JP2001264924A - High-speed heat developable photosensitive material and image forming method for them same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-speed heat developable photosensitive material having small dependency of the lime width of letters on light exposure and capable of giving good image quality in high-speed heat development. SOLUTION: In the high-speed heat developable photosensitive material with an image forming layer containing a non-photosensitive silver salt, photosensitive silver halide, a nucleus forming agent and a binder on at least one face of the base, the image forming layer contains solid fine particles of one or more water-insoluble organic compounds and the average particle diameter of the solid fine particles of each of the water-insoluble organic compounds is <0.05 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed photothermographic material, and more particularly to a high-speed photothermographic material for scanners and imagesetters suitable for photoengraving. Line width (actual sensitivity)
And an image forming method having a small dependence on the exposure amount.

[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 of forming an image by thermal development is described in, for example, US Pat. Nos. 3,152,904 and 3,45.
7,075, and D.C. Crosta Bohr (Klos
terboer) "Heat treated silver system (T
hermally Processed SilverSystems) A "(Imaging Processes and Materials (Imaging
Processes and Materials) Neblette 8th edition, J.M. Sturge, V.S. Walworth,
A. Edited by Shepp, Chapter 9, page 279,
1989). 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,
When heated to a high temperature (for example, 80 ° C. or higher) after exposure,
Silver is produced through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and a reducing agent. 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. Further, although the photothermographic materials have been known, most of them are toluene,
The photosensitive layer is formed by applying a coating solution using an organic solvent such as methyl ethyl ketone (MEK) or methanol as a solvent. Using an organic solvent as a solvent,
This is disadvantageous not only in the adverse effect on the human body in the manufacturing process but also in the cost due to the 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 an aqueous solvent which does not have such a concern has been considered. For example, JP-A-49-52626 and JP-A-53-116144 disclose examples using gelatin as a binder. JP-A-50-151138 discloses an example in which polyvinyl alcohol is used as a binder. Further, Japanese Patent Application Laid-Open No. 60-61747 discloses 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. When such a binder is used, a photosensitive layer can be formed using a coating solution of a water solvent, and the merits in terms of environment and cost are great.

In order to obtain high-contrast photographic characteristics, European Patent Publication EP-76
JP-A-2,196, JP-A-9-90550 and the like disclose that a photosensitive silver halide grain contains a group VII or VIII group metal ion or metal complex ion or a hydrazine derivative in a photothermographic material. It has been disclosed.

Although various improvements have been made to photothermographic materials in view of the environment, cost and photographic characteristics, there is still room for improvement in the speed of heat development. In general, when a photoengraving film is used in the newspaper field or the like, it is desired to process the film quickly because productivity is pursued. However, the photothermographic material has a problem that the character line width (practical sensitivity) has a large dependence on the exposure amount as compared with the conventional chemically processed film, and thus the line speed cannot be increased to perform the thermal development quickly. . For this reason, it has been desired to provide a photothermographic material for high-speed thermal development, which has a small and stable dependence on the exposure amount of the character line width and is optimal for photolithography.

[0007]

SUMMARY OF THE INVENTION Accordingly, a first object of the present invention is to provide a small image line with a small dependence on the exposure amount and to provide good image quality when high-speed thermal development processing is performed. It is an object of the present invention to provide a high-speed photothermographic material which can be used, particularly for photolithography, especially for a scanner and an image setter. A second object of the present invention is to provide a method for forming an image on a photothermographic material having a small dependence of the character line width on the exposure amount at a high speed.

[0008]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, a photothermographic material in which the particle diameter of solid fine particles of a water-insoluble organic compound contained during image formation is controlled. It has been found that the intended purpose can be achieved by thermally developing the compound at a high line speed within a certain range, thereby providing the present invention. That is, the present invention relates to a high-speed photothermographic material having an image-forming layer comprising at least one surface on a support, comprising a non-photosensitive silver salt, a photosensitive silver halide, a nucleating agent and a binder. The layer contains at least one solid fine particle of a water-insoluble organic compound, and provides a high-speed photothermographic material in which the average particle diameter of the solid fine particles of each water-insoluble organic compound is less than 0.05 μm. At least one of the solid fine particles contained in the high-speed photothermographic material of the present invention is preferably made into fine particles by media dispersion using beads having an average particle diameter of 300 μm or less. The number average grain size of the photosensitive silver halide is from 0.01 μm to 0.1 μm.
It is preferably 08 μm. Further, the present invention provides a method for producing a high-speed photothermographic material according to the present invention, in which the line speed is 140 to 700 c.
There is also provided an image forming method characterized by performing heat development at m / min. In this specification, “to” indicates a range that includes numerical values described before and after it as a minimum value and a maximum value, respectively.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The high-speed photothermographic material of the present invention and its image forming method will be described below in detail. The high-speed photothermographic material of the present invention has an image forming layer containing a non-photosensitive silver salt, a photosensitive silver halide, a nucleating agent and a binder on at least one surface of a support. A feature of the present invention is that the image forming layer contains one or more solid fine particles of a water-insoluble organic compound, and
The average particle size of the solid fine particles of each water-insoluble organic compound is 0.
It is less than 05 μm. According to the present invention having such characteristics, it is possible to reduce the exposure amount dependence of the character line width and to form a high quality image when thermally developing at a high speed.

In the present specification, the term "high-speed photothermographic material" refers to a photothermographic material for performing a heat development process at a line speed of 140 to 700 cm / min. When a heat development process is performed at such a high line speed using a conventional photothermographic material, the character line width greatly fluctuates and the image quality is poor. However, according to the high-speed photothermographic material of the present invention having the above characteristics, it is possible to form a high-quality image having a small variation in character line width, a small fog (Dmin) and a high maximum density (Dmax). . The high-speed photothermographic material of the present invention is preferably subjected to heat development at a line speed of 140 to 560 cm / min.

The image forming layer constituting the high-speed photothermographic material of the present invention contains at least a non-photosensitive silver salt, a photosensitive silver halide, a nucleating agent, and a binder. It may contain a wide variety of organic compounds, such as preparations, antifoggants, stabilizers, and the like. The image forming layer is
Including solid particulates of one or more water-insoluble organic compounds,
The water-insoluble organic compound may be any material contained in the image forming layer. The term “water-insoluble organic compound” as used herein means that the solubility in water at 25 ° C. is 0.1%.
% Or less of an organic compound. The solid fine particles of each water-insoluble organic compound contained in the image forming layer have an average particle diameter of less than 0.05 μm. The lower limit of the average particle diameter is not particularly limited, but the average particle diameter that can be substantially produced is about 0.005 to 0.01 μm. When the average particle diameter is 0.05 μm or more, when the line speed is increased and the thermal development is performed quickly, the variation of the character line width is still large,
It is not preferable in terms of commercial value. The average particle diameter described in the present specification is a value obtained by photographing with a transmission electron microscope 2000FX manufactured by JEOL Ltd. and calculating the equivalent diameter of a projected area circle.

The method for forming the image-forming layer having the above-mentioned characteristics is not particularly limited. First, a dispersion of solid fine particles of a water-insoluble organic compound is prepared, and this is used as another component constituting the image-forming layer. To form an image forming layer coating solution,
It is preferable that the coating solution is formed by applying the coating solution on a support and drying. The solid fine particle dispersion of the water-insoluble organic compound used here may be mixed with an appropriate solvent (water,
Using a known micronization means (for example, ball mill, vibrating ball mill, planetary ball mill, sand mill, colloid mill, jet mill, roller mill, microfluidizer) in the presence of a dispersing aid. Can be prepared. As the solvent, water is preferably used in an amount of 90% or more, more preferably 95% or more.

The solid fine particle dispersion of the water-insoluble organic compound used in the present invention is preferably formed into fine particles by media dispersion using a medium. Various beads such as glass beads, steel balls, ceramic beads, and polymer beads can be used as media.
The material of the beads is selected according to the viscosity and particle size of the slurry to be dispersed. The average particle size of the beads used in the present invention is preferably 300 μm or less, more preferably 200 μm.
m, more preferably 100 μm or less. The lower limit of the average particle size of the beads used is not particularly limited, but is usually about 30 μm from the viewpoint of handling. The particle size of the beads greatly affects the particle size of the resulting dispersion. To obtain a dispersion having a small particle size, it is important that the number of media, that is, the number of collisions, is large. If the average particle diameter of the beads is larger than 300 μm, even if the number of passes of the mill is increased or the dispersion conditions are devised, it is not possible to obtain a solid fine particle dispersion having a target average particle diameter of less than 0.05 μm. Have difficulty.

The dispersion of the solid fine particles of the organic compound is dissolved in an appropriate solvent using a dispersing agent, and then added to a poor solvent for the organic compound to precipitate fine crystals. It can also be prepared by using a method of controlling the pH, a method of first dissolving the organic compound by controlling the pH, and then changing the pH to perform microcrystallization. At this time, an organic solvent may be used as a solvent used for the coarse dispersion, and the organic solvent is usually removed after the completion of the fine particle formation. As the dispersing agent, any surfactant such as nonionic, anionic, cationic, and fluorine is appropriately used. Of these, anionic, nonionic and amphoteric surfactants are preferred, and anionic and / or nonionic surfactants are particularly preferred. Specifically, Japanese Patent Application Laid-Open No. Sho 62-170950
No. 5,380,644, etc., fluorine-containing polymer surfactants described in JP-A-60-24494
No. 5, JP-A-63-188135, etc .; fluorinated surfactants described in U.S. Pat. No. 3,885,965; polysiloxane-based surfactants described in JP-A-6-301140; Of polyalkylene oxides and anionic surfactants.

The high-speed photothermographic material of the present invention uses a non-photosensitive silver salt. It is preferable to use an organic silver salt as the non-photosensitive silver salt. The organic silver salt that can be used in the present invention is relatively stable to light, but at 80 ° C. or below in the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent. It is a silver salt that forms a silver image when heated as described above. The organic silver salt can be any organic material including a source of reducible silver ions. Silver salts of organic acids, especially (C10-C30, preferably 15-28
Silver salts of long chain fatty carboxylic acids are preferred. Also preferred are organic or inorganic silver salt complexes in which the ligand has a complex stability constant in the range of 4.0 to 10.0. The silver donor can preferably comprise about 5 to 70% by weight of the imaging layer. Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. Specific examples thereof include silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids, but are not limited thereto. 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 acid, silver tartrate, silver linoleate, silver butyrate and silver camphorate, mixtures thereof and the like can be mentioned.

In the present invention, it is preferable to use silver behenate having a silver behenate content of 75 mol% or more, and silver behenate content of 85 mol% or more. It is more preferable to use organic acid silver. Here, the content of silver behenate indicates the mole 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, the above-mentioned exemplified organic acid silver can be preferably used. The silver salt of an organic acid preferably used in the present invention is prepared by reacting a solution or suspension of an alkali metal salt of the above-mentioned organic acid (including a Na salt, a K salt and a Li salt) with silver nitrate. These preparation methods are described in paragraph [001] of Japanese Patent Application No. 11-104187.
9] to [0021] can be used.

The organic acid silver which is preferably used in the present invention is:
Alkali metal salts of organic acids shown above (Na salt, K salt,
It is prepared by reacting silver nitrate with a solution or suspension. Organic acid alkali metal salts are
It is obtained by treating the above organic acid with alkali.
The silver organic acid can be run batchwise or continuously in any public vessel. The stirring in the reaction vessel can be performed by any stirring method depending on the required properties of the particles. The silver salt of an organic acid can be prepared by gradually or rapidly adding an aqueous silver nitrate solution to a reaction vessel containing an alkali metal salt solution or suspension of an organic acid, or by preparing an organic acid prepared in advance in a reaction vessel containing a silver nitrate aqueous solution. A method of gradually or rapidly adding an alkali metal salt solution or suspension,
Any of the methods 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 can be preferably used.

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 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 first. The leading degree is preferably 0 to 50% by volume of the total addition amount, particularly preferably 0 to 25% by volume. Further, a method of adding while controlling the pH or silver potential of the reaction solution during the reaction as described in JP-A-9-127463 can 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. In addition, depending on the required characteristics of the particles, for example, the temperature in the reaction vessel can be arbitrarily set 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.

In the present invention, a method for preparing an organic silver salt by adding an aqueous solution of silver nitrate and a solution of an alkali metal salt of an organic acid into a sealing means for mixing a liquid can be preferably used. Specifically, Japanese Patent Application Hei 11
The method described in -203413 can be used. In the present invention, when preparing the organic acid silver,
A water-soluble dispersant can be added to the aqueous silver nitrate solution, the organic acid alkali metal salt solution, or the reaction solution. The kind and amount of the dispersant used here are described in paragraph [0] of Japanese Patent Application No. 11-115457.
052].

The organic acid silver used in the present invention is preferably prepared in the presence of a tertiary alcohol. As the tertiary alcohol, a compound having a total carbon number of 15 or less is preferable, and a compound having a total carbon number of 10 or less is particularly preferable. Preferred examples of the tertiary alcohol include tert-butanol, but the tertiary alcohol that can be used in the present invention is not limited to this. The tertiary alcohol used in the present invention may be added at any time during the preparation of the organic acid silver salt.
It is preferable to dissolve and use the alkali metal salt of the organic acid. Further, the tertiary alcohol used in the present invention is 0.01 to 1 in mass ratio to water as a solvent at the time of preparing the silver salt of an organic acid.
Although it can be used in the range of 0, it is preferable to use in the range of 0.03-1.

The shape of the organic silver salt which can be used in the present invention is not particularly limited.
It is less than 5 μm. The shape and size of the organic silver salt can be determined from a transmission electron microscope image of the organic silver salt dispersion. The organic silver salt used in the present invention is preferably desalted. The desalting method is not particularly limited, and a known method can be used. However, a known filtration method such as centrifugal filtration, suction filtration, ultrafiltration, and floc-forming water washing by a coagulation method can be preferably used. As for the method of ultrafiltration, the method described in Japanese Patent Application No. 11-115457 can be used.

In the present invention, in order to obtain a solid dispersion of an organic silver salt having a high S / N, a small particle size, and no aggregation, an organic silver salt which is an image forming medium and a photosensitive silver salt are substantially contained. Aqueous dispersions that do not contain water, for example, BEE INTER
Fine particles are preferably dispersed in an ultrahigh-pressure jet stream using an ultrahigh-pressure dispersion device such as DeBEE2000 manufactured by NATIONAL. These dispersing methods are described in Japanese Patent Application No. Hei.
Paragraph Nos. [0022] to 1-273531 of the specification
The method described in [0028] can be used. The organic silver salt solid fine particle dispersion used in the present invention preferably has a monodispersed particle size distribution. Specifically, the percentage (coefficient of variation) of the value obtained by dividing the standard deviation of the volume load average diameter by the volume load average diameter is 80% or less, more preferably 50%.
Or less, more preferably 30% or less.

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 mass, and particularly preferably 10 to 30% by mass.
It is preferable to use the above-mentioned dispersing aid, but it is preferable to use the dispersing aid in a minimum amount within a range suitable for minimizing the particle size, and 0.5 to 30% by mass, especially 1 to 30% by mass based on the organic silver salt.
A range of 15% by mass is preferred. The organic silver salt used in the present invention can be used in a desired amount.
m ² is preferred, and more preferably 1 to 3 g / m ² .

In the present invention, it is preferable to add a metal ion selected from Ca, Mg, Zn and Ag to the organic silver salt. Regarding the addition of a metal ion selected from Ca, Mg, Zn and Ag to an organic silver salt, it is preferable to add the metal ion in the form of a water-soluble metal salt which is not a halide. It is preferred to add in the form. The addition of a halide is not preferable 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 a halide. The timing of adding 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 organic silver salt,
The timing may be any time immediately before the application, such as immediately after the formation of the particles, before the dispersion, 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. C in the present invention
The amount of the metal ion selected from a, Mg, Zn and Ag is 10 ⁻³ to 1 per 1 mol of non-photosensitive organic silver.
It is preferably 0 ^-1 mol, particularly preferably 5 × 10 ^{-3 to} 5 × 10 ^-2 mol.

The high-speed photothermographic material of the present invention uses a photosensitive silver halide. The number average grain size of the photosensitive silver halide used in the present invention is 0.01 μm to 0.08 μm.
Is more preferable, and more preferably 0.02 μm to 0.08 μm.
m, more preferably 0.06 μm to 0.08 μm
m. The number average particle size is the upper limit of 0.08μ
If it is larger than m, the photographic performance after storage is adversely affected, which is not preferable, and the lower limit is 0.01 μm
Is from a manufacturing technology point of view. The number average grain size of the photosensitive silver halide prepared can be adjusted by selecting the grain formation temperature. In general,
The lower the grain formation temperature, the smaller the number average grain size of the photosensitive silver halide prepared. For example, in the following examples, photosensitive silver halide having a number average grain size of 0.10 μm to 0.06 μm was prepared by preparing at a grain formation temperature in the range of 45 ° C. to 30 ° C. When the silver halide grains are cubic or octahedral so-called normal crystals, the number average grain size referred to here is the sum of grain sizes for the number of grains, with the length of the edge of the silver halide grains as the grain size. Divided by the number of particles. Also,
When the silver halide grains are tabular grains, the diameter when converted into a circular image having the same area as the projected area of the main surface is calculated as the grain size. In the case where the crystal is not a normal crystal, for example, in the case of a spherical particle, a rod-shaped particle, or the like, the diameter of a sphere equivalent to the volume of the silver halide particle is calculated as the particle size. Dmin is determined by the silver halide content in the image forming layer.
Is high and Dmin is low. This is because if the silver amount is the same,
This is because the smaller the particle size, the larger the number of particles and the higher the heat development activity.

The shape of the silver halide grains is cubic,
Octahedral, tetradecahedral, tabular, spherical, rod-like, potato-like and the like can be mentioned. In the present invention, cubic particles or tabular particles are particularly preferable. The characteristics of the particle shape, such as the particle aspect ratio and the surface index, are the same as those described in paragraph [0225] of JP-A-11-119374. The distribution of the halogen composition may be uniform inside and on the surface of the silver halide grains, and the halogen composition may be changed stepwise or may be changed continuously. Further, silver halide grains having a core / shell structure can be preferably used. The structure is preferably 2-
Core / shell particles having a quintuple structure, more preferably a quaternary structure, can be used. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.

In the particle size distribution of the silver halide grains used in the present invention, the value of the monodispersity is 30% or less, preferably 1%.
-20%, and even 5-15%. Here, the monodispersity is defined as a percentage (%) (coefficient of variation) of a value obtained by dividing the standard deviation of the particle size by the average particle size. For the sake of convenience, the grain size of the silver halide grains is represented by a ridge length in the case of a cubic grain, and the other grains (octahedral, tetradecahedral, tabular, etc.) are calculated by the projected area circle equivalent diameter.

Photosensitive silver halide grains used in the present invention
Is a metal of Group VII or VIII of the Periodic Table or
Contains a metal complex. Group VII or VII of the periodic table
Preferably as the central metal of Group I metals or metal complexes
Rhodium, rhenium, ruthenium, osnium, iridium
Um. Particularly preferred metal complexes are (NH_Four)_ThreeRh
(H_TwoO) Cl_Five, K_TwoRu (NO) Cl_Five, K_ThreeIrC
l₆, K_FourFe (CN)₆It is. These metal complexes are one kind
Or two or more complexes of the same and different metals.
You may use together. The preferred content is 1 to 1 mole of silver.
× 10^-9Mol ~ 1 x 10 ^-3Molar range is preferred, 1 ×
10^-8Mol ~ 1 x 10^-FourA molar range is more preferred. Ingredient
The structure of a physical metal complex is disclosed in JP-A-7-225449.
Can use a metal complex having the structure described in
Wear. Regarding the types and addition methods of these heavy metals,
Paragraph Nos. [0227] to 11-119374
[0240].

The photosensitive silver halide grains can be desalted by a water washing method known in the art such as a noodle method or a flocculation method, but may or may not be desalted in the present invention. . The photosensitive silver halide emulsion used in the present invention is preferably chemically sensitized. Regarding the chemical sensitization, see paragraph [0] of JP-A-11-119374.
242] to [0250]. A thiosulfonic acid compound may be added to the silver halide emulsion used in the present invention by a method described in European Patent Publication No. EP 293,917.

As the gelatin contained in the photosensitive silver halide used in the present invention, a low molecular weight gelatin is used in order to maintain a good dispersion state of the photosensitive silver halide emulsion in an organic silver salt-containing coating solution. Is preferred. The low molecular weight gelatin has a molecular weight of 500 to 60,000, preferably 1,000 to 40,000. These low molecular weight gelatins may be used at the time of particle formation or at the time of dispersion after desalting treatment, but are preferably used at the time of dispersion after desalting treatment. When forming particles, use normal gelatin (molecular weight of about 100,000),
Low-molecular-weight gelatin may be used at the time of dispersion after desalting. The concentration of the dispersion medium can be 0.05 to 20% by mass, but a concentration range of 5 to 15% by mass is preferable for handling. As the type of gelatin, alkali-treated gelatin is usually used, but modified gelatin such as acid-treated gelatin and phthalated gelatin can also be used. In the present invention, only one type of silver halide emulsion may be used, or two or more types thereof (for example, those having different average grain sizes,
Those having 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 to 0.5 mol, more preferably 0.02 mol to 1 mol of the organic silver salt.
0.3 mol is more preferable, and 0.03 mol to 0.25 mol is particularly preferable. About the mixing method and mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the silver halide particles and the organic silver salt which have been respectively prepared are mixed with a high-speed stirrer, a ball mill, a sand mill, a colloid mill, a vibration mill, There is a method of mixing with a homogenizer or the like, 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 it is sufficiently obtained. In addition, mixing two or more kinds of aqueous dispersions of organic silver salts and two or more kinds of aqueous dispersions of photosensitive silver salts is a preferable method for adjusting photographic characteristics.

A sensitizing dye can be used in the high-speed photothermographic material of the present invention. As a sensitizing dye, a sensitizing dye capable of spectrally sensitizing a silver halide particle in a desired wavelength region when adsorbed on the silver halide particle, and a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of an exposure light source is advantageously used. You can choose. For example, dyes that spectrally sensitize a wavelength region of 550 nm to 750 nm include dyes represented by the general formula (II) in JP-A-10-186572, and specifically, II-6 and II-7. , II-14, II-15, II-18,
The dyes II-23 and II-25 can be exemplified as preferred dyes. Dyes that spectrally sensitize the wavelength region of 750 to 1400 nm are described in JP-A-11-1193.
No. 74, a dye represented by the general formula (I),
Specifically, (25), (26), (30), (32),
The dyes (36), (37), (41), (49) and (54) can be exemplified as preferred dyes. Further, as a dye forming a J-band, US Pat. Nos. 5,510,236 and 3,871,887.
JP-A-2-9613
No. 1 and JP-A-59-48753 can be exemplified as preferred dyes.
These sensitizing dyes may be used alone or in combination of two or more. Regarding the addition of these sensitizing dyes,
The paragraph number [010] of JP-A-11-119374 is disclosed.
6] can be added by the method described in
In particular, it is not limited to this method. The addition amount of the sensitizing dye in the present invention can be a desired amount in accordance with the sensitivity and the performance of fog, but is preferably 10 ^-6 to 1 mol per mol of silver halide in the photosensitive layer, and more preferably. Is 10 ^-4 to 10 ^-1 mol.

In the present invention, a supersensitizer can be used to improve spectral sensitization efficiency. Examples of the supersensitizer used in the present invention include European Patent Publication EP 587,33.
No. 8, US Pat. Nos. 3,877,943 and 4,873,184, heteroaromatic or aliphatic mercapto compounds, heteroaromatic disulfide compounds, stilbene, Hydrazine,
Examples include compounds selected from triazines. Particularly preferred supersensitizers include heteroaromatic mercapto compounds and heteroaromatic disulfide compounds disclosed in JP-A-5-341432, and general formula (I) or (II) in JP-A-4-18239. A compound represented by
A stilbene compound represented by the general formula (I) in JP-A-10-111543 and a compound represented by the general formula (I) in JP-A-11-109947. Specifically, compounds of M-1 to M-24 in JP-A-5-341432 and d-1) to d in JP-A-4-18239A are disclosed.
-14), the compounds of SS-01 to SS-07 of JP-A-10-111543, and the compounds of JP-A-11-109
5,47,31,32,37,38,41-45,
51 to 53. These supersensitizers are added in an amount of 10 ^-4 to 1 per mol of silver halide in the emulsion layer.
It is preferably in the range of 0.1 mol per mol of silver halide.
The range of 001 to 0.3 mol is more preferable.

Next, the nucleating agent used in the high-speed photothermographic material of the present invention will be described. The type of nucleating agent used in the present invention is not particularly limited, but as a preferable nucleating agent, a hydrazine derivative represented by the formula (H) described in Japanese Patent Application No. 11-87297 (specifically, Hydrazine derivatives described in Tables 1 to 4), JP-A-10-10672, JP-A-10-161270 and JP-A-10-106.
62898, JP-A-9-304870, JP-A-9-304872, JP-A-9-304871
JP, JP-A-10-31282, US Pat. No. 5,496,695, European Patent Publication EP 74
All hydrazine derivatives described in JP-A No. 1,320 can be mentioned. Further, substituted alkene derivatives, substituted isoxazole derivatives and specific acetal compounds represented by the formulas (1) to (3) described in Japanese Patent Application No. 11-87297, more preferably the formula described in the same specification. The cyclic compound represented by (A) or the formula (B), specifically, the compounds 1 to 72 described in Chemical Formulas 8 to 12 of the same specification can also be used. Further, a plurality of these nucleating agents may be used in combination.

The nucleating agent may be water or a suitable organic solvent,
For example, alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone,
Methyl ethyl ketone), dimethylformamide, dimethylsulfoxide, methylcellosolve and the like can be used. In addition, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone is dissolved by a well-known emulsification dispersion method. Then, an emulsified dispersion can be prepared and used mechanically. Alternatively, the nucleating agent 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. The nucleating agent is
It may be added to any layer on the image forming layer side with respect to the support, but is preferably added to the image forming layer or a layer adjacent thereto. The addition amount of the nucleating agent is preferably 1 × 10 ⁻⁶ to 1 mol per 1 mol of silver, and 1 × 10 ^{−5 to} 5 × 10 5
^-1 mol is more preferred, and 2 × 10 ^-5 to 2 × 10 ^-1 mol is most preferred.

In addition to the above compounds, US Pat.
545,515, 5,635,339 and 5,654,130, International Publication WO
97/34196, US Pat. No. 5,686,22.
No. 8 or the compound described in JP-A-11-1
19372, Japanese Patent Application No. 9-309813,
JP-A-11-119373, JP-A-11-109
Compounds described in JP-A-564-564, JP-A-11-95365, JP-A-11-95366, and JP-A-11-149136 may be used.

In the present invention, a high-contrast accelerator can be used in combination with the nucleating agent for forming an ultra-high-contrast image. For example, amine compounds described in U.S. Pat. No. 5,545,505, specifically AM-1 to AM-5,
Hydroxamic acids described in U.S. Pat. No. 5,545,507, specifically HA-1 to HA-11, acrylonitriles described in U.S. Pat. No. 5,545,507, specifically CN-1 to CN-13, hydrazine compounds described in U.S. Pat. No. 5,558,983, specifically, CA-1 to CA-6, JP-A-9-297.
No. 368, onium salts, specifically, A-
1 to A-42, B-1 to B-27, C-1 to C-14 and the like can be used. In a photothermographic material having a non-photosensitive organic silver salt, a photosensitive silver halide and a binder, formic acid or formate is a strong fogging substance. In the present invention, the content of formic acid or formate on the side having the image forming layer is preferably 5 mmol or less, more preferably 1 mmol or less per 1 mol of silver.

In the high-speed photothermographic material of the present invention, it is preferable to use an acid formed by hydration of diphosphorus pentoxide or a salt thereof in combination 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) and the like can be mentioned. 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, and ammonium hexametaphosphate. The acid or salt thereof formed by hydration of diphosphorus pentoxide, which can be preferably used in the present invention, is added to the image forming layer or the binder layer adjacent thereto in that a desired effect is exhibited in a small amount. Use amount of the oxidizing acid or salt thereof formed by hydration of diphosphorus (coating amount per photographic material 1 m ²⁾ may be a desired amount depending on the performance such as sensitivity and fog, but, 0.1 to 500 mg / m ² is preferred, and 0.5
-100 mg / m ² is more preferred.

The high-speed photothermographic material of the present invention preferably contains a reducing agent for an organic silver salt. The reducing agent for the organic silver salt is any substance that reduces silver ions to metallic silver, preferably an organic substance. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful, but hindered phenol reducing agents are preferred. The reducing agent is used in an amount of 5 to 50 per mol of silver on the surface having the image forming layer.
%, More preferably 10 to 40 mol%. The layer to which the reducing agent is added may be any layer on the image forming layer side with respect to the support. When added to layers other than the image forming layer, 10 to 5
It is preferred to use as much as 0 mol%. Further, the reducing agent may be a so-called precursor which is derivatized so as to function effectively only during development.

A wide range of reducing agents can be used in the high-speed photothermographic material of the present invention using an organic silver salt. For example, JP-A-46-6074, JP-A-47-1238, JP-A-47-33621, and JP-A-49-46427.
JP, JP-A-49-115540, JP-A-50-143
Nos. 34, 50-36110, 50-14
Nos. 7711, 51-32632 and 51-
Nos. 1023721, 51-32424, 51-51933, 52-84727,
JP-A-55-108654, JP-A-56-146133, JP-A-57-82828, and JP-A-57-82829
JP, JP-A-6-3793, U.S. Pat.
Nos. 79,426, 3,751,252, 3,751,255, and 3,763.
Nos. 1,270, 3,782,949, 3,839,048, 3,92
No. 8,686, 5,464,738, German Patent 2,321,328, European Patent Publication EP 692,732 and the like. Can be used. Amide oximes such as, for example, phenylamide oxime, 2-thienylamide oxime and p-phenoxyphenylamide oxime;
Azines such as, for example, 4-hydroxy-3,5-dimethoxybenzaldehyde azine; aliphatic carboxylic acid arylhydrazides, such as a combination of 2,2'-bis (hydroxymethyl) propionyl-β-phenylhydrazine and ascorbic acid, and ascorbic acid A combination of polyhydroxybenzene with hydroxylamine, reductone and / or hydrazine (for example, a combination of hydroquinone with 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 azines with sulfonamidophenols (eg, phenothiazine 2,6-dichloro-4-benzenesulfonamidophenol); 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; of bis-β-naphthol and 1,3-dihydroxybenzene derivatives (such as 2,4-dihydroxybenzophenone or 2 ′, 4′-dihydroxyacetophenone). 5-pyrazolone such as 3-methyl-1-phenyl-5-pyrazolone; dimethylaminohexose reductone, anhydrodihydroaminohexose reductone and anhydrodihydropiperidone hexose reductone, as exemplified in the combination; Reducton; 2,6
-Sulfonamide phenol reducing agents such as dichloro-4-benzenesulfonamidophenol and p-benzenesulfonamidophenol; 2-phenylindane-
1,2-dione and the like; 2,2-dimethyl-7-tert
Chromans such as -butyl-6-hydroxychroman;
2,6-dimethoxy-3,5-dicarbethoxy-1,
1,4-dihydropyridines such as 4-dihydropyridine; bisphenols (for example, bis (2-hydroxy-
3-tert-butyl-5-methylphenyl) methane,
2,2-bis (4-hydroxy-3-methylphenyl)
Propane, 4,4-ethylidene-bis (2-tert-
Butyl-6-methylphenol), 1,1, -bis (2
-Hydroxy-3,5-dimethylphenyl) -3,5
5-trimethylhexane and 2,2-bis (3,5-
Dimethyl-4-hydroxyphenyl) propane, etc.);
Ascorbic acid derivatives (eg, 1-ascorbyl palmitate, ascorbyl stearate, etc.); and aldehydes and ketones such as benzyl and biacetyl; 3-pyrazolidone and certain indane-1,3
Diones; chromanols (such as tocopherol); Particularly preferred reducing agents are bisphenol, chromanol. When a reducing agent is used in the present invention,
An aqueous solution, an organic solvent solution, a powder, a solid fine particle dispersion, an emulsified dispersion and the like may be added by any method. Dispersion of solid fine particles can be 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,
Roller mill). When dispersing the solid fine particles, a dispersing aid may be used.

When an additive known as a "toning agent" for improving an image is included, the optical density may increase.
The toning agent may also be advantageous in forming a black silver image. The color-toning agent is preferably contained in the layer on the image forming layer side with respect to the support in an amount of 0.1 to 50% mol, more preferably 0.5 to 20% mol, per mol of silver. Further, the color tone agent may be a so-called precursor which is derivatized so as to function effectively only during development. A wide range of color toning agents can be used in the high-speed photothermographic material of the present invention using an organic silver salt. For example,
JP-A-46-6077, JP-A-47-10282, JP-A-49-5019, JP-A-49-5020, JP-A-49-91215, JP-A-49-91215, and JP-A-50-2524. Nos. 50-32927 and 50-67132 and 50-67641.
JP-A-50-114217, JP-A-51-322
No. 3, No. 51-27923, No. 52-147
Nos. 88, 52-99813 and 53-10
No. 20, No. 53-76020, No. 54-15
Nos. 6524, 54-156525, 61
183,642, JP-A-4-56848,
JP-B-49-10727, JP-B-54-20333, U.S. Pat. Nos. 3,080,254, 3,446,648, and 3,782,941.
No. 4,123,282, No. 4,123,282
No. 510,236, British Patent 1,380,79
No. 5, Belgian Patent No. 841,910 and the like can be used. Specific examples of the toning agent include phthalimide and N-hydroxyphthalimide; succinimide, pyrazolin-5-one,
And cyclic imides such as quinazolinone, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione; naphthalimides (eg, N-hydroxy-1,8-naphthalimide A) cobalt complex (eg, cobalt hexamine trifluoroacetate); 3-mercapto-1,
2,4-triazole, 2,4-dimercaptopyrimidine, 3-mercapto-4,5-diphenyl-1,2,4
-Triazole and 2,5-dimercapto-1,3,
Mercaptans exemplified by 4-thiadiazole; N-
(Aminomethyl) aryldicarboximides, such as (N, N-dimethylaminomethyl) phthalimide and N, N- (dimethylaminomethyl) -naphthalene-
2,3-dicarboximide); and blocked pyrazoles, isothiuronium derivatives, and certain photobleaching agents (eg, N, N'-hexamethylenebis (1-carbamoyl-3,5-dimethylpyrazole), 1,8 −
(3,6-diazaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) -benzothiazole; and 3-ethyl-5-[(3-ethyl-2-benzothiazolinylidene)
-1-methylethylidene] -2-thio-2,4-oxazolidinedione; phthalazinone, a phthalazinone derivative or metal salt, or 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone And derivatives thereof such as 2,3-dihydro-1,4-phthalazinedione; combinations of phthalazinone with phthalic acid derivatives such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride; Phthalazine, phthalazine derivative (for example, 4-
(1-naphthyl) phthalazine, 6-chlorophthalazine,
Derivatives such as 5,7-dimethoxyphthalazine, 6-isobutylphthalazine, 6-tert-butylphthalazine, 5,7-dimethylphthalazine, and 2,3-dihydrophthalazine) or metal salts; phthalazine and its derivatives And phthalic acid derivatives such as phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride; quinazolinedione, benzoxazine or naphthoxazine derivatives; Rhodium complexes that also function as a source of halide ions for silver halide formation, such as ammonium hexachlororhodate (III), rhodium bromide, rhodium nitrate and potassium hexachlororhodate (III); inorganic peroxides and peroxides Sulfates, for example, disulfide peroxide Ammonium and hydrogen peroxide; 1,3-benzoxazine-2,4-dione, 8-
Methyl-1,3-benzoxazine-2,4-dione and 6-nitro-1,3-benzoxazine-2,4-
Benzoxazine-2,4-diones such as diones; pyrimidines and asymmetric-triazines (eg, 2,4-dihydroxypyrimidine, 2-hydroxy-4-aminopyrimidine, etc.), azauracil, and tetraazapentalene derivatives (eg, 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) and the like.

In the present invention, a toning agent is disclosed in Japanese Patent Application No.
A phthalazine derivative represented by the general formula (F) described in JP 13487 is preferably used. Specifically, A-1 to A-10 described in the same specification are preferably used.
The color tone agent may be added by any method such as a solution, a powder, and a solid fine particle dispersion. Dispersion of solid fine particles can be performed by a known means of micronization (eg, ball mill, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.).
Done in When dispersing the solid fine particles, a dispersing aid may be used.

The surface pH of the high-speed photothermographic material of the present invention before thermal development is preferably 6.0 or less, more preferably 5.5 or less. The lower limit is not particularly limited, but is about 3. Adjustment of the pH of the film surface is performed by using an organic acid such as a phthalic acid derivative, a non-volatile acid such as sulfuric acid,
The use of a volatile base such as ammonia can increase the film surface p.
It is preferable from the viewpoint of reducing H. In particular, ammonia is preferable in achieving a low film surface pH since ammonia is easily volatilized and can be removed before the application step and the heat development.
The method for measuring the film surface pH is described in Japanese Patent Application No. 11-87297.
No. [0123] in the specification.

In the high-speed photothermographic material of the present invention, the silver halide emulsion and / or the organic silver salt are further protected against the formation of additional fog by an antifoggant, a stabilizer and a stabilizer precursor. In addition, it is possible to stabilize against a decrease in sensitivity during storage in inventory. Suitable antifoggants which can be used alone or in combination,
Stabilizers and stabilizer precursors are disclosed in U.S. Pat. No. 2,131,
Nos. 038 and 2,694,716; thiazonium salts described in US Pat. No. 2,886,43.
No. 7, 244, 605, Azaindene, U.S. Pat. No. 2,728,663, mercury salt, U.S. Pat. No. 3,287,135. Urazole, US Patent No. 3,235,6
No. 52, sulfocatechol, British Patent No. 6
Oxime, nitrone, nitroindazole described in US Pat. No. 23,448, polyvalent metal salt described in US Pat. No. 2,839,405, US Pat. No. 3,220,83.
No. 9,566,263 and U.S. Pat. Nos. 2,597,
No. 915, palladium, platinum and gold salts,
U.S. Patent Nos. 4,108,665 and 4,104,665;
No. 442,202, halogen-substituted organic compounds described in U.S. Pat. Nos. 4,128,557 and 4,137,079, and 4,138,365.
And the phosphorus compounds described in US Pat. No. 4,411,985.

The high-speed photothermographic material of the present invention may contain benzoic acids for the purpose of increasing the sensitivity and preventing fogging. The benzoic acid used in the present invention may be any benzoic acid derivative, and a preferred example is US Pat.
Nos. 84,939, 4,152,160, JP-A-9-329,863, and 9-32986.
No. 4, JP-A-9-28637, and the like. The benzoic acid may be added to any layer of the high-speed photothermographic material, but is preferably added to the layer on the image forming layer side with respect to the support, more preferably to the organic silver salt-containing layer. The addition of benzoic acids may be performed at any step in the preparation of the coating solution, and when the benzoic acid 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, but the coating is performed after the preparation of the organic silver salt. Immediately before is preferred. 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 1 × 10 ⁻⁶ mol / mol silver.
It is preferably 2 mol, more preferably 1 × 10 ⁻³ mol to 0.5 mol. Although not required to practice the invention,
It may be advantageous to add mercury (II) salts as antifoggants to the image forming layer. Preferred mercury (II) salts for this purpose are mercury acetate and mercury bromide. The amount of mercury used in the present invention is preferably from 1 × 10 ⁻⁹ mol to 1 × 10 ⁻³ mol, more preferably from 1 × 10 ⁻⁸ mol to 1 × 10 ⁻⁴ per mol of the coated silver. Range of moles.

The antifoggant particularly preferably used in the present invention is an organic halide.
No. 119624, No. 50-120328, No. 51-121332, No. 54-58022, No. 56-70543, No. 56-99335, No. 59-90842, No. 61-12964.
No. 2, JP-A-62-129845, and JP-A-6-2
JP 08191, JP 7-5621, JP 7-27
No. 81, 8-15809, U.S. Pat.
Compounds disclosed in 340,712, 5,369,000, and 5,464,737 are exemplified. Japanese Patent Application No. 11-87297
The hydrophilic organic halide represented by the formula (P) described in the specification is preferably used as an antifoggant. Specifically, (P-1) to (P-118) described in the same specification
Is preferably used. The amount of organic halide added is
Mol amount per mol Ag (mol / mol Ag)
And preferably 1 × 10 ^{−5 to 2} mol / molA
g, more preferably 5 × 10 ^{−5 to 1} mol / molA
g, more preferably 1 × 10 ^{-4 to} 5 × 10 ^-1 mol / g.
molAg. These may be used alone or in combination of two or more.

Also, Japanese Patent Application No. 11-87297 describes
Of the salicylic acid derivative represented by the formula (Z) described above
It is preferably used as a stopping agent. Specifically, the same specification
(A-1) to (A-60) described in are preferably used.
You. The amount of the salicylic acid derivative represented by the formula (Z) is:
Mol amount per mol Ag (mol / mol Ag)
, Preferably 1 × 10^-Five~ 5 × 10^-1mol /
molAg, more preferably 5 × 10^-Five~ 1 × 10^-1m
ol / mol Ag, more preferably 1 × 10 ^-Four~ 5x
10^-2mol / mol Ag. These are only one kind
They may be used or two or more of them may be used in combination. Preferred for the present invention
Formalin scavenge used as antifoggant
Is effective, for example, Japanese Patent Application No. 11-23995.
Compound represented by formula (S) described in the specification and examples thereof
Compounds (S-1) to (S-24).

The antifoggant used in the present invention may be water or a suitable organic solvent such as alcohols (methanol,
It can be used by dissolving in ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethylsulfoxide, methylcellosolve and the like. In addition, dibutyl phthalate,
Oils such as tricresyl phosphate, glyceryl triacetate or diethyl phthalate, dissolved using an auxiliary solvent such as ethyl acetate or cyclohexanone,
An emulsified dispersion can be prepared and used mechanically. Alternatively, the powder can be dispersed in water by a ball mill, a colloid mill, a sand grinder mill, a Menton-Gaulin, a microfluidizer or an ultrasonic wave by a method known as a solid dispersion method.
The antifoggant used in the present invention may be added to the layer on the image forming layer side with respect to the support, that is, the image forming layer or any other layer on this layer side. Is preferably added. The image forming layer is a layer containing a reducible silver salt (organic silver salt), and is preferably an image forming layer further containing a photosensitive silver halide.

The high-speed photothermographic material of the present invention contains a mercapto compound, a disulfide compound and a thione compound for the purpose of suppressing or accelerating the development to control the development, and improving the preservability before and after the development. be able to. When a mercapto compound is used in the present invention, any structure may be used, but Ar-SM, Ar
Those represented by -SS-Ar are preferred. In the formula, M is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring or a condensed aromatic ring having at least one atom of nitrogen, sulfur, oxygen, selenium or tellurium. Preferably, the heteroaromatic ring is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, pyridazine , Pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring includes, for example, halogen (for example, Br and Cl), hydroxy, amino, carboxy, alkyl (for example, having 1 or more carbon atoms, preferably 1 to
4), alkoxy (for example, having 1 or more carbon atoms, preferably 1 to 4) and aryl (which may have a substituent)
And a substituent selected from the group consisting of:
Examples of the mercapto-substituted heteroaromatic compound include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole, 6-ethoxy-2-mercaptobenzothiazole, 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-hydrokilocy-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-mercapto Tetrazole, 3- (5-mercaptotetrazole) -sodium benzenesulfonate, N-methyl-
Examples include N ′-{3- (5-mercaptotetrazolyl) phenyl} urea, 2-mercapto-4-phenyloxazole, and the like, but the invention is not limited thereto. The amount of the mercapto compound to be added is preferably in the range of 0.0001 to 1.0 mol per mol of silver in the image forming layer, more preferably 0.001 to 0.3 mol per mol of silver. It is.

The high-speed photothermographic material of the present invention has an image forming layer containing an organic silver salt, a reducing agent and a photosensitive silver halide on a support, and at least one protective layer is formed on the image forming layer. Preferably, a layer is provided. Further, the high-speed photothermographic material of the present invention preferably has at least one back layer on the side opposite to the image forming layer (back surface) with respect to the support, and includes the image forming layer, the protective layer, and the back layer. Polymer latex is used as a binder.
By using a polymer latex for these layers, aqueous coating using a solvent (dispersion medium) containing water as a main component becomes possible, which is advantageous in terms of environment and cost, and causes wrinkles during thermal development. A high-speed photothermographic material can be obtained. Further, by using a support which has been subjected to a predetermined heat treatment, a high-speed photothermographic material having a small dimensional change before and after thermal development can be obtained.

It is preferable to use the polymer latex described below as the binder used in the present invention. At least one of the image forming layers containing the photosensitive silver halide of the high-speed photothermographic material of the present invention is preferably an image forming layer using the polymer latex described below in an amount of 50% by mass or more of the total binder. Further, the polymer latex may be used not only for the image forming layer but also for a protective layer or a back layer. Particularly, when the high-speed photothermographic material of the present invention is used for printing in which dimensional change is a problem, the protective layer or It is preferable to use a polymer latex also for the back layer. However, the "polymer latex" referred to here is a polymer in which a water-insoluble hydrophobic polymer is 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 the 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 (Taira Okuda, edited by Hiroshi Inagaki, published by Kobunshi Kankokai (197
8))), "Applications of Synthetic Latex (Edited by Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, Polymer Publishing Association (19)
93)) "," Synthesis of Synthetic Latex (Souichi Muroi, published by Kobunshi Kankokai (1970)) "and the like. The average particle size of the dispersed particles is preferably in the range of about 1 to 50,000 nm, more preferably about 5 to 1,000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.

The polymer latex used in the present invention may be a so-called core / shell type latex other than a 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. The glass transition temperature (Tg) of the polymer latex preferably used for the binder used in the present invention is different between the protective layer, the back layer and the image forming layer. The temperature of the image forming layer is preferably from -30 to 40 ° C. in order to promote the diffusion of useful photographic materials 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 ° C, more preferably about 0 ° C to 70 ° C. 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) which is also called a plasticizer and lowers the minimum film forming temperature of the polymer latex. ) "
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 the like.
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 number average molecular weight of the polymer is preferably 5,000 to 1,000,000, and more preferably 10,000 to 100,000. If the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and if it is too large, the film-forming properties are poor, which is not preferable.

Specific examples of the polymer latex used as a binder for the image forming layer of the high-speed photothermographic material of the present invention include a methyl methacrylate / ethyl acrylate / methacrylic acid copolymer latex and a methyl methacrylate / butadiene / itaconic acid copolymer latex. Latex of a copolymer of ethyl acrylate / methacrylic acid, 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, vinylidene chloride / ethyl acrylate / acrylonitrile / Such as latex of methacrylic acid copolymers. More specifically, methyl methacrylate / ethyl acrylate / methacrylic acid = 3
3.5 / 50 / 16.5 (% by mass) copolymer latex, methyl methacrylate / butadiene / itaconic acid = 47.5 / 47.5 / 5 (% by mass) copolymer latex, ethyl acrylate / methacrylic acid = 95 / 5
(% By mass) of a copolymer latex.
Such polymers are also commercially available, for example, Sebian A-4635,46 as an example of an acrylic resin.
583, 4601 (all manufactured by Daicel Chemical Industries, Ltd.),
Nipol LX811, 814, 821, 820, 8
57 (Nippon Zeon Co., Ltd.), VONCORT-R
As polyester resins such as 3340, R3360, R3370, 4280 (all manufactured by Dainippon Ink and Chemicals, Inc.), FINETEX ES650, 611, 675,
850 (all manufactured by Dainippon Ink and Chemicals, Inc.), WD-si
ze, WMS (all manufactured by Eastman Chemical Co., Ltd.) such as HYDRAN AP10, 2
Rubber-based resins such as 0, 30, 40 (all manufactured by Dainippon Ink and Chemicals, Inc.) such as LACSTAR 7310K,
3307B, 4700H, 7132C (all manufactured by Dainippon Ink and Chemicals, Inc.), Nipol LX410, 430,
435, 438C (both manufactured by Nippon Zeon Co., Ltd.); vinyl chloride resins such as G351 and G576 (both manufactured by Nippon Zeon Co., Ltd.);
02, L513 (from Asahi Kasei Corporation), Aron D
7020, D504, D5071 (Mitsui Toatsu Co., Ltd.
Chemical Pearl S12 as an olefin resin
And SA100 (all manufactured by Mitsui Petrochemical Co., Ltd.). These polymers may be used alone or as a mixture of two or more as necessary.

The image forming layer contains 50% by mass of the total binder.
As the above, the above-mentioned polymer latex is preferably used, and it is more preferable to use the above-mentioned polymer latex as 70% by mass or more. That is, 50% by mass or more, preferably 70% by mass or more of the total binder of the image forming layer is a polymer latex having a glass transition temperature of -30C to 40C. If necessary, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, or hydroxypropylmethylcellulose may be added to the image forming layer in a range of 50% by mass or less of the whole binder. The amount of these hydrophilic polymers to be added is preferably 30% by mass or less, more preferably 15% by mass or less of the total binder in the image forming layer.

The image forming layer is preferably prepared by applying an aqueous coating solution and then drying. However, the term "aqueous" as used herein means that 60% by mass or more of the solvent (dispersion medium) of the coating liquid is water. Components other than water in the coating solution are methyl alcohol, ethyl alcohol, isopropyl alcohol,
Water-miscible organic solvents such as methyl cellosolve, ethyl cellosolve, dimethylformamide, and 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. (The numbers represent mass%.) The total binder amount of the image forming layer is 0.2 to 30 g / m ² ,
More preferably, the range is 1 to 15 g / m ² . A crosslinking agent for crosslinking and a surfactant for improving coating properties may be added to the image forming layer.

Further, as binders for the protective layer, paragraphs [0025] to [0025] of Japanese Patent Application No. 11-6872 can be used.
A combination of polymer latexes having different I / O values obtained by dividing the inorganic value based on the organic conceptual diagram described in [0029] by the organic value can be preferably used. In the present invention, if necessary, the plasticizers (eg, benzyl alcohol, 2,2,4-trimethylpentanediol-1) described in paragraphs [0021] to [0025] of Japanese Patent Application No. 11-143058 may be used. , 3-monoisobutyrate, etc.)
Can be added to control the film formation temperature. Further, as described in paragraphs [0027] to [0028] of Japanese Patent Application No. 11-6872, a hydrophilic polymer may be added to a polymer binder, and a water-miscible organic solvent may be added to a coating solution. .

Each of the layers is described in Japanese Patent Application No. 10-1996.
No. 26, paragraphs [0023] to [0041] of the first polymer latex into which a functional group is introduced, a crosslinking agent having a functional group capable of reacting with the first polymer latex, and / or a second polymer latex. Polymer latex can also be used. The above functional group is a carboxyl group,
Hydroxyl group, isocyanate group, epoxy group, N-
The crosslinking agent such as a methylol group or an oxazolinyl group is selected from an epoxy compound, an isocyanate compound, a blocked isocyanate compound, a methylol compound, a hydroxy compound, a carboxyl compound, an amino compound, an ethyleneimine compound, an aldehyde compound, and a halogen compound. Specific examples of the cross-linking agent include hexamethylene isocyanate, duranate WB40-80D, WX-1741 (manufactured by Asahi Kasei Corporation), Baihijur 3100 (manufactured by Sumitomo Bayer Urethane Co., Ltd.), and Takenate WD725 (Takeda Pharmaceutical Co., Ltd.) Aquatate 100, 200 (manufactured by Nippon Polyurethane Co., Ltd.), water-dispersible polyisocyanate described in JP-A-9-160172; Sumitex Resin M-3 (Sumitomo Chemical Industries, Ltd.) as an amino compound Made);
Examples of the epoxy compound include denacol EX-614B (manufactured by Nagase Kasei Kogyo Co., Ltd.); examples of the halogen compound include sodium 2,4-dichloro-6-hydroxy-1,3,5-triazine.

The total amount of the binder for the image forming layer is from 0.2 to
30 g / m ^2, more preferably in the range of 1.0~15g / m ^2. The total binder amount for the protective layer is 0.2 to 1
0.0 g / m ² , more preferably 0.5 to 6.0 g / m ²
Is preferable. The total amount of binder for the back layer is 0.
01 to 10.0 g / m ² , more preferably 0.05 to
A range of 5.0 g / m ² is preferred. Each of these layers
There may be more than one layer. When the image forming layer has two or more layers, it is preferable to use a polymer latex as a binder for all the layers. Further, the protective layer is a layer provided on the image forming layer, and there may be two or more layers. However, it is preferable that at least one layer, particularly the outermost protective layer, use a polymer latex. The back layer is a layer provided on the undercoat layer on the back surface of the support. In some cases, two or more back layers are present.
It is preferred to use a polymer latex for the layer, especially the outermost back layer.

[0061] The term "slip agent" as used herein means a compound which, when present on the surface of an object, reduces the coefficient of friction on the surface of the object as compared to the absence thereof. The type is not particularly limited. Examples of the slip agent used in the present invention include paragraphs [0061] to [0061] of JP-A-11-84573.
[0064] and the compounds described in paragraphs [0049] to [0062] of Japanese Patent Application No. 11-106881 can be exemplified. As specific examples of preferred slip agents,
Cellozol 524 (main component carnauba wax), Polylon A, 393, H-481 (main component polyethylene wax), Himicron G-110 (main component ethylene bisstearic acid amide), Himicron G-270 (main component stearic acid amide) (The above is Chukyo Yushi Co., Ltd.)
Ltd.), etc. _{W-1 C 16 H 33 -O} -SO 3 Na W-2 C 18 H 37 -O-SO 3 Na and the like. The amount of the slip agent used is 0.1 to 50% by mass of the binder amount of the additive layer, preferably 0.5 to 50% by mass.
30% by mass.

In the present invention, Japanese Patent Application No. Hei 10-34656 is disclosed.
No. 1, Japanese Patent Application No. 11-106881, the preliminary heating section is conveyed by an opposing roller, and the heat development processing section is driven by a roller on the side having the image forming layer.
In the case of using a heat development processing apparatus which conveys the opposite back surface by sliding it to a smooth surface, the outermost surface layer on the side having the image forming layer of the heat development image recording material at the development processing temperature and the outermost surface layer on the back surface Is 1.5 or more, and there is no particular upper limit, but it is about 30. Further, μb is 1.0 or less, preferably 0.05 to 0.8. This value is obtained by the following equation. Ratio of friction coefficient = dynamic friction coefficient (μe) between roller member of heat developing machine and surface having image forming layer / dynamic friction coefficient (μb) of smooth surface member and back surface of heat developing machine (heat) The lubricating property of the outermost surface layer on the surface having the heat development processing machine member and the image forming layer and / or the opposite surface thereof can be adjusted by including a slipping agent in the outermost surface layer and changing the amount of addition. it can.

On both sides of the support, JP-A-64-2054
No. 4, JP-A-1-180537, JP-A-1-18037
No. 209443, JP-A-1-285939,
JP-A-1-296243, JP-A-2-24649
JP, JP-A-2-24648, JP-A-2-18
4844, JP-A-3-109545, JP-A-3-137637, JP-A-3-141346, JP-A-3-141347, JP-A-4-96
No. 055, U.S. Pat. No. 4,645,731, JP-A-4-68344, and Japanese Patent No. 2,557,
No. 641, page 2, right column, line 20 to page 3, right column, line 30;
Paragraph number [002] of the specification of Japanese Patent Application No. 10-221039.
0] to [0037] and vinylidene chloride copolymers containing 70% by mass or more of vinylidene chloride monomer repeating units described in paragraphs [0063] to [0080] of Japanese Patent Application No. 11-106881. It is preferable to provide an undercoat layer containing the undercoat layer.

When the amount of the vinylidene chloride monomer is less than 70% by mass, sufficient moisture-proof properties cannot be obtained, and the dimensional change over time after thermal development becomes large. Further, the vinylidene chloride copolymer preferably contains a repeating unit of a carboxyl group-containing vinyl monomer as another constituent repeating unit of the vinylidene chloride monomer. It is only vinyl chloride monomer that contains such a repeating unit,
The polymer (polymer) is crystallized, making it difficult to form a uniform film when applying a moisture-proof layer. In addition, a carboxyl group-containing vinyl monomer is indispensable for stabilizing the polymer (polymer). Because there is. The vinylidene chloride copolymer used in the present invention has a weight average molecular weight of 45.0.
00 or less, and more preferably 10,000 to 45,000. When the molecular weight is increased, the adhesiveness between the vinylidene chloride copolymer layer and a support layer such as polyester tends to deteriorate.

The content of the vinylidene chloride copolymer used in the present invention is 0.3 μm or more as a total film thickness per one side of the undercoat layer containing the vinylidene chloride copolymer.
Preferably it is in the range of 0.3 μm to 4 μm. The vinylidene chloride copolymer layer as the undercoat layer is preferably provided as the first undercoat layer directly provided on the support. Usually, one layer is provided on each side, but in some cases, two layers are provided. The above may be provided. When a multi-layer structure of two or more layers is used, the total amount of the vinylidene chloride copolymer may fall within the range of the present invention. Such a layer may contain a crosslinking agent, a matting agent, and the like in addition to the vinylidene chloride copolymer. The support may be coated, if necessary, with an undercoat layer using SBR, polyester, gelatin or the like as a binder, in addition to the vinylidene chloride copolymer layer. These undercoat layers may have a multilayer structure or may be provided on one side or both sides of the support. Thickness of undercoat layer (1
(Per layer) is generally between 0.01 and 5 μm, more preferably between 0.05 and 1 μm.

Various supports can be used for the high-speed photothermographic material of the present invention. Typical supports include polyesters such as polyethylene terephthalate and polyethylene naphthalate, cellulose nitrate, cellulose esters, polyvinyl acetal, syndiotactic polystyrene, polycarbonate, and paper supports coated on both sides with polyethylene. Among them, biaxially stretched polyester, particularly polyethylene terephthalate (PET), is preferred in terms of strength, dimensional stability, chemical resistance and the like. The thickness of the support is preferably 90 to 180 μm as a base thickness excluding the undercoat layer. Examples of the support used in the high-speed photothermographic material of the present invention include JP-A-10-48772, JP-A-10-10676, JP-A-10-10677, and JP-A-11-65.
No. 025, Japanese Patent Application Laid-Open No. 11-138648, a temperature of 130 to 185 ° C. in order to alleviate the internal strain remaining in the film at the time of biaxial stretching and to eliminate the heat shrinkage strain generated during the heat development processing. Polyester, particularly polyethylene terephthalate, which has been subjected to a heat treatment in the range is preferably used. 12 of the support after such heat treatment
The dimensional change rate by heating at 0 ° C. for 30 seconds is −0.03% to + 0.01% in the vertical direction (MD), and 0 in the horizontal direction (TD).
Preferably it is 0.04%.

The high-speed photothermographic material of the present invention is disclosed in Japanese Patent Application Laid-Open No. H11-84573 for the purpose of reducing adhesion of dust, preventing generation of static marks, and preventing transport failure in an automatic transport step.
The antistatic effect can be achieved by using a conductive metal oxide and / or a fluorinated surfactant described in paragraphs [0040] to [0051] of JP-A No. 6-1980. Examples of the conductive metal oxide include U.S. Pat. No. 5,575,957 and Japanese Patent Application No. 10-041302, paragraph [0012].
[0020] Needle-like conductive tin oxide doped with antimony described in [0020] and fibrous tin oxide doped with antimony described in JP-A-4-29134 are preferably used.

The surface resistivity (surface resistivity) of the metal oxide-containing layer is 10 ¹² Ω or less, preferably 10 ¹¹ Ω or less in an atmosphere at 25 ° C. and a relative humidity of 20%. Thereby, good antistatic properties can be obtained. The lower limit of the surface resistivity at this time is not particularly limited, but is usually about 10 ⁷ Ω. The Beck smoothness of at least one of the surface having the image forming layer of the high-speed photothermographic material of the invention and the outermost layer surface opposite to the surface, and preferably both, is 2,000 seconds or less, more preferably 10 seconds to 2,000 seconds. It is. The Beck smoothness in the present invention can be easily determined by Japanese Industrial Standards (JIS) P8119 “Smoothness test method of paper and paperboard using Beck tester” and TAPPI standard method T479. The Beck smoothness of the outermost layer on the surface having the image forming layer of the high-speed photothermographic material and the outermost layer on the opposite side thereof are described in paragraphs [0052] to JP-A-11-84573.
As described in [0059], it can be controlled by appropriately changing the particle size and the amount of the matting agent contained in the layers on both surfaces.

In the present invention, a water-soluble polymer is preferably used as a thickener for imparting coating properties, and may be a natural product or a synthetic polymer, and the type thereof is not particularly limited. Specifically, as natural products, starches (corn starch,
Starch, etc.), seaweed (agar, sodium alginate, etc.), vegetable glue (gum arabic, etc.), animal protein (glue, casein, gelatin, egg white, etc.), fermented glue (pullulane, dextrin, etc.), etc. Starch materials (soluble starch, carboxyl starch, dextran, etc.) and celluloses (viscose, methyl cellulose, ethyl cellulose,
Carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, etc.), and synthetic polymers (polyvinyl alcohol, polyacrylamide,
Polyvinyl pyrrolidone, polyethylene glycol, polypropylene glycol, polyvinyl ether, polyethylene imine, polystyrene sulfonic acid or its copolymer, polyvinyl sulfanic acid or its copolymer, polyacrylic acid or its copolymer, acrylic acid or its copolymer Maleic acid copolymer, maleic acid monoester copolymer, acryloylmethylpropanesulfonic acid or a copolymer thereof).

Among these, the water-soluble polymers preferably used are sodium alginate, gelatin, dextran, dextrin, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, polyethylene glycol, polypropylene glycol, Polystyrene sulfonic acid or its copolymer, polyacrylic acid or its copolymer, maleic acid monoester copolymer, acryloylmethylpropane sulfonic acid or its copolymer, and the like are particularly preferably used as a thickener.
Particularly preferred thickeners among these are gelatin, dextran, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone,
Examples include polystyrene sulfonic acid or its copolymer, polyacrylic acid or its copolymer, and maleic acid monoester copolymer. These compounds are described in detail in "Applications and Markets of New Water-Soluble Polymers" (published by CMC Corporation, edited by Shinji Nagatomo, issued on November 4, 1988).

The amount of the water-soluble polymer used as a thickener is not particularly limited as long as the viscosity increases when added to a coating solution. Generally, the concentration in the liquid is 0.01 to 30% by mass, more preferably 0.05 to 20% by mass, and particularly preferably 0.1 to 10% by mass. The viscosity obtained by these methods is 1 to 200 mPa as an increase from the initial viscosity.
S is preferable, and more preferably 5 to 100 mPa · s.
It is. The viscosity is a value measured at 25 ° C. with a B-type rotational viscometer. When adding to a coating solution or the like, it is generally desirable to add the thickener in a solution as dilute as possible. In addition, it is preferable to perform sufficient stirring during the addition.

The surfactant used in the present invention will be described below. Surfactants used in the present invention are classified into dispersants, coating agents, wetting agents, antistatic agents, photographic control agents, and the like depending on the purpose of use, and the surfactants described below are appropriately selected and used. These objectives can be achieved by doing so. The surfactant used in the present invention may be either nonionic or ionic (anion, cation, betaine). Further, a fluorine-based surfactant is also preferably used. Preferred nonionic surfactants include polyoxyethylene, polyoxypropylene, polyoxybutylene, a surfactant having a nonionic hydrophilic group of polyglycidyl or sorbitan, and specifically, polyoxyethylene. Alkyl ether, polyoxyethylene alkyl phenyl ether,
Polyoxyethylene-polyoxypropylene glycol, polyhydric alcohol fatty acid partial ester, polyoxyethylene polyhydric alcohol fatty acid partial ester, polyoxyethylene fatty acid ester, polyglycerin fatty acid ester, fatty acid diethanolamide, triethanolamine fatty acid partial ester Can be.

Examples of the anionic surfactant include carboxylate, sulfate, sulfonate and phosphate ester salt. Representative examples thereof include fatty acid salt, alkylbenzene sulfonate and alkylnaphthalenesulfonic acid. Salt, alkyl sulfonate, α-olefin sulfonate, dialkyl sulfosuccinate, α-sulfonated fatty acid salt, N-methyl-N-oleyltaurine, petroleum sulfonate, alkyl sulfate, sulfated oil, polyoxy Examples include ethylene alkyl ether sulfate, polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene styrenated phenyl ether sulfate, alkyl phosphate, polyoxyethylene alkyl ether phosphate, and naphthalene sulfonate formaldehyde condensate. Can be.

As the cationic surfactant, an amine salt,
Examples thereof include quaternary ammonium salts and pyridium salts, and include primary to tertiary fatty amine salts and quaternary ammonium salts (tetraalkylammonium salts, trialkylbenzylammonium salts, alkylpyridium salts, alkylimidazolium salts and the like). ). Examples of betaine-based surfactants include carboxybetaine and sulfobetaine, and N-trialkyl-N-
Carboxymethyl ammonium betaine, N-trialkyl-N-sulfoalkylene ammonium betaine and the like can be mentioned. These surfactants are described in "Applications of Surfactants" (written by Koshobo and Takao Karimei, published on September 1, 1980). In the present invention, the preferred surfactant is not particularly limited in its use amount,
Any amount may be used as long as the desired surface activity characteristics can be obtained. In addition, the application amount of the fluorine-containing surfactant was 0.1 ml / m ² .
Preferred is between 01 mg and 250 mg.

Specific examples of the surfactant are described below, but are not limited thereto (here, -C ₆ H _4- represents a phenylene group). _{WA-1: C 16 H 33} (OCH 2 CH 2) 10 OH WA-2: C 9 H 19 -C 6 H 4 - (OCH 2 CH 2) 12 OH WA-3: sodium dodecylbenzene sulfonate WA-4 : Sodium tri (isopropyl) naphthalenesulfonate WA-5: sodium tri (isobutyl) naphthalenesulfonate WA-6: sodium dodecyl sulfate WA-7: α-sulfosuccinic acid di (2-ethylhexyl) ester sodium salt WA-8: C _{8 H 17 -C 6 H 4 -} (CH 2 CH 2 O) 3 (CH 2) 2 SO 3 K WA-10: cetyltrimethylammonium chloride _{WA-11: C 11 H 23} CONHCH 2 CH 2 N + (CH 3 ^{_{) 2 -CH 2 COO - WA-}} 12: C 8 F 17 SO 2 N (C 3 H 7) (CH 2 CH 2 O) 16 H WA-13: C 8 F 17 SO 2 N (C 3 H 7) _{CH 2 COOK WA-14: C} 8 F 17 SO 3 K WA-15: C 8 F 17 SO 2 N (C 3 H 7) (CH 2 CH 2 O) 4 (CH 2) 4 SO 3 Na WA-16 : C ₈ F ₁₇ SO ₂ N (C ₃ H ₇ ) (CH ₂ ) ₃ OCH ₂ CH ₂ N ⁺ (CH ₃ ) _{3
-CH 3 -C 6 H 4 -SO 3} - WA-17: C 8 F 17 SO 2 N (C 3 H 7) CH 2 CH 2 CH 2 N + (CH 3) 2 -CH
₂ COO ^-

In a preferred embodiment of the present invention, an intermediate layer may be provided, if necessary, in addition to the image forming layer and the protective layer. For the purpose of improving productivity and the like, it is preferable that these plural layers are simultaneously coated in an aqueous system. The coating method includes extrusion coating, slide bead coating, curtain coating and the like.
The slide bead coating method shown in FIG. In the case of a silver halide photographic material using gelatin as a main binder, the material is rapidly cooled in a first drying zone provided downstream of a coating die, and as a result, gelatinization of gelatin occurs and the coating film is cooled and solidified. . The coating film that has been cooled and solidified and has stopped flowing is guided to the subsequent second drying zone, where the solvent in the coating solution is volatilized and formed into a film in the subsequent drying zone. As a drying method after the second drying zone, an air loop method in which a jet is blown from a U-shaped duct to a roller-supported support, or a support in which the support is wound around a cylindrical duct in a helical shape, and conveyed and dried. A fire method (air floating method) and the like can be mentioned.

When a layer is formed using a coating solution in which the main component of the binder is a polymer latex, the flow of the coating solution cannot be stopped by rapid cooling, so that the preliminary drying is insufficient only in the first drying zone. In some cases.
In this case, in a drying method such as used in a silver halide photographic light-sensitive material, flow unevenness and drying unevenness occur, and a serious defect is easily generated on the coated surface. The preferred drying method in the present invention is a horizontal drying method at least until the constant rate drying is completed, regardless of the first drying zone or the second drying zone as described in Japanese Patent Application No. 10-292849. This is a method of drying in a zone. The transfer of the support from the time immediately after the coating until the support is guided to the horizontal drying zone may or may not be horizontal, and the rising angle of the coating machine with respect to the horizontal direction may be between 0 and 70 °.
In addition, the horizontal drying zone in the present invention only needs to be conveyed within ± 15 ° up and down with respect to the horizontal direction of the coating machine, and does not mean horizontal conveyance.

The constant-rate drying in the present invention means a drying process in which the liquid film temperature is constant and all the heat flowing in is used for evaporating the solvent. At the end of drying, the rate of drying decreases at the end of drying due to various factors (such as the rate of diffusion of the material inside the material that controls the movement of water and the retreat of the evaporation surface), and the applied heat is also used to raise the liquid film temperature. Drying process. The critical water content at which the transition from the constant rate process to the rate reduction process is 200-3
00%. When the constant-rate drying is completed, the drying proceeds sufficiently until the flow stops, and thus a drying method such as a silver halide photographic light-sensitive material can be employed. It is preferred to dry in the horizontal drying zone to the drying point.

The drying conditions for forming the image forming layer and / or the protective layer are such that the liquid film surface temperature during constant-rate drying is 3 to less than the minimum film forming temperature of polymer latex (MTF; usually, glass transition temperature Tg of polymer). (5 ° C. higher) or more. Normally 25 ° C to 40 ° C due to limitations of manufacturing equipment
Often. Further, the dry-bulb temperature during the rate-decreasing drying is preferably a temperature lower than the Tg of the support (usually 80 ° C. or lower in the case of PET). The liquid film surface temperature in this specification refers to the solvent liquid film surface temperature of the coating liquid film applied to the support, and the dry bulb temperature refers to the temperature of the drying air in the drying zone. When the drying is performed under the condition that the liquid film surface temperature during the constant-rate drying is low, the drying tends to be insufficient. For this reason, particularly, the film forming property of the protective layer is significantly reduced, and cracks are easily generated on the film surface. In addition, the film strength is weakened, and serious problems such as susceptibility to damage during transport in an exposure machine or a heat developing machine are likely to occur.

On the other hand, when dried under the condition that the liquid film surface temperature becomes high, the protective layer mainly composed of the polymer latex quickly forms a film, while the lower layer such as the image forming layer has fluidity. Since the surface is not stopped, irregularities are likely to be generated on the surface. Further, when an excessive heat higher than Tg is applied to the support (base), the dimensional stability and the curl resistance of the photosensitive material tend to deteriorate. The same applies to the sequential coating in which the lower layer is applied and then dried and then the upper layer is applied. The pH difference between the coating solution for the image forming layer and the coating solution for the protective layer is preferably 2.5 or less, and the smaller the pH difference, the better. When the pH difference of the coating liquid is large, micro-aggregation is likely to occur at the coating liquid interface, and a serious surface failure such as a coating streak tends to occur during continuous continuous coating.

The coating solution viscosity of the image forming layer is 15 to 25 ° C.
100 mPa · s is preferred, and more preferably 30 to
70 mPa · s. On the other hand, the coating liquid viscosity of the protective layer is 2
The temperature is preferably 5 to 75 mPa · s at 5 ° C., and more preferably 20 to 50 mPa · s. These viscosities are measured by a B-type viscometer. Winding after drying is 20 ~
It is preferable to perform the process under the condition of 30 ° C. and a relative humidity of 45 ± 20%, and the winding form may be on the image forming layer side outside or on the inside according to the subsequent processing form. Further, when the processing form is a roll product, it is also preferable to use a roll form wound on the side opposite to the winding form at the time of processing in order to remove the curl generated in the winding form. It is preferable that the relative humidity of the photosensitive material is controlled in the range of 20 to 55% (measured at 25 ° C.).

In a conventional photographic emulsion coating solution which is a viscous liquid containing silver halide and containing gelatin as a substrate, bubbles are dissolved and disappear in the solution simply by sending the solution under pressure. Even when returned, there is almost no bubble deposition. However, in the case of an image forming layer coating solution containing an organic silver salt dispersion and a polymer latex which are preferably used in the present invention, defoaming tends to be insufficient only by pressurized liquid feeding, so that a gas-liquid interface does not occur. It is preferable to remove the bubbles by applying ultrasonic vibration while feeding the liquid. In the present invention, the defoaming of the coating liquid is performed by degassing under reduced pressure before applying the coating liquid, further maintaining the pressurized state at 1.5 kg / cm ² or more, and continuously generating no gas-liquid interface. It is preferable to apply ultrasonic vibration while feeding the liquid to the container. Specifically, Japanese Patent Publication No. 55-6405 (page 4, line 20 to page 7, line 1)
(1 line) is preferred. As an apparatus for performing such defoaming, an embodiment shown in Japanese Patent Application No. 10-290003 and an apparatus shown in FIG. 3 can be preferably used.

The pressing condition is preferably 1.5 kg / cm ² or more, more preferably 1.8 kg / cm ² or more. There is no particular upper limit, but usually 5 kg / cm ²
It is about. The applied ultrasonic sound pressure is 0.2V or more,
The sound pressure is preferably 0.5 V to 3.0 V, and in general, it is preferable that the sound pressure be high. However, if the sound pressure is too high, the temperature becomes partially high due to caption, which causes fogging. The frequency is not particularly limited, but is usually 10 kHz or more,
Preferably, it is 20 kHz to 200 kHz. In addition, decompression degassing refers to deaeration by increasing the air bubble diameter in the coating solution, increasing the buoyancy, and degassing the inside of the tank (usually a liquid preparation tank or a storage tank). Decompression conditions are -200 mmHg or lower pressure conditions,
The pressure condition is preferably -250 mmHg or lower, and the lowest pressure condition is not particularly limited, but is usually about -800 mmHg. Decompression time is 30 minutes or more,
It is preferably 45 minutes or more, and the upper limit is not particularly limited.

In the present invention, the image forming layer, the protective layer of the image forming layer, the undercoat layer and the back layer are described in JP-A-11-84.
No. 573, paragraph numbers [0204] to [0208],
Paragraph number [024] of Japanese Patent Application No. 11-106881
0] to [0241], a dye can be contained for the purpose of preventing halation and the like. Various dyes and pigments can be used in the image forming layer from the viewpoints of color tone improvement and irradiation prevention. Although any dyes and pigments can be used for the image forming layer, for example, compounds described in paragraph [0297] of JP-A-11-119374 can be used. 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 to be used is determined depending on the desired absorption amount, but is generally 1 × 10 ⁻⁶ g / m ^2.
It is preferable to use in the range of 1 g.

When an antihalation dye is used in the present invention, the dye has a desired absorption in a desired range, has a sufficiently low absorption in the visible region after treatment, and has a desirable absorbance spectrum shape of the back layer. Any compound can be used, if possible. For example, the compound described in paragraph [0300] of JP-A-11-119374 can be used. Further, as described in Belgian Patent No. 733,706, a method in which the concentration of a dye is reduced by discoloration by heating, or by discoloration by light irradiation as described in JP-A-54-17833. A method of reducing the concentration and the like can also be used.

When the high-speed photothermographic material of the present invention is used as a mask when preparing a printing plate using a PS plate after heat development, the high-speed photothermographic material after the heat development is applied to a PS plate in a plate making machine. Information for setting exposure conditions and information for setting plate making conditions such as mask original and PS plate transfer conditions are carried as image information. Therefore, the concentration (use amount) of the irradiation dye, the halation dye, and the filter dye is limited in order to read them. Since such information is read by an LED or a laser, Dmin (minimum concentration) in the wavelength range of the sensor needs to be low, and the absorbance needs to be 0.3 or less. For example, a plate making machine S-FNRIII manufactured by Fuji Photo Film Co., Ltd. has a 670 nm as a detector and a bar code reader for detecting a register mark.
The light source of the wavelength is used. Also, as a barcode reader for the plate making machine APML series manufactured by Shimizu Seisakusho,
A 0 nm light source is used. That is, when Dmin (minimum density) around 670 nm is high, information on the film cannot be detected accurately, and a work error such as a conveyance failure or an exposure failure occurs in a plate making machine. Therefore, in order to read information with a 670 nm light source, Dmin around 670 nm needs to be low, and the absorbance at 660 to 680 nm after thermal development needs to be 0.3 or less. More preferably 0.25
It is as follows. Although the lower limit is not particularly limited, it is usually 0.1.
It is about 10.

In the present invention, the exposure apparatus used for imagewise exposure may be any apparatus capable of exposing for an exposure time of 10 ⁻¹⁵ seconds to 10 ⁻⁷ seconds, but generally a laser diode (LD) ), 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, in the case of LD, a dye laser, a gas laser, a solid laser, a semiconductor laser, or the like can be used. Exposure time is 10
It is preferable to set to ^-11 seconds to 10 ^-7 seconds. Irradiation energy is preferably ^{5μJ / cm 2 ~1mJ / cm 2} , it is preferred that particularly ^{10μJ / cm 2 ~200μJ / cm 2} .

The exposure in the present invention is performed by overlapping the light beams of the light source. The overlap means that the sub-scanning pitch width is smaller than the beam diameter. For example, the overlap is determined by changing the beam diameter to a half value width (FW) of the beam intensity.
HM), it can be quantitatively expressed by FWHM / sub-scanning pitch width (overlap coefficient).
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. 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. That is, it is preferable to perform exposure with a multi-beam equipped with two or more laser heads.

The high-speed photothermographic material of the present invention has a low haze at the time of exposure and tends to cause interference fringes. As a technique for preventing the occurrence of this interference fringe, see Japanese Patent Application Laid-Open No. 5-113548.
And Japanese Patent Application Publication No. WO 95/31, for example, a technique disclosed in Japanese Patent Application Publication No.
A method using a multi-mode laser disclosed in, for example, Japanese Patent No. 754 is known, and it is preferable to use these techniques. The heat development step of the image forming method used in the present invention may be any method, but usually, the high-speed photothermographic material exposed imagewise is heated and developed. As a preferred embodiment of the thermal developing machine used,
JP-B-5-5649 is a type in which a high-speed photothermographic material is brought into contact with a heat source such as a heat roller or a heat drum.
9, Japanese Patent Application Laid-Open No. 9-292695, Japanese Patent Application Laid-Open
297385 and International Publication WO 95/3093
Japanese Patent Application Laid-Open No. 7-13294 as a non-contact type heat developing machine described in Japanese Patent Application Publication No.
Nos. 89, 97/28488 and 97/28488
There is a heat developing machine described in Japanese Patent No. 28487. A particularly preferred embodiment is a non-contact type thermal developing machine. The preferred development temperature is 80 to 250C, more preferably 100 to 140C. The development time is 1 to 18
0 seconds is preferable, and 5 to 90 seconds is more preferable. As a method for preventing processing unevenness due to a dimensional change of the high-speed photothermographic material during thermal development, the image is heated at a temperature of 80 ° C. or more and less than 115 ° C. for 5 seconds or more.
It is effective to adopt a method of forming an image by thermal development at 10 ° C. to 140 ° C. (a so-called multi-stage heating method).

When the high-speed photothermographic material of the present invention is subjected to thermal development processing, it is exposed to a high temperature of 110 ° C. or more, so that some of the components contained in the material or some of the components decomposed by thermal development are included. 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. As a method for eliminating 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 methods can be effectively used in combination. International Patent Publication Nos. WO95 / 30933, 97/21150, and JP-T10-500496 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 in contact with a film. In addition, International Publication WO96
Japanese Patent Application Laid-Open No. 12213/1990 and Japanese Patent Application Laid-Open No. 10-507403 describe the use of a filter combining a thermally conductive condensation collector and a gas-absorbing fine particle filter. In the present invention, these can be preferably used. U.S. Pat. No. 4,518,845 and Japanese Patent Publication No. 3-54331 disclose a device for removing vapor from a film, a pressurizing device for pressing the film against a heat transfer member, and heating of the heat transfer member. A configuration having an apparatus for performing the above is described. In addition, International Publication WO98 / 27458 describes that a component which increases fog which evaporates from a film is removed from the film surface. These can also be preferably used in the present invention.

FIG. 1 shows an example of the configuration of a heat developing machine used for the heat developing process of the high-speed photothermographic material of the present invention. FIG. 1 is a side view of the heat developing machine. The heat developing machine shown in FIG. 1 carries in a pair of carry-in rollers 11 for carrying the high-speed photothermographic material 10 into a heating section while correcting and preheating the flat surface of the high-speed photothermographic material 10 (the upper roller is a silicon rubber roller and the lower roller is an aluminum heat roller). And an unloading roller pair 12 which unloads the high-speed photothermographic material 10 after the thermal development from the heating unit while correcting it into a planar shape. The high-speed 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 high-speed 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 to which an aromatic polyamide or Teflon) is attached is provided. The high-speed photothermographic material 10 is conveyed while the back surface is slid over the smooth surface 14 by driving a plurality of rollers 13 that come into contact with the surface having the image forming layer. A heater 15 is provided above the roller 13 and below the smooth surface 14 so as to heat the high-speed photothermographic material 10 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 allows the high-speed photothermographic material 10 to be conveyed. Preferably it is 0 to 1 mm.

Material of Roller 13 Surface and Smooth Surface 1
The member No. 4 is durable at high temperatures and is a high-speed photothermographic material 1
Any material may be used as long as it does not hinder the conveyance of 0, but the material of the roller surface is preferably silicon rubber, and the member of the smooth surface is preferably a nonwoven fabric made of aromatic polyamide or Teflon (PTFE).
It is preferable to use a plurality of heaters as the heating means and to set the heating temperature freely. The heating unit includes a pre-heating unit A having the carry-in roller pair 11 and a heat development heating unit B including the heating heater 15. The pre-heating unit A upstream of the heat development processing unit B includes: It is desirable that the temperature and time are set lower than the heat development temperature (for example, about 10 to 30 ° C.) and sufficient to evaporate the amount of water in the high-speed photothermographic material 10. It is preferable to set the temperature at a temperature higher than the glass transition temperature (Tg) of the support so that development unevenness does not occur. The temperature distribution of the preheating section and the heat development section is ±
It is preferably at most 1 ° C, more preferably at most ± 0.5 ° C. Further, a guide plate 16 is provided downstream of the thermal development processing unit B, and a slow cooling unit 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 a low thermal conductivity, and is preferably cooled gradually so as not to deform the high-speed photothermographic material 10. Seconds are preferred.

Although the above has been described with reference to the illustrated example, the invention is not limited to this. 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,
What is necessary is just to install two or more heat sources with different heating temperatures, and to heat continuously at different temperatures.

[0094]

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

<Example 1><< Preparation of silver halide emulsion A >> Alkaline-treated gelatin (calcium content: 2700 ppm) was added to 700 ml of water.
After dissolving 11 g, 30 mg of potassium bromide and 1.3 g of sodium 4-methylbenzenesulfonate and adjusting the pH to 6.5 at a temperature of 45 ° C, 18.6 g of silver nitrate
g of aqueous solution, potassium bromide at 1 mol / l (NH ₄ ) ₂ RhCl ₅ (H ₂ O) at 5 × 10 ^-6 mol / l and K ₃ IrCl ₆ at 2 × 10 ^-5 mol / l. The aqueous solution contained was added over 6 minutes and 45 seconds by the control double jet method while maintaining the pAg at 7.7. Then, 476 ml of an aqueous solution containing 55.5 g of silver nitrate, 1 mol / l of potassium bromide and 2 × 1 of K ₃ IrCl ₆ were added.
PAg halogen salt aqueous solution containing 0 ^-5 mol / l
Controlled by the double jet method while maintaining at 7.7
Added over 9 minutes. Thereafter, the pH is lowered to cause coagulation sedimentation and desalting treatment, and low-molecular-weight gelatin having an average molecular weight of 15,000 (calculated as 20 ppm or less) 5
The pH was adjusted to 5.9 and the pAg to 8.0 by adding 1.1 g.
The obtained particles were cubic particles having an average particle size of 0.10 μm, a projection 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.
After the addition of μmol, the mixture was aged for 100 minutes, and 5 × 10 ⁻⁴ mol of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene and 0.17 g of compound A were added.
The temperature was lowered to 0 ° C. Thereafter, the temperature was maintained at 40 ° C., and 4.7 × 10 ⁻² mol of potassium bromide (added as an aqueous solution) and 12.8 × 10 ⁻⁴ mol of the following sensitizing dye A per mol of silver halide ( 6.4 ×)
10 ^-3 mol of compound B (added as a methanol solution) was added with stirring, and after 20 minutes, the mixture was rapidly cooled to 30 ° C. to complete the preparation of silver halide emulsion A.

[0096]

Embedded image

<< Preparation of Silver Halide Emulsion B >> The average grain size was 0.08 μm as in the case of silver halide emulsion A, except that the grain formation temperature of silver halide emulsion A was changed to 40 ° C.
Was prepared.

<< Preparation of Silver Halide Emulsion C >> The average grain size was 0.06 μm as in the case of the silver halide emulsion A, except that the grain formation temperature of the silver halide emulsion A was changed to 30 ° C.
Was prepared.

<< Preparation of Silver Behenate Dispersion A >><Reaction and Crystallization> Behenic acid (product name: Ede, manufactured by Henkel Co.)
norC22-85R) 87.6 g, distilled water 423 m
1, 5N-NaOH aqueous solution (49.2 ml) and tert-butyl alcohol (120 ml) were mixed and reacted by stirring at 75 ° C. for 1 hour to obtain a sodium behenate solution. Separately, 206.2 ml of an aqueous solution of 40.4 g of silver nitrate was prepared and kept at 10 ° C. 635ml of distilled water and 30m
1 tert-butyl alcohol in a reaction vessel 3
While maintaining the temperature at 0 ° C. and stirring, the total amount of the sodium behenate solution and the total amount of the silver nitrate aqueous solution were each adjusted to 6 at a constant flow rate.
It was added over 2 minutes 10 seconds and 60 minutes. At this time, only the silver nitrate aqueous solution was added for 7 minutes and 20 seconds after the addition of the silver nitrate aqueous solution was started, and then the addition of the sodium behenate solution was started, and only 9 minutes and 30 seconds after the completion of the silver nitrate aqueous solution, only the sodium behenate solution was added. It was made to be added. At this time, the temperature in the reaction vessel was set to 30 ° C., and the temperature was controlled so as not to rise. Further, the piping of the addition system of the sodium behenate solution was kept warm by steam tracing, and the amount of steam was controlled so that the liquid temperature at the outlet at the tip of the addition nozzle became 75 ° C. The piping of the silver nitrate aqueous solution addition system was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution.

<Desalting and Wet Cake Formation> 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. Then, 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 microscopic photographing, the average projected area diameter was 0.52 μm and the average grain thickness was 0.3 mm.
It was a flaky crystal having a diameter of 14 μm and a coefficient of variation of the average equivalent spherical diameter of 15%.

<Dispersion> Next, a dispersion of silver behenate was prepared by the following method. For a wet cake equivalent to 100 g of dry solids, polyvinyl alcohol (trade name: PVA)
-217, average degree of polymerization: about 1700) and water were added to make the total amount 1925 g, and the mixture was predispersed with a homomixer. Next, the pre-dispersed stock solution is dispersed in a dispersing machine (trade name: Microfluidizer M-110SE-E).
H, manufactured by Microfluidics International Corporation, using a G10Z interaction chamber) at a pressure of 1720 kg / cm ² and treated three times to obtain a silver behenate dispersion A. 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.

<< Preparation of Silver Behenate Dispersion B >> The reaction, crystallization and desalting, and formation of a wet cake were performed using a silver behenate dispersion A.
Prepared in the same manner as Thereafter, polyvinyl alcohol (trade name: PVA-217, average degree of polymerization: about 1700) 7.4 was applied to the wet cake having a dry solid content of 100 g.
g and water to make a total amount of 1925 g,
After adjusting to 4,000 kg / cm ² , an ultra-high pressure disperser (BEE INTERNALAL, DeB
EE2000) twice and cooled to obtain a silver behenate dispersion B.

Table 1 shows the average particle size of the obtained silver behenate dispersion (evaluated by electron micrograph).

[0104]

[Table 1]

<< Preparation of Dispersion A of Solid Fine Particles of Reducing Agent >> Reducing Agent A [1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane] 1
0 kg and denatured polyvinyl alcohol (Kuraray Co., Ltd.
Poval MP203) to 10 kg of a 20% by mass aqueous solution,
Surfynol 104E (Nissin Chemical Co., Ltd.) 400 g
And 640 g of methanol and 16 kg of water were added and mixed well to form a slurry. This slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by IMEX Co., Ltd.) filled with zirconia beads having an average particle diameter of 500 μm for 3 hours and 40 minutes, and then 4 g of benzoisothiazolinone sodium salt And water were added to adjust the concentration of the reducing agent to 25% by mass to obtain a solid fine particle dispersion of the reducing agent. The resulting dispersion had a pore size of 3.0 μm.
And filtered to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion B of Solid Fine Particles of Reducing Agent >> In the preparation of dispersion A of solid fine particles of reducing agent, the average particle diameter of the zirconia beads used was 400 μm, and the dispersion time was 4 hours and 30 minutes. Except for the above, a solid fine particle dispersion B of a reducing agent was obtained in the same manner.

<< Preparation of Dispersion C of Solid Fine Particles of Reducing Agent >> In the preparation of dispersion A of solid fine particles of reducing agent, except that the average particle size of the zirconia beads used was 300 μm and the dispersion time was 6 hours. By the same operation, a solid fine particle dispersion C of a reducing agent was obtained.

<< Preparation of Dispersion D of Solid Fine Particles of Reducing Agent >> In the same manner as dispersion A of solid fine particles of reducing agent, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,
A slurry of 5,5-trimethylhexane was obtained. This slurry is fed by a diaphragm pump and has an average particle size of 150.
After dispersing for 5 hours and 30 minutes using a sand mill disperser filled with μm polyethylene beads, 4 g of benzoisothiazolinone sodium salt and water were added to adjust the concentration of the reducing agent to 25% by mass. A solid fine particle dispersion D was obtained. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion E of Solid Fine Particles of Reducing Agent >> In preparation of dispersion D of solid fine particles of reducing agent, except that the average particle size of the polyethylene beads used was set to 50 μm and the dispersion time was set to 7 hours. By the same operation, a solid fine particle dispersion E of a reducing agent was obtained.

Table 2 shows the average particle size (evaluated by electron microscopic photographing) of the obtained dispersion of solid fine particles of the reducing agent.

[0111]

[Table 2]

<< Preparation of Solid Fine Particle Dispersion A of Organic Polyhalogen Compound A >> 10 kg of organic polyhalogen compound A [tribromomethyl (4- (2,4,6-trimethylphenylsulfonyl) phenyl) sulfone] and modified polyvinyl Alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.)
10 kg of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate and 639% of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate
g and Surfynol 104E (manufactured by Nissin Chemical Co., Ltd.) 4
00 g, 640 g of methanol and 16 kg of water were added and mixed well to form a slurry. This slurry was sent by a diaphragm pump, dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average particle diameter of 500 μm for 5 hours, and then water was added to the slurry to form an organic polyhalogen compound A. The concentration was adjusted to 25% by mass to obtain a solid fine particle dispersion A of the organic polyhalogen compound A. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Solid Fine Particle Dispersion E of Organic Polyhalogen Compound A >> In the preparation of solid fine particle dispersion D of organic polyhalogen compound A, the average particle size of the polyethylene beads used was set to 50 μm, and the dispersion time was reduced. 7 hours 4
The same operation was performed except that the time was set to 0 minutes, whereby a solid fine particle dispersion E of the organic polyhalogen compound A was obtained.

The organic polyhalogen compound A obtained in Table 3
Of the solid fine particle dispersion (evaluated by electron microscopy).

[0115]

[Table 3]

<< Preparation of Solid Fine Particle Dispersion A of Organic Polyhalogen Compound B >> 5 kg of organic polyhalogen compound B [tribromomethylnaphthyl sulfone] and 20 parts of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.)
2.5 kg of a 20% by mass aqueous solution and 213 g of a 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate
And 10 kg of water were added and mixed well to form a slurry. This slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by IMEX Co., Ltd.) filled with zirconia beads having an average particle diameter of 500 μm for 5 hours, and then 2.5 g of benzoisothiazolinone sodium salt And water were added to adjust the concentration of the organic polyhalogen compound B to 20% by mass to obtain a solid fine particle dispersion of the organic polyhalogen compound B. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Solid Fine Particle Dispersion B of Organic Polyhalogen Compound B >> In the preparation of solid fine particle dispersion A of organic polyhalogen compound B, the zirconia beads used had an average particle diameter of 400 μm and a dispersion time of zirconia beads. Except for 6 hours, the same operation was carried out to obtain the organic polyhalogen compound B
Of solid fine particle dispersion B was obtained.

<< Preparation of Solid Fine Particle Dispersion C of Organic Polyhalogen Compound B >> In preparation of solid fine particle dispersion A of organic polyhalogen compound B, the zirconia beads used had an average particle diameter of 300 μm and a dispersion time of 300 μm. Except for 7 hours, the same operation was performed to obtain the organic polyhalogen compound B
Of solid fine particle dispersion C was obtained.

<< Preparation of Solid Fine Particle Dispersion D of Organic Polyhalogen Compound B >> A slurry of organic polyhalogen compound A was obtained in the same manner as for solid fine particle dispersion A of organic polyhalogen compound B. This slurry was sent by a diaphragm pump and dispersed by a sand mill disperser filled with polyethylene beads having an average particle size of 150 μm for 6 hours and 30 minutes.
Water was added to adjust the concentration of the organic polyhalogen compound A to 25% by mass to obtain a solid fine particle dispersion D of the organic polyhalogen compound B. The resulting dispersion has a pore size of 3.
After filtration through a 0 μm polypropylene filter,
Foreign matter such as dust was removed and stored.

<< Preparation of Solid Fine Particle Dispersion E of Organic Polyhalogen Compound B >> In the preparation of solid fine particle dispersion D of organic polyhalogen compound B, the average particle size of the polyethylene beads used was set to 50 μm, and the dispersion time was reduced. 7 hours 4
The same operation was performed except that the time was set to 0 minutes, to obtain a solid fine particle dispersion E of the organic polyhalogen compound B.

The organic polyhalogen compound B obtained in Table 4
Of the solid fine particle dispersion (evaluated by electron microscopy).

[0122]

[Table 4]

<< Preparation of Aqueous Solution of Organic Polyhalogen Compound C >> Preparation Formulation (Rate per 100 ml of Completed Quantity) Water 75.0 ml 20% aqueous solution of sodium tripropylnaphthalenesulfonate 8.6 ml sodium dihydrogen orthophosphate dihydrate 5% aqueous solution of the product 6.8 ml 1 mol / l aqueous solution of potassium hydroxide 9.5 ml Organic polyhalogen compound C (3-tribromomethanesulfonylbenzoylaminoacetic acid) 4.0 g An organic polyhalogen compound C aqueous solution was prepared by the following procedure. did. While stirring at room temperature, water, a 20% aqueous solution of sodium tripropylnaphthalenesulfonate, a 5% aqueous solution of sodium dihydrogen orthophosphate dihydrate, and a 1 mol / l aqueous solution of potassium hydroxide are sequentially added, and all are added. Thereafter, the mixture was stirred and mixed for 5 minutes. Further, the powder of the organic polyhalogen compound C was added with stirring, and the mixture was uniformly dissolved until the solution became transparent. The resulting aqueous solution was filtered through a 200-mesh polyester screen to remove foreign substances such as dust, and stored.

<< Preparation of Emulsified Dispersion A of Compound Z >> 10 parts of R-054 manufactured by Sanko Co., Ltd.
After mixing kg and 11.66 kg of MIBK, the mixture was replaced with nitrogen and dissolved at 80 ° C. for 1 hour. 25.52k of water
g and MP-203-20 of MP polymer manufactured by Kuraray Co., Ltd.
12.76 kg of a 20% by weight aqueous solution and 0.44% of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate
kg at 60 ° C. at 20 to 40 ° C. and 3600 rpm.
It was emulsified and dispersed for minutes. In addition, Surfynol 1
04E (Nissin Chemical Co., Ltd.) 0.08 kg and water 47.9
After adding 4 kg and distilling under reduced pressure to remove MIBK,
It was prepared such that the concentration of compound Z was 10% by mass. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored. The average particle size of the obtained dispersion (evaluated by electron microscopy) was 0.18 μm.

<< Preparation of emulsified dispersion B of compound Z >> 10 parts of R-054 manufactured by Sanko Co., Ltd.
After mixing kg and 11.66 kg of MIBK, the mixture was replaced with nitrogen and dissolved at 80 ° C. for 1 hour. 25.52k of water
g and MP-203-20 of MP polymer manufactured by Kuraray Co., Ltd.
19.14 kg of a 20% by mass aqueous solution and 0.44% of a 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate.
kg at 12 to 40 ° C. and 4800 rpm.
Emulsified and dispersed for 0 minutes. Further, 0.08 kg of Surfynol 104E (manufactured by Nissin Chemical Co., Ltd.) and 47.
After adding 94 kg and distilling under reduced pressure to remove MIBK, the compound Z was prepared so as to have a concentration of 10% by mass. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored. The average particle size of the obtained dispersion (evaluated by electron microscopic photographing) was 0.047 μm.

<< Preparation of Dispersion of 6-Isopropylphthalazine Compound >> Preparation Formulation (Rate per 100 g of Complete Dispersion) Water 62.35 g Modified polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.) 2.0 g Polyvinyl alcohol ( 10% aqueous solution of Kuraray Co., Ltd., PVA-217) 25.5 g 20% aqueous solution of sodium tripropylnaphthalenesulfonate 3.0 g 6-isopropylphthalazine (70% aqueous solution) 7.15 g of 6-isopropylphthalazine compound The dispersion was prepared according to the following procedure. While stirring the water at room temperature, the modified polyvinyl alcohol was added so as not to form a lump, and mixed by stirring for 10 minutes. Thereafter, the mixture was heated and heated to an internal temperature of 50 ° C., and then stirred for 90 minutes at an internal temperature of 50 to 60 ° C. to be uniformly dissolved. The internal temperature was lowered to 40 ° C. or lower, and a 20% aqueous solution of polyvinyl alcohol and sodium tripropylnaphthalenesulfonate and 6-isopropylphthalazine (70% aqueous solution) were added, followed by stirring for 30 minutes to obtain a transparent dispersion. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of dispersion A of solid fine particles of nucleating agent >> Poval PVA- manufactured by Kuraray Co., Ltd.
217 and 1 kg of water were added and mixed well to form a slurry. This slurry was fed by a diaphragm pump, and a horizontal sand mill (UVM-2: IMEX Co., Ltd.) filled with zirconia beads having an average particle size of 500 μm.
), And 4 g of benzoisothiazolinone sodium salt and water were added to adjust the nucleating agent concentration to 10% by mass to obtain a solid fine particle dispersion of the nucleating agent. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Solid Fine Particle Dispersion B of Nucleating Agent >> In the preparation of solid fine particle dispersion A of nucleating agent Y, the average particle diameter of the zirconia beads used was 400 μm, and the dispersion time was 13 hours and 30 hours. Do the same except for the minutes
A solid fine particle dispersion B of the nucleating agent Y was obtained.

<< Preparation of Solid Fine Particle Dispersion C of Nucleating Agent >> In the preparation of solid fine particle dispersion A of nucleating agent Y, the zirconia beads used had an average particle size of 300 μm and a dispersion time of 15 hours. The same operation as above was carried out to obtain a solid fine particle dispersion C of the nucleating agent Y.

<< Preparation of Solid Fine Particle Dispersion D of Nucleating Agent >> A slurry of nucleating agent Y was obtained in the same manner as in the preparation of solid fine particle dispersion A of nucleating agent Y. This slurry was sent by a diaphragm pump, dispersed for 15 hours by a sand mill disperser filled with polyethylene beads having an average particle diameter of 150 μm, and then 4 g of benzoisothiazolinone sodium salt and water were added to adjust the nucleating agent concentration to 10 mass%. % To obtain a solid fine particle dispersion D of the nucleating agent Y. The resulting dispersion is
Filtration was performed with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Solid Fine Particle Dispersion E of Nucleating Agent >> In the preparation of the solid fine particle dispersion D of the nucleating agent Y, the average particle diameter of the polyethylene beads used was set to 50 μm, and the dispersion time was set to 18 hours. The same operation as above was carried out to obtain a solid fine particle dispersion E of the nucleating agent Y.

Table 5 shows the average particle size (evaluated by electron microscopy) of the obtained solid fine particle dispersion of the nucleating agent Y.

[0133]

[Table 5]

<< Preparation of solid accelerator dispersion A of development accelerator >> Development accelerator A (N- [4- (3,5-dichloro-4)
-Hydroxyphenylsulfamoyl) phenyl] acetamide), 10 kg of a 20% by mass aqueous solution of a modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.), and 20 kg of water were added and mixed well to form a slurry. This slurry is fed by a diaphragm pump, and a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 500 μm.
For 5 hours, water was added to adjust the concentration of the development accelerator to 20% by mass, and a solid fine particle dispersion of the development accelerator was obtained. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Solid Fine Particle Dispersion E of Development Accelerator >> A slurry of development accelerator A was obtained in the same manner as in the preparation of solid fine particle dispersion A of development accelerator. This slurry was sent by a diaphragm pump, and a sand mill disperser filled with polyethylene beads having an average particle diameter of 50 μm was used for 3 hours for 3 hours.
After dispersion for 0 minutes, water was added to adjust the concentration of the development accelerator to 20% by mass to obtain a solid fine particle dispersion E of the development accelerator. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

Table 6 shows the average particle size (evaluated by electron microscopy) of the obtained solid fine particle dispersion of the development accelerator.

[0137]

[Table 6]

<< Preparation of Coating Solution for Image Forming Layer >> The following binder, material, and silver halide emulsion A were mixed with 1 mol of silver of the silver behenate dispersion (the kind shown in Table 7) prepared above. In addition, water was added to obtain an image forming layer coating solution. After completion, degassing under reduced pressure was performed at a pressure of 0.54 atm for 45 minutes. The coating solution has a pH of 7.4 to 7.8 and a viscosity of 25 ° C.
Was 47 to 54 mPa · s. Binder; Luck Star 3307B 397 g as solid content (manufactured by Dainippon Ink and Chemicals, Ltd .; glass transition temperature of 17 ° C. with SBR latex) Reducing agent (type shown in Table 7) 149.5 g as solid content Organic polyhalogen compound B (Types described in Table 7) 36.3 g as solid content Organic polyhalogen compound C 2.34 g as solid content Sodium ethylthiosulfonate 0.47 g Benzotriazole 1.02 g Polyvinyl alcohol (PVA-235 manufactured by Kuraray Co., Ltd.) 10.8 g 6-isopropylphthalazine 15.0 g Compound Z (type described in Table 7) 9.7 g as a solid content Nucleator Y (type described in Table 7) 14.9 g as a solid content Dye A (average molecular weight) (Added as a mixture with 15,000 low molecular weight gelatin) The coating amount at which the optical density at 783 nm becomes 0.15 Estimated as 0.19 g) silver halide emulsion A Ag amount as 0.06 mol preservative as Compound A coating solution to 40 ppm (2.5 mg / m ² as coated amount) 2 mass% in methanol coating solution total solvent volume Ethanol 1% by mass as the total solvent amount in the coating solution (the glass transition temperature of the coating film was 17 ° C.)

[0139]

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<< Preparation of Coating Solution for Protective Layer >> Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2
-Hydroxyethyl methacrylate / acrylic acid = 5
8.9 / 8.6 / 25.4 / 5.1 / 2 (% by mass) of a polymer latex solution (copolymer having a glass transition temperature of 46
° C (calculated), solids concentration 21.5%, compound A at 10
0 ppm, water was added to 943 g of a coating solution containing 15% by mass of the compound D as a film-forming auxiliary with respect to the solid content of the latex, the glass transition temperature of the coating solution was 24 ° C., and the average particle diameter was 116 nm. Organic polyhalogen compound C
114.8 g of an aqueous solution, 17.0 g of an organic polyhalogen compound A (using dispersion A) as a solid, and 0.69 as a solid of sodium dihydrogen orthophosphate dihydrate as a solid.
g, 1.58 g of matting agent (polystyrene particles, average particle diameter 7 μm, coefficient of variation of average particle diameter 8%) and polyvinyl alcohol (Kuraray Co., Ltd., PVA-235) 2
9.3 g was added, and water was further added to prepare a coating solution (containing 0.9% by mass of a methanol solvent). After completion, deaeration under reduced pressure was performed at a pressure of 0.47 atm for 60 minutes. Coating solution pH
Was 5.6 and the viscosity at 25 ° C. was 42 mPa · s.

<< Preparation of Coating Solution for Lower Overcoat Layer >> Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 58.9 / 8.6 / 25.4 / 5.1 / 2
(Mass%) polymer latex solution (copolymer glass transition temperature 46 ° C. (calculated value), solid content concentration 21.5%,
Contains 100 ppm of compound A, compound D as a film-forming aid
625% based on the solid content of the latex, the glass transition temperature of the coating solution is 24 ° C, and the average particle diameter is 74 nm.
g was added with water, 0.23 g of compound C and 0.2 g of compound E were added.
13 g, 11.7 g of compound F, 2.7 g of compound H and polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA-
235) was added, and water was further added to prepare a coating liquid (containing 0.1% by mass of a methanol solvent). After completion, deaeration under reduced pressure was performed at a pressure of 0.47 atm for 60 minutes. The coating solution has a pH of 2.6 and a viscosity of 30 mPa at 25 ° C.
-It was s.

<< Preparation of Coating Solution for Upper Overcoat Layer >> Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 58.9 / 8.6 / 25.4 / 5.1 / 2
(Mass%) polymer latex solution (copolymer glass transition temperature 46 ° C. (calculated value), solid content concentration 21.5%,
Contains 100 ppm of compound A, compound D as a film-forming aid
15% by mass based on the solid content of the latex, the glass transition temperature of the coating solution is 24 ° C., and the average particle size is 116 nm.
Add water to 9g and add carnava wax (Chukyo Yushi Co., Ltd.)
Manufactured by Cellosol 524: 5pp as silicone content
18.4 g of a 30% by mass solution and 0.1% of compound C.
23 g, 1.85 g of compound E, 1.0 g of compound G,
3.45 g of matting agent (polystyrene particles, average particle diameter 7 μm, variation coefficient of average particle diameter 8%) and 26.5 polyvinyl alcohol (Kuraray Co., Ltd., PVA-235).
g, and water was further added to prepare a coating solution (containing 1.1% by mass of a methanol solvent). After completion, deaeration under reduced pressure was performed at a pressure of 0.47 atm for 60 minutes. The coating solution had a pH of 5.2 and a viscosity of 24 mPa · s at 25 ° C.

[0143]

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<< Preparation of Polyethylene Terephthalate (PET) Support with Back / Undercoat Layer >> (1) Preparation of PET Support Using terephthalic acid and ethylene glycol, the intrinsic viscosity IV = 0.66 (phenol / Tetrachloroethane = 6/4 (mass ratio) at 25 ° C) to obtain polyethylene terephthalate. This was pelletized, dried at 130 ° C. for 4 hours, and then melted at 300 ° C.
After being extruded from the die, it is quenched and the film thickness after heat setting is 12
An unstretched film having a thickness of 0 μm was produced.
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 horizontal direction at the same temperature. Then, after slitting the chuck portion of the tenter, knurling is performed on both ends to perform 4.8.
It was wound at kg / cm ² . Thus, the width 2.4
m, length 3500 m, thickness 120 μm, roll-shaped PE
A T support was obtained.

(2) Preparation of Undercoat Layer and Back Layer (2-1) Undercoat First Layer After subjecting the PET support to a corona discharge treatment at 0.375 kV · A · min / m ² , the composition shown below was obtained. Is applied on a support so as to have a concentration of 6.2 ml / m ^2.
C. for 30 seconds, 150.degree. C. for 30 seconds, and 185.degree. C. for 30 seconds. Latex-A 280 g KOH 0.5 g Polystyrene fine particles (average particle diameter: 2 μm, coefficient of variation of average particle diameter 7%) 0.03 g 2,4-dichloro-6-hydroxy-s-triazine 1.8 g Compound Bc-C 0 0.097g Distilled water Amount that total amount becomes 1000g

(2-2) Second layer of undercoat A coating solution having the composition shown below was applied on the first layer of undercoat so as to have a concentration of 5.5 ml / m ^2, and was applied at 125 ° C. for 30 seconds for 150 seconds.
It dried at 30 degreeC for 30 second and 170 degreeC for 30 second. Deionized gelatin (Ca ²⁺ content 0.6 ppm, jelly strength 230 g) 10 g acetic acid (20% aqueous solution) 10 g compound-Bc-A 0.04 g methylcellulose (2% aqueous solution) 25 g polyethyleneoxy compound 0.3 g distilled water Is 1000 g

(2-3) Back First Layer A 0.375 kV.multidot.
A · min / m ² of corona discharge treatment is applied, and a coating liquid having the following composition is applied to the surface so as to have a concentration of 13.8 ml / m ^2. Dry at 30 ° C. for 30 seconds. Julimer ET410 (30% aqueous dispersion, manufactured by Nippon Pure Chemical Co., Ltd.) 23 g Alkali-treated gelatin (molecular weight: about 10,000, Ca ²⁺ content: 30 ppm) 4.44 g Deionized gelatin (Ca ²⁺ content: 0.6 ppm) 84 g Compound-Bc-A 0.02 g Dye-Bc-A (adjusted so that the optical density at 783 nm is 1.3 to 1.4) As a guide 0.88 g Polyoxyethylene phenyl ether 1.7 g Sumitex Resin M -3 (8% aqueous solution) 15 g (water-soluble melamine compound, manufactured by Sumitomo Chemical Co., Ltd.) FS-10D (water dispersion of needle-like particles of Sb-doped SnO ₂ , manufactured by Ishihara Sangyo Co., Ltd.) 24 g polystyrene fine particles ( (Average particle size: 2 μm, coefficient of variation of average particle size: 7%) 0.03 g Distilled water Amount that gives a total amount of 1000 g

(2-4) Back second layer A coating solution having the composition shown below was applied on the back first layer so as to have a concentration of 5.5 ml / m ^2.
For 30 seconds and 170 ° C. for 30 seconds. Julimer ET410 (30% aqueous dispersion, manufactured by Nippon Pure Chemical Co., Ltd.) 57.5 g Polyoxyethylene phenyl ether 1.7 g Sumitex Resin M-3 (8% aqueous solution) 15 g (water-soluble melamine compound, Sumitomo Chemical ( Cellosol 524 (30% aqueous solution, manufactured by Chukyo Yushi Co., Ltd.) 6.6 g Distilled water Total amount of 1000 g

(2-5) Back Third Layer The same coating solution as that for the first undercoat layer was applied onto the second back layer so as to have a concentration of 6.2 ml / m ^2.
C. for 30 seconds and 185.degree. C. for 30 seconds.

(2-6) Fourth Back Layer A coating solution having the composition shown below was applied onto the third back layer so as to have a concentration of 13.8 ml / m ^2.
It dried at 30 degreeC for 30 second and 170 degreeC for 30 second. Latex-B 286 g Compound-Bc-B 2.7 g Compound-Bc-C 0.6 g Compound-Bc-D 0.5 g 2,4 dichloro-6-hydroxy-s-triazine 2.5 g Polymethyl methacrylate (10% aqueous dispersion Product, average particle diameter 5 μm, coefficient of variation of average particle 7%) 7.7 g distilled water Total amount is 1000 g

[0151]

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Latex-A: core-shell type latex core having 90% by weight of core and 10% by weight of shell, vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 93/3 /
3 / 0.9 / 0.1 (% by mass) Shell part Vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 88/3/3/3/3 (% by mass) Weight average molecular weight 38000 Latex-B: Methyl methacrylate / styrene / 2
-Ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 59/9/26/5/1
(% By mass of copolymer)

(3) Heat treatment for transport (3-1) Heat treatment PE thus prepared with a back / undercoat layer
The T support was placed in a heat treatment zone with a total length of 200 m set at 160 ° C., and transported at a tension of 2 kg / cm ² and a transport speed of 20 m / min. (3-2) Post-heat treatment After the heat treatment, post-heat treatment was performed by passing through a zone at 40 ° C for 15 seconds, and the film was wound. The winding tension at this time was 10 kg / cm ² .

<< Preparation of Photothermographic Material >> On the undercoat layer of the PET support on which the first undercoat layer and the second undercoat layer are coated, the method is disclosed in FIG. 1 of JP-A-2000-2964. The image forming layer coating solution was applied so as to have a coating silver amount of 1.5 g / m ² by using the slide beat coating method described above. Further, the coating solution for the protective layer was simultaneously and multi-layer coated with the coating solution for the image forming layer so that the solid content of the polymer latex was 1.29 g / m ² . Thereafter, the coating solution of the lower overcoat layer was coated on the protective layer with a solid content of the polymer latex of 1.97 g / m ^2.
The coating solution for the upper overcoat layer and the coating solution for the lower overcoat layer were simultaneously and simultaneously coated so that the coating amount of the solid content of the polymer latex was 1.07 g / m ² , thereby producing a photothermographic material. Drying during coating is a constant rate process,
Dry bulb temperature 75-76 ° C, dew point 14-25
℃, liquid film surface temperature 35 ~ 40 ℃, horizontal drying zone up to the drying point (the support in the horizontal direction of the coating machine 1.
(Angle of 5 ° to 3 °). Winding after drying was performed under the conditions of a temperature of 25 ± 5 ° C. and a relative humidity of 45 ± 10%, and the winding shape was adjusted to the subsequent processing form (image forming layer surface side outer winding), with the image forming layer surface side out. . The envelope relative humidity of the photosensitive material was 20 to 40% (measured at 25 ° C.), and the film surface pH on the image forming side of the obtained photothermographic material was 5.0 to 5.0.
1. The Beck smoothness was 720 to 760 seconds, the pH of the film surface on the opposite side was 5.9, and the Beck smoothness was 560 seconds.

<< Evaluation of Photographic Performance >> (Exposure Processing) The obtained photothermographic material was equipped with a semiconductor laser having a beam diameter (FWHM of ビ ー ム of the beam intensity) of 12.56 μm, a laser output of 50 mW, and an output wavelength of 783 nm. Using a single-channel cylindrical inner surface type laser exposure device, the exposure time is adjusted by changing the number of rotations of the mirror, and the exposure amount is changed by changing the output value.
Exposure was performed at x10 ^-8 seconds. At this time, the overlap coefficient was set to 0.449.

(Heat Developing Process) The exposed photothermographic material was subjected to a heat developing process using the heat developing machine shown in FIG. The material of the roller surface of the heat development processing section was silicon rubber, and the smooth surface was Teflon (registered trademark) nonwoven fabric. Table 7 shows the line speed of the transfer.
In the case of 0 cm / min, the preheating unit is 12.2 seconds (the driving system of the preheating unit and the heat development processing unit are independent, and the speed difference between the preheating unit and the heat development unit is set to -0.5% to -1% , The temperature setting of the metal roller of each preheating unit, the time is the first roller temperature 67 ℃,
2.0 seconds, second roller temperature 82 ° C, 2.0 seconds, third roller temperature 98 ° C, 2.0 seconds, fourth roller temperature 1
07 ° C, 2.0 seconds, fifth roller temperature 115 ° C, 2.0
At a temperature of 120 ° C. (temperature of the surface of the photothermographic material).
The heat development process was performed for 2 seconds and the slow cooling section for 13.6 seconds. The processing time here changes according to the line speed. In addition,
Temperature accuracy in the width direction was ± 0.5 ° C. The temperature of each roller was set to be 5 cm longer on both sides than the width of the photothermographic material (for example, 61 cm in width), and the temperature was applied to that portion so that the temperature accuracy was improved. Since the temperature at both ends of each roller is drastically lowered, the portion 5 cm longer than the width of the photothermographic material is 1 mm longer than the center of the roller.
The temperature was set so as to be higher by 3 ° C., and attention was paid so that the image density of the photothermographic material (for example, in a width of 61 cm) was uniform.

(Evaluation of Photographic Performance) The obtained images were evaluated using a Macbeth TD904 densitometer (visible density).
The results of the measurement were evaluated by the relative values of Dmin (fog), Dmax (maximum density) and the sensitivity (the reciprocal of the ratio of the exposure amount giving a density 1.5 times higher than Dmin). Was set to 100). The dependence of the line width sensitivity on the exposure amount was evaluated based on the change in the line width at an exposure amount twice as large as the standard exposure. Table 7 shows the results of the above evaluation performed for each photothermographic material.

[0158]

[Table 7]

Table 7 shows that when a photothermographic material having an average particle diameter of water-insoluble organic compound fine particles of less than 0.05 μm was processed at a line speed of 140 cm / min or more, fog (Dmin) was low and sufficient. Image density (Dm
It can be seen that the line width variation can be reduced while maintaining ax).

<Example 2><< Preparation of Photothermographic Materials 11-16 >> The silver halide emulsion used in the coating solution for the image forming layer was changed as shown in Table 8, except that:
Photothermographic materials 11 to 16 were prepared in the same manner as photothermographic materials 8 to 10 of Example 1.

<< Evaluation of Photographic Performance >> Exposure and thermal development treatments as in Example 1 were conducted at 24 ° C., 50% relative humidity and 20 ° C.
The test was performed in an environment with a relative humidity of 21%. The photothermographic material is allowed to age for at least 16 hours in that environment so that the water content of the photothermographic material is constant in that environment. Described in Table 8). Evaluation of the obtained image was performed using Macbeth TD90.
The measurement was performed using a 4 densitometer (visible density). The result of the measurement is D
The evaluation was made in terms of min (fog) and Dmax (maximum density), and the results are shown in Table 8.

[0162]

[Table 8]

As can be seen from Table 8, when the number average particle size of the silver halide is 0.08 μm or less, the fog (Dmin) is low regardless of the storage environment conditions of the photothermographic material, and it is very preferable for use in photoengraving. Image density (D
(max) 4.0 or more is maintained.

Example 3 << Preparation of Photothermographic Material 17 >> Photothermographic material 17 was prepared in the same manner as photothermographic material 10 of Example 1, except that the coating solution for the protective layer was changed as follows. Produced.

<< Preparation of Coating Solution for Protective Layer >> Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2
-Hydroxyethyl methacrylate / acrylic acid = 5
8.9 / 8.6 / 25.4 / 5.1 / 2 (% by mass) of a polymer latex solution (copolymer having a glass transition temperature of 46
° C (calculated), solids concentration 21.5%, compound A at 10
0 ppm, water was added to 943 g of a coating solution containing 15% by mass of the compound D based on the solid content of the latex, the glass transition temperature of the coating solution was 24 ° C., and the average particle diameter was 116 nm. Organic polyhalogen compound C
114.8 g of an aqueous solution, 17.0 g of an organic polyhalogen compound A (using a dispersion A) as a solid, 11.55 g of a development accelerator A (using a dispersion A) as a solid, sodium dihydrogen orthophosphate 0.69 g of dihydrate as solid content, matting agent (polystyrene particles, average particle size 7
1.58 g of polyvinyl alcohol (Kuraray Co., Ltd., PVA-23).
5) was added, and water was further added to prepare a coating solution (containing 0.9% by mass of a methanol solvent). After completion,
Vacuum deaeration was performed at a pressure of 0.47 atm for 60 minutes. The coating solution had a pH of 5.5 and a viscosity of 48 mPa · s at 25 ° C.

<< Preparation of Photothermographic Material 18 >> The photothermographic material 17 was prepared in the same manner as the photothermographic material 17 except that the coating solution for the protective layer was an organic polyhalogen compound A and a dispersion E was used as the development accelerator A. 18 were produced.

<< Evaluation of Photographic Performance >> The same evaluation as in Example 1 was performed (the line speed at the time of heat development is shown in Table 9). Table 9 shows the results.

[0168]

[Table 9]

As shown in Table 9, when a development accelerator was added to the protective layer, fog (Dmin) was low and sufficient image density (Dm) was obtained.
It can be seen that further acceleration can be performed while maintaining ax)

[0170]

According to the present invention, a high-speed photothermographic material having characteristics optimal for photoengraving applications, such as low fog (Dmin), high Dmax (maximum density), and a small width variation due to exposure, is provided. Provided. Further, the high-speed photothermographic material of the present invention can be prepared by aqueous coating which is advantageous in terms of environment and cost.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a configuration of a heat developing machine used for a heat development process of a high-speed photothermographic material according to the present invention.

[Explanation of symbols]

 Reference Signs List 10 high-speed 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

Claims (4)

[Claims] 1. A high-speed photothermographic material having an image forming layer containing a non-photosensitive silver salt, a photosensitive silver halide, a nucleating agent and a binder on at least one surface of a support, A high-speed photothermographic material, wherein the layer contains at least one solid fine particle of a water-insoluble organic compound, and the average particle diameter of the solid fine particles of each of the water-insoluble organic compounds is less than 0.05 μm. 2. The high-speed photothermographic material according to claim 1, wherein at least one of the solid fine particles is formed into fine particles by media dispersion using beads having an average particle size of 300 μm or less. 3. The photothermographic material according to claim 1, wherein the number average particle size of the photosensitive silver halide is 0.01 μm to 0.08 μm. 4. The high-speed photothermographic material according to claim 1, wherein the line speed is 140 to 700 cm /.
An image forming method, wherein heat development is performed in minutes.