JP2001166428A - Organic silver salt-containing image recording/forming material, image recording method, image forming method and method for storing same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material less liable to fog in long-term storage and excellent in the stability of a silver image after heat development and an image recording method. SOLUTION: The organic silver salt-containing image recording/forming material is stored in an atmosphere having >=85% volume fraction of an inert gas. The heat development photosensitive material contains at least a) an organic silver salt, b) photosensitive silver halide, c) a reducing agent capable of reducing the silver ion of the organic silver salt to silver when activated by heat and d) a binder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material excellent in storability, and particularly to a black-and-white photothermographic material excellent in storability of a silver image after development.

[0002]

2. Description of the Related Art Conventionally, in the fields of medical treatment and printing plate making, waste liquid caused by wet treatment of an image forming material has been a problem in terms of workability. It is strongly desired to reduce the amount of waste liquid.

[0003] Therefore, there is a need for a technique relating to photothermographic materials for photographic technology, which enables efficient exposure with a laser imager or a laser imagesetter and can form a high-resolution, clear black image. .

Such techniques include, for example, US Pat. Nos. 3,152,904 and 3,487,075; Morgan (Dry Silver Photograph)
hic Materials) ”(Handbook)
of Imaging Materials, Marc
el Dekker, Inc. 48, 1991), a photothermographic material containing an organic silver salt, photosensitive silver halide particles, and a reducing agent on a support is known. Since this photothermographic material does not use any solution processing chemicals, it is possible to provide the user with a system that is simpler and does not damage the environment.

[0005] By the way, heat-developable photosensitive materials (hereinafter also referred to as photosensitive materials) contain an organic silver salt, photosensitive silver halide particles, and a reducing agent. Not only is it easy to occur, but also there is a problem that fogging or photolytic silver (printout silver) is likely to occur during the storage period after the heat development. In particular, in the photosensitive material, after exposure, usually, only heat development is performed at 80 to 250 ° C., and fixing is not performed.
During long-term storage under conditions where an organic silver salt and a reducing agent coexist, there has been a problem that a silver image is discolored by heat or light.

That is, the reaction with the organic silver salt tends to generate thermal fog due to the presence of the reducing agent in the photosensitive material, and the wavelength range different from the light for image recording after development. In addition to the original function that the reducing agent reduces silver ions even when irradiated with light, the printed out silver from silver halide or organic silver salt is inevitably large because it functions as a hole trap in addition to the original function of reducing silver ions. Is considered as one of the causes.

In addition to the above-mentioned causes, it is conceivable that fog nuclei which cause fogging are formed in the manufacturing process of the photosensitive material.

Techniques for solving these problems are disclosed in JP-A-6-208192, JP-A-8-267934, US Pat. No. 5,714,311 and the references cited in these patent documents. Although these disclosed technologies have some effects, they are not yet enough technologies to satisfy the level required in the market.

On the other hand, with respect to the preservation method of the photosensitive material before use, the packaging of the silver halide photographic material is usually made by folding one sheet of a sheet-like film such as an X-ray film or a printing film. Or a packaging unit in which a predetermined number of the gripped sheets are gripped by a U-shaped thick letter, or excluding the folded interleaf paper, The unit is clamped with a thick letter to protect it from external impact, and is suctioned and degassed into a barrier bag to keep it light tight. On the other hand, roll-type silver halide photographic light-sensitive materials such as films for indirect photography use a packaging form that is held light-tight in a metal or plastic container.

However, if the suction and deaeration are strengthened and the degree of vacuum is increased during the suction and deaeration packaging, the peeling failure occurs due to the close contact with the barrier bag or the mutual adhesion of the films, so that the deaeration rate is 8%.
Light-tight packaging is performed at about 0%. Therefore, the influence of oxygen and the like remaining in the barrier bag cannot be avoided, resulting in an increase in fog, a change in sensitivity, a decrease in the maximum density, and the like.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide:
An object of the present invention is to provide a photothermographic material and an image recording method which are less fogged when the photothermographic material is stored for a long period of time and are excellent in stability of a silver image after heat development.

[0012]

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

(1) A storage method comprising storing an image recording / forming material containing an organic silver salt in an inert gas atmosphere having a volume fraction of 85% or more.

(2) A storage method comprising storing an image recording / forming material containing an organic silver salt in a gas atmosphere in which the volume fraction of oxygen is 15% or less.

(3) The image recording method according to the above (1), wherein the inert gas is at least one gas selected from nitrogen, helium and argon.
How to store the formed photosensitive material.

(4) The image recording / forming material containing an organic silver salt is a photothermographic material.
The storage method according to any one of claims 1 to 3.

(5) The photothermographic material as described in (4) above,
At least a) an organic silver salt, b) a photosensitive silver halide,
c) a photothermographic material comprising: a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat; and d) a binder.

(6) At least a) an organic silver salt, b)
Heat development comprising photosensitive silver halide, c) a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat, d) a binder, and e) a crosslinking agent for the binder. A halogen which is a photosensitive material, and which can inactivate the reducing agent by exposing the photothermographic material to ultraviolet light or visible light after thermal development, so that the organic silver salt cannot be reduced to silver. 6. The photothermographic material according to the above item 5, comprising a compound that generates a reactive species other than an atom.

(7) The photothermographic material as described in (5) or (6) above, wherein the photosensitive silver halide has been subjected to supersensitization with a mercapto compound.

(8) A compound that generates a reactive species other than a halogen atom, which can inactivate a reducing agent by exposing it to ultraviolet light or visible light so that an organic silver salt cannot be reduced to silver. 8. The photothermographic material according to item 6 or 7, further comprising a compound that generates a halogen atom as a reactive species.

(9) The photothermographic material as described in any one of (6) to (8) above, wherein the reactive species other than the halogen atom is a free radical comprising a plurality of atoms.

(10) The photothermographic method as described in any one of (6) to (9) above, wherein the compound generating a reactive species other than a halogen atom has a carbocyclic or heterocyclic aromatic group. material.

(11) The photothermographic material as described in any one of (5) to (10) above, wherein the photosensitive silver halide is sensitized with an infrared spectral sensitizing dye.

(12) The photothermographic material as described in any one of (6) to (11) above, wherein the crosslinking agent for the binder is selected from an epoxy compound, an acid anhydride, an isocyanate compound, and a thioisocyanate compound. .

(13) A laser exposure machine wherein the angle between the exposed surface of the photothermographic material and the scanning laser beam does not become substantially perpendicular to the photothermographic material according to any one of the above (5) to (12). An image recording method, comprising:

(14) An image is recorded on the photothermographic material according to any one of the above items (5) to (12), wherein a scanning laser beam is exposed by a laser beam scanning exposure device having a vertical multi-scanning laser beam. Image recording method.

[0027] (15) an image forming method photothermographic material according to any one of the 5 to 12 is characterized in that heat development in the state containing 5~1000mg per photosensitive material 1 m ² of the organic solvent .

(16) A storage method, wherein the photothermographic material according to any one of (5) to (12) is stored in an inert gas atmosphere having a volume fraction of 85% or more.

(17) A storage method, wherein the photothermographic material according to any one of the above items (5) to (12) is stored in a gas atmosphere having a volume fraction of oxygen of 15% or less.

Hereinafter, the present invention will be described in more detail. As described above, the present inventor has proposed an image recording and recording method that contains an organic silver salt.
In the case of forming materials, especially photothermographic materials, when the light-sensitive material is light-tightly degassed and packaged, the material is packaged under an atmosphere of an inert gas such as nitrogen gas or a rare gas. By enclosing and packaging together with the established oxygen absorber package, it absorbs residual oxygen and keeps the inside of the packaging container anaerobic and light tight, and produces heat without fogging, sensitivity over time, and reduction in maximum concentration. It has been found that a developed photosensitive material can be obtained.

Further, the present inventor has proposed that, when a photothermographic material as described below is thermally developed, when the image is exposed to ultraviolet light and visible light, the reducing agent is inactivated to thereby reduce the organic silver salt. In addition, it has been found that the problem can be solved by including a compound capable of releasing a reactive species capable of preventing silver halide from being reduced to silver.

In the present invention, as an inert gas which can be used for packaging an image recording / forming material containing an organic silver salt, particularly a photothermographic material, a rare gas such as nitrogen gas, helium, neon, argon or the like is used. However, from the viewpoint of economy, nitrogen gas is preferable. The nitrogen gas is preferably a gas obtained by vaporizing commercially available liquid nitrogen, a commercially available nitrogen gas in a cylinder, or the like, but may be a gas obtained by a chemical reaction. In order to remove a trace amount of oxygen contained in the nitrogen gas, it is preferable to use a copper piece, an ammonium carbonate solution, a pyrogallol solution, a vanadium sulfate solution, a first titanium salt, a first chromium salt, or the like.
The specific method is described in Experimental Chemistry Course 5
The description on pages 85 to 286 can be referred to.

A process for producing an organic silver salt contained in the image recording / forming material according to the present invention, the method comprising the steps of:
It is preferable that the steps of dispersing and drying the emulsion comprising other necessary additives are performed in an inert gas atmosphere or an air atmosphere having a reduced oxygen content. In such a case, the inert gas is preferably at least 85% by volume fraction.
Further, it is more preferably at least 95%. In addition,
Preferably, the total pressure of the gas is above atmospheric pressure.

The oxygen volume fraction is preferably 15% or less. Further, the content is more preferably 5% or less.

The effect of the inert gas and the like is remarkably exhibited in the production process of the image recording / forming material, particularly when employed in the drying process of an emulsion containing an organic silver salt.

The image recording / forming material according to the present invention, in particular,
The gas atmosphere in the step of packaging the photothermographic material is preferably the same as described above. Furthermore, after degassing under reduced pressure, it is preferable to store an oxygen-absorbing agent in the package under the above-mentioned gaseous atmosphere and under reduced pressure, as described below.

The oxygen absorber which can be used for holding the photosensitive material according to the present invention is a general oxygen absorber.
Ferrous salt, iron powder, nitrite, bisulfite, dithionite, hydroquinone, catechol, resorcinol, pyrogallol, gallic acid, rongalit, ascorbic acid, ascorbate, isoascorbic acid, isoascorbate, It is sorbose, glycose, lignin, dibutylhydroxytoluene, butylhydroxyanisole, or a mixture of the above-mentioned oxygen absorbent and carbon dioxide absorbent, and is known and described in JP-A-2-61148.

The packaging material constituting the air-permeable pouch that can be used as the oxygen absorber package of the present invention is not particularly limited as long as it exhibits a Gurley-type air permeability of 1000 seconds / 100 ml or less.

For example, papers such as Japanese paper, Western paper and rayon paper, nonwoven fabrics using various fibers such as fibers from pulp, cellulose and synthetic resin, packaging materials obtained by laminating a perforated plastic film, paper and a perforated polyethylene film , A packaging material using a microporous membrane or the like is used. These deoxidized packages are described, for example, in JP-A-2-413, JP-A-2-61148, JP-A-2-12876 and JP-A-2-182.
No. 729 and No. 2-268806. Further, a sheet-shaped deoxidized material as described in JP-A-2-86758 may be used.

In order to analyze the gas components in the gas atmosphere and the gas components in the packaging in the production process of the organic silver salt, the process of handling the emulsion containing the organic silver salt, and the packaging process of the photothermographic material. Although various known analysis techniques can be used, gas chromatography, which is generally used for analysis of inorganic gas, is preferable. For example, in order to analyze oxygen, nitrogen gas and the like by the method, it is preferable to use a molecular sieve as a filler.

As the reducing agent used in the photothermographic material according to the present invention, as will be described later, a reducing agent having a proton such as bisphenols or sulfonamidophenols is used. Compounds that can inactivate the reducing agent by generating an active species that can extract the compound are preferred. Preferably, as the colorless photo-oxidizable substance, a compound capable of generating a free radical as a reactive species upon exposure is preferable. Therefore, any compound may be used as long as it has these functions. However, a halogen radical is not preferable because it leads to the formation of silver halide, and an organic free radical comprising a plurality of atoms is preferable. A compound having any structure may be used as long as it has such a function and does not cause any particular adverse effect on the photothermographic material.

These compounds generating free radicals may be carbocyclic or so as to have such a stability that the generated free radicals can be contacted with the reducing agent for a sufficient time to react with and inactivate them. Those having a heterocyclic aromatic group are preferred.

Representative examples of these compounds include the following biimidazolyl compounds and iodonium compounds.

The biimidazolyl compound has the ability to oxidize a reducing agent remaining after image formation due to heat by two imidazolyl radicals, which are free radicals generated when irradiated with ultraviolet light or visible light. Thereby they are inactivated for further reduction of the silver salt. It is surprising that such biimidazolyl compounds can be activated by light to oxidize a reducing agent that is effective in the thermally activated reduction of a substantially light-insensitive organic silver salt.

These biimidazolyl compounds include those represented by the following general formula [1].

[0046]

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Wherein _each of R ₁ , R ₂ and R ₃ (same or different) is an alkyl group (eg, methyl, ethyl, hexyl), an alkenyl group (eg, vinyl, allyl),
Alkoxy groups (eg, methoxy, ethoxy, octyloxy), aryl groups (eg, phenyl, naphthyl,
Tolyl), hydroxy, halogen, aryloxy (eg, phenoxy), alkylthio (eg, methylthio, butylthio), arylthio (eg, phenylthio), acyl (eg, acetyl, propionyl, butyryl, valeryl), A sulfonyl group (eg, methylsulfonyl, phenylsulfonyl), an acylamino group, a sulfonylamino group, an acyloxy group (eg, acetoxy, benzoxy), a carboxyl group, a cyano group, a sulfo group, and an amino group.
Among these, more preferred substituents are an aryl group, an alkenyl group and a cyano group.

The above biimidazolyl compounds are disclosed in US Pat. No. 3,734,733 and British Patent 1,271,17.
It can be produced by the production method described in No. 7 and a method analogous thereto. Preferred specific examples are shown below.

[0049]

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[0050]

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Also, similarly suitable compounds include iodonium compounds represented by the following general formula [2].

[0052]

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In the formula, Q includes atoms necessary for completing a 5-, 6- or 7-membered ring, and the necessary atoms are selected from a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom. R
Each of ¹ , R ² and R ³ (same or different) is a hydrogen atom, an alkyl group (eg, methyl, ethyl, hexyl), an alkenyl group (eg, vinyl, allyl), an alkoxy group (eg, methoxy, ethoxy, Octyloxy), an aryl group (eg, phenyl, naphthyl, tolyl), a hydroxy group, a halogen atom, an aryloxy group (eg, phenoxy), an alkylthio group (eg,
Methylthio, butylthio), arylthio groups (for example,
Phenylthio), acyl group (eg, acetyl, propionyl, butyryl, valeryl), sulfonyl group (eg, methylsulfonyl, phenylsulfonyl), acylamino group, sulfonylamino group, acyloxy group (eg, acetoxy, benzoxy), carboxyl group, cyano Group, sulfo group and amino group. Among these, more preferred substituents are an aryl group, an alkenyl group and a cyano group.

[0054] R ⁴ is acetate, benzoate, carboxylate group such as trifluoroacetate and O ^-
Is shown. W represents 0 or 1.

[0055] X ^- is an anionic counterion, as suitable ^{_{examples, CH 3 CO 2 -, CH}} 3 SO 3 - and PF ₆ ^- is.

The [0056] When R ₃ is a sulfo group or a carboxyl group, W is 0, and R ⁴ is O ^-.

Any of R ¹ , R ² and R ³ may be bonded to each other to form a ring. Among them, particularly preferred compounds are represented by the following general formula [3].

[0058]

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Here, R ¹ , R ² , R ³ , R ⁴ , X ⁻
And W and the like are the same as those in the general formula [2], and Y represents carbon (-CH =) and represents a benzene ring, or represents a nitrogen atom (-N =) and represents a pyridine ring.

The above iodonium compounds are described in Org. Sy
n. , 1961 and "Advanced by Fieser
Organic Chemistry "(Reinh
old, N .; Y. , 1961) and a method analogous thereto. Specific preferred compounds are shown below.

[0061]

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[0062]

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The amount of the compound represented by the above general formulas [1] and [2] according to the present invention is 0.001 to 0.1.
Mol / m ² , preferably 0.005 to 0.05 mol /
m ² . The compound can be contained in any of the constituent layers in the light-sensitive material of the present invention, but is preferably contained near the reducing agent.

In the present invention, as the compound that inactivates the reducing agent and prevents the reducing agent from reducing the organic silver salt to silver, it is preferable that the reactive species is not a halogen atom. The compound which releases as an active species can also be used in combination with the compound of the present invention which releases an active species which is not a halogen atom. Many compounds that can release a halogen atom as an active species are known, and the combined use reduces the drawbacks.

Specific examples of the compounds which generate these active halogen atoms include compounds of the following general formula [4].

[0066]

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In the general formula [4], Q represents an aryl group or a heterocyclic group. X ₁ , X ₂ and X ₃ represent a hydrogen atom, a halogen atom, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfonyl group or an aryl group, at least one of which is a halogen atom. Y is -C
(= O) -, - SO- or -SO ₂ - represents a.

The aryl group represented by Q may be monocyclic or condensed, and is preferably a monocyclic or bicyclic aryl group having 6 to 30 carbon atoms (eg, phenyl, naphthyl, etc.)
And more preferably a phenyl group and a naphthyl group, and further preferably a phenyl group.

The heterocyclic group represented by Q is a 3- to 10-membered saturated or unsaturated heterocyclic group containing at least one atom of N, O or S, and these may be monocyclic. Alternatively, a condensed ring may be formed with another ring.

The heterocyclic group is preferably a 5- or 6-membered unsaturated heterocyclic group optionally having a condensed ring, more preferably a 5- or 6-membered aromatic group optionally having a condensed ring. Group heterocyclic group. More preferably, it is a 5- or 6-membered aromatic heterocyclic group which may have a condensed ring containing a nitrogen atom, particularly preferably a condensed ring which may have a condensed ring containing 1 to 4 nitrogen atoms. And a 6-membered aromatic heterocyclic group. As the heterocycle in such a heterocyclic group, preferably, imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, indazole,
Purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzothiazole, indolenine, tetrazaindene Yes, more preferably imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benz Thiazole and tetrazaindene, more preferably imidazole and pyridene. Down, pyrimidine, pyrazine,
Pyridazine, triazole, triazine, thiadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, benzimidazole and benzthiazole, particularly preferably pyridine, thiadiazole, quinoline and benzthiazole.

The aryl group and heterocyclic group represented by Q may have a substituent in addition to -YC (X ₁ ) (X ₂ ) (X ₃ ). Group, alkenyl group, aryl group, alkoxy group, aryloxy group, acyloxy group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group,
Acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group,
Sulfamoyl group, carbamoyl group, sulfonyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group,
Sulfo group, carboxyl group, nitro group, heterocyclic group, more preferably alkyl group, aryl group, alkoxy group, aryloxy group, acyl group, acylamino group,
Alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, ureido group, phosphoric amide group, halogen atom, cyano group, nitro group, heterocyclic group,
More preferred are an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an acylamino group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, a halogen atom, a cyano group, a nitro group, and a heterocyclic group, and particularly preferred. An alkyl group, an aryl group, and a halogen atom.

X ₁ , X ₂ and X ₃ are preferably a halogen atom, a haloalkyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group and a heterocyclic group, more preferably A halogen atom, a haloalkyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, and a sulfonyl group, more preferably a halogen atom and a trihalomethyl group, and particularly preferably a halogen atom. Among the halogen atoms, a chlorine atom, a bromine atom and an iodine atom are preferred, a chlorine atom and a bromine atom are more preferred, and a bromine atom is particularly preferred.

Y is -C (= O)-, -SO-, -SO ₂
- represents preferably -SO ₂ - is.

Specific examples of these compounds are shown below.

[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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[0080]

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[0081]

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[0082]

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As described above, these compounds inactivate the reducing agent in the photothermographic layer and greatly improve the storability of the photothermographic material. However, these compounds are used for the photothermographic material deactivated by the above-mentioned free radicals. The reducing agent will be described in detail below.

Examples of suitable reducing agents incorporated in the photothermographic material of the present invention are described in US Pat. No. 3,770,448.
No. 3,773,512, No. 3,593,863
And Research Disclosure (hereinafter sometimes abbreviated as RD) 17029 and 29996, and include the following. Aminohydroxycycloalkenone compounds (eg, 2-hydroxypiperidino-2-cyclohexenone); aminoreductones (eg, piperidinohexose reductone monoacetate); N-hydroxyurea derivatives (eg, Np-methylphenyl-N
Hydrazones of aldehydes or ketones (e.g. anthracene aldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (e.g.
Hydroquinone, t-butylhydroquinone, isopropylhydroquinone and (2,5-dihydroxyphenyl) methylsulfone); sulfhydroxamic acids (eg, benzenesulfhydroxamic acid); sulfonamideanilines (eg, 4- (N-methanesulfone) Amido) aniline); 2-tetrazolylthiohydroquinones (for example, 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone); tetrahydroquinoxalines (for example, 1,2,3,4-tetrahydroquinoxaline) Amidoximes; Azines (eg, a combination of an aliphatic carboxylic acid aryl hydrazide and ascorbic acid); A combination of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine; Hydroxamic acids; Α-cyanophenylacetic acid derivatives; combinations of bis-β-naphthol and 1,3-dihydroxybenzene derivatives; 5-pyrazolones; sulfonamide phenol reducing agents; 2-phenylindane-1, 3-dione and the like; chroman; 1,4-dihydropyridines (eg, 2,6-dimethoxy-3,5-dicarboethoxy-
1,4-dihydropyridine); bisphenols (for example, bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, 2,2-bis (4-hydroxy-
3-methylphenyl) propane, 4,5-ethylidene-
Bis (2-t-butyl-6-methyl) phenol), ultraviolet-sensitive ascorbic acid derivatives and 3-pyrazolidones. Among these, particularly preferred reducing agents are bisphenols. Examples of bisphenols include compounds represented by the following general formula (A).

[0085]

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In the formula, R is a hydrogen atom or a group having 1 to 1 carbon atoms.
10 alkyl groups (eg, isopropyl, butyl,
2,4,4-trimethylpentyl), and R ′ and R ″ represent an alkyl group having 1 to 5 carbon atoms (eg, methyl, ethyl, t-butyl).

Specific examples of the compound represented by formula (A) are shown below. However, the present invention is not limited to the following compounds.

[0088]

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[0089]

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The amount of the reducing agent including the compound represented by formula (A) is preferably 1 × 1 per mol of silver.
It is from 0 ^-2 to 10 mol, especially from 1 x 10 ^{-2 to} 1.5 mol.

The photothermographic material of the present invention contains photosensitive silver halide and organic silver salts. The photosensitive silver halide grains in the present invention will be described.

The photographic emulsion used in the present invention is described in US Pat. Gl
Chimie et Physique by Afkids
e Photographique (Paul Mon
tel, 1967); F. By Duffin
Photographic Emulsion Chem
istry (published by The Focal Press, 19
66); L. M by Zelikman et al
aking andCoating Photogra
phi Emulsion (The Focal P
Ress, published in 1964) and the like. That is, any of an acidic method, a neutral method, an ammonia method and the like may be used, and a method of reacting a soluble silver salt with a soluble halide may be any one of a one-sided mixing method, a double-sided mixing method, a combination thereof and the like. Of these methods, the so-called controlled double jet method for preparing silver halide grains while controlling the formation conditions is preferable. The halogen composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide, and silver iodide.

Grain formation is usually divided into two stages of silver halide seed grain (nucleus) formation and grain growth, and these may be carried out continuously at a time, or nucleus (seed grain) formation and grain growth may be carried out. A method in which separation is performed may be used. The controlled double jet method of forming particles by controlling pAg, pH, and the like, which are the conditions for forming particles, is preferred because the shape and size of the particles can be controlled. For example, when performing a method in which nucleation and grain growth are performed separately, first, a soluble silver salt and a soluble halide are uniformly and rapidly mixed in an aqueous gelatin solution to form nuclei (seed particles) (nucleation step). rear,
Silver halide grains are prepared by a grain growing step of growing grains while supplying a soluble silver salt and a soluble halogen salt under controlled pAg, pH and the like. After grain formation, a desired silver halide emulsion can be obtained by removing unnecessary salts and the like by a desalting step by a known desalting method such as a noodle method, a flocculation method, an ultrafiltration method, and an electrodialysis method. I can do it.

The silver halide of the present invention preferably has a small average grain size in order to suppress white turbidity after image formation and obtain good image quality, and has an average grain size of 0.2 μm or less, more preferably. 0.01 μm to 0.1
7 μm, particularly preferably 0.02 μm to 0.14 μm.
The term "grain size" as used herein refers to the length of a ridge of a silver halide grain when the silver halide grain is a cubic or octahedral so-called normal crystal. In the case where the silver halide grains are tabular grains, the diameter refers to a diameter when converted into a circular image having the same area as the projected area of the main surface.

In the present invention, the silver halide grains are preferably monodispersed. The term “monodisperse” as used herein means that the coefficient of variation of the particle size determined by the following equation is 7
% Or less. The particles are preferably at most 5%, more preferably at most 3%, particularly preferably at most 1%.

Coefficient of variation of grain size% = standard deviation of grain size / mean value of grain size × 100 The shape of silver halide grains is cubic, octahedral, 14
Examples thereof include facet particles, tabular particles, spherical particles, rod-like particles, potato-like particles, etc., and in the present invention, cubic particles, octahedral particles, tetradecahedral particles, and tabular particles are particularly preferable.

When tabular silver halide grains are used, the average aspect ratio is preferably from 2 to 100, more preferably from 3 to 50. These are described in U.S. Pat. Nos. 5,264,337, 5,314,798, and 5,320,958, and can easily obtain target tabular grains. Further, grains having rounded corners of silver halide grains can also be preferably used.

Although the outer surface of the silver halide grains is not particularly limited, it is preferable that the ratio occupied by the Miller index [100] plane is high, and this ratio is 50% or more, and more preferably 70%.
It is preferably at least 80%. The ratio of the Miller index [100] plane is [11] in the adsorption of the sensitizing dye.
T] utilizing the adsorption dependency between the [1] plane and the [100] plane. T
ani, J .; Imaging Sci. , 29,165
(1985).

The silver halide grains used in the present invention are:
It is preferable to use a low molecular weight gelatin having an average molecular weight of 50,000 or less when forming the grains, but it is particularly preferable to use the same when forming nuclei of silver halide grains.

In the present invention, the low molecular weight gelatin has an average molecular weight of 50,000 or less, and preferably has a molecular weight of 2,000 to 4,000.
0000, more preferably 5,000 to 25,000. The average molecular weight of gelatin can be measured by gel filtration chromatography.

The low-molecular-weight gelatin may be enzymatically decomposed by adding a gelatin-degrading enzyme to a commonly used aqueous gelatin solution having an average molecular weight of about 100,000, or may be hydrolyzed by adding an acid or an alkali and heating, or under atmospheric pressure or pressure. , Or by irradiation with ultrasonic waves, or by using these methods in combination.

The concentration of the dispersion medium at the time of nucleation is preferably 5% by mass or less, and it is effective to carry out the concentration at a low concentration of 0.05 to 3.0% by mass.

The silver halide grains used in the present invention are:
It is preferable to use a compound represented by the general formula [5] at the time of forming the particles.

Formula [5] YO (CH ₂ CH ₂ O) _m (C (CH ₃ ) HCH ₂ O) _p (C
H ₂ CH ₂ O) _n Y wherein Y is a hydrogen atom, —SO ₃ M, or —CO—B—C
OOM, M represents a hydrogen atom, an alkali metal atom, an ammonium group or an ammonium group substituted with an alkyl group having 5 or less carbon atoms, and B represents a chain or cyclic group forming an organic dibasic acid. Represent. m and n each represent 0 to 50, and p represents 1 to 100.

The compound represented by the general formula [5] is used for producing a silver halide photographic light-sensitive material, a step of producing an aqueous gelatin solution, a step of adding a water-soluble halide and a water-soluble silver salt to the gelatin solution, It has been preferably used as a defoaming agent against remarkable foaming when the emulsion raw material is stirred or moved, such as a step of coating the emulsion on a support. No. 44-9497. The compound represented by the general formula [5] also functions as an antifoaming agent at the time of nucleation.

The compound represented by the general formula [5] is preferably used in an amount of 1% by mass or less based on silver, more preferably 0.01 to 0.1% by mass.

The compound represented by the general formula [5] may be present at the time of nucleation, and is preferably added to the dispersion medium before nucleation, but may be added during nucleation. And
It may be used by being added to an aqueous silver salt solution or an aqueous halide solution used for nucleation. Preferably, it is used by adding 0.01 to 2.0% by mass to an aqueous halide solution or both aqueous solutions. Also, the compounds of the present invention are preferably present for at least 50% of the time of the nucleation step,
More preferably, it is present for a time spanning at least 70%.
Even when the compound represented by the general formula [5] is added as a powder, it is dissolved in a solvent such as methanol, and typical specific examples of the compound represented by the general formula [5] are shown below, but are not limited thereto. Not something. E-1 HO (CH ₂ CH ₂ O) _m (C (CH ₃ ) HCH ₂ O) _19.8 (CH ₂ CH ₂ O) _n H (m + n = 9.77) E-2 NaO ₂ C (CH ₂ ) OCO (CH ₂ CH ₂ O) _m (C (CH ₃ ) HCH ₂ O) ₁₇ (CH ₂ CH ₂ O) _n CO (CH ₂ ) ₂ CO ₂ Na (m + n = 5.7) E-3 KO ₂ CCH = CHCOO (CH ₂ CH ₂ O) _m (C (CH ₃ ) HCH ₂ O) _34.2 (CH ₂ CH ₂ O) _n COCH = CHCO ₂ K (m + n = 8.5) E-4 NaO ₃ SO (C (CH ₃ ) HCH ₂ O) ₁₇ SO ₃ Na

[0108]

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The temperature at the time of nucleation is about 5 to 60 ° C., preferably 15 to 50 ° C. Even if the temperature is constant, the temperature rise pattern (for example, the temperature at the start of nucleation is 25 ° C. The temperature is gradually increased during formation, and the temperature at the end of nucleation is 40 ° C.
It is preferable to control the temperature within the above-mentioned temperature range even if the pattern is the same as above) or vice versa.

The concentration of the silver salt aqueous solution and the halide aqueous solution used for nucleation is preferably 3.5 N or less, more preferably 0.03 N or less.
It is preferably used in a low concentration range of 1 to 2.5 normal.
The rate of addition of silver ion during nucleation is preferably reaction 1l per 1.5 × 10 ^-3 mol / min to 3.0 × 10 ^-1 mol / min, more preferably 3.0 × 10 ^-3 mol / Min ~ 8.
It is 0 × 10 ^-2 mol / min.

The pH at the time of nucleation can be set in the range of 1.7 to 10, but the pH on the alkali side is preferably pH 2 to 6 in order to broaden the particle size distribution of nuclei to be formed. Also, pBr at the time of nucleation is about 0.05 to 3.0, preferably 1.
0 to 2.5, further 1.5 to 2.0.

The silver halide may be added to the image forming layer by any method, and the silver halide is arranged so as to be close to the reducible silver source. Generally, silver halide is prepared in advance and added to a solution for preparing an organic silver salt. Since the silver halide preparation step and the organic silver salt preparation step can be handled separately, it is difficult to control the production. As described in British Patent No. 1,447,454, a halogen component such as a halide ion is allowed to coexist with an organic silver salt-forming component when preparing an organic silver salt, as described in British Patent No. 1,447,454. Can be produced almost simultaneously with the production of the organic silver salt.

It is also possible to prepare a silver halide by converting an organic silver salt with a halogen-containing compound and converting the organic silver salt. That is, a silver halide-forming component is applied to a solution or dispersion of an organic silver salt prepared in advance or a sheet material containing the organic silver salt to convert a part of the organic silver salt into photosensitive silver halide. Can also. The silver halide thus formed is in effective contact with the organic silver salt and exhibits a preferable action. A silver halide-forming component is a compound capable of forming a photosensitive silver halide by reacting with an organic silver salt, and which compound is applicable and effective is determined by the following simple test. I can do things. That is, an organic silver salt is mixed with a compound to be tested, and if necessary, after heating, it is examined by an X-ray diffraction method whether there is a peak specific to silver halide. Silver halide-forming components confirmed to be effective by such tests include inorganic halogen compounds, onium halides, halogenated hydrocarbons, N-halogen compounds, and other halogen-containing compounds. Are U.S. Pat. Nos. 4,009,039 and 3,45
7,075, 4,003,749, British Patent 1,498,956 and JP-A-53-270.
Nos. 27 and 53-25420, each of which is described in detail below. (1) inorganic halide: For example, M is halide (here represented by MX _n, H, NH _4, and represents a metal atom, n represents 1 when the M is H and NH _4, M is a metal When it is an atom, it represents the same value as its valence.
Lithium, sodium, potassium, cesium, magnesium, calcium, strontium, barium, zinc,
Cadmium, mercury, tin, antimony, chromium, manganese, iron, cobalt, nickel, rhodium, cerium and the like. ). Further, halogen molecules such as bromine water are also effective. (2) Onium halides: quaternary ammonium halides such as trimethylphenylammonium bromide, cetylethyldimethylammonium bromide, trimethylbenzylammonium bromide, quaternary phosphonium halides such as tetraethylphosphonium bromide, and trimethylsulfur There are tertiary sulfonium halides, such as phonium iodide. (3) Halogenated hydrocarbons: for example, iodoform,
Bromoform, carbon tetrachloride, 2-bromo-2-methylpropane and the like. (4) N-halogen compounds: For example, N-chlorosuccinimide, N-bromosuccinimide, N-bromophthalimide, N-bromoacetamide, N-iodosuccinimide, N-bromophthalazinone, N-bromo Oxazolinone, N-chlorophthalazinone, N-bromoacetanilide, N, N-dibromobenzenesulfonamide, N-bromo-N-methylbenzenesulfonamide, 1,3-dibromo-4,4-dimethylhydantoin, N- Bromourazole and the like. (5) Other halogen-containing compounds: for example, triphenylmethyl chloride, triphenylmethyl bromide, 2-bromoacetic acid, 2-bromoethanol, dichlorobenzophenone and the like. Two or more of these silver halide forming components may be used in combination.

As described above, the silver halide can be prepared by converting part or all of the silver in the organic acid silver salt to silver halide by reacting the silver salt of the organic acid with the silver ion. It is preferable to use a silver halide in which the size and shape of the silver halide can be controlled.
However, a silver halide produced by converting a part of the organic silver salt to these separately prepared silver halides may be used in combination.

These silver halides may be used in an amount of 0.001 mol to 0.7 mol, preferably 0.03 mol, per 1 mol of the organic silver salt, together with silver halide prepared separately and silver halide obtained by conversion of an organic silver salt. It is preferable to use from 1 mol to 0.5 mol.

The silver halide used in the present invention preferably contains ions of transition metals belonging to groups 6 to 10 of the periodic table. As the above metal, W,
Fe, Co, Ni, Cu, Ru, Rh, Pd, Re, O
s, Ir, Pt, and Au are preferred. These may be used alone or in combination of two or more of the same or different metal complexes.
These metal ions may be directly introduced into silver halide as a metal salt, but can be introduced into silver halide in the form of a metal complex or complex ion. The preferred content is in the range of 1 × 10 ⁻⁹ mol to 1 × 10 ⁻² mol per mol of silver, and more preferably in the range of 1 × 10 ⁻⁸ to 1 × 10 ⁻⁴ . In the present invention, the transition metal complex is preferably a six-coordinate complex represented by the following general formula.

In the formula [ML ₆ ] ^m , M is a transition metal selected from the elements of Groups 6 to 10 of the periodic table, L is a ligand, and m is 0,-, 2-, 3 or
Represents-or 4-. Specific examples of the ligand represented by L include halides (fluoride, chloride, bromide and iodide), cyanide, cyanate, thiocyanate, selenocyanate, tellurocyanate, azide and aquo. Ligand, nitrosyl, thionitrosyl and the like, preferably aquo, nitrosyl and thionitrosyl. If an aquo ligand is present, it preferably occupies one or two of the ligands. L may be the same or different.

The following are specific examples of the transition metal coordination complex ion. 1: [RhCl _6] ^3- 2: [RuCl _6] ^3- 3: [ReCl _6] ^3- 4: [RuBr _6] ^3- 5: [OsCl _6] ^3- 6: [CrCl _6] ^4- 7: [IrCl _6] ^4- 8: [IrCl _6] ^3- 9: [Ru (NO) Cl _5] ^2- 10: [RuBr ₄ (H ₂ O)] ^2- 11: [Ru (NO) (H ₂ O ) Cl _4] ^- 12: [RhCl ₅ (H ₂ O)] ^2- 13: [Re (NO) Cl _5] ^2- 14: [Re (NO) (CN) _5] ^2- 15: [Re (NO ) Cl (CN) _4] ^2- 16: [Rh (NO) ₂ Cl _4] ^- 17: _{[Rh (NO) (H 2 O} ) Cl 4 ] ^- 18: [Ru (NO) (CN) _5] ^{2 -} 19: [Fe (CN) _6] ^3- 20: [Rh (NS) Cl _5] ^2- 21: [Os (NO) Cl _5] ^2- 22: [Cr (NO) Cl _5] ^2- 23: [Re (NO) Cl _5] ^- 24: [ _{Os (NS) Cl 4 (TeCN} ) ] ^2- 25: [Ru (NS) Cl _5] ^2- 26: _{[Re (NS) Cl 4 (SeCN} ) ] ^2- 27: [Os (NS) Cl (SCN) ₄ ] ^2-28 : [Ir (NO) Cl ₅ ] ^2- cobalt and iron compounds are preferably 6-cyano metal complexes, typical examples of which are shown below.

29: [Fe (CN) ₆ ] ^4-30 : [Fe (CN) ₆ ] ³ -31: [Co (CN) ₆ ] ^3- Compounds that provide ions or complex ions of these metals include: It is preferably added during silver halide grain formation and incorporated into silver halide grains.Preparation of silver halide grains, that is, nucleation, growth, physical ripening, and any addition before or after chemical sensitization Good, but especially nucleation, growth,
It is preferably added at the stage of physical ripening, more preferably at the stage of nucleation and growth, and most preferably at the stage of nucleation. In the addition, it may be added in several divided portions, and may be uniformly contained in the silver halide grains.
3, JP-A-2-306236, JP-A-3-167545
Nos. 4-76534, 6-110146, 5
As described in, for example, JP-A-273683, it can be contained in the particles with a distribution.

These metal compounds can be added by dissolving them in water or a suitable organic solvent (eg, alcohols, ethers, glycols, ketones, esters, amides). A method of adding an aqueous solution of a powder or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together to a water-soluble silver salt solution or a water-soluble halide solution during grain formation, or a method in which a silver salt solution and a halide solution are used. When they are mixed simultaneously, they are added as a third aqueous solution to prepare silver halide grains by a three-liquid simultaneous mixing method, a method in which a required amount of an aqueous solution of a metal compound is charged into a reaction vessel during grain formation, or a method in which halogen is added. There is a method in which another silver halide grain doped with a metal ion or a complex ion in advance at the time of preparing silver halide is added and dissolved. In particular, a method of adding an aqueous solution of a powder of a metal compound or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together is added to a water-soluble halide solution. When adding to the particle surface, a required amount of an aqueous solution of a metal compound can be charged into the reaction vessel immediately after the formation of the particles, during or at the end of physical ripening, or at the time of chemical ripening.

The photosensitive silver halide grains separately prepared can be desalted by a known desalting method such as a noodle method, flocculation method, ultrafiltration method, and electrodialysis method.
The photothermographic material can be used without desalting.

The photosensitive silver halide grains in the present invention can be subjected to chemical sensitization. As the chemical sensitization method, known sensitization methods such as sulfur sensitization, selenium sensitization, tellurium sensitization, noble metal sensitization, and reduction sensitization can be used. These sensitization methods can be used in combination of two or more. For sulfur sensitization, thiosulfates, thiourea derivatives, inorganic sulfur and the like can be used. Compounds preferably used for selenium sensitization and tellurium sensitization are described in JP-A-9-2.
The compounds described in No. 30527 can be mentioned. Compounds preferably used for the noble metal sensitization method include, for example, chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, gold selenide, US Pat. No. 2,448,060, and British Patent 618,061
And the like. Ascorbic acid, 2
Thiourea oxide, stannous chloride, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds, and the like can be used. When the pH of the emulsion is 7 or more or pAg
Can be reduced and sensitized by keeping at 8.3 or less.

The photosensitive silver halide in the present invention is preferably subjected to spectral sensitization by adsorbing a spectral sensitizing dye.
Cyanine dyes, merocyanine dyes as spectral sensitizing dyes,
Complex cyanine dye, complex merocyanine dye, holopolar cyanine dye, styryl dye,
Hemicyanine dyes, oxonol dyes, hemioxonol dyes and the like can be used. For example, JP-A-63-1
No. 59841, No. 60-140335, No. 63-23
Nos. 1437, 63-259,651 and 63-304
No. 242, No. 63-15245, U.S. Pat.
9,414, 4,740,455, 4,7
No. 41,966, No. 4,751,175, No. 4,
Sensitizing dyes described in 835,096 can be used.
Useful sensitizing dyes for use in the present invention are, for example, RD176
43 IV-A (p.23, December 1978), 18
431X (August 1978, p. 437). In particular, it is preferable to use a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of the light source of various laser imagers and scanners. For example, JP-A-9-34078, JP-A-9-54409, and JP-A-9-54409
The compounds described in No. 80679 are preferably used.

Useful cyanine dyes are, for example, cyanine dyes having a basic nucleus such as a thiazoline nucleus, an oxazoline nucleus, a pyrroline nucleus, a pyridine nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus and an imidazole nucleus. Preferred useful merocyanine dyes include, in addition to the above basic nuclei, acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus. Including.

In the present invention, it is particularly preferable to use a sensitizing dye having a spectral sensitivity in the infrared. In the present invention, examples of the infrared spectral sensitizing dye preferably used include, for example, US Pat. Nos. 4,536,473 and 4,51.
And infrared spectral sensitizing dyes disclosed in US Pat. Nos. 5,888 and 4,959,294.

Further, particularly preferred spectral sensitizing dyes include the dyes represented by the following formulas (1) to (4).

[0127]

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[In the general formulas (1) to (4), Y₁,
Y_Two, Y₁₁, Y_{twenty one}, Y_{twenty two}And Y₃₁Is an oxygen atom,
Sulfur atom, selenium atom, -C (R_a) (R_b) -Group, or
-CH = CH-, Z₁Is a 5- or 6-membered condensation
Represents the group of non-metallic atoms necessary to complete the ring. R is
Hydrogen atom, lower alkyl group, cycloalkyl group, arral
Kill group, lower alkoxy group, aryl group, hydroxy
Represents a group or a halogen atom; _aAnd R_bAre the hydrogen sources
, A lower alkyl group or R_aAnd R_bFive members joined together
Non-metallic atoms required to form a 6-membered aliphatic spiro ring
Represents R₁, R₁₁, R_{Two 1}, R_{twenty two}, R₃₁And R₃₂Are each
An aliphatic group, or R₁Is W_ThreeAnd R₁₁Is W₁₄Between
Represents a group of nonmetallic atoms necessary for forming a condensed ring. R_c
And R_dIs a lower alkyl group, a cycloalkyl group,
Represents an aralkyl group, an aryl group, or a heterocyclic group. W₁,
W_Two, W_Three, W_Four, W₁₁, W₁₂, W₁₃, W₁₄, W_{twenty one},
W_{twenty two}, W_{twenty three}, W_{twenty four}, W ₃₁, W₃₂, W₃₃And W₃₄Are
Hydrogen atom, substituent, or W₁Is W_TwoAnd W₁₁Is W₁₂When,
W_{twenty one}Is W_{twenty two}And W_{twenty three}Is W_{twenty four}And W₃₁Is W₃₂And W₃₃Is W
₃₄A non-metallic element required to form a fused ring
Represents a child group. V₁~ V₉, V₁₁~ V₁₃, V _{twenty one}~ V₂₉, V₃₁
~ V₃₃Represents a hydrogen atom, a halogen atom, an amino group,
Alkylthio group, arylthio group, lower alkyl group, lower
Represents an alkoxy group, an aryl group, a heterocyclic group, or V
₁Is V_ThreeAnd V_TwoIs V_FourAnd V_ThreeIs V_FiveAnd V_FourIs V₆And V_Five
Is V₇And V₆Is V₈And V₇Is V₉And V₁₁Is V₁₃And V
_{twenty one}Is V_{twenty three}And V_{twenty two}Is V_{twenty four}And V_{twenty three}Is V_{twenty five}And V_{twenty four}Is V₂₆
And V_{twenty five}Is V₂₇And V₂₆Is V₂₈And V₂₇Is V₂₉And V₃₁
Is V₃₃To form a 5- to 7-membered ring
V represents a group of important nonmetallic atoms.₁~ V₉Any one of and V
₁₁~ V₁₃Is a group other than a hydrogen atom.
X₁, X₁₁, X_{twenty one}And X₃₁Each offset the charge in the molecule
Represent the ions required to perform
Each of l31 is an ion required to cancel the charge in the molecule.
Represents the number of k1, k2, k21 and k22 are each 0
Or represents 1. n21, n22, n31 and n32 are each
Each represents an integer of 0 to 2; n21, n22, and n31;
n32 does not become 0 at the same time. p1 and p11 are
Each is 0 or 1, and q1 and q11 are each 1 and
And the sum of p1 and q1 and p11 and q11 is
Do not exceed 2. A more preferred structure among the general formulas (1) and (2) is
(1-1) It is represented by (2-1).

[0129]

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In the general formulas (1-1) and (2-1),
Y ₁ , Y ₂ and Y ₁₁ each represent an oxygen atom, a sulfur atom, a selenium atom, a —C (R _a ) (R _b ) — group or —CH ＝ CH—
Z ₁ represents a group of non-metallic atoms required to complete a 5- or 6-membered fused ring. R is a hydrogen atom, a lower alkyl group, a cycloalkyl group, an aralkyl group, a lower alkoxy group, an aryl group, hydroxy group, a halogen atom, each R _a and R _b, hydrogen atom, a lower alkyl group, or a R _a Represents a group of nonmetallic atoms necessary for forming a 5- or 6-membered aliphatic spiro ring by bonding between _Rb . R ₁ and R ₁₁ are each an aliphatic group, or R ₁ is W ₃ , and R ₁₁ is W
_{And 14} represents a group of nonmetallic atoms necessary to form a condensed ring. W ₁ , W ₂ , W ₃ , W ₄ , W ₁₁ , W ₁₂ , W ₁₃ and W ₁₄ are each a hydrogen atom, a substituent or W ₁ is W ₂ and W ₁₁ is W
₁₂ and W ₁₃ represent a group of nonmetallic atoms necessary for forming a condensed ring by bonding with W ₁₄ . L _{1 to} L ₉ and L _{11 to} L ₁₅ each represent a methine group. X ₁ and X ₁₁ each represent an ion necessary for canceling an intramolecular charge;
Each represents the number of ions required to offset the charge in the molecule. m1 to m3 each represent 0 or 1. p1 and p
11 is each 0 or 1, q1 and q11 are each
An integer of 1 or 2; p1 and q1 and p11 and q11
Do not exceed two.

The substituents will be described in more detail. General formulas (1), (2), (1-1) and (2-) of the present invention
The substituents of the compounds represented by 1), (3) and (4) are described below.

Examples of the condensed ring completed by the non-metallic atomic group necessary for completing the 5- or 6-membered condensed ring represented by Z ₁ in the above general formula include a condensed cyclohexene ring, a condensed benzene ring, Examples include a condensed thiophene ring, a condensed pyridine ring, a condensed naphthalene ring, and the like.Specifically, a benzoxazole ring, a tetrahydrobenzoxazole ring, a naphthoxazole ring, a benzonaphthoxazole ring, a benzothiazole ring, a tetrahydrobenzothiazole ring, a naphthothiazole ring Ring, benzonaphthothiazole ring, thienothiazole ring, thianaphthenothiazole ring, pyridothiazole ring, benzoselenazole ring, tetrahydrobenzoselenazole ring, naphthoselenazole ring, benzonaphthoselenazole ring, quinoline ring, 3,3
-Dialkylindolenin ring, 3,3-dialkylpyridopyrroline ring and the like. Any of the groups described as substitutable groups represented by W _{1 to} W ₄ described below can be substituted on these rings.

The aliphatic groups represented by R ₁ , R ₁₁ , R ₂₁ , R ₂₂ , R ₃₁ and R ₃₂ include, for example, those having 1 to 10 carbon atoms.
Branched or linear alkyl group (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group, iso-pentyl group, 2-ethyl-hexyl group, octyl group, decyl group, etc.), and the number of carbon atoms 3 to 10 alkenyl groups (for example, 2-propenyl group, 3-butenyl group, 1-methyl-
3-propenyl group, 3-pentenyl group, 1-methyl-3
-Butenyl group, 4-hexenyl group, etc.), having 7 to 7 carbon atoms
And 10 aralkyl groups (eg, benzyl group, phenethyl group, etc.).

The above-mentioned groups further include a lower alkyl group (eg, a methyl group, an ethyl group, a propyl group, etc.), a halogen atom (eg, a fluorine atom, a chlorine atom, a bromine atom, etc.),
Vinyl group, aryl group (for example, phenyl group, p-tolyl group, p-bromophenyl group, etc.), trifluoromethyl group, alkoxy group (for example, methoxy group, ethoxy group,
Methoxyethoxy group etc.), aryloxy group (for example,
Phenoxy group, p-tolyloxy group, etc.), cyano group, sulfonyl group (eg, methanesulfonyl group, trifluoromethanesulfonyl group, p-toluenesulfonyl group, etc.), alkoxycarbonyl group (eg, ethoxycarbonyl group, butoxycarbonyl group, etc.) An amino group (eg, amino group, biscarboxymethylamino group, etc.), an aryl group (eg, phenyl group, carboxyphenyl group, etc.), a heterocyclic group (eg, tetrahydrofurfuryl group,
2-pyrrolidinone-1-yl group, etc.), acyl group (eg, acetyl group, benzoyl group, etc.), ureido group (eg, ureido group, 3-methylureido group, 3-phenylureido group, etc.), thioureido group (eg, Thioureido group, 3-methylthioureido group, etc.), alkylthio group (eg, methylthio, ethylthio group, etc.), arylthio group (eg, phenylthio group, etc.), heterocyclic thio group (eg, 2-thienylthio group, 3-thienylthio, 2-imidazolylthio group, etc.), carbonyloxy group (for example,
Acetyloxy group, propanoyloxy group, benzoyloxy group, etc.), acylamino group (eg, acetylamino, benzoylamino group, etc.), thioamide group (eg,
Thioacetamide group, thiobenzoylamino group and the like, or, for example, sulfo group, carboxy group, phosphono group, sulfate group, hydroxy group, mercapto group, sulfino group, carbamoyl group (for example, carbamoyl group, N-methyl) Carbamoyl group, N, N-tetramethylenecarbamoyl group, etc.), sulfamoyl group (eg, sulfamoyl group, N, N-3-oxapentamethyleneaminosulfonyl group, etc.), sulfonamide group (eg, methanesulfonamide, butanesulfonamide) Group), sulfonylaminocarbonyl group (eg, methanesulfonylaminocarbonyl, ethanesulfonylaminocarbonyl group, etc.), acylaminosulfonyl group (eg, acetamidosulfonyl, methoxyacetamidosulfonyl group, etc.), acyl Amino carbonyl group (e.g.,
It may be substituted with a hydrophilic group such as acetamidocarbonyl, methoxyacetamidocarbonyl group, and sulfinylaminocarbonyl group (for example, methanesulfinylaminocarbonyl group, ethanesulfinylaminocarbonyl group, and the like).

Specific examples of the aliphatic group in which these hydrophilic groups are substituted include carboxymethyl, carboxyethyl, carboxybutyl, carboxypentyl, and carboxypentyl groups.
-Sulfate butyl group, 3-sulfopropyl group, 2-
Hydroxy-3-sulfopropyl, 4-sulfobutyl, 5-sulfopentyl, 3-sulfopentyl, 3
-Sulfinobutyl group, 3-phosphonopropyl group, hydroxyethyl group, N-methanesulfonylcarbamoylmethyl group, 2-carboxy-2-propenyl group, o-sulfobenzyl group, p-sulfophenethyl group, p-carboxybenzyl And each group such as a group.

The lower alkyl group represented by R is a linear or branched group having 5 or less carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group,
Isopropyl group and the like. Examples of the cycloalkyl group include, for example, a cyclopropyl group, a cyclobutyl group, and a cyclopentyl group.
Examples of the aralkyl group include a benzyl group, a phenethyl group, a p-methoxyphenylmethyl group, an o-acetylaminophenylethyl group, and the like. The lower alkoxy group is a group having 4 or less carbon atoms. Is a methoxy group, an ethoxy group, a propoxy group, an iso-propoxy group, and the like.Examples of the aryl group include substituted and unsubstituted aryl groups, for example, phenyl, 2-naphthyl, 1-naphthyl, o -Tolyl group, o-methoxyphenyl group, m-chlorophenyl group, m-bromophenyl group, p-tolyl group, p-ethoxyphenyl group, and the like. These groups include a phenyl group, a halogen atom, and an alkoxy group. Groups such as groups and hydroxy groups can be substituted. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

The lower alkyl group represented by R _a and R _b is the same as the lower alkyl group for R.

The lower alkyl group represented by R _c and R _d is a straight-chain or branched group having 5 or less carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, a butyl group and a pentyl group. And an isopropyl group. Examples of the cycloalkyl group include a cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, and a cyclopentyl group.Examples of the aralkyl group include a benzyl group, a phenethyl group, a p-methoxyphenylmethyl group, and o-acetylamino. Examples include a phenylethyl group and the like, and the aryl group includes substituted and unsubstituted ones, for example, a phenyl group, a 2-naphthyl group, a 1-naphthyl group, an o-tolyl group,
o-methoxyphenyl group, m-chlorophenyl group, m-
Examples of the group include a bromophenyl group, a p-tolyl group, and a p-ethoxyphenyl group. Examples of the heterocyclic group include substituted and unsubstituted heterocyclic groups. For example, a 2-furyl group, 5-methyl-2
-Furyl, 2-thienyl, 2-imidazolyl, 2
-Methyl-1-imidazolyl group, 4-phenyl-2-thiazolyl group, 5-hydroxy-2-benzothiazolyl group, 2-pyridyl group, 1-pyrrolyl group and the like.

These groups can be further substituted by groups such as the phenyl group, halogen atom, alkoxy group and hydroxy group described above.

W _{1 to} W ₄ , W _{11 to} W ₁₄ , W _{21 to} W ₂₄ , W ₃₁
Substituents specifically represented by to _W-34, an alkyl group (e.g., methyl group, ethyl group, butyl group, etc. iso- butyl group) include, those aryl groups (monocyclic as well as polycyclic, e.g. Phenyl group, carboxyphenyl group, p-tolyl group, p-butylphenyl group, naphthyl group, etc.), heterocyclic group (for example, tetrahydrofuryl group, 2-pyrrolidinone-
1-yl group, thienyl group, furyl group, pyridyl group, carbazolyl group, pyrrolyl group, indolyl group, etc.), halogen atom (for example, fluorine atom, chlorine atom, bromine atom, etc.), vinyl group, trifluoromethyl Group, alkoxy group (for example, methoxy group, ethoxy group, methoxyethoxy group, etc.), aryloxy group (for example, phenoxy group, p
-Tolyloxy group, etc.), sulfonyl group (for example, methanesulfonyl group, p-toluenesulfonyl group, etc.), alkoxycarbonyl group (for example, ethoxycarbonyl group, butoxycarbonyl group, etc.), amino group (for example, amino group, biscarboxymethyl group) Amino group, etc., acyl group (eg, acetyl group, benzoyl group, etc.), ureido group (eg, ureido group, 3-methylureido group, 3-phenylureido group, etc.), thioureido group (eg, thioureido group, 3- A methylthioureido group, an alkylthio group (eg, methylthio, ethylthio group, etc.), an arylthio group (eg, phenylthio group, etc.), a hydroxy group,
And a styryl group.

These groups can be substituted by the groups described in the description of the aliphatic group represented by R _{1 and the} like. Specific examples of the substituted alkyl group include, for example, 2-methoxyethyl group, 2-methoxyethyl group and 2-methoxyethyl group.
Hydroxyethyl group, 3-ethoxycarbonylpropyl group, 2-carbamoylethyl group, 2-methanesulfonylethyl group, 3-methanesulfonylaminopropyl group, benzyl group, phenethyl group, carboxymethyl group, carboxyethyl group, allyl group, And specific examples of the substituted aryl group include, for example, a p-carboxyphenyl group, a p-N, N-dimethylaminophenyl group, a p-morpholinophenyl group,
-Methoxyphenyl group, 3,4-dimethoxyphenyl group, 3,4-methylenedioxyphenyl group, 3-chlorophenyl group, p-nitrophenyl group, etc., and specific examples of the substituted heterocyclic group For example, 5
-Chloro-2-pyridyl group, 5-ethoxycarbonyl-
Each group such as a 2-pyridyl group and 5-carbamoyl-2-pyridyl is exemplified.

W₁And W_Two, W_ThreeAnd W_Four, W₁₁And W₁₂, W₁₃When
W₁₄, W_{twenty one}And W_{twenty two}, W_{twenty three}And W_{twenty four}, W ₃₁And W₃₂, R₃₃And R
₃₄Are each a condensed ring which can be formed by connecting to each other
Is, for example, a 5- or 6-membered saturated or unsaturated condensation
And carbocycle. Any position on these fused rings
May have a substituent, and these substituents include
The groups described in the group which can be substituted for the above-mentioned aliphatic group are exemplified.
You.

V _{1 to} V ₉ , V _{11 to} V ₁₃ , V _{21 to} V ₂₉ , V ₃₁
Each in ~V _33, fluorine atom as the halogen atom represented, a chlorine atom, a bromine atom, an iodine atom, a substituted as the amino groups include those unsubstituted, for example, an amino group, dimethylamino group, diphenylamino Amino group, methyl-
Examples of the alkylthio group include a methylthio group, an ethylthio group, and a benzylthio group.Examples of the arylthio group include substituted and unsubstituted ones, such as a phenylthio group and an m-fluorophenylthio group. And the lower alkyl group is a straight-chain or branched group having 5 or less carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and an isopropyl group. No. The lower alkoxy group is a group having 4 or less carbon atoms. Specific examples include a methoxy group, an ethoxy group, a propoxy group, and an iso-propoxy group. Including, for example, phenyl, 2-naphthyl, 1-naphthyl, o-tolyl, o-methoxyphenyl, m-chlorophenyl, m-bromophenyl, p-tolyl, p-ethoxyphenyl, etc. Groups include, substituted and unsubstituted heterocyclic groups,
For example, 2-furyl group, 5-methyl-2-furyl group, 2
-Thienyl group, 2-imidazolyl group, 2-methyl-1-
Imidazolyl group, 4-phenyl-2-thiazolyl group, 5
-Hydroxy-2-benzothiazolyl group, 2-pyridyl group, 1-pyrrolyl group and the like.

These groups can be substituted with groups such as a phenyl group, a halogen atom, an alkoxy group and a hydroxy group.

Further, V₁And V_Three, V_TwoAnd V_Four, V_ThreeAnd W_Five, V_Four
And V₆, V_FiveAnd V₇, V₆And V₈, V₇And V₉, V₁₁And V₁₃, V
_{twenty one}And V_{twenty three}, V_{twenty two}And V_{twenty four}, V_{twenty three}And V_{twenty five}, V_{twenty four}And V₂₆, V_{twenty five}
And V ₂₇, V₂₆And V₂₈, V₂₇And V₂₉And V₃₁And V₃₃Among
As the 5- to 7-membered ring formed by bonding, for example,
Cyclopentene ring, cyclohexene ring, cycloheptene
Ring, decalin ring and the like.
Lower alkyl group, lower alkoxy group or aryl group
Can be exchanged.

The methine groups represented by L _{1 to} L ₉ and L _{11 to} L ₁₅ each independently represent a substituted or unsubstituted methine group. Specific examples of the substituted group include a fluorine atom, a chlorine atom,
A substituted or unsubstituted lower alkyl group (e.g., methyl group, ethyl group, iso-propyl group, benzyl group, etc.),
A lower alkoxy group (eg, methoxy group, ethoxy group, etc.), a substituted or unsubstituted aryloxy group (eg, phenoxy group, naphthoxy group, etc.), a substituted or unsubstituted aryl group (eg, phenyl group, naphthyl group,
p-tolyl group, o-carboxyphenyl group, etc.), -N
(U ₁ ) (U ₂ ), —SR _g or a substituted or unsubstituted heterocyclic group (eg, 2-thienyl group, 2-furyl group, N,
N′-bis (methoxyethyl) barbituric acid group).

[0147] wherein R _g is a lower alkyl group, an aryl group or a heterocyclic group described for R group described above, -SR _g
Specific examples of the group include a methylthio group, an ethylthio group, a benzylthio group, a phenylthio group, a tolylthio group, and the like.

U ₁ and U ₂ each represent a substituted or unsubstituted lower alkyl group or aryl group, and U ₁ and U ₂ are linked to each other to form a 5- or 6-membered nitrogen-containing heterocyclic ring (for example, a pyrazole ring). , A pyrrole ring, a pyrrolidine ring, a morpholine ring, a piperidine ring, a pyridine ring, a pyrimidine ring, an indole ring, etc.). In addition, these methine groups can form a 5- to 7-membered ring by linking to methine groups adjacent to each other or to methine groups separated by one.

The formulas (1), (2), (1-1),
In the compounds represented by (2-1), (3) and (4),
When a group having a cation or anion charge is substituted, a counter ion is formed with an equivalent amount of an anion or cation so that the charge in the molecule is offset. For example, specific examples of the cation necessary for canceling the intramolecular charge represented by X ₁ , X ₁₁ , X ₂₁ , and X ₃₁ include a proton, an organic ammonium ion (for example, triethylammonium, Triethanolammonium, each ion such as pyridinium), inorganic cations (for example, each cation such as lithium, sodium, and potassium). Specific examples of the acid anion include, for example, a halogen ion (for example, a chlorine ion, a bromine ion,
Iodine ion), p-toluenesulfonic acid ion, perchlorate ion, boron tetrafluoride ion, sulfate ion, methyl sulfate ion, ethyl sulfate ion, methanesulfonic acid ion, trifluoromethanesulfonic acid ion, hexafluorophosphate ion And the like.

One of these infrared spectral sensitizing dyes of the present invention is characterized by having a tricyclic fused heterocyclic nucleus in which a nitrogen atom of a benzoazole ring is bonded to a carbon atom at the peri position. One is particularly preferably a long-chain polymethine dye characterized in that a sulfinyl group is substituted on the benzene ring of a benzoazole ring.

The following formulas (1), (2) and (1)
-1), (2-1), (3), and (4), representative compounds of the photosensitive dyes or spectral sensitizing dyes are shown below, but the present invention is not limited to these compounds. Absent

[0152]

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[0153]

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[0154]

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[0155]

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[0156]

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[0157]

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[0158]

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[0159]

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[0160]

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[0161]

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[0162]

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[0163]

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[0164]

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[0165]

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The infrared-sensitive dyes described above are described, for example, by FM Hammer, The Chemistry of
Heterocyclic Compounds No. 18
Volume, The Cyanine Dyes and Re
rated Compounds (A. Weissbe
rger ed. Published by Interscience, Ne
w York 1964).

These sensitizing dyes may be used alone or in combination. The combination of sensitizing dyes is often used particularly for supersensitization. Along with the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization.

In the case of supersensitization, the photosensitivity becomes particularly high. If the reducing agent is not deactivated, the printout silver after development tends to be large, and the present invention is particularly effective. In the case of infrared sensitization, the infrared sensitizing dye further has a redox potential capable of reducing silver halide and organic silver salt to some extent. In the presence of a reducing agent that can reduce the organic silver salt, silver clusters that become fogged silver are easily formed. The generated silver clusters also act as catalyst nuclei and induce fog, so that when stored in a dark place, the storage stability decreases,
Further, when exposed to a light place after development, a phenomenon such as an increase in printout silver occurs. Further, the sensitivity of the infrared sensitive material extends to the heat radiation region outside the visible light range, so that it is effective in increasing printout silver due to the heat radiation even in a dark place. In particular, in the case of an infrared spectrally sensitized photosensitive material whose sensitivity has been enhanced by a supersensitizer, the effect is large.

These sensitizing dyes may be used alone or in combination. The combination of sensitizing dyes is often used particularly for supersensitization. Along with the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization, and substances exhibiting supersensitization are described in RD17643 (issued December 1978) No. 23.
Section J on page 1V, or Japanese Patent Publication No. 9-25500, 4
3-4933, JP-A-59-19032, and JP-A-59-19032.
192,242 and JP-A-5-341432.

In the present invention, a heteroaromatic mercapto compound represented by the general formula [6] is preferable as a supersensitizer.

Formula (6) Ar-SM In the formula, M is a hydrogen atom or an alkali metal atom;
r is an aromatic or fused aromatic ring having one or more nitrogen, sulfur, oxygen, selenium, or tellurium atoms. Preferably, the heteroaromatic ring is benzimidazole, naphthymidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, triazine,
Pyrimidine, pyridazine, pyrazine, pyridine, purine, quinoline, or quinazoline. However, other heteroaromatic rings are also included.

The present invention also includes a disulfide compound which forms the above-mentioned mercapto compound when contained in a dispersion of an organic acid silver salt and / or silver halide grain emulsion. In particular, a disulfide compound represented by the following general formula can be mentioned as a preferred example.

Ar in the formula [7] Ar-SS-Ar has the same meaning as in the above formula [6].

The above-mentioned heteroaromatic ring includes, for example, a halogen atom (for example, Cl, Br, I), a hydroxy group, an amino group, a carboxyl group, and an alkyl group (for example, one or more carbon atoms; Those having 4 carbon atoms) and alkoxy groups (eg one or more carbon atoms,
Preferably, it may have a substituent selected from the group consisting of those having 1 to 4 carbon atoms.

The mercapto-substituted heteroaromatics are listed below. However, the invention is not limited to these. M-1 2-mercaptobenzimidazole M-2 2-mercaptobenzoxazole M-3 2-mercaptobenzothiazole M-4 5-methyl-2-mercaptobenzimidazole M-5 6-ethoxy-2-mercaptobenzothiazole M-6 2,2'-dithiobis (benzothiazole) M-7 3-mercapto-1,2,4-triazole M-8 4,5-diphenyl-2-imidazolethiol M-9 2-mercaptoimidazole M-10 1-ethyl-2-mercaptobenzimidazole M-11 2-mercaptoquinoline M-128-mercaptopurine M-13 2-mercapto-4 (3H) -quinazolinone M-147-trifluoromethyl-4-quinolinethiol M -15 2,3,5,6-tetrachloro-4-pyridine All M-16 4-Amino-6-hydroxy-2-mercaptopyrimidine monohydrate M-17 2-amino-5-mercapto-1,3,4
Thiadiazole M-18 3-Amino-5-mercapto-1,2,4-
Triazole M-19 4-Hydroxy-2-mercaptopyrimidine M-20 2-Mercaptopyrimidine M-21 4,6-Diamino-mercaptopyrimidine M-22 2-Mercapto-4-methylpyrimidine hydrochloride M-23 3-Mercapto- 5-phenyl-1,2,4
-Triazole M-24 2-mercapto-4-phenyloxazole The supersensitizer according to the present invention contains 0.001 to 1.0 per mol of silver in the emulsion layer containing the organic silver salt and the silver halide grains.
It is preferable to use it in the molar range. Particularly preferably, the amount is in the range of 0.01 to 0.5 mol per mol of silver.

The binder suitable for the photothermographic material of the present invention is transparent or translucent, generally colorless, and is a natural polymer synthetic resin, polymer or copolymer, or other film-forming medium, for example: gelatin, gum arabic, poly (Vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid) Copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (ester) Kind, poly ( Urethane), phenoxy resin, poly (vinylidene chloride), poly (epoxides),
Poly (carbonate) s, poly (vinyl acetate),
There are cellulose esters and poly (amides). It may be hydrophilic or non-hydrophilic. Preferred binders for the photothermographic layer are polyvinyl acetals, and particularly preferred binder is polyvinyl butyral.
Further, for non-photosensitive layers such as an overcoat layer and an undercoat layer, particularly a protective layer and a back coat layer, polymers having a higher softening temperature, such as cellulose esters, particularly triacetyl cellulose, and a polymer such as cellulose acetate butyrate. preferable.

[0177] The above-mentioned binders can be used in combination of two or more, if necessary. Such a binder is used in an effective range to function as a binder. Effective ranges can be readily determined by one skilled in the art.
As an index when at least the organic silver salt is retained, the ratio of the binder to the organic silver salt is preferably 15: 1 to 1: 2, particularly preferably 8: 1 to 1: 1. That is, the binder amount of the photosensitive layer is preferably 1.5 to 6 g / m ² .
More preferably, it is 1.7 to 5 g / m ² . 1.5g /
If it is less than m ² , the density of the unexposed portion will increase significantly and may not be usable.

The present invention is particularly effective when it has a crosslinking agent. Although the mechanism is unknown, the combined use of the active species generator and the cross-linking agent according to the present invention has a good effect on stability in a dark place and particularly on formation of printout silver in a bright place.

It is known that the use of a cross-linking agent for the above-mentioned binder improves the film adhesion and reduces development unevenness. The fact that it is effective in suppressing printout after development was an unexpected effect.

Examples of the crosslinking agent used in the present invention include various crosslinking agents conventionally used for photographic materials, such as aldehyde-based, epoxy-based, and ethyleneimine described in JP-A-50-96216. , Vinylsulfone, sulfonic ester, acryloyl, and carbodiimide crosslinking agents can be used. Preferred are the following isocyanate compounds, epoxy compounds, and acid anhydrides.

The following general formula [8] which is one of the preferable ones
The isocyanate-based and thioisocyanate-based cross-linking agents represented by Formula (1) will be described.

General formula [8] X = C = NL- (N = C = X) _v [wherein v is 1 or 2, and L is an alkylene, alkenylene, arylene group or alkylarylene group. X is an oxygen or sulfur atom. In the compound represented by the general formula [8], the aryl ring of the arylene group may have a substituent. Examples of preferred substituents are selected from halogen atoms (eg, bromine or chlorine atoms), hydroxy, amino, carboxyl, alkyl and alkoxy groups.

The above-mentioned isocyanate-based crosslinking agents are isocyanates having at least two isocyanate groups and adducts thereof (adducts). More specifically, aliphatic diisocyanates and fatty acids having a cyclic group Group diisocyanates, benzene diisocyanates, naphthalene diisocyanates, biphenyl isocyanates, diphenylmethane diisocyanates, triphenylmethane diisocyanates, triisocyanates, tetraisocyanates, adducts of these isocyanates and diisocyanates with these isocyanates 3
Adducts with polyhydric polyalcohols.

As specific examples, the isocyanate compounds described on pages 10 to 12 of JP-A-56-5535 can be used.

That is, ethane diisocyanate, butane diisocyanate, hexane diisocyanate, 2,2-
Dimethylpentane diisocyanate, 2,2,4-trimethylpentane diisocyanate, decane diisocyanate, ω, ω′-diisocyanate-1,3-dimethylbenzol, ω, ω′-diisocyanate-1,2-dimethylcyclohexane diisocyanate, ω, ω-diisocyanate-1,4-diethylbenzol, ω, ω ′
-Diisocyanate-1,5-dimethylnaphthalene,
ω, ω'-diisocyanate-n-propylbiphenyl, 1,3-phenylenediisocyanate, 1-methylbenzol-2,4-diisocyanate, 1,3-dimethylbenzol-2,6-diisocyanate, naphthalene-1,4-diisocyanate , 1,1'-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4 '
-Diisocyanate, 3,3'-dimethylbiphenyl-
4,4'-diisocyanate, diphenylmethane-4,
4'-diisocyanate, 2,2'-dimethyldiphenylmethane-4,4'-diisocyanate, 3,3'-dimethoxydiphenylmethane-4,4'-diisocyanate, 4,4'-diethoxydiphenylmethane-4,4 '
-Diisocyanate, 1-methylbenzol-2,4,
6-triisocyanate, 1,3,5-trimethylbenzene-2,4,6-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, triphenylmethane-4,4 ', 4'-triisocyanate , Tolylene diisocyanate, 1,5-naphthylene diisocyanate; dimer or trimer adduct of these isocyanates (for example, 2 mol of adduct of hexamethylene diisocyanate, hexamethylene diisocyanate 3)
Molar adduct, 2,4-tolylene diisocyanate 2
Molar adduct, 2,4-tolylene diisocyanate 3
An adduct of two or more different isocyanates selected from these isocyanates; and a dihydric or trivalent polyalcohol (preferably a polyalcohol having up to 20 carbon atoms). Examples thereof include adducts with ethylene glycol, propylene glycol, pinacol, trimethylolpropane, etc. (for example, adducts of tolylene diisocyanate and trimethylolpropane; adducts of hexamethylene diisocyanate and trimethylolpropane, etc.). Among these, an adduct of an isocyanate and a polyalcohol has a particularly high ability to improve interlayer adhesion, and to prevent delamination, image shift, and generation of bubbles. Such a polyisocyanate may be placed on any part of the photothermographic material. For example, in the support (especially when the support is paper, it can be included in the size composition), the photosensitive layer side of the support such as a photosensitive layer, a surface protective layer, an intermediate layer, an antihalation layer, and an undercoat layer It can be added to any layer, and can be added to one or more of these layers.

As the thioisocyanate-based crosslinking agent used in the present invention, a compound having a thioisocyanate structure corresponding to the above isocyanates is also useful.

The amount of the crosslinking agent used in the present invention ranges from 0.001 to 2 mol, preferably from 0.005 to 0.5 mol, per mol of silver.

The isocyanate compound and the thioisocyanate compound which can be contained in the present invention are:
Although it is preferable that the compound functions as the above-mentioned cross-linking agent, v may be zero (0) in the above-mentioned general formula, that is, a compound having only one such functional group may give good results. Hereinafter, specific examples will be listed, but the present invention is not limited thereto.

[0189]

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[0190]

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[0191]

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Further, preferred crosslinking agents in the present invention are epoxy compounds having at least one epoxy group represented by the following general formula and acid anhydrides.

The epoxy compound used in the present invention may be any one having at least one epoxy group, and there is no limitation on the number of epoxy groups, molecular weight, and the like. The epoxy group is preferably contained in the molecule as a glycidyl group via an ether bond or an imino bond. The epoxy compound may be any of a monomer, an oligomer, a polymer and the like, and the number of epoxy groups present in the molecule is usually 1 to 10
About two, preferably two to four. When the epoxy compound is a polymer, it may be a homopolymer or a copolymer, and a particularly preferable range of the number average molecular weight Mn is about 2000 to 20,000.

The epoxy compound used in the present invention has the following general formula:

The compound represented by [9] is preferable.

[0195]

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General formula

In [9], the substituent of the alkylene group represented by R is preferably a group selected from a halogen atom, a hydroxyl group, a hydroxyalkyl group or an amino group. It is preferable that the linking group represented by R has an amide linking moiety, an ether linking moiety, and a thioether linking moiety. Examples of the divalent linking group represented by _{X -SO 2 -, - SO 2} NH -, - S -, - O-, or -
NR'- is preferred. Here, R 'is a monovalent linking group, and is preferably an electron withdrawing group.

Hereinafter, specific examples of the epoxy compound used in the present invention will be shown, but the present invention is not limited to these.

[0198]

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[0199]

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[0200]

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[0201]

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[0202]

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[0203] These epoxy compounds may be used alone or in combination of two or more. The addition amount is not particularly limited, but is preferably in the range of 1 × 10 ⁻⁶ to 1 × 10 ⁻² mol / m ² , more preferably in the range of 1 × 10 ⁻⁵ to 1 × 10 ⁻³ mol / m ² . It is.

In the present invention, the epoxy compound can be added to any layer on the photosensitive layer side of the support such as a photosensitive layer, a surface protective layer, an intermediate layer, an antihalation layer and an undercoat layer. It can be added to one or more layers. Also, it can be added to any layer on the opposite side of the support from the photosensitive layer. In the case of a photosensitive material having a photosensitive layer on both sides, any layer may be used.

The acid anhydride used in the present invention is a compound having at least one acid anhydride group represented by the following structural formula.

[0206]

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The acid anhydride used in the present invention is not limited as long as it has at least one such acid anhydride group, and the number and molecular weight of the acid anhydride group are not limited. ] Is preferable.

[0208]

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In the formula [B], Z represents an atom group necessary for forming a monocyclic or polycyclic ring system. These ring systems may be unsubstituted or substituted. Examples of the substituent include an alkyl group (for example, methyl, ethyl, hexyl), an alkoxy group (for example, methoxy, ethoxy,
Octyloxy), an aryl group (eg, phenyl, naphthyl, tolyl), a hydroxy group, an aryloxy group (eg, phenoxy), an alkylthio group (eg, methylthio, butylthio), an arylthio group (eg, phenylthio), an acyl group (eg, , Acetyl, propionyl, butyryl), a sulfonyl group (eg, methylsulfonyl, phenylsulfonyl), an acylamino group, a sulfonylamino group, an acyloxy group (eg, acetoxy, benzoxy), a carboxyl group, a cyano group, a sulfo group, and an amino group. included. As the substituent, those not containing a halogen atom are preferable.

[0210] Specific examples of the acid anhydride are shown below, but the present invention is not limited thereto.

[0211]

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[0212]

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These acid anhydrides may be used alone or in combination of two or more. The amount of addition is not particularly limited, but is preferably in the range of 1 × 10 ⁻⁶ to 1 × 10 ⁻² mol / m ² , and more preferably 1 × 10 ⁻⁵ to 1 × 10 ⁻³ mol / m 2.
It is in the range of ² .

In the present invention, the acid anhydride can be added to any layer on the photosensitive layer side of the support such as a photosensitive layer, a surface protective layer, an intermediate layer, an antihalation layer and an undercoat layer. It can be added to one layer or two or more layers. Especially, it is preferable to add to the same layer as the epoxy compound of the present invention. Further, it can be added to any layer on the opposite side of the support from the photosensitive layer. In the case of a photosensitive material having a photosensitive layer on both sides, any layer may be used.

In the present invention, the organic silver salt is a reducible silver source, and is preferably a silver salt of an organic acid or a hetero organic acid, especially a long-chain (10 to 30 carbon atoms, preferably 15 to 25 carbon atoms).
Silver salts of aliphatic carboxylic acids and nitrogen-containing heterocyclic compounds are preferred. Organic or inorganic complexes in which the ligand has a value of 4.0 to 10.0 as the total stability constant for silver ions are also preferred. Examples of these suitable silver salts include the aforementioned R
D17029 and 29996, and include the following.

Silver salts of organic acids, for example, gallic acid, oxalic acid,
Silver salts such as behenic acid, stearic acid, arachidic acid, palmitic acid and lauric acid. Silver carboxyalkylthiourea salts, for example, silver salts such as 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, and aldehydes with hydroxy-substituted aromatic carboxylic acids Silver salts or complexes of polymer reaction products, for example, silver salts of reaction products of aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.) and hydroxy-substituted acids (for example, salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid) Or complexes, silver salts or complexes of thiones, for example, 3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-2-thione, and 3-carboxymethyl-4-thiazoline-2
Silver salts or complexes such as -thione, imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole, 3-amino-5-benzylthio-1,2,2;
Complexes or salts of silver and a nitrogen acid selected from 4-triazole and benzotriazole, silver salts such as saccharin and 5-chlorosalicylaldoxime, and silver salts of mercaptides. Among them, preferred silver salts include silver behenate, silver arachidate and silver stearate.

The organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound which forms a complex with silver, and can be obtained by a forward mixing method, a reverse mixing method, a simultaneous mixing method, and a method described in JP-A-9-12764.
A controlled double jet method as described in No. 3 is preferably used. For example, an organic acid alkali metal salt soap (eg, sodium hydroxide, potassium hydroxide, etc.)
After preparing sodium behenate, sodium arachidate, etc., the above-mentioned soap and silver nitrate are mixed by a controlled double jet method to produce an organic silver salt crystal. At that time, silver halide grains may be mixed.

In the present invention, the organic silver salt has an average particle size of 1
It is preferably 0 μm or less and monodispersed.
The average particle size of the organic silver salt refers to the diameter of a sphere equivalent to the volume of the organic silver salt particles when the particles of the organic silver salt are, for example, spherical, rod-shaped, or tabular particles. Average particle size is 0.05 μm to 10 μm, preferably 0.05 μm to
5 μm, particularly preferably 0.05 μm to 1.0 μm. The monodispersion has the same meaning as that of silver halide, and preferably has a monodispersity of 1 to 30.

In the present invention, the organic silver salt preferably has tabular grains containing at least 60% of the total organic silver.
In the present invention, the tabular grains mean those having an aspect ratio (abbreviated as AR) of 3 or more, which is a ratio between the average particle diameter and the thickness, that is, the following formula.

AR = Average particle size (μm) / thickness (μm) In order to form the organic silver salt into these shapes, crystals of the organic silver salt are dispersed and pulverized with a ball mill or the like using a binder or a surfactant. Obtained by: Within this range, a photosensitive material having a high density and excellent image storability can be obtained.

In the present invention, in order to prevent devitrification of the light-sensitive material, the total amount of silver halide and organic silver salt is preferably 0.5 g or more and 2.2 g or less per m ² in terms of silver. . With this range, a high-contrast image can be obtained.

The photothermographic material of the present invention, which forms a photographic image by heat development, comprises a reducible silver source (organic silver salt), a photosensitive silver halide, a reducing agent and, if necessary, silver. It is preferable that the photothermographic material contains a color toning agent which suppresses the color tone of the present invention in a state of being usually dispersed in an (organic) binder matrix. The photothermographic material of the present invention is stable at room temperature, but is exposed to high temperature (for example,
(0 ° C.). Heating generates silver through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This oxidation-reduction reaction is accelerated by the catalytic action of the latent image generated on the silver halide upon exposure. The silver formed by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image. This reaction process proceeds without supplying a processing liquid such as water from the outside.

Examples of suitable toning agents for use in the present invention include R
D17029 discloses the following.

Imides (for example, phthalimide); cyclic imides, pyrazolin-5-ones, and quinazolinones (for example, succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and , 4-thiazolidinedione); naphthalimides (e.g., N-hydroxy-1,8-naphthalimide); cobalt complexes (e.g., hexaamminetrifluoroacetate of cobalt); mercaptans (e.g., 3-mercapto-1,2,2 4-triazole); N
-(Aminomethyl) aryldicarboximides (eg, N- (dimethylaminomethyl) phthalimide);
Blocked pyrazoles (eg, N, N′-hexamethylenebis (1-carbamoyl-3,5-dimethylpyrazole)); isothiuronium
onium) derivatives and certain photobleaches (eg, 1,8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2
-(Tribromomethylsulfonyl) benzothiazole combination); phthalazinone, a phthalazinone derivative or a metal salt of these derivatives (for example, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-
Dimethyloxyphthalazinone and 2,3-dihydro-
1,4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, 6-chlorophthalazinone and sodium benzenesulfinate or 8-methylphthalazinone and sodium p-trisulfonate); a mixture of phthalazine and phthalic acid Combinations; phthalazine (including phthalazine adducts) and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivative and its anhydrides (e.g., phthalic acid, 4-methylphthalic acid, -Nitrophthalic acid and tetrachlorophthalic anhydride); quinazolinediones, benzoxazine, naphthoxazine derivatives; benzoxazine-2,4
-Diones (for example, 1,3-benzoxazine-2,
4-dione); pyrimidines and asymmetric triazines (eg, 2,4-dihydroxypyrimidine), and tetraazapentalene derivatives (eg, 3,6-dimercapto-1,4-diphenyl-1H, 4H-2, 3a, 5, 6
a-tetraazapentalene). Preferred toning agents are phthalazinone or phthalazine.

The photothermographic material of the present invention may contain an antifoggant. Mercury compounds known from, for example, U.S. Pat. No. 3,589,903 as effective antifoggants are environmentally undesirable. For this reason, non-mercury antifoggants have been studied for a long time. Non-mercury antifoggants include, for example, U.S. Pat. Nos. 4,546,075 and 4,452,885 and JP-A-59-5723.
No. 4 is preferred.

Particularly preferred non-mercury antifoggants are disclosed in US Pat. Nos. 3,874,946 and 4,756,993.
No.9, -C (X ₁ )
(X ₂ ) A heterocyclic compound having one or more substituents represented by (X ₃ ) (where X ₁ and X ₂ are halogen and X ₃ is hydrogen or halogen). Examples of suitable antifoggants include JP-A-9-288328, paragraph [0030].
To [0036] are preferably used.

Examples of another preferred antifoggant include JP-A-9-90550, paragraph [006].
2] to [0063]. Further, other suitable antifoggants are disclosed in US Pat.
No. 28,523 and European Patent Nos. 600,587, 605,981 and 631,176.

In the present invention, a matting agent is preferably contained on the photosensitive layer side. In order to prevent the image after thermal development from being damaged, it is preferable to provide a matting agent on the surface of the photosensitive material. Is preferably contained in a mass ratio of 0.5 to 30% based on all binders on the photosensitive layer side.

When a non-photosensitive layer is provided on the opposite side of the photosensitive layer with the support interposed therebetween, it is preferable that at least one layer on the non-photosensitive layer side contains a matting agent, so that the slip property of the photographic material and the adhesion of fingerprints can be improved. For prevention, it is preferable to provide a matting agent on the surface of the photosensitive material, and the matting agent is added in a mass ratio of 0.5 to 4 with respect to all binders of the layer on the side opposite to the photosensitive layer.
It is preferable to contain 0%.

The material of the matting agent used in the present invention may be either an organic substance or an inorganic substance. For example, as inorganic substances, silica described in Swiss Patent No. 330,158, glass powder described in French Patent No. 1,296,995, etc., and alkali described in British Patent No. 1,173,181 etc. An earth metal or a carbonate such as cadmium or zinc can be used as a matting agent. Examples of organic substances include starch described in U.S. Pat. No. 2,322,037, Belgian Patent No. 625,451 and British Patent No. 981,198.
Derivatives, polyvinyl alcohol described in JP-B-44-3643 and the like, Swiss Patent No. 33
No. 0,158, polystyrene or polymethacrylate; U.S. Pat. No. 3,079,257; polyacrylonitrile; U.S. Pat. No. 3,022,16.
An organic matting agent such as polycarbonate described in No. 9 or the like can be used.

The shape of the matting agent may be either regular or irregular, but it is preferably regular and spherical. The size of the matting agent is represented by a diameter when the volume of the matting agent is converted into a sphere. In the present invention, the particle diameter of the matting agent indicates the diameter converted into a sphere.

The matting agent used in the present invention preferably has an average particle size of 0.5 μm to 10 μm, more preferably 1.0 μm to 8.0 μm. The matting agent preferably has a variation coefficient of the particle size distribution of 50% or less, more preferably 40% or less, and particularly preferably 30% or less.

Here, the variation coefficient of the particle size distribution is a value represented by the following equation. (Standard deviation of particle size) / (Average value of particle size) × 100 These matting agents can be contained in any constituent layer. However, in order to achieve the object of the present invention, it is preferable to use a layer other than the photosensitive layer. It is a constituent layer, more preferably the outermost layer as viewed from the support.

The method of adding the matting agent according to the present invention may be a method of dispersing in a coating solution in advance and applying the solution.
A method of spraying a matting agent after the application liquid is applied and before the drying is completed may be used. When a plurality of types of matting agents are added, both methods may be used in combination.

In addition to these materials, various additives may be added to the photosensitive layer, the non-photosensitive layer, or other forming layers according to the purpose. The photothermographic material of the invention may contain, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, a coating aid, and the like. These additives and the other additives mentioned above are RD17029 (19
June 1978 p. Compounds described in 9 to 15) can be preferably used.

As the material of the support used for the photothermographic material, various polymer materials, glass, wool cloth, cotton cloth,
Paper, metal (for example, aluminum) and the like can be mentioned, but in terms of handling as an information recording material, a material that can be processed into a flexible sheet or roll is preferable. Accordingly, the support in the photothermographic material of the present invention is preferably a plastic film (eg, a cellulose acetate film, a polyester film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polyamide film, a polyimide film, a cellulose triacetate film, a polycarbonate film, etc.). In the present invention, a biaxially stretched polyethylene terephthalate film is particularly preferred. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm.
m.

In the present invention, a conductive compound such as a metal oxide and / or a conductive polymer can be contained in the constituent layer in order to improve the chargeability. These may be contained in any layer, but are preferably contained in an undercoat layer, a backing layer, a layer between the photosensitive layer and the undercoat, and the like.
In the present invention, the conductive compounds described in U.S. Pat. No. 5,244,773, columns 14 to 20, are preferably used.

There are no particular restrictions on the method of coating the necessary layers on the light-sensitive material of the present invention, such as a light-sensitive layer, a protective layer, and a back coat layer.
Methods such as dip coating, bar coating, curtain coating, and hopper coating can be used. Further, two or more of these layers may be applied simultaneously. As a solvent for the coating solution, an organic solvent such as methyl ethyl ketone (MEK), ethyl acetate, and toluene is preferably used.

The photothermographic material of the present invention has at least one photosensitive layer on a support. Although only the photosensitive layer may be formed on the support, it is preferable to form at least one non-photosensitive layer on the photosensitive layer. For example, a protective layer is provided on the photosensitive layer to protect the photothermographic layer, and a back coat layer is provided on the opposite surface of the support to prevent sticking between photosensitive materials or in a photosensitive material roll. Is preferably provided. Further, a filter layer may be formed on the same side as or opposite to the photosensitive layer to control the amount or wavelength distribution of light transmitted through the photothermographic layer, or the photosensitive layer may contain a dye or pigment. Good. As the dye, compounds described in JP-A-8-201959 are preferred. The photosensitive layer may be composed of a plurality of layers, or a high-sensitivity layer and a low-sensitivity layer may be provided for adjusting the gradation, and these layers may be combined. Various additives may be added to any of the photosensitive layer, the non-photosensitive layer, and other forming layers.

The photothermographic material of the present invention is stable at room temperature, but is developed by heating to a high temperature after exposure. The heating temperature is preferably from 80 ° C. to 200 ° C., and more preferably from 100 ° C. to 150 ° C. If the heating temperature is lower than 80 ° C., a sufficient image density cannot be obtained in a short time. Adversely affect. By heating, a silver image is generated by an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This reaction process proceeds without any supply of a processing liquid such as water from the outside.

Exposure of the photothermographic material of the present invention can be applied to any light source in the infrared light range. However, in terms of high laser power and transparency of the photosensitive material. , Infrared semiconductor laser (780 nm, 82
0 nm) is more preferably used.

In the present invention, the exposure is preferably performed by laser scanning exposure, but it is preferable to use a laser scanning exposure machine in which the angle between the exposure surface of the photosensitive material and the scanning laser beam does not become substantially perpendicular. .

Here, the expression "substantially not perpendicular" means that the angle is most perpendicular during laser scanning, preferably 55 to 88 degrees, more preferably 60 to 86 degrees, still more preferably. Means 65 ° to 84 °, most preferably 70 ° to 82 °.

When a laser beam is scanned on the photosensitive material, the beam spot diameter on the exposed surface of the photosensitive material is preferably 200 μm or less, more preferably 100 μm or less. It is preferable that the spot diameter is small in that the shift angle of the laser incident angle from the perpendicular can be reduced. Note that the lower limit of the beam spot diameter is 10 μm. By performing such laser scanning exposure, it is possible to reduce image quality deterioration related to reflected light such as occurrence of unevenness like interference fringes.

It is also preferable that the exposure in the present invention is performed by using a laser scanning exposure machine that emits a scanning laser beam that is a vertical multi. Image quality deterioration such as generation of interference fringe-like unevenness is reduced as compared with the scanning laser beam in the longitudinal single mode.

[0246] In order to form a vertical multiple, it is preferable to use a method of combining, using return light, or applying high frequency superposition.
In addition, the vertical multi means that the exposure wavelength is not single, and the distribution of the exposure wavelength is usually 5 nm or more, preferably 10 nm or more.
nm or more. The upper limit of the exposure wavelength distribution is not particularly limited, but is usually about 60 nm.

In the present invention, the photothermographic material preferably contains a certain amount of a solvent. Examples of these solvents include the following.

In the present invention, examples of the solvent include ketones such as acetone, isophorone, ethyl amyl ketone, methyl ethyl ketone, and methyl isobutyl ketone. Methyl alcohol as alcohols,
Examples include ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, diacetone alcohol, cyclohexanol, and benzyl alcohol. Glycols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, hexylene glycol and the like. Examples of ether alcohols include ethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and the like. Examples of ethers include ethyl ether, dioxane, and isopropyl ether. Examples of the esters include ethyl acetate, butyl acetate, amyl acetate, and isopropyl acetate. Examples of the hydrocarbons include n-pentane, n-hexane, n-heptane, cyclohexane, benzene, toluene, xylene and the like. Examples of chlorides include methyl chloride, methylene chloride, chloroform, dichlorobenzene and the like. Monomethylamine as amines,
Dimethylamine, triethanolamine, ethylenediamine, triethylamine and the like can be mentioned. Other examples include water, formamide, dimethylformamide, nitromethane, pyridine, toluidine, tetrahydrofuran, acetic acid and the like. However, it is not limited to these. These solvents can be used alone or in combination of several kinds.

These solvents may be separately contained in the light-sensitive material. However, since the heat-developable light-sensitive material is usually produced by applying an organic solvent-based coating solution, the organic solvent used for preparing the coating solution is usually used. It is preferable to adjust by changing conditions such as temperature conditions in a drying step or the like so that a certain amount of the solvent is contained.
The content of the solvent can be measured by gas chromatography under conditions suitable for detecting the contained solvent.

[0250] The amount of the solvent contained in the photosensitive material according to the present invention 5~1000mg total amount per photosensitive material 1 m ² (by mass), preferably, need to be adjusted so that 100~500mg It is.

When the content is within the above range, a photothermographic material having low fog density while having high sensitivity can be obtained.

[0252]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited by these examples.

Example 1 [Preparation of Subbed Photographic Support] <Preparation of PET Subbed Photographic Support> A commercially available biaxially stretched heat-fixed 175 μm thick optical density of 0.170
(Measured with a densitometer PDA-65 manufactured by Konica Corporation) 8 w / m ^{2 on} both sides of a blue colored PET film
・ A corona discharge treatment is performed for one minute, and the undercoating coating liquid a-1 shown below is applied to one surface so as to have a dry film thickness of 0.8 μm and dried to form an undercoating layer A-1. The surface was coated with the following undercoating coating solution b-1 so as to have a dry film thickness of 0.8 μm and dried to obtain an undercoating layer B-1.

<< Undercoat Coating Solution a-1 >> Butyl Acrylate (30% by Mass) T-Butyl Acrylate (20% by Mass) Styrene (25% by Mass) 2-Hydroxyethyl Acrylate (25% by Mass) Copolymer Latex Solution (Solid content 30%) 270 g C-1 0.6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g Finished to 1 liter with water.

<< Undercoat Coating Solution b-1 >> Copolymer latex liquid of butyl acrylate (40 mass%) styrene (20 mass%) glycidyl acrylate (40 mass%) (solid content 30%) 270 g C-10. 6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g Finish to 1 liter with water. Next, on the upper surfaces of the undercoat layer A-1 and the undercoat layer B-1,
A corona discharge of 8 w / m ² · min. Was performed, and the following lower coating liquid a-2 was coated on the lower coating layer A-1 with a dry film thickness of 0.1 μm.
The lower coating layer B-2 is coated with the following coating liquid b-2 on the lower coating layer B-1 so as to have a dry film thickness of 0.8 μm. Coated as B-2.

<< Coating Solution a-2 for Lower Undercoat >> Gelatin to be 0.4 g / m ² Mass C-1 0.2 g C-2 0.2 g C-3 0.1 g Silica particles (average particle size 3 μm) 0 .1g Finished to 1L with water << Lower coating solution for upper layer b-2 >> C-4 60g Latex liquid containing C-5 as a component (solid content 20%) 80g Ammonium sulfate 0.5g C-6 12g Polyethylene glycol (weight average) (Molecular weight: 600) 6 g Finished to 1 liter with water.

[0257]

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[0258]

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(Preparation of Photosensitive Silver Halide Emulsion A) Water 9
6. Ossein gelatin having an average molecular weight of 100,000 in 00 ml
5 g and 10 mg of potassium bromide were dissolved at a temperature of 35 ° C.
After adjusting the pH to 3.0, 370 ml of an aqueous solution containing 74 g of silver nitrate and (98/2) potassium bromide, potassium iodide and iridium chloride in a molar ratio of 1 × 1 per mole of silver were used.
370 ml of an aqueous solution containing 0 ^-4 mol was added by a controlled double jet method over 10 minutes while maintaining the pAg at 7.7. Then 4-hydroxy-6-methyl-
0.3 g of 1,3,3a, 7-tetrazaindene was added, the pH was adjusted to 5.0 with NaOH, and the average particle size was adjusted to 0.
Cubic silver iodobromide grains having a grain size of 0.6 μm, a coefficient of variation in grain size of 12% and a [100] face ratio of 87% were obtained. After coagulating and sedimenting this emulsion using a gelatin coagulant and desalting, 0.1 g of phenoxyethanol was added, pH 5.9, pAg7.
The composition was adjusted to 5 to obtain a photosensitive silver halide emulsion A.

(Preparation of Powdered Organic Silver Salt A) 111.4 g of behenic acid and 83.8 of arachidic acid were added to 4720 ml of pure water.
g and 54.9 g of stearic acid were dissolved at 80 ° C. Next, while stirring at a high speed, 540.2 ml of a 1.5 M aqueous sodium hydroxide solution was added, and the mixture was sufficiently stirred. Next, 6.9 ml of concentrated nitric acid was added, and the mixture was cooled to 55 ° C. to obtain a sodium organic acid solution. The temperature of the organic acid sodium solution is 55 ° C.
, And the above-mentioned silver halide emulsion (containing 0.038 mol of silver) and 450 ml of pure water were added thereto, followed by stirring for 5 minutes.
Next, 760.6 ml of a 1M silver nitrate solution was added over 2 minutes, and the mixture was further stirred for 20 minutes, and water-soluble salts were removed by filtration. Thereafter, washing with deionized water and filtration were repeated until the conductivity of the filtrate reached 2 μS / cm, and centrifugal dehydration was performed.

The obtained organic silver salt in the form of cake was dried with an air-flow drier flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.) to have a water content of 0.1% in an inert gas (nitrogen gas) atmosphere. The organic silver salt was dried to obtain a dried powder. In addition, an infrared moisture meter was used for measuring the water content of the organic silver salt composition.

(Preparation of photosensitive emulsion dispersion) Polyvinyl butyral powder (Butvar B manufactured by Monsanto)
-79) 14.57 g of methyl ethyl ketone (MEK)
The solution was dissolved in 1457 g, and 500 g of the above-mentioned dry powdered organic silver salt was gradually added and mixed well while stirring with a dissolver type homogenizer. Thereafter, a media type disperser (get) filled with 80% of 1 mm Zr beads (manufactured by Toray)
tzmann), peripheral speed 13m, residence time in mill 3
Minute, and the emulsion is dispersed. 101-
No. 113 was prepared. This preparation step was performed in an inert gas (nitrogen gas 97%) atmosphere.

<Preparation of Infrared Sensitizing Dye Liquid> Among the compounds of the general formulas (1) to (4) which are infrared sensitizing dyes, S-
43, 350 mg, 2-chlorobenzoic acid 13.96 g,
Then, 2.14 g of 5-methyl-2-mercaptobenzimidazole was dissolved in 73.4 ml of methanol in a dark place to prepare an infrared sensitizing dye solution.

<Preparation of Stabilizer Liquid> Stabilizer 1 (1.0 g)
0.5 g of potassium acetate was dissolved in 8.5 g of methanol to prepare a stabilizer solution.

<Preparation of Developer Solution> As a developer, 1,1-
Bis (2-hydroxy-3,5-dimethylphenyl)-
17.74 g of 2-methylpropane was dissolved in MEK and 10
The final developer solution was 0 ml.

<Preparation of Antifoggant Solution> Antifoggant 2
Was dissolved in 5.81 g of MEK to make a final antifoggant solution of 100 ml.

<< Preparation of Coating Solution for Photosensitive Layer >> In an inert gas atmosphere (97% of nitrogen), the photosensitive emulsion dispersion liquid (5
0 g) and 15.11 g of MEK while stirring.
Insulation inhibitor 1 (10% methanol solution) 3
90 μl was added and stirred for 1 hour. In addition, zinc bromide (1
(996% of a 0% methanol solution) was added thereto, followed by stirring for 30 minutes.

Next, 1.416 ml of the infrared sensitizing dye solution and 667 μl of the stabilizer solution were added, and the mixture was stirred for 1 hour. Then, the temperature was lowered to 13 ° C., and the mixture was further stirred for 30 minutes.

While keeping the temperature at 13 ° C., polyvinyl butyral (Butvar B-79, Monsanto)
After adding 13.31 g and stirring for 30 minutes, the following additives were added at 15-minute intervals while stirring was continued.

Phthalazine: 305 mg Tetrachlorophthalic acid: 102 mg 4-Methylphthalic acid: 137 mg Infrared dye 1: 37 mg After adding the above and stirring for 15 minutes, further, an antifoggant solution: 5.47 ml Image stabilizer (general formula) [1], [2]): Refer to Table 1. Developer solution: 14.06 ml Crosslinking agent, etc .: Refer to Table 1. 10% MEK solution: 1.60 ml was sequentially added and stirred to obtain a photosensitive layer coating solution.
Drying was performed at 75 ° C. for 5 minutes. In the drying step, in order to prevent an adverse effect due to oxygen or the like, a nitrogen gas stream is kept at zero atmosphere (nitrogen 9).
7%). <Back side coating> Cellulose acetate (10% methyl ethyl ketone solution) 15 ml / m ² Matting agent: Monodispersity 15% Average particle size 10 μm Monodispersed silica 30 mg / m ² <Photosensitive layer side coating> A liquid having the above composition is coated. Silver amount 2 g / m
² was applied. <Surface protective layer> A solution having the following composition was applied on the photosensitive layer.

Methyl ethyl ketone 17 ml / m ² cellulose acetate 2.3 g / m ² matting agent: monodispersity 10%, average particle size 4 μm monodisperse silica 70 mg / m ² Image stabilizer in photosensitive layer coating solution (general formula [1 ],
[2]) and the cross-linking agent (isocyanates and thiocyanates represented by the general formula [8]) are changed as shown in Table 1, and the composition of the gas atmosphere when the sample is sealed in a barrier bag is changed. The photosensitive material sample No. changed as shown in Table 1. 10
1 to 113 were produced.

[0272]

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[0273]

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[0274]

[Table 1]

In Table 1, HDI and HDSI represent hexamethylene diisocyanate and hexamethylene dithioisocyanate, respectively, and VSC represents a vinyl sulfone compound described in Chemical formula 53.

<< Measurement of Solvent Content in Film >> A film area of 46.3 cm ² was cut out, finely chopped to about 5 mm, stored in a dedicated vial, sealed with a septum and an aluminum cap, and then manufactured by Hewlett-Packard Company. It was set on a headspace sampler HP7694. The gas chromatography (GC) connected to the headspace sampler was a Hewlett-Packard type 5971 equipped with a flame ionization detector (FID) as a detector. As main measurement conditions, a headspace sampler heating condition: 120 ° C., 20 minutes,
GC introduction temperature: 150 ° C, Column: DB-6 manufactured by J & W
24, temperature rise: 45 ° C. for 3 minutes → 100 ° C. (8 ° C./min) to obtain a gas chromatogram. The measurement target solvent is MEK,
Methanol, and after storing a certain amount diluted with each butanol of the solvent on the left in a dedicated vial, using the calibration curve created using the peak area of the chromatogram obtained by measuring in the same manner as above The solvent content in the film was obtained.

The organic solvent content of each of the light-sensitive material samples was determined from 101 to 113 after storage under the following condition A by any of the above methods.
^{Was 2} .

<< Exposure and Development Processing >> Exposure was performed by laser scanning from the emulsion side of the photosensitive material using an exposing machine using a semiconductor laser having a wavelength of 800 nm to 820 nm and made into a vertical multi-mode by a high frequency superimposition. At this time, an image was formed by setting the angle between the exposure surface of the photosensitive material and the exposure laser beam to 75 degrees (the unevenness was smaller than when the angle was set to 90 degrees, and the sharpness and the like were unexpectedly good). Image was obtained).

Thereafter, heat development was performed at 110 ° C. for 15 seconds using an automatic developing machine having a heat drum so that the protective layer of the photosensitive material was in contact with the drum surface. At that time, exposure and development were performed in a room conditioned at 23 ° C. and 50% RH. The obtained image was evaluated using a densitometer. The result of the measurement was evaluated by sensitivity (reciprocal of the ratio of the exposure amount giving a density higher by 1.0 than the unexposed portion) and fog. The relative values are shown with the sensitivity of 101 as 100.

<Evaluation of storage stability with time> After the photosensitive material was stored for 10 days under the following conditions A and B, exposure and development were performed under the above conditions, and the obtained images were evaluated with a densitometer. . Dmin under condition A and Dmi under condition B
The difference between n (Dmin (B) -Dmin (A)) was determined and defined as the storage stability of the undeveloped photosensitive material over time. Table 2 shows the results.

Condition A 25 ° C. 55% Condition B 40 ° C. 80% <Evaluation of Image Preservation> As in the evaluation of the photographic performance, the sample which had been left for 10 days under the preservation condition A and developed was further subjected to 25 ° C.
After being left under a fluorescent lamp at 5% for 7 days, the color tone was observed and evaluated based on the following criteria. This is also shown in Table 2.

Rank Evaluation Criteria 5 No problematic color 4 Color that has no practical problem 3 Slightly yellowish color but no problem 2 Color that is unpleasant and possibly problematic 1 Clearly A remarkable change was recognized, and the color tone became a problem in practice.

[0283]

[Table 2]

As is clear from Table 2, the sample according to the present invention has lower fog and superior storage stability over time of the undeveloped photosensitive material as compared with the comparative sample. Is excellent in the storage stability with time of the undeveloped photosensitive material and the image storage stability after the development processing, while having high sensitivity.

By exposing to ultraviolet light or visible light,
It was confirmed that when the antifoggant 2, which is a compound generating a halogen atom as a reactive species, was not used in combination, the above-mentioned image storability and the like were slightly deteriorated.

Example 2 In the same manner as in Example 1, an undercoat layer A-1 and an undercoat layer A-2 were coated on a commercially available biaxially stretched and heat-fixed blue 175 μm-thick blue colored PET film. Was applied, and the undercoat layers B-1 and B-2 were applied to the back side to prepare a photographic support.

Further, a photosensitive silver halide emulsion A and a powdered organic silver salt A were prepared in the same manner as in Example 1 to prepare a photosensitive emulsion dispersion.

Using these, the image stabilizer represented by the general formulas [1] and [2] in Example 1 which is the image stabilizer and the crosslinking agent of the present invention is used.

Except that the epoxy compound represented by the formula [9] and the acid anhydride crosslinking agent represented by the formula [B] were changed as shown in Table 3, the photosensitive material No. 20
1 to 213 were produced.

[0289]

[Table 3]

In the same manner as in Example 1, the storability of the unexposed photosensitive material and the storability of the image were evaluated. Table 4 shows the evaluation results. Sensitivity is based on the photosensitive material reference No. The sensitivity was expressed as a relative value with the sensitivity after development under storage condition A of 201 being 100.

[0291]

[Table 4]

As is clear from Table 4, the sample according to the present invention has lower fog and superior storage stability with time of the undeveloped photosensitive material as compared with the comparative sample. Is excellent in the storage stability with time of the undeveloped photosensitive material and the image storage stability after the development processing, while having high sensitivity.

Example 3 The effect of the oxygen scavenger was examined by the following method.

(Preparation of oxygen-absorbing agent package) 20 g of iron powder having an average particle size of 60 mesh was prepared from a nonwoven fabric made of polypropylene fiber, FSPIO50, basis weight 70 g / m ² , Gurley air permeability 4 seconds / 100 ml (manufactured by Asahi Kasei Corporation). Then, using a Fuji impulse sealer F1-K400-5 type shield device (manufactured by Fuji Seisakusho, sold by Mitsui & Co., Ltd.), an oxygen absorber package was obtained.

(Oxygen absorber package enclosing package) The photothermographic materials of Sample Nos. 108 and 111 obtained in the experiment of Example 1 were cut into 25.4 × 30.5 cm, and each sheet was folded. Hold with interleaf paper made of thin paper,
A sample package was prepared using the sheets as a packaging unit. These samples package an inert gas atmosphere (N ₂ / O ₂ gas volume ratio 8
5/15), the oxygen scavenger package and the photothermographic material were light-tightly packaged in a light-shielding, moisture-proof seal bag. In addition, what was packaged without putting the oxygen scavenger package was also prepared as a comparative sample.

Next, after the above-mentioned packaging, it was stored at room temperature,
After opening on the day, the sensitometry, the storability of the unexposed photosensitive material and the storability of the image were evaluated in the same manner as in Example 1.

The evaluation results are shown in Table 5. The sensitivity was expressed as a relative value with the sensitivity of a comparative sample in which no oxygen scavenger was present as 100.

[0298]

[Table 5]

As is clear from Table 5, the sample stored in the presence of the oxygen scavenger has high sensitivity, low fog, and excellent image storability after the development processing as compared with the comparative sample. .

[0300]

According to the present invention, it is possible to obtain a photothermographic material having high sensitivity, excellent storage stability, and good stability of a formed image.

Claims (17)

[Claims] 1. A storage method comprising storing an image recording / forming material containing an organic silver salt in an inert gas atmosphere having a volume fraction of 85% or more. 2. A storage method comprising storing an image recording / forming material containing an organic silver salt in a gas atmosphere having a volume fraction of oxygen of 15% or less. 3. The method according to claim 1, wherein said inert gas is at least one gas selected from nitrogen, helium and argon. . 4. An image recording / forming material containing an organic silver salt is a photothermographic material.
The storage method according to any one of the above items. 5. The photothermographic material according to claim 4, wherein at least a) an organic silver salt, b) a photosensitive silver halide, and c)
A photothermographic material comprising: a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat; and d) a binder. 6. At least: a) an organic silver salt; b) photosensitive silver halide; c) a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat; d) a binder. E) a photothermographic material containing a crosslinking agent for the binder, and exposing the photothermographic material to ultraviolet light or visible light after thermal development to inactivate the reducing agent; 6. The photothermographic material according to claim 5, further comprising a compound that generates a reactive species other than a halogen atom that can prevent an organic silver salt from being reduced to silver. 7. The photothermographic material according to claim 5, wherein the photosensitive silver halide has been subjected to supersensitization with a mercapto compound. 8. A compound which generates a reactive species other than a halogen atom, which can inactivate a reducing agent by exposing it to ultraviolet light or visible light and make it impossible to reduce an organic silver salt to silver. 8. The photothermographic material according to claim 6, further comprising a compound that generates a halogen atom as a reactive species. 9. The photothermographic material according to claim 6, wherein the reactive species other than the halogen atom is a free radical comprising a plurality of atoms. 10. The photothermographic method according to claim 6, wherein the compound generating a reactive species other than a halogen atom has a carbocyclic or heterocyclic aromatic group. material. 11. The method according to claim 5, wherein the photosensitive silver halide is sensitized with an infrared spectral sensitizing dye.
11. The photothermographic material according to any one of items 10 to 10. 12. The binder according to claim 6, wherein the crosslinking agent for the binder is selected from an epoxy compound and an acid anhydride, an isocyanate compound, and a thioisocyanate compound.
12. The photothermographic material according to any one of items 11 to 11. 13. A laser exposure apparatus wherein an angle between an exposure surface of the photothermographic material and a scanning laser beam does not become substantially perpendicular to the photothermographic material according to claim 5. An image recording method, comprising: 14. A method for recording an image on the photothermographic material according to any one of claims 5 to 12, wherein the exposure is performed by a laser light scanning exposing device in which a scanning laser beam is a vertical multi. Image recording method. 15. any one photothermographic material 5 per photosensitive material 1 m ² of organic solvents according to claim 5-12
An image forming method, wherein heat development is performed in a state where 1000 mg is contained. 16. A storage method comprising storing the photothermographic material according to claim 5 in an inert gas atmosphere having a volume fraction of 85% or more. 17. A method for storing a photothermographic material according to claim 5, wherein the photothermographic material is stored in a gas atmosphere having a volume fraction of oxygen of 15% or less.