JP2006047461A - Heat developable photographic sensitive material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat developable photographic sensitive material excellent in development humidity dependency and having high image density and image stability. <P>SOLUTION: The heat developable photographic sensitive material has on a support an image forming layer containing a photosensitive silver halide, a non-photosensitive organic silver salt other than silver carboxylates, a reducing agent and a hydrophilic binder and contains a compound represented by a general formula (1) as a nucleation agent and a compound represented by a general formula (2) as a toning agent in the image forming layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photothermographic material.

  Photothermographic materials that are developed with heat and without liquid development have been known to those skilled in the art for many years. In such a material, an image is formed by subjecting the heat-developable photographic material to image-wise exposure with a specific electromagnetic ray (for example, visible light, ultraviolet light, or infrared light), and this image is developed by using heat energy. Used in the recording process. These materials, also known as “dry silver” materials, generally comprise a support coated with the following (a)-(d): (a) a photocatalyst (ie, such as silver halide) A photocatalyst that provides a latent image on the exposed particles upon exposure to light, and that these particles can act as a catalyst for subsequent formation of a silver image in the development process. (B) a non-photosensitive source of reducible silver ions, (c) a reducing composition for the reducible silver ions (usually including a developer), and (d) a hydrophilic or hydrophobic binder . This latent image is then developed by applying thermal energy.

  Photothermographic materials known to those skilled in the art generally contain one or more “toning agents” in order to provide the desired black tone and maximum image density (Dmax). Conventional compounds used for this purpose are phthalimide, N-hydroxyphthalimide, cyclic imide, pyrazolin-5-one, naphthalimide, cobalt complex, N- (aminomethyl) aryldicarboximide, blocked topyrazole. Combinations, isothiuronium derivatives, merocyanine dyes, phthalazine and derivatives thereof (see, for example, Patent Document 1), phthalazinones and phthalazinone derivatives, combinations of phthalazine (or derivatives thereof) with one or more phthalic acid derivatives, quinazolinediones, benzoxazines Or derivatives of naphthoxazine, benzoxazine-2,4-dione, pyrimidine and asym-triazine and tetraazapentalene derivatives.

A specific mercaptan, for example, 2,4-dimercaptopyrimidine, has been described as a toning agent in a photothermographic material (for example, see Patent Document 2). Similarly, 3-mercapto-4,5-diphenyl-1,2,4-triazole compounds are described (for example, see Patent Document 3). 2,5-Dimercapto-1,3,4-thiadiazole, 3-mercapto-1H-1,2,4-triazole and 5-methyl-4-phenyl-3-mercapto-1,2,4-triazole are useful It is described as a toning agent (see, for example, Patent Document 4), whereas 4-phenyl-3-mercapto-1,2,4-triazole and 5-ethyl-4-phenyl-1,2,4 are described. -Triazoles are described as having disadvantages. The use of various mercaptotriazoles in combination with silver benzotriazole has been described (see, for example, Patent Document 5). 4-Phenyl-3-mercapto-1,2,4-triazole is also described in films that require the use of compounds that release a base upon heating, for example, amino and amide substituted mercaptotriazole toning agents. (For example, refer to Patent Documents 6 to 8.)
US Pat. No. 6,146,822 US Pat. No. 4,105,451 (pages 3-4) US Pat. No. 5,149,620 (page 3) US Pat. No. 4,201,582 US Pat. No. 3,832,186 (pages 3-5) Japanese Examined Patent Publication No. 44-026582 JP-A-9-175032 (pages 4-8) US Pat. No. 4,451,561

  An object of the present invention is to provide a heat-developable photographic light-sensitive material which is excellent in development processing humidity dependency and has high image density and image stability.

  The above object of the present invention can be achieved by the following configuration.

(Claim 1)
The support has an image forming layer containing a photosensitive silver halide, a non-photosensitive organic silver salt other than silver carboxylate, a reducing agent, and a hydrophilic binder, and the image forming layer has a nucleating agent. A photothermographic material comprising a compound represented by the following general formula (1) and a compound represented by the following general formula (2) as a color toning agent.

Wherein R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or a substituent, Z represents an electron withdrawing group or a silyl group, R ¹¹ and Z, R ¹² and R ¹³ , and R ¹³ And Z may be bonded to each other to form a cyclic structure.)

(Wherein R ₁ and R ₂ are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 7 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 5 carbon atoms, A substituted or unsubstituted cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted aromatic group having 5 to 6 atoms of carbon, nitrogen, oxygen or sulfur forming an aromatic or non-aromatic ring Alternatively, a non-aromatic heterocyclic group, amino group, amide group, substituted or unsubstituted aryl group having 6 to 10 carbon atoms forming an aromatic ring, or substituted or unsubstituted Y ₁ — (CH ₂ ) _K -group [wherein Y ₁ represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms in the aromatic ring, or a substituted or unsubstituted aromatic or non-substituted group defined for R ₁ above] An aromatic heterocyclic group, and k is Represents a to 3 is.], M is a cation.)
(Claim 2)
2. The photothermographic material according to claim 1, wherein the non-photosensitive organic silver salt other than the silver carboxylate is a silver salt of a hetero organic acid.

  According to the present invention, a photothermographic material having excellent development processing humidity dependency and high image density and image stability can be provided.

  The present invention will be described in more detail.

  The compounds represented by the general formula (1) and the general formula (2) will be described in detail below. First, the electron donating group and the electron withdrawing group in the present invention will be described. In the present invention, the electron donating group is a substituent having a negative Hammett substituent constant σp. Examples of the electron donating group include a hydroxyl group (or a salt thereof), an alkoxy group, An aryloxy group, a heterocyclic oxy group, an amino group, an alkylamino group, an arylamino group, a heterocyclic amino group, a heterocyclic group in which σp takes a negative value, or a phenyl group substituted with these electron donating groups, etc. Can be mentioned. The electron-withdrawing group in the present invention is a substituent having a positive Hammett substituent constant σp. Examples of the electron-withdrawing group include a halogen atom, a cyano group, a nitro group, and an alkenyl group. Alkynyl group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, carbamoyl group, carbonamido group, sulfamoyl group, sulfonamido group, trifluoromethyl group, trichloromethyl group, phosphoryl group, Examples thereof include a carboxy group (or a salt thereof), a sulfo group (or a salt thereof), an imino group, a heterocyclic group in which σp has a positive value, or a phenyl group substituted with these electron-withdrawing groups. Hammett's law was introduced in 1935 by L. L. to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives. P. A rule of thumb proposed by Hammett, which is widely accepted today. Substituent constants obtained by Hammett's rule include a σp value and a σm value, and these values are described in many general books, “Lange's Handbook of Chemistry” (JA Dean). ) "12th sale, 1979 (Mc Graw-Hill) and" Chemical domain special issue ", No. 122, 96-103, 1979 (Nankodo), Chemical Reviews, Vol. 91, 165-195 Page, 1991. The electron-withdrawing group and the electron-donating group in the present invention are defined by the σp value, but are not limited to substituents having known values described in the above-mentioned books.

In the general formula (1), R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or a substituent, Z represents an electron withdrawing group or a silyl group, R ¹¹ and Z, R ¹² and R ¹³ , R ¹³ and Z may be bonded to each other to form a cyclic structure.

Examples of the substituent represented by R ¹¹ , R ¹² and R ¹³ include an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, and a heterocyclic group containing a quaternized nitrogen atom (for example, a pyridinium group). ), A hydroxy group, an alkoxy group (for example, a group containing an ethyleneoxy group or a propyleneoxy group unit repeatedly), an aryloxy group, an acyloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a urethane group, Carboxyl group, imide group, amino group, carbonamide group, sulfonamide group, ureido group, thioureido group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, hydrazino group, quaternary ammonio group, (alkyl, aryl, Or a heterocycle) a thio group, a mercapto group, (al Kill or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, sulfo group, sulfamoyl group, acylsulfamoyl group, (alkyl or aryl) sulfonylureido group, (alkyl or aryl) sulfonylcarbamoyl group, halogen atom, cyano group , Nitro group, phosphoric acid amide group and the like.

  Examples of the electron-withdrawing group represented by Z include a halogen atom, a cyano group, a nitro group, an alkenyl group, an alkynyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, and a carbamoyl group. Group, carbonamido group, sulfamoyl group, sulfonamido group, trifluoromethyl group, trichloromethyl group, phosphoryl group, carboxy group (or salt thereof), sulfo group (or salt thereof), imino group, σp is positive And a heterocyclic group to be taken or a phenyl group substituted with these electron-withdrawing groups.

  Specific compounds of the general formula (1) include the following compounds.

In the general formula (2), R ₁ and R ₂ are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 7 carbon atoms, a substituted or unsubstituted type having 2 to 5 carbon atoms. Alkenyl groups, substituted or unsubstituted cycloalkyl groups having 5 to 7 carbon atoms, substituted or unsubstituted types having 5 to 6 atoms of carbon, nitrogen, oxygen or sulfur forming an aromatic or non-aromatic ring An aromatic or non-aromatic heterocyclic group, amino group, amide group, substituted or unsubstituted aryl group having 6 to 10 carbon atoms forming an aromatic ring, or substituted or unsubstituted Y _1- (CH ₂ ) _k -group [wherein Y ₁ represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms in the aromatic ring, or a substituted or unsubstituted aromatic group defined for R ₁ above. Is an aromatic or non-aromatic heterocyclic group , And k is 1-3. And M is a cation.

Further, R ₁ and R ₂ are bonded to form a ring, and a substituted or unsubstituted saturated or unsaturated aromatic containing a carbon, nitrogen, oxygen or sulfur atom in the ring. Alternatively, a non-aromatic 5- to 7-membered nitrogen-containing heterocycle can be formed. R ₁ or R ₂ can represent a divalent linking group that connects two mercaptotriazole groups, and R ₂ can represent carboxy or a salt thereof. However,
1) R ₁ and R ₂ are not simultaneously hydrogen,
2) When R ₁ is substituted or unsubstituted phenyl or benzyl, R ₂ is not substituted or unsubstituted phenyl or benzyl,
3) When R ₂ is hydrogen, R ₁ is not allenyl, 2,2-diphenylethyl, α-methylbenzyl, or a phenyl group having a cyano or sulfonic acid substituent,
4) When R ₁ is an unsubstituted benzyl or phenyl group, R ₂ is not a substituted 1,2-dihydroxyethyl or 2-hydroxy-2-propyl,
5) When R ₁ is hydrogen, R ₂ is not 3-phenylthiopropyl.

  Specific examples of the compound represented by the general formula (2) of the present invention are shown below.

  Next, the photothermographic material of the present invention will be described.

  The organic silver salt used in the photothermographic material of the present invention is a reducible silver source, a non-photosensitive organic silver salt other than a silver carboxylate, and an organic acid containing a reducible silver ion source and Silver salts of heteroorganic acids, among which nitrogen-containing heterocycles are particularly preferred. An organic or inorganic silver complex in which the ligand has a value of 4.0 to 10.0 as a total stability constant with respect to silver ions is also useful in the present invention. Examples of suitable silver salts include Research Disclosure (hereinafter also simply referred to as RD) No. 17029 and 29963.

  The organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound that forms a complex with silver. As described in Japanese Patent Application Laid-Open No. 9-127643, a normal mixing method, a reverse mixing method, and a simultaneous mixing method are used. A controlled double jet method or the like is preferably used. For example, an alkali metal salt (for example, sodium hydroxide, potassium hydroxide, etc.) is added to an organic acid to prepare an organic acid alkali metal salt soap, and then the soap and silver nitrate are added by a controlled double jet method. To produce organic silver salt crystals. In that case, photosensitive silver halide grains described below (hereinafter, simply referred to as silver halide grains) may be mixed.

  The silver halide grains in the present invention function as an optical sensor. In the present invention, the average particle size is preferably small in order to suppress white turbidity of the photosensitive material after image formation and to obtain good image quality, and the average particle size is 0.1 μm or less, more preferably 0.01 μm to 0. 0.1 μm, particularly preferably 0.02 μm to 0.08 μm. The grain size (particle diameter) as used herein refers to the length of the edge of a silver halide grain when the silver halide grain is a so-called normal crystal of a cube or octahedron. In the case of non-normal crystals, for example, in the case of spherical, rod-like, or tabular grains, it means the diameter of the sphere assuming a sphere equivalent to the volume of the silver halide grains. The silver halide grains are preferably monodispersed. The monodispersion here means that the monodispersity obtained by the following formula is 40% or less. The particles are more preferably 30% or less, particularly preferably 0.1% or more and 20% or less.

Monodispersity = (standard deviation of particle size) / (average value of particle size) × 100
In the present invention, the silver halide grains are preferably monodisperse grains having an average grain size of 0.1 μm or less, and the graininess of the image is improved by setting the grain size within this range.

  The shape of the silver halide grains is not particularly limited, but the ratio occupied by the Miller index [100] plane is preferably high, and this ratio is 50% or more, further 70% or more, particularly 80% or more. It is preferable. The ratio of the Miller index [100] plane is calculated by using the adsorption dependency between the [111] plane and the [100] plane in the adsorption of the sensitizing dye. Tani, J .; Imaging Sci. 29, 165 (1985).

  In addition, another preferable silver halide grain shape in the present invention is a tabular grain. The term “tabular grains” as used herein refers to those having an aspect ratio = r / h of 3 or more when the square root of the projected area is the grain size r μm and the thickness in the vertical direction is h μm. Among them, the aspect ratio is preferably 3 to 50. The particle size of the tabular grains is preferably 0.1 μm or less, and more preferably 0.01 μm to 0.08 μm. These tabular grains can be easily obtained by the method described in US Pat. Nos. 5,264,337, 5,314,798, 5,320,958 and the like. In the present invention, the sharpness of the image can be further improved by using the tabular grains.

  The halogen composition of the silver halide grains is not particularly limited and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide, and silver iodide. The photographic emulsion used in the present invention is P.I. Chifie et Physique Photographic (published by Paul Montel, 1967) by Glafkides. F. Duffin's Photographic Emission Chemistry (published by The Focal Press, 1966), V.C. L. It can be prepared using a method described in Making and Coating Photographic Emulsion (published by The Focal Press, 1964) by Zelikman et al.

  The silver halide used in the present invention preferably contains a metal ion or complex ion belonging to Group 6 to Group 10 of the periodic table of elements in order to improve reciprocity failure characteristics and to adjust the gradation. . As the metal, W, Fe, Co, Ni, Cu, Ru, Rh, Pd, Re, Os, Ir, Pt, and Au are preferable.

  Silver halide grains can remove (desalinate) unnecessary salts by methods known in the art such as noodle method, flocculation method, etc., but in the present invention, desalting is performed even if performed. It does not matter either.

  The silver halide grains in the present invention are preferably chemically sensitized. Preferred chemical sensitization methods include sulfur sensitization methods, selenium sensitization methods, tellurium sensitization methods, noble metal sensitization methods such as gold compounds, platinum, palladium, and iridium compounds, as well known in the art. A sensitization method or the like can be used.

In the present invention, in order to prevent devitrification of the photosensitive material, the total amount of silver halide and organic silver salt is preferably 0.5 g or more and 2.2 g or less per 1 m ² in terms of silver amount. By setting the silver amount within this range, a high-contrast image can be obtained. Further, the ratio of the amount of silver halide to the total amount of silver is 50% or less, preferably 25% or less, more preferably 0.1 to 15% by mass ratio.

  Examples of the reducing agent used in the photothermographic material of the present invention include generally known reducing agents such as phenols, polyphenols having two or more phenol groups, naphthols, bisnaphthols, 2 Polyhydroxybenzenes having two or more hydroxyl groups, Polyhydroxynaphthalenes having two or more hydroxyl groups, Ascorbic acids, 3-pyrazolidones, pyrazolin-5-ones, pyrazolines, phenylenediamines, hydroxylamines, hydroquinone Monoethers, hydroxamic acids, hydrazides, amide oximes, N-hydroxyureas, and the like, and more specifically, for example, U.S. Pat. Nos. 3,615,533, 3,679,426, 3,672,904, 3,751,252, 3, 82,949, 3,801,321, 3,794,488, 3,893,863, 3,887,376, 3,770,448, 3,819,382, 3,773,512, 3,839,048, 3,887,378, 4,009,039, 4,021 , 240, British Patent No. 1,486,148 or Belgian Patent No. 786,086, and Japanese Patent Application Laid-Open Nos. 50-36143, 50-36110, 50-11603, and 50-99719. No. 50-140113, No. 51-51933, No. 51-23721, No. 52-84727, or Japanese Patent Publication No. 51-35851. The present invention is above It can be suitably selected from known reducing agents. As the selection method, the most efficient method is to confirm the suitability of the reducing agent by actually producing a photothermographic material containing a reducing agent and directly evaluating the photographic performance.

  Among the reducing agents described above, preferred reducing agents when using an aliphatic carboxylic acid silver salt as the organic silver salt include polyphenols in which two or more phenol groups are linked by an alkylene group or sulfur, particularly a phenol group. Phenol in which an alkyl group (for example, a methyl group, an ethyl group, a propyl group, a t-butyl group, a cyclohexyl group, or the like) or an acyl group (for example, an acetyl group, a propionyl group, etc.) is substituted on at least one position adjacent to the hydroxy substitution position Polyphenols in which two or more of the groups are linked by an alkylene group or sulfur, such as 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, 1,1-bis (2-hydroxy-3-tert-butyl-5-methylphenyl) methane, 1,1-bis (2-hydroxy-3) 5-di-t-butylphenyl) methane, (2-hydroxy-3-t-butyl-5-methylphenyl)-(2-hydroxy-5-methylphenyl) methane, 6,6′-benzylidene-bis (2 , 4-di-tert-butylphenol), 6,6′-benzylidene-bis (2-tert-butyl-4-methylphenol), 6,6′-benzylidene-bis (2,4-dimethylphenol), 1, 1-bis (2-hydroxy-3,5-dimethylphenyl) -2-methylpropane, 1,1,5,5-tetrakis (2-hydroxy-3,5-dimethylphenyl) -2,4-ethylpentane, US Pat. Nos. 3,5 such as 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane and 2,2-bis (4-hydroxy-3,5-di-t-butylphenyl) propane No. 9,903, No. 4,021,249 or British Patent No. 1,486,148, and JP-A Nos. 51-51933, 50-36110, 50-116023, 52- Polyphenol compounds described in Japanese Patent No. 84727 or Japanese Patent Publication No. 51-35727, bisnaphthols described in US Pat. No. 3,672,904, for example, 2,2′-dihydroxy-1,1′- Binaphthyl, 6,6'-dibromo-2,2'-dihydroxy-1,1'-binaphthyl, 6,6'-dinitro-2,2'-dihydroxy-1,1'-binaphthyl, bis (2-hydroxy- 1-naphthyl) methane, 4,4′-dimethoxy-1,1′-dihydroxy-2,2′-binaphthyl and the like, and further described in US Pat. No. 3,801,321. Sulfonamidophenols or sulfonamidonaphthols such as 4-benzenesulfonamidophenol, 2-benzenesulfonamidophenol, 2,6-dichloro-4-benzenesulfonamidophenol, 4-benzenesulfonamidonaphthol and the like. I can list them.

  The appropriate amount of the reducing agent used in the photothermographic material of the present invention is not uniform depending on the type of organic silver salt used, the type of reducing agent, and other additives, but in general, per mole of organic silver salt. A range of 0.05 to 10 mol, preferably 0.1 to 3 mol is appropriate. Within this range, two or more reducing agents described above may be used in combination. In the present invention, it is preferable to add and apply the reducing agent to the photosensitive layer coating solution immediately before coating in order to reduce the photographic performance fluctuation due to the stagnation time of the photosensitive layer coating solution.

  Binders suitable for the heat-developable photographic light-sensitive material of the present invention are transparent or translucent and generally colorless, natural polymer synthetic resins, polymers and copolymers, and other media for forming films such as gelatin, gum arabic, poly ( Vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), Copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters) , Poly (ureta ), Phenoxy resins, poly (vinylidene chloride), poly (epoxides), poly (carbonates), poly (vinyl acetate), cellulose esters, and polyamides. The binder may be hydrophilic or hydrophobic, but in the present invention, it is preferable to use a hydrophobic transparent binder in order to reduce fogging after heat development. Preferable binders include, for example, polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, polycarbonate, polyacrylic acid, and polyurethane. Among these, polyvinyl butyral, cellulose acetate, cellulose acetate butyrate and polyester are particularly preferably used.

  In order to protect the surface of the photosensitive material or prevent scratches, it is preferable to coat a non-photosensitive layer outside the photosensitive layer. The binder used for these non-photosensitive layers may be the same as or different from the binder used for the photosensitive layer.

In the present invention, the binder amount of the photosensitive layer is preferably 1.5 to 10 g / m ² in order to increase the heat development speed. More preferably 1.7~8g / m ^2. If it is less than 1.5 g / m ² , the density (Dmin) of the unexposed area is significantly increased, which may cause a practical problem.

  In the present invention, it is preferable to include a matting agent on the photosensitive layer side. In order to prevent damage to the image after heat development, the amount of the matting agent disposed on the surface of the photosensitive material is based on the total binder on the photosensitive layer side. It is preferable to contain 0.5-30% by mass ratio. Further, when a non-photosensitive layer is provided on the opposite side of the photosensitive layer with the support sandwiched, it is preferable to contain a matting agent in at least one layer on the non-photosensitive layer side in order to prevent slippage and fingerprint adhesion. The amount of the matting agent is preferably 0.5 to 40% by mass with respect to the total binder of the non-photosensitive layer. The shape of the matting agent may be either a regular shape or an irregular shape, but is preferably a regular shape, particularly a spherical shape.

  The photothermographic material of the present invention has at least one photosensitive layer on a support. Although only the photosensitive layer may be formed on the support, it is preferable to form at least one non-photosensitive layer on the photosensitive layer. Further, in order to control the amount of light passing through the photosensitive layer or the wavelength distribution, a filter dye layer and / or an antihalation dye layer, a so-called backing layer, may be formed on the same side as the photosensitive layer, or A dye or pigment may be directly contained in the photosensitive layer.

  These non-photosensitive layers may contain a sliding agent such as a polysiloxane compound, waxes or liquid paraffin in addition to the binder and matting agent.

  In the heat-developable photographic light-sensitive material of the present invention, various surfactants can be used as coating aids. Among these, fluorine surfactants are particularly preferably used for improving charging characteristics and preventing spotted coating failures.

  The photosensitive layer may be a plurality of layers, or may have a plurality of layer configurations such as a high sensitivity layer / low sensitivity layer or a low sensitivity layer / high sensitivity layer in order to adjust the gradation.

  Examples of suitable toning agents for use in the present invention are disclosed in RD17029.

  The photothermographic material of the present invention includes a mercapto compound and a disulfide compound for suppressing or accelerating development and controlling development intensity, for improving spectral sensitization efficiency or for improving storage stability before and after development processing. Inhibitors such as thione compounds can be contained.

  In the heat-developable photographic material of the present invention, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, a coating aid, and the like may be used. As these additives and the other additives described above, compounds described in RD17029 (June 1978, p.9-15) can be preferably used.

  The various additives described above may be added to any of the photosensitive layer, the non-photosensitive layer, and other forming layers.

  The support used in the present invention is a plastic film (for example, polyethylene terephthalate, polycarbonate, polyimide, nylon, cellulose triacetate, polyethylene naphthalate) in order to obtain a predetermined optical density after development processing and to prevent deformation of the image after development processing. Phthalate).

  Among them, preferable supports include polyethylene terephthalate (hereinafter abbreviated as PET) and a plastic (hereinafter abbreviated as SPS) support including a styrene polymer having a syndiotactic structure. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm.

  A heat-treated plastic support can also be used. Examples of the plastic to be used include the above-described plastics. The heat treatment of the support is a temperature that is 30 ° C. or more higher than the glass transition point of the support, preferably 35 ° C. or more, and more preferably after the support is formed and before the photosensitive layer is applied. It refers to heating at a temperature of 40 ° C. or higher.

  In the present invention, a conductive compound such as a metal oxide and / or a conductive polymer can be included in the constituent layers in order to improve the chargeability. These may be contained in any layer, but are preferably an undercoat layer, a backing layer, a layer between the photosensitive layer and the undercoat.

  Examples of the heat-developable photographic light-sensitive material of the present invention include JP-A-63-159841, JP-A-60-140335, JP-A-63-231437, JP-A-63-259651, JP-A-63-304242, JP-A-63-15245, Sensitizing dyes described in U.S. Pat. Nos. 4,639,414, 4,740,455, 4,741,966, 4,751,175, and 4,835,096 can be used. .

  Specific examples of useful sensitizing dyes used in the present invention include, for example, documents described or cited in Section RD17643IV-A (December 1978, p.23) and Section 18431X (August 1979, p.437). It is described in.

  In the present invention, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, for A) an argon laser light source, JP-A-60-162247, JP-A-2-48653, U.S. Pat. No. 2,161,331, West German Patent 936,071, and JP-A-5-11385. And B) helium-neon laser light sources described in JP-A-50-62425, JP-A-54-18726, JP-A-59-102229, etc. For the merocyanines described in Kaihei 7-287338, C) LED light source and red semiconductor laser, Japanese Patent Publication Nos. 48-42172, 51-9609, 55-39818, JP-A 62-284343, For the thiacarbocyanines described in JP-A-2-105135, D) infrared semiconductor laser light source, JP-A-59-191032, Tricarbocyanines described in JP-A-60-80841, 4-quinoline nuclei described in JP-A-59-192242, JP-A-3-67242, general formula (IIIa) and general formula (IIIb) Dicarbocyanines and the like are advantageously selected.

  These sensitizing dyes may be used alone or in combination. The combination of sensitizing dyes is often used for the purpose of supersensitization. In addition to the sensitizing dye, the silver halide emulsion may contain a dye that itself does not have spectral sensitizing action or a substance that does not substantially absorb visible light and exhibits supersensitization.

  The photothermographic material of the present invention is exposed using a laser light source such as an Ar laser (488 nm), a He—Ne laser (633 nm), a red semiconductor laser (670 nm), an infrared semiconductor laser (780 nm, 830 nm). This is one characteristic, and an infrared semiconductor laser having a wavelength of 700 to 1000 nm is particularly preferable.

  The photothermographic material of the present invention can be provided with a layer containing a dye as an antihalation layer. For Ar laser, He-Ne laser, and red semiconductor laser, it is preferable to add a dye so that absorption is at least 0.3 or more, preferably 0.8 or more at the exposure wavelength in the range of 400 nm to 750 nm. For infrared semiconductor lasers, it is preferable to add a dye in the range of 750 nm to 1500 nm so as to absorb at least 0.3 or more, preferably 0.8 or more at the exposure wavelength. One kind or a combination of several kinds of dyes may be used. The dye can be added to the dye layer close to the support on the same side as the photosensitive layer or to the dye layer on the opposite side of the photosensitive layer.

  The heat-developable photographic material of the present invention may be developed by any method. In the present invention, the temperature of the heat-developable photographic light-sensitive material exposed imagewise is increased, and the heat-development processing is performed at 80 to 250 ° C. It is one of the features, preferably 100 to 140 ° C. The development time is preferably 1 to 180 seconds, more preferably 10 to 90 seconds.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this.

Example 1
(Preparation of undercoated PET support)
Plasma treatment 1 is performed on both surfaces of a 125 μm thick PET film that has been biaxially stretched and heat-fixed under the following conditions, and then the undercoat coating solution a-1 is applied to one surface so that the dry film thickness becomes 0.8 μm. After coating and drying to form an undercoat layer A-1, and coating the opposite surface with the following antistatic coating solution b-1 with a dry film thickness of 0.8 μm. It was made into the undercoat layer B-1 as a conductive layer by making it dry. Next, plasma treatment 2 was performed on the surface of each undercoat layer under the following conditions.

<< Plasma treatment conditions >>
Using a batch type atmospheric pressure plasma processing apparatus (EC-I-H-340, manufactured by EC Chemical Co., Ltd.), the high frequency output is 4.5 kW, the frequency is 5 kHz, the processing time is 5 seconds, and the gas conditions are argon, Plasma treatment 1 and plasma treatment 2 were performed at a volume ratio of nitrogen and hydrogen of 90%, 5%, and 5%, respectively.

<< Undercoat coating liquid a-1 >>
Butyl acrylate (30% by mass), t-butyl acrylate (20% by mass),
Styrene (25% by mass), 2-hydroxyethyl acrylate (25% by mass)
270 g of copolymer latex liquid (solid content 30%)
Hexamethylene-1,6-bis (ethylene urea) 0.8g
Polystyrene fine particles (average particle size 3 μm) 0.05 g
Colloidal silica (average particle size 90μm) 0.1g
Finish to 1 liter with water.
<Undercoat coating liquid b-1>
Tin oxide (average particle size 36nm doped with 0.1% indium)
Amount to be 0.26 g / m ² Butyl acrylate (30% by mass), styrene (20% by mass),
Copolymer latex solution of glycidyl acrylate (40% by mass) (solid content 30%)
270g
Hexamethylene-1,6-bis (ethylene urea) 0.8g
Finish to 1 liter with water.

<Heat treatment of support>
In the undercoating drying step of the obtained undercoated support, the support was heated at 140 ° C. and then gradually cooled. In that case, it conveyed with the tension | tensile_strength of 1 * 10 < ⁵ > Pa.

(Application on the back layer side)
The back layer coating solution 1 and the back protective layer coating solution 1 having the following composition were filtered using a filter having an absolute filtration accuracy of 20 μm before coating, respectively, and then the subbing layer B− obtained by subjecting the prepared support to an antistatic treatment was used. On one surface, simultaneous multilayer coating was performed at a speed of 40 m / min so that the total wet film thickness was 30 μm, and drying was performed at 60 ° C. for 4 minutes.

<Back layer coating solution 1>
Methyl ethyl ketone 22.2 g / m ²
Dye A 22 mg / m ²
Stabilizer B-1 (Sumitomo Chemical Company Sumitizer BPA) 100 mg / m ²
Stabilizer B-2 (Yoshitomi Pharmaceutical Tomissorb 77) 50 mg / m ²
Cellulose acetate propylate (Eastman Chemical CAP504-0.2) 0.5 g / m ²
Cellulose acetate propylate (Eastman Chemical CAP482-20) 1.5 g / m ²
<Back protective layer coating solution 1>
Methyl ethyl ketone 22g / m ²
Surfactant; C ₉ F ₁₇ O (CH ₂ CH ₂ O) ₂₂ C ₉ F ₁₇ 22 mg / m ²
LiO ₃ S (CF ₂ ) ₃ SO ₃ Li 10 mg / m ²
Cellulose acetate propyleneate (Eastman Chemical CAP482-20) 2.5 g / m ²
Matting agent (Fuji Devison Psyroid 74; silica with an average particle size of 7 μm)
12mg / m ²

(Preparation of silver halide grains)
In 900 ml of pure water, 7.5 g of gelatin and 10 mg of potassium bromide were dissolved, adjusted to a temperature of 35 ° C. and a pH of 3.0, and then brominated at a molar ratio of (96/4) with 370 ml of an aqueous solution containing 74 g of silver nitrate. 10 minutes by a controlled double jet method while keeping 370 ml of an aqueous solution containing 0.436 mol of potassium and potassium iodide and 5 × 10 ⁻⁶ mol / liter of (NH ₄ ) ₂ RhCl ₅ (H ₂ O) at pAg 7.7 Added over time. Thereafter, 0.3 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, the pH was adjusted to 5 with NaOH, the average particle size was 0.06 μm, and the variation coefficient of the projected diameter area was 8%. , {100} face ratio 86% silver cubic silver iodobromide grains were obtained. This emulsion was coagulated and precipitated using a gelatin flocculant, desalted and then 0.1 g phenoxyethanol was added to adjust the pH to 5.9 and pAg 7.5.

The emulsion was combined with a gold sensitizer (potassium tetrachloroaurate-KAuCl ₄ ) and a sulfur sensitizer (compound SS-1 described in US Pat. No. 6,296,998) at 60 ° C. for 10 minutes. After sensitization, 1.0 mmol of infrared sensitizing dye 1 was added per mole of silver halide.

<< Preparation of benzotriazole silver dispersion A >>
A reactor equipped with a stirrer was charged with 85 g of lime-processed gelatin, 25 g of phthalate-processed gelatin, and 2 liters of deionized water (solution A). Solution B containing 185 g of benzotriazole, 1405 ml of deionized water, and 680 g of 2.5 M / L sodium hydroxide solution was prepared. The reactor solution was adjusted to pAg 7.25 and pH 8.0 by adding solution B and 2.5 M / L sodium hydroxide solution as needed and maintained at a temperature of 36 ° C. Solution C containing 228.5 g of silver nitrate and 1222 ml of deionized water is added to the reactor at an accelerated flow rate (t is time) with a flow rate = 16 (1 + 0.002 t ² ) ml / min, and solution B is added. The pAg was maintained at 7.25 by adding simultaneously.

  When solution C was used up, the process was terminated, at which point 40 ° C. solution D consisting of 80 g of phthalated gelatin and 700 ml of deionized water was added to the reaction vessel. The resulting solution was stirred in the reaction vessel and the silver salt emulsion was coagulated by adjusting its pH to 2.5 with 2 molar sulfuric acid. The coagulum was washed twice with 5 liters of deionized water and redispersed by adjusting the pH to 6.0 and the pAg to 7.0 with 2.5 M / L sodium hydroxide solution and solution B. . The resulting silver salt dispersion contained fine particles of silver benzotriazole salt.

<< Preparation of silver carboxylate dispersion B >>
40 g of behenic acid, 7.3 g of stearic acid and 500 ml of distilled water are mixed at 90 ° C. for 15 minutes, 187 ml of 1M / L aqueous sodium hydroxide solution is added over 15 minutes with vigorous stirring, and 61 ml of 1M / L aqueous nitric acid solution is added. And cooled to 50 ° C. Next, 124 ml of 1 M / L silver nitrate aqueous solution was added and stirred for 30 minutes. Thereafter, the solid content was filtered by suction filtration, and washed with deionized water and drained until the electric conductivity of the filtrate reached 30 μS / cm. The solid content thus obtained was handled as a wet cake without being dried, and 12 g of polyvinyl alcohol and 150 ml of water were added to the wet cake corresponding to 34.8 g of the dry solid content and mixed well to obtain a slurry. Prepare 840 g of zirconia beads having an average diameter of 0.5 mm, put them in a vessel together with the slurry, and disperse them for 5 hours with a disperser (1/4 G-sand grinder mill: manufactured by IMEX Co., Ltd.). An organic acid silver crystallite dispersion of .5 μm was obtained.

(Preparation of photosensitive layer)
Photosensitive layer A
Silver halide 0.4g / m ²
Benzotriazole silver dispersion A 1.8 g / m ²
Sodium benzotriazole 0.14 g / m ²
3-Methylbenzothiazolium iodide 3-0.07 g / m ²
Succinimide 0.27 g / m ²
1,3-dimethylurea 0.24 g / m ²
Nucleating agent Table 1 listed 0.03 g / m ²
Coloring agent listed in Table 1 0.08 g / m ²
Ascorbic acid 1.1 g / m ²
Lime-processed gelatin 3g / m ²
Photosensitive layer B
Silver halide 0.4g / m ²
Carboxylic acid silver dispersion B 1.8 g / m ²
Sodium benzotriazole 0.14 g / m ²
3-Methylbenzothiazolium iodide 3-0.07 g / m ²
Succinimide 0.27 g / m ²
1,3-dimethylurea 0.24 g / m ²
Nucleating agent Table 1 listed 0.03 g / m ²
Coloring agent listed in Table 1 0.08 g / m ²
Ascorbic acid 1.1 g / m ²
Lime-processed gelatin 3g / m ²
<Evaluation of photographic performance>
(Exposure processing)
Using the obtained photothermographic material, a single channel cylindrical inner surface type laser exposure apparatus equipped with a semiconductor laser having a beam diameter (FWHM of 1/2 of the beam intensity) of 12.56 μm, a laser output of 50 mW, and an output wavelength of 783 nm is used. Then, exposure was performed at a mirror rotation number of 60000 rpm and an exposure time of 1.2 × 10 ⁻⁸ seconds. The overlap coefficient at this time was 0.449, and the laser energy density on the surface of the photothermographic material was 75 μJ / cm ² . Thermal development was performed at 121 ° C. for 20 seconds. Density measurement was performed with a Macbeth TD904 densitometer (visible density). The results are shown in Table 1. Sensitivity was expressed as a logarithm of the exposure amount giving a density of 1.5, expressed as a relative value with S1.5 as a reference and Comparative Sample-1. The higher the value, the higher the sensitivity.

(Evaluation of development processing humidity dependency)
A heat-developable photographic material was prepared at 23 ° C. and 80% humidity for 12 hours and at 23 ° C. and 20% humidity for 12 hours, and was subjected to heat development processing by exposure to 50 μm line width in the same environment.

  The dependency of development processing humidity was evaluated by measuring the difference in line width after each processing. Further, the difference in Dmin (fogging) under each environment was also evaluated.

(Evaluation of raw preservation)
The obtained sample was divided into two parts, and one piece was forcibly deteriorated at 55 ° C. for 3 days, and the other piece was left at room temperature.

  From Table 1, it can be seen that the sample of the present invention is a photothermographic material excellent in development processing humidity dependency and having high image density and image stability.

Claims (2)

The support has an image forming layer containing a photosensitive silver halide, a non-photosensitive organic silver salt other than silver carboxylate, a reducing agent, and a hydrophilic binder, and the image forming layer has a nucleating agent. A photothermographic material comprising a compound represented by the following general formula (1) and a compound represented by the following general formula (2) as a color toning agent.

Wherein R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom or a substituent, Z represents an electron withdrawing group or a silyl group, R ¹¹ and Z, R ¹² and R ¹³ , and R ¹³ And Z may be bonded to each other to form a cyclic structure.)

(Wherein R ₁ and R ₂ are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 7 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 5 carbon atoms, A substituted or unsubstituted cycloalkyl group having 5 to 7 carbon atoms, a substituted or unsubstituted aromatic group having 5 to 6 atoms of carbon, nitrogen, oxygen or sulfur forming an aromatic or non-aromatic ring Alternatively, a non-aromatic heterocyclic group, amino group, amide group, substituted or unsubstituted aryl group having 6 to 10 carbon atoms forming an aromatic ring, or substituted or unsubstituted Y ₁ — (CH ₂ ) _K -group [wherein Y ₁ represents a substituted or unsubstituted aryl group having 6 to 10 carbon atoms in the aromatic ring, or a substituted or unsubstituted aromatic or non-substituted group defined for R ₁ above] An aromatic heterocyclic group, and k is Represents a to 3 is.], M is a cation.) 2. The photothermographic material according to claim 1, wherein the non-photosensitive organic silver salt other than the silver carboxylate is a silver salt of a hetero organic acid.