned general formula (1). When the compound of the general formula (1) and the basic metal salt which is hardly soluble in water were added to the same layer, an image having a particularly low Dmin was obtained as compared with the case where the compound was added to another layer. This is an unexpected effect, and the suppression effect was remarkably improved by containing the basic metal compound poorly soluble in water and the general formula (1) in the same layer. The addition layer of the water-insoluble basic metal compound of the present invention may be added to any of the layers constituting the photosensitive material (emulsion layer, non-photosensitive intermediate layer, undercoat layer, protective layer). Is preferably added to a non-photosensitive layer other than the emulsion layer. More preferably, it is added to the non-photosensitive layer on the support side of the emulsion layer.

The amount of the basic metal compound which is hardly soluble in water is usually 0.1 to 5 g / m ² , preferably 0.5 to 5 g / m ² .
２．５2.5 g / m ² .

As the reducing agent of the present invention, an appropriate one can be selected from conventionally known ones. The reducing agent referred to herein includes a reducing agent precursor that releases the reducing agent during development.

The reducing agents usable in the present invention include, for example, US Pat. Nos. 3,351,286 and 3,7
Nos. 61, 270, 3,764, 328, 3, 34
2,599, 3,719,492, Research Disclosure 12,146, 15,10
8, No. 15,127, and JP-A-56-27132.
Nos. 53-135628 and 57-79035, p-phenylenediamine-based and p-aminophenol-based developing agents, phosphate amidophenol-based developing agents,
Sulfonamidoaniline-based developing agents, and hydrazone-based developing agents, phenols, sulfonamidophenols, polyhydroxybenzenes, naphthols, hydroxybisnaphthyls, methylenebisphenols, ascorbic acids, 1-aryl-3-pyrazolidones, There are hydrazones, hydroxyamines and precursors of the above various reducing agents.

Two or more reducing agents may be used in combination.
A combination of -aryl-3-pyrazolidone or a derivative thereof with a hydroquinone derivative and a hydroxyamine derivative is preferred. The amount of the reducing agent to be used is 0.01 to 20 mol, particularly preferably 0.1 to 10 mol, per 1 mol of silver.

The photothermographic material used in the image forming method of the present invention contains photosensitive silver halide grains as a constituent. Conventionally known photosensitive silver halide grains can be used, and 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 halide grains have a uniform composition from the inside to the surface of the grains, and have a so-called core / shell type in which the composition differs between the inside and the surface, or a multilayer structure in which the composition changes stepwise or continuously. Silver halide.

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

The shape of the silver halide grains may be cubic, spherical, octahedral, dodecahedral, tetrahedral or the like, or those having a distinct crystal habit.
Further, for example, JP-A-58-111933 and JP-A-58-1
No. 11934, Research Disclosure 22, 5
34, have two parallel crystallographic planes, and each of these crystallographic planes is a particle having a larger area than the other crystallographic planes, wherein the particle diameter to thickness ratio is about 5:
One or more tabular silver halides can also be used.

Further, for example, US Pat.
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 can 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 the range of 10 ^-7 to 10 ^-5 mol per mol of silver.

The photosensitive silver halide grains have a particle size of usually 0.05 to 2 μm, preferably 0.1 to 1.0 μm.
m. Further, for the purpose of gradation adjustment, it is possible to use silver halides having different average grain sizes in the same photosensitive layer in combination.

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 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 the sensitivity and improving the 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 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 light-sensitive 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 in the complexing agent sheet is 0.01 to 15 g / m ² , preferably 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, for example, 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.

In particular, gelatin is preferably used. As the gelatin, ordinary alkali-treated gelatin or acid-treated gelatin, or a gelatin derivative such as phenylcarbamoylated gelatin or phthalated gelatin is used, and two or more kinds of gelatin and gelatin derivative are 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 in the photosensitive layer side of the photothermographic material support 1 m ² per 1
30 g, preferably 2 to 15 g.

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 shown below can be used, if necessary, in addition to the above.

[Base Precursor] Compounds that decarboxylate upon 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 thermal solvent used for accelerating the transfer of image dyes and for other purposes is liquefied during thermal development to promote thermal 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] In the present invention, an anti-fogging agent usually used for photographic purposes can be used in combination.
In addition, water-soluble halides (potassium bromide, potassium iodide, sodium chloride, etc.) can also be used for fog prevention 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,
An ultraviolet absorber can be contained. These are specifically described in RD (Research Disclosure) Magazine No. No. 17,029, ibid. 29,963, JP-A-62-135825 and JP-A-64-13546.

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 development 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. It is preferable not to include a dye mordant.

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.

As the exposure light source that can be used, 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., and 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, an alkaline aqueous solution, water containing a surfactant, the above-mentioned heat solvent, or sulfite ion, or represented by the general formula (1) 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, a method of performing the development at a constant temperature, a method of performing the initial development at a high temperature and performing the latter half of the development at a low temperature, or vice versa. 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 system, 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. .

[0088]

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, and this emulsion was used as a core emulsion, and 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. Subsequently, 3.5 mg of sodium thiosulfate was added per 1 mol of silver halide, and the mixture was chemically ripened at 60 ° C. to an optimum point.
Was added as a methanol solution in an amount of 15 mg per mol of silver halide. After adding the sensitizing dye, further
After ripening for one minute, ST-1 was added as a stabilizer in an amount of 0.9 g per mol of silver halide to terminate the chemical sensitization to obtain a silver halide emulsion.

Sensitizing dye-1 Structural formula-2 Preparation of dispersion of compound represented by 1-4 of the present invention 10 g of compound (1-4) of the present invention and 100 ml of a 3.7% aqueous gelatin solution and a surfactant (SU-1) 0.3 g
And about 120 g of glass beads having a diameter of 0.8 mm were dispersed by a sand grinder (BSG-1 / 16, manufactured by IMEX Co., Ltd.) at 2,200 rpm for 1 hour. After the dispersion, the glass beads were separated by filtration, and the glass beads were washed with 25 ml of water. The wash water was mixed with the dispersion and stirred to obtain a uniform dispersion. The particle size of the dispersion was about 0.5 μm.

1-phenyl-4,4'-dimethyl-3-
Preparation of Pyrazolidone Dispersion A mixed water component of 1-phenyl-4,4'-dimethyl-3-pyrazolidone (22 g), a 3.7% aqueous gelatin solution (120 ml), and a surfactant (SU-1) (0.7 g), and a diameter of 0. Approximately 180 g of 8 mm glass beads is mixed with a sand grinder (BSG-1 / 16 manufactured by Imex Co., Ltd.)
Dispersed at time 2200 revolutions. 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.

A light-sensitive material 101 was prepared using the above emulsion, a dispersion of the compound of the present invention, and the like. A layer having the following composition was coated on a 180 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 1.85 g Phenylcarbamoylated gelatin 0.35 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 Disulfohydroxyamine 2 Sodium 5.40 g Hydroquinone 0.55 g Third layer (emulsion layer) Alkali Processed gelatin 1.60 g Photosensitive silver halide emulsion 1.75 g Phenylcarbamoylated gelatin 0.34 g Polyvinylpyrrolidone (PVP) 0.15 g Surfactant (SU-1) 0.09 g Surfactant (SU-2) 03g Development inhibitor 0.06g Development inhibitor-2 0.04g Dye-1 0.05g Dye-2 0.02g Fourth layer (protective layer) Alkali-treated gelatin 0.24g Phenylcarbamoylated gelatin 0.09g Polyvinylpyrrolidone ( PVP) 0.05 g Surfactant (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 0.011 g The same method as in the case of the photosensitive material 101, except that the same amount of zinc hydroxide in the first layer was added to the second layer. The material 102 was produced.

Next, the photosensitive materials 103 and 102 were similarly changed except that the constitutions shown in Table 1 were changed.
To 112 were produced. Compound 1-4 was added in an amount of 2.5 g / m ² , and inhibitor-2 was added in an amount of 0.9 g / m ² . H-1 and H-2 are each 1.1 g per 1 m ² ,
1.0 g was added.

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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 Sodium benzyliminodiacetate 2.8 g Second layer (physical (Development nucleus 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 Benzyl imino diacetic acid Sodium 2.8 g Sodium thiosulfate 0.71 g Metallic silver 0.01 g Third layer (protective layer) Gelatin 0.45 g Polyvinyl alcohol 0.08 g Surfactant (SU-1) 0.09 g Hardener-1 0.08 g The obtained complexing agent sheet was stored at 23 ° C. for 3 days to harden to a desired degree of hardening. In addition, the film surface pH of these complexing agent sheets was 9.8.

Evaluation of the 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 surface of the complexing agent-containing layer of the complexing agent sheet. After laminating the photosensitive layer surfaces, they were heated at 85 ° C. for 15 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 increase in stain.

[0104]

[Table 2]

As is clear from Table 2, the compounds represented by the general formula (1) were replaced by inhibitors-2, H-1 and H-1.
While the photosensitive material using -2 has a low Dmax and a high Dmin, the image forming method of the present invention can provide a black-and-white silver image excellent in discrimination and image storability in a short time. You can see that.

Evaluation of complexing agent sheet Dmax and Dmin of the complexing agent sheet obtained by the above treatment
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.

[0107]

[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.

[0109]

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 (2)

[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 capable of forming a complex with a metal ion constituting the basic metal compound and a sheet containing a physical development nucleus are superimposed on a film surface, and heated in the presence of water and a silver halide solvent to form a silver image. Wherein at least one layer constituting the silver halide light-sensitive material contains the water-insoluble basic metal compound and the compound represented by the general formula (1). Method. Formula (1) (R ₁ ) n-Ar-SH (wherein R ₁ represents an aliphatic group, an aromatic group, a heterocyclic group, a carboxy group, an acyl group, and a sulfonyl group, and the total number of carbon atoms is 8) Ar represents a carbon aromatic ring or a heteroaromatic ring, and n represents an integer of 0 to 2.) 2. The image forming method according to claim 1, wherein the compound represented by the general formula (1) is a compound represented by the following general formula (2). Embedded image (In the formula, Q represents an atom group necessary for forming a 5- or 6-membered heterocyclic ring composed of at least one atom of a carbon atom, a nitrogen atom, an oxygen atom and a selenium atom. L represents a heterocyclic ring or a divalent linking group substituted with a carbon or heteroaromatic ring fused to the heterocyclic ring;
Represents a ballast group having 8 or more carbon atoms. n represents an integer of 0 or 1. )