JPS5913014B2 - Sensitization method for compositions for heat-developable photosensitive materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for sensitizing compositions for heat-developable photosensitive materials.

Photography using silver halide has been the most widely used photographic method since it has superior photographic properties such as sensitivity and gradation compared to methods such as electrophotography and diazo photography. .

15 However, the silver halide photosensitive materials used in this silver halide photography method are developed with a developer after image exposure, and the resulting images are subject to discoloration and fading under normal room light. Several liquid treatments such as stopping, fixing, washing, or stabilization are performed to prevent the white areas (background) that have been generated or have not been developed from turning black20. Therefore, such processing is time-consuming and labor-intensive, and the handling of chemicals poses risks to the human body, contaminating the processing room, the bodies and clothing of workers, and furthermore, causing pollution if the processing liquid is discharged into rivers. There are many problems such as the occurrence of Therefore, high-sensitivity photographic materials using silver halide can be processed dryly without liquid processing, and the processed images are stable and the background is less likely to discolor under normal room light. There was a demand for a photosensitive material that could be processed using dry type 30 processing. For this reason, various efforts have been made up to now. For example, West German patent 11232
As described in No. 03 and No. 1174157, it is possible to develop by heating by adding 35% of a 3-pyrazolidone developing agent to a silver halide emulsion, and in this case, furthermore, in this case, moisture is removed during heating. A. Ku West German Patent No. 1175075 describes that the reaction is accelerated by the coexistence of a substance that provides .

Further, West German Patent No. 1003578 describes the coexistence of a silver halide fixing agent. However, with these techniques, it has not been possible to completely stabilize the silver halide itself remaining in the photosensitive material against light after it has been processed using a dry processing method. That is, the first three patent inventions do not describe fixing by dry processing, and in the last patent invention, since the developing agent (reducing agent) and fixing agent coexist, undesirable reactions occur during storage. It is expected that it will be difficult to put it into practical use. At present, the most successful material in the field of photosensitive materials that can form photographic images using such a dry processing method is the silver salt of an organic acid described in U.S. Pat. This is a heat-developable photosensitive material using a composition containing a reducing agent as an essential component.

In this photosensitive system, a method is used in which the silver halide remaining in the photosensitive material after development is not stabilized against light, but is allowed to change color due to light. It is effective. This is because the amount of silver halide used is small, and most of it consists of stable white or light-colored organic silver salts that do not easily darken the characters. However, since the color appears white or light-colored as a whole, such slight discoloration hardly bothers the human eye. This photosensitive material is stable at room temperature, but after image exposure it is usually heated at a temperature of 80°C or higher, preferably at 10°C.
When heated to 0° C. or higher, the organic silver salt oxidizing agent and reducing agent in the photosensitive layer cause a redox reaction by the catalytic action of the exposed silver halide present in the vicinity, producing silver.
As a result, the exposed portions of the photosensitive layer quickly turn black, creating a contrast with the unexposed portions (background) and forming an image. The present invention aims to improve the above-mentioned heat-developable photosensitive materials, and particularly relates to a method for sensitizing a composition for a photosensitive layer of a heat-developable photosensitive material.

Conventionally, in liquid-processed (wet) silver halide photosensitive materials, trace amounts of physically unstable sulfur-containing compounds, selenium-containing compounds, or tellurium-containing compounds are included in the composition of the photosensitive layer. Sensitizing compositions is often referred to as, for example, chemical sensitization. These techniques are described in
'AphicPrOcessl 3rd edition (1966 Ma
published by Cmillan), pages 114 to 116, and "PhOtOgraphicEmulsiOnChe"
mistry” (published by FOcalPress in 1966), pp. 83-98, U.S. Patent No. 1,574,944,
No. 1623499, No. 2278947, No. 2399
No. 083, No. 2410689, No. 2440206,
No. 2449153, No. 3189458, No. 3297
No. 446, No. 3297447, No. 3501313,
British Patent No. 1129356, West German Patent No. 971436, West German Patent No. 1422869, West German Patent No. 1572260 and West German Patent No. 20
55103, French Patent No. 1307754, French Patent No. 2059
No. 245, No. 2064204, Perky National Patent No. 624
013 and Japanese Patent Application Laid-Open No. 47-5887. It would be extremely desirable for engineers and researchers in the art if this wet-type silver halide photosensitive material sensitization technique could be applied to the above-mentioned heat-developable photosensitive materials. Therefore, an object of the present invention is to provide a method for sensitizing compositions for heat-developable photosensitive materials.

More specifically, it is an object of the present invention to provide a method for sensitizing a composition for a heat-developable photosensitive material using a sulfur-containing compound. The present inventors have been conducting research on heat-developable photosensitive materials for many years, and in recent years in particular, as a result of their research into the compatibility of the two sensitizing means described above, they have generally found that at least wet halogen It has become clear that the sensitization method for silveride light-sensitive materials is not applicable to heat-developable light-sensitive materials.

For example, many experiments have shown that it is not possible to sensitize the photosensitive layer of a heat-developable photosensitive material using a gold sensitization method using a gold compound or a sensitization method using a palladium compound, which are commonly known as sensitization methods for wet photosensitive materials. It was empty. This is because the main components that make up the image in both are completely different, such as silver halide or organic silver salt, and the developing method is also a processing solution containing many components. It cannot but be interpreted that this is because there is a difference between this and the case where development is performed simply by heating. Although this is a simple consideration, it is related to the fundamental difference between the two photosensitive systems. As mentioned above, the present inventors developed a compound having a sulfur-containing compound and one H-C-N unit, which is known as a sensitizer for wet-type silver halide photographic light-sensitive materials, which is generally not applicable. It was discovered that a composition for a heat-developable photosensitive material can be sensitized by using the compound in combination with a preheating treatment. The present invention was based on the discovery that fog was reduced by using a synthetic silver halide.

That is, the present invention provides at least (a) an organic silver salt and (b)
(c) -CON before coating a composition for a heat-developable photosensitive material containing a photosensitive silver halide formed by decomposing an N-halogeno compound in the presence of (a) an organic silver salt;
This is a method for sensitizing a composition for a photothermographic material, which is characterized by heating in the presence of a compound having one H unit and (d) a sulfur-containing organic compound. As mentioned above, the sensitization method of the present invention targets a composition for a heat-developable photosensitive material comprising at least (a) an organic silver salt and (b) a photosensitive silver halide.

First, this composition will be explained. The organic silver salt of component (a) used in the present invention is a colorless, white or light-colored silver salt, preferably at a temperature of 80°C or higher, preferably 100°C or higher in the presence of photosensitive silver halide. When heated, it reacts with a reducing agent to produce silver (image).

Such organic silver salts are silver salts of organic compounds having imino, mercapto or thione groups or carboxyl groups, and specific examples thereof include the following. (1) Examples of silver salts of organic compounds having imino groups: benzotriazole silver, nitrobenzotriazole silver, alkyl-substituted benzotriazole silver such as methylbenzotriazole silver, e.g. bromobenzotriazole silver, chlorobenzotriazole silver, etc. halogen-substituted benzotriazole silver, such as carboimide-substituted benzotriazole silver, benzimidazole silver, substituted benzimidazole silver such as 5-chlorobenzimidazole silver and 5-nitrobenzimidazole silver, etc., dipicrylamine silver, carbazole Silver, saccharin silver, phthalazinone silver, substituted phthalazinone silver, phthalimide silver salts, pyrrolidone silver, tetrazole silver, imidazole silver, N-(benzoic acid-sulfonic acid mono(2)-imide) silver, N-(4-nitro Benzoic acid-sulfonic acid mono(2)
(2) Mercapto Silver salt of compound having group or thione group: JP-A-48-28
Silver S-alkyl-thioglycolates in which the alkyl group contains 12 to 22 carbon atoms, 2-alkylthio-5-(carboxilademethylthio)-1,3,4-thiodiazole, as described in No. 221 or the silver salt of 3-(carboxilademethylthio)-1,2,4-triazole, the silver salt of a thione compound as described in U.S. Pat. No. 3,785,830, where the thione compound is It is represented by a general formula.

) In the above formula, R represents the atomic group necessary to complete the 5-membered heterocyclic ring, Z represents an alkylene group having 1 to 10 carbon atoms), S- as described in U.S. Pat. No. 3,549,379 Silver 2-aminophenylthiosulfate, Silver 2-mercaptobenzoxazole, Silver mercaptooxadiazole, Silver 2-mercaptobenzothiazole, 2-(S-
ethylthioglycolamide) benzothiazole silver salt, 2-mercaptobenzimidazole silver, 3-mercapto-4-phenyl-1,2●4-triazole silver salt,
Silver salts of dithiocarboxylic acids such as silver salts of mercaptotriazine, silver salts of 2-mercapto-5-aminothiadiazole, silver salts of 1-phenyl-5-mercaptotetrazole, silver salts of dithioacetic acid, silver thioamides, 5- Silver salts of thiopyridine such as silver salt of carbethoxy-1-methyl-2-phenyl-4-thiopyridine, silver salt of dithiohydroxybenzole, silver diethyldithiocarbamate, etc.
3) Organic silver salts having a carboxyl group: (a) Silver salts of aliphatic carboxylic acids: silver caprate, silver laurate, silver myristate, silver valmicate, silver stearate, silver behenate, silver malate , silver fumarate, silver tartrate, silver furoate, silver linoleate, silver oleate, silver hydroxystearate, silver adipate, silver sebacylate, silver succinate, silver acetate, silver butyrate, silver camphorate, undecylenic acid. Silver, silver lignocerate, silver arachidonate, silver erucate, silver oxalate, 1
Silver 0,12,14-octadecatrienoate, silver salts of aliphatic carboxylic acids with thioether groups, such as those described in U.S. Pat. No. 3,330,663, silver propionate, silver valerate, silver caproate, silver Silver furylate, silver tertiary butyl hydroperoxide, silver malonate, silver glutarate, silver pimelate, silver azelate, silver chloroacetate, silver trichloroacetate, silver fluoroacetate, silver iodoacetate, silver sarcosine, aniline acetate Silver, silver mandelate, silver hippurate, naphthalene silver acetate, silver creatate, silver lactate, α
silver mono- or β-mercaptopropionate, silver levulinate,
For example, L-alanine, γ-aminobutyric acid, ε-aminocaproic acid, L-aspartic acid, L-glutamic acid, L-
Silver salts of amino acids such as leucine, silver tricarballylate, silver nitrilotriacetate, silver citrate, silver ethylenediaminetetraacetate, silver acrylate, silver methacrylate, silver crotonate, silver zorbate, silver itaconate, etc. b) Silver aromatic carboxylate and others: silver benzoate, silver 3,5-dihydroxybenzoate, silver o-methylbenzoate, silver Mt-methylbenzoate, silver p-methylbenzoate, 2,4-dichlorobenzoic acid Silver, silver acetamidobenzoate, silver p-phenylbenzoate, silver gallate, silver tannate, silver phthalate, silver terephthalate, silver salicinoleate, silver phenyl acetate, silver pyromellistate, 4'-n-octadecyloxydiph Silver salt of enyl-4-carboxylic acid, silver m-nitrobenzoate, o
-Silver aminobenzoate, silver furoate, silver p-hexoxybenzoate, silver octadecoxybenzoate, silver cinnamate, p-
Silver methoxycinnamate, silver furoate, silver p-nitrophenyl acetate, silver nicotinate, silver isonicotinate, silver picolinate, silver pyridine-2,3-dicarboxylate, (4) Silver sulfonate: silver ethanesulfonate, 1- Silver propanesulfonate, silver 1-butanesulfonate, silver 1-pentanesulfonate, silver allylsulfonate, silver benzenesulfonate, silver 1-n-butylnaphthalene-4-sulfonate, naphthalene-1.5 -Silver disulfonate, silver α- or β-naphthalenesulfonate, silver p-toluenesulfonate, silver toluene-3,4-disulfonate, p-
Silver nitrobenzenesulfonate, silver diphenylaminesulfonate, silver 2-naphthol-3,6-disulfonate, silver anthraquinone-β-sulfonate, silver 2-amino-8-naphthol-6-sulfonate, p- Silver styrene sulfonate, etc., (5) Silver sulfinate: Silver p-toluenesulfinate, Silver p-acetaminobenzenesulfinate, Silver benzenesulfinate, etc., (6) Silver organic phosphate: Silver phenyl phosphate. , silver p-nitrophenyl phosphate, silver β-glycerophosphate, silver 1-naphthyl phosphate, silver adenosine-5'-3-phosphate, etc. (7) Silver salts of polymeric compounds: silver polyacrylate, polyvinyl Silver salts of hydrogen phthalate, silver polystyrene sulfonate, etc. (8) Other silver salts: 4-hydroxy 6-methyl-1.3.3a.
7-Silver salt of tetrazaindene, 5-Methyl-J-metallic acid 1, 2, 3, 4, 6-silver salt of pentazaindene,
silver salts of tetrazaindene as described in UK Patent No. 1,230,642, metallized amino alcohols as described in UK Patent No. 1,346,596, US Pat.
794496, silver 5-nitrosalicylaldoxime, silver 5-chlorosalicylaldoxime, silver barbiturate, silver picrate, silver rosinate, silver indophenol, silver barbiturate. , cyclopentadiene silver complex salt, pyridine silver complex salt, cyclopentapolyene silver complex salt, N-vinylcarbazole silver complex salt, o-sulfobenzimide silver salt, etc. Also, if necessary, non-silver salts such as titanium oxide, zinc oxide, gold laurate, etc. Oxidizing agents such as gold carboxylates such as gold stearate and gold behenate can also be used in combination with the above-mentioned organic silver salts.

Among the above organic silver salts, organic silver salts that are relatively stable to light are suitable, and silver salts of aliphatic carboxylic acids having 10 or more carbon atoms are particularly preferred.

There are various methods for preparing such organic silver salts, and the simplest method, as described in U.S. Pat. This is a method for preparing an organic silver salt by mixing a solution containing a forming agent or its salt and an aqueous solution of a water-soluble silver salt such as silver nitrate.

Furthermore, as described in US Pat. No. 3,839,049, it is also possible to mix a colloidal dispersion of an ammonium salt or alkali metal salt of an organic silver salt forming agent with an aqueous solution of a water-soluble silver salt such as silver nitrate.

In a similar method, instead of an aqueous solution of a water-soluble silver salt such as silver nitrate, an aqueous solution of a silver complex salt such as a silver ammine complex salt or a solution of these silver complex salts in a water-miscible solvent can also be used. Another method is US Pat. No. 3,458,544.
There is a method as described in No. 4. That is, it is a method of preparing organic carboxylic acid silver by mixing an oil-soluble solution, such as a benzene solution, which is difficult to mix with water, in which an organic carboxylic acid is dissolved, and an aqueous solution of a silver complex salt. Preferably, before mixing the aqueous solution of the silver complex salt, water is added to the oily solution to form an emulsion. Similar methods can be applied to other organic silver salts. A method similar to this, but in which the resulting organic silver salt is more stable against heat and light, is described in Japanese Patent Publication No. 30270/1983. this is,
This method uses a solution of a silver compound without using an alkali, such as a simple aqueous solution of silver nitrate, instead of a silver complex salt. According to this method, benzotriazole silver and the like can be obtained in high yield. Another method for preparing organic silver salts is the method described in West German Patent Publication No. 2402906. This method is preferable because the heat-developable photosensitive material using the organic silver salt obtained thereby does not cause much thermal fogging. That is, this involves combining an aqueous solution of an alkali metal salt or ammonium salt of a water-soluble organic silver salt forming agent with an oil (e.g., benzene, toluene, cyclohexane, pentane, hexane, etc.).
Emulsions of carboxylic acid esters such as acetate esters, phosphate esters, oils such as castor oil, etc.) and silver salts (silver nitrate, etc.) or silver complex salts that are more easily soluble than organic silver salts are mixed, preferably as an aqueous solution, to form an organic This is a method for preparing silver salts. As an alternative to this method, an aqueous alkaline solution and an oil-soluble solution of an organic silver salt forming agent (for example, a toluene solution) are mixed and emulsified,
An organic silver salt can also be prepared by mixing this with preferably an aqueous solution of a readily soluble silver salt such as silver nitrate or a silver complex salt such as a silver ammine complex salt. The oils used to prepare the above-mentioned oily solutions generally include the following: (
1) Phosphate esters: For example, tricresyl phosphate,
Tributyl phosphate, monooctyl dibutyl phosphate, etc.
(2) Phthalate esters: For example, diethyl phthalate, dibutyl phthalate, dimethyl phthalate, dioctyl phthalate, dimethoxyethyl phthalate, etc. (3) Carboxylic acid esters: For example, amyl acetate, isopropyl acetate, isoamyl acetate , acetate esters such as ethyl acetate, 2-ethylbutyl acetate, butyl acetate, propyl acetate;
Sebacic acid esters such as dioctyl sebacate, dibutyl sebacate, diethyl sebacate; succinic acid esters such as diethyl succinate; formic acid esters such as ethyl formate, propyl formate, butyl formate, amyl formate; Valeric acid esters such as ethyl valerate; Tartaric acid esters such as diethyl tartrate; Butyric acid esters such as methyl butyrate, ethyl butyrate, butyl butyrate, and isoamyl butyrate; Adipate esters; (4) Castor oil, cottonseed oil, linseed oil, Oils such as camellia oil: (5) Aromatic hydrocarbons such as benzene, toluene, and xylene; (6) Aliphatic hydrocarbons such as pentane, hexane, and heptane; (7) cyclic hydrocarbons such as cyclohexane; and silver complex salts. Preferably, alkali-soluble silver complex salts having a higher dissociation constant than organic silver salts are used, such as silver ammine complex salts, silver methylamine complex salts, and silver ethylamine complex salts. In addition to water, polar solvents such as dimethyl sulfoxide, dimethyl formamide, acetonitrile, and the like can also be used as solutions of silver salts such as silver nitrate. Further, as described in West German Patent Publication No. 2401159, ultrasonic waves can be applied during the preparation of organic silver salts. In particular, when emulsifying water and oil, applying ultrasonic waves makes emulsification easier. Further, a surfactant can also be used for purposes such as adjusting the particle size of the organic silver salt obtained during preparation of the organic silver salt. Furthermore, an organic silver salt may be prepared in the coexistence of a polymer. A particular method involves the use of a non-aqueous solution of an organic carboxylic acid and a heavy metal salt of trifluoroacetate or tetrafluoroborate in the presence of a polymer such as polyvinyl acetal, as described for example in U.S. Pat. No. 3,700,458. A method is known in which a heavy metal salt, such as a silver salt, of an organic carboxylic acid is prepared by mixing two organic carboxylic acids. Also, JP-A-49-13224
No. 51-22430 and West German Patent Publication No. 2322
As described in No. 096, when preparing an organic silver salt, by coexisting metal salts or metal complexes such as chromium, mercury, and lead compounds, the particle morphology, particle size, and, for example, thermal fogging of the organic silver salt can be improved. It is also possible to change photographic properties such as , photostability, and sensitivity.

In addition to the above-mentioned chromium, mercury, and lead, cobalt, manganese, nickel, and iron have also been confirmed to be effective metals. The method for using these metal-containing compounds is to mix a solution of a silver salt-forming organic compound, a mixed solution or dispersion of a metal-containing compound, and an aqueous solution of an easily soluble silver salt such as silver nitrate or an aqueous solution of a silver complex salt such as a silver ammine complex salt. You may. Alternatively, three liquids may be mixed: a solution or dispersion of a metal-containing compound, an aqueous solution of a silver salt or silver complex salt, and a solution or dispersion of a silver salt-forming organic compound. Furthermore, a method of mixing a solution or dispersion of a silver salt-forming organic compound and a mixed solution or dispersion of a silver salt or silver complex salt and a metal-containing compound is also preferred. The amount of metal-containing compound preferably ranges from about 10@3 to about 10@-1 mole per mole of organic silver salt, and from about 10@-5 mole to 10@-2 mole per mole of silver halide. The particle size of the organic silver salt thus prepared has a major axis of about 10 microns to about 0.01 microns, preferably about 5 microns to about 0.1 microns. The photosensitive silver halide of component (b) used in the present invention is:
Silver chloride, silver bromide, silver iodide, silver chlorobromoiodide, silver chlorobromide, silver chloroiodide, silver iodobromide, or a mixture thereof.

The amount used is about 0.001 mol to about 0 per mol of organic silver salt.
．． 2 moles, preferably in the range of about 0.006 moles to about 0.06 moles. The photosensitive silver halide may be of coarse grain or fine grain, but fine grain is preferable. The preferred grain size of the silver halide is a major axis of about 0.5 micron to about 0.005 micron, preferably about 0.3 micron to about 0.02 micron. When the grain size of photosensitive silver halide is too small, the efficiency of sensitization according to the present invention, which will be described later, becomes low, and when the grain size is too large (a
Since contact between the organic silver salt (a) and the photosensitive silver halide (b) becomes poor, the value must be kept within the above range as much as possible.

This grain size is determined in the preparation of photosensitive silver halide by, for example, the reaction temperature, the concentration of the solution or dispersion of the reactants, the rate of addition of the reactants, the stirring speed of the reaction mixture, the type of solvent, the type of organic silver salt, It can be adjusted by changing the type of halogen compound. The silver halide used in the present invention can also be prepared almost simultaneously with the production of the organic silver salt, as described, for example, in JP-A-50-17216.

To illustrate a specific method, for example, a silver salt such as silver nitrate or a silver complex salt is added to a mixed solution or dispersion of the organic silver salt-forming compound or its salt in which a photosensitive silver halide-forming component (described later) is coexisting. When mixing solutions or mixing a solution or dispersion of an organic silver salt-forming compound or its salt with a silver salt solution such as silver nitrate or a silver complex salt, a solution of a photosensitive silver halide-forming component is also mixed at the same time. In this way, photosensitive silver halide is also formed together with the organic silver salt. In addition, photosensitive... silver halide forming components (
It is also possible to form a photosensitive silver halide in a part of the organic silver salt by reacting with a compound (described later). It is described in US Pat. No. 3,457,075 that the silver halide thus formed is in effective contact with an organic silver salt and exhibits a favorable effect. Silver halide-forming components particularly suitable for the present invention are N-halogen compounds.

This is because when an N-halogeno compound is used, fog generated during thermal development is extremely reduced. Representative N-halogeno compounds particularly suitable for the present invention include compounds represented by the following general formulas (1) and ().

In the above general formulas (1) and (), X is Cl, . Br
and I are shown.

Z represents an atomic group necessary to form a 4- to 8-membered ring. Preferred atomic groups are hydrogen atoms, carbon atoms, nitrogen atoms, and oxygen atoms. Furthermore, this 4-membered ring to 8-membered ring may be condensed with other rings. Specific examples of the 5-membered ring or 6-membered ring include a pyrrole ring, pyrroline ring, pyrrolidine ring, imidaline ring, imidazolidine ring, pyrazoline ring, oxazolidine ring, piperidine ring, oxazine ring, piperazine ring, and indoline ring. .

Further, z may form a 4- to 8-membered lactam. Further, Z may form a hydantoin ring, a cyanuric ring, a hexahydrotriazine ring, an indoline ring, or the like. Furthermore, this ring may have a substituent such as an alkyl group, an aryl group, an alkoxy group, a halogen atom, or oxygen (=0).

The above alkyl group is, for example, methyl, ethyl, propyl,
Those having 1 to 12 carbon atoms such as isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, 2-ethylhexyl, octyl, nonyl, decyl, and dodecyl are preferred, and those having 1 to 8 carbon atoms are particularly preferred. Aryl groups include unsubstituted and substituted groups (for example, methyl,
C1-C4 alkyl groups such as ethyl, propyl, isopropyl, butyl, t-butyl, e.g. chlorine, bromine,
A halogen atom such as iodine is preferred. ), phenyl groups, naphthyl groups, and the like are preferred. Examples of alkoxy groups include 1 to 1 carbon atoms, such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy, pentoxy, hexoxy, octoxy, and dodecyloxy.
2 alkoxy groups are preferred, and those having 1 to 8 carbon atoms are particularly preferred. A represents a carbonyl group or a sulfonyl group. R1 and R2 represent a hydrogen atom, an alkyl group, an aryl group, or an alkoxy group, and the alkyl group and alkoxy group have 1 to 12 carbon atoms as described above.
Those with numbers 1 to 8 are particularly preferred. Preferred examples of the aryl group include the aforementioned unsubstituted or substituted phenyl and naphthyl groups. Halogenated melamines are also suitable N-halogen compounds for the present invention.

Specific examples of N-halogeno compounds preferred for the present invention are shown below.

1N-prom succinimide 2N-promtetrafluorosuccinimide 3N-bromphthalimide 4N-promglutarimide 5) 1-bromo-3,5,5-trimethyl-2,4-
Imidazolidinedione (6) 1,3-dibrome-5.
5-dimethyl-2,4-imidazolidinedione (7)N
-merdiprom-5,5-diethylbarbituric acid (8
) N-N'-dipromvalpituric acid (9) N-bromoisocyanuric acid 00 N-bromoacetamide (self) N-bromochloroacetamide 02) N-bromotrifluoroacetamide 03) N-
Bromoacetanilide 04) N-bromobenzenesulfonylanilide 05) N-bromobenzamide 06) N
- Bromobenzenesulfonylamide (L7) N-bromo-N-benzenesulfonylbenze.

``χ'.'. Rare 2 (L9) N-Chlorsuccinimide (20) N-Iodosuccinimide Co., Ltd. Trichloroisocyanuric acid (22) N-Chlorphthalimide (2'3) 1,3-dichloro-5・5-dimethyl-2
・4-imidazolidinedione (24) 3-chloro-5
・5-dimethyl-2,4-imidazolidinedione (25
) 1,3-diiodo-5,5-dimethyl-2,4-imidazolidinedione C26) Trichlormelamine Co., Ltd. Tribromomelamine (28) N-bromocyclohexane dicarbonimide (29) 1-Prom-3,5. 5-triethyl-2.
4-Imidazolidinedione C3ll-bromo-3-ethyl-5,5-dimethyl-2,4-imidazolidinedione (301,3-dibrom-5,5-diethyl-2,4-
imidazolidinedione C32) N-N-dibrome-5.
5-dimethylbarbituric acid (33) N-N-dibromo-5-ethyl-5-methylbarbituric acid (34)
N-N-dibromo-5-ethyl-5-phenylbarbituric acid G35) N-N-dibromoisocyanuric acid (36
) N-bromobromoacetamide C37) N-bromonaphthamide (to) N-bromohydroxybenzamide C39) N-
Bromocarboxybenzamide (4IN-bromotoluenesulfonamide (41) N-bromo-N-toluenesulfonyltoluenesulfonylamide (c) N-promusactucalin (43N-promucaprolactam (44) N-bromobutyrolactam (45) N- Promvalerolactam (46) N-bromoproviolactam (47) N-promooxazolinone Two or more of these N-halogeno compounds can also be used in combination.

The N-halogeno compound and the organic silver salt can be mixed in any form.

The organic silver salt and the N-halogen compound are mixed by adding the N-halogeno compound to the organic silver salt dispersed in a suitable solvent such as ethanol, methanol, isopropanol, toluene, benzene, cyclohexane, water, or isoamyl acetate. This is preferred because the compounds come into contact uniformly. Also preferred is a method in which an N-halogeno compound is added to an organic silver salt dispersed in a polymer solution and mixed. In the present invention, alcohol has been found to be particularly effective as a compound that helps generate halogen ions from N-halogeno compounds.

Alcohol here is alcohol in a broad sense.

Primary alcohols or secondary alcohols are particularly preferred for the present invention. Furthermore, alcohols that are liquid at low temperatures (about 30° C.) are preferred.

Particularly alcohols having 8 or fewer carbon atoms are suitable for the present invention. The alcohol of the present invention may contain atoms other than carbon atoms and hydrogen atoms, such as nitrogen atoms and oxygen atoms.

Preferred alcohols for the present invention include, for example, methanol, ethanol, n-propanol, isoprobanol, 1-butanol, 1-heptanol, 1-octanol, β-phenylethyl alcohol, furfuryl alcohol, pyridyl carbinol, and 2-octanol. ,α−
Included are phenylethyl alcohol, pyridylethyl alcohol, cyclohexanol, allyl alcohol, benzyl alcohol, isobutyl alcohol, Sec-butyl alcohol, crotyl alcohol, cyclopentanol, and the like.

Two or more types of alcohols may be used in combination.

Also, alcohol may coexist with a solvent other than water or alcohol. The ratio of N-halogeno compound to alcohol can vary within a wide range.

In general, the N-halogeno compound/alcohol (molar ratio) can vary from about 1 to 106, preferably from 10 to 104.

The N-halogeno compound, alcohol and organic silver salt can be mixed in any form.

Ethanol, methanol, isopropanol, Sec-
The N-halogeno compound can also be dispersed in an organic silver salt dispersed in an alcohol such as butyl alcohol or 2-octanol.

The N-halogeno compound can also be dispersed by adding the N-halogeno compound and alcohol to an organic silver salt dispersed in a solvent other than alcohol such as toluene, benzene, cyclohexane, or isoamyl acetate.

In this case, the N-halogeno compound and the alcohol can be added at the same time, or either one can be added first. Preferably, an organic silver salt dispersed in a polymer solution, an N-halogeno compound, and an alcohol are mixed.
When the polymer is in an alcohol solution, there is no need to add alcohol. The three components (organic silver salt, alcohol, and N-halogeno compound) may be mixed in any order.

Additionally, the addition rate can be freely selected. It is also possible to add the N-halogeno compound in portions. The temperature at which the N-halogeno compound is decomposed may be any temperature. A high temperature is preferable because it accelerates the decomposition of the N-halogeno compound, but problems such as rapid evaporation of the solvent and solidification of the organic silver salt arise, so appropriate measures must be taken. Generally, it is preferable to decompose the N-halogeno compound at 80°C or lower. Although the lower limit of the temperature is not particularly limited, it is generally preferable to decompose the N-halogeno compound at 0°C or higher.

The above-mentioned composition for a heat-developable photosensitive material comprising at least (a) an organic silver salt and (b) a photosensitive silver halide is one of the most characteristic components in the present invention, which is used for sensitization. As a compound having a certain -C-N unit, a compound represented by the following general formula is preferable, and a compound containing no sulfur atom is particularly preferable.

Here, Z represents an atomic group necessary to form a 4- to 8-membered ring.

Furthermore, this 4- to 8-membered ring may be fused with other rings. Specific examples of the 5-membered ring or 6-membered ring include a pyrrole ring, a pyrroline ring, a pyrrolidine ring, an imidazoline ring,
Examples include an imidazolidine ring, a pyrazoline ring, a pyrazolidine ring, a piperidine ring, an oxazine ring, a piperazine ring, a hydantoin ring, a cyanuric ring, a hexahydrotriazine ring, an indoline ring, and an oxazolidine ring.

Further, Z may form a 4- to 8-membered lactam ring. Furthermore, this ring may have a substituent such as an alkyl group, an aryl group, an alkoxy group, or oxygen (-0).
The above alkyl group is, for example, methyl, ethyl, propyl,
Those having 1 to 18 carbon atoms such as isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, 2-ethylhexyl, octyl, nonyl, decyl, and dodecyl are preferred, and those having 1 to 8 carbon atoms are particularly preferred. Aryl groups include unsubstituted and substituted groups (for example, methyl,
Alkyl groups having 1 to 4 carbon atoms such as ethyl, propyl, isopropyl, butyl, t-butyl, e.g. chlorine, bromine,
A halogen atom such as iodine is preferred. ), phenyl groups, naphthyl groups, and the like are preferred. Examples of alkoxy groups include 1 to 1 carbon atoms, such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, t-butoxy, pentoxy, hexoxy, octoxy, and dodecyloxy.
2 alkoxy groups are preferred, and those having 1 to 8 carbon atoms are particularly preferred. Furthermore, lactam compounds having a 4- to 8-membered ring are particularly preferred in the present invention. R1 and R2 represent a hydrogen atom, an alkyl group, an aryl group, or an alkoxy group, and R3 and R4 represent an aryl group or an alkyl group. As the alkyl group and alkoxy group, those having 1 to 18 carbon atoms as described above are preferable, and those having 1 to 8 carbon atoms are particularly preferable. Preferred examples of the aryl group include the aforementioned unsubstituted or substituted phenyl and naphthyl groups.
Further, R1 and R2 may have a substituent such as a carboxyl group. In the present invention, compounds represented by the above general formula () are particularly preferred.

Specific examples of the compound represented by the above general formula used in the present invention include the following.

1) Formamide 2) Formethylamide 3) Formallylamide 4) Acetamide 5 Acetomethylamide 6 Acetoethylamide 7 Propylamide 8 Butylamide 9 N-Methylbutyramide (Substitute) Hexylamide (11) Dodecylamide (Substitute) N-Methyl Dodecylamide (auto) Tetradecanilamide (auto) Formanilide 05) Acetanilide (sub) Benzamide (5) Dipenzamide (O) Benzanilide (11) α-Benzamide Isobutyric acid (To) ε-Benzamide Caproic acid (Company) Benzoylaspartic acid Succinimide Co., Ltd. (branch) Phthalimide Co., Ltd. Glutarimide C25) 3,5,5-trimethyl-2,4-imidazolidinedione (2e5,5-dimethyl-2,4-imidazolidinedione C!f) 5・5-diethylbarbituric acid (branch) Barbiturates Ilicyanuric acid (to) Phthalazone (b) Melamine (1) Naphthamide (to) Hydroxybenzamide (to) Satucalin (to) ε-Caprolactam (to) β-propio Lactam (Y) γ-Valerolactam (Y) δ-Valerolactam (Y) Hebutlactam (4I1-Phenylurazole (401-Phenyl-2-Methylurazole (Ha) Quinazoline (Ha) Methylquinazoline (Ha) Octylamide Various sulfur-containing organic compounds can be used in the present invention.

Preferred sulfur-containing organic compounds include the following.
(1) An organic compound having one -CS-NRl unit in the molecule.

(In the unit formula, R1 represents a hydrogen atom or a carbon-containing substituent having 12 or less carbon atoms.

Examples of such substituents constituting suitable compounds include substituted or unsubstituted alkyl groups such as methyl, ethyl, propyl, t-butyl, carboxymethyl, carboxyethyl, and phenylmethyl; allyl groups; Alkenyl groups such as phenyl, tolyl and carboxyphenyl; substituted or unsubstituted aryl groups such as acetyl and propionyl; and acyl groups such as acetyl and propionyl.
) (11) Specific example of organic compound (7) Compound R2-CS-NRlR3 represented by the following general formula [wherein R2 represents a carbon-containing substituent having 24 or less carbon atoms].

This substituent may contain a hydrogen atom, a nitrogen atom, an oxygen atom, a sulfur atom, and the like. Examples of R2 to constitute a suitable compound include those represented by the following general formula. (In the above general formulas (111) to (114), SR4sR5NR6lR7sR8sR9vRlOlR
ll, Rl2, Rl3, and Rl4 are synonymous with R1.

n represents an integer from 1 to 3. ) (115) MS- (In the formula, M represents a hydrogen atom or an alkali metal.

) R3 has the same meaning as R1.

] In the case of the compound represented by the general formula (11), it is preferable that at least one hydrogen atom is bonded to an element adjacent to one CS unit.

Specific examples of the compound represented by general formula (11) are as follows.

(12) Other specific examples of organic compound (1) A compound represented by the following general formula [wherein Z represents an atomic group necessary to form a 5- or 6-membered heterocyclic compound.

Atoms of this atomic group include atoms such as carbon, nitrogen, sulfur, oxygen, and selenium. Heterocycles composed of these atomic groups include oxazolidine rings, thiazolidine rings, imidazolidine rings, iso-oxiazolidine rings, pyrazolidine rings, isothiazolidine rings, and tetrahydrotriazole rings, which constitute preferred compounds. do. Particularly preferred are compounds in which an oxo group or thioxo group is further added to these heterocycles. Specific examples of particularly preferred nuclei include rhodanine nucleus, thiohydantoin nucleus, thiourazole nucleus, dithiourazole nucleus, 2-thio-2.4
-Oxazolidinedione nucleus, thiouracil nucleus, etc. The heterocycle may contain carbon-containing substituents having up to 12 carbon atoms. Preferred substituents are methyl group, ethyl group, Ter
Substituted or unsubstituted alkyl groups such as t-butyl group, carboxymethyl group, carboxyethyl group, ethylidene, propylidene, isopropylidene, phenylethylidene,
Substituted or unsubstituted alkylidene groups such as carboxyphenylethylidene, substituted or unsubstituted aryl groups such as phenyl group, tolyl group, carboxyphenyl group, arylidene groups such as benzylidene group, trilidene group, carboxybenzylidene group, etc. be. R1 has the same meaning as R1 in organic compound (1). ] Compounds represented by general formula (12) include the following. (2) An organic compound represented by the following general formula (wherein Rl5, Rl6, R
l7 and Rl8 are each a hydrogen atom or a carbon atom number of 12
Represents the following carbon-containing substituents.

Groups constituting preferred compounds are substituted or unsubstituted alkyl groups such as methyl, ethyl, probyl, and phenylmethyl. ) Specific compounds include the following.

Compounds represented by general formula (12) are particularly preferred for the present invention.

A good test for determining the suitability of sulfur-containing organic compounds is those that form silver sulfide when reacted with silver bromide, especially when mixed with silver bromide at 25 to 80°C, preferably 30 to 70°C. It is preferable to use one that promotes the formation of silver sulfide when heated to .

The above component c) and component (d) are added to the composition for heat-developable photosensitive materials by various methods in order to be present in the composition.

That is, both components may be added after preparing this composition,
Both components may be added at the same time when preparing this composition, or component c) and component (d) may be added at separate stages. In other words, it is sufficient that Seishu c) and component (d) are present in the blended product. It is particularly preferable for the present invention to add "component" after forming component (a) and component (b) because the sensitization efficiency is high. When a compound having one CONH unit is added, the amount added is in the range of about 0.01 mol to about 2 mol, preferably about 0.07 mol to about 1 mol, per mol of the organic silver salt of a). is the amount within.

If the amount added is too large, the amount of components other than the image-forming components becomes too large, which is undesirable and makes it difficult to obtain an image with a high Dmax.On the other hand, if the amount added is too small, the effect of the present invention will be small. The sulfur-containing organic compound is used in an amount ranging from 10@-2 mol to 10@-10 mol, preferably from 10 A mol to 10@4 mol, per mol of the organic silver salt of component (a).

If the amount of the sulfur-containing organic compound added is too large, thermal fog will occur, and if it is too small, the sensitizing effect will be small. At least component (4) and component (b) prepared in this way
, component (c), and component (C) are sensitized by heating prior to their application.

After preparing component (a) and component (b), add component (4) and component (
Most preferably, the composition comprising 6), 5+<e) and component (to) is heated. Heating is at a temperature in the range of about 25 mm to 80°C, preferably in the range of 300 to 70°C. Heating times range from about 5 minutes to about 300 minutes, preferably from about 10 minutes to about 180 minutes. However, the optimal conditions for heating are determined by the types of components in the composition and their combination, and cannot be determined uniquely. usually,
It is determined by careful experimentation with a given composition. The composition sensitized according to the present invention is used to constitute a photosensitive layer of a heat-developable photosensitive material, and an organic silver salt is a necessary component for forming an image on this photothermographic material. There is a reducing agent (Seishu e)). The reducing agent is one that is capable of reducing the organic silver salt (formation a)) when heated in the presence of exposed silver halide. The reducing agent actually used is determined by the type and performance of the organic silver salt used. The reducing agent of component (e) used in the present invention is preferably one capable of reducing the organic silver salt (component (a)) when heated in the presence of a photocatalyst such as exposed silver halide. It is.

The reducing agent actually used is determined by the type and performance of the organic silver salt used. Specific examples of reducing agents are as follows.

(1) Substituted phenols: aminophenols, such as 2,4-diaminophenol, methylaminophenol, p-aminophenol, o-aminophenol, 2
-Methoxy-4-aminophenol, 2-β-hydroxyethyl-4-aminophenol, 4-amino-2.6
-dipromophenol, 4-amino-2-methylphenol sulfate, 4-amino-3-methylphenol sulfate, 4-amino-2,6-short phenol, 4-amino-2,6-dichlorophenol hydrochloride, N-methyl-p-aminophenol sulfate, 4-benzylidene aminophenol, 4-isopropylidene aminophenol, 2,4-diamino-6-
Methylphenol, 4-acylaminophenol in which the acyl group contains 2 to 18 carbon atoms, N-(4-hydroxyphenyl)-aminoacetic acid, 4-hydroxyphenylcarbamic acid ethyl ester, 6-dimethylamino-3 −
Hydroxytoluene, N-(4-hydroxyphenyl)-N' in which the alkyl group contains 1 to 18 carbon atoms
-alkylurea, N-(4-hydroxy-3,5-di-t-butylphenyl)-N'-octadecylurea, N-
(4-human koma xy-3,5-dichlorophenyl)-N7
-Octadecylurea, 3-chloro-4-hydroxydiphenylamine, 4-(4-hydroxybenzylideneamino)-2-methylphenol, 4-(4-hydroxybenzylideneamino)-3-methylphenol, 4-
(3-hydroxybenzylideneamino)phenol, α
・α5-bis-(4-human loxyphenylamino)
-p-xylene, 4-benzylidene-amino-2-methylphenol, 4-(2-hydroxybenzylideneamino)-phenol, α・α5-bis(4-hydroxy-
3-methylphenylimino)-p-xylene, 2-acylaminophenol in which the cyacyl group contains 1 to 18 carbon atoms, N in which the alkyl group contains 1 to 18 carbon atoms
-(2-hydroxyphenyl)-N'-alkylurea,
6-aminophenolsulfonic acid mono(3)-amide, 6
-Amino niphenolsulfonic acid-(3)-dimethylamide, 2-aminophenolsulfonic acid mono(4)-
amide, 2-benzylidene aminophenol, 4-(4
-Hydroxybenzylidene amino)phenol, α・α
7-bis-(2-hydroxyphenylamino)-p-xylene, 3-(2-hydroxyphenylaminohydrazono)
-2-oxooxolane, 3-(4-hydroxyphenylhydrazono)-2-oxooxolane, 4-hydroxyanilino-methanesulfonic acid, 4-hydroxy-
3-methylanilino-methanesulfonic acid, etc.; alkyl-substituted phenols, such as pt-butylphenol,
p-t-amylphenol, p-cresol, 2,6-
Di-t-butyl-p-cresol, p-ethylphenol, p-Sec-butylphenol, 2,3-dimethylphenol, 3,4-xylenol, 2,4-xylenol, 2,4-di-t-butyl Phenol, 2, 4, 5
-trimethylphenol, p-nonylphenol, p-
Octylphenol, 2,4,6-tri-t-butylphenol, 2,6-di-t-butyl-4-octylphenol, 2,6-di-t-butyl-4-ethylphenol, 2,4. 6-tri-t-amylphenol, 2.6
-di-t-butylphenol, 2-isopropyl-p-
Cresol, 3-methyl-3-(3-methyl-4-hydroxyphenyl)pentane, 2,6-di-t-butyl-
4-nonylphenol, 2,4-di-t-butyl-6-
nonylphenol, etc.; aryl substituted phenols, such as p-phenylphenol, o-phenylphenol, α-phenyl 0-cresol, etc.; other phenols, such as p-acetophenol, p-acetoacetylphenol, 1.4 -dimethoxybenzene, 2,6-
Dimethoxyphenol, chlorthymol, 3,5-di-t-butyl-4-hydroxybenzyldimethylamine,
2,6-dicyclohexyl-p-cresol, 2●6
-di-t-butyl-4-methoxymethylphenol, 4
Methoxyphenol, 2-methyl-4-methylmercaptophenol, 2,6-dicyclopentyl-p-cresol, 2-t-butyl-6-cyclopentyl-p-cresol, 2-t-butyl-6-cyclohexyl-p- Cresol, 2,5-dicyclopentyl-p-cresol, 2,5-dicyclohexyl-p-cresol, 2-cyclopentyl-4-t-butylphenol, 3,5-di-t-butyl-4-hydroxybenzophenone , 3・5
-di-t-butyl-4-hydroxycinnamic acid, 3,5-di-t-butyl-4-hydroxybenzaldehyde, 3.
5 di-t-butyl-4-hydroxycinnamic acid ester, sulfonamidophenols as described in U.S. Pat. No. 3,801,321; polyvinyl (2-hydroxy-
3-methoxybenzal); West German Patent Publication No. 231908
Hydroxyindanes such as those described in US Pat. (2) Substituted or unsubstituted bis, tris, and tetrakis phenols:
o-bisphenols, such as 1,1-bis(2-hydroxy-3,5-dimethylphenyl)-3,5,5-
Trimethylhexane, bis(2-hydroxy-3-t-
butyl-5-methylphenyl)methane, bis(2-hydroxy-3,5-di-t-butylphenyl)methane, bis(2-hydroxy-3-t-butyl-5-ethylphenyl)methane, 2●6-methylenebis( 2-Hydroxy-3-t-butyl-5-methylphenyl)-4-methylphenol, 1,1-pis(5-chloro-2-hydroxyphenyl)methane, 2,Z-methylenebis[4-methyl-6- (1-methylcyclohexyl)phenol],
1,1-bis-(2-hydroxy-3,5-dimethylphenyl)-2-methylpropane, 1,1,5,5-tetrabis-(2-hydroxy-3,5-dimethylphenyl)-2・4-ethylpentane, 3,3',5,5'-tetramethyl-6,6'-dihydroxy-triphenylmethane, 1,1-bis(2-hydroxy-3,5-di-t)
-butylphenyl)-pentane, 1,1-bis(2-hydroxy-3,5-di-t-butylphenyl)-ethane, 1,1-bis(2-hydroxy-3,5-di-t-butylphenyl)- Propane, 1●1-bis(2-hydroxy-3,5-di-t-butylphenyl)-butane and 1,1-bis(2-hydroxy-3,5-di-t-amylphenyl)ethane, 1,1 -bis(2-hydroxy-
3-cyclohexyl-5-t-butylphenyl)methane, 1,1-bis(2-hydroxy-3-cyclopentyl-5-t-butylphenyl)-2● 52-dimethylethane, bis(2-hydroxy-3-cyclopentyl- 5
-Methyl-6-cyclopentylphenyl) sulfide, 1,1-bis(2-hydroxy-3-cyclopentyl-5-t-butylphenyl)butane, 1,1-bis(2
-Hydroxy-3-cyclopentyl-5-t-butylphenyl)methane, 1,1-bis(2-hydroxy-3.
5-dicyclopentyl-6-methylphenyl)methane, 1,1-bis(2-hydroxy-3,6-dicyclopentyl-5-methylphenyl)methane, bis(2-hydroxy-13-cyclopentyl-5-t-butylphenyl)sulfide , bis(2-hydroxy-3-cyclohexyl-5-t-butylphenyl) sulfide, 1
・1-bis(2-hydroxy-3-t-butylphenyl)methane, p-cresol-acetaldehyde or formaldehyde novolak resin, bis(2-hydroxy-3-t-butyl-5-methylphenyl)sulfide, 1.1- Bis(2-hydroxy-3,5-dimethylphenyl)methane, 1,1-bis(2-hydroxy-3,
5-di-t-butylphenyl)-2-methylpropane,
1,2-bis(2-hydroxy-3-t-butyldibenzofuryl)ethane, 3,3',5,5'-tetra-t-
Butyl-6,6'-dihydroxytriphenylmethane;
p-bisphenols, e.g. bisphenol A,4
・l-methylenebis(3-methyl-5-t-butylphenol), 4,4'-methylenebis(2,6-di-t-butylphenol)
-butylphenol), 3,3',5,5'-tetra-
t-Butyl-4.4'-dihydroxybiphenyl, 4.
4'-dihydroxybiphenyl, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(3
・5-dibromo-4-hydroxyphenyl)propane,
2,2-bis(3,5-dichloro-4-hydroxyphenyl)propane, 2,2-bis(3,5-dimethyl-4
-hydroxyphenyl)propane, 2●2-bis(3-
Methyl-4-hydroxyphenyl)propane, bis(3
-methyl-4-hydroxy-5-t-butylphenyl)
Sulfide, 2,2-bis(4-hydroxy-3,5
-di-t-butylphenylthio)propane, 4,4'-
Butylidenebis(6-t-butyl-3-methylphenol), 4,4'-thiobis(6-t-butyl-3-methylphenol), 4,4'-thiobis(6-t-butyl-2-methylphenol) ), 4,4'-butylidene-bis-(6-methylphenol), 4,4'-benzylidene-bis-(2-t-butylphenol), 4,24'
1-ethylidene-bis-(6-t-butyl-0-cresol), 4.l-ethylidene-bis-(2-t-amylphenol), 4.4'-(p-chlorobenzylidene)-
Di-(2,6-xylenol), 4,4'-ethylidene-bis-(2-cyclohexylphenol), 4,4'
-pentylidene-(0-cresol), 4.4/1(p-bromo-5-benzylidene)-diphenol,
4,4'-propylidene-bis (2-phenylphenol), 4,4'-ethylidene (2,6-xylenol), 4,4-heptylidene (0-cresol), 4,4/ -ethylidene-bis-(2,116-di-t-butylphenol), 4,4'(2-butenylidene)-di-(2,6-xylenol), 4,4'-(p
-methylbenzylidene)1(0-cresol), 4
・4′-(p-methoxybenzylidene)-bis-(2・
6-Ji 1. t-butylphenol), 4,4'-(
p-nitrobenzylidene)-di1(2,6-xylenol), 4,4'-(p-hydroxybenzylidene)1di1(0-cresol), 2,2-bis(31methyl-4
-Hydroxy-5-t-butylphenyl)propane, α・α7-(4-hydroxy-3,5-di-t-butylphenyl)dimethyl ether, 4,4′-dihydroxy-3・3′・5・5′ -tetra-t-butylbiphenyl, 4,4'-dihydroxy-3,3'-dimethylbiphenyl, 2-bisphenol Al2,2-bis(3-
Methyl-4-hydroxy-5-t-butylphenyl)propane, 2,2-bis(4-hydroxy-3,5-di-t-butylphenyl)propane, 2,2-bis(4-hydroxy-3,5- diethyl 3-phenyl) propane,
2,2-bis(4-hydroxy-3-methyl-5-t-
amyl phenyl)propane, 2,2-bis(4-hydroxy-3,5-di-t-amyl phenyl)propane; others, such as 'S3,5-di-t-butyl-4-hypolymerizate 3
Droxybenzyldimethylamine, 2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)
Phenol, N-N'-di(4-hydroxyphenyl)
Polyphenols such as urea, tetra-scratch [methylene-(3,5-di-1-t-butyl-4-4-hydroxyhydrocinnamate)]methane, diethylstilbestrol, hexestrol, bis-(3,5-di-t-butyl-4-4-hydroxyhydrocinnamate), Examples include (1-t-butyl-4-hydroxybenzyl)-1 ether and 2,6-bis(2'-hydroxy-3'-t-butyl-5'-methylbenzyl)-4-methylphenol.

3) Substituted or unsubstituted mono- or bisnaphthols and di- or polyhydroxynaphthalenes: bis-β-naphthols, e.g. 2,2'-dihydroxy-1,1'-
Hinabutyl, 6,6'-dibromo-2,2'-dihydroxy-1, V-hinabutyl, 6,6'-dinitro-2,
2'-dihydroxy-1・V-hinabutyl, bis(2-
hydroxy-1-naphthyl)methane, 4,4'-dimethoxy-1,V-dihydroxy-2,2'-hinabutyl;
Naphthols, such as α-naphthol, β-naphthol, 1-hydroxy-4-amino-naphthalene, 1.5
-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1-hydroxy-2-phenyl-4-methoxynaphthalene, 1-hydroxy-2-methyl-4-methoxynaphthalene, 1-hydroxy-4-methoxynaphthalene, 1,4- Dihydroxynaphthalene, methylhydroxynaphthalene, sodium 1-amino-2-naphthol-6-sulfonate, 1-naphthylamine-J sulfonic acid, 2,3 dihydroxynaphthalene, 1-hydroxy 2-sulfonic acid
-Carboxynaphthalene, 1-hydroxy-4-methoxy-dihydronaphthalene, 2-hydroxy-3-carboxynaphthalene, 1-hydroxy-4-ethoxynaphthalene, 1-hydroxy-4-propoxynaphthalene, 1
-Hydroxy-4-isopropoxynaphthalene, 1-hydroxy-5-methoxynaphthalene, morpholino (1
-hydroxy-4-methoxynaphthyl (2)) methane,
Sulfonamide naphthols, 2-hydroxy-3-aminonaphthalenes, 1 containing 1 to 18 carbon atoms in the acyl group, as described in U.S. Pat. No. 3,801,321;
Hydroxy-5-acylaminonaphthalene; 4) Di- or polyhydroxybenzenes and hydroxy monoethers; Hydroquinone; Alkyl-substituted hydroquinones, such as methylhydroquinone, t-butylhydroquinone,
2,5-dimethylhydroquinone, 2,6-dimethylhydroquinone, t-octylhydroquinone, 2,5-di-t-
Butylhydroquinone, ethylhydroquinone, etc.: halogeno-substituted hydroquinones, such as chlorohydroquinone, dichlorohydroquinone, bromohydroquinone, etc.; alkoxy-substituted hydroquinones, such as methoxyhydroquinone, ethoxyhydroquinone; other substituted hydroquinones,
For example, phenylhydroquinone, hydroquinone monosulfonate, 2,5-dihydroxyalkyl (C1-18
) Hydroquinone, 2-ethoxycarbonylhydroquinone, acetylhydroquinone, 2-cyclohexylhydroquinone, (2,5-dihydroxyphenyl)-5-(1-
phenyltetrazolyl) sulfide, (6-methyl-
2,5-dihydroxyphenyl)-5-(phenyltetrazolyl)sulfide, (2,5-dihydroxyphenyl)-2-(benzothiazolyl)sulfide, 2-
Dodecyl-5-(5-carboxybentyl)-hydroquinone, 2-dodecyl-5-(9-carboxynonyl Y-
Hydroquinone, 2-tetradecyl-5-(5-carboxypentyl)-hydroquinone, 2-tetradecyl-5-
(9-carboxynonyl)-hydroquinonelihydroquinone monoethers, such as p-methoxyphenol,
p-ethoxyphenol, hydroquinone monobenzyl ether, 2-t-butyl-4-methoxyphenol,
2,5-di-t-butyl-4-methoxyphenol, hydroquinone mono-n-propyl ether, hydroquinone mono-n-hexyl ether; others, such as catechol, 4-phenylcatechol, 3-(dihexylamino
．． dimethyl)-5-phenylcatechol, 3-(di-n
-hexylaminomethyl)-5-phenylcatechol,
3-Cyclohexylpyrocatechol, 4-cyclohexylpyrocatechol, 4-(α-methylbenzyl)birocatechol, 5-cyclohexylpyrocatechol, 5-
(N-N-dihexylaminomethyl)-4-phenylcatechol, 4-laurocatechol, t-butylcatechol, birogallol, azeroylbirogallol, behenoylpyrogallol, 4-ste-4aroylpyrogallol, di-t- -butylpyrogallol, butyrylpyrogallol, 4-azeroylbispirogallol, phloroglucinol, resorcinol, 4,6-di-t-butylresorcinol, 4- in which the alkyl group contains 1 to 18 carbon atoms
Alkylresorcinol, 1-chloro-2,4-dihydroxybenzene, 3,5-di-t-butyl-2,6-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid,
2,4-dihydroxyphenyl sulfide, 2,3-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid,
2,5-dihydroxybenzoic acid, o-aminobenzoic acid,
m-aminobenzoic acid, p-aminobenzoic acid, protocatechyaldehyde, ethyl protocatekyate, zetyl protocatekyate, 4-(3', l-dihydroxyphenylazo)benzoic acid, 3,4-dihydroxyphenylacetic acid,
1-acetyl-2,3,4-trihydroxybenzene,
2,2-methylenebis(3,4,5-trihydroxyphenyl)benzoic acid, gallic acid, methyl gallate, propyl gallate, butyl gallate, sodium gallate, ammonium gallate, dodecyl gallate, ethyl gallate , isoprobyl gallate, gallic acid anilide, 3/4
-5-trihydroxyacetophenone, 5) Ascorbic acid and its derivatives: l-ascorbic acid: isoascorbic acid: monoesters of ascorbic acid, e.g.
Ascorbic acid monolaurate, monomyristate,
Monopalmitate, monostearate, monobehenate, monobenzonate, 6-ascorbyl-6-palmitate-5-β-monocarboxypropionate, etc.: Diesters of ascorbic acid, such as dilaurate, dimyristate, divalmitate, distearate, etc. of ascorbic acid. ;U.S. Patent 33 for ascorbic acids
Those described in No. 37342 can also be used.

;) 3-pyrazolidones, pyrazolines and pyrazolones: for example, 1-phenyl-3-pyrazolidone, 4-
Methyl-4-hydroxymethyl-1-phenyl-3-pyrazolidones and those described in British Patent No. 930572, pyrazolin-5-ones as described in U.S. Pat. No. 3,770,448, JP-A-48-28221
Pyrazolidine-13-ones as described in No.
1-(2-quinolyl)-3-methyl-5-pyrazolone, etc., (7) Reducing sugars: glucose, lactose, etc.
(8) Phenylene diamines: o-phenylene diamine, p-phenylene diamine, N-N'-dimethyl-p-
Phenylene diamine, NIN'-diethyl-p-phenylene diamine, N-phenyl-N'-isopropyl-p
-phenylenediamine, N-N'-dibenzylidene-p
-phenylenediamine, N-N-diethyl-N'-sulfomethyl-p-phenylenediamine, N-benzylidene-N'・N'-diethyl-p-phenylenediamine, N
-N-dimethyl-N'-sulfomethyl-p-phenylenediamine, 3-methoxy-4-sulfomethylamino-N
-N'-diethylaniline, N-(3- hydroxybenzylidene)-N'
・N'-diethyl-p-phenylenediamine, N-(4
hydroxybenzylidene)-N'/N'-diethyl p
-phenylenediamine, N-N-diethyl-3-methyl-p-phenylenediamine, N.N-diethyl-p-phenylenediamine trifluoroacetate, hydroxyethylparamine, etc. Patent 3
In combination with phenolic or activated methylene color couplers such as those described in Nos. 53128C and 3764328, color images can be obtained.

Similarly, color images can be obtained by US Pat. No. 3,761,270.

(9) Hydroxylamines: e.g. US Pat. No. 3,667
Hydroxylamines such as those described in No. 958 and JP-A No. 48-28221.

(Own) Reductones: For example, aminohexose reductones, anhydroaminohexose reductones, and anhydrodihydroaminohexose reductones as described in U.S. Pat. No. 3,679,426, Pelkey Patent No. 786,086 Linear aminoreductones such as those listed in the issue.

a]) Hydroxamic acids: for example, U.S. Pat.
Hydroxamic acids such as those described in US Pat. No. 1,252 and US Pat.

Others: indane-1,3-diones with at least one hydrogen atom in the 2-position as described in U.S. Pat. No. 3,773,512, amidoximes as described in U.S. Pat. No. 3,794,488, West Germany Substituted hydropyridines as described in US Pat. No. 2,308,766, organic hydrazone compounds as described in US Pat. No. 3,615,533, US Pat. No. 3,667,958
Hydrazines, amino-9, etc. as described in No.
10-dihydroacridines, US Patent 383904
1,4-dihydropyridines as described in No. 8, acetoacetonitrile, homogentisic acid and homogentisic acid amides, hydroxytetronic acids and hydroxytetronimides, kojic acid, hinokitiol, p-oxyphenylglycine, 4・4'-diaminodiphenyl, 4,41-dimethylaminodiphenyl, 4
・L-diethylaminotriphenylmethane, spiroindane, 4-methylescurene to 4; Among the above reducing agents, at least one of the substitution positions adjacent to the hydroxyl substitution position of the aromatic nucleus is substituted with, for example, a methyl group, an ethyl group, or a propyl group. Mono-, pis-, tris-, or tetrakis-phenols having alkyl or acyl groups such as isopropyl or butyl groups, e.g. It has the advantage of being stable and less susceptible to photodiscoloration.

These phenolic reducing agents exhibit favorable effects especially when used together with fatty acid silver. For example, West German Patent Publication No. 232
No. 1328, Japanese Unexamined Patent Publication No. 5036110, No. 50-116
No. 023, No. 50147711, No. 51-23721
No. 51-32324 and No. 51-51933.

Furthermore, as described in U.S. Pat. No. 3,827,889, if the reducing agent is photodegradable or otherwise inactivated by light, it may be decomposed by light when the photosensitive material is left in a bright room after development. Otherwise, it is inactivated and the reduction no longer progresses, which is preferable because there will be no photodiscoloration.

Examples of the photodegradable reducing agent include ascorbic acid or its derivatives, furoin, benzoin, dihydroxyacetone, glyceraldehyde, tetrahydroxyquinone rhodisonate, and 4-methoxy-1-naphthol. As described in U.S. Pat. A positive image can also be obtained. Furthermore, a compound that promotes the photodegradability of the reducing agent can be used in combination. The most preferred reducing agents are 2,4-dialkyl substituted orthobisphenols or 2,6-dialkyl substituted parabisphenols or mixtures thereof. For example, a reducing agent represented by the following formula is suitable. Here, R1, R
2, R5, R6 are alkyl group (C1-5), cyclopentyl group, cyclohexyl group, R3, R4, R7, R8
is a H1 alkyl group (C1-8), an aryl group (such as a phenyl group), a substituted aryl group (a carboxyphenyl group,
Halogen 7-substituted phenyl group, alkoxy-substituted phenyl group,
nitro-substituted phenyl group, etc.), aralkyl group (benzyl group, β-phenylethyl group, etc.).

A suitable reducing agent is selected based on the type (performance) of the organic silver salt (component (a)) used.

For example, stronger reducing agents are suitable for silver salts that are relatively difficult to reduce, such as silver salts of benzotriazole and silver behenate; For silver salts that are easily reduced, weaker reducing agents are suitable.

Suitable reducing agents for the silver salt of benzotriazole include, for example, 1-phenyl-3-pyrazolidones, ascorbic acid, monocarboxylic acid esters of ascorbic acid, and naphthols such as 4-methoxy-1-naphthols. There are many types of silver behenate, including bis(hydroxyphenyl)methane-based o-bisphenols and hydroquinone. In addition, for silver phosphate and silver laurate, p-bisphenols such as substituted tetrakidphenols, bis(hydroxyphenyl)alkane o-bisphenols, substituted products of bisphenol A, and p -Phenylphenol and the like. The amount of reducing agent used in the present invention depends on the type of organic silver salt and reducing agent,
Although it varies depending on other additives, it is generally appropriate to use about 0.05 mol to about 10 mol, preferably about 0.1 to about 3 mol, per mol of organic silver salt. Two or more of the various reducing agents mentioned above may be used in combination.

For specific examples of combinations of two types of reducing agents, see JP-A-49
-115540, U.S. Patent No. 3667958, U.S. Patent No. 37
No. 51249, particularly effective reducing agent combinations include esters of carboxylic acids derived from phenols with bulky ortho substituents and monohydric or polyhydric alcohols or phenols; Polyhydric phenols with ortho substituents, or phenols with bulky ortho substituents, consisting of esters of mono- or polycarboxylic acids with alcohols derived from phenols with bulky ortho substituents at least one carboxylic acid ester and o- or p
- Can be used in combination with bisphenols.

In this combination case, reduction of heat fog, increase in whiteness,
Photostabilization after treatment is achieved. In addition, the use of a mono- or polyphenol reducing agent having an alkyl group at both substitution positions adjacent to the hydroxyl group substitution positions of the aromatic nucleus is effective in preventing photodiscoloration. In addition, it has been confirmed that development is accelerated by the combined use of a compound of tin, iron, cobalt, or nickel and a reducing agent. The amount of these auxiliary reducing agents varies widely depending on the strength of the reducing power of the main reducing agent and the auxiliary reducing agent and the reducibility of the organic silver salt oxidizing agent. ~1 mol, more preferably 1
What is necessary is just to use together 0-3-0.8 mol. In addition, some optical sensitizing dyes that are said to be effective for gelatin silver halide emulsions also have a sensitizing effect on the composition for heat-developable photosensitive materials obtained by the present invention. exhibits. Effective optical sensitizing dyes include cyanine, merocyanine, tananine, and complex (trinuclear or tetranuclear).
Examples include cyanine or merocyanine, holopolar cyanine, styryl, hemicyanine, oxonol, hemioxonol, and xanthine dyes. Among the cyanine dyes, those having a basic nucleus such as a thiazoline nucleus, an oxazoline nucleus, a pyrroline nucleus, a pyridine nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus, and an imidazole nucleus are more preferable. Such nuclei include alkyl groups, alkylene groups, hydroxyalkyl groups, sulfoalkyl groups,
It may contain carboxyalkyl groups, aminoalkyl groups or enamine groups capable of forming fused carbocyclic or heterocyclic rings. The chemical structure may be symmetrical or asymmetrical, and the methyl chain or polymethine chain may have an alkyl group, phenyl group, enamine group, or heterocyclic substituent. In particular, cyanine dyes having an imino group or a carboxyl group are effective for sensitization. In addition to the above-mentioned basic nucleus, merocyanine dyes include, for example, a thiohydantoin nucleus, a rhodanine nucleus, an oxazolidinedione nucleus, a thiazolidinedione nucleus,
It may have an acidic nucleus such as a barbituric acid nucleus, a thiazolinone nucleus, a malononitrile nucleus, or a pyrazolone nucleus.
These acidic nuclei may be further substituted with an alkyl group, an alkylene group, a phenyl group, a carboxyalkyl group, a sulfoalkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an alkylamine group, or a heterocyclic nucleus.
In particular, merocyanine dyes having an imino group or a carboxyl group are effective for sensitization. These dyes may be used in combination if necessary. Furthermore, ascorbic acid derivatives,
azaindenes, cadmium salts, organic sulfonic acids, etc.
For example, US Patent No. 2983390, US Patent No. 293708
A supersensitizing additive that does not absorb visible light as described in various specifications such as No. 9 can be used in combination. Particularly effective sensitizing dyes include merocyanine dyes having a rhodanine nucleus, a thiohydantoin nucleus, or a 2-thio-2,4-oxazolidinedione nucleus, such as those described in U.S. Pat. No. 3,761,279; p-carboxyphenyl-5-[β-ethyl-2(3-benzoxazolylidene)ethylidene]rhodanine, 5-[(3β-carboxyethyl-2(3-thiazolinylidene)ethylidene]-3-ethylrhodanine, 3- carboxymethyl-
5-[(3-methylthiazolinylidene)-α-ethylethylidene]rhodanine, 1-carboxymethyl-5-[
(3-ethyl-2(3H)-benzoxazolylidene)
ethylidene]-3-phenyl-2-thiohydantoin,
5-[(3-ethyl-2-benzoxazolinylidene)
-1-methyl-ethylidene]-3-[(3pyrroline-1
-yl)propyl]rhodanine, 3-ethyl-5-[(3
-ethyl-2(3H)-benzothiazolylidene)isopropylidene]-2-thio-2,4-oxazolidinedione, 3-carboxymethyl-5-[(3-methyl-2(
3H)-Thiazolinylidene)isopropylidene]rhodanine, 3-ethyl-5-[(3-methyl-2-thiazolinylidene)ethylidene]rhodanine, 3-ethyl-5-(1
-Methyl-2(1H)-pyridylidene)rhodanine, 3-
Ethyl-5-(3,4-dimethyl-2(3H)-thiazolilidene)rhodanine, 1-carboxymethyl-5(3-
Ethyl-2-benzoxazolinylidene)-3-phenyl-2-thiohydantoin, 1-ethyl-[3-ethyl-2(3H)-benzoxazolidiene)ethylidene]
-3-n-butyl-2-thiohydantoin, 1-methyl-3-allyl-5-[2(3-ethylbenzoxazolidene-(2)-ethylidene]-2-thiohydantoin,
1-Carboxymethyl-3(N-methylbenzothiazolyl indyl)-4thia-2-thiohydantoin, 5-[
(3-ethyl-2(3H)-naphtho-[2,1]-oxazolilidene)ethylidene]-3-n-heptyl-1-
Phenyl-2-thiohydantoin, 3-ethyl-5-[
(3-ethyl-2(3H)-naphtho-[2.1]-oxazolilidene)ethylidene]1-phenyl-2-thiohydantoin, 3-allyl-5-[3-ethyl-(2-naphthoxazolidene) ethylidene]-1-phenyl-2
-Thiohytantone, 5-[(3-ethylthiazolidine-2-yridine)-ethylidene]-3-allyl-2-thioxazolidine-2,4-dione, 3-ethyl-5-
Examples include [(3-methyl-2(3H)-benzo*, thiazolidene)ethylidene]-2-thio-2,4-oxazolidinedione and merocyanine dyes represented by the following formula.

The above is just an example and is not limited to this.

Examples of cyanine dyes include, but are not limited to, the following dyes. Other examples include trinuclear merocyanine dyes as described in U.S. Pat. No. 3,719,495, polycyclic aromatic dyes as described in Pelkey Patent No. 788,695, Sensitizing dyes for silver iodide, styrylquinoline dyes as described in JP-A No. 49-84637, tananine dyes as described in West German Patent Publication No. 2405713, also Nos. 2401982 and 2401982; ★24
No. 04591, JP-A-50-2924 and JP-A-50
For example, as described in No.-29029,
Acidic dyes such as Goodichlorfluorescein dye, JP-A-50-104637, JP-A-50-105127,
Merocyanine dyes such as those described in No. 51-27924 and No. 50-156424 can also be used in the present invention.

Specific examples of merocyanine dyes with effective pyrazolone cores are as follows. The amount of these pigments added is component (5)
of silver halide, or from about 10@-4 mole to about 1 mole per mole of silver halide-forming component.

Toning agents can be used with these reducing agents.

This toning agent is preferably used when the resulting image is desired to be a deep-colored image, especially a black image. The amount used is about 0.0001 mol to about 2 mol, preferably about 0.0 mol per mol of organic silver salt.
0.005 moles to about 1 mole. The effective toning agent depends on the organic silver salt and reducing agent used, but the most common toning agents are heterocyclic ones having one C-N unit (R is hydrogen, hydroxy, metal ion, substituted carbonyl group, etc.). Typical organic compounds include phthalazinones, oxazinediones, cyclic imides, quinazolinones, N-hydroxyphthalimides, urazoles, and 2-pyrazolin-5-ones. More specific compounds are as follows: phthalazinone, 2-acetyl phthalazinone, 2-phthalyl phthalazinone, N-methyl phthalazinone, 2-pivaloyl phthalazinone, 2-carbamoyl phthalazinone. Talazinone, 2-(3,4 dimethoxybenzoyl) phthalazinone, 2-lauroyl phthalazinone, 2-benzoylphthalazinone, 2-(p-methoxybenzoyl) phthalazinone, 2-ethoxyformyl phthalazinone, JP-A-1988 -67132 and U.S. Patent 38
Phthalazinone derivatives as described in No. 44797, phthalazinone salts such as silver phthalazinone, JP-A-49
Quinazolinediones and benzoxazinediones or naphthoxazinediones described in No. -91215 and No. 50-2524, West German Patent Publication No. 2140
Cyclic imides such as substituted phthalimides as described in US Pat. No. 406 and No. 2,141,063;
quinazolinones as described in No. 46136;
Pyrazolin-5-ones, N-hydroxynaphthalimides described in US Pat. No. 378,294.1, mercapto compounds described in US Pat. No. 3,832,186 and JP-A-49-5020, JP-A-50- 676
Phthalazinediones described in No. 41, JP-A No. 5
Uracils, barbituric acid, saccharin, 5-nitrosactucalin, phthalic anhydride, sulfolene, 2-mercaptobenzoxazole, 2-hydroxybenzothiazole, 2-amino-
6-methylbenzothiazole, 2-amino-4-(4-
Biphenylyl)thiazole, imidazole, 2-hydroxy-benzimidazole, N-mer ethylenethiourea, 1-acetyl-2-thiohydantoin, and the like.

Further, as described in US Pat. No. 3,847,612, black toning can be achieved by using phthalic acid, naphthoic acid, or phthalamic acid in combination with imidazoles.

Similarly, a preferable combination example includes the combination of phthalazinone and 2-acylphthalazinone. Of course, two or more of these color toning agents can be used in combination to obtain preferable photographic properties. Further, a toning agent may be contained in the support, the back surface of the support, or an undercoat layer or a soil coating layer provided on the surface of the support, giving preferable results. Various methods can be applied to the composition for heat-developable photosensitive materials of the present invention in order to prevent heat build-up.

One of the methods uses a mercury compound as described in Japanese Patent Publication No. 47-11113. Alternatively, a mercury compound can be used to directly obtain a positive image as described in US Pat. No. 3,589,901.
Additionally, mercury compounds can be used in combination with color-forming couplers to create stable color images, as described, for example, in U.S. Pat. No. 3,764,328. Furthermore, as another method for preventing heat fog, for example, U.S. Pat.
No. 645739, JP-A-49-125016, JP-A No. 49
-130720, 50-57619 and JP-A-4
lauric acid, as described in No. 8-89720;
Higher fatty acids such as myristic acid, palmitic acid, stearic acid, behenic acid, tetrahalogenophthalic acid or its anhydride, aryl sulfonic acids such as benzenesulfonic acid and p-toluenesulfonic acid, benzenesulfinic acid and p-toluenesulfonic acid,
- arylsulfinic acids such as toluenesulfinic acid,
or its salts, thiosulfinates such as sodium benzenethiosulfinate, lithium myristate,
Salts such as lithium salts of higher fatty acids such as lithium stearate, lithium behenate, lithium palmitate, and lithium laurate can be used as acid stabilizers. Other acid stabilizers include salicylic acid, p-hydroxybenzoic acid, tetrabromobenzoic acid, tetrachlorobenzoic acid, p-acetamidobenzoic acid, alkyl-substituted benzoic acids such as pt-butylbenzoic acid, phthalic acid, isophthalic acid, and trimerizate. Acid, pyromellitic acid, diphenic acid, 5
',5'-methylenebissalicylic acid and the like are also effective.
These acid stabilizers not only prevent heat fog, but in some cases, they also prevent photodiscoloration when exposed to white light, increase image density, and improve shelf life (after storage). In many cases, they also have the effect of improving the photographic properties of the light-sensitive material (the property of maintaining the photographic properties immediately after production). Other compounds that are extremely effective in preventing heat fog and desensitization of the compositions of the present invention include benzotriazole and its derivatives. Examples of benzotriazole derivatives include the following compounds. Chlorobenzotriazole, bromobenzotriazole, butoxybenzotriazole, octoxybenzotriazole, benzyloxybenzotriazole, N-acetylbenzotriazole, butyrylaminobenzotriazole, valerylaminobenzotriazole, propylbenzotriazole, butylbenzotriazole, etc. be.

Furthermore, when complex salts such as chromium salts, rhodium salts, copper salts, nickel salts, and cobalt salts; rhodium, iron, and cobalt are present during or before silver halide formation, heat fog can be prevented and sensitization can be prevented. Effective for improving photographic properties. others,
In order to improve the resolution, particularly in film sensitive materials, light-absorbing dyes such as those described in Japanese Patent Publication No. 33692/1983 can be used.

In addition, in order to improve the fresh storage property, for example,
Leuco dye compounds such as those described in No. 025 can be used. Furthermore, as described in JP-A No. 50-116023, in order to improve the residual color of the pigment, it is possible to improve the whiteness by inking blue ink using a blue dye such as Victoria Blue. It is.

In some cases, the processed photosensitive material may also be stabilized against light and heat. Effective methods include, for example, a method of stabilizing with a solution containing a mercabuto compound, as described in U.S. Pat.
Mention may be made of a method of providing a laminate containing a stabilizer.
Each component used in the invention is dispersed in at least one colloid used as a binder.

Suitable binders are generally hydrophobic, but may also be hydrophilic. These binders are transparent or translucent, and include proteins such as gelatin, gelatin derivatives,
Included are cellulose derivatives, polysaccharides such as dextran, naturally occurring substances such as gum arapia, etc., especially latex-like vinyl compounds which increase the dimensional stability of photographic materials, and synthetic polymers such as those described below. Suitable synthetic polymers include U.S. Pat.
Examples include those described in No. 3386, No. 3062674, No. 3220844, No. 3287289, and No. 3411911. Useful polymers include water-insoluble polymers having monomers such as alkyl acrylates, alkyl methacrylates, acrylic acid, sulfoalkyl acrylates or sulfoalkyl methacrylates, and those having circulating sulfobetaine units as described in Canadian Patent No. 774,054. Examples include things. Suitable high molecular weight materials and resins include polyvinyl butyral, polyacrylamide, cellulose acetate butyrate, cellulose acetate propionate, polymethyl methacrylate, polyvinylpyrrolidone, polystyrene, ethyl cellulose, polyvinyl chloride, chlorinated rubber, polyisobutylene, butadiene styrene. copolymer, vinyl chloride monovinyl acetate copolymer, vinyl chloride monovinyl acetate-tapolymer with maleic acid, polyvinyl alcohol, polyvinyl acetate, benzyl cellulose, cellulose acetate, cellulose propionate, cellulose acetate phthalate, polyvinyl formal, polyvinyl pyridine, Polyvinylidene chloride, methyl vinyl ether maleic anhydride copolymer, polyvinyl acrylamide, cellulose acetate, cellulose nitrate,
Butyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, nitrocellulose, polyethylene, polyethylene glycol, polyethylene oxide, polyacrylate, polysulfoalkyl acrylate, polysulfoalkyl methacrylate, polyamide, terpene resin, alginic acid and its derivatives, onium salt halide conductive polymer , phenolic resin, etc. Among these polymers, polyvinyl butyral, polyvinyl acetate, ethyl cellulose, polymethyl methacrylate, cellulose acetate butyrate, gelatin, and polyvinyl alcohol are particularly preferred. If necessary,
Two or more types may be used in combination. The amount of binder is from about 10:1 to about 1:10, preferably from about 4:1 to about 1:4, by weight to the organic silver salt of Chengzhou a). Japanese Unexamined Patent Publication 1977-46
It can also be made into a lithographic printing plate by using a special binder as described in Japanese Patent No. 59 and US Pat. No. 3,679,414.

It can also be made into a lithographic printing plate by forming a special layer structure as described in US Pat. No. 3,811,886.
Furthermore, US Pat.
It can also be used as a thermal transferable sheet as described in No. 3639.

A photothermographic material containing the composition according to the present invention can have an antistatic layer or a conductive layer.

These layers may further contain water-soluble salts such as halides, nitrates, U.S. Pat.
Ionic polymers such as those described in US Pat. No. 3,428,451 may also be included. It may also have a vapor-deposited metal layer. Antihalation substances or antihalation dyes can be included if desired. As suitable dyes, those which are thermally decolorizable are preferred. For example, dyes such as those described in U.S. Pat. No. 3,769,019, U.S. Pat. Furthermore, for example, U.S. Pat.
No. 527583, No. 2956879 and No. 22747
Filter dyes and light absorbing materials such as those described in No. 82 can be included. If desired, the heat-developable photosensitive material of the present invention may contain calcium carbonate, further starch, titanium dioxide, zinc oxide, silica, dextrin, and US Pat.
Polymeric beads, including beads such as those described in .922101; barium sulfate, alumina, kaolin,
A matting agent such as clay, diatomaceous earth, etc. may be included. Also, for example, West German Patent Nos. 972067 and 1150
No. 274, French Patent No. 1530244, US Patent No. 293
3390 and 3406070, such as stilbenes, triazines, oxazoles, and coumarins. These fluorescent brighteners are used as aqueous solutions or dispersions. The heat-developable photosensitive layer can further contain a plasticizer and a lubricant. Preferred are glycerin, diols and the like, polyalcohols such as those described in U.S. Pat. No. 2,960,404, e.g. U.S. Pat.
88765, 3121060, for example British Patent No. 9550.
Examples include silicone resins such as those described in No. 61.

Also surfactants, such as saponins and alkylaryl sulfonates, such as those described in US Pat. No. 2,600,831, amphoteric compounds, such as those described in US Pat.
It may contain an adduct of glycidol and alkylphenol, an alkoxyphenol surfactant, etc. as described in No. 022878. Among the layers constituting the heat-developable photosensitive material, hardenable layers can be hardened using various organic or inorganic hardeners. Hardeners can be used alone or in combination. Suitable hardeners include aldehydes, blocked aldehydes, ketones, carboxylic acid and carbonic acid derivatives, sulfonate esters, sulfonyl halides and vinylsulfonyl esters, active halogen compounds, epoxy compounds, azilidenes, active olefins, isocyanates, carbodiimides, such as aldehydes. Examples include polymeric hardeners such as starch. Various additives are used to further increase the density of the resulting image. For example, one CO-,- as described in U.S. Pat. No. 3,667,959.
Compounds having groups such as SO- or -SO, 1, such as tetrahydrothiophene-1,1-dioxide,
Non-aqueous polar organic solvents such as 4-hydroxybutanoic acid lactone and methylsulfinylmethane are effective.

Also useful are zinc, cadmium and copper acetates, such as those described in US Pat. No. 3,708,304.
Furthermore, US Pat. No. 3,635,719 and US Pat. No. 3,531,28
Compounds that become alkaline when heated, such as crystalline water-containing compounds as described in No. 5, guanidinium salts, acid salts of amines, metal oxides, or hydroxides, are also effective as substances that promote development. .

A moisture donor can be included to promote development if necessary. In addition to the above-mentioned crystalline water-containing compounds and metal hydroxides, water-donor agents include ureas, prolactam, p-nitroethanol, β-cyanoethanol, glycol, polyethylene glycol, glycerol, sorbitol, and mono- or oligosaccharides. can be mentioned. Polyalkylene glycols and mercaptotetrazoles can also be used in combination to improve sensitivity, contrast, and image density, as described elsewhere in US Pat. No. 3,666,477. In order to improve the raw shelf life, leuco dye compounds such as those described in JP-A-50-62025 can be used. Furthermore, Japanese Patent Application Publication No. 5011962
As described in No. 3, in order to improve the residual color of the dye, it is possible to perform blue ink using a blue dye, such as Victoria Blue, to improve the whiteness.

In the heat-developable photosensitive material of the present invention, an undercoat layer may be provided between the support and the heat-developable photosensitive layer.

As the binder used in this undercoat layer, the various polymers mentioned above can be used. For example, polyvinyl butyral, polyacrylamide, cellulose acetate butyrate, cellulose acetate propionate, polymethyl methacrylate, polystyrene, polyvinylpyrrolidone, ethylcellulose, polyvinyl chloride, chlorinated rubber, polyisobutylene, butadiene-styrene copolymer, vinyl monoacetic chloride. Vinyl copolymer, copolymer of vinyl chloride vinyl monoacetate-maleic acid, polyvinyl alcohol, polyvinyl acetate, cellulose acetate, cellulose propionate, cellulose acetate phthalate, gelatin, gelatin derivatives, JP-A-49-84443
Examples thereof include onium salt halide conductive polymers, polysaccharides, and acidic polymers having units of maleic acid or its ester and acrylic acid or its ester, as described in the above issue. The undercoat polymer layer further contains behenic acid,
Palmitic acid, lauric acid, rosin, diselpenic acid, polyacrylic acid, maleic acid, and polymer acids with acrylic acid units; Contains fatty acid gold salts such as benzotriazoles, mercaptoazoles, lithium laurate, lithium behenate, etc. By increasing the temperature, photographic properties such as photochromic discoloration and thermal fog can be improved. Furthermore, it contains matting agents such as clay, kaolin, starch, barium sulfate, alumina, starch, silica, kaolin, titanium dioxide, and zinc oxide to prevent the emulsion from penetrating into the support and improve resolution. can. Furthermore, U.S. Patent 374
It may also be an electroless deposited layer of conductive metal as described in US Pat. No. 8,137. In addition, by providing a polymer layer on the back side of the support, it increases the moisture resistance of the paper, prevents curling, improves writing properties, and allows transfer or sublimation substances such as toning agents to be transferred from the emulsion layer etc. It is possible to prevent this from happening.

Examples of the polymer for the back polymer layer include gelatin, polyvinyl alcohol, polyvinylpyrrolidone, acrylonitrile-vinylidene copolymer, cellulose acetate butyrate, acrylate copolymer, polyamide resin, coumaron indene resin, cellulose diacetate, ethyl cellulose, and the other polymers for the undercoat. Emulsion binders described below can also be used. This back polymer layer can further contain the above-mentioned color toning agents, reducing agents, dyes, and other additives, and can also be used as a heat transfer material by containing a heat transferable dye. Regarding these, for example, US Pat.
No. 3639. Also, Japanese Patent Publication No. 49-6917
No. 49-128726, JP-A-50-46316, Pelkey Patent No. 798367, U.S. Pat. No. 3,856,526, and U.S. Pat. However, if desired, an overcoat polymer layer can be provided on the photosensitive layer to improve shelf life.

The thickness of the overcoat polymer layer is suitably between about 1 micron and about 20 microns. Suitable polymers for the top polymer layer include polyvinyl chloride, polyvinyl acetate, copolymers of vinyl chloride and vinyl acetate, polystyrene, polymethyl methacrylate, methylcellulose, ethylcellulose, cellulose acetate butyrate, cellulose acetate, polyvinylidene chloride, cellulose. Propionate, cellulose acetate phthalate, polycarbonate, cellulose acetate propionate, polyvinylpyrrolidone, polystyrene, polyvinyltoluene, nitrocellulose, styrene isobutylene copolymer, gelatin acid, polymer latex such as 2-acetoacetoxyethyl methacrylate, carboxypolyesters, etc. can be mentioned. The top coat polymer layer includes titanium dioxide,
By containing a carrier such as polysaccharides such as kaolin, zinc oxide, silica, alumina, and starch, it becomes possible to write with stamp ink, ink, ballpoint pen, pencil, etc.

The top coat polymer layer can also contain antihalation dyes, filter dyes, ultraviolet absorbers, acid stabilizers such as higher fatty acids, and color toning agents such as phthalazinone. The layers containing each component used in the photothermographic material containing the composition according to the present invention and other layers are coated on various supports selected from a wide variety of materials.

Generally, this support can be of any shape, but since it is preferable to have flexibility in handling as an information recording material, it is usually in the form of a film, sheet, roll, or ribbon. It will be done. Examples of the material for the support include plastic film, sheet, glass, wool, cotton cloth, paper, and metals such as aluminum. Examples of plastic films include cellulose acetate film, polyester film, polyethylene terephthalate, polyamide film, polyimide film, triacetate film, polycarbonate film, polyethylene glycol terephthalate oriented polyester film, cellulose nitrate film, cellulose ester film, polyvinyl acetal film, Polystyrene film, polyethylene terephthalate polyester film colored with titanium dioxide, etc., film containing heat-decolorable dye, polyester film with a hydrophilic surface made by dispersing silica etc. in a copolymer partially hydrolyzed with salt and vinyl acetate, gelatin undercoat layer. A polyethylene terephthalate film or the like can be used. In addition to general paper, examples of support paper include photographic base paper, printing paper such as coated paper and art paper, baryta paper,
Resin coated paper, water resistant paper, Pelky patent 7846
15, partially acetylated paper, pigmented paper containing titanium dioxide and others, α-olefin polymers (e.g., polyethylene, polypropylene, ethylene-butene copolymers, etc.). ) Coated paper, paper pre-treated with polyvinyl alcohol, conductive treated film or paper treated with metal thin film or carbon, gelatin-primed paper, glassine paper, ketone paper, other mapped overlay coated papers,
Paper with a hydrophilic surface such as clay or insolubilized casein or carboxymethyl cellulose, calendered paper, paper impregnated or surface coated with acidic polymers, etc. can be used. In addition, an aluminum plate having a polyacrylamide undercoat, an aluminum plate treated with a hydrophilic silicate, and a support having an undercoat layer in which a conductive metal layer is deposited by an electroless deposition method can also be used.

Further, if necessary, a suitable pattern can be imprinted on the side of the support coated with the photosensitive layer or on the back side not coated with the photosensitive layer. For example, this is necessary when applying to postcards and commuter passes. In addition to coating these supports with the various layers described above, the supports themselves can also contain some of the components.

Of course, when components are mixed into a support such as plastic, glass, or metal, there are many difficulties in fully demonstrating their functions, but for example, in the case of a paper-based support, Even if a certain component is mixed into the support (paper base material), it will exhibit the same effect as when it is present in a layer coated on the support. Whether the components are contained in the support or in the coating layer on the support can be easily carried out depending on various conditions such as the intention of the practitioner of the present invention and necessity and advantage in manufacturing. be able to. When coating the photosensitive layer composition on the support, the coating amount is such that the amount of silver of the organic silver salt and silver halide is approximately 0.0% per TrI of the support.
It is applied in an amount within the range of 2f7 to about 37, preferably about 0.3f to about 2f.

If the amount of silver applied is less than the lower limit of this range, the maximum density of the image to be formed will be low, and if the amount of silver is more than the upper limit, the maximum density of the image will not improve as if it were saturated. Only the cost of the product will increase. The method for preparing the heat-developable photosensitive material of the present invention is specifically as follows. That is, an organic silver salt is produced by reacting an organic silver salt-forming agent with a silver ion supplying agent, such as silver nitrate, by the various methods described above. Preparation conditions are usually under atmospheric pressure,
The temperature can be appropriately selected within the range of -15°C to +80°C. Usually, a temperature of about 20°C to about 60°C is suitable. After washing the organic silver salt thus prepared with water, alcohol, etc., it is dispersed in an emulsion binder. For dispersion, a colloid mill, mixer, ball mill, etc. can be used. It is usually carried out at room temperature (15°C to 25°C). A silver halide forming agent (N
-halogeno compound) is added to convert a portion of the organic silver salt to silver halide. The reaction temperature is suitably from room temperature to about 80°C, and the reaction time can be arbitrarily selected from about 1 minute to about 48 hours. Next, Seishu c) and (d) of the present invention
Add and heat. The temperature is suitably 25°C to 80°C, and the heating time is suitably between 5 minutes and 300 minutes. Next, various additives such as a sensitizing dye, a reducing agent, and a toning agent are sequentially added, preferably in the form of a solution. Normally room temperature ~ 50℃
While stirring at a temperature of .degree. C., the ingredients are added one after another at appropriate time intervals (usually 5 to 20 minutes). When all the additives have been added in this way, the coating liquid has been prepared. This coating solution is coated as it is on a suitable support without drying. As well as the heat-developable photosensitive layer formed by such an operation, an overcoat polymer layer,
The undercoat layer, back layer, and other layers can be formed by preparing coating solutions for each layer and sequentially applying them by various coating methods such as dipping, air knife, curtain coating, or hopper coating. can. Further, if necessary, see US Pat. No. 2,761,791 and British Patent No. 837.
It is also possible to apply two or more layers simultaneously by methods such as those described in No. 095. If desired,
Printing can be applied to the front or back side of the support, or a layer coated on the support, and can be applied to a vehicle ticket, postcard or other document according to a predetermined pattern. .

The photothermographic material thus produced is cut into a size suitable for use and then imagewise exposed.

If necessary, preheating (80° C. to 140° C.) may be applied before exposure. Light sources suitable for image exposure include various light sources such as tungsten lamps, fluorescent lamps for copying such as those used mainly for exposing diazo-sensitive materials, mercury lamps, iodine lamps, xenon lamps, CRT light sources, and laser light sources. The manuscript may include not only line images such as technical drawings, but also photographic images with gradation, and it is also possible to photograph images of people and landscapes using a camera. As for the printing method, contact printing may be performed overlapping the original, or enlarging printing may be performed. The amount of exposure varies depending on the sensitivity of the photosensitive material, but a high-sensitivity one requires about 10 lux seconds, and a low-sensitivity one requires about 104 lux seconds. The image-exposed sensitive material is heated (about 80°C to about 180°C, preferably about 1
00°C to about 150°C). The heating time is arbitrarily adjusted, such as from 1 second to 60 seconds. This is determined in relation to the heating temperature. Usually, suitable times are about 5 seconds to about 40 seconds at 120°C, about 2 seconds to about 20 seconds at 130°C, and about 1 second to about 10 seconds at 140°C. There are various means for heating, for example, the sensitive material may be brought into contact with a simple heated plate, it may be brought into contact with a heated drum, or in some cases, the material may be passed through a heated space. You can. Alternatively, heating may be performed by high frequency heating or laser beam as described in US Pat. No. 3,811,885. A deodorizing agent can also be applied after treatment to prevent odors generated during heating. Also, JP-A-50-252
As described in No. 3, some kind of fragrance can be included so that the odor of the photosensitive material is not detected. Generally, heat-developable photosensitive materials such as those of the present invention have the property that their photographic properties tend to deteriorate due to moisture.
It is desirable to have a desiccant present in the packaging as described in No. 23.

The composition for heat-developable photosensitive materials according to the present invention has the characteristics of extremely high sensitivity and very little fog, and is therefore extremely useful.

The present invention will be explained in detail below with reference to Examples.

Example 1 100 ml of an aqueous solution containing 1,97 ml of sodium hydroxide and 2 ml of toluene containing 127 lauric acid
00ml and emulsified using a homomixer.

50ml of an aqueous solution in which 8.57% of silver nitrate was dissolved in this emulsion
was added to form silver laurate. After removing the aqueous phase, the toluene phase (which contains silver laurate and silver bromide) was added to polyvinyl petite (1.5% by weight of Ral).
It was dispersed in isopropanol solution 1807 using a homogenizer. To this silver salt polymer dispersion 807 (approximately 1/60 mole of silver salt) was added 4 ml of a 1.1% by weight N-bromoacetamide solution in acetone, and the mixture was heated at 50° C. for 60 minutes. Next, after adding H2O2Oll to this, 3000r
The precipitate collected by centrifugation at pm for 30 minutes was dispersed with a homogenizer in 60 y of isopropanol solution containing 15% by weight polyvinyl butyral. Next, 20 ml of an acetone solution containing 0.5% acetamide was added to this, and 4x10-4% by weight of the following compound (1) was added.
After adding 5 ml of acetone solution and heating at 50° C. for 30 minutes, the mixture was returned to room temperature. This is called liquid A. Compound (1
) Solutions B to E were prepared in the same manner as Solution A, except for the differences shown in Table 1.

Next, while stirring the solutions A to E at 20 DEG C., the components were added to each solution one after another at intervals of 5 minutes to prepare a coating solution. The five types of coating solutions prepared in this way were applied on art paper at a silver content of 0.3 per ml. Apply it so that it becomes 4.
Various types of heat-developable photosensitive materials were created.

Sample A. B.. C. ．． Let them be D and E. These samples were exposed to light for 103 lux seconds through an optical wedge, and then developed by heating at a temperature of 140° C. for 8 seconds to obtain black images.

Next, the reflection density of this was measured.

The reciprocal of the exposure required to give a reflection density 0.1 above fog was chosen as a measure of sensitivity. Table 2 shows the measured values of relative sensitivity and heat fog when the sensitivity of sample B is set as 100. It is clear from Table 2 that the sensitization method of the present invention is superior.

Example 2 80 r of polymer dispersion of the laurate salt of Example 1 (approximately 1
/60 mol of silver salt) in acetone solution of 1.4% by weight N-bromosuccinimide 4! 6 at 45°C with addition of ILI.
Heated for 0 minutes.

Next, 25 ml of an acetone solution containing 0.5% acetamide was added, and 4×1 of compound (1) used in Example 1 was added.
Add 8 d of 0-4 wt% acetone solution and heat at 55°C for 20
After heating for a minute, it was returned to room temperature. Next, add H2O2 to this
After adding Od, the precipitate collected by centrifugation at 3000 rpm for 40 minutes was dispersed in 15% by weight polyvinyl butyral in isopropanol solution 601 using a homogenizer. This is called F solution. As comparative samples, Solutions G to J were prepared in the same manner as Solution F except for the differences shown in Table 3. Next, the same components as in Example 1 were added to each solution while stirring the E-1 solution at 20° C. to prepare a coating solution.

The five types of coating liquids thus prepared were applied under the same conditions as in Example 1 to produce five types of photothermographic materials.

These samples were subjected to sensitometry under the same conditions as in Example 1. The results are shown in Table 4. It is clear from Table 4 that the sensitization method of the present invention is superior. Comparative Example 1 Aqueous solution 100a in which 1.97% of sodium hydroxide was dissolved and toluene 200a in which 127% of lauric acid was dissolved! nl and emulsified using a homomixer.

12 ml of hydrobromic acid (0.4% aqueous solution) was added to this emulsion to emulsify it again. 50 ml of an aqueous solution containing 8.57 g of silver nitrate was added to this emulsion to simultaneously form silver laurate and silver bromide. After removing the aqueous phase, the toluene phase (
(containing silver laurate and silver bromide) was dispersed in a 1.5% by weight isopropanol solution 1807 of polyvinyl butyral using a homogenizer. This dispersion will hereinafter be referred to as a silver salt polymer dispersion. 0.5% by weight in this silver salt polymer liquid 807 (approximately 1/60 mole of silver salt)
Add 25 mj of acetamide acetone solution, then add 8 mj of a 4X10-4 wt% ethanol solution of the following compound (1).
After adding 1 and heating at 55° C. for 20 minutes, the mixture was returned to room temperature.

Chemical formula of compound (1) Next, after adding 0 ml of H2O2, the collected precipitate was centrifuged at 3000 rpm for 40 minutes, and the collected precipitate was dispersed in a 15% by weight polyvinyl butyral inpropanol solution 607 using a homogenizer.

This is called liquid K. As comparative samples, solutions L to M were prepared in the same manner as solution K except for the points shown in Table 5.
A sample prepared and coated with a coating liquid under the same conditions as Example 2 was
The results of sensitometry under the same conditions as Example 1 are shown in the sixth example.
Shown in the table.

It is clear from Tables 6 and 4 that the sensitization method of the present invention is superior.

Examples 3 to 7 Photothermographic materials NR were prepared in the same manner as in Example 2, except that the following compound was used in place of compound (1) in Example 2.

The amount of each compound added is shown with the amount of compound (1) in the F solution prepared in Comparative Example 1 being 1. Table 7 lists the sample preparation conditions. When each sample was subjected to sensitometry in the same manner as in Example 1, the results shown in Table 8 were obtained.

Examples 8 to 11 Samples SV were prepared by using butyramide, succinamide, dibenzamide, or prolactam in the same molar amount as acetamide in place of acetamide in Example 2.

The results of sensitometry under the same conditions as in Example 1 were
Shown in Table 0.

Example 12 Behenic acid 3 was added to 100 ml of benzene heated to 60°C.
．． 47 was dissolved and the temperature was adjusted to 60°C.

While stirring this solution with a stirrer, 100 ml of water was added to emulsify it. Next, aqueous ammonia was added to about 80 WLI of an aqueous solution containing 1.77 g of silver nitrate to obtain a silver ammine complex salt, and the aqueous solution (temperature: 10° C.), which was made up by adding water to make a total volume of 100 ml, was added to the above emulsion. In this way, microcrystals of silver behenate were obtained. This reaction mixture was kept at room temperature (25°C).
When the mixture was left to stand for 20 minutes, it was separated into an aqueous phase and a benzene layer.

Therefore, first, the aqueous phase was removed, and 400 ml of fresh water was added for washing by decantation. Next, 400 ml of methanol was added and silver behenate was collected by centrifugation. A spindle-shaped silver behenate 4y having a long side of approximately 1 micron and a short side of approximately 0.05 micron was obtained. The thus obtained silver behenate 2.37 (approximately 1/200 molar amount) was added to 20 ml of an ethanol solution containing 2.57 mol of polyvinyl butyral.
The mixture was dispersed in E for 1 hour using a ball mill.

A 1.0% by weight acetone solution of N-bromphthalazinone (halogen-containing compound) 3 was added to this polymer dispersion of organic silver salt.
me was added and heated at a temperature of 65° C. for 20 minutes. Add to this polymer dispersion 3 ml of a 5X10-4% acetone solution of the following compound () and 1 ml of a 2% acetone solution of acetamide.
0ml was added and heated at a temperature of 50°C for 40 minutes.

This is called W liquid. Compound () Next, for comparison, Solution X was prepared in exactly the same manner as in the preparation of Solution W, except that acetamide and Compound () were not added.

Claims (1)

[Scope of Claims] 1. A heat developable product containing at least (a) an organic silver salt and (b) a photosensitive silver halide formed by decomposing an N-halogeno compound in the presence of the organic silver salt. The composition for photosensitive materials is heated in the presence of (c) a compound having -CONH- units and (d) a sulfur-containing organic compound selected from the following compounds (1) or (2) before coating. A method for sensitizing compositions for heat-developable photosensitive materials. (1) An organic compound having -CS-NR_1- units in the molecule (where R_1 is a hydrogen atom or has a carbon atom number of 12
(represents the following carbon-containing substituents) (2) Organic compounds represented by the following general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (However, R_1_5, R_1_6, R_1_7 and R_1_8 are each hydrogen atom or carbon number 12 or less carbon-containing substituents).