JP2000010232A - Heat developable photographic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photographic material which shows good silver tone and enough image density by heat development by incorporating a reducible silver salt, a reducing agent, a binder and specified compds. SOLUTION: This photographic material contains a reducible silver salt, a reducing agent, a binder, at least one kind of compd. expressed by formula I and at least one kind of compd. expressed by formula II. In the formula I, R11 to R16 are each independently hydrogen atom or a univalent substituent, and these substituents may be bonded to each other to form rings. In the formula II, Z represents a group of nonmetallic atoms necessary to form a heteroaromatic ring including at least one oxygen atom or sulfur atom, and R21 and R22 are each independently hydrogen atom or a univalent substituent. The compds. expressed by the formula I may be added together to one layer or separately to different layers. The compds. expressed by the formula II may be added to the photosensitive layer which forms an image forming layer or to a non-photosensitive layer such as a protective layer on the side where the image forming layer is present.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat-developable photographic material using an organic silver salt image forming medium. More specifically, the present invention relates to a heat-developable photographic material containing silver halide as a photocatalyst and having a good silver tone and high image density for forming an image by heat development.

[0002]

2. Description of the Related Art There are many known photosensitive materials having a photosensitive layer on a support and forming an image by exposing the image. Among them, a technique for forming an image by thermal development is a system that can simplify environmental preservation and image forming means.

[0003] In recent years, there has been a strong demand in the medical field to reduce the amount of processing waste liquid from the viewpoint of environmental conservation and space saving. Thus, photosensitive thermal development for medical diagnostics and photographic technology, which can be efficiently exposed by a laser imagesetter or laser imager and can form a sharp black image with high resolution and sharpness There is a need for materials technology. These photosensitive heat-developable materials can eliminate the use of solution-based processing chemicals, and can provide customers with a simpler heat-development processing system that does not damage the environment.

[0004] A method of forming an image by thermal development is described in, for example, US Pat.
And D. Morgan and B.A. Shely
"Thermal Processed Silver System (Thermally
Processed Silver Systems ”(Imaging Processesan and Materials)
d Materials) Neblette 8th edition, Sturge,
V. Walworth, A .; Shep
p) Compilation, page 2, 1969).

[0005] Such photosensitive materials include a reducible non-photosensitive silver source (eg, an organic silver salt), a catalytically active amount of a photocatalyst (eg, silver halide), and a silver reducing agent, usually in an organic binder matrix. It is contained in a dispersed state.
The photosensitive material is stable at room temperature, but after exposure to high temperature (for example,
When heated to 80 ° C. or higher, silver is generated through an oxidation-reduction reaction between a reducible silver source (functioning as an oxidizing agent) and a reducing agent. This oxidation-reduction reaction is promoted by the catalytic action of the latent image generated by the exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image.

In the above-mentioned heat-developable photographic material, an additive generally known as a "toning agent" is used for the purpose of obtaining an image having a high maximum density, improving the color tone of developed silver, and improving developability. Used as needed. In the photothermographic material utilizing an organic silver salt, a wide range of color toning agents are disclosed in JP-A-46-6077, JP-A-47-10282, JP-A-49-5019, and JP-A-49-502.
No. 0, No. 49-91215, No. 49-91215, No. 50-2524, No.
No. 50-32927, No. 50-67132, No. 50-67641, No. 50-11421
No. 7, No. 51-3223, No. 51-27923, No. 52-14788, No.
52-99813, 53-1020, 53-76020, 54-15652
No. 4, 54-156525, 61-183642, JP-A-4-5684
No. 8, JP-B-49-10727, JP-B-54-20333, U.S. Pat.
No. 080,254, No. 3,446,648, No. 3,782,941, No. 4,123,282, No. 4,510,236, British Patent No. 138079
No. 5, Belgian Patent No. 841910 and the like.

Examples of known color toning agents include phthalazinones (for example, phthalazinone, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone and 2,3-dihydro-1. Phthalazine dione and phthalic acid derivatives (eg, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride), phthalazines (eg, phthalazine, 5- Methylphthalazine, 6-methylphthalazine, 5,7-dimethylphthalazine, 6-ethylphthalazine, 6-isopropylphthalazine, 6-i
-Butylphthalazine, 6-t-butylphthalazine, 4- (1
-Naphthyl) phthalazine, 6-acetylphthalazine, 6-
Chlorophthalazine, 5,7-dimethoxyphthalazine and 2,2
3-dihydrophthalazine, etc.), a combination of phthalazine and a phthalic acid derivative, a cyclic imide (for example, phthalimide,
N-hydroxyphthalimide, succinimide, pyrazolin-5-one, and quinazolinone, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione, naphthalimide, N-hydroxy- 1,8-naphthalimide), N- (aminomethyl)
Aryldicarboximides (e.g., (N, N-dimethylaminomethyl) phthalimide and N, N- (dimethylaminomethyl) -naphthalene-2,3-dicarboximide),
Quinazolinedione, benzoxazine or naphthoxazine derivatives, cobalt complexes (eg, cobalt hexamine trifluoroacetate), mercaptans (eg, 3-mercapto-1,2,4-triazole, 2,4-dimercaptopyrimidine, 3-mercapto -4,5-diphenyl-1,2,4-
Triazole and 2,5-dimercapto-1,3,4-thiadiazole), blocked pyrazoles, isothiuronium derivatives and certain photobleaching agents (e.g., N, N'-hexamethylenebis (1-carbamoyl-3,5- Dimethylpyrazole), 1,8- (3,6-diazaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzothiazole, 3-ethyl-5 [(3-ethyl-2-benzo Thiazolinylidene) -1-methylethylidene] -2-thio-2,4-oxazolidinedione), which not only functions as a color tone regulator but also as a source of halide ions for silver halide formation in situ Rhodium complexes (eg ammonium hexachlororhodate (III),
Rhodium bromide, rhodium nitrate and potassium hexachlororhodate (III), inorganic peroxides and persulfates (eg, ammonium disulfide) and hydrogen peroxide, benzoxazine-2,4-diones (eg, , 1,3-
Benzoxazine-2,4-dione, 8-methyl-1,3-benzoxazine-2,4-dione and 6-nitro-1,3-benzoxazine-2,4-dione), pyrimidine and asymmetric triazine (E.g., 2,4-dihydroxypyrimidine, 2-hydroxy-4-aminopyrimidine, etc.), azauracil,
And tetraazapentalene derivatives (for example, 3,6-dimercapto-1,4-diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene, and 1,4-di (o-chlorophenyl)- 3,6-
Dimercapto-1H, 4H-2,3a, 5,6a-tetraazapentalene) and the like.

[0008] These color toning agents are required to have not only good silver tone but also various performances such as sufficient image density, appropriate development temperature characteristics, development progress, and stability during storage. As preferred examples of the color tone agent, a combination of phthalazinone and a phthalic acid derivative, and a combination of phthalazine and a phthalic acid derivative have been conventionally selected.

Conventionally, most of heat-developable photographic materials are toluene,
A photosensitive layer was formed by applying a coating solution using an organic solvent such as methyl ethyl ketone or methanol as a solvent. The use of an organic solvent as a solvent may not only adversely affect the human body in the manufacturing process but also be disadvantageous in terms of cost due to recovery of the solvent and the like. Therefore, a method of forming a photosensitive layer using a coating solution of a water solvent that does not have such a concern has been considered. For example, Japanese Patent Application No. Hei 9-185724 discloses an example in which a polymer latex soluble or dispersible in an aqueous solvent is used as a binder.
JP-A-53-116144 discloses an example using gelatin as a binder, JP-A-50-151138 discloses an example using a polyvinyl alcohol as a binder, and JP-A-60-61747 discloses an example using gelatin as a binder. An example using polyvinyl alcohol in combination is described. As another example, JP-A-58-28737 describes an example of a photosensitive layer using water-soluble polyvinyl acetal as a binder.

Certainly, if such a binder is used, the photosensitive layer can be formed using a coating solution of an aqueous solvent, and the environmental and cost advantages are great. However,
When forming the photosensitive layer with a coating solution using an organic solvent as a solvent, a combination of the above-described color tone agents that gave a preferable silver tone was formed when the photosensitive layer was formed using an aqueous solvent coating solution. In some cases, such a problem as described above occurs, and its improvement has been an issue.

[0011] 1) Provided as a commercial product in heat-developable photographic materials for medical diagnostics and the like, in which the silver tone is brown or reddish upon thermal development, and particularly a clear black-blue silver tone is required. And 2) that sufficient image density cannot be obtained when thermal development is performed.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-developable photographic material having a good silver tone and sufficient image density when subjected to heat development.

[0013]

The above object has been achieved by the present invention described below. (1) (a) a reducible silver salt, (b) a reducing agent, (c)
A heat-developable photographic material comprising: a binder; (d) at least one compound represented by the following general formula (I); and (e) at least one compound represented by the following general formula (II).

[0014]

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[In the general formula (I), R ₁₁ , R ₁₂ , R ₁₃ , R
₁₄ , R ₁₅ and R ₁₆ each independently represent a hydrogen atom or 1
Represents a valent substituent, and these substituents may combine with each other to form a ring. ]

[0016]

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[In the general formula (II), Z represents a group of non-metallic atoms necessary for forming a heteroaromatic ring containing at least one oxygen atom or sulfur atom. R ₂₁ and R ₂₂ represent a hydrogen atom or a monovalent substituent. (2) The photothermographic material according to the above (1), which contains a photosensitive silver halide as a photocatalyst. (3) The photothermographic material according to the above (1) or (2), comprising at least one compound represented by the following general formula (III).

[0018]

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[In the formula, T represents a monovalent substituent, and k represents an integer of 0 or more and 4 or less. k = 0 represents all hydrogen atoms, and when k ≧ 2, a plurality of Ts may be the same or different, and may be bonded to each other to form a ring. M ₁ and M ₂ each represent a hydrogen atom or a cation. ]

[0020]

Embodiments of the present invention will be described below in detail. The heat-developable photographic material of the present invention, which forms an image by heat development, contains a reducible silver salt (preferably an organic silver salt), a reducing agent, and a binder. It is preferable that the photothermographic material contains silver halide. Such a heat-developable photographic material contains a compound represented by the general formula (I) and a compound represented by the general formula (II), and more preferably contains a compound represented by the general formula (III). By doing so, a heat-developable photographic material having good silver tone, high maximum density (Dmax) and sensitivity, low fog, and good coated surface quality can be obtained. On the other hand, when only the compound of the general formula (I) is used and the compound of the general formula (II) is not contained,
When a compound not included in the general formula (II) is contained, the silver tone is not sufficient. Further, when only the compound of the general formula (II) is used, Dmax and sensitivity decrease, and silver tone deteriorates. When a compound different from the general formula (I) such as phthalazinone or pyridazine is used instead of the compound of the general formula (I), Dmax and sensitivity are reduced, and silver tone is deteriorated.

The general formula (I) will be described in detail. R
₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ each independently represent a hydrogen atom or a monovalent substituent, and these substituents may combine with each other to form a ring. As the substituent, for example, an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 12 carbon atoms)
-8, for example, methyl, ethyl, n-propyl, i
so-propyl, n-butyl, sec-butyl, iso
-Butyl, tert-butyl, n-pentyl, tert
-Pentyl, n-hexyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, benzyl and the like. ),
An alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 8 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, and 3-pentenyl); An alkynyl group (preferably having 2 to 20, more preferably 2 to 12, and particularly preferably 2 to 8; examples thereof include propargyl and 3-pentynyl); and an aryl group (preferably having 6 to 30 carbon atoms). More preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, for example, phenyl, p-methylphenyl, naphthyl, etc.), amino group (preferably 0 to 20 carbon atoms, more preferably Is carbon number 0
10 to 10, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino, dibenzylamino and the like. ), An alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, for example, methoxy, ethoxy, isopropoxy, butoxy and the like), and aryl. An oxy group (preferably having 6 to 20 carbon atoms, more preferably having 6 to 16 carbon atoms, particularly preferably having 6 to 12 carbon atoms, for example, phenyloxy,
2-naphthyloxy and the like. ), An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 carbon atom)
To 16, particularly preferably 1 to 12 carbon atoms, for example, acetyl, benzoyl, formyl, pivaloyl and the like. ), An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably having 2 to 12 carbon atoms, for example, methoxycarbonyl, ethoxycarbonyl and the like.), Aryloxycarbonyl Group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, particularly preferably having 7 carbon atoms)
To 10, for example, phenyloxycarbonyl and the like. ), An acyloxy group (preferably having 2 carbon atoms)
-20, more preferably 2-16 carbon atoms, particularly preferably 2-10 carbon atoms, such as acetoxy and benzoyloxy. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 1 carbon atoms)
6, particularly preferably having 2 to 10 carbon atoms, for example, acetylamino, benzoylamino and the like. ),
Alkoxycarbonylamino group (preferably having 2 to 2 carbon atoms)
20, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino. ), An aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, particularly preferably having 7 to 12 carbon atoms,
For example, phenyloxycarbonylamino and the like can be mentioned. ), A sulfonylamino group (preferably having 1 to 2 carbon atoms)
0, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, methanesulfonylamino,
Benzenesulfonylamino and the like. ), A sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, for example, sulfamoyl, methylsulfamoyl,
Dimethylsulfamoyl, phenylsulfamoyl and the like can be mentioned. ), A carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, and examples thereof include carbamoyl, methylcarbamoyl, diethylcarbamoyl, and phenylcarbamoyl). An alkylthio group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 1 carbon atoms)
6, particularly preferably 1 to 12 carbon atoms, for example, methylthio, ethylthio and the like. ), An arylthio group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably having 6 to 12 carbon atoms, such as phenylthio, etc.), and a sulfonyl group (preferably having 1 carbon atom). -20, more preferably 1 carbon atom
To 16, particularly preferably 1 to 12 carbon atoms, such as mesyl and tosyl. ), A sulfinyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms, such as methanesulfinyl and benzenesulfinyl), and a ureido group (preferably). Is carbon number 1-2
It has 0, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, and examples thereof include ureido, methylureide, and phenylureide. ), A phosphoric amide group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms,
For example, diethylphosphoramide, phenylphosphoramide and the like can be mentioned. ), A hydroxy group, a mercapto group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom,
Iodine atom), cyano group, sulfo group, carboxyl group,
Examples include a nitro group, a hydroxamic acid group, a sulfino group, a hydrazino group, and a heterocyclic group (for example, imidazolyl, pyridyl, furyl, piperidyl, morpholino, thienyl and the like). These substituents may be further substituted, and the substituent capable of forming a salt may form a salt. The ring R ₁₁ to R ₁₆ is formed by bonding dioxolen ring, there is a benzene ring or the like.

R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆
Is preferably a hydrogen atom, an alkyl group, an aryl group, a halogen atom, more preferably a hydrogen atom,
An alkyl group and an aryl group are particularly preferable, and a hydrogen atom and an alkyl group are particularly preferable.

The compound represented by the general formula (I) of the present invention is, for example, RGElderField, "Heterocyclic Compound
s ", John Wiley and Sons, Vol. 1-9, (1950-1967) and ARK
atritzky, "Comprehensive Heterocyclic Chemistry", Pe
Those skilled in the art can easily synthesize them by known methods described in rgamon Press, (1984) and the like.

Specific examples of the compound represented by formula (I) are shown below, but the present invention is not limited thereto.

[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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The compound represented by the general formula (I) of the present invention may be added to the image forming layer side of the heat-developable photographic material, whether it is a photosensitive layer which can be an image forming layer or a non-photosensitive layer such as a protective layer. Can be. The compounds represented by the general formula (I) of the present invention may be added in the same layer, may be added in divided layers, or may be added by changing the amount ratio for each layer. it can.

The compound represented by the general formula (I) of the present invention varies depending on the desired purpose, but is expressed in an amount of 10 ^-4 to 1 mol / Ag, preferably 10 ^{-3 to} 0.3 mol, per mol of Ag. / Ag,
It is more preferable to add 10 ^{−3 to} 0.1 mol / Ag.

The compound represented by the general formula (I) of the present invention may be added by any method such as a solution, a powder and a dispersion of solid fine particles. Dispersion of solid fine particles can be performed by a known micronizing means (for example, ball mill, vibrating ball mill, side mill,
Colloid mill, jet mill, roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

Next, the compound represented by formula (II) will be described. Z represents a nonmetallic atom group necessary for forming a heteroaromatic ring containing at least one oxygen atom or sulfur atom, and the heteroaromatic ring containing at least one oxygen atom or sulfur atom further has a substituent. May be. The definition of the aromatic ring here is, for example, 1988
iley &Sons' J.I. A by March
advanced Organic Chemistr
y, Chapter 2. R ₂₁ and R
₂₂ represents a hydrogen atom or a monovalent substituent. The heteroaromatic ring formed by Z and containing at least one oxygen atom or sulfur atom is preferably a 5- or 6-membered ring. Preferred examples include a furan ring, a thiophene ring, an oxazole ring, an isoxazole ring, a thiazole ring, a thiadiazole ring, an oxadiazole ring, and the like, and a furan ring or a thiophene ring is more preferable. Is particularly preferred.
The substituents on the heteroaromatic ring containing at least one oxygen or sulfur atom formed by R ₂₁ , R ₂₂ and Z may be bonded to each other to form a ring.

The monovalent substituent represented by R ₂₁ and R ₂₂ and the substituent on the heteroaromatic ring containing at least one oxygen or sulfur atom formed by Z may be the same or different, For example, an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, i
so-butyl, tert-butyl, n-octyl, n-
Decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl and the like can be mentioned. ), An alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, and examples thereof include vinyl, allyl, 2-butenyl, and 3-pentenyl. ), An alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 2 carbon atoms).
To 8, for example, propargyl, 3-pentynyl and the like. ), An aryl group (preferably having 6 to 3 carbon atoms)
It has 0, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include phenyl, p-methylphenyl, and naphthyl. ), An amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 1 carbon atoms)
0, particularly preferably 0 to 6 carbon atoms, such as amino, methylamino, dimethylamino, diethylamino,
Dibenzylamino and the like. ), An alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 carbon atom)
-12, particularly preferably 1-8 carbon atoms, for example, methoxy, ethoxy, butoxy and the like. ), An aryloxy group (preferably having 6 to 20 carbon atoms, more preferably having 6 to 16 carbon atoms, and particularly preferably having 6 to 12 carbon atoms.
And examples thereof include phenyloxy and 2-naphthyloxy. ), Acyl group (preferably having 1 to 1 carbon atoms)
20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, acetyl, benzoyl,
Formyl, pivaloyl and the like can be mentioned. ), An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 16 carbon atoms, particularly preferably having 2 to 12 carbon atoms, and examples thereof include methoxycarbonyl, ethoxycarbonyl, and cyclohexyloxycarbonyl.) An aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, particularly preferably having 7 to 10 carbon atoms, such as phenyloxycarbonyl), and an acyloxy group (preferably, phenyloxycarbonyl). 2 to 20 carbon atoms, more preferably 2 to 1 carbon atoms
6, particularly preferably having 2 to 10 carbon atoms, such as acetoxy and benzoyloxy. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably having 2 to 10 carbon atoms, such as acetylamino and benzoylamino), and an alkoxycarbonylamino group. (Preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms,
Particularly preferably, it has 2 to 12 carbon atoms, such as methoxycarbonylamino. ), An aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, and particularly preferably having 7 carbon atoms)
To 12, for example, phenyloxycarbonylamino and the like. ), A sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms, for example, methanesulfonylamino, benzenesulfonylamino, etc.), and sulfamoyl. Group (preferably having 0 to 2 carbon atoms)
It has 0, more preferably 0 to 16 carbon atoms, and particularly preferably 0 to 12 carbon atoms, and examples thereof include sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, and phenylsulfamoyl. ), A carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 1 carbon atoms)
6, particularly preferably having 1 to 12 carbon atoms, for example, carbamoyl, methylcarbamoyl, ethylcarbamoyl,
Diethylcarbamoyl, phenylcarbamoyl and the like. ), An alkylthio group (preferably having 1 to 1 carbon atoms)
20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, methylthio, ethylthio and the like. ), An arylthio group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably having 6 to 12 carbon atoms, such as phenylthio, etc.), and a sulfonyl group (preferably having 1 carbon atom). To 20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, mesyl, tosyl and the like.), A sulfinyl group (preferably 1 to 20 carbon atoms, more preferably carbon 1 to 16, particularly preferably 1 to 12 carbon atoms, for example, methanesulfinyl, benzenesulfinyl and the like.), Ureido group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly It preferably has 1 to 12 carbon atoms,
For example, ureide, methylureide, butylureide, phenylureide and the like can be mentioned. ), A phosphoric amide group (preferably having 1 to 20 carbon atoms, more preferably having 1 carbon atom)
To 16, particularly preferably 1 to 12 carbon atoms, for example, diethylphosphoramide, phenylphosphoramide and the like. ), Hydroxy, mercapto, halogen (eg, fluorine, chlorine, bromine, iodine), cyano, sulfo, carboxyl, nitro, hydroxamic acid, sulfino, hydrazino,
Heterocyclic groups (eg imidazolyl, pyridyl, furyl,
Thienyl, piperidyl, morpholino and the like can be mentioned. ). These substituents may be further substituted. When there are two or more substituents,
They may be the same or different.

R ₂₁ and R ₂₂ are preferably a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, an aryloxy group, a cyano group, a halogen atom, a nitro group, and a heterocyclic group, and more preferably a hydrogen atom, Alkyl group,
Aryl group, alkoxy group, aryloxy group, halogen atom, heterocyclic group, more preferably hydrogen atom, alkyl group, aryl group, alkoxy group, thienyl group, particularly preferably hydrogen atom, alkyl group .

The group bonded to the thiophene or furan ring formed by Z is preferably a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, a hydroxy group, an alkoxy group, an aryloxy group, a cyano group, a halogen atom,
A nitro group, a carboxyl group, an amino group, an acyl group, more preferably a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group, an alkoxy group, an aryloxy group, or a halogen atom; An atom, an alkyl group, an aryl group, and a heterocyclic group are preferable, and a hydrogen atom and an alkyl group are particularly preferable.

Examples of the compound represented by formula (II) are shown below, but the present invention is not limited thereto.

[0040]

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[0041]

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[0042]

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The compound represented by the general formula (II) of the present invention is, for example, described in Tetrahedron Letters, 1981, Vol. 22, 345-8.
J. Heterocycl.Chem, 1980, Vol. 17, pp. 1019-23, Bull
l. Soc. Chim. Fr., 1967, pp. 4220-35, Bull. Soc. Ch.
im. Fr., 1967, pages 2495-507, French Patent No. 1453.
Those skilled in the art can easily synthesize them by known methods described in, for example, No. 897.

The compound represented by the general formula (II) of the present invention may be added to the image forming layer side of the heat-developable photographic material, whether it is a photosensitive layer which can be an image forming layer or a non-photosensitive layer such as a protective layer. Can be.

The compounds represented by the general formula (II) of the present invention may vary depending on the desired purpose, 10 ^-4 to 1 mol / Ag shows the addition amount per Ag1 mole, preferably 10 ^-3 to 0.3 mol / Ag,
It is more preferable to add 10 ^{−3 to} 0.1 mol / Ag.

The compound represented by the general formula (II) of the present invention may be added by any method such as a solution, a powder and a dispersion of solid fine particles. Dispersion of solid fine particles can be performed by a known micronizing means (for example, ball mill, vibrating ball mill, side mill,
Colloid mill, jet mill, roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

In the present invention, the ratio of the amount of the compound represented by the general formula (I) to the amount of the compound represented by the general formula (II) is more than the amount of the compound represented by the general formula (I). The formula (I
0.1 to 1000% by mole ratio of the compound represented by I),
Preferably 10 to 300%, more preferably 30 to 20%
It is preferably 0%. The heat-developable photographic material of the present invention comprises a compound represented by the general formula (I) and a compound represented by the general formula (II):
May be used one kind each of the compounds represented by
Two or more kinds may be added. The compound represented by the general formula (II) of the present invention and the compound represented by the general formula (I) of the present invention may be added either in the same layer or in separate layers. It is also possible to add the compound by changing the amount ratio for each layer.

Next, the compound represented by formula (III) will be described. In the general formula (III), T represents a monovalent substituent, and k represents an integer of 0 or more and 4 or less. k = 0 represents all hydrogen atoms, and when k ≧ 2, a plurality of Ts may be the same or different, and may be bonded to each other to form a ring. When a plurality of Ts are not bonded to each other to form a ring, k is preferably 0 to 2,
0 or 1 is particularly preferred.

M ₁ and M ₂ are each a hydrogen atom or a cation (eg, an alkali metal such as sodium or potassium), which may be the same or different,
It is preferred that both M ₁ and M ₂ are hydrogen atoms.

As the monovalent substituent represented by T, for example, an alkyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 12 carbon atoms, particularly preferably having 1 to 8 carbon atoms, and , Ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl, etc.), alkenyl group (Preferably having 2 to 2 carbon atoms
20, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, such as vinyl, allyl, 2-butenyl and 3-pentenyl. ), Alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 2 carbon atoms)
12, particularly preferably 2 to 8, for example, propargyl, 3-pentynyl and the like. ), An aryl group (preferably having 6 to 30 carbon atoms, more preferably having 6 carbon atoms)
-20, particularly preferably 6-12 carbon atoms, for example, phenyl, p-methylphenyl, naphthyl and the like. ), An amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, and particularly preferably 0 to 0 carbon atoms).
6, for example, amino, methylamino, dimethylamino, diethylamino, dibenzylamino and the like. ), An alkoxy group (preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, particularly preferably 1 carbon atom
To 12, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, hexyloxy, dodecyloxy, hexadecyloxy, allyloxy, benzyloxy and the like. ), An aryloxy group (preferably having 6 to 20 carbon atoms, more preferably having 6 carbon atoms)
To 16, particularly preferably 6 to 12 carbon atoms, such as phenyloxy and 2-naphthyloxy. ), An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 1 carbon atoms).
2, for example, acetyl, benzoyl, formyl, pivaloyl, piperidinocarbonyl and the like. ),
An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms;
More preferably, it has 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, and examples thereof include methoxycarbonyl, ethoxycarbonyl, and tetradecyloxycarbonyl. ), An aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, particularly preferably having 7 to 10 carbon atoms, such as phenyloxycarbonyl, etc.), and an acyloxy group (preferably). Is 2 to 20 carbon atoms, more preferably 2 carbon atoms
-16, particularly preferably 2-10 carbon atoms, such as acetoxy and benzoyloxy. ),
Acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 10 carbon atoms)
For example, acetylamino, propionylamino,
Valerylamino, benzoylamino and the like. ), An alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 16 carbon atoms, particularly preferably having 2 to 12 carbon atoms, and examples thereof include methoxycarbonylamino and the like), aryloxycarbonylamino Group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, particularly preferably having 7 to 12 carbon atoms)
And for example, phenyloxycarbonylamino and the like. ), A sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methanesulfonylamino, octanesulfonylamino, benzenesulfonylamino, etc. ), A sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 1 carbon atoms).
6, particularly preferably having 0 to 12 carbon atoms, for example, sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl and the like. ), A carbamoyl group (preferably having 1 to 20 carbon atoms,
More preferably, it has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, carbamoyl, methylcarbamoyl, dimethylcarbamoyl, diethylcarbamoyl,
Phenylcarbamoyl and the like. ), An alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms,
For example, methylthio, ethylthio and the like can be mentioned. ),
Arylthio group (preferably having 6 to 20 carbon atoms, more preferably having 6 to 16 carbon atoms, particularly preferably having 6 to 12 carbon atoms)
And for example, phenylthio and the like. ), A sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms, such as mesyl and tosyl), and a sulfinyl group (preferably It has 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, methanesulfinyl, benzenesulfinyl and the like, and a ureido group (preferably 1 to 20 carbon atoms). More preferably, it has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, ureide, methyl ureide, phenyl ureide and the like, and a phosphoric amide group (preferably 1 to 20 carbon atoms, more preferably). Has 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as diethylphosphoramide, phenylphosphoramide and the like. ), Hydroxy, carboxyl, sulfo, sulfino (sulfinic acid), mercapto, halogen (eg, fluorine, chlorine, bromine, iodine), cyano, nitro, hydroxamic acid Group, hydrazino group, heterocyclic group (for example, imidazolyl, pyridyl, furyl, piperidyl, morpholino and the like). Further, the substituent capable of forming a salt with an alkali metal or the like may form a salt. These substituents may be further substituted. When there are two or more substituents, they may be the same or different. As an example in which a plurality of Ts are bonded to each other to form a ring, any known condensed phthalic acid can be used. Preferred examples include [3,4] benzo, [4,5] benzo, [4,5] naft, [3,4]
Examples include dioxolo, [4,5] dioxolo, [4,5] imidazo, [4,5] thiazo, and [4,5] oxazo.

The substituent represented by T is preferably an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an acyloxy group, an alkoxycarbonyl group, an acylamino group, an alkoxy group, including a condensed ring. Carbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, amino group, alkylthio group, ureido group, phosphoric amide group, hydroxy group, carboxyl group, sulfo group, sulfino group, sulfonyl group, halogen Atom, cyano group, nitro group, heterocyclic group, [3,4]
Benzo, [4,5] benzo, [4,5] naphtho, [3,
4] dioxolo and [4, 5] dioxolo, more preferably alkyl, aryl, alkoxy, aryloxy, acyl, acylamino, sulfonylamino, sulfamoyl, carbamoyl, hydroxy, sulfonyl groups , A halogen atom, a cyano group,
[3,4] benzo, [4,5] benzo, [3,4] dioxolo, [4,5] dioxolo, particularly preferably an alkyl group, an aryl group, an alkoxy group, [4,5] benzo, [4 , 5] dioxolo.

Compounds represented by the general formula (III) of the present invention include, for example, New Experimental Chemistry Course (Maruzen) 14-III, Organic
Fanctional Group Preparetions (Academic Press New
It can be easily synthesized by those skilled in the art by a known method described in Yorkand London) I. Also, various commercially available reagents can be used.

Specific examples of the compound represented by formula (III) are shown below, but the present invention is not limited thereto.

[0054]

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[0055]

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[0056]

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[0057]

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[0058]

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The compound represented by the general formula (III) of the present invention may be added to the image forming layer side of the heat-developable photographic material, whether it is a photosensitive layer which can be an image forming layer or a non-photosensitive layer such as a protective layer. Can be.

The compounds represented by the general formula (III) of the present invention may vary depending on the desired purpose, 10 ^-4 to 1 mol / Ag shows the addition amount per Ag1 mole, preferably 10 ^-3 to 0.3 mol / A
g, more preferably 10 ^{-3 to} 0.1 mol / Ag. In the heat-developable photographic material of the present invention, only one compound represented by the general formula (III) may be used, or two or more compounds may be used in combination.

The compound represented by the general formula (III) of the present invention may be added by any method such as a solution, a powder and a dispersion of solid fine particles. Dispersion of solid fine particles can be performed by a known micronizing means (for example, ball mill, vibrating ball mill, side mill,
Colloid mill, jet mill, roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

The organic silver salt which can be used as the reducible silver salt in the present invention is relatively stable to light,
A silver salt that forms a silver image when heated to 80 ° C. or higher in the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent. The organic silver salt can be any organic substance including a source capable of reducing silver ions. Silver salts of organic acids, especially (C 10-30, preferably 1
Silver salts of long chain fatty carboxylic acids (5-28) are preferred. Complexes of organic or inorganic silver salts wherein the ligand has a complex stability constant in the range of 4.0 to 10.0 are also preferred. The silver donor material can preferably comprise about 5-70% by weight of the imaging layer. Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. Examples of these include, but are not limited to, silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the silver salt of an aliphatic carboxylic acid include silver behenate, silver stearate, silver oleate,
Silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate, silver fumarate, silver tartrate, silver linoleate, silver butyrate and silver camphorate, and mixtures thereof.

In applying the organic silver salt, a method of treating the organic silver salt as a finely dispersed dispersion is preferably used. As a method for finely dispersing the organic silver salt microcrystals, known fine refining means (for example, a high-speed mixer, a homogenizer, a high-speed impact mill, a Banbury mixer, a homomixer, a kneader, a ball mill, a vibration ball mill, , Planetary ball mill, attritor,
It is known to mechanically disperse using a sand mill, a bead mill, a colloid mill, a jet mill, a roller mill, a tron mill, a high-speed stone mill). For the fine dispersion apparatus and its technology, see, for example, "Dispersion Rheology and Dispersion Technology" (Toshio Kajiuchi, Hiroki Usui, 1991, Shinzansha Publishing Co., Ltd., P357-P403), "Progress in Chemical Engineering No. 24
Shu "(edited by the Society of Chemical Engineers, Tokai Branch, 1990, Maki Shoten, P184-P185).

In the present invention, when the organic silver salt is handled in an aqueous solvent, a method in which the organic silver salt is handled as a finely dispersed dispersion in water is preferably used.

A high-pressure homogenizer is suitable as a preferred method for producing an organic silver salt aqueous dispersion having a small particle size and no aggregation. As a dispersing device of this type, a Gaulin homogenizer has been used in the past, and devices capable of dispersing at a higher pressure have been developed in recent years, and a typical example thereof is a microfluidizer (Microfluidics International Corporation). Co., Ltd.) and Nanomizer (Special Kika Kogyo Co., Ltd.). A dispersion method including a step of converting the organic silver salt into a high-pressure, high-speed stream and then reducing the pressure is a preferable method of finely dispersing the organic silver salt in water.

It is preferable that the raw material liquid is preliminarily dispersed before the dispersion operation. As means for preliminary dispersion, known dispersion means (for example, high-speed mixer, homogenizer, high-speed impact mill, Banbury mixer, homomixer, kneader, ball mill, vibration ball mill, planetary ball mill, attritor, sand mill, bead mill, colloid mill,
Jet mill, roller mill, tron mill, high-speed stone mill) can be used. Instead of mechanically dispersing, fine particles may be formed by coarsely dispersing in a solvent by controlling the pH and then changing the pH in the presence of a dispersing agent. At this time, an organic solvent may be used as a solvent used for the coarse dispersion, and the organic solvent is usually removed after completion of the fine particle formation.

In the present invention, it is preferable to disperse the organic silver salt in the presence of a dispersant (dispersing aid) soluble in an aqueous medium.
Examples of the dispersing aid include polyacrylic acid, a copolymer of acrylic acid, a maleic acid copolymer, a maleic acid monoester copolymer, an acryloylmethylpropanesulfonic acid copolymer, and a synthetic anionic polymer such as carboxymethyl. Semi-synthetic anionic polymers such as starch and carboxymethylcellulose, anionic polymers such as alginic acid and pectic acid, JP-A-52-92716, WO 88/04794
No. 7-350753
Or known anionic, nonionic, cationic surfactants, and other known polymers such as polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose, or nature such as gelatin. Can be appropriately selected and used, but polyvinyl alcohols and water-soluble cellulose derivatives are particularly preferred.

It is a general method that the dispersing aid is mixed with the organic silver salt powder or the organic silver salt in a wet cake state before the dispersion, and then sent as a slurry to the dispersing machine. Heat treatment or treatment with a solvent may be performed in the combined state to obtain an organic silver salt powder or a wet cake. The pH may be controlled by a suitable pH adjuster before, during or after dispersion.

The prepared dispersion is stored with stirring for the purpose of suppressing sedimentation of the fine particles during storage, or stored in a highly viscous state by a hydrophilic colloid (for example, in a jelly state using gelatin). You can also do.
Further, a preservative can be added for the purpose of preventing the propagation of various bacteria during storage.

The organic silver salt which can be used in the present invention is
Preferably, desalting can be performed. The method for desalting is not particularly limited, and a known method can be used. However, a known filtration method such as centrifugal filtration, suction filtration, ultrafiltration, or floc-forming water washing by a coagulation method can be preferably used. The desalting is preferably performed at a stage after the synthesis of the organic silver salt until dispersion, but may be performed at any stage depending on the purpose.

The particle size (volume-weighted average diameter) of the organic silver salt solid fine particle dispersion of the present invention is determined, for example, by irradiating a solid fine particle dispersion dispersed in a liquid with a laser beam and changing the scattered light fluctuation over time. It can be obtained from the particle size (volume weighted average diameter) obtained by obtaining the autocorrelation function. A solid fine particle dispersion having an average particle size of 0.05 μm or more and 10.0 μm or less is preferable. The average particle size is more preferably 0.1 μm or more and 5.0 μm or less, and still more preferably the average particle size is 0.1 μm or more and 2.0 μm or less.

The particle size distribution of the organic silver salt is preferably monodispersed. Specifically, the percentage of the standard deviation of the volume-weighted average diameter divided by the volume-weighted average diameter (coefficient of variation)
Is 80% or less, more preferably 50% or less, even more preferably 30%
% Or less.

The shape of the organic silver salt can be measured from a transmission electron microscope image of the organic silver salt dispersion.

The organic silver salt solid fine particle dispersion used in the present invention comprises at least an organic silver salt and water. The ratio of the organic silver salt to water is not particularly limited, but the ratio of the organic silver salt to the whole is preferably 5 to 50% by weight, and more preferably 10 to 30% by weight.
Although it is preferable to use the above-mentioned dispersing aid, it is preferable to use the dispersing aid in the minimum amount within a range suitable for minimizing the particle size.
A range of weight% is preferred.

In the present invention, it is possible to prepare a photographic material by mixing an aqueous dispersion of an organic silver salt and an aqueous dispersion of a photosensitive silver salt, but the mixing ratio of the organic silver salt and the photosensitive silver salt may be varied depending on the purpose. The ratio of the photosensitive silver salt to the organic silver salt is 1 to 3
It is preferably in the range of 0 mol%, more preferably 3 to 20 mol%, especially 5 to 20 mol%.
It is preferably in the range of ~ 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 adjusting photographic characteristics.

The photosensitive silver salt used in the present invention includes:
Photosensitive silver halide is preferred.

The method for forming the photosensitive silver halide in the present invention is well known in the art, and uses, for example, the methods described in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. be able to. 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 μm or more and 0.15 μm or less, and still more preferably 0.02 μm or more. 0.12μm
The following is good. Here, the grain size means the length of the edge of the silver halide grain when the silver halide grain is a cubic or octahedral so-called normal crystal. In the case where the silver halide grains are tabular grains, the diameter refers to a diameter when converted into a circular image having the same area as the projected area of the main surface. In the case of other than normal crystals, for example, in the case of spherical grains, rod-shaped grains, etc., it refers to the diameter of a sphere equivalent to the volume of silver halide grains.

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 and tabular particles are particularly preferable. When tabular silver halide grains are used, the average aspect ratio is preferably 100: 1 to 2: 1, more preferably 50: 1 to 3: 1. Further, 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 it is preferable that the proportion of the surface having high spectral sensitization efficiency when the spectral sensitizing dye used is adsorbed is high. . The ratio is preferably at least 50%, more preferably at least 65%, even more preferably at least 80%. The ratio of the Miller index is determined by the method described in T. Tani; J. Imaging Sci., 29, 165 (1985), which utilizes the adsorption dependence of the {111} plane and the {100} plane in the adsorption of the sensitizing dye. You can ask. The halogen composition of the photosensitive silver halide is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide, and silver iodide. In the present invention, silver bromide or silver iodobromide can be preferably used. Particularly preferred is silver iodobromide, and the silver iodide content is preferably from 0.1 mol% to 40 mol%, more preferably from 0.1 mol% to 20 mol%.
The following is more preferred. The distribution of the halogen composition in the grains may be uniform, the halogen composition may be changed stepwise, or may be changed continuously, but as a preferred example, the silver iodide content of the grain surface High silver iodobromide grains can be used. Preferably, silver halide grains having a core / shell structure can be used. The structure is preferably 2
Core / shell particles having a ５5-fold structure, more preferably a 2- to 4-fold structure, can be used.

The photosensitive silver halide grains of the present invention preferably contain at least one metal complex selected from rhodium, rhenium, ruthenium, osmium, iridium, cobalt, mercury or iron. 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 preferable content is in the range of 1 nmol to 10 mmol, and more preferably in the range of 10 nmol to 100 µmol per 1 mol of silver. As a specific structure of the metal complex, a metal complex having a structure described in JP-A-7-225449 or the like can be used. As the compound of cobalt and iron, a hexacyano metal complex can be preferably used. Specific examples include a ferricyanate ion, a ferrocyanate ion, and a hexacyanocobaltate ion, but are not limited thereto. The content of the metal complex in the silver halide may be uniform, may be contained at a high concentration in the core portion, or may be contained at a high concentration in the shell portion, and there is no particular limitation.

The photosensitive silver halide grains can be desalted by washing with water by a method known in the art such as a noodle method or a flocculation method, but in the present invention, it may or may not be desalted. .

The photosensitive silver halide grains in the present invention are preferably chemically sensitized. As a preferred chemical sensitization method, a sulfur sensitization method, a selenium sensitization method, and a tellurium sensitization method are well known in the art. Further, a noble metal sensitization method or a reduction sensitization method of a gold compound, platinum, palladium, an iridium compound or the like can be used. As the compound preferably used in the sulfur sensitization method, the selenium sensitization method, and the tellurium sensitization method, known compounds can be used, and the compounds described in JP-A-7-128768 can be used. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, P = Te Compounds having a bond, tellurocarboxylates, Te-organyltellurocarboxylates, di (poly) tellurides, tellurides, tellurols, telluroacetals, tellurosulfonates, P-Te
Compounds having a bond, Te-containing heterocycles, tellurocarbonyl compounds, inorganic tellurium compounds, colloidal tellurium, and the like can be used. Compounds preferably used in the noble metal sensitization method include, for example, chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, gold selenide, or U.S. Pat.
Compounds described in JP 18,061, etc. can be preferably used. As specific compounds of the reduction sensitization method, in addition to ascorbic acid and thiourea dioxide, for example, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds and the like can be used. . Reduction sensitization can be achieved by ripening the emulsion while maintaining the pH of the emulsion at 7 or more or the pAg at 8.3 or less. Further, reduction sensitization can be achieved by introducing a single addition portion of silver ion during grain formation.

The amount of the photosensitive silver halide used in the present invention is preferably from 0.01 mol to 0.5 mol, more preferably from 0.02 mol to 0.3 mol, and more preferably from 0.03 mol to 0.3 mol, per mol of the organic silver salt. It is particularly preferably at least 0.25 mol and not more than 0.25 mol.

In preparing the coating solution of the present invention, a polymer latex, gelatin or polyvinyl alcohol (P
VA) can be used. Among these, a polymer that can be dissolved or dispersed in an aqueous solvent is preferable.

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.

In a preferred embodiment of the present invention, acrylic resin, polyester resin, rubber resin (for example, S
(BR resin), a polyurethane resin, a vinyl chloride resin, a vinyl acetate resin, a vinylidene chloride resin, a hydrophobic polymer such as a polyolefin resin. 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 molecular weight of the polymer is 5000 to 100000, preferably 10,000 to 2000 in number average molecular weight.
00 is preferred. If the molecular weight is too small, the mechanical strength of the emulsion layer is insufficient, and if it is too large, the film-forming properties are poor, which is not preferable.

The preferred polymers of the present invention are those in which these polymers are dispersed in an aqueous dispersion medium.
Here, the aqueous system 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, micellar dispersed state, and further, a polymer having a hydrophilic portion in a molecule dispersed in a molecular state. Of these, latex is particularly preferred.

The equilibrium water content of the polymer of the present invention at 25 ° C. and 60% RH is preferably 2% by weight or less, more preferably 0.01% by weight or more and 1.5% by weight or less, further preferably 0.02% by weight or less.
It is desirable that the content be at least t% and at most 1 wt%.

The term “equilibrium water content at 25 ° C. and 60% RH” as used in the present invention refers to the weight W1 of a polymer in humidity control equilibrium in an atmosphere of 25 ° C. and 60% RH and the weight of a polymer in an absolutely dry state at 25 ° C. weight
It can be expressed as follows using W0. Equilibrium water content at 25 ° C and 60% RH = {(W1-W0) / W0} x 100 (wt%)

For the definition and measurement method of water content, see, for example, Polymer Engineering Course 14, Polymer Material Testing Method (edited by the Society of Polymer Science,
You can refer to Citizen Library).

Specific examples of preferred polymers include the following. In the following, the raw material monomers are used, and the numerical values in parentheses are% by weight, and the molecular weight is the number average molecular weight.

Latex of P-1; -MMA (70) -EA (27) -MAA (3)-(molecular weight 37,000) P-2; -MMA (70) -2EHA (20) -St (5) -AA (5)-latex
(Molecular weight 40000) P-3; -St (70) -Bu (25) -AA (5)-latex (molecular weight 60000) P-4; -St (60) -Bu (35) -DVB (3)- MAA (2)-latex (molecular weight
150000) P-5; latex of -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-(molecular weight 80000) P-6; -VDC (85) -MMA ( 5) Latex of -EA (5) -MAA (5)-(molecular weight 67,000) P-7; Latex of -Et (90) -MAA (10)-(molecular weight 12000)

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;
C; vinyl chloride, AN; acrylonitrile, VDC; vinylidene chloride, Et; ethylene.

The polymers described above are also commercially available, and the following polymers can be used. Examples of the acrylic resin include Sebian A-4635, 46583, 4601 (all manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 82
Examples of polyester resins such as 0, 857 (all manufactured by Nippon Zeon Co., Ltd.) include FINETEX ES650, 611, 675, 850 (all manufactured by Dainippon Ink & Chemicals, Inc.), WD-size, WMS (all Eastman Examples of polyurethane resins include HYDRAN AP10, 20, 30, and 40 (all manufactured by Dainippon Ink and Chemicals, Inc.). Examples of rubber resins include LACSTAR.
Examples of vinyl chloride resins such as 7310K, 3307B, 4700H, 7132C (manufactured by Dainippon Ink & Chemicals, Inc.), Nipol Lx416, 410, 438C, 2507 (manufactured by Nippon Zeon Co., Ltd.) include G3
Examples of vinylidene chloride resins such as 51 and G576 (Nippon Zeon Co., Ltd.) include L502 and L513 (all manufactured by Asahi Kasei Kogyo Co., Ltd.); and examples of olefin resins include Chemipearl S120 and SA100 (Mitsui Petrochemical Co., Ltd.).

These polymers may be used alone as a polymer latex, or two or more may be blended if necessary.

The polymer latex used in the present invention is particularly preferably a copolymer latex containing a styrene-butadiene copolymer component. 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. Further, the proportion of the copolymer of the monomer unit of styrene and the monomer unit of butadiene is 60 to
Preferably it is 99% by weight. The preferred molecular weight range is the same as described above. Other components include acrylic acid, methacrylic acid, acrylonitrile, divinylbenzene and the like. Preferred are acrylic acid and methacrylic acid.

Styrene which is preferably used in the present invention
As the latex of the butadiene copolymer, the above-mentioned P-
3, P-4, commercial products LACSTAR 3307B, 7132C, Nipol Lx
416 and the like.

In a preferred embodiment in which a polymer latex is used in the organic silver salt-containing layer of the photographic material of the present invention, gelatin, polyvinyl alcohol, methyl cellulose,
A hydrophilic polymer such as hydroxypropyl cellulose may be added. The amount of the hydrophilic polymer to be added is preferably 30% by weight or less, more preferably 20% by weight or less of the total binder in the organic silver salt-containing layer.

The organic silver salt-containing layer of the present invention is preferably formed using a polymer latex. The amount of the binder in the organic silver salt-containing layer is such that the weight ratio of total binder / organic silver salt is 1%. / 10 to 10/1, furthermore, 1/5 to
A range of 4/1 is preferred.

Such an organic silver salt-containing layer is preferably a photosensitive layer (emulsion layer) containing photosensitive silver halide, and in such a case, the weight ratio of total binder / silver halide is used. Is 400 to 5, more preferably 200 to 1.
A range of 0 is preferred.

In the photographic material of the present invention, the solvent used for the coating solution for the organic silver salt-containing layer (here, for simplicity, the solvent and the dispersing medium are collectively referred to as a solvent) may be a solvent containing water or not containing water. The solvent may be an organic solvent, but is preferably an aqueous solvent containing 30% by weight or more of water. As organic solvents, toluene, ethyl methyl ketone, methanol, ethanol, propanol, 2-propanol, acetone,
Examples include ethyl acetate and butyl acetate. As a component of the aqueous solvent other than water, any water-miscible organic solvent such as methanol, ethanol, propanol, 2-propanol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate may be used. The water content of the solvent in the coating liquid is preferably at least 50% by weight, more preferably at least 70% by weight. Preferred examples of the solvent composition include water and water / methyl alcohol = 9.
0/10, 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 (numerical values are% by weight).

The heat-developable photographic material of the present invention comprises a support,
It has an organic silver salt which is a reducible silver salt, a reducing agent and a binder, more preferably has a photosensitive silver halide which is a photocatalyst, and the photosensitive silver halide and the organic silver salt are preferably the same. The organic silver salt-containing layer which is contained in one layer and is an image forming layer is preferably a photosensitive layer. Further, a reducing agent may be contained in the same layer.

The organic silver salt-containing layer of the photographic material of the present invention may be a single layer or two or more layers. The organic silver salt-containing layer is preferably on one side of the support, but may be on both sides. When two or more organic silver salt-containing layers are present, at least one layer is formed using a solid dispersion of the organic silver salt and preferably a polymer latex, and is preferably applied using an aqueous solvent as a coating solvent. Any layer may be used as long as the layer is an organic silver salt-containing layer according to the present invention.

In the photographic material of the present invention, the thickness of the organic silver salt-containing layer which can be a photosensitive layer is 0.2 to 30 μm per layer.
, More preferably in the range of 1 to 20 μm.

Such an organic silver salt-containing layer is formed using a coating solution containing components according to the composition of the organic silver salt-containing layer and a coating solvent, preferably an aqueous solvent. The ratio of the component (solid content) to the preferably used aqueous solvent is usually such that the weight ratio of the component / the aqueous solvent is 1/99.
About 40/60. Drying after application is 30-200
C. for about 30 seconds to 30 minutes. Such a layer can be applied separately from other layers such as a surface protective layer,
Simultaneous multilayer coating can also be performed. Furthermore, these two or more layers can be dried simultaneously. Prior to drying, it may be held at a temperature of about 0 to 20 ° C. for about 5 seconds to 10 minutes.

[0105] In the heat developable photographic material of the present invention, although the organic silver salt can be used in a desired amount, show a coating amount per photographic material 1 m ^2, preferably 0.1 to 20 g / m ^2, more preferably 1 to 12 g / m ² .

In the photographic material of the present invention, a reducing agent may be added to any layer.

The reducing agent for the organic silver salt may be any substance that reduces silver ions to metallic silver, preferably an organic substance. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful, but hindered phenol reducing agents are preferred. The reducing agent is an organic silver salt 6 to
It should be present as 60 mol%. In the case of adding a reducing agent to a layer other than the emulsion layer in a multilayer structure,
A slightly higher percentage, about 8-80 mol%, tends to be more desirable.

A wide range of reducing agents have been disclosed for photothermographic materials utilizing an organic silver salt. For example, amide oximes such as phenylamide oxime, 2-thienyl amide oxime and p-phenoxyphenyl amide oxime; azines such as 4-hydroxy-3,5-dimethoxybenzaldehyde azine; 2,2'-bis (hydroxymethyl A) combinations of aliphatic carboxylic acid aryl hydrazides, such as the combination of propionyl-β-phenylhydrazine with ascorbic acid, and ascorbic acid; polyhydroxybenzene, hydroxylamine,
A combination of reductone and / or hydrazine, such as a combination of hydroquinone and bis (ethoxyethyl) hydroxylamine, piperidinohexose reductone or formyl-4-methylphenylhydrazine;
Phenylhydroxamic acid; hydroxamic acids such as azine, p-hydroxyphenylhydroxamic acid and β-alinine hydroxamic acid; Α) such as ethyl-α-cyano-2-methylphenylacetate and ethyl-α-cyanophenylacetate;
-Cyanophenylacetic acid derivatives; 2,2'-dihydroxy-1,1'-binaphthyl, 6,6'-bibromo-2,
Bis-β-naphthol as exemplified by 2′-dihydroxy-1,1′-binaphthyl and bis (2-hydroxy-1-naphthyl) methane; bis-β-naphthol and 1,3-dihydroxybenzene derivatives (for example, , 2,4
-Dihydroxybenzophenone or 2 ', 4'-dihydroxyacetophenone); 3-methyl-
5-pyrazolone, such as 1-phenyl-5-pyrazolone; reductones as exemplified by dimethylaminohexose reductone, anhydrodihydroaminohexose reductone and anhydrodihydropiperidone hexose reductone; 2,6 Sulfonamide phenol reducing agents such as -dichloro-4-benzenesulfonamidophenol and p-benzenesulfonamidophenol; 2-phenylindane-1,3-dione;
Chromanes such as 2-dimethyl-7-tert-butyl-6-hydroxychroman; 1,4 such as 2,6-dimethoxy-3,5-dicarboethoxy-1,4-dihydropyridine
-Dihydropyridine; bisphenol (for example, bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-ethylidene-bis (2
-T-butyl-6-methylphenol) and 2,2-
Bis (3,5-dimethyl-4-hydroxyphenyl) propane etc.); ascorbic acid derivatives (e.g. 1-ascorbyl palmitate, ascorbyl stearate etc.); and aldehydes and ketones such as benzyl and biacetyl; 3-pyrazolidone and some Species of indane-1,3-dione and the like.

In the present invention, the silver halide emulsion and / or
And the organic silver salt can be further protected against the formation of additional fog by antifoggants, stabilizer precursors, and stabilized against reduced sensitivity during storage in inventory. Suitable antifoggants, stabilizers and stabilizer precursors which can be used alone or in combination are the thiazonium salts described in U.S. Pat.Nos. 2,131,038 and 2,694,716, the U.S. Pat.Nos. 2,886,437 and 2,444, 60
No. 5, azaindene, U.S. Pat.No. 2,728,663, mercury salt, U.S. Pat.No. 3,287,135, urazole, U.S. Pat. Nitroindazole, polyvalent metal salts described in U.S. Pat.No. 2,839,405, thiuronium salts described in U.S. Pat.No. 3,220,839, and palladium, platinum and gold salts described in U.S. Pat.Nos. 2,566,263 and 2,597,915.
Halogen-substituted organic compounds described in U.S. Pat.Nos. 4,108,665 and 4,442,202; U.S. Pat.Nos. 4,128,557 and 4,137,079; 4,138,365 and 4,45
9,350, and U.S. Pat.
And the phosphorus compounds described in No. 985.

The antifoggant preferably used in the present invention is an organic halide, for example, as described in JP-A-50-119624.
No. 50-120328, No. 51-121332, No. 54-58022, No.
56-70543, 56-99335, 59-90842, 61-12964
No. 2, 62-129845, JP-A-6-208191, 7-5621,
Nos. 7-2781, 8-15809, U.S. Pat.
Compounds such as those disclosed in US Pat.

Although not required to practice the present invention,
It may be advantageous to add a mercury (II) salt as an antifoggant to the emulsion layer. Preferred mercury (II) salts for this purpose are mercury acetate and mercury bromide.

The heat-developable photographic material of the present invention may contain benzoic acids for the purpose of increasing the sensitivity and preventing fog. The benzoic acids of the present invention may be any benzoic acid derivative,
Examples of preferred constructions include U.S. Pat.
4,152,160, Japanese Patent Application Nos. 8-151242, 8-151241, 8-
Compounds described in 98051 and the like. The benzoic acid of the present invention may be added to any part of the photographic material. However, it is preferable to add the benzoic acid to a layer having a photosensitive layer which can be an image forming layer, and More preferably, The benzoic acid of the present invention may be added at any time during the preparation of the coating solution, and when it is added to the organic silver salt-containing layer, it may be added at any time from the preparation of the organic silver salt to the preparation of the coating solution. It is preferable after salt preparation and immediately before application. The benzoic acid of the present invention 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 reducing agent and a color tone agent.
The benzoic acid of the present invention may be added in any amount, but is preferably 1 μmol or more and 2 mol or less, more preferably 1 mmol or more and 0.5 mol or less per 1 mol of silver.

In the present invention, any method may be used for adding the materials necessary for the construction of the photographic material, such as a reducing agent, a color tone agent and an antifoggant. A method of adding as a fine particle dispersion is preferably used. As a specific method for forming solid fine particles, a desired solid fine particle dispersion can be obtained in the same manner as in the method for forming organic silver salts into solid fine particles. As the particle size of the finely divided solid dispersion, the average particle diameter is 0.005 μm.
m to 10 μm, preferably 0.01 μm to 3 μm, and more preferably 0.05 μm to 0.5 μm.

As the sensitizing dye in the present invention, any dye can be used as long as it can spectrally sensitize silver halide grains in a desired wavelength region when adsorbed on silver halide grains. As the sensitizing dye, a cyanine dye, a merocyanine dye, a complex cyanine dye, a complex merocyanine dye, a holopolar cyanine dye, a styryl dye, a hemicyanine dye, an oxonol dye, a hemioxonol dye, and the like can be used. Useful sensitizing dyes for use in the present invention include, for example, RESEARCH DISCLOSURE Item 17
Item 643IV-A (p.23, December 1978), Item 1831X (1979)
August, p. 437). Especially various laser imagers, scanners,
A sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of a light source of an image setter or a plate making camera can be advantageously selected.

Examples of spectral sensitization to red light include He-Ne
Lasers, so-called red light sources such as red semiconductor lasers and LEDs are described in I-1 to I-1 described in JP-A-54-18726.
-38, I-1 to I-35 described in JP-A-6-75322
Compounds and I-1 to I-34 described in JP-A-7-287338
From the dyes 1 to 20 described in JP-B-55-39818, from the compounds I-1 to I-37 described in JP-A-62-284343, and from the compounds described in JP-A-7-287338. The compound of I-34 and the like are advantageously selected.

For semiconductor laser light sources in the wavelength range of 750 to 1400 nm, various known dyes, including cyanine, merocyanine, styryl, hemicyanine, oxonol, hemioxonol and xanthene dyes, advantageously spectrally sensitize. Can be done. Useful cyanine dyes are, for example, cyanine dyes having basic nuclei such as thiazoline nuclei, oxazoline nuclei, pyrroline nuclei, pyridine nuclei, oxazole nuclei, thiazole nuclei, selenazole nuclei and imidazole nuclei. Preferred useful merocyanine dyes include, in addition to the above basic nuclei, acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus. Including. Among the above cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective. For example, U.S. Pat.
No. 3,719,495; No. 3,877,943; British Patent No.
Nos. 1,466,201, 1,469,117, 1,422,057,
JP-B-3-10391, JP-B6-52387, JP-A-5-341432,
The dye may be appropriately selected from known dyes as described in JP-A-6-194781 and JP-A-6-301141.

Particularly preferred structures of the dyes used in the present invention are cyanine dyes having a thioether bond-containing substituent (for example, JP-A Nos. 62-58239 and 3-1386).
No.38, No.3-138642, No.4-255840, No.5-72659, No.
5-72661, 6-222491, 2-230506, 6-258757
No., 6-317868, 6-324425, Tokuyohei 7-500926,
Dyes described in U.S. Pat.No. 5,541,054), dyes having a carboxylic acid group (for example, JP-A-3-163440,
No. 301141, U.S. Pat.No.5,441,899)
, Merocyanine dyes, polynuclear merocyanine dyes and polynuclear cyanine dyes (JP-A-47-6329, JP-A-49-105524, JP-A-51-524).
-127719, 52-80829, 54-61517, 59-21484
No. 6, No. 60-6750, No. 63-159841, JP-A-6-35109
No. 6-59381, No. 7-46537, No. 7-16537, JP-T 55-50111, UK Patent No. 1,467,638, U.S. Patent No. 5,
No. 281,515).

Further, dyes described in Example 5 of US Pat. Nos. 5,510,236 and 3,871,887, JP-A-2-96131, and JP-A-59-48753 are disclosed as dyes forming a J-band. Can be preferably used in the present invention.

These sensitizing dyes may be used alone.
Two or more kinds may be used in combination. Combinations of sensitizing dyes are often used, especially for supersensitization. Along with the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization and substances exhibiting supersensitization are
Research Disclosure Volume 176 17643 (Issued December 1978) 2
Section J on page 3, IV, or JP-B-49-25500, 43-4933
And JP-A-59-19032 and JP-A-59-192242.

The sensitizing dyes used in the present invention may be used in combination of two or more. To add sensitizing dyes to a silver halide emulsion, they may be directly dispersed in the emulsion,
Or water, methanol, ethanol, propanol,
Acetone, methyl cellosolve, 2,2,3,3-tetrafluoropropanol, 2,2,2-trifluoroethanol, 3-methoxy-1-propanol, 3-methoxy-1-butanol, 1-
It may be dissolved in a solvent such as methoxy-2-propanol or N, N-dimethylformamide alone or in a mixed solvent and added to the emulsion.

As disclosed in US Pat. No. 3,469,987, a dye is dissolved in a volatile organic solvent, and this solution is dispersed in water or a hydrophilic colloid. Method of adding into the inside, Japanese Patent Publication No. 44-23389,
As disclosed in JP-A-44-27555 and JP-A-57-22091, the dye is dissolved in an acid and this solution is added to the emulsion, or an acid or base is added to the emulsion as an aqueous solution in the presence of an acid or base. U.S. Pat.Nos. 3,822,135 and 4,006,025
JP-A-53-102733 and JP-A-58-105141 discloses a method of adding an aqueous solution or a colloidal dispersion in the presence of a surfactant to an emulsion as disclosed in JP-A-53-102733 and JP-A-58-105141. A method of directly dispersing a dye in a hydrophilic colloid and adding the dispersion to an emulsion as described in
As disclosed in JP-A-51-74624, a method in which a dye is dissolved using a compound that causes a red shift, and this solution is added to an emulsion can also be used. Also, ultrasonic waves can be used for dissolution.

The sensitizing dye used in the present invention may be added to the silver halide emulsion of the present invention at any stage of the emulsion preparation which has been found to be useful. For example, U.S. Pat.Nos. 2,735,766 and 3,628,96
No. 4, No. 4,183,756, No. 4,225,666, JP-A-58
As disclosed in the specifications of JP-A-184142 and JP-A-60-196749, chemical ripening is performed during the step of forming silver halide grains and / or before desalination, during and / or after desalination. Before the start of the process, as disclosed in the specification of JP-A-58-113920, etc., immediately before or during the chemical ripening, during the process, after the chemical ripening, the emulsion is coated before the coating. Any time before, it may be added in the process. Also, U.S. Pat.No.4,225,666, JP-A-58-762
As disclosed in the specification such as No. 9 or the like, the same compound may be used alone or in combination with a compound having a different structure, for example, during the particle formation step, during the chemical ripening step or after the completion of the chemical ripening, The compound may be added in portions such as before aging or during the process and after completion, or may be added by changing the kind of compound to be added and the combination of compounds.

The amount of the sensitizing dye used in the present invention may be a desired amount according to the performance such as sensitivity and fog.
The amount is preferably from 10 ^-6 to 1 mol, more preferably from 10 ^-4 to 10 ^-1 mol, per mol of silver halide in the photosensitive layer.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained in order to suppress or accelerate the development to control the development, to improve the spectral sensitization efficiency, to improve the storage stability before and after the development, and the like. be able to.

When a mercapto compound is used in the present invention, it may have any structure, but it may be Ar-SM, Ar-SS-Ar
Is preferably represented by In the formula, M is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring group or a condensed aromatic ring group having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably, the heteroaromatic ring in such groups is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole,
Benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole,
Tetrazole, triazine, pyrimidine, pyridazine,
Pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring includes, for example, halogen (e.g., Br and Cl), hydroxy, amino, carboxy, alkyl (e.g., having one or more carbon atoms, preferably 1-4 carbon atoms) and alkoxy.
(For example, those having one or more carbon atoms, preferably those having 1 to 4 carbon atoms). Examples of mercapto-substituted heteroaromatic compounds include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole,
6-ethoxy-2-mercaptobenzothiazole, 2,2'-dithiobis-benzothiazole, 3-mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1- Ethyl-2-mercaptobenzimidazole, 2-mercaptoquinoline, 8-mercaptopurine, 2-mercapto-4 (3H) -quinazolinone, 7-
Trifluoromethyl-4-quinolinethiol, 2,3,5,6-tetrachloro-4-pyridinethiol, 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate, 2-amino-5-mercapto-1 , 3,4-thiadiazole, 3-amino-5
-Mercapto-1,2,4-triazole, 4-hydrocyanic-2-
Mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-
Diamino-2-mercaptopyrimidine, 2-mercapto-4-
Examples include methylpyrimidine hydrochloride, 3-mercapto-5-phenyl-1,2,4-triazole, 2-mercapto-4-phenyloxazole, and the like, but the invention is not limited thereto.

The addition amount of these mercapto compounds is preferably in the range of 0.001 to 1.0 mol per mol of silver in the emulsion layer, more preferably 0.01 to 0.1 mol per mol of silver.
3 moles.

In the photosensitive layer (image forming layer) of the present invention, a polyhydric alcohol (for example, glycerin and diol of the type described in US Pat. No. 2,960,404) and a plasticizer and a lubricant may be used. And the fatty acid or ester described in U.S. Pat. No. 3,121,060 and the silicone resin described in British Patent No. 955,061.

In the present invention, a super-high contrast agent can be used for forming a super-high contrast image. For example, U.S. Patent 5,464,738
Nos. 5,496,695, 6,512,411, 5,536,622
No., Japanese Patent Application Nos. 7-228627, 8-215822, 8-13
0842, 8-148113, 8-156378, 8-148111,
The hydrazine derivative described in JP-A-8-148116, the compound having a quaternary nitrogen atom described in Japanese Patent Application No. 8-83566, and the acrylonitrile compound described in US Pat. No. 5,545,515 can be used. Specific examples of the compound include compounds 1 to 10 of the above-mentioned U.S. Patent No. 5,464,738, and
H-1 to H-28 of 5,496,695, I-1 of Japanese Patent Application No. 8-215822
I-86, H-1 to H-62 of 8-130842 and 1-H of 8-148113
1-1 to 1-21, 1 to 50 of 8-148111, 1 to 1 of 8-148116
No. 40, No. 8-83566, P-1 to P-26 and T-1 to T-18, and U.S. Pat. No. 5,545,515, CN-1 to CN-13.

Further, the present invention provides a method for forming a super-high contrast image.
A high contrast accelerator can be used in combination with the above-mentioned super-high contrast agent. For example, amine compounds described in U.S. Pat.No. 5,545,505, specifically AM-1 to AM-5, and hydroxamic acids described in 5,545,507, specifically HA-1 to HA-11,
Acrylonitrile described in 5,545,507, specifically
CN-1 to CN-13, hydrazine compounds described in 5,558,983, specifically, CA-1 to CA-6, onium salts described in Japanese Patent Application No. 8-132836, specifically A-1 to A-42, B-1
To B-27 and C-1 to C-14.

The synthesis method, addition method, addition amount and the like of these super-high contrast agents and high-contrast accelerators can be carried out as described in each of the cited patents.

The photographic material of the present invention can be provided with a surface protective layer for the purpose of preventing adhesion of the image forming layer.
The binder for the surface protective layer is not particularly limited, but a natural or synthetic resin, a synthetic polymer, or the like that can be used in the image forming layer can be preferably used. Examples of the anti-adhesion agent for which it is preferable to use an anti-adhesion agent for the surface protective layer include wax, silica particles, and a styrene-containing elastomeric block copolymer (eg, styrene-butadiene-styrene, styrene-isoprene-styrene). , Cellulose acetate, cellulose acetate butyrate, cellulose propionate and mixtures thereof.

In the present invention, the emulsion layer or the protective layer of the emulsion layer which is the image forming layer includes US Pat. No. 3,253,921,
Nos. 2,274,782, 2,527,583 and 2,956,
Light absorbing materials and filter dyes as described in 879 can be used. Alternatively, dyes can be mordant as described in, for example, US Pat. No. 3,282,699. The amount of the filter dye used is preferably from 0.1 to 3 at the exposure wavelength, particularly preferably from 0.2 to 1.5.

Various dyes and pigments can be used in the photosensitive layer of the heat-developable photographic material of the present invention from the viewpoint of improving color tone and preventing irradiation. Dyes and pigments used in the photosensitive layer of the present invention may be any, for example, pigments and dyes described in the Color Index, specifically, pyrazoloazole dye, anthraquinone dye, azo dye, azomethine dye, oxonol dye, Examples thereof include carbocyanine dyes, styryl dyes, triphenylmethane dyes, indoaniline dyes, indophenol dyes, organic pigments including phthalocyanine, and inorganic pigments. Preferred dyes used in the present invention include anthraquinone dyes (e.g., compounds 1 to 9 described in JP-A-5-341441, compounds 3-6 to 18 and 3-23 to 38 described in JP-A-5-165147), azomethine Dye (compound described in JP-A-5-341441)
17-47 etc.), indoaniline dyes (e.g.
Compounds 11 to 19 described in 9227, compound 47 described in JP-A-5-341441, compounds 2-10 to 11 described in JP-A-5-165147)
And azo dyes (compounds 10 to 1 described in JP-A-5-341441)
6). As a method for adding these dyes, any method such as a solution, an emulsion, a solid fine particle dispersion, and a state in which the dye is mordanted with a polymer mordant may be used. The amount of these compounds to be used is determined according to the desired absorption amount, but it is generally preferable to use them in an amount of 1 μg or more and 1 g or less per m ² of photographic material.

The heat-developable photographic material of the present invention has a support having at least one layer containing a silver salt emulsion on one side and a backing layer (back layer) on the other side. It is preferred that

In the present invention, the backing layer preferably has a maximum absorption in a desired range of about 0.3 or more and 2.0 or less. When the desired range is 750 to 1400 nm, the absorption in the visible region is preferably 0.005 or more and less than 0.5, and more preferably an antihalation layer having an optical density of 0.001 or more and less than 0.3. If the desired range is 750 nm or less, the halation is such that the maximum absorption in the desired range before image formation is 0.3 or more and 2.0 or less, and the optical density after image formation is 0.005 or more and less than 0.3. Preferably, it is a prevention layer.
The method for lowering the optical density after image formation to the above range is not particularly limited. For example, as described in Belgian Patent No. 733,706, a method in which the density by a dye is reduced by decolorization by heating, And a method of decreasing the density by decoloring by light irradiation described in JP-A-17833.

When an antihalation dye is used in the present invention, the dye may be any compound as long as it has the desired absorption in the desired range and the desired absorbance spectrum of the backing layer can be obtained.

In the present invention, suitable binders for the backing layer are transparent or translucent, generally colorless, and include natural polymer synthetic resins, polymers and copolymers, and other film-forming media such as: gelatin, gum arabic, and poly (vinyl). Alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinylpyrrolidone), casein,
Starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid),
Copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (ester) s , Poly (urethane) s, phenoxy resin, poly (vinylidene chloride), poly (epoxide) s,
Poly (carbonate) s, poly (vinyl acetate)
, Cellulose esters and poly (amide) s are preferred. The binder may be coated from water or an organic solvent or emulsion.

In the present invention, a one-sided photographic material may contain a matting agent in the surface protective layer and / or the backing layer of the photosensitive emulsion layer in order to improve transportability. Matting agent,
Generally, it is a fine particle of an organic or inorganic compound insoluble in water. Any matting agent can be used, for example, U.S. Patent Nos. 1,939,213, 2,701,245, and 2,322,
No. 037, No. 3,262,782, No. 3,539,344, No. 3,
Organic matting agents described in each specification such as 767,448,
Use well-known in the art such as inorganic matting agents described in the specifications such as 260,772, 2,192,241, 3,257,206, 3,370,951, 3,523,022, and 3,769,020. Can be. For example, specifically, examples of organic compounds that can be used as a matting agent include polymethyl acrylate, polymethyl methacrylate, polyacrylonitrile, acrylonitrile-α-methylstyrene copolymer, and polystyrene as examples of a water-dispersible vinyl polymer. , Styrene-divinylbenzene copolymer, polyvinyl acetate, polyethylene carbonate, polytetrafluoroethylene, etc., examples of cellulose derivatives such as methylcellulose, cellulose acetate, cellulose acetate propionate, and starch derivatives such as carboxy starch, carboxynitrophenyl Starch, urea-formaldehyde-starch reactant, etc.
Gelatin hardened with a known hardener and hardened gelatin coacervated into microcapsule hollow granules can be preferably used. As examples of the inorganic compound, silicon dioxide, titanium dioxide, magnesium dioxide, aluminum oxide, barium sulfate, calcium carbonate, silver chloride desensitized by a known method, silver bromide, glass, and diatomaceous earth can be preferably used. The above matting agents can be used by mixing different types of substances as necessary. The size and shape of the matting agent are not particularly limited, and those having an arbitrary particle size can be used. In practicing the present invention, it is preferable to use particles having a particle size of 0.1 μm to 30 μm. Further, the particle size distribution of the matting agent may be narrow or wide. On the other hand, since the matting agent greatly affects the haze and surface gloss of the photographic material, the particle size, shape, and particle size distribution can be adjusted as needed during the preparation of the matting agent or by mixing a plurality of matting agents. preferable.

In the present invention, it is a preferred embodiment to add a matting agent to the backing layer. The matting degree of the backing layer is preferably a Beck smoothness of 1200 seconds or less and 10 seconds or more, more preferably 700 seconds or less and 50 seconds. That is all.

In the present invention, the matting agent is preferably contained in the outermost surface layer of the photographic material, a layer functioning as the outermost surface layer, or a layer close to the outer surface. It is preferable to be contained. The matte degree of the emulsion surface protective layer may be any value as long as no stardust failure occurs, but the Beck smoothness is preferably 1,000 seconds or more and 10,000 seconds or less, and particularly preferably 2,000 seconds or less.

The photothermographic emulsion of the present invention is contained in one or more layers on a support. One layer configuration must include additional optional materials such as organic silver salts, silver halides, reducing agents and binders, and toning agents, coating aids and other auxiliaries. The two-layer construction 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 construction of a multicolor photothermographic material may include a combination of these two layers for each color, or may include all components in a single layer as described in U.S. Pat.No. 4,708,928. Is also good. In the case of a multi-dye, multi-color photothermographic material, each emulsion layer generally has a functional or non-functional layer between the emulsion layers (photosensitive layer) as described in U.S. Pat. No. 4,460,681. Are kept distinct from each other by using the barrier layer.

US Pat. Nos. 4,460,681 and 4,374,
A backside resistive heating layer as shown in US Pat. No. 921 can also be used in a photothermographic image system such as the present invention.

The heat-developable photographic emulsion of the present invention can be coated on various supports. Typical supports include polyester films, primed polyester films, poly (ethylene terephthalate) films, polyethylene naphthalate films, cellulose nitrate films, cellulose ester films, poly (vinyl acetal) films, polycarbonate films and related or resinous Including materials, as well as glass, paper, metal and the like. Flexible substrates, especially coated with baryta and / or partially acetylated α-olefin polymers, especially polymers of C 2-10 α-olefins such as polyethylene, polypropylene, ethylene-butene copolymer A paper support is typically used. The support may be transparent or opaque,
Preferably, it is transparent. 100 to 20 of these
Particularly preferred is biaxially stretched polyethylene terephthalate (PET) of about 0 μm.

The photographic material of the present invention may be, for example, a soluble salt (eg, chloride, nitrate, etc.),
Deposited metal layers, U.S. Pat.Nos. 2,861,056 and 3,206,
An ionic polymer as described in No. 312 or an insoluble inorganic salt as described in U.S. Pat.
A conductive layer containing fine particles of tin oxide described in JP-A-252349 and JP-A-57-104931 may be provided. Further, the support can be dyed if necessary.

A method for obtaining a color image using the heat-developable photographic material in the present invention is described in JP-A-7-13295, page 10, left column.
There is a method described from the 43rd line to the 11th left column, 40th line. Also, as a stabilizer for color dye images, UK Patent No. 1,326,889
No. 3,432,300, U.S. Pat.No. 3,698,909, U.S. Pat.
Nos. 3,574,627, 3,573,050, 3,764,337 and 4,042,394.

The photothermographic emulsions of the present invention can be coated by various coating operations including dip coating, air knife coating, flow coating or extrusion coating using a hopper of the type described in US Pat. No. 2,681,294. If desired, two or more layers (e.g., a combination of an emulsion layer and a surface protective layer) can be coated simultaneously by the methods described in U.S. Pat. No. 2,761,791 and GB 837,095.

In the heat-developable photographic material of the present invention, additional layers, such as a dye-receiving layer for receiving a moving dye image, an opaque layer if reflective printing is desired, a protective topcoat layer and photothermographic techniques It may include a known primer layer and the like. The photographic material of the present invention is preferably capable of forming an image with only one photographic material, and it is preferable that a functional layer required for image formation such as an image receiving layer does not become another photographic material.

Although the heat-developable photographic material of the present invention may be developed by any method, it is usually developed by elevating the temperature of the heat-developable photographic material exposed imagewise. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 14 ° C.
0 ° C. The development time is preferably from 1 to 180 seconds,
10 to 90 seconds is more preferred.

The method of exposing the photographic material of the present invention is not particularly limited. A known method using a tungsten lamp, a mercury lamp, a laser light source, a CRT light source, a xenon lamp, an iodine lamp, or the like can be used. Among these, a method using a laser light source is particularly preferred.

The heat-developable photographic material of the present invention has a low haze upon exposure and tends to cause interference fringes. Examples of this interference fringe prevention technology include a technology disclosed in Japanese Patent Application Laid-Open No. HEI 5-113548 for obliquely entering a laser beam into a photographic material, and a multi-mode laser disclosed in WO95 / 31754 and the like. There is known a method of utilizing these techniques, and it is preferable to use these techniques.

To expose the photothermographic material of the present invention, use SP
IE vol.169 Laser Printing 116-128 (1979),
As disclosed in JP-A-4-51043 and WO95 / 31754, it is preferable to expose the laser beams so that they overlap each other so that the scanning lines are not visible.

[0152]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. Example 1 Application samples 101 to 126 were prepared as described below, and the effects of the present invention were confirmed.

(Preparation of Organic Silver Dispersion-A) 40 g of behenic acid
7.3 g of stearic acid and 500 ml of water were stirred at a temperature of 90 ° C. for 15 minutes, 187 ml of 1N NaOH was added over 15 minutes, 61 ml of a 1N aqueous nitric acid solution was added, and the temperature was lowered to 50 ° C. Next, 124 ml of a 1N silver nitrate aqueous solution was added over 2 minutes, and the mixture was stirred as it was for 30 minutes. Then, the solid content is separated by suction filtration, and the conductivity of the filtrate is measured.
The solid content was washed with water until it reached 30 μS / cm. The solid content thus obtained was handled as a wet cake without drying, and 10 g of polyvinyl alcohol (trade name: PVA-205) and water were added to a wet cake equivalent to 100 g of dry solid content to make the total amount 500 g. It was pre-dispersed with a homomixer.

Next, the pre-dispersed stock solution is dispersed in a dispersing machine (trade name: Microfluidizer M-110S-EH, manufactured by Microfluidics International Corporation, using G10Z interaction chamber).
The pressure was adjusted to 1750 kg / cm ² , and the mixture was treated three times to complete the preparation of a silver salt of organic acid microcrystal dispersion having a volume-weighted average diameter of 0.93 μm. Particle size measurements are available from Malvern Instruments
Ltd. MasterSizerX.

(Preparation of silver halide grains-A) 22 g of phthalated gelatin and 30 mg of potassium bromide were dissolved in 700 ml of water, the pH was adjusted to 5.0 at a temperature of 40 ° C., and 159 ml of an aqueous solution containing 18.6 g of silver nitrate was added. The aqueous potassium bromide solution was added over 10 minutes by a controlled double jet method while maintaining the pAg at 7.7. Then, 476 ml of an aqueous solution containing 55.4 g of silver nitrate and an aqueous solution containing 8 μmol / liter of dipotassium hexachloride iridate and 1 mol / liter of potassium bromide are added over 30 minutes by a controlled double jet method while maintaining the pAg at 7.7. did. After that, the pH was lowered to perform coagulation sedimentation and desalting treatment, and 0.1 g of phenoxyethanol was added.
Adjusted to 8.0. The resulting particles have an average particle size of 0.07μ
m, cubic grains having a projected area diameter variation coefficient of 8% and a (100) face ratio of 86%.

The temperature was adjusted to 6 with respect to the prepared silver halide grains A.
Raise the temperature to 0 ° C and use sodium thiosulfate 85μ per mole of silver.
Mole, 2,3,4,5,6-pentafluorophenyldiphenylphosphine selenide, 11 μmol, 2 μmol of the following tellurium compound 1, 3.3 μmol of chloroauric acid, thiocyanic acid
230 μmol was added and aged for 120 minutes.

Thereafter, the temperature was changed to 40 ° C. and the following sensitizing dye
A was added to the silver halide at 3.5 × 10 ^-4 mol with stirring, and after 5 minutes, the following compound A was added to the silver halide in an amount of 4.
After adding 6 × 10 ⁻³ mol and stirring for 5 minutes, the mixture was rapidly cooled to 25 ° C. to complete the preparation of silver halide grains A.

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[0159]

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(Preparation of Material Solid Fine Particle Dispersion) Tetrachlorophthalic acid, 1,1-bis (2-hydroxy-3,5
-Dimethylphenyl) -3,5,5-trimethylhexane, tribromomethylphenylsulfone, and 5-heptyl-4-phenyl-3-mercapto-1,2,4-triazole were prepared as solid fine particle dispersions. 0.81 g of hydroxypropylmethylcellulose and 94.2 ml of water were added to tetrachlorophthalic acid, stirred well, and left as a slurry for 10 hours. Thereafter, 100 ml of zirconia beads having an average diameter of 0.5 mm was prepared, put in a vessel together with the slurry, and dispersed with a dispersing machine (1 / 4G sand grinder mill: manufactured by Imex Co., Ltd.) for 5 hours to prepare tetrachlorophthalic acid. A solid fine particle dispersion was obtained. The particle size is 70wt% 1.
It was not more than 0 μm and not less than 0.1 μm. For other materials, the amount of the dispersant used and the dispersion time were changed to obtain the desired average particle size, and solid fine particle dispersions were obtained for each material.

<< Preparation of Dispersion of Polymer Fine Particles Containing Dye >> A solution comprising the following dye A (2 g), methyl methacrylate-methacrylic acid copolymer (85:15) (6 g) and 40 ml of ethyl acetate was heated to 60 ° C. After heating and dissolving,
High-speed stirrer (homogenizer, manufactured by Nippon Seiki Seisakusho) in addition to 100 ml of an aqueous solution containing 5 g of polyvinyl alcohol
At 12,000 rpm for 5 minutes to obtain an emulsified dispersion P of fine polymer particles having an average particle diameter of 0.3 μm.

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(Preparation of Emulsion Layer Coating Solution-1) Silver halide grains-A were added to the previously prepared organic silver microcrystal dispersion-A (corresponding to 1 mol of silver) with 10 mol% of silver halide / organic acid. Emulsion coating liquid-1 was prepared by adding silver equivalents, the following binder and developing materials.

Binder: Luckstar 3307B (manufactured by Dainippon Ink and Chemicals, Incorporated; SBR latex) 430 g Material for development: Dispersion equivalent to 5 g of tetrachlorophthalic acid 1,1-bis (2-hydroxy-3,5) -Dimethylphenyl) -3,5,5-trimethylhexane The above-mentioned dispersion corresponding to 98 g of the compound of the general formula (I) of the present invention or a comparative compound added as shown in Table 1 The general formula (II) of the present invention Or the comparative compound added as shown in Table 1 Tribromomethylphenylsulfone 12 g of the above-mentioned dispersion 5-heptyl-4-phenyl-3-mercapto-1,2,4-triazole 6.4 g of the above-mentioned dispersion 4-methylphthalic acid 7 g Dye: Dye A, 4 g equivalent of the above-mentioned dye-containing polymer fine particle dispersion

The rack star 3307B used above
Is a polymer latex of a styrene-butadiene copolymer, and the average particle size of the dispersed particles is 0.1 to 0.1.
It is about 5 μm. The equilibrium water content of the polymer at 25 ° C. and 60% RH was 0.6 wt%.

(Preparation of Coating Solution for Emulsion Surface Protective Layer) For 10 g of inert gelatin, 0.26 g of surfactant A and surfactant B were added.
0.09 g, silica fine particles (average particle size 2.5 μm) 0.9 g,
1,2- (bisvinylsulfonylacetamido) ethane
0.3 g and 64 g of water were added to form a surface protective layer.

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(Preparation of Dye Dispersion) To 35 g of ethyl acetate, 0.8 g of the following dye B was added and dissolved by stirring. 85 g of a 6% by weight solution of polyvinyl alcohol (PVA-217) previously dissolved in the solution was added, and the mixture was stirred with a homogenizer for 5 minutes. Thereafter, the ethyl acetate was volatilized by removing the solvent, and finally diluted with water to prepare a dye dispersion.

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(Preparation of Solid Base Fine Particle Dispersion) To 26 g of the following solid base, polyvinyl alcohol (PVA-
215) 234 g of a 2 g aqueous solution was added, stirred well, and left as a slurry for 10 hours. After that, average diameter 0.5mm
Was prepared in a vessel together with the slurry, and dispersed in a dispersing machine (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) for 5 hours to obtain a solid base fine particle dispersion.

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(Preparation of back surface coating solution) The dye dispersion 20 prepared above was added to 38 g of a 10% by weight gelatin solution.
g, 20 g of solid base fine particle dispersion and 35 g of water were added to obtain a back surface coating solution.

(Preparation of back surface protective layer coating solution) For 10 g of inert gelatin, 0.26 g of the above-mentioned surfactant A, 0.09 g of surfactant B, and 0.3 g of 1,2- (bisvinylsulfonylacetamide) ethane 0.4 g of Sildex H121 (spherical silica manufactured by Dokai Chemical Co., average size 12 μm)
64 g of water was added to form a back surface protective layer.

(Preparation of Coated Sample) The emulsion layer coating solution-1 prepared as described above was coated with a dye added to a photosensitive layer on a 175 μm polyethylene terephthalate support at a silver amount of 2.2 g / m ^2.
After coating, the emulsion surface protective layer coating solution was coated on the emulsion coating layer so that the coating amount of gelatin was 1.8 g / m ² . After drying, a coating solution for the back surface was applied on the surface opposite to the emulsion layer so that the coating amount of Dye B was 56 mg / m ^2, and a coating solution for the back surface protective layer was further coated on the back surface coating layer. Samples were prepared by coating so that the coating amount was 1.8 g / m ² (Table 1).

(Evaluation of maximum density, minimum density, sensitivity) 660 n
After exposing the coated sample with a laser sensitometer equipped with a m-diode, it was developed at 120 ° C. for 15 seconds, and the obtained image was evaluated with a densitometer. On the basis of the measurement results, the reciprocal of the ratio of the exposure amount giving a density higher than the minimum density by 1.0 was evaluated as the sensitivity. The results are shown as relative values when the sensitivity of Sample 101 is 100.

(Evaluation of surface quality of sample)
It was cut to 10 cm × 10 cm, the number of lumps formed on the emulsion surface contained therein was counted, and the surface quality was evaluated according to the following evaluation criteria. ◎ and ○ are practically acceptable. ◎: Number of occurrences, 0 to 5 ○: Number of occurrences, 6 to 20 △: Number of occurrences, 21 to 100 ×: Number of occurrences, 101 or more

(Evaluation of Silver Tone After Development) The coated sample was exposed through a step wedge, developed at 120 ° C. for 15 seconds, and the obtained developed sample was observed through white light. In the evaluation, the degree of deviation from the black color tone, which is considered to be practically preferable, was sensory evaluated according to the following evaluation criteria. ◎ is practically acceptable. A: Recognized as black. …: Black, but slightly red or brown. Δ: Brown, yellow, red, etc. are recognized depending on the exposure amount. X: recognized as brown, yellow, red, etc.

Table 1 summarizes the evaluation results. The structural formulas of the comparative compounds in the table are as follows.

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[Table 1]

[0181]

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The following can be seen from the results in Table 1. Sample 1
01 contains only the compound represented by the general formula (I) of the present invention and does not contain the compound represented by the general formula (II). This sample has a relatively high maximum density, but the silver tone is reddish. In Sample 105, the amount of the compound represented by Formula (I) was increased, but the maximum density and sensitivity were increased, but the level of silver tone was not sufficiently satisfactory. Sample 102 contains only the compound represented by the general formula (II) of the present invention and does not contain the compound represented by the general formula (I). This sample has slightly lower sensitivity and lower maximum concentration. The silver tone is reddish-brown. On the other hand, the compound represented by the general formula (I) and the compound represented by the general formula (I
It can be seen that the samples (for example, Samples 103 and 104) in which the compound represented by I) is used in combination have a high maximum concentration, high sensitivity, and are also excellent in silver tone.

Samples 111 to 114 are a combination of a comparative compound outside the scope of the present invention and a compound represented by the general formula (II) of the present invention. Among these, by comparing Sample 115 with Samples 111 and 112, it can be seen that the combined use of the compound represented by the general formula (II) of the present invention increases sensitivity and increases the maximum concentration. It can be seen that almost no improvement in silver tone, which is an effect of the present invention, is observed. Further, those using the compound for comparison have a poor silver tone and low sensitivity and maximum density. Sample 126 is a mixture of the compound represented by the general formula (I) of the present invention and a comparative compound outside the scope of the present invention. By comparing with Samples 101 and 103, Sample 103, which was used in combination with the compound represented by the general formula (II) of the present invention, has improved silver tone and sensitivity over Sample 101. It can be seen that Sample 126 to which Compound C-2 was added had no effect on the improvement of silver tone, which is the effect of the present invention.

From the above results, only when the compound represented by the general formula (I) and the compound represented by the general formula (II) were used in combination, a high sensitivity and a high maximum density were obtained, and the silver tone Good samples were obtained, and the effect of the present invention is clear.

Example 2 The 4-methylphthalic acid of the emulsion layer coating solution-1 of Example 1 was replaced with
Emulsion layer coating solution-2 and emulsion layer coating solution-3 were prepared by substituting phthalic acid and 4-methoxyphthalic acid, respectively. Using this emulsion layer coating solution, a coating sample 201 was prepared from emulsion layer coating solution-2 in the same manner as in Example 1.
-Coating Samples 301 to 326 were prepared from Emulsion Layer Coating Solution-3. These coated samples were evaluated in the same manner as in Example 1.

As a result, the coating samples 203, 204, 206 of the present invention
~ 210,216 ~ 225 and coating sample 303,304,306 ~ 310,316
325325 had higher maximum density, higher sensitivity and better silver tone than the comparative sample.

[0187]

According to the present invention, it can be seen that a heat-developable photographic material having a good silver tone, a high sensitivity and a high maximum density can be produced.

Claims (3)

[Claims] (1) a reducible silver salt, (b) a reducing agent,
(C) a binder, (d) at least one compound represented by the following general formula (I), and (e) a compound represented by the following general formula (I
A heat-developable photographic material comprising at least one compound represented by the formula (I). Embedded image [In the general formula (I), R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ each independently represent a hydrogen atom or a monovalent substituent, and these substituents are bonded to each other to form a ring. May be formed. ] [In the general formula (II), Z represents a group of non-metallic atoms necessary to form a heteroaromatic ring containing at least one oxygen atom or sulfur atom. R ₂₁ and R ₂₂ represent a hydrogen atom or a monovalent substituent. ] 2. The photothermographic material according to claim 1, which contains a photosensitive silver halide as a photocatalyst. 3. The photothermographic material according to claim 1, which comprises at least one compound represented by the following general formula (III). Embedded image [In the formula, T represents a monovalent substituent, and k represents an integer of 0 or more and 4 or less. k = 0 represents all hydrogen atoms,
When k ≧ 2, a plurality of Ts may be the same or different, and may combine with each other to form a ring. M ₁ and M ₂ each represent a hydrogen atom or a cation. ]