JP2000258870A - Heat-developable photosensitive material and methods for imagewise exposing and forming image by using same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the heat-developable photosensitive material freed of rise of fog and drop of sensitivity in storage in a state of high sensitivity and sensitive to infrared rays. SOLUTION: The heat-developable photosensitive material contains at least (a) an insensitive organic silver salt, (b) silver halide spectrally sensitized with an infrared sensitizing dye, (c) a reducing agent capable of reducing the silver ions of organic silver salt when it is activated by heat, and (d) a binder on a support, and it contains further, a compound represented by the formula R-SM in which R is an acyclic aliphatic or heteroaliphatic cyclic or aromatic group; and M is an H or alkali metal atom or a quarternary ammonium group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a photothermographic material,
In particular, the present invention relates to an infrared-sensitive photothermographic material which has a high infrared sensitivity and does not cause an increase in fog or a decrease in sensitivity when stored for a long period of time.

[0002]

2. Description of the Related Art A silver halide photographic light-sensitive material is produced using silver halide fine particles having excellent characteristics such as high photosensitivity, memory, and high S / N characteristics. However, since the photosensitive region of silver halide grains has a short wavelength near 500 nm, which is a long-wave end, spectral sensitization using a dye is indispensable for exposing to longer wavelengths. In particular, in recent years, with the development of light sources, photosensitive materials sensitive to infrared laser wavelengths have become increasingly important in industrial recording materials. Further, among the photographic recording materials, infrared light-sensitive materials which are excellent in use for recording environmental information or in improving depiction performance have been attracting attention.

[0003] A large number of compounds have been known as spectral sensitizing dyes (which may be simply referred to as sensitizing dyes) used for this purpose. For example, the theory of the theory of the theory by TJ James・ Photographic Process ”, 4th edition (1977, Macmillan, NY)
p. 194-234, Francis M. Harmer, "The Cyanine Soy and Related Compounds" (1964, John Willy and Sons, NY); Dee M. Sturmer, "The Chemistry" -Heterocyclic Compounds, Volume 30 "p. 441- (1977, John Willy
And Sons, N.M. Y. ), JP-A-3-13838
Nos. 3-163440, 5-72660, and 5
Nos. -72661, 5-88292 and 8-1942
No. 82, No. 9-166844, No. 9-281631
Nos. 9,292,672, 9,292,673, and 10-73900, and U.S. Pat.
No. 900, No. 3,582,344, No. 4,53
No. 6,473, No. 4,740,455, No. 4,8
Cyanine dyes and merocyanines described in specifications such as 35,096, 5,393,654, British Patent 774,779, European Patents 420,012, 821,811 and the like. Various dyes such as dyes are known.

[0004] These spectral sensitizing dyes must not only extend the photosensitive wavelength range of the silver halide emulsion but also satisfy the following conditions.

1) The spectral sensitization range is appropriate.

2) High spectral sensitization efficiency.

3) No adverse interaction with other additives, for example, stabilizers, antifoggants, coating aids, high-boiling solvents, etc.

4) To not adversely affect the characteristic curve such as fogging and gamma change.

5) The silver halide photographic light-sensitive material containing a photosensitive dye should not change its photographic performance such as fog when aged (especially when stored under high temperature and high humidity).

6) The added photosensitive dye does not diffuse into layers having different photosensitive wavelength ranges and does not cause color turbidity.

7) After the development and fixing, the photosensitive dye is not removed after washing with water to cause no color contamination.

However, the spectral sensitizing dyes disclosed hitherto have not yet reached a level which sufficiently satisfies all of these conditions. In particular, dyes having a maximum absorption in the infrared region have long conjugate chains and are easily affected by the environment, or the distance between the lowest vacant level and the highest occupied level is narrow and the conduction band level of silver halide grains is small. Since the lowest empty level and the highest occupied level are close to each other, there arises a problem that fog is easily generated and sensitivity is lowered. Accordingly, an infrared-sensitive silver halide emulsion having high sensitivity, low fog, and little change in performance even with time has been desired.

[0013] From this point of view, many infrared sensitizing dyes have been searched so far, but as another method for improving the performance of these infrared sensitizing dyes, sensitizing dyes themselves are used. Apart from the structure search described above, there is known a method for improving the sensitivity by a method using a supersensitizer or reducing the above-mentioned fluctuation in performance. The role of supersensitizers is thought to be to control the spectral sensitization performance by improving the aggregation and adsorption of infrared sensitizing dyes to the silver halide surface when used in combination with sensitizing dyes. ing. Numerous combinations of sensitizing dyes and supersensitizers have been found and proposed in silver halide light-sensitive materials, and as supersensitizers are typically mercapto-substituted heteroaromatic compounds, For example, 2-mercaptobenzimidazole, 2-mercaptobenzimidazole,
Compounds such as mercaptobenzoxazole and 2-mercaptobenzothiazole are well known. However, the effects of these supersensitizers are limited to combinations with specific sensitizing dyes, and particularly in the case of infrared sensitizing dyes, there are not many good sensitizers as supersensitizers. Not much has been considered. Also, when these well-known supersensitizers are used in a photothermographic material, the sensitizing performance is unstable or the sensitivity is low, and when the photothermographic material is stored for a long time, There is a disadvantage that the sensitivity is lowered, and this has been one of the problems in applying the infrared sensitizing dye to the photothermographic material.

[0014]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an infrared-sensitive photothermographic material which does not increase in fog or decrease in sensitivity when stored at high sensitivity.

[0015]

The present invention is achieved by the following means.

1. At least a) a non-photosensitive organic silver salt on a support; b) silver halide spectrally sensitized by an infrared sensitizing dye; c) reduction of silver ions of said organic silver salt when activated by heat A photothermographic material comprising a reducing agent and d) a binder, further comprising a compound represented by the following general formula (I):
A photothermographic material comprising a compound represented by the formula:

In the formula (I) R-SM, R represents an acyclic aliphatic group, a heteroalicyclic group or an aromatic group. M represents hydrogen, an alkali metal, or a quaternary ammonium group.

2. When the silver halide has the following general formula (1)
(4) The photothermographic material as described in (1) above, which is spectrally sensitized with at least one sensitizing dye selected from (4).

[0019]

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In the general formulas (1) to (4), Y ₁ , Y ₂ ,
Y ₁₁ , Y ₂₁ , Y ₂₂ and Y ₃₁ each represent an oxygen atom, a sulfur atom, a selenium atom, a —C (R _a ) (R _b ) — group, or —CH
= CH- represents a group, Z ₁ represents a nonmetallic atomic group necessary for forming a condensed ring of 5- or 6-membered. R is a hydrogen atom, a lower alkyl group, a cycloalkyl group, an aralkyl group, a lower alkoxy group, an aryl group, hydroxy group, a halogen atom, R _a and R _b are each a hydrogen atom, a lower alkyl group or R _a and R represents a group of nonmetallic atoms necessary for forming a 5- or 6-membered aliphatic spiro ring by bonding between _b .
R ₁ , R ₁₁ , R ₂₁ , R ₂₂ , R ₃₁ and R ₃₂ are each an aliphatic group, or R ₁ is required to form a fused ring with W ₃ and R ₁₁ with W ₁₄ Represents a group of non-metallic atoms. R _c and R _d each represent a lower alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, or a heterocyclic group. W ₁ , W ₂ , W ₃ ,
_{W 4, W 11, W 12} , W 13, W 14, W 21, W 22, W 23, W
₂₄ , W ₃₁ , W ₃₂ , W ₃₃ and W ₃₄ are each a hydrogen atom, a substituent or W ₁ is W ₂ , W ₁₁ is W ₁₂ , W ₂₁ is W ₂₂ ,
W ₂₃ and W _24, W ₃₁ and W _32, W ₃₃ represents a nonmetallic atomic group necessary to form a fused ring bond between W _34. V
Each _{1 ~V 9, V 11 ~V 13} , V 21 ~V 29, V 31 ~V 33,
Hydrogen atom, halogen atom, amino group, alkylthio group,
Arylthio group, lower alkyl group, lower alkoxy group,
Represents an aryl group, an aryloxy group, a heterocyclic group, or V ₁ is V ₃ , V ₂ is V ₄ , V ₃ is V ₅ , V ₄ is V ₆ ,
V ₅ and V _7, V ₆ and V _8, V ₇ and V _9, V ₁₁ and V _13,
And V ₂₁ and V _23, V ₂₂ and V _24, V ₂₃ and V _25, V ₂₄ and V
_26, a V ₂₅ is V _27, and V ₂₆ are V _28, V ₂₇ and V _29, V
₃₁ represents a non-metallic atomic group necessary for forming a 5- to 7-membered coupled between V _33, either any one, and V ₁₁ ~V ₁₃ of V ₁ ~V ₉ One is a group other than a hydrogen atom. X
₁ , X ₁₁ , X ₂₁ and X ₃₁ each represent an ion necessary for canceling an intramolecular charge, and
31 represents the number of ions required to cancel the charge in the molecule. k1, k2, k21 and k22 each represent 0 or 1. n21, n22, n31 and n32 each represent an integer of 0 to 2, and n21, n22 and n31
And n32 do not become 0 at the same time. p1 and p11
Is each 0 or 1, q1 and q11 are each an integer of 1 and 2, and the sum of p1 and q1 and the sum of p11 and q11 does not exceed 2.

3. 3. The photothermographic material according to the above item 1 or 2, comprising a compound represented by the following general formula (A) or (B).

[0022]

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In the formula, Hal ₁ and Hal ₂ represent a halogen atom. Hal ₁ and Hal ₂ may be the same or different. X represents an anionic group. R ₁ represents a group having a carbonyl group as a partial structure, and R ₂ and R ₃ represent a substituent which can be substituted on a nitrogen atom or a hydrogen atom. R _{1 to} R ₃ do not bond to each other so as to form a ring structure in which the nitrogen atom becomes an inner ring atom. n represents 1 or 2.

[0024]

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In the formula, Hal ₃ and Hal ₄ represent a halogen atom. Hal ₃ and Hal ₄ may be the same or different. Z represents an atomic group necessary for constructing a 5- to 7-membered nitrogen-containing heterocycle together with an adjacent nitrogen atom.
This nitrogen-containing hetero ring may be condensed with another ring, or may be bonded by a bonding group.

4. The exposure of the photothermographic material according to the above item 1, 2 or 3 by using a laser scanning exposure device in which the angle between the exposure surface of the photothermographic material and the scanning laser beam does not become substantially perpendicular. Characteristic image exposure method.

5. 4. An image exposure method, wherein the photothermographic material described in 1, 2, or 3 is exposed by a laser scanning exposing machine in which a scanning laser beam is a vertical multi-scan.

6. 4. An image forming method, wherein the photothermographic material according to the above item 1, 2 or 3 is heated and developed in a state where the photothermographic material contains a solvent in an amount of 5 to 1000 mg / m < ² >.

Hereinafter, the present invention will be described in detail.

Infrared dyes generally have low adsorptivity, and it is a major problem to improve sensitivity by improving the adsorptivity. Particularly, a binder system of a photothermographic material is disadvantageous in terms of adsorption, so that an efficient supersensitizer has been further required. As a result of intensive studies, the present inventors have found that a compound represented by the following general formula (I) has a high effect in an infrared-sensitive photothermographic material, and have accomplished the present invention. It is. That is, when these supersensitizers are used, higher sensitivity and fluctuation in sensitivity when the photosensitive material is stored for a long period of time are greatly improved as compared with those known as conventional supersensitizers.

The compound represented by formula (I) will be described.

Formula (I) R-SM In the formula, R represents an aliphatic group, a heteroalicyclic group, or an aromatic group, and may be substituted with a suitable substituent.

Examples of the aliphatic group for R include a linear or branched alkyl group, alkenyl group, alkynyl group and cycloalkyl group.

The alkyl group has from 1 to 18 carbon atoms, such as methyl, ethyl, propyl, butyl, hexyl, decyl, dodecyl, isopropyl, t-butyl, 2-ethylhexyl. And the like.

The alkenyl group may have 2 to 2 carbon atoms.
0, such as an allyl group, a 2-butenyl group, and a 7-octenyl group.

The alkynyl group may have 2 to 2 carbon atoms.
0, such as a propargyl group and a 2-butynyl group.

The cycloalkyl group may have 3 carbon atoms.
To 12, for example, a cyclopropyl group, a cyclohexyl group, a cyclododecyl group and the like.

The aromatic group represented by R has 6 to 2 carbon atoms.
0, for example, a phenyl group and a naphthyl group.

The heteroalicyclic group represented by R is a 3- to 7-membered ring composed of a combination of at least one atom selected from nitrogen, oxygen or sulfur and carbon, and may be condensed with a benzene ring. Good.

Examples of the substituent which can be substituted for R include an alkyl group (having 1 to 18 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group and a decyl group), and an alkenyl group (a carbon atom). With 2-20 atoms,
For example, an allyl group, a 2-butenyl group, etc., an alkynyl group (having 2 to 20 carbon atoms, for example, a propargyl group, 2-butynyl group, etc.), a cycloalkyl group (having 3 to 12 carbon atoms) For example, a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, etc.), an aryl group (having 6 to 10 carbon atoms, for example, a phenyl group),
A halogen atom (for example, fluorine, chlorine, bromine, iodine, etc.), an alkoxy group (having 1 to 10 carbon atoms, for example, a methoxy group, an ethoxy group, a hexyloxy group, etc.), an aryloxy group (for 6 to 6 carbon atoms) 10, a phenoxy group), a carboxyl group, an alkoxycarbonyl group (having 2 to 20 carbon atoms, such as a methoxycarbonyl group and an ethoxycarbonyl group),
An aryloxycarbonyl group (having 7 to 11 carbon atoms, for example, a phenoxycarbonyl group), an amino group,
Imino group, acyl group (having 1 to 20 carbon atoms, for example, acetyl group), carbamoyl group, hydroxy group, acyloxy group (having 2 to 20 carbon atoms, for example, acetoxy group), aryloyloxy group (Having 7 to 11 carbon atoms, for example, benzoyloxy group), amide group (having 1 to 20 carbon atoms, for example, acetamido group, benzamide group), sulfo group, and sulfonyl group (having 1 to 11 carbon atoms) 12, for example, a methanesulfonyl group, a benzenesulfonyl group, etc.), an alkylthio group (having 1 to 20 carbon atoms, for example, a methylthio group,
An ethylthio group), an arylthio group (having 6 to 10 carbon atoms)
For example, a phenylthio group), a sulfamoyl group, a sulfonamide group (having 1 to 20 carbon atoms,
For example, a methanesulfonamide group, a benzenesulfonamide group, etc., a ureido group (having 1 to 20 carbon atoms, such as a methylureido group, a phenylureido group, etc.), and a thioureido group (having 1 to 20 carbon atoms,
Examples thereof include a methylthioureido group and a phenylthioureido group, a thioamide group (having 1 to 20 carbon atoms, such as a thioacetamide group and a thiobenzamide group), a cyano group, and a nitro group. Examples of the group that can be substituted for R include a substituent such as an imino group and a thione group, for example, when R is alkyl, the alkyl skeleton contains an imino group or a thione group. R may have one or more substituents among these substituents. Further, each substituent may be further substituted with these substituents.

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

[0042]

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[0043]

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[0044]

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These supersensitizers according to the present invention are preferably used in the emulsion layer containing the organic silver salt and silver halide grains in the range of 0.001 to 1.0 mol per mol of silver. In particular, it is preferably 0.01 to 0.1 / mol silver.
An amount in the range of 5 moles is preferred.

The supersensitizer of the present invention is particularly effective when it is an infrared sensitizing dye. Examples of the infrared spectral sensitizing dye used for these include, for example, US Pat.
No. 73, No. 4,515,888, No. 4,959,
No. 294, 5,393,654 and the like.

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

In the general formulas (1) to (4), Y ₁ ,
Y ₂ , Y ₁₁ , Y ₂₁ , Y ₂₂ and Y ₃₁ are each an oxygen atom,
Represents a sulfur atom, a selenium atom, a —C (R _a ) (R _b ) — group, or a —CH ＝ CH— group, and Z ₁ represents a non-metal required for completing a 5- or 6-membered condensed ring. Represents an atomic group. R is a hydrogen atom, a lower alkyl group, a cycloalkyl group, an aralkyl group, a lower alkoxy group, an aryl group, hydroxy group, a halogen atom, R _a and R _b are each a hydrogen atom, a lower alkyl group or R _a and R _b is joined by 5 members,
Represents a group of non-metallic atoms necessary to form a 6-membered aliphatic spiro ring. R ₁ , R ₁₁ , R ₂₁ , R ₂₂ , R ₃₁ and R ₃₂ are each an aliphatic group, or R ₁ is required to form a fused ring with W ₃ and R ₁₁ with W ₁₄ Represents a group of non-metallic atoms. R _c
And R _d are each a lower alkyl group, a cycloalkyl group,
Represents an aralkyl group, an aryl group, or a heterocyclic group. W ₁ ,
W ₂ , W ₃ , W ₄ , W ₁₁ , W ₁₂ , W ₁₃ , W ₁₄ , W ₂₁ ,
_{W 22, W 23, W 24} , W 31, W 32, W 33 and W ₃₄ each,
A hydrogen atom, a substituent or W ₁ is W ₂ , W ₁₁ is W ₁₂ ,
W ₂₁ and W _22, W ₂₃ and W _24, W ₃₁ and W _32, W ₃₃ is W
Represents a group of non-metallic atoms necessary for forming a condensed ring by bonding with ₃₄ . _{V 1 ~V 9, V 11 ~V} 13, V 21 ~V 29, V 31
To V ₃₃ each represent a hydrogen atom, a halogen atom, an amino group, an alkylthio group, an arylthio group, a lower alkyl group, a lower alkoxy group, an aryl group, an aryloxy group, a heterocyclic group, or V ₁ is V ₃ V ₂ is V ₄ and V ₃ is V
And _5, V ₄ and V _6, V ₅ and V _7, V ₆ and V _8, V ₇ is V ₉
When, and V ₁₁ is V _13, and V ₂₁ are V _23, V ₂₂ and V _24, V ₂₃
Is V ₂₅ , V ₂₄ is V ₂₆ , V ₂₅ is V ₂₇ , V ₂₆ is V
₂₈ , V ₂₇ represent V ₂₉ and V ₃₁ represent a group of nonmetallic atoms necessary for forming a 5- to 7-membered ring by bonding between V ₂₉ and V ₃₃ ;
₁ any one of any one and V ₁₁ ~V ₁₃ of ~V ₉ is a group other than a hydrogen atom. X ₁ , X ₁₁ , X ₂₁ and X ₃₁ each represent an ion necessary for canceling an intramolecular charge;
1, 111, 121 and 131 each represent the number of ions required to cancel the charge in the molecule. k1, k2, k2
1 and k22 each represent 0 or 1. n21, n2
2, n31 and n32 each represent an integer of 0 to 2,
n21 and n22 and n31 and n32 never become 0 at the same time. p1 and p11 are each 0 or 1, and q
1 and q11 are integers of 1 and 2, respectively, and p1 and q
1 and the sum of p11 and q11 does not exceed 2. More preferred structures among the general formulas (1) and (2) are represented by the general formulas (1-1) and (2-1).

[0049]

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In the general formulas (1-1) and (2-1),
Y ₁ , Y ₂ and Y ₁₁ each represent an oxygen atom, a sulfur atom, a selenium atom, a —C (R _a ) (R _b ) — group or —CH ＝ CH—
Z ₁ represents a group of non-metallic atoms required to complete a 5- or 6-membered fused ring. R is a hydrogen atom, a lower alkyl group, a cycloalkyl group, an aralkyl group, a lower alkoxy group, an aryl group, Hidokishi group, a halogen atom, each R _a and R _b, hydrogen atom, a lower alkyl group,
Alternatively, it represents a group of non-metallic atoms necessary for forming a 5- or 6-membered aliphatic spiro ring by bonding between _Ra and _Rb . R ₁ and R
₁₁ represents an aliphatic group, or R ₁ represents W ₃ and R ₁₁ represents a group of non-metallic atoms necessary for forming a condensed ring with W ₁₄ .
W ₁ , W ₂ , W ₃ , W ₄ , W ₁₁ , W ₁₂ , W ₁₃ and W ₁₄ are each a hydrogen atom, a substituent or W ₁ is W ₂ and W ₁₁ is W ₁₂
And W ₁₃ represents a group of nonmetallic atoms necessary for forming a condensed ring by bonding with W ₁₄ . L _{1 to} L ₉ and L _{11 to} L ₁₅ each represent a methine group. X ₁ and X ₁₁ each represent an ion required to cancel the charge in the molecule, and 11 and 111 each represent the number of ions required to cancel the charge in the molecule. m1 to m3 each represent 0 or 1. p1 and p1
1 is each 0 or 1, q1 and q11 are each 1
Or, the sum of p1 and q1 and p11 and q11 does not exceed 2.

Each substituent will be described in more detail.

The general formulas (1), (1-1),
The substituents of the compounds represented by (2-1), (3) and (4) are described below.

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

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

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

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

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

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

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

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

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

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

W ₁ and W ₂ , W ₃ and W ₄ , W ₁₁ and W ₁₂ , W ₁₃ and W ₁₄ , W ₂₁ and W ₂₂ , W ₂₃ and W ₂₄ , W ₃₁ and W ₃₂ , R ₃₁ and W ₃₂ , R ₃₃ and R
₃₄ each as a fused ring which can be formed by connecting together, for example, 5-membered, and a fused carbocyclic 6-membered saturated or unsaturated. These condensed rings can have a substituent at any position, and examples of these substituents include the groups described above as the groups that can be substituted with the aliphatic group.

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

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

Also, V ₁ and V ₃ , V ₂ and V ₄ , V ₃ and V ₅ , V ₄
And V _6, V ₅ and V _7, V ₆ and V _8, V ₇ and V _9, V ₁₁ and V _13, V
₂₁ and V ₂₃ , V ₂₂ and V ₂₄ , V ₂₃ and V ₂₅ , V ₂₄ and V ₂₆ , V ₂₅
And V ₂₇ , V ₂₆ and V ₂₈ , V ₂₇ and V _29, and a 5- to 7-membered ring formed by bonding between V ₃₁ and V ₃₃ include, for example,
Examples thereof include a cyclopentene ring, a cyclohexene ring, a cycloheptene ring, and a decalin ring, and these rings can be substituted with a lower alkyl group, a lower alkoxy group, or an aryl group described for R.

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

[0068] wherein R _g is a lower alkyl group, an aryl group or a heterocyclic group described for R group described above, -SR _g
Specific examples of the group include a methylthio group, an ethylthio group, a benzylthio group, a phenylthio group, a tolylthio group, and the like.

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

The formulas (1), (1-1) and (2-
In the compounds represented by (1), (3) and (4), when a group having a cation or anion charge is substituted, an equivalent amount of an anion or cation is used so that the intramolecular charge is offset. Forms a counter ion. For example,
Specific examples of the cation necessary for canceling the intramolecular charge represented by X ₁ , X ₁₁ , X ₂₁ , X ₃₁ , X _41, and X ₅₁ include a proton and an organic ammonium ion (for example, , Triethylammonium, triethanolammonium, pyridinium, etc.), inorganic cations (eg, cations such as lithium, sodium, potassium, etc.). Specific examples of acid anions include, for example, halogen ions (eg, chloride ions, Bromide ion, iodine ion, etc.), p-toluenesulfonic acid ion,
Perchlorate ion, boron tetrafluoride ion, sulfate ion,
Examples include methyl sulfate ion, ethyl sulfate ion, methane sulfonate ion, trifluoromethane sulfonate ion, and hexafluorophosphate ion.

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

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

[0073]

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[0074]

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[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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[0080]

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[0081]

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[0082]

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[0083]

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[0084]

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[0085]

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[0086]

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The above-mentioned infrared-sensitive dyes are described, for example, by FM Hammer, The Chemistry of
Heterocyclic Compounds No. 18
Volume, The Cyanine Dyes and Re
rated Compounds (A. Weissbe
rger ed. Published by Interscience, Ne
w York 1964). Specifically, Japanese Patent Application No. Hei 11-58
686.

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

High sensitivity and stability can be obtained by using the compound represented by formula (I) in combination.

The supersensitizer of the present invention may be added to the light-sensitive material at any stage during the preparation of the photothermographic material. For example, the supersensitizer may be added to the silver halide after preparing the silver halide emulsion, or may be added to the silver halide emulsion. The mixing can be performed at various stages, such as at the stage when the emulsion is mixed with the organic silver salt dispersion and the silver halide-organic silver salt dispersion is prepared. However,
These supersensitizers are preferably added at the stage before the addition of the photosensitive dye described below, if possible.

In the present invention, the silver halide to be sensitized by infrared sensitization can be prepared by any method known in the field of photographic technology such as a single jet or double jet method in the presence of a protective colloid such as gelatin, for example, by an ammonia method. It can be prepared by any method such as emulsion, neutral method, and acidic method. Thus, it can be prepared in advance and then mixed with other components of the present invention and introduced into the composition used in the present invention. In this case, in order to sufficiently contact the photosensitive silver halide with the organic silver salt, for example, US Pat.
No. 564, No. 3,706,565, No. 3,71
No. 3,833,3,748,143 and British Patent No. 1,362,970. Means using a polymer other than gelatin, such as polyvinyl acetals, and British Patent No. 1,354. Means for Enzymatically Degrading the Gelatin of a Light-Sensitive Silver Halide Emulsion as described in U.S. Pat. No. 4,186,539 or as described in U.S. Pat. No. 4,076,539. By preparing the particles in the presence of a surfactant, various means such as a means for omitting the use of the protective polymer can be applied.

The silver halide functions as an optical sensor and preferably has a small grain size in order to suppress white turbidity after image formation and to obtain good image quality. 0.1 μm or less in average particle size, preferably 0.1 μm or less.
01 μm to 0.1 μm, especially 0.02 μm to 0.08 μ
m is preferred. The shape of the silver halide is not particularly limited, and may be cubic, octahedral, so-called normal crystals, or non-normal crystals, such as spherical, rod-shaped, or tabular grains. The silver halide composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide, and silver iodide.

The photosensitive silver halide used in the photothermographic material of the present invention can also be used in preparing an organic silver salt as described in British Patent 1,447,454. Halogen components such as ions coexist with organic silver salt-forming components, and silver ions are implanted into the components to produce organic silver salts almost simultaneously.

As still another method, a part of the organic silver salt is exposed to light by allowing a silver halide forming component to act on a previously prepared solution or dispersion of the organic silver salt or a sheet material containing the organic silver salt. It can also be converted to neutral silver halide.
The silver halide thus formed is in effective contact with the organic silver salt and exhibits a preferable action. These silver halide-forming components include inorganic halogen compounds, onium halides, halogenated hydrocarbons, N-halogen compounds, and other halogen-containing compounds, and specific examples thereof are described in US Pat. No. 4,009,039. No. 3
457,075, 4,003,749, British Patent No. 1,498,956, and JP-A-53-2.
Nos. 7027 and 53-25420 are described in detail, examples of which are shown below.

[0095] (1) inorganic halide: halide (wherein M represented by e.g. MX _n, H, NH _4, and represents a metal atom, n represents 1 when the M is H and NH _4, M
When is a metal atom, it represents the same value as its valence. Examples of the metal atom include lithium, sodium, potassium, cesium, magnesium, calcium, strontium, barium, zinc, cadmium, mercury, tin, antimony, chromium, manganese, iron, cobalt, nickel, rhodium, and cerium. ). Further, halogen molecules such as bromine water are also effective.

(2) Onium halides: quaternary ammonium halides such as, for example, trimethylphenylammonium bromide and cetylethyldimethylammonium bromide, quaternary phosphonium halides such as tetraethylphosphonium bromide, and trimethylsulfonium Compounds such as tertiary sulfonium halides such as iodide.

(3) Halogenated hydrocarbons: for example, iodoform, bromoform, carbon tetrachloride, 2-bromo-2-methylpropane and the like.

(4) N-halogen compounds: Compounds such as N-chlorosuccinimide, N-bromosuccinimide and N-bromophthalimide.

(5) Other halogen-containing compounds: For example, compounds such as triphenylmethyl chloride, triphenylmethyl bromide and 2-bromoacetic acid.

These silver halide forming components are used in a small amount stoichiometrically with respect to the organic silver salt. Usually, the range is from 0.001 mol to 0.7 mol, preferably from 0.03 mol to 0.5 mol, per 1 mol of the organic silver salt. Two or more silver halide forming components may be used in combination within the above range. The reaction for converting a part of the organic silver salt into silver halide using the above-mentioned silver halide-forming component is also preferably carried out in the presence of a polymer used as a binder described later. In this case, the amount of the polymer used was 1 organic silver salt.
It is 0.01 to 100 parts by weight, preferably 0.1 to 10 parts by weight per part by weight.

The photosensitive silver halide prepared by the various methods described above includes, for example, sulfur-containing compounds, gold compounds,
Platinum compounds, palladium compounds, silver compounds, tin compounds,
Chemical sensitization can be achieved by a chromium compound or a combination thereof. The method and procedure of this chemical sensitization are described in, for example, U.S. Pat. No. 4,036,650, British Patent No. 1,518,850, JP-A-51-224.
No. 30, No. 51-78319, and No. 51-81124. Also, when a part of the organic silver salt is converted to a photosensitive silver halide by a silver halide forming component, as described in US Pat. No. 3,980,482, sensitization is achieved. A low molecular weight amide compound may coexist.

In addition, these photosensitive silver halides may be used in order to prevent illuminance failure and to adjust the gradation.
Metals belonging to group III, such as Rh, Ru, Re, Ir, O
An ion such as s or Fe, a complex thereof, or a complex ion can be contained. It is particularly preferable to add as a complex ion. For example, Ir complex ion such as IrCl ₆ ^2- may be added due to illuminance failure.

The amount of silver halide as these optical sensors is 50 to the total amount of silver halide and an organic silver salt described later.
% Or less, preferably 25% to 0.1%, more preferably 1%
It is between 5% and 0.1%.

In these infrared-sensitive photothermographic materials, an antifoggant is used. These are used to suppress fogging generated during the preparation of silver halide and organic silver salts, and thermal fogging during thermal development.In the present invention, when preparing organic silver salts and preparing silver halide emulsions, Japanese Patent Application Laid-Open No. 4-232 discloses a method for suppressing the process fogging until mixing.
No. 939 is effective. Specific examples thereof are described in the above specification. By using these compounds in the infrared-sensitive photothermographic material of the present invention, a low-fogging and high-sensitivity photosensitive material can be obtained. However, particularly preferred antifoggants include the compounds represented by the above general formulas (A) and (B). By using these compounds, the effect of suppressing fog is high while having high sensitivity.

The substituents of these compounds will be further described.

The compound represented by formula (A) of the present invention will be described in detail.

The halogen atoms represented by Hal ₁ and Hal ₂ may be the same or different and each independently represents a chlorine atom, a bromine atom, an iodine atom or a fluorine atom. Is the case.

Specific examples of the anion group represented by X include a halogen anion (chlorine anion, bromine anion, iodine anion and fluorine anion), a carboxylate anion,
Sulfonate anion, phosphate anion and the like can be mentioned, but a halogen anion is preferable, and a bromine anion is more preferable.

R ₁ represents a group having a carbonyl group as a partial structure, specifically, an acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms). And acetyl, benzoyl, formyl, pivaloyl and the like.), An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 16 carbon atoms, particularly preferably having 2 to 2 carbon atoms).
12, for example, methoxycarbonyl, ethoxycarbonyl and the like. ), An aryloxycarbonyl 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 examples thereof include phenyloxycarbonyl).
Acylamino group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms)
And include, for example, acetylamino, benzoylamino and the like. ), An alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 1 carbon atoms)
6, particularly preferably having 2 to 12 carbon atoms, such as methoxycarbonylamino. ), An aryloxycarbonylamino group (preferably having 7 to 2 carbon atoms)
0, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonylamino. ), A carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms,
Particularly preferably, it has 1 to 12 carbon atoms, and examples thereof include carbamoyl, methylcarbamoyl, diethylcarbamoyl, and phenylcarbamoyl. ), A ureido group (preferably having 1 to 20 carbon atoms, more preferably 1 carbon atom)
To 16, particularly preferably 1 to 12 carbon atoms, for example, ureide, methylureide, phenylureide and the like. ). An acyl group is preferred, and an acetyl group is particularly preferred.

R ₂ and R ₃ represent a hydrogen atom or a substituent which can be substituted on a nitrogen atom. Specific examples of the group that can be substituted for a nitrogen atom include a halogen atom (a chlorine atom, a bromine atom, an iodine atom, a fluorine atom, and preferably a bromine atom), an alkyl group (preferably having 1 to 20 carbon atoms, More preferably, it has 1 to 12 carbon atoms, and particularly preferably 1 to 12 carbon atoms.
8, for example, methyl, trifluoromethyl, ethyl, iso-propyl, 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 having 2 to 12 carbon atoms, and particularly preferably having 2 carbon atoms.
-8, for example, vinyl, allyl, 2-butenyl, 3
-Pentenyl and the like. ), Alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, for example, propargyl,
Pentenyl and the like. ), An aryl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 20 carbon atoms,
Particularly preferably, it has 2 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 10 carbon atoms, and particularly preferably 0 to 6 carbon atoms).
And examples thereof include amino, methylamino, dimethylamino, diethylamino, dibenzylamino and the like. ), An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 1 carbon atoms).
2, for example, acetyl, benzoyl, formyl, pivaloyl and the like. ), 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, for example, methoxycarbonyl, ethoxycarbonyl and the like.), Aryloxycarbonyl A 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, phenyloxycarbonyl and the like), an acylamino group (preferably having 2 to 2 carbon atoms). 20, more preferably 2 carbon atoms
-16, particularly preferably 2-10 carbon atoms, such as acetylamino and benzoylamino. ), 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, for example, methoxycarbonylamino and the like), an aryloxycarbonyl group (Preferably 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as phenyloxycarbonyl, etc.), a sulfonylamino group (preferably 1 to carbon atoms). 2
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 having 0 to 16 carbon atoms, and particularly preferably having 0 to 12 carbon atoms.
And include, for example, sulfamoyl, methylsulfamoyl, dimethylsulfamoyl and the like. ), 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 alkylsulfonyl group (preferably having 1 carbon atom)
20 to 20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, such as methylsulfonyl and ethylsulfonyl. ), An arylsulfonyl 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, phenylsulfonyl and the like can be mentioned. ), 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 and including methanesulfinyl and benzenesulfinyl), and a ureido group (preferably 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 ureide, methylureide, and phenylureide. ), A silyl group (for example, trimethylsilyl group), a nitro group, a hydroxy group, a phosphate group, and a heterocyclic group (for example, triazolyl, imidazolyl, pyridyl, furyl, piperidyl, morpholinyl and the like). These groups may be further substituted. n is 1 or 2
And more preferably 2.

Next, the compound represented by formula (B) will be described in detail. The halogen atoms represented by Hal ₃ and Hal ₄ may be the same or different and each independently represents a chlorine atom, a bromine atom, an iodine atom, or a fluorine atom, but preferably both are bromine atoms It is.

Z represents an atomic group necessary for constructing a 5- to 7-membered nitrogen-containing heterocycle together with an adjacent nitrogen atom. The nitrogen-containing heterocycle formed is preferably an aromatic nitrogen-containing heterocycle. There are specifically, pyrrole, imidazole, pyrazole, pyridine, pyrazine, pyridazine,
Pyrimidine, triazole, triazine, tetrazine,
Pentazine, indole, indazole, purine, thiadiazole, oxadiazole, quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzothiazole And the like. Preferably,
Pyridine, pyrazine, pyrimidine, pyridazine, triazine, quinoline, isoquinoline, naphthyridine, quinoxaline, quinazoline, cinnoline, and pteridine.
More preferred are pyridine, quinoline and isoquinoline.

Specific examples of the compounds represented by formulas (A) and (B) are shown below, but it should not be construed that the invention is limited thereto.

[0114]

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[0115]

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[0116]

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[0117]

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[0118]

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[0119]

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[0120]

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Many of the above compounds are known.
It can be purchased directly from reagent manufacturers such as Tokyo Chemical Industry. Further, it can be easily synthesized and produced according to the following literature. Representative document names are listed below. 78, 1400, 1957, Angew. Ch
em. 71, 126, 1959; Amer. Ch
em. Soc. 79, 4622, 1957; Ch
em. Soc. 2783, 1931, Bull. Ch
em. Soc. Jpn. 31, 347, 1958
J. Amer. Chem. Soc. 91: 1679
969; Org. Chem. 37, 2172, 1
972; Chem. Soc. 77, 799, 19
In 2000, Angew. Chem. Vol. 36, No. 2, 2342
Page 1997, Bull. Chem. Soc. Jpn.
60, 4187, 1997, Org. Synth. C
all. Vol. IV 489, 1963; Org.
Chem. 28, 1100, 1963, Chem. H
eterocycl. Compd. Volume 5, page 844, 196
9 years, J. Chem. Soc. Perkin Tran
s. 1, 909, 1978; Org. Chem.
34, 3434, 1969, Chem. Ber. 36
Vol. 987, 1981, Bull. Chem. Soc.
Jpn. 64, No. 3, p. 796, 1991, Bull. C
hem. Soc. Jpn. 60 No. 7, page 2667 p. 198
7 years, J. Amer. Chem. Soc. 19 562
Page 1897.

The amount of the compounds represented by formulas (A) and (B) of the present invention is not particularly limited, but may be from 10 ^-6 mol to ^10-6 mol.
1 mol / Ag mol is preferred, and especially 10 ^-4 mol to 10 ^-2.
Mol / Ag mol is preferred.

The compounds represented by the general formulas (A) and (B) of the present invention can be added to either a photosensitive layer or a non-photosensitive layer, but preferably a photosensitive layer. The compounds represented by formulas (A) and (B) of the present invention are preferably added after being dissolved in an organic solvent.

The non-photosensitive organic silver salt represented by a) of the invention will be described. These organic silver salts have a role of supplying silver in the dissolution physical development centering on a latent image formed on silver halide as an optical sensor.

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

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

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

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

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

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

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

The reducing agent c) of the present invention capable of reducing silver ions of the organic silver salt when activated by heat is a reducing agent for physical dissolution development during thermal development. Various reducing agents.

Phenols, polyphenols having two or more phenol groups, naphthols, bisnaphthols, polyhydroxybenzenes having two or more hydroxyl groups, polyhydroxynaphthalenes having two or more hydroxyl groups, ascorbic acids , 3-pyrazolidones, pyrazolin-5-ones, pyrazolines, phenylenediamines, hydroxylamines, hydroquinone monoethers, hydroxamic acids, hydrazides, amide oximes, N-hydroxyureas, and the like. More specifically, for example, U.S. Pat. Nos. 3,615,533, 3,679,426, 3,672,904, 3,751,252, and 3,782,949. ,
Nos. 3,801,321 and 3,794,488
No. 3,893,863, No. 3,887,37
No. 6, No. 3,770,448, No. 3,819,3
No. 82, No. 3,773, 512, No. 3, 839,
No. 048, No. 3,887,378, No. 4,00
No. 9,039, No. 4,021,240, British Patent No. 1,486,148 or Belgian Patent No. 786.
No. 086 and JP-A-50-36143, 5
No. 0-36110, No. 50-116023, No. 50-
No. 99719, No. 50-140113, No. 51-51
No. 933, No. 51-23721, No. 52-84727
And Japanese Patent Publication No. 51-35851 include the reducing agents specifically exemplified, and the present invention can be appropriately selected from such known reducing agents and used. As a selection method, the simplest method is to actually prepare a photothermographic material and evaluate the photographic performance to determine the superiority of the reducing agent used.

Among the above reducing agents, when an aliphatic silver carboxylate is used as the organic silver salt, preferred reducing agents include polyphenols in which two or more phenol groups are linked by an alkylene group or sulfur. In particular, an alkyl group (eg, methyl group, ethyl group, propyl group, t-butyl group, cyclohexyl group, etc.) or an acyl group (eg, acetyl group, propionyl group, etc.) is provided at at least one of the positions adjacent to the hydroxy substitution position of the phenol group. Are polyphenols in which two or more of the phenol groups substituted by an alkylene group or sulfur, for example, 1,1-bis (2
-Hydroxy-3,5-dimethylphenyl) -3,5
5-trimethylhexane, 1,1-bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane,
1,1-bis (2-hydroxy-3,5-di-t-butylphenyl) methane, 2-hydroxy-3-t-butyl-5-methylphenyl)-(2-hydroxy-5-methylphenyl) methane 6,6'-benzylidene-bis (2,4-di-t-butylphenol), 6,6'-benzylidene-bis (2-t-butyl-4-methylphenol), 6,6'-benzylidene-bis (2,4-dimethylphenol), 1,1-bis (2-hydroxy-
3,5-dimethylphenyl) -2-methylpropane,
1,1,5,5-tetrakis (2-hydroxy-3,5
-Dimethylphenyl) -2,4-ethylpentane, 2,
2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5
U.S. Pat. Nos. 3,589,903 and 4,021,249 or British Patent 1,486,148 and JP-A-51-51933. No. 50-36110, No. 50
Polyphenol compounds described in JP-A-116023, JP-A-52-84727 or JP-B-51-35727), and bisnaphthols described in U.S. Pat. No. 3,672,904, for example, 2,2 '-Dihydroxy-1,1'-binaphthyl,6,6'-dibromo-
2,2'-dihydroxy-1,1'-binaphthyl, 6,
6'-dinitro-2,2'-dihydroxy-1,1'-
Binaphthyl, bis (2-hydroxy-1-naphthyl) methane, 4,4'-dimethoxy-1,1'-dihydroxy-2,2'-binaphthyl and the like, furthermore U.S. Pat. No. 3,80
1,321, sulfonamidophenols or sulfonamidonaphthols, for example, 4-benzenesulfonamidophenol, 2-benzenesulfonamidophenol, 2,6-dichloro-4
-Benzenesulfonamidophenol, 4-benzenesulfonamidonaphthol and the like.

The amount of the reducing agent used in the photothermographic material of the present invention varies depending on the type of the organic silver salt, the reducing agent, and other additives. 05 mol to 10 mol, preferably 0.1 mol to 3 mol
Molar is appropriate. Further, within this range, two or more of the above-mentioned reducing agents may be used in combination. In the present invention, it may be preferable to add and mix the reducing agent to the photosensitive solution immediately before coating and apply the reduced solution because the photographic performance fluctuation due to the stagnation time of the photosensitive solution is small.

The photothermographic material of the present invention, which forms a photographic image by heat development, comprises a reducible silver source (organic silver salt), a photosensitive silver halide, a reducing agent and, if necessary, silver. It is preferable that the photothermographic material contains a color toning agent which suppresses the color tone of the present invention in a state of being usually dispersed in an (organic) binder matrix. The photothermographic material of the present invention is stable at room temperature, but is exposed to a high temperature (for example, 80 ° C to 14 ° C).
(0 ° C.). Heating generates silver through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This oxidation-reduction reaction is accelerated by the catalytic action of the latent image generated on the silver halide upon exposure. The silver formed by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image. This reaction process proceeds without supplying a processing liquid such as water from the outside.

Examples of suitable toning agents used in the present invention are R.
D17029 discloses the following.

Cyclic imides, pyrazolin-5-ones,
And quinazolinones (for example, succinimide, phthalimide, 3-phenyl-2-pyrazolin-5-one, 1-
Phenylurazole, quinazoline and 2,4-thiazolidinedione); naphthalimides (eg, N-hydroxy-1,8-naphthalimide); mercaptans (eg, 3-mercapto-1,2,4-triazole); (Aminomethyl) aryldicarboximides (eg, N- (dimethylaminomethyl) phthalimide); blocked pyrazoles (eg, N,
N'-hexamethylenebis (1-carbamoyl-3,5
-Dimethylpyrazole)); isothiuronium (iso
combinations of thiuronium derivatives and certain photobleaches, such as combinations of 1,8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzothiazole ); Phthalazinone, phthalazinone derivatives or metal salts of these derivatives (e.g., 4- (1
-Naphthyl) phthalazinone, 6-chlorophthalazinone,
5,7-dimethyloxyphthalazinone and 2,3-dihydro-1,4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, 6-chlorophthalazinone and sodium benzenesulfinate or 8
-Methylphthalazinone and sodium p-trisulfonate); a combination of phthalazine and phthalic acid; phthalazine (including adducts of phthalazine) and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-
At least one selected from phenylene acid derivatives and anhydrides thereof (for example, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride)
Quinazolinediones, benzoxazines, naphthoxazine derivatives; benzoxazine-2,4-diones (eg, 1,3-benzoxazine-2,4-dione); pyrimidines and asymmetric triazines ( For example, 2,4-dihydroxypyrimidine),
And tetraazapentalene derivatives (for example, 3,6-dimercapto-1,4-diphenyl-1H, 4H-2,3
a, 5,6a-Tetraazapentalene). Preferred toning agents are phthalazinone or phthalazine.

The photothermographic material of the present invention may contain an antifoggant which suppresses fog during heat development. Preferred antifoggants are compounds as disclosed in U.S. Patent No. 3,874,946 and ibid. No. _{4,756,999, -C (X 1) (} X 2) (X 3) ( where X ₁ and X ₂
Is a heterocyclic compound having one or more substituents represented by halogen and X ₃ is hydrogen or halogen). As examples of suitable antifoggants, compounds described in paragraph numbers [0030] to [0036] of JP-A-9-288328 are preferably used.

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

The binder suitable for the photothermographic material of the present invention is transparent or translucent and generally colorless, and includes natural polymers, synthetic polymers and copolymers, and other film-forming media such as gelatin, gum arabic and polyvinyl alcohol. , Hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, polyvinylpyrrolidone, casein, starch, polyacrylic acid, polymethyl methacrylate, polymethacrylic acid, polyvinyl chloride, copoly (styrene-maleic anhydride),
Copoly (styrene-acrylonitrile), copoly (styrene-butadiene), polyvinylacetals such as polyvinylformal, polyvinylbutyral, polyesters, polyurethanes, phenoxy resins, polyvinylidene chloride, polyepoxides, polycarbonates, polyvinyl acetates, cellulose Esters,
There are polyamides and the like, which may be water-soluble or water-insoluble. However, among these binders, particularly preferred are water-insoluble polymers such as cellulose acetate, cellulose acetate butyrate and polyvinyl butyral. Among these, particularly preferred polymers used in the photothermographic layer include polyvinyl formals Among them, polyvinyl butyral is particularly preferred, and cellulose acetate and cellulose acetate butyrate are particularly preferred polymers as the backcoat layer for the protective layer.

In the present invention, the binder amount of the photosensitive layer is preferably from 1.5 to 6 g / m ² . More preferably, it is 1.7 to 5 g / m ² . If it is less than 1.5 g / m ² , the density of the unexposed portion will increase significantly and may not be usable.

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

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

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

The photothermographic material of the present invention is particularly preferably 600 to 8
In the case of a photothermographic material for output of an image setter having an oscillation wavelength of 00 nm, a hydrazine compound is preferably contained in the light-sensitive material. Preferred hydrazine compounds used in the present invention include RD23515 (19
November 1983, p. 346) and references cited therein, as well as U.S. Pat. Nos. 4,080,207 and 4,2
No. 69,929, No. 4,276,364, No. 4,
Nos. 278,748, 4,385,108, 4,459,347, 4,478,928, 4,560,638, 4,686,167,
Nos. 4,912,016 and 4,988,604
No. 4,994,365 and 5,041,35
No. 5,104,769, British Patent No. 2,01
No. 1,391B, European Patent Nos. 217,310 and 3
Nos. 01,799 and 356,898,
No.179734, No.61-170733, No.61-2
Nos. 70744, 62-178246, 62-27
No. 0948, No. 63-29751, No. 63-3253
No. 8, 63-104047, 63-121838
No. 63-129337, No. 63-223744
Nos. 63-234244 and 63-234245
No., 63-234246, 63-294552
No. 63-306438, No. 64-10233,
JP-A-1-90439, JP-A-1-100530, JP-A-1
No. -105941, No. 1-105943, No. 1-27
Nos. 6128, 1-280747, 1-228354
8, No. 1-283549, No. 1-285940,
2-2541, 2-77057, 2-139
No. 538, No. 2-196234, No. 2-196235
No. 2-198440, No. 2-198441, No. 2-198442, No. 2-220042, No. 2-2
No. 21953, No. 2-221954, No. 2-2853
No. 42, No. 2-285343, No. 2-289843
Nos. 2-302750, 2-304550, 3-37642, 3-54549 and 3-125
No. 134, No. 3-184039, No. 3-240036
No. 3-240037, No. 3-259240, No. 3-280038, No. 3-282536, No. 4-5
No. 1143, No. 4-56842, No. 4-84134
No. 2-230233, No. 4-96053, No. 4
-216544, 5-45761, 5-457
No. 62, No. 5-45763, No. 5-45764, No. 5-45765, No. 6-289524, No. 9-16
No. 0164 and the like.

In addition to the above compounds, compounds represented by (Chemical Formula 1) described in JP-B-6-77138 are specifically described.
Page 4 and the compound represented by the general formula (1) described in JP-B-6-93082. Compound,
General formula (4) described in JP-A-6-23049,
Compounds represented by (5) and (6), specifically, compounds 4-1 to 4-10, 2
Compounds 5-1 to 5-42 on pages 8 to 36, and 3
Compounds 6-1 to 6-7 described on pages 9 and 40;
General formulas (1) and (2) described in -289520
Specifically, compounds 1-1) to 1-17) and 2-1) described on pages 5 to 7 of the same publication and (Chemical Formula 2) described in JP-A-6-313936. Specific examples of the compounds represented by formulas (1) and (3) include compounds described on pages 6 to 19 of the same publication, and compounds represented by (1) described in JP-A-6-313951. Specifically, compounds described on pages 3 to 5 of the same publication, compounds represented by the general formula (I) described in JP-A-7-5610, and specifically, pages 5 to 10 of the same publication Compounds I-1 to I-3 described in
8. General formula (II) described in JP-A-7-77783
And specifically, compounds II-1 to II-102 described in pages 10 to 27 of the same publication, and JP-A-7-104.
General formula (H) and general formula (Ha) described in JP-A-426
Specific examples thereof include those described in Compounds H-1 to H-44 on pages 8 to 15 of the same publication.

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

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

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

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

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

The photothermographic material of the present invention is stable at normal temperature, but is developed by heating to high temperature after exposure. The heating temperature is preferably from 80 ° C. to 200 ° C., and more preferably from 100 ° C. to 150 ° C. If the heating temperature is lower than 80 ° C., a sufficient image density cannot be obtained in a short time, and if the heating temperature is higher than 200 ° C., the binder is melted and adversely affects not only the image itself but also transportability such as transfer to a roller and a developing machine. Effect. By heating, a silver image is generated by a redox reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This reaction process proceeds without any supply of a processing liquid such as water from the outside.

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

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

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

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

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

[0159] In order to form the vertical multiple, a method such as combining, using return light, or superimposing a high frequency is preferable.
In addition, the vertical multi means that the exposure wavelength is not single, and the distribution of the exposure wavelength is usually 5 nm or more, preferably 10 nm or more.
nm or more. The upper limit of the exposure wavelength distribution is not particularly limited, but is usually about 60 nm.

Further, in the present invention, the fact that the photosensitive material contains 5 to 1000 mg / m ² at the time of thermal development provides high sensitivity and low fog (discrimination between exposed and unexposed areas). (Nation is excellent).

The content of the solvent in these photosensitive materials can be adjusted by changing conditions such as temperature conditions in a drying step after the coating step. The content of the solvent can be measured by gas chromatography under conditions suitable for detecting the contained solvent.

For example, it can be measured by the following method.

The area of the photothermographic material is 46.3 cm.
^Two pieces are cut out, finely chopped to about 5 mm, stored in a special vial, sealed with a septum and an aluminum cap, and set in a Hewlett-Packard HP7694 headspace sampler. The gas chromatography (GC) connected to the headspace sampler is a Hewlett-Packard type 5971 equipped with a flame ionization detector (FID) as a detector. As a measurement condition, a heating condition of a head space sampler: 1
20 ° C, 20 minutes, GC introduction temperature: 150 ° C, Column: J
& W company DB-624, temperature rise: 45 ° C for 3 minutes → 100 ° C
(8 ° C./min) to obtain a gas chromatogram. The solvent to be measured was MEK, methanol, and toluene. After storing a certain amount of each diluted with butanol in the solvent on the left in a dedicated vial, the peak area of the chromatogram obtained by measuring in the same manner as above was used. The prepared calibration curve is used to obtain the solvent content in the film.

The amount of the solvent contained in the light-sensitive material according to the present invention is from 5 to 1000 mg / m 2 in total (weight basis).
² , preferably 40 to 500 mg / m ² .

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

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

[0167]

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

Example 1 <Preparation of PET-subtracted photographic support> Concentration: 0.170
A corona discharge treatment of 8 w / m ² · min was applied to both surfaces of a commercially available biaxially stretched and heat-fixed 175 μm-thick PET film colored blue (measured with a densitometer PDA-65 manufactured by Konica Corporation). .

(Preparation of Photosensitive Silver Halide Emulsion 1) Water 9
6. Ossein gelatin having an average molecular weight of 100,000 in 00 ml
5 g and 10 mg of potassium bromide were dissolved at a temperature of 35 ° C.
After adjusting the pH to 3.0, 370 ml of an aqueous solution containing 74 g of silver nitrate, potassium bromide and potassium iodide in a molar ratio of (98/2) were equimolar to silver nitrate, and iridium chloride was converted to silver 1
370 ml of an aqueous solution containing 1 × 10 ^-4 mol per mol was added to p
Ag was added over 10 minutes by a controlled double jet method while keeping the Ag at 7.7. Then 4-hydroxy-
6-methyl-1,3,3a, 7-tetrazaindene
After adding 3 g and adjusting the pH to 5 with NaOH, the average particle size was 0.06 μm, the variation coefficient of the particle size was 12%, and [1
00] Cubic silver iodobromide grains having an area ratio of 87% were obtained. This emulsion was subjected to coagulation sedimentation using a gelatin coagulant and desalting treatment, and then 0.1 g of phenoxyethanol was added thereto.
9, and adjusted to a pAg of 7.5 to obtain a photosensitive silver halide emulsion 1.

(Preparation of Powdered Organic Silver Salt A) 111.4 g of behenic acid and 83.8 of arachidic acid were added to 4720 ml of pure water.
g and 54.9 g of stearic acid were dissolved at 80 ° C. Next, while stirring at a high speed, 540.2 ml of a 1.5 M aqueous sodium hydroxide solution was added, and 6.9 ml of concentrated nitric acid was added.
Upon cooling to 55 ° C., a sodium organic acid solution was obtained. While maintaining the temperature of the above-mentioned organic acid sodium solution at 55 ° C., the above-mentioned silver halide emulsion 1 (containing 0.038 mol of silver) and 450 ml of pure water were added, and the mixture was stirred for 5 minutes. Next, 760.6 ml of a 1 M silver nitrate solution was added over 2 minutes, followed by 2 more minutes.
The mixture was stirred for 0 minutes, and the water-soluble salts were removed by filtration. Thereafter, washing with deionized water and filtration are repeated until the conductivity of the filtrate becomes 2 μS / cm, and centrifugal dehydration is performed.
Drying with warm air was performed at 37 ° C. until the weight was not lost, to obtain a powdered organic silver salt A.

(Preparation of photosensitive emulsion dispersion) Polyvinyl butyral powder (Butvar B manufactured by Monsanto)
-79) 14.57 g of methyl ethyl ketone 1457 g
And, while stirring with a dissolver-type homogenizer, 500 g of powdered organic silver salt A was gradually added and mixed well. Thereafter, dispersion was carried out at a peripheral speed of 13 m and a residence time in the mill for 0.5 minute with a media type dispersing machine (manufactured by gettzmann) filled with 80% of 1 mm Zr beads (manufactured by Toray) to prepare a photosensitive emulsion dispersion.

(Preparation of Photosensitive Layer Coating Solution) The photosensitive emulsion dispersion (500 g) and 100 g were kept at 21 ° C. while stirring. Immediate antifogging agent 1-1 (0.21 g) was added, and the mixture was stirred for 1 hour. Further, a methanol solution (3.25 ml) of calcium bromide (10%) was added, and the mixture was stirred for 30 minutes.

Next, a mixed solution of a sensitizing dye, 2-chlorobenzoic acid and a supersensitizer (mixing molar ratio 1:25:20,
(A 0.1% methanol solution of a sensitizing dye, 7 ml) was added thereto, and the mixture was stirred for 1 hour.
Stir for 0 minutes. Here, each supersensitizer is added in an equimolar amount.

While keeping the temperature at 13 ° C., 48 g of polyvinyl butyral is added and sufficiently dissolved, and then the following additives are added.

Stabilizer 1 0.20 g Developer (1,1-bis (2-hydroxy-3,5-dimethylphenyl) -2-methylpropane) 15 g Desmodu N3300 (Mobay, aliphatic isocyanate) 1.10 g Print Out-out inhibitor 1.55 g Phthalazine 1.5 g Tetrachlorophthalic acid 0.5 g 4-Methylphthalic acid 0.5 g In the above-mentioned preparation method, a comparative compound and a compound of the general formula (I) were used as the infrared sensitizing dye and the supersensitizer. The compounds were changed as shown in Table 1 to prepare coating solutions for the photosensitive layer, and the coating was carried out by the following method while keeping the temperature at 13 ° C. In addition, the comparative compound C-1 of the supersensitizer is 2-mercaptobenzimidazole.

[0176]

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[0177]

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(Preparation of Coating Solution for Surface Protective Layer) Cellulose acetate butyrate (Eastman Chemical)
7.5 g of CAB171-15) was dissolved in 42.5 g of methyl ethyl ketone, and calcium carbonate (Specialty Minerals, Sup.) was dissolved therein.
er-Pflex 200), and dispersed by a dissolver-type homogenizer at 8000 rpm for 30 minutes to prepare a calcium carbonate dispersion.

While stirring with 865 g of methyl ethyl ketone, cellulose acetate butyrate (Eastman) was added.
Chemical Company, CAB171-15) 96 g,
4.5 g of polymethyl methacrylic acid (Rohm & Haas, Paraloid A-21) was added. 1.5 g of a vinyl sulfone compound HD-1, 1.0 g of benzotriazole, and an F-based activator (Surflon KH-4 manufactured by Asahi Glass Co., Ltd.)
0) 1.0 g was added and dissolved. Finally, 30 g of a calcium carbonate dispersion was added and stirred to prepare a surface protective layer solution.

(Preparation of Back Surface Coating Solution) Cellulose acetate butyrate (Eastman Chemical Company, CA) was stirred with 830 g of methyl ethyl ketone.
B381-20) 84.2 g, polyester resin (Bo)
4.5 g of stic (Vitel PE2200B) was added and dissolved. 10.30 g of an infrared dye was added to the dissolved solution, and 4.5 g of an F-based activator (Surflon KH40 manufactured by Asahi Glass Co., Ltd.) and 4 g of an F-based activator dissolved in 43.2 g of methanol and Megafag F120K (Dainippon Ink Co., Ltd.) )
2.3 g was added and thoroughly stirred until dissolved. Finally, silica (W.P.) dispersed in methyl ethyl ketone at a concentration of 1 wt% with a dissolver type homogenizer.
R. 75g of Grace, Syloid 64X6000)
The mixture was added and stirred to prepare a coating solution for the back surface.

(Coating) The coating solution for the back surface thus prepared was extruded and dried by a coater so that the dry film thickness became 3.5 μm. Drying was performed for 5 minutes using a drying air having a drying temperature of 100 ° C. and a dew point of 10 ° C.

Next, the above-mentioned photosensitive layer coating solution and surface protective layer coating solution were simultaneously layer-coated using an extrusion coater. The photosensitive layer has a coated silver amount of 2.4 g / m ² , and the surface protective layer has a dry film thickness of 20 μm per minute so as to be 2.5 μm.
Was applied at the following speed. Thereafter, drying was performed for 10 minutes using a drying air having a drying temperature of 75 ° C. and a dew point temperature of 10 ° C.

The photosensitive material No. was prepared by using each of the photosensitive layer coating solutions in which the infrared sensitizing dye and the supersensitizer were changed as shown in Table 1. Nos. 1-26 were produced.

(Evaluation of Storage Property of Film) Two test pieces were taken from each of the obtained photosensitive materials, and one of them was exposed immediately after coating under the following conditions.
After development, the sensitivity and the density of the fogged portion were measured. The sensitivity is the same as that of Sample No. Relative sensitivity (S) with the sensitivity of 9 as 100,
The fog density is shown as fog in Table 1 and its absolute value is shown in Table 1.

The other sheet was stored under light shielding at 25 ° C. and 55% RH for 3 days, exposed and developed in the same manner, and the sensitivity and fog were measured. The increase in sensitivity and fog were calculated by the following methods. Are shown in Table 2.

Increase of sensitivity (ΔS) = sensitivity of development after light-shielded storage—sensitivity of immediate development Increase of fog (Δfog) = fog of development after light-shielded storage—
Immediate development fog (exposure and thermal development), that is, exposure by laser scanning exposure from an emulsion side of the photosensitive material using an exposure machine that uses a semiconductor laser that has been subjected to high-frequency superimposition and has a vertical multi-mode semiconductor laser having a wavelength of 800 nm to 820 nm as an exposure source. Gave. At this time, an image was formed at an angle of 75 ° C. between the exposure surface of the photosensitive material and the exposure laser beam. (Note that an image with less unevenness and unexpectedly good sharpness was obtained compared to the case where the angle was set to 90 ° C.) Thereafter, protection of the photosensitive material was performed using an automatic developing machine having a heat drum. 11 so that the layer and the drum surface are in contact with each other.
The film was thermally developed at 0 ° C. for 15 seconds. At that time, exposure and development were performed in a room conditioned at 23 ° C. and 50% RH.

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[Table 1]

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[Table 2]

Table 1 shows that the sample to which the mercapto compound of the present invention was added exhibited higher sensitivity and a lower fog level than the comparative samples without the mercapto compound (photosensitive materials No. 8, No. 16, No. 24). The photosensitive material No. 1 using the comparative supersensitizer was used. 25, no. 26 shows a sensitizing effect similar to that of No. 26.

Further, as compared with the sample to which a comparative mercapto compound (2-mercaptobenzimidazole) having a heterocyclic ring known from Table 2 as a supersensitizer was added, the sample of the present invention had equal or better photographic performance. As for the change with time during storage of the film, the sample of the present invention has a significantly smaller desensitization width than the comparative example using the comparative compound C-1, indicating that the sample is excellent.

According to the present invention, it is possible to achieve both a reduction in fog over time and a reduction in sensitivity during storage of a film.

[0192]

According to the present invention, the sensitivity of a photothermographic material sensitive to an infrared laser is improved, and the stability of the photothermographic material when stored over time is improved.
A photosensitive material suitable for medical or printing applications was obtained.

Claims (6)

[Claims] 1. A non-photosensitive organic silver salt on a support, b) silver halide spectrally sensitized by an infrared sensitizing dye, c) the organic silver salt when activated by heat A photothermographic material comprising a reducing agent capable of reducing silver ions and d) a binder, further comprising a compound represented by the following general formula (I). General formula (I) R-SM [wherein, R represents an acyclic aliphatic group, a heteroalicyclic group, or an aromatic group. M represents hydrogen, an alkali metal, or a quaternary ammonium group. ] 2. The method according to claim 1, wherein the silver halide is represented by the following general formula (1):
2. The photothermographic material according to claim 1, wherein the photothermographic material is spectrally sensitized by at least one sensitizing dye selected from (4). Embedded image [In the general formulas (1) to (4), Y ₁ , Y ₂ , Y ₁₁ ,
Y ₂₁ , Y ₂₂ and Y ₃₁ each represent an oxygen atom, a sulfur atom, a selenium atom, a —C (R _a ) (R _b ) — group, or —CH ＝ CH
And Z ₁ represents a group of nonmetallic atoms necessary to complete a 5- or 6-membered fused ring. R is a hydrogen atom, a lower alkyl group, a cycloalkyl group, an aralkyl group, a lower alkoxy group, an aryl group, hydroxy group, a halogen atom, R _a and R _b are each a hydrogen atom, a lower alkyl group or R _a and R represents a group of nonmetallic atoms necessary for forming a 5- or 6-membered aliphatic spiro ring by bonding between _b . R ₁ , R
₁₁ , R ₂₁ , R ₂₂ , R ₃₁ and R ₃₂ are each an aliphatic group,
Or R ₁ and W _3, R ₁₁ represents a nonmetallic atomic group necessary to form a condensed ring with the W _14. R _c and R _d each represent a lower alkyl group, a cycloalkyl group, an aralkyl group, an aryl group, or a heterocyclic group. W ₁ , W ₂ , W ₃ , W ₄ ,
_{W 11, W 12, W 13} , W 14, W 21, W 22, W 23, W 24, W
₃₁ , W ₃₂ , W ₃₃ and W ₃₄ are each a hydrogen atom, a substituent or W ₁ is W ₂ , W ₁₁ is W ₁₂ , W ₂₁ is W ₂₂ , W ₂₃ is W ₂₄ and W ₃₁ the W _32, W ₃₃ represents a nonmetallic atomic group necessary to form a fused ring bond between W _34. V ₁ ~
V ₉ , V _{11 to} V ₁₃ , V _{21 to} V ₂₉ , and V _{31 to} V ₃₃ each represent a hydrogen atom, a halogen atom, an amino group, an alkylthio group, an arylthio group, a lower alkyl group, a lower alkoxy group, an aryl group, and an aryl Represents an oxy group, a heterocyclic group, or V ₁ is V ₃ , V ₂ is V ₄ , V ₃ is V ₅ , V ₄ is V ₆ ,
₅ and V _7, V ₆ and V _8, V ₇ and V _9, V ₁₁ and V _13, V
₂₁ and V _23, V ₂₂ and V _24, V ₂₃ and V _25, V ₂₄ is V ₂₆
When, and V ₂₅ is V _27, and V ₂₆ are V _28, V ₂₇ and V _29, V ₃₁
Represents a non-metallic atomic group necessary for forming a 5- to 7-membered coupled between V _33, any one and V of V ₁ ~V _9
11 any one of ~V ₁₃ is a group other than a hydrogen atom.
X ₁ , X ₁₁ , X ₂₁ and X ₃₁ each represent an ion necessary for canceling the intramolecular charge, and 11, 11, 111 and 121 represent the ions necessary for canceling the intramolecular charge, respectively. Represents a number. k1, k2, k21 and k22 are each 0
Or represents 1. n21, n22, n31 and n32 each represent an integer of 0 to 2, and n21, n22 and n31
And n32 do not become 0 at the same time. p1 and p11
Is each 0 or 1, q1 and q11 are each an integer of 1 and 2, and the sum of p1 and q1 and the sum of p11 and q11 does not exceed 2. ] 3. The photothermographic material according to claim 1, comprising a compound represented by the following general formula (A) or (B). Embedded image [In the formula, Hal ₁ and Hal ₂ represent a halogen atom. H
al ₁ and Hal ₂ may be the same or different. X represents an anionic group. R ₁ represents a group having a carbonyl group as a partial structure, and R ₂ and R ₃ represent a substituent which can be substituted on a nitrogen atom or a hydrogen atom. R _{1 to} R ₃ do not bond to each other so as to form a ring structure in which the nitrogen atom becomes an inner ring atom. n represents 1 or 2. [Chemical formula 3] [In the formula, Hal ₃ and Hal ₄ represent a halogen atom. H
al ₃ and Hal ₄ may be the same or different. Z represents an atomic group necessary for constructing a 5- to 7-membered nitrogen-containing heterocycle together with an adjacent nitrogen atom. This nitrogen-containing hetero ring may be condensed with another ring, or may be bonded by a bonding group. ] 4. A laser scanning exposure apparatus wherein an angle between an exposure surface of the photothermographic material and a scanning laser beam does not become substantially perpendicular to the photothermographic material according to claim 1, 2 or 3. An image exposure method, wherein exposure is performed by: 5. An image exposure method, wherein the photothermographic material according to claim 1, 2 or 3, is exposed by a laser scanning exposure machine in which a scanning laser beam is a vertical multi-scan. 6. An image forming method, wherein the photothermographic material according to claim 1, 2, or 3 is heat-developed in a state containing 5 to 1000 mg / m ^{2 of a} solvent.