JP2001075228A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat developable photosensitive material having high Dmax (maximum density), low fogging and photographic characteristics and a coated surface state optimum for a photomechanical process. SOLUTION: The heat developable photosensitive material has an image forming layer containing a nonphotosensitive silver salt, photosensitive silver halide, a binder and a nucleus forming agent on at least one face of a substrate and at least one protective layer on the image forming layer. The image forming layer is formed by coating with a coating fluid whose viscosity at 25 deg.C is 50-5,000 mPa.s at 0.1 s-1 shear rate and 1-100 mPa.s at 1,000 s-1 shear rate. The viscosity at 0.1 s-1 shear rate is higher than that at 1,000 s-1 shear rate. Not less than 50 wt.% of the binder of the protective layer is a polymer latex having 20-70 deg.C glass transition temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material, and more particularly to a scanner suitable for photolithography.
More specifically, a photothermographic material for an image setter has a high Dmax (maximum density) and a low fog, which makes it possible to obtain an image optimal for photolithography and has a good coated surface. It relates to a developed photosensitive material.

[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, there is a technique of forming an image by thermal development as a system that contributes to environmental preservation and can simplify the image forming means. In recent years, in the field of photolithography, it has been strongly desired to reduce the amount of processing waste liquid from the viewpoint of environmental conservation and space saving. Therefore, there has been a need to develop a technology relating to a photothermographic material for photoengraving, which can be efficiently exposed by a laser scanner or a laser imagesetter and can form a clear black image having high resolution and sharpness. is needed. According to such a photothermographic material, it is possible to supply a simpler and less environmentally harmful heat development processing system to a customer, which does not require a solution processing chemical.

A method of forming an image by thermal development is described in, for example, US Pat. Nos. 3,152,904 and 3,4,904.
57,075, and D.C. Morgan
an) and B.A. Shelly's "Thermal Pro Silver System (Thermally Pro
cessed Silver Systems) A "
(Imaging Processes and Materials
materials) Neblette Eighth Edition, Sturge, V.A. Wall Words
rth), A. Shepp Editing, Page 2,
1969). Such photothermographic materials typically comprise a non-photosensitive reducible silver source (eg, an organic silver salt), a catalytically active amount of a photocatalyst (eg, silver halide), and a silver reducing agent dispersed in an organic binder matrix. It is contained in a state. The photosensitive material is stable at room temperature, but when heated to a high temperature (for example, 80 ° C. or more) after exposure, silver is reduced through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and a reducing agent. Generate This oxidation-reduction reaction is promoted by the catalytic action of the latent image formed by the exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas becomes black and forms an image because it contrasts with the unexposed areas.

Conventionally known photothermographic materials are:
In many cases, the image forming layer is formed by applying a coating solution using an organic solvent such as toluene, methyl ethyl ketone (MEK), or methanol as a solvent. The use of an organic solvent as a solvent not only adversely affects the human body in the manufacturing process, but also disadvantageous in cost because a solvent recovery and other steps are required.

Accordingly, a method has been proposed in which an image forming layer is formed by using a coating solution containing water as a solvent. For example, JP-A-49-52626, JP-A-53-116144
Japanese Patent Application Publication No. JP-A-2005-133125 describes an image forming layer using gelatin as a binder. JP-A-50-151138 describes an image forming layer using polyvinyl alcohol as a binder. Further, JP-A-60-617
No. 47 describes an image forming layer using a combination of gelatin and polyvinyl alcohol. As another example, JP-A-58-28737 describes an image forming layer using water-soluble polyvinyl acetal as a binder. If such a binder is used, the image forming layer can be formed using a coating solution of a water solvent,
Environmental and cost benefits are significant.

However, when a polymer such as gelatin, polyvinyl alcohol, or water-soluble polyacetal is used as a binder, the silver tone of the developed part becomes brown or yellow, which is far from black which is originally preferable, and the blackening density of the exposed part is increased. And the density of the unexposed portion was high, and only those whose commercial value was significantly impaired were obtained. Further, there is also a problem that the compatibility with the organic silver salt is poor, and a coated material that can be practically used cannot be obtained due to the quality of the coated surface.

[0007] This problem can be solved by using a polymer latex. For example, International Publication WO97
/ 4355, JP-A-8-137045 and the like describe a method for preparing a heat-developable image forming material by aqueous coating using a polymer latex as a binder. However, a coating liquid using a polymer latex as a binder has a problem that the coating liquid has high fluidity, and a surface failure (wind unevenness) due to wind during drying is likely to occur. On the other hand, when a high-viscosity coating liquid is used so as to prevent the occurrence of wind unevenness, there is a problem that the coating property is remarkably deteriorated and a streak failure occurs. For this reason, environmental aspects,
There has been a demand for a technique for providing a heat-developable photosensitive material that is excellent in cost and is a water-based photosensitive material and has a good coated surface.

As means for responding to such a demand, Japanese Patent Application Laid-Open No. 11-52509 describes a viscosity of a thermal image forming coating solution in a thermal image forming material in the medical field. In addition, the publication does not disclose a system using a polymer latex for the protective layer.

[0009]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photothermographic material which has a good coated surface and excellent photographic properties for photoengraving, especially for scanners and imagesetters. It is in. A second object of the present invention is to provide a photothermographic material which can be applied in an aqueous system and is advantageous in terms of environment and cost.

[0010]

Means for Solving the Problems The present inventors have made intensive studies to solve the above problems, and as a result, formed an image forming layer or a protective layer using a coating solution having a specific viscosity,
Further, they have found that an excellent photothermographic material exhibiting the desired effect can be produced by using a polymer latex binder for the protective layer, and have provided the present invention.
That is, the present invention, on at least one surface of the support,
An image forming layer containing a non-photosensitive silver salt, a photosensitive silver halide, a binder and a nucleating agent, and a photothermographic material having at least one protective layer on the image forming layer,
The image forming layer has a viscosity at 25 ° C. at a shear rate of 0.1.
50 to 5000 mPa · s at s ⁻¹ , shear rate 10
The viscosity of the protective layer is ^{1 to} 100 mPa · s at 00 s ⁻¹ and the viscosity at a shear rate of 0.1 s ⁻¹ is higher than the viscosity at a shear rate of 1000 s ⁻¹ . A photothermographic material is provided, wherein 50% by weight or more of the binder is a polymer latex having a glass transition temperature of 20 to 70 ° C. In this specification, “to” means a range including numerical values described before and after it as a lower limit and an upper limit.

In the photothermographic material of the present invention, the protective layer has a protective layer of 2
The viscosity at 5 ° C has a shear rate of 0.1 s ^-1At 50-5
000mPa · s, shearing speed 1000s^-1In 1
100 mPa · s and a shear rate of 0.1 s^-1At
Viscosity is 1000s shear rate^-1Coating liquid higher than the viscosity at
It is preferable that it is applied using Also,
The photothermographic material of the present invention has a binder of the image forming layer.
50% by weight or more has a glass transition temperature of -30 ° C or more and 40
It is preferably a polymer latex at a temperature of not more than ° C.

Further, the photothermographic material of the present invention has the following formula:
At least one compound selected from the group consisting of a substituted alkene derivative represented by the following formula (1), a substituted isoxazole derivative represented by the following formula (2), and a specific acetal compound represented by the following formula (3): It is preferable that it is used as.

Embedded image [In the formula (1), R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or a substituent, and Z represents an electron-withdrawing group or a silyl group. In the formula (1), R ¹¹ and Z, R ¹² and R ¹³ , R ¹¹ and R ¹² , and R ¹³ and Z may be mutually bonded to form a cyclic structure. In the formula (2), R ¹⁴ represents a substituent. In the formula (3), X and Y
Each independently represents a hydrogen atom or a substituent, and A and B each independently represent an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic oxy group, a heterocyclic thio group or Represents a heterocyclic amino group. In the formula (3), X and Y, and A and B may be bonded to each other to form a cyclic structure. ]

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the heat development
The optical material will be described in detail. Photothermographic material of the present invention
The material is coated on at least one side of the support with a non-photosensitive silver salt.
(Preferably organic acid silver), photosensitive silver halide, vine
And an image forming layer containing a nucleating agent (ie, photosensitive
Layer) and at least one protective layer thereon. Picture
The surface opposite to the surface on which the image forming layer is formed (back
Surface) preferably has at least one back layer.
Good. The image forming layer of the photothermographic material according to the invention has 25
C viscosity is 0.1s^-150-50
00mPa · s, shearing speed 1000s^-1In 1 to 1
00 mPa · s and a shear rate of 0.1 s^-1Sticky in
Degree is shearing speed 1000s ^-1Coating liquid higher than the viscosity at
It is characterized in that it is applied and used. Like this
By controlling the viscosity of the image forming layer coating solution, the nucleating agent
Deterioration of photographic performance as a high contrast image forming material containing
An image-forming material having a good coated surface shape without
Can be Further, protection of the photothermographic material of the present invention.
50% by weight or more of the binder used for the layer
A polymer latex with a glass transition temperature of 70 ° C
There is a feature. Thus, the protective layer binder
By using polymer latex as an environmental
Water-based coating, which is advantageous in terms of surface and cost
You.

The coating solution for the image forming layer used in producing the photothermographic material of the present invention is a so-called pseudoplastic fluid.
The coating liquid for the protective layer used in producing the photothermographic material of the present invention is preferably a so-called pseudoplastic fluid. Pseudoplasticity is a property in which the viscosity decreases as the shear rate increases. The coating solution for the image forming layer used in producing the photothermographic material of the invention has a shear rate of 0.1 s ^{-1 at} 50 to 5000 mPa · s, preferably 50 to 3 mPa · s.
000 mPa · s, more preferably 100 to 1
It is 500 mPa · s. And ^{1 to} 100 mPa · s at a shear rate of 1000 s ⁻¹ , preferably 2 to 80 mP
a · s, more preferably 4 to 50 mPa · s.
The protective layer coating solution used in producing the photothermographic material of the present invention has a shear rate of preferably 0.1 to 50 mPa · s at 0.1 s ⁻¹ , and more preferably 50 to 5000 mPa · s.
3,000 mPa · s, more preferably 100 mPa · s.
Ｍ1500 mPa · s. And a shear rate of 1000 s
^-1 , preferably 1 to 100 mPa · s, more preferably 2 to 80 mPa · s, and still more preferably 4 to 50 mPa · s.
mPa · s. A conventional conventional photographic light-sensitive material or a coating solution of a photothermographic material using a benzotriazole silver salt has a shearing speed of 0.1 s ^-1 and 20 to 100 m.
Pa · s, 5 to 50 mPa · s at a shear rate of 1000 s ⁻¹
And was not a pseudoplastic liquid.

The viscosity at a shear rate of 0.1 s ^-1 is 50 m
When a photothermographic material is manufactured using an image forming layer coating solution of less than Pa · s, the viscosity of the coating solution is too low to cause wind unevenness due to drying air, so that a good surface state cannot be obtained. On the other hand, the viscosity at a shear rate of 0.1 s ^-1 is 5000
When a photothermographic material is produced using an image forming layer coating solution larger than mPa · s, the coating solution has an excessively high viscosity, causing coating streaks and failing to obtain a good surface state.
The viscosity at a shear rate of 0.1 s ^-1 is 50 mPa ·
When a photothermographic material is manufactured using a protective layer coating solution having a viscosity of less than s, the viscosity of the coating solution is too low, so that wind unevenness due to drying air tends to occur, and it tends to be impossible to obtain a good surface state. . On the other hand, when the viscosity at a shear rate of 0.1 s ^-1 is 500
When a photothermographic material is manufactured using a protective layer coating solution larger than 0 mPa · s, the viscosity of the coating solution is too high to cause coating streaks, and it tends to be impossible to obtain a good surface state. .

[0016] Shearing speed 1000s^-1At 1 m
Photothermographic material using an image forming layer coating solution of less than Pa · s
If a coating is manufactured, the viscosity of the coating solution is too low and
Wind unevenness occurs and a good surface condition cannot be obtained.
No. On the other hand, a shear rate of 1000 s ^-1Viscosity is 100
Heat generation using an image forming layer coating solution larger than mPa · s
When an image-sensitive material is manufactured, the viscosity of the coating solution is too high.
An application streak occurs, and a good surface state cannot be obtained.
In addition, a shearing speed of 1000 s^-1At a viscosity of 1 mPa
A photothermographic material is manufactured using a protective layer coating solution of less than s.
The viscosity of the coating solution is too low,
Tend to occur, and good surface conditions cannot be obtained.
You. On the other hand, a shear rate of 1000 s^-1Viscosity is 100
Thermal development feeling using protective layer coating liquid larger than mPa · s
When optical materials are manufactured, the viscosity of the coating solution is too high
There is a tendency that streaks occur and good surface conditions cannot be obtained.
is there.

In the present specification, the viscosity and the shear rate are defined as follows. Consider a model fluid that exists between two parallel planes. One of the two planes is fixed and the other is movable, and the distance between them is x. If a force F acts on the moving surface (upper surface) and the upper surface slides at a speed v with respect to the lower surface, the fluid layer between the two planes also causes a similar lateral displacement. The top fluid moves fastest and the bottom fluid moves slowest. The middle layer moves at an intermediate speed. But,
The velocity gradient dv / dx is the same for any part of the fluid. This velocity gradient γ is defined as a shear rate in this specification. In this model fluid, the total force acting on the upper surface (area A) is F, and the stress is F /
A. When this force is defined as a shear stress τ, the viscosity η in the present specification is defined by a ratio τ / γ between the shear stress and the shear rate. Any device may be used for measuring the viscosity.
Preferably, an FS fluid spectrometer is used. The measurement is performed at 25 ° C.

At least one of the protective layers constituting the photothermographic material of the present invention has a glass transition temperature of 20 to 70 ° C.
It is preferable to use the polymer latex as a binder. The polymer latex having a glass transition temperature of 20 to 70 ° C. is 50% by weight or more of the total binder of the protective layer,
It is preferable to use 70% by weight or more. Further, the polymer latex may be used not only for the protective layer, but also for the image forming layer and the back layer. It is preferable to use a polymer latex also for the back layer.

However, the "polymer latex" mentioned here
The term “water-insoluble hydrophobic polymer” means fine particles of a water-insoluble hydrophobic polymer dispersed 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" (edited by Tadashi Okuda and Hiroshi Inagaki, published by Polymer Publishing Association (19
78)), “Application of Synthetic Latex” (edited by Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, Polymer Publishing Association (1)
993)), "The Chemistry of Synthetic Latex" (Souichi Muroi,
Polymer Publishing Association (1970)). 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. There is no particular limitation on the particle size distribution of the dispersed particles, and they 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 the polymer latex having a normal uniform structure. In this case, it may be preferable to change the glass transition temperature of the core and the shell. 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 a protective layer or a back layer, a glass transition temperature of 20 to 70 ° C. is preferable for contacting various devices.

The minimum film forming temperature (MFT) of the polymer latex used in the present invention is preferably from -30 ° C to 90 ° C, more preferably from 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. For example, the above-mentioned "Synthetic Latex Chemistry (Souichi Muroi, published by Kobunshi Kankokai (1970)") )"It is described in.

The polymer used in the polymer latex used in the present invention includes acrylic resin, vinyl acetate resin, polyester resin, polyurethane resin, rubber resin, vinyl chloride resin, vinylidene chloride resin, polyolefin resin, or a copolymer thereof. And 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 protective layer is insufficient, and if it is too large, the film-forming property is poor, which is not preferable.

Specific examples of the polymer latex used as a binder for the protective layer constituting the 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 copolymer can be exemplified. More specifically,
Methyl methacrylate / ethyl acrylate / methacrylic acid = 33.5 / 50 / 16.5 (weight%) copolymer latex, methyl methacrylate / butadiene / itaconic acid = 47.5 / 47.5 / 5 (weight%) copolymer latex , Ethyl acrylate / methacrylic acid =
95/5 (% by weight) copolymer latex and the like.

Such a polymer is also commercially available. For example, as an acrylic resin, Sebian A-46 is used.
35, 46583, 4601 (all manufactured by Daicel Chemical Industries, Ltd.), Nipol LX811, 814, 82
1,820,857 (Nippon Zeon Co., Ltd.), VO
NCORT-R3340, R3360, R3370, 4
As polyester resins such as 280 (all manufactured by Dainippon Ink and Chemicals, Inc.), FINETEX ES650, 6
11,675,850 (Dai Nippon Ink Chemical Co., Ltd.)
HYDRAN as a polyurethane resin such as WD-size, WMS (all manufactured by Eastman Chemical)
LACSTAR is a rubber-based resin such as AP10, 20, 30, 40 (all manufactured by Dainippon Ink and Chemicals, Inc.).
7310K, 3307B, 4700H, 7132C (all manufactured by Dainippon Ink and Chemicals, Inc.), Nipol LX41
0, 430, 435, 438C (Zeon Corporation)
G351 and G576 as vinyl chloride resins.
(Nippon Zeon Co., Ltd.) and other vinylidene chloride resins such as L502 and L513 (both Asahi Kasei Corporation)
And Alon D7020, D504, and D5071 (all manufactured by Mitsui Toatsu Co., Ltd.), such as Chemipearl S120 and SA100 (all manufactured by Mitsui Petrochemical Co., Ltd.).
Manufactured). These polymers may be used alone or as a mixture of two or more as necessary.

Further, as a binder for the protective layer, paragraphs [0025] to [002] of Japanese Patent Application No. 11-6872.
A combination of polymer latexes having different I / O values obtained by dividing the inorganic value by the organic value based on the organic conceptual diagram described in 9 can be preferably used. In the present invention, if necessary, a plasticizer (for example, benzyl alcohol, 2,2,4-trimethylpentanediol-1,3-monoisobutylene) described in paragraph Nos. 0021 to 0025 of Japanese Patent Application No. 11-143058 may be used. Butyrate) can be added to control the film formation temperature. In addition, Japanese Patent Application No. 1
As described in Paragraph Nos. 0027 to 0028 of 1-6872, a hydrophilic polymer may be added to a polymer binder, and a water-miscible organic solvent may be added to a coating solution.

In the protective layer of the photothermographic material of the present invention, if necessary, hydrophilicity such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose and the like may be contained in an amount of 50% by weight or less of the whole binder. A polymer may be added. The amount of these hydrophilic polymers to be added is preferably 30% by weight or less, more preferably 15% by weight or less of the total binder in the protective layer. The protective layer of the photothermographic material of the invention is preferably prepared by applying an aqueous coating solution and then drying. However, the term "aqueous" as used herein means that 60% by weight or more of the solvent (dispersion medium) of the coating liquid is water. As components other than water of the coating solution, water-miscible organic solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate can be used.
As an example of a specific solvent composition, water / methanol = 90 /
10, water / methanol = 70/30, water / ethanol =
90/10, water / isopropanol = 90/10, water /
Dimethylformamide = 95/5, water / methanol / dimethylformamide = 80/15/5, water / methanol / dimethylformamide = 90/5/5 (however, the numbers represent weight%). The total amount of the binder for the protective layer used in the present invention is 0.2 to 10.0 g /
m ² , more preferably in the range of 0.5 to 6.0 g / m ² .

At least one of the image forming layers containing the photosensitive silver halide of the photothermographic material of the present invention is an image forming layer using the following polymer latex as 50% by weight or more of the total binder. Is preferred.
In the image forming layer of the present invention, the polymer latex is preferably used in an amount of 50% by weight or more of the total binder.
More preferably, the polymer latex is used in an amount of 70% by weight or more. The binder composition and coating method of such an image forming layer are the same as those of the protective layer. Further, as specific examples of the polymer latex for the image forming layer, any of the polymer latexes used for the protective layer are preferably used.

In the image forming layer of the present invention, if necessary, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose or the like is added in an amount of 50% by weight or less of the whole binder. May be. The amount of the hydrophilic polymer to be added is preferably 30% by weight or less, more preferably 15% by weight or less of the total binder in the image forming layer. The total amount of the binder for the image forming layer constituting the photothermographic material of the present invention is 0.2 to 30 g / m2.
² , more preferably in the range of 1.0 to 15 g / m ² . The total amount of the binder for the back layer constituting the photothermographic material of the present invention is preferably from 0.01 to 10.0 g / m ² , more preferably from 0.05 to 5.0 g / m ² .

Each of the layers is described in Japanese Patent Application No. 10-1996.
Use of a first polymer latex having a functional group introduced therein and a crosslinking agent having a functional group capable of reacting with the first polymer latex and / or a second polymer latex described in paragraph Nos. You can also. The functional group is a carboxyl group, a hydroxyl group, an isocyanate group, an epoxy group, an N-methylol group, an oxazolinyl group, and the like.As a crosslinking agent, an epoxy compound, an isocyanate compound, a blocked isocyanate compound, a methylol compound, a hydroxy compound, It is selected from a carboxyl compound, an amino compound, an ethyleneimine compound, an aldehyde compound, a halogen compound and the like. Specific examples of the cross-linking agent include hexamethylene isocyanate and duranate WB4 as isocyanate compounds.
0-80D, WX-1741 (manufactured by Asahi Kasei Corporation),
Bayhijur 3100 (Sumitomo Bayer Urethane Co., Ltd.)
Manufactured), Takenate WD725 (Takeda Pharmaceutical Co., Ltd.)
Aquanate 100, 200 (manufactured by Nippon Polyurethane Co., Ltd.), water-dispersible polyisocyanate described in JP-A-9-160172; Sumitex Resin M-3 as an amino compound (manufactured by Sumitomo Chemical Co., Ltd.) Denacol EX-614B (manufactured by Nagase Kasei Kogyo Co., Ltd.) as an epoxy compound; 2,4-dichloro- as a halogen compound
6-hydroxy-1,3,5-triazine sodium and the like.

The photothermographic material of the present invention may comprise two or more image forming layers, protective layers and back layers. 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, and there may be two or more layers. However, it is preferable to use a polymer latex for at least one layer, particularly the outermost back layer.

As used herein, the term "slip agent" 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 case where it is not present. The type is not particularly limited. Examples of the slip agent used in the present invention include paragraphs 0061 to 006 of JP-A-11-84573.
4. Paragraph No. 00 of Japanese Patent Application No. 11-106881
49 to 0062.
Specific examples of preferred lubricants include Cellolsol 524
(Main component carnauba wax), Polylon A, 393, H
-481 (main component polyethylene wax), Himicron G-110 (main component ethylenebisstearic acid amide), Himicron G-270 (main component stearic acid amide) (all manufactured by Chukyo Yushi Co., Ltd.), W-1 such as _{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 weight of the binder amount of the added layer, preferably 0.5 to 50% by weight.
30% by weight.

In the present invention, Japanese Patent Application No. 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.

The organic silver salt that can be used in the present invention is
Relatively stable to light, but forms a silver image when heated to 80 ° C. or higher 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. The organic silver salt can be any organic material including a source of reducible silver ions. Silver salts of organic acids,
Particularly (having 10 to 30 carbon atoms, preferably 15 to 28 carbon atoms)
Silver salts of long chain fatty carboxylic acids are preferred. The ligand is 4.0
Complexes of organic or inorganic silver salts having a complex stability constant in the range of from 10.0 to 10.0 are also preferred. The silver donor can preferably comprise about 5-70% by weight of the imaging layer. Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. In particular,
Examples thereof include, but are not limited to, silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the silver salt of an aliphatic carboxylic acid include:
Silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate, silver fumarate, silver tartrate, silver linoleate, silver butyrate and Silver camphorate and mixtures thereof 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 the 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 Japanese Patent Application No. 11-104187, paragraphs [0019] to [0019].
The method described in 0021 can be used.

In the present invention, a method of 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 to 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 type and amount of the dispersant used here are described in paragraph No. 00 of Japanese Patent Application No. 11-115457.
52 shows a specific example.

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 weight 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 and size of the organic silver salt which can be used in the present invention are not particularly limited.
It is preferable to use those described in paragraph 0024 of the specification of JP-A-187. The shape of the organic silver salt can be determined from a transmission electron microscope image of the organic silver salt dispersion. Another method for measuring monodispersity is to determine the standard deviation of the volume-weighted average diameter of the organic silver salt. The percentage (coefficient of variation) divided by the volume-weighted average diameter is preferably 80% or less, Preferably 50% or less, more preferably 30%
% Or less. As a measuring method, for example, the organic silver salt dispersed in a liquid is irradiated with a laser beam, and the autocorrelation function with respect to the time change of the fluctuation of the scattered light is obtained from the particle size (volume weighted average diameter). be able to. The average particle size in this measurement method is 0.1.
A solid fine particle dispersion of from 0.05 μm to 10.0 μm is preferred. A more preferred average particle size is 0.1 μm to 5.0.
μm, more preferably the average particle size is from 0.1 μm
2.0 μm. 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 an organic silver salt solid dispersion 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. It is preferable to use a dispersion method in which a water dispersion liquid which is not included in the liquid is converted into a high-speed flow and then the pressure is reduced. As for these dispersion methods, the methods described in paragraphs 0027 to 0038 of Japanese Patent Application No. 11-104187 can be used. The particle size distribution of the organic silver salt solid fine particle dispersion used in the present invention is preferably monodispersed. 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, and still 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 weight, and particularly preferably 10 to 30% by weight.
Although it is preferable to use the above-mentioned dispersing aid, it is preferable to use the dispersing aid in the minimum amount within a range suitable for minimizing the particle size.
A range of 15% by weight 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 non-photosensitive organic silver salt. Regarding addition of metal ions selected from Ca, Mg, Zn and Ag to the non-photosensitive organic silver salt,
It is preferably added in the form of a water-soluble metal salt which is not a halide, and specifically, it is preferably added in the form of a nitrate or a sulfate. 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 metal ions selected from Ca, Mg, Zn and Ag, which are preferably used in the present invention, are added after the particles of the non-photosensitive organic silver salt are formed, immediately after the particles are formed, before the dispersion, after the dispersion and in the preparation of the coating solution. The timing may be at any time as long as immediately before and after application, such as before and after, preferably after dispersion and before and after preparation of the coating solution. In the present invention, the addition amount of the metal ion selected from Ca, Mg, Zn and Ag is preferably 10 ^-3 to 10 ^-1 mol per mol of non-photosensitive organic silver, and particularly preferably 5 ×
It is preferably from 10 ^{−3 to} 5 × 10 ⁻² mol.

The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition, and may be silver chloride, silver chlorobromide,
Silver bromide, silver iodobromide, silver iodochlorobromide can be used. The grain formation of the photosensitive silver halide emulsion is described in paragraphs 0217 to 0217 of JP-A-11-119374.
The particles can be formed by the method described in H.224, but are not particularly limited to this method. The shapes of silver halide grains are cubic, octahedral, tetradecahedral,
Tabular, spherical, rod-like, potato-like and the like can be mentioned, and 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 described in JP-A-11-119374.
It is the same as that described in Paragraph No. 0225 of the publication. 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.
As the structure, core / shell particles having preferably a 2- to 5-layer structure, more preferably a 2- to 4-layer structure, can be used. 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 it contains a metal complex. Group VII of the periodic table
Or a group VIII metal or a central metal of a metal complex.
And preferably rhodium, rhenium, ruthenium, osuni
And iridium. Particularly preferred metal complexes are
(NH_Four)_ThreeRh (H_TwoO) Cl_Five, K_TwoRu (NO) C
l_Five, K_ThreeIrCl₆, K_FourFe (CN)₆It is. these
One kind of metal complex may be used,
May be used in combination of two or more. Preferred content is silver
1 × 10 per mole ^-9Mol ~ 1 x 10^-3Mole range
Preferably 1 × 10^-8Mol ~ 1 x 10^-FourThe mole range
Is more preferable. The structure of a specific metal complex is disclosed in
No. 225449 discloses a metal complex having a structure described in
Can be used. Depending on the type and addition method of these heavy metals
Regarding this, see paragraph number in JP-A-11-119374.
0227 to 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 in the present invention, it may or may not be desalted. . The photosensitive silver halide emulsion used in the present invention is preferably chemically sensitized. The chemical sensitization is described in JP-A-11-119374, paragraph 02.
It is preferable to use the methods described in JP-A-42-0250. The silver halide emulsion used in the present invention is prepared by the method described in EP-A-293,917.
A thiosulfonic acid compound may be added.

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 a coating solution containing an organic silver salt. 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 weight, but a concentration range of 5 to 15% by weight 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.

As the silver halide emulsion in the light-sensitive material used in the present invention, only one kind may be used, or two or more kinds may be used (for example, those having different average grain sizes, different halogen compositions, different crystal habits). And those having different chemical sensitization conditions) may be used in combination. The amount of the photosensitive silver halide used in the present invention is preferably from 0.01 mol to 0.5 mol, and more preferably from 0.01 mol to 0.5 mol per 1 mol of the organic silver salt.
02 mol to 0.3 mol is more preferable, and 0.03 mol to
0.25 mol is particularly preferred. 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, A method of mixing with a homogenizer or the like,
Alternatively, there is a method of preparing an organic silver salt by mixing a photosensitive silver halide which has been prepared at any timing during the preparation of the organic silver salt, and the like. Absent. 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.

Sensitizing dyes which can be used in the present invention are those capable of spectrally sensitizing silver halide grains in a desired wavelength range when adsorbed on silver halide grains, and are suitable for the spectral characteristics of an exposure light source. Sensitizing dyes having spectral sensitivity can be advantageously selected. For example, 550 nm to 750 n
Examples of dyes that spectrally sensitize the wavelength region of m include:
And dyes represented by the general formula (II) of JP-A-186572, specifically, II-6, II-7, II-14, and II.
Dyes -15, II-18, II-23 and II-25 can be exemplified as preferred dyes. Also, 750-1
Examples of the dye that spectrally sensitizes the wavelength region of 400 nm include the dye represented by the general formula (I) in JP-A-11-119374, and specifically, (25), (26),
(30), (32), (36), (37), (41),
The dyes (49) and (54) can be exemplified as preferred dyes. Further, as a dye forming a J-band, dyes described in Example 5 of U.S. Patent Nos. 5,510,236 and 3,871,887,
JP-A-2-96131, JP-A-59-48753
The dye disclosed in Japanese Patent Application Laid-Open Publication No. H10-15064 can be exemplified as a preferable dye. These sensitizing dyes may be used alone or in combination of two or more.

These sensitizing dyes can be added by the method described in paragraph No. 0106 of JP-A-11-119374, but it is not particularly 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 fogging performance, but is preferably 10 ^-6 to 1 mol, more preferably 1 mol per mol of silver halide in the photosensitive layer. Is 10
^-4 to 10 ^-1 mol.

According to the present invention, in order to improve the spectral sensitization efficiency,
Supersensitizers can be used. Examples of the supersensitizer used in the present invention include European Patent Publication No. 587,338, US Pat. No. 3,877,943, and US Pat.
873, 184, compounds selected from heteroaromatic or aliphatic mercapto compounds, heteroaromatic disulfide compounds, stilbene, hydrazine, and triazine. 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 the formula:
Stilbene compounds represented by the general formula (I) of JP-A No. 1111543, and compounds represented by the general formula (I) of JP-A No. 11-109747. Specifically, compounds of M-1 to M-24 of JP-A-5-341432,
D-1) to d-14) of JP-A-4-18239.
The compound of SS-0 of JP-A-10-111543
Compounds Nos. 1 to SS-07, 31, 32, 37, 38, 41 to 45 and 51 to 5 in JP-A-11-109747.
3 compound. The addition amount of these supersensitizers is preferably in the range of 10 ^-4 to 1 mol per mol of silver halide in the emulsion layer, and 0.001 to 1 mol per mol of silver halide.
A range of 0.3 mole is more preferred.

Next, the nucleating agent used in the present invention will be described. The type of nucleating agent used in the present invention is not particularly limited, but as a preferred 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) of Japanese Patent Application Laid-Open No. 10-10672,
JP-A-161270, JP-A-10-62898, JP-A-9-304870, JP-A-9-304
No. 872, JP-A-9-304871, JP-A-10-31282, U.S. Pat. No. 5,496,69
No. 5, and all hydrazine derivatives described in European Patent Publication No. 741,320.
Further, substituted alkene derivatives, substituted isoxazole derivatives and specific acetal compounds represented by formulas (1) to (3) described in Japanese Patent Application No. 11-87297,
More preferably, a cyclic compound represented by Formula (A) or Formula (B) described in the same specification, specifically, 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, Japanese Patent Application No. 9-2825
Compounds described in JP-A-64-64, JP-A-11-95365, JP-A-11-95366, and Japanese Patent Application No. 9-332388 may be used.

In the present invention, in order to form a super-high contrast image, a high contrast accelerator can be used in combination with the nucleating agent. 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 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 of the photothermographic material having the image forming layer containing the photosensitive silver halide is preferably 5 mmol or less, more preferably 1 mmol or less per mole of silver. .

In the photothermographic material of the present invention, an acid or a salt thereof formed by hydration of diphosphorus pentoxide is preferably used in combination with a nucleating agent. Acids or salts thereof formed by hydration of diphosphorus pentoxide include metaphosphoric acid (salt), pyrophosphoric acid (salt), orthophosphoric acid (salt), triphosphoric acid (salt), tetraphosphoric acid (salt), hexametaline Acids (salts) 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 to
100 mg / m ² is more preferred.

The photothermographic material of the present invention preferably contains a reducing agent for an organic silver salt. The reducing agent for the organic silver salt 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 preferably contained in an amount of 5 to 50 mol%, more preferably 10 to 40 mol%, per 1 mol of silver on the surface having the image forming layer. The layer to which the reducing agent is added may be any layer on the image forming layer side with respect to the support. When added to a layer other than the image forming layer, 10 to 50 mol% based on 1 mol of silver
It is preferable to use a relatively large amount. Further, the reducing agent may be a so-called precursor which is derivatized so as to function effectively only during development.

In a photothermographic material utilizing an organic silver salt, a wide range of reducing agents can be used. For example,
JP-A-46-6074, JP-A-47-1238, JP-A-47-33621, JP-A-49-46427, JP-A-49-115540, and JP-A-50-1433.
No. 4, No. 50-36110, No. 50-147
Nos. 711 and 51-32632 and 51-1
Nos. 023721, 51-32324, and 5
1-51933, 52-84727, 55-108654, 56-146133, 57-82828, 57-82829, JP-A-6-3793, U.S.A. Patent No. 3,67
9,426, 3,751,252, 3,751,255, 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 692,732 and the like are used. be able to. For example, amide oximes such as phenylamidooxime, 2-thienylamidooxime and p-phenoxyphenylamidooxime; azines such as 4-hydroxy-3,5-dimethoxybenzaldehydeazine; 2,2'-bis (hydroxymethyl) propionyl A combination of an aliphatic carboxylic acid aryl hydrazide such as a combination of β-phenylhydrazine and ascorbic acid and ascorbic acid; a combination of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine (for example, hydroquinone and bis (ethoxy) Ethyl) hydroxylamine, piperidinohexose reductone or a combination of formyl-4-methylphenylhydrazine, etc.); phenylhydroxamic acid, p-hydroxyphenylhydroxam And hydroxamic acids, such as β- ants Nin hydroxamic acid;
A combination of azine and sulfonamidophenol (for example, phenothiazine and 2,6-dichloro-4-benzenesulfonamidophenol); α such as ethyl-α-cyano-2-methylphenylacetate, ethyl-α-cyanophenylacetate A cyanophenylacetic acid derivative; 2,2′-dihydroxy-1,1′-binaphthyl,
6,6′-dibromo-2,2′-dihydroxy-1,
Bis-β-naphthol as exemplified by 1′-binaphthyl and bis (2-hydroxy-1-naphthyl) methane; bis-β-naphthol and 1,3-dihydroxybenzene derivatives (eg, 2,4-dihydroxybenzophenone Or 5-pyrazolone such as 3-methyl-1-phenyl-5-pyrazolone; dimethylaminohexose reductone, anhydrodihydroaminohexose reductone and anhydrodihydro Reductones as exemplified by piperidone hexose reductone; sulfonamide phenol reducing agents such as 2,6-dichloro-4-benzenesulfonamidophenol and p-benzenesulfonamidophenol; 2-phenylindane-1,
Chromanes such as 2,2-dimethyl-7-tert-butyl-6-hydroxychroman; 2,6
1,4-dihydropyridines such as -dimethoxy-3,5-dicarbethoxy-1,4-dihydropyridine; bisphenols (for example, bis (2-hydroxy-3-te)
rt-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, it may be added by any method such as an aqueous solution, an organic solvent solution, a powder, a solid fine particle dispersion, and an emulsified dispersion. The dispersion of the solid fine particles is carried out by a known fine means (for example, ball mill, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

In the present invention, as a development accelerator, Japanese Patent Application No.
A phenol derivative represented by the formula (A) described in -73951 is preferably used. The phenol derivative represented by the formula (A) exhibits a strong development promoting effect when used in combination with the above reducing agent. Specifically, A-1 to A-54 described in the same specification are preferably used. Formula (A)
The phenol derivative represented by
It is preferably used in the range of mol% to 100 mol%, and more preferably in the range of 0.1 mol% to 20 mol%. The phenol derivative represented by the formula (A) may be added to a layer on the image forming layer side with respect to the support, that is, the image forming layer or any other layer on the layer side.
It is preferable to add it to the layer containing the reducing agent. The phenol derivative represented by the formula (A) may be added by any method such as an aqueous solution, an organic solvent solution, powder, solid fine particle dispersion, and emulsified dispersion. The dispersion of the solid fine particles is carried out by a known fine means (for example, ball mill, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

When an additive known as a "toning agent" for improving an image is included, the optical density may be increased.
The toning agent may also be advantageous in forming a black silver image. The 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. In a photothermographic material using an organic silver salt, a wide range of color toning agents can be used. 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,
JP-A-50-2524, JP-A-50-32927,
Nos. 50-67132, 50-67641, 50-114217, 51-3223, 51-27923, and 52-14788.
JP-A-52-99813, JP-A-53-1020
JP-A-53-76020 and JP-A-54-1565.
Nos. 24, 54-156525 and 61-1
No. 83642, JP-A-4-56848, JP-B-49-10727, JP-A-54-20333, U.S. Pat.
446,648, 3,782,941 and 4,123,282, 4,51
No. 0,236, British Patent No. 1,380,795, 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 quinazolinone, 3-phenyl-2-pyrazolin-5.
Cyclic imides such as -one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione; naphthalimides (eg, N-hydroxy-1,8-naphthalimide); cobalt complexes (eg, cobalt hexamine trifluoroacetate) ); 3-mercapto-1,
2,4-triazole, 2,4-dimercaptopyrimidine, 3-mercapto-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, peracids Disulfide 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 toning 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 photothermographic material of the present invention before the heat development processing is preferably 6.0 or less, more preferably 5.5 or less. The lower limit is not particularly limited, but is about 3. The adjustment of the film surface pH is preferably performed using an organic acid such as a phthalic acid derivative, a nonvolatile acid such as sulfuric acid, or a volatile base such as ammonia from the viewpoint of reducing the film surface pH. In particular, ammonia is preferable in achieving a low film surface pH since ammonia is easily volatilized and can be removed before the application step and the heat development. Note that the film surface p
The method for measuring H is described in paragraph No. 0123 of Japanese Patent Application No. 11-87297.

In the photothermographic material of the present invention, the silver halide emulsion and / or the organic silver salt may contain an antifoggant,
Stabilizers and stabilizer precursors can further protect against the formation of additional fog and stabilize against reduced sensitivity during storage in inventory. Suitable antifoggants, stabilizers and stabilizer precursors, which can be used alone or in combination, are described in US Pat. No. 2,131,03.
No. 8, No. 2,694,716, azaindenes described in U.S. Pat. Nos. 2,886,437 and 2,444,605, U.S. Pat. No. 2,728,663, mercury salts described in U.S. Pat. No. 3,287,135, urazole described in U.S. Pat. No. 3,287,135, U.S. Pat. No. 3,235,652.
Patent No. 62, UK Patent No. 62
Oxime, nitrone, nitroindazole described in US Pat. No. 3,448, polyvalent metal salt described in US Pat. No. 2,839,405, US Pat. No. 3,220,839.
No. 2,566,263 and U.S. Pat. No. 2,597,9.
15, palladium, platinum and gold salts described in US Pat. No. 4,108,665 and US Pat.
No. 4,128,557 and U.S. Pat. Nos. 4,137,079 and 4,138,365.
And the phosphorus compounds described in US Pat. No. 4,411,985.

The 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, but a preferred example is described in US Pat.
No. 939, No. 4,152,160, JP-A-9-329863, JP-A-9-329864, and JP-A-9-281637. The benzoic acid may be added to any layer of the 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 to 2 mol, more preferably 1 × 10 ^-3 mol to 0.5 mol, per 1 mol of silver.

Although not essential for practicing the present invention,
It may be advantageous to add a mercury (II) salt as an antifoggant to the image forming layer. Preferred mercury (II) salts for this purpose are mercury acetate and mercury bromide. The added amount of mercury used in the present invention is as follows.
It is preferably in the range of 1 × 10 ⁻⁹ mol to 1 × 10 ⁻³ mol, more preferably 1 × 10 ⁻⁸ mol to 1 × 10 ⁻⁴ mol per mol. An antifogging agent particularly preferably used in the present invention is an organic halide.
Nos. 0-119624, 50-120328, 51-121332, 54-58022
JP-A-56-70543, JP-A-56-9933
No. 5, No. 59-90842, No. 61-129
642, 62-129845, JP-A-6-129845
-208191, 7-5621, 7-
Nos. 2781, 8-15809, U.S. Pat. No. 5,340,712, and 5,369,000.
And compounds disclosed in US Pat. No. 5,464,737. Japanese Patent Application No. 11-872
No. 97, a hydrophilic organic halide represented by the formula (P) is preferably used as an antifoggant.
Specifically, (P-1) to (P-11) described in the same specification
8) is preferably used. The addition amount of the organic halide is a mol amount (mol / molA) relative to 1 mol of Ag.
g), preferably 1 × 10 ^{−5 to 2} mol / mo
lAg, more preferably 5 × 10 ^{-5 to} 1 mol / mol
Ag, more preferably 1 × 10 ^{-4 to} 5 × 10 ^-1 mol
/ 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, methanol, etc.).
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 photothermographic material of the present invention contains a mercapto compound, a disulfide compound, and a thione compound for the purpose of controlling or suppressing the development by improving or improving the preservability before and after the development. Can be. 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 one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably, the heteroaromatic ring is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, pyridazine , Pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring can be, for example, halogen (eg, Br and Cl), hydroxy, amino, carboxy, alkyl (eg, having one or more carbon atoms, preferably 1-4 carbon atoms), alkoxy ( For example, it may have a substituent selected from the group consisting of one or more carbon atoms, preferably those having 1 to 4 carbon atoms, and aryl (which may have a substituent). Good. Examples of the mercapto-substituted heteroaromatic compound include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole,
6-ethoxy-2-mercaptobenzothiazole, 2,
2'-dithiobis- (benzothiazole), 3-mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2- Mercaptoquinoline, 8-mercaptopurine,
2-mercapto-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,5
6-tetrachloro-4-pyridinethiol, 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate, 2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto- 1,2,
4-triazole, 4-hydrokilocy-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-diamino-2-mercaptopyrimidine, 2-mercapto-4-
Methyl pyrimidine hydrochloride, 3-mercapto-5
-Phenyl-1,2,4-triazole, 1-phenyl-5-mercaptotetrazole, sodium 3- (5-mercaptotetrazole) -benzenesulfonate, N-
Methyl-N '-{3- (5-mercaptotetrazolyl)
Examples include phenyl diurea and 2-mercapto-4-phenyloxazole, but the present 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.

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 No. 0020 of Japanese Patent Application No. 10-221039
To 0037, it is preferable to provide an undercoat layer containing a vinylidene chloride copolymer containing 70% by weight or more of a vinylidene chloride monomer repeating unit described in paragraphs 0063 to 0080 of Japanese Patent Application No. 11-106881. .

When the amount of the vinylidene chloride monomer is less than 70% by weight, 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. When such a repeating unit is contained, the polymer (polymer) is crystallized by using only the vinylidene chloride monomer, so that it is difficult to form a uniform film when the moisture-proof layer is applied, and the polymer ( This is because a carboxyl group-containing vinyl monomer is indispensable for the stabilization of the polymer). The molecular weight of the vinylidene chloride copolymer used in the present invention is 4 by weight average molecular weight.
5,000 or less, or 10,000 to 45,000
Is preferred. 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. The thickness (per layer) of the undercoat layer is generally 0.01 to 5 μm, more preferably 0.05 to 1 μm.

Various supports can be used for the 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. The support used in the photothermographic material of the present invention is described in
48772, JP-A-10-10676, JP-A-10-10677, JP-A-11-65025
In order to alleviate the internal strain remaining in the film at the time of biaxial stretching described in Japanese Patent Application Laid-open No.
Polyester, particularly polyethylene terephthalate, which has been subjected to a heat treatment in a temperature range of 0 to 185 ° C is preferably used. 120 ° C. of the support after such heat treatment,
The dimensional change rate by heating for 30 seconds is -0.0 in the vertical direction (MD).
03% to + 0.01%, lateral direction (TD) is 0 to 0.04
%.

The photothermographic material of the present invention has been disclosed in JP-A No. 11-84573, paragraphs 0040 to 0051, for the purpose of reducing dust adhesion, preventing the generation of static marks, and preventing defective transport in the automatic transport step. Can be prevented by using the conductive metal oxide and / or the fluorine-based surfactant described in (1). Examples of the conductive metal oxide include U.S. Pat. No. 5,575,957 and Japanese Patent Application No. 10-04.
Needle-shaped conductive tin oxide doped with antimony described in paragraphs 0012 to 0020 of JP-A-1302 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 10 Ω in an atmosphere of 25 ° C. and 20% relative humidity.
¹¹ Ω or less is good. 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 photothermographic material of the invention and the outermost layer surface opposite to the surface, preferably both, is 2,000 seconds or less, and more preferably 10 seconds or less. 2000 seconds. The Beck smoothness in the present invention is based on Japanese Industrial Standard (JIS).
It can be easily obtained according to P8119 “Smoothness test method of paper and paperboard with Beck tester” and TAPPI standard method T479. The Beck smoothness of the outermost layer having the image forming layer of the photothermographic material and the outermost layer on the opposite side thereof is described in paragraph No. 0 of JP-A-11-84573.
As described in 052-0059, 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 coatability, 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 sulfinic acid or its copolymer, polyacrylic acid or its copolymer, acrylic acid or its copolymer, etc. , Maleic acid copolymer, maleic acid monoester copolymer, acryloylmethylpropanesulfonic acid or a copolymer thereof).

Among these, water-soluble polymers preferably used include gelatin, dextran, dextrin,
Methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, polyethylene glycol, polypropylene glycol, polystyrene sulfonic acid or a copolymer thereof, acryloylmethylpropane sulfonic acid or a copolymer thereof, and particularly thickening It is preferably used as an agent. Among these, particularly preferred thickeners include gelatin, dextran, methylcellulose, hydroxyethylcellulose, polyvinyl alcohol, polyacrylamide, polyvinylpyrrolidone, polystyrenesulfonic acid and copolymers thereof. 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 weight, more preferably 0.05 to 20% by weight, and particularly preferably 0.1 to 10% by weight. 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, and typical examples are 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 ⁽⁺⁾ (C
H 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 -C
H 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 light-sensitive material using gelatin as a main binder, it 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. Is 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 liquid in which the main component of the binder is a polymer latex, the flow of the coating liquid cannot be stopped by rapid cooling, so that the preliminary drying may be insufficient only in the first drying zone. .
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 at least until the constant-rate drying is completed, irrespective of the first drying zone or the second drying zone as described in Japanese Patent Application No. 10-282949. Is a method of drying in a horizontal drying 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 moisture content at which the transition from the constant rate process to the rate reduction process is 200 to 300%. 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, the 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 it 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 100 mPa · s at 25 ° C.
And more preferably 30 to 70 mPa · s. On the other hand, the coating liquid viscosity of the protective layer is 5 to 75 m at 25 ° C.
Pa · s is preferred, and more preferably 20 to 50 mP
a · s. These viscosities are measured by a B-type viscometer.

Winding after drying is preferably performed under the conditions of a temperature of 20 to 30 ° C. and a relative humidity of 45 ± 20%. Good or inside. 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. The relative humidity of the photosensitive material is 20 to
It is preferable to control the temperature within a range of 55% (measured at 25 ° C.).

In a conventional photographic emulsion coating solution which is a viscous solution 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 it is returned, there is almost no occurrence of bubbles. 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, the method described in JP-B-55-6405 (page 4, line 20 to page 7, line 11) is preferable. As an apparatus for performing such defoaming, an apparatus shown in the embodiment of Japanese Patent Application No. 10-290003 and the apparatus shown in FIG. 3 can be preferably used.

The pressure 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, paragraphs 0204 to 0208, Japanese Patent Application No.
Paragraph Nos. 0240 to 024 of 1-106881 specification
A dye can be contained for the purpose of preventing halation as described in 1. Color tone improvement in the image forming layer,
Various dyes and pigments can be used from the viewpoint of prevention of irradiation. Although any dyes and pigments can be used for the image forming layer, see, for example, JP-A-11-1193.
The compound described in paragraph No. 0297 of JP-A-74 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 it is generally preferable to use them in the range of 1 × 10 ⁻⁶ g to 1 g per 1 m ² .

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, a compound described in paragraph No. 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 photothermographic material of the present invention is used as a mask when preparing a printing plate using a PS plate after the heat development, the photothermographic material after the heat development is subjected to exposure conditions for the PS plate in a plate making machine. Information to set,
Information for setting plate-making conditions such as a transfer condition of a mask original and a PS plate is carried as image information. Therefore, the above-mentioned irradiation dye, halation dye,
The concentration (use amount) of the filter dye is limited to read them. Since this information is read by LED or laser, Dm of the sensor wavelength range
In (minimum concentration) 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. uses a light source having a wavelength of 670 nm as a detector and a bar code reader for detecting a register mark. The plate making machine APM manufactured by Shimizu Seisakusho Co., Ltd.
A 670 nm light source is used as an L series barcode reader. That is, Dmin around 670 nm
When the (lowest density) is high, the information on the film cannot be detected accurately, and a work error occurs in the plate making machine such as a conveyance failure and an exposure failure. 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, it is 0.25 or less. The lower limit is not particularly limited, but is usually about 0.10.

In the present invention, the exposure apparatus used for imagewise exposure may be any apparatus capable of performing exposure with an exposure time of less than 10 ^-7 seconds, but is generally a laser diode (LD) or a light emitting diode. An exposure apparatus using (LED) as a light source is preferably used. In particular, LD has high output,
More preferable in terms of 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. 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. The overlap can be quantitatively expressed by FWHM / sub-scanning pitch width (overlap coefficient), for example, when the beam diameter is represented by a half width of beam intensity (FWHM). In the present invention, the overlap coefficient is preferably 0.2 or more.

The scanning method of the light source of the exposure apparatus used in the present invention is not particularly limited, and a cylinder outer surface scanning method, a cylinder inner surface scanning method, a plane scanning method, or the like can be used. Also,
The channel of the light source may be a single channel or a multi-channel, but in the case of a cylindrical outer surface type, a multi-channel is preferably used. The photothermographic material of the present invention has a low haze at the time of exposure and tends to cause interference fringes.
As a technique for preventing the occurrence of this interference fringe, Japanese Unexamined Patent Application Publication No. 5-113
No. 548 and the like, a technique for obliquely entering a laser beam into a photosensitive material, and a technique disclosed in International Publication WO 95
A method using a multi-mode laser disclosed in, for example, Japanese Patent No. 31754 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 image development is carried out by elevating the temperature of the photothermographic material exposed imagewise. As a preferred embodiment of the thermal developing machine used, a type in which the photothermographic material is brought into contact with a heat source such as a heat roller or a heat drum is disclosed in Japanese Patent Publication No. 5-56499, Japanese Patent Application Laid-Open No. 9-292695, and Japanese Patent Application Laid-Open No. 9-297385. JP-A-7-13294 as a non-contact type heat developing machine described in Japanese Patent Application Publication No.
JP, WO97 / 28489, 97
And JP-A-28488 / 97 and JP-A-97 / 28487. A particularly preferred embodiment is a non-contact type thermal developing machine. A preferred development temperature is 80
To 250 ° C, more preferably 100 to 140 ° C
It is. The development time is preferably 1 to 180 seconds, and is preferably 1 to 180 seconds.
0 to 90 seconds is more preferred. As a method of preventing processing unevenness due to dimensional change of the photothermographic material during thermal development, an image is not formed at a temperature of 80 ° C. or more and less than 115 ° C., and after heating for 5 seconds or more, at 110 ° C. to 140 ° C. It is effective to adopt a method of forming an image by thermal development (a so-called multi-stage heating method).

When the photothermographic material of the present invention is subjected to thermal development processing, it is exposed to a high temperature of 110 ° C. or more, so that a part of the components contained in the material or a part of the components decomposed by thermal development are removed. 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 Publication WO95 / 30933, 97
Japanese Patent Application Laid-Open No. 21150/1990 and Japanese Patent Application Laid-Open No. 10-500496 disclose a filter cartridge having a first opening for introducing volatile components and having a binding opening and a second opening for discharging a volatile component. It is described to be used for a heating device for heating by heating. In addition, International Publication WO96 / 1
Japanese Patent Application Laid-Open No. 2213 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 in the heat developing process of the 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 includes a carry-in roller pair 11 (an upper roller is a silicon rubber roller and a lower roller is an aluminum heat roller) for carrying the heat-developable photosensitive material 10 into a heating unit while correcting and preheating the heat-developable photosensitive material 10 into a planar shape. It has a carry-out roller pair 12 that carries out the heat-developable photothermographic material 10 after the heat development to a flat shape and carries it out of the heating unit. The photothermographic material 10 has a carry-in roller pair 1
The toner is thermally developed while being conveyed from No. 1 to the discharge roller pair 12. In the conveying means for conveying the photothermographic material 10 during the heat development, a plurality of rollers 13 are provided on the side where the surface having the image forming layer contacts, and the non-woven fabric (for example, A smooth surface 14 on which an aromatic polyamide or Teflon) is attached is provided.
The back surface of the photothermographic material 10 is smoothed by driving a plurality of rollers 13 in contact with the surface having the image forming layer.
4 while being slid. A heater 15 is provided above the roller 13 and below the smooth surface 14 so as to heat the photothermographic material 10 from both sides. As a heating means in this case, a plate heater or the like can be used. The clearance between the roller 13 and the smooth surface 14 varies depending on the member of the smooth surface, but is appropriately adjusted to a clearance that allows the photothermographic material 10 to be transported. Preferably 0
１1 mm.

Material of Roller 13 Surface and Smooth Surface 1
The member 4 is durable at high temperatures and may be anything as long as it does not hinder the conveyance of the photothermographic material 10, but the material of the roller surface is silicon rubber, and the member of the smooth surface is made of aromatic polyamide or Teflon (PTFE). Non-woven fabrics are preferred. It is preferable to use a plurality of heaters as the heating means and to set the heating temperature freely. The heating unit 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 heat development photosensitive material 10. It is preferable to set the temperature higher than the glass transition temperature (Tg) so that unevenness in development does not occur. The temperature distribution between the preheating section and the heat development section is preferably ± 1 ° C. or less, more preferably ± 0.5 ° C. or less. 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.
Cooling is preferably performed gradually so that the photothermographic material 10 is not deformed.
0.5 to 10C / sec is 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.

[0099]

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 >> Alkali-treated gelatin (calcium content: 2700 pp) was added to 700 ml of water.
m), 11 g, potassium bromide 30 mg, and sodium 4-methylbenzenesulfonate 1.3 g were dissolved, and the pH was adjusted to 6.5 at 40 ° C. 159 ml of an aqueous solution containing 18.6 g of silver nitrate, 1 mol / l of potassium bromide, and (NH ₄ ) ₂ RhCl
₅ (H ₂ O) at 5 × 10 ⁻⁶ mol / l and K ₃ I
an aqueous solution containing 2 × 10 ⁻⁵ mol / l of rCl ₆ ,
While maintaining the pAg at 7.7, it was added over 6 minutes and 30 seconds by the control double jet method. Then, silver nitrate 55.
476 ml of an aqueous solution containing 5 g and a halogen salt aqueous solution containing 1 mol / l of potassium bromide and 2 × 10 ^-5 mol / l of K ₃ IrCl ₆ by a control double jet method for 28 minutes and 30 seconds while keeping the pAg at 7.7. And added. Thereafter, the pH was lowered to perform coagulation sedimentation and desalting treatment, and 51.1 g of low molecular weight gelatin having an average molecular weight of 15,000 (calculated as 20 ppm or less) was added to adjust the pH to 5.9 and the pAg to 8.0. The obtained particles had an average particle size of 0.08 μm and a projected area variation coefficient of 9
%, (100) cubic grains having a 90% face ratio. The silver halide grains thus obtained were heated to 60 ° C.
76 moles of sodium benzenethiosulfonate per mole of silver
After 3 minutes, 71 μmol of triethylthiourea was added, and the mixture was aged for 100 minutes.
6-methyl-1,3,3a, 7-tetrazaindene is converted to 5
× 10 ^-4 mol, after adding 0.17 g of compound A, 40 ° C.
The temperature was lowered. 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.

[0101]

Embedded image

<< Preparation of Silver Behenate Dispersion A >> Behenic acid (Edenor C22-85R, manufactured by Henkel)
6 g, 423 ml of distilled water, 5N-NaOH aqueous solution
2 ml and tert-butyl alcohol 120 ml
Were mixed and reacted at 75 ° C. with stirring for 1 hour to obtain a sodium behenate solution. Separately, silver nitrate 40.4
g of an aqueous solution (206.2 ml) was prepared and kept at 10 ° C. 635 ml of distilled water and tert-butyl alcohol 3
The reaction vessel containing 0 ml was kept at 30 ° C., and the whole amount of the sodium behenate solution and the whole amount of the silver nitrate aqueous solution were added at a constant rate over 62 minutes, 10 seconds and 60 minutes while stirring. At this time, 7 minutes after the start of the addition of the aqueous silver nitrate solution 2
For 0 second, only the silver nitrate aqueous solution was added, and after 7 minutes and 20 seconds, the addition of the sodium behenate solution was started.
For 9 minutes and 30 seconds after the completion of the addition of the aqueous silver nitrate solution, only the sodium behenate solution was added. At this time, the temperature in the reaction vessel was set at 30 ° C., and the temperature was controlled so as not to rise. In addition, 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 tube. The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution. After the addition of the sodium behenate solution was completed, the mixture was left to stir at the same temperature for 20 minutes, and the temperature was lowered to 25 ° C. Thereafter, the solid content was separated by suction filtration, and the conductivity of the solid content was 30 μS / c.
m. The solid thus obtained was stored as a wet cake without drying. The morphology of the obtained silver behenate grains was evaluated by electron microscopy. Was.

Next, a dispersion of silver behenate was prepared by the following method. For a wet cake having a dry solid content of 100 g, polyvinyl alcohol (trade name: PVA-21)
(7, average degree of polymerization: about 1,700) 7.4 g and water were added to make the total amount 385 g, and the mixture was predispersed with a homomixer. Next, the predispersed undiluted solution is dispersed in a dispersing machine (Microfluidizer M-110S manufactured by Microfluidics International Corporation).
-EH, G10Z interaction chamber) pressure was adjusted to 1750 kg / cm ² and treated three times,
A silver behenate dispersion A was obtained. As a cooling means, coiled heat exchangers were installed before and after the interaction chamber, respectively, and the desired dispersion temperature was set by adjusting the temperature of the refrigerant. The silver behenate particles contained in the silver behenate dispersion A thus obtained have a volume-weighted average diameter of 0.52 μm.
m, particles having a variation coefficient of 15%. Particle size measurements are available from Malvern Instruments Ltd.
d. The measurement was performed with MasterSizerX manufactured by KK. When evaluated by electron microscopy, the ratio of the long side to the short side was 1.
5, the grain thickness was 0.14 μm, and the average aspect ratio (the ratio of the circle equivalent diameter of the projected area of the grain to the grain thickness) was 5.1.

<< Preparation of Solid Fine Particle Dispersion of Reducing Agent >> As a reducing agent, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane 10
kg and 10 kg of a 20% by weight aqueous solution of a modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval MP203) were added with 16 kg of water and mixed well to form a slurry. This slurry was sent by a diaphragm pump, and was fed for 3 hours by a horizontal sand mill (UVM-2, manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm.
After dispersing for 0 minute, 4 g of benzoisothiazolinone sodium salt and water were added to adjust the concentration of the reducing agent to 25% by weight to obtain a solid fine particle dispersion of the reducing agent. The reducing agent particles contained in the dispersion thus obtained had a median diameter of 0.44 μm, a maximum particle diameter of 2.0 μm or less, and a coefficient of variation of the average particle diameter of 19%. 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 of Organic Polyhalogen Compound A >> 10 kg of organic polyhalogen compound A [tribromomethyl (4- (2,4,6-trimethylphenylsulfonyl) phenyl) sulfone], modified polyvinyl alcohol ( 10 kg of a 20% by weight aqueous solution of Kuraray Co., Ltd., Poval MP203), 639 g of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate,
Surfynol 104E (Nissin Chemical Co., Ltd.) 400
g, 640 g of methanol and 16 kg of water were added and mixed well to form a slurry. The slurry was sent by a diaphragm pump, and dispersed in a horizontal sand mill (UVM-2, manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 5 hours. The concentration of A was adjusted to 25% by weight to obtain a solid fine particle dispersion of the organic polyhalogen compound A. The organic polyhalogen compound particles contained in the dispersion thus obtained had a median diameter of 0.36 μm.
m, the maximum particle diameter was 2.0 μm or less, and the variation coefficient of the average particle diameter was 18%. 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 of Organic Polyhalogen Compound B >> 5 kg of organic polyhalogen compound B [tribromomethylnaphthyl sulfone], 20 parts of modified polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.)
A 2.5% by weight aqueous solution, 213 g of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate, and 10 kg of water were added and mixed well to form a slurry. The slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2 manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 5 hours, and then benzoisothiazolinone sodium salt was added. 5 g and water were added to adjust the concentration of the organic polyhalogen compound B to 20% by weight to obtain a solid fine particle dispersion of the organic polyhalogen compound B. The organic polyhalogen compound particles contained in the dispersion thus obtained had a median diameter of 0.38 μm, a maximum particle diameter of 2.0 μm or less, and a coefficient of variation of the average particle diameter of 20%. 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 of Compound Z >> 3.5 kg of R-054 manufactured by Sanko Co., Ltd. containing 85% by weight of compound Z was added to a modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.). ) 1kg and water 15kg
Was added and mixed well to obtain a slurry. This slurry is fed by a diaphragm pump and has an average diameter of 0.5 mm.
Was dispersed in a horizontal sand mill (UVM-2, manufactured by Imex Co., Ltd.) filled with zirconia beads for 7 hours, and water was added to adjust the concentration of compound Z to 10% by weight. A fine particle dispersion was obtained. The particles of compound Z contained in the dispersion thus obtained had a median diameter of 0.45 μm, a maximum particle diameter of 4.0 μm or less, and a coefficient of variation in particle diameter of 17%. 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 Dispersion of 6-Isopropylphthalazine Compound >> A modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval MP) was stirred at room temperature with 87.9 g of water.
203) 2.0 g was added so as not to form a lump, and stirred and mixed for 10 minutes. Thereafter, the mixture was heated to raise the internal temperature to 50 ° C., and then stirred for 1 hour to be uniformly dissolved. 4 internal temperature
The temperature was lowered to 0 ° C. or lower, 3.0 g of a 20% aqueous solution of sodium tripropylnaphthalenesulfonate and 7.14 g of 6-isopropylphthalazine (70% aqueous solution) were added, and the mixture was stirred for 30 minutes to obtain a transparent dispersion. Was. 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 as a dispersion of a 6-isopropylphthalazine compound.

<< Preparation of Solid Fine Particle Dispersion of Nucleator >> Table 1
1 kg of modified polyvinyl alcohol (Poval PVA-217, manufactured by Kuraray Co., Ltd.) for 4 kg of the nucleating agent described in
g and 36 kg of water were added and mixed well to form a slurry. This slurry was sent by a diaphragm pump, and was fed to a horizontal sand mill (UVM-2, manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm.
After dispersion for 2 hours, 4 g of benzoisothiazolinone sodium salt and water were added to adjust the nucleating agent concentration to 10% by weight to obtain a solid fine particle dispersion of the nucleating agent. The particles of the nucleating agent contained in the dispersion thus obtained had a median diameter of 0.34 μm, a maximum particle diameter of 3.0 μm or less, and a coefficient of variation in particle diameter of 19%. The resulting dispersion had a pore size of 3.0.
Filtration was performed with a μm polypropylene filter to remove foreign substances such as dust, and stored.

<< Preparation of Coating Solution for Image Forming Layer >> The following binders and materials were used for 1 mol of silver of the silver behenate dispersion A prepared above (2 mol of silver for only samples 9 and 10 in Table 1). , And silver halide emulsion A, and
The amount of water was adjusted so as to obtain the viscosity described in (1) to prepare a coating solution for the image forming layer. After completion, degas under reduced pressure at -350
Performed at mmHg for 60 minutes. The physical properties of the coating solution at 25 ° C. were pH 7.7 and shear viscosity as shown in Table 1.

Binder Amount shown in Table 1 as solid content (Lackstar 3307B, manufactured by Dainippon Ink and Chemicals, Inc., glass transition temperature of 17 ° C. with SBR latex) 1,1-bis (2-hydroxy-3,5) -Dimethylphenyl) -3,5,5-trimethylhexane 149 g as solid content Organic polyhalogen compound A 43.5 g as solid content Organic polyhalogen compound B 13.5 g as solid content Sodium ethylthiosulfonate 0.30 g Benzo Triazole 1.04 g Polyvinyl alcohol (PVA-235, manufactured by Kuraray Co., Ltd.) Amount shown in Table 1 6-isopropylphthalazine 12.8 g Sodium dihydrogen orthophosphate dihydrate 0.37 g Compound Z Solid content 9.7 g nucleating agent (type shown in Table 1) 0.0 as solid content 3 mol Dye A (added as a mixture with low molecular weight gelatin having an average molecular weight of 15,000) Coating amount at which optical density at 783 nm becomes 0.3 (approximately 0.37 g) Silver halide emulsion A Ag amount is 0. 06 mol Compound C 2.0 g Compound A as preservative 40 ppm in coating solution (2.5 mg / m ² as coating amount) Methanol 2 wt% as total solvent amount in coating solution Ethanol 1 wt% as total solvent amount in coating solution (The glass transition temperature of the coating film was 17 ° C.)

[0112]

Embedded image

[0113]

Embedded image

<< Preparation of Coating Solution for Lower Protective Layer >> Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid =
58.9 / 8.6 / 25.4 / 5.1 / 2 (% by weight) of a polymer latex solution (copolymer having a glass transition temperature of 4
6 ° C. (calculated value), solid content concentration 21.5%, compound A 1
Water was added to 943 g of a coating solution containing 15 ppm by weight of the compound D as a film-forming auxiliary, based on the solid content of the latex, and a glass transition temperature of the coating solution of 24 ° C.).
g, matting agent (polystyrene particles, average particle diameter 7 μm, variation coefficient of average particle diameter 8%) 1.98 g, and polyvinyl alcohol (Kuraray Co., Ltd., PVA-235) 29.4.
g, and water was further added to prepare a coating solution (containing 2% by weight of a methanol solvent). After preparing the coating liquid, deaeration under reduced pressure was performed at -400 mmHg for 60 minutes. Physical properties of the coating solution at 25 ° C. are pH 5.5 and shear viscosity 0.1 s ^−1.
Was 300 mPa · s and 1000 s ⁻¹ was 17 mPa · s.

<< Preparation of Coating Solution for Upper Protective Layer >> Methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid =
58.9 / 8.6 / 25.4 / 5.1 / 2 (% by weight) of a polymer latex solution (copolymer having a glass transition temperature of 4
6 ° C. (calculated value), solid content concentration 21.5%, compound A 1
Water was added to 649 g containing 00 ppm, compound D as a film-forming aid, 15% by weight based on the solid content of the latex, and a glass transition temperature of the coating solution of 24 ° C.). Carnauba wax (Chukyo Yushi Co., Ltd .; 524: less than 5 ppm as silicone content) 6.30 g of a 30% by weight solution,
0.23 g of compound C, 7.95 g of compound F, 0.93 g of compound G, 1.8 g of compound H, and a matting agent (polystyrene particles, average particle diameter 7 μm, coefficient of variation of average particle diameter 8)
%) And polyvinyl alcohol (PVA-235, manufactured by Kuraray Co., Ltd.) were added, and water was further added to prepare a coating solution (containing 1.5% by weight of a methanol solvent). After coating solution preparation, degas under reduced pressure -400 m
Performed at mHg for 60 minutes. The physical properties of the coating solution at 25 ° C. were 200 mP at a pH of 2.8 and a shear viscosity of 0.1 s ⁻¹ .
The ^value was 7 mPa · s at a · s and 1000 s ⁻¹ .

[0116]

Embedded image

<< Preparation of Polyethylene Terephthalate (PET) Support Having Back / Undercoat Layer >> (1) Preparation of PET Support According to a conventional method, terephthalic acid and ethylene glycol were used, and the intrinsic viscosity was 0.66 (phenol / tetrachloroform). (Measured at 25 ° C. in ethane = 6/4 (weight ratio)). After pelletizing this, 13
After drying at 0 ° C. for 4 hours, the mixture was melted at 300 ° C., extruded from a T-die, rapidly cooled, and heat-fixed to a thickness of 120 μm.
An unstretched film having a thickness such that This was longitudinally stretched 3.3 times at 110 ° C. using rolls having different peripheral speeds, and then horizontally stretched 4.5 times at 130 ° C. using a tenter. Thereafter, after heat-setting at 240 ° C. for 20 seconds, it was relaxed by 4% in the lateral direction at the same temperature. After this, after slitting the chuck part of the tenter, knurling is performed on both ends,
The film was wound at 4.8 kg / cm ² . Thus, a roll-shaped PET support having a width of 2.4 m, a length of 3,500 m, and a thickness of 120 μm was obtained.

(2) Formation of Undercoat Layer and Back Layer (2-1) First Layer of Undercoat A coating solution having the following composition was applied on a support so as to have a concentration of 6.2 ml / m ² , 30 seconds, 30 minutes at 150 ° C
And dried at 185 ° C. for 30 seconds. Latex-A 280 g KOH 0.5 g Polystyrene fine particles (average particle size: 2 μm, coefficient of variation of average particle size 7%) 0.03 g 2,4-dichloro-6-hydroxy-s-triazine 1.8 g Distilled water Total 1, 000g

(2-2) Undercoating second layer A coating solution having the composition shown below was applied on the undercoating first layer 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 Methyl cellulose (2% aqueous solution) 25 g Polyethyleneoxy compound 0.3 g Distilled water Total 1 2,000g

(2-3) Back First Layer The surface opposite to the surface on which the undercoat layer is coated is 0.375 kV ·
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) 84g Compound-Bc-A 0.02g Dye-Bc-A (adjusted to an optical density of 1.33 to 1.4 at 783 nm) As a guide 0.88g Polyoxyethylene phenyl ether 1.7g Water soluble melamine compound (Sumitec Resin M-3 (8% aqueous solution, manufactured by Sumitomo Chemical Co., Ltd.)) 15 g Sb-doped SnO ₂ aqueous dispersion of needle-shaped particles (Ishihara Sangyo Co., Ltd., FS-10D) 24 g Polystyrene fine particles ( (Average particle size: 2 μm, coefficient of variation of average particle size: 7%) 0.03 g Distilled water A total amount of 1,000 g

(2-4) Back second layer A coating solution having the composition shown below was applied on the back first layer so as to be 5.5 ml / m ^2, and was applied at 125 ° C. for 30 seconds at 150 ° C.
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 Water-soluble melamine compound (manufactured by Sumitomo Chemical Co., Ltd., Sumitex Resin M-3 (8%) Aqueous solution)) 15 g cellosol 524 (30% aqueous solution, manufactured by Chukyo Yushi Co., Ltd.) 6.6 g distilled water A total amount of 1,000 g

(2-5) Back Third Layer A coating liquid having the same composition as the coating liquid for the first undercoat layer was used.
Apply ² ml / m ² on back second layer to 12 ml / m ²
Drying was performed at 5 ° C. for 30 seconds, 150 ° C. for 30 seconds, and 185 ° 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 of 1,000 g

[0124]

Embedded image

Latex-A: A core-shell type latex having a core part of 90% by weight and a shell part of 10% by weight Core part: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 93
/3/3/0.9/0.1 (% by weight) Shell part: vinylidene chloride / methyl acrylate / methyl methacrylate / acrylonitrile / acrylic acid = 8
8/3/3/3/3 (% by weight) Weight average molecular weight 38000 Latex-B: methyl methacrylate / styrene / 2
-Ethylhexyl acrylate / 2-hydroxyethyl methacrylate / acrylic acid = 59/9/26/5/1
(% By weight of copolymer)

(3) Heat treatment for transportation (3-1) Heat treatment The PET support having the back / undercoat layer prepared was
It was placed in a heat treatment zone having a total length of 200 m set at 60 ° 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 >> A slide beat coating method shown in FIG. 1 of Japanese Patent Application No. 10-292849 was applied onto the undercoating second layer of a PET support.
The coating solution for the image forming layer shown in Table 1 was applied so that the applied silver amount was 1.5 g / m ² . The lower protective layer coating solution was further coated with a solid content of 1.31 g of the polymer latex.
/ M ² with the coating solution for the image forming layer. Thereafter, the coating liquid for the upper protective layer was coated on the lower protective layer with a solid content of 3.02 g / polymer latex.
and m ^2, and the coating was prepared photothermographic material (Sample No. 1 to No. 10). Drying at the time of coating is carried out at a constant bulb process and a deceleration process at a dry bulb temperature of 70 to 75 ° C and a dew point of 8 to 25.
C. and a liquid film surface temperature of 35 to 40.degree. C. in a horizontal drying zone (at an angle of 1.5 to 3 degrees with respect to the horizontal direction of the coating machine). Winding after drying was carried out under the conditions of 25 ± 5 ° C. and 45 ± 10% relative humidity, 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 relative humidity of the photothermographic material is 20 to
At 40% (measured at 25 ° C.), the film surface pH on the image forming side of the obtained photothermographic material was 5.0, the Beck smoothness was 850 seconds, and the film surface pH on the opposite side was 5.9. Smoothness is 5
60 seconds.

<< Measurement of Shear Viscosity of Coating Solution >> The shear viscosities of the prepared image forming layer coating solution and protective layer coating solution were measured using a measuring device (RFS Fluid Spectrometer, manufactured by Rheometrics Far East Co., Ltd.). It was measured at 25 ° C.

<< Evaluation of Coated Surface State >> The coated surface state of the obtained coated sample was visually evaluated in five steps from the state of occurrence of coating streaks and coating unevenness. A rating of 5 is the best, and a rating of 3 or more represents a surface state that can withstand practical use.

<< Exposure Treatment >> A heat-developable photosensitive material having a coated surface state that can withstand practical use (score of 3 or more) was prepared with a beam diameter (FWHM of ビ ー ム of beam intensity) of 12.56 μm and a laser output of 50.
Using a single-channel cylindrical inner surface type laser exposure device equipped with a semiconductor laser having an output wavelength of 783 nm, the exposure time is adjusted by changing the number of rotations of the mirror, and the exposure amount is adjusted by changing the output value. hand,
Exposure was at 2 × 10 ⁻⁸ seconds. At this time, the overlap coefficient was set to 0.449.

<< Heat Development >> The exposed photothermographic material was subjected to a heat development using the heat developing machine shown in FIG. The roller surface material of the thermal development processing section is made of silicone rubber, and the smooth surface is made of Teflon nonwoven fabric.
2 mm / sec, pre-heating unit 14.4 seconds (the driving systems of the pre-heating unit and the heat development processing unit are independent, and the speed difference between the pre-heating unit and the heat development unit is set to -0.5% to -1%. The set temperature and time of the metal roller of the preheating section are as follows.
The second roller was at 82 ° C. for 2.4 seconds and the third roller was at 98
2.4 seconds at 107 ° C., 2.4 seconds at 107 ° C., 2.4 seconds at 115 ° C., 12 seconds at 115 ° C.
The temperature of the photothermographic processing section was 20.3 seconds at 120 ° C. (temperature of the photothermographic material surface), and that of the slow cooling section was 16 seconds (16 seconds continuously from 120 ° C. to 60 ° C.). The heat development was performed at a cooling rate of -3.75 ° C./sec. The temperature accuracy in the width direction was ± 0.5 ° C. The setting of each roller temperature depends on the width of the photothermographic material (for example, width 6).
5 cm longer on both sides than 1 cm), and a temperature was applied to that portion so that the temperature accuracy was improved. In addition,
Since the temperature at both ends of each roller is drastically reduced, the temperature of the photothermographic material (for example, width) is set so that the portion 5 cm wide from both ends of the photothermographic material is 1-3 ° C. higher than the center of the roller. Care was taken that the image density (within 61 cm) was a homogeneous finish.

<< Evaluation of Photographic Performance >> The obtained images were evaluated using a Macbeth TD904 densitometer (visible density).
Evaluation was made based on Dmin (fog) and Dmax (maximum density).

<< Results >> Table 1 shows the results of the above evaluations performed on each photothermographic material.

[0134]

[Table 1]

From Table 1, it is found that the shear viscosity is 50 to 5000 mPa · s at 0.1 s ^{−1 and} 1000 s ⁻¹
(Nos. 1 to 7) prepared using an image forming layer coating solution in the range of 1 to 100 mPa · s.
It can be seen that each of them has a high coating density, low fog, and a good coated surface state that can withstand practical use. In particular, it is 100 to 1500 mPa · s at 0.1 s ⁻¹ and 100
Samples prepared using an image forming layer coating solution in the range of 4 to 50 mPa · s at 0 s ⁻¹ (No. 1 to No. 1)
The coated surface condition of 5) was very good.

<Example 2><< Preparation of Coating Solution for Image Forming Layer >>
An image forming layer coating solution having the same composition as in Example 1 was prepared. << Preparation of coating solution for lower protective layer >> A coating solution was prepared in the same manner as in Example 1 except that the amount of water and the amount of polyvinyl alcohol added were adjusted to adjust the shear viscosity of the coating solution as shown in Table 2. << Preparation of Coating Solution for Upper Protective Layer >> A coating solution was prepared in the same manner as in Example 1 except that the amount of water and the amount of polyvinyl alcohol added were adjusted to adjust the shear viscosity of the coating solution as shown in Table 2. << Preparation of Photothermographic Material >> A photothermographic material was prepared in the same manner as in Example 1 except that the above coating solution was used. << Evaluation and results >> Example 1 for each photothermographic material
The same evaluation as described above was performed, and the results are shown in Table 2.

[0137]

[Table 2]

From Table 2, it can be seen that the shear viscosity is 50 to 5000 mPa · s at 0.1 s ^{−1 and} 1000 s ⁻¹
No. 11 to 13, samples prepared using the protective layer coating solution in the range of 1 to 100 mPa · s.
Nos. 6 to 18) all have a high density and low fog, indicating that the coated surface is good for practical use. In particular, 0.
A 100~1500mPa · s at 1s ^-1, and samples prepared using the protective layer coating solution is in the range of 4~50mPa · s at 1000 s ^-1 (No.
The coated surface conditions of 11 and 16) were very good.

[0139]

The photothermographic material of the present invention has a Dmax
(Highest density), low fog, and optimum photographic properties and coated surface for photolithography. Further, the photothermographic material of the present invention can be produced 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 the configuration of a heat developing machine used for a heat development process of a photothermographic material according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 10 photothermographic material 11 carry-in roller pair 12 carry-out roller pair 13 roller 14 smooth surface 15 heating heater 16 guide plate A preheating section B heat development processing section C slow cooling section

Claims (4)

[Claims] 1. An image forming layer containing a non-photosensitive silver salt, a photosensitive silver halide, a binder and a nucleating agent on at least one surface of a support, and at least one layer on the image forming layer. A photothermographic material having a protective layer, wherein the image forming layer has a viscosity at 25 ° C. of a shear rate of 0.1.
50 to 5000 mPa · s at s ⁻¹ , shear rate 10
A 1 to 100 mPa · s at 00s ^-1, and a viscosity at a shear rate of 0.1s ^-1 is Coating with higher coating liquid than the viscosity at a shear rate of 1000 s ^-1, and the binder of the protective layer Is a polymer latex having a glass transition temperature of from 20 to 70 ° C. 2. The protective layer has a viscosity at 25 ° C. of 50 to 5000 mPa · s at a shear rate of 0.1 s ⁻¹ , 1 to 100 mPa · s at a shear rate of 1000 s ⁻¹ , and a shear rate of 0.1 to 100 mPa · s. The viscosity at 1 s ^-1 is a shear rate of 100
2. The photothermographic material according to claim 1, wherein the photothermographic material is applied using a coating solution having a viscosity higher than 0s ^-1 . 3. The photothermographic material according to claim 1, wherein 50% by weight or more of the binder in the image forming layer is a polymer latex having a glass transition temperature of −30 ° C. to 40 ° C. material. 4. At least one selected from a substituted alkene derivative represented by the following formula (1), a substituted isoxazole derivative represented by the following formula (2), and a specific acetal compound represented by the following formula (3) 4. The photothermographic material according to claim 1, wherein one kind of compound is used as a nucleating agent. Embedded image [In the formula (1), R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or a substituent, and Z represents an electron-withdrawing group or a silyl group. In the formula (1), R ¹¹ and Z, R ¹² and R ¹³ , R ¹¹ and R ¹² , and R ¹³ and Z may be mutually bonded to form a cyclic structure. In the formula (2), R ¹⁴ represents a substituent. In the formula (3), X and Y
Each independently represents a hydrogen atom or a substituent, and A and B each independently represent an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, a heterocyclic oxy group, a heterocyclic thio group or Represents a heterocyclic amino group. In the formula (3), X and Y, and A and B may be bonded to each other to form a cyclic structure. ]