JP2005062739A - Photothermographic imaging material and developing method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photothermographic imaging material having high sensitivity and low fog and excellent in storage stability before development (raw stock preservability) and in storage stability after development (image preservability), and to provide a developing method for the same. <P>SOLUTION: In the photothermographic imaging material in which a photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a reducing agent and a binder is located on a support, a photographic chemical agent is incorporated after it is stored in carbon nanotubes or carbon nanohorns provided with a light responsive group. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a photothermographic image forming material in which a photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a reducing agent and a binder is provided on a support, and a developing method thereof.

  In recent years, there has been a strong demand for photothermographic materials that do not generate waste liquids due to wet processing in terms of environmental protection and workability in the medical and printing fields. In particular, high-resolution and clear black images can be formed by thermal development. There is a need for techniques relating to photothermographic materials that can be used for photographic technology. Since these photographic materials are developed at a temperature of 100 ° C. or higher, they are called photothermographic image forming materials.

  Conventionally, this type of photothermographic image-forming material has absorbed a photosensitive layer containing high-sensitivity silver halide grains spectrally sensitized with a dye, an organic silver salt and a reducing agent, and light irradiated to the photosensitive layer. It consists of an anti-irradiation layer that prevents the light from being diffusely reflected at the interface, intermediate layer, adhesive layer, etc. of the support, or a backing layer provided on the opposite side of the support, if necessary. A protective layer is provided on the top and the backing layer to prevent scratching during handling.

  In general, photothermographic image forming materials are easy to process because they produce an image only by heat development after exposure. However, since a reducing agent is incorporated in the photosensitive layer, it is important to improve the storability of the image before and after development. ing. In order to obtain high sensitivity, chemical sensitization of silver halide and spectral sensitization with sensitizing dyes are indispensable. ing. In order to improve the storage stability when chemical sensitization is performed, in order to reduce the influence of the temperature during storage, it is better to develop at a temperature as high as possible so that a clear image can be obtained. If it becomes, it will become easy to produce fog and a sensitivity will fall. Therefore, development is generally performed at a temperature around 120 ° C. ± 10 ° C.

The use of a mercapto compound to reduce fog is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-19681. However, mercapto compounds have little effect of suppressing fogging, and it is difficult to obtain high sensitivity, and there is a limit to improving storage stability. The polyhalomethane compound used for suppression of printout silver due to exposure to Saucusten at the time of image interpretation after development processing is disclosed in, for example, JP-A-9-319022, which is effective for fog suppression and raw storage. There was a limit because the sensitivity decreased when the amount used was large. In order to improve the storage stability, attempts have been made to use a compound known as a crosslinking agent for a binder, but it has not been sufficient. Although a technique for inserting a magnetic substance, a semiconductor, a gas, and the like into a carbon nanotube (see, for example, Patent Document 1) has been disclosed, no attempt has been made to release a drug for improving storage stability.
JP-A-6-227806, pages 1-6

  An object of the present invention is a photothermographic image forming material having high sensitivity, low fog, and excellent storage stability before development (abbreviated as raw storage) and storage stability after development (abbreviated as image storage) and development method thereof Is to provide.

  The above object of the present invention is achieved by the following configurations.

  Claim 1. In a photothermographic image forming material in which a photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a reducing agent and a binder is provided on a support, the photographic agent is a carbon nanotube or carbon provided with a photoresponsive group A photothermographic image-forming material which is stored in a nanohorn and contained in the photosensitive layer.

  Claim 2. Storage in the carbon nanotube or carbon nanohorn provided with the photoresponsive group of the photochemical agent, after mixing the carbon nanotube or the carbon nanohorn and the compound having the photoresponsive group, ultrasonic treatment, and then adding the photochemical agent, 2. The photothermographic image forming material according to claim 1, wherein the photothermographic image forming material is subjected to high vacuum processing, washing, and light irradiation.

  Claim 3. The photothermographic image-forming material according to claim 2, wherein the compound having a photoresponsive group has a reactive double bond.

  Claim 4. The photothermographic image forming material according to any one of claims 1 to 3, wherein the photoresponsive group has a stilbene structure or an azobenzene structure.

  Claim 5. 5. The photothermographic image forming material according to claim 1, wherein the photographic agent is one selected from a phthalazine compound, a halomethane compound, and a reducing agent.

  Claim 6. A method for developing a photothermographic image forming material, comprising: irradiating the photothermographic image forming material according to any one of claims 1 to 5 with a laser beam of 400 to 900 nm, followed by heat development.

  By using the stored phthalazine, halomethane compound and reducing agent of the present invention, it was possible to provide a photothermographic image forming material excellent in photographic performance (sensitivity and fog characteristics), raw storability and image storability. .

  Hereinafter, the present invention will be described in detail.

  The photothermographic image-forming material of the present invention usually comprises at least two layers comprising a support on which at least one photosensitive layer and a layer adjacent to the photosensitive layer are provided. A backing layer provided on the opposite side, a protective layer thereof, and the like are included. The photosensitive layer of the photothermographic image forming material contains photosensitive silver halide grains that may be sensitized with a spectral sensitizing dye, and the photosensitive layer or an adjacent layer thereof is an organic silver serving as a silver source. A reducing agent for forming a silver image by developing a salt or a silver salt is contained, and a photographic agent is stored and contained in a carbon nanotube or carbon nanohorn provided with a photoresponsive group. As photographic agents, phthalazine compounds, halomethane compounds and reducing agents are preferred, and carbon nanotubes or carbon nanohorns provided with photoresponsive groups are hereinafter referred to as storage agents.

  In the above-mentioned photothermographic image forming material, a layer containing a dye for preventing irradiation or preventing halation is provided if necessary.

  Hereinafter, the stored phthalazine compound, halomethane compound and reducing agent contained in the photothermographic image forming material of the present invention will be described in detail. Further, the photosensitive silver halide grains contained in the photosensitive layer of the photothermographic image forming material, the organic silver salt contained in the photosensitive layer or its adjacent layer, the reducing agent, and the polymer contained in the photosensitive layer or its adjacent layer. The binder and the like will be sequentially described later.

  A carbon nanotube is a very small material having a fiber-like structure in which one or several cylinders with rounded graphite-like carbon atoms are arranged in a nested manner, and the diameter is a nanometer order size. Until now, carbon fibers with a diameter of micron or more have been known for a long time. However, a tube having a diameter of nanometer range was reported in 1991 [Nature 1991, 354, pp. 56-58] for the first time and has attracted a great deal of attention as a one-dimensional conductive wire, catalyst, and super-reinforced structure material from all over the world. In particular, the electrical properties of each carbon tube forming the nested state of carbon nanotubes were investigated (Physical Review Letter, 1992, 68, pp. 1579-1581), depending on the diameter and pitch of the helical structure. It has become a great expectation for the usefulness of this material that the electrical properties of carbon nanotubes have been clarified by having band gaps of various sizes.

  In the carbon nanotube used in the present invention, the tube at the center of the nested cylinder has a diameter of several angstroms or more, and this portion has a cylindrical space. If a photographic drug is stored in this space, the development reaction is suppressed during storage, and it can be quickly changed to a state where it is likely to react during development, the performance of the photothermographic image forming material can be improved. For example, if a development accelerator such as a reducing agent or a phthalazine compound is stored and released during development, fogging during storage can be suppressed. Regarding the suppression of light fog after development, if the light fog suppressant is stored in a storage agent and can be in a state capable of suppressing light fog after development, desensitization before development can be suppressed. In the present invention, the above possibilities have been intensively verified to confirm their usefulness.

  Since the side surfaces of the carbon nanotubes are almost all made of a six-membered ring, the structure is somewhat complete, and the structure of the carbon nanotubes is not destroyed even when an organic compound is contacted. In addition, organic compounds are not easily intercalated between the layers of the tubes forming the nested structure. In the case of ordinary graphite, a graphite-like carbon plane extending in two dimensions (xy plane) is connected by van der Waals force between each layer, but the layer spacing is xy plane. It spreads freely in a direction perpendicular to Therefore, a specific organic compound can be introduced between the layers, and an intercalating compound can be produced. However, in the case of carbon nanotubes, each cylindrical tube is strong, the diameter of the cylinder is structurally fixed, and the layer spacing hardly changes. For this reason, in general, an intercalation compound containing an organic compound cannot be formed between carbon nanotube layers. However, since the hollow hole in the center of the carbon nanotube is large enough to contain a low molecular organic compound, a carbon nanotube in which the low molecular organic compound is stored can be formed. Even when the above-described spread of π electrons is taken into consideration, the space in which the low-molecular compound enters and encapsulates is not blocked.

  When storing in the carbon nanotube, the diameter of the carbon nanotube may be increased. There are currently various methods for synthesizing carbon nanotubes. In the case of laser vapor deposition, the diameter distribution of carbon nanotubes to be produced can be controlled by adjusting the type of catalyst and the temperature of the electric furnace.

  Similar to carbon nanotubes, there is a material called carbon nanohorn, which has different diameters at both ends, and is a conical or truncated cone structure sandwiched between a large part and a small part. Can also be carried out according to the carbon nanotube, and can be positioned as a modification of the carbon nanotube of the present invention. The surface of a cylindrical carbon nanotube is usually covered with a 6-membered graphite structure. If a 5-membered or 7-membered ring is mixed with this 6-membered ring, the diameter of the tube will be reduced or expanded. It is known to do. Therefore, conical carbon nanohorns have a horn diameter that changes continuously, so that the graphite structure on the surface tends to be irregular compared to cylindrical carbon nanotubes, and the surface activity is high, making it easy to add functional groups. Yes, it can also improve hydrophilicity. Carbon nanohorns having a hydrophilic functional group added are extremely easily dispersed in an aqueous solvent, and part of the carbon nanohorn becomes water-soluble, which is suitable for sensitization of silver halide grains dispersed in an aqueous solution.

  The method for storing the photographic drug used in the present invention is, for example, by enclosing the carbon nanotube provided with the photoresponsive group and the photographic drug in a quartz tube under high vacuum, and then lower than the decomposition temperature of the photographic drug. Hold at temperature for 2-6 hours. At this temperature, the photographic agent is vaporized or sublimated and penetrates into the carbon nanotube. After the reaction, the sample was ultrasonically washed in toluene to remove the photographic agent of the present invention attached to the outside of the carbon nanotube. Furthermore, a photographic drug is stored by light irradiation.

  The amount stored in the carbon nanotube depends on the inner diameter and length of the carbon nanotube, but is about 1 to 1000 molecules. The inner and outer diameters of the carbon nanotubes are preferably 2 to 200 nm.

  A method for providing a photoresponsive group on a carbon nanotube or carbon nanohorn by bonding a compound having a photoresponsive group to the carbon nanotube or carbon nanohorn will be described.

  Carbon nanotubes or carbon nanohorns basically have a benzene structure, and all organic reactions that react with benzene to form bonds can be used. A method of giving a reactive group to a compound having a photoresponsive group and reacting with a carbon nanotube or carbon nanohorn is common, and specific examples include Friedel-Crafts reaction and Diels-Alder reaction. Among these, a method in which a reactive double bond is introduced into a compound having a photoresponsive group and ultrasonic waves are used as reaction energy is most advantageous. Moreover, the method of introduce | transducing a functional group into a carbon nanotube or carbon nanohorn, and forming a bond from it can also be taken. For example, a carbon nanotube can be nitrated and reduced to introduce an amino group as a functional group, and then a bond can be formed.

  The intensity of the ultrasonic wave to be applied is not particularly limited, but is preferably 10 W to 2 kW. In addition, the introduction amount of the organic substituent can be increased by lengthening the ultrasonic irradiation time. The conditions for ultrasonic irradiation are not particularly limited. For example, you may have processes, such as dielectric heat processing, washing | cleaning, and refinement | purification.

  Functional groups that can be used as photoresponsive groups include groups that are reversible in structural transformations, except for groups that change in molecular weight when oxidized or reduced by groups that induce cis-trans structural transformations with light. Is preferred. In particular, a compound having a vinyl group or an azo group is preferable, and specifically, a compound having a stilbene structure or an azobenzene structure. For example, the following compounds such as m-1, m-2 and m-3 may be introduced into carbon nanotubes or carbon nanohorns.

  The photoresponsive group is converted into a cis form by irradiation with ultraviolet light, that is, light having a wavelength of 400 nm or less, and the release of the photographic drug can be suppressed. And it can convert into a trans body by irradiating with light with a wavelength of 400-900 nm, and can accelerate | stimulate discharge | release of the chemical | medical agent for photography.

The storage amount of the stored photographic drug is preferably used in the range of 1 × 10 ⁻³ to 1 × 10 ³ g with respect to 1 mol of silver halide. Addition method is dissolved in water, alcohol (eg, methanol, ethanol, isobutyl alcohol, etc.), ketones (eg, acetone, methyl ethyl ketone, isobutyl ketone, etc.), aromatic organic solvent (eg, toluene, xylene, etc.) and added. Alternatively, fine particles may be dispersed and added. In this case, jet mill dispersion, ultrasonic dispersion or homogenizer dispersion is carried out to form fine particles of 1 μm or less, and if necessary, a surfactant or viscosity modifier can be added and dispersed in water or an organic solvent. .

  The storage phthalazine compound of the present invention exhibits a development accelerating action, and its mechanism acts as a carrier for forming silver ions from an organic silver salt to form silver phthalazine complexes and supplying them to the silver particles of the physical development nucleus. It can be obtained by introducing various substituents into the phthalazine ring. A preferred phthalazine compound can be represented by the general formula (1).

In the formula, R ^{2 to} R ⁷ are each independently a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group, an alkyl group that may have a substituent, an alkenyl group, an alkynyl group, an alkoxy group, an aromatic group, Represents a heterocyclic group. The function of the substituent may be a group such as a group that controls diffusibility, an adsorptive group, or an acidic group. 1-60 are preferable and, as for carbon number of an alkyl group, an alkenyl group, an alkynyl group, and an alkoxy group, 1-40 are especially preferable. When the number of carbon atoms is more than 40, good effects on fog suppression, color tone, and storage stability cannot be obtained. The method for synthesizing phthalazine can be synthesized with reference to WO 96 / 5176A pamphlet. Specific examples of preferred phthalazine compounds are shown below.

  The stored halomethane compound of the present invention is used as an inhibitor of light fog, and its mechanism is considered to generate halo radicals by heat and light and bleach the fog nuclei of silver halide grains, and generate radicals at room temperature as much as possible. It is preferable to generate a halo radical capable of bleaching fog nuclei when subjected to the action of heat or light without undergoing the cleavage reaction.

  In order to bring out this property, it is preferable to design a molecular structure incorporating a radical stabilization mechanism in the substituent of the trihalomethane group. Usually, a compound having at least one trihalomethane group or dihalomethane group in one molecule is preferable, and in particular, the halomethane group is an aliphatic group, an aromatic ring group or a heterocycle via a linking group which controls radical stability. Those bonded to a cyclic group are preferred. The aromatic ring or hetero ring may be further connected to the aromatic ring or hetero ring via a divalent linking group. The aromatic ring group is preferably a phenyl group or a naphthalene group, and a halogen atom (for example, a chlorine atom, a bromine atom, or a fluorine atom), an alkyl group (for example, a methyl group, an ethyl group, a butyl group, an octyl group, Dodecyl group, octadecyl group) may be substituted, and examples of the heterocyclic group include pyridine group, pyrimidine group, quinoline group, furan ring group, thiophene ring group, imidazole group, triazole group, oxazole group, thiazole group, thiadiazole Group, oxadiazole group, etc., and these rings may have the same substituent as the aromatic ring.

  Further, a group for imparting diffusion resistance or a group that promotes adsorption to silver halide may be substituted on the aromatic ring or the hetero ring. A group adjacent to a trihalomethane group or a dihalomethane group is preferably a sulfonyl group or a carbonyl group, but may be directly bonded to an aromatic ring or a heterocyclic ring, and the bonding method is not limited. The aromatic ring or hetero ring is particularly preferably a ring group that is completely or partially reduced. The halogen atom of the trihalomethane group or dihalomethane group is preferably a bromine atom, but may be chlorine, fluorine, iodine, or a combination thereof. A preferred structure is shown in the following general formula (2).

In the formula, X ¹ , X ² and X ³ are each independently a hydrogen atom, a halogen atom (eg, bromine atom, chlorine atom, etc.), an acyl group (eg, acetyl group, benzoyl group, etc.) or an alkoxycarbonyl group (eg, methoxy). Carbonyl group, ethoxycarbonyl group, etc.), aryloxycarbonyl group (phenoxycarbonyl group, naphthyloxy bank carbonyl group, etc.), sulfonyl group, alkyl group (eg, methyl group, ethyl group, etc.) or aryl group (eg, phenyl group, Naphthyl group), at least two of which are halogen atoms. L ₁ represents —C (═O) —, —SO— or —SO ₂ —, and p represents 0 or 1.

The ring represented by Z ₂ may be a saturated or unsaturated monocyclic or condensed ring, preferably a monocyclic or bicyclic group having 6 to 30 carbon atoms (for example, an adamantyl group, a cyclobutane group, a cyclopropane group) Group, cyclopentane group, cyclooctane group, cyclobutene group, cyclopentene group, cyclohexene group, phenyl, naphthyl, etc., more preferably adamantyl group, cyclopentane group, cyclohexane group, cyclohexene group, cyclohexanone group, cyclopentene group, phenyl. A naphthyl group, more preferably a phenyl group.

When Z ₂ is a heterocyclic ring, it is a 3- to 10-membered saturated or unsaturated heterocyclic group containing at least one atom of N, O, or S, and these may be monocyclic or other A condensed ring may be formed with this ring. The heterocyclic group is preferably a 5- or 6-membered saturated or unsaturated heterocyclic group which may have a condensed ring, and more preferably a 5- to 6-membered aromatic group which may have a condensed ring. It is a heterocyclic group. More preferably, it is a 5- or 6-membered saturated or unsaturated heterocyclic group optionally having a condensed ring containing a nitrogen atom, and particularly preferably a condensed ring containing 1 to 4 nitrogen atoms. A good 5- to 6-membered unsaturated heterocyclic group.

  The heterocyclic ring in such a heterocyclic group includes imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, phospholene, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline Pteridine, acridine, phenanthroline, phenazine, tetrazole, thiazole, oxazole, benzimidazole, benzoxazole, benzthiazole, indolenine, tetrazaindene, more preferably imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, Thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, te Razole, thiazole, oxazole, benzimidazole, benzoxazole, benzthiazole, tetrazaindene, more preferably imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, Cinnoline, tetrazole, thiazole, benzimidazole and benzthiazole, particularly preferably piperidine, piperazine, pyridine, thiadiazole, quinoline and benzthiazole. Specific examples of these compounds are listed below.

The halomethane compound used in the present invention is preferably added in an amount of 1 × 10 ⁻² to 1 × 10 ³ mol per mol of silver halide. The position of addition need not be limited to the photosensitive layer in which silver halide exists, and may be an adjacent layer or an undercoat layer. The addition method can be performed in the same manner as the above-mentioned stored phthalazine compound.

  The stored reducing agent of the present invention is contained in a photothermographic image forming material and exhibits a reducing action by heat development. US Pat. Nos. 3,770,448, 3,773,512, 3, What is described in each specification, such as 593,863, can be mentioned. Particularly preferred reducing agents are hindered phenols. Examples of the hindered phenols include compounds represented by the following general formula (3).

In the formula, R is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (for example, —C ₄ H ₉ , 2,4,4-trimethylpentyl), an aromatic ring group (for example, a phenyl group, a naphthyl group, Cyclopentadienyl group, cyclohexenyl group, etc.) or heterocyclic group (furyl group, thiophenyl group, pyridyl group, oxazolyl group, thiazolyl group, etc.), and R ′ and R ″ are not all hydrogen atoms. Each independently represents a straight-chain or branched alkyl group having 1 to 25 carbon atoms (for example, methyl, ethyl, t-butyl), and in particular, R is preferably an unsaturated ring group, A cyclohexenyl group is preferred.

  Specific examples of the compound represented by the general formula (3) are shown below. However, the present invention is not limited to the following compounds.

The amount of the stored reducing agent including the compound represented by the general formula (3) is preferably 1 × 10 ⁻² to 10 mol, particularly 1 × 10 ^{−2 to} 3 mol, per mol of silver. It is. It is not necessary to store all the reducing agent, and it may be stored 10 to 98%. As the addition method, a method similar to the addition method of the stored phthalazine compound can be adopted.

  Next, organic silver salts, photosensitive silver halide grains, binders, dyes, matting agents and other supports used in the photothermographic image forming material of the present invention will be described in order.

  Organic silver salts are reducible silver sources, and organic acids, heteroorganic acids, silver salts of acid polymers, and the like containing reducible silver ion sources are used. Also useful are organic or inorganic silver salt complexes whose ligands have a total stability constant for silver ions of 4.0 to 10.0. Examples of silver salts are described in Research Disclosure Nos. 17029 and 29963 and include the following: salts of organic acids (eg, gallic acid, oxalic acid, behenic acid, arachidic acid, stearic acid, palmitic acid, lauric acid Salts of acids and the like).

  The photosensitive silver halide contained in the photosensitive layer of the photothermographic image-forming material of the present invention can be obtained by any method known in the field of photographic technology such as a single jet method or a double jet method, such as an ammonia emulsion. It can be prepared in advance by any method such as an acid method or an acidic method, and then mixed with the other components of the present invention and introduced into the composition used in the present invention. In this case, in order to sufficiently contact the photosensitive silver halide and the organic silver salt, for example, U.S. Pat. Nos. 3,706,564 and 3,706 are used as protective polymers when preparing the photosensitive silver halide. No. 565, No. 3,713,833, No. 3,748,143, British Patent No. 1,362,970, a means using a polymer other than gelatin, such as polyvinyl acetals, , Means for enzymatic degradation of light sensitive silver halide emulsion gelatin as described in GB 1,354,186, or as described in US Pat. No. 4,076,539 Thus, each means such as a means for omitting the use of the protective polymer can be applied by preparing the photosensitive silver halide grains in the presence of a surfactant.

  The photosensitive silver halide preferably has a small grain size in order to keep white turbidity after image formation low and to obtain good image quality. The average particle size is 0.1 μm or less, preferably 0.01 to 0.1 μm, particularly preferably 0.02 to 0.08 μm. Further, the shape of the silver halide is not particularly limited, and examples thereof include cubic and octahedral so-called normal crystals and non-normal crystals such as spherical, rod-like, and tabular grains. The silver halide composition is not particularly limited and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide.

  The amount of the silver halide is 50% by mass or less, preferably 25 to 0.1% by mass, more preferably 15 to 0.1% by mass, based on the total amount of the silver halide and the organic silver salt described later. Various conditions such as reaction temperature, reaction time, reaction pressure, etc. in the step of converting a part of the organic silver salt into silver halide using the above-mentioned silver halide forming component can be appropriately set according to the purpose of preparation. Usually, the reaction temperature is −20 to 70 ° C., the reaction time is 30 seconds to 15 hours, and the reaction pressure is preferably set to atmospheric pressure.

  The photosensitive silver halide prepared by the various methods described above is an unstable chalcogen compound such as an unstable sulfur-containing compound, an unstable selenium compound or an unstable tellurium compound alone or in combination. , Platinum compounds, palladium compounds, or combinations thereof can be chemically sensitized. Regarding the method and procedure of this chemical sensitization, for example, specifications such as U.S. Pat. No. 4,036,650 and British Patent No. 1,518,850, JP-A-51-22430, 51-78319, etc. No. 51-81124 and the like. Further, when a part of the organic silver salt is converted to photosensitive silver halide by the silver halide forming component, a sensitizer is present as described in US Pat. No. 3,980,482. You may let them. Preferred chalcogen compounds for the present invention include unstable sulfur compounds, unstable thiuonium compounds, unstable selenium compounds, and unstable tellurium compounds.

  These photosensitive silver halides include metals belonging to groups 6 to 10 of the periodic table of elements, such as Rh, Ru, Re, Ir, Os, Fe, etc., for illuminance failure and gradation adjustment. Ions, their complexes or complex ions can be included. In particular, it is preferable to contain ions or complex ions of metals belonging to Groups 6 to 10 of the Periodic Table of Elements. As the above metal, W, Fe, Co, Ni, Cu, Ru, Rh, Pd, Re, Os, Ir, Pt, and Au are preferable. Among them, when used for a photosensitive material for printing plate making, Rh, Re, It is preferably selected from Ru, Ir, and Os. These metals can be introduced into the silver halide in the form of a complex.

The content of metal ions or complex ions is generally 1 × 10 ⁻⁹ to 1 × 10 ⁻² mol per mol of silver halide, preferably 1 × 10 ⁻⁸ to 1 × 10. ^-4 moles. The compounds providing these metal ions or complex ions are preferably added at the time of silver halide grain formation and incorporated into the silver halide grains. Preparation of silver halide grains, that is, nucleation, growth, physical ripening , May be added at any stage before or after chemical sensitization, but is preferably added at the stage of nucleation, growth and physical ripening, more preferably at the stage of nucleation and growth, most preferably Preferably, it is added at the stage of nucleation. In addition, it may be divided and added several times, or it can be uniformly contained in the silver halide grains. JP-A-63-29603, JP-A-2-306236, 3 As described in publications such as 167545, 4-76534, 6-110146, and 5-273683, the particles can be contained with a distribution. Preferably, a distribution can be provided inside the particles.

  These metal compounds can be added by dissolving in water or an appropriate organic solvent (for example, alcohols, ethers, glycols, ketones, esters, amides). A method of adding an aqueous solution or a metal compound and an aqueous solution in which NaCl and KCl are dissolved together to a water-soluble silver salt solution or a water-soluble halide solution during particle formation, or a silver salt solution and a halide solution are simultaneously mixed. When adding a third aqueous solution, a method of preparing silver halide grains by a three-liquid simultaneous mixing method, a method of adding an aqueous solution of a required amount of a metal compound to the reaction vessel during grain formation, or silver halide There is a method of adding another silver halide grain previously doped with a metal ion or complex ion at the time of preparation and dissolving it. In particular, a method of adding an aqueous solution of a metal compound powder or an aqueous solution in which a metal compound and NaCl, KCl are dissolved together is added to the water-soluble halide solution. When added to the particle surface, a necessary amount of an aqueous solution of a metal compound can be charged into the reaction vessel immediately after the formation of the particle, during or after the physical ripening, or at the chemical ripening.

  The sensitizing dye used in the present invention is, for example, as required, for example, JP-A Nos. 63-159841, 60-140335, 63-231437, 63-259651, 63-304242, 63-15245. No. 4,639,414, US Pat. No. 4,740,455, US Pat. No. 4,741,966, US Pat. No. 4,751,175, US Pat. No. 4,835,096, etc. Sensitizing dyes described in the specification can be used. Useful sensitizing dyes used in the present invention are described in, for example, the literature described or cited in Research Disclosure Item 17643IV-A (December 1978, p.23) and Item 1831X (August 1978, page 437). Has been described. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, compounds described in JP-A Nos. 9-34078, 9-54409, and 9-80679 are preferably used.

  As a binder used for the photosensitive layer or the non-photosensitive layer of the photothermographic image forming material of the present invention, a material preferable as a place where a photosensitive silver halide, an organic silver salt and a reducing agent react is selected. The binder is a polymer, for example, a polymer used by dissolving in a polar solvent including alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone and acetone, dimethyl sulfoxide and dimethylformamide, and an aqueous dispersion polymer. Any of the binders for the photothermographic image-forming material of the present invention may be used. Further, regarding the preferred polymer composition, the glass transition point is preferably from -20 ° C to 80 ° C, particularly preferably from -5 ° C to 60 ° C. This is because when the glass transition point is high, the temperature at which heat development is performed becomes high, and when the glass transition point is low, fogging is likely to occur, and the sensitivity is lowered or softened.

  Examples of the polymer used by dissolving in the above polar solvent include cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, and ethyl cellulose, starch and derivatives thereof, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl butyral, sodium polyacrylate, Polyethylene oxide, acrylic amide-acrylic ester copolymer, styrene-maleic anhydride copolymer, polyacrylamide, sodium alginate, gelatin, casein, polystyrene, polyvinyl acetate, polyurethane, polyacrylic acid, polyacrylic ester, Styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, vinyl chloride-vinyl acetate copolymer, styrene-butadiene- Such as acrylic copolymers.

  Further, after drying, after forming a film, those having a low equilibrium water content of the coating film are preferred. Particularly those having a low water content include, for example, cellulose acetate, cellulose acetate butyrate, poly (methyl methacrylic acid) and the like. (Acrylic acid esters), poly (acrylic acid), poly (methacrylic acid), poly (vinyl chloride), copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly ( Vinyl acetals) (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethanes), phenoxy resins, poly (vinylidene chloride), poly (epoxides), poly (carbonates) ), Poly (vinyl acetate), cellulose esters, poly (amino) ) S can be mentioned.

  By forming a film of the binder alone, it is possible to maintain adhesion to the lower layer and upper layer and to obtain a film strength that is difficult to get scratched. However, by using a crosslinking agent, the film adhesion and film strength can be further increased. Can do. In addition, the crosslinking agent can not only improve the film physical properties but also improve fog suppression and storage stability. The mechanism is considered as follows. Amine compounds produced by corona discharge treatment on the surface of the support or the undercoat layer migrate to the coated photosensitive layer and increase fogging. However, the presence of a crosslinking agent that captures or inactivates the amine compound suppresses the generation of fog. The generation of the amine compound is due to the fact that nitrogen in the air, hydrogen atoms in the film, and in some cases, oxygen atoms, etc., enter a plasma state during corona discharge, and the rearrangement of atoms proceeds. Ammonia water used as a pH regulator is also considered to be left in the reaction as a causative substance for fogging. In addition, it is presumed that there are amine compounds as degradation products that are generated after sensitization in the use of chalcogen sensitizers or those that increase fog in trace amounts of impurities in materials used as photographic additives. ing.

  In using the crosslinking agent, there are a method of adding to the undercoat layer, AH layer, photosensitive layer, protective layer, backing layer or backing protective layer. From the viewpoint of the stability of the coating solution, it is preferably added using a static mixer immediately before coating, but may be added at the time of preparing the coating solution. A preferred crosslinking agent is a crosslinking agent having an isocyanate group or a vinylsulfonyl group. Particularly preferred crosslinking agents include polyfunctional crosslinking agents having at least 2, more preferably 3, isocyanate groups or vinylsulfonyl groups. JP, 2003-2874, A can be referred to for the synthesis method of a vinyl sulfonyl compound. H-1 to H-13 are shown below as preferred crosslinking agents.

(H-1) Hexamethylene diisocyanate (H-2) Trimer of hexamethylene diisocyanate (H-3) Tolylene diisocyanate (H-4) Phenylene diisocyanate (H-5) Xylylene diisocyanate Naruto

The compound having an isocyanate group or vinylsulfonyl group used in combination with the stored photographic agent of the present invention is preferably added in an amount of 1 × 10 ⁻² to 1 × 10 ² mol per mol of silver halide. The position of addition need not be limited to the photosensitive layer in which silver halide exists, and may be an adjacent layer or an undercoat layer. The adding method can be added by the same method as that for storing photographic drugs.

  The photothermographic image-forming material of the present invention is provided with an AI layer or backing layer for preventing irradiation or antihalation of the photothermographic image-forming material, if necessary, and the dye used for the AI layer or backing layer is an image. Any dye can be used as long as it absorbs exposure light. Preferably, the above-described thermodecolorable dyes described in US Pat. No. 5,384,237 are used. If the dye used is not thermodecolorable, the amount used is limited to a range that does not affect the photothermographic image-forming material, but if it is a thermodecolorable dye, a sufficient amount of dye is necessary if necessary. Can be added.

  The matting agent may be either organic or inorganic. Examples of the inorganic matting agent include silica described in Swiss Patent No. 330,158 and polystyrene or polysiloxane described in Swiss Patent No. 330,158. Methacrylate, polyacrylonitrile described in US Pat. No. 3,079,257, polycarbonate described in US Pat. No. 3,022,169, and the like can be used.

  The shape of the matting agent may be either a regular shape or an irregular shape, but a regular and spherical shape is preferably used. The size of the matting agent is represented by a diameter when the volume of the matting agent is converted into a sphere. In the present invention, the particle size of the matting agent indicates the diameter converted into a spherical shape. The matting agent used in the present invention preferably has an average particle size of 0.5 to 10 μm, more preferably 1.0 to 8.0 μm. The monodispersity of the particles is preferably 50 or less, more preferably 40 or less, and particularly preferably 20 or less. Here, the monodispersity of the particles is represented by a number obtained by dividing the standard deviation of the particle size by the average value of the particle size and multiplying by 100. The method for adding the matting agent according to the present invention may be a method in which the matting agent is dispersed and applied in advance in the coating solution, or a method in which the matting agent is sprayed after the coating solution is applied and before drying is completed. May be.

  As the support, a support such as paper, synthetic paper, non-woven fabric, metal foil, and plastic film can be used, and a composite sheet combining these may be arbitrarily used.

  As the exposure method, laser exposure can be performed by the methods described in JP-A-9-304869, JP-A-9-311403, and JP-A-2000-10230.

  As an apparatus for developing a photothermographic image forming material, apparatuses described in JP-A Nos. 11-65067, 11-72897, and 11-84619 can be used.

  Examples of the present invention will be described below, but the embodiments of the present invention are not limited thereto.

<Production of carbon nanotubes>
The diameter distribution of the carbon nanotubes was controlled by adjusting the type of catalyst and the temperature of the electric furnace using a laser deposition method, and carbon nanotubes having a diameter of about 10 nm and a length of about 40 nm were synthesized. An alloy catalyst of Ni and Co was used as the catalyst. The carbon nanotube synthesis conditions are shown below. Target: Ni / Co (0.4 / 0.4% by mass) catalyst-containing graphite target, atmosphere gas: argon 380 Torr, electric furnace temperature: 1250 ° C., laser output: 260 mJ / pulse (10 Hz), laser spot size: 6 mm The nanotube content was 65%. This soot was purified by the hydrogen peroxide reflux method, and high purity nanotubes could be obtained.

《Storing Photographic Drug》
The obtained carbon nanotube was dispersed in 300 ml of toluene (solid content: 8% by mass) and reacted with an azobenzene compound serving as a photoresponsive group. Specifically, m-1 was used as the photoresponsive group for storing the phthalazine compound, m-2 was used for the halomethane compound, and m-3 was used for the reducing agent. The reaction promoting ultrasonic wave used an output of 100 W and a frequency of 700 KHz. The obtained carbon nanotube provided with the photoresponsive group and the photographic agent were sealed in a Pyrex (R) tube under high vacuum, and then maintained at a temperature of 260 ° C. for 3 hours. At this temperature, the photographic agent (phthalazine compound, halomethane compound, reducing agent) used in the invention was evaporated, vaporized or sublimated and introduced into the carbon nanotube.

Next, cis-formation of the photoresponsive group was performed by irradiating an ultrahigh pressure mercury lamp of 365 nm with 120 mJ / cm ² .

  After the reaction, the sample was ultrasonically washed in toluene to remove the photographic agent attached to the outside of the carbon nanotube. The average content was 5% by mass for the phthalazine compound, 4% by mass for the halomethane compound, and 3% by mass for the reducing agent. In the preparation of the photothermographic image forming material, the compound containing any compound and the compound not containing were used in a molar ratio of 1: 1.

《Preparation of underdrawn support》
The both sides of a 175 μm thick polyethylene terephthalate support were subjected to a corona discharge treatment of 600 W / m ² · min, and the following undercoat coating solution a-1 was applied on one surface to a dry film thickness of 0.8 μm. The undercoat layer A-1 is provided by drying, and the following undercoat coating solution b-1 is applied on the opposite surface so as to have a dry film thickness of 0.8 μm and dried to form the undercoat layer B-1. Provided.

<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
Finish to 1L with water <Undercoating liquid b-1>
Copolymer latex solution of butyl acrylate (40% by mass) / styrene (20% by mass) / glycidyl acrylate (40% by mass) (solid content 30%)
270g
Hexamethylene-1,6-bis (ethylene urea) 0.8g
Finish to 1L with water.

Subsequently, 600 W / m ² · min of corona discharge was applied to the upper surfaces of the undercoat layer A-1 and the undercoat layer B-1, and the following undercoat upper layer coating solution a-2 was applied on the undercoat layer A-1. Is coated and dried so as to have a dry film thickness of 0.8 μm, and an undercoat upper layer A-2 is provided. The undercoating upper layer B-2 was provided by applying and drying so as to be 8 μm.

<Undercoating upper layer coating solution a-2>
Gelatin 0.43 g / m ²
Silica particles (average particle size 3 μm) 0.01 g / m ²
Finish to 1L with water <Undercoating upper layer coating solution b-2>
Styrene butadiene copolymer latex liquid (solid content 20%) 0.08 g / m ²
Polyethylene glycol (weight average molecular weight 600) 0.06 g / m ²
Finish to 1L with water.

<Preparation of silver halide grain emulsion A>
After dissolving 7.5 g of inert gelatin and 10 mg of potassium bromide in 900 ml of water and adjusting the temperature to 28 ° C. and pH to 3.0, bromide with a molar ratio of (98/2) to 370 ml of an aqueous solution containing 74 g of silver nitrate 370 ml of an aqueous solution containing potassium and potassium iodide was added over 10 minutes by the controlled double jet method while keeping pAg 7.7. In synchronization with the addition of silver nitrate, 10 ^-6 mol / silver 1 mol of sodium salt of hexachloroiridium was added. Thereafter, 0.3 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added and the pH was adjusted to 5 with NaOH to obtain an average particle size of 36 nm, a coefficient of variation of the projected diameter area of 8%, 100] Cubic silver iodobromide grains having an area ratio of 87% were obtained. This emulsion is agglomerated and precipitated using a gelatin flocculant. After desalting, 0.1 g of phenoxyethanol is added, and 1 L is adjusted to pH 5.9 and pAg 7.5, dried at 36 ° C. for 24 hours, and then silver halide grains 350 g of Emulsion A was obtained.

<Preparation of water-dispersed organic silver salt>
In 4720 ml of pure water, 111.4 g of behenic acid, 83.8 g of arachidic acid, and 54.9 g of stearic acid were dissolved at 80 ° C. Next, 540.2 ml of a 1.5 molar sodium hydroxide aqueous solution was added while stirring at high speed, and 6.9 ml of concentrated nitric acid was added, followed by cooling to 55 ° C. to obtain an organic acid sodium solution. While maintaining the temperature of this organic acid sodium solution at 55 ° C., the silver halide grain emulsion A (containing 0.038 mol of silver) and 420 ml of pure water were added and stirred for 5 minutes. Next, 760.6 ml of a 1 mol silver nitrate solution was added over 2 minutes, and the mixture was further stirred for 20 minutes. At this point, when chemical ripening was performed, the storage chemical sensitizer was added 2 mol / mol silver halide. × 10 ^-5 mol was added and chemical ripening was carried out at 57 ° C for 46 minutes. After completion of aging, water-soluble salts were added by filtration. Thereafter, the filtrate was repeatedly washed with deionized water and filtered until the electric conductivity of the filtrate reached 2 μS / cm, and finally dried to obtain 335 g of a solid content.

[Production of photothermographic image forming materials]
The following layers were sequentially formed on the support provided with the undercoat layer to prepare a sample. In addition, each drying was performed at 45 ° C. for 1 minute.

<Backing layer side coating>
On the back surface side, a backing layer was formed by applying and drying the following amounts.

<Backing layer coating solution>
Inert gelatin 1.8g / m ²
Dye C 1.2 × 10 ⁻⁵ mol / m ²
Activator: N-propyloctylsulfonamidoacetic acid
0.02 g / m ²
Dihexyl sulfosuccinic acid sodium salt 0.02 g / m ²
Cross-linking agent: 1,2-bis (vinylsulfonamide) ethane 0.02 g / m ²
<Coating of backing protective layer>
Inert gelatin 1.1 g / m ²
Cross-linking agent: 1,2-bis (vinylsulfonamide) ethane 0.01 g / m ²
Activator: N-propyl perfluorooctylsulfonamidoacetic acid
0.02 g / m ²
Matting agent (PMMA: average particle size 5 μm) 0.12 g / m ²
<< Coating on the photosensitive layer side >>
On the photosensitive layer side, the following AI layer coating solution, photosensitive layer coating solution and surface protective layer coating solution were applied and dried so as to have the following amounts.

<AI layer coating solution>
Binder: PVB-1 0.4 g / m ²
Dye C 1.2 × 10 ⁻⁵ mol <Photosensitive layer coating solution>
A coating solution was prepared by dissolving the following composition in a methyl ethyl ketone solvent for forming a photosensitive layer. This coating solution was kept at 43 ° C. and dried. An amount of the preparation solution that was 0.86 g / m ² as silver amount was mixed with the binder.

Binder: PVB-1 2.6 g / m ²
Phthalazine compound (compound represented by formula (1)): Table 1
1.2 × 10 ⁻⁴ mol / m ²
Spectral sensitizing dye D 2 × 10 ⁻⁵ mol / m ²
Antifoggant-1: pyridinium hydrobromide perbromide
0.3 mg / m ²
Antifoggant-2: isothiazolone 1.2 mg / m ²
Halomethane compound (compound represented by formula (2)): listed in Table 1
3 × 10 ⁻³ mol / m ²
Reducing agent (compound represented by formula (3)): listed in Table 1 3 × 10 ⁻³ mol / m ²
Cross-linking agent: listed in Table 1 2 × 10 ⁻⁵ mol / m ²
In Table 1, parentheses shown in the column of the compound of the general formula (1), the compound of the general formula (2), the compound of the general formula (3), for example, (Z-2), Z-2 is the total amount, storage An indication without parentheses indicates that a stored compound and an unstored compound are added at a molar ratio of 1: 1.

<Surface protective layer coating solution>
Cellulose acetate butyrate 1.2 g / m ²
4-methylphthalic acid 0.7 g / m ²
Tetrachlorophthalic acid 0.2g / m ²
Tetrachlorophthalic anhydride 0.5g / m ²
Silica matting agent (average particle size 5 μm) 0.5 g / m ²
Surfactant E 0.1 g / m ²

[Evaluation of photographic performance]
After preparing 50 pieces of the above prepared sample in a size of 5 cm × 12 cm, it was divided into two parts, one of which was exposed to a semiconductor laser at 810 nm in output of 60 mW and image-like exposure in an atmosphere of RH 46% at 23 ° C. The sample was exposed to light with a sensitometer and heated at 130 ° C. for 8 seconds after exposure, and the photographic performance of the obtained sample was evaluated (room temperature photographic performance).

  The other is 23 ° C., RH 46%, sealed in an aluminum foil packaging bag under reduced pressure (10 hPa), heat-sealed for 30 days in a constant temperature room at 48 ° C., exposed and developed in the same manner, and measured for fog. This was evaluated as raw preservation (high-temperature photographic performance).

  The laser exposure and development processing were performed in a room adjusted to 23 ° C. ± 1 ° C. and relative humidity of 54% ± 1%.

  The sensitivity and fog were measured with a transmitted light densitometer. The sensitivity was evaluated by the reciprocal of the ratio of the exposure amount giving a density 0.3 higher than the fog density, and expressed by relative evaluation with the sample 101 as a reference (100). The storability after development (image storability) was indicated by the light fog value after the developed sample was left on a shaucusten having a luminance of 10,000 lux for 10 hours.

  From Table 1, it can be seen that by using the stored phthalazine, halomethane compound and reducing agent, the photographic performance (sensitivity and fog characteristics), raw storability and image storability are excellent.

Claims (6)

In a photothermographic image forming material in which a photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a reducing agent and a binder is provided on a support, the photographic agent is a carbon nanotube or carbon provided with a photoresponsive group A photothermographic image-forming material which is stored in a nanohorn and contained in the photosensitive layer. Storage in the carbon nanotube or carbon nanohorn provided with the photoresponsive group of the photochemical agent, after mixing the carbon nanotube or the carbon nanohorn and the compound having the photoresponsive group, ultrasonic treatment, and then adding the photochemical agent, 2. The photothermographic image forming material according to claim 1, wherein the photothermographic image forming material is subjected to high vacuum processing, washing, and light irradiation. The photothermographic image-forming material according to claim 2, wherein the compound having a photoresponsive group has a reactive double bond. The photothermographic image forming material according to any one of claims 1 to 3, wherein the photoresponsive group has a stilbene structure or an azobenzene structure. 5. The photothermographic image forming material according to claim 1, wherein the photographic agent is one selected from a phthalazine compound, a halomethane compound, and a reducing agent. A method for developing a photothermographic image forming material, comprising: irradiating the photothermographic image forming material according to any one of claims 1 to 5 with a laser beam of 400 to 900 nm, followed by heat development.