JP2003280138A - Heat-developable photosensitive material and imaging method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-developable recording material for plate making and printing having high contrast gradation, a small increase of fog in long-term storage and good dot quality. <P>SOLUTION: The heat-developable photosensitive material comprises on a support at least an organic silver salt, a photosensitive silver halide, a reducing agent, a binder and a contrast enhancer having a specified structure, wherein at least one of layers formed on the imaging layer side of the support is a layer formed by coating with a coating liquid comprising ≥30 mass% organic solvent and the amount of the residual organic solvent in heat development is 0.1-50 mg/m<SP>2</SP>. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-developable recording material and an image forming method thereof, and more specifically to a heat-sensitive plate-making printing material having a high contrast gradation, low fog density and high sensitivity. The present invention relates to a development recording material and an image forming method thereof.

[0002]

2. Description of the Related Art Various image forming methods for forming an image by exposing a photosensitive material having a photosensitive image forming layer on a support are known. Among them, a method of forming an image by subjecting a light-sensitive material to a heat development treatment is known as a method of contributing to environmental protection and further simplifying an image forming system. In recent years, in the field of photolithography, there has been a strong demand for reducing the amount of processing waste liquid from the viewpoint of environmental protection and space saving. Therefore, the technical development of the photothermographic material for photolithography, which can efficiently expose with a laser scanner or a laser imagesetter and can form a clear black image with high resolution and sharpness, has been made. is necessary. According to such a photothermographic material,
It will be possible to provide customers with a simpler and environmentally friendly thermal development processing system that does not require solution processing chemicals.

A method of forming an image by heat development is disclosed in, for example, US Pat. Nos. 3,152,904 and 3,4.
57,075, and D.L. Cross Tabor (Kl
osterboer) "Thermally Processed Silver Systems A" (Imaging Processes & Materials (Imag)
ing Processes and Materials) Neblette 8th Edition, J.
Sturge, V.I. Walwort
h), A. Edited by Shepp, Chapter 9, page 279,
1989). Such a photothermographic material comprises a reducible non-photosensitive silver source (eg organic silver salt), a catalytically active amount of a photocatalyst (eg silver halide), and a silver reducing agent, usually in an organic binder matrix. It is contained in a state of being dispersed in. The photosensitive material is stable at room temperature, but when it is heated to a high temperature (for example, 80 ° C. or higher) after exposure, silver is reduced through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and the reducing agent. To generate. This redox reaction is promoted by the catalytic action of the latent image formed by exposure. The silver formed by the reaction of the reducible silver salt in the exposed areas turns black and contrasts with the unexposed areas, thus forming an image.

Such a photothermographic material is prepared by coating a support with a coating solution prepared by dissolving various materials in a solvent to form a multilayer including an image forming layer. It An organic solvent such as methyl ethyl ketone or acetone may be used as the solvent of the coating liquid. Japanese Unexamined Patent Publication No. 6-301140 describes that the photographic performance is kept stable by keeping the amount of the residual solvent after coating constant.

On the other hand, a photosensitive material capable of obtaining a high contrast image is required for printing plate making, and a hydrazine derivative as described in US Pat. No. 5,464,738 is used as the contrast increasing technique. Is known to do. However, if these contrast enhancement techniques are adopted,
There is a problem that fog easily rises when the light-sensitive material is stored for a long period of time. Also, if the amount of the inhibitor described in these patents is increased to suppress fog, the halftone dot quality deteriorates. Therefore, there has been a demand for a photothermographic material that has a high contrast, a small increase in fog during long-term storage, and a good halftone dot quality.

[0006]

An object of the present invention is to have a hard gradation and to reduce fog increase during long-term storage,
Another object of the present invention is to provide a heat-developable recording material for plate-making printing, which has good halftone dot quality.

[0007]

Means for Solving the Problems As a result of intensive studies by the present inventors, it was found that the above object can be achieved by the present invention having any of the following constitutions. 1. In a photothermographic material containing at least one organic silver salt, a photosensitive silver halide, a reducing agent and a binder on a support and having at least one image forming layer, the amount of residual organic solvent at the time of heat development is 0.1. ˜50 mg / m ² ,
A photothermographic material comprising at least one compound selected from compounds represented by the following formulas (1) to (6).

[Chemical 7] [Wherein, R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or a monovalent substituent, X ¹¹ represents an electron-donating heterocyclic group, a cycloalkyloxy group, a cycloalkylthio group,
Represents a cycloalkylamino group or a cycloalkenyl group. ]

[Chemical 8] [In the formula, R ²¹ represents an alkyl group, R ²² and R ²³ each independently represent a hydrogen atom or a monovalent substituent, X ²¹ represents an electron-withdrawing group, and L ²¹ represents an aromatic carbocyclic group. Represents n2
Represents 0 or 1. ]

[Chemical 9] [In the formula, X ³¹ represents an electron-withdrawing heterocyclic group, a halogen atom or a haloalkyl group, either R ³¹ or R ³² represents a hydrogen atom, and the other represents a hydroxyl group. ]

[Chemical 10] [In the formula, R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , A ⁴¹ and A ⁴² each independently represent a hydrogen atom or a monovalent substituent, and G ⁴¹ represents a divalent linking group. n4 represents 0 or 1. ]

[Chemical 11] [In the formula, R ⁵¹ , R ^52, and R ⁵³ each independently represent a monovalent substituent. ]

[Chemical 12] [In the formula, Q ⁶¹ represents an atomic group forming an aromatic carbocycle or an aromatic heterocycle, and n 6 represents an integer of 1 to 6. ]

2. 2. The photothermographic material according to 1, wherein at least one of the layers formed on the image forming layer side of the support is a layer formed by applying a coating liquid containing 30% by mass or more of an organic solvent. material. 3. 3. The photothermographic material according to 1 or 2, wherein the amount of residual organic solvent at the time of heat development is 0.1 mg / m ² or more and 25 mg / m ² or less. 4. 3. The photothermographic material according to 1 or 2, wherein the amount of the residual organic solvent at the time of heat development is 0.1 mg / m ² or more and 10 mg / m ² or less. 5. 3. The photothermographic material according to 1 or 2, wherein the amount of the residual organic solvent at the time of heat development is 0.1 mg / m ² or more and 5 mg / m ² or less.

6. Contains methanol as a residual organic solvent during heat development, and the residual methanol amount is 0.1 mg / m
The photothermographic material according to 1 or 2, characterized in that a ² to 10 mg / m ^2. 7. Methanol is contained as a residual organic solvent at the time of heat development, and the residual methanol amount is 0.1 mg / m ^{2 to} 5 mg /
^{3. The} photothermographic material according to 1 or 2, which is m ² . 8. It contains methanol as a residual organic solvent at the time of heat development, and the residual methanol amount is 0.1 mg / m ^{2 to 2} mg /
^{3. The} photothermographic material according to 1 or 2, which is m ² .

9. Includes methyl ethyl ketone as the residual organic solvent during thermal development, the photothermographic material according to 1 or 2, wherein the residual methyl ethyl ketone content is ^{0.1mg / m 2 ~10mg / m 2} . 10. Contains methyl ethyl ketone as a residual organic solvent during thermal development, and the residual methyl ethyl ketone content is 0.1 m.
3. The photothermographic material as described in 1 or 2, which is g / m ^{2 to 5} mg / m ² . 11. Contains methyl ethyl ketone as a residual organic solvent during thermal development, and the residual methyl ethyl ketone content is 0.1 m.
3. The photothermographic material as described in 1 or 2, which has a content of g / m ^{2 to 2} mg / m ² .

12. Includes dimethylacetamide as a residual organic solvent during thermal development, the photothermographic material according to 1 or 2, wherein the residual dimethylacetamide weight of ^{0.1mg / m 2 ~10mg / m 2} . 13. It contains dimethylacetamide as a residual organic solvent at the time of heat development, and the residual dimethylacetamide amount is 0.
The photothermographic material according to 1 or 2, characterized in that a ^{1mg / m 2 ~5mg / m 2} . 14. It contains dimethylacetamide as a residual organic solvent at the time of heat development, and the residual dimethylacetamide amount is 0.
The photothermographic material according to 1 or 2, characterized in that a ^{1mg / m 2 ~2mg / m 2} .

15. Contains at least an organic silver salt, a photosensitive silver halide, a reducing agent and a binder on a support,
In the photothermographic material having at least one image forming layer, at least one of the layers formed on the image forming layer side of the support is formed by applying a coating liquid containing 30% by mass or more of an organic solvent. a layer, the photothermographic material characterized in that the residual organic solvent amount at the time of heat development is ^{0.1mg / m 2 ~5mg / m 2} . 16. 16. The photothermographic material according to 15, wherein at least one of the layers formed on the image forming layer side of the support contains at least one high contrast agent.

17. 17. An auto-processing apparatus for automatically transporting the photothermographic material according to any one of 1 to 16 above, which exposes the photothermographic material to the exposure apparatus, the heat developing machine, and the exposure apparatus and the heat developing machine. In the image forming method of exposing and heat developing with an online system consisting of carriers,
An image forming method, wherein the heat developing machine is provided with a preheating section, a heat developing section, a slow cooling section and a deodorizing device.

18. Processing speed (R ₁ ) of the photothermographic material in the auto carrier, processing speed (R ₂ ) of the photothermographic material in the preheating section of the thermal developing machine, processing of the photothermographic material in the thermal developing section of the thermal developing machine Speed (R ₃ )
The following relational expression: R ₃ > R ₂ ≧ R ₁ is satisfied.

19. The processing speed (R ₃ ) of the photothermographic material in the heat developing section of the heat developing machine is 21 mm / sec to 10 mm.
19. The image forming method as described in 17 or 18, wherein the image forming method is 0 mm / sec. 20. 19. The image forming method as described in 17 or 18, wherein the processing speed (R ₃ ) of the photothermographic material in the heat developing section of the heat developing machine is 27 mm / sec to 50 mm / sec.

21. The light source for exposure by the exposure device is a laser having a wavelength of 750 to 800 nm, and the main scanning speed on the surface of the photothermographic material is 500 m / sec to 1500 m / sec. The image forming method according to item.

22. The light source for exposure by the exposure device is a laser having a wavelength of 750 to 800 nm, and the main scanning speed on the surface of the photothermographic material is 1100 m / sec to 1500 m /
21. The image forming method according to any one of 17 to 20, wherein the image forming method is seconds.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The photothermographic material and the image forming method of the present invention will be described in detail below. In addition, in this specification, "-" is used by the meaning including the numerical value described before and after that as a lower limit and an upper limit.

The photothermographic material of the present invention contains at least an organic silver salt, a photosensitive silver halide, a reducing agent and a binder on a support and has at least one image forming layer. In the present invention, at least 1 on the image forming layer side
It is preferred that the layer contains at least one contrast enhancer. The contrast-increasing agent has a gamma value of 1.
The additive is 5 times or more, preferably 2.0 times or more. Here, the gamma value is the vertical axis density D-the horizontal axis exposure amount Lo.
In the characteristic curve consisting of gE, concentration 0.3 and concentration 3.0
It means the slope when connecting with a straight line. In particular,
(3.0-0.3) / (logarithmic value of exposure amount giving density 3.0-logarithmic value of exposure amount giving density 0.3).

As a contrast-increasing agent, Japanese Patent Application Laid-Open No. 2001-296
Compounds represented by formula (1) described in JP-A No. 629, specifically, compounds represented by [Chemical formula 3] to [Chemical formula 30] described in the same publication are preferably used.

In the present invention, the above formula (1) is used as the contrast increasing agent.
The compounds represented by (6) to (6) are more preferably used.
The compounds represented by formulas (1) to (6) will be described in detail.

First, the electron donating group and the electron withdrawing group referred to in the present invention will be described. The electron-donating group in the present invention is a substituent having a negative Hammett's substituent constant σp, and examples of the electron-donating group include a hydroxyl group (or a salt thereof), an alkoxy group, An aryloxy group, a heterocyclic oxy group, an amino group, an alkylamino group, an arylamino group, a heterocyclic amino group, a heterocyclic group having a negative σp value, or a phenyl group substituted with these electron donating groups, etc. Can be mentioned. The electron-withdrawing group in the present invention is a substituent having a positive Hammett's substituent constant σp, and examples of the electron-withdrawing group include a halogen atom, a cyano group, a nitro group and an alkenyl group. , Alkynyl group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, carbamoyl group, carbonamido group, sulfamoyl group, sulfonamide group, trifluoromethyl group, trichloromethyl group, phosphoryl group, Examples thereof include a carboxy group (or a salt thereof), a sulfo group (or a salt thereof), an imino group, a heterocyclic group in which σp has a positive value, or a phenyl group substituted with an electron-withdrawing group thereof. Hammett's rule is used to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives.
In 935, L. P. A rule of thumb proposed by Hammet, which is widely accepted today. There are σp value and σm value in the substituent constants obtained by the Hammett's rule, and these values are described in many general textbooks, and are described in “Lange's Handbook of Chemistry”.
(By JA Dean) "12th sales, 1979 (Mc Graw-Hill)
And "Chemical Area Extra Number", No. 122, 96-103
Page, 1979 (Nankodo), Chemical Reviews, 9th
Volume 1, pp. 165-195, 1991. The electron-withdrawing group and the electron-donating group in the present invention are defined by the σp value, but are not limited to the substituents having the known values described in the above-mentioned publications.

The compound represented by the formula (1) will be described. In the formula, X ¹¹ represents an electron donating heterocyclic group, a cycloalkyloxy group, a cycloalkylthio group, a cycloalkylamino group or a cycloalkenyl group. As a typical example of the electron-donating heterocycle, “Substituent Constan
ts for Correlation Analysis in Chemistry and
Biology (Corwin Hansch and Albert Leo) ”, pages 66 to 339, σp is a negative heterocycle,
Specific examples of the heterocycle include a piperidinyl group, a pyrrolidinyl group, a morpholino group, a piperazinyl group, a 3-thienyl group, a 2-furyl group, a 3-furyl group and a 2-pyrrolo group. Preferred is a 3-thienyl group, a 2-furyl group or a 3-furyl group. These heterocycles have σ
You may have arbitrary substituents in the range which p does not become 0 or positive.

Specific examples of the cycloalkyloxy group, cycloalkylthio group or cycloalkylamino group include cyclopropyloxy group, cyclopentyloxy group, cyclohexyloxy group, cycloheptyloxy group, cyclopropylthio group and cyclopentyl group. Examples thereof include a thio group, a cyclohexylthio group, a cycloheptylthio group, a cyclopropylmethylamino group, a cyclopentylmethylamino group, a cyclohexylmethylamino group and a cycloheptylmethylamino group. Preferred are cyclopentyloxy group, cyclohexyloxy group, cyclopentylthio group and cyclohexylthio group. Specific examples of the cycloalkenyl group include a cyclopropenyl group, a cyclobutenyl group, a cyclopentenyl group, a cyclohexenyl group, a cycloheptenyl group and the like.
Preferred is a cyclopentenyl group or a cyclohexenyl group.

R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or a monovalent substituent. Examples of the monovalent substituent include an alkyl group, an alkenyl group, an alkynyl group,
Aryl group, heterocyclic group, quaternized nitrogen atom-containing heterocyclic group (for example, pyridinium group), hydroxy group, alkoxy group (for example, group including repeating ethyleneoxy group or propyleneoxy group unit), aryloxy Group, acyloxy group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, urethane group, carboxyl group, imide group, amino group, carbonamide group, sulfonamide group, ureido group, thioureido group, sulfamoylamino Group, semicarbazide group, thiosemicarbazide group, hydrazino group, 4
Ammonio 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) sulfonylureido group, (alkyl or aryl) sulfonylcarbamoyl group, halogen atom, cyano group, nitro group,
Examples thereof include a phosphoric acid amide group.

R ¹¹ is preferably an electron-withdrawing group, more preferably a cyano group. Further, it is preferable that R ¹² is a hydrogen atom and R ¹³ is an electron donating group. Most preferably, R ¹¹ is a cyano group, R ¹² is a hydrogen atom, and R ¹³ is a hydroxyl group.

Specific examples of the compound represented by the formula (1) are shown below, but the compound of the formula (1) usable in the present invention is not limited to these. In the compounds listed below, keto-enol tautomers or cis-trans geometric isomers, if any, are present.

[0028]

[Chemical 13]

[0029]

[Chemical 14]

[0030]

[Chemical 15]

[0031]

[Chemical 16]

[0032]

[Chemical 17]

[0033]

[Chemical 18]

Next, the compound represented by the formula (2)
explain. Where R^{twenty one}Represents an alkyl group, R^{twenty two}and
R^{twenty three}Represents a hydrogen atom or a monovalent substituent, X^{twenty one}Is electronic
Represents an attractive group, L^{twenty one}Represents a carbon aromatic ring group, and n2 represents
Represents 0 or 1. R^{twenty one}Specific examples of the alkyl group represented by
Examples include methyl, ethyl, propyl, iso
Propyl group, butyl group, pentyl group, hexyl group, heptyl group
Examples thereof include a tyl group and an octyl group. Preferably methyl
A group, an ethyl group or a propyl group. R^{twenty two}And R^{twenty three}
When is a monovalent substituent, a specific example is shown in formula (1)
R in¹¹, R ¹², R¹³The same substituents as can be mentioned.
X^{twenty one}In the formula (1), the electron-withdrawing group represented by
X¹¹The electron withdrawing group similar to
It is a group. L^{twenty one}Specific examples of carbon aromatic ring residue represented by
Specific examples include a phenylene group and a naphthylene group.
Be done. Phenylene group and naphthylene group are further alkyl groups
May be replaced. Furthermore, R^{twenty two}Is a hydrogen atom, R^{twenty three}But
It is preferably an electron donating group. Most preferably,
X^{twenty one}Is a cyano group, R^{twenty two}Is a hydrogen atom, R^{twenty three}Is hydroxyl
It is a base.

Specific examples of the compound represented by the formula (2) are shown below, but the compound of the formula (2) usable in the present invention is not limited thereto. In the compounds listed below, keto-enol tautomers or cis-trans geometric isomers, if any, are present.

[0036]

[Chemical 19]

[0037]

[Chemical 20]

Next, the compound represented by the formula (3) will be described. In the formula, X ³¹ represents an electron-withdrawing heterocyclic group, a halogen atom or a haloalkyl group. Typical examples of electron-withdrawing heterocyclic groups include “Substituent Constants
for Correlation Analysis in Chemistryand Bi
66 of "ology (by Corwin Hansch and Albert Leo)"
To 339 is a heterocyclic group having a positive σp, and specific examples thereof include a 2-pyridyl group, a 2-pyrimidyl group,
Examples thereof include a 2-pyrazyl group, a 2-quinazolyl group, a 2-benzothiazolyl group, a 2-benzoxazolyl group. These electron-withdrawing heterocyclic groups may have any substituent as long as σp does not become 0 or negative. Preferred examples of the electron-withdrawing heterocyclic group include 2-pyridyl group and 2-pyridyl group.
It is a pyrimidyl group or a 2-pyrazyl group. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. A preferred example of the halogen atom is a chlorine atom or a bromine atom. Examples of the haloalkyl group include a monochloromethyl group, a dichloromethyl group, a trichloromethyl group, a tribromomethyl group, a trifluoromethyl group, a 1,2-dichloroethyl group and a pentafluoroethyl group. The haloalkyl group is preferably a trichloromethyl group, a tribromomethyl group or a trifluoromethyl group. In formula (3), either R ³¹ or R ³² is a hydrogen atom,
The other is a hydroxyl group.

Specific examples of the compound represented by the formula (3) are shown below, but the compound of the formula (3) usable in the present invention is not limited thereto. In the compounds listed below, keto-enol tautomers or cis-trans geometric isomers, if any, are present.

[0040]

[Chemical 21]

Next, the compound represented by the formula (4) will be described. In the formula, R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , A ⁴¹ and A ⁴² each independently represent a hydrogen atom or a monovalent substituent,
Examples of the monovalent substituent include the same substituents as R ¹¹ , R ¹² and R ¹³ described in the formula (1). A preferred substituent for R ⁴¹ , R ⁴² and R ⁴³ is a substituted or unsubstituted phenyl group. It is preferable that both A ⁴¹ and A ⁴² are hydrogen atoms. G ⁴¹ represents a divalent linking group, and specific examples thereof include a-(CO) p- group and -C (= S)-.
Group, a sulfonyl group, a sulfoxy ^{group, -P (= O) R 45} -
Or an iminomethylene group, p represents an integer of 1 or 2, R ⁴⁵ 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, an amino group. Etc. A preferred example of G ⁴¹ is — (CO) p—
Alternatively, it is a sulfonyl group. n4 represents 0 or 1,
It is preferably 1.

Specific examples of the compound represented by the formula (4) are shown below, but the compound of the formula (4) usable in the present invention is not limited to these.

[0043]

[Chemical formula 22]

[0044]

[Chemical formula 23]

Next, the compound represented by the formula (5) will be described. In the formula, R ⁵¹ , R ⁵² and R ⁵³ each independently represent a monovalent substituent. Examples of the monovalent substituent include the same substituents as R ¹¹ , R ¹² and R ¹³ in the formula (1), preferably at least one of R ⁵¹ , R ⁵² and R ⁵³ is an electron-withdrawing group. And more preferably, the electron-withdrawing group is a cyano group.

Specific examples of the compound represented by the formula (5) are shown below, but the compound of the formula (5) usable in the present invention is not limited thereto.

[0047]

[Chemical formula 24]

Next, the compound represented by the formula (6) will be described. In the formula, Q ⁶¹ is an atomic group forming an aromatic carbocycle or an aromatic heterocycle, preferably a 6-membered aromatic carbocycle or a 6-membered aromatic heterocycle. Specific aromatic carbocycles or aromatic heterocycles formed include benzene ring, naphthalene ring, imidazole ring, thiazole ring, benzoxazole ring, pyridine ring, pyrrole ring,
An indole ring, a pyrimidine ring and the like can be mentioned, and a benzene ring, a naphthalene ring and a pyridine ring are preferable. n6 represents an integer of 1 to 6, preferably 1 or 2. Further, the aromatic carbocycle or the aromatic heterocycle formed by Q ⁶¹ may further have a substituent. Examples of the substituent include the monovalent substituent represented by the formula (1).

Specific examples of the compound represented by the formula (6) are shown below, but the compound of the formula (6) usable in the present invention is not limited thereto.

[0050]

[Chemical 25]

[0051]

[Chemical formula 26]

[0052]

[Chemical 27]

Among the compounds represented by the formula (6), the compound represented by the formula (7) is preferable.

[0054]

[Chemical 28] In the formula, Q⁷¹Forms an aromatic carbocycle or an aromatic heterocycle
Represents an atomic group that ⁷¹And R⁷²At least one of
Represents an electron-withdrawing group. n7 represents an integer of 1 to 6.

In equation (7), Q⁷¹Is in equation (6)
Q⁶¹Is synonymous with. R⁷¹And R ⁷²At least one of
Is an electron-withdrawing group, more preferably R⁷¹And R
⁷²At least one of is a cyano group. n
7 represents an integer of 1 to 6, preferably 1 or 2.
It

Specific examples of the compound represented by the formula (7) are shown below, but the compound of the formula (7) usable in the present invention is not limited thereto.

[0057]

[Chemical 29]

The compound most preferably used among the compounds represented by the above formulas (1) to (7) is the compound represented by the formula (2).

The compounds represented by the formulas (1) to (7) according to the present invention include compounds which can be easily synthesized by known methods and which can be purchased directly from drug makers.

The addition layer of the compounds represented by the formulas (1) to (7) is preferably a photosensitive layer containing a silver halide emulsion and / or a layer adjacent to the photosensitive layer. Further, the addition amount of the compound according to the present invention varies depending on the grain size of the silver halide grain, the halogen composition, the degree of chemical sensitization, the type of the inhibitor, etc., and is not uniform, but is generally silver halide. It is preferably in the range of about 10 ^-6 mol to 10 ^-1 mol per mol, particularly 10 ^-5 mol to 10 ^-2 mol.

The compounds represented by the formulas (1) to (7) according to the present invention are suitable organic solvents such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), It can be used by dissolving it in dimethylformamide, dimethylsulfoxide, methylcellosolve and the like. It can also be incorporated by the well-known emulsion dispersion method. For example, dibutyl phthalate, tricresyl phosphate, dissolved using a high boiling point organic solvent such as glyceryl triacetate or diethyl phthalate and an auxiliary solvent such as ethyl acetate or cyclohexanone, mechanically emulsified to produce an emulsion dispersion, It can be added to a desired constituent layer. In addition, a method known as a solid dispersion method, for example, a powder of the compound represented by the formulas (1) to (7) is dispersed in an aqueous system by using a dispersing means such as a ball mill, a colloid mill, or an ultrasonic disperser. It may be optionally added as a fine particle dispersion.

The non-photosensitive organic silver salt used in the photothermographic material of the present invention is a reducible silver source, and a silver salt of an organic acid or a heteroorganic acid containing a reducible silver ion source, particularly a long chain. Aliphatic carboxylic acids (having 10 to 30, preferably 15 to 25 carbon atoms) and heterocyclic carboxylic acids having a nitrogen-containing heterocycle are preferably used. Also useful are organic or inorganic silver salt complexes in which the ligand has a total stability constant for silver ions of 4.0 to 10.0.

Examples of the non-photosensitive organic acid silver salt preferably used in the present invention include Research Disclosure (hereinafter also simply referred to as RD) Nos. 17029 and 29963.
And the following: silver salts of fatty acids (eg gallic acid, oxalic acid, behenic acid, arachidic acid,
Stearic acid, palmitic acid, lauric acid and other silver salts);
A carboxyalkyl thiourea salt of silver (for example, 1- (3
-Carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc.); a silver complex of a polymerization reaction product of an aldehyde and a hydroxy-substituted aromatic carboxylic acid (for example, aldehydes (formaldehyde, Acetaldehyde, butyraldehyde, etc.) and hydroxy-substituted aromatic carboxylic acids (for example, salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid, etc.) polymerization reaction product silver complex), 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-1,2,4. Complexes or salts of silver with a nitrogen acid selected from triazoles and benzotriazoles; silver salts such as saccharin, 5-chlorosalicylaldoxime; and silver salts of mercaptan derivatives. Among the organic silver salts described above, silver salts of fatty acids are preferably used, and silver behenate, silver arachidate and / or silver stearate are more preferably used.

The organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound which forms a complex with silver, and the forward mixing method, the reverse mixing method, the simultaneous mixing method and the like are preferably used. It is also possible to use a controlled double jet method as described in JP-A-9-127643.

Specifically, an organic acid alkali metal salt soap (eg, sodium behenate, sodium arachidate, etc.) was prepared by adding an alkali metal salt (eg, sodium hydroxide, potassium hydroxide, etc.) to an organic acid. later,
Silver nitrate is added to the soap to produce organic silver salt crystals. At that time, silver halide grains may be mixed,
It is necessary to carry out the above-mentioned series of reaction steps while sufficiently stirring so that the inside of the reaction vessel becomes uniform by using an appropriate stirring member.

Usually, the organic silver salt grains contained in the heat-developable recording material are formed in an aqueous mother liquor, and in many cases, they are mixed with preformed silver halide grains. The most general outline of the production process is to remove the mother liquor by centrifugal dehydration or the like to obtain a slurry or a wet cake. Then, a dry powder is formed through a drying process, dispersed in an organic solvent and / or a binder, and prepared and then applied to a support. In addition, the conventionally known organic silver composition for heat-development recording material can be produced in the atmosphere. In the present invention, it is preferable to carry out the liquid preparation step in a high nitrogen concentration atmosphere from the viewpoints of storage stability, particularly improvement of image storability after heat development, in addition to suppression of fog and high sensitivity. Further, as the drying device, a vacuum dryer,
There are freeze dryers, hot air heating type box dryers, airflow dryers, spray dryers, and the like, and airflow dryers are particularly preferably used in the present invention. As the air flow type dryer, a straight pipe type, a type in which a middle cylinder is enlarged to increase the residence time, a swirling flow type, and the like, and a swirling flow type is preferably used. In addition, as the airflow velocity when operating the airflow type dryer,
2.0 N · m ³ / min or more is preferable, 5.0 N · m ³
/ Min or more is more preferable, and further 8.0 N · m ³
/ Min or more is preferable. Furthermore, the hot air temperature is 20
C. or higher is preferable, 40.degree. C. or higher is more preferable, and 60.degree. C. or higher is further preferable. The drying operation is
It may be performed twice or more from the viewpoint of preventing overdrying.

Next, the photosensitive silver halide used in the present invention will be described. The photosensitive silver halide used in the present invention functions as an optical sensor. In the present invention, in order to suppress white turbidity after image formation to a low level and to obtain good image quality, the photosensitive silver halide grains preferably have a small average grain size, and the average grain size is 0.1 μm or less, more preferably Is preferably 0.01 μm to 0.1 μm, particularly preferably 0.02 μm to 0.08 μm. The particle size as used herein refers to the diameter of a circle (equivalent circle diameter) having the same area as each particle image observed with an electron microscope. The silver halide is preferably monodisperse. The monodispersion as used herein means that the monodispersity calculated by the following formula is 40% or less. The particles are more preferably 30% or less, and particularly preferably 20% or less.

Monodispersity = (standard deviation of particle size) /
(Average value of grain size) × 100 The shape of the silver halide grain is not particularly limited, but it is preferable that the ratio of Miller index [100] faces is high, and the ratio is 50% or more, and further 70%. More preferably, it is 80% or more. The ratio of Miller index [100] faces is [11] in the adsorption of sensitizing dyes.
T. Tan using the adsorption dependence of 1] and [100] planes
i, J. Imaging Sci., 29, 165 (1985).

Another preferred silver halide shape is a tabular grain. The tabular grains referred to here are the square root of the projected area, the grain size is rμm, and the vertical thickness is h.
When the thickness is μm, it means that the aspect ratio represented by r / h is 3 or more. Among them, the aspect ratio is preferably 3 or more and 50 or less. The particle size is 0.1 μm
It is preferably not more than 0.01 μm to 0.1 μm.
08 μm is preferable. These are US Pat. No. 5,264,
No. 337, No. 5,314, 798, No. 5, 32
The target tabular grains can be easily obtained as described in each specification such as No. 0958.

The halogen composition is not particularly limited,
It 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 Chimie et Physique Photogr by P. Glafkides.
aphique (Paul Montel, 1967), GF Duffin Pho
tographic Emulsion Chemistry (The Focal Press
, 1966), by VL Zelikman et al Making and Coat
ing Photographic Emulsion (The Focal Press, 19
64) and the like. That is, any of an acidic method, a neutral method, an ammonia method and the like may be used, and as a formation for reacting a soluble silver salt and a soluble halogen salt, any one of a one-sided mixing method, a simultaneous mixing method, a combination thereof and the like may be used. Good.

The silver halide used in the present invention preferably contains metal ions belonging to Groups 6 to 11 of the periodic table. The above metals include W, Fe, Co,
Ni, Cu, Ru, Rh, Pd, Re, Os, Ir, P
t and Au are preferred.

These metal ions can be introduced into the silver halide in the form of metal complexes or metal complex ions. As the metal complex or metal complex ion, a hexacoordinated metal complex represented by the following formula is preferable.

[0073] [ML _6] ^m wherein the transition metal M is selected from 6-11 group elements of the periodic table, L is a ligand, 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 aco. Order,
Nitrosyl, thionitrosyl and the like can be mentioned, with preference given to ako, nitrosyl and thionitrosyl. When an aco ligand is present, it preferably occupies one or two of the ligands. L may be the same or different. Particularly preferred specific examples of M include rhodium (Rh), ruthenium (Ru), rhenium (Re),
Iridium (Ir) and osmium (Os).

Specific examples of transition metal complex ions are shown below, but the 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: [Ru (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, metal complexes or metal complex ions may be used alone or in combination of two or more of the same kind of metal and different kinds of metal. As the content of these metal ions, metal complexes or metal complex ions,
Generally, 1 × 10 ^-9 to 1 per mol of silver halide
× 10 ^-2 mol is suitable, preferably 1 × 10 ^-8 ~
It is 1 × 10 ⁻⁴ mol.

The compounds providing these metals are preferably added at the time of forming the silver halide grains and incorporated into the silver halide grains. Preparation of the silver halide grains, that is, nucleation, growth, physical ripening, chemical It may be added at any stage before and after the sensitization, but it is particularly preferable to add it 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.

Upon addition, the silver halide grains may be added dividedly over several times, or may be incorporated uniformly in the silver halide grains. JP-A-63-29603 and JP-A-2-306236. As described in JP-A Nos. 3-167545, 4-76534, 6-110146, and 5-273683, the particles can be contained with a distribution. . Preferably, it can have a distribution inside the particles.

These metal compounds can be added after being dissolved in water or a suitable organic solvent (eg alcohols, ethers, glycols, ketones, esters, amides). A method of adding an aqueous solution of the powder of 1) or an aqueous solution in which a metal compound and NaCl, KCl are dissolved together 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. When mixed at the same time, it is added as a third aqueous solution to prepare silver halide grains by a three-liquid simultaneous mixing method, a method in which a necessary amount of an aqueous solution of a metal compound is charged into a reaction vessel during grain formation, or a halogen There is a method of adding and dissolving another silver halide grain which has been previously doped with a metal ion or a complex ion at the time of preparing the silver halide. 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 or KCl are dissolved together to a water-soluble halide solution is preferable.

When added to the surface of particles, a necessary amount of an aqueous solution of a metal compound may be added to the reaction vessel immediately after particle formation, during or during physical ripening, or at the time of chemical ripening.

In the present invention, the photosensitive silver halide grain may or may not be desalted after grain formation, but when desalting is performed, it is known in the art such as noodle method and flocculation method. It can be desalted by washing with water according to the method described above.

The photosensitive silver halide grains used in the present invention are preferably chemically sensitized. As a preferable chemical sensitization method, as well known in the art,
A sulfur sensitization method, a selenium sensitization method, or a tellurium sensitization method can be used. Further, a noble metal sensitization method such as a gold compound, platinum, palladium, or iridium compound, or a reduction sensitization method can be applied.

Known compounds can be used as the compounds preferably used in the sulfur sensitizing method, the selenium sensitizing method, and the tellurium sensitizing method, and the compounds described in JP-A-7-128768 are used. be able to. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, P = Compounds having a Te bond, tellurocarboxylates, Te-organyl tellurocarboxylic acid esters, di (poly) tellurides, tellurides, tellurols, telluroacetals, tellurosulfonates, compounds having a P-Te bond , Te-containing heterocycles, tellurocarbonyl compounds, inorganic tellurium compounds, colloidal tellurium and the like can be used.

The compound preferably used in the noble metal sensitization method is, for example, chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, gold selenide, or US Pat. No. 2,448,060, United Kingdom. The compounds described in Japanese Patent No. 618,061 and the like can be preferably used.

Specific compounds used in the reduction sensitization method include ascorbic acid and thiourea dioxide, as well as stannous chloride, aminoiminomethanesulfinic acid,
Examples thereof include hydrazine derivatives, borane compounds, silane compounds and polyamine compounds. Also, the emulsion p
Reduction sensitization can be carried out by aging while maintaining H at 7 or more or pAg at 8.3 or less. Further, reduction sensitization can be performed by introducing a single addition portion of silver ions during grain formation.

A reducing agent is incorporated in the photothermographic material of the present invention. Examples of suitable reducing agents are described in US Pat. No. 3,773.
No. 0,448, No. 3,773,512, No. 3,593,863, and RD No. 1
7029 and 29963, including: Aminohydroxycycloalkenone compounds (for example, 2-hydroxypiperidino-2-cyclohexenone); Amino reductones esters (for example, piperidinohexose reductone monoacetate) as a precursor of a reducing agent; N- Hydroxyurea derivatives (eg N-p-methylphenyl-N-hydroxyurea); Aldehyde or ketone hydrazones (eg anthracene aldehyde phenylhydrazone);
Phosphoramidophenols; Phosphoramidoanilines; Polyhydroxybenzenes (eg, hydroquinone, tert-butyl-hydroquinone, isopropylhydroquinone and (2,5-dihydroxy-phenyl) methylsulfone); Sulfhydroxamic acids (eg, Benzenesulfhydroxamic acid); sulfonamide anilines (for example, 4- (N-methanesulfonamide) aniline); 2-tetrazolylthiohydroquinones (for example, 2-methyl-5- (1-phenyl-5-tetrazolylthio) ) Hydroquinone); Tetrahydroquinoxalines (for example, 1,2,3,4-tetrahydroquinoxaline); Amidooxines; Azines (for example, a combination of aliphatic carboxylic acid aryl hydrazides and ascorbic acid); The combination of mud carboxymethyl benzene and hydroxylamine, reductone or hydrazine;
Hydroxane acids; Combination of azines and sulfonamide phenols; α-Cyanophenylacetic acid derivative; Combination of bis-β-naphthol and 1,3-dihydroxybenzene derivative; 5-Pyrazolones; Sulfonamidephenol reducing agent; 2-Phenyl Indane-1,3-dione and the like; chroman; 1,4-dihydropyridines (eg, 2,6-dimethoxy-3,5-dicarbethoxy-
1,4-dihydropyridine); bisphenols (for example, bis (2-hydroxy-3-tert-butyl-5)
-Methylphenyl) methane, bis (6-hydroxy-m
-Tri) mesitol, 2,2-bis (4-
Hydroxy-3-methylphenyl) propane, 4,5-
Ethylidene-bis (2-tert-butyl-6-methyl) phenol), UV-sensitive ascorbic acid derivatives and 3-pyrazolidones. Among them, particularly preferable reducing agents are hindered phenols.

As the hindered phenols, Japanese Patent Application No. 2
The compound represented by formula (A) described in the specification of No. 002-14437 is preferably used. Specifically, compounds A-1 to A-7 described in the same specification are preferably used.

The amount of these reducing agents used is preferably 1 part of silver.
1 × 10 ^{−2 to} 10 mol per mol, particularly preferably 1
× 10 ^{-2 to} 1.5 mol.

In the present invention, for example, JP-A-63-1
59841, 60-140335, and 6
No. 3-231437, No. 63-259651, No. 63-304242, No. 63-15245.
No. 4,639,414, 4,740,455, and 4,741,966.
No. 4,751,175, No. 4,
The sensitizing dyes described in 835,096 can be used.

The useful sensitizing dyes used in the present invention are described or referred to, for example, in RD Item 17643 IV-A (Dec. 1978, p. 23), Item 18431 (Aug. 1979, p. 437) and the like. Described in the literature. 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, with respect to an argon ion laser light source, JP-A-60-162247 and JP-A-2-48 are available.
635, U.S. Pat. No. 2,161,331, West German Patent No. 936,071, and Japanese Patent Laid-Open No. 5-1.
For the simple merocyanines and the helium neon laser light source described in JP-A-1389, etc., JP-A-50-6
No. 2425, No. 54-18726, No. 59-
JP-A-48-42172 and 51-51 for the trinuclear cyanine dyes described in JP-A-102229, the merocyanines described in JP-A-7-287338, the LED light source and the infrared semiconductor laser light source. -9609, 55-39818, and JP-A-62-284.
For the thiacarbocyanines and infrared semiconductor laser light sources described in JP-A No. 343 and JP-A No. 2-105135, JP-A-59-191032 and JP-A-6060.
Tricarbocyanines described in JP-A-80841, JP-A-59-192242 and JP-A-3-67.
The dicarbocyanines containing a 4-quinoline nucleus described in the general formulas (IIIa) and (IIIb) of JP-A No. 242 are advantageously selected. Furthermore, the wavelength of the infrared laser light source is 75
In the case of 0 nm or more, more preferably 800 nm or more, in order to deal with the laser having such a wavelength range, JP-A-4-182639 and JP-A-5-341432,
JP-A-6-52387, JP-A-3-10931, US Pat. No. 5,441,866, JP-A-7-
The sensitizing dyes described in JP-A-13295 and the like are preferably used. These sensitizing dyes may be used alone, and a combination of sensitizing dyes is often used particularly for the purpose of supersensitization. Along with the sensitizing dye, a dye that does not itself have a spectral sensitizing effect or a substance that does not substantially absorb visible light and exhibits supersensitization may be included in the emulsion.

In the present invention, mercapto is used for suppressing or accelerating and controlling the development, for improving the spectral sensitization rate like the above-described supersensitization, or for improving the preservability before and after the development. A compound, a disulfide compound, and a thione compound can be contained. In the present invention, when a mercapto compound is used, it may have any structure, but Ar-SM, Ar-SSA
Those represented by r are preferred. In the formula, M is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring group or a condensed aromatic ring group having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably, the heteroaromatic ring in these groups is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole,
Benzoxazole, naphthoxazole, benzoselenazole, benzoterrazole, imidazole, oxazole, pyrazole, triazole, thiadiazole,
Tetrazole, triazine, pyrimidine, pyridazine,
Pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring is, for example, halogen (eg Br and Cl), hydroxy, amino, carboxy, alkyl (eg having 1 or more carbon atoms, preferably 1 to 4 carbon atoms) and alkoxy ( For example, it may have one selected from the group of substituents consisting of one or more carbon atoms, preferably having 1 to 4 carbon atoms). As the mercapto-substituted heteroaromatic compound, 2-mercaptobenzimidazole, 2
-Mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole, 6-ethoxy-2-mercaptobenzothiazole, 2,2'-dithiobis-benzothiazole, 3-
Mercapto-1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1-ethyl-2-mercaptobenzimidazole, 2-mercaptoquinoline, 8-mercaptopurine, 2-mercapto- 4 (3H) -quinazolinone, 7-
Trifluoromethyl-4-quinolinethiol, 2,3
5,6-Tetrachloro-4-pyridinethiol, 4-amino-6-hydroxy-2-mercaptopyrimidine monohydrate, 2-amino-5-mercapto-1,3,4
-Thiadiazole, 3-amino-5-mercapto-1,
2,4-triazole, 4-hydroxy-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-diamino-2-mercaptopyrimidine, 2-mercapto-
4-methylpyrimidine hydrochloride, 3-mercapto-5-phenyl-1,2,4-triazole, 2-mercapto-4-phenyloxazole and the like can be mentioned, but not limited thereto. The addition amount of these mercapto compounds is preferably in the range of 0.001 to 1.0 mol per 1 mol of silver in the image forming layer, and more preferably 0.01 to 0.3 mol per 1 mol of silver.
Is the amount of.

Binders suitable in the present invention are transparent or translucent and generally colorless, and include natural and synthetic polymers and copolymers, as well as film-forming media such as gelatin, gum arabic, polyvinyl alcohol, hydroxyethyl cellulose, Cellulose acetate, cellulose acetate butyrate, polyvinylpyrrolidone, casein, starch, polyacrylic acid, polymethylmethacrylate, polymethacrylic acid, polyvinyl chloride, copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene) −
Butadiene), polyvinyl acetals such as polyvinyl formal, polyvinyl butyral, polyesters, polyurethanes, phenoxy resins, polyvinylidene chloride, polyepoxides, polycarbonates, polyvinyl acetates, cellulose esters, polyamides, etc. It may be non-hydrophilic.

Further, for the purpose of protecting the surface of the heat-developable recording material of the present invention and preventing scratches, a non-photosensitive layer can be provided outside the image forming layer. The binder used in these non-photosensitive layers may be the same type or different types as the binder used in the image forming layer.

In the present invention, the binder amount in the image forming layer is 1.5 to 10 g / m in order to accelerate the heat development rate.
It is preferably ² . More preferably 1.7-8
It is g / m ² . If it is less than 1.5 g / m ² , the density of the unexposed area increases significantly and it may not be usable, which is not preferable.

In the present invention, it is desirable to use a color tone agent, a color tone imparting agent, an additive called a toner (hereinafter referred to as a color tone agent), etc., together with the above-mentioned components.
The toning agent has a function of participating in the redox reaction between the non-photosensitive organic silver salt and the reducing agent to make the resulting silver image a dark color, particularly black. Examples of suitable toning agents for use in the present invention are RD
No. 17029, which is as follows. 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 (for example, N-hydroxy-1,8-naphthalimide); cobalt complexes (for example, hexaminetrifluoroacetate of cobalt), mercaptans (for example, 3-mercapto-1,2,4-triazole). ); N- (aminomethyl) aryldicarboximides (eg, N- (dimethylaminomethyl) phthalimide); combinations of blocked pyrazoles, isothiuronium derivatives and certain photobleaches (eg,
N, N'-hexamethylene (1-carbamoyl-3,5
-Dimethylpyrazole), 1,8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate), and 2- (tribromomethylsulfonyl) benzothiazole); a merocyanine dye (eg, 3- Ethyl-5-((3-ethyl-2-benzothiazolinylidene (benzothiazolinylidene))-1-methylethylidene) -2-thio-2,4-oxazolidinedione); phthalazinone, phthalazinone derivative or these Metal salts of derivatives of (eg, 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); a combination of phthalazine + phthalic acid Phthalazine (including adduct of phthalazine) and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivative and its anhydride (for example, phthalic acid,
4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride) in combination with at least one compound; quinazolinediones, benzoxazine, naltoxazine derivatives; benzoxazine-2,4-diones (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). A preferred color tone agent is phthalazone or phthalazine.

In the heat-developable recording material of the present invention, it is preferable to have a crosslinking agent in order to maintain the strength of the coating film.
At the same time, although it is unclear mechanically, it has a good effect on the reduction of fog or the storage stability.

As the cross-linking agent used in the present invention, various cross-linking agents conventionally used for photographic light-sensitive materials, for example, aldehyde type, epoxy type and ethylene described in JP-A No. 50-96216. Imine type, vinyl sulfone type, sulfonate type, acryloyl type,
Although a carbodiimide-based cross-linking agent can be used, the isocyanate-based compounds, epoxy compounds and acid anhydrides shown below are preferred.

As a cross-linking agent preferably used, JP-A No. 2
The isocyanate-based and thioisocyanate-based crosslinking agents represented by the general formula (7) described in JP-A-002-14437 can be mentioned.

The above-mentioned isocyanate cross-linking agent is an isocyanate having at least two isocyanate groups and its adduct (adduct), and more specifically, aliphatic diisocyanates and fats having a cyclic group. Group diisocyanates, benzene diisocyanates, naphthalene diisocyanates, biphenyl isocyanates, diphenylmethane diisocyanates, triphenylmethane diisocyanates, triisocyanates, tetraisocyanates, adducts of these isocyanates and divalent with these isocyanates or Examples thereof include adducts with trivalent polyalcohols. As a specific example, JP-A-56-5535, No. 1
The isocyanate compounds described on pages 0 to 12 can be used. That is, ethane diisocyanate, butane diisocyanate, hexane diisocyanate, 2,2-dimethylpentane diisocyanate, 2,
2,4-trimethylpentane diisocyanate, decane diisocyanate, ω, ω′-diisocyanate-1,
3-dimethylbenzene, ω, ω′-diisocyanate-1,2-dimethylcyclohexane diisocyanate,
ω, ω-diisocyanate-1,4-diethylbenzene, ω, ω′-diisocyanate-1,5-dimethylnaphthalene, ω, ω′-diisocyanate-n-propylbiphenyl, 1,3-phenylene diisocyanate, 1
-Methylbenzol-2,4-diisocyanate, 1,
3-dimethylbenzol-2,6-diisocyanate,
Naphthalene-1,4-diisocyanate, 1,1'-dinaphthyl-2,2'-diisocyanate, biphenyl-
2,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, 2,2'-dimethyldiphenylmethane-4,4'-diisocyanate, 3,
3'-dimethoxydiphenylmethane-4,4'-diisocyanate, 4,4'-diethoxydiphenylmethane-
4,4'-diisocyanate, 1-methylbenzol-
2,4,6-triisocyanate, 1,3,5-trimethylbenzene-2,4,6-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, triphenylmethane-4,4 ', 4' Triisocyanates, tolylene diisocyanates, 1,5-naphthylene diisocyanates; dimer or trimer adducts of these isocyanates (eg hexamethylene diisocyanate 2 mol adduct, hexamethylene diisocyanate 3 mol adduct, 2,4 -Adduct of 2 mol of tolylene diisocyanate, adduct of 3 mol of 2,4-tolylene diisocyanate, etc.); adduct of two or more different isocyanates selected from these isocyanates; A trihydric polyalcohol (preferably a polyalcohol having up to 20 carbon atoms, such as ethylene glycol, propylene glycol, pinacol, trimethylolpropane, etc.) and an adduct (eg, an adduct of tolylene diisocyanate and trimethylolpropane; hexamethylene diisocyanate). Such as trimethylolpropane adduct) and the like. Among them, the adduct of isocyanate and polyalcohol has a particularly high ability to improve interlayer adhesion and prevent layer peeling, image shift and bubble generation. Such polyisocyanates may be placed on any part of the heat developable recording material. For example, an image forming layer of a support such as an image forming layer, a surface protective layer, an intermediate layer, an antihalation layer, an undercoat layer, etc. in a support (particularly when the support is paper, can be included in the size composition). It can be added to any layer on the side, and can be added to one or more layers among these layers.

In the present invention, a dye layer may be provided between the image forming layer and the support or on the surface opposite to the image forming layer. The dye contained in the dye layer needs to have absorption in the wavelength region of the exposure light source, but its absorption waveform and chemical structure are arbitrary. When a near infrared laser is used as a light source, the transmission absorption spectrum of the dye layer preferably has an absorption maximum between 750 nm and 830 nm.
Further, the smaller the absorption in the visible region and the near-ultraviolet region, the more preferable.

As described above, the structure of the dye that can be used in the present invention is not particularly limited, but examples of dyes that can be preferably used include, for example, JP-A-7-
Dye compound described in 13295, JP-A-8-278
No. 592, No. 9-230531, No. 11-2.
Dye compounds described in JP-A-23898, JP-A-11-
Dyes described in Japanese Patent No. 231464, Japanese Patent Publication No. 9-5095
Dihydroperimidine squaric acid complex dyes described in JP-A No. 03-2003, JP-A Nos. 10-36695 and 10-104.
785 and 10-204310, dihydroperimidine squarylium dyes, JP-A-10-1
Examples thereof include squarylium dyes described in JP-A No. 04779 and 10-207002, and oxonol compounds described in JP-A No. 7-102179. Further, as other dyes preferably usable in the present invention,
D-1 to D- described in JP-A-2002-14437
The compound represented by 9 is mentioned.

The dyes that can be used in the present invention are
It is basically arbitrary and is not limited by the above description. Further, in the present invention, it is possible to use two or more kinds of dyes together. When two or more types of dyes are used, they may be contained in the same dye layer, or separate dye layers may be provided. When the dye layer is provided on the side opposite to the image forming layer with the support sandwiched, these dyes are used in an addition amount such that the absorption concentration of the dye layer at the exposure wavelength is 0.3 or more. It is preferable. The addition amount is more preferably 0.5 or more and less than 2, and particularly preferably the addition amount is 0.7 or more and less than 1.5. Also, when these dyes are used in the dye layer provided between the support and the image forming layer, it is preferable to use the same addition amount as above. Also, these dyes can be added to the image forming layer. When these dyes are added to the image forming layer, it is preferable to use such an amount that the absorption density of the photosensitive layer at the exposure wavelength is less than 0.6. More preferably, the addition amount is such that the absorption concentration is less than 0.5, and particularly preferably the absorption concentration is 0.01 or more and less than 0.4. Regarding the usage of these dyes, the methods described in the patents listed in the examples of dyes that can be preferably used can be appropriately selected and used.

In the present invention, a macrocyclic compound containing a hetero atom can be used, if necessary, which is effective when a spectral sensitizing dye is used, has high sensitivity, and improves desensitization during storage. Can bring

The macrocyclic compound containing a hetero atom that can be used in the present invention is a 9-membered or larger macrocyclic compound containing at least one of a nitrogen atom, an oxygen atom, a sulfur atom and a selenium atom as a hetero atom. . Furthermore, 12
~ 24-membered ring is preferred, and more preferred is 15-21.
It is a member ring.

A typical compound is a compound known as crown ether, which was synthesized by Pederson in 1967 and has been synthesized in large numbers since its unique report. These compounds are available from CJPederson, Journal
of American chemical society vol, 86 (2495), 7017〜7
036 (1967), GWGokel, SH, Korzeniowski, "Macrocyclic
polyethrsynthesis ", Springer-Vergal, (1982), Oda,
Edited by Shono and Tabushi, "The Chemistry of Crown Ether", Chemistry Doujin (1
978), "Host-Guest" edited by Tabushi, Kyoritsu Publishing (197)
9), Sasaki, Koga "Synthetic Organic Chemistry" Vol. 45
(6), 571-582 (1987) and the like.

In the heat-developable recording material according to the present invention,
If necessary, a matting agent can be contained on the side of the image forming layer or on the side opposite to the side of the support. 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, glass powder described in French Patent No. 1,296,995, British Patent No. 1,173,181, etc. Alkaline earth metals or carbonates such as cadmium, zinc, etc.
Etc. can be used as a matting agent. Examples of the organic substance include starch described in US Pat. No. 2,322,037 and the like, starch derivatives described in Belgian Patent 625,451 and British Patent 981,198, and the like. Polyvinyl alcohol described in JP-A-44-3643, polystyrene or polymethacrylate described in Swiss Patent No. 330,158, polyacrylonitrile described in US Pat. No. 3,079,257, US patent Organic matting agents such as polycarbonate described in the specification of No. 3,022,169 can be used.

The matting agent used in the present invention can be contained in any constituent layer, but in the present invention, it is preferably a constituent layer other than the image forming layer, and more preferably the most viewed from the support. It is the outer layer. The method for adding the matting agent used in the present invention may be a method in which the matting agent is preliminarily dispersed in a coating solution and then applied, or after applying the coating solution,
A method of spraying the matting agent before the completion of drying may be used. When adding multiple types of matting agents,
You may use both methods together.

In the present invention, a conductive compound such as a metal oxide or a conductive polymer may be included in the constituent layer for the purpose of improving the charging property. These may be contained in any of the constituent layers, but preferably an undercoat layer,
It is preferably contained in a backing layer, a layer between the image forming layer and the undercoat layer, and the like. In the present invention, US Pat.
The electroconductive compounds described in Nos. 244,773 columns 14 to 20 are preferably used.

All coating solutions used for coating the heat-developable recording material of the present invention are preferably filtered before coating. In the filtration, it is preferable to pass a filter medium having an absolute filtration accuracy or a quasi-absolute filtration accuracy of 5 to 50 μm at least once.

The support used in the present invention is a plastic film (eg, polyethylene terephthalate, polycarbonate, or the like) in order to prevent deformation of the image after development processing.
Polyimide, nylon, cellulose triacetate, polyethylene naphthalate) are preferable.

Among them, preferable supports include polyethylene terephthalate (hereinafter abbreviated as PET) and a plastic (hereinafter abbreviated as SPS) containing a styrene polymer having a syndiotactic structure.
The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm. It is also possible to use a heat-treated plastic support. The plastics to be adopted include the above-mentioned plastics. The heat treatment of the support means that after the support is formed into a film and before the image-forming layer is coated, the temperature is 30 ° C. or higher, preferably 35 ° C. or higher, higher than the glass transition point of the support. It is more preferable to heat at a temperature higher than 40 ° C.

Next, the plastic used for the support will be described. In PET, the polyester component is composed entirely of polyethylene terephthalate. In addition to polyethylene terephthalate, terephthalic acid, naphthalene-2,6-dicarboxylic acid, isophthalic acid, butylene dicarboxylic acid, 5-sodium sulfoisophthalic acid, and A polyester containing a modified polyester component of adipic acid or the like and ethylene glycol, propylene glycol, butanediol, cyclohexanedimethanol, or the like as a glycol component in an amount of 10 mol% or less of the total polyester may be used.

Unlike ordinary polystyrene (atactic polystyrene), SPS is polystyrene having stereoregularity. The regular stereoregular structure part of SPS is called racemo chain, and it is preferable that there are more regular parts such as 2 chains, 3 chains, 5 chains or more. In the present invention, the racemo chain is 2 It is preferable that the chain is 85% or more, the 3 chain is 75% or more, the 5 chain is 50% or more, and the chain is 30% or more. Polymerization of SPS can be carried out according to the method described in JP-A-3-131843.

Known methods can be used for the method for forming the support film and the method for producing the subbing film according to the present invention.
Preferably, paragraph [00 of JP-A-9-50094 is used.
30] to [0070].

The heat-developable recording material of the present invention has at least one image forming layer on the support. Although only the image forming layer may be formed on the support, it is preferable to form at least one non-photosensitive layer on the image forming layer.
Further, in order to control the amount or wavelength distribution of light passing through the image forming layer, a filter dye layer may be formed on the same side as the image forming layer and / or an antihalation dye layer, a so-called backing layer may be formed on the opposite side. Further, the image forming layer according to the present invention may be composed of a plurality of layers, and the sensitivity may be a high sensitive layer / low sensitive layer or a low sensitive layer / high sensitive layer for adjusting gradation.

Examples of the application of the heat-developable recording material of the present invention include a sequential multilayer coating method in which coating and drying of each layer are repeated.
Roll coating methods such as reverse roll coating and gravure roll coating, blade coating, wire bar coating, die coating and the like are used. In addition, before drying the already coated layer using multiple coaters,
Simultaneous multi-layer coating method in which the following layers are applied and multiple layers are dried at the same time, or multiple coating solutions are laminated and applied using slide coating, curtain coating or an extrusion type die coater with multiple slits Used. Of these, the latter is more preferable because it can prevent the occurrence of coating failure due to foreign substances brought in from the outside. Furthermore, when the simultaneous multi-layer coating method is used, in order to prevent mixing between layers, the viscosity of the coating liquid of the uppermost layer is set to 0.1 Pa · s or more and the coating liquid of other layers is coated. The viscosity is preferably 0.03 Pa · s or more. In addition, when the solid content dissolved in the coating liquid of each layer is hardly soluble or insoluble in the organic solvent contained in the adjacent layer when laminated in a liquid state with the adjacent layer, precipitation occurs at the boundary surface. As a result, since the coating film is disturbed or turbid, the organic solvent most contained in the coating liquid of each layer is the same type (the content of the organic solvent commonly contained in each coating liquid in each liquid is It is more than the organic solvent).

After the multi-layer coating, it is preferable to dry as quickly as possible, and it is desirable to reach the drying step within 10 seconds in order to avoid inter-layer mixing due to flow, diffusion, density difference and the like. As a drying method, a hot air drying method, an infrared drying method, or the like is used, and the hot air drying method is particularly preferable.
The drying temperature at that time is preferably 30 to 100 ° C.

The heat-developable recording material of the present invention may be cut into a desired size immediately after coating and drying and then packaged, or may be temporarily stored before being wound into a roll, cut and packaged. The winding method is not particularly limited, but winding by tension control is generally used.

Next, the constitution and manufacturing method of the photothermographic material of the present invention will be explained. The photothermographic material of the invention can be prepared by coating a support with a silver halide, an organic acid silver salt, a reducing agent and a contrast adjusting agent. The photothermographic material preferably has a constitution in which at least one image forming layer containing silver halide, an organic acid silver salt, a reducing agent and a contrast enhancer, and a binder is provided on a support. . Further, the heat-developable photosensitive material can be provided with a non-sensitive layer such as a protective layer, an undercoat layer, a filter layer, etc. in addition to the image forming layer, and the filter layer may be provided on the image forming layer side on the support. It may be provided on the side opposite to the image forming layer. At least one of the layers formed on the image forming layer side of the photothermographic material of the present invention is preferably a coating layer formed by coating a coating liquid containing 30% by mass or more of an organic solvent, and more preferably, The image forming layer is a coating layer formed by applying a coating liquid containing 30% by mass or more of an organic solvent as a solvent. The organic solvent is 30% by mass in the coating liquid.
˜90% by mass, preferably 50% by mass to 9%
It is more preferable that the content is 0% by mass. The organic solvent is not particularly limited and may be single or plural, and ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, alcohols such as methanol, ethanol, propanol, butanol and phenol, ethylene glycol, triethylene glycol and the like. Polyhydric alcohols, ethyl acetate, esters such as butyl propionate, benzene, toluene, aromatic hydrocarbons such as xylene, pentane, hexane, heptane, octane, nonane, cyclohexane and other aliphatic hydrocarbons, ethyl ether, Ethers such as tetrahydrofuran,
Preferred examples include halogenated hydrocarbons such as carbon tetrachloride, dichloromethane and dichloroethane, amines such as triethylamine and diethanolamine, and amides such as dimethylformamide and dimethylacetamide.

The organic solvent used in the present invention is preferably one which dissolves 3 g or more in 100 g of water, and 10 g in 100 g of water.
More preferred are those that dissolve. Specifically, methanol, methyl ethyl ketone and dimethyl acetamide are preferably used.

Although the coating solution may contain water,
When it contains water, it is preferably 20% by mass or less, and more preferably 10% by mass or less.

In the photothermographic material of the present invention, the total amount of the residual organic solvent in each constituent layer after coating and heat treatment is 0.1 to 50 mg per 1 m ^{2 of the} photothermographic material, more preferably 0. 1-25 mg, and even more preferably 0.1-
5 mg, particularly preferably 0.1 to 3 mg. Regarding the above-mentioned preferably used organic solvents, there is an appropriate point in the amount of residual solvent. With respect to methanol, methyl ethyl ketone, and dimethyl acetamide, the residual solvent is preferably 0.1 to 1 per 1 m ^{2 of the} photothermographic material.
It is 0 mg, more preferably 0.1 to 5 mg, still more preferably 0.1 to 2 mg.

The method of measuring the amount of the solvent contained in the photothermographic material is as follows.
Accurately measure this area. This is finely chopped, stored in a dedicated vial bottle, and sealed. This is a headspace sampler (HP7694 manufactured by Hewlett Packard).
It can be measured by setting the temperature to a predetermined temperature, introducing it into a gas chromatography after heating to a set temperature, and measuring the area of the target solvent peak. Since the organic solvent contained in the photothermographic material cannot be completely exhausted in one injection, the injection of the same sample is repeated several times, and the measurement is performed by the integration.

Next, the image forming method of the present invention will be described in detail. In the image forming method of the present invention, the photothermographic material is first exposed to light having a wavelength of 750 to 800 nm. The exposure apparatus used for exposure has an exposure time of 10
Laser diode (LD) capable of exposure of -7 seconds or less
An exposure apparatus that uses as a light source is used. Any of these light sources may be used as long as it can generate light having an electromagnetic wave spectrum in a target wavelength range. For example, a dye laser, a gas laser, a solid-state laser, a semiconductor laser and the like can be used, but the semiconductor laser is particularly preferably used from the viewpoint of space saving and cost saving.

In the image forming method of the present invention, it is preferable to expose the photothermographic material by overlapping the light beams of the light source. The overlap means that the sub-scanning pitch width is smaller than the beam diameter. The overlap refers to, for example, the beam diameter and the full width at half maximum of the beam intensity (FWHM).
When expressed by, it can be quantitatively expressed by FWHM / sub-scanning pitch width (overlap coefficient). In the present invention, this overlap coefficient is preferably 0.2 or more.

The scanning method of the light source of the exposure apparatus used in the present invention is not particularly limited, and a cylinder outer surface scanning method, a cylinder inner surface scanning method, a flat surface scanning method and the like can be used. Also,
The channel of the light source may be a single channel or a multi-channel, but a multi-channel equipped with two or more laser heads is preferable in that high output can be obtained and the writing time can be shortened. Particularly, in the case of the cylindrical outer surface type, a multi-channel in which several to several tens or more laser heads are mounted is preferably used.

When the photothermographic material to be exposed has a low haze at the time of exposure, interference fringes tend to occur, so it is preferable to prevent this. Techniques for preventing the generation of interference fringes include a technique disclosed in Japanese Patent Application Laid-Open No. 5-113548, in which laser light is obliquely incident on a photosensitive material, and International Publication WO95 / 317.
Methods utilizing a multi-mode laser disclosed in Japanese Patent Publication No. 54, etc. are known, and it is preferable to use these techniques.

The scanning system of the light source of the exposure apparatus preferably used in the present invention is the inner drum system (cylindrical inner surface scanning system). The exposure is performed by scanning the laser light generated from the laser diode through the polygon mirror (prism) onto the surface of the photothermographic material conveyed to the inner drum portion. The exposure time in the main scanning direction is determined by the rotation speed of the polygon mirror and the inner diameter of the drum. The main scanning speed on the surface of the photothermographic material of the present invention is preferably 500 m / sec to 1500 m / sec. A more preferable main scanning speed is 1100 m / sec to 1500 m / sec.

When the photothermographic material to be exposed has a low haze at the time of exposure, interference fringes tend to occur, so it is preferable to prevent this. Techniques for preventing the generation of interference fringes include a technique disclosed in Japanese Patent Application Laid-Open No. 5-113548, in which laser light is obliquely incident on a photosensitive material, and International Publication WO95 / 317.
Methods utilizing a multi-mode laser disclosed in Japanese Patent Publication No. 54, etc. are known, and it is preferable to use these techniques.

In the image forming method of the present invention, the photothermographic material is exposed to light to form a latent image, and then the preheating section,
Development is performed by a heat developing machine having a heat developing section and a slow cooling section. The development temperature by the heat developing machine is preferably 80 to 250 ° C, and more preferably 100 to 140 ° C.
The total development time by the heat developing machine is preferably 1 to 180 seconds, more preferably 5 to 90 seconds. Further, the processing speed of the heat developing section by the heat developing machine is preferably 21 to 100 mm / sec, and 27 to
More preferably, it is 50 mm / sec.

The exposed photothermographic material is first heated in the preheating section. The preheating section is provided for the purpose of preventing uneven processing due to dimensional change of the photothermographic material during heat development. The heating in the preheating section is lower than the heat development temperature (for example, about 10 to 30 ° C. lower), and it is desirable to set the temperature and time sufficient to evaporate the solvent remaining in the photothermographic material. At a temperature higher than the glass transition temperature (Tg) of the support of the photosensitive material,
It is preferable to set so that development unevenness does not occur. Generally, it is preferable to heat at 80 ° C. or higher and lower than 115 ° C. for 5 seconds or longer.

The photothermographic material which has been heated in the preheating section is subsequently heated in the heat developing section. In the image forming method of the present invention, the heat developing section is provided with a heating member on the image forming layer side and the back layer side with respect to the conveyed photothermographic material, and is also provided with a conveying roller only on the image forming layer side. . For example, when the photothermographic material is conveyed with the image forming layer on the upper side, there is no conveyance roller on the lower side (back layer side of the photothermographic material) with respect to the conveying direction of the photothermographic material, and the upper side (heat development The transport roller is provided only on the image forming layer side of the photosensitive material. In the present invention, the heat developing section is configured as described above to prevent density unevenness and physical deformation.

In the heat developing section, the photothermographic material is heated by a heating member such as a heater. The heating temperature in the heat development section is a temperature sufficient for heat development, and is generally 110 ° C to 140 ° C. Since the photothermographic material is exposed to a high temperature of 110 ° C. or higher in the heat development section,
Part of the components contained in the material or part of the decomposed components by heat development may volatilize. These volatile components cause uneven development, corrode the components of the thermal processor, deposit in low temperature places, causing the screen to deform as foreign matter, and stains on the screen. , Etc. are known to have various adverse effects. As a method for eliminating these influences, a method is known in which a filter is installed in the heat developing machine and the air flow in the heat developing machine is optimally adjusted. These methods can be effectively used in combination. For example, in International Publication Nos. WO95 / 30933, 97/21150, and Japanese Patent Publication No. 10-500946, there is a first opening having bound absorbent particles for introducing volatile matter and a second opening for discharging volatile matter. It is described that a filter cartridge having an opening is used for a heating device that contacts a film to heat it. In addition, International Publication WO96 / 12213 and Japanese Patent Publication No. 10-507403 describe the use of a filter in which a heat conductive condensing collector and a gas absorbing fine particle filter are combined. In the present invention, these can be preferably used. Also, in U.S. Pat. No. 4,518,845 and Japanese Patent Laid-Open No. 3-54331, a device for removing vapor from a film, a pressure device for pressing the film against the heat transfer member, and a heat transfer member are heated. And a device for doing so. In addition, International Publication WO98 / 27458 discloses that a component that increases volatilization fog from a film is removed from the film surface. These can also be preferably used in the present invention.

The temperature distribution of heating in the preheating section and the heat developing section is preferably ± 1 ° C. or less,
It is more preferably 0.5 ° C. or lower.

The heat-developable photosensitive material heated in the heat-development section is
Next, it is cooled in the slow cooling part. Cooling is preferably performed gradually so that the photothermographic material is not physically deformed,
The cooling rate is preferably 0.5 to 10 ° C / sec.

FIG. 1 shows an example of the structure of a thermal developing machine used in the image forming method of the present invention. FIG. 1 is a schematic side view of the heat developing machine. The heat developing machine shown in FIG. 1 comprises a preheating section A for preheating the photothermographic material 10, a heat developing section B for heat developing processing, and a slow cooling section C for cooling the photothermographic material. To be done. The preheating unit A includes a pair of carry-in rollers 11 (the upper roller is a silicon rubber roller,
The lower roller has a heat roller made of aluminum). The heat developing section B is provided with a plurality of rollers 13 on the side in contact with the surface 10a on the side where the image forming layer of the heat developing photosensitive material 10 is formed, and on the opposite side to the back layer side of the heat developing photosensitive material 10. A smooth surface 1 to which a non-woven fabric (made of, for example, aromatic polyamide or Teflon) is attached on the side that contacts the surface 10b.
4 is provided. The clearance between the roller 13 and the smooth surface 14 is appropriately adjusted so that the photothermographic material 10 can be conveyed. Generally, clearance is 0 to 1 mm
It is a degree. Further, the heat developing section B is provided with a heater 15 (a plate heater or the like) for heating the photothermographic material 10 from the image forming layer side and the back layer side, above the roller 13 and below the smooth surface 14. . The slow cooling section C includes a carry-out roller pair 12 for carrying out the photothermographic material 10 from the heat developing section B and a guide plate 16.

The photothermographic material 10 is thermally developed while being conveyed from the carry-in roller pair 11 to the carry-out roller pair 12.
The photothermographic material 10 is exposed and then carried into the preheating section B. In the preheating section B, the photothermographic material 10
Is corrected into a flat shape by a plurality of carrying-in roller pairs 12, preheated, and carried into the thermal developing section B. The photothermographic material 10 carried into the photothermographic section B is inserted into the clearance between the plurality of rollers 13 and the smooth surface 14, and is driven by the roller 13 that comes into contact with the surface 10a of the photothermographic material 10 to form the back layer side. The surface 10b is transported while sliding on the smooth surface 14. While being conveyed, the photothermographic material 10 is heated from both the image forming layer side and the back layer side to a temperature sufficient for heat development by the heater 15 to develop the latent image formed by exposure. . After that, the photothermographic material 10 is conveyed to the slow cooling section C, is straightened by the pair of carry-out rollers 12, and is then processed by the heat developing machine 2.
Delivered from 0.

The material of the surface of the roller 13 of the heat developing section B and the member of the smooth surface 14 have high temperature durability and are not particularly limited as long as they do not hinder the conveyance of the photothermographic material 10, but the surface of the roller 13 is not limited. It is preferable that the material is a silicon rubber, and the member of the smooth surface 14 is a nonwoven fabric made of aromatic polyamide or Teflon (registered trademark) (PTFE). The heater 15 is not particularly limited in shape and number as long as it can heat the photothermographic material 10 to a temperature sufficient for thermal development, but the heating temperature of each can be freely set. Preferably.

The photothermographic material 10 is heated by the preheating section A having the carry-in roller pair 11 and the heat development section B having the heater 15. The preheating section A is heated at the heat development temperature. It is desirable to set the temperature and time to be lower (for example, about 10 to 30 ° C. lower) and sufficient to evaporate the amount of water in the photothermographic material 10. The glass transition of the support of the photothermographic material 10 is preferable. It is preferable to set the temperature higher than the temperature (Tg) so as to prevent uneven development. The temperature distribution between the preheating section and the heat development processing section is preferably ± 1 ° C or less, more preferably ± 0.5 ° C or less.

In the slow cooling section C, in order to prevent the photothermographic material 10 from being rapidly cooled and deformed, the guide plate 16 is preferably made of a material having a low thermal conductivity.

In the image forming method of the present invention, exposure and heat development are carried out by an online system of an exposure device (plotter), an auto carrier and a heat developing machine (processor). The auto carrier is for automatically carrying the exposed photothermographic material to the heat developing machine, and the carrying mechanism may be any system such as a belt conveyer or roller conveyer, but roller conveyer is preferable. Further, it is preferable to provide a mechanism for the auto carrier so that heat does not enter from the heat developing machine side to the exposing device side. For example, there is a system in which air is blown into the exposing device and the heat developing device from the lower center of the auto carrier.

In the image forming method of the present invention, the processing speed (R ₁ ) of the photothermographic material in the auto carrier and the processing speed (R ₁ ) of the photothermographic material in the preheating section of the heat developing machine are set.
₂ ), the processing speed (R ₃ ) of the photothermographic material in the heat development section of the heat processor preferably satisfies the following relational expression: R ₃ > R ₂ ≧ R ₁ . Further, in the image forming method of the present invention, it is preferable to perform the developing treatment under the condition that the linear velocity ratio between the preheating portion of the heat developing machine and the heat developing treatment portion becomes 95.0% to 99.9%. The developing treatment is preferably performed under the condition that the linear velocity ratio between the preheating section and the preheating section is 90.0% to 100%. If the linear velocity ratio between the preheating portion and the heat development processing portion is less than 95.0% and / or if the linear velocity ratio between the auto carrier and the preheating portion is less than 90.0%, scratches or jamming may occur. This is not preferable because the occurrence of the occurrence of such a phenomenon deteriorates the transportability and causes uneven density.

The photothermographic material has, for example, a width of 550.
A sheet-like material having a length of up to 650 mm and a length of 1 to 65 m is used, and a part or all of the sheet-like material is wound into a cylindrical core member with the image forming layer as the outer side, and incorporated in a thermal development system.

[0144]

EXAMPLES The features of the present invention will be described more specifically below with reference to examples and comparative examples. Materials shown in the following examples,
The usage amount, ratio, processing content, processing procedure, etc. can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be limitedly interpreted by the following specific examples.

<Example 1> (Preparation of thermal development recording material) Samples 1 to 14 as thermal development recording materials were prepared according to the method described below.

(Preparation of subbed PET support) Commercially available 2
Both sides of a 125 μm-thick PET film which has been axially stretched and heat-fixed are subjected to a corona discharge treatment of 8 w / m ² · min, and one side is coated with the following subbing coating solution a-1 to a dry film thickness of 0.8 μm. Is coated and dried to form a subbing layer A-1, and the opposite surface is coated with a subbing coating liquid b-1 for antistatic processing described below to a dry film thickness of 0.8 μm and dried. To obtain an antistatic processed subbing layer B-1.

[0147] [Undercoating liquid a-1]   Butyl acrylate (30% by mass), tert-butyl acrylate     (20 mass%), styrene (25 mass%),     2-hydroxyethyl acrylate (25% by mass)     270 g of copolymer latex liquid (solid content 30%)   Hexamethylene-1,6-bis (ethylene urea) 0.8 g   Polystyrene fine particles (average particle size 3 μm) 0.05 g   Colloidal silica (average particle size 90 μm) 0.1 g   Amount of water that becomes 1 liter

[Undercoating Liquid b-1] SnO ₂ / Sb (mass ratio 9/1, average particle size 0.18 μm) 200 mg / m ² butyl acrylate (30% by mass), styrene (20% by mass) ), Glycidyl acrylate (40% by mass), copolymer latex liquid (solid content 30%) 270 g hexamethylene-1,6-bis (ethyleneurea) 0.8 g water 1 liter

(Heat Treatment of Support) In the undercoat drying process of the above-mentioned undercoated support, the support was heated at 140 ° C. and then gradually cooled.

(Preparation of Photosensitive Emulsion) [Preparation of Silver Halide Emulsion A] After dissolving 7.5 g of inert gelatin and 10 mg of potassium bromide in 900 ml of water and adjusting the temperature to 35 ° C. and pH to 3.0. , Silver nitrate 7
370 ml of an aqueous solution containing 4 g, and sodium chloride, potassium bromide, potassium iodide and [Ir (NO) Cl ₅ ] salt in a molar ratio of (60/38/2) were added to 1 × per 1 mol of silver.
10 ^-6 mol, 1 × rhodium chloride salt per 1 mol of silver
370 ml of an aqueous solution containing 10 ⁻⁶ mol and pAg7.
While maintaining at 7, it was added by the controlled double jet method. Then 4-hydroxy-6-methyl-1,3,3
a, 7-Tetrazaindene was added, and reduction sensitization was performed by adjusting pH to 8.0 and pAg 6.5 with NaOH to obtain an average particle size of 0.06 μm, monodispersity of 10%, and projected diameter area. A cubic silver halide emulsion having a coefficient of variation of 8% and a [100] plane ratio of 87% was obtained. A silver halide emulsion A was obtained by subjecting this halogenated emulsion to coagulation sedimentation using a gelatin coagulant and desalting.

[Preparation of Sodium Behenate Solution] 945
32.4 g of behenic acid and 9.9 arachidic acid in ml of pure water.
g and stearic acid 5.6 g were dissolved at 90 ° C. Next, 98 ml of a 1.5 mol / L sodium hydroxide aqueous solution was added while stirring at high speed. Next, concentrated nitric acid 0.93
After adding ml, the mixture was cooled to 55 ° C. and stirred for 30 minutes to obtain a sodium behenate solution.

[Preparation of Preform Emulsion of Silver Behenate and Silver Halide Emulsion A] To the above sodium behenate solution was added 1.51 g of the above silver halide emulsion A, and the pH was adjusted to 8.1 with a sodium hydroxide solution. After that, 147 ml of 1 mol / L silver nitrate solution was added over 7 minutes, and further 20
Water-soluble salts were removed by minute stirring and ultrafiltration. The silver behenate produced as described above had an average particle size of 0.
The particles were 8 μm and had a monodispersity of 8%. After forming the flocs of the above dispersion, water was removed, and water was further washed 6 times, water was removed, and then dried to prepare preform emulsions of silver behenate and silver halide emulsion A.

[Preparation of Photosensitive Emulsion] Polyvinyl butyral (average molecular weight 300
544 g of a solution of 0) in methyl ethyl ketone (17% by mass)
And 107 g of toluene were gradually added and mixed, and then,
Dispersion was carried out at 27.5 MPa and 30 ° C. for 10 minutes with a media disperser using a 5 mm size ZrO ₂ bead mill to prepare a photosensitive emulsion.

(Preparation of Heat-Development Recording Material) The following layers were simultaneously coated on the undercoated support to prepare Samples 1 to 14 as heat-development recording materials.

[Back surface side coating] On the undercoat layer B-1 of the above-prepared support, a dye-containing layer coating solution having the following composition was coated so as to have a dry mass of 4.2 g / m ² .
It was dried at 55 ° C. for 30 minutes.

<Dye-Containing Layer Coating Solution> Methyl ethyl ketone 40 g Cellulose acetate butyrate (Eastman Chemical Co., CAB381-20) 1.7 g Cellulose acetate propylate (Eastman Chemical Co., CAB553-0.4) 1.7 g Polyhydroxy Styrene (Maruzen Petrochemical Co., Ltd., Maruka Linker PHMC) 0.3 g Dye D 32 mg Polyester resin (Bostic Co., VitelPE2200B) 200 mg Matting agent: Monodispersity 15% Average particle size 8 μm Monodisperse silica 90 mg C ₈ F ₁₇ (CH ₂ CH) ₂ O) ₁₂ C ₈ F ₁₇ 200 mg C ₉ F ₁₉ -C ₆ H ₄ -SO ₃ Na 75 mg

[Coating on Image Forming Layer Side] On the undercoat layer A-1 of the above-prepared support, an image forming layer coating solution and a surface protective layer coating solution having the following compositions are used, and the surface protective layer serves as the uppermost layer. 1 which is a heat development recording material
~ 14 were produced. The coating liquid for the image forming layer was coated so that the coating silver amount was 2.4 g / m ^2, and the coating liquid was dried in Table 1.
It carried out on the conditions shown in.

[0158] <Coating liquid for image forming layer>   Photosensitive emulsion 240g   Sensitizing dye 1 1.7 mg   Halogen compound 1 180mg   Calcium bromide 1.7mg   2,4-chlorobenzoylbenzoic acid 1.1 g   2-Mercaptobenzimidazole 110 mg   Tribromomethylsulfoquinoline 850mg   Dye E 5mg   Phthalazine 0.6g   Hardening agent (shown in Table 1) 0.1 g   Antifoggant S 0.01 g   4-methylphthalic acid 0.25g   Tetrachlorophthalic acid 0.2g   Benzoic acid derivative 1 0.2 g   Reducing agent A 5.9g   Isocyanate compound (Desmodur N3300 manufactured by Mobay)                                                               0.5 g   40 ml of methanol   Methyl ethyl ketone 30 ml   Dimethylacetamide 10 ml

<Surface protection layer coating liquid> Acetone 5 ml Methyl ethyl ketone 21 ml Cellulose acetate butyrate (Eastman Chemical Co., CAB-381-20) 2.3 g Methanol 7 ml Phthalazine 250 mg Vinyl sulfone compound HD-1 38 ml Matting agent: Monodispersity 10% Average particle size 4 μm Monodisperse silica 70 mg C ₁₂ F ₂₅ (CH ₂ CH ₂ O) ₁₀ C ₁₂ F ₂₅ 20 mg C ₈ F ₁₇ -C ₆ H ₄ -SO ₃ Na 10 mg

[0160]

[Chemical 30]

[0161]

[Chemical 31]

[0162]

[Chemical 32]

The comparative compounds of the contrast enhancer shown in Table 1 are as follows.

[0164]

[Chemical 33]

Evaluation of heat-developable recording material (exposure treatment) The prepared heat-developable light-sensitive material has a width of 590 mm.
And a sheet having a length of 59 m, which was wound around a cylindrical core member with the image forming layer side facing outward to obtain a roll-shaped sample. This roll sample is 785n
NEC FT-286R with m semiconductor laser
Set to. The exposure apparatus and the heat developing machine shown in FIG. 1 were docked, and exposed and heat-developed.

(Heat Development Processing) The photothermographic material was transferred online from the above-mentioned exposure apparatus through an auto carrier to obtain the image shown in FIG.
Thermal development processing was performed with the thermal developing machine shown in FIG. The roller surface material of the heat development treatment section was made of silicone rubber and the smooth surface was made of Teflon nonwoven fabric, and the line speed of conveyance in the heat development treatment section was set to 25 mm / sec. Preheating section 12.2 seconds (The driving system of the preheating section and the thermal development processing section are independent,
The speed difference with the heat development part is set to -0.5% to -1%, and the speed difference with the preheating part of the auto carrier is 0% to -1.0%.
Set the temperature of the metal roller of each preheating section, the time is 1st roller temperature 67 ℃, 2.0 seconds, 2nd roller temperature 8
2 ° C, 2.0 seconds, third roller temperature 98 ° C, 2.0 seconds,
Fourth roller temperature temperature 107 ° C, 2.0 seconds, fifth roller temperature 115 ° C, 2.0 seconds, sixth roller temperature 120
C., 2.0 seconds), a heat development treatment section at 120.degree. C. (surface temperature of photothermographic material) for 17.2 seconds, and a slow cooling section for 13.6 seconds. The temperature accuracy in the width direction is ± 0.
It was 5 ° C. The temperature of each roller was set to be 5 cm longer on both sides than the width of the photothermographic material (for example, 61 cm in width), and the temperature was also applied to that portion to obtain temperature accuracy. Since the temperature drops sharply at both end portions of each roller, the temperature of the portion which is 5 cm longer than the width of the photothermographic material is set to be 1 to 3 ° C. higher than that of the central portion of the roller. (For example, within a width of 61 cm)
Care was taken so that the image density of 1 was a uniform finish.

(Evaluation of Photographic Performance) 1) Gamma A characteristic curve of density D-exposure amount LogE was prepared by adjusting the laser intensity using the above-mentioned exposure / heat development treatment. The slope (Tanθ) of the straight line connecting the points of the densities of 0.3 and 3.0 on this characteristic curve was displayed as the gradation gamma. Gamma is preferably 15 or more.

2) Thermofog Each of the above-prepared heat-developable recording materials was cut into a size of 5 cm × 15 cm, and then conditioned for 12 hours in an atmosphere of 25 ° C. and a relative humidity of 60%. In this way, 10 sheets were laminated, placed in a light-tight barrier bag impermeable to oxygen and water, sealed, and thermotreated at 50 ° C. for 3 days. The minimum density (Dmin) of the unexposed portion after the above-mentioned heat development treatment was performed on the fresh sample which was not subjected to the thermo treatment and the sample which was subjected to the thermo treatment.
Was measured. The increase in fog due to the thermo treatment was calculated by the following formula. ΔDmin is preferably 0.02 or less. If it is more than 0.05, it is not practical. Thermofog (ΔDmin) = (Dmin of thermo-treated sample)-(Dmin of fresh sample)

3) Halftone dot quality Using the above exposure apparatus, 50% halftone dots of 175 lines / inch were drawn, and the halftone dot quality was visually evaluated. The one with good sharpness and smoothness of the halftone dots is ranked as 5,
It is displayed such that the rank value decreases as it deteriorates.

Table 1 shows the results of the above evaluations performed on each sample of the photothermographic material produced.

[0171]

[Table 1]

As is clear from the results shown in Table 1, the heat-developable photosensitive material having the constitution of the present invention can provide a super-high contrast image, good halftone dot quality, and extremely small thermo-fog.

<Example 2> The sample used in Example 1 was used as an A2 size plotter FT-286R manufactured by NEC.
Dry film processor F manufactured by FUJIFILM Corporation
Using DS-6100X and Dry System Auto Carrier FDS-C1000, exposure and heat development processing were performed and the same evaluation was performed. As a result, the same results as in Example 1 were obtained, and the effect of the present invention was clear.

[0174]

According to the present invention, there is provided a heat-developable recording material for plate-making printing, which has a hard gradation, has a small increase in fog during long-term storage, and has good halftone dot quality. You can

[Brief description of drawings]

FIG. 1 is a side view showing an example of the configuration of a heat developing machine used for heat developing treatment of a photothermographic material of the present invention.

[Explanation of symbols]

10 Photothermographic material 11 Carry-in roller pair 12 Delivery roller pair 13 roller 14 smooth surface 15 heating heater 16 Guide plate A Preheating section B heat development processing section C slow cooling section

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03D 13/00 G03D 13/00 A H J F term (reference) 2C068 AA06 2H112 AA03 BC02 BC32 BC41 2H123 AB00 AB03 AB23 AB28 BB00 BB02 BB31 BC10 CA00 CA16 CA22 CB00 CB03 CB20

Claims (22)

[Claims] 1. A photothermographic material containing at least an organic silver salt, a photosensitive silver halide, a reducing agent and a binder on a support and having at least one image forming layer, wherein a residual organic solvent at the time of heat development is used. Amount is 0.1-50mg / m
² , and a photothermographic material containing at least one compound selected from compounds represented by the following formulas (1) to (6). [Chemical 1] [Wherein, R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or a monovalent substituent, X ¹¹ represents an electron-donating heterocyclic group, a cycloalkyloxy group, a cycloalkylthio group,
Represents a cycloalkylamino group or a cycloalkenyl group. ] [Chemical 2] [In the formula, R ²¹ represents an alkyl group, R ²² and R ²³ each independently represent a hydrogen atom or a monovalent substituent, X ²¹ represents an electron-withdrawing group, and L ²¹ represents an aromatic carbocyclic group. Represents n2
Represents 0 or 1. ] [Chemical 3] [In the formula, X ³¹ represents an electron-withdrawing heterocyclic group, a halogen atom or a haloalkyl group, either R ³¹ or R ³² represents a hydrogen atom, and the other represents a hydroxyl group. ] [Chemical 4] [In the formula, R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , A ⁴¹ and A ⁴² each independently represent a hydrogen atom or a monovalent substituent, and G ⁴¹ represents a divalent linking group. n4 represents 0 or 1. ] [Chemical 5] [In the formula, R ⁵¹ , R ^52, and R ⁵³ each independently represent a monovalent substituent. ] [Chemical 6] [In the formula, Q ⁶¹ represents an atomic group forming an aromatic carbocycle or an aromatic heterocycle, and n 6 represents an integer of 1 to 6. ] 2. At least one of the layers formed on the image forming layer side of the support is a layer formed by applying a coating liquid containing 30% by mass or more of an organic solvent. 1. The photothermographic material according to 1. 3. The amount of residual organic solvent during heat development is 0.1 mg.
/ M ² claims, characterized in that it is 25 mg / m ² 1
Alternatively, the photothermographic material according to item 2. 4. The amount of residual organic solvent during heat development is 0.1 mg.
/ M ² claims, characterized in that a to 10 mg / m ² 1
Alternatively, the photothermographic material according to item 2. 5. The amount of residual organic solvent during heat development is 0.1 mg.
The photothermographic material according to claim 1 or 2, characterized in that a / m ² ~5mg / m ^2. 6. A residual organic solvent at the time of heat development containing methanol, and the residual amount of methanol is 0.1 mg / m ^2.
10. The photothermographic material according to claim 1, wherein the photothermographic material is 10 mg / m < ² >. 7. A residual organic solvent at the time of heat development containing methanol, and the residual amount of methanol is 0.1 mg / m ^2.
3. The photothermographic material according to claim 1 or 2, wherein the photothermographic material is from 5 to 5 mg / m ² . 8. A methanol is contained as a residual organic solvent at the time of heat development, and the residual methanol amount is 0.1 mg / m ^2.
3. The photothermographic material according to claim 1 or 2, wherein the photothermographic material is from ² to ² mg / m ² . 9. contains methyl ethyl ketone as the residual organic solvent during thermal development, the heat according to claim 1 or 2 residual methyl ethyl ketone content is characterized in that it is a 0.1mg / m ² ~10mg / m ² Development photosensitive material. 10. As the residual organic solvent during thermal development includes methyl ethyl ketone, heat according to claim 1 or 2 residual methyl ethyl ketone content is characterized in that it is a 0.1mg / m ² ~5mg / m ² Development photosensitive material. 11. As the residual organic solvent during thermal development includes methyl ethyl ketone, heat according to claim 1 or 2 residual methyl ethyl ketone content is characterized in that it is a 0.1mg / m ² ~2mg / m ² Development photosensitive material. 12. includes dimethylacetamide as a residual organic solvent during thermal development, according to claim 1 or 2 remaining dimethylacetamide amount is equal to or is 0.1mg / m ² ~10mg / m ² Photothermographic material. 13. Includes dimethylacetamide as a residual organic solvent during thermal development, according to claim 1 or 2 remaining dimethylacetamide amount is equal to or is 0.1mg / m ² ~5mg / m ² Photothermographic material. 14. includes dimethylacetamide as a residual organic solvent during thermal development, according to claim 1 or 2 remaining dimethylacetamide amount is equal to or is 0.1mg / m ² ~2mg / m ² Photothermographic material. 15. A photothermographic material comprising at least one organic silver salt, a photosensitive silver halide, a reducing agent and a binder on a support and having at least one image forming layer, the support being on the image forming layer side. Is a layer formed by applying a coating liquid containing 30% by mass or more of an organic solvent, and the amount of the residual organic solvent during heat development is 0.1 mg / m ^{2 to} 5 mg / m ² is a photothermographic material. 16. The photothermographic material according to claim 15, wherein at least one of the layers formed on the image forming layer side of the support contains at least one high contrast agent. 17. A photothermographic material comprising the photothermographic material according to claim 1, wherein the photothermographic material is exposed from an exposure device, a heat development device, and an exposure device to the heat development device. In the image forming method of exposing and heat developing with an online system consisting of an auto carrier that automatically conveys materials,
An image forming method, wherein the heat developing machine is provided with a preheating section, a heat developing section, a slow cooling section and a deodorizing device. 18. The processing speed (R ₁ ) of the photothermographic material in the auto carrier, the processing speed (R ₂ ) of the photothermographic material in the preheating section of the heat developing machine, and the heat in the heat developing section of the heat developing machine. The processing speed (R ₃ ) of the photosensitive material is
The image forming method according to claim 17, wherein the following relational expression: R ₃ > R ₂ ≧ R ₁ is satisfied. 19. The processing speed (R ₃ ) of the photothermographic material in the heat developing section of the heat developing machine is 21 mm / sec to 100.
20 mm / sec.
The image forming method described in 1 .. 20. The processing speed (R ₃ ) of the photothermographic material in the heat developing section of the heat developing machine is 27 mm / sec to 50 m.
The image forming method according to claim 17, wherein the image forming method is m / sec. 21. The light source for exposure by the exposure device is a laser having a wavelength of 750 to 800 nm, and the main scanning speed on the surface of the photothermographic material is 500 m / sec to 1500 m / sec. 21. The image forming method according to any one of 17 to 20. 22. The light source for exposure by the exposure device is a laser having a wavelength of 750 to 800 nm, and the main scanning speed on the surface of the photothermographic material is 1100 m / sec to 1500 m / sec. Any one of 17-20
The image forming method according to item.