JP2001133925A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat developable photosensitive material having high sensitivity and high image quality and excellent in preservability in the undeveloped state as a material for a medical image and for a photomechanical process. SOLUTION: In the heat developable photosensitive material with at least one photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one face of the substrate, the average grain size of the photosensitive silver halide is 0.001-0.06 μm, two or more organic polyhalogen compounds are contained and at least one of the organic polyhalogen compounds is represented by formula 1 [where Z1 and Z2 are each halogen, X1 is H or an electron withdrawing group, Y1 is -0- or -SO2-; Q is arylene or a divalent heterocyclic group, L is a combining group, W1 and W2 are each H, alkyl, aryl or a heterocyclic group and (n) is 0 or 1].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material.

[0002]

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

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

On the other hand, thermal image forming systems using organic silver salts are disclosed in, for example, US Pat.
No. 4,570,757 and D.C. Crostabore (K
"The heat-treated silver system by losterboer)
(Thermally Processed SilverSystems) "(Imaging Processes and Materials (Imaging P
rocesses and Materials) Neblette 8th edition, J. Sturge
(Sturge), V. Walworth, A. Shepp (S
hepp), edited in Chapter 9, p. 279, 1989). In particular, photothermographic materials generally include a catalytically active amount of a photocatalyst (e.g., silver halide), a reducing agent, a reducible silver salt (e.g., an organic silver salt), and if necessary, a toning agent for controlling the color tone of silver. And an image forming layer (photosensitive layer) dispersed in a binder matrix. The photothermographic material is heated to a high temperature (for example, 80 ° C. or higher) after image exposure,
A black silver image is formed by a redox reaction between silver halide or a reducible silver salt (functioning as an oxidizing agent) and a reducing agent. The oxidation-reduction reaction is accelerated by the catalytic action of the latent image of silver halide generated by exposure. Therefore, a black silver image is formed in the exposed area. It is disclosed in many documents including U.S. Pat. No. 2,910,377 and Japanese Patent Publication No. 43-4924. The thermal image forming system using these organic silver salts can achieve image quality and color tone that are satisfactory as medical images.

In the thermal image forming system using the above-mentioned organic silver salt, it has been found that the sensitivity can be increased by increasing the development starting point by reducing the grain size of silver halide. When the size is reduced, there is a problem that the sensitivity is significantly reduced when the photosensitive material is stored at a high temperature (for example, at 60 ° C. for 7 hours).

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. More specifically, the present invention relates to a photothermographic material for use in medical imaging or photoengraving, which has high sensitivity and excellent preservability when undeveloped (especially preservability at high temperatures). It is to provide materials.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems and completed the present invention. That is, the present invention provides at least one support on one surface of a support.
In a photothermographic material having two types of photosensitive silver halide, non-photosensitive organic silver salt, a reducing agent for silver ions and a binder, the average grain size of the photosensitive silver halide is
0.001 μm or more and 0.06 μm or less, and at least 2
Containing at least one organic polyhalogen compound, at least one of which is of the formula (1):

Embedded image[In the formula (1), Z₁And Z_TwoAre independent
X represents a halogen atom ¹Is a hydrogen atom or electron-withdrawing property
Y represents a group₁Is -CO- group or SO_Two-Represents a group
And Q represents an arylene group or a divalent heterocyclic group.
L represents a linking group;₁And W_TwoAre independent
A hydrogen atom, an alkyl group, an aryl group or a heterocyclic group
Represents n represents 0 or 1. ] Represented by organic
Photothermographic exposure characterized by being a polyhalogen compound
Provide materials.

According to a preferred embodiment of the present invention, the layer containing the organic polyhalogen compound represented by the formula (1) is formed by an aqueous coating solution, and the organic compound represented by the formula (1) The photothermographic material according to the above (1), wherein the polyhalogen compound is added to the aqueous coating solution as an aqueous dispersion.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

In the photothermographic material of the present invention, at least 2
More than one kind of organic polyhalogen compound is used, and at least one of them is an organic polyhalogen compound represented by the above formula (1). As other organic polyhalogen compounds, compounds represented by the following formula (II) are preferable.

Embedded image (In the formula (II), A represents an alkyl group, an aryl group or a heterocyclic group, Z ₃ and Z ₄ each independently represent a halogen atom, X ₂ represents a hydrogen atom or an electron-withdrawing group, and Y represents —C (＝ O) —, —SO— or SO ₂ —, and n represents 0 or 1.)

The aryl group represented by A may be either a single ring or a condensed ring, and is preferably a monocyclic or bicyclic aryl group having 6 to 30 carbon atoms (eg, phenyl, naphthyl, etc.) More preferably, they are a phenyl group and a naphthyl group, and still more preferably a phenyl group.

The heterocyclic group represented by A is a 3- to 10-membered saturated or unsaturated heterocyclic group containing at least one of N, O and S atoms, and these may be monocyclic. And may further form a condensed ring with another ring. As the heterocyclic group, preferably a 5- or 6-membered unsaturated heterocyclic group optionally having a condensed ring can be used, and more preferably a 5- or 6-membered unsaturated heterocyclic group optionally having a condensed ring. It is an aromatic heterocyclic group. More preferably, it is a 5- or 6-membered aromatic heterocyclic group containing a nitrogen atom,
Particularly preferred is an aromatic heterocyclic group which may have a 5- or 6-membered condensed ring containing 1 to 4 nitrogen atoms.

Specific examples of the heterocycle in the heterocyclic group include, for example, pyrrolidine, piperidine, piperazine, morpholine, thiophene, furan, pyrrole, imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, Indazole, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzothiazole, benzoselenazole, india Renin, tetrazaindene and the like. Preferably as a heterocycle, imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine,
Triazole, triazine, indole, indazole, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole,
Oxazole, benzimidazole, benzoxazole, benzthiazole, indolenine, tetrazaindene, more preferably imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline , Quinazoline, cinnoline, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzothiazole, tetrazaindene, more preferably imidazole, pyridine, pyrimidine, pyrazine,
Pyridazine, triazole, triazine, thiadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, benzimidazole and benzthiazole, particularly preferably pyridine, thiadiazole, quinoline and benzthiazole.

The aryl group or heterocycle represented by A may have a substituent in addition to-(Y) _n -C (X ₂ ) (Z ₃ ) (Z ₄ ). As the substituent, for example, an alkyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 carbon atom)
To 12, particularly preferably having 1 to 8 carbon atoms, for example, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-octyl group , N-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group and the like. ), An alkenyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms,
Particularly preferably, it has 2 to 8 carbon atoms, for example, a vinyl group,
Allyl group, 2-butenyl group, 3-pentenyl group, etc.), alkynyl group (preferably having 2 to 2 carbon atoms).
0, more preferably 2 to 12, particularly preferably 2 to 8, for example, a propargyl group, a 3-pentynyl group and the like; an aryl group (preferably having 6 to 30 carbon atoms;
More preferably, it has 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenyl group, a p-methylphenyl group, and a naphthyl group, and an amino group (preferably having 0 to 20 carbon atoms). Preferably 0 to 1 carbon atoms
0, particularly preferably 0 to 6 carbon atoms, for example, an amino group, a methylamino group, a dimethylamino group, a diethylamino group, a dibenzylamino group and the like; an alkoxy group (preferably 1 to 20 carbon atoms) It preferably has 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, for example, methoxy, ethoxy, butoxy and the like, and aryloxy group (preferably 6 to 2 carbon atoms).
0, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as a phenyloxy group and a 2-naphthyloxy group, and an acyl group (preferably 1 to 20 carbon atoms) Preferably C1-16,
Particularly preferably, it has 1 to 12 carbon atoms, for example, acetyl group, benzoyl group, formyl group, pivaloyl group, etc.), alkoxycarbonyl group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, Particularly preferably, it has 2 to 12 carbon atoms, for example, methoxycarbonyl group, ethoxycarbonyl group and the like), and aryloxycarbonyl group (preferably 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably Carbon number 7
To 10, for example, a phenyloxycarbonyl group. ), An acyloxy group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 16 carbon atoms, particularly preferably having 2 to 10 carbon atoms, and examples thereof include an acetoxy group and a benzoyloxy group), and an acylamino group (preferably Is 2 to 20 carbon atoms, more preferably 2 carbon atoms
-16, particularly preferably 2-10 carbon atoms, for example, acetylamino group, benzoylamino group and the like), alkoxycarbonylamino group (preferably 2-20 carbon atoms, more preferably 2-16 carbon atoms, Particularly preferably, it has 2 to 12 carbon atoms, for example, a methoxycarbonylamino group and the like, and an aryloxycarbonylamino group (preferably 7 to 20, more preferably 7 to 16, particularly preferably carbon number) 7 to 12, for example, a phenyloxycarbonylamino group or the like), a sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, particularly preferably having 1 to 12 carbon atoms, Examples thereof include a methanesulfonylamino group and a benzenesulfonylamino group), sulfamoi Group (preferably having 0 to 20 carbon atoms,
More preferably, it has 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms. Examples thereof include a sulfamoyl group, a methylsulfamoyl group, a dimethylsulfamoyl group, a phenylsulfamoyl group and the like, a carbamoyl group ( Preferably it has 1 to 20 carbon atoms, more preferably 1 carbon atom
To 16 and particularly preferably 1 to 12 carbon atoms, for example, carbamoyl group, methylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group and the like, alkylthio group (preferably 1 to 20 carbon atoms, more preferably 1 to 16, particularly preferably 1 carbon atom
To 12, and examples thereof include a methylthio group and an ethylthio group), an arylthio group (preferably having 6 carbon atoms).
-20, more preferably 6-16 carbon atoms, particularly preferably 6-12 carbon atoms, such as a phenylthio group, etc., and a sulfonyl group (preferably 1-2 carbon atoms).
0, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, a mesyl group, a tosyl group, a phenylsulfonyl group and the like, a sulfinyl group (preferably 1 to 20 carbon atoms, Preferably 1 carbon atom
To 16, particularly preferably having 1 to 12 carbon atoms, such as a methanesulfinyl group and a benzenesulfinyl group, and a ureido group (preferably having 1 to 2 carbon atoms).
0, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, a ureido group, a methylureide group, a phenylureide group and the like; a phosphoric acid amide group (preferably 1 to 16 carbon atoms) 20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, for example, a diethylphosphoramide group, a phenylphosphoramide group, etc.), a hydroxy group, a mercapto group, a halogen atom (for example, Fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, heterocyclic group (for example, imidazolyl group, pyridyl group, furyl group, piperidyl group) And morpholino groups). These substituents may be further substituted. When there are two or more substituents, they may be the same or different.

The substituent is preferably an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an acyloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, an acylamino group, an alkoxycarbonylamino group, Aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, sulfonyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group, sulfo group, carboxyl group, nitro group, heterocyclic group, and more preferably Represents an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an acylamino group,
Alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, ureido group, phosphoric amide group, halogen atom, cyano group, nitro group, heterocyclic group,
More preferred are an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an acylamino group, a sulfonylamino group, a sulfamoyl group, a carbamoyl group, a halogen atom, a cyano group, a nitro group, and a heterocyclic group, and particularly preferred. An alkyl group, an aryl group, a sulfamoyl group, a carbamoyl group, and a halogen atom.

The alkyl group represented by A is a straight-chain, branched-chain,
It may be cyclic or a combination thereof, preferably has 1 to 30 carbon atoms, more preferably has 1 to 15 carbon atoms, such as methyl group, ethyl group, n-propyl group, isopropyl And tertiary octyl groups.

The alkyl group represented by A is-(Y) _n -C
It may have a substituent in addition to (X ₂ ) (Z ₃ ) (Z ₄ ). Examples of the substituent include the same substituents as those exemplified for the case where A is a heterocyclic group or an aryl group. Preferably as the substituent, a carbamoyl group, a sulfamoyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an acyloxy group, an acylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonylamino group, an alkylthio group, and an arylthio group Group, ureido group, phosphoric amide group, hydroxy group, halogen atom, heterocyclic group, more preferably carbamoyl group, sulfamoyl group, aryl group, alkoxy group, aryloxy group, acylamino group, alkoxycarbonylamino group, aryl Oxycarbonylamino group, sulfonylamino group, ureido group,
It is a phosphoric amide group or a halogen atom, and more preferably a carbamoyl group, a sulfamoyl group, an aryl group, an alkoxy group, an aryloxy group, an acylamino group, a sulfonylamino group, a ureido group, or a phosphoric amide group. These substituents may be further substituted. When there are two or more substituents, they may be the same or different.

Y is -C (= O)-, -SO- or SO
₂ - represents, preferably represents -C (= O) - or -SO ₂ -
And more preferably —SO ₂ —. n represents 0 or 1, and is preferably 1. Z ₃ and Z ₄ are
Each independently represents a halogen atom. The halogen atoms represented by Z ₃ and Z ₄ may be the same or different from each other, and are, for example, a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, preferably a chlorine atom, a bromine atom and an iodine atom. Preferably a chlorine atom, a bromine atom,
Particularly preferred is a bromine atom.

X ₂ represents a hydrogen atom or an electron-withdrawing group. Preferably, the electron-withdrawing group represented by X ₂ is σ
a substituent (including an atom) having a positive p-value,
It is preferably a substituent of 0.01 or more, more preferably a substituent of 0.1 or more. Regarding Hammett's substituent constant, see Journal of Medicinal Chemistry, 197.
3, Vol. 16, No. 11, 1207-1216 etc. can be referred to. Examples of the electron-withdrawing group include a halogen atom (fluorine atom (σp value: 0.06), a chlorine atom (σp
Value: 0.23), bromine atom (σp value: 0.23), iodine atom (σp value: 0.18); trihalomethyl group (tribromomethyl group (σp value: 0.29), trichloromethyl group (Σp value: 0.33), trifluoromethyl group (σp value: 0.54)); cyano group (σp value: 0.6)
6); a nitro group (σp value: 0.78); an aliphatic, aryl, or heterocyclic sulfonyl group (eg, methanesulfonyl (σp value: 0.72));
Alternatively, a heterocyclic acyl group (for example, an acetyl group (σp
Value: 0.50), benzoyl group (σp value: 0.4
3)); alkynyl group (for example, C≡CH (σp value:
0.23)); an aliphatic, aryl, or heterocyclic oxycarbonyl group (for example, a methoxycarbonyl group (σ
p value: 0.45), a phenoxycarbonyl group (σp value:
0.44)); carbamoyl group (σp value: 0.36);
And a sulfamoyl group (σp value: 0.57).

X ₂ is preferably an electron-withdrawing group, more preferably a halogen atom; an aliphatic, aryl, or heterocyclic sulfonyl group; an aliphatic, aryl, or heterocyclic acyl group; Or a heterocyclic oxycarbonyl group; a carbamoyl group; a sulfamoyl group, particularly preferably a halogen atom. Among the halogen atoms, a chlorine atom, a bromine atom and an iodine atom are preferred, a chlorine atom and a bromine atom are more preferred, and a bromine atom is particularly preferred.

Preferred examples of the compound represented by the general formula (II) include a compound represented by the following general formula (II-a).

Embedded image

In the formula, A has the same meaning as that in formula (II), and the preferred range is also the same. Further, the substituent that can be substituted on A has the same meaning as the substituent that can be substituted on A in formula (II). Z ₃ , Z ₄ , Y and X ₂ have the same meanings as those in formula (II), and the preferred ranges are also the same.

Among the compounds represented by the general formula (II), more preferred are the compounds represented by the general formula (II-b).

Embedded image

In the formula, A has the same meaning as that in formula (II), and the preferred range is also the same. Further, the substituent that can be substituted on A has the same meaning as the substituent that can be substituted on A in formula (II). Z ₃ , Z ₄ and X ₂ are represented by the general formula (I
It has the same meaning as those in I), and the preferred range is also the same.

Specific examples of the compound represented by the general formula (II) include specific examples II-1 to II-38 of the compound represented by the general formula (II) in JP-A-10-339934. Can be

The organic polyhalogen compound represented by the formula (1) used as an essential component in the photothermographic material of the present invention may be used in combination of two or more.
In the formula (1), Z ₁ and Z ₂ each independently represent a halogen atom (fluorine, chlorine, bromine, iodine).
Most preferably, ₁ and Z ₂ are both bromine atoms. In the formula (1), X ₁ represents a hydrogen atom or an electron-withdrawing group, and as the electron-withdrawing group, those described for X ₂ in the formula (II) can be used. Preferred electron-withdrawing groups include, for example, a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a halogen atom, an acyl group, a heterocyclic group, and a hydrogen atom. Alternatively, it is preferably a halogen atom, and most preferably a bromine atom. In the formula (1), Y ₁ represents a —CO— group or a —SO ₂ — group, but is preferably a —SO ₂ — group.

In the formula (1), Q represents an arylene group or a divalent heterocyclic group. The arylene group represented by Q in the formula (1) is preferably a monocyclic or condensed ring arylene group having 6 to 30 carbon atoms, more preferably 6 to 30 carbon atoms.
20 monocyclic or fused ring arylene group, for example,
Examples thereof include a phenylene group and a naphthylene group, and a phenylene group is particularly preferred. The arylene group represented by Q may have a substituent, and any substituent may be used as long as it does not adversely affect photographic performance. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom). Atom, bromine atom or 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, for example, morpholino group), heterocyclic group containing quaternized nitrogen atom (for example, pyridinio group), acyl group , Alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, carboxy group or a salt thereof, imino group, imino group substituted by a nitrogen atom, thiocarbonyl group, carbazoyl group, cyano group, thiocarbamoyl group, alkoxy group (ethyleneoxy group Or a group containing a propyleneoxy group unit repeatedly), an aryloxy group, a heterocyclic oxy group, an acyloxy group, (alkoxy or aryloxy)
Carbonyloxy group, sulfonyloxy group, acylamino group, sulfonamide group, ureido group, thioureido group, imide group, (alkoxy or aryloxy)
Carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, hydrazino group, 4
Grade ammonium, (alkyl or aryl) sulfonyluureido, nitro, (alkyl, aryl,
Or heterocycle) thio, acylthio, (alkyl or aryl) sulfonyl, (alkyl or aryl) sulfinyl, hydroxyl, sulfo or a salt thereof,
Examples include a sulfamoyl group, a phosphoryl group, a group having a phosphate amide or phosphate structure, and a silyl group. These substituents may be further substituted by these substituents themselves.

Particularly preferred as the substituent of the arylene group represented by Q in the formula (1) are an alkyl group, an alkoxy group, an aryloxy group, a halogen atom, a carboxyl group or a salt thereof, a salt of a sulfo group, a phosphate group. It is.

In the formula (1), the heterocyclic ring in the divalent heterocyclic group represented by Q is a 5- to 7-membered saturated or unsaturated heterocyclic ring containing at least one N, O or S atom. Yes, these may be a single ring, or may form a condensed ring with another ring. Examples of the heterocycle in the heterocyclic group represented by Q include pyridine, pyrazine, pyrimidine, benzothiazole, benzimidazole, thiadiazole, quinoline, isoquinoline, triazole and the like. These may have a substituent, and examples thereof include the same groups as the substituents of the aryl group represented by Q. Q in the formula (1) is preferably an arylene group, particularly preferably a phenylene group.
When Q represents a phenylene group, -Y ₁ -C (X ₁ ) (Z ₁ )
(Z ₂ ) and-(L) _n -CON (W ₁ ) (W ₂ ) are preferably bonded to each other at the meta position.

L in the formula (1) represents a divalent linking group, for example, an alkylene group (preferably having 1 to 30 carbon atoms,
More preferably, it has 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms. ), An arylene group (preferably having 6 to 30 carbon atoms, more preferably 6 to 30 carbon atoms)
20 and particularly preferably 6 to 10 carbon atoms. ), An alkenylene group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 20 carbon atoms, particularly preferably having 2 to 10 carbon atoms), and an alkynylene group (preferably having 2 to 30 carbon atoms). And more preferably has 2 to 20 carbon atoms, and particularly preferably has 2 to 10 carbon atoms.
It is. ) Divalent heterocyclic group (preferably having 1 to 3 carbon atoms)
0, more preferably 1 to 20 carbon atoms, particularly preferably 1 to 10 carbon atoms. ), -O- group,-
NR- group, -CO- group, -S- group, -SO- group, -SO
_{A 2} -group, a group containing a phosphorus atom, a group formed by combining them, and the like (here, the group represented by R represents a hydrogen atom or an alkyl group or a substituent which may have a substituent). An aryl group which may be present). The linking group represented by L in the formula (1) may have a substituent, and examples thereof include the same substituents as those of the arylene group represented by Q. The linking group represented by L in the formula (1) is preferably an alkylene group, an arylene group, a —O— group, a —NRCO— group, a —SO ₂ NR— group, and a group formed by combining these. In the formula (1), n is 0 or 1, and preferably 0.

In the formula (1), W ₁ and W ₂ each independently represent a hydrogen atom, an alkyl group, an aryl group or a heterocyclic group. The alkyl group represented by W ₁ and W ₂ in the formula (1) may be any of linear, branched, cyclic, or a combination thereof, and preferably has 1 to 20 carbon atoms.
More preferably, it is 1 to 12, particularly preferably 1 to 6. For example, methyl, ethyl, allyl, n-propyl, iso-propyl, n-butyl, sec-
Butyl group, iso-butyl group, n-pentyl group, sec
-Pentyl group, iso-pentyl group, 3-pentyl group,
Examples include an n-hexyl group, an n-octyl group, an n-dodecyl group, a cyclohexyl group, and the like.

The alkyl group represented by W ₁ and W ₂ in the formula (1) may have a substituent, and examples thereof include the same substituents as the arylene group represented by Q. The substituent of the alkyl group represented by W ₁ and W ₂ is
Preferably, a halogen atom, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a carbamoyl group, an alkoxy group, an aryloxy group, a sulfonamide group, an (alkyl or aryl) thio group, an (alkyl or aryl) sulfonyl group, and a sulfo group Or a salt thereof, a carboxyl group or a salt thereof, a phosphate group or a salt thereof, or a hydroxyl group, more preferably a halogen atom, an alkenyl group, an alkynyl group, an aryl group, a carbamoyl group,
An alkoxy group, an aryloxy group, an (alkyl or aryl) thio group, a sulfo group or a salt thereof, a carboxyl group or a salt thereof, or a hydroxyl group, particularly preferably a halogen atom, an alkenyl group, a carbamoyl group, an alkoxy group, an alkylthio group, It is a salt of a sulfo group, a carboxyl group or a salt thereof, or a hydroxyl group.

The aryl group represented by W ₁ and W ₂ in the formula (1) is a monocyclic or condensed-ring aryl group, preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 16 carbon atoms. 10, and examples thereof include a phenyl group and a naphthyl group, and a phenyl group is preferable. The aryl group represented by W ₁ and W ₂ may have a substituent, and examples thereof include the same substituents as those of the alkyl group represented by W ₁ and W ₂ , and the preferred range is also the same. .

The heterocyclic ring represented by W ₁ and W ₂ in the formula (1) is a heterocyclic ring containing at least one N, O or S atom.
And a 7-membered saturated or unsaturated hetero ring, which may be a single ring or may form a condensed ring with another ring. For example, pyridyl, pyrazinyl, pyrimidinyl, thiazolyl, imidazolyl, benzothiazolyl, benzimidazolyl, thiadiazolyl, quinolyl,
Isoquinolyl, triazolyl and the like. These may have a substituent, and examples thereof include the same substituents as the alkyl group represented by W ₁ and W ₂ .
The same applies to the preferred range. W ₁ and W ₂ may be the same or different, and may be bonded to each other to form a cyclic structure. W ₁ and W ₂ are preferably a hydrogen atom or an alkyl group or an aryl group, particularly preferably a hydrogen atom or an alkyl group.

Specific examples of the organic polyhalogen compound represented by the formula (1) are shown below, but the polyhalogen compound which can be used in the light-sensitive material of the present invention is not limited thereto.

[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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[0041]

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[0042]

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[0043]

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[0044]

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[0045]

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[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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The above-mentioned organic polyhalogen compound may be water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), dimethylformamide, dimethyl sulfoxide. And methylcellosolve. Further, the compound to which the acidic group is bonded may be neutralized with an equivalent amount of alkali and added as a salt.

The layer containing the organic polyhalogen compound represented by the formula (1) is preferably formed by an aqueous coating solution, and the organic polyhalogen compound represented by the formula (1) is added to the aqueous coating solution as an aqueous dispersion. It is preferably used. Any method may be adopted as the dispersion method. Well-known emulsification dispersion methods include oils such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and dissolution using an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically dispersing the emulsified dispersion. A method for producing the same is given.
Examples of the solid dispersion method include a method in which a powder of a polyhalogen compound is dispersed in a suitable solvent such as water by a ball mill, a colloid mill, or ultrasonic waves to form a solid dispersion. In this case, a protective colloid (for example, polyvinyl alcohol) and a surfactant (for example, sodium triisopropylnaphthalenesulfonate (a mixture of three isopropyl groups having different substitution positions) as anionic surfactant) may be used. . The aqueous dispersion can contain a preservative (eg, benzoisothiazolinone sodium salt). The particle size of the aqueous dispersion is preferably in the range of 0.1 to 1.0 μm, more preferably in the range of 0.15 to 0.60 μm.

The amount of the organic polyhalogen compound to be added is preferably 1 × 10 ⁻⁶ to 1 mol per mol of silver on the surface of the image forming layer.
1 mol, preferably 1 × 10 ^{−5 to} 0.5 mol, more preferably 1 × 10 ^{−3 to} 0.3 mol. In this case, silver per mole of silver means one mole per mole of the sum of silver halide and silver organic acid. The addition position of the organic polyhalogen compound may be added to the layer on the image forming layer side with respect to the support, that is, the image forming layer or any other layer on the layer side. It is preferable to add. The combined ratio of the organic polyhalogen compound other than the organic polyhalogen compound represented by the general formula (1) and the organic polyhalogen compound represented by the general formula (1) is preferably in the range of 0.01: 99.99 to 99.99: 0.01. It is particularly preferably from 5:95 to 95: 5, and more preferably from 9:91 to 91: 9.

The organic silver salt that can be used in the present invention includes:
Relatively stable to light, but in the presence of an exposed photocatalyst (such as a latent image of photosensitive silver halide) and a reducing agent,
A silver salt that forms a silver image when heated to 80 ° C. or higher. The organic silver salt can be any organic substance including a source capable of reducing silver ions. Such non-photosensitive organic silver salts are described in JP-A-10-62899, paragraphs 0048 to 0049, and EP-A-0 080 373 A1, page 18, line 24 to page 19, line 37. ing. Silver salts of organic acids, in particular silver salts of long-chain aliphatic carboxylic acids (with 10 to 30, preferably 15 to 28 carbon atoms) are preferred. Preferred examples of the organic silver salt include silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate, silver fumarate, and tartaric acid. Silver, silver linoleate, silver butyrate, silver camphorate, mixtures thereof and the like can be mentioned.

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

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

The silver salt of an organic acid used in the present invention is prepared by reacting a solution or a suspension of an alkali metal salt (including Na salt, K salt, Li salt, etc.) of the above-mentioned organic acid with silver nitrate. Is done. The alkali metal salt of an organic acid is obtained by treating the above organic acid with an alkali. The silver organic acid can be run batchwise or continuously in any suitable vessel. The stirring in the reaction vessel can be performed by any stirring method depending on the required characteristics of the particles. The silver salt of an organic acid can be prepared by adding a silver nitrate aqueous solution gradually or rapidly to a reaction vessel containing an alkali metal salt solution or suspension of an organic acid, or by preparing an organic acid prepared beforehand in a reaction vessel containing a silver nitrate aqueous solution. Preferably, a method of gradually or rapidly adding an alkali metal salt solution or suspension, and a method of simultaneously adding a previously prepared aqueous solution of silver nitrate and a solution or suspension of an organic acid alkali metal salt into a reaction vessel are preferably used. Can be.

The silver nitrate aqueous solution and the organic acid alkali metal salt solution or suspension may be of any concentration for controlling the particle size of the prepared organic acid silver, and may be added at any addition rate. it can. The silver nitrate aqueous solution and the organic acid alkali metal salt solution or suspension can be added by a method of adding at a constant addition rate, an accelerated addition method by an arbitrary time function, or a deceleration addition method. Also, the reaction solution may be added to the liquid surface,
Further, it may be added to the liquid. In the case of a method in which a previously prepared aqueous silver nitrate solution and an organic acid alkali metal salt solution or suspension are simultaneously added to the reaction vessel, either the silver nitrate aqueous solution or the organic acid alkali metal salt solution or suspension is preceded. Although it can be added, it is preferable to add the silver nitrate aqueous solution first. The amount added in advance is preferably 0 to 50% by volume of the total added amount, and 0 to 25% by volume.
Volume% is particularly preferred. Further, as described in JP-A-9-127643, a method of adding while controlling the pH or silver potential of the reaction solution during the reaction can be preferably used.

The silver nitrate aqueous solution or organic acid alkali metal salt solution or suspension to be added depends on the required characteristics of the particles.
The pH can be adjusted. Any acid or alkali can be added for pH adjustment. Further, depending on the required characteristics of the particles, for example, the temperature in the reaction vessel can be arbitrarily set in order to control the particle size of the prepared organic acid silver, but a silver nitrate aqueous solution or an organic acid alkali metal salt solution or The suspension can also be prepared at any temperature. The organic acid alkali metal salt solution or suspension is preferably heated and kept at 50 ° C. or higher in order to ensure fluidity of the solution. The silver salt of an organic acid used in the present invention is preferably prepared in the presence of a tertiary alcohol. The tertiary alcohol preferably has a total carbon number of 15 or less, particularly preferably 10 or less. Examples of preferred tertiary alcohols include tert-
Butanol and the like. The tertiary alcohol may be added at any timing during the preparation of the organic acid silver salt, but it is preferable to add the tertiary alcohol during the preparation of the organic acid alkali metal salt and dissolve the organic acid alkali metal salt before use. Also, the third
The amount of the alcohol to be used can be arbitrarily used in a weight ratio of 0.01 to 10 with respect to water as a solvent during the preparation of the organic acid silver, but is preferably in a range of 0.03 to 1.

The scaly organic silver salt preferably used in the present invention is prepared by reacting an aqueous solution containing a water-soluble silver salt with an aqueous tertiary alcohol solution containing an alkali metal salt of an organic acid in a reaction vessel (liquid in the reaction vessel). A step of adding a tertiary alcohol aqueous solution containing an organic acid alkali metal salt to the reaction vessel) (preferably, an aqueous solution containing a water-soluble silver salt previously added, or a water-soluble silver salt Is added simultaneously with the aqueous tertiary alcohol solution containing the alkali metal salt of an organic acid from the beginning without first adding water, or water or a mixed solvent of water and a tertiary alcohol, as described later. Water or a mixed solvent of water and a tertiary alcohol may be added in advance even when an aqueous solution containing a salt is added in advance.) The temperature difference between the alcohol aqueous solution 20
It is preferable to be manufactured by a method of setting the temperature to not less than 85 ° C. By maintaining such a temperature difference during the addition of the tertiary alcohol aqueous solution containing the organic acid alkali metal salt, the crystal form and the like of the organic acid silver salt are preferably controlled.

The water-soluble silver salt is preferably silver nitrate, and the concentration of the water-soluble silver salt in the aqueous solution is 0.03.
mol / l or more and 6.5 mol / l or less, more preferably 0.1 mol / l or more and 5 mol / l or less, and the pH of this aqueous solution is preferably 2 or more and 6 or less, more preferably pH 3.5 or more. 6 or less. Further, a tertiary alcohol having 4 to 6 carbon atoms may be contained, in which case the volume is 70% or less, preferably 50% or less, based on the total volume of the aqueous solution of the water-soluble silver salt. The temperature of the aqueous solution is preferably from 0 ° C to 50 ° C, more preferably from 5 ° C to 30 ° C, and as described later, an aqueous solution containing a water-soluble silver salt and an aqueous tertiary alcohol solution of an organic acid alkali metal salt. Is most preferably 5 ° C. or more and 15 ° C. or less.

The alkali metal of the organic acid alkali metal salt is
Specifically, they are Na and K. Organic acid alkali metal salts are
It is prepared by adding NaOH or KOH to an organic acid. At this time, it is preferable that the amount of the alkali is equal to or less than the amount of the organic acid to leave unreacted organic acid.
In this case, the amount of the residual organic acid is 3 per 1 mol of the total organic acid.
mol% or more and 50 mol% or less, preferably 3 m
ol% or more and 30 mol% or less. Alternatively, after the alkali is added in a desired amount or more, an acid such as nitric acid or sulfuric acid may be added to neutralize excess alkali. Further, the pH can be adjusted according to the required characteristics of the organic acid silver salt. For adjusting the pH, any acid or alkali can be used.

Further, an aqueous solution containing a water-soluble silver salt, an aqueous solution of a tertiary alcohol of an organic acid alkali metal salt, or a liquid in a reaction vessel is represented, for example, by the general formula (1) of JP-A-62-65035. Compounds such as those described in
Water-soluble group-containing N-heterocyclic compounds as described in JP-A-2-150240, inorganic peroxides as described in JP-A-50-101919, and sulfur as described in JP-A-51-78319. Compounds, disulfide compounds described in JP-A-57-643, and hydrogen peroxide can be added.

The aqueous tertiary alcohol solution of the alkali metal salt of an organic acid is preferably a mixed solvent of a tertiary alcohol having 4 to 6 carbon atoms and water in order to obtain a uniform liquid.
If the carbon number exceeds this, there is no compatibility with water, which is not preferable. Of the tertiary alcohols having 4 to 6 carbon atoms, tert-butanol, which is most compatible with water, is most preferable. Third
Alcohols other than alcohols are reducing as described above, and are undesirable because they cause adverse effects when forming organic acid silver salts. The amount of the tertiary alcohol used in combination with the aqueous tertiary alcohol solution of the organic acid alkali metal salt is 3% or more and 70% or less, preferably 5% or more as a solvent volume with respect to the volume of water in the tertiary alcohol aqueous solution. 50% or less. The concentration of the organic acid alkali metal salt in the tertiary alcohol aqueous solution of the organic acid alkali metal salt is expressed as a weight ratio,
7 to 50% by weight, preferably 7 to 45% by weight, more preferably 1 to 45% by weight.
0 to 40% by weight.

The temperature of the aqueous tertiary alcohol solution of the alkali metal salt of an organic acid to be added to the reaction vessel is at least 50 ° C. in order to keep the temperature necessary to avoid the crystallization and solidification of the alkali metal salt of the organic acid. 90 ° C or lower is preferable, more preferably 60 ° C or higher and 85 ° C or lower, and 6 ° C or lower.
The temperature is most preferably 5 ° C or more and 85 ° C or less. Further, in order to control the temperature of the reaction to be constant, it is preferable that the temperature is controlled to be constant at a certain temperature selected from the above range.
The organic acid silver salt preferably used in the present invention is a method in which i) an aqueous solution containing a water-soluble silver salt is first added to an aqueous solution in which a total amount of an aqueous tertiary alcohol of an organic acid alkali metal salt is added to an aqueous solution present in a reaction vessel, Or ii) a method in which an aqueous solution of a water-soluble silver salt and an aqueous solution of a tertiary alcohol of an organic acid alkali metal salt are simultaneously added to a reaction vessel (simultaneous addition method). In the present invention, the latter method of simultaneous addition is preferred in terms of controlling the average particle size of the organic acid silver salt and narrowing the distribution. In this case, it is preferable that 30% by volume or more of the total amount is simultaneously added, and more preferably 50 to 75% by volume is simultaneously added. When any of them is added first, it is preferable to add a solution of a water-soluble silver salt first.

In any case, the liquid in the reaction vessel (as described above, when the aqueous solution of the water-soluble silver salt previously added or the aqueous solution of the water-soluble silver salt is not previously added, is used) As described above) is preferably 5 ° C. or more and 75 ° C.
Or less, more preferably 5 ° C or more and 60 ° C or less, and most preferably 10 ° C or more and 50 ° C or less. It is preferable to control the temperature to a certain temperature selected from the above temperatures throughout the whole process of the reaction, but it is also preferable to control the temperature in several temperature patterns within the above temperature range. The temperature difference between the aqueous tertiary alcohol solution of the organic acid alkali metal salt and the liquid in the reaction vessel is preferably from 20 ° C to 85 ° C, more preferably from 30 ° C to 80 ° C. In this case, the temperature of the tertiary alcohol aqueous solution of the organic acid alkali metal salt is preferably higher.

Accordingly, the rate at which the tertiary alcohol aqueous solution of the alkali metal salt of the organic acid at a high temperature is rapidly cooled in the reaction vessel and precipitates in the form of microcrystals, and the rate at which the organic acid silver salt is converted by the reaction with the water-soluble silver salt are preferable. Thus, the crystal form, crystal size, and crystal size distribution of the organic acid silver salt can be preferably controlled. At the same time, the performance as a heat developing material, especially as a heat developing photosensitive material, can be further improved. A solvent may be contained in the reaction vessel in advance, and water is preferably used as a solvent to be put in advance, but a mixed solvent with the tertiary alcohol is also preferably used. An aqueous medium-soluble dispersing aid can be added to the aqueous tertiary alcohol solution of the organic acid alkali metal, the aqueous solution of the water-soluble silver salt, or the reaction solution. As a dispersing aid,
Any material may be used as long as the formed organic acid silver salt can be dispersed. A specific example is in accordance with the description of the organic silver salt dispersing agent described below.

In the method for preparing a silver salt of an organic acid, it is preferable to perform a desalting / dehydrating step after the formation of the silver salt. The method is not particularly limited, and known and commonly used means can be used. For example, known filtration methods such as centrifugal filtration, suction filtration, ultrafiltration, and floc-forming water washing by a coagulation method, and supernatant removal by centrifugal sedimentation are preferably used. The desalting / dehydration may be performed once or plural times. The addition and removal of water may be performed continuously or individually. In the desalination / dehydration, the conductivity of the finally dehydrated water is preferably 300 μS / cm or less, more preferably 100 μS / cm.
cm, most preferably 60 μS / cm or less. Although the lower limit of the conductivity in this case is not particularly limited, it is usually about 5 μS / cm. Further, in order to improve the coated surface condition of the photothermographic material, especially the photothermographic material, an aqueous dispersion of an organic acid silver salt is obtained, which is converted into a high-speed flow at a high pressure, and then the pressure is reduced. It is preferable to redisperse to obtain a fine water dispersion. In this case, the dispersion medium is preferably water alone, but may contain an organic solvent as long as it is 20% by weight or less.

The method of dispersing the silver salt of an organic acid in fine particles can be carried out by a known method of finely pulverizing in the presence of a dispersing aid (for example, a high-speed mixer, a homogenizer, a high-speed impact mill, a Banbury mixer, a homomixer, a kneader, a ball mill, Ball mill, planetary ball mill, attritor, sand mill,
It can be dispersed mechanically using a bead mill, colloid mill, jet mill, roller mill, tron mill, high-speed stone mill).

When a photosensitive silver salt is present at the time of dispersion, fog increases and the sensitivity is remarkably reduced. Therefore, it is more preferable that the photosensitive silver salt is not substantially contained at the time of dispersion. In the present invention, the amount of the photosensitive silver salt in the aqueous dispersion to be dispersed is:
The content is 0.1 mol% or less based on 1 mol of the organic acid silver salt in the solution, and no positive addition of the photosensitive silver salt is performed. With high S / N,
In order to obtain a uniform organic silver salt solid dispersion having a small particle size and no aggregation, it is preferable to apply a large force uniformly within a range that does not cause breakage or high temperature of the organic silver salt particles as an image forming medium. For this purpose, a dispersion method in which an aqueous dispersion comprising an organic silver salt and an aqueous solution of a dispersant is converted into a high-speed stream, and then the pressure is reduced is preferable.

For the dispersing apparatus and the technique used to carry out the above redispersion method, see, for example, “Dispersion Rheology and Dispersion Technique” (Toshio Kajiuchi, Hiroki Usui)
Author, 1991, Shinzansha Publishing Co., Ltd., p357-40
3), “Progress of Chemical Engineering Vol. 24,” edited by The Society of Chemical Engineers, Tokai Branch, 1990, Maki Shoten, p184-1
85), JP-A-59-49832, U.S. Pat.
No. 33254, JP-A-8-137044,
JP-A-8-238848, JP-A-2-26152
No. 5, JP-A-1-94933, etc.
In the redispersion method of the present invention, after the aqueous dispersion containing at least the organic acid silver salt is pressurized by a high-pressure pump or the like and sent into the pipe,
This is a method in which fine dispersion is performed by passing through a narrow slit provided in a pipe and then causing a sharp pressure drop in the dispersion.

As for the high-pressure homogenizer, generally, (a) “shearing force” generated when the dispersoid passes through a narrow gap (about 75 μm to 350 μm) at high pressure and high speed;
It is thought that the cavitation force due to the subsequent pressure drop is further increased without changing the impact force generated when liquid-liquid collision or wall collision occurs in a narrow space with high pressure, and uniform and efficient dispersion is performed. I have. An example of this type of dispersing device is a Gaulin homogenizer. The particles collide and are emulsified and dispersed by the impact force. Examples of the liquid-liquid collision include a Y-type chamber of a microfluidizer and a spherical chamber using a spherical check valve as described in Japanese Patent Application Laid-Open No. H8-103642 described below. Examples include a Z-type chamber of a microfluidizer. The working pressure is generally in the range of 100 to 600 kg / cm ² , and the flow rate is in the range of several m to 30 m / sec. Things have also been devised. As a typical example of such an apparatus, a Gorin homogenizer, a microfluidizer manufactured by Microfluidics International Corporation,
Examples include a microfluidizer manufactured by Mizuho Industry Co., Ltd. and a nanomizer manufactured by Tokushu Kika Kogyo Co., Ltd. JP
No. 8-238848, No. 8-103642, U.S. Pat.
It is also described in the specification of No. 4.

The silver salt of an organic acid can be dispersed into a desired particle size by adjusting the flow rate, the differential pressure at the time of pressure drop, and the number of times of processing. However, from the viewpoint of photographic characteristics and particle size, the flow rate is 200 m / sec. ~ 600m / sec, differential pressure at the time of pressure drop is 900 ~ 300
0 kg / cm ² is preferable, and the flow rate is 300 m / sec to 60
It is more preferable that the pressure difference at the time of the pressure drop is in the range of 1500 to 3000 kg / cm ² . The number of times of the distributed processing can be selected as needed. Usually, a range of 1 to 10 times is selected, but from the viewpoint of productivity, about 1 to 3 times is selected. It is not preferable to raise the temperature of such an aqueous dispersion under high pressure from the viewpoint of dispersibility and photographic properties.At a temperature higher than 90 ° C., the particle size tends to increase and the fog tends to increase. is there. Therefore, the step before the conversion to the high-pressure, high-speed flow, the step after the pressure is reduced, or both of these steps includes a cooling device, and the temperature of such water dispersion is 5 ° C. to 90 ° C. by the cooling step. , And more preferably in the range of 5 ° C to 80 ° C, particularly preferably in the range of 5 ° C to 65 ° C. In particular, at the time of high-pressure dispersion in the range of 1500 to 3000 kg / cm ² , it is effective to provide the above cooling step. Depending on the required heat exchange amount, the cooling device uses a static mixer for double or triple tubes, a multi-tube heat exchanger,
A coiled tube heat exchanger or the like can be appropriately selected. Also,
In order to increase the efficiency of heat exchange, it is only necessary to select a suitable one such as the thickness, thickness and material of the pipe in consideration of the working pressure. As the refrigerant used for the cooler, a refrigerant such as well water at 20 ° C., cold water at 5 to 10 ° C. treated with a refrigerator, and ethylene glycol / water at −30 ° C. as necessary are used, based on the heat exchange amount. can do.

When the organic acid silver salt is formed into fine solid particles using a dispersant, for example, polyacrylic acid, a copolymer of acrylic acid, a maleic acid copolymer, a maleic acid monoester copolymer, and acryloyl Synthetic anionic polymers such as methyl propane sulfonic acid copolymer, semi-synthetic anionic polymers such as carboxymethyl starch and carboxymethyl cellulose, anionic polymers such as alginic acid and pectic acid, JP-A-52-92716, WO 88/04794.
No. 7-350753
Or known anionic, nonionic, cationic surfactants, and other known polymers such as polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose, or natural materials such as gelatin. Can be appropriately selected and used.

It is a general method that the dispersing aid is mixed with a powder of an organic acid silver salt or an organic acid silver salt in a wet cake state before dispersion and sent to a dispersing machine as a slurry.
A heat treatment or a treatment with a solvent may be performed in a state of being mixed with the organic acid silver salt in advance to obtain an organic acid 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 mechanical dispersion, the particles may be coarsely dispersed in a solvent by controlling the pH, and then finely divided by changing the pH in the presence of a dispersing aid. At this time, an organic acid solvent may be used as a solvent used for the coarse dispersion, and the organic solvent is usually removed after completion of the fine particle formation. 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 by a hydrophilic colloid (for example, in a jelly state using gelatin). You can also.
Further, a preservative can be added for the purpose of preventing the propagation of various bacteria during storage. The organic acid silver salt prepared by the method for preparing an organic acid silver salt is preferably dispersed in an aqueous solvent, mixed with an aqueous solution of a photosensitive silver salt, and supplied as a photosensitive image forming medium coating solution. .

Prior to the dispersion operation, the raw material liquid is roughly dispersed (preliminary dispersion). As a means for coarse dispersion, known dispersion means (for example, high-speed mixer, homogenizer, high-speed impact mill, Banbury mixer, homomixer, kneader, ball mill, vibration ball mill, planetary ball mill, attritor, sand mill, bead mill, colloid mill,
Jet mill, roller mill, tron mill, high-speed stone mill) can be used. In addition to mechanical dispersion, the particles may be coarsely dispersed in a solvent by controlling the pH, and then finely divided by changing the pH in the presence of a dispersing aid. At this time, an organic solvent may be used as a solvent used for the coarse dispersion, and the organic solvent is usually removed after completion of the fine particle formation.

The aqueous solution of the photosensitive silver salt is finely dispersed and then mixed to produce a photosensitive image forming medium coating solution. When a photothermographic material is prepared using such a coating solution, a haze is low, and a low-fogging, high-sensitivity photothermographic material can be obtained. On the other hand, when converted to a high-pressure, high-speed flow and dispersed, the presence of a photosensitive silver salt causes fog to increase and the sensitivity to decrease significantly. 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 to 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 converted into a high-pressure and high-speed dispersion substantially does not contain a photosensitive silver salt, and the content thereof is based on the non-photosensitive organic silver salt. 0.
The content is 1 mol% or less, and the photosensitive silver salt is not positively added. The particle size (volume weighted average diameter) of the organic silver salt solid fine particle dispersion is determined, for example, by irradiating the solid fine particle dispersion dispersed in a liquid with a laser beam, and calculating the autocorrelation function with respect to the time change of the fluctuation of the scattered light. Can be determined from the particle size (volume weighted average diameter) obtained by the above. A solid fine particle dispersion having an average particle size of 0.05 μm or more and 10.0 μm or less is preferable. The average particle size is more preferably 0.1 μm or more and 5.0 μm or less, and still more preferably the average particle size is 0.1 μm or more and 2.0 μm or less.

The organic silver salt solid fine particle dispersion preferably used in the present invention comprises at least an organic silver salt and water. Although the ratio of the organic silver salt to water is not particularly limited, the ratio of the organic silver salt to the whole is 5 to 5%.
It is preferably 0% by weight, particularly preferably in the range of 10 to 30% by weight. Although it is preferable to use the above-mentioned dispersing aid, it is preferable to use the dispersing aid in a minimum amount within a range suitable for minimizing the particle size, and 1 to 30% by weight based on the organic silver salt,
In particular, the range of 3 to 15% by weight is preferable. In the present invention, it is possible to produce a photosensitive material by mixing the aqueous dispersion of the organic silver salt and the aqueous dispersion of the photosensitive silver salt, the mixing ratio of the organic silver salt and the photosensitive silver salt can be selected according to the purpose, The ratio of the photosensitive silver salt to the organic silver salt is preferably in the range of 1 to 30 mol%,
Further, the range is preferably 3 to 20 mol%, particularly preferably 5 to 15 mol%.
Mixing two or more aqueous dispersions of organic silver salts with two or more aqueous dispersions of photosensitive silver salts during mixing is a method preferably used for adjusting photographic characteristics. In the present invention, the organic silver salt can be used in a desired amount, but the silver amount is 0.1 to 5 g /
m ^2, more preferably an 1 to 3 g / m ^2.

The photothermographic material of the present invention contains a reducing agent for silver ions. A reducing agent for silver ions is any substance (preferably an organic substance) that reduces silver ions to metallic silver.
It may be. Such reducing agents are described in paragraphs 0043 to 0045 of JP-A-11-65021 and European Patent Publication No.
0803764A1 page 7, line 34 to page 18, page 1
It is described in two lines. In the present invention, bisphenol reducing agents (for example, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane) are particularly preferred. The amount of the reducing agent added is 0.01 to 5.
Is preferably 0 g / m ^2, more preferably from 0.1 to 3.0 g / m ^2, preferably contained 5-50% mol per mol of silver on the side having the image forming layer, 10 ~Four
More preferably, it is contained at 0 mol%. The reducing agent is preferably contained in the image forming layer.

In the present invention, the reducing agent is preferably added as 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. In the present invention, a super-high contrast agent may be used in order to obtain a super-high contrast image for use in a plate making film. Examples of the super-high contrast agent include compounds represented by general formulas (III) to (V) described in Japanese Patent Application No. 11-91652.
Chemical formula 24 can be used, but is not limited thereto.

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

Methods of forming light-sensitive silver halide are well known in the art, for example, Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,45.
The method described in No. 8 can be used, but specifically, a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to gelatin or another polymer solution, Thereafter, a method of mixing with an organic silver salt is used.

The grain size of the photosensitive silver halide is 0.00
1 μm or more and 0.06 μm or less, preferably 0.01 μm or more and 0.05 μm or less, more preferably 0.02 μm or more and 0.04 μm
The following is good. The grain size as used herein means that when the silver halide grains are cubic or octahedral so-called normal crystals, and when they are not normal crystals, for example, in the case of spherical grains, rod-like grains, etc., the volume of the silver halide grains is It refers to the diameter when considering equivalent spheres, and when the silver halide grains are tabular grains, it refers to the diameter when converted into a circular image having the same area as the projected area of the main surface.

The shape of the silver halide grains is cubic,
Octahedral, tabular particles, spherical particles, rod-like particles, potato-like particles and the like can be mentioned. In the present invention, cubic particles are particularly preferable. Grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grains is not particularly limited, but the ratio of the [100] plane, which has high spectral sensitization efficiency when a spectral sensitizing dye is adsorbed, is high. preferable. The ratio is preferably 50% or more,
It is more preferably at least 65%, even more preferably at least 80%. Miller index [100] plane ratio is [111] in the adsorption of sensitizing dye
T.Tani; J.Imagin using the adsorption dependence of the [100] plane
g Sci., 29, 165 (1985).

The photosensitive silver halide grains contain a metal or metal complex of Group 8 to Group 10 of the periodic table (showing Groups 1 to 18). Rhodium, rhenium, ruthenium, osmium and iridium are preferred as the metals of Groups 8 to 10 of the periodic table or the central metal of the metal complex. One kind of these metal complexes may be used, or two or more kinds of complexes of the same metal and different metals may be used in combination. The preferred content is in the range of 1 × 10 ^-9 mol to 1 × 10 ^-3 mol per mol of silver. These metal complexes are disclosed in
No. 11-65021, paragraphs 0018 to 0024.

In the present invention, among them, it is preferable to include an iridium compound in silver halide grains. Examples of the iridium compound include hexachloroiridium, hexaammineiridium, trioxalatoiridium, hexacyanoiridium, and pentachloronitrosyliridium. These iridium compounds are used after being dissolved in water or an appropriate solvent. However, a method generally used to stabilize the solution of the iridium compound, that is, an aqueous solution of hydrogen halide (for example, hydrochloric acid, hydrobromic acid, hydrofluoric acid) is used. Etc.) or a method of adding an alkali halide (eg, KCl, NaCl, KBr, NaBr, etc.). Instead of using water-soluble iridium, it is also possible to add and dissolve another silver halide grain doped with iridium in advance during the preparation of silver halide. The addition amount of these iridium compounds is 1 × 10 ⁻⁸ mol / mol of silver halide.
The range of 1 × 10 ^-3 mol is preferable, and 1 × 10 ^-7 mol to 5 mol
A range of × 10 ^-4 mol is more preferred. Further, regarding the metal atoms (for example, [Fe (CN) ₆ ] ^4- ) which can be contained in the silver halide grains used in the present invention, desalting and chemical sensitization, JP-A-11-84574, paragraph No. 0046 to 0050, paragraphs 0025 to 0031 of JP-A-11-65021.

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

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

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

In the present invention, the image forming layer is preferably formed with an aqueous coating solution. For example, as the aqueous coating liquid, a coating liquid in which 30% by weight or more of the solvent is water can be used, and after the application, it can be dried to form an image forming layer. In this case, it is preferable that the binder of the image forming layer is further contained in a soluble or dispersed state in an aqueous coating solution (aqueous solvent). In particular, the equilibrium water content at 25 ° C and 60% RH
It is preferable to use a polymer latex of 2% by weight or less. The most preferred form has an ionic conductivity of 2.5 mS / cm
It is prepared as follows. As such a preparation method, a method of purifying using a separation functional membrane after polymer synthesis can be mentioned.

The aqueous coating solution in which the polymer is soluble or dispersible as described herein is a solvent in which water or water is mixed with 70% by weight or less of a water-miscible organic solvent.
Examples of the water-miscible organic solvent include alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol; cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; ethyl acetate; and dimethylformamide. Note that the term “aqueous solvent” is used herein even in a system in which the polymer is not thermodynamically dissolved but exists in a so-called dispersed state. The “equilibrium water content at 25 ° C and 60% RH” refers to the weight W1 of a polymer that is in a moisture-conditioning equilibrium in an atmosphere of 25 ° C and 60% RH and the weight W0 of a polymer that is in an absolutely dry state at 25 ° C. Can be expressed as Equilibrium water content at 25 ° C and 60% RH = [(W1-W0) / W0] x 100 (% by weight)

The definition and measurement method of the water content are described in, for example, Polymer Engineering Course 14, Polymer Material Testing Method (Polymer Society,
You can refer to Citizen Library). The equilibrium water content at 25 ° C. and 60% RH of the binder polymer in the present invention is
It is preferably at most 2% by weight, more preferably
0.01% by weight or more and 1.5% by weight or less, more preferably 0.02% by weight
It is desirable that the content be not less than 1% by weight and not more than 1% by weight. In the present invention, a polymer dispersible in an aqueous solvent is particularly preferred. Examples of the dispersion state include a latex in which fine particles of a solid polymer are dispersed, and a dispersion in which polymer molecules are dispersed in a molecular state or in the form of micelles, all of which are preferable.

In a preferred embodiment of the present invention, acrylic resin, polyester resin, rubber resin (for example, SBR
Resin), a polyurethane resin, a vinyl chloride resin, a vinyl acetate resin, a vinylidene chloride resin, a hydrophobic polymer such as a polyolefin resin. The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. The polymer has a number average molecular weight of 5000 to 100000, preferably 10,000 to 200,000. If the molecular weight is too small, the mechanical strength of the emulsion layer is insufficient, and if it is too large, the film-forming properties are poor, which is not preferable.

The “aqueous solvent” refers to a dispersion medium in which 30% by weight or more of the composition is water. The dispersion state may be any state such as emulsified dispersion, micelle dispersed, and further dispersed in a molecular state a polymer having a hydrophilic site in the molecule, but among these, latex is particularly preferred. . Specific examples of the preferred polymer latex include the following. In the following, the raw material monomers are used, the numerical value in parentheses is% by weight, and the molecular weight is the number average molecular weight. P-1; -MMA (70) -EA (27) -MAA (3)-latex (molecular weight 3700
0) Latex of P-2; -MMA (70) -2EHA (20) -St (5) -AA (5)-(molecular weight 40000) P-3; -St (50) -Bu (47) -MAA ( 3)-latex (molecular weight 4500
0) P-4; -St (68) -Bu (29) -AA (3)-latex (MW 60000) P-5; -St (70) -Bu (27) -IA (3)-latex (Molecular weight 12000
0) Latex of P-6; -St (75) -Bu (24) -AA (1)-(molecular weight 10800
0) P-7; -St (60) -Bu (35) -DVB (3) -MAA (2)-latex (molecular weight 150,000) P-8; -St (70) -Bu (25) -DVB ( 2) -AA (3)-latex (molecular weight 280000) P-9; -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-latex (molecular weight 80000) P-10; -VDC (85) -MMA (5) -EA (5) -MAA (5)-latex (molecular weight 67,000) P-11; -Et (90) -MAA (10)-latex (molecular weight) 12000) P-12; -St (70) -2EHA (27) -AA (3) latex (molecular weight 130
000) P-13; -MMA (63) -EA (35)-AA (2) latex (molecular weight 330
The abbreviations of the above structures represent the following monomers. MMA; Methyl methacrylate, EA; Ethyl acrylate, MAA; Methacrylic acid, 2EHA; 2-Ethylhexyl acrylate, S
t; styrene, Bu; butadiene, AA; acrylic acid, DVB;
Divinylbenzene, VC; vinyl chloride, AN; acrylonitrile, VDC; vinylidene chloride, Et; ethylene, IA; itaconic acid.

The polymer latexes described above are also commercially available, and the following polymers can be used. Examples of acrylic resin include Sebian A-4635,46583,4601
(Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 82
Examples of polyester resins such as 1,820,857 (all manufactured by Zeon Corporation) include FINETEX ES650, 611, 675, 850
HYDRAN AP10, 20, 30, and 40 (Dai Nippon Ink Chemical Co., Ltd.) For example, LACSTAR 731
0K, 3307B, 4700H, 7132C (Dai Nippon Ink Chemical Co., Ltd.)
Nipol Lx416, 410, 438C, 2507 (Nippon Zeon Co., Ltd.)
Examples of vinyl chloride resins include G351 and G576 (all manufactured by Nippon Zeon Co., Ltd.), and examples of vinylidene chloride resins include L502 and L513 (all manufactured by Asahi Kasei Corporation). Examples thereof include Chemipearl S120 and SA100 (all manufactured by Mitsui Petrochemical Co., Ltd.). These polymer latexes may be used alone or as a blend of two or more as necessary.

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

The organic silver salt-containing layer of the photothermographic material of the present invention may optionally contain a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose and hydroxypropylcellulose. The amount of the hydrophilic polymer to be added is preferably 30% by weight or less, more preferably 20% by weight or less of the total binder in the organic silver salt-containing layer. The organic silver salt-containing layer (that is, image forming layer) of the photothermographic material of the invention is preferably formed using a polymer latex. The amount of the binder in the organic silver salt-containing layer is such that the weight ratio of the total binder / organic silver salt is 1/1 to 10/1, and further 1/5 to
A range of 4/1 is preferred.

The organic silver salt-containing layer is usually also an image forming layer (emulsion layer) containing a photosensitive silver halide which is a photosensitive silver salt. The weight ratio of silver / silver halide is preferably in the range of 400 to 5, more preferably in the range of 200 to 10. The total amount of binder in the image forming layer of the photothermographic material of the present invention is 0.2 to 30 g / m ^2, more preferably in the range of 1 to 15 g / m ^2. A crosslinking agent for crosslinking and a surfactant for improving coating properties may be added to the image forming layer.

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

The sensitizing dye applicable to the present invention is a sensitizing dye capable of spectrally sensitizing silver halide grains in a desired wavelength region when adsorbed on the silver halide grains. The sensitizing dye to be used can be advantageously selected. For sensitizing dyes and addition methods, see
-65021, paragraphs 0103 to 0109, JP-A-10-186572
Compound represented by general formula (II), European Patent Publication No. 08
03764A1 Page 19 Line 38 to Page 20 Third
It is described on line 5. In the present invention, the time when the sensitizing dye is added to the silver halide emulsion is preferably after the desalting step and before coating, and more preferably after desalting and before the start of chemical ripening.

The antifoggants, stabilizers and stabilizer precursors which can be used in the present invention are described in JP-A-10-628.
No. 99, paragraph 0070, EP-A-0 080 364 A
No. 1, page 20, line 57 to page 21, line 7 include the patents.

In the present invention, the antifoggant is preferably added as 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 such as an anionic surfactant (for example, sodium triisopropylnaphthalenesulfonate (a mixture of three isopropyl groups having different substitution positions)) may be used. As the agent, JP-A-11-6
The mercury (II) salt of Paragraph No. 0113 of JP-A-5021 and the benzoic acid of Paragraph No. 0114 of JP-A No. 5021 are mentioned.

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

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

In the present invention, it is preferable to add a toning agent.
4-0055, EP-A-0 080 376 A1, page 21, lines 23 to 48, especially phthalazinone, phthalazinone derivatives or metal salts, 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 (eg, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride) And phthalazines (phthalazine, phthalazine derivative or metal salt, or 4- (1-naphthyl) phthalazine, 6-isopropylphthalazine, 6-t-butylfuratazine, 6-chlorophthalazine, 5,7-dimethoxy Phthalazines and derivatives such as 2,3-dihydrophthalazine); phthalazines and phthalic acid derivatives (eg, phthalic acid, 4-methylphthalic acid, 4-
(Nitrophthalic acid and tetrachlorophthalic anhydride, etc.)
Is preferred, and particularly preferred is a combination of phthalazines and phthalic acid derivatives. For the plasticizers and lubricants that can be used in the image forming layer of the photothermographic material of the present invention, refer to JP-A-11-65021, paragraph No. 0117. Paragraph number 01
18. The contrast enhancement agent is described in paragraph number 0102 of the same publication.

The photothermographic material according to the invention may be provided with a surface protective layer for the purpose of preventing adhesion of the image forming layer. The surface protective layer is described in paragraphs 0119 to 0120 of JP-A-11-65021. Gelatin is preferred as the binder for the surface protective layer of the photothermographic material of the present invention, but polyvinyl alcohol (PVA) is also preferred. As PVA, fully saponified PVA-
105 [polyvinyl alcohol (PVA) content 94.
0 wt% or more, saponification degree 98.5 ± 0.5 mol%, sodium acetate content 1.5 wt% or less, volatile matter 5.0 wt% or less, viscosity (4 wt%, 20 ° C.) 5.6 ± 0.4CP
S], partially saponified PVA-205 [PVA content 9
4.0% by weight, saponification degree 88.0 ± 1.5 mol%, sodium acetate content 1.0% by weight, volatile matter 5.0% by weight,
Viscosity (4% by weight, 20 ° C.) 5.0 ± 0.4 CPS], modified polyvinyl alcohol MP-102, MP-20
2, MP-203, R-1130, and R-2105 (all of which are trade names manufactured by Kuraray Co., Ltd.). Preferably 0.3 to 4.0 g / m ² as a coating amount of polyvinyl alcohol protective layer (per one layer) (per support 1 m ^2), 0.3
~2.0g / m ² is more preferable.

The preparation temperature of the coating solution for the image forming layer used in the present invention is preferably from 30 ° C. to 65 ° C., and more preferably 35 ° C.
C. or more and less than 60.degree. C., more preferably 35 to 55.degree. The temperature of the coating solution for the image forming layer immediately after the addition of the polymer latex is preferably maintained at 30 ° C. or more and 65 ° C. or less. Preferably, the reducing agent and the organic silver salt are mixed before the addition of the polymer latex. The fluid containing an organic silver salt or the coating solution for the thermal image forming layer in the present invention is preferably a so-called thixotropic fluid. The thixotropic property refers to a property in which the viscosity decreases as the shear rate increases. Any device may be used for the viscosity measurement, but RF by Rheometrics Far East Co., Ltd.
S fluid spectrometer is preferably used at 25 ° C
Is measured. Here, the viscosity of the organic silver salt-containing fluid or the thermal image forming layer coating solution of the present invention at a shear rate of 0.1 S ^-1 is preferably from 400 mPas to 100,000 mPas,
More preferably, it is 500 mPa · s or more and 20,000 mPa · s or less. In addition, at a shear rate of 1000 S ^{-1 and 1} mPas or more 200 m
Pa · s or less is preferable, and more preferably 5 mPa
mPa · s or less.

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

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

Various dyes and pigments can be used in the image forming layer of the photothermographic material of the present invention from the viewpoints of improving color tone, preventing interference fringes during laser exposure, and preventing irradiation. These are described in detail in WO 98/36322. Preferred dyes and pigments used in the image forming layer are anthraquinone dyes, azomethine dyes, indoaniline dyes, azo dyes, anthraquinone-based indanthrone pigments (such as CI Pigment Blue 60), phthalocyanine pigments (such as copper phthalocyanine such as CI Pigment Blue 15;
Metal-free phthalocyanine such as CI Pigment Blue 16), triarylcarbonyl pigments based on dyeing lake pigments, indigo, and inorganic pigments (ultramarine, cobalt blue, etc.). As a method for adding these dyes and pigments, any method such as a solution, an emulsion, a solid fine particle dispersion, or a state in which the dye or pigment is mordanted with a polymer mordant may be used. The amount of these compounds to be used is determined depending on the desired absorption amount, but it is generally preferable to use them in an amount of 1 μg or more and 1 g or less per 1 m ² of the photographic material.

In the present invention, the antihalation layer can be provided farther from the light source than the image forming layer. The antihalation layer is described in JP-A-11-65021, paragraphs 0123 to 0124. In the present invention, it is preferable that a decolorizing dye and a base precursor are added to the non-image forming layer (non-photosensitive layer) of the photothermographic material so that the non-image forming layer functions as a filter layer or an antihalation layer. A photothermographic material generally has a non-image forming layer in addition to an image forming layer. The non-image forming layer is arranged such that (1) a protective layer provided on the image forming layer (on the side farther from the support), (2) between a plurality of image forming layers or between the image forming layers and the protective layer. An intermediate layer provided in (3)
An undercoat layer provided between the image forming layer and the support,
(4) It can be classified into a back layer provided on the opposite side of the image forming layer. The filter layer is provided on the photosensitive material as the layer (1) or (2). The antihalation layer
It is provided on the photosensitive material as the layer (3) or (4).
The decolorizable dye and the base precursor are preferably added to the same non-image forming layer. However, they may be separately added to two adjacent non-image forming layers. Further, a barrier layer may be provided between the two non-image forming layers.

As a method of adding the decolorizable dye to the non-image forming layer, a method of adding a solution, an emulsion, a solid fine particle dispersion or a polymer impregnated material to the coating solution for the non-image forming layer can be adopted. Further, a dye may be added to the non-image forming layer using a polymer mordant. These addition methods are the same as the method of adding a dye to an ordinary photothermographic material. Latexes used in polymer impregnated products are described in US Pat.
No. 4,254,230, European Patent Publication 029104
And JP-B-53-41091. Regarding an emulsification method in which a dye is added to a solution in which a polymer is dissolved, International Publication No. 88/007
No. 23 has description. The amount of the decolorizable dye is determined depending on the use of the dye. Generally, the optical density (absorbance) measured at the target wavelength is used in an amount exceeding 0.1. The optical density is preferably from 0.2 to 2.
The amount of the dye used to obtain such an optical density is generally about 0.001 to 1 g / m ² . Preferably, 0.005-0.
About 8 g / m ² , particularly preferably 0.01 to 0.2 g / m ²
It is about. When the dye is decolored in this manner, the optical density can be reduced to 0.1 or less. Two or more decolorizable dyes may be used in combination in a heat-decolorable recording material or a photothermographic material. Similarly, two or more base precursors may be used in combination.

The photothermographic material of the present invention is a so-called one-sided light-sensitive material having at least one image forming layer containing a silver halide emulsion on one side of a support and a back layer on the other side. Preferably, there is. In the present invention, it is preferable to add a matting agent to improve the transportability, and the matting agent is described in JP-A-11-65021, paragraphs 0126 to 0127. The matting agent is preferably 1 to 400 mg when expressed in the amount applied per 1 m ² of the photosensitive material.
/ m ² , more preferably 5 to 300 mg / m ² . Also, the matte degree of the emulsion surface may be anything as long as stardust failure does not occur, but the Beck smoothness is preferably 50 seconds or more and 10,000 seconds or less,
In particular, the period is preferably from 80 seconds to 10,000 seconds. In the present invention, the matte degree of the back layer is Beck smoothness of 1200 seconds or less.
10 seconds or more is preferable, 700 seconds or less and 30 seconds or more are preferable,
More preferably, the time is 500 seconds or less and 50 seconds or more. In the present invention, the matting agent is preferably contained in the layer functioning as the outermost surface layer or the outermost surface layer of the light-sensitive material, or a layer close to the outer surface, and is contained in a layer acting as a so-called protective layer. Is preferred. The back layer applicable to the invention is described in JP-A-11-65021, paragraphs 0128 to 0130.

A hardening agent may be used in each layer such as the image forming layer, the protective layer and the back layer of the photothermographic material of the present invention. Examples of hardeners include “THE THEORY OF THE PHO” by THJames.
TOGRAPHIC PROCESS FOURTH EDITION ”(Macmillan Publi
shing Co., Inc., published in 1977) There are various methods described on pages 77 to 87, polyvalent metal ions described on page 78 of the same book, U.S. Pat.No. 4,281,060, JP-A-6-208193, etc. Polyisocyanates, epoxy compounds such as US Pat. No. 4,791,042, and vinyl sulfone compounds such as JP-A No. 62-89048 are preferably used.

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

For the surfactant which can be used in the present invention, paragraph No. 0132 of JP-A-11-65021, for solvent, paragraph No. 0133 of the same publication, for the support, paragraph No. 0134 of the same publication, antistatic Alternatively, the conductive layer is described in paragraph No. 0135 of the same publication, and the method of obtaining a color image is described in paragraph No. 0136 of the same publication. The transparent support may be colored with a blue dye (for example, Dye-1 described in Examples of JP-A-8-240877) or may be uncolored. Japanese Unexamined Patent Application Publication No. 11-84574,
No. 10-186565. The photothermographic material is preferably a mono-sheet type (a type capable of forming an image on the photothermographic material without using another sheet such as an image receiving material). The photothermographic material may further contain an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber or a coating aid. Various additives are added to either the image forming layer or the non-image forming layer. For those, WO98 / 36322, EP803764A1, JP-A-10-186567, JP-A-10-18568 and the like can be referred to.

The photothermographic material of the present invention may be applied by any method. Specifically, extrusion coating, slide coating, curtain coating, dip coating, knife coating,
Various coating operations are used, including flow coating, or extrusion coating using a hopper of the type described in U.S. Patent No. 2,681,294.
F. Kistler, Peter M. Schweizer, “LIQUID FILM COA
Extrusion coating or slide coating described on pages 399 to 536 of TING ”(published by CHAPMAN & HALL, 1997) is preferably used, and particularly preferably slide coating is used. For example, see page 427, F
igure 11b.1. Also, if desired, pages 399 to 53 of the same book.
Two or more layers can be coated simultaneously by the method described on page 6, the method described in US Pat. No. 2,761,791 and British Patent No. 837,095.

Techniques which can be used for the photothermographic material of the present invention include EP803764A1, EP883022A1, WO98
/ 36322, JP-A-9-281637, JP-A-9-297367,
No. 9-304869, No. 9-311405, No. 9-329865, No. 10-10669, No. 10-62899, No. 10-69023
No. 10-186568, No. 10-90823, No. 10-
No. 171063, No. 10-186565, No. 10-186567, No. 10-186569, No. 10-186570, No. 10-186
No. 571, No. 10-186572, No. 10-197974,
No. 10-197982, No. 10-197983, No. 10-197985
No. 10-197986, No. 10-197987, No. 10
-207001, 10-207004, 10-221807, 10-282601, 10-288823, 10-288
No. 824, No. 10-307365, No. 10-312038,
No. 10-339934, No. 11-7100, No. 11-15105, No. 11-24200, No. 11-24201, No. 11-30832.
And JP-A-11-84574 and JP-A-11-65021.

Although the photothermographic material of the present invention may be developed by any method, it is usually developed by raising the temperature of the photothermographic material exposed imagewise. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 140 ° C.
° C. The development time is preferably 1 to 180 seconds, and 10 to 180 seconds.
90 seconds is more preferable, and 10 to 40 seconds is particularly preferable. As a method of thermal development, a plate heater method is preferable. Japanese Patent Application Laid-Open No.
A method described in JP-A-1-135772 is preferable, which is a heat developing apparatus that obtains a visible image by bringing a photothermographic material having a latent image formed thereon into contact with a heating means in a heat developing section,
The heating means comprises a plate heater, and a plurality of pressing rollers are disposed facing each other along one surface of the plate heater, and the photothermographic material is passed between the pressing roller and the plate heater. A thermal developing device for performing thermal development. Plate heater 2
It is preferable to lower the temperature by about 1 ° C. to 10 ° C. at the tip portion in six stages. Such a method is also described in Japanese Patent Application Laid-Open No. 54-30032, in which water and organic solvents contained in the photothermographic material can be excluded from the system. Changes in the shape of the support of the photothermographic material due to the heating of the material can also be suppressed.

The photothermographic material of the present invention may be exposed by any method, but a laser beam is preferred as an exposure light source. As the laser beam according to the present invention, a gas laser
(Ar ⁺ , He-Ne), a YAG laser, a dye laser, a semiconductor laser and the like are preferable. Further, a semiconductor laser and a second harmonic generation element can be used. Preferably, a gas or semiconductor laser emitting red to infrared light is used. As a laser beam, a single mode laser can be used, but a technique described in paragraph No. 0140 of JP-A-11-65021 can be used. The laser output is preferably 1 mW or more, more preferably 10 mW or more, and even more preferably 40 mW or more. At that time, a plurality of lasers may be combined. The diameter of the laser beam can be about 30 to 200 μm in 1 / e ² spot size of the Gaussian beam.

The photothermographic material of the present invention forms a black-and-white image by a silver image, and is used for medical diagnosis, photothermographic material for industrial photography, photothermographic material for printing, COM
Is preferably used as a photothermographic material.
In these uses, based on the formed black-and-white image, a duplicate image is formed on a duplication film MI-Dup manufactured by Fuji Photo Film Co., Ltd. for medical diagnostics, or Fuji Photo Film Co., Ltd. ) Return film DO-175, PDO-1
Needless to say, it can be used as a mask for forming an image on 00 or an offset printing plate.

[0125]

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

<Production Example 1> Synthesis of Exemplified Compound (P-69) (1) Synthesis of Intermediate (B) 93 g of easily available compound (A), 43 g of sodium hydroxide, 123 g of sodium chloroacetate and iodide 10 g of potassium was dissolved in 300 ml of water and stirred at 80 ° C. for 2 hours. After lowering the internal temperature to 30 ° C, concentrated hydrochloric acid 50m
l was added and stirred for a while to precipitate crystals. The crystals were suction-filtered and dried to obtain 50 g of an intermediate (B) as white crystals. (2) Synthesis of Intermediate (C) 33 ml of bromine was added dropwise at room temperature to a solution of 57 g of sodium hydroxide in 500 ml of water, and then 24 g of intermediate (B) and 8 g of sodium hydroxide were added to 100 m of water
1 was added dropwise at room temperature. The precipitated crystals were filtered, and the obtained crystals were added to dilute hydrochloric acid, stirred, and filtered. By sufficiently washing with water and drying, 30 g of the intermediate (C) was obtained as white crystals.

(3) Synthesis of Intermediate (D) 30 g of the intermediate (C) and 1 ml of DMF were dissolved in 100 ml of thionyl chloride and stirred at 70 ° C. for 30 minutes. Thereafter, excess thionyl chloride was distilled off under reduced pressure to obtain 31 g of an intermediate (D) as white crystals. (4) Synthesis of Exemplified Compound (P-69) A solution of 8.0 g of octylamine dissolved in 50 ml of methanol was ice-cooled, and 4.0 g of the intermediate (D) was added. After stirring at room temperature for 10 minutes, 50 ml of diluted hydrochloric acid was added,
White crystals precipitated. This was filtered, sufficiently washed with water, and dried to give the exemplified compound (P-6) as white crystals.
3.0 g was obtained. Yield 62%.

<Production Example 2> Synthesis of Exemplified Compound (P-24) The same procedure as in Production Example 1 was repeated except that octylamine was replaced with an equimolar butylamine to give 3.5 parts of Exemplified Compound (P-24) as white crystals. g obtained. Yield 81%.

<Production Example 3> Synthesis of Exemplified Compound (P-27) 15 g of 4-aminobutanoic acid and sodium hydrogen carbonate 1
7 g of water 100 ml and tetrahydrofuran 100
20 g of the intermediate (D) was added to a solution of the intermediate (D)
Was added and stirred at room temperature for 5 minutes. After neutralizing the reaction solution by adding dilute hydrochloric acid, 200 ml of water was added, and the precipitated crystals were filtered and dried. Exemplary compound (P-2) as white crystals
7) was obtained in an amount of 10 g. Yield 44%.

<Production Example 4> Synthesis of Exemplified Compound (P-12) Except that 4-aminobutanoic acid was replaced with an equimolar glycine, Exemplified Compound (P-12) was obtained as white crystals by the same method as in Production Example 3. 13 g was obtained. Yield 60%.

<Production Example 5> Synthesis of Exemplified Compound (P-35) A white crystal of an exemplified compound (P-35) was prepared in the same manner as in Production Example 1 except that octylamine was replaced with an equimolar 6-amino-1-hexanol. 3.7 g of P-35) were obtained. 79% yield.

<Production Example 6> Synthesis of Exemplified Compound (P-64) A white crystalline Exemplified Compound (P-64) was prepared in the same manner as in Production Example 1 except that octylamine was replaced with an equimolar pentylamine. 3.7 g were obtained. Yield 84%.

<Production Example 7> Synthesis of Exemplified Compound (P-70) Exemplified compound (P-70) was obtained as white crystals in the same manner as in Production Example 1 except that octylamine was replaced with equimolar diethylamine. g obtained. 70% yield.

[0134]

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<Examples> Production of photothermographic materials (Preparation of PET support) Terephthalic acid and ethylene glycol
Of intrinsic viscosity IV = 0.66 (measured in phenol / tetrachloroethane = 6/4 (weight ratio) at 25 ° C.) according to a conventional method.
I got After pelletizing this, dried at 130 ° C for 4 hours,
After being melted at 300 ° C., it was extruded from a T-die and rapidly cooled to prepare an unstretched film having a thickness of 175 μm after heat setting. This was longitudinally stretched 3.3 times using rolls having different peripheral speeds, and then horizontally stretched 4.5 times using a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively.
Then, after heat-setting at 240 ° C. for 20 seconds, it was relaxed by 4% in the lateral direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling was performed on both ends and wound at 4 kg / cm ² to obtain a roll having a thickness of 175 μm. (Surface Corona Treatment) Using a solid state corona treatment machine 6KVA model manufactured by Pillar Co., both surfaces of the support were treated at room temperature at 20 m / min. From the current and voltage readings at this time, it was found that the support was treated at 0.375 kV · A · min / m ² . At this time, the processing frequency was 9.6 kHz, and the gap clearance between the electrode and the dielectric roll was 1.6 mm.

(Preparation of Undercoating Support) (1) Preparation of Coating Solution for Undercoating Layer Formulation 1 (for undercoating layer on the image forming layer side) Pesresin A-515GB manufactured by Takamatsu Oil & Fat Co., Ltd. (30% by weight solution) 234 g Polyethylene glycol Monononyl phenyl ether (average ethylene oxide number = 8.5) 10% by weight solution 21.5 g Soken Chemical Co., Ltd. MP-1000 (polymer fine particles, average particle diameter 0.4 μm) 0.91 g distilled water 744 ml

Formulation 2 (for the first layer on the back surface) Butadiene-styrene copolymer latex 158 g (solids content 40% by weight, butadiene / styrene weight ratio = 32/68) 2,4-dichloro-6-hydroxy-S- 1 wt% aqueous solution 10ml distilled water 854ml formulation triazine sodium salt 8 wt% aqueous solution of 20g of sodium lauryl benzene sulfonate 3 (for back surface-side second layer) SnO ₂ / SbO (9/1 weight ratio, mean particle size 0.038Myuemu, 84g Gelatin (10% aqueous solution) 89.2g Shin-Etsu Chemical Metrolose TC-5 (2% aqueous solution) 8.6g Soken Chemical Co., Ltd. MP-1000 (polymer fine particles) 0.01g Dodecylbenzene sulfone 1 wt% aqueous solution of sodium acidate 10 ml NaOH (1%) 6 ml Proxel (manufactured by ICI) 1 ml distilled water 805 ml

(Preparation of Undercoating Support) Thickness 175 μm
After performing the above-described corona discharge treatment on both surfaces of the biaxially stretched polyethylene terephthalate support, the undercoating coating liquid formulation 1 was coated on one side (image forming layer side) with a wire bar at a wet application amount of 6.6 ml / m ² (per side). ) And dried at 180 ° C. for 5 minutes. Then, the undercoating coating liquid formulation 2 was applied to the back surface (back surface) with a wire bar so that the wet application amount was 5.7 ml / m ² , and 180 At 5 ° C. for 5 minutes, and further apply undercoat coating formulation 3 on the back surface (back surface) with a wire bar so that the wet coating amount is 7.7 ml / m ^2, and then dry at 180 ° C. for 6 minutes to prepare an undercoat support. It was created.

(Preparation of Back Surface Coating Solution) (Preparation of Solid Precursor Dispersion (a) of Base Precursor) 64 g of base precursor compound 11, 28 g of diphenylsulfone and a surfactant (Demol N, manufactured by Kao Corporation) Ten
g was mixed with 220 ml of distilled water, and the mixture was dispersed in beads using a sand mill (manufactured by Imex Co., Ltd., 1/4 Gallon sand grinder mill) to obtain a dispersion of solid fine particles of a base precursor compound having an average particle diameter of 0.2 μm. (a) was obtained. (Preparation of Dye Solid Particle Dispersion) Cyanine Dye Compound 13
And 5.8 g of sodium p-dodecylbenzenesulfonate were mixed with 305 ml of distilled water. 0.2 μm
To obtain a dispersion of fine solid dye particles.

(Preparation of anti-halation layer coating solution) Gelatin 17 g, polyacrylamide 9.6 g, solid fine particle dispersion (a) of the above-mentioned base precursor 70 g, dye solid fine particle dispersion 56 g, polymethyl methacrylate fine particles (average particle size 6.5) μm) 1.5 g, benzoisothiazolinone 0.03 g,
2.2 g of sodium polyethylene sulfonate, 0.2 g of blue dye compound 14 and 844 ml of water were mixed to prepare an antihalation layer coating solution. (Preparation of back surface protective layer coating solution) Keep container at 40 ° C,
Gelatin 50g, polystyrene sodium sulfonate 0.2
g, N, N-ethylenebis (vinylsulfoneacetamide)
2.4 g, sodium t-octylphenoxyethoxyethanesulfonate 1 g, benzoisothiazolinone 30 mg, N-perfluorooctylsulfonyl-N-propylalanine potassium salt 37 mg, polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl- 2-aminoethyl) ether [average degree of polymerization of ethylene oxide 15] 0.15
g, C ₈ F ₁₇ SO ₃ K 32 mg, C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) (CH ₂ CH ₂ O) ₄ (CH ₂ ) ₄
SO ₃ Na 64 mg, acrylic acid / ethyl acrylate copolymer (copolymer weight ratio 5/95) 8.8 g, aerosol OT (manufactured by American Cyanamid Co.) 0.6 g, liquid paraffin emulsion 1.8 g as liquid paraffin, 950 ml of water was mixed to obtain a coating solution for the back surface protective layer.

(Preparation of Silver Halide Emulsion 1) Distilled water 1421
Then, 8.0 ml of a 1% by weight potassium bromide solution was added to the mixture, and further, 8.2 ml of 1N nitric acid and 20 g of phthalated gelatin were added to the solution while stirring in a titanium-coated stainless steel reaction pot at 39 ° C.
The solution A was diluted with distilled water to 37.04 g of silver nitrate and diluted to 159 ml, and 32.6 g of potassium bromide was added to a volume of 200 ml with distilled water.
Was prepared, and the entire amount of the solution A was added at a constant flow rate over 1 minute while maintaining the pAg at 8.1 by the control double jet method. Solution B was added by a controlled double jet method. Thereafter, 30 ml of a 3.5% by weight aqueous solution of hydrogen peroxide was added, and 36 ml of a 3% by weight aqueous solution of benzimidazole was further added. Then, solution A2 was again diluted with distilled water to 317.5 ml, and solution B was dissolved with potassium trichloride iridate 3 potassium salt in solution B so that the final concentration was 1 × 10 ^-4 mole per mole of silver. Then, using solution B2 diluted with distilled water to 400 ml twice the volume of solution B, apply solution A2 at a constant flow rate for 10 minutes while maintaining pAg at 8.1 by the controlled double jet method as well. The whole amount was added. Solution B2 was added by a controlled double jet method. Thereafter, 50 ml of a 0.5% by weight methanol solution of 5-methyl-2-mercaptobenzimidazole was added, the pAg was further raised to 7.5 with silver nitrate, and the pH was adjusted to 3.
8 to stop stirring, perform sedimentation / desalination / water washing process,
3.5 g of deionized gelatin was added, and 1N sodium hydroxide was added to adjust the pH to 6.0 and a pAg of 8.2 to prepare a silver halide dispersion.

The grains in the completed silver halide emulsion were pure silver bromide cubic grains having an average equivalent sphere diameter of 0.06 μm and a variation coefficient of equivalent sphere diameter of 18% (the corners were slightly rounded).
Met. The particle size and the like were determined from a volume weighted average of 1000 particles using an electron microscope. The [100] plane ratio of these particles was determined to be 85% using the Kubelka-Munk method.

The above emulsion was maintained at 38 ° C. with stirring,
0.035 g of benzoisothiazolinone (added in a 3.5% by weight methanol solution) was added, and after 40 minutes, a solid dispersion of the spectral sensitizing dye A (aqueous gelatin solution) was added at 5 × 10 ^-3 mol per mol of silver, and 1 minute later After raising the temperature to 47 ° C., 20 minutes later, 3 × 10 ⁻⁵ mol of sodium benzenethiosulfonate was added to 1 mol of silver, and 2 minutes later, tellurium sensitizer B was added at 5 × 10 5 mol per mol of silver.
^-5 mol was added and the mixture was aged for 90 minutes. N, N'-
5 ml of a 0.5 wt% methanol solution of dihydroxy-N "-diethylmelamine was added, the temperature was lowered to 31 ° C., and 5 ml of a 3.5 wt% methanol solution of phenoxyethanol and 5-methyl-2 were added.
-7 x 10 mercaptobenzimidazole per mole of silver
^-3 mol and 1-phenyl-2-heptyl-5-mercapto-1,
Silver halide emulsion 1 was prepared by adding 6.4 × 10 ⁻³ mol of 3,4-triazole to 1 mol of silver.

(Preparation of Silver Halide Emulsion 2) In the preparation of Silver Halide Emulsion 1, the liquid temperature of 39 ° C. during grain formation was changed to 47 ° C.
In the same manner, a pure silver bromide cubic grain emulsion having an average equivalent sphere diameter of 0.08 μm and a coefficient of variation in equivalent spherical diameter of 15% was prepared in the same manner. Precipitation / desalting / washing / dispersion was carried out in the same manner as in silver halide emulsion 1. Further, spectral sensitization, chemical sensitization and 5-methyl-2-mercaptobenzimidazole were carried out in the same manner as in Emulsion 1, except that the addition amount of the spectral sensitizing dye A was changed to 4.5 × 10 ^-3 mol per mol of silver. 1-Phenyl-2-heptyl-5-mercapto-1,3,4-triazole was added to obtain a silver halide emulsion 2.

(Preparation of Silver Halide Emulsion 3) In the preparation of silver halide emulsion 1, the liquid temperature of 39 ° C. during grain formation was changed to 25 ° C.
In the same manner, a pure silver bromide cubic grain emulsion having an average sphere equivalent diameter of 0.03 μm and a coefficient of variation in sphere equivalent diameter of 15% was prepared in the same manner. Precipitation / desalting / washing / dispersion was carried out in the same manner as in silver halide emulsion 1. Further, spectral sensitization, chemical sensitization and 5-methyl-2-mercaptobenzimidazole were carried out in the same manner as in Emulsion 1, except that the addition amount of the spectral sensitizing dye A was changed to 7 × 10 ^-3 mol per mol of silver. 1-phenyl-2-heptyl-5-mercapto
Addition of -1,3,4-triazole and silver halide emulsion 3
I got

(Preparation of Silver Halide Emulsion 4) In the preparation of silver halide emulsion 1, the liquid temperature of 39 ° C. during grain formation was changed to 32 ° C.
In the same manner, a pure silver bromide cubic grain emulsion having an average equivalent sphere diameter of 0.045 μm and a coefficient of variation in equivalent spherical diameter of 15% was prepared in the same manner. Precipitation / desalting / washing / dispersion was carried out in the same manner as in silver halide emulsion 1. Further, spectral sensitization, chemical sensitization, and 5-methyl-2-mercaptobenzimidazole were carried out in the same manner as in Emulsion 1, except that the amount of the spectral sensitizing dye A was changed to 6 × 10 ^-3 mol per mol of silver. 1-phenyl-2-heptyl-5-mercapto
Addition of -1,3,4-triazole and silver halide emulsion 4
I got

(Preparation of Emulsion A for Coating Solution) Emulsion A for coating solution was prepared using the silver halide emulsions 1 to 4.
The mixing ratio of the silver halide emulsion is as described in Table 1. Emulsion A was added with 7 × 10 ⁻³ mol of benzothiazolium iodide in 1% by weight aqueous solution per mol of silver.

(Preparation of scaly silver salt of fatty acid) 87.6 g of behenic acid (product name: Edenor C22-85R) manufactured by Henkel, 423 ml of distilled water, 49.2 ml of 5N-NaOH aqueous solution, 120 ml of tert-butanol
Were mixed and reacted at 75 ° C. for 1 hour with stirring to obtain a sodium behenate solution. Separately, an aqueous solution of 40.4 g of silver nitrate 206.
2 ml (pH 4.0) was prepared and kept at 10 ° C. 30 reaction vessels containing 635 ml of distilled water and 30 ml of tert-butanol
C., and with stirring, the total amount of the sodium behenate solution and the total amount of the silver nitrate aqueous solution were stirred at a constant flow rate for 62 minutes each.
The addition took 10 seconds and 60 minutes. At this time, only the aqueous silver nitrate solution was added for 7 minutes and 20 seconds after the start of the aqueous silver nitrate solution addition, and then the addition of the sodium behenate solution was started. After the addition of the aqueous silver nitrate solution was completed, only the sodium behenate solution was added for 9 minutes and 30 seconds. Was added. At this time,
The temperature inside the reaction vessel was set at 30 ° C., and the external temperature was controlled so that the liquid temperature became constant. In addition, the piping of the addition system of the sodium behenate solution is kept warm by steam tracing,
The steam opening was adjusted so that the liquid temperature at the outlet at the tip of the addition nozzle was 75 ° C. The piping of the silver nitrate aqueous solution addition system was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution and the addition position of the silver nitrate aqueous solution are symmetrically arranged around the stirring axis.
The height was adjusted so as not to contact the reaction solution.

After the completion of the addition of the sodium behenate solution, the mixture was left to stir at the same temperature for 20 minutes, and the temperature was lowered to 25 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtered water became 30 μS / cm. Thus, a fatty acid silver salt was obtained. The obtained solid content was stored as a wet cake without drying. When the morphology of the obtained silver behenate particles was evaluated by electron micrographing, a = 0.
14 μm, b = 0.4 μm, c = 0.6 μm, average aspect ratio 5.
2. A scaly crystal having an average equivalent spherical diameter of 0.52 μm and a coefficient of variation of equivalent spherical diameter of 15%. (A, b, c are the rules of the text)

For a wet cake having a dry solid content of 100 g, 7.4 g of polyvinyl alcohol (trade name: PVA-217)
And water were added to make the total amount 385 g, followed by preliminary dispersion with a homomixer. Next, the pre-dispersed stock solution is dispersed in a dispersing machine (trade name: Microfluidizer M-110SE-E).
H, manufactured by Microfluidics International Corporation, using a G10Z interaction chamber) at a pressure of 1750 kg / cm ^2, and processed three times to obtain a silver behenate dispersion. For cooling operation, install a coiled heat exchanger before and after the interaction chamber, respectively.
The dispersion temperature was set at 18 ° C. by adjusting the temperature of the refrigerant.

(Preparation of 25% by weight dispersion of reducing agent) 10 kg of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and modified polyvinyl alcohol (Kuraray
10% of a 20% by weight aqueous solution of Poval MP203 manufactured by
6 kg was added and mixed well to form a slurry. This slurry is sent by a diaphragm pump and has an average diameter of 0.5 mm.
Horizontal sand mill filled with zirconia beads (UVM-
2: 3 hours and 30 minutes by using IMEX Co., Ltd., and then 0.2 g of benzoisothiazolinone sodium salt and water were added to adjust the concentration of the reducing agent to 25% by weight. I got The reducing agent particles contained in the thus obtained reducing agent dispersion have a median diameter of 0.42 μm and a maximum particle diameter of 2.0 μm.
It was below. The resulting reducing agent dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

(Preparation of a 25% by weight dispersion of the compound represented by the formula (1)) 100 g of the compound of the formula (1) and 20% by weight of a modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.)
100 g of an aqueous solution, 4.5 g of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate, and 195.5 g of water are added and mixed well to form a slurry. Into a sand grinder mill (IMEX Co., Ltd.)
), And 100 ppm of benzoisothiazolinone sodium salt was added to obtain a solid fine particle dispersion. The median diameter of the solid fine particle dispersion fine particles thus obtained is 0.35 to 0.3.
It was in the range of 45 μm, and the maximum particle size was 2.0 μm or less. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

(Preparation of 5% by weight solution of phthalazine compound) 8 kg of modified polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.) was dissolved in 174.57 g of water, and then 3.15 kg of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate. And 14.28 kg of a 70% by weight aqueous solution of 6-isopropylphthalazine were added to prepare a 5% by weight solution of 6-isopropylphthalazine. (Preparation of 20% by weight dispersion of pigment) CI Pigment Blue 60
Of water and 250 g of water were added to 64 g of Demol N manufactured by Kao Corporation and 6.4 g, and mixed well to form a slurry. 800 g of zirconia beads having an average diameter of 0.5 mm were prepared, put into a vessel together with the slurry, and dispersed with a dispersing machine (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) for 25 hours to obtain a pigment dispersion.
The pigment particles contained in the pigment dispersion thus obtained have an average particle size.
It was 0.21 μm.

(Preparation of SBR latex 40% by weight) Ultrafiltration (UF) purified SBR latex was obtained as follows. The following SBR latex was diluted 10 times with distilled water and UF-
Using a purification module FS03-FC-FUY03A1 (Daisen Membrane System Co., Ltd.), dilute and purify until the ionic conductivity becomes 1.5 mS / cm.
Was added to be 0.22% by weight. Further, NaOH and NH4OH were added so that Na + ion: NH4 + ion = 1: 2.3 (molar ratio) to adjust the pH to 8.4. The latex concentration at this time was 40% by weight. (SBR latex: -St (68) -Bu (29) -AA (3)-latex)
Average particle size 0.1 μm, concentration 45%, equilibrium water content at 25 ° C, 60% RH 0.6% by weight, ionic conductivity 4.2mS / cm (Ion conductivity is measured by a conductivity meter CM- manufactured by Toa Denpa Kogyo Co., Ltd. Using 30S, measure latex stock solution (40%) at 25 ° C), pH 8.2

(Preparation of Emulsion Layer (Image Forming Layer) Coating Solution) 1.1 g of a 20% by weight aqueous dispersion of the pigment obtained above, 103 g of a silver salt of an organic acid, polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.) )
5 g of a 20% by weight aqueous solution of the above, 25 g of the above 25% by weight reducing agent dispersion,
The compound represented by the formula (1) (type and amount (mol / mol-Agβ of the addition amount in Table 1 represents the number of moles added per mole when silver halide and organic silver acid are added) ) Are listed in Table 1), pH-adjusted SBR latex 4 purified by ultrafiltration (UF).
106 g of 0% by weight and 18m of a 5% by weight solution of a phthalazine compound
l, add 10 g of silver halide mixed emulsion A well,
Prepare a coating solution for the emulsion layer and pass it directly to the coating die.
The solution was fed so as to be ml / m ² and applied. The viscosity of the emulsion layer coating solution was measured at 40 ° C (No.
It was 85 [mPa · s] at 1 rotor, 60 rpm). The viscosity of the coating solution at 25 ° C. using an RFS fluid spectrometer manufactured by Rheometrics Far East Co., Ltd. was 150 at a shear rate of 0.1, 1, 10, 100, and 1000 [1 / sec].
The values were 0, 220, 70, 40, and 20 [mPa · s].

(Preparation of Emulsion Surface Intermediate Layer Coating Solution) A 10% by weight aqueous solution of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.)
g, 20% pigment dispersion 5.3 g, methyl methacrylate /
Styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer weight ratio 64/9/20/5 /
2) 2 ml of a 57.5% aqueous solution of aerosol OT (manufactured by American Cyanamid) and 10.5 ml of a 20% by weight aqueous solution of diammonium phthalate were added to 226 g of a 27.5% by weight latex solution.
Add water to 880 g to make the middle layer coating solution, 10 ml / m
^The solution was fed to the coating die so as to be ² . The viscosity of the coating solution is 21 mPa with a B-type viscometer at 40 ° C (No. 1 rotor, 60 rpm).
[S].

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

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

(Preparation of Photothermographic Material) On the back surface side of the undercoating support, an antihalation layer coating solution was applied so that the solid content of the solid fine particle dye was 0.04 g / m ² and the back surface was protected. The layer coating solution was simultaneously layer-coated so that the gelatin coating amount was 1.7 g / m ^2, and dried to form an antihalation back layer. On the side opposite to the back side, from the undercoat side, the emulsion layer (silver halide coated silver amount 0.14 g / m ² ), the intermediate layer, the protective layer first layer, and the protective layer second layer in the order of the slide bead coating method. Simultaneous multilayer coating was performed to prepare a sample of the photothermographic material. The coating is performed at a speed of 160 m / min.The distance between the coating die tip and the support is 0.14 to 0.28 mm.
m so that the pressure in the decompression chamber is
92Pa lower. At that time, the handling and the temperature and humidity were controlled so that the support was not charged, and the charge was removed by ion wind immediately before coating. In the subsequent chilling zone, air with a dry-bulb temperature of 18 ° C and a wet-bulb temperature of 12 ° C is blown for 30 seconds to cool the coating liquid, and then the dry-bulb temperature is raised in the hovering-type floating-type drying zone. Dry air at 30 ℃, wet bulb temperature 18 ℃, 200
After spraying for 70 seconds and passing through a drying zone at 70 ° C for 20 seconds,
The solution was passed through a drying zone at 90 ° C. for 10 seconds, and then cooled to 25 ° C. to evaporate the solvent in the coating solution. The average wind speed of the wind blowing on the coating liquid film surface in the chilling zone and the drying zone was 7 m / sec.

[0160]

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(Evaluation of photographic performance) Exposure of photographic materials with Fuji Medical Dry Laser Imager FM-DPL (equipped with a 660 nm semiconductor laser with a maximum output of 60 mW (IIIB))
After heat development (about 120 ° C.), the obtained image was evaluated with a densitometer.

The sensitivity was evaluated by the reciprocal of the ratio of the exposure amount giving a density higher than fog (Dmin) by 1.0, and the fresh sample of Experiment No. 1 was expressed as a reference (as 100).
The sensitivity needs to be 95 to 105 as a practical viewpoint.

(Evaluation of Raw Storage Property of Photothermographic Material) Each photothermographic material sample was conditioned at 25 ° C. and a humidity of 30% RH, cut into a sheet state, and three sheets were placed in a moisture-proof bag. Make 3 sets each, (1) Store at 60 ° C for 7 hours, (2) Store at 40 ° C for 3 days, and then heat-develop photosensitive material before storage and 3
The exposure and heat development treatment described above were performed on the central sample (second sheet) of the stacked sheets, and the photographic properties were evaluated. (Of the storage conditions
7 hours at 60 ° C is an experiment in a car in the midsummer daytime. )

Tables 1 and 2 show the results. In the table, the numbers of the compounds represented by the formula (1) correspond to the numbers of the compounds whose structures have been shown as preferred compounds. The structures of other organic polyhalogen compounds are shown below. The organic polyhalogen compound was dispersed in the same manner as the compound represented by the formula (1).
-4 was added after neutralization with an equimolar aqueous sodium hydroxide solution. The photothermographic material of the present invention was shown to have high sensitivity and excellent storage stability before development.

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[Table 1]

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[Table 2]

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<Example 2> In the production process of Sample No. 205 described in Example 2 of JP-A-11-174621, the above heteroaromatic mercapto compound (A) was used in place of compound A, Further, two types of photothermographic materials were prepared using the solid fine particle dispersion of the compound P-24 or the comparative compound 1 in place of tripromomethylphenylsulfone. The addition amount of the heteroaromatic mercapto compound (A) and the addition amount of the compound P-24 or the comparative compound 1 were the same as those of the samples of Experiment No. 1 or 4 in Table 1. When the photographic performance evaluation and the storability evaluation were performed in the same manner as in Example 1, as in Table 1, the sample using the compound P-24 was more preferable than the sample using the comparative compound 1 as a result.

<Example 3> In the production process of Level 2 described in Example 1 of Japanese Patent Application No. 11-195011, the above heteroaromatic mercapto compound (A) was used in place of compound B. And using compound P-24 above or comparative compound 1 above instead of compound I-39,
Various types of photothermographic materials were prepared. The addition amount of the heteroaromatic mercapto compound (A) and the addition amount of the compound P-24 or the comparative compound 1 were the same as those of the samples of Experiment No. 1 or 4 in Table 1. When the photographic performance evaluation and the storability evaluation were performed in the same manner as in Example 1, as in Table 1, the sample using the compound P-24 was more preferable than the sample using the comparative compound 1 as a result.

[0170]

According to the present invention, it is possible to provide a photothermographic material having high sensitivity, high image quality, excellent storage stability when not yet developed, and, for example, extremely low sensitivity reduction during high-temperature storage. Therefore, the photothermographic material of the invention is useful for medical images and photolithography.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Katsuyuki Watanabe 210 Nakanakanuma, Minamiashigara-shi, Kanagawa Fuji Photo F-term in Ashigara Research Laboratories, Film Corporation 2H123 AB00 AB03 AB06 AB23 AB28 AB29 BB00 BB27 BC00 BC01 CB00 CB03

Claims (2)

[Claims] At least one kind is provided on one surface of a support.
Of photosensitive silver halide, non-photosensitive organic silver salt, silver ion
Photothermographic material having a reducing agent and a binder for the same
In, the average grain size of the photosensitive silver halide is 0.00
1 μm or more and 0.06 μm or less, and at least two types
Containing the above organic polyhalogen compounds,
At least one organic polyhalogen compound represented by the formula (1)
A photothermographic material, which is a material. Embedded image[In the formula (1), Z₁And Z_TwoAre independent
X represents a halogen atom ₁Is a hydrogen atom or electron-withdrawing property
Y represents a group₁Is -CO- group or SO_Two-Represents a group
And Q represents an arylene group or a divalent heterocyclic group.
L represents a linking group;₁And W_TwoAre independent
A hydrogen atom, an alkyl group, an aryl group, or a hetero ring
Represents a group. n represents 0 or 1. ] 2. The method according to claim 1, wherein the layer containing the organic polyhalogen compound represented by the formula (1) is formed by an aqueous coating solution, and the organic polyhalogen compound represented by the formula (1) is an aqueous dispersion. The photothermographic material according to claim 1, wherein the photothermographic material is added to an aqueous coating solution.