JP2005338660A - Heat developable photographic sensitive material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat developable photographic sensitive material having high sensitivity, little fog, improved raw preservability and improved humidity dependency in development particularly as a material for printing plate making. <P>SOLUTION: The heat developable photographic sensitive material has on a support an image forming layer containing a non-photosensitive organic silver salt, a photosensitive silver halide and a reducing agent, wherein the image forming layer is formed by coating with a coating liquid containing ≥30 mass% of an organic solvent and a nucleation agent represented by formula (1) is contained in the image forming layer or a layer adjacent to the image forming layer. In the formula, R<SB>11</SB>represents a monovalent substituent; R<SB>12</SB>represents an electron-withdrawing group; one of R<SB>13</SB>and R<SB>14</SB>represents H, the other represents an oxygen anion or a sulfur anion; and R<SB>15</SB>represents an ammonium ion, a phosphonium ion or a sulfonium ion. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat-developable photographic light-sensitive material, and more particularly to a heat-developable photographic light-sensitive material having improved processing humidity dependency and raw storage stability, high sensitivity, and low fog.

In recent years, environmental conservation has become a problem, and it has been required to supply customers with a heat development processing system that eliminates the use of solution processing chemicals and that is simpler and does not impair the environment. Furthermore, in the field of photomechanical technology, it is necessary to form a sharp black image that can be efficiently exposed by a laser scanner or a laser image setter and that has high resolution and sharpness.
The photothermographic material used in the heat development processing system is usually an organic material containing a reducible non-photosensitive silver source (for example, an organic silver salt), a catalytically active photocatalyst (for example, silver halide), and a silver reducing agent. It is contained in a dispersed state in the binder matrix. The light-sensitive material is stable at normal temperature, but when exposed to a high temperature (for example, 80 ° C. or higher) after exposure, silver is oxidized through a redox reaction between a reducible silver source (which functions as an oxidizing agent) and the reducing agent. Is generated. This redox reaction is promoted by the catalytic action of the latent image generated by exposure. The silver produced by the reaction of the reducible silver salt in the exposed areas provides a black image that contrasts with the unexposed areas and forms an image.
These photothermographic materials are required to have high sensitivity and low fog.

Furthermore, in the heat-developable photographic light-sensitive material, the moisture content in the light-sensitive material decreases during the low-humidity season in winter, and the development reaction does not proceed easily. There is a problem that the amount increases, the development reaction easily proceeds, the sensitivity increases, and the character line width increases.
As a conventional technique, a technique (Japanese Patent Laid-Open No. 2001-272742) that uses vinylidene chloride latex for the protective layer to reduce the influence of the character line width under high humidity is known, but has insufficient humidity resistance. At the same time, it was found that the film strength at the time of development becomes weak, so that a roller mark is attached after conveyance by heat development, or when it is bad, it adheres to a roll and cannot be conveyed.
JP 2001-272742 A

  The present invention has been made in view of the above circumstances, and a first object thereof is to provide a photothermographic material having high sensitivity and low fog, particularly for printing plate making. An object of the present invention is to provide a heat-developable photographic light-sensitive material having improved raw storage properties and development processing humidity dependency.

The above purpose is
(1) A coating solution having an image forming layer containing a non-photosensitive organic silver salt, a photosensitive silver halide, and a reducing agent on a support, and the image forming layer contains 30% by mass or more of an organic solvent. A photothermographic material comprising a nucleating agent represented by the following general formula (1) in an image forming layer or a layer provided adjacent to the image forming layer: material.

[Wherein R ₁₁ represents a monovalent substituent, R ₁₂ represents an electron-withdrawing group, one of R ₁₃ and R ₁₄ represents a hydrogen atom, and the other represents an oxygen anion or a sulfur anion, R ₁₅ represents an ammonium ion, a phosphonium ion, or a sulfonium ion. ]
(2) The photothermographic material according to item (1), wherein in the general formula (1), R ₁₁ is an aryl group or an aromatic heterocyclic group.
(3) The photothermographic material according to item (1) or (2), wherein in general formula (1), R ₁₂ is a cyano group.
(4) Acrylic hydrophobicity comprising a microcrystalline wax and / or a paraffin wax formed from a coating solution containing an outermost layer on the image forming layer side and containing 30% by mass or more of water as a coating solvent. The photothermographic material according to any one of (1) to (3) above, which is a resin layer.
Achieved by:

Hereinafter, the present invention will be described in detail.
The photothermographic material of the present invention has an image forming layer containing a non-photosensitive organic silver salt, a photosensitive silver halide and a reducing agent on a support, and the image forming layer contains 30 mass of an organic solvent. % Or more of the coating solution containing the nucleating agent represented by the general formula (1) in the image forming layer or a layer provided adjacent to the image forming layer. .
Hereinafter, description will be made sequentially.
The organic silver salt contained in the photosensitive layer of the photothermographic material of the present invention is a reducible silver source, and the organic silver salt herein includes a silver salt complex. As the organic silver salt, an organic acid having a reducible silver ion or a silver salt of a heteroorganic acid can be used, and in particular, a long chain (10 to 30 carbon atoms, preferably 5 to 25 carbon atoms). Silver salts of aliphatic carboxylic acids and nitrogen-containing heterocyclic carboxylic acids are preferred. Also useful are organic or inorganic silver salt complexes in which the ligand is a ligand having a total stability constant for silver ions of 4.0 to 10.0. Examples of suitable silver salts are described in Research Disclosure (RD) Nos. 17029 and 29963, and include organic acids (eg, gallic acid, oxalic acid, behenic acid, stearic acid, palmitic acid, Silver salt of lauric acid, etc .; Silver salt of carboxyalkylthiourea (eg, 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc.); Aldehyde and hydroxy substitution Polymer reaction products with aromatic carboxylic acids (eg, aldehydes such as formaldehyde, acetaldehyde, butyraldehyde and hydroxy substitution such as salicylic acid, benzylic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid Silver complex of polymer reaction products with acids; thiones (eg Silver salt or silver complex of 3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-2-thione, 3-carboxymethyl-4-methyl-4-thiazoline-2-thione); imidazole, A complex or salt of nitrogen acid and silver selected from pyrazole, urazole, 1,2,4-thiazole, 1H-tetrazole, 3-amino-5-benzylthio-1,2,4-triazole, benzotriazole; saccharin, Silver salts such as 5-chlorosalicylaldoxime; silver salts of mercaptides and the like. Preferred silver sources are silver behenate, silver arachidate or silver stearate.

The organic silver salt can be obtained by mixing a water-soluble silver compound and a compound that forms a salt or complex with silver. For mixing, a normal mixing method, a back mixing method, a simultaneous mixing method, Japanese Patent Laid-Open No. 9-127643 The controlled double jet method described in the publication is preferably used. The organic silver salt particles used in the present invention include, for example, an organic acid alkali metal salt soap (for example, sodium behenate, sodium arachidate, etc.) by adding an alkali metal salt (for example, sodium hydroxide, potassium hydroxide, etc.) to an organic acid. ), And then using a controlled double jet method, the metal salt soap and silver nitrate can be mixed to produce an organic silver salt crystal. Silver halide grains may be mixed during production.
The photosensitive silver halide grains contained in the image forming layer of the photothermographic material of the present invention function as an optical sensor. The silver halide grains used in the present invention preferably have a smaller average grain size in order to keep the white turbidity after image formation low and to obtain good image quality, and the average grain size is preferably 0.3 μm or less. Preferably it is the range of 0.01-0.1 micrometer.
In the present invention, the silver halide grains are produced simultaneously with the preparation of the organic silver salt, or are fused to the organic silver salt by mixing silver halide grains during the preparation of the organic silver salt. It is preferable that silver halide grains be present in the state, and the silver halide grains be so-called in situ silver of fine grains.

The average grain size of the silver halide grains can be determined by photographing the silver halide grains with an electron microscope of 50000 times, measuring the grain size of 100 grains, and averaging.
Here, the grain size means the length of the edge of the 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 a sphere having a volume equivalent to the volume of silver halide grains.
The silver halide grains are preferably monodispersed grains. The monodispersion here means that the monodispersity obtained by the following formula is 40% or less. Furthermore, it is preferable that the particles have a monodispersity of 30% or less, particularly preferably particles having a monodispersity of 0.1 to 20%.
Monodispersity (%) = [(standard deviation of particle size distribution) / (average value of particle size)] × 100
The silver halide grains used in the present invention are more preferably monodisperse grains having an average grain size of 0.01 to 0.03 μm, and the graininess of the image is improved by making 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 preferably 50% or more, more preferably 70% or more, and particularly preferably 80% or more. . The ratio of the Miller index (100) plane is a T.K. based on the adsorption dependency between the (111) plane and the (100) plane in the adsorption of the sensitizing dye. Tani; Imaging Sci. 29, 165 (1985).

The silver halide grains are preferably tabular grains. The term “tabular grain” as used herein refers to those having an aspect ratio expressed by r / h of 3 or more when the grain size expressed by the square root of the projected area of the grain is r μm and the thickness in the vertical direction is h μm. Among them, particles having an aspect ratio of 3 or more and 50 or less are preferable. Moreover, it is preferable that a particle size is 0.03 micrometer or less, and also exists in the range of 0.01-0.03 micrometer. The method for producing these silver halide grains is described in US Pat. Nos. 5,264,337, 5,314,798, 5,320,958, etc. The desired tabular grains can be obtained. When these tabular grains are used in the present invention, the sharpness of the image is further improved.
The 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.
Silver halide photographic emulsions are described in 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 grains used in the present invention preferably contain metal ions or complex ions belonging to Groups 6 to 10 of the Periodic Table of Elements in order to improve the illuminance failure and to adjust the improvements. As the metal, W, Fe, Co, Ni, Cu, Ru, Rh, Pd, Re, Os, Ir, Pt, and Au are preferable.

The silver halide grains can be used after being washed with water and desalted by a method known in the art such as a noodle method or a flocculation method, but can also be used without desalting.
The silver halide grains used in the present invention are preferably chemically sensitized. Chemical sensitization methods include sulfur sensitization, selenium sensitization, tellurium sensitization, noble metal sensitization and reduction sensitization using gold compounds, platinum, palladium, iridium compounds, etc., which are well known in the art. Can be used.
In the present invention, in order to prevent devitrification of the photothermographic material, the total amount of silver halide grains and organic silver salt is preferably 0.3 to 2.2 g per 1 m ² in terms of silver amount. It is more preferable to set it as 0.5-1.5g. In addition, a hard image can be obtained by setting this range.
Further, the amount of silver halide relative to the total amount of silver is preferably 50% or less, more preferably 25% or less, and particularly preferably 0.1 to 15% in terms of mass ratio.
The silver halide grains in the present invention have a maximum light absorption at 350 to 450 μm, and a sensitizing dye is not particularly required, but may be used as necessary.

The reducing agent contained in the photosensitive layer generates silver from a silver source that can be reduced by an oxidation-reduction reaction.
Examples of suitable reducing agents include U.S. Pat. Nos. 3,770,448, 3,773,512, 3,593,863, and RD 17029 and The following are mentioned.
Aminohydroxycycloalkenone compounds (e.g. 2-hydroxy-3-piperidino-2-cyclohexenone); aminoreductones esters (e.g. piperidinohexose reductone monoacetate) as precursors of reducing agents; N- Hydroxyurea derivatives (eg Np-methylphenyl-N-hydroxyurea); aldehyde or ketone hydrazones (eg anthracene aldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (Eg, hydroquinone, t-butyl-hydroquinone, isopropylhydroquinone, (2,5-dihydroxy-phenyl) methylsulfone); sulfhydroxamic acids (eg, benzenesulfuroxy) Mucinic acid); sulfonamidoanilines (eg, 4- (N-methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (eg, 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone) Tetrahydroquinoxalines (eg, 1,2,3,4-tetrahydroquinoxaline); amide oximes; azines; combinations of aliphatic carboxylic acid arylhydrazides and ascorbic acid; combinations of polyhydroxybenzene and hydroxylamine; And / or hydrazine; hydroxanoic acids; combinations of azines and sulfonamidophenols; α-cyanophenylacetic acid derivatives; combinations of bis-β-naphthol and 1,3-dihydroxybenzene derivatives; 5-pyrazolones; Enol reducing agent; 2-phenylindane-1,3-dione, etc .; Chroman; 1,4-dihydropyridines (for example, 2,6-dimethoxy-3,5-dicarboethoxy-1,4-dihydropyridine); Bisphenols (For example, bis (2-hydroxy-3-tert-butyl-5-methylphenyl) methane, bis (6-hydroxy-m-tri) mesitol, 2,2-bis (4-hydroxy-3-methyl Phenyl) propane, 4,4-ethylidene-bis (2-tert-butyl-6-methylphenol)), UV-sensitive ascorbic acid derivatives; hindered phenols; 3-pyrazolidones.
Of these, particularly preferred reducing agents are hindered phenols.
The amount of the reducing agent used is preferably 1 × 10 ⁻² to 10 mol, and particularly preferably 1 × 10 ^{−2 to} 1.5 mol, per mol of silver.

  The nucleating agent contained in the image forming layer or the layer provided adjacent to the image forming layer of the photothermographic material of the present invention is a compound represented by the general formula (1).

[Wherein R ₁₁ represents a monovalent substituent, R ₁₂ represents an electron-withdrawing group, one of R ₁₃ and R ₁₄ represents a hydrogen atom, and the other represents an oxygen anion or a sulfur anion, R ₁₅ represents an ammonium ion, a phosphonium ion, or a sulfonium ion. ]
The compound represented by the general formula (1) will be described in detail.
The monovalent substituent represented by R ₁₁ may be any, for example, an alkyl group (for example, methyl group, ethyl group, butyl group, amyl group, octyl group, nonyl group, decyl group), alkenyl group (for example, Vinyl group), aryl group (for example, phenyl group, naphthyl group), alkoxycarbonyl group (for example, ethoxycarbonyl group), aminocarbonyl group (for example, phenylaminocarbonyl group), aromatic heterocycle which may be condensed with benzene ring. Ring group (for example, thienyl group, benzo [b] thienyl group, benzo [c] thienyl group, furyl group, benzofuryl group, isobenzofuranyl group, pyrrolyl group, thiazolyl group, pyrazinyl group, pyridyl group, pyrazinyl group), etc. Is mentioned. These monovalent substituents may further have a substituent, such as an alkyl group, an alkenyl group, an alkynyl group, an aryl group (for example, a phenyl group, a naphthyl group, an anthranyl group, etc.). ), Heterocyclic group (thiazolidyl group, pyrrolyl group, imidazolyl group, oxazolyl group, etc.), heteroaryl group (pyridyl group, pyrazyl group, imidazolyl group, thiazolyl group, thienyl group, furyl group, etc.), quaternized nitrogen Heterocyclic groups containing atoms (imidazolium groups, pyridinium groups, etc.), hydroxyl groups, alkoxy groups (including groups containing repeating ethyleneoxy or propyleneoxy units), aryloxy groups, acyloxy groups, acyl groups, alkoxycarbonyl groups, Aryloxycarbonyl group, carbamoyl group, urethane group, carbo Sil 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 complex Ring thio group, mercapto group, alkyl or arylsulfonyl group, alkyl or arylsulfinyl group, sulfo group, sulfamoyl group, acylsulfamoyl group, alkyl or arylsulfonylureido group, alkyl or arylsulfonylcarbamoyl group, halogen atom, cyano group , A nitro group, a phosphoramide group, and the like.
Of these monovalent substituents, an aryl group and an aromatic heterocyclic group are preferable.

The electron withdrawing group represented by R ₁₂ means a substituent having a positive Hammett's 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 rule is a method that was introduced in 1935 to discuss quantitatively 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)," Chemical domain special issue "No. 122, 96-103, 1979 (Nankodo)," Chemical Reviews "Vol. 91, 165-195 Page, 1991.
The electron-withdrawing group in the present invention is defined by the σp value, and is not limited to only a substituent having a known value described in the above-mentioned book.
Of these, a particularly preferred group is a cyano group.
R ₁₁ and R ₁₂ may combine to form a ring together with the carbon atom.
One of R ₁₃ and R ₁₄ represents a hydrogen atom, and the other represents an oxygen anion or a sulfur anion. Preferably, one of R ₁₃ and R ₁₄ is a hydrogen atom, and the other is an oxygen anion. It is a certain compound.
Hereinafter, although the specific example of a compound represented by General formula (1) is given, this invention is not limited to these. In the compounds listed below, when keto-enol tautomers or cis-trans geometric isomers are present, both are meant.

These compounds represented by the general formula (1) can be easily synthesized by known methods.
The nucleating agent represented by the general formula (1) is added to the image forming layer and / or a layer provided adjacent to the image forming layer. The optimum amount varies depending on the halogen composition, the degree of chemical sensitization, the type of inhibitor, etc., and is not uniform, but is generally about 10 ⁻⁶ to 10 ⁻¹ mol, especially 10 ⁻⁵ to 10 ⁻ per mol of silver halide. A range of ² moles is preferred.
The nucleating agent represented by the general formula (1) of the present invention is a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohols, etc.), ketones (acetone, methyl ethyl ketone, etc.), dimethylformamide. It can be dissolved in dimethyl sulfoxide, methyl cellosolve, etc. and added to the desired constituent layer. Further, it can be incorporated by emulsifying and dispersing by a well-known emulsifying dispersion method. For example, it is dissolved using an auxiliary solvent such as ethyl acetate or cyclohexanone, and mechanically emulsified and dispersed in a high boiling point organic solvent such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate, diethyl phthalate, etc. It can be made and added to the desired constituent layer. Further, a method known as a solid dispersion method, for example, a nucleating agent powder represented by the general formula (1) is dispersed in water-based fine particles using a dispersing means such as a ball mill, a colloid mill, or an ultrasonic dispersing machine. Can be obtained and added to the desired constituent layers.

  In addition to the image forming layer which is a photosensitive layer, the photothermographic material of the present invention may be provided with a non-photosensitive layer which is usually provided in the photothermographic material, such as an intermediate layer, a backing layer and a barrier layer. Two or more photosensitive layers may be provided.

In the present invention, an acrylic hydrophobic resin layer containing a microcrystalline wax and / or a paraffin wax formed from a coating solution containing 30% by mass or more of water as a coating solvent is provided on the image forming layer side as the outermost layer. It is preferable.
Commercially available microcrystalline wax and paraffin wax can be used as the microcrystalline wax and paraffin wax.
As the acrylic hydrophobic resin, poly (methyl acrylic acid), poly (ethyl acrylic acid), poly (methyl methacrylic acid), poly (ethyl methacrylic acid), and copoly (styrene-acrylonitrile) can be used.
Each of these layers can be formed by preparing a coating solution and coating it. As a method for preparing and applying the coating solution, a general method can be used.
A binder is used for forming the photosensitive layer, the non-photosensitive layer, and the like of the photothermographic material of the present invention. These binders may be either hydrophilic binders (binders or latexes that dissolve in water) or hydrophobic binders (binders that dissolve in organic solvents), but the binders of each layer are binders that dissolve in the same solvent system. Is preferred. For example, the binder of each layer such as the photosensitive layer, the intermediate layer, and the protective layer is preferably a hydrophobic binder or a hydrophilic binder.
A transparent or translucent binder is used for each layer, and generally a colorless one is used. Natural polymers, synthetic monopolymers and copolymers, and other media that form a film are used. Specific examples of the binder used include water-soluble substances such as: gelatin, gum arabic, poly (vinyl alcohol), poly (vinyl pyrrolidone), poly (acrylic acid), poly (methacrylic acid), hydroxyethyl cellulose, casein, and starch. Binder, cellulose acetate, cellulose acetate butyrate, poly (vinyl chloride), poly (methyl methacrylic acid), copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal ) (For example, poly (vinyl formal), poly (vinyl butyral)), poly (ester), poly (urethane), phenoxy resin, poly (vinylidene chloride), poly (epoxide), poly (carbonate) , Poly (Vini Acetate), cellulose esters include hydrophobic binder such as poly (amide). Among them, preferred are polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, polycarbonate, polyacrylic acid, polyurethane, etc., and particularly binders such as polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, etc. Examples thereof include latex obtained by polymerizing a resin monomer in water using an emulsion polymerization method or a suspension polymerization method.

As the main solvent for dissolving the hydrophobic binder, for example, alcohols (methanol, ethanol, propanol, etc.), ketones (acetone, methyl ethyl ketone, etc.), dimethylformamide, dimethyl sulfoxide, methyl cellosolve, etc. are preferably used.
The binder used for forming the photosensitive layer preferably has a Tg of 40 ° C. or higher. More preferably, it is 40-120 degreeC, and also 40-100 degreeC is more preferable. Especially preferably, it is 40-80 degreeC. When the temperature is lower than 40 ° C., the developability is increased, and the sensitivity increase under high humidity (increase in the character line width) is not preferable. On the other hand, when the temperature is higher than 120 ° C., the temperature is almost the same as the heat development temperature, so that heat transfer is delayed and developability is lowered, which is not preferable.
In order to control the amount of light reaching the photosensitive layer and the wavelength distribution, a filter dye layer may be formed on the same side as the photosensitive layer, and an auxiliary layer such as an antihalation dye layer may be formed on the opposite side of the photosensitive layer. Further, the photosensitive layer may contain a dye or a pigment. These auxiliary layers may contain a matting agent, a polysiloxane compound, a wax, and a slipping agent such as liquid paraffin in addition to the binder.
In the formation of each layer of the photothermographic material of the present invention, various surfactants can be used as coating aids. Among them, a fluorosurfactant improves charging characteristics or causes spotted coating failure. It is preferably used to prevent this.
In the heat-developable photographic light-sensitive material of the present invention, the photosensitive layer may be a plurality of layers, and in order to adjust the gradation, a plurality of layers such as a high sensitivity layer / low sensitivity layer or a low sensitivity layer / high sensitivity layer are formed. can do.
Examples of suitable color toning agents (dyes, pigments, etc.) used in the heat-developable photographic light-sensitive material of the present invention are disclosed in RD No. 17029.
An antifoggant can be used in the heat-developable photographic light-sensitive material of the present invention, and the antifoggant may be added to any of the photosensitive layer, the intermediate layer, the protective layer and other forming layers.
In the photothermographic material of the present invention, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, a coating aid and the like may be used. As these additives and the other additives described above, compounds described in RD No. 17029 (June 1978, p. 9-15) can be preferably used.

As the support for the photothermographic material of the present invention, a low heat shrinkable support is preferably used from the viewpoint of dimensional stability.
The preferred low heat-shrinkable support used in the present invention has a dimensional change rate at 120 ° C. and 60 seconds corresponding to the temperature of heat development in order to suppress dimensional change of the heat-developable photographic photosensitive material due to heating during heat development. Absolute values are in the range of 0.001 to 0.06% in both MD (longitudinal) and TD (width) directions, preferably in the range of 0.001 to 0.04%, and particularly preferably in the range of 0.001 to 0.02%. Those in the range are selected.
The rate of dimensional change is determined by placing the support under conditions of 23 ° C. and 55% RH, marking a certain length in the MD and TD directions of the support, heating to 120 ° C. for 60 seconds, and again. The humidity is adjusted for 3 hours under conditions of 23 ° C. and 55% RH, the length in each direction is measured, and the change in the length is obtained.
The dimensional change rate is a value obtained by dividing the value obtained by subtracting the size after heating from the size before heating by the size before heating, expressed as a percentage, and the dimensional change rate is expressed as a positive value or a negative value.
The film used as the base material of the support is preferably made of a thermoplastic resin, and a particularly preferable thermoplastic resin is a polyester resin in view of mechanical strength, thermal dimensional stability, and transparency. More preferred are aromatic polyester resins, and specific examples include polyethylene terephthalate and polyethylene naphthalate. The thickness of these films is preferably from 50 μm to 500 μm, more preferably from 75 μm to 300 μm, and even more preferably from 90 μm to 200 μm.
By appropriately selecting the heat treatment conditions, the dimensional change rate of the support can be set to the dimensional change rate described above.

In order to set the dimensional change rate of the support to the dimensional change rate described above, the heat treatment is carried as much as possible in order to reduce the dimensional change during the subsequent heat treatment (thermal development) without hindering the progress of heat shrinkage. It is desirable to lower the tension and lengthen the heat treatment time. When the support is a polyester film, the treatment temperature is preferably a temperature range of (Tg + 50) ° C. to (Tg + 150) ° C. of the polyester, and the transport tension is 9.8 kPa to 2 MPa, more preferably 9.8 kPa to 980 kPa, and still more preferably It is 9.8 kPa-490 kPa, and the treatment time is preferably 30 seconds to 10 minutes, more preferably 30 seconds to 5 minutes. By using the above temperature range, conveyance tension range, and processing time, the flatness of the support does not deteriorate due to a partial difference in thermal shrinkage of the support during heat treatment, and fine scratches due to friction with the transfer roll, etc. Etc. can also be suppressed.
Moreover, it is also a preferable aspect that the longitudinal relaxation treatment and / or the lateral relaxation treatment is performed after the heat setting before the heat treatment. The heat treatment is required at least once in order to obtain a desired rate of dimensional change, and may be performed twice or more as necessary. Furthermore, after the heat-treated polyester film is cooled from a temperature near Tg to room temperature, it is wound up. It is preferable to cool at a rate of
The heat treatment time can be controlled by changing the film conveyance speed or changing the length of the heat treatment zone. If the heat treatment time is too short, the thermal dimensional stability is lowered. Further, if it is 60 minutes or longer, the flatness and transparency of the support are deteriorated, which is not preferable as a support for a heat-developable photographic material. The tension in the heat treatment can be adjusted by adjusting the torque of the winding roll and / or the feeding roll. It can also be achieved by installing a dancer roll in the process and adjusting the load applied to it. When changing the tension during the heat treatment and / or cooling after the heat treatment, a desired tension state may be set by installing dancer rolls before and after these processes and / or in the processes and adjusting their loads. . In addition, it is possible to effectively change the conveyance tension by vibration by reducing the span between the heat treatment rolls.

It is preferable to provide an undercoat layer on the support. When the undercoat layer is provided, it is preferable to use acrylic resin, polyester resin, acrylic-modified polyester resin, polyurethane resin, vinylidene chloride resin, polyvinyl alcohol resin, cellulose ester resin, styrene resin, gelatin and the like. In addition, if necessary, triazine-based, epoxy-based, melamine-based, isocyanate-containing isocyanates including blocked isocyanate, aziridine-based, oxazaline-based crosslinking agents, colloidal silica and other inorganic particles, surfactants, thickeners, dyes, Preservatives and the like may be added.
It is also preferable to provide an antistatic layer. The antistatic layer is composed of an antistatic agent and a binder.
A metal oxide is preferably used as the antistatic agent. As the metal oxide, for example, ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₂ , V ₂ O ₅ , or a composite oxide thereof is preferable. In particular, SnO ₂ (tin oxide) is preferable in terms of miscibility with the binder, conductivity, transparency, and the like. A different element can be added to the metal oxide, and Sb, Nb, a halogen element, or the like can be added to SnO ₂ . The amount of these different elements added is preferably in the range of 0.01 to 25 mol%, particularly preferably in the range of 0.1 to 15 mol%. Tin oxide is preferably in the form of an amorphous sol or crystalline particles. When performing aqueous coating, it is preferable to use an amorphous sol, and when performing solvent-based coating, it is preferable to use one in the form of crystalline particles. In particular, from the viewpoint of workability in the environment, an aqueous coating form using an amorphous sol is preferable.
The method for producing the amorphous SnO ₂ sol may be any method such as a method in which SnO ₂ fine particles are dispersed in a suitable solvent, a method in which a Sn compound soluble in the solvent is decomposed in a solvent, and the like. The crystalline particles are described in detail in JP-A-56-143430 and JP-A-60-258541.

The conductive metal oxide fine particles can be produced by firstly producing metal oxide fine particles by firing and heat-treating them in the presence of different atoms in order to improve conductivity, and second, producing metal by firing. A production method in which different atoms coexist when producing oxide fine particles, a third method, or a method of introducing oxygen defects by lowering the oxygen concentration during firing is used.
The average primary particle diameter of the conductive metal oxide fine particles is preferably 0.001 to 0.5 μm, particularly preferably 0.001 to 0.2 μm. The solid distribution amount of the conductive metal oxide fine particles is preferably 0.05 to ² g, more preferably 0.1 to 1 g, per 1 m ² . The volume fraction of the metal oxide in the antistatic layer in the present invention is 8 to 40 vol%, preferably 10 to 35 vol%. Although the said range changes with the color, form, composition, etc. of metal oxide fine particles, the said range is the most preferable from the point of transparency and electroconductivity.
A binder can be used to form the antistatic layer, but it is preferable to use the same resin as the undercoat layer as the binder, particularly from the viewpoint of dispersibility and conductivity of the metal oxide, Acrylic modified polyester, acrylic resin and cellulose ester are preferred.
The film thickness of the antistatic layer is preferably 0.30 to 0.70 μm from the viewpoint of transparency and coating unevenness (interference unevenness). More preferably, it is 0.35-0.55 micrometer. If it is less than 0.30 μm, the desired high-temperature conductivity is ensured and the scratch property when a BC layer is provided is undesirably deteriorated. On the other hand, when the thickness exceeds 0.70 μm, the unevenness of interference is strong, the commercial value is deteriorated, and the transparency is deteriorated to be unpractical.
As a coating formation method for the photosensitive layer, the undercoat layer, the antistatic layer and the like, any known coating method can be applied. For example, kiss coat method, reverse coat method, die coat method, reverse kiss coat method, offset gravure coat method, Mayer bar coat method, roll brush method, spray coat method, air knife coat method, impregnation method, curtain coat method, etc. Or it is good to apply in combination.

  The heat-developable photographic light-sensitive material of the present invention has improved processing humidity dependency and is excellent in raw storability.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.
Example 1
1. Preparation of undercoated PET (polyethylene terephthalate) support 1 Plasma treatment was performed on both sides of a 125 μm thick PET film that had been biaxially stretched and heat-set under the following treatment conditions, and then the following The undercoating liquid a-1 is applied to a dry film thickness of 0.8 μm and dried to form an undercoat layer (A-1), and the following undercoating liquid b-1 is applied to the other surface. An undercoat layer (B-1) having antistatic properties was formed by coating the film so as to have a dry film thickness of 0.8 μm and then drying.
<Undercoat coating liquid a-1>
Copolymer latex liquid of butyl acrylate (30% by mass), t-butyl acrylate (20% by mass), styrene (25% by mass), 2-hydroxyethyl acrylate (25% by mass) (solid content 30%) 270 g
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 <Undercoating liquid b-1>
Tin oxide (average particle size 36nm doped with 0.1% indium)
Amount to be 0.26 g / m ² Copolymer latex liquid of butyl acrylate (30% by mass), styrene (20% by mass), glycidyl acrylate (40% by mass) (solid content 30%) 270 g
Hexamethylene-1,6-bis (ethylene urea) 0.8g
Finish to 1 liter with water

Next, the surface of each undercoat layer was subjected to plasma treatment under the following treatment conditions to obtain a support 1.
(Plasma treatment)
Using a batch type atmospheric pressure plasma processing apparatus (AP-I-H-340, manufactured by EC Chemical Co., Ltd.), high-frequency output under the gas conditions of 90 vol% argon, 5 vol% nitrogen, and 5 vol% hydrogen The measurement was performed under the conditions of 4.5 kW, frequency 5 kHz, and processing time 5 seconds.
In the undercoating drying step, 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.

2. Coating on the back layer surface side The back layer coating solution 1 and the back protective layer coating solution 1 having the following composition are filtered using a filter having an absolute filtration accuracy of 20 μm before coating, respectively, and the support has an antistatic property on the support. On (B-1), simultaneous multilayer coating was performed at a rate 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
Infrared dye-A 22 mg / m ²
Stabilizer B-1 100 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

〈バック保護層塗布液１〉
メチルエチルケトン ２２ｇ／ｍ²
界面活性剤；Ｃ₉Ｆ₁₇Ｏ（ＣＨ₂ＣＨ₂Ｏ）₂₂Ｃ₉Ｆ₁₇ ２２ｍｇ／ｍ²
ＬｉＯ₃Ｓ（ＣＦ₂）₃ＳＯ₃Ｌｉ １０ｍｇ／ｍ²
セルロースアセテートプロピレート（Ｅａｓｔｍａｎ Ｃｈｅｍｉｃａｌ社 ＣＡＰ４８２−２０） ２．５ｇ／ｍ²
マット剤（富士デビソン社サイロイド７４；平均粒径７μｍのシリカ）
１２ｍｇ／ｍ²

<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 photosensitive silver halide emulsion A >>
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. An aqueous solution containing 5 × 10 ⁻⁶ mol / liter of potassium, potassium iodide and iridium chloride was added over 10 minutes by the controlled double jet method while maintaining pAg 7.7. 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 Silver halide grains composed of cubic silver iodobromide with 8% and a (100) plane ratio of 86% were obtained. This emulsion was coagulated and precipitated using a gelatin flocculant, desalted, and 0.1 g phenoxyethanol was added to adjust the pH to 5.9 and pAg 7.5 to obtain photosensitive silver halide emulsion A.
<< Preparation of Aliphatic Carboxylic Acid Silver Salt A >>
130.8 g of behenic acid, 67.7 g of arachidic acid, and 43.6 g of stearic acid were dissolved in 4720 ml of pure water at 80 ° C. Next, 540.2 ml of a 1.5 M sodium hydroxide aqueous solution was added, and 6.9 ml of concentrated nitric acid was added, followed by cooling to 55 ° C. to obtain a fatty acid sodium solution. While maintaining the temperature of the fatty acid sodium solution at 55 ° C., 45.3 g of the above photosensitive silver halide emulsion A and 450 ml of pure water were added and stirred for 5 minutes.
Next, 702.6 ml of 1M silver nitrate solution was added over 2 minutes and stirred for 10 minutes to obtain an aliphatic carboxylic acid silver salt dispersion. Transfer the resulting aliphatic carboxylic acid silver salt dispersion to a water-washing vessel, add deionized water, stir, and then stand to float and separate the aliphatic carboxylic acid silver salt dispersion to remove the lower water-soluble salts did. Thereafter, washing with deionized water and drainage were repeated until the electrical conductivity of the drainage reached 50 μS / cm, and centrifugal dehydration was performed to obtain a cake-like aliphatic carboxylic acid silver salt. The obtained cake-like aliphatic carboxylic acid silver salt was subjected to a nitrogen gas atmosphere and a dryer inlet hot air temperature (40 ° C.) operating conditions using an airflow dryer flash jet dryer (manufactured by Seishin Enterprise Co., Ltd.). It dried until the moisture content became 0.1%, and powdered aliphatic carboxylic acid silver salt A was obtained. An infrared moisture meter was used to measure the moisture content of the aliphatic carboxylic acid silver salt A.
<< Preparation of Preliminary Dispersion A >>
Dissolve 14.57 g of polyvinyl butyral resin (P-9) in 1457 g of methyl ethyl ketone, and gradually add 500 g of powdered aliphatic carboxylic acid silver salt A while stirring with a dissolver DISPERMATCA-40M manufactured by VMA-GETZMANN. Preliminary dispersion A was prepared by mixing.
<< Preparation of photosensitive emulsion dispersion A >>
Media type disperser DISPERMAT SL- filled with 80% of the internal volume of 0.5 mm diameter zirconia beads (Torayserum manufactured by Toray) so that the residence time in the mill is 1.5 minutes using a pump. Photosensitive emulsion dispersion A was prepared by supplying to C12EX type (VMA-GETZMANN) and dispersing at a mill peripheral speed of 8 m / s.

A photosensitive layer, an intermediate layer, and a protective layer having the following composition were formed on the opposite side of the back layer of the support obtained above by multilayer coating to prepare heat-developable photographic photosensitive material samples 1 to 8.
<< Photosensitive layer composition >>
Photosensitive emulsion dispersion A 1.4 g (in silver) / m ²
Antifoggant 1 1.5 × 10 ⁻⁴ mol / m ²
Calcium bromide 1.8 × 10 ⁻⁴ mol / m ²
Stabilizer liquid 1 0.3 g / m ²
Infrared sensitizing dye liquid A 2.7 g / m ²
Tetrachlorophthalic acid 7.9 × 10 ⁻⁴ mol / m ²
1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane 4.8 × 10 ⁻³ mol / m ²
Infrared dye B 3 × 10 ⁻⁵ mol / m ²
4-methylphthalic acid 5 × 10 ⁻⁴ mol / m ²
Compound (nucleating agent) represented by general formula (1) (described in Table 1) 0.5 × 10 ⁻³ mol / m ²
2-Tribromomethylsulfonylpyridine 6.0 × 10 −4 mol / m ²
o-phthalic acid 4.0 × 10 ⁻⁴ mol / m ²
As the solvent, methyl ethyl ketone, acetone, and methanol were appropriately used.

―安定剤液１―
１．０ｇの安定剤１、０．３１ｇの酢酸カリウムをメタノール４．９７ｇに溶解し安定剤液を調製した。

-Stabilizer solution 1-
A stabilizer solution was prepared by dissolving 1.0 g of Stabilizer 1 and 0.31 g of potassium acetate in 4.97 g of methanol.

―赤外増感色素液Ａ―
１９．２ｍｇの赤外増感色素１、１．４８８ｇの２−クロロ−安息香酸、２．７７９ｇの安定剤２及び３６５ｍｇの５−メチル−２−メルカプトベンズイミダゾールを暗所にて３１．３ｍｌに溶解し、赤外増感色素液Ａを調製した。

-Infrared sensitizing dye solution A-
19.2 mg of infrared sensitizing dye 1, 1.488 g 2-chloro-benzoic acid, 2.7779 g stabilizer 2 and 365 mg 5-methyl-2-mercaptobenzimidazole to 31.3 ml in the dark It melt | dissolved and the infrared sensitizing dye liquid A was prepared.

《保護層組成》）
表面保護層塗布液を下記のように調製した。
セルロースアセテートブチレート ４ｇ／ｍ²
フタラジン ３．２×１０^-3ｍｏｌ／ｍ²
界面活性剤： Ｃ₉Ｆ₁₇Ｏ（ＣＨ₂ＣＨ₂Ｏ）₂₂Ｃ₉Ｆ₁₇ ２２ｍｇ／ｍ²
ＬｉＯ₃Ｓ（ＣＦ₂）₃ＳＯ₃Ｌｉ １０ｍｇ／ｍ²
溶媒には、メチルエチルケトン、アセトン、メタノールを適宜用いた。
《中間層組成》
ポリビニルブチラール ０．５ｇ／ｍ²
ポリメチルメタアクリレート ０．０４ｇ／ｍ²
溶媒には、メチルエチルケトン、アセトン、メタノールを適宜用いた。

<< Protective layer composition >>
A surface protective layer coating solution was prepared as follows.
Cellulose acetate butyrate 4g / m ²
Phthalazine 3.2 × 10 ⁻³ mol / 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
As the solvent, methyl ethyl ketone, acetone, and methanol were appropriately used.
《Interlayer composition》
Polyvinyl butyral 0.5g / m ²
Polymethyl methacrylate 0.04g / m ²
As the solvent, methyl ethyl ketone, acetone, and methanol were appropriately used.

The obtained photothermographic material samples 1 to 8 were evaluated for photographic performance as follows.
<Evaluation of photographic performance>
(Exposure / heat development)
Using a single channel cylindrical inner surface laser exposure apparatus equipped with a semiconductor laser with 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, a mirror rotation speed of 60000 rpm and an exposure time Exposure was performed under conditions of 1.2 × 10 ⁻⁸ seconds. The overlap coefficient at this time was 0.499, and the laser energy density on the surface of the photothermographic material was 75 μJ / cm ² . Next, a heat development treatment was performed at 121 ° C. for 20 seconds. The density of the obtained image was measured. The density was measured with a Macbeth TD904 densitometer (visible density).
Sensitivity was expressed as a logarithm of the reciprocal of the exposure amount giving a density of 1.5, and expressed as a relative value with the sensitivity of Sample 1 (comparison) as 100. The higher the value, the higher the sensitivity.
(Evaluation of development processing humidity dependency)
A sample conditioned at 23 ° C. and 80% for 12 hours and a sample conditioned at 23 ° C. and 20% for 12 hours were prepared, and a 50 μm line width exposure was performed under the above exposure conditions in the same environment. A heat development process was performed.
The line width of the obtained image was measured, and the difference between the line width of the sample conditioned at 23 ° C. and 80% for 12 hours and the line width of the sample conditioned at 23 ° C. and 20% for 12 hours [(23 ° C., 80 % Line width of sample conditioned for 12 hours)-(line width of sample conditioned at 23%, 20% for 12 hours)]. The smaller the line width difference, the better the storage stability.
Further, Dmin (fogging) of the obtained sample was measured, and Dmin (fogging) of the sample conditioned at 23 ° C. and 80% for 12 hours and Dmin (fogging) of the sample conditioned at 23 ° C. and 20% for 12 hours. [(Dmin of sample conditioned at 23 ° C., 80% for 12 hours) − (Dmin of sample conditioned at 23 ° C., 20% for 12 hours)]. The smaller the difference in Dmin (fogging), the better the storage stability.
The obtained results are shown in Table 1.

Example 2
Photothermographic material sample 11 as in Example 1 except that an acrylic hydrophobic resin layer having the following composition as shown in Table 2 is provided on the outermost layers of the heat-developable photosensitive material samples 1 to 8 of Example 1. -18 were produced.
(Acrylic hydrophobic resin layer composition)
Latex A (30%) 15g / m ²
Latex B (30%) 1.5 g / m ²
Microcrystalline wax 0.3g / m ²
Matting agent (particle size 2 μm) 50 mg / m ²

Latex A: styrene-butyl acrylate-glycidyl methacrylate = 20: 40: 40 (Tg = 20 ° C.)
Latex B: styrene-butyl acrylate-glycidyl methacrylate = 40: 20: 40 (Tg = 45 ° C.)
(Evaluation of raw preservation)
Each of the heat-developable photographic material samples 11 to 18 was divided into 2 minutes, one was left at room temperature, and the other was stored at 55 ° C. for 3 days to forcibly deteriorate. About each sample, it carried out similarly to having shown in Example 1, and calculated | required the sensitivity and Dmin (fogging).
The obtained results are shown in Table 2.

Claims (4)

On the support, an image forming layer containing a non-photosensitive organic silver salt, a photosensitive silver halide, and a reducing agent is applied, and the image forming layer is coated with a coating solution containing 30% by mass or more of an organic solvent. A photothermographic material which is formed and contains a nucleating agent represented by the following general formula (1) in an image forming layer or a layer provided adjacent to the image forming layer.

[Wherein R ₁₁ represents a monovalent substituent, R ₁₂ represents an electron-withdrawing group, one of R ₁₃ and R ₁₄ represents a hydrogen atom, and the other represents an oxygen anion or a sulfur anion, R ₁₅ represents an ammonium ion, a phosphonium ion, or a sulfonium ion. ] 2. The photothermographic material according to claim 1, wherein R ₁₁ in the general formula (1) is an aryl group or an aromatic heterocyclic group. In the general formula (1), heat-developable photographic material according to claim 1 or 2, characterized in that R ₁₂ is a cyano group. An outermost layer is provided on the image forming layer side, and the outermost layer is an acrylic hydrophobic resin layer containing microcrystalline wax and / or paraffin wax formed from a coating solution containing 30% by mass or more of water as a coating solvent. The photothermographic material according to claim 1, wherein the photothermographic material is a photothermographic material.