JP2000310836A - Packed article of heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a picture which is low in fogging, high in Dmax (the maximum density) and less in rise of fogging and sensitivity fluctuation when stored by packaging a heat developable photosensitive material by adjusting humidity so that the relative humidity is within a specific range. SOLUTION: A packed article is formed by packing the heat developable photosensitive material having non-photosensitive silver salt, photosensitive silver halide, a core-making agent and a binder on a support so that the inside relative humidity is >=10% and <=50%. The case where the relative humidity inside the packed product exceeds 50% is not preferable because a rise in fogging and sensitivity fluctuation due to storing are large. Further, the case where the relative humidity inside the packed article is <10% is not preferable because the activity of heat developing is lowered, thus sufficient picture density is not obtained. Accordingly, by adjusting the relative humidity at >=10% and <=50%, a rise in fogging (D min) and sensitivity fluctuation due to the storing of the heat developable photosensitive material is effectively suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a packaged photothermographic material. In particular, the present invention relates to a package of a photothermographic material for a scanner and an image setter suitable for photoengraving, and more particularly, has a low fog, a high Dmax (maximum density), and a small increase in fog during storage and little fluctuation in sensitivity. The present invention relates to a photothermographic material package for photoengraving capable of obtaining an image and an image forming method.

[0002]

2. Description of the Related Art There are many known photosensitive materials having a photosensitive layer on a support and forming an image by exposing the image. Among them, a technique for forming an image by thermal development is a system that can simplify environmental preservation and image forming means. In recent years, environmental preservation in the photoengraving field,
From the viewpoint of space saving, it is strongly desired to reduce the amount of processing waste liquid. There, you can use a laser scanner or a laser imagesetter to make the exposure more efficient,
There is a need for a technique relating to a photothermographic material for photolithography capable of forming a sharp black image having high resolution and sharpness. In these photothermographic materials,
By eliminating the use of solution processing chemicals, it is possible to provide customers with a simpler and more environmentally friendly thermal development processing system.

A method for forming an image by thermal development is described in, for example, US Pat. Nos. 3,152,904 and 3,457,075 and D.C. Morgan and B.A. Sherry (Sh
ely) "Heat treated silver system (Therm
ally Processed Silver Systems) A "(Imaging
Processings and Materials (Imaging Proce
sses and Materials) Neblette 8th edition, Sturgi (Stur
ge), V.I. Walworth, A .; Edited by Shepp, page 2, 1969). Such photosensitive materials are prepared by dispersing a reducible non-photosensitive silver source (eg, an organic silver salt), a catalytically active amount of a photocatalyst (eg, silver halide), and a silver reducing agent, usually in an organic binder matrix. It is contained in. The photosensitive material is stable at room temperature, but when heated to a high temperature (for example, 80 ° C. or higher) after exposure, silver is reduced through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and a reducing agent. Generate This oxidation-reduction reaction is promoted by the catalytic action of the latent image generated by the exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image.

Although the photothermographic materials have been known in the art, most of them are formed by applying a coating solution using an organic solvent such as toluene, methyl ethyl ketone (MEK) or methanol as a solvent. Has formed. The use of an organic solvent as a solvent is disadvantageous not only in adverse effects on the human body in the manufacturing process but also in cost due to recovery of the solvent and the like. Therefore, a method of forming a photosensitive layer (hereinafter, also referred to as “aqueous photosensitive layer”) using a coating solution of a water solvent which does not have a fear of adversely affecting the human body has been considered. For example, JP-A-49-52626 and JP-A-53-116144 describe examples using gelatin as a binder. Japanese Patent Application Laid-Open No. 50-151138 discloses an example using polyvinyl alcohol as a binder. Further, Japanese Patent Application Laid-Open No. Sho 60-61747 describes an example in which gelatin and polyvinyl alcohol are used in combination. As another example, JP-A-58-28737 describes an example of a photosensitive layer using water-soluble polyvinyl acetal as a binder.

Certainly, when such a binder is used, the photosensitive layer can be formed using a coating solution of an aqueous solvent, and the advantages in terms of environment and cost are great. However,
When a polymer such as gelatin, polyvinyl alcohol, or water-soluble polyacetal is used as a binder, the compatibility with the organic silver salt is poor, so that not only a coated material that can be practically used on the coated surface quality is not obtained, but also the silver tone of the developed portion is reduced. It becomes brown or yellow which is far from the originally preferred black,
Only those having a markedly impaired commercial value, such as a low blackening density in exposed areas and a high density in unexposed areas, were obtained. European Patent 762,196, JP-A-9-90550 and the like, the photosensitive silver halide grains used in the photothermographic material described in Periodic Table VI.
It discloses that a group I or group VIII (groups 7 to 10) metal ion or metal complex ion is contained, and that a hydrazine derivative is contained in a photosensitive material to obtain high contrast photographic characteristics. However, when a nucleating agent such as a hydrazine derivative is used in combination with the binder used in the above-mentioned aqueous solvent coating solution, a high-contrast image can be obtained. And there is a problem that the sensitivity fluctuation is large. Therefore, fog is low and D
There has been a demand for a technique for providing a photothermographic material which is high in maximum (maximum density), capable of obtaining an image with little fog increase and sensitivity fluctuation during storage and which is advantageous in terms of environment and cost.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems of the prior art. That is, the present invention makes it possible to obtain an image having low fog, high Dmax (highest density), and little fog increase and sensitivity fluctuation during storage, particularly for photoengraving, especially for scanners and imagesetters. An object of the present invention is to provide a package of a photothermographic material and an image forming method using the photothermographic material.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, the relative humidity was 10
% Of the photothermographic material and packaging the photothermographic material so as to provide a desired effect, leading to the present invention. Was. That is, according to the present invention, a photothermographic material having a non-photosensitive silver salt, a photosensitive silver halide, a nucleating agent and a binder on a support is packaged with a packaging material. And the relative humidity in the package is 10%
A package of the photothermographic material characterized by being at least 50% by weight.

The photothermographic material contained in the package of the present invention is preferably formed in a roll shape by winding it around a cylindrical core having a water content of 4% by weight or more and 7% by weight or less. The nucleating agent constituting the photothermographic material is a substituted alkene derivative represented by the following formula (1),
And at least one compound selected from the group consisting of a substituted isoxazole derivative represented by the following formula and an acetal compound represented by the following formula (3).

Embedded image [In the formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent, and Z represents an electron-withdrawing group or a silyl group. In the formula (1), R ¹ and Z, R ² and R
³ , R ¹ and R ² , and R ³ and Z may be bonded to each other to form a cyclic structure. In the formula (2), R
⁴ represents a substituent. In the formula (3), X and Y each independently represent a hydrogen atom or a substituent;
Each independently represents an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic oxy group, a heterocyclic thio group or a heterocyclic amino group. In the formula (3), X and Y, and A and B may be bonded to each other to form a cyclic structure. ]

The photothermographic material contained in the package of the present invention has a glass transition temperature of -3 at least 50% by weight of the binder of the image forming layer containing the photosensitive silver halide.
It is preferable to use a polymer latex having a temperature of 0 ° C or more and 40 ° C or less. The photothermographic material is preferably cut with a cutting blade having a blade edge angle of 60 degrees or more and 90 degrees or less. Furthermore, the packaging material has a thickness of 1
It is preferable to contain a metal foil having a size of not less than μm and not more than 50 μm. Further, according to the present invention, in the photothermographic image forming method of taking out the photothermographic material contained in the package, exposing the photothermographic material and thermally developing the photothermographic material, the photothermographic material before the thermal development is used. Temperature of 20 ° C or higher and 40 ° C
A method for forming a heat-developable image, wherein the method is adjusted to the following range, is also provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments and a method of implementing the present invention will be described in detail. In the package of the present invention, a photothermographic material having a non-photosensitive silver salt, a photosensitive silver halide, a nucleating agent and a binder on a support is adjusted so that the internal relative humidity is 10% or more and 50% or less. It is characterized by being packed in As described above, the relative humidity is increased from 10% to 50%.
By adjusting as follows, it is possible to effectively suppress an increase in fog (Dmin) and a change in sensitivity due to storage of the photothermographic material. The photothermographic material is usually cut into a predetermined size and stored, but the fog rise near the cut portion at that time can be effectively suppressed according to the present invention. For example, it is defined that the vicinity of the cut portion has a width corresponding to about 1% of the entire length of the photothermographic material after cutting,
When this portion is called an edge portion, it is possible to effectively suppress an increase in fog at the edge portion. If the relative humidity in the package exceeds 50%, it is not preferable because fog increases and sensitivity changes greatly due to storage. On the other hand, when the relative humidity in the package is less than 10%, the activity of the heat development is lowered and a sufficient image density cannot be obtained, which is not preferable. In the present invention, the relative humidity in the package is 10% or more and 50% or more.
Although it is set below, it is particularly preferable to set it to 20% or more and 40% or less. The method of adjusting the humidity in the package is not particularly limited, and can be appropriately adjusted according to a conventional method. The temperature inside the package is not particularly limited, but is usually set to about 25 ° C.

The packaging material used for the package of the present invention is not particularly limited as long as it can maintain the relative humidity inside at 10% or more and 50% or less. However, it is preferable to use a light-shielding packaging material. For example, various polymer materials and polymer resins such as polyethylene, polyethylene terephthalate, nylon, polypropylene, and polystyrene can be used. A material obtained by laminating a metal foil such as an aluminum foil or paper on these materials can also be used. For specific packaging materials and shapes, see JP-A-6-214350, Japanese Utility Model Application Laid-Open No. 3-713.
No. 46, JP-A-8-62783 and JP-A-8-62783.
This is exemplified in JP-A-234370. The thickness of the material depends on the material.
m is preferable. When the metal foil is contained in the packaging material of the laminate, the thickness of the metal foil is preferably 1 μm or more and 50 μm or less, more preferably 3 μm or more and 20 μm or less. In the present invention, it is preferable to use a packaging material containing a metal foil of such a size.

The photothermographic material contained in the package of the present invention comprises a non-photosensitive silver salt, a photosensitive silver halide,
The details are not particularly limited as long as it has a nucleating agent and a binder. A preferred photothermographic material has, on a support, an image forming layer containing an organic silver salt as a non-photosensitive silver salt and a binder, and contains a photosensitive silver halide in a layer on the image forming layer side. And a high contrast photographic material further containing a nucleating agent. The image forming layer is preferably a photosensitive layer containing a photosensitive silver halide.

The organic silver salt used as the non-photosensitive silver salt in the present invention is relatively stable to light, but the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent. Below, 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 (C 10-30, preferably 15-28
Silver salts of long chain fatty carboxylic acids are preferred. Ligand 4.0
Complexes of organic or inorganic silver salts having a complex stability constant in the range of 110.0 are also preferred. The silver donor material can preferably make up 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 the aliphatic carboxylic acid include silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate, and silver maleate. Silver, silver tartrate, silver linoleate, silver butyrate and silver camphorate, and mixtures thereof.

In the present invention, it is preferable to use silver behenate having a silver behenate content of 85 mol% or more, more preferably 95 mol% or more, of the above-mentioned organic silver salts or a mixture of the organic silver salts. . Here, the content of silver behenate indicates the molar fraction of silver behenate with respect to the organic acid silver used. As the organic acid silver other than silver behenate contained in the organic acid silver used in the present invention, those mentioned above can be preferably used. The silver salt of an organic acid preferably used in the present invention is prepared by reacting a silver nitrate solution with a solution or suspension of an alkali metal salt (including Na salt, K salt, Li salt and the like) of the organic acid described above. . The alkali metal salt of an organic acid is obtained by treating the above organic acid with an alkali. The preparation of the organic silver salt used in the present invention can be carried out in any suitable vessel, either batchwise or continuously. The stirring in the reaction vessel can be performed by any stirring method depending on the required characteristics of the particles. The silver salt of an organic acid can be prepared by adding a silver nitrate aqueous solution gradually or rapidly to a reaction vessel containing an alkali metal salt solution or suspension of an organic acid, or by preparing an organic acid prepared beforehand in a reaction vessel containing a silver nitrate aqueous solution. Preferably, a method of gradually or rapidly adding an alkali metal salt solution or suspension, and a method of simultaneously adding a previously prepared aqueous solution of silver nitrate and a solution or suspension of an organic acid alkali metal salt into a reaction vessel are preferably used. Can be.

The silver nitrate aqueous solution and the organic acid alkali metal salt solution or suspension may be of any concentration for controlling the particle size of the prepared organic acid silver, and may be added at any addition rate. Can be. The silver nitrate aqueous solution and the organic acid alkali metal salt solution or suspension can be added by a method of adding at a constant addition rate, an accelerated addition method by an arbitrary time function, or a deceleration addition method. Further, it may be added to the liquid surface or may be added to the reaction solution. In the case of a method in which a previously prepared aqueous silver nitrate solution and an organic acid alkali metal salt solution or suspension are simultaneously added to the reaction vessel, either the silver nitrate aqueous solution or the organic acid alkali metal salt solution or suspension is preceded. Although it can be added, it is preferable to add the silver nitrate aqueous solution in advance. The degree of precedence is preferably 0 to 50 vol% of the total amount added, and 0 to 2 vol%.
5 vol% is particularly preferred. As described in JP-A-9-127643, a method of adding while controlling the pH or silver potential of the reaction solution during the reaction can also be preferably used.

The pH of the silver nitrate aqueous solution or organic acid alkali metal salt solution or suspension to be added can be adjusted according to the required characteristics of the particles. An optional acid or alkali can be added for pH adjustment. Depending on the required characteristics of the particles, for example, the temperature in the reaction vessel can be set arbitrarily for controlling the particle size of the prepared organic acid silver salt. Alternatively, the suspension can also be adjusted to any temperature. The organic acid alkali metal salt solution or suspension is preferably heated and kept at 50 ° C. or higher in order to ensure fluidity of the solution. The organic acid silver used in the present invention is preferably prepared in the presence of a tertiary alcohol. The tertiary alcohol preferably has a total carbon number of 15 or less, particularly preferably 10 or less. Examples of preferred tertiary alcohols include tert-butanol and the like,
The present invention is not limited to this. Third used in the present invention
The alcohol may be added at any time during the preparation of the organic acid silver salt, but it is preferable to add the alcohol during the preparation of the organic acid alkali metal salt and dissolve the organic acid alkali metal salt before use. The amount of the third alcohol can be used freely between 0.01 and 10 by weight ratio to of H ₂ O as a solvent at the time of organic acid silver preparation, the range of 0.03 to 1 is preferred.

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. 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, minor axis 0.01 μm or more and 0.15 μm or less, major axis 0.10 μm or more
4.0 μm or less is more preferable. The particle size distribution of the organic silver salt is preferably monodispersed. Monodisperse and the minor axis, the percentage of the value obtained by dividing the standard deviation of the length of each major axis by each minor axis, major axis is preferably 100% or less, more preferably
It is at most 80%, more preferably at most 50%. 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 the monodispersity, there is a method of determining the standard deviation of the volume-weighted average diameter of the organic silver salt, the percentage of the value divided by the volume-weighted average diameter (coefficient of variation) is preferably 100% or less, more Preferably 80
%, More preferably 50% or less. As a measuring method, for example, the particle size (volume weighted average diameter) 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 is obtained. Can be.

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, or floc-forming water washing by a coagulation method can be preferably used. In the present invention, for the purpose of obtaining an organic silver salt solid dispersion having a high S / N, a small particle size, and no aggregation, the organic silver salt containing an image forming medium is contained, and the photosensitive silver salt is substantially contained. It is preferable to use a dispersion method in which an aqueous dispersion is converted into a high-speed stream and then the pressure is reduced. After passing through such a process, the mixture is mixed with a photosensitive silver salt aqueous solution to produce a photosensitive image forming medium coating solution. When a photothermographic material is prepared using such a coating solution, a haze is low, and a low-fogging, high-sensitivity photothermographic material can be obtained. On the other hand, when the photosensitive silver salt is coexistent when the light is converted into a high-pressure, high-speed flow and dispersed, the fog increases and the sensitivity is remarkably lowered. When an organic solvent is used instead of water as a dispersion medium, haze increases, fog increases, and sensitivity tends to decrease. On the other hand, when a conversion method for converting a part of the organic silver salt in the dispersion to the photosensitive silver salt is used instead of the method of mixing the aqueous solution of the photosensitive silver salt, the sensitivity is reduced.

In the above, the aqueous dispersion which is dispersed after being converted to high pressure and high speed substantially does not contain a photosensitive silver salt, and its content is based on the non-photosensitive organic silver salt. 0.
The content is 1 mol% or less, and the photosensitive silver salt is not positively added. In the present invention, for the solid dispersion apparatus and the technology used to carry out the dispersion method as described above, for example, "dispersion system rheology and dispersion technology"
(Toshio Kajiuchi, Hiroki Usui, 1991, Shinzansha Publishing Co., Ltd.,
p357-p403), "Progress in Chemical Engineering Vol. 24" (incorporated association)
Edited by The Society of Chemical Engineers, Tokai Branch, 1990, Maki Shoten, p184-p18
5), etc., the dispersion method according to the present invention is based on a method in which after a water dispersion containing at least an organic silver salt is pressurized by a high-pressure pump or the like and fed into a pipe, a thin slit provided in the pipe is formed. This is a method in which fine dispersion is performed by causing the dispersion to pass through and then causing a sharp pressure drop in the dispersion.

The high-pressure homogenizer to which the present invention relates is generally (a) a "shear force" generated when the dispersoid passes through a narrow gap at a high pressure and a high speed, and (b) a dispersoid is subjected to a high pressure to a normal pressure. It is considered that the particles are dispersed into fine particles by a dispersing force such as “cavitation force” generated when the particles are released. As an example of this type of dispersing apparatus, a Gaulin homogenizer is mentioned in the past.In this apparatus, the liquid to be dispersed sent at a high pressure is converted into a high-speed flow through a narrow gap on a cylindrical surface, and the force is applied to the surrounding wall by the force. The particles collide and are emulsified and dispersed by the impact force. Working pressure is generally 10
0~600kg / cm ^2, the flow rate is in the range of a few M～30m / sec, be devised that the high flow rate portion was devised such increasing the number collisions in the saw-toothed in order to increase the dispersion efficiency I have. On the other hand, in recent years, apparatuses capable of dispersing at higher pressure and higher flow rate have been developed, and typical examples thereof include a microfluidizer (Microfluidex International Corporation) and a nanomizer (specialized machine). Industrial Co., Ltd.).

The dispersion apparatus suitable for the present invention is a microfluidizer M-110S-EH manufactured by Microfluidics International Corporation.
(With G10Z interaction chamber), M-
110Y (with H10Z interaction chamber), M-140K (with G10Z interaction chamber), HC-5000 (L30Z or H23
With 0Z interaction chamber), HC-80
00 (with an E230Z or L30Z interaction chamber) and the like. Using these devices,
After the aqueous dispersion containing at least the organic silver salt is pressurized by a high-pressure pump or the like and sent into the pipe, a desired pressure is applied by passing through a narrow slit provided in the pipe, and thereafter, the inside of the pipe is It is possible to obtain an optimal organic silver salt dispersion for the present invention by causing a rapid pressure drop in the dispersion by, for example, rapidly returning the pressure to the atmospheric pressure.

It is preferable that the raw material liquid is preliminarily dispersed before the dispersion operation. As means for preliminary dispersion, known dispersion means (e.g., high-speed mixer, homogenizer, high-speed impact mill, Banbury mixer, homomixer, kneader, ball mill, vibration ball mill, planetary ball mill, attritor, sand mill, bead mill, colloid mill,
Jet mill, roller mill, tron mill, high-speed stone mill) can be used. Instead of mechanically dispersing, fine particles may be formed by coarsely dispersing in a solvent by controlling the pH, and then changing the pH in the presence of a dispersing aid. At this time, an organic solvent may be used as a solvent used for the coarse dispersion, and the organic solvent is usually removed after completion of the fine particle formation.

In the dispersion of an organic silver salt, it is possible to obtain a desired particle size by adjusting the flow rate, the differential pressure at the time of pressure drop, and the number of treatments. / Sec to 600m / sec, differential pressure at pressure drop
Is preferably in the range of 900~3000kg / cm ^2, the flow rate is 300 meters / sec to 60
More preferably, the pressure difference at the time of 0 m / sec and the pressure drop is in the range of 1500 to 3000 kg / cm ² . The number of times of distributed processing can be selected as needed, and usually 1 to 10 times of processing is selected,
From the viewpoint of productivity, the number of treatments is selected from about 1 to 3 times.
High temperature of such an aqueous dispersion under high pressure is not preferable from the viewpoint of dispersibility and photographic properties, and at a high temperature such as exceeding 90 ° C., the particle size tends to increase,
Fog tends to be high. Therefore, in the present invention, the step before the conversion to the high pressure and high flow rate, the step after the pressure is reduced, or both of these steps include a cooling step, and the temperature of such water dispersion is reduced by the cooling step. ~ 90
C. It is preferably maintained in the range of 5 ° C., more preferably in the range of 5 to 80 ° C., particularly preferably in the range of 5 to 65 ° C. In particular, it is effective to provide the above cooling step at the time of high-pressure dispersion in the range of 1500 to 3000 kg / cm ² . As the cooler, a double tube, a double tube using a static mixer, a multi-tube heat exchanger, a coiled tube heat exchanger, or the like can be appropriately selected according to the required heat exchange amount.
Further, in order to increase the efficiency of heat exchange, it is sufficient to select a suitable one such as a pipe thickness, a wall thickness and a material in consideration of a working pressure. As the refrigerant used for the cooler, use 20 ° C well water, 5-10 ° C cold water treated with a refrigerator, and, if necessary, -30 ° C ethylene glycol / water refrigerant, etc., based on the heat exchange amount. You can also.

In the dispersion operation, it is preferable to disperse the organic silver salt in the presence of an aqueous solvent-soluble dispersant (dispersion aid). Examples of the dispersing agent include polyacrylic acid, a copolymer of acrylic acid, a maleic acid copolymer, a maleic acid monoester copolymer, a synthetic anionic polymer such as an acrylomethylpropanesulfonic acid copolymer, and carboxymethyl. Starch, semi-synthetic anionic polymers such as carboxymethylcellulose, alginic acid, anionic polymers such as pectic acid, compounds described in JP-A-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. Call compounds, particularly preferred water-soluble cellulose derivatives.

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 the 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 mechanical dispersion, pH
By performing control, the particles may be roughly dispersed in a solvent, and then the pH may be changed in the presence of a dispersing agent 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 completion of the fine particle formation. The prepared dispersion is stored with stirring for the purpose of suppressing sedimentation of fine particles during storage, or stored in a highly viscous state by a hydrophilic colloid (for example, in a jelly state using gelatin). You can also. Further, a preservative can be added for the purpose of preventing the propagation of various bacteria during storage.

The particle size (volume-weighted average diameter) of the organic silver salt solid fine particle dispersion used in the present invention is determined, for example, by irradiating a solid fine particle dispersion dispersed in a liquid with a laser beam and changing the fluctuation of the scattered light with time. Can be determined from the particle size (volume-weighted average diameter) obtained by obtaining the autocorrelation function for. Average particle size 0.05μm or more 10.0μ
m or less is preferable. The average particle size is more preferably 0.1 μm or more and 5.0 μm or less, and still more preferably the average particle size is 0.1 μm or more and 2.0 μm or less. The particle size distribution of the organic silver salt is preferably monodispersed.
Specifically, the percentage (coefficient of variation) of the value obtained by dividing the standard deviation of the volume-weighted average diameter by the volume-weighted average diameter is 80% or less, more preferably 50% or less, and still more preferably 30% or less. The shape of the organic silver salt can be measured from a transmission electron microscope image of the organic silver salt dispersion. The organic silver salt solid fine particle dispersion used in the present invention comprises at least an organic silver salt and water. The ratio between the organic silver salt and water is not particularly limited, but the ratio of the organic silver salt to the whole is preferably 5 to 50% by weight, and more preferably 10 to 3% by weight.
A range of 0% by weight is preferred. It is preferable to use the above-mentioned dispersing aid, but it is preferable to use the dispersing aid in the minimum amount within a range suitable for minimizing the particle size. A range of weight% is preferred.

In the present invention, it is possible to produce a photosensitive material by mixing an aqueous dispersion of an organic silver salt and an aqueous dispersion of a photosensitive silver salt, but the mixing ratio of the organic silver salt to the photosensitive silver salt depends on the purpose. The ratio of the photosensitive silver salt to the organic silver salt is 1 to 3
It is preferably in the range of 0 mol%, more preferably 3 to 20 mol%, especially 5 to 20 mol%.
It is preferably in the range of ~ 15 mol%. Mixing two or more aqueous dispersions of organic silver salts with two or more aqueous dispersions of photosensitive silver salts during mixing is a method preferably used for adjusting photographic characteristics. The organic silver salt in the present invention can be used in a desired amount, if indicated by the coating amount per the photosensitive material 1 m ^2, preferably 0.1-5 g / m ² as silver amount, more preferably in 1 to 3 g / m ² is there.

In the present invention, it is preferable to add a metal ion selected from Ca, Mg, Zn and Ag to the non-photosensitive organic silver salt. Regarding the addition of a metal ion selected from Ca, Mg, Zn and Ag to the non-photosensitive organic silver salt, it is preferable to add it in the form of a non-halide, water-soluble metal salt, specifically, nitrate or sulfuric acid. It is preferably added in the form of a salt or the like. The addition of a halide is not preferred because it deteriorates the image storability of the processed photosensitive material due to light (such as room light or sunlight), that is, the so-called printout property. For this reason, in the present invention, it is preferable to add in the form of a water-soluble metal salt which is not the above-mentioned halide. The addition time of the metal ion selected from Ca, Mg, Zn and Ag preferably used in the present invention is, after the formation of the particles of the non-photosensitive organic silver salt, immediately after the formation of the particles, before the dispersion,
The timing may be any time before the application, such as after the dispersion and before and after the preparation of the coating solution, and preferably after the dispersion and before and after the preparation of the coating solution. Ca, Mg, Zn and A in the present invention
g is preferably from 10 ^-3 to 10 ^-1 mol per mol of non-photosensitive organic silver, particularly 5 ×
10 ^{-3 to} 5 × 10 ^-2 mol is preferred.

The photothermographic material of the present invention contains a photosensitive silver halide. The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition, and silver chloride,
Silver chlorobromide, silver bromide, silver iodobromide, and silver iodochlorobromide can be used. The distribution of the halogen composition in the grains may be uniform, the halogen composition may change stepwise, or may change continuously. Further, silver halide grains having a core / shell structure can be preferably used. As a structure, a core having a 2 to 5 layer structure, more preferably a 2 to 4 layer structure /
Shell particles can be used. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used. Methods for forming photosensitive silver halide are well known in the art, for example, Research Disclosure No. 17029, June 1978, and U.S. Pat.
The method described in US Patent No. 700,458 can be used.Specifically, a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to gelatin or another polymer solution, Thereafter, a method of mixing with an organic silver salt is used. The grain size of the photosensitive silver halide is preferably small for the purpose of suppressing white turbidity after image formation, specifically 0.20 μm or less, more preferably 0.01 μm or more and 0.15 μm or less, and further more preferably 0.02 μm or more. 0.12 μm or less is preferred. 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 100: 1 to 2: 1, more preferably 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,
80% or more is more preferable. The Miller index [100] plane ratio was determined by T. Tani; J. Imaging Sci., 29, 165 (1985), which utilizes the adsorption dependence of [111] and [100] planes on the adsorption of sensitizing dyes. It can be determined by the method described.

The light-sensitive silver halide grains used in the present invention may be selected from Group VII or VIII (7 to 10) of the periodic table.
Group) metal or metal complex. VI of the Periodic Table
Rhodium, rhenium, ruthenium, osmium and iridium are preferred as the Group I or Group VIII metal or the central metal of the metal complex. One type of these metal complexes may be used, or two or more types of complexes of the same metal and different metals may be used in combination. The preferred content is 1 × per mole of silver.
The range of 10 ^-9 mol to 1 × 10 ^-3 mol is preferable, and
The range is more preferably from 10 ^-8 mol to 1 × 10 ^-4 mol.
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 rhodium compound used in the present invention,
Can be a water-soluble rhodium compound. example
For example, rhodium (III) halide compounds or rhodium
Halogen, amines, oxalato as ligands
Such as hexachlororhodium (III)
Complex salt, pentachloroacolodium (III) complex salt, tetra
Chlorodiacodium (III) complex salt, hexabromodolo
(III) complex salt, hexaammine rhodium (III) complex
Salts, trioxalatrodium (III) complex salts and the like.
You. These rhodium compounds can be dissolved in water or a suitable solvent.
Dissolves rhodium compound solution
In general, a common method for
Aqueous hydrogenogen solution (for example, hydrochloric acid, bromic acid, hydrofluoric acid, etc.),
Alternatively, an alkali halide (eg, KCl, NaCl, KBr,
NaBr) can be used. Water soluble
When preparing silver halide instead of using rhodium,
Another silver halide grain pre-doped with rhodium
It is also possible to add and dissolve. These logistics
The amount of the compound added is 1 × 1 per mol of silver halide.
0^-8Mol to 5 × 10^-FourThe molar range is preferred, especially preferred.
Or 5 × 10^-8Mol ~ 1 x 10 ^-FiveIs a mole. these
The compound (1) is added during the production of silver halide emulsion grains and
And at each stage before coating the emulsion.
But added especially during emulsion formation,
It is preferably incorporated into

Rhenium, ruthenium and osmium used in the present invention are described in JP-A-63-2042 and JP-A-1-285941.
The compounds are added in the form of water-soluble complex salts described in JP-A Nos. 2-20852 and 2-20855. Particularly preferred is a six-coordinate complex represented by the following formula. [ML ₆ ] ⁿ -where M represents Ru, Re, or Os, L represents a ligand, and n represents 0, 1, 2, 3, or 4. In this case, the counter ion is not important and ammonium or alkali metal ions are used. Preferred ligands include halide ligands, cyanide ligands, cyanide ligands, nitrosyl ligands, thionitrosyl ligands, and the like. Examples of specific complexes used in the present invention are shown below, but the present invention is not limited thereto.

[ReCl ₆ ] ^3- [ReBr ₆ ] ^3- [ReCl ₅ (NO)] ^2- [Re (NS) Br ₅ ] ^2- [Re (NO) (CN) ₅ ] ^2- [Re (O ) ₂ (CN) ₄ ] ^3- [RuCl ₆ ] ^3- [RuCl ₄ (H ₂ O) ₂ ] ^- [RuCl ₅ (H2O)] ^2- [RuCl ₅ (NO)] ^2- [RuBr ₅ (NS) ] ^2- [Ru (CO) ₃ Cl ₃ ] ^2- [Ru (CO) Cl ₅ ] ^2- [Ru (CO) Br ₅ ] ^2- [OsCl ₆ ] ^3- [OsCl ₅ (NO)] ^2- [ _{Os (NO) (CN) 5} ] 2- [Os (NS) Br 5] 2- [Os (O) 2 (CN) 4] 4- the amount of these compounds per mol of silver halide 1
The range is preferably from × 10 ^-9 mol to 1 × 10 ^-4 mol, and particularly preferably from 1 × 10 ^-8 mol to 1 × 10 ^-5 mol.

These compounds can be appropriately added at the time of the production of silver halide emulsion grains and at each stage before coating the emulsion.
It is preferably incorporated into silver halide grains. In order to add these compounds during silver halide grain formation and incorporate them into silver halide grains, a metal complex powder or an aqueous solution dissolved together with NaCl or KCl is added to a water-soluble salt or a water-soluble salt during grain formation. A method in which silver halide grains are added to a neutral halide solution, or a third solution is added when a silver salt and a halide solution are simultaneously mixed, and silver halide grains are prepared by a three-solution simultaneous mixing method, or a grain formation method. There is a method in which a required amount of an aqueous solution of a metal complex is charged into a reaction vessel. In particular, a method of adding a powder or an aqueous solution dissolved together with NaCl and KCl to a water-soluble halide solution is preferable. In order to add the metal complex to the surface of the particles, a required amount of an aqueous solution of a metal complex can be charged into the reaction vessel immediately after the formation of the particles, during or during the physical ripening, or at the time of chemical ripening.

Various compounds can be used as the iridium compound used in the present invention. Examples thereof include hexachloroiridium, hexaammineiridium, trioxalatoiridium, hexacyanoiridium, and pentachloronitrosyliridium. These iridium compounds are used after being dissolved in water or a suitable solvent. However, a method generally used for stabilizing a solution of the iridium compound, that is, an aqueous solution of hydrogen halide (for example, hydrochloric acid, hydrobromic acid, hydrofluoric acid) is used. Etc.) or a method of adding an alkali halide (eg, KCl, NaCl, KBr, NaBr, etc.). Instead of using water-soluble iridium, it is also possible to add and dissolve another iridium-doped silver halide grain during silver halide preparation.

The silver halide grains used in the present invention may further include cobalt, iron, nickel, chromium, palladium,
It may contain metal atoms such as platinum, gold, thallium, copper and lead. For compounds of cobalt, iron, chromium, and ruthenium, hexacyano metal complexes can be preferably used. Specific examples include ferricyanate ion, ferrocyanate ion, hexacyanocobaltate ion,
Examples include, but are not limited to, hexacyanochromate ions, hexacyanoruthenate ions, and the like. The metal complex in the silver halide may be contained uniformly, may be contained in the core portion at a high concentration, or may be contained in the shell portion at a high concentration, and there is no particular limitation. The metal is 1 × 10 ^-9 to 1 × 1 per mol of silver halide.
^0-4 moles are preferred. Further, in order to contain the above-mentioned metal, a metal salt in the form of a single salt, a double salt or a complex salt can be added at the time of preparing particles. 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, it may or may not be desalted.

The gold sensitizer used for sensitizing the silver halide emulsion used in the present invention to gold may have an oxidation number of +1 or +3, and gold which is usually used as a gold sensitizer may be used. Compounds can be used. Representative examples include chloroauric acid, potassium chloroaurate, auric trichloride, potassium auric thiocyanate,
Potassium iodooleate, tetracyano auric acid, ammonium aurothiocyanate, pyridyl trichlorogold and the like. Although the amount of the gold sensitizer to be added varies depending on various conditions, the standard is 10 ^-7 mol to 10 ^-3 mol, more preferably 10 ^-6 mol to 5 × 10 ^-4 mol, per mol of silver halide. It is. The silver halide emulsion used in the present invention is preferably used in combination with gold sensitization and another chemical sensitization. As other chemical sensitization methods, known methods such as a sulfur sensitization method, a selenium sensitization method, a tellurium sensitization method, and a noble metal sensitization method can be used. When used in combination with gold sensitization, for example, sulfur sensitization and gold sensitization, selenium sensitization and gold sensitization,
Sulfur sensitization method, selenium sensitization method, gold sensitization method, sulfur sensitization method, tellurium sensitization method, gold sensitization method, sulfur sensitization method, selenium sensitization method, tellurium sensitization method, gold sensitization method, etc. Is preferred.

The sulfur sensitization preferably used in the present invention is
Usually, a sulfur sensitizer is added and the emulsion is stirred at a high temperature of 40 ° C. or higher for a certain period of time. As the sulfur sensitizer, known compounds can be used.For example, in addition to sulfur compounds contained in gelatin, various sulfur compounds such as thiosulfates, thioureas, thiazoles, rhodanines and the like are used. be able to. Preferred sulfur compounds are thiosulfates and thiourea compounds. The amount of the sulfur sensitizer to be added varies under various conditions such as pH during chemical ripening, temperature, and the size of silver halide grains, but is preferably 10 ^-7 to 10 ^-2 mol per mol of silver halide. And more preferably 10 ^-5 to 10 ^-3 mol. As the selenium sensitizer used in the present invention, a known selenium compound can be used. That is, it is usually carried out by adding an unstable and / or non-unstable selenium compound and stirring the emulsion at a high temperature of 40 ° C. or higher for a certain time. Unstable selenium compounds include JP-B-44-15748 and JP-B-43-13.
No. 489, JP-A-4-25832, 4-109240, and 4
Compounds described in JP-A-324855 can be used.
In particular, the general formulas (VIII) and (I) in JP-A-4-324855
It is preferable to use the compound represented by X).

The tellurium sensitizer used in the present invention is a compound which forms silver telluride which is presumed to be a sensitizing nucleus on the surface or inside of silver halide grains. The formation rate of silver telluride in a silver halide emulsion is described in JP-A-5-3132.
The test can be performed by the method described in JP-A-84. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, P = Te Compounds having a bond, tellurocarboxylates, Te-organyltellurocarboxylates, di (poly) tellurides, tellurides, tellurols, telluroacetals,
Tellurosulfonates, compounds having a P-Te bond, containing T
e Heterocycles, tellurocarbonyl compounds, inorganic tellurium compounds, colloidal tellurium, and the like can be used. Specifically, U.S. Pat.Nos. 1,623,499 and 3,320,06
No. 9, Specification No. 3,772,031, British Patent No. 235,211
No. 1,121,496, No. 1,295,462, No. 1,396,696, Canadian Patent No. 800,958, Japanese Unexamined Patent Publication No. 4-204640, No. 3-53693, No. 3 -1315
No. 98, No. 4-129787, Journal of Chemical Society Chemical Communication (J. Chem. Soc. Chem. Commun.) 635 (1980), ibid 1102 (19)
79), ibid 645 (1979), Journal of Chemical Society Parkin Transaction (J. Chem. S.
oc.Perkin.Trans.) 1,2191 (1980), S. Patai
Hen, The Chemistr of Organic Selenium and Tellurium Campounds
y of Organic Serenium and Tellunium Compounds), Vo
Compounds described in l.1 (1986) and Vol.2 (1987) can be used. In particular, the general formula (I) in JP-A-5-313284
Compounds represented by I), (III) and (IV) are preferred.

The amount of the selenium and tellurium sensitizers used in the present invention, the silver halide grains to be used, but the chemical ripening condition and the like and, generally, per mol of silver halide 10 ^-8 to 10 ^-2 mol, Preferably about 10 ^-7 to 10 ^-3 mol is used. The conditions of the chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, the pAg is 6 to 11, preferably 7 to 10, and the temperature is 40 to 95 ° C, preferably 45 to 45 ° C. 85 ° C. In the silver halide emulsion used in the present invention, a cadmium salt, a sulfite, a lead salt, a thallium salt, and the like may coexist in the process of forming silver halide grains or physical ripening. In the present invention, reduction sensitization can be used. As specific compounds of the reduction sensitization method, in addition to ascorbic acid and thiourea dioxide, for example, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds and 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 silver halide emulsion used in the present invention may be added with a thiosulfonic acid compound according to the method described in EP 293,917. The silver halide emulsion used in the light-sensitive material of the present invention may be only one kind,
Two or more (for example, those having different average grain sizes, different halogen compositions, different crystal habits, and different chemical sensitization conditions) may be used in combination. The amount of the photosensitive silver halide used in the present invention is preferably 0.01 mol or more and 0.5 mol or less, more preferably 0.02 mol or more and 0.3 mol or less, and more preferably 0.02 mol or less and 0.3 mol or less per 1 mol of the organic silver salt.
Particularly preferred is 3 mol or more and 0.25 mol or less. Regarding the mixing method and the mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the prepared silver halide particles and organic silver salt are respectively mixed with a high-speed stirrer, a ball mill, a sand mill,
There is a method of mixing with a colloid mill, a vibration mill, a homogenizer, etc., or a method of preparing an organic silver salt by mixing photosensitive silver halide prepared at any timing during the preparation of the organic silver salt. There is no particular limitation as long as the effects of the present invention are sufficiently exhibited.

The photothermographic material of the present invention contains a nucleating agent.
The type of the nucleating agent used in the present invention is not particularly limited, but a substituted alkene derivative, a substituted isoxazole derivative and a specific acetal compound are preferably used.
The substituted alkene derivative represented by the formula (1), the substituted isoxazole derivative represented by the formula (2), and the specific acetal compound represented by the formula (3), which are preferably used in the present invention, will be described.

[0044]

Embedded image

In the equation (1), R¹, R^Two, R^ThreeEach
Each independently represents a hydrogen atom or a substituent, and Z represents an electron-withdrawing property.
Represents a group or a silyl group. In the formula (1), R¹And Z, R^Two
And R ^Three, R¹And R^TwoOr R^ThreeAnd Z are joined together
An annular structure may be formed. In the formula (2), R
^FourRepresents a substituent. In the equation (3), X and Y are respectively
A and B independently represent a hydrogen atom or a substituent,
Independently, an alkoxy group, an alkylthio group, an alkylamido
Group, aryloxy group, arylthio group, anilino
Group, heterocyclic oxy group, heterocyclic thio group, or hetero
Represents a ring amino group. In equation (3), X and Y or A
And B may combine with each other to form a cyclic structure
No.

The compound represented by the formula (1) will be described in detail.
I will tell. In the formula (1), R¹, R^Two, R^ThreeIs German
Represents a hydrogen atom or a substituent, and Z represents an electron-withdrawing group.
Or a silyl group. In the formula (1), R¹And Z, R^TwoAnd R
^Three, R¹And R^TwoOr R^ThreeAnd Z are linked together to form a ring
A structure may be formed. R¹, R^Two, R^ThreeIs a substituent
When represented, examples of the substituent include, for example, a halogen atom (F
Atom, chlorine atom, bromine atom or iodine atom),
Alkyl group (aralkyl group, cycloalkyl group, active
Alkenyl, alkynyl, ant
And heterocyclic groups (including N-substituted nitrogen-containing heterocyclic groups).
A) a heterocyclic group containing a quaternized nitrogen atom (eg,
Pyridinio group), acyl group, alkoxycarbonyl group,
Aryloxycarbonyl group, carbamoyl group, carbo
Xy groups or salts thereof, imino groups, imines substituted with N atoms
No group, thiocarbonyl group, sulfonylcarbamoyl group,
Acylcarbamoyl group, sulfamoylcarbamoyl
Group, carbazoyl group, oxalyl group, oxamoyl group,
Cyano group, thiocarbamoyl group, hydroxy group (or
Salt), alkoxy group (ethyleneoxy group or
(Including groups containing repeating propyleneoxy units)
Oxy group, heterocyclic oxy group, acyloxy group,
(Alkoxy or aryloxy) carbonyloxy
Group, carbamoyloxy group, sulfonyloxy group,
Mino group, (alkyl, aryl, or heterocyclic) amido
Group, acylamino group, sulfonamide group, ureido
Group, thioureido group, imide group, (alkoxy or
Aryloxy) carbonylamino group, sulfamoyl
Amino group, semicarbazide group, thiosemicarbazide group,
Hydrazino group, quaternary ammonium group, oxamoylamido
Group, (alkyl or aryl) sulfonylurea
Group, acylureido group, acylsulfamoylamino
Group, nitro group, mercapto group, (alkyl, aryl,
Or heterocycle) thio, acylthio, (alkyl
Or aryl) sulfonyl group, (alkyl or aryl
B) sulfinyl group, sulfo group or salt thereof, sulfa
Moyl group, acyl sulfamoyl group, sulfonyl sulf
Amoyl group or its salt, phosphoryl group, phosphoric amide
Or a group containing a phosphate ester structure, a silyl group,
And the like. These substituents are those substituents
May be further substituted.

The electron-withdrawing group represented by Z in the formula (1) is a substituent whose Hammett's substituent constant σp can take a positive value, specifically, a cyano group, an alkoxycarbonyl Group, aryloxycarbonyl group, carbamoyl group, imino group, imino group substituted with an N atom, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, halogen atom,
A perfluoroalkyl group, a perfluoroalkaneamide group, a sulfonamide group, an acyl group, a formyl group, a phosphoryl group, a carboxy group (or a salt thereof), a sulfo group (or a salt thereof), a heterocyclic group, an alkenyl group, an alkynyl group, Examples include an acyloxy group, an acylthio group, a sulfonyloxy group, and an aryl group substituted with these electron-withdrawing groups. Here, the heterocyclic group is a saturated or unsaturated heterocyclic group, for example, a pyridyl group, a quinolyl group,
Examples thereof include a pyrazinyl group, a quinoxalinyl group, a benzotriazolyl group, an imidazolyl group, a benzimidazolyl group, a hydantoin-1-yl group, a succinimide group, and a phthalimide group.

The electron-withdrawing group represented by Z in the formula (1) may further have a substituent. As the substituent, R ¹ , R ² , and R ^{3 in the} formula (1) may be substituted. The same substituents as the substituents that may be present when representing the substituents are exemplified. In the formula (1), R ¹ and Z, R ² and R ³ , R ¹ and R ² , or R ³ and Z
May combine with each other to form a cyclic structure,
The cyclic structure formed at this time is a non-aromatic carbon ring or a non-aromatic hetero ring.

Next, a preferred range of the compound represented by the formula (1) will be described. The silyl group represented by Z in the formula (1) is preferably a trimethylsilyl group, t
-Butyldimethylsilyl group, phenyldimethylsilyl group, triethylsilyl group, triisopropylsilyl group,
And a trimethylsilyldimethylsilyl group. The electron-withdrawing group represented by Z in the formula (1) is preferably a group having a total number of carbon atoms of 0 to 30, that is, a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a thiocarbonyl group, Imino group, imino group substituted with N atom, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, perfluoroalkyl group, acyl group, formyl group, phosphoryl group, acyloxy group, acylthio group, or any electron withdrawing A phenyl group substituted with a functional group, and more preferably,
Cyano group, alkoxycarbonyl group, carbamoyl group,
Imino group, sulfamoyl group, alkylsulfonyl group,
An arylsulfonyl group, an acyl group, a formyl group, a phosphoryl group, a trifluoromethyl group, or a phenyl group substituted with any electron-withdrawing group, and particularly preferably a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group , An imino group or a carbamoyl group. The group represented by Z in the formula (1) is more preferably an electron-withdrawing group.

In the formula (1), the substituent represented by R ¹ , R ² and R ³ is preferably a group having a total carbon number of 0 to 30, specifically, Z in the above formula (1). A group having the same meaning as the electron-withdrawing group represented, and an alkyl group, a hydroxy group (or a salt thereof), a mercapto group (or a salt thereof), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, Heterocyclic thio group, amino group, alkylamino group, arylamino group, heterocyclic amino group, ureido group, acylamino group, sulfonamide group,
Or a substituted or unsubstituted aryl group. Further, in the formula (1), R ¹ is preferably an electron-withdrawing group, an aryl group, an alkylthio group, an alkoxy group, an acylamino group, a hydrogen atom, or a silyl group.

When R ¹ represents an electron-withdrawing group, preferably the following groups having a total of 0 to 30 carbon atoms, ie, a cyano group, a nitro group, an acyl group, a formyl group, an alkoxycarbonyl group,
An aryloxycarbonyl group, a thiocarbonyl group, an imino group, an imino group substituted with an N atom, an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl group, a sulfamoyl group, a trifluoromethyl group, a phosphoryl group, a carboxy group (or a salt thereof), Or a saturated or unsaturated heterocyclic group, and a cyano group, an acyl group, a formyl group, an alkoxycarbonyl group, a carbamoyl group, an imino group, an imino group substituted with an N atom, a sulfamoyl group, a carboxy group (or a salt thereof) Or a saturated or unsaturated heterocyclic group. Particularly preferred are a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, and a saturated or unsaturated heterocyclic group. When R ¹ represents an aryl group, it is preferably a substituted or unsubstituted phenyl group having 6 to 30 carbon atoms in total, and examples of the substituent include arbitrary substituents. Is preferred. In formula (1), R ¹ more preferably represents an electron-withdrawing group or an aryl group.

In the formula (1), the substituents represented by R ² and R ³ are preferably, specifically, a group having the same meaning as the electron-withdrawing group represented by Z in the above-mentioned formula (1), or an alkyl group. , A hydroxy group (or a salt thereof), a mercapto group (or a salt thereof),
An alkoxy group, an aryloxy group, a heterocyclic oxy group,
Examples include an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group, an alkylamino group, an anilino group, a heterocyclic amino group, an acylamino group, and a substituted or unsubstituted phenyl group. In formula (1), R ² and R ³ are more preferably when one of them is a hydrogen atom and the other represents a substituent. The substituent is preferably an alkyl group, a hydroxy group (or a salt thereof), a mercapto group (or a salt thereof), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group. Group, alkylamino group, anilino group,
Heterocyclic amino group, acylamino group (particularly perfluoroalkaneamide group), sulfonamide group, substituted or unsubstituted phenyl group, or a heterocyclic group, more preferably a hydroxy group (or a salt thereof), a mercapto group ( Or a salt thereof), an alkoxy group, an aryloxy group,
Heterocyclic oxy group, alkylthio group, arylthio group,
A heterocyclic thio group or a heterocyclic group, particularly preferably a hydroxy group (or a salt thereof), an alkoxy group, or a heterocyclic group.

In the formula (1), Z and R ¹ , or R ²
It is also preferred that and R ³ form a cyclic structure. The cyclic structure formed in this case is a non-aromatic carbocyclic ring or a non-aromatic hetero ring, preferably a 5- to 7-membered cyclic structure having a total carbon number including a substituent of 1 to 4
0, more preferably 3 to 30. Among the compounds represented by the formula (1), one of the more preferable ones is that Z is a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group,
Represents an imino group or a carbamoyl group, R ¹ represents an electron-withdrawing group or an aryl group, one of R ^{2 and} R ³ is a hydrogen atom, and the other is a hydroxy group (or a salt thereof), a mercapto group (or Salt), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group,
A compound representing an arylthio group, a heterocyclic thio group, or a heterocyclic group. Further, one of the particularly preferable compounds represented by the formula (1) is that Z and R ^{1 form a} non-aromatic 5- to 7-membered cyclic structure, and R ² or R ³ Is a hydrogen atom and the other is a hydroxy group
(Or a salt thereof), a mercapto group (or a salt thereof), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, or a heterocyclic group. At this time, Z which forms a non-aromatic cyclic structure together with R ¹ includes an acyl group, a carbamoyl group, an oxycarbonyl group, a thiocarbonyl group,
A sulfonyl group and the like are preferable, and R ¹ is preferably an acyl group, a carbamoyl group, an oxycarbonyl group, a thiocarbonyl group, a sulfonyl group, an imino group, an imino group substituted by an N atom, an acylamino group, a carbonylthio group, and the like.

Next, the compound represented by the formula (2) will be described. In the formula (2), R ⁴ represents a substituent. As the substituent represented by R ⁴ , the same substituents as described for the substituents R ^{1 to} R ^{3 in} the formula (1) can be mentioned. The substituent represented by R ⁴ is preferably an electron-withdrawing group or an aryl group. When R ⁴ represents an electron-withdrawing group, preferably, the following groups having a total carbon number of 0 to 30, that is, a cyano group, a nitro group,
Acyl group, formyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, carbamoyl group, sulfamoyl group, trifluoromethyl group, phosphoryl group, imino group,
Or a saturated or unsaturated heterocyclic group, more preferably a cyano group, an acyl group, a formyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, or a heterocyclic group. Particularly preferred are a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, and a heterocyclic group. When R ⁴ represents an aryl group, it is preferably a substituted or unsubstituted phenyl group having a total of 6 to 30 carbon atoms, and the substituent is represented by R ¹ , R ² , R ³ of the formula (1).
When represents a substituent, the same as those described as the substituent can be mentioned. R ⁴ is particularly preferably a cyano group, an alkoxycarbonyl group, a carbamoyl group, a heterocyclic group, or a substituted or unsubstituted phenyl group;
Most preferably, they are a cyano group, a heterocyclic group, or an alkoxycarbonyl group.

Next, the compound represented by the formula (3) will be described in detail. In the formula (3), X and Y each independently represent a hydrogen atom or a substituent, and A and B each independently represent
Represents an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic thio group, a heterocyclic oxy group, or a heterocyclic amino group. X and Y or A and B may be bonded to each other to form a cyclic structure. As the substituents represented by X and Y in the formula (3), the same substituents as described for the substituents R ^{1 to} R ^{3 in} the formula (1) can be mentioned. Specifically, alkyl groups (including perfluoroalkyl groups, trichloromethyl groups, etc.), aryl groups, heterocyclic groups, halogen atoms, cyano groups, nitro groups, alkenyl groups, alkynyl groups, acyl groups, formyl groups, alkoxy groups Carbonyl group, aryloxycarbonyl group, imino group, imino group substituted with an N atom, carbamoyl group, thiocarbonyl group, acyloxy group, acylthio group, acylamino group,
Alkylsulfonyl, arylsulfonyl, sulfamoyl, phosphoryl, carboxy (or salt thereof), sulfo (or salt thereof), hydroxy (or salt thereof), mercapto (or salt thereof), alkoxy, aryl Oxy group, heterocyclic oxy group, alkylthio group, arylthio group, heterocyclic thio group, amino group,
Examples thereof include an alkylamino group, an anilino group, a heterocyclic amino group, and a silyl group.

These groups may further have a substituent. X and Y may be bonded to each other to form a cyclic structure, and the cyclic structure formed in this case may be a non-aromatic carbon ring or a non-aromatic hetero ring. . In formula (3), the substituents represented by X and Y are
It is preferably a group having 1 to 40 carbon atoms in total, more preferably a group having 1 to 30 carbon atoms in total, and is a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group,
Imino group, imino group substituted by N atom, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, perfluoroalkyl group,
Examples include an acyl group, a formyl group, a phosphoryl group, an acylamino group, an acyloxy group, an acylthio group, a heterocyclic group, an alkylthio group, an alkoxy group, and an aryl group.

In the formula (3), X and Y are more preferably cyano, nitro, alkoxycarbonyl, carbamoyl, acyl, formyl, acylthio, acylamino, thiocarbonyl, sulfamoyl, alkylsulfonyl. Group, an arylsulfonyl group, an imino group, an imino group substituted with an N atom, a phosphoryl group, a trifluoromethyl group, a heterocyclic group, a substituted phenyl group, and the like, and particularly preferably a cyano group, an alkoxycarbonyl group, and a carbamoyl group. Group, alkylsulfonyl group,
An arylsulfonyl group, an acyl group, an acylthio group, an acylamino group, a thiocarbonyl group, a formyl group, an imino group, an imino group substituted with an N atom, a heterocyclic group, or a phenyl group substituted with any electron-withdrawing group; is there. X
It is also preferable that Y and Y combine with each other to form a non-aromatic carbon ring or a non-aromatic hetero ring. At this time, the formed ring structure is preferably a 5- to 7-membered ring,
The total carbon number is preferably 1 to 40, more preferably 3 to 30. X and Y forming a cyclic structure are preferably an acyl group, a carbamoyl group, an oxycarbonyl group, a thiocarbonyl group, a sulfonyl group, an imino group, an imino group substituted by an N atom, an acylamino group, a carbonylthio group, and the like.

In the formula (3), A and B are each independently
Represents an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic thio group, a heterocyclic oxy group, or a heterocyclic amino group, which are bonded to each other to form a cyclic structure. You may. The group represented by A or B in the formula (3) is preferably a group having a total carbon number of 1 to 40, more preferably a group having a total carbon number of 1 to 40.
To 30 and may further have a substituent.
In the formula (3), A and B more preferably combine with each other to form a cyclic structure. The cyclic structure formed at this time is preferably a 5- to 7-membered non-aromatic hetero ring, and preferably has a total carbon number of 1 to 40, and more preferably 3 to 30. In this case, an example in which A and B are linked (-AB
-), For example, -O- (CH ₂ ) ₂ -O-, -O- (CH ₂ ) ₃ -O-,-
S- (CH ₂ ) ₂ -S-, -S- (CH ₂ ) ₃ -S-, -S-ph-S-, -N (CH ₃ )-(CH
₂ ) ₂ -O-, -N (CH ₃ )-(CH ₂ ) ₂ -S-, -O- (CH ₂ ) ₂ -S-, -O- (CH
₂ ) ₃ -S-, -N (CH ₃ ) -ph-O-, -N (CH ₃ ) -ph-S-, -N (ph)-(C
H ₂ ) ₂ -S- and so on.

The compounds represented by the formulas (1) to (3) used in the present invention may incorporate a adsorptive group that adsorbs to silver halide. Examples of such adsorptive groups include U.S. Pat. Nos. 4,385,108 and 4,459,3, such as alkylthio, arylthio, thiourea, thioamide, mercaptoheterocyclic, and triazole groups.
47, JP-A-59-195233, 5
JP-A-9-200231, JP-A-59-201045, JP-A-59-201046, and JP-A-59-202010
No. 7, No. 59-201048, No. 59-20
No. 1049, JP-A-61-170733, JP-A-61-270744, JP-A-62-948, JP-A-63-234244, JP-A-63-234245, and JP-A-63-234246. Group. These adsorbing groups to silver halide may be precursors. Examples of such a precursor include groups described in JP-A-2-285344.

The compounds represented by the formulas (1) to (3) used in the present invention have incorporated therein a ballast group or a polymer commonly used in immobile photographic additives such as couplers. May be. Particularly, those incorporating a ballast group are one of preferred examples of the present invention. The ballast group is a group having a carbon number of 8 or more, which is relatively inert to photographic properties, such as an alkyl group, an aralkyl group, an alkoxy group, a phenyl group, an alkylphenyl group,
It can be selected from phenoxy group, alkylphenoxy group and the like. Further, as the polymer, for example,
And those described in JP-A-100530. The compounds represented by the formulas (1) to (3) used in the present invention contain a cationic group (specifically, a group containing a quaternary ammonium group or a quaternized nitrogen atom). Nitrogen-containing heterocyclic group), a group containing a repeating unit of an ethyleneoxy group or a propyleneoxy group, an (alkyl, aryl, or heterocyclic) thio group, or a dissociable group (carboxy group, sulfo group) dissociable by a base , An acylsulfamoyl group, a carbamoylsulfamoyl group, etc.). Particularly, a group containing a group containing a repeating unit of an ethyleneoxy group or a propyleneoxy group, or a group containing an (alkyl, aryl, or heterocyclic) thio group is one of preferred examples of the present invention. Specific examples of these groups include, for example, JP-A-7-234471, JP-A-5-333466, and JP-A-6-190.
No. 32, JP-A-6-19031, JP-A-5-19031
No. 45761, U.S. Pat. No. 4,994,365,
U.S. Pat. No. 4,988,604, JP-A-3-2592
No. 40, JP-A-7-5610, JP-A-7-2
No. 44348, German Patent 4006032 and the like.

Next, specific examples of the compounds represented by the formulas (1) to (3) used in the present invention are shown below. However, the compounds used in the present invention are not limited to the following compounds.

[0062]

Embedded image

[0063]

Embedded image

[0064]

Embedded image

[0065]

Embedded image

[0066]

Embedded image

[0067]

Embedded image

[0068]

Embedded image

[0069]

Embedded image

[0070]

Embedded image

The compounds represented by the formulas (1) to (3) used in the present invention may be water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol) and ketones (acetone, acetone). Methylethylketone), dimethylformamide, dimethylsulfoxide,
It can be used by dissolving it in methylcellosolve or the like.
Also, by an already well-known emulsification dispersion method, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and an auxiliary solvent such as ethyl acetate or cyclohexanone are dissolved and mechanically emulsified and dispersed. An object can be prepared and used. Alternatively, a compound powder can be dispersed in a suitable solvent such as water by a ball mill, a colloid mill, or ultrasonic waves by a method known as a solid dispersion method and used.

The compounds represented by the formulas (1) to (3) used in the present invention are preferably added to an image forming layer or added to a layer other than the image forming layer to be diffused into the image forming layer. You may. The added layer may be any layer as long as it is a layer on the image forming layer side with respect to the support, but is preferably an image forming layer or a layer adjacent thereto. Formula used in the present invention
The amount of the compound represented by formulas (1) to (3) is preferably from 1 × 10 ⁻⁶ to 1 mol per mol of silver, preferably from 1 × 10 ^{−5 to} 5 ×.
10 ^-1 mol is more preferable, and 2 x 10 ^-5 to 2 x 10 ^-1 mol is most preferable. The compounds represented by the formulas (1) to (3) can be easily synthesized by known methods. For example, US Pat. No. 5,545,515 and US Pat.
No. 5339, U.S. Pat.No. 5,654,130,
International Publication WO97 / 34196 or Japanese Patent Application No. Hei 9
The compound can be synthesized with reference to the method described in Japanese Patent Application No. 309813 and Japanese Patent Application No. 9-272002.

The compounds represented by formulas (1) to (3) used in the present invention may be used alone or in combination of two or more. Also, in addition to the above, US Pat. No. 5,545,515.
No. 5,635,339, U.S. Pat. No. 5,654,130, International Publication WO 97/34.
No. 196, U.S. Pat. No. 5,686,228, or compounds disclosed in Japanese Patent Application Nos. 9-228881, 9-273935 and 9-30.
No. 9813, Japanese Patent Application No. 9-296174,
Japanese Patent Application No. 9-282564, Japanese Patent Application No. 9-2720
Compounds described in Japanese Patent Application No. 02, Japanese Patent Application No. 9-272003 and Japanese Patent Application No. 9-332388 may be used in combination.

In the present invention, a hydrazine derivative can be used as a nucleating agent, but the above nucleating agent and a hydrazine derivative may be used in combination. In that case, the following hydrazine derivatives are preferably used. The hydrazine derivative used in the present invention can also be synthesized by various methods described in the following patents. 6-77138
And the compounds represented by (Chemical Formula 1) described in JP-A-2003-254, specifically, the compounds described on pages 3 and 4 of the same. 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 publication. JP 6-23
Compounds represented by the general formulas (4), (5) and (6) described in JP-A-0497, specifically,
Page, compound 4-1 to compound 4-10 described on page 26, compound 5-1 to 5-42 described on page 28 to page 36, and compound 6-1 to compound 6 described on page 39, page 40 -7. Compounds represented by general formulas (1) and (2) described in JP-A-6-289520, specifically, compounds 1-1) to 1-1-1 described on pages 5 to 7 of the same publication. 17)
And 2-1). Compounds represented by (Chemical Formula 2) and (Chemical Formula 3) described in JP-A-6-313936, specifically, compounds described on pages 6 to 19 of the same publication. 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. A compound represented by the general formula (I) described in JP-A-7-5610, specifically, from page 5 to 10
Compounds I-1 to I-38 described on page. Compounds represented by general formula (II) described in JP-A-7-77783, specifically, compounds II-1 to II-102 described on pages 10 to 27 of the same. JP-A-7-
General formula (H) and general formula (H
Compounds represented by a), specifically, compounds H-1 to H-44 described on pages 8 to 15 of the publication. A compound described in JP-A-9-22082, which has an anionic group or a nonionic group which forms an intramolecular hydrogen bond with a hydrogen atom of hydrazine in the vicinity of a hydrazine group. ), General formula (B), general formula (C), general formula (D),
Compounds represented by the general formulas (E) and (F), specifically, compounds N-1 to N-30 described in the publication. JP-A-9-2
No. 2082, compounds represented by the general formula (1), specifically, compounds D-1 to D-55 described in the publication.

Further, “Known Techniques (1 to
207) ”(published by Aztec) on pages 25 to 34. JP-A-62-86354 (pages 6 to 7)
Compounds D-2 and D-39). The hydrazine derivative used in the present invention may be a suitable 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, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and an auxiliary solvent such as ethyl acetate or cyclohexanone are dissolved 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.

The hydrazine derivative used in the present invention is
The layer on the image forming layer side with respect to the support, that is, the image forming layer
Or to any layer of the other binder layer on this layer side
Good, but the image forming layer or binder adjacent to it
Preferably, it is added to the layer. Hyd used in the present invention
The amount of the azine derivative added was 1 × 10^-6~ 1 × 1
0^-2Mole is preferred, 1 × 10^-Five~ 5 × 10^-3Mole is more preferred
2 × 10^-Five~ 5 × 10 ^-3Molar is most preferred. Also book
The invention relates to the above-mentioned nucleating agent for forming ultra-high contrast images.
A hardening accelerator can be used in combination. For example, US
No. 5,545,505, the amine compound described in the specification, specifically
The hydroxa described in AM-1 to AM-5, 5,545,507
Humic acids, specifically described in HA-1 to HA-11 and 5,545,507
Acrylonitrile described above, specifically CN-1 to CN-1
3, the hydrazine compound according to 5,558,983, specifically,
CA-1 to CA-6, described in JP-A-9-297368
Onium salts, specifically A-1 to A-42, B-1 to B-
27, C-1 to C-14 and the like can be used. these
The synthesis method, addition method, amount, etc.
Perform as described in each of the cited patent specifications
be able to.

In the present invention, an acid or a salt thereof formed by hydration of diphosphorus pentoxide is preferably used in combination with a nucleating agent. Acids or salts thereof formed by hydration of diphosphorus pentoxide include metaphosphoric acid (salt), pyrophosphoric acid (salt), orthophosphoric acid (salt), triphosphoric acid (salt), tetraphosphoric acid (salt), hexametaline Acids (salts); Particularly preferred acids or salts thereof formed by hydration of diphosphorus pentoxide include orthophosphoric acid (salt) and hexametaphosphoric acid (salt),
Specific salts include sodium orthophosphate, sodium dihydrogen orthophosphate, sodium hexametaphosphate,
Examples include ammonium hexametaphosphate. The acid or salt thereof formed by hydration of diphosphorus pentoxide, which can be preferably used in the present invention, is preferably added to the image forming layer or the binder layer adjacent thereto from the viewpoint that the desired effect is exhibited in a small amount. . The amount of the acid or salt thereof formed by hydration of diphosphorus pentoxide used in the present invention (the coating amount per 1 m ^{2 of the} light-sensitive material) may be a desired amount in accordance with the performance such as sensitivity and fog. -500 mg / m < ² > is preferable, and 0.5-100 mg / m < ² > is more preferable.

The photothermographic material of the present invention preferably contains a reducing agent for an organic silver salt. 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 preferably contained in an amount of 5 to 50 mol%, more preferably 10 to 40 mol%, per 1 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. 49-1
No. 15540, No. 50-14334, No. 50-36110,
No. 50-147711, No. 51-32632, No. 51-1023721
JP-A-51-32324, JP-A-51-51933 and JP-A-52-8
No. 4727, No. 55-108654, No. 56-146133,
No. 57-82828, No. 57-82829, JP-A-6-3793, U.S. Pat.No. 3,679,426, No. 3,751,252, No. 3,751,255, No. 3,761,270, No.
3,782,949, 3,839,048, 3,928,68
No. 6,5,464,738, German Patent 2321328, European Patent 692732, and the like. 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 and ascorbic acid, such as a combination of -β-phenylhydrazine and ascorbic acid;
Combinations of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine (eg, hydroquinone and bis (ethoxyethyl) hydroxylamine, piperidinohexose reductone or formyl-4
-Methylphenylhydrazine, etc.); hydroxamic acids such as phenylhydroxamic acid, p-hydroxyphenylhydroxamic acid and β-alinine hydroxamic acid; combinations of azine with sulfonamidophenol (eg, phenothiazine and 2,6-dichloro- Α-cyanophenylacetic acid derivatives such as ethyl-α-cyano-2-methylphenylacetate and ethyl-α-cyanophenylacetate; 2,2′-dihydroxy-1,1′-binaphthyl , 6,6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl and bis (2-hydroxy-1-
Bis-β-naphthol, as exemplified by naphthyl) methane; bis-β-naphthol and 1,3-dihydroxybenzene derivatives (eg, 2,4-dihydroxybenzophenone or
2 ', 4'-dihydroxyacetophenone); 3-
5-pyrazolones, such as methyl-1-phenyl-5-pyrazolone; reductones as exemplified by dimethylaminohexose reductone, anhydrodihydroaminohexose reductone and anhydrodihydropiperidone hexose reductone; 2 Sulfonamide phenol reducing agents such as 2,6-dichloro-4-benzenesulfonamidophenol and p-benzenesulfonamidophenol; 2-phenylindane-1,3-dione and the like; 2,2-dimethyl-7-t-butyl- Chromans such as 6-hydroxychroman; 1,4-dihydropyridines such as 2,6-dimethoxy-3,5-dicarbethoxy-1,4-dihydropyridine; bisphenols (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.); ascorbin Acid derivatives (eg, 1-ascorbyl palmitate, ascorbyl stearate, etc.); and aldehydes and ketones such as benzyl and biacetyl;
Pyrazolidone and certain indan-1,3-diones; chromanol (such as tocopherol). Particularly preferred reducing agents are bisphenol and chromanol.

The reducing agent used in 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.

When an additive known as a “toning agent” for improving an image is contained, the optical density may be increased. Toning agents may also be advantageous in forming black silver images. The toning agent is preferably contained in an amount of 0.1 to 50% (mole) per mole of silver on the surface having the image forming layer, and more preferably 0.5 to 20% (mole).
Further, the toning agent may be a so-called precursor which is derivatized so as to have a function effectively only during development. In the photothermographic material using an organic silver salt, a wide range of color toning agents are disclosed in JP-A-46-6077, JP-A-47-10282, and JP-A-49-5019.
JP-A-49-5020, JP-A-49-91215, JP-A-49-91
No. 215, No. 50-2524, No. 50-32927, No. 50
-67132, 50-67641, 50-114217, 51-3223, 51-27923, 52-14788
No. 52-99813, No. 53-1020, No. 53-76
No. 020, No. 54-156524, No. 54-156525,
No. 61-183642, JP-A-4-56848, JP-B-49-1
No. 0727, 54-20333, U.S. Pat.No.3,080,254
No. 3,446,648, 3,782,941, 4,123,282, 4,510,236, British Patent No. 1380795, Belgian Patent No. 841910, and the like. Examples of toning agents are phthalimide and N-hydroxyphthalimide; succinimide, pyrazolin-5-one, and quinazolinone, 3-phenyl-
Cyclic imides such as 2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 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-
Mercaptans exemplified by 4,5-diphenyl-1,2,4-triazole and 2,5-dimercapto-1,3,4-thiadiazole; N- (aminomethyl) aryldicarboximides;
(E.g., (N, N-dimethylaminomethyl) phthalimide and N, N- (dimethylaminomethyl) -naphthalene-2,3-dicarboximide); 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, phthalazinone Derivatives or metal salts, or derivatives such as 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone and 2,3-dihydro-1,4-phthalazinedione; phthalazinone and phthalate Combination with acid derivatives such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride; phthalazine, phthalazine derivatives
(E.g., 4- (1-naphthyl) phthalazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine, 6-iso-butylphthalazine, 6-tert-butylphthalazine, 5,7-dimethylphthalazine, And metal salts; combinations of phthalazine and its derivatives with phthalic acid derivatives (eg, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride) A quinazolinedione, benzoxazine or naphthoxazine derivative; a rhodium complex which functions not only as a color tone regulator but also in situ as a source of halide ions for silver halide formation, such as ammonium hexachlororhodate (III), bromide Rhodium, rhodium nitrate and potassium hexachlororhodate (III);
Inorganic peroxides and persulfates, for example, ammonium disulfide and hydrogen peroxide; 1,3-benzoxazine-
Benzoxazine-2,4-diones such as 2,4-dione, 8-methyl-1,3-benzoxazine-2,4-dione and 6-nitro-1,3-benzoxazine-2,4-dione; Pyrimidine and asymmetric-triazines (e.g., 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 tone agent used in the present invention may be added by any method such as a solution, a powder, and a solid fine particle dispersion. The dispersion of the solid fine particles is carried out by a known means for making fine (for example, a ball mill, a vibration ball mill, a sand mill, a colloid mill, a jet mill, a roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used. The surface pH of the photothermographic material of the present invention before the heat development is preferably 6 or less from the viewpoint of reducing fogging during storage, particularly 5.5 or less, more preferably 5.3 or less. The lower limit is not particularly limited, but is generally about 3. The adjustment of the film surface pH is preferably performed using an organic acid such as a phthalic acid derivative, a nonvolatile acid such as sulfuric acid, or a volatile base such as ammonia from the viewpoint of reducing the film surface pH. In particular, ammonia is preferable for achieving a low film surface pH since ammonia is easily volatilized and can be removed before the application step and the heat development.

The film surface pH of the photothermographic material of the present invention
When measuring the photothermographic material 2.5 mm × 2.5 cm before the heat development processing, the film was folded into a boat shape, 300 μl of distilled water was dropped on the image forming layer side, and the solution was allowed to stand for 30 minutes. It is preferable to measure the dropped solution for 1 minute with a pH BOY-P2 (a semiconductor type pH meter manufactured by Shindengen Kogyo Co., Ltd.).

As the binder used in the present invention, it is preferable to use the polymer latex described below. It is preferable that at least one of the image forming layers containing the photosensitive silver halide of the photothermographic material of the present invention is an image forming layer using the polymer latex described below as 50% by weight or more of the total binder ( Hereinafter, this image forming layer is referred to as "image forming layer in the present invention", and the polymer latex used as the binder is referred to as "polymer latex used in the present invention".) Further, the polymer latex may be used not only for the image forming layer but also for the protective layer and the back layer. It is preferable to use a polymer latex also for the layer. However, the "polymer latex" referred to here is a water-insoluble hydrophobic polymer dispersed as fine particles in a water-soluble dispersion medium. The dispersion state is such that the polymer is emulsified in a dispersion medium, emulsion-polymerized, micelle-dispersed, or partially dispersed in polymer molecules and molecular chains themselves are molecularly dispersed. Any of them may be used. The polymer latex used in the present invention is described in "Synthetic Resin Emulsion" (edited by Tadashi Okuda and Hiroshi Inagaki, published by the Society of Polymer Publishing (1978)), "Application of Synthetic Latex (edited by Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara) , Published by Kobunshi Kankokai (1993)), "Synthesis of Synthetic Latex (Souichi Muroi, published by Kobunshi Kankokai (1970))" and the like. The average particle size of the dispersed particles is 1 to 50,000 nm, more preferably
A range of about 5 to 1000 nm is preferable. There is no particular limitation on the particle size distribution of the dispersed particles, and those having a wide particle size distribution or those having a monodispersed particle size distribution may be used.

The polymer latex used in the present invention may be a so-called core / shell type latex other than the polymer latex having a normal uniform structure. In this case, it may be preferable to change the glass transition temperature of the core and the shell. Glass transition temperature (Tg) of polymer of polymer latex preferably used as a binder in the present invention
The preferred ranges differ between the protective layer, the back layer and the image forming layer. In the image forming layer, the temperature is preferably -30 to 40 ° C. in order to promote diffusion of the photographically useful material during thermal development.
When used for the protective layer or the back layer, a glass transition temperature of 25 to 70 ° C. is preferable for contacting various devices. The minimum film formation temperature (MFT) of the polymer latex used in the present invention is -30.
C. to 90.degree. C., more preferably about 0.degree.
A film-forming auxiliary may be added to control the minimum film-forming temperature. The film-forming aid is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of the polymer latex, also called a plasticizer, and is described in, for example, `` Synthesis of Synthetic Latex (Souichi Muroi, published by Polymer Publishing Association (1970) )"It is described in.

The polymer used in the polymer latex used in the present invention includes acrylic resin, vinyl acetate resin, polyester resin, polyurethane resin, rubber resin, vinyl chloride resin, vinylidene chloride resin, polyolefin resin, or a copolymer thereof. and so on. The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of the polymer is preferably from 5000 to 100000, more preferably from about 10,000 to 100,000 in number average molecular weight. If the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and if it is too large, the film-forming properties are poor, which is not preferable. Specific examples of the polymer latex used as a binder for the image forming layer of the photothermographic material of the present invention include the following. Latex of methyl methacrylate / ethyl acrylate / methacrylic acid copolymer, latex of methyl methacrylate / 2-ethylhexyl acrylate / styrene / acrylic acid copolymer, latex of styrene / butadiene / acrylic acid copolymer, latex of styrene / butadiene / divinylbenzene / methacrylic acid copolymer Latex of methyl methacrylate / vinyl chloride / acrylic acid copolymer, latex of vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer, and the like. Such polymers are also commercially available,
The following polymers can be used. For example, as an example of an acrylic resin, Sebian A-4635,46583,4601 (all manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 82
Polyester resins such as 0, 857 (all manufactured by Nippon Zeon Co., Ltd.) include FINETEX ES650, 611, 675, 850 (all manufactured by Dainippon Ink and Chemicals, Inc.), WD-size, WMS (all manufactured by Eastman Chemical Co., Ltd.) HYDRAN for polyurethane resin
LACSTAR 7310K, 3307B, 4700 are rubber-based resins such as AP10, 20, 30, 40 (all manufactured by Dainippon Ink and Chemicals, Inc.)
H, 7132C (all manufactured by Dainippon Ink and Chemicals, Inc.), Nipol Lx4
16, 410, 438C, 2507, (Nippon Zeon Co., Ltd.), etc., vinyl chloride resins such as G351, G576 (Nippon Zeon Co., Ltd.), etc., vinylidene chloride resins L502, L
513 (manufactured by Asahi Kasei Corporation), Aron D7020, D504, D5
071 (Mitsui Toatsu Co., Ltd.) and other olefin resins include Chemipearl S120 and SA100 (Mitsui Petrochemical Co., Ltd.)
And the like. These polymers may be used alone or as a blend of two or more as necessary.

In the image forming layer in the present invention, the above polymer latex is preferably used as 50% by weight or more of the whole binder, and more preferably 70% by weight or more of the above polymer latex. In the image forming layer in the present invention, if necessary, 50% by weight of all binders
%, A hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, or hydroxypropylmethylcellulose may be added. The amount of the hydrophilic polymer to be added is preferably 30% by weight or less, more preferably 15% by weight or less of the total binder in the image forming layer. The image forming layer in the invention is preferably prepared by applying an aqueous coating solution and then drying. However, the "water system" mentioned here
This means that 60% by weight or more of the solvent (dispersion medium) of the coating liquid is water. The components of the coating solution other than water are methyl alcohol,
Ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide,
A water-miscible organic solvent such as ethyl acetate can be used. Specific examples of the solvent composition include the following. Water / methanol = 90/10, water / methanol = 70 /
30, water / ethanol = 90/10, water / isopropanol = 90
/ 10, water / dimethylformamide = 95/5, water / methanol / dimethylformamide = 80/15/5, water / methanol / dimethylformamide = 90/5/5. (However, figures are weight
Represents%. ) The total binder amount of the image forming layer in the present invention is 0.2 to 30 g.
/ M ² , more preferably in the range of 1 to 15 g / m ² . A crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added to the image forming layer in the invention.

As the sensitizing dye used in the present invention, any sensitizing 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 holopolar cyanine 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 (August 1979)
p.437) or in the literature cited. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of the light source of various laser imagers, scanners, imagesetters and plate making cameras can be advantageously selected.

As an example of spectral sensitization to red light, He-Ne
For so-called red light sources such as lasers, red semiconductor lasers and LEDs, the I-1 described in JP-A-54-18726 is used.
To I-38, I-1 described in JP-A-6-75322.
To I-35 and the compounds of I-1 to I-34 described in JP-A-7-287338, the dyes 1 to 20 described in JP-B-55-39818, and JP-A-62-284343. I-1 described in
To I-37 and the compounds of I-1 to I-34 described in JP-A-7-287338 are advantageously selected. 750
For semiconductor laser light sources in the wavelength range of ~ 1400 nm,
A variety of known dyes, including cyanine, merocyanine, styryl, hemicyanine, oxonol, hemioxonol, and xanthene dyes, can be spectrally sensitized favorably. Useful cyanine dyes are, for example, cyanine dyes having a basic nucleus, such as a thiazoline nucleus, an oxazoline nucleus, a pyrroline nucleus, a pyridine nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus and an imidazole nucleus. 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-mentioned cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective.
For example, U.S. Pat. -52387, JP-A-5-341432, JP-A-6-94781, and 6-301141.

Particularly preferred as the structure of the dye used in the present invention is a cyanine dye having a thioether bond-containing substituent (for example, JP-A Nos. 62-58239 and 3-1).
No. 38638, No. 3-38642, No. 4-255840,
No. 5-72659, No. 5-72661, No. 6-222491, No. 2-230506, No. 6-258757, No. 6-317868
JP-A-6-324425, JP-T-Hei 7-500926, the dye described in U.S. Pat.No. 5,541,054), a dye having a carboxylic acid group (for example, JP-A-3-163440, No. 6-301141, dyes described in U.S. Pat.No. 5,441,899), merocyanine dyes, polynuclear merocyanine dyes and polynuclear cyanine dyes (JP-A-47-6329 and JP-A-49-1).
No. 05524, No. 51-127719, No. 52-80829,
JP 54-61517, JP 59-214846, JP 60-6750, JP 63-159841, JP-A 6-35109, JP 6-59
Dyes described in JP-A-381, JP-A-7-146537, JP-A-7-146537, JP-T-55-50111, British Patent 1,467,638, and US Pat. No. 5,281,515.

The dyes forming the J-band are described in US Pat.
No. 6,019,036, which can be preferably used in the present invention. These sensitizing dyes may be used alone.
It may be used in combination of more than one kind. Combinations of sensitizing dyes are often used, especially for supersensitization. In addition to 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
Research Disclosure Volume 176, 17643 (Issued December 1978) No. 23
Paragraph J on page IV, or JP-B-49-25500, 43-4933
And JP-A-59-19032 and JP-A-59-192242.

The sensitizing dyes may be added to the silver halide emulsion by dispersing them directly in the emulsion or by adding water, methanol, ethanol, propanol, acetone, methylcellosolve, 2,2, 3,3-tetrafluoropropanol, 2,2,2-trifluoroethanol, 3-methoxy
It may be added to the emulsion by dissolving it in a solvent such as 1-propanol, 3-methoxy-1-butanol, 1-methoxy-2-propanol, N, N-dimethylformamide, alone or in a mixed solvent. Further, as disclosed in U.S. Pat.No. 3,469,987, a dye is dissolved in a volatile organic solvent, this solution is dispersed in water or a hydrophilic colloid, and this dispersion is added to the emulsion. Japanese Patent Publication No. 44-23389,
As disclosed in 44-27555 and 57-22091, a dye is dissolved in an acid, and this solution is added to the emulsion, or an acid or base is allowed to coexist to form an aqueous solution into the emulsion. Addition method, U.S. Pat.No. 3,822,135, 4,006,0
A method of adding an aqueous solution or a colloidal dispersion in the presence of a surfactant to an emulsion as disclosed in the specification of JP-A-53-102733 and JP-A-58-1051.
No. 41, a method of directly dispersing a dye in a hydrophilic colloid as disclosed in JP-A No. 41, and adding the dispersion to an emulsion, as disclosed in JP-A-51-74624, a red shift A method of dissolving a dye using a compound to be dissolved and adding this solution to an emulsion can also be used. Also, ultrasonic waves can be used for dissolution.

The sensitizing dye may be added to the silver halide emulsion at any stage of the emulsion preparation which has been found to be useful. US Patent
2,735,766, 3,628,960, 4,183,75
No. 6,225,666, JP-A-58-184142, JP-A-60-196749, and the like, as disclosed in the specifications of silver halide grains, and / or desalination. A period before the chemical ripening, during the desalting step and / or after the desalting and before the start of the chemical ripening, as disclosed in the specification such as JP-A-58-113920. It may be added at any stage in the process, during the middle stage, after the chemical ripening and before the coating, before the emulsion is coated. In addition, U.S. Pat.
As disclosed in the specification such as 8-7629, the same compound is used alone or in combination with a compound having a different structure, for example, divided into a particle forming step and a chemical ripening step or after completion of chemical ripening. Alternatively, they may be added separately before or after chemical ripening 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 amount of the sensitizing dye used in the present invention may be a desired amount in accordance with the performance such as sensitivity and fog, but may be 10 ^-6 per mol of silver halide in the photosensitive layer.
11 mol is preferable, and 10 ^-4 to 10 ^-1 mol is more preferable.

The silver halide emulsion according to the invention or /
And organic silver salts can be further protected against the formation of additional fog by antifoggants, stabilizers and stabilizer precursors, and stabilized against reduced sensitivity during storage in inventory. Suitable antifoggants, stabilizers and stabilizer precursors that can be used alone or in combination are described in U.S. Patent Nos. 2,131,038 and 2,694,716.
Thiazonium salt described in U.S. Pat.No. 2,886,43
No. 7 and 2,444,605, azaindene, U.S. Pat.No. 2,728,663, mercury salt, U.S. Pat. Sulfocatechol, oximes described in GB 623,448, nitrones, nitroindazoles, U.S. Pat.
No. 405, polyvalent metal salt, U.S. Pat.No. 3,220,839
Thiuronium salt described in US Pat.
Palladium, platinum and gold salts described in 2,566,263 and 2,597,915, U.S. Pat.No.4,108,665
No. 4,442,202, halogenated organic compounds described in U.S. Pat.Nos. 4,128,557 and 4,137,079, 4,138,365 and 4,459,350, There are phosphorus compounds described in U.S. Pat. No. 4,411,985 and the like.

Antifoggants preferably used in the present invention
Is an organic halide, for example, JP-A-50-119624
No. 50-120328, No. 51-121332, No. 54
-58022, 56-70543, 56-99335,
JP 59-90842, JP 61-129642, JP 62-129845
JP, JP-A-6-208191, JP-A-7-5621, JP-A-7-27
No. 81, 8-15809, U.S. Pat.No. 5,340,712
Detailed specifications, 5,369,000 and 5,464,737
Compounds as indicated. Used in the present invention
Antifoggants include solutions, powders, solid fine particle dispersions, etc.
It may be added by any method. Dispersion of solid fine particles is known
Means of refinement (for example, ball mill, vibrating ball mill,
Sand mill, colloid mill, jet mill, roller mill
Etc.). Also, when dispersing solid fine particles,
Spray aids may be used. Necessary to carry out the invention
No mercury (II) salt was added to the emulsion layer as an antifoggant.
May be advantageous. Mercury preferred for this purpose
(II) Salts are mercury acetate and mercury bromide. Used in the present invention
The amount of mercury used was 1 mole of applied silver.
More preferably 1 × 10^-9Mol ~ 1 x 10^-3Mol, even more preferred
1x10 ^-8Mol ~ 1 x 10^-FourRange of moles.

The photothermographic material of the present invention may contain benzoic acids for the purpose of increasing the sensitivity and preventing fog. The benzoic acids used in the present invention may be any benzoic acid derivative, and examples of preferred structures include U.S. Pat.
No. 939, No. 4,152,160, JP-A-9-32
Nos. 9863, 9-329864 and 9-2
Compounds described in JP-A-81637 are exemplified. The benzoic acid may be added to any part of the light-sensitive material, but it is preferably added to the layer having the photosensitive layer, more preferably to the organic silver salt-containing layer. The benzoic acid may be added in any step of the preparation of the coating solution, and when it is added to the organic silver salt-containing layer, any step from the preparation of the organic silver salt to the preparation of the coating solution may be performed. To just before application. The benzoic acid 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 may be added in any amount, but is preferably from 1 × 10 ⁻⁶ mol to 2 mol, more preferably from 1 × 10 ⁻³ mol to 0.5 mol, per mol of silver.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained in order to control development by suppressing or accelerating development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. be able to. When a mercapto compound is used in the present invention, any structure may be used, but Ar-SM, Ar-S
Those represented by -S-Ar are preferred. In the formula, M is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring group or a condensed aromatic ring group having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably, the heteroaromatic ring in these groups is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole,
Benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, carbazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring includes, for example, halogens (e.g., Br and Cl), hydroxy, amino, carboxy, alkyl (e.g., those having one or more carbon atoms, preferably 1-4 carbon atoms), alkoxy ( For example, one or more carbon atoms, preferably 1-4
May have one selected from the group consisting of substituents consisting of those having 2 carbon atoms) and aryl (which may have a substituent). 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-Hydrogyrosine-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-diamino-2-mercaptopyrimidine, 2-mercapto-4-methylpyrimidine hydrochloride, 3-mercapto-5-phenyl- 1,2,4-triazole, 1-phenyl-5-mercaptotetrazole, 3-
Sodium (5-mercaptotetrazole) -benzenesulfonate, N-methyl-N '-[3- (5-mercaptotetrazolyl) phenyl] urea, 2-mercapto-4-phenyloxazole, N- [3- (mercapto Acetylamino) propyl]
Although carbazole etc. are mentioned, the present invention is not limited to these.

The addition amount of these mercapto compounds is preferably in the range of 0.0001 to 1.0 mol per mol of silver in the emulsion layer, more preferably 0.001 to 0.1 mol per mol of silver.
The amount is 3 moles. In the image forming layer (preferably the photosensitive layer) in the present invention, a polyhydric alcohol (for example, glycerin and diol of the type described in U.S. Pat. No. 2,960,404) may be used as a plasticizer and a lubricant.
Fatty acids or esters described in 2,588,765 and 3,121,060, and silicone resins described in British Patent No. 955,061 can be used.

In the present invention, it is preferable to provide a protective layer on the image forming layer. As a binder for the protective layer, as described above, a latex of a polymer having a glass transition temperature of 25 ° C. or more and 70 ° C. or less is used. Is preferred. In this case, at least 50% by weight of the total binder of the protective layer, preferably
It is preferable to use the above-mentioned polymer latex at 70% by weight or more. In the present invention, it is preferable to provide at least one such protective layer. The binder configuration and coating method of such a protective layer are the same as those of the image forming layer. As the polymer latex for the protective layer, acrylic, styrene, acryl / styrene, vinyl chloride, and vinylidene chloride polymer latexes are preferably used. Specifically, acrylic resin-based VONCORT R337
0, 4280, Nipol Lx857, methyl (meth) acrylate / 2-ethylhexyl (meth) acrylate / hydroxyethyl (meth) acrylate / styrene / (meth) acrylic acid copolymer, Nipol G576 vinyl chloride resin, Alon D5071 vinylidene chloride resin Is preferably used. The total binder amount for the protective layer used in the present invention is 0.
The range is ^{2 to} 5.0 g / m ² , more preferably 0.5 to 4.0 g / m ² .

As the surface protective layer in the present invention, any anti-adhesion material may be used. Examples of anti-adhesion materials include wax, silica particles, styrene-containing elastomeric block copolymers (e.g., styrene-butadiene-styrene, styrene-isoprene-styrene), cellulose acetate, cellulose acetate butyrate, cellulose propionate and the like. And mixtures. Further, a crosslinking agent for crosslinking and a surfactant for improving coating properties may be added to the surface protective layer. U.S. Pat.Nos. 3,253,921, 2,274,782, and
Light absorbing substances and filter dyes such as those described in 2,527,583 and 2,956,879 can be used. Also, for example, U.S. Pat.
The dye can be mordanted as described in US Pat. The amount of the filter dye used is preferably such that the absorbance at the exposure wavelength is 0.1 to 3, and particularly preferably 0.2 to 1.5.

Various dyes and pigments can be used in the photosensitive layer of the present invention from the viewpoint of improving color tone and preventing irradiation. Dyes and pigments used in the photosensitive layer may be any, for example, pigments and dyes described in the color index, specifically, pyrazoloazole dye,
Organic pigments such as anthraquinone dyes, azo dyes, azomethine dyes, oxonol dyes, carbocyanine dyes, styryl dyes, triphenylmethane dyes, indoaniline dyes, indophenol dyes, and phthalocyanines, and inorganic pigments. Preferred dyes used in the present invention are anthraquinone dyes (for example,
-341441, compounds 1 to 9, described in JP-A-5-165147, compounds 3-6 to 18 and 3-23 to 38, etc.), azomethine dyes (compounds 17 to described in JP-A-5-341441). 47), indoaniline dyes (e.g., compounds 11 to 19 described in JP-A-5-289227, compound 47 described in JP-A-5-341441, compounds 2-10 to 11 described in JP-A-5-165147). And azo dyes (compounds described in JP-A-5-341441)
10-16). 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 depending on the desired absorption amount, but it is generally preferable to use them in a range of 1 × 10 ⁻⁶ g to 1 g per 1 m ² of the photographic material. The photothermographic material of the present invention may be a so-called single-sided photosensitive material having at least one photosensitive layer containing a silver halide emulsion on one side of a support and a back layer on the other side. preferable.

In the present invention, the back layer preferably has a maximum absorption in a desired range of about 0.3 or more and 2.0 or less.
750-360nm if the desired range is 750-1400nm
Is preferably 0.005 or more and less than 0.5, more preferably an antihalation layer having an optical density of 0.001 or more and less than 0.3. When the desired range is 750 nm or less, the halation is such that the maximum absorption in the desired range before image formation is 0.3 or more and 2.0 or less, and the optical density at 360-750 nm after image formation is 0.005 or more and less than 0.3. Preferably, it is a prevention layer. The method for lowering the optical density after image formation to the above range is not particularly limited. For example, as described in Belgian Patent No. 733,706, a method for lowering the density by heating by decoloring by heating, Japanese Patent Application Laid-Open No. 54-17833 discloses a method of reducing the density by decoloring by light irradiation.

When an antihalation dye is used in the present invention, such a dye has a desired absorption in a desired range, has a sufficiently low absorption in the visible region after treatment, and has a preferable absorbance spectrum shape of the back layer. Any compound may be used as long as is obtained. For example, the following are disclosed, but the present invention is not limited thereto.
As a single dye, JP-A-59-56458, JP-A-2-21
No. 6140, No. 7-13295, No. 7-11342, Compound described in U.S. Pat.No.5,380,635, JP-A-2-68539
No. 1, page 13, lower left column, line 1 to page 14, lower left column, line 9,
There are compounds described in the lower left column of page 14 to the lower right column of page 16 of JP-A-3-24539.
No. 39136, No. 53-132334, No. 56-501480, No. 57-16060, No. 57-68831, No. 57-10183
No. 5, JP-A-59-182436, JP-A-7-36145,
JP-A-7-199409, JP-B-48-33692, JP-A-50-16648
JP-B, JP-B-2-41734, U.S. Pat.No.4,088,497, JP-A-4,283,487, JP-A-4,548,896,
No. 5,187,049.

In the present invention, suitable binders for the back layer are transparent or translucent, generally colorless, and include natural polymers, synthetic resins, polymers and copolymers, and other film-forming media such as: gelatin, gum arabic, poly ( (Vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), 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 (e.g., poly (vinyl formal) and poly (vinyl formal))
(Vinyl butyral)), poly (ester) s, poly (urethanes), phenoxy resin, poly (vinylidene chloride), poly (vinylidene chloride)
(Epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, and poly (amides). The binder may be coated from water or an organic solvent or emulsion.

When the photothermographic material of the present invention is a one-sided light-sensitive material, a matting agent is added to the surface protective layer of the photosensitive emulsion layer and / or the back layer or the surface protective layer of the back layer to improve transportability. You may. The matting agent is generally fine particles of an organic or inorganic compound insoluble in water. Any matting agent can be used, for example, US Pat.
939,213, 2,701,245, 2,322,037
Nos. 3,262,782, 3,539,344, 3,767,448, etc.
1,260,772, 2,192,241, 3,257,20
Inorganic matting agents well-known in the art, such as inorganic matting agents described in the specifications such as JP-A-6, 3,370,951, 3,523,022, and 3,769,020, can be used. For example, specifically, examples of organic compounds that can be used as a matting agent include polymethyl acrylate, polymethyl methacrylate, polyacrylonitrile, and acrylonitrile-α- as examples of water-dispersible vinyl polymers.
Methylstyrene copolymer, polystyrene, styrene-divinylbenzene copolymer, polyvinyl acetate, polyethylene carbonate, polytetrafluoroethylene, etc., as examples of cellulose derivatives, methylcellulose,
Examples of starch derivatives such as cellulose acetate, cellulose acetate propionate, carboxy starch, carboxynitrophenyl starch, urea-formaldehyde-
Gelatin hardened with a known hardener such as a starch reactant and hardened gelatin obtained by coacervate hardening to form fine capsule hollow particles can be preferably used. Examples of the inorganic compound include silicon dioxide, titanium dioxide, magnesium dioxide, aluminum oxide, barium sulfate, calcium carbonate, silver chloride desensitized by a known method, silver bromide, glass, and diatomaceous earth. The above matting agents can be used by mixing different types of substances as necessary. The size and shape of the matting agent are not particularly limited, and those having an arbitrary particle size can be used. In the practice of the present invention, it is preferable to use one having a particle size of 0.1 μm to 30 μm. Further, the particle size distribution of the matting agent may be narrow or wide. On the other hand, since the matting agent greatly affects the haze of the photosensitive material and the surface gloss, the particle size,
It is preferable to make the shape and particle size distribution as required.

In the present invention, it is a preferred embodiment to add a matting agent to the backing layer. The matting degree of the backing layer is preferably a Beck smoothness of 1200 seconds or less and 10 seconds or more, more preferably 700 seconds or less and 50 seconds or more. It is. In the present invention, the matting agent is preferably contained in the layer functioning as the outermost surface layer or the outermost surface layer of the light-sensitive material, or a layer close to the outer surface, and is contained in a layer acting as a so-called protective layer. Is preferred. The matte degree of the emulsion surface protective layer may be any value as long as stardust failure does not occur, but the Beck smoothness is preferably from 500 seconds to 10,000 seconds, and particularly preferably from 500 seconds to 2,000 seconds. The photothermographic emulsion used in the present invention comprises one or more layers on a support. One layer must contain additional optional materials such as organic silver salts, silver halides, developers and binders, and toning agents, coating aids and other auxiliaries. The two-layer construction is that the first emulsion layer (usually the layer adjacent to the support) contains an organic silver salt and silver halide, and the second layer or both layers do not contain some other components. No. However, a two-layer construction comprising a single emulsion layer containing all components and a protective topcoat is also contemplated. The construction of the 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. You may go out. In the case of a multi-dye, multi-color photothermographic material, each emulsion layer is generally functionalized or non-functional between each emulsion layer (photosensitive layer) as described in U.S. Pat. No. 4,460,681. By using a functional barrier layer, they are kept distinct from each other.

Nos. 4,460,681 and U.S. Pat.
Backside resistance heating layer as shown in 4,374,921 specification
(Backside resistive heating layer) can also be used in a photosensitive heat development photographic image system. A hardener may be used for each layer such as the image forming layer (preferably the photosensitive layer), the protective layer and the back layer in the invention. Examples of hardeners include:
U.S. Pat.No. 4,281,060, polyisocyanates described in JP-A-6-208193 and the like, U.S. Pat.
Epoxy compounds described in 791,042 and the like, vinylsulfone 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, JP-A-62-170950, fluorinated polymer surfactants described in U.S. Pat. Fluorosurfactants described in U.S. Patent 3,885,96
No. 5, the polysiloxane surfactant described in the specification,
Examples thereof include polyalkylene oxides and anionic surfactants described in JP-A-6-301140.

The heat-developable photographic emulsion of the present invention can be generally 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,
Including paper, metal, etc. Flexible substrates, particularly coated with baryta and / or partially acetylated α-olefin polymers, especially polymers of C 2-10 α-olefins such as polyethylene, polypropylene, ethylene-butene copolymers A paper support is typically used. Such a support may be transparent or opaque, but is preferably transparent. Among them, biaxially stretched polyethylene terephthalate (PET) of about 75 to 200 μm is particularly preferred.

On the other hand, when a plastic film is passed through a heat developing machine at a temperature of 80 ° C. or more, the dimensions of the film generally expand and contract. If the processed material is used for printing plate making,
This expansion and contraction is a serious problem when performing precision multicolor printing.
Therefore, in the present invention, it is preferable to use a film having a small dimensional change, which is designed to reduce internal strain remaining in the film at the time of biaxial stretching and eliminate thermal shrinkage distortion generated during thermal development. For example, polyethylene terephthalate, which is heat-treated at 100 to 210 ° C. before coating the photographic emulsion for thermal development, is preferably used. Those having a high glass transition temperature are also preferable, and polyether ethyl ketone, polystyrene, polysulfone, polyethersulfone, polyarylate, polycarbonate and the like can be used. The photothermographic material according to the invention is, for antistatic purposes, for example, soluble salts (eg, chlorides, nitrates, etc.),
Evaporated metal layers, U.S. Pat.Nos. 2,861,056 and
No. 3,206,312 or ionic polymers as described in U.S. Pat.No. 3,428,451, insoluble inorganic salts as described in JP-A-60-252349 and JP-A-57-104931. It may have a layer containing tin fine particles and the like.

A method for obtaining a color image using the photothermographic material according to the present invention is described in Japanese Patent Application Laid-Open No.
There is a method described on page 43, left column, line 43 to page 11, left column, line 40. In addition, as a stabilizer for color dye images, UK Patent No.
No. 1,326,889, U.S. Pat.No. 3,432,300, No. 3,698,909, No. 3,574,627, No. 3,
No. 573,050, No. 3,764,337 and No. 4,
No. 042,394. The heat-developable photographic emulsion used in the present invention may be dip coating, air knife coating, flow coating, or U.S. Pat.
It can be coated by various coating operations, including extrusion coating using a hopper of the type described in US Pat. If desired, two or more layers can be coated simultaneously by the methods described in U.S. Pat. No. 2,761,791 and British Patent No. 837,095.

Additional layers in the photothermographic material of the present invention, such as a dye-receiving layer for receiving a moving dye image, an opaque layer if reflective printing is desired, a protective topcoat layer and photothermographic techniques It may include a known primer layer and the like. The photothermographic material of the present invention is preferably capable of forming an image with only one photosensitive material, and it is preferable that a functional layer required for image formation such as an image receiving layer does not become another photosensitive material. When the photothermographic material of the present invention is cut, any cutting method may be used. However, as a method of cutting into a roll shape, a so-called shear is used in which two upper and lower round blades are engaged and cut. A cutting method is used. An example of a specific cutting method using the shear cut method is described in Japanese Patent Application No. 10-219486. Examples of cutting are shown in FIGS. The cutting blade in the illustrated example is a thin blade in which both the upper blade 1 and the lower blade 2 have a certain blade angle, and the photothermographic material 3 is supplied in a direction perpendicular to the blade directions of the upper blade 1 and the lower blade 2. It has been. Therefore, the photothermographic material 3 is cut by the cutting edge, and the cut portion of the photothermographic material 3 forms an edge portion of the photothermographic material 3 after cutting. The cutting blade may be of any material and shape, but the cutting edge angle (angles a and b in the example of FIG. 2) of the cutting blade is preferably 60 degrees or more and 90 degrees or less, and 70 degrees or more and 90 degrees or less. Is particularly preferred. If the photothermographic material cut using the cutting blade having such a cutting edge angle is wrapped according to the present invention, the effect of the present invention can be further enhanced.

The shape of the photothermographic material of the present invention after cutting may be a sheet or a roll. In a roll form, the core can secure light-shielding properties as a whole,
The roll-form photothermographic material is not particularly limited as long as it does not adversely affect the photothermographic material. The roll-type photothermographic material may have one layer or two or more layers, and may be formed of paper or plastic. In the present invention, the water content of the core is preferably 4 wt% or more and 7 wt% or less, and more preferably 4 wt% or more and 6 wt%.
The following are particularly preferred. The moisture content in this case is the value after packaging, and specifically, is the rate of change in weight when dried at 30 ° C. for 1 day under a vacuum of 1 Torr or less. The winding core is cylindrical, but may be a hollow body. When the hollow body is used, the thickness of the material depends on the material, but is about 3 mm.

The temperature of the photothermographic material of the present invention immediately before thermal development is preferably adjusted to 20 to 40 ° C. (for example, 30 ° C.). By adjusting the temperature immediately before the heat development to 20 to 40 ° C., the sensitivity fluctuation can be reduced.

In the present invention, the exposure apparatus used for imagewise exposure may be any apparatus capable of performing exposure with an exposure time of less than 10 ^-7 seconds.
D), an exposure apparatus using a Light Emitting Diode (LED) as a light source is preferably used. In particular, LD is more preferable in terms of high output and high resolution. Any of these light sources may be used as long as it can generate light of an electromagnetic wave spectrum in a target wavelength range. For example, for LD,
Dye lasers, gas lasers, solid-state lasers, semiconductor lasers, and the like can be used. The term “exposure” as used in the present invention means that the exposure is performed by overlapping the light beams of the light source, and the term “overlap” means that the sub-scanning pitch width is smaller than the beam diameter. For example, overlap
FWHM / sub-scanning pitch width (overlap coefficient) when the beam diameter is represented by the half width of beam intensity (FWHM)
Can be quantitatively expressed by In the present invention, the overlap coefficient is preferably 0.2 or more.

The scanning method of the light source of the exposure apparatus used in the present invention is not particularly limited, and a cylinder outer surface scanning method, a cylinder inner surface scanning method, a plane scanning method, or the like can be used. Also,
The channel of the light source may be a single channel or a multi-channel, but in the case of a cylindrical outer surface type, a multi-channel is preferably used. The photothermographic material of the present invention has a low haze at the time of exposure and tends to cause interference fringes.
Examples of this interference fringe prevention technology include a technology for obliquely entering a laser beam into a photosensitive material as disclosed in Japanese Patent Application Laid-Open No. 5-113548, and a technology disclosed in International Publication WO95 / 31754. There are known methods using a multimode laser, and it is preferable to use these techniques.

In the heat development step of the image forming method of the present invention, any developing method may be used. Usually, the photosensitive material exposed imagewise is heated to develop. As a preferred embodiment of the thermal developing machine to be used, a type in which the photothermographic material is brought into contact with a heat source such as a heat roller or a heat drum is disclosed in Japanese Patent Publication No. 5-56499 and Japanese Patent No. 684453.
JP, 9-292695, JP-A-9-297385 and WO95 / 30934, a thermal developing machine described in JP-A-7-13294 as a non-contact type, and WO 97/28489, JP 97/28488 and
There is a heat developing machine described in JP-A-97 / 28487. A particularly preferred embodiment is a non-contact type thermal developing machine. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 250 ° C.
140 ° C. The development time is preferably from 1 to 180 seconds,
0-90 seconds is more preferred. As a method of preventing processing unevenness due to a dimensional change during thermal development of the photothermographic material of the present invention, heating is carried out at a temperature of 80 ° C. or more and less than 115 ° C. (preferably 113 ° C. or less) for 5 seconds or more so that an image does not appear. After that, a method of performing heat development at 110 ° C. or more and 140 ° C. or less to form an image (a so-called multi-stage heating method) is effective.

FIG. 3 shows an example of the configuration of a heat developing machine used for the heat developing process of the photothermographic material of the present invention. FIG. 3 is a side view of the heat developing machine. The heat developing machine in FIG. 3 flattens the photothermographic material 10 into a heating section while correcting and preheating the photothermographic material 10 into a planar shape (the lower roller is a heat roller) and the photothermographic material 10 after thermal development. It has an unloading roller pair 12 that unloads it from the heating unit while correcting the shape. The photothermographic material 10 is thermally developed while being transported from the carry-in roller pair 11 to the carry-out roller pair 12. In the conveying means for conveying the photothermographic material 10 during the heat development, a plurality of rollers 13 are provided on the side where the surface having the image forming layer contacts, and the non-woven fabric (for example, A smooth surface 14 on which aromatic polyamide or Teflon) is attached is provided. The back surface of the photothermographic material 10 is conveyed by sliding on the smooth surface 14 by driving a plurality of rollers 13 that come into contact with the surface having the image forming layer. Heating means roller 1
3 and the photothermographic material 10
The heater 15 is installed so as to be heated from both sides. As a heating means in this case, a plate heater or the like can be used. Although the clearance between the roller 13 and the smooth surface 14 varies depending on the member of the smooth surface, it is appropriately adjusted to a clearance that can transport the photothermographic material 10. Preferably it is 0 to 1 mm.

Material of Roller 13 Surface and Smooth Surface 1
The member of No. 4 is durable at high temperature and may be anything as long as it does not hinder the conveyance of the photothermographic material 10, but the material of the roller surface is made of silicone rubber, and the member of the smooth surface is made of aromatic polyamide or Teflon (PTFE). Non-woven fabrics are preferred. It is preferable to use a plurality of heaters as the heating means and to set the heating temperature freely. The heating unit is
The pre-heating unit A includes the pre-heating unit A having the carry-in roller pair 11 and the heat development processing unit B including the heating heater 15. The pre-heating unit A upstream of the heat development processing unit is lower than the heat development temperature (for example, 10 to 50 ° C.), photothermographic material 1
It is desirable to set the temperature and the time sufficient to evaporate the amount of water in 0. At a temperature higher than the glass transition temperature (Tg) of the support of the photothermographic material 10, development unevenness does not occur. It is preferable to set.

Further, a guide plate 16 is provided downstream of the thermal development processing section B, and a slow cooling section C having the carry-out roller pair 12 and the guide plate 16 is provided. The guide plate 16 is preferably made of a material having low thermal conductivity, and is preferably cooled gradually. As described above, the description has been given according to the illustrated example.
For example, the thermal developing machine used in the present invention, such as that described in JP-A-7-13294, may have various structures. In the case of the multi-stage heating method preferably used in the present invention, in the above-described apparatus, two or more heat sources having different heating temperatures may be provided, and heating may be performed continuously at different temperatures.

The photothermographic material of the present invention may be passed through a temperature control device for keeping the temperature of the photothermographic material constant before the heat development in order to reduce the sensitivity fluctuation during the heat development. It is preferable that the temperature adjusting device is placed between the exposing machine and the heat developing machine, and passes through the photosensitive material immediately before inserting it into the heat developing machine. The temperature of the photosensitive material after the temperature adjustment is 20 to 40.
C is preferable, and 25 to 35 C is more preferable. FIG. 4 shows an example of the configuration of the temperature adjusting device. FIG. 4 shows a side view of each of the exposing device 20, the temperature adjusting device 21, and the heat developing device 22. The temperature adjusting device 21 includes the carry-in roller pair 2
3 and 24 and a pair of discharge rollers 24 and 25. The temperature may be adjusted by any method, and the roller pair may be maintained at a constant temperature as a heat roller, or may be a mechanism having a heater and a cooler inside the apparatus and keeping the inside of the apparatus at a uniform temperature. . The photosensitive material 10 exposed by the exposing machine 20 is inserted into a temperature adjusting device 21, the temperature of which is adjusted while passing through a pair of rollers 23, 24 and 25, 26, and carried out to a heat developing machine 22. The material of the roller surface is not particularly limited as long as the transport of the photosensitive material 10 is not hindered.

When the photothermographic material of the present invention is subjected to thermal development processing, it is exposed to a high temperature of 110 ° C. or higher, so that some of the components contained in the material or some of the components decomposed by thermal development are exposed. Volatilizes. These volatile components may cause uneven development, corrode the components of the heat developing machine, precipitate at low temperatures, cause deformation of the screen as foreign matter, and adhere to the screen and become dirty. Is known to have a bad effect. In order to eliminate these effects, it is known to install a filter in the heat developing machine and optimally adjust the flow of air in the heat developing machine. These can be effectively used in combination. International Patent Publication Nos. WO95 / 30933, 97/21150, and JP-T-10-500496 disclose a first opening for binding and absorbing particles and a second opening for discharging volatile components. It is described that a filter cartridge having the following is used for a heating device that heats the film in contact with a film. International Patent Publication No. WO 96/12213 and Japanese Patent Publication No. 10-507403 describe a filter in which a heat-conductive condensation collector and a gas-absorbing fine particle filter are combined. No. 4,518,84.
No. 5, JP-B 3-54331 describes a configuration having a device for removing vapor from a film, a pressurizing device for pressing the film against a heat transfer member, and a device for heating the heat transfer member. ing. International Publication WO 98/27458 describes removing a component that increases fogging that evaporates from a film from the film surface.
The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto.

[0122]

[Example] <Example 1> 1. Preparation of silver halide emulsion (Emulsion A) 11 g of alkali-treated gelatin (2700 ppm or less in terms of calcium content) and potassium bromide 30 in 700 ml of water
and 10 mg of sodium benzenethiosulfonate were dissolved and the pH was adjusted to 5.0 at a temperature of 40 ° C., and 159 ml of an aqueous solution containing 18.6 g of silver nitrate and 1 mol / l of potassium bromide, (N
An aqueous solution containing 5 × 10 ⁻⁶ mol / L of H ₄ ) ₂ RhCl ₅ (H ₂ O) and 2 × 10 ⁻⁵ mol / L of K ₃ IrCl ₆ was maintained at a pAg of 7.7 by a control double jet method. Minutes over 30 seconds. Then, while maintaining 476 ml of an aqueous solution containing 55.5 g of silver nitrate and an aqueous solution of a halogen salt containing 1 mol / l of potassium bromide and 2 × 10 ^-5 mol / l of K ₃ IrCl ₆ at a pAg of 7.7, a control double jet method was used. Minutes over 30 seconds. Thereafter, the pH was lowered to perform coagulation sedimentation and desalting treatment, and 0.17 g of compound A and 51.1 g of low-molecular-weight gelatin having an average molecular weight of 15,000 (calcium content of 20 ppm or less) were added, pH 5.9, pAg 8.0 Was adjusted. The obtained particles were cubic particles having an average particle size of 0.08 μm, a projected area variation coefficient of 9%, and a (100) plane ratio of 90%.

The silver halide grains thus obtained were heated to 60 ° C., and 76 μmol of sodium benzenethiosulfonate was added per 1 mol of silver, and after 3 minutes, 71 μm of triethylthiourea was added.
Mol, and the mixture was aged for 100 minutes.
Methyl-1,3,3a, 7-tetrazaindene is 5 × 10
After adding ^-4 mol, the temperature was lowered to 40 ° C. Thereafter, the temperature was maintained at 40 ° C., and 12.8 × 10 ⁻⁴ mol of sensitizing dye A and 6.4 × 10 ⁻³ mol of compound B were added to 1 mol of silver halide with stirring, and after 20 minutes, 30 ° C. Silver halide emulsion A
Was completed.

[0124]

Embedded image

[0125] 2. Preparation of Organic Acid Silver Dispersion <Organic Acid Silver A> Behenic acid manufactured by Henkel (product name Eden)
or C22-85R) 87.6 g, distilled water 423 ml, 5N-NaOH aqueous solution 49.
2 ml, tert-butyl alcohol 120 ml mixed, at 75 ℃
The mixture was stirred and reacted for 1 hour to obtain a sodium behenate solution. Separately, prepare 206.2 ml of an aqueous solution of 40.4 g of silver nitrate,
Was kept warm. A reaction vessel containing 635 ml of distilled water and 30 ml of tert-butyl alcohol was kept at 30 ° C., and while stirring, the entire amount of the sodium behenate solution and the entire amount of the silver nitrate aqueous solution were kept at a constant flow rate for 62 minutes 10 seconds and 60 minutes, respectively. Added over minutes. At this time, only the aqueous solution of silver nitrate was added for 7 minutes and 20 seconds after the start of the aqueous solution of silver nitrate, and then the addition of the sodium behenate solution was started.
For 9 minutes and 30 seconds, only the sodium behenate solution was added. At this time, the temperature in the reaction vessel was 30 ° C,
The liquid temperature was controlled so as not to rise. In addition, the piping of the addition system for the sodium behenate solution was kept warm by steam tracing, and the liquid temperature at the outlet of the addition nozzle tip was 75%.
The steam amount was controlled so as to reach ℃. Also,
The piping of the silver nitrate aqueous solution addition system was kept warm by circulating cold water outside the double tube. The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution. After the completion of the addition of the sodium behenate solution, the mixture was allowed to stir at the same temperature for 20 minutes, and then cooled to 25 ° C. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm. The solid thus obtained was stored as a wet cake without drying. When the morphology of the obtained silver behenate grains was evaluated by electron micrographing, the average projected area diameter was 0.52 μm,
It was a flaky crystal having an average particle thickness of 0.14 μm and a coefficient of variation of the average equivalent sphere diameter of 15%.

Next, a dispersion of silver behenate was prepared by the following method. To a wet cake having a dry solid content of 100 g, 7.4 g of polyvinyl alcohol (trade name: PVA-217, average degree of polymerization: about 1700) and water are added, and the total amount is 385 g.
And then predispersed with a homomixer. Next, the pressure of the predispersed undiluted solution was adjusted to 1750 kg / cm ² with a dispersing machine (trade name: Microfluidizer M-110S-EH, manufactured by Microfluidics International Corporation, using a G10Z interaction chamber), and This was repeated to obtain a silver behenate dispersion. In the cooling operation, a coiled heat exchanger was mounted before and after the interaction chamber, and the temperature of the refrigerant was adjusted to a desired dispersion temperature. The silver behenate particles contained in the silver behenate dispersion thus obtained have a volume-weighted average diameter of 0.52 μm,
The particles had a coefficient of variation of 15%. Particle size measurement is Mal
Vern Instruments Ltd. made MasterSizerX. When evaluated by electron microscopy, the ratio of the long side to the short side is
The average aspect ratio (the ratio of the circle equivalent diameter of the projected area of the particle to the particle thickness) was 1.5, the particle thickness was 0.14 μm, and the average aspect ratio was 5.1.

[0127] 3. 1,1-bis (2-hydroxy-3,5-dimethyl
Ruphenyl) -3,5,5-trimethylhexane: reducing agent solid fine
Preparation of particle dispersion 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-
25 g of a 20 wt% aqueous solution of MP-203 manufactured by Kuraray Co., Ltd. to 25 g of trimethylhexane, 0.1 g of Safinol 104E manufactured by Nissin Chemical Co., Ltd., 2 g of methanol and 48 ml of water were added and stirred well. The slurry was left for 3 hours. Thereafter, 360 g of 1 mm zirconia beads were prepared, put into a vessel together with the slurry, and dispersed with a dispersing machine (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) for 3 hours to prepare a solid fine particle dispersion of a reducing agent. . As for the particle diameter, 80% by weight of the particles were 0.3 μm or more and 1.0 μm or less.

[0128] 4. Solid fine particles of polyhalogen compounds
Preparation of powder 4 g of MP-203 of MP polymer manufactured by Kuraray Co., Ltd., 0.25 g of compound C and 66 g of water were added to 30 g of the polyhalogen compound-A and stirred well, and then 0.5 mm zirconia silicate beads were added. Was prepared in a vessel together with the slurry, and dispersed for 5 hours with a dispersing machine (1 / 16G sand grinder mill: manufactured by Imex Co., Ltd.) to prepare a solid fine particle dispersion. Particle size, 80% by weight of the particles is 0.3 μm or more 1.0
μm or less. For polyhalogen compound-B, a solid fine particle dispersion was prepared in the same manner as for polyhalogen compound-A, and had the same particle diameter.

[0129] 5. Preparation of solid fine particle dispersion of nucleating agent To 10 g of nucleating agent described in Table 1, 2.5 g of polyvinyl alcohol (PVA-217 manufactured by Kuraray) and 87.5 g of water were added, and the mixture was stirred well and left as a slurry for 3 hours. did. Thereafter, 240 g of 0.5 mm zirconia beads were prepared, put into a vessel together with the slurry, and dispersed for 10 hours with a dispersing machine (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) to prepare a solid fine particle dispersion. . Particle size, 80% by weight of particles is 0.1 μm or more
It was 1.0 μm or less and the average particle size was 0.5 μm.

[0130] 6. Preparation of Solid Fine Particle Dispersion of Compound Z To 30 g of Compound Z, 3 g of MP-203 (manufactured by Kuraray Co., Ltd.) and 87 ml of water were added, stirred well, and left as a slurry for 3 hours. Thereafter, a solid fine particle dispersion of the compound Z was prepared in the same manner as in the preparation of the reducing agent solid fine particle dispersion. Particle size: 80% by weight of particles is 0.3μm or more
It was 1.0 μm or less.

[0131] 7. Preparation of Emulsion Layer Coating Solution The following binder, material, and silver halide emulsion A were added to 1 mol of silver of the organic acid silver microcrystal dispersion prepared above, and water was added. Liquid. Binder; Luckstar 3307B 397 g as solid content (manufactured by Dainippon Ink and Chemicals, Inc .; glass transition temperature of 17 ° C. with SBR latex) 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5 , 5,5-Trimethylhexane 149g as solid content Polyhalogen compound-A 34.8g as solid content Polyhalogen compound-B 9.0g as solid content Sodium ethylthiosulfonate 0.30g Benzotriazole 0.5g Compound-G 2.1g Polyvinyl alcohol (Kuraray ( 10.8 g 6-iso-propylphthalazine 15.0 g Sodium dihydrogen orthophosphate dihydrate 0.37 g Compound Z 9.7 g as solid nucleating agent Kind shown in Table 1 0.03 mol Dye A Amount of coating at which the optical density at 783 nm becomes 0.3 (0.37 g as a guide) Silver halide emulsion A 0.06 mol as Ag amount

[0132]

Embedded image

[0133] 8. Preparation of Coating Solution for Lower Emulsion Surface Protective Layer Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 58.9 / 8.6 / 25.4 / 5.1 / 2 (wt%) polymer latex solution (copolymer H ₂ O was added to 956 g of a glass transition temperature of 57 ° C., a solid content concentration of 21.5 wt%, and a compound D as a film-forming auxiliary (containing 15 wt% based on the solid content of the latex),
Compound E 1.62 g, matting agent (polystyrene particles, average particle size 7 μm) 1.98 g and polyvinyl alcohol (Kuraray
Ltd., added PVA-235) 23.6 g, further adding H ₂ O,
A coating solution was prepared.

9. Preparation of Coating Solution for Emulsion Upper Protective Layer Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 58.9 / 8.6 / 25.4 / 5.1 / 2 (wt%) polymer latex solution (copolymer H ₂ O was added to 630 g of a glass transition temperature of 54 ° C., a solid concentration of 21.5 wt%, and a compound D as a film-forming aid (containing 15 wt% based on the solid content of the latex).
Carnava wax (Chukyo Yushi Co., Ltd., Cellosol 52
4) 30 wt% solution 6.30 g, Compound E 0.72 g, Compound F 7.95
g, matting agent (polystyrene particles, average particle size 7 μm) 1.18
g and polyvinyl alcohol (Kuraray Co., Ltd., PVA-23
5) 8.30 g was added, and further H ₂ O was added to prepare a coating solution.

[0135]

Embedded image

[0136] 10. PET support with back / undercoat layer
Preparation of body (1) Support PET of IV (intrinsic viscosity) = 0.66 (measured at 25 ° C. in phenol / tetrachloroethane = 6/4 (weight ratio)) using terephthalic acid and ethylene glycol according to a conventional method. Obtained. After pelletizing this, it was dried at 130 ° C for 4 hours,
After being melted at 00 ° C., the film was extruded from a T-die and rapidly cooled to prepare an unstretched film having a thickness of 120 μm after heat setting. This was longitudinally stretched 3.3 times using rolls having different peripheral speeds, and then horizontally stretched 4.5 times using a tenter.
The temperatures at this time were 110 ° C. and 130 ° C., respectively. After that, it was heat-set at 240 ° C. for 20 seconds and relaxed 4% in the lateral direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling was performed on both ends, and the film was wound at 4.8 kg / cm ² . Thus, width 2.4m, length 3500m, thickness 120
A μm roll was obtained.

(2) Undercoat layer (a) Polymer latex- (1) (a core-shell type latex having a core of 90% by weight and a shell of 10% by weight, core: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / Acrylic acid = 93/3/3 / 0.9 / 0.1 (% by weight), shell part: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 88/3/3/3/3 (% by weight) Polymer latex having a weight average molecular weight of 38000) As solid content 3.0 g / m ² 2,4-dichloro-6-hydroxy-s-triazine 23 mg / m ² Matting agent (polystyrene, average particle size 2.4 μm) 1.5 mg / m ²

(3) Undercoat layer (b) Deionized gelatin (Ca ²⁺ content 0.6 ppm, jelly strength 230 g) 50 mg / m ² (4) Conductive layer Julimer ET-410 (manufactured by Nippon Pure Chemical Co., Ltd.) 96 mg / m ² alkali-treated gelatin (molecular weight about 10,000, Ca ²⁺ content 30 ppm) 42 mg / m ² deionized gelatin (Ca ²⁺ content 0.6 ppm) 8 mg / m ² Compound A 0.2 mg / m ² polyoxyethylene phenyl ether 10 mg / m ² Sumitex Resin M-3 (Water-soluble melamine compound, manufactured by Sumitomo Chemical Co., Ltd.) 18 mg / m ² Dye A Amount of coating at which the optical density of 783 nm becomes 1.2 SnO ₂ / Sb (9/1 weight ratio, Needle-shaped fine particles, major axis / minor axis = 20-30, manufactured by Ishihara Sangyo Co., Ltd.) 160 mg / m ² matting agent (polymethyl methacrylate, average particle diameter 5 μm) 7 mg / m ²

(5) Protective Layer Polymer Latex- (2) (Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 59/9/26/5/1 (weight% copolymer) )) 1000mg / m ² polystyrenesulfonate solid basis (molecular weight 1000~5000) 2.6mg / m ² Cellosol 524 (Chukyo Yushi (Co.)) 25mg / m ² Sumitex resin M-3 (water-soluble melamine compound, Sumitomo sequentially applying the undercoat layer (a) and undercoat layer (b) on both sides of the chemical Co., Ltd.) 218 mg / m ² (6) back / subbing layers marked with PET support prepared support (base), Each was dried at 180 ° C. for 4 minutes. Then, the undercoat layer (a) and the undercoat layer (b) were applied, and a conductive layer and a protective layer were sequentially applied to one surface on one side.
After drying for minutes, a PET support with a back / subbing layer was prepared. The dry thickness of the undercoat layer (a) was 2.0 μm.

(7) Heat treatment for transport (7-1) Heat treatment The PET with the back / undercoat layer produced as described above
Place the support in a heat treatment zone with a total length of 200 m set at 160 ° C,
It was transported at a tension of 3 kg / cm ² and a transport speed of 20 m / min. (7-2) Post heat treatment Following the heat treatment, post heat treatment was performed by passing through a zone at 40 ° C for 15 seconds, and winding was performed. The winding tension at this time is 10
kg / cm ² .

[0141]

Embedded image

[0142] 11. Preparation of a photothermographic material The above-mentioned undercoat layer (a) and the undercoat layer on the side of the PET support coated with the undercoat layer (b) were coated with the emulsion layer coating solution described above in an amount of 1.7 g of silver.
/ m ² . Further, the coating solution for the lower protective layer on the emulsion surface was simultaneously coated with the emulsion coating solution so that the coating amount of the solid content of the polymer latex was 1.31 g / m ² . Thereafter, the coating solution for the upper protective layer on the emulsion surface was applied thereon so that the applied amount of the solid content of the polymer latex was 3.02 g / m ² , thereby producing a photothermographic material (sample). The film surface pH of the obtained photothermographic material on the image forming layer side is 4.
9.Beck smoothness is 660 seconds, and the pH of the opposite surface is 5.
9. Beck smoothness was 560 seconds.

12. Cutting of photothermographic material Using a stainless disk-shaped cutting blade having a blade angle (edge angle) at the edge portion as shown in Table 1, the photothermographic material is 61 cm wide and 59 m long. Cutting was performed. The sample to be cut was conveyed at a speed of 100 m / min, and the disk-shaped cutting blade was rotated so that the center was fixed and the outer periphery had a speed of 120 m / min (see FIGS. 1 and 2).

13. Packaging of the Photothermographic Material The photothermographic material cut above was wound around a cylindrical paper core having a thickness of 3 mm, a diameter of 76 mm and a width of 61 cm to prepare a roll-form photothermographic material. Further, both sides of the roll are shielded from light by a black polystyrene plate having a thickness of 3 mm.
A black polyethylene film of μm was wound around the circuit three times without gaps.

[0145] 14. Humidity control of photothermographic material The photothermographic material prepared above was allowed to stand at 25 ° C under different relative humidity environments for one day so that the relative humidity inside the package as shown in Table 1 was finally obtained. Conditioned. The water content of the core is also shown.

[0146] 15. Evaluation of photographic performance (exposure processing) The obtained photothermographic material was subjected to a beam diameter (FWHM of 1/2 of beam intensity) of 12.56 μm and a laser output of 50 m.
W, using a single-channel cylindrical inner surface laser exposure device equipped with a semiconductor laser with an output wavelength of 783 nm, adjust the exposure time by changing the number of rotations of the mirror, adjust the exposure amount by changing the output value, 2 Exposure was performed in × 10 ⁻⁸ seconds. The overlap coefficient at this time was set to 0.449. (Heat development treatment) The exposed heat-developable photosensitive material was heated using a heat development machine shown in FIG. 3 and the roller surface material of the heat development treatment section was made of silicone rubber, and the smooth surface was made of Teflon nonwoven fabric.
A heat development process was performed at 100100 ° C. for 5 seconds and a heat development processing unit at 120 ° C. for 20 seconds. The temperature accuracy in the width direction was ± 1 ° C.

(Evaluation of Photographic Characteristics 1) The obtained images were evaluated using a Macbeth TD904 densitometer (visible density). The measurement results were evaluated by Dmin and sensitivity (evaluated by the relative value of the reciprocal of the ratio of the exposure amount giving a density 1.5 higher than Dmin, and
Was set to 100), Dmax, and γ (contrast). γ is represented by the slope of a straight line connecting the points of density 0.2 and 2.5, excluding the Dmin part, with the logarithm of the exposure amount as the horizontal axis. (Evaluation of photographic properties 2) Store the package as it is at 40 ° C (outside temperature) for 14 days, and perform the above-mentioned exposure and thermal development processing on the central part (30 m from the outer peripheral part) after storage, and change the Dmin and the sensitivity fluctuation range. Was evaluated.

(Edge fog) The image was stored in the same manner as in the evaluation of photographic characteristics 2, and the degree of fog at the edge (a portion within a range of 3 mm from the cut portion) was visually evaluated. "5" is the best and "1" is the worst. “3” is a practically usable level, although slightly deteriorated. Table 1 shows the results of the above evaluation for each photothermographic material.
Shown in

[0149]

[Table 1]

In the case of the photothermographic material of the present invention, Dm
It can be seen that good performance with low in (fog), high sensitivity, high Dmax, little fog increase during storage, and small sensitivity fluctuation. Further, it can be seen that the use of the compounds of formulas (1) to (3) as the nucleating agent is superior to the formyl hydrazine-based compound in terms of fog and sensitivity fluctuation during storage. From the above, the effect of the present invention is clear.

<Example 2> Samples 4, 9, and 13 of Example 1
Was subjected to the same exposure processing and heat development processing as in Example 1 under conditions of different temperature environments as shown in Table 2,
Further, the temperature of the sample was adjusted by the temperature adjusting device shown in FIG. 4 immediately before the heat development, and the photographic characteristics 1 were evaluated. The results are shown in Table 2.

[0152]

[Table 2] Ambient temperature Experiment No. immediately before thermal development . Sample No. (° C.) Sample temperature (° C.) Sensitivity Remarks 1 415 15 97 Present invention 2 430 30 104 Present invention 3 415 30 102 Present invention 4 430 30 103 Present invention 5 915 15 15 98 Present invention 6 930 30 105 The present invention 9 9 15 30 103 The present invention 8 9 30 30 105 The present invention 9 13 15 15 96 The present invention 10 13 30 30 101 The present invention 11 13 15 30 99 The present invention 12 13 30 30 100 The present invention

Table 2 shows that the sensitivity was small when the sample was kept at 30 ° C. by adjusting the temperature immediately before thermal development.

<Example 3> The roll-form photothermographic material of Example 1 was packed with a packaging material having a laminated structure containing an aluminum foil. The laminated structure of the packaging material is 70 μm polyethylene, 7 μm aluminum foil, and 40 μm polyethylene from the inside. The relative humidity inside such a package is measured in Example 1.
When the same evaluation was performed as in Example 1,
The same results as in Example 1 were obtained.

[0155]

According to the present invention, it has become possible to provide an excellent package of a photothermographic material excellent in small fog, excellent in high contrast, and little in fog increase and sensitivity fluctuation upon storage.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of cutting a photothermographic material according to the present invention.

FIG. 2 is a sectional view showing an example of cutting the photothermographic material of the present invention.

FIG. 3 is a side view showing a configuration example of a heat developing machine used for a heat development process of the photothermographic material of the present invention.

FIG. 4 shows an example of a configuration of a temperature adjusting device installed before a thermal developing machine.

[Explanation of symbols]

 Reference Signs List 1 upper blade 2 lower blade 3,10 photothermographic material 11 carry-in roller pair 12 carry-out roller pair 13 roller 14 smooth surface 15 heating heater 16 guide plate A preheating section B heat development processing section C slow cooling section a, b DESCRIPTION OF SYMBOLS 20 Exposure machine 21 Temperature control device 22 Heat developing machine 23,24 Carry-in roller pair 25,26 Carry-out roller pair

Claims (7)

[Claims] 1. A package of a photothermographic material obtained by packaging a photothermographic material having a non-photosensitive silver salt, a photosensitive silver halide, a nucleating agent and a binder on a support with a packaging material, A package of a photothermographic material, wherein the relative humidity in the package is 10% or more and 50% or less. 2. The method according to claim 1, wherein the photothermographic material is 4% by weight or more.
The package of the photothermographic material according to claim 1, wherein the package is formed in a roll shape by being wound around a cylindrical core having a moisture content of not more than weight%. 3. The nucleating agent is a substituted alkene derivative represented by the following formula (1), a substituted isoxazole derivative represented by the following formula (2), and an acetal compound represented by the following formula (3): The package of the photothermographic material according to claim 1, which is at least one compound selected from the group consisting of: Embedded image [In the formula (1), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent, and Z represents an electron-withdrawing group or a silyl group. In the formula (1), R ¹ and Z, R ² and R
³ , R ¹ and R ² , and R ³ and Z may be bonded to each other to form a cyclic structure. In the formula (2), R
⁴ represents a substituent. In the formula (3), X and Y each independently represent a hydrogen atom or a substituent;
Each independently represents an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic oxy group, a heterocyclic thio group or a heterocyclic amino group. In the formula (3), X and Y, and A and B may be bonded to each other to form a cyclic structure. ] 4. A latex of a polymer having a glass transition temperature of −30 ° C. to 40 ° C. as 50% by weight or more of the binder of the image forming layer containing the photosensitive silver halide. A package of the photothermographic material according to any one of the above. 5. The photothermographic material according to claim 5, wherein the edge angle is 60.
The package of the photothermographic material according to any one of claims 1 to 4, wherein the package is cut with a cutting blade of not less than 90 degrees and not more than 90 degrees. 6. The packaging material has a thickness of 1 μm or more and 50 μm or more.
The metal foil contains the following metal foil.
A package of the photothermographic material according to any one of the above. 7. A heat-developable image forming method for taking out the photothermographic material contained in the package according to claim 1 and exposing the photothermographic material to heat development. A method for forming a heat-developable image, wherein the temperature of the photothermographic material before development is adjusted to a range of 20 ° C. or more and 40 ° C. or less.