JP2000321711A - Heat developable photosensitive material, image recording method and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat developable photosensitive material less liable to fogging in heat development and in long-term preservation and excellent in stability of a silver image after the heat development. SOLUTION: The heat developable photosensitive material contains at least a nonphotosensitive organic silver salt, photosensitive silver halide, a reducing agent capable of reducing the silver ion of the organic silver salt to silver when activated by heat, a binder and a crosslinking agent of the binder and further contains a compound which generates a reactive species other than a halogen atom when exposed to ultraviolet light or visible light after the heat development of the photosensitive material. The reactive species inactivates the reducing agent so that the organic silver salt cannot be reduced to silver by the reducing agent.

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.

Since a photothermographic material contains an organic silver salt, photosensitive silver halide particles, and a reducing agent, fogging is likely to occur not only during the storage period before thermal development and during thermal development, but also during thermal development. There is also a problem that fogging or photolytic silver (print-out silver) is likely to occur during the storage period after the development processing. In particular, in the case of the photosensitive material, after exposure, usually 80 to
Since heat development is only performed at 250 ° C and no fixing is performed, the silver image is discolored by heat or light during long-term storage under conditions where silver halide, organic silver salt and reducing agent remaining in unexposed areas coexist. Was a problem.

Techniques for solving these problems are disclosed in JP-A-6-208192, JP-A-8-267934, US Pat. No. 5,714,311 and 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.

[0007]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce fog which occurs during heat development or when a photothermographic material is stored for a long period of time, and In particular, it is an object of the present invention to provide a photothermographic material and an image recording method which are excellent in stability of a silver image after thermal development.

[0008]

The above object of the present invention is achieved by the following means.

1. At least a non-photosensitive organic silver salt, a light-sensitive silver halide, a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat, a binder, containing a crosslinking agent for the binder. In the photothermographic material, a halogen atom capable of inactivating the reducing agent and excluding the organic silver salt from being reduced to silver by further exposing the photosensitive material to ultraviolet light or visible light after thermal development. A photothermographic material comprising a compound generating a reactive species other than the above.

[0010] 2. 2. The photothermographic material according to the above item 1, wherein the photosensitive silver halide has been subjected to supersensitization with a mercapto compound.

3. By exposing to ultraviolet light or visible light,
Contains a compound that generates a halogen atom as a reactive species in addition to a compound that generates a reactive species other than a halogen atom that can inactivate a reducing agent and prevent the organic silver salt from being reduced to silver. 2. The photothermographic material according to the above item 1, wherein

4. 4. The photothermographic material as described in 1, 2, or 3, wherein the reactive species other than the halogen atom is a free radical comprising a plurality of atoms.

5. 5. The photothermographic material as described in 1, 2, 3 or 4, wherein the compound generating a reactive species other than a halogen atom has a carbocyclic or heterocyclic aromatic group.

6. Wherein the photosensitive silver halide is sensitized with an infrared spectral sensitizing dye.
6. The photothermographic material according to item 3, 4 or 5.

[0015] 7. 7. The photothermographic material according to the above 1, 3, 4, 5, or 6, wherein the crosslinking agent for the binder is selected from an epoxy compound, an acid anhydride, an isocyanate compound, and a thioisocyanate compound.

8. 8. Exposure to the photothermographic material according to any one of the above items 1 to 7 by using a laser exposing machine in which an angle between an exposure surface of the photothermographic material and a scanning laser beam is not substantially perpendicular. An image recording method comprising:

9. 8. An image recording method, wherein an image is recorded on a photothermographic material according to any one of the above items 1 to 7, by using a laser beam scanning exposure device in which a scanning laser beam is a vertical multi-scan laser beam.

10. The photothermographic material is 5 per photosensitive material 1 m ² of the organic solvent according to any one of the 7
An image forming method, wherein heat development is performed in a state where 1000 mg is contained.

11. On a support, at least, a non-photosensitive organic silver salt, a photosensitive silver halide, a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat,
A photothermographic material provided with a photosensitive layer containing an aliphatic dicarboxylic anhydride.

[12] On a support, at least, a non-photosensitive organic silver salt, a photosensitive silver halide, a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat,
A photothermographic material provided with a photosensitive layer containing hydrogenated phthalic anhydride.

13. 13. An image recording method, wherein the photothermographic material according to any one of 11 and 12 is exposed by a laser scanning exposure machine.

14. 13. An image forming method, comprising heating and developing the photothermographic material according to 11 or 12.

The photothermographic material comprises at least a non-photosensitive organic silver salt, a photosensitive silver halide, a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat, a binder, Contains a crosslinking agent for the binder. Therefore, the silver halide as the photoreceptor, the organic silver salt as the silver source and the reducing agent coexist, and the preservability of the photosensitive material is poor. In addition, since the image is not fixed after the development, it has a disadvantage that the storage stability after the development, particularly, the printout when exposed to light is large.

The fact that a reducing agent is present in the light-sensitive material makes it easier for heat fog to be generated by the reaction with the organic silver salt, and that, after development, light in a wavelength region different from light for image recording is used. In addition to the original function that the reducing agent reduces silver ions even when irradiated, the printed out silver from the 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. That is probably the cause.

Accordingly, the present inventors have developed an organic silver salt by inactivating the reducing agent when the image is exposed to ultraviolet light and visible light after the photothermographic material as described below is thermally developed. It has also 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.

As the reducing agent used in the photothermographic material, a reducing agent having a proton such as bisphenols or sulfonamidophenols is used as described later. Compounds that can deactivate the reducing agent by generating possible active species 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.

Accordingly, 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.

In order to provide such free radical-generating compounds with such stability that the generated free radicals can be contacted with the reducing agent for a sufficient time to react with and inactivate the reducing agent, Those having a heterocyclic aromatic group are preferred.

Representative of these compounds are the following biimidazolyl compounds and iodonium compounds.

The biimidazolyl compound has the ability to oxidize a reducing agent remaining after image formation by 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.

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

[0032]

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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.

[0035]

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[0036]

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

[0038]

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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.

[0040] R ⁴ is acetate, benzoate, carboxylate group such as trifluoroacetate and O ^-
Is shown. W represents 0 or 1.

[0041] X ^- is an anionic counterion, as suitable ^{_{examples, CH 3 CO 2 -, CH}} 3 SO 3 - and PF ₆ ^- is.

The [0042] 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].

[0044]

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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-mentioned iodonium compound is described in Org. Sy
n. , 1961 and "Advanced by Fieser
Organic Chemistry "(Reinh
old, N .; Y. , 1961) and a method analogous thereto.

Suitable compounds can be represented by the following general formula:

[0048]

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[0049]

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The amount of the compound represented by the 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].

[0053]

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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, and 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 the 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 acid 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.

[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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The addition amount of these compounds is preferably within a range in which the increase in printout silver due to the formation of silver halide does not cause a problem, and is at most 150% or less relative to the compound which does not generate active halogen radicals. Preferably it is 100% or less.

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 (e.g., 2-hydroxypiperidino-2-cyclohexenone); aminoreductones (e.g., piperidinohexose reductone monoacetate); N-hydroxyurea derivatives (e.g., 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); sulfonamidoanilines (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) Amide oximes; azines (for example, a combination of an aliphatic carboxylic acid aryl hydrazide and ascorbic acid); a combination of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine; a hydroxamic acid; 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).

[0073]

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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.

[0076]

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[0077]

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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 a photosensitive silver halide and an organic silver salt. The photosensitive silver halide grains in the present invention will be described.

The photographic emulsion used in the present invention is described in P.I. 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) generation and grain growth, and these methods may be performed continuously at a time, or nucleus (seed grain) formation and grain growth may be performed. 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 in grain size% = standard deviation of grain size / average grain size × 100 The shape of silver halide grains is cubic, octahedral, tetradecahedral, tabular, spherical, rod-like, Potato-like particles and the like can be mentioned, and in the present invention, cubic particles, octahedral particles, tetradecahedral particles and tabular particles are particularly preferred.

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.

The outer surface of the silver halide grains is not particularly limited, but 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 alkali to heat, 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 dispersion 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. The compound represented by the general formula [5] is preferably present for at least 50% of the time of the nucleation step, more preferably for at least 70% of the time. The compound represented by the general formula [5] may be added as a powder or may be added after being dissolved in a solvent such as methanol. Representative specific examples of the compound represented by the general formula [5] are shown below, but it should not be construed that the invention is limited thereto.

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 (C
H 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 = CH
CO ₂ K (m + n = 8.5) E-4 NaO ₃ SO (C (CH ₃ ) HCH ₂ O) ₁₇ SO ₃ Na

[0097]

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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 raised 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 at 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 subjecting an organic silver salt to 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.

[0103] (1) inorganic halide: halide (wherein M represented by e.g. MX _n, H, NH _4, and represents a metal atom, n represents 1 when the M is H and NH _4, M
When is a metal atom, it represents the same value as its valence. Examples of the metal atom include lithium, sodium, potassium, cesium, magnesium, calcium, strontium, barium, zinc, cadmium, mercury, tin, antimony, chromium, manganese, iron, cobalt, nickel, rhodium, and cerium. ). Further, halogen molecules such as bromine water are also effective.

(2) Onium halides: quaternary ammonium halides such as, for example, trimethylphenylammonium bromide, cetylethyldimethylammonium bromide and trimethylbenzylammonium bromide, and quaternary phosphonium halides such as tetraethylphosphonium bromide And tertiary sulfonium halides such as trimethylsulfonium 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-bromooxazolinone, 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 separately prepared silver halide 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 general formula [ML ₆ ] ^m , M represents a transition metal selected from elements of Groups 6 to 10 of the periodic table, L represents a ligand, and m represents 0,-, 2-, 3-. 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.

Specific examples of the transition metal coordination complex ion are shown below. 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 which 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. Specific compounds for reduction sensitization include 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 of the present invention is preferably subjected to spectral sensitization by absorbing 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 dyes represented by the following formulas (1) to (4).

[0121]

Embedded image

[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}, W₃₁, 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
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, and n21, n22 and n31
And n32 do not become 0 at the same time. p1 and p11
Are each 0 or 1, q1 and q11 are each 1 or
Sum of p1 and q1 and p11 and q11
Does not exceed 2. A more preferred structure among the general formulas (1) and (2) is
It is represented by (1-1) and (2-1).

[0123]

Embedded image

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.

Each substituent 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. 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, etc.).

Specific examples of the aliphatic group in which these hydrophilic groups are substituted include a carboxymethyl group, a carboxyethyl group, a carboxybutyl group, a carboxypentyl group and a carboxypentyl group.
-Sulfate butyl group, 3-sulfopropyl group, 2-
Hydroxy-3-sulfopropyl group, 4-sulfobutyl group, 5-sulfopentyl group, 3-sulfopentyl group, 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 straight-chain or branched group having 5 or less carbon atoms, 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 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 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 substituted and unsubstituted aryl groups include, 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 ones. 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 with 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 with 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 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 carbocycles. 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 aliphatic group described above 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).

[0141] 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), (1-1) and (2-
In the compounds represented by (1), (3) and (4), when a group having a cation or anion charge is substituted, an equivalent amount of an anion or cation is used so that the intramolecular charge is offset. Forms a counter ion. 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 and an organic ammonium ion (for example,
Each ion such as triethylammonium, triethanolammonium, and pyridinium), and inorganic cations (eg, each cation such as lithium, sodium, and potassium)
Specific examples of the acid anion include, for example, a halogen ion (for example, chloride ion, bromine ion, iodine ion, etc.), p-toluenesulfonic acid ion, perchlorate ion, boron tetrafluoride ion, sulfate ion, methyl ion Sulfate ion, ethyl sulfate ion, methanesulfonate ion, trifluoromethanesulfonate ion, hexafluorophosphate ion and the like.

One of these infrared spectral sensitizing dyes of the present invention, which 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 thereof. Is particularly preferably a long-chain polymethine dye characterized by having a sulfinyl group substituted on the benzene ring of a benzoazole ring.

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

[0146]

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[0147]

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[0148]

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[0149]

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[0150]

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[0151]

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[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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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, and the combination of sensitizing dyes is often used particularly for supersensitization. In addition to 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 is 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. In addition to 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.

General 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 it is 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 formula [6].

The heteroaromatic ring includes, for example, a halogen atom (eg, Cl, Br, I), a hydroxy group, an amino group, a carboxyl group, an alkyl group (eg, 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-12 8-mercaptopurine M-13 2-mercapto-4 (3H) -quinazolinone M-147-trifluoromethyl-4- Quinolinethiol M-15 2,3,5,6-tetrachloro- - pyridinethiol 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 (vinylacetal) s (eg, poly (vinylformal) and poly (vinylbutyral)), 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.

[0172] If necessary, the above binders may be used in combination of two or more kinds. 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 the following formulas will be described.

Formula [8] X = C = NL- (N = C = X) _{v In the} formula, v is 1 or 2, and L may be an alkylene, alkenylene, arylene group or alkylarylene group. X is a divalent linking group, and 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 Aromatic diisocyanates, benzene diisocyanates, naphthalene diisocyanates, biphenyl isocyanates, diphenylmethane diisocyanates, triphenylmethane diisocyanates, triisocyanates, tetraisocyanates, adducts of these isocyanates and divalent or 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 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 1 mol of silver.

The isocyanate compound and 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.

[0185]

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[0186]

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[0187]

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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, molecular weight, etc. of the epoxy group. 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.

[0191]

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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.

[0194]

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[0195]

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[0196]

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[0197]

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[0198]

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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 , and 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.

[0202]

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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. The number and molecular weight of the acid anhydride groups are not limited, but the general formula [B]
The compound represented by is preferred.

[0204]

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In the general 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.

Specific examples of these acid anhydrides are shown below, but the present invention is not limited to these.

[0207]

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[0208]

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The preferred addition amount is 10 ^-6 to 10 ^-1 mol /
m ^2, particularly preferably from 10 ^-4 to 10 ^- in the range of ² mol / m ^2.

Further, these acid anhydrides may be used alone or in combination of two or more. 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 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.

Among the compounds represented by the above general formula [B], the aliphatic dicarboxylic anhydrides are not limited to those used in combination with the above-mentioned epoxy compounds and the active species-generating compounds, but may be used alone. Photosensitivity of a photothermographic material provided with a photosensitive layer containing a non-photosensitive organic silver salt, a photosensitive silver halide, and a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat. When contained in a layer, it has a high effect as an antifoggant and has a great effect on suppressing fog and desensitization during storage.

Of the aliphatic dicarboxylic anhydrides, succinic anhydrides and glutaric anhydrides are preferred, and cyclic aliphatic dicarboxylic anhydrides such as 1,2-cyclopentanedicarboxylic anhydride are preferred. , 1,2-cyclohexanedicarboxylic anhydrides and hydrogenated phthalic anhydrides are preferred. Particularly preferred are 1,2-cyclohexanedicarboxylic anhydride and hydrogenated phthalic anhydride. Among these cyclic aliphatic dicarboxylic anhydrides, a trans-form is preferred. Among them, 1,2-cyclohexanedicarboxylic anhydride is particularly preferred, and a trans-form is particularly preferred. Examples of particularly preferred hydrogenated phthalic anhydrides include those listed in the above compound examples, and 1,2,2
3,6-tetrahydrophthalic anhydride, 3,4,5,6-
Tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, maleated methylcyclohexene tetrabasic anhydride, endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, exo
-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride.

Examples of these aliphatic dicarboxylic anhydrides include those listed in the above compound examples, and further include chlorendic anhydride, bicyclo [2,2,2] oct-7-
Ene-2,3,5,6-tetracarboxylic anhydride, N-
Carboxybenzyloxy-L-aspartic anhydride and endo-bicyclo [2,2,2] oct-5-ene-2,3-dicarboxylic anhydride.

In the present invention, the organic silver salt is a reducible silver source, and is a silver salt of an organic acid or a heteroorganic 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 includes a normal 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 (coefficient of variation in particle size distribution) 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 make the organic silver salt into these shapes, the crystal of the organic silver salt is dispersed and pulverized with a ball mill or the like with 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 from 0.5 g to 2.2 g 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 used in the present invention are 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 4,756,99.
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, it is preferable to include a matting agent on the photosensitive layer side, and it is preferable to provide a matting agent on the surface of the photosensitive material in order to prevent the image after thermal development from being damaged. 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 photosensitive 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 side.
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 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 included in the constituent layer in order to improve the chargeability. These may be contained in any of the layers, but are preferably contained in an undercoat layer, a backing layer, a layer between the photosensitive layer and the undercoat layer, 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 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, and if the heating temperature is higher than 200 ° C., the binder is melted and adversely affects not only the image itself but also transportability such as transfer to a roller and a developing machine. Effect. By heating, a silver image is generated by a redox 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 view of the fact that the laser power is high and the photosensitive material can be made transparent. , 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, "not substantially vertical" means that the angle is most vertical during laser scanning, preferably from 55 to 88 degrees, more preferably from 60 to 86 degrees, still more preferably. Means 65 ° to 84 °, most preferably 70 ° to 82 °.

The beam spot diameter on the exposed surface of the photosensitive material when the laser light is scanned on 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.

The exposure in the present invention is also preferably performed using a laser scanning exposure machine that emits a scanning laser beam which 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.

[0245] In order to form a vertical multiple, a method such as combining, using return light, or superimposing a high frequency is preferable.
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,
Examples thereof include dimethylamine, triethanolamine, ethylenediamine, and triethylamine. 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 prepared 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.

The amount of the solvent contained in the light-sensitive material according to the present invention needs to be adjusted so as to be 5 to 1000 mg, preferably 100 to 500 mg, in total (based on mass) per 1 m ² of the light-sensitive material. It is.

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

[0251]

(Preparation of undercoated photographic support)

<Preparation of PET-subtracted 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 PET film colored blue
・ 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 >> Butyl acrylate (40% by mass) Styrene (20% by mass) Glycidyl acrylate (40% by mass) copolymer latex liquid (solid content 30%) 270 g C-1 6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g Finished to 1 liter with water.

Subsequently, the undercoat layer A-1 and the undercoat layer B-1
A corona discharge of 8 w / m ² · min is applied to the upper surface of the lower layer, and the lower layer upper layer coating solution a-2 is coated on the lower layer A-1 so as to have a dry film thickness of 0.1 μm. As the upper layer A-2, the undercoating layer B-1 having an antistatic function is coated on the undercoating layer B-1 with the following undercoating layer coating solution b-2 so as to have a dry film thickness of 0.8 μm.
2 was applied.

<< Coating Solution a-2 for Lower Substrate >> 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 Make up to 1 liter with 1 g water.

<< Undercoat upper layer coating solution b-2 >> C-4 60 g Latex liquid containing C-5 as a component (solid content: 20%) 80 g Ammonium sulfate 0.5 g C-6 12 g Polyethylene glycol (weight average molecular weight 600) 6 g Finish 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 over 10 minutes by a controlled double jet method 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. This emulsion was subjected to coagulation sedimentation using a gelatin coagulant and desalting treatment, followed by addition of 0.1 g of phenoxyethanol, pH 5.9 and pAg7.
By adjusting to 5, photosensitive silver halide emulsion A was obtained.

(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 are repeated until the conductivity of the filtrate becomes 2 μS / cm, centrifugal dehydration is performed, and then drying is performed under a nitrogen stream heated at 37 ° C. until the mass loss does not occur. Organic silver salt A was obtained.

(Preparation of Photosensitive Emulsion Dispersion) Polyvinyl butyral powder (Butvar B manufactured by Monsanto)
-79) 14.57 g of methyl ethyl ketone (MEK)
The mixture was dissolved in 1,457 g, and 500 g of the powdered organic silver salt A was gradually added to the mixture while stirring with a dissolver-type homogenizer, followed by thorough mixing. Thereafter, a media type dispersing machine (gettzmann) filled with 80% of 1 mm Zr beads (manufactured by Toray)
The emulsion was dispersed at a peripheral speed of 13 m and a residence time of 3 minutes in a mill to prepare a photosensitive emulsion dispersion.

<Preparation of Infrared Sensitizing Dye Solution> 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 Photosensitive Layer Coating Solution >> The above-mentioned photosensitive emulsion dispersion (50 g) and 15.11 g of MEK were kept at 21 ° C. while stirring, and 390 μl of antifoggant 1 (10% methanol solution) was added thereto, and the mixture was added for 1 hour. Stirred. Further, 996 μl of zinc bromide (10% methanol solution) was added, and 3
Stirred for 0 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 137 mg After adding the above and stirring for 15 minutes, 5.47 ml of antifoggant solution was further added to the image stabilizer (general formula [1], [ 2)) See Table 1 Developer solution 14.06 ml Cross-linking agent, etc .: See Table 1 1.60 ml of 10% MEK solution was sequentially added and stirred to obtain a photosensitive layer coating solution.
Drying was performed at 75 ° C. for 5 minutes. Note that the drying step was performed under a nitrogen atmosphere without surroundings in order to prevent adverse effects due to oxygen and the like.

<Coating on Back Side> Cellulose acetate (10% methyl ethyl ketone solution) 15 ml / m ² Matting agent: Monodispersity 15% Average particle size 10 μm Monodisperse silica 30 mg / m ² <Coating on photosensitive layer side> 2 g / m of coated silver
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]) were changed as shown in Table 1 to obtain a photosensitive material sample No. 101 to 121 were produced.

[0273]

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[0274]

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[0275]

[Table 1]

<< 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 photographic material sample was determined for each of the photographic material samples from 101 to 121 after storage under the following condition A, and all were determined to be 100 to 120 mg / m 2.
^{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 with the angle between the exposure surface of the photosensitive material and the exposure laser beam being 75 degrees. (Note that an image having less unevenness and unexpectedly good sharpness and the like was obtained compared to the case where the angle was set to 90 degrees.) Thereafter, protection of the photosensitive material was performed using an automatic developing machine having a heat drum. 11 so that the layer and the drum surface are in contact with each other.
The film was thermally developed at 0 ° C. for 15 seconds. 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. 101
Are shown as relative values with the sensitivity of 100 as 100.

<Evaluation of storage stability over time> After the photosensitive material was stored for 7 days under the following conditions, exposure and development were performed under the above conditions, and the obtained images were evaluated using a densitometer.
The difference between Dmin under condition A and Dmin under condition B (Dmi
n (B) -Dmin (A)) was determined as the storage stability of the undeveloped photosensitive material over time. Table 2 shows the results.

Condition A: 25 ° C., 55% RH Condition B: 40 ° C., 80% RH <Evaluation of image storability> Similarly to the evaluation of the photographic performance, the sample subjected to development processing after standing for 7 days under storage conditions A was further subjected to a temperature of 25 ° C. 55
% 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 problem color 4 No problem in practical skill 3 Slightly yellowish color but no problem 2 Color that is unpleasant and may be problematic 1 Clearly A noticeable change was observed, and the color tone became a problem in practice

[0282]

[Table 2]

As is clear from Table 2, the sample according to the present invention is superior in the aging stability of the undeveloped photosensitive material and the image storability after development processing, while having high sensitivity, as compared with the comparative sample.

Example 2 (Claims 1, 4, 5, 6, 7,
Examples for Examples 8 and 9) In the same manner as in Example 1, the undercoating layers A-1 and A-2 were heat-developed on a commercially available biaxially-stretched heat-fixed blue colored PET film having a thickness of 175 μm and subjected to heat development. The undercoat layers B-1 and B-2 were applied to the side on which the layers were to be provided, and the undercoat layers B-1 and B-2 were provided on the back side, to produce a photographic support.

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

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
Nos. 1-221 were produced.

[0287]

[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.

[0289]

[Table 4]

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

Example 3 (Claims 2, 4, 5, 6, 7,
Examples for Examples 8 and 9) In the same manner as in Example 1, the undercoating layers A-1 and A-2 were heat-developed on a commercially available biaxially-stretched heat-fixed blue colored PET film having a thickness of 175 μm and subjected to heat development. The undercoat layers B-1 and B-2 were applied to the side on which the layers were to be provided, and the undercoat layers B-1 and B-2 were provided on the back side, to produce a photographic support.

Also, 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.

However, a solution prepared by removing or containing 5-methyl-2-mercaptobenzimidazole (supersensitizer M-4) as a supersensitizer from an infrared sensitizing dye solution was prepared. Further, the image stabilizer and the crosslinking agent represented by the general formulas [1] and [2] of the present invention used in these are changed as shown in Table 5,
The photosensitive material No. 1 was used to check the effect of the supersensitizer. 301-
321 was produced.

[0294]

[Table 5]

In the same manner as in Example 1, sensitometry, the storability of the unexposed photosensitive material and the storability of the image were evaluated. Table 6 shows the evaluation results. Sensitivity is photosensitive material N
o. The sensitivity was expressed as a relative value with the sensitivity after development under the storage condition A of 301 as 100.

[0296]

[Table 6]

As is clear from Table 6, the sample containing the supersensitizer according to the present invention has higher sensitivity than the comparative sample containing no supersensitizer and the comparative sample in the present invention. It has excellent storage stability over time of an undeveloped photosensitive material and image storage stability after development processing.

Example 4 (Examples for Claims 3, 6, 8, and 9) In the preparation of the infrared sensitizing dye solution, the infrared sensitizing dye S
Sample No. 3 having different kinds of dyes was prepared in the same manner as in Example 1 except that the infrared sensitizing dyes shown in Table 7 (addition amount: 5 × 10 ⁻⁴ mol for all dyes) were used. 401-41
No. 1 was prepared, and the performance of the infrared sensitizing dye in the photothermographic material according to the present invention was evaluated.

[0299]

Embedded image

That is, the sample No. The crosslinking agent and the image stabilizer described below were added based on the formulation No. 102. Hexamethylene diisocyanate as a crosslinking agent according to the present invention, 0.6 g of BI-6 and 0.1 g of I-33 as compounds generating active species other than halogen atoms, and 4-38 as a compound generating halogen atoms. 0.2 g
Each was added. Each sample was evaluated in the same manner as in Examples 1, 2, and 3 except that the storage stability over time was changed to 9 days.

[0301]

[Table 7]

As can be seen from the results shown in Table 7, the effect of improving the storage stability according to the present invention is commonly exhibited in a system containing various infrared sensitizing dyes. It turns out that it is remarkable. The sensitivity was No. 40
The sensitivity of 1 was set to 100 and expressed as relative sensitivity.

Example 5 (Examples for Claims 11 and 12) Sample No. 101 except that the preparation of the photosensitive layer coating solution was changed to 8.0 ml of the antifoggant 2 solution and the crosslinking agent was changed as shown in Table 8. Samples 502 to 516 were prepared in the same manner as described above, and were exposed and developed in the same manner as in Example 1. That is, the fog and relative sensitivity of each sample after storage under storage conditions A and B were measured. Table 8 shows the results. As for the sensitivity, the sensitivity of 101 of the material stored under the storage condition B was 1
Each sample was represented by a relative sensitivity of 00.

[0304]

[Table 8]

In the sample containing no aliphatic carboxylic acid anhydride, the fog increase under the storage condition B was large,
Further, the sensitivity of the sample stored under the storage condition B is also reduced.
In particular, in the case of using tetrachlorophthalic anhydride, the sensitivity under storage condition B is greatly reduced. On the contrary, in the sample using the aliphatic carboxylic acid anhydride of the present invention, it is found that the fog increase is small and the sensitivity decrease is small.

[0306]

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 (14)

[Claims] At least a non-photosensitive organic silver salt, a photosensitive silver halide, a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat, a binder, and crosslinking of the binder In a photothermographic material containing an agent, the photoreceptor is further exposed to ultraviolet light or visible light after thermal development to inactivate the reducing agent so that the organic silver salt cannot be reduced to silver. A photothermographic material comprising a compound capable of generating a reactive species other than a halogen atom which can be reacted. 2. The photothermographic material according to claim 1, wherein the photosensitive silver halide has been subjected to supersensitization with a mercapto compound. 3. In addition to 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. 2. The photothermographic material according to claim 1, further comprising a compound that generates a halogen atom as a reactive species. 4. The photothermographic material according to claim 1, wherein the reactive species other than the halogen atom is a free radical comprising a plurality of atoms. 5. The photothermographic material according to claim 1, wherein the compound generating a reactive species other than a halogen atom has a carbocyclic or heterocyclic aromatic group. material. 6. The method according to claim 1, wherein the photosensitive silver halide is sensitized with an infrared spectral sensitizing dye.
6. The photothermographic material according to item 3, 4 or 5. 7. The photothermographic material according to claim 1, wherein the crosslinking agent for the binder is selected from an epoxy compound and an acid anhydride, an isocyanate compound, and a thioisocyanate compound. 8. Laser exposure of the photothermographic material according to claim 1, wherein an angle between an exposure surface of the photothermographic material and a scanning laser beam is not substantially perpendicular. An image recording method comprising performing exposure by a machine. 9. A method for recording an image on the photothermographic material according to claim 1, wherein a scanning laser beam is exposed by a laser beam scanning exposure device having a vertical multi-scan laser beam. Image recording method. 10. 5 per photosensitive material 1 m ² of the photothermographic material is an organic solvent according to any one of claims 1-7
An image forming method, wherein heat development is performed in a state where 1000 mg is contained. 11. A support comprising at least a non-photosensitive organic silver salt, a photosensitive silver halide, a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat, and a fat. Photothermographic material provided with a photosensitive layer containing an aromatic dicarboxylic anhydride. 12. A support comprising at least a non-photosensitive organic silver salt, a photosensitive silver halide, a reducing agent capable of reducing silver ions of the organic silver salt to silver when activated by heat, hydrogen, A photothermographic material provided with a photosensitive layer containing fluorinated phthalic anhydride. 13. An image recording method, wherein the photothermographic material according to claim 11 is exposed by a laser scanning exposure machine. 14. An image forming method, wherein the photothermographic material according to claim 11 is heated and developed.