JPH1048775A - Heat developing photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an irregular developing state and to improve handling property and travelling property of a heat developing photosensitive material having a layer containing photosensitive silver halide particles on one surface of a supporting body, by specifying the coefft. of kinetic friction between the surface having the photosensitive layer and the other surface. SOLUTION: In the heat developing photosensitive material having a layer containing photosensitive silver halide particles on one surface of a supporting body, the coefft. of kinetic friction between the surface having the photosensitive layer and the other surface is controlled to 0.01 to 0.25, preferably 0.1 to 0.25. The coefft. of static friction between the surface having the photosensitive layer and the other surface is preferably controlled to 1.5 to 5 times the coefft. of kinetic friction. To control the frictional coefft., a matting agent, surfactant or oil can be used. As for an org. compd. used as a matting agent, a water- dispersible vinyl polymer such as polymethylacrylate and poly- methylmethacrylate, or cellulose deriv. such as methylcellulose can be used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photothermographic material (hereinafter sometimes referred to as a photothermographic material).

[0002]

2. Description of the Related Art In recent years, there has been a strong demand in the medical field to reduce the amount of waste liquid from the viewpoint of environmental protection and space saving. Thus, a photosensitive heat for medical diagnostics and photographic technology can be efficiently exposed by a laser imagesetter or a laser imager, and can form a sharp black image having high resolution and sharpness. There is a need for technology for developed photographic materials. These photothermographic materials can eliminate the use of solution processing chemicals and provide a simpler and more environmentally friendly thermal development system to customers.

On the other hand, semiconductor laser technology, which has made rapid progress in recent years, has made it possible to reduce the size of medical image output devices. Naturally, the technology of infrared-sensitive photothermographic silver halide photographic material that can use a semiconductor laser as a light source was also developed.
No. 387, JP-A-5-341432, JP-A-6-94781, JP-A
No. 6,301,141 is disclosed, and as antihalation techniques, JP-A-7-13295 and US Pat. No. 5,380,635 are disclosed. In the case of a photosensitive material premised on infrared exposure, the visible absorption of a sensitizing dye or an antihalation dye can be significantly reduced, and a photosensitive material having substantially no color can be easily produced. By combining such a heat development technique and an infrared exposure technique, a photographic material free of any liquid can be produced.

On the other hand, since the heat-developable photosensitive material is developed at a high temperature of 100 ° C. or more, unevenness in development occurs due to the gas generated from the heat-developable photosensitive material accumulating on the surface of the photosensitive material during thermal development. In order to remove such gas, it is considered effective to make undulations on the surface of the photosensitive material, but if the undulation is made, it becomes slippery and easy to collapse with the photosensitive material, making it difficult to handle, and causing poor transport. Become. Such handling property is particularly deteriorated in a so-called sheet-like photosensitive material.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photothermographic material which is free from development unevenness and has excellent handleability and transportability.

[0006]

This object has been achieved by the following means. (1) In a photothermographic material having a layer containing photosensitive silver halide grains on one side of a support, the coefficient of kinetic friction between the surface having the photosensitive layer and the other surface is 0.01 or more and 0.25 or less. A photothermographic material comprising:

(2) The photothermographic material according to (1), wherein the coefficient of static friction between the surface having the photosensitive layer and the other surface is 1.5 to 5 times the dynamic friction coefficient.

(3) The photothermographic material according to (1) or (2), wherein the coefficient of dynamic friction is 0.1 or more and 0.25 or more.

(4) The photothermographic material according to (1), (2) or (3), wherein the photothermographic material is in the form of a sheet.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The photothermographic material of the present invention has a photosensitive layer containing photosensitive silver halide grains on one side and a so-called backing layer on the other side. Here, the coefficient of dynamic friction between the surface having the photosensitive layer and the other surface is 0.01 or more and 0.25 or more.
The value is preferably 0.1 or more and 0.25 or less. The coefficient of dynamic friction of the present invention is such that the surface having the photosensitive layer and the other surface have a constant weight.
It can be calculated from the required force (b) when moving in contact at (a) and moving at a constant speed (dynamic friction coefficient = b / a). In the present invention, to adjust the coefficient of friction, a matting agent, a surfactant, an oil, and the like can be used.

The matting agent in the present invention is generally fine particles of an organic or inorganic compound insoluble in water. Any matting agent can be used, for example, US Pat.
9,213, 2,701,245, 2,322,037, 3,262,
No. 782, No. 3,539,344, No. 3,767,448, etc., the organic matting agent described in each specification, No. 1,260,772, No. 2,192,241
Nos. 3,257,206, 3,370,951, 3,523,022
No. 3,769,020, etc., well-known in the art such as an inorganic matting agent described in each specification can be used.
For example, specifically, examples of organic compounds that can be used as a matting agent include, as examples of water-dispersible vinyl polymers, polymethyl acrylate, polymethyl methacrylate, polyacrylonitrile, acrylonitrile-α-methylstyrene copolymer, and polystyrene. , Styrene-divinylbenzene copolymer, polyvinyl acetate, polyethylene carbonate, polytetrafluoroethylene, etc.
Examples of cellulose derivatives include methylcellulose, cellulose acetate, cellulose acetate propionate and the like.Examples of starch derivatives include carboxy starch, carboxynitrophenyl starch, urea-formaldehyde-starch reactants, and gelatin and coacervate hardened with a known hardener. Hardened gelatin that has been hardened into microcapsule hollow particles can be preferably used. Examples of inorganic compounds include silicon dioxide, titanium dioxide, magnesium dioxide, aluminum oxide, barium sulfate, calcium carbonate, silver chloride desensitized by known methods, and silver bromide,
Glass, diatomaceous earth and the like can be preferably used.

The above matting agents can be used by mixing different kinds of substances as required. The shape of the matting agent of the present invention is not particularly limited, and any shape such as a perfect sphere or an irregular shape can be used as necessary. Also,
The size of the matting agent of the present invention is not particularly limited, and those having an arbitrary particle size can be used. In the practice of the present invention, particles having a particle size of 0.1 μm to 30 μm are preferably used, and those having a particle size of 0.3 μm to 15 μm are more preferably used. The particle size distribution of the matting agent can be varied from wide to so-called monodispersed as required. On the other hand, since the matting agent greatly affects the haze and surface gloss of the light-sensitive material, the particle size, shape, and particle size distribution can be changed as necessary during the preparation of the matting agent or by mixing a plurality of matting agents. preferable.

The preferred amount of the matting agent of the present invention varies depending on the intended use of the target photothermographic material, and cannot be specified unconditionally, but is preferably in the range of 5 to 200 mg / m ² , and more preferably 10 to 200 mg / m ^2. in the range of 150 mg / m ^2. In the present invention, the layer to which the matting agent is added is not particularly limited, but it is preferably contained in a layer functioning as the outermost surface layer or the outermost surface layer of the photothermographic material, or a layer close to the outer surface. It is preferably contained in a layer acting as a protective layer. In the present invention, the matting agent can be used not only for adjusting the coefficient of friction, but also for improving the surface gloss, the transportability, and preventing sticking.

In the present invention, the matting degree of the backing layer is preferably such that the Beck smoothness is 250 seconds or less and 10 seconds or more,
More preferably, the time is 180 seconds or less and 50 seconds or more. The matte degree of the emulsion surface of the present invention may be any value as long as stardust failure does not occur, but the Beck smoothness is preferably from 300 seconds to 10,000 seconds, particularly preferably from 500 seconds to 10,000 seconds.

As examples of the surfactant of the present invention, any of nonionic, anionic, cationic and fluorine-based surfactants can be appropriately used. Specifically, JP-A-62-170950
No. 5,380,644 and the like, fluorine-containing polymer surfactants described in JP-A-60-244945, JP-A-63-188135 and the like, U.S. Pat.
No. JP-A-6-30
Examples thereof include polyalkylene oxide and anionic surfactant described in No. 1140 and the like. In the present invention, the surfactant may be used not only for adjusting the coefficient of kinetic friction but also for improving coating properties and charging.

The oil of the present invention is preferably a silicone oil such as silicone oil or silicone grease, or a hydrocarbon oil such as wax.

The photothermographic material of the present invention has a photosensitive layer containing photosensitive silver halide grains on one side and a so-called backing layer on the other side. Here, the static friction coefficient between the surface having the photosensitive layer and the other surface is the dynamic friction coefficient.
It is preferably 1.5 times or more and 5 times or less, and the static friction coefficient value is preferably 0.25 or more and 0.5 or less. The coefficient of static friction of the present invention can be determined from the gradient at the moment when the weight starts to move by contacting the other surface with the weight on the surface having the photosensitive layer and tilting the whole.

The photothermographic emulsion of the present invention comprises one or more layers on a support. At least one layer must contain silver halide, and an organic silver salt,
It is preferred to include developers and binders and optional additional materials such as toning agents, coating aids and other auxiliaries. The two-layer configuration includes an organic silver salt and a silver halide in a first emulsion layer (usually a layer adjacent to the base),
Some other components must be included in the second layer or both layers. However, a two-layer construction comprising a single emulsion layer containing all components and a protective topcoat is also contemplated. The construction of a multicolor light-sensitive photothermographic material may include a combination of these two layers for each color, and US Pat.
All components may be contained in a single layer as described in 4,708,928. In the case of a multi-dye, multi-color photosensitive heat-developable photographic material, each emulsion layer is generally comprised of US Pat.
As described in No. 1, the use of a functional or non-functional barrier layer between each photosensitive layer keeps them distinct from each other.

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

An example of spectral sensitization to red light is He-Ne
For the laser light source, the I-beam described in JP-A-54-18726 is used.
Compounds represented by I-1 to I-38; I-1 described in JP-A-6-75322
To I-35 and the compounds described in JP-A-7-287338.
Compounds of -1 to I-34, for LED light source
Dyes 1 to 20 described in JP-A-9818, compounds of I-1 to I-37 described in JP-A-62-284343, compounds of I-1 to I-34 described in JP-A-7-287338, and the like. Advantageously selected.

Specifically, the silver halide grains are spectrally sensitized in a wavelength range of 750 to 1400 nm. Specifically, the photosensitive silver halide is converted into cyanine, merocyanine, styryl, hemicyanine, oxonol, hemioxonol and Various known dyes, including xanthene dyes, can be spectrally sensitized favorably. Useful cyanine dyes are, for example, cyanine dyes having basic nuclei such as thiazoline nuclei, oxazoline nuclei, pyrroline nuclei, pyridine nuclei, oxazole nuclei, thiazole nuclei, selenazole nuclei and imidazole nuclei. Preferred useful merocyanine dyes include, in addition to the above basic nuclei, acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus. Including. Among the above cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective. For example, U.S. Pat.
No. 3,719,495; No. 3,877,943; British Patent No.
Nos. 1,466,201, 1,469,117, 1,422,057,
JP-B-3-10391, JP-B6-52387, JP-A-5-341432
And known dyes described in JP-A-6-94781 and JP-A-6-301141. A particularly preferred structure of the dye is a cyanine dye having a thioether bond, and examples thereof include JP-A-62-58239 and 3-1386.
38,3-138642,4-255840,5-72659,5-72661,6-2224
91, 2-230506, 6-258757, 6-317868, 6-324425, Tokiohei
7-500926.

These sensitizing dyes may be used alone,
Two or more kinds may be used in combination. Combinations of sensitizing dyes are often used, especially for supersensitization. Along with the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization and substances exhibiting supersensitization are Re.
search Disclosure Volume 176 Volume 17643 (Issued December 1978) No. 23
It is described in section J of page IV, or JP-B-49-25500 and JP-B-43-4933, JP-A-59-19032 and JP-A-59-192242.

Two or more sensitizing dyes may be used in combination in the present invention. The sensitizing dyes can be added to the silver halide emulsion by dispersing them directly in the emulsion or by using water, methanol, ethanol, propanol, acetone, methylcellosolve, 2,2,3,3 -Tetrafluoropropanol, 2,2,2-trifluoroethanol, 3-
A solvent such as methoxy-1-propanol, 3-methoxy-1-butanol, 1-methoxy-2-propanol, N, N-dimethylformamide or the like may be dissolved in a single or mixed solvent and added to the emulsion.

As disclosed in US Pat. No. 3,469,987, a dye is dissolved in a volatile organic solvent, and the solution is dispersed in water or a hydrophilic colloid. No. 44-23389, same method
As disclosed in 44-27555, 57-22091, etc.,
A method in which a dye is dissolved in an acid and the solution is added to the emulsion or added as an aqueous solution in the presence of an acid or base to the emulsion, as disclosed in U.S. Patent Nos. 3,822,135 and 4,006,025. As described in JP-A-53-102733 and JP-A-58-105141, a method of adding an aqueous solution or a colloidal dispersion in the coexistence of a surfactant to an emulsion is used. A method in which a dye is directly dispersed in an emulsion, and the dispersion is added to an emulsion.
As disclosed in JP-A No. 24, a method of dissolving a dye using a compound that causes a red shift and adding the solution to an emulsion can also be used. Also, ultrasonic waves can be used for the solution.

The sensitizing dye used in the present invention may be added to the silver halide emulsion of the present invention at any stage of the emulsion preparation which has been found to be useful. For example, U.S. Pat.Nos. 2,735,766 and 3,628,96
No. 4, No. 4,183,756, No. 4,225,666, JP-A-58
As disclosed in the specifications of JP-A-184142 and JP-A-60-196749, chemical ripening is carried out during the step before silver halide grain formation or / and desalination, during the silver removal step and / or after desalination. Before the start of the process, as disclosed in the specification of JP-A-58-113920, etc., immediately before or during the chemical ripening, during the process, after the chemical ripening, until the application of the emulsion is applied. At any time before, it may be added in the process. U.S. Pat. No. 4,225,666;
As disclosed in the specification of No. 629, etc., the same compound may be used alone or in combination with a compound having a heterogeneous structure, for example, during the particle formation step and during the chemical ripening step or after the completion of the chemical ripening, The compound may be added in portions such as before aging or during the process and after completion, or may be added by changing the kind of compound to be added and the combination of compounds.

The photothermographic material according to the present invention comprises:
It is preferable that the support is a so-called single-sided light-sensitive material having a photosensitive layer containing at least one silver halide emulsion on one side and a backing layer on the other side.

The method of forming the photosensitive silver halide in the present invention is well known in the art, and uses, for example, the methods described in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. be able to. Specific methods that can be used in the present invention include a method of converting a part of the silver of the organic silver salt to a photosensitive silver halide by adding a halogen-containing compound to the prepared organic silver salt, gelatin. Alternatively, a method 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 particle size of the photosensitive silver halide is preferably small for the purpose of suppressing the white turbidity after image formation to be low.
It is preferably 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.
It is preferable that the proportion occupied by 100 faces is high. 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 is determined by T. Tani; J. Imaging Sci., 29, which utilizes the dependence of the adsorption of the sensitizing dye on the (111) plane and the (100) plane.
165 (1985).
The halogen composition of the photosensitive silver halide is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide, and silver iodide. In the present invention, silver bromide or silver iodobromide can be preferably used. Particularly preferred is silver iodobromide, and the silver iodide content is preferably from 0.1 mol% to 40 mol%,
The content is more preferably from 0.1 mol% to 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. The structure is preferably a two- to five-fold structure, more preferably a two to four-fold structure.
Heavy core / shell particles 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 or iron. These metal complexes are 1
They may be used alone or in combination of two or more of the same metal and different metal complexes. The preferred content is 1n per mole of silver.
Mol to 10 mmol is preferred, and 10 nmol to 100 mol.
A μmol range is more preferred. 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 or 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, diacyltellurides, 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, more preferably 0.03 mol or less, per 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.

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 (with 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 can preferably comprise about 5 to 30% 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 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 crystal having a short axis and a long axis is preferable. As is well known in photosensitive silver halide light-sensitive materials, the inverse relationship between the size of silver salt crystal grains and their covering power also holds in the photothermographic material of the present invention, that is, the photothermographic material is used. When the size of the organic silver salt particles as the image forming portion of the material is large, it means that the covering power is small and the image density is low. Therefore, it is necessary to reduce the size of the organic silver salt. In the present invention, the minor axis 0.01
μm or more and 0.20 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
It is more preferably at least μm and at most 4.0 μm. The particle size distribution of the organic silver salt is preferably monodispersed. Monodispersion is a percentage of the value obtained by dividing the standard deviation of the lengths of the minor axis and major axis by the minor axis and major axis, respectively, is preferably 100% or less, more preferably 80% or less, and still 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. As another method of measuring monodispersity, there is a method of calculating the standard deviation of the volume-weighted average diameter of an organic silver salt, and the percentage divided by the volume-weighted average diameter (coefficient of variation) is preferably 100% or less. ,
It is more preferably at most 80%, further preferably at most 50%. As a measuring method, for example, the organic silver salt dispersed in the liquid is irradiated with laser light, and the particle size (volume weight average diameter) obtained by obtaining an autocorrelation function for the time change of the fluctuation of the scattered light is obtained. Can be.

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.
a / m ^2.

The reducing agent for the organic silver salt may be any substance that 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 used in one of the image forming layers.
It should be present as ~ 10% by weight. When a reducing agent is added to a layer other than the emulsion layer in a multilayer structure,
A slightly higher percentage, about 2-15%, tends to be more desirable.

A wide range of reducing agents have been disclosed for photothermographic materials utilizing organic silver salts. For example, phenylamide oxime, 2-thienylamide oxime and p-
Amide oximes such as phenoxyphenylamide oxime; azines such as 4-hydroxy-3,5-dimethoxybenzaldehyde azine; fats such as a combination of 2,2-bis (hydroxymethyl) propionyl-β-phenylhydrazine and ascorbic acid Combinations of aromatic carboxylic acid aryl hydrazides with ascorbic acid; polyhydroxybenzene and hydroxylamine, reductone and / or
Or a combination of hydrazines (eg, hydroquinone and
Bis (ethoxyethyl) hydroxylamine, a combination of piperidinohexose reductone or formyl-4-methylphenylhydrazine); hydroxamic acids such as phenylhydroxamic acid, p-hydroxyphenylhydroxamic acid and β-alinine hydroxamic acid; A combination of azine and sulfonamidophenol (for example, phenothiazine and 2,6-dichloro-4-benzenesulfonamidophenol); α such as ethyl-α-cyano-2-methylphenylacetate, ethyl-α-cyanophenylacetate -Cyanophenylacetic acid derivatives; 2,2-dihydroxy-1,1-binaphthyl, 6,6-dibromo-2,2-dihydroxy
Bis-β-naphthol as exemplified by -1,1-binaphthyl and bis (2-hydroxy-1-naphthyl) methane;
Bis-β-naphthol and a 1,3-dihydroxybenzene derivative (eg, 2,4-dihydroxybenzophenone or 2,
5-pyrazolone, such as 3-methyl-1-phenyl-5-pyrazolone;
Reductones as exemplified by dimethylaminohexose reductone, anhydrodihydroaminohexose reductone and anhydrodihydropiperidone hexose reductone; 2,6-dichloro-4-benzenesulfonamidophenol and p-benzenesulfone Sulfonamidophenol reducing agents such as amidophenol; 2-phenylindan-1,3-dione; chromans such as 2,2-dimethyl-7-t-butyl-6-hydroxychroman; 2,6-dimethoxy-3, 1,4-dihydropyridines such as 5-dicarbethoxy-1,4-dihydropyridine; bisphenols (eg,
Bis (2-hydroxy-3-t-butyl-5-methylphenyl)
Methane, 2,2-bis (4-hydroxy-3-methylphenyl)
Propane, 4,4-ethylidene-bis (2-t-butyl-6-methylphenol), 1,1, -bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane and 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane and the like); ascorbic acid derivatives (for example, palmitic acid 1-
Ascorbyl, ascorbyl stearate, etc.); and aldehydes and ketones such as benzyl and biacetyl; 3-pyrazolidone and certain indane-1,3-
Dione; chromanol (tocopherol and the like); Particularly preferred reducing agents are bisphenol and chromanol.

It may be advantageous to include, in addition to the aforementioned components, additives known as "toning agents" which enhance the image. For example, the toning agent material has a total silver holding component of 0.1 to
It may be present in an amount of 10% by weight. Toning agents are described in U.S. Pat.
As shown in Nos. 80,254, 3,847,612 and 4,123,282, they are well known in the photographic art.

Examples of toning agents include phthalimide and N-hydroxyphthalimide; succinimide, pyrazoline-5-
Quinazolinone, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and
Cyclic imides such as 2,4-thiazolidinedione; naphthalimides (eg, N-hydroxy-1,8-naphthalimide); cobalt complexes (eg, cobalt hexamine trifluoroacetate); 3-mercapto-1,2,4 -Triazole, 2,4-dimercaptopyrimidine, 3-mercapto-4,5
-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-
Dicarboxyimide); and blocked pyrazoles, isothiuronium derivatives, and certain photobleaching agents (eg, N, N-hexamethylenebis (1-carbamoyl-
3,5-dimethylpyrazole), 1,8- (3,6-diazaoctane) bis (isothiuronium trifluoroacetate)
And 2-tribromomethylsulfonyl)-(benzothiazole)); and 3-ethyl-5 [(3-ethyl-2-benzothiazolinylidene) -1-methylethylidene] -2-thio-2,4-
Oxazolidinedione; phthalazinone, phthalazinone derivatives or metal salts, or 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone and 2,3-dihydro-1,4-phthalazinedione A combination of phthalazinone and a phthalic acid derivative (such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride);
Phthalazine derivatives or metal salts, or derivatives such as 4- (1-naphthyl) phthalazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine; phthalazine and phthalic acid derivatives (eg, phthalic acid) acid,
Quinazolinedione, such as 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride;
Benzoxazine or naphthoxazine derivatives; rhodium complexes that function not only as color tone regulators but also in-situ as sources of halide ions for silver halide formation, such as ammonium hexachlororhodate (III), rhodium bromide, rhodium nitrate And potassium hexachlororhodate (III); inorganic peroxides and persulfates such as ammonium disulfide and hydrogen peroxide; 1,3-benzoxazine-2,4-dione, 8-methyl
-1,3-benzoxazine-2,4-dione and 6-nitro-
Benzoxazine-2,4-diones such as 1,3-benzoxazine-2,4-dione; pyrimidines and asymmetric-triazines (eg, 2,4-dihydroxypyrimidine, 2-hydroxy-4-aminopyrimidine and the like), Azauracil and tetraazapentalene derivatives (for example, 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).

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained in order to suppress or accelerate development to control development, to improve spectral sensitization efficiency, to improve storage stability before and after development, and the like. be able to.

When a mercapto compound is used in the present invention, it may be of any structure, but may be any of Ar-SM, Ar-SSA
Those represented by r are preferred. Wherein M is a hydrogen atom or an alkali metal atom, and Ar is an aromatic or fused aromatic ring having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably, the heteroaromatic ring is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, pyridazine , Pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring can be, for example, halogen (eg, Br and Cl), hydroxy, amino, carboxy, alkyl (eg, 1
From a substituent group consisting of at least one carbon atom, preferably having 1 to 4 carbon atoms) and alkoxy (for example, having at least one carbon atom, preferably having 1 to 4 carbon atoms). It may have one to be selected. As mercapto-substituted heteroaromatic compounds, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-
Methylbenzimidazole, 6-ethoxy-2-mercaptobenzothiazole, 2,2'-dithiobis- (benzothiazole, 3-mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2- Mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2-mercaptoquinoline, 8-mercaptopurine, 2-mercapto
-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,5,6-tetrachloro-4-pyridinethiol, 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate , 2-Amino-5-mercapto-1,3,4-thiadiazole, 3-Amino-5-mercapto-1,2,4-triazole, 4-Hydrocyr-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6 -Diamino-2-mercaptopyrimidine, 2-mercapto-4-methylpyrimidine hydrochloride, 3-mercapto-5-phenyl-1,2,4-triazole, 2-mercapto-4-phenyloxazole, etc. The invention is not limited to these.

The amount of the mercapto compound added is preferably in the range of 0.001 to 1.0 mol per mol of silver in the emulsion layer, more preferably 0.01 to 1.0 mol per mol of silver.
The amount is 0.3 mol.

The light-sensitive material of the present invention can be provided with a surface protective layer for the purpose of preventing adhesion of an image forming layer.
Any anti-adhesion material may be used as the surface protective layer. Examples of anti-adhesion materials include waxes, silica particles, styrene-containing elastomeric block copolymers (eg, styrene-butadiene-styrene, styrene
-Isoprene-styrene), cellulose acetate, cellulose acetate butyrate, cellulose propionate and mixtures thereof.

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.

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, butylethyl 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. The effective range can be appropriately determined by those skilled in the art. As a guideline for at least retaining the organic silver salt, the ratio of the binder to the organic silver salt is 15:
The range of 1-1: 2, particularly 8: 1 to 1: 1 is preferred.

The photothermographic material of the present invention comprises:
A so-called one-sided light-sensitive material having a photosensitive layer containing at least one silver halide emulsion on one side of a support and a backing layer on the other side is preferred.

In the present invention, suitable binders for the backing layer are transparent or translucent, generally colorless, and natural polymer synthetic resins, polymers and copolymers, and other film-forming media such as: gelatin, gum arabic, poly (vinyl) Alcohol), hydroxyethylcellulose, cellulose acetate, cellulose acetate butyrate, poly (vinylpyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), copoly (Styrene-maleic anhydride), copoly (styrene)
-Acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethanes), phenoxy resins, poly ( Vinylidene chloride), poly (epoxide) s,
Poly (carbonate) s, poly (vinyl acetate),
There are cellulose esters and poly (amides). The binder may be coated from water or an organic solvent or an emulsion.

In the present invention, the backing layer preferably has a maximum absorption in a desired wavelength range of 0.3 or more and 2 or less, more preferably an IR absorption of 0.5 or more and 2 or less, and an absorption in the visible region of 0.001 or less. It is preferably at least 0.5 and more preferably at least 0.001.
Preferably, the antihalation layer has an optical density of less than 3.

When an antihalation dye is used in the present invention, the dye has a desired absorption in a desired wavelength range, has a sufficiently low absorption in a visible region, and can obtain a preferable absorbance spectrum shape of the backing layer. Any compound may be used. For example, JP-A-7-13295, U.S. Pat.
No. 0,635, 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 to page 16, lower right Although the compounds described in the column are mentioned, the present invention is not limited thereto.

US Pat. Nos. 4,460,681 and 4,374,
The backside resistive heating layer (backside re
A sistive heating layer) can also be used in a photothermographic image system.

The photothermographic material of the present invention may contain benzoic acids for the purpose of increasing the sensitivity and preventing fog. The benzoic acids of the present invention may be any benzoic acid derivative, but examples of preferred structures include those described in U.S. Pat.
No. 9, No. 4, 152, 160, Japanese Patent Application No. 8-151242, No. 8-151241
And the compounds described in JP-A-8-98051. The benzoic acids of the present invention may be added to any part of the light-sensitive material. However, the added layer is preferably added to a layer having a light-sensitive layer, more preferably to an organic silver salt-containing layer. . The benzoic acid of the present invention may be added at any time during the preparation of the coating solution, and when it is added to the organic silver salt-containing layer, it may be added at any time from the preparation of the organic silver salt to the preparation of the coating solution. It is preferable after salt preparation and immediately before application. The benzoic acid of the present invention may be added by any method such as powder, solution, and fine particle dispersion. Further, it may be added as a solution mixed with other additives such as a sensitizing dye, a reducing agent and a color tone agent. The benzoic acid of the present invention may be added in any amount, but preferably 1 μmol or more and 2 mol or less, more preferably 1 mmol or more per 1 mol of silver.
0.5 mol or less is more preferred.

The silver halide emulsion according to the present invention or /
And the organic silver salts can be further protected against the formation of additional fog by antifoggants, stabilizers and stabilizer precursors, and can be stabilized against reduced sensitivity during stock storage. Suitable antifoggants, stabilizers and stabilizer precursors that can be used alone or in combination are the thiazonium salts described in U.S. Pat.Nos. 2,131,038 and 2,694,716, U.S. Pat.Nos. 2,886,437 and 2,444,605. Azaindene, U.S. Pat.
No. 728,663, mercury salt described in U.S. Pat.No. 3,287,135, sulfocatechol described in U.S. Pat.No. 3,235,652, oxime described in British Patent No. 623,448, nitrone, nitroindazole, U.S. Pat.
No. 405, polyvalent metal salts, U.S. Pat.No. 3,220,839, thyuronium salts, and U.S. Pat.
Palladium, platinum and gold salts described in U.S. Patent Nos. 4,108,665 and 4,442,20
Halogen-substituted organic compounds described in No. 2, U.S. Pat.
Nos. 8,557 and 4,137,079, 4,138,365 and 4,459,350, and the phosphorus compounds described in U.S. Pat. No. 4,411,985.

The antifoggant preferably used in the present invention is an organic halide, for example, as described in JP-A-50-119624.
No. 50-120328, No. 51-121332, No. 54-58022,
56-70543, 56-99335, 59-90842, 61-129
No. 642, No. 62-129845, JP-A-6-208191, No. 7-5621
Nos. 7-2781, 8-15809, U.S. Pat.No. 5,340,712
No. 5,369,000 and 5,464,737.

In the photosensitive layer according to the present invention, a polyhydric alcohol (for example, US Pat.
Glycerin and diols of the type described in U.S. Pat. No. 960,404), fatty acids or esters described in U.S. Pat. Nos. 2,588,765 and 3,121,060, and silicone resins described in British Patent No. 955,061.

A hardener may be used for each layer such as the photosensitive layer, protective layer and back layer of the present invention. Examples of hardeners include:
U.S. Pat.No. 4,281,060, polyisocyanates described in JP-A-6-208193, etc., epoxy compounds described in U.S. Pat.
Vinyl sulfone compounds described in No. 48 and the like are used.

In the present invention, a hydrazine derivative may be used. When a hydrazine derivative is used in the present invention, the compound of the general formula (I) described in Japanese Patent Application No. 6-47961 is used. Specifically, compounds represented by I-1 to I-53 described in the same specification are used.

The following hydrazine derivatives are also preferably used. Compounds represented by (Chemical Formula 1) described in JP-B-6-77138, specifically, compounds described on pages 3 and 4 of the same publication. Compounds represented by the general formula (I) described in JP-B-6-93082, specifically, compounds 1 to 38 described on pages 8 to 18 of the same publication. General formula (4) described in JP-A-6-230497, general formula
Compounds represented by (5) and general formula (6), specifically, compounds 4-1 to 4-10, 28 described in pages 25 and 26 of the same publication.
Compounds 5-1 to 5-42 on pages 36 to 36, and compounds 6-1 to 6-7 on pages 39 and 40. Compounds represented by general formulas (1) and (2) described in JP-A-6-289520, specifically, compounds 1-1) described on pages 5 to 7 of the same publication
1-17) and 2-1). (Chemical formula 2) described in JP-A-6-313936
And compounds represented by (Chemical Formula 3).
Compounds described on page 19. A compound represented by (Chemical Formula 1) described in JP-A-6-313951, specifically, pages 3 to 5 of the same.
Compound described on page. General formula (I) described in JP-A-7-5610
And specifically, compounds I-1 to I-38 described on pages 5 to 10 of the publication. A compound represented by the general formula (II) described in JP-A-7-77783, specifically, pages 10 to 27 of the publication
Compounds II-1 to II-102 described on page. A compound represented by the general formula (H) and the general formula (Ha) described in JP-A-7-104426,
Specifically, compounds H-1 to H-4 described on pages 8 to 15 of the publication
Four. A compound characterized by having an anionic group or a nonionic group forming an intramolecular hydrogen bond with a hydrogen atom of hydrazine in the vicinity of a hydrazine group described in Japanese Patent Application No. 7-191007, particularly a compound represented by the general formula (A): Compounds represented by the general formula (B), the general formula (C), the general formula (D), the general formula (E), and the general formula (F), specifically, the compounds N-1 to N-1 described in the same publication N-30. A compound represented by the general formula (1) described in Japanese Patent Application No. 7-191007,
Specifically, compounds D-1 to D-55 described in the publication.

When a hydrazine nucleating agent is used in the present invention, a suitable water-miscible organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide , Dimethyl sulfoxide,
It can be used by dissolving it in methylcellosolve or the like.
Also, by an already well-known emulsification dispersion method, dissolution is performed 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 emulsified and dispersed. An object can be prepared and used. Alternatively, a powder of a hydrazine derivative can be dispersed in water by a ball mill, a colloid mill, or an ultrasonic wave by a method known as a solid dispersion method and used.

When a hydrazine-based nucleating agent is used in the present invention, it may be added to any of the silver halide emulsion layer or another hydrophilic colloid layer on the side of the silver halide emulsion layer with respect to the support. However, it is preferable to add to the silver halide emulsion layer or the hydrophilic colloid layer adjacent thereto. The addition amount of the nucleating agent of the present invention is preferably from 1 μm to 10 mmol, more preferably from 10 μm to 5 mmol, and most preferably from 20 μm to 5 mmol, per 1 mol of silver halide.

Although not required to practice the present invention,
It may be advantageous to add a mercury (II) salt as an antifoggant to the emulsion layer. Preferred mercury (II) salts for this purpose are
Mercury acetate and mercury bromide.

The photographic emulsion for heat development in 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 Including materials, as well as glass, paper, metal and the like. Flexible substrates, especially coated with partially acetylated or baryta and / or α-olefin polymers, especially polymers of C 2-10 α-olefins such as polyethylene, polypropylene, ethylene-butene copolymers A coated paper support is typically used. The support may be transparent or opaque, but is preferably transparent.

The light-sensitive material of the present invention comprises an antistatic or conductive layer, for example, a soluble salt (eg, chloride, nitrate, etc.), a vapor-deposited metal layer, and an ionizable 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 US Pat. No. 3,428,451.

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

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

In the heat-developable photographic material of the present invention, additional layers such as a dye-receiving layer for receiving a moving dye image, an opacifying layer if reflective printing is desired, a protective topcoat layer and photothermographic techniques It may include a known primer layer and the like. The light-sensitive material of the present invention is preferably capable of forming an image with only one light-sensitive material, and it is preferable that a functional layer required for image formation such as an image receiving layer does not become another light-sensitive material.

The light-sensitive material of the present invention may be developed by any method, but is usually developed by raising the temperature of the light-sensitive material exposed imagewise. The preferred development temperature is 80 to
The temperature is 250 ° C, more preferably 100 to 140 ° C.
The development time is preferably from 1 to 180 seconds, more preferably from 10 to 90 seconds. The light-sensitive material of the present invention may be exposed by any method, but a laser beam is preferred as an exposure light source. As laser light according to the present invention, gas laser,
YAG lasers, dye lasers, semiconductor lasers and the like are preferred. Further, a semiconductor laser and a second harmonic generation element can be used.

The light-sensitive material of the present invention may be packed in any form, but is usually cut into a rectangle having round corners, and then placed in a packaging material in a set of 50 to 1,000 sheets as a set. Materials are preferred. The packaging material of the photothermographic material according to the invention is preferably made of a material having an absorptance of 99% or more, particularly 99.9% or more and 100% or less of light to which the photothermographic material is exposed.

[0070]

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited to these. Example 1 << Preparation of silver halide grains >> 23 g of phthalated gelatin and 30 mg of potassium bromide were dissolved in 700 ml of water, and the solution was dissolved at a temperature of 35 ° C.
After adjusting the pH to 5.1, 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 the control double jet method while maintaining pAg 7.7. Then, 476 ml of an aqueous solution containing 55.4 g of silver nitrate and dipotassium hexachloroiridate were added to 11
While maintaining an aqueous solution pAg7.7 containing μmol / liter and potassium bromide at 1 mol / liter, it was added over 30 minutes by the control double jet method. Thereafter, the pH was lowered to perform coagulation sedimentation and desalting treatment, 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and pAg8.2, and silver iodobromide grains (iodine content core 8 mol%, average 2 mol%, Average size 0.06μm,
Cubic particles with a projected area variation coefficient of 8% and a (100) face ratio of 89%)
Was completed.

The silver halide grains thus obtained were heated to 60 ° C., and 90 μmol of sodium thiosulfate and 2,2
10 μmol of 3,4,5,6-pentafluorophenyldiphenylphosphine selenide, 12 μmol of tellurium compound 1, 4 μmol of chloroauric acid, and 280 μmol of thiocyanic acid were added thereto.
After ripening for 0 minutes, the mixture was rapidly cooled to 30 ° C. to obtain a silver halide emulsion.

<< Preparation of Organic Acid Silver Emulsion >> Stearic Acid 1.3
g, 0.5 g of arachidic acid, 8.5 g of behenic acid, 300 ml of distilled water
The mixture was mixed at 0 ° C for 15 minutes, 31.1 ml of a 1N-NaOH aqueous solution was added over 15 minutes with vigorous stirring, and then the temperature was lowered to 32 ° C. Next, 7 ml of a 1N-phosphoric acid aqueous solution was added, and 0.12 g of N-bromosuccinimide was added while stirring more vigorously, and then 2.5 mmol of silver halide grains prepared in advance as silver halide were added. In addition, 25 ml of 1N silver nitrate aqueous solution
Was added over 2 minutes, and stirring was continued for 90 minutes. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm. 37 g of a 1.2% by weight solution of polyvinyl acetate in butyl acetate was added to the solid content thus obtained, and the mixture was stirred. The stirring was stopped, the mixture was allowed to stand, the mixture was separated into an oil layer and an aqueous layer, and the aqueous layer was removed together with the contained salts to obtain an oil layer. Next, 20 g of a 2.5 wt% 2-butanone solution of polyvinyl butyral (Denka Butyral # 3000-K manufactured by Denki Kagaku Kogyo KK) was added to the oil layer.
Was added and stirred. In addition, pyridinium perbromide bromide 0.
After adding 11 mmol and 0.14 mmol of calcium bromide dihydrate together with 0.7 g of methanol, 40 g of 2-butanone and 7.8 g of polyvinyl butyral (BUTVAR ^TM B-76 manufactured by Monsanto Co.)
Was added and dispersed with a homogenizer to obtain an organic acid silver salt emulsion (acicular particles having an average minor axis of 0.04 μm, an average major axis of 1.4 μm, and a variation coefficient of 28%).

<< Preparation of Emulsion Layer Coating Solution >> Each of the chemicals was added to the above-obtained organic acid silver emulsion in the following amount per mol of silver. Sodium phenylthiosulfonate 9m at 28 ° C
g, 70 mg of Dye 1, 32 mg of Dye 2, 2.5 g of 2-mercapto-5-methylbenzimidazole, 4-chlorobenzophenone
23 g of -2-carboxylic acid, 580 g of 2-butanone, and 220 g of dimethylformamide were added with stirring and left for 3 hours. Then, 7.6 g of 5-tribromomethylsulfonyl-2-methylthiadiazole, 6 g of 2-tribromomethylsulfonylbenzothiazole, 4.8 g of 4,6-ditrichloromethyl-2-phenyltriazine, 2 g of disulfide compound 1 and 1,1 -Screw (2
-Hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane 150 g, Megafax F-176P (Fluorine surfactant manufactured by Dainippon Ink and Chemicals, Inc.) 1 g, 2-butanone
590 g and 10 g of methyl isobutyl ketone were added with stirring.

<< Emulsion Surface Protective Layer Coating Solution >> CAB171-15S (cellulose acetate butyrate manufactured by Eastman Chemical Co., Ltd.) 75 g, 4-g
5.9 g of methylphthalic acid, 1.5 of tetrachlorophthalic anhydride
g, 5.5 g of tetrachlorophthalic acid, 13 g of phthalazine, 0.3 g
Megafax F-176P, Sildex H31 (Dorkai Chemical Co., Ltd., spherical silica average size 3 μm) 1.5 g, sumidur N3500
(Polyisocyanate manufactured by Sumitomo Bayer Urethane Co., Ltd.)
-A solution prepared by dissolving in 3070 g of butanone and 30 g of ethyl acetate was prepared.

<< Back Surface Coating Solution >> Calcium Compound 1 was synthesized as follows. 0.08 mol of 3,5-di-tert-butylc
0.019 per liter of ethanol solution containing atechol
167 ml of an aqueous solution containing 0.1 mol of calcium chloride and 125 ml of 25% aqueous ammonia were added, and air was blown at room temperature for 3 hours to prepare bis [2- (3,5-di-tert-butyl-o-benzoquinone mono).
imine) -4,6-di-tert-butyl phenolato] Calcium (II)
Was precipitated. 12 g of polyvinyl butyral (Denka Butyral # 4000-2, manufactured by Denki Kagaku Kogyo Co., Ltd.), CAB381-2
0 (Cellulose acetate butyrate manufactured by Eastman Chemical Co., Ltd.)
12g, 140mg dye 1, 300mg calcium compound 1, 30
0 mg of Dye 2, 4 mg of Dye 3, 0.4 g of Sildex H121 (average size of spherical silica 12 μm manufactured by Dokai Chemical), Sildex H51 (average size of spherical silica 5 μm manufactured by Dokai Chemical) 0.
4g, 0.15g Megafax F-176P, 2g sumidur N350
0 was added to 500 g of 2-butanone and 500 g of 2-propanol with stirring, and dissolved and mixed.

The emulsion layer coating solution prepared as described above was coated on a 175 μm polyethylene terephthalate support tinted with a blue dye so as to have a silver concentration of 2.3 g / m ^2, and then coated on the surface opposite to the emulsion layer. Then, a coating solution for the back surface was applied so as to have an optical density of 810 nm of 0.7. Further, a coating solution for an emulsion surface protective layer was applied on the emulsion surface to a dry thickness of 2 μm to obtain a light-sensitive material 1-01. Also, the addition amount of Sildex H31 in the emulsion surface protective layer coating solution was 0.3 g, 15 g,
The light-sensitive materials 1-02 to 05 were obtained by adding 1.5 g of Sildex H121 instead of Sildex H31 and by adding no Sildex. Smoothness of the photosensitive material thus obtained
(The Beck smoothness was examined using Oken-type smoothness measurement described in J. TAPPI Paper Pulp Test Method No. 5.) In each case, the back surface was 90 seconds. On the emulsion side, photosensitive material 1-01 was 850 seconds, 1-02 was 1400 seconds, 1-
03 was over 650 seconds, 1-04 over 95 seconds, and 1-05 over 3000 seconds.

[0077]

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(Evaluation of friction coefficient) Dynamic friction coefficient: HEIDON-14, a surface property measuring device manufactured by Shinto Kagaku Co., Ltd.
Was used to measure the dynamic friction coefficient between the emulsion surface and the back surface. Static friction coefficient: Static friction coefficient measuring machine TYPE: H manufactured by Shinto Scientific Co., Ltd.
The coefficient of static friction between the emulsion surface and the back surface was measured using EIDON-10.

(Evaluation of uneven development) The photographic material was uniformly exposed to a density of 1.0 after development with a laser sensitometer equipped with a 820 nm diode, and processed (developed) at 120 ° C. for 15 seconds. It was evaluated visually. ◎: The entire area is uniform at a concentration of 0.99 or more and 1.01 or less.・ ・ ・: There is a slight change in the density range from 0.97 to 1.03, but the maximum density change at 1 cm 2 is 0.01 or less, which is not bothersome. Δ: There is a change in the concentration range from 0.97 to 1.03, but it is practically acceptable. X: Density unevenness such as spots or stripes was not possible.

(Evaluation of storage stability over time) Each sample processed in the same manner as in the evaluation of transportability was allowed to stand for 1 day under the conditions of 25 ° C. and 50% RH, and 10 pieces of each photographic material were placed in a bag made of a moisture-proof material. And put it in a 35.1cm x 26.9cm x 3.0cm makeup box.
After 5 days at 0 ° C (forced aging). The same treatment as that used for evaluation of photographic properties was performed on this sample and a sample prepared in the same manner as in forced aging except that the storage temperature was 4 ° C. for comparison, and the density of the fog portion was measured. The natural aging property was evaluated as a fog increase rate. (Fog increase rate) = [[(Fog of forced-aged sample) − (Fog of comparative sample)] / [(Maximum concentration of comparative sample) − (Concentration of support)] × 100 The properties are good.

(Evaluation of transportability) Each photosensitive material was 30.5 cm ×
It was cut to 25.4 cm, the corner was a round corner with an inner diameter of 0.5 cm, and it was left for 3 hours at 25 ° C-60% RH and transported 100 times using RN Auto Feeder manufactured by Fuji Photo Film Co., Ltd. The evaluation was made based on the sum of the number of conveyed sheets and the number of jammed sheets.

Table 1 shows the results. In the region of the present invention, a photosensitive material having excellent development unevenness, storage stability and transportability was obtained.

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[Table 1]

Example 2 << Preparation of Organic Acid Silver Emulsion >> 840 g of behenic acid and 95 of stearic acid
g was added to 12 liters of water, and while maintaining the temperature at 90 ° C., a solution prepared by dissolving 48 g of sodium hydroxide and 64 g of sodium carbonate in 1.5 liters of water was added. After stirring for 30 minutes, the temperature was raised to 50 ° C., 1.1 L of a 1% aqueous solution of N-bromosuccinimide was added, and then 2.3 L of a 17% aqueous solution of silver nitrate was gradually added with stirring. Further, the liquid temperature was set to 34 ° C., and 1.5 liters of a 2% aqueous solution of potassium bromide was added over 2 minutes with stirring, followed by stirring for 30 minutes, and 2.4 liters of a 1% aqueous solution of N-bromosuccinimide was added. While stirring the aqueous mixture, 31.2% by weight of a polyvinyl acetate
After adding g, the mixture was allowed to stand for 10 minutes, separated into two layers, the aqueous layer was removed, and the remaining gel was washed three times with water. The thus obtained mixture of gel-like behenic acid / silver stearate and silver bromide was dispersed in 1800 g of a 2.6% isopropyl alcohol solution of polyvinyl butyral (Denka butyral # 3000-K, manufactured by Denki Kagaku Kogyo Co., Ltd.). Butyral (Denka Butyral # 400 manufactured by Denki Kagaku Kogyo Co., Ltd.)
0-2) Disperse with 600 g of isopropyl alcohol and 300 g of organic acid silver salt emulsion (average minor axis 0.04 μm, average major axis 1.2 μm,
Needle-shaped particles with a coefficient of variation of 30%).

<< Preparation of Emulsion Layer Coating Solution >> Each of the chemicals was added to the above-obtained organic acid silver emulsion in the following amount per mol of silver. Sodium phenylthiosulfonate 10 at 25 ° C
mg, 70 mg of dye a, 2-mercapto-5-methylbenzimidazole 2 g, 4-chlorobenzophenone-2-carboxylic acid 26
g, 2-butanone 580 g, and dimethylformamide 220 g were added with stirring, and left for 3 hours. Then, 5 g of 5-tribromomethylsulfonyl-2-methylthiadiazole, 2-g
6 g of tribromomethylsulfonylbenzothiazole, 4,
6-ditrichloromethyl-2-phenyltriazine 5 g, disulfide compound a 2 g, 1,1-bis (2-hydroxy-3,5-
Dimethylphenyl) -3,5,5-trimethylhexane 180 g, tetrachlorophthalic acid 5.5 g, phthalazine 12 g, 3 g of hydrazine derivative a, Megafax F-176P (a fluorosurfactant manufactured by Dainippon Ink and Chemicals, Inc.) ) 1.1g, 2-butanone
590 g and 10 g of methyl isobutyl ketone were added with stirring.

<< Emulsion Surface Protective Layer Coating Solution >> 75 g of CAB171-15S (cellulose acetate butyrate manufactured by Eastman Chemical Co., Ltd.)
5.7 g of methylphthalic acid, 1.5 of tetrachlorophthalic anhydride
g, 0.3 g of Megafax F-176P, Sildex H31 (Dokai Chemical Co., Ltd., spherical silica average size 3 μm), 2 g, sumidurN
3500 (polyisocyanate manufactured by Sumitomo Bayer Urethane Co.) 7.
A solution prepared by dissolving 2 g in 3070 g of 2-butanone and 30 g of ethyl acetate was prepared.

<< Preparation of Support having Back Surface >> 6 g of polyvinyl butyral (Denka Butyral # 4000-2 manufactured by Denki Kagaku Kogyo KK), Sildex H121 (average size of spherical silica 12 μm manufactured by Dokai Chemical Co., Ltd.) 0.2 g, Sildex H51 (Tokai Chemical Co., Ltd., 0.2 g of true spherical silica, average size: 5 μm) and 0.1 g of Megafax F-176P were added to 64 g of 2-propanol while stirring, and dissolved and mixed. In addition, 420 mg of dye 1
A solution of 10 g of methanol and 20 g of acetone and a solution of 1.1 g of 3-isocyanatomethyl-3,5,5-trimethylhexyl isocyanate in 7 g of ethyl acetate were added to prepare a coating solution. A back surface coating solution was applied onto a polyethylene terephthalate film having a moisture-proof undercoat containing vinylidene chloride on both sides so as to have an optical density of 0.7 at 633 nm.

After the emulsion layer coating solution was coated on the support prepared as described above so that the silver content was 2 g / m ² , the emulsion surface protective layer coating solution was dried on the emulsion surface to a dry thickness of 2 μm. To give photosensitive material 2-01. Further, the photosensitive material 2-02 what was not added emulsion surface protective layer coating solution Shirudekussu H31, the a Sildex H31 which the polydimethylsiloxane having an average degree of polymerization of 500 and 0.2 g / m ² was added 20 mg / m ² Sensitive material 2-03.

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(Evaluation of photographic performance of photosensitive material) After exposing the photographic material with a 633 nm He-Ne laser sensitometer, the photographic material was heated at 115 ° C.
Processed (developed) for 25 seconds. Further, the developed material was exposed to a halogen lamp for 15 seconds to decolor the dye in the back layer.
The image thus obtained was evaluated by a densitometer. The results of the measurement were evaluated in terms of Dmin and sensitivity (the reciprocal of the ratio of the exposure amount giving a density 3.0 higher than Dmin). The gradient of the straight line connecting the points of density 0.3 and 3.0 in the characteristic curve is shown as gradation γ. The sensitivity was expressed as a relative value with the photosensitive material 2-01 being 100.

Further, development unevenness and the like were evaluated in the same manner as in Example 1. Table 2 shows the results. High sensitivity, high contrast,
A photosensitive material having low fog and good preservability was obtained without development unevenness.

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[Table 2]

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According to the present invention, high feeling, low fog, high contrast,
In addition, a photosensitive material having good storage stability and excellent development unevenness and transportability was obtained.

Claims (4)

[Claims] 1. A photothermographic material having a layer containing photosensitive silver halide grains on one side of a support, wherein the coefficient of dynamic friction between the surface having the photosensitive layer and the other surface is 0.1 or more.
A photothermographic material characterized by being 0.25 or less. 2. A photothermographic material according to claim 1, wherein the coefficient of static friction between the surface having the photosensitive layer and the other surface is 1.5 to 5 times the dynamic friction coefficient. 3. The photothermographic material according to claim 1, wherein the coefficient of kinetic friction is 0.1 or more and 0.25. 4. The photothermographic material according to claim 1, wherein the photothermographic material is in the form of a sheet.