JP2002090937A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material which ensures superior heat developability and image preservability and satisfactorily suppresses the sticking of dust and foreign matter causing void and spot defects after heat development in consideration of the problems of conventional techniques. SOLUTION: In the heat developable photosensitive material containing at least one photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one face of the base, at least one surfactant of the formula Rf-(Rc)n-Z [where Rf is a perfluoroalkyl; Rc is an alkylene; Z is a group having a polar group required to impart surface activity; and (n) is an integer of 0 or 1] and at least one compound of the formula Z-P-L-(C=Q)-Y [where P is O, S or NH; Q is O or S; Y is OH, OM, SH, SM (M is a counter ion) or NH2; L is an alkylene; and Z is an alkyl, aryl or a heterocyclic group] are contained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material which is less likely to cause spot defects after thermal development and has good image storability.

[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 environmental protection and space saving. Therefore, heat-development is possible as a medical diagnostic film and a photoengraving film that can be efficiently exposed by a laser imagesetter or a laser imager and can form a clear black image having high resolution and sharpness. There is a need for techniques relating to photosensitive materials. According to these photothermographic materials, a photothermographic processing system that does not require solution-based processing chemicals, is simpler and does not damage the environment can be supplied to customers. There are similar demands in the field of general image forming materials, but especially for medical diagnostic images, high definition images with excellent sharpness and granularity are required because fine description is required. From the viewpoint, there is a feature that a cool tone image is preferred. At present, various hard copy systems using pigments and dyes, such as ink jet printers and electrophotographs, are distributed as general image forming systems, but none of them are satisfactory as output systems for medical images.

On the other hand, thermal image forming systems using an organic silver salt are described in, for example, US Pat. Nos. 3,152,904 and 3,457,075 and D.C. "Thermally Processed Silver Systems" by Klosterboer (Imaging Processes and Materials, Neblett)
e, 8th edition, J.M. Sturge, V.S. Walworth, A.M. Edited by Shepp, ninth
Chapter, p. 279, 1989). In particular, the photothermographic material generally contains a catalytically active amount of a photocatalyst (for example, silver halide), a reducing agent, a reducible silver salt (for example, an organic silver salt), and if necessary, a color toning agent for controlling the color tone of silver. And an image forming layer dispersed in a binder matrix. The photothermographic material, after image exposure,
When heated to a high temperature (for example, 80 ° C. or higher), a black silver image is formed by an oxidation-reduction reaction between a reducible silver salt (functioning as an oxidizing agent) and a reducing agent. The oxidation-reduction reaction is
It is promoted by the catalytic action of the latent image of silver halide generated by exposure. Therefore, a black silver image is formed in the exposed area. U.S. Pat. No. 2,910,377, JP-B-43
It is disclosed in many documents including -4924.

On the other hand, in order to produce a photothermographic material at high speed and in a stable manner, it is important to adjust the physical properties of a coating solution using a surfactant. However, when a surfactant is used, there are problems in production such as repelling, surface roughening, etc., resulting in poor applicability and adhesion of foreign substances such as dust. It is known that a fluorine-based surfactant is effective for suppressing repelling and surface roughness (JP-A-10-197985). But,
Even with the use of such a fluorine-based surfactant, no satisfactory response has been achieved with respect to the problem caused by the attachment of foreign substances such as dust.

[0005]

In view of these problems of the prior art, the present invention not only has excellent heat developability and image storability, but also causes a white spot failure after heat development. It is an object of the present invention to provide a photothermographic material in which adhesion of dust and foreign matter is sufficiently suppressed.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventor has found that by using a surfactant having a specific structure in combination with a compound having a specific structure, thermal development showing an intended effect can be achieved. The inventors have found that a photosensitive material can be produced, and have reached the present invention. That is, the present invention relates to a photothermographic material containing at least one kind of photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one surface of a support, (F)
A photothermographic material comprising at least one surfactant represented by the formula (I) and at least one surfactant not represented by the following formula (A): General formula (F): Rf- (Rc) nZ [In the general formula (F), Rf represents a perfluoroalkyl group, Rc is an alkylene group, and Z is an anionic group necessary for imparting surface activity. , A group having a cationic group or a nonionic polar group, and n represents an integer of 0 or 1. n is preferably 1. General formula (A): ZPL- (C = Q) -Y [In general formula (A), P represents an oxygen atom, a sulfur atom, or an NH group. Q represents an oxygen atom or a sulfur atom.
Y represents an OH group, an OM group, an SH group, an SM group (where M represents a counter ion) or an NH ₂ group. L represents an alkylene group. Z represents an alkyl group, an aryl group or a heterocyclic group. ]

In the photothermographic material of the present invention, a compound represented by the following formula (I) is preferably used as a reducing agent. General formula (I):

Embedded image [In the general formula (I), R ¹ and R ¹ ′ each independently represent an alkyl group having 1 to 20 carbon atoms. R ² and R ² ′ each independently represent a hydrogen atom or a substituent that can be substituted on a benzene ring. L is -S- group or -CHR ³ - represents a group.
R ³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. X and X ′ each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. ]

It is preferable to use a compound represented by the following general formula (II) in the photothermographic material of the present invention. General formula (II):

Embedded image [In the general formula (II), R ¹⁰ , R ¹¹ and R ¹² each independently represent an alkyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group. ]

Further, it is preferable to use a compound represented by the following general formula (III) in the photothermographic material of the present invention. General formula (III): Q- (Y) nC (Z ¹ ) (Z ² ) X [In the general formula (III), Q represents an alkyl group, an aryl group or a heterocyclic group, and Y is a divalent Represents a linking group,
n represents 0 or 1, Z ¹ and Z ² represent a halogen atom, and X represents a hydrogen atom or an electron-withdrawing group. In this specification, “to” indicates a range including numerical values described before and after it as a minimum value and a maximum value, respectively.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The photothermographic material of the present invention will be described below in detail. The photothermographic material of the invention is characterized in that a surfactant represented by the general formula (F) and a compound represented by the general formula (A) are used in combination. By adopting such a combination,
It has become possible to provide a photothermographic material that not only has excellent heat developability and image storability, but also sufficiently suppresses the attachment of dust and foreign matter that causes white spot failure after heat development. .

Therefore, the compound represented by formula (F) will be described in detail. In general formula (F), Rf
Represents a perfluoroalkyl group having 3 to 20 carbon atoms, and specific examples, C ₃ F ₇ - group, C ₄ F ₉ - groups, C ₆ F ₁₃ -
Groups, C ₈ H ₁₇ -groups, C ₁₂ F ₂₅ -groups, C ₁₆ F ₃₃ -groups and the like. Rc represents an alkylene group. The alkylene group preferably has 1 to 20 carbon atoms, specifically, a methylene group, an ethylene group, a 1,2-propylene group,
Examples thereof include a 3-propylene group, a 1,2-butylene group, a 1,4-butylene group, a 1,6-hexylene group, and a 1,2-octylene group. n represents an integer of 0 or 1.

Z represents a group having a cationic group, an anionic group or a polar nonionic group necessary for imparting surface activity. As long as these groups are contained, the way of linking to Rc is not particularly limited. Examples of the anionic group necessary for imparting surface activity include a sulfonic acid group and its ammonium or metal salt, a phosphonic acid group and its ammonium or metal salt, a sulfate group and its ammonium or metal salt, and a phosphate ester. And its ammonium or metal salts. Examples of the cationic group required to have surface activity include:
Examples thereof include quaternary alkyl ammonium groups such as a trimerylammonium ethyl group and a trimethyl ammonium propyl group, and aromatic ammonium groups such as a dimethyl phenyl ammonium alkyl group and an N-methyl pyridinium group. Suitable counter ions are present in these groups, and examples of the counter ions include halogen ions, benzenesulfonic acid anions, and toluenesulfonic acid anions.
Toluenesulfonate anion is preferred. Examples of the nonionic group necessary for imparting surface activity include a polyoxyalkylene group and a polyhydric alcohol group.
Preferred are polyoxyalkylene groups such as polyethylene glycol and polypropylene glycol.

In the general formula (F), Rf is preferably a C 4-16 perfluoroalkyl group, more preferably a C 6-16 perfluoroalkyl group. Rc is preferably an alkylene group having 2 to 16 carbon atoms, and more preferably an alkylene group having 2 to 8 carbon atoms. Particularly preferred is an ethylene group. n is preferably 1. The type of bonding between the Rc group and the group required for imparting surface activity is not particularly limited, and the bonding can be performed with, for example, an alkylene group, an arylene group, or the like. These groups may have an oxy group, a thio group, a sulfonyl group, a sulfoxide group, a sulfonamide group, an amide group, an amino group, or the like in a main chain or a side chain. Specific examples of the surfactant represented by the general formula (F) are shown below, but the surfactant of the general formula (F) that can be used in the present invention is not limited thereto.

[0014]

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[0015]

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[0016]

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[0017]

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One kind of the surfactant represented by the general formula (F) may be selected and used alone, or two or more kinds may be used in combination. The surfactant represented by formula (F) can be added to any layer of the photothermographic material. For example, it can be added to a photosensitive layer, an intermediate layer, a surface protective layer, a back layer, a back surface protective layer,
Among them, it is particularly preferable to add the compound to the surface protective layer and the back surface protective layer. The amount of the fluorine-based surfactant represented by the general formula (F) is preferably in the range of 0.1 to 200 mg / m ² on the front side and the back side of the support, more preferably 0.5 to 50 mg. / M ² , more preferably 1
３０30 mg / m ² .

Next, the compound represented by formula (A) will be described. In the general formula (A), P is an oxygen atom,
Represents a sulfur atom or NH. Q represents an oxygen atom or a sulfur atom. Y is OH, OM, SH group, SM group (however,
M represents a counter ion) or NH ₂ . − (C =
Q) Preferred examples of the substituent represented by -Y include a carboxyl group, a carboxylate group, a thiocarboxyl group, a thiocarboxylate group, a dithiocarboxyl group, a dithiocarboxylate group, and a carbamoyl group. When Y is an OM group or a SM group, M represents a counter ion.
Examples of counter ions include inorganic or organic ammonium ions (eg, ammonium ion, triethylammonium ion, pyridinium ion), alkali metal ions (eg, sodium ion, potassium ion), and alkaline earth metal ions (eg, calcium ion) , Magnesium ions) and other metal ions (eg, aluminum ions, barium ions, zinc ions). Ionic polymer or other organic compound having opposite charge, or metal complex ion (eg, hydroxopentaaquaaluminum (III) ion, tris (2,2′-bipyridine) iron (II) ion)
Can also be counter ions. Further, it may form an inner salt with another substituent in the molecule. Preferred are sodium ion, potassium ion, ammonium ion, triethylammonium ion and pyridinium ion, and more preferred are sodium ion, potassium ion and ammonium ion.

L represents an alkylene group. The length of the alkylene group represented by L is preferably from 1 to 4 atoms, more preferably from 1 to 2 atoms. The alkylene group represented by L may further have a substituent. -CH ₂ Preferred examples _{-, - CH 2 CH 2 -} , - CH (C
_{H 3) -, - CH (} CH 2 CH 3) CH 2 - and the like. More preferred, -CH ₂ - is. Z
Represents an alkyl group, an aryl group or a heterocyclic group. Z
The alkyl group represented by is a linear, branched, or cyclic alkyl group or a combination thereof, and preferably has 1 to 40 carbon atoms, more preferably 1 to 30 carbon atoms, and still more preferably 1 to 25 carbon atoms. For example, methyl group, ethyl group, allyl group, propyl group, isopropyl group, butyl group, sec-
Butyl group, isobutyl group, tert-butyl group, pentyl group, sec-pentyl group, isopentyl group, tert
-Pentyl, hexyl, cyclohexyl, octyl, tert-octyl, decyl, undecyl, dodecyl, tridecyl, pentadecyl, nonadecyl, icosyl, docosyl, 2-hexyldecyl, 2- Ethylhexyl group, 6-methyl-1- (3-
Methylhexyl) nonyl group, benzyl group and the like.

The alkyl group represented by Z may have a substituent, and the substituent may be any known group. For example, halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom), alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group (including N-substituted nitrogen-containing heterocyclic group, for example, morpholino group ), Alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, imino group, imino group substituted with N atom, thiocarbonyl group, carbazoyl group, cyano group, thiocarbamoyl group, alkoxy group, aryloxy group, heterocyclic oxy group An acyloxy group, an (alkoxy or aryloxy) carbonyloxy group, a sulfonyloxy group, an acylamide group, a sulfonamide group, a ureido group, a thioureido group, an imide group, an (alkoxy or aryloxy) carbonylamino group, a sulfamoylamino group, Semi-carba Group, thiosemicarbazide group, (alkyl or aryl) sulfonylureido group, nitro group, (alkyl or aryl) sulfonyl group, sulfamoyl group, group containing a phosphoric acid amide or a phosphoric ester structure, silyl group, carboxyl group or a salt thereof , A sulfo group or a salt thereof, a phosphate group, a hydroxy group, and a quaternary ammonium group. These substituents may be further substituted with these substituents. Examples of the alkyl group having a substituent represented by Z 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 ( Ethylthioethyl group) and the like.

The aryl group represented by Z is a monocyclic or condensed-ring aryl group, preferably has 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, still more preferably 6 to 10 carbon atoms, and is a phenyl group or naphthyl. 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. For example, the same groups as the above-mentioned substituents of the alkyl group can be mentioned. 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 P, Q or Y with a silver ion. 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 wherein the heterocyclic ring contains at least one heteroatom selected from the group consisting of nitrogen, oxygen and sulfur atoms. Those that are rings are preferred. Examples of the hetero ring, preferably pyridine ring, quinoline ring, isoquinoline ring, pyrimidine ring, pyrazine ring, pyridazine ring, phthalazine ring, triazine ring, furan ring, thiophene ring,
Pyrrole ring, oxazole ring, benzoxazole ring,
Thiazole ring, benzothiazole ring, imidazole ring,
Examples include a benzimidazole ring, a thiadiazole ring, and a triazole ring, and more preferably a pyridine ring, a quinoline ring, a pyrimidine ring, a thiadiazole ring, and a benzothiazole ring, and particularly preferably a pyridine ring, a quinoline ring, and a pyrimidine ring. 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 an optionally substituted phenyl group, naphthyl group, quinolyl group, pyridyl group, pyrimidyl group or polyethyleneoxy group, more preferably phenyl group or substituted phenyl group. Preferred are a 2-alkylphenyl 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) may be 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, dibutyl phthalate,
An oil such as tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone can be used to dissolve and mechanically prepare 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 formula (A) may be added to any layer on the image forming layer side of the support, but is preferably added to the image forming layer or a layer adjacent thereto. . The amount of the compound represented by the general formula (A) is preferably in the range of 0.01 to 10 mmol / m ² ,
More preferably 0.1 to 5 mmol / m ^2, even more preferably from 0.2~2mmol / m ^2. Preferred examples of the compound represented by Formula (A) are shown below, but the compounds of Formula (A) that can be used in the present invention are not limited thereto.

[0027]

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[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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Next, the non-photosensitive organic silver salt used in the photothermographic material of the present invention will be described. The non-photosensitive organic silver salt that can be used in the present invention is relatively stable to light, but can be reduced to 80% in the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent. It is a silver salt that forms a silver image when heated to a temperature of ℃ or more. The organic silver salt can be any organic substance including a source capable of reducing silver ions. For such non-photosensitive organic silver salts,
Paragraph No. [0048] of JP-A-10-62899
[0049], European Patent Publication EP 0803764A.
No. 1, page 18, line 24 to page 19, line 37, EP 0 962 812 A1. Silver salts of organic acids, especially silver salts of long-chain aliphatic carboxylic acids (with 10 to 30 carbon atoms, preferably 15 to 28 carbon atoms) are preferred. Preferred examples of the organic silver salt include silver behenate,
Silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, mixtures thereof, and the like. In the present invention,
Among these organic silver salts, a silver behenate content of 75 mol%
It is preferable to use the above-mentioned organic acid silver.

The shape of the organic silver salt that can be used in the present invention is not particularly limited, and may be needle-like, rod-like, plate-like, or scaly. 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 the 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.
May be the same as b. ) Then, the shorter numerical value a,
Calculate with b and obtain x as follows. x = b / a As described above, x is obtained for about 200 particles, and as an average value x (average), those satisfying a relationship of x (average) ≧ 1.5 are regarded as scaly. Preferably 30 ≧
x (average) ≧ 1.5, more preferably 20 ≧ x (average)
≧ 2.0. By the way, the needle shape is 1 ≦ x (average) <1.
5 In the scaly particle, a can be regarded as the thickness of a tabular particle having a main plane with b and c as sides. The average of a is preferably 0.01 μm to 0.23 μm, more preferably 0.1 μm to 0.20 μm. The average of c / b is preferably 1 to 6, more preferably 1.05 to 4,
More preferably, 1.1 to 3, particularly preferably 1.1 to
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 still more preferably 50% of a value obtained by dividing the standard deviation of the length of each of the short axis and the long axis by each of the short axis and the long axis. It is as follows. The shape of the organic silver salt can be measured from a transmission electron microscope image of the organic silver salt dispersion. Another method for measuring monodispersity is to determine the standard deviation of the volume-weighted average diameter of the organic silver salt, and the percentage (coefficient of variation) divided by the volume-weighted average diameter is preferably 100% or less, It is preferably at most 80%, more preferably at most 50%. As a measurement method, for example, the organic silver salt dispersed in a liquid is irradiated with laser light, and the particle size (volume weighted average diameter) obtained by obtaining an autocorrelation function with respect to a time change of fluctuation of the scattered light is obtained. Can be. Known methods can be applied to the production of the organic acid silver used in the present invention and its dispersion method. For example, Japanese Patent Application Laid-Open No. H10-6
No. 2899, EP 0803763A
No. 1 and European Patent Publication EP962812A1 can be referred to.

In addition, when a photosensitive silver salt is present in the dispersion of the organic silver salt, the fog increases and the sensitivity is remarkably lowered. In the present invention, the amount of the photosensitive silver salt in the aqueous dispersion to be dispersed is 0.1 mol% or less based on 1 mol of the organic acid silver salt in the liquid, and the photosensitive silver salt is positively added. Not something. In the present invention, a photothermographic material can be produced by mixing an aqueous dispersion of an organic silver salt and an aqueous dispersion of a photosensitive silver salt. The mixing ratio of the organic silver salt and the photosensitive silver salt can be selected according to the purpose, but the ratio of the photosensitive silver salt to the organic silver salt is preferably in the range of 1 to 30 mol%, more preferably 3 to 30 mol%.
It is preferably in the range of ２０20 mol%, particularly 5-15 mol%.
Mixing two or more kinds of aqueous dispersions of organic silver salts and two or more kinds of aqueous dispersions of photosensitive silver salts is a preferable method for controlling photographic characteristics. In the present invention, the organic silver salt can be used in a desired amount.
m ² is preferred, and more preferably 1 to 3 g / m ² .

The photothermographic material of the present invention contains a reducing agent for an organic silver salt. The reducing agent for the organic silver salt is any substance (preferably an organic substance) that reduces silver ions to metallic silver.
It may be. Such a reducing agent is disclosed in JP-A-11-65.
No. 021, paragraph numbers [0043] to [0045]
And page 7, line 34 to page 18, line 12 of European Patent Publication EP 0803764A1. In the present invention, it is preferable to use a bisphenol reducing agent as the reducing agent, and it is particularly preferable to use the compound represented by the above general formula (I).

In the general formula (I), R ¹ and R ^{1 ′} each independently represent an alkyl group having 1 to 20 carbon atoms, at least one of which represents a secondary or tertiary alkyl group. R
² and R ^{2 ′} each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. X and X ^′ each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. R
¹ and X, R ^{1 ′} and X ^′ , R ² and X, and R ^{2 ′} and X ^′ may be bonded to each other to form a ring. L is a -S- group or-
Represents a CHR ³ — group, wherein R ³ is a hydrogen atom or a group having 1 to 2 carbon atoms.
Represents an alkyl group of 0.

In the general formula (I), R ¹ and R ^{1 ′} each independently represent an alkyl group having 1 to 20 carbon atoms. Specifically, it is a substituted or unsubstituted linear, branched or cyclic alkyl group. 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 ¹ and R ^{1 ′} are more preferably a secondary or tertiary alkyl group, specifically, an isopropyl group, an isobutyl group,
Examples thereof include a t-butyl group, a t-amyl group, a t-octyl group, a cyclohexyl group, a cyclopentyl group, a 1-methylcyclohexyl group, and a 1-methylcyclopropyl group. More preferred are tertiary alkyl groups, and among them, a t-butyl group, a t-amyl group, and a 1-methylcyclohexyl group are particularly preferred, and a t-butyl group is most preferred.

R ² and R ^{2 ′} each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. X and X
^' Independently represents a hydrogen atom or a group that can be substituted on a benzene ring. As a group that can be substituted on the benzene ring,
Preferably, an alkyl group, an aryl group, a halogen atom, an alkoxy group, an acylamino group and the like are mentioned.

R ² and R ^{2 ′} are preferably an alkyl group, specifically, a methyl group, an ethyl group, a propyl group,
Butyl group, isopropyl group, t-butyl group, t-amyl group, cyclohexyl group, 1-methylcyclohexyl group,
Benzyl, methoxymethyl, methoxyethyl and the like. More preferred are a methyl group, an ethyl group, a propyl group, an isopropyl group and a t-butyl group. X and X ^′ are preferably a hydrogen atom, a halogen atom or an alkyl group, and particularly preferably a hydrogen atom. R ¹
And X, R ^{1 ′} and X ^′ , R ² and X, and R ^{2 ′} and X ^′ may combine with 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 ³ — group, and R ³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. R ³ is specifically a substituted or unsubstituted, linear, branched or cyclic alkyl group. Specific examples of the unsubstituted alkyl group represented by R ¹³ include a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, an undecyl group, an isopropyl group, a 1-ethylpentyl group,
4,4-trimethylpentyl group and the like. R ³
The substituent of the substituted alkyl group represented by R ¹ and R ^{1 ′}
And the same as the substituent of the alkyl group represented by L is preferably a -CHR ³ - is a group.

R ³ is a hydrogen atom or an alkyl group,
The alkyl group may be unsubstituted or substituted with another group. Specific examples of the unsubstituted alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group,
Examples include an undecyl group, an isopropyl group, a 1-ethylpentyl group, and a 2,4,4-trimethylpentyl group. Examples of the substituent of the alkyl group include a halogen atom, an alkoxy group, an alkylthio group, an aryloxy group, an arylthio group, an acylamino group, a sulfonamide group, a sulfonyl group, a phosphoryl group, an oxycarbonyl group, a carbamoyl group, and a sulfamoyl group. . Preferred as R ³ are a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group and a 2,4,4-trimethylpentyl group. Particularly preferred as R ³ is a hydrogen atom,
It is a methyl group, an ethyl group or a propyl group.

When R ³ is a hydrogen atom, R ² and R ² ′ are preferably an alkyl group having 2 to 5 carbon atoms,
An ethyl group and a propyl group are more preferred, and an ethyl group is most preferred. When R ³ is a primary or secondary alkyl group having 1 to 8 carbon atoms, R ² and R ² ′ are preferably methyl groups. As the primary or secondary alkyl group having 1 to 8 carbon atoms for R ^3, a methyl group, an ethyl group, a propyl group, and an isopropyl group are more preferred, and a methyl group, an ethyl group, and a propyl group are still more preferred. Specific examples of the compound represented by formula (I) are shown below, but the compounds that can be used in the present invention are not limited to these.

[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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In the present invention, the amount of the reducing agent added is 0.01
To 5.0 g / m ² , preferably 0.1 to 3.0 g / m ² .
The content is more preferably 0 g / m ² , and is preferably contained in an amount of 5 to 50% by mole, more preferably 10 to 40% by mole, per mole of silver on the surface having the image forming layer. The reducing agent is preferably contained in the image forming layer. The reducing agent is contained in the coating liquid by any method such as a solution form, an emulsified dispersion form, a solid fine particle dispersion form,
It may be contained in a photosensitive material. Well-known emulsification dispersion methods include dissolving using an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically producing an emulsified dispersion. Method.

As a method for dispersing solid fine particles, a powder of a reducing agent is dispersed in a suitable solvent such as water by a ball mill, a colloid mill, a vibration ball mill, a sand mill, a jet mill, a roller mill, or ultrasonic waves to obtain a solid dispersion. Is produced. In this case, 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. Good. The aqueous dispersion can contain a preservative (eg, benzoisothiazolinone sodium salt).

In the photothermographic material of the present invention, a phenol derivative represented by the formula (A) described in Japanese Patent Application No. 11-73951 is preferably used as a development accelerator.

When the reducing agent used in the present invention has an aromatic hydroxyl group (—OH), particularly in the case of the above-mentioned bisphenols, a non-functional compound having a group capable of forming a hydrogen bond with these groups is used. It is preferable to use a reducing compound in combination. Examples of the group that forms a hydrogen bond with a hydroxyl group or an amino group include a phosphoryl group, a sulfoxide group, a sulfonyl group, a carbonyl group, an amide group, an ester group, a urethane group, a ureido group, a tertiary amino group, and a nitrogen-containing aromatic group. No. Among them, preferred are a phosphoryl group, a sulfoxide group, and an amide group (provided that they have no> NH group,
> NR (R is a substituent other than H). ), Urethane group (provided that it does not have a> NH group,
> NR (R is a substituent other than H). ), Ureido group (provided that it has no> NH group,
> NR (R is a substituent other than H). ).

In the present invention, a particularly preferred hydrogen bonding compound is a compound represented by the above formula (II). In the general formula (II), R ¹⁰ , R ¹¹ and R ¹² each independently represent an alkyl group, an aryl group, an aralkyl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group, and these groups are unsubstituted Or may have a substituent. When R ¹⁰ , R ¹¹ and R ¹² have a substituent, examples of the substituent include a halogen atom, an alkyl group, an aryl group, an alkoxy group, an amino group, an acyl group, an acylamino group, an alkylthio group, an arylthio group, a sulfonamide group, An acyloxy group, an oxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, a phosphoryl group and the like can be mentioned, and a preferable substituent is an alkyl group or an aryl group such as a methyl group, an ethyl group, an isopropyl group, a t-butyl group, t-octyl group, phenyl group, 4-
Examples thereof include an alkoxyphenyl group and a 4-acyloxyphenyl group.

The alkyl group of R ^{10 to} R ¹² is preferably a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, such as a straight-chain, branched-chain, cyclic or combination thereof. Ethyl group, butyl group, octyl group, dodecyl group, isopropyl group, t-butyl group, t-amyl group,
Examples include a t-octyl group, a cyclohexyl group, a 1-methylcyclohexyl group, a benzyl group, a phenethyl group, and a 2-phenoxypropyl group. As an example of the aralkyl group, an aralkyl group having 7 to 27 carbon atoms is preferable, and examples thereof include a benzyl group, a phenethyl group, and a 2-phenoxypropyl group.

The aryl group is preferably a monocyclic or polycyclic substituted or unsubstituted aryl group having 6 to 20 carbon atoms.
Phenyl, cresyl, xylyl, naphthyl, 4
-T-butylphenyl group, 4-t-octylphenyl group, 4-anisidyl group, 3,5-dichlorophenyl group and the like. As the alkoxy group, one having 1 to 2 carbon atoms
A substituted or unsubstituted alkoxy group of 0 linear, branched, cyclic, or a combination thereof is preferably a methoxy group,
Examples include ethoxy, butoxy, octyloxy, 2-ethylhexyloxy, 3,5,5-trimethylhexyloxy, dodecyloxy, cyclohexyloxy, 4-methylcyclohexyloxy, and benzyloxy groups. As the aryloxy group, an aryloxy group having 6 to 20 carbon atoms is preferable, and a phenoxy group, a cresyloxy group, an isopropylphenoxy group,
-T-butylphenoxy group, naphthoxy group, biphenyloxy group and the like.

The amino group is preferably an amino group having 0 to 20 carbon atoms, such as a dimethylamino group, a diethylamino group,
Dibutylamino group, dioctylamino group, N-methyl-
Examples include an N-hexylamino group, a dicyclohexylamino group, a diphenylamino group, an N-methyl-N-phenylamino group, and the like. As the heterocyclic group, N, O or S
A 3- or 10-membered saturated or unsaturated heterocyclic group containing at least one atom, which may be a single ring or may form a condensed ring with another ring. Specific examples of the heterocyclic ring in the heterocyclic group, for example, pyrrolidine, piperidine, piperazine, morpholine, thiophene, furan, pyrrole, imidazole, pyrazole,
Pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline,
Cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzothiazole, benzselenazole, indolenine, tetrazaindene and the like.

R ¹⁰ and R ¹¹ , R ¹¹ and R ¹² or R ¹⁰ and R ¹¹
And R ¹² together can represent an optionally substituted monocyclic or polycyclic hydrocarbon group. R ¹⁰ ~R ¹²
Preferred are an alkyl group, an aryl group, an alkoxy group, and an aryloxy group. In terms of the effect of the present invention, R ¹⁰ to
Preferably, at least one of R ¹² is an alkyl group or an aryl group, and more preferably, two or more is an alkyl group or an aryl group. Further, it is preferable that R ^{10 to} R ¹² are the same group in that they can be obtained at a low cost. Specific examples of the compound of the general formula (II) are shown below, but the compounds that can be used in the present invention are not limited to these.

[0061]

Embedded image

[0062]

Embedded image

[0063]

Embedded image

[0064]

Embedded image

The compound of the general formula (II) can be contained in a coating solution in the form of a solution, an emulsified dispersion, or a solid-dispersed fine particle dispersion as in the case of the reducing agent, and used in a photothermographic material. The compound of the general formula (II) forms a hydrogen bonding complex with a compound having a phenolic hydroxyl group and an amino group in a solution state, and depending on the combination of the reducing agent and the compound of the general formula (II), the compound may form a complex. It can be isolated in crystalline form. It is particularly preferable to use the crystal powder isolated in this manner as a solid dispersion fine particle dispersion in order to obtain stable performance. Further, a method in which the reducing agent and the compound of the formula (II) 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 compound of the general formula (II) is preferably used in a range of 1 to 200 mol%, more preferably in a range of 10 to 150 mol%, and still more preferably in a range of 30 to 100 mol%, based on the reducing agent. It is.

Next, the photosensitive silver halide used in the photothermographic material of the present invention will be described. The halogen composition of the photosensitive silver halide used in the present invention is not particularly limited, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, and silver iodochlorobromide can be used. The distribution of the halogen composition in the grains may be uniform, the halogen composition may change stepwise, or may change continuously. Further, silver halide grains having a core / shell structure can be preferably used. The preferred structure is a two- to five-layer structure, and more preferably, a core / shell particle having a two- to four-layer structure can be used. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.

Methods for 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 gelatin or another polymer solution,
Thereafter, a method of mixing with an organic silver salt is used. Also, [0217] to [022] of JP-A-11-119374.
4], and the methods described in Japanese Patent Application Nos. 11-98708 and 11-84182 are also preferable. The grain size of the photosensitive silver halide is preferably small for the purpose of suppressing white turbidity after image formation, specifically, 0.20 μm or less, more preferably 0.02 μm or less.
1 μm to 0.15 μm, more preferably 0.02 μm
0.12 μm is preferred. The grain size as used herein refers to a diameter when converted into a circular image having the same area as the projected area of a silver halide grain (in the case of a tabular grain, the projected area of a main plane).

The shape of the silver halide grains is cubic,
Octahedral, tabular particles, spherical particles, rod-like particles, potato-like particles and the like can be mentioned. In the present invention, cubic particles are particularly preferable. Grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grains is not particularly limited. However, the spectral sensitization efficiency when the spectral sensitizing dye is adsorbed is high. preferable. The ratio is preferably at least 50%, more preferably at least 65%, even more preferably at least 80%. The ratio of the Miller index {100} plane was determined by T. Tani; J. Imaging Sci., 29, 165 (1985) using the dependence of the adsorption of the sensitizing dye on the {111} plane and the {100} plane. It can be determined by the method described.

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. However, the hexacyano metal complex is easily miscible with water and is suitable for sodium ion and potassium ions which are suitable for the precipitation operation of a silver halide emulsion. Use of alkali metal ions such as ions, rubidium ions, cesium ions, and lithium ions, ammonium ions, and alkylammonium ions (for example, tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, and tetra (n-butyl) ammonium ion) Is preferred. The hexacyano metal complex is mixed with water and a suitable organic solvent miscible with water (eg, alcohols, ethers, glycols, ketones, esters, amides, etc.) and gelatin. Can be added. The amount of hexacyano metal complex added is
It 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.

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 aqueous silver nitrate solution used for grain formation is followed by sulfur sensitization, selenium sensitization and tellurium sensitization. Is added directly before the completion of the charging 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 adding 96% by mass of the total amount of silver nitrate added for forming particles, more preferably started after adding 98% by mass, After adding 99 mass%, it is especially preferable. When these hexacyano metal complexes are added after the addition of the aqueous silver nitrate solution immediately before the completion of grain formation, they can be adsorbed on the outermost surface of silver halide grains, and most of them form hardly soluble salts with silver ions on the grain surface. I do. Since the hexacyanoiron (II) silver salt is a salt which is harder to dissolve than AgI, re-dissolution by fine particles can be prevented, and silver halide fine particles having a small particle size can be produced. .

The photosensitive silver halide grains can contain a metal or a metal complex of Group 8 to Group 10 of the periodic table (showing Groups 1 to 18). Rhodium, ruthenium, and iridium are preferably the metals of Groups 8 to 10 of the periodic table or the central metal of the metal complex. One kind of these metal complexes may be used, or two or more kinds of complexes of the same metal and different metals may be used in combination. The preferred content is in the range of 1 × 10 ⁻⁹ mol to 1 × 10 ⁻³ mol per mol of silver. These heavy metals and metal complexes and their addition methods are described in paragraphs [0018] to [0] of JP-A-7-225449 and JP-A-11-65021.
024], paragraphs [0227] to [0240] of JP-A-11-119374.

Further, metal atoms (for example, [Fe (C)) which can be contained in the silver halide grains used in the present invention.
N) ₆ ] ^4- ), desalting and chemical sensitization of silver halide emulsions are described in paragraphs [0046] to [0050] of JP-A-11-84574 and JP-A-11-65021.
Nos. [0025] to [0031] of JP-A No. 11-119374, and paragraph numbers [0242] to [0242] of JP-A-11-119374
[0250].

Various gelatins can be used as the gelatin contained 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 coating solution containing an organic silver salt, it is preferable to use low molecular weight gelatin having a molecular weight of 500 to 60,000. 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.

The sensitizing dye applicable to the present invention is a sensitizing dye capable of spectrally sensitizing silver halide grains in a desired wavelength region when adsorbed on silver halide grains, and has a spectral sensitivity suitable for the spectral characteristics of an exposure light source. The sensitizing dye to be used can be advantageously selected. The sensitizing dye and the method of addition are described in
Paragraph Nos. [0103] to [01] of 1-65021
09], JP-A-10-186572, general formula (II)
And a dye represented by the general formula (I) in JP-A-11-119374 and paragraph [010]
6]; dyes described in Example 5 of U.S. Pat. Nos. 5,510,236 and 3,871,887;
JP-A-2-96131, JP-A-59-48753
Dyes disclosed in European Patent Publication EP 08
Japanese Patent Application No. 2000-86865, Japanese Patent Application No. 20-38865, p.
No. 00-102560 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 according to the sensitivity and the performance of fogging.
0 ^-6 to 1 mol are preferred, more preferably 10 ^-4 to 1
0 ^-1 mol.

According to 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, U.S. Pat. Nos. 3,877,943 and 4,873,184, and JP-A-5-873. 341432
Gazettes, JP-A-11-109947 and JP-A-10-111
No. 543, and the like.

The photosensitive silver halide grains in the present invention 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 the literature described in Paragraph No. [0030] of 1-65021 and compounds represented by formulas (II), (III) and (IV) in JP-A-5-313284 are more preferable.

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. About 10 ^-7 to 10 ^-3 mol is used. The conditions of the chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, the pAg is 6 to 11, and the temperature is 40 to 40.
It is about 95 ° C. A thiosulfonic acid compound may be added to the silver halide emulsion used in the present invention by the method described in European Patent Publication No. EP 293,917.

The light-sensitive silver halide emulsion in the light-sensitive material used in the present invention may be only one kind or two or more kinds (for example, those having different average grain sizes, different halogen compositions, different crystal habits). And those having different conditions of chemical sensitization). The gradation can be adjusted by using a plurality of photosensitive silver halides having different sensitivities.
Japanese Patent Application Laid-Open No. 57-119341 discloses a technique related to these.
JP-A-53-106125 and JP-A-47-392.
No. 9, No. 48-55730, No. 46-518
No. 7, No. 50-73627, No. 57-150
No. 841 and the like. It is preferable that the difference in sensitivity be 0.2 logE or more in each emulsion. The amount of photosensitive silver halide added is 1 m
Indicated by the amount of coated silver per ^{2, 0.03~0.6g} / m ²
Is preferably, more preferably from 0.05 to 0.4 g / m ^2, and most preferably from 0.1 to 0.4 g / m ^2, relative to the organic silver salt 1 mole, The photosensitive silver halide is preferably used in an amount of 0.01 mol to 0.5 mol, more preferably 0.02 mol to 0.3 mol.

Regarding the mixing method and mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the prepared silver halide particles and organic silver salt were mixed with a high-speed stirrer, ball mill, sand mill, colloid mill, 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 addition, mixing two or more kinds of aqueous dispersions of organic silver salts and two or more kinds of aqueous dispersions of photosensitive silver salts is a preferable method for adjusting photographic characteristics.

The preferred timing of adding silver halide to the coating solution for the image forming layer is from 180 minutes to immediately before coating, preferably from 60 minutes to 10 seconds before coating. There is no particular limitation as long as the effect of (1) fully appears. As a specific mixing method, a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is a desired time or N.Ha
There is a method using a static mixer or the like described in Chapter 8 of "Liquid Mixing Technology" (published by Nikkan Kogyo Shimbun, 1989) by Koji Takahashi, rnby, MFE Edwards, AWNienow, and the like.

The binder used in the organic silver salt-containing layer may be any polymer; suitable binders are transparent or translucent, generally colorless, and include natural resins and polymers and copolymers, synthetic resins and polymers and copolymers,
Other film-forming media, for example, gelatins,
Rubbers, poly (vinyl alcohol) s, hydroxyethyl celluloses, cellulose acetates, cellulose acetate butyrate, poly (vinyl pyrrolidone)
, Casein, starch, poly (acrylic acid) s, poly (methyl methacrylic acid) s, poly (vinyl chloride) s, poly (methacrylic acid) s, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers Copolymers, styrene-butadiene copolymers, poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethane) s, phenoxy resins, poly ( Vinylidene chloride), poly (epoxide), poly (carbonate)
, Poly (vinyl acetate) s, poly (olefins), cellulose esters, and poly (amides). The binder may be coated from water or an organic solvent or emulsion.

In the present invention, when the organic silver salt-containing layer is formed by coating using a coating solution in which 30% by mass or more of water is water and then drying, the binder of the organic silver salt-containing layer is further added. It improves when it is soluble or dispersible in an aqueous solvent (aqueous solvent), especially when it consists of a polymer latex having an equilibrium water content of 2% by mass or less at 25 ° C. and a relative humidity of 60%. The most preferred form has an ionic conductivity of 2.5
It is prepared so as to be not more than mS / cm. As such a preparation method, there is a method of purifying using a separation functional membrane after polymer synthesis.

The aqueous solvent in which the polymer 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, alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol;
Examples thereof include cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve, ethyl acetate, and dimethylformamide. Note that the term “aqueous solvent” is used herein even in a system in which the polymer is not thermodynamically dissolved but exists in a so-called dispersed state.

The “equilibrium moisture content at 25 ° C. and 60% relative humidity” refers to a polymer mass W ¹ which is in equilibrium with humidity in an atmosphere of 25 ° C. and 60% relative humidity and is absolutely dry at 25 ° C. It can be expressed as follows using the mass W ⁰ of the polymer. Equilibrium moisture 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 Materials Testing Method (edited by the Society of Polymer Science, Jinjinshokan).

The binder polymer at 25 ° C. and a relative humidity of 6
The equilibrium moisture content at 0% is preferably 2% by mass or less, more preferably 0.01% by mass to 1.5% by mass, further preferably 0.02% by mass to 1% 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 1 to 50000 nm, more preferably 5 to 50000 nm.
A range of about 1000 nm is preferable. 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, preferred embodiments of the polymer dispersible in an aqueous solvent include acrylic polymers, poly (esters), rubbers (for example, SBR resin), poly (urethane) s, poly (vinyl chloride) s, Hydrophobic polymers such as poly (vinyl acetate) s, poly (vinylidene chloride) s and poly (olefins) can be preferably used. 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 10,000 to 200,000. If the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and if it is too large, the film-forming 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)

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 latexes described above are also commercially available, and the following polymers can be used. Examples of acrylic polymers include Sebian A-463.
5,46583,4601 (manufactured 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 (all manufactured by Dainippon Ink and Chemicals, Inc.),
Nipol Lx416, 410, 438C, 2507
(Nippon Zeon Co., Ltd.) and other poly (vinyl chloride)
Examples of poly (olefin) s include G351 and G576 (all manufactured by Zeon Corporation), and examples of poly (vinylidene chloride) s include L502 and L513 (all manufactured by Asahi Chemical Industry Co., Ltd.). For example, Chemipearl S
120, SA100 (all manufactured by Mitsui Petrochemical Co., Ltd.) and the like. These polymer latexes may be used alone, or may be used in combination of two or more as needed.

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 preferable that The preferred molecular weight range is the same as described above. Styrene preferably used in the present invention
As the latex of butadiene copolymer, the above-mentioned P-
3-P-8, commercially available LACSTAR-3307
B, 7132C, Nipol Lx416 and the like. The latex used in the present invention preferably has a glass transition temperature (Tg) in the range of 10 ° C to 80 ° C, more preferably 20 ° C to 60 ° C. Tg
When two or more types of latexes different from each other are blended and used, the weight average Tg is preferably in the above range.

The organic silver salt-containing layer of the photothermographic material of the present invention may optionally contain a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose and carboxymethylcellulose. 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)
Those formed using a polymer latex are preferred. The amount of the binder in the organic silver salt-containing layer is such that the mass ratio of the total binder / organic silver salt is 1/10 to 10/1, and more preferably 1/10.
The range of 5 to 4/1 is preferred. Such an organic silver salt-containing layer is usually a photosensitive layer (image forming layer, emulsion layer) containing a photosensitive silver halide, which is a photosensitive silver salt. The binder / silver halide mass ratio is preferably in the range of 400 to 5, more preferably 200 to 10. The total binder amount of the image forming layer is 0.2 to
30 g / m ^2, more preferably in the range of 1 to 15 g / m ^2. A crosslinking agent for crosslinking and a surfactant for improving coating properties may be added to the image forming layer.

In the present invention, the solvent of the coating solution for the organic silver salt-containing layer of the light-sensitive material (the solvent and the dispersion medium are collectively referred to as a solvent for simplicity) is 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, more preferably 70% by mass or more. Preferred examples of the solvent composition include water and water / methyl alcohol = 90.
/ 10, water / methyl alcohol = 70/30, water / methyl alcohol / dimethylformamide = 80/15 /
5. Water / methyl alcohol / ethyl cellosolve = 85 /
10/5, water / methyl alcohol / isopropyl alcohol = 85/10/5, etc. (the numerical value is% by mass).

The antifoggant, stabilizer and stabilizer precursor which can be used in the present invention are described in JP-A-10-6289.
No. 9, paragraph No. [0070], page 20 line 57 to 21 of European Patent Publication EP 0803764A1.
Patents described on page 7, line 7 may be 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 Publication No. H11-11012, paragraphs [0111] to [0112]. Especially Japanese Patent Application No. 1
An organic halogen compound represented by the formula (P) described in 1-87297 and an organic polyhalogen compound represented by the general formula (II) described in JP-A-10-339934 are preferred.

Next, the organic polyhalogen compound preferably used in the present invention will be specifically described. Particularly preferred polyhalogen compounds are compounds represented by the following general formula (III). General formula (III) Q- (Y) nC (Z ¹ ) (Z ² ) X (In the general formula (III), Q represents an alkyl group, an aryl group or a heterocyclic group, and Y represents a divalent linkage. Represents a group,
n represents 0 or 1, Z ¹ and Z ² represent a halogen atom, and X represents a hydrogen atom or an electron-withdrawing group. )

In the general formula (III), Q represents an alkyl group, an aryl group or a heterocyclic group which may have a substituent. The alkyl group represented by Q in the general formula (III) is a linear, branched or cyclic alkyl group, preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 6 carbon atoms. . For example, methyl, ethyl, allyl, n-propyl, iso-propyl, sec-butyl, iso-butyl, tert-butyl, sec-pentyl, iso-pentyl, tert-pentyl, ter
t-octyl, 1-methylcyclohexyl and the like. Preferably it is a tertiary alkyl group.

The alkyl group represented by Q may have a substituent, and any substituent may be used as long as it does not adversely affect photographic performance. Atom, chloro atom, bromine atom or iodine atom), alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group (including N-substituted nitrogen-containing heterocyclic group, for example, morpholino group), alkoxycarbonyl group, Aryloxycarbonyl group, carbamoyl group, imino group, imino group substituted by an N atom, 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, Ruhon'amido group, a ureido group,
Thioureido group, imide group, (alkoxy or aryloxy) carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, (alkyl or aryl) sulfonyluureido group, nitro group, (alkyl or aryl) sulfonyl group, sulfamoyl Group, a group containing a phosphate amide or a phosphate ester structure, a silyl group, a carboxyl group or a salt thereof,
Examples thereof include a sulfo group or a salt thereof, a phosphate group, a hydroxy group, and a quaternary ammonium group. These substituents may be further substituted with these substituents.

The aryl group represented by Q in formula (III) is a monocyclic or condensed-ring aryl group, preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 10 carbon atoms. , A phenyl group or a naphthyl group is preferred. The aryl group represented by Q may have a substituent, and any substituent may be used as long as it does not adversely affect photographic performance. And the same groups as mentioned above. Particularly preferred is a case where Q is a phenyl group substituted by an electron-withdrawing group having a positive Hammett σp.
The electron withdrawing group σp value is preferably in the range of 0.2 to 2.0, and more preferably in the range of 0.4 to 1.0. Specifically, a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a sulfamoyl group,
Examples include an alkylsulfonyl group, an arylsulfonyl group, an alkylphosphoryl group, a sulfoxide group, an acyl group, a heterocyclic group, a halogen atom, a halogenated alkyl group, and a phosphoryl group. More preferred electron-withdrawing groups are a carbamoyl group, an alkoxycarbonyl group, an alkylsulfonyl group, and an alkylphosphoryl group, among which a carbamoyl group is most preferred.

The heterocyclic group represented by Q in formula (III) includes a 5- or 7-membered saturated or unsaturated heterocyclic ring containing at least one heteroatom selected from the group consisting of nitrogen, oxygen and sulfur atoms. Those which are monocyclic or fused rings are preferred. Examples of heterocycles are preferably pyridine, quinoline, isoquinoline, pyrimidine, pyrazine,
Pyridazine, phthalazine, triazine, furan, thiophene, pyrrole, oxazole, benzoxazole,
Examples thereof include thiazole, benzothiazole, imidazole, benzimidazole, thiadiazole, and triazole, more preferably pyridine, quinoline, pyrimidine, thiadiazole, and benzothiazole, and particularly preferably pyridine, quinoline, and pyrimidine. Q
The heterocyclic group represented by may have a substituent, and examples thereof include the same groups as the substituents of the alkyl group represented by Q. Particularly preferred as Q is a phenyl group substituted with an electron-withdrawing group having a positive Hammett σp. As a substituent of Q, it may have a ballast group used in a photographic material to reduce diffusivity, an adsorptive group to a silver salt, or a group imparting water solubility, or polymerize with each other to form a polymer. Or the substituents may be bonded to each other to form a bis-type, tris-type, or tetrakis-type.

In the general formula (III), Y represents a divalent linking group, preferably -SO _2- , -SO-, -CO
And particularly preferably —SO ₂ —. General formula (I
In II), n represents 0 or 1, but is preferably 1. Z ¹ and Z ² each independently represent a halogen atom (eg, fluorine, chlorine, bromine, iodine, etc.)
Most preferably, both Z ¹ and Z ² are bromine atoms. X represents a hydrogen atom or an electron-withdrawing group. X is preferably a hydrogen atom or a halogen atom, and most preferably a bromine atom.

Examples of the polyhalomethyl compound of the general formula (III) include, for example, US Pat. No. 3,874,946, US Pat. No. 4,756,999, and US Pat. No. 5,340,712. U.S. Pat.
No. 9,000, U.S. Pat. No. 5,464,737, JP-A-50-137126 and JP-A-50-837.
Nos. 9020, 50-119624, 59
-57234, JP-A-7-2781, 7
JP-A-5621, JP-A-9-160164, and JP-A-10-160164
JP-197988, JP-A-9-244177, JP-A-9-244178, JP-A-9-160167,
JP-A-9-319022, JP-A-9-258367, JP-A-9-265150, JP-A-9-319022, JP-A-10-197989, and JP-A-11-2423
No. 04, Japanese Patent Application No. 10-181449, No. 10
Compounds described in JP-A-292864, JP-A-11-90095, JP-A-11-89773, JP-A-11-205330 and the like can be mentioned. Specific examples of the polyhalomethyl compound represented by the general formula (III) are shown below, but the compounds that can be used in the present invention are not limited thereto.

[0105]

Embedded image

[0106]

Embedded image

[0107]

Embedded image

The polyhalomethyl compounds represented by the general formula (III) may be used alone or in combination of two or more.
The compound represented by formula (III) is preferably used in an amount of 10 ^-4 to 1 mol, more preferably 10 ^{-3 to} 0.8 mol, per 1 mol of the non-photosensitive silver salt in the image forming layer. And more preferably in the range of 5 × 10 ^{−3 to} 0.5 mol.

In the present invention, as a method for incorporating an antifoggant into a light-sensitive material, the method described in the above-mentioned method for containing a reducing agent can be mentioned, and it is preferable to add an organic polyhalogen compound as a solid fine particle dispersion. .

Other antifoggants include those described in JP-A-11
No.-65021, paragraph [0113] mercury (I
I) Salts, benzoic acids of paragraph [0114] of the same publication, salicylic acid derivatives represented by the formula (Z) of Japanese Patent Application No. 11-87297, and formulas of the Japanese Patent Application No. 11-23995 ( S), a formalin scavenger compound represented by claim 9, a triazine compound according to claim 9 in JP-A-11-352624, a compound represented by formula (III) in JP-A-6-11791, 4-hydroxy-6 -Methyl-1,3,3a, 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, and JP-B-55-125.
No. 81, and the compound represented by 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 image forming layer, more preferably to the organic silver salt-containing layer. The azolium salt may be added at any time during the preparation of the coating solution, and when the azolium salt is added to the organic silver salt-containing layer, any process from the preparation of the organic silver salt to the preparation of the coating solution may be performed. To just before application. The azolium salt may be added by any method such as powder, solution, and fine particle dispersion. Further, it may be added as a solution mixed with other additives such as a sensitizing dye, a reducing agent and a color tone agent. In the present invention, the addition amount of the azolium salt may be any amount, but is preferably 1 × 10 ⁻⁶ mol to 2 mol per mol of silver, and more preferably 1 × 10 ⁻³ mol.
More preferably, the mole is 0.5 to 0.5 mole.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained to control development by suppressing or accelerating development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. And paragraph numbers [0067] to [0069] of JP-A-10-62899, and JP-A-10-18657.
No. 2, the compounds represented by the general formula (I) and specific examples thereof are described in paragraphs [0033] to [0052], p.20, p.3 of EP-A-0803764A1.
It is described in Japanese Patent Application No. 11-273670, line 6-56. Among them, mercapto-substituted heteroaromatic compounds are preferred.

In the photothermographic material of the present invention, it is preferable to add a toning agent. For the toning agent, see JP-A-10-6289.
No. 9, Paragraph Nos. [0054] to [0055], EP Patent Publication No. 0803764A1, page 21, lines 23 to 48, and JP-A No. 2000-35631. Particularly, phthalazinones ( Phthalazinone, phthalazinone derivatives or metal salts; 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) For example, 4- (1-naphthyl) phthalazine, 6-isopropylphthalazine, 6-tert-butylflatazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine);
A combination of phthalazines and phthalic acids is preferred, and a combination of phthalazines and phthalic acids is particularly preferred.

The plasticizers and lubricants that can be used in the image forming layer are described in JP-A-11-65021, paragraph [0117]. , Paragraph number [0118] of the same publication, paragraph numbers [0136] to [0193] of JP-A-11-223898, and Japanese Patent Application No. 11-872.
Compounds of formulas (H), (1) to (3), formulas (A) and (B) described in Japanese Patent Application No. 97-97, and general formulas (III) to (V) described in Japanese Patent Application No. 11-91652. ) (Concrete compounds: Chemical formulas 21 to 24) and the contrast enhancement agent are described in paragraph [0102] of JP-A-11-65021 and paragraph [0194] of JP-A-11-223898.
To [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 1 mmol per mol of silver.
It is preferable to contain it in an amount of not more than mmol.

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 acids or salts thereof formed by hydration of diphosphorus pentoxide include:
Orthophosphoric acid (salt) and hexametaphosphoric acid (salt) can be mentioned. Specific salts include sodium orthophosphate, sodium dihydrogen orthophosphate, sodium hexametaphosphate, and ammonium hexametaphosphate. The amount of the acid or salt thereof formed by hydration of diphosphorus pentoxide (the amount of coating per m ^{2 of the} light-sensitive material) may be a desired amount according to the performance such as sensitivity and fog, but may be 0.1 to 50.
Preferably ^{0mg / m 2, 0.5~100mg / m} 2 is more preferable.

The photothermographic material according to the invention may be provided with a surface protective layer for the purpose of preventing adhesion of the image forming layer. The surface protective layer may be a single layer or a plurality of layers. Regarding the surface protective layer, see JP-A-11-65021.
Nos. [0119] to [0120]. Gelatin is preferred as the binder for the surface protective layer, but polyvinyl alcohol (PVA) is also preferred. As gelatin, inert gelatin (for example, Nitta Gelatin 750), phthalated gelatin (for example, Nitta Gelatin 801) and the like can be used. PV
Examples of A include PVA-105 which is a completely saponified product, PVA-205 and PVA-335 which are partially saponified products, and MP-203 which is a modified polyvinyl alcohol (all trade names manufactured by Kuraray Co., Ltd.). The coating amount (per 1 m ² of polyvinyl alcohol) of the protective layer (per layer) is preferably 0.3 to 4.0 g / m ² , and 0.3 to 2.0 g / m ² .
0 g / m ² is more preferred.

In particular, when the photothermographic material of the present invention is used 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 Hira Okuda and Hiroshi Inagaki, published by Kobunshi Kanko (1978))" and "Application of Synthetic Latex (Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, Keiji Kasahara) Molecular publishing society (1993)), "Synthesis of synthetic latex (Souichi Muroi, published by Kobunshi Kankokai (1970))" and the like, and specifically, methyl methacrylate (33.5% by mass) / Ethyl acrylate (50% by weight) / latex of methacrylic acid (16.5% by weight) copolymer, methyl methacrylate (47.5% by weight) / butadiene (4
Latex of 7.5% by mass) / itaconic acid (5% by mass) copolymer, latex of ethyl acrylate / methacrylic acid copolymer, methyl methacrylate (58.9%)
Mass%) / 2-ethylhexyl acrylate (25.4
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-
Latex of hydroxyethyl methacrylate (5.0% by mass) / acrylic acid (2.0% by mass) copolymer; Further, as a binder for the surface protective layer, a combination of a polymer latex described in Japanese Patent Application No. 11-6872, a technique described in paragraphs [0021] to [0025] of Japanese Patent Application No. 11-143058, etc. Paragraph Nos. [0027] to No. 11-6872 of the specification
Technology described in [0028], JP-A-2000-19678
The techniques described in paragraph numbers [0023] to [0041] of the above publication may be applied. The ratio of the polymer latex in the surface protective layer is preferably from 10% by mass to 90% by mass, particularly preferably from 20% by mass to 80% by mass of the whole binder. Coating amount of total binder (including water-soluble polymer and latex polymer) of surface protective layer (per layer) (support 1 m ²
(Per) is preferably 0.3 to 5.0 g / m ² ,
0.3-2.0 g / m < ² > is more preferable.

The preparation temperature of the coating solution for the image forming layer is from 30 ° C. to 6 ° C.
5 ° C. is preferred, a more preferred temperature is 35 ° C. to less than 60 ° C., and a more preferred temperature is 35 ° C. to 55 ° C. Also,
The temperature of the coating solution for the image forming layer immediately after the addition of the polymer latex is preferably maintained at 30 ° C to 65 ° C. Also,
It is preferable that the reducing agent and the organic silver salt are mixed before the addition of the polymer latex.

The image forming layer is composed of one or more layers on a support. Organic silver salt,
It consists of a photosensitive silver halide, a reducing agent and a binder, and optionally contains additional materials such as toning agents, coating auxiliaries and other auxiliaries. When it comprises 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 some. Other components 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 photothermographic material, each emulsion layer generally has a functional or non-functional layer between the light-sensitive layers, as described in U.S. Pat. No. 4,460,681. By using a functional barrier layer, they are kept distinct from each other.

Various dyes and pigments (eg, CI Pigment Blue 60, CI Pigment Blue) can be added to the photosensitive layer from the viewpoints of improving color tone, preventing interference fringes during laser exposure, and preventing irradiation.
Blue 64, CI Pigment Blue 15: 6) can be used. These are described in WO98 / 36322, JP-A-10-268465, and 11-33.
No. 8098, 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.

A photothermographic material generally has a non-photosensitive layer in addition to a 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
Paragraph numbers [0123] to [01] of JP-A-1-65021
24], JP-A Nos. 11-223898 and 9-23
0531, 10-36695, 10-
Nos. 104779, 11-231457, 11-352625, 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. It is particularly 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 JP-A-11-231457.
No., etc.

The amount of the decolorizable dye to be added 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 decolorizable dyes may be used in combination in a heat-decolorable recording material or a photothermographic material. Similarly, two or more base precursors may be used in combination. In thermal decoloring using such a decoloring dye and a base precursor,
When mixed with a base precursor as described in JP-A-11-352626, a substance (for example, diphenylsulfone, 4-chlorophenyl (phenyl) sulfone) that lowers the melting point by 3 ° C. (deg) or more can be used in combination with heat discoloration. It is preferable in terms of properties 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 side opposite to the image forming layer.

The photothermographic material of the present invention is a so-called single-sided photosensitive material having at least one image forming layer containing a silver halide emulsion on one side of a support and a back layer on the other side. Preferably, there is.

In the present invention, it is preferable to add a matting agent for improving transportability.
JP-A-11-65021, paragraph number [0126]-
[0127]. Matting material is photosensitive material 1
When represented by the coating amount per m ² , preferably 1 to 40
0 mg / m ^2, more preferably from 5 to 300 mg / m ^2. The matte degree of the image forming surface may be any value as long as the stardust failure does not occur.
00 seconds is preferable, and particularly 40 seconds to 1500 seconds is preferable. The Beck smoothness is based on Japanese Industrial Standard (JIS) P811.
9 "Smoothness test method for paper and paperboard using Beck tester" and TAPPI standard method T479.

In the present invention, the matte degree of the back layer is preferably such that the Bekk smoothness is 10 seconds to 1200 seconds,
Seconds to 800 seconds, more preferably 40 seconds to 5 seconds.
00 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 JP-A-11-65021, paragraph [0].
128] to [0130].

The photothermographic material of the present invention preferably has a film surface pH before heat development of 6.0 or less, more preferably 5.5 or less. 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 for measuring the film surface pH is described in paragraph [0123] of Japanese Patent Application No. 11-87297.

A hardener may be used for each layer such as the image forming layer, the protective layer, and the back layer. THJame is an example of a hardener
“THE THEORY OF THE PHOTOGRAPHIC PROCESS FOURTH
EDITION ”(published by Macmillan Publishing Co., Inc., 19
There are various methods described on pages 77 to 87, chromium alum, 2,4-dichloro-6-hydroxy-s
-Triazine sodium salt, N, N-ethylenebis (vinylsulfoneacetamide), N, N-propylenebis (vinylsulfoneacetamide), polyvalent metal ions described on page 78 of the same book, U.S. Pat. No. 4,281,060 Preferred are polyisocyanates such as described in JP-A-6-208193, epoxy compounds such as U.S. Pat. No. 4,791,042, and vinylsulfone-based compounds such as JP-A-62-89048. Can be

The hardener is added as a solution, and this solution is added to the protective layer coating solution from 180 minutes before coating.
Immediately before, preferably before 60 minutes to 10 seconds, there is no particular limitation on the mixing method and mixing conditions as long as the effects of the present invention are sufficiently exhibited. As a specific mixing method, there is a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is set to a desired time, Harnby, M .; F. Edwards,
A. W. Nienow, translated by Koji Takahashi “Liquid mixing technology”
(Nikkan Kogyo Shimbun, 1989), a method using a static mixer described in Chapter 8 and the like.

The surfactants applicable to the present invention are described in JP-A-11-65021, paragraph [0132],
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, and the same publication for the method of obtaining a color image. Publication paragraph number [01
36], paragraphs [0061] to [0064] of JP-A No. 11-84573 and Japanese Patent Application No.
No. 106881 Paragraph Nos. [0049] to [00]
62].

The transparent support is a polyester which has been 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. Particularly, polyethylene terephthalate is preferably used. In the case of a photothermographic material for medical use, the transparent support is made of a blue dye (for example,
It may be colored with dye-1) described in Examples of JP-A-240877, or may be uncolored. As the support, water-soluble polyester disclosed in JP-A-11-84574,
Styrene-butadiene copolymer disclosed in Japanese Patent Application No. 0-186565, paragraph [0] of Japanese Patent Application No. 11-106881.
[063] to [0080] It is preferable to apply an undercoating technique such as a vinylidene chloride copolymer. Japanese Patent Application Laid-Open No. 56-143430 discloses an antistatic layer or an undercoat.
JP-A-56-143431 and JP-A-58-626.
Nos. 46 and 56-120519,
No. 84573, paragraphs [0040] to [005]
1], U.S. Pat. No. 5,575,957, paragraphs [0078] to [0078] of JP-A-11-223898.
[0084] The technique described in [0084] can be applied.

The photothermographic material 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 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. Regarding them, WO 98/36322, European Patent Publication EP8
JP-A Nos. 03764A1, 10-186567 and 10-18568 can be referred to.

The photothermographic material of the present invention may be applied by any method. Specifically, extrusion coating, slide coating, curtain coating, dip coating, knife coating,
Flow coating or US Pat. No. 2,681,2
Various coating operations are used, including extrusion coating using a hopper of the type described in U.S. Pat.
“LIQUID FILM” by ephen F. Kistler and Peter M. Schweizer
COATING "(published by CHAPMAN & HALL, 1997
Year) pages 399 to 536, extrusion coating or slide coating is preferably used, and slide coating is particularly preferably used. An example of the shape of a slide coater used for slide coating is shown in FIG.
In one. If desired, two or more layers may be simultaneously coated by the method described on pages 399 to 536 of the same book, the method described in U.S. Pat. No. 2,761,791 and the British Patent No. 837,095. can do.

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 viscosity of the coating solution for the organic silver salt-containing layer in the present invention at a shear rate of 0.1 S ^-1 is preferably from 400 mPa · s to 100,000 mPa · s, more preferably from 500 mPa · s to 20,000.
mPa · s. Further, at a shear rate of 1000 S ⁻¹ , the pressure is preferably 1 mPa · s to 200 mPa · s, more preferably 5 mPa · s to 80 mPa · s.

Various systems expressing thixotropy are known, and are described in “Lecture / Rheology”, edited by Polymer Publishing Association, Muroi,
It is described in Morino co-authored "Polymer Latex" (published by the Society of Polymer Publishing). In order for a fluid to exhibit thixotropic properties, it is necessary to contain a large amount of solid fine particles.
In order to enhance the thixotropic property, it is effective to include a thickened linear polymer, to increase the aspect ratio of the contained solid fine particles in an anisotropic shape, to 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
JP-A-352627 is also cited.

The photothermographic material of the present invention may be developed by any method, but is usually developed by elevating the temperature of the photothermographic material exposed imagewise. The preferred development temperature is 80 to 250 ° C, more preferably 10 to 250 ° C.
0-140 ° C. The development time is preferably from 1 to 180 seconds, more preferably from 10 to 90 seconds, and from 10 to 40 seconds.
Seconds are particularly preferred.

As a method of thermal development, a plate heater method is preferable. The heat development method using a plate heater method is preferably a method described in JP-A-11-133572, and a visible image is obtained by bringing the heat-developable photosensitive 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 ° C.
It is preferable to lower the temperature. Such a method is also described in JP-A-54-30032, which makes it possible to exclude water and an organic solvent contained in a photothermographic material from the system, The change in the shape of the support of the photothermographic material due to the heating of the material can also be suppressed.

The photothermographic material of the present invention may be exposed by any method, but a laser beam is preferred as an exposure light source. As the laser beam according to the present invention, a gas laser (Ar ⁺ , He—Ne), a YAG laser, a dye laser, a semiconductor laser, 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 Medical Review No.
8, pages 39 to 55, and 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.

[0149]

The present invention will be described more specifically with reference to the following examples. The materials, amounts, proportions,
The processing content, processing procedure, and the like 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 specific examples described below.

Example 1 << Preparation of Undercoated PET Support >> (Preparation of PET Support) Using terephthalic acid and ethylene glycol, an intrinsic viscosity IV = 0.66 (phenol / tetrachloroform) Ethane = 25 in 6/4 (mass ratio)
(Measured in ° C.). After pelletizing this 1
It was dried at 30 ° 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 was longitudinally stretched 3.3 times using rolls having different peripheral speeds, and then transversely stretched 4.5 times using a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. After this, 240 ° C
After heat setting for 20 seconds, the film was relaxed 4% in the horizontal direction at the same temperature. After slitting the chuck part of the tenter,
Knurling both ends, winding at 4kg / cm ²
A roll having a thickness of 175 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 Undercoating Support) (1) Preparation of Undercoating Layer Coating Solution Formulation 1 (for the undercoating layer on the photosensitive layer side) Takamatsu Yushi Co., Ltd. Pesresin A-515GB (30% by mass solution) 234 g polyethylene glycol mono Nonyl phenyl ether (average ethylene oxide number = 8.5, 10% by mass solution) 21.5 g Soken Chemical Co., Ltd., MP-1000 (polymer fine particles, average particle diameter 0.4 μm) 0.91 g distilled water 744 ml

Formulation 2 (for the backside 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 Sodium laurylbenzenesulfonate (1% by mass aqueous solution) 10 ml Distilled water 854 ml

Formulation 3 (for back surface 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) 89.2 g Shin-Etsu 8.6 g, Metroze TC-5 (2 mass% aqueous solution) manufactured by Chemical Co., Ltd. MP-1000 0.01 g manufactured by Soken Chemical Co., Ltd. Sodium dodecylbenzenesulfonate (1 mass% aqueous solution) 10 ml NaOH (1 mass%) 6ml Proxel (ICI) 1ml Distilled water 805ml

(Preparation of undercoat support) The thickness of 175 μm
m biaxially stretched polyethylene terephthalate support
After applying the above corona discharge treatment to each,
Apply the above undercoating liquid formulation 1 to the image-forming layer side)
6.6ml / m wet coating amount with bar^Two(One side hit
And dried at 180 ° C for 5 minutes.
On the back side (back side) of the undercoating coating liquid formulation 2
5.7ml / m wet coating amount with wire bar ^TwoNana
And dried at 180 ° C for 5 minutes.
(Back side) Apply the undercoating coating liquid formulation 3 to a wire bar
And the wet coating amount is 7.7ml / m^TwoApply to become
And dried at 180 ° C. for 6 minutes to produce an undercoated support.
Was.

<< Preparation of Back Surface Coating Solution >> (Preparation of Solid Fine Particle Dispersion (a) of Base Precursor)
64 g of the base precursor compound 11, 28 g of diphenyl sulfone, and 10 g of non-fluorinated surfactant Demol N manufactured by Kao Corporation were mixed with 220 ml of distilled water, and the mixture was sand-milled (1/4 Gallon Sand Grinder Mill, IMEX Co., Ltd.). ) To obtain a solid fine particle dispersion (a) of a base precursor compound having an average particle diameter of 0.2 μm.

(Preparation of Dye Solid Fine Particle Dispersion) 9.6 g of cyanine dye compound 13 and 5.8 g of sodium p-dodecylbenzenesulfonate were mixed with 305 ml of distilled water, and the mixture was subjected to a sand mill (1/4 Gallon sand grinder mill). The dispersion was carried out using beads (manufactured by IMEX Co., Ltd.) to obtain a dye solid fine particle dispersion having an average particle diameter of 0.2 μm.

(Preparation of Anti-Halation Layer Coating Solution) 17 g of gelatin, 9.6 g of polyacrylamide, 70 g of solid fine particle dispersion (a) of the above base precursor, 56 g of the above solid fine particle dispersion of dye, and monodispersed polymethyl methacrylate fine particles (average Particle size: 8.0 μm) 1.5 g, benzoisothiazolinone 0.03 g, sodium polyethylenesulfonate 2.2 g, blue dye compound 14 in 0.2 g
g, yellow dye compound 15 (3.9 g) and water (844 ml) were mixed to prepare an antihalation layer coating solution.

(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 (vinylsulfone acetamide) 2.4 g, tert-octylphenoxyethoxyethaneethane sodium 1 g,
Benzoisothiazolinone 30 mg, N-perfluorooctylsulfonyl-N-propylalanine potassium salt 3
7 mg, polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [average degree of polymerization of ethylene oxide 15]
0.15 g, C ₈ F ₁₇ SO ₃ K 32 mg, C ₈ F ₁₇ SO ₂ N
(C ₃ H ₇ ) (CH ₂ CH ₂ O) ₄ (CH ₂ ) ₄ SO ₃ Na 64
mg, acrylic acid / ethyl acrylate copolymer (copolymerization mass ratio 5/95) 8.8 g, Aerosol OT (manufactured by American Cyanamid Co.) 0.6 g, 1.8 g of liquid paraffin emulsion as liquid paraffin, 950 ml of water
The mixture was mixed to give a back surface protective layer coating solution.

<< Preparation of Silver Halide Emulsion 1 >> Distilled Water 14
To 21 ml, 3.1 ml of a 1% by weight potassium bromide solution was added, and 3.5 ml of 0.5 mol / L sulfuric acid was further added.
While stirring the solution to which 31.7 g of phthalated gelatin was added in a stainless steel reaction bottle, the solution temperature was maintained at 34 ° C., solution A prepared by adding distilled water to 22.22 g of silver nitrate and diluting to 95.4 ml and potassium bromide. 15.9 g with distilled water to capacity 9
Solution B diluted to 7.4 ml was 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 1 ml of benzimidazole was further added.
10.8 ml of a 0% by mass aqueous solution was added. Further, a solution C obtained by adding distilled water to 31.86 g of silver nitrate to 317.5 ml and a solution D obtained by diluting 45.8 g of potassium bromide to a volume of 400 ml with distilled water were used.
The whole amount was added over 0 minutes, and solution D was added by a controlled double jet method while maintaining the pAg 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.
The pH was adjusted to 3.8 using 0.5 mol / L sulfuric acid, stirring was stopped, and a precipitation / desalting / water washing step was performed. PH using 1 mol / L sodium hydroxide
The mixture was adjusted to 5.9 to prepare a silver halide dispersion having a pAg of 8.0.

While stirring the above 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,
Forty minutes later, a methanol solution of the spectral sensitizing dye A was added at 1 × 10 ⁻³ mol per mol of silver, and the temperature was raised to 47 ° C. one minute later. Twenty minutes after the temperature rise, 7.6 × 10 ^-5 sodium benzenethiosulfonate was added to 1 mol of silver in a methanol solution.
After 5 minutes, 1.9 × 10 ^-4 mol of tellurium sensitizer B was added per mol of silver with a methanol solution, and the mixture was aged for 91 minutes. 1.3 ml of a 0.8% by weight methanol solution of N, N′-dihydroxy-N ″ -diethylmelamine was added, and after a further 4 minutes, 5-methyl-2-mercaptobenzimidazole was added to the methanol solution at a concentration of 3 per mole of silver. .
7 × 10 ^-3 mol and 1-phenyl-2-heptyl-5
Mercapto-1,3,4-triazole was added in a methanol solution at 4.9 × 10 ⁻³ mol per mol of silver to prepare a silver halide emulsion 1. The grains in the prepared silver halide emulsion were pure silver bromide grains having an average sphere equivalent diameter of 0.046 μm and a variation coefficient 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.

<< Preparation of Silver Halide Emulsion 2 >> In the preparation of Silver Halide Emulsion 1, the liquid temperature at the time of grain formation was set to 34 ° C.
Silver halide emulsion 2 was prepared in the same manner except that the temperature was changed to 9 ° C., the addition time of solution C was changed to 30 minutes, and potassium hexacyanoferrate (II) was removed. Silver halide emulsion 1
Precipitation / desalting / water washing / dispersion was carried out in the same manner as described above. 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 ⁴ mol per mol of silver.
^10-4 mol, 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole was changed to 3.3 × 10 ^-3 mol per mol of silver, in the same manner as in Emulsion 1. Spectral sensitization, chemical sensitization and 5-methyl-2-mercaptobenzimidazole, 1-phenyl-2-heptyl-5
Adding mercapto-1,3,4-triazole,
Thus, a silver halide emulsion 2 was obtained. 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%.

<< Preparation of Silver Halide Emulsion 3 >> In the preparation of silver halide emulsion 1, the liquid temperature during grain formation was set at 34 ° C. for 2 hours.
Except that the temperature was changed to 7.degree.
Was prepared. Further, precipitation / desalting / washing / dispersion / dispersion was carried out in the same manner as in silver halide emulsion 1. The spectral sensitizing dye A was added as a solid dispersion (aqueous gelatin solution) in an amount of 6 per mole of silver.
× 10 ^-3 mol, except for changing the amount of the tellurium sensitizer B was changed to 1 mole of silver per 5.2 × 10 ^-4 mol in the same manner as Emulsion 1, to obtain a silver halide emulsion 3. The emulsion grains of the silver halide emulsion 3 were pure silver bromide cubic grains having an average sphere equivalent diameter of 0.038 μm and a coefficient of variation of the equivalent sphere diameter of 20%.

<< Preparation of Silver Halide Mixed Emulsion A for Coating Solution >> 70% by mass of silver halide emulsion 1, 15% by mass of silver halide emulsion 2 and 15% by mass of silver halide emulsion 3 were dissolved. Zolium iodide was added as a 1% by mass aqueous solution in an amount of 7 × 10 ⁻³ mol per mol of silver.

<< Preparation of Dispersion of Fatty Acid Silver >> Behenic acid (manufactured by Henkel, product name: Edenor C22-85R) 8
7.6 kg, 423 L of distilled water, 5 mol / L concentration of Na
49.2 L of OH aqueous solution, 120 L of tert-butanol
Were mixed and reacted at 75 ° C. for 1 hour with stirring to obtain a sodium behenate solution. Separately, 206.2 L (pH 4.0) of an aqueous solution of 40.4 kg of silver nitrate was prepared and kept at 10 ° C. A reaction vessel containing 635 L of distilled water and 30 L 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 supplied at constant flow rates of 93 minutes, 15 seconds and 90 minutes, respectively. And added. At this time, only the aqueous silver nitrate solution was added for 11 minutes 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 14 minutes and 15 seconds. I was doing it. 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 allowed to stir at the same temperature for 20 minutes, and the temperature was lowered to 25 ° C. Thereafter, the solid content was separated by centrifugal filtration, and the solid content was washed with water until the conductivity of the filtered water became 42 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.
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 prescribed in the text) 7.4 g of polyvinyl alcohol (trade name: PVA-217) for a wet cake having a dry solid content of 100 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, Microfluidics International
The pressure of the G10Z interaction chamber manufactured by Corporation was adjusted to 1750 kg / cm ² ,
After three treatments, a silver behenate dispersion was obtained. In the cooling operation, a coiled heat exchanger was mounted before and after the interaction chamber, and the dispersion temperature was set at 18 ° C. by adjusting the temperature of the refrigerant.

<< Preparation of 25% by Mass Dispersion of Reducing Agent >>
10 kg of 1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval MP
16 kg of water was added to 10 kg of the 20% by mass aqueous solution of 203) and mixed well to form a slurry. The 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 30 minutes, and then sodium 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 reducing agent dispersion thus obtained had a median diameter of 0.42 μm and a maximum particle diameter of 2.0 μm or less. The resulting reducing agent dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of 25% by Mass Dispersion of Reducing Agent Complex >>
2,2-methylenebis- (4-ethyl-6-tert-
16 kg of water was added to 10 kg of a 1: 1 complex of butylphenol) and triphenylphosphine oxide and 10 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 fed by a diaphragm pump and filled with zirconia beads having an average diameter of 0.5 mm in a horizontal sand mill (manufactured by Imex Co., Ltd., UVM-
After dispersing for 3 hours and 30 minutes in 2), 0.2 g of benzoisothiazolinone sodium salt 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 thus obtained reducing agent complex dispersion had a median diameter of 0.46 μm and a maximum particle diameter of 2.0.
μm or less. The obtained reducing agent complex dispersion was treated with a pore size of 1
The mixture was filtered with a 0.0 μm polypropylene filter to remove foreign substances such as dust, and stored.

<< Preparation of 10% by mass dispersion of mercapto compound >> 1-phenyl-2-heptyl-5-mercapto-
5 kg of 1,3,4-triazole and 20 of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.)
8.3 kg of water was added to 5 kg of a mass% aqueous solution and mixed well to form a slurry. This slurry was sent by a diaphragm pump and filled with zirconia beads having an average diameter of 0.5 mm in a horizontal sand mill (manufactured by Imex Co., Ltd.).
After dispersion for 6 hours in UVM-2), water was added to adjust the concentration of the mercapto compound to 10% by mass,
A mercapto dispersion was obtained. The mercapto compound particles contained in the mercapto compound dispersion thus obtained had a median diameter of 0.40 μm and a maximum particle diameter of 2.0 μm or less. The resulting mercapto compound dispersion was filtered with 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 20% by Mass Dispersion-1 of Organic Polyhalogen Compound >> Tribromomethylnaphthyl sulfone 5
and 2.5 kg of a 20% by mass aqueous solution of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.) and 20 kg of sodium triisopropylnaphthalenesulfonate.
213 g of a mass% aqueous solution and 10 kg of water were added and mixed well to form a slurry. This slurry was sent by a diaphragm pump and filled with zirconia beads having an average diameter of 0.5 mm in a horizontal sand mill (manufactured by Imex Co., Ltd.).
After dispersing for 5 hours with UVM-2), 0.2 g of benzoisothiazolinone sodium salt and water were added to adjust the concentration of the organic polyhalogen compound to 20% by mass.
An organic polyhalogen compound dispersion was obtained. Organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained had a median diameter of 0.36 μm and a maximum particle diameter of 2.0.
μm or less. The resulting organic polyhalogen compound dispersion 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 25% by mass dispersion of organic polyhalogen compound-2 >> 20% by mass of organic polyhalogen compound
Same as Dispersion-1, except that 5 kg of tribromomethylnaphthyl sulfone was used instead of tribromomethyl (4-
5 kg of (2,4,6-trimethylphenylsulfonyl) phenyl) sulfone was dispersed, diluted so that the organic polyhalogen compound became 25% by mass, and filtered. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained had a median diameter of 0.3.
8 μm, and the maximum particle size was 2.0 μm or less. The resulting organic polyhalogen compound dispersion 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 26% by mass of organic polyhalogen compound dispersion-3 >> 20% by mass of organic polyhalogen compound
Similar to Dispersion-1, except that 5 kg of tribromomethylphenylsulfone was used instead of 5 kg of tribromomethylnaphthylsulfone,
kg and dispersed.
It diluted so that it might be set to mass%, and filtered. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained 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 was filtered with 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 25% by mass dispersion of organic polyhalogen compound-4 >> 20% by mass of organic polyhalogen compound
Similar to Dispersion-1, except that 5 kg of N-butyl-3-tribromomethanesulfonylbenzamide was used instead of 5 kg of tribromomethylnaphthylsulfone for dispersion,
This organic polyhalogen compound was diluted to 25% by mass and filtered. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained 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 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 5% by mass solution of phthalazine compound >> 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 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate was added. 14.28 kg of a 70% by mass aqueous solution of 6-isopropylphthalazine was added to prepare a 5% by mass solution of 6-isopropylphthalazine.

<< Preparation of 20% by Mass Dispersion of Pigment >> CIPi
gment Blue 60 (64 g) and Kao Corporation's Demol N (6.4 g) were mixed with water (250 g) and mixed well to form a slurry. 800 g of zirconia beads with an average diameter of 0.5 mm
Was put into a vessel together with the slurry, and dispersed in a dispersing machine (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) for 25 hours to obtain a pigment dispersion. The pigment particles contained in the pigment dispersion thus obtained have an average particle size of 0.1.
It was 21 μm.

<< Preparation of SBR latex 40% by mass >>
The above SBR latex diluted 10 times with distilled water
For ultrafiltration (UF) purification FS03-FC-
FUY03A1 (Daisen Membrane System)
(Ion) to 1.5 mS / cm.
And then purify it with a non-fluorinated surfactant (Sanyo Chemical Co., Ltd.)
0.22% by mass of Sandet-BL manufactured by Co., Ltd.
Was added. NaOH and NH_FourNa with OH⁺
Ion: NH _Four ⁺Ions = 1: 2.3 (molar ratio)
And adjusted to pH 8.4. Latek at this time
Concentration was 40% by mass. (SBR latex: -St (68) -Bu (29)-
AA (3)-latex, Tg = 17 ° C.) Average particle size 0.1 μm, concentration 45% by mass, 25 ° C., relative humidity
0.6% equilibrium water content at 60% degree, ionic conduction
4.2mS / cm (Ion conductivity is measured by Toa Denko
Using a conductivity meter CM-30S manufactured by Sangyo Co., Ltd.
Liquid (40% by mass) at 25 ° C.), pH 8.2

<< Preparation of Coating Solution for Image Forming Layer >> 1.1 g of a 20% by mass dispersion of the pigment obtained above and a fatty acid silver dispersion 10 were prepared.
3 g, 5 g of a 20% by weight aqueous solution of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.), 25 g of a 25% by weight dispersion of a reducing agent, and an organic polyhalogen compound dispersion-1,
SBR latex (T) purified by ultrafiltration (UF) and pH-adjusted to give a total amount of 14.0, 6.2 g of a 10% by mass dispersion of a mercapto compound in 5: 1: 3 (mass ratio) of -2- and -3 (mass ratio).
g: 17 ° C.) 106 g of 40% by mass and 18 ml of a 5% by mass solution of a phthalazine compound were added, and immediately before coating, 10 g of silver halide mixed emulsion A was well mixed and coated on an image forming layer (emulsion layer, photosensitive layer). The liquid was directly sent to the coating die at 70 ml / m ² and applied. The viscosity of the coating solution for the image forming layer was measured at 40 ° C. (No. 1 rotor, 60 rpm) at 85 ° C. using a B-type viscometer of Tokyo Keiki.
[MPa · s]. The viscosity of the coating solution at 25 ° C. using an RFS Fluid Spectrometer manufactured by Rheometrics Far East Co., Ltd.
1500, 220, 70, 40, and 20 [mPa · s] at 1, 10, 100, and 1000 [1 / sec]
Met.

<< Preparation of Coating Solution for Intermediate Layer on Image Forming Surface >> Polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.)
4. 772 g of 0% by mass aqueous solution, 20% by mass dispersion of pigment
3 g of a 2,7.5 mass% liquid of methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20/5/2) latex was mixed with 1,2-di (2 2 ml of a 5% by mass aqueous solution of -ethylhexyloxycarbonyl) ethanesulfonic acid, 10.5 ml of a 20% by mass aqueous solution of diammonium phthalate, and a total amount of 880
g, and add N to adjust the pH to 7.5.
The solution was adjusted with aOH to prepare a coating solution for the intermediate layer, and the solution was fed to a coating die at a concentration of 10 ml / m ² . The viscosity of the coating solution is 40 ° C. using a B-type viscometer (No. 1 rotor, 60 rpm).
Was 21 [mPa · s].

<< Preparation of Coating Solution for First Layer of Image Forming Surface Protective Layer >>
64 g of inert gelatin was dissolved in water, and 27.5% by mass of methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20/5/2) latex was used.
80 g of the liquid, 30% methanol solution of phthalic acid in 30%
ml, 10 mass% aqueous solution of 4-methylphthalic acid 15m
1, 28 ml of 0.5 mol / L sulfuric acid, 1,2-
5 ml of a 5% by weight aqueous solution of sodium di (2-ethylhexyloxycarbonyl) ethanesulfonate, 0.5 g of phenoxyethanol, 0.1 g of benzoisothiazolinone
g of water, and water was added to make a total amount of 750 g to obtain a coating liquid. 26 ml of 4% by mass chromium alum was mixed with a static mixer immediately before coating to obtain 18.6 ml / ml.
The solution was sent to the coating die so as to obtain m ² . The viscosity of the coating solution was measured using a B-type viscometer at 40 ° C. (No. 1 rotor, 60 r
pm) was 17 [mPa · s].

<< Preparation of Coating Solution for Second Layer of Image Forming Surface Protective Layer >>
80 g of inert gelatin is dissolved in water, and 27.5% by mass of methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20/5/2) latex
Liquid 102 g, N-perfluorooctylsulfonyl-N
3.2% by weight of a 5% by weight solution of potassium propylalanine salt.
32 ml of a 2% by weight aqueous solution of polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [average degree of polymerization of ethylene oxide = 15], 1,2-di (2-ethylhexyloxycarbonyl) ) 23 ml of a 5% by mass solution of sodium ethanesulfonate, 4 g of polymethyl methacrylate fine particles (average particle size 0.7 μm), 21 g of polymethyl methacrylate fine particles (average particle size 4.5 μm), 1.6 g of 4-methylphthalic acid, phthalate 4.8 g of acid, 0.5 mo
44 ml of 1 / L sulfuric acid, benzoisothiazolinone 1
0 mg of water was added to make a total amount of 650 g, and 445 ml of an aqueous solution containing 4% by mass of chromium alum and 0.67% by mass of phthalic acid were mixed with a static mixer immediately before coating, and the coating solution for the surface protective layer was applied. 8.3 ml
/ M ² to the coating die. The viscosity of the coating solution was measured using a B-type viscometer at 40 ° C (No. 1 rotor, 60
rpm] was 9 [mPa · s].

<< Preparation of Photothermographic Material-1 >> The anti-halation layer coating solution was applied on the back surface side of the undercoat support so that the coating amount of the solid fine particle dye was 0.04 g / m ^2. The backside protective layer coating solution was coated simultaneously with a multilayer so that the gelatin coating amount was 1.7 g / m ^2, and dried,
A back layer was prepared. The image forming layer (a silver halide coating amount of 0.14 g / m 2)
² ), an intermediate layer, a protective layer first layer, and a protective layer second layer were simultaneously coated in order by a slide bead coating method to prepare a photothermographic material sample. The coating and drying conditions are as follows. The coating is performed at a speed of 160 m / min, and the gap between the tip of the coating die and the support is set to 0.10 to 0.30.
mm, and the pressure in the decompression chamber is 196 to 88 with respect to the atmospheric pressure.
It was set lower by 2 Pa. The support was neutralized with ion wind before coating. In the subsequent chilling zone, the dry bulb temperature is 10
After cooling the coating liquid with a wind of 20 ° C., the coating liquid is conveyed in a non-contact type, and a dry-bulb temperature of 23 to 23 is supplied by a helix type non-contact drying apparatus.
It was dried with a dry air at 45 ° C and a wet bulb temperature of 15 to 21 ° C.
After drying, after adjusting the humidity at 25 ° C and the relative humidity of 40 to 60%,
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 image forming layer surface side in Beck smoothness,
The back surface was 130 seconds. Further, the pH of the film surface on the photosensitive layer surface side was measured and found to be 6.0.

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[0183]

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<< Preparation of Photothermographic Material-2 >> For the photothermographic material-1, except that the coating solution for the image forming layer was changed as follows and the yellow dye compound 15 of the antihalation layer was removed. A photothermographic material-2 was produced in exactly the same manner as the photothermographic material 1 of Example 1. (Preparation of coating solution for image forming layer) 1.1 g of a 20% by weight aqueous dispersion of the pigment obtained above, 103 g of a fatty acid silver dispersion, and 5 g of a 20% by weight aqueous solution of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.) 26 g of a 25 mass% dispersion of the reducing agent complex, and organic polyhalogen compound dispersions-3 and -4.
: 1: 3 (mass ratio), a total amount of 6.0 g, a 10% dispersion of a mercapto compound 6.2 g, ultrafiltration (UF) purified and pH-adjusted SBR latex (-St (71) -Bu (2
6) Latex of -AA (3)-, Tg: 24 ° C) 40
106% by mass and 18 ml of a 5% by mass solution of a phthalazine compound were added.
And the coating solution of the image forming layer, which is well mixed with 10 g, is directly sent to the coating die at 70 ml / m ² .
Applied.

<< Preparation of Other Photothermographic Materials >> The photothermographic materials 1A to 1C and 2A to 2C are represented by the general formula (A) in the image forming layer with respect to the photothermographic materials 1 and 2, respectively. Was prepared in the same manner as in Photothermographic Materials 1 and 2, except that Compound III-23 was added in the amount shown in Table 1. At this time, the compound represented by the general formula (A) was added as a 5% methanol / water (1/1) solution containing an equimolar amount of aqueous ammonia. Photothermographic material 0
01 is a photothermographic material 1 with respect to the photothermographic material 1
0 is the N-perfluorooctylsulfonyl-N-propylalanine potassium salt and polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl) of the back surface protective layer and the emulsion protective layer second layer with respect to the photothermographic material 2. -2-Aminoethyl) ether [average degree of polymerization of ethylene oxide = 15] was prepared in the same manner as in Table 1, except that the fluorine-based surfactant of the general formula (F) was used in the same mass. Other photothermographic materials (0
02 to 009 and 011 to 018) were adjusted in the same manner as described above with the configuration shown in Table 1. At this time, the compound represented by the general formula (A) is
B was added to the image forming layer in the same molar amount as B.

(Evaluation of photographic performance) Fuji Medical Dry Laser Imager FM-DP L (Max.
(IIIB) A 660 nm semiconductor laser with an output) was used to uniformly expose the photographic material so that the density was around 2.0, and heat development (about 120 ° C.) was performed. 10 m ^{2 of the} obtained sample was visually observed on a Schaukasten, and the number of white spots was examined. The results are shown in Table 1. From the results in Table 1, it was confirmed that white spots can be significantly reduced by using the fluorine-based surfactant of the general formula (F) in combination with the compound of the general formula (A).

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[Table 1]

Example 2 Photothermographic material 0 of Example 1
The reducing agent of the general formula (I) is
Samples changed to 4, 27 were prepared, and the same evaluation as in Example 1 was performed. Also in this case, it was confirmed that the use of a combination of the fluorine-based surfactant of the general formula (F) and the compound of the general formula (A) effectively suppressed the occurrence of white spots.

<Example 3> In the photothermographic materials 1 and 2 of Example 1, the addition amount of the fluorine-based surfactant was reduced to 1/3.
Photothermographic materials 030 and 040 were prepared in the same manner, except that FS-2 and FS-29 were replaced by weight. The photothermographic materials 030 and 040 were prepared in the same manner as the photothermographic materials 030 and 040 except that the compound represented by the general formula (A) and the comparative compound were used in an equimolar amount to the addition amount of the compound III-23 in the photothermographic material 1B. Photothermographic material 031-0
36, 041-046 were produced. Table 2 shows the results of the evaluation performed in the same manner as in Example 1.

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[Table 2]

[0191]

The photothermographic material of the present invention not only has excellent heat developability and image storability, but also sufficiently suppresses adhesion of dust and foreign matter which may cause white spot failure after heat development. can do. Therefore, the photothermographic material of the invention is useful as a film for medical diagnosis or a film for photoengraving.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H123 AB00 AB03 AB23 AB28 AB29 BB00 BB02 BB11 BB17 BB27 BB28 BB39 CB00 CB03 4D077 AA06 AB03 AC05 DC02Y DC72Y

Claims (5)

[Claims] 1. A photothermographic material comprising at least one 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 photothermographic material comprising at least one kind of the surfactant represented by (F) and at least one kind of the compound represented by the following formula (A). General formula (F): Rf- (Rc) nZ [In the general formula (F), Rf represents a perfluoroalkyl group, Rc is an alkylene group, and Z is an anionic group necessary for imparting surface activity. , A group having a cationic group or a nonionic polar group, and n represents an integer of 0 or 1. General formula (A): ZPL- (C = Q) -Y [In general formula (A), P represents an oxygen atom, a sulfur atom, or an NH group. Q represents an oxygen atom or a sulfur atom.
Y represents an OH group, an OM group, an SH group, an SM group (where M represents a counter ion) or an NH ₂ group. L represents an alkylene group. Z represents an alkyl group, an aryl group or a heterocyclic group. ] 2. The photothermographic material according to claim 1, wherein the photothermographic material contains a compound in which n is 1 in the general formula (F). 3. The photothermographic material according to claim 1, wherein the reducing agent is a compound represented by the following general formula (I). General formula (I): [In the general formula (I), R ¹ and R ¹ ′ each independently represent an alkyl group having 1 to 20 carbon atoms. R ² and R ² ′ each independently represent a hydrogen atom or a substituent that can be substituted on a benzene ring. L is -S- group or -CHR ³ - represents a group.
R ³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. X and X ′ each independently represent a hydrogen atom or a group that can be substituted on a benzene ring. ] 4. The photothermographic material according to claim 1, further comprising a compound represented by the following general formula (II). General formula (II): [In the general formula (II), R ¹⁰ , R ¹¹ and R ¹² each independently represent an alkyl group, an aralkyl group, an aryl group, an alkoxy group, an aryloxy group, an amino group or a heterocyclic group. ] 5. The photothermographic material according to claim 1, further comprising a compound represented by the following general formula (III). General formula (III): Q- (Y) nC (Z ¹ ) (Z ² ) X [In the general formula (III), Q represents an alkyl group, an aryl group or a heterocyclic group, and Y is a divalent Represents a linking group,
n represents 0 or 1, Z ¹ and Z ² represent a halogen atom, and X represents a hydrogen atom or an electron-withdrawing group. ]