JP2001281793A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material giving a satisfactory image density at a practical reaction temperature (concretely 100-140 deg.C) within a practical reaction time (concretely 1-30 sec) and capable of satisfactorily suppressing the coloration of a white background in storage in a dark place after development. SOLUTION: In the heat developable photosensitive material containing a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one face of the base, a combination of at least one phenol compound and at least one compound which satisfies at least one of the following conditions A and B is contained as the reducing agent. A: A hydrogen bond forming rate constant Kf of 20-4,000. B: The compound has a structure of formula II, III, IV or V (where R21 is an alkyl or the like) or has a phosphoryl group in its molecule.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material. In particular, give sufficient image density, and
The present invention relates to a photothermographic material capable of sufficiently suppressing coloring of a white background when stored in a dark place after development processing.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand in the medical field and the printing plate making field to reduce the amount of processing waste liquid from the viewpoint of environmental protection and space saving. Therefore, a photothermographic material for medical diagnosis and photoengraving that can be efficiently exposed by a laser imagesetter or laser imager and can form a clear black image having high resolution and sharpness Technology is needed. These photothermographic materials eliminate the use of solution processing chemicals, and can provide customers with a simpler and more environmentally friendly photothermographic processing system.

There is a similar demand in the field of general image forming materials. However, medical images require high-quality images with excellent sharpness and granularity due to the need for fine depiction. From the viewpoint, there is a feature that a cool tone image is preferred. At present, various hard copy systems using pigments and dyes, such as ink jet printers and electrophotographs, are distributed as general image forming systems, but none of them is satisfactory as a medical image output system.

On the other hand, thermal image forming systems using organic silver salts are disclosed in, for example, US Pat.
No. 4,570,757 and D.C. Crostabore (K
Loserboer) "Heat Processed Silver System (Ther
mally Processed Silver Systems) "(Imaging
Processings and Materials (Imaging Proce
sses and Materials) Neblette 8th edition, Sturg
e), V. Walworth, A. Shepp
Compilation, Chapter 9, p. 279, 1989). In particular, the photothermographic material generally comprises a catalytically active amount of a photocatalyst (eg, silver halide), a heat developer, a reducible silver salt (eg, an organic silver salt), and if necessary, a color tone agent for controlling the color tone of silver. Is dispersed in a binder matrix. After the image exposure, the photothermographic material is heated to a high temperature (for example, 80 ° C. or higher), and a redox reaction between silver halide or a reducible silver salt (which functions as an oxidizing agent) and the thermal developer causes A black silver image is formed.
The oxidation-reduction reaction is accelerated by the catalytic action of the latent image of silver halide generated by exposure. Therefore, a black silver image is formed in the exposed area. U.S. Patent No. 2,910,377
And Fuji Medical Dry Imager FM-DPL as a medical image forming system using a photothermographic material.

Since the above-mentioned photothermographic material does not undergo a fixing process after the photothermographic process, the heat-reactive organic acid silver salt and the reducing agent are left as they are in the photothermographic material, and the processed material is kept for a long time. There is a problem that the white background is colored when stored. A phenolic reducing agent (for example, European Patent Publication EP0
No. 803764A1, JP-A-51-51933, JP-A-6-3793, etc.) are effectively used, but if the amount of use is reduced, coloring of a white background can be effectively suppressed. . However, if the amount of the o-bisphenol-based reducing agent used is reduced, sufficient image density cannot be obtained, so that it is difficult to achieve both image storability and image density.

[0006]

Accordingly, the present invention provides a sufficient image density at a realistic reaction temperature (specifically, 100 to 140 ° C.) and within a reaction time (specifically, 1 to 30 seconds). Another object of the present invention is to provide a photothermographic material capable of sufficiently suppressing coloring of a white background when stored in a dark place after the development processing.

[0007]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a phenol compound used as a reducing agent in a photothermographic material and a compound having a specific hydrogen bond formation rate constant are used. It has been found that by using in combination, a sufficient image density can be obtained without substantially lowering the reducibility and the image storability is greatly improved, and the present invention has been provided. That is, the present invention, on one side of the support, a photosensitive silver halide,
In a photothermographic material containing a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder, at least one phenol compound as the reducing agent and at least one of the compounds satisfying at least one of the following conditions A and B: A photothermographic material characterized by containing one kind in combination is provided. A: Hydrogen bond formation rate constant Kf is 20 to 4000 B: The following general formula (II), (III), (IV) or (V)
Or has a phosphoryl group in the molecule

Embedded image(In the general formula (II), R^{twenty one}And R^{twenty two}Are independent
Represents an alkyl group; ^{twenty three}Represents an alkyl group or an aryl group.
Or a heterocyclic group. R^{twenty one}, R^{twenty two}And R^{twenty three}Selected from
Two or more may be connected to each other to form a ring
No. In the general formula (III), R³¹And R³²Are each
Independently represents an alkyl group, an aryl group or a heterocyclic group.
R³¹And R³²May be connected to each other to form a ring. one
In the general formula (IV), R⁴¹And R⁴²Are independent
Represents an alkyl group, an aryl group or a heterocyclic group. R⁴³Is
Alkyl group, aryl group, heterocyclic group or -N (R⁴⁴) (R
⁴⁵). R⁴⁴And R⁴⁵Are each independently alkyl
Group, an aryl group or a heterocyclic group. R⁴¹, R⁴²,
R⁴³, R⁴⁴And R⁴⁵Two or more selected from
They may be linked together to form a ring. General formula (V)
And R⁵¹, R⁵², R⁵³, R⁵⁴And R⁵⁵Are independently
Represents a hydrogen atom or a substituent. R⁵¹, R⁵², R⁵³, R⁵⁴
And R⁵⁵Two or more selected from
To form a ring. )

The phenol compound contained in the photothermographic material of the present invention is preferably an o-polyphenol compound, particularly a compound represented by the following formula (I).

Embedded image (Wherein, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom or a group that can be substituted on a benzene ring, and L represents an —S— group Or a -CHR ⁹ -group,
R ⁹ represents a hydrogen atom or an alkyl group. In the compound represented by the general formula (I), R ² , R ⁴ , R ⁵ and R ⁷ are hydrogen atoms, R ¹ and R ⁸ are each independently an alkyl group, and R ³ and R ⁶ are Compounds which are each independently an alkyl group and L is —CHR ⁹ — are preferred. In particular, compounds in which R ¹ and R ⁸ are each independently a secondary or tertiary alkyl group are more preferred.

The photothermographic material of the present invention preferably contains a compound having a hydrogen bond formation rate constant Kf of 70 to 4000. The photothermographic material of the invention preferably contains at least one of an o-polyphenol compound and a compound having a phosphoryl group in a molecule. The compound having a phosphoryl group in the molecule is preferably a compound represented by the following general formula (VI).

Embedded image (In the formula, R ⁶¹ , R ⁶² and R ⁶³ each independently represent an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group.) Indicates a range including the numerical values described before and after it as a minimum value and a maximum value, respectively.

[0010]

DETAILED DESCRIPTION OF THE INVENTION The photothermographic material of the present invention contains a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one surface of a support. It is. The feature of the present invention is (1) containing at least one phenol compound as the reducing agent;
(2) Condition A (hydrogen bond formation rate constant Kf is 20 to 40)
00) and condition B (the above general formula (II),
(III) having a structure represented by (IV) or (V), or having a phosphoryl group in the molecule).

In the present invention, at least one phenol compound is contained as a reducing agent. The use of phenol compounds as reducing agents is described in European Patent Publication EP0803.
No. 764A1, JP-A-51-51933, JP-A-6-3793, etc., which are known phenol compounds and can be used in the present invention. As a result of intensive studies, the present inventors have found that when these known reducing agents are used in combination with the compounds represented by the general formulas (II), (III), (IV), and (V) or the compounds having a phosphoryl group, The inventors have found a surprising effect that image storability is greatly improved while substantially maintaining developability.

As the phenol compound used in the present invention, an o-polyphenol compound is preferred because of its high heat developability. As used herein, “o-polyphenol compound” has the following structure:

Embedded image Any compound may be used as long as it is a reducing agent containing in a molecule. Among them, the compound of the general formula (I) is preferable because it has higher heat developability. The compound of the formula (I) will be described in detail.

In the general formula (I), R ^{1 to} R ⁸ each independently represent a hydrogen atom or a group which can be substituted on a benzene ring. Examples of the group that can be substituted on the benzene ring include a halogen atom, an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an acylamino group, a sulfonamide group, an acyl group,
Examples include a carbamoyl group, a sulfamoyl group, an alkoxycarbonyl group, a sulfonyl group, an alkoxyalkyl group, and an acylaminoalkyl group. Examples of alkyl groups include methyl, ethyl, propyl, butyl,
Examples include an isopropyl group, a t-butyl group, a t-amyl group, a cyclohexyl group, and a 1-methylcyclohexyl group. Examples of the aralkyl group include a benzyl group. R ¹ , R ³ , R ⁶ and R ⁸ each preferably independently represent an alkyl group, more preferably a primary alkyl group having 1 to 20 carbon atoms, a secondary alkyl group having 3 to 20 carbon atoms or a carbon atom. Represents a tertiary alkyl group of the formulas 4 to 20.
These groups may further have a suitable substituent.
As the substituent, a halogen atom, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, a hydroxyl group, an acyloxy group, an amino group, an alkoxycarbonyl group, an acyl group, an acylamino group, an oxycarbonyl group, Carbamoyl group,
Sulfonyl group, sulfamoyl group, sulfonamide group,
Examples include a phosphoryl group and a carboxyl group.

Examples of the primary alkyl group include a methyl group,
Ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group,
Examples include a dodecyl group, a benzyl group, a methoxymethyl group, a 2-methoxyethyl group, a phenethyl group, a hexyloxycarbonylmethyl group, and the like. Preferably, they are a methyl group and an ethyl group. Examples of secondary alkyl groups include isopropyl, cyclohexyl, cyclopentyl,
1-methoxymethyl-ethyl group, 1-butoxyethyl-
And an ethyl group. It is preferably an unsubstituted secondary alkyl group, and particularly preferably an isopropyl group and a cyclohexyl group. Examples of the tertiary alkyl group include a t-butyl group, a t-amyl group, a t-octyl group,
-Methylcyclohexyl group, 1-methylcyclopentyl group, 1-methylcyclopropyl group, 1-methyl-1-phenylethyl group, 1,1-dimethyl-4-hexyloxycarbonylbutyl group and the like. It is preferably an unsubstituted tertiary alkyl group, particularly preferably a t-butyl group and a 1-methylcyclohexyl group, and most preferably a t-butyl group.

R ¹ and R ⁸ each independently represent 2
It is preferably a tertiary alkyl group or a tertiary alkyl group. If a secondary alkyl group or a tertiary alkyl group is selected, the coating amount can be greatly reduced, so that the production cost and labor of the photothermographic material can be greatly reduced. Further, when a secondary alkyl group or a tertiary alkyl group is selected, the image stability becomes extremely poor unless used in combination with a compound having a phosphoryl group, but the image stability is greatly improved when used together according to the present invention. . R ¹ and R ⁸ are preferably tertiary alkyl groups from the viewpoint of development activity.
Further, R ¹ and R ⁸ may be the same or different, but are preferably the same. As R ³ and R ⁶ , an unsubstituted alkyl group is preferable, and specifically, a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a t-butyl group, a t-amyl group, a cyclohexyl group, And a methylcyclohexyl group. More preferably, methyl group, ethyl group, isopropyl group, t
-Butyl group, and a methyl group and an ethyl group are most preferable. R ² , R ⁴ , R ⁵ and R ⁷ each preferably independently represent a hydrogen atom, a halogen atom, or an alkyl group, and more preferably a hydrogen atom.

L is a -S- group or -CHR⁹-Group
Then R⁹Represents a hydrogen atom or an alkyl group. Alkyl
The group is preferably one having 1 to 20 carbon atoms, and may be unsubstituted.
Alternatively, it may be substituted with another group. Unsubstituted alk
Examples of methyl groups include methyl, ethyl, propyl,
Butyl, heptyl, undecyl, isopropyl
Group, 1-ethylpentyl group, 2,4,4-trimethylpe
And an ethyl group. As a substituent of an alkyl group
Is R¹, R^Three, R⁶And R⁸Is the same as R ⁹
More preferably from a hydrogen atom or a carbon number 1
12 unsubstituted alkyl groups, more preferably hydrogen
An atom or an alkyl group having 1 to 7 carbon atoms,
Or a hydrogen atom, a methyl group or an n-propyl group
You. Hereinafter, specific examples of the compound of the general formula (I) in the present invention
As an example, phenolation that can be used in the present invention
The compound is not limited to these.

[0017]

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[0018]

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[0019]

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[0020]

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[0021]

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[0022]

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Specific examples of the phenol compound used in the present invention include, in addition to the above compounds, European Patent Publication No. 0803764A.
No. 1, JP-A-51-51933, JP-A-6-51933.
No. 3793. The addition amount of the phenolic compound is preferably 0.01 to 4.0 g / m ² ,
And more preferably 2.0 to 2.0 g / m ² , more preferably 2 to 40% by mole, and even more preferably 5 to 30% by mole, based on 1 mole of silver on the surface having the image forming layer. .

Next, the hydrogen bond formation rate constant Kf is 20 to
The compound which is 4000 will be described. The hydrogen bond formation rate constant Kf used as a measure of hydrogen bond formation is:
R. W. Taft et al. Am. Chem. So
c., 91, 4794 (1969). These are the reaction rate constants at which hydrogen bonding occurs between p-FC ₆ H ₄ OH and the compound.
Measured using R, IR, or thermodynamic techniques. About the hydrogen bond formation rate constant Kf of the compound,
J. Am. Chem. Soc., 91, 4794 (19
69). In the present invention, Kf is 2
0 to 4000 is preferable, 70 to 4000 is more preferable, 100 to 4000 is still more preferable, and 250 to 200.
0 is particularly preferred. Hydrogen bond formation rate constant Kf is 20 to
Representative examples of the compound having 4000 are shown below.

Kf hexamethylphosphamide 3600 triphenylphosphine oxide 1456 ± 80 4-dimethylaminopyridine 650 ± 90 dimethylsulfoxide 338 ± 7 2,6-dimethyl-γ-pyrone 318 ± 18 tetramethylurea 261 ± 5 trimethyl Phosphate 250 ± 8 N, N-dimethylacetamide 242 ± 6 N, N-dimethylbenzamide 167 ± 16 Phenylmethylsulfoxide 141 ± 4 4-Methoxypyridine 139 ± 2 4-Methylpyridine 107 ± 2 N, N-Dimethylcyclohexylamine 118 ± 2 N, N-dimethylformamide 115 ± 2 diphenylsulfoxide 106 ± 2 flavone 98 ± 6 N, N-dimethyl-n-propylamine 95 ± 1 trimethylamine 85 ± 2 2-n-bu Rupirijin 76 ± 2 pyridine 76 ± 1 quinoline 71 ± 3 tri -n- butylamine 37 ± 3 N, N- dimethylbenzylamine 38 ± 3 pyrimidin 22.5 ± 0.5

Next, the compound of the formula (II) will be described in detail. In the general formula (II), R ²¹ and R ²² each independently represent an alkyl group. R ²³ represents an alkyl group, an aryl group or a heterocyclic group. These groups may be unsubstituted or substituted with a substituent. The substituent groups include the substituent groups in R ⁵¹ to be described later. Specific examples of R ²¹ and R ²² include a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a t-butyl group, a t-amyl group, a cyclohexyl group, a 1-methylcyclohexyl group, and a benzyl group. For example, the aryl group includes a phenyl group, a p-toluril group, and a p-methoxyphenyl group, and the heterocyclic group includes a 2-tetrahydrofuranyl group and a 4-pyridyl group. These substituents may be unsubstituted or may be substituted with another group. However, the alkyl group here does not include an alkenyl group or an alkynyl group. Two or more selected from R ²¹ , R ²² and R ²³ may be connected to each other to form a ring.

The compound of the formula (III) will be described in detail. In the general formula (III), R ³¹ and R ³² each independently represent an alkyl group, an aryl group or a heterocyclic group. These groups may be unsubstituted or substituted with a substituent. The substituent groups include the substituent groups in R ⁵¹ to be described later. R ³¹ and R ³² are specifically an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a t-butyl group, a t-amyl group, a cyclohexyl group, a 1-methylcyclohexyl group, and a benzyl group. For example, an aryl group includes a phenyl group, a p-toluril group, and a p-methoxyphenyl group, and a heterocyclic group includes a 2-tetrahydrofuranyl group and a 4-pyridyl group. These substituents may be unsubstituted or may be substituted with another group. R ³¹ and R ³² may be linked to each other to form a ring.

The compound of the general formula (IV) is explained in detail.
I will tell. In the general formula (IV), R⁴¹And R⁴²Each
And each independently represents an alkyl group, an aryl group or a heterocyclic group.
R⁴³Is an alkyl group, an aryl group, a heterocyclic group or -N (R
⁴⁴) (R⁴⁵) And R⁴⁴And R⁴⁵Are independent
Represents an alkyl group, an aryl group, or a heterocyclic group. These groups are
It may be unsubstituted or substituted with a substituent. As a substituent
R⁵¹And the substituent in
You. R⁴¹, R⁴², R ⁴³Specifically, the alkyl group is methyl
, Ethyl, propyl, butyl, isopropyl
Group, t-butyl group, t-amyl group, cyclohexyl group,
Aryls such as 1-methylcyclohexyl and benzyl
Phenyl group, p-tolylyl group, p-methoxyphenyl
A heterocyclic group such as a nyl group is a 2-tetrahydrofuranyl group,
A 4-pyridyl group. These substituents are unsubstituted
Or it may be substituted with another group. R⁴¹, R
⁴², R⁴³, R⁴⁴And R⁴⁵2 or more selected from
And may be connected to each other to form a ring.

The compound represented by formula (V) will be described in detail. In the general formula (V), R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴
And R ⁵⁵ each independently represent a hydrogen atom or a substituent. As the substituent, a linear or branched, chain or cyclic alkyl group, a linear or branched, chain or cyclic alkenyl group, alkynyl group, aryl group, acyloxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group , A carbamoyloxy group, a carbonamide group, a sulfonamide group, a carbamoyl group, a sulfamoyl group, an alkoxy group, an aryloxy group, an aryloxycarbonyl group, an alkoxycarbonyl group, an N-acylsulfamoyl group, an N-sulfamoylcarbamoyl group An alkylsulfonyl group, an arylsulfonyl group,
Alkoxycarbonylamino group, aryloxycarbonylamino group, amino group, ammonium group, cyano group, nitro group, carboxyl group, hydroxy group, sulfo group, mercapto group, alkylsulfinyl group, arylsulfinyl group, alkylthio group, arylthio group, ureido Group, heterocyclic group (for example, a monocyclic or condensed 3- to 12-membered ring containing at least one or more of nitrogen, oxygen and sulfur), a heterocyclic oxy group, a heterocyclic thio group, an acyl group, and a sulfamoyl Examples include an amino group, a silyl group and a halogen atom.

Specifically, a hydrogen atom, a linear or branched, chain or cyclic alkyl group having 1 to 10 carbon atoms (for example, trifluoromethyl, methyl, ethyl, propyl,
Heptafluoropropyl, isopropyl, butyl, t-
Butyl, t-pentyl, cyclopentyl, cyclohexyl, octyl, 2-ethylhexyl, etc.), having 2 to 1 carbon atoms
0 linear or branched, chain or cyclic alkenyl groups (eg, vinyl, 1-methylvinyl, cyclohexene-
1-yl, etc.), an alkynyl group having 2 to 10 carbon atoms (eg, ethynyl, 1-propynyl, etc.), an aryl group having 6 to 14 carbon atoms (eg, phenyl, naphthyl, etc.), an acyloxy group having 1 to 10 carbon atoms (For example, acetoxy, benzoyloxy and the like), an alkoxycarbonyloxy group having 2 to 10 carbon atoms (for example, methoxycarbonyloxy group,
2-methoxyethoxycarbonyloxy group), an aryloxycarbonyloxy group having 7 to 14 carbon atoms (for example, a phenoxycarbonyloxy group) and 1 to 12 carbon atoms
A carbamoyloxy group (e.g., N, N-dimethylcarbamoyloxy, etc.), a carbonamide group having 1 to 12 carbon atoms (e.g., formamide, N-methylacetamide, acetamide, N-methylformamide, benzamide, etc.), carbon number 1 to 10 sulfonamide groups (for example, methanesulfonamide, benzenesulfonamide,
a carbamoyl group having 1 to 10 carbon atoms (eg, N-methylcarbamoyl, N,
N-diethylcarbamoyl, N-mesylcarbamoyl, etc.), a sulfamoyl group having 0 to 10 carbon atoms (for example, N
-Butylsulfamoyl, N, N-diethylsulfamoyl, N-methyl-N- (4-methoxyphenyl) sulfamoyl and the like, an alkoxy group having 1 to 10 carbon atoms (for example, methoxy, propoxy, isopropoxy, octyl) Oxy, t-octyloxy, etc.), an aryloxy group having 6 to 14 carbon atoms (eg, phenoxy, 4-methoxyphenoxy, naphthoxy, etc.), an aryloxycarbonyl group having 7 to 14 carbon atoms (eg, phenoxycarbonyl,
Naphthoxycarbonyl), an alkoxycarbonyl group having 2 to 10 carbon atoms (eg, methoxycarbonyl, t-butoxycarbonyl, etc.), an N-acylsulfamoyl group having 1 to 12 carbon atoms (eg, N-ethylsulfamoyl) ,
N-benzoylsulfamoyl, etc.), N-sulfamoylcarbamoyl group having 1 to 12 carbon atoms (eg, N-methanesulfonylcarbamoyl group), alkylsulfonyl group having 1 to 10 carbon atoms (eg, methanesulfonyl, octylsulfonyl) , 2-methoxyethylsulfonyl, etc.),
An arylsulfonyl group having 6 to 14 carbon atoms (for example, benzenesulfonyl, p-toluenesulfonyl, 4-phenylsulfonylphenylsulfonyl, etc.), a carbon number of 2 to 10
An alkoxycarbonylamino group (e.g., ethoxycarbonylamino and the like), an aryloxycarbonylamino group having 7 to 14 carbon atoms (e.g., phenoxycarbonylamino, naphthoxycarbonylamino and the like), and a carbon number of 0 to 1
0 amino group (for example, amino, methylamino, diethylamino, diisopropylamino, anilino, morpholino, etc.), an ammonio group having 3 to 12 carbon atoms (for example, trimethylammonio group, dimethylbenzylammonio group, etc.) cyano group, nitro group A carboxyl group, a hydroxy group, a sulfo group, a mercapto group, an alkylsulfinyl group having 1 to 10 carbon atoms (for example, methanesulfinyl, octanesulfinyl and the like), and an arylsulfinyl group having 6 to 14 carbon atoms (for example, benzenesulfinyl, 4- Chlorophenylsulfinyl, p-toluenesulfinyl, etc.), an alkylthio group having 1 to 10 carbon atoms (eg, methylthio, octylthio, cyclohexylthio, etc.), and an arylthio group having 6 to 14 carbon atoms (eg, phenylthio,
Naphthylthio, etc.), a ureido group having 1 to 13 carbon atoms (for example, 3-methylureido, 3,3-dimethylureido,
1,3-diphenylureido and the like, and a heterocyclic group having 2 to 15 carbon atoms (for example, a heterocyclic atom containing at least one or more of nitrogen, oxygen and sulfur, etc., is a 3- to 12-membered monocyclic or condensed ring. For example, 2-furyl, 2-pyranyl, 2
-Pyridyl, 2-thienyl, 2-imidazolyl, morpholino, 2-quinolyl, 2-benzimidazolyl, 2-benzothiazolyl, 2-benzoxazolyl, etc.), heterocyclic oxy group (for example, pyridyloxy, pyrazolyloxy, etc.), heterogeneous Ring thio groups (eg, tetrazolylthio, 1,
3,4-thiadiazolylthio, 1,3,4-oxadiazolylthio, benzimidazolylthio, etc.), having 1 to 1 carbon atoms
12 acyl groups (for example, acetyl, benzoyl, trifluoroacetyl and the like), a sulfamoylamino group having 0 to 10 carbon atoms (for example, N-butylsulfamoylamino, N-phenylsulfamoylamino and the like), carbon Number 3
To 12 silyl groups (eg, trimethylsilyl, dimethyl-t-butylsilyl, etc.) and halogen atoms (eg, fluorine atom, chlorine atom, bromine atom, etc.). The above-mentioned substituent may further have a substituent, and examples of the substituent include the substituents mentioned here.
Two or more selected from R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ and R ⁵⁵ may be connected to each other to form a ring.

The electron donating compound according to the present invention is described below.
Specific examples of the compounds represented by the general formulas (II), (III), (IV) and (V) are shown below, but the invention is not limited thereto.

[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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The "compound having a phosphoryl group" (hereinafter sometimes referred to as a phosphoryl compound) used in the present invention may be any compound as long as it has at least one phosphoryl group in a molecule. In particular, the general formula (V
Compounds represented by I) are preferred. In the general formula (VI), R ⁶¹ , R ⁶² and R ⁶³ each independently represent an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group. These groups may be unsubstituted or have a substituent.

Examples of the alkyl group include methyl, ethyl, butyl, octyl, dodecyl, isopropyl, t-butyl, t-amyl, t-octyl,
Examples include a cyclohexyl group and a 1-methylcyclohexyl group. Examples of the aryl group include a phenyl group, a cresyl group, a xylyl group, a naphthyl group, a 4-t-butylphenyl group, a 4-t-octylphenyl group, a 4-anisidyl group, and a 3,5-dichlorophenyl group. .
Examples of the aralkyl group include a benzyl group, a phenethyl group, a 2-phenoxypropyl group, and the like. Examples of the alkoxy group include methoxy, ethoxy, butoxy, octyloxy, 2-ethylhexyloxy, 3,5,5-trimethylhexyloxy, dodecyloxy, cyclohexyloxy, and 4-methylcyclohexyloxy Group, benzyloxy group and the like. Examples of aryloxy groups include phenoxy, cresyloxy, isopropylphenoxy, 4-t-
Examples thereof include a butylphenoxy group, a naphthoxy group, and a biphenyloxy group. Examples of the amino group include a dimethylamino group, a diethylamino group, a dibutylamino group, a dioctylamino group, an N-methyl-N-hexylamino group, a dicyclohexylamino group, a diphenylamino group, and an N-methyl-N-phenylamino group. .

As R ⁶¹ , R ⁶² and R ⁶³ , an alkyl group, an aryl group, an alkoxy group and an aryloxy group are preferred. More preferably, at least one or more of R ⁶¹ , R ⁶² and R ⁶³ is an alkyl group or an aryl group, and further preferably, two or more are an alkyl group or an aryl group. R ⁶¹ , R ⁶² and R ⁶³ are preferably the same group in that they can be obtained at low cost. When R ⁶¹ , R ⁶² and R ⁶³ have a substituent, examples of the substituent include a halogen atom, an alkyl group, an aryl group, an alkoxy group, an amino group, an acyl group, an acylamino group, an alkylthio group, an arylthio group, a sulfonamide group, Acyloxy group, oxycarbonyl group, carbamoyl group,
Examples include a sulfamoyl group, a sulfonyl group, and a phosphoryl group. The substituent is preferably a substituted or unsubstituted alkyl group, aryl group, alkoxy group or aryloxy group, such as methyl group, ethyl group, isopropyl group, t-butyl group, t-octyl group, phenyl group, 4- Examples include an alkoxyphenyl group, a 4-acyloxyphenyl group, a methoxy group, and a phenoxy group.
R ⁶³ is preferably a phenyl group, and more preferably a phenyl group having at least one ortho position substituted. The ortho-position substituent is described in more detail as follows: linear or branched, chain or cyclic alkyl group, linear or branched, chain or cyclic alkenyl group, alkynyl group, aryl group, acyloxy group, alkoxycarbonyloxy group An aryloxycarbonyloxy group, a carbamoyloxy group, a carbonamide group, a sulfonamide group, a carbamoyl group, a sulfamoyl group, an alkoxy group, an aryloxy group, an aryloxycarbonyl group, an alkoxycarbonyl group, an N-acylsulfamoyl group, N -A sulfamoylcarbamoyl group, an alkylsulfonyl group,
Arylsulfonyl group, alkoxycarbonylamino group, aryloxycarbonylamino group, amino group, ammonium group, cyano group, nitro group, carboxyl group, hydroxy group, sulfo group, mercapto group, alkylsulfinyl group, arylsulfinyl group, alkylthio group,
An arylthio group, a ureido group, a heterocyclic group (for example, containing at least one or more of nitrogen, oxygen and sulfur,
A monocyclic to 12-membered ring, a condensed ring), a heterocyclic oxy group, a heterocyclic thio group, an acyl group, a sulfamoylamino group, a silyl group, and a halogen atom.

Specifically, a hydrogen atom, a linear or branched, chain or cyclic alkyl group having 1 to 10 carbon atoms (for example, trifluoromethyl, methyl, ethyl, propyl,
Heptafluoropropyl, isopropyl, butyl, t-
Butyl, t-pentyl, cyclopentyl, cyclohexyl, octyl, 2-ethylhexyl, etc.), having 2 to 1 carbon atoms
0 linear or branched, chain or cyclic alkenyl groups (eg, vinyl, 1-methylvinyl, cyclohexene-
1-yl, etc.), an alkynyl group having 2 to 10 carbon atoms (eg, ethynyl, 1-propynyl, etc.), an aryl group having 6 to 14 carbon atoms (eg, phenyl, naphthyl, etc.), an acyloxy group having 1 to 10 carbon atoms (For example, acetoxy, benzoyloxy and the like), an alkoxycarbonyloxy group having 2 to 10 carbon atoms (for example, methoxycarbonyloxy group,
2-methoxyethoxycarbonyloxy group or the like), an aryloxycarbonyloxy group having 7 to 14 carbon atoms (for example, a phenoxycarbonyloxy group or the like),
A carbamoyloxy group (e.g., N, N-dimethylcarbamoyloxy), a carbonamide group having 1 to 12 carbon atoms (e.g., formamide, N-methylacetamide, acetamido, N-methylformamide, benzamide, etc.), carbon Number 1 to 10 sulfonamide groups (for example, methanesulfonamide, benzenesulfonamide,
a carbamoyl group having 1 to 10 carbon atoms (eg, N-methylcarbamoyl, N,
N-diethylcarbamoyl, N-mesylcarbamoyl, etc.), a sulfamoyl group having 0 to 10 carbon atoms (for example, N
-Butylsulfamoyl, N, N-diethylsulfamoyl, N-methyl-N- (4-methoxyphenyl) sulfamoyl and the like, an alkoxy group having 1 to 10 carbon atoms (for example, methoxy, propoxy, isopropoxy, octyl) Oxy, t-octyloxy, etc.), an aryloxy group having 6 to 14 carbon atoms (eg, phenoxy, 4-methoxyphenoxy, naphthoxy, etc.), an aryloxycarbonyl group having 7 to 14 carbon atoms (eg, phenoxycarbonyl,
Naphthoxycarbonyl), an alkoxycarbonyl group having 2 to 10 carbon atoms (eg, methoxycarbonyl, t-butoxycarbonyl, etc.), an N-acylsulfamoyl group having 1 to 12 carbon atoms (eg, N-ethylsulfamoyl) ,
N-benzoylsulfamoyl, etc.), an N-sulfamoylcarbamoyl group having 1 to 12 carbon atoms (eg, N-methanesulfonylcarbamoyl group), an alkylsulfonyl group having 1 to 10 carbon atoms (eg, methanesulfonyl, octyl) Sulfonyl, 2-methoxyethylsulfonyl, etc.), an arylsulfonyl group having 6 to 14 carbon atoms (for example, benzenesulfonyl, p-toluenesulfonyl,
-Phenylsulfonylphenylsulfonyl, etc.), an alkoxycarbonylamino group having 2 to 10 carbon atoms (eg, ethoxycarbonylamino), an aryloxycarbonylamino group having 7 to 14 carbon atoms (eg, phenoxycarbonylamino, naphthoxycarbonylamino, etc.) ), An amino group having 0 to 10 carbon atoms (eg, amino, methylamino, diethylamino, diisopropylamino, anilino, morpholino, etc.), an ammonio group having 3 to 12 carbon atoms (eg, trimethylammonio group, dimethylbenzylammonio group) Etc.) cyano group, nitro group, carboxyl group, hydroxy group, sulfo group, mercapto group, carbon number 1
To 10 alkylsulfinyl groups (e.g., methanesulfinyl, octanesulfinyl, etc.), having 6 to 14 carbon atoms
(E.g., benzenesulfinyl, 4-chlorophenylsulfinyl, p-toluenesulfinyl, etc.), an alkylthio group having 1 to 10 carbon atoms (e.g., methylthio, octylthio, cyclohexylthio, etc.), an arylthio group having 6 to 14 carbon atoms (For example,
Phenylthio, naphthylthio, etc.), a ureido group having 1 to 13 carbon atoms (eg, 3-methylureide, 3,3-dimethylureide, 1,3-diphenylureide, etc.), a heterocyclic group having 2 to 15 carbon atoms (heteroatom) Include, for example, at least one or more of nitrogen, oxygen, sulfur, and the like.
A 12-membered monocyclic or condensed ring such as 2-furyl, 2
-Pyranyl, 2-pyridyl, 2-thienyl, 2-imidazolyl, morpholino, 2-quinolyl, 2-benzimidazolyl, 2-benzothiazolyl, 2-benzoxazolyl and the like, a heterocyclic oxy group (for example, pyridyloxy, pyrazolyloxy) Heterocyclic thio group (for example, tetrazolylthio, 1,3,4-thiadiazolylthio, 1,3,
4-oxadiazolylthio, benzimidazolylthio, etc.), an acyl group having 1 to 12 carbon atoms (for example, acetyl,
Benzoyl, trifluoroacetyl, etc.), having 0 to 1 carbon atoms
0, a sulfamoylamino group (eg, N-butylsulfamoylamino, N-phenylsulfamoylamino, etc.), a silyl group having 3 to 12 carbon atoms (eg, trimethylsilyl, dimethyl-t-butylsilyl, etc.), halogen Atoms (for example, a fluorine atom, a chlorine atom, a bromine atom, etc.). These substituents may be present at positions other than the ortho position of the phenyl group of R ⁶³ . When R ⁶³ is a phenyl group having a substituent at the ortho position, R ⁶¹ and R ⁶² are preferably an alkyl group or an aryl group.

Specific examples of the compound having a phosphoryl group used in the present invention are shown below, but the present invention is not limited to these.

[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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[0048]

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[0049] The preferably amount of at least one condition is satisfied compounds A and B are each 0.01~4.0g / m ^2, more preferably from 0.1 to 2.0 g / m ^2, the image forming layer 2 to 1 mole of silver on the surface having
It is preferably contained in an amount of 40% by mole, and more preferably 5 to 30% by mole. The addition ratio (molar ratio) of the phenolic reducing agent (compound of the general formula (I)) and the compound satisfying at least one of the conditions A and B is preferably in the range of 0.1 to 10, more preferably in the range of 0.1 to 2.0. preferable. More preferably, it is in the range of 0.5 to 1.5. The phenolic compound (compound of the general formula (I)) and the compound satisfying at least one of the above conditions A and B are preferably contained in an image forming layer containing an organic silver salt. May be contained in the adjacent non-image forming layer, or both may be contained in the non-image forming layer. Further, when the image forming layer is composed of a plurality of layers, each of them can be contained in another layer.

The phenol compound (compound of the general formula (I)) and the compound satisfying at least one of the above conditions A and B can be contained in the coating solution by any method such as a solution form, an emulsified dispersion form and a solid fine particle dispersion form. May be contained in the photosensitive material. Well-known emulsification dispersion methods include oils such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and dissolution using an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically dispersing the emulsified dispersion. A method for producing the same is given. As a method for dispersing solid fine particles, a phenol compound (compound of the general formula (I)) and a powder of a compound satisfying at least one of the above conditions A and B are mixed in a suitable solvent such as water in a ball mill, a colloid mill, or the like. Vibration ball mills, sand mills, jet mills, roller mills, or a method of dispersing with an ultrasonic wave to prepare a solid dispersion can be used. In this case, a protective colloid (for example, polyvinyl alcohol) and a surfactant (for example, an anionic surfactant such as sodium triisopropylnaphthalenesulfonate (a mixture of three isopropyl groups having different substitution positions)) may be used. Good. The aqueous dispersion can contain a preservative (eg, benzoisothiazolinone sodium salt).

The organic silver salt which can be used in the present invention is
Relatively stable to light, but forms a silver image when heated to 80 ° C or higher in the presence of an exposed photocatalyst (such as a latent image of photosensitive silver halide) and a thermal developer Silver salt. The organic silver salt can be any organic substance including a source capable of reducing silver ions. Such non-photosensitive organic silver salts are described in JP-A-10-62899, paragraphs [0048] to [0049] and European Patent Publication EP0-EP0.
No. 803763A1, page 18, line 24 to first
Page 9, line 37, European Patent Publication EP0962812A
No. 1 publication. Silver salts of organic acids, in particular silver salts of long-chain aliphatic carboxylic acids (with 10 to 30, preferably 15 to 28 carbon atoms) are preferred. Preferred examples of the organic silver salt include:
Silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, mixtures thereof, and the like.

The shape of the organic silver salt that can be used in the present invention is not particularly limited, but a scaly organic silver salt is preferable in the present invention. In the present specification, the scaly organic silver salt is defined as follows. The organic acid silver salt is observed with an electron microscope, and the shape of the organic acid silver salt particles is approximated to a rectangular parallelepiped.
When c is set (c may be the same as b), x is calculated as follows using the shorter numerical values a and b. x = b / a x is obtained for about 200 particles in this manner,
Assuming that the average value x (average), x (average) ≧ 1.5
The one satisfying the above relationship is scaly. Preferably 30
≧ x (average) ≧ 1.5, more preferably 20 ≧ x (average) ≧ 2.0. By the way, the needle shape is 1 ≦ x (average) <
1.5. In the scaly particle, a can be regarded as the thickness of a tabular particle having a main plane with b and c as sides. The average of a is preferably 0.01 μm to 0.23 μm, more preferably 0.1 μm to 0.20 μm. The average of c / b is preferably 1 to 6, more preferably 1.05 to 4,
More preferably, 1.1 to 3, particularly preferably 1.1 to
2.

The particle size distribution of the organic silver salt is preferably monodispersed. Monodisperse and the minor axis, the standard deviation of the length of each major axis is 100% or less, preferably 100% or less, more preferably 80% or less, more preferably 50% of the value obtained by dividing the standard deviation of the length of each major axis by each minor axis. It is as follows. The shape of the organic silver salt can be measured from a transmission electron microscope image of the organic silver salt dispersion. Another way to measure monodispersity is
There is a method of calculating the standard deviation of the volume-weighted average diameter of an organic silver salt, and the percentage of the value divided by the volume-weighted average diameter (coefficient of variation)
Is preferably 100% or less, more preferably 80% or less, and still more preferably 50% or less. As a measuring method, for example, the particle size (volume weighted average diameter) obtained by irradiating a laser beam to an organic silver salt dispersed in a liquid and obtaining an autocorrelation function with respect to a time change of fluctuation of the scattered light is obtained. Can be.

Known methods can be applied to the production of the organic silver salt used in the present invention and the dispersion method thereof. For example, the above-mentioned JP-A-10-62899, European Patent Publication EP0803763A1, European Patent Publication EP09
No. 62812A1 can be referred to. In the present invention, it is possible to produce a photosensitive material by mixing the aqueous dispersion of the organic silver salt and the aqueous dispersion of the photosensitive silver salt, the mixing ratio of the organic silver salt and the photosensitive silver salt can be selected according to the purpose, The ratio of the photosensitive silver salt to the organic silver salt is preferably in the range of 1 to 30 mol%, more preferably 3 to 20 mol%, and particularly preferably 5 to 15 mol%. Mixing two or more aqueous dispersions of organic silver salts with two or more aqueous dispersions of photosensitive silver salts during mixing is a method preferably used for controlling photographic characteristics. Organic silver salts can be used in a desired amount, preferably 0.1-5 g / m ² as silver amount, more preferably from 1 to 3 g / m ^2.

The photosensitive silver halide used in the present invention is not particularly limited in the halogen composition, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, and silver iodochlorobromide can be used. . The distribution of the halogen composition in the grains may be uniform, the halogen composition may change stepwise, or may change continuously. Further, silver halide grains having a core / shell structure can be preferably used. The preferred structure is
It has a double- to five-fold structure, and more preferably a double- to four-fold structure core /
Shell particles can be used. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.

Methods for forming photosensitive silver halide are well known in the art, for example, Research Disclosure No. 17029, June 1978, and US Pat.
No. 58, but specifically, a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to gelatin or another polymer solution, Thereafter, a method of mixing with an organic silver salt is used. The grain size of the photosensitive silver halide is preferably small for the purpose of suppressing white turbidity after image formation, specifically 0.20 μm or less, more preferably 0.01 to 0.15 μm, and still more preferably 0.02 to 0.12 μm. Good. The grain size as used herein means that when the silver halide grains are cubic or octahedral so-called normal crystals, and when they are not normal crystals, for example, in the case of spherical grains, rod-like grains, etc., the volume of the silver halide grains is It refers to the diameter when considering equivalent spheres, and when the silver halide grains are tabular grains, it refers to the diameter when converted into a circular image having the same area as the projected area of the main surface.

The shape of the silver halide grains is cubic,
Octahedral, tabular particles, spherical particles, rod-like particles, potato-like particles and the like can be mentioned. In the present invention, cubic particles are particularly preferable. Grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grains is not particularly limited, but the ratio of the [100] plane, which has high spectral sensitization efficiency when a spectral sensitizing dye is adsorbed, is high. preferable. The ratio is preferably 50% or more, 6
5% or more is more preferable, and 80% or more is further preferable. The ratio of the Miller index [100] plane is determined by T. Tani; J. Imaging using the dependence of the adsorption of the sensitizing dye on the [111] and [100] planes.
Sci., 29, 165 (1985).

The photosensitive silver halide grains preferably contain a metal or metal complex of Group 8 to Group 10 of the periodic table (showing Groups 1 to 18). Eighth of the periodic table
Rhodium, rhenium, ruthenium, osmium, and iridium are preferred as the metals of Group 10 to Group 10 or the central metal of the metal complex. One kind of these metal complexes may be used, or two or more kinds of complexes of the same metal and different metals may be used in combination. The preferred content is in the range of 1 × 10 ^-9 mol to 1 × 10 ^-3 mol per mol of silver. These metal complexes are described in paragraph No. 00 of JP-A-11-65021.
18-0024.

In the present invention, among them, it is preferable to include an iridium compound in silver halide grains. Examples of the iridium compound include hexachloroiridium, hexaammineiridium, trioxalatoiridium, hexacyanoiridium, and pentachloronitrosyliridium. These iridium compounds are used after being dissolved in water or an appropriate solvent. However, a method generally used to stabilize the solution of the iridium compound, that is, an aqueous solution of hydrogen halide (for example, hydrochloric acid, hydrobromic acid, hydrofluoric acid) is used. Etc.) or a method of adding an alkali halide (eg, KCl, NaCl, KBr, NaBr, etc.). Instead of using water-soluble iridium, it is also possible to add and dissolve another silver halide grain doped with iridium in advance during the preparation of silver halide. The addition amount of these iridium compounds is 1 × 10 ⁻⁸ mol / mol of silver halide.
The range of 1 × 10 ^-3 mol is preferable, and 1 × 10 ^-7 mol to 5 mol
A range of × 10 ^-4 mol is more preferred.

Further, metal atoms (for example, [Fe (CN) ₆ ]) which can be contained in the silver halide grains used in the present invention.
^4- ), desalting and chemical sensitization are described in JP-A-11-84574, paragraphs 0046 to 0050, and JP-A-11-65021, paragraphs 0025 to 0031. In the photothermographic material of the present invention, a phenol derivative represented by the formula (A) described in Japanese Patent Application No. 11-73951 is preferably used as a development accelerator.

The sensitizing dye applicable to the present invention is a sensitizing dye capable of spectrally sensitizing silver halide grains in a desired wavelength region when adsorbed on the silver halide grains. The sensitizing dye to be used can be advantageously selected. For sensitizing dyes and addition methods, see
-65021, paragraphs 0103 to 0109, JP-A-10-186572
Compound represented by general formula (II), European Patent Publication EP08
No. 03764A1, page 19, line 38 to page 20, line 35. In the present invention, the time when the sensitizing dye is added to the silver halide emulsion is preferably after the desalting step and before coating, and more preferably after desalting and before the start of chemical ripening. The addition amount of the sensitizing dye in the present invention can be a desired amount in accordance with the sensitivity and the performance of fog, but is preferably 10 ^-6 to 1 mol per mol of silver halide in the photosensitive layer, and more preferably. Is 10 ^-4 to 10 ^-1 mol. In the present invention, a supersensitizer can be used to improve spectral sensitization efficiency. As the supersensitizer used in the present invention, European Patent Publication No. 58
7,338, U.S. Pat. Nos. 3,877,943 and 4,873,184, JP-A-5-3
No. 41432, Japanese Patent Application Laid-Open No. H11-109947,
Compounds described in JP-A-10-111543 are exemplified.

The photosensitive silver halide grains in the present invention are preferably chemically sensitized by a sulfur sensitization method, a selenium sensitization method, or a tellurium sensitization method. As the compound preferably used in the sulfur sensitization method, the selenium sensitization method, and the tellurium sensitization method, known compounds, for example, compounds described in JP-A-7-128768 can be used. In particular, tellurium sensitization is preferred in the present invention.Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides , Bis (carbamoyl) ditellurides, compounds having a P = Te bond, tellurocarboxylates, tellurosulfonates, compounds having a P-Te bond, tellurocarbonyl compounds, and the like. Specifically, JP-A-11-650
Compounds described in the literature described in paragraph No. 0030 of JP-A-21 can be exemplified. Particularly, compounds represented by formulas (II), (III) and (IV) in JP-A-5-313284 are preferred.

In the present invention, chemical sensitization can be performed at any time after grain formation and before coating, and after desalting, (1) before spectral sensitization, (2) simultaneously with spectral sensitization, ( 3) After spectral sensitization, (4) immediately before coating, and the like. In particular, it is preferably performed after spectral sensitization. The amount of the sulfur, selenium and tellurium sensitizers used in the present invention varies depending on the silver halide grains used, the conditions of chemical ripening, etc., but is preferably 10 ^-8 to 10 ^-2 mol, and more preferably 10 ^-8 to 10 ^-2 mol per mol of silver halide. 10 ^-7 ~
About 10 ^-3 mol is used. The conditions of the chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, p
Ag is 6-11, preferably 7-10, and the temperature is 40-95 ° C, preferably 44-70 ° C.

The light-sensitive silver halide emulsion in the light-sensitive material used in the present invention may be of one kind or two or more kinds (for example, those having different average grain sizes, different halogen compositions, different crystal habits). And those having different conditions of chemical sensitization). The gradation can be adjusted by using a plurality of photosensitive silver halides having different sensitivities.
Japanese Patent Application Laid-Open No. 57-119341 discloses techniques related to these.
No. 53-106125, No. 47-3929, No. 48-55730, No. 46-5187, No. 50-73627, No. 57-150841
And the like. It is preferable that each emulsion has a difference of 0.2 logE or more as a sensitivity difference.

[0065] The addition amount of the photosensitive silver halide, when expressed by the amount of coated silver per photosensitive material 1 m ^2, it is preferably 0.03~0.6g / m ^2, is 0.05 to 0.4 g / m ² more preferably, and most preferably from 0.1 to 0.4 g / m ^2, relative to the organic silver salt to 1 mole of the photosensitive silver halide 0.01 mol to
0.5 mol is preferable, 0.02 mol to 0.3 mol is more preferable, and 0.03 mol to 0.25 mol is particularly preferable. Regarding the mixing method and the mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the prepared silver halide particles and organic silver salt were mixed with a high-speed stirrer, ball mill, sand mill, colloid mill, vibration mill, homogenizer, etc. And the like, or a method of preparing an organic silver salt by mixing photosensitive silver halide prepared at any timing during the preparation of the organic silver salt. There is no particular limitation as long as it appears in.

The preferred timing of adding the silver halide to the coating solution for the image forming layer is from 180 minutes to immediately before coating, preferably from 60 minutes to 10 seconds before coating. There is no particular limitation as long as the effects of the invention are sufficiently exhibited. As a specific mixing method, a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is a desired time or N.Ha
There is a method using a static mixer or the like described in Chapter 8 of "Liquid Mixing Technology" (published by Nikkan Kogyo Shimbun, 1989) by Koji Takahashi, rnby, MFEdwards, AWNienow, translated by Koji Takahashi.

In the present invention, when the organic silver salt-containing layer is formed by applying a coating solution in which 30% by weight or more of the solvent is water and drying, the binder of the organic silver salt-containing layer is further added. Soluble or dispersible in aqueous solvents (aqueous solvents), especially
It is improved when a latex of a polymer having an equilibrium moisture content at 25 ° C. and a relative humidity of 60% is 2% by weight or less. The most preferred form is prepared so that the ionic conductivity is 2.5 mS / cm or less. As such a preparation method, a method of purifying using a separation functional membrane after polymer synthesis can be mentioned. 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. Note that the term “aqueous solvent” is used herein even in a system in which the polymer is not thermodynamically dissolved but exists in a so-called dispersed state.

The “equilibrium moisture content at 25 ° C. and 60% relative humidity” refers to the weight W1 of the polymer which is in a moisture-conditioning equilibrium in an atmosphere of 25 ° C. and 60% relative humidity, and the weight of the polymer which is completely dried at 25 ° C. It can be expressed as follows using W0. Equilibrium water content at 25 ° C and 60% relative humidity = [(W1-W0) / W0] x 100 (weight
%) For the definition and measurement method of the water content, for example, Polymer Engineering Course 14, Polymer Material Testing Method (edited by the Society of Polymer Science, Jinjinshokan) can be referred to. The equilibrium moisture content of the binder polymer at 25 ° C. and 60% relative humidity is preferably 2% by weight or less, more preferably 0.01% by weight to 1.5% by weight,
More preferably, the content is 0.02% by weight to 1% by weight.

In the present invention, a polymer dispersible in an aqueous solvent is particularly preferred. Examples of the dispersion state include a latex in which fine particles of a solid polymer are dispersed, and a dispersion in which polymer molecules are dispersed in a molecular state or in the form of micelles, all of which are preferable. In a preferred embodiment of the present invention, acrylic resin, polyester resin,
A hydrophobic polymer such as a rubber-based resin (for example, SBR resin), a polyurethane resin, a vinyl chloride resin, a vinyl acetate resin, a vinylidene chloride resin, and a polyolefin resin can be preferably used. The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. The polymer has a number average molecular weight of 5000 to 100000, preferably 10,000 to 200,000. If the molecular weight is too small, the mechanical strength of the image forming layer (emulsion layer) is insufficient, and if it is too large, the film-forming properties are poor, which is not preferable. The “aqueous solvent” refers to a dispersion medium in which 30% by weight or more of the composition is water. The dispersion state may be any state such as emulsified dispersion, micelle dispersed, and further dispersed in a molecular state a polymer having a hydrophilic site in the molecule, but among these, latex is particularly preferred. .

Specific examples of preferable polymer latex include the following. In the following, the raw material monomers are used, and the numerical value in parentheses is% by weight, and the molecular weight is the number average molecular weight. P-1; -MMA (70) -EA (27) -MAA (3)-latex (molecular weight 3700
0) Latex of P-2; -MMA (70) -2EHA (20) -St (5) -AA (5)-(molecular weight 40000) P-3; -St (50) -Bu (47) -MAA ( 3)-latex (molecular weight 4500
0) P-4; -St (68) -Bu (29) -AA (3)-latex (MW 60000) P-5; -St (70) -Bu (27) -IA (3)-latex (Molecular weight 12000
0) Latex of P-6; -St (75) -Bu (24) -AA (1)-(molecular weight 10800
0) P-7; -St (60) -Bu (35) -DVB (3) -MAA (2)-latex (molecular weight 150,000) P-8; -St (70) -Bu (25) -DVB ( 2) -AA (3)-latex (molecular weight 280000) P-9; -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-latex (molecular weight 80000) P-10; -VDC (85) -MMA (5) -EA (5) -MAA (5)-latex (molecular weight 67,000) P-11; -Et (90) -MAA (10)-latex (molecular weight) 12000) P-12; -St (70) -2EHA (27) -AA (3) latex (molecular weight 130
000) P-13; -MMA (63) -EA (35) -AA (2) latex (molecular weight 3300
0)

The abbreviations of the above structures represent the following monomers.
MMA; methyl methacrylate, EA; ethyl acrylate, MAA; methacrylic acid, 2EHA; 2-ethylhexyl acrylate, St; styrene, Bu; butadiene, AA; acrylic acid, DVB; divinylbenzene, VC; vinyl chloride, AN; Vinylidene chloride, Et; ethylene, IA; itaconic acid.

The polymer latexes described above are also commercially available, and the following polymers can be used. Examples of acrylic resins include Sebian A-4635, 46683, and 460.
1 (manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 82
Examples of polyester resins such as 1,820,857 (all manufactured by Zeon Corporation) include FINETEX ES650, 611, 675, 850
HYDRAN AP10, 20, 30, and 40 (Dai Nippon Ink Chemical Co., Ltd.) For example, LACSTAR 731
0K, 3307B, 4700H, 7132C (Dai Nippon Ink Chemical Co., Ltd.
Nipol Lx416, 410, 438C, 2507 (Nippon Zeon Co., Ltd.)
Examples of vinyl chloride resins include G351 and G576 (all manufactured by Nippon Zeon Co., Ltd.), and examples of vinylidene chloride resins include L502 and L513 (all manufactured by Asahi Kasei Corporation). Examples thereof include Chemipearl S120 and SA100 (all manufactured by Mitsui Petrochemical Co., Ltd.). These polymer latexes may be used alone, or may be used in combination of two or more as needed.

The polymer latex used in the present invention is particularly preferably a styrene-butadiene copolymer latex. The weight ratio of the styrene monomer unit to the butadiene monomer unit in the styrene-butadiene copolymer is preferably from 40:60 to 95: 5. Also,
The proportion of the styrene monomer unit and the butadiene monomer unit in the copolymer is preferably 60 to 99% by weight. The preferred molecular weight range is the same as described above. Examples of the styrene-butadiene copolymer latex that is preferably used in the present invention include the above-mentioned P-3 to P-8 and commercially available products such as LACSTAR-3307B, 7132C, and Nipol Lx416.

The organic silver salt-containing layer of the photothermographic material of the present invention may optionally contain a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose and the like. The amount of these hydrophilic polymers added is 30% by weight of the total binder in the organic silver salt-containing layer.
% Or less, more preferably 20% by weight or less.

The organic silver salt-containing layer (that is, the image forming layer)
Those formed using a polymer latex are preferred. The amount of the binder in the organic silver salt-containing layer depends on the total amount of the binder.
The weight ratio of the organic silver salt is preferably in the range of 1/1 to 10/1, more preferably 1/5 to 4/1. Further, such an organic silver salt-containing layer is usually a photosensitive layer (emulsion layer) containing a photosensitive silver halide, which is a photosensitive silver salt. The weight ratio of silver is preferably in the range of 400-5, more preferably 200-10. The total amount of the binder in the image forming layer is preferably from 0.2 to 30 g / m ² , more preferably from 1 to 15 g / m ² . A crosslinking agent for crosslinking and a surfactant for improving coating properties may be added to the image forming layer.

In the present invention, the solvent of the coating solution for the organic silver salt-containing layer of the light-sensitive material (the solvent and the dispersion medium are collectively referred to as a solvent for simplicity) is an aqueous solvent containing 30% by weight or more of water. As a component other than water, any water-miscible organic solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate may be used. The water content of the solvent in the coating liquid is preferably 50% by weight or more, more preferably 70% by weight or more. Examples of preferred solvent composition include water, water / methyl alcohol = 90/10, water / methyl alcohol = 70/30, water / methyl alcohol / dimethylformamide = 80/15/5, water / methyl alcohol / Ethyl cellosolve = 85/10/5, water / methyl alcohol / isopropyl alcohol = 85/10/5, etc. (numerical values are% by weight).

Antifoggants, stabilizers and stabilizer precursors which can be used in the present invention Paragraph 0070 of JP-A-10-62899, page 20, line 57 to page 21 of EP0803764A1 The patents listed in line 7 are mentioned. The antifoggant preferably used in the present invention is an organic halide, and these are described in paragraphs 0111 to 0112 of JP-A-11-65021.
And those disclosed in the patents described in US Pat. In particular, organic polyhalogen compounds represented by the general formula (II) in JP-A-10-339934 (specifically, tribromomethylnaphthyl sulfone, tribromomethylphenylsulfone, tribromomethyl (4- (2,4, 6-trimethylphenylsulfonyl) phenyl) sulfone and the like are preferred.

Examples of the method for incorporating the antifoggant into the light-sensitive material include the methods described in the above-mentioned method for containing the thermal developer. The organic polyhalogen compound is preferably added in the form of a solid fine particle dispersion. As other antifoggants, JP-A-11-65021, paragraph number 0113, mercury (I
I) Salts, benzoic acids of paragraph No. 0114 of the same publication, Japanese Patent Application No. 11
-87297, a salicylic acid derivative represented by the formula (Z), and a formalin scavenger compound represented by the formula (S) of Japanese Patent Application No. 11-23995.

The photothermographic material of the present invention may contain an azolium salt for the purpose of preventing fog. As the azolium salt, the general formula described in JP-A-59-193447
Compounds represented by (XI), compounds described in JP-B-55-12581, and compounds represented by formula (II) described in JP-A-60-153039 are exemplified. The azolium salt may be added to any part of the light-sensitive material. However, it is preferable to add the azolium salt to the layer having the photosensitive layer, and it is more preferable to add the azolium salt to the organic silver salt-containing layer. The azolium salt may be added at any time during the preparation of the coating solution, and when the azolium salt is added to the organic silver salt-containing layer, any process from the preparation of the organic silver salt to the preparation of the coating solution may be performed. To just before application. The azolium salt may be added by any method such as powder, solution, and fine particle dispersion. Further, it may be added as a solution mixed with other additives such as a sensitizing dye, a heat developer and a color tone agent. In the present invention, the addition amount of the azolium salt may be any amount, but is preferably 1 × 10 ⁻⁶ mol to 2 mol, more preferably 1 × 10 ⁻³ mol to 0.5 mol per mol of silver.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained in order to control development by suppressing or accelerating development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. Paragraph Nos.0067-006 of JP-A-10-62899 can be
9, described in paragraphs 0033 to 0052 of the compound represented by the general formula (I) of JP-A-10-186572 and specific examples thereof, page 20, lines 36 to 56 of EP0803764A1. I have. Among them, mercapto-substituted heteroaromatic compounds are preferred.

In the present invention, it is preferable to add a toning agent. For the toning agent, see paragraph 005 of JP-A-10-62899.
4-0055, EP-A-0 080 364 A1, page 21, lines 23 to 48, particularly phthalazinone, phthalazinone derivatives or metal salts, or 4- (1-naphthyl) phthalazinone, 6-chlorophenyl Tarazinone, 5,7-dimethoxyphthalazinone and 2,3-dihydro-
Derivatives such as 1,4-phthalazinedione; phthalazinone and phthalic acid derivatives (for example, phthalic acid, 4-methylphthalic acid,
-Nitrophthalic acid and tetrachlorophthalic anhydride etc.)
And phthalazines (phthalazine, phthalazine derivative or metal salt, or 4- (1-naphthyl) phthalazine, 6-isopropylphthalazine, 6-t-butylfuratazine, 6-chlorophthalazine, 5,7-dimethoxy Derivatives such as phthalazine and 2,3-dihydrophthalazine); combinations of phthalazines and phthalic acid derivatives (e.g., phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride) are preferred, Particularly, a combination of phthalazines and a phthalic acid derivative is preferable.

The plasticizers and lubricants that can be used in the photosensitive layer are described in JP-A-11-65021, paragraph 011.
7. With respect to the super-high contrast agent for forming a super-high contrast image, compounds of the general formulas (III) to (V) described in paragraph No. 0118 of the same publication and Japanese Patent Application No. 11-91652 (specific compounds: 21 ~ 2
4) The contrast enhancement accelerator is described in paragraph No. 0102 of JP-A-11-65021. The super-high contrast agents used in the present invention include the following general formulas (VII) and (VII)
It is preferably selected from the group consisting of substituted alkene derivatives, substituted isoxazole derivatives, and acetal compounds represented by I) and (IX), respectively.

[0083]

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The compound represented by formula (VII) will be described below in detail. In the general formula (VII),
R ⁷¹ , R ⁷² and R ⁷³ each independently represent a hydrogen atom or a substituent. When R ⁷¹ , R ⁷² and R ⁷³ represent a substituent, examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom or an iodine atom), an alkyl group (a cycloalkyl group, an active methine group) Etc.),
An aralkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group (including an N-substituted nitrogen-containing heterocyclic group), a heterocyclic group containing a quaternized nitrogen atom (for example, a pyridinio group), an acyl group, An alkoxycarbonyl group,
Aryloxycarbonyl group, carbamoyl group, carboxyl group or salt thereof, imino group, imino group substituted with N atom, thiocarbonyl group, sulfonylcarbamoyl group, acylcarbamoyl group, sulfamoylcarbamoyl group, carbazoyl group, oxalyl group, oxamoyl A group, a cyano group, a thiocarbamoyl group, a hydroxyl group or a salt thereof, an alkoxyl group (including a group repeatedly containing an ethyleneoxy group or a propyleneoxy group unit),
Aryloxy group, heterocyclic oxy group, acyloxy group, (alkoxy or aryloxy) carbonyloxy group, carbamoyloxy group, sulfonyloxy group,
An amino group, an (alkyl, aryl, or heterocycle) amino group, an acylamino group, a sulfonamide group, a ureido group, a thioureido group, an imide group, an (alkoxy or aryloxy) carbonylamino group, a sulfamoylamino group, a semicarbazide group, Thiosemicarbazide group, hydrazino group, quaternary ammonio group, oxamoylamino group, (alkyl or aryl) sulfonylureido group, acylureido group, acylsulfamoylamino group, nitro group, mercapto group, (alkyl, aryl,
Or heterocycle) thio group, acylthio group, (alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, sulfo group or a salt thereof, sulfamoyl group, acylsulfamoyl group, sulfonylsulfamoyl group or a salt thereof, Examples thereof include a phosphoryl group, a group containing a phosphoric acid amide or a phosphoric ester structure, a silyl group, and a stannyl group. These substituents may be further substituted with these substituents.

Among the substituents represented by R ⁷¹ , R ⁷² and R ⁷³ , groups having a total carbon number of 0 to 30 are preferred. Specifically, a group having the same meaning as the electron-withdrawing group represented by Z in the general formula (VII) described later, an alkyl group, a hydroxyl group or a salt thereof, a mercapto group or a salt thereof, an alkoxyl group, an aryloxy group, Heterocyclic oxy group, alkylthio group, arylthio group, heterocyclic thio group, amino group, alkylamino group, arylamino group, heterocyclic amino group, ureido group, acylamino group, sulfonamide group, substituted or unsubstituted aryl group, etc. Is preferred. R ⁷¹ is preferably a hydrogen atom, an electron-withdrawing group, an aryl group, an alkylthio group, an alkoxyl group, an acylamino group, or a silyl group. More preferably, it is an electron-withdrawing group or an aryl group.

[0086] When R ⁷¹ represents an electron-withdrawing group, R ⁷¹ is preferably a total following group having a carbon number of 0 to 30, i.e., a cyano group, a nitro group, an acyl group, a formyl group, an alkoxycarbonyl group, Aryloxycarbonyl group, thiocarbonyl group, imino group, imino group substituted with an N atom, alkylsulfonyl group, arylsulfonyl group, carbamoyl group, sulfamoyl group, trifluoromethyl group, phosphoryl group, carboxyl group or a salt thereof, or saturated Or an unsaturated heterocyclic group, more preferably a cyano group, an acyl group, a formyl group, an alkoxycarbonyl group, a carbamoyl group, an imino group, an imino group substituted with an N atom, a sulfamoyl group, a carboxyl group or a salt thereof, Or a saturated or unsaturated heterocyclic group. Particularly preferred are a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, and a saturated or unsaturated heterocyclic group.

R⁷¹Represents an aryl group;⁷¹Is preferred
A substituted or unsubstituted phenyl group having 6 to 30 carbon atoms
Group, and the substituent includes any substituent
However, among them, an electron-withdrawing substituent is preferable. General formula (V
In II), R⁷²And R⁷³Represents a substituent, R
⁷²And R ⁷³Is preferably a group represented by the following general formula (VII):
A group having the same meaning as the electron-withdrawing group represented by Z, an alkyl group,
Droxyl group (or salt thereof), mercapto group or
Salt, alkoxyl group, aryloxy group, heterocyclic
Xy, alkylthio, arylthio, heterocyclic
O group, amino group, alkylamino group, anilino group, hete
Ring amino group, acylamino group, substituted or unsubstituted
And phenyl. R⁷²And R⁷³Is more preferable
Is one of a hydrogen atom and the other is a substituent.
As the substituent, preferably, an alkyl group, a hydroxy
A sil group or a salt thereof, a mercapto group or a salt thereof,
Coxyl group, aryloxy group, heterocyclic oxy group,
Alkylthio group, arylthio group, heterocyclic thio group,
Group, alkylamino group, anilino group, heterocyclic amino
Group, acylamino group (especially perfluoroalkaneamide
Group), sulfonamide group, substituted or unsubstituted phenyl
Or a heterocyclic group, more preferably
Roxyl group or a salt thereof, mercapto group or a salt thereof,
Alkoxyl group, aryloxy group, heterocyclic oxy
Group, alkylthio group, arylthio group, heterocyclic thio
Or a heterocyclic group, more preferably a hydrocyclic group.
Xyl group or salt thereof, alkoxyl group, or hetero
It is a ring group.

In the general formula (VII), Z represents an electron-withdrawing group or a silyl group. Preferably, Z is an electron withdrawing group. The electron-withdrawing group represented by Z is a substituent whose Hammett's substituent constant σ _p can take a positive value, specifically, a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, Imino group, imino group substituted with an N atom, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, halogen atom, perfluoroalkyl group, perfluoroalkaneamide group, sulfonamide group, acyl group, Formyl group, phosphoryl group, carboxyl group or salt thereof, sulfo group or salt thereof, heterocyclic group, alkenyl group, alkynyl group, acyloxy group, acylthio group, sulfonyloxy group, or aryl substituted with these electron-withdrawing groups And the like. The heterocyclic group is a saturated or unsaturated heterocyclic group, for example, a pyridyl group, a quinolyl group, a quinoxalinyl group, a pyrazinyl group, a benzotriazolyl group, an imidazolyl group, a benzimidazolyl group, a hydantoin-1-yl group, a succinimide And phthalimide groups.

The electron-withdrawing group represented by Z may further have a substituent, and the substituent may be a substituent represented by R ⁷¹ , R ⁷² or R ^{73 in} the general formula (VII). Is mentioned. When Z represents an electron-withdrawing group, Z is preferably a group having a total number of carbon atoms of 0 to 30, that is, a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a thiocarbonyl group, an imino group. , An imino group substituted with an N atom, a sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a nitro group, a perfluoroalkyl group, an acyl group, a formyl group, a phosphoryl group, an acyloxy group, an acylthio group, or any electron withdrawing property Group, and more preferably a cyano group, an alkoxycarbonyl group, a carbamoyl group, an imino group, a sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, an acyl group, a formyl group, a phosphoryl group, and trifluoro group. Phenyl substituted with a methyl group or any electron withdrawing group Is equal, more preferably a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group, an imino group or a carbamoyl group. When Z represents a silyl group, Z is preferably a trimethylsilyl group, a t-butyldimethylsilyl group, a phenyldimethylsilyl group, a triethylsilyl group, a triisopropylsilyl group, a trimethylsilyldimethylsilyl group, or the like. In the general formula (VII), R ⁷¹ and Z, R ⁷² and R ⁷³ , R ⁷¹ and R ⁷² , and R ⁷³ and Z may be mutually bonded to form a cyclic structure. Among them, it is preferable that R ⁷¹ and Z or R ⁷² and R ⁷³ form a cyclic structure.
The cyclic structure formed is a non-aromatic carbon ring or a non-aromatic hetero ring. Preferably, the cyclic structure is a 5- to 7-membered ring having a total carbon number including a substituent of 1 to 40, more preferably 3 to 30.

Among the compounds represented by formula (VII), Z is preferably a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group, an imino group or a carbamoyl group, and R ⁷¹ is an electron withdrawing group. R ⁷² or R ⁷³ represents a hydrogen atom,
The other is a compound representing a hydroxyl group or a salt thereof, a mercapto group or a salt thereof, an alkoxyl group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, or a heterocyclic group. More preferred among the compounds represented by the general formula (VII), Z and R ^{71 form a} non-aromatic 5- to 7-membered cyclic structure, and one of R ⁷² and R ⁷³ is A hydrogen atom,
The other is a compound representing a hydroxyl group or a salt thereof, a mercapto group or a salt thereof, an alkoxyl group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, or a heterocyclic group. At this time, Z which forms a non-aromatic cyclic structure together with R ⁷¹ includes an acyl group, a carbamoyl group, an oxycarbonyl group,
A thiocarbonyl group, a sulfonyl group and the like are preferable.
^{As 71} , an acyl group, a carbamoyl group, an oxycarbonyl group, a thiocarbonyl group, a sulfonyl group, an imino group,
An imino group, an acylamino group, a carbonylthio group and the like substituted with an N atom are preferred.

Next, a compound represented by the general formula (VIII)
Will be described. In the general formula (VIII), R⁸¹
Is a substituent represented by R in the general formula (VII)⁷¹~ R⁷³of
Same as the substituent. Preferably, R⁸¹Is an electron-withdrawing group
Or an aryl group. R⁸¹Represents an electron-withdrawing group
Hour, R⁸¹Is preferably a group having 0 to 30 carbon atoms or less,
That is, cyano group, nitro group, acyl group, formyl group,
Alkoxycarbonyl group, aryloxycarbonyl group,
Alkylsulfonyl group, arylsulfonyl group, carba
Moyl group, sulfamoyl group, trifluoromethyl group,
Phosphoryl, imino, or saturated or unsaturated
A heterocyclic group, more preferably a cyano group, an acyl
Group, formyl group, alkoxycarbonyl group, carbamoy
Group, sulfamoyl group, alkylsulfonyl group, ant
Or a heterocyclic group, more preferably
Is a cyano group, formyl group, acyl group, alkoxy
It is a bonyl group, a carbamoyl group, or a heterocyclic group.
R⁸¹Represents an aryl group;⁸¹Is preferably total carbon
A substituted or unsubstituted phenyl group of numbers 0 to 30,
As the substituent, R represented by the general formula (VII)⁷¹, R ⁷²and
R⁷³And the substituent represented by R⁸¹Is particularly preferred
Is cyano group, alkoxycarbonyl group, carbamoyl
Group, heterocyclic group, or substituted or unsubstituted phenyl
Group, most preferably a cyano group, a heterocyclic group, or
Is an alkoxycarbonyl group.

Next, the compound represented by formula (IX) will be described. In the general formula (IX), X and Y
Represents a hydrogen atom or a substituent each independently. Alternatively, X and Y may be bonded to each other to form a cyclic structure, and the substituent represented by X or Y is represented by the general formula (VI
The substituents represented by R ⁷¹ , R ⁷² and R ^{73 in} I) are mentioned. Specifically, alkyl groups (including perfluoroalkyl groups, trichloromethyl groups, etc.), aryl groups, heterocyclic groups, halogen atoms, cyano groups, nitro groups, alkenyl groups, alkynyl groups, acyl groups, formyl groups, alkoxy groups Carbonyl group, aryloxycarbonyl group, imino group, imino group substituted with an N atom, carbamoyl group, thiocarbonyl group, acyloxy group, acylthio group, acylamino group, alkylsulfonyl group, arylsulfonyl group, sulfamoyl group, phosphoryl group, carboxyl Group or its salt, sulfo group or its salt, hydroxyl group or its salt, mercapto group or its salt, alkoxyl group, aryloxy group, heterocyclic oxy group, alkylthio group, arylthio group, heterocyclic thio group, amino group,
Examples thereof include an alkylamino group, an anilino group, a heterocyclic amino group, and a silyl group. These groups may further have a substituent. Alternatively, X and Y may combine with each other to form a cyclic structure, and the formed cyclic structure may be a non-aromatic carbon ring or a non-aromatic hetero ring.

The substituents represented by X and Y preferably have a total carbon number of 1 to 40, more preferably a total carbon number of 1 to 40.
~ 30. Specifically, a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an imino group, an imino group substituted with an N atom, a thiocarbonyl group, a sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a nitro group, Examples include a fluoroalkyl group, an acyl group, a formyl group, a phosphoryl group, an acylamino group, an acyloxy group, an acylthio group, a heterocyclic group, an alkylthio group, an alkoxyl group, and an aryl group. X and Y are more preferably a cyano group, a nitro group, an alkoxycarbonyl group, a carbamoyl group, an acyl group, a formyl group, an acylthio group, an acylamino group,
A thiocarbonyl group, a sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, an imino group, an imino group substituted with an N atom, a phosphoryl group, a trifluoromethyl group, a heterocyclic group, or a substituted phenyl group, and particularly preferred. Is a cyano group, an alkoxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, an acyl group, an acylthio group, an acylamino group, a thiocarbonyl group, a formyl group, an imino group, an imino group substituted with an N atom, a heterocyclic group Or a phenyl group substituted with an arbitrary electron-withdrawing group.

It is also preferred that X and Y combine with each other to form a non-aromatic carbon ring or a non-aromatic hetero ring. The formed ring structure is preferably a 5- to 7-membered ring, and has a total carbon number of 1 to 40 including substituents, and more preferably 3 to 7 members.
30 is preferred. X and Y forming a cyclic structure include an acyl group, a carbamoyl group, an oxycarbonyl group,
Preferred are a thiocarbonyl group, a sulfonyl group, an imino group, an imino group substituted with an N atom, an acylamino group, a carbonylthio group and the like. In the general formula (IX), A and B each independently represent an alkoxyl group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group,
Represents an anilino group, a heterocyclic oxy group, a heterocyclic thio group or a heterocyclic amino group. Alternatively, A and B may combine with each other to form a cyclic structure. The groups represented by A and B preferably have a total carbon number of 1 to 40, more preferably a total carbon number of 1 to 30, and may further have a substituent. A and B more preferably combine with each other to form a cyclic structure. The formed cyclic structure is preferably a 5- to 7-membered non-aromatic heterocycle, preferably having a total carbon number of 1 to 40, more preferably 3 to 40.
~ 30. Example in which A and B are bonded to each other (-AB
-) _{The, -O- (CH 2) 2 -O} -, - O- (CH
_{2) 3 -O -, - S-} (CH 2) 2 -S -, - S- (C
H ₂ ) ₃ -S-, -S-Ph-S-, -N (CH ₃ )-
_{(CH 2) 2 -O -,} - N (CH 3) - (CH 2) 2 -S
_{-, - O- (CH 2)} 2 -S -, - O- (CH 2) 3 -S
_{-, - N (CH 3)} -Ph-O -, - N (CH 3) -Ph
—S—, —N (Ph) — (CH ₂ ) ₂ —S— and the like.

In the present invention, the compounds represented by the general formulas (VII) to (IX) used as the superhigh contrast agent are
An adsorptive group that adsorbs to photosensitive silver halide may be incorporated. Examples of such adsorptive groups include U.S. Pat. Nos. 4,385,108 and 4,459,34 such as alkylthio, arylthio, thiourea, thioamide, mercapto heterocyclic and triazole groups.
7, JP-A-59-195233, and JP-A-59-195233.
JP-A-200231, JP-A-59-201045,
JP-A-59-201046, JP-A-59-201047, JP-A-59-201048, and JP-A-59-2010
No. 49, JP-A-61-170733, 61
-270744, 62-948, 63
-234244, 63-234245,
Groups described in JP-A-63-234246. The adsorbing groups for these photosensitive silver halides are
It may be a precursor. Examples of such a precursor include groups described in JP-A-2-285344.

The compounds represented by the general formulas (VII) to (IX) may contain a ballast group or a polymer commonly used in immobile photographic additives such as couplers. Particularly, those incorporating a ballast group are one of preferred examples of the present invention. A ballast group has a carbon number of 8 or more and is relatively inert to photographic properties, such as an alkyl group, an aralkyl group,
It can be selected from an alkoxyl group, a phenyl group, an alkylphenyl group, a phenoxy group, an alkylphenoxy group and the like. As the polymer, for example,
No. 100530 can be mentioned. The compounds represented by the general formulas (VII) to (IX) include a cationic group (specifically, a group containing a quaternary ammonium group or a nitrogen-containing hetero atom containing a quaternized nitrogen atom). A group containing a repeating unit of an ethyleneoxy group or a propyleneoxy group, an (alkyl, aryl, or heterocyclic) thio group, or a dissociable group (carboxyl group, sulfo group, acylsulfa Moyl group, carbamoylsulfamoyl group, etc.). Particularly, a group containing a group containing a repeating unit of an ethyleneoxy group or a propyleneoxy group, or a group containing an (alkyl, aryl, or heterocyclic) thio group is one of preferred examples of the present invention. Specific examples of these groups include, for example, JP-A-7-234471,
JP-A-5-333466, JP-A-6-19032,
JP-A-6-19031, JP-A-5-45761, U.S. Pat. No. 4,994,365, JP-A-4988884, JP-A-3-259240, and JP-A-7-5610.
JP, JP-A-7-244348, German Patent 4006
And the compounds described in JP-A-032. In the present invention, general formula (VI) used as a super-high contrast agent
The compounds represented by I) to (IX) can be easily synthesized by a known method. For example, US Pat.
No. 45515, No. 5635339, No. 5
654130, International Publication WO 97/34196
Gazette, Japanese Patent Application No. 9-354107, 9-30
The compound can be synthesized with reference to the methods described in JP-A-9813 and JP-A-9-272002. Hereinafter, in the present invention, the general formula (VI) used as a super-high contrast agent
Specific examples of the compounds represented by I) to (IX) are shown. However, the present invention is not limited to the following compounds.

[0097]

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[0098]

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[0099]

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[0100]

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In the photothermographic material of the present invention, the amount of the compounds represented by formulas (VII) to (IX) is preferably 1 × 10 ^-6 to 1 mol per 1 mol of silver.
More preferably, it is 1 × 10 ^{-5 to} 5 × 10 ^-1 mol, and further preferably, it is 2 × 10 ^-5 to 2 × 10 ^-1 mol.

The compounds represented by the general formulas (VII) to (IX) can be prepared from water or a suitable organic solvent such as alcohols (eg, methanol, ethanol, propanol, fluorinated alcohol) and ketones (eg, acetone, methyl ethyl ketone). , Dimethylformamide, dimethylsulfoxide, methylcellosolve and the like. In addition, by a known emulsification dispersion method, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone is dissolved to prepare a mechanically emulsified dispersion. Can be used. Alternatively, a powder of a compound represented by any of the general formulas (VII) to (IX) is placed in a suitable solvent such as water by a ball mill, a colloid mill,
Alternatively, they can be dispersed and used by ultrasonic waves.
The compounds represented by formulas (VII) to (IX) may be added to the layer on the image forming layer side with respect to the support, that is, the image forming layer or any other layer on the layer side. It is preferably added to the forming layer or a layer adjacent thereto.

The compounds represented by formulas (VII) to (IX) may be used alone or in combination of two or more. Also, in addition to those described above, US Pat.
No. 5,635,339, No. 565413
No. 0, International Publication WO97 / 34196, U.S. Pat. No. 5,686,228, JP-A-11-119.
372, Japanese Patent Application No. 9-228881, and 9
-273935, 9-354107, 9-309813, and 9-296174.
JP-A-11-282564, JP-A-11-282564
Compounds described in JP-A-95365, JP-A-11-95366, and Japanese Patent Application No. 9-332388 may be used in combination. Further, in the present invention, hydrazine derivatives described in JP-A-10-339932 and JP-A-10-161270 can be used in combination. Further, the following hydrazine derivatives can be used in combination. In other words, Tokuho 6-7713
No. 8 is a compound represented by (Chemical Formula 1), specifically, the compounds described on pages 3 and 4 of the same. 6-930
No. 82, a compound represented by the general formula (I),
Specifically, compounds 1 to 38 described on pages 8 to 18 of the publication. Compounds represented by general formulas (4) to (6) described in JP-A-6-230497, specifically, compounds 4-1 to 4-10 and 28-
Compounds 5-1 to 5-42 and 39 described on page 36,
Compounds 6-1 to 6-7 described on page 40. JP-A-6-28
No. 9520, compounds represented by formulas (1) and (2), specifically, compounds 1-1) to 1-17) and 2-1) described on pages 5 to 7 of the publication. . JP-A-6-31
Compounds represented by (Chemical Formula 2) and (Chemical Formula 3) described in JP-A-3936, specifically, compounds described on pages 6 to 19 of the same publication. Compounds represented by (Chemical Formula 1) described in JP-A-6-313951, specifically, compounds described on pages 3 to 5 of the same. A compound represented by the general formula (I) described in JP-A-7-5610.
Compounds I-1 to I-38 described on page. JP-A-7-777
No. 83, a compound represented by the general formula (II),
Specifically, the compounds II-1 to 11 described on pages 10 to 27 of the same publication are described.
II-102. Compounds represented by formulas (H) and (Ha) described in JP-A-7-104426, specifically, compounds H-1 to H-44 described on pages 8 to 15 of the same. A compound described in European Patent Publication No. 713131A1 which has an anionic group or a nonionic group which forms an intramolecular hydrogen bond with a hydrogen atom of hydrazine in the vicinity of a hydrazine group. ) To (F), specifically the compound N described in the publication
-1 to N-30. A compound represented by the general formula (1) described in European Patent Publication No. 713131A1, specifically, compounds D-1 to D-55 described in the publication.
"Known Technology (pages 1 to 207)" published on the 2nd (Aztec)
Various hydrazine derivatives described on pages 25-34. Compounds D-2 and D-39 of JP-A-62-86354 (pages 6 to 7).

The amount of these hydrazine derivatives used is silver
Preferably, 1 × 10 ^-6~ 1 mole,
More preferably 1 × 10^-Five~ 5 × 10^-1Is a mole
More preferably 2 × 10^-Five~ 2 × 10^-1Is a mole. Hi
The drazine derivatives are represented by the general formulas (VII) to (IX) described above.
Can be dispersed and used in the same manner as the compound represented by
Wear. The hydrazine derivative is used in the image forming layer
Side layer, i.e. the image forming layer or any other layer on this side
To the image forming layer or adjacent thereto.
It is preferable to add it to the layer. Further, in the present invention,
U.S. Pat.No. 5,545,515 as a super-high contrast agent
Acrylonitriles described in the above, specifically CN-1 to CN
-13 or the like can be used.

In the present invention, in order to form a super-high contrast image, a high-contrast accelerator can be used in combination with the above-mentioned super-high contrast agent. For example, the amine compounds described in U.S. Patent No. 5,545,505, specifically AM-1 to AM-5, 5,545,
The hydroxamic acids described in US Pat. No. 507, specifically H
A-1 to HA-11, hydrazine compounds described in the specification of JP-A-5,558,983, specifically CA-1 to CA-6, JP-A-9-29
No. 7368, onium salts, specifically A
-1 to A-42, B-1 to B-27, C-1 to C-14 and the like can be used. The synthesis method, addition method, addition amount, and the like of the above-mentioned super-high contrast agent and these high-contrast accelerators can be performed as described in each of the cited patents. In order to use formic acid or formate as a strong fogging substance, it is preferable to contain 5 mmol or less, more preferably 1 mmol or less, per mole of silver on the side having the image forming layer containing photosensitive silver halide. When a nucleating agent is used in the photothermographic material of the invention, it is preferable to use an acid formed by hydration of diphosphorus pentoxide or a salt thereof in combination. Acids or salts thereof formed by hydration of diphosphorus pentoxide include metaphosphoric acid (salt), pyrophosphoric acid (salt), orthophosphoric acid (salt), triphosphoric acid (salt), tetraphosphoric acid (salt), hexametaline Acids (salts) and the like can be mentioned. Particularly preferred acids or salts thereof formed by hydration of diphosphorus pentoxide include orthophosphoric acid (salt) and hexametaphosphoric acid (salt). Specific salts include:
Examples include sodium orthophosphate, sodium dihydrogen orthophosphate, sodium hexametaphosphate, and ammonium hexametaphosphate. Use amount of the oxidizing acid or salt thereof formed by hydration of diphosphorus (coating amount per photographic material 1 m ²⁾ may be a desired amount depending on the performance such as sensitivity and fog, but, 0.1 to 500 mg / m ² is preferred, and 0.5 to
100 mg / m ² is more preferred.

The photothermographic material of the present invention may be provided with a surface protective layer for the purpose of preventing adhesion of the image forming layer. The surface protective layer is described in paragraphs 0119 to 0120 of JP-A-11-65021. Gelatin is preferred as the binder for the surface protective layer, but polyvinyl alcohol (PVA) is also preferred. As PVA, completely saponified PVA-105 [polyvinyl alcohol (PVA) content 94.0% by weight or more, saponification degree 9
8.5 ± 0.5 mol%, sodium acetate content 1.5% by weight or less, volatile matter 5.0% by weight or less, viscosity (4% by weight, 2% by weight)
0 ° C.) 5.6 ± 0.4 CPS], PVA partially saponified
-205 [PVA content 94.0% by weight, saponification degree 8
8.0 ± 1.5 mol%, sodium acetate content 1.0% by weight, volatile matter 5.0% by weight, viscosity (4% by weight, 20 ° C.)
5.0 ± 0.4 CPS], modified polyvinyl alcohol MP-102, MP-202, MP-203, R-11
30, R-2105 (trade name of Kuraray Co., Ltd.)
And the like. 0.3 as polyvinyl alcohol coating amount of the protective layer (per one layer) (per support 1 m ²⁾
Preferably ^{4.0g / m 2, 0.3~2.0g / m} 2 is more preferable. In particular, when the photothermographic material of the present invention is used for printing in which dimensional change is a problem, it is preferable to use a polymer latex also for the protective layer and the back layer. For such polymer latex, see "Synthetic Resin Emulsion (Edited by Tadashi Okuda and Hiroshi Inagaki, published by Kobunshi Kankokai (1978))",
"Application of Synthetic Latex (Edited by Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, Polymer Publishing Association (199)
3))), "Science of synthetic latex (Souichi Muroi, published by Kobunshi Kankokai (1979))" and the like. Specifically, methyl methacrylate (33.5% by weight) / ethyl acrylate (50 % By weight) / methacrylic acid (16.
Latex of copolymer, latex of methyl methacrylate (47.5% by weight) / butadiene (47.5% by weight) / itaconic acid (5% by weight), latex of ethyl acrylate / methacrylic acid copolymer, methyl methacrylate (58.9% by weight)
/ 2-ethylhexyl acrylate (25.4% by weight)
/ Ethylene (8.6% by weight) / 2-hydroxyethyl methacrylate (5.1% by weight) / acrylic acid (2.0% by weight) copolymer latex. Further, as a binder for a protective layer, Japanese Patent Application No. 11-687.
No. 2, Japanese Patent Application No. 11-143058, paragraphs [0021] to [0000]
25, the technology described in paragraphs 0027 to 0028 of Japanese Patent Application No. 11-6872, and the technology described in Japanese Patent Application No.
The technology described in paragraph numbers 0023 to 0041 of the specification of 199626 may be applied.

The temperature for preparing the coating solution for the image forming layer is from 30 ° C. to 65 ° C.
More preferably, the temperature is 35 ° C to 60 ° C, and the more preferable temperature is 35 ° C to 55 ° C. The temperature of the coating solution for the image forming layer immediately after the addition of the polymer latex is preferably maintained at 30 ° C to 65 ° C. Further, it is preferable that the heat developer and the organic silver salt are mixed before the addition of the polymer latex.

The fluid containing the organic silver salt or the coating solution for the thermal image forming layer in the present invention is preferably a so-called thixotropic fluid. The thixotropic property refers to a property in which the viscosity decreases as the shear rate increases. Although any apparatus may be used for the viscosity measurement, an RFS fluid spectrometer manufactured by Rheometrics Far East Co., Ltd. is preferably used, and the viscosity is measured at 25 ° C. Here, the viscosity of the fluid containing the organic silver salt or the coating solution for the thermal image forming layer in the present invention at a shear rate of 0.1 S ^-1 is preferably from 400 to 100,000 mPa · s, more preferably from 500 to 20,000 mPa · s. Further, at a shear rate of 1000 S ^−1, it is preferably ¹ to 200 mPa · s, more preferably 5 to 80 mPa · s.

Various systems expressing thixotropy are known, and are described in “Lecture / Rheology”, edited by Polymer Publishing Association, Muroi,
It is described in Morino co-author, “Polymer Latex” (published by the Society of Polymer Publishing). In order for a fluid to exhibit thixotropic properties, it is necessary to contain a large amount of solid fine particles.
In order to enhance the thixotropic property, it is effective to include a thickened linear polymer, to increase the aspect ratio of the contained solid fine particles in an anisotropic shape, to increase the alkali thickening, and to use a surfactant.

The heat-developable photographic emulsion is composed of one or more layers on a support. One layer construction must include optional additional materials such as organic silver salts, silver halides, developers and binders, and toning agents, coating aids and other auxiliaries. The two-layer configuration is that the first emulsion layer (usually the layer adjacent to the support) contains an organic silver salt and silver halide, and the second layer or both layers do not contain some other components. No. However, a two-layer construction comprising a single emulsion layer containing all components and a protective topcoat is also contemplated. The composition of the multicolor photothermographic material may include a combination of these two layers for each color,
Also, all components may be contained in a single layer as described in US Pat. No. 4,708,928. In the case of a multi-dye, multi-color photothermographic material, each emulsion layer generally comprises a functional or non-functional barrier between the light-sensitive layers, as described in U.S. Pat.No. 4,460,681. The use of layers keeps them distinct from one another.

Various dyes and pigments can be used in the photosensitive layer from the viewpoints of improving color tone, preventing interference fringes during laser exposure, and preventing irradiation. These are described in detail in International Publication WO98 / 36322. Preferred dyes and pigments used in the photosensitive layer include anthraquinone dyes, azomethine dyes, indoaniline dyes, azo dyes, anthraquinone-based indanthrone pigments (CI
Pigment Blue 60), phthalocyanine pigments (CI Pigm
copper phthalocyanine such as ent Blue 15, CI Pigment Blue
16 non-metallic phthalocyanine, etc.), dyed lake pigment triarylcarbonyl pigments, indigo, inorganic pigments
(Ultra blue, cobalt blue, etc.). As a method for adding these dyes and pigments, any method such as a solution, an emulsion, a solid fine particle dispersion, or a state in which the dye or pigment is mordanted with a polymer mordant may be used. The amount of these compounds is determined by absorption of the purpose, generally the light-sensitive material 1 m ² per 1μg
It is preferable to use in the range of 1 to 1 g.

In the present invention, the antihalation layer can be provided on the side farther from the light source than the photosensitive layer. The antihalation layer is described in JP-A No. 11-65021, paragraphs 0123 to 0124 and 11-223898.

In the present invention, it is preferable to add a decoloring dye and a base precursor to the non-photosensitive layer of the photothermographic material so that the non-photosensitive layer functions as a filter layer or an antihalation layer. A photothermographic material generally has a non-photosensitive layer in addition to a photosensitive layer. The non-photosensitive layer may be arranged as follows: (1) a protective layer provided on the photosensitive layer (on the side farther than the support); (2) between a plurality of photosensitive layers or between the photosensitive layer and the protective layer. (3) an undercoat layer provided between the photosensitive layer and the support, and (4) a back layer provided on the opposite side of the photosensitive layer. The filter layer is provided on the photosensitive material as the layer (1) or (2). The antihalation layer is provided on the photosensitive material as the layer (3) or (4).

The decolorizing dye and the base precursor are preferably added to the same non-photosensitive layer. However, they may be separately added to two adjacent non-photosensitive layers. Further, a barrier layer may be provided between the two non-photosensitive layers.

As a method of adding the decolorizable dye to the non-photosensitive layer, a method of adding a solution, an emulsion, a solid fine particle dispersion or a polymer impregnated substance to the coating solution for the non-photosensitive layer can be adopted. Further, a dye may be added to the non-photosensitive layer using a polymer mordant. These addition methods are the same as the method of adding a dye to an ordinary photothermographic material. Latex used in polymer impregnation is disclosed in US Pat.
No. 99363, West German Patent Publication Nos. 25141274 and 2541230, European Patent Publication EP02
No. 9104 and JP-B-53-41091. Further, regarding an emulsification method for adding a dye to a solution in which a polymer is dissolved, International Publication WO88 / 00
No. 723. The amount of the decolorizable dye is determined depending on the use of the dye. Generally, the optical density (absorbance) measured at the target wavelength is used in an amount exceeding 0.1. The optical density is preferably from 0.2 to 2.
The amount of the dye used to obtain such an optical density is generally about 0.001 to 1 g / m ² , particularly preferably 0.01 to 1 g / m ^2.
About 0.2 g / m ² .

When the dye is decolored in this manner, the optical density can be reduced to 0.1 or less. Two or more decolorizable dyes may be used in combination in a heat-decolorable recording material or a photothermographic material. Similarly, two or more base precursors may be used in combination.

The photothermographic material according to the present invention may comprise a support
Contains at least one layer of silver halide emulsion on one side of
Having a photosensitive layer and a back layer on the other side, so-called
It is preferably a single-sided photosensitive material. In the present invention
Therefore, it is preferable to add a matting agent to improve transportability.
For matting agents, see paragraphs of JP-A-11-65021
Nos. 0126 to 0127. Matting agent is photosensitive material
1m^TwoWhen indicated by the applied amount per unit, preferably 1 to 400 mg
/ m ^Two, More preferably 5-300 mg / m^TwoIt is. Also, the emulsion surface
The matte degree is fine if stardust failure does not occur
However, Beck smoothness is preferably 30 seconds to 2000 seconds, particularly 40 seconds
~ 1500 seconds is preferred.

In the present invention, the matting degree of the back layer is preferably such that the Beck smoothness is from 10 seconds to 1200 seconds, and from 20 seconds to 800 seconds.
Seconds are preferable, and more preferably 40 seconds to 500 seconds.
In the present invention, the matting agent is preferably contained in the layer functioning as the outermost surface layer or the outermost surface layer of the light-sensitive material, or a layer close to the outer surface, and is contained in a layer acting as a so-called protective layer. Is preferred. The back layer that can be applied to the present invention is described in JP-A-11-650
No. 21, Publication No. 0128-0130.

A hardening agent may be used for each layer such as a photosensitive layer, a protective layer, and a back layer. THJames is an example of a hardener
By "THE THEORY OF THE PHOTOGRAPHIC PROCESS FOURTH
EDITION "(published by Macmillan Publishing Co., Inc., published in 1977), each method described on pages 77 to 87, polyvalent metal ions described on page 78 of the same book, U.S. Pat. No. 4,281,060, JP-A-6 Polyisocyanates such as JP-208193, epoxy compounds such as US Pat. No. 4,791,042, and vinylsulfone compounds such as JP-A-62-89048 are preferably used.

The hardener is added as a solution, and the solution is added to the coating solution for the protective layer from 180 minutes to immediately before coating, preferably from 60 minutes to 10 seconds before coating. The mixing conditions are not particularly limited as long as the effects of the present invention are sufficiently exhibited. As a specific mixing method, a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is set to a desired time, by N. Harnby, MFE Edwards, AW Nienow, translated by Koji Takahashi "Liquid mixing technology" (published by Nikkan Kogyo Shimbun, 1989)
There is a method using a static mixer described in Chapter 8 and the like.

For the surfactants applicable to the present invention, JP-A-11-65021, paragraph No. 0132, for solvents, paragraph No. 0133 of the same publication, for supports, paragraph No. 0134 of the same publication, antistatic or conductive The layers are described in paragraph number 0135 of the same publication, and the method of obtaining a color image is described in paragraph number 0136 of the same publication. The photothermographic material of the present invention preferably has a film surface pH before heat development treatment of 6.0 or less, more preferably 5.5 or less. The lower limit is not limited, but is about 3. The adjustment of the film surface pH is preferably performed using an organic acid such as a phthalic acid derivative, a nonvolatile acid such as sulfuric acid, or a volatile base such as ammonia from the viewpoint of reducing the film surface pH. In particular, ammonia is preferable in achieving a low film surface pH since ammonia is easily volatilized and can be removed before the application step and the heat development. The method of measuring the pH of the film surface is described in Japanese Patent Application No. 11-872.
No. 97, paragraph No. 0123. The transparent support is a polyester, especially polyethylene, which has been subjected to a heat treatment at a temperature in the range of 130 to 185 ° C. in order to alleviate internal strain remaining in the film during biaxial stretching and to eliminate heat shrinkage strain generated during heat development. Terephthalate is preferably used. In the case of a photothermographic material for medical use, the transparent support may be colored with a blue dye (for example, Dye-1 described in Examples of JP-A-8-240877) or may be uncolored. Examples of the support include a water-soluble polyester disclosed in JP-A-11-84574, a styrene-butadiene copolymer disclosed in JP-A-10-186565, and Japanese Patent Application No. 11-10688.
It is preferable to apply an undercoating technique such as a vinylidene chloride copolymer described in Paragraph Nos. 0063 to 0080 of the specification. Further, regarding the antistatic layer or the undercoat, JP-A-56-143430 and JP-A-56-1434.
No. 31, No. 58-62646, No. 56-12
0519, JP-A-11-84573, paragraphs 0040 to 0051, U.S. Pat.
7, the technology described in paragraphs 0078 to 0084 of JP-A-11-223898 can be applied.

The photothermographic material is preferably of a monosheet type (a type capable of forming an image on the photothermographic material without using another sheet such as an image receiving material).

The photothermographic material may further contain an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber or a coating aid. Various additives are added to either the photosensitive layer or the non-photosensitive layer. For these, International Publication WO98 / 36322, European Patent Publication EP803764A1, JP-A-10-186567, and JP-A-10-18568 can be referred to.

The photothermographic material of the present invention may be applied by any method. Specifically, extrusion coating, slide coating, curtain coating, dip coating, knife coating,
Various coating operations are used, including flow coating or extrusion coating using a hopper of the type described in U.S. Pat.
Kistler, “LIQUID FILM COATIN” by Peter M. Schweizer
G "(published by CHAPMAN & HALL, 1997), pp. 399 to 536, extrusion coating or slide coating is preferably used, and slide coating is particularly preferably used. An example is shown in Fig.
ure 11b.1. Also, if desired, p. 399 to 536
Two or more layers can be coated simultaneously by the method described on the page, U.S. Pat. No. 2,761,791 and GB 837,095.

The techniques that can be used in the photothermographic material of the present invention include European Patent Publication EP803764A1, European Patent Publication EP883022A1, International Publication WO98 / 36322, Japanese Patent Application Laid-Open No. 56-62648, No. 58-62644, JP-A-Hei.
No. 9-281637, No. 9-297367, No. 9-304869,
No. 9-311405, No. 9-329865, No. 10-10669, No. 10-62899, No. 10-69023, No. 10-18656
No. 8, No. 10-90823, No. 10-171063, No. 10
No. -186565, No. 10-186567, No. 10-186569 to No. 10-186572, No. 10-197974, No. 10-197
No. 982, No. 10-197983, No. 10-197985
No. 10-197987, No. 10-207001, No. 10-207004
No. 10-221807, No. 10-282601, No. 10
No. -288823, No. 10-288824, No. 10-307365, No. 10-312038, No. 10-339934, No. 11-710
No. 0, No. 11-15105, No. 11-24200, No. 11-
No. 24201, No. 11-30832, No. 11-84574,
No. 11-65021, No. 11-125880, No. 11-129629, No. 11-133536 to No. 11-133539, No. 11-1
Nos. 33542 and 11-133543 are also mentioned.

Although the photothermographic material of the present invention may be developed by any method, it is usually developed by raising the temperature of the photothermographic material exposed imagewise. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 140 ° C.
° C. The development time is preferably 1 to 180 seconds, and 10 to 180 seconds.
90 seconds is more preferable, and 10 to 40 seconds is particularly preferable.

As a method of thermal development, a plate heater method is preferable. The method described in JP-A-11-133572 is preferred as the heat development method using a plate heater method,
A heat developing apparatus for obtaining a visible image by contacting a photothermographic material having a latent image formed thereon with a heating unit in a heat development unit, wherein the heating unit comprises a plate heater, and one of the plate heaters A thermal developing apparatus, wherein a plurality of pressing rollers are disposed to face each other along a surface, and heat development is performed by passing the photothermographic material between the pressing roller and the plate heater. It is preferable to divide the plate heater into two to six stages and lower the temperature at the tip part by about 1 to 10 ° C. Such a method is disclosed in JP-A-54-300.
It is also described in No. 32 publication, water and organic solvents contained in the photothermographic material can be excluded from the system,
Further, it is possible to suppress a change in the shape of the support of the photothermographic material due to rapid heating of the photothermographic material.

The photothermographic material of the present invention may be exposed by any method, but a laser beam is preferred as an exposure light source. As the laser beam according to the present invention, a gas laser
(Ar ⁺ , He-Ne), a YAG laser, a dye laser, a semiconductor laser and the like are preferable. Further, a semiconductor laser and a second harmonic generation element can be used. Preferably, a gas or semiconductor laser emitting red to infrared light is used.

As the laser beam, a single mode laser can be used, but the technique described in paragraph No. 0140 of JP-A-11-65021 can be used. As laser output,
It is preferably 1 mW or more, more preferably 10 mW or more, and even more preferably high output of 40 mW or more. At that time, a plurality of lasers may be combined. The laser beam diameter is 30 to 1 / e ² spot size of Gaussian beam.
It can be about 200 μm. As a laser imager having an exposure section and a heat development section, Fuji Medical Dry Laser Imager FM-DPL can be mentioned. Regarding FM-DPL, refer to Fuji Medical Rev.
iew No. 8, pages 39 to 55, and it goes without saying that those techniques are applied as a laser imager for the photothermographic material of the present invention.

The photothermographic material of the present invention forms a black-and-white image by a silver image, and is used for medical diagnosis, photothermographic material for industrial photography, photothermographic material for printing, COM
Is preferably used as a photothermographic material.
In these uses, based on the formed black-and-white image, a duplicate image is formed on a duplication film MI-Dup manufactured by Fuji Photo Film Co., Ltd. for medical diagnostics, or Fuji Photo Film Co., Ltd. ) Return film DO-175, PDO-1
Needless to say, it can be used as a mask for forming an image on 00 or an offset printing plate. Also, DICO
The present invention can also be applied as a photothermographic material for a laser imager in "AD network" proposed by Fuji Medical System as a network system conforming to the M standard.

[0131]

The present invention will be described more specifically with reference to the following examples. Materials, reagents, ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples.

Example 1 The structure of the compound used in Example 1 is shown below.

[0133]

Embedded image

<< Preparation of PET Support >> Intrinsic viscosity IV = 0.66 (measured at 25 ° C. in phenol / tetrachloroethane = 6/4 (weight ratio)) using terephthalic acid and ethylene glycol according to a conventional method. Got PET. After pelletizing this, 4
After drying at 300 ° C., the mixture was melted at 300 ° C., extruded from a T-die, and quenched to prepare an unstretched film having a thickness of 175 μm after heat setting. This was longitudinally stretched 3.3 times using rolls having different peripheral speeds, and then laterally stretched 4.5 times using a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. After that, it was heat-set at 240 ° C. for 20 seconds and relaxed 4% in the lateral direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling was performed on both ends and wound at 4 kg / cm ² to obtain a roll having a thickness of 175 μm.

<< Surface Corona Treatment >> Using a solid state corona treatment machine 6KVA model manufactured by Pillar Co., both surfaces of the support were treated at room temperature at 20 m / min. From the current and voltage readings at this time, it was found that the support was treated at 0.375 kV · A · min / m ² . At this time, the processing frequency was 9.6 kHz, and the gap clearance between the electrode and the dielectric roll was 1.6 mm.

<< Preparation of Undercoating Support >> (1) Preparation of Undercoating Layer Coating Formulation 1 (for undercoating layer on photosensitive layer side) Takamatsu Yushi Co., Ltd. Pesresin A-515GB (30% by weight solution) 234 g polyethylene glycol mono Nonyl phenyl ether (average ethylene oxide number = 8.5) 10% by weight solution 21.5 g Soken Chemical Co., Ltd. MP-1000 (polymer fine particles, average particle size 0.4 μm) 0.91 g distilled water 744 ml

Formulation 2 (for the backside first layer) Butadiene-styrene copolymer latex 158 g (solid content 40% by weight, butadiene / styrene weight ratio = 32/68) 2,4-dichloro-6-hydroxy-S- Triazine sodium salt 8% by weight aqueous solution 20g 1% by weight aqueous solution of sodium laurylbenzenesulfonate 10ml Distilled water 854ml

Formulation 3 (for back surface side second layer) SnO ₂ / SbO (9/1 weight ratio, average particle size 0.038 μm, 17% by weight dispersion) 84 g Gelatin (10% aqueous solution) 89.2 g Shin-Etsu Chemical Co., Ltd. ) Metrolose TC-5 (2% aqueous solution) 8.6 g MP-1000 (polymer fine particles) manufactured by Soken Chemical Co., Ltd. 0.01 g 1 wt% aqueous solution of sodium dodecylbenzenesulfonate 10 ml NaOH (1%) 6 ml Proxel (manufactured by ICI) ) 1ml distilled water 805ml

<< Preparation of Undercoating Support >> The above thickness of 175 μm
After performing the above-described corona discharge treatment on both surfaces of the biaxially stretched polyethylene terephthalate support having a thickness of m, the undercoating coating solution formulation 1 was coated on one surface (photosensitive layer surface) with a wire bar at a wet application amount of 6.6 ml / m ² (one surface). ) And dried at 180 ° C for 5 minutes. Then, undercoat (coating solution formulation 2) was applied to the back surface (back surface) with a wire bar so that the wet application amount was 5.7 ml / m ^2. dried for 5 minutes at 180 ° C., dried undercoated support further 6 minutes undercoating liquid formulation 3 on the back surface (back surface) in the coating to 180 ° C. as the amount of wet coating with a wire bar is 7.7 ml / m ² Created body.

<< Preparation of Back Surface Coating Solution >> (1) Preparation of Solid Precursor Dispersion (a) of Base Precursor 64 g of base precursor compound 11, 28 g of diphenylsulfone, and 10 g of surfactant Demol N manufactured by Kao Corporation were added. Mix with 220 ml of distilled water and mix the mixture with a sand mill (1/4 Gallo
The beads were dispersed using an n-sand grinder mill (manufactured by Imex Co., Ltd.) to obtain a solid precursor dispersion (a) of a base precursor compound having an average particle diameter of 0.2 μm.

(2) Preparation of Dye Solid Fine Particle Dispersion A cyanine dye compound 9.6 g and sodium p-dodecylbenzenesulfonate 5.8 g were mixed with 305 ml of distilled water, and the mixture was sand-milled (1/4 Gallon sand grinder mill). The dispersion was performed using beads (manufactured by IMEX Co., Ltd.) to obtain a dye solid fine particle dispersion having an average particle diameter of 0.2 μm.

(3) Preparation of antihalation layer coating solution Gelatin 17 g, polyacrylamide 9.6 g, solid fine particle dispersion of base precursor (a) 70 g, dye solid fine particle dispersion 56 g, polymethyl methacrylate fine particles (average particle size (6.5 μm) 1.5 g, Benzoisothiazolinone 0.03
g, sodium polyethylene sulfonate 2.2 g, blue dye compound 14 0.2 g, and water 844 ml were mixed to prepare an antihalation layer coating solution.

<< Preparation of Back Surface Protective Layer Coating Solution >>
℃, gelatin 50g, polystyrene sodium sulfonate 0.2g, N, N-ethylenebis (vinylsulfoneacetamide) 2.4g, t-octylphenoxyethoxyethaneethanesulfonate 1g, benzoisothiazolinone 30mg, N-perfluoro Octylsulfonyl-N-propylalanine potassium salt 37 mg, polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-
2-aminoethyl) ether [average degree of polymerization of ethylene oxide 15] 0.15 g, C ₈ F ₁₇ SO ₃ K 32 mg, C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) (CH ₂
CH ₂ O) ₄ (CH ₂ ) ₄ —SO ₃ Na 64 mg, acrylic acid / ethyl acrylate copolymer (copolymerization weight ratio 5/95) 8.8 g, Aerosol OT (manufactured by American Cyanamid Co.) 0.6 g, 1.8 g of liquid paraffin emulsion as liquid paraffin, 950 ml of water
The mixture was mixed to give a back surface protective layer coating solution.

<< Preparation of Silver Halide Emulsion 1 >> Distilled water 1421
8.0 ml of a 1% by weight potassium bromide solution was added to each ml, and 8.2 ml of 1N nitric acid was further added thereto.A solution obtained by adding 20 g of phthalated gelatin was stirred at 37 ° C. in a titanium-coated stainless steel reaction bottle.
The solution A was diluted to 159 ml by adding distilled water to 37.04 g of silver nitrate, and 32.6 g of potassium bromide was dissolved in distilled water to a volume of 200 ml.
A solution B diluted to ml was prepared, and the entire amount of the solution A was added at a constant flow rate over 1 minute while maintaining the pAg at 8.1 by the control double jet method. Solution B was added by a controlled double jet method. Thereafter, 30 ml of a 3.5% by weight aqueous hydrogen peroxide solution was added, and 36 ml of a 3% by weight aqueous solution of benzimidazole was further added. Then, solution A2 was again diluted with distilled water to 317.5 ml, and solution B was dissolved with potassium trichloride iridate 3 potassium salt in solution B so that the final concentration was 1 × 10 ^-4 mole per mole of silver. Using the solution B2 diluted with distilled water to 400 ml twice the volume of the solution B, again by the controlled double jet method, while maintaining the pAg at 8.1, apply the solution A2 at a constant flow rate for 10 minutes. The whole amount was added. Solution B2 was added by a controlled double jet method. Thereafter, 50 ml of a 0.5% by weight methanol solution of 5-methyl-2-mercaptobenzimidazole was added, the pAg was further raised to 7.5 with silver nitrate, the pH was adjusted to 3.8 with 1N sulfuric acid, stirring was stopped, and sedimentation was stopped. A desalting / washing step was performed, 3.5 g of deionized gelatin was added, and 1N sodium hydroxide was added to adjust the pH to 6.0 and a pAg of 8.2 to prepare a silver halide dispersion. The grains in the completed silver halide emulsion were pure silver bromide grains having an average equivalent sphere diameter of 0.053 μm and a variation coefficient of equivalent sphere diameter of 18%. Particle size, etc. were determined using an electron microscope.
It was determined from the average of 00 particles. The [100] plane ratio of these particles was determined to be 85% using the Kubelka-Munk method.

The above emulsion was maintained at 38 ° C. with stirring,
0.035 g of benzoisothiazolinone (added in a 3.5% by weight methanol solution) was added, and after 40 minutes, a solid dispersion of the spectral sensitizing dye A (aqueous gelatin solution) was added at 5 × 10 ^-3 mol per mol of silver,
One minute later, the temperature was raised to 47 ° C., 20 minutes later, 3 × 10 ⁻⁵ mol of sodium benzenethiosulfonate was added to 1 mol of silver, and 2 minutes later, tellurium sensitizer B was added at ⁵ × 10 ⁵ mol / mol of silver. ^-5 mol was added and the mixture was aged for 90 minutes. Immediately before the completion of ripening, a 0.5% by weight methanol solution of N, N-dihydroxy-N-diethylmelamine was added to 5
ml, lower the temperature to 31 ° C and add phenoxyethanol.
5% by weight of a 3.5% by weight methanol solution, 5-methyl-2-mercaptobenzimidazole was converted to 7 × 10 ^-3 mol per mol of silver and 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole was converted to silver. 6.4 × 10 ^-3 mol was added per 1 mol to prepare a silver halide emulsion 1.

<< Preparation of Silver Halide Emulsion 2 >> In the preparation of silver halide emulsion 1, the liquid temperature at the time of grain formation was changed from 37 ° C. to 50 ° C.
In the same manner, a pure silver bromide cubic grain emulsion having an average equivalent sphere diameter of 0.08 μm and a coefficient of variation of equivalent sphere diameter of 15% was prepared in the same manner. Precipitation / desalting / water washing /
Dispersion was performed. Further, spectral sensitization, chemical sensitization, and 5-methyl-2-mercaptobenzimidazole were carried out in the same manner as in Emulsion 1, except that the amount of the spectral sensitizing dye A was changed to 4.5 × 10 ^-3 mol per mol of silver. 1-phenyl-2-heptyl-5-mercapto-
Addition of 1,3,4-triazole and silver halide emulsion 2
I got

<< Preparation of Silver Halide Emulsion 3 >> In the preparation of silver halide emulsion 1, the liquid temperature at the time of grain formation was changed from 37 ° C. to 27 ° C.
In the same manner, a pure silver bromide cubic grain emulsion having an average equivalent spherical diameter of 0.038 μm and a coefficient of variation of equivalent spherical diameter of 20% was prepared in the same manner. Precipitation / desalting / water washing /
Dispersion was performed. Further, spectral sensitization, chemical sensitization and 5-methyl-2-mercaptobenzimidazole were carried out in the same manner as in Emulsion 1, except that the addition amount of the spectral sensitizing dye A was changed to 6 × 10 ^-3 mol per mol of silver. 1-phenyl-2-heptyl-5-mercapto-1,
3,4-Triazole was added to obtain a silver halide emulsion 3.

<< Preparation of Coating Emulsion A for Coating Liquid >> Silver halide emulsion 1 was 70% by weight, silver halide emulsion 2 was 15% by weight,
Silver halide emulsion 3 was dissolved at 15% by weight, and benzothiazolium iodide was dissolved in a 1% by weight aqueous solution at a concentration of 7 × 1 per mole of silver.
0 ^-3 mol was added.

<< Preparation of scaly fatty acid silver salt >> 87.6 g of behenic acid (product name: Edenor C22-85R) manufactured by Henkel, 423 distilled water
Then, 49.2 ml of 5N-NaOH aqueous solution and 120 ml of tert-butanol were mixed, and the mixture was stirred and reacted at 75 ° C. for 1 hour to obtain a sodium behenate solution. Separately, an aqueous solution of 40.4 g of silver nitrate 206.2 ml
(PH 4.0) was prepared and kept at 10 ° C. A reaction vessel containing 635 ml of distilled water and 30 ml of tert-butanol was kept at 30 ° C., and while stirring, the whole amount of the sodium behenate solution and the whole amount of the silver nitrate aqueous solution were kept at a constant flow rate for 62 minutes and 10 seconds, respectively.
Added over 60 minutes. At this time, only the aqueous silver nitrate solution was added for 7 minutes and 20 seconds after the start of the aqueous silver nitrate solution addition, and then the addition of the sodium behenate solution was started. After the addition of the aqueous silver nitrate solution was completed, only the sodium behenate solution was added for 9 minutes and 30 seconds. Was added. At this time, the temperature in the reaction vessel was 30 ° C., and the external temperature was controlled so that the liquid temperature was constant. Further, the piping of the addition system of the sodium behenate solution was kept warm by steam tracing, and the steam opening was adjusted so that the liquid temperature at the outlet at the tip of the addition nozzle became 75 ° C. Also, the piping for the addition system of the silver nitrate aqueous solution is
The temperature was maintained by circulating cold water outside the double tube.
The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution. After the completion of the addition of the sodium behenate solution, the mixture was allowed to stir at the same temperature for 20 minutes, and the temperature was lowered to 25 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtered water became 30 μS / cm. Thus, a fatty acid silver salt was obtained. The obtained solid content was stored as a wet cake without drying.

The morphology of the obtained silver behenate particles was evaluated by electron microscopic photographing. The average values were a = 0.14 μm and b =
It was a scaly crystal having 0.4 μm, c = 0.6 μm, an average aspect ratio of 5.2, an average equivalent sphere diameter of 0.52 μm, and a variation coefficient of equivalent sphere diameter of 15%. (A, b, c are prescribed in the text) 7.4 g of polyvinyl alcohol (trade name: PVA-217, average degree of polymerization of about 1700) and water are added to a wet cake having a dry solid content of 100 g, and the total amount is 385 g. And then predispersed with a homomixer. Next, the pressure of the predispersed stock solution was adjusted to 1750 kg / cm ² by using a dispersing machine (trade name: Microfluidizer M-110S-EH, manufactured by Microfluidics International Corporation, using a G10Z interaction chamber). This was repeated to obtain a silver behenate dispersion. For the cooling operation, a coiled heat exchanger was mounted before and after the interaction chamber, and the dispersion temperature was set at 18 ° C. by adjusting the temperature of the refrigerant.

<< Preparation of 25% by weight dispersion of reducing agent >> 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane (Compound Example I-1 of the present invention) 10 kg and modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203)
16 kg of water was added to 10 kg of a 20% by weight aqueous solution of the above, and mixed well to form a slurry. The slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours and 30 minutes, and then benzoisothiazolinone sodium salt 0.2 g and water were added to adjust the concentration of the reducing agent to 25% by weight to obtain a reducing agent dispersion. The reducing agent particles contained in the reducing agent dispersion thus obtained have a median diameter of 0.40 μm.
m, and the maximum particle size was 1.8 μm or less. The resulting reducing agent dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of a 10% by weight dispersion of a mercapto compound >> 5 kg of 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole and modified polyvinyl alcohol (Kuraray)
8.3 kg of water in 5 kg of a 20% by weight aqueous solution of Poval MP203 manufactured by Co., Ltd.
Was added and mixed well to form a slurry. The slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 6 hours, and then water was added to reduce the concentration of the mercapto compound. It was adjusted to 10% by weight to obtain a mercapto dispersion. The mercapto compound particles contained in the mercapto compound dispersion thus obtained had a median diameter of 0.40 μm and a maximum particle diameter of 2.0 μm or less. The obtained mercapto compound dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored. Immediately before use, the mixture was again filtered through a polypropylene filter having a pore size of 10 μm.

<< Preparation of 20% by weight dispersion of organic polyhalogen compound-1 >> 5 kg of tribromomethylnaphthyl sulfone
And modified polyvinyl alcohol (Poval MP manufactured by Kuraray Co., Ltd.)
203) 2.5 kg of a 20% by weight aqueous solution, and 213 g of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate,
10 kg of water was added and mixed well to form a slurry. This slurry is sent by a diaphragm pump and has an average diameter of 0.5 m.
m zirconia beads filled horizontal sand mill (UVM-
2: manufactured by IMEX Co., Ltd.) for 5 hours, and then added with 0.2 g of benzoisothiazolinone sodium salt and water to adjust the concentration of the organic polyhalogen compound to 20% by weight. A dispersion was obtained. The organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained have a median diameter of 0.36 μm and a maximum particle diameter of 2.0 μm.
m or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of 25% by weight dispersion of organic polyhalogen compound-2 >> Similar to 20% by weight dispersion of organic polyhalogen compound-1, except that 5 kg of tribromomethylnaphthyl sulfone was used instead of N-butyl- 5 kg of 3-tribromomethanesulfonylbenzamide was dispersed, diluted so that the organic polyhalogen compound became 25% by weight, and filtered. Organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained have a median diameter of 0.
It was 39 μm and the maximum particle size was 2.2 μm or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of 30% by weight dispersion of organic polyhalogen compound-3 >> Similar to 20% by weight dispersion of organic polyhalogen compound-1 except that 5 kg of tribromomethylnaphthyl sulfone was used instead of tribromomethylphenyl Sulfone 5
5 kg of a 20 wt% aqueous solution of MP203 was dispersed in 5 kg, and the mixture was diluted so that the organic polyhalogen compound became 30 wt%, followed by filtration. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained had a median diameter of 0.41 μm and a maximum particle diameter of 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored. After storage, it was stored at 10 ° C or less until use.

<< Preparation of 5% by weight solution of phthalazine compound >>
8 kg of Kuraray's modified polyvinyl alcohol MP203 was dissolved in 174.57 kg of water, and then 3.15 kg of a 20% aqueous solution of sodium triisopropylnaphthalenesulfonate and 14.28 kg of a 70% aqueous solution of 6-isopropylphthalazine were added. A 5% by weight solution of 6-isopropylphthalazine was prepared.

<< Preparation of 20% by weight dispersion of pigment >>
64 g of nt Blue 60 and 6.4 g of Demol N manufactured by Kao Corporation in 250 g of water
Was added and mixed well to obtain a slurry. Average diameter 0.5mm
Of zirconia beads was placed in a vessel together with the slurry, and dispersed by a dispersing machine (1 / 4G sand grinder mill: manufactured by Imex Co., Ltd.) for 25 hours to obtain a pigment dispersion. The pigment particles contained in the pigment dispersion thus obtained had an average particle size of 0.21 μm.

<< Preparation of SBR latex 40% by weight >> Ultrafiltration
(UF) The purified SBR latex was obtained as follows. The following SBR latex diluted 10 times with distilled water was diluted using UF-purification module FS03-FC-FUY03A1 (Daisen Membrane System Co., Ltd.) until the ionic conductivity became 1.5 mS / cm. Purify and use Sandet-BL manufactured by Sanyo Chemical Co., Ltd.
It was added to be 0.22% by weight. Further with NaOH and NH ₄ OH Na ⁺ ion: NH ₄ ⁺ ion = 1: was added to a 2.3 (molar ratio) was adjusted to pH 8.4. The latex concentration at this time was 40% by weight. (SBR latex: -St (68) -Bu (29) -AA (3)-latex)
Average particle size 0.1 μm, concentration 45%, equilibrium water content 0.6% by weight at 25 ° C. and 60% relative humidity, ion conductivity 4.2 mS / cm (Ion conductivity is measured by a conductivity meter CM- manufactured by Toa Denpa Kogyo Co., Ltd. Using 30S, measure latex stock solution (40%) at 25 ° C), pH 8.2

<< Preparation of Coating Solution for Image Forming Layer >> 1.1 g of a 20% by weight aqueous dispersion of the pigment obtained above, 103 g of a silver salt of an organic acid, and 20% by weight of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.) 5% aqueous solution, 25 g of the above 25% by weight reducing agent dispersion, organic polyhalogen compound dispersion-1, -2, -3 in a total amount of 13.2 in a ratio of 2: 5: 2 (weight ratio).
g, 10 g of a 10% dispersion of a mercapto compound, 106 g of 40 wt% of SBR latex purified and pH-adjusted by ultrafiltration (UF), and 18 ml of a 5 wt% solution of a phthalazine compound were added. Mix well 10g, image forming layer (photosensitive layer,
Emulsion layer) Prepare a coating solution and transfer it directly to the coating die
The solution was fed to 70 ml / m ² and applied. The viscosity of the image forming layer coating solution was measured with a B-type viscometer of Tokyo Keiki Co., Ltd.
It was 85 [mPa · s] at ° C (No. 1 rotor, 60 rpm). The viscosity of the coating solution at 25 ° C. using a Rheometrics Far East Co., Ltd. RFS Fluid Spectrometer was 1500, 220, 70, 40, at a shear rate of 0.1, 1, 10, 100, 1000 [1 / sec], respectively. It was 20 [mPa · s].

<< Preparation of Emulsion Surface Intermediate Layer Coating Solution >> A 10% by weight aqueous solution of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.)
g, 20% by weight dispersion of pigment 5.3 g, methyl methacrylate /
Styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer weight ratio 64/9/20/5 /
2) Latex 27.5 wt% liquid 226 g 5 wt% aqueous solution of aerosol OT (manufactured by American Cyanamid) 2 ml, 20 wt% aqueous solution of diammonium phthalate 10.5 ml, total amount 880 g
Was added to make the coating solution for the intermediate layer, and the solution was fed to the coating die at 10 ml / m ² . The viscosity of the coating solution is 21 mPa · s using a B-type viscometer at 40 ° C (No. 1 rotor, 60 rpm).
Met.

<< Preparation of Coating Solution for First Layer of Emulsion Surface Protective Layer >> 64 g of inert gelatin was dissolved in water, and methyl methacrylate was added.
/ Styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer weight ratio 64/9/20
/ 5/2) 27.5% by weight of latex 80g liquid, 10% by weight of phthalic acid
23 ml of a methanol solution, 23 ml of a 10% by weight aqueous solution of 4-methylphthalic acid, 28 ml of 1N sulfuric acid, 5 ml of a 5% by weight aqueous solution of Aerosol OT (manufactured by American Cyanamid), 0.5 g of phenoxyethanol, 0.1 g of benzoisothiazolinone 0.1 g
Water was added to make a total amount of 750 g to form a coating solution, and a mixture of 26% of 4% by weight chromium alum mixed with a static mixer immediately before coating was sent to a coating die at 18.6 ml / m ² . The viscosity of the coating solution was measured using a B-type viscometer at 40 ° C (No. 1
Rotor, 60 rpm) was 17 [mPa · s].

<< Preparation of Coating Solution for Second Layer of Emulsion Surface Protective Layer >> 80 g of inert gelatin was dissolved in water, and methyl methacrylate was added.
/ Styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer weight ratio 64/9/20
/ 5/2) 102 g of latex 27.5% by weight liquid, 5% of N-perfluorooctylsulfonyl-N-propylalanine potassium salt
3.2 ml of a 2% by weight solution of polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [average degree of polymerization of ethylene oxide = 15] was 32 ml, and Aerosol OT (American Cyclic) was used. 23 ml of a 5% by weight solution of Anamid Co., Ltd., 4 g of polymethyl methacrylate fine particles (average particle size 0.7 μm), 21 g of polymethyl methacrylate fine particles (average particle size 6.4 μm), 1.6 g of 4-methylphthalic acid, 4.8 g of phthalic acid , 44 ml of 1N sulfuric acid, 10 mg of benzoisothiazolinone and water to a total amount of 650 g,
The weight% of chromium alum and 0.67 weight% of the surface protective layer coating solution which had been mixed with a static mixer solution 445ml containing phthalic acid immediately before coating, fed to a coating die so that 8.3 ml / m ² did. The viscosity of the coating solution was 9 mPa · s using a B-type viscometer at 40 ° C. (No. 1 rotor, 60 rpm).

<< Preparation of Photothermographic Material >> On the back surface side of the undercoating support, a coating solution for the antihalation layer was applied so that the solid content of the solid fine particle dye was 0.04 g / m ² and the back surface was protected. The layer coating solution was simultaneously layer-coated so that the gelatin coating amount was 1.7 g / m ^2, and dried to form an antihalation back layer. On the side opposite to the back side, from the undercoat side to the image forming layer (silver halide coated silver amount 0.14 g / m ² ), intermediate layer, protective layer first layer, protective layer second layer in order of slide bead coating method To form a sample 001 of the photothermographic material.

The coating is performed at a speed of 160 m / min, the distance between the tip of the coating die and the support is set to 0.14 to 0.28 mm, and the coating width is spread by 0.5 mm on both the left and right sides with respect to the slit width of the coating liquid. The pressure was adjusted and the pressure in the decompression chamber was set 392 Pa lower than the atmospheric pressure. At that time, the handling and the temperature and humidity were controlled so that the support was not charged, and the charge was removed by ion wind immediately before coating. In the subsequent chilling zone, air with a dry-bulb temperature of 18 ° C and a wet-bulb temperature of 12 ° C was blown for 30 seconds to cool the coating liquid, and then the dry-bulb temperature was raised in the hovering-type floating type drying zone. After spraying dry air at 30 ° C and wet bulb temperature of 18 ° C for 200 seconds, passing through a 70 ° C drying zone for 20 seconds, then passing through a 90 ° C drying zone for 10 seconds, and then 25 ° C
And the solvent in the coating solution was volatilized. The average wind speed of the wind blowing on the coating liquid film surface in the chilling zone and the drying zone was 7 m / sec. The matte degree of the prepared photothermographic material was 550 on the image forming layer side with Beck smoothness.
Seconds, the back side was 130 seconds. As shown in Table 1, the coating amounts of the phenolic reducing agent (compound of the general formula (I)) and the compound satisfying at least one of the conditions A and B were set so as to give a development density almost equivalent to that of the sample 101. Adjusted samples 102 to 123 were prepared and evaluated for image storability. In preparing the sample, the phenol-based reducing agent (compound of the general formula (I)) was prepared using 1,1-bis (2-hydroxy-3,5-dimethylphenyl)-used in a 25% dispersion of the reducing agent.
It was prepared by using instead of 3,5,5-trimethylhexane.
Compound (II-2) of Sample 102 contained the following dispersion after application of the image forming layer. The amount used was such that it was equimolar to the reducing agent. For Samples 103 to 123, the compounds described in Table 1 were dispersed in the same manner, and the amounts of the compounds described in Table 1 (relative mol% with the amount of compound II-2 as 100) were used.
).

<< Preparation of Dispersion of Compound II-2 >> 1.6 kg of water was added to 1 kg of the compound II-2 and 1 kg of a 20% by weight aqueous solution of modified polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.). The mixture was mixed well to form a slurry. This slurry was fed by a diaphragm pump and filled with zirconia beads having an average diameter of 0.5 mm in a horizontal sand mill (manufactured by Imex Co., Ltd., UVM-
After 3 hours and 30 minutes of dispersion in 2), 0.2 g of besoisothiazolinone sodium salt and water are added to adjust the concentration of the phosphoryl compound to 25% by weight, and a solid fine particle dispersion of the phosphoryl compound is prepared. Obtained. The phosphoryl compound particles contained in the dispersion thus obtained have a median diameter of 0.1.
The particle size was 45 μm, and the maximum particle size was 2.0 μm or less. The obtained dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

Evaluation of image storability was performed by storing the photosensitive material after thermal development at 60 ° C. and a relative humidity of 50% for one day, and measuring a density change ΔDmin of a white background before and after the storage. The results are shown in Table 1.

[0167]

[Table 1]

As is evident from Table 1, the combination of the present invention significantly improves image storability.

(Example 2) Silver halide emulsions 1 to 3 used in Example 1, mixed emulsion A for coating, reducing agent solid fine particle dispersion, 25% by weight dispersion of organic polyhalogen compound-2,
30% by weight dispersion of organic polyhalogen compound-3, the image forming layer coating solution was changed to that prepared by the following method, and further, using a phosphoryl compound dispersion, thermal development was performed in the same procedure as in Example 1. A photosensitive material was obtained.

<< Preparation of Silver Halide Emulsion 1 >> Distilled water 1421
Add 3.1 ml of a 1% by weight potassium bromide solution to the
While stirring the liquid containing 3.5 ml of 1N sulfuric acid and 31.7 g of phthalated gelatin in a titanium-coated stainless steel reaction pot, the liquid temperature was maintained at 34 ° C., and distilled water was added to 22.22 g of silver nitrate.
Solution A diluted to 5.4 ml and solution B prepared by diluting 15.9 g of potassium bromide to a volume of 97.4 ml with distilled water were all added at a constant flow rate over 45 seconds. Thereafter, 10 ml of a 3.5% by weight aqueous hydrogen peroxide solution was added, and further 10.8 ml of a 10% by weight aqueous solution of benzimidazole was added. In addition, 51.86 g of silver nitrate
Solution D diluted with distilled water to 317.5 ml and solution D prepared by diluting potassium bromide 45.8 g with distilled water to a volume of 400 ml.
Was added over 20 minutes at a constant flow rate, and solution D was added by a controlled double jet method while maintaining pAg at 8.1. Potassium hexachloride (III) acid salt was added in a total amount of 10 × 10 ⁻⁴ mol per mol of silver 10 minutes after the start of addition of Solution C and Solution D. Five seconds after the completion of the addition of the solution C, an aqueous solution of potassium hexacyanoferrate (II) was added in an amount of 3 × 10 ^-4 mol per mol of silver.
The pH was adjusted to 3.8 using 1N sulfuric acid, the stirring was stopped, and a settling / desalting / water washing step was performed. The pH was adjusted to 5.9 with 1N sodium hydroxide to prepare a silver halide dispersion having a pAg of 8.0.

While stirring the above silver halide dispersion, 38
C. and 0.34% by weight of 1,2-benzisothiazoline
5 ml of a methanol solution of -3-one was added, and 40 minutes later, a methanol solution of the spectral sensitizing dye A described below was added to 1 × 10
^-3 mol was added, and the temperature was raised to 47 ° C one minute later. Twenty minutes after the temperature was raised, sodium benzenethiosulfonate was added in an amount of 7.6 × 10 ⁻⁵ mol per mol of silver with a methanol solution. 10 ^-4 mol was added and the mixture was aged for 91 minutes. 0.8% by weight methanol solution of N, N'-dihydroxy-N "-diethylmelamine
1.3 ml was added, and after another 4 minutes, 5-methyl-2-mercaptobenzimidazole was dissolved in a methanol solution at 3.7 × 10 ^-3 mol per mol of silver and 1-phenyl-2-heptyl-5-mercapto-1,3. 4.9 × 10 ^-3 mol of 1,4-triazole was added to 1 mol of silver in a methanol solution to give a silver halide emulsion 1
It was created. The grains in the prepared silver halide emulsion are:
Pure silver bromide particles having an average equivalent spherical diameter of 0.046 μm and a coefficient of variation of equivalent spherical diameter of 20% were obtained. Use an electron microscope to determine particle size, etc.
It was determined from the average of 1000 particles. The [100] plane ratio of these particles was determined to be 80% using the Kubelka-Munk method.

<< Preparation of Silver Halide Emulsion 2 >> In the preparation of Silver Halide Emulsion 1, the liquid temperature at the time of grain formation was changed from 34 ° C. to 49 ° C.
To 30 minutes, and the addition time of solution C was changed to 30 minutes.
(II) Silver halide emulsion 2 was prepared in the same manner except that potassium was removed. Precipitation / desalting / washing / dispersion was carried out in the same manner as in silver halide emulsion 1. Further, spectral sensitizing dye A
Was added in an amount of 7.5 × 10 ^-4 mole per mole of silver, and the amount of tellurium sensitizer B was changed in an amount of 1.1 × 10 ^-4 mole per mole of silver.
2-heptyl-5-mercapto-1,3,4-triazole with silver 1
Spectral sensitization in the same manner except for changing the 3.3 × 10 ^-3 mol as Emulsion 1 moles, chemical sensitization and 5-methyl-2-mercapto Ben Uz imidazole, 1-phenyl-2-heptyl-5 Mercapto-1,3,4-triazole was added to obtain a silver halide emulsion 2. Emulsion grains of the silver halide emulsion 2 were pure silver bromide cubic grains having an average equivalent sphere diameter of 0.080 μm and a coefficient of variation of equivalent sphere diameter of 20%.

<< Preparation of Silver Halide Emulsion 3 >> In the preparation of silver halide emulsion 1, the liquid temperature of 34 ° C. during grain formation was changed to 27 ° C.
Silver halide emulsion 3 was prepared in the same manner except that the above was changed. Further, as in the case of the silver halide emulsion 1, the precipitation /
Desalting / water washing / dispersion was performed. The addition amount of the solid dispersion of the spectral sensitizing dye A (aqueous gelatin solution) was 6 × 10 ⁻³ mol per mol of silver, and the addition amount of the tellurium sensitizer B was 5.2 × 10 ⁻⁴ per mol of silver.
A silver halide emulsion 3 was obtained in the same manner as in the emulsion 1, except that the mole was changed. The emulsion grains of the silver halide emulsion 3 were pure silver bromide cubic grains having an average sphere equivalent diameter of 0.038 μm and a coefficient of variation of the sphere equivalent diameter of 20%.

<< Preparation of mixed emulsion A for coating solution >> Silver halide emulsion 1 was 70% by weight, silver halide emulsion 2 was 15% by weight,
Silver halide emulsion 3 was dissolved at 15% by weight, and benzothiazolium iodide was dissolved in a 1% by weight aqueous solution at a concentration of 7 × per mole of silver.
10 ^-3 mol was added.

<< Preparation of Solid Fine Particle Dispersion of Reducing Agent >> As a reducing agent, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane 10
kg and 10 kg of a 20% by weight aqueous solution of a modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval MP203) were added with 16 kg of water and mixed well to form a slurry. This slurry was sent by a diaphragm pump, and was fed for 3 hours by a horizontal sand mill (UVM-2, manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm.
After dispersing for 0 minute, 0.2 g of benzoisothiazolinone sodium salt and water were added to adjust the concentration of the reducing agent to 25% by weight to obtain a solid fine particle dispersion of the reducing agent. The reducing agent particles contained in the dispersion thus obtained had a median diameter of 0.42 μm and a maximum particle diameter of 2.0 μm or less.
The obtained dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Phosphoryl Compound Dispersion >> Triphenylphosphine oxide 1k was used as a phosphoryl compound.
g of water and 1.6 kg of water were added to 1 kg of a 20% by weight aqueous solution of a modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval MP203) and mixed well to form a slurry. The slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2, manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours and 30 minutes, and then sodium bezoisothiazolinone was used. The concentration of the phosphoryl compound was 25 by adding 0.2 salt and water.
% By weight to obtain a solid fine particle dispersion of a phosphoryl compound. The phosphoryl compound particles contained in the dispersion thus obtained had a median diameter of 0.45 μm and a maximum particle diameter of 2.0 μm or less. The resulting dispersion has a pore size of 1.
Filtration was performed with a 0.0 μm polypropylene filter to remove foreign substances such as dust, and stored.

<< Preparation of 25% by weight dispersion of organic polyhalogen compound-2 >> Similar to 20% by weight dispersion of organic polyhalogen compound-1, except that 5 kg of tribromomethylnaphthyl sulfone was used instead of tribromomethyl ( 4- (2,4,
5 kg of 6-trimethylphenylsulfonyl) phenyl) sulfone was dispersed and the organic polyhalogen compound was dispersed in 2 kg.
It was diluted to 5% by weight and filtered. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained have a median diameter of 0.38 μm and a maximum particle size of
It was 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of 30% by weight dispersion of organic polyhalogen compound-3 >> Similar to 20% by weight dispersion of organic polyhalogen compound-1, except that 5 kg of tribromomethylnaphthyl sulfone was used instead of tribromomethylphenyl sulfone Sulfone 5
5 kg of a 20% by weight aqueous solution of MP203 was dispersed in 5 kg, diluted with the organic polyhalogen compound so as to have a concentration of 30% by weight, and filtered. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained had a median diameter of 0.41 μm and a maximum particle diameter of 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored. After storage, it was stored at 10 ° C or less until use.

<< Preparation of Coating Solution for Image Forming Layer (Photosensitive Layer) >>
1.1 g of a 20% by weight aqueous dispersion of the pigment obtained above, 103 g of a silver salt of an organic acid, polyvinyl alcohol PVA-205 (Kuraray Co., Ltd.)
5 g of a 20% by weight aqueous solution of
g, 25 wt% phosphoryl compound dispersion 9.4 g, organic polyhalogen compound dispersion-1, -2, -3 in a total amount of 5: 1: 3 (weight ratio) of 1
6.3 g, mercapto compound 10% dispersion 6.2 g, ultrafiltration (U
F) 106 g of purified and pH adjusted SBR latex 40% by weight,
18 ml of a 5% by weight solution of a phthalazine compound was added, and 10 g of the silver halide mixed emulsion A was mixed well to prepare a coating solution for the image forming layer. The solution was directly sent to a coating die at 70 ml / m ^2. And used for coating.

<< Preparation of Photothermographic Material >> A photothermographic material sample 202 was prepared in the same manner as in Example 1 except that the above-mentioned materials were used. Sample 202 prepared as described above
In the above, the type and amount of the reducing agent and the amount of the phosphoryl compound used were changed as shown in Table 2, and the sample 201,
203 to 218 were produced. Further, the types and amounts of the reducing agent and the phosphoryl compound were changed as shown in Table 3, and samples 301 to 316 were produced. When preparing a sample using a reducing agent different from sample 202, the 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5 It was prepared using a new reducing agent instead of 5-trimethylhexane. Evaluation of image preservation is
The photosensitive material after the heat development is stored at 60 ° C. and a relative humidity of 50% for one day, and the density change ΔDm of the white background before and after the storage.
in was measured. The results are shown in Tables 2 and 3.

<< Evaluation of Photo Performance >> Fuji Medical Dry Laser Imager FM-DP L (Max. 60 mW (IIIB)
The photographic material was exposed and thermally developed (about 120 ° C.) with an output of 660 nm semiconductor laser, and the obtained image was evaluated with a densitometer. The results are shown in Tables 2 and 3.

[0182]

[Table 2]

[0183]

[Table 3]

As is clear from Table 2, by using a compound having a phosphoryl group in the molecule in combination with the reducing agent of the general formula (I), the development density (Dmax) was hardly reduced, and Fog after development (Dmin)
Can be suppressed, and the rise of Dmin after image storage can be significantly reduced. (I-3) and (I
-4) is highly active, and as shown in Table 2, the amount used can be significantly reduced. Such a highly active reducing agent has large fog and poor image stability after processing.However, by using a phosphoryl compound according to the present invention, fog is suppressed and simultaneously image stability after processing is reduced. It can be greatly improved. Table 3 also shows that the combination of the reducing agent and the phosphoryl compound is effective for suppressing fog and improving image storability.

Example 3 The structure of the compound used in Example 3 is shown below.

Embedded image

[0186]

Embedded image

[0187]

Embedded image

<< Preparation of PET Support >> Using terephthalic acid and ethylene glycol, the intrinsic viscosity IV
= 0.66 (phenol / tetrachloroethane = 6/4
(Measured at 25 ° C. in (weight ratio)). This was pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, and quenched to prepare an unstretched film having a thickness of 120 μm after heat setting. This was longitudinally stretched 3.3 times using rolls having different peripheral speeds, and then horizontally stretched 4.5 times using a tenter.
The temperatures at this time were 110 ° C. and 130 ° C., respectively. Thereafter, heat set was performed at 240 ° C. for 20 seconds, and relaxed 4% in the lateral direction at the same temperature. Then, after slitting the chuck part of the tenter, knurling is performed on both ends,
Wind at 4.8 kg / cm ² , width 2.4m, length 35
A roll-shaped PET support having a thickness of 00 m and a thickness of 120 μm was prepared.

<< Undercoating >> On both sides of the PET support obtained above, an undercoating layer (a) and an undercoating layer (b) having the following compositions
Were sequentially applied and dried at 180 ° C. for 4 minutes. The thickness of the undercoat layer (a) after drying was 2.0 μm. (1) Composition of undercoat layer (a) Polymer latex (A) Solid content of 3.0 g / m ² (core-shell type polymer latex having 90% by weight of core and 10% by weight of shell) Core: vinylidene chloride / methyl acrylate / Methyl methacrylate / acrylonitrile / acrylic acid = 93/3/3 / 0.9 / 0.1 (% by weight) Shell part: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 88/3/3/3 / 3 (weight%) weight average molecular weight 38000) 2,4-dichloro-6-hydroxy-S-triazine 23 mg / m ² matting agent 1.5 mg / m ² (polystyrene; average particle diameter 2.4 μm) (2) Undercoat layer (B) Composition Deionized gelatin 50 mg / m ² (Ca ²⁺ content 0.6 ppm; jelly strength 230g)

<< Formation of Back Layer >> The following conductive layer and protective layer are sequentially coated on one side of the two-layer undercoated PET support obtained above, and dried at 180 ° C. for 4 minutes, respectively. A back layer was formed. (1) Composition of conductive layer Jurimar ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.) 96 mg / m ² alkali-treated gelatin (molecular weight: about 10,000, Ca ²⁺ content 30 ppm) 42 mg / m ² deionized gelatin (Ca ²⁺ content) 0.6 mg) 8 mg / m ² Compound G 0.2 mg / m ² Polyoxyethylene phenyl ether 10 mg / m ² Sumitex Resin M-3 18 mg / m ² (water-soluble melamine compound, manufactured by Sumitomo Chemical Co., Ltd.) Dye A Coating amount to give an optical density of 783 nm of 1.2 SnO ₂ / Sb 160 mg / m ² (9/1 weight ratio, needle-like fine particles, major axis / minor axis = 20-30, manufactured by Ishihara Sangyo Co., Ltd.) Methyl methacrylate, average particle size 5 μm) 7 mg / m ²

(2) Composition of protective layer Polymer latex (a) 1000 mg / m ² as solid content (methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 59/9/26/5/1 (% By weight of copolymer)) Polystyrene sulfonate (molecular weight: 1,000 to 5,000) 2.6 mg / m ² cellosol 524 (Chukyo Yushi Co., Ltd.) 25 mg / m ² Sumitex Resin M-3 218 mg / m ² (water soluble) Melamine compound, manufactured by Sumitomo Chemical Co., Ltd.)

<< Transportation Heat Treatment >> (1) Heat Treatment The undercoated and backed PET support obtained above was put into a heat treatment zone having a total length of 200 m set at 160 ° C., a tension of 3 kg / cm ² , and a transfer speed of 20 m. / Min and heat treated. (2) Post-heat treatment After the heat treatment, post-heat treatment was performed by passing through a zone at 40 ° C for 15 seconds, and the film was wound. The winding tension at this time is 1
It was 0 kg / cm ² .

<< Preparation of Image Forming Layer Coating Solution >> (1) Preparation of Organic Acid Silver Dispersion Behenic acid manufactured by Henkel (product name: Edenor C22-85R)
87.6 g, distilled water 423 ml, 5N-NaOH aqueous solution 49.2 ml, and tert-butyl alcohol 120 m
were mixed and reacted at 75 ° C. for 1 hour with stirring to obtain a sodium behenate solution. Separately, 206.2 ml of an aqueous solution containing 40.4 g of silver nitrate was prepared and kept at 10 ° C.
A reaction vessel containing 635 ml of distilled water and 30 ml of tert-butyl alcohol was kept at 30 ° C., and the above-mentioned sodium behenate solution and silver nitrate aqueous solution were added at a constant flow rate over 62 minutes, 10 seconds and 60 minutes, respectively, with stirring. At this time, only the aqueous silver nitrate solution was added for 7 minutes and 20 seconds from the start of the addition of the aqueous silver nitrate solution, and then the addition of the sodium behenate solution was started. Only the solution was added. At this time, the temperature in the reaction vessel was 30 ° C.
And the solution temperature was controlled so as not to rise. Further, the piping of the addition system of the sodium behenate solution was kept warm by steam tracing, and the amount of steam was controlled so that the liquid temperature at the outlet at the tip of the addition nozzle became 75 ° C. The piping of the silver nitrate aqueous solution addition system was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution. After completion of the addition of the sodium behenate solution, the mixture is left to stir at the same temperature for 20 minutes,
The temperature was lowered to 25 ° C. 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. The solid thus obtained was stored as a wet cake without drying.

The morphology of the obtained silver behenate grains was evaluated by electron microscopic photographing.
It was a flaky crystal having a particle size of 2 μm, an average particle thickness of 0.14 μm, and a coefficient of variation of the average equivalent sphere diameter of 15%. Dry solid content 10
For a wet cake equivalent to 0 g, 7.4 g of polyvinyl alcohol (trade name: PVA-217, average degree of polymerization: about 1700)
And water were added to make the total amount 385 g, and the mixture was pre-dispersed with a homomixer. Next, the pre-dispersed stock solution is dispersed in a dispersing machine (trade name: Microfluidizer M-110S-
EH, Microfluidics International
The pressure of the G10Z interaction chamber manufactured by Corporation was adjusted to 1750 kg / cm ² ,
After three treatments, a silver behenate dispersion was obtained as a silver salt of an organic acid. The cooling operation was performed by installing a coiled heat exchanger before and after the interaction chamber, and adjusting the temperature of the refrigerant to a desired dispersion temperature. The silver behenate particles contained in the silver behenate dispersion thus obtained had a volume-weighted average diameter of 0.52 μm and a coefficient of variation of 15%. The particle size is measured using MasterSize from Malvern Instruments Ltd.
Performed at rX. When evaluated by electron microscopy,
The ratio of the long side to the short side was 1.5, the grain thickness was 0.14 μm, and the average aspect ratio (the ratio of the circle equivalent diameter of the projected area of the grain to the grain thickness) was 5.1.

(2) Preparation of photosensitive silver halide emulsion In 700 ml of water, alkali-treated gelatin (containing calcium) was added.
11 g, potassium bromide 30 m
g and sodium benzenethiosulfonate 10 mg
After dissolving and adjusting the pH to 5.0 at a temperature of 40 ° C.,
159 ml of an aqueous solution containing 18.6 g of silver and potassium bromide
1 mol / liter, (NH_Four)_TwoRhCl _Five(H_TwoO) 5
× 10^-6Mol / l and K_ThreeIrCl₆Is 2 × 10
^-FiveThe pAg of the aqueous solution containing mol / liter is maintained at 7.7.
6 minutes and 30 seconds by control double jet method
And added. Subsequently, an aqueous solution containing 55.5 g of silver nitrate
476 ml of liquid, 1 mol / l of potassium bromide and
K_ThreeIrCl₆Is 2 × 10^-FiveWith an aqueous solution containing moles / liter
While controlling pAg at 7.7.
It was added over a period of 28 minutes and 30 seconds by the wet method. Then pH
, And the mixture was subjected to desalination by coagulation and sedimentation.
17 g, and low molecular weight gelatin having an average molecular weight of 15,000
(Calculated as a calcium content of 20 ppm or less)
The pH was adjusted to 5.9 and pAg to 8.0. Grains obtained
Have an average grain size of 0.08 μm and a projected area variation coefficient of 9
%, (100) face ratio of 90%. Get
The photosensitive silver halide grains thus obtained are heated to 60 ° C.
Sodium thiosulfonate at 76 μm
3 minutes later, 71 μmol of triethylthiourea was added.
And aged for 100 minutes. Then, 4-hydroxy
-6-methyl-1,3,3a, 7-tetrazaindene
5 × 10^-FourMol was added, and the temperature was lowered to 40 ° C. Temperature to 40 ° C
And sensitizing dye A is used per mole of photosensitive silver halide.
12.8 × 10^-FourMole, photosensitive halogenated compound B
6.4 × 10 per mole of silver^-3Add mole while stirring
After 20 minutes, the mixture is rapidly cooled to 30 ° C.
A silver emulsion was prepared.

(3) Preparation of solid fine particle dispersion of ultra-high contrast agent 2.5 g of polyvinyl alcohol (Kuraray PVA-217) and 87.5 g of water were added to 10 g of the ultra-high contrast agent (nucleating agent A). The mixture was stirred well and left as a slurry for 3 hours.
Thereafter, 240 g of 0.5 mm zirconia beads were put into the vessel together with the slurry, and dispersed for 10 hours with a dispersing machine (1 / 4G sand grinder mill: manufactured by Imex Co., Ltd.) to obtain a solid fine particle dispersion of a super-high contrast agent. Prepared. As for the particle diameter, 80% by weight of the particles was 0.1 to 1.0 μm, and the average particle diameter was 0.5 μm.

(4) Preparation of Solid Fine Particle Dispersion of Reducing Agent 25 g of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane was mixed with MP manufactured by Kuraray Co., Ltd. 25 g of a 20% by weight aqueous solution of polymer MP-203 and 0.1 g of Safinol 104E manufactured by Nissin Chemical Co., Ltd.
g, 2 g of methanol and 48 ml of water were added, stirred well, and left as a slurry for 3 hours. Then 1mm
Of zirconia beads was placed in a vessel together with the slurry, and dispersed with a dispersing machine (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) for 3 hours to prepare a solid fine particle dispersion of a reducing agent. As for the particle diameter, 80% by weight of the particles was 0.3 to 1.0 μm.

(5) Preparation of polyhalogen compound dispersion A dispersion of polyhalogen compound-A (30 g) was added to M
4 g of P-polymer MP-203, 0.25 g of compound C and 66 g of water were added, and the mixture was stirred well to form a slurry.
200 g of 0.5 mm zirconia silicate beads were put into a vessel together with the slurry, and dispersed for 5 hours with a dispersing machine (1 / 16G sand grinder mill: manufactured by Imex Co., Ltd.) to obtain a polyhalogen compound dispersion-A dispersion. Prepared. As for the particle diameter, 80% by weight of the particles are 0.3 to 1.0 μm.
Met. For polyhalogen compound-B, a solid fine particle dispersion was prepared in the same manner as for polyhalogen compound-A, and had the same particle diameter.

(6) Preparation of dispersion of solid fine particles of zinc compound To 30 g of compound Z was added MP-2 of MP polymer manufactured by Kuraray Co., Ltd.
3g and 87ml of water were added, and the mixture was stirred well and left as a slurry for 3 hours. Thereafter, the same operation as in the preparation of the solid fine particle dispersion of the reducing agent in the above (4) was performed to prepare a solid fine particle dispersion of a zinc compound (compound Z). As for the particle diameter, 80% by weight of the particles was 0.3 to 1.0 μm.

(7) Preparation of Image Forming Layer Coating Solution The following components were added to 1 mol of silver in the organic acid silver (silver behenate) dispersion prepared in the above (1), and water was added. To prepare a coating solution for the image forming layer. Photosensitive silver halide emulsion obtained in (2) 0.05 mol as Ag amount Solid fine particle dispersion of nucleating agent obtained in (3) 17.1 g as solid content Solid fine particles of reducing agent obtained in (4) Dispersion 166 g of solid content as polyhalogen compound dispersion obtained in (5) -A 0.06 mol as solid content Polyhalogen compound dispersion as obtained in (5) -B 0.02 mol as solid content (6 ) Solid dispersion of zinc compound obtained in step 1) Solid content: 10.5 g Binder: Luckstar 3307B Solid content: 470 g (manufactured by Dainippon Ink and Chemicals, Inc .; glass transition temperature of 17 ° C. with SBR latex) ethanethiosulfonic acid Sodium 2.2 mmol 5-methylbenzotriazole 1.36 g Polyvinyl alcohol (Kuraray Co., Ltd. PVA-235) 12.1 g 6-isopropylphthalazine 16.5 g The coating amount of optical density of 0.3 of sodium belt dihydrogen phosphate dihydrate 0.37g Dye A 783 nm (0.50 g as a guide)

<< Preparation of Coating Solution for Protective Layer on Image Forming Surface >> (1) Preparation of Coating Solution for Protective Layer on Image Forming Surface (a) Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate /
Acrylic acid = 58.9 / 8.6 / 25.4 / 5.1 / 2
(Weight%) of a polymer latex solution having a particle diameter of 120 nm (copolymer having a glass transition temperature of 57 ° C. and a solid content of 2)
Water was added to 956 g of 1.5% by weight, containing Compound D as a film-forming auxiliary (15% by weight based on the solid content of the latex),
1.62 g of compound E, 3.15 g of compound S, 1.98 g of matting agent (polystyrene particles, average particle diameter 7 μm, coefficient of variation of average particle diameter 8%) and polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA-235) 23.6 g) and water were further added to prepare a coating solution for the protective layer (a) on the image forming surface.

(2) Protective layer for image forming surface (b) Preparation of coating solution Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate /
Acrylic acid = 58.9 / 8.6 / 25.4 / 5.1 / 2
(Weight%) of a polymer latex solution having a particle diameter of 70 nm (copolymer, glass transition temperature: 54 ° C, solid content: 21.
5% by weight, compound D represented by (6-1) as a film-forming aid
15% by weight based on the solid content of the latex) 630
g water and add carnava wax (Chukyo Yushi Co., Ltd.)
6.30 g of a 30% by weight solution of Cellosol 524). Further, the compound E described in the above (1) was added to 0.72
g and 7.95 g of compound F, and 0.9 g of compound S was added.
0 g, matting agent (polystyrene particles, average particle size 7 μm)
1.18 g and polyvinyl alcohol (Kuraray Co., Ltd.)
8.30 g, PVA-235) and water.
A coating solution for the protective layer (b) on the image forming surface was prepared.

<< Preparation of Photothermographic Material >> The opposite side of the backing-coated surface of the PET support subjected to the heat treatment for transportation obtained above, that is, the undercoat layer (a) and the undercoat layer (b) are applied. Then, the coating solution for the image forming layer was coated with a coating silver amount of 1.6.
g / m ^2, and a coating solution for the protective layer (a) on the image forming surface was simultaneously coated thereon so that the solid content of the polymer latex was 1.31 g / m ² . . Thereafter, the coating solution for the protective layer (b) on the image forming surface was coated thereon, and the solid content of the polymer latex was 3.02 g.
/ M ² to produce a photothermographic material. The film surface pH on the image forming side of the obtained photothermographic material was 4.9, the Beck smoothness was 660 seconds, the film surface pH on the opposite side was 5.9, and the Beck smoothness was 560 seconds. Was.

The phenolic reducing agent (compound of the general formula (I)) and the compounds of the general formulas (II), (III), (IV), (V) and Samples were prepared by changing the amount of coating in the same manner as in Example 1, and the image storability was evaluated.

<< Evaluation >> (1) Exposure Processing The photothermographic material was exposed to a beam having a beam diameter (FW of 1/2 of the beam intensity).
HM) 12.56 μm, laser output 50 mW, output wave
Single channel equipped with 783nm long semiconductor laser
Use a cylindrical inner surface laser exposure device to rotate the mirror.
Change the exposure time and output value by changing the number of turns.
The exposure amount is adjusted by ^-8Exposure for seconds
Was. The overlap coefficient at this time was 0.449.
Was. (2) Heat development treatment The exposed heat-developable photosensitive material obtained in the above (1) is
The heat development processing was performed using the heat developing machine shown in FIG. Immediately
The surface material of the roller in the heat development processing part is silicon rubber.
Teflon (registered trademark) non-woven fabric is used for the
At a linear speed of 20 mm / sec, pre-heating unit 90-110 ° C
15 seconds (The drive systems of the preheating unit and the heat development processing unit are independent
And the speed difference with the heat development section is set to -0.5% to -1%)
Developing part at 120 ° C. for 20 seconds, slow cooling part at 15 seconds
Was done. Note that the temperature accuracy in the width direction is ± 1 ° C.
Was.

(3) Evaluation of Storage Property for Dark Thermal Image The exposed and developed photothermographic material was evaluated in the same manner as in Example 1. As a result, it is apparent that the photothermographic material of the present invention exhibits excellent performance as compared with the comparative example, and that the photothermographic material having a super-high contrast has the same excellent image storability as in Example 1. found.

Example 4 14 kinds of photothermographic materials were prepared by replacing the compound (II-2) of the sample 102 of Example 1 with an equimolar amount of the compound shown in Table 4. For each photothermographic material, the image storability (性
Dmin). Table 4 shows the results.

[0208]

[Table 4]

When a phosphoryl compound having a phenyl group having a substituent at the ortho position was used, excellent image storability was exhibited.

[0210]

EFFECTS OF THE INVENTION A phenolic reducing agent and a compound having a hydrogen bond formation rate constant Kf of 20 to 4000 or a compound of the general formula (II) (III) (IV) (V) or a compound having a phosphoryl group To provide a photothermographic material capable of giving a sufficient image density within a realistic reaction temperature and reaction time by being used in combination and sufficiently suppressing coloring of a white background when stored in a dark place after development processing. Is now possible.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a configuration of a heat developing machine used in an embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Thermal development image recording material 11 Carry-in roller 12 Carry-out roller 13 Roller 14 Smooth surface 15 Heater 16 Guide plate A Preheating part B Thermal development part C Slow cooling part

Claims (8)

[Claims] 1. A photosensitive halide on one surface of a support.
Silver, non-photosensitive organic silver salts, reducing agents and
In the photothermographic material containing indder, the reducing agent
And at least one of the phenolic compounds
Less compounds satisfying at least one of the conditions
Characterized by containing a combination of two types
Image-sensitive material. A: Hydrogen bond formation rate constant Kf is 20 to 4000
B: The following general formula (II), (III), (IV) or (V)
Or has a phosphoryl group in the molecule.
To do(In the general formula (II), R^{twenty one}And R^{twenty two}Are independent
Represents an alkyl group; ^{twenty three}Represents an alkyl group or an aryl group.
Or a heterocyclic group. R^{twenty one}, R^{twenty two}And R^{twenty three}Selected from
Two or more may be connected to each other to form a ring
No. In the general formula (III), R³¹And R³²Are each
Independently represents an alkyl group, an aryl group or a heterocyclic group.
R³¹And R³²May be connected to each other to form a ring. one
In the general formula (IV), R⁴¹And R⁴²Are independent
Represents an alkyl group, an aryl group or a heterocyclic group. R⁴³Is
Alkyl group, aryl group, heterocyclic group or -N (R⁴⁴) (R
⁴⁵). R⁴⁴And R⁴⁵Are each independently alkyl
Group, an aryl group or a heterocyclic group. R⁴¹, R⁴²,
R⁴³, R⁴⁴And R⁴⁵Two or more selected from
They may be linked together to form a ring. General formula (V)
And R⁵¹, R⁵², R⁵³, R⁵⁴And R⁵⁵Are independently
Represents a hydrogen atom or a substituent. R⁵¹, R⁵², R⁵³, R⁵⁴
And R⁵⁵Two or more selected from
To form a ring. ) 2. The photothermographic material according to claim 1, wherein the phenol compound is an o-polyphenol compound. 3. The photothermographic material according to claim 2, wherein the o-polyphenol compound is a compound represented by the following general formula (I). Embedded image (Wherein, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom or a group that can be substituted on a benzene ring, and L represents an —S— group Or a -CHR ⁹ -group,
R ⁹ represents a hydrogen atom or an alkyl group. ) 4. A compound represented by the general formula (I):
R ² , R ⁴ , R ⁵ and R ⁷ are hydrogen atoms, R ¹ and R ⁸ are each independently an alkyl group, R ³ and R ⁶
There are each independently an alkyl group, L is -CHR ⁹ -
The photothermographic material according to claim 3, which is: 5. The photothermographic material according to claim 4, wherein R ¹ and R ⁸ are each independently a secondary or tertiary alkyl group. 6. The hydrogen bond formation rate constant Kf is 70 to 6.
The photothermographic material according to any one of claims 1 to 5, wherein the number is 4,000. 7. The heat according to claim 2, wherein the phenol compound is an o-polyphenol compound and is contained in combination with at least one compound having a phosphoryl group in the molecule. Developed photosensitive material. 8. The photothermographic material according to claim 1, wherein the compound having a phosphoryl group in the molecule is a compound represented by the following general formula (VI). Embedded image (In the formula, R ⁶¹ , R ⁶² and R ⁶³ each independently represent an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group.)