JP2006178499A - Heat developable photosensitive material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solvent coating system heat developable photosensitive material which suppresses the variation of gradation in raw stock preservation, has high contrast when used for making a printing plate, and hardly develops curl even in the case of a rolled product, and also to provide an aqueous coating system heat developable photosensitive material which suppresses humidity sensitization and the variation of gradation in raw stock preservation, has high contrast when used for making a printing plate, and hardly develops curl even in the case of a rolled product. <P>SOLUTION: A heat developable photosensitive material having organic silver salt grains, photosensitive silver halide grains and a reducing agent on the substrate and containing a hydrophobic binder or a polymer latex in at least one layer is packed with a packing material having an oxygen permeability of ≤50 ml/atm×m<SP>2</SP>×25°C×day or a packing material having a water permeability of ≤10 g/atm×m<SP>2</SP>×25°C×day. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a photothermographic material, and more particularly, a system employing a gradation-coating and high-contrast technology during raw storage of a solvent-coated photothermographic material and a water-based photothermographic material using polymer latex. This solves the problem of softening in the film and the curl problem when it is made into a roll product, and also prevents the moisture sensitization of the water-based photothermographic material using a polymer latex.

  Conventionally, in the fields of printing plate making and medical treatment, waste liquids resulting from wet processing of image forming materials have become a problem in terms of workability. In recent years, reduction of processing waste liquids has been strongly desired from the viewpoint of environmental conservation and space saving. ing. Therefore, there is a need for a technique relating to photothermographic materials for photographic applications that can be efficiently exposed by a laser image setter or a laser imager and can form a clear black image with high resolution. For example, U.S. Pat. Nos. 3,152,904, 3,487,075 and D.I. As described in Morgan, “Dry Silver Photographic Materials” (Handbook of Imaging Materials, Marcel Dekker, Inc., p. 48, 1991), etc. A photothermographic material containing photosensitive silver halide grains, a reducing agent and a binder is known.

  These photothermographic materials form photographic images by heat development processing, and reducible silver sources (organic silver salts), photosensitive silver halides, reducing agents and, if necessary, suppress the color tone of silver. Is usually contained in a dispersed state in an (organic) binder matrix. The photothermographic material is stable at normal temperature, but is developed by heating to a high temperature (for example, 80 ° C. to 140 ° C.) after exposure. By heating, silver is generated through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This redox reaction is promoted by the catalytic action of the latent image generated in the silver halide upon exposure. The silver produced by the reaction of the organic silver salt in the exposed areas provides a black image that contrasts with the unexposed areas and forms an image. This reaction process proceeds without supplying a treatment liquid such as water from the outside.

  In the production of such a photothermographic material, it is often performed that the coating composition is dissolved in an organic solvent such as methyl ethyl ketone or acetone. In the light-sensitive material using these organic solvents, as described in JP-A-6-301140, the amount of residual solvent after coating is made constant, thereby reducing development temperature fluctuations and density fluctuations with time. It is known.

  However, the actual condition is that gradation adjustment during raw storage cannot be prevented by merely adjusting the amount of solvent in the layer.

  For printing plate making, a light-sensitive material capable of obtaining a high-contrast image is required. As described in US Pat. Nos. 5,545,505 and 5,464,738 as the high-contrast technology, a hydrazine derivative is used. However, in a solvent-coated photosensitive material adopting these high contrast techniques, softening is seriously a problem.

  On the other hand, in a photosensitive layer using a polymer latex, it is known that the photothermographic material is applied by aqueous coating. In that case, it is often carried out in a state where a coating composition in which 30% by mass or more of the solvent is water is dispersed or dissolved. These light-sensitive materials are described in JP-A Nos. 10-62899, 10-69023, 10-81067, etc., and 1) a large amount of moisture remains in the light-sensitive material because of the aqueous coating. . 2) Even if the water in the photosensitive material is removed, there is a problem in that water permeates from the outside of the package and the water is retained in the photosensitive material which is easy to become familiar with water. As a result, in the reaction process for forming the black image, the reaction is promoted or the reaction in the non-image area is advanced, so that humidity sensitization is a problem. Moreover, the actual situation is that gradation fluctuations during raw storage cannot be prevented.

  Further, when these photothermographic materials are used as printing plate making materials, the product form is in a roll state, so that the curl is likely to occur.

  The present invention has been made in view of the above circumstances. First, the purpose of the present invention is to suppress gradation fluctuations during raw storage, and when used for printing plate making, it is hard and can be used as a roll product. It is an object of the present invention to provide a photothermographic material of a solvent coating system which is difficult to be curled. Second, it provides a water-based photothermographic material that suppresses gradation variability during humidity sensitization and raw storage, and is hard to use and is not subject to curling as a roll product when used for printing platemaking. There is to do.

The first object of the present invention is achieved by the following items 1 and 2, and the second object of the present invention is achieved by the following items 3 and 4.
1. A photothermographic material having organic silver particles, photosensitive silver halide particles and a reducing agent on a support, and containing a hydrophobic binder in at least one layer, and having an oxygen permeability of 50 ml / atm · m ² · 25 ° C · A photothermographic material, wherein the photothermographic material is packaged with a packaging material of day or less.
2. A photothermographic material having organic silver particles, photosensitive silver halide particles and a reducing agent on a support, and containing a hydrophobic binder in at least one layer, having a moisture permeability of 10 g / atm · m ² · 25 ° C · A photothermographic material, wherein the photothermographic material is packaged with a packaging material of day or less.
3. A photothermographic material having organic silver particles, photosensitive silver halide particles and a reducing agent on a support and containing a polymer latex in at least one layer, and having an oxygen permeability of 50 ml / atm · m ² · 25 ° C · A photothermographic material, wherein the photothermographic material is packaged with a packaging material of day or less.
4). A photothermographic material having organic silver particles, photosensitive silver halide particles and a reducing agent on a support and containing a polymer latex in at least one layer, having a moisture permeability of 10 g / atm · m ² · 25 ° C · A photothermographic material, wherein the photothermographic material is packaged with a packaging material of day or less.

  In other words, the present inventor has wrapped the material with a material having a low oxygen permeability or moisture permeability, so that gradation fluctuations during raw storage, softening in a system employing a high contrast technology, and winding as a roll product. The inventors have found that the problem of moisture sensitization in an aqueous coating system can be solved, and surprisingly, the image storability after processing has been improved and the present invention has been achieved.

  According to the present invention, when the photothermographic material of a solvent coating system and the photothermographic material of an aqueous coating system are subjected to gradation fluctuation during raw storage, softening in a system employing a high contrast technology and a roll product. Thus, the humidity sensitization of the water-based photothermographic material can be suppressed, and in addition, the image storability after processing can be improved.

  Hereinafter, the present invention will be described in detail.

One feature of the photothermographic material of the present invention is that it is packaged with a packaging material having an oxygen permeability of 50 ml / atm · m ² · 25 ° C. · day or less after production. It is preferably 0 to 20 ml / atm · m ² · 25 ° C · day or less.

  Packaging materials that can be used in the present invention include polyethylene (which can be either a high pressure method or a low pressure method), polypropylene (which can be unstretched or stretched), polyvinyl chloride, polyvinyl acetate, nylon (stretched or unstretched), poly Vinylidene chloride, polystyrene, polycarbonate, vinylon, eval, polyethylene terephthalate (PET), other polyesters, hydrochloric acid rubber, acrylonitrile butadiene copolymer, epoxy-phosphate resin (polymers described in JP-A-63-63037, And synthetic resin materials such as polymers described in Japanese Utility Model Laid-Open No. 57-32952, and pulp.

  These are preferably made of a single material, but when used as a film, the film is laminated and adhered, but it may be a coating layer or a single layer.

  Furthermore, it is more preferable to use various gas barrier films, such as using an aluminum foil or an aluminum vapor-deposited synthetic resin between the above synthetic resin films.

  The total film thickness of these laminated films or single layers is preferably 1 to 3000 μm, more preferably 10 to 2000 μm, and still more preferably 50 to 1000 μm.

Another feature of the present invention is that after the photothermographic material is produced, it is packaged with a packaging material having a moisture permeability of 10 g / atm · m ² · 25 ° C. · day or less. Further, it is preferably 0 to 5 g / atm · m ² · 25 ° C. · day or less.

  The moisture permeability of the packaging material mentioned here is the water vapor permeability measured by the measuring method of JIS K7129-1992. The measurement conditions are a test temperature of 40 ° C. and a relative humidity of 90% RH.

  The packaging material satisfying the moisture permeability of the present invention includes polyethylene resin, nylon resin, polypropylene resin, polyethylene terephthalate resin, polyamide resin, ethylene-vinyl alcohol copolymer resin, ethylene-vinyl acetate copolymer system. Examples include resins, acrylonitrile-butadiene copolymer resins, cellophane resins, vinylon resins, vinylidene chloride resins, and the like. Resins such as polypropylene resins and nylon resins may be stretched and further coated with a vinylidene chloride resin. In addition, a polyethylene resin having a low density or a high density can be used.

  Among the above polymer materials, polyethylene (PE), nylon (Ny), nylon (KNy) coated with vinylidene chloride resin (PVDC), unstretched polypropylene (CPP), stretched polypropylene (OPP), and PVDC were coated. Polypropylene (KOP), polyethylene terephthalate (PET), PVDC-coated cellophane (KPT), and a polyethylene-vinyl alcohol copolymer (Eval) are preferably used. By using these resins, a packaging material having suitable mechanical strength and moisture permeability in the present invention can be easily obtained.

In the present invention, a polymer material on which an inorganic compound is vapor-deposited can also be used, and a conventionally known material can be used as such a polymer material. The above-mentioned materials can be used as the polymer material on which the inorganic compound is deposited. Examples of the inorganic compound to be deposited include aluminum, aluminum oxide (Al ₂ O ₃ ), and silicon oxide (SiOx). As a film thickness of a vapor deposition film, the range of 50-1000cm is mentioned. As a vapor deposition method, a known method such as chemical vapor deposition, physical vapor deposition, vapor deposition, or sputtering can be used. When the packaging material of the present invention has a multilayer structure, the film thickness of each layer is appropriately set depending on the desired moisture permeability, mechanical strength, etc., but the overall thickness of the packaging material is 500 μm or less. The production method of the multilayer packaging material is not particularly limited. For example, there are a method in which the resin layer and the resin layer are bonded with an adhesive, a method in which the resin layer and the resin layer are bonded with a molten resin, an extrusion method, or a lamination method. Can be mentioned.

Specific examples of the polymer material that can be used in the present invention include, but are not limited to, the following. In the following, the layer configurations of (outermost part) / (intermediate part) / (contact part with the heat developing material) are respectively shown. For _{example, SiOx PET, Al 2 O 3} PET represents those deposited respectively SiOx, the Al ₂ O ₃ on the PET.
(1) OPP / SiOx PET / CPP
(2) OPP / SiOx PET / PE
(3) OPP / Al ₂ O ₃ PET / CPP
(4) Al ₂ O ₃ PET / Ny / CPP
(5) PET / Al ₂ O ₃ PET / PE
(6) KOP / Ny / PE
(7) PE / KNy / PE
(8) KPT / PE / Ny / PE
(9) OPP / CPP
(10) PET / Eval / PE
(11) OPP / Eval / PE
In each of the above specific examples, the film thickness of each layer may be set so as to obtain a moisture permeability suitable for the scope of the present invention.

In the present invention, it is preferable to use a packaging material that satisfies both the oxygen permeability of 50 ml / atm · m ² · 25 ° C · day or less and the moisture permeability of 10 g / atm · m ² · 25 ° C · day or less. .

  In the present invention, when the photothermographic material contains a hydrazine derivative as a contrast-increasing agent, the effect is fully exhibited.

  As the hydrazine derivative, a compound represented by the following general formula [H] is preferable.

In the formula, A ₀ represents an aliphatic group, aromatic group, heterocyclic group or -G ₀ -D ₀ group, each of which may have a substituent, B ₀ represents a blocking group, and A ₁ and A ₂ represent Both represent a hydrogen atom, or one represents a hydrogen atom and the other represents an acyl group, a sulfonyl group, or an oxalyl group. Here, G ₀ is —CO— group, —COCO— group, —CS— group, —C (═NG ₁ D ₁ ) — group, —SO— group, —SO ₂ — group or —P (O) ( G ₁ D ₁ ) — group, G ₁ represents a simple bond, —O— group, —S— group or —N (D ₁ ) — group, D ₁ represents an aliphatic group, aromatic group, complex When a ring group or a hydrogen atom is represented and a plurality of D ₁ are present in the molecule, they may be the same or different. D ₀ represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, an alkylthio group, or an arylthio group.

In the general formula [H], the aliphatic group represented by A ₀ is preferably one having 1 to 30 carbon atoms, particularly preferably a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, such as methyl Group, ethyl group, t-butyl group, octyl group, cyclohexyl group, benzyl group, and these are further suitable substituents (for example, aryl group, alkoxy group, aryloxy group, alkylthio group, arylthio group, sulfoxy group, A sulfonamide group, a sulfamoyl group, an acylamino group, a ureido group, etc.).

In the general formula [H], the aromatic group represented by A ₀ is preferably a monocyclic or condensed aryl group, such as a benzene ring or a naphthalene ring, and the heterocyclic group represented by A ₀ is A heterocyclic ring containing at least one heteroatom selected from nitrogen, sulfur and oxygen atoms in a single ring or condensed ring is preferred, such as a pyrrolidine ring, imidazole ring, tetrahydrofuran ring, morpholine ring, pyridine ring, pyrimidine ring, quinoline ring, a thiazole ring, a benzothiazole ring, a thiophene ring, a furan ring, and, in -G ₀ -D ₀ group represented by A _0, G ₀ is a -CO- group, -COCO- group, -CS- group, - C (= NG ₁ D ₁ ) — group, —SO— group, —SO ₂ — group or —P (O) (G ₁ D ₁ ) — group is represented. G ₁ represents a simple bond, —O— group, —S— group or —N (D ₁ ) — group, D ₁ represents an aliphatic group, an aromatic group, a heterocyclic group or a hydrogen atom; When there are a plurality of D ₁ , they may be the same or different. D ₀ represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, an alkylthio group, or an arylthio group, and preferred D ₀ is a hydrogen atom, an alkyl group, an alkoxy group, An amino group etc. are mentioned. Aromatic groups A _0, heterocyclic group or -G ₀ -D ₀ group may have a substituent.

Particularly preferred as A ₀ is an aryl group or -G ₀ -D ₀ group.

In the general formula [H], A ₀ preferably contains at least one anti-diffusion group or silver halide adsorption group. The anti-diffusion group is preferably a ballast group commonly used in an immobile photographic additive such as a coupler, and the ballast group is a photographically inert alkyl group, alkenyl group, alkynyl group, alkoxy group, phenyl group, Examples thereof include a phenoxy group and an alkylphenoxy group, and the total number of carbon atoms in the substituent portion is preferably 8 or more.

  In the general formula [H], the silver halide adsorption promoting group includes thiourea, thiourethane group, mercapto group, thioether group, thione group, heterocyclic group, thioamide heterocyclic group, mercapto heterocyclic group, or JP-A-64. And the adsorbing group described in -90439.

In the general formula [H], B ₀ represents a blocking group, preferably a -G ₀ -D ₀ group, and G ₀ represents a -CO- group, a -COCO- group, a -CS- group, -C (= NG ₁ D ₁ ) — group, —SO— group, —SO ₂ — group or —P (O) (G ₁ D ₁ ) — group. Preferred examples of G ₀ include —CO— group and —COCO— group, G ₁ represents a simple bond, —O— group, —S— group or —N (D ₁ ) — group, and D ₁ represents fatty acid. Represents a group, an aromatic group, a heterocyclic group or a hydrogen atom, and when a plurality of D ₁ are present in the molecule, they may be the same or different. D ₀ represents a hydrogen atom, an aliphatic group, an aromatic group, a heterocyclic group, an amino group, an alkoxy group, an aryloxy group, an alkylthio group, or an arylthio group, and preferred D ₀ is a hydrogen atom, an alkyl group, an alkoxy group, An amino group etc. are mentioned. A ₁ and A ₂ are both hydrogen atoms, or one is a hydrogen atom and the other is an acyl group (acetyl group, trifluoroacetyl group, benzoyl group, etc.), sulfonyl group (methanesulfonyl group, toluenesulfonyl group, etc.), or oxalyl group (Etoxalyl group, etc.).

  Next, specific examples of the compound represented by the general formula [H] are shown below, but the present invention is not limited thereto.

  Other hydrazine derivatives that can be preferably used include compounds H-1 to H-29 described in US Pat. No. 5,545,505 column 11 to column 20, US Pat. No. 5,464,738 column 9 to column. 11 to 12.

  These hydrazine derivatives can be synthesized by a known method.

The additive layer of the hydrazine derivative is a photosensitive layer containing a silver halide emulsion and / or a layer adjacent to the photosensitive layer. Further, the optimum amount is not uniform depending on the grain size of the silver halide grains, the halogen composition, the degree of chemical sensitization, the type of the inhibitor, etc., but 10 ⁻⁶ mol to 10 ⁻¹ per mol of silver halide. A molar range of about 10 ⁻⁵ mol to 10 ⁻² mol is preferred.

  The photothermographic material of the present invention includes a hydroxylamine compound, an alkanolamine compound and an ammonium phthalate compound described in US Pat. No. 5,545,505, and a hydroxamic acid described in US Pat. No. 5,545,507. Compounds, N-acyl-hydrazine compounds described in US Pat. No. 5,558,983, acrylonitrile compounds described in US Pat. No. 5,545,515, benzhydrides described in US Pat. No. 5,937,449 It is preferable to add a contrast enhancer such as roll, diphenylphosphine, dialkylpiperidine, or a hydrogen atom donor compound such as alkyl-β-ketoester. Among them, a quaternary onium compound represented by the following general formula (P) and an amino compound represented by the general formula (Na) are preferably used.

In the formula, Q represents a nitrogen atom or a phosphorus atom, R ₁ , R ₂ , R ₃ and R ₄ each represents a hydrogen atom or a substituent, and X ⁻ represents an anion. R _{1 to} R ₄ may be connected to each other to form a ring.

In the general formula [Na], R ₁₁ , R ₁₂ and R ₁₃ are each a hydrogen atom, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, an aryl group, a substituted aryl group, or a saturated or unsaturated group. Represents a heterocycle. R ₁₁ , R ₁₂ and R ₁₃ may form a ring. Particularly preferred are aliphatic tertiary amine compounds. These compounds are preferably those having a non-diffusible group or a silver halide adsorbing group in the molecule. In order to have diffusion resistance, a compound having a molecular weight of 100 or more is preferable, and a molecular weight of 300 or more is more preferable, and examples thereof include those having the same meaning as the diffusion-resistant group in A in the general formula [H]. Preferred examples of the adsorbing group include a heterocyclic ring, a mercapto group, a thioether group, a thione group, and a thiourea group.

  As a more preferred nucleation accelerator than the nucleation accelerator represented by the general formula [Na], a compound represented by the following general formula [Na2] may be mentioned.

In the general formula [Na2], R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom, alkyl group, substituted alkyl group, alkenyl group, substituted alkenyl group, alkynyl group, substituted alkynyl group, aryl group, substituted aryl Represents a group or a saturated or unsaturated heterocycle. These can be connected to each other to form a ring. Also, R ¹ and R ² , R ³ and R ⁴ are not simultaneously hydrogen atoms. X represents an S, Se, or Te atom. L ¹ and L ² each represent a divalent linking group. Specific examples include groups having the following groups or combinations thereof and groups having appropriate substituents (for example, an alkylene group, an alkenylene group, an arylene group, an acylamino group, a sulfonamide group, etc.).

—CH ₂ —, —CH═CH—, —C ₂ H ₄ —, pyridinediyl, —N (Z ₁ ) — (Z ₁ represents a hydrogen atom, an alkyl group or an aryl group), —O—, —S -, - (CO) -, - (SO 2) -, - CH 2 N-.

The linking group represented by L ¹ or L ² preferably contains at least one or more of the following structures in the linking group.

_{- [CH 2 CH 2 O]} -, - [C (CH 3) HCH 2 O] -, - [OC (CH 3) HCH 2 O] -, - [OCH 2 C (OH) HCH 2] -.

  Specific examples of the nucleation accelerator represented by the general formula [Na] or [Na2] are given below.

In the general formula (P), examples of the substituent represented by R _{1 to} R ₄ include an alkyl group (methyl group, ethyl group, propyl group, butyl group, hexyl group, cyclohexyl group, etc.), alkenyl group (allyl group, Butenyl group, etc.), alkynyl group (propargyl group, butynyl group, etc.), aryl group (phenyl group, naphthyl group, etc.), heterocyclic group (piperidinyl group, piperazinyl group, morpholinyl group, pyridyl group, furyl group, thienyl group, tetrahydro group) Furyl group, tetrahydrothienyl group, sulfolanyl group, etc.), amino group and the like.

Examples of the ring that R _{1 to} R ₄ can form together are a piperidine ring, a morpholine ring, a piperazine ring, a quinuclidine ring, a pyridine ring, a pyrrole ring, an imidazole ring, a triazole ring, and a tetrazole ring.

The group represented by R _{1 to} R ₄ may have a substituent such as a hydroxyl group, an alkoxy group, an aryloxy group, a carboxyl group, a sulfo group, an alkyl group, and an aryl group.

R ₁ , R ₂ , R ₃ and R ₄ are preferably a hydrogen atom and an alkyl group.

Examples of the anion represented by X ⁻ include inorganic and organic anions such as halogen ions, sulfate ions, nitrate ions, acetate ions, and p-toluenesulfonate ions.

  More preferred are compounds represented by the following general formula (Pa), (Pb) or (Pc), and compounds represented by the following general formula [T].

In the formula, A ¹ , A ² , A ³ , A ⁴ and A ⁵ represent a nonmetallic atom group for completing a nitrogen-containing heterocycle, which may contain an oxygen atom, a nitrogen atom, or a sulfur atom, and a benzene ring May be condensed. The heterocyclic ring composed of A ¹ , A ² , A ³ , A ⁴ and A ⁵ may have a substituent, and may be the same or different. Substituents include alkyl groups, aryl groups, aralkyl groups, alkenyl groups, alkynyl groups, halogen atoms, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, sulfo groups, carboxy groups, hydroxyl groups, alkoxy groups, aryloxy groups. Amide group, sulfamoyl group, carbamoyl group, ureido group, amino group, sulfonamido group, sulfonyl group, cyano group, nitro group, mercapto group, alkylthio group, arylthio group. Preferred examples of A ¹ , A ² , A ³ , A ⁴ and A ⁵ include 5- to 6-membered rings (rings such as pyridine, imidazole, thiozole, oxazole, pyrazine and pyrimidine), and more preferred. An example is a pyridine ring.

B _P represents a divalent linking group, and m represents 0 or 1. Examples of the divalent linking group include an alkylene group, an arylene group, an alkenylene group, —SO ₂ —, —SO—, —O—, —S—, —CO—, —N (R ⁶ ) — (R ⁶ represents an alkyl group). Represents a group, an aryl group, or a hydrogen atom) alone or in combination. Preferably, there can be mentioned an alkylene group, an alkenylene group as B _p.

R ¹ , R ² and R ⁵ each represent an alkyl group having 1 to 20 carbon atoms. R ¹ and R ² may be the same or different. The alkyl group represents a substituted or unsubstituted alkyl group, and the substituent is the same as the substituents exemplified as the substituents for A ¹ , A ² , A ³ , A ⁴ and A ⁵ .

Preferable examples of R ¹ , R ² and R ⁵ are each an alkyl group having 4 to 10 carbon atoms. More preferred examples include substituted or unsubstituted aryl-substituted alkyl groups.

X _p ⁻ represents a counter ion necessary for balancing the charge of the whole molecule, for example, chlorine ion, bromine ion, iodine ion, nitrate ion, sulfate ion, p-toluenesulfonate, oxalate and the like. n _p represents the number of counter ions necessary to balance the charge of the whole molecule, and n _p is 0 in the case of an inner salt.

Substituents R ₅ , R ₆ and R ₇ of the phenyl group of the triphenyltetrazolium compound represented by the above general formula [T] are hydrogen atoms or those having a negative Hammett sigma value (σP) indicating electron withdrawing degree. preferable.

  Hammett's sigma value in the phenyl group is described in many literatures such as C.I. in Journal of Medical Chemistry 20, 304, 1977. Examples of groups having a particularly preferable negative sigma value that can be found in reports such as Hansh (C. Hansch) include, for example, a methyl group (σP = −0.17 in each case σP value), an ethyl group (− 0.15), cyclopropyl group (−0.21), n-propyl group (−0.13), iso-propyl group (−0.15), cyclobutyl group (−0.15), n-butyl group (−0.16), iso-butyl group (−0.20), n-pentyl group (−0.15), cyclohexyl group (−0.22), amino group (−0.66), acetylamino group (−0.15), hydroxyl group (−0.37), methoxy group (−0.27), ethoxy group (−0.24), propoxy group (−0.25), butoxy group (−0.32) ), A pentoxy group (−0.34) and the like. Is also useful as a substituent for compounds of general formula [T].

n represents 1 or 2, and examples of the anion represented by X _T ^n- include halogen ions such as chloride ion, bromide ion and iodide ion, acid radicals of inorganic acids such as nitric acid, sulfuric acid and perchloric acid, Acid radicals of organic acids such as sulfonic acids and carboxylic acids, anionic activators, specifically lower alkylbenzene sulfonate anions such as p-toluenesulfonate anion, higher alkylbenzene sulfonate anions such as p-dodecylbenzenesulfonate anion , Higher alkyl sulfate anions such as lauryl sulfate anion, boric acid anions such as tetraphenylboron, dialkylsulfosuccinate anions such as di-2-ethylhexylsulfosuccinate anion, higher fatty acid anions such as cetylpolyethenoxysulfate anion , Polyacrylic acid It can be mentioned, such as those with an acid radical to the polymer of the emissions, and the like.

  Specific examples of the quaternary onium compound are listed below, but are not limited thereto.

  The quaternary onium compound can be easily synthesized according to a known method. For example, the tetrazolium compound can be synthesized from Chemical Reviews 55 p. The method described in 335-483 can be referred to.

The addition amount of these quaternary onium compounds is about 1 × 10 ⁻⁸ to 1 mol, preferably 1 × 10 ⁻⁷ to 1 × 10 ⁻¹ mol, per mol of silver halide. These can be added to the light-sensitive material at any time from formation of silver halide grains to coating.

  Quaternary onium compounds and amino compounds may be used alone or in combination of two or more. Further, it may be added to any layer in the constituent layers of the photosensitive material, but it is preferably added to at least one constituent layer on the side having the photosensitive layer, and further to the photosensitive layer and / or its adjacent layer.

  In the photothermographic material of the present invention, the smooth surface value on the outermost surface on the side having the photosensitive layer is 40 mmHg (≈532 kPa) or less, or the smoother value on the outermost surface opposite to the side having the photosensitive layer is 80 mmHg (≈ 1064 kPa) or more is preferable.

  Here, the smoother value is defined by the value of the suction pressure measured under the following conditions. The measurement is performed with a smoother SM-6B manufactured by Toei Electric Industry Co., Ltd. A high value corresponds to a large surface irregularity and / or a large number of irregularities. Before measurement, humidity is adjusted for 2 hours at 23 ° C. and 48% relative humidity, and measurement is performed in the same environment using the above-described apparatus.

  In the present invention, the smoother value of the outermost surface on the side having the photosensitive layer is preferably in the range of 0.1 mmHg (≈1.33 kPa) to 35 mmHg (≈465.5 kPa), more preferably 1 mmHg (≈13.3 kPa). ) To 32 mmHg (≈425.6 kPa).

  The smoother value of the outermost surface opposite to the side having the photosensitive layer is preferably in the range of 85 mmHg (≈1130.5 kPa) to 400 mmHg (≈5320 kPa), more preferably 90 mmHg (≈1197 kPa) to 250 mmHg (≈3325 kPa). Range.

  The smoother value is a combination of the amount of binder such as polyvinyl butyral, cellulose acetate butyrate, polyester or polymer latex in the constituent layer of the light-sensitive material, the particle size, shape, addition amount, etc. of the matting agent, hardener or plasticizer. It depends on the kind and amount of the compound that changes the physical properties of the binder such as the agent, the coating and drying conditions, and the like. In the present invention, the smoother value is set to an optimum range by combining these techniques. By setting it in this range, it is possible to make it easier to stick the roll in a roll form.

  In the present invention, the organic silver salt is a reducible silver source, and silver salts of organic acids and heteroorganic acids containing a reducible silver ion source, particularly long chains (10-30, preferably 15-25 carbon atoms). Number) aliphatic carboxylic acid and nitrogen-containing heterocycle. Also useful are organic or inorganic silver salt complexes in which the ligand has a total stability constant for silver ions of 4.0-10.0. Examples of suitable 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 Silver carboxyalkylthiourea salts (eg, 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc.); aldehyde and hydroxy substitution Polymers with aromatic carboxylic acids (eg aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.), hydroxy-substituted acids (eg salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid)) Silver complex of reaction product, silver salt or complex of thiones (for example, 3- (2-carboxyethyl) -4-hydroxymethyl-4- (thiazoline-2-thione and 3-carboxymethyl-4-thiazoline-2-thione)), imidazole, pyrazole, urazole, 1,2,4 A complex or salt of nitrogen acid and silver selected from thiazole and 1H-tetrazole, 3-amino-5-benzylthio-1,2,4-triazole and benzotriazole; silver such as saccharin and 5-chlorosalicylaldoxime Salts; and silver salts of mercaptides. Preferred silver sources are silver behenate, arachidic acid and / or stearic acid.

  The organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound that forms a complex with silver. As described in Japanese Patent Application Laid-Open No. 9-127643, a normal mixing method, a reverse mixing method, and a simultaneous mixing method are used. A controlled double jet method or the like is preferably used. For example, an alkali metal salt (eg, sodium hydroxide, potassium hydroxide, etc.) is added to an organic acid to produce an organic acid alkali metal salt soap (eg, sodium behenate, sodium arachidate), and then a controlled double jet. By adding the soap and silver nitrate, an organic silver salt crystal is prepared. At that time, silver halide grains may be mixed.

  The silver halide grains in the present invention function as an optical sensor. In the present invention, in order to keep the white turbidity after image formation low and to obtain good image quality, it is preferable that the average particle size is small, and the average particle size is 0.1 μm or less, more preferably 0.01 μm to 0.00. 1 μm, particularly 0.02 μm to 0.08 μm is preferable. The grain size here refers to 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 when a sphere equivalent to the volume of silver halide grains is considered. The silver halide is preferably monodispersed. The monodispersion here means that the monodispersity obtained by the following formula is 40% or less. The particles are more preferably 30% or less, particularly preferably 0.1% or more and 20% or less.

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

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

  Another preferred silver halide shape is a tabular grain. The tabular grains referred to here are those having an aspect ratio = r / h of 3 or more when the square root of the projected area is the grain size r μm and the thickness in the vertical direction is h μm. Among them, the aspect ratio is preferably 3 or more and 50 or less. The particle size is preferably 0.1 μm or less, more preferably 0.01 μm to 0.08 μm. These are described in US Pat. Nos. 5,264,337, 5,314,798, 5,320,958, etc., and the desired tabular grains can be easily obtained. When these tabular grains are used in the present invention, the sharpness of the image is further improved.

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

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

  The photosensitive silver halide grains can be desalted by washing with water by a method known in the art such as a noodle method or a flocculation method, but in the present invention, it may or may not be desalted.

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

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

  The photothermographic material of the present invention incorporates a reducing agent. Examples of suitable reducing agents are described in US Pat. Nos. 3,770,448, 3,773,512, 3,593,863, and Research Disclosure Nos. 17029 and 29963. There is. Aminohydroxycycloalkenone compounds (eg, 2-hydroxypiperidino-2-cyclohexenone); aminoreductones esters (eg, piperidinohexose reductone monoacetate) as precursors of reducing agents; N— Hydroxyurea derivatives (eg, Np-methylphenyl-N-hydroxyurea); hydrazones of aldehydes or ketones (eg, anthracene aldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (Eg hydroquinone, t-butyl-hydroquinone, isopropylhydroquinone and (2,5-dihydroxy-phenyl) methylsulfone); sulfhydroxamic acids (eg benzenesulfhydroxamic acid Sulfonamide anilines (eg, 4- (N-methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (eg, 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone); tetrahydroquinoxaline (Eg, 1,2,3,4-tetrahydroquinoxaline); amidoxins; azines (eg, combinations of aliphatic carboxylic acid aryl hydrazides and ascorbic acid); combinations of polyhydroxybenzene and hydroxylamine, reductones 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; Phenol 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, 4,5-ethylidene-bis (2-t-butyl-6-methyl) phenol), UV-sensitive ascorbic acid derivatives and 3-pyrazolidones. Of these, particularly preferred reducing agents are hindered phenols. Examples of the hindered phenols include compounds represented by the following general formula (A).

In the formula, R represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms (for example, —C ₄ H ₉ , 2,4,4-trimethylpentyl), and R ′ and R ″ represent 1 to 1 carbon atoms. Represents an alkyl group of 5 (for example, methyl, ethyl, t-butyl).

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

The amount of the reducing agent including the compound represented by the general formula (A) is preferably 1 × 10 ⁻² to 10 mol, particularly 1 × 10 ^{−2 to} 1.5 mol, per 1 mol of silver.

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

  When using polymer latex, dissolve it in a suitable water-miscible organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethyl sulfoxide, methyl cellosolve, etc. Can be used.

  Dissolve mechanically by emulsifying and dispersing by using well-known emulsification and dispersion methods using dibutyl phthalate, tricresyl phosphate, oils such as glyceryl triacetate or diethyl phthalate, and auxiliary solvents such as ethyl acetate and cyclohexane. Can be used. Alternatively, it can be used by being dispersed in water by ball mill, colloid mill, zirconia bead dispersion or ultrasonic waves by a method known as a solid dispersion method.

  The binder in the case of using the polymer latex is arbitrarily selected from well-known natural or synthetic resins such as gelatin, polyvinyl acetal, polyvinyl chloride, polyvinyl acetate, cellulose acetate, polyolefin, polyester, polystyrene, polyacrylonitrile, and polycarbonate. Can choose. Of course, copolymers and terpolymers are also included. Preferred polymers are polyvinyl butyral, butyl ethyl cellulose, methacrylate copolymers, maleic anhydride ester copolymers, polystyrene and butadiene-styrene copolymers. If necessary, two or more of these polymers can be used in combination.

  The “polymer latex” here refers to a water-insoluble hydrophobic polymer dispersed as fine particles in a water-soluble dispersion medium. As the dispersion state, the polymer is emulsified in a dispersion medium, the emulsion is polymerized, the micelle is dispersed, or the polymer molecule has a partially hydrophilic structure and the molecular chain itself is molecularly dispersed. Anything may be used. "Synthetic Resin Emulsions (Edited by Taira Okuda, Hiroshi Inagaki, Published by Polymer Publishing Company (1978))", "Application of Synthetic Latex (Takaaki Sugimura, Akio Kataoka, Junichi Suzuki, Keiji Kasahara, Published by Polymer Publishing Company (1993)) ) ”,“ Chemicals of Synthetic Latex (Souichi Muroi, published by Kobunshi Shuppankai (1970)) ”and the like can also be used. The average particle size of the dispersed particles is preferably 1 to 50000 nm, more preferably about 5 to 1000 nm. The particle size distribution of the dispersed particles is not particularly limited, and may have a wide particle size distribution or a monodispersed particle size distribution, and may be a so-called core / shell type latex.

  Examples of the polymer species used in the polymer latex include acrylic resins, vinyl acetate resins, polyester resins, polyurethane resins, rubber resins, vinyl chloride resins, vinylidene chloride resins, polyolefin resins, and copolymers thereof. The polymer may be a so-called homopolymer obtained by polymerizing a single monomer, or a copolymer obtained by polymerizing two or more monomers. In the case of a copolymer, it may be a random copolymer or a block copolymer.

  Specific examples of polymer latexes include methyl methacrylate / ethyl acrylate / methacrylic acid copolymer latex, methyl methacrylate / 2 ethylhexyl acrylate / styrene / acrylic acid copolymer latex, styrene / butadiene / acrylic acid copolymer latex, styrene / butadiene / divinyl. Examples include latex of benzene / methacrylic acid copolymer, latex of methyl methacrylate / vinyl chloride / acrylic acid copolymer, latex of vinylidene chloride / ethyl acrylate / acrylonitrile / methacrylic acid copolymer, and the like. Moreover, such a polymer is also marketed and the following polymers can be utilized. For example, as an example of an acrylic resin, Sebian A-4635, 46583, 4601 (manufactured by Daicel Chemical Industries, Ltd.), Nipol Lx811, 814, 821, 820, 857 (manufactured by Nippon Zeon Co., Ltd.), etc. Are FINETEX ES650, 611, 675, 850 (manufactured by Dainippon Ink Chemical Co., Ltd.), WD-size, WMS (manufactured by Eastman Chemical), etc., and HYDRAN AP10, 20, 30, 40 (and above) as polyurethane resins Daicel Ink Chemical Co., Ltd.) and other rubber-based resins include LACSTAR 7310K, 3307B, 4700H, 7132C (manufactured by Dainippon Ink Chemical Co., Ltd.), Nipol Lx416, 410, 438C, 2507 (manufactured by Nippon Zeon Co., Ltd.) )), Etc. G351 and G576 (manufactured by Nippon Zeon Co., Ltd.) as fats, L502 and L513 (manufactured by Asahi Kasei Kogyo Co., Ltd.) as vinylidene chloride resins, and Chemipearl S120 and SA100 (manufactured by Mitsui Petrochemical Co., Ltd.) as olefin resins Product)). These polymers may be used alone or as a mixture of two or more as necessary.

  The molecular weight of the polymer is preferably 5,000 to 1,000,000, more preferably about 10,000 to 100,000 in terms of number average molecular weight.

  The polymer latex is preferably used as 50% by mass or more of the total binder, and more preferably 70% by mass or more.

  The minimum film-forming temperature (MFT) of the polymer latex is −30 ° C. to 90 ° C., more preferably about 0 ° C. to 70 ° C. A film-forming auxiliary may be added to control the minimum film-forming temperature. A film-forming aid, also called a plasticizer, is an organic compound (usually an organic solvent) that lowers the minimum film-forming temperature of polymer latex. )"It is described in.

  The polymer latex polymer used in the present invention preferably has an equilibrium water content of 2% by mass or less, more preferably 1% by mass or less at 25 ° C. and 60% RH.

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

In the present invention, in the solvent coating system, the binder amount of the photosensitive layer is preferably 1.5 to 10 g / m ² in order to increase the speed of thermal development. More preferably, it is 1.7-8 g / m < ² >. If it is less than 1.5 g / m ² , the density of the unexposed area is significantly increased and may not be used.

The total amount of binder in the aqueous coating photosensitive layer is preferably 0.2 to 30 g / m ² , more preferably 1 to 15 g / m ² . Further, a crosslinking agent for crosslinking, a surfactant for improving coating properties, and the like may be added.

  In the present invention, it is preferable to contain a matting agent on the photosensitive layer side, and in order to prevent scratches on the image after heat development, it is preferable to dispose the matting agent on the surface of the photosensitive material. It is preferable to contain 0.5-30% by mass ratio with respect to the total binder on the photosensitive layer side. Further, when a non-photosensitive layer is provided on the opposite side of the photosensitive layer with the support interposed between them, it is preferable to contain a matting agent in at least one layer on the non-photosensitive layer side, in order to prevent slipping of the photosensitive material and adhesion of fingerprints. In addition, it is preferable to dispose a matting agent on the surface of the photosensitive material, and it is preferable to contain the matting agent in a mass ratio of 0.5 to 40% with respect to all binders on the layer opposite to the photosensitive layer side.

  The shape of the matting agent may be either a regular shape or an irregular shape, but is preferably a regular shape, and a spherical shape is preferably used.

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

  These non-photosensitive layers preferably contain the above binder and matting agent, and may further contain a polysiloxane compound, a sliding agent such as wax or liquid paraffin.

  In the photothermographic material of the present invention, various surfactants are used as coating aids. Among them, a fluorosurfactant is preferably used in order to improve charging characteristics or prevent spotted coating failure.

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

  Examples of suitable toning agents for use in the present invention are disclosed in Research Disclosure No. 17029.

  The heat development material of the present invention contains a mercapto compound, a disulfide compound, and a thione compound for controlling development by suppressing or accelerating development, improving spectral sensitization efficiency, and improving storage stability before and after development. Can be made.

  The photothermographic material of the present invention may contain an antifogging agent.

  Various additives may be added to any of the photosensitive layer, the non-photosensitive layer, and other forming layers. In the photothermographic material of the present invention, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, a coating aid and the like may be used. As these additives and the other additives described above, compounds described in Research Disclosure Item 17029 (June 1978, p. 9-15) can be preferably used.

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

  Among them, preferable supports include polyethylene terephthalate (hereinafter abbreviated as PET) and a plastic (hereinafter abbreviated as SPS) support including a styrene polymer having a syndiotactic structure. The thickness of the support is about 50 to 300 μm, preferably 70 to 180 μm, and more preferably 110 to 170 μm.

  A plastic support that has been heat-treated to improve dimensional stability and distortion due to heat development can also be used. Examples of the plastic to be used include the plastics described above. The heat treatment of the support is a temperature higher than the glass transition point of the support by 30 ° C. or more, preferably 35 ° C. or more, after the film formation of these supports and before the image forming layer is applied, More preferably, heating is performed at a temperature higher by 40 ° C. or more. However, the effect of the present invention cannot be obtained by heating at a temperature exceeding the melting point of the support.

  A known method can be used for the film forming method and the undercoating method for the support according to the present invention. Preferably, the method described in paragraphs [0030] to [0070] of JP-A-9-50094 is used. Is to use.

  When packaging by applying the packaging material according to the present invention to a photothermographic material using the above-mentioned support, distortion during heat development is further improved, or dimensional stability during storage under high temperature and high humidity conditions is improved. There are excellent advantages.

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

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the aspect of this invention is not limited to this.
Example 1
(Preparation of undercoated PET support)
A commercially available biaxially stretched heat-fixed PET film with a thickness of 100 μm is subjected to a corona discharge treatment of 8 w / m ² · min, and the following undercoat coating liquid a-1 is applied to one side with a dry film thickness of 0.8 μm. The undercoat layer A-1 was coated and dried to form an undercoat layer A-1, and on the opposite side, the following antistatic coating solution b-1 was applied so that the dry film thickness was 0.8 μm. It was made to dry and it was set as the antistatic process undercoat layer B-1.
<< Undercoat coating liquid a-1 >>
Butyl acrylate (30% by mass)
t-Butyl acrylate (20% by mass)
Styrene (25% by mass)
2-Hydroxyethyl acrylate (25% by mass)
270 g of copolymer latex liquid (solid content 30%)
(C-1) 0.6g
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 >>
SnO ₂ / Sb (9/1 mass ratio, average particle size 0.18 μm)
Amount to become 200 mg / m ² Butyl acrylate (30% by mass)
Styrene (20% by mass)
Glycidyl acrylate (40% by mass)
270 g of copolymer latex liquid (solid content 30%)
(C-1) 0.6g
Hexamethylene-1,6-bis (ethylene urea) 0.8g
Finish to 1 liter with water Subsequently, the upper surface of the undercoat layer A-1 and the undercoat layer B-1 is subjected to a corona discharge of 8 w / m ² · min. The undercoat layer coating liquid a-2 is used as an undercoat layer A-2 so that the dry film thickness becomes 0.1 μm, and the following undercoat upper layer coating liquid b-2 is applied over the undercoat layer B-1 with a dry film thickness of 0. It was coated as an undercoating upper layer B-2 having an antistatic function so as to be 8 μm.
<< Undercoating upper layer coating liquid a-2 >>
Mass to become gelatin 0.4g / m ² (C-1) 0.2g
(C-2) 0.2g
(C-3) 0.1 g
Silica particles (average particle size 3μm) 0.1g
Finish to 1 liter with water << Undercoating upper layer coating liquid b-2 >>
(C-4) 60g
Latex liquid containing 20% of (C-5) (solid content 20%) 80g
Ammonium sulfate 0.5g
(C-6) 12g
Polyethylene glycol (weight average molecular weight 600) 6g
Finish to 1 liter with water

(Heat treatment of support)
The undercoated support was placed in a heat treatment zone having a total length of 150 m set at 200 ° C. and conveyed at a tension of 4 kg / cm ² and a conveyance speed of 10 m / min. Thereafter, the film was passed through a zone of 40 ° C. for 20 seconds and wound with a winding tension of 9 kg / cm ² .
(Preparation of 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 35 ° C. and pH to 3.0, 370 ml of an aqueous solution containing 74 g of silver nitrate and a molar ratio of (60/38/2) An aqueous solution containing sodium chloride, potassium bromide and potassium iodide and [Ir (NO) Cl ₅ ] salt at 1 × 10 ⁻⁶ mol per mol of silver and rhodium chloride at 1 × 10 ⁻⁶ mol per mol of silver And added by the controlled double jet method while maintaining pAg 7.7. Thereafter, 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added and the pH was adjusted to 8 with NaOH to achieve pAg6.5 to perform reduction sensitization, and the average particle size was 0.06 μm. Cubic silver iodobromide grains having a dispersion coefficient of 10% and a projected diameter area variation coefficient of 8% and a [100] face ratio of 87% were obtained. The emulsion was coagulated and settled using a gelatin flocculant for desalting.
(Preparation of Na behenate solution)
In 945 ml of pure water, 32.4 g of behenic acid, 9.9 g of arachidic acid, and 5.6 g of stearic acid were dissolved at 90 ° C. Next, 98 ml of a 1.5 M aqueous sodium hydroxide solution was added while stirring at high speed. Next, 0.93 ml of concentrated nitric acid was added, and then cooled to 55 ° C. and stirred for 30 minutes to obtain a sodium behenate solution.
(Preparation of preform emulsion of silver behenate and silver halide A)
After adding 15.1 g of the above silver halide emulsion A to the above sodium behenate solution and adjusting to pH 8.1 with sodium hydroxide solution, 147 ml of 1M silver nitrate solution was added over 7 minutes, and the mixture was further stirred for 20 minutes. Water soluble salts were removed by filtration. The resulting silver behenate was a grain having an average grain size of 0.8 μm and a monodispersity of 8%. After forming the floc of the dispersion, the water was removed, and after further washing with water 6 times and removing the water, drying was performed.
(Preparation of photosensitive emulsion)
The resulting preform emulsion was divided, 544 g of a methyl ethyl ketone solution (17% by mass) of polyvinyl butyral (average molecular weight 3000) and 107 g of toluene were gradually added and mixed, and then a 0.5 mm size ZrO ₂ bead mill was used. Dispersion was performed at 4000 psi at 30 ° C. for 10 minutes with a media disperser.

The following layers were simultaneously coated on the support to prepare a sample. The drying was performed at 60 ° C. for 15 minutes.
(Back side application)
A liquid having the following composition was applied on the B-1 layer of the support.

Cellulose acetate butyrate 15ml / m ²
(10% methyl ethyl ketone solution)
Dye-A 7 mg / m ²
Dye-B 7 mg / m ²
Matting agent: Monodispersity 15% Average particle size 8 μm Monodispersed silica
90 mg / m ²
C ₈ F ₁₇ (CH ₂ CH ₂ O) ₁₂ C ₈ F ₁₇ 50 mg / m ²
_{C 9 F 17 -C 6 H 4} -SO 3 Na 10mg / m 2

(Photosensitive layer side coating)
Photosensitive layer 1: A solution having the following composition was coated on the A-1 layer of the support so that the amount of coated silver was 2.4 g / m ² .

Preform emulsion 240g
Sensitizing dye (0.1% methanol solution) 1.7ml
Pyridinium promide perbromide (6% methanol solution) 3 ml
Calcium bromide (0.1% methanol solution) 1.7ml
Oxidant (10% methanol solution) 1.2ml
9.2 ml of 2--4-chlorobenzoylbenzoic acid (12% methanol solution)
11 ml of 2-mercaptobenzimidazole (1% methanol solution)
17 ml of tribromomethylsulfoquinoline (5% methanol solution)
Hydrazine derivative H-26 0.4g
High contrast accelerator P-51 0.3 g
Phthalazine 0.6g
4-methylphthalic acid 0.25g
Tetrachlorophthalic acid 0.2g
0.1 g of calcium carbonate with an average particle size of 3 μm
A-4 (20% methanol solution) 20.5 ml
Isocyanate compound 0.5g
(Desmodur N3300, manufactured by Mobay)

  Surface protective layer: A solution having the following composition was applied simultaneously on the photosensitive layer.

Acetone 5ml / m ²
Methyl ethyl ketone 21ml / m ²
Cellulose acetate butyrate 2.3 g / m ²
Methanol 7ml / m ²
Phthalazine 250mg / m ²
Developer (20% methanol solution) 10ml / m ²
Matting agent: 10% monodispersion average particle size 4 μm monodispersed silica
5 mg / m ²
CH ₂ = CHSO ₂ CH ₂ CH ₂ OCH ₂ CH ₂ SO ₂ CH = CH ₂
35 mg / m ²
Fluorosurfactant C ₁₂ F ₂₅ (CH ₂ CH ₂ O) ₁₀ C ₁₂ F ₂₅
10 mg / m ²
_{C 8 F 17 -C 6 H 4} -SO 3 Na 10mg / m 2
The smoother value on the surface on the photosensitive layer side was 25 mmHg (≈332.5 kPa), and the smoother value on the surface on the backing side was 200 mmHg (≈2660 kPa). The smooth star value was measured by adjusting the smooth star value on the surface of the photosensitive layer in the same environment for 2 hours at 23 ° C. and 48% RH while leaving the sample unexposed. Measured by 6B.

  After removing the binder using the sample after the coating film was formed, and measured by observation with an electron microscope by a replica method, the organic silver particles had a major axis diameter of 0.5 ± 0.05 μm and a minor axis diameter of 0.4. The tabular grains having a thickness of ± 0.05 μm and a thickness of 0.01 μm were grains having a monodispersity of 5%, which is 90% of all organic silver grains.

The photothermographic material prepared above was cut into a length of 30 m and a length of 50 m in a dark room, and wound around a core made of cardboard having an inner diameter of 10 cm to prepare a roll-shaped sample. Furthermore, the sample produced in the dark room was wound with a packaging material of 60 cm × 2 m made of the material shown in Table 1.
<Forced deterioration test>
The packaged photothermographic material sample prepared above was heated for 5 days at 40 ° C. and 80% RH as the forced deterioration condition.
<< Exposure and development process >>
Then, using a Dotex 2dry made by Cytex Corp., an image setter equipped with a 780 nm semiconductor laser, the halftone dots are exposed at 300 lines in 5% increments, and heat development is performed at 120 ° C. for 25 seconds. Went. At that time, exposure and development were performed in a room adjusted to 23 ° C. and 50% RH.
《Crump test》
The sample subjected to the above-mentioned forced deterioration was cut into a width of 20 cm and a length of 60 cm, and the humidity was adjusted to 23 ° C. and 50% RH. Was measured. It can be seen that the larger the bounce, the stronger the roll.
《Transportability test》
100 pieces of the sample exposure and thermal development treatment subjected to the above-mentioned forced deterioration were continuously performed. At that time, the number of sheets having a conveyance failure was counted. A sample with a strong curl tends to cause a conveyance failure.
<Evaluation of softening>
The dot image quality was visually observed with a magnifier of 100% of 5% halftone dots of the sample subjected to the above-mentioned forced deterioration after exposure and heat development. The one with no fringe was set to 5, and the rank was lowered as the fringe came out. Less than 3 ranks are not practical.
<Evaluation of density change after heat development>
The sample subjected to the above-mentioned forced deterioration was subjected to exposure and heat development, and was divided into two, and one was put into a thermostat of 50 ° C. and 60% RH for evaluation over time for 5 days. It was measured with a densitometer how much the concentration changed after the thermo was charged when the concentration was 2.5 before the thermo was charged.

  The results are shown in Table 2.

Example 2
A photothermographic material was prepared in the same manner as in Example 1 except that the silver halide emulsion was changed to B below, the hydrazine derivative of the photosensitive layer was changed to H-14, and the contrast accelerator was changed to P-42. The produced photothermographic material was cut into a length of 30 m and a length of 50 m in a dark room, and wound around a core made of cardboard having an inner diameter of 10 cm to produce a roll-shaped sample. Further, a sample prepared in a dark room was tightly wound with a packaging material of 60 cm × 2 m made of the material shown in Table 3. Table 4 shows the results evaluated in the same manner as in Example 1.
(Preparation of silver halide emulsion B)
Using the simultaneous mixing method, silver chlorobromide core grains having an average thickness of 0.01 μm and an average diameter of 0.05 μm made of silver chloride 70 mol% and the rest silver bromide were prepared. At the time of mixing the core particles, 8 × 10 ⁻⁸ mol of K ₃ RuCl ₆ was added per mol of silver. A shell was attached to the core particles using a simultaneous mixing method. At that time, K ₂ IrCl ₆ was added in an amount of 3 × 10 ⁻⁷ mol per mol of silver. The obtained emulsion was a silver chloroiodobromide (90 mol% of silver chloride) having an average thickness of 0.02 μm and an average diameter of 0.09 μm of a core / shell monodisperse (variation coefficient 10%) (100) plane as the main plane. Tabular grain emulsion comprising 0.2 mol% of silver iodobromide, the rest being silver bromide. Subsequently, desalting was carried out using modified gelatin G-8 described in JP-A-2-280139, page 287 (3) (in which the amino group in gelatin was substituted with phenylcarbamyl).

The EAg after desalting was 190 mV at 50 ° C. 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added at 1 × 10 ⁻³ mol per mol of silver, and potassium bromide and citric acid were added to adjust the pH to 5.6 and EAg of 123 mV. Then, 2 × 10 ⁻⁵ mol of chloroauric acid was added, then 3 × 10 ⁻⁶ mol of inorganic sulfur was added, and chemical ripening was performed at a temperature of 60 ° C. until the maximum sensitivity was obtained. After completion of ripening, 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene is 2 × 10 ⁻³ mol per mol of silver, and 3 × 10 ⁻⁴ mol of 1-phenyl-5-mercaptotetrazole. And gelatin was added.

Example 3
(Preparation of silver halide grains C)
After dissolving 22 g of phthalated gelatin and 30 mg of potassium bromide in 700 ml of water and adjusting the pH to 5.0 at a temperature of 40 ° C., 159 ml of an aqueous solution containing 18.6 g of silver nitrate and an aqueous solution containing potassium bromide were added to pAg 7.7. Was added over 10 minutes by the control double jet method. An aqueous solution containing 8 × 10 ⁻⁶ mol / L of K ₃ [IrCl ₆ ] ³⁻ and 1 mol / L of potassium bromide was added over 30 minutes by the control double jet method while maintaining pAg 7.7. Thereafter, the pH was adjusted to 5.9 and pAg 8.0 (cubic particles having an average particle size of 0.07 μm, a variation coefficient of projected area diameter of 8%, and a (100) area ratio of 86%).

The silver halide grains C were heated to 60 ° C. and 8.5 × 10 ⁻⁵ mol of sodium thiosulfate, 1.1 × 10 ⁻⁵ mol of 2,3,4,5, 6-Pentafluorophenyl diphenylsulfine selenide, 3.3 × 10 ⁻⁶ mol of chloroauric acid, 2.3 × 10 ⁻⁴ mol of thiocyanic acid were added and ripened for 120 minutes. Thereafter, the temperature was set to 50 ° C., 8 × 10 ⁻⁴ mol of sensitizing dye was added with stirring, 3.5 × 10 ⁻² mol of potassium iodide was further added, and the mixture was stirred for 30 minutes. To complete the preparation of silver halide grains.
(Preparation of organic acid silver microcrystal dispersion)
40 g of behenic acid, 7.3 g of stearic acid and 500 ml of distilled water were mixed at 90 ° C. for 15 minutes, 187 ml of 1N NaOH aqueous solution was added over 15 minutes with vigorous stirring, and 61 ml of 1N nitric acid aqueous solution was added to 50 ° C. The temperature dropped. Next, 124 ml of 1N-silver nitrate aqueous solution was added and stirred as it was for 30 minutes. Thereafter, the solid content was filtered by suction filtration, and the solid content was washed with water until the filtrate had a conductivity of 30 μS / cm. The solid content thus obtained was handled as a wet cake without being dried, and 12 g of polyvinyl alcohol and 150 ml of water were added to the wet cake corresponding to 34.8 g of the dry solid content and mixed well to obtain a slurry. Prepare 840 g of zirconia beads having an average diameter of 0.5 mm, put them in a vessel together with the slurry, and disperse them for 5 hours with a disperser (1/4 G-sand grinder mill: manufactured by IMEX Co., Ltd.). An organic acid silver crystallite dispersion of .5 μm was obtained.
(Preparation of raw material fine particle dispersion)
Solid fine particle dispersions of tetrachlorophthalic acid, 4-methylphthalic acid, 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, phthalazine, and tribromomethylsulfonylbenzene Prepared.

  To tetrachlorophthalic acid, 0.81 g of hydroxypropylcellulose and 94.2 ml of water were added and stirred well and left as a slurry for 10 hours. Thereafter, 100 ml of zirconia beads having an average diameter of 0.5 mm and a slurry are put together in a vessel and dispersed for 5 hours with a disperser of the same type as that used for the preparation of the organic acid silver microcrystal dispersion. A solid microcrystalline dispersion of acid was obtained. As for the particle size of the solid fine particles, 70% by mass was 1.0 μm or less.

For other materials, in order to obtain a desired average particle size, the amount of the dispersant used and the dispersion time were appropriately changed to obtain a solid fine particle dispersion.
(Preparation of emulsion layer coating solution)
An emulsion coating solution was prepared by adding the following compositions to the previously prepared organic acid silver crystallite dispersion.

Organic acid silver microcrystal dispersion 1 mol Silver halide grain C 0.05 mol Binder: Latex of styrene-butadiene copolymer (Dainippon Ink Chemical Co., Ltd., LACSTAR 3307B
(Average particle size 0.1-0.15 μm) 430 g
Tetrachlorophthalic acid 5g
1,1-bis (2-hydroxy-3,5-dimethylphenyl)
-3,5,5-trimethylhexane 98 g
Phthalazine 9.0g
12g tribromomethylphenylsulfone
4-methylphthalic acid 7g
15 g of N- (2-methoxyphenyl) -N′-formylhydrazine
(Preparation of emulsion protective layer coating solution)
109 g of polymer latex having a solid content of 27.5% (copolymer of methyl methacrylate / styrene-2-ethylhexyl acrylate / 2-hydroxyethyl methacrylate methacrylic acid = 59/9/26/5/1, glass transition temperature 55 ° C.) 3.75 g of H ₂ O was added to the mixture, and 4.5 g of benzyl alcohol, 0.45 g of Compound D, 0.125 g of Compound E, 0.0125 g of Compound F, and polyvinyl alcohol (PVA-217, manufactured by Kuraray Co., Ltd.) as a film-forming aid. 2.25 g was added, and further H ₂ O was added to make 150 g to obtain a coating solution.
(Preparation of coating solution for back surface 3)
The following compositions were added to polyvinyl alcohol to prepare a back surface coating solution.

Polyvinyl alcohol 30g
Dye C 5g
250g of water
True spherical silica 1.8g
(Manufactured by Dokai Chemical Co., Sildex H121, average size 12 μm)

(Preparation of back surface 4 coating solution)
It was prepared in the same manner as the back surface 3 coating solution except that the amount of the spherical silica material was 2.5 g.

The emulsion layer coating solution prepared as described above was coated on a polyethylene terephthalate support so that the silver was 1.6 g / m ² , and the emulsion layer protective layer coating solution was simultaneously laminated so that the dry film thickness was 2 μm. Applied. After drying, a back surface coating solution was coated on the surface opposite to the emulsion layer so that the optical density at 780 nm was 0.7, thereby preparing a sample. The drying was performed at 60 ° C. for 30 minutes.

  The smoother value of the surface on the photosensitive layer side was 20 mmHg (≈266 kPa), and the smoother value of the surface on the backing side was 40 mmHg (≈532 kPa) on the back surface 3 and 150 mmHg (≈1995 kPa) on the back surface 4.

The photothermographic material produced as described above was evaluated in the same manner as in Example 1 using a roll-shaped sample similarly wound with a packaging material. The humidity sensitization was also evaluated as follows.
<Evaluation of humidity sensitization evaluation>
1) Evaluation of optical transmission density at 400 nm over time after heat development processing The prepared sample was divided into two, and one was put into a thermostat at 25 ° C. and 80% RH for 3 days as evaluation for the age. The unexposed sample was thermally developed at 120 ° C. for 25 seconds, and the transmission density at 400 nm of the unexposed portion was measured using a spectrophotometer U-3000 manufactured by Hitachi, Ltd. The variation rate of the transmission density after storage was evaluated from the transmission density before storage. The larger the variation rate, the longer the exposure of the PS plate, the next process, and the more likely the problem that fine halftone dots and lines are not reproduced (the larger the variation rate means the higher the sensitivity. ing).
2) Evaluation of performance fluctuation due to change in heat development processing conditions The prepared sample was divided into two parts, and one of them was put into a thermostat of 25 ° C. and 80% RH for 3 days as an evaluation for age. Using the image setter, halftone dots were exposed so as to change the exposure amount in 5% increments at 300 lines, and heat development was performed at 120 ° C. for 25 seconds. At that time, exposure and development were performed in a room adjusted to 23 ° C. and 50% RH. The density of the developed sample is measured with an optical densitometer (Konica: PDA-65), the sensitivity before storage at density 3 is taken as 100, and the rate of change of the sample after 3 days from the sensitivity before storage to the thermostat is taken as sensitivity. Evaluated (high fluctuation rate means sensitization).

  Tables 5 and 6 show the relationship between the oxygen transmission rate of the packaging material and each evaluation result, and Tables 7 and 8 show the relationship between the water transmission rate and each evaluation result.

Claims (4)

A photothermographic material having organic silver particles, photosensitive silver halide particles and a reducing agent on a support, and containing a hydrophobic binder in at least one layer, and having an oxygen permeability of 50 ml / atm · m ² · 25 ° C · A photothermographic material, wherein the photothermographic material is packaged with a packaging material of day or less. A photothermographic material having organic silver particles, photosensitive silver halide particles and a reducing agent on a support, and containing a hydrophobic binder in at least one layer, having a moisture permeability of 10 g / atm · m ² · 25 ° C · A photothermographic material, wherein the photothermographic material is packaged with a packaging material of day or less. A photothermographic material having organic silver particles, photosensitive silver halide particles and a reducing agent on a support and containing a polymer latex in at least one layer, and having an oxygen permeability of 50 ml / atm · m ² · 25 ° C · A photothermographic material, wherein the photothermographic material is packaged with a packaging material of day or less. A photothermographic material having organic silver particles, photosensitive silver halide particles and a reducing agent on a support and containing a polymer latex in at least one layer, having a moisture permeability of 10 g / atm · m ² · 25 ° C · A photothermographic material, wherein the photothermographic material is packaged with a packaging material of day or less.