JP2002328446A - Heat developable recording material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable recording material having high sensitivity and high image quality and free of the deterioration of performance in a hot atmosphere. SOLUTION: In the heat developable recording material having a recording layer containing an organic silver salt, photosensitive silver halide and a thermally working reducing agent on one face of a transparent base and having a dye-containing layer on the opposite face, a compound of formula (1) is contained in at least one layer on the face with the dye-containing layer.

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 having improved performance under a high-temperature atmosphere.

[0002]

2. Description of the Related Art A heat-developable, silver-salt heat-developable recording material (hereinafter also referred to as a "photosensitive material") is a wet-developing process using a developing solution or a fixing solution which has been required for a conventionally known silver salt photographic material. Since no process is required, not only is treatment liquid piping equipment and waste liquid treatment equipment unnecessary, but no waste liquid is generated.
Since it does not require the trouble of replacing and replenishing the processing solution, there is no risk of injury to the operator due to the trouble, and there is no concern that the performance will fluctuate due to the use of the processing solution over time.

However, the thermal recording material is an organic silver salt,
Due to the fact that the composition contains photosensitive silver halide and a heat-reducing reducing agent in the photosensitive material, and the development reaction is promoted by thermal energy, there is a concern that performance may deteriorate in high-temperature atmospheres in principle. Have been.

Further, when a heat-developed recording material is used as a printing original for printing on a printing plate, it is required to have a high contrast in order to enhance the reproducibility of a halftone photographic original. By adopting a compound capable of functioning as a high contrast agent, a high-contrast photosensitive material can be obtained, but the deterioration in performance under a high-temperature atmosphere is further increased, and thus an improvement has been desired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat-developable recording material that does not deteriorate in high-temperature atmosphere. Another object of the present invention is to provide a high-sensitivity, high-quality heat-developable recording material suitable for a printing original on a printing plate.

[0006]

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

1) On one side of a transparent support, there is provided a recording layer containing an organic silver salt, a photosensitive silver halide and a heat-reducing agent, and on a surface opposite to the surface having the recording layer. A heat-developable recording material having a dye-containing layer, wherein at least one of the surfaces having the dye-containing layer contains the compound of the formula (1).

2) The heat-developable recording material as described in 1) above, wherein the layer containing the compound of the formula (1) is the outermost layer on the side opposite to the side having the recording layer.

3) On one side of the transparent support, there is provided a recording layer containing an organic silver salt, a photosensitive silver halide, and a heat-reducing agent, and on a surface opposite to the surface having the recording layer. A heat-developable recording material having a dye-containing layer, wherein at least one surface having the dye-containing layer contains a secondary or tertiary amino compound having a molecular weight of 150 or more.

(4) The heat-developable recording material as described in (3) above, wherein the layer containing a secondary or tertiary amino compound having a molecular weight of 150 or more is the outermost layer on the side opposite to the side having the recording layer.

(5) The heat-developable recording material as described in (3) or (4) above, wherein the secondary or tertiary amino compound having a molecular weight of 150 or more is a compound having a plurality of amino groups in one molecule.

6) The heat-developable recording material as described in 5) above, wherein the secondary or tertiary amino compound having a plurality of amino groups in one molecule and having a molecular weight of 150 or more is polyethyleneimine.

(7) The heat-developable recording as described in any one of (1) to (6) above, wherein the recording layer and / or the layer adjacent to the recording layer contains the compound of the general formula (2). material.

8) The heat-developable recording as described in any one of 1) to 6) above, wherein the recording layer and / or the layer adjacent to the recording layer contains the compound of the general formula (3). material.

9) The heat-developable recording as described in any one of 1) to 6) above, wherein the recording layer and / or a layer adjacent to the recording layer contains the compound of the general formula (4). material.

Hereinafter, the present invention will be described in detail. In the general formula (1), the groups represented by R ₁ and R ₂ represent a hydrogen atom, an acyl group, a hydrocarbon group, and a carbamoyl group, and the hydrocarbon groups include an alkyl group (including an aralkyl group);
Aryl groups are preferred. Examples of the groups represented by R ₁ and R ₂ include a hydrogen atom, a substituted or unsubstituted acyl group having 1 to 10 carbon atoms (eg, acetyl, propionyl),
10 substituted or unsubstituted alkyl groups (eg, methyl, ethyl, propyl, benzyl, hydroxyethyl), substituted or unsubstituted aryl groups having 6 to 10 carbon atoms (eg, phenyl, 4-ethoxyphenyl, naphthyl), Or a substituted or unsubstituted carbamoyl group (eg, carbamoyl, N, N-dimethylcarbamoyl)
Are preferable, and a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a carbamoyl group is particularly preferable. Alternatively, R ₁ and R ₂ may be a hydrocarbon group, and the hydrocarbon may have a derivative of a cyclic compound represented by the general formula (1).

X represents an oxygen atom or an imino group (＝ NH). When X is an oxygen atom, at least one of R ₁ and R ₂ is a hydrogen atom.

The divalent group represented by L ₁ is a group of non-metallic atoms necessary for forming a nitrogen-containing polycyclic structure, and may have a ring structure inside L _1. And a condensed ring may be formed together with the following structural formula in the general formula (1).

[0019]

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As L ₁ , for example, ethylene, trimethylene or a compound having the following structure is preferable.

[0021]

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In the above examples of L ₁ , L ₁ may be substituted by a methyl group, an amino group, a ureido group, a methylene group (＝ CH ₂ ) or the like.

Examples of the cyclic compound represented by the general formula (1) used in the present invention are shown below, but the present invention is not limited thereto.

[0024]

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[0025]

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These cyclic compounds are known in the art as an inhibitor of photographic performance deterioration due to formaldehyde gas. Such a compound has, on one side on a transparent support, a recording layer containing an organic silver salt, a photosensitive silver halide, and a thermoactive reducing agent, and a surface opposite to the surface having the recording layer. In a heat-developable recording material having a dye-containing layer, a remarkable effect of preventing performance deterioration such as fogging and sensitivity fluctuation in a high-temperature atmosphere is exhibited by being contained in at least one of the surfaces having the dye-containing layer. That was very interesting and hard to predict.

Further, in particular, the general formulas (2), (3),
Although the compound of (4) can function as a high contrast agent, it is very interesting and difficult to predict that the compound exhibited a greater effect in the heat-developable recording material contained in the recording layer and / or the layer adjacent to the recording layer. Was that. Specific examples of this series of compounds are described in JP-A-61-73150 and JP-A-61-73150.
It is included in the compound group described in 8-10738, 50-87028, etc. In addition, these compounds are commercially available and, for example, British Patent No. 717,287.
Nos. 2,731,472 and 3,187, U.S. Pat.
No. 004, JP-A-58-79248 and the like. Further, two or more of these compounds may be used in combination.

These cyclic compounds used in the present invention are:
The heat-developable recording material can be used by being contained in at least one surface having a dye-containing layer provided on the surface opposite to the surface having the recording layer. More preferably, it can be used by being contained in the uppermost layer of the surface having the dye-containing layer.
In order to add the cyclic compound used in the present invention to these layers, the compound can be added as it is in a coating solution or dissolved in a solvent such as alcohol or methyl ethyl ketone. The addition amount of this cyclic compound is suitably from 0.001 to 1 g per m ^{2 of the} heat-developable recording material.
0.005 to 0.5 g is more preferred.

The heat-developable recording material of the present invention has, on one side on a transparent support, a recording layer containing an organic silver salt, a photosensitive silver halide and a heat-reducing reducing agent. And a secondary or tertiary amino compound having a molecular weight of 150 or more (hereinafter, referred to as an amino compound of the present invention) on at least one surface having the dye-containing layer. Can be contained.

The structure of the amino compound of the present invention is arbitrary, but it is preferable that at least two of the substituents bonded to the nitrogen atom are an alkyl group or a substituted alkyl group. Examples include dialkylamines, trialkylamines and compounds having any substituents on the alkyl groups of these amines.

Specific examples include alkylamines such as tributylamine, triamylamine, trihexylamine, triheptylamine, trioctylamine, diamylamine, dihexylamine, diheptylamine, dioctylamine, butylhexylamine and diethylhexylamine. And the like. As the alkylamines,
It also contains an amino compound having a branched alkyl group such as di (2-ethylhexyl) amine. In addition, compounds having any substituents such as an aryl group, a substituted aryl hydroxyl group, a heterocyclic group, a hydroxyl group, an amino group, an acyl group, a halogen atom, a nitro group, and an alkoxy group as an alkyl group of these amino compounds are exemplified. .

Further, as the amino compound of the present invention, a compound having a plurality of amino groups in one molecule can also be preferably used. Examples include alkyl-substituted diamines such as ethylenediamine, propylenediamine, and phenylenediamine. As a specific example, N,
N'-dialkylethylenediamines, N, N, N ',
N "-tetraalkylethylenediamine, N, N'-
Dialkyl propylene diamines, N, N, N ', N "
-Tetraalkylpropylenediamines, N, N'-dialkylpiperazines, or an alkyl group of these amines, which has an aryl group, a heterocyclic group, a hydroxyl group, an amino group,
Compounds having an arbitrary substituent such as an acyl group, a halogen atom, a nitro group, and an alkoxy group are exemplified.

The amino compound of the present invention may be a polymer compound. Preferred high molecular weight amino compounds of the present invention include high molecular weight compounds such as polyethyleneimine, chitin and chitosan, and copolymers using amino group-containing vinyl monomers such as dimethylaminoethyl methacrylate. Among them, polyethyleneimine is particularly preferred. However, the amino compound of the present invention is not limited by the above specific examples. Amino compounds having a molecular weight of less than 150 are not preferred in terms of odor, because the heat-developable recording material is transferred to the recording layer when further rolled up.

The amino compound of the present invention can be used by being contained in at least one of the surfaces having a dye-containing layer provided on the surface opposite to the surface having the recording layer of the heat-developable recording material. More preferably, it can be used by being contained in the uppermost layer of the surface having the dye-containing layer. In order to add the amino compound of the present invention to these layers, the compound can be added as it is in a coating solution or dissolved in a solvent such as alcohol or methyl ethyl ketone. The addition amount of the amino compound of the present invention is 1 m ² of the heat-developable recording material.
0.001 to 1 g is appropriate, and 0.005 to 0.5 g
More preferred. In addition, two or more amino compounds of the present invention may be used in combination, or may be used in combination with the compound of the general formula (1).

The compound of the general formula (2) functions as a high contrast agent when it is contained in one or both of the recording layer and the layer adjacent to the recording layer. General formula (2)
Preferred examples of the compound include the following.

[0036]

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The preferable addition amount of the compound of the formula (2) is 0.0 to 1 mol of silver atom contained in the recording layer.
The range is from 01 to 0.3 mol. A more preferred addition amount is in the range of 0.005 to 0.1 mol.

The compound of the general formula (3) functions as a high contrast agent when it is contained in one or both of the recording layer and the layer adjacent to the recording layer. General formula (3)
Preferred compound groups include the following.

[0039]

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The preferable addition amount of the compound of the formula (3) is 0.0 to 1 mol of silver atom contained in the recording layer.
The range is from 01 to 0.3 mol. A more preferred addition amount is in the range of 0.005 to 0.05 mol.

The compound of the general formula (4) functions as a high contrast agent when it is contained in one or both of the recording layer and the layer adjacent to the recording layer. General formula (4)
Preferred examples of the compound include the following.

[0042]

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A preferable addition amount of the compound of the general formula (4) is 0.0 to 1 mol of silver atom contained in the recording layer.
The range is from 01 to 0.3 mol. A more preferred addition amount is in the range of 0.005 to 0.05 mol.

In the present invention, the organic silver salt is a reducible silver source, and a silver salt of an organic acid or a heteroorganic acid containing a reducible silver ion source, especially a long chain (10 to 30, preferably 15 to 30). Aliphatic carboxylic acids having up to 25 carbon atoms) and nitrogen-containing heterocycles 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 Research
h Disclosure (hereinafter referred to as RD) No. 17
029 and 29996, and include the following.

Salts of organic acids (eg, salts of gallic acid, oxalic acid, behenic acid, arachidic acid, stearic acid, palmitic acid, lauric acid, etc.); silver carboxyalkylthiourea salts (eg, 1- (3-carboxy) Propyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc.); silver complexes of polymer reaction products of aldehydes with hydroxy-substituted aromatic carboxylic acids (for example, 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 thiones (eg, 3- (2-carboxy) Ethyl) -4
-Hydroxymethyl-4-thiazoline-2-thione, 3
-Carboxymethyl-4-thiazoline-2-thione),
Imidazole, pyrazole, urazole, 1,2,4-
Thiazole and 1H-tetrazole, 3-amino-5
A complex or salt of silver with a nitrogen acid selected from benzylthio-1,2,4-triazole and benzotriazole;
Silver salts such as saccharin and 5-chlorosalicylaldoxime; silver salts of mercaptides. Of these, preferred silver sources are silver behenate, arachidic acid and / or stearic acid.

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 normal mixing method, a reverse mixing method, a simultaneous mixing method, and a method described in JP-A-9-12764.
A controlled double jet method as described in No. 3 is preferably used. For example, an organic acid alkali metal salt soap (eg, sodium hydroxide, potassium hydroxide, etc.)
Sodium behenate, sodium arachidate, etc.)
The soap and silver nitrate are added to produce organic silver salt crystals. At that time, silver halide grains may be mixed.

In the present invention, the organic silver salt has an average particle size of 2 μm.
m or less, and is preferably monodisperse. Here, the monodispersion means that the degree of dispersion obtained by the following equation is 50%.
Refers to the following. The particle size is more preferably 40% or less, and particularly preferably 0.1% or more and 35% or less.

The degree of dispersion (%) = (standard deviation of particle size) / (average value of particle size) × 100 The average particle size of the organic silver salt means that the particles of the organic silver salt are, for example, spherical, rod-shaped, or tabular. In the case of the particles of the above, the diameter refers to the diameter of a sphere equivalent to the volume of the organic silver salt particles. The average particle size is preferably 0.05 to 1.5 μm, particularly 0.05 to 1.5 μm.
1.0 μm is preferred. Further, in the organic silver salt of the present invention, it is preferable that 60% or more of the total organic silver salt is tabular grains. In the present invention, the tabular grains refer to the ratio of the average grain size to the thickness, that is, the aspect ratio (AR
Abbreviation) means three or more.

AR = average particle size (μm) / thickness (μm) In order to form the organic silver salt into these shapes, the organic silver salt crystal is dispersed and pulverized together with a binder, a surfactant and the like by a ball mill or the like. Obtained by: Within this range, a photosensitive material having a high density and excellent image storability can be obtained.

As a method for producing the photosensitive silver halide grains of the present invention, a solution or dispersion of an organic silver salt prepared in advance or a sheet material containing an organic silver salt is reacted with a silver halide forming component. It is preferable to convert a part of the organic silver salt into photosensitive silver halide. The silver halide thus formed is in effective contact with the organic silver salt and exhibits a preferable action. A silver halide-forming component is a compound capable of forming a photosensitive silver halide by reacting with an organic silver salt, and which compound is applicable and effective is determined by the following simple test. Can do things. That is, the organic silver salt is mixed with the compound to be tested,
If necessary, after heating, it is examined by an X-ray diffraction method whether there is a peak specific to silver halide. Silver halide-forming components confirmed to be effective by such tests include inorganic halides, onium halides, halogenated hydrocarbons, N-halogen compounds, and other halogen-containing compounds. Are U.S. Pat. Nos. 4,009,039 and 3,457,07.
No. 5,003,749, British Patent No. 1,49
No. 8,956, JP-A-53-27027, and JP-A-53-27027.
No. 25420, an example of which is shown below.

(1) Inorganic halide: for example, MX _n
(Where M represents H, NH ₄ and a metal atom, n represents 1 when M is H and NH ₄ , and represents its valency when M is a metal atom. Metal atom as,
Lithium, sodium, potassium, cesium, magnesium, calcium, strontium, barium, zinc,
Cadmium, mercury, tin, antimony, chromium, manganese, iron, cobalt, nickel, rhodium, cerium, etc.). Further, halogen molecules such as bromine water are also effective.

(2) Onium halides: For example, quaternary ammonium halides such as trimethylphenylammonium bromide, cetylethyldimethylammonium bromide and trimethylbenzylammonium bromide, and quaternary phosphoniums such as tetraethylphosphonium bromide There are halides and tertiary sulfonium halides such as trimethylsulfonium iodide.

(3) Halogenated hydrocarbons: for example, iodoform, bromoform, carbon tetrachloride, 2-bromo-2-methylpropane and the like.

(4) N-halogen compound: For example, N-halogen compound
Chlorosuccinimide, N-bromosuccinimide, N-bromophthalimide, N-bromoacetamide, N-iodosuccinimide, N-bromophthalazone, N-bromooxazolinone, N-chlorophthalazone, N-bromoacetanilide, N , N-dibromobenzenesulfonamide, N-bromo-N-methylbenzenesulfonamide,
1,3-dibromo-4,4-dimethylhydantoin, N
-Bromourazole and the like.

(5) Other halogen-containing compounds: for example, triphenylmethyl chloride, triphenylmethyl bromide, 2-bromoacetic acid, 2-bromoethanol, dichlorobenzophenone and the like.

In order to prepare silver halide grains having a grain size of 0.01 to 0.1 μm, in addition to the organic silver grains, any method known in the field of photography, such as a single jet or double jet method, may be used. Thus, silver halide grains can be prepared by any method such as, for example, an ammonia method emulsion, a neutral method, and an acid method. Prepared in this way in advance,
Then, it can be mixed with other components of the present invention and introduced into the composition used in the present invention. In this case, in order to sufficiently bring the photosensitive silver halide into contact with the organic silver salt, for example, US Pat. Nos. 3,706,564 and 3,706, as protective polymers for preparing photosensitive silver halide. 5
Nos. 65, 3,713,833 and 3,748,14
No. 3, British Patent No. 1,362,970, which uses a polymer other than gelatin such as polyvinyl acetal, or a photosensitive halogenation method described in British Patent No. 1,354,186. Means for enzymatic degradation of silver emulsion gelatin or US Pat. No. 4,076,539
By preparing photosensitive silver halide grains in the presence of a surfactant as described in the above-mentioned publication, various means such as a means for omitting the use of a protective polymer can be applied. Silver halide grains having a grain size of 0.01 to 0.1 μm preferably have photosensitivity and function as an optical sensor. The shape of the silver halide is not particularly limited, and may be cubic, octahedral, so-called normal crystals, or non-normal crystals, such as spherical, rod-shaped, or tabular grains. There is no particular limitation on the silver halide composition, and silver chloride, silver chlorobromide,
Any of silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide may be used.

The amount of silver halide grains having a grain size of less than 0.01 μm is preferably contained in an amount of 1% or more based on the total silver halide grains, and more preferably 5% or more and 70% or less. Particularly preferred are silver halide grains having a size of less than 01 μm.

The photosensitive silver halide used in the present invention may also contain a halogen component such as a halide ion when preparing an organic silver salt, as described in British Patent 1,447,454. By coexisting with an organic silver salt-forming component and injecting silver ions into the organic silver salt-forming component, it can be produced almost simultaneously with the production of the organic silver salt.

These silver halide forming components are used in a small amount stoichiometrically with respect to the organic silver salt. Usually, the range is 0.001 to 0.7 mol, preferably 0.03 to 0.5 mol, per 1 mol of the organic silver salt. Two or more silver halide forming components may be used in combination within the above range. Various conditions such as reaction temperature, reaction time, reaction pressure and the like in the step of converting a part of the organic silver salt into silver halide using the above-mentioned silver halide forming component can be appropriately set according to the purpose of production. However, usually, the reaction temperature is 20 to 70 ° C,
The reaction time is 0.1 second to 72 hours, and the reaction pressure is preferably set to the atmospheric pressure. This reaction also
It is preferably carried out in the presence of a polymer used as a binder described below. The amount of polymer used at this time is
The amount is 0.01 to 100 parts by mass, preferably 0.1 to 10 parts by mass per 1 part by mass of the organic silver salt.

The photosensitive silver halide prepared by the various methods described above includes, for example, sulfur-containing compounds, gold compounds,
Platinum compounds, palladium compounds, silver compounds, tin compounds,
Chemical sensitization can be achieved by a chromium compound or a combination thereof. The method and procedure of the chemical sensitization are described in, for example, US Pat. No. 4,036,650, British Patent 1,518,850, JP-A-51-22430,
Nos. 51-78319 and 51-81124. Also, when a part of the organic silver salt is converted to a photosensitive silver halide by a silver halide forming component, as described in U.S. Pat. An amide compound having a molecular weight may coexist.

In addition, these photosensitive silver halides may be used in order to prevent illuminance failure or to adjust the gradation.
Metals belonging to group III, such as Rh, Ru, Re, Ir, O
It is preferable to contain ions such as s and Fe, complexes thereof and complex ions. In particular, it is preferable to add as a complex ion. For example, it is preferable to add an Ir complex ion such as [IrCl ₆ ] ²⁻ because of illuminance failure.

The photosensitive silver halide grains in the present invention may be chemically sensitized. Preferred chemical sensitization methods include
As is well known in the art, a sulfur sensitization method, a selenium sensitization method, a tellurium sensitization method, a noble metal sensitization method such as a gold compound, platinum, palladium, and iridium compound and a reduction sensitization method can be used. . As the compound preferably used in the sulfur sensitization method, the selenium sensitization method, and the tellurium sensitization method, known compounds can be used, and the compounds described in JP-A-7-128768 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. 618,061. The compounds described in, for example, can be preferably used. Specific compounds for the reduction sensitization method include, in addition to ascorbic acid and thiourea dioxide, for example, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds, polyamine compounds, and the like. it can. Further, reduction sensitization can be achieved by ripening the emulsion while maintaining the pH of the emulsion at 7 or more or the pAg at 8.3 or less. Further, reduction sensitization can be achieved by introducing a single addition portion of silver ions during grain formation.

The heat-developable recording material of the present invention has a built-in heat-reducing agent. Examples of suitable thermally acting reducing agents are described in U.S. Patent Nos. 3,770,448 and 3,773,512.
No. 3,593,863 and RD17029 and 2
9963, and the following may be mentioned.

Aminohydroxycycloalkenones (eg, 2-hydroxypiperidino-2-cyclohexenone); aminoreductones esters (eg, piperidinohexose reductone monoacetate) as precursors of reducing agents An N-hydroxyurea derivative (for example, Np-methylphenyl-N
Hydrazones of aldehydes or ketones (e.g. anthracene aldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (e.g.
Hydroquinone, t-butyl-hydroquinone, isopropylhydroquinone and (2,5-dihydroxy-phenyl) methylsulfone); sulfhydroxamic acids (eg, benzenesulfhydroxamic acid); sulfonamidoanilines (eg, 4- (N- Methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (eg, 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone); tetrahydroquinoxalines (eg, 1,2,3,4-tetrahydro) Amide oximes; 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 Combinations of azines and sulfonamidophenols; α-cyanophenylacetic acid derivatives; combinations of bis-β-naphthol and 1,3-dihydroxybenzene derivatives; 5-pyrazolones; sulfonamidophenol reducing agents; 2-phenylindane-1 ,
3-dione and the like; chroman; 1,4-dihydropyridines (eg, 2,6-dimethoxy-3,5-dicarbethoxy-1,4-dihydropyridine); bisphenols (eg, bis (2-hydroxy-3- t-butyl-5
-Methylphenyl) methane, bis (6-hydroxy-m
-Tri) mesitol, 2,2-bis (4-hydroxy-3-methylphenyl) propane,
4,5-ethylidene-bis (2-t-butyl-6-methyl) phenol), ultraviolet-sensitive ascorbic acid derivatives and 3-pyrazolidones. Among them, particularly preferred reducing agents are hindered phenols. Examples of the hindered phenols include compounds represented by the following general formula (A).

[0065]

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In the formula, R is a hydrogen atom or a group having 1 to 1 carbon atoms.
10 alkyl group (e.g., -C ₄ H _9, 2,4,4-trimethyl pentyl) represents, R 'and R "is an alkyl group having 1 to 5 carbon atoms (e.g., methyl, ethyl, t- butyl ).

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

[0068]

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

In the heat-developable recording material of the present invention, it is desirable to use an additive called a color tone agent, a color tone imparting agent or an activator toner (hereinafter, referred to as a color tone agent) together with the above-mentioned components. The color tone agent participates in the oxidation-reduction reaction between the organic silver salt and the reducing agent, and has a function of making the resulting silver image dark, particularly black. An example of a suitable toning agent is RD1702
No. 9, and preferred toning agents include phthalazone or phthalazine.

The heat-developable recording 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, 4,740,455, 4,741,966, 4,751,175, and 4,835. No. 096 can be used. Useful sensitizing dyes are described, for example, in RD17643 IV-A (p.23, December 1978), Item 1831X.
(August 1978, p. 437). 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
And compounds described in JP-A Nos. 9-54409 and 9-80679 are preferably used.

In the case of supersensitization, the photosensitivity becomes particularly high. If the reducing agent is not deactivated, the printout silver after development tends to be large, which is particularly effective in the present invention. In the case of infrared sensitization, the infrared sensitizing dye further has a redox potential capable of reducing silver halide and organic silver salt to some extent. In the presence of a reducing agent that can reduce the organic silver salt, silver clusters that become fogged silver are easily formed. The generated silver clusters also act as catalyst nuclei and induce fog, so that when stored in a dark place, the storage stability decreases,
Further, when exposed to a light place after development, a phenomenon such as an increase in printout silver occurs. Further, the sensitivity of the infrared-sensitive material extends to a heat radiation region outside the range of visible light, so that it is effective in increasing printout silver by heat radiation even in a dark place. In particular, in the case of a heat-developing recording material which has been enhanced in sensitivity by a supersensitizer and which has been subjected to infrared spectral sensitization, the effect is large.

These sensitizing dyes may be used alone or in combination, and the combination of sensitizing dyes is often used particularly for supersensitization. Along with 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. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization, and substances exhibiting supersensitization are described in RD17643 (issued December 1978) No. 2
Section J on page 3, IV, or Japanese Patent Publication No. 9-25500, 4
3-4933, JP-A-59-19032, and JP-A-59-19032.
192,242 and JP-A-5-341432.

As the supersensitizer, a heteroaromatic mercapto compound represented by the following general formula is preferable.

General Formula Ar-SM In the formula, M is a hydrogen atom or an alkali metal atom;
r is a heteroaromatic ring having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably,
Benzimidazole, naphthymidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotetrazole, imidazole, oxazole, pyrazole, triazole, triazine, pyrimidine, pyridazine, pyrazine, pyridine, pudding, quinoline or quinazoline .

It should be noted that a disulfide compound which substantially forms the above-mentioned mercapto compound when contained in a dispersion of an organic silver salt and / or a photosensitive silver halide grain emulsion is also included. In particular, a disulfide compound represented by the following general formula can be mentioned as a preferred example.

Ar in the general formula Ar-SS-Ar has the same meaning as in Ar-SM.

The above heteroaromatic ring includes, for example, a halogen atom (eg, Cl, Br, I), a hydroxyl group, an amino group, a carboxyl group, an alkyl group (eg, one or more carbon atoms, preferably 1 to 4 carbon atoms). And alkoxy groups (e.g., one or more carbon atoms,
(Preferably having 1 to 4 carbon atoms).

The supersensitizer is contained in an emulsion layer containing an organic silver salt and silver halide grains in an amount of 0.001 to 1.
It is preferable to use it in the range of 0 mol. Particularly preferably,
An amount in the range of 0.01 to 0.5 mole per silver mole is preferred.

The heat-developable recording material of the present invention may contain an antifoggant. As effective antifoggants, mercury compounds known from, for example, U.S. Pat. No. 3,589,903 are environmentally undesirable. For this reason, non-mercury antifoggants have been studied for a long time. Non-mercury antifoggants include, for example, US Pat. No. 4,546,075.
No. 4,452,885 and JP-A-59-572.
No. 34 is preferred.

In the present invention, to further improve the density fluctuation during storage with time, an oxidizing agent for reducing fog after development is used. Preferred examples of such an oxidizing agent include, for example, JP-A-50-119624 and JP-A-50-12.
No. 0328, No. 51-121332, No. 54-580
No. 22, 56-70543, 56-99335
No., 59-90842, 61-129,624,
62-129845, JP-A-6-208191,
No. 7-5621, No. 7-2781, No. 8-1580
9, U.S. Patent Nos. 5,340,712 and 5,36
No. 9,000, No. 5,464,737, No. 3,87
4,946, 4,756,999, 5,34
0,712, European Patent Nos. 605,981A1, 6
Compounds described in JP-A Nos. 22,666A1, 631,176A1, JP-B-54-165, JP-A-7-2781, U.S. Pat. Nos. 4,180,665 and 4,442,202 can be used. Although it can be used, a polyhalogen compound described in JP-A-2000-131795 is preferable.

The oxidizing agent is 10 mg / m^Two~ 3g / m^TwoContained
Preferably, 50 mg / m ^Two~ 1g / m^TwoIs more
preferable. Oxidizing agents include solutions, powders, solid fine particle dispersions, etc.
It may be added by any method.
Preferably, the particles are dispersed. Dispersion aid when dispersing
An agent may be used. In addition, sensitizing dyes, reducing agents,
Any other additive may be added as a mixed solution.

In addition to the above-mentioned oxidizing agents, suitable antifoggants include compounds disclosed in US Pat. Nos. 3,874,946 and 4,756,999; -288328 paragraph number [0030] ~
Compound described in [0036], JP-A-9-90
No. 550, compounds described in paragraph numbers [0062] to [0063], which are disclosed in U.S. Pat. No. 5,028,523 and European Patent Nos. 600,587, 631,176 and 605,981. Are preferably used.

When a polymer latex is used for the recording layer, the recording layer is preferably prepared by applying an aqueous coating solution and then drying. However, the term "aqueous" as used herein means that 50% by mass or more of the solvent (dispersion medium) of the coating liquid is water, and preferably 65% by mass or more of the solvent is water. Components other than water of the coating solution are methyl alcohol, ethyl alcohol, isopropyl alcohol, methyl cellosolve,
Water-miscible organic solvents such as ethyl cellosolve, dimethylformamide, and ethyl acetate can be used. Specific examples of the solvent composition include the following.
Water / methanol = 90/10, water / methanol = 70 /
30, water / ethanol = 90/10, water / isopropanol = 90/10, water / dimethylformamide = 95 /
5. Water / methanol / dimethylformamide = 80/1
5/5, water / methanol / dimethylformamide = 90
/ 5/5 (however, the numbers represent mass%).

A crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added to the recording layer. When the recording layer contains a polymer latex, the thermal recording layer coating liquid is preferably a so-called thixotropic fluid. The thixotropic property refers to a property in which the viscosity decreases as the shear rate increases. Although any apparatus may be used for the viscosity measurement, an RFS fluid spectrometer manufactured by Rheometrics Far East Co., Ltd. is preferably used, and the viscosity is measured at 25 ° C. The organic silver salt-containing fluid or the thermal image forming layer coating solution in the invention has a shear rate of 0.1.
The viscosity in S-1 is 400 mPa · s or more, 100,
000 mPa · s or less, more preferably 5 mPa · s or less.
It is not less than 00 mPa · s and not more than 20,000 mPa · s. At a shear rate of 1000 S-1, 1 mP
It is preferably not less than a · s and not more than 200 mPa · s, and more preferably not less than 5 mPa · s and not more than 80 mPa · s.

Various systems exhibiting thixotropic properties are known, and are described in, for example, "Koza Rheology", edited by Kobunshi Kankokai, "Polymer Latex", co-authored by Muroi and Morino (published by Kobunshi Kankokai). In order for the fluid to exhibit thixotropic properties, it is necessary to contain a large amount of solid fine particles. In order to enhance the thixotropic property, the thickening linear polymer is contained, the aspect ratio is increased by the anisotropic solid fine particles contained, alkali thickening,
Use of a surfactant is effective.

The total amount of binder in the recording layer is 0.2 to 30 g.
/ M ² , more preferably in the range of 1 to 15 g / m ² .

In order to protect the surface of the heat-developable recording material and prevent abrasion, a non-recording layer may be provided outside the recording layer. The binder used for these non-recording layers may be the same or different from the binder used for the recording layer.

In the present invention, a matting agent is preferably contained on the recording layer side, and in order to prevent damage to the image after heat development, it is preferable to provide a matting agent on the surface of the heat-developable recording material. It is preferable that the matting agent is contained in a mass ratio of 0.5 to 30% based on all binders on the recording layer side. When a non-recording layer is provided on the opposite side of the recording layer with the support interposed therebetween, it is preferable that at least one layer on the non-recording layer side contains a matting agent. The shape of the matting agent can be either regular or irregular. However, it is preferably a regular shape, and a spherical shape is preferably used.

In the heat-developable recording material of the present invention, only a recording layer may be formed on a support, but it is preferable to form at least one non-recording layer on the recording layer. In order to control the amount or wavelength distribution of light passing through the recording layer, a filter dye layer 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. May contain a dye or a pigment.

These non-recording layers preferably contain the binder or matting agent described above, and may further contain a slip agent such as a polysiloxane compound, wax or liquid paraffin.

In the heat-developable recording material of the present invention, various surfactants can be used as a coating aid. Among them, a fluorine-based surfactant is preferably used for improving charging characteristics and preventing spot-like coating failure.

In the present invention, the antihalation layer can be provided on the side farther from the light source than the recording layer. The antihalation layer preferably has a maximum absorption in a desired wavelength range of 0.1 or more and 2 or less, more preferably 0.2 or more and absorption of an exposure wavelength of 1.5 or less, and after treatment. 0.00 in the visible region
The layer preferably has an optical density of 1 or more and less than 0.2, more preferably 0.001 or more and less than 0.15.

When antihalation dyes are used in the present invention, these dyes have the desired absorption in the wavelength range, have a sufficiently low absorption in the visible region after treatment, and have the desired absorbance spectrum shape of the antihalation layer. Any compound can be used, if possible.

For example, the following are disclosed, but the present invention is not limited thereto. As a single dye, JP-A-59-56458, JP-A-2-
No. 216140, No. 7-13295, No. 7-1143
No. 2, U.S. Pat. No. 5,380,635;
No. 8539, page 13, lower left column, line 1 to page 14, lower left column, line 9; 3-24539, page 14, lower left column, line 1
The compounds described in the lower right column on page 6 include the dyes which can be decolorized by the treatment, as described in JP-A Nos. 52-139136 and 53-132.
No. 334, No. 56-501480, No. 57-1606
No. 0, 57-68831, 57-101835
No. 59-182436, JP-A-7-36145
No. 7-199409, JP-B-48-33692
No. 50-16648, Tokiko 2-41734,
U.S. Pat. Nos. 4,088,497 and 4,283,48
No. 7, 4,548,896, 5,187,049
No. etc.

The heat-developable recording material of the present invention is preferably a so-called single-sided recording material having at least one recording layer on one side of a support and a back layer on the other side.

In the present invention, suitable binders for the backing layer are transparent or translucent, generally colorless, and natural polymer synthetic resins, 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) s, poly (urethanes), phenoxy resin, poly (vinylidene chloride), poly (epoxide)
, Poly (carbonate) s, poly (vinyl acetate), cellulose esters, and poly (amide) s. The binder may be coated from water or an organic solvent or an emulsion.

The back layer preferably has a maximum absorption in a desired wavelength range of 0.3 or more and 2 or less, more preferably an absorption of 0.5 or more and 2 or less, and a visible region after treatment. Is not less than 0.001 and 0.5
Is preferably less than 0.00, more preferably 0.00
It is preferable that the layer has an optical density of 1 or more and less than 0.3. When used for printing plate making, 400 nm
Is preferably 0.001 or more and less than 0.2, more preferably a layer having an optical density of 0.001 or more and less than 0.15. Examples of the antihalation dye used in the back layer are the same as the antihalation layer described above.

Various additives may be added to any of the recording layer, the non-recording layer, and other forming layers. In the heat-developable recording material of the present invention, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, a coating aid and the like may be used. These additives and the other additives mentioned above,
The compounds described in RD17029 (pp. 9 to 15 in June, 1978) can be preferably used.

As the transparent support of the present invention, a plastic film (for example, a cellulose acetate film, a polyester film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polyamide film, a polyimide film, a cellulose triacetate film or a polycarbonate film) is preferable. In the invention, a biaxially stretched polyethylene terephthalate film is particularly preferred. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm.
m.

The heat-developable recording material of the present invention may be developed by any method, but is usually developed by elevating the temperature of the heat-developable recording material exposed imagewise. The preferred development temperature is 105 to 145C, more preferably 107 to 140C. The development time is 1 to 18
0 second, more preferably 7 to 50 seconds, and particularly preferably 8 to 25 seconds.

The heat-developable recording material of the present invention is preferably heat-developed by a heat developing machine. The heat-developable recording material is susceptible to temperature variations in the heat-development section, and tends to cause uneven development. Therefore, Japanese Patent Application Laid-Open Nos. 9-297384 and 9-297
No. 385, No. 9-297386, a heat drum type automatic heat developing machine, WO 98/27
No. 458, a flat transport type automatic thermal developing machine is used. Further, an automatic thermal developing machine having a preheating section in front of the thermal developing section and having a preheating temperature of 80 to 120 ° C. is preferably used. The preheating advances development and reduces density unevenness, so that it is also effective for scanning unevenness. Further, one surface of the photosensitive material is brought into contact with a fixed heating member as described in JP-A-11-133572, and the photosensitive material is conveyed while pressing the other surface of the photosensitive material against the heating member with a plurality of rollers. It is also preferable to carry out a heat development treatment using an apparatus for performing the heat development.

The heat-developable recording material of the present invention may be exposed by any method, but a laser beam is preferred as an exposure light source. As the laser beam according to the present invention, a gas laser, a YAG laser, a dye laser, a semiconductor laser and the like are preferable. Among them, in order to prevent interference fringes and uneven exposure of halftone dots, vertical multi-exposure or oblique exposure is preferable.

[0104]

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 >> (Preparation of subbed photographic support) 8 W
/ M ² · min, and apply the following undercoating coating liquid a-1 on one surface so that the dry film thickness is 0.8 μm, and dry to form an undercoating layer A-1. On the opposite surface, the following antistatic coating solution b-1 was applied with a dry film thickness of 0.8.
The coating was applied so as to have a thickness of μm, followed by drying to obtain an antistatic processed subbing layer B-1.

[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 (C-1) 0.6 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 Finished to 1 L with water [Subbing coating solution b-1] SnO ₂ / Sb (9/1 mass ratio, average particle size 0.18 μm) Amount to become 200 mg / m ² Butyl acrylate (40 mass %), Styrene (20% by mass), glycidyl acrylate (40% by mass) copolymer latex liquid (solid content 30%) 270 g (C-1) 0.6 Finish 1L hexamethylene-1,6-bis (ethyleneurea) 0.8 g Water.

Subsequently, the undercoat layer A-1 and the undercoat layer B-1
8 W / m ² · min. Of corona discharge is applied to the surface of the undercoating layer A-1. It is applied as a pull-up layer A-2, and a lower pull-up layer coating solution b-2 shown below is coated on the lower pull layer B-1.
Was applied as an undercoating upper layer B-2 having an antistatic function so that the dry film thickness was 0.8 μm.

[Lower Coating Upper Layer Coating Solution a-2] Gelatin 0.4 g / m ² Mass (C-1) 0.2 g (C-2) 0.2 g (C-3) 0.1 g Silica particles ( (Average particle size 3 μm) 0.1 g Finished to 1 L with water [Lower upper layer coating solution b-2] (C-4) 60 g Latex solution containing (C-5) as a component (solid content 20%) 80 g Ammonium sulfate 0. 5 g (C-6) 12 g Polyethylene glycol (weight average molecular weight 600) 6 g Finish to 1 L with water.

[0109]

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[0110]

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<Heat treatment of the support> In the above-mentioned undercoat drying step of the undercoated support, the support was heated at 140 ° C.
Thereafter, it was gradually cooled. At that time, it was transported at a tension of 1 × 10 ⁵ Pa.

(Preparation of Photosensitive Emulsion A) <Preparation of Silver Halide Emulsion A> In 900 ml of water, 7.5 g of inert gelatin and 10 mg of potassium bromide were dissolved to adjust the temperature to 35 ° C. and the pH to 3.0. After the combination, 370 ml of an aqueous solution containing 74 g of silver nitrate and potassium bromide and potassium iodide at a molar ratio of (98/2) were equimolar to silver nitrate.
[Ir (NO) Cl ₅ ] salt was added at 1 × 10 ⁻⁶ per mole of silver.
370 ml of an aqueous solution containing 1 × 10 ⁻⁶ mol per mol of silver and a rhodium chloride salt was added at a constant speed over 10 minutes by the double jet method. Thereafter, 4-hydroxy-
6-Methyl-1,3,3a, 7-tetrazaindene was added, the pH was adjusted to 5.0 with NaOH, and the [100] face ratio of 87 with an average particle size of 0.06 μm and a dispersity of 45% was 87.
% Of non-monodispersed cubic silver iodobromide grains.

The emulsion was coagulated and precipitated using a gelatin coagulant, and after desalting, 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and the pAg to 7.5. Furthermore, chloroauric acid, inorganic sulfur, thiourea dioxide and 2,3,4
Chemical sensitization was performed with 5,6-pentafluorophenyldiphenylphosphine selenide to obtain a silver halide emulsion A.

<Preparation of sodium behenate solution> 945
8 ml of pure water, 32.4 g of behenic acid, and 9 of arachidic acid.
9 g and stearic acid 5.6 g 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, 0.93m of concentrated nitric acid
After adding 1 l, the mixture was cooled to 55 ° C. and stirred for 30 minutes to obtain a sodium behenate solution.

<Preparation of Preform Emulsion A> The silver halide emulsion A was added to the sodium behenate solution prepared above.
Was added, and the pH was adjusted to 8.0 with sodium hydroxide solution.
After adjusting to 1, 147 ml of a 1 mol / L silver nitrate solution
Was added over 1 minute, the mixture was further stirred for 15 minutes, and water-soluble salts were removed by ultrafiltration. The produced silver behenate was needle-shaped particles having a long side average size of 0.8 μm. After the floc of the dispersion was formed, water was removed, and water washing and water removal were further performed six times, followed by drying to prepare Preform Emulsion A.

<Preparation of Photosensitive Emulsion A Containing Organic Silver Salt A> To the obtained preform emulsion A, 544 g of a solution of polyvinyl butyral (average molecular weight: 3,000) in methyl ethyl ketone (17% by mass) and 107 g of toluene were added. After slowly adding and mixing, the mixture was dispersed at 4000 psi. After dispersion, as a result of observing the organic silver salt particles with an electron micrograph,
It was a non-monodispersed organic silver salt having an average particle size of 0.7 μm and a degree of dispersion of 60%. When the organic silver salt particles were similarly observed after coating and drying, the same particles were confirmed. This emulsion 2
To 40 g, 4.7 ml of a 0.01% methanol solution of calcium bromide was added to obtain photosensitive emulsion A. When the silver halide grains in these were observed with an electron microscope,
No silver halide grains of 0.01 μm or less were observed.

(Coating of Back Layer Surface Side) The coating liquid 1 of the back layer and the coating liquid 1 of the back protective layer having the following compositions were respectively filtered using a filter having a quasi-absolute filtration accuracy of 20 μm before coating, and then prepared by an extrusion coater. A total wet film thickness of 30 on the antistatically treated undercoat layer B-2 surface of the support thus prepared.
μm, apply at a speed of 120 m / min.
For 4 minutes.

[Back Layer Coating Solution 1] Cellulose acetate butyrate (10% methyl ethyl ketone solution) 15 ml / m ² Dye-A 20 mg / m ² Dye-B 20 mg / m ²

[0119]

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[Coating liquid for back protective layer] Cellulose acetate butyrate (10% methyl ethyl ketone solution) 5 ml / m ² matting agent (monodisperse silica having a monodispersion degree of 15% and an average particle size of 8 μm) 15 mg / m ² (CH ₃ ) ₃ SiO [(CH ₃ ) ₂ SiO] ₂₀ [CH ₃ SiO ｛CH ₂ CH ₂ CH ₂ O (CH ₂ CH ₂ O) ₁₀ (CH ₂ CH ₂ CH ₂ O) ₁₅ CH ₃ }] ₃₀ Si (CH _{3 3} ) 10 mg / m ² Fluorosurfactant: C ₉ F ₁₇ (CH ₂ CH ₂ O) ₂₂ C ₉ F ₁₇ 10 mg / m ² Compound shown in Table 1 5 mg / m ² (coating on the recording layer side) The coating solution A of the recording layer and the coating solution 1 of the surface protective layer thereon were filtered using a filter having a quasi-absolute filtration accuracy of 20 μm. 100m / min on two sides And multi-layer coating in degrees. At this time, the silver was applied such that the amount of silver applied was 1.5 g / m ² . Thereafter, the sample was dried at 65 ° C. for 1 minute.

[Recording Layer Coating Solution A] Photosensitive Emulsion A 240 g Sensitizing dye (0.1% methanol solution) 1.7 ml 2- (4-chlorobenzoyl) benzoic acid (12% methanol solution) 9.2 ml 2- Mercaptobenzimidazole (1% methanol solution) 11 ml Compounds of general formulas (2) to (4) 0.5 g Acid anhydride 0.5 g O-25 0.4 g A-1 (20% methanol solution) 29.5 ml Phthalazine 0 0.2 g 4-methylphthalic acid 0.25 g tetrachlorophthalic acid 0.2 g polyester polyurethane compound (UR8300 manufactured by Toyobo Co., Ltd., average molecular weight 39000) 20 g alkoxysilane compound: PhNH (CH ₂ ) Si (OCH ₃ ) ₃ 1 g [coating of surface protective layer] Liquid 1] acetone 5 ml / m ² methyl ethyl ketone 21 ml / m ² cellulose acetate Tobutyrate 2.3 g / m ² Methanol 7 ml / m ² Phthalazine 250 mg / m ² Matting agent: silica having an average particle size of 5.5 μm 10 mg / m ² Vinyl sulfone compound: VS-1 35 mg / m ² Fluorinated surfactant: C ₁₂ F ₂₅ (CH ₂ CH ₂ O) ₁₀ C ₁₂ F ₂₅ 10 mg / m ²

[0122]

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[0123]

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As described above, a heat-developable recording material having the structure shown in Table 1 was produced. The amount of solvent methyl ethyl ketone (MEK) remaining in the prepared sample was 7
It was 0 mg / m ² .

[Evaluation of Maximum Density Dmax and Minimum Density Dmin]
Exposure through a wedge was performed from the side of the recording layer side by an exposure machine using a semiconductor laser having a wavelength of 780 nm in a longitudinal multi-mode using a high-frequency superposition method described in No. 130494 as an exposure source. Each second heat-developed recording material was prepared by performing a heat development treatment for 2 seconds.

Each of the developed samples thus prepared was measured with an optical densitometer (PD-6 manufactured by Konica) through a filter for cutting light of 420 nm or more, and the abscissa-exposure amount (Log) was used.
E), a characteristic curve composed of the vertical axis and the optical density (D) was prepared. The maximum density Dmax and the minimum density Dmin in the obtained characteristic curve were determined.

[Evaluation of Storage Stability of Raw Sample] Each of the heat-developable recording materials prepared above was divided into two parts, one of which was 23 ° C., 50% R
H for 3 days. The other at 55 ° C, 3 without humidity adjustment
It was stored for days and subjected to forced deterioration treatment. Thereafter, exposure was performed from the recording layer surface side in the same manner as described above.

The exposed sample was processed by a dry view processor 2771 which is a thermal developing machine for printing plate making dry film manufactured by Kodak Polychrome Graphics Co., Ltd.
Heat development was performed at 20 ° C. for 20 seconds. The automatic developing machine for a dry film is a flat transport type thermal developing machine having a preheating section of about 110 ° C. The total time required for the sample from entering the thermal developing machine to exiting the thermal developing machine is 48 hours. Seconds. The optical density of the obtained sample was measured, a characteristic curve was prepared in the same manner as above, and the sensitivity was calculated. The sensitivity was represented by the reciprocal of the exposure amount giving a density of 2.5. The storage stability was defined as log (Sa / Sb), where Sa was the sensitivity of a sample stored at 23 ° C. and 50% RH for 3 days, and Sb was the sensitivity of a sample processed at 55 ° C. for 3 days without humidity adjustment. It was calculated and used as a scale. As for this value, 0 indicates that the stability is the best, and if it is far from 0, the storage stability is poor. Further, the minimum density Dmin 'at the time of the forced deterioration treatment was also measured.

[0129]

[Table 1]

As shown in Table 1, the compound of the general formula (1) or the secondary or tertiary compound having a molecular weight of 150 or more was provided on the side opposite to the recording layer.
Samples 1 to 4 of the present invention having a secondary amino compound and having a compound functioning as a high contrast agent on the recording layer side were compared with Comparative Samples 5 to 8 having only a compound functioning as a high contrast agent on the recording layer side. In comparison, a clear performance difference is observed under a high temperature atmosphere.

Also, when comparing Samples 10 and 11 of the present invention having a compound of the general formula (1) or a secondary or tertiary amino compound having a molecular weight of 150 or more on the side opposite to the recording layer with Sample 9, which is a comparative example thereof, Again, a clear performance difference is seen in a high temperature atmosphere.

[0132]

According to the present invention, a heat-developable recording material having improved performance deterioration under a high-temperature atmosphere can be provided.

Claims (9)

[Claims] 1. An organic silver salt on one side of a transparent support,
In a heat-developable recording material having a recording layer containing a photosensitive silver halide and a heat-reducing reducing agent, and having a dye-containing layer on the side opposite to the side having the recording layer, the surface having the dye-containing layer A heat-developable recording material characterized in that at least one layer contains a compound of the formula (1). Embedded image (Wherein, X ₁ represents an oxygen atom or a ＮＨNH group; R ₁ and R ₂ each independently represent a hydrogen atom, an acyl group, a hydrocarbon group, or a carbamoyl group; provided that when X ₁ is an oxygen atom, At least one of R ₁ and R ₂ is a hydrogen atom.
L ₁ represents a divalent organic group necessary for forming a cyclic structure. ) 2. The heat-developable recording material according to claim 1, wherein the layer containing the compound of the general formula (1) is the outermost layer on the side opposite to the side having the recording layer. 3. An organic silver salt on one side of a transparent support,
In a heat-developable recording material having a recording layer containing a photosensitive silver halide and a heat-reducing reducing agent, and having a dye-containing layer on the side opposite to the side having the recording layer, the surface having the dye-containing layer A heat-developable recording material characterized in that at least one layer contains a secondary or tertiary amino compound having a molecular weight of 150 or more. 4. The heat-developable recording material according to claim 3, wherein the layer containing a secondary or tertiary amino compound having a molecular weight of 150 or more is the outermost layer on the side opposite to the side having the recording layer. 5. The heat-developable recording material according to claim 3, wherein the secondary or tertiary amino compound having a molecular weight of 150 or more is a compound having a plurality of amino groups in one molecule. 6. The heat development recording material according to claim 5, wherein the secondary or tertiary amino compound having a plurality of amino groups in one molecule and having a molecular weight of 150 or more is polyethyleneimine. 7. The heat-developable recording material according to claim 1, wherein the recording layer and / or a layer adjacent to the recording layer contains a compound of the general formula (2). General formula (2) R ₃ —N (R ₄ ) —N (R ₅ ) —CHO (wherein R ₃ is an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, a heterocyclic group, a substituted heterocyclic group R ₄ and R ₅ each independently represent a hydrogen atom or an alkyl group, provided that at least one of R ₄ and R ₅ is a hydrogen atom.) 8. The heat-developable recording material according to claim 1, wherein the recording layer and / or a layer adjacent to the recording layer contains a compound of the general formula (3). Embedded image (In the formula, one of R ₆ and R ₇ is a cyano group, and the other represents an arbitrary monovalent substituent. M represents a hydrogen atom or an alkali metal atom.) 9. The heat-developable recording material according to claim 1, wherein the recording layer and / or a layer adjacent to the recording layer contains a compound of the general formula (4). Embedded image (In the formula, M represents a hydrogen atom or an alkali metal atom.
L ₂ represents a divalent organic group necessary for forming a cyclic structure. )