JPH10197983A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photosensitive material having the good touch when the material is touched with bare hands without the decrease in the effect of a matting agent of spherical silica in spite of heat development at a high temp. by having layers contg. this matting agent of a spherical silica on the surface of a base. SOLUTION: This photosensitive material has at least one layer of the layers contg. the matting agent of the spherical silica on at least one surface of the base. The material has at least one layers of photosensitive layers contg. photosensitive silver halide on at least one surface of the base. Further, the material contains an org. silver salt and a reducing agent for this silver salt. The photosensitive layers are formed by applying a coating liquid prepd. by dispersing a binder contg. >=50wt.% material having an equil. moisture content of <=2wt.% at 25C and 60% RH into a solvent contg. >=30wt.% water on the base, then drying the coating. The average particle size of the matting agent is from 0.5 to 10μm. The photosensitive material otherwise has at least one layer of the layers contg. the matting agents of the spherical silica on both surfaces of the base.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material, and more particularly, to a photothermographic material having no roughness when touched with bare hands.

[0002]

2. Description of the Related Art It is well known that a photosensitive layer is formed on a support and a latent image formed by exposure is converted into a visible image by thermal development.

For example, US Pat. Nos. 3,152,904 and 3,457,075 and D.C. Morgan and B.A.
"Thermal Processed Silver Systems" by Shely (Imaging Processes and Materials (Imag)
ing Processing and Materials) Neblette 8th edition Syurge, V.S. Walworth, A .;
Shepp, 2nd page, 1969).

[0004] These methods meet social demands for simplification of processing and environmental preservation, which have been increasing in recent years.

It is known to add a matting agent to this type of photothermographic material in order to improve transportability and prevent sticking.

For example, JP-A-62-136643 discloses an example in which fine particles of a polymer having a high glass transition temperature, such as polymethyl methacrylate and a styrene-methacrylic acid copolymer, are added as a matt material. 10
JP-A Nos. 4338 and 51-129220 describe a method of adding silica fine particles having an undefined shape as a matting agent.

However, in the former case, when thermal development is performed at a high temperature such as 100 ° C. or higher, there is a problem that the matting agent is deformed during development, and the effect of the matting agent is reduced. In the latter, the surface of the light-sensitive material is rough, and the feel of touching with bare hands is not good.

Accordingly, there has been a demand for a photothermographic material which does not reduce the effect of the matting agent even when subjected to thermal development at a high temperature and has a good feel when touched with bare hands.

[0009]

The problem to be solved by the present invention is that the effect of the matting agent is not reduced even by thermal development at a high temperature, and that the photothermographic material has a good feel when touched with bare hands. Is to provide the material.

[0010]

The above object is achieved by the following (1).
This is achieved by the inventions of (5) to (5). (1) A photothermographic material having at least one layer containing a spherical silica matting agent on at least one surface of a support. (2) At least one surface of the support has at least one photosensitive layer containing photosensitive silver halide, and further contains an organic silver salt and a reducing agent for the silver salt. The photothermographic material according to 1). (3) The photothermographic material according to the above (1) or (2), wherein the photosensitive layer satisfies the following conditions. a. The binder contains 50 wt% or more of a material having an equilibrium water content of 2 wt% or less at 25 ° C. and 60% RH. b. A coating solution in which the above binder is dispersed in a solvent containing 30% by weight or more of water is applied and dried to form a coating solution. (4) The average particle diameter of the matting agent is from 0.5 μm to 10
(1), (2) or (3). (5) The photothermographic material according to the above (2), (3) or (4), wherein at least one layer containing a spherical silica matting agent is provided on both surfaces of the support.

[0011]

DETAILED DESCRIPTION The method of forming photosensitive silver halide in the present invention is well known in the art and is described, for example, in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. Can be used. Specific methods that can be used in the present invention include a method of converting a part of the silver of the organic silver salt to a photosensitive silver halide by adding a halogen-containing compound to the prepared organic silver salt, gelatin. Alternatively, a method of preparing a photosensitive silver halide grain by adding a silver supply compound and a halogen supply compound to another polymer solution and mixing the silver halide compound with an organic silver salt can be used. In the present invention, the latter method can be preferably used. The grain size of the photosensitive silver halide is preferably small for the purpose of suppressing the white turbidity after image formation.
The thickness is preferably 0.20 μm or less, more preferably 0.01 μm or more and 0.15 μm or less, and still more preferably 0.02 μm or more and 0.12 μm or less.
Here, the grain size means the length of the edge of the silver halide grain when the silver halide grain is a cubic or octahedral so-called normal crystal. In the case where the silver halide grains are tabular grains, the diameter refers to a diameter when converted into a circular image having the same area as the projected area of the main surface. In the case of other than normal crystals, for example, in the case of spherical grains, rod-shaped grains, etc., it refers to the diameter of a sphere equivalent to the volume of silver halide grains.

The shape of the silver halide grains is cubic,
Octahedral, tabular particles, spherical particles, rod-like particles, potato-like particles and the like can be mentioned. In the present invention, cubic particles and tabular particles are particularly preferable. When tabular silver halide grains are used, the average aspect ratio is preferably from 100: 1 to 2: 1, more preferably from 50: 1 to 3: 1. Further, grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grain is not particularly limited, but the spectral sensitization efficiency when the spectral sensitizing dye is adsorbed is high.
The proportion occupied by the {100} plane is preferably high. The ratio is preferably 50% or more, more preferably 65% or more, and even more preferably 80% or more. The ratio of the {100} plane of the Miller index is determined by T. Tani; J. Imaging Sci., 29, 165 (198) using the dependence of the adsorption of the sensitizing dye on the {111} and {100} planes.
5 years). There is no particular limitation on the halogen composition of the photosensitive silver halide,
Silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide, any of silver iodide may be used, but in the present invention, silver bromide or silver iodobromide is preferred. Can be used. Particularly preferred is silver iodobromide, and the silver iodide content is preferably from 0.1 mol% to 40 mol%,
More preferably, it is not less than 20 mol% and not more than 20 mol%. The distribution of the halogen composition in the grains may be uniform, the halogen composition may be changed stepwise, or may be changed continuously, but as a preferable example, the silver iodide content inside the grains is High silver iodobromide grains can be used. Preferably, silver halide grains having a core / shell structure can be used. As the structure, core / shell particles having preferably a 2- to 5-layer structure, more preferably a 2- to 4-layer structure, can be used.

The photosensitive silver halide grains of the present invention preferably contain at least one complex of a metal selected from rhodium, rhenium, ruthenium, osmium, iridium, cobalt, mercury or iron. One of these metal complexes may be used, or two or more complexes of the same metal and different metals may be used in combination. The preferable content is in the range of 1 nmol to 10 mmol, and more preferably in the range of 10 nmol to 100 μmol per 1 mol of silver. As a specific structure of the metal complex, a metal complex having a structure described in JP-A-7-225449 or the like can be used. As the compound of cobalt and iron, a hexacyano metal complex can be preferably used. Specific examples include ferricyanate ion, ferrocyanate ion, hexacyanocobaltate ion, and the like, but are not limited thereto. The phase containing the metal complex in the silver halide may be uniform, may be contained in the core at a high concentration, or may be contained in the shell at a high concentration, and there is no particular limitation.

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

The photosensitive silver halide grains in the present invention are preferably chemically sensitized. As a preferred chemical sensitization method, a sulfur sensitization method, a selenium sensitization method, and a tellurium sensitization method are well known in the art. Further, a noble metal sensitization method or a reduction sensitization method of a gold compound, platinum, palladium, an iridium compound or the like can be used. As the compound preferably used in the sulfur sensitization method, the selenium sensitization method, and the tellurium sensitization method, known compounds can be used, and the compounds described in JP-A-7-128768 can be used. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides,
Bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, compounds having a P = Te bond,
Tellurocarboxylates, Te-organyltellurocarboxylates, di (poly) tellurides, tellurides,
Tellurols, telluroacetals, tellursulfonates, compounds having a P-Te bond, Te-containing heterocycles, tellurocarbonyl compounds, inorganic tellurium compounds, colloidal tellurium, and the like can be used. Compounds preferably used in the noble metal sensitization method include, for example, chloroauric acid, potassium chloroaurate, potassium aurithiocyanate,
Gold sulfide, gold selenide, or US Patent 2,448,060
And the compounds described in British Patent No. 618,061 can be preferably used. Specific compounds of the reduction sensitization method include, as well as ascorbic acid, thiourea dioxide, for example, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds,
A polyamine compound or the like can be used. Reduction sensitization can be achieved by ripening the emulsion while maintaining the pH of the emulsion at 7 or more or the pAg at 8.3 or less. Further, reduction sensitization can be achieved by introducing a single addition portion of silver ion during grain formation.

The amount of the photosensitive silver halide used in the present invention is preferably 0.01 mol 0.5 mol or less, more preferably 0.02 mol or more and 0.3 mol or less, and more preferably 0.03 mol or less with respect to 1 mol of the organic silver salt. Particularly preferred is 0.25 mol or less. Regarding the mixing method and the mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the prepared silver halide particles and organic silver salt are mixed with a high-speed stirrer, ball mill, sand mill, colloid mill, vibration mill, homogenizer, etc. There is a method of mixing, 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 it appears.

As the silver halide preparation method of the present invention, a so-called halation method in which a part of silver of an organic silver salt is halogenated with an organic or inorganic halide is also preferably used. The organic halide used here may be any compound as long as it is a compound which reacts with an organic silver salt to form a silver halide, and includes N-halogenoimide (N-bromosuccinimide and the like), quaternary nitrogen halide (e.g. Tetrabutylammonium bromide, etc.), and an association of a quaternary nitrogen halide and a halogen molecule (pyridinium perbromide). As the inorganic halogen compound, any compound may be used as long as it reacts with an organic silver salt to form a silver halide, and an alkali metal or ammonium halide (such as sodium chloride, lithium bromide, potassium iodide, and ammonium bromide) ), Alkaline earth metal halides (such as calcium bromide and magnesium chloride), transition metal halides (such as ferric chloride and cupric bromide), and metal complexes having a halogen ligand (sodium iridium bromide) , Ammonium rhodate, etc.), and halogen molecules (bromine, chlorine, iodine). Further, a desired organic / inorganic halide may be used in combination.

In the present invention, the amount of the halide to be added is preferably 1 to 500 mmol, more preferably 10 to 25 mmol, as a halogen atom per 1 mol of the organic silver salt.
0 mmol is more preferred.

The organic silver salt that can be used in the present invention includes:
Relatively stable to light, but in the presence of an exposed photocatalyst (such as a latent image of photosensitive silver halide) and a reducing agent,
A silver salt that forms a silver image when heated to 80 ° C. or higher. The organic silver salt can be any organic substance including a source capable of reducing silver ions. Silver salts of organic acids, especially (
Silver salts of long chain fatty carboxylic acids having 10 to 30, preferably 15 to 28 carbon atoms are preferred. Also preferred are organic or inorganic silver salt complexes in which the ligand has a complex stability constant in the range of 4.0 to 10.0. The silver donor material can preferably comprise about 5-70% by weight of the imaging layer. Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. Examples of these include, but are not limited to, silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the silver salt of an aliphatic carboxylic acid include silver behenate,
Silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate, silver fumarate, silver tartrate, silver linoleate, silver butyrate and silver camphorate, mixtures thereof, etc. including.

Silver salts of compounds containing a mercapto group or a thione group and derivatives thereof can also be used. Preferred examples of these compounds include 3-mercapto-4-
Silver salt of phenyl-1,2,4-triazole, silver salt of 2-mercaptobenzimidazole, silver salt of 2-mercapto-5-aminothiadiazole, silver salt of 2- (ethylglycolamide) benzothiazole, S-alkylthio Silver salts of thioglycolic acid such as silver salts of glycolic acid (where the alkyl group has 12 to 22 carbon atoms); silver salts of dithiocarboxylic acids such as silver salts of dithioacetic acid; silver salts of thioamide; Silver salt of carboxyl-1-methyl-2-phenyl-4-thiopyridine, silver salt of mercaptotriazine, silver salt of 2-mercaptobenzoxazole, silver salt described in U.S. Pat.No. 4,123,274,
For example, a silver salt of a 1,2,4-mercaptothiazole derivative such as a silver salt of 3-amino-5-benzylthio-1,2,4-thiazole,
Silver salts of thione compounds such as the silver salt of 3- (3-carboxyethyl) -4-methyl-4-thiazoline-2-thione described in U.S. Pat. No. 3,301,678. Furthermore, compounds containing an imino group can also be used. Preferred examples of these compounds include silver salts of benzotriazole and derivatives thereof, for example, silver salts of benzotriazole such as silver methylbenzotriazole, silver salts of halogen-substituted benzotriazole such as silver 5-chlorobenzotriazole, and US Pat. No. 4,220,709, silver salts of 1,2,4-triazole or 1-H-tetrazole, and silver salts of imidazole and imidazole derivatives. For example, U.S. Pat.
Various silver acetylide compounds as described in 1,361 and 4,775,613 can also be used.

The shape of the organic silver salt that can be used in the present invention is not particularly limited, but a needle-like crystal having a short axis and a long axis is preferable. In the present invention, the minor axis is 0.01 μm or more.
20 μm or less, major axis 0.10 μm or more and 5.0 μm or less, short axis 0.01 μm or more and 0.15 μm or less, major axis 0.10 μm or more
It is more preferably 4.0 μm or less. The particle size distribution of the organic silver salt is preferably monodispersed. The monodispersion is a percentage of the standard deviation of the lengths of the minor axis and major axis divided by the minor axis and major axis, respectively, preferably 100% or less, more preferably 80% or less, and even more preferably 50%. 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 of measuring monodispersity is to determine the standard deviation of the volume-weighted average diameter of the organic silver salt,
The percentage (coefficient of variation) is preferably 100% or less, more preferably 80% or less, and further preferably 50% or less. As a measurement method, for example, a particle size obtained by irradiating a laser beam to an organic silver salt dispersed in a liquid and obtaining an autocorrelation function with respect to a time change of fluctuation of the scattered light (
Volume load average diameter).

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

For the purpose of obtaining fine particles having a small particle size and no aggregation, an organic silver salt which can be used in the present invention is a method of preparing a solid fine particle dispersion using a dispersant. The method of dispersing the organic silver salt into solid fine particles is carried out by using a known fine means (for example, a ball mill, a vibrating ball mill, a planetary ball mill, a sand mill, a colloid mill, a jet mill, a roller mill) in the presence of a dispersing agent. Can be dispersed.

When the organic silver salt is formed into solid fine particles by using a dispersant, for example, polyacrylic acid, a copolymer of acrylic acid, a maleic acid copolymer, a maleic acid monoester copolymer, and acryloylmethyl Synthetic anionic polymers such as propane sulfonic acid copolymer, semi-synthetic anionic polymers such as carboxymethyl starch and carboxymethyl cellulose, anionic polymers such as alginic acid and pectic acid, JP-A-52-92716, WO88 / 04794, etc. Anionic surfactant described, the compound described in Japanese Patent Application No. 7-350753, or known anionic, nonionic,
Cationic surfactants and other known polymers such as polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose, or naturally occurring polymer compounds such as gelatin can be appropriately selected and used. .

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

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

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

The organic silver salt of the present invention can be used in a desired amount, but is preferably 0.1 to 5 g / m ² , more preferably 1 to 3 g / m ^2.
/ M ² .

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

In a photothermographic material utilizing an organic silver salt, a wide range of reducing agents are disclosed in JP-A-46-6074 and JP-A-47-1238.
No. 47-33621, No. 49-46427, No. 49-115540, No.
50-14334, 50-36110, 50-147711, 51-326
No. 32, No. 51-1023721, No. 51-32324, No. 51-51933,
52-84727, 55-108654, 56-146133, 57
-82828, 57-82829, JP-A-6-3793, U.S. Patent No.
3,667,9586, 3,679,426, 3,751,252,
No. 3,751,255, No. 3,761,270, No. 3,782,949
No. 3,839,048, No. 3,928,686, No. 5,464,
No. 738, German Patent No. 2321328 and European Patent No. 692732. For example, amide oximes such as phenylamidooxime, 2-thienylamidooxime and p-phenoxyphenylamidooxime; azines such as 4-hydroxy-3,5-dimethoxybenzaldehydeazine; 2,2′-bis (hydroxymethyl) propionyl -a combination of an aliphatic carboxylic acid aryl hydrazide such as a combination of β-phenylhydrazine and ascorbic acid and ascorbic acid; a combination of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine (for example, hydroquinone and bis (ethoxy) Ethyl) hydroxylamine, piperidinohexose reductone or a combination of formyl-4-methylphenylhydrazine, etc.); phenylhydroxamic acid, p-hydroxyphenylhydroxamic acid and β-alinine hydroxam Hydroxamic acids such as acids; combinations of azines and sulfonamidophenols (eg, phenothiazine with 2,6-
Dichloro-4-benzenesulfonamidophenol etc.)
Α- such as ethyl-α-cyano-2-methylphenylacetate and ethyl-α-cyanophenylacetate;
Cyanophenylacetic acid derivative; 2,2'-dihydroxy-1,1'-
Binaphthyl, 6,6'-dibromo-2,2'-dihydroxy-1,1'-
Bis-β-naphthol as exemplified by binaphthyl and bis (2-hydroxy-1-naphthyl) methane; bis-
a combination of β-naphthol and a 1,3-dihydroxybenzene derivative (eg, 2,4-dihydroxybenzophenone or 2 ′, 4′-dihydroxyacetophenone); 3-methyl-1
5-pyrazolone, such as phenyl-5-pyrazolone; reductones as exemplified by dimethylaminohexose reductone, anhydrodihydroaminohexose reductone and anhydrodihydropiperidone hexose reductone; 2,6- Sulfonamidophenol reducing agents such as dichloro-4-benzenesulfonamidophenol and p-benzenesulfonamidophenol; 2-phenylindane-1,3-dione; 2,2-dimethyl-7-t-butyl-6
-Chromans such as hydroxychroman; 2,6-dimethoxy
-3,5-dicarbethoxy-1,4-dihydropyridine
1,4-dihydropyridine; bisphenol (for example, bis
(2-hydroxy-3-t-butyl-5-methylphenyl) methane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-ethylidene-bis (2-t-butyl-6 -Methylphenol), 1,1, -bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and 2,2-bis
(3,5-dimethyl-4-hydroxyphenyl) propane, etc.); ascorbic acid derivatives (for example, 1-palmitic acid)
And aldehydes and ketones such as benzyl and biacetyl; 3-pyrazolidone and certain indane-1,3-
Dione; chromanol (such as tocopherol). Particularly preferred reducing agents are bisphenol and chromanol.

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

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

In a photothermographic material using an organic silver salt, a wide range of color toning agents are disclosed in JP-A-46-6077 and JP-A-47-10282.
Nos. 49-5019, 49-5020, 49-91215, 49
-91215, 50-5024, 50-32927, 50-67132
No. 50-67641, No. 50-114217, No. 51-3223, No. 5
1-27923, 52-14788, 52-99813, 53-1020
No. 53-76020, No. 54-156524, No. 54-156525,
No. 61-183642, JP-A-4-56848, JP-B-49-10727
No. 54-20333, U.S. Pat.Nos. 3,080,254, 3,446,64
No. 8, 3,782,941, 4,123,282, 4,510,236
And British Patent 1380795 and Belgian Patent 841910. Examples of toning agents are phthalimide and N-
Hydroxyphthalimide; succinimide, pyrazoline
And cyclic imides such as quinazolinone, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione; naphthalimides (eg, N-hydroxy-1 , 8-naphthalimide); cobalt complex (eg, cobalt hexamine trifluoroacetate); 3-mercapto-1,2,4-triazole, 2,4-dimercaptopyrimidine, 3-mercapto-4,5
Mercaptans exemplified by --diphenyl-1,2,4-triazole and 2,5-dimercapto-1,3,4-thiadiazole; N- (aminomethyl) aryldicarboximides;
(For example, (N, N-dimethylaminomethyl) phthalimide and N, N- (dimethylaminomethyl) -naphthalene-2,3-
Dicarboximides); and blocked pyrazoles, isothiuronium derivatives and certain photobleaching agents (
For example, N, N-hexamethylenebis (1-carbamoyl-3,5
-Dimethylpyrazole), 1,8- (3,6-diazaoctane)
Bis (isothiuronium trifluoroacetate) and 2-tribromomethylsulfonyl)-(benzothiazole)); and 3-ethyl-5 [(3-ethyl-2-benzothiazolinylidene) -1-methylethylidene] 2-thio-2,4-oxazolidinedione; phthalazinone, a phthalazinone derivative or a metal salt, or 4- (1-naphthyl) phthalazinone;
Derivatives such as 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone and 2,3-dihydro-1,4-phthalazinedione; phthalazinone and phthalic acid derivatives (for example, phthalic acid, 4-methylphthalic acid, Phthalazine, phthalazine derivatives or metal salts, or 4- (1-naphthyl)
Derivatives such as phthalazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine;
Combinations of phthalazine and phthalic acid derivatives (e.g., phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride, etc.); quinazolinedione, benzoxazine or naphthoxazine derivatives; Rhodium complexes which also serve as a source of halide ions for silver halide formation in situ, such as ammonium hexachlororhodate (III), rhodium bromide, rhodium nitrate and potassium hexachlororhodate (III); inorganic peroxides and Persulfate,
For example, ammonium disulfide and hydrogen peroxide;
1,3-benzoxazine-2,4-dione, 8-methyl-1,3-
Benzoxazines such as benzoxazine-2,4-dione and 6-nitro-1,3-benzoxazine-2,4-dione
2,4-diones; pyrimidines and asymmetric triazines (eg, 2,4-dihydroxypyrimidine, 2-hydroxy-4-
Aminopyrimidine, etc.), azauracil, and tetraazapentalene derivatives (e.g., 3,6-dimercapto-1,4
-Diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene and 1,4-di (o-chlorophenyl) -3,6-dimercapto-1H, 4H-2,3a, 5,6a- Tetraazapentalene).

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

In the present invention, a spherical silica matting agent is added to any of the layers constituting the photothermographic material. Preferred additive layers include a surface protective layer, a back layer, and a back protective layer. It is particularly preferable to add the compound to the surface protective layer and the back protective layer.

The matting agent for spherical silica that can be used in the present invention is spherical fine silica particles.

As used herein, the term “true sphere” means that the average value of the entire particles is (r), which is the ratio (r) of the major axis (a) of a photographed image of the particles to the diameter (b) of a circle having the same area as the image. .2 or less. Practically, it is determined by the following method.

The matting agent was photographed with a scanning electron microscope, and the major axis (a) and the diameter (b) of a circle having the same area as the image of 100 particles were measured, and the r of each particle was calculated. The average value R of r of 100 particles is determined, and when this value is 1.2 or less, it is determined that the matting agent is spherical.

Average particle size of spherical silica matting agent usable in the present invention (average value D over particles having the above-mentioned b value)
Is 0.3 to 20 μm, more preferably 0.5 to 10 μm
Is preferred.

If the average particle size is too small, the effect of the matting agent is lost. On the other hand, if it is too large, the matting agent will peel off or white spot failure will occur, which is inconvenient. In the true spherical silica matting agent of the present invention, it is preferable that the particle size distribution width of the particles is small. It is preferable that 60% or more of all the particles are in the range of 0.7D to 1.3D, more preferably 60% or more of the average particle diameter D is in the range of 0.8D to 1.2D. In order to reduce the particle size distribution width of the particles, classification may be performed by a method such as wet sedimentation classification or air classification.

The spherical silica matting agent of the present invention may be subjected to a surface treatment as required. Various methods are known for surface treatment. For example, silane coupling agent treatment,
There are a titanium coupling agent treatment and a method utilizing mechanochemistry, and the silane coupling agent treatment is a preferable method.

The amount of the matting agent of the present invention varies depending on the thickness of the photothermographic material and the particle size of the matting agent used, but cannot be specified unconditionally, but is preferably 5 to 200 mg / m ² , more preferably 10 to 100 mg / m ² . m ² is preferred. If the addition amount is too small, the effect of the matting agent is not obtained, and if it is too large, haze worsens, which is inconvenient.

The binder of the layer to which the spherical silica matting agent is added is not particularly limited. Both a hydrophobic polymer and a hydrophilic polymer are preferably used. Examples of the hydrophobic polymer include polyvinyl butyrate, cellulose acetate, polystyrene, and vinyl chloride. Examples of the hydrophilic polymer include gelatin, polyvinyl alcohol, casein, agar, methylcellulose, ethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose.

As the binder for the intermediate layer, a latex of a polymer such as ethyl acrylate may be added in addition to the hydrophilic polymer.

The thickness of the layer to which the spherical silica matting agent is added is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm. This layer is preferably formed by applying the above-mentioned aqueous coating solution and then drying. In this layer, if necessary, an organic silver salt, a reducing agent for the silver salt, a color tone agent, an antifoggant,
A crosslinking agent, a dye, a surfactant, and the like may be added. If necessary, crosslinking may be performed with a crosslinking agent. As the cross-linking agent, a compound known as a cross-linking agent for a hydrophilic polymer such as active halogen, vinyl sulfone, or epoxy can be used.

As the binder for the emulsion layer in the present invention, well-known natural or synthetic resins such as gelatin, polyvinyl acetal, polyvinyl chloride,
Any one can be selected from polyvinyl acetate, cellulose acetate, polyolefin, polyester, polystyrene, polyacrylonitrile, polycarbonate and the like. Of course, copolymers and terpolymers are also included. Preferred polymers are polyvinyl butyral, butyl ethyl cellulose, methacrylate copolymer, maleic anhydride copolymer, polystyrene and butadiene-styrene copolymer. If necessary, two or more of these polymers can be used in combination. Such a polymer is used in an amount sufficient to hold the components therein. That is, it is used in a range effective to function as a binder.

As the binder of the emulsion layer in the present invention, a binder in which a hydrophobic polymer is dispersed in an aqueous solvent may be used. The term "aqueous solvent" used here means water or 70 wt% in water.
Less than 50 wt% of a water-miscible organic solvent. Examples of the water-miscible organic solvent include methanol, ethanol, propanol, ethyl acetate, dimethylformamide, methylcellosolve, butylcellosolve and the like. In addition, "dispersion" here
The term refers to a state in which a polymer is not thermodynamically dissolved in a solvent but is dispersed in an aqueous solvent in a latex, micelle state, or molecular dispersion state. The lower limit of the equilibrium water content of the binder in the present invention is not particularly limited, but is preferably 0.01% by weight, more preferably 0.03% by weight. Those having an “equilibrium moisture content at 25 ° C. and 60% RH” of 2 wt% or less are particularly preferred. Here, “equilibrium moisture content at 25 ° C. and 60% RH” means 25 ° C.
In a 0% RH atmosphere, the polymer weights W ₁ and
It can be expressed by the following equation using the weight W ₀ of the polymer in an absolutely dry state at 5 ° C. “Equilibrium moisture content at 25 ° C. and 60% RH” = ｛(W ₁ −
W ₀ ) / W ₀ ｝ × 100 (wt%)

In the present invention, it is preferable that a polymer satisfying this condition is contained in the binder in an amount of 50% by weight or more.

The polymer of the present invention is not particularly limited as long as it can be dispersed in the above-mentioned aqueous solvent. For example, acrylic resin, polyester resin, polyurethane resin, vinyl chloride resin, vinylidene chloride resin, rubber resin (for example, SBR)
Resin, NBR resin, etc.), vinyl acetate resin, polyolefin resin, polyvinyl acetal resin, and the like. The polymer may be a homopolymer or a copolymer in which two or more monomers are polymerized. The polymer may be linear or branched. Further, the polymers may be crosslinked. The number average molecular weight of the polymer is preferably from 1,000 to 1,000,000, more preferably from 3,000 to 500,000. Those having a number average molecular weight of less than 1000 generally have low film strength after coating, and may cause inconvenience such as cracking of the photosensitive material. Specific examples of the polymer of the present invention include acrylic resins such as Sebian A-4635, 46583, and 4601.
(Daicel Chemical Industries, Ltd.), Nipol LX
8111, 814, 820, 821, 857 (all manufactured by Nippon Zeon Co., Ltd.), and FINETEX ES650, 611, 679, 67 as polyester resins.
5, 525, 801, and 850 (all manufactured by Dainippon Ink and Chemicals, Inc.), Wdsize WMS (manufactured by Eastman Chemical), and the like. Dainippon Ink Co., Ltd.), Nipol LX2507, 4
16, 433 (all manufactured by Nippon Zeon Co., Ltd.). The binder of the present invention can be used alone or in a mixture of a plurality of these polymers.

The effective range can be appropriately determined by those skilled in the art. As a guide when at least the organic silver salt is retained, the ratio of the binder to the organic silver salt is 1 by weight.
The range of 5: 1 to 1: 3, particularly 8: 1 to 1: 2 is preferred.

The photothermographic emulsion of the present invention comprises one or more layers on a support. One layer construction must include optional additional materials such as organic silver salts, silver halides, developers and binders, and toning agents, coating aids and other auxiliaries. The two-layer construction is such that the first emulsion layer (usually the layer adjacent to the base) contains an organic silver salt and silver halide, and the second layer or both layers do not contain some other components. No. However, a two-layer construction comprising a single emulsion layer containing all components and a protective topcoat is also contemplated. The construction of a multicolor photothermographic material may include a combination of these two layers for each color, or may include all components in a single layer as described in U.S. Pat. No. 4,708,928. Is also good.
In the case of a multi-dye, multi-color photothermographic material, each emulsion layer is
Generally, they are kept distinct from each other by using a functional or non-functional barrier layer between each photosensitive layer, as described in U.S. Pat. No. 4,460,681.

Various dyes can be used in the photosensitive layer of the present invention from the viewpoint of improving color tone and preventing irradiation. As the dye used in the photosensitive layer of the present invention, any dye may be used, for example, pyrazoloazole dye, anthraquinone dye, azo dye, azomethine dye, oxonol dye, carbocyanine dye, styryl dye, triphenylmethane dye, indolaniline Dyes and indophenol dyes. Preferred dyes used in the present invention include anthraquinone dyes (for example, see JP-A-5-3
Compounds 1 to 9 described in No. 41441, JP-A-5-1651
Compounds 3-6 to 18 and 3-23 to 38 described in No. 47
Azomethine dyes (compounds 17 to 47 described in JP-A-5-341441), indoaniline dyes (for example, compounds 11 to 19 described in JP-A-5-289227).
Compound 47 described in JP-A-5-341441;
And azo dyes (compounds 10 to 16 described in JP-A-5-341441). As a method for adding these dyes, any method such as a solution, an emulsion, a solid fine particle dispersion, and a state in which the dye is mordanted with a polymer mordant may be used. The amount of these compounds used is determined by the desired absorption,
Generally, it is preferable to use the resin in a range of 1 μm or more and 1 g or less per 1 m ² .

In the present invention, the antihalation layer can be provided on the side farther from the light source than the photosensitive layer. The antihalation layer preferably has a maximum absorption in a desired wavelength range of 0.3 or more and 2 or less, more preferably an absorption of an exposure wavelength of 0.5 or more and 2 or less, and an absorption of 0.001 or more in a visible region after processing. It is preferably less than 0.5, more preferably 0.001 or more and 0.3
It is preferable that the layer has an optical density of less than.

When an antihalation dye is used in the present invention, the dye has a desired absorption in the wavelength range, has a sufficiently low absorption in the visible region after the treatment, and has a desirable absorbance spectrum shape of the antihalation layer. Any compound can be used as long as it is possible. For example, the following are disclosed, but the present invention is not limited thereto.
As a single dye, JP-A-59-56458, JP-A-2-216140
No. 7-13295, No. 7-11432, U.S. Patent 5,380,635
JP-A-2-68539, page 13, lower left column, line 1 to page 14, lower left column, line 9; JP-A-3-24539, page 14, lower left column, page 16, lower right column There are compounds, and as dyes that can be decolorized by treatment, JP-A-52-139136, JP-A-53-132334,
56-501480, 57-16060, 57-68831, 57-1
01835, 59-182436, JP-A-7-36145, 7-19
9409, JP-B-48-33692, JP-B50-16648, JP-B2-41
No. 734, U.S. Pat.Nos. 4,088,497, 4,283,487,
There are 548,896 and 5,187,049.

In the present invention, the emulsion layer or the protective layer of the emulsion layer is disclosed in US Pat. Nos. 3,253,921 and 2,274,782.
No. 2,527,583 and No. 2,956,879, and can be used in photographic elements containing light absorbing materials and filter dyes. Alternatively, dyes can be mordant as described in, for example, US Pat. No. 3,282,699. The amount of the filter dye used is preferably from 0.1 to 3 at the exposure wavelength, particularly preferably from 0.2 to 1.5.

A hardener may be used in each of the layers such as the photosensitive layer, the protective layer and the back layer of the present invention. Examples of hardeners include:
U.S. Pat. No. 4,281,060, JP-A-6-208193
For example, polyisocyanates described in US Pat. No. 4,791,042, epoxy compounds described in U.S. Pat. No. 4,791,042, vinyl sulfone compounds described in JP-A-62-89048, and the like are used.

In the present invention, a surfactant may be used for the purpose of improving coating properties and charging. As the surfactant, any surfactant such as nonionic, anionic, cationic, and fluorine can be used as appropriate. Specifically, fluorine polymer surfactants described in JP-A-62-170950, U.S. Pat. No. 5,382,504, and the like;
No. 44945, JP-A-63-188135, etc., fluorine surfactants described in U.S. Pat. No. 3,885,965, etc., polysiloxane acid surfactants described in U.S. Pat.
And polyalkylene oxides and anionic surfactants described in No. 1140 and the like.

The heat-developable photographic emulsion of the present invention can be coated on various supports. Typical supports include polyester films, primed polyester films, poly (ethylene terephthalate) films, polyethylene naphthalate films, cellulose nitrate films, cellulose ester films, poly (vinyl acetal) films, polycarbonate films and related or resinous Materials, as well as glass.
Preferably, the support is transparent.

The photothermographic material of the present invention may contain an antistatic or conductive layer such as a soluble salt (eg, chloride or nitrate), a vapor-deposited metal layer, as described in US Pat. Nos. 2,861,056 and 3,206,312. Or a layer containing an insoluble inorganic salt or the like as described in U.S. Pat. No. 3,428,451.

As a method for obtaining a color image using the photothermographic material of the present invention, there is a method described in JP-A-7-13295, page 10, left column, line 43 to page 11, left column, line 40. Examples of color dye image stabilizers include British Patent No. 1,326,889, U.S. Patent Nos. 3,432,300, 3,699,909, 3,574,627 and 357.
Nos. 3050, 3764337 and 4042
No. 394.

The photographic emulsion for thermal development in the present invention can be coated by various coating operations including dip coating, air knife coating, flow coating or extrusion coating using a hopper of the type described in US Pat. No. 2,681,294. If desired, U.S. Pat. No. 2,761,791 and British Patent No. 83
Two or more layers can be coated simultaneously by the method described in US Pat.

An additional layer in the photothermographic material of the present invention,
For example, it can include a dye-receiving layer for receiving a mobile dye image, an opacifying layer if reflective printing is desired, a protective topcoat layer, and a primer layer known in the photothermographic art. The light-sensitive material of the present invention is the light-sensitive material 1
It is preferable that an image can be formed on only one sheet, and it is preferable that a functional layer such as an image receiving layer necessary for image formation does not become another member.

Although the light-sensitive material of the present invention may be developed by any method, it is usually developed by raising the temperature of the light-sensitive material exposed imagewise. A preferred development temperature is 80
To 250 ° C, more preferably 100 to 140 ° C
It is. The development time is preferably 1 to 180 seconds, and is preferably 1 to 180 seconds.
0 to 90 seconds is more preferred.

The photosensitive 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, gas laser, YA
G lasers, dye lasers, semiconductor lasers and the like are preferred. Also, a second harmonic generation element such as a semiconductor laser can be used.

The light-sensitive material of the present invention has a low haze at the time of exposure and tends to cause interference fringes. As a technique for preventing the occurrence of interference fringes, there is a technique disclosed in Japanese Patent Application Laid-Open No. Hei 5-113548 for obliquely entering a laser beam into a photosensitive material, or a multimode laser disclosed in WO95 / 31754. Methods of using are known, and it is preferable to use these techniques.

For exposing the photosensitive material of the present invention, SPIE vo
l.169 Laser Printing Pages 116-128 (197
9), JP-A-4-51043, WO95 / 31754
It is preferable to expose the laser beams so as to overlap each other so as to make the scanning lines invisible as disclosed in US Pat.

[0067]

【Example】

Example 1 (Preparation of silver halide grains A) 22 g of phthalated gelatin and 30 mg of potassium bromide were dissolved in 700 ml of water, and the mixture was dissolved at a temperature of 40 ° C.
After adjusting the pH to 5.0, 159m of an aqueous solution containing 18.6g of silver nitrate
An aqueous solution containing l, potassium bromide and potassium iodide in a molar ratio of 92: 8 was added over 10 minutes by a controlled double jet method while maintaining pAg 7.7. Then 55.4g of silver nitrate
476 ml of an aqueous solution containing
An aqueous solution containing 8 μmol / liter and potassium bromide at 1 mol / liter was added over 30 minutes by a controlled double jet method while maintaining the pAg at 7.7. After that, the pH was lowered to perform coagulation sedimentation and desalting treatment, and phenoxyethanol was added to 0.1%.
1 g was added to adjust the pH to 5.9 and pAg8.0. Silver iodide content core 8 mol%, average 2 mol%, grain size 0.07 μm,
Cubic particles having a variation coefficient of projected area diameter of 8% and a (100) plane ratio of 86%.

The temperature was adjusted with respect to the obtained silver halide grains.
The temperature was raised to 60 ° C and 85 moles of sodium thiosulfate per mole of silver.
μmol and 2, 3, 4, 5, 6-pentafluorophenyldiphenylphosphine selenide in 11 μmol, 2 μmol of tellurium compound 1, 3.3 μmol of chloroauric acid, thiocyanic acid
230 μmol was added and the mixture was aged for 120 minutes. Then the temperature
5 × 10 ^-4 mol of sensitizing dye A was changed to 50 ° C. per mol of silver halide were added with a sensitizing dye B 2 × to 10 ^-4 mol stirring. Further, potassium iodide is added to silver halide
3.5 mol% was added, the mixture was stirred for 30 minutes, and rapidly cooled to 30 ° C. to complete the preparation of silver halide grains A.

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[0070]

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(Preparation of Silver Crystalline Dispersion of Organic Acid) Behenic Acid
40 g, 7.3 g of stearic acid and 500 ml of water were stirred at a temperature of 90 ° C. for 15 minutes, 187 ml of 1N NaOH was added over 15 minutes, and 61 ml of a 1N aqueous nitric acid solution was added, followed by cooling to 50 ° C. Next, 124 ml of a 1N silver nitrate aqueous solution was added over 2 minutes, and the mixture was stirred as it was for 30 minutes. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate reached 30 μS / cm. The solid thus obtained was treated as a wet cake without drying, and 12 g of polyvinyl alcohol and 150 ml of water were added to a wet cake equivalent to 34.8 g of dry solid, and mixed well to form a slurry. Prepare 840 g of zirconia beads having an average diameter of 0.5 mm, put them in a vessel together with the slurry, and use a dispersing machine (1/4 G sand grinder mill:
Dispersion for 5 hours using an IMEX Co., Ltd., and preparation of a microcrystal dispersion of silver salt of organic acid, which is needle-shaped particles having an average minor axis of 0.04 μm, an average major axis of 0.8 μm, and a projected area variation coefficient of 30% by observation with an electron microscope. Finished.

(Preparation of Material Solid Fine Particle Dispersion) Tetrachlorophthalic acid, 4-methylphthalic acid, 1,1-bis (2
-Hydroxy-3,5-dimethylphenyl) -3,5,
Solid fine particle dispersions were prepared for 5-trimethylhexane, phthalazine, and tribromomethylphenylsulfone. 0.81 g of hydroxypropylmethylcellulose and 94.2 cc of water were added to tetrachlorophthalic acid, stirred well, and left as a slurry for 10 hours. After that, the average diameter is 0.
Prepare 100 cc of 5 mm zirconia beads, put them in a vessel together with the slurry, and disperse them for 5 hours with the same dispersing machine used to prepare the silver salt of organic acid microcrystals to obtain solid fine particles of tetrachlorophthalic acid. The dispersion had an average particle diameter of 70% by weight of 1.0 μm or less. For the other materials, the amount of the dispersant used and the dispersion time were changed to obtain the desired average particle size, and solid fine particle dispersions were obtained for each material.

(Preparation of Emulsion Layer Coating Solution) With respect to the previously prepared organic silver microcrystal dispersion (corresponding to 1 mol of silver), silver halide grains A were prepared by adding 10 mol% of silver halide / corresponding to organic acid silver. Was added to obtain an emulsion coating solution. Luckstar 3307B (SBR latex, manufactured by Dainippon Ink and Chemicals, Inc.) 430 g Tetrachlorophthalic acid 5 g 1,1-bis (2 = hydroxy-3,5-dimethylphenyl) -3,5,5-to Limethylhexane 98 g Phthalazine 9.2 g Tribromomethylphenylsulfone 12 g 4-Methylphthalic acid 7 g The equilibrium water content of Luckstar 3307B at 25 ° C. and 60% RH was 0.6 wt%.

(Preparation of Coating Solution for Emulsion Surface Protective Layer) For 10 g of inert gelatin, 0.26 g of surfactant A was added.
B, 0.09 g, matting agent (sphericity, particle size, amount added
As described above), 0.3 g of 1,2- (bisvinylsulfonylacetamido) ethane and 64 g of water were added to form a surface protective layer.

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(Preparation of Coloring Agent Dispersion) 35 g of ethyl acetate
, 2.5 g of the following compounds 1 and 2, respectively.
5 g was added and stirred to dissolve. 50 g of a 10% by weight solution of polyvinyl alcohol dissolved in advance was added to the solution, and the mixture was stirred with a homogenizer for 5 minutes. Thereafter, the ethyl acetate was volatilized by removing the solvent, and finally diluted with water to prepare a color former dispersion.

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(Preparation of Back Surface Coating Solution) To 30 g of polyvinyl alcohol, the color former dispersion 50 previously prepared was added.
g, the following compound 20 g, water 250 g, matting agent (type,
(The amount of addition is the same as that of the surface protective layer).

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(Preparation of Emulsion Layer Coating Sample) The emulsion layer coating solution prepared as described above was tinted with a blue dye.
1.9 g of silver on a μm polyethylene terephthalate support
/ M ^2, and then a coating liquid for an emulsion surface protective layer was applied in the form of an emulsion coating layer so that the coating amount of gelatin was 1.8 g / m ² . After drying, a coating solution for the back side was coated on the side opposite to the emulsion layer so as to have an optical density of 660 nm of 0.7.

The material thus obtained was placed at 25 ° C.
After storage at 7% RH for 7 days, the raw, developed and processed samples were evaluated for feel, haze, and Beck seconds when the surface was touched with bare hands.

The feel when the sample surface was touched with bare hands was classified into the following three ranks. A: No roughness when touched with bare hands. B: Slight roughness when touched with bare hands. C: There is a feeling of roughness when touched with bare hands. The ranks A and B are acceptable levels as products.

The development was carried out by pressing the surface on which the photosensitive layer was applied to a roller at 120 ° C. for 25 seconds. When the samples were separately exposed and developed and evaluated for photographic properties, all were good and there was no difference between the samples. Table 1 shows the results.

[0084]

[Table 1]

As can be seen from the above table, the photothermographic material of the present invention has no rough feeling even when touched with bare hands, and the effect of the matting agent does not decrease even after the heat development processing.

Claims (5)

[Claims] 1. A photothermographic material comprising at least one layer containing a spherical silica matting agent on at least one surface of a support. 2. The method according to claim 1, wherein at least one surface of the support has at least one photosensitive layer containing photosensitive silver halide and further contains an organic silver salt and a reducing agent for the silver salt. The photothermographic material according to claim 1. 3. The photothermographic material according to claim 1, wherein the photosensitive layer satisfies the following conditions. a. The binder contains 50 wt% or more of a material having an equilibrium water content of 2 wt% or less at 25 ° C. and 60% RH. b. A coating solution in which the above binder is dispersed in a solvent containing 30% by weight or more of water is applied and dried to form a coating solution. 4. An average particle diameter of the matting agent is 0.5 μm.
4. The photothermographic material according to claim 1, wherein the thickness is from 10 to 10 [mu] m. 5. The photothermographic material according to claim 2, further comprising at least one layer containing a spherical silica matting agent on both sides of the support.