JP2791333B2 - Heat developable photosensitive material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-developable light-sensitive material, and more particularly to an improved heat-developable light-sensitive material having high illuminance failure.

[0002]

2. Description of the Related Art Silver halide photographic materials which are subjected to a wet development process are excellent in terms of photosensitivity, gradation, image quality, etc. as compared with other photographic materials, for example, electrophotography and diazo photography, and are widely used. I have been. However, in the wet development processing, handling such as preparation of a processing solution, management of processing temperature and time is complicated. Further, in recent years, gas lasers or semiconductor lasers have become popular as light sources, and further simplification and shortening of processing are desired. In order to eliminate the complexity of such wet processing, a heat developable photosensitive material by heat development has been known. This heat-developable photosensitive material is described in, for example, “Basics of Photographic Engineering / Non-Silver Photography” (1982 published by Corona Co., Ltd.).
42-255, JP-B-43-4921 and JP-B-43-4923. However, the technique of the photothermographic material cannot be used due to high illuminance failure in image writing by high illuminance by laser or the like and short exposure. The reason for this is that the method of producing the photosensitive silver halide in an organic solvent for the heat-developable photosensitive material is essentially different from that of the wet-type silver halide photosensitive material, and the conventional techniques for improving reciprocity failure, for example, Japanese Patent Publication No. 43-4935, Japanese Patent Publication No.
This is because the technique of doping heavy metals described in JP-A-49-33781 cannot be applied as it is. In order to overcome such problems, the present inventors have filed Japanese Patent Application No.
Japanese Patent No. 403626 proposes a technique for improving high illuminance failure characteristics by using a photosensitive silver halide containing a large amount of iridium mainly on the surface side as a heat developable photosensitive element. Further, in Japanese Patent Application No. 3-165643, in the photosensitive silver halide described in Japanese Patent Application No. 2-403626, a smaller amount of iridium than iridium contained on the surface side is simultaneously contained inside the photosensitive silver halide. A technique was proposed to improve the high illuminance failure characteristics by distributing different concentrations of iridium ions in the included silver halide crystal grains. According to these inventions, the effect of improving the high illuminance failure characteristics is recognized, but according to subsequent studies, in order to bring about sufficient improvement of the high illuminance failure characteristics,
A large amount of iridium is required compared to the amount of iridium added to silver halide used for conventional wet development processing, and therefore high illuminance failure characteristics are improved, but with a slight increase in fog density. Phenomena were seen. Then, it was also found that when the amount of iridium added was reduced, the adverse effect of increasing the fog density was eliminated, but the tendency for the improvement of the high illuminance failure property to be insufficient.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a heat-developable light-sensitive material which has improved high-light intensity failure, has less fog, and exhibits high image density.
High-speed image writing (1 ×
An object of the present invention is to provide a heat-developable light-sensitive material capable of producing a heat-developable light-sensitive material at a rate of 10 ⁻⁵ to 1 × 10 ⁻⁷ sec / dot.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a support comprising at least (1) a photosensitive silver halide, (2) an organic silver salt, (3) a reducing agent and (4) a binder. In a heat-developable photosensitive material in which a developable photosensitive element is formed in a single layer or a multilayer, (1) the photosensitive silver halide is a silver ion donor.
(a) and a halogen ion donor (b) are reacted in an organic solvent (c) to produce a silver ion donor (a) and a halogen ion donor (b). Up to 90% of the iridium ion donor (d) to 5 × 10 ^-7 to 5 ×
10 was added at ^-5 molar ratio of further remaining reactive total silver ion donor according iridium ion donor (d) is a response in 10% of the process (a) with respect to 5 × 10 ^-5 from 5 × 10 ^{- 3} containing iridium ions produced by adding at a molar ratio of ³ , and the heat-developable photosensitive element has the following general formula (I), (II),
This was achieved by containing at least one compound represented by (III) or (IV). Formula (I) R ₁ -COOM _{1 In the} formula, R ₁ represents a linear or branched alkyl group, alkenyl group or aralkyl group, and M ₁ represents sodium or potassium.

[0005] formula _{(II) M 2 OOC-R} 2 -COOM 3 formula (III) M ₂ OOC-COOM ₃ wherein, R ₂ represents a linear or branched alkylene group or alkenylene group, M ₂ and M ₃ represents hydrogen, sodium or potassium (however, M ₂ and M ₃ are not simultaneously hydrogen). General formula (IV) M ₄ —OH In the formula, M ₄ represents sodium or potassium.

The general formulas (I), (II), (III) and (IV)
However, the compounds are not limited to these compounds. (1) CH ₃ COONa (2) CH ₂ = CHCOONa (3) CH ₃ CH ₂ COONa (4) CH ₃ (CH ₂ ) ₂ COONa (5) (CH ₃ ) ₂ CHCH ₂ COONa (6) CH ₃ CH = CHCH = CHCOONa (7) CH ₃ (CH ₂ ) ₄ COONa (8) CH ₃ (CH ₂ ) ₃ CH (CH ₃ ) COONa (9) CH ₃ (CH ₂ ) ₆ COONa (10) CH ₃ (CH ₂ ) ₈ COONa (11) CH ₃ (CH ₂ ) ₁₀ COONa (12) CH ₃ (CH ₂ ) ₁₂ COONa (13) CH ₃ (CH ₂ ) ₁₄ COONa

[0007]

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(15) CH ₃ (CH ₂ ) ₄ CH = CHCH ₂ CH = CH (CH ₂ ) ₇ COONa (16) CH ₃ (CH ₂ ) ₁₆ COONa (17) CH ₃ (CH ₂ ) ₁₈ COONa (18 ) CH ₃ (CH ₂ ) ₂₀ COONa (19) NaOOC-COONa (20) NaOOCCH ₂ COONa (21) HOOCCH ₂ CH ₂ COONa (22) HOOC (CH ₂ ) ₈ COONa (23) CH ₃ COOK (24) CH ₂ = C (CH ₃ ) COOK (25) CH ₃ (CH ₂ ) ₃ COOK (26) (CH ₃ ) CCOOH (27) CH ₃ CH = CHCH = CHCOOK (28) CH ₃ (CH ₂ ) ₄ COOK (29) CH ₃ (CH ₂ ) ₈ COOK (30) CH ₃ (CH ₂ ) ₉ COOK (31) CH ₃ (CH ₂ CH = CH) ₃ (CH ₂ ) ₇ COOK (32) CH ₃ (CH ₂ ) ₇ CH = (CH ₂ ) ₇ COOK (33) CH ₃ (CH ₂ ) ₁₈ COOK (34) CH ₃ (CH ₂ ) ₂₀ COOK (35) KOOCCH = CHCOOK (36) KOOCCH ₂ COOK (37) HOOCCH ₂ CH ₂ COOK (38 ) HOOCCH ₂ C (= CH ₂ ) COOK (39) KOOC (CH ₂ ) ₄ COOK (40) KOOC (CH ₂ ) ₇ COOK (41) HOOC (CH ₂ ) ₈ COOK (42) KOH (43) NaOH The method of adding the compound is not particularly limited, but is preferably dissolved in an organic solvent such as methanol,
It is preferably added to a vigorously stirred heat developable photosensitive material coating solution. The preferred range of the amount of the compound of the present invention is from 0.001 mol to 0.1 mol, particularly preferably from 0.01 mol to 0.05 mol, per mol of the organic silver salt. The heat-developable photosensitive element used in the present invention imparts photosensitivity and is further subjected to high-speed image writing (1 × 10 ⁻⁵ sec to 1 ×)
10 ^-7 sec / dot), which contains an important element for providing a heat-developable photosensitive material capable of achieving a high illuminance failure, which is a photosensitive silver halide.

Hereinafter, (1) the photosensitive silver halide used in the present invention will be described in detail. The photosensitive silver halide used in the present invention is obtained by reacting a silver ion supplier (a) and a halide ion supplier (b) in an organic solvent (c) to form iridium ions (d) in silver halide grains. A silver halide which contains the iridium ion donor (d) in the reaction by 90% of the reaction process between the silver ion donor (a) and the halogen ion donor (b). A molar ratio of 5 × 10 ⁻⁷ to 5 × 10 ⁻⁵ is added to the ion donor (a), and the iridium ion donor (d) is supplied to all the silver ions involved in the reaction in 10% of the remaining reaction process. 5 × 10 ^-5 for body (a)
To 5 × 10 ^{-3 in} a molar ratio. The photosensitive silver halide useful in the present invention is
Silver chloride, silver bromide, silver chlorobromide, silver iodobromide, silver iodochloride, silver iodochlorobromide, and particularly preferred is photosensitive silver halide in which 90 mol% or more is silver bromide.

Known methods can be applied to the method for producing the photosensitive silver halide of the present invention. This preparation method is described, for example, in U.S. Pat.
No. 58-21249, No. 55-1567, No. 2-4889,
Japanese Patent Publication No. 2-6045, Japanese Patent Publication No. 2-7446, Japanese Patent Publication No. 2-7447
No. and other publications.

Examples of the silver ion donor (a) of the photosensitive silver halide used in the present invention include an inorganic silver compound soluble in an organic solvent, in particular, a polar organic solvent described later, and a soluble or soluble in a polar organic solvent. And a dispersible organic silver compound. Specific examples of the compound include inorganic silver salts such as silver perchlorate and silver nitrate, silver complex salts such as silver ammonium complex salt and silver amine complex salt, silver acetate, silver trifluoroacetate, silver propionate, silver caprate, and silver laurate. Silver, silver myristate, silver palmitate, silver stearate, silver behenate, silver adipate,
Silver sebacate, silver benzotriazole, silver saccharin,
Silver phthalazinone, 3-mercapto-4-phenyl-1,2,
4-triazole silver, 4-hydroxy-6-methyl-1,
Organic silver salts such as silver 3,3a, 7-tetrazaindene and silver salt of 2- (S-ethylthioglycolamide) -benzothiazole.

Examples of the photosensitive silver halide donor (b) for use in the present invention include inorganic solvents or organic halogen compounds soluble in organic solvents, particularly polar organic solvents or polar organic solvents including water. Compound. Specific examples of the compound include, as the inorganic halogen compound, a compound represented by the general formula MXn. Wherein M is a hydrogen atom or a metal atom (for example, strontium, cadmium, zinc, sodium,
Barium, cesium, calcium, iron, nickel, magnesium, potassium, aluminum, antimony, gold,
Cobalt, mercury, expressed lead, beryllium, lithium, indium <br/> arm, rhodium, palladium, platinum, bismuth, etc.), X is a chlorine atom, a bromine atom and an iodine atom, n represents the valence of the cation Is shown. As inorganic halogen compounds,
Further, halogen-containing metal complexes, for example, K ₂ PtCl ₆ , K ₂ PtBr ₆ ,
HAuCl ₄ , (N H ₄ ) ₃ RuCl ₆ , K ₃ Rh Cl _{6 and the} like can be mentioned. Examples of the organic halogen compound include a compound represented by the following general formula (V) or (VI).

[0013]

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In the formula, X represents a chlorine atom, a bromine atom and an iodine atom, and Z represents a group of non-metallic atoms necessary for forming a 4- to 8-membered ring. It may be condensed. Z is preferably a 5- or 6-membered ring, and specific examples include a pyrrole ring, a pyrroline ring, a pyrrolidine ring,
Examples include an imidazoline ring, an imidazolidine ring, a pyrazoline ring, an oxazolidine ring, a piperidine ring, an oxazine ring, a piperazine ring, and an indoline ring. further
Z may form a 4- to 8-membered lactam ring, hydantoin ring, cyanuric ring, hexahydrotriazine ring, indoline ring or the like. Further, this ring may have a substituent such as an unsubstituted or substituted alkyl group, an unsubstituted or substituted aryl group, an alkoxy group, a halogen atom, and an oxo group. A represents a carbonyl group or a sulfonyl group; R ₃ and R ₄ represent a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or substituted aryl group, or an alkoxy group.

As typical examples of the compound represented by the general formula (V), N-bromosuccinimide, N-bromotetrafluorosuccinimide, N-bromophthalimide,
N-Bromglutarimide, 1,3-dibromo-5,5-
Dimethyl-2,4-imidazolidinedione, N, N'-dibromo-5,5-diethylbarbituric acid, N-bromoisocyanuric acid, N, N'-dibromoisocyanuric acid, N-bromooxazolinone, N -Bromophthalazinone, N-chlorosuccinimide, N-iodosuccinimide, N-chlorophthalimide, N-bromosaccharin, N-bromocaprolactam, N-bromobutyrolactam, N, N'-dibromothiohydantoin, etc. Can be mentioned.

As typical examples of the compound represented by the general formula (VI), N-bromoacetamide, N-bromoacetanilide, N-bromobenzenesulfonylanilide,
N-bromobenzamide, N-chloroacetamide, N
-Bromonaphthamide, N-bromo-P-hydroxybenzamide and the like.

Also, halogenated melamine can be used as the organic halogen compound, and specific examples thereof include tribromomelamine and trichloromelamine. Further, as an organic halogen compound, the following general formula (VII)
A C-halogeno compound represented by is also effective.

[0018]

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In the formula, X represents a chlorine atom, a bromine atom or an iodine atom, and R ₅ , R ₆ and R ₇ may be the same or different from each other and include a hydrogen atom, an unsubstituted or substituted alkyl group, an unsubstituted or Represents a substituted aryl group, a nitro group, an acyl group, an unsubstituted or substituted amide group, a sulfonyl group bonded to an unsubstituted or substituted aryl group or an alkyl group, or a halogen atom. However, at least one of R ₅ , R ₆ , and R ₇ assists in releasing a halogen atom, and represents, for example, a nitro group, an unsubstituted or substituted aryl group, an alkenyl group, an acyl group, an amide group, a sulfonyl group, and the like. .

The compounds represented by the above general formula (VII) include α-haloketone compounds, α-haloamide compounds,
Examples include halosulfonyl compounds, halonitro lower alkane compounds, and compounds having an unsaturated bond at the β-position carbon to a halogen atom. Specific examples of the compound represented by the general formula (VII) include α-bromoacetophenone, α-chloroacetophenone, α-bromo-α-phenylacetophenone, α-bromo-1,3-diphenyl-
1,3-propanedione, α-bromo-2,5-dimethoxyacetophenone, α-bromomethylsulfonylbenzene, α-bromo-α-benzenesulfonylacetamide, α-chloro-α- (p-tolylsulfonyl) acetamide, α -Bromo-γ-nitro-β-phenylbutyrophenone, α-iodo-γ-nitro-β-phenylbutyrophenone, 2-bromo-2-nitro-1,3-propanediol, 2-bromo-2-nitrotrimethylene- 1,3
-Bis (phenyl carbonate), α-bromotoluene, α, p-dibromotoluene, α, α'-dibromo-m
-Xylene, α, α, α ', α'-tetrabromo-p-
Xylene, 3-bromopropene and the like can be mentioned. Among the above compound examples, α-bromotoluene, 3
Compounds in which the carbon at the β-position of the halogen atom has an unsaturated bond, such as -bromopropene, are particularly useful.

Onium halide compounds are also useful as the halogen ion donor (b) for the photosensitive silver halide used in the present invention. Specific examples include ammonium bromide, trimethylphenylammonium chloride, cetylethyldimethylammonium bromide, and trimethylbenzyl. Examples thereof include ammonium bromide, tetraethylphosphonium bromide, and trimethylsulfonium chloride.

In the production of the photosensitive silver halide used in the present invention, the silver ion donor of component (a) and the component
(b) is mixed with a silver ion donor, and the reaction of converting all or most of the silver ion donor of component (a) to photosensitive silver halide is performed in an organic solvent. )) The amount of halogen ion donor used is
It may be a stoichiometric amount with respect to the silver ion donor of (a).
However, it is preferred to use an excess amount, that is, from about 1.0 mol to about 3.0 mol of the halogen ion donor of the component (b) per 1 mol of the silver ion donor of the component (a).

In the production of the photosensitive silver halide used in the present invention, the organic solvent (c) used for the reaction between the silver ion donor of the component (a) and the halogen ion donor of the component (b)
Is not particularly limited as long as it is liquid at the reaction temperature and can uniformly dissolve or disperse the silver ion donor of the component (a) and dissolve a certain amount of the halogen ion donor of the component (b). Specifically, alcohols, ketones, aliphatic hydrocarbons, aromatic hydrocarbons, esters, ethers, acid amides and the like can be used alone or as a mixture.

Specific examples of alcohols include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol,
Isobutyl alcohol, sec-butyl alcohol, n-
Aliphatic saturated alcohols such as amyl alcohol, isoamyl alcohol and n-hexyl alcohol; aliphatic unsaturated alcohols such as allyl alcohol and propargyl alcohol; alicyclic alcohols such as cyclopentanol and cyclohexanol; benzyl alcohol; cinnamyl alcohol And polyhydric alcohols such as ethylene glycol and glycerin.

Specific examples of ketones include aliphatic saturated ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, isopropyl methyl ketone, butyl methyl ketone, and isobutyl methyl ketone; methyl vinyl ketone;
Examples thereof include unsaturated aliphatic ketones such as methylheptene ketone, alicyclic ketones such as cyclobutanone and cyclohexanone, and aromatic ketones such as acetophenone, propiophenone and butylphenone.

Specific examples of esters include methyl formate, propyl formate, amyl formate, ethyl acetate, methyl acetate, butyl acetate, isobutyl acetate, methyl propionate, ethyl propionate, isopropyl propionate,
Examples thereof include methyl butyrate, ethyl butyrate, ethyl isobutyrate, methyl isovalerate, isopropyl isovalerate, methyl benzoate, and ethyl phthalate.

Specific examples of ethers include saturated aliphatic ethers such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, methyl butyl ether, ethyl propyl ether, and ethyl isoamyl ether; Examples thereof include aromatic ethers such as saturated aliphatic ethers, anisole and phenyl ether, and cyclic ethers such as tetrahydrofuran and dioxane.

Specific examples of the aliphatic hydrocarbons include n-
Heptane, n-hexane, 3-methylpentane, 2,3-
Saturated aliphatic hydrocarbons such as dimethylbutane, cyclohexane and cycloheptane, and unsaturated aliphatic hydrocarbons such as cyclohexene, cyclopentadiene and cyclopentene can be mentioned.

Specific examples of aromatic hydrocarbons include benzene, toluene, xylene, chlorobenzene, indene, tetralin and the like. In addition, a solvent containing a nitrogen atom or a sulfur atom such as dimethylacetamide, dimethylformamide, and dimethylsulfoxide can also be used.

Particularly preferred among the above organic solvents are polar alcohols or ketones alone or in a mixture with the above-mentioned other solvents. Also, a mixed system of water-alcohols and water-ketones can be used.

Among the above-mentioned reaction components, in particular, as a photosensitive component of a heat-developable photosensitive material, a silver ion donor is an organic fatty acid silver salt, and a halogen ion donor is a compound represented by the general formula (V):
The combination of the N-halogeno compound represented by (VI) is particularly preferred in terms of photographic characteristics.

The reaction between the silver ion supplier (a) and the halogen ion supplier (b) is carried out by a usual reaction method, for example, a positive flow method.
The method is carried out by a backflow method or a double-mixing method.
It is selected according to the type of (b) .For example, if both (a) and (b) are soluble in the reaction solvent, the simultaneous mixing method is used.If (a) is an insoluble long-chain fatty acid silver salt, the reverse flow method is used. The method is preferred.

The iridium ion donor (d) used in the production of the photosensitive silver halide used in the present invention.
Are iridium salts or iridium complex salts of iridium trihalide, iridium tetrahalide, hexahalogenoiridium (III), hexahalogenoiridium (IV), and useful specific compounds are iridium chloride (III) ), Iridium (IV) chloride, sodium hexachloroiridate (III) dihydrate, sodium hexachloroiridium (IV) hexahydrate and the like.

Further, the iridium ion donor (d) can be added as a separate liquid from the donors (a) and (b) or mixed with (b). The method of adding each component at the time of reaction may be selected according to the purpose, such as a method of adding all at once, a method of adding intermittently, a method of adding continuously, or a method of combining them. As the solvent for the iridium ion donor (d), a polar organic solvent is preferable, and in particular, an organic solvent having good compatibility with the organic solvent (c),
For example, polar alcohols or ketones are preferred. Incidentally, water may be added to the organic solvent to make the iridium ion donor (d) easily soluble.

In the production of the photosensitive silver halide used in the present invention, a solvent-soluble polymer can be added to the reaction solution. The addition of a polymer soluble in an organic solvent causes a uniform reaction between the halogen compounds of component (a) and component (b), and prevents irregular growth and aggregation of the formed photosensitive silver halide. Can also. Polymers that can be used for this purpose include, for example, polyvinyl acetate,
Polyvinyl propionate, polymethyl methacrylate, ethyl cellulose, cellulose acetate, nitrocellulose, polyethylene, ethylene-vinyl acetate copolymer, chlorinated polyethylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, chlorinated polypropylene, polyvinyl Acetal, acrylic resin, polystyrene, epoxy resin, modified melamine resin, alkyd resin, polyamide, chlorinated rubber, acrylonitrile-butadiene-styrene terpolymer, silicon block copolymer, polyvinylpyrrolidone, polyethylene oxide, high molecular weight paraffin and JP And vinyl copolymers described in JP-A-47-9432. Preferred among the above polymers are those which can be dissolved in alcohols or ketones alone or in a mixed solvent with another organic solvent, and particularly preferably the polymers are polyvinyl acetals. The amount of the polymer soluble in the organic solvent is about 0.05 to 1 g of the silver ion donor silver salt of the component (a).
g to about 20 g, preferably from about 0.1 g to about 10 g.

Next, particularly preferred embodiments of the method for producing the photosensitive silver halide used in the present invention will be described. Under a red safe light, an organic silver salt of an organic fatty acid (eg, silver stearate) is uniformly dispersed in a polar organic solvent (eg, methyl alcohol), and a polymer soluble in the organic solvent (eg, polyvinyl butyral) is added and dissolved. Thus, a dispersion containing the polymer and the silver ion donor is prepared. This dispersion is kept at a constant temperature, and a previously prepared organic solvent solution of a halogen ion donor (for example, N-bromosuccinimide-acetone) is added to the silver ion donor involved in the reaction.
An iridium ion solution [for example, sodium hexachloroiridium (IV) hexahydrate-methanol] having a molar ratio of 5 × 10 ⁻⁷ to 5 × 10 ⁻⁵ with respect to (a) was added to the silver ion donor.
(a) and up to 90% of the reaction process of the halogen ion donor (b). Further, a solution of the iridium ion donor (d) having a molar ratio of 5 × 10 ⁻⁵ to 5 × 10 ⁻³ to the total silver ion donor (a) involved in the reaction in 10% of the remaining reaction steps was added. End the reaction process. The reaction time during this time is
It can be arbitrarily selected in the range of about 30 seconds to about 5 hours, preferably about 3 minutes to 3 hours. The photosensitive silver halide thus obtained contains iridium ions in different concentration distributions. The above-mentioned preparation has been described with reference to a preferred example, and the preparation is not limited to this as long as the photosensitive silver halide can be prepared for the purpose of designing the photothermographic material of the present invention.

Further, in the method for producing a photosensitive silver halide used in the present invention, JP-B-2-6045 and JP-B-2-74.
Particles can be controlled by involving the metal compounds disclosed in JP-A-47-47 in the reaction, and the particle diameter and particle distribution can be controlled by measuring and controlling the silver ion concentration during the reaction.

Further, in the method for producing a photosensitive silver halide used in the present invention, the reaction solution is placed in a solvent capable of precipitating the polymer used in the reaction disclosed in Japanese Patent Publication No. 2-7446 after the reaction. By mixing, reaction by-products or unreacted substances can be removed by washing.

Further, the photosensitive silver halide used in the present invention may be prepared by a known chemical sensitization method, for example, sulfur sensitization, gold sensitization,
By applying reduction sensitization or the like, the intrinsic sensitivity can be increased.

The organic silver salt used as the heat-developable photosensitive element of the present invention includes a silver salt of an organic acid or a silver salt of an organic compound having an imino group or a mercapto group.
The long-chain fatty acid silver salts are preferred because they are less susceptible to undesirable changes such as dark coloring under room light. Specific examples include silver behenate, silver stearate, silver palmitate, silver myristate, silver laurate, silver oleate, and silver hydroxystearate, among which silver behenate is most effective. .

Various reducing agents can be used as the heat-developable photosensitive element of the present invention. Generally, developing agents used in ordinary silver halide photosensitive materials, specifically, hydroquinone, methylhydroquinone, chlorohydroquinone, methylhydroxynaphthalene, N, N'-diethyl-p-phenylenediamine, aminophenol, ascorbic acid , 1-phenyl-3-pyrazolidone, etc., and in addition to these, 2,2′-methylenebis (6-t-butyl-4-methylphenol), 4,4 ′
-Butylidenebis (6-t-butyl-3-methylphenol), 4,4'-thiobis (6-t-butyl-3-methylphenol), etc .; Examples include naphthol-based reducing compounds and 4-benzenesulfonamidophenol-based compounds described in Belgian Patent No. 802518.

The binder which is the photothermographic element of the present invention is contained alone or in combination in the layer. Suitable materials for the binder can be hydrophobic or hydrophilic, and can be transparent or translucent.
Specifically, polyvinyl butyral, cellulose acetate butyrate, polymethyl methacrylate, polyvinyl pyrrolidone, ethyl cellulose, cellulose acetate, cellulose acetate, polyvinyl acetate, polyvinyl alcohol, gelatin, sulfobetaine described in Canadian Patent No. 774054 Examples having a repeating unit can be given. The amount of the binder to be used is preferably from 10: 1 to 1:10, more preferably from 4: 1 to 1: 2, by weight relative to the non-reducing organic silver salt.

In the heat-developable photosensitive element of the present invention, it is preferable to use an organic acid in order to improve the color tone of an image and the stability after image formation, and particularly, a fatty acid which is the same as or close to the silver salt of a long-chain fatty acid. Is desirable to be contained alone or in combination. The amount of the fatty acid to be used is 25 to 200 mol%, preferably 30 to 120 mol%, based on the non-reducing organic silver salt.

The heat-developable photosensitive element of the present invention can contain a suitable color tone agent. Toners for this purpose include phthalazinone or its derivatives described in U.S. Pat.No. 3,080,254, cyclic imides described in JP-A-46-6074, and JP-A-53-36774. Phthalazine dione compounds and the like are included.

In the heat-developable photosensitive element of the present invention, an appropriate heat fogging inhibitor can be used. Examples of the thermal antifoggant include mercury compounds described in JP-B-47-11113, 1,2,4-triazole compounds described in JP-B-55-42375, and JP-A-57-30828. Tetrazole compounds, benzoic acids described in JP-A-47-138630, dibasic acids represented by the general formula HOOC-R-COOH described in JP-B-64-8810 (where R is 4 or more carbon atoms) Represents an alkylene group which may be linear or branched, or an alkenylene group).

In the heat-developable photosensitive element of the present invention, a compound for preventing coloring of a non-image portion due to light or the like after image formation can be used. As the non-image area coloring inhibitor, a general formula described in JP-B-3-32057 can be used.

[0047]

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Wherein X represents a chlorine atom, a bromine atom and an iodine atom, and R ₈ represents a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, an alkoxy group or an aryloxy group; R ₉ represents hydrogen _{, a} substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group).

The photothermographic element of the present invention may contain an antistatic agent. As an antistatic agent, JP-A-64-
Examples of the surfactant include a fluorine-containing surfactant described in Japanese Patent No. 24245 or a combination of a fluorine-containing surfactant and a nonionic surfactant. The heat-developable photosensitive element of the present invention further comprises an ultraviolet absorber,
It may contain a fluorescent whitening agent, a filter dye (layer) and the like. The element according to the invention may contain a suitable spectral sensitizer. Useful sensitizing dyes include cyanine dyes, merocyanine dyes, and xanthene dyes, particularly the “Product Licensing Index” Vol. 92, No. 107
~ 110 pages (issued in December 1971) or Belgian Patent No. 77
Those described in US Pat. No. 2,371 are useful.

The photothermographic element of the present invention can be obtained by forming a coating on a suitable support. As a typical support, polyethylene, polypropylene, polyethylene terephthalate, polycarbonate, synthetic resin film such as cellulose acetate, synthetic paper, paper coated with a resin film such as polyethylene, art paper, paper such as photographic baryta paper, or Examples thereof include a metal plate (foil) such as aluminum, a synthetic resin film having a metal deposition film by a usual method, and a glass plate.

[0051]

The present invention will now be described by way of examples, which should not be construed as limiting the invention.

<Production of photosensitive silver halide> 11.0 g of silver stearate was added to isopropyl alcohol 20 under red safe light.
Dispersed in 0 ml. Further, 7.5 g of polyvinyl butyral resin was added and dissolved to prepare a polymer suspension dispersion of a silver salt. Keep the resulting dispersion of silver stearate at 50 ° C,
With stirring, 54 ml of 60 ml of an acetone solution in which 5.5 g of N-bromosuccinimide and 6.4 mg of sodium bromide were dissolved and a methanol solution (I-1) of sodium hexachloroiridium (IV) hexahydrate (Iridium salt 0.0157 mg) / Methanol 18 ml = 10 ⁻⁶ mol / silver stearate) were added simultaneously over 27 minutes. Thereafter, 6 ml of an acetone solution of the remaining N-bromosuccinimide and sodium bromide and a methanol solution (I-2) of sodium hexachloroiridium (IV) hexahydrate (1.57 mg of iridium salt / 6 ml of methanol = 10 ^-4 mo)
l / mol of silver stearate) were added simultaneously over 3 minutes.
After continuing the reaction at 50 ° C. for another 30 minutes, the liquid temperature was lowered to room temperature to prepare a silver bromide dispersion. This was poured into 1 liter of stirring water to obtain a precipitate. Filtered and dried, silver bromide containing iridium-polyvinyl butyral solid (A-1) 20.3 g
I got Furthermore, in the above-mentioned production method, a methanol solution of sodium hexachloroiridium (IV) hexahydrate (I-
Add only 6 ml of methanol instead of 1) and (I-2),
Silver bromide-polyvinyl butyral solid containing iridium
(B-1) 20.3 g was obtained. <Production of a heat-developable photosensitive material> Silver behenate (50 g), polyvinyl butyral (5 g), xylene (440 ml), n-butanol 28
The mixture was placed in a 0 ml dispersion solvent and dispersed with a homomixer. 47 g of polyvinyl butyral was added to this dispersion and dissolved by stirring to prepare a silver salt polymer dispersion. This dispersion was divided into four equal parts, and a silver bromide-polyvinyl butyral solid shown below was added to each. (1) 4.15 g of the prepared solid (A-1) (2) 4.15 g of the prepared solid (A-1) (3) 4.15 g of the prepared solid (B-1) (4) 4.15 g of solid (B-1) The following components were sequentially added to each of the four silver behenate-containing polymer dispersions containing the two kinds of silver bromide to prepare a photosensitive slurry. 2,2'-methylenebis (6-t-butyl-4-methylphenol) ... 5g Phthalazinone ... 1.5g Behenic acid ... 3.1g Azelaic acid ... 0.25g Homophthalic acid ... 50mg Mercuric bromide ... 6mg Night Blue (Tokyo Chemical) 50 mg 1-carboxymethyl-5-[(3-ethylnaphtho [1,
2-α] oxazolinone-2-ylidene) butylidene-
3-allyl-thiohydantoin ... 4 mg The prepared photosensitive slurries were used as photosensitive slurries (A-2) and (B-2) according to the addition of the solids (A-1) and (B-1), respectively. Two samples (A-2) and (B-2) were obtained. Next, 1.6% of the exemplified compound (3) (CH ₃ CH ₂ COONa) was added to one sample of the photosensitive slurry (A-2) and the photosensitive slurry (B-2).
Add 5 ml of methanol solution and add photosensitive slurry (A-2-1)
And (B-2-1). Further, only 5 ml of methanol was added to the other photosensitive slurries (A-2) and (B-2) to obtain photosensitive slurries (A-2-2) and (B-2-2), respectively. The four types of photosensitive slurries thus prepared were applied to a 100 μm PET film so that the silver amount was 1 g / m ² and dried. Further, the following overcoating protective layer was coated on the coated surface so as to be ² g / m ² when dried, and dried, and the image samples (A-3-1), (A-3-2), (B-3 -
1) and (B-3-2) were created.

<Composition of overcoat protective layer> (A) Polyvinyl alcohol (Nippon Synthetic Chemical Industry Co., Ltd.)
(B) Polyacrylamide latex (20% aqueous solution) (trade name: Santax SP-55, manufactured by Mitsui Toatsu Chemicals, Inc.) 50 g (C) 340 g (A), (B), and (C) of a colloidal solution of anhydrous silicic acid (20% dispersion) (trade name: Snowtex C, manufactured by Nissan Chemical Industries, Ltd.) were mixed, and the mixture was applied to form an overcoat protective layer. The above samples (A-3-1), (A-3-2) and (B-3-1), (B-3-2) were passed through a step tablet having a concentration difference of 0.1 under xenon under green safety light. Exposure was performed with a flash, and thermal development was performed at 120 ° C. for 5 seconds. The irradiation condition was an exposure time of 10 ^-5 seconds, and the light energy amount on the material surface was 0.20 mJ / cm ² . For comparison, the film was similarly exposed to tungsten light and thermally developed. However, the irradiation conditions were such that the exposure time was 1 sec and the amount of light energy on the material surface was 0.70 mJ / cm ² . 1 and 2 show respective characteristic curves. However, there is no correlation between the abscissa energies in FIGS.
As is clear from the results shown in FIGS. 1 and 2, the sample (A-3-1) according to the present invention has the best improvement in high illuminance failure characteristics.

Example 2 In the description of the preparation of the photosensitive silver halide of Example 1,
Methanol solution (II-2) in place of methanol solution (I-2) of sodium hexachloroiridate (IV) hexahydrate
(0.0157 mg / methanol ⁶ ml = 10 ^-6 mol / silver stearate 1 mol) was added to obtain 20.3 g of a silver bromide-polyvinyl butyral solid (D-1) containing iridium. Furthermore, a methanol solution (III-2) of sodium hexachloroiridium (IV) hexahydrate (157 mg / methanol 6 ml = 10 ⁻² mol)
/ 1 mol of silver stearate) to obtain 20.3 g of a silver bromide-polyvinyl butyral solid (E-1) containing iridium.
Next, in the description of Example 1, the photosensitive slurry (A-2),
(D-2) and (E-2) were prepared and the respective compounds (3) (CH
5 mL of a 1.6% methanol solution of ₃ CH ₂ COONa) was added to prepare photosensitive slurries (A-2-1), (D-2-1) and (E-2-1). next,
Samples for imaging (A-3-1), (D-3-1), (E-3
-1) was prepared, and each sample was exposed and heat-developed with a xenon flash under green safety light. FIG. 3 shows a characteristic curve. It is clear from the results of FIG. 3 that the present invention (A-3
(-1) improves the high-illumination failure characteristics, but the low-addition amount of iridium (D-3-1) has insufficient improvement of the high-illumination failure characteristics, and (E-3-1) is remarkable. Fogging occurred.

Example 3 In the photosensitive slurry (A-2-1) described in Examples 1 and 2,
1.6% of added example compound (3) of the present invention (CH ₃ CH ₂ COONa)
Instead of 5 ml of the methanol solution, 5 ml of a 0.5% methanol solution of the exemplified compound (3) was added, and the photosensitive slurry (A-2-3) was added.
Further, 5 ml of a 5% methanol solution of the exemplified compound (3) was added to prepare a photosensitive slurry (A-2-4), and the samples for images (A-3-3) and (A-3) were prepared as described in Example 1. -4) was prepared and exposed and heat-developed by a xenon flash. Table 1 shows the results. In all cases, the samples according to the present invention exhibited excellent image characteristics under high illuminance exposure (xenon flash 10 ^-5 sec).

[0056]

[Table 1]

Example 4 In place of Exemplified Compound (3) added in the photosensitive slurry (A-2-1) described in Examples 1, 2 and 3, Exemplified Compound (7)
5 ml of a 2.3% methanol solution of (CH ₃ (CH ₂ ) ₄ COONa) was added, and the photosensitive slurry (A-2-5) was added to the exemplary compound (25) (CH ₃ (C ₃
5 ml of a 2.34% methanol solution of (H ₂ ) ₃ COOK) was added, and the photosensitive slurry (A-2-6) was further added.
Add 5 ml of a 94% water / methanol solution and add a photosensitive slurry (A
-2-7) was prepared respectively, and the image sample was prepared according to the description in Example 1.
(A-3-5), (A-3-6) and (A-3-7) were prepared and subjected to exposure heat development using a xenon flash. Table 2 shows the results. Table 2
As can be seen from the graph, even when any of the compounds according to the present invention is used, excellent image characteristics are exhibited even under high illuminance exposure.

[0058]

[Table 2]

<Application Example 1> The image sample (A-3-1) prepared in Example 1 was written with a He-Ne laser device (5 mW) at a dot of 5 × 10 ⁻⁷ sec. As a result, a clear image was obtained.

[0060]

According to the present invention, an improved heat-developable photosensitive material having a high image density and high illuminance failure can be provided.
A heat developable photosensitive material having excellent image quality could be provided.

[Brief description of the drawings]

FIG. 1 is a graph showing characteristic curves when a sample of the present invention and a comparative sample are exposed to light by a xenon flash and thermally developed.

FIG. 2 is a graph showing characteristic curves when a sample of the present invention and a comparative sample are exposed to tungsten light and thermally developed.

FIG. 3 is a graph showing characteristic curves when a sample of the present invention and a comparative sample are exposed to light by a xenon flash and thermally developed.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-52236 (JP, A) JP-A-58-72936 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03C 1/498 504 G03C 1/498 501

Claims (2)

(57) [Claims] A heat-developable photosensitive element comprising at least (1) a photosensitive silver halide, (2) an organic silver salt, (3) a reducing agent and (4) a binder on a support in a single layer or a multilayer. In the formed heat-developable photosensitive material, (1) the photosensitive silver halide is a silver ion donor (a) and a halogen ion donor (b)
Is reacted in an organic solvent (c). In the production process, the iridium ion donor (d) is prepared by 90% of the reaction process of the silver ion donor (a) and the halogen ion donor (b). ) ^Is added to the total silver ion donor (a) involved in the reaction in a molar ratio of 5 × 10 ⁻⁷ to 5 × 10 ⁻⁵ , and the iridium ion donor (d) is added in 10% of the remaining reaction process.
Is 5 × 10 5 with respect to the total silver ion donor (a) involved in the reaction.
Iridium ion produced by adding ^-5 to 5 × 10 ^{-3 in} a molar ratio, and wherein the heat-developable photosensitive element has the following general formula (I), (II), (III) or (IV) A photothermographic material comprising at least one compound represented by the formula: Formula (I) R ₁ -COOM _{1 In the} formula, R ₁ represents a linear or branched alkyl group, alkenyl group or aralkyl group, and M ₁ represents sodium or potassium. Formula (II) M ₂ OOC-R ₂ -COOM ₃ Formula (III) M ₂ OOC-COOM _{3 wherein} R ₂ represents a linear or branched alkylene group or alkenylene group, and M ₂ and M ₃ are Represents hydrogen, sodium or potassium (however, M ₂ and M ₃ are not simultaneously hydrogen). General formula (IV) M ₄ —OH In the formula, M ₄ represents sodium or potassium. (1) In the production of a photosensitive silver halide, the silver ion donor (a) is an organic fatty acid silver salt having 5 or more carbon atoms, and the halogen ion donor (b) is an N-halogeno compound. The photothermographic material according to claim 1, wherein the photothermographic material is a combination.