JP2002062616A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material having high activity in heat development, excellent also in image preservability and having high sensitivity and rapid developability. SOLUTION: In the heat developable photosensitive material with photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one face of the base, a compound of formula (A) and a hydrogen bond forming compound are held on the same face and the reducing agent is a compound of formula (I) which may form a complex with the hydrogen bond forming compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a photothermographic material. More specifically, the present invention relates to a photothermographic material having high heat development activity, excellent image storability, and high sensitivity and rapid development.

[0002]

2. Description of the Related Art In recent years, in the field of medical diagnostic films and photoengraving films, it has been strongly desired to reduce the amount of processing waste liquid from the viewpoint of saving space. Photothermographic film as a medical diagnostic film and photoengraving film that can be efficiently exposed by a laser imagesetter or laser imager and can form a clear black image having high resolution and sharpness There is a need for materials technology. According to such a photothermographic material, it is possible to supply a heat development processing system which does not require a solution processing chemical and is simpler and does not damage the environment to customers.

[0003] In the field of general image forming materials, there is a similar requirement, but in particular, medical diagnostic images are required to be finely described, so that high quality images having excellent sharpness and granularity are required, and diagnostic images are required. There is a feature that a cool black image is preferred from the viewpoint of ease of operation. At present, various hard copy systems using pigments and dyes, such as inkjet printers and electrophotographs, are distributed as general image forming systems, but none of them are satisfactory as medical image output systems.

On the other hand, a method of forming an image by thermal development using an organic silver salt is disclosed in, for example, US Pat.
No. 904, 3,457,075 and D.C. "Thermally Processed Silver S" by Klosterboer
ystems) "(Imaging Processors and
Materials (Imaging Processes and Materials) Neb
lette 8th edition, J.M. Sturge, V.S. Walworth, A.M. Shepp editing,
Chapter 9, p. 279, 1989).
Such photothermographic materials generally include a reducible silver salt (eg, an organic silver salt), a catalytically active amount of a photocatalyst (eg, silver halide), a reducing agent, and if necessary, a color tone agent for controlling the color tone of silver. And a photosensitive layer dispersed in a binder matrix. When a photothermographic material is heated to a high temperature (for example, 80 ° C. or higher) after image exposure, silver is generated through an oxidation-reduction reaction between a reducible silver salt (which functions as an oxidizing agent) and a reducing agent. This oxidation-reduction reaction is promoted by the catalytic action of the latent image of silver halide formed by exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas becomes black and forms an image because it contrasts with the unexposed areas. These techniques are described in U.S. Pat. No. 2,910,377,
It is disclosed in many documents including 3-4924.

The photothermographic material has been widely used in the market as an excellent system which has been recently considered important because it does not require a processing agent and does not discharge a large amount of waste material. . However, in this system, since a reducing agent is incorporated in the photosensitive material in advance, there is a fundamental problem that the photosensitive material after processing is inferior in the stable preservation property to the system using the conventional developing solution. .

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photothermographic material having high heat development activity and excellent image storability.

[0007]

The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a photosensitive silver halide, a non-photosensitive organic silver salt, a silver ion A photothermographic material having a reducing agent and a binder for the compound, wherein the compound represented by the general formula (A) and a hydrogen bonding compound as defined in the present specification are contained, and further defined as the reducing agent in the present specification. It has been found that when the compound represented by the general formula (I) is used, it is possible to provide an excellent photothermographic material having desired effects, thereby completing the present invention.

That is, according to the present invention, there is provided a photothermographic material comprising a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one surface of a support. A compound represented by the general formula (A) and a hydrogen bonding compound are provided on the surface containing the photosensitive silver halide, and the reducing agent is a compound represented by the following general formula (I) (general formula (I) (The compound represented by (I) may form a complex with the hydrogen bonding compound).

Embedded image [In the general formula (I), R ¹¹ and R ^{11 ′} each independently represent an alkyl group. R ¹² and R ^{12 ′} each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. X ¹¹ and X ^{11 ′} each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. R ¹¹ and X ¹¹ , R ^{11 '}
And X ^{11 ′} , R ¹² and X ¹¹ , and R ^{12 ′} and X ^{11 ′} may be bonded to each other to form a ring. L is -S- group or -C
Represents an HR ¹³ -group, wherein R ¹³ represents a hydrogen atom or an alkyl group. ]

Embedded image [In the general formula (A), P represents an oxygen atom, a sulfur atom or an NH group. Q ¹ represents an oxygen atom or a sulfur atom. Y ¹ is an OH group, OM group, SH group, SM group (wherein, M
Represents a counter ion) or an NH ₂ group. L ¹ represents a divalent linking group. Z represents an alkyl group, an aryl group or a heterocyclic group. ]

Preferably, the hydrogen bonding compound is a compound represented by the following general formula (II).

Embedded image [In the general formula (II), R ²¹ , R ²² and R ²³ each independently represent an alkyl group, an aryl group, an alkoxy group,
Represents an aryloxy group, an amino group or a heterocyclic group,
These groups may be unsubstituted or have a substituent, and any two of R ²¹ , R ²² and R ²³ may be bonded to each other to form a ring. ]

Preferably, the photothermographic material of the present invention comprises:
On the same surface as the photosensitive silver halide, there is further provided a polyhalogen compound represented by the following general formula (III). Q- (Y) nC (Z ¹ ) (Z ² ) X (III) [In the general formula (III), Q represents an alkyl group, an aryl group or a heterocyclic group, and Y represents a divalent linking group. Represent
n represents 0 or 1, Z ¹ and Z ² each independently represent a halogen atom, and X represents a hydrogen atom or an electron-withdrawing group. ]

Preferably, the binder is an aqueous latex. Preferably, the average glass transition temperature of the binder is between 20C and 60C.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The photothermographic material of the present invention will be described below in detail. In addition, in this specification, “to” is a range including numerical values described before and after it as a minimum value and a maximum value. The photothermographic material of the invention has a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one surface of a support, and has a general formula (A) ) And a hydrogen bonding compound, wherein the reducing agent is a compound represented by the following general formula (I). A photothermographic material having such characteristics has high heat development activity, excellent storage stability of an unprocessed photosensitive material, and high sensitivity and rapid development.

The reducing agent represented by formula (I) will be described in detail. In the general formula (I), R ¹¹ and R
^{11 ′} each independently represents an alkyl group. In particular,
It is a substituted or unsubstituted, linear, branched or cyclic alkyl group, preferably an alkyl group having 1 to 20 carbon atoms. The substituent of the alkyl group is not particularly limited, but is preferably an aryl group, a hydroxy group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acylamino group, a sulfonamide group, a sulfonyl group, a phosphoryl group, Examples include an acyl group, a carbamoyl group, an ester group, and a halogen atom.

R ¹¹ and R ^{11 ′} are more preferably a secondary or tertiary alkyl group having 3 to 15 carbon atoms, specifically, isopropyl, isobutyl, t-butyl,
Examples thereof include a t-amyl group, a t-octyl group, a cyclohexyl group, a cyclopentyl group, a 1-methylcyclohexyl group, and a 1-methylcyclopropyl group. More preferably, it is a tertiary alkyl group having 4 to 12 carbon atoms.
A butyl group, a t-amyl group, and a 1-methylcyclohexyl group are particularly preferred, and a t-butyl group is most preferred.

R ¹² and R ^{12 ′} each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. X ¹¹ and X ^{11 ′} each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. The group that can be substituted on the benzene ring preferably includes an alkyl group, an aryl group, a halogen atom, an alkoxy group, an acylamino group, and the like.

R ¹² and R ^{12 ′} are preferably those having 1 carbon atom
To 20 alkyl groups, specifically, methyl, ethyl, propyl, butyl, isopropyl, t-butyl, t-amyl, cyclohexyl, 1-methylcyclohexyl, benzyl, methoxy Examples include a methyl group and a methoxyethyl group. More preferably a methyl group,
It is an ethyl group, a propyl group, an isopropyl group or a t-butyl group.

X ¹¹ and X ^{11 ′} are preferably a hydrogen atom, a halogen atom or an alkyl group, particularly preferably a hydrogen atom. R ¹¹ and X ¹¹ , R ^{11 ′} and X ^{11 ′} , R ¹²
And X ¹¹ , and R ^{12 ′} and X ^{11 ′} may be bonded to each other to form a ring. This ring is preferably a 5- to 7-membered ring, more preferably a saturated 6-membered ring.

L represents a —S— group or a —CHR ¹³ — group, and R ¹³ represents a hydrogen atom or an alkyl group. R ¹³ is
Specifically, it is a substituted or unsubstituted linear, branched or cyclic alkyl group, preferably an alkyl group having 1 to 20 carbon atoms. Specific examples of the unsubstituted alkyl group represented by R ¹³ include a methyl group, an ethyl group, a propyl group,
Examples thereof include a butyl group, a heptyl group, an undecyl group, an isopropyl group, a 1-ethylpentyl group, and a 2,4,4-trimethylpentyl group. Substituent of the substituted alkyl groups represented by R ¹³ are the same as the substituents for the alkyl group represented by R ¹¹ and R ^{11 '.}

L is preferably a --CHR ¹³ -group. R
¹³ is preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and the alkyl group is preferably a primary or secondary alkyl group having 1 to 8 carbon atoms, more preferably a methyl group, Ethyl group, n-propyl group, isopropyl group or 2,4,4-trimethylpentyl group, more preferably methyl group, ethyl group, n-propyl group or isopropyl group, particularly preferably,
It is a methyl group, an ethyl group or an n-propyl group.

When R ¹³ is a hydrogen atom, R ¹² and R
^{12 ′} is preferably an alkyl group having 2 or more carbon atoms,
It is more preferably an alkyl group having 2 to 5 carbon atoms, further preferably an ethyl group or a propyl group, and most preferably an ethyl group. When R ¹³ is an alkyl group, R ¹² and R ^{12 ′} are preferably an alkyl group, particularly preferably a methyl group.

Preferably, in the compound represented by the formula (I), R ¹¹ and R ^{11 ′} are each independently a secondary or tertiary alkyl group, and R ¹² and R ^{12 ′} are each independently an alkyl group. L is -S- group or -C
An HR ¹³ — group, wherein R ¹³ is a hydrogen atom or an alkyl group, and both X ¹¹ and X ^{11 ′} are hydrogen atoms.

Preferably, in the compound represented by the formula (I), R ¹¹ and R ^{11 ′} are each independently a tertiary alkyl group, R ¹² and R ^{12 ′} are each independently an alkyl group, L is a —S— group or a —CHR ¹³ — group, and R ¹³ is an alkyl group. Preferably, in the compound represented by the general formula (I), R ¹¹ and R ^{11 ′} are each independently a tertiary alkyl group, and R ¹² and R 11
^{12 ′} are each independently an alkyl group having 2 or more carbon atoms, L is a —S— group or a —CHR ¹³ — group, and R ¹³
Is a hydrogen atom.

Specific examples of the compound represented by formula (I) are shown below, but the compounds which can be used in the present invention are not limited to these.

[0024]

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[0025]

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[0026]

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[0027]

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[0028] In the present invention, the general formula addition amount of the reducing agent represented by formula (I) is preferably 0.01~5.0g / m ^2, at 0.1 to 3.0 g / m ² More preferably, it is contained in an amount of 5 to 50% by mol, preferably 10 to 10 mol, based on 1 mol of silver on the surface having photosensitive silver halide.
More preferably, it is contained in an amount of about 40 mol%. The reducing agent is preferably contained in the image forming layer.

The reducing agent may be contained in the coating solution by any method such as a solution form, an emulsified dispersion form, and a solid fine particle dispersion form, and may be contained in the photosensitive material. Well-known emulsification dispersion methods include oils such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and an auxiliary solvent such as ethyl acetate or cyclohexanone. A method for producing the same is given.

As the solid fine particle dispersion method, a powder of a reducing agent is dispersed in a suitable solvent such as water by a ball mill, a colloid mill, a vibrating ball mill, a sand mill, a jet mill, a roller mill or an ultrasonic wave to obtain a solid dispersion. And a method for producing a product. At that time, a protective colloid (for example, polyvinyl alcohol) and a surfactant (for example, an anionic surfactant such as sodium triisopropylnaphthalenesulfonate (a mixture of three isopropyl groups having different substitution positions)) may be used. The aqueous dispersion can contain a preservative (eg, benzoisothiazolinone sodium salt).

The photothermographic material of the present invention has the general formula (A)
It contains the compound represented by. Hereinafter, the compound represented by Formula (A) will be described. In the general formula (A), P represents an oxygen atom, a sulfur atom, or an NH group. Q ¹
Represents an oxygen atom or a sulfur atom. Y ¹ is an OH group, OM
Group, SH group, SM group (where M represents a counter ion) or NH ₂ group.

Preferred combinations of the substituents represented by-(C = Q ¹ ) -Y ¹ are carboxy, carboxylate, thiocarboxy, thiocarboxylate, dithiocarboxy, dithiocarboxylate, carbamoyl. It is.

M represents a counter ion. Examples of counterions include inorganic or organic ammonium ions (eg,
Ammonium ion, triethylammonium ion,
Pyridinium ion), alkali metal ion (for example,
Examples include sodium ions, potassium ions), alkaline earth metal ions (eg, calcium ions, magnesium ions), and other metal ions (eg, aluminum ions, barium ions, zinc ions). As the counter ion, an ionic polymer, another organic compound having a reverse charge, or a metal complex ion (for example, hydroxopentaaquaaluminum (III) ion, tris (2,2′-bipyridine) iron (II) ion)
Is also possible. Further, it may form an inner salt with another substituent in the molecule. Preferred are sodium ion, potassium ion and ammonium ion. Triethylammonium ion and pyridinium ion,
Further preferred are sodium ion, potassium ion and ammonium ion.

In the general formula (A), L ¹ represents a divalent linking group. The linking group represented by L ¹ is preferably a divalent linking group having a length of 1 to 4 atoms, more preferably 1 to 2 atoms, and may further have a substituent. -CH ₂ Preferred examples _{-, - CH 2 CH 2 -} , - CH (CH 3) -,
—CH (CH ₂ CH ₃ ) CH ₂ — and the like. Particularly preferred is —CH ₂ —.

In the general formula (A), Z is an alkyl group,
Represents an aryl group or a heterocyclic group. The alkyl group represented by Z is a linear, branched, cyclic or combination thereof, and preferably has 1 to 40 carbon atoms.
More preferably, it is 1 to 30, further preferably 1 to 25. For example, methyl, ethyl, allyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl, sec-pentyl, isopentyl, tert-pentyl, hexyl, cyclohexyl, octyl, tert-octyl, decyl, undecyl, Dodecyl, tridecyl, pentadecyl, nonadecyl, icosyl, docosyl, 2-hexyldecyl, 2-ethylhexyl, 6-methyl-1- (3-methylhexyl) nonyl, benzyl and the like.

The alkyl group represented by Z may have a substituent and may be any known substituent. Examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom). , Or iodine atom), an alkyl group,
Substituted with an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group (including an N-substituted nitrogen-containing heterocyclic group, for example, a morpholino group), an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, an imino group, and an N atom Imino group, thiocarbonyl group, carbazoyl group, cyano group, thiocarbamoyl group, alkoxy group, aryloxy group, heterocyclic oxy group, acyloxy group, (alkoxy or aryloxy) carbonyloxy group, sulfonyloxy group, acylamide group, sulfone Amide group, ureido group, thioureido group, imide group, (alkoxy or aryloxy) carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, (alkyl or aryl) sulfonyluureido group, nitro , (Alkyl or aryl) sulfonyl group, sulfamoyl group, group having a phosphoric acid amide or phosphate ester structure, silyl group, carboxyl group or salt thereof, sulfo group or salt thereof, phosphate group, hydroxy group, quaternary ammonium group And the like. These substituents may be further substituted with these substituents. Examples thereof include an aryloxyalkyl group, an alkoxyalkyl group, a polyalkyleneoxyalkyl group (such as a hydroxyethoxyethyl group, an ethoxyethyl group, and an ethoxyethoxyethyl group), and an alkylthioalkyl group (such as an ethylthioethyl group). .

The aryl group represented by Z is a monocyclic or condensed-ring aryl group, preferably has 6 to 20 carbon atoms, more preferably has 6 to 16 carbon atoms, still more preferably has 6 to 10 carbon atoms, and is a phenyl group or a naphthyl group. Groups are preferred.

The aryl group represented by Z may have a substituent, and any substituent may be used as long as it does not adversely affect photographic performance. Examples include the same groups as the substituents of the group.
The preferred substitution position of the substituent on the aryl group is at the 2-position, and it is preferable that the substituent can form a complex with silver ion together with P, Q ¹ or Y ¹ . Preferred examples of the substituent and the substitution position include a 2-carboxy group, a 2-carbamoyl group, a 2-thiocarboxy group, and a 2-dithiocarboxyl group.

The heterocyclic group represented by Z is a 5- to 7-membered saturated or unsaturated monocyclic or condensed heterocyclic ring having at least one heteroatom selected from the group consisting of nitrogen, oxygen and sulfur atoms. Those that are rings are preferred. Examples of heterocycles are preferably pyridine, quinoline, isoquinoline, pyrimidine, pyrazine, pyridazine, phthalazine,
Triazine, furan, thiophene, pyrrole, oxazole, benzoxazole, thiazole, benzothiazole, imidazole, benzimidazole, thiadiazole, triazole and the like, more preferably pyridine, quinoline, pyrimidine, thiadiazole, benzothiazole, particularly preferably , Pyridine, quinoline, pyrimidine. The heterocyclic group represented by Z may have a substituent, and examples thereof include the same groups as the above-described substituents of the alkyl group.

Z is preferably a phenyl group, a naphthyl group, a quinolyl group, a pyridyl group, a pyrimidyl group, or a polyethyleneoxy group, more preferably a phenyl group or a substituted phenyl group, and particularly preferably a 2-alkyl group. A phenyl group, a 2,4-dialkylphenyl group, a 2-carboxyphenyl group, a 2-carbamoylphenyl group, and a 2-thiocarboxyphenyl group. Further, as a substituent of Z, a so-called ballast group known in photographic materials, an adsorptive group to a silver salt, or a group imparting water solubility may be included. The substituents may be bonded to each other to form a bis-type, a tris-type, or a tetrakis-type, or may be polymerized with each other to form a polymer.

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

Further, oils such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and co-solvents such as ethyl acetate and cyclohexanone are prepared by the well-known emulsification dispersion method. And then mechanically produce and use an emulsified dispersion. Alternatively, a powder of the compound represented by the general formula (A) may be dispersed in a suitable solvent such as water by ball mill, colloid mill, or ultrasonic wave by a method known as a solid dispersion method. it can.

The compound represented by the general formula (A) may be added to any layer on the side containing the photosensitive silver halide with respect to the support, but it may be added to the image forming layer or adjacent thereto. Preferably, it is added to the layer.

The addition amount of the compound represented by the general formula (A) in the range of 0.01 to 10 mmol / m ^2, preferably from 0.1 to 5 mmol / m ^2, more preferably 0.2 to 2
mmol / m ² . Preferred examples of the compound represented by formula (A) are shown below, but the invention is not limited thereto.

[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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[0053]

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[0054]

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The photothermographic material of the present invention has a hydrogen bonding compound on the same surface as the photosensitive silver halide. The hydrogen bonding compound used in the present invention is a non-reducing compound having a group capable of forming a hydrogen bond with a hydroxyl group of the compound represented by the general formula (I). As a group capable of forming a hydrogen bond with a hydroxyl group, a phosphoryl group, a sulfoxide group, a sulfonyl group, a carbonyl group, an amide group,
Ester groups, urethane groups, ureido groups, tertiary amino groups,
Examples include a nitrogen-containing aromatic group. Among them, preferred are a phosphoryl group, a sulfoxide group, an amide group (provided that they have no> NH group and are blocked like> NR (R is a substituent other than H)), and urethane. Groups (provided that they have no> NH group and are blocked like> NR (R is a substituent other than H)), ureido groups (but have no> NH group, > NR (R is a substituent other than H).

In the present invention, a compound represented by the above general formula (II) is preferably used as the hydrogen bonding compound. In the general formula (II), R ²¹ , R ²² and R ²³ each independently represent an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group, and these groups are unsubstituted. May also have a substituent, and any two of R ²¹ , R ²² and R ²³ may form a ring. When R ²¹ , R ²² and R ²³ have a substituent, examples of the substituent include a halogen atom, an alkyl group,
Aryl group, alkoxy group, amino group, acyl group, acylamino group, alkylthio group, arylthio group, sulfonamide group, acyloxy group, oxycarbonyl group, carbamoyl group, sulfamoyl group, sulfonyl group, phosphoryl group and the like, preferably An alkyl group or an aryl group, and specific examples include a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a t-octyl group,
Examples include a phenyl group, a 4-alkoxyphenyl group, and a 4-acyloxyphenyl group.

Specific examples of the groups represented by R ²¹ , R ²² and R ²³ include a methyl group, an ethyl group, a butyl group, an octyl group, a dodecyl group, an isopropyl group, a t-butyl group and a t-butyl group.
Amyl group, t-octyl group, cyclohexyl group, 1-methylcyclohexyl group, benzyl group, phenethyl group, 2
A substituted or unsubstituted alkyl group such as a phenoxypropyl group; a phenyl group, an o-cresyl group, a p-cresyl group,
Xylyl group, naphthyl group, 4-t-butylphenyl group,
4-t-octylphenyl group, 4-anisidyl group, 3,
Substituted or unsubstituted aryl groups such as 5-dichlorophenyl group; methoxy group, ethoxy group, butoxy group, octyloxy group, 2-ethylhexyloxy group, 3,5,5-
Substituted or unsubstituted alkoxyl groups such as trimethylhexyloxy group, dodecyloxy group, cyclohexyloxy group, 4-methylcyclohexyloxy group, benzyloxy group; phenoxy group, cresyloxy group, isopropylphenoxy group, 4-t-butylphenoxy group, A substituted or unsubstituted aryloxy group such as a naphthoxy group and a biphenyloxy group; an amino group, a dimethylamino group, a diethylamino group, a dibutylamino group, a dioctylamino group,
Substituted or unsubstituted amino groups such as N-methyl-N-hexylamino group, dicyclohexylamino group, diphenylamino group, N-methyl-N-phenylamino group; 2-pyridyl group, 4-pyridyl group, 2-furanyl group And heterocyclic groups such as 4-piperidinyl group, 8-quinolyl group and 5-quinolyl group.

R ²¹ , R ²² and R ²³ are preferably an alkyl group, an aryl group, an alkoxy group or an aryloxy group. From the viewpoint of the effects of the present invention, one or more of R ²¹ , R ²² and R ²³ are preferably an alkyl group or an aryl group, and more preferably two or more are an alkyl group or an aryl group. Further, it is preferable that R ²¹ , R ²² and R ²³ be the same group in that they can be obtained at low cost. Specific examples of the compound represented by the general formula (II) are shown below, but the compounds that can be used in the present invention are not limited thereto.

[0059]

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[0060]

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[0061]

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[0062]

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The hydrogen bonding compound used in the present invention is
Similar to the reducing agent, it can be contained in the coating liquid in the form of a solution, an emulsified dispersion, a solid-dispersed fine particle dispersion, or the like, and can be contained in the photosensitive material. Since the hydrogen bonding compound used in the present invention forms a hydrogen bonding complex with a compound having a phenolic hydroxyl group or an amino group in a solution state, it may be isolated in a crystalline state as a complex depending on a combination with a reducing agent. Can be. It is particularly preferable to use the crystal powder of the complex thus isolated as a dispersion of solid fine particles in order to obtain stable performance. Further, a method in which a reducing agent and a hydrogen bonding compound are mixed in a powder form, and a suitable dispersant is used to form a complex at the time of dispersion with a sand grinder mill or the like can also be preferably used. The amount of the hydrogen bonding compound to be used is preferably 1 to
The content is 200 mol%, more preferably 10 to 150 mol%, and still more preferably 30 to 100 mol%.

The organic silver salt which can be used in the present invention is
Relatively stable to light, but forms a silver image when heated to 80 ° C. or higher in the presence of an exposed photocatalyst (such as a latent image of photosensitive silver halide) and a reducing agent It is a silver salt. The organic silver salt can be any organic material including a source of reducible silver ions. Such a non-photosensitive organic silver salt is disclosed in JP-A-10-62899.
No. 0048-0049, European Patent Publication E
From page 18, line 24 of P0803764A1
Page 19, line 37, European Patent Publication EP0962881
No. 2A1. Among them, a silver salt of an organic acid, particularly (10 to 30 carbon atoms, preferably 15 to 28 carbon atoms)
Silver salts of long chain aliphatic carboxylic acids are preferred. Preferred examples of the organic silver salt include silver behenate, silver arachidate,
Examples include silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, and mixtures thereof. In the present invention, among these mixtures of organic silver salts and organic acid silver salts, it is preferable to use organic acid silver having a silver behenate content of 75 mol% or more.

The shape of the organic silver salt that can be used in the present invention is not particularly limited, and examples thereof include a needle shape, a bar shape, a flat plate shape, and a scale shape. In the present invention, scaly organic silver salts are preferred. In the present specification, the flaky 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 the organic acid was approximated to a rectangular parallelepiped. The sides of the rectangular parallelepiped were designated as a, b, and c from the shortest side (c is the same as b). Then, calculation is performed using the shorter numerical values a and b, and x is obtained as follows. x = b / a

As described above, x is obtained for about 200 particles, and an average value thereof is defined as x (average).
Those satisfying the relationship of (average) ≧ 1.5 are flake-shaped. Preferably, 30 ≧ x (average) ≧ 1.5, and more preferably, 20 ≧ x (average) ≧ 2.0. Incidentally, the needle shape is 1 ≦ x (average) <1.5.

In the scaly particles, 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 from 0.01 μm to 0.23 μm, more preferably from 0.1 μm to 0.20 μm. c / b
Is preferably 1 to 6, more preferably 1.05 to
4, more preferably 1.1 to 3, particularly preferably 1.
1-2.

The particle size distribution of the organic silver salt is preferably monodispersed. The monodispersion is preferably 100% or less, more preferably 80% or less, and even 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 determined from a transmission electron microscope image of the organic silver salt dispersion. Another method of measuring monodispersity is to determine the standard deviation of the volume-weighted average diameter of the organic silver salt, and the percentage of the value divided by the volume-weighted average diameter (coefficient of variation)
Is preferably 80% or less, more preferably 50% or less. As a measuring method, for example, an organic silver salt dispersed in a liquid is irradiated with a laser beam, and an autocorrelation function with respect to a time change of fluctuation of the scattered light is obtained from a particle size (volume weighted average diameter) obtained. be able to.

Known methods can be applied to the production of the organic acid silver used in the present invention and its dispersion method. For example, JP-A-10-62899, European Patent Publication EP08
No. 03763A1, European Patent Publication EP962812
A1 publication can be referred to.

When a photosensitive silver salt is allowed to coexist at the time of dispersing the organic silver salt, fog increases and the sensitivity is significantly reduced.
It is 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 0.1 to 1 mol of the organic acid silver salt in the liquid.
The content is 1 mol% or less, and the photosensitive silver salt is not positively added.

[0071] In the present invention, the organic silver salt can be used in a desired amount, preferably 0.1-5 g / m ² as silver amount, more preferably from 1 to 3 g / m ^2.

The photosensitive silver halide used in the present invention is not particularly limited in terms of the halogen composition, and may be silver chloride, silver chlorobromide,
Silver bromide, silver iodobromide, silver iodochlorobromide can be used. The distribution of the halogen composition in the grains of the photosensitive silver halide may be uniform, the halogen composition may be changed stepwise, or may be changed continuously. Further, silver halide grains having a core / shell structure can be preferably used. The structure is preferably a 2- to 5-fold structure, more preferably a 2- to 5-layer structure.
Quadruplex 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 photosensitive silver halide are well known in the art and are described, for example, in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. Specifically, a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to a gelatin or other polymer solution, and then mixed with an organic silver salt. Is used. Also,
Paragraph No. 0217- of JP-A-11-119374
No. 0224, Japanese Patent Application No. 11-9870
The methods described in JP-A Nos. 8 and 11-84182 are also preferable.

The grain size of the photosensitive silver halide is preferably small in order to keep the white turbidity after image formation low, specifically, 0.20 μm or less, more preferably 0.1 μm or less.
01 μm to 0.15 μm, more preferably 0.02 μm
m to 0.12 μm. The particle size here means
It is the diameter when the projected area of a silver halide grain (projected area of a main plane in the case of a tabular grain) is converted into a circular image having the same area.

The shape of the silver halide grains may be cubic, octahedral, tabular, spherical, rod-like, potato-like or the like. In the present invention, cubic grains are particularly preferred. 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. However, the spectral sensitization efficiency when the spectral sensitizing dye is adsorbed is high. preferable. The ratio is preferably 50% or more, and 65%
The above is more preferable, and 80% or more is further preferable. The ratio of the {100} plane of the Miller index is determined by the T.V. method utilizing the dependence of the adsorption of the sensitizing dye on the {111} plane and the {100} plane. Tani; Imaging Sci. , 29,
165 (1985).

In the present invention, the hexacyano metal complex is
Silver halide grains present on the outermost surface of the particles are preferred. Six
As the cyano metal complex, [Fe (CN)₆]^Four-, [F
e (CN)₆]^3-, [Ru (CN)₆]^Four-, [Os (C
N)₆]^Four-, [Co (CN)₆] ^3-, [Rh (CN)₆]
^3-, [Ir (CN)₆]^3-, [Cr (CN)₆]^3-, [R
e (CN)₆]^3-And the like. In the present invention
Hexacyano Fe complexes are preferred.

Since the hexacyano metal complex exists in the form of ions in an aqueous solution, the counter cation is not important, but as the counter cation, it is easily miscible with water and is suitable for the precipitation operation of a silver halide emulsion. Alkali metal ions such as sodium ion, potassium ion, rubidium ion, cesium ion and lithium ion, ammonium ion, alkylammonium ion (for example, tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, tetra (n-
(Butyl) ammonium ion).

The hexacyano metal complex may be used in combination with water and a suitable water-miscible organic solvent (eg, alcohols, ethers, glycols, ketones, esters, amides, etc.) or gelatin. And can be added as a mixture.

The addition amount of the hexacyano metal complex is preferably from 1 × 10 ⁻⁵ mol to 1 × 10 ⁻² mol, more preferably from 1 × 10 ⁻⁴ mol to 1 × 10 ⁻³ mol per mol of silver. Is a mole.

In order for the hexacyano metal complex to be present on the outermost surface of the silver halide grains, the addition of the hexacyano metal complex to the silver nitrate aqueous solution used for grain formation is followed by sulfur sensitization, selenium sensitization and tellurium sensitization. It is added directly before the completion of the preparation step before the chemical sensitization step for performing noble metal sensitization such as chalcogen sensitization or gold sensitization, during the washing step, during the dispersion step, or before the chemical sensitization step. In order not to grow the silver halide fine grains, it is preferable to add the hexacyano metal complex immediately after the grain formation, and it is preferable to add the hexacyano metal complex before the completion of the charging step.

Incidentally, the addition of the hexacyano metal complex may be started after 96% by mass of the total amount of silver nitrate added for forming grains, or started after 98% by mass is added. More preferably, it is particularly preferable after adding 99% by mass.

When these hexacyano metal complexes are added after the addition of an aqueous solution of silver nitrate immediately before the completion of grain formation, they can be adsorbed on the outermost surface of silver halide grains, and most of them are hardly soluble in silver ions on the grain surface. Forms salt. Since the silver salt of hexacyanoiron (II) is a salt that is less soluble than AgI, it can be prevented from being redissolved by fine particles, and silver halide fine particles having a small particle size can be produced.

The photosensitive silver halide grains used in the present invention may contain a metal or a metal complex of Group 8 to Group 10 of the periodic table (showing Groups 1 to 18).
The metal of Group 8 to Group 10 of the periodic table or the central metal of the metal complex is preferably rhodium, ruthenium or iridium. One type of these metal complexes may be used, or two or more types of complexes of the same metal and different metals may be used in combination.
The preferred content is 1 × 10 ⁻⁹ mol to 1 × with ^respect to 1 mol of silver.
A range of 10 ^-3 mole is preferred. Regarding these metals and metal complexes and methods for adding them, see JP-A-7-2254.
No. 49, 11-65021, paragraph 001
Nos. 8-0024 and 11-119374, paragraph 0
227 to 0240.

Further, metal atoms (for example, [Fe (CN)) which can be contained in the silver halide grains used in the present invention.
₆ ] ^4- ), desalting and chemical sensitization of silver halide emulsions are described in JP-A-11-84574, paragraph number 0046.
0050, JP-A-11-65021, paragraph number 002
Paragraph No. 0 of JP-A-11-119374, 5-0031
242 to 0250.

Various gelatins can be used in the photosensitive silver halide emulsion used in the present invention. In order to maintain a good dispersion state of the photosensitive silver halide emulsion in the organic silver salt-containing coating solution, the molecular weight is preferably from 500 to 60,000.
It is preferable to use a low molecular weight gelatin of the above. These low-molecular-weight gelatins may be used at the time of grain formation or at the time of dispersion after desalting, but are preferably used at the time of dispersion after desalting.

Sensitizing dyes that can be used in the present invention are those capable of spectrally sensitizing silver halide grains in a desired wavelength region when adsorbed on silver halide grains, and are suitable for the spectral characteristics of an exposure light source. Sensitizing dyes having spectral sensitivity can be advantageously selected. For the sensitizing dye and the method of addition, see JP-A-11-65021, paragraph number 0103.
To 0109 and 10-186572.
A compound represented by the formula (I), a dye represented by the general formula (I) in JP-A-11-119374, and paragraph No. 0106;
U.S. Pat. Nos. 5,510,236 and 3,872.
Dyes described in Example 5 of JP-A No. 1,887,
Dyes disclosed in JP-A-96131 and JP-A-59-48753, and European Patent Publication EP0803764.
A1 Gazette, page 19, line 38 to page 20, page 3
5 lines, Japanese Patent Application No. 2000-86865, Japanese Patent Application No. 200
0-102560 and the like. These sensitizing dyes may be used alone or in combination of two or more. In the present invention, the time when the sensitizing dye is added to the silver halide emulsion is preferably after the desalting step and before coating, and more preferably after desalting and before the start of chemical ripening. The addition amount of the sensitizing dye in the present invention can be a desired amount in accordance with the sensitivity and the performance of fog.
^-6 to 1 mol, more preferably 10 ^-4 to 10
^-1 mole.

In the present invention, in order to improve the spectral sensitization efficiency,
Supersensitizers can be used. Examples of the supersensitizer used in the present invention include EP 587,338.
Gazette, U.S. Pat. Nos. 3,877,943 and 4,873,184, JP-A-5-341432
Gazettes, JP-A-11-109947 and JP-A-10-111
No. 543, and the like.

In the present invention, the photosensitive silver halide grains are preferably chemically sensitized by a sulfur sensitization method, a selenium sensitization method or a tellurium sensitization method. As compounds preferably used in the sulfur sensitization method, the selenium sensitization method, and the tellurium sensitization method, known compounds, for example, JP-A-7-12876
Compounds described in JP-A No. 8 and the like can be used.
Particularly in the present invention, tellurium sensitization is preferable.
Compounds described in paragraph No. 0030 of 1-65021, general formulas (II) and (II) of JP-A-5-313284.
It is more preferable to use the compounds represented by I) and (IV).

In the present invention, chemical sensitization can be performed at any time after grain formation and before coating, and after desalting, (1) before spectral sensitization, (2) simultaneously with spectral sensitization, ( 3)
After spectral sensitization, there may be (4) just before coating. In particular, it is preferably performed after spectral sensitization. The amount of the sulfur, selenium and tellurium sensitizers used in the present invention varies depending on the silver halide grains to be used, the conditions of chemical ripening, etc., but is preferably 10 ^-8 to 10 ^-2 mol, preferably 10 ^-8 mol, per mol of silver halide. It is about 10 ^-7 to 10 ^-3 mol. The conditions of the chemical sensitization in the present invention are not particularly limited.
g is 6 to 11, and the temperature is about 40 to 95 ° C. The silver halide emulsion used in the present invention includes European Patent Publication EP 29
A thiosulfonic acid compound may be added by the method disclosed in Japanese Patent No. 3,917.

As the photosensitive silver halide emulsion in the light-sensitive material used in the present invention, only one kind may be used, or two or more kinds may be used (for example, those having a different average grain size, those having a different halogen composition, those having a different crystal habit). (Different ones, different chemical sensitization conditions). The gradation can be adjusted by using a plurality of photosensitive silver halides having different sensitivities. Japanese Patent Application Laid-Open No. 57-119 discloses a technique relating to these.
No. 341, No. 53-106125, No. 47-
3929, 48-55730 and 46-
Nos. 5187, 50-73627 and 57-
No. 150841 and the like. It is preferable that the difference in sensitivity be 0.2 logE or more in each emulsion.

The amount of the photosensitive silver halide used is represented by the amount of coated silver per m ² of the photographic material, and is preferably 0.03
0.6 g / m ² , more preferably 0.05 to
0.4 g / m ² , more preferably 0.1 to 0.1 g / m ² .
4 g / m ² . The amount is preferably from 0.01 mol to 0.5 mol, more preferably from 0.02 mol to 0.3 mol, per 1 mol of the organic silver salt.

In the present invention, a photosensitive material can be produced by mixing an aqueous dispersion of an organic silver salt and an aqueous dispersion of a photosensitive silver salt. When mixing, two or more aqueous dispersions of organic silver salts and 2
Mixing an aqueous dispersion of two or more photosensitive silver salts is a method preferably used for adjusting photographic characteristics.

Regarding the mixing method and 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, a ball mill, a sand mill, a colloid mill, and a vibrator. Mills, a method of mixing with a homogenizer, etc., 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, etc. There is no particular limitation as long as the effect appears sufficiently.

In the present invention, the preferred timing of adding the photosensitive silver halide to the coating solution for the image forming layer is as follows.
The mixing time is from 80 minutes to immediately before, preferably from 60 minutes to 10 seconds, but the mixing method and mixing conditions are not particularly limited as long as the effects of the present invention are sufficiently exhibited. Specific mixing methods include a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is a desired time, Harnby, M .; F. Edwa
rds, A.R. W. There is a method using a static mixer or the like described in Chapter 8 of Nienow, "Liquid Mixing Technology" translated by Koji Takahashi (Nikkan Kogyo Shimbun, 1989).

In the present invention, the binder of the organic silver salt-containing layer may be any polymer, and suitable binders are transparent or translucent, generally colorless, and include natural resins and polymers and copolymers, synthetic resins and polymers and Copolymers and other film-forming media such as gelatins, rubbers, poly (vinyl alcohol)
, Hydroxyethylcellulose, cellulose acetate, cellulose acetate butyrate, poly (vinylpyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (Methacrylic acid) s, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers, styrene-butadiene copolymers, poly (vinyl acetal) s (for example, poly (vinyl formal) and poly (vinyl) Butyral)), poly (ester) s, poly (urethane) s, phenoxy resins, poly (vinylidene chloride) s, poly (epoxides), poly (carbonates), poly (vinyl acetate) s, poly (olefins) , Cellulose esters, poly (amide)
Kind. The binder may be coated from water or an organic solvent or emulsion.

In the present invention, the organic silver salt-containing layer is coated using a coating solution in which 30% by mass or more of the solvent is water,
When formed by drying, the binder of the organic silver salt-containing layer is soluble or dispersible in an aqueous solvent (aqueous solvent),
In particular, a latex made of a polymer having an equilibrium water content of 2% by mass or less at 25 ° C. and a relative humidity of 60% is preferable. The most preferred form is prepared so that the ionic conductivity is 2.5 mS / cm or less. As such a preparation method, a method of purifying using a separation functional membrane after polymer synthesis can be mentioned.

The aqueous solvent in which the binder is soluble or dispersible is water or a mixture of water and 70% by mass or less of a water-miscible organic solvent. Examples of the water-miscible organic solvent include, for example, alcohol solvents such as methyl alcohol, ethyl alcohol, and propyl alcohol; cellosolve solvents such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; ethyl acetate; and dimethylformamide. it can.

[0098] The term "aqueous solvent" is also used herein in the case where the polymer is not thermodynamically dissolved but exists in a so-called dispersed state.

The “equilibrium moisture content at 25 ° C. and 60% relative humidity” is defined as the mass W ^{1 of the} polymer in humidity control equilibrium in an atmosphere of 25 ° C. and 60% relative humidity and the weight of the polymer in a completely dry state at 25 ° C. It can be expressed as follows using the mass W ⁰ . Equilibrium water content at 25 ° C. and 60% relative humidity = ｛(W ¹ −
W ⁰ ) / W ⁰ ｝ × 100 (% by mass)

The definition and measurement method of the water content can be referred to, for example, Polymer Engineering Course 14, Polymer Material Testing Method (edited by the Society of Polymer Science, Jinjinshokan).

25 of the binder polymer used in the present invention
The equilibrium moisture content at 60 ° C. and 60% relative humidity is preferably 2
% By mass or less, more preferably 0.01% by mass or less.
1.5% by mass, more preferably 0.02% by mass
１1% by mass.

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 water-insoluble hydrophobic 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. The average particle size of the dispersed particles is preferably 1 to 50,000 nm,
More preferably, it is about 5 to 1000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.

In the present invention, the polymer dispersible in an aqueous solvent is preferably an acrylic polymer, a poly (ester), a rubber (for example, an SBR resin), a poly (urethane), a poly (vinyl chloride), Hydrophobic polymers such as poly (vinyl acetate) s, poly (vinylidene chloride) s, and poly (olefins) are exemplified. These polymers may be a linear polymer, a branched polymer, a crosslinked polymer, 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. These polymers have a number average molecular weight of 5,000 to 1,000,000, preferably 1,000.
0 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.

Specific examples of preferable polymer latex include the following. In the following, the raw material monomers are used, and the numerical value in parentheses is% by mass, and the molecular weight is the number average molecular weight.

P-1; -MMA (70) -EA (27)
-MAA (3)-latex (molecular weight 37000) P-2; -MMA (70) -2EHA (20) -St
Latex of (5) -AA (5)-(molecular weight 4000
0) P-3; -St (50) -Bu (47) -MAA (3)
-Latex (molecular weight 45000) P-4; -St (68) -Bu (29) -AA (3)-
Latex (molecular weight 60000) P-5; -St (71) -Bu (26) -AA (3)-
Latex (molecular weight 60000) P-6; -St (70) -Bu (27) -IA (3)-
Latex (molecular weight 120,000) P-7; -St (75) -Bu (24) -AA (1)-
Latex (molecular weight 108000) P-8; -St (60) -Bu (35) -DVB (3)
Latex of -MAA (2)-(molecular weight 150,000) P-9; -St (70) -Bu (25) -DVB (2)
-AA (3)-latex (molecular weight 280000) P-10; -VC (50) -MMA (20) -EA (2
Latex of 0) -AN (5) -AA (5)-(molecular weight: 80000) P-11; -VDC (85) -MMA (5) -EA
Latex of (5) -MAA (5)-(molecular weight 6700
0) Latex of P-12; -Et (90) -MAA (10)-(molecular weight 12000) P-13; -St (70) -2EHA (27) -AA
Latex of (3) (molecular weight 130000) P-14; -MMA (63) -EA (35) -AA
Latex of (2) (molecular weight 33000)

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

The polymer latex described above is commercially available, and the following polymers can be used. Examples of acrylic polymers include Sebian A-463.
5, 46583, 4601 (all produced by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 82
1, 820, 857 (Nippon Zeon Co., Ltd.), etc.
Examples of poly (esters) include FINETEX E
Examples of poly (urethane) s such as S650, 611, 675, and 850 (all manufactured by Dainippon Ink and Chemicals, Inc.), WD-size, and WMS (all manufactured by Eastman Chemical) include HYDRAN AP10, 20, 30, Examples of rubbers such as 40 (all manufactured by Dainippon Ink and Chemicals, Inc.) include LACSTAR 7310K, 3307B, 470
0H, 7132C (Dai Nippon Ink Chemical Co., Ltd.)
Nipol Lx416, 410, 438C, 2
Examples of poly (vinyl chloride) s such as 507 (both manufactured by Zeon Corporation) include G351 and G576 (both manufactured by Zeon Corporation); examples of poly (vinylidene chloride) s include L502; L513 (Asahi Kasei Corporation)
Examples of poly (olefins) such as Chemipearl S120, SA100 (Mitsui Petrochemical Co., Ltd.)
Manufactured).

These polymer latexes may be used alone, or may be used in combination of two or more as required.

The polymer latex used in the present invention is particularly preferably a styrene-butadiene copolymer latex. The mass ratio of the styrene monomer unit to the butadiene monomer unit in the styrene-butadiene copolymer is preferably from 40:60 to 95: 5. The proportion of the copolymer of styrene monomer units and butadiene monomer units is 60 to 99% by mass.
It is preferred that The preferred molecular weight range is the same as described above.

The latex of the styrene-butadiene copolymer preferably used in the present invention includes the aforementioned P-3
~ P-8, commercially available LACSTAR-3307B,
7132C, Nipol Lx416 and the like.

The glass transition temperature (Tg) of the polymer preferably used for the binder used in the present invention is preferably 1
It is 0 to 80 degreeC, More preferably, it is 15 to 70 degreeC, More preferably, it is 20 to 60 degreeC. When two or more polymers having different Tg are blended and used as the binder, it is preferable that the weight average Tg falls within the above range.

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

The organic silver salt-containing layer (that is, the image forming layer) of the present invention is preferably formed using a polymer latex. The amount of the binder in the organic silver salt-containing layer is preferably such that the mass ratio of total binder / organic silver salt is 1/10 to 10
/ 1, more preferably 1/5 to 4/1.

The organic silver salt-containing layer is usually a photosensitive layer (emulsion layer) containing a photosensitive silver halide, which is a photosensitive silver salt. / Mass ratio of silver halide is preferably from 400 to
5, more preferably 200 to 10.

In the present invention, the total amount of the binder in the image forming layer is preferably from 0.2 to 30 g / m ² , more preferably from 1 to 15 g / m ² . A crosslinking agent for crosslinking and a surfactant for improving coating properties may be added to the image forming layer.

In the present invention, the solvent of the coating solution for the organic silver salt-containing layer (here, for simplicity, the solvent and the dispersion medium are collectively referred to as a solvent) is preferably an aqueous solvent containing 30% by mass or more of water. As a component other than water, any water-miscible organic solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate may be used. The water content of the solvent in the coating liquid is preferably 50% by mass or more, and more preferably 70% by mass or more. Examples of preferred solvent compositions include water, water / methyl alcohol = 90/10, water / methyl alcohol = 70/30, water / methyl alcohol / dimethylformamide = 80/1, in addition to water.
5/5, water / methyl alcohol / ethyl cellosolve = 8
5/10/5, water / methyl alcohol / isopropyl alcohol = 85/10/5, etc. (numerical values are% by mass).

The antifoggant, stabilizer and stabilizer precursor which can be used in the present invention are described in
No. 62899, paragraph number 0070, European Patent Publication E
P0803764A1, page 20, line 57-second
What is disclosed on page 1, line 7 is mentioned. The antifoggant preferably used in the present invention is an organic halide, which is disclosed in JP-A-11-65021.
And Japanese Patent Application Laid-Open No. H11-11212. In particular, an organic halogen compound represented by the formula (P) in Japanese Patent Application No. 11-87297,
An organic polyhalogen compound represented by the general formula (II) of 339934 is preferable.

In the present invention, as an antifoggant,
It is preferable to use a polyhalogen compound substantially not containing a mercury compound and represented by the general formula (III).
In the general formula (III), Q represents an alkyl group, an aryl group or a heterocyclic group; Y represents a divalent linking group;
Represents 0 or 1, Z ¹ and Z ² each independently represent a halogen atom, and X represents a hydrogen atom or an electron-withdrawing group. The alkyl group, aryl group or heterocyclic group represented by Q may have a substituent. General formula (III)
In the formula, Q preferably represents a phenyl group substituted by an electron-withdrawing group having a positive Hammett σp. Specific examples of the electron-withdrawing group as a substituent include a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a sulfoxide group, an acyl group, a heterocyclic group, Examples include a halogen atom, a halogenated alkyl group, and a phosphoryl group. The σp value is preferably 0.2 to 2.0, more preferably 0.4 to 2.0.
1.0. Particularly preferred electron-withdrawing groups are a carbamoyl group, an alkoxycarbonyl group, an alkylsulfonyl group, and an alkylphosphoryl group, with a carbamoyl group being most preferred.

Specific examples of the polyhalogen compound represented by the general formula (III) are shown below, but the compounds usable in the present invention are not limited to these.

[0120]

Embedded image

[0121]

Embedded image

[0122]

Embedded image

In the present invention, as a method for incorporating the antifoggant into the photothermographic material, the above-mentioned method for incorporating the reducing agent into the photosensitive material can be mentioned. The antifoggant is also added as a solid fine particle dispersion. Is preferred.

Other antifoggants include those described in JP-A-11
No. 65021, paragraph 0113, mercury (II)
Salts, benzoic acids in paragraph number 0114 of the same publication,
-87297, a salicylic acid derivative represented by the formula (Z), Japanese Patent Application No. 11-23995, a formalin scavenger compound represented by the formula (S);
-352624, a triazine compound according to claim 9, a compound represented by general formula (III) in JP-A-6-11791, 4-hydroxy-6-methyl-1,3,3.
3a, 7-tetrazaindene and the like.

The photothermographic material of the present invention may contain an azolium salt for the purpose of preventing fog. Examples of the azolium salt include compounds represented by the general formula (XI) described in JP-A-59-193449, JP-B-55-12581.
And compounds represented by the general formula (II) described in JP-A-60-153039. 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 photosensitive 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, it may be at any time during the preparation of the coating solution from the preparation of the organic silver salt. It is preferable to apply it immediately after the application. The azolium salt may be added by any method such as a powder, a solution, and a 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 to 2 mol, more preferably 1 × 10 ⁻³ mol to 0.5 mol per mol of silver.

The photothermographic material of the present invention may contain mercapto for controlling development by suppressing or accelerating development, improving spectral sensitization efficiency, and improving storage stability before and after development. Compounds, disulfide compounds, and thione compounds can be contained. A specific example is described in paragraph No. 0 of JP-A-10-62899.
067 to 0069, compounds represented by the general formula (I) in JP-A-10-186572, and paragraphs [0033] to [0052] as specific examples thereof, and European Patent Publication EP080.
No. 3764A1, page 20, lines 36 to 56, and Japanese Patent Application No. 11-273670.
Among them, mercapto-substituted heteroaromatic compounds are preferred.

In the photothermographic material of the present invention, it is preferable to add a toning agent. Regarding the color toning agent, see JP-A-10-6289.
No. 9, paragraphs 0054 to 0055, European Patent Publication No. EP0803764A1, page 21, page 23 to 23.
48, JP-A-2000-35631, and particularly, phthalazinones (phthalazinone, phthalazinone derivative or metal salt; for example, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-
Dimethoxyphthalazinone and 2,3-dihydro-1,
4-phthalazinedione); a combination of phthalazinones and phthalic acids (eg, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride); phthalazines (phthalazine, phthalazine derivative or metal salt; 4- (1-naphthyl) phthalazine,
6-isopropylphthalazine, 6-t-butylfuratazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine); a combination of phthalazines and phthalic acids is preferred, and phthalazine is particularly preferred. Combinations of phthalates and phthalic acids are preferred.

In the present invention, plasticizers and lubricants usable in the photosensitive layer are described in JP-A-11-6.
JP-A No. 5021, paragraph No. 0117, ultra-high contrast agent for forming a super-high contrast image, and its addition method and amount are described in the same paragraph No. 0118, JP-A No. 11-223898, paragraph Nos. 0136 to 0193, and Japanese Patent Application No. Hei. 11-87297
(H), compounds of formulas (1) to (3), compounds of general formulas (A) and (B), and general formulas (III) to (V) described in Japanese Patent Application No. 11-91652. (Specific compounds: Chemical formulas 21 to 24) and a contrast enhancement accelerator are described in JP-A No. 11-65021, paragraph number 0102, and JP-A No. 11-65021.
No. 223898, paragraphs 0194-0195.

In order to use formic acid or formate as a strong fogging substance, the side having the image forming layer containing the photosensitive silver halide is not more than 5 mmol, more preferably not more than 5 mmol per mol of silver.
It is preferred that the content be contained in millimoles or less.

When a super-high contrast agent is used in the photothermographic material of the present invention, it is preferable to use an acid formed by hydration of diphosphorus pentoxide or a salt thereof in combination. Acids or salts thereof formed by hydration of diphosphorus pentoxide include metaphosphoric acid (salt), pyrophosphoric acid (salt), orthophosphoric acid (salt), triphosphoric acid (salt), tetraphosphoric acid (salt), hexametaline Acid (salt)
And the like. Particularly preferred are orthophosphoric acid (salt) and hexametaphosphoric acid (salt). Specific salts include sodium orthophosphate, sodium dihydrogen orthophosphate, sodium hexametaphosphate, ammonium hexametaphosphate and the like. The amount of phosphorus pentoxide acid or a salt formed by hydration (coating amount per photographic material 1 m ²⁾ may but a desired amount depending on the performance such as sensitivity and fog, 0.1 to 500 mg / M ²
Is preferable, and 0.5 to 100 mg / m ² is more preferable.

The photothermographic material of the present invention can be provided with a surface protective layer for the purpose of preventing adhesion of the image forming layer. The surface protective layer may be a single layer or a plurality of layers. The surface protective layer is described in JP-A-11-65021, paragraphs 0119 to 0120. Gelatin is preferred as the binder for the surface protective layer,
It is also preferable to use polyvinyl alcohol (PVA). As gelatin, inert gelatin (for example, Nitta Gelatin 750), phthalated gelatin (for example, Nitta Gelatin 801) and the like can be used. As the PVA, completely saponified PVA-105, partially saponified P
VA-205, PVA-335, MP-203 of modified polyvinyl alcohol (the above are trade names manufactured by Kuraray Co., Ltd.)
And the like. The polyvinyl alcohol coating amount (per 1 m ^{2 of the} support) of the protective layer (per layer) includes:
0.3-4.0 g / m ² is preferred, and 0.3-2.0 g
/ M ² is more preferred.

When the photothermographic material of the present invention is used particularly for printing in which dimensional change is a problem, it is preferable to use a polymer latex for the surface protective layer and the back layer.
For such polymer latex, see "Synthetic Resin Emulsion (edited by Tadashi Okuda and Hiroshi Inagaki, published by Kobunshi Kanko (1978))", "Application of Synthetic Latex (Edited by Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, Published by the Society of Polymer Publishing (1993)), "Synthesis of Synthetic Latex (Souichi Muroi, published by the Society of Polymer Publishing (1970))" and the like, and specifically, methyl methacrylate (33.5)
Mass%) / ethyl acrylate (50% by mass) / latex of methacrylic acid (16.5% by mass) copolymer, methyl methacrylate (47.5% by mass) / butadiene (47.5% by mass) / itaconic acid (5% by mass) A) latex of copolymer, latex of copolymer of ethyl acrylate / methacrylic acid, methyl methacrylate (5
8.9% by mass) / 2-ethylhexyl acrylate (2
5.4 mass%) / styrene (8.6 mass%) / 2-hydroxyethyl methacrylate (5.1 mass%) / latex of acrylic acid (2.0 mass%) copolymer, methyl methacrylate (64.0 mass%) ) / Styrene (9.0
Mass%) / butyl acrylate (20.0 mass%) /
2-hydroxyethyl methacrylate (5.0% by mass)
/ Acrylic acid (2.0 mass%) copolymer latex. Further, as a binder for the surface protective layer, a combination of a polymer latex described in Japanese Patent Application No. 11-6872, Japanese Patent Application No. 11-143058, and the like.
Technology described in paragraph numbers 0021 to 0025 of the specification,
Paragraph Nos. 0027-0 of Japanese Patent Application No. 11-6872.
028, and the techniques described in paragraphs 0023 to 0041 of JP-A-2000-16409 may be applied. The ratio of the polymer latex in the surface protective layer is preferably from 10% by mass to 90% by mass of the whole binder, particularly
0 mass%-80 mass% is preferable. The amount of the binder (including the water-soluble polymer and the latex polymer) applied to the surface protective layer (per layer) (per 1 m ^{2 of the} support) is as follows:
Preferably it is 0.3-5.0 g / m < ² >, More preferably, it is 0.3-2.0 g / m < ² >.

In the present invention, the preparation temperature of the coating solution for the image forming layer is preferably 30 ° C. to 65 ° C., more preferably 35 ° C. to less than 60 ° C., and further preferably 35 ° C.
５５55 ° C. Further, the temperature of the image forming layer coating solution immediately after the addition of the polymer latex is preferably maintained at 30 ° C to 65 ° C. Preferably, the reducing agent and the organic silver salt are mixed before the addition of the polymer latex.

In the present invention, the image forming layer is composed of one or more layers on a support. When it is composed of one layer, it consists of an organic silver salt, a light-sensitive silver halide, a reducing agent and a binder, and optionally contains additional materials such as a toning agent, a coating auxiliary and other auxiliary agents. When it is composed of two or more layers, the first image forming layer (usually a layer adjacent to the support) contains an organic silver salt and a photosensitive silver halide, and the second image forming layer or both layers contain Or other ingredients must be included. The construction of a multicolor photothermographic material may include a combination of these two layers for each color, and all in a single layer as described in US Pat. No. 4,708,928. May be included. In the case of a multi-dye, multi-color photosensitive heat-developable photographic material, each emulsion layer is generally comprised of US Pat.
As described in U.S. Pat. No. 1, the use of a functional or non-functional barrier layer between each photosensitive layer keeps them distinct from each other.

In the present invention, the photosensitive layer has an improved color tone,
From the viewpoint of preventing interference fringes during laser exposure and irradiation, various dyes and pigments (for example, CI Pig
ment blue 60, C.I. I. Pigment
Blue 64, C.I. I. Pigment Blue
15: 6) can be used. These are described in International Publication WO 98/36322, Japanese Patent Laid-Open No. 10-26.
Nos. 8465, 11-338098 and the like.

In the photothermographic material of the present invention, an antihalation layer can be provided on the side farther from the light source than the photosensitive layer.

The photothermographic material generally has a non-photosensitive layer in addition to the photosensitive layer. The non-photosensitive layer may be arranged in such a manner that (1) a protective layer provided on the photosensitive layer (farther than the support), (2) between a plurality of photosensitive layers or between the photosensitive layer and the protective layer. , An undercoat layer provided between the photosensitive layer and the support, and a back layer provided on the opposite side of the photosensitive layer. The filter layer is
It is provided on the photosensitive material as the layer (1) or (2).
The antihalation layer is provided on the photosensitive material as the layer (3) or (4).

The antihalation layer is disclosed in
JP-A-1-65021, paragraphs 0123 to 0124, JP-A-11-223898, JP-A-9-230531, JP-A-10-36695, and JP-A-10-10478.
No. 9, No. 11-231457, No. 11-35
No. 2625, No. 11-352626, and the like. The antihalation layer contains an antihalation dye having absorption at the exposure wavelength. When the exposure wavelength is in the infrared region, an infrared absorbing dye may be used, and in that case, a dye having no absorption in the visible region is preferable. When using a dye having absorption in the visible region to prevent halation, it is preferable that substantially no color of the dye remains after image formation, and a means for decoloring by the heat of heat development is used. Is preferred. In particular, it is preferable to add a thermal decoloring dye and a base precursor to the non-photosensitive layer to function as an antihalation layer. These techniques are described in, for example, JP-A-11-231457.

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 0.00
It is about 1 to 1 g / m ² .

When the dye is decolored in this manner, the optical density after thermal development can be reduced to 0.1 or less. Two or more decoloring dyes may be used in combination. Similarly,
Two or more base precursors may be used in combination. In the thermal decoloring using such a decolorizing dye and a base precursor, when mixed with a base precursor as described in JP-A-11-352626, the melting point becomes 3 ° C (deg).
The substance to be lowered (for example, diphenylsulfone,
It is preferable to use 4-chlorophenyl (phenyl) sulfone) in combination from the viewpoint of thermal discoloration and the like.

In the present invention, a colorant having an absorption maximum at 300 to 450 nm can be added for the purpose of improving the silver tone and the aging of the image. Such colorants are disclosed in JP-A-62-210458 and 63-104.
046, 63-103235, 63-103
JP-A-208846, JP-A-63-306436, JP-A-63-314535, JP-A No. 01-61745, and Japanese Patent Application No. 11-276751 describe it. Such a colorant is usually 0.1 mg / m
It is added in the range of ^{2 to 1} g / m ² , and the layer to be added is preferably a back layer provided on the opposite side of the photosensitive layer.

The photothermographic material of the present invention is a so-called one-sided photosensitive material having at least one photosensitive 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 for improving transportability.
JP-A-11-65021, paragraph numbers 0126 to 01
27. The amount of the matting agent used is preferably 1 to 4 when indicated in the amount of coating per m ² of the light-sensitive material.
00 mg / m ² , more preferably 5 to 300 mg
/ M ² . The matte degree of the surface of the image forming layer may be any value as long as stardust failure does not occur, but the Beck smoothness is preferably 30 seconds to 2000 seconds, and particularly preferably 40 seconds to 1500 seconds. The Beck smoothness is determined by Japanese Industrial Standards (JIS) P8119 “Smoothness test method of paper and paperboard with Beck tester” and TAPPI standard method T47.
9 can be easily obtained.

In the present invention, the matting degree of the back layer is preferably 10 to 1200 seconds, more preferably 20 to 800 seconds, even more preferably 40 to 500 seconds.

In the present invention, the matting agent is preferably contained in the outermost surface layer of the light-sensitive material, a layer functioning as the outermost surface layer, or a layer close to the outer surface. It is preferable to be contained.

The back layer applicable to the present invention is described in paragraph No. 01 of JP-A-11-65021.
28-0130.

The photothermographic material of the present invention preferably has a pH of 6.0 or less, more preferably 5.5 or less, before heat development. The lower limit is not particularly limited, but is about 3. For adjusting the film surface pH, it is preferable to use an organic acid such as a phthalic acid derivative, a nonvolatile acid such as sulfuric acid, or a volatile base such as ammonia from the viewpoint of reducing the film surface pH. In particular, ammonia is preferable for achieving a low film surface pH since ammonia is easily volatilized and can be removed before the application step and the heat development. The method of measuring the film surface pH is described in paragraph No. 0123 of Japanese Patent Application No. 11-87297.

In the present invention, a hardener may be used for each layer such as a photosensitive layer, a protective layer and a back layer. Examples of hardeners include T.I. H. "THE THEORY OF THE PHOT" by James
OGRAPHIC PROCESS FOURTH EDITION "(Macmill
an PublishingCo. , Inc. Published, 1
977), pp. 77-87, including chrome alum, 2,4-dichloro-6-hydroxy-
s-Triazine sodium salt, N, N-ethylenebis (vinylsulfoneacetamide), N, N-propylenebis (vinylsulfoneacetamide), ibid.
Polyvalent metal ions described on page 8, etc., US Pat. No. 4,28
Polyisocyanates such as those described in U.S. Pat. No. 4,791,0
No. 42, etc .;
Vinylsulfone-based compounds such as 9048 are preferably used.

The hardener is added as a solution, and the time for adding this solution to the coating solution for the protective layer is from 180 minutes before coating.
Immediately before, preferably before 60 minutes to 10 seconds, the mixing method and mixing conditions are not particularly limited as long as the effects of the present invention are sufficiently exhibited. Specific mixing methods include a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is a desired time, Harnby, M .; F. Edwar
ds, A.D. W. There is a method using a static mixer or the like described in Chapter 8 of Nienow, "Liquid Mixing Technology" translated by Koji Takahashi (Nikkan Kogyo Shimbun, 1989).

The surfactant applicable to the present invention is described in paragraph No. 0132 of JP-A-11-65021.
Paragraph 0133 of the same publication for the solvent, paragraph 0134 of the same publication for the support, paragraph 0135 of the same publication for the antistatic or conductive layer, paragraph 0136 of the same publication for the method of obtaining a color image, and JP-A-11-84573, paragraph numbers 0061 to 0
064 and Japanese Patent Application No. 11-106881, paragraph number 0
049-0062.

The transparent support is subjected to a heat treatment at a temperature in the range of 130 to 185 ° C. in order to alleviate the internal strain remaining in the film at the time of biaxial stretching and to eliminate the heat shrinkage distortion generated during the heat development processing. Polyester, especially polyethylene terephthalate, is preferably used. In the case of a photothermographic material for medical use, the transparent support is a blue dye (for example,
Dye-1 described in Examples of JP-A-8-240877-1)
And may be uncolored. Examples of the support include a water-soluble polyester described in JP-A-11-84574, a styrene-butadiene copolymer described in JP-A-10-186565, and a chloride described in Paragraph Nos. 0063 to 0080 in Japanese Patent Application No. 11-106681. It is preferable to apply an undercoating technique such as a vinylidene copolymer. The antistatic layer or undercoat is described in
No. 143430, No. 56-143431,
JP-A-58-62646, JP-A-56-120519, and Paragraph No. 0040 of JP-A-11-84573.
~ 0051, U.S. Patent No. 5,575,957,
Paragraph number 0078 of JP-A-11-223898
The technology described in 0084 can be applied.

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

The photothermographic material of the present invention may further contain an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber or a coating aid. Various additives are added to either the photosensitive layer or the non-photosensitive layer. These are described in International Publication WO98 / 36322, European Patent Publication EP8037674A, Japanese Patent Application Laid-Open No. 10-1865.
Nos. 67 and 10-18568 can be referred to.

The photothermographic material of the present invention may be applied and prepared by any method. Specifically, extrusion coating, slide coating, curtain coating, dip coating, knife coating,
Flow coating or US Pat. No. 2,681,2
Various coating operations, such as extrusion coating using a hopper of the type described in U.S. Pat.
tephen F. Kistler, Peter
M. "LIQUID FILM COATING" by Schweizer
(CHAPMAN & HALL, 1997) 3
Extrusion coating or slide coating described on pages 99 to 536 are preferably used,
Particularly preferably, slide coating is used. An example of the shape of a slide coater used for slide coating is shown in FIG. 1. If desired, ibid., Pages 399 to 536
Two or more layers can be coated simultaneously by the methods described on the page, U.S. Pat. No. 2,761,791 and GB 837,095.

The coating solution for the organic silver salt-containing layer in the present invention comprises:
It is preferably a so-called thixotropic fluid. The thixotropic property refers to a property in which the viscosity decreases as the shear rate increases. Although any apparatus may be used for the viscosity measurement, an RFS fluid spectrometer manufactured by Rheometrics Far East Co., Ltd. is preferably used, and the viscosity is measured at 25 ° C. Here, the coating solution of the organic silver salt-containing layer in the present invention preferably has a viscosity of 400 mPa · s to 100,000 mPa · s at a shear rate of 0.1 S ⁻¹ , and more preferably 500 mPa · s to 100 mPa · s.
20,000 mPa · s. Also, a shear rate of 100
At 0S ^-1 , the pressure is preferably 1 mPa · s to 200 mPa · s, more preferably 5 mPa · s to 8 mPa · s.
0 mPa · s.

Various types of systems exhibiting thixotropic properties are known, and are described in, for example, “Lecture / Rheology” edited by Polymer Publishing Association, “Polymer Latex”, published by Muroi and Morino (published by Polymer Publishing Association). 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 use an alkali thickener, and to use a surfactant.

The technology that can be used for the photothermographic material of the present invention is described in European Patent Publication EP803376A1.
Patent Publication, European Patent Publication EP 883022 A1, International Publication WO 98/36322, JP-A-56-62.
648, 58-62644, and JP-A-9-628.
Nos. 281637 and 9-297367, 9
JP-A-304869, JP-A-9-31405, JP-A-9-329865, JP-A-10-10669,
JP-A-10-62899, JP-A-10-69023, JP-A-10-186568, and JP-A-10-90823
Gazettes, JP-A-10-171063, and JP-A-10-186
No. 565, No. 10-186567, No. 10-
Nos. 186569 to 10-186572, 10-197974, 10-197982, 10-199833, 10-19798
Nos. 5 to 10-197987 and 10-20
Nos. 7001, 10-207004, 10
-221807, 10-282601,
JP-A-10-288823, JP-A-10-288824, JP-A-10-307365, and JP-A-10-3120
No. 38, No. 10-339934, No. 11-7
No. 100, No. 11-15105, No. 11-2
Nos. 4200, 11-24201, 11-
Nos. 30832 and 11-84574 and 11
JP-65021, JP-A-11-109947, JP-A-11-125880, JP-A-11-129629, JP-A-11-133536 to JP-A-11-13353.
Nos. 9 and 11-133542 and 11-13
3543, 11-2223898, 11
The technique described in JP-A-352627 is also used.

The photothermographic material of the present invention may be developed by any method. Generally, the photothermographic material exposed imagewise is heated and developed. A preferred development temperature is 80 to 250 ° C, more preferably 100 to 1 ° C.
40 ° C. The development time is preferably 1 to 180 seconds, and is preferably 1 to 180 seconds.
The time is more preferably 0 to 90 seconds, particularly preferably 10 to 40 seconds.

As a method of the heat development, a plate heater method is preferable. As a heat development method using a plate heater method, a method described in JP-A-11-133572 is preferable, and a visible image is formed by bringing a photothermographic material having a latent image formed thereon into contact with a heating means in a heat development section. A heat developing device, wherein the heating means comprises a plate heater,
A plurality of pressing rollers are provided to face each other along one surface of the plate heater, and the photothermographic material is passed between the pressing roller and the plate heater to perform thermal development. This is a heat developing device. The plate heater is divided into 2 to 6 stages, and the tip is 1 to 10
It is preferable to lower the temperature by about ° C. Such a method is also described in JP-A-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 heating of the photosensitive material can also be suppressed.

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

As a medical laser imager having an exposure section and a heat development section, Fuji Medical Dry Laser Imager FM-DPL can be mentioned. Regarding FM-DPL, Fuji Medic
al Review No. 8, page 39-55
It goes without saying that those techniques are applied as a laser imager for the photothermographic material of the present invention. It can also be applied as a photothermographic material for laser imagers in "AD network" proposed by Fuji Medical System as a network system conforming to the DICOM standard.

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
It is preferably used as a photothermographic material for use.

[0163]

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

Example 1 << Polyethylene terephthalate having an undercoat layer (PE
T) Preparation of Support> (Preparation of PET Support) Using terephthalic acid and ethylene glycol, an intrinsic viscosity of 0.66 (phenol-
(Measured at 25 ° C. in 6/4 (mass ratio)). After pelletizing this, 13
It was dried at 0 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, and quenched to prepare an unstretched film having a thickness of 175 μm after heat setting.

This is performed by using rolls having different peripheral speeds.
The film was stretched longitudinally 3.3 times at 0 ° C.
The film was stretched 4.5 times at 30 ° C. Then, at 240 ° C, 2
After heat setting for 0 seconds, the film was relaxed 4% in the horizontal direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling is performed on both ends, and the tenter is wound up at 4 kg / cm ² and has a thickness of 1 kg / cm ^2.
A roll-shaped PET support of 75 μm was obtained.

(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, 0.375 kV was applied to the support.
-It turned out that the processing of A * minute / m < ² > was performed.
The processing frequency at this time is 9.6 kHz, and the electrode and the dielectric
The gap clearance of the shell was 1.6 mm.

(Preparation of PET Support Having Undercoat Layer) (1) Preparation of Undercoat Layer Coating Solution Formulation 1 for Undercoat Layer Coating Solution (for Undercoat Layer on Photosensitive Layer Side) Pesresin A-515GB manufactured by Takamatsu Yushi Co., Ltd. (30 mass% solution) 234 g polyethylene glycol monononyl phenyl ether (average ethylene oxide number = 8.5) 10 mass% solution 21.5 g MP-1000 manufactured by Soken Chemical Co., Ltd. (polymer fine particles, average particle size 0.4 μm) 0 .91g distilled water 744ml

Undercoat Layer Coating Liquid Formulation 2 (for Back Layer First Layer) Styrene-butadiene copolymer latex 158 g (solid content 40% by mass, styrene / butadiene mass ratio = 68/32) 2,4-dichloro-6 -Hydroxy-S-triazine sodium salt (8% by mass aqueous solution) 20 g 1% by mass aqueous solution of sodium laurylbenzenesulfonate 10 ml Distilled water 854 ml

Undercoat Layer Coating Liquid Formulation 3 (for Back Side Second Layer) SnO ₂ / SbO (9/1 mass ratio, average particle size 0.038 μm, 17 mass% dispersion) 84 g gelatin (10 mass% aqueous solution) ) 89.2g Shin-Etsu Chemical Co., Ltd. Metrolose TC-5 (2% by mass aqueous solution) 8.6g Soken Chemical Co., Ltd. MP-1000 0.01g 1% by mass aqueous solution of sodium dodecylbenzenesulfonate 10ml NaOH (1 mass%) %) 6 ml Proxel (manufactured by ICI) 1 ml distilled water 805 ml

(2) Preparation of PET support having undercoat layer On one surface (photosensitive layer surface) of the corona-treated PET support obtained above, the undercoat layer coating liquid formulation 1 was coated with a wire bar. 6.6ml / m ² (per side)
And dried at 180 ° C. for 5 minutes. Then, on the back surface (back surface), apply the undercoat layer coating solution formulation 2 with a wire bar so that the wet coating amount is 5.7 ml / m ^2. The composition was dried at 180 ° C. for 5 minutes, and the undercoat layer coating liquid formulation 3 was coated on the back surface with a wire bar so that the wet coating amount was 7.7 ml / m ^2. For 6 minutes to prepare an undercoat support.

<< Preparation of Back Surface Coating Solution >><< Preparation of Antihalation Layer Coating Solution >> (1) Preparation of Solid Precursor Dispersion Solution (a) of Base Precursor 64 g of base precursor compound 11, 28 g of diphenylsulfone, and Kao ( Surfactant Demol N 10 g was mixed with 220 ml of distilled water, and the mixed solution was dispersed in beads using a sand mill (1/4 Gallon Sand Grinder Mill, manufactured by Imex Co., Ltd.) to give a base precursor having an average particle diameter of 0.2 μm. A solid fine particle dispersion (a) of the compound was obtained.

(2) Preparation of Dye Solid Fine Particle Dispersion 9.6 g of cyanine dye compound 13 described below and 5.8 g of sodium P-dodecylbenzenesulfonate were mixed with 305 ml of distilled water, and the mixture was sand milled (1/4 Ga).
llon sand grinder mill, Imex Co., Ltd.
) To obtain a dispersion of fine solid dye particles having an average particle diameter of 0.2 μm.

(3) Preparation of coating solution for antihalation layer 17 g of gelatin, 9.6 g of polyacrylamide, 70 g of solid fine particle dispersion (a) of base precursor obtained in (1), dye solid obtained in (2) 56 g of a fine particle dispersion, 1.5 g of monodispersed polymethyl methacrylate fine particles (average particle size: 8.0 μm), 0.03 g of benzoisothiazolinone, 2.2 g of sodium polyethylene sulfonate, 0.2 g of a blue dye compound 14 described below, and 0.2 g of the following. 3.9 g of yellow dye compound 15 and 844 ml of water were mixed,
An antihalation layer coating solution was prepared.

<< Preparation of Back Surface Protective Layer Coating Solution >>
The mixture was kept at 0 ° C., and gelatin 50 g, polystyrene sodium sulfonate 0.2 g, N, N-ethylenebis (vinylsulfoneacetamide) 2.4 g, sodium t-octylphenoxyethoxyethaneethanesulfonate 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 Na6
4 mg, 8.8 g of acrylic acid / ethyl acrylate copolymer (copolymerization mass ratio 5/95), 0.6 g of Aerosol OT (manufactured by American Cyanamid Co.), 1.8 g of liquid paraffin emulsion as liquid paraffin, 950m of water
to prepare a back surface protective layer coating solution.

<< Preparation of Silver Halide Mixed Emulsion A >> (1) Preparation of Silver Halide Emulsion 1 A 1% by mass potassium bromide solution in 1,421 ml of distilled water 3.1.
Then, 0.5 mol / L sulfuric acid was added to the mixture.
While stirring the liquid to which 5 ml and 31.7 g of phthalated gelatin were added in a stainless steel reaction bottle, the liquid temperature was maintained at 34 ° C., distilled water was added to 22.22 g of silver nitrate, and 95.4 m 2.
The solution A diluted to 1 and the solution B diluted to 19.4 g of potassium bromide with distilled water to a volume of 97.4 ml were all added at a constant flow rate over 45 seconds. Thereafter, 10 ml of a 3.5% by mass aqueous solution of hydrogen peroxide was added, and further 10.8 ml of a 10% by mass aqueous solution of benzimidazole was added.
Further, distilled water was added to 51.86 g of silver nitrate to obtain 317.
A solution C diluted to 5 ml and a solution D prepared by diluting 45.8 g of potassium bromide to a volume of 400 ml with distilled water were all added at a constant flow rate over 20 minutes. The solution D was pAg
Was added by the controlled double jet method while maintaining at 8.1. The total amount of potassium hexachloride (III) acid salt was added 10 minutes after starting to add the solution C and the solution D so as to be 1 × 10 ⁻⁴ mol per mol of silver. Five seconds after the completion of the addition of the solution C, an aqueous solution of potassium hexairon cyanide (II) was added in an amount of 3 × 10 ^-4 mol per mol of silver. P using 0.5 mol / L sulfuric acid
H was adjusted to 3.8, stirring was stopped, and a settling / desalting / water washing step was performed. The pH was adjusted to 5.9 with 1 mol / L sodium hydroxide to prepare a silver halide dispersion having a pAg of 8.0.

While stirring the silver halide dispersion, 3
While maintaining the temperature at 8 ° C., 5 ml of a 0.34 mass% 1,2-benzisothiazolin-3-one methanol solution was added,
After 40 minutes, a methanol solution of the spectral sensitizing dye A described later was added to silver 1
1 × 10 ⁻³ mol per mol was added, and the temperature was raised to 47 ° C. one minute later. Twenty minutes after the temperature rise, 7.6 × 1 sodium benzenethiosulfonate was added to 1 mol of silver with a methanol solution.
0 ^-5 mols, further 5 minutes after below tellurium sensitizer B was aged 1.9 × 10 ^-4 mol was added for 91 minutes per mol of silver in the methanol solution. 1.3 m of a 0.8% by mass methanol solution of N, N'-dihydroxy-N "-diethylmelamine
After 4 minutes, 5-methyl-2-mercaptobenzimidazole was dissolved in a methanol solution at 3.7 × 10 ⁻³ mol per mol of silver and 1-phenyl-2-heptyl-5-mercapto-1, Silver halide emulsion 1 was prepared by adding 4.9 × 10 ⁻³ mol of 3,4-triazole to 1 mol of silver in a methanol solution.

The grains in the prepared silver halide emulsion 1 were pure silver bromide grains having an average equivalent sphere diameter of 0.046 μm and a coefficient of variation of the equivalent sphere diameter of 20%. The particle size and the like were determined from the average of 1000 particles using an electron microscope. The {100} plane ratio of the particles was determined to be 80% using the Kubelka-Munk method.

(2) Preparation of Silver Halide Emulsion 2 In the preparation of silver halide emulsion 1, the liquid temperature during grain formation was changed from 34 ° C. to 49 ° C., and the addition time of solution C was changed to 30 minutes. A silver halide dispersion was prepared in the same manner except that potassium iron (II) was removed. Further, the addition amount of the spectral sensitizing dye A was 7.5 × 10 ⁻⁴ mol per mol of silver, and the addition amount of the tellurium sensitizer B was 1.1 × 10 mol per mol of silver.
× 10 ^-4 mol, and 1-phenyl-2-heptyl-5-
Silver halide emulsion 2 was prepared in the same manner as in the preparation of silver halide emulsion 1, except that mercapto-1,3,4-triazole was used in an amount of 3.3 × 10 ⁻³ mol per mol of silver. The emulsion grains of the silver halide emulsion 2 were pure silver bromide cubic grains having an average equivalent sphere diameter of 0.080 μm and a variation coefficient of the equivalent sphere diameter of 20%.

(3) Preparation of Silver Halide Emulsion 3 In the preparation of silver halide emulsion 1, the liquid temperature during grain formation was
In the same manner except that the temperature was changed from 34 ° C. to 27 ° C.
A silver halide dispersion was prepared. Further, the spectral sensitizing dye A was added to a solid component.
Powder (aqueous gelatin solution), added in 1 mole silver
6 × 10 per ^-3Mole and tellurium sensitizer B
5.2 × 10 per mole of silver^-FourHalogen except for mole
Silver halide emulsion 3 was prepared in the same manner as in the preparation of silver halide emulsion 1.
Was prepared. The emulsion grains of the silver halide emulsion 3 have a mean sphere.
Pure diameter of 0.038μm equivalent diameter and 20% variation coefficient of sphere equivalent diameter
The particles were cubic silver bromide particles.

(4) Preparation of silver halide mixed emulsion A 70% by weight of silver halide emulsion 1, 15% by weight of silver halide emulsion 2 and 15% by weight of silver halide emulsion 3 were mixed. A 1% by weight aqueous solution of benzothiazolium iodide was added in an amount of 7 × 10 ⁻³ mol per mol of silver.

<< Preparation of Dispersion of Fatty Acid Silver (Silver Behenate) >>
Behenic acid (manufactured by Henkel, product name Edenor C22)
-85R) 87.6 kg, 423 liters of distilled water, 5 mo
49.2 L of 1 / L NaOH aqueous solution, tert-
120 liters of butanol were mixed and reacted at 75 ° C. for 1 hour with stirring to obtain a sodium behenate solution. Separately, 206.2 liters (pH 4.0) of an aqueous solution of 40.4 kg of silver nitrate was prepared and kept at 10 ° C. 635
A reaction vessel containing 1 liter of distilled water and 30 liters of tert-butanol was kept at 30 ° C., and while stirring, the entire amount of the sodium behenate solution and the entire amount of the silver nitrate aqueous solution were kept at a constant flow rate for 62 minutes 10 seconds and 60 minutes, respectively. Added over minutes. At this time, only the aqueous silver nitrate solution was added for 7 minutes and 20 seconds after the addition of the aqueous silver nitrate solution was started, 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. The piping of the addition system of the sodium behenate solution was kept warm by steam tracing, and the steam opening was adjusted so that the liquid temperature at the outlet at the tip of the addition nozzle became 75 ° C. The piping of the silver nitrate aqueous solution addition system was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution.

After 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.

The morphology of the obtained silver behenate particles was evaluated by electron microscopic photographing. The average value was a = 0.14 μm.
m, b = 0.4 μm, c = 0.6 μm, an average aspect ratio of 5.2, an average equivalent sphere diameter of 0.52 μm, and a flake-like crystal having a sphere equivalent diameter variation coefficient of 15%. (A, b, c are the provisions of the text)

A wet cake having a dry solid content of 100 g was added to polyvinyl alcohol (trade name: PVA-21).
7) 7.4 g and water were added to make the total amount 385 g, and the mixture was pre-dispersed with a homomixer.

Next, the pre-dispersed stock solution is dispersed in a dispersing machine (trade name: Microfluidizer M-110S-EH, manufactured by Microfluidics International Corporation, using G10Z interaction chamber).
The pressure was adjusted to 1750 kg / cm ² , and the mixture was treated three times to obtain a silver behenate dispersion. In the cooling operation, a coiled heat exchanger was mounted before and after the interaction chamber, and the dispersion temperature was set to 18 ° C. by adjusting the temperature of the refrigerant.

<< Preparation of Reducing Agent Dispersion >> 1,1-bis (2
-Hydroxy-3,5-dimethylphenyl) -3,5
10 kg of 5-trimethylhexane and 20 parts of modified polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.)
16 kg of water was added to 10 kg of a mass% aqueous solution and mixed well to form a slurry. This slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours and 30 minutes, and then benzoisothiazolinone sodium salt was added. 0.2 g and water were added to adjust the concentration of the reducing agent to 25% by mass to obtain a reducing agent dispersion. The reducing agent particles contained in the thus obtained reducing agent dispersion had a median diameter of 0.42 μm and a maximum particle diameter of 2.0 μm.
It was below. The resulting reducing agent dispersion had a pore size of 10.0 μm.
Then, the mixture was filtered with a polypropylene filter of m to remove foreign substances such as dust, and stored.

<< Preparation of Development Accelerator Dispersion >> Development Accelerator
1 and 10 kg of a 20% by mass aqueous solution of denatured polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.)
16 kg of water was added to 0 kg and mixed well to form a slurry. This slurry is fed by a diaphragm pump and is filled with zirconia beads having an average diameter of 0.5 mm in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.).
After dispersing for 3 hours and 30 minutes, 0.2 g of benzoisothiazolinone sodium salt and water were added to adjust the concentration of the development accelerator to 20% by mass to obtain a development accelerator dispersion. The development accelerator particles contained in the development accelerator dispersion thus obtained had a median diameter of 0.51 μm and a maximum particle diameter of 2.0.
μm or less. The resulting development accelerator dispersion has a pore size of 1
Filtration was performed with a 0.0 μm polypropylene filter to remove foreign substances such as dust, and stored.

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

<< Preparation of Organic Polyhalogen Compound Dispersion-1 >> 5 kg of tribromomethylnaphthyl sulfone and modified polyvinyl alcohol (Poval MP20 manufactured by Kuraray Co., Ltd.)
2.5 kg of the 20% by mass aqueous solution of 3), 213 g of a 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate, and 10 kg of water were added and mixed well to form a slurry. This slurry is fed by a diaphragm pump and is filled with zirconia beads having an average diameter of 0.5 mm in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.).
After dispersing for 5 hours, 0.2 g of benzoisothiazolinone sodium salt and water were added to adjust the concentration of the organic polyhalogen compound to 20% by mass, thereby preparing an organic polyhalogen compound dispersion-1. . The organic polyhalogen compound particles contained in the obtained dispersion have a median diameter of 0.1.
36 μm, and the maximum particle size was 2.0 μm or less. The resulting organic polyhalogen compound dispersion-1 had a pore size of 3.0 μm.
Then, the mixture was filtered with a polypropylene filter of m to remove foreign substances such as dust, and stored.

<< Preparation of Organic Polyhalogen Compound Dispersion-2 >> In the same manner as for the organic polyhalogen compound dispersion-1, except that 5 kg of tribromomethylnaphthyl sulfone was used, tribromomethyl (4- (2,4,6 -Trimethylphenylsulfonyl) phenyl) sulfone 5 kg,
The organic polyhalogen compound was dispersed, diluted so as to have a concentration of 25% by mass, and filtered. The organic polyhalogen compound particles contained in the obtained dispersion had a median diameter of 0.38 μm and a maximum particle diameter of 2.0 μm or less. The resulting organic polyhalogen compound dispersion-2 had a pore size of 3.0.
Filtration was performed with a μm polypropylene filter to remove foreign substances such as dust, and stored.

<< Preparation of Organic Polyhalogen Compound Dispersion-3 >> Similar to Organic Polyhalogen Compound Dispersion-1, except that 5 kg of tribromomethylphenylsulfone was used instead of 5 kg of tribromomethylnaphthylsulfone.
5 kg of a 0% by mass aqueous solution of MP203 was dispersed, diluted with the organic polyhalogen compound to 26% by mass, and filtered. The organic polyhalogen compound particles contained in the obtained dispersion had a median diameter of 0.41 μm and a maximum particle diameter of 2.0 μm or less. The resulting organic polyhalogen compound dispersion-3 was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored. After storage, it was stored at 10 ° C. or lower until use.

<< Preparation of Phthalazine Compound Solution >> 8 Kg of modified polyvinyl alcohol MP203 manufactured by Kuraray Co., Ltd. was dissolved in 174.57 Kg of water, and then 3.15 kg of a 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate and 6-isopropylphthalate were dissolved. 14.28 kg of a 70% by mass aqueous solution of azine was added to prepare a 5% by mass solution of 6-isopropylphthalazine.

<< Preparation of Pigment Dispersion >> I. Pigme
To 64 g of nt Blue 60 and 6.4 g of Demol N manufactured by Kao Corporation, 250 g of water was added and mixed well to form a slurry. Zirconia beads 80 having an average diameter of 0.5 mm
0 g was prepared, put into a vessel together with the slurry, and dispersed for 25 hours with a disperser (1 / 4G sand grinder mill: manufactured by Imex Co., Ltd.) to obtain a pigment dispersion. The pigment particles contained in the obtained pigment dispersion had an average particle size of 0.2.
It was 1 μm.

<< Preparation of SBR Latex 40% by Mass >> The following SBR latex was diluted 10-fold with distilled water, and was subjected to ultrafiltration (UF) -purification module FS03-F.
Using C-FUY03A1 (Daisen Membrane System Co., Ltd.), the product was diluted and purified until the ionic conductivity became 1.5 mS / cm, and Sandet-B manufactured by Sanyo Chemical Co., Ltd.
L was added to be 0.22% by mass. Further NaO
Na ⁺ ion using H and NH ₄ OH: NH ₄ ⁺ ion =
1: 2.3 (molar ratio) and pH 8.4.
Was adjusted. The latex concentration at this time was 40% by mass. (SBR latex: -St (71) -Bu (2
6) Latex of -AA (3)-)

Average particle size 0.1 μm, concentration 45% by mass, 2
0.6% by mass equilibrium moisture content at 5 ° C. and 60% relative humidity;
Ion conductivity 4.2 mS / cm (Ion conductivity is measured using a conductivity meter CM-30S manufactured by Toa Denpa Kogyo Co., Ltd., and a latex stock solution (40% by mass) is measured at 25 ° C.), pH
8.2

<< Preparation of Coating Solution for Photosensitive Layer >> 1.1 g of the pigment dispersion obtained above and silver fatty acid (silver behenate) were obtained.
103 g of dispersion, polyvinyl alcohol PVA-205
5 g of a 20 mass% aqueous solution (manufactured by Kuraray Co., Ltd.), 25 g of a reducing agent dispersion, 5.5 g of a development accelerator dispersion, and organic polyhalogen compound dispersion-1, -2, and -3 in a ratio of 5: 1: 3 ( (Mass ratio) 11.4 g, mercapto compound dispersion 6.2
g, SBR latex (Tg: 24 ° C.) 40% by mass 10
6 g and a phthalazine compound solution (18 ml) were mixed, and just before coating, 10 g of a silver halide mixed emulsion A was added and mixed well to prepare a photosensitive layer coating solution. The obtained coating solution for the photosensitive layer was directly sent to a coating die at 70 ml / m ² .

The viscosity of the coating solution for the photosensitive layer was measured at 40 ° C. (No. 1 rotor, 60 rpm
m) was 85 [mPa · s]. The viscosity at 25 ° C. using an RFS Fluid Spectrometer manufactured by Rheometrics Far East Co., Ltd. was 1500, 220, 70, and 100 at a shear rate of 0.1, 1, 10, 100, and 1000 [1 / sec], respectively. 40, 20 [mP
a · s].

<< Preparation of Coating Solution for Intermediate Layer on Image Forming Layer >> 772 g of a 10% by mass aqueous solution of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.), pigment dispersion obtained above 5.
Aerosol OT was added to 226 g of 3 g of a 27.5 mass% liquid of methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20/5/2).
(American Cyanamid) 5% by weight aqueous solution
ml, 10.5 ml of a 20% by mass aqueous solution of diammonium phthalate, water was added so that the total amount becomes 880 g, and the mixture was adjusted with NaOH so that the pH became 7.5. Was prepared. The obtained intermediate layer coating solution was sent to a coating die so as to have a concentration of 10 ml / m ² . The viscosity of the coating solution for the intermediate layer is B type viscometer 40 ° C.
(No. 1 rotor, 60 rpm) at 21 [mPa ·
s].

<< Preparation of Coating Solution for First Layer of Image Forming Layer Surface Protective Layer >> Inert gelatin (64 g) was dissolved in water, and methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio: 64 / 9/20/5/2) 80 g of a 27.5% by weight latex liquid, 23 ml of a 10% by weight methanol solution of phthalic acid, 23% of a 10% by weight aqueous solution of 4-methylphthalic acid 23
28 ml of sulfuric acid having a concentration of 0.5 mol / liter,
Aerosol OT (American Cyanamid) 5
5% by mass of an aqueous solution containing 0.5% by mass of phenoxyethanol
g, 0.1 g of benzoisothiazolinone and a total amount of 75 g
Water was added so that the amount became 0 g to prepare a coating solution for the first layer of the image forming layer surface protective layer. Immediately before application, 26 ml of 4% by mass chromium alum was mixed with a static mixer, and 18.6 was mixed.
The solution was sent to the coating die at a rate of ml / m ² .
The viscosity of the coating liquid for the first protective layer was measured using a B-type viscometer at 40 ° C. (No.
It was 17 [mPa · s] with one rotor at 60 rpm.

<< Preparation of Coating Solution for Second Layer of Image Forming Layer Surface Protective Layer >> Inert gelatin (80 g) was dissolved in water, and methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio: 64 / 9/20/5/2) 102 g of a latex 27.5 mass% solution, 3.2 ml of a 5 mass% solution of N-perfluorooctylsulfonyl-N-propylalanine potassium salt, polyethylene glycol mono (N-perfluorooctyl sulfonyl) -N-propyl-2-aminoethyl) ether [average degree of polymerization of ethylene oxide = 1
5], 32 ml of a 2% by mass aqueous solution of aerosol OT
(American Cyanamid Co.) 5% by mass solution
ml, fine particles of polymethyl methacrylate (average particle size of 0.
7 μm) 4 g, polymethyl methacrylate fine particles (average particle size 4.5 μm) 21 g, 4-methylphthalic acid 1.6
g, phthalic acid 4.8 g, sulfuric acid 4 having a concentration of 0.5 mol / L
4 ml, benzoisothiazolinone 10 mg, total amount 650
g of water and an aqueous solution 445 containing 4% by mass of chromium alum and 0.67% by mass of phthalic acid.
of the image forming layer surface protective layer second layer coating solution was mixed with a static mixer immediately before coating, and 8.3 ml / m
^The solution was fed to the coating die so as to be ² . The viscosity of the coating solution was measured at 40 ° C. using a B-type viscometer (No. 1 rotor, 60 rpm).
m) was 9 [mPa · s].

<< Preparation of Photothermographic Material (Sample 101) >>
On the back side of the undercoating support, the antihalation layer coating solution was coated with a solid fine particle dye in an amount of 0.04 g / solid.
such that m ^2, its on the back surface protective layer coating solution was simultaneously coated as the coating amount of gelatin of 1.7 g / m ^2, and dried, to produce a back layer. An emulsion layer (a silver halide coating amount of 0.14 g / m
² ) The intermediate layer, the protective layer first layer, and the protective layer second layer were simultaneously coated in multiple layers by a slide bead coating method to prepare a photothermographic material sample 101. The coating and drying conditions are as follows.

The coating is performed at a speed of 160 m / min.
0.10 gap between the coating die tip and the support
0.30 mm, and the pressure in the decompression chamber is 19
It was set lower by 6 to 882 Pa. The support was neutralized with ion wind before coating. In the subsequent chilling zone, the coating liquid is cooled by air having a dry-bulb temperature of 10 to 20 ° C., and is transferred in a non-contact type. It was dried with a dry air having a wet bulb temperature of 15 to 23 ° C. After drying, the humidity was controlled at 25 ° C. at a relative humidity of 40 to 60%, and the film surface was heated to 70 to 90 ° C. After heating, the film surface was cooled to 25 ° C.

The matte degree of the produced photothermographic material was 550 seconds on the photosensitive layer side and 13 minutes on the back side in Beck smoothness.
It was 0 seconds. Further, the pH of the film surface on the photosensitive layer surface side was measured and found to be 6.0.

[0204]

Embedded image

[0205]

Embedded image

<< Evaluation of Photographic Performance >> The photothermographic material prepared above was applied to a Fuji Medical Dry Laser Imager FM-DPL (66 with a maximum output of 60 mW (IIIB)).
Exposure and thermal development (approximately 120
° C), and the obtained image was evaluated with a densitometer.

The reducing agent of the general formula (I), the compound of the general formula (A) and the compound of the general formula (II) used for the above-mentioned sample 101
Samples 102 to 12 were prepared in the same manner as in Sample 101, except that the type and amount of the hydrogen bonding compound were changed as shown in Table 1.
2 was produced. At this time, the compound represented by the general formula (A) is 5% methanol / water containing an equimolar amount of aqueous ammonia.
It was added as a water (1/1) solution after the addition of the phthalazine compound. The compound represented by the general formula (II) was added after the addition of the reducing agent dispersion in the following method.

<< Preparation of Dispersion of Compound of the Formula (II) >>
1.6 kg of water was added to 1 kg of the compound of the general formula (II) and 1 kg of a 20% by mass aqueous solution of a modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval MP203) and mixed well to form a slurry. This slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours and 30 minutes, and then benzoisothiazolinone sodium salt was added. 0.2 g and water were added to adjust the concentration of the compound of the general formula (II) to 25% by mass to obtain a solid fine particle dispersion. The additive particles contained in the dispersion thus obtained had a median diameter of 0.45 μm and a maximum particle diameter of 2.0 μm or less. The resulting dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

In Table 1, the amount of each compound used is shown as a relative mol% with respect to the amount of the reducing agent used in Sample 101. These samples were subjected to laser exposure and heat development as described above, and then the maximum density (Dma
x) was measured. Further, each sample was stored under the condition of 60 ° C.-50% for one day, and the fog density (ΔD
min) and change in color tone at a density of 1.0 (ΔEab)
Was measured. ΔEab is Hitachi color analyzer C2
L * a * b using F2 fluorescent lamp as light source
Determined from the chromaticity coordinates before and after storage in the color space, the sample 10
The relative values are shown with 1 as 100. These values are also shown in Table 1.

[0210]

[Table 1]

From Table 1, it can be seen that when only the compound of the general formula (A) is used for the reducing agent of the general formula (I), the effect of improving the storage stability of the dark image is slight, but the hydrogen bonding It can be seen that the combined use of a hydrophilic compound significantly improves the dark image storage stability. When only the hydrogen bonding compound is used, the effect of improving the fog density can be recognized to some extent by increasing the amount used, but the change in the color tone is not improved, but the adverse effect such as a decrease in the maximum color density is observed. is there.

Example 2 << Preparation of Reducing Agent Complex Dispersion >> 2,2-Methylenebis-
10 kg of a 1: 1 complex of (4-ethyl-6-tert-butylphenol) and triphenylphosphine oxide and 10 kg of a 20% by mass aqueous solution of modified polyvinyl alcohol (Polar MP203, manufactured by Kuraray Co., Ltd.) are mixed with 16 kg of water.
g was added and mixed well to form a slurry. This slurry is sent by a diaphragm pump and has an average diameter of 0.5 m.
horizontal sand mill filled with zirconia beads (UV
M-2: manufactured by IMEX Co., Ltd.) for 3 hours and 30 minutes, and then sodium benzoisothiazolinone salt 0.2
g and water were added to adjust the concentration of the reducing agent to 25% by mass to obtain a reducing agent complex dispersion. The reducing agent complex particles contained in the obtained reducing agent complex dispersion had a median diameter of 0.4.
6 μm, and the maximum particle size was 2.0 μm or less. The obtained reducing agent complex dispersion was filtered with a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Organic Polyhalogen Compound Dispersion-4 >> Similar to the preparation of organic polyhalogen compound dispersion-1 of Example 1, except that 5 kg of tribromomethylnaphthyl sulfone was used instead of N-butyl-3- Using 5 kg of tribromomethanesulfonylbenzamide, the mixture was dispersed, diluted so that the organic polyhalogen compound became 25% by mass, and filtered. The organic polyhalogen compound particles contained in the obtained dispersion had a median diameter of 0.41 μm and a maximum particle diameter of 2.0 μm or less. The resulting organic polyhalogen compound dispersion-4 was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Coating Solution for Photosensitive Layer >> In the preparation of the coating solution for the photosensitive layer in Example 1, 26 g of the reducing agent complex dispersion obtained above was used in place of the reducing agent. Using a total of 5.7 g of the organic polyhalogen compound dispersion-3 obtained in 1 and the organic polyhalogen compound dispersion-4 obtained above in a ratio of 1: 3 (mass ratio), the amount of the pigment dispersion was 0.22 g. A photosensitive layer coating solution was prepared in the same manner as described above. The obtained coating solution for the photosensitive layer was directly sent to a coating die at 70 ml / m ² .

<< Preparation of Photothermographic Material (Sample 201) >>
In the preparation of the photothermographic material (sample 101) of Example 1, the photosensitive layer coating solution obtained above was used,
A photothermographic material (sample 201) was prepared in the same manner except that the yellow dye compound 15 in the antihalation layer was removed.

Samples 202 to 21 were prepared in the same manner except that the type and amount of the reducing agent complex and development accelerator used for the photothermographic material / sample 201 were changed as shown in Table 2.
No. 6 was produced. The amount of each compound used was the sample 201
Of the reducing agent complex relative to the amount used. These samples were also evaluated in the same manner as in Example 1.
Table 2 also shows the results.

[0219]

[Table 2]

From Table 2, it can be seen that even when the reducing agent is used in the form of a complex with a hydrogen-bonding compound, the combined use of the compound of the formula (A) can significantly improve the dark image storage stability.

[0219]

The photothermographic material of the present invention has high heat development activity and excellent image storability.

Claims (5)

[Claims] 1. A photothermographic material having a photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one surface of a support, wherein the photosensitive silver halide is A compound represented by the general formula (A) and a hydrogen bonding compound on the surface to be contained, wherein the reducing agent is a compound represented by the following general formula (I) (represented by the general formula (I) The compound may form a complex with the hydrogen bonding compound). Embedded image [In the general formula (I), R ¹¹ and R ^{11 ′} each independently represent an alkyl group. R ¹² and R ^{12 ′} each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. X ¹¹ and X ^{11 ′} each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. R ¹¹ and X ¹¹ , R ^{11 '}
And X ^{11 ′} , R ¹² and X ¹¹ , and R ^{12 ′} and X ^{11 ′} may be bonded to each other to form a ring. L is -S- group or -C
Represents an HR ¹³ -group, wherein R ¹³ represents a hydrogen atom or an alkyl group. ] [In the general formula (A), P represents an oxygen atom, a sulfur atom or an NH group. Q ¹ represents an oxygen atom or a sulfur atom. Y ¹ is an OH group, OM group, SH group, SM group (wherein, M
Represents a counter ion) or an NH ₂ group. L ¹ represents a divalent linking group. Z represents an alkyl group, an aryl group or a heterocyclic group. ] 2. The photothermographic material according to claim 1, wherein the hydrogen bonding compound is a compound represented by the following general formula (II). Embedded image [In the general formula (II), R ²¹ , R ²² and R ²³ each independently represent an alkyl group, an aryl group, an alkoxy group,
Represents an aryloxy group, an amino group or a heterocyclic group,
These groups may be unsubstituted or have a substituent, and any two of R ²¹ , R ²² and R ²³ may be bonded to each other to form a ring. ] 3. The photothermographic material according to claim 1, further comprising a polyhalogen compound represented by the following general formula (III) on the same surface as the photosensitive silver halide. . Q- (Y) nC (Z ¹ ) (Z ² ) X (III) [In the general formula (III), Q represents an alkyl group, an aryl group or a heterocyclic group, and Y represents a divalent linking group. Represent
n represents 0 or 1, Z ¹ and Z ² each independently represent a halogen atom, and X represents a hydrogen atom or an electron-withdrawing group. ] 4. The photothermographic material according to claim 1, wherein the binder is an aqueous latex. 5. The binder has an average glass transition temperature of 20.
The photothermographic material according to any one of claims 1 to 4, wherein the temperature is from 60C to 60C.