JP2001290239A - Method for producing heat developable photographic sensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a heat developable photographic sensitive material which stably gives an image having a cold black tone without causing a considerable change in performances (fogging and sensitivity) of the sensitive material due to the stagnancy of a coating fluid containing an organic silver salt and a reducing agent. SOLUTION: In the method for producing the heat developable photographic sensitive material containing an organic silver salt, photosensitive silver halide grains and a reducing agent on the base and having at least one photosensitive layer (image forming layer) and at least one protective layer, two or more selected from the reducing agent, an antifoggant, a hardening agent, a toning agent, a coloring material (dye), a surfactant and a matting agent are added to a coating fluid within 3 hr before coating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a photothermographic material, and more particularly, to a technique for producing a photothermographic material which has low fog, good sensitivity, and can provide a cool black image.

[0002]

2. Description of the Related Art Conventionally, in the field of printing plate making and medical care,
Waste liquids associated with wet processing of image forming materials have become a problem in terms of workability, and in recent years, reduction in the amount of processing waste liquids has been strongly desired from the viewpoint of environmental conservation and space saving. Therefore, with a laser imagesetter or laser imager,
There has been a need for a technique relating to a photothermographic material capable of efficient exposure and capable of forming a high-resolution, clear black image.

As a technique for this, a silver halide photographic light-sensitive material (hereinafter, also referred to as a heat-sensitive material) which forms a photographic image by heat treatment is known. For example, US Pat.
No. 2,904, 3,457,075 and D.C. Morgan and B.A. "The Silver System Treated by Heat (Thermal)" by Shelly
ly Processed Silver System
ms) ", Imaging Processes and Materials
nd Materials) Neblette No. 8
Edition, Sturge, V.S. Walworth, A .; Shepp, 2nd page, 1969, etc.

[0004] Such a heat-sensitive material is usually prepared by dispersing a reducible silver source (organic silver salt), a catalytically active amount of a photocatalyst (silver halide) and a reducing agent in an organic binder matrix. Contains. The heat-sensitive material is stable at room temperature, but when heated to a high temperature after exposure, generates silver by a redox reaction between a reducible silver source (acting as an oxidizing agent) and a reducing agent.

[0005] This oxidation-reduction reaction is promoted by the catalytic action of the latent image generated by 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 an image is formed. An antifoggant for controlling the fogging of this image is used, and the most effective method as a conventional antifoggant technique is a method using a mercury compound as the antifoggant.

The use of mercury compounds as antifoggants is disclosed, for example, in US Pat. No. 3,589,903. However, the use of mercury compounds is not preferred, and the development of non-mercury-based antifoggants has been desired.

Non-mercury antifoggants include various polyhalides, for example, US Pat.
4,946, 4,756,999, 5,34
0,712, European Patent 605,981A1, 62
2,666 A1, 631, 176 A1, No. 5
4-165 and JP-A-7-2781. However, the compounds described in these publications have a problem that the antifogging effect is low or the color tone of silver is deteriorated. Furthermore, when the heat-sensitive material is stored in a laminated form in a humidified state and stored under forced deterioration conditions of heating, and then subjected to exposure and development, there is a problem that fog in an unexposed portion rises, and these problems are eliminated. The development of antifoggants has been desired.

As a method for solving this, Japanese Patent Laid-Open No. 9-1
No. 60164, No. 9-244178, No. 9-2583
No. 67, No. 9-265150, No. 9-281640
And No. 9-319022 describe polyhalogen compounds having the above-mentioned disadvantages improved. However,
In particular, these compounds were applied to a heat-sensitive material for medical laser imagers, or to a heat-sensitive material for output of a laser image setter for printing having a lasing wavelength of 600 to 800 nm, containing a contrast agent. In this case, although the above-mentioned drawback is considerably improved, the developed sample has a drawback that the fog rises with time, and the storage stability of the image with time deteriorates.

Further, Japanese Patent Application Laid-Open No. 6-208193 discloses a heat-sensitive material having improved fog stability during storage by containing a halogenated antifoggant and a compound having an isocyanate group. However, the storage stability of images over time is not at a sufficient level, and the reaction of these antifoggants progresses with time at the stage of the coating solution during the manufacturing process, and the sensitivity of the heat-sensitive material becomes low. There was a major drawback that varied greatly.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to stabilize the performance of a photothermographic material stably without a large fluctuation due to stagnation of a coating solution containing an organic silver salt and a reducing agent.
Another object of the present invention is to provide a method for producing a heat-developable photographic light-sensitive material capable of obtaining a cool black image. Another object of the present invention is to provide a method for producing an organic silver salt in which fog is reduced in the production process of the organic silver salt.

[0011]

It is known to add a reducing agent immediately before coating and an antifoggant to a heat-sensitive material. However, as a result of diligent research by the present inventors, the following has been found. It has been found that the above problem can be solved by means.

A heat-developable photographic material comprising an organic silver salt, photosensitive silver halide particles and a reducing agent on a support and having at least one photosensitive layer (image forming layer) and at least one protective layer. In the production method, at least two or more of a reducing agent, an antifoggant, a hardener, a color tone, a dye (dye), a surfactant, and a matting agent are added to a coating solution within 3 hours of coating. Material manufacturing method.

It is preferred that the protective layer is simultaneously coated on the photosensitive layer, and that the photosensitive layer and the protective layer are simultaneously coated by a pre-metering coater.

Hereinafter, the present invention will be described in more detail. In the present invention, each additive including the reducing agent is added to the coating solution of any layer on the side containing the photosensitive silver halide grains, and is coated on the support within 3 hours after the addition. Is done.
Preferably it is within one hour, more preferably immediately before application. It is preferable that the additives added before the application are added alone.

In the present invention, the order of adding the additives is not particularly limited. They may be added in any order. This is because it is significant to add immediately before coating.

As a means for mixing immediately before coating, mixing in a stagnant pot (feed pot) or in a coater liquid sending line is general, but any method may be used. If the time from mixing to coating is long, various additives react with each other or deteriorate, causing an increase in fog and a change in sensitivity.

The photosensitive silver halide used in the heat-sensitive material of the present invention can be prepared by any method known in the field of photographic technology such as a single jet method or a double jet method, for example, an ammonia method emulsion, a neutral method, It can be prepared by any method such as an acidic method. Thus, it can be prepared in advance and then 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. No. 5,565, 3,713,833, 3,748,143, British Patent 1,362,970, etc., means using a polymer other than gelatin such as polyvinyl acetal, and British Patent 1 Means for Enzymatically Degrading the Gelatin of a Light-Sensitive Silver Halide Emulsion as described in U.S. Pat. No. 4,354,186, or Using Surfactants as described in U.S. Pat. No. 4,076,539. By preparing in the presence of, various means such as omitting the use of the protective polymer can be applied.

The silver halide functions as an optical sensor, and preferably has a small grain size in order to suppress white turbidity after image formation and obtain good image quality.
0.1 μm or less in average particle size, preferably 0.01
To 0.1 μm, particularly preferably 0.02 to 0.08 μm. The shape of the silver halide is not particularly limited,
So-called normal crystals of cubic and octahedral, spherical shapes that are not normal crystals,
There are rod-shaped and flat-shaped particles. The silver halide composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide, and silver iodide.

The amount of silver halide is 50% or less, preferably 25% or less, based on the total amount of silver halide and the organic silver salt described below.
To 0.1%, more preferably 15 to 0.1%.

As described in British Patent 1,447,454, the photosensitive silver halide to be used may be prepared by adding a halogen component such as a halide ion to an organic silver salt forming component when preparing an organic silver salt. By coexisting with silver ions and implanting silver ions, organic silver salts can be generated almost simultaneously. As still another method, a silver halide-forming component is allowed to act on a previously prepared solution or dispersion of an organic silver salt or a sheet material containing the organic silver salt, so that a part of the organic silver salt is subjected to photosensitive halogenation. It can also be converted to silver.

The silver halide thus formed is in effective contact with the organic silver salt and exhibits a favorable effect.
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 be determined. That is, an organic silver salt is mixed with a compound to be tested, and if necessary, after heating, it is examined whether or not there is a peak peculiar to silver halide by X-ray diffraction. 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. Is disclosed in U.S. Pat.
No. 39, No. 3,457,075, No. 4,003,74
No. 9, British Patent No. 1,498,956 and
Nos. 27027, 53-25420, etc., examples of which are shown below.

(1) Inorganic halide: a halide represented by MXn (where M represents H, NH ₄ or a metal atom, n is 1 when M is H and NH ₄ , and M is a metal When it is an atom, it represents its valency, such 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: quaternary ammonium halides such as trimethylphenylammonium bromide, cetylethyldimethylammonium bromide and trimethylbenzylammonium bromide; quaternary phosphonium halides such as tetraethylphosphonium bromide; trimethylsulfonium iodide Tertiary sulfonium halides and the like.

(3) Halogenated hydrocarbons: iodoform, bromoform, carbon tetrachloride, 2-bromo-2-
Methyl propane and the like.

(4) N-halogen compounds: N-chlorosuccinimide, N-bromosuccinimide, N-bromophthalimide, N-bromoacetamide, N-iodosuccinimide, N-bromophthalazone, N-bromooxa Zolinone, N-chlorophthalazone, N-bromoacetanilide, N, N-dibromobenzenesulfonamide, N-bromo-N-methylbenzenesulfonamide, 1,3-dibromo-4,4-dimethylhydantoin, N-bromourazole etc.

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

These silver halide forming components are used in a small amount stoichiometrically with respect to the organic silver salt. Usually, the range is from 0.001 to 0.7 mol per mol of the organic silver salt,
Preferably it is 0.03-0.5 mol. Two or more silver halide forming components may be used in combination within the above range.

Various conditions such as a reaction temperature, a reaction time, and a reaction pressure in the step of converting a part of the organic silver salt into silver halide using the above-mentioned silver halide-forming component are appropriately set according to the purpose of production. Usually, the reaction temperature is-
20 to 70 ° C., the reaction time is 0.1 second to 72 hours,
The reaction pressure is preferably set at atmospheric pressure. This reaction is also preferably performed in the presence of a polymer used as a binder described below. The amount of the polymer used at this time 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 above-mentioned various methods may be chemically sensitized with a sulfur-containing compound, a gold compound, a platinum compound, a palladium compound, a silver compound, a tin compound, a chromium compound or a combination thereof. Can be done. The method and procedure of this chemical sensitization are described in, for example, US Pat. No. 4,036,650 and British Patent 1,51.
No. 8,850, JP-A-51-22430, JP-A-51-7
Nos. 8319 and 51-81124. Further, when a part of the organic silver salt is converted into photosensitive silver halide by a silver halide forming component, US Pat.
As described in U.S. Pat. No. 0,482, a low molecular weight amide compound may be used in order to achieve sensitization.

The photosensitive silver halide includes metals belonging to Groups 6 to 10 of the Periodic Table of the Elements in order to prevent illuminance failure and gradation adjustment.
For example, ions such as Rh, Ru, Re, Ir, Os, and Fe, and complexes or complex ions thereof can be contained. It is particularly preferable to add as a complex ion. For example, Ir complex ion such as IrCl ₆ ^2- may be added due to illuminance failure.

In the present invention, the organic silver salt is a reducible silver source, and is a silver salt of an organic acid or a hetero organic acid, particularly a long-chain (10 to 30, preferably 15 to 25) aliphatic carboxylic acid. And silver salts of nitrogen-containing heterocyclic compounds.
The ligand has a total stability constant for silver ions of 4.0 to 4.0.
Organic or inorganic complexes having a value of 10.0 are also preferred. Examples of suitable silver salts include Research Disclosure (hereinafter RD)
17029 and 29996).
The following are mentioned.

Silver salts of organic acids such as gallic acid, oxalic acid, behenic acid, stearic acid, arachidic acid, palmitic acid,
Silver salts such as lauric acid. Silver carboxyalkylthiourea salts, for example, silver salts such as 1- (3-carboxypropyl) thiourea and 1- (3-carboxypropyl) -3,3-dimethylthiourea. Polymers of aldehydes with hydroxy-substituted aromatic carboxylic acids [aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.), hydroxy-substituted acids (salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid)] Silver salts or complexes of reaction products; silver salts or complexes of thiones, such as 3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-2-thione and 3-carboxymethyl-4-thiazoline- Silver salts or complexes such as 2-thione; imidazole, pyrazole, urazole, 1,2,2
4-thiazole and 1H-tetrazole, 3-amino-
A complex or salt of silver and a nitrogen acid selected from 5-benzylthio-1,2,4-triazole and benzotriazole; a silver salt such as saccharin and 5-chlorosalicylaldoxime; and a silver salt of a mercaptide.

Among these, preferred silver salts are silver behenate, silver arachidate or silver stearate.

The organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound which forms a complex with silver, and includes a forward mixing method, a reverse mixing method, a simultaneous mixing method, and a method 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 (sodium behenate, sodium arachidate, etc.) is prepared by adding an alkali metal salt (sodium hydroxide, potassium hydroxide, etc.) to an organic acid, and then controlled double jet is performed. A soap and silver nitrate are added to produce organic silver salt crystals. At that time, silver halide grains may be mixed.

The organic silver salt has an average particle size of 2 μm or less,
It is preferably monodispersed. The average particle size of the organic silver salt refers to the diameter of a sphere equivalent to the volume of the organic silver salt particles when the particles of the organic silver salt are, for example, spherical, rod-shaped, or tabular particles. The average particle size is preferably 0.0
It is preferably from 5 to 1.5 μm, particularly preferably from 0.05 to 1.0 μm. The monodispersion has the same meaning as in the case of silver halide, and preferably has a monodispersity of 1 to 30.

In the present invention, the tabular grains of the organic silver salt preferably have at least 60% of the total organic silver. In the present invention, the tabular grains refer to those having an aspect ratio (abbreviated as AR) of 3 or more, which is a ratio between an average particle diameter and a thickness, which is represented by the following formula.

AR = average particle size (μm) / thickness (μm) In order to form organic silver into these shapes, the organic silver crystal is obtained by dispersing and pulverizing the organic silver crystal with a binder, a surfactant and the like using a ball mill or the like. Can be Within this range, a heat-sensitive material having a high density and excellent image storability can be obtained.

In order to prevent devitrification of the light-sensitive material, the total amount of silver halide and organic silver salt is preferably 0.5 to 2.2 g per m ² in terms of silver. With this range, a high-contrast image can be obtained. The amount of silver halide relative to the total amount of silver is 50% or less by mass, preferably 25% or less, and more preferably 0.1 to 15%.

The organic silver salt particles used in the heat-sensitive material of the present invention are organic silver salt fine particles prepared by using an ultrafiltration device.

The production method of the present invention is carried out using an apparatus capable of preparing organic silver salt particles, and includes a reaction vessel in which organic silver salt particles are formed and various kinds of liquid used in forming organic silver salt particles. It has an addition liquid addition line, a stirring mechanism for mixing the reactant solution and the various addition liquids, and has an ultrafiltration device. The ultrafiltration device may be installed in the reaction vessel, but is preferably connected to the reaction vessel by a pipe or the like,
It is possible to circulate the reactant solution at an arbitrary flow rate in the reaction vessel and the ultrafiltration device by a circulation mechanism of the reactant solution such as a pump, and to stop the reaction solution arbitrarily. This equipment has a device for detecting the volume of an aqueous solution containing a salt extracted from an object solution and a mechanism capable of arbitrarily controlling the amount. Further, other functions can be provided as needed.

In general, the step of preparing an organic silver salt comprises a step of converting a dissolved organic acid into sodium soap, a step of adding silver nitrate after addition of a fine-grain silver halide emulsion, and a step of adding silver nitrate. Drying is performed after washing and dehydration steps to obtain a dry powder of an organic silver salt.

There are no particular restrictions on the ultrafiltration module and the circulating pump that can be used in carrying out the ultrafiltration, but they act on organic silver salt grains and silver halide emulsions to adversely affect photographic performance and the like. It is preferable to avoid such materials and structures. The molecular weight cutoff of the ultrafiltration membrane used in the ultrafiltration module can be arbitrarily selected.
For example, when it is desired to remove a dispersion medium such as gelatin contained in a silver halide emulsion or a compound used in preparing an emulsion during the grain growth process, an ultrafiltration membrane having a molecular weight cut off greater than the molecular weight of the object to be removed is selected. If the removal is not desired, an ultrafiltration membrane having a molecular weight cut off less than the molecular weight of the object to be removed can be selected.

The photothermographic material of the present invention contains a reducing agent. Examples of suitable reducing agents are described in US Pat.
0,448, 3,773,512, 3,59
No. 3,863, RD17029 and 29963, and include the following.

Aminohydroxycycloalkenone compounds (such as 2-hydroxypiperidino-2-cyclohexenone); aminoreductones (re
ductones) (piperidinohexose reductone monoacetate, etc.); N-hydroxyurea derivatives (N-p-methylphenyl-N-hydroxyurea, etc.); hydrazones of aldehydes or ketones (anthracene aldehyde phenylhydrazones, etc.); Phamidophenols; Phosphaamidoanilines; Polyhydroxybenzenes (such as hydroquinone, t-butyl-hydroquinone, i-propylhydroquinone, and (2,5-dihydroxyphenyl) methylsulfone); sulfhydroxamic acids (benzenesulfuric acid) Hydroxamic acid); sulfonamidoanilines (such as 4- (N-methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (such as 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone ; Tetrahydroquinoxaline acids (1,2,3,4-tetrahydroquinoxaline, etc.);
Amidooxins; Azines (combinations of aliphatic carboxylic acid arylhydrazides and ascorbic acid, etc.); Combinations of polyhydroxybenzene and hydroxylamine, reductone or hydrazine; Hydroxanoic acids; -Cyanophenylacetic acid derivatives; Combinations of bis-β-naphthol and 1,3-dihydroxybenzene derivatives; 5-pyrazolones; Sulfonamidophenol reducing agents; 2-phenylindane-1,3-dione, etc .; -Dihydropyridines (2,6-dimethoxy-3,5-dicarbethoxy-1,4-dihydropyridine and the like); bisphenols (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, etc.), ultraviolet-sensitive ascorbic acid derivatives and 3-pyrazolidones.

Among these, particularly preferred reducing agents are hindered phenols. Examples of the hindered phenols include compounds represented by the following general formula (A).

[0046]

Embedded image

In the formula, R ₁ is a hydrogen atom or a group having 1 to 1 carbon atoms.
Represents 10 alkyl groups (butyl, 2,4,4-trimethylpentyl, etc.), and R ₂ and R ₃ each have 1 carbon atom
To 5 alkyl groups (methyl, ethyl, t-butyl, etc.).

Specific examples of the compound represented by formula (A) are shown below, but it should not be construed that the invention is limited thereto.

[0049]

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[0050]

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The amount of the reducing agent including the compound represented by formula (A) is 1 × 10 ^-2 to 1 mol of silver.
It is preferably 10 mol, and particularly preferably 1 × 10 ^-2 to 1.
5 moles.

A preferred aryl compound having at least one halogenated group thereon (an antifogged halogenated compound) for improving the fog stability during storage of the hot silver light-sensitive material of the present invention is represented by the following general formula ( Indicated by I).

[0053] Formula _{(I) Ar- (SO 2)} y -CH 3-n X n wherein, Ar is an aromatic or heteroaromatic group, y is 0 or 1,
X is a halogen atom, and n is 1, 2 or 3.

Specific examples of the compounds included in the general formula (I) are described in US Pat. Nos. 4,546,075 and 4,756,9
Nos. 99, 4,452,885 and 3,874,94
No. 6, 3,955, 982 and the like. Other halogen compounds considered to be useful in the present invention include dihalogen compounds as described in JP-A-59-57234.

The antifoggant compound is contained in the silver or top coat layer in an amount of from 5 × 10 ^-4 to 1 mol of total silver.
It is contained in an amount of 0.5 mol, preferably 5 × 10 ^{−3 to} 5 × 10 ⁻² mol.

Representative examples of the halogenated antifoggant compound preferably used are listed below, but the present invention is not limited thereto.

[0057]

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[0058]

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[0059]

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In the hot silver sensitive material, 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 has a function of participating in the oxidation-reduction reaction between the organic silver salt and the reducing agent to make the resulting silver image dark, particularly black. Examples of suitable toning agents are disclosed in RD 17029 and include:

Imides (such as phthalimide); cyclic imides, pyrazolin-5-ones and quinazolinones (succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-
Naphthalimides (such as N-hydroxy-1,8-naphthalimide); cobalt complexes (such as hexamine trifluoroacetate of cobalt); and mercaptans (such as 3-mercapto-1,2,4-).
N- (aminomethyl) aryldicarboximides (such as N- (dimethylaminomethyl) phthalimide); combinations of blocked pyrazoles, isothiuronium derivatives and certain photobleaches (N,
N'-hexamethylene (1-carbamoyl-3,5-dimethylpyrazole), 1,8- (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate, etc.), and 2- (tribromomethylsulfonyl) A) benzothiazole combination); merocyanine dye (3-ethyl-5-((3-ethyl-2-benzothiazolinylidene (benzothiazolinylidene))-1-methylethylidene) -2-thio-2, 4-oxazolidinedione, etc.);
Phthalazinone, phthalazinone derivatives or metal salts of these derivatives (4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone, 2,3-dihydro-1,4-phthalazinedione, etc. );
Combination of phthalazinone and sulfinic acid derivative (6-chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate); combination of phthalazine + phthalic acid; phthalazine (including phthalazine adduct) And maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-
Combination with at least one compound selected from phenylene acid derivatives and their anhydrides (phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride); quinazolinediones, benzoxazines, naloxazine derivatives Benzoxazine-2,4
-Diones (1,3-benzoxazine-2,4-dione); pyrimidines and asymmetric triazines (2,4-
Dihydroxypyrimidine, etc.) and tetraazapentalene derivatives (3,6-dimercapto-1,4-diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene etc.).

Preferred toning agents are phthalazone or phthalazine. Binders suitable for the hot silver sensitive material of the present invention are transparent or translucent, generally colorless, natural polymer synthetic resins and polymers and copolymers, and other film-forming media such as gelatin, gum arabic,
Poly (vinyl alcohol), hydroxyethylcellulose, cellulose acetate, cellulose acetate butyrate, polyvinylpyrrolidone, casein, starch, polyacrylic acid, polymethylmethacrylic acid, polyvinyl chloride, polymethacrylic acid, copoly (styrene-maleic anhydride), Copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (polyvinyl formal, polyvinyl butyral, etc.), polyesters, polyurethanes, phenoxy resins, polyvinylidene chloride, polyepoxides, polycarbonates, polyvinyl acetate , Cellulose esters and polyamides, which may be hydrophilic or non-hydrophilic.

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

In order to increase the speed of thermal development, the amount of the binder in the photosensitive layer in the present invention is preferably 1.5 to 10 g / m ² . 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.

In the present invention, a matting agent is preferably contained on the photosensitive layer side, and in order to prevent damage to the image after thermal development, it is preferable to provide a matting agent on the surface of the photosensitive material. It is preferable that the matting agent is contained in a weight ratio of 0.5 to 30% based on all binders on the photosensitive layer side.

When a non-photosensitive layer is provided on the opposite side of the photosensitive layer with the support interposed therebetween, it is preferable that at least one layer on the non-photosensitive layer side contains a matting agent, so that the light-sensitive material has slipperiness and fingerprint adhesion. For prevention, it is preferable to provide a matting agent on the surface of the photosensitive material. The matting agent is preferably contained in a weight ratio of 0.5 to 40% with respect to all binders on the non-photosensitive layer side.

The material of the matting agent used may be either an organic substance or an inorganic substance. As inorganic materials, Swiss Patent 3
Silica described in No. 30,158, French Patent 1,29
Glass powder described in US Pat.
Alkaline earth metals or carbonates such as cadmium and zinc described in 3,181 and the like can be used as a matting agent. Examples of organic substances include starch described in U.S. Pat. No. 2,322,037, starch derivatives described in Belgian Patent 625,451 and British Patent 981,198, etc .;
4-3643, polystyrene or polymethacrylate described in Swiss Patent 330,158, etc., polyacrylonitrile described in U.S. Pat. No. 3,079,257, U.S. Pat. No. 3,022,1
An organic matting agent such as polycarbonate described in No. 69 or the like can be used.

The shape of the matting agent may be either a fixed shape or an irregular shape, but a fixed and spherical shape is preferably used.
The size of the matting agent is represented by a diameter when the volume of the matting agent is converted into a sphere. In the present invention, the particle diameter of the matting agent indicates the diameter converted into a sphere.

The matting agent has an average particle size of 0.5 to 10 μm.
And more preferably 1.0 to 8.0.
μm. The variation coefficient of the particle size distribution is 5
0% or less, more preferably 40%
Or less, particularly preferably 30% or less. Here, the variation coefficient of the particle size distribution is a value represented by the following equation.

(Standard deviation of particle size / average value of particle size) × 100 The matting agent can be contained in any constituent layer. Further, a plurality of types of matting agents may be added.

When the hot silver light-sensitive material is a light-sensitive material for an image setter having an oscillation wavelength of 600 to 800 nm, a hydrazine compound is preferably contained in the light-sensitive material. Preferred hydrazine compounds include RD
23515 (November 1983, p. 346) and references cited therein, as well as U.S. Pat.
No. 4,269,929, 4,276,364
Nos. 4,278,748 and 4,385,108
No. 4,459,347 and 4,478,928
Nos. 4,560,638 and 4,686,167
Nos. 4,912,016 and 4,988,604
No. 4,994,365, No. 5,041,355
No. 5,104,769, British Patent 2,011,3
No. 91B, EP 217,310, EP 301,79
Nos. 9, 356, 898, and JP-A-60-179934.
No. 61-170733, No. 61-270744
No. 62-178246, No. 62-270948
Nos. 63-29751, 63-32538, 63-110407, 63-121838, and 6
3-129337, 63-223744, 63
-234244, 63-234245, 63-
No. 234246, No. 63-294552, No. 63-3
Nos. 06438 and 64-10233, JP-A-1-90
No. 439, No. 1-100530, No. 1-1095941
No. 1-105943, No. 1-276128, No. 1-280747, No. 1-283548, No. 1-2
No. 83549, No. 1-285940, No. 2-2541
No. 2-77057, No. 2-139538, No. 2
196234, 2-196235, 2-19
No. 8440, No. 2-198441, No. 2-19844
No. 2, 2-220042, 2-221953,
2-221954, 2-285342, 2-
No. 285343, No. 2-289843, No. 2-302
No. 750, No. 2-304550, No. 3-37642
No. 3-54549, No. 3-125134, No. 3
Nos. -184039, 3-240036, 3-24
No. 0037, No. 3-259240, No. 3-28003
No. 8, 3-282536, 4-51143, 4-56842, 4-84134, 2-230
No. 233, No. 4-96053, No. 4-216544
Nos. 5-45761, 5-45762, 5-
No. 45763, No. 5-45764, No. 5-45765
And Nos. 6-289524 and 9-160164.

In addition to the above compounds, compounds represented by “Chemical Formula 1” described in JP-B-6-77138 are specifically described.
Compounds described on pages 8 to 18 and compounds represented by formula (1) described in JP-B-6-93082, specifically, compounds 1 to 38 described on pages 8 to 18 of the same publication, 6-23
No. 049, compounds represented by formulas (4), (5) and (6), specifically, compounds 4-1 to 4-10 and 28 to 36 described on pages 25 to 26 of the same publication. Compounds 5-1 to 5-42 described on page 39, compounds 6-1 to 6-7 described on pages 39 to 40, and compounds represented by general formulas (1) and (2) described in JP-A-6-289520. And specifically, compounds 1-1 to 1-17 and 2 described on pages 5 to 7 of the same publication.
-1, a compound represented by (Chemical Formula 2) and (Chemical Formula 3) described in JP-A-6-313936, specifically,
Compounds described on page 9, compounds represented by (Chemical Formula 1) described in JP-A-6-313951, and specifically, compounds 3 to
Compounds described on page 5, compounds represented by general formula (I) described in JP-A-7-5610, specifically
Compounds I-1 to I-38 described on pages 10 to 10;
The compound represented by the general formula (II) described in No. 77783, specifically the compound II-
1 to II-102, compounds represented by formulas (H) and (Ha) described in JP-A-7-104426, and specifically, compound H-1 described on pages 8 to 15 of the same publication ~ H-
44 etc. can be used.

In the present invention, the halogenated antifoggant compound may be an isocyanate compound as described in JP-A-6-208193, and US Pat. No. 3,017,2.
No. 80, aziridine compounds as described in JP-A-9-5916, JP-A-10-186561, and 9-5
When used in combination with an epoxy compound described in JP-A No. 916 or the like, a further anti-fogging effect can be realized. When the carbodiimide compound described in US Pat. No. 3,100,704 is used in combination, it is the next most effective antifoggant compound.

Representative examples of the above compounds which can be used in combination with the halogenated antifoggant compound of the present invention are described below.

First, examples of the isocyanate compound include compounds represented by the following general formula (II).

Formula (II) O = C = NL- (N = C = O) _{v In the} formula, L is a linking group which is a residue of an alkyl group, an alkenyl group, an aryl group or an aralkyl group; v is 0, 1 or 2.

These isocyanate compounds have been found to increase the fog stability of the hot silver emulsion.

The aryl group represented by L in formula (II) may have a substituent, such as a halogen atom (Br, Cl, etc.), a hydroxyl group, an amino group, a carboxyl group, an alkyl group, Selected from alkoxy groups.

Examples of specific isocyanate compounds available from the manufacturer are shown below, but are not limited thereto. This includes aliphatic, aromatic and polymeric isocyanates.

IC-1 Desmodu
r) N100: manufactured by Mobay, aliphatic isocyanate IC-2 Desmodu N3300: manufactured by Mobay, aliphatic isocyanate IC-3 Mondur TD-80: manufactured by Mobay, aromatic isocyanate IC-4 Mondeux M : Mobay, Aromatic Isocyanate IC-5 Montdeux MRS: Mobay, Polymer Isocyanate IC-6 Desmodu W: Mobay, Aliphatic Isocyanate IC-7 Papi 27: Dow, Polymer Isocyanate IC-8 Isocyanate T1890: Huls (Hu
els), aliphatic isocyanate IC-9 octadecyl isocyanate: Aldrich, aliphatic isocyanate Next, the compound having an aziridine group that can be used in the present invention will be described. Any compound having an aziridine group and having a hardening action can be used arbitrarily, but in the practice of the present invention, the following specific compounds can be preferably used.

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Next, the epoxy hardener will be described. Any compound having an epoxy group and exhibiting a hardening effect can be used arbitrarily, but an epoxy compound having a hydroxyl group or an ether condensation is preferable. The following are specific examples of the compounds.

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[0084]

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[0085]

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[0086]

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[0087]

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[0088]

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[0089]

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The above compounds are almost commercially available and can be easily obtained. The compound having an epoxy group may be added by dissolving the compound in an organic solvent such as alcohol, acetone or toluene or water, or may be added as it is, or may be added to an interface such as dodecylbenzenesulfonate or nonylphenoxyalkylene oxide. You may add after dispersing using an activator.

In the present invention, carbodiimide compounds other than those described above can be used. Preferred carbodiimide compounds are represented by the following general formula (CI-1) or (CI-2)
It is shown by.

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In the formula, A is an aliphatic group (methyl, ethyl, i
-Propyl, butyl, i-butyl, t-butyl, allyl, crotyl, β-hydroxyethyl, methoxymethyl-β-bromoallyl, etc., aromatic groups (phenyl, tolyl, xylyl, naphthyl, chlorophenyl, bromophenyl, iodophenyl) Etc.), an alicyclic group (cyclohexyl, bornyl, menthyl, etc.) and a heterocyclic group (pyridyl, quinolyl, etc.).

R ₁₁ and R ₁₂ each represent a lower alkyl group (methyl, ethyl, propyl, i-propyl, butyl, etc.), and B and B ₁ (which may be the same or different)
Each represents an alkylene group, an arylene group or an aralkylene group (propylene, phenylene, tolylene, propylphenylene, etc.).

These disubstituted carbodiimides can be obtained by converting N, N'-disubstituted symmetric or asymmetric thioureas having at least one tertiary amino group from Berichte, V.
ol. 71, 1512-21, ibid., Vol. 73,4
Pp. 67-477, pp. 1114-1123, Vol.
75, 100-5, Annalen, vol. 56
0,222-231, Journal of Org
anic Chemistry, vol, 1024-6
As described on the page, it is obtained by treating with a desulfurizing agent such as an oxide of a heavy metal such as lead or mercury.

The following are representative compounds. Ni-propyl-N '-(4-dimethylaminophenyl) carbodiimide N-phenyl-N'-(4-dimethylaminophenyl)
Carbodiimide N, N'-di (4-dimethylaminophenyl) carbodiimide N, N'-di (4-dipropylaminotolyl) carbodiimide N-bornyl-N '-(4-dimethylaminophenyl)
Carbodiimide N-menthyl-N '-(4-dimethylaminophenyl)
Carbodiimide N- (β-bromoallyl) -N ′-(γ-dimethylaminophenyl) carbodiimide Nt-butyl-N ′-(γ-dimethylaminophenyl) carbodiimide N-cyclohexyl-N ′-(4-dimethylaminophenyl ) Carbodiimide Ni-propyl-N '-(γ-dimethylaminopropyl) carbodiimide N-methoxymethyl-N- (γ-dimethylaminopropyl) carbodiimide N, N'-di (γ-pyridyl) carbodiimide Tertiary of these N, N'-disubstituted carbodiimides having an amine can be used directly or in the presence of ethyl acetate, chloroform, benzene, toluene or a mixed solvent thereof with a suitable quaternizing agent such as methyl bromide, Ethyl bromide, methyl iodide, ethyl iodide, dimethyl sulfate, diethyl sulfate, By reacting with methyl p-toluenesulfonate, ethyl p-toluenesulfonate or the like, a quaternary ammonium salt can be obtained, whereby the solubility can be controlled. It may be added in the form of a quaternary salt.

Specific examples of the quaternized N, N'-disubstituted carbodiimide are described below. Ni-propyl-N'-
(4-dimethylaminophenyl) carbodiimide-ethyl-p-toluenesulfonate N-phenyl-N '-(4-dimethylaminophenyl)
Carbodiimide-ethyl-p-toluenesulfonate N, N'-di (4-dimethylaminophenyl) carbodiimide-monoethobromide N, N'-di (4-dipropylaminotolyl) carbodiimide-ethyl-p-toluenesulfonate N- Bornyl-N '-(4-dimethylaminophenyl)
Carbodiimide-methosulfate N-menthyl-N '-(4-dimethylaminophenyl)
Carbodiimide ethosulfate N- (β-bromoallyl) -N ′-(γ-dimethylaminophenyl) carbodiimide ethosulfate N- (t-butyl) -N ′-(γ-dimethylaminophenyl) carbodiimide ethyl-p- Toluenesulfonate N-cyclohexyl-N '-(4-dimethylaminophenyl) carbodiimide / ethyl-p-toluenesulfonate Ni-propyl-N'-(γ-dimethylaminopropyl) carbodiimide / ethobromide N-methoxymethyl-N- (Γ-dimethylaminopropyl) carbodiimide-ethyl-p-toluenesulfonate N, N′-di (γ-pyridyl) carbodiimide monomethosulfate Generally, an antifoggant compound such as an isocyanate or an epoxy compound is used per mole of silver. 0.00 It is used in an amount of 2 mol or more. Usually, 0.002 to 2 per mole of silver.
Moles, preferably in the range of from 0.003 to 0.3 moles of the compound.

The heat-sensitive material of the present invention includes, for example,
-159841, 60-14335, 63-
No. 231437, No. 63-259651, No. 63-3
04242, 63-15245, U.S. Pat.
39,414, 4,740,455, 4,74
1,966, 4,751,175, 4,83
Sensitizing dyes described in 5,096 can be used. Useful sensitizing dyes are described, for example, in the literature described or cited in RD17643, page 23, section IV-A (December 1978). 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.
5, US Patent No. 2,161,331, West German Patent 93
For simple merocyanines and helium neon laser light sources described in US Pat. No. 6,071, JP-A-5-11389, JP-A-50-62425 and JP-A-54-1872.
Nos. 6 and 51-102229, the merocyanines described in JP-A-7-287338, the LED light source and the infrared semiconductor laser light source are disclosed in JP-B-48-42172 and 51. No. 9609, No. 55-39818, JP-A-62-284343, and JP-A-2-105135.
Tricarbocyanines described in JP-A-90-132 and JP-A-60-80841; JP-A-59-192242;
Dicarbocyanines having a 4-quinoline nucleus described in General Formulas (IIIa) and (IIIb) of JP-67242 are advantageously selected. Further, the wavelength of the infrared laser light source is 750 n
m or more preferably 800 nm or more, in order to cope with a laser in such a wavelength range, Japanese Patent Application Laid-Open No.
Nos. 182639, 5-341432, 6-5
No. 2387, No. 3-10931, U.S. Pat.
Sensitizing dyes described in JP-A No. 1,866 and JP-A-7-13295 are preferably used.

These sensitizing dyes may be used alone.
Combinations of sensitizing dyes are often used, especially 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.

Examples of the surfactant used in the present invention include:
Any material such as anionic, cationic, betaine, nonionic, and fluorine can be used as appropriate. In particular,
JP-A-62-170950, U.S. Pat.
No. 04, etc .;
Fluorescent surfactants described in JP-A-244945 and JP-A-63-188135; polysiloxane surfactants described in U.S. Pat. No. 3,885,965;
Examples thereof include polyalkylene oxides and anionic surfactants described in No. 140 and the like, but other surfactants may be used.

Various additives include a photosensitive layer, a non-photosensitive layer,
Further, it may be added to any of the other constituent layers. In addition to the above, for example, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, a coating aid, and the like may be used in the heat-sensitive material of the present invention. These additives and the other additives mentioned above,
The compounds described in RD 17029, pages 9 to 15 (June, 1978) can be preferably used.

The heat-sensitive material of the present invention has at least one photosensitive layer on a support. Although only the photosensitive layer may be formed on the support, at least one photosensitive layer may be formed on the photosensitive layer.
Preferably, a non-photosensitive layer is formed.

In order to control the amount or wavelength distribution of light passing through the photosensitive layer, a filter dye layer on the same side as the photosensitive layer and / or an antihalation dye layer, a so-called backing layer, may be formed on the opposite side. Alternatively, a dye or a pigment may be contained in the photosensitive layer. As the dye to be used, any compound may be used as long as it has a desired absorption in a desired wavelength range, and examples thereof include JP-A-59-6481 and JP-A-59-6481.
No. 9-182436, U.S. Pat. No. 4,271,263,
No. 4,594,312, European Patent Publication 533,008
No. 652,473, JP-A-2-216140,
4-348339, 7-191432, 7-
Compounds described in 301890 and the like are preferred.

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

The light-sensitive layer according to the present invention may be composed of a plurality of layers, or the sensitivity may be a high-sensitive layer / low-sensitive layer or a low-sensitive layer / high-sensitive layer for adjusting the gradation.

It is preferable that all coating liquids used for coating the heat-sensitive material be filtered before coating. In that 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 hot silver sensitive material of the present invention is preferably applied by a pre-measurement coater. Generally, the coating process includes a portion for transferring the coating solution to the web (support) (hereinafter, referred to as an “application system”) and a portion for measuring the coating solution transferred to the web to a desired coating amount (hereinafter, “metering”). system"
The pre-metering type coater (pre-metering type coating method) means that the application system and the metering system are in charge of the same part. For example, it refers to die coating, slide coating, curtain coating and the like.

[0108]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto. Unless otherwise specified, “%” in the examples represents “% by mass”.

Example 1 <Preparation of photographic support> 8 W / m ² was applied to both sides of a 175 μm thick PET film colored blue at a concentration of 0.170.
-Corona discharge treatment was performed for minutes.

(Preparation of Photosensitive Silver Halide Emulsion A) Water 9
6. Ossein gelatin having an average molecular weight of 100,000 in 00 ml
5 g and 10 mg of potassium bromide were dissolved at 35 ° C., p
After adjusting to H3.0, an aqueous solution 37 containing 74 g of silver nitrate was used.
0 ml and an aqueous solution containing potassium bromide and potassium iodide in a molar ratio of (98/2) (equimolar to silver nitrate) and iridium chloride in an amount of 1 × 10 ⁻⁴ mol per mol of silver and pAg of 7.7
10 with controlled double jet method
It was added over a minute. Thereafter, 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene (stabilizer)
0.3 g was added and the pH was adjusted to 5 with sodium hydroxide to obtain cubic silver iodobromide grains having an average grain size of 0.06 μm, a grain size variation coefficient of 12%, and a [100] face ratio of 87%. Was.

This emulsion was subjected to coagulation sedimentation using a gelatin coagulant and desalting treatment, and then 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and the pAg to 7.5 to obtain photosensitive silver halide emulsion A.

(Preparation of sodium behenate solution) 340
34 g of behenic acid was dissolved at 65 ° C. in ml of isopropanol. Next, while stirring, a 0.25 mol / L aqueous sodium hydroxide solution was added so as to have a pH of 8.7 (about 400 ml of an aqueous sodium hydroxide solution was required). The aqueous sodium behenate solution was concentrated under reduced pressure to adjust the concentration of sodium behenate to 8.9%.

(Preparation of silver behenate) In a solution obtained by dissolving 30 g of ossein gelatin in 750 ml of distilled water,
A 94 mol / L silver nitrate solution was added, and the silver potential was increased to 400 m.
V. Into this, 374 ml of the above sodium behenate solution was added at a speed of 44.6 ml / min at a temperature of 78 ° C. using a controlled double jet method, and at the same time, an aqueous solution of 2.94 mol / L silver nitrate was added to silver. It was added so that the potential became 400 mV. The amounts of sodium behenate and silver nitrate used at the time of addition were 0.092 mol and 0.101 mol, respectively. After the addition is complete,
After stirring for a minute, the water-soluble salts were removed by ultrafiltration.

(Preparation of Photosensitive Emulsion B) To this silver behenate dispersion was added 0.01 mol of the silver halide emulsion A, and the mixture was further stirred with a butyl acetate solution of polyvinyl acetate (1.
100 g of 2%) was gradually added to form a floc of the dispersion, water was removed, and water was washed twice and water was removed. Then, polyvinyl butyral (average molecular weight: 3,000) was used as a binder. After adding 60 g of a 5% butyl acetate / i-propyl alcohol 1: 2 mixed solution with stirring, polyvinyl butyral (average molecular weight of 4) was obtained as a binder to the obtained mixture of silver behenate and silver halide. 000) and i-propyl alcohol. Thus, photosensitive emulsion B was obtained.

<Preparation of Coating Solution for Photosensitive Layer>
00g and 100g of methyl ethyl ketone while stirring.
The temperature was kept at 1 ° C. To this, 0.45 g of pyridinium hydrobromide perbromide (PHP) was added and stirred for 1 hour. Further, 3.25 ml of a 10% methanol solution of calcium bromide was added and stirred for 30 minutes. Next, a mixed solution of infrared sensitizing dye (IRD-1), 4-chloro-2-benzoylbenzoic acid and 5-methyl-2-mercaptobenzimidazole (supersensitizer) (mixing ratio 1: 250: 2).
0, 70% of a 0.1% methanol solution with a sensitizing dye), and the mixture is stirred for 1 hour. While keeping the temperature at 13 ° C., 130 g of polyvinyl butyral was added and dissolved sufficiently.
The following additives are added in order at minute intervals.

2-tribromomethylsulfonylquinoline (* 1) 4.0 g Reducing agent A-4 (* 2) 15 g Hardener Desmodu N3300 (10% MEK solution) 12 ml Infrared dye IRF-1 8 mg <Hotness Preparation of Material> The following layers were sequentially formed on a support, and samples of the present invention and comparative heat-sensitive materials were prepared. In addition, each drying was performed at 75 ° C. for 5 minutes.

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<Back side coating> A solution having the following composition was applied by an extrusion coating method so as to have a wet thickness of 80 μm.

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

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<Coating on photosensitive layer surface side> The photosensitive layer coating solution having the above composition was coated with an amount of silver of 2.0 g / m ² , polyvinyl butyral as a binder of 3.2 g / m ² , and the following surface protective layer. The coating width is 1 m and the coating width is 10 m / m by the extrusion coating method so that the coating liquid has a dry thickness of 2.1 μm.
Simultaneous multilayer coating with a coating length of about 1,000 m was performed at a speed of min.

The additive (* 1), the reducing agent and the hardener (* 2) were each adjusted to 10% with methyl ethyl ketone (MEK). Samples that were mixed in the line are indicated as added in Table 1. Samples 1 to 8 of the type shown in Table 1 were produced.

<Surface Protective Layer> Methyl ethyl ketone 175 ml methanol 15 ml cellulose acetate butyrate 8.0 g phthalazine 1.0 g 4-methylphthalic acid 0.72 g tetrachlorophthalic acid 0.22 g tetrachlorophthalic anhydride 0.5 g monodisperse silica ( (Average particle size: 4 μm) 1% based on the binder The following evaluation was performed for each sample.

<< Evaluation of Sensitometry >> The leading and trailing ends of the coated sample were cut into 3.5 cm × 15 cm, and exposed to a laser sensitometer equipped with a 810 nm diode. After processing (developing) at 15 ° C. for 15 seconds, the obtained image was evaluated using a densitometer. The result of the measurement was evaluated in terms of Dmin and sensitivity (the reciprocal of the ratio of the exposure amount giving a density higher than Dmin by 1.0).
Table 1 shows relative sensitivities with the sensitivity of 1 as 100.

<< Evaluation of Coating Unevenness >> The coating central portion of each sample was processed into a size of 35.6 × 43.2 cm, and was exposed to a laser equipped with an 810 nm diode so that the image density became 1.0. Heat treatment for 15 seconds (development)
The obtained images were visually evaluated according to the following criteria.

◎: There is no occurrence of coating unevenness. ：: There is slight scale-like unevenness, but there is no problem. Δ: There is scale-like unevenness, but it is practically acceptable. Evaluation >> Each of the coated samples was subjected to the same treatment as in the sensitometry, and then the obtained developed samples were visually evaluated in the following five steps.

5: No yellowish tinge, cool black tone 4: Slightly yellowish, but barely noticeable 3: Yellowish, but not practically problematic 2: Yellowish color is strong and poses a problem in practical use 1: Yellowishness is remarkably strong and is not suitable for practical use.

[0128]

[Table 1]

As is clear from Table 1, the sample of the present invention was superior in all evaluations to the comparative sample.

[0130]

According to the present invention, low fog, high sensitivity,
In addition, it is possible to stably provide a heat-developable photographic light-sensitive material capable of obtaining a cool black image.

Claims (3)

[Claims] 1. A photothermographic method comprising a support containing an organic silver salt, photosensitive silver halide particles and a reducing agent, and having at least one photosensitive layer (image forming layer) and at least one protective layer. In the method for producing a material, it is necessary to add at least two or more of a reducing agent, an antifoggant, a hardener, a color tone, a dye (dye), a surfactant, and a matting agent to a coating solution within 3 hours of coating. A method for producing a heat-developable photographic photosensitive material. 2. The method for producing a photothermographic material according to claim 1, wherein said protective layer is simultaneously coated on said photosensitive layer. 3. The method for producing a photothermographic material according to claim 1, wherein the photosensitive layer and the protective layer are simultaneously laminated by a pre-metering coater.