JP4284014B2 - Photothermographic material and image forming method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photothermographic material and an image forming method that can be suitably used for medical diagnosis, industrial photography, printing, COM, and the like.
[0002]
[Prior art]
Many photosensitive materials having a photosensitive layer on a support and forming an image by exposing the image are known. Among them, there is a technique for forming an image by thermal development as a system that contributes to environmental conservation and can simplify the image forming means.
For example, US Pat. Nos. 3,152,904, 3,457,075, and D.W. “Thermally Processed Silver Systems” by Klosterboer (Imaging Processes and Materials), 8th edition, J. Sturge (Walworth, edited by A. Shepp, Chapter 9, page 279, 1989). Such a photothermographic material usually contains a reducible non-photosensitive silver source (for example, an organic silver salt), a catalytically active amount of a photocatalyst (for example, a silver halide), and a silver reducing agent, usually dispersed in an organic binder matrix. Contained in the state. The photosensitive material is stable at normal temperature, but when exposed to a high temperature (for example, 80 ° C. or higher) after exposure, silver is oxidized through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and the reducing agent. Is generated. This redox reaction is promoted by the catalytic action of the latent image formed by exposure. The silver produced by the reaction of the reducible silver salt in the exposed area turns black and forms an image because it contrasts with the unexposed area.
[0003]
A wide range of reducing agents have been disclosed in photothermographic materials using organic silver salts. For example, JP-A-46-6074, 47-1238, 47-33621, 49-46427, 49-115540, 50-14334, 50-36110 Publication No. 50-147711 Publication No. 51-32632 Publication No. 51-1023721 Publication No. 51-32324 Publication No. 51-51933 Publication No. 52-84727 Publication No. 55-108654 Gazette, 56-146133, 57-82828, 57-82829, JP-A-6-3793, U.S. Pat. No. 3,667,9586, and 3,679,426. No. 3,751,252 No. 3,751,255 No. 3,761,270 No. 3,7 No. No. 2,949, No. 3,839,048, No. 3,928,686, No. 5,464,738, German Patent No. 2,321,328 Examples thereof include reducing agents disclosed in the specification, European Patent Publication No. 692,732, and the like.
[0004]
Among these known reducing agents, hindered phenol compounds and bisphenol compounds are widely used. However, the photothermographic materials using these reducing agents may require problems to develop in order to obtain a sufficient image density, and problems such as large sensitivity fluctuations with respect to the development temperature may occur. There are techniques to solve these problems.
[0005]
As a means for solving these problems, a development accelerator is used, and among them, a compound having a reducing property is used. For example, JP-A-10-221806 discloses sulfonamide phenol compounds. On the other hand, as a known reducing compound in a photothermographic material, it is disclosed in, for example, US Pat. No. 5,496,695 and JP-A-9-304875 that ultra-high performance is obtained by using a hydrazine derivative. Yes.
[0006]
However, when the compounds disclosed therein are added to a photothermographic material for medical imaging applications that do not require ultra-high contrast photographic characteristics, significant fog occurs, gradation is too high, and image reproducibility is reduced. It is not possible to obtain a product that can be used as a product due to such problems.
As described above, when a known development accelerator or a known hydrazine derivative as described above is used, the development acceleration effect is not sufficient, the gradation is too high, the image reproducibility is lowered, and However, problems such as insufficient stability during storage in photosensitive materials may occur due to various factors such as combinations with other additives, manufacturing conditions of photosensitive materials, development temperatures, and the passage of time. This has been a major problem in designing development photosensitive materials. Therefore, a novel photothermographic material that solves these problems has been desired.
[0007]
[Problems to be solved by the invention]
An object of the present invention is to solve the conventional problems and achieve the following objects. That is, an object of the present invention is to provide a novel photothermographic material and an image forming method that have high sensitivity, little fogging, rapid development, and little change in performance due to fluctuations in thermal development temperature.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a photothermographic material having at least a photosensitive silver halide, a reducible silver salt, and a binder on the same surface of the support has a specific property. It has been found that by using a compound having a structure, an excellent photothermographic material having a desired effect can be provided, and the present invention has been completed.
[0009]
  That is, the present invention comprises at least photosensitive silver halide on the same surface of the support,Organic silver saltA photothermographic material comprising: a binder; a compound represented by the following general formula (1) or (2); and a compound represented by the following general formula (3).
[0010]
[Chemical formula 2]
[0011]
(In the general formula (1), R¹Represents an alkyl group, an aryl group, an alkenyl group or an alkynyl group, and X¹Represents an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group or a sulfamoyl group. Y¹~ Y⁵Each independently represents a hydrogen atom or a substituent. );
(In the general formula (2), X²¹Is -NX³¹X³²Represents a group. X³¹And X³²Each independently represents a hydrogen atom or a substituent.Y ²⁵ Represents an alkoxy group or an aryloxy group.Y²¹~Y ²⁴ ,as well asY²⁶Each independently represents a hydrogen atom or a substituent. );
(In general formula (3), V²~ V⁹Each independently represents a hydrogen atom or a substituent. L is -CH (V¹⁰)-Or -S-¹⁰Represents a hydrogen atom or a substituent. ).
[0012]
In the compound represented by the general formula (1), X¹Preferably represents a carbamoyl group, more preferably an alkylcarbamoyl group or an arylcarbamoyl group, and particularly preferably an arylcarbamoyl group.
In the compound represented by the general formula (1), R¹Preferably represents an alkyl group or an aryl group.
[0013]
The photothermographic material of the invention preferably further contains an ultrahigh contrast agent.
[0014]
The image forming method of the present invention is characterized in that the photothermographic material of the present invention is exposed to light and then thermally developed to form an image.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The photothermographic material of the present invention will be described in detail below. In the present specification, “to” is a range including numerical values described before and after that as a minimum value and a maximum value.
[0016]
The photothermographic material of the present invention is represented by at least a photosensitive silver halide, a reducible silver salt, a binder, and the following general formula (1) or (2) on the same surface of a support. It contains a compound and a compound represented by the following general formula (3). The photothermographic material of the invention is represented by the following general formula (1) or (2) and the following general formula (3) as a reducing agent for a reducible silver salt (organic silver salt). Since it is used in combination with a compound to be produced, it has high sensitivity, little fogging, rapid development, and little change in performance due to fluctuations in heat development temperature. This is because when a photothermographic material is thermally developed, a compound represented by the following general formula (1) or (2) acts as a highly active reducing agent together with a compound represented by the general formula (3). Contributing to the formation of an image, it itself becomes an oxidant, but it is re-reduced and regenerated by a redox reaction with a compound represented by the general formula (3), and again acts as a highly active reducing agent. Therefore, it is presumed that a photothermographic material having high sensitivity, little fog, rapid development, and little change in performance due to fluctuations in the heat development temperature can be obtained.
[0017]
A preferred form of the photothermographic material of the present invention has an image forming layer containing an organic silver salt and a binder as a reducible silver salt on a support, and contains a photosensitive silver halide on the image forming layer side. And a photosensitive silver halide emulsion layer (photosensitive layer). Preferably, the image forming layer is a photosensitive layer. A particularly preferred form is a super high contrast photosensitive material containing a developing agent on the image forming layer side, and preferably further containing a super high contrast agent. In particular, in such a photothermographic material, by using a compound represented by the following general formula (1) or (3) and a compound represented by the following general formula (2) in combination, A good image can be obtained without lowering the maximum density (Dmax) and sensitivity and without increasing fog (Dmin) in the unexposed area.
[0018]
First, the compounds represented by the general formulas (1) to (3) will be described.
Hereinafter, the compound represented by the general formula (1) will be described.
[0019]
[Chemical 3]
[0020]
In the general formula (1), R¹Represents an alkyl group, an aryl group, an alkenyl group, or an alkynyl group.
R¹Is preferably a linear, branched, cyclic or a combination thereof having 1 to 30 carbon atoms, more preferably 1 to 16 carbon atoms, and still more preferably 1 to 13 carbon atoms. For example, methyl, Ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, n-hexyl, cyclohexyl, n-octyl, t-octyl, n-amyl, t-amyl, n-decyl, n-dodecyl, Examples thereof include n-tridecyl, benzyl, phenethyl and the like.
R¹Is preferably 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, and still more preferably 6 to 12 carbon atoms. For example, phenyl, 4-methylphenyl, 2-chlorophenyl, 4-chlorophenyl, 2 , 4-dichlorophenyl, 3,4-dichlorophenyl, 2-methoxyphenyl, 4-methoxyphenyl, 4-hexyloxyphenyl, 2-dodecyloxyphenyl, naphthyl and the like.
R¹Is preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, still more preferably 2 to 12 carbon atoms, such as a vinyl group, an allyl group, an isopropenyl group, a butenyl group, and a cyclohexenyl group. And so on.
R¹Is preferably 2-30 carbon atoms, more preferably 2-20 carbon atoms, still more preferably 2-12 carbon atoms, and examples thereof include an ethynyl group and a propynyl group.
R¹May further have a substituent. Examples of preferred substituents include Y of the compound of formula (I) described later.¹~ Y^FiveThe group represented by these can be mentioned.
R¹More preferably represents an alkyl group or an aryl group, and particularly preferably represents an alkyl group.
[0021]
In the compound of the general formula (1), X¹Represents an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group or a sulfamoyl group.
X¹Is preferably 2-20, more preferably 2-16, and even more preferably 2-12, such as acetyl, propionyl, butyryl, valeryl, hexanoyl, myristyl, palmitoyl, stearyl, Examples include oleyl, acryloyl, cyclohexanecarbonyl, benzoyl, formyl, pivaloyl and the like.
X¹Is preferably 2-20 carbon atoms, more preferably 2-16 carbon atoms, still more preferably 2-12 carbon atoms, and examples thereof include methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, phenoxycarbonyl and the like. .
X¹Is preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, such as carbamoyl, N, N-diethylcarbamoyl, N-dodecylcarbamoyl, N- Decylcarbamoyl, N-hexadecylcarbamoyl, N-phenylcarbamoyl, N- (2-chlorophenyl) carbamoyl, N- (4-chlorophenyl) carbamoyl, N- (2,4-dichlorophenyl) carbamoyl, N- (3,4- Dichlorophenyl) carbamoyl, N-pentachlorophenylcarbamoyl, N- (2-methoxyphenyl) carbamoyl, N- (4-methoxyphenyl) carbamoyl, N- (2,4-dimethoxyphenyl) carbamoyl, N- (2-dodecyloxy) Phenyl) carbamoyl, N- ( - dodecyloxyphenyl) carbamoyl, and the like.
X¹Is preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, such as mesyl, ethanesulfonyl, cyclohexanesulfonyl, benzenesulfonyl, tosyl, 4-chlorobenzene. And sulfonyl.
X¹Is preferably 0-20, more preferably 0-16, and still more preferably 0-12. For example, sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl Etc.
X¹May further have a substituent. Examples of preferred substituents include Y of the compound of formula (I) described later.¹~ Y^FiveThe group represented by these can be mentioned.
X¹Preferably represents a carbamoyl group, more preferably an alkylcarbamoyl group or an arylcarbamoyl group, and particularly preferably an arylcarbamoyl group.
[0022]
In general formula (1), Y¹~ Y^FiveEach independently represents a hydrogen atom or a substituent.
Y¹~ Y^FiveAny substituent may be used as long as it does not adversely affect photographic properties. For example, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a linear, branched, cyclic or a combination thereof (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably Are 1 to 13, for example, methyl, ethyl, n-propyl, isopropyl, sec-butyl, t-butyl, t-octyl, n-amyl, t-amyl, n-dodecyl, n-tridecyl, cyclohexyl, etc.) An alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 12 carbon atoms such as vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), an aryl group (preferably carbon The number is 6 to 30, more preferably 6 to 20, and still more preferably 6 to 12. For example, phenyl, p-methylphenyl, Til, etc.), an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, more preferably 1 to 12, such as methoxy, ethoxy, propoxy, butoxy, etc.), an aryloxy group (preferably carbon The number is 6 to 30, more preferably 6 to 20, and further preferably 6 to 12. For example, phenyloxy, 2-naphthyloxy and the like, acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms). More preferably, it is 2-12, for example, acetoxy, benzoyloxy etc.), an amino group (preferably C0-20, more preferably 1-16, still more preferably 1-12, for example, dimethylamino Group, diethylamino group, dibutylamino group, anilino group, etc.), acylamino group (preferably having 2 to 20 carbon atoms, and more) It is preferably 2 to 16, more preferably 2 to 13, for example, acetylamino, tridecanoylamino, benzoylamino, etc., a sulfonylamino group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, More preferably, it is 1-12, for example, methanesulfonylamino, butanesulfonylamino, benzenesulfonylamino, etc., a ureido group (preferably having 1-20 carbon atoms, more preferably 1-16, more preferably 1-12. Yes, for example, ureido, methylureido, phenylureido, etc.), carbamate groups (preferably having 2-20 carbon atoms, more preferably 2-16, further preferably 2-12, such as methoxycarbonylamino, phenyloxycarbonyl Amino), carboxyl group, carbamoyl group (preferably C1-C20, More preferably, it is 1-16, More preferably, it is 1-12, for example, carbamoyl, N, N-diethylcarbamoyl, N-dodecylcarbamoyl, N-phenylcarbamoyl etc.), alkoxycarbonyl groups (preferably Has 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, more preferably 2 to 12 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, etc.), an acyl group (preferably 2 to 20 carbon atoms, more preferably 2 to 16, more preferably 2 to 12, for example, acetyl, benzoyl, formyl, pivaloyl, etc.), sulfo group, sulfonyl group (preferably 1 to 20 carbon atoms, more preferably 1 to 16, more preferably 1) -12, for example, mesyl, tosyl, etc.), sulfamoyl group (preferably C 0-20, more preferably 0-16, still more preferably 0-12, such as sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, phenylsulfamoyl, etc.), cyano group, nitro group, hydroxyl Group, mercapto group, alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, more preferably 1 to 12, such as methylthio, butylthio, etc.), heterocyclic group (preferably having 2 to 2 carbon atoms). 20, more preferably 2 to 16, still more preferably 2 to 12, and examples thereof include pyridyl, imidazolyl, pyrrolidyl and the like. These substituents may be further substituted with other substituents.
Y¹~ Y^FiveAmong the above, preferred as the substituent represented by halogen atom, alkyl group, aryl group, alkoxy group, aryloxy group, acyloxy group, anilino group, acylamino group, sulfonylamino group, carboxyl group, carbamoyl group, An acyl group, a sulfo group, a sulfonyl group, a sulfamoyl group, a cyano group, a hydroxyl group, a mercapto group, an alkylthio group, and a heterocyclic group.
[0023]
In the general formula (1), R¹Is an alkyl group, X¹Is a carbamoyl group, Y¹~ Y^FiveA combination in which is a hydrogen atom is preferred.
[0024]
Although the specific example of a compound represented by General formula (1) below is given, the compound used for this invention is not limited by these specific examples.
[0025]
[Formula 4]
[0026]
[Chemical formula 5]
[0027]
[Chemical 6]
[0028]
[Chemical 7]
[0029]
[Chemical 8]
[0030]
[Chemical 9]
[0031]
[Chemical Formula 10]
[0032]
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[0033]
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[0034]
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[0035]
Hereinafter, the compound represented by the following general formula (2) will be described.
[0036]
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[0037]
In general formula (2), X^{twenty one}Is -NX³¹X³²Represents a group. X³¹And X³²Each independently represents a hydrogen atom or a substituent.
[0038]
In general formula (2), X³¹And X³²Any substituent may be used as long as it can be substituted with a nitrogen atom. For example, linear, branched, cyclic, or a combination thereof (preferably having a carbon number of 1-20, more preferably 1-16, still more preferably 1-13, such as methyl, ethyl, n-propyl, isopropyl , Sec-butyl, t-butyl, t-octyl, n-amyl, t-amyl, n-dodecyl, n-tridecyl, cyclohexyl, etc., an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms). More preferably, it is 2-12, for example, vinyl, allyl, 2-butenyl, 3-pentenyl etc.), an aryl group (preferably 6-30 carbon atoms, more preferably 6-20, still more preferably 6-12). For example, phenyl, p-methylphenyl, naphthyl, etc.), an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 16, more preferably 1 to 12, for example, methoxy, ethoxy, propoxy, butoxy, etc.), an aryloxy group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, still more preferably 6 to 12 carbon atoms). , For example, phenyloxy, 2-naphthyloxy, etc., carboxyl group, carbamoyl group (preferably having a carbon number of 1-20, more preferably 1-16, still more preferably 1-12, for example, carbamoyl, N, N -Diethylcarbamoyl, N-dodecylcarbamoyl, N-phenylcarbamoyl, etc.), an alkoxycarbonyl group (preferably having 2-20 carbons, more preferably 2-16, still more preferably 2-12, such as methoxycarbonyl, ethoxy Carbonyl, butoxycarbonyl, etc.), acyl group (preferably carbon 2 to 20, more preferably 2 to 16, and further preferably 2 to 12, for example, acetyl, benzoyl, formyl, pivaloyl, etc.), sulfo group, sulfonyl group (preferably having 1 to 20 carbon atoms, more preferably 1) -16, more preferably 1-12, such as mesyl, tosyl, etc., hydroxyl group, heterocyclic group (preferably having 2-20 carbon atoms, more preferably 2-16, more preferably 2-12. For example, pyridyl, imidazolyl, pyrrolidyl, etc.). These substituents may be further substituted with other substituents.
[0039]
In general formula (2), X^{twenty one}Are preferably acylamide groups (acetamide, propionylamide, butyrylamide, valerylamino, hexanoylamide, myristylamino, palmitoylamino, stearylamino, oleylamino, acryloylamino, cyclohexanecarboxyamide, benzoylamide, 2-chlorobenzoylamide, 4 -Chlorobenzoylamide, 2,4-dichlorobenzoylamide, 3,4-dichlorobenzoylamide, 2-methoxybenzoylamide, 2-dodecyloxy-chlorobenzoylamide, 4-dodecyloxy-chlorobenzoylamino, formamide, pivaloylamino, etc.) , Sulfonamide groups (methanesulfonylamide, ethanesulfonylamide, cyclohexanesulfonylamide, benzenesulfonylamide, toluene Sulfonylamide, 4-chlorobenzenesulfonylamide, etc.), diacylamide groups (diacetamide, dibenzamide, etc.), imide groups (phthalimide, succinimide, etc.), ureido groups (N-methylureido, N, N-dimethylureido, etc.) To express.
[0040]
  In general formula (2),Y ²⁵ Represents an alkoxy group or an aryloxy group.Y²¹~Y ²⁴ ,as well asY²⁶Each independently represents a hydrogen atom or a substituent.
  Y²¹~Y ²⁴ ,as well asY²⁶As the substituent represented by formula (1), Y of the compound of the general formula (1)¹~ Y^FiveThe substituent similar to the substituent represented by these can be mentioned. Y²¹~Y ²⁴ ,as well asY²⁶Preferred examples of the substituent represented by formula (1) include a halogen atom, alkyl group, aryl group, alkoxy group, aryloxy group, acyloxy group, anilino group, acylamino group, sulfonylamino group, carboxyl group, carbamoyl group, acyl group, sulfo group. Group, sulfonyl group, sulfamoyl group, cyano group, hydroxyl group, mercapto group, alkylthio group, and heterocyclic group.
[0041]
Although the specific example of a compound represented by General formula (2) below is given, the compound used for this invention is not limited by these specific examples.
[0042]
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[0043]
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[0044]
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[0045]
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[0046]
The compound represented by the general formula (1) or (2) can be easily synthesized by a method known in the photographic industry.
The compound represented by the general formula (1) or (2) is water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethyl It can be used by dissolving in sulfoxide, methyl cellosolve and the like.
Alternatively, using a well-known emulsification dispersion method, dissolve using an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically emulsify and disperse. An object can be made and used. Alternatively, the compound powder can be dispersed in water and used by a ball mill, colloid mill, sand grinder mill, manton gourin, microfluidizer or ultrasonic wave according to the well-known solid dispersion method.
[0047]
The compound represented by the general formula (1) or (2) may be added to any layer on the support as long as the surface is the same as the photosensitive silver halide and the reducible silver salt. It is preferable to add to a layer containing silver halide or a layer adjacent thereto.
The addition amount of the compound represented by the general formula (1) or (2) is preferably 0.2 to 200 mmol, more preferably 0.3 to 100 mmol, and further preferably 0.5 to 1 mol of silver. ~ 30 mmol. The compounds represented by the general formula (1) or (2) may be used alone or in combination of two or more.
[0048]
Hereinafter, the compound represented by the general formula (3) will be described.
[0049]
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[0050]
In general formula (3), V²~ V⁹Each independently represents a hydrogen atom or a substituent. V²~ V⁹The substituents represented by may be the same or different, and preferred examples include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a linear, branched, cyclic, or a combination thereof. (Preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 13 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, sec-butyl, t-butyl, t-octyl, n -Amyl, t-amyl, n-dodecyl, n-tridecyl, cyclohexyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 12 carbon atoms such as vinyl, Allyl, 2-butenyl, 3-pentenyl, etc.) and aryl groups (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, still more preferably 6 to 12, for example, phenyl, p-methylphenyl, naphthyl, etc.), an alkoxy group (preferably having a carbon number of 1-20, more preferably 1-16, still more preferably 1-12, for example, methoxy, Ethoxy, propoxy, butoxy, etc.), aryloxy groups (preferably having 6 to 30 carbon atoms, more preferably 6 to 20, more preferably 6 to 12, such as phenyloxy, 2-naphthyloxy, etc.), acyloxy groups (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, more preferably 2 to 12 carbon atoms, such as acetoxy, benzoyloxy, etc.), amino group (preferably having 0 to 20 carbon atoms, more preferably 1 to 2 carbon atoms). 16, more preferably 1 to 12, for example, dimethylamino group, diethylamino group, dibutylamino group, Group, etc.), an acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16, more preferably 2 to 13, such as acetylamino, tridecanoylamino, benzoylamino, etc.), a sulfonylamino group (Preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms such as methanesulfonylamino, butanesulfonylamino, benzenesulfonylamino, etc.), ureido groups (preferably having 1 to 1 carbon atoms). 20, More preferably, it is 1-16, More preferably, it is 1-12, for example, ureido, methylureido, phenylureido etc.), carbamate group (preferably C2-C20, more preferably 2-16, more preferably Are from 2 to 12, for example, methoxycarbonylamino, phenyloxycarbo Nylamino, etc.), a carboxyl group, a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 and still more preferably 1 to 12, such as carbamoyl, N, N-diethylcarbamoyl, N-dodecylcarbamoyl, N-phenylcarbamoyl etc.), alkoxycarbonyl group (preferably having 2-20 carbon atoms, more preferably 2-16, still more preferably 2-12, such as methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl etc.), acyl group (Preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, further preferably 2 to 12 carbon atoms such as acetyl, benzoyl, formyl, pivaloyl, etc.), sulfo group, sulfonyl group (preferably having 1 to 20 carbon atoms) More preferably, it is 1-16, More preferably, it is 1-12 , For example, mesyl, tosyl, etc.), a sulfamoyl group (preferably having a carbon number of 0-20, more preferably 0-16, still more preferably 0-12, such as sulfamoyl, methylsulfamoyl, dimethylsulfamoyl, Phenylsulfamoyl etc.), cyano group, nitro group, hydroxyl group, mercapto group, alkylthio group (preferably having 1 to 20, more preferably 1 to 16, more preferably 1 to 12, such as methylthio, Butylthio and the like), heterocyclic groups (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, more preferably 2 to 12 carbon atoms such as pyridyl, imidazolyl, pyrrolidyl, etc.). These substituents may be further substituted with other substituents.
V²~ V⁹Particularly preferred as a substituent represented by formula (1) is an alkyl group (for example, methyl, ethyl, n-propyl, isopropyl, sec-butyl, t-butyl, t-octyl, n-amyl, t-amyl, n-dodecyl). N-tridecyl, cyclohexyl, etc.).
[0051]
In the general formula (3), L represents —CH (V^Ten)-Or -S-^TenRepresents a hydrogen atom or a substituent. V^TenAs preferable examples of the substituent represented by formula (1), a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a linear, branched, cyclic, or a combination thereof (preferably having 1 to 20 carbon atoms) More preferably, it is 1-16, More preferably, it is 1-13, for example, methyl, ethyl, n-propyl, isopropyl, sec-butyl, t-butyl, t-octyl, n-amyl, t-amyl, n -Dodecyl, n-tridecyl, cyclohexyl, 2,4,4-trimethylpentyl, etc.), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 12 carbon atoms such as vinyl , Allyl, 2-butenyl, 3-pentenyl, etc.), an aryl group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, further preferred) 6 to 12, for example, phenyl, p-methylphenyl, naphthyl, etc.), an alkoxy group (preferably having a carbon number of 1-20, more preferably 1-16, still more preferably 1-12, Methoxy, ethoxy, propoxy, butoxy and the like), an aryloxy group (preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, still more preferably 6 to 12 carbon atoms such as phenyloxy and 2-naphthyloxy). An acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, more preferably 2 to 12 carbon atoms such as acetoxy, benzoyloxy, etc.), an amino group (preferably having 0 to 20 carbon atoms, more preferably 1 to 16, more preferably 1 to 12, for example, dimethylamino group, diethylamino group, dibutylamino group, Nilino group etc.), acylamino group (preferably having 2-20 carbon atoms, more preferably 2-16, further preferably 2-13, such as acetylamino, tridecanoylamino, benzoylamino, etc.), sulfonylamino group (Preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms such as methanesulfonylamino, butanesulfonylamino, benzenesulfonylamino, etc.), ureido groups (preferably having 1 to 1 carbon atoms). 20, More preferably, it is 1-16, More preferably, it is 1-12, for example, ureido, methylureido, phenylureido etc.), carbamate group (preferably C2-C20, more preferably 2-16, more preferably Are 2 to 12, for example, methoxycarbonylamino, phenyloxyca Rubanoylamino etc.), carboxyl group, carbamoyl group (preferably having 1-20 carbon atoms, more preferably 1-16, still more preferably 1-12, for example, carbamoyl, N, N-diethylcarbamoyl, N-dodecylcarbamoyl) N-phenylcarbamoyl etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 12, eg methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl etc.), acyl A group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, still more preferably 2 to 12 carbon atoms such as acetyl, benzoyl, formyl, pivaloyl, etc.), a sulfo group, and a sulfonyl group (preferably having 1 to 1 carbon atoms). 20, more preferably 1-16, still more preferably 1-12 Yes, for example, mesyl, tosyl, etc.), a sulfamoyl group (preferably having a carbon number of 0-20, more preferably 0-16, still more preferably 0-12, such as sulfamoyl, methylsulfamoyl, dimethylsulfamoyl) , Phenylsulfamoyl, etc.), cyano group, nitro group, hydroxyl group, mercapto group, alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16, more preferably 1 to 12, such as methylthio , Butylthio and the like), a heterocyclic group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, further preferably 2 to 12 carbon atoms such as pyridyl, imidazolyl, pyrrolidyl, etc.). These substituents may be further substituted with other substituents.
V^TenParticularly preferred examples of the substituent represented by formula (1) include an alkyl group (for example, methyl, ethyl, n-propyl, isopropyl, sec-butyl, t-butyl, t-octyl, n-amyl, n-octyl, t- Amyl, n-dodecyl, n-tridecyl, cyclohexyl, 2,4,4-trimethylpentyl, etc.), alkenyl group (eg, vinyl, allyl, 2-butenyl, 3-pentenyl, etc.), aryl group (eg, phenyl, p -Methylphenyl, naphthyl, etc.), hydroxyl group, mercapto group, alkylthio group (for example, methylthio, butylthio, etc.) and the like.
[0052]
Although the specific example of a compound represented by General formula (3) below is given, the compound used for this invention is not limited to these.
[0053]
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[0054]
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[0055]
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[0056]
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[0057]
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[0058]
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[0059]
The compound represented by the general formula (3) may be added by any method such as a solution, a powder, or a solid fine particle dispersion. The solid fine particle dispersion is performed by a known finer means (for example, ball mill, vibration ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). A dispersion aid may be used when dispersing the solid fine particles. The compound represented by the general formula (3) may be added to any layer as long as it is the same surface as the photosensitive silver halide and the reducible silver salt on the support, but includes silver halide. It is preferable to add to a layer or a layer adjacent thereto.
[0060]
The photothermographic material of the present invention contains a reducing agent for other reducible silver salts (organic silver salts) in addition to the compounds represented by the general formulas (1) to (3). Also good. The reducing agent for other reducible silver salts (organic silver salts) is any substance, preferably an organic substance, that reduces silver ions to metallic silver. In addition to conventional photographic developers such as phenidone, hydroquinone and catechol, hindered phenol reducing agents can also be mentioned as preferred examples. The reducing agent is preferably contained in an amount of 5 to 50 mol%, more preferably 10 to 40 mol%, based on 1 mol of silver on the surface having the image forming layer. The addition layer of the reducing agent may be any layer on the image forming layer side with respect to the support. When it is added to a layer other than the image forming layer, it is preferably used in a large amount of 10 to 50 mol% with respect to 1 mol of silver. The reducing agent may be a so-called precursor that is derivatized so as to have an effective function only during development.
[0061]
In the photothermographic material of the invention, the reducing agent (compounds represented by the general formulas (1) to (3)) is a bisphenol having an aromatic hydroxyl group (—OH). It is preferable to use together a non-reducing compound having a group capable of forming a hydrogen bond (hereinafter referred to as a hydrogen bonding compound). 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. Can be mentioned. Among them, preferred are a phosphoryl group, a sulfoxide group, an amide group (however, it has no> N—H group and is blocked like> N—R (R is a substituent other than H)), a urethane group. (However, it has no> N—H group and is blocked like> N—R (R is a substituent other than H)), a ureido group (however, it has no> N—H group,> N—R (wherein R is a substituent other than H)).
Particularly preferable examples of the hydrogen bonding compound include phosphine oxide compounds described in Japanese Patent Application No. 2000-74278.
Similar to the reducing agent, the hydrogen bonding compound can be contained in the coating solution in the form of a solution, an emulsified dispersion, or a solid dispersed fine particle dispersion, and used in the photosensitive material. A hydrogen bonding compound forms a hydrogen bonding complex with a compound having a phenolic hydroxyl group or an amino group in a solution state. Depending on the combination of a reducing agent and a hydrogen bonding compound, a single compound in a crystalline state is formed as a complex. Can be separated. The use of the crystal powder isolated in this way as a solid dispersed fine particle dispersion is particularly preferable for obtaining stable performance. Further, a method in which a reducing agent and a hydrogen bonding compound are mixed in powder form, and a complex is formed at the time of dispersion using a sand grinder mill or the like using an appropriate dispersant can be preferably used.
The hydrogen bonding compound is preferably used in the range of 1 to 200 mol%, more preferably in the range of 10 to 150 mol%, still more preferably in the range of 30 to 100 mol% with respect to the reducing agent. .
[0062]
Next, the photosensitive silver halide will be described.
The photosensitive silver halide is not particularly limited as a halogen composition, and silver chloride, silver chlorobromide, silver bromide, silver iodobromide, and silver iodochlorobromide can be used.
Methods for forming photosensitive silver halide are well known in the art, such as those described in Research Disclosure No. 17029, June 1978, and US Pat. No. 3,700,458. Specifically, a method in which a photosensitive silver halide is prepared by adding a silver supply compound and a halogen supply compound to gelatin or another polymer solution and then mixed with an organic silver salt is used. . In addition, the method described in paragraph Nos. 0217 to 0224 of JP-A No. 11-119374 and the methods described in Japanese Patent Application Nos. 11-98708 and 11-84182 are also preferable.
[0063]
The grain size of the photosensitive silver halide is preferably small for the purpose of keeping the cloudiness after image formation low, specifically 0.20 μm or less, more preferably 0.01 μm or more and 0.15 μm or less, and still more preferably. It is preferably 0.02 μm or more and 0.12 μm or less. The grain size here means the diameter when converted into a circular image having the same area as the projected area of silver halide grains (in the case of tabular grains, the projected area of the main plane).
[0064]
Examples of the shape of the photosensitive silver halide grains include cubes, octahedrons, tetradecahedrons, tabular shapes, spherical shapes, rod shapes, potato shapes, and the like. preferable. The characteristics of the particle shape such as the aspect ratio and the surface index of the particles are the same as those described in paragraph No. 0225 of JP-A-11-119374. Further, the distribution of the halogen composition may be uniform inside and on the surface of the silver halide grains, the halogen composition may be changed stepwise, or may be continuously changed. Further, silver halide grains having a core / shell structure can be preferably used. As the structure, core / shell particles having a preferably 2- to 5-fold structure, more preferably a 2- to 4-fold structure can be used. A technique of localizing silver bromide on the surface of silver chloride or silver chlorobromide grains can also be preferably used.
[0065]
As the photosensitive silver halide grains, silver halide grains in which a hexacyano metal complex is present on the outermost surface of the grains are preferable. As the hexacyano metal complex, [Fe (CN)₆]^Four-, [Fe (CN)₆]^3-, [Ru (CN)₆]^Four-, [Os (CN)₆]^Four-, [Co (CN)₆]^3-, [Rh (CN)₆]^3-, [Ir (CN)₆]^3-, [Cr (CN)₆]^3-, [Re (CN)₆]^3-Etc. In the present invention, a hexacyano Fe complex is preferred.
.
The hexacyano metal complex is present in the form of ions in an aqueous solution, so the counter cation is not important, but it is easy to mix with water and is compatible with precipitation operations for photosensitive silver halide emulsions. , Alkali metal ions such as rubidium ion, cesium ion and lithium ion, ammonium ion, alkylammonium ion (for example, tetramethylammonium ion, tetraethylammonium ion, tetrapropylammonium ion, tetra (n-butyl) ammonium ion) preferable.
In addition to water, the hexacyano metal complex is miscible with a mixed solvent or gelatin with an appropriate organic solvent miscible with water (for example, alcohols, ethers, glycols, ketones, esters, amides, etc.). Can be added.
The amount of hexacyano metal complex added is 1 × 10 5 per mole of silver.^-Five1 x 10 moles or more^-2Or less, more preferably 1 × 10^-Four1 x 10 moles or more^-3Less than or equal to mole
.
In order for the hexacyano metal complex to be present on the outermost surface of the silver halide grain, the chalcogen sensitization of sulfur sensitization, selenium sensitization and tellurium sensitization is completed after the addition of the aqueous silver nitrate solution used for grain formation. It is added directly before the completion of the preparation step before the chemical sensitization step for performing noble metal sensitization such as sensitization and gold sensitization, during the washing step, during the dispersion step, or before the chemical sensitization step. In order to prevent the silver halide fine grains from growing, it is preferable to add the hexacyano metal complex immediately after the grain formation, and it is preferable to add it before the completion of the preparation step.
The addition of the hexacyano metal complex may be started after adding 96% by mass of the total amount of silver nitrate to be added to form grains, more preferably starting after adding 98% by mass, The addition of 99% by mass is particularly preferable.
When the hexacyano metal complex is added after adding the aqueous silver nitrate solution just before the completion of grain formation, it can be adsorbed on the outermost surface of the silver halide grain, and most of it forms a sparingly soluble salt with silver ions on the grain surface. . This silver salt of hexacyanoiron (II) is a less soluble salt than AgI, so that re-dissolution by fine particles can be prevented and silver halide fine particles having a small particle size can be produced. .
[0066]
The particle size distribution of the photosensitive silver halide grains has a monodispersity value of 30% or less, preferably 1 to 20%, and further 5 to 15%. Here, the monodispersity is defined as a percentage (%) (coefficient of variation) of a value obtained by dividing the standard deviation of the particle diameter by the average particle diameter. For the sake of convenience, the grain size of silver halide grains is represented by a ridge length in the case of cubic grains, and the other grains (octahedron, tetrahedron, flat plate, etc.) are calculated by the projected area circle equivalent diameter.
The photosensitive silver halide grains contain a group VII or group VIII metal or metal complex of the periodic table. The central metal of the group VII or VIII metal or metal complex of the periodic table is preferably rhodium, rhenium, ruthenium, osnium or iridium. Particularly preferred metal complexes are (NH_Four)_ThreeRh (H₂O) Cl_Five, K₂Ru (NO) Cl_Five, K_ThreeIrCl₆, K_FourFe (CN)₆It is. 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 1 x 10 per mole of silver.^-9Mol ~ 1 × 10^-3The molar range is preferred, 1 × 10^-8Mol ~ 1 × 10^-FourA molar range is more preferred. As a specific metal complex structure, a metal complex having a structure described in JP-A-7-225449 can be used. The types and addition methods of these heavy metals are described in paragraph numbers 0227 to 0240 of JP-A-11-119374.
[0067]
The photosensitive silver halide grains can be desalted by a water washing method known in the art such as a noodle method or a flocculation method, but in the present invention, it may or may not be desalted.
[0068]
The photosensitive silver halide grains are preferably chemically sensitized. For chemical sensitization, it is preferable to use the method described in paragraph Nos. 0242 to 0250 of JP-A-11-119374. A thiosulfonic acid compound may be added to the photosensitive silver halide emulsion by the method described in European Patent Publication No. 293,917.
[0069]
As gelatin contained in the photosensitive silver halide grains (emulsion), low molecular weight gelatin may be used in order to maintain a good dispersion state of the photosensitive silver halide emulsion in the organic silver salt-containing coating solution. preferable. The molecular weight of the low molecular weight gelatin is 500-60,000, preferably 1,000-40,000. These low molecular weight gelatins may be used at the time of particle formation or dispersion after desalting, but are preferably used at the time of dispersion after desalting. Ordinary gelatin (molecular weight of about 100,000) may be used during grain formation, and low molecular weight gelatin may be used during dispersion after desalting. The concentration of the dispersion medium can be 0.05 to 20% by mass, but a concentration range of 5 to 15% by mass is preferable for handling. As the type of gelatin, alkali-treated gelatin is usually used, but modified gelatin such as acid-treated gelatin and phthalated gelatin can also be used.
[0070]
Sensitizing dyes that spectrally sensitize photosensitive silver halide grains are those that can spectrally sensitize silver halide grains in the desired wavelength range when adsorbed on silver halide grains, and are suitable for the spectral characteristics of the exposure light source. Sensitizing dyes having excellent spectral sensitivity can be advantageously selected. Regarding the sensitizing dye and the addition method, paragraphs 0103 to 0109 of JP-A No. 11-65021, compounds represented by formula (II) of JP-A No. 10-186572, and general formulas of JP-A No. 11-119374 Dye represented by formula (I) and paragraph No. 0106, U.S. Pat. Nos. 5,510,236 and 3,871,887, Example 5, JP-A-2-96131 And the dyes disclosed in Japanese Patent Application Laid-Open No. 59-48753. Also, European Patent Publication No. 0803764A1, page 19, line 38 to page 20, line 35, Japanese Patent Application No. 2000-86865. , Japanese Patent Application No. 2000-102560, Japanese Patent Application No. 2000-205399, and the like.
For example, examples of the dye that spectrally sensitizes a wavelength region of 550 nm to 750 nm include dyes represented by the formula (II) in JP-A-10-186572, specifically II-6, II-7, Illustrative examples of preferred dyes include II-14, II-15, II-18, II-23, and II-25. Examples of the dye that spectrally sensitizes a wavelength region of 750 to 1400 nm include a dye represented by the formula (I) in JP-A No. 11-119374, specifically, (25), (26), Examples of preferred pigments include (30), (32), (36), (37), (41), (49), and (54). Further, as a dye that forms J-band, the dye described in Example 5 of US Pat. No. 5,510,236 and US Pat. No. 3,871,887, JP-A-2-96131, The dye disclosed in JP-A-59-48753 can be exemplified as a preferred dye. These sensitizing dyes may be used alone or in combination of two or more.
[0071]
The time when the sensitizing dye is added to the photosensitive silver halide grains (emulsion) is preferably the time from the desalting step to the coating, more preferably from the desalting to the start of chemical ripening. The addition amount of the sensitizing dye can be set to a desired amount in accordance with the sensitivity and the fogging performance, but is 10 per mol of silver halide in the photosensitive layer.^-6~ 1 mol is preferred, more preferably 10^-Four-10^-1Is a mole.
[0072]
A supersensitizer can be used for the photosensitive silver halide grains (emulsion) in order to improve the spectral sensitization efficiency. Examples of supersensitizers include European Patent Publication No. 587,338, US Pat. Nos. 3,877,943, 4,873,184, JP-A-5-341432, 11-109547 gazette, 10-111543 gazette, etc. are mentioned.
[0073]
It is also preferred that the photosensitive silver halide grains (emulsion) are chemically sensitized by sulfur sensitization, selenium sensitization or tellurium sensitization. As compounds that are preferably used in the sulfur sensitization method, selenium sensitization method, and tellurium sensitization method, known compounds such as those described in JP-A-7-128768 can be used. In the present invention, tellurium sensitization is particularly preferred. The compounds described in the literature described in paragraph No. 0030 of JP-A-11-65021, and the formulas (II), (III), (IV in JP-A-5-313284 ) Is more preferred.
[0074]
Chemical sensitization of photosensitive silver halide grains can be performed at any time after grain formation and before coating. After desalting, (1) before spectral sensitization, (2) simultaneously with spectral sensitization, (3 ) After spectral sensitization, there may be (4) just before application. In particular, it is preferably performed after spectral sensitization. The amount of sulfur, selenium and tellurium sensitizers used in the present invention varies depending on the silver halide grains used, chemical ripening conditions, etc., but is 10 per mol of silver halide.^-8-10^-2Moles, preferably 10^-7-10^-3Use moles. The conditions for chemical sensitization in the present invention are not particularly limited, but the pH is 5 to 8, the pAg is 6 to 11, and the temperature is about 40 to 95 ° C.
[0075]
One kind of photosensitive silver halide grains (emulsion) may be used, or two or more kinds (for example, those having different average grain sizes, those having different halogen compositions, those having different crystal habits, and those having different chemical sensitization conditions) ) May be used together. The gradation can be adjusted by using a plurality of types of photosensitive silver halides having different sensitivities. As technologies relating to these, Japanese Patent Application Laid-Open Nos. 57-119341, 53-106125, 47-3929, 48-55730, 46-5187, 50-73627, 57-150841 etc. are mentioned. The sensitivity difference is preferably 0.2 log E or more for each emulsion.
[0076]
The amount of the photosensitive silver halide grains used is preferably 0.01 to 0.5 mol, more preferably 0.02 to 0.3 mol, and more preferably 0 to 1 mol per 1 mol of the organic silver salt. 0.03 mol to 0.25 mol is particularly preferred. Regarding the mixing method and mixing conditions of separately prepared photosensitive silver halide grains and reducible silver salts (organic silver salts), the silver halide grains and organic silver salts that have been prepared are respectively mixed with a high-speed stirrer, ball mill, A method of mixing with a sand mill, a colloid mill, a vibration mill, a homogenizer, etc., or a method of preparing an organic silver salt by mixing photosensitive silver halide prepared at any timing during the preparation of the organic silver salt, etc. However, there is no particular limitation as long as the effects of the present invention are sufficiently obtained. Moreover, mixing two or more organic silver salt aqueous dispersions and two or more photosensitive silver salt aqueous dispersions when mixing is a preferred method for adjusting photographic characteristics.
[0077]
Next, a reducible silver salt (hereinafter sometimes referred to as a non-photosensitive silver salt) will be described.
The reducible silver salt is preferably an organic silver salt, which is relatively stable to light, but the presence of an exposed photocatalyst (such as a latent image of a photosensitive silver halide) and a reducing agent. Below is a silver salt that forms a silver image when heated to 80 ° C. or higher. The organic silver salt may be any organic material that contains a reducible source of silver ions. Silver salts of organic acids, particularly silver salts of long-chain aliphatic carboxylic acids (having 10 to 30, preferably 15 to 28 carbon atoms) are preferred. Also preferred are organic or inorganic silver salt complexes in which the ligand has a complex stability constant in the range of 4.0 to 10.0. The silver-providing substance can preferably constitute about 5 to 70% by weight of the image forming layer. Preferable organic silver salts include silver salts of organic compounds having a carboxyl group. Specific examples include, but are not limited to, silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the aliphatic carboxylic acid silver salt include silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate and fumarate. Examples thereof include silver oxide, silver tartrate, silver linoleate, silver butyrate and silver camphorate, and mixtures thereof.
[0078]
Among these organic acid silver or a mixture of organic acid silver, it is preferable to use organic acid silver having a silver behenate content of 75 mol% or more, and using organic acid silver having a silver behenate content of 85 mol% or more. Further preferred. Here, the silver behenate content indicates the molar fraction of silver behenate relative to the organic acid silver used. As the organic acid silver other than the silver behenate contained in the organic acid silver used in the present invention, the above exemplified organic acid silver can be preferably used.
[0079]
The organic acid silver is particularly preferably prepared by reacting a solution or suspension of an alkali metal salt of the above organic acid (including Na salt, K salt, Li salt and the like) with silver nitrate. Regarding these preparation methods, the method described in paragraph Nos. 0019 to 0021 of Japanese Patent Application No. 11-104187 and the method described in European Patent Publication No. 09681212A1 can be used. In the present invention, a method of preparing organic acid silver by adding a silver nitrate aqueous solution and an organic acid alkali metal salt solution into a sealing means for mixing liquid (mixing means having no gas-liquid interface) is preferably used. be able to. Specifically, the methods described in Japanese Patent Application Nos. 11-203413 and 2000-195621 can be used.
[0080]
During the preparation of the organic acid silver, a water-soluble dispersant can be added to the aqueous silver nitrate solution and the organic acid alkali metal salt solution, or the reaction solution. Specific examples of the type and amount of the dispersant used here are described in paragraph No. 0052 of Japanese Patent Application No. 11-115457.
[0081]
The organic acid silver is preferably prepared in the presence of a tertiary alcohol. The tertiary alcohol is preferably a compound having a total carbon number of 15 or less, and particularly preferably a compound having 10 or less. Examples of preferred tertiary alcohols include tert-butanol, but the tertiary alcohol that can be used in the present invention is not limited thereto. The third alcohol may be added at any time during the preparation of the organic acid silver, but it is preferably added during the preparation of the organic acid alkali metal salt to dissolve and use the organic acid alkali metal salt. Further, the tertiary alcohol used in the present invention can be used in a mass ratio of 0.01 to 10 with respect to water as a solvent at the time of preparing the organic acid silver, but in a range of 0.03 to 1. It is preferable to use it.
[0082]
The shape and size of the organic silver salt are not particularly limited, but those described in paragraph No. 0024 of Japanese Patent Application No. 11-104187 and those described in European Patent Publication No. 09681212A1 are preferably used. The shape of the organic silver salt can be determined from a transmission electron microscope image of the organic silver salt dispersion. Another method for measuring the monodispersity of the grain size is to obtain the standard deviation of the volume weighted average diameter of the organic silver salt, and the percentage (variation coefficient) of the value divided by the volume weighted average diameter is preferably 80%. Below, more preferably 50% or less, and still more preferably 30% or less. 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 temporal change of fluctuation of the scattered light is obtained. be able to. The average particle size in this measurement method is preferably a solid fine particle dispersion of 0.05 μm to 10.0 μm. A more preferable average particle size is 0.1 μm to 5.0 μm, and a further preferable average particle size is 0.1 μm to 2.0 μm.
[0083]
The organic silver salt is preferably desalted. The desalting method is not particularly limited, and a known method can be used, but a known filtration method such as centrifugal filtration, suction filtration, ultrafiltration, and flock-forming water washing by an agglomeration method can be preferably used. As for the ultrafiltration method, the methods described in Japanese Patent Application No. 11-115457 and Japanese Patent Application 2000-90093 can be used. In the present invention, for the purpose of obtaining an organic silver salt solid dispersion having a high S / N, a small particle size, and no aggregation, the organic silver salt as an image forming medium is contained, and the photosensitive silver salt is substantially contained. It is preferable to use a dispersion method in which a pressure drop is performed after converting a non-aqueous dispersion into a high-speed flow. As for these dispersing methods, the methods described in paragraph Nos. 0027 to 0038 of Japanese Patent Application No. 11-104187 can be used.
[0084]
The particle size distribution of the organic silver salt solid fine particle dispersion is preferably monodispersed. Specifically, the percentage (coefficient of variation) of the value obtained by dividing the standard deviation of the volume load average diameter by the volume load average diameter is 80% or less, more preferably 50% or less, and even more preferably 30% or less. Such an organic silver salt solid fine particle dispersion is composed of at least an organic silver salt and water. The ratio of the organic silver salt to water is not particularly limited, but the ratio of the organic silver salt to the entire organic silver salt is preferably 5 to 50% by mass, particularly preferably 10 to 30% by mass. It is preferable to use the above-mentioned dispersion aid, but it is preferable to use the minimum amount in a range suitable for minimizing the particle size, and 0.5 to 30% by weight, particularly 1 to 15%, based on the organic silver salt. A range of mass% is preferred. The organic silver salt can be used in a desired amount, but the silver amount is 0.1 to 5 g / m.²Is more preferable, and more preferably 1 to 3 g / m.²It is.
[0085]
Next, the binder will be described.
The binder is used for the image forming layer (photosensitive layer, emulsion layer) on the same surface as the photosensitive silver halide and the reducible silver salt on the support. Specifically, the binder is well known. Any natural or synthetic resin such as gelatin, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, cellulose acetate, polyolefin, polyester, polystyrene, polyacrylonitrile, polycarbonate and the like can be selected. Of course, copolymers and terpolymers are also included. Preferred polymers are polyvinyl butyral, butyl ethyl cellulose, methacrylate copolymers, maleic anhydride ester copolymers, polystyrene and butadiene styrene copolymers. If necessary, two or more of these polymers can be used in combination. Such polymers are used in an amount sufficient to retain the components therein. That is, it is used in an effective range to function as a binder. The effective range can be appropriately determined by those skilled in the art. As a guideline for holding at least the organic silver salt, the ratio of the binder to the organic silver salt is preferably in the range of 15: 1 to 1: 2, particularly 8: 1 to 1: 1.
[0086]
In the present invention, at least one of the image forming layers preferably contains a polymer latex described below as a binder in an amount of 50% by mass or more based on the total binder. (Hereinafter, this image forming layer is referred to as “image forming layer in the present invention”, and the polymer latex used in the binder is referred to as “polymer latex used in the present invention”.) The polymer latex is not only the image forming layer, but also a protective layer and a back layer. When the photothermographic material of the present invention is used for printing applications in which dimensional change is a problem, it is necessary to use a polymer latex for the protective layer and the back layer. However, the “polymer latex” mentioned here is a water-insoluble hydrophobic polymer dispersed as fine particles in a water-soluble dispersion medium. As the dispersion state, the polymer is emulsified in a dispersion medium, the emulsion is polymerized, the micelle is dispersed, or the polymer molecule has a partially hydrophilic structure and the molecular chain itself is molecularly dispersed. Anything may be used. As for the polymer latex used in the present invention, “Synthetic resin emulsion (Hiraku Okuda, Hiroshi Inagaki, published by Kobunshi Publishing Co., Ltd. (1978))”, “Application of synthetic latex (Takaaki Sugimura, Ikuo Kataoka, Junichi Suzuki, Keiji Kasahara) , Published by Polymer Press Association (1993)), “Synthetic Latex Chemistry (written by Soichi Muroi, published by Polymer Press Association (1970))”, and the like. The average particle size of the dispersed particles is preferably 1 to 50000 nm, more preferably about 5 to 1000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution.
[0087]
The polymer latex used in the present invention may be a so-called core / shell type latex in addition to a normal polymer latex having a uniform structure. In this case, it may be preferable to change the glass transition temperature between the core and the shell. The preferred range of the glass transition temperature (Tg) of the polymer latex polymer used in the present invention differs between the protective layer, the back layer and the image forming layer. In the image forming layer, it is 40 ° C. or less, preferably 20 to 40 ° C., more preferably 23 to 40 ° C., and further preferably 30 to 40 ° C. in order to promote diffusion of photographic useful materials during heat development. When used for a protective layer or a back layer, a glass transition temperature of 25 to 70 ° C. is preferable for contact with various devices.
[0088]
The minimum film-forming temperature (MFT) of the polymer latex used in the present invention is preferably −30 ° C. to 90 ° C., more preferably about 0 ° C. to 70 ° C. A film-forming auxiliary may be added to control the minimum film-forming temperature. A film-forming aid, also called a plasticizer, is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of a polymer latex. For example, “Synthetic Latex Chemistry (Souichi Muroi, published by Kobunshi Shuppankai (1970)” )"It is described in. Examples of the polymer species used in the polymer latex include acrylic resins, vinyl acetate resins, polyester resins, polyurethane resins, rubber resins, vinyl chloride resins, vinylidene chloride resins, polyolefin resins, and copolymers thereof. The polymer may be a linear polymer, a branched polymer, or a crosslinked polymer. The polymer may be a so-called homopolymer in which a single monomer is polymerized or a copolymer in which two or more monomers are polymerized. In the case of a copolymer, it may be a random copolymer or a block copolymer. The molecular weight of the polymer is a number average molecular weight of 5,000 to 1,000,000, preferably about 10,000 to 100,000. When the molecular weight is too small, the mechanical strength of the image forming layer is insufficient, and when the molecular weight is too large, the film forming property is poor, which is not preferable.
[0089]
Specific examples of the polymer latex used as the binder of the image forming layer in the invention include the following. Latex of methyl methacrylate / ethyl acrylate / methacrylic acid copolymer, latex of methyl methacrylate / 2-ethylhexyl acrylate / styrene / acrylic acid copolymer, latex of styrene / butadiene / acrylic acid copolymer, latex of styrene / butadiene / divinylbenzene / methacrylic acid copolymer , Latex of methyl methacrylate / vinyl chloride / acrylic acid copolymer, latex of vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer, and the like. Moreover, such a polymer is also marketed and the following polymers can be utilized. For example, as an example of an acrylic resin, as a polyester resin such as Sebian A4635, 46583, 4601 (manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 820, 857 (manufactured by Nippon Zeon Co., Ltd.), FINETEX ES650, 611, 675, 850 (manufactured by Dainippon Ink Chemical Co., Ltd.), WD size, WMS (manufactured by Eastman Chemical Co., Ltd.), etc. Chemicals) and other rubber-based resins such as LACSTAR 7310K, 3307B, 4700H, 7132C (manufactured by Dainippon Ink and Chemicals), Nipol Lx416, 410, 438C, 2507 (manufactured by Nippon Zeon Co., Ltd.), etc. , With vinyl chloride resin G351, G576 (Nippon Zeon Co., Ltd.) and other vinylidene chloride resins such as L502, L513 (Asahi Kasei Kogyo Co., Ltd.), Aron D7020, D504, D5071 (Mitsui Toatsu Co., Ltd.) As the olefin resin, Chemipearl S120, SA100 (manufactured by Mitsui Petrochemical Co., Ltd.) and the like can be mentioned. These polymers may be used alone or in combination of two or more as required.
[0090]
In the image forming layer of the present invention, it is preferable to use the polymer latex as 50% by mass or more of the total binder, but it is more preferable to use the polymer latex as 70% by mass or more.
The total binder amount of the image forming layer in the present invention is 0.2 to 30 g / m.², More preferably 1 to 15 g / m²The range of is preferable. A crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added to the image forming layer.
[0091]
A hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, hydroxypropylmethylcellulose or the like may be added to the image forming layer in the present invention as required within a range of 50% by mass or less of the total binder. . The addition amount of these hydrophilic polymers is preferably 30% by mass or less, more preferably 15% by mass or less, based on the total binder of the image forming layer.
[0092]
The image forming layer in the invention is preferably prepared by applying an aqueous coating solution and then drying it. However, “aqueous” as used herein means that 60% by mass or more of the solvent (dispersion medium) of the coating solution is water. As components other than water in the coating solution, water-miscible organic solvents such as methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve, ethyl cellosolve, dimethylformamide, and ethyl acetate can be used. Specific examples of the solvent composition include the following in addition to water. Water / methanol = 90/10, water / methanol = 70/30, water / ethanol = 90/10, water / isopropanol = 90/10, water / dimethylformamide = 95/5, water / methanol / dimethylformamide = 80 / 15/5, water / methanol / dimethylformamide = 90/5/5. (However, the numbers represent mass%.)
[0093]
Next, the support will be described.
Various supports can be used as the support. Typical supports include polyester film, primed polyester film, poly (ethylene terephthalate) film, polyethylene naphthalate film, cellulose nitrate film, cellulose ester film, poly (vinyl acetal) film, polycarbonate film and related or resinous And glass, paper, metal and the like. Coated with a flexible substrate, in particular a baryta and / or a partially acetylated alpha-olefin polymer, in particular a polymer of alpha-olefins having 2 to 10 carbon atoms such as polyethylene, polypropylene, ethylene-butene copolymers. A paper support is typically used. Such a support may be transparent or opaque, but is preferably transparent. Of these, biaxially stretched polyethylene terephthalate (PET) of about 75 to 200 μm is particularly preferable.
[0094]
In general, when a plastic film is passed through a heat developing machine for processing at 80 ° C. or higher, the dimensions of the film generally expand and contract. When the processed material is used for printing plate making, this expansion / contraction becomes a serious problem when performing precision multicolor printing. Therefore, in the present invention, it is preferable to use a film having a small dimensional change, which is devised to alleviate internal strain remaining in the film during biaxial stretching and to eliminate heat shrinkage strain generated during heat development. For example, polyethylene terephthalate that has been heat-treated at a temperature in the range of 100 ° C. to 210 ° C. before coating a light-sensitive silver halide emulsion (emulsion for heat development photography) is preferably used. Those having a high glass transition temperature are also preferred, and polyether ethyl ketone, polystyrene, polysulfone, polyethersulfone, polyarylate, polycarbonate and the like can be used.
[0095]
In the case of a photothermographic material for medical use, the transparent support may be colored with a blue dye (for example, dye-1 described in Examples of JP-A-8-240877), or may be uncolored. Examples of the support include a water-soluble polyester disclosed in JP-A-11-84574, a styrene-butadiene copolymer disclosed in JP-A-10-186565, and a vinylidene chloride copolymer described in Japanese Patent Application No. 11-106881, paragraph numbers 0063 to 0080. It is preferable to apply an undercoating technique such as. In addition, regarding the antistatic layer or the undercoat, paragraph numbers 0040 to of JP-A-56-143430, JP-A-56-143431, JP-A-58-62646, JP-A-56-120519, JP-A-11-84573. The techniques described in paragraph numbers 0078 to 0084 of 0051, US Pat. No. 5,575,957 and JP-A-11-223898 can be applied.
[0096]
Next, other additives and layer structures will be described.
In the photothermographic material of the present invention, the photosensitive silver halide and / or the reducible silver salt are further protected against the formation of additional fog by known antifoggants and stabilizer precursors, and are in stock. It can be stabilized against a decrease in sensitivity during storage. Suitable antifoggants, stabilizers and stabilizer precursors that can be used alone or in combination are the thiazonium described in US Pat. Nos. 2,131,038 and 2,694,716. Salt, azaindene described in U.S. Pat. Nos. 2,886,437 and 2,444,605, mercury salt described in U.S. Pat. No. 2,728,663, U.S. Pat. , 287,135, sulfocatechol described in US Pat. No. 3,235,652, oxime described in British Patent 623,448, nitrone, nitroindazole, US patent No. 2,839,405, polyvalent metal salts, U.S. Pat. No. 3,220,839, thulonium salts, and U.S. Pat. No. 2,5. Palladium, platinum and gold salts described in US Pat. Nos. 6,263 and 2,597,915, US Pat. Nos. 4,108,665 and 4,442,202 Halogen-substituted organic compounds described, U.S. Pat. Nos. 4,128,557 and 4,137,079, 4,138,365 and 4,459,350 And the phosphorus compounds described in US Pat. No. 4,411,985.
[0097]
The antifoggant is preferably an organic halide. For example, JP-A-50-119624, JP-A-50-120328, JP-A-51-121332, JP-A-54-58022, and JP-A-56-70543. 56-99335, 59-90842, 61-129642, 62-129845, JP-A-6-208191, 7-5621, 7-2781 , U.S. Pat. Nos. 8,15,809, 5,340,712, 5,369,000, and 5,464,737. Is mentioned. Among these, the organic polyhalogen compound represented by the following general formula (4) is particularly preferable.
[0098]
Formula (4) Q²-(Y)_n-CZ¹Z²X
[0099]
In general formula (4), Q²Represents an alkyl group, an aryl group or a heterocyclic group which may have a substituent.
Q²The alkyl group represented by is a linear, branched, cyclic or a combination thereof, preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, still more preferably 1 to 6 carbon atoms. Examples include methyl, ethyl, allyl, n-propyl, isopropyl, sec-butyl, isobutyl, t-butyl, sec-pentyl, isopentyl, t-pentyl, t-octyl, 1-methylcyclohexyl and the like. A tertiary alkyl group is preferred.
Q²The alkyl group represented by the above formula may have a substituent, and the substituent may be any group as long as it does not adversely affect photographic performance. For example, a halogen atom (fluorine atom, Chlorine atom, bromine atom or iodine atom), alkyl group, alkenyl group, alkynyl group, aryl group, heterocyclic group (including N-substituted nitrogen-containing heterocyclic group, for example, morpholino group), alkoxycarbonyl group, aryloxy Carbonyl group, carbamoyl group, imino group, imino group substituted with N atom, thiocarbonyl group, carbazoyl group, cyano group, thiocarbamoyl group, alkoxy group, aryloxy group, heterocyclic oxy group, acyloxy group, (alkoxy or aryl Oxy) carbonyloxy group, sulfonyloxy group, acylamide group, sulfonamide Ureido group, thioureido group, imide group, (alkoxy or aryloxy) carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, (alkyl or aryl) sulfonylureido group, nitro group, (alkyl or aryl) Examples include a sulfonyl group, a sulfamoyl group, a group containing a phosphoric acid amide or phosphate ester structure, a silyl group, a carboxyl group or a salt thereof, a sulfo group or a salt thereof, a phosphoric acid group, a hydroxy group, a quaternary ammonium group, and the like. These substituents may be further substituted with these substituents.
Q²Is a monocyclic or condensed ring aryl group, preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, still more preferably 6 to 10 carbon atoms, and is preferably a phenyl group or a naphthyl group.
Q²The aryl group represented by the above formula may have a substituent, and the substituent may be any group as long as it does not adversely affect the photographic performance. The same group is mentioned.
Q²Is a 5- to 7-membered saturated or unsaturated monocyclic or condensed ring containing one or more heteroatoms selected from the group consisting of nitrogen, oxygen and sulfur atoms. Is preferred. Examples of heterocycles are preferably pyridine, quinoline, isoquinoline, pyrimidine, pyrazine, pyridazine, phthalazine, triazine, furan, thiophene, pyrrole, oxazole, benzoxazole, thiazole, benzothiazole, imidazole, benzimidazole, thiadiazole, triazole, etc. More preferred are pyridine, quinoline, pyrimidine, thiadiazole, and benzothiazole, and particularly preferred are pyridine, quinoline, and pyrimidine.
Q²The heterocyclic group represented by may have a substituent.
[0100]
In general formula (4), Q²Is preferably a phenyl group, a naphthyl group, a quinolyl group, a pyridyl group, a pyrimidyl group, a thiadiazolyl group, or a benzothiazolyl group, and particularly preferably a phenyl group, a naphthyl group, a quinolyl group, a pyridyl group, or a pyrimidyl group.
Q²May have a ballast group used in a photographic material to reduce diffusibility, a group adsorbing to a silver salt or a group imparting water solubility, or may be polymerized with each other to form a polymer. They may be formed, or substituents may be bonded to form a bis type, tris type, or tetrakis type.
[0101]
In the general formula (4), Y represents a divalent linking group, preferably —SO₂-, -SO-, -CO-, particularly preferably -SO.₂-.
In the general formula (4), n represents 0 or 1, but is preferably 1.
In general formula (4), Z¹And Z²Each independently represents a halogen atom (eg, fluorine, chlorine, bromine, iodine, etc.), but Z¹And Z²Most preferably, both are bromine atoms.
[0102]
In General formula (4), X represents a hydrogen atom or an electron withdrawing group. The electron withdrawing group represented by X is a substituent whose Hammett's substituent constant δp can take a positive value, specifically, a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, A sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, a halogen atom, an acyl group, a heterocyclic group and the like can be mentioned. X is preferably a hydrogen atom or a halogen atom, and most preferably a bromine atom.
[0103]
Examples of the organic polyhalogen compound represented by the general formula (4) include US Pat. Nos. 3,874,946, 4,756,999, and 5,340,712. 5,369,000, 5,464,737, JP-A-50-137126, 50-89020, 50-119624, 59-57234. No. 7, JP-A-7-2781, JP-A-7-5621, JP-A-9-160164, JP-A-10-197988, JP-A-9-244177, JP-A-9-244178, JP-A-9-160167. Publication No. 9-319022 Publication No. 9-258367 Publication No. 9-265150 Publication No. 9-319022 Publication No. 10-197989 Publication No. 11-2423 No. 4 publication, Japanese Patent Application Nos. 10-181459, 10-292864, 11-90095, 11-89773, 11-205330, etc. Compounds.
[0104]
The organic polyhalogen compound represented by the general formula (4) may be used alone or in combination of two or more. The amount used is 1 m of photothermographic material.²As a coating amount per unit, 1 × 10^-6~ 1x10^-2mol / m²Is preferred, more preferably 1 × 10^-Five~ 5x10^-3mol / m²And more preferably 2 × 10^-Five~ 1x10^-3mol / m²It is.
[0105]
The organic polyhalogen compound represented by the general formula (4) may be added to any layer on the support as long as it is the same surface as the photosensitive silver halide and the reducible silver salt. It is preferable to add to a layer containing silver or a layer adjacent thereto.
[0106]
The organic polyhalogen compound represented by the general formula (4) is water or an appropriate organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol, etc.), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.) , Dimethylformamide, dimethyl sulfoxide, methyl cellosolve and the like. Alternatively, according to the well-known emulsification dispersion method, dissolve using an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically emulsify and disperse. An object can be made and used. Alternatively, a powder of an organic polyhalogen compound can be dispersed in water by a ball mill, a colloid mill, a sand grinder mill, a manton gourin, a microfluidizer or an ultrasonic wave according to a well-known solid dispersion method. .
[0107]
Although the preferable example of the organic polyhalogen compound represented by Formula (4) below is given, the organic polyhalogen compound used for this invention is not limited to these.
[0108]
Embedded image
[0109]
Embedded image
[0110]
Embedded image
[0111]
Embedded image
[0112]
Although not necessary for practicing the present invention, it may be advantageous to add mercury (II) salt as an antifoggant to the emulsion layer. Preferred mercury (II) salts for this purpose are mercury acetate and mercury bromide.
[0113]
Furthermore, you may contain benzoic acids for the purpose of high sensitivity and fog prevention. The benzoic acid used in the present invention may be any benzoic acid derivative. Examples of preferred structures include U.S. Pat. Nos. 4,784,939, 4,152,160, and And the compounds described in JP-A-9-329864, JP-A-9-329864, JP-A-9-281638, and the like.
The amount of benzoic acid added may be any amount, but it is preferably 1 mmol to 2 mol, more preferably 1 mmol to 0.5 mol, per mol of silver. The benzoic acid may be added by any method such as powder, solution, fine particle dispersion and the like. Moreover, you may add as a solution mixed with other additives, such as a sensitizing dye, a reducing agent, and a color toning agent. The benzoic acid can be added at any step during the preparation of the coating solution, and when added to the organic silver salt-containing layer, any step from the preparation of the organic silver salt to the preparation of the coating solution can be performed. Immediately before is preferable. Benzoic acids may be added to any part of the photothermographic material, but are preferably added to the layer having the photosensitive layer as the image forming layer, and more preferably to the organic silver salt-containing layer.
[0114]
In the photothermographic material of the present invention, a compound called a “coloring agent” is added to the photosensitive material as necessary for the purpose of improving the image density (image density), silver color tone and heat developability of the silver image. be able to.
In particular, a wide range of toning agents can be used in the photothermographic material of the present invention using an organic silver salt. For example, JP-A-46-6077, 47-10282, 49-5019, 49-5020, 49-91215, 49-91215, 50-2524 Gazette, 50-32927 gazette, 50-67132 gazette, 50-67641 gazette, 50-114217 gazette, 51-3223 gazette, 51-27923 gazette, 52-14788 gazette. JP, 52-99813, 53-1020, 53-76020, 54-156524, 54-156525, 61-183642, JP-A-4-56848. Gazette, Japanese Patent Publication Nos. 49-10727, 54-20333, U.S. Pat. No. 3,080,254, 3,446, No. 48, No. 3,782,941, No. 4,123,282, No. 4,510,236, British Patent No. 1,380,795, This is disclosed in Belgian Patent No. 841,910, Japanese Patent Publication No. 1-25050, and the like.
[0115]
These toning agents have the required performance (image density, silver tone, improved thermal development), characteristics such as volatility to the outside of photosensitive materials, sublimation properties, and sensitivity when combined with other additives such as antifoggants. Searches are proceeding from the standpoint of material properties and many colorants have been reported. Among them, it is known that the combination of phthalazines and phthalic acid derivatives is excellent.
Preferable examples of the phthalazine compound and the production method thereof include JP-A-10-339928, JP-A-10-339930, JP-A-10-339931, JP-A-10-332234, JP-A-11-52511, and 13-2660. No. 13-19679 and the like.
The amount of phthalazine compound used is 10 per mole of silver.^-Four˜1 mol, more preferably 10^-3~ 0.3 mol, more preferably 10^-Four~ 0.3 mol.
The phthalazine compound may be added by any method such as a solution, a powder, a solid fine particle dispersion, an emulsion, or an oil protect dispersion. The solid fine particle dispersion is performed by a known finer means (for example, ball mill, vibration ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). A dispersion aid may be used when dispersing the solid fine particles.
The phthalazine compound may be added to any layer on the support as long as it is the same surface as the photosensitive silver halide and reducible silver salt, but it is added to the layer containing silver halide or a layer adjacent thereto. It is preferable to do.
[0116]
In the photothermographic material of the present invention, a base generally required for processing a photographic light-sensitive material can be supplied by various base supply methods. For example, when a base generating function is given to the photosensitive material side, it can be introduced into the photosensitive material as a base precursor. Examples of such base precursors include salts of organic acids and bases that are decarboxylated by heat, compounds that release amines by intramolecular nucleophilic substitution reaction, Rossen rearrangement or Beckmann rearrangement, and the like. This example is described in US Pat. Nos. 4,514,493 and 4,657,848.
[0117]
In the photothermographic material of the invention, it is preferable to use an ultrahigh contrast agent. The type of the super-high contrast agent used in the present invention is not particularly limited, but as a preferable super-high contrast agent, a hydrazine derivative represented by the formula (H) described in Japanese Patent Application No. 11-87297 (specifically, Hydrazine derivatives listed in Tables 1 to 4 of the same specification), JP-A-10-10672, JP-A-10-161270, JP-A-10-62898, JP-A-9-304870, JP-A-9 All hydrazine derivatives described in JP-A-9-304872, JP-A-9-304871, JP-A-10-31282, US Pat. No. 5,496,695, European Patent Publication 741,320 Can be mentioned.
Further, substituted alkene derivatives, substituted isoxazole derivatives and specific acetal compounds represented by the general formulas (1) to (3) described in JP-A No. 2000-284399, more preferably the formula (A) described in the same specification Alternatively, a cyclic compound represented by the formula (B), specifically, compounds 1 to 72 described in chemical formulas 8 to 12 of the same specification can also be used. Further, a plurality of these ultrahigh contrast agents may be used in combination.
[0118]
Ultra-high contrast agent is dissolved in water or an appropriate organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethyl sulfoxide, methyl cellosolve, etc. Can be used.
In addition, it is dissolved by using a well-known emulsification dispersion method using an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically emulsified dispersion. Can be used. Alternatively, the ultra-high contrast agent powder may be dispersed in an appropriate solvent such as water by a ball mill, a colloid mill, or ultrasonic waves by a method known as a solid dispersion method.
The ultrahigh contrast agent may be added to any layer on the image forming layer side with respect to the support, but is preferably added to the image forming layer or a layer adjacent thereto.
The amount of super-hardening agent added is 1 x 10 per mole of silver^-6~ 1 mole is preferred, 1 × 10^-Five~ 5x10^-1Mole is more preferred, 2 × 10^-Five~ 2x10^-1Mole is most preferred.
[0119]
As the ultra-high contrast agent, in addition to the above-mentioned compounds, US Pat. Nos. 5,545,515, 5,635,339, 5,654,130, International Publication WO 97 No. 34,196, U.S. Pat. No. 5,686,228, or JP-A-11-119372, JP-A-11-133546, JP-A-11-119373, JP-A-11 The compounds described in JP-A-1095546, JP-A-11-95365, JP-A-11-95366, and JP-A-11-149136 may be used.
[0120]
In the photothermographic material of the present invention, for the formation of a super high contrast image, a high contrast accelerator can be used in combination with the super high contrast agent. For example, amine compounds described in US Pat. No. 5,545,505, specifically AM-1 to AM-5, hydroxamic acids described in US Pat. No. 5,545,507, specific examples HA-1 to HA-11, acrylonitriles described in US Pat. No. 5,545,507, specifically CN-1 to CN-13, US Pat. No. 5,558,983 Hydrazine compounds, specifically CA-1 to CA-6, Onum salts described in JP-A-9-297368, specifically A-1 to A-42, B-1 to B -27, C-1 to C-14, and the like can be used.
[0121]
In the photothermographic material of the present invention, formic acid or formate is a strong fogging substance. In the present invention, the content of formic acid or formate on the side having the image forming layer containing the photosensitive silver halide of the photothermographic material is preferably 5 mmol or less, more preferably 1 mmol or less per mol of silver. .
[0122]
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 with an ultrahigh contrast agent. Acids or salts thereof formed by hydration of diphosphorus pentoxide include metaphosphoric acid (salt), pyrophosphoric acid (salt), orthophosphoric acid (salt), triphosphoric acid (salt), tetraphosphoric acid (salt), hexametalin An acid (salt) etc. can be mentioned. Examples of the acid or salt thereof formed by hydrating diphosphorus pentoxide particularly preferably include orthophosphoric acid (salt) and hexametaphosphoric acid (salt). Specific examples of the salt include sodium orthophosphate, sodium dihydrogen orthophosphate, sodium hexametaphosphate, and ammonium hexametaphosphate.
The acid formed by hydration of diphosphorus pentoxide or a salt thereof is preferably added to the image forming layer or the binder layer adjacent to the image forming layer from the viewpoint that a desired effect is exhibited in a small amount.
Amount of acid or salt thereof formed by hydration of diphosphorus pentoxide (1m photosensitive material)²The coating amount per unit) may be a desired amount according to the performance such as sensitivity and fog, but 0.1 to 500 mg / m²Is preferably 0.5 to 100 mg / m²Is more preferable.
[0123]
The photothermographic material of the present invention includes a mercapto compound, a disulfide for the purpose of controlling development by suppressing or accelerating development, improving spectral sensitization efficiency, and improving storage stability before and after development. A compound and a thione compound can be contained.
When a mercapto compound is used, it may have any structure, but Ar-SM⁰And those represented by Ar—S—S—Ar are preferred. Where M⁰Is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring group or condensed aromatic ring group having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably, the heteroaromatic ring is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotelrazole, carbazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine , Pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone.
The heteroaromatic ring may have a substituent. Examples of the substituent include halogen (for example, bromine and chlorine), hydroxy, amino, carboxy, and alkyl (for example, one or more carbon atoms, preferably the number of carbon atoms). 1-4), alkoxy (for example, having 1 or more carbon atoms, preferably 1 to 4 carbon atoms), and aryl (which may have a substituent). Examples of mercapto-substituted heteroaromatic compounds include 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole, 6-ethoxy-2-mercaptobenzothiazole, 2 , 2-dithiobisbenzothiazole, 3-mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2-mercaptoquinoline 8-mercaptopurine, 2-mercapto-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol, 2,3,5,6-tetrachloro-4-pyridinethiol, 4-amino-6- Hydroxy-2-mercapto-pi Midine monohydrate, 2-amino-5-mercapto-1,3,4-thiadiazole, 3-amino-5-mercapto-1,2,4-triazole, 4-hydroxy-2-mercaptopyrimidine, 2-mercaptopyrimidine 4,6-diamino-2-mercaptopyrimidine, 2-mercapto-4-methylpyrimidine hydrochloride, 3-mercapto-5-phenyl-1,2,4-triazole, 1-phenyl-5-mercaptotetrazole, 3- (5-mercaptotetrazole) sodium benzenesulfonate, N-methyl-N- [3- (5-mercaptotetrazolyl) phenyl] urea, 2-mercapto-4-phenyloxazole, N- [3- (mercaptoacetylamino) ) Propyl] carbazole and the like. But it is not limited.
The addition amount of the mercapto compound is preferably in the range of 0.0001 to 1 mol per mol of silver in the image forming layer, and more preferably 0.001 to 0.3 mol per mol of silver.
[0124]
In the photothermographic material of the present invention, the image forming layer (photosensitive layer) has, as a plasticizer and a lubricant, a polyhydric alcohol (for example, the type described in US Pat. No. 2,960,404). Glycerin and diol), fatty acids or esters described in US Pat. Nos. 2,588,765 and 3,121,060, silicone resins described in British Patent 955,061, and the like. Can be used.
[0125]
In the photothermographic material of the invention, various dyes and pigments can be used in the image forming layer from the viewpoint of improving the color tone and preventing irradiation. Any of these dyes and pigments may be used. For example, pigments and dyes described in the color index are used. Specifically, pyrazoloazole dyes, anthraquinone dyes, azo dyes, azomethine dyes, oxonol dyes, carbocyanine dyes, styryls. Examples thereof include organic pigments such as dyes, triphenylmethane dyes, indoaniline dyes, indophenol dyes, phthalocyanines, and inorganic pigments. Preferable dyes include anthraquinone dyes (for example, compounds 1 to 9 described in JP-A-5-341441, compounds 3-6 to 18 and 3-23 to 38 described in JP-A-5-165147), azomethine dyes ( Compounds 17 to 47 described in JP-A-5-341441), indoaniline dyes (for example, compounds 11 to 19 described in JP-A-5-289227, compound 47 described in JP-A-5-341441, and JP-A-5 And compounds 2-10 to 11 described in JP-A No. 165147) and azo dyes (compounds 10 to 16 described in JP-A No. 5-341441).
The amount of dye and pigment used is determined by the desired amount of absorption, but generally 1 m of photosensitive material.²A range of 1 mg to 1 g per unit is preferred. As a method for adding the dye, any method such as a solution, an emulsion, a solid fine particle dispersion, or a state mordanted in a polymer mordant may be used.
[0126]
In the photothermographic material of the present invention, a surface protective layer can be provided for the purpose of preventing adhesion of the image forming layer.
The binder for the surface protective layer may be any polymer, but the polymer having a carboxylic acid residue is 100 mg / m.²~ 5g / m²It is preferable to include. Examples of the polymer having a carboxylic acid residue include natural polymers (gelatin, alginic acid, etc.), modified natural polymers (carboxymethylcellulose, phthalated gelatin, etc.), synthetic polymers (polymethacrylate, polyacrylate, polyalkylmethacrylate). / Acrylate copolymer, polystyrene / polymethacrylate copolymer, etc.). The content of the carboxy residue in such a polymer is preferably 10 mmol to 1.4 mol per 100 g of the polymer. In addition, the carboxylic acid residue may form a salt with an alkali metal ion, an alkaline earth metal ion, an organic cation or the like.
Any adhesion preventing material may be used for the surface protective layer. Examples of anti-adhesive materials include wax, silica particles, styrene-containing elastomeric block copolymers (eg, styrene-butadiene-styrene, styrene-isoprene-styrene), cellulose acetate, cellulose acetate butyrate, cellulose propionate, and these A mixture etc. are mentioned. In addition, a crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added to the surface protective layer.
[0127]
In the photothermographic material of the present invention, the image forming layer or the protective layer of the image forming layer may be formed of U.S. Pat. Nos. 3,253,921, 2,274,782, and 2,527. , 583 and 2,956,879, and light absorbing materials and filter dyes can be used. For example, a dye can be mordanted as described in US Pat. No. 3,282,699. As for the usage-amount of filter dye, 0.1-3 are preferable for the light absorbency in exposure wavelength, and 0.2-1.5 are especially preferable.
[0128]
In the photothermographic material of the present invention, the photosensitive layer or the non-photosensitive layer adjacent thereto is coated with various dyes and pigments (for example, CI and CI) from the viewpoints of color tone improvement, prevention of interference fringe generation during laser exposure, and prevention of irradiation. CI Pigment Blue 60, CI Pigment Blue 64, CI Pigment Blue 15: 6) can be used. These are described in detail in International Publication WO98 / 36322, JP-A-10-268465, 11-338098 and the like.
[0129]
The photothermographic material of the present invention has a photosensitive layer (preferably an image forming layer) containing at least one photosensitive silver halide emulsion on one side of a support and a back layer on the other side. A so-called single-sided photosensitive material is preferable.
The back layer preferably has a maximum absorption in a desired range of about 0.3 or more and 2.0 or less. When the desired range is 750 to 1400 nm, the optical density at 750 to 360 nm is preferably 0.005 or more and less than 0.5, and further the antihalation layer having an optical density of 0.001 or more and less than 0.3. It is preferable that When the desired range is 750 nm or less, the maximum absorption of the desired range before image formation is 0.3 to 2.0, and the optical density at 360 to 750 nm after image formation is 0.005 to 0. It is preferable that the antihalation layer be less than .3. The method for lowering the optical density after image formation to the above range is not particularly limited. For example, as described in Belgian Patent No. 733,706, the density by a dye is lowered by decoloring by heating. And a method described in JP-A No. 54-17833 and a method for reducing the density by decoloring by light irradiation.
[0130]
Regarding the antihalation layer, paragraphs 0123 to 0124 of JP-A No. 11-65021, JP-A Nos. 11-223898, 9-230531, 10-36695, 10-104779, -231457, 11-352625, 11-352626 and the like.
[0131]
When antihalation dyes are used, these dyes can be any compound that has the desired absorption in the desired range, has sufficiently low absorption in the visible region after processing, and provides the preferred absorbance spectrum shape of the back layer. . For example, the following is disclosed, but the present invention is not limited to this. As individual dyes, JP-A-59-56458, JP-A-2-216140, JP-A-7-13295, JP-A-7-11432, US Pat. No. 5,380,635, No. 2-68539, page 13, lower left column, line 1 to page 14, lower left column, line 9; JP-A-3-245539, page 14, lower left column to page 16, lower right column; As the dyes to be erased by the treatment, JP-A-52-139136, 53-132334, 56-501480, 57-16060, 57-68831, 57- No. 101835, No. 59-182436, JP-A-7-36145, No. 7-199409, No. 11-231457, JP-B No. 48-33692, No. 50-16. 48, JP-B-2-41734, U.S. Pat. Nos. 4,088,497, 4,283,487, 4,548,896, 5,187,049 Examples include compounds described in the specification.
[0132]
Suitable binders for the back layer are transparent or translucent and are generally colorless, specifically using natural polymers, synthetic resins and polymers and copolymers, and other film-forming media such as: gelatin, gum arabic, Poly (vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid) ), Copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters) ) (Urethanes), phenoxy resins, poly (vinylidene chloride), poly (epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, poly (amides) and the like. The binder may be formed from water or an organic solvent or emulsion.
[0133]
In the photothermographic material of the invention, a matting agent may be added to the surface protective layer of the photosensitive layer (preferably the image forming layer) and / or the back layer or the surface protective layer of the back layer in order to improve transportability. Good. The matting agent is generally fine particles of an organic or inorganic compound that is insoluble in water. Any matting agent can be used, for example, U.S. Pat. Nos. 1,939,213, 2,701,245, 2,322,037, 3,262,782, and 3,539. , 344, 3,767, 448, etc., the organic matting agents, 1,260,772, 2,192,241, 3,257,206, 3, Those well known in the art such as the inorganic matting agent described in each specification such as 370,951, 3,523,022, and 3,769,020 can be used. Specific examples of organic compounds that can be used as a matting agent include water-dispersible vinyl polymers such as polymethyl acrylate, polymethyl methacrylate, polyacrylonitrile, acrylonitrile-α-methylstyrene copolymer, polystyrene, styrene-divinyl. Benzene copolymer, polyvinyl acetate, polyethylene carbonate, polytetrafluoroethylene, etc. Examples of cellulose derivatives include methylcellulose, cellulose acetate, cellulose acetate propionate, etc. Examples of starch derivatives include carboxy starch, carboxynitrophenyl starch, urea- Examples include gelatin hardened with a known hardener, such as formaldehyde-starch reaction product, and hardened gelatin obtained by coacervate hardening to form microcapsule hollow granules. Examples of the inorganic compound include silicon dioxide, titanium dioxide, magnesium dioxide, aluminum oxide, barium sulfate, calcium carbonate, silver chloride desensitized by a known method, silver bromide, glass, diatomaceous earth, and the like. The above matting agents can be used by mixing different kinds of substances as required. The size and shape of the matting agent are not particularly limited, and those having an arbitrary particle size can be used. In the present invention, it is preferable to use one having a particle size of 0.1 μm to 30 μm. The particle size distribution of the matting agent may be narrow or wide. On the other hand, since the matting agent greatly affects the haze and surface gloss of the photosensitive material, the particle size, shape, and particle size distribution can be brought into a state as necessary during the preparation of the matting agent or by mixing a plurality of matting agents. preferable.
[0134]
The matting agent is preferably contained in the outermost surface layer of the photosensitive material, the layer functioning as the outermost surface layer, or a layer close to the outer surface, and is preferably contained in a layer acting as a so-called protective layer. The matte degree of the emulsion surface protective layer may be any as long as no stardust failure occurs, but the Beck smoothness is preferably 500 to 10,000 seconds, and particularly preferably 500 to 2,000 seconds.
In the present invention, it is a preferred embodiment that the photothermographic material is a single-sided photosensitive material and a matting agent is added to the back layer. As the back layer mat degree, the Beck smoothness is preferably 10 to 1200 seconds, more preferably 50 to 700 seconds.
[0135]
In the photothermographic material of the present invention, the light-sensitive silver halide emulsion (heat-developable photographic emulsion) can constitute one or more layers on the support. Optional additional materials such as silver salts, silver halides, developers and binders, and toning agents, coating aids and other aids can be included. In the case of a two-layer construction, the first emulsion layer (usually the layer adjacent to the support) contains an organic silver salt and silver halide and the second or both layers contain some other component. Can do. However, a two-layer configuration comprising a single emulsion layer containing all components and a protective topcoat is also conceivable. The construction of a multicolor photosensitive photothermographic material may include a combination of these two layers for each color and all within a single layer as described in US Pat. No. 4,708,928. May be included. In the case of a multi-dye multicolor photosensitive photothermographic material, each emulsion layer is generally disposed between each emulsion layer (photosensitive layer) as described in US Pat. No. 4,460,681. By using functional or non-functional barrier layers, they are kept distinct from each other.
[0136]
It is also possible to use a backside resistive heating layer as shown in U.S. Pat. Nos. 4,460,681 and 4,374,921 in photosensitive photothermographic image systems. it can. In the photothermographic material of the present invention, a hardener may be used for each layer such as an image forming layer (photosensitive layer), a protective layer, and a back layer. Examples of hardeners include T.W. H. There are methods described in "THE THEORY OF THE PHOTOGRAPHIC PROCESS FOURTH EDITION" by James (published by Macmillan Publishing Co., Inc., published in 1977), pages 77 to 87. Chromium Alum, 2,4-Dichloro-6-hydroxy -S-triazine sodium salt, N, N-ethylenebis (vinylsulfonacetamide), N, N-propylenebis (vinylsulfonacetamide), polyvalent metal ions described on page 78 of the same, U.S. Pat. No. 4,281 , 060, polyisocyanates described in JP-A-6-208193, epoxy compounds described in US Pat. No. 4,791,042, JP-A-62-89048, etc. Listed vinyl Sulfone compounds are used.
[0137]
In the photothermographic material of the present invention, a surfactant may be used for the purpose of improving coating properties and charging. As an example of the surfactant, any nonionic, anionic, cationic, or fluorine-based one can be used as appropriate. Specifically, fluoropolymer surfactants described in JP-A-62-170950, US Pat. No. 5,380,644, etc., JP-A-60-244945, and 63-188135. No. 3,885,965, etc., polyalkylene oxides and anions described in JP-A-6-301140, etc. And surface active agents.
[0138]
The photothermographic material of the present invention is, for example, soluble salt (for example, chloride, nitrate, etc.), vapor-deposited metal layer, U.S. Pat. Nos. 2,861,056 and 3,206,312 for preventing static charge. Ionic polymers described in the specification of U.S. Pat. No. 3,428,451, insoluble inorganic salts described in JP-A-60-252349, and 57-104931. It may have a layer containing tin oxide fine particles.
[0139]
As a method for obtaining a color image using the photothermographic material of the present invention, there is a method described in JP-A-7-13295, page 10, left column, line 43 to 11, left column, line 40. Examples of color dye image stabilizers include British Patent No. 1,326,889, US Pat. Nos. 3,432,300, 3,698,909, and 3,574. No. 3,627, No. 3,573,050, No. 3,764,337 and No. 4,042,394.
[0140]
In the photothermographic material of the present invention, the light-sensitive silver halide emulsion (heat-developable photographic emulsion) may be of dip coating, air knife coating, flow coating, or the type described in US Pat. No. 2,681,294. It can be coated by various coating operations including extrusion coating using a hopper. If desired, two or more layers can be coated simultaneously by the methods described in US Pat. No. 2,761,791 and British Patent No. 837,095.
[0141]
The photothermographic material of the present invention includes additional layers such as a dye-receiving layer for receiving a moving dye image, an opacifying layer when reflective printing is desired, a protective topcoat layer, and a primer known in the photothermographic art. Layers can be included.
[0142]
In the photothermographic material of the invention, it is preferable that an image can be formed with only one photosensitive material, and it is preferable that a functional layer necessary for image formation such as an image receiving layer does not become another photosensitive material.
[0143]
Next, the image forming method of the present invention will be described.
The photothermographic material of the present invention can form an image by performing heat development after exposure (image forming method of the present invention). As a preferred embodiment of the heat developing machine to be used, as a type in which the photothermographic material is brought into contact with a heat source such as a heat roller or a heat drum, Japanese Patent Publication No. 5-56499, Japanese Patent No. 6844453, Japanese Patent Laid-Open No. 9-292695. As a non-contact type heat developing machine described in JP-A-9-297385, JP-A-11-133572, and WO95 / 30934, JP-A-7-13294, WO9797 There are thermal developing machines described in Japanese Patent Application Nos. / 28489, 97/28488 and 97/28487. A particularly preferred embodiment is a non-contact type heat developing machine. The preferred development temperature is 80 to 250 ° C, more preferably 100 to 140 ° C, more preferably 100 to 130 ° C, and particularly preferably 100 to 117 ° C. The development time is preferably 1 to 180 seconds, and more preferably 10 to 90 seconds.
[0144]
As a method for preventing processing unevenness due to dimensional change of the photothermographic material during heat development, after heating for 5 seconds or more so as not to produce an image at a temperature of 80 ° C. or higher and lower than 115 ° C. (preferably 113 ° C. or lower), It is effective to adopt a method (so-called multistage heating method) in which an image is formed by heat development at 110 ° C. or higher (preferably 130 ° C. or lower).
[0145]
The photothermographic material of the present invention may be exposed by any method, but a laser beam is preferred as the exposure light source. As the laser beam according to the present invention, a gas laser, a YAG laser, a dye laser, a semiconductor laser and the like are preferable. A semiconductor laser and a second harmonic generation element can also be used.
[0146]
The photothermographic material of the present invention has a low haze upon exposure and tends to generate interference fringes. This interference fringe generation prevention technique is disclosed in Japanese Patent Application Laid-Open No. 5-113548 or the like, in which a laser beam is incident obliquely on the photosensitive material, or in International Publication WO95 / 31754. Methods using multimode lasers are known and these techniques are preferably used.
[0147]
To expose the photothermographic material of the present invention, SPIE vol. 169 Laser Printing 116, page 128 (1979), Japanese Patent Application Laid-Open No. 4-51043, International Publication WO95 / 31754, and the like so that the laser beams are overlapped so that the scanning lines cannot be seen. It is preferable.
[0148]
Here, an example of a heat developing machine used for heat development processing of the photothermographic material of the present invention is shown. The photothermographic apparatus shown in FIG. 1 has a pair of carry-in rollers 11 (lower roller is a heat roller) that carries the photothermographic material 10 into a heating unit while correcting and preheating the photothermographic material 10 in a flat shape, and the photothermographic material 10 after heat development. A pair of carry-out rollers 12 is carried out from the heating unit while correcting the shape. The photothermographic material 10 is thermally developed while being conveyed from the carry-in roller pair 11 to the carry-out roller pair 12. The transport means for transporting the photothermographic material 10 during the heat development is provided with a plurality of rollers 13 on the side where the surface having the image forming layer contacts, and on the side where the back surface on the opposite side contacts, a non-woven fabric (for example, A smooth surface 14 on which an aromatic polyamide, Teflon (R), or the like is bonded is installed. The photothermographic material 10 is conveyed while the back surface slides on the smooth surface 14 by driving a plurality of rollers 13 that come into contact with the surface having the image forming layer. As the heating means, a heater 15 is installed at the upper part of the roller 13 and the lower part of the smooth surface 14 so as to be heated from both sides of the photothermographic material 10. In this case, a plate heater or the like is used as the heating means. The clearance between the roller 13 and the smooth surface 14 varies depending on the member of the smooth surface, but is appropriately adjusted to a clearance that allows the photothermographic material 10 to be conveyed. Preferably it is 0-1 mm.
[0149]
The material of the surface of the roller 13 and the member of the smooth surface 14 may be anything as long as they have high-temperature durability and do not interfere with the transport of the photothermographic material 10, but the material of the roller surface is silicone rubber, and the member of the smooth surface is aromatic. Non-woven fabric made of a group polyamide or Teflon (R) (PTFE) is preferred. As the heating means, it is preferable to use a plurality of heaters and freely set the heating temperature.
In addition, although a heating part is comprised by the preheating part A which has the carrying-in roller pair 11, and the heat development process part B provided with the heater 15, the preheating part A upstream of the heat development process part B is It is desirable that the temperature and time be lower than the heat development temperature (for example, lower by about 10 to 30 ° C.) and sufficient to evaporate the amount of water in the heat development photosensitive material 10. It is preferable to set so that development unevenness does not occur at a temperature higher than the glass transition temperature (Tg).
[0150]
A guide plate 16 is installed downstream of the heat development processing unit B, and a slow cooling unit C having the carry-out roller pair 12 and the guide plate 16 is installed. The guide plate 16 is preferably made of a material having low thermal conductivity, and cooling is preferably performed gradually.
[0151]
As described above, the description has been given with reference to the drawings. However, the present invention is not limited to this, and the heat developing machine used in the present invention may have various configurations, such as the one described in JP-A-7-13294. In the case of the multi-stage heating method preferably used in the present invention, two or more heat sources having different heating temperatures may be installed and heated at different temperatures continuously.
[0152]
【Example】
The present invention will be described more specifically with reference to the following examples. The materials, reagents, ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.
[0153]
(Preparation of PET support)
Using terephthalic acid and ethylene glycol, PET having an intrinsic viscosity of IV = 0.66 (measured at 25 ° C. in phenol / tetrachloroethane = 6/4 (weight ratio)) was obtained according to a conventional method. This was pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, and rapidly cooled to produce an unstretched film having a thickness of 175 μm after heat setting.
[0154]
This was longitudinally stretched 3.3 times using rolls with different peripheral speeds, and then stretched 4.5 times with a tenter. The temperatures at this time were 110 ° C. and 130 ° C., respectively. Thereafter, the film was heat-fixed at 240 ° C. for 20 seconds and relaxed by 4% in the lateral direction at the same temperature. After slitting the chuck part of the tenter, knurling is performed on both ends and 4 kg / cm.²And a roll having a thickness of 175 μm was obtained.
[0155]
(Surface corona treatment)
Using a solid state corona treatment machine 6KVA model manufactured by Pillar, both surfaces of the support were treated at room temperature at 20 m / min. From the current and voltage readings at this time, the support is 0.375 kV · A · min / m.²It was found that the process was done. The treatment frequency at this time was 9.6 kHz, and the gap clearance between the electrode and the dielectric roll was 1.6 mm.
[0156]
(Preparation of undercoat support)
(1) Preparation of undercoat layer coating solution
Formulation (1) (for the undercoat layer on the photosensitive layer side)
・ Pescasin A-515GB 234g manufactured by Takamatsu Yushi
(30% by weight solution)
・ Polyethylene glycol monononyl phenyl ether 21.5 g
(Average number of ethylene oxide = 8.5) 10% by mass solution
・ MP-1000 0.91g made by Soken Chemical Co., Ltd.
(Polymer fine particles, average particle size 0.4 μm)
-744 ml of distilled water
[0157]
Formulation (2) (for back layer 1st layer)
・ Styrene-butadiene copolymer latex 158g
(Solid content 40% by mass, styrene / butadiene weight ratio = 68/32)
2,4-dichloro-6-hydroxy-S-
20 g of triazine sodium salt aqueous solution 20 g
・ 10% 1% aqueous solution of sodium laurylbenzenesulfonate
-854 ml of distilled water
[0158]
Formula (3) (Back side 2nd layer)
・ SnO₂/ SbO 84g
(9/1 mass ratio, average particle size 0.038 μm, 17 mass% dispersion)
-Gelatin (10% by weight aqueous solution) 89.2g
・ Metrozu TC-5 (2% by mass aqueous solution) manufactured by Shin-Etsu Chemical Co., Ltd. 8.6 g
・ MP-1000 0.01g manufactured by Soken Chemical Co., Ltd.
・ 10% 1% aqueous solution of sodium dodecylbenzenesulfonate
・ NaOH (1% by mass) 6 ml
・ Proxel (ICI) 1ml
・ 805ml distilled water
[0159]
(Preparation of undercoat support)
After both surfaces of the biaxially stretched polyethylene terephthalate support having a thickness of 175 μm are subjected to the corona discharge treatment, the undercoat coating solution formulation {circle around (1)} is applied to one surface (photosensitive layer surface) with a wire bar. .6ml / m²(Per side) and dried at 180 ° C. for 5 minutes, and then the undercoat coating liquid formulation (2) is applied to the back side (back side) with a wire bar at a wet coating amount of 5.7 ml / m.²And then dried at 180 ° C. for 5 minutes. Further, the undercoat coating liquid formulation (3) is applied to the back surface (back surface) with a wire bar so that the wet coating amount is 7.7 ml / m.²And then dried at 180 ° C. for 6 minutes to prepare an undercoat support.
[0160]
(Preparation of back surface coating solution)
(Preparation of solid fine particle dispersion (a) of base precursor)
64 g of the base precursor compound 11, 28 g of diphenylsulfone and 10 g of surfactant demole N10 manufactured by Kao Corporation were mixed with 220 ml of distilled water, and the mixture was used with a sand mill (1/4 Gallon sand grinder mill, manufactured by Imex Corporation). The beads were dispersed to obtain a solid fine particle dispersion (a) of a base precursor compound having an average particle size of 0.2 μm.
[0161]
(Preparation of dye solid fine particle dispersion)
9.6 g of cyanine dye compound 13 and 5.8 g of sodium p-dodecylbenzenesulfonate are mixed with 305 ml of distilled water, and the mixture is dispersed in a bead using a sand mill (1/4 Gallon sand grinder mill, manufactured by IMEX Co., Ltd.). Thus, a dye solid fine particle dispersion having an average particle size of 0.2 μm was obtained.
[0162]
(Preparation of antihalation layer coating solution)
Gelatin 17 g, polyacrylamide 9.6 g, solid fine particle dispersion (a) 70 g of the above-mentioned precursor precursor, 56 g of the above dye solid fine particle dispersion, monodisperse polymethyl methacrylate fine particles (average particle size 8 μm, particle size standard deviation 0.4) 1.5 g, benzoisothiazolinone 0.03 g, polyethylene sulfonate sodium 2.2 g, blue dye compound 14 0.2 g, yellow dye compound 15 3.9 g, and water 844 ml are mixed to form an antihalation layer coating solution. Prepared.
[0163]
(Preparation of back surface protective layer coating solution)
The container was kept at 40 ° C., 50 g of gelatin, 0.2 g of sodium polystyrenesulfonate, 2.4 g of N, N-ethylenebis (vinylsulfonacetamide), 1 g of sodium t-octylphenoxyethoxyethanesulfonate, 30 mg of benzoisothiazolinone , Fluorine-based surfactant (F-1: N-perfluorooctylsulfonyl-N-propylalanine potassium salt) 37 mg, fluorine-based surfactant (F-2: polyethylene glycol mono (N-perfluorooctylsulfonyl-N-) Propyl-2-aminoethyl) ether [ethylene oxide average polymerization degree 15]) 0.15 g, fluorosurfactant (F-3) 64 mg, fluorosurfactant (F-4) 32 mg, acrylic acid / ethyl acrylate Copolymer (copolymerization weight ratio 5/9 ) 8.8 g, Aerosol OT (manufactured by American Cyanamid Co.) 0.6 g, and the back surface protective layer coating liquid was 950ml mixing 1.8g, water and liquid paraffin emulsion as liquid paraffin.
[0164]
<< Preparation of silver halide emulsion 1 >>
To a solution of 1421 ml of distilled water, 3.1 ml of a 1% by mass potassium bromide solution was added, and a solution containing 3.5 ml of 0.5 mol / L sulfuric acid and 31.7 g of phthalated gelatin was stirred in a stainless steel reaction vessel. While maintaining the liquid temperature at 30 ° C., the solution A diluted with 95.4 ml of distilled water added to 22.22 g of silver nitrate, 15.3 g of potassium bromide and 0.8 g of potassium iodide in a distilled water volume of 97.4 ml. The whole amount of the solution B diluted to 1 was added at a constant flow rate over 45 seconds. Thereafter, 10 ml of a 3.5% by mass aqueous hydrogen peroxide solution was added, and further 10.8 ml of a 10% by mass aqueous solution of benzimidazole was added. Further, a solution C in which distilled water was added to 51.86 g of silver nitrate to be diluted to 317.5 ml, a solution D in which 44.2 g of potassium bromide and 2.2 g of potassium iodide were diluted with distilled water to a volume of 400 ml was added to solution C. Was added at a constant flow rate over 20 minutes, and solution D was added by the controlled double jet method while maintaining pAg at 8.1. 1 x 10 per mole of silver^-FourThe total amount of potassium hexachloroiridate (III) was added 10 minutes after the start of the addition of Solution C and Solution D so as to have a molar ratio. In addition, 5 seconds after completion of the addition of the solution C, an aqueous solution of potassium iron (II) hexacyanide was added at 3 × 10 5 per mol of silver.^-FourThe whole molar amount was added. The pH was adjusted to 3.8 using 0.5 mol / L sulfuric acid, stirring was stopped, and a precipitation / desalting / water washing step was performed. The pH was adjusted to 5.9 with 1 mol / L sodium hydroxide to prepare a silver halide dispersion having a pAg of 8.0.
[0165]
While maintaining the silver halide dispersion at 38 ° C. with stirring, 5 ml of a methanol solution of 0.34% by mass of 1,2-benzisothiazolin-3-one was added, and after 40 minutes, the sensitizing dye A and the sensitizing dye A were increased. A methanol solution of 1: 1 in the molar ratio of dye B is 1.2 × 10 as the sum of sensitizing dyes A and B per mole of silver.^-3Mole was added and the temperature was raised to 47 ° C. after 1 minute. 20 minutes after the temperature rise, sodium benzenethiosulfonate was 7.6 × 10 6 in 1 mol of silver with a methanol solution.^-Five5 minutes later, tellurium sensitizer B was added in methanol solution to 2.9 × 10 6 per mole of silver.^-FourMole was added and aged for 91 minutes. 1.3 ml of a 0.8 mass% methanol solution of N, N′-dihydroxy-N ″ -diethylmelamine was added, and after 4 minutes, 5-methyl-2-mercaptoben ヅ imidazole was added to the methanol solution at 4 per mole of silver. .8x10^-3Mole and 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole in a methanol solution at 5.4 × 10 5 per mole of silver^-3A silver halide emulsion 1 was prepared by adding a molar amount.
[0166]
The grains in the prepared silver halide emulsion were silver iodobromide grains containing 3.5 mol% of iodine having an average sphere equivalent diameter of 0.042 μm and a sphere equivalent diameter variation coefficient of 20%. The particle size and the like were determined from an average of 1000 particles using an electron microscope. The {100} face ratio of the particles was determined to be 80% using the Kubelka-Munk method.
[0167]
<< Preparation of silver halide emulsion 2 >>
In the preparation of silver halide emulsion 1, the liquid temperature at the time of grain formation was changed from 30 ° C. to 47 ° C., and solution B was changed to diluting 15.9 g of potassium bromide with distilled water to a volume of 97.4 ml, Solution D was changed to diluting 45.8 g of potassium bromide with distilled water to a volume of 400 ml, and the addition time of solution C was changed to 30 minutes to remove potassium hexacyanoiron (II) in the same manner. A silver halide emulsion 2 was prepared. Precipitation / desalting / washing / dispersion was carried out in the same manner as silver halide emulsion 1. Further, the addition amount of the methanol solution having a molar ratio of the spectral sensitizing dye A and the spectral sensitizing dye B of 1: 1 is 7.5 × 10 5 as the total of the sensitizing dye A and the sensitizing dye B per mole of silver.^-FourMol, tellurium sensitizer B is added in an amount of 1.1 × 10 5 per mol of silver.^-FourMole, 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole, 3.3 × 10 3 per mole of silver^-3Spectral sensitization, chemical sensitization, and 5-methyl-2-mercaptoben ヅ imidazole, 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole in the same manner as Emulsion 1 except that the molar ratio was changed. Was added to obtain a silver halide emulsion 2. The emulsion grains of the silver halide emulsion 2 were pure silver bromide cubic grains having an average sphere equivalent diameter of 0.080 μm and a sphere equivalent diameter variation coefficient of 20%.
[0168]
<< Preparation of silver halide emulsion 3 >>
In the preparation of silver halide emulsion 1, silver halide emulsion 3 was prepared in the same manner except that the liquid temperature at the time of grain formation was changed from 30 ° C. to 27 ° C. Further, precipitation / desalting / washing / dispersion was performed in the same manner as silver halide emulsion 1. The molar ratio of spectral sensitizing dye A and spectral sensitizing dye B is 1: 1 as a solid dispersion (gelatin aqueous solution), and the addition amount is 6 × 10 as the total of sensitizing dye A and sensitizing dye B per mole of silver.^-3Mol, tellurium sensitizer B is added in an amount of 5.2 × 10 5 per silver mole^-FourA silver halide emulsion 3 was obtained in the same manner as Emulsion 1 except that the molar ratio was changed. The emulsion grains of the silver halide emulsion 3 were silver iodobromide grains containing 3.5 mol% of iodine having an average sphere equivalent diameter of 0.034 μm and a sphere equivalent diameter variation coefficient of 20%.
[0169]
<< Preparation of mixed emulsion A for coating solution >>
70% by weight of silver halide emulsion 1, 15% by weight of silver halide emulsion 2 and 15% by weight of silver halide emulsion 3 were dissolved, and benzothiazolium iodide was dissolved in a 1% by weight aqueous solution of 7% per mole of silver. × 10^-3Mole was added. Further, water was added so that the content of silver halide per 1 kg of the mixed emulsion for coating solution was 38.2 g as silver.
[0170]
<< Preparation of fatty acid silver dispersion >>
COGNIS DUTSCHLAND D GmbH's behenic acid (product name EDENOR C22-85JP GW) 87.6Kg, distilled water 423L, 5 mol / L NaOH aqueous solution 49.2L, tert-butanol 120L were mixed and stirred at 75 ° C for 1 hour. Reaction was performed to obtain a sodium behenate solution. Separately, 206.2 L (pH 4.0) of an aqueous solution containing 40.4 kg of silver nitrate was prepared and kept warm at 10 ° C. A reaction vessel containing 635 L of distilled water and 30 L of tert-butanol was kept at 30 ° C., and with sufficient stirring, the total amount of the previous sodium behenate solution and the total amount of silver nitrate aqueous solution were 93 minutes and 15 seconds at a constant flow rate, respectively. Added over 90 minutes. At this time, only the silver nitrate aqueous solution is added for 11 minutes after the start of the addition of the aqueous silver nitrate solution, and then the addition of the sodium behenate solution is started. After the addition of the aqueous silver nitrate solution, only the sodium behenate solution is added for 14 minutes and 15 seconds. It was made to be. At this time, the temperature in the reaction vessel was 30 ° C., and the external temperature was controlled so that the liquid temperature was constant. The pipe of the addition system for the sodium behenate solution was kept warm by circulating hot water outside the double pipe so that the liquid temperature at the outlet at the tip of the addition nozzle was 75 ° C. Moreover, the piping of the addition system of the silver nitrate aqueous solution 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 around the stirring axis, and were adjusted so as not to contact the reaction solution.
[0171]
After completion of the addition of the sodium behenate solution, the mixture was left stirring for 20 minutes at the same temperature, heated to 35 ° C. over 30 minutes, and then aged for 210 minutes. Immediately after completion of aging, the solid content was separated by centrifugal filtration, and the solid content was washed with water until the conductivity of filtered water reached 30 μS / cm. At that time, in order to promote a decrease in conductivity, an operation of adding pure water to the wet cake to form a slurry was performed three times. The obtained fatty acid silver wet cake was shaken off for 1 hour while the centrifugal force G was 700. G is 1.119 × 10^-Five× Container radius (cm) × Number of rotations (rpm)²It is expressed. The solid content of the fatty acid silver wet cake thus obtained (measured by drying 1 g of the wet cake at 110 ° C. for 2 hours) was 44%.
[0172]
When the morphology of the obtained silver behenate particles was evaluated by electron microscope photography, the average values were a = 0.14 μm, b = 0.4 μm, c = 0.6 μm, average aspect ratio 5.2, average sphere equivalent diameter. It was a flake-like crystal having a variation coefficient of 15% for a sphere equivalent diameter of 0.52 μm. (A, b, and c are the text provisions)
[0173]
19.3 kg of polyvinyl alcohol (trade name: PVA-217) and water are added to a wet cake corresponding to a dry solid content of 260 kg, and the whole amount is set to 1000 kg, and then slurried with a dissolver blade, and a pipeline mixer (manufactured by Mizuho Kogyo Co., Ltd.). : PM-10 type).
[0174]
Next, the pre-dispersed stock solution is subjected to a pressure of 1260 kg / cm of a disperser (trade name: Microfluidizer M-610, manufactured by Microfluidics International Corporation, using a Z-type interaction chamber).²And was treated three times to obtain a silver behenate dispersion. The cooling operation was carried out by installing a serpentine heat exchanger before and after the interaction chamber, and adjusting the temperature of the refrigerant to a dispersion temperature of 18 ° C.
[0175]
<< Preparation of Reducing Agent-1 Dispersion >>
Reducing agent-1 (1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane: compound (I-1) represented by the general formula (3)) 10 kg; 16 kg of water was added to 10 kg of a 20% by weight aqueous solution of modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203) and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 3 hours 30 minutes in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm, and then benzoisothiazolinone sodium salt 0.2 g and water were added to prepare a reducing agent concentration of 25% by mass to obtain a reducing agent-1 dispersion. The reducing agent particles contained in the reducing agent dispersion thus obtained had a median diameter of 0.42 μm and a maximum particle diameter of 2.0 μm or less. The obtained 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.
[0176]
<< Preparation of Reducing Agent-2 Dispersion >>
Reducing agent-2 (2,2′-isobutylidene-bis- (4,6-dimethylphenol): 10 kg of compound (I-2) represented by the general formula (3) and modified polyvinyl alcohol (manufactured by Kuraray Co., Ltd.) , Poval MP203) was added to 10 kg of a 20 mass% aqueous solution, and 16 kg of water was added and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 3 hours 30 minutes in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm, and then benzoisothiazolinone sodium salt 0.2 g and water were added to prepare a reducing agent concentration of 25% by mass to obtain a reducing agent-2 dispersion. The reducing agent particles contained in the reducing agent dispersion thus obtained had a median diameter of 0.38 μm and a maximum particle diameter of 2.0 μm or less. The obtained 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.
[0177]
<< Preparation of Reducing Agent Complex-3 Dispersion >>
Reductant complex-3 (1,2'-methylenebis- (4-ethyl-6-tert-butylphenol) and triphenylphosphine oxide 1: 1 complex: Compound (I-35) represented by formula (3) And 7.2 kg of water were added to 10 kg of a 10: 1 aqueous solution of triphenylphosphine oxide (1: 1 complex), 0.12 kg of triphenylphosphine oxide and 16 kg of 10% by weight aqueous solution of modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203). , Well mixed to make a slurry. This slurry was fed with a diaphragm pump and dispersed for 4 hours 30 minutes in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm, and then benzoisothiazolinone sodium salt 0.2 g and water were added to prepare a reducing agent concentration of 25% by mass to obtain a reducing agent complex-3 dispersion. The reducing agent complex particles contained in the reducing agent complex dispersion thus obtained 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 matters such as dust and stored.
[0178]
<< Preparation of Reducing Agent-4 Dispersion >>
Reducing agent-4 (2,2′-butylidene- (4-methyl-6-tert-butylphenol): compound (I-36) represented by the general formula (3))) 10 kg and modified polyvinyl alcohol (Kuraray Co., Ltd.) 6 kg of water was added to 20 kg of a 10% by weight aqueous solution of Poval MP203), and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump, dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 3 hours 30 minutes, and then benzoisothiazolinone sodium salt 0.2 g and water were added to prepare a reducing agent concentration of 25% by mass to obtain a reducing agent-4 dispersion. The reducing agent particles contained in the reducing agent dispersion thus obtained had a median diameter of 0.40 μm and a maximum particle diameter of 1.5 μm or less. The obtained reducing agent dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored.
[0179]
<< Preparation of dispersion of compound represented by general formula (1) or (2) of the present invention >>
To a compound represented by the general formula (1) or (2) of the present invention (types are listed in Table 1) (10 Kg) and a modified polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203) 10 mass% aqueous solution 20 Kg, 6 kg of water was added and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump, dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm as a standard time for 3 hours and 30 minutes, and then benzoisothiazo 0.2 g of linone sodium salt and water were added so that the concentration of the compound (1) or (2) was 15% by mass, and the compound represented by the general formula (1) or (2) of the present invention A dispersion was obtained. The particles of the compound contained in the dispersion thus obtained had a median diameter of 0.38 μm and a maximum particle diameter of 1.5 μm or less. The obtained dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust and stored. The dispersion time was adjusted so that the particle diameter of each compound was a median diameter of 0.38 μm.
[0180]
<< Preparation of hydrogen bonding compound-2 dispersion >>
Add 10 kg of water to 20 kg of a 10% aqueous solution of hydrogen bonding compound-2 (tri (4-t-butylphenyl) phosphine oxide) and denatured polyvinyl alcohol (Kuraray Co., Ltd., Poval MP203). Mix to make a slurry. This slurry was fed with a diaphragm pump and dispersed for 3 hours 30 minutes in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm, and then benzoisothiazolinone sodium salt 0.2 g and water were added to prepare a reducing agent concentration of 22% by mass to obtain a hydrogen bonding compound-2 dispersion. The reducing agent particles contained in the reducing agent dispersion thus obtained had a median diameter of 0.35 μm and a maximum particle diameter of 1.5 μm or less. The obtained 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.
[0181]
<< Preparation of organic polyhalogen compound-1 dispersion >>
10 kg of organic polyhalogen compound-1 (2-tribromomethanesulfonylnaphthalene), 10 kg of a 20% by weight aqueous solution of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.), and a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate. 4 kg and 16 kg of water were added and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 5 hours in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm. 2 g and water were added to prepare an organic polyhalogen compound concentration of 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 had a median diameter of 0.36 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.
[0182]
<< Preparation of organic polyhalogen compound-2 dispersion >>
10 kg of organic polyhalogen compound-2 (tribromomethanesulfonylbenzene), 10 kg of a 20% by weight aqueous solution of modified polyvinyl alcohol (Poval MP203 manufactured by Kuraray Co., Ltd.), 0.4 kg of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate, Then, 14 kg of water was added and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 5 hours in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm. 2 g and water were added to prepare an organic polyhalogen compound concentration of 26% by mass to obtain an organic polyhalogen compound-2 dispersion. 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.
[0183]
<< Preparation of organic polyhalogen compound-3 dispersion >>
10 kg of Yukin Polyhalogen Compound-3 (N-butyl-3-tribromomethanesulfonylbenzamide), 20 kg of a 10 wt% aqueous solution of modified polyvinyl alcohol (Kuraray Co., Ltd., POVAL MP203), and 20 wt% of sodium triisopropylnaphthalenesulfonate A 0.4% aqueous solution and 8 kg of water were added and mixed well to obtain a slurry. This slurry was fed with a diaphragm pump and dispersed for 5 hours in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm. 2 g and water were added to prepare an organic polyhalogen compound concentration of 25% by mass. 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 had a median diameter of 0.36 μm and a maximum particle diameter of 1.5 μm or less. The obtained organic polyhalogen 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.
[0184]
<< Preparation of Phthalazine Compound-1 Solution >>
8 kg of modified polyvinyl alcohol MP203 manufactured by Kuraray Co., Ltd. was dissolved in 174.57 kg of water, and then 3.15 kg of a 20 wt% aqueous solution of sodium triisopropylnaphthalenesulfonate and 70 wt% of phthalazine compound-1 (6-isopropylphthalazine). % Aqueous solution 14.28 kg was added to prepare a 5 mass% solution of phthalazine compound-1.
[0185]
<< Preparation of Mercapto Compound-1 Aqueous Solution >>
7 g of mercapto compound-1 (1- (3-sulfophenyl) -5-mercaptotetrazole sodium salt) was dissolved in 993 g of water to obtain a 0.7% by mass aqueous solution.
[0186]
<< Preparation of Mercapto Compound-2 Aqueous Solution >>
20 g of mercapto compound-1 (3- (3-methylureido) phenyl-5-mercaptotetrazole) was dissolved in 980 g of water to obtain a 2% by mass aqueous solution.
[0187]
<< Preparation of Pigment-1 Dispersion >>
C. I. Pigment Blue 60 (64 g) and Kao Corp. Demol N (6.4 g) were added to 250 g of water and mixed well to obtain 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 disperse with a disperser (1/4 G sand grinder mill: manufactured by IMEX Co., Ltd.) for 25 hours. Obtained. The pigment particles contained in the pigment dispersion thus obtained had an average particle size of 0.21 μm.
[0188]
<< Preparation of SBR Latex Liquid >>
The SBR latex with Tg = 23 ° C. was prepared as follows.
Ammonium persulfate was used as a polymerization initiator, an anionic surfactant was used as an emulsifier, and 70.5 mass of styrene, 26.5 mass of butadiene and 3 mass of acrylic acid were emulsion-polymerized, followed by aging at 80 ° C. for 8 hours. Thereafter, the mixture was cooled to 40 ° C., adjusted to pH 7.0 with aqueous ammonia, and Sandet BL manufactured by Sanyo Chemical Co., Ltd. was further added to 0.22%. Next, 5% aqueous sodium hydroxide solution was added to adjust the pH to 8.3, and further adjusted to pH 8.4 with aqueous ammonia. Na used at this time⁺Ion and NH_Four ⁺The molar ratio of ions was 1: 2.3. Further, 0.15 ml of 7% aqueous solution of benzoisothiazoline non sodium salt was added to 1 kg of this liquid to prepare an SBR latex liquid.
[0189]
(SBR latex: Latex of -St (70.5) -Bu (26.5) -AA (3)-)
Tg23 ° C., average particle size 0.1 μm, concentration 43% by mass, equilibrium water content 0.6% by mass at 25 ° C. 60% RH, ion conductivity 4.2 mS / cm (Ion conductivity is measured by Toa Denpa Kogyo Co., Ltd. ) Conductivity meter CM-30S was used, latex stock solution (43% by mass) was measured at 25 ° C.), pH 8.4, SBR latex with different Tg was changed appropriately by changing the ratio of styrene and butadiene. It was adjusted.
[0190]
<< Preparation of emulsion layer (photosensitive layer) coating solution-1 >>
1000 g of the fatty acid silver dispersion obtained above, 125 ml of water, 113 g of reducing agent-1 dispersion, 91 g of reducing agent-2 dispersion, 27 g of pigment-1 dispersion, 82 g of organic polyhalogen compound-1 dispersion, organic polyhalogen compound -2 dispersion 40 g, phthalazine compound-1 solution 173 g, SBR latex (Tg: 20.5 ° C.) liquid 1082 g, compound represented by general formula (1) or (2) of the present invention (type and amount are shown in Table 1) And 9 g of the mercapto compound-1 aqueous solution were sequentially added, and 158 g of the silver halide mixed emulsion A was added immediately before coating, and the emulsion layer coating solution mixed well was fed to the coating die as it was and coated.
[0191]
The viscosity of the emulsion layer coating solution was 85 [mPa · s] at 40 ° C. (No. 1 rotor, 60 rpm) as measured with a B-type viscometer of Tokyo Keiki.
[0192]
The viscosity of the coating solution at 25 ° C. using an RFS fluid spectrometer manufactured by Rheometrics Far East Co., Ltd. is 1500, 220, 70 at shear rates of 0.1, 1, 10, 100, and 1000 [1 / second], respectively. 40 and 20 [mPa · s].
[0193]
<< Preparation of emulsion layer (photosensitive layer) coating liquid-2 >>
1000 g of 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, SBR latex ( Tg: 23 ° C.) 1082 g of liquid, 258 g of reducing agent complex-3 dispersion, compound represented by general formula (1) or (2) (type and amount are listed in Table 1), and 9 g of mercapto compound-1 solution in this order. Immediately before coating, 110 g of silver halide mixed emulsion A was added and mixed well, and the emulsion layer coating solution was directly fed to the coating die and coated.
[0194]
<< Preparation of emulsion layer (photosensitive layer) coating solution-3 >>
1000 g of fatty acid silver dispersion obtained above, 114 ml of water, 149 g of reducing agent-4 dispersion, 30 g of pigment-1 dispersion, 21 g of organic polyhalogen compound-2 dispersion, 69 g of organic polyhalogen compound-3 dispersion, phthalazine compound -1 solution 173 g, SBR core-shell type latex (core Tg: 20 ° C./shell Tg: 30 ° C. = 70/30 weight ratio) liquid 1082 g, hydrogen bonding compound-2 dispersion 106 g, general formula (1) or (2) Emulsion in which 9 g of the mercapto compound-1 solution and 3 g of the mercapto compound-2 solution were added in that order, and the silver halide mixed emulsion A110 g was added and mixed well immediately before coating. The layer coating solution was fed directly to the coating die and applied.
[0195]
<Preparation of emulsion surface intermediate layer coating solution>
772 g of 10% by weight aqueous solution of polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.), 5.3 g of 20% by weight dispersion of pigment, methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization) (Weight ratio 64/9/20/5/2) 2 ml of 5% aqueous solution of aerosol OT (manufactured by American Cyanamid Co., Ltd.) and 226g of 27.5% latex solution by latex, 20% by weight aqueous solution of diammonium phthalate salt 10.5 ml, water was added to a total amount of 880 g, and the pH was adjusted to 7.5 with NaOH to obtain an intermediate layer coating solution of 10 ml / m²Then, the solution was fed to the coating die.
The viscosity of the coating solution was 21 [mPa · s] at a B-type viscometer of 40 ° C. (No. 1 rotor, 60 rpm).
[0196]
<< Preparation of emulsion surface protective layer first layer coating solution >>
Inert gelatin (64 g) is dissolved in water, and methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization weight ratio 64/9/20/5/2) 27.5% by weight latex 80 g, 23 ml of a 10% by weight methanol solution of phthalic acid, 23 ml of a 10% by weight aqueous solution of 4-methylphthalic acid, 28 ml of sulfuric acid having a concentration of 0.5 mol / L, and a 5% by weight aqueous solution of Aerosol OT (American Cyanamid Co., Ltd.) Add 5 ml, 0.5 g phenoxyethanol, 0.1 g benzoisothiazolinone, add water to make a total amount of 750 g, and use 26 ml of 4% by weight chromium alum mixed with a static mixer just before coating. 18.6 ml / m²Then, the solution was fed to the coating die.
The viscosity of the coating solution was 17 [mPa · s] at 40 ° C. (No. 1 rotor, 60 rpm) B-type viscometer.
[0197]
<< Preparation of emulsion surface protective layer second layer coating solution >>
Inert gelatin (80 g) is dissolved in water, and methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization weight ratio 64/9/20/5/2) 27.5% by weight of latex 102 g, 3.2 ml of a 5% by mass solution of a fluorosurfactant (F-1: N-perfluorooctylsulfonyl-N-propylalanine potassium salt), a fluorosurfactant (F-2: polyethylene glycol mono (N- Perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [ethylene oxide average polymerization degree = 15]) 2 mass% aqueous solution 32 ml, aerosol OT (manufactured by American Cyanamid Co., Ltd.) 5 mass% solution 23 ml , 4 g of polymethyl methacrylate fine particles (average particle size 0.7 μm), Water so that the total amount is 650 g in 21 g of dimethyl methacrylate fine particles (average particle size: 4.5 μm), 1.6 g of 4-methylphthalic acid, 4.8 g of phthalic acid, 44 ml of 0.5 mol / L sulfuric acid, and 10 mg of benzoisothiazolinone. , 445 ml of an aqueous solution containing 4% by weight of chromium alum and 0.67% by weight of phthalic acid was mixed with a static mixer immediately before coating to obtain a surface protective layer coating solution, 8.3 ml / m²Then, the solution was fed to the coating die.
The viscosity of the coating solution was 9 [mPa · s] at a B-type viscometer of 40 ° C. (No. 1 rotor, 60 rpm).
[0198]
<< Preparation of photothermographic material-1 >>
The anti-halation layer coating solution is applied to the back surface side of the undercoat support so that the solid content coating amount of the solid fine particle dye is 0.04 g / m.²In addition, the back surface protective layer coating solution has a gelatin coating amount of 1.7 g / m.²Then, a simultaneous multilayer coating was applied and dried to prepare a back layer.
[0199]
On the surface opposite to the back surface, the emulsion layer, the intermediate layer, the protective layer first layer, and the protective layer second layer were coated simultaneously in the order of the emulsion layer, intermediate layer, protective layer first layer by the slide bead coating method. ˜103). At this time, the emulsion layer and the intermediate layer were adjusted to 31 ° C., the protective layer first layer was adjusted to 36 ° C., and the protective layer first layer was adjusted to 37 ° C.
Coating amount of each compound in the emulsion layer (g / m²) Is as follows.
[0200]
・ Silver behenate 6.19
・ Reducing agent-1 0.67
・ Reducing agent-2 0.54
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
Compound of general formula (1) or (2): types and amounts are listed in Table 1.
Mercapto compound-1 0.002
Silver halide (as Ag) 0.145
[0201]
The coating and drying conditions are as follows.
The coating was performed at a speed of 160 m / min, the gap between the coating die tip and the support was set to 0.10 to 0.30 mm, and the pressure in the decompression chamber was set to be 196 to 882 Pa lower than the atmospheric pressure. The support was neutralized with an ion wind before coating.
In the subsequent chilling zone, after cooling the coating solution with a wind at a dry bulb temperature of 10 to 20 ° C., it is transported in a non-contact type, and is dried at a dry bulb temperature of 23 to 45 ° C. It dried with the dry wind of the wet bulb temperature 15-21 degreeC.
After drying, the humidity was adjusted at 25 ° C. and humidity of 40 to 60% RH, and then the film surface was heated to 70 to 90 ° C. After heating, the film surface was cooled to 25 ° C.
[0202]
The photothermographic material thus prepared had a Beck smoothness of 550 seconds on the photosensitive layer surface side and 130 seconds on the back surface. Further, the pH of the film surface on the photosensitive layer surface side was measured and found to be 6.0.
[0203]
<< Preparation of photothermographic material-2 >>
Emulsion layer coating solution-1 was changed to emulsion layer coating solution-2 for photothermographic material-1, and the yellow dye compound 15 was further removed from the antihalation layer. Thus, photothermographic material-2 (Samples 201 to 203) was produced.
The coating amount of each compound in the emulsion layer (g / m²) Is as follows.
[0204]
・ 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 (1) or (2): types and amounts are listed in Table 1.
Mercapto compound-1 0.002
Silver halide (as Ag) 0.10
[0205]
<< Preparation of photothermographic material-3 >>
Emulsion layer coating solution-1 was changed to emulsion layer coating solution-3 for photothermographic material-1, and yellow dye compound 15 was removed from the antihalation layer. In addition, the fluorosurfactants F-1, F-2, F-3 and F-4 of the protective layer second layer and the back surface protective layer are respectively F-5, F-6, F-7 and Changed to F-8. Photothermographic material-3 (Samples 301 to 320) was prepared in the same manner as in the photothermographic material-1.
The coating amount of each compound in the emulsion layer (g / m²) Is as follows.
[0206]
・ Silver behenate 5.57
Pigment (CI Pigment Blue 60) 0.032
・ Reducing agent-4 0.76
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
Compound of general formula (1) or (2): types and amounts are listed in Table 1.
Mercapto compound-1 0.002
Mercapto compound-2 0.001
Silver halide (as Ag) 0.09
[0207]
The chemical structures of the compounds used in the examples of the present invention are shown below.
[0208]
Embedded image
[0209]
Embedded image
[0210]
Embedded image
[0211]
Embedded image
[0212]
Embedded image
[0213]
(Evaluation of photographic performance)
The obtained photothermographic material is subjected to the following development processes (1) to (3), and the obtained image density is measured with a Macbeth densitometer (Macbeth Co.). The value when the standard development of the sample 101 was 100 was expressed as a relative value and the sensitivity was evaluated. The higher the relative value, the higher the feeling. Similarly, the non-image area (unexposed area) was also expressed as a relative value, and fog was evaluated. In addition, in order to change the heat development conditions, an experiment was conducted by modifying the heat developing machine.
[0214]
(1) Standard development
Photographic materials were exposed and heat-developed with Fuji Medical Dry Laser Imager FM-DP L (equipped with a 660 nm semiconductor laser with a maximum output of 60 mW (IIIB)). The photothermographic materials-1 and 2 were processed with a heat development time of 24 seconds, and the photothermographic material-3 with a heat development time of 14 seconds.
[0215]
It went by.
(2) -3 ° C high temperature development
The processing was performed under the same conditions as in the above standard development, but the thermal development part was evaluated by setting four panel heaters at 109 ° C.-116 ° C.-118 ° C.-118 ° C.
(3) Short time development
The processing was performed under the same conditions as the standard development described above, but the heat development time was shortened, the processing was performed in 19 seconds when the standard development time was 24 seconds, and the processing was performed in 11 seconds when the standard development time was 14 seconds. And evaluated.
[0216]
[Table 1]
[0217]
The comparative compounds C-1 to C-3 in the table are shown below.
[0218]
Embedded image
[0219]
From the results in Table 1, the photothermographic material using the compound represented by the general formula (1) or (2) and the compound represented by the general formula (3) in combination with high sensitivity and low fog, It can be seen that performance fluctuations are small with respect to changes in processing conditions such as short development time and high development temperature.
[0220]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a novel photothermographic material and an image forming method that have high sensitivity, little fog, rapid development, and little change in performance due to fluctuations in the thermal development temperature.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an example of a heat developing machine applied to an image forming method of the present invention.
[Explanation of symbols]
10 Photothermographic material
11 Carry-in roller
12 Unloading roller
13 Roller
14 Smooth surface
15 Heating heater
16 Guide plate
A Preheating section
B Thermal development processing section
C Slow cooling part

Claims (9)

On the same surface of the support, at least a photosensitive silver halide, an organic silver salt , a binder, a compound represented by the following general formula (1) or (2), and a general formula (3) A photothermographic material containing : a photothermographic material containing :
(In General Formula (1), R ¹ represents an alkyl group, an aryl group, an alkenyl group, or an alkynyl group, and X ¹ represents an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group, or a sulfamoyl group. Y ¹ to Y ⁵ each independently represents a hydrogen atom or a substituent.) ;
(In General Formula (2), X ²¹ represents a group —NX ³¹ X ^32. X ³¹ and X ³² each independently represent a hydrogen atom or a substituent. Y ²⁵ represents an alkoxy group or an aryloxy group. Y ²¹ to Y ²⁴ and Y ²⁶ each independently represent a hydrogen atom or a substituent.) ;
(In General Formula (3), V ^{2 to} V ⁹ each independently represents a hydrogen atom or a substituent. L represents a linking group of —CH (V ¹⁰ ) — or —S—, and V ¹⁰ represents a hydrogen atom or a substituent. Represents a substituent) . The photothermographic material according to claim 1, wherein the compound represented by the general formula (1) or (2) is a compound represented by the following general formula (1):
(In the general formula (1), R ¹ Represents an alkyl group, an aryl group, an alkenyl group or an alkynyl group, and X ¹ Represents an acyl group, an alkoxycarbonyl group, a carbamoyl group, a sulfonyl group or a sulfamoyl group. Y ¹ ~ Y ⁵ Each independently represents a hydrogen atom or a substituent. ). The photothermographic material according to claim 1 or claim 2 X ¹ in the compound represented by formula (1), characterized in that a carbamoyl group. 4. The photothermographic material according to claim 3, wherein X ¹ in the compound represented by the general formula (1) represents an alkylcarbamoyl group or an arylcarbamoyl group. 5. The photothermographic material according to claim 4 , wherein X ¹ in the compound represented by the general formula (1) represents an arylcarbamoyl group. R ¹ in the compound represented by formula (1) A heat-developable photosensitive material according to any one of claims 1 to 5, characterized in that an alkyl group or an aryl group. R in the compound represented by the general formula (1) ¹ Is an alkyl group, X ¹ Is a carbamoyl group, Y ¹ ~ Y ^Five The photothermographic material according to claim 1, wherein is a hydrogen atom. The photothermographic material according to any one of claims 1 to 7, characterized in that it further comprises an ultra-high contrast agent. After the photothermographic material according to any one of claims 1 to 8, were exposed, the image forming method characterized by forming an image by heat development.