JP2002169249A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material used for a medical image or for a photomechanical process and giving an image having a good color tone (close to a pure black tone). SOLUTION: In the heat developable photosensitive material containing at least one photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one face of a support, (a) at least one polyphenol compound of formula (I) is contained as the reducing agent, (b) at least one hindered phenol compound of formula (II) is contained and (c) the molar ratio of the compound of the formula (II) to the compound of the formula (I) is 0.001-0.2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material.

[0002]

2. Description of the Related Art In recent years, in the field of medical diagnostic films and photoengraving films, there has been a strong demand for reduction of processing waste liquid from the viewpoint of environmental protection and space saving. Therefore, heat development is possible as a medical diagnostic film and a photoengraving film that can be efficiently exposed by a laser imagesetter or a laser imager and can form a clear black image having high resolution and sharpness. There is a need for techniques relating to photosensitive materials. According to these photothermographic materials, a photothermographic processing system that does not require solution-based processing chemicals and is simpler and does not damage the environment can be supplied to customers. There is a similar demand in the field of general image forming materials, but especially for medical diagnostic images, a fine description is required, so that sharpness, high image quality with excellent granularity are required, and diagnosis is easy. From the viewpoint, there is a feature that a cool tone image is preferred. At present, various hard copy systems using pigments and dyes, such as ink jet printers and electrophotographs, are distributed as general image forming systems, but none of them is satisfactory as a medical image output system.

On the other hand, thermal image forming systems utilizing organic silver salts are disclosed in, for example, US Pat. Nos. 3,152,904 and 3,457,075 and D.C. Crosta Bohr (Kl
osterboer) "Thermal Processed Silver System (Ther
mally Processed Silver Systems) "(Imaging
Processings and Materials (Imaging Proce
sses and Materials) Neblette Eighth Edition, J. Sturge (Stu
rge), V. Walworth, A. Shep
p) Compilation, Chapter 9, p. 279, 1989). In particular, the photothermographic material generally contains a catalytically active amount of a photocatalyst (for example, silver halide), a reducing agent, a reducible silver salt (for example, an organic silver salt), and if necessary, a color tone agent for controlling the color tone of silver. And a photosensitive layer dispersed in a binder matrix. After the image exposure, the photothermographic material is heated to a high temperature (for example, 80 ° C. or higher), and a black silver image is formed by a redox reaction between a reducible silver salt (which functions as an oxidizing agent) and a reducing agent. Form. The oxidation-reduction reaction is promoted by the catalytic action of the latent image of silver halide generated by exposure. Therefore, a black silver image is formed in the exposed area. It is disclosed in many documents including U.S. Pat. No. 2,910,377 and JP-B-43-4924.

A pure black tone is desired for a medical diagnostic image. However, it is difficult to produce a pure black tone with a thermal image forming system using this organic silver salt, and the tone is adjusted with the above-mentioned tone agent or the like. However, the color tone control is not enough and improvement is desired. In addition, processing by rapid development is desired for use in emergency hospitals, etc., but the image obtained by rapid development has a less pure black tone than the image obtained by the normal development time, and further color tone improvement is required. was there.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. More specifically, the present invention provides a photothermographic material for use in medical images or photoengraving, which is capable of obtaining an image having a good color tone (close to a pure black tone). Was a problem to be solved.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, by using a specific reducing agent and a specific compound in combination, an intended effect can be obtained. It has been found that a preferable photothermographic material can be produced, and the present invention has been completed. That is, according to the present invention, in a photothermographic material containing at least one kind of photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions, and a binder on one surface of a support, a) containing at least one polyphenol compound represented by the following general formula (I) as the reducing agent;
(B) a compound containing at least one hindered phenol compound represented by the following general formula (II), and (c) a compound represented by the general formula (I) which is a compound represented by the general formula (II) The photothermographic material is provided, wherein the ratio (molar ratio) to the photothermographic material is 0.001 to 0.2.

Embedded image (In the general formula (I), R ¹¹ and R ¹¹ ′ each independently represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. R ¹² and R ¹² ′ each independently represent a hydrogen atom or a benzene ring. .L representing a substitutable group -S- group or a -CHR ¹³ - a represents a group .R ¹³ is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms .X ¹ and X ¹ 'Each independently represents a hydrogen atom or a group that can be substituted on a benzene ring.)

Embedded image (In the general formula (II), R ¹ .R ² is hydrogen atom or a substituted or unsubstituted alkyl group, represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted acylamino group, R ^1, R ² is not a 2-hydroxyphenylmethyl group, R ³ is a hydrogen atom or a substituted or unsubstituted alkyl group, and R ⁴ is a substituent that can be substituted on a benzene ring.)

Preferably, the addition ratio (molar ratio) of the compound represented by the general formula (II) to the compound represented by the general formula (I) is 0.005 to 0.1. According to another aspect of the present invention, there is provided an image forming method, wherein the photothermographic material of the present invention is processed with a heat development time of 5 to 20 seconds.

[0008]

Embodiments of the present invention will be described below in detail. In this specification, “to” indicates a range including numerical values described before and after it as a minimum value and a maximum value, respectively. The organic silver salt that can be used in the present invention is relatively stable to light, but at 80 ° C. or less in the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent. It is a silver salt that forms a silver image when heated as described above. The organic silver salt can be any organic substance including a source capable of reducing silver ions. Such non-photosensitive organic silver salts are described in JP-A-10-628.
No. 99, paragraphs 0048 to 0049, EP-A-0803764A1, page 18, line 24 to page 19, line 37, EP-A-0 962 812 A1, JP-A-11-349951, 2000
-7683 and 2000-72711. Silver salts of organic acids, especially (C10-C10
Silver salts of long chain aliphatic carboxylic acids (30, preferably 15 to 28) are preferred. Preferred examples of the organic silver salt include silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate,
And silver palmitate, and mixtures thereof. In the present invention, among these organic silver salts, it is preferable to use an organic acid silver salt having a silver behenate content of 75 mol% or more.

The photothermographic material of the present invention contains a non-photosensitive organic silver salt. The shape of the organic silver salt that can be used in the present invention is not particularly limited, and may be any of a needle shape, a rod shape, a flat plate shape, and a scaly shape, preferably a needle shape and a scaly shape, and particularly preferably a scaly shape. . In the present specification, the scaly organic silver salt is defined as follows. The silver salt of an organic acid was observed with an electron microscope, and the shape of the silver salt of an organic acid was approximated to a rectangular parallelepiped. Then, calculation is performed using the shorter numerical values a and b, and x is obtained as follows. x = b / a x is obtained for about 200 particles in this manner,
Assuming that the average value x (average), x (average) ≧ 1.5
The one satisfying the above relationship is scaly. Preferably 30
≧ x (average) ≧ 1.5, more preferably 20 ≧ x (average) ≧ 2.0. By the way, the needle shape is 1 ≦ x (average) <
1.5.

In the scaly particles, a can be regarded as the thickness of tabular particles having a principal plane with b and c as sides. The average of a is preferably from 0.01 μm to 0.23 μm, more preferably from 0.1 μm to 0.20 μm. c / b
Is preferably 1 to 6, more preferably 1.05 to
4, more preferably 1.1 to 3, particularly preferably 1.
1-2. The particle size distribution of the organic silver salt is preferably monodispersed. The monodispersion is the standard deviation of the lengths of the minor axis and major axis divided by the minor axis and major axis, respectively, and is 100.
The fraction is preferably 100% or less, more preferably 80%
Or less, more preferably 50% or less. The shape of the organic silver salt can be measured 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, and the percentage (coefficient of variation) divided by the volume-weighted average diameter is preferably 100% or less. It is preferably at most 80%, more preferably at most 50%. As a measuring method, for example, an organic silver salt dispersed in a liquid is irradiated with laser light, and the particle size (volume weighted average diameter) obtained by obtaining an autocorrelation function with respect to a time change of fluctuation of the scattered light is obtained. be able to.

Known methods and the like can be applied to the production and dispersion method of the organic acid silver used in the present invention. For example, the above-mentioned JP-A-10-62899, European Patent Publication No. 0803763A1, and European Patent Publication No. 096
2812A1, JP-A-11-34991, JP-A-2000-7683, and 2000-72
No. 711, Japanese Patent Application No. 11-348228, Japanese Patent Application No. 11-348229, Japanese Patent Application No. 11-348230, Japanese Patent Application No. 11-203413, Japanese Patent Application No. 2000
-90093, 2000-195621, 2000-191226, 2000
Reference can be made to JP-A-213813, JP-A-2000-214155, JP-A-2000-191226 and the like.

In addition, when a photosensitive silver salt is present at the time of dispersing the organic silver salt, fog increases and the sensitivity is remarkably reduced. According to the present invention, the amount of the photosensitive silver salt in the aqueous dispersion to be dispersed is 0.1 mol% or less based on 1 mol of the organic acid silver salt in the liquid, and the photosensitive silver salt is positively added. Not something. In the present invention, it is possible to produce a photosensitive material by mixing the aqueous dispersion of the organic silver salt and the aqueous dispersion of the photosensitive silver salt, the mixing ratio of the organic silver salt and the photosensitive silver salt can be selected according to the purpose, The ratio of the photosensitive silver salt to the organic silver salt is preferably in the range of 1 to 30 mol%, and more preferably 3 to 2 mol%.
A range of 0 mol%, especially 5 to 15 mol% is preferred. Mixing two or more aqueous dispersions of organic silver salts with two or more aqueous dispersions of photosensitive silver salts during mixing is a method preferably used for controlling photographic characteristics. In the present invention, the organic silver salt can be used in a desired amount.
5 g / m ² is preferred, and more preferably 1-3 g / m ²
It is.

The photothermographic material of the present invention contains a reducing agent for silver ions. The reducing agent for silver ions (organic silver salts) can be any substance (preferably an organic substance) that reduces silver ions to metallic silver. Such reducing agents are described in paragraphs 0043 to 00 of JP-A-11-65021.
45, and from page 7, line 34 to page 18, line 12 of EP-A-0803764A1. As the reducing agent used in the present invention, a bisphenol reducing agent is preferable, and at least one kind of an o-linked polyphenol compound represented by the following general formula (I) is used.

[0014]

Embedded image

In the general formula (I), R ¹¹ and R ¹¹ ′
Each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. R ¹² and R ¹² ′ each independently represent a hydrogen atom or a substituent that can be substituted on a benzene ring. L is -S
— Or —CHR ¹³ —. R ¹³ represents a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. X ¹ and X ¹ ′ each independently represent a hydrogen atom or a group that can be substituted on a benzene ring.

The general formula (I) will be described in detail. R
¹¹ and R ¹¹ ′ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. The substituent on the alkyl group is not particularly limited, but is preferably an aryl group, a hydroxy group, an alkoxy group, an aryloxy group,
Examples thereof include an alkylthio group, an arylthio group, an acylamino group, a sulfonamide group, a sulfonyl group, a phosphoryl group, an acyl group, a carbamoyl group, an ester group, and a halogen atom. R ¹² and R ¹² ′ are each independently a hydrogen atom or a substituent that can be substituted on a benzene ring, and X ¹ and X ¹ ′ are each independently a hydrogen atom or a group that can be substituted on a benzene ring. Preferred examples of the group that can be substituted on a benzene ring include an alkyl group, an aryl group, a halogen atom, an alkoxy group, and an acylamino group.

L represents a —S— group or a —CHR ¹³ — group. R ¹³ represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and the alkyl group may have a substituent. R ¹³
Specific examples of the unsubstituted alkyl group are a methyl group, an ethyl group,
Examples include a propyl group, a butyl group, a heptyl group, an undecyl group, an isopropyl group, a 1-ethylpentyl group, and a 2,4,4-trimethylpentyl group. Examples of the substituent for the alkyl group can include, similar to substituent of R ^11, halogen atom, alkoxy group, alkylthio group, aryloxy group, arylthio group, an acylamino group, a sulfonamido group, a sulfonyl group, a phosphoryl group, an oxycarbonyl group, Examples include a carbamoyl group and a sulfamoyl group.

R ¹¹ and R ¹¹ ′ are preferably a secondary or tertiary alkyl group having 3 to 15 carbon atoms, specifically, isopropyl, isobutyl, tert-butyl, t-butyl,
ert-amyl group, tert-octyl group, cyclohexyl group,
Cyclopentyl group, 1-methylcyclohexyl group, 1-
And a methylcyclopropyl group. R ¹¹ and R ¹¹ ′ are more preferably tertiary alkyl groups having 4 to 12 carbon atoms, and among them, a tert-butyl group, a tert-amyl group,
A 1-methylcyclohexyl group is more preferred, and a tert-butyl group is most preferred. R ¹² and R ¹² ′ are preferably an alkyl group having 1 to 20 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, a tert-amyl group, a cyclohexyl Group, 1-methylcyclohexyl group, benzyl group, methoxymethyl group, methoxyethyl group and the like. More preferred are a methyl group, an ethyl group, a propyl group, an isopropyl group and a tert-butyl group.

X ¹ and X ¹ ′ are preferably a hydrogen atom,
It is a halogen atom or an alkyl group, more preferably a hydrogen atom. L is preferably a -CHR < ¹³ >-group. R ¹³ is preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, wherein the alkyl group is a methyl group, an ethyl group,
A propyl group, an isopropyl group and a 2,4,4-trimethylpentyl group are preferred. Particularly preferred as R ¹³ is a hydrogen atom, a methyl group, a propyl group or an isopropyl group. When R ¹³ is a hydrogen atom, R ¹² and R ¹² ′ are preferably an alkyl group having 2 to 5 carbon atoms, more preferably an ethyl group or a propyl group, and most preferably an ethyl group.

[0020] When R ¹³ is a primary or secondary alkyl group having 1 to 8 carbon atoms, R ¹² and R ^{1 2} 'is preferably a methyl group. As the primary or secondary alkyl group having 1 to 8 carbon atoms for R ^13, a methyl group, an ethyl group, a propyl group, and an isopropyl group are more preferable, and a methyl group, an ethyl group, and a propyl group are more preferable. R ¹¹ , R ¹¹ ′, R ¹² and R ¹² ′
Is a methyl group, R ¹³ is preferably a secondary alkyl group. In this case, the secondary alkyl group for R ¹³ is preferably an isopropyl group, an isobutyl group, or a 1-ethylpentyl group, and more preferably an isopropyl group. Hereinafter, specific examples of the compound represented by formula (I) used as a reducing agent in the present invention are shown, but the present invention is not limited thereto.

[0021]

Embedded image

[0022]

Embedded image

The addition amount of the compound represented by the general formula (I) in the present invention is preferably from 0.01~5.0g / m ^2, to be 0.1 to 3.0 g / m ² More preferably, the ratio is 5 to 1 mol of silver on the surface having the image forming layer.
Preferably, it is contained in an amount of from 50 to 50% by mole, more preferably from 10 to 40% by mole. The compound represented by the general formula (I) is preferably contained in an image forming layer. The compound represented by the general formula (I) may be contained in the coating solution by any method such as a solution form, an emulsified dispersion form, and a solid fine particle dispersion form, and may be contained in the photosensitive material. Well-known emulsification dispersion methods include oils such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and dissolution using an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically dispersing the emulsified dispersion. There is a method of manufacturing.

As a method for dispersing the solid fine particles, a powder of the compound represented by the general formula (I) is dissolved in a suitable solvent such as water in a ball mill, a colloid mill, a vibrating ball mill, a sand mill, a jet mill, a roller mill or a super mill. A method of dispersing by a sound wave to produce a solid dispersion may be used.
In this case, a protective colloid (for example, polyvinyl alcohol) and a surfactant (for example, an anionic surfactant such as sodium triisopropylnaphthalenesulfonate (a mixture of three isopropyl groups having different substitution positions)) may be used. Good. The aqueous dispersion can contain a preservative (eg, benzoisothiazolinone sodium salt).

Next, the general formula (II) will be described in detail. In the general formula (II), R ¹ represents a substituted or unsubstituted alkyl group. In the general formula (II), when R ² is a substituent other than a hydrogen atom, R ¹ represents an alkyl group. The alkyl group is preferably an alkyl group having 1 to 30 carbon atoms, and the alkyl group may be unsubstituted or have a substituent. As the unsubstituted alkyl group, specifically, methyl, ethyl, butyl, octyl, isopropyl, tert-
Butyl, tert-octyl, tert-amyl, sec-butyl, cyclohexyl, 1-methyl-cyclohexyl group and the like are preferable, and a group three-dimensionally larger than the isopropyl group (for example, isopropyl group, isononyl group, tert-butyl group, t
ert-amyl group, tert-octyl group, cyclohexyl group,
1-methyl-cyclohexyl group, adamantyl group, etc.)
And a tertiary alkyl group such as tert-butyl, tert-octyl, or tert-amyl group is particularly preferable. When R ¹ has a substituent, examples of the substituent include a halogen atom, an aryl group, an alkoxy group, an amino group, an acyl group, an acylamino group, an alkylthio group, an arylthio group, a sulfonamide group, an acyloxy group, an oxycarbonyl group, and a carbamoyl group. , A sulfamoyl group,
Examples include a sulfonyl group and a phosphoryl group.

R ² represents a hydrogen atom, a substituted or unsubstituted alkyl group or a substituted or unsubstituted acylamino group. R
^The alkyl group represented by ² is preferably an alkyl group having 1 to 30 carbon atoms, and the acylamino group represented by R ² is preferably an acylamino group having 1 to 30 carbon atoms. The description of the alkyl group is the same as that of R ¹ . The acylamino group may be unsubstituted or may have a substituent, specifically, an acetylamino group,
Examples include an alkoxyacetylamino group and an aryloxyacetylamino group. R ² is preferably a hydrogen atom or an unsubstituted alkyl group having 1 to 24 carbon atoms, and specific examples include a methyl group, an isopropyl group, and a t-butyl group. R ¹ and R ² are never a 2-hydroxyphenylmethyl group.

R ³ represents a hydrogen atom or a substituted or unsubstituted alkyl group. The alkyl group represented by R ³ has 1 to 1 carbon atoms.
Preferably an alkyl group having 30, description of the alkyl group R ¹
Is the same as R ³ is preferably a hydrogen atom or an unsubstituted alkyl group having 1 to 24 carbon atoms, specifically, a methyl group, an isopropyl group, and a tert-butyl group. Preferably, one of R ² and R ³ is a hydrogen atom.

R ⁴ represents a group which can be substituted on a benzene ring,
For example, the same groups as those described by the general formula R ^{1 2} and R ¹² in compounds of (I) '. R ⁴ is preferably a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, an oxycarbonyl group having 2 to 30 carbon atoms, and having 1 to 24 carbon atoms.
Is more preferred. Examples of the substituent of the alkyl group include an aryl group, an amino group, an alkoxy group, an oxycarbonyl group, an acylamino group, an acyloxy group, an imide group, and a ureido group. preferable. The substituents of these alkyl groups may be further substituted with these substituents.

Alternatively, R ⁴ represents a substituent such that the compound of the general formula (II) becomes a compound of the general formula (III) described below. That is, a more preferred structure among the compounds of the general formula (II) is represented by the general formula (III).

[0030]

Embedded image

R ³¹ , R ³² , R ³³ and R ³⁴ are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. The substituent on the alkyl group is not particularly limited, but is preferably an aryl group, a hydroxy group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an acylamino group, a sulfonamide group, a sulfonyl group, a phosphoryl group. , An acyl group, a carbamoyl group, an ester group, a halogen atom and the like. R ³¹ , R ³² , R ³³
And R ³⁴ , a group sterically larger than the isopropyl group (eg, isopropyl group, isononyl group, te
At least one rt-butyl group, tert-amyl group, tert-octyl group, cyclohexyl group, 1-methyl-cyclohexyl group, adamantyl group, etc.) is preferably present, and more preferably two or more. Tertiary alkyl group is sterically larger than isopropyl group
Particularly preferred are tert-butyl, tert-octyl, tert-amyl and the like. L in the general formula (III) is the same as that described for L in the general formula (I). Hereinafter, the general formula (II) or the general formula (II) which can be used in the present invention.
Specific examples of the compound (I) are shown below, but it should not be construed that the invention is limited thereto.

[0032]

Embedded image

[0033]

Embedded image

[0034]

Embedded image

[0035]

Embedded image

[0036]

Embedded image

[0037]

Embedded image

[0038]

Embedded image

The compound represented by the general formula (II) or (III) can be added in the same manner as the method for adding the compound represented by the general formula (I). It may be contained in the coating solution by any method such as a form, an emulsified dispersion form, and a solid fine particle dispersion form, and may be contained in the photosensitive material.

The addition ratio (molar ratio) of the compound of general formula (II) (hindered phenol compound) (including the compound of general formula (III)) to the compound of general formula (I) (o-linked polyphenol) ) Is in the range of the compound of the general formula (II) or (III) / the compound of the general formula (I) (molar ratio) = 0.001 to 0.2, preferably in the range of 0.005 to 0.1. And more preferably in the range of 0.008 to 0.05.

The compound of the general formula (I) and the compound of the general formula (II) or (III) are preferably contained in an image-forming layer containing an organic silver salt. It may be contained in the non-image forming layer adjacent thereto,
Both may be contained in the non-image forming layer. When the image forming layer is composed of a plurality of layers, they may be contained in separate layers. In the photothermographic material of the present invention, a phenol derivative represented by the formula (A) described in Japanese Patent Application No. 11-73951 is preferably used as a development accelerator.

When the reducing agent in the present invention has an aromatic hydroxyl group (-OH), particularly in the case of the above-mentioned bisphenols, a non-reducing agent having a group capable of forming a hydrogen bond with these groups is used. It is preferable to use a compound having an acidic property. Examples of the group that forms a hydrogen bond with a hydroxyl group or an amino group include a phosphoryl group, a sulfoxide group, a sulfonyl group, a carbonyl group, an amide group, an ester group, a urethane group, a ureido group, a tertiary amino group, and a nitrogen-containing aromatic group. No. Among them, preferred are a phosphoryl group, a sulfoxide group, and an amide group (provided that they have no> NH group,
> N-Ra (Ra is a substituent other than H). ), A urethane group (provided that it has no> NH group and is blocked like> N-Ra (Ra is a substituent other than H)), a ureido group (provided that the> NH group is And a compound having> N—Ra (Ra is a substituent other than H). A hydrogen-bonding compound that can be particularly preferably used in the present invention is a compound represented by the following general formula (A).

[0043]

Embedded image

In the general formula (A), R ²¹ , R ²² and R ²³
Each independently represents an alkyl group, an aryl group, an alkoxy group,
Represents an aryloxy group, an amino group or a heterocyclic group,
These groups may be unsubstituted or have a substituent. When R ²¹ , R ²² and R ²³ have a substituent, examples of the substituent include a halogen atom, an alkyl group, an aryl group, an alkoxy group, an amino group, an acyl group, an acylamino group, an alkylthio group, an arylthio group, a sulfonamide group, An acyloxy group, an oxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group, a phosphoryl group, and the like are mentioned.A preferred substituent is an alkyl group or an aryl group, for example, a methyl group, an ethyl group, an isopropyl group, Group, tert-octyl group, phenyl group,
Examples thereof include a 4-alkoxyphenyl group and a 4-acyloxyphenyl group.

The alkyl group of R ²¹ , R ²² and R ²³ is preferably a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, which is a straight-chain, branched-chain, cyclic or combination thereof. Group, ethyl group, butyl group, octyl group,
Dodecyl group, isopropyl group, tert-butyl group, tert-amyl group, tert-octyl group, cyclohexyl group, 1-methylcyclohexyl group, benzyl group, phenethyl group, 2
-Phenoxypropyl group and the like. As the aryl group, a monocyclic or polycyclic substituted or unsubstituted aryl group having 6 to 20 carbon atoms is preferable, and specifically, a phenyl group,
Examples include a cresyl group, a xylyl group, a naphthyl group, a 4-tert-butylphenyl group, a 4-tert-octylphenyl group, a 4-anisidyl group, and a 3,5-dichlorophenyl group.

The alkoxy group is preferably a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, such as a straight-chain, branched-chain, cyclic or combination thereof, and specifically, methoxy, ethoxy, butoxy, octyl. Oxy group, 2-
Examples include an ethylhexyloxy group, a 3,5,5-trimethylhexyloxy group, a dodecyloxy group, a cyclohexyloxy group, a 4-methylcyclohexyloxy group, and a benzyloxy group. As the aryloxy group, an aryloxy group having 6 to 20 carbon atoms is preferable, and a phenoxy group, a cresyloxy group, an isopropylphenoxy group,
-Tert-butylphenoxy, naphthoxy, biphenyloxy and the like. The amino group has 0 carbon atoms.
~ 20 amino groups are preferable, and dimethylamino, diethylamino, dibutylamino, dioctylamino, N-methyl-N-hexylamino, dicyclohexylamino, diphenylamino, N-methyl-N-
And a phenylamino group.

The heterocyclic group is a 3- to 10-membered saturated or unsaturated heterocyclic group containing at least one of N, O and S atoms, which may be monocyclic or And a fused ring may be formed. Specific examples of the heterocycle in the heterocyclic group include, for example, pyrrolidine, piperidine, piperazine, morpholine, thiophene, furan, pyrrole, imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, indazole, purine , Thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline,
Cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzothiazole, benzselenazole, indolenine, tetrazaindene and the like.

As R ²¹ , R ²² and R ²³ , an alkyl group,
Aryl, alkoxy and aryloxy groups are preferred. From the viewpoint of the effects of the present invention, at least one or more of R ²¹ , R ²² and R ²³ is preferably an alkyl group or an aryl group, and more preferably two or more are an alkyl group or an aryl group. In addition, it is preferable that R ²¹ , R ²² and R ²³ be the same group from the viewpoint that they can be obtained at low cost. Specific examples of the hydrogen bonding compound including the compound of the general formula (A) that can be used in the present invention are shown below, but the present invention is not limited thereto.

[0049]

Embedded image

[0050]

Embedded image

Specific examples of the hydrogen bonding compound are described in Japanese Patent Application Nos. 2000-192191 and 2000-19 in addition to those described above.
No. 4811. The compound of the general formula (A) can be contained in a coating solution in the form of a solution, emulsified dispersion, or solid-dispersed fine particle dispersion as in the case of the reducing agent, and used in a photosensitive material. The hydrogen bonding compound used in the present invention forms a hydrogen bonding complex with a compound having a phenolic hydroxyl group and an amino group in a solution state, and is combined with a reducing agent and a hydrogen bonding compound (preferably represented by the general formula (A) ) Can be isolated in a crystalline state as a complex. It is particularly preferable to use the crystal powder isolated in this way as a solid dispersion fine particle dispersion in order to obtain stable performance. Also,
A reducing agent and a hydrogen bonding compound (preferably, a compound represented by the general formula (A):
Is mixed with a powder, and using a suitable dispersant, a complex is formed at the time of dispersion by a sand grinder mill or the like. The hydrogen bonding compound (preferably, the compound of the general formula (A)) is added to the reducing agent by 1
It is preferably used in the range of 200 to 200 mol%, more preferably in the range of 10 to 150 mol%, and still more preferably in the range of 30 to 100 mol%.

The photothermographic material of the present invention comprises at least one photothermographic material.
Types of photosensitive silver halide. The photosensitive silver halide used in the present invention is not particularly limited as a halogen composition, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, and silver iodochlorobromide can be used. Among them, silver bromide and silver iodobromide are preferred. The distribution of the halogen composition in the grains may be uniform, the halogen composition may change stepwise, or may change continuously. Further, silver halide grains having a core / shell structure can be preferably used. Preferred as the structure is a 2- to 5-fold structure, more preferably 2 to 4
Double core / shell particles can be used. A technique for localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.

Methods for forming photosensitive silver halide are well known in the art and are described, for example, in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. Specifically, a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to gelatin or another polymer solution,
Thereafter, a method of mixing with an organic silver salt is used. Further, paragraphs 0217 to 02 of JP-A-11-119374 are used.
24, the methods described in Japanese Patent Application Nos. 11-98708 and 2000-42336 are also preferable.

The grain size of the photosensitive silver halide is preferably small for the purpose of suppressing white turbidity after image formation, specifically, 0.20 μm or less, more preferably 0.01 μm to 0.15 μm, and furthermore, Preferably 0.02
μm to 0.12 μm is preferred. The grain size as used herein refers to a diameter when converted into a circular image having the same area as the projected area of a silver halide grain (projected area of a main plane in the case of a tabular grain). Examples of the shape of silver halide grains include cubic, octahedral, tabular grains, spherical grains, rod-like grains, potato-like grains, and the like, and cubic grains are particularly preferred in the invention. Grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grains is not particularly limited. However, the spectral sensitization efficiency when the spectral sensitizing dye is adsorbed is high. preferable. The ratio is preferably at least 50%, more preferably at least 65%, even more preferably at least 80%. The ratio of the Miller index {100} plane was determined by T. Tani; J. Imaging Sci., 29, 165 (1985) using the adsorption dependence of {111} plane and {100} plane in the adsorption of sensitizing dye. It can be determined by the method described.

In the present invention, silver halide grains having a hexacyano metal complex present on the outermost surface of the grains are preferred. Hexacyano metal complexes include [Fe (CN) ₆ ] ^4- , [Fe (CN) ₆ ] ^3- ,
[Ru (CN) ₆ ] ^4- , [Os (CN) ₆ ] ^4- , [Co (CN) ₆ ] ^3- , [Rh (C
N) ₆ ] ^3- , [Ir (CN) ₆ ] ^3- , [Cr (CN) ₆ ] ^3- , [Re (CN) ₆ ] ^{3-, and the} like. In the present invention, a hexacyano Fe complex is preferred. Since the hexacyano metal complex exists in the form of ions in an aqueous solution, its counter cation is not important, but it is easily miscible with water and is compatible with the precipitation operation of silver halide emulsions, sodium ion, potassium ion, rubidium. It is preferable to use an alkali metal ion such as an ion, a cesium ion and a lithium ion, an ammonium ion, and an alkylammonium ion (for example, a tetramethylammonium ion, a tetraethylammonium ion, a tetrapropylammonium ion, and a tetra (n-butyl) ammonium ion).

The hexacyano metal complex can be prepared by mixing water with a suitable water-miscible organic solvent (eg, alcohols, ethers, glycols, ketones, esters, amides, etc.) or gelatin. And can be added as a mixture. The amount of hexacyano metal complex added is per mole of silver.
The amount is preferably from 1 × 10 ⁻⁵ mol to 1 × 10 ⁻² mol, more preferably from 1 × 10 ⁻⁴ mol to 1 × 10 ⁻³ mol. In order for the hexacyano metal complex to be present on the outermost surface of the silver halide grains, the addition of the hexacyano metal complex to the silver nitrate aqueous solution used for grain formation is completed, and then the sulfur sensitization, selenium sensitization, and chalcogen sensitization of tellurium sensitization are completed. It is added directly before the completion of the preparation step before the chemical sensitization step for performing noble metal sensitization such as sensitization or gold sensitization, during the washing step, during the dispersion step, or before the chemical sensitization step. In order not to grow the silver halide fine grains, it is preferable to add the hexacyano metal complex immediately after the grain formation, and it is preferable to add the hexacyano metal complex before the completion of the charging step.

Incidentally, the addition of the hexacyano metal complex may be started after 96% by mass of the total amount of silver nitrate added for grain formation is added, or started after 98% by mass is added. More preferably, it is particularly preferable after adding 99% by mass. When these hexacyano metal complexes are added after the addition of the aqueous silver nitrate solution immediately before the completion of grain formation, they can be adsorbed on the outermost surface of silver halide grains, and most of them form hardly soluble salts with silver ions on the grain surface. I do. Since the hexacyanoiron (II) silver salt is a salt which is harder to dissolve than AgI, re-dissolution by fine particles can be prevented, and silver halide fine particles having a small particle size can be produced. .

The photosensitive silver halide grains used in the present invention may be any of groups 8 to 1 of the periodic table (showing groups 1 to 18).
It may contain a Group 0 metal or metal complex. Rhodium, ruthenium, and iridium are preferably the metals of Groups 8 to 10 of the periodic table or the central metal of the metal complex. One kind of these metal complexes may be used, or two or more kinds of complexes of the same metal and different metals may be used in combination. The preferred content is from 1 × 10 ⁻⁹ mol to 1 × per mol of silver.
A range of 10 ^-3 mole is preferred. These heavy metals and metal complexes and their addition methods are described in JP-A-7-22544.
9, JP-A-11-65021, paragraph number 00
18-0024 and JP-A-11-119374, paragraphs 0227 to 0240.

Further, metal atoms (for example, [Fe (C
N) ₆ ] ^4- ), desalting and chemical sensitization of silver halide emulsions are described in paragraph No. 00 of JP-A-11-84574.
46-0050, Paragraph Nos. 0025-0031 of JP-A-11-65021, and Paragraph Nos. 0242-0250 of JP-A-11-119374. Various gelatins can be used as the gelatin contained in the photosensitive silver halide emulsion used in the present invention.
In order to maintain a good dispersion state of the photosensitive silver halide emulsion in the organic silver salt-containing coating solution, the molecular weight is 500 to 60,000.
It is preferred to use low molecular weight gelatin of the above. These low molecular weight gelatins may be used at the time of particle formation or at the time of dispersion after desalting, but are preferably used at the time of dispersion after desalting.

The sensitizing dye applicable to the present invention is a sensitizing dye capable of spectrally sensitizing silver halide grains in a desired wavelength region when adsorbed on silver halide grains, and has a spectral sensitivity suitable for the spectral characteristics of an exposure light source. The sensitizing dye to be used can be advantageously selected. The sensitizing dye and the method of addition are described in
Paragraph Nos. 0103 to 0109 of 1-65021,
JP-A-10-186572, compounds represented by the general formula (II), JP-A-11-119374, dyes represented by the general formula (I) and paragraph No. 0106, U.S. Pat. No. 5,510,236 Description, No. 3,871,88
The dye described in Example 5 of JP-A-7-79, JP-A-2-961
No. 31 and JP-A-59-48753, and the like.
No. 3764A1, page 19, line 38 to page 20, page 3
5 lines, Japanese Patent Application No. 2000-86865, Japanese Patent Application 200
0-102560, Japanese Patent Application No. 2000-20539
No. 9 and the like. These sensitizing dyes may be used alone or in combination of two or more. In the present invention, the time when the sensitizing dye is added to the silver halide emulsion is preferably after the desalting step and before coating, and more preferably after desalting and before the start of chemical ripening. The addition amount of the sensitizing dye in the present invention can be a desired amount in accordance with the sensitivity and the performance of fogging, 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 EP-A-587,338,
U.S. Pat. Nos. 3,877,943 and 4,872.
Compounds described in JP-A-3,184, JP-A-5-341432, JP-A-11-109547 and JP-A-10-111543 are exemplified.

The photosensitive silver halide grains in the present invention are preferably chemically sensitized by a sulfur sensitization method, a selenium sensitization method, or a tellurium sensitization method. Known compounds preferably used in the sulfur sensitization method, the selenium sensitization method, and the tellurium sensitization method include, for example, JP-A-7-12876.
Compounds described in JP-A No. 8 (1996) and the like can be used.
Particularly in the present invention, tellurium sensitization is preferable.
Compounds described in paragraph No. 0030 of 1-65021 and compounds represented by formulas (II), (III) and (IV) in JP-A-5-313284 are more preferable.

In the present invention, chemical sensitization can be performed at any time after grain formation and before coating, and after desalting, (1) before spectral sensitization, (2) simultaneously with spectral sensitization, 3) After spectral sensitization, (4) immediately before coating, etc. In particular, it is preferably performed after spectral sensitization. Sulfur used in the present invention, the amount of the selenium or tellurium sensitizer, silver halide grains to be used, but the chemical ripening condition and the like and, per 1 mol of silver halide 10 ^-8 to 10 ^-2 mol, preferably 10 ^-7 ~
About 10 ^-3 mol is used. The conditions of the chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, p
Ag is about 6 to 11, and temperature is about 40 to 95 ° C. 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.

The light-sensitive silver halide emulsion in the light-sensitive material used in the present invention may be of one kind or two or more kinds (for example, those having different average grain sizes, different halogen compositions, different crystal habits). And those having different conditions of chemical sensitization). The gradation can be adjusted by using a plurality of photosensitive silver halides having different sensitivities.
Japanese Patent Application Laid-Open No. 57-119341 discloses a technique related to these.
JP-A-53-106125 and JP-A-47-392.
No. 9, No. 48-55730, No. 46-518
No. 7, No. 50-73627, No. 57-150
No. 841 and the like. The difference in sensitivity is preferably 0.2 logE or more for each emulsion.

The addition amount of the photosensitive silver halide is 0.03 to 0.6 g in terms of the amount of silver applied per m ² of the light-sensitive material.
/ M ² , preferably 0.07 to 0.4 g / m ²
More preferably, 0.05 to 0.3 g / m
It is most preferably ² , and the photosensitive silver halide is preferably 0.01 mol to 0.5 mol, more preferably 0.02 mol to 0.3 mol, per 1 mol of the organic silver salt.
Regarding the mixing method and the mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the prepared silver halide particles and organic silver salt were mixed with a high-speed stirrer, a ball mill, a sand mill, a colloid mill, a vibration mill, and a homogenizer. And the like, or a method of preparing an organic silver salt by mixing photosensitive silver halide prepared at any timing during the preparation of the organic silver salt. There is no particular limitation as long as it appears in. 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.

The preferred time for adding the silver halide to the image forming layer coating solution used in the present invention is from 180 minutes to immediately before coating, preferably from 60 minutes to 10 seconds before coating.
The mixing method and mixing conditions are not particularly limited as long as the effects of the present invention are sufficiently exhibited. As a specific mixing method, a method of mixing in a tank in which the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is a desired time, N. Harnby, MFEdwards, AWNienow
Written by Koji Takahashi, “Liquid Mixing Technology” (Nikkan Kogyo Shimbun, 1
989), using a static mixer or the like described in Chapter 8 and the like.

The binder for the organic silver salt-containing layer in the present invention may be any polymer, and suitable binders are transparent or translucent, generally colorless, and include natural resins and polymers and copolymers, and synthetic resins and polymers and copolymers. And other film-forming media such as gelatins, rubbers, poly (vinyl alcohol) s, hydroxyethyl celluloses, cellulose acetates, cellulose acetate butyrates, poly (vinyl pyrrolidone) s, casein, starch, poly ( Acrylic acid)
, Poly (methyl methacrylic acid) s, poly (vinyl chloride) s, poly (methacrylic acid) s, styrene-maleic anhydride copolymers, styrene-acrylonitrile copolymers, styrene-butadiene copolymers, Poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters),
Poly (urethane), phenoxy resin, poly (vinylidene chloride), poly (epoxide), poly (carbonate), poly (vinyl acetate), poly (olefin)
, Cellulose esters and poly (amides).
The binder may be coated from water or an organic solvent or an emulsion.

In the present invention, the glass transition temperature of the binder in the layer containing the organic silver salt is preferably from 10 ° C. to 80 ° C. (hereinafter sometimes referred to as a high Tg binder), and preferably from 20 ° C. to 70 ° C. More preferably, 23 ° C.
More preferably, it is -65 ° C. In this specification, Tg was calculated by the following equation. 1 / Tg = Σ (Xi / Tgi) Here, it is assumed that the polymer is obtained by copolymerizing n monomer components from i = 1 to n. Xi is the mass fraction of the ith monomer (ΣXi = 1), and Tgi is the glass transition temperature (absolute temperature) of the homopolymer of the ith monomer. Where Σ is i =
Take the sum from 1 to n. The homopolymer glass transition temperature value (Tgi) of each monomer is described in the Polymer Handbook (3rd Ed).
ition) (by J. Brandrup, EHImmergut (Wiley-Interscien
ce, 1989)).

The polymer serving as a binder may be used alone or in combination of two or more as necessary.
Further, those having a glass transition temperature of 20 ° C. or higher and those having a glass transition temperature of less than 20 ° C. may be used in combination.
When two or more polymers having different Tg are blended and used, the weight average Tg is preferably in the above range.

In the present invention, when the organic silver salt-containing layer is formed by coating using a coating solution in which 30% by mass or more of the solvent is water and drying, the binder of the organic silver salt-containing layer is further added. When it is soluble or dispersible in an aqueous solvent (aqueous solvent), the equilibrium water content at 25 ° C. and 60% relative humidity is particularly 2%.
The performance is improved when it is composed of a polymer latex of not more than mass%. The most preferred form has an ionic conductivity of 2.
It was prepared to be 5 mS / cm or less,
As such a preparation method, a method of purifying using a separation functional membrane after polymer synthesis may be mentioned. The aqueous solvent in which the polymer is soluble or dispersible as referred to herein is water or a mixture of water and 70% by mass or less of a water-miscible organic solvent. As the water-miscible organic solvent, for example,
Examples thereof include alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol; cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; ethyl acetate; and dimethylformamide.
Note that the term “aqueous solvent” is used herein even in a system in which the polymer is not thermodynamically dissolved but exists in a so-called dispersed state.

The “equilibrium moisture content at 25 ° C. and 60% relative humidity” is defined as the mass W1 of the polymer which is in humidity control equilibrium in an atmosphere of 25 ° C. and 60% relative humidity, and the mass of the polymer which is completely dried at 25 ° C. It can be expressed as follows using W0. Equilibrium water content at 25 ° C. and 60% relative humidity = ｛(W1-
W0) / W0｝ × 100 (% by mass) For the definition and measurement method of the water content, for example, Polymer Engineering Course 14, Polymer Material Testing Method (Polymer Society, edited by Jinjinshokan) can be referred to. . The binder polymer used in the present invention preferably has an equilibrium water content at 25 ° C. and a relative humidity of 60% of 2% by mass or less, more preferably 0.1% by mass or less.
01 mass% to 1.5 mass%, more preferably 0.02 mass%
% By mass to 1% by mass is desirable.

In the present invention, a polymer dispersible in an aqueous solvent is particularly preferred. Examples of the dispersion state include a latex in which fine particles of a water-insoluble hydrophobic polymer are dispersed, and a dispersion state in which polymer molecules are dispersed in a molecular state or in the form of micelles. The average particle size of the dispersed particles is 1 to 50000 nm, more preferably 5 to 50000 nm.
A range of about 1000 nm is preferable. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.

In the present invention, preferred embodiments of the polymer dispersible in an aqueous solvent include acrylic polymers, poly (esters), rubbers (for example, SBR resin), poly (urethane) s, poly (vinyl chloride) s, Hydrophobic polymers such as poly (vinyl acetate) s, poly (vinylidene chloride) s and poly (olefins) can be preferably used. These polymers may be a linear polymer, a branched polymer, a crosslinked polymer, a so-called homopolymer obtained by polymerizing a single monomer, or a copolymer obtained by polymerizing two or more types of monomers. In the case of a copolymer, it may be a random copolymer or a block copolymer. These polymers have a number average molecular weight of 5,000 to 1,000,000, preferably 10,000 to 200,000. If the molecular weight is too small, the mechanical strength of the emulsion layer is insufficient, and if it is too large, the film-forming properties are poor, which is not preferable.

Specific examples of preferable polymer latex include the following. In the following, the raw material monomers are used, and the numerical value in parentheses is% by mass, and the molecular weight is the number average molecular weight. When a polyfunctional monomer is used, the concept of molecular weight cannot be applied because a crosslinked structure is formed. Tg represents a glass transition temperature.

Latex of P-1; -MMA (70) -EA (27) -MAA (3)-(molecular weight 37000) P-2; -MMA (70) -2EHA (20) -St (5) -AA (5) -Latex (molecular weight 40000) P-3; -St (50) -Bu (47) -MAA (3) -Latex (crosslinkable) P-4; -St (68) -Bu (29) -AA (3)-latex (crosslinkable) P-5; -St (71) -Bu (26) -AA (3)-latex (crosslinkable, Tg24
℃) P-6; -St (70) -Bu (27) -IA (3)-latex (crosslinkable) P-7; -St (75) -Bu (24) -AA (1)-latex (Crosslinkability) P-8; -St (60) -Bu (35) -DVB (3) -MAA (2) -Latex (Crosslinkability) P-9; -St (70) -Bu (25)- Latex of DVB (2) -AA (3)-(crosslinkability) P-10; Latex of -VC (50) -MMA (20) -EA (20) -AN (5) -AA (5)-(molecular weight 80000) P-11; -VDC (85) -MMA (5) -EA (5) -MAA (5)-latex (molecular weight 67000) P-12; -Et (90) -MAA (10)-latex (Molecular weight 12000) Latex of P-13; -St (70) -2EHA (27) -AA (3) (molecular weight 130
000) P-14; -MMA (63) -EA (35) -AA (2) latex (molecular weight 3300
0) Latex of P-15; -St (70.5) -Bu (26.5) -AA (3)-
Tg23 ° C) P-16; -St (69.5) -Bu (27.5) -AA (3)-latex (crosslinkable,
(Tg20.5 ° C)

The abbreviations of the above structures represent the following monomers.
MMA; methyl methacrylate, EA; ethyl acrylate, MAA; methacrylic acid, 2EHA; 2-ethylhexyl acrylate, St; styrene, Bu; butadiene, AA; acrylic acid, DVB;
C; vinyl chloride, AN; acrylonitrile, VDC; vinylidene chloride, Et; ethylene, IA; itaconic acid.

The polymer latex described above is also commercially available, and the following polymers can be used. Examples of acrylic polymers include Sebian A-4635,471
8,4601 (all manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 8
Examples of poly (esters) such as 14, 821, 820, 857 (all manufactured by Nippon Zeon Co., Ltd.) include FINETEX ES650, 611, 67
5, 850 (all manufactured by Dainippon Ink and Chemicals, Inc.), WD-size, WMS
(Manufactured by Eastman Chemical), poly (urethane)
Examples of rubbers include HYDRAN AP10, 20, 30, 40 (all manufactured by Dainippon Ink and Chemicals, Inc.), and examples of rubbers include LACSTAR
7310K, 3307B, 4700H, 7132C (Dai Nippon Ink Chemicals
Nipol Lx416, 410, 438C, 2507 (Nippon Zeon Co., Ltd.)
Examples of poly (vinyl chloride) s such as G35
1. Examples of poly (vinylidene chloride) s such as G576 (all manufactured by Nippon Zeon Co., Ltd.) include L502 and L513 (all manufactured by Asahi Kasei Corporation)
Examples of poly (olefins) include Chemipearl S120 and SA100 (all manufactured by Mitsui Petrochemical Co., Ltd.). These polymer latexes may be used alone or as a blend of two or more as needed.

The polymer latex used in the present invention is particularly preferably a styrene-butadiene copolymer latex. The mass ratio of the styrene monomer unit to the butadiene monomer unit in the styrene-butadiene copolymer is preferably from 40:60 to 95: 5. The proportion of the copolymer of styrene monomer units and butadiene monomer units is 60 to 99% by mass.
It is preferred that The preferred molecular weight range is the same as described above. Styrene preferably used in the present invention-
As the butadiene copolymer latex, the aforementioned P-3
~ P-8, 14, 15, LACSTAR-3307B, 7132C, N which are commercial products
ipolLx416 and the like.

The organic silver salt-containing layer of the light-sensitive material of the present invention may optionally contain a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose and carboxymethylcellulose. The amount of these hydrophilic polymers to be added is 30% by mass or less of the total binder of the organic silver salt-containing layer, more preferably 20% by mass.
% By mass or less is preferred.

The organic silver salt-containing layer (that is, the image forming layer) in the photothermographic material of the present invention is preferably formed using a polymer latex. The amount of the binder in the organic silver salt-containing layer is such that the mass ratio of total binder / organic silver salt is 1
The range is preferably from / 10 to 10/1, more preferably from 1/5 to 4/1. Also,
Such an organic silver salt-containing layer is usually a photosensitive layer (emulsion layer) containing a photosensitive silver halide which is a photosensitive silver salt, and in such a case, the total binder / silver halide is used. The mass ratio is preferably in the range of 400 to 5, more preferably 200 to 10. The total binder amount of the image forming layer is 0.2
To 30 g / m ^2, more preferably in the range of 1 to 15 g / m ^2. A crosslinking agent for crosslinking and a surfactant for improving coating properties may be added to the image forming layer.

In the present invention, the solvent of the coating solution for the organic silver salt-containing layer of the light-sensitive material (here, for simplicity, the solvent and the dispersion medium are collectively referred to as a solvent) is preferably an aqueous solvent containing 30% by mass or more of water. . As a component other than water, any water-miscible organic solvent such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate may be used. The water content of the solvent in the coating liquid is preferably 50% by mass or more, more preferably 70% by mass or more. Examples of preferred solvent compositions include, in addition to water, water / methyl alcohol = 90/1
0, water / methyl alcohol = 70/30, water / methyl alcohol
/ Dimethylformamide = 80/15/5, water / methyl alcohol
/ Ethyl cellosolve = 85/10/5, water / methyl alcohol / isopropyl alcohol = 85/10/5, etc. (numerical values are mass%).

As antifoggants, stabilizers and stabilizer precursors which can be used in the present invention, JP-A-10-6
No. 2899, paragraph 0070, European Patent Publication No. 0
The compounds described in JP-A-803764A1, page 20, line 57 to page 21, line 7, and compounds described in JP-A-9-281637 and JP-A-9-329864 are exemplified. Further, the antifoggant preferably used in the present invention is an organic halide, and these are described in JP-A-11-65021, paragraphs 0111 to 0112.
And those disclosed in the patents described in US Pat. In particular, an organic halogen compound represented by the formula (P) in Japanese Patent Application No. 11-87297, an organic polyhalogen compound represented by the general formula (II) in JP-A-10-339934,
The organic polyhalogen compounds described in Japanese Patent Application No. 11-205330 are preferred.

Hereinafter, preferred organic polyhalogen compounds in the present invention will be specifically described. The preferred polyhalogen compound of the present invention is a compound represented by the following general formula (P). General formula (P): Q- (Y) _n -C (Z ¹ ) (Z ² ) X In the general formula (P), Q represents an alkyl group, an aryl group or a heterocyclic group, and Y is a divalent linkage. Represents a group, n represents 0 or 1, Z ¹ and Z ² represent a halogen atom, and X represents a hydrogen atom or an electron-withdrawing group.

In the general formula (P), Q preferably represents a phenyl group substituted by an electron-withdrawing group having a positive Hammett's substituent constant σp. Regarding Hammett's substituent constant, see Journal of Medicinal Chemistry, 1973, Vol.
16, No. 11, 1207-1216, etc. can be referred to. Examples of such an electron-withdrawing group include a halogen atom (fluorine atom (σp value: 0.06), a chlorine atom (σp value:
0.23), bromine atom (σp value: 0.23), iodine atom (σp value: 0.18), trihalomethyl group (tribromomethyl (σp value: 0.29), trichloromethyl (σp value: 0.33), trifluoromethyl (σp value:
0.54)), cyano group (σp value: 0.66), nitro group (σp value: 0.78), aliphatic / aryl or heterocyclic sulfonyl group (for example, methanesulfonyl (σp value
Value: 0.72)), aliphatic / aryl or heterocyclic acyl group (eg, acetyl (σp value: 0.50), benzoyl (σp value: 0.43)), alkynyl group (eg, C≡CH ( σp value: 0.23)), aliphatic / aryl or heterocyclic oxycarbonyl group (for example, methoxycarbonyl (σp value: 0.45), phenoxycarbonyl (σp value: 0.44)), carbamoyl group (σp value)
Value: 0.36), a sulfamoyl group (σp value: 0.5)
7), a sulfoxide group, a heterocyclic group, a phosphoryl group and the like. The σp value is preferably 0.2 to 2.0
And more preferably in the range of 0.4 to 1.0. Particularly preferred as the electron-withdrawing group are a carbamoyl group, an alkoxycarbonyl group, an alkylsulfonyl group, and an alkylphosphoryl group, among which a carbamoyl group is most preferred.

Z ¹ and Z ² represent a halogen atom, preferably a chlorine atom, a bromine atom and an iodine atom, more preferably a chlorine atom and a bromine atom, particularly preferably a bromine atom. X is preferably an electron-withdrawing group,
More preferred are a halogen atom, an aliphatic / aryl or heterocyclic sulfonyl group, an aliphatic / aryl or heterocyclic acyl group, an aliphatic / aryl or heterocyclic oxycarbonyl group, a carbamoyl group and a sulfamoyl group, and particularly preferred are a halogen atom It is. Among the halogen atoms, a chlorine atom, a bromine atom and an iodine atom are preferred, a chlorine atom and a bromine atom are more preferred, and a bromine atom is particularly preferred. Y is preferably -C (=
O) -, - SO- or -SO ₂ -; more preferably, -C (= O) -, - SO 2 - , and particularly preferably -SO ₂ - it is. n represents 0 or 1, and is preferably 1. Hereinafter, specific examples of the compound of the general formula (P) are shown.

[0086]

Embedded image

[0087]

Embedded image

The compound represented by formula (P) is preferably used in an amount of from 10 ^-4 to 1 mol, more preferably from 10 ^-3 to 1 mol, per 1 mol of the non-photosensitive silver salt in the image forming layer.
0.8 mols, more preferably 5 × 10 ^-3 ~
It is preferable to use it in the range of 0.5 mol. In the present invention, as a method for incorporating the antifoggant into the light-sensitive material, the method described in the above-mentioned method for containing the reducing agent can be mentioned, and the organic polyhalogen compound is preferably added in the form of a solid fine particle dispersion.

Other antifoggants include those described in
No. 65021, paragraph No. 0113, mercury (II)
Salts, benzoic acids of paragraph No. 0114 of the same publication, JP-A-20
JP-A-00-206642, salicylic acid derivative
000-221634, a formalin scavenger compound represented by formula (S), JP-A-11-35262
Japanese Patent Application Laid-Open No. Hei 6 (1994) No. 4 discloses a triazine compound according to claim 9
Compound represented by general formula (III) of JP-A-111791, 4
-Hydroxy-6-methyl-1,3,3a, 7-tetrazaindene and the like.

The photothermographic material of the present invention may contain an azolium salt for the purpose of preventing fog. Examples of the azolium salt include compounds represented by the general formula (XI) described in JP-A-59-193449, and JP-B-55-1258.
No. 1 and the compound represented by the general formula (II) described in JP-A-60-153039. The azolium salt may be added to any part of the photosensitive material, but it is preferably added to the layer having the photosensitive layer, and more preferably to the organic silver salt-containing layer. The azolium salt may be added at any time during the preparation of the coating solution, and when the azolium salt is added to the organic silver salt-containing layer, it may be at any stage from the preparation of the organic silver salt to the preparation of the coating solution, but after the preparation of the organic silver salt. To just before application. The azolium salt 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. In the present invention, any amount of the azolium salt may be added, but 1 ×
It is preferably from ^10-6 mol to 2 mol, and from 1 x ^10-3 mol to 0.
5 mol is more preferred.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained in order to control development by suppressing or accelerating development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. Paragraph No. 0 of JP-A-10-62899.
Nos. 067 to 0069, compounds represented by the general formula (I) in JP-A-10-186572, and paragraphs 0033 to 0052 as specific examples thereof, and European Patent Publication No. 08037.
No. 64A1, page 20, lines 36 to 56, Japanese Patent Application No. 11
-273670 and the like. Among them, mercapto-substituted heteroaromatic compounds are preferred.

In the photothermographic material of the present invention, it is preferable to add a toning agent.
No. 9, paragraphs 0054-0055, EP-A-0803764A1, page 21, pages 23-48.
Japanese Patent Application Laid-Open No. 2000-356317 and Japanese Patent Application No. 2000-356317.
And phthalazinones (phthalazinones, phthalazinone derivatives or metal salts; for example, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone and 2 ,
3-dihydro-1,4-phthalazinedione); phthalazinones and phthalic acids (eg, phthalic acid, 4-methylphthalic acid, 4
Phthalazines (phthalazine, phthalazine derivatives or metal salts; for example, 4- (1-naphthyl));-phthalazines (phthalazine, phthalazine derivatives or metal salts; for example, 4- (1-naphthyl))
Phthalazine, 6-isopropylphthalazine, 6-tert-butylfuratazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine); a combination of phthalazines and phthalic acids is preferred, Particularly, a combination of phthalazines and phthalic acids is preferable.

Plasticizers and lubricants which can be used in the photosensitive layer of the photothermographic material of the present invention are described in
Paragraph No. 0117 of 1-65021, the super-high contrast agent for forming a super-high contrast image and the addition method and the amount thereof are described in Paragraph 0118 of the same publication and Paragraph 0136 of JP-A-11-223898. 0193, Formula (H) of Japanese Patent Application No. 11-87297,
Compounds of formulas (1) to (3), formulas (A) and (B), Japanese Patent Application No. 11-916
Compounds of the general formulas (III) to (V) described in the specification of JP-A No. 52 (specific compounds: Chemical formulas 21 to 24), and the contrast enhancement accelerator are described in paragraph No. 0102 of JP-A-11-65021.
Paragraph No. 0194 of JP-A-11-223898
0195. In order to use formic acid or formate as a strong fogging substance, it is preferable to contain 5 mmol or less, more preferably 1 mmol or less, per mole of silver on the side having the image forming layer containing photosensitive silver halide.

When a super-high contrast agent is used in the photothermographic material of the present invention, it is preferable to use an acid formed by hydration of diphosphorus pentoxide or a salt thereof in combination. 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 Acid (salt)
And the like. Particularly preferred acids or salts thereof formed by hydration of diphosphorus pentoxide include,
Orthophosphoric acid (salt) and hexametaphosphoric acid (salt) can be mentioned. Specific salts include sodium orthophosphate, sodium dihydrogen orthophosphate, sodium hexametaphosphate, ammonium hexametaphosphate and the like. The amount of the acid or salt thereof formed by hydration of diphosphorus pentoxide (the amount of coating per m ^{2 of the} light-sensitive material) may be a desired amount according to the performance such as sensitivity and fog, but may be 0.1 to 50.
Preferably ^{0mg / m 2, 0.5~100mg / m} 2 is more preferable.

The photothermographic material of the present invention comprises an image forming layer
A surface protective layer can be provided to prevent adhesion of
You. The surface protective layer may be a single layer or a plurality of layers.
No. Regarding the surface protective layer, see JP-A-11-65021.
Publication paragraph Nos. 0119-0120, Japanese Patent Application 2000-17
No. 1936. Bypass of surface protection layer
Gelatin is preferred as the binder, but polyvinyl alcohol is preferred.
It is also preferable to use or use a combination of coal (PVA).
Examples of gelatin include inert gelatin (eg, Nitta Gelati)
750), phthalated gelatin (eg Nitta Gelatin 801)
Etc. can be used. As PVA, JP-A-20
No. 00-171936, paragraphs 0009 to 002
0, and fully saponified PVA-1
05, partially saponified PVA-205, PVA-33
5. MP-203 of modified polyvinyl alcohol (above,
Kuraray Co., Ltd.) and the like.
Polyvinyl alcohol coating amount of protective layer (per layer)
(Support 1m ^TwoPer) 0.3 to 4.0 g / m^Two
Is preferred, and 0.3 to 2.0 g / m^TwoIs more preferred.

In particular, when the photothermographic material of the present invention is used for printing in which dimensional change is a problem, it is preferable to use a polymer latex for the surface protective layer and the back layer.
For such polymer latexes, see "Synthetic Resin Emulsion (edited by Tadashi Okuda and Hiroshi Inagaki, published by Polymer Publishing Association (1978))", "Application of Synthetic Latex (Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, edited by Keiji Kasahara) Molecular publishing society (1993)), "Synthesis of synthetic latex (Souichi Muroi, published by Kobunshi Kankokai (1970))" and the like, and specifically, methyl methacrylate (33.5% by mass)
/ Ethyl acrylate (50% by weight) / methacrylic acid (16.5% by weight) copolymer latex, methyl methacrylate (4
7.5 mass%) / butadiene (47.5 mass%) / itaconic acid (5 mass
%) Copolymer latex, ethyl acrylate / methacrylic acid copolymer latex, methyl methacrylate (58.9% by mass) / 2-ethylhexyl acrylate (2
5.4% by mass) / styrene (8.6% by mass) / 2-hydroxyethyl methacrylate (5.1% by mass) / latex of acrylic acid (2.0% by mass) copolymer, methyl methacrylate (64.0% by mass) / styrene (9.0% by mass) / butyl Acrylate (20.0
Mass%) / 2-hydroxyethyl methacrylate (5.0 mass%
%) / Acrylic acid (2.0% by mass) copolymer latex. Further, as a binder for the surface protective layer, a combination of a polymer latex described in Japanese Patent Application No. 11-6872, a technique described in paragraph Nos.
The technology described in paragraphs 0027 to 0028 of -6872 specification and the technology described in paragraphs 0023 to 0041 of Japanese Patent Application No. 2000-19678 may be applied.
The ratio of the polymer latex in the surface protective layer is preferably from 10% by mass to 90% by mass of all the binders, particularly preferably 20% by mass.
~ 80 mass% is preferred. The total amount of the binder (including the water-soluble polymer and the latex polymer) of the surface protective layer (per layer) is 0.3 (per 1 m ^{2 of the} support).
-5.0 g / m < ² > is preferable, and 0.3-2.0 g / m < ² > is more preferable.

The temperature for preparing the coating solution for the image forming layer used in the present invention is preferably 30 ° C. to 65 ° C., more preferably 35 ° C. or higher.
Less than 60C, more preferred temperature is 35C to 55C. The temperature of the coating solution for the image forming layer immediately after the addition of the polymer latex is preferably maintained at 30 ° C to 65 ° C.

The image forming layer of the photothermographic material of the present invention comprises:
Consists of one or more layers on a support. When it is composed of one layer, it is composed of an organic silver salt, a photosensitive silver halide, a reducing agent and a binder, and if necessary, contains additional materials such as a toning agent, a coating auxiliary and other auxiliary agents as required. In the case of comprising two or more layers, the first image-forming layer (usually a layer adjacent to the support) contains an organic silver salt and a photosensitive silver halide, and the second image-forming layer or both layers contain some. Other components must be included. The construction of a multicolor photothermographic material may include a combination of these two layers for each color, and may include all components in a single layer as described in U.S. Patent No. 4,708,928. You may go out. In the case of a multi-dye multi-color photosensitive heat-developable photographic material,
Each emulsion layer is generally distinguished from each other by the use of a functional or non-functional barrier layer between each photosensitive layer, as described in U.S. Pat. No. 4,460,681. Being held.

In the photosensitive layer of the photothermographic material of the present invention, various dyes and pigments (for example, CIigm
entBlue 60, CI Pigment Blue 64, CI Pigment Blue
15: 6) can be used. These are described in International Publication WO98 / 36322, Japanese Patent Laid-Open No. 10-2684.
No. 65, No. 11-338098 and the like.

In the photothermographic material of the present invention, an antihalation layer can be provided on the side farther from the light source than the photosensitive layer. A photothermographic material generally has a non-photosensitive layer in addition to a photosensitive layer. The non-photosensitive layer may be arranged as follows: (1) a protective layer provided on the photosensitive layer (on the side farther than the support); (2) between a plurality of photosensitive layers or between the photosensitive layer and the protective layer (3) an undercoat layer provided between the photosensitive layer and the support, and (4) a back layer provided on the opposite side of the photosensitive layer. The filter layer is provided on the photosensitive material as the layer (1) or (2). The antihalation layer is provided on the photosensitive material as the layer (3) or (4).

The antihalation layer is disclosed in
JP-A-1-65021, paragraphs 0123 to 0124, JP-A-11-223898, JP-A-9-230531, JP-A-10-36695, and JP-A-10-10478.
No. 9, No. 11-231457, No. 11-35
No. 2625, 11-352626, and the like. The antihalation layer contains an antihalation dye having absorption at the exposure wavelength. When the exposure wavelength is in the infrared region, an infrared absorbing dye may be used, and in that case, a dye having no absorption in the visible region is preferable. When using a dye having absorption in the visible region to prevent halation, it is preferable that substantially no color of the dye remains after image formation, and a means for decoloring by the heat of heat development is used. It is particularly preferable to add a thermal decoloring dye and a base precursor to the non-photosensitive layer to function as an antihalation layer. These techniques are described in JP-A-11-231457 and the like.

The amount of the decolorizable dye is determined depending on the use of the dye. Generally, the optical density (absorbance) measured at the target wavelength is used in an amount exceeding 0.1. The optical density is preferably from 0.2 to 2. The amount of the dye used to obtain such an optical density is generally 0.001.
１1 g / m ² . When the dye is decolored in this way, the optical density after thermal development can be reduced to 0.1 or less. Two or more decolorizable dyes may be used in combination in a heat-decolorable recording material or a photothermographic material. Similarly, two or more base precursors may be used in combination.
In the thermal decoloring using such a decolorizing dye and a base precursor, when mixed with a base precursor as described in JP-A-11-352626, the melting point is 3 ° C (deg).
The substance to be lowered (for example, diphenyl sulfone, 4-
It is preferable to use chlorophenyl (phenyl) sulfone) in combination from the viewpoint of thermal discoloration.

In the present invention, a colorant having an absorption maximum at 300 to 450 nm can be added for the purpose of improving the silver tone and the aging of the image. Such colorants are described in JP-A-62-210458, JP-A-63-104046, JP-A-63-103235, and JP-A-63-2088.
No. 46, No. 63-306436, No. 63-3
No. 14,535, JP-A-01-61745, Japanese Patent Application No. 11-276751, and the like. Such a coloring agent is usually used in an amount of 0.1 mg / m ² to 1 mg / m ^2.
g / m ^{2, and} the backing layer provided on the opposite side of the photosensitive layer is preferable as the layer to be added. The photothermographic material of the present invention may be a so-called single-sided photosensitive material having at least one photosensitive layer containing a silver halide emulsion on one side of a support and a back layer on the other side. preferable.

In the present invention, it is preferable to add a matting agent for improving transportability.
JP-A-11-65021, paragraph numbers 0126-01
27. The matting agent is preferably 1 to 400 mg / m ² when expressed in a coating amount per m ² of the photosensitive material.
m ² , more preferably 5 to 300 mg / m ² . The matt degree of the emulsion surface may be any value as long as stardust failure does not occur, but the Beck smoothness is preferably 30 seconds to 2000 seconds, and particularly preferably 40 seconds to 1500 seconds. The Beck smoothness can be easily determined by Japanese Industrial Standards (JIS) P8119 “Smoothness test method of paper and paperboard with Beck tester” and TAPPI standard method T479. In the present invention, the back layer has a matte degree of Beck smoothness of 120.
It is preferably 0 seconds or less and 10 seconds or more, more preferably 800 seconds or less and 20 seconds or more, and still more preferably 500 seconds or less and 40 seconds or more. In the present invention, the matting agent is preferably contained in the layer functioning as the outermost surface layer or the outermost surface layer of the light-sensitive material, or a layer close to the outer surface, and is contained in a layer acting as a so-called protective layer. Is preferred.

The back layer applicable to the present invention is described in JP-A-11-65021, paragraphs 0128 to
0130. The photothermographic material of the present invention preferably has a film surface pH before thermal development treatment of 7.0 or less, more preferably 6.6 or less. The lower limit is not particularly limited, but is about 3. The most preferred pH range is between 4 and 6.2. 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. It is also preferable to use ammonia in combination with a non-volatile base such as sodium hydroxide, potassium hydroxide, and lithium hydroxide. The method of measuring the film surface pH is described in paragraph No. 0123 of Japanese Patent Application No. 11-87297.

A hardener may be used for each layer such as the photosensitive layer, the protective layer and the back layer of the photothermographic material of the present invention. Examples of hardeners include “THE THEORY OF THE PHOTO” by THJames.
GRAPHIC PROCESS FOURTH EDITION ”(Macmillan Publish
ing Co., Inc., 1977), pages 77 to 87, each of which includes chromium alum, 2,4-dichloro-6-hydroxy-s-triazine sodium salt, N, N-ethylenebis ( Vinyl sulfone acetamide), N, N-propylene bis (vinyl sulfone acetamide), polyvalent metal ions described on page 78 of the same book, US Pat. No. 4,281,060, JP-A-6-208193, and the like. Polyisocyanates, epoxy compounds such as U.S. Pat. No. 4,791,042, and vinylsulfone compounds such as JP-A-62-89048 are preferably used.

The hardener is added as a solution. The time of adding this solution to the coating solution for the protective layer is from 180 minutes to immediately before coating, preferably from 60 minutes to 10 seconds before coating. The mixing conditions are not particularly limited as long as the effects of the present invention are sufficiently exhibited. As a specific mixing method, a method of mixing in a tank such that the average residence time calculated from the addition flow rate and the amount of liquid sent to the coater is a desired time and N. Harnby, MFEdwards, AWNienow,
"Liquid mixing technology" translated by Koji Takahashi (Nikkan Kogyo Shimbun, 1989)
There is a method using a static mixer or the like described in Chapter 8, etc.

For the surfactant applicable to the present invention, paragraph No. 0132 of JP-A-11-65021, for the solvent, paragraph 0133 of the same publication, for the support, paragraph 0134 of the same publication, antistatic Or, for the conductive layer, paragraph No. 0135 of the same publication, and for a method of obtaining a color image, paragraph No. 0136 of the same publication,
The slip agents are described in paragraphs 0061 to 0064 of JP-A-11-84573 and paragraphs 0049 to 0062 of Japanese Patent Application No. 11-106881.

The transparent support is a polyester which has been subjected to a heat treatment at a temperature in the range of 130 to 185 ° C. in order to alleviate the internal strain remaining in the film at the time of biaxial stretching and to eliminate the heat shrinkage strain generated during the heat development processing. Particularly, polyethylene terephthalate is preferably used. In the case of a photothermographic material for medical use, the transparent support is made of a blue dye (for example,
The dye may be colored with the dye-1) described in Examples of JP-A-240877, or may be uncolored. As the support, water-soluble polyester disclosed in JP-A-11-84574,
Styrene-butadiene copolymer disclosed in JP-A-186565, JP-A-2000-39684 and Japanese Patent Application No. 11-1.
It is preferable to apply an undercoating technique such as a vinylidene chloride copolymer described in paragraphs [0063] to [0080] of JP-A-06881. For the antistatic layer or the undercoat, JP-A-56-143430 and JP-A-56-14343.
No. 1, No. 58-62646, No. 56-120
No. 519, paragraph Nos. 0040 to 0051 of JP-A-11-84573, U.S. Pat. No. 5,575,957, and paragraph No. 0 of JP-A-11-223898.
The techniques described in 078 to 0084 can be applied.

The photothermographic material is preferably of a monosheet type (a type capable of forming an image on the photothermographic material without using another sheet such as an image receiving material). The photothermographic material may further contain an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber or a coating aid.
Various additives are added to either the photosensitive layer or the non-photosensitive layer. About them, International Publication WO98 / 3
No. 6322, EP803764A1, JP-A-10-186567, and JP-A-10-18568 can be referred to.

The photothermographic material of the present invention may be applied by any method. Specifically, extrusion coating, slide coating, curtain coating, dip coating, knife coating,
Flow coating or US Pat. No. 2,681,2
Various coating operations are used, including extrusion coating using a hopper of the type described in U.S. Pat.
"LIQUID FI" by ephen F. Kistler and Peter M. Schweizer
LM COATING ”(CHAPMAN & HALL, 1997), pages 399 to 536, extrusion coating or slide coating is preferably used, and slide coating is particularly preferably used. Shape of slide coater used for slide coating Is described in FIG. 11b.1, p.
Two or more layers can be coated simultaneously by the methods described in U.S. Pat. No. 1,791 and GB 837,095.

The coating solution for the organic silver salt-containing layer in the present invention comprises:
Preferably, it is a so-called thixotropic fluid. For this technique, reference can be made to JP-A-11-52509. The organic silver salt-containing layer coating solution used in the present invention has a viscosity of 400 mPa at a shear rate of 0.1 s ^-1 .
S to 100,000 mPa · s, more preferably 500 mPa · s to 20,000 mPa · s. Also, at a shear rate of 1000 s ⁻¹ , 1 mPa
S to 200 mPa · s, more preferably 5 mPa · s to 80 mPa · s.

Techniques that can be used for the photothermographic material of the present invention include those described in EP803764A1,
No. 883022A1, International Publication WO98 / 3632
No. 2, JP-A-56-62648, 58-62
2644, JP-A-9-43766, and 9-
Nos. 281637 and 9-297367, 9
JP-A-304869, JP-A-9-31405, JP-A-9-329865, JP-A-10-10669,
JP-A-10-62899, JP-A-10-69023, JP-A-10-186568, and JP-A-10-90823
Gazettes, JP-A-10-171063, and JP-A-10-186
No. 565, No. 10-186567, No. 10-
Nos. 186569 to 10-186572, 10-197974, 10-197982, 10-199833, 10-19798
Nos. 5 to 10-197987 and 10-20
Nos. 7001, 10-207004, 10
-221807, 10-282601,
JP-A-10-288823, JP-A-10-288824, JP-A-10-307365, and JP-A-10-3120
No. 38, No. 10-339934, No. 11-7
No. 100, No. 11-15105, No. 11-2
Nos. 4200, 11-24201, 11-
Nos. 30832 and 11-84574 and 11
JP-65021, JP-A-11-109747, JP-A-11-125880, JP-A-11-129629, JP-A-11-133536 to JP-A-11-13353.
Nos. 9 and 11-133542 and 11-13
3543, 11-2223898, 11
-352627, 11-305377,
JP-A-11-305378, JP-A-11-305384, JP-A-11-305380, and JP-A-11-3164
No. 35, No. 11-327076, No. 11-3
Nos. 38096, 11-338098 and 1
No. 1-338099, No. 11-343420, No. 2000-187298, No. 2000-187298
No. 10229, No. 2000-47345, No. 2000-206642, No. 2000-9853
0, 2000-98531, 2000
JP-A-112059, JP-A-2000-112060, JP-A-2000-112104, and JP-A-2000-1
Nos. 12064 and 2000-171936.

The photothermographic material of the present invention may be developed by any method. Usually, the photothermographic material exposed imagewise is heated and developed. The preferred development temperature is 80 to 250 ° C, more preferably 10 to 250 ° C.
0-140 ° C. The development time is preferably 1 to 60 seconds, more preferably 3 to 30 seconds, and particularly preferably 5 to 20 seconds. Most preferably, it is 10 to 15 seconds.

As a method of thermal development, a plate heater method is preferable. The heat development method using the plate heater method is preferably a method described in JP-A-11-133572, and a visible image is obtained by bringing the heat-developable photosensitive material having a latent image formed thereon into contact with a heating means in a heat development section. A heat developing device, wherein the heating means comprises a plate heater,
A plurality of pressing rollers are provided to face each other along one surface of the plate heater, and heat development is performed by passing the photothermographic material between the pressing roller and the plate heater. This is a heat developing device. The plate heater is divided into 2 to 6 stages, and the tip is 1 to 10 ° C.
It is preferable to lower the temperature. Such a method is also described in JP-A-54-30032, which makes it possible to exclude water and an organic solvent contained in a photothermographic material from the system, The change in the shape of the support of the photothermographic material due to the heating of the material can also be suppressed.

The light-sensitive material of the present invention may be exposed by any method, but a laser beam is preferred as an exposure light source.
As laser light, gas laser (Ar ⁺ , He-Ne), YAG
Lasers, dye lasers, semiconductor lasers and the like are preferred. Further, a semiconductor laser and a second harmonic generation element can be used. Preferably, a gas or semiconductor laser emitting red to infrared light is used. Fuji Medical Dry Laser Imager FM-DPL can be cited as an example of a medical laser imager having an exposure unit and a heat development unit. Regarding FM-DPL, Fuji Med
ical Review No. 8, pages 39 to 55, and it goes without saying that those techniques are applied as a laser imager for the photothermographic material of the present invention. Also, DICO
It can also be applied as a photothermographic material for laser imagers in the "AD network" proposed by Fuji Medical System as a network system conforming to the M standard. The photothermographic material of the present invention forms a black-and-white image by a silver image, and is used for medical diagnosis, photothermographic material for industrial photography, photothermographic material for printing, CO
It is preferably used as a photothermographic material for M.

[0117]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Example 1 (Preparation of PET support) Terephthalic acid and ethylene glycol
PET with intrinsic viscosity IV = 0.66 (measured in phenol / tetrachloroethane = 6/4 (mass ratio) at 25 ° C) according to standard method
I got After pelletizing this, dried at 130 ° C for 4 hours,
After being melted at 300 ° C., it was extruded from a T-shaped die and quenched to prepare an unstretched film having a thickness of 175 μm after heat fixing. This was longitudinally stretched 3.3 times using rolls having different peripheral speeds, and then horizontally stretched 4.5 times using a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. After that, it was heat-set at 240 ° C. for 20 seconds and relaxed 4% in the horizontal direction at the same temperature. Then, after slitting the chuck part of the tenter, knurling is performed on both ends and 4k
The roll was taken up at g / cm ² to obtain a roll having a thickness of 175 μm.

(Surface Corona Treatment) Both surfaces of the support were treated at room temperature at a rate of 20 m / min using a pi solid state corona treatment machine (manufactured by Pillar Co., Ltd., 6 KVA model). From the current and voltage readings at this time, 0.375
It was found that the treatment was performed at kV · A · minute / m ² . At this time, the processing frequency was 9.6 kHz, and the gap clearance between the electrode and the dielectric roll was 1.6 mm.

(Preparation of Undercoat Support) (1) Preparation of Coating Solution for Undercoat Layer Formulation (for undercoat layer on photosensitive layer side) Takamatsu Oil Co., Ltd., Pesresin A-515GB (30% by mass solution) 234 g polyethylene glycol mono Nonyl phenyl ether (average ethylene oxide number = 8.5, 10% by mass solution) 21.5 g Polymer fine particles (manufactured by Soken Chemical Co., Ltd., MP-1000, average particle diameter 0.4 μm) 0.91 g distilled water 744 ml

Formulation (for back layer first layer) Styrene-butadiene copolymer latex (solid content: 40% by mass, styrene / butadiene mass ratio = 68/32) 158 g 2,4-dichloro-6-hydroxy-S-triazine Sodium salt (8% by mass aqueous solution) 20g Sodium laurylbenzenesulfonate (1% by mass aqueous solution) 10ml Distilled water 854ml

Formulation (for back surface side second layer) SnO ₂ / SbO (9/1 mass ratio, average particle size 0.038 μm, 17 mass% dispersion) 84 g gelatin (10 mass% aqueous solution) 89.2 g Shin-Etsu Chemical 8.6 g of polymer particles (manufactured by Soken Chemical Co., Ltd., MP-1000) 0.01 g Sodium dodecylbenzenesulfonate (1 mass% aqueous solution) 10 ml NaOH (1%) Mass%) 6 ml Proxel (manufactured by ICI) 1 ml distilled water 805 ml

(Preparation of undercoat support) The above thickness of 175 μm
After performing the above-described corona discharge treatment on both surfaces of the biaxially stretched polyethylene terephthalate support, the undercoating solution formulation was wet-coated on one surface (photosensitive layer surface) with a wire bar at a wet application amount of 6.6 ml / m ² (one surface). ) And dried at 180 ° C. for 5 minutes. Then, the undercoating coating solution was coated on the back surface (back surface) with a wire bar so that the wet coating amount was 5.7 ml / m ^2. And dried at 180 ° C for 5 minutes, then back side (back side)
The above-mentioned undercoating coating liquid formulation was coated with a wire bar so that the wet coating amount was 7.7 ml / m ² ,
For 6 minutes to prepare an undercoat support.

(Preparation of Back Surface Coating Liquid) (Preparation of Solid Precursor Dispersion (a) of Base Precursor) 64 g of base precursor compound 11, 28 g of diphenyl sulfone, and surfactant Demol N manufactured by Kao Corporation
10 g was mixed with 220 ml of distilled water, and the mixed solution was dispersed in beads using a sand mill (1/4 Gallon sand grinder mill, manufactured by Imex Co., Ltd.) to obtain a solid fine particle dispersion of a base precursor compound having an average particle diameter of 0.2 μm. (A) was obtained.

(Preparation of Dye Solid Fine Particle Dispersion) 9.6 g of cyanine dye compound 13 and 5.8 g of sodium p-dodecylbenzenesulfonate were mixed with 305 ml of distilled water. The beads were dispersed using an IMEX Co., Ltd.) to obtain a dispersion of solid dye fine particles having an average particle diameter of 0.2 μm.

(Preparation of coating solution for antihalation layer) 17 g of gelatin, 9.6 g of polyacrylamide, 70 g of solid fine particle dispersion (a) of the above base precursor, 56 g of the above solid fine particle dispersion of dye, and monodispersed polymethyl methacrylate fine particles (average) Particle size 8 μm, particle size standard deviation 0.
4) 1.5 g, benzoisothiazolinone 0.03 g, sodium polyethylenesulfonate 2.2 g, blue dye compound 14 0.2 g, yellow dye compound 15 3.9 g,
844 ml of water was mixed to prepare an antihalation layer coating solution.

(Preparation of back surface protective layer coating solution)
The mixture was kept at 0 ° C., gelatin 50 g, polystyrene sodium sulfonate 0.2 g, N, N-ethylenebis (vinylsulfone acetamide) 2.4 g, tert-octylphenoxyethoxyethaneethanesulfonate 1 g,
Benzoisothiazolinone 30 mg, fluorinated surfactant (F-1: N-perfluorooctylsulfonyl-N-
37 mg of propylalanine potassium salt) and 0.15 g of a fluorinated surfactant (F-2: polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [ethylene oxide average polymerization degree 15]) , Fluorinated surfactant (F-3) 6
4 mg, a fluorine-based surfactant (F-4) 32 mg, an acrylic acid / ethyl acrylate copolymer (copolymer mass ratio: 5
/ 95) 8.8 g, Aerosol OT (manufactured by American Cyanamid Co.) 0.6 g, liquid paraffin emulsion 1.8 g as liquid paraffin, and 950 ml of water were mixed to obtain a back surface protective layer coating solution.

<< Preparation of Silver Halide Emulsion 1 >> Distilled Water 14
To 21 ml, 3.1 ml of a 1% by mass potassium bromide solution was added, and 3.5 ml of 0.5 mol / L sulfuric acid was further added.
While stirring the solution to which 31.7 g of phthalated gelatin was added in a stainless steel reaction bottle, the solution temperature was maintained at 30 ° C., solution A prepared by adding distilled water to 22.22 g of silver nitrate to 95.4 ml and potassium bromide. 15.3 g and potassium iodide 0.
A solution B obtained by diluting 8 g with distilled water to a volume of 97.4 ml was added at a constant flow rate over 45 seconds. Then, 3.
10 ml of a 5% by mass aqueous solution of hydrogen peroxide was added, and 10.8 ml of a 10% by mass aqueous solution of benzimidazole was further added.
Was added. Further, a solution C diluted to 317.5 ml by adding distilled water to 51.86 g of silver nitrate and potassium bromide 4 were added.
4.2 g of potassium iodide and 2.2 g of potassium iodide in distilled water
The solution D diluted to 00 ml and the solution C
Solution D was added by a controlled double jet method while maintaining pAg at 8.1.
The total amount of potassium hexachloride (III) acid salt was added 10 minutes after starting to add the solution C and the solution D so as to be 1 × 10 ⁻⁴ mol per mol of silver. Five seconds after the completion of the addition of the solution C, an aqueous solution of potassium hexairon cyanide (II) was added in a total amount of 3 × 10 ^-4 mol per mol of silver.
The pH was adjusted to 3.8 using sulfuric acid at a concentration of 0.5 mol / L, stirring was stopped, and a precipitation / desalting / water washing step was performed. PH using 1 mol / L sodium hydroxide
The pH was adjusted to 5.9 to prepare a silver halide dispersion having a pAg of 8.0.

While stirring the above silver halide dispersion, 3
Maintained at 8 ° C, 0.34% by weight of 1,2-benzoiso
5 ml of a methanol solution of thiazolin-3-one was added,
After 40 minutes, the molar ratio of spectral sensitizing dye A to spectral sensitizing dye B was
A 1: 1 methanol solution was mixed with sensitizing dye A per mole of silver.
1.2 × 10 as a total of spectral sensitizing dye B^-3Mole,
One minute later, the temperature was raised to 47 ° C. 20 minutes after heating
1 mol of silver thiosulfonate in methanol solution
7.6 × 10^-FiveMole, and after another 5 minutes tell
Sensitizer C in methanol solution at 2.9 × per mole of silver
10^-FourMol was added and the mixture was aged for 91 minutes. N, N'-dihid
0.8% by weight of methanol of roxy-N ″ -diethylmelamine
1.3 ml of ethanol solution, and 4 minutes later, 5-methyl
2-mercaptobenzimidazole in methanol
4.8 × 10 per mole of silver in liquid ^-3Mol and 1-phenyl
Ru-2-heptyl-5-mercapto-1,3,4-tri
The azole is 5.4 × with respect to 1 mol of silver in a methanol solution.
10^-3A silver halide emulsion 1 was prepared by adding a mole.
The grains in the prepared silver halide emulsion have an average equivalent spherical diameter.
0.042 μm, iodine with a sphere equivalent diameter variation coefficient of 20%
The silver iodobromide particles contained 3.5 mol% uniformly. particle
The size, etc., is the average of 1000 particles using an electron microscope.
Asked from. The {100} face ratio of these particles is
It was determined to be 80% using the Munch method.

<< Preparation of Silver Halide Emulsion 2 >> In the preparation of Silver Halide Emulsion 1, the liquid temperature at the time of grain formation was 30 ° C.
The temperature was changed to 7 ° C., the solution B was changed to dilute 15.9 g of potassium bromide to a volume of 97.4 ml with distilled water, and the solution D was prepared by diluting 45.8 g of potassium bromide with a volume of 400 m in distilled water.
The silver halide emulsion 2 was prepared in the same manner except that the dilution was changed to 1 and the addition time of the solution C was changed to 30 minutes to remove potassium hexacyanoferrate (II). Precipitation / desalting / washing / dispersion was carried out in the same manner as in silver halide emulsion 1. Further, the addition amount of a methanol solution having a molar ratio of 1: 1 between the spectral sensitizing dye A and the spectral sensitizing dye B is 7.5 × 10 ^-4 mol as the total of the sensitizing dye A and the sensitizing dye B per mol of silver. , The amount of tellurium sensitizer C added was 1.1 × 10 ⁻⁴ mol per mol of silver,
1-phenyl-2-heptyl-5-mercapto-1,
3.3 × 10 3, 4-triazole per mole of silver
^-3 mol, spectral sensitization, chemical sensitization, 5-methyl-2-mercaptobenzimidazole, 1-phenyl-2-heptyl-5-mercapto-
By adding 1,3,4-triazole, a silver halide emulsion 2 was obtained. The emulsion grains of the silver halide emulsion 2 were pure silver bromide cubic grains having an average equivalent sphere diameter of 0.080 μm and a variation coefficient of the equivalent sphere diameter of 20%.

<< Preparation of Silver Halide Emulsion 3 >> In the preparation of silver halide emulsion 1, a liquid temperature of 30 ° C. during grain formation was adjusted to 2 ° C.
Except that the temperature was changed to 7.degree.
Was prepared. Further, precipitation / desalting / washing / dispersion / dispersion was carried out in the same manner as in silver halide emulsion 1. The molar ratio of the spectral sensitizing dye A to the spectral sensitizing dye B is 1: 1 as a solid dispersion (aqueous gelatin solution), and the amount added is 6 × 10 ⁻ as the total amount of the sensitizing dye A and the sensitizing dye B per mole of silver. Silver halide emulsion 3 was obtained in the same manner as in emulsion 1, except that the amount of ³ mol of tellurium sensitizer C was changed to 5.2 × 10 ^-4 mol per mol of silver.
The emulsion grains of the silver halide emulsion 3 had an average equivalent sphere diameter of 0.0
The particles were silver iodobromide particles containing 3.5 mol% of iodine having a uniform particle diameter of 34 μm and a coefficient of variation of 20%.

<< Preparation of Mixed Emulsion A for Coating Liquid >> A silver halide emulsion 1 was dissolved in 70% by mass, a silver halide emulsion 2 was dissolved in 15% by mass, and a silver halide emulsion 3 was dissolved in 15% by mass. 7 × 10 ⁻³ mol per mol of silver was added as a 1% by mass aqueous solution of the amide. Further, the content of silver halide per kg of the mixed emulsion for coating liquid was 38.2 as silver.
g.

<< Preparation of Fatty Acid Silver Dispersion >> 87.6 kg of behenic acid (product name: Edenor C22-85R) manufactured by Henkel, 423 L of distilled water, and 49.2 of a 5 mol / L NaOH aqueous solution 49.2.
L and tert-butanol (120 L) were mixed and reacted by stirring at 75 ° C. for 1 hour to obtain a sodium behenate solution. Separately, 206.2 L of an aqueous solution of 40.4 kg of silver nitrate
(PH 4.0) was prepared and kept at 10 ° C. 635
L of distilled water and 30 L of tert-butanol were kept at 30 ° C., and with sufficient stirring, the entire amount of the sodium behenate solution and the entire amount of the silver nitrate aqueous solution were respectively supplied at a constant flow rate of 93 minutes and 15 seconds. Added over 90 minutes.
At this time, only the aqueous solution of silver nitrate was added for 11 minutes after the start of the aqueous solution of silver nitrate, and then the addition of the sodium behenate solution was started.
For 4 minutes and 15 seconds, only the sodium behenate solution was added. At this time, the temperature inside the reaction vessel was set at 30 ° C., and the external temperature was controlled so that the liquid temperature became constant.
Further, the piping of the addition system of the sodium behenate solution was kept warm by circulating hot water outside the double tube, and the liquid temperature at the outlet of the addition nozzle tip was adjusted to 75 ° C. The piping of the silver nitrate aqueous solution addition system was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution and the addition position of the aqueous silver nitrate solution were arranged symmetrically with respect to the stirring axis, and were adjusted to a height such that they did not come into contact with the reaction solution.

After the completion of the addition of the sodium behenate solution, the mixture was allowed to stir at the same temperature for 20 minutes, and 35 minutes over 30 minutes.
C., and aging was performed for 210 minutes. Immediately after the ripening, the solid content was separated by centrifugal filtration, and the solid content was washed with water until the conductivity of the filtered water became 30 μS / cm. Thus, a fatty acid silver salt was obtained. The obtained solid content was stored as a wet cake without drying. When the morphology of the obtained silver behenate particles was evaluated by electron microscopic photographing, a = 0.14 μm, b = 0.4 μm, and c = 0.6 μm on average.
m, average aspect ratio 5.2, average sphere equivalent diameter 0.52μ
m, a scale-like crystal with a sphere equivalent diameter variation coefficient of 15%. (A, b, c are defined in the text)

For a wet cake having a dry solid content of 260 kg, polyvinyl alcohol (Kuraray Co., Ltd.
VA-217) 19.3 kg and water were added to make the total amount 1000 kg, and then slurried with a dissolver blade. Further, a pipeline mixer (PM, manufactured by Mizuho Industry Co., Ltd., PM
-10 type). Next, the pre-dispersed stock solution is dispersed in a dispersing machine (trade name: Microfluidizer M-610,
(Made by Microfluidics International Corporation, using Z-type interaction chamber)
Was adjusted to 1260 kg / cm ² , and the mixture was treated three times to obtain a silver behenate dispersion. For cooling operation, install a coiled heat exchanger before and after the interaction chamber, respectively.
The dispersion temperature was set at 18 ° C. by adjusting the temperature of the refrigerant.

<< Preparation of Dispersion of Reducing Agent-1 >> Reducing Agent-1
(1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,
10 kg of 5-trimethylhexane) and a 20% by mass aqueous solution of denatured polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.)
16 kg of water was added to 0 kg and mixed well to form a slurry. The slurry was fed by a diaphragm pump and was fed for 3 hours 30 in a horizontal bead mill (UVM-2 manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm.
After dispersion, benzoisothiazolinone sodium salt
0.2 g and water were added to adjust the concentration of the reducing agent to 25% by mass to obtain a reducing agent-1 dispersion. The reducing agent particles contained in the thus obtained reducing agent dispersion had a median diameter of 0.42 μm and a maximum particle diameter of 2.0 μm or less. The resulting reducing agent dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion of Reducing Agent-2 >> Reducing Agent-2
(2,2'-isobutylidene-bis- (4,6-dimethylphenol)) 10 kg and modified polyvinyl alcohol (Kuraray
To 10 kg of a 20% by weight aqueous solution of Poval MP203
16 kg of water was added and mixed well to form a slurry. This slurry is sent by a diaphragm pump and has an average diameter of 0.
After dispersing in a horizontal bead mill (UVM-2, manufactured by Imex Co., Ltd.) filled with 5 mm zirconia beads for 3 hours and 30 minutes, 0.2 g of benzoisothiazolinone sodium salt and water were added to reduce the concentration of the reducing agent to 25 mass. % To obtain a reducing agent-2 dispersion. The reducing agent particles contained in the thus obtained reducing agent dispersion had a median diameter of 0.38 μm and a maximum particle diameter of 2.0 μm or less. The resulting reducing agent dispersion has a pore size
Filtration was performed with a 10.0 μm polypropylene filter to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion of Reducing Agent Complex-3 >> Reducing Agent Complex-3 (2,2'-methylenebis- (4-ethyl-6-tert-butylphenol) and triphenylphosphine oxide:
1 complex) 10 kg, triphenylphosphine oxide 0.12
kg and modified polyvinyl alcohol (Kuraray Co., Ltd.)
16 kg of a 10% by weight aqueous solution of Povar MP203) and 7.2 kg of water
Was added and mixed well to form a slurry. The slurry was sent by a diaphragm pump and dispersed in a horizontal bead mill (UVM-2, manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 4 hours and 30 minutes, and then benzoisothiazolinone sodium salt 0.2 g and water were added to adjust the concentration of the reducing agent to 25% by mass to obtain a reducing agent complex-3 dispersion. The reducing agent complex particles contained in the thus obtained reducing agent complex dispersion had a median diameter of 0.46 μm and a maximum particle diameter of 1.6 μm or less. The obtained reducing agent complex 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 Reducing Agent-4 Dispersion >> Reducing Agent-4
(2,2'-methylenebis- (4-ethyl-6-tert-butylphenol)) 10kg and modified polyvinyl alcohol (Kuraray
To 20 kg of a 10% by weight aqueous solution of Poval MP203 manufactured by
6 kg of water was added and mixed well to form a slurry. This slurry is sent by a diaphragm pump and has an average diameter of 0.
After dispersing in a horizontal bead mill (UVM-2, manufactured by Imex Co., Ltd.) filled with 5 mm zirconia beads for 3 hours and 30 minutes, 0.2 g of benzoisothiazolinone sodium salt and water were added to reduce the concentration of the reducing agent to 25 mass. % To obtain a reducing agent-4 dispersion. The reducing agent particles contained in the thus obtained reducing agent dispersion had a median diameter of 0.40 μm and a maximum particle diameter of 1.5 μm or less. The resulting reducing agent dispersion has a pore size
Perform filtration with a 3.0 μm polypropylene filter,
Foreign matter such as dust was removed and stored.

<< Preparation of Dispersion of Reducing Agent-5 >> Reducing Agent-5
(2,2'-methylenebis- (4-methyl-6-tert-butylphenol)) 10 kg and modified polyvinyl alcohol (Kuraray
To 20 kg of a 10% by weight aqueous solution of Poval MP203 manufactured by
6 kg of water was added and mixed well to form a slurry. This slurry is sent by a diaphragm pump and has an average diameter of 0.
After dispersing in a horizontal bead mill (UVM-2, manufactured by Imex Co., Ltd.) filled with 5 mm zirconia beads for 3 hours and 30 minutes, 0.2 g of benzoisothiazolinone sodium salt and water were added to reduce the concentration of the reducing agent to 25 mass. % To obtain a reducing agent-5 dispersion. The reducing agent particles contained in the thus obtained reducing agent dispersion had a median diameter of 0.38 μm and a maximum particle diameter of 1.5 μm or less. The resulting reducing agent dispersion has a pore size
Perform filtration with a 3.0 μm polypropylene filter,
Foreign matter such as dust was removed and stored.

<< Preparation of Dispersion of the Compound of the General Formula (II) or (III) >> 75 g of the compound of the general formula (II) or (III) (types are shown in Table 1) and modified polyvinyl alcohol (Kuraray Co., Ltd.) Made, 10% by weight of Povar MP-203 aqueous solution 150g
Was added with 75 g of water and mixed well to form a slurry.
This slurry was bead-dispersed with 0.5 mm zirconia beads and a sand mill (1/4 Gallon sand grinder mill, manufactured by IMEX Co., Ltd.) at 1500 rpm for 10 hours to obtain a solid fine particle dispersion having a median diameter of 0.4 μm. Was.
The resulting dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion of Development Accelerator-1 >> 75 g of the development accelerator-1 and 150 g of a 10% by mass aqueous solution of a modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval MP-203) were prepared.
75 g of water was added and mixed well to form a slurry. This slurry is mixed with 0.5 mm zirconia beads and a sand mill (1/4
Gallon Sand Grinder Mill, IMEX Co., Ltd.
), The beads were dispersed at 1500 rpm for 10 hours,
A solid fine particle dispersion having a median diameter of 0.35 μm was obtained. The resulting dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion of Hydrogen Bonding Compound-2 >> 10 kg of hydrogen bonding compound-2 (tri (4-tert-butylphenyl) phosphine oxide) and modified polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.) 10 kg of water was added to 20 kg of a 10 mass% aqueous solution and mixed well to form a slurry. This slurry was sent by a diaphragm pump and dispersed in a horizontal bead mill (UVM-2, manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours and 30 minutes, and then benzoisothiazolinone sodium salt 0.2 g and water were added to adjust the concentration of the reducing agent to 22% by mass to obtain a hydrogen bonding compound-2 dispersion.
The reducing agent particles contained in the thus obtained reducing agent dispersion had a median diameter of 0.35 μm and a maximum particle diameter of 1.5 μm or less. The resulting hydrogen bonding compound dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion of Organic Polyhalogen Compound-1 >> 10 kg of organic polyhalogen compound-1 (2-tribromomethanesulfonylnaphthalene) and a 20% by mass aqueous solution of modified polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.) 10 kg, 0.4 kg of a 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate, 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 bead 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 0.2 g of benzoisothiazolinone sodium salt was added. Water was added to adjust the concentration of the organic polyhalogen compound to 23.5% by mass to obtain an organic polyhalogen compound-1 dispersion. The organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained have a median diameter of 0.36 μm and a maximum particle diameter of
It was 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion of Organic Polyhalogen Compound-2 >> 10 kg of organic polyhalogen compound-2 (tribromomethanesulfonylbenzene) and a 20% by mass aqueous solution of modified polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.)
kg, 0.4 kg of a 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate, and 14 kg of water were added and mixed well to form a slurry. This slurry was fed by a diaphragm pump and filled with zirconia beads having an average diameter of 0.5 mm in a horizontal bead mill (IMEX Co., Ltd.)
After dispersing for 5 hours with UVM-2), 0.2 g of benzoisothiazolinone sodium salt and water were added to adjust the concentration of the organic polyhalogen compound to 26% by mass. A dispersion was obtained. The organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained had a median diameter of 0.41 μm and a maximum particle diameter of 2.0 μm or less. The obtained organic polyhalogen compound dispersion was filtered through a polypropylene filter having a pore size of 10.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion of Organic Polyhalogen Compound-3 >> 10 kg of organic polyhalogen compound-3 (N-butyl-3-tribromomethanesulfonylbenzamide) and modified polyvinyl alcohol (Poval MP20, manufactured by Kuraray Co., Ltd.)
3) 20 kg of 10% by weight aqueous solution and 0.4 kg of 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate
And 8 kg of water were added and mixed well to form a slurry. This slurry was sent by a diaphragm pump and dispersed in a horizontal bead 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 0.2 g of benzoisothiazolinone sodium salt was added.
And water are added to make the concentration of the organic polyhalogen compound 25% by mass.
Was prepared. This dispersion was heated at 40 ° C. for 5 hours to obtain an organic polyhalogen compound-3 dispersion. The organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained have a median diameter of 0.36 μm and a maximum particle diameter of
It was 1.5 μm or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Phthalazine Compound-1 Solution >> 8k
g of modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd., MP
203) in 174.57 kg of water and then a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate.
3.15 kg and 14.28 kg of a 70% by mass aqueous solution of phthalazine compound-1 (6-isopropylphthalazine) were added to prepare a 5% by mass solution of phthalazine compound-1.

<< Preparation of Aqueous Solution of Mercapto Compound-1 >> Mercapto compound-1 (1- (3-sulfophenyl) -5
-Mercaptotetrazole sodium salt) 7 g to water 993 g
To give a 0.7% by mass aqueous solution.

<< Preparation of Pigment-1 Dispersion >> CI Pigment Bl
ue 60 (64 g) and Kao Corporation's Demol N (6.4 g) were mixed with water (250 g) and mixed well to form a slurry. Prepare 800 g of zirconia beads having an average diameter of 0.5 mm, put them in a vessel together with the slurry, and use a disperser (1 / 4G sand grinder mill:
The mixture was dispersed for 25 hours using IMEX Co., Ltd. to obtain a pigment-1 dispersion. The pigment particles contained in the pigment dispersion thus obtained had an average particle size of 0.21 μm.

<< Preparation of SBR latex liquid >> Tg = 23 ° C.
SBR latex was prepared as follows. Using ammonium persulfate as a polymerization initiator and an anionic surfactant as an emulsifier, 70.5 parts by mass of styrene, 26.5 parts by mass of butadiene and 3 parts by mass of acrylic acid were emulsion-polymerized, and then aged at 80 ° C. for 8 hours. went. Then 4
The mixture was cooled to 0 ° C., adjusted to pH 7.0 with aqueous ammonia, and further added with Sandet BL manufactured by Sanyo Chemical Co., Ltd. to a concentration of 0.22%. Next, a 5% aqueous sodium hydroxide solution was added to adjust the pH to 8.3, and further adjusted to pH 8.4 with aqueous ammonia. The Na ⁺ ion used at this time and N
The molar ratio of H ₄ ⁺ ions was 1: 2.3. Further, 0.15 ml of a 7% aqueous solution of sodium salt of benzoisothiazolinenone was added to 1 kg of this solution to prepare an SBR latex solution.

(SBR latex: -St (70.5) -Bu (26.5) -AA
(3) -Latex) Tg23 ° C Average particle size 0.1μm, Concentration 43% by mass, Equilibrium moisture content at 25 ° C 60% relative humidity 0.6% by mass, Ionic conductivity 4.2mS / cm (Ion conductivity is measured by Toa Denpa Industrial conductivity meter CM-30S
Use, latex stock solution (43% by mass measured at 25 ° C), pH
8.4 SBR latexes having different Tg were prepared by a similar method, while appropriately changing the ratio of styrene and butadiene.

<< Preparation of Emulsion Layer (Photosensitive Layer) Coating Solution-1 >>
1000 g of the fatty acid silver dispersion obtained above, 125 ml of water, reducing agent-1
113 g of a dispersion, 91 g of a reducing agent-2 dispersion, a dispersion of a compound of the formula (II) or (III) (types and amounts are shown in Table 1), 27 g of a pigment-1 dispersion, and an organic polyhalogen compound-1 dispersion Thing 8
2 g, organic polyhalogen compound-2 dispersion 40 g, phthalazine compound-1 solution 173 g, SBR latex (Tg: 20.5 ° C.) solution 10
82 g of a mercapto compound-1 aqueous solution was added in order, and 158 g of silver halide mixed emulsion A was added immediately before coating. The well-mixed emulsion layer coating solution was directly sent to a coating die and coated. The viscosity of the above emulsion layer coating solution is B
Measured at 40 ° C (No. 1 rotor, 60 rpm)
It was 0 [mPa · s]. The viscosity of the coating solution at 25 ° C. using an RFS Fluid Spectrometer manufactured by Rheometrics Far East Co., Ltd. was determined at a shear rate of 0.1, 1, 10, 10
1500, 220, 70, 40, 20 at 0, 1000 [1 / sec]
[mPa · s].

<< Preparation of Emulsion Layer (Photosensitive Layer) Coating Solution-2 >>
1000 g of the fatty acid silver dispersion obtained above, 104 ml of water, 30 g of pigment-1 dispersion, 21 g of organic polyhalogen compound-2 dispersion, 69 g of organic polyhalogen compound-3 dispersion, 173 g of phthalazine compound-1 solution, 173 g of SBR latex ( (Tg: 23 ° C.) 1082 g of a liquid, 258 g of a dispersion of a reducing agent complex-3, a dispersion of a compound of the formula (II) or (III) (types and amounts are shown in Table 1), and 9 g of a mercapto compound-1 solution are sequentially added. Immediately before coating, 110 g of the silver halide mixed emulsion A was added, and the well-mixed emulsion layer coating solution was directly sent to a coating die for coating.

<< Preparation of Emulsion Layer (Photosensitive Layer) Coating Solution-3 >>
1000 g of the fatty acid silver dispersion obtained above, 95 ml of water, reducing agent-4
Dispersion 73, 68 g of Reducing Agent-5 Dispersion, General Formula (II) or
(III) Compound dispersion (type and amount are shown in Table 1), Development accelerator-1 dispersion 3.1 g, Pigment-1 dispersion 30 g, Organic polyhalogen compound-2 dispersion 21 g, Organic polyhalogen compound- 3-dispersion 69g, phthalazine compound-1 solution 173g, SBR
Core-shell latex (core Tg: 20 ° C / shell Tg: 30 ° C
= 70/30 mass ratio) 1082 g of liquid, hydrogen bonding compound-2 dispersion 1
24 g and 9 g of mercapto compound-1 solution were sequentially added, and 110 g of silver halide mixed emulsion A was added immediately before coating, and a well-mixed emulsion layer coating solution was directly sent to a coating die.
Applied.

<< Preparation of Emulsion Surface Intermediate Layer Coating Solution >> 772 g of a 10% by mass aqueous solution of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.), 5.3 g of a 20% by mass dispersion of pigment, methyl methacrylate / styrene / butyl acrylate / Hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization mass ratio 64/9/20/5/2) 2 ml of a 27.5% by mass liquid latex, 2 ml of a 5% by mass aqueous solution of aerosol OT (manufactured by American Cyanamid Co.) 20% by mass aqueous solution of diammonium phthalate
0.5 ml, the water to a total volume 880g added, pH was adjusted with NaOH so as to be 7.5 and the intermediate layer coating solution was fed to a coating die to provide 10 ml / m ^2. The viscosity of the coating solution is
It was 21 [mPa · s] at 40 ° C. (No. 1 rotor, 60 rpm) with a B-type viscometer.

<< Preparation of Coating Solution for First Layer of Emulsion Surface Protective Layer >> 64 g of inert gelatin was dissolved in water, and methyl methacrylate was added.
/ Styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20
/ 5/2) 80 g of latex 27.5 mass% liquid, 23 ml of 10 mass% methanol solution of phthalic acid, 10 mass% of 4-methylphthalic acid
23 ml of aqueous solution, 28 ml of 0.5 mol / L sulfuric acid, aerosol
5m 5% aqueous solution of OT (American Cyanamid)
l, 0.5 g of phenoxyethanol and 0.1 g of benzoisothiazolinone were added to make a coating solution by adding water to a total amount of 750 g, and 18.6 ml of a 4% by mass chrome alum mixed with a static mixer immediately before coating was used. / m ² to the coating die. The viscosity of the coating solution was 17 mPa · s using a B-type viscometer at 40 ° C. (No. 1 rotor, 60 rpm).

<< Preparation of Coating Solution for Second Layer of Emulsion Surface Protective Layer >> 80 g of inert gelatin was dissolved in water, and methyl methacrylate was added.
/ Styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20
/ 5/2) 102 g of a latex 27.5% by mass liquid, 3.2 ml of a 5% by mass solution of a fluorine-based surfactant (F-1: potassium salt of N-perfluorooctylsulfonyl-N-propylalanine), a fluorine-based surfactant (F-2: polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-
Aminoethyl) ether [average degree of polymerization of ethylene oxide = 1
5]) of a 2% by weight aqueous solution, 23 ml of a 5% by weight solution of aerosol OT (manufactured by American Cyanamid Co., Ltd.), 4 g of polymethyl methacrylate fine particles (average particle diameter 0.7 μm), and polymethyl methacrylate fine particles (average particle (Diameter 4.5 μm) 21 g, 4-methylphthalic acid 1.6 g, phthalic acid 4.8 g, 0.5 mol / L sulfuric acid
Water was added to 44 ml, 10 mg of benzoisothiazolinone to make a total amount of 650 g, and 445 ml of an aqueous solution containing 4% by mass of chromium alum and 0.67% by mass of phthalic acid was mixed with a static mixer just before application to the surface. The coating solution for the protective layer was fed to the coating die at 8.3 ml / m ² . The viscosity of the coating solution is B type viscometer 40 ° C (No.1 rotor, 60r
pm) was 9 [mPa · s].

<< Preparation of Photothermographic Material-1 >> On the back surface side of the undercoat support, an antihalation layer coating solution was applied so that the solid content of the solid fine particle dye was 0.04 g / m ² .
The coating amount of the back surface protective layer was 1.7 g / m ² of gelatin.
And then dried to form a back layer. On the surface opposite to the back surface, the emulsion layer, the intermediate layer, the first protective layer, and the second protective layer were simultaneously coated in order from the undercoating surface by a slide bead coating method to prepare a photothermographic material sample. . At this time, the temperature of the emulsion layer and the intermediate layer was adjusted to 31 ° C., the temperature of the first protective layer was adjusted to 36 ° C., and the temperature of the first protective layer was adjusted to 37 ° C. The coating amount (g / m ² ) of each compound in the emulsion layer is as follows.

Silver behenate 6.19 Reducing agent-1 0.67 Reducing agent-2 0.54 Compounds of general formula (II) or (III) The types and amounts are shown in Table 1. Pigment (CI Pigment Blue 60) 0.032 polyhalogen compound-1 0.46 polyhalogen compound-2 0.25 phthalazine compound-1 0.21 SBR latex 11.1 mercapto compound-1 0.002 silver halide (as Ag) 0.145

The coating and drying conditions are as follows. The coating was performed at a speed of 160 m / min, the gap between the tip of the coating die and the support was set to 0.10 to 0.30 mm, and the pressure in the decompression chamber was set 196 to 882 Pa lower than the atmospheric pressure. The support was neutralized with ion wind before coating. In the following chilling zone,
After the coating solution is cooled by a wind having a dry-bulb temperature of 10 to 20 ° C, it is transported in a non-contact type, and a dry-bulb temperature is 23 to 45 ° C and a wet-bulb temperature is 15 to 21 in a helix type non-contact dryer. It dried with the drying wind of ° C.
After drying, humidity control at 25 ° C and relative humidity of 40-60%,
Heated to 70-90 ° C. After heating, the film surface was cooled to 25 ° C. The matte degree of the produced photothermographic material was 550 seconds on the photosensitive layer side and 130 seconds on the back side in Bekk smoothness. Also, when the pH of the film surface on the photosensitive layer side was measured,
6.0.

<< Preparation of Photothermographic Material-2 >> Emulsion layer coating solution-1 was added to photothermographic material-1.
The photothermographic material-2 was prepared in the same manner as the photothermographic material-1 except that the yellow dye compound 15 was removed from the antihalation layer. The coating amount (g / m ² ) of each compound in the emulsion layer at this time is as follows.

Silver behenate 6.19 Pigment (CI Pigment Blue 60) 0.036 Polyhalogen compound-2 0.13 Polyhalogen compound-3 0.41 Phthalazine compound-1 0.21 SBR latex 11.1 Reducing agent complex-3 1.54 Compound of general formula (II) or (III) Type and amount are described in Table 1. Mercapto compound-1 0.002 Silver halide (as Ag) 0.10

<< Preparation of Photothermographic Material-3 >> Emulsion layer coating solution-1 was added to photothermographic material-1.
3, and the yellow dye compound 15 was removed from the antihalation layer. Further, the fluorine-based surfactants F-1, F-2, F-3 and F-4 of the second protective layer and the back surface protective layer are each made of the same mass of F-5, F-6 and F-7.
And F-8. Others are photothermographic materials-1
In the same manner as in the above, a photothermographic material-3 was produced. The coating amount (g / m ² ) of each compound in the emulsion layer at this time is as follows.

Silver behenate 5.57 Pigment (CI Pigment Blue 60) 0.032 Reducing agent-4 0.40 Reducing agent-5 0.36 Compound of general formula (II) or (III) Type and amount Is described in Table 1. Development accelerator-1 0.017 Polyhalogen compound-2 0.12 Polyhalogen compound-3 0.37 Phthalazine compound-1 0.19 SBR latex 10.0 Hydrogen bonding compound-2 0.59 Mercapto Compound-1 0.002 Silver halide (as Ag) 0.09

The above reducing agents 1 to 5 are contained in the compound of the general formula (I). When two kinds of reducing agents are contained in the light-sensitive material, the amount of the compound of the general formula (I) is , The sum of the two. The chemical structures of the compounds used in the examples of the present invention are shown below.

[0165]

Embedded image

[0166]

Embedded image

[0167]

Embedded image

[0168]

Embedded image

[0169]

Embedded image

(Evaluation of Photographic Performance) The photographic material was exposed with a Fuji Medical Dry Laser Imager FM-DPL (with a 660 nm semiconductor laser with a maximum output of 60 mW (IIIB)). After exposure, the thermal development unit of FM-DPL was modified and thermally developed (4 panel heaters set at 112 ° C-119 ° C-121 ° C-121 ° C for a total of 24 seconds = a standard development time of 24 seconds). did. The obtained image was evaluated using a densitometer. This modified heat developing machine can make the developing time variable.
The sensitivity was evaluated by the reciprocal of the ratio of the exposure amount giving a density higher than Dmin by 1.0. The higher the value, the higher the feeling. From a practical point of view, it needs to be in the range of 95 to 105. The sample belonging to the photothermographic material-3 was evaluated at the time of thermal development = 14 seconds as a standard development time.

(Progressiveness) Processing was performed at a development time of 75% of the standard development time, and the evaluation was made based on the relative sensitivity difference between the standard development time and the 75% development time. Excellent as a progressive. (Evaluation of Image Tone) The color tone of the formed image was evaluated by sensory evaluation. The most preferred color tone is pure black tone, which is 0
Points. The case where the magenta taste is the strongest is set to -3 points, and -1 and-are set as the magenta taste becomes stronger from the pure black tone.
Two or three points were given. Conversely, the case where the yellow taste is the strongest is +3 points, and +1, +2, +3 points as the yellow taste becomes stronger from the pure black tone, and practically, it is necessary to be within the range of -1, 0, +1 points. is there.

Table 1 shows the results obtained for the above evaluations.
Shown in From the results shown in Table 1, it can be seen that the photothermographic material of the present invention is superior in photographic performance, color tone, and progress to the comparative example.

[0173]

[Table 1]

Example 2 In the samples of Experiment Nos. 1 to 18 in Table 1 of Example 1, the compound of the general formula (II) or (III) added to the emulsion layer was not added to the emulsion layer. Then, a photothermographic material (referred to as the photosensitive material of (1) of Example 2) was produced by adding the same amount as in Example 1. Further, in the samples of Experiment Nos. 1 to 18 in Table 1 of Example 1, the compound of the general formula (II) or (III) added to the emulsion layer was not added to the emulsion layer, but was added to the first layer of the protective layer. A heat-developable photosensitive material (referred to as the photosensitive material of (2) of Example 2) was prepared by adding so that the coating amount was twice as large as that of Example 1. When the photothermographic materials of Examples 1 and 2 were evaluated in the same manner as in Example 1, the same effects as in Example 1 were obtained.

[0175]

According to the constitution of the present invention, it is possible to provide an image having a good image tone and to provide a photosensitive material having good progress. The effect of the present invention is remarkably exhibited in a place where the developing time is short, and the configuration of the present invention can provide an image having good image tone even in a rapid processing system.

Claims (3)

[Claims] 1. A photothermographic material comprising at least one photosensitive silver halide, a non-photosensitive organic silver salt, a reducing agent for silver ions and a binder on one surface of a support, wherein (a) Containing at least one polyphenol compound represented by the following general formula (I) as the reducing agent;
(B) a compound containing at least one hindered phenol compound represented by the following general formula (II), and (c) a compound represented by the general formula (I) which is a compound represented by the general formula (II) A photothermographic material characterized in that the ratio (molar ratio) of the photothermographic material is 0.001 to 0.2. Embedded image (In the general formula (I), R ¹¹ and R ¹¹ ′ each independently represent a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms. R ¹² and R ¹² ′ each independently represent a hydrogen atom or a benzene ring. .L representing a substitutable group -S- group or a -CHR ¹³ - a represents a group .R ¹³ is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms .X ¹ and X ¹ 'Each independently represents a hydrogen atom or a group which can be substituted on a benzene ring. (In the general formula (II), R ¹ .R ² is hydrogen atom or a substituted or unsubstituted alkyl group, represents a substituted or unsubstituted alkyl group or a substituted or unsubstituted acylamino group, R ^1, R ² is not a 2-hydroxyphenylmethyl group, R ³ is a hydrogen atom or a substituted or unsubstituted alkyl group, and R ⁴ is a substituent that can be substituted on a benzene ring.) 2. The method according to claim 1, wherein the molar ratio of the compound represented by the general formula (II) to the compound represented by the general formula (I) is 0.005 to 0.1. Item 2. The photothermographic material according to item 1. 3. An image forming method, comprising processing the photothermographic material according to claim 1 for a heat development time of 5 to 20 seconds.