JPH1172867A - Heat developable photosensitive material and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat developable photosensitive material excellent in shelf stability, having high sensitivity and high Dmax, usable in a photomechanical process and exhibiting high-contrast photographic characteristics by incorporating a specified compd. SOLUTION: A compd. represented by formula I, II or III is incorporated into a heat developable photosensitive material contg. at least an org. silver salt, silver halide and a hydrophobic binder. In the formulae I-III, A1 -A5 are groups of nonmetallic atoms required to complete 5- or 6-membered N-contg. heterocyclic rings, each of the rings may contain O or S and may be condensed with a benzene ring or may further have a substituent and R1 -R3 are 1-20C satd. or unsatd. alkyl.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material, and more particularly to a photothermographic material suitable for printing plate making and an image forming method.

[0002]

2. Description of the Related Art A photothermographic material for forming a photographic image by using a heat development processing method is disclosed, for example, in US Pat.
No. 04, 3,457,075, and D.I. Morgan and B.A. "Silver System Treated by Heat (Thermall) by Shelly
y Processed Silver System
s) "(Imaging Processes and Materials
d Materials) Neblette Eighth Edition,
Sturge, V.S. Wallworth (Wa
lworth), A.I. Shepp, page 2, 1969. Such a photothermographic material usually contains a reducible silver source (eg, an organic silver salt), a catalytically active amount of a photocatalyst (eg, silver halide), a color tone controlling agent for controlling the color tone of silver, and a reducing agent in a binder matrix. It is contained in a dispersed state. The photothermographic material is stable at room temperature, but at a high temperature after exposure (for example, 80 ° C. or higher)
When heated to a low temperature, silver is generated through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and a reducing agent. This oxidation-reduction reaction is promoted by the catalytic action of the latent image generated by the exposure. The silver formed by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image. Such photothermographic materials have been used for micro-photosensitive materials and X-rays, but are only partially used as photosensitive materials for plate making. It is the Dmax of the resulting image
Is low, and the gradation is soft, so that the image quality is remarkably poor as a photosensitive material for printing plate making. On the other hand, in recent years, scanners and imagesetters using lasers or light-emitting diodes have become widespread, and there has been a strong demand for the development of photothermographic materials having high sensitivity, high Dmax, and high contrast, which are suitable for these output devices.

[0003] Such a high contrast heat-sensitive photosensitive material is disclosed in US Patent Nos. 5,545,505 and 5,54.
As described in US Pat. No. 5,515 and JP-A-9-90550, there is known a method of performing high contrast using a hydrazine derivative. However, such a method has a problem in stability during storage.

[0004] Further, as a hardening agent other than a hydrazine derivative used in a usual liquefaction type photosensitive material, JP-A No.
Heterocyclic quaternary ammonium salts are described in US Pat. No. 4,237,437, JP-A-8-220706, U.S. Pat. Nos. 3,719,494 and 4,115,122. However, whether these techniques can be used for photothermographic materials has not yet been studied.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photothermographic material having excellent storage stability, high sensitivity, high Dmax, and high contrasting photographic characteristics which can be used for printing and plate making. An object of the present invention is to provide an image forming method capable of performing complete dry processing without requiring processing.

[0006]

The above object has been attained by the following constitutions of the present invention.

(1) A photothermographic material comprising at least an organic silver salt, silver halide and a hydrophobic binder, containing a compound represented by the following general formula [Pa], [Pb] or [Pc]: A photothermographic material.

[0008]

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Wherein A ₁ , A ₂ , A ₃ , A ₄ or A ₅ is 5
Represents a group of non-metallic atoms for completing a 6-membered nitrogen-containing heterocycle, the heterocycle may contain an oxygen atom, a nitrogen atom, and a sulfur atom, and the heterocycle is condensed with a benzene ring. Is also good. The _5- to 6-membered nitrogen-containing heterocyclic ring composed of A ₁ , A ₂ , A ₃ , A ₄ or A ₅ may further have a substituent. R ₁ , R ₂ and R ₃ each represent a saturated or unsaturated alkyl group having 1 to 20 carbon atoms.

(2) The photothermographic method according to the above (1), wherein the silver halide contains a metal ion or a complex ion selected from the elements of Groups 6 to 10 of the periodic table. material.

(3) An image forming method, wherein the photothermographic material according to the above (1) or (2) is subjected to a heat treatment after exposure.

Hereinafter, the present invention will be described in detail.

In the photothermographic material of the present invention, the storage stability is improved by using a specific nitrogen-containing heterocyclic compound represented by the above formula [Pa], [Pb] or [Pc] as a high contrast agent. The present invention has been able to provide a completely dry photographic material for printing plate making and an image forming method, which has excellent photographic sensitivity, high sensitivity, high Dmax, and high contrast photographic characteristics.

The formula [Pa], [Pb] or [P
c), A ₁ , A ₂ , A ₃ , A ₄ or A ₅ is 5-6
Represents a group of non-metallic atoms for completing a membered nitrogen-containing heterocycle, the heterocycle may contain an oxygen atom, a nitrogen atom, a sulfur atom, and the heterocycle may be condensed with a benzene ring . ₅ composed of A ₁ , A ₂ , A ₃ , A ₄ or A 5
The 6-membered nitrogen-containing heterocyclic ring may further have a substituent, and examples of the substituent include an alkyl group, an aryl group, an aralkyl group,
Alkenyl, alkynyl, halogen, acyl, alkoxycarbonyl, aryloxycarbonyl, sulfo, carboxy, hydroxy, alkoxy, aryloxy, amido, sulfamoyl, carbamoyl, ureido, amino Group, sulfonamide group, sulfonyl group, cyano group, nitro group, mercapto group, alkylthio group and arylthio group.

Examples of the 5- or 6-membered nitrogen-containing heterocycle composed of A ₁ , A ₂ , A ₃ , A ₄ or A ₅ include pyridine,
Imidazole, thiazole, oxazole, pyrazine,
Examples thereof include a pyrimidine ring, and a pyridine ring is preferable.

In the general formulas [Pa] and [Pb], Bp
Represents a divalent linking group, a divalent linking group is an alkylene,
Arylene, _{alkenylene, -SO 2 -, - SO -} , -
O -, - S -, - CO -, - N (R 6) -, represents what is configured alone or in combination (R ₆ represents an alkyl group, an aryl group, a hydrogen atom). A preferred example is Bp
Represents an alkylene group, alkenylene group, or alkyleneoxy group.

In the general formulas [Pa] and [Pc],
R _1, R ₂ and R ₅ each represent an alkyl group or an aryl group of saturated and unsaturated having 1 to 20 carbon atoms, and these groups may have a substituent, examples of the substituent A ₁ , A ₂ , A ₃ , A ₄ or A ₅ may be the same as those mentioned above.

Preferred examples of R ₁ , R ₂ and R ₅ are an alkyl group having 4 to 10 carbon atoms or a substituted or unsubstituted aryl group, and more preferred examples are a substituted or unsubstituted phenyl group and an unsaturated group. Represents an alkyl group or a phenyl-substituted alkyl group.

[0019] In general formula [Pa], [Pb] or [Pc], X _p ^- is a counter ion necessary to neutralize the charge of the whole molecule, such as chlorine ions, bromine ions, iodine ions, nitrate ions , Sulfate ion, p-toluenesulfonate, oxalate, n _p represents the number of counter ions required to neutralize the charge of the whole molecule, and n _p is 0 in the case of an internal salt. Specific examples of the compounds are shown below.

[0020]

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[0021]

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[0022]

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[0023]

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[0024]

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As more preferred embodiments of the present invention, general formula (I) described in quaternary salt compounds described in US Pat. No. 3,719,494, general formula (I) described in US Pat. No. 4,115,122, Heterocyclic quaternary salt compounds described in U.S. Pat. No. 4,877,723, general formula (I) described in JP-A-4-437, and general formula (I) described in JP-A-8-220706.
(II) (III) and nicotinamide derivatives described in JP-A-7-92598 are preferably used.

In the present invention, the general formulas [Pa] and [Pb]
Or preferably is 1 × 10 ^-1 mol content to 1 × 10 ^-6 mol absence per mole of silver as the addition amount of the compound represented by [Pc], in particular 1 × 10 ^-5 mol to 5 × 10 ^{- Two}
The molar range is a preferable addition amount.

The compound represented by the general formula [Pa], [Pb] or [Pc] of the present invention may be a suitable organic solvent such as alcohols (methanol, ethanol, propanol,
It can be used by dissolving in fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethylsulfoxide, methylcellosolve and the like. In addition, by an already well-known emulsification dispersion method, dissolution is performed using an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, and an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically emulsified and dispersed. An object can be prepared and used. Alternatively, a powder of the compound represented by the general formula [Pa], [Pb] or [Pc] can be dispersed and used by a ball mill, a colloid mill or an ultrasonic wave by a method known as a solid dispersion method.

The light-sensitive material of the present invention has a general formula [Pa], [P
It is preferable to add a nucleation accelerator such as a hydrazine derivative, an amine derivative, an onium salt compound, a disulfide derivative, or a hydroxyamine derivative in combination with the compound represented by b) or [Pc]. Examples of compounds of the nucleation accelerator include JP-A-8-314066, paragraph [0].
062] to [0077] and JP-A-6-2587.
Examples (2-1) to (2-20) described in No. 51
And (3-1) to (3-6), JP-A-7-10442
No. 0, the compound of the general formula I, JP-A-2-103536, page 17, lower right column, line 19 to page 18, upper right column, line 4 and the lower right column, lines 1 to 5; 237538
The thiosulfonic acid compound described in No. 1 is preferably used.
Particularly preferably, the compounds described in JP-A-8-314066 are used.

The addition amount of the nucleation accelerator of the present invention is preferably 1 × 10 ⁻⁶ to 2 × 10 ⁻² mol per mol of silver, and more preferably 1 × 10 ^−5.
２2 × 10 ⁻² mol is more preferred, and 2 × 10 ^-5 −1 × 1
0 ^-2 mol is most preferred.

The photothermographic material of the present invention forms a photographic image using a photothermographic processing method. Examples of such photothermographic materials include, for example, U.S. Pat. Nos. 3,152,904 and 3,457,075, and D.C. Morgan and B.A. Sherry (Sh
ely) "Silver system treated by heat (T
thermally Processed Silver
Systems) "(Imaging Processes
And Materials (Imaging Procedures)
ses and Materials) Neblett
e, 8th edition, Sturge, V.E. Walworth, A .; Shep
p) Edit, page 2, 1969).
As described in the above documents, it is preferable that a developer is incorporated in the photothermographic material of the present invention.

Examples of suitable developers are described in US Pat.
No. 0,448, No. 3,773,512, No. 3,5
No. 93,863 and an investigation report (Research D
isocyanates) 17029 and 29996, and includes: aminohydroxycycloalkenone compounds (eg, 2-hydroxypiperidino-2-cyclohexenone); aminoreductones as precursors of the developer ( redones) esters (eg, piperidinohexose reductone monoacetate); N-hydroxyurea derivatives (eg, Np-
Methylphenyl-N-hydroxyurea); hydrazones of aldehydes or ketones (eg, anthracenaldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (eg, hydroquinone, t-butyl-hydroquinone) , Isopropylhydroquinone and (2,5-dihydroxy-phenyl) methylsulfone); sulfhydroxamic acids (e.g., benzenesulfhydroxamic acid); sulfonamidoanilines (e.g., 4- (N-
Methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (for example, 2-methyl-5- (1-
Phenyl-5-tetrazolylthio) hydroquinone); tetrahydroquinoxalines (e.g., 1,2,3,4-
Amidooxins; Azines (for example, a combination of an aliphatic carboxylic acid arylhydrazide and ascorbic acid); a combination of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine; Hydroxanoic acids; Azines and sulfone Combinations of amidophenols; α-cyanophenylacetic acid derivatives; bis-β-naphthol and 1,3-
5-pyrazolones; sulfonamidophenol reducing agents; 2-phenylindane-1,3-dione and the like; chromans; 1,4-dihydropyridines (e.g., 2,6-dimethoxy-3,
5-dicarbethoxy-1,4-dihydropyridine);
Bisphenols (for example, bis (2-hydroxy-3
-T-butyl-5-methylphenyl) methane, bis (6
-Hydroxy-m-tri) mesitol
l), 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,5-ethylidene-bis (2-t-
Butyl-6-methyl) phenol), ultraviolet-sensitive ascorbic acid derivatives and 3-pyrazolidones. Ultra-high contrast, high Dm by the combination of the hydrazine derivative of the present invention and silver halide containing heavy metal ions or complex ions
Hindered phenols are particularly suitable for achieving an effect of increasing ax and increasing sensitivity without causing an increase in fog. For this selection, dihydroxybenzenes and ascorbic acids have been considered to be suitable for causing high contrast and high sensitivity of hydrazine derivatives in the field of silver halide photosensitive materials processed using a developer. In light of that, it can be said that it is very unique. Examples of the hindered phenols include compounds represented by the following general formula (A).

[0032]

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In the formula, R is a hydrogen atom or a group having 1 carbon atom.
10 alkyl group (e.g., -C ₄ H _9, 2,4,4-
R ′ and R ″ represent an alkyl group having 1 to 5 carbon atoms (eg, methyl, ethyl, t
-Butyl).

Specific examples of the compound represented by the general formula (A) are shown below. However, the present invention is not limited to the following compounds.

[0035]

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[0036]

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The amount of the developer including the compound represented by the formula (A) is preferably 1 × 1 per mol of silver.
It is from 0 ^-2 to 10 mol, especially from 1 x 10 ^{-2 to} 1.5 mol.

The silver halide grains in the present invention function as an optical sensor. In order to suppress white turbidity after image formation and obtain good image quality, the average particle size is preferably small, and the average particle size is 0.20.
μm or less, more preferably 0.03 μm to 0.15 μm
m, particularly preferably 0.03 μm to 0.11 μm. The term "grain size" as used herein means the length of a ridge of a silver halide grain when the silver halide grain is a cubic or octahedral so-called normal crystal. If it is not a normal crystal,
For example, in the case of spherical, rod-shaped, or tabular particles,
It refers to the diameter of a sphere equivalent to the volume of silver halide grains.

The shape of the silver halide grains is not particularly limited, but it is preferable that the ratio occupied by the Miller index [100] plane is high, and this ratio is 50% or more, and more preferably 7%.
It is preferably at least 0%, particularly preferably at least 80%. The ratio of the [100] plane of the Miller index is determined by the T.V. method using the dependence of the adsorption of the sensitizing dye on the [111] plane and the [100] plane. Tani, J .; Imaging Sci. , 29,
165 (1985).

The halogen composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide. Preferred is silver bromide or silver iodobromide. The photographic emulsion used in the present invention is P.I.
Chimie et Physi by Glafkids
que Photographique (PaulMo
ntel, 1967); F. Photographic Emulsion Ch by Duffin
emistry (published by The Focal Press,
1966); L. Zelikman et al
Written by Making and Coating Photo
graphic Emulsion (The Foca
l Press, 1964) and the like. That is, any of an acidic method, a neutral method, an ammonia method and the like may be used, and a method of reacting a soluble silver salt with a soluble halide may be any one of a one-sided mixing method, a double-sided mixing method, and a combination thereof. Good. The silver halide may be added to the image forming layer by any method, in which case the silver halide is arranged close to the reducible silver source. Further, the silver halide may be prepared by converting a part or all of silver in the organic acid silver by a reaction between the organic acid silver and a halogen ion into silver halide, or preparing the silver halide in advance. In advance, this may be added to a solution for preparing an organic silver salt, or a combination of these methods is also possible. The latter is preferred. Generally, it is preferred that the silver halide be contained in an amount of 0.75 to 30% by weight based on the reducible silver source (organic silver salt).

The silver halide used in the present invention preferably contains ions or complex ions of metals belonging to Groups 6 to 10 of the periodic table. The above metals include W, Fe, Co, Ni, Cu, Ru, Rh, P
d, Re, Os, Ir, Pt, and Au are preferable, and among them, Rh, Re, Ru, and Os are preferable.

The transition metal-containing silver halide used in the present invention may be contained in the silver halide grains in a periodic table of 6 to 10.
Transition metals selected from Group III elements can be introduced into the silver halide in complex form. As the transition metal complex used in the present invention, a six-coordinate complex represented by the following general formula is preferable.

In the formula [ML ₆ ] ^m , M is a transition metal selected from the elements of Groups 6 to 10 of the periodic table, L is a bridging ligand, and m is 0, -1, -2 or-.
3 is represented. Specific examples of the ligand represented by L include halides (fluoride, chloride, bromide and iodide), cyanide, cyanate, thiocyanate, selenocyanate, tellurocyanate, azide and aquo. Ligand, nitrosyl, thionitrosyl and the like, preferably aquo, nitrosyl and thionitrosyl. If an aquo ligand is present, it preferably occupies one or two of the ligands. L may be the same or different.

Particularly preferred examples of M are rhodium (Rh), ruthenium (Ru), rhenium (Re) and osmium (Os).

The following are specific examples of the transition metal coordination complex.

1: [RhCl ₆ ] ^3- , 2: [RuCl ₆ ] ^3- , 3: [ReCl ₆ ] ^3- , 4: [RuBr ₆ ] ^3- , 5: [OsCl ₆ ] ^3- , 6: [CrCl 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) ClCN 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- The ion or complex ion of these metals may be one type, or the same type metal and different types of metal may be used in combination of two or more types. The content of these metal ions or complex ions is generally 1 × per mole of silver halide.
10 ^-9 to 1 × 10 ^-2 mol is suitable, and preferably 1 × 10 ⁻² mol.
It is 10 ^-8 to 1 × 10 ^-4 mol. The compound which provides the ion or complex ion of these metals is preferably added during silver halide grain formation and incorporated into silver halide grains, and preparation of silver halide grains, that is, nucleation, growth, and physical ripening It may be added at any stage before and after chemical sensitization, but is particularly preferably added at the stage of nucleation, growth, and physical ripening, more preferably at the stage of nucleation and growth. Preferably, it is added at the stage of nucleation. In the addition, the compound may be added in several divided portions, may be added uniformly in the silver halide grains, or may be added in the form of JP-A-63-29603 and JP-A-2-30.
No. 6236, No. 3-167545, No. 4-76534
No. 6,110-146, 5-273683, and the like, the particles can be contained in the particles with a distribution. Preferably, a distribution can be provided inside the particles. These metal compounds can be added by dissolving in water or a suitable organic solvent (eg, alcohols, ethers, glycols, ketones, esters, amides). A method in which an aqueous solution or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together is added to a water-soluble silver salt solution or a water-soluble halide solution during grain formation, or a silver salt solution and a halide solution are mixed simultaneously. A method of preparing silver halide grains by a method of simultaneous mixing of three liquids, a method of charging a required amount of an aqueous solution of a metal compound into a reaction vessel during grain formation, or a method of preparing silver halide. There is a method in which another silver halide grain doped with metal ions or complex ions in advance is sometimes added and dissolved. In particular, a method of adding an aqueous solution of a powder of a metal compound or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together is added to a water-soluble halide solution. When adding to the surface of the particles, a required amount of an aqueous solution of a metal compound can be charged into the reaction vessel immediately after the formation of the particles, during or at the end of physical ripening, or at the time of chemical ripening.

The photothermographic material of the present invention may be any as long as it can form a photographic image using a heat development process. The photothermographic material of the present invention can be prepared by using a reducible silver source (organic silver salt), a catalytically active silver halide, It is preferable that the photothermographic material contains a hydrazine derivative, a developer and, if necessary, a color tone agent for suppressing the color tone of silver dispersed in a (organic) binder matrix. The photothermographic material of the present invention is stable at room temperature, but has a high temperature after exposure (for example, 80 ° C. or higher).
Developed by heating. Heating generates silver through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a developer. This oxidation-reduction reaction is accelerated by the catalytic action of the latent image generated on the silver halide upon exposure. The silver formed by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas, resulting in the formation of an image. This reaction process proceeds without supplying a processing liquid such as water from the outside.

The photothermographic material of the present invention has at least one photosensitive layer on a support. Although only the photosensitive layer may be formed on the support, it is preferable to form at least one non-photosensitive layer on the photosensitive layer. In order to control the amount or wavelength distribution of light passing through the photosensitive layer, a filter layer may be formed on the same side as or opposite to the photosensitive layer, or a dye or pigment may be included in the photosensitive layer. As the dye, a compound described in Japanese Patent Application No. 7-11184 is preferred. The photosensitive layer 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 the gradation. Various additives may be added to any of the photosensitive layer, the non-photosensitive layer, and other forming layers. The photothermographic material of the invention may contain, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, and a coating aid. Suitable binders are transparent or translucent, generally colorless, and include natural polymer synthetic resins and polymers and copolymers, and other film-forming media such as: gelatin, gum arabic,
Poly (vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid) ), Copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (ester) ), Poly (urethane), phenoxy resin, poly (vinylidene chloride), poly (epoxide),
Poly (carbonate) s, poly (vinyl acetate),
There are cellulose esters and poly (amides). The binder may be coated from water or an organic solvent or emulsion.

The addition of toning agents is very desirable. Examples of suitable toning agents are disclosed in Research Report No. 17029,
There are the following: imides (eg, phthalimide);
Cyclic imides, pyrazolin-5-ones, and quinazolinones (eg, succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline, and 2,4-thiazolidinedione); naphthalimides (eg, , N-hydroxy-1,8-naphthalimide); cobalt complexes (eg, hexamine trifluoroacetate of cobalt), mercaptans (eg, 3-mercapto-1,2,4-triazole); N
-(Aminomethyl) aryldicarboximides (eg, N- (dimethylaminomethyl) phthalimide);
The blocked pyrazoles, isothiuronium (is
othiuronium) derivatives and certain photobleaches (e.g., N, N'-hexamethylene (1
-Carbamoyl-3,5-dimethylpyrazole), 1,
A combination of 8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzothiazole);
Merocyanine dyes (for example, 3-ethyl-5-((3-
Ethyl-2-benzothiazolinylidene (benzothiazolinylidene))-1-methylethylidene) -2-thio-
2,4-oxazolidinedione); phthalazinone, a phthalazinone derivative or a metal salt of these derivatives (for example,
4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, and 2,3-dihydro-1,4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, ,
6-chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate); a combination of phthalazine + phthalic acid; phthalazine (including an adduct of phthalazine), maleic anhydride, and phthalic acid , 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivatives and anhydrides thereof (for example,
A combination with at least one compound selected from phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride); quinazolinediones, benzoxazine, naltoxazine derivatives; benzoxazine-2,4-dione (Eg, 1,3-benzoxazine-2,4-dione); pyrimidines and asymmetric-triazines (eg, 2,4-dihydroxypyrimidine), and tetraazapentalene derivatives (eg,
3,6-dimercapto-1,4-diphenyl-1H, 4
H-2,3a, 5,6a-tetraazapentalene). A preferred toning agent is phthalazone.

The reducible silver source is a silver salt of an organic acid or a heteroorganic acid containing a reducible silver ion source, especially a long chain (1).
An aliphatic carboxylic acid having 0 to 30, preferably 15 to 25 carbon atoms) and a nitrogen-containing heterocyclic ring are preferred. Organic or inorganic silver salt complexes wherein the ligand has a total stability constant for silver ions of 4.0 to 10.0 are also useful. Examples of suitable silver salts are described in Research Disclosure Nos. 17029 and 29996, and include the following: salts of organic acids (eg, gallic acid, oxalic acid, behenic acid, stearic acid, palmitic acid, lauric acid) Carboxyalkylthiourea salt of silver (eg, 1
-(3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc.);
Silver complexes of polymer reaction products of aldehydes and hydroxy-substituted aromatic carboxylic acids (eg, aldehydes (formaldehyde, acetaldehyde, butyraldehyde), hydroxy-substituted acids (eg, salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid; 5,5-thiodisalicylic acid), silver salts or complexes of thioenes (for example, 3
-(2-carboxyethyl) -4-hydroxymethyl-
4- (thiazoline-2-thioene and 3-carboxymethyl-4-thiazoline-2-thioene), imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole, 3-amino-5-benzylthio- Complexes or salts of silver and a nitrogen acid selected from 1,2,4-triazole and benzotriazole; silver salts such as saccharin and 5-chlorosalicylaldoxime; and silver salts of mercaptides. The preferred silver source is silver behenate. The organic silver salt preferably has a silver amount of 3 g / m ² or less. More preferably, it is 2 g / m ² or less.

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 includes a forward mixing method, a reverse mixing method, a simultaneous mixing method, and a method disclosed in JP-A-9-12764.
The controlled double jet method described in No. 3 is preferably used.

Such a photosensitive material may contain an antifoggant. The most effective antifoggant was mercury ion. The use of mercury compounds as antifoggants in photosensitive materials is described, for example, in US Pat.
No. 9,903. However, mercury compounds are environmentally unfriendly. Non-mercury antifoggants include, for example, U.S. Patent Nos. 4,546,075 and 4,45
Antifoggants such as those disclosed in U.S. Pat. No. 2,885 and JP-A-59-57234 are preferred.

Particularly preferred non-mercury antifoggants are US Pat. Nos. 3,874,946 and 4,756,99.
No. 9, such as -C (X ₁ ) (X ₂ )
(X ₃ ) (where X ₁ and X ₂ are halogen (eg, F, C
In the l, Br and I), X ₃ is a heterocyclic compound having one or more substituents represented by hydrogen or halogen). Examples of suitable antifoggants include JP-A-9-90550.
Compounds described in paragraph Nos. [0062] to [0063] are preferably used.

Further, more suitable antifoggants are disclosed in US Pat. No. 5,028,523 and British Patent Application No. 92221.
No. 383.4, No. 9300147.7, No. 931
No. 1790.1.

The photothermographic materials of the present invention include, for example, JP-A-63-159814, JP-A-60-140335, JP-A-63-231437, JP-A-63-259651, and JP-A-6-259561.
3-304242, 63-15245, U.S. Pat. Nos. 4,639,414 and 4,740,455,
No. 4,741,966, No. 4,751,175,
Sensitizing dyes described in the above-mentioned 4,835,096 can be used. Useful sensitizing dyes for use in the present invention include, for example,
Research Disclosure Item1
Item 7643IV-A (p.23, December 1978), Item 1831X (p.437, August 1978)
Or cited in the literature cited. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, JP-A-9-34078, 9-54409, 9-8067
The compound described in No. 9 is preferably used.

The support used in the present invention may be paper, synthetic paper, paper laminated with a synthetic resin (eg, polyethylene, polypropylene, polystyrene), plastic film (eg, polyethylene terephthalate, polycarbonate, polyimide, nylon, cellulose triacetate). A metal plate (for example, aluminum, an aluminum alloy, zinc, iron, or copper), paper or a plastic film on which the above-mentioned metal is laminated or vapor-deposited, or the like is used. On the other hand, when a plastic film is passed through a heat developing machine, the dimensions of the film expand and contract. When used as a printing photosensitive material, this expansion and contraction becomes a serious problem when performing precision multicolor printing. Therefore, in the present invention, it is preferable to use a film having a small dimensional change. For example, there are a styrene-based polymer having a syndiotactic structure and a heat-treated polyethylene. Those having a high glass transition point are also preferable, and polyether ethyl ketone, polystyrene, polysulfone, polyethersulfone, polyarylate and the like can be used.

[0057]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.

Example 1 (Preparation of silver halide particles A) 7.5 g of inert gelatin and 10 mg of potassium bromide were dissolved in 900 ml of water, the temperature was adjusted to 35 ° C. and the pH was adjusted to 3.0, and then silver nitrate 74 was dissolved.
g of an aqueous solution containing 370 ml of an aqueous solution containing potassium bromide and potassium iodide in a molar ratio (96/4) of pAg 7.7.
, And added over 10 minutes by a controlled double jet method. Thereafter, 0.3 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, the pH was adjusted to 5 with NaOH, and the average particle size was 0.0.
Cubic silver iodobromide grains having a size of 6 μm, a variation coefficient of the projected diameter area of 8%, and a [100] face ratio of 87% were obtained. This emulsion was subjected to coagulation sedimentation using a gelatin coagulant and desalting treatment, and then 0.1 g of phenoxyethanol was added to the emulsion to give a pH of 5.9 and a pAg of 7.5.
Was adjusted.

(Silver halide grains B, C, D, E, F,
Preparation of G and H) In the preparation of silver halide grains A, silver halide grains A were added except that heavy metals (doped metals) were added as shown in Table 1 over 5 minutes simultaneously with the start of silver nitrate addition.
Was prepared in exactly the same way as in the preparation of

According to the method of Example 1 of JP-A-9-127463, silver behenate was prepared in the following manner.

Preparation of Na Behenate Solution 34 g of behenic acid was added to 340 ml of isopropanol for 65 days.
Dissolved at ° C. Next, a 0.25N aqueous sodium hydroxide solution was added thereto with stirring so as to have a pH of 8.7. At this time, about 400 ml of the sodium hydroxide aqueous solution was required. Next, this sodium behenate aqueous solution was concentrated under reduced pressure to adjust the concentration of sodium behenate to 8.9% by weight.

Preparation of Silver Behenate A 2.94M silver nitrate solution was added to a solution of 30 g of ossein gelatin in 750 ml of distilled water, and the silver potential was adjusted to 4%.
00 mV. At this time, 374 ml of the above sodium behenate solution was added at a speed of 44.6 ml / min at a temperature of 78 ° C. using a controlled double jet method, and at the same time, a 2.94 M silver nitrate aqueous solution was supplied with a silver potential of 400 m.
V. The amounts of sodium behenate and silver nitrate used at the time of addition were 0.092 mol, respectively.
It was 101 mol.

After the addition was completed, the mixture was further stirred for 30 minutes, and the water-soluble salts were removed by ultrafiltration.

Preparation of Photosensitive Emulsion To this silver behenate dispersion, 0.01 mol of each of the above-mentioned silver halide emulsions was added, and 100 g of a solution of polyvinyl acetate in n-butyl acetate (1.2 wt%) was further stirred.
Is gradually added to form a floc of the dispersion, water is removed, water is further washed twice and water is removed, and then 2.5 wt% of butyl acetate and isopropyl alcohol of polyvinyl butyral (average molecular weight: 3000) are added. After stirring, 60 g of a 1: 2 mixed solution of the above was added, and 37.5 g of polyvinyl butyral (average molecular weight: 4000) and 150 g of isopropyl alcohol were added to and dispersed in the thus obtained mixture of behenic acid and silver halide.

The following layers were sequentially formed on a heat-treated polyethylene terephthalate support to prepare a sample.

The drying was performed at 75 ° C. for 5 minutes each.

Back side coating: A solution having the following composition was applied to a wet thickness of 80 microns.

Polyvinyl butyral (10% isopropanol solution) 150 ml Dye-B 70 mg Dye-C 70 mg

[0069]

Embedded image

Photosensitive layer surface side coating Photosensitive layer 1: A solution having the following composition was coated and the silver amount was 2.0 g / m ^2.
It was applied so that

Silver halide emulsion Table 1 73 g Sensitizing dye-1 (0.1% DMF solution) 2 mg Antifoggant-1 (0.01% methanol solution) 3 ml Antifoggant-2 (1.5% methanol solution) 8 ml Antifoggant-3 (2.4% DMF solution) 5 ml Phthalazone (4.5% DMF solution) 8 ml Developer-1 (10% acetone solution) 13 ml Hardening agent H (1% methanol / DMF = 4: 1 solution: type in Table 1) 2 ml

[0072]

Embedded image

[0073]

Embedded image

[0074]

[Table 1]

Surface protective layer: A solution having the following composition was wetted to a wet thickness.
Coating was performed on each photosensitive layer so as to be 100 microns.

Acetone 175 ml 2-propanol 40 ml methanol 15 ml cellulose acetate 8.0 g phthalazine 1.0 g 4-methylphthalic acid 0.72 g tetrachlorophthalic acid 0.22 g tetrachlorophthalic anhydride 0.5 g sensitometry The light-developable photosensitive material is interposed with an interference filter having a peak at 830 nm, and the light emission time is 10 ^-3 sec.
With a xenon flash light. Thereafter, heat development was performed at 110 ° C. for 15 seconds using a heat drum. Concentration 3.0
The sensitivity was defined as the reciprocal of the amount of exposure that gives
The gradient of the straight line connecting the points of density 0.3 and 3.0 in the characteristic curve is shown as gradation (γ).

Storage stability Condition 1: The obtained sample was treated at 50 ° C. and 20% humidity in an environment of 3%.
After storage for a day, the sensitometry was determined.

Condition 2: The obtained sample was kept at 50 ° C. and 80% humidity.
After storage for 3 days in the same environment, sensitometry was similarly determined.

Evaluation of Image Quality A 830 nm laser diode was exposed with a beam inclined by 13 ° from the vertical plane. Then, image quality was evaluated by generating halftone dots. 5 points with no fringe. If it was not good, it was evaluated by a 5-point method of 3, 2, and 1 points. Note that three or more points are at a practical level as a printing photosensitive material. Table 2 shows the evaluation results.
Shown in

[0080]

[Table 2]

From the results shown in Table 2, it can be seen that the sensitivity and Dmax are high, the gamma is high, the image quality is high, and the processing variability is small and good.

[0082]

According to the present invention, a photothermographic material having excellent storage stability, high sensitivity and high Dmax and exhibiting high contrast photographic characteristics which can be used for printing plate making can be obtained.

Claims (3)

[Claims] 1. A photothermographic material comprising at least an organic silver salt, silver halide and a hydrophobic binder, comprising a compound represented by the following formula [Pa], [Pb] or [Pc]. A photothermographic material comprising: Embedded image [Wherein A ₁ , A ₂ , A ₃ , A ₄ or A ₅ represents a non-metallic atomic group for completing a 5- to 6-membered nitrogen-containing heterocyclic ring;
The hetero ring may contain an oxygen atom, a nitrogen atom and a sulfur atom, and the hetero ring may be condensed with a benzene ring. The _5- to 6-membered nitrogen-containing heterocycle composed of A ₁ , A ₂ , A ₃ , A ₄ or A ₅ may further have a substituent. R ₁ , R ₂
And R ₃ each represents a saturated or unsaturated alkyl or aryl group having 1 to 20 carbon atoms. ] 2. The photothermographic material according to claim 1, wherein the silver halide contains a metal ion or a complex ion selected from the elements of Groups 6 to 10 of the periodic table. 3. An image forming method comprising subjecting the photothermographic material of claim 1 or 2 to heat treatment after exposure.