JPH1115120A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the image forming method capable of forming a black-and- white image high in density in a short time and superior in discrimination. SOLUTION: The silver halide photosensitive material contains photosensitive silver halide, a basic metal compound hardly soluble in water, a hydrophilic binder, a reducing agent, and a compound represented by the formula on a support, and after the time or at the same time of imagewise exposure, it is overlaid on a sheet containing a compound capable of forming a complex with the metal ions for forming the above basic metal, physical development nuclei, and a silver halide solvent, face to face, and they are heated in the presence of water containing sulfite ions to form an image. In the formula, L is an H atom or a lower alkyl group; each of R1 and R2 , is a univalent organic group; each of R3 and R4 is an H atom or an alkyl car aralkyl or aryl or heterocyclic group.

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, and provides a black-and-white image excellent in sharpness, free of unevenness in a short time, and excellent in discrimination, especially Dmin. And an image forming method.

[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.

[0003] Heat-developable black-and-white photosensitive materials in such a field include, for example, "Dry Silver" as a product of 3M Company,
"Dry view" is widely known as a photothermographic material. The light-sensitive material mainly comprises silver halide, an organic silver salt, and a reducing agent. In this system, since undeveloped silver halide and organic silver salt remain in the light-sensitive material after image formation, the silver halide and organic silver salt react when exposed to strong light or when stored for a long period of time. 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 Application Laid-Open No.
JP-A-220686 describes an image forming method using a sheet containing a compound containing a sulfite ion. However, the sulfite ion inhibits a hardening reaction of a film constituting the sheet, or the sulfite ion may be stored during storage. It has a drawback that it is oxidized to sulfate ions to increase the residual color of the dye.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for forming a black-and-white image without unevenness, high density and low Dmin in a short time. To provide an image forming method excellent in discrimination.

[0007]

The above objects of the present invention have been attained by the following constitutions.

(1) Photosensitive silver halide on a support,
After or simultaneously with imagewise exposure, a silver halide photosensitive material containing a basic metal compound which is hardly soluble in water, a hydrophilic binder, a reducing agent and a compound represented by the following general formula (1) A compound capable of forming a complex with a metal ion constituting a reactive metal compound, a physical development nucleus, and a sheet containing a silver halide solvent are superimposed on the film surface, and heated in the presence of water containing sulfite ions. An image forming method comprising forming a silver image by heating.

[0009]

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[Wherein L represents a hydrogen atom or a lower alkyl group, R ₁ and R ₂ each represent a monovalent organic group,
R ₃ and R ₄ each represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group or a heterocyclic group. (2) The image forming method as described in (1) above, wherein the photosensitive silver halide is silver chloride of 70 mol% or more.

The present invention will be described in more detail. First, the compound of the general formula (1) will be described.

In the general formula (1), examples of the alkyl group represented by R ₃ and R ₄ include methyl, ethyl, propyl,
Linear chains such as isopropyl, n-butyl, cyclohexyl,
Examples of branched and cyclic groups include aralkyl groups such as benzyl and phenethyl, and aryl groups such as benzothiazolyl, pyridyl and pyrimidyl.
Sulfolanyl and the like are mentioned, and an alkyl group, an aralkyl group and an aryl group are preferred.

The alkyl group, aralkyl group, aryl group and heterocyclic group represented by R ₃ and R ₄ can have various substituents, for example, sulfo, carboxy, hydroxy, cyano, halogen (eg, fluorine, chlorine) ), Alkyl (eg, methyl, isopropyl, trifluoromethyl,
t-butyl, ethoxycarbonylmethyl, sulfomethyl, etc.), amino (eg, amino, dimethylamino, sulfoethylamino, piperidino, morpholino, etc.), alkoxy (eg, methoxy, ethoxy, sulfopropoxy, etc.), sulfonyl (eg, methanesulfonyl, ethanesulfonyl) ), Sulfamoyl (eg, sulfamoyl, dimethylsulfamoyl, etc.), acylamino (eg, acetamido, benzamide, sulfobenzamide, etc.), carbamoyl (eg, carbamoyl, phenylcarbamoyl, sulfocarbamoyl, etc.), sulfonamide (eg, methanesulfonamide, benzenesulfone) Amide), alkoxycarbonyl, hydroxycarbonyl, benzyloxycarbonyl, etc.), aryloxycarbonyl For example phenoxycarbonyl, etc. nitrophenoxy carbonyl), it may be mentioned the groups.

The aralkyl group and the aryl group represented by R ₃ and R ₄ preferably have at least one of a sulfo group, a carboxy group and a phosphate group on the aromatic nucleus, and more preferably at least one group. It is desirable to have a sulfo group.

In the general formula (1), R ₁ and R ₂ are preferably alkyl, aryl, aralkyl, heterocyclic, carboxy, alkoxycarbonyl, aryloxycarbonyl, carbamoyl, ureido, thioureido. Group, acylamino group, acyl group, imide group,
Represents a cyano group, a hydroxy group, an alkoxy group, or an amino group.

Specific examples of the alkyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, acylamino group, alkoxy group and amino group represented by R ₁ and R ₂ are represented by R ₃ and R ₄ described above. And the same as the specific examples of the substituent introduced into the alkyl group, the aralkyl group, the aryl group, and the heterocyclic group.

The aryl groups represented by R ₁ and R ₂ include, for example, phenyl, sulfopropoxyphenyl, cyanophenyl, carboxyphenyl, nitrophenyl, and sulfophenyl. The aralkyl groups include, for example, benzyl, phenethyl, and sulfobenzyl. As the heterocyclic group, for example, furyl, thienyl and the like, and as the ureido group, for example, methylureide, phenylureide and the like,
Examples of the thioureido group include acetyl, pivalyl and the like.

Further, as the groups represented by R ₁ and R ₂ , a substituent having a Hammett σp value of 0.3 or more is more preferable from the viewpoint of reducing residual color contamination, and most preferably —CN, —CF
_{(R 5) (R 6)} , - COOR 7 or -CON (R ₈₎ (R
₉ ). Here, R ₅ and R ₆ are a hydrogen atom, a fluorine atom,
Represents a fluoroalkyl group having 1 to 4 carbon atoms, R ₇ represents an alkyl group, an aryl group or a heterocyclic group, and R ₈ and R ₉ represent a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. The groups represented by R ₅ , R ₆ , R ₇ , R ₈ and R ₉ each may further have a substituent.

As the water-soluble dye represented by the general formula (1), a water-soluble dye is dissolved in the following solution, and the half-life of the absorbance at a maximum absorption wavelength at 35 ° C. is measured by a spectrophotometer. The half-life of the absorbance is preferably 1 hour or less from the viewpoint of residual color, and more preferably 10 minutes or less.

Solution Composition Pure water 800 ml Potassium sulfite 0.3 g Potassium carbonate 27 g Water is added to make a total volume of 1 liter.

Typical examples of the compound represented by the above general formula (1) are shown below, but the present invention is not limited thereto.

[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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In addition to the above, JP-A-7-7775,
Dye compounds having a small substituent molecular weight described in JP-A-152127 and JP-A-7-217170 can also be mentioned.

The compound represented by the general formula (1) is disclosed in
No. 6,850, 2-143245, etc.

In order for the dye represented by the general formula (1) of the present invention to be contained in the silver halide light-sensitive material emulsion layer or another hydrophilic colloid layer, the dye or an organic or inorganic dye is generally used. The alkali salt may be dissolved in an aqueous solution or an organic solvent (eg, alcohols, glycols, cellosolves, dimethylformaldehyde, dibutyl phthalate, tricresyl phosphate, etc.), emulsified and dispersed if necessary, and added to the coating solution. good. Further, the dye can be added in a finely dispersed state in a solid state.

The water containing a sulfite ion used in the present invention is obtained by dissolving a water-soluble compound containing a sulfite ion in water. As the compound containing a water-soluble sulfite ion, for example, sodium sulfite, sodium bisulfite, potassium sulfite, ammonium sulfite, ammonium bisulfite and the like are preferably used. As counter ions for sulfite ions,
Alkali metals such as sodium, potassium and lithium are preferred in terms of water solubility, but ions of alkaline earths, other metals, and organic compounds such as ammonium, guanidium, amidines and tetraalkylammonium hydroxide are also preferably used.

The content of sulfite ions in the water containing sulfite ions is from 0.1 mmol to 2.5 mol / l, preferably from 1 mmol to 1 mol / l. More preferably, it is 0.5 mol / liter.

The water containing sulfite ions used in the present invention may be supplied to a light-sensitive material or a complexing agent sheet immediately before heat development, and then both may be bonded to each other for heat development.
In this case, the water containing the sulfite ion may be an aqueous alkaline solution, or a water containing a surfactant or the solvent. The feed rates of water containing sulfite ions are:
It is preferably within the range of the maximum swelling film thickness of the photosensitive material or the complexing agent sheet 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.

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.

Examples of the reducing agent that can be used in the present invention include, for example, US Pat.
Nos. 761, 270, 3,764, 328, 3, 3
42,599, 3,719,492, Research Disclosure No. 12146, 15
Nos. 108 and 15127, and JP-A-56-2713.
2, p-phenylenediamine, p-aminophenol-based developing agents, phosphoric amide phenol-based developing agents, sulfonamidoaniline-based developing agents, and hydrazone-based compounds described in JP-A Nos. 53-135628 and 57-79035. Developing agents, phenols, sulfonamidophenols, polyhydroxybenzenes, naphthols, hydroxybisnaphthyls, methylenebisphenols, ascorbic acids, 1-aryl-3-pyrazolidones,
There are hydrazones and precursors of the various reducing agents described above.

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

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 content of Cl-is 70%.
More preferably, it is 80% or more. Especially Cl
^- content is preferably 90% or more or silver chloride.

These silver halides 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. 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 clear crystal habit or those having no distinctive crystal habit can be used. Also,
For example, JP-A-58-111933 and 58-119
No. 34, Research Disclosure No. 34; 2253
No. 4, as described in No. 4, having two parallel crystal planes, and each of these crystal planes is a particle having a larger area than the other crystal planes, and the ratio of the diameter to the thickness of the particle is large. About 5:
One or more tabular silver halides can also be used.

Further, for example, US Pat. No. 2,592,250
Nos. 3,220,613 and 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 may be formed at any stage of the grain formation by using iridium, gold, rhodium, iron,
Metal ion species such as 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 photosensitive silver halide emulsion has a particle size of about 0.05 to 2 μm, preferably about 0.1 to 1.0 μm.
μm. 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.

The photosensitive silver halide emulsion is prepared 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 can be appropriately subjected to spectral sensitization to blue, green, red and infrared light by a known spectral sensitizing dye. Representative sensitizing dyes are described in, for example,
JP-A-9-180553, JP-A-60-140335, JP-A-60-263937, JP-A-61-65232.
JP-A-61-153635, JP-A-61-153
No. 631, No. 62-32446, No. 63-6
Nos. 1242, 63-138343, JP-A-3-163440, 4-31854, 4-34547, 5-45833, and the like. Further, for example, JP-A-62-39846, JP-A-62-86360, and JP-A-62-89037
JP-A-62-147450, JP-A-62-147450
As described in JP-A-451-451, two or more sensitizing dyes may be used in combination with a single silver halide.

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

These light-sensitive silver halide and light-sensitive silver salt-forming components are used in an amount of about 0.01 to 40 g per 1 m ² of the light-sensitive material.
Preferably, it is used 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 include 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 used in the present invention includes zinc or aluminum oxides, hydroxides and basic carbonates, particularly preferably zinc oxide, zinc hydroxide and basic carbonate. Zinc. 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 from 0.01 to 2 μm, preferably from 0.05 to 1 μm. The content in the light-sensitive material is 0.1 to 5 g / m ² , preferably 0.0 to 5 g / m ² .
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 separate 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. In particular, 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,
There are synthetic or natural polymer substances such as starch, agar, and gum arabic, and these can be used alone or in combination of two or more.

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. 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 usually 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.

According to the image forming method of the present invention, a silver image can be formed 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 0.01 mol to 10 mol, preferably 1 mol, per mol of silver halide.
0.1 to 5 mol.

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, or sulfides, selenides and tellurides of these metals can be used. Of these, zinc, silver, and sulfides 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 the metal ion solution with a soluble sulfide, selenide or telluride solution to form a water-insoluble metal sulfide. , A metal colloidal dispersion of metal selenide or metal telluride. These physical development nuclei are contained in the complexing agent sheet, 10 ^-6 to 1
g / m ^2, preferably included 10 ^-5 ~0.1g / m ^2.

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 release a basic compound by decarboxylation upon heating (such as guanidine trichloroacetic acid), and compounds that decompose to release amines by an intramolecular nucleophilic substitution reaction, etc. 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] A heat solvent used in the photothermographic material and the complexing agent sheet to promote the transfer of image dyes and for other purposes has a function of liquefying during thermal development to promote thermal development and the 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)
7643), JP-A-51-19525 and 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.

[Fogging inhibitor] For example, see 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, 59-572
No. 34, di- or tri-halides;
Thiol compounds described in JP-A-11-11636;
No. 554, antifoggants having a hydrophilic group;
Polymer antifoggants described in No. 2-121452, 6
An antifoggant having a ballast group described in JP-A-2-123456 is exemplified.

Further, water-soluble halides (potassium bromide, potassium iodide, sodium chloride, etc.) and the like 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 N
o. No. 17029, the same No. No. 29963, JP-A-62
No. 135825 and 64-13546. The complexing agent sheet of the present invention preferably does not contain a mordant.

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 preferred. In this case, at least one side (particularly preferably the complexing agent-containing layer side) 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).
No. 182785, No. 61-159644,
Development accelerators, antifoggants (KBr, NaCl, KI,
Nitrogen-containing heterocyclic compounds such as benzotriazole derivatives and 1-phenyl-5-mercaptotriazole derivatives, etc.), pH regulators (acid and acid precursors, base precursors, etc.), thermal solvents, organic fluorine compounds, oil droplets, interfaces Activator, hardener, polymer latex (for example,
15645), 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. For the back layer, either a hydrophilic binder or a hydrophobic binder can be used, but 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.

The 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 (eg, 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 70 to 100 ° C., preferably 1 to 100 seconds, more preferably 2 to 100 seconds after or simultaneously with imagewise exposure. After heat development for 60 seconds, a silver image is formed on the photosensitive material or the complexing agent sheet.

In the photothermographic material of the present invention, a known heating means can be applied at the time of heat 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 a 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 the reverse 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, as described in JP-A-63-250646, in the dye release system, silver development is performed at a low temperature in advance so that silver development occurs preferentially prior to the dye release reaction, and silver development is performed to some extent. And heat development.

[0080]

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. 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 the sensitizing dye was added, the mixture was further aged at 60 ° C. for 10 minutes, and then 0.9 g of ST-1 was added per mol of silver halide as a stabilizer to terminate the chemical sensitization to obtain a silver halide emulsion. .

[0083]

Embedded image

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 a further 0.8 diameter
Approximately 180 g of glass beads with a sand grinder (B
SG-1 / 16 by Imex Co., Ltd.) 1 hour 22
Dispersed at 00 revolutions. After dispersion, the glass beads were filtered off and 2
The glass beads were washed with 5 ml of water, and the wash 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 structure was coated on a polyethylene terephthalate having a thickness of 180 μm and subbed with gelatin. 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 Stabilizer 1.25 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 disodium 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) 0.03 g Development inhibitor 0.06 g Development inhibitor-2 0.04 g Compound A-34 0.07 g Fourth layer (protective layer) Alkali-treated gelatin 0.24 g Phenylcarbamoylated gelatin 0.09 g Polyvinylpyrrolidone (PVP) 0.05) 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) 01g Compound A-34 in the third layer in the same manner as for photosensitive material 101
In the same manner as in the light-sensitive material 1 except that dye-1 was added instead of
02 was created. The light-sensitive material was stored at 40 ° C. and a relative humidity of 60% for 2 days to harden to a desired hardness. The structure of the compound used is shown below.

[0087]

Embedded image

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 coated on the surface of the toner (containing titanium dioxide by weight of 2% by weight) to prepare a complexing agent sheet 201. (The amount of addition is represented by the amount per 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) 4 g polyvinyl alcohol (PVP) 0.4 g sodium benzyliminodiacetate 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 the desired degree of hardening. Was. In addition, the film surface pH of these complexing agent sheets was 9.8.

Preparation of Immersion Water In pure water, sodium sulfite, sodium thiosulfate, thiourea, sodium thiocyanate, and ascorbic acid were each dissolved so as to be 5 mmol per liter.

Evaluation of Photothermographic Material The obtained photothermographic material was subjected to wedge exposure using a 786 nm semiconductor laser, and purified water and the above-prepared 2
After immersion in each immersion water at 5 ° C. for about 2 seconds, the complexing agent-containing layer surface of the complexing agent sheet and the photosensitive layer surface were overlapped,
Heated for 5 seconds. Then, when the complexing agent sheet was peeled off, a silver image was obtained on the photosensitive material and the complexing agent sheet. The red light transmission density of Dmax and Dmin of the obtained light-sensitive material is determined by PD
A-65: Measured using Konica Corporation, and the results are shown in Table 1.
Summarized in

[0091]

[Table 1]

As is clear from the table, it can be seen that an image having a low Dmin can be obtained by treating with the compound represented by the general formula (1) and water containing sulfite ions.

Example 2 A complexing agent sheet 202 was prepared in the same manner as in Example 1, except that 0.1 g of sodium sulfite was added per 1 m ² to the second layer of the complexing agent sheet 201 prepared in Example 1. I let it.
To evaluate the storage stability of the complexing agent sheet, 201 and 2
02 was stored at 50 ° C. and 80% humidity for 3 days.

Evaluation of Photothermographic Material The photothermographic material 101 of Example 1 was subjected to wedge exposure using a 786 nm semiconductor laser, immersed in pure water for about 2 seconds, and stored with the complexing agent sheet 202 and the stored complex. After the surface of the complexing agent-containing layer of the agent sheet 202 and the surface of the photosensitive layer were overlapped, the mixture was heated at 80 ° C. for 25 seconds. Then, when the complexing agent sheet was peeled off, a silver image was obtained on the photosensitive material and the complexing agent sheet. The red transmission density of Dmax and Dmin of the obtained light-sensitive material was measured using PDA-65: manufactured by Konica Corporation.

The complexing agent sheet 201 and the stored complexing agent sheet 201 are the same except that the photosensitive material 101 is immersed in water in which sodium sulfite is dissolved in pure water at a concentration of 5 mmol per liter. Processed. The results are summarized in Table 2.

[0096]

[Table 2]

As is clear from the table, when sulfite ions are contained in the complexing agent sheet, unevenness is generated, and when the complexing agent sheet is stored, the decolorizing effect of the dye is lost, whereas the sulfite ions are dissolved in water. It can be seen that a low Dmin image without unevenness can be obtained by using the immersion water.

[0098]

According to the present invention, in the method for forming a black-and-white image, an image forming method excellent in discrimination with high density and low Dmin in a short time without unevenness can be provided.

Claims (2)

[Claims] 1. A silver halide light-sensitive material containing a photosensitive silver halide, a water-insoluble basic metal compound, a hydrophilic binder, a reducing agent and a compound represented by the following general formula (1) on a support. After or at the same time as the imagewise exposure of the material, a film containing a compound capable of forming a complex with a metal ion constituting the basic metal compound, a physical development nucleus, and a sheet containing a silver halide solvent is superposed. In addition, an image forming method comprising heating in the presence of water containing sulfite ions to form a silver image. Embedded image Wherein L represents a hydrogen atom or a lower alkyl group;
R ₁ and R ₂ each represent a monovalent organic group, and R ₃ and R ₄ each represent a hydrogen atom, an alkyl group, an aralkyl group, an aryl group or a heterocyclic group. ] 2. The image forming method according to claim 1, wherein said photosensitive silver halide is 70 mol% or more of silver chloride.