JP2001117195A - Processing method for heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a processing method for a heat developable photosensitive material by which high sensitivity, high gradation and improved thermal and dimensional stabilities are ensured and the occurrence of black spots is prevented. SOLUTION: A heat developable photosensitive material having photosensitive silver halide, an organic silver salt, a reducing agent for silver ions and a binder on the substrate is processed with an automatic heat processing machine having a heating part comprising a section having 0.5-2 deg.C/cm temperature gradient A represented by the equation A=Δt/x [where Δt is raised temperature ( deg.C) and (x) is conveyance distance (cm)] and a section kept at a constant temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for processing a photothermographic material.

[0002]

2. Description of the Related Art In the past several years, plate making operations have changed greatly from manual operations to electronic plate collection. In such a flow, plotters such as imagesetters are rapidly spreading. A processing machine for a conventional silver halide photographic material is connected online to such precision equipment, and gas and moisture from the processing solution corrode the base, and failure of expensive equipment is increasing.

In conventional silver halide photographic materials, a water supply pipe is required for development, dilution of a fixing solution and washing with water, and it is troublesome to have a contractor handle waste liquid. Under such circumstances, a dry treatment system that does not use water is expected. Of the dry systems, thermal development is most suitable for practical use in terms of manufacturing cost and performance.

As this technique, for example, US Pat.
Nos. 152,904, 3,487,075 and D.I. "Dry Silver Photographic" by Morgan
Materials) "(Handbook of
Imaging Materials, MarcelD
ekker, Inc. As described in, for example, page 48, 1991), a heat developing material containing an organic silver salt, photosensitive silver halide particles, a reducing agent and a binder on a support is known.

[0005] These heat-developable materials are stable at room temperature, but are developed by heating to a high temperature (for example, 80 ° C to 140 ° C) after exposure. That is, heating produces silver through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. However, photosensitive silver halide, organic silver salts, reducing agents and binders for silver ions,
When a photothermographic material for printing plate making containing hydrazine or a quaternary onium salt is developed by a thermal developing machine, the characteristics of the photosensitive material change according to a subtle change in development heat, causing a problem.

[0006] In a recording material for printing plate making, thermal dimensional stability of a film before and after thermal development is an important subject. In particular, when polyester is used as the support, the glass transition temperature (Tg) of the polyester film is usually 80%.
° C, while the heat development temperature is from 110 ° C to 125 ° C.
When performed at a temperature of as high as ° C., the residual strain during the formation of the polyester film is relaxed, and a large dimensional shrinkage of 0.3% or more occurs. Such dimensional shrinkage causes serious problems such as color misregistration as a printing plate making material. As a method of reducing the dimensional change during thermal development, it is known that a support is subjected to a thermal relaxation treatment before coating the photosensitive layer. However, in a photothermographic material containing a high contrast agent, When developed using a relaxation film support, deformation due to thermal expansion occurs, causing a difference in heat transfer from the heated surface, causing a serious problem that many black pots are locally generated, and immediate improvement is requested. ing.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for processing a photothermographic material having high sensitivity, high gradation, improved thermal dimensional stability, and preventing occurrence of black spots. That is.

[0008]

The object of the present invention has been attained by the following constitutions. 1. In a method for processing a photothermographic material having a photosensitive silver halide, an organic silver salt, a reducing agent for silver ions and a binder on a support, the temperature gradient is constant at a site represented by the following formula (1) and the temperature is constant. A method for processing a photothermographic material, wherein the processing is carried out using an automatic thermal developing machine having a heating section consisting of a part kept at a constant temperature.

Formula (1) A = Δt / x In the formula, A represents a temperature gradient (° C./cm), Δt represents a temperature rise (° C.), x represents a transport distance (cm), and the value of A is 0.5
≦ A ≦ 2. 2. 2. The method for processing a photothermographic material according to claim 1, wherein the processing speed of the automatic thermal developing machine is 21 mm / sec or more. 3. 3. The method for processing a photothermographic material according to item 1 or 2, wherein the photothermographic material to be processed contains a high contrast agent. 4. 4. The method for processing a photothermographic material according to item 3, wherein the photothermographic material has a support that has been heat-treated while being conveyed at a temperature of 80 to 200 ° C. and a tension of 4 kPa or less. .

Hereinafter, the present invention will be described in detail. As a processing method of the photothermographic material according to the present invention,
The heat development process is performed sequentially through the preheating section, developing section and cooling section of the automatic thermal developing machine. The automatic thermal developing machine according to the present invention is characterized in that it has a heating section composed of a portion having a temperature gradient represented by the above formula (1) and a portion having a constant temperature. The heating section in the present invention refers to the preheating section and the developing section in the above configuration.

The photothermographic material is susceptible to temperature variations in the heating section and tends to cause uneven development. Therefore, JP-A-9-297384, JP-A-9-297385, and JP-A-9-297385
An automatic thermal developing machine of a heat drum type as disclosed in JP-A-297386, and a planar transport type automatic thermal developing machine as disclosed in WO 98/27458 are used. In particular, in the processing of a photothermographic material used for printing plate making, it is preferable that the photothermographic material is processed by a flat transport type automatic thermal developing machine in order to improve dimensional stability.

The automatic thermal developing machine according to the present invention has a preheating section in front of the developing section, and a feature of the present invention is that the processing temperature of the preheating section is not constant but continuously changed. It has been found that this greatly improves dimensional stability. Further, the development is advanced by the preheating and the density unevenness is reduced, so that it is also effective for the scanning unevenness. Note that the slope A in the above equation (1) is 0.5 to
2.0, and preferably 0.7 to 1.5.

[0013] The pre-heating section is 5 ° below the developing temperature of the developing section.
Temperatures lower than or equal to ° C are preferred. Temperature control range is 100 ~
120 ° C is preferred, and 100 to 115 ° C is more preferred. The processing time of the preheating section is preferably 1 to 60 seconds,
5 to 50 seconds are more preferred. As the means for heating the preheating portion, a heating element described in JP-A-61-145544 such as a mode having a conductive heating element layer, a halogen lamp, a sheet heater, or the like can be used. Medium heated to a certain temperature (metal roller, silicone rubber, urethane rubber,
There is no particular limitation as long as it can be brought into contact with paper, a fluorinated medium or the like for a predetermined time. In the present invention, a roller having a built-in sheet heater or heating element is preferable. In the case of a roller, an opposing roller is preferable, and more than one pair and six or less are preferable. The heating element may be incorporated into only one side or both sides of the roller, and there is no particular limitation.

For controlling the heating temperature of the preheating section, a specified heating temperature pattern can be obtained by installing a temperature sensor in the heating zone, monitoring the temperature of each section, and adjusting the output of these heat sources. For this reason, it is preferable to divide these heat sources into several and control them individually, or to arrange a plurality of rollers each containing a heating element having an independent temperature control mechanism.

The preferred temperature range of the developing section is 100 to 15
The temperature is preferably 0 ° C, more preferably 100 to 140 ° C, and the present invention is characterized in that the treatment is performed under a constant temperature condition.
In the present invention, the preferable processing time range of the developing section is 3
-30 seconds are preferable, and 5-30 seconds are more preferable. In performing such thermal development, it is preferable not to apply tension to the photothermographic material, but there is no particular limitation as long as it is 10 kg or less. However, if the tension is applied too much, the dimensions of the photosensitive material change, which causes a problem in the form and requires attention.

The cooling unit can be used without particular limitation as long as it can rapidly cool, such as air from a cooling fan, contact with a cooling plate, contact with a metal roller, and the like. It is preferable that the temperature of the photothermographic material discharged from the development processor is 50 ° C. or less at the time when the photothermographic material leaves the apparatus. Exposure to light while the temperature is high causes fogging. The processing method according to the second aspect of the present invention is characterized in that the processing speed of the automatic thermal developing machine is 21 mm / sec or more, preferably 25 to 80 mm / sec, more preferably 30 to 60 mm / sec.
mm / sec. By performing the thermal development processing at the transport speed according to the present invention, the effect of stabilizing the thermal dimension of the heating unit according to claim 1 can be further exhibited. At a transport speed of less than 21 mm / sec, it is difficult to optimally set the temperature gradient in claim 1, and the effect of the present invention cannot be sufficiently exhibited.

The photothermographic material according to claim 3 is characterized in that it contains a high contrast agent. The black spot failure, which is a disadvantage of the high gradation photothermographic material containing a high contrast agent, is greatly improved by performing the processing using the heat development processing method according to the present invention. Preferred contrast agents include hydrazine derivatives, compounds represented by the following general formula (G), and quaternary onium compounds represented by the following general formula (P).

[0018]

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In the general formula (G), X and R are represented in the form of cis. However, the general formula (G) also includes the form in which X and R are trans. This is the same in the structural representation of a specific compound. In the general formula (P), Q represents a nitrogen atom or a phosphorus atom, and R ₁ , R ₂ , R ₃ and R ₄ each represent
It represents a hydrogen atom or a substituent, X ^- represents an anion.
Incidentally, R _{1 to} R ₄ may be connected to each other to form a ring.

Examples of the hydrazine derivative include a compound represented by the following general formula [H].

[0021]

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In the formula, A ₀ represents an aliphatic group, an aromatic group, a heterocyclic group or a -G ₀ -D ₀ group which may have a substituent;
B ₀ represents a blocking group, and A ₁ and A ₂ each represent a hydrogen atom, or one represents a hydrogen atom and the other represents an acyl group, a sulfonyl group, or an oxalyl group. Here, G ₀ is -CO-
Group, -COCO- group, -CS- group, -C (= NG ₁ D ₁ )
— Group, —SO— group, —SO ₂ — group or —P (O) (G ₁ D
₁ ) represents a group, G ₁ represents a mere bond, an —O— group, —S—
Group or -N (D ₁₎ - represents a group, D ₁ is an aliphatic group, an aromatic group, a heterocyclic group or a hydrogen atom, a plurality of D ₁ in the molecule
If they are present, they can be the same or different. D ₀ is a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group,
Represents an amino group, an alkoxy group, an aryloxy group, an alkylthio group, or an arylthio group. Preferred D ₀ includes a hydrogen atom, an alkyl group, an alkoxy group, an amino group and the like.

In the general formula [H], the aliphatic group represented by A ₀ preferably has 1 to 30 carbon atoms, and particularly preferably a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms. For example, methyl group, ethyl group, t-butyl group, octyl group, cyclohexyl group, benzyl group,
These may be further substituted with a suitable substituent (for example, aryl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, sulfoxy group, sulfonamide group, sulfamoyl group, acylamino group, ureido group, etc.). .

In the general formula [H], the aromatic group represented by A ₀ is preferably a monocyclic or condensed-ring aryl group, for example, a benzene ring or a naphthalene ring, and a heterocyclic group represented by A _0. The group is preferably a heterocyclic ring containing at least one heteroatom selected from nitrogen, sulfur, and oxygen atom in a single ring or a condensed ring, for example, a pyrrolidine ring, an imidazole ring, a tetrahydrofuran ring, a morpholine ring, a pyridine ring, a pyrimidine ring, Examples include a quinoline ring, a thiazole ring, a benzothiazole ring, a thiophene ring and a furan ring. Aromatic groups A _0, heterocyclic group or -G ₀ -D ₀ group may have a substituent. Particularly preferred as A ₀ are an aryl group and a -G ₀ -D ₀ group.

In the general formula [H], A ₀ preferably contains at least one of a diffusion-resistant group or a silver halide-adsorbing group. As the diffusion-resistant group, a ballast group commonly used in immobile photographic additives such as couplers is preferable, and as the ballast group, a photographically inactive alkyl group, alkenyl group, alkynyl group, alkoxy group, phenyl Group,
Examples thereof include a phenoxy group and an alkylphenoxy group, and the total number of carbon atoms in the substituent is preferably 8 or more.

In the general formula [H], examples of the silver halide adsorption accelerating group include thiourea, thiourethane group, mercapto group, thioether group, thione group, heterocyclic group, thioamide heterocyclic group, mercapto heterocyclic group and special groups. 64-9
No. 0439. In the general formula [H], B ₀ represents a blocking group, preferably a -G ₀ -D ₀ group, and G ₀ represents a -CO- group, -COC
O-group, -CS- group, -C (= NG ₁ D ₁ )-group, -SO
—, —SO ₂ — or —P (O) (G ₁ D ₁ ) —. Preferable G ₀ includes a —CO— group and a —COCO— group, G ₁ represents a mere bond, a —O— group, a —S— group or a —N (D ₁ ) — group, and D ₁ represents a fatty acid. Group, an aromatic group, a heterocyclic group or a hydrogen atom, and a plurality of D ₁
If they are present, they can be the same or different. D ₀ is a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group,
It represents an amino group, an alkoxy group, an aryloxy group, an alkylthio group, or an arylthio group, and preferred D ₀ includes a hydrogen atom, an alkyl group, an alkoxy group, an amino group, and the like. A ₁ and A ₂ are both hydrogen atoms, or one is a hydrogen atom and the other is an acyl group (acetyl group, trifluoroacetyl group, benzoyl group, etc.), a sulfonyl group (methanesulfonyl group, toluenesulfonyl group, etc.), or an oxalyl group (Such as an ethoxalyl group).

Next, specific examples of the compound represented by the general formula [H] are shown below, but it should not be construed that the invention is limited thereto.

[0028]

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[0029]

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[0030]

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[0031]

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[0032]

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[0033]

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[0034]

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More preferred hydrazine derivatives are represented by the following formulas (H-1), (H-2), (H-3) and (H-4)
It is represented by

[0036]

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In the general formula (H-1), R ₁₁ , R ₁₂ and R ₁₃ each independently represent a substituted or unsubstituted aryl group or heteroaryl group. Specific examples of the aryl group include phenyl, p-Methylphenyl, naphthyl and the like. Specific examples of the heteroaryl group include, for example, a triazole residue, an imidazole residue,
Examples include a pyridine residue, a furan residue, and a thiophene residue. Further, R ₁₁ , R ₁₂ and R ₁₃ may be bonded via an arbitrary linking group. When R ₁₁ , R ₁₂ and R ₁₃ have a substituent, examples of the substituent include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, and a quaternary heterocyclic group containing a nitrogen atom ( For example, a pyridinio group), a hydroxy group, an alkoxy group (including a group containing a repeating ethyleneoxy or propyleneoxy group unit), an aryloxy group, an acyloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, and a urethane Group, carboxyl group, imide group, amino group, carbonamide group, sulfonamide group, ureido group, thioureido group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, hydrazino group, quaternary ammonium group, (alkyl,
Aryl or heterocycle) thio group, mercapto group,
(Alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, sulfo group, sulfamoyl group, acylsulfamoyl group, (alkyl or aryl) sulfonyluureido group, (alkyl or aryl) sulfonylcarbamoyl group, halogen atom, cyano Group, nitro group, phosphoric acid amide group and the like. Each of R ₁₁ , R ₁₂ and R ₁₃ is preferably a substituted or unsubstituted phenyl group, and more preferably, each of R ₁₁ , R ₁₂ and R ₁₃ is an unsubstituted phenyl group.

R ₁₄ represents a heteroaryloxy group or a heteroarylthio group. Specific examples of the heteroaryloxy group include a pyridyloxy group, a pyrimidyloxy group,
Examples include an indolyloxy group, a benzothiazolyloxy group, a benzimidazolyloxy group, a furyloxy group, a thienyloxy group, a pyrazolyloxy group, and an imidazolyloxy group. Specific examples of the heteroarylthio group include a pyridylthio group, a pyrimidylthio group, an indolylthio group, a benzothiazolylthio group, a benzimidazolylthio group, a furylthio group, a thienylthio group, a pyrazolylthio group, and an imidazolylthio group. R ₁₄ is preferably a pyridyloxy group or a thienyloxy group.

A₁, A_TwoAre both hydrogen atoms, or one is
The other is an acyl group (acetyl, trifluoroa
Cetyl, benzoyl, etc.), sulfonyl group (methanesulfo
Oxyl, toluenesulfonyl, etc.) or oxalyl group (d
Etc.). Preferably A₁, A_TwoBoth hydrogen
This is the case for atoms. In the general formula (H-2), R_{twenty one}Is
A substituted or unsubstituted alkyl group, aryl group or
Represents a teloaryl group, but specifically as an alkyl group
Represents a methyl group, an ethyl group, a t-butyl group, 2-octyl
Group, cyclohexyl group, benzyl group, diphenylmethyl
And the like. Aryl and heteroaryl groups
Specifically, R₁₁, R₁₂And R ₁₃Similar to
I can do it. Also, R_{twenty one}Is a substituent when
As a specific example, R₁₁, R₁₂And R₁₃Same as the substituent of
And the like. R_{twenty one}Preferably as aryl
Group or heteroaryl group, particularly preferably substituted
Alternatively, it is an unsubstituted phenyl group.

[0040] R ₂₂ is hydrogen, alkylamino group, an arylamino group, represents a heteroaryl group, specifically as alkylamino group, methylamino group, ethylamino group, propylamino group, butylamino group, dimethylamino Examples include an amino group, a diethylamino group, and an ethylmethylamino group. As the arylamino group, an anilino group,
Examples of the heteroaryl group include a thiazolylamino group, a benzimidazolylamino group, and a benzthiazolylamino group. Preferably the R ₂₂ is dimethylamino group or diethylamino group.

A ₁ and A ₂ are those represented by the general formula (H-1)
₁ is the same as A _2. In the general formula (H-3),
R ₃₁ and R ₃₂ each represent a monovalent substituent. Examples of the monovalent substituent include the same substituents as those of R ₁₁ , R ₁₂ and R _13. Groups, heteroaryl groups, alkoxy groups, and amino groups.
More preferably, it is an aryl group or an alkoxy group.
Particularly preferred is that at least one of R ₃₁ and R ₃₂ is te
It is an rt-butoxy group, and another preferred structure is that when R ₃₁ is a phenyl group, R ₃₂ is a tert-butoxy group.

G ₃₁ and G ₃₂ represent a — (CO) p- group, and —C (=
S)-, a sulfonyl group, a sulfoxy group, -P (= O) R
Represents a ₃₃ -group or an iminomethylene group, p represents an integer of 1 or 2, R ₃₃ represents an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an alkoxy group, an alkenyloxy group, an alkynyloxy group, an aryloxy group, Represents an amino group. However, when G ₃₁ is a sulfonyl group, G ₃₂ is not a carbonyl group. G ₃₁ and G ₃₂ are preferably -CO
—, —COCO—, sulfonyl or —CS—, more preferably —CO— or mutually sulfonyl.

A ₁ and A ₂ are those represented by the general formula (H-1)
₁ is the same as A _2. In the general formula (H-4),
R ₄₁ , R ₄₂ and R ₄₃ have the same meanings as R ₁₁ , R ₁₂ and R ₁₃ in formula (H-1). Each of R ₄₁ , R ₄₂ and R ₄₃ is preferably a substituted or unsubstituted phenyl group, more preferably R ₄₁ , R ₄₂ and R ₄₃
Is an unsubstituted phenyl group. R ₄₄ and R ₄₅ represent an unsubstituted or substituted alkyl group, and specific examples include a methyl group, an ethyl group, a t-butyl group, a 2-octyl group, a cyclohexyl group, a benzyl group, and a diphenylmethyl group. No. R ₄₄ and R ₄₅ are preferably each an ethyl group.

A ₁ and A ₂ represent A represented by the general formula (H-1)
₁ is the same as A _2. The general formula (H-1) of the present invention is described below.
Specific examples of the compounds represented by formulas (1) to (H-4) will be given below, but the present invention is not limited thereto.

[0045]

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[0046]

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[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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The compounds represented by the general formulas (H-1) to (H-
The compound represented by 4) can be easily synthesized by a known method. For example, US Pat. No. 5,464,73
No. 8 or U.S. Pat. No. 5,496,695. Other hydrazine derivatives that can be preferably used are described in US Pat. No. 5,545,545.
Compounds H-1 to H- described in No. 505 columns 11 to 20
29, U.S. Pat. No. 5,464,738, columns 9-11.
And compounds 1 to 12. These hydrazine derivatives can be synthesized by a known method.

In the general formula (G), X represents an electron-withdrawing group, and W is a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a halogen atom,
Acyl group, thioacyl group, oxalyl group, oxyoxalyl group, thiooxalyl group, oxamoyl group, oxycarbonyl group, thiocarbonyl group, carbamoyl group, thiocarbamoyl group, sulfonyl group, sulfinyl group, oxysulfonyl group, thiosulfonyl group, sulfamoyl Group, oxysulfinyl group, thiosulfinyl group, sulfinamoyl group, phosphoryl group, nitro group, imino group,
An N-carbonylimino group, an N-sulfonylimino group, a dicyanoethylene group, an ammonium group, a sulfonium group,
Represents a phosphonium group, a pyrylium group, or an immonium group.

R represents a halogen atom, a hydroxy group, an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkenyloxy group, an acyloxy group, an alkoxycarbonyloxy group, an aminocarbonyloxy group, a mercapto group,
Organic or inorganic salts of an alkylthio group, an arylthio group, a heterocyclic thio group, an alkenylthio group, an acylthio group, an alkoxycarbonylthio group, an aminocarbonylthio group, a hydroxy group or a mercapto group (for example, sodium salt, potassium salt, silver salt) Etc.), an amino group, an alkylamino group, a cyclic amino group (for example, a pyrrolidino group), an acylamino group, an oxycarbonylamino group, a heterocyclic group (5-
A 6-membered nitrogen-containing heterocycle, for example, a benztriazolyl group,
Imidazolyl group, triazolyl group, tetrazolyl group, etc.), ureido group, and sulfonamide group. X and W,
X and R may be bonded to each other to form a cyclic structure. Examples of the ring formed by X and W include pyrazolone, pyrazolidinone, cyclopentanedione, β-ketolactone, β-ketolactam and the like.

The general formula (G) will be further described.
The electron-withdrawing group represented by is a substituent whose substituent constant σp can take a positive value. Specifically, a substituted alkyl group (eg, halogen-substituted alkyl), a substituted alkenyl group (eg, cyanovinyl), a substituted / unsubstituted alkynyl group (eg, trifluoromethylacetylenyl, cyanoacetylenyl),
Substituted aryl group (cyanophenyl, etc.), substituted / unsubstituted heterocyclic group (pyridyl, triazinyl, benzoxazolyl, etc.), halogen atom, cyano group, acyl group (acetyl, trifluoroacetyl, formyl, etc.), thioacetyl group (Thioacetyl, thioformyl, etc.), oxalyl group (methyloxalyl, etc.), oxyoxalyl group (ethoxalyl, etc.), thiooxalyl group (ethylthiooxalyl, etc.), oxamoyl group (methyloxamoyl, etc.), oxycarbonyl group (ethoxycarbonyl, etc.) , Carboxyl group, thiocarbonyl group (such as ethylthiocarbonyl),
Carbamoyl group, thiocarbamoyl group, sulfonyl group,
Sulfinyl group, oxysulfonyl group (ethoxysulfonyl, etc.), thiosulfonyl group (ethylthiosulfonyl, etc.), sulfamoyl group, oxysulfinyl group (methoxysulfinyl, etc.), thiosulfinyl group (methylthiosulfinyl, etc.), sulfinamoyl group, sphinamoyl group, phosphoryl Group, nitro group, imino group, N-carbonylimino group (N-acetylimino, etc.), N-sulfonylimino group (N-methanesulfonylimino, etc.), dicyanoethylene group, ammonium group, sulfonium group, phosphonium group, pyrylium group And an immonium group, and a heterocyclic group in which an ammonium group, a sulfonium group, a phosphonium group, an immonium group, and the like form a ring is also included. A substituent having a σp value of 0.30 or more is particularly preferred.

The alkyl group represented by W is methyl, ethyl, trifluoromethyl and the like, the alkenyl group is vinyl, halogen-substituted vinyl, cyanovinyl and the like, the alkynyl group is acetylenyl and cyanoacetylenyl and the like. Examples of the group include nitrophenyl, cyanophenyl, and pentafluorophenyl, and examples of the heterocyclic group include pyridyl, pyrimidyl, triazinyl, succinimide, tetrazolyl, triazolyl, imidazolyl, and benzoxazolyl. W is σ
A p-value is preferably a positive electron-withdrawing group, and more preferably, the value is 0.30 or more.

Among the above substituents for R, preferably a hydroxy group, a mercapto group, an alkoxy group, an alkylthio group,
Halogen atom, an organic or inorganic salt of a hydroxy group or a mercapto group, and a heterocyclic group, more preferably a hydroxy group, an alkoxy group, an organic or inorganic salt of a hydroxy group or a mercapto group, a heterocyclic group, Particularly preferred is an organic or inorganic salt of a hydroxy group, a hydroxy group or a mercapto group.

Of the above-mentioned X and W substituents, those having a thioether bond in the substituent are preferred. Next, specific examples of the compound represented by the general formula (G) are shown below, but it should not be construed that the invention is limited thereto.

[0059]

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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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[0073]

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[0074]

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[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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[0080]

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[0081]

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[0082]

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In the general formula (P), Q represents a nitrogen atom or a phosphorus atom, R ₁ , R ₂ , R ₃ and R ₄ each represent a hydrogen atom or a substituent, and X ⁻ represents an anion. Note that R _{1 to} R
₄ may be connected to each other to form a ring. Examples of the substituent represented by R _{1 to} R ₄ include an alkyl group (methyl group, ethyl group, propyl group, butyl group, hexyl group, cyclohexyl group, etc.), an alkenyl group (allyl group, butenyl group, etc.),
Alkynyl group (propargyl group, butynyl group, etc.), aryl group (phenyl group, naphthyl group, etc.), heterocyclic group (piperidinyl group, piperazinyl group, morpholinyl group, pyridyl group, furyl group, thienyl group, tetrahydrofuryl group,
Tetrahydrothienyl group, sulfolanyl group, etc.), amino group and the like.

The ring which may be formed by connecting R _{1 to} R ₄ to each other includes a piperidine ring, a morpholine ring, a piperazine ring,
Examples include a quinuclidine ring, a pyridine ring, a pyrrole ring, an imidazole ring, a triazole ring, and a tetrazole ring. The groups represented by R _{1 to} R ₄ are a hydroxyl group, an alkoxy group, an aryloxy group, a carboxyl group, a sulfo group,
It may have a substituent such as an alkyl group and an aryl group.

As R ₁ , R ₂ , R ₃ and R ₄ , a hydrogen atom and an alkyl group are preferred. Examples of the anion represented by X ⁻ include inorganic and organic anions such as a halogen ion, a sulfate ion, a nitrate ion, an acetate ion and a p-toluenesulfonic acid ion. More preferred are compounds represented by the following general formula (Pa), (Pb) or (Pc), and compounds represented by the following general formula [T].

[0086]

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In the formula, A ¹ , A ² , A ³ , A ⁴ and A ⁵ represent a group of nonmetallic atoms for completing a nitrogen-containing heterocyclic ring, and may contain an oxygen atom, a nitrogen atom and a sulfur atom. And the benzene ring may be condensed. A ¹ , A ² , A ³ , A ⁴ and A ⁵
May have a substituent and may be the same or different. Examples of the substituent include an alkyl group, an aryl group, an aralkyl group, an alkenyl group, an alkynyl group, a halogen atom, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a sulfo group, a carboxy group, a hydroxy group, an alkoxy group, and an aryloxy group. , Amide group, sulfamoyl group, carbamoyl group,
Represents a ureido group, amino group, sulfonamide group, sulfonyl group, cyano group, nitro group, mercapto group, alkylthio group and arylthio group. A ¹ , A ² , A ³ , A ⁴ and A
Preferred examples of ⁵ include a 5- to 6-membered ring (each ring of pyridine, imidazole, thiozole, oxazole, pyrazine, pyrimidine and the like), and more preferred examples include a pyridine ring.

B _P represents a divalent linking group, and m represents 0 or 1
Represents Examples of the divalent linking group include an alkylene group, an arylene group, an alkenylene group, —SO ₂ —, —SO—, and —O
—, —S—, —CO—, and —N (R ⁶ ) — (R ⁶ represents an alkyl group, an aryl group, or a hydrogen atom) alone or in combination. Preferred examples of B _p include an alkylene group and an alkenylene group.

R¹, R^TwoAnd R^FiveEach have 1 to 20 carbon atoms
Represents an alkyl group. Also, R¹And R ^TwoAre the same but different
May be. An alkyl group is a substituted or unsubstituted alkyl group.
Represents a kill group, and the substituent is A¹, A^Two, A^Three, A^FourPassing
And A^FiveAre the same as the substituents exemplified as the substituent for. R¹,
R^TwoAnd R^FiveAs a preferred example, each has 4 to 4 carbon atoms.
10 alkyl groups. More preferred examples are
Substituted or unsubstituted aryl-substituted alkyl groups.
You.

[0090] X _p ^- is a counter ion necessary to balance the charge of the whole molecule, for example chloride, bromide,
It represents iodine ion, nitrate ion, sulfate ion, p-toluenesulfonate, oxalate and the like. n _p represents the number of counter ions required to balance the charge of the whole molecule, and n _p is 0 in the case of an internal salt.

[0091]

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The substituents R ₅ and R ₆ of the phenyl group of the triphenyltetrazolium compound represented by the general formula [T],
R ₇ is preferably a hydrogen atom or a compound having a negative Hammett sigma value (σP) indicating electron-withdrawing degree. Hammett's sigma value at the phenyl group has been described in many literatures, for example, Journal of Medical Chemistry (Journa).
l of Medical Chemistry) 20
Vol., Page 304, 1977. Hansch (C.
Hansch), and particularly preferable groups having a negative sigma value include, for example, a methyl group (σP = −0.17 or less and a σP value in any case) and an ethyl group (−
0.15), cyclopropyl group (-0.21), n-propyl group (-0.13), iso-propyl group (-0.
15), cyclobutyl group (-0.15), n-butyl group (-0.16), iso-butyl group (-0.20), n
-Pentyl group (-0.15), cyclohexyl group (-
0.22), amino group (-0.66), acetylamino group (-0.15), hydroxy group (-0.37), methoxy group (-0.27), ethoxy group (-0.24) , Propoxy group (-0.25), butoxy group (-0.3
2), a pentoxy group (-0.34) and the like, all of which are useful as substituents of the compound of the general formula [T].

N represents 1 or 2, and examples of the anion represented by X _T ^n- include halogen ions such as chloride ion, bromide ion and iodide ion, nitric acid, sulfuric acid, and the like.
Acid radicals of inorganic acids such as perchloric acid, acid radicals of organic acids such as sulfonic acid and carboxylic acid, anionic activators, specifically p-
Lower alkylbenzene sulfonic acid anions such as toluene sulfonic acid anion; higher alkyl benzene sulfonic acid anions such as p-dodecyl benzene sulfonic acid anion; higher alkyl sulfate anions such as lauryl sulfate anion; boric acid anions such as tetraphenyl boron; Dialkyl sulfosuccinate anions such as 2-ethylhexyl sulfosuccinate anion,
Examples thereof include higher fatty acid anions such as cetyl polyethenoxy sulfate anion, and polymers having an acid radical attached to a polymer such as polyacrylate anion.

The following are specific examples of the quaternary onium compound, but the invention is not limited thereto.

[0095]

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[0096]

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[0097]

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[0098]

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[0099]

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[0100]

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[0101]

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[0102]

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[0103]

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[0104]

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The above quaternary onium compound can be easily synthesized according to a known method. For example, the above tetrazolium compound is described in Chemical Reviews Vol. 55
p. 335-483 can be referred to. The addition amount of these high contrast agents is 1 × per mole of silver halide.
About 10 ^-8 to 1 mol, preferably 1 × 10 ^-7 to 1 × 10
^-1 mole. These can be added to the light-sensitive material at any time from the time of silver halide grain formation to the time of coating.

The high contrast agents of the present invention may be used alone or in combination of two or more. The compound may be added to any of the constituent layers of the photosensitive material, but is preferably added to at least one of the constituent layers on the side having the photosensitive layer, further to the photosensitive layer and / or an adjacent layer thereof. The photothermographic material according to the invention of claim 4 is characterized in that a heat-treated support is used while being conveyed at a temperature of 80 ° C. or more and 200 ° C. or less and a tension of 4 kPa or less.

The heat treatment of the support in the present invention refers to performing the heat treatment after forming the support or after applying the undercoat layer, and preferably performing the heat treatment after applying the undercoat layer. Here, the term “after applying the undercoat layer” refers to all the steps after the undercoat layer is applied on at least one surface of the support. The tension at the time of heat treatment, preferably at the time of applying an undercoat layer, is 4 kPa or more and
0 kPa or less, more preferably 20 kPa or more and 550 k
Pa or less, more preferably 100 kPa or more and 500 k or more
Pa or less. The tension in the present invention is represented by a value obtained by dividing the force applied to the support by the cross-sectional area (width × thickness) of the support. Such adjustment of the tension can be easily achieved by adjusting the torque of the winding motor and / or the feeding motor. It can also be easily achieved by installing a dancer roll and adjusting the load applied thereto. further,
In order to control the low tension, it is also preferable to measure the amount of thermal shrinkage of the support in advance and reduce the winding amount by an amount corresponding to this amount. By the above method, the tension generated by the heat shrinkage stress is also controlled, so that the treatment with a weaker tension is possible. Further, it is preferable that the width direction is not restricted by a clip or the like, and the support is freely contracted. In order to convey the support with such low tension, it is preferable to use air levitation conveyance other than roll conveyance as much as possible. This is to prevent the occurrence of scratches caused by the reduced roll hold force.

The heat treatment temperature or drying temperature is preferably from 80 ° C. to 200 ° C., more preferably from 90 ° C. to 180 ° C., and further preferably from 100 ° C. to 150 ° C. The drying temperature may be adjusted by using a panel-like heater incorporating a nichrome heater or the like.
A heat source such as a heater may be used, or the heat may be supplied by sending hot air. A temperature sensor is installed in the drying zone to monitor the temperature at various places and adjust the output of these heat sources to control the temperature. For this reason, it is preferable that these heat sources are divided into several parts and have a structure that can be individually controlled in order to suppress temperature non-uniformity. It is preferable to surround the casing for performing the drying treatment with a heat insulating material such as glass wool in order to eliminate temperature unevenness. The drying time is preferably from 1 minute to 30 minutes, more preferably from 2 minutes to 20 minutes, even more preferably from 3 minutes to 15 minutes.

The support used in the present invention may be a plastic film (for example, polyethylene terephthalate, polycarbonate, or the like) in order to prevent deformation of an image after development processing.
Polyimide, nylon, cellulose triacetate, polyethylene naphthalate) are preferred. Particularly preferably used are plastics (hereinafter SPS) containing polyethylene terephthalate (hereinafter abbreviated as PET) and a styrene polymer having a syndiotactic structure.
Abbreviated). The support may have been subjected to surface treatment or undercoating.

The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm. Next, the plastic used in the present invention will be described. PET is made of polyethylene terephthalate in which all polyester components are used. In addition to polyethylene terephthalate, terephthalic acid and naphthalene-2,6 are used as acid components.
-Modified polyester component of dicarboxylic acid, isophthalic acid, butylene dicarboxylic acid, 5-sodium sulfoisophthalic acid, adipic acid, etc. and glycol component such as ethylene glycol, propylene glycol, butanediol, cyclohexane dimethanol, etc. is 10 mol of the total polyester. % Or less.

SPS is a polystyrene having steric regularity unlike ordinary polystyrene (atactic polystyrene). The regular stereoregular structure part of SPS is called a racemo chain, and it is preferable that there are more regular parts such as two, three, five or more. In the present invention, the racemo chain is 2 It is preferably 85% or more in the chain, 75% or more in the three chains, 50% or more in the five chains, and 30% or more in the further chains. The polymerization of SPS can be carried out according to the method described in JP-A-3-131843.

As the method for forming a film and the method for producing an undercoat used in the present invention, known methods can be used, and preferably, paragraph [0030] of JP-A-9-50094 is used.
To [0070].
The photothermographic material of the present invention contains a photosensitive silver halide, an organic silver salt, a reducing agent for silver ions, a binder, and the like, in addition to the above-described high contrast agent.

The photosensitive silver halide grains used in the present invention function as an optical sensor. In the present invention, the average particle size is preferably small in order to suppress white turbidity after image formation and obtain good image quality, and the average particle size is preferably 0.1 μm or less, more preferably 0.01 μm to 0.1 μm. 1 μm, especially 0.02 μm to 0.0
8 μm is preferred. Here, the particle size refers to the diameter (equivalent circle diameter) of a circle having the same area as an individual particle image observed with an electron microscope. Further, the silver halide is preferably monodispersed. Here, the monodispersion means that the degree of monodispersion determined by the following formula is 40% or less. The particle size is more preferably 30% or less, and particularly preferably 20% or less.

Monodispersity = (standard deviation of particle size) / (average value of particle size) × 100 The shape of the photosensitive silver halide grains is not particularly limited, but the proportion occupied by the Miller index [100] plane Is preferably high, and this ratio is preferably 50% or more, more preferably 70% or more, and particularly preferably 80% or more. The ratio of the Miller index [100] plane is [11] in the adsorption of the sensitizing dye.
T] utilizing the adsorption dependency between the [1] plane and the [100] plane. T
ani, J .; Imaging Sci. , 29,165
(1985).

Another preferred form of photosensitive silver halide grains is tabular grains. The term “tabular grains” as used herein means those having an aspect ratio = r / h of 3 or more, where the square root of the projected area is r μm and the vertical thickness is h μm. Among them, the aspect ratio is preferably 3 or more and 50 or less. The particle size is preferably 0.1 μm or less, more preferably 0.01 μm to 0.08 μm
Is preferred. These are disclosed in US Pat. No. 5,264,337.
No. 5,314,798 and 5,320,95
No. 8, etc., and desired tabular grains can be easily obtained.

The halogen composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide, and silver iodide. The photographic emulsion used in the present invention is P.I. Chimie et by Glafkids
Physique Photographique (P
aul Montel, 1967); F. D
Photographic Emuls by uffin
ion Chemistry (The Focal P
Res., 1966); L. Zelikman
Making and Coating by et al
Photographic Emulsion (Th
e Focal Press, 1964) and the like. That is, any of an acidic method, a neutral method, an ammonia method, etc. may be used.
Any of a one-side mixing method, a simultaneous mixing method, a combination thereof and the like may be used.

The silver halide used in the present invention preferably contains metal ions belonging to groups 6 to 11 of the periodic table. As the above metals, W, Fe, Co,
Ni, Cu, Ru, Rh, Pd, Re, Os, Ir, P
t and Au are preferred. These metal ions can be introduced into silver halide in the form of a metal complex or a metal complex ion.
As these metal complexes or metal complex ions, hexacoordinate metal complexes represented by the following general formula are preferable.

In the formula [ML ₆ ] ^m , M is a transition metal selected from elements of Groups 6 to 11 of the periodic table, L is a ligand, and m is 0,-, 2-, 3- or 4-
Represents Specific examples of the ligand represented by L include halides (fluoride, chloride, bromide and iodide), cyanide, cyanate, thiocyanate, selenocyanate, tellurocyanate, azide and aquo. Ligand, nitrosyl, thionitrosyl and the like, preferably aquo, nitrosyl and thionitrosyl. If an aquo ligand is present, it preferably occupies one or two of the ligands. L may be the same or different.

Particularly preferred examples of M are rhodium (Rh), ruthenium (Ru), rhenium (Re), iridium (Ir) and osmium (Os). Hereinafter, specific examples of the transition metal complex ion will be shown, but the present invention is not limited thereto. 1: [RhCl _6] ^3- 2: [RuCl _6] ^3- 3: [ReCl _6] ^3- 4: [RuBr _6] ^3- 5: [OsCl _6] ^3- 6: [IrCl _6] ^4- 7: [Ru (NO) Cl _5] ^2- 8: [RuBr ₄ (H ₂ O)] ^2- 9: _{[Ru (NO) (H 2 O} ) Cl 4 ] ^- 10: [RhCl ₅ (H ₂ O)] ^2- 11: [Re (NO) Cl _5] ^2- 12: [Re (NO) (CN) _5] ^2- 13: [Re (NO) Cl (CN) 4 ] ^2- 14: [Rh (NO) ₂ Cl _4] ^- 15: _{[Rh (NO) (H 2 O} ) Cl 4 ] ^- 16: [Ru (NO) (CN) _5] ^2- 17: [Fe (CN) _6] ^3- 18: [Rh (NS) Cl _5] ^2- 19: [Os (NO) Cl _5] ^2- 20: [Cr (NO) Cl _5] ^2- 21: [Re (NO) Cl _5] ^- 22: [Os (NS) Cl ₄ (TeCN)] ^2- 23: [R (NS) Cl _5] ^2- 24: _{[Re (NS) Cl 4 (SeCN} ) ] ^2- 25: [Os (NS) Cl (SCN) 4 ] ^2- 26: [Ir (NO) Cl _5] ^2- 27: [Ir (NS) Cl _5] ^2- these metal ions may be a metal complex or metal complex ions one type, the metal of the same kind of metal or different may be used alone or in combination. The content of these metal ions, metal complexes or metal complex ions, generally is suitably 1 × 10 ^-9 ~1 × 10 ^-2 mol per mol of silver halide, preferably 1 × 10 ^{- It is 8} to 1 × 10 ^-4 mol.

The compounds providing these metals are preferably added during silver halide grain formation and incorporated into silver halide grains. Preparation of silver halide grains, that is, nucleation, growth, physical ripening, and chemical ripening are carried out. Although it may be added at any stage before and after sensitization, it is particularly preferable to add at the stage of nucleation, growth and physical ripening, more preferably at the stage of nucleation and growth, and most preferably. It is added at the stage of nucleation.

In the addition, the compound may be added in several divided portions, may be added uniformly in the silver halide grains, or may be added uniformly to the silver halide grains.
-306236, 3-167545, 4-76
No. 534, No. 6-110146, No. 5-273683
As described in Japanese Patent Application Laid-Open No. H10-284, etc., the particles can be contained in the particles with a distribution. Preferably, a distribution can be provided inside the particles.

These metal compounds can be added by dissolving them in water or an appropriate organic solvent (eg, alcohols, ethers, glycols, ketones, esters, amides). A method in which an aqueous solution of a powder or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together is added to a water-soluble silver salt solution or a water-soluble halide solution during grain formation, or a silver salt solution and a halide solution are used. When they are mixed simultaneously, they are added as a third aqueous solution to prepare silver halide grains by a three-liquid simultaneous mixing method, a method in which a required amount of an aqueous solution of a metal compound is charged into a reaction vessel during grain formation, or a method in which halogen is added. There is a method in which another silver halide grain doped with metal ions or complex ions in advance during the preparation of silver halide is added and dissolved. In particular, a method of adding an aqueous solution of a powder of a metal compound or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together is added to a water-soluble halide solution.

When adding to the particle surface, a required amount of an aqueous solution of a metal compound can be charged into the reaction vessel immediately after the formation of the particles, during or at the end of physical ripening, or at the time of chemical ripening. In the present invention, the photosensitive silver halide grains may or may not be desalted after grain formation, but when desalting is performed, a method known in the art, such as a noodle method or a flocculation method, may be used. It can be desalted by washing with water.

The photosensitive silver halide grains used in the present invention are preferably chemically sensitized. As a preferred chemical sensitization method, a sulfur sensitization method, a selenium sensitization method, and a tellurium sensitization method are well known in the art. Further, a noble metal sensitization method or a reduction sensitization method of a gold compound, platinum, palladium, an iridium compound or the like can be used.

As the compound preferably used in the above-described sulfur sensitization method, selenium sensitization method, and tellurium sensitization method, known compounds can be used.
Compounds described in No. 8 and the like can be used. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, and P = Te Compounds having a bond, tellurocarboxylates, Te-organyltellurocarboxylates, di (poly) tellurides, tellurides, tellurols, telluroacetals, tellurosulfonates, compounds having a P-Te bond, Te heterocycles, tellurocarbonyl compounds, inorganic tellurium compounds, colloidal tellurium, and the like can be used. Compounds preferably used for the noble metal sensitization method include, for example, chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, gold selenide, US Pat. No. 2,448,060, British Patent No. 618,061 and the like. Can be preferably used.

Specific compounds for the reduction sensitization method include, for example, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds and the like in addition to ascorbic acid and thiourea dioxide. be able to. Further, reduction sensitization can be achieved by ripening the emulsion while maintaining the pH of the emulsion at 7 or more or the pAg at 8.3 or less. Further, reduction sensitization can be achieved by introducing a single addition portion of silver ions during grain formation.

Further, in the present invention, as described in Research Disclosure No. 17029 of June 1978 and US Pat. No. 3,700,458,
A method of forming a photosensitive silver halide by a method of converting a part of the silver of the organic silver salt into a photosensitive silver halide by adding a halogen-containing compound to the organic silver salt is also preferably used.

In the present invention, the organic silver salt is a reducible silver source, and a silver salt of an organic acid or a heteroorganic acid containing a reducible silver ion source, especially a long chain (10 to 30, preferably 15 to 25, And the nitrogen-containing heterocycle is preferred. Organic or inorganic silver salt complexes wherein the ligand has a total stability constant for silver ions of 4.0 to 10.0 are also useful. Examples of suitable silver salts are Research
h Disclosure Nos. 17029 and 29963
And salts thereof: organic acid salts (eg, salts of gallic acid, oxalic acid, behenic acid, arachidic acid, stearic acid, palmitic acid, lauric acid, etc.); silver carboxyalkylthiourea salts (Eg, 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc.); a silver complex of a polymer reaction product of an aldehyde and a hydroxy-substituted aromatic carboxylic acid ( For example, aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.), hydroxy-substituted acids (eg, salicylic acid, benzoic acid, 3,5
-Dihydroxybenzoic acid, 5,5-thiodisalicylic acid), silver salts or complexes of thiones (for example, 3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-2-thione), and 3- Carboxymethyl-4-
Thiazoline-2-thione), imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole, 3-amino-5-benzylthio-1,2,2.
Complexes and salts of silver and a nitrogen acid selected from 4-triazole and benzotriazole; silver salts such as saccharin and 5-chlorosalicylaldoxime; and silver salts of mercaptides. Preferred silver sources are silver behenate, silver arachidate, silver stearate and silver palmitate.

The organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound which forms a complex with silver, but a forward mixing method, a reverse mixing method, a simultaneous mixing method and the like are preferably used. Further, it is also possible to use a controlled double jet method as described in JP-A-9-127463. Specifically, after adding an alkali metal salt (for example, sodium hydroxide, potassium hydroxide, etc.) to an organic acid to prepare an organic acid alkali metal salt soap (for example, sodium behenate, sodium arachidate, etc.),
Silver nitrate is added to the soap to produce organic silver salt crystals. At that time, silver halide grains may be mixed,
The above series of reaction steps need to be performed while stirring sufficiently using a suitable stirring member so that the inside of the reaction tank becomes uniform.

In the present invention, the organic silver salt has an average particle size of 1
It is preferably not more than μm and monodispersed. The average particle size of the organic silver salt refers to the diameter of a sphere equivalent to the volume of the organic silver salt particles when the particles of the organic silver salt are, for example, spherical, rod-shaped, or tabular particles. The average particle size is preferably 0.01 μm to 0.8 μm, particularly 0.05 μm
０．５0.5 μm is preferred. Monodispersion has the same meaning as that of silver halide, and preferably has a monodispersity of 1 to 30.
%. In the present invention, the organic silver salt has an average particle size of 1 μm.
It is more preferable that the particles be monodisperse particles having a particle size of m or less. Further, the organic silver salt preferably has tabular grains having 60% or more of the total organic silver. In the present invention, the term “tabular grains” refers to a ratio of an average particle diameter to a thickness, that is, an aspect ratio (AR) represented by the following formula.
Abbreviation) means three or more.

AR = average particle size (μm) / thickness (μm) The method for obtaining organic silver salt particles having the above-mentioned shape is as follows.
Although not particularly limited, it is effective to optimize various conditions such as a mixed state when forming an organic acid alkali metal salt soap and / or a mixed state when adding silver nitrate to the soap.
It is preferable that the organic silver salt particles used in the present invention are preliminarily dispersed together with a binder, a surfactant, and the like, if necessary, and then dispersed and ground using a media disperser, a high-pressure homogenizer, or the like. For the preliminary dispersion, a general stirrer such as an anchor type or a propeller type, a high-speed rotary centrifugal radiation type stirrer (dissolver), and a high-speed rotary shear type stirrer (homomixer) can be used. Further, as the media dispersing machine, a ball mill, a planetary ball mill, a rolling mill such as a vibrating ball mill, a bead mill as a medium stirring mill, an attritor, and other basket mills can be used, and as a high-pressure homogenizer, a wall mill can be used. Various types can be used, such as a type that collides with a plug or the like, a type in which liquids are divided into a plurality of pieces and then collides with each other at high speed, and a type in which a thin orifice passes.

In the apparatus used for dispersing the organic silver salt particles used in the present invention, ceramics such as zirconia, alumina, silicon nitride and boron nitride and / or Alternatively, it is preferable to use diamond, and particularly preferable to use zirconia. It is very preferable to optimize the binder concentration, the preliminary dispersion method, the operating conditions of the disperser, the number of dispersions, and the like, when performing the above dispersion, as a method for obtaining the organic silver salt particles of the present invention.

The photothermographic material of the present invention preferably contains a reducing agent. Examples of suitable reducing agents are described in U.S. Patent Nos. 3,770,448, 3,773,512,
No. 3,593,863 and Research D
No. 17029 and 29996, and include the following: Aminohydroxycycloalkenones (eg, 2-hydroxypiperidino-2-cyclohexenone); aminoreductones esters (eg, piperidinohexose reductone monoacetate) as precursors of reducing agents; N- Hydroxyurea derivatives (eg, Np-methylphenyl-N-hydroxyurea); hydrazones of aldehydes or ketones (eg, anthracenaldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (E.g., hydroquinone, t-butyl-hydroquinone, isopropylhydroquinone and (2,5-dihydroxy-phenyl) methylsulfone); sulfhydroxamic acids (e.g., benzenesulfhydroxamic acid) ;
Sulfonamidoanilines (eg, 4- (N-methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (eg, 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone); Tetrahydroquinoxalines (Eg, 1,2,3,4-tetrahydroquinoxaline); amideoxins; azines (eg, a combination of an arylcarboxylic acid arylhydrazide and ascorbic acid); a combination of polyhydroxybenzene and hydroxylamine, reductone and / Or hydrazine; hydroxanoic acids; combinations of azines and sulfonamidophenols; α-cyanophenylacetic acid derivatives; combinations of bis-β-naphthol and 1,3-dihydroxybenzene derivatives; 5-pyrazolones; Phenol reducing agents; 2-phenylindane-1,3-dione and the like; chromans; 1,4-dihydropyridines (for example, 2,6-dimethoxy-3,5-
Dicarbethoxy-1,4-dihydropyridine); bisphenols (for example, bis (2-hydroxy-3-t)
-Butyl-5-methylphenyl) methane, bis (6-hydroxy-m-tri) mesitol,
2,2-bis (4-hydroxy-3-methylphenyl)
Propane, 4,5-ethylidene-bis (2-t-butyl-6-methyl) phenol), ultraviolet-sensitive ascorbic acid derivatives and 3-pyrazolidones. Among them, particularly preferred reducing agents are hindered phenols. Examples of the hindered phenols include compounds represented by the following general formula (A).

[0134]

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In the formula, R represents a hydrogen atom or a group having 1 to 1 carbon atoms.
Represents an alkyl group of 10 (eg, butyl group, 2,4,4-trimethylpentyl group, etc.), and R ′ and R ″ represent an alkyl group having 1 to 5 carbon atoms (eg, methyl group, ethyl group, t- Specific examples of the compound represented by the formula (A) are shown below, but the present invention is not limited thereto.

[0136]

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[0137]

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The amount of the reducing agent including the compound represented by formula (A) is preferably 1 × 1 per mol of silver.
It is from 0 ^-2 to 10 mol, especially from 1 x 10 ^{-2 to} 1.5 mol.
The photothermographic material of the present invention may contain an antifoggant. What is known as the most effective antifoggant is mercury ion. The use of a mercury compound as an antifoggant in a light-sensitive material is disclosed in, for example, US Pat. No. 3,589,903. However, mercury compounds are environmentally unfriendly. Examples of the non-mercury antifoggant include, for example, U.S. Pat. Nos. 4,546,075 and 4,452,885 and JP-A-59-57234.
Preferred are antifoggants as disclosed in US Pat.

Particularly preferred non-mercury antifoggants include US Pat. Nos. 3,874,946 and 4,753.
No. 6,999, the compound -C (X
₁ ) Heterocyclic compounds having at least one substituent represented by (X ₂ ) (X ₃ ) (where X ₁ and X ₂ each represent a halogen atom, and X ₃ represents hydrogen or a halogen atom). Can be

Other suitable antifoggants include those described in JP-A-9-288328, paragraph [0030].
To [0036], JP-A-9-9
Compounds described in paragraph Nos. [0062] to [0063] of US Pat. No. 0550, US Pat. No. 5,028,523 and European Patent Nos. 600,587 and 605,981.
Nos. 631,176 and the like can be used.

It is preferred to add a toning agent to the photothermographic material of the present invention for the purpose of improving the silver tone after development. Examples of suitable toning agents are Research Discl
No. 17029, which includes the following: Imides (eg, phthalimide); cyclic imides, pyrazolin-5-ones, and quinazolinones (eg, succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4- Thiazolidinedione); naphthalimides (eg, N-hydroxy-1,8-naphthalimide); cobalt complexes (eg, hexamine trifluoroacetate of cobalt), mercaptans (eg, 3
-Mercapto-1,2,4-triazole); N- (aminomethyl) aryldicarboximides (for example,
N- (dimethylaminomethyl) phthalimide); blocked pyrazoles, isothiuronium (isoth
uronium) derivatives and certain photobleaches (eg, N, N'-hexamethylene (1-carbamoyl-3,5-dimethylpyrazole), 1,8-
A combination of (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzothiazole; a merocyanine dye (e.g., 3-ethyl-5-((3-ethyl -2-benzothiazolinylidene (benzothiazolinylidene))-1-methylethylidene) -2-thio-2,4
Oxazolidinedione); phthalazinone, a phthalazinone derivative or a metal salt of these derivatives (for example, 4-
(1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, and 2,3
-Dihydro-1,4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, 6-chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate); phthalazine + phthalate Combinations of acids; phthalazine (including adducts of phthalazine) and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivatives and anhydrides thereof (for example,
Combination with at least one compound selected from phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride; quinazolinediones, benzoxazine, naloxazine derivatives; benzoxazine-2,4-dione (Eg, 1,3-benzoxazine-2,4-dione); pyrimidines and asymmetric-triazines (eg, 2,4-dihydroxypyrimidine), and tetraazapentalene derivatives (eg,
3,6-dimercapto-1,4-diphenyl-1H, 4
H-2,3a, 5,6a-tetraazapentalene). Preferred toning agents are phthalazone or phthalazine.

The photothermographic materials of the present invention include, for example, JP-A-63-159814, JP-A-60-140335, JP-A-63-231437, JP-A-63-259651, and JP-A-6-259561.
3-304242, 63-15245, U.S. Pat. Nos. 4,639,414 and 4,740,455,
Nos. 4,741,966 and 4,751,175
No. 4,835,096.

Useful sensitizing dyes for use in the present invention include, for example, Research Disclosure Item
17643 IV-A (p. 23, December 1978), and Item 18431 (p. 437, August 1979), etc. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, JP-A-9-34078, JP-A-9-54409, and JP-A-9-806
The compounds described in No. 79 are preferably used.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained in order to control development by suppressing or accelerating development, to improve spectral sensitization efficiency, and to improve storage stability before and after development. be able to. When a mercapto compound is used in the present invention, any structure may be used, but Ar-SM, Ar-SM
Those represented by -SS-Ar are preferred. In the formula, M is a hydrogen atom or an alkali metal atom, and Ar represents an aromatic ring or a condensed aromatic ring having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms.

As the aromatic ring, an aromatic carbon ring and a heteroaromatic ring are used. In the present invention, a heteroaromatic ring is preferably used. As the heteroaromatic ring, for example, benzimidazole, naphthymidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, pyrimidine, Pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring includes, for example, a halogen atom (eg, Br and Cl), a hydroxy group, an amino group, a carboxy group, an alkyl group (eg, one or more carbon atoms, preferably
Having a substituent selected from the group consisting of those having from 1 to 4 carbon atoms) and alkoxy groups (e.g., having at least one carbon atom, preferably having from 1 to 4 carbon atoms). Is also good. Examples of the mercapto-substituted heteroaromatic compound include 2-mercaptobenzimidazole and 2-mercaptobenzimidazole.
Mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzothiazole, 3-mercapto-1,2,4-triazole,
-Mercaptoquinoline, 8-mercaptopurine, 2,
3,5,6-tetrachloro-4-pyridinethiol,
-Hydroxy-2-mercaptopyrimidine, 2-mercapto-4-phenyloxazole and the like,
The present invention is not limited to these.

In the present invention, a matting agent is preferably contained on the photosensitive layer side. In order to prevent damage to the image after thermal development, it is preferable to provide a matting agent on the surface of the photosensitive material. It is preferable that the content of the agent is 0.5 to 30% by weight based on all binders on the emulsion layer side.
In the present specification, mass and weight will be treated as synonyms hereinafter.

The material of the matting agent used in the present invention may be either an organic substance or an inorganic substance. For example, as the inorganic substance, silica described in Swiss Patent No. 330,158 or the like,
Glass powder described in French Patent No. 1,296,995,
Alkaline earth metals or carbonates such as cadmium and zinc described in British Patent No. 1,173,181 can be used as a matting agent. Examples of organic substances include starch described in U.S. Pat. No. 2,322,037, starch derivatives described in Belgian Patent No. 625,451 and British Patent No. 981,198, and Japanese Patent Publication No. 44-3643. Polyvinyl alcohol, Swiss Patent 330,15
An organic matting agent such as polystyrene or polymethacrylate described in No. 8, etc., polyacrylonitrile described in U.S. Pat. No. 3,079,257, etc., and polycarbonate described in U.S. Pat. No. 3,022,169 is used. be able to.

The shape of the matting agent may be either regular or irregular, but is preferably regular and spherical. The size of the matting agent is represented by a diameter when the volume of the matting agent is converted into a sphere. In the present invention, the particle diameter of the matting agent indicates the diameter converted into a sphere.
The matting agent used in the present invention has an average particle size of 0.5 μm
To 10 μm, more preferably 1.
0 μm to 8.0 μm. The matting agent has a coefficient of variation of the particle size distribution of preferably 50% or less, more preferably 40% or less, and particularly preferably 30% or less.

Here, the coefficient of variation of the particle size distribution is a value represented by the following equation. (Standard deviation of particle size) / (average value of particle size) × 100 The matting agent used in the present invention can be contained in any constituent layer, but is preferably photosensitive in order to achieve the object of the present invention. It is a constituent layer other than the functional layer, and is more preferably the outermost layer as viewed from the support.

The method of adding the matting agent used in the present invention may be a method of dispersing in a coating solution in advance and applying the same, or spraying the matting agent after application of the coating solution and before drying is completed. May be used. When a plurality of types of matting agents are added, both methods may be used in combination. In the present invention, a conductive compound such as a metal oxide and / or a conductive polymer can be included in the constituent layer in order to improve the chargeability. These may be contained in any layer, but are preferably contained in an undercoat layer, a backing layer, a layer between the photosensitive layer and the undercoat, and the like. In the present invention, U.S. Pat.
The conductive compound described in No. 20 is preferably used.

Various additives may be added to any of the photosensitive layer, the non-photosensitive layer, and other constituent layers. In the photothermographic material of the present invention, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, a coating aid, and the like may be used in addition to the above. These additives and the other additives mentioned above are used in Research Disclosure.
re Item 17029 (pp. 9-1 on June 1978)
The compounds described in 5) can be preferably used.

The binder suitable for the photothermographic material of the present invention is transparent or translucent, generally colorless, and includes natural polymer synthetic resins, polymers and copolymers, and other film-forming media, for example: gelatin, gum arabic, (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 (vinylacetal) s (eg, poly (vinylformal) and poly (vinylbutyral)), poly (ester) Kind, poly ( Urethane), phenoxy resin, poly (vinylidene chloride), poly (epoxides),
Poly (carbonate) s, poly (vinyl acetate),
There are cellulose esters and poly (amides).

Although it may be hydrophilic or hydrophobic, in the present invention, it is preferable to use a hydrophobic transparent binder in order to reduce fog after thermal development. Preferred binders include polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, polycarbonate, polyacrylic acid, polyurethane and the like. Among them, polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, and polyester are particularly preferably used.

As another preferred binder, a binder which can be dissolved or dispersed in an aqueous solvent (aqueous solvent),
It is a polymer having an equilibrium water content of 2 wt% or less at 60 ° C and 60% RH. When such a polymer is used, a photosensitive layer can be formed using a water solvent containing 30% by weight or more of water as a coating solvent. If the above equilibrium water content exceeds 2 wt%, fog due to storage in a high humidity atmosphere will increase. The aqueous solvent in which the polymer is soluble or dispersible is water or a mixture of water and 70 wt% or less of a water-miscible organic solvent. Examples of the water-miscible organic solvent include alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol; cellosolves such as methyl cellosolve, ethyl cellosolve, and butyl cellosolve; ethyl acetate; and dimethylformamide.

In the case where the polymer is not thermodynamically dissolved but exists in a so-called dispersed state, the term “aqueous solvent” is used here. In the present invention, “equilibrium water content at 25 ° C. and 60% RH” refers to 25 ° C.
It can be expressed as follows using the weight W1 of the polymer that is in a moisture-conditioning equilibrium under an atmosphere of 60% RH and the weight W0 of the polymer that is in an absolutely dry state at 25 ° C. Equilibrium moisture content at 25 ° C. and 60% RH = ｛(W1-W
0) / W0｝ × 100 (wt%) The actual measurement can be performed as shown in Examples described later. The polymer is soluble or dispersible in the above-mentioned aqueous solvent and has an equilibrium water content of 2 wt% at 25 ° C. and 60% RH.
% Is not particularly limited. Among these polymers, polymers that can be dispersed in an aqueous solvent are particularly preferred. Examples of the dispersion state include a latex in which polymer solid fine particles are dispersed and a dispersion in which polymer molecules are dispersed in a molecular state or in the form of micelles.

The equilibrium water content of the above polymer at 25 ° C. and 60% RH needs to be 2 wt% or less.
Preferably, the content is 0.01 wt% or more and 1.5 wt% or less, and more preferably 0.02 wt% or more and 1 wt% or less. Examples of the polymer include an acrylic resin, a polyester resin, a polyurethane resin, a vinyl chloride resin, a vinylidene chloride resin, and a rubber-based resin (for example, SBR resin or N
(BR resin), vinyl acetate resin, polyolefin resin, polyvinyl acetal resin and the like. The polymer may be a homopolymer obtained by polymerizing a single monomer, or 2
It may be a copolymer obtained by polymerizing two or more kinds of polymers. The polymer may be a linear or branched polymer. Further, the polymers may be crosslinked. As the molecular weight of the polymer, the weight average molecular weight Mw is 1
000 to 1,000,000, preferably 3000 to 500
000 is desirable. Those having a molecular weight of less than 1000 generally have low film strength after coating, and may cause inconveniences such as cracks in the photosensitive layer.

In the present invention, specific examples of the above-mentioned polymer which can be used as the main binder of the photosensitive layer include the following. _{P-1 :-( MMA) 50 -} (EA) 45 - (AA) 5 - latex (Mw = 3 million _{in) P-2 :-( 2EHA) 30} - (MMA) 50 - (St) 15
- (MAA) ₅ - latex (Mw = 5 million _{in) P-3 :-( BR) 50} - (St) 47 - (AA) 3 - latex (Mw = 1 million in) P-4 :-( BR) _40- (DVB) _10- (St) _45-
(MAA) ₅ - latex (Mw = 5 million _{in) P-5 :-( VC) 70} - (MMA) 25 - (AA) 5 - latex (Mw = 1.5 million in) P-6 :-( VDC ) _60- (MMA) _30- (EA) _5-
(MAA) _5- Latex (Mw = 80,000) In the above, abbreviations represent structural units derived from the following monomers, and numerical values are wt%.

MMA: methyl methacrylate, EA: ethyl acrylate, AA: acrylic acid, 2EHA: 2-
Ethylhexyl acrylate, St: styrene, MA
A: methacrylic acid, BR: butadiene, DVB: divinylbenzene, VC: vinyl chloride, VDC: vinylidene chloride. Such polymers are also commercially available and the following can be used. For example, as the acrylic resin, Sebian A-4635, 46583, 4601
(Daicel Chemical Industries, Ltd.), Nipol LX
Polyester resins such as 811, 814, 820, 821, and 857 (both manufactured by Nippon Zeon Co., Ltd.) include FI
Netex ES650, 611, 679, 675, 5
25,801,850 (Dai Nippon Ink Chemical Co., Ltd.)
And WDsize WHS (manufactured by Eastman Chemical), such as HYDRAN
AP10, 20, 30, 40, 101H, HYDRAN
Examples of vinylidene chloride resins such as HW301, 310, 350 (all manufactured by Dainippon Ink and Chemicals, Inc.) include L50
2, L513, L123c, L106c, L111, L
114 (manufactured by Asahi Chemical Industry Co., Ltd.); vinyl chloride resins such as G351 and G576 (manufactured by Nippon Zeon Co., Ltd.); and polyolefin resins such as Chemipearl S-120, S-300, SA-100, A-10
0, V-100, V-200 and V-300 (all manufactured by Mitsui Petrochemical Co., Ltd.). In the present invention, these polymers may be used alone as the binder,
More than one kind may be blended and used.

Further, in order to protect the surface of the photosensitive material and prevent abrasion, a non-photosensitive layer may be provided outside the photosensitive layer. The binder used for these non-photosensitive layers may be the same as or different from the binder used for the photosensitive layers. In the present invention, a conductive compound such as a metal oxide and / or a conductive polymer can be included in the constituent layer in order to improve the chargeability. These may be contained in any of the layers, but preferably include an undercoat layer, a backing layer, and a layer between the photosensitive layer and the undercoat layer.

The coating method used in the production of the photothermographic material includes a reverse roll, a gravure roll, an air doctor coater, a blade coater, an air knife coater, and the like.
Squeeze coaters, impregnation coaters, bar coaters, transfer roll coaters, kiss coaters, cast coaters or spray coaters, extrusion coaters, and the like are known.In the present invention, the formation of a constituent layer on a support is performed by an extrusion die coater. It is preferred to do so.

When a protective layer is provided on the photosensitive layer, the coating and drying may be repeated for each layer, but it is preferable to apply a multi-layer coating by a wet-on-wet method and to dry. The method of exposing and recording an image on the photothermographic material according to the present invention includes, for example, a method of directly photographing, a method of exposing through a film using a printer or a enlarger, and a method of exposing an original image using an exposure apparatus such as a copying machine. Scanning and exposing the image information through a slit or the like, and scanning and exposing the image information by emitting a light-emitting diode, various lasers (laser diode, gas laser, etc.) via an electric signal (Japanese Patent Application Laid-Open No. 2-129625, 3-33818
2. Japanese Patent Application No. 4-009388, Japanese Patent Application No. 4-281442
And the method of outputting image information to an image display device such as a CRT, a liquid crystal display, an electroluminescence display, a plasma display, etc., and exposing directly or via an optical system.

As a light source for recording an image on the photothermographic material, natural light, a tungsten lamp, a light emitting diode, a laser light source, a CRT light source, etc., as described above, US Pat. No. 4,500,626, and JP-A-2-053378. issue,
The light source and the exposure method described in JP-A-2-054672 can be used. Alternatively, image exposure can be performed using a wavelength conversion element by combining a non-linear optical material with a light source such as a laser beam.

A semiconductor laser diode is widely used in graphic arts as a photographic recording element in each image forming apparatus. The image forming apparatus typically uses a laser diode having an output of 5 to 250 mW. The use of laser diodes follows from the well-established use of lasers (argon ions, helium neon, etc.) common in silver halide based recording elements.

Typical laser light sources include an argon ion laser, a helium neon laser, and an infrared semiconductor laser diode. These photographic elements are usually designed to produce dots that are fine enough for halftone images. Details of photographic films and papers suitable for optical drawing and scanning applications can be found in Research Disclosure (Resea).
rc Disclosure) 33355 (1992)
January 2011) in columns 11.3 and 11.4.

In the present invention, the exposure is preferably performed by laser scanning exposure, and there is no particular limitation as long as the angle between the exposed surface of the photosensitive material and the scanning laser beam is in the range of 1 to 90 °. The beam spot diameter on the exposed surface of the photosensitive material when the laser beam is scanned on the photosensitive material is preferably 300 μm or less, and is not particularly limited. The exposure in the present invention may use a laser scanning exposure machine that emits a scanning laser beam that is a vertical multi.

As a laser scanning method, there are an outer cylindrical scan, an inner cylindrical scan, and a plane scan. In outer surface cylindrical scanning, laser exposure is performed while rotating a drum around which a recording material is wound around the outer surface, and rotation of the drum is main scanning and movement of laser light is sub scanning. In the inner cylindrical scanning, a recording material is fixed on the inner surface of the drum, a laser beam is irradiated from the inside, and a main scan is performed in the circumferential direction by rotating a part or all of the optical system, and a part of the optical system or Sub-scanning is performed in the axial direction by moving the whole in a straight line parallel to the axis of the drum. In the planar scanning, the main scanning of the laser beam is performed by combining a polygon mirror or a galvanometer mirror with an fθ lens or the like, and the sub-scanning is performed by moving the recording medium.
Outer cylinder scanning and inner cylinder scanning are easier to improve the accuracy of the optical system and are more suitable for high-density recording.

[0167]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto. Example 1 (Preparation of Subbed PET Support) 8 W / m ² ··· on both sides of a biaxially stretched and heat fixed 120 μm thick PET film.
For one minute, and apply the following undercoating coating solution a-1 on one surface so as to have a dry film thickness of 0.8 μm, and dry to form an undercoating layer A-1. The following antistatic coating solution b-1 was applied to a dry film thickness of 0.8 μm and dried to obtain an antistatic subbing layer B-1. << Undercoating liquid a-1 >> Butyl acrylate (30% by weight) t-butyl acrylate (20% by weight) Styrene (25% by weight) 2-hydroxyethyl acrylate (25% by weight) copolymer latex liquid (solid content) (30%) 270 g (C-1) 0.6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g Polystyrene fine particles (average particle diameter 3 μm) 0.05 g Colloidal silica (average particle diameter 90 μm) 0.1 g Water <Sub coating liquid b-1> SnO ₂ / Sb (9/1 weight ratio, average particle size 0.18 μm) Amount to become 200 mg / m ² Butyl acrylate (30% by weight) Styrene (20% by weight) %) Glycidyl acrylate (40% by weight) copolymer latex liquid (solid content 30%) 270 g (C-1) 0.6 g hexamethylene -1,6-bis (ethylene urea) 0.8 g Finished to 1 liter with water. Subsequently, on the upper surfaces of the undercoat layer A-1 and the undercoat layer B-1,
A corona discharge of 8 W / m ² · min. Was performed, and the following lower coating liquid a-2 was coated on the lower coating layer A-1 with a dry film thickness of 0.1 μm.
As the undercoat layer A-2, the undercoat layer B-1 is coated on the undercoat layer B-1 with the following undercoat layer coating solution b-2 so as to have a dry film thickness of 0.8 μm. Coated as B-2. << Coating solution a-2 for lower undercoat >> Gelatin 0.4 g / m ² Weight (C-1) 0.2 g (C-2) 0.2 g (C-3) 0.1 g Silica particles (average particle size) (3 μm) 0.1 g Finished to 1 liter with water << Lower coating solution for upper layer b-2 >> (C-4) 60 g Latex liquid containing (C-5) as a component (solid content 20%) 80 g Ammonium sulfate 0.5 g ( C-6) 12 g Polyethylene glycol (weight average molecular weight 600) 6 g Finished to 1 liter with water.

[0168]

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[0169]

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(Coating on Backing Layer Side) The backing layer 1 shown below was coated on the B-2 layer of the undercoated support described above. << Backing Layer 1 >> Cellulose Acetate 2 g / m ² Antihalation Dye A 0.06 g / m ² Silicon dioxide (particle diameter 5 μm) 40 mg / m ^{2 As a} solvent, methyl ethyl ketone, acetone and methanol were used as appropriate.

[0171]

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(Thermal Relaxation Treatment) The support to which the backing layer 1 was applied was subjected to a thermal relaxation treatment in a heating zone at 150 ° C. at a transport tension of 400 kPa and a transport speed of 20 m / min for a residence time of 2 minutes to obtain a support A. As a comparison, a support B not subjected to the heat relaxation treatment was also prepared. (Preparation of emulsion) << Preparation of silver halide particles A >> 7.5 g of gelatin and 10 mg of potassium bromide are dissolved in 900 ml of pure water, the temperature is adjusted to 35 ° C. and the pH is adjusted to 3.0, and then 74 g of silver nitrate is contained. An aqueous solution containing 370 ml of the aqueous solution and an aqueous solution containing potassium bromide and potassium iodide at a molar ratio of (96/4) was added over 10 minutes by a controlled double jet method while maintaining the pAg at 7.7. Thereafter, 4-hydroxy-6-methyl-1,
0.3 g of 3,3a, 7-tetrazaindene was added and Na was added.
Adjust the pH to 5 with OH and average particle size 0.06μ
m, coefficient of variation of projected diameter area 8%, {100} surface ratio 8
6% of cubic silver iodobromide grains were obtained.

The emulsion was subjected to coagulation sedimentation using a gelatin coagulant, desalted, and then adjusted to pH 5.9 and pAg 7.5 with 0.1 g of phenoxyethanol. Then 60
Temperature, and 2 mg of sodium thiosulfate was added.
After aging for 3 minutes, it was cooled to 38 ° C to complete chemical sensitization.
Silver halide grains A were obtained. << Preparation of Organic Fatty Acid Silver Emulsion A >> 10.6 g of behenic acid was added to 300 ml of water and dissolved by heating at 90 ° C., and 31.1 ml of 1 mol / L sodium hydroxide was added with sufficient stirring. For 1 hour. Then 30 ° C
Then, 7.0 ml of 1 mol / L phosphoric acid was added, and 0.01 g of N-bromosuccinimide was added with sufficient stirring.
Was added. Thereafter, silver halide grains A prepared in advance were added with stirring while heating at 40 ° C. so that the silver amount was 10 mol% with respect to behenic acid.
Further, 25 ml of a 1 mol / L silver nitrate aqueous solution was continuously added over 2 minutes, and the mixture was left as it was for 1 hour with stirring.

To the emulsion, polyvinyl butyral dissolved in ethyl acetate was added, and the mixture was sufficiently stirred and allowed to stand to separate into an ethyl acetate phase containing silver behenate grains and silver halide grains A and an aqueous phase. After removing the aqueous phase, silver behenate grains and silver halide grains A were collected by centrifugation. Thereafter, 20 g of synthetic zeolite A-3 (spherical) manufactured by Tosoh Corporation
And 22 ml of isopropyl alcohol, left for 1 hour and filtered. Further, 3.4 g of polyvinyl butyral and 23 ml of isopropyl alcohol were added, and the mixture was sufficiently stirred and dispersed at 35 ° C. at a high speed to complete the preparation of the organic fatty acid silver emulsion A. << Preparation of Photosensitive Layer Coating Solution 1 >> Photosensitive layer coating solution 1 was prepared as follows.

Organic Fatty Acid Silver Emulsion A 1.4 g (in silver) / m ² Pyridinium hydrobromide perbromide 1.5 × 10 ^-4 mol / m ² Calcium bromide 1.8 × 10 ^-4 mol / m ² 2- (4-chlorobenzoyl) benzoic acid 1.5 × 10 ⁻³ mol / m ² sensitizing dye a 4.2 × 10 ⁻⁶ mol / m ² 2-mercaptobenzimidazole 3.2 × 10 ⁻³ mol / m ² 2-Tribromomethylsulfonylquinoline 6.0 × 10 ^-4 mol / m ² Toning agent (compound shown in Table 1) 0.5 × 10 ^-1 mol / m ^{2 As a} solvent, methyl ethyl ketone, acetone and methanol are appropriately used. Using.

[0176]

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<< Preparation of Surface Protective Layer Coating Solution 1 >> Surface protective layer coating solution 1 was prepared as follows. Cellulose acetate 4 g / m ² 1,1 bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane 4.8 × 10 ⁻³ mol / m ² Phthalazine 3.2 × 10 ⁻³ mol / m ² 4-methylphthalic acid 1.6 × 10 ⁻³ mol / m ² Tetrachlorophthalic acid 7.9 × 10 ⁻⁴ mol / m ² Tetrachlorophthalic anhydride 9.1 × 10 ⁻⁴ mol / m the ^second silicon dioxide (particle diameter 2 [mu] m) 20 mg / m ² solvents were used methyl ethyl ketone, acetone, methanol appropriately. (Coating on photosensitive layer side) Subbing layer A-2 of support A or B prepared above with coating solution 1 of photosensitive layer and coating solution 1 of surface protective layer.
, And samples 1 to 8 were prepared. In addition, about the kind of the support and the contrast agent used in each sample,
It was produced in a combination shown in Table 1 below.

The performance of each of the samples thus obtained was evaluated according to the following method. (Evaluation of Sensitometric Characteristic Value) Each sample was optically exposed for 1.5 × 10 ⁻⁷ seconds using a 780 nm semiconductor laser,
Each of the thermal development processes shown below was performed in a combination shown in Table 1. Measure the density of the developed sample with an optical densitometer (Konica:
PDA-65) to obtain a density D-exposure amount LogE characteristic curve. The sensitivity was defined as the reciprocal of the amount of exposure at which an optical density of 3.0 was obtained.
The relative sensitivity when the sensitivity of -1 was set to 100 was shown. Further, the gradation γ is represented by a gradient (tan.θ) of a straight line connecting the points of density 0.3 and 3.0. << Heat development processing conditions and processing samples >> The heat development processing was performed by the following two types.

Thermal development processing 1: Using samples 1 and 2, 9
After processing at a constant temperature of 0 ° C. for 20 seconds, development was performed at a constant temperature of 120 ° C. for 25 seconds.
It was set to 1. Thermal development processing 2: Using samples 1 to 8, processing was performed by gradually increasing the temperature to 75 to 125 ° C. in 20 seconds, followed by 120 ° C.
Development was performed at a constant temperature for 25 seconds, and the processed samples obtained were designated as 1-2 to 8-2, respectively.

[0180] In both the heat development processing 1 and the heat development processing 2, the transport speed in all the processing steps was 25 mm / sec. (Evaluation of thermal dimensional change rate)
Various types of thermal development processing were performed, and the thermal dimensional change before and after thermal development was measured.

Specifically, the length of the sample before thermal development was set to 23 ° C.
After humidity control for more than 2 hours under 55% RH environment, measure (L1)
After performing the above two types of heat development processing, 23 ° C. and 55% RH
After adjusting the humidity for 2 hours or more under the environment, the measurement was performed again (L2), and the shrinkage ratio (%) was calculated as follows. Thermal dimensional change rate = absolute value (%) of [100 × (L1−L2) / L1] Note that a sample is a 590 mm × 440 mm sheet, and MD (590 mm) in the longitudinal direction and TD (440) in the width direction are used.
mm). (Evaluation of Black Pot Resistance) Each of the unexposed samples was subjected to the two types of heat development processing using an automatic heat developing machine, and the resulting developed samples were visually observed using a 100-fold loupe. The evaluation was performed, and the results were classified into the following five ranks.

5: No black spots occurred 4: Black spots were slightly generated, but no problem in practical use 3: Lower limit level in practical use 2: Impossible in practical use 1: Black spots were generated in the entire visual field and used Impossible level.

In addition, three or more ranks were judged to be practically usable levels. The evaluation result obtained as described above is
It is shown in Table 1 below.

[0184]

[Table 1]

As is clear from Table 1, it is found that the sample subjected to the heat development processing according to the present invention is excellent in sensitivity and gradation γ, and has improved thermal dimensional stability and black spot resistance. In addition, it can be seen that the combination of the support and the high contrast agent according to the present invention has higher sensitivity, higher gradation, and excellent thermal dimensional stability and black pot resistance. Example 2 (Production of PET support coated with backing layer) A corona discharge treatment of 8 W / m ² · min was applied to both sides of a biaxially stretched and heat-fixed PET film having a thickness of 120 µm. Undercoat layers A-1 and A-2 were applied in the same manner as in Example 1, and the following layers were sequentially applied to the opposite surface. << Undercoat layer B-3 >> Styrene / butadiene / hydroxyethyl methacrylate / divinylbenzene = 67/30 / 2.5 / 0.5 (% by weight) 200 mg / m ² matting agent (polymethyl methacrylate, average particle diameter 1 μm) 7 mg / m ² << Undercoat layer B-4 >> Styrene / butadiene / hydroxyethyl methacrylate / divinylbenzene = 67/30 / 2.5 / 0.5 (% by weight) 200 mg / m ² << Backing layer 2 >> Cellulose acetate 2 g / M ² Antihalation dye B 60 mg / m ² Silicon dioxide (average particle size 5 μm) 15 mg / m ^{2 As the} solvent, methyl ethyl ketone, acetone and methanol were used as appropriate.

[0186]

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(Thermal Relaxation Treatment) The support to which the backing layer 2 was applied was subjected to thermal relaxation treatment in a heating zone at 150 ° C. at a transport tension of 400 kPa and a transport speed of 20 m / min for a residence time of 2 minutes to obtain a support C. For comparison, a support D not subjected to the above-mentioned heat relaxation treatment was also produced at the same time. (Preparation of emulsion) << Preparation of silver halide particles B >> 11 g of phthalated gelatin, 30 mg of potassium bromide and 10 mg of sodium benzenethiosulfonate were dissolved in 650 ml of pure water, and the temperature was adjusted to 55 ° C. and the pH was adjusted to 5.0. After that, 18.6g of silver nitrate
159 ml of an aqueous solution containing potassium bromide and pAg
While maintaining at 7.7, the mixture was added by a controlled double jet method over 6 minutes and 30 seconds. Then, 55.5 g of silver nitrate
476 ml of an aqueous solution containing
While maintaining at 7.7, the mixture was added by a controlled double jet method over 28 minutes and 30 seconds. Thereafter, the pH was lowered to cause coagulation and sedimentation, followed by desalting treatment. Compound A 0.17 g, deionized gelatin (calcium content: 20 ppm or less)
23.7 g was added, and the mixture was adjusted to pH 5.9 and pAg 8.0. The obtained particles were cubic particles having an average particle size of 0.11 μm, a variation coefficient of the projected diameter area of 8%, and a {100} plane ratio of 93%. The temperature of the particles thus obtained was raised to 60 ° C., and 76 μmol of sodium benzenethiosulfonate per mol of silver was added. After 3 minutes, 154 μmol of sodium thiosulfate was added. 10
Aged for 0 minutes.

Thereafter, the temperature was maintained at 40 ° C., and sensitizing dye b
Is added to 6.4 × 10 ^-4 mol per mol of silver halide and supersensitizer a is added with stirring at 6.4 × 10 ^-3 mol to 1 mol of silver halide. After 20 minutes, the mixture was rapidly cooled to 30 ° C. to prepare silver halide grains B.

[0189]

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<< Preparation of Dispersion B of Organic Acid Silver >> 770 m of pure water
Then, 39.4 g of behenic acid and 4.4 g of arachidic acid were added and dissolved by heating at 85 ° C., and with sufficient stirring, 103 ml of a 1 mol / L aqueous sodium hydroxide solution was added over 60 minutes and added for 240 minutes. The reaction was carried out, and the temperature was lowered to 75 ° C. Then, 112.5 ml of an aqueous solution of 19.2 g of silver nitrate was added over 45 seconds, the mixture was left as it was for 20 minutes, and the temperature was lowered to 30 ° C. Then, the solid content was separated by absorption filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm.

The solid content thus obtained was handled as a wet cake without drying, and 100 g of dry solid content was obtained.
To a considerable amount of the wet cake, 10 g of polyvinyl alcohol (manufactured by Kuraray Co., Ltd .; PVA-205) and water were added to make the total amount 500 g, and then the mixture was preliminarily dispersed with a homomixer. Next, the pre-dispersed stock solution is dispersed in a dispersing machine (trade name: Microfluidizer M-11OS-EH, manufactured by Microfluidics International Corporation, using G10Z interaction chamber).
Was adjusted to 175 MPa, and the mixture was treated three times to complete the preparation of the organic acid silver microcrystal dispersion B having a volume-weighted average diameter of 0.93 μm. Particle size measurements are available from Malvern
Instruments Ltd. Master Si
Performed at zerX. The cooling operation was performed by installing a coiled heat exchanger before and after the interaction chamber and adjusting the temperature of the refrigerant to a desired dispersion temperature. << Preparation of solid fine particle dispersion of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane >> 1,1-bis (2-hydroxy-3,
5-dimethylphenyl) -3,5,5-trimethylhexane 20 g of MP polymer manufactured by Kuraray Co., Ltd.
After adding 3.0 g of 203 and 77 ml of water, the mixture was stirred well and left as a slurry for 3 hours. After that, 360 g of 0.5 mm zirconia beads were prepared, put into a vessel together with the slurry, and dispersed for 3 hours with a dispersing machine (1 / 4G sand grinder mill: manufactured by IMEX Co., Ltd.) to disperse the reducing agent solid fine particles. Was prepared. The particle size is 8
0 wt% was 0.3 μm or more and 1.0 μm or less. << Preparation of solid fine particle dispersion of tribromomethylphenyl sulfone >> 0.5 g of hydroxypropylmethylcellulose per 30 g of tribromomethylphenylsulfone,
Compound B (0.5 g) and water (88.5 ml) were added, and the mixture was stirred well and left as a slurry for 3 hours. Thereafter, a solid fine particle dispersion of the antifoggant was prepared in the same manner as in the preparation of the reducing agent solid dispersion. As for the particle diameter, 80 wt% was 0.3 μm or more and 1.0 μm or less.

[0192]

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<< Preparation of Photosensitive Layer Coating Solution 2 >> The following binder, material and silver halide particles B were added to 1 mol of silver of the organic acid silver microcrystal dispersion B prepared above, and water was added. In addition, a photosensitive layer coating solution 2 was prepared. Binder; Luck Star 3307B (manufactured by Dainippon Ink and Chemicals, Inc .; glass transition temperature of 17 ° C. with SBR latex) 470 g as solids 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5 1,5-trimethylhexane 110 g as solid content Tribromomethylphenyl sulfone 25 g as solid content Sodium benzenethiosulfonate 0.25 g Polyvinyl alcohol (MP-203 manufactured by Kuraray Co., Ltd.) 46 g Phthalazine 0.12 mol Hardening agent (Table 2) 6.5 × 10 ^-3 mol Dye a 0.62 g Silver halide grains B 0.05 mol as Ag amount

[0194]

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<< Preparation of Surface Protective Layer Coating Solution 2 >> Solid Content 2
7.5% polymer latex (methyl methacrylate / styrene / 2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate / methacrylic acid = 59 /
(9/26/5/1 copolymer with a glass transition temperature of 55 ° C)
3.75 g of water was added to 109 g, and 4.5 g of benzyl alcohol, 0.45 g of compound C, and
0.125 g, 0.0125 mol of 4-methyl-phthalic acid and polyvinyl alcohol (Kuraray Co., Ltd., PVA
-217) 2.25 g was added, and further water was added to add 150 g.
g, and a coating solution 2 for a surface protective layer was prepared.

[0196]

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(Coating of Photosensitive Layer Side) The coating solution 2 of the photosensitive layer and the coating solution 2 of the surface protective layer were simultaneously coated on the undercoat layer A-2 of the support C or D prepared above to prepare samples 9 to 16. Was prepared. In addition, about the support body and the kind of high contrast agent used for each sample, it produced by the combination shown in Table 2 mentioned later.

Each sample obtained as described above was evaluated in the same manner as in Example 1 except for the heat development processing conditions shown below. The obtained results are also shown in Table 2. The sensitivity was expressed as a relative sensitivity with the sensitivity of the heat-developed sample 9-1 set to 100. << Heat development processing conditions >> The heat development processing was performed by the following two types.

Thermal development processing 3: Using samples 9 and 10,
After processing at a constant temperature of 90 ° C. for 15 seconds, development was performed at a constant temperature of 120 ° C. for 20 seconds.
It was set to -1. Thermal development processing 4: 75 to 125 ° C. using samples 9 to 16
The temperature is increased stepwise in 15 seconds until
The developed sample was developed at a constant temperature of 20 ° C. for 20 seconds, and the obtained processed samples were designated as 9-2 to 16-2.

[0200] In both the heat development processing 3 and the heat development processing 4, the transport speed in all the processing steps was 25 mm / sec.

[0201]

[Table 2]

As is clear from Table 2, the sample according to the present invention has high sensitivity, hard gradation, and excellent thermal dimensional stability and black spot resistance.

[0203]

According to the present invention, it is possible to provide a method for processing a photothermographic material having high sensitivity, high gradation, improved thermal dimensional stability, and preventing occurrence of black spots.

Claims (4)

[Claims] In a method for processing a photothermographic material having a photosensitive silver halide, an organic silver salt, a reducing agent for silver ions and a binder on a support, a temperature gradient is represented by the following formula (1). A method for processing a photothermographic material, wherein the processing is performed by using an automatic thermal developing machine having a heating section comprising a portion and a portion where the temperature is kept constant. Formula (1) A = Δt / x In the formula, A represents a temperature gradient (° C./cm), Δt represents a temperature rise (° C.), x represents a transport distance (cm), and the value of A is 0.5
≦ A ≦ 2. 2. The processing speed of the automatic thermal developing machine is 21 mm.
2. The method for processing a photothermographic material according to claim 1, wherein the rate is not less than / sec. 3. The method for processing a photothermographic material according to claim 1, wherein the photothermographic material to be processed contains a high contrast agent. 4. The photothermographic material according to claim 1, wherein said photothermographic material is at least 80.degree.
4. The method according to claim 3, wherein the support is heat-treated at a temperature of not more than 4 kPa while being transported.
A method for processing a photothermographic material according to item 1.