JPS5913013B2 - Method for producing composition for heat-developable photosensitive material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 5 The present invention relates to a method for producing a composition for a heat-developable photosensitive material, and particularly to a method for producing a sensitized composition.

Photography using silver halide has superior photographic properties such as sensitivity and gradation of 10 compared to methods such as electrophotography and diazo photography, so it is the most widely used photographic method. be.

However, the silver halide photosensitive material used in this silver halide photography method is developed with a developer after image exposure, and then the resulting image is processed in a normal indoor room.
Several liquid treatments such as stopping, fixing, washing, or stabilization are performed to prevent discoloration or fading under light, or to prevent undeveloped white areas (background) from turning black. . Therefore, such processing is time-consuming and labor-intensive, and there are dangers to the human body due to the handling of chemicals, contamination of the processing room, the bodies and clothes of workers, and furthermore, there are risks when the processing liquid is discharged into rivers. There are many problems such as pollution. Therefore, in high-sensitivity photographic materials using silver halide, it is possible to process them dryly without liquid processing, and the processed image is stable, and the background does not change color under normal room light. There has been a demand for a photosensitive material that can be dry-processed with less irradiation. For this reason, various efforts have been made up to now. For example, West German Patent No. 112320
As described in specifications such as No. 3 and No. 301174157, by incorporating a 3-pyrazolidone developing agent into a silver halide emulsion, it becomes possible to develop the emulsion by heating, and furthermore, in this case, West German Patent No. 1175075 describes that the reaction is accelerated when a substance that donates moisture is present during heating35.
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 the photosensitive material is 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. Currently, the most successful material in the field of photosensitive materials capable of forming photographic images using such a dry processing method is U.S. Pat. No. 31,529.
This is a heat-developable photosensitive material using a composition containing as essential components a silver salt of an organic acid, a small amount of silver halide, and a reducing agent described in the specifications of No. 04 and No. 3457075.

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 only a small amount of silver halide is used, and most of it consists of stable white or light-colored organic silver salts that do not easily darken when exposed to light. This is because the color appears white or light colored as a whole, so such slight discoloration hardly bothers the 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 100°C.
When heated above ℃, the organic silver salt oxidizing agent and reducing agent in the photosensitive layer undergo an oxidation-reduction 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, liquid processing (wet processing) is used for silver halide photosensitive materials, in which trace amounts of physically unstable sulfur-containing compounds, selenium-containing compounds, or tellurium-containing compounds are included in the composition of the photosensitive layer. Sensitization of the composition for the layer is often carried out, for example, as 1 chemical sensitization. For more information on these techniques, see “The OryOfPhOt”.
OgraphicPrOcess22 3rd edition (1966
(Published by Macmillan), pages 114 to 116, and "PhOtOgraphicEmulsiOn"
Chemistryn (1966 Focal Pres.
(published by 8 companies), pages 83 to 98, US Patent No. 15749
No. 44, No. 1623499, No. 2278947, No. 2399083, No. 2410689, No. 2440206, No. 2449153, No. 318
No. 9458, No. 3297446, No. 329744
7, the specifications of the same No. 3501313, the specifications of the British patent No. 1129356, the specifications of the West German patent No. 971436, the West German patent No. 1422869, the specifications of the West German patent no.
No. 2059245, No. 2064204, Pelkey National Patent No. 624013, and Japanese Patent Application Laid-Open No. 1983-5887.

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 producing a sensitized composition for photothermographic materials.

More specifically, it is an object of the present invention to provide a method for producing a composition for a photothermographic material sensitized with 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 on 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 the "gold sensitization" method using a gold compound, which is commonly known as a sensitization method for wet photosensitive materials, and the sensitization method using a palladium compound cannot sensitize the photosensitive layer of a heat-developable photosensitive material. I couldn't do it. 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 have developed a method using a sulfur-containing compound and C which are known as sensitizers for wet-type silver halide photographic materials, which are not generally accepted.
It was discovered that a composition for a photothermographic material can be sensitized by using a compound having one -N unit in combination and performing preheating treatment, leading to the present invention.

That is, the present invention provides at least (a) an organic silver salt and (b)
A method of heating a composition for a heat-developable photosensitive material comprising a photosensitive silver halide in the presence of (c) at least one compound having a -CONH unit and (e) a sulfur-containing organic compound before coating. This is a method for producing a composition for developing photosensitive materials. 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 that is relatively stable to light, and is preferably heated at a temperature of 80°C or higher in the presence of photosensitive silver halide. When heated to 100°C or higher, it reacts with a reducing agent to produce silver (image).

Suitable examples of such organic silver salts include silver salts of organic compounds having an imino group, mercapto group, thione group, or carboxyl group, and other silver salts described below. Specific examples include (1) Examples of silver salts of organic compounds having imino groups:
benzotriazole silver, nitrobenzotriazole silver,
Alkyl-substituted benzotriazole silver such as methylbenzotriazole silver, halogen-substituted benzotriazole silver such as bromobenzotriazole silver, chlorobenzotriazole silver, e.g. carboimide-substituted benzotriazole silver such as benzimidazole silver, e.g. - Substituted benzimidazole silver such as chlorobenzimidazole silver and 5-nitrobenzimidazole silver, carbazole silver, saccharin silver, phthalazinone silver, substituted phthalazinone silver, silver salts of phthalimides, pyrrolidone silver, tetrazole silver, imidazole silver, etc. (2
) Silver salt of a compound having a mercapto group or a thione group: 3
- silver salt of mercapto-4-phenyl-1,2,4-triazole, silver salt of 2-mercapto-benzimidazole, silver salt of 2-mercapto-5-aminothiadiazole,
Silver salt of 1-phenyl-5-mercaptotetrazole, 2
- silver salt of mercaptobenzothiazole, silver salt of 2-(s-ethylthioglycolamido)benzthiazole, s
Alkyl (alkyl group having 12 to 22 carbon atoms) silver thioglycolate, silver salts of thioglycolic acid such as the silver salts described in JP-A No. 48-28221, silver salts of dithioacetic acid, etc. Silver salts of thiocarboxylic acids, silver thioamides, silver salts of thiopyridines such as silver salts of 5-carbetoxy-1-1-methyl-2-phenyl-4-thiopyridine, silver salts of dithiodihydroxybenzole, silver salts of mercaptotriazine, 2-mercapto. Silver salts of benzoxazole, silver salts of mercaptooxadiazole, etc. (3) Organic silver salts having a carboxyl group: (a) Silver salts of aliphatic carboxylic acids; silver purinate, silver laurate, silver myristate, Silver palmitate, silver stearate, silver behenate, silver maleate, silver fumarate, silver tartrate, silver furoate, silver linoleate, silver oleate, silver hydroxystearate,
Silver adipate, silver sebacate, silver succinate, silver acetate, silver butyrate, silver camphorate, etc.

Among these, silver salts of aliphatic monocarboxylic acids having 10 or more carbon atoms are particularly preferred in the present invention. (mouth) Silver aromatic carboxylate Others: silver benzoate, silver 3,5-dihydroxybenzoate, silver o-methylbenzoate, silver m-methylbenzoate,
Silver p-methylbenzoate, Silver 2,4-dichlorobenzoate,
Substituted silver benzoates such as silver acetamidobenzoate, silver p-phenylbenzoate, silver gallate, silver tannate, silver phthalate, silver terephthalate, silver salicylate, silver phenyl acetate, silver pyromellitate, 4'-n- Silver salts of octadecyloxydiphenyl-4-carboxylic acid, e.g., U.S. Pat.
(4) other silvers, such as silver thionecarboxylic acids as described in US Pat. Salt: 4-hydroxy-6-methyl-1,3,3a-J-tetrazaindene silver salt, 5-methyl-J-methyl-1,2,3,
Silver salt of 4,6-pentazaindene, British Patent No. 1230
Silver salts of tetrazaindene as described in US Pat. No. 642, silver s-2-aminophenylthiosulfate as described in US Pat. No. 3,549,379, British Patent No. 1,346,595 metallized amino alcohols, such as those described in U.S. Pat. No. 3,794,496.
Examples include organic acid metal chelates as described in the specification of the present invention.

Further, if necessary, an oxidizing agent other than a silver salt, such as titanium oxide, zinc oxide, gold carboxylate such as gold laurate, gold stearate, and gold behenate, may be used in combination with the above-mentioned organic silver salt. There are various methods for preparing such organic silver salts, the simplest of which is described in U.S. Pat. No. 345
As described in the specification of No. 7075, a solution of an organic silver salt forming agent or its salt dissolved in a solvent mixed with water such as alcohol or acetone or water is mixed with an aqueous solution of a water-soluble silver salt such as silver nitrate. This is a method for preparing organic silver salts.

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. Other methods include those described in US Pat. No. 3,458,544. 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.
Similar to this, a method for obtaining organic silver salts that are more stable against heat and light was published in Japanese Patent Publication No. 44-3.
It is described in Publication No. 0270 and the like. This is a method in which a solution of a silver compound without using alkali, such as a simple aqueous solution of silver nitrate, is used 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 is an aqueous solution of an alkali metal salt or ammonium salt of a water-soluble organic silver salt forming agent and an oil (e.g.
Emulsions with benzene, toluene, cyclohexane, pentane, hexane, carboxylic esters such as acetate, phosphoric esters, oils such as castor oil, etc.) and silver salts (such as silver nitrate) and silver that are more easily soluble than organic silver salts. This is a method of preparing an organic silver salt by mixing a complex salt, preferably as an aqueous solution thereof. Another method of this method is to mix and emulsify an aqueous alkaline solution and an oil-soluble solution of an organic silver salt forming agent (for example, a toluene solution), and mix this with an easily soluble silver salt such as silver nitrate or a silver complex salt such as a silver ammine complex salt. An organic silver salt can also be prepared by mixing with an aqueous solution. 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, acetate esters such as amyl acetate, isopropyl acetate, isoamyl acetate, ethyl acetate, 2-ethylbutyl acetate, butyl acetate, propyl acetate: dioctyl sebacate, dibutyl sebacate,
Sebacic acid esters such as 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: Tartrate esters such as diethyl tartrate; methyl butyrate, ethyl butyrate,
Butyrate esters such as butyl butyrate and isoamyl butyrate; adipate esters; (4) Oils such as castor oil, cottonseed oil, linseed oil, and 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 such as silver ammine complex salts, silver methylamine complex salts, silver ethylamine complex salts, etc., preferably organic silver salts; An alkali-soluble silver complex salt having a high dissociation constant is also used. 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. Also, West German Patent Publication No. 24011
As described in No. 59, ultrasonic waves can also 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.
Special methods include, for example, US Pat. No. 3,700,458.
As described in the specification, a non-aqueous solution of an organic carboxylic acid and a non-aqueous solution of a heavy metal salt of trifluoroacetate or tetrafluoroborate are mixed in the presence of a polymer to form a compound such as a silver salt of an organic carboxylic acid. Methods of making heavy metal salts are known. Additionally, U.S. Patent No. 3,748,143
The patent specification also describes a similar emulsion manufacturing method using a non-aqueous solution. Also, JP-A-49-13224, JP-A No. 51
-22430 (Japanese Unexamined Patent Publication No. 5122430) and West German Patent Publication No. 2322096, when preparing organic silver salts, metal salts such as chromium, mercury, and lead compounds are used. The presence of metal complexes can also change the particle morphology, particle size, and photographic properties of the organic silver salt, such as thermal fog, photostability, sensitivity, and the like.

In addition to the above-mentioned mercury and lead, cobalt, manganese, nickel, iron, and chromium 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 is preferably in the range of about 10-6 to about 10-1 mole per mole of organic silver salt, and about 10-5 to 10-2 mole per mole of silver halide. The particle size of the organic silver salt produced in this way has a major axis of about 10 microns to about 0.01 microns,
Preferably from 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 any of these. It is a mixture of The amount used ranges from about 0.001 mole to about 0.5 mole, preferably from about 0.01 mole to about 0.3 mole per mole of organic silver salt.

The photosensitive silver halide may be of coarse grain or fine grain, but fine grain is preferable. The preferred grain size of silver halide is a major axis of about 0.5 microns to about 0.005 microns.
microns, preferably about 0.3 microns to about 0.02 microns. When the grain size of the photosensitive silver halide is too small, the efficiency of sensitization according to the present invention described below will be low, and when the grain size is too large, the combination of (a) organic silver salt and (5)
) Since contact with photosensitive silver halide 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 photosensitive silver halide is prepared as an emulsion by any method known in the photographic field, such as a single jet method or a double jet method. Examples include Lipman emulsion and ammonia method emulsion. The silver halide emulsion that can be used in the present invention may be an unwashed emulsion, or it may be one that has been washed with water, alcohol, or the like to remove soluble salts.
The photosensitive silver halide prepared in advance in this way is
It is mixed with a redox composition consisting of an organic silver salt and a reducing agent. This is described in US Pat. No. 3,152,904. However, as described in U.S. Pat. No. 3,457,075, it is clear that the contact between the silver halide and the organic silver salt is insufficient and satisfactory photosensitivity cannot be obtained using this method. It became.

Therefore, various efforts have been made to ensure sufficient contact between silver halide and organic silver salt. One of these is a technique in which a surfactant is present in a coating solution for forming a photosensitive layer; an example of this is JP-A-50-329
No. 26 and No. 50-32928. Another method is to mix silver halide prepared in a polymer with an organic silver salt; for example, U.S. Pat.
No. 706564, No. 3761273, U.S. Patent No. 1
354186, French Patent No. 2078586, and British Patent No. 1362970.

The silver halide used in the present invention is, for example,
It can also be prepared almost simultaneously with the production of organic silver salts, as described in US Pat. 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. Alternatively, a photosensitive silver halide forming component (described later) may be applied to a solution or dispersion of an organic silver salt prepared in advance to form a photosensitive silver halide on a portion of the organic silver salt. The silver halide formed in this way is in effective contact with the organic silver salt and exhibits a favorable effect, as disclosed in US Patent No. 34.
It is described in the specification of No. 57075. On the other hand, components that can form photosensitive silver halide are compounds that act on organic silver salts to produce silver halide.Which compounds fall under this category and are effective can be determined simply as follows. This can be determined by testing. That is, the organic silver salt is treated with a silver halide-forming component, heated if necessary, and then examined by X-ray diffraction to determine whether silver halide has a unique diffraction peak. Specific examples of components capable of forming photosensitive silver halide include the following types of compounds. (1) Inorganic halide: For example, a halide represented by MXn (here, H.NH4 and a metal atom, X is CllBr and 1..n is M is H, .NH4
When , it is 1, and when M is a metal atom, it shows its valence. Metal atoms include lithium, sodium, potassium, rubidium, cesium, copper, gold, beryllium, magnesium, calcium, strontium, barium, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, and antimony. ,
Bismuth, chromium, molybdenum, tungsten, manganese, rhenium, iron, cobalt, nickel, ruthenium,
Examples include rhodium, palladium, osmium, iridium, and platinum. ) (2) Containing...rogen metal chains: for example, K
2PtCl6, K2PtBr6, HAl)Cl4, (N
H4)21rC16, (NII4)31rC16, (N
Fl4)2RuC16, (NH4)3RuC16, (N
Examples include Fl4)3RhC16 and (NH4)3RhBr6. (3) Onium halides: quaternary ammonium halides such as trimethylphenylammonium bromide, cetylethyldimethylammonium bromide, trimethylbenzylammonium bromide; quaternary phosphonium halides such as tetraethylphosphonium bromide; Examples include tertiary sulfonium halides such as trimethylsulfonium iodide. These onium halides may also be used in the final coating dispersion for the purpose of reducing sensitivity and possibly background concentration. This is described, for example, in US Pat. No. 3,679,422. Further, as described in JP-A No. 49-84443, by using an onium salt halide-based conductive polymer, it is also possible to make a heat-developable photosensitive and electrosensitive material. (4) Halogenated hydrocarbons: Examples include iodoform, bromoform, carbon tetrabromide, and 2-bromo-2-methylpropane. (5) Other halogen-containing compounds: Examples include triphenylmethyl chloride, triphenylmethyl bromide, 2-bromobutyric acid, 2-bromoethanol, and benzophenone dichloride. In the previous method and this method, after adding the silver halide forming component, the temperature is at room temperature to high temperature (
By aging at 30° C. to 8°C for an appropriate period of time (for example, 20 minutes to 48 hours), improvements in photographic properties such as increased sensitivity and reduced heat fog can be achieved. These silver halide forming components can be used alone or in combination of two or more. The amount used ranges from about 0.001 mole to about 0.5 mole, preferably from about 0.01 mole to about 0.3 mole, per mole of the organic silver salt of component (a). If the amount is less than the above lower limit, the sensitivity will be low, and if the amount is more than the above upper limit, photodiscoloration (undesirable coloring of the background portion that occurs when the processed photosensitive material is left under room light) will increase. One of the most characteristic components in the present invention, which is used to sensitize a composition for a heat-developable photosensitive material comprising at least (a) an organic silver salt and (b) a photosensitive silver halide as described above. It is.

As the compound having one -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, and an indoline 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 preferably has 1 to 18 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, 2-ethylhexyl, octyl, nanyl, decyl, dodecyl, etc. Those having 1 to 8 carbon atoms are more preferred. Aryl groups include unsubstituted and substituent groups (for example, alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, etc., such as 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, putoxy, 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 The flow-containing yellow organic compound used in the present invention includes various compounds.

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; substituted or unsubstituted aryl groups such as phenyl, tolyl, and carboxyphenyl; acyl groups such as acetyl and propionyl; and the like.
) (11) Specific examples of organic compound (1) 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), R4, R5, R6, R7, R8, R9, RlO, R
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) Compounds 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. Examples of the heterocycle constituted by these atomic groups include an oxazolidine ring, a thiazolidine ring, an imidazolidine ring, an isoxazolidine ring, a pyrazolidine ring, an isothiazolidine ring, and a tetrahydrotriazole ring, which constitute preferred compounds. 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,
Examples of carboxyphenylethylidene include substituted or unsubstituted alkylidene groups, phenyl groups, tolyl groups, substituted or unsubstituted aryl groups such as carboxyphenyl groups, and arylidene groups such as benzylidene groups, trilidene groups, and carboxybenzylidene groups. 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 Rl, , Rl6, Rl7 and R, 8 each represent a hydrogen atom or a carbon-containing substituent having 12 or less carbon atoms).

Preferred groups constituting the compound are substituted or unsubstituted alkyl groups such as methyl, ethyl, propyl, 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 components (c) and (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 steps. In other words, it is sufficient that component (c) and component (d) are present in the prepared product. Component (a)
It is particularly preferable for the present invention to add component (d) to a mixture of component (5) and component (5) because the sensitization efficiency is high. -CONH
When a compound having one unit is added, the amount thereof is about 0.001 mol to about 2 mol, preferably about 0.005 to about 1 mol, per mol of the organic silver salt of component (a). It is.

If the amount added is too large, the amount of components other than the image forming components will be too large, which is undesirable and makes it difficult to obtain an image with high Drrlax.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 10-2 mol to 10-10 mol, preferably 10-1 mol per mol of the organic silver salt of a).
It is used in amounts ranging from 4 moles to 10-8 moles.

If the amount of the sulfur-containing organic compound added is too large, thermal fogging will increase, and if it is too small, the sensitizing effect will be small. At least the product a), component (b), prepared in this way,
The composition containing component (c) and component (d) is sensitized by heating it prior to its application.

It is also preferred to heat the composition comprising component (a), component (b), component (c) and component (6) after preparing component (a) and component (5). Heating is at a temperature in the range of about 25°C to 80°C, preferably in the range of 30°C 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 (component (e)). The reducing agent is one that is capable of reducing the organic silver salt (component (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 component (e) reducing agent used in the present invention is:
When heated in the presence of exposed silver halide,
It is capable of reducing organic silver salt (component (a)).

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, e.g.
? 2,4-diaminophenol, methylaminophenol, p-aminophenol, o-aminophenol, 2
-Methoxy-4-aminophenol, 2-β-hydroxyethyl-4-aminophenol, etc.: Alkyl-substituted phenols, such as p-t-butylphenol, p-t
-amylphenol, p-cresol, 2,6-di-t
-butyl-p-cresol, p-ethylphenol, p
-Sec-butylphenol, 52,3-dimethylphenol, 3,4-xylenol, 2,4-xylenol, 2,4-di-t-butylphenol, 2,4,5-trimethylphenol, p-nonylphenol, p-octylphenol, etc.; aryl substituted phenols,
For example, p-phenylphenol, 0-phenylphenol, α-phenyl-0-cresol, etc.; other phenols, such as p-acetophenol, p-acetoacetyl-4methylphenol, 1,4-dimethoxyphenol, 2,6-dimethoxyphenol, chlorthymol, 3,5-di-t-butyl-4-hydroxybenzyldimethylamine, sulfonamidophenols such as those described in U.S. Pat. No. 3,801,321; and a novolak resin reaction product with a phenol derivative (e.g. 4-methoxyphenol, m-cresol, 0 or pt-butylphenol, 2,6-di-t-butylphenol and mixtures thereof); (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; Screw (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-bis(5
-chloro-2-hydroxyphenyl)methane, 2,2'
-Methylenebis[4-methyl-6-(1-methylcyclohexyl)phenol], 1●1-bis-(2-hydroxy-3,5-dimethylphenyl)-2methylpropane, 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-butylpheno(h)-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; p-
Bisphenols, such as bisphenol Al4.4
'-Methylenebis(3-methyl-5-t-butylphenol), 4,l-methylenebis(2,6-di-t-butylphenol), 3,3',5,5'-tetra-t-butyl- 4,4'-dihydroxybiphenyl, 4,4'-
Dihydroxybiphenyl, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2bis(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(4hydroxy-3,5-di-t-
butylphenylthio)propane, 4,47-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), 4,4'-ethylidene-bis-(6-t-butyl-0-cresol), 4,4
'-ethylidene-bis-(2-t-amylphenol)
, 4.4'-(p-chlorobenzylidene)-di-(2.
6-xylenol), 4,4'-ethylidene bis-(
2-cyclohexylphenol), 4,4'-pentylidene-di-(0-cresol), 4,4'-(p-bromo-benzylidene)-diphenol, 4,4'-propylidene-bis-(2-phenol), enylphenol), 4.l
-ethylidene (2,6-xylenol), 4,4
″-Heptylidene (0-cresol), 4・4′
-ethylidene-bis-(2,6-di-t-butylphenol), 4,4'-(2-butenylidene)-di-(2,
6-xylenol), 4.l-(p-methylbenzylidene)-di-(0-cresol), 4.4'-(p-methoxybenzylidene)-bis-(2.6-di-t-butylphenol) , 4,4'-(p-nitrobenzylidene)
-di-(2,6-xylenol), 4,4'Z-(p-
hydroxybenzylidene)-di-(0-cresol);
Others, for example, 3,5-di-t-butyl-4-hydroxybenzyldimethylamine, α-α7-(3,5-di-t-butyl-4-hydroxyphenyl)-dimethylether, 2,4・6-tris(3,5-di-t-butyl-4-hydroxybenzyl)phenol, N-N'
-di(4-hydroxyphenyl)urea, tetra-scratch [
Methylene mono(3,5-di-t-butyl-4-hydroxyhydrocinnamate).' Polyphenols such as methane, diethylstilbestrol, hexestrol, bis-(3,5-di-t-butyl -4-hydroxybenzyl) monoether, 2,6-bis(2'-hydroxy-3'-t-butyl-5'-methylbenzyl)5-4-
Examples include methylphenol.

(3) Substituted or unsubstituted mono- or bisnaphthols and di- or polyhydroxynaphthalenes: bis-β-naphthols, e.g. 2·l-dihydroxy-1·1′-
hinabutyl, 6,6'-dibutyl, 2,2'-dihydroxy-1,1'-hinabutyl, 6,6'-dinitro-2,2'-dihydroxy-1,1'-hinabutyl, bis(2- hydroxy-1-naphthyl)methane, 4,4'
-dimethoxy-1,1-dihydroxy-2,2'-hinabutyl; naphthols, such as α-naphthol, β-
naphthol, 1-hydroxy-4-aminonaphthalene,
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, 1-amino-2-naphthol-6
-sodium sulfonate, 1-naphthylamine-J[sulfonic acid, sulfonamide naphthols, such as those described in U.S. Pat. No. 3,801,321; 4) di- or polyhydroxybenzenes and hydroxy monoethers; Hydroquinone; Alkyl-substituted hydroquinone, such as methylhydroquinone, t-butylhydroquinone, 2,5-dimethylhydroquinone, 2
-6-dimethylhydroquinone, t-octylhydroquinone, etc.: Halogeno-substituted hydroquinones, such as chlorohydroquinone, dichlorohydroquinone, bromohydroquinone, etc.: Alkoxy-substituted hydroquinones, such as methoxyhydroquinone, ethoxyhydroquinone; Other substituted hydroquinones, such as phenylhydroquinone , hydroquinone monosulfonate; hydroquinone 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, pyrogallol,
Resorcin, 1-chloro-2,4-dihydroxybenzene, 3,5-di-t-butyl-2,6-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,4-dihydroxyphenyl sulfide, gallic acid Methyl acid, propyl gallate, etc.]) Ascorbic acid and its derivatives:
l-Ascorbic acid: isoascorbic acid; monoesters of ascorbic acid, such as monolaurate, monomyristate, monopalmitate, monostearate, monobehenate, etc. of ascorbic acid; diesters of ascorbic acid, such as ascorbic acid Acids dilaurate, dimyristate, dipalmitate, distearate, etc.: U.S. patent no.
Those described in No. 53337342 can also be used.

(6) 3-pyrazolidones and pyrazolones; for example, 1-phenyl-3-pyrazolidone, 4-methyl-4-
(7) Reducing saccharide: glycose , lactose, etc.

(8) Phenylenediamines: N-N'-diethyl-p
N-N-dialkyl-p-phenylene diamines such as -phenyl diamine, N-phenyl-N/-isopropyl-p-phenylene diamine, and the like. This kind is particularly known in US Pat. No. 3,531,286 and US Pat.
Color images can be obtained in combination with phenolic or active methylene color couplers such as those described in No. 328. Similarly, U.S. Pat.
Color images can also be obtained by the method disclosed in No. 61270. (
9) Hydroxylamines: For example, N-N-di(2-
ethoxyethyl) hydroxylamine, etc.

σ0) Reductones: e.g. anhydrodihydroaminohexose reductones as described in U.S. Pat. No. 3,679,426, linear aminooles as described in Pelkey Patent No. 786,086. such as dactons.

(Own) Hydroxamic acids: For example, U.S. Patent No. 37
Hydrooxamic acids such as those described in the specifications of No. 51252 and No. 3751255.

A2 hydrazides: for example, hydroxy-substituted fatty acid aryl hydrazides as described in US Pat. No. 3,782,949.

(Others): Pyrazolone-5-ones as described in U.S. Patent No. 3,770,448, at least one hydrogen atom at the 2-position as described in U.S. Pat. No. 3,773,512. Indan 1.3
-Diones, amidoximes as described in U.S. Pat. No. 3,794,488; kojic acid, hinokitiol, hydroxytetronic acid, hydroxytetronamides, sulfhydroxamic acids, p-oxyphenylglycine; others For specific examples of the reducing agent used in the present invention, see JP-A-51-23721 and JP-A-5132.
No. 324, No. 51-51933, U.S. Patent No. 3152
No. 904, No. 3457075, No. 3531286
No. 3615533, No. 3679426, No. 3672904, No. 3751252, No. 37
No. 51255, No. 3782949, No. 37704
No. 48, No. 3773512, No. 3819382, No. 3839048, Pelkey Patent No. 786086
No., West German Patent Application Publication No. 2308766, West German Patent Application No. 2319080, and West German Patent Application No. 2321328.

Among the above reducing agents, for example, a methyl group is present in at least one of both substitution positions adjacent to the hydroxyl substitution position of the aromatic nucleus.
mono-, bis-, having an alkyl group or acyl group such as ethyl, propyl, isopropyl or butyl, e.g. 2,6-di-t-butylphenol;
Tris- or tetrakis-phenols are stable to light and have the advantage of being less prone to photodiscoloration.

Furthermore, as described in U.S. Pat. No. 3,827,889, if the reducing agent is photodegradable or is inactivated by light, it will 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. No. 3,756,829 and U.S. Pat. No. 3,827,889, a heat-developable photosensitive material is prepared using such a photodegradable reducing agent, and the reducing agent is destroyed by exposing it to light in an imagewise manner. It is also possible to directly obtain a positive image.

Furthermore, a compound that promotes the optical decomposition of the reducing agent can be used in combination. Further, for example, US Pat. No. 3,589,903 and US Pat.
No. 6829, JP-A-50-36110, JP-A No. 50-11
No. 6023, No. 51-51933, No. 51-2372
It is also possible to use reducing agents such as blocked bisphenol compounds as described in the specifications of No. 1 and No. 51-32324. One of the preferred reducing agents is an ester of a carboxylic acid derived from a phenol substituted product having a substituent at the 1-ortho position and a monohydric or polyhydric alcohol or a phenol, and a polyhydric alcohol having a substituent at the 2-ortho position. Examples include at least one ester selected from the group consisting of esters of mono- or polycarboxylic acids and alcohols derived from phenol or phenol substituted products substituted with bulky groups at the ortho position. More specific examples of this compound include (where z is a divalent bonding group consisting of 30 or less carbon atoms, R1 is an alkyl group having 1 to 20 carbon atoms, R2 is H or R3 represents an alcohol residue, R4 represents a carboxylic acid residue, and m and n each represent a natural number not exceeding the valency of the alcohol and carboxylic acid.

) Compounds represented by the chemical formula are mentioned. Specific examples include tetra-scratch [methylene-(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]
] Methane and octadecyl-3-(3',5'-di-t-
butyl-4'-hydroxyphenyl) propionate. Among these esters, phthalazinone can be added as a particularly preferred activator and toning agent to the compositions of the present invention, as described below, and is a reducing agent that, when combined with phthalazinone, provides high image density and favorable black tone. The agent was found to be a compound represented by the following general formula.

(Here, S is 1, 2, 3 or 4, and CSH2
S is a carbon atom connected to the phenyl nucleus having at least one hydrogen atom, R is a residue of a saturated acyclic aliphatic alcohol represented by CdH2d+2-t, and d is a natural number from 1 to 6. , t is a natural number from 1 to 4d.

) Examples of other preferred reducing agents include bisphenols having a 2,4-di-t-butylphenol group or a 2,4-di-t-amylphenol group.

An example is a compound of the following formula. In the formula, R1 and R2 represent a cyclohexyl group, a cyclopentyl group, a t-butyl group, or a t-amyl group, and R3 and R4 represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, an aryl group, a substituted aryl group, or an aralkyl group. represents a group. A suitable reducing agent depends on the type (performance) of the organic silver salt (component (a)) used.
are selected based on.

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 weak silver salts, 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. For silver behenate, bis(hydroxyphenyl)methane-based o-bisphenols,
There are many such as 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 varies depending on the type of organic silver salt, reducing agent, and other additives, but is generally about 0.05 mol to about 1 mol per mol of organic silver salt. 10 moles are suitable, preferably from about 0.1 to about 3 moles. 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 Japanese Patent Application No. 1983.
-27242, U.S. Patent No. 3667958, U.S. Patent No. 3
No. 751,249, a particularly effective reducing agent combination is a carboxylic acid derived from a phenol having a bulky ortho substituent and a monohydric or polyhydric alcohol or a phenol. ester,
or a polyhydric phenol having a bulky ortho substituent,
or an ester of an alcohol derived from a phenol having a bulky ortho substituent and a mono- or polycarboxylic acid; Alternatively, it can be used in combination with p-bisphenols.

In this combination example, reduction of heat fog, increase in whiteness,
Photostabilization after treatment is achieved. In addition, the combined use of two types of mono- or polyphenol reducing agents having alkyl groups at both substitution positions adjacent to the hydroxyl 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 10-3 to 0.8 mol may be used together. It is preferred to further use a toning agent together 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. Effective toning agents depend on the organic silver salt and reducing agent used, but the most common toning agents include heterocyclic organic toning agents containing at least two heteroatoms, such as those described in U.S. Pat. No. 3,080,254. A compound in which at least one nitrogen atom is present in the heterocycle. For example, phthalazone (phthalazinone), phthalic anhydride, 2-acetylphthalazinone, 2-phthalyl phthalazinone, patent application 1972-
Substituted phthalazinone as described in US Pat. No. 116,022, pyrazolin-5-ones as described in US Pat. No. 3,846,136; phthalimide, N-hydroxyphthalimide, N-potassium phthalimide,
Cyclic imides such as silver phthalate imide; quinazolinone; silver phthalazinone; and US Pat. No. 38321
Mercapto compounds described in JP-A No. 86 and JP-A-49-5020; JP-A-49-91215
No. and JP-A No. 1987-2524; phthalazinediones described in JP-A-50-67641; JP-A-Sho 50-
Uracils described in US Pat. No. 3,782,941;
-Hydroxynaphthalimides; substituted phthalimides described in West German Patent Application No. 2140406 and West German Patent Application No. 2141063; US Patent No. 38
Phthalazinone derivatives described in No. 44797 can also be used in the same manner as O. Additionally, U.S. Patent No. 38476
As described in No. 12, phthalic acid, naphthoic acid or phthalamic acid and imidazoles can also be used in combination.

Various methods are preferably applied to the photothermographic material prepared using the composition of the present invention in order to prevent thermal fogging.

One such method uses mercury compounds such as those described in US Pat. No. 3,589,903. Alternatively, a mercury compound can be used to directly obtain a positive image as described in US Pat. No. 3,589,901. Direct positive images can also be obtained by special layer configurations such as those described in US Pat. No. 3,607,282. Furthermore, for example, U.S. Patent No. 376,432
Mercury compounds can also be used in combination with color-forming couplers to produce stable color images, as described in US Pat. Furthermore, for example, Japanese Patent Application Laid-Open No. 48-4363
It is also possible to change the sensitivity and contrast by heating before image exposure, as described in Japanese Patent No. 0. A second method for preventing heat fogging is disclosed in Japanese Patent Application Laid-Open No. 49-10724, West German Patent Application Publication No. 2402161 and West German Patent Application No. 2364630, and Japanese Patent Application Laid-open No. 5
As described in each specification of No. 1-23522, for example, N-halogeno compounds such as N-halogenosuccinimide and N-halogenoacetamide can also be used. N-halogeno compounds such as N-halogenoxazolinone, N-halogenobenzotriazole, and N-halogenobenzimidazole can be used as well. Other methods for preventing heat fog include, for example, US Pat. No. 3,645.
No. 739, JP-A-49-125016, JP-A No. 49-13
Higher fatty acids such as lauric acid, myristic acid, balmitic acid, stearic acid, behenic acid, tetrahalogen Phthalic acid or its anhydride, arylsulfonic acids such as benzenesulfonic acid and p-toluenesulfonic acid, arylsulfinate acids such as benzenesulfinic acid and p-toluenesulfinic acid, or their salts, lithium myristate, stearic acid Salts such as lithium salts of higher fatty acids such as lithium, 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,
Alkyl-substituted benzoic acids such as p-acetamidobenzoic acid and p-t-butylbenzoic acid, phthalic acid, isophthalic acid, trimellitic acid, pyromellitic acid, diphenic acid, 5'
・5'-methylenebissalicylic acid is 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 effective in preventing heat fog include benzotriazole and its derivatives, mercapto compounds such as 1-phenyl-5-mercaptotetrazole, azole thioethers or blocked azolethiones, and Examples include peroxides and persulfates as described in Japanese Patent Application Laid-open No. 101019, and disulfides such as those described in Japanese Patent Application Laid-Open No. 51-42529.

Furthermore, when complex salts such as chromium salts, rhodium salts, copper salts, nickel salts, cobalt salts, rhodium, iron, cobalt, and palladium are coexisting during or before silver halide formation, heat fog can be prevented and sensitized. It is effective for improving photographic properties such as Furthermore, some optical sensitizing dyes that are said to be effective for gelatin silver halide emulsions also exhibit a sensitizing effect on the heat-developable light-sensitive material of the present invention.

Effective optical sensitizing dyes include cyanine, merocyanine, complex (trinuclear or tetranuclear) cyanine, holopolar cyanine, styryl, hemicyanine, oxonol, hemioxonol, and the like. Among the cyanine pigments, thiazoline nucleus, oxazoline nucleus, pyrroline nucleus, pyridine nucleus, oxazole nucleus, thiazole nucleus, . Those having a basic nucleus such as a selenazole nucleus or an imidazole nucleus are more preferable. Such a nucleus may contain an alkyl group, an alkylene group, a hydroxyalkyl group, a sulfoalkyl group, a carboxyalkyl group, an aminoalkyl group or an enamine group capable of forming a fused carbocyclic or heterocyclic ring. good. The chemical structure may be symmetrical or asymmetrical, and the methine chain may have an alkyl group, phenyl group, enamine group, or heterocyclic substituent. In particular, cyanine dyes having a carboxyl group are effective for sensitization.
In addition to the above-mentioned basic nucleus, merocyanine dyes include, for example, thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus,
It may have an acidic nucleus such as a thiazolidinedione nucleus, a barbituric acid nucleus, a thiazolion nucleus, a malononitrile nucleus, or a pyrazolone nucleus. These acidic nuclei further include alkyl groups, alkylene groups, phenyl groups, carboxyalkyl groups,
It may be substituted with a sulfoalkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an alkylamine group, or a hexerocyclic 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, supersensitizing additives that do not absorb visible light, such as ascorbic acid derivatives, azaindene, cadmium salts, organic sulfonic acids, etc., as described in U.S. Pat. Can be used together. Particularly effective sensitizing dyes for the heat-developable photosensitive material of the present invention include rhodanine nuclei, thiohydantoin nuclei, or 2-thio-2,4-oxazolidinedione as described in U.S. Pat. No. 3,761,279. Merocyanine dyes with a nucleus, such as 3-p-carboxyphenyl-5-[β-ethyl-2(3-benzoxazolylidene) ethylidene] rhodanine, 5-[(3β-carpoxyethyl-2(3-thiazolinyl) rden)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-benzoxazolinidene)1-
Methyl-ethylidene]-3-[(3-pyrrolin-1-yl)propyl]rhodanine, 3-ethyl-5-[(3-ethyl-2(3H)-benzothiazolylidene)isopropylidene]-2-thio 2,4-oxazolidinedione is mentioned. 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, and JP-A-49-17719. A sensitizing dye mainly for silver iodide described in JP-A No. 4
styrylquinoline dyes as described in JP-A No. 9-84637; tananine dyes as described in JP-A-49-105524; and JP-A-49-105524.
No. 96717, JP-A-49-102328, JP-A-5
0-2924 and 50-29029, for example, acidic dyes such as 27·τ-dichlorofluorescein dye, JP-A-50-104
No. 637, No. 50-105127, No. 51-2792
Merocyanine dyes such as those described in the specifications of No. 4 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 dyes added is about 10@-4 mol to about 1 mol per mol of silver halide or silver halide forming component of component (6).

Prevents photodiscoloration of processed photosensitive materials of heat-developable photosensitive materials containing the composition of the present invention in the photosensitive layer (a phenomenon in which unexposed areas of the photosensitive material gradually discolor due to light when exposed to room light after processing) For example, stabilizer precursors such as azole thioethers and blocked azolethiones as described in U.S. Pat. No. 3,839,041, as described in U.S. Pat. No. 3,700,457, Tetrazolylthio compound, US Pat. No. 3,824,103
It is possible to use S-carbamoyl compounds such as those described in US Pat.

In addition, light-absorbing dyes such as those described in Japanese Patent Publication No. 48-33692 can be used, particularly in film sensitive materials, in order to improve resolution.

In addition, in order to improve the fresh storage property, for example, Japanese Patent Application Laid-Open No. 50-62
Leuco dye compounds such as those described in No. 025 can be used. Furthermore, as described in Japanese Patent Application Laid-Open No. 50119623, in order to improve the residual color of the pigment, it is possible to make blue ink using a blue dye such as Victoria Blue to improve the whiteness. 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 mercapto compound as described in U.S. Pat. , methods of providing laminates containing stabilizers, and further stabilization with aldehyde compounds. 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,
These include naturally occurring substances such as cellulose derivatives, polysaccharides such as dextran, gum arabic, 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 US Pat. No. 3,142,586, US Pat. No. 3,193,386, US Pat.
No. 0844, No. 3287289, No. 341191
Examples include those described in each specification of No. 1.

Effective polymers include water-insoluble polymers containing monomers such as alkyl acrylate, alkyl methacrylate, acrylic acid, sulfoalkyl acrylate, or sulfoalkyl methacrylate, and Canadian Patent No. 774054.
Examples include those having cyclic sulfobetaine units as described in No.

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, polyisoptylene, butadiene styrene copolymers. , vinyl chloride monovinyl acetate copolymer, vinyl chloride vinyl acetate-maleic acid terpolymer, polyvinyl alcohol, polyvinyl acetate, benzyl cellulose,
Examples include cellulose acetate, cellulose propionate, cellulose acetate phthalate, and the like. Among these polymers, polyvinyl butyral, polypynylacetate, ethyl cellulose, polymethyl methacrylate, and cellulose acetate butyrate are particularly preferred. If necessary, two or more types may be used in combination. The amount of binder is component a)
About 10:1 to about 1:101 by weight to the organic silver salt of
Preferably the ratio is from about 4:1 to about 1:4. Japanese Patent Application Publication No. 47-4
It can also be made into a lithographic printing plate by using a special binder as described in the '659 publication and US Pat. No. 3,679,414. Also, U.S. Patent No. 3
A lithographic printing plate can also be obtained by forming a special layer structure as described in No. 811,886. Furthermore,
U.S. Patent No. 3,767,394 and Japanese Patent Publication No. 49-1
It can also be used as a thermal transferable sheet as described in Japanese Patent No. 03639.

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

These layers may also contain, for example, water-soluble salts such as rogides, nitrates, U.S. Pat.
206,312, as well as insoluble inorganic salts such as those described in U.S. Pat. No. 3,428,451. It may also have a vapor-deposited metal layer. If desired, the heat-developable photosensitive material may also contain an antihalation substance or an antihalation dye. As suitable dyes, those which are thermally decolorizable are preferred. For example, US Patent No. 3769019, US Patent No. 3745009, US Patent No. 3
Preference is given to dyes such as those described in Patent No. 615,432. Additionally, filter dyes and light-absorbing substances such as those described in U.S. Pat. No. 3,253,921, U.S. Pat. No. 2,527,583, and U.S. Pat. If desired, the heat-developable photosensitive material may further contain starch, titanium dioxide, zinc oxide, silica,
Matting agents such as polymeric beads, alumina, kaolin, clay, etc., including beads such as those described in U.S. Pat. Nos. 2,922,101 and 2,761,245, may be included. For example, West German Patent No. 9720
No. 67, No. 1150274, French Patent No. 15302
No. 44, U.S. Patent No. 2933390, U.S. Patent No. 34060
Fluorescent brighteners such as stilbenes, triazines, oxazoles, and coumarins as described in each specification of No. 70 may be included. These fluorescent brighteners are used as aqueous solutions or dispersions. The photothermographic material may 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. No. 2,588.
For example, fatty acids or esters thereof as described in British Patent No. 765 and British Patent No. 3121060, and silicone resins as described in British Patent No. 955061 can be mentioned.

Also surfactants, such as saponins and alkylaryl sulfonates, such as those described in U.S. Pat. No. 2,600,831, e.g., U.S. Pat.
They may contain amphoteric compounds such as those described in British Patent No. 16, and adducts of glycidol and alkylphenols such as those described in British Patent No. 1,022,878.

Hardenable layers among the heat-developable photosensitive layers used in the practice of the present invention can be hardened with 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,
Examples include sulfonyl halides and pinyl sulfonyl esters, active halogen compounds, epoxy compounds, aziridines, active olefins, isocyanates, carbodiimides, polymeric hardeners such as dialdehyde starches, and the like. Various additives are used to further increase the density of the resulting image. For example, compounds having groups such as -CO-, -SO- or -SO2- as described in U.S. Pat. No. 3,667,959, such as tetrahydrothiophene-1,1-dioxide, 4-hydroxybutanone Non-aqueous polar organic solvents such as acid lactones and methylsulfinylmethane are effective. Additionally, zinc, cadmium, and copper acetates, such as those described in U.S. Pat. No. 3,708,304, are also effective. Furthermore, crystalline water compounds such as those described in Japanese Patent Publication Nos. 44-26582 and 45-18416, acid salts of amines, metal oxides, or hydroxides can be made alkaline by heating. Compounds such as are also effective as substances that promote development. Alternatively, polyalkylene glycols and mercaptotetrazoles can be used in combination to improve sensitivity, contrast and image density as described in US Pat. No. 3,666,477.
An undercoat layer may be provided between the support and the heat-developable photosensitive layer in the heat-developable photosensitive material used in the practice of the present invention.

As the binder used in this undercoat layer, the various polymers already mentioned can be used. For example, polyvinyl butyral, polyacrylamide, cellulose acetate butyrate, cellulose acetate propionate, polymethyl methacrylate, polystyrene, polyvinylpyrrolidone, ethyl cellulose, polyvinyl chloride, chlorinated rubber, polyisoptylene, butadiene-styrene copolymer, vinyl chloride monoacetate Examples include copolymers, vinyl chloride monovinyl acetate-maleic acid copolymers, polyvinyl alcohol, polyvinyl acetate, cellulose acetate, cellulose propionate, cellulose acetate phthalate, gelatin, gelatin derivatives, polysaccharides, and the like. By further containing a fatty acid or a metal salt of a fatty acid in the undercoat polymer layer, photographic properties such as photochromic discoloration and thermal fog can be improved. Furthermore, by containing a pigment such as clay, it is possible to prevent the penetration of solvents. In addition, matting agents such as alumina, starch, silica, kaolin, titanium dioxide, and zinc oxide may be contained. Furthermore, it may be an electrolessly deposited layer of conductive metal as described in US Pat. No. 3,748,137. Also, in the case of paper, by providing a preferably hydrophobic polymer layer on the back side of the support, moisture resistance can be increased and curling can be prevented. Also, Japanese Patent Application Publication No. 1973-
As described in Japanese Patent No. 6917, in order to increase the transparency of the heat-developable photosensitive layer, increase the image density, and improve the shelf life, an overcoat polymer layer may be provided on the photosensitive layer, if desired. Can be done. The thickness of the overcoat polymer layer is suitably between about 1 micron and about 20 microns. Suitable polymers for the overcoat 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,
Examples include cellulose propionate, cellulose acetate phthalate, polycarbonate, cellulose acetate propionate, and polyvinylpyrrolidone. Also, Pelky National Patent No. 798367 and Japanese Patent Application Laid-Open No. 1983-46
As described in the specification of No. 316, by incorporating a carrier such as polysaccharides such as kaolin, silica, and starch into the top coat polymer layer, it is possible to write with stamp ink, ink, ballpoint pen, pencil, etc. Can be done. The top polymer layer can also contain filter dyes, ultraviolet absorbers, and acid stabilizers such as higher fatty acids. The layers containing each component used in the photothermographic material and other layers are coated on various supports selected from a wide variety of materials.

Generally, this support may 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 or sheet. Materials for the support include cellulose nitrate, cellulose ester (partially acetylated versions of these are also good), plastic films or sheets such as polyvinyl acetal, polyethylene, polyethylene terephthalate, and polycarbonate, glass, paper, and aluminum. Examples include films and sheets made of metals such as. Also, baryta paper, resin coated paper,
Water-resistant paper can also be used. As the paper support, clay-treated paper such as art paper or coated paper is most suitable, and paper sized with polysaccharide or the like may also be used. 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 certain components are mixed into the support (paper base material), they will exhibit the same effect as if they were mixed into 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. 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. The photothermographic material thus produced is cut into a size suitable for use and then imagewise exposed.

As already mentioned, preheating (8'C to 140C) 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, 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, reflection printing may be performed, or enlargement printing may be performed. The amount of exposure varies depending on the sensitivity of the sensitive 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 can be developed by simply being heated (about 80°C to about 180°C, preferably about 100°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 120℃
About 5 seconds to about 40 seconds at 130℃, about 2 seconds to about 20 seconds, 1
A temperature of about 1 second to about 10 seconds at 40°C is suitable. 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. It's okay. Further, heating may be performed by high frequency heating or laser beam. A deodorizing agent can also be provided in the processor to prevent odors generated during heating. Also, some kind of fragrance can be included so that the odor of the photosensitive material is not detected. The method for preparing the heat-developable photosensitive material 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. The preparation conditions are usually under atmospheric pressure, and the temperature is -15°C to +8°C.
It can be selected appropriately within the range of 0°C. Usually about 20℃
~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. Normal temperature (15
(°C to 25°C). A silver halide forming agent is added to the silver salt polymer dispersion thus prepared to convert a portion of the organic silver salt into silver halide. The reaction temperature is room temperature ~
Approximately 80°C is suitable, and the reaction time can be arbitrarily selected within the range of about 1 minute to about 48 hours. As already mentioned, the silver halide may be prepared in advance and added, or the silver halide may be prepared simultaneously with the organic silver salt. This is followed by sensitization using the method of the present invention. Next, sensitizing dye, reducing agent,
Various additives such as color toning agents are sequentially added, preferably in the form of a solution. Usually, the ingredients are added one after another at appropriate time intervals (usually 5 to 20 minutes) while stirring at a temperature of room temperature to 50°C. When all the additives have been added in this way, the coating liquid has been prepared. This coating solution &ζ is directly coated onto a suitable support without drying. The coating silver amount is generally about 0.1 V/I to about 107
/wl is determined depending on the purpose. Generally 0.
A range of 2y to 5y/TI is preferred. If the amount of coated silver is too small, sufficient image density cannot be obtained. If the amount of coated silver is too large, the cost will increase. Coating solutions are prepared for the top polymer layer, undercoat layer, pack layer, and other layers as well as for the heat-developable photosensitive layer formed by such an operation. It can be formed by sequentially applying various coating methods such as a single coating method. Further, if necessary, see US Pat. No. 2,761,791 and British Patent No. 8,370.
Two or more layers can also be applied simultaneously by methods such as those described in '95. The above-mentioned heat-developable photosensitive materials generally have a property that their photographic properties tend to deteriorate due to moisture.

Therefore, when the photosensitive material prepared by the method of the present invention is packaged and sent out as a product, it is desirable to have a desiccant present as described in JP-A No. 50-2523. A heat-developable photosensitive material containing such a composition has a feature of extremely high sensitivity and is therefore extremely useful.

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

Example 1 100 mj of an aqueous solution in which 1.9f7 of sodium hydroxide was dissolved and 200 m1 of toluene in which lauric acid 12y was dissolved were mixed and emulsified using a homomixer.

50 ml of hydrobromic acid (0.4% aqueous solution) was added to this emulsion to emulsify it again. An aqueous solution 50W11 in which 8.5V of silver nitrate was dissolved 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 180f of a 15% by weight solution of polyvinyl butyral in isopropanol 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 solution 80V (approximately 1/60 mol of silver salt)
Add 16 ml of acetamide acetone solution, then add 20 ml of a 4 x 10-4 wt% ethanol solution of the following compound (1).
After adding m1 and heating to 50°C for 30 minutes, the mixture was returned to room temperature.

This is called liquid A. Solutions B to E were prepared as chemical formula comparison samples of compound (1) in the same manner as in the preparation of solution A, except for the points shown in Table 1.

Next, the following components were sequentially added to each solution at 5-minute intervals while stirring the A-E solutions at 20° C. to prepare coating solutions. The five types of coating liquids thus prepared were coated onto art paper at a silver content of 0.3 V per square and dried to produce four types of photothermographic materials.

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 120° C. for 20 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 effective.

Examples 2 to 6 A photothermographic material D7-H was prepared in the same manner as in Example 1 except that the following compound was used instead of compound (1) in Example 1.

Table 3 lists the sample preparation conditions.

Cenocytometry was performed on each sample in the same manner as in Example 1, and the results shown in Table 4 were obtained.

* Relative sensitivity when the sensitivity of sample B is set to 100 Examples 7 to 9 Samples K-M were prepared using butyramide, succinimide, or dibenzamide in place of acetamide in Example 1.

The results of sensitometry under the same conditions as Example 1 are shown in the sixth example.
Shown in the table.

}( Cetylethyldimethylammonium furomide 0
．． An aqueous solution of 8y dissolved in 100ml of water and 10ml of toluene
0ml was mixed.

A solution prepared by dissolving 0.4257 of silver nitrate in 10 ml of water was added to produce silver bromide. This silver bromide exists in an emulsified state. Next, add 12y of lauric acid to 100ml of toluene.
and sodium hydroxide 1.97 in 100 m of water.
An emulsified mixture of 1 and 1 was added. Next, a solution of 8.57 g of silver nitrate dissolved in 50 ml of water was added to produce silver laurate. This means that a mixture of silver bromide and silver laurate has been obtained. A mixture was collected by centrifugation and dispersed in an ethanol solution 2007 containing a binder 307 such as polyvinyl butyral using a mixer or the like to prepare a polymer dispersion of silver salt.

To this polymer dispersion was added 25 ml of a 2% by weight solution of benzamide in ethanol, and then compound (1) of Example 1 was added.
After adding 30 ml of an 8×10 −4 wt % acetone solution, the mixture was heated at 45° C. for 40 minutes.

This is called N solution. To prepare a comparison sample, O
A liquid was prepared. Compound (1) was also used as a comparison sample.
Solution P was prepared in exactly the same manner as in the preparation of Solution L, except that benzamide was not added. These two types of silver salt polymer dispersion liquids L, M and N were kept at 30° C., and the following components were added in order at 5 minute intervals to prepare a coating solution.

The two types of coating solutions prepared in this way were each applied on art paper at a silver content of 0.5 to 1 square meter. I applied it and let it dry.

Furthermore, on top of that, 1.5 ml of fine silica powder with an average particle size of about 2μ is added.
An overcoat layer was provided by applying a 10% by weight acetone solution of cellulose diacetate to a thickness of 1.5 μm. These two heat-developable photosensitive materials are referred to as sample L, sample M, and sample N, respectively. Sensitometry was carried out on the three samples under the same conditions as in Example 1, except that development was carried out at a temperature of 140° C. for 15 seconds.

The relative sensitivity and thermal fog measured for each sample are shown in Table 7. From the results shown in Table 7, it was confirmed that Sample L according to the present invention had significantly improved relative sensitivity while suppressing thermal fog to a considerably low level.

Example 11 3.4 behenic acid in 100wL1 benzene
t was dissolved at 60°C, and the temperature was adjusted to 60°C.

Stir with a stirrer*{(While stirring, add 100 ml of water to emulsify it. Next, add ammonia water to about 80 d of an aqueous solution containing 1.7 f of silver nitrate to make a silver ammonium complex salt, and add water to bring the total volume to 100 ml. aqueous solution (temperature is 1
0°C) was added. In this way, microcrystals of silver behenate were obtained.

When this liquid mixture was allowed to stand at room temperature (25°C) for 20 minutes, it was separated into an aqueous phase and a benzene phase. Therefore, first, the aqueous phase was removed, and 400 d of water was added thereto for washing by decantation. Next, 400 d of methanol was added and silver behenate was collected by centrifugation. A spindle-shaped silver behenate 47 having a long side of approximately 1 micron and a short side of approximately 0.05 micron was obtained. This silver behenate 2.37 was dissolved in an ethanol solution containing 2.5f7 of polyvinyl butyral.
It was dispersed in 0 ml.

of ammonium bromide to this polymer dispersion of silver salt.
Weight% methanol solution (silver oxide forming component) 1ml
was added and heated at 50°C for 10 minutes. This is called liquid Q. Separately, 3 ml of a 2 wt% ethanol solution of prolactam was added to this polymer dispersion of silver salt, and then Example 1
6d of 8X10-4% by weight acetone solution of compound (1)
was added and heated at 55°C for 30 minutes.

This is called R liquid. Furthermore, in order to serve as a comparative sample, Solution S was prepared in the same manner as in the preparation of Solution Q, except that prolactam was not added. A coating solution was prepared by sequentially adding the following components to a polymer dispersion of three types of silver salts at 25° C. at 5 minute intervals.

Claims (1)

[Scope of Claims] 1. Before coating a composition for a heat-developable photosensitive material containing at least (a) an organic silver salt and (b) a photosensitive silver halide, (c) a compound having -CONH- units and ( d) A method for producing a composition for a photothermographic material, which comprises heating in the presence of a sulfur-containing organic compound selected from the following compounds (1) or (2). (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).