JP2002014437A - Heat developable recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable recording material for plate making and printing having high contrast gradation, low fog and high sensitivity. SOLUTION: In the heat developable recording material with a recording layer containing a non-photosensitive organic silver salt, photosensitive silver halide and a reducing agent on the base, the recording layer or at least one layer adjacent to the recording layer contains a contrast enhancer of formula (1) or (2) and an acid anhydride.

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 more particularly to a heat-developable recording material having high gradation, low fog density and high sensitivity.

[0002]

2. Description of the Related Art Conventionally, in the field of printing plate making and medical treatment, waste liquids caused by wet processing of image recording materials have been a problem in terms of workability. Weight loss is strongly desired. Therefore, there is a need for a technique relating to a photothermographic recording material for photographic use, which allows efficient exposure with a laser imagesetter or laser imager and can form a high-resolution, clear black image. Such techniques include, for example, U.S. Pat. Nos. 3,152,904 and 3,48.
7,075 and D.C. “Dry Silver Photographic Materials (Dry Silver P) by Morgan
photographic Materials) ”(H
andbook of Imaging Materi
als, Marcel Dekker, Inc. 48,
1991), a heat-developable recording material containing an organic silver salt, a photosensitive silver halide, a reducing agent and a binder on a support is known.

These heat-developable recording materials form a photographic image by heat-development processing, and include a reducible silver source (organic silver salt), a photosensitive silver halide, a reducing agent and, if necessary, a silver tone. Is normally contained in a (organic) binder matrix in a dispersed state. This photothermographic material is stable at room temperature, but is developed by heating to a high temperature (for example, 80 to 150 ° C.) after exposure. By heating, silver is generated through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. 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, where the image is formed. This reaction process proceeds without supplying a processing liquid such as water from the outside.

In the case where a heat-developed recording material is used as a printing original for printing on a printing plate, a recording material having a high gradation is required for the purpose of improving the reproducibility of a halftone photographic original.
Means for imparting high contrast to the heat-developable silver recording material are described in JP-A-11-511571 and JP-A-11-119.
372, JP-A-11-231459, JP-A-11-
It is disclosed that a substituted alkene compound described in No. 327077 or the like or a hydrazine compound described in Japanese Patent Application Laid-Open No. 10-512061 is used as a high contrast agent, but most of these compounds generally have a minimum concentration. (Dm
There is a problem that the density of the non-image portion, which is referred to as "in) increases, that is, fog density fluctuation is accompanied.

[0005] The use of mercury compounds to control these fogs is disclosed in US Pat.
No. 903. However, the use of mercury compounds has a problem that is unfavorable in terms of environmental suitability. On the other hand, as non-mercury antifoggants, for example, U.S. Pat. Nos. 4,546,075 and 4,452,885;
JP-A-59-57234, U.S. Pat.
No. 46, No. 4,756,999, JP-A-9-288
No. 328, No. 9-90550, U.S. Pat.
8,523, European Patent Nos. 600,587 and 60
Compounds disclosed in US Pat. No. 5,981, No. 631,176 and the like are known, but when these compounds are used, the maximum density (Dmax) and sensitivity are largely suppressed, and There is a problem that the effect of the agent cannot be sufficiently exhibited, and early improvement is demanded.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide a thermal printing plate having a high gradation, low fog, and high sensitivity. An object of the present invention is to provide a development recording material.

[0007]

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

[0008] 1. In a heat-developable recording material having a recording layer containing a non-photosensitive organic silver salt, a photosensitive silver halide and a reducing agent on a support, the recording layer or at least one layer adjacent to the recording layer has the general formula (1) Or (2), a heat-developable recording material characterized by containing a contrast agent and an acid anhydride.

[0009] 2. In a heat-developable recording material having a recording layer containing a non-photosensitive organic silver salt, a photosensitive silver halide and a reducing agent on a support, the recording layer or at least one layer adjacent to the recording layer has the general formula (3) And (6) a heat-developable recording material comprising at least one high-contrast agent and an acid anhydride.

[0010] 3. In a heat-developable recording material having a recording layer containing a non-photosensitive organic silver salt, a photosensitive silver halide and a reducing agent on a support, the recording layer or at least one layer adjacent to the recording layer has the general formula (1) Or (2) a heat-developable recording material comprising a contrast agent and a sulfonium salt compound.

4. In a heat-developable recording material having a recording layer containing a non-photosensitive organic silver salt, a photosensitive silver halide and a reducing agent on a support, the recording layer or at least one layer adjacent to the recording layer has the general formula (3) And (6) a heat-developable recording material comprising at least one high-contrast agent and a sulfonium salt compound.

In the heat-developable recording material according to the present invention,
A recording layer containing a non-photosensitive organic silver salt, a photosensitive silver halide, and a reducing agent or at least one layer adjacent to the recording layer contains at least one kind of high contrast selected from the general formulas (1) to (6). One of the features is that an agent is contained.

In the general formula (1), specific examples of the substituent which is not a hydrogen atom among R ₁₁ and R ₁₂ include a hydroxy group and —O ⁻ K ⁺ , —O ⁻ Na ⁺ , and —O ^−. (Zn
²⁺⁾ _1/2, etc. metal salts, methoxy group, an ethoxy group, a propoxy group, a butoxy group, an alkyloxy group such as a nonyloxy group, a phenoxy group, substituted phenoxy group, an aryloxy group such as a naphthyl group, a pyridyloxy group, etc. Heterocyclic oxy group, mercapto group and metal salts thereof, alkylthio group such as methylthio group, propylthio group, arylthio group such as phenylthio group, amino group, substituted amino such as methylamino group, ethylamino group, dimethylaminophenylamino group And the like. Preferably, a combination in which either one is a hydroxy group or -OM (M is an alkali metal such as Na or K) and the other is a hydrogen atom.

In the general formula (2), R ₂₁ represents a monovalent substituent, and specific examples of R ₂₁ include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group and an n-butyl group. An alkyl group such as an iso-butyl group, a tert-butyl group, a nonyl group, a cycloalkyl group such as a cyclopentyl group and a cyclohexyl group, a phenyl group, a substituted phenyl group, a naphthyl group, a pyridine, a thiophene, a morpholine,
Examples include a heterocyclic group obtained by removing a hydrogen atom from thiazole, benzothiazole, or the like, a trityl group, an ethoxycarbonyl group, a methylthiomethyl group, a diisopropylamino group, a diphenylamino group, and the like. R ₂₂ represents a hydrogen atom, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, or a substituted alkenyl group, and specific examples of R ₂₂ include
Hydrogen atom, methyl group, ethyl group, n-butyl group, iso
And heterocyclic groups such as -butyl group, tert-butyl group, vinyl group, cyclohexyl group, cyclohexenyl group, maleimide group, phthalimide group, succinimide group, morpholino group, piperidyl group, pyridyl group, and thenoyl group.

In the general formula (3), specific examples of the substituent which is not a hydrogen atom among R ₃₁ and R ₃₂ include a hydroxy group and —O ⁻ K ⁺ , —O ⁻ Na ⁺ , and —O ^−. (Zn
²⁺⁾ _1/2, etc. metal salts, methoxy group, an ethoxy group, a propoxy group, a butoxy group, an alkyloxy group such as a nonyloxy group, a phenoxy group, substituted phenoxy group, an aryloxy group such as a naphthyl group, a pyridyloxy group, etc. Heterocyclic oxy group, mercapto group and metal salts thereof, alkylthio group such as methylthio group, propylthio group, arylthio group such as phenylthio group, amino group, substituted amino such as methylamino group, ethylamino group, dimethylaminophenylamino group And the like. Preferably, a combination in which either one is a hydroxy group or -OM (M is an alkali metal such as Na or K) and the other is a hydrogen atom. R _{33 to} R ₃₆ represent a hydrogen atom or a monovalent substituent. R _{33 to} R ₃₆ may be bonded to adjacent substituents to form a ring. R _{33 to} R ₃₆ are preferably a hydrogen atom or an electron-withdrawing substituent such as a halogen, a cyano group, an alkylcarbonyl group, or an alkyloxycarbonyl group. L ₃₁ is, - (C = O) - , or -
(SO ₂ ) —, and L ₃₂ represents —O—, —S—, —NR
_37- (R ₃₇ is a hydrogen atom, an alkyl group, a substituted alkyl group,
Represents an aryl group), - CR ₃₈ R ₃₉ - is (R _38, R ₃₉ are each a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group), preferably -O -, - NH -, -
N (CH ₃ ) —.

In the general formula (4), R₄₁, R₄₂of
Specific examples of the substituent which is not a hydrogen atom include
A droxy group and -O^-K⁺, -O^-Na⁺, -O^-(Zn
²⁺)_{1 / 2}Metal salts such as methoxy, ethoxy,
Alkyloxy, butoxy, nonyloxy, etc.
Si group, phenoxy group, substituted phenoxy group, naphthyl group, etc.
Heterocycles such as aryloxy and pyridyloxy groups
Xyl group, mercapto group and its metal salts, methylthio
Group, alkylthio group such as propylthio group, phenylthio
Arylthio, amino, methylamino, d
Placement of tylamino group, dimethylaminophenylamino group, etc.
And substituted amino. Preferably, either one
Is a hydroxyl group or -OM (M is Na, K, etc.)
Metal) and the other is a hydrogen atom
You. R₄₃~ R₄₆Is preferably a hydrogen atom or a halogen atom
, Cyano group, alkylcarbonyl group, alkyloxy
An electron-withdrawing substituent such as a carbonyl group. L₄₁Is
-(C = O)-or-(SO _Two)-, L
₄₂Is -O-, -S-, -NR₄₇− (R₄₇Is a hydrogen atom,
Represents an alkyl group, a substituted alkyl group or an aryl group),
Or -CR₄₈R₄₉− (R₄₈, R ₄₉Is a hydrogen atom,
(Representing an alkyl group, a substituted alkyl group, and an aryl group)
And preferably -O-, -NH-, -N (CH_Three)-
No.

In the general formula (5), R ₅₁ represents a monovalent substituent, and the structure of R ₅₁ is arbitrary, but is preferably a phenyl group, a substituted phenyl group, a nitrogen-containing heterocyclic group, or a sulfur-containing heterocyclic group. Is mentioned. Specific examples of R ₅₁ include a methyl group,
Ethyl group, n-propyl group, iso-propyl group, n-
Butyl group, iso-butyl group, tert-butyl group, alkyl group such as nonyl group, cycloalkyl group such as cyclopentyl group and cyclohexyl group, phenyl group, substituted phenyl group, naphthyl group, maleimide group, phthalimide group, succinimide group, Examples include a heterocyclic group such as a morpholino group, a piperidyl group, a pyridyl group, and a thenoyl group, a trityl group, an ethoxycarbonyl group, a methylthiomethyl group, a diisopropylamino group, and a diphenylamino group.

In the general formula (6), R ₆₁ represents an alkyl group or a substituted alkyl group, specifically, a methyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, a trityl group, Tri- (4-methoxyphenyl)
Examples include a methyl group and a tri- (4-methylphenyl) methyl group. R ₆₂ represents an alkenyl group, a substituted alkenyl group, or a heterocyclic group; specifically, an alkenyl group such as a vinyl group, a 1-propenyl group, an isopropenyl group, a 1-cyclohexenyl group, and a substituent Having a substituted alkenyl group, a maleimide group, a phthalimide group, a succinimide group, a morpholino group, a piperidyl group,
And heterocyclic groups such as a pyridyl group and a thenoyl group.

Hereinafter, specific compounds of the high contrast agents represented by formulas (1) to (6) of the present invention will be exemplified, but the present invention is not limited thereto.

[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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[0025]

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[0026]

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Each of the compounds represented by the general formulas (1) to (6) can be synthesized and obtained by a method known to those skilled in the art. Further, the addition amount of the compound according to the present invention, the optimal amount varies depending on the particle size of the silver halide grains, the halogen composition, the degree of chemical sensitization, the type of the inhibitor, etc., but is not uniform,
Generally, the range is preferably about 10 ^-6 mol to 10 ^-1 mol, particularly preferably 10 ^-5 mol to 10 ^-2 mol, per mol of silver halide. Upon adding the above compound, water or an organic solvent can be appropriately selected, dissolved in them, and added.

The invention according to claims 1 and 2 is characterized in that an acid anhydride is used together with the high contrast agent of the present invention.

The acid anhydride used in the present invention may be any as long as it has at least one acid anhydride group (—CO—O—CO—), and there is no limitation on the number, molecular weight, etc. of the acid anhydride groups. However, a compound represented by the general formula [B] is preferable.

[0030]

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In the general formula [B], Z represents an atom group necessary for forming a monocyclic or polycyclic system. These ring systems may be unsubstituted or substituted. Examples of the substituent include an alkyl group (for example, methyl, ethyl,
Hexyl), an alkoxy group (eg, methoxy, ethoxy, octyloxy), an aryl group (eg, phenyl, naphthyl, tolyl), a hydroxy group, an aryloxy group (eg, phenoxy), an alkylthio group (eg, methylthio, butylthio), Arylthio group (eg, phenylthio), acyl group (eg, acetyl, propionyl, butyryl), sulfonyl group (eg, methylsulfonyl, phenylsulfonyl), acylamino group, sulfonylamino group, acyloxy group (eg, acetoxy, benzoxy), carboxyl Group, cyano group,
Includes sulfo groups and amino groups. As the substituent,
Those containing no halogen atom are preferred.

Hereinafter, specific examples of these acid anhydrides will be shown, but the present invention is not limited thereto.

[0033]

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[0034]

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The preferable addition amount is 10 ^-6 to 10 ^-1 mol /.
m ^2, particularly preferably from 10 ^-4 to 10 ^- in the range of ² mol / m ^2.

These acid anhydrides may be used alone or in combination of two or more. In the present invention, an acid anhydride can be added together with a high contrast agent to any layer on the recording side of the support such as a recording layer, a surface protective layer, an intermediate layer, an antihalation layer, and an undercoat layer. It can be added to one layer or two or more layers.

Among the compounds represented by the above general formula [B], among the aliphatic dicarboxylic anhydrides, preferred are succinic anhydrides and glutaric anhydrides, and cyclic aliphatic dicarboxylic acid Anhydrides such as 1,2-cyclopentanedicarboxylic anhydride, 1,2-cyclohexanedicarboxylic anhydride, and hydrogenated phthalic anhydride are preferred. Particularly preferred are 1,2-cyclohexanedicarboxylic anhydride and hydrogenated phthalic anhydride. Among these cyclic aliphatic dicarboxylic anhydrides, a trans-form is preferred. Among them, 1,2-cyclohexanedicarboxylic anhydride is particularly preferred, and a trans-form is particularly preferred.
Examples of particularly preferred hydrogenated phthalic anhydride include:
In addition to those mentioned in the compound examples, 1,2,3,6
-Tetrahydrophthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, maleated methylcyclohexene tetrabasic anhydride,
Endomethylene tetrahydrophthalic anhydride, methyl endomethylenetetrahydrophthalic anhydride, exo-
3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride.

Examples of these aliphatic dicarboxylic acid anhydrides include, in addition to those mentioned in the above compound examples, chlorendic anhydride, bicyclo [2,2,2] oct-7-
Ene-2,3,5,6-tetracarboxylic anhydride, N-
Carboxybenzyloxy-L-aspartic anhydride and endo-bicyclo [2,2,2] oct-5-ene-2,3-dicarboxylic anhydride.

The invention according to claim 3 or 4 is characterized in that a sulfonium salt is used together with a high contrast agent.

In the heat-developable recording material according to the present invention, by containing a sulfonium salt as a non-halogen type radical generator together with a high contrast agent, high fever and low fog during long-term storage can be obtained. It has become possible to provide a developed recording material.

The sulfonium salt compound that can be used in the heat-developable recording material according to the present invention is not particularly limited in structure, but is preferably a compound having a small absorption in the near ultraviolet region from 350 nm to 400 nm. Specific compounds include triphenylsulfonium bromide, triphenylsulfonium chloride, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium trifluoromethylsulfonate, triphenylsulfonium nonafluorobutylsulfonate, triphenylsulfonium Triphenylsulfonium salts such as hexafluoroantimonate and diphenyl-4-methoxyphenylsulfonium trifluoromethylsulfonate, diphenyl-4-methoxyphenylsulfonium hexafluoroantimonate, diphenyl-4-methoxyphenylsulfonium trifluoromethylsulfonate having a substituent introduced into the phenyl group of these compounds. 4-methylphenylsulfonium trifluoromethylsulfonate, diphe Le-2,4,6-trimethylphenyl sulfonium trifluoromethylsulfonate, diphenyl -4-tert
-Butylphenylsulfonium trifluoromethylsulfonate, diphenyl-4-phenylthiophenylsulfonium trifluoromethylsulfonate and the like. Other preferred compounds include compounds represented by the following general formula (S).

[0042]

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In the formula, R ₁ , R ₂ and R ₃ each represent the same or different, and each represents an aliphatic group or an aromatic group which may contain a hetero atom. Two of R _{1 to} R ₃ may be bonded to each other to form a ring, or may be bonded to one or more other sulfonium bases. X ^- represents an arbitrary counter anion.

As the aliphatic group represented by R ₁ , R ₂ or R ₃ , for example, a branched or straight-chain alkyl group having 1 to 10 carbon atoms (for example, methyl group, ethyl group, propyl group, butyl group) Group, pentyl group, iso-pentyl group, 2-
An ethylhexyl group, an octyl group, a decyl group, etc., an alkenyl group having 3 to 10 carbon atoms (for example, a 2-propenyl group, a 3-butenyl group, a 1-methyl-3-propenyl group,
3-pentenyl group, 1-methyl-3-butenyl group, 4-
Hexenyl group) and an aralkyl group having 7 to 10 carbon atoms (eg, benzyl group, phenethyl group, etc.).

The aromatic group represented by R ₁ , R ₂ or R ₃ is preferably a phenyl group or a naphthyl group, and the aromatic heterocyclic group is preferably a thienyl group, a furanyl group, a pyrazolyl group or the like. These optionally include alkyl groups having up to 5 carbon atoms (eg, methyl),
Alkoxyl groups having up to 5 carbon atoms (eg,
Methoxy), halogen atoms (eg, chlorine, bromine, iodine and fluorine), carboxy groups having up to 5 carbon atoms, cyano and nitro groups, or any combination thereof.

Examples of the counter anion represented by X ⁻ include a halide anion, HSO ₄ ⁻ , and a halogen-containing complex anion such as an inorganic anion such as tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate and hexafluoroantimonate. , Formula R ₁
CO ₂ ^- and R ₁ SO ₃ ^- (wherein, R ₁ represents an alkyl group or an aryl group, further, may have a substituent.)
And the like are used.

In the sulfonium salt used in the present invention, R ₁ , R ₂ , and R ₃ are each preferably an aromatic group, and particularly preferably, R ₁ , R ₂ , and R ₃ are each a phenyl group. The triarylsulfonium salt is preferably used. However, the phenyl group may have a substituent or may be unsubstituted.

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

[0049]

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[0050]

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[0051]

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[0052]

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The amount of the compound represented by formula (S) used in the present invention is 0.001 to 0.1 mol / m.
² , preferably 0.005 to 0.05 mol / m ² . The compound may be contained in any of the constituent layers of the heat-developable recording material according to the present invention together with a high contrast agent.

In the heat-developable recording material according to the present invention, a known antifoggant may be used in a small amount, if necessary, together with the acid anhydride and the sulfonium salt compound. Preferred examples of other antifoggants that can be used in the present invention include halogenated antifoggants. The combined use of a halogenated antifoggant compound is particularly effective for image stability after image recording, and is also effective for ordinary antifoggant function and storage stability. Particularly preferred antifoggant compounds (aryl compounds) are represented by the following general formula (C).

General formula (C) Ar— (SO ₂ ) _y —CH _{3 —n} X _{n wherein} Ar is an aromatic or heteroaromatic group, y is 0 or 1,
X represents a halogen atom, and n represents an integer of 1, 2 or 3.

Specific examples of the compound represented by the general formula (C) are described in US Pat. Nos. 4,546,075 and 4,75.
No. 6,999, No. 4,452,885, No. 3,8
74,946 and 3,955,982. Other halogen compounds considered to be useful in the present invention include dihalogen compounds as described in JP-A-59-57234. The halogenated antifoggant compound is contained in the recording layer or the surface protective layer in an amount of from 5 × 10 ^{−4 to} 0.5 mol, preferably from 5 × 10 ^{−3 to} 5 × 10 ⁻² mol, per 1 mol of the total silver. It is contained in the amount of. Representative examples of the halogenated antifoggant compound preferably used are listed below.

[0057]

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[0058]

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[0059]

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Next, the components of the heat-developable recording material according to the present invention will be described below. The non-photosensitive organic silver salt according to the present invention is a reducible silver source, and a silver salt of an organic acid and a hetero organic 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 heterocyclic carboxylic acid having a nitrogen-containing heterocyclic ring are preferably used. Further, when the ligand is 4.0
Organic or inorganic silver salt complexes having a total stability constant for silver ions of １10.0 are also useful.

Examples of the non-photosensitive organic silver salt preferably used in the present invention include Research Diss.
Closure (hereinafter simply referred to as RD) No. 1702
9 and 299963, and include: silver salts of fatty acids (eg, silver salts of gallic acid, oxalic acid, behenic acid, arachidic acid, stearic acid, palmitic acid, lauric acid, etc.); silver (E.g., 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc.); polymerization reaction formation of an aldehyde with a hydroxy-substituted aromatic carboxylic acid Complex (e.g., aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.) and hydroxy-substituted aromatic carboxylic acids (e.g., salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid, etc.) And a silver salt or complex of a thione (e.g., 3- (2-carbo) (Silethyl) -4-hydroxymethyl-4-thiazoline-2-thione and 3-carboxymethyl-4-thiazoline-2-thione), imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole, Complexes or salts of silver and nitrogen acids selected from -amino-5-benzylthio-1,2,4-triazole and benzotriazole; silver salts such as saccharin and 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, but a forward mixing method, a reverse mixing method, a simultaneous mixing method and the like are preferably used. Further, it is also possible to use a controlled double jet method as described in JP-A-9-127463.

Specifically, 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,
The above series of reaction steps need to be performed while stirring sufficiently using a suitable stirring member so that the inside of the reaction tank becomes uniform.

Usually, the organic silver salt particles contained in the heat-developable recording material are formed in an aqueous mother liquor, and are often mixed with silver halide particles formed in advance. As an outline of the most common production process, a mother liquor is removed by a centrifugal dehydration operation or the like, and a slurry or a wet cake is obtained. Next, a dry powder is formed through a drying process, dispersed in an organic solvent and / or a binder, and applied to a support after preparing a solution. The production of an organic silver composition of a conventionally known heat development recording material can be performed in an air atmosphere. In the present invention, it is preferable to carry out the liquid preparation step under a high nitrogen concentration atmosphere, from the viewpoints of storage stability, in particular, improvement of image storability after heat development, in addition to suppression of fog and high sensitivity. Examples of the drying device include a vacuum dryer, a freeze dryer, a hot-air heating box dryer, a flash dryer, a spray dryer, and the like. In particular, a flash dryer is preferably used in the present invention. As a flash dryer, straight pipe type,
In order to increase the residence time, there are a type in which the middle body is enlarged, a swirling flow type, and the like, and a swirling flow type is preferably used. Also,
The airflow speed when operating the airflow dryer is 2.0
N · m ³ / min or more is preferred, and 5.0 N · m ³ / mi
n or more, more preferably 8.0 N · m ³ / min.
The above is preferred. Further, the hot air temperature is preferably 20 ° C. or higher, more preferably 40 ° C. or higher, and further preferably 60 ° C. or higher. The drying operation may be performed twice or more from the viewpoint of productivity, prevention of overdrying, and the like.

Next, the photosensitive silver halide of the present invention will be described. The photosensitive silver halide of the present invention functions as an optical sensor. In the present invention, in order to suppress white turbidity after image formation and to obtain good image quality, the average grain size of the photosensitive silver halide grains is preferably small, and the average grain size is preferably 0.1 μm or less, more preferably. Is 0.01 μm to 0.1 μm, particularly 0.02 μm to 0.2 μm.
08 μm is preferred. Here, the particle size refers to the diameter (equivalent circle diameter) of a circle having the same area as an individual particle image observed with an electron microscope. Further, the silver halide is preferably monodispersed. Here, the monodispersion means that the degree of monodispersion determined by the following formula is 40% or less. The particle size is more preferably 30% or less, and particularly preferably 20% or less.

Monodispersity = (standard deviation of particle size) / (average value of particle size) × 100 The shape of silver halide grains is not particularly limited, but the proportion occupied by the Miller index [100] plane is high. It is preferable that this ratio is 50% or more, further 70% or more,
In particular, it is preferably at least 80%. Miller index [1
The ratio of the [00] plane is determined by utilizing the dependence of the adsorption of the sensitizing dye on the [111] plane and the [100] plane. Tan
i. Imaging Sci. , 29, 165 (1
985).

Another preferred form of silver halide is tabular grains. The term “tabular grain” as used herein means an aspect ratio represented by r / h of 3 or more, where the square root of the projected area is r μm and the vertical thickness is h μm. Among them, the aspect ratio is preferably 3 or more and 50 or less. Further, the particle size is preferably 0.1 μm or less, more preferably 0.01 μm to 0.08 μm. These are described in U.S. Pat. Nos. 5,264,337, 5,314,798, and 5,320,958, and can easily obtain target tabular grains.

The halogen composition is not particularly limited.
Any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide may be used. The photographic emulsion used in the present invention is P.I. Chimie et by Glafkids
Physique Photographique
(Paul Montel, 1967);
F. Photographic Em by Duffin
ulsion Chemistry (The Foca
l Press, 1966); L. Zelik
Making and Coat by man et al
ing Photographic Emulsion
(The Focal 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 the formation of reacting a soluble silver salt and a soluble halide is performed using any one of a one-side mixing method, a double-mixing method, a combination thereof and the like. Is also good.

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

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

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

The following are specific examples of transition metal complex ions, but the present invention is not limited thereto.

[0073] 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 and different metals. You may. The content of these metal ions, metal complexes or metal complex ions, generally is suitably 1 × 10 ^-9 ~1 × 10 ^-2 mol per mol of silver halide, preferably 1 × 10 ^{- It is 8} to 1 × 10 ^-4 mol.

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

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

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

At the time of addition to the particle surface, a required amount of an aqueous solution of a metal compound may be charged into the reaction vessel immediately after the formation of the particles, during or during physical ripening, or at the time of chemical ripening.

In the present invention, the photosensitive silver halide grains may or may not be desalted after grain formation. When desalting is performed, it is known in the art such as a noodle method and a flocculation method. It can be desalted by washing with water in the same manner.

The photosensitive silver halide grains used in the present invention are preferably chemically sensitized. Preferred chemical sensitization methods, as is well known in the art,
Sulfur sensitization, selenium sensitization, and tellurium sensitization can be used. In addition, a noble metal sensitization method or a reduction sensitization method of a gold compound, platinum, palladium, iridium compound or the like can be applied.

As the compounds preferably used in the sulfur sensitization method, selenium sensitization method, and tellurium sensitization method, known compounds can be used, but the compounds described in JP-A-7-128768 and the like can be used. Can be. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides, bis (carbamoyl) tellurides, diacyl tellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, =
Compound having a Te bond, tellurocarboxylates, Te
-Organyltellurocarboxylic esters, di (poly)
Tellurides, tellurides, tellurols, telluroacetals, tellurosulfonates, compounds having a P-Te bond, Te-containing heterocycles, tellurocarbonyl compounds,
An inorganic tellurium compound, colloidal tellurium, or the like can be used.

Compounds preferably used in the noble metal sensitization method include, for example, chloroauric acid, potassium chloroaurate, potassium aurithiocyanate, gold sulfide, gold selenide, US Pat. No. 2,448,060 and British Patent No. No. 618,061 can be preferably used.

Specific compounds used in the reduction sensitization method include, as well as ascorbic acid and thiourea dioxide, for example, stannous chloride, aminoiminomethanesulfinic acid,
Hydrazine derivatives, borane compounds, silane compounds, polyamine compounds and the like can be mentioned. In addition, the emulsion p
Reduction sensitization can be achieved by aging while keeping H at 7 or more or pAg at 8.3 or less. Further, reduction sensitization can be achieved by introducing a single addition portion of silver ion during grain formation.

The heat-developable recording material according to the present invention contains a reducing agent. Examples of suitable reducing agents are described in U.S. Pat.
Nos. 770,448, 3,773,512, 3,593,863, and RD Nos. 17029 and 2nd
9963, and includes the following. Aminohydroxycycloalkenonone compounds (for example, 2-hydroxypiperidino-2-cyclohexenone); aminoreductones (reductones) as precursors of reducing agents
s) esters (eg, piperidinohexose reductone monoacetate); N-hydroxyurea derivatives (eg, Np-methylphenyl-N-hydroxyurea);
Aldehyde or ketone hydrazones (e.g., anthracenaldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (e.g., hydroquinone, t-
Butyl-hydroquinone, isopropylhydroquinone and (2,5-dihydroxy-phenyl) methylsulfone); sulfhydroxamic acids (eg, benzenesulfhydroxamic acid); sulfonamideanilines (eg, 4- (N-methanesulfonamide) Aniline); 2
-Tetrazolylthiohydroquinones (e.g., 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone); tetrahydroquinoxalines (e.g.,
1,2,3,4-tetrahydroquinoxaline); amidooxines; azines (for example, a combination of an arylcarboxylic acid arylhydrazide and ascorbic acid);
Combinations of polyhydroxybenzene and hydroxylamine, reductone or hydrazine; hydroxanoic acids; combinations of azines and sulfonamidophenols; α-cyanophenylacetic acid derivatives; combinations of bis-β-naphthol and 1,3-dihydroxybenzene derivatives; Pyrazolones; sulfonamide phenol reducing agents; 2-phenylindane-1,3-dione and the like; chromans; 1,4-dihydropyridines (eg, 2,6-dimethoxy-3,5-dicarboethoxy-1,4 -Dihydropyridine); bisphenols (for example, bis (2-
Hydroxy-3-t-butyl-5-methylphenyl) methane, bis (6-hydroxy-m-tri) mesitol, 2,2-bis (4-hydroxy-
3-methylphenyl) propane, 4,5-ethylidene-
Bis (2-t-butyl-6-methyl) phenol), ultraviolet-sensitive ascorbic acid derivatives and 3-pyrazolidones. Among them, particularly preferred reducing agents are hindered phenols.

The hindered phenols include compounds represented by the following general formula (A).

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In the formula, R represents a hydrogen atom or a group having 1 to 1 carbon atoms.
Represents an alkyl group having 10 carbon atoms (eg, butyl group, 2,4,4-trimethylpentyl group, etc.), and R ′ and R ″ are each an alkyl group having 1 to 5 carbon atoms (eg, methyl group, ethyl group). , T-butyl group, etc.).

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

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[0089]

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The amount of the reducing agent including the compound represented by the formula (A) is preferably 1 × per mole of silver.
10 ^-2 to 10 mol, particularly preferably 1 × 10 ^{-2 to} 1.5
Is a mole.

The heat-developable recording material according to the present invention includes, for example, JP-A-63-159814 and JP-A-60-140335.
No. 63-231437, No. 63-296551
No. 63-304242, No. 63-15245,
U.S. Pat. Nos. 4,639,414 and 4,740,4
No. 55, No. 4,741,966, No. 4,751,
No. 175 and No. 4,835,096.

Useful sensitizing dyes for use in the present invention are described or cited in, for example, RD Item 17643 IV-A (p. 23, December 1978) and Item 18431 (p. 437, August 1979). 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, an argon ion laser light source is disclosed in JP-A-60-162247 and JP-A-2-4863.
No. 5, U.S. Pat. No. 2,161,331, West German Patent No. 9
For simple merocyanines and helium neon laser light sources described in JP-A-36,071 and JP-A-5-11389, JP-A-50-62425 and JP-A-54-187.
JP-B-48-42172 for trinuclear cyanine dyes described in JP-A Nos. 26 and 59-102229, merocyanines described in JP-A-7-287338, LED light sources and infrared semiconductor laser light sources; Id 51-9609
No. 55-39818, JP-A-62-284343.
Thiacarbocyanines described in JP-A-2-105135, and tricarbocyanines described in JP-A-59-19032 and 60-80841 for an infrared semiconductor laser light source; JP-A-59-1922
No. 42, the general formula (IIIa) of JP-A-3-67242,
Dicarbocyanines containing a 4-quinoline nucleus described in (IIIb) are advantageously selected. Further, the wavelength of the infrared laser light source is 750 nm or more, more preferably 800 n
m or more, in order to cope with a laser in such a wavelength range, Japanese Patent Application Laid-Open Nos. 4-182639 and 5-34414.
No. 32, Tokiko 6-52387, No. 3-10931
No. 5,441,866, JP-A-7-13
Sensitizing dyes described in, for example, No. 295 are preferably used. These sensitizing dyes may be used alone, and a combination of sensitizing dyes is often used particularly for supersensitization. In addition to the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization.

In the heat-developable recording material according to the present invention, in order to suppress or accelerate the development and control, to improve the spectral sensitization rate as in the above-described supersensitization, or to improve the storability before and after the development. Mercapto compounds,
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,
Those represented by r-SS-Ar are preferred. Where 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, naphthymidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellurazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, Triazine, pyrimidine, pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone. The heteroaromatic ring includes, for example, halogen (eg, Br and Cl), hydroxy, amino, carboxy, alkyl (eg, having one or more carbon atoms, preferably 1-4 carbon atoms) and alkoxy (eg, For example, one or more carbon atoms,
(Preferably having 1 to 4 carbon atoms). Examples of the mercapto-substituted heteroaromatic compound include 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 (3
H) -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, but are not limited thereto. The addition amount of these mercapto compounds is preferably in the range of 0.001 to 1.0 mol per mol of silver in the recording layer, more preferably 0.01 to 1.0 mol per mol of silver.
The amount is 0.3 mol.

Binders suitable for the heat-developable recording material according to the present invention are transparent or translucent and generally colorless, and include natural polymers, synthetic polymers and copolymers, and other film-forming media such as gelatin, gum arabic,
Polyvinyl alcohol, hydroxyethyl cellulose,
Cellulose acetate, cellulose acetate butyrate, polyvinylpyrrolidone, casein, starch, polyacrylic acid, polymethyl methacrylate, polymethacrylic acid, polyvinyl chloride, copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene) -Butadiene), polyvinyl acetals,
For example, there are polyvinyl formal, polyvinyl butyral, polyesters, polyurethanes, phenoxy resin, polyvinylidene chloride, polyepoxides, polycarbonates, polyvinyl acetates, cellulose esters, polyamides and the like, which may be hydrophilic or non-hydrophilic.

For the purpose of protecting the surface of the heat-developable recording material according to the present invention and preventing scratches, a non-photosensitive layer may be provided outside the recording layer. The binder used for these non-photosensitive layers may be the same or different from the binder used for the recording layer.

In the present invention, the binder amount of the recording layer is preferably 1.5 to 10 g / m ² in order to increase the thermal development rate. More preferably, 1.7 to 8 g / m
² If it is less than 1.5 g / m ² , the density of the unexposed portion will increase significantly and may not be usable, which is not preferable.

In the heat-developable recording material according to the present invention, it is desirable to use an additive (hereinafter referred to as a color-toning agent) called a color-toning agent, a color-toning agent, and an activator toner together with the above-described components. The color tone agent has a function of participating in the oxidation-reduction reaction between the non-photosensitive organic silver salt and the reducing agent to make the resulting silver image dark, particularly black. Examples of suitable toning agents for use in the present invention are disclosed in RD 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). Preferred toning agents are phthalazone or phthalazine.

The heat-developable recording material according to the present invention preferably has a crosslinking agent from the viewpoint of maintaining the strength of the coating film. At the same time, although the mechanism is unknown, it has a good effect on fog reduction or storage stability.

Examples of the crosslinking agent used in the present invention include various crosslinking agents conventionally used for photographic light-sensitive materials, for example, aldehyde-based, epoxy-based and ethyleneimine described in JP-A-50-96216. , Vinylsulfone, sulfonic ester, acryloyl, and carbodiimide crosslinking agents can be used. Preferred are the following isocyanate compounds, epoxy compounds, and acid anhydrides.

The following general formula (7) which is one of the preferable ones
The isocyanate-based and thioisocyanate-based cross-linking agents represented by Formula (1) will be described.

Formula (7) X = C = NL- (N = C = X) _{v In the} formula, v is 1 or 2, and L may be an alkylene, alkenylene, arylene group or alkylarylene group. X is a divalent linking group, and X is an oxygen or sulfur atom.

In the compound represented by the general formula (7), the aryl ring of the arylene group may have a substituent. Examples of preferred substituents are selected from halogen atoms (eg, bromine or chlorine atoms), hydroxy, amino, carboxyl, alkyl and alkoxyl groups.

The above-mentioned isocyanate-based crosslinking agents are isocyanates having at least two isocyanate groups and adducts thereof (adducts). More specifically, aliphatic diisocyanates and fatty acids having a cyclic group Aromatic diisocyanates, benzene diisocyanates, naphthalene diisocyanates, biphenyl isocyanates, diphenylmethane diisocyanates, triphenylmethane diisocyanates, triisocyanates, tetraisocyanates, adducts of these isocyanates and divalent or 3
Adducts with polyhydric polyalcohols. As a specific example, an isocyanate compound described on pages 10 to 12 of JP-A-56-5535 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-dimethylbenzol, ω, ω′-diisocyanate-1,2
-Dimethylcyclohexane diisocyanate, ω, ω-
Diisocyanate-1,4-diethylbenzol, 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'-triisocyanate Isocyanate,
Tolylene diisocyanate, 1,5-naphthylene diisocyanate; dimer or trimer adducts of these isocyanates (e.g., 2 mol of adduct of hexamethylene diisocyanate, 3 mol of adduct of hexamethylene diisocyanate, 2,4-triene) Adduct of 2 mol of diisocyanate, adduct of 3 mol of 2,4-tolylene diisocyanate); adducts of two or more different isocyanates different from each other selected from these isocyanates; and these isocyanates and divalent or trivalent Adducts with polyvalent polyalcohols (preferably polyalcohols having up to 20 carbon atoms, such as ethylene glycol, propylene glycol, pinacol, trimethylolpropane, etc.) (for example, tolylene diisocyanate and trimethylol) Adduct propane; and adducts of hexamethylene diisocyanate and trimethylolpropane) and the like. Among these, an adduct of an isocyanate and a polyalcohol has a particularly high ability to improve interlayer adhesion and to prevent delamination of the layer, image shift and generation of bubbles. Such a polyisocyanate may be located in any part of the heat-developable recording material. For example, in the support (especially when the support is paper, it can be included in the size composition) of the recording layer side of the support such as a recording layer, a surface protective layer, an intermediate layer, an antihalation layer, and an undercoat layer. It can be added to any layer, and can be added to one or more of these layers.

In the present invention, a dye layer may be provided between the recording layer and the support or on the side opposite to the recording layer. The dye contained in the dye layer needs to have an absorption in the wavelength region of the exposure light source, and 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 is 750 nm to 830 nm.
It preferably has an absorption maximum between nm. Further, the smaller the absorption in the visible region and the near ultraviolet region, the better.

As described above, the structure of the dye that can be used in the present invention is not particularly limited. Examples of the dye that can be preferably used include, for example, those described in
No. 13295, JP-A-8-27859.
No. 2, Nos. 9-230531, No. 11-223898, dyes described in JP-A-11-231364, dihydroperimidine squarate complex dyes described in JP-A-9-509503, JP-A-10-366
No. 95, No. 10-104785, No. 10-20431
The dihydroperimidine squarylium dye according to No. 0,
Squarylium dyes described in JP-A-10-104779 and JP-A-10-207002, JP-A-7-102179
And the like. Also,
Other dyes that can be preferably used in the present invention include compounds represented by the following D-1 to D-9.

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[0107]

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The dyes usable in the present invention include:
It is basically arbitrary and is not limited by the above description. In the present invention, two or more dyes can be used in combination. When two or more 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 opposite side of the recording layer with respect to the support, these dyes should be used in such an amount that the absorption concentration of the dye layer at the exposure wavelength becomes 0.3 or more. Is preferred. More preferably, the amount is such that the absorption concentration is 0.5 or more and less than 2, particularly preferably the absorption concentration is 0.7 or more and less than 1.5. When these dyes are used in a dye layer provided between the support and the recording layer, it is preferable to use the same amount as described above. In addition, these dyes can be added to the recording layer. When these dyes are added to the recording layer, they are preferably used in such an amount that the absorption density of the photosensitive layer at the exposure wavelength is less than 0.6. More preferably, the amount added 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 patent groups cited as examples of preferably usable dyes 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 more 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-
A 24-membered ring is preferred, and a 15- to 21-membered ring is more preferred.

A typical compound is a compound known as a crown ether, wherein Pederson is 1
It was synthesized in 967, and since its unique report, many have been synthesized. These compounds are C.I. J. Pe
derson, Journal of America
n chemical society vol.86
(2495), 7017-7036 (1967);
W. Gokel, S.M. H, Korzeniowsk
i, "Macrocyclic polyethersy
nthesis ", Springer-Vergal,
(1982), Oda, Shono, and Tabushi, "Chemistry of Crown Ethers" Kagaku Doujin (1978), Tabushi, "Host-Guest" Kyoritsu Shuppan (1979), Sasaki, Koga, "Synthetic Organic Chemistry" Vol 45 (6), 571 582 (1987).

In the heat-developable recording material according to the present invention,
If necessary, a matting agent may be contained on the recording layer side or on the opposite 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 and the like, and French Patent Nos. 1 and 2,
No. 96,995, glass powder described in British Patent No. 1,1
Alkaline earth metals or carbonates such as cadmium and zinc described in No. 73,181 can be used as a matting agent. As the organic substance, US Pat. No. 2,322,
037 etc., Belgian Patent No. 625, 45
No. 1 and British Patent Nos. 981, 198, etc., polyvinyl alcohol described in JP-B-44-3643, etc., polystyrene or polymethacrylate described in Swiss Patent No. 330,158, U.S. Pat. Organic matting agents such as polyacrylonitrile described in 3,079,257 and the like and polycarbonate described in U.S. Pat. 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 recording layer, and more preferably the outermost layer viewed from the support. Layer. The method for adding the matting agent used in the present invention may be a method in which the matting agent is dispersed in a coating solution in advance, or a method in which the matting agent is sprayed before the drying is completed after applying the coating solution. May be used. When a plurality of types of matting agents are added, both methods may be used in combination.

In the present invention, a conductive compound such as a metal oxide or a conductive polymer can be contained in the constituent layer for the purpose of improving the chargeability. These may be contained in any of the constituent layers, preferably an undercoat layer,
It is preferably contained in a backing layer, a layer between a recording layer and an undercoat, and the like. In the present invention, US Pat.
The conductive compounds described in Nos. 4,773, columns 14 to 20 are preferably used.

It is preferable that all coating liquids used for coating the heat-developable recording material according to the present invention are 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 may be formed of a plastic film (for example, polyethylene terephthalate, polycarbonate, or the like) in order to prevent deformation of an image after development processing.
Polyimide, nylon, cellulose triacetate, polyethylene naphthalate) are preferred.

Among them, a preferable support is a support made of polyethylene terephthalate (hereinafter abbreviated as PET) and a plastic (hereinafter abbreviated as SPS) containing a styrene-based polymer having a syndiotactic structure. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm. A heat-treated plastic support can also be used. The plastics to be employed include the above-mentioned plastics. The heat treatment of the support means that after forming the support and before the recording layer is applied, the support is heated at a temperature higher than the glass transition point of the support by 30 ° C. or higher, preferably at a temperature higher by 35 ° C. or higher. Preferably, heating is performed at a temperature higher than 40 ° C.

Next, the plastic used for the support according to the present invention will be described. PET is made of polyethylene terephthalate in which all of the polyester components are used. In addition to polyethylene terephthalate, terephthalic acid, naphthalene-2,6-dicarboxylic acid, isophthalic acid, butylene dicarboxylic acid, 5-sodium sulfoisophthalic acid are used as acid components. Modified polyester component such as adipic acid and glycol component such as ethylene glycol, propylene glycol, butanediol, cyclohexanedimethanol, etc. is 10 mol% of the total polyester.
The polyester included below may be used.

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

As the method of forming a film of a support and the method of producing an undercoat used in the present invention, known methods can be used, and preferably, paragraph [0030] of JP-A-9-50094 is used.
To [0070].

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

In the application of the heat-developable recording material according to the present invention,
Roll coating method such as reverse roll coating, gravure roll coating, blade coating,
Wire bar coating, die coating and the like are used. In addition, before drying the already applied layer using a plurality of coaters, or applying the next layer and simultaneously drying a plurality of layers, using a slide coating, curtain coating or an extrusion die coater having a plurality of slits, A simultaneous multilayer coating method in which a plurality of coating liquids are laminated and applied is also used. Of these, the latter is more preferable in that the occurrence of coating failure due to foreign substances brought in from the outside can be prevented. Furthermore, when using the simultaneous multi-layer coating method, in order to prevent mixing between layers, the viscosity at the time of application of the coating liquid of the uppermost layer is set to 0.1 Pa · s or more, Is preferably 0.03 Pa · s or more. Also, when laminated in a liquid state with adjacent layers,
When the solid content dissolved in the coating solution of each layer is hardly soluble or insoluble in the organic solvent contained in the adjacent layer, precipitation occurs at the interface, and as a result, turbulence or turbidity of the coating film is caused. It is preferable that the organic solvent most contained in the coating liquid of each layer is of the same type (the content of the organic solvent commonly contained in each coating liquid in each liquid is larger than that of the other organic solvents). Preferably, an organic solvent such as methyl ethyl ketone (MEK), ethyl acetate, and toluene is used.

After the multi-layer coating, it is preferable to dry as soon as possible, and it is preferable 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 a hot air drying method is particularly preferable.
The drying temperature at that time is preferably 30 to 100 ° C.

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

[0125]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto.

Example 1 << Preparation of heat-developable recording material >> Samples 1 to 14 as heat-developable recording materials were prepared according to the following method.

(Preparation of Subbed PET Support)
A corona discharge treatment of 8 w / m ² · min is applied to both sides of a 125 μm-thick PET film which has been axially stretched and heat-fixed, and the following undercoating solution a-1 is applied to one side to a dry film thickness of 0.8 μm. And then dried to form an undercoat layer A-1. On the opposite surface, an undercoat coating solution b-1 for antistatic processing described below is applied to a dry film thickness of 0.8 μm and dried. Thus, an antistatic subbing layer B-1 was obtained.

[Undercoating Coating Solution a-1] Butyl acrylate (30% by mass), t-butyl acrylate (20% by mass), styrene (25% by mass), 2-hydroxyethyl acrylate (25% by mass) Combined latex liquid (solid content 30%) 270 g 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 1 with water Finish to liters.

[Subbing Coating Solution b-1] SnO ₂ / Sb (mass ratio 9/1, average particle size 0.18 μm) Amount to become 200 mg / m ² Butyl acrylate (30% by mass), styrene (20% by mass) ), Glycidyl acrylate (40% by mass), copolymer latex solution (solid content 30%) 270 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g Finished to 1 liter with water.

(Heat Treatment of Support) In the undercoat drying step of the 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, the temperature was adjusted to 35 ° C and the pH to 3.0. , Silver nitrate 74
g of an aqueous solution containing 370 ml of sodium chloride, potassium bromide, potassium iodide and [Ir (NO) Cl ₅ ] salt in a molar ratio of (60/38/2) at 1 × 10 ⁻⁶ per mol of silver.
370 ml of an aqueous solution containing 1.times.10.sup.- ⁶ mol of rhodium chloride per mol of silver was added by a controlled double jet method while maintaining the pAg at 7.7. Thereafter, 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, the pH was adjusted to 8.0 with NaOH, and pA
g was adjusted to 6.5 to perform reduction sensitization to obtain a cubic silver halide emulsion having an average grain size of 0.06 μm, a monodispersity of 10%, a variation coefficient of projected diameter area of 8%, and a [100] plane ratio of 87%. Obtained. This halide emulsion was subjected to coagulation sedimentation using a gelatin coagulant and desalted to obtain a silver halide emulsion A.

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

[Preparation of Preform Emulsion of Silver Behenate and Silver Halide Emulsion A] 1.51 g of the above silver halide emulsion A was added to the above sodium behenate solution, and the pH was adjusted to 8.1 with a sodium hydroxide solution. Thereafter, 147 ml of a 1 mol / L silver nitrate solution was added over 7 minutes, the mixture was further stirred for 20 minutes, and ultrafiltration was performed to remove water-soluble salts. Silver behenate prepared as described above has an average grain size of 0.8 μm,
The particles had a monodispersity of 8%. After the floc of the above dispersion was formed, water was removed, water was further washed six times and water was removed, followed by drying to prepare a preform emulsion of silver behenate and silver halide emulsion A.

[Preparation of Photosensitive Emulsion] A polyvinyl butyral (average molecular weight: 30
00) in methyl ethyl ketone (17% by mass) 544
g and 107 g of toluene were gradually added and mixed.
Dispersion was performed at 30 ° C. for 10 minutes at 27.5 MPa with a media disperser using a bead mill of 0.5 mm size ZrO ₂ to prepare a photosensitive emulsion.

(Preparation of heat-developable recording material) The following layers were simultaneously coated on both sides of the undercoated support to prepare Sample 1 as a heat-developable recording material.

[Coating on Back Side] A coating solution of a dye-containing layer having the following composition was applied onto the undercoat layer B-1 of the support so as to have a dry mass of 4.2 g / m ² .
Dry at 55 ° C. for 30 minutes.

<Dye-containing layer coating solution> 2-butanone 40 g Cellulose acetate butyrate (Eastman Chemical Company, CAB381-20) 1.7 g Cellulose acetate propylate (Eastman Chemical Company, CAB553-0.4) 1.7 g Polyhydroxystyrene (Maruzen Petrochemical Co., Ltd., Marukalinker PHMC) 0.3 g Dye D-1 32 mg Polyester resin (Bostic, Vitel PE2200B) 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 [Recording layer surface side coating] Undercoat layer A-1 of the support prepared above
A recording layer coating solution and a surface protection layer coating solution having the following compositions were simultaneously coated on the top so that the surface protection layer was the uppermost layer, to prepare Sample 1 as a heat-developable recording material. The coating solution for the recording layer was applied so that the applied silver amount was 2.4 g / m ^2, and drying was performed at 60 ° C. for 15 minutes.

<Coating solution for recording layer> Photosensitive emulsion 240 g Sensitizing dye 1 (0.1% methanol solution) 1.7 ml Halogen compound 1 (6% methanol solution) 3 ml Calcium bromide (0.1% methanol solution) 1 0.7 ml 2-4-chlorobenzoylbenzoic acid (12% methanol solution) 9.2 ml 2-mercaptobenzimidazole (1% methanol solution) 11 ml tribromomethylsulfoquinoline (5% methanol solution) 17 ml Dye: Exemplified compound D-8 (0.5% methanol solution) 1 ml Phthalazine 0.6 g Hardening agent: Exemplified compound V302 0.1 g Antifoggant: Exemplified compound S-3 0.01 g 4-Methylphthalic acid 0.25 g Tetrachlorophthalic acid 0.2 g Benzo Acid derivative 1 0.2 g Reducing agent: Exemplified compound A-4 (20% methanol solution) 29.5 ml Isocyanate compound (Desmodur N3300, manufactured by Mobay, Inc.) 0.5 g <Coating solution for surface protective layer> Acetone 5 ml Methyl ethyl ketone 21 ml Cellulose acetate butyrate (Eastman Chemical Company, 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 monodispersed 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 10mg

[0139]

Embedded image

Next, in the above-mentioned heat-developable recording material sample 1 according to the present invention, the same procedure was carried out except that the type of the high contrast agent and the antifoggant in the recording layer and the amount added were changed to those shown in Table 1. Then, Samples 2 to 9, which are the heat development recording materials according to the present invention, were produced. Furthermore, heat-developable recording materials 10 to 14 as comparative samples were prepared by changing or excluding the comparative high contrast agent or antifoggant in the recording layer.

[0141]

[Table 1]

The details of the compounds shown in Table 1 are as follows. Antifoggant Z-1: Cis-1,2-cyclohexanedicarboxylic anhydride Antifoggant Z-2: Trans-1,2-cyclohexanedicarboxylic anhydride Antifoggant Z-3: 1,2,3,6 -Tetrahydrophthalic anhydride

[0143]

Embedded image

[0144]

Embedded image

<< Evaluation of heat-developable recording material >> (Exposure and heat-development treatment) Each of the heat-developable recording materials prepared above was cut into a size of 5 cm × 15 cm, and then cut at 23 ° C. and 5 ° C.
After humidifying under an atmosphere of 0% RH for 12 hours, each sample was laminated 10 by 10 so that the front and back sides were overlapped, and then placed in an oxygen and moisture impermeable light-shielding barrier bag.
It sealed and heated at 40 degreeC for 3 days, and performed the seasoning process. Next, each sample was exposed using a Dolev 2dry manufactured by Cytex, which is an image setter equipped with a 780 nm semiconductor laser. The exposure pattern was a step exposure in which the exposure energy was changed by 0.1 LogE at a time, and the exposure was performed until the maximum density (Dmax) of each sample after the heat development treatment was saturated. The heat development was performed at 120 ° C. for 25 seconds.

(Measurement and Evaluation of Each Performance) The silver image density of each heat-developed sample obtained as described above was measured with a transmission optical densitometer (PDA-65 manufactured by Konica), and the vertical axis density D- A characteristic curve composed of the horizontal axis exposure amount LogE was prepared. From the characteristic curve, the minimum density (Dmi
n), the maximum density (Dmax) of the exposed portion was determined. Further, the exposure energy amount required to obtain 3.0 as the transmission density was defined as the sensitivity, and the sensitivity was obtained as a relative value with the sensitivity in Sample 1 being 100. The numerical value of the relative sensitivity indicates that the smaller the relative sensitivity, the higher the sensitivity.

Table 1 shows the results obtained as described above. In the table, the relative sensitivity value of Sample 14 could not be calculated because the maximum concentration did not reach 3.0.

As is clear from Table 1, the sample according to the constitution of the present invention shows that the generation of fogging is suppressed, the sample has a sufficient maximum density, and the sample has high sensitivity as compared with the comparative sample. As a result, when the sample of the present invention is subjected to printing plate making, printing time loss is less likely to occur, and fogging is less likely to occur in the non-image area (unexposed area). Can be realized.

[0149]

According to the present invention, a heat-developable recording material for plate-making printing having a high gradation, low fog and high sensitivity can be provided.

Claims (4)

[Claims] 1. A non-photosensitive organic silver salt and a photosensitive
Thermal development having a recording layer containing silver logenide and a reducing agent
In the recording material, the recording layer or a few adjacent to the recording layer
At least one layer is made of a hard material represented by the general formula (1) or (2).
Thermal development characterized by containing a conditioning agent and an acid anhydride
Recording material. Embedded image[Wherein, R₁₁, R₁₂Any one of a hydroxy group,
Alkyloxy group, aryloxy group, heterocyclic oxy
Group, -OM, -SM, -SH, -SR₁₃, -NH _Two, −
NHR₁₄, -NR_FifteenR₁₆Represents a substituent selected from
The other represents a hydrogen atom. M is a metal atom, R₁₃~
R₁₆Each represents a monovalent substituent;_FifteenAnd R₁₆Is concatenated
To form a ring. L₁₁Is-(C = O)-
Or-(SO_Two)-, L₁₂Form a five-membered ring
Represents a necessary linking group. [Chemical formula 2][Wherein, R_{twenty one}Represents a monovalent substituent, and R_{twenty two}Is a hydrogen atom,
Alkyl group, cycloalkyl group, heterocyclic group, alkenyl
And a substituted alkenyl group. n21, n22
Represents an integer of 0 or 1, respectively. ] 2. A non-photosensitive organic silver salt and a photosensitive
Thermal development having a recording layer containing silver logenide and a reducing agent
In the recording material, the recording layer or a few adjacent to the recording layer
At least one layer has a small number selected from the general formulas (3) to (6).
It is characterized by containing at least one contrast agent and an acid anhydride.
Thermal development recording material. Embedded image[Wherein, R₃₁, R₃₂Any one of a hydroxy group,
Alkyloxy group, aryloxy group, heterocyclic oxy
A substituent selected from the group -OM, and the other is hydrogen
Represents an atom or an alkyl group. M is an alkali metal
Represents R₃₃~ R ₃₆Is a hydrogen atom or a monovalent
Represents a substituent. Also, R₃₃~ R₃₆Are adjacent permutations
It may combine with a group to form a ring. L₃₁Is-(C = O)
-Or-(SO_Two)-, L₃₂Is -O-, -S
-, -NR₃₇-Or -CR₃₈R_{Three 9}Represents-. In addition,
R₃₇~ R₃₉Represents a hydrogen atom, an alkyl group,
Represents a kill group or an aryl group. [Formula 4][Wherein, R₄₁, R₄₂Any one of a hydroxy group,
Alkyloxy group, aryloxy group, heterocyclic oxy
Represents a substituent selected from the group and —OM, and the other is hydrogen
Represents an atom or an alkyl group. M is an alkali metal
Represents R₄₃~ R ₄₆Is a hydrogen atom or monovalent substitution
Represents a group. Also, R₄₃~ R₄₆Is an adjacent substituent
And may form a ring. L₄₁Is-(C = O)
-Or-(SO_Two)-, L₄₂Is -O-, -S
-, -NR₄₇-Or -CR₄₈R₄₉Represents-. In addition,
R₄₇~ R₄₉Represents a hydrogen atom, an alkyl group,
Represents a kill group or an aryl group. [Chemical formula 5][Wherein, R₅₁Represents a monovalent substituent. [Formula 6][Wherein, R₆₁Represents an alkyl group or a substituted alkyl group;
₆₂Represents an alkenyl group, a substituted alkenyl group, or a heterocyclic group.
You. ] 3. A heat-developable recording material having a recording layer containing a non-photosensitive organic silver salt, a photosensitive silver halide and a reducing agent on a support, wherein at least one recording layer or at least one layer adjacent to the recording layer comprises: A heat-developable recording material comprising the high-contrast agent represented by the general formula (1) or (2) and a sulfonium salt compound. 4. A heat-developable recording material having a recording layer containing a non-photosensitive organic silver salt, a photosensitive silver halide and a reducing agent on a support, wherein at least one of the recording layer or at least one layer adjacent to the recording layer comprises: A heat-developable recording material characterized by containing at least one type of toning agent selected from formulas (3) to (6) and a sulfonium salt compound.