JPH0361179B2 - - Google Patents

Description

[Detailed description of the invention]

(Technical Field of the Invention) The present invention relates to a heat-developable photosensitive material containing a thermally decomposable organic silver salt. (Background of the Invention) Silver halides used in heat-developable photosensitive materials include silver chloroiodide, which contains silver iodide crystals in its grains and therefore exhibits an X-ray pattern of silver iodide crystals.
Although some silver halides such as silver iodobromide and silver chloriobromide can be used without the use of organic silver salts, all silver halides known in the industry can be used by using organic silver salts in combination. Advantageously, a higher maximum concentration can be obtained. Typical examples of such organic silver salts include silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Further, there are silver salts of aliphatic carboxylic acids having a thioether group, which are described in US Pat. No. 3,330,663. However, these carboxylic acid silver salts have the disadvantage that after reaction with a reducing agent, the acid is released, the pH in the film is lowered, and subsequent development is inhibited. Organic silver salts other than carboxylic acids include silver salts of compounds having mercapto or thione groups and derivatives thereof. In addition, there are silver salts of compounds having imino groups, such as silver salts of benzotriazole and derivatives thereof described in Japanese Patent Publications No. 44-30270 and No. 45-18416. However, these silver salts have the disadvantage that after reaction with reducing agents they release compounds which inhibit or even fog the development. It may also inhibit the action of spectral sensitizing dyes. OBJECTS OF THE INVENTION The present invention ameliorates these drawbacks. An object of the present invention is to provide a photosensitive material capable of producing high-density images in a short period of time. A second object of the present invention is to provide a photosensitive material capable of producing images with high density and low fog. A third object of the present invention is to provide an organic silver salt for heat-developable photosensitive materials that does not exhibit any side effects after heat development. (Disclosure of the Invention) The above object is achieved by a heat-developable photosensitive material containing a thermally decomposable organic silver salt. Among the above thermally decomposable organic silver salts, the temperature is preferably 80°C to 250°C, and more preferably 100°C to
It is a carboxylic acid silver salt that decarboxylates at 200℃. Among the carboxylic acid silver salts that are decarboxylated at the above-mentioned temperature, preferred ones are those represented by the following general formula. [General formula (2)] R ⁰ (-C≡C-CO ₂ ) m・mAg In the above formula, R ⁰ is a hydrogen atom, an alkyl group,
Substituted alkyl group, cycloalkyl group, alkenyl group, alkynyl group, aryl group, substituted aryl group, heterocyclic residue, substituted heterocyclic residue, aralkyl group, substituted aralkyl group, acyl group, alkoxycarbonyl group, carbamoyl group, substituted A monovalent residue selected from a carbamoyl group, -CO ₂ M (M is an alkali metal), -CO ₂ B, or an alkylene group, an arylene group, a heterocyclic divalent residue (these may further have a substituent). represents a divalent residue selected from B is an organic base conjugated acid or a quaternary ammonium group. Typical organic bases include guanidines, cyclic guanidines, amidines, and cyclic amidines. Examples of R ⁰ include a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a substituted alkyl group having 1 to 5 carbon atoms, a cycloalkyl group having 5 to 8 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, and an alkenyl group having 2 to 5 carbon atoms. 2 to 5 alkynyl groups, phenyl groups, substituted phenyl groups, naphthyl groups, substituted naphthyl groups, anthryl groups, pyridyl groups, substituted pyridyl groups, thienyl groups, substituted thienyl groups, thiazolyl groups, benzoxazolyl groups, benzothiazolyl groups, Aralkyl group having 7 to 10 carbon atoms, 2 to 12 carbon atoms
acyl group, alkoxycarbonyl group having 2 to 9 carbon atoms, carbamoyl group, substituted carbamoyl group having 2 to 9 carbon atoms, -CO ₂ Na, -CO ₂ K, -CO ₂ Cs, -
Examples include CO ₂・B (B is the above-mentioned base component), 1,3-phenylene group, 1,4-phenylene group, 1,5-naphthylene group, 2,5-thienylene group, 9,10-antrylene group, etc. It will be done. It is desirable that R ⁰ has appropriate electron-withdrawing properties, such as an alkenyl group, an alkynyl group, a phenyl group, a substituted phenyl group, a naphthyl group, a substituted naphthyl group, an anthryl group, a pyridyl group, a substituted pyridyl group, a thienyl group, and a substituted thienyl group. , benzoxazolyl group, benzothiazolyl group, acyl group, alkoxycarbonyl group, carbamoyl group, substituted carbamoyl group, -CO ₂ M, -
CO ₂ ·B, phenylene group, naphthylene group, thienylene group, anthrylene group, etc. are preferably used. Next, specific examples of preferable thermally decomposable organic silver salts used in the present invention will be shown, but the present invention is not limited thereto. (1) HC≡C-CO ₂・Ag (2) CH ₃ −C≡C-CO ₂・Ag The thermally decomposable organic silver salt of the present invention can be prepared by synthesizing a decarboxylating carboxylic acid by the method shown below and mixing this acid with a silver ion donor (for example, silver nitrate). Regarding the synthesis of decarboxylated carboxylic acids, the synthesis method differs depending on the type, but in any case, it can be synthesized by a known general method. To give a typical example, when R is a substituted alkyl group having an electron-withdrawing group at the α-position, reaction of α-haloacetic acid with a nucleophilic reagent such as a sulfinate or cyanide,
Reaction of an active methyl or active methylene compound with a carbonate ester in the presence of a base, etc.; When R is a substituted aryl group having an electron donating group, carboxylation by Kolbe-Schmidt reaction; When R is an alkynyl group, These include addition of bromine to acrylic acid derivatives and subsequent dehydrobromination. For information on these reactions, please contact the New Experimental Chemistry Course 14 () 921-1062.
(1977, Maruzen); Organic Functional Group
Preparations, 196−268 (1968, Academic
Press) has a detailed description. Furthermore, for relatively simple compounds such as trihaloacetic acid, phenylacetic acid derivatives, and α-ketocarboxylic acids, commercially available products can be used as they are. An example of synthesis of a thermally decomposable organic silver salt will be described below. Synthesis of Γ organic silver salt (3) 29.6 g of cinnamic acid was heated and dissolved in 80 ml of acetic acid, and then 32 g of bromine was added dropwise. After stirring at 50°C for 15 minutes, the mixture was allowed to cool, 100 ml of water was gradually added, and the white crystals formed were collected, washed with water, and dried. Yield 56g.
56 g of potassium hydroxide was dissolved in 200 ml of methanol, and the above crystals were then added little by little into the solution. Methanol was distilled off while heating and stirring on a hot water bath. The residue was dissolved in 200 ml of water and neutralized with dilute sulfuric acid under ice cooling. The liberated pale yellow oil quickly solidified. The solidified crystals were collected and recrystallized from water to obtain 22 g of phenylpropiolic acid. Melting point: 135-137°C The above acid was converted into a silver salt according to a conventional method. Synthesis of Γ organic silver salt (45) 33 g of potassium hydroxide was added to a mixture of 26.2 g of thioglycolic acid and 150 ml of toluene, and the mixture was heated and stirred. The produced water is distilled off together with toluene, and when no water is distilled out, dimethylacetamide is removed.
100 ml was added and then 59.4 g of p-bromodiphenyl sulfone was added portionwise. 150−160℃
After stirring for 3 hours, the mixture was allowed to cool and the reaction mixture was poured into cold dilute hydrochloric acid. The liberated oil was extracted with ethyl acetate, the extract was washed with water, and after drying, the ethyl acetate was concentrated under reduced pressure, and the precipitated crystals were collected and washed with toluene. Yield 44g 40g of the above crystals, 2 sodium tungstate
A mixture of 0.2 g of aqueous salt and 120 ml of acetic acid was heated to 50°C, and 30 ml of 35% hydrogen peroxide solution was added dropwise at 50 to 60°C. After dropping, stir at 75℃ for 30 minutes, then let it cool.
The reaction solution was poured into cold water. The precipitated white crystals were collected, washed with water, and dried to obtain 41 g of (p-phenylsulfonylphenyl)-sulfonylacetic acid. Melting point: 194-196°C (decomposition) The above acid was converted into a silver salt according to a conventional method. Synthesis of Γ organic silver salt (53) 21.6 g of finely divided diphenylmethylphosphine oxide was added to 400 ml of dry ether, and with vigorous stirring, 0.1 mol of butyllithium hexane solution was added little by little. The reaction mixture was heated under reflux for 3 hours, cooled to 20° C., and added little by little into a mixture of 100 g of finely crushed dry ice and 300 ml of ether. After stirring for 10 minutes, the ether was distilled off, diluted hydrochloric acid was added to the residue, and the mixture was extracted with ethyl acetate.
The ethyl acetate extract was extracted repeatedly with a 5% aqueous sodium bicarbonate solution, the extract was made acidic with dilute hydrochloric acid, and the precipitated white crystals were collected, washed with water, and dried to obtain 16.8 g of carboxymethyl diphenylphosphine oxide. Melting point: 143-146°C Next, this free acid was converted into a silver salt according to a conventional method to obtain an organic silver salt (53). The thermally decomposable organic silver salt may be prepared in the same system, that is, in combination with other components of the photothermographic material, or outside the same system, that is, prepared separately from other components of the photothermographic material. You may. However, in consideration of ease of control during preparation and ease of storage, it would be preferable to prepare it separately from the other components of the photothermographic material. A salt of a decarboxylated carboxylic acid with silver can also be obtained by simply mixing a source of silver ions, such as silver nitrate, and a decarboxylated carboxylic acid in a hydrophilic solvent such as water and/or methanol. In this case, they may be mixed in the presence of a hydrophilic binder such as gelatin. Purification of the resulting product or dispersion can be carried out according to techniques known in the art. Two or more kinds of organic silver salts of the present invention can be used. It can also be used in combination with known organic silver salts. The organic silver salt of the present invention can be used in the same layer as the photosensitive silver halide or in an adjacent layer. The organic silver salt of the present invention can be used in a wide concentration range. The coating amount is 10mg to 10g/ in terms of silver.
^m2 is appropriate. Also, for photosensitive silver halide
It ranges from 0.01 to 200 moles. Further, the shape and particle size of the organic silver salt of the present invention can be arbitrarily selected, but the average particle size is preferably 10 μm or less. Silver halides used in the present invention include silver chloride, silver chlorobromide, silver chloroiodide, silver bromide, silver iodobromide, silver chloroiodobromide, and silver iodide. Such silver halide can also be obtained, for example, by adding a silver nitrate solution to a potassium bromide solution to form bromide grains, and then adding potassium iodide. Two or more types of silver halide having different sizes and/or silver halide compositions may be used in combination. The average grain size of the silver halide grains used in the present invention is preferably from 0.001 .mu.m to 10 .mu.m, more preferably from 0.001 .mu.m to 5 .mu.m. The silver halide used in the present invention may be used as it is, but it may also be compounded with compounds such as sulfur, selenium, tellurium, etc., chemical sensitizers such as compounds such as gold, platinum, palladium, rhodium and iridium, tin halide, etc. Chemical sensitization may be achieved by the use of reducing agents such as or combinations thereof. For details,
“The theory of the Photographic Process”
4th edition, by TH James, chapter 5, pages 149-169. In the present invention, the coating amount of photosensitive silver halide is suitably 1 mg to 10 g/m ² in terms of silver. The reducing agents used in the present invention include the following. Hydroquinone compounds (e.g. hydroquinone, 2,5-dichlorohydroquinone, 2-chlorohydroquinone), aminophenol compounds (e.g. 4-aminophenol, N-methylaminophenol, 3-methyl-4-aminophenol, 3,5-dibromoamino phenol), catechol compounds (e.g. catechol, 4-cyclohexylcatechol, 3-methoxycatechol, 4
-(N-octadecylamino)catechol), phenylenediamine compounds (e.g. N,N-diethyl-p-phenylenediamine, 3-methyl-N,N
-dimethyl-p-phenylenediamine, 3-methoxy-N-ethyl-N-ethoxy-p-phenylenediamine, N,N,N',N'-tetramethyl-
p-phenylenediamine). Examples of more preferable reducing agents include the following. 3-pyrazolidone compounds (e.g. 1-phenyl-3-hyrazolidone, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolidone, 1-m-tolyl) -3-pyrazolidone, 1-p
-Tolyl-3-pyrazolidone, 1-phenyl-4
-Methyl-3-pyrazolidone, 1-phenyl-5
-Methyl-3-pyrazolidone, 1-phenyl-
4,4-bis-(hydroxymethyl)-3-pyrazolidone, 1,4-di-methyl-3-pyrazolidone, 4-methyl-3-pyrazolidone, 4,4-dimethyl-3-pyrazolidone, 1-(3- Chlorophenyl)-4-methyl-3-pyrazolidone, 1-
(4-chlorophenyl)-4-methyl-3-pyrazolidone, 1-(4-tolyl)-4-methyl-3-pyrazolidone, 1-(2-tolyl)-4-methyl-3
-pyrazolidone, 1-(4-tolyl)-3-pyrazolidone, 1-(3-tolyl)-3-pyrazolidone,
1-(3-tolyl)-4,4-dimethyl-3-pyrazolidone, 1-(2-trifluoroethyl)-4,
4-dimethyl-3-pyrazolidone, 5-methyl-
3-pyrazolidone). Combinations of various developers can also be used, such as those disclosed in US Pat. No. 3,039,869. In the present invention, the amount of the reducing agent added is 0.01 to 20 mol, particularly preferably 0.1 to 10 mol, per 1 mol of silver. In the present invention, even when using a reducing dye-donating substance, a so-called auxiliary developer can be used as necessary. The auxiliary developer in this case is
Oxidized by silver halide, the oxidized product is
It has the ability to oxidize the reducing substrate in the dye-donating substance. Useful auxiliary developers include hydroquinone, alkyl-substituted hydroquinones such as t-butylhydroquinone and 2,5-dimethylhydroquinone, catechols, pyrogallols, halogen-substituted hydroquinones such as chlorohydroquinone and dichlorohydroquinone, and alkyl-substituted hydroquinones such as methoxyhydroquinone. There are substituted hydroquinones and polyhydroxybenzene derivatives such as methylhydroxynaphthalene. Furthermore, methyl gallate, ascorbic acid, ascorbic acid derivatives, N,N'-
Hydroxylamines such as di-(2-ethoxyethyl)hydroxylamine, 1-phenyl-3
Pyrazolidones such as -pyrazolidone, 4-methyl-4-hydroxymethyl-1-phenyl-3-pyrazolidone, reductones, and hydroxytetronic acids are useful. Auxiliary developers can be used in a range of concentrations. The useful concentration range is 0.0005 times molar to 20 times molar relative to silver, and particularly useful concentration ranges are:
It is 0.001 times mole to 4 times mole. The binder used in the present invention can be contained alone or in combination. A hydrophilic binder can be used for this binder. Typical hydrophilic binders are transparent or translucent hydrophilic binders, such as proteins such as gelatin, gelatin derivatives, and cellulose derivatives, natural substances such as starch, polysaccharides such as gum arabic, polyvinylpyrrolidone, Includes synthetic polymeric materials such as water-soluble polyvinyl compounds such as acrylamide polymers. Other synthetic polymeric materials include dispersed vinyl compounds, which increase the dimensional stability of photographic materials, especially in the form of latexes. The silver halide used in the present invention may be spectrally sensitized with methine dyes and others. The pigments used include cyanine pigments, merocyanine pigments, composite cyanine pigments, composite merocyanine pigments,
Holopolar cyanine dye, hemicyanine dye,
Included are styryl dyes and hemioxonol dyes. Particularly useful dyes are those belonging to the cyanine dyes, merocyanine dyes, and complex merocyanine dyes. Any of the nuclei commonly used for cyanine dyes can be used as the basic heterocyclic nucleus for these dyes. That is, pyrroline nucleus, oxazoline nucleus, thiazoline nucleus, pyrrole nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus, imidazole nucleus, tetrazole nucleus, pyridine nucleus, etc.; a nucleus in which an alicyclic hydrocarbon ring is fused to these nuclei; and these A nucleus in which an aromatic hydrocarbon ring is fused to the nucleus of Imidazole nuclei, quinoline nuclei, etc. can be applied. These nuclei may be substituted on carbon atoms. Merocyanine dyes or composite merocyanine dyes include a pyrazolin-5-one nucleus, a thiohydantoin nucleus, a 2-thioxazolidine-2,4-dione nucleus, a thiazolidine-2,4-dione nucleus, and a rhodanine nucleus having a ketomethylene structure. Nuclei, 5- to 6-membered heterocyclic nuclei such as thiobarbituric acid nuclei can be applied. Useful sensitizing dyes include, for example, the German patent
929080, U.S. Patent No. 223168, U.S. Patent No. 2493748, U.S. Pat.
No. 2503776, No. 2519001, No. 2912329, No. 2519001, No. 2912329, No.
No. 3656959, No. 3672897, No. 3694217, No.
No. 4025349, No. 4046572, British Patent No. 1242588,
Examples include those described in Japanese Patent Publication Nos. 44-14030 and 52-24844. These sensitizing dyes may be used alone or in combination, and combinations of sensitizing dyes are often used particularly for the purpose of supersensitization.
Typical examples are U.S. Patent No. 2688545, U.S. Patent No. 2977229,
3397060, 3522052, 3527641, 3527641, 3522052, 3527641,
No. 3617293, No. 3628964, No. 3666480, No.
No. 3672898, No. 3679428, No. 3703377, No. 3672898, No. 3679428, No. 3703377, No.
No. 3769301, No. 3814609, No. 3837862, No. 3837862, No. 3814609, No. 3837862, No.
40265707, British Patent No. 1344281, British Patent No. 1507803,
Special Publication No. 43-4936, No. 53-12375, Japanese Patent Publication No. 52-
No. 110618 and No. 52-109925. Along with the sensitizing dye, the emulsion may contain a dye that itself does not have a spectral sensitizing effect or a substance that does not substantially absorb visible light and exhibits supersensitization. For example, aminostyryl compounds substituted with nitrogen-containing heterocyclic groups (e.g.,
2933390 and 3635721), aromatic organic acid formaldehyde condensates (for example, those described in US Pat. No. 3743510), cadmium salts, azaindene compounds, and the like. US patent
No. 3615613, No. 3615641, No. 3617295, No. 3615613, No. 3615641, No. 3617295, No.
The combination described in No. 3635721 is particularly useful. Further, in the present invention, it is possible to use a compound that activates the development and stabilizes the image at the same time. Among them, isothiuroniums represented by 2-hydroxyethylisothiuronium trichloroacetate described in U.S. Patent No. 3301678, 1,8-(3,6-dioxaoctane)bis(isothiuronium・Bisisothiuroniums such as trifluoroacetate),
Thiol compounds disclosed in West German Patent No. 2162714, 2-amino-2- described in U.S. Patent No. 4012260
Thiazolium compounds such as thiazolium trichloroacetate, 2-amino-5-bromoethyl-2-thiazolium trichloroacetate,
Bis(2-amino-2
Compounds having α-sulfonylacetate as an acidic moiety, such as -thiazolium)methylenebis(sulfonylacetate), 2-amino-2-thiazoliumphenylsulfonylacetate, etc.
2- as the acidic moiety described in U.S. Pat.
Compounds having carboxycarboxamide are preferably used. Furthermore, azole thioether and blocked azolinthione compounds described in Belgian Patent No. 768071 and 4-aryl-
1-Carbamyl-2-tetrazoline-5-thione compound, etc. U.S. Patent Nos. 3839041 and 3844788
Compounds described in No. 3,877,940 are also preferably used. In the present invention, an image toning agent may be contained if necessary. Effective toning agents are 1, 2,
These compounds include 4-triazole, 1H-tetrazole, thiouracil, and 1,3,4-thiazoazole. Examples of preferred toning include 5-amino-1,3,4-thiadiazole-2-thiol, 3-mercapto-1,2,4-triazole, bis(dimethylcarbamyl) disulfide,
Examples include 6-methylthiouracil and 1-phenyl-2-tetraazoline-5-thione. Particularly effective toning agents are compounds capable of forming black images. The concentration of the toning agent contained varies depending on the type of photothermographic material, processing conditions, desired image, and other factors, but is generally about 0.001 to 1 mole of silver in the photosensitive material. It is 0.1 mole. Various dye release aids can be used in the present invention. The dye release aid is a compound exhibiting basicity and capable of activating development, or a compound having so-called nucleophilicity, and a base or a base precursor is used. The dye-releasing aid can be used in either a light-sensitive material or a dye-fixing material. It is especially advantageous to use a base precursor when it is included in a light-sensitive material. The base prekerner here is
A base component is released by heating, and the base component released may be an inorganic base or an organic base. Examples of preferred bases include inorganic bases such as alkali metal or alkaline earth metal hydroxides, secondary or tertiary phosphates, borates, carbonates, quinolates, metaborates; immonium; Hydroxides; hydroxides of quaternary alkylammonium; hydroxides of other metals, etc.; organic bases include aliphatic amines (trialkylamines, hydroxylamines, aliphatic polyamines, aromatic amines (N-alkyl-substituted aromatic amines, N-hydroxylalkyl-substituted aromatic amines and bis[p-(dialkylamino)
phenyl]methanes), heterocyclic amines, amidines, cyclic amidines, guanidines, and cyclic guanidines, and US Patent No. 2410644
No. 1 describes betaine tetramethylammonium iodide and diaminobutane dihydrochloride, and U.S. Pat. No. 3,506,444 describes organic compounds containing amino acids such as urea and 6-aminocaproic acid, which are useful. In the present invention, those having a pKa value of 8 or more are particularly useful. Examples of base precursors include salts of organic acids and bases that decompose by decarboxylation upon heating, compounds that decompose through Lothsen rearrangement, Betzkmann rearrangement, etc. and release amines, and those that cause some kind of reaction upon heating to release bases. used. Preferred base precursors include the aforementioned organic base precursors. Examples include salts with thermally decomposable organic acids such as trichloroacetic acid, trifluoroacetic acid, propiolic acid, cyanoacetic acid, sulfonylacetic acid, and acetoacetic acid, and salts with 2-carboxycarboxamide described in US Pat. No. 4,088,496. Preferred specific examples of base precursors are shown below. Examples of compounds whose acid moieties are thought to decarboxylate and release bases include the following: Examples of trichloroacetic acid derivatives include guanidine trichloroacetic acid, piperidine trichloroacetic acid, morpholine trichloroacetic acid, p-toluidine trichloroacetic acid, 2-picoline trichloroacetic acid, and the like. Other UK Patent No. 998945, US Patent No.
Base precursors described in No. 3220846, JP-A-50-22625, etc. can be used. Examples of compounds other than trichloroacetic acid include 2-carboxycarboxamide derivatives described in U.S. Pat. No. 4,088,496 and α described in U.S. Pat. No. 4,060,420.
-Sulfonylacetate derivative, patent application 1982-
Examples include salts of propiolic acid derivatives and bases described in No. 55700. In addition to organic bases, salts using alkali metals or alkaline earth metals as the base component are also effective and are described in Japanese Patent Application No. 1986-69597. Precursors other than those mentioned above include hydroxamic carbamates described in Japanese Patent Application No. 43860/1986 that utilize lotusene rearrangement, and Japanese Patent Application No. 58/1989 that generates nitriles.
The aldoxime culverts described in No. 31314 are effective. Also, Research Disclosure Magazine, 1977, 5
Amine imides described in Monthly Issue No. 15776
Aldonamides described in Japanese Patent No. 22625 are preferably used because they decompose at high temperatures to produce bases. These bases or base precursors can be used in a wide variety of ways. A useful range is 50% by weight or less, more preferably 0.01% to 40% by weight of the photosensitive material after coating and drying. Of course, it is possible to use it not only for promoting the dye release of the base or base precursor described above, but also for other purposes, such as adjusting the pH value. In the present invention, thermal solvents may be included, where "thermal solvents" are solids at ambient temperature, but do not form with other ingredients at or below the heat treatment temperature used. It is a non-hydrolyzable organic material that exhibits mixed melting points. Useful examples of the thermal solvent include compounds that can serve as solvents for developing agents, and compounds that are known to promote the physical development of silver salts using substances with a high dielectric constant. Useful thermal solvents include polyglycols described in U.S. Pat. No. 3,347,675, such as polyethylene glycol with an average molecular weight of 150 to 2,000, derivatives of polyethylene oxide such as oleic acid ester, beeswax, monostearin, _-SO2- , -CO- Compounds with high dielectric constant having groups such as acetamide, succinimide, ethyl carbamate, urea, methyl sulfonamide, ethylene carbonate, polar substances described in U.S. Pat. No. 3,667,959, lactone of 4-hydroxybutanoic acid, methyl sulfur Nilmethane, Tetrahydroniophene-1,1-dioxide, Research Disclosure Journal 1976 12
1,10-deranediol, methyl anisate, biphenyl suberate, etc. described on pages 25 to 28 of the issue are preferably used. “Research Disclosure” for various additives
Additives such as plasticizers, sharpness improving dyes, AH
These include dyes, sensitizing dyes, matting agents, fluorescent whitening agents, and anti-fading agents. In the present invention, as well as the heat-developable photosensitive layer, coating solutions for the protective layer, intermediate layer, undercoat layer, back layer, and other layers are prepared for each layer, and coated using the dipping method, air knife method, curtain coating method, or U.S. Patent No.
A light-sensitive material can be prepared by sequentially coating a support onto a support using various coating methods such as the hopper coating method described in No. 3,681,294 and drying the coating. Furthermore, if desired, two or more layers can be applied simultaneously by the methods described in US Pat. No. 2,761,791 and British Patent No. 837,095. The photographic light-sensitive material and dye-fixing material of the present invention include:
The photographic emulsion layer and other binder layers may contain an inorganic or organic hardener. For example, chromium salts (chromium alum, chromium acetate, etc.), aldehydes (formaldehyde, glyoxal, glitaraldehyde, etc.), N-methylol compounds (dimethylol urea, methyloldimenylhydantoin, etc.), dioxane derivatives (2,3-dihydantoin, etc.), Roxydioxane, etc.), activated vinyl compounds (1,
3,5-Triacryloyl-hexahydro-s-
triazine, 1,3-vinylsulfonyl-2-propanol, etc.), active halogen compounds (2,4
-dichloro-6-hydroxy-s-triazine, etc.), mucohalogen acids (mucochloric acid, mucophenoxychloroic acid, etc.), etc. can be used alone or in combination. The above-mentioned components constituting the heat-developable photosensitive material of the present invention can be placed at any appropriate position. For example, one or more of the components can be disposed in one or more layers in the light-sensitive material, if desired. In some cases, it may be desirable to include certain amounts (proportions) of reducing agents, image stabilizers and/or other additives, such as those described above, in the protective layer. In this case, the movement of additives between layers of the photothermographic material can be reduced,
It can also be advantageous. The heat-developable photosensitive material according to the present invention is effective for forming negative-type images or positive-type images. Here, forming a negative or positive image will depend primarily on the selection of a particular photosensitive silver halide. For example, US Pat.
No. 2592250, No. 3206313, No. 3367778, No. 3367778, No. 3206313, No. 3367778, No.
The internal image silver halide emulsion described in No. 3447927,
Also, mixtures of surface image silver halide emulsions and internal image silver halide emulsions such as those described in US Pat. No. 2,996,382 may be used. The support used in the light-sensitive material and dye-fixing material used in some cases in the present invention is one that can withstand processing temperatures. Common supports include glass, paper, metal and their analogs, as well as cellulose acetate film, cellulose ester film,
Included are polyvinyl acetal film, polystyrene film, polycarbonate film, polyethylene terephthalate film, and films or resin materials related thereto. Paper supports laminated with polymers such as polyethylene can also be used. US Patent 3634089
The polyester described in No. 3,725,070 is preferably used. Various exposure means can be used in the present invention. The latent image is obtained by imagewise exposure to radiation, including visible light. Light sources commonly used for color printing include tungsten lamps, mercury lamps, halogen lamps such as iodine lamps, xenon lamps, laser beams, and
CRT light sources, fluorescent tubes, light emitting diodes, etc. can be used as light sources. In the present invention, development is carried out by applying heat to the photosensitive material, but the heating means may be a simple hot plate, iron, hot roller, heating element using carbon, titanium white, or the like, or similar. Various imaging materials can be used in various ways in the present invention. For information on heat-developable photosensitive materials and their processes, please refer to the book Basics of Photographic Engineering (published by Corona Publishing, 1979).
Pages 553-555, 40 pages of video information published in April 1978,
Nebletts Handbook OF Photography and
Reprography 7th Ed. (Van Nostrsnd Reinhold
Company), pages 32-33, US Pat. No. 3,152,904,
No. 3301678, No. 3392020, No. 3457075, British Patent No. 1131108, No. 1167777, and Research Disclosure Magazine, June 1978 issue, pages 9-15 (RD-17029). For information on how to obtain a color image,
Many methods have been proposed. Regarding the method of forming a color image by combining an oxidized developer and a coupler, U.S. Pat.
- Aminophenol-based reducing agent has been awarded a Belgian patent
Issue 802519 and Research Disclosure Magazine
September 31, 1975, page 32, sulfonamide phenolic reducing agents are also disclosed in U.S. Patent No. 4,021,240.
In this issue, sulfonamide phenolic reducing agents and 4
Combinations with equivalent couplers have been proposed. The coupler used in the above image forming method is
Those described in the cited patents above are used. Furthermore, color couplers used in conventionally widely known liquid development processes can also be used. These couplers are compounds that can develop color by oxidative coupling with aromatic primary amine developers (e.g., phenylene diamine derivatives, aminophenol derivatives, etc.), and typical ones are collectively called as follows. It is something that will be done. For example, magenta couplers include 5-pisazolone couplers, pyrazolobenzimidazole couplers, cyanoacetylcoumarone couplers, open-chain acylacetonitrile couplers, etc., and yellow couplers include,
Examples of cyan couplers include acylacetamide couplers (eg, benzoylacetanilides and pivaloylacetanilides), and naphthol couplers and phenol couplers.
These couplers are preferably non-diffusible and have a hydrophobic group called a ballast group in their molecules, or are polymerized. The coupler may be either 4-equivalent or 2-equivalent to silver ions. It may also be a colored coupler that has a color correction effect or a coupler that releases a development control agent during development (so-called DIR coupler). Further, a method for forming an image by releasing a mobile dye by utilizing a coupling reaction with a reducing agent oxidized by a redox reaction with halogenated silver or an organic silver salt at high temperature is disclosed in European Patent No. 79056.
No. 3,217,853 and European Patent No. 67,455. In addition, a method of introducing a nitrogen-containing heterocyclic group into a dye, forming a silver salt, and making the dye advantageous through heat development is described in Research Disclosure Magazine, May 1978 issue 54.
Described on page 58 RD-16966. Furthermore, regarding the method of forming positive color images using the photosensitive silver dye bleaching method, see, for example, Research Disclosure Magazine, April 1976 issue, pages 30-32 (RD-14433), December 1976 issue, pages 14-15 of the same magazine. Page (RD-15227), U.S. Pat. No. 4,235,957, and others, useful dyes and bleaching methods are described. Regarding the method of forming color images using leuco dyes, for example, British Patent No. 3985565,
No. 4022617. Furthermore, in recent years, various new materials and methods for forming color images using heat development have been proposed, and these materials are particularly preferably used in the present application. Regarding the method using a dye-donating substance that undergoes a redox reaction with silver halide or an organic silver salt at high temperature, and as a result, a mobile dye is released,
European Patent No. 76492, West German Patent No. 3215485, European Patent No. 66282, Japanese Patent Application No. 58-28928, 58-
No. 26008. The dye-donating substances used in these methods include the following. The dye-donating substance useful in the present invention is represented by the following formula (). D-Y () Here, D represents a dye moiety or its precursor moiety, and Y is a functional substrate that changes the diffusivity of the dye-donating substance () by the redox reaction caused in the heat development process. represents. "Diffusivity changes" means that (1) the compound () is originally non-diffusible, and this changes to diffusivity, or a diffusible dye is released. or
(2), an originally diffusible compound () changes to non-diffusible. It means that. Also, this change is Y
Depending on the nature of Y, it may occur when Y is oxidized or reduced, and both can be used appropriately. Examples of changes in diffusivity due to oxidation of Y include P-sulfonamide naphthols (including p-sulfonamide phenols),
33826, 53-50736 Specific examples are described in European Patent No. 76492), O-sulfonamide phenols (including O-sulfonamide phenols, JP-A-51-113624, JP-A-56-12942, JP-A-56) −16130, same
56-16131, 57-4043, 57-650, US,
4053312 (Specific examples are described in European Patent No. 76492),
Hydroxysulfonamide heterocycles (Japanese Patent Application Laid-open No. 1983-
No. 104343 (Specific examples are described in European Patent No. 76492), 3-sulfonamindoles (Japanese Patent Application Laid-open No.
-104343, 53-46730, 54-130122, 57-
No. 85055 (Specific examples are described in European Patent No. 76492)
Examples include so-called dye-releasing redox substrates such as. Another example is JP-A No. 57-119, which releases a dye by intramolecular nucleophilic attack after Y is oxidized.
Examples include the intramolecularly assisted substrate described in Japanese Patent Application No. 20735/1977-177148. Another example is a substrate that releases a dye by an intramolecular ring-closing reaction under basic conditions, but does not substantially release the dye when Y is oxidized. (Specific examples are described in JP-A-51-63618. Furthermore, as a modification of this, a substrate in which the isoxazolone ring is re-wound by a nucleophilic reagent and releases a dye is also useful. (JP-A-51-63618)
-111628, No. 52-4819 have specific examples) Another example is that under basic conditions, the dye moiety is released due to the dissociation of acidic protons, but when Y is oxidized, the dye is substantially released. Substrates that are no longer resistant to oxidation can be mentioned. (Unexamined Japanese Patent Publication No. 53-69033, No. 54-
130927) On the other hand, examples of the diffusivity changing due to reduction of Y include the nitro compound described in JP-A-53-110827; issue,
Quinone compounds described in US Pat. Nos. 4,356,249 and 4,358,525 can be mentioned. These are reduced by the reducing agent (referred to as electron donor) that remains unconsumed during the heat development process.
The resulting molecular attack of the nucleophilic group releases the dye. As a modification of this, a quinone-type substrate is also useful, in which the dye moiety is released by dissociating the acidic protons of the reduced product. (Special Prize 54-
130927 and No. 56-164342) When using a substrate that changes its diffusive image upon reduction, an appropriate reducing agent is used to mediate the bonding between the silver salt oxidizing agent and the dye-donating substance. (electron donor)
It is essential to use , and specific examples thereof are described in the above-mentioned publicly known materials. Further, a substrate in which an electron donor coexists in the substrate Y (referred to as an LDA compound) is also useful. Furthermore, as another image material, a material that undergoes an oxidation-reduction reaction with silver halide or an organic silver salt at high temperature, and as a result, the mobility of the compound having a dye portion changes can be used. It will be written down. In addition, regarding materials that release mobile dyes by reaction with silver ions in sensitive materials, patent application No. 58-55692
It is stated in the number. Many of the above-mentioned materials are heat-developed to form an image-like distribution of movable dyes corresponding to exposure in the light-sensitive material, and these image dyes are transferred to a dye-fixing material (so-called diffusion transfer) for visualization. For information on how to do this, please refer to the patents cited above or
It is described in Japanese Patent Application No. 58-42092, No. 58-55172, etc. In the present invention, the dye-donating substance is
It can be introduced into the layer of the photosensitive material by a known method such as the method described in No. 2322027. In this case, the following high boiling point organic solvents and low boiling point organic solvents can be used. For example, phthalic acid alkyl esters (dibutyl phthalate, dioctyl phthalate, etc.), phosphoric acid esters (diphenyl phosphate, triphenyl phosphate, tricresyl phosphate, dioctyl butyl phosphate), citric acid esters (e.g. acetyl tributyl citrate) ,
High boiling point organic solvents such as benzoic acid esters (octyl benzoate), alkylamides (e.g. diethyl laurylamide), fatty acid esters (e.g. dibutyethyl succinate, dioctyl azelate), trimesic acid esters (e.g. tributyl trimesate) , or boiling point approximately 30℃ to 160℃
After dissolving in an organic solvent such as lower alkyl acetate such as ethyl acetate or butyl acetate, ethyl propionate, secondary butyl alcohol, methyl isobutyl ketone, β-ethoxyethyl acetate, methyl cellosolve acetate, cyclohexanone, etc., the hydrophilic colloid is prepared. distributed to It may be mixed and dissolved with the above-mentioned high boiling point organic solvent. Further, the dispersion method using a polymer described in Japanese Patent Publication No. 51-39853 and Japanese Patent Application Laid-Open No. 51-59943 can also be used.
In addition, various surfactants can be used when dispersing the dye-donating substance in the hydrophilic colloid, and these surfactants include those listed as surfactants elsewhere in this specification. You can use it. The amount of the high boiling point organic solvent used in the present invention is 10 g or less, preferably 5 g or less per 1 g of the dye-providing substance used. A dye transfer aid can be used to transfer the dye from the photosensitive layer to the dye fixed layer. In the method of supplying the dye transfer aid externally, water, caustic soda, caustic potash,
A basic aqueous solution containing an inorganic alkali metal salt is used. Further, a low boiling point solvent such as methanol, N,N-dimethylformamide, acetone, diisobutyl ketone, or a mixed solution of these low boiling point solvents and water or a basic aqueous solution is used.
The dye transfer aid may be used in such a way that the image-receiving layer is wetted with the transfer aid. If the transfer location is built into the photosensitive material or dye-fixing material, there is no need to supply a transfer aid from the outside.
The above transfer aid may be incorporated into the material in the form of crystal water or microcapsules, or may be incorporated as a precursor that releases the solvent at high temperatures. More preferably, a hydrophilic thermal solvent that is solid at room temperature and soluble at high temperature is incorporated into the light-sensitive material or dye-fixing material. The hydrophilic thermal solvent may be incorporated into either the photosensitive material or the dye fixing material, or may be incorporated into both. Further, the layer to be incorporated may be an emulsion layer, an intermediate layer, a protective layer, or a dye fixing layer, but it is preferably incorporated in the dye fixing layer and/or a layer adjacent thereto. Examples of hydrophilic heat solvents include ureas, pyridines, amides, sulfonamides, imides, alcohols, oximes, and other heterocycles. Example 1 Method for preparing emulsion of thermally decomposable organic silver salt (3) 28 g of gelatin and 16.2 g of phenylpropiolic acid
Dissolve in 3000ml of water. This solution is kept at 40°C and stirred. A solution of 17 g of silver nitrate dissolved in 100 ml of water is added to this solution over 2 minutes. Adjust the pH of this solution and allow it to settle to remove excess salt. Then the PH
6.0, and a yield of 400 g of silver phenylpropiolate emulsion was obtained. Preparation of silver iodobromide emulsion Dissolve 40 g of gelatin and 26 g of KBr in 3000 ml of water. The solution is kept at 50°C and stirred. Then silver nitrate
A solution of 34 g dissolved in 200 ml of water is added to the above solution over a period of 10 minutes. Then, a solution of 3.3 g of KI dissolved in 100 ml of water was added over 2 minutes. The pH of the silver iodobromide emulsion thus prepared is adjusted, and excess salt is removed by sedimentation. Thereafter, the pH was adjusted to 6.0 to obtain a silver iodobromide emulsion with a yield of 400 g. A coating solution having the following composition was coated on a polyethylene terephthalate support to a wet film thickness of 60 μm and dried to prepare a photosensitive material (A). Silver iodobromide emulsion 10g Pyrolyzable organic silver salt (3) emulsion 30g Gelatin (10% aqueous solution) 10g Hydroquinone (5% aqueous solution) 15ml Polyethylene glycol surfactant (5% aqueous solution) 5ml This photosensitive material was used in a tungsten light bulb. used, 2000
Imagewise exposure was made for 5 seconds at lux. Afterwards, when heated uniformly for 10 seconds on a heat block heated to 140℃, a negative brown image was obtained, and its maximum density was
0.94, and the minimum concentration was 0.19. For comparison, a coating solution was prepared by removing the thermally decomposable organic silver salt (3) emulsion of the present invention from the above coating solution and adding 30 g of the corresponding aqueous gelatin solution, and applying and drying in the same manner to obtain a photosensitive material (B).
It was created. Then, when exposed and heated in the same manner, an image with a maximum density of 0.27 and a minimum density of 0.12 was obtained. It was shown that the thermally decomposable organic silver salt (3) of the present invention provides images with high density. Example 2 In place of the emulsion of thermally decomposable organic silver salt (3) used in Example 1, a thermally decomposable organic silver salt prepared as follows was used.
(3) was used. Another method for preparing thermally decomposable organic silver salt (3) Phenylpropiolic acid 7.4% in 100ml of a solvent consisting of 50% methanol and 50% distilled water by volume
g was dissolved. Separately, a solution was prepared by dissolving 8.0 g of silver nitrate in 100 ml of distilled water, and the solution was mixed with the phenylpropiolic acid solution and stirred. After adjusting the pH to 6.0, the white precipitate formed was filtered to obtain silver phenylpropiolate (3). A coating material having the following composition was coated on a polyethylene terephthalate support to a wet film thickness of 60 μm and dried to prepare a photosensitive material. Silver iodobromide emulsion (as described in Example 1) 10g Pyrolizable organic silver salt (3) 2g Gelatin (10% aqueous solution) 20g Hydroquinone (5% aqueous solution) 15ml Polyethylene glycol surfactant (5% aqueous solution) 5ml Distilled water 20 ml After exposure and heating in the same manner as in Example 1, a brown developed image having a maximum density of 0.89 and a minimum density of 0.21 was obtained. This shows that a useful decomposable organic silver salt can be obtained simply by mixing and filtering a thermally decomposable organic acid solution and a silver nitrate solution. Example 3 The maximum and minimum densities of images obtained by carrying out exactly the same operations as in Example 2 except that the following thermally decomposable organic silver salts prepared in the same manner as in Example 2 were used are shown.
The color tone of all images was brown to gray-black.

[Table] It can be seen that the thermally decomposable organic silver salt of the present invention has high concentration and low fog. Example 4 Pyrolyzable organic silver salt prepared as described in Example 1
(3) The emulsion was prepared. A light-sensitive material was prepared in the same manner as in Example 1, except that a silver iodobromide emulsion (described in Example 1) to which 3 ml of a 0.04% by weight methanol solution of a highly sensitizing dye expressed by the following formula was used was used. Created. This photosensitive material was also imagewise exposed for 5 seconds at 200 lux. After that, it was heated uniformly for 10 seconds on a heat block heated to 140℃, and the maximum concentration was
An image with a minimum density of 0.99 and a minimum density of 0.21 was obtained. Furthermore, compared to Example 1, the photographic sensitivity could be increased approximately twice. This shows that even when the thermally decomposable organic silver salt of the present invention is used, the photographic sensitivity can be increased by adding a spectral image ring dye. Example 5 A photosensitive material was prepared in the same manner as in Example 1, except that 15 ml of 4-hydroxymethyl-4-methyl-1-phenyl-3-pyrazolizone (10% methanol solution) was used instead of hydroquinone (5% aqueous solution). Created. When exposed and heated in the same way, the maximum density
0.98, and a brown image with a minimum density of 0.22 was obtained. This shows that the 3-pyrazolidone compound is effective as a developer. Example 6 Preparation of photosensitive silver bromide-containing thermally decomposable organic silver salt (40) emulsion 6 g of 1,4-phenylene-bispropiolic acid and 10 g of gelatin are dissolved in 1000 ml of water. This solution is kept at 40°C and stirred. Next, a solution of 8.5 g of silver nitrate dissolved in 100 ml of water is added to the above solution over a period of 2 minutes. Next, a solution of 1.2 g of potassium bromide dissolved in 50 ml of water is added over 2 minutes. The prepared emulsion is sedimented by pH adjustment to remove excess salt. Then the pH of the emulsion
adjusted to 6.0. The yield was 200g. 1,4-phenylene-bispropiolic acid 6g
A silver bromide emulsion containing silver benzotriazole was prepared in exactly the same manner except that 6.5 g of benzotriazole was used instead of. Preparation of gelatin dispersion of coupler 2-dodecylcarbamoyl-1-naphthol 5
g, 0.5 g of sodium succinate-2-ethyl-hexyl ester sulfonate, and 2.5 g of trire cresyl phosphate (TCP), and 30 ml of ethyl acetate.
was added and dissolved. 10% of this solution and gelatin
Stir and mix 100g of the solution, and use a homogenizer to
Dispersed for 10,000 RPM. A coating having the composition shown below was coated on a polyethylene terephthalate support to a wet film thickness of 60 μm and dried to prepare a photosensitive material (C). (a) Pyrolyzable organic silver salt containing photosensitive silver bromide (40)
Emulsion 10g (b) Gelatin dispersion of coupler 3.5g (c) 0.25g guanidine trichloroacetic acid dissolved in 2.5cc ethanol (d) Gelatin (10% aqueous solution) 5g (e) 2,6-dichloro-p- aminophenol
0.2 g of liquid dissolved in 15 c.c. water.
Imagewise exposure was made for 5 seconds at lux. Thereafter, when the film was heated uniformly for 20 seconds on a heat block heated to 140°C, a negative cyan image was obtained. When this concentration was measured using a Macbeth transmission thermometer (TD-504), the minimum concentration was 0.28 and the maximum concentration was 2.10. Next, instead of the above-mentioned photosensitive silver bromide-containing thermally decomposable organic silver salt (40) emulsion, a silver bromide emulsion containing benzodriazole silver and 10 g of the following silver bromide emulsion were added.
A coating solution exactly the same as that for photosensitive material (C) was prepared except that each of
It was created. Preparation of silver bromide emulsion Dissolve 10 g of gelatin and 7.2 g of KBr in 1000 ml of water. This solution is kept at 40°C and stirred. Then silver nitrate
A solution of 8.5 g dissolved in 100 ml of water is added to the above solution over a period of 2 minutes. The prepared emulsion is sedimented by pH adjustment to remove excess salt. Thereafter, the pH of the emulsion was adjusted to 6.0. The yield was 200g. When exposed and heated in the same manner as the photosensitive material (C), the maximum density was 1.72 and the minimum density was 0.25 for the photosensitive material (D), and the maximum density was 0.15 and the minimum density was 0.12 for the photosensitive material (E).
It was hot. As described above, it can be seen that the thermally decomposable organic silver salt of the present invention is useful not only for black and white light-sensitive materials but also for heat-developable color light-sensitive materials in which dye images are obtained by a coupling reaction. It can also be seen that the development speed is faster than that of conventional organic silver salts. The following example shows an application to a system that releases a diffusible dye through a coupling reaction. Example 7 Method for preparing a gelatin dispersion of a dye-donating substance 10g of a dye-donating substance having the following structure, As a surfactant, we weighed 0.5 g of sodium succinate-2-ethyl-hexyl ester sulfonate and 4 g of trire cresyl phosphate (TCP),
Add 20 ml of cyclohexanone and heat to dissolve at about 60°C to make a homogeneous solution. This solution and 100 g of a 10% solution of lime-treated gelatin were stirred and mixed, and then dispersed using a homogenizer at 10,000 RPM for 10 minutes. Next, a method for preparing a photosensitive coating liquid will be described. (a) Pyrolyzable organic silver salt containing photosensitive silver bromide (40)
Emulsion (as described in Example 7) 10 g (b) Dispersion of dye-donating substance 3.5 g (c) Guanidine trichloroacetic acid (10% ethanol solution) 2.5 ml (d) Gelatin (10% aqueous solution) 5 g (e) 2 ,6-dichloro-4-aminophenol
More than a solution of 200ml dissolved in 2ml methanol
After mixing and dissolving (a) to (e), the mixture was coated on a polyethylene terephthalate film to a wet film thickness of 30 μm and dried. Furthermore, the following composition was coated as a protective layer on top of this to a wet film thickness of 25 μm and dried. This photosensitive material is referred to as (F). (a) 10% gelatin aqueous solution 35 g (b) 1% aqueous solution of succinic acid-2-ethyl-hexyl ester sulfonic acid in soda 4 ml (c) Guanidine trichloroacetic acid (10% ethanol) 4 ml (d) Distilled water 57 ml The above exposure A coating solution having exactly the same composition was prepared, except that 10 g of the photosensitive silver bromide emulsion described in Example 7 was used instead of the thermally decomposable organic silver salt (40) emulsion containing silver bromide, and the coating solution was coated and dried. A photosensitive material (G) was prepared. Manufacturing method of dye fixing material Poly(methyl acrylate-co-N,N,N-trimethyl-N-vinylbenzylammonium chloride) (ratio of methyl acrylate and vinylbenzylammonium chloride is 1:1) 10g is mixed with 1.5 g of sodium carbonate. % dissolved in 200ml of aqueous solution, 10%
100 g of lime-treated gelatin was mixed uniformly. This mixed solution was uniformly applied to a wet film thickness of 90 μm on a paper support laminated with polyethylene in which titanium dioxide was dispersed, and then dried. This sample is used as a dye fixing material having a mordant layer. The above photosensitive materials (F) and (G) were imagewise exposed for 10 seconds at 2000 lux using a tungsten bulb. after that
The mixture was heated uniformly for 20 seconds on a heat block heated to 150°C. After soaking the dye-fixing material in water, it was superimposed on the above-mentioned heated photosensitive material so that the film surfaces were in contact with each other. After heating for 6 seconds on a heat block at 80°C, the dye-fixing material was peeled off from the light-sensitive material, and a negative magenta dye was obtained on the image-receiving material. The density of this negative image was measured using a Macbeth reflection densitometer (RD-519).
When measured using
An image with a minimum density of 2.15 and a minimum density of 0.26 was obtained, but the maximum density of the photosensitive material (G) was only 0.16. Example 8 Method for preparing a gelatin dispersion of a dye-donating substance 5 g of a reducible dye-releasing agent having the following structure, 4 g of an electron-donating substance with the following structure, 20 ml of cyclohexanone was added to 0.5 g of sodium succinate 2-ethyl-hexyl ester sulfonate and 10 g of tri-gresyl phosphate (TCP), and the mixture was heated and dissolved at about 60°C. This solution and 100 g of a 10% solution of gelatin are stirred and mixed, and then dispersed using a homogenizer at 10,000 RPM for 10 minutes. Next, a method for preparing a photosensitive coating liquid will be described. (a) Pyrolyzable organic silver salt containing photosensitive silver bromide (40)
Emulsion (as described in Example 7) (b) 3.5 g of a dispersion of a dye-donating substance (c) A solution of 250 mg of guanidine trichloroacetic acid dissolved in 2 ml of ethanol (d) 1.5 ml of a 5% aqueous solution of the following compound The above (a) to (d) were mixed with 2 ml of water, heated and dissolved, and then coated on a polyethylene terephthalate film to a wet film thickness of 30 μm and dried to prepare a photosensitive material (H). Furthermore, a coating solution having exactly the same composition was used, except that 10 g of the photosensitive silver bromide emulsion described in Example 7 was used instead of the photosensitive silver bromide-containing thermally decomposable organic silver salt (40) emulsion described above. A photosensitive material () was prepared by preparing, coating, and drying. Light-sensitive materials (H) (I) using a tungsten bulb, 2000
Imagewise exposure was made for 10 seconds at Lux. Thereafter, it was heated uniformly for 30 seconds on a heat block heated to 130°C. The dye-fixing material described in Example 8 was immersed in water, and then superimposed on the heated photosensitive material described above so that the film surfaces were in contact with each other. A positive magenta color image was obtained on the dye fixing material. The density of this positive image was measured using a Macbeth reflection densitometer (RD-519), and the maximum density for green light was 1.82 for the light-sensitive material (H) and 0.31 for the minimum density, but the maximum density for the light-sensitive material (H) was 0.31. The concentration was 1.90. It can be seen that the thermally decomposable organic silver of the present invention is effective.

Claims (1)

[Scope of Claims] 1. A photothermographic material characterized by containing a thermally decomposable organic silver salt represented by the following general formula (2). General formula (2) R ⁰ -(C≡C-CO ₂ )m・mAg In the formula, R ⁰ is a hydrogen atom, an alkyl group, a substituted alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted aryl group. group, heterocyclic residue, substituted heterocyclic residue, aralkyl group, substituted aralkyl group, acyl group, alkoxycarbonyl group,
Carbamoyl group, substituted carbamoyl group, -CO ₂ M
(M is an alkali metal), a monovalent residue selected from CO ₂ B (B is a conjugate acid of an organic base or a quaternary ammonium group), or an alkylene group, an arylene group, a heterocyclic divalent residue represents a divalent residue selected from m represents 1 or 2.