JP2000155383A - Heat-developable material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the heat-developable material negligible in fluctuation of density of an image to be formed, deterioration of color tone, and drop of transmissivity near 400 nm wavelength at the time of development processing. SOLUTION: This heat-developable material contains organic silver grains and reducing agent on a support and >=50% of the total organic silver grains are flat grains having a flat grain ratio TA of >=2 defined by TA=B/D, where B is the projection areas of the flat organic silver grains and D is the thickness of the flat organic silver grains. It is preferred that this heat-developable material contains an oxidant and hydrazine derivative and the average grain diameter of the organic silver grains is 0.3-1.2 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-developable material,
More specifically, the present invention relates to a heat developing material which forms a black and white image suitable for use in the field of printing plate making and medical treatment.

[0002]

2. Description of the Related Art Conventionally, in the field of printing plate making and medical treatment, waste liquids caused by wet processing of image forming materials have become a problem in terms of workability. Weight loss is strongly desired. Therefore, there is a need for a technique relating to photothermographic materials for photographic technology, which enables efficient exposure with a laser imagesetter or laser imager and can form a high-resolution, clear black image. As this technique, for example, US Pat. Nos. 3,152,904 and 3,487,075
And D. Morgan (Dry Silver Photog)
graphic Materials) "(Handbo
ok of Imaging Materials, M
arcelDekker, Inc. 48, 199
As described in 1) etc., an organic silver salt on a support,
Thermal developing materials containing photosensitive silver halide grains, a reducing agent and a binder are known.

[0003] These heat-developable materials are stable at room temperature, but are developed by heating to a high temperature (for example, 80 ° C to 140 ° C) after exposure. That is, heating produces 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 forms a black image, which is in contrast to the unexposed areas, where the image is formed. This reaction process proceeds without supplying a processing liquid such as water from the outside.

When the formed image is used as a printing plate making film, it is necessary to have a high transmittance at 380 to 400 nm in order to expose the PS plate or the like to ultraviolet light by using the film after the heat development as an original. Further, when used in medical films, it is necessary that the color tone, especially the color tone deterioration over time after the treatment, be small. That is, the heat developing material is required to be transparent and have a good color tone without desilvering, fixing or washing after the heat development.

It is known to use an oxidizing agent in a heat-developable material as described in JP-A-7-27881 and JP-A-10-197987 to prevent fog. However, when an oxidizing agent is used, the maximum density (Dmax) decreases over time after the treatment, or the color tone deteriorates over time after the treatment.

By the way, when used for printing plate making, the use of a hydrazine derivative in a heat developing material for high contrast is disclosed in US Pat. Nos. 5,496,695 and 5,46.
No. 4,738 and JP-A-9-90550. However, when such a high contrast agent is contained,
There is a problem that density fluctuation and color tone deterioration become remarkable with the elapse of time after the treatment, and the transmittance at around 400 nm decreases with the elapse of time after the treatment.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has as its object to reduce the density fluctuation and color tone deterioration of a formed image with the lapse of time after development processing.
An object of the present invention is to provide a heat-developable material in which a decrease in transmittance at around 0 nm is not a problem.

[0008]

SUMMARY OF THE INVENTION The object of the present invention is to provide an organic silver particle and a reducing agent on a support, wherein at least 50% of all the organic silver particles contained have a tabular ratio TA of 2 as defined above. The above heat-developable material which is a tabular grain, further containing an oxidizing agent, containing a hydrazine derivative, containing organic silver particles having an average particle diameter of 0.3 to 1.2 μm,
This is achieved by the fact that the particle size distribution of the contained organic silver particles is monodisperse and that silver halide is contained.

In other words, the present inventor has found that the use of organic silver tabular grains can suppress the density fluctuation and color tone deterioration of the formed image over time after processing and the decrease in transmittance at around 400 nm. Invented the invention. Surprisingly, it was also found that stable processing can be performed even with changes in development conditions such as development temperature and time.

Hereinafter, the present invention will be described in detail.

The heat-developable material of the present invention is characterized in that at least 50% of all the organic silver particles contained are tabular grains having a tabular ratio of 2 or more. Here, the tabular ratio TA is the projected area B and the thickness D of the organic silver tabular grains, and TA = B /
D.

The projected area of an organic silver tabular grain is the area of a grain as viewed from directly above when an individual grain is taken with a transmission electron micrograph by a replica method, and the thickness is the length of the shadow of the replica. It can be calculated from this. To measure the area and thickness of these particles, a method of observing with an electron microscope after removing the protective colloid from the formed particles, a method of observing with an electron microscope after removing the binder etc. from the applied sample, coating There is a method of measuring the thickness by observing the cross section of the sample thus obtained, and these can be used alone or in combination.

In the present invention, the organic silver salt is a reducible silver source, and a silver salt of an organic acid or a heteroorganic acid containing a reducible silver ion source, especially a long chain (10 to 30, preferably 15 to 25) And the nitrogen-containing heterocycle is preferred. Organic or inorganic silver salt complexes wherein the ligand has a total stability constant for silver ions of 4.0 to 10.0 are also useful. Examples of suitable silver salts are Research
h Disclosure Nos. 17029 and 29963
And salts thereof: organic acid salts (eg, salts of gallic acid, oxalic acid, behenic acid, arachidic acid, stearic acid, palmitic acid, lauric acid, etc.); silver carboxyalkylthiourea salts (Eg, 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc.); a silver complex of a polymer reaction product of an aldehyde and a hydroxy-substituted aromatic carboxylic acid ( For example, aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.), hydroxy-substituted acids (eg, salicylic acid, benzoic acid, 3,5
-Dihydroxybenzoic acid, 5,5-thiodisalicylic acid)), silver salts or complexes of thioenes (for example, 3- (2
-Carboxyethyl) -4-hydroxymethyl-4-thiazoline-2-thioene and 3-carboxymethyl-
4-thiazoline-2-thioene), imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H
-Tetrazole, 3-amino-5-benzylthio-1,
Complexes or salts of silver with a nitrogen acid selected from 2,4-triazole and benzotriazole; saccharin, 5-
Silver salts such as chlorosalicylaldoxime; and silver salts of mercaptides. Preferred silver sources are silver behenate, silver arachidate and / or 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 forward mixing method, a reverse mixing method, a simultaneous mixing method, and a method described in JP-A-9-12764.
A controlled double jet method as described in No. 3 is preferably used. For example, an organic acid alkali metal salt soap (eg, sodium hydroxide, potassium hydroxide, etc.)
After preparing sodium behenate and sodium arachidate, the above-mentioned soap and silver nitrate are added by a control double jet to prepare crystals of an organic silver salt. At that time, silver halide grains may be mixed.

In the present invention, the thickness of the organic silver tabular grains is preferably from 0.005 μm to 0.2 μm, more preferably from 0.005 μm to 0.2 μm.
μm to 0.15 μm is more preferable, and 0.005 μm to
0.1 μm is more preferred. The preferred flat plate ratio is 2 or more and 200 or less, preferably 3 or more and 100 or less. 50% or more, preferably 55% to 1% of the total number of the organic silver particles
00%, more preferably 60 to 100%, are tabular grains having a tabular ratio of 2 or more.

In the present invention, the method of controlling the plate ratio within the range of the present invention includes controlling the pH, temperature, potential, speed, etc., when adding silver nitrate to the organic acid soap, and adding the organic acid soap to the silver nitrate solution. Method of controlling pH, temperature, potential, speed, etc. at the time of addition, method of controlling pH, temperature, potential, speed, etc., when simultaneously mixing organic acid soap and silver nitrate by controlled double jet method, organic silver There are a method of ripening in a reaction vessel after the formation, a method of dispersing the organic silver with a binder after the formation of the organic silver, and the like, and these can be used alone or in combination. Among them, it is preferable to disperse the organic silver with a binder or an activator by using a dispersing device after the formation of organic silver to form organic silver tabular grains within the scope of the present invention.

In the present invention, the average particle size of the organic silver particles is preferably from 0.2 to 1.2 μm, more preferably from 0.35 to 1 μm. Here, the average particle size is obtained by randomly extracting 300 or more of the above particles, measuring the projected area of each particle by the above-described replica method and the like, expressing the diameter as a circle, and calculating the arithmetic average thereof. The average particle size is determined.

In the present invention, the organic silver particles are preferably monodispersed. The term "monodispersion" used herein has the same meaning as in the case of silver halide described later, and preferably has a monodispersity of 1 to 30. Within this range, a photosensitive material having a high density and excellent image storability can be obtained.

In the present invention, it is not preferable to mix needle-like organic silver particles in order to maintain transparency after processing. In particular, as described in the examples of JP-A-9-68772, when the number of particles having a major axis diameter of more than 1 μm is 50% or more of all the particles, the transparency after treatment is significantly deteriorated. .

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 amount of silver halide relative to the total amount of silver is at most 50% by weight, preferably at most 25%, more preferably between 0.1% and 15%.

The heat-developable material of the present invention contains a reducing agent.
Examples of suitable reducing agents are described in US Pat. No. 3,770,448.
No. 3,773,512 and No. 3,593,86
No. 3, and Research Disclosure Nos. 17029 and 29996, and include the following. Aminohydroxycycloalkenone compounds (for example, 2-hydroxypiperidino-2-cyclohexenone); aminoreductones (re
Ductones) esters (eg, piperidinohexose reductone monoacetate); N-hydroxyurea derivatives (eg, Np-methylphenyl-N-hydroxyurea); hydrazones of aldehydes or ketones (eg, anthracene aldehyde phenylhydrazone) Phosphoramidophenols; Phosphoramidoanilines; Polyhydroxybenzenes (e.g., hydroquinone, t-butyl-hydroquinone, isopropylhydroquinone and (2,5-dihydroxy-phenyl))
Methyl sulfone); sulfhydroxamic acids (eg,
Sulfonamidoanilines (for example, 4- (N-methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (for example, 2-methyl-5- (1-phenyl-5-tetrazolylthio) ) Hydroquinone); Tetrahydroquinoxalines (eg, 1,2,3,4-tetrahydroquinoxaline); Amidooxins; Azines (eg, a combination of an aliphatic carboxylic acid arylhydrazide and ascorbic acid); A combination of hydroxylamine, reductone and / or hydrazine;
Hydroxanoic acids; Combinations of azines and sulfonamidophenols; α-cyanophenylacetic acid derivatives; Combinations of bis-β-naphthol and 1,3-dihydroxybenzene derivatives; 5-pyrazolones; Sulfonamidophenol reducing agents; 2-phenyl Indan-1,3-dione and the like; chroman; 1,4-dihydropyridines (for example, 2,6-dimethoxy-3,5-dicarbethoxy-
1,4-dihydropyridine); bisphenols (for example, bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, bis (6-hydroxy-m-tri) mesitol, 2,2- Screw (4
-Hydroxy-3-methylphenyl) propane, 4,5
-Ethylidene-bis (2-t-butyl-6-methyl) phenol), an ultraviolet-sensitive ascorbic acid derivative and 3
-Pyrazolidones. Among them, particularly preferred reducing agents are hindered phenols. Examples of the hindered phenols include compounds represented by the following general formula (A).

[0022]

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In the formula, R is a hydrogen atom or a group having 1 to 1 carbon atoms.
10 alkyl groups (for example, -C4H9, 2,4,4-
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.

[0025]

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[0026]

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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 heat-developable material of the present invention preferably contains an oxidizing agent. The oxidizing agent used in the present invention may be any oxidizing agent as long as it reduces fog during storage. As such an oxidizing agent, preferably, for example, JP-A Nos. 50-119624 and 50-120328,
No. 51-121332, No. 54-58022, No. 5
Nos. 6-70543, 56-99335 and 59-9
No. 0842, No. 61-129,642, No. 62-129
No. 845, JP-A-6-208191 and 7-5621
Nos. 7-2781, 8-15809, U.S. Pat. Nos. 5,340,712, 5,369,000, 5,464,737, 3,874,946, and 4 Nos. 5,756,999, 5,340,712, European Patent Nos. 605981A1, 622666A1, 631176A1, JP-B-54-165,
And compounds described in U.S. Pat. Nos. 4,180,665 and 4,442,202 can be used, but polyhalogen compounds represented by the following general formula (I) are preferred. It is.

[0029]

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In the formula, A represents an aliphatic group, an aromatic or heterocyclic group, and X ₁ , X ₂ and X ₃ each represent a hydrogen atom or an electron-withdrawing group, and may be the same or different. Y represents a divalent linking group.

The electron-withdrawing group represented by X ₁ , X ₂ and X ₃ is preferably a substituent having a σp value of 0.01 or more, more preferably a substituent having a σp value of 0.1 or more. Regarding the Hammett's substituent constant, Journal of M
edininal Chemistry, 1973, V
ol. 16, No. 11, 1207-1216 etc. can be referred to.

Examples of the electron-withdrawing group include a halogen atom (fluorine atom (σp value: 0.06), a chlorine atom (σp value
Value: 0.23), bromine atom (σp value: 0.23), iodine atom (σp value: 0.18), trihalomethyl group (tribromomethyl (σp value: 0.29), trichloromethyl (σp value) Value: 0.33), trifluoromethyl (σp
Value: 0.54)), cyano group (σp value: 0.66), nitro group (σp value: 0.78), aliphatic / aryl or heterocyclic sulfonyl group (for example, methanesulfonyl (σ
p value: 0.72)), aliphatic / aryl or heterocyclic acyl group (eg, acetyl (σp value: 0.50), benzoyl (σp value: 0.43)), alkynyl group (eg, C ₃ H) ₃ (σp value: 0.09)), aliphatic / aryl or heterocyclic oxycarbonyl group (for example, methoxycarbonyl (σp value: 0.45), phenoxycarbonyl (σp value: 0.45)), carbamoyl group ( σp value:
0.36), a sulfamoyl group (σp value: 0.57) and the like.

X ₁ , X ₂ and X ₃ are preferably electron-withdrawing groups, more preferably halogen atoms (fluorine atom (σp value: 0.06), chlorine atom (σp value: 0.2
3), bromine atom (σp value: 0.23), iodine atom (σ
p value: 0.18)), trihalomethyl group (tribromomethyl (σp value: 0.29), trichloromethyl (σp
Value: 0.33), trifluoromethyl (σp value: 0.5)
4)), cyano group (σp value: 0.66), nitro group (σ
p value: 0.78), an aliphatic / aryl or heterocyclic sulfonyl group (for example, methanesulfonyl (σp value: 0.
72)), an aliphatic / aryl or heterocyclic acyl group (eg, acetyl (σp value: 0.50), benzoyl (σp value: 0.43)), an alkynyl group (eg, C ₃
H ₃ (σp value: 0.09)), aliphatic / aryl or heterocyclic oxycarbonyl group (for example, methoxycarbonyl (σp value: 0.45), phenoxycarbonyl (σ
p value: 0.45)), carbamoyl group (σp value: 0.3
6), a sulfamoyl group (σp value: 0.57) and the like. Particularly preferred is 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 represents a divalent linking group, specifically, -S
O ₂ —, —SO—, —CO—, —N (R ₁₁ ) —SO ₂ —,
_{-N (R 11) -CO -,} - N (R 11) -COO -, - C
OCO-, -COO-, -OCO-, -OCOO-,-
SCO -, - SCOO -, - C (Z 1) (Z 2) -, represents an alkylene, arylene, a divalent heterocyclic, and divalent linking group formed by any combination thereof. R ₁₁
Represents a hydrogen atom or an alkyl group, and is preferably a hydrogen atom. Z ₁ and Z ₂ represent a hydrogen atom or an electron-withdrawing group, but they are not a hydrogen atom at the same time. The electron-withdrawing group is preferably a substituent having a Hammett's substituent constant σp value of 0.01 or more, more preferably 0.1 or more. Preferred examples of the electron-withdrawing group for Z ₁ and Z ₂ are the same as those for X ₁ , X ₂ and X ₃ .

Z ₁ and Z ₂ are preferably a halogen atom, a cyano group or a nitro group. 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 preferably -SO
_2- , -SO-, -CO-, more preferably -S
Represents O ₂ —. n is preferably 1.

The aliphatic group represented by A is a linear, branched or cyclic alkyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20, more preferably 1 to 12; Ethyl, iso-propyl, tert-butyl, n-octyl, n-decyl, cyclopropyl, cyclopentyl, cyclohexyl, etc., and an alkenyl group (preferably having 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, furthermore Preferably it is 2-12, for example, vinyl, allyl, 2-butenyl, 3-pentenyl etc.), alkynyl group (preferably having 2-3 carbon atoms)
0, more preferably 2 to 20, even more preferably 2 to 12
And for example, propargyl, 3-pentenyl and the like. ), And may have a substituent. Examples of the substituent include a carboxy group, an acyl group, an acylamino group, a sulfonylamino group, a carbamoyl group, a sulfamoyl group, an oxycarbonylamino group, and a ureido group. The aliphatic hydrocarbon group is preferably an alkyl group, and more preferably a chain alkyl group. The aromatic group represented by A is preferably an aryl group, and the aryl group is preferably a monocyclic or bicyclic aryl group having 6 to 30 carbon atoms (eg, phenyl, naphthyl, etc.)
And more preferably a phenyl group having 6 to 20 carbon atoms,
More preferably, it is 6 to 12 phenyl groups. The aryl group may have a substituent, and examples of the substituent include a carboxy group, an acyl group, an acylamino group, a sulfonylamino group, a carbamoyl group, a sulfamoyl group, an oxycarbonylamino group, and a ureido group. The heterocyclic group represented by Q is a 3- to 10-membered saturated or unsaturated heterocyclic ring containing at least one of N, O and S atoms, which may be a single ring, And a fused ring may be formed.

The heterocyclic group represented by A is preferably a 5- or 6-membered aromatic heterocyclic group, more preferably a 5- or 6-membered aromatic heterocyclic group containing a nitrogen atom, and further preferably Is a 5- or 6-membered aromatic heterocyclic group containing 1 or 2 nitrogen atoms. Specific examples of the heterocycle include, for example, pyrrolidine, piperidine, piperazine, morpholine, thiophene, furan, pyrrole,
Imidazole, pyrazole, pyridine, 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 and the like can be mentioned. Preferably as a heterocycle, thiophene, furan, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyridazine, triazole, triazine, indole, indazole, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, Tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzothiazole, indolenine,
More preferred are triazine, quinoline, thiadiazole, benzothiazole and oxadiazole, and particularly preferred are pyridine, quinoline, thiadiazole and oxadiazole. A is preferably an aromatic nitrogen-containing heterocyclic group.

Of the above polyhalogen compounds, the compounds represented by the general formula (Ia) are more preferably used.

[0039]

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In the general formula (Ia), A, X ₁ , X ₂ , X ₃
Has the same meaning as in formula (I), and the preferred range is also the same.

The following are specific examples of the polyhalogen compound used in the present invention, but are not limited thereto.

[0042]

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[0043]

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[0044]

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[0045]

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[0046]

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[0047]

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In the present invention, the oxidizing agent is 10 mg / m ²
３3 g / m ^2, preferably 50 mg / m ² 〜
1 g / m ² is more preferred.

In the present invention, the oxidizing agent may be added by any method such as a solution, a powder and a dispersion of solid fine particles, and it is particularly preferable that the solid fine particles are dispersed in the photosensitive layer. Dispersion of solid fine particles can be performed by a known means for fineness (for example, ball mill, vibrating ball mill, sand mill, colloid mill,
Jet mill, roller mill, etc.). At the time of dispersion, a dispersion aid may be used. Further, it may be added as a solution mixed with other additives such as a sensitizing dye, a reducing agent and a color tone agent.

In the present invention, when the hydrazine derivative is contained, its effects can be fully exhibited.

As the hydrazine derivative, a compound represented by the following general formula [H] is preferable.

[0052]

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In the formula, A ₀ represents an aliphatic group, an aromatic group, a heterocyclic group or a -G ₀ -D ₀ group, each of which may have a substituent;
B ₀ represents a blocking group, and A ₁ and A ₂ each represent a hydrogen atom, or one represents a hydrogen atom and the other represents an acyl group, a sulfonyl group, or an oxalyl group. Here, G ₀ is -CO-
Group, -COCO- group, -CS- group, -C (= NG ₁ D ₁ )
— Group, —SO— group, —SO ₂ — group or —P (O) (G ₁ D
₁ ) represents a group, G ₁ represents a mere bond, an —O— group, —S—
Group or -N (D ₁₎ - represents a group, D ₁ is an aliphatic group, an aromatic group, a heterocyclic group or a hydrogen atom, a plurality of D ₁ in the molecule
If they are present, they can be the same or different. D ₀ is a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group,
Represents an amino group, an alkoxy group, an aryloxy group, an alkylthio group, or an arylthio group.

In the general formula [H], the aliphatic group represented by A ₀ preferably has 1 to 30 carbon atoms, and particularly preferably a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. For example, methyl group, ethyl group, t-butyl group, octyl group, cyclohexyl group, benzyl group,
These may be further substituted with a suitable substituent (for example, aryl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, sulfoxy group, sulfonamide group, sulfamoyl group, acylamino group, ureido group, etc.).

In the general formula [H], the aromatic group represented by A ₀ is preferably a monocyclic or condensed ring aryl group, such as a benzene ring or a naphthalene ring, and a heterocyclic group represented by A _0. The group is preferably a heterocyclic ring containing at least one heteroatom selected from nitrogen, sulfur, and oxygen atom in a single ring or a condensed ring, for example, a pyrrolidine ring, an imidazole ring, a tetrahydrofuran ring, a morpholine ring, a pyridine ring, a pyrimidine ring, a quinoline ring, a thiazole ring, a benzothiazole ring, a thiophene ring, a furan ring, and, in -G ₀ -D ₀ group represented by A _0, G ₀ is -CO
Group, -COCO- group, -CS- group, -C (= NG
₁ D ₁₎ - group, -SO- group, -SO ₂ - group or -P (O)
(G ₁ D ₁ ) — represents a group. G ₁ is a mere bond, -O-
A group, —S— group or —N (D ₁ ) — group, wherein D ₁ represents an aliphatic group, an aromatic group, a heterocyclic group or a hydrogen atom, and when a plurality of D ₁ are present in the molecule, They can be the same or different. D ₀ is a hydrogen atom, an aliphatic group, an aromatic group,
It represents a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, an alkylthio group, or an arylthio group, and preferable D ₀ includes a hydrogen atom, an alkyl group, an alkoxy group, an amino group, and the like. Aromatic groups A _0, heterocyclic group or -G ₀ -D ₀ group may have a substituent.

Particularly preferred as A ₀ are an aryl group and a -G ₀ -D ₀ group.

Further, in the general formula [H], A ₀ preferably contains at least one diffusion-resistant group or silver halide-adsorbing group. As the diffusion-resistant group, a ballast group commonly used in immobile photographic additives such as couplers is preferable, and as the ballast group, a photographically inert alkyl group, alkenyl group, alkynyl group, alkoxy group, phenyl group, Examples thereof include a phenoxy group and an alkylphenoxy group, and the total number of carbon atoms in the substituent is preferably 8 or more.

In the general formula [H], examples of the silver halide adsorption promoting group include thiourea, thiourethane group, mercapto group, thioether group, thione group, heterocyclic group, thioamide heterocyclic group, mercapto heterocyclic group, 64-9
No. 0439.

In the general formula [H], B ₀ represents a blocking group, preferably a -G ₀ -D ₀ group, and G ₀ represents-
CO- group, -COCO- group, -CS- group, -C (= NG
₁ D ₁₎ - group, -SO- group, -SO ₂ - group or -P (O)
(G ₁ D ₁₎ - represents a group, -C are preferred G _{0 O} -
Group, -COCO- group, G ₁ is a mere bond,
—O—, —S— or —N (D ₁ ) —, wherein D ₁ represents an aliphatic group, an aromatic group, a heterocyclic group or a hydrogen atom, and a plurality of D ₁ are present in the molecule If so, they may be the same or different. D ₀ represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, an alkylthio group, or an arylthio group, and preferred D ₀ is a hydrogen atom, an alkyl group, an alkoxy group, And an amino group. A ₁ and A ₂ are both hydrogen atoms, or one is a hydrogen atom and the other is an acyl group (acetyl group, trifluoroacetyl group, benzoyl group, etc.), a sulfonyl group (methanesulfonyl group, toluenesulfonyl group, etc.), or an oxalyl group (Such as an ethoxalyl group).

Next, specific examples of the compound represented by the general formula [H] are shown below, but the present invention is not limited thereto.

[0061]

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[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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Other hydrazine derivatives that can be preferably used include compounds H-1 to H-29 described in columns 11 to 20 of US Pat. No. 5,545,505.
U.S. Pat. No. 5,464,738, column 9 to column 1
Compounds 1 to 12 described in 1. These hydrazine derivatives can be synthesized by a known method.

The hydrazine derivative-added layer is a photosensitive layer containing silver halide and / or a layer adjacent to the photosensitive layer.
The addition amount is the particle size of the silver halide grains, the halogen composition,
Although the optimum amount is not uniform depending on the degree of chemical sensitization, the kind of the inhibitor, etc., it is 10 ^-6 mol to 10 mol per mol of silver halide.
^The preferred range is about ^-1 mol, particularly 10 ^-5 mol to 10 ^-2 mol.

The silver halide grains in the present invention function as an optical sensor. In the present invention, in order to suppress white turbidity after image formation and to obtain good image quality, it is preferable that the average particle size is small, and the average particle size is 0.1 μm or less, more preferably 0.01 μm or less.
m to 0.1 μm, particularly preferably 0.02 μm to 0.08 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 of non-normal crystals, for example, in the case of spherical, rod-shaped or tabular grains, it refers to the diameter of a sphere equivalent to the volume of silver halide grains. Further, the silver halide is preferably monodispersed. Here, the monodispersion means that the degree of monodispersion determined by the following equation is 40 or less. The particle size is more preferably 30 or less, and particularly preferably 0.1 or more and 20 or less.

Monodispersity = (standard deviation of particle size) / (average value of particle size) × 100 The shape of the silver halide grains is not particularly limited, but the proportion occupied by the Miller index [100] plane is high. It is preferable that this ratio is 50% or more, further 70% or more,
In particular, it is preferably at least 80%. Miller index [1
The ratio of the [00] plane is determined by utilizing the dependence of the adsorption of the sensitizing dye on the [111] plane and the [100] plane. Tan
i. Imaging Sci. , 29, 165 (1
985).

Another preferred form of silver halide is tabular grains. The term "tabular grain" as used herein means a vertical thickness h μm where the square root of the projected area is a particle size r μm.
Means that the aspect ratio = r / h is 3 or more. Among them, the aspect ratio is preferably 3 or more and 50 or less. The particle size is preferably 0.1 μm or less, more preferably 0.01 μm to 0.08 μm.
These are disclosed in U.S. Patent Nos. 5,264,337 and 5,311.
No. 4,798, 5,320,958, and the like, and tabular grains of interest can be easily obtained. When these tabular grains are used in the present invention, the sharpness of an image is further improved.

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. The photographic emulsion used in the present invention is P.I. Chimie et by Glafkids
Physique Photographique (P
aul Montel, 1967); F. D
Photographic Emuls by uffin
ion Chemistry (The Focal P
Res., 1966); L. Zelikman
Making and Coating by et al
Photographic Emulsion (Th
e Focal Press, 1964) and the like. That is, any of an acidic method, a neutral method, an ammonia method, etc. may be used.
Any of a one-side mixing method, a simultaneous mixing method, a combination thereof and the like may be used. The silver halide may be added to the image forming layer by any method, in which case the silver halide is arranged close to the reducible silver source. Further, the silver halide may be prepared by converting a part or all of the silver in the organic acid silver by the reaction of the organic acid silver and the halogen ion into silver halide, or may be prepared by preparing silver halide in advance. In advance, this may be added to a solution for preparing an organic silver salt, or a combination of these methods is possible, but the latter is preferred. Generally, the silver halide is preferably contained in an amount of 0.75 to 30% by weight based on the organic silver salt.

The silver halide used in the present invention preferably contains metal ions belonging to groups 6 to 11 of the periodic table. As the above metals, W, Fe, Co,
Ni, Cu, Ru, Rh, Pd, Re, Os, Ir, P
t and Au are preferred.

These metal ions can be introduced into silver halide in the form of a metal complex or a metal complex ion. As these metal complexes or metal complex ions, hexacoordinate metal complexes represented by the following general formula are preferable.

In the formula [ML ₆ ] ^m , M is a transition metal selected from the elements of Groups 6 to 11 of the periodic table, L is a ligand, and m is 0,-, 2-, 3- or 4-
Represents 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.

Particularly preferred examples of M are rhodium (Rh), ruthenium (Ru), rhenium (Re), iridium (Ir) and osmium (Os).

Specific examples of transition metal complex ions are shown below, but the present invention is not limited to these.

[0078] 1: [RhCl _6] ^3- 2: [RuCl _6] ^3- 3: [ReCl _6] ^3- 4: [RuBr _6] ^3- 5: [OsCl _6] ^3- 6: [IrCl _6] ^{4 -} 7: [Ru (NO) Cl _5] ^2- 8: [RuBr ₄ (H ₂ O)] ^2- 9: _{[Ru (NO) (H 2 O} ) Cl 4 ] ^- 10: [RhCl ₅ (H ₂ O)] ^2- 11: [Re (NO) Cl _5] ^2- 12: [Re (NO) CN _5] ^2- 13: [Re (NO) ClCN _4] ^2- 14: [Rh (NO) ₂ Cl _4] ^- 15: _{[Rh (NO) (H 2 O} ) Cl 4 ] ^- 16: [Ru (NO) CN _5] ^2- 17: [Fe (CN) _6] ^3- 18: [Rh (NS) Cl _5] ^2- 19: [Os (NO) Cl _5] ^2- 20: [Cr (NO) Cl _5] ^2- 21: [Re (NO) Cl _5] ^- 22: [Os (NS) Cl ₄ (TeCN )] ^2- 23: Ru (NS) Cl _5] ^2- 24: _{[Re (NS) Cl 4 (SeCN} ) ] ^2- 25: [Os (NS) Cl (SCN) 4 ] ^2- 26: [Ir (NO) Cl _5] ^{2 -} 27: [Ir (NS) Cl _5] ^2- these metal ions may be a metal complex or metal complex ions one type, the metal of the same kind of metal or different may be used alone or in combination. The content of these metal ions, metal complexes or metal complex ions, generally is suitably 1 × 10 ^-9 ~1 × 10 ^-2 mol per mol of silver halide, preferably 1 × 10 ^{- It is 8} to 1 × 10 ^-4 mol.

The compounds providing these metals are 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 chemical ripening Although it may be added at any stage before and after sensitization, it is particularly preferable to add at the stage of nucleation, growth and physical ripening, more preferably at the stage of nucleation and growth, and most preferably. It is added at the stage of nucleation.

In the addition, it may be added in several divided portions, may be added uniformly in the silver halide grains, or may be added to silver halide grains.
-306236, 3-167545, 4-76
No. 534, No. 6-110146, No. 5-273683
As described in Japanese Patent Application Laid-Open No. H10-284, etc., the particles can be contained in the particles with a distribution. Preferably, a distribution can be provided inside the particles.

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 in which an aqueous solution of a powder or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together is added to a water-soluble silver salt solution or a water-soluble halide solution during grain formation, or 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 metal ions or complex ions in advance during the preparation of 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 necessary amount of an aqueous solution of a metal compound may be charged into the reaction vessel immediately after the formation of the particles, during or during physical ripening, or at the time of chemical ripening.

The photosensitive silver halide grains can be desalted by washing with water using a method known in the art such as a noodle method or flocculation method.

The photosensitive silver halide grains in the present invention are preferably chemically sensitized. Preferred chemical sensitization methods are sulfur sensitization, selenium sensitization, tellurium sensitization, noble metal sensitization such as gold compounds, platinum, palladium, and iridium compounds, and reduction sensitization as well known in the art. Sensitization can be used.

Binders suitable for the heat-developable material of the present invention are transparent or translucent, generally colorless, and include natural polymer synthetic resins, polymers and copolymers, and other film-forming media such as: gelatin, gum arabic, poly ( Vinyl alcohol), hydroxyethyl cellulose,
Cellulose acetate, cellulose acetate butyrate, poly (vinylpyrrolidone), casein, starch,
Poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly ( Vinyl acetal) (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (ester), poly (urethane), phenoxy resin, poly (vinylidene chloride), poly (epoxide), poly (carbonate) ), Poly (vinyl acetate), cellulose esters, and poly (amide) s. Although it may be hydrophilic or hydrophobic, in the present invention, it is preferable to use a hydrophobic transparent binder in order to reduce fog after thermal development. Preferred binders include polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, polycarbonate, polyacrylic acid, polyurethane and the like.
Among them, polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, and polyester are particularly preferably used.

Another preferred binder is a soluble or dispersible solvent in an aqueous solvent (aqueous solvent).
It is a polymer having an equilibrium water content of 2% by weight or less at 60 ° C. and 60% RH.

When such a polymer is used, a photosensitive layer can be formed using a water solvent containing 30% by weight or more of water as a coating solvent. If the equilibrium water content exceeds 2% by weight, fog due to storage in a high humidity atmosphere will increase. The aqueous solvent in which the polymer is soluble or dispersible is water or a mixture of water and 70% by weight or less of a water-miscible organic solvent. Examples of the water-miscible organic solvent include alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol; cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; ethyl acetate; and dimethylformamide. In the case where the polymer is not thermodynamically dissolved but exists in a so-called dispersed state,
Here, the term aqueous solvent is used. In the present invention, “equilibrium moisture content at 25 ° C. and 60% RH” refers to 2
The weight W _{1 of the} polymer in a moisture-conditioning equilibrium under an atmosphere of 5 ° C. and 60% RH and the weight W _{0 of the} polymer in a completely dry state at 25 ° C.
Can be expressed as follows.

Equilibrium water content at 25 ° C. and 60% RH =
{(W ₁ −W ₀ ) / W ₀ } × 100 (wt%) The actual measurement can be performed as described in Examples below. The polymer is not particularly limited as long as it is soluble or dispersible in the above-mentioned aqueous solvent and has an equilibrium water content of 2% by weight or less at 25 ° C. and 60% RH. Among these polymers, polymers that can be dispersed in an aqueous solvent are particularly preferred.
Examples of the dispersion state include a latex in which polymer solid fine particles are dispersed and a dispersion in which polymer molecules are dispersed in a molecular state or in the form of micelles. The equilibrium water content of the above polymer at 25 ° C. and 60% RH needs to be 2% by weight or less.
It is preferably 0.01% by weight or more and 1.5% by weight or less, more preferably 0.02% by weight or more and 1% by weight or less.

As the above polymer, for example, acrylic resin, polyester resin, polyurethane resin, vinyl chloride resin, vinylidene chloride resin, rubber resin (for example, SBR
Resin or NBR resin), vinyl acetate resin, polyolefin resin, polyvinyl acetal resin, and the like. The polymer may be a homopolymer obtained by polymerizing a single monomer or a copolymer obtained by polymerizing two or more polymers. The polymer may be a linear or branched polymer. Further, the polymers may be crosslinked. The weight average molecular weight M
w is 1000 to 1,000,000, preferably 3000 to
500,000 is desirable. Those having a molecular weight of less than 1000 generally have low film strength after coating, and may cause inconveniences such as cracks in the photosensitive layer.

In the present invention, specific examples of the above-mentioned polymer which can be used as the main binder of the photosensitive layer include the following.

[0091] _{PL-1 - (MMA) 50} - (EA) 45 -
(AA) ₅ - latex (Mw = 3 million in) PL-2 - (2EHA) 30 - (MMA) 50 - (St)
₁₅ - (MAA) ₅ - latex (Mw = 5 million in) PL-3 - (BR) 50 - (St) 47 - (AA) 3 - latex (Mw = 1 million in) PL-4 - (BR) 40 − (DVB) ₁₀ − (St) ₄₅ −
(MAA) ₅ - latex (Mw = 5 million in) PL-5 - (VC) 70 - (MMA) 25 - (AA) 5 -
Latex (Mw = 1.5 million in) PL-6 - (VDC) 60 - (MMA) 30 - (EA) 5
-(MAA) _5- Latex (Mw = 80,000) In the above, abbreviations represent structural units derived from the following monomers, and numerical values are% by weight.

MMA: methyl methacrylate, EA: ethyl acrylate, AA: acrylic acid, 2EHA: 2-
Ethylhexyl acrylate, St: styrene, MA
A: methacrylic acid, BR: butadiene, DVB: divinylbenzene, VC: vinyl chloride, VDC: vinylidene chloride.

Further, such a polymer is commercially available, and the following can be used. For example, as the acrylic resin, Sebian A-4635, 46583, 4601
(Daicel Chemical Industries, Ltd.), Nipol LX
Polyester resins such as 811, 814, 820, 821, and 857 (both manufactured by Nippon Zeon Co., Ltd.) include FI
Netex ES650, 611, 679, 675, 5
25, 801, 850 (Dai Nippon Ink Chemical Co., Ltd.)
And WDsize WHS (manufactured by Eastman Chemical), such as HYDRAN
AP10, 20, 30, 40, 101H, HYDRAN
Examples of vinylidene chloride resins such as HW301, 310, 350 (all manufactured by Dainippon Ink and Chemicals, Inc.) include L50
2, L513, L123c, L106c, L111, L
114 (manufactured by Asahi Chemical Industry Co., Ltd.); vinyl chloride resins such as G351 and G576 (manufactured by Nippon Zeon Co., Ltd.); and polyolefin resins such as Chemipearl S-120, S-300, SA-100, A-10
0, V-100, V-200 and V-300 (all manufactured by Mitsui Petrochemical Co., Ltd.). In the present invention, these polymers may be used alone as the binder,
More than one kind may be blended and used.

In order to protect the surface of the heat-developable material and prevent abrasion, a non-photosensitive layer can be provided outside the photosensitive layer. The binder used for these non-photosensitive layers may be the same as or different from the binder used for the photosensitive layers.

In the present invention, the binder amount of the photosensitive layer is preferably 1.5 to 10 g / m ² in order to increase the speed of thermal development. More preferably, 1.7 to 8 g /
m ² . If it is less than 1.5 g / m ² , the density of the unexposed portion will increase significantly and may not be usable.

In the present invention, a matting agent is preferably contained on the photosensitive layer side, and in order to prevent damage to the image after heat development, it is preferable to provide a matting agent on the surface of the heat-developable material. It is preferable that the matting agent is contained in a weight 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 to prevent slippage of the heat developing material and prevention of fingerprint adhesion. For this reason, it is preferable to provide a matting agent on the surface, and it is preferable that the matting agent is contained in a weight ratio of 0.5 to 40% with respect to all binders in the layer on the side opposite to the photosensitive layer. The shape of the matting agent may be either a fixed shape or an irregular shape, but is preferably a fixed shape, and a spherical shape is preferably used.

In the photothermographic material of the present invention, only a photosensitive layer may be formed on a support.
Preferably, a non-photosensitive layer is formed. In order to control the amount or wavelength distribution of light passing through the photosensitive layer, a filter dye layer may be formed on the same side as the photosensitive layer and / or an antihalation dye layer, a so-called backing layer, may be formed on the opposite side. May contain a dye or a pigment.

These non-photosensitive layers preferably contain the binder and the matting agent described above, and may further contain a sliding agent such as a polysiloxane compound, wax and liquid paraffin.

In the photothermographic material of the present invention, various surfactants can be used as a coating aid. Among them, a fluorine-based surfactant is preferably used for improving charging characteristics and preventing spot-like coating failure.

The heat-developable material of the present invention can contain a color tone agent for suppressing the color tone of silver, if necessary. Examples of suitable toning agents that can be employed in the present invention are Research Disclo.
Sure No. 17029. In addition, a mercapto compound, a disulfide compound, and a thione compound can be contained in order to suppress or promote development to control development, to improve spectral sensitization efficiency, to improve storage stability before and after development, and the like.

The heat developing material of the present invention may contain an antifoggant.

Sensitizing dyes can be used in the heat developing material of the present invention. Useful sensitizing dyes used in the present invention are, for example, Re
search Disclosure Item176
Section 43IV-A (p.23, December 1978), It
em1831X (August 1978, p. 437). In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected.

Various additives may be added to any of the photosensitive layer, the non-photosensitive layer, and other forming layers. For example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, a coating aid, and the like may be used in the heat-developable material of the present invention. These additives and the other additives mentioned above are Re
search Disclosure Item170
29 (p. 9-15, June 1978) can be preferably used.

The support used in the present invention may be a plastic film (for example, polyethylene terephthalate, polycarbonate, polyimide, nylon, cellulose triacetate) in order to obtain a predetermined optical density after development and to prevent deformation of the image after development. , Polyethylene naphthalate).

Among them, a preferred support is a support made of polyethylene terephthalate (hereinafter abbreviated as PET) and a plastic (hereinafter abbreviated as SPS) containing a styrene polymer having a syndiotactic structure. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm.

Further, a heat-treated plastic support may be used. The plastics to be employed include the above-mentioned plastics. The heat treatment of the support means that after forming these supports and before the photosensitive layer is applied, at a temperature higher than the glass transition point of the support by 30 ° C. or more,
Preferably at a temperature higher than 35 ° C., more preferably 40 ° C.
It is preferable to heat at a temperature higher than ℃. However, the effect of the present invention cannot be obtained by heating at a temperature exceeding the melting point of the support.

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

[0108]

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

Example 1 <Preparation of Subbed PET Support> A commercially available biaxially-stretched heat-fixed PET film having a thickness of 175 μm and a blue color density of 0.18 and a blue color of 0.18 was applied on both sides to 8 W / m ² · min. The following undercoating coating solution a-1 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 following antistatic coating liquid b-1 was applied so as to have a dry film thickness of 0.8 μm and dried to obtain an antistatic subbing layer B-1.

<< Undercoat Coating Solution a-1 >> Butyl Acrylate (30 wt%) T-Butyl Acrylate (20 wt%) Styrene (25 wt%) 2-Hydroxyethyl Acrylate (25 wt%) Copolymer Latex Liquid (Solid content 30%) 270 g (C-1) 0.6 g hexamethylene-1,6-bis (ethylene urea) 0.8 g polystyrene fine particles (average particle diameter 3 μm) 0.05 g colloidal silica (average particle diameter 90 μm) 0 .1 g with water 1 l << Undercoat coating solution b-1 >> SnO ₂ / Sb (9/1 weight ratio, average particle size 0.18 μm) Amount to become 200 mg / m ² Butyl acrylate (30% by weight) Styrene ( 20% by weight) Glycidyl acrylate (40% by weight) copolymer latex liquid (solid content 30%) 270 g (C-1) 0.6 g hexa Styrene-1,6-bis subsequently finish 1l in (ethyleneurea) 0.8 g Water, to the undercoat layer A-1 and the upper surface undercoat layer B-1,
A corona discharge of 8 W / m ² · min. Was performed, and the following lower coating liquid a-2 was coated on the lower coating layer A-1 with a dry film thickness of 0.1 μm.
As the undercoating layer A-2, the undercoating layer B-1 is coated with the following undercoating upper layer coating solution b-2 so as to have a dry film thickness of 0.8 μm. Coated as B-2.

<< Coating Liquid a-2 for Subbing Upper Layer >> Gelatin 0.4 g / m ² Weight (C-1) 0.2 g (C-2) 0.2 g (C-3) 0.1 g Silica particles ( (Average particle size: 3 μm) 0.1 g Finished to 1 liter with water << Lower upper layer coating solution b-2 >> (C-4) 60 g Latex solution containing (C-5) as a component (solid content: 20%) 80 g Ammonium sulfate 5 g (C-6) 12 g Polyethylene glycol (weight average molecular weight 600) 6 g Finish to 1 liter with water

[0112]

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[0113]

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(Heat Treatment of Support) In the above-described undercoat drying step of the support, the support was heated at 140 ° C.
Thereafter, it was gradually cooled.

(Preparation of Emulsion A) In 900 ml of water, 7.5 g of inert gelatin and 10 mg of potassium bromide were dissolved and adjusted to a temperature of 35 ° C. and a pH of 3.0.
g of an aqueous solution containing sodium chloride, potassium bromide and potassium iodide in a molar ratio of (60/38/2) and [Ir (NO) Cl ₅ ] salt in an amount of 1 × 10 ⁻⁶ per mole of silver. The mol and rhodium chloride salt were added by the controlled double jet method at 1 × 10 ⁻⁶ mol per mol of silver while keeping the pAg at 7.7. Thereafter, 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, the pH was adjusted to 8 with NaOH, and the pAg was adjusted to 6.5 to perform reduction sensitization to obtain an average particle size of 0.06 μm.
The coefficient of variation of the projected diameter area with a monodispersity of 10% is 8%, [10
0] Cubic silver iodobromide grains having an area ratio of 87% were obtained. This emulsion was subjected to coagulation sedimentation using a gelatin coagulant, and desalting treatment was performed.

(Preparation of Na Behenate Solution) In 945 ml of pure water, 32.4 g of behenic acid, 9.9 g of arachidic acid and 5.6 g of stearic acid were dissolved at 90 ° C. Next, while stirring at a high speed, 98 ml of a 1.5 M aqueous sodium hydroxide solution
Was added. Next, 0.93 ml of concentrated nitric acid was added.
C. and stirred for 30 minutes to obtain a sodium behenate solution.

(Preparation of Preform Emulsion of Silver Behenate and Silver Halide A) 15.1 g of the silver halide emulsion A was added to the above sodium behenate solution, and the pH was adjusted to 8.1 with a sodium hydroxide solution. 147m of 1M silver nitrate solution
was added over 7 minutes, and the mixture was further stirred for 20 minutes, and the water-soluble salts were removed by ultrafiltration. The resulting silver behenate was grains having an average grain size of 0.8 μm and a monodispersity of 8%. After the floc of the dispersion was formed, the water was removed, washed six times with water and removed, and then dried.

(Preparation of Photosensitive Emulsion) The prepared preform emulsion was divided, and a solution of polyvinyl butyral (average molecular weight: 3000) in methyl ethyl ketone (17w) was prepared.
(t%) 544 g and toluene 107 g were gradually added and mixed, and then dispersed at 4000 psi by a media disperser using a 0.5 mm-size ZrO ₂ bead mill.
At this time, the dispersion pressure and time were changed to produce organic silver particles according to the present invention and comparative organic silver particles as shown in Table 1. In addition, measurement of the projected area, thickness, number, and monodispersity of the particles were performed using the material after the coating was formed, and after removing the binder, 500 particles were randomly sampled by the replica method as described above. The results obtained by microscopic observation are used.

The following layers were simultaneously coated on both sides of the support to prepare a sample. The drying was performed at 60 ° C. for 15 minutes.

(Coating on Back Side) Subbing Layer B of Support
A liquid having the following composition was applied on top of No. 1.

Cellulose Cellulose Acetate Butyrate (10% Methyl Ethyl Ketone Solution) 15 ml / m ² Dye-A 7 mg / m ² Dye-B 7 mg / m ² Matting agent: Monodispersity 15% Average particle size 8 μm Monodisperse silica 30 mg / m ² C ₈ F ₁₇ (CH ₂ CH ₂ O) ₁₂ C ₈ F ₁₇ 50 mg / m ² C ₉ F ₁₇ -C ₆ H ₄ —SO ₃ Na 10 mg / m ²

[0122]

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(Coating on Photosensitive Layer Side) Photosensitive Layer 1: A solution having the following composition was coated on the undercoat layer A-1 of the support so that the coated silver amount was 2.4 g / m ² .

Preform emulsion 240 g Sensitizing dye (0.1% methanol solution) 1.7 ml Pyridinium bromide perbromide (6% methanol solution) 3 ml Calcium bromide (0.1% methanol solution) 1.7 ml Oxidant P -37 (10% methanol solution) 1.2 ml 2-Chlorobenzoylbenzoic acid (12% methanol solution) 9.2 ml 2-mercaptobenzimidazole (1% methanol solution) 11 ml Oxidizing agent tribromomethylsulfoquinoline (5% Methanol solution) 17 ml Phthalazine 0.6 g Hydrazine derivative H-26 0.4 g Hardener 0.3 g 4-methylphthalic acid 0.25 g Tetrachlorophthalic acid 0.2 g Developer (20% methanol solution) 29.5 ml Isocyanate compound ( Mobay, Desmodu N3300) 0.5g

[0125]

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Surface protective layer: A solution having the following composition was simultaneously coated on the photosensitive layer.

[0127] Acetone 5 ml / m ² methyl ethyl ketone 21 ml / m ² Cellulose acetate butyrate 2.3 g / m ² methanol 7 ml / m ² phthalazine 250 mg / m ² Matting agent: monodisperse degree of 10% average particle size 4μm monodisperse silica 70 mg / m ² CH ₂ = CHSO ₂ CH ₂ CH ₂ OCH ₂ CH ₂ SO ₂ CH = CH ₂ 35 mg / m ² C ₈ F ₁₇ (CH ₂ CH ₂ O) ₁₂ C ₈ F ₁₇ 100 mg / m ² C ₈ F ₁₇ − C ₆ H ₄ —SO ₃ Na 10 mg / m ² << Exposure and development treatment >>
After cutting into a cm × 30 cm and humidifying at 23 ° C. and 50% RH for 12 hours, 10 sheets were piled up and put in a barrier bag impermeable to oxygen and moisture to obtain 40 times as a thermo-era thermometer.
Warmed for 3 days. It was then exposed through a wedge with a sensitometer having a 810 nm semiconductor laser as an alternative to the imager. Then, at 110 ° C. using an automatic developing machine having a cylindrical heat drum having a radius of 20 cm, 1
Heat development was performed for 5 seconds. At that time, exposure and development at 23 ℃,
The test was performed in a room conditioned at 50% RH.

<< Evaluation of silver tone over time after thermal development processing >>
The heat-developable material subjected to the exposure heat development described above is divided into two parts, and one of them is passed through a thermo machine at 45 ° C. and 60% RH as an evaluation for the age.
After charging for 5 days, the silver tone was visually observed and
A rating was given on a scale.

5: No yellowness at all, cool black tone 4: Slightly yellowish, but hardly noticeable 3: Yellowish, but practically acceptable 2: Strong yellowishness, which is problematic for practical use 1: Yellowishness is remarkably strong, and is not practically suitable.

<< Evaluation of Performance Fluctuation due to Change in Condition of Thermal Development >> The heat-developable material prepared above was exposed, and the temperature of the automatic developing machine was lowered to 105 ° C. and developed for 15 seconds. It was expressed as a percentage of the rate of change based on the sensitivity after 15 seconds of development. The sensitivity here is a relative value of a reciprocal of an exposure amount giving a density of 1.0.

Table 1 shows the above results.

[0132]

[Table 1]

Example 2 <Preparation of silver halide grains> 22 g of phthalated gelatin and 30 mg of potassium bromide were dissolved in 700 ml of water, and the pH was adjusted to 5.0 at a temperature of 35 ° C.
159 ml of an aqueous solution containing 6 g and an aqueous solution containing potassium bromide and potassium iodide in a molar ratio of 92: 8 were added over 10 minutes by a control double jet method while maintaining the pAg at 7.7. Then, 476 ml of an aqueous solution containing 55.4 g of silver nitrate, and an aqueous solution containing 9 μmol / L of dipotassium hexachloridate and 1 mol / L of potassium bromide at a pAg of 7.7 over 30 minutes by a control double jet method. Was added. Thereafter, the pH was lowered to perform coagulation sedimentation and desalting treatment, and 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and pAg of 8.2 to adjust silver iodobromide grains (core of iodine content: 8 mol%, average of 2 mol%, Average size 0.05 μm, projection area variation coefficient 8%, (10
0) Preparation of cubic particles having a face ratio of 79%) was completed.

The thus-obtained silver halide grains were heated to 60 ° C. to obtain 60 mg of dye 1, 30 mg of dye 2, 2 g of 2-mercapto-5-methylbenzimidazole, 4-g of 4-chlorobenzophenone-mole per mole of silver. After addition of 21.5 g of 2-carboxylic acid, sodium thiosulfate 85 μl
And 2,3,4,5,6-pentafluorophenyldiphenylphosphine selenide, 11 μmol, 15 μmol of tellurium compound 1, 3.4 μmol of chloroauric acid, and 260 μmol of thiocyanic acid were added, followed by chemical ripening. Thereafter, the mixture was rapidly cooled to 30 ° C. to obtain desired silver halide grains.

<Preparation of Organic Acid Silver Emulsion> Stearic acid
3 g, 0.5 g of arachidic acid, 8.5 g of behenic acid, and 300 ml of distilled water were mixed at 90 ° C. for 15 minutes, and 31.1 ml of a 1N aqueous solution of NaOH was added over 15 minutes with vigorous stirring, and then the temperature was lowered to 30 ° C. did. Next, 7 ml of a 1N-phosphoric acid aqueous solution was added, and 0.02 g of N-bromosuccinimide was added while stirring more vigorously. In addition, 1
25 ml of an N-silver nitrate aqueous solution was added over 2 minutes, and stirring was continued for 90 minutes. Then, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm.

Thereafter, vacuum drying was performed to obtain a solid of silver organic acid. To 10 g of this solid was added 40 g of a 10% by weight aqueous solution of hydroxypropylcellulose, and 0.1 mmol of pyridinium bromide perbromide and 0.15 mol of calcium bromide dihydrate were added. The silver halide grains thus obtained were added so that the amount of silver halide became 2.5 mmol.
4000p with a media disperser using a bead mill of O ₂
The dispersion was carried out by si to obtain an aqueous dispersion 1 of silver halide / silver organic acid having an average particle size of about 1 μm. At this time, the dispersion pressure and time were changed to produce organic silver particles according to the present invention and comparative organic silver particles as shown in Table 2. In addition, the measurement of the projected area, thickness, number, and monodispersity of the particles was performed using a material after forming the coating film, and after removing the binder, 500 particles were randomly observed by an electron microscope using a replica method. The measurement results are used.

<Preparation of Coating Solution for Photosensitive Layer> Separately, 10 mg of phenylthiosulfonic acid, 8 g of 5-tribromomethylsulfonyl-2-methylthiadiazole, 6 g of 2-tribromomethylsulfonylbenzothiazole, 1,1-bis (2 -Hydroxy-3,5-dimethylphenyl) -3,
150 g of 5,5-trimethylhexane, 5 g of 4,6-ditrichloromethyl-2-phenyltriazine, 2 g of disulfide compound 1 and 7 g of hydrazine derivative H-28
g, 5 g of tetrachlorophthalic acid, and 250 g of an aqueous solution of hydroxypropylcellulose (10% by weight) were mixed and dispersed with a homogenizer to obtain an aqueous dispersion of the above compound.

[0138] 10.3 g of this dispersion was mixed with 50 g of dispersion 1.
And the above-mentioned binder PL-3 was further mixed with 10
g, 3 m of sodium P-dodecylbenzenesulfonate
g, and distilled water was added thereto to prepare a 200 ml coating solution.

[0139]

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<Preparation of Coating Solution for Surface Protective Layer> Lime-treated gelatin 4 g Phthalazine (added with 5 wt% water / methanol = 1/1 (weight ratio) solution) 480 mg 4-methylphthalic acid sodium salt (added with 4% aqueous solution) 240 mg Polymethyl methacrylate fine particles (average particle size: 5 μm) 80 mg C ₇ F ₁₅ COONa 20 mg Sodium P-dodecylbenzenesulfonate 20 mg Distilled water was added to make 100 ml.

<Preparation of Sample> A binder was applied to one surface of the undercoated support subjected to the same antistatic treatment as in Example 1 so that the coating amount was 1.5 g / m ² , and 50 ° C.
For 20 minutes. Thus, a back layer having a thickness of 1.5 μm (dry film thickness) was formed.

Further, a photosensitive layer was coated on the opposite surface so that the coated silver amount was 2.3 g / m ² , and dried at 50 ° C. for 20 minutes. The thickness of the photosensitive layer was 20 μm in dry film thickness.

Subsequently, a surface protective layer was applied thereon so that the coating amount of the binder became 2 g / m ² ,
After drying for 0 minutes, a film having a thickness of 1.6 μm was formed.

<Preparation of Back Layer Coating Solution> Binder (PL-3) 15 g Distilled water 1000 g Sodium p-dodecylbenzenesulfonate 30 mg Epoxy compound (Dinacol EX313, manufactured by Nagase Kasei Kogyo Co., Ltd.) 100 mg Dye a 50 mg Dye b 110 mg Dye c 40 mg Dye d 50 mg Polymethyl methacrylate fine particles (average particle size 5 μm) 20 mg

[0145]

Embedded image

The water content of the binder used in the photosensitive layer of the sample was determined as follows and found to be 0.3% by weight.

<Evaluation of moisture content of photosensitive layer binder> A solution (or dispersion) of the polymer used for the photosensitive layer was applied on a glass plate, dried at 50 ° C for 1 hour, and dried to a thickness of about 100 µm.
Was obtained. However, when a mixture of two or more polymers was used as a binder for the photosensitive layer, a model film in which the polymers were mixed at the same ratio was prepared. The polymer model film thus obtained was peeled from the glass plate and conditioned in an atmosphere of 25 ° C. and 60% RH for 3 days, and the weight (w ₁ ) was measured. Next, a polymer model membrane 2
After being placed in a vacuum at 5 ° C. for 3 days, it was quickly put into a weighing bottle of known weight and its weight (w ₀ = w ₃ −w ₂ ) was measured (where w ₃ is the weight of the polymer model membrane and the weighing bottle, w _Two
Is the weight of the weighing bin). Using w ₀ and w ₁ , the water content was determined by the following equation.

Equilibrium water content at 25 ° C. and 60% RH =
{(W ₁ −w ₀ ) / w ₀ } × 100 (%) <Evaluation of photographic performance> Under an atmosphere of 25 ° C. and 60% RH,
After exposing the photosensitive material with an imager equipped with a 810 nm semiconductor laser, the photosensitive material was heated and developed at 120 ° C. for 20 seconds. The angle between the exposure surface of the photosensitive material and the exposure laser beam at the time of exposure was 80 degrees.

The obtained image was evaluated in the same manner as in Example 1.

Table 2 shows the results.

[0151]

[Table 2]

Example 3 <Preparation of Subbed PET Support> 8 W / m ² was applied to both sides of a biaxially stretched and heat-fixed PET film having a thickness of 120 μm.
・ A corona discharge treatment is performed for one minute, and an undercoating coating solution a-1 of Example 1 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. On the opposite side, the following antistatic undercoat coating solution b-1 of Example 1 was applied so as to have a dry film thickness of 0.8 μm and dried to obtain an antistatic undercoat layer B-1.

(Heat Treatment of Support) In the above-mentioned undercoat drying step of the undercoated support, the support was heated at 140 ° C.
Thereafter, it was gradually cooled.

(Preparation of Emulsion B) Using a double jet method, an average thickness of 70 mol% of silver chloride and the balance of silver bromide of 0.01 was used.
A silver chlorobromide core particle having an average diameter of 0.05 μm was prepared. At the time of mixing the core particles, K ₃ RuCl ₆ was added in an amount of 8 × 10 ⁻⁸ mol per mol of silver. The core particles were shelled using a double jet method. At that time, 3 × 10 ⁻⁷ mol of K ₂ IrCl ₆ was added per mol of silver. The obtained emulsion was silver chloroiodobromide (90 mol% of silver chloride) having a (100) plane of a core / shell type monodisperse (coefficient of variation: 10%) as a main plane having an average thickness of 0.02 μm and an average diameter of 0.09 μm. , 0.2 mol% of silver iodide, the balance being silver bromide). Then, JP-A-2-280139, 287
Desalting was performed using denatured gelatin G-8 (having the amino group in gelatin replaced with phenylcarbamyl) described on page (3).

The EAg after desalting was 190 mV at 50 ° C. The sensitizing dye was added to the obtained emulsion in an amount of 5 per mole of silver.
× 10 ^-4 mol was added, 2-mercaptobenzimidazole was added 4 × 10 ^-4 mol per mol of silver, and 2-4-chlorobenzoylbenzoic acid was added 6 × 10 ^-4 mol per mol of silver. 4-hydroxy-6-methyl-1,
3,3a, 7-tetrazaindene was added at 1 × per mole of silver.
10 ^-3 mol was added, potassium bromide and citric acid were further added to adjust the pH to 5.6, and the EAg to 123 mV. After adding 2 × 10 ^-5 mol of chloroauric acid, 3 × 10 ⁵ mol of inorganic sulfur was added.
Chemical ripening was performed at a temperature of 60 ° C. until the maximum sensitivity was obtained by adding ^-6 mol. After ripening, 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added in an amount of 2 × 10 ^-3 mol and 1-phenyl-5-mercaptotetrazole in an amount of 3 × 10 ^-4 mol per mol of silver. And gelatin.

(Preparation of Na Behenate Solution) In 945 ml of pure water, 32.4 g of behenic acid, 9.9 g of arachidic acid and 5.6 g of stearic acid were dissolved at 90 ° C. Next, while stirring at a high speed, 98 ml of a 1.5 M aqueous sodium hydroxide solution
Was added. Next, 0.93 ml of concentrated nitric acid was added.
C. and stirred for 30 minutes to obtain a sodium behenate solution.

(Preparation of Preform Emulsion of Silver Behenate and Silver Halide A) The above-mentioned silver halide emulsion B was added to the above-mentioned sodium behenate solution in an amount of 10 mol% of the total silver, and a sodium hydroxide solution was added. After adjusting the pH to 8.1, 147 ml of a 1M silver nitrate solution is added over 7 minutes,
After stirring for a minute, ultrafiltration was performed to remove water-soluble salts. The resulting silver behenate had an average grain size of 0.7 μm and a monodispersity of 10
% Particles. After the floc of the dispersion was formed, the water was removed, washed six times with water and removed, and then dried.

(Preparation of Photosensitive Emulsion) Polybutyral (average molecular weight: 300
544 g of 0) methyl ethyl ketone solution (17% by weight)
And 107 g of toluene were gradually added and mixed, and then dispersed in a media dispersing machine using a 0.5 mm-size ZrO ₂ bead mill at 4000 psi in the same manner as in Example 1 to obtain a silver halide / organic material having an average particle size of about 1 μm. An aqueous dispersion of silver acid was obtained. At this time, the dispersion pressure and time were changed to produce organic silver particles according to the present invention and comparative organic silver particles as shown in Table 3. In addition, the measurement of the projected area, thickness, number, and monodispersity of the particles was performed by using the data after forming the coating film, removing the binder, and then randomly observing 500 particles by an electron microscope using a replica method. The measurement results are used.

A sample was prepared in the same manner as in Example 1 except that the coating solution for the photosensitive layer was changed as follows.

(Photosensitive layer 2) A solution having the following composition was applied so that the applied silver amount was 2.4 g / m ² .

Preform emulsion 240 g Sensitizing dye (described above, 0.1% methanol solution) 1.7 ml Pyridinium bromide perbromide (6% methanol solution) 3 ml Calcium bromide (0.1% methanol solution) 1.7 ml Oxidizing agent P-37 (10% methanol solution) 1.2 ml Hydrazine derivative H-27 (10% methanol solution) 1.5 ml 2--4-chlorobenzoylbenzoic acid (12% methanol solution) 9.2 ml 2-mercaptobenzimidazole (1% methanol solution) 11 ml tribromomethylsulfoquinoline (5% methanol solution) 17 ml phthalazine 0.6 g 4-methylphthalic acid 0.25 g tetrachlorophthalic acid 0.2 g Developer A-6 (20% methanol solution) 5 ml isocyanate compound (Movey, Desmodur N3300) 0.5 g Calcium carbonate having an average particle size of 3 μm 0.1 g << Exposure and development processing >> The photothermographic material prepared above is cut into 5 cm × 15 cm, and adjusted at 23 ° C. and 50% RH for 12 hours. After wetting, put 10 sheets each in a barrier bag that is impermeable to oxygen and moisture.
Heated at 0 ° C. for 3 days. Thereafter, exposure and thermal development were performed using Dolev 2dry manufactured by Cytex, which is an image setter equipped with a 780 nm semiconductor laser. Thermal development was performed at 120 ° C. for 25 seconds. At that time, exposure and development were performed in a room conditioned at 23 ° C. and 50% RH.

<< Evaluation of silver tone over time after thermal development processing >>
The heat-developable material subjected to the exposure heat development described above is divided into two parts, and one of them is passed through a thermo machine at 45 ° C. and 60% RH as an evaluation for the age.
Introduced for days. Five-stage evaluation was performed visually as follows.

5: There is no yellowish color, and the color is blackish. 4: A slight yellowishness is observed, but little disturbing. 3: A yellowishness is observed, but there is no practical problem. 2: Strong yellowishness, which is problematic for practical use 1: Yellowishness is remarkably strong, and is not practically suitable.

<< Evaluation of Optical Transmission Density at 400 nm Over Time after Thermal Development >> The heat-developed material subjected to the exposure and heat development described above is divided into two parts, and one of them is 45 ° C.
% RH was put into a thermo machine for 5 days. The sample was
The transmission density at 400 nm of the unexposed portion was measured using a spectrophotometer UV-1200 manufactured by Shimadzu Corporation.
The higher the transmission density, the more likely it is that a longer time is required for the exposure of the PS plate, which is the next step, and that fine dots and lines are not reproduced.

<< Evaluation of Performance Fluctuations Due to Changes in Thermal Development Processing Conditions >> The thermal development material prepared above was exposed, and the temperature of the automatic developing machine was lowered to 110 ° C. and developed for 25 seconds. And expressed as a percentage of the change rate when the sensitivity at the time of was used as a reference. The sensitivity here is a relative value of a reciprocal of an exposure amount giving a density of 1.0.

Table 3 shows the results of the evaluation.

[0167]

[Table 3]

[0168]

According to the heat-developable material of the present invention, the density fluctuation, the color tone deterioration and the 400 nm
A decrease in transmittance in the vicinity can be suppressed, and stable processing can be performed even with changes in development conditions such as development temperature and time.

Claims (6)

[Claims] An organic silver particle and a reducing agent are provided on a support, and 50% or more of the total organic silver particles contained are tabular grains having a tabular ratio TA defined below of 2 or more. Heat developing material. TA = B / D Here, B: projected area of organic silver tabular grains D: thickness of organic silver tabular grains 2. The heat developing material according to claim 1, further comprising an oxidizing agent. 3. The heat-developable material according to claim 1, further comprising a hydrazine derivative. 4. The organic silver particles contained have an average particle size of 0.1.
The heat-developable material according to claim 1, 2 or 3, wherein the thickness is 3 to 1.2 µm. 5. The heat-developable material according to claim 1, wherein the organic silver particles contained have a monodispersed particle size distribution. 6. The heat-developable material according to claim 1, wherein the heat-developable material contains silver halide.