JP2000206642A - Photosensitive heat-developable image forming material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the photosensitive heat-developable material high in activity and superior in preservation by adding one kind of specific compound of heteroaromatic mercapto compound and heteroaromatic disulfide compound, and a specific compound to the same plane of a supporter. SOLUTION: The photosensitive heat-developable material contains photosensitive silver halide, a reducible silver salt, a reducing agent, and a binder, and one of heteroaromatic mercapto or disulfide compounds in an amount of 10-3-1 mol per 1 mol of silver halide, and further, the salicylic acid derivative represented by the formula in which M is an H atom or a k-valent cation; R is a substituent; (n) is 1, 2, 3, or 4, and when n>=2, each of plural R may be same or different; and (k) is an integer of >=1 and when M is an H atom, k=1. When the mercapto compound or disulfide compound is contained in an amount of <10-3 or >1 mol per 1 mol of silver halide, Dmax and sensitively deteriorate and satisfactory photographic characteristics can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive heat-developable image forming material, that is, a heat-developable photothermographic material. The present invention relates to a photothermographic material which is used for photoengraving and medical use.

[0002]

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

In recent years, in the field of photoengraving, it has been strongly desired to reduce the amount of processing waste liquid from the viewpoint of environmental protection and space saving.
Therefore, there is a need for a technology relating to a photothermographic material for photoengraving, which can be efficiently exposed by a laser scanner or a laser imagesetter and can form a clear black image having high resolution and sharpness. It has been. In these photosensitive heat developing materials,
By eliminating the use of solution processing chemicals, it is possible to provide customers with a simpler and more environmentally friendly thermal development processing system.

[0004] Methods of forming an image by thermal development are described in, for example, US Patent Nos. 3,152,904 and 3,457,075, and US Pat.
Morgan and B.A. "Thermal Proces Silver System (Thermally Proces)" by Shely
sed Silver Systems) A "(Imaging Processes and M
aterials) Neblette 8th edition, Sturge, V.E.
Walworth, A .; Shepp
Edited, page 2, 1969). Such photosensitive materials are prepared by dispersing a reducible non-photosensitive silver source (eg, an organic silver salt), a catalytically active amount of a photocatalyst (eg, silver halide), and a silver reducing agent, usually in an organic binder matrix. It is contained in. The photosensitive material is stable at room temperature, but when heated to a high temperature (for example, 80 ° C. or higher) after exposure, silver is reduced through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and a reducing agent. Generate This oxidation-reduction reaction is promoted by the catalytic action of the latent image generated by the exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image.

[0005] In the printing field, ultra-high contrast photographic properties are desired, and it is proposed in US5496695 to obtain ultra-high contrast performance by using a hydrazine derivative. However, fog during heat development is high and storage stability is high. However, improvement was desired.

[0006] Japanese Patent Application Laid-Open Nos.
-207244, 60-207140, US29
10377, U.S. Pat. No. 3,074,809, JP-A-2-25
No. 1838 discloses salicylic acid or a derivative thereof, but does not disclose any effect in a super-hard dry silver system.

[0007]

Accordingly, an object of the present invention is to provide a photosensitive material which is highly active and excellent in storability for photoengraving (especially for scanners and imagesetters) and for medical images. An object of the present invention is to provide a heat-developable image forming material.

[0008]

This object has been achieved by the following means. (1) a photosensitive silver halide, (b) a reducible silver salt, and (c) on at least one same surface of a support.
A reducing agent, (d) a binder, and (e) at least one of a heteroaromatic mercapto compound and a heteroaromatic disulfide compound in an amount of 10 ^-3 to 1 mol per mol of silver.
And (f) at least one of the compounds represented by formula (1).

[0009]

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[In the formula (1), M represents a hydrogen atom or a k-valent cation, and R represents a substituent. n is 1 to 4
When n ≧ 2, a plurality of Rs may be the same or different. k is an integer of 1 or more, and when M is a hydrogen atom, k = 1. (2) The photothermographic image-forming material according to the above (1), wherein at least one of the heteroaromatic mercapto compound and the heteroaromatic disulfide compound is used as a supersensitizer. (3) The photosensitive heat-developable image-forming material according to the above (1) or (2), having a super-high contrast agent. (4) The photothermographic development according to (3), wherein at least one of a substituted alkene derivative, a substituted isoxazole derivative and a specific acetal compound represented by the following formulas (2) to (4) is used as a super-high contrast agent. Image forming materials.

[0011]

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[In the formula (2), R ¹ , R ² and R
³ independently represent a hydrogen atom or a substituent;
Represents an electron-withdrawing group. In the formula (2), R ¹ and Z, R ²
And R ³ , R ¹ and R ² , and R ³ and Z may be mutually bonded to form a cyclic structure. In the formula (3), R ⁴ represents a substituent. In the formula (4), X and Y
Each independently represents a hydrogen atom or a substituent; A and B each independently represent an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic oxy group, a heterocyclic thio group; Represents a group or a heterocyclic amino group. In equation (4),
X and Y, and A and B may be bonded to each other to form a cyclic structure. (5) The photosensitive heat-developable image-forming material according to any one of the above (1) to (4), having a hydrazine compound.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The photothermographic image-forming material of the present invention (that is, the photothermographic material) has an image-forming layer containing a reducible silver salt and a binder on at least one surface of a support. The layer on the layer side further contains a photosensitive silver halide and a reducing agent, and is mainly a high-contrast material for obtaining a high-contrast image, and therefore preferably contains a super-high contrast agent in the layer on the same side. .

In such an image forming material, at least one compound selected from a heteroaromatic mercapto compound and a disulfide compound is converted to silver 1
By containing the compound represented by the formula (1) in an amount of 10 ^-3 to 1 mol with respect to the mol, an image-forming material having excellent photographic performance and no decrease in photographic performance due to storage can be obtained. On the other hand, when the content of the mercapto compound or the disulfide compound is 10 ⁻³ mol / mol-Ag
If it is less than 1, Dmax and sensitivity decrease, and sufficient photographic performance cannot be obtained. If it exceeds 1 mol / mol-Ag, Dmax and sensitivity will be reduced again. On the other hand, when the compound of the formula (1) is not contained, fog is significantly increased by storage and softening is remarkable. Such deterioration of storage stability becomes remarkable when an attempt is made to obtain sufficient sensitivity by using the mercapto compound or the disulfide compound in a high contrast sensitive material, but the present invention solves this problem.

First, equation (1) used in the present invention will be described in detail. Equation (1) is shown below.

[0016]

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In the formula (1), M is a hydrogen atom or k
It represents a valent cation (for example, a metal ion such as a sodium ion, a potassium ion, a calcium ion, a barium ion, and a zinc ion, and an ammonium ion such as a tetramethylammonium ion and a tetrabutylammonium ion). k is an integer of 1 or more as shown by the exemplified ion, and is usually 1 or 2. When M is a hydrogen atom, k = 1. M is preferably a heavy metal ion, specifically zinc, iron, manganese, cadmium, chromium, cobalt, ruthenium, rhodium, silver and the like.

In the formula (1), R represents a substituent, for example, a linear, branched or cyclic alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 12 carbon atoms).
To 8, for example, methyl, ethyl, iso-propyl, t-butyl, n-octyl, 1,1,3,3-tetramethylbutyl, t-amyl, cyclohexyl and the like. ), Alkenyl groups (preferably having 2 to 2 carbon atoms)
0, more preferably 2 to 12, particularly preferably 2 to 8, for example, vinyl, allyl, 2-butenyl, 3-pentenyl and the like. ), An alkynyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 12 carbon atoms, and particularly preferably 2 to 12 carbon atoms).
To 8, for example, propargyl, 3-pentynyl and the like. ), An aralkyl group (preferably having 7 carbon atoms)
~ 30, more preferably 7 ~ 20, particularly preferably 7 ~
16, for example, benzyl, α-methylbenzyl,
α-ethylbenzyl, diphenylmethyl, naphthylmethyl, naphthylphenylmethyl and the like. ), An aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 carbon atoms)
-20, particularly preferably 6-12, for example, phenyl, p-methylphenyl, naphthyl and the like. ), An amino group (preferably having 0 to 20, more preferably 0 to 10, and still more preferably 0 to 6, for example,
Amino, methylamino, dimethylamino, diethylamino, dibenzylamino and the like can be mentioned. ), An alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 1 carbon atoms)
2, particularly preferably 1 to 8, for example, methoxy,
Ethoxy, butoxy and the like can be mentioned. ), An aryloxy group (preferably having 6 to 20 carbon atoms, more preferably having 6 to 20 carbon atoms)
16, particularly preferably 6 to 12, for example, phenyloxy, 2-naphthyloxy and the like. ), An acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16,
Particularly preferred is 1 to 12, for example, acetyl, benzoyl, formyl, pivaloyl and the like. ),
An alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, for example, methoxycarbonyl, ethoxycarbonyl, etc.), an aryloxycarbonyl group (preferably carbon The number is 7 to 20, more preferably 7 to 16, particularly preferably 7 to 10, and examples thereof include phenoxycarbonyl and the like, and an acyloxy group (preferably having 1 to 20 carbon atoms, more preferably 2 to 16 carbon atoms). Particularly preferably, 2 to 10
And examples thereof include acetoxy and benzoyloxy. ), An acylamino group (preferably having 1 carbon atom)
-20, more preferably 2-16, particularly preferably 2-10, for example, acetylamino, benzoylamino and the like. ), An alkoxycarbonylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as methoxycarbonylamino, etc.), and an aryloxycarbonylamino group (preferably Has 7 to 20 carbon atoms, more preferably 7 carbon atoms
To 16, particularly preferably 7 to 12, and examples include phenyloxycarbonylamino. ), A sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, methanesulfonylamino, benzenesulfonylamino, etc.), a sulfamoyl group (preferably Has 0 to 20, more preferably 0 to 16, and particularly preferably 0 to 12 carbon atoms.
And include, for example, sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl and the like. ), A carbamoyl group (preferably having 0 to 20, more preferably 0 to 16, particularly preferably 0 to 16 carbon atoms)
To 12, for example, carbamoyl, diethylcarbamoyl, phenylcarbamoyl and the like. ), A ureido group (preferably having 1 to 20 carbon atoms, more preferably 1
To 16, particularly preferably 1 to 12, and examples thereof include ureido, methylureide, and phenylurey. ), An alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, methylthio, ethylthio, etc.),
An arylthio group (preferably having 6 to 20, more preferably 6 to 16, particularly preferably 6 to 12, and examples thereof include phenylthio, etc.), a sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably Is 1 to 16, particularly preferably 1 to 12, and examples thereof include mesyl and tosyl.) And a sulfinyl group (preferably having 1 to 1 carbon atoms)
20, more preferably 1 to 16, particularly preferably 1 to 12, for example, methanesulfinyl, benzenesulfinyl and the like. ), A phosphoramide group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 16 carbon atoms).
To 12, for example, diethylphosphoramide, phenylphosphoramide and the like. ), Hydroxy group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxy group, nitro group, hydroxam group, sulfino group, hydrazino group, sulfonylthio group Thiosulfonyl group, heterocyclic group (for example, imidazolyl, pyridyl, furyl, piperidyl, morpholinyl, etc.),
And a disulfide group.

These substituents may be further substituted, and may form a salt if the group is capable of forming a salt. Further, n is an integer of 1 to 4, but when there are two or more substituents, that is, when n ≧ 2, they may be the same or different. n is preferably 1 to 3, and most preferably 2.

These substituents are bonded to each other to form 5
A non-aromatic or aromatic carbon ring (for example, a benzene ring) having a 7 to 7-membered ring may be formed. Further, this ring may be substituted with another substituent (eg, a halogen atom, a carboxy group).

The substituent represented by R is preferably
Alkyl group, alkenyl group, alkynyl group, aralkyl group, aryl group, amino group, alkoxy group, acyl group,
Alkoxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, ureido group, alkylthio group, sulfonyl group, hydroxy group, mercapto group, halogen atom, cyano group, sulfo group, carboxy Group, a nitro group, a heterocyclic group, more preferably an alkyl group, an alkenyl group, an aralkyl group, an amino group, an alkoxy group, an alkylthio group, a hydroxy group,
A mercapto group, a halogen atom, a sulfo group, and a carboxy group.

Further, in the formula (1), it is particularly preferred that the hydroxyl group is substituted with an alkyl group (including an aralkyl group) at the ortho position and / or the para position. Further, a bisphenol structure in which the compound of the formula (1) is bonded via one carbon is more preferable. Next, specific examples of the compound of the present invention are shown, but the present invention is not limited thereto.

[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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As the compound of the formula (1) of the present invention, a commercially available compound may be used. )) Can be easily synthesized by an acid-catalyzed condensation reaction of salicylic acid and a carbonyl compound.

The compound of the formula (1) of the present invention can be prepared from water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethyl sulfoxide, It can be used by dissolving it in methylcellosolve or the like.

Further, by a well-known emulsification dispersion method, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate or an auxiliary solvent such as ethyl acetate or cyclohexanone is used for dissolution, and mechanical An emulsified dispersion can be prepared and used. Alternatively, the powder can be dispersed in water by a ball mill, a colloid mill, a sand grinder mill, a Manton-Gaulin, a microfluidizer, or an ultrasonic wave by a method known as a solid dispersion method.

The compound of the formula (1) of the present invention may be added to the layer on the image forming layer side with respect to the support, that is, the image forming layer or any other layer on the layer side. Alternatively, it is preferably added to a layer adjacent thereto. The image forming layer is a layer containing a reducible silver salt (organic silver salt), and is preferably a photosensitive layer further containing a photosensitive silver halide.

The amount of the compound of the formula (1) of the present invention is
Shown in mol per mol of mol (mol / mol-Ag), preferred
1x10^-Five~ 5 × 10^-1mol / mol-Ag, more preferred
H, 5 × 10^-Five~ 1 × 10^-1mol / molAg, more preferred
H, 1 × 10^-Four~ 5 × 10 ^-2mol / mol-Ag. This
These may be used alone or in combination of two or more.

The substituted alkene derivatives represented by the formulas (2) to (4) which are preferably used as a super-high contrast agent in the present invention:
The substituted isoxazole derivative and the specific acetal compound will be described.

[0035]

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In the formula (2), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent, and Z represents an electron-withdrawing group. In the formula (2), R ¹ and Z, R ² and R ³ , R ¹ and R ² , or R ³ and Z may be bonded to each other to form a cyclic structure. In the formula (3), R ⁴ represents a substituent. In the formula (4), X and Y each independently represent a hydrogen atom or a substituent, and A and B each independently represent an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic group. Represents an oxy group, a heterocyclic thio group, or a heterocyclic amino group. In the formula (4), X and Y or A and B may be bonded to each other to form a cyclic structure.

In the formula (2), when R ¹ , R ² and R ³ represent a substituent, examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom or an iodine atom),
Alkyl group (including aralkyl group, cycloalkyl group, active methine group, etc.), alkenyl group, alkynyl group, aryl group, heterocyclic group (including N-substituted nitrogen-containing heterocyclic group), quaternized nitrogen A heterocyclic group containing an atom (eg, a pyridinio group), an acyl group, an alkoxycarbonyl group,
An aryloxycarbonyl group, a carbamoyl group, a carboxy group or a salt thereof, an imino group, an imino group substituted with an N atom, a thiocarbonyl group, a sulfonylcarbamoyl group,
Acyl carbamoyl group, sulfamoyl carbamoyl group, carbazoyl group, oxalyl group, oxamoyl group,
A cyano group, a thiocarbamoyl group, a hydroxy group or a salt thereof, an alkoxy group (including a group having a repeating ethyleneoxy or propyleneoxy group unit), an aryloxy group, a heterocyclic oxy group, an acyloxy group, (alkoxy or aryloxy) Carbonyloxy group,
A carbamoyloxy group, a sulfonyloxy group, an amino group, an (alkyl, aryl, or heterocycle) amino group, an acylamino group, a sulfonamide group, a ureido group,
Thioureido group, isothioureido group, imide group, (alkoxy or aryloxy) carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, hydrazino group, quaternary ammonium group, oxamoylamino group, (alkyl or aryl ) Sulfonylureido, acylureido, acylsulfamoylamino, nitro, mercapto,
(Alkyl, aryl, or heterocycle) thio, acylthio, (alkyl or aryl) sulfonyl,
(Alkyl or aryl) sulfinyl group, sulfo group or salt thereof, sulfamoyl group, acylsulfamoyl group, sulfonylsulfamoyl group or salt thereof, phosphoryl group, group having a phosphoric acid amide or phosphate ester structure, silyl group, And a stannyl group.

These substituents may be further substituted with these substituents.

The electron-withdrawing group represented by Z in the formula (2) is a substituent whose Hammett's substituent constant σp can take a positive value, and specifically includes a cyano group and an alkoxycarbonyl group. Group, aryloxycarbonyl group, carbamoyl group, imino group, imino group substituted with an N atom, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, halogen atom,
Perfluoroalkyl group, perfluoroalkaneamide group, sulfonamide group, acyl group, formyl group, phosphoryl group, carboxy group, sulfo group (or salt thereof), heterocyclic group, alkenyl group, alkynyl group, acyloxy group, acylthio group , A sulfonyloxy group, or an aryl group substituted with these electron-withdrawing groups. Here, the heterocyclic group is an aromatic or non-aromatic, saturated or unsaturated heterocyclic group, for example, a pyridyl group, a quinolyl group, a quinoxalinyl group, a pyrazinyl group, a benzotriazolyl group, an imidazolyl group, a benzimidazolyl group. Groups, hydantoin-1-yl group, urazol-1-yl group, succinimide group, phthalimide group and the like. The electron-withdrawing group represented by Z in the formula (2) may further have an arbitrary substituent.

The electron-withdrawing group represented by Z in the formula (2) is preferably a group having the following total number of carbon atoms of 0 to 30, that is, a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a thiol group. Carbonyl group,
Imino group, imino group substituted with N atom, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, perfluoroalkyl group, acyl group, formyl group, phosphoryl group, acyloxy group, acylthio group, or any electron withdrawing And a phenyl group substituted with a functional group, more preferably a cyano group, an alkoxycarbonyl group, a carbamoyl group, a thiocarbonyl group, an imino group,
An imino group substituted with an N atom, a sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, an acyl group, a formyl group, a phosphoryl group, a trifluoromethyl group, or a phenyl group substituted with any electron-withdrawing group; Particularly preferably, a cyano group, an alkoxycarbonyl group, a carbamoyl group, an imino group, an imino group substituted by an N atom, an alkylsulfonyl group, an arylsulfonyl group,
An acyl group or a formyl group.

In the formula (2), the substituent represented by R ¹ is preferably a group having a total carbon number of 0 to 30, specifically, an electron-withdrawing group represented by Z in the above formula (2). A group synonymous with
And alkyl, alkenyl, alkoxy, aryloxy, heterocyclic oxy, alkylthio, arylthio, heterocyclic thio, amino, alkylamino, arylamino, heterocyclic amino, ureido, acylamino Group, silyl group, or substituted or unsubstituted aryl group, more preferably
A group having the same meaning as the electron-withdrawing group represented by Z in (2), a hydrogen atom, a substituted or unsubstituted aryl group, an alkenyl group,
An alkylthio group, an arylthio group, an alkoxy group, a silyl group, or an acylamino group, more preferably an electron-withdrawing group, an aryl group, an alkenyl group, or an acylamino group.

When R ¹ represents an electron-withdrawing group, its preferred range is the same as the preferred range of the electron-withdrawing group represented by Z.

In the formula (2), the substituent represented by R ² and R ³ is preferably a group having the same meaning as the electron-withdrawing group represented by Z in the above formula (2), an alkyl group or a hydroxy group.
(Or salt thereof), mercapto group (or salt thereof), alkoxy group, aryloxy group, heterocyclic oxy group, alkylthio group, arylthio group, heterocyclic thio group, amino group, alkylamino group, anilino group, heterocyclic amino Group, acylamino group, substituted or unsubstituted phenyl group and the like. R ² and R ³ are more preferably when one of them is a hydrogen atom and the other represents a substituent. As the substituent, preferably an alkyl group, a hydroxy group
(Or salt thereof), mercapto group (or salt thereof), alkoxy group, aryloxy group, heterocyclic oxy group, alkylthio group, arylthio group, heterocyclic thio group, amino group, alkylamino group, anilino group, heterocyclic amino Group, an acylamino group (particularly a perfluoroalkaneamide group), a sulfonamide group, a substituted or unsubstituted phenyl group, or a heterocyclic group, and more preferably a hydroxy group (or a salt thereof), a mercapto group (or a salt thereof). ), An alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group, or a heterocyclic group, particularly preferably a hydroxy group (or a salt thereof), an alkoxy group, or It is a heterocyclic group.

In the formula (2), Z and R ¹ , or R ²
It is also preferred that and R ³ form a cyclic structure. The cyclic structure formed in this case is a non-aromatic carbocyclic or non-aromatic heterocyclic ring, preferably a 5- to 7-membered cyclic structure having a total carbon number including a substituent of 1 to 7. 4
0, more preferably 3 to 35.

Among the compounds represented by the formula (2), one of the more preferred ones is that Z represents a cyano group, formyl group, acyl group, alkoxycarbonyl group, imino group or carbamoyl group, and R ¹ is Represents an electron withdrawing group, one of R ^{2 and} R ³ is a hydrogen atom, and the other is a hydroxy group (or a salt thereof), a mercapto group (or a salt thereof), an alkoxy group, an aryloxy group, a heterocyclic oxy group , An alkylthio group, an arylthio group, a heterocyclic thio group, an amino group, or a heterocyclic group.

Further, among the compounds represented by the formula (2),
One of the more preferred is Z and R¹Is linked to non
Forming an aromatic 5- to 7-membered cyclic structure,^TwoMa
Or R ^ThreeOne is a hydrogen atom and the other is a hydroxy
Group (or its salt), mercapto group (or its salt),
Alkoxy group, aryloxy group, heterocyclic oxy group,
Alkylthio group, arylthio group, heterocyclic thio group,
And a compound that represents a heterocyclic group or a heterocyclic group.

Here, the non-aromatic 5 formed by Z and R ¹
The 7-membered to 7-membered cyclic structure is specifically indane-1,3-
Dione ring, pyrrolidine-2,4-dione ring, pyrazolidine-3,5-dione ring, oxazolidine-2,4-dione ring, 5-pyrazolone ring, imidazolidine-2,4-dione ring, thiazolidine-2,4 A dione ring, an oxolane-2,4-dione ring, a thiolane-2,4-dione ring,
1,3-dioxane-4,6-dione ring, cyclohexane-1,3-dione ring, 1,2,3,4-tetrahydroquinoline-2,4-dione ring, cyclopentane-1,3
A dione ring, an isoxazolidine-3,5-dione ring,
Barbituric acid ring, 2,3-dihydrobenzofuran-3
-One ring, pyrazolotriazole ring (for example, 7H-pyrazolo [1,5-b] [1,2,4] triazole, 7H
-Pyrazolo [5,1-c] [1,2,4] triazole, 7H-pyrazolo [1,5-a] benzimidazole and the like, pyrrolotriazole ring (for example, 5H-pyrrolo [1,2-b] [1 , 2,4] triazole, 5H-pyrrolo [2,1-c] [1,2,4] triazole and the like),
2-cyclopentene-1,4-dione ring, 2,3-dihydrobenzothiophen-3-one-1,1-dioxide ring, chroman-2,4-dione ring, 2-oxazoline-
5-one ring, 2-imidazolin-5-one ring, 2-thiazolin-5-one ring, 1-pyrrolin-4-one ring, 5-
Oxothiazolidine-2-thione ring, 4-oxothiazolidine-2-thione ring, pyrrolopyrimidinone ring, 1,3
-Dithiolane ring, thiazolidine ring, 1,3-dithiethane ring, 1,3-dioxolane ring and the like, among which indane-1,3-dione ring, pyrrolidine-2,4-dione ring, pyrazolidine-3,5- A dione ring, 5-pyrazolone ring, barbituric acid ring, 2-oxazolin-5-one ring and the like are preferable.

Examples of the substituent represented by R ⁴ in the formula (3) are the same as those described for the substituents R ^{1 to} R ^{3 in} the formula (2).

In the formula (3), the substituent represented by R ⁴ is
Preferably, it is an electron-withdrawing group or an aryl group. R ⁴
When represents an electron-withdrawing group, the total carbon number is preferably 0 to 3
The following groups of 0: a cyano group, a nitro group, an acyl group,
A formyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl group, a sulfamoyl group, a perfluoroalkyl group, a phosphoryl group, an imino group, a sulfonamide group, or a heterocyclic group; Group, acyl group, formyl group, alkoxycarbonyl group, carbamoyl group, sulfamoyl group, alkylsulfonyl group,
An arylsulfonyl group, a sulfonamide group and a heterocyclic group are preferred.

[0050] When R ⁴ represents an aryl group, preferably a total carbon number of 0 to 30, a substituted or unsubstituted phenyl group, the substituent, R ^1, R ^2, R ³ of formula (2) When represents a substituent, the same as those described as the substituent can be mentioned, but an electron-withdrawing group is preferable.

As the substituents represented by X and Y in the formula (4), the same as those described for the substituents R ^{1 to} R ^{3 in} the formula (2) can be mentioned. The substituent represented by X or Y is preferably a group having 1 to 50 total carbon atoms, more preferably a group having 1 to 35 total carbon atoms, and is a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, Imino group, imino group substituted by N atom, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group,
Arylsulfonyl group, nitro group, perfluoroalkyl group, acyl group, formyl group, phosphoryl group, acylamino group, acyloxy group, acylthio group, heterocyclic group,
Preferred are an alkylthio group, an alkoxy group, an aryl group, and the like. More preferably substituted with a cyano group, nitro group, alkoxycarbonyl group, carbamoyl group, acyl group, formyl group, acylthio group, acylamino group, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, imino group, N atom Imino group, a phosphoryl group, a trifluoromethyl group, a heterocyclic group, or a substituted phenyl group, and particularly preferably a cyano group, an alkoxycarbonyl group, a carbamoyl group, an alkylsulfonyl group, an arylsulfonyl group, an acyl group, Examples include an acylthio group, an acylamino group, a thiocarbonyl group, a formyl group, an imino group, an imino group substituted with an N atom, a heterocyclic group, and a phenyl group substituted with any electron-withdrawing group.

It is also preferred that X and Y combine with each other to form a non-aromatic carbon ring or a non-aromatic hetero ring. At this time, the formed ring is preferably a 5- to 7-membered ring, and specifically, a non-aromatic 5- to 7-membered ring which can be formed by bonding Z and R ¹ of the formula (2) to each other. The same examples are given, and their preferred ranges are also the same. These rings may further have a substituent, and the total carbon number is preferably 1 to 40, more preferably 1 to 35.

In the formula (4), the groups represented by A and B are
Further, it may have a substituent, and is preferably a group having 1 to 40 carbon atoms in total, more preferably a group having 1 to 30 carbon atoms in total.

In the formula (4), A and B are
More preferably when they are linked to
No. The cyclic structure formed at this time is a 5- to 7-membered non-aromatic ring
Group heterocycles are preferred, having a total carbon number of 1 to 40,
These are preferably 3 to 30. In this case, A and B are connected
For example, -O- (C
H_Two)_Two-O-, -O- (CH_Two)_Three-O-, -S- (CH
_Two)_Two-S-, -S- (CH_Two)_Three-S-, -S-ph-S
-, -N (CH_Three)-(CH_Two)_Two-O-, -N (CH _Three)
− (CH_Two)_Two-S-, -O- (CH_Two)_Two-S-, -O-
(CH_Two)_Three-S-, -N (CH_Three) -Ph-O-,-N
(CH_Three) -Ph-S-,-N (ph)-(CH_Two)_Two−
S- and so on.

The compounds represented by formulas (2) to (4) of the present invention may have incorporated therein an adsorptive group that adsorbs to silver halide. A ballast group or a polymer commonly used in immobile photographic additives such as couplers may be incorporated, and a cationic group (specifically, a group containing a quaternary ammonium group, or Nitrogen-containing heterocyclic group containing a graded nitrogen atom), a group containing a repeating unit of an ethyleneoxy group or a propyleneoxy group, an (alkyl, aryl, or heterocyclic) thio group, or a dissociable group dissociable by a base Groups (carboxy group, sulfo group, acylsulfamoyl group, carbamoylsulfamoyl group, etc.). Examples of these groups include, for example, JP-A-63-29751,
U.S. Pat. Nos. 4,385,108 and 4,459,34
7, JP-A-59-195233 and JP-A-59-2002.
No. 31, No. 59-201045, No. 59-20104
No. 6, No. 59-201047, No. 59-201048
No. 59-201049, JP-A-61-17073.
Nos. 3, 61-270744, 62-948, 63-234244, 63-234245, and 6
JP-A-3-234246, JP-A-2-285344, JP-A-1-100530, JP-A-7-234471, JP-A-5-333466, JP-A-6-19032, JP-A-6-19031, JP-A-5 No. 4,576,361, U.S. Pat. No. 4,994,365, U.S. Pat. No. 4,988,604, JP-A-3-259240, JP-A-7-5610, JP-A-7-244348, and German Patent 4006032.

Next, specific examples of the compounds represented by the formulas (2) to (4) of the present invention are shown below. However, the present invention is not limited to the following compounds.

[0057]

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[0058]

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[0059]

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[0060]

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The compounds represented by the formulas (2) to (4) can be easily synthesized by known methods.
US Pat. No. 5,545,515, US Pat. No. 5,635,339
No. 5,654,130, International Patent WO-97 /
The compounds can be synthesized with reference to the methods described in Japanese Patent Application No. 34196, Japanese Patent Application No. 9-354107, Japanese Patent Application No. 9-309813, and Japanese Patent Application No. 9-272002.

The compounds represented by the formulas (2) to (4) of the present invention may be used alone or in combination of two or more.
In addition to the above, US Pat. No. 5,545,515, US Pat. No. 5,635,339, US Pat.
Compounds described in U.S. Pat. No. 5,705,324 and U.S. Pat. No. 5,686,228 or JP-A-10-161270
No. 9-273935, Japanese Patent Application No. 9-35410
7, Japanese Patent Application No. 9-309813, Japanese Patent Application No. 9-2961
No. 74, Japanese Patent Application No. 9-282564, Japanese Patent Application No. 9-272
002, Japanese Patent Application No. 9-272003, Japanese Patent Application No. 9-33
The compounds described in No. 2388 may be used in combination.

Further, according to the present invention, a method disclosed in
Various hydrazine derivatives described in 61270 can also be used in combination.

The compounds represented by the formulas (2) to (4) of the present invention can be prepared by using water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol) and ketones (acetone, methyl ethyl ketone). ), Dimethylformamide, dimethylsulfoxide,
It can be used by dissolving it in methylcellosolve or the like.

Further, by a well-known emulsification and dispersion method, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone is used to dissolve and dissolve mechanically. An emulsified dispersion can be prepared and used. Alternatively, a compound powder can be dispersed in a suitable solvent such as water by a ball mill, a colloid mill, or ultrasonic waves by a method known as a solid dispersion method and used.

The compounds represented by formulas (2) to (4) of the present invention are added to the layer on the image forming layer side with respect to the support, that is, the image forming layer or any other layer on this layer side. May be
It is preferably added to the image forming layer or a layer adjacent thereto.

The addition amount of the compounds represented by the formulas (2) to (4) of the present invention is preferably 1 × 10 ⁻⁶ to 1 mol per 1 mol of silver, and 1 × 10 ^{−5 to} 5 × 10 5 ^-1 mol is more preferred,
The amount is most preferably 2 × 10 ^{-5 to} 2 × 10 ^-1 mol.

In the present invention, a hydrazine compound can be used as a super-high contrast agent and a nucleation accelerator (high contrast accelerator).
No. 57, and hydrazine derivatives described in Japanese Patent Application No. 9-240511 can be used. Further, the following hydrazine derivatives can be used. That is, 6-77
No. 138, specifically the compounds described on pages 3 and 4 of the same publication. 6-93
No. 082, specifically, compounds 1 to 38 described on pages 8 to 18 of the same publication. Compounds represented by formulas (4), (5) and (6) described in JP-A-6-230497.
Compounds 4-1 to 4-10 described on page 5, page 26,
Compounds 5-1 to 5-42 described on pages 28 to 36, and compounds 6-1 to 6- described on pages 39 and 40
7. Compounds represented by formulas (1) and (2) described in JP-A-6-289520, specifically, from page 5 to
Compounds 1-1) to 1-17) and 2-
1). Compounds represented by (Chemical Formula 2) and (Chemical Formula 3) described in JP-A-6-313936, specifically, compounds described on pages 6 to 19 of the same. Compounds represented by (Chemical Formula 1) described in JP-A-6-313951, specifically, compounds described on pages 3 to 5 of the same. A compound represented by the formula (I) described in JP-A-7-5610.
Compounds I-1 to I-38 described on pages 10 to 10. JP 7
-77783, a compound represented by the formula (II),
Specifically, compound II-1 described on pages 10 to 27 of the publication
~ II-102. Compounds represented by formulas (H) and (Ha) described in JP-A-7-104426, specifically, compounds H-1 to H-4 described on pages 8 to 15 of the same publication
4. EP-A-713131A is a compound characterized by having an anionic group or a nonionic group forming an intramolecular hydrogen bond with a hydrogen atom of hydrazine in the vicinity of a hydrazine group. B), compounds represented by formula (C), formula (D), formula (E), and formula (F), specifically, compounds N-1 to N-3 described in the same publication
0. A compound represented by the formula (1) described in EP 713131A, specifically, a compound D-1 described in the publication
~ D-55.

Further, “Known Techniques (1 to
207) ”(Aztec Co., Ltd.), pp. 25-34. Compounds D-2 and D-39 of JP-A-62-86354 (pages 6 to 7).

These hydrazine derivatives are dissolved in water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methylethylketone), dimethylformamide, dimethylsulfoxide, methylcellosolve and the like. Can be used.

Further, by a well-known emulsification and dispersion method, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate or an auxiliary solvent such as ethyl acetate or cyclohexanone is used for dissolution, and mechanical An emulsified dispersion can be prepared and used. Alternatively, a powder of a hydrazine derivative can be dispersed in water by a ball mill, a colloid mill, or an ultrasonic wave by a method known as a solid dispersion method and used.

These hydrazine derivatives may be added to the layer on the image forming layer side with respect to the support, that is, to the image forming layer or any other layer, but may be added to the image forming layer or a layer adjacent thereto. preferable.

The addition amount of these hydrazine derivatives is preferably 1 × 10 ⁻⁶ to 1 mol per 1 mol of silver, and more preferably 1 × 10 ⁻⁵ to 1 × 10 ⁻⁵ .
5 × 10 ^-1 mol is more preferred, and 2 × 10 ^-5 to 2 × 10
^-1 mole is most preferred.

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

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

Next, the photosensitive silver halide used in the present invention will be described in detail. The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition,
Silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide can be used. The distribution of the halogen composition in the grains may be uniform, the halogen composition may change stepwise, or may change continuously. Further, silver halide grains having a core / shell structure can be preferably used. As the structure, core / shell particles having preferably a 2- to 5-layer structure, more preferably a 2- to 4-layer structure, can be used. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.

The method of forming the photosensitive silver halide in the present invention is well known in the art, and uses, for example, the methods described in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. be able to. Specific methods that can be used in the present invention include a method of converting a part of the silver of the organic silver salt to a photosensitive silver halide by adding a halogen-containing compound to the prepared organic silver salt, gelatin. Alternatively, a method in which a silver supply compound and a halogen supply compound are added to another polymer solution to prepare photosensitive silver halide grains and mixed with an organic silver salt can be used. In the present invention, the latter method can be preferably used. The particle size of the photosensitive silver halide is preferably small for the purpose of suppressing the white turbidity after image formation to be low.
20 μm or less, more preferably 0.01 μm or more and 0.15 μm or less,
More preferably, the thickness is 0.02 μm or more and 0.12 μm or less. Here, the grain size means the length of the edge of the silver halide grain when the silver halide grain is a cubic or octahedral so-called normal crystal. In the case where the silver halide grains are tabular grains, the diameter refers to the diameter when converted into a circular image having the same area as the projected area of the main surface. In the case of other than normal crystals, for example, in the case of spherical grains, rod-shaped grains, etc., it refers to the diameter of a sphere equivalent to the volume of silver halide grains.

The shape of the silver halide grains is cubic,
Octahedral, tabular particles, spherical particles, rod-like particles, potato-like particles and the like can be mentioned. In the present invention, cubic particles and tabular particles are particularly preferable. When tabular silver halide grains are used, the average aspect ratio is preferably 100: 1 to 2: 1, more preferably 50: 1 to 3: 1. Further, grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grains is not particularly limited, but the spectral sensitizing efficiency when a spectral sensitizing dye is adsorbed is high.
The proportion occupied by the [100] plane is preferably high. The ratio is preferably 50% or more, more preferably 65% or more,
80% or more is more preferable. The Miller index [100] plane ratio was determined by T. Tani; J. Imaging Sci., 29, 165 (1985), which utilizes the adsorption dependence of [111] and [100] planes on the adsorption of sensitizing dyes. It can be determined by the method described.

The light-sensitive silver halide grains used in the present invention are selected from groups VII and VIII (groups 7 to 7) of the periodic table.
It preferably contains a metal of Group 10) or a metal complex. Rhodium, rhenium, ruthenium, osmium and iridium are preferred as the metal of Group VII or VIII of the periodic table or the central metal of the metal complex. One type of these metal complexes may be used, or two or more types of complexes of the same metal and different metals may be used in combination. The preferred content is in the range of 10 ^-9 mol to 10 ^-2 mol, preferably 10 ^-8 mol to 10 ^-4 mol, per mol of silver.
As a specific structure of the metal complex, a metal complex having a structure described in JP-A-7-225449 or the like can be used.

As the rhodium compound preferably used in the present invention, a water-soluble rhodium compound can be used. For example, a rhodium (III) halide compound or a rhodium complex salt having a ligand such as halogen, amines, oxalate, etc., for example, hexachlororhodium (III) complex salt, pentachloroacolodium (III) complex salt,
Tetrachlorodiachodium (III) complex salt, hexabromorhodium (III) complex salt, hexaamminerhodium (II)
I) complex salts and trizalatrodium (III) complex salts. These rhodium compounds are used by dissolving them in water or a suitable solvent. A method generally used to stabilize a solution of the rhodium compound, that is, a hydrogen halide aqueous solution (for example, hydrochloric acid, hydrobromic acid, hydrofluoric acid) etc),
Alternatively, an alkali halide (eg, KCl, NaCl, KBr,
NaBr) can be used. Instead of using water-soluble rhodium, it is also possible to add and dissolve other silver halide grains doped with rhodium during the preparation of silver halide.

The amount of these rhodium compounds added is
1 × 10 per mole of silver halide^-8Mol ~ 5 x 10^-6Mole of
The range is preferably, particularly preferably 5 × 10^-8Mol ~ 1x
10 ^-6Is a mole.

These compounds can be appropriately added at the time of production of silver halide emulsion grains and at each stage before coating the emulsion.
It is preferably incorporated into silver halide grains.

Rhenium, ruthenium and osmium preferably used in the present invention are described in JP-A-63-2042 and JP-A-1-2859.
It is added in the form of a water-soluble complex salt described in JP-A Nos. 41, 2-20852, 2-20855 and the like. Particularly preferred is a six-coordinate complex represented by the following formula. [ML ₆ ] ⁿ -where M represents Ru, Re, or Os, L represents a ligand, and n represents 0, 1, 2, 3, or 4.

In this case, the counter ion is not important, and an ammonium or alkali metal ion is used.

Preferred ligands include halide ligands, cyanide ligands, cyanide ligands, nitrosyl ligands, thionitrosyl ligands and the like.
Examples of specific complexes used in the present invention are shown below, but the present invention is not limited thereto.

[ReCl ₆ ] ^3- [ReBr ₆ ] ^3- [ReCl ₅ (NO)] ^2- [Re (NS) Br ₅ ] ^2- [Re (NO) (CN) ₅ ] ^2- [Re (O ) ₂ (CN) ₄ ] ^3- [RuCl ₆ ] ^3- [RuCl ₄ (H ₂ O) ₂ ] ^- [RuCl ₅ (H ₂ O)] ^2- [RuCl ₅ (NO)] ^2- [RuBr ₅ ( NS)] ^2- [Ru (CO) ₃ Cl ₃ ] ^2- [Ru (CO) Cl ₅ ] ^2- [Ru (CO) Br ₅ ] ^2- [OsCl ₆ ] ^3- [OsCl ₅ (NO)] ^{2 -} [Os (NO) (CN) ₅ ] ^2- [Os (NS) Br ₅ ] ^2- [Os (O) ₂ (CN) ₄ ] ^4-

The addition amount of these compounds is 1
It is preferably in the range of 1 × 10 ⁻⁹ mol to 1 × 10 ⁻⁵ mol per mol, particularly preferably 1 × 10 ⁻⁸ mol to 1 × 10 ⁻⁶ mol.

These compounds can be appropriately added at the time of production of silver halide emulsion grains and at each stage before coating the emulsion.
It is preferably incorporated into silver halide grains.

In order to add these compounds during the formation of silver halide grains and incorporate them into silver halide grains, a metal complex powder or an aqueous solution dissolved together with NaCl and KCl is added to the aqueous solution during grain formation. A method in which silver halide grains are added to a salt or a water-soluble halide solution, or as a third solution when a silver salt and a halide solution are mixed at the same time, and a three-liquid simultaneous mixing method is used, Alternatively, there is a method in which a required amount of an aqueous solution of a metal complex is charged into a reaction vessel during particle formation. Especially powder or NaCl, KCl
Is preferable to add an aqueous solution dissolved together with the above to a water-soluble halide solution.

For addition to the surface of the particles, a required amount of an aqueous solution of a metal complex may be charged into the reaction vessel immediately after the formation of the particles, during or during physical ripening, or at the time of chemical ripening.

As the iridium compound preferably used in the present invention, various compounds can be used. Examples thereof include hexachloroiridium, hexaammineiridium, trioxalatoiridium, hexacyanoiridium, and pentachloronitrosyliridium. These iridium compounds are used after being dissolved in water or a suitable solvent. However, a method generally used for stabilizing a solution of the iridium compound, that is, an aqueous solution of hydrogen halide (for example, hydrochloric acid, hydrobromic acid, hydrofluoric acid) is used. Etc.) or alkali halides (eg KCl, NaCl, KBr, NaBr, etc.)
Can be used. Instead of using water-soluble iridium, it is also possible to add and dissolve another iridium-doped silver halide grain during silver halide preparation.

The silver halide grains used in the present invention may further include cobalt, iron, nickel, chromium, palladium,
It may contain metal atoms such as platinum, gold, thallium, copper and lead. For compounds of cobalt, iron, chromium and ruthenium, hexacyano metal complexes can be preferably used. Specific examples include ferricyanate ion, ferrocyanate ion, hexacyanocobaltate ion,
Examples include, but are not limited to, hexacyanochromate ions, hexacyanoruthenate ions, and the like. The metal complex in the silver halide may be contained uniformly, may be contained in the core portion at a high concentration, or may be contained in the shell portion at a high concentration, and there is no particular limitation.

The above metal is 1 × per mole of silver halide.
It is preferably from 10 ^-9 to 1 × 10 ^-4 mol. Further, in order to contain the above-mentioned metal, a metal salt in the form of a single salt, a double salt or a complex salt can be added at the time of preparing particles.

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

The silver halide emulsion of the present invention is preferably chemically sensitized. As the method of chemical sensitization, known methods such as a sulfur sensitization method, a selenium sensitization method, a tellurium sensitization method, and a noble metal sensitization method can be used, and these are used alone or in combination. When used in combination,
For example, sulfur sensitization and gold sensitization, sulfur sensitization and selenium sensitization and gold sensitization, sulfur sensitization and tellurium sensitization and gold sensitization, and sulfur sensitization and selenium sensitization Method, tellurium sensitization method, gold sensitization method and the like are preferable.

The sulfur sensitization used in the present invention is usually carried out by
Add a yellow sensitizer and keep the emulsion at a high temperature of 40 ° C or more.
It is performed by stirring for a while. Public sulfur sensitizer
Known compounds can be used, for example, in gelatin
In addition to the sulfur compounds contained in, various sulfur compounds, such as
Thiosulfate, thioureas, thiazoles, rhodanine
Can be used. Preferred sulfur compounds are
Osulfates and thiourea compounds. Amount of sulfur sensitizer added
Indicates the pH, temperature, and size of silver halide grains during chemical ripening
Changes under various conditions, such as silver halide.
10 per mole ^-7-10^-2Mole, more preferably
10^-Five-10^-3Is a mole.

As the selenium sensitizer used in the present invention, known selenium compounds can be used. That is, it is usually carried out by adding an unstable and / or non-unstable selenium compound and stirring the emulsion at a high temperature of 40 ° C. or higher for a certain time. As unstable selenium compounds, JP-B-44-15748, JP-B-43-13489, JP-A-4-25832,
The compounds described in JP-A Nos. 4-109240 and 4-324855 can be used. In particular, the formula (VIII) in JP-A-4-324855 and
It is preferable to use the compound represented by (IX).

The tellurium sensitizer used in the present invention is a compound which forms silver telluride which is presumed to be a sensitizing nucleus on the surface or inside of silver halide grains. The formation rate of silver telluride in a silver halide emulsion is described in JP-A-5-3132.
It can be tested by the method described in No. 84. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, P = Te Compounds having a bond, tellurocarboxylates, Te-organyltellurocarboxylates, di (poly) tellurides, tellurides, tellurols, telluroacetals,
Tellurosulfonates, compounds having a P-Te bond, containing T
e Heterocycles, tellurocarbonyl compounds, inorganic tellurium compounds, colloidal tellurium, and the like can be used. Specifically, U.S. Patent Nos. 1,623,499, 3,320,069, 3,772,031, UK Patent 235,211 and 1,121,496,
No. 1,295,462, No. 1,396,696, Canadian Patent 800,9
No. 58, JP-A-4-204640, JP-A-3-53693, JP-A-3-31598
No. 4-129787, Journal of Chemical Society Chemical Communication (J. Chem.S.
oc.Chem.Commun.) 635 (1980), ibid 1102 (1979), ibid 6
45 (1979), Journal of Chemical Society Perkin Transaction (J. Chem. Soc. Perkin.
Trans.) 1,2191 (1980), edited by S. Patai, The Chemistry of Organ, Selenium and Tellurium Campounds
ic Serenium and Tellunium Compounds), Vol. 1 (1986),
The compounds described in Vol. 2 (1987) can be used.
Particularly, compounds represented by formulas (II), (III) and (IV) in JP-A-5-313284 are preferred.

The amount of the selenium and tellurium sensitizers used in the present invention varies depending on the silver halide grains to be used, the conditions of chemical ripening, and the like, but generally ranges from 10 ^-8 to 10 ^-2 mol per mol of silver halide. Preferably, about 10 ^-7 to 10 ^-3 mol is used. The conditions of the chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, the pAg is 6 to 11, preferably 7 to 10, and the temperature is 40 to 95 ° C, preferably 45 to 45 ° C. 85 ° C.

The noble metal sensitizer used in the present invention includes gold, platinum, palladium, iridium and the like, and gold sensitization is particularly preferable. Specific examples of the gold sensitizer used in the present invention include chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, and gold sulfide, and 10 ^-7 to 10 ^-2 mol per mol of silver halide. Degrees can be used.

In the silver halide emulsion used in the present invention, a cadmium salt, a sulfite, a lead salt, a thallium salt and the like may coexist in the process of forming silver halide grains or physical ripening.

In the present invention, reduction sensitization can be used. As specific compounds of the reduction sensitization method, in addition to ascorbic acid and thiourea dioxide, for example, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds and the like can be used. . Also, when the pH of the emulsion is 7 or more or p
Reduction sensitization can be achieved by aging while keeping Ag at 8.3 or less. Further, reduction sensitization can be achieved by introducing a single addition portion of silver ion during grain formation.

The silver halide emulsion of the present invention may be added with a thiosulfonic acid compound by the method described in EP 293,917.

The photosensitive heat-developable image-forming material used in the present invention may contain only one type of silver halide emulsion or two or more types thereof (for example, those having different average grain sizes, those having different halogen compositions, those having different crystal habits). And those having different chemical sensitization conditions).

The amount of the photosensitive silver halide to be used in the present invention is preferably 0.01 mol to 0.5 mol, more preferably 0.02 mol to 0.3 mol, more preferably 0.03 mol to 1 mol of the organic silver salt. It is particularly preferably at least 0.25 mol and not more than 0.25 mol. Regarding the mixing method and mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the prepared silver halide particles and the organic silver salt were mixed with a high-speed stirrer, ball mill, sand mill, colloid mill, vibration mill, homogenizer, etc. And the like, or a method of preparing an organic silver salt by mixing photosensitive silver halide prepared at any timing during the preparation of the organic silver salt, and the like,
There is no particular limitation as long as the effects of the present invention are sufficiently exhibited.

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

A silver salt of a compound containing a mercapto group or a thione group and derivatives thereof can also be used.
Preferred examples of these compounds include 3-mercapto-4
-Phenyl-1,2,4-triazole silver salt, 2-mercaptobenzimidazole silver salt, 2-mercapto-5-aminothiadiazole silver salt, 2- (ethylglycolamide) benzothiazole silver salt, S- Silver salts of thioglycolic acid such as silver salts of alkylthioglycolic acid (where the alkyl group has 12 to 22 carbon atoms), silver salts of dithiocarboxylic acids such as silver salts of dithioacetic acid, silver salts of thioamides, 5 Silver salt of -carboxyl-1-methyl-2-phenyl-4-thiopyridine, silver salt of mercaptotriazine, silver salt of 2-mercaptobenzoxazole, silver salt described in U.S. Pat.No. 4,123,274, for example, 3-amino-5 Silver salts of 1,2,4-mercaptothiazole derivatives such as -benzylthio-1,2,4-thiazole silver salt, 3- (3-carboxyethyl) -4- described in U.S. Pat.No. 3,301,678
Includes silver salts of thione compounds such as silver salt of methyl-4-thiazoline-2-thione. Further, compounds containing an imino group can also be used. Preferred examples of these compounds include silver salts of benzotriazole and derivatives thereof,
For example, silver salts of benzotriazole such as silver methylbenzotriazole, silver salts of halogen-substituted benzotriazole such as silver 5-chlorobenzotriazole, U.S. Pat.
0,709, 1,2,4-triazole or 1-H-
Includes silver salts of tetrazole, silver salts of imidazole and imidazole derivatives, and the like. For example, U.S. Pat.
Various silver acetylide compounds as described in No. 1 and 4,775,613 can also be used.

The shape of the organic silver salt that can be used in the present invention is not particularly limited, but needle crystals having a short axis and a long axis are preferred. In the present invention, the minor axis is 0.01 μm or more and 0.2 μm or more.
0 μm or less, major axis of 0.10 μm or more and 5.0 μm or less, minor axis of 0.01 μm or more and 0.15 μm or less, and major axis of 0.10 μm or more and 4.0 μm or less are more preferred. The particle size distribution of the organic silver salt is preferably monodispersed. Monodisperse and the minor axis, the percentage of the value obtained by dividing the standard deviation of the length of each major axis by each minor axis, major axis is preferably 100% or less, more preferably 80% or less,
More preferably, it is 50% or less. The shape of the organic silver salt can be measured from a transmission electron microscope image of the organic silver salt dispersion. As another method of measuring the monodispersity, there is a method of determining the standard deviation of the volume-weighted average diameter of the organic silver salt, the percentage of the value divided by the volume-weighted average diameter (coefficient of variation) is preferably 100% or less, more Preferably 80% or less,
More preferably, it is 50% or less. As a measuring method, for example, the particle size (volume weighted average diameter) obtained by irradiating a laser beam to an organic silver salt dispersed in a liquid and obtaining an autocorrelation function with respect to a time change of fluctuation of the scattered light is obtained. Can be.

The organic silver salt which can be used in the present invention includes:
Preferably, desalting can be performed. The desalting method is not particularly limited, and a known method can be used. A known filtration method such as centrifugal filtration, suction filtration, ultrafiltration, or floc-forming water washing by a coagulation method can be preferably used.

In the present invention, in order to obtain an organic silver salt solid dispersion having a high S / N, a small particle size, and no aggregation, an organic silver salt which is an image forming medium and a photosensitive silver salt are substantially contained. It is preferable to use a dispersion method in which a water dispersion liquid which is not included in the liquid is converted into a high-speed stream and then the pressure is reduced.

After passing through these steps, the mixture is mixed with a photosensitive silver salt aqueous solution to prepare a photosensitive image forming medium coating solution. When a heat-developable image-forming material is prepared using such a coating solution, a haze is low, and a low-fogging and high-sensitivity heat-developable image-forming material can be obtained. On the other hand, when the photosensitive silver salt is coexistent when the light is converted into a high-pressure, high-speed flow and dispersed, the fog increases and the sensitivity is remarkably lowered. When an organic solvent is used instead of water as a dispersion medium, haze increases, fog increases, and sensitivity tends to decrease. on the other hand,
When a conversion method for converting a part of the organic silver salt in the dispersion liquid into the photosensitive silver salt is used instead of the method of mixing the aqueous solution of the photosensitive silver salt, the sensitivity is reduced.

In the above, the aqueous dispersion converted and dispersed under high pressure and high speed contains substantially no photosensitive silver salt, and its content is relative to that of the non-photosensitive organic silver salt. 0.
The content is 1 mol% or less, and the photosensitive silver salt is not positively added.

In the present invention, the solid dispersion apparatus and the technique used for carrying out the dispersion method as described above are described in, for example, “Dispersion Rheology and Dispersion Technique” (Toshio Kajiuchi, Hiroki Usui, 1991, Shinzansha Publishing Co., Ltd., p357
-P403), "The 24th Progress of Chemical Engineering", edited by The Society of Chemical Engineers, Tokai Branch, 1990, Maki Shoten, p184-p185),
Although detailed in the dispersing method of the present invention, the aqueous dispersion containing at least an organic silver salt is pressurized by a high-pressure pump or the like and sent into a pipe, and then passed through a narrow slit provided in the pipe, Thereafter, the dispersion is finely dispersed by causing an abrupt pressure drop in the dispersion.

The high-pressure homogenizer to which the present invention relates is generally composed of (a) a "shear force" generated when the dispersoid passes through a narrow gap at a high pressure and a high speed, and (b) a dispersoid is supplied from a high pressure to a normal pressure. It is considered that the particles are dispersed into fine particles by a dispersing force such as “cavitation force” generated when the particles are released. As an example of this type of dispersing apparatus, a Gaulin homogenizer is mentioned in the past.In this apparatus, the liquid to be dispersed sent at a high pressure is converted into a high-speed flow through a narrow gap on a cylindrical surface, and the force is applied to the surrounding wall by the force. The particles collide and are emulsified and dispersed by the impact force. Working pressure is generally 10
0~600kg / cm ^2, the flow rate is in the range of a few M～30m / sec, be devised that the high flow rate portion was devised such increasing the number collisions in the saw-toothed in order to increase the dispersion efficiency I have. On the other hand, in recent years, apparatuses capable of dispersing at higher pressure and higher flow rate have been developed, and typical examples thereof include a microfluidizer (Microfluidex International Corporation) and a nanomizer (specialized machine). Industrial Co., Ltd.).

As a dispersing apparatus suitable for the present invention, a microfluidizer M-110S-EH manufactured by Microfluidics International Corporation is used.
(With G10Z interaction chamber), M-
110Y (with H10Z interaction chamber), M-140K (with G10Z interaction chamber), HC-5000 (L30Z or H23
With 0Z interaction chamber), HC-80
00 (with an E230Z or L30Z interaction chamber) and the like.

Using these devices, an aqueous dispersion containing at least an organic silver salt is pressurized by a high-pressure pump or the like and fed into a pipe, and then passed through a narrow slit provided in the pipe to obtain a desired pressure. Is applied, and thereafter, the pressure in the pipe is rapidly returned to the atmospheric pressure, for example, by causing a rapid pressure drop in the dispersion liquid, thereby making it possible to obtain an optimal organic silver salt dispersion for the present invention. .

In the dispersion of the organic silver salt of the present invention, the flow rate,
It is possible to disperse to the desired particle size by adjusting the pressure difference during pressure drop and the number of treatments.However, from the viewpoint of photographic characteristics and particle size, the flow rate is 200 m / sec to 600 m / sec, is preferably in the range pressure is 900~3000kg / cm ^2, flow rate 300
m / sec ～600M / sec, the pressure difference at the pressure drop 1500~3000kg / cm ²
More preferably, it is within the range. The number of times of the distributed processing can be selected as needed. Usually, 1 to 10 treatments are selected, but from the viewpoint of productivity, about 1 to 3 treatments are selected. It is not preferable to raise the temperature of such an aqueous dispersion under high pressure from the viewpoint of dispersibility and photographic characteristics.At a temperature higher than 90 ° C., the particle size tends to increase, and the fog tends to increase. is there. Therefore, in the present invention, the step before the conversion to the high pressure and high flow rate, the step after the pressure is reduced, or both of these steps include a cooling step, and the temperature of such water dispersion is reduced by the cooling step. It is preferably kept in the range of ~ 90 ° C,
More preferably, the temperature is maintained in the range of 5 to 80C, particularly preferably in the range of 5 to 65C. In particular, it is effective to provide the above cooling step at the time of high-pressure dispersion in the range of 1500 to 3000 kg / cm ² . The cooler, depending on its required heat exchange,
Double tube or double tube using static mixer,
A multi-tube heat exchanger, a coiled tube heat exchanger, and the like can be appropriately selected. Further, in order to increase the efficiency of heat exchange, it is sufficient to select a suitable one such as a pipe thickness, a wall thickness and a material in consideration of a working pressure. Refrigerant used for the cooler, from the amount of heat exchange,
It is possible to use well water at 20 ° C., cold water at 5 to 10 ° C. treated with a refrigerator, and if necessary, a refrigerant such as ethylene glycol / water at −30 ° C.

In the dispersion operation of the present invention, it is preferable to disperse the organic silver salt in the presence of an aqueous solvent-soluble dispersant (dispersion aid). Examples of the dispersing agent include polyacrylic acid, a copolymer of acrylic acid, a maleic acid copolymer, a maleic acid monoester copolymer, a synthetic anionic polymer such as an acrylomethylpropanesulfonic acid copolymer, and carboxymethyl. Starch, semi-synthetic anionic polymers such as carboxymethyl cellulose, alginic acid, anionic polymers such as pectic acid, the compounds described in JP-A-7-350753, or known anionic, nonionic, cationic surfactants and other polyvinyl Known polymers such as alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxypropylcellulose and hydroxypropylmethylcellulose, or naturally occurring polymer compounds such as gelatin can be appropriately selected and used. Le compounds, particularly preferred water-soluble cellulose derivatives.

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

In addition to the mechanical dispersion, the particles may be coarsely dispersed in a solvent by controlling the pH, and then the pH may be changed in the presence of a dispersing aid to form fine particles. At this time, an organic solvent may be used as a solvent used for the coarse dispersion, and the organic solvent is usually removed after the completion of the fine particle formation.

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

[0122] The organic silver salt of the present invention can be used in a desired amount, preferably 0.1-5 g / m ² of silver per image forming material 1 m ^2, more preferably from 1 to 3 g / m ^2.

The heat-developable image forming material of the present invention preferably contains a reducing agent for an organic silver salt. A reducing agent for an organic silver salt is any substance that reduces silver ions to metallic silver,
Preferably, it may be an organic substance. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful, but hindered phenol reducing agents are preferred.
The reducing agent is used in an amount of 5 to 1 mol of silver on the surface having the image forming layer.
It is preferably contained at 50 mol%, more preferably at 10 to 40 mol%. The layer to which the reducing agent is added may be any layer on the side having the image forming layer. When it is added to a layer other than the image forming layer, it is preferable to use a relatively large amount of 10 to 50 mol% with respect to 1 mol of silver. Further, the reducing agent may be a so-called precursor which is derivatized so as to have a function effectively only during development.

In photothermographic materials utilizing organic silver salts, a wide range of reducing agents are disclosed in JP-A-46-6074 and JP-A-47-1238.
47-33621, 49-46427, 49-115540, 50-14
No. 334, No. 50-36110, No. 50-147711, No. 51-32632,
No. 51-1023721, No. 51-32324, No. 51-51933, No. 52-8
4727, 55-108654, 56-146133, 57-82828
No. 57-82829, JP-A-6-3793, U.S. Pat.
No. 86, No. 3,679,426, No. 3,751,252, No. 3,751,255
Nos. 3,761,270, 3,782,949, 3,839,048,
3,928,686, 5,464,738, German patent 2321328,
It is disclosed in European Patent No. 692732 and the like. For example, phenylamide oxime, 2-thienylamide oxime and
Amide oximes such as p-phenoxyphenylamide oxime; azines such as 4-hydroxy-3,5-dimethoxybenzaldehyde azine; combinations of 2,2′-bis (hydroxymethyl) propionyl-β-phenylhydrazine with ascorbic acid A combination of such an aliphatic carboxylic acid aryl hydrazide and ascorbic acid; a combination of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine (eg, hydroquinone and bis (ethoxyethyl) hydroxylamine, piperidinohexose reductone Or a combination of formyl-4-methylphenylhydrazine, etc.); phenylhydroxamic acid, p
Hydroxamic acids such as -hydroxyphenylhydroxamic acid and β-alinine hydroxamic acid; combinations of azines with sulfonamidophenols (eg, phenothiazine and 2,6-dichloro-4-benzenesulfonamidophenol); ethyl-α-cyano Α-cyanophenylacetic acid derivatives such as 2-methylphenylacetate and ethyl-α-cyanophenylacetate; 2,2′-dihydroxy-1,1′-binaphthyl, 6,6′-dibromo-2,2′-dihydroxy Bis-β-naphthol as exemplified by -1,1′-binaphthyl and bis (2-hydroxy-1-naphthyl) methane; bis-β-naphthol and 1,3-dihydroxybenzene derivatives (eg, 2,4
-Dihydroxybenzophenone or 2 ', 4'-dihydroxyacetophenone); 3-methyl-1-phenyl
5-pyrazolone, such as -5-pyrazolone; reductones as exemplified by dimethylaminohexose reductone, anhydrodihydroaminohexose reductone and anhydrodihydropiperidone hexose reductone;
Sulfonamidophenol reducing agents such as 2,6-dichloro-4-benzenesulfonamidophenol and p-benzenesulfonamidophenol; 2-phenylindane-1,3-
A dione or the like; a chroman such as 2,2-dimethyl-7-t-butyl-6-hydroxychroman; a 1,4-dihydropyridine such as 2,6-dimethoxy-3,5-dicarboethoxy-1,4-dihydropyridine; Bisphenols (e.g., bis (2-hydroxy
-3-t-butyl-5-methylphenyl) methane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-ethylidene
-Bis (2-t-butyl-6-methylphenol), 1,1, -bis (2
-Hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane and the like); ascorbic acid derivatives (for example, palmitic acid 1 And aldehydes and ketones such as benzyl and biacetyl; 3-pyrazolidones and certain indan-1,3-diones; chromanols (such as tocopherols). Particularly preferred reducing agents are bisphenol and chromanol.

The reducing agent of the present invention may be added by any method such as a solution, a powder, and a solid fine particle dispersion. The dispersion of the solid fine particles is carried out by a known means for making fine (for example, a ball mill, a vibration ball mill, a sand mill, a colloid mill, a jet mill, a roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

When an additive known as a "toning agent" for improving an image is contained, the optical density may be increased. Toning agents may also be advantageous in forming black silver images. The toning agent is preferably contained in an amount of 0.1 to 50% (mole) per mole of silver on the surface having the image forming layer, and more preferably 0.5 to 20% (mole).
Further, the color tone agent may be a so-called precursor which is derivatized so as to have a function effectively only during development.

In a photothermographic material using an organic silver salt, a wide range of color toning agents are disclosed in JP-A-46-6077 and JP-A-47-10282.
Nos. 49-5019, 49-5020, 49-91215, 49-9
No. 1215, No. 50-2524, No. 50-32927, No. 50-67132,
No. 50-67641, No. 50-114217, No. 51-3223, No. 51-279
No. 23, No. 52-14788, No. 52-99813, No. 53-1020, No. 5
3-76020, 54-156524, 54-156525, 61-1836
No. 42, JP-A-4-56848, JP-B-49-10727, 54-2033
No. 3, U.S. Pat.Nos. 3,080,254, 3,446,648, 3,782,9
No. 41, No. 4,123,282, No. 4,510,236, British Patent 138079
No. 5, Belgian Patent No. 841910 and the like. Examples of toning agents are phthalimide and N-hydroxyphthalimide; succinimide, pyrazolin-5-one and quinazolinone, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione Cyclic imides such as; naphthalimides (eg, N
-Hydroxy-1,8-naphthalimide); cobalt complexes (eg, cobalt hexamine trifluoroacetate); 3-
Mercapto-1,2,4-triazole, 2,4-dimercaptopyrimidine, 3-mercapto-4,5-diphenyl-1,2,4-triazole and 2,5-dimercapto-1,3,4-thiadiazole Illustrative mercaptans; N- (aminomethyl) aryldicarboximides, such as (N, N-dimethylaminomethyl) phthalimide and N, N- (dimethylaminomethyl)-
Naphthalene-2,3-dicarboximide); and blocked pyrazoles, isothiuronium derivatives and certain photobleaching agents (eg, N, N′-hexamethylenebis (1-carbamoyl-3,5-dimethylpyrazole), 1 , 8- (3,6-diazaoctane) bis (isothiuronium trifluoroacetate) and 2-tribromomethylsulfonyl)-(benzothiazole)); and 3-ethyl-5 [(3-ethyl-2-benzothia) Zolinylidene) -1-methylethylidene] -2-thio-2,4-oxazolidinedione; phthalazinone, phthalazinone derivative or metal salt, or 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7- Derivatives such as dimethoxyphthalazinone and 2,3-dihydro-1,4-phthalazinedione; phthalazinone and phthalic acid derivatives (for example, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic acid) Combination of anhydride such as phthalic acid); phthalazine, phthalazine derivatives (e.g., 4- (1-naphthyl) phthalazine, 6
-Chlorophthalazine, 5,7-dimethoxyphthalazine, 6-iso
Derivatives such as -butylphthalazine, 6-tert-butylphthalazine, 5,7-dimethylphthalazine, and 2,3-dihydrophthalazine) or metal salts; phthalazine and its derivatives and phthalic acid derivatives (for example, phthalic acid) Acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride, etc.); quinazolinedione, benzoxazine or naphthooxazine derivatives; Rhodium complexes that also function as sources of halide ions, such as ammonium hexachlororhodate (III), rhodium bromide, rhodium nitrate and potassium hexachlororhodate (III); inorganic peroxides and persulfates, such as
Ammonium disulfide and hydrogen peroxide; 1,3-benzoxazine-2,4-dione, 8-methyl-1,3-benzoxazine-2,4-dione and 6-nitro-1,3-benzoxazine Benzoxazine-2,4-dione such as -2,4-dione; pyrimidine and asymmetric triazines (eg, 2,4-dihydroxypyrimidine, 2-hydroxy-4-aminopyrimidine, etc.), azauracil, and tetraazapentane Ren derivatives (e.g., 3,6-dimercapto-1,4-diphenyl-1H, 4H-
2,3a, 5,6a-tetraazapentalene and 1,4-di (o-chlorophenyl) -3,6-dimercapto-1H, 4H-2,3a, 5,6a-tetraazapentalene) is there.

The color-toning agent of the present invention may be added by any method such as a solution, a powder and a dispersion of solid fine particles. The dispersion of the solid fine particles is carried out by a known means for making fine (for example, a ball mill, a vibration ball mill, a sand mill, a colloid mill, a jet mill, a roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

As the binder for the image forming layer (photosensitive layer, emulsion layer) in the present invention, well-known natural or synthetic resins such as gelatin, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, cellulose acetate, polyolefin, Any material can be selected from polyester, polystyrene, polyacrylonitrile, polycarbonate, and the like. Of course, copolymers and terpolymers are also included. Preferred polymers are polyvinyl butyral, butyl ethyl cellulose, methacrylate copolymer, maleic anhydride copolymer, polystyrene and butadiene-
It is a styrene copolymer. If necessary, two or more of these polymers can be used in combination. Such a polymer is used in an amount sufficient to hold the components therein. That is, it is used in a range effective to function as a binder. The effective range can be appropriately determined by those skilled in the art. As a guide when at least the organic silver salt is retained, the ratio of the binder to the organic silver salt is preferably 15: 1 to 1: 2, particularly preferably 8: 1 to 1: 1.

At least one of the image forming layers of the present invention contains at least 50% of the total binder by a polymer latex described below.
It is preferable that the image forming layer contains at least wt%. (Hereinafter, this image forming layer is referred to as "the image forming layer of the present invention", and the polymer latex used for the binder is referred to as "the polymer latex of the present invention.") The polymer latex is not limited to the image forming layer, but may be a protective layer or a back layer. May be used for
In particular, when the photothermographic material of the present invention is used for printing in which dimensional change is a problem, it is necessary to use a polymer latex for the protective layer and the back layer. However, the "polymer latex" referred to here is a water-insoluble hydrophobic polymer dispersed as fine particles in a water-soluble dispersion medium. The dispersion state is such that the polymer is emulsified in a dispersion medium, emulsion-polymerized, micelle-dispersed, or partially dispersed in polymer molecules and molecular chains themselves are molecularly dispersed. Any of them may be used. For the polymer latex of the present invention, `` Synthetic resin emulsion (Hiroshi Okuda, edited by Hiroshi Inagaki, published by the Society of Polymer Publishing (1978)) '', `` Application of synthetic latex (Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, edited by Keiji Kasahara, Published by Polymer Publishing Association (1
993)) "," Synthesis of Synthetic Latex (Souichi Muroi, published by Kobunshi Kankokai (1970)) "and the like. The average particle size of the dispersed particles is preferably in the range of 1 to 50,000 nm, more preferably about 5 to 1000 nm. There is no particular limitation on the particle size distribution of the dispersed particles, and those having a wide particle size distribution or those having a monodispersed particle size distribution may be used.

As the polymer latex of the present invention, other than a polymer latex having a normal uniform structure, a so-called core / polymer latex may be used.
Shell type latex may be used. In this case, it may be preferable to change the glass transition temperature of the core and the shell.

The glass transition temperature (Tg) of the polymer latex used in the binder of the present invention differs between the protective layer, the back layer and the image forming layer. For the image-forming layer, 40
° C or lower, and more preferably -30 to 40 ° C. When used for the protective layer or the back layer, a glass transition temperature of 25 to 70 ° C. is preferable for contacting various devices.

The minimum film forming temperature (MFT) of the polymer latex of the present invention is preferably -30 ° C to 90 ° C, more preferably about 0 ° C to 70 ° C. A film-forming auxiliary may be added to control the minimum film-forming temperature. The film-forming aid is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of the polymer latex, also called a plasticizer, and is described in, for example, `` Synthesis of Synthetic Latex (Souichi Muroi, published by Polymer Publishing Association (1970) )"It is described in.

Examples of the polymer used in the polymer latex of the present invention include acrylic resins, vinyl acetate resins, polyester resins, polyurethane resins, rubber resins, vinyl chloride resins, vinylidene chloride resins, polyolefin resins, and copolymers thereof. There is. The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of the polymer is preferably from 5000 to 100000, more preferably from about 10,000 to 100,000 in number average molecular weight. If the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and if it is too large, the film-forming property is poor, which is not preferable.

Specific examples of the polymer latex used as a binder in the image forming layer of the heat-developable image forming material of the present invention include the following. Latex of methyl methacrylate / ethyl acrylate / methacrylic acid copolymer, latex of methyl methacrylate / 2 ethylhexyl acrylate / styrene / acrylic acid copolymer, latex of styrene / butadiene / acrylic acid copolymer, latex of styrene / butadiene / divinylbenzene / methacrylic acid copolymer, Latex of methyl methacrylate / vinyl chloride / acrylic acid copolymer, latex of vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer and the like. Such polymers are also commercially available, and the following polymers can be used. For example, as examples of acrylic resin, Sebian A-4635,46583,4601 (all manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811,814,821,820,8
Polyester resins include FINETEX ES650, 611, 675, and 850 (all manufactured by Dainippon Ink and Chemicals), WD-size, WMS (all manufactured by Eastman Chemical) , HYDRAN AP1 as polyurethane resin
0, 20, 30, 40 (all manufactured by Dainippon Ink and Chemicals, Inc.)
LACSTAR 7310K, 3307B, 4700H, 713 as rubber resin
2C (Dai Nippon Ink Chemical Co., Ltd.), Nipol Lx416, 41
0, 438C, 2507, (Nippon Zeon Co., Ltd.) and other vinyl chloride resins such as G351 and G576 (Nippon Zeon Co., Ltd.)
L502, L513 (manufactured by Asahi Kasei Kogyo Co., Ltd.), Aron D7020, D504, D5071 (manufactured by Mitsui Toatsu Co., Ltd.) Mitsui Petrochemical Co., Ltd.). These polymers may be used alone or as a blend of two or more as necessary.

In the image forming layer of the present invention, the polymer latex is preferably used in an amount of 50% by weight or more of the total binder, and more preferably 70% by weight or more.

In the image forming layer of the present invention, gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose and the like may be added in an amount of 50% by weight or less, preferably 10% by weight or less of the whole binder, if necessary. May be added. The amount of these hydrophilic polymers added is 30% by weight of the total binder of the image forming layer.
Below, more preferably 15% by weight or less.

The image forming layer of the present invention is preferably prepared by applying an aqueous coating solution and then drying. However, the term "aqueous" as used herein means that 60% by weight or more of the solvent (dispersion medium) of the coating liquid is water. Components other than water in the coating solution are methyl alcohol, ethyl alcohol, isopropyl alcohol,
Water-miscible organic solvents such as methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate can be used. Specific examples of the solvent composition include the following in addition to water. Water / methanol = 90/1
0, water / methanol = 70/30, water / ethanol = 90/10,
Water / isopropanol = 90/10, water / dimethylformamide = 95/5, water / methanol / dimethylformamide = 8
0/15/5, water / methanol / dimethylformamide = 90
/ 5/5. (However, the numbers represent wt%.)

The total amount of the binder in the image forming layer of the present invention is 0.1.
The range is preferably ^{2 to} 30 g / m ² , more preferably 1 to 15 g / m ² . A crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added to the image forming layer of the invention.

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

As an example of spectral sensitization to red light, He-Ne
For a so-called red light source such as a laser, a red semiconductor laser or an LED, a compound of I-1 to I-38 described in JP-A-54-18726, and a compound of I-1 described in JP-A-6-75322. I-3
5 and the compounds I-1 to I- described in JP-A-7-287338.
34 compounds, dyes 1 to 20 described in JP-B-55-39818,
The compounds I-1 to I-37 described in JP-A-62-284343 and the compounds I-1 to I-34 described in JP-A-7-287338 are advantageously selected.

For a semiconductor laser light source in the wavelength region of 750 to 1400 nm, cyanine, merocyanine, styryl,
A variety of known dyes, including hemicyanine, oxonol, hemioxonol and xanthene dyes, can be spectrally sensitized favorably. Useful cyanine dyes are, for example, cyanine dyes having a basic nucleus, such as a thiazoline nucleus, an oxazoline nucleus, a pyrroline nucleus, a pyridine nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus and an imidazole nucleus. Preferred useful merocyanine dyes include, in addition to the above basic nuclei, acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus. Including. Among the above-mentioned cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective. For example, U.S. Pat.
3,719,495, 3,877,943, British Patent 1,466,201,
No. 1,469,117, No. 1,422,057, No. 3-10391, No. 6
-52387, JP-A-5-341432, JP-A-6-94781, JP-A-6-3011
The dye may be appropriately selected from known dyes as described in No. 41.

Particularly preferred as the structure of the dye used in the present invention is a cyanine dye having a thioether bond-containing substituent (for example, see JP-A-62-58239 and JP-A-3-13863).
No.8, No.3-138642, No.4-255840, No.5-72659, No.5-
No. 72661, No. 6-222491, No. 2-230506, No. 6-258757
No., 6-317868, 6-324425, Tokuyohei 7-500926,
Dyes described in U.S. Pat.
No. 141, dyes described in U.S. Patent No.
No. 52-80829, No. 54-61517, No. 59-214846, No. 60-67
No. 50, 63-159841, JP-A-6-35109, 6-59381
No., 77-146537, 77-146537, Tokuyohei 55-50111,
Dyes described in British Patent 1,467,638 and US Patent 5,281,515).

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

These sensitizing dyes may be used alone.
Two or more kinds may be used in combination. Combinations of sensitizing dyes are often used, especially for supersensitization. In addition to the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization and substances exhibiting supersensitization are
Research Disclosure Volume 176, 17643 (Issued December 1978) No. 23
Section IV on page IV, or JP-B-49-25500, 43-43933,
These are described in JP-A-59-19032 and JP-A-59-192242.

The sensitizing dyes can be added to the silver halide emulsion by dispersing them directly in the emulsion or by adding water, methanol, ethanol, propanol, acetone, methylcellosolve, 2,2, 3,3-tetrafluoropropanol, 2,2,2-trifluoroethanol, 3-methoxy
It may be added to the emulsion by dissolving it in a solvent such as 1-propanol, 3-methoxy-1-butanol, 1-methoxy-2-propanol, N, N-dimethylformamide, alone or in a mixed solvent.

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

The sensitizing dye used in the present invention may be added to the silver halide emulsion of the present invention at any stage of the emulsion preparation which has been found to be useful. For example, U.S. Patents 2,735,766 and 3,628,960,
No. 4,183,756, No. 4,225,666, JP-A-58-184142,
As disclosed in the specification of JP-A-60-196749 and the like, the timing before silver halide grain forming step and / or desalting, during and / or after desalting and before the start of chemical ripening. As disclosed in the specification such as JP-A-58-113920, any time immediately before chemical ripening or during the process, after chemical ripening, and before coating the emulsion before coating It may be added at the time and in the process.
Also, as disclosed in the specification of U.S. Pat. No. 4,225,666, JP-A-58-7629, etc., the same compound may be used alone or in combination with a compound having a different structure, for example, during the particle forming step. The compound may be added separately during the ripening step or after the completion of the chemical ripening, or may be added separately before or during the chemical ripening or after the completion of the chemical ripening. May be added.

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

In the present invention, the silver halide emulsion or /
And organic silver salts can be further protected against the formation of additional fog by antifoggants, stabilizers and stabilizer precursors, and stabilized against reduced sensitivity during storage in inventory. Suitable antifoggants, stabilizers and stabilizer precursors that can be used alone or in combination are the thiazonium salts described in U.S. Pat.Nos. 2,131,038 and 2,694,716, U.S. Pat. Azaindene, U.S. Pat.
8,663 mercury salt, U.S. Pat.No. 3,287,135 urazole, U.S. Pat.
Nitrone, nitroindazole, U.S. Patent No. 2,839,405
No. 3,220,839, thiuronium salts, and U.S. Pat.Nos. 2,566,263 and 2,597,915, palladium, platinum and gold salts, U.S. Pat.Nos. 4,108,665 and 4,442,202 No. 4,128,557
Nos. 4,137,079 and 4,138,365 and 4,
No. 4,59,350 and U.S. Pat.
And the phosphorus compounds described in 1,985.

The antifoggant preferably used in the present invention is an organic halide, for example, as described in JP-A-50-119624.
No., No. 50-120328, No. 51-121332, No. 54-58022, No.
56-70543, 56-99335, 59-90842, 61-12964
No. 2, 62-129845, JP-A-6-208191, 7-5621,
Nos. 7-2781, 8-15809, U.S. Pat.No. 5,340,712,
Compounds such as those disclosed in US Pat. Nos. 5,369,000 and 5,464,737 can be mentioned.

The antifoggant of the present invention may be added by any method such as a solution, a powder and a dispersion of solid fine particles. The dispersion of the solid fine particles is carried out by a known means for making fine (for example, a ball mill, a vibration ball mill, a sand mill, a colloid mill, a jet mill, a roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

Although not required to practice the present invention,
It may be advantageous to add a mercury (II) salt as an antifoggant to the emulsion layer (photosensitive layer). Preferred mercury (II) salts for this purpose are mercury acetate and mercury bromide. The amount of mercury used in the present invention is preferably 1 nmol to 1 mmol, more preferably 10 nmol, per 1 mol of coated silver.
The range is from mol to 100 μm mol.

The heat-developable image forming material of the present invention may contain benzoic acids for the purpose of increasing the sensitivity and preventing fog. The benzoic acids of the present invention may be any benzoic acid derivative, but examples of preferred structures include those described in U.S. Pat.
No. 939, No. 4,152,160, Japanese Patent Application No. 8-151242, No. 8-151241
And the compounds described in JP-A-8-98051 and the like. The benzoic acid of the present invention may be added to any part of the image forming material. preferable. The benzoic acid of the present invention may be added in any step of coating solution preparation, and when it is added to an organic silver salt-containing layer, any step from the preparation of organic silver salt to the preparation of coating solution may be used. It is preferable after salt preparation and immediately before application. The benzoic acid of the present invention may be added by any method such as powder, solution, and fine particle dispersion. Further, it may be added as a solution mixed with other additives such as a sensitizing dye, a reducing agent and a color tone agent. The benzoic acid of the present invention may be added in any amount.
It is preferably 1 μmol or more and 2 mol or less, more preferably 1 mmol or more and 0.5 mol or less per mol.

In the present invention, at least one compound of a heteroaromatic mercapto compound and a heteroaromatic disulfide compound is added, and preferably, these compounds are added as a supersensitizer.

The supersensitizer is a compound having a function of increasing the efficiency of a sensitizing dye used for silver halide. The supersensitizer of the present invention is mainly composed of a He-Ne laser, a red semiconductor laser, It is used for a red light source such as an LED and a semiconductor laser light source in a wavelength range of 750 to 1400 nm. With these light sources, the sensitizing efficiency of the sensitizing dye alone is insufficient, and it is necessary to use a supersensitizer.

These compounds are preferably represented by Ar-SM and Ar-SS-Ar. Wherein M is a hydrogen atom or an alkali metal atom, and Ar is one or more nitrogen, sulfur,
An aromatic ring group having oxygen, selenium or tellurium atom or a condensed aromatic ring group. Preferably, the heteroaromatic ring in these groups is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, Triazine, pyrimidine, pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring includes, for example, halogens (e.g., Br and Cl), hydroxy, amino, carboxy,
Alkyl (e.g. one or more carbon atoms, preferably 1-4
Having one carbon atom), alkoxy (eg, having one or more carbon atoms, preferably 1-4 carbon atoms) and aryl (optionally having substituents)
And a substituent selected from the group consisting of:
As mercapto-substituted heteroaromatic compounds, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5
-Methylbenzimidazole, 2-mercapto-5-methylbenzoxazole, 2-mercapto-5-methylbenzothiazole, 6-ethoxy-2-mercaptobenzothiazole,
2,2'-dithiobis-benzothiazole, 3-mercapto-1,
2,4-triazole, 4,5-diphenyl-2-imidazole thiol, 2-mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2-mercaptoquinoline, 8-
Mercaptopurine, 2-mercapto-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,
5,6-tetrachloro-4-pyridinethiol, 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate, 2-
Amino-5-mercapto-1,3,4-thiadiazole, 3-amino
-5-Mercapto-1,2,4-triazole, 4-hydrokilos-2-
Mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-
Diamino-2-mercaptopyrimidine, 2-mercapto-4-methylpyrimidine hydrochloride, 3-mercapto-5-phenyl-1,2,4-triazole, 1-phenyl-5-mercaptotetrazole, 3- (5-mercaptotetrazole ) -Sodium benzenesulfonate, N-methyl-N '-[3- (5-mercaptotetrazolyl) phenyl] urea, 2-mercapto-4-phenyloxazole, and the like, but the invention is not limited thereto. .

The addition amount of these mercapto compounds or disulfide compounds is in the range of 0.001 to 1 mol per mol of silver, preferably 0.003 to 1 mol per mol of silver.
The amount is 0.1 mol. The addition layer may be a layer on the image forming layer side, but is preferably an image forming layer (more preferably a photosensitive layer).

In the image forming layer (preferably the photosensitive layer) in the present invention, a polyhydric alcohol (for example, glycerin and diol of the type described in US Pat. No. 2,960,404) as a plasticizer and a lubricant, and US Pat. Fatty acids or esters described in 2,588,765 and 3,121,060,
For example, a silicone resin described in British Patent No. 955,061 can be used.

The heat-developable image-forming material of the present invention may have a surface protective layer for the purpose of preventing adhesion of the image-forming layer.

The binder for the surface protective layer of the present invention may be any polymer, but preferably contains a polymer having a carboxylic acid residue in an amount of 100 mg / m ^{2 to} 5 g / m ² . Examples of the polymer having a carboxyl residue include natural polymers (gelatin, alginic acid, etc.), modified natural polymers (carboxymethylcellulose, phthalated gelatin, etc.), synthetic polymers (polymethacrylate, polyacrylate, polyalkyl methacrylate / acrylate). Copolymer, polystyrene / polymethacrylate copolymer) and the like. The content of carboxy residues in the polymer is preferably from 10 mmol to 1.4 mol per 100 g of the polymer. Further, the carboxylic acid residue may form a salt with an alkali metal ion, an alkaline earth metal ion, an organic cation, or the like.

As the surface protective layer of the present invention, any anti-adhesion material may be used. Examples of anti-adhesion materials include waxes, silica particles, styrene-containing elastomeric block copolymers (e.g., styrene-butadiene-
Styrene, styrene-isoprene-styrene), cellulose acetate, cellulose acetate butyrate, cellulose propionate, and mixtures thereof. Further, a crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added to the surface protective layer.

In the image forming layer or the protective layer of the image forming layer in the invention, US Pat. Nos. 3,253,921 and 2,27
Light absorbing substances and filter dyes as described in 4,782, 2,527,583 and 2,956,879 can be used. Also, for example, U.S. Pat.
The dye can be mordanted as described in US Pat. As the amount of filter dye used, the absorbance at the exposure wavelength is 0.
1-3 are preferable, and 0.2-1.5 are particularly preferable.

Various dyes and pigments can be used in the photosensitive layer of the present invention from the viewpoint of improving color tone and preventing irradiation. Dyes and pigments used in the photosensitive layer of the present invention may be any, for example, there are pigments and dyes described in the color index, specifically pyrazoloazole dye, anthraquinone dye, azo dye, azomethine dye,
Oxonol dyes, carbocyanine dyes, styryl dyes, triphenylmethane dyes, indoaniline dyes, indophenol dyes, organic pigments including phthalocyanine, and inorganic pigments. Preferred dyes used in the present invention include anthraquinone dyes (e.g., compounds 1 to 9 described in JP-A-5-341441, compounds 3-6 to 18 and 3-23 to 38 described in JP-A-5-165147), azomethine Dyes (e.g., compounds 17 to 47 described in JP-A-5-341441) and indoaniline dyes (e.g., compound 11 described in JP-A-5-289227).
To 19, compound 47 described in JP-A-5-341441, JP-A-5-1651
No. 47, compounds 2-10 to 11) and azo dyes (JP-A No.
Compounds 10 to 16) described in 5-341441 are exemplified. As a method for adding these dyes, any method such as a solution, an emulsion, a solid fine particle dispersion, and a state in which the dye is mordanted with a polymer mordant may be used. The amount of these compounds is determined by absorption of the purpose, generally the image forming material 1 m ² per 1μ
It is preferable to use in the range of g or more and 1 g or less.

The photosensitive heat-developable image-forming material of the present invention has at least one photosensitive layer (preferably an image-forming layer) containing a silver halide emulsion on one side of a support.
It is preferably a so-called single-sided image forming material having a back layer on the other side.

In the present invention, the back layer preferably has a maximum absorption in a desired range of about 0.3 or more and 2.0 or less.
750-360nm if the desired range is 750-1400nm
Is preferably 0.005 or more and less than 0.5, more preferably an antihalation layer having an optical density of 0.001 or more and less than 0.3. When the desired range is 750 nm or less, the halation is such that the maximum absorption in the desired range before image formation is 0.3 or more and 2.0 or less, and the optical density at 360-750 nm after image formation is 0.005 or more and less than 0.3. Preferably, it is a prevention layer. The method for lowering the optical density after image formation to the above range is not particularly limited. For example, as described in Belgian Patent No. 733,706, a method in which the density of a dye is reduced by decolorization by heating, And a method of decreasing the density by decoloring by light irradiation described in JP-A-17833.

When antihalation dyes are used in the present invention, such dyes have the desired absorption in the desired range,
Any compound may be used as long as it has a sufficiently low absorption in the visible region after the treatment and a preferable absorbance spectrum of the back layer is obtained. For example, the following are disclosed, but the present invention is not limited thereto. As a single dye, JP-A-59-56458, JP-A-2-216140,
No. 7-13295, No. 7-11432, U.S. Pat.No.5,380,635, JP-A-2-688539, page 13, lower left column, line 1 to line 14,
The lower left column of the page, line 9, from the lower left column of page 14 of JP-A-3-24539
There are compounds described in the lower right column of page 16, and as dyes which can be decolorized by treatment, JP-A Nos. 52-139136, 53-132334, 56-50148.
No. 0, No. 57-16060, No. 57-68831, No. 57-101835, No.
No. 59-182436, JP-A-7-36145, 7-199409
No. 48-33692, No. 50-16648, Japanese Patent Publication No. 2-41734, U.S. Pat.Nos. 4,088,497, 4,283,487, 4,548,896, 5,1
There is 87,049.

In the present invention, suitable binders for the back layer are transparent or translucent, generally colorless, and include natural polymer synthetic resins, polymers and copolymers, and other film-forming media such as: gelatin, acacia, poly (vinyl). (Alcohol), hydroxyethylcellulose, cellulose acetate, cellulose acetate butyrate, poly (vinylpyrrolidone), casein, starch, poly (acrylic acid), poly (methylmethacrylic acid), poly (vinyl chloride), poly (methacrylic acid), copoly (Styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinylacetal) s (e.g., poly (vinylformal) and poly (vinylformal))
(Vinyl butyral)), poly (ester) s, poly (urethanes), phenoxy resin, poly (vinylidene chloride), poly (vinylidene chloride)
(Epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, and poly (amides). The binder may be coated from water or an organic solvent or emulsion.

In the present invention, a matting agent may be added to the surface protective layer of the photosensitive emulsion layer and / or the back layer or the surface protective layer of the back layer to improve the transportability of the single-sided image forming material. The matting agent is generally fine particles of an organic or inorganic compound insoluble in water. Any matting agent can be used, for example, U.S. Pat.
2,701,245, 2,322,037, 3,262,782, 3,53
No. 9,344, 3,767,448, etc., organic matting agents described in each specification, 1,260,772, 2,192,241, 3,257,206
No. 3,370,951, 3,523,022, 3,769,020, etc., inorganic matting agents well-known in the art such as inorganic matting agents described in the respective specifications can be used. For example, specifically, examples of organic compounds that can be used as a matting agent include, as examples of water-dispersible vinyl polymers, polymethyl acrylate, polymethyl methacrylate, polyacrylonitrile, acrylonitrile-α-methylstyrene copolymer,
Polystyrene, styrene-divinylbenzene copolymer,
Examples of cellulose derivatives such as polyvinyl acetate, polyethylene carbonate, and polytetrafluoroethylene, such as methyl cellulose, cellulose acetate, and cellulose acetate propionate; examples of starch derivatives such as carboxy starch, carboxynitrophenyl starch, and urea-formaldehyde-starch reactant For example, gelatin hardened with a known hardener and hardened gelatin obtained by coacervate hardening to form fine capsule hollow particles can be preferably used. As examples of the inorganic compound, silicon dioxide, titanium dioxide, magnesium dioxide, aluminum oxide, barium sulfate, calcium carbonate, silver chloride desensitized by a known method, silver bromide, glass, and diatomaceous earth can be preferably used. The above matting agents can be used by mixing different types of substances as necessary.
The size and shape of the matting agent are not particularly limited, and those having an arbitrary particle size can be used. In carrying out the present invention
It is preferable to use one having a particle size of 0.1 μm to 30 μm. Further, the particle size distribution of the matting agent may be narrow or wide. On the other hand, since the matting agent greatly affects the haze of the coating film and the surface gloss, the particle size, shape, and particle size distribution can be changed as necessary during the preparation of the matting agent or by mixing a plurality of matting agents. preferable.

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

In the present invention, the matting agent is preferably contained in the outermost surface layer of the image forming material, a layer functioning as the outermost surface layer, or a layer close to the outer surface, and a layer functioning as a so-called protective layer. Is preferably contained. The degree of matting of the emulsion surface protective layer may be any value as long as stardust failure does not occur, but the Beck smoothness is preferably 500 seconds or more and 10,000 seconds or less, particularly preferably 500 seconds or more and 2,000 seconds or less.

The photothermographic emulsion of the present invention comprises one or more layers on a support. One layer must contain additional optional materials such as organic silver salts, silver halides, developers and binders, and toning agents, coating aids and other auxiliaries. The two-layer configuration is
One must contain the organic silver salt and silver halide in one emulsion layer (usually the layer adjacent to the support) and some other components in the second or both layers. However, a two-layer construction comprising a single emulsion layer containing all components and a protective topcoat is also contemplated. The construction of a multicolor photothermographic material may include a combination of these two layers for each color, and may include all components in a single layer as described in U.S. Pat.No. 4,708,928. Is also good. In the case of a multi-dye, multi-color photosensitive heat-developable photographic material, each emulsion layer is generally, as described in U.S. Pat.
By using a functional or non-functional barrier layer between each emulsion layer (photosensitive layer), it is kept distinct from each other.

US Pat. Nos. 4,460,681 and 4,374,9
Backside resistive heating layer as shown in No. 21
stive heating layer) can also be used in a photosensitive heat developed photographic image system.

A hardening agent may be used in each of the layers such as the image forming layer (preferably the photosensitive layer), the protective layer and the back layer according to the invention. Examples of the hardener include U.S. Pat.No.4,281,060, polyisocyanates described in JP-A-6-208193, epoxy compounds described in U.S. Pat.No.4,791,042, JP-A-62-89048. For example, vinyl sulfone compounds described in US Pat.

In the present invention, a surfactant may be used for the purpose of improving coating properties and charging. As the surfactant, any surfactant such as nonionic, anionic, cationic, and fluorine can be used as appropriate. Specifically,
No. 62-170950, Fluoropolymer surfactants described in U.S. Pat.No.5,380,644, JP-A-60-244945, JP-A-63-18
8135 No. fluorinated surfactants described in U.S. Pat.
Examples thereof include polysiloxane surfactants described in JP-A-5,965 and the like, polyalkylene oxides and anionic surfactants described in JP-A-6-301140 and the like.

The photographic emulsion for thermal development in the present invention can be generally coated on various supports. Typical supports include polyester films, primed polyester films, poly (ethylene terephthalate) films, polyethylene naphthalate films, cellulose nitrate films, cellulose ester films, poly (vinyl acetal) films, polycarbonate films and related or resinous Materials, as well as glass,
Including paper, metal, etc. Flexible substrates, in particular coated with partially acetylated or baryta and / or α-olefin polymers, especially polymers of C 2-10 α-olefins such as polyethylene, polypropylene, ethylene-butene copolymers A coated paper support is typically used. Such a support may be transparent or opaque, but is preferably transparent. Among them, biaxially stretched polyethylene terephthalate (PET) of about 75 to 200 μm is particularly preferred.

On the other hand, when a plastic film is passed through a heat developing machine at a temperature of 80 ° C. or higher, the dimensions of the film generally expand and contract. If the processed material is used for printing plate making,
This expansion and contraction is a serious problem when performing precision multicolor printing.
Therefore, in the present invention, it is preferable to use a film having a small dimensional change, which is designed to reduce internal strain remaining in the film at the time of biaxial stretching and eliminate thermal shrinkage distortion generated during thermal development. For example, polyethylene terephthalate, which is heat-treated at 100 to 210 ° C. before coating the photographic emulsion for thermal development, is preferably used. Those having a high glass transition point are also preferable, and polyether ethyl ketone, polystyrene, polysulfone, polyethersulfone,
Polyarylate, polycarbonate and the like can be used.

The heat-developable image-forming material of the present invention may be used, for example, as described in US Pat. Nos. 2,861,056 and 3,206,312 for the purpose of preventing static charge, for example, soluble salts (eg, chlorides and nitrates), deposited metal layers, and the like. An ionic polymer or an insoluble inorganic salt as described in U.S. Pat.No. 3,428,451,
It may have a layer containing tin oxide fine particles described in JP-A-60-252349 and JP-A-57-104931.

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

The photothermographic emulsions of the present invention can be coated by various coating operations including dip coating, air knife coating, flow coating or extrusion coating using a hopper of the type described in US Pat. No. 2,681,294. If desired, two or more layers can be coated simultaneously by the methods described in US Pat. No. 2,761,791 and British Patent No. 837,095.

Additional layers in the heat-developable image-forming material of the present invention, such as a dye-receiving layer for receiving a moving dye image, an opaque layer if reflective printing is desired, a protective topcoat layer and photothermographic techniques And a known primer layer. It is preferable that the image forming material of the present invention can form an image with only one material, and it is preferable that a functional layer necessary for image formation such as an image receiving layer does not become another material.

The heat-developable image-forming material of the present invention may be developed by any method, but is usually developed by raising the temperature of the image-wise exposed imagewise material. As a preferred embodiment of the heat developing machine used, as a type in which the heat-developable image forming material is brought into contact with a heat source such as a heat roller or a heat drum, Japanese Patent Publication No. 5-56499, Patent Publication No. 684453, JP-A-9-292695, JP-A-9-297385 and International Patent WO
No. 95/30934, as a non-contact type, JP-A-7-13294, International Patent WO 97/28489, and 97/2848
Nos. 8 and 97/28487. A particularly preferred embodiment is a non-contact type thermal developing machine. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 140 ° C. The development time is preferably from 1 to 180 seconds, more preferably from 10 to 90 seconds.

As a method for preventing the processing unevenness due to the dimensional change during the heat development of the heat-developable image-forming material of the present invention,
A method in which an image is not formed at a temperature of 80 ° C. or more and less than 115 ° C. (preferably 113 ° C. or less), heated for 5 seconds or more, and then thermally developed at 110 ° C. or more (preferably 130 ° C. or less) to form an image ( A so-called multi-stage heating method) is effective.

The photosensitive heat-developable image forming material of the present invention may be exposed by any method, but a laser beam is preferred as an exposure light source. As the laser beam according to the present invention, a gas laser, a YAG laser, a dye laser, a semiconductor laser and the like are preferable. Further, a semiconductor laser and a second harmonic generation element can be used.

The photosensitive heat-developable image-forming material of the present invention has a low haze at the time of exposure and tends to cause interference fringes.
Examples of this interference fringe prevention technology include a technology in which a laser beam is obliquely incident on an image forming material as disclosed in JP-A-5-113548 and a multi-mode disclosed in WO95 / 31754 and the like. Methods using lasers are known, and it is preferable to use these techniques.

For exposing the photosensitive heat-developable image-forming material of the present invention, see SPIE vol.169 Laser Printing pages 116-128 (197
9), it is preferable to expose the laser beams so as to overlap each other so as to make the scanning lines invisible, as disclosed in JP-A-4-51043 and WO95 / 31754.

FIG. 1 shows an example of the configuration of a heat developing machine used for the heat development of the photosensitive heat-developable image forming material of the present invention.
FIG. 1 is a side view of the heat developing machine. The heat developing machine of FIG. 1 carries a pair of carry-in rollers 11 for carrying the heat-developable image forming material 10 into a heating unit while correcting and preheating the heat-developable image forming material 10 into a planar shape.
(A lower roller is a heat roller) and a pair of carry-out rollers 12 for carrying out the heat-developed image-forming material 10 after heat development after carrying out the heat development while carrying out the flattened shape. The heat-developable image forming material 10 is thermally developed while being transported from the carry-in roller pair 11 to the carry-out roller pair 12. In the conveying means for conveying the heat-developable image forming material 10 during the heat development, a plurality of rollers 13 are provided on the side in contact with the surface having the image forming layer, and the non-woven fabric ( For example, a smooth surface 14 to which an aromatic polyamide or Teflon) is attached is provided. The back surface of the heat-developable image forming material 10 is conveyed by sliding a plurality of rollers 13 in contact with the surface having the image forming layer. As the heating means, a heater 15 is provided at an upper portion of the roller 13 and a lower portion of the smooth surface 14 so as to be heated from both sides of the heat-developable image forming material 10. As a heating means in this case, a plate heater or the like can be used. Although the clearance between the roller 13 and the smooth surface 14 varies depending on the member of the smooth surface, it is appropriately adjusted to a clearance that allows the heat-developable image forming material 10 to be transported. Preferably 0
１1 mm.

Surface Material of Roller 13 and Smooth Surface 1
The member No. 4 is durable at high temperatures and is a heat-developable image forming material 1
Any material may be used as long as it does not hinder the conveyance of 0, but the material of the roller surface is preferably silicone rubber, and the material of the smooth surface is preferably a nonwoven fabric made of aromatic polyamide or Teflon (PTFE). It is preferable to use a plurality of heaters as the heating means and to set the heating temperature freely.

The heating section is composed of a preheating section A having a carry-in roller pair 11 and a heat development processing section B having a heating heater 15, and a preheating section A upstream of the heat development processing section B. Is lower than the heat development temperature (for example, 10 to 30).
It is preferable that the temperature is set so as not to cause development unevenness at a temperature higher than the glass transition temperature (Tg) of the support of the heat-developable image forming material 10.

Further, a guide plate 16 is provided downstream of the heat development processing section B, and a slow cooling section C having the carry-out roller pair 12 and the guide plate 16 is provided.

The guide plate is preferably made of a material having a low thermal conductivity, and is preferably cooled gradually.

Although the above has been described with reference to the illustrated examples, the present invention is not limited to this. For example, the thermal developing machine used in the present invention, such as that described in JP-A-7-13294, may have various structures. In the case of the multi-stage heating method preferably used in the present invention, two or more heat sources having different heating temperatures may be provided, and heating may be performed continuously at different temperatures.

[0193]

The present invention will be specifically described below with reference to examples. Example 1 (Preparation of silver salt of organic acid emulsion A) 933 g of behenic acid was added to 12 liters of water, and while maintaining at 90 ° C, 48 g of sodium hydroxide was added.
A solution prepared by dissolving 63 g of sodium carbonate in 1.5 liters of water was added. After stirring for 30 minutes, the temperature was raised to 50 ° C., and 1.1 liter of a 1 wt% aqueous solution of N-bromosuccinimide (C-10) was added.
Next, 2.3 liters of a 17 wt% silver nitrate aqueous solution was gradually added thereto with stirring. Further, the liquid temperature was set to 35 ° C., and 1.5 liters of a 2 wt% aqueous solution of potassium bromide was added over 2 minutes with stirring, followed by stirring for 30 minutes.
2.4 liters were added. To this aqueous mixture was added 3300 g of a 1.2 wt% solution of polyvinyl acetate in butyl acetate with stirring, and the mixture was allowed to stand for 10 minutes, separated into two layers, the aqueous layer was removed, and the remaining gel was washed twice with water. The mixture of the gel-like silver behenate and silver bromide thus obtained was treated with polyvinyl butyral (Denka butyral # 3 manufactured by Denki Kagaku Kogyo KK).
000-K) in 1800 g of a 2.6 wt% 2-butanone solution, and further, 600 g of polyvinyl butyral (Denka butyral # 4000-2 manufactured by Denki Kagaku Kogyo KK), 300 g of isopropyl alcohol
And an organic silver salt emulsion (acicular particles having an average minor axis of 0.05 μm, an average major axis of 1.2 μm, and a coefficient of variation of 25%).

(Preparation of Emulsion Layer Coating Solution A) Each of the chemicals was added to the above-obtained organic acid silver emulsion in the following amount per mole of silver. Sodium phenylthiosulfonate at 25 ° C
10 mg, 40 mg of sensitizing dye A, 8 mg of sensitizing dye B, and the kind and amount of the heteroaromatic mercapto compound or heteroaromatic disulfide compound of the present invention shown in Table 1 (the addition amounts were silver halide and organic acid silver). (The same applies to the super-high contrast agent and the compound of the formula (1). These compounds are added in the same manner in the following examples.) Was added. 21.5 g of 4-chlorobenzophenone-2-carboxylic acid (C-1), 580 g of 2-butanone, and 220 g of dimethylformamide were added with stirring and left for 3 hours. Then, 4.5 g of 4,6-ditrichloromethyl-2-phenyltriazine (C-2) and 1,1-bis (2-hydroxy-3,5-
Dimethylphenyl) -3,5,5-trimethylhexane (C-3)
160 g, 15 g of phthalazine (C-4), 5 g of tetrachlorophthalic acid (C-5), the kind and amount of the super-high contrast agent shown in Table 1, and the compound of the formula (1) of the present invention shown in Table 1 Kinds and amounts, 1.1 g of Megafax F-176P (fluorinated surfactant manufactured by Dainippon Ink and Chemicals, Inc.), 590 g of 2-butanone, and 10 g of methyl isobutyl ketone were added with stirring.

(Preparation of Coating Solution A for Emulsion Surface Protective Layer) CAB171-15
75 g of S (cellulose acetate butyrate manufactured by Eastman Chemical Co., Ltd.), 5.7 g of 4-methylphthalic acid (C-6), 1.5 g of tetrachlorophthalic anhydride (C-7), 2-tribromomethylsulfonylbenzothiazole ( C-8) 10g, phthalazone (C-
9) 2g, Megafax F-176P 0.3g, Sildex H31
(Doukai Chemical's spherical silica average size 3μm) 2g, sumi
A solution was prepared by dissolving 5 g of dur N3500 (polyisocyanate manufactured by Sumitomo Bayer Urethane) in 3070 g of 2-butanone and 30 g of ethyl acetate.

(Preparation of Support Having Back Surface) 6 g of polyvinyl butyral (Denka Butyral # 4000-2, manufactured by Denki Kagaku Kogyo KK), Sildex H121 (average size of spherical silica 12 μm, manufactured by Dokai Chemical Co., Ltd.) 0.2 g, Sildex H51 (Tokai Chemical Co., Ltd., 0.2 g of spherical silica average size: 5 μm), 0.1 g of Megafax F-176P, and 64 g of 2-propanol were added with stirring to dissolve and mix. Furthermore, a coating solution prepared by dissolving 420 mg of dye A in 10 g of methanol and 20 g of acetone and a solution of 0.8 g of 3-isocyanatomethyl-3,5,5-trimethylhexyl isocyanate in 6 g of ethyl acetate were added to prepare a coating solution. did.

A coating solution for the back side was applied on a polyethylene terephthalate film having a moisture-proof undercoat containing vinylidene chloride on both sides so as to have an optical density of 0.7 at 780 nm.

After the emulsion layer coating solution was coated on the support prepared as described above so that the silver content was 2 g / m ² , the emulsion surface protective layer coating solution was dried on the emulsion surface to a dry thickness of 5 μm. And a sample of the heat-developable image forming material was obtained.

[0199]

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[0200]

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(Evaluation of photographic performance) The film was exposed to xenon flash light having an emission time of 10 ^-4 sec through a step wedge through an interference filter having a peak at 780 nm.
After processing (developing) at 20 ° C. for 20 seconds, the obtained image was evaluated with a densitometer. The measurement results were evaluated in terms of Dmax, Dmin (fog), and sensitivity (the reciprocal of the ratio of the exposure amount that gives a density 1.5 higher than Dmin). The sensitivity was shown as a relative value with the sensitivity of Sample No. 103 in Table 1 as 100. Also, in the characteristic curve, the density is 0.
The gradient of the straight line connecting points 3 and 3.0 is shown as gradation γ.

(Aging test)
After 3 days of aging under the condition of 5% humidity, photographic performance was evaluated. Table 1 shows the results. The structure of the super-high contrast agent and the structure of the heteroaromatic mercapto compound or disulfide compound used in Table 1 are shown below.

[0203]

[Table 1]

[0204]

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[0205]

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(Results) By using the compound of the present invention in combination, it is possible to satisfy high Dmax and ultra-high contrast
A photosensitive heat-developable image-forming material having good storage stability was obtained.

Example 2 << Preparation of Silver Halide Emulsion >> (Emulsion A) 11 g of phthalated gelatin and 700 g of bromide in 700 ml of water
30 mg of lithium, 10 mg of sodium benzenethiosulfonate
After dissolving and adjusting the pH to 5.0 at a temperature of 40 ° C, silver nitrate 18.
1 mol / l of 159 ml of aqueous solution containing 6 g and potassium bromide
, (NH_Four)_TwoRhCl_Five(H_TwoO) 5 × 10 ^-6Mol / l, K_ThreeIrC
l₆2 × 10^-FiveKeep the aqueous solution containing mol / l at pAg7.7
While taking control for 6 minutes 30 seconds by double jet method
Was added. Then, with 476 ml of an aqueous solution containing 55.5 g of silver nitrate
1 mol / l potassium bromide, K_ThreeIrCl₆2 × 10 ^-FiveMole
/ L while maintaining pAg7.7
Add by control double jet method over 28 minutes and 30 seconds
did. After that, the pH is lowered to cause coagulation sedimentation and desalination treatment,
0.17 g of Compound A, deionized gelatin (containing calcium
23.7g added, adjusted to pH5.9, pAg8.0
did. The obtained particles have an average particle size of 0.08 μm, projection surface
Cubic particles with a product variation coefficient of 9% and a (100) plane ratio of 90%.

The silver halide grains thus obtained were heated to 60 ° C., and 76 μmol of sodium benzenethiosulfonate was added per 1 mol of silver. After 3 minutes, 154 μm of sodium thiosulfate was added.
Mol, and the mixture was aged for 100 minutes.
Methyl-1,3,3a, 7-tetrazaindene is 5 × 10
After adding ^-4 mol, the temperature was lowered to 40 ° C.

Thereafter, the temperature was maintained at 40 ° C.
12.8 × 10 ⁻⁴ mol of the following sensitizing dye C, the heteroaromatic mercapto compound or the heteroaromatic disulfide compound of the present invention (type and amount are shown in Table 2 with respect to 1 mol. The same standards are added with stirring.
After one minute, the mixture was rapidly cooled to 30 ° C. to complete the preparation of silver halide emulsion A.

[0210]

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<< Preparation of Organic Acid Silver Dispersion >> 43.8 g of behenic acid (product name: Edenor C22-85R) manufactured by Henkel, 700 ml of distilled water,
70 ml of tert-butanol, 123 ml of 1N-NaOH aqueous solution at 85 ° C. for 120
The reaction was carried out for 75 minutes, and the temperature was lowered to 75 ° C. to prepare an organic acid alkali metal salt solution. A reaction vessel containing 600 ml of distilled water and 25 ml of tert-butanol was kept at 35 ° C., and the organic acid alkali salt solution prepared above and 112.5 ml of an aqueous solution of silver nitrate containing 19.2 g of silver nitrate and 20 cc of 1N nitric acid were added over 5 minutes. . At this time, the addition of the aqueous silver nitrate solution was started 30 seconds before the addition of the organic acid alkali salt solution, and the addition of the organic acid alkali metal salt solution was completed 30 seconds after the completion of the addition of the silver nitrate aqueous solution. After completion of the addition, the mixture was allowed to stand for 20 minutes, and the temperature was lowered to 30 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm. The solid content thus obtained was treated as a wet cake without drying, and the dry solid content was 100%.
g wet cake, polyvinyl alcohol
(Product name: PVA-217) Add 7.4g and water to make the total amount 38
After 5 g, it was predispersed with a homomixer.

Next, the pre-dispersed undiluted solution is dispersed in a disperser (trade name: Microfluidizer M-110S-EH, manufactured by Microfluidics International Corporation, using G10Z interaction chamber).
The pressure was adjusted to 1750 kg / cm ² and the mixture was treated three times to obtain a silver behenate dispersion B. The silver behenate particles contained in the silver behenate dispersion thus obtained were needle-like particles having an average minor axis of 0.04 μm, an average major axis of 0.4 μm, and a coefficient of variation of 20%. For particle size measurement, use MasterSizerX manufactured by Malvern Instruments Ltd.
I went in. In the cooling operation, a coiled heat exchanger was mounted before and after the interaction chamber, and the temperature of the refrigerant was adjusted to a desired dispersion temperature.

<< Preparation of solid fine particle dispersion of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane >> 1,1-bis (2-hydroxy-3, 5-dimethylphenyl) -3,5,5-trimethylhexane 20 g for Kuraray Co., Ltd.
3.0 g of MP-203 made of MP polymer and 77 ml of water were added, and the mixture was stirred well and left as a slurry for 3 hours. Then 0.5mm
Of zirconia beads was placed in a vessel together with the slurry, and dispersed with a dispersing machine (1 / 4G sand grinder mill: manufactured by Imex Co., Ltd.) for 3 hours to prepare a reducing agent solid fine particle dispersion. The particle size is 80 wt% of the particles 0.3
It was not less than μm and not more than 1.0 μm.

<< Preparation of Solid Fine Particle Dispersion of Compound C >> MP-203 of MP Polymer manufactured by Kuraray Co., Ltd. was added to 30 g of Compound C.
6.0 g and water 84 ml were added and stirred well to obtain a slurry.
Left for 3 hours. Thereafter, a solid fine particle dispersion of the antifoggant was prepared in the same manner as the preparation of the reducing agent solid fine particle dispersion. As for the particle diameter, 80 wt% of the particles were 0.3 μm or more and 1.0 μm or less.

<< Preparation of Solid Fine Particle Dispersion of the Compound of the Formula (1) >> 10 g of the compound of the formula (1) was added to M by Kuraray Co., Ltd.
3 g of P-polymer MP-203 and 87 ml of water were added, stirred well, and left as a slurry for 3 hours. Thereafter, a solid fine particle dispersion of the compound of the formula (1) was prepared in the same manner as in the preparation of the reducing agent solid fine particle dispersion. Particle size is 80
wt% was 0.3 μm or more and 1.0 μm or less.

<< Preparation of Emulsion Layer Coating Solution >> The following binder, material, and silver halide emulsion A were added to 1 mol of silver of the organic acid silver microcrystal dispersion prepared above, and water was added. Thus, an emulsion layer coating solution was obtained. The addition amounts of the compound of the formula (1) and the super-high contrast agent are the same as in Example 1.

Binder; Luckstar 3307B 406 g as solids (manufactured by Dainippon Ink and Chemicals, Inc .; glass transition temperature of 17 ° C. with SBR latex) 1,1-bis (2-hydroxy-3,5-dimethylphenyl)- 3,5,5-trimethylhexane 119 g as solid content Compound C 30 g as solid content Sodium benzenethiosulfonate 0.44 g 5-methylbenzotriazole 1.23 g polyvinyl alcohol (MP-203 manufactured by Kuraray Co., Ltd.) 20 g 6-iso-propyl Phthalazine 17 g Sodium dihydrogen orthophosphate 0.13 g Dye B 0.43 g Compound of formula (1) Kind and amount described in Table 2 Silver halide emulsion A 0.05 mol as Ag amount Ultra-high contrast agent Kind and amount described in Table 2

[0218]

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<< Preparation of Coating Solution for Emulsion Surface Protective Layer >> Solid Content 44 wt.
% Polymer latex (methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate methacrylic acid = 59/9/26/5/1)
Copolymer glass transition temperature 54 ° C. in body, of H ₂ O was added Compound D as a film-forming aid to 15 wt%) 102 g, carnauba wax (Chukyo Yushi Co., Ltd., Cellosol 524) 30 wt% solution 1.89
g, compound E 0.188 g, 4-methylphthalic acid (compound F)
1.4 × 10 ^-4 mol / mol-Ag, matting agent (polystyrene particles,
0.56 g of an average particle size of 7 μm) and 0.4 g of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA-235) were added, and H ₂ O was further added to obtain a coating solution.

[0220]

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<< Preparation of PET Support with Back / Undercoat Layer >> (1) Support Using terephthalic acid and ethylene glycol, IV (intrinsic viscosity) = 0.66 (phenol / tetrachloroethane = 6 / 4 (measured at 25 ° C. in weight ratio). After pelletizing this, it was dried at 130 ° C for 4 hours,
After being melted at 00 ° C., the film was extruded from a T-die and quenched to prepare an unstretched film having a thickness of 120 μm after heat setting.

This was longitudinally stretched 3.3 times using rolls having different peripheral speeds, and then horizontally stretched 4.5 times using a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. After that, it was heat-set at 240 ° C. for 20 seconds and relaxed 4% in the lateral direction at the same temperature. Then, after slitting the chuck part of the tenter, knurling is performed on both ends, and 4.8 kg / cm ²
Rolled up. In this way, width 2.4m, length 3500m,
A roll having a thickness of 120 μm was obtained.

(2) Undercoat layer (a) Polymer latex-styrene / butadiene / hydroxyethyl methacrylate / divinylbenzene = 67/30 / 2.5 / 0.5 (% by weight) 160 mg / m ² 2,4-dichloro-6-hydroxy- s-Triazine 4mg / m ² Matting agent (polystyrene, average particle size 2.4μm) 3mg / m ²

(3) Undercoat layer (b) Deionized gelatin (Ca ²⁺ content 0.6 ppm, jelly strength 230 g) 50 mg / m ²

(4) Conductive layer Julimer ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.) 96 mg / m ² Gelatin 50 mg / m ² Compound A 0.2 mg / m ² Polyoxyethylene phenyl ether 10 mg / m ² Sumitex Resin M -3 18mg / m ² (Water-soluble melamine compound, manufactured by Sumitomo Chemical Co., Ltd.) Dye B Coating amount that optical density of 783nm becomes 1.2 SnO ₂ / Sb (9/1 weight ratio, needle-like fine particles, long axis / short Shaft = 20-30; manufactured by Ishihara Sangyo Co., Ltd.) 160 mg / m ² Matting agent (polymethyl methacrylate, average particle size 5 μm) 7 mg / m ²

(5) Protective layer Polymer latex-methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / methacrylic acid = 59/9/26/5/1 (weight% copolymer) 1000 mg / m ² polystyrene sulfonate (molecular weight: 1000-5000) 2.6 mg / m ² cellosol 524 (manufactured by Chuo Yushi Co., Ltd.) 25 mg / m ² Sumitex Resin M-3 218 mg / m ² (water-soluble melamine compound, Sumitomo Chemical Co., Ltd.) (Made by Corporation)

An undercoat layer (a) and an undercoat layer (b) are formed on one side of the support.
Were sequentially applied and dried at 180 ° C. for 4 minutes. Then, a conductive layer and a protective layer are sequentially coated on the opposite side to which the undercoat layer (a) and the undercoat layer (b) have been applied, and dried at 180 ° C. for 30 seconds, respectively, for a PET support having a back / undercoat layer. Was prepared.

The PET support provided with the back / undercoat layer thus prepared was placed in a heat treatment zone having a total length of 30 m set at 150 ° C., and was transported under its own weight at a tension of 1.4 kg / cm ² and a transport speed of 20 m / min. Thereafter, the film was passed through a zone at 40 ° C. for 15 seconds, and wound up at a winding tension of 10 kg / cm ² .

[0229]

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<< Preparation of heat-developable image-forming material >> The above-mentioned emulsion layer coating solution was coated on the undercoat layer of the PET support provided with the back / undercoat layer so as to have a coating silver amount of 1.8 g / m ² . . Further, the coating solution for the emulsion surface protective layer was applied thereon so that the coating amount of the solid content of the polymer latex was 3.2 g / m ² .

(Heat Developing Treatment) The exposed sample was subjected to the heat developing machine shown in FIG. 1, and the surface of the heat developing treatment roller was made of silicone rubber and the smooth surface was made of an aromatic polyamide nonwoven fabric.
The pre-heating unit was subjected to a heat development treatment at 90 to 100 ° C. for 5 seconds and a heat development processing unit at 120 ° C. for 20 seconds. The temperature distribution in the width direction is ± 1 ° C
Met.

(Evaluation of Photographic Performance) The obtained images were evaluated using a Macbeth TD904 densitometer (visible density). The measurement results are Dmax, Dmin (fog), sensitivity (reciprocal of the ratio of the exposure that gives a density 1.0 higher than Dmin), and contrast (gradation).
Was evaluated. The sensitivity of Sample No. 206 in Table 2 was set to 100. Contrast was represented by the slope of a straight line connecting points of density 0.3 and 3.0, with the logarithm of the exposure amount as the horizontal axis.

(Aging Test) The coated sample was heated at 50 ° C.
After 3 days of aging under the condition of 5% humidity, photographic performance was evaluated. Table 2 shows the results. The structure of the superhigh contrast agent and the structure of the heteroaromatic mercapto compound or the heteroaromatic disulfide compound used in Table 2 are the same as those shown in Example 1.

[0234]

[Table 2]

(Results) By using the compound of the present invention in combination, it is possible to satisfy high Dmax and ultra-high contrast
A photosensitive heat-developable image-forming material having good storage stability was obtained.

Example 3 A similar experiment was carried out in the same manner as in Example 2 except that A-20 and A-35 were used in place of the compound A-26 of the formula (1), and the same effect was obtained. It turned out to be obtained.

[0237]

According to the present invention, the performance as a high-contrast photosensitive heat-developable image forming material is excellent, and the storage stability is good.

[Brief description of the drawings]

FIG. 1 is a side view illustrating a configuration example of a heat developing machine.

[Explanation of symbols]

 Reference Signs List 10 heat-developed image forming material 11 carry-in roller pair 12 carry-out roller pair 13 roller 14 smooth surface 15 heating heater 16 guide plate A preheating section B heat development processing section C slow cooling section

Claims (5)

[Claims] 1. At least one surface of a support,
(A) photosensitive silver halide, (b) a reducible silver salt, (c) a reducing agent, (d) a binder, and (e) silver 1
At least one of a heteroaromatic mercapto compound and a heteroaromatic disulfide compound in an amount of 10 ^-3 to 1 mol per mol, and (f) at least one of the compounds represented by the formula (1). A photosensitive heat-developable image-forming material comprising one kind. Embedded image [In the formula (1), M represents a hydrogen atom or a k-valent cation, and R represents a substituent. n is an integer of 1 to 4;
When ≧ 2, a plurality of Rs may be the same or different. k is an integer of 1 or more, and when M is a hydrogen atom, k = 1
It is. ] 2. The photosensitive heat-developable image forming material according to claim 1, comprising at least one of the heteroaromatic mercapto compound and the heteroaromatic disulfide compound as a supersensitizer. 3. The photosensitive heat-developable image forming material according to claim 1, further comprising a super-high contrast agent. 4. The photosensitive heat according to claim 3, wherein at least one of a substituted alkene derivative, a substituted isoxazole derivative and a specific acetal compound represented by the following formulas (2) to (4) is used as a super-high contrast agent. Developed image forming material. Embedded image [In the formula (2), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent, and Z represents an electron-withdrawing group. In the formula (2), R ¹ and Z, R ² and R ³ , R ¹ and R ² , and R ³ and Z may be mutually bonded to form a cyclic structure. In the formula (3), R ⁴ represents a substituent. In the formula (4), X and Y each independently represent a hydrogen atom or a substituent, and A and B each independently represent an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group. , A heterocyclic oxy group, a heterocyclic thio group, or a heterocyclic amino group. In the formula (4), X and Y, and A and B may be bonded to each other to form a cyclic structure. ] 5. The method according to claim 1, further comprising a hydrazine compound.
Any one of the photosensitive heat-developable image forming materials.