JP2001051371A - Recording material having erasable color layer and heat-developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a material which is extremely stable during storage before treatment and in which colors can be easily erased by heating as required without causing color changes, by forming an erasable colored layer containing a specified color composition and a specified color erasing agent on a supporting body. SOLUTION: An erasable colored layer containing a coloring composition comprising at least an electron donating color developing organic compound and an acid developer, and a color erasing agent is present on a supporting body. The color erasing agent is selected from among aromatic hydrocarbons, alcohols, ethers, ketones, esters, amides, carboxylic acids, bases and basic precursors. A thermally erasable colored layer may be used for any emulsion layers or other hydrophilic colloid layers, and it may be used for a single layer or a plurality of layers. The thermally erasable colored layer absorbs unnecessary light in exposure process of an image to prevent halation or irradiation and to enhance sharpness of the image to be formed. When the colored layer consisting of the electron donating color developing compound and the acid developer is treated by heating, interaction of the two components is inhibited to decolor the layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a recording material.
More specifically, the present invention relates to a recording material having, on a support, a colored layer which is easily decolored by heating.

[0002]

2. Description of the Related Art In a light-sensitive material, a light-sensitive silver halide emulsion layer or another layer is often colored in order to absorb a specific wavelength.

For example, when it is necessary to control the spectral composition of light to be incident on a silver halide emulsion layer, a colored layer is provided on the photographic material at a position farther from the support than the emulsion layer. Such a colored layer is also called a filter layer. When there are a plurality of photographic emulsion layers such as a multilayer color light-sensitive material, a filter layer may be located between them.

Further, light scattered when passing through or after passing through the emulsion layer is reflected on the interface between the emulsion layer and the support or on the surface of the photosensitive material on the side opposite to the emulsion layer and reenters the emulsion layer. For the purpose of preventing image blurring due to the phenomenon, that is, halation, a coloring layer is provided between the emulsion layer and the support or on the surface of the support opposite to the emulsion layer. Such a colored layer is called an antihalation layer. In the case of a multi-layer color light-sensitive material, an antihalation layer may be provided between the layers.

Further, in order to prevent a decrease in image sharpness due to scattering of light in the emulsion layer (this phenomenon is generally called irradiation), the emulsion layer is colored. Therefore, the colored layer must be decolored when exposed with light having a wavelength in the visible region and used as a mask for exposure or when directly viewed.

In the case where the exposure wavelength is in the infrared region, even if an anti-irradiation layer or an anti-halation layer is provided, it is possible to eliminate the need to decolor the colored layer by selecting a dye having as small an absorption in the visible region as possible. it can. However, no infrared-absorbing dye having a sufficiently small absorption in the visible region and having a maximum absorption at 700 nm or more in a monomer state which is sufficiently stable even after treatment and does not generate colored stain has been found. Therefore,
Even when exposure is performed with light having a wavelength in the infrared region, it is necessary to decolor the absorption in the infrared to visible regions when using it as a mask for exposure or when viewing directly.

The above-described photosensitive material having a colored layer can be decolorized by liquid processing after exposure in a wet processing photosensitive material, but cannot be performed in a dry processing because such processing cannot be performed. Therefore, a mechanism for decoloring is required.

Several methods have been proposed for decoloring a colored layer in a dry processing photosensitive material. Some proposals to date include (1) U.S. Pat.
No. 9,019, No. 3,821,001, No. 4,0
No. 33,948, No. 4,088,497, No. 4,
Nos. 153,463 and 4,283,487, and JP-A Nos. 52-139136 and 53-132.
No. 334, No. 54-56818, No. 57-16060
And dyes which are decolorized by heat as described in JP-A-59-182436, or dyes which are decolorized by a corrosive gas generated from a counter salt upon heating described in US Pat. No. 4,347,401. A method using a colored layer as an antihalation layer; (2) an o-nitroarylidene dye or an o-nitro-o-azaary described in U.S. Pat. No. 3,984,248 and JP-A-54-17833. Liden dyes, as described in U.S. Pat. No. 3,770,451.
-O bond-cleavable dyes, chrominium-type cyanine dyes described in JP-A-2-229864, JP-A-59-1645.
No. 49, in which a colored layer containing a photo-decolorable dye such as an anionic dye containing an iodonium salt as a counter ion is used as an antihalation layer; -20734, described in JP-A-57-68831), azides (JP-A-63)
-14,028), ketone-based sensitizers (JP-A-5050)
-10618), mesoionic compounds (described in U.S. Pat. No. 4,548,895), iodonium compounds (described in U.S. Pat. No. 4,701,402), and active species generated by irradiating and / or heating these compounds. (4) A method in which a carbanion generator and a dye caused by heat coexist in a colored layer to cause decoloration during heating by reacting with a dye or interacting with an excited state of these compounds. (U.S. Pat. No. 5,135,842;
5,258,274, 5,314,795, 5,324,627, 5,384,237, EP 605286, JP-A-6-222504, and 7
199409).

However, in the method (1), there is a possibility that decolorization may occur during storage before processing or extra heat fog may be caused depending on temperature conditions. In the method (2), a special method is used. Since a dye is used, there have been problems such as difficulty in synthesis and selection of a dye having a desired absorption wavelength. The following is a common problem with the methods (2) and (3). However, since a large amount of radiation is required for decoloring, there is a possibility that photo discoloration may occur in the heat-developable photosensitive layer, or storage may occur. In many cases, the balance between the stability at the time and the decoloring property was insufficient. Another problem is that the processing takes time. (4)
In the above method, there is a concern that the dye is not completely decolored or that the color is recolored by an acid. On the other hand, Japanese Patent Publication No. 51-44706,
JP-A-1-44707 and JP-A-8-333567 disclose using an electron-donating color-forming organic compound, a compound having a phenolic hydroxyl group, alcohols, esters, ketones, ethers, amides or carboxylic acids. A temperature indicating material that reversibly decolors in response to a temperature change is disclosed. This material is a system that reversibly changes color according to temperature, and cannot be a means for irreversibly decoloring after the heat treatment, which is the object of the present invention. As an irreversible means, it is conceivable to give irreversibility by taking one component out of the three-component system out of the system, but in the case of dry treatment, only one component is selectively and completely removed. Removal is very difficult.

[0010]

SUMMARY OF THE INVENTION The present invention improves on these prior art problems. That is, an object of the present invention is to provide a photosensitive material having a high image sharpness having a colored layer which is extremely stable during storage before processing, but can be easily erased without causing discoloration by heating when necessary. To provide. Another object of the present invention is to make it possible to select a dye from a wide range for imparting absorption characteristics of a desired wavelength to the heat-decolorable coloring property. Another object of the present invention is to provide a printing plate having good resolution, which has a coloring layer which is extremely stable during storage before processing but can be easily erased without discoloration by heating when necessary. It relates to a heat-developable ultra-high contrast photosensitive material suitable for use.

[0011]

The above object has been attained by the following constitutions. <1> A coloring composition comprising at least an electron-donating color-forming organic compound and an acidic developer, and aromatic hydrocarbons, alcohols, ethers, ketones,
A recording material comprising a decolorizable coloring layer containing a decoloring agent selected from esters, amides, carboxylic acids, bases and base precursors. <2> At least one of the electron-donating color-forming organic compound, the color developer, and the decolorant has a polymerizable functional group, and the decolorizable color layer further contains a polymerization initiator, The recording material according to <1>. <3> a photothermographic material having a photothermographic layer containing at least a reducible silver salt, a photocatalytic substance and a reducing agent, wherein at least a colored substance comprising an electron-donating color developing organic compound and an acidic developer, and At least one decolorizable coloring layer containing a decoloring agent selected from aromatic hydrocarbons, alcohols, ethers, ketones, esters, amides, carboxylic acids, bases and base precursors is provided. Photothermographic material. <4> The photothermographic material as described in <3> above, wherein the reducible silver salt is an organic silver salt, the photocatalytic substance is a photosensitive silver halide, and further contains a super-high contrast agent. . <5> At least one of the electron-donating color-forming organic compound, the color developer, and the decolorant has a polymerizable functional group, and the decolorizable color layer further contains a polymerization initiator, The photothermographic material according to <3> or <4>.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

The heat-decolorable coloring layer used in the present invention can be used for any of an emulsion layer and other hydrophilic colloid layers (intermediate layer, protective layer, antihalation layer, back layer, etc.). It may be used for a single layer or for multiple layers.

The heat-decolorable colored layer of the present invention enhances the sharpness of an image formed by absorbing unnecessary light during image exposure to prevent halation, irradiation, etc. The colorant comprising the color former and the acidic developer decolorizes due to the inhibition of the interaction between the two components.

Hereinafter, the structure of the present invention will be described in more detail. The electron-donating color-forming organic compound used in the recording material of the present invention is a compound that generally develops a color under contact with a color developer, and is formed by the action of a base and / or heat or when the color developer is a metal of an organic acid. When it is a salt, it is decolorized by the action of a base and / or a complexing agent. Therefore, the color can be erased by introducing the electron-donating color-forming organic compound into the recording material in contact with the color developer and allowing the base and / or complexing agent to act during the treatment. The electron-donating color-forming organic compound used in the present invention is not particularly limited, and various substances including known substances can be used. For well-known electron-donating color-forming organic compounds, see Moriga, Yoshida, "Dyes and Chemicals", page 9, 84 (Chemical Products Industry Association, 1964): "New Edition Dye Handbook", page 242 (Maruzen, 1970); Garner
"Reports on the Progress of Appl. Chem." 56, 1
P. 99 (1971); "Dyes and chemicals", p. 19, 230 (Chemical Products Association, 1974);
Page (1989); "Dyeing Industry", 32, 208 and the like. Electron-donating color-forming organic compounds can be structurally classified into several systems. The system preferably used for the recording material of the present invention includes diarylphthalide system, fluoran system, indolylphthalide system, acylleukoazine system, leuco auramine system, spiropyran system, rhodamine lactam system, triarylmethane system, chromene And the like. Hereinafter, typical specific examples of the electron-donating color-forming organic compound that can be used in the recording material of the present invention are classified by structure, and the structural formulas are shown below.

(1) Diarylphthalide type

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(2) Fluoran type

[0019]

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[0020]

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[0021]

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[0022]

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(3) Indolyl phthalide type

[0024]

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[0025]

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[0026]

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(4) Acylleukoazine type

[0028]

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(5) Leuco auramine

[0030]

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(6) Spiropyran

[0032]

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(7) Rhodamine lactam type

[0034]

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(8) Triarylmethane type

[0036]

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(9) Chromene type

[0038]

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(10) Other systems

[0040]

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In recent years, laser light sources such as semiconductor lasers have rapidly become widespread. When these light sources are used, it is necessary to use an electron-donating color-forming organic compound which emits light in a wavelength region longer than 620 nm. Can be. Among such electron donating color-forming organic compounds, 2,6-diaminofluorane compounds having a cyclic structure at the 2- and 3-positions are described in JP-A-3-14878, JP-A-3-244587, JP-A-3-4-1587.
No. 73288, a fluoran compound having a p-phenylenediamine moiety as a substituent is disclosed in JP-A-61-28448.
5, JP-A-3-239587, JP-A-52-106873 for thiofluorane compounds, JP-A-5-139926 and 5-179151 for 3,3-bis (4-substituted aminophenyl) azaphthalide compounds
And phthalide compounds having a vinyl group are described in JP-B-58-5940, JP-B-58-27825, and JP-B-58-27825.
No. 4365, a fluorene compound is disclosed in
No. 94878, JP-A-3-202386, and a sulfonylmethane compound having a vinyl group is disclosed in
230890, 60-231766 and compounds having a phenothiazine or phenoxazine ring are described in JP-A-63-199268. Specific examples include the following electron-donating color-forming organic compounds.

[0042]

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[0043]

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[0044]

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[0045]

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[0046]

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The above specific examples are a part of the electron-donating color-forming organic compound, and the electron-donating color-forming organic compound used in the present invention is not limited to these.

Examples of the developer used in the present invention include acid clay type developer (clay), phenol-formaldehyde resin (eg, p-phenylphenol-formaldehyde resin), phenols, phenol metal salts, and carboxylic acid. Metal salts, benzophenones, sulfonic acids, sulfonates, phosphoric acids, metal phosphates, acid phosphates, acid phosphate metal salts, phosphorous acid,
Examples include acidic compounds such as metal phosphites. These can be used alone or in combination of two or more. Among these developers, phenols are preferred. Phenols include monohydric phenols, dihydric phenols, and polyhydric phenols, and further include an alkyl group, an aryl group, an acyl group, an alkoxycarbonyl group, a carboxy group and its ester or amide group as a substituent on the benzene ring, and a halogen. And bis-type and tris-type phenols. Examples of phenol compounds that cause the color of the electron-donating color-forming organic compound to be colored are shown below. Phenol, o-cresol, tertiary butylphenol, nonylphenol, n-octylphenol, n
-Dodecylphenol, n-stearylphenol, p
-Chlorophenol, p-bromophenol, o-phenylphenol, n-butyl p-hydroxybenzoate,
n-octyl p-hydroxybenzoate, n-dodecyl p-hydroxybenzoate, resorcinol, dodecyl gallate, 2,2-bis (4′-hydroxyphenyl) propane, 4,4′-dihydroxydiphenyl sulfone,
1-bis (4'-hydroxyphenyl) ethane, 2,2
-Bis (4'-hydroxy-3-methylphenyl) propane, bis (4'-hydroxyphenyl) methane, bis (4-hydroxyphenyl) sulfide, 1-phenyl-1,1-bis (4'-hydroxyphenyl) Ethane,
1,1-bis (4′-hydroxyphenyl) -3-methylbutane, 2,2-bis (4′-hydroxyphenyl)
Butane, 2,2-bis (4'-hydroxyphenyl) ethyl propionate, 2,2-bis (4'-hydroxyphenyl) -4-methylpentane, 1,1-bis (4'hydroxyphenyl) -2 -Methylpropane, 2,2-thiobis (6-tert-butyl-3-methylphenol), 2,2-bis (4'-hydroxyphenyl) hexafluoropropane, 1,1-bis (4'-hydroxyphenyl) n-hexane, 1,1-bis (4'-hydroxyphenyl) n-heptane, 1,1-bis (4'-hydroxyphenyl) n-octane, 1,1-bis (4 '
-Hydroxyphenyl) n-nonane, 1,1-bis (4′-hydroxyphenyl) n-decane, 1,1-bis (4′-hydroxyphenyl) n-dodecane, 2,2
-Bis (4'-hydroxyphenyl) n-heptane,
2,2-bis (4'-hydroxyphenyl) n-nonane, 1,1-bis (4'-hydroxyphenyl) -4-
Methylbutane, 1,1-bis (4′-hydroxyphenyl) n-pentane, 1,1-bis (4′-hydroxyphenyl) n-hexane, 1,1-bis (4′-hydroxyphenyl) n-heptane, 1,1-bis (4′-hydroxyphenyl) n-octane, 1,1-bis (4′-
(Hydroxyphenyl) n-nonane, 1,1-bis (4 ′
-Hydroxyphenyl) n-dodecane, 2,2-bis (4'-hydroxyphenyl) n-heptane, 2,2-
Bis (4'-hydroxyphenyl) n-nonane, 1,1
-Bis (3'-methyl-4'-hydroxyphenyl) n-
Hexane, 2,2-bis (4'-hydroxyphenyl)
Hexafluoropropane and the like can be mentioned. Preferred developers other than phenols include the following.

[0049]

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[0050]

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[0051]

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[0052]

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In the present invention, it is necessary that the above-mentioned electron-donating color-forming compound and the color developer are mixed to form a color. An electron-donating color-forming compound and a color developer may be mixed in advance and colored, and then added to the coating solution, or separately added to the coating solution and colored in the coating solution. In the present invention, a single electron-donating color-forming compound may be used,
Two or more electron-donating color-forming compounds may be used in combination.
When two or more kinds are used in combination, an electron-donating color-forming compound having the same color or an electron-donating color-forming compound having a different color may be used in combination. If necessary, an electron-donating color-forming compound having different colors depending on the layers used may be used.

The developer may be of one type or two or more types.

The coloring composition of the present invention comprising the electron-donating color-forming compound and the developer may be added to any layer of the light-sensitive material. That is, any layer of the photosensitive material may be a colored layer in the present invention. For example, the coloring composition of the present invention may be added to a silver halide emulsion layer for the purpose of preventing irradiation or the like, or may be added to a protective layer as a filter dye. Further, it may be added to the lower layer of the emulsion layer or the back surface of the support for the purpose of preventing halation.

The addition amount of the electron-donating color-forming compound of the present invention is 1 to 1 × 10 ⁴ mg / m ² , preferably 1 to 1 × 10 ³ mg / m ² . The amount of the developer of the present invention may be 0.1 to 1 of the added electron donating color forming compound.
It is 0 mol equivalent, preferably 0.5 to 4 mol equivalent.

The decoloring agent used in the present invention is selected from aromatic hydrocarbons, alcohols, ethers, ketones, esters, amides, carboxylic acids, bases and base precursors. Hydrocarbons, alcohols, esters, carboxylic acids, and ketones are preferred. Preferred examples of aromatic hydrocarbons include naphthalene, biphenyl, 1,2-diphenylethane, anthracene, phenanthrene, 2-methylnaphthalene, triphenylmethane, orthoterphenyl, metaterphenyl, terphenyltetraphenylethylene, , 6-
Examples thereof include dimethylnaphthalene, azulene, stilbene, durene, diphenylacetylene, and bibenzyl. Preferred examples of the alcohols include the following. Decane 1-ol, undecane 1-ol, lauryl alcohol, tridecane 1-
All, myristyl alcohol, pentadecane 1-ol, cetyl alcohol, heptadecane 1-ol, stearyl alcohol, octadecane 2-ol, eicosan 1-ol, docosan 1-ol, 6- (perfluoro-7-methyloctyl) hexanol, cyclo Dodecanol, 1,4-cyclohexanediol, 1,2-cyclohexanediol, 1,2-cyclododecanediol, sterol compounds such as cholesterol, stigmasterol, pregnenolone, methylandrostenediol, estradiol, benzoate, epiandrostene, Stenolone, β-sitosterol, pregnenolone acetate, β-cholesterol, 5,16
-Pregnadien-3β-ol-20-one, 5α-
Pregnen-3β-ol-20-one, 5-pregnen-3β, 17-diol-20-one 21-acetate, 5-pregnen-3β, 17-diol-20-
On 17-acetate, 5-pregnene-3β, 21
-Diol-20-one 21-acetate, 5-pregnene-3β, 17-diol diacetate, locogenin, tigogenin, esmilagenin, hecogenin, diosgenin, saccharides and derivatives thereof (eg glucose,
Saccharose) and alcohols having a cyclic structure (eg, 1,2,5,6-diisopropylidene-D-mannitol). The ester compounds applied to the present invention are roughly classified into the following (a) to (d). (A) Esters having a total carbon number of 10 or more composed of a monovalent fatty acid and an aliphatic monohydric alcohol or a monohydric alcohol having an alicyclic ring; (b) an aliphatic dihydric or polyhydric carboxylic acid; Polybasic acid esters having a total of 28 or more carbon atoms composed of a monohydric alcohol or an alicyclic monohydric alcohol (c) Esters having a total of 26 or more carbon atoms composed of an aliphatic dihydric or polyhydric alcohol and a monovalent fatty acid (D) Esters comprising a dihydric alcohol having an aromatic ring and a monovalent fatty acid and having a total of 28 or more carbon atoms

Esters having a total carbon number of 10 or more consisting of the monovalent fatty acid (a) and an aliphatic monohydric alcohol or a monohydric alcohol having an alicyclic ring are exemplified below. Ethyl caprylate, n-butyl caprylate, n-caprylate
-Octyl, lauryl caprylate, cetyl caprylate,
Stearyl caprylate, n-butyl caprate, n-hexyl caprate, myristyl caprate, docosyl caprate, methyl laurate, 2-ethylhexyl laurate, n-decyl laurate, stearyl laurate, ethyl myristate, myristic acid 3-methylbutyl, 2-methylpentyl myristate, n-myristate
-Decyl, cetyl myristate, stearyl myristate, isopropyl palmitate, neopentyl palmitate, n-nonyl palmitate, n-undecyl palmitate, lauryl palmitate, myristyl palmitate, cetyl palmitate, stearyl palmitate, cyclohexyl palmitate , Cyclohexylmethyl palmitate, methyl stearate, ethyl stearate,
N-propyl stearate, n-butyl stearate,
N-amyl stearate, 2-methylbutyl stearate, n-hexyl stearate, n-heptyl stearate, 3,5,5-trimethylhexyl stearate,
N-octyl stearate, 2-ethylhexyl stearate, n-nonyl stearate, n-decyl stearate, n-undecyl stearate, lauryl stearate, n-tridecyl stearate, myristyl stearate, n-pendadecyl stearate, Cetyl stearate, stearyl stearate, eicosyl stearate, n-docosyl stearate, cyclohexyl stearate, cyclohexylmethyl stearate, oleyl stearate, isostearyl stearate, 1,2
-N-butyl hydroxystearate, n-methyl behenate, n-ethyl behenate, n-propyl behenate, isopropyl behenate, n-butyl behenate, isobutyl behenate, 2-methylbutyl behenate, behenic acid n-amyl, neopentyl behenate, n-hexyl behenate,
2-methylpentyl behenate, n-heptyl behenate,
2-ethylhexyl behenate, n-nonyl behenate, myristyl behenate, n-undecyl behenate, lauryl behenate, n-tridecyl behenate, myristyl behenate, n-pendadecyl behenate, cetyl behenate, behenate There are stearyl acid and behenyl behenate.

The following are examples of the polybasic acid esters having a total carbon number of 28 or more consisting of the aliphatic dihydric or polyhydric carboxylic acid (b) and an aliphatic monohydric alcohol or an alicyclic monohydric alcohol. I do. Di-myristyl oxalate, di-cetyl oxalate, di-lauryl malonate, di-malonate
Cetyl, di-stearyl malonate, di-lauryl succinate, di-myristyl succinate, di-cetyl succinate, di-stearyl succinate, di-lauryl glutarate, di-undecyl adipate, di-lauryl adipate, Di-n-tridecyl adipate, di-myristyl adipate, di-cetyl adipate, di-stearyl adipate, di-n-docosyl adipate, di-n azelate
-Decyl, di-lauryl azelate, di-n-tridecyl azelate, di-n-nonyl sebacate, di-myristyl sebacate, di-stearyl sebacate, 1,
Di-n-pentyl 18-octadecylmethylenedicarboxylate, di-n-octyl 1,18-octadecylmethylenedicarboxylate, di- (cyclohexylmethyl) 1,18-octadecylmethylenedicarboxylate, 1,18-octadecylmethylylene dicarboxylic acid Di-neopentyl,
1,18-octadecylmethylenedicarboxylic acid-di-n
-Hexyl, 1,18-octadecylmethylenedicarboxylic acid-di-n-heptyl, and 1,18-octadecylmethylenedicarboxylic acid-di-n-octyl.

Examples of the aliphatic dihydric and polyhydric alcohols or esters having alicyclic or dihydric and polyhydric alcohols and monohydric fatty acids and having a total of 26 or more carbon atoms, which are described in (c) above, are shown below. Ethylene glycol di-myristate, ethylene glycol di-palmitate, ethylene glycol di-stearate, propylene glycol di-laurate, propylene glycol di-myristate, propylene glycol di-palmitate, butylene glycol di-stearate, hexylene glycol di Laurate, hexylene glycol di-myristate, hexylene glycol di-palmitate, hexylene glycol di-stearate, 1,5-pentanediol di-stearate, 1,2,6-hexanetriol-dimyristate, pentaerythritol Trimyristate, pentaerythritol tetralaurate, 1,4-cyclohexanediol didecyl, 1,4-cyclohexanediol dimyristyl, 1,4-si B hexanediol distearyl, 1,4-cyclohexanedimethanol dilaurate, Jimirisuteto like 1,4 cyclohexanedimethanol.

The esters (d) having a total of 28 or more carbon atoms and comprising a dihydric alcohol having an aromatic ring and a monovalent fatty acid are exemplified below. Xylene glycol di-caprinate, xylene glycol di-n-undecanoate, xylene glycol di-laurate, xylene glycol di-myristate, xylene glycol di-palmitate, xylene glycol di-stearate and the like.

Next, compounds having 10 or more carbon atoms are used as ketones, and examples thereof include decane 2-one, undecane 2-one, laurone, and stearone. As carboxylic acids, higher fatty acids having 12 or more carbon atoms are used, and lauric acid, myristic acid, palmitic acid, stearic acid,
Behenic acid and the like. The compounds are illustrated below as ethers. Butyl ether, hexyl ether, diisopropylbenzyl ether, diphenyl ether,
Dioxane, ethylene glycol dibutyl ether, diethylene glycol dibutyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol diphenyl ether, and the like. As the amides, compounds having 10 or more carbon atoms are preferably used. N-methyl lauric amide,
N, N-diethylstearic acid amide and N, N-diethylpalmitic acid amide can be mentioned. Also, alcohols, ethers, ketones, esters,
Compounds having both amide and carboxylic acid functional groups are also preferably used. For example, cholic acid, lithocholic acid, testosterone and cortisone, and derivatives thereof. Specific examples include cholic acid, cholic acid methyl ester, lithocholic acid, lithocholic acid methyl ester, hydroxycholic acid, hydroxycholic acid methyl ester,
Testosterone, methyltestosterone, 11α-hydroxymethyltestosterone, hydrocortisone. Among them, those having two or more hydroxyl groups are particularly preferable. Examples of the base and the base precursor include organic base compounds: for example, guanidines; guanidine, triphenylguanidine, tricyclohexylguanidine, and amines; amines having a large molecular weight such as dodecylamine, piperidine, morpholine, P-toluidine, 2-picoline, Benzoguanamine, 1-methyl-N
-Phenyl-N (phenylmethyl) -4-piperidiamine, diaminodiphenylmethane, 4- (methylsulfamoyl) -sulfanylanilide, 4,4'-tetramethyldiaminodiphenylmethane, spiroacetal diamine, N- (aminoalkyl) Lactams; glycidyl ether adducts of amines; and substituted oxazolines; for example, 2,4,4-trimethyl-2-oxazoline and the like and diamines having a cyclic structure in the molecule; for example, xylenediamine, dianisidine, N- A reaction product of an aminopropylpiperidine or the like or a polyamine derivative with an alkylene oxide; for example, polyoxyethylene alkylamine, polyoxypropylene alkylamine, or the like; or a quaternary ammonium salt; for example, dodecyltrimethylammonium chloride, octa Dodecyl ammonium chloride and amide compounds: for example, 4,4′-sulfonylbis (acetanilide), p-aminoacetanilide,
4′-butoxy-N-hydroxybenzeneacetamide and the like and ester compounds such as trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, 4-phenylmethylphenol carbamate, diphenyl phthalate, and glutamic acid-γ-alkyl ester residues Polymers and alcoholic compounds:
For example, benzacetin, 2,3-dihydro-2,2-dimethyl-7-benzofuranolmethylcarbamate, calactitol, and polyalkylene oxide compounds: for example, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyethylene glycol, polypropylene glycol Are preferred. Examples of the base precursor include salts of organic acids and bases that are decarboxylated by heating, compounds that release amines by reactions such as intramolecular nucleophilic substitution, Rossen rearrangement, and Beckmann rearrangement. Those which wake up and release a base are preferably used. Specific examples of the base precursor include acetic acid of a base represented by guanidine, triphenylguanidine, tricyclohexylguanidine, piperidine, morpholine, P-toluidine, 2-picoline, etc., trichloroacetic acid, phenylsulfonylacetic acid, 4-methylsulfonylphenyl Sulfonylacetic acid, 4-acetylaminomethylpropionic acid, oxalic acid,
Salts such as maleic acid, succinic acid, fumaric acid, carbonic acid and bicarbonate are preferred. These decoloring agents can be used alone or in combination of two or more. When a plurality of compounds are used in combination, there is an advantage that the temperature at which decoloration is caused can be adjusted. Preferred compounding ratios of the electron-donating color-forming organic compound, the color developer, and the color erasing agent in such a thermal color erasable coloring composition are as follows. The mixing ratio of the color developer is 0.1 to 1 with respect to 1 part by weight of the electron donating color developing organic compound.
It is preferably set to 0 parts by weight, more preferably 1 to 2 parts by weight. When the amount of the color developer is less than 0.1 part by weight, the coloration due to the interaction between the electron-donating color-forming organic compound and the color developer becomes insufficient. When the amount of the developer exceeds 10 parts by weight, it is difficult to sufficiently inhibit the interaction between the two. The compounding ratio of the decoloring agent is preferably set to 1 to 200 parts by weight, more preferably 5 to 100 parts by weight, per 1 part by weight of the electron-donating color-forming organic compound. When the amount of the decoloring agent is less than 1 part by weight, it is difficult to cause a state change from the colored state to the decolored state. If the decoloring agent exceeds 200 parts by weight, the coloring density decreases. The decoloring agent may be directly added to the coating solution containing the coloring composition comprising the electron-donating color-forming organic compound and the developer, or may be added to the electron-donating color-forming organic compound, the developer, and the decoloring agent. Add the agents separately. The decolorizable coloring composition may be formed in a coating solution. Either the coloring composition or the decoloring agent may be contained in the microcapsules.

The coloring composition comprising the electron-donating color-forming organic compound and the color developing agent and the decoloring agent are separated when stored at room temperature, so that the colored state is maintained. The interaction between the donor color-forming organic compound and the developer is cut off and the color is erased. In this case, when the interaction between the color developer and the decolorant is strong, the color is not colored even after cooling, and the decolored state is maintained. On the other hand, when the interaction between the color developer and the color erasing agent is weak, the interaction between the electron-donating color-forming organic compound and the color developer becomes stronger after cooling, so that the color elimination agent is separated again. Color again. In order to suppress such reversibility, the decolored state at the time of heating is fixed using polymerization, so that the decolored state after heating can be irreversibly maintained.

In order to maintain the decolored state by polymerization,
It is necessary to convert any one of the electron-donating color-forming organic compound, the color developer, and the color erasing agent into a polymerizable compound. ,
It is more preferable to impart polymerizability to the decoloring agent used in a large amount. Hereinafter, preferred polymerizable color developers and polymerizable decolorants will be described.

The polymerizable group of the polymerizable developer is preferably a radically polymerizable vinyl group. The radical polymerizable vinyl monomer having such a developer function is a vinyl monomer having an acidic group in the molecule, and the acidic group may be any of carboxylic acid, sulfuric acid, sulfonic acid, phosphoric acid, phenol and the like. Good. Of these, compounds having a phenol group are most preferably used. For example, JP-A-63-173682 and JP-A-4-24-2 can be used.
No. 26455, methacryloxyethyl ester of benzoic acid having a hydroxy group, acryloxyethyl ester which can be synthesized by the same synthetic method, and 59-hydroxybenzoic acid.
No. 83693, No. 60-141587, No. 62-99
No. 190, an ester of a benzoic acid having a hydroxy group and hydroxymethylstyrene, a hydroxystyrene described in EP 29323 and JP-A-62-167077 and JP-A-62-1708. Various compounds which can be synthesized with reference to a zinc halide N-vinylimidazole complex or a developer monomer described in JP-A-63-317558 can be used.

Specific examples include, for example, styrenesulfonylaminosalicylic acid, vinylbenzyloxyphthalic acid,
β-methacryloxyethoxysalicylate, β-acryloxyethoxysalicylate, vinyloxyethyloxybenzoic acid, β-methacryloxyethylorselinate, β-acryloxyethylorselinate, β-methacryloxyethoxyphenol, β- Acryloxyethoxyphenol, β-methacryloxyethyl-β-resorcinate, β-acryloxyethyl-β-resorcinate, hydroxystyrenesulfonic acid-N-ethylamide, γ-methacryloxypropyl-p-hydroxybenzoate, β-acryloxypropyl -P-hydroxybenzoate, methacryloxymethylphenol, acryloxymethylphenol, methacrylamidopropanesulfonic acid, acrylamidopropanesulfonic acid, β-
Methacryloxyethoxy-dihydroxybenzene, β-
Acryloxyethoxy-dihydroxybenzene, γ-styrenesulfonyloxy-β-methacryloxypropanecarboxylic acid, γ-acryloxypropyl-α-hydroxyethyloxysalicylic acid, β-hydroxyethoxycarbonylphenol, β-methacryloxyethyl-p-
Hydroxycinnamate, β-acryloxyethyl-p
-Hydroxycinnamate, 3,5-distyrenesulfonic acid amidophenol, methacryloxyethoxyphthalic acid, acryloxyethoxyphthalic acid, methacrylic acid, acrylic acid, methacryloxyethoxyhydroxynaphthoic acid, acryloxyethoxyhydroxynaphthoic acid, 3-
β-hydroxyethoxyphenol, β-methacryloxyethyl-p-hydroxybenzoate, β-acryloxyethyl-p-hydroxybenzoate, β′-methacryloxyethyl-β-resorcinate, β-methacryloxyethyloxycarbonylhydroxybenzoic acid, γ
-Methacryloxypropyl-3-chloro-4-hydroxybenzoate, γ-acryloxypropyl-3-chloro-4-hydroxybenzoate, β-acryloxyethyloxycarbonylhydroxybenzoic acid, N, N′-di-β-methacrylic acid Roxyethylaminosalicylic acid, N,
N′-di-β-acryloxyethylaminosalicylic acid,
-N, N'-di-β-methacryloxyethylaminosulfonylsalicylic acid, N, N'-di-β-acryloxyethylaminosulfonylsalicylic acid and the like, and metal salts thereof such as zinc salt and monoester of sulfuric acid of hydroxyethyl acrylate; Sulfuric acid monoester of hydroxyethyl methacrylate, acryloxyethanesulfonic acid, methacryloxyethanesulfonic acid, styrenesulfonic acid and the like can be preferably used.

The polymerizable decolorizing agent is preferably one having a radically polymerizable vinyl group in the molecule, similarly to the polymerizable color developing agent. As the radically polymerizable vinyl monomer having a decoloring property, a monomer having a polar group selected from an alcohol group, a carbonyl group, an ester group, an amide group, an ether group, and a carboxyl group is preferably used. Examples of these monomers include a monomer having an amide group in the molecule; for example, N-vinylpyrrolidone, N-vinylcaprolactam, and a compound represented by the following formula (Formula 25); a monomer having an ester group in the molecule; Monomers having an ether group in the molecule such as methylolpropane acrylate, trimethylolpropane trimethacrylate, ethylene glycol diacrylate and the compound of the following formula (Formula 26); A monomer having an alcohol group; for example, hydroxyethyl acrylate, hydroxyethyl methacrylate, etc., and the color-forming body formed by an electron-accepting compound of an electron-donating colorless dye can be decolorized and radically polymerizable. If a compound having a sulfonyl group not only to the above examples may be used any of the compounds.

[0068]

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[0069]

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In order to cause polymerization, polymerization is caused by a thermal polymerization initiator utilizing heat during thermal development, or light is applied during thermal development or before cooling after thermal development.
It is preferable to cause polymerization by the action of the photopolymerization initiator.

The heat radical generator which generates a radical by heating, which can use the heat-decolorable colored layer of the present invention, is known as a polymerization initiator in many cases.
R HAND BOOK '' (Brandrup, Immergut, Wiley Intersci
ence, 1989). In the present invention, a thermal radical generator generally used as a polymerization initiator can be used. Specifically, 2,2'-
Azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl-2,
2'-azobis (2-methylpropionate), dimethyl-2,2'-azobisisobutyrate, 2-cyano-
2-propylazoformamide, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (4-methoxy-2,4 -Dimethylvaleronitrile),
Azo-based initiators such as 2,2′-azobis [2- (2-imidazolin-2-yl) propane, azobis (2,4,4-trimethylpentane), lauryl peroxide, benzoyl peroxide, tert-butyl peroct Peroxide initiators such as ate, etc. Among these, those having an appropriate decomposition rate are desirable in order to achieve both stability during storage and reactivity during heating. Examples of the generator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), dimethyl-2,2′-azobis (2-methylpropionate) ), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis [2- (2-imidazolin-2-yl) And 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis [2- (2-imidazolin-2-yl) propane] is more preferred.

The amount of use of these thermal radical generators is an amount sufficient for radicals generated when these thermal radical generators are heated or other radicals generated by the reaction thereof to decolor the dye. It is necessary. Generally, an appropriate amount is determined by applying the composition in combination with a dye at various ratios, and generally about 0.1 mol to 100 mol, preferably 1 mol, of the thermal radical generator per 1 mol of the dye.
Molar to 10 moles are suitable.

The heat radical generator may be used as a mixture of two or more kinds, and there is no limitation on the method of adding the heat radical generator.

Many photoradical generators that generate radicals by light irradiation that can be used in the heat-decolorizable coloring layer of the present invention are known. For example, "sensitizers" (Katsumi Tokumaru and Nobuo Okawara) Hen, Kodansha Scientific, 1987
(1) aromatic carbonyl compounds, (2) organic peroxides, (3) azo compounds, (4) charge transfer type Can be classified into types. Hereinafter, each type will be specifically described. Examples of the aromatic carbonyl compound (1) include aromatic ketones, acetophenone derivatives, diketones, acyl oxime esters, acyl phosphine oxides, and the like. When
(b) It is divided into two types: cleavage type. The hydrogen abstraction type (a) abstracts hydrogen from a nearby compound from the excited triplet state of the carbonyl compound to generate two types of radicals.
On the other hand, in the cleavage type (b), two kinds of radicals are generated by causing a Norrish I-type cleavage reaction from the excited triplet state of the carbonyl compound. Specific examples include the following compounds, but are not limited thereto.

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[0076]

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The organic peroxide of (2) generates a carboxyl radical and a decarboxylated radical by photoexcitation. Specific examples of the compound are shown below, but it should not be construed that the invention is limited thereto.

[0078]

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Although many azo compounds are known as thermal polymerization initiators, they are also effective as photo-radical generators.
Specific examples of the compound are shown below, but it should not be construed that the invention is limited thereto.

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The charge transfer radical generator (4) is mainly used in combination with an aromatic ketone and an amine. When the aromatic ketone is photoexcited, electron transfer occurs first from the amine, and then radicals are generated by the transfer of protons. The main combinations are shown below, but are not limited thereto.

In the present invention, a photosensitive silver halide is preferably used as a photocatalytic substance, and an organic silver salt is preferably used as a reducible silver salt. The method for forming the photosensitive silver halide in the present invention is well known in the art, and for example, the method described in Research Disclosure No. 17029, June 1978 and US Pat. No. 3,700,458 can be used. Specific methods that can be used in the present invention include a method of converting a part of the silver of the organic silver salt to a photosensitive silver halide by adding a halogen-containing compound to the prepared organic silver salt, gelatin. Alternatively, a method in which a silver supply compound and a halogen supply compound are added to another polymer solution to prepare photosensitive silver halide grains and mixed with an organic silver salt can be used. In the present invention, the latter method can be preferably used. The grain size of the photosensitive silver halide is preferably small for the purpose of suppressing white turbidity after image formation, specifically, 0.20 μm or less, more preferably 0.01 μm or less.
μm to 0.15 μm, more preferably 0.02 μm to 0.1
It is preferably 2 μm or less. The grain size as used herein refers to the length of the edge of the silver halide grain when the silver halide grain is a cubic or octahedral so-called normal crystal. In the case where the silver halide grains are tabular grains, the diameter refers to a diameter when converted into a circular image having the same area as the projected area of the main surface. In the case of other than normal crystals, for example, in the case of spherical particles, rod-shaped particles, etc., it refers to the diameter of a sphere equivalent to the volume of silver halide grains.

The shape of the silver halide grains is cubic,
Octahedral, tabular particles, spherical particles, rod-like particles, potato-like particles and the like can be mentioned. In the present invention, cubic particles and tabular particles are particularly preferable. When tabular silver halide grains are used, the average aspect ratio is preferably from 100: 1 to 2: 1, more preferably from 50: 1 to 3: 1. Further, grains having rounded corners of silver halide grains can also be preferably used. The surface index (mirror index) of the outer surface of the photosensitive silver halide grains is not particularly limited, but the spectral sensitizing efficiency when the spectral sensitizing dye is adsorbed is high. preferable. The ratio is preferably at least 50%, more preferably at least 65%, even more preferably at least 80%. The ratio of the Miller index ｛100｝ plane is determined by the adsorption dependence of the sensitizing dye between the ｛111｝ plane and the ｛100｝ plane.T.Tani; J.Imaging Sci., 29,
165 (1985).
The halogen composition of the photosensitive silver halide is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide, and silver iodide. In the present invention, silver bromide or silver iodobromide can be preferably used. Particularly preferred is silver iodobromide, and the silver iodide content is preferably from 0.1 mol% to 40 mol%,
The content is more preferably from 0.1 mol% to 20 mol%. The distribution of the halogen composition in the grains may be uniform, the halogen composition may be changed stepwise, or may be changed continuously, but as a preferred example, the silver iodide content inside the grains is High silver iodobromide grains can be used. Preferably, silver halide grains having a core / shell structure can be used. The structure is preferably a 2- to 5-fold structure, more preferably a 2- to 5-layer structure.
Quadruplex core / shell particles can be used.

The photosensitive silver halide grains of the present invention preferably contain at least one complex of a metal selected from rhodium, rhenium, ruthenium, osmium, iridium, cobalt, mercury or iron. One type of these metal complexes may be used, or two or more types of complexes of the same metal and different metals may be used in combination. The preferred content is in the range of 1 nmol to 10 mmol per mol of silver, preferably 10 mol.
More preferably, the range is from n mol to 100 μmol. As a specific structure of the metal complex, a metal complex having a structure described in JP-A-7-225449 or the like can be used. cobalt,
As the iron compound, a hexacyano metal complex can be preferably used. Specific examples include ferricyanate ion, ferrocyanate ion, hexacyanocobaltate ion, and the like, but are not limited thereto. Even if the content of the metal complex in the silver halide is uniform,
The core portion may be contained at a high concentration, or the shell portion may be contained at a high concentration, and there is no particular limitation.

The photosensitive silver halide grains can be desalted by washing with a method known in the art, such as a noodle method or 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. As a preferred chemical sensitization method, a sulfur sensitization method, a selenium sensitization method, and a tellurium sensitization method are well known in the art. Further, a noble metal sensitization method or a reduction sensitization method of a gold compound, platinum, palladium, an iridium compound or the like can be used. As the compound preferably used in the sulfur sensitization method, the selenium sensitization method, and the tellurium sensitization method, known compounds can be used, and the compounds described in JP-A-7-128768 can be used. Examples of tellurium sensitizers include diacyl tellurides, bis (oxycarbonyl) tellurides,
Bis (carbamoyl) tellurides, diacyltellurides, bis (oxycarbonyl) ditellurides, bis (carbamoyl) ditellurides, compounds having a P = Te bond,
Tellurocarboxylates, Te-organyltellurocarboxylates, di (poly) tellurides, tellurides,
Tellurols, telluroacetals, tellursulfonates, compounds having a P-Te bond, Te-containing heterocycles, tellurocarbonyl compounds, inorganic tellurium compounds, colloidal tellurium, and the like can be used. Compounds preferably used in the noble metal sensitization method include, for example, chloroauric acid, potassium chloroaurate, potassium aurithiocyanate,
Gold sulfide, gold selenide, or US Patent 2,448,060
And British Patent No. 618,061 can be preferably used. Specific compounds of the reduction sensitization method include, as well as ascorbic acid, thiourea dioxide, for example, stannous chloride, aminoiminomethanesulfinic acid, hydrazine derivatives, borane compounds, silane compounds,
A polyamine compound or the like can be used. Reduction sensitization can be achieved by ripening the emulsion while maintaining the pH of the emulsion at 7 or more or the pAg at 8.3 or less. Further, reduction sensitization can be achieved by introducing a single addition portion of silver ions during grain formation.

The amount of the photosensitive silver halide used in the present invention is preferably 0.01 mol 0.5 mol or less, more preferably 0.02 mol or more and 0.3 mol or less, and more preferably 0.03 mol or less with respect to 1 mol of the organic silver salt. Particularly preferred is 0.25 mol or less. Regarding the mixing method and the mixing conditions of the separately prepared photosensitive silver halide and organic silver salt, the prepared silver halide particles and organic silver salt were mixed with a high-speed stirrer, a ball mill, a sand mill, a colloid mill, a vibration mill, and a homogenizer. And the like, or a method of preparing an organic silver salt by mixing photosensitive silver halide prepared at any timing during the preparation of the organic silver salt. There is no particular limitation as long as it appears in.

As the silver halide preparation method of the present invention, a so-called halation method in which a part of silver of an organic silver salt is halogenated with an organic or inorganic halide is also preferably used. The organic halide used here may be any compound as long as it is a compound that reacts with an organic silver salt to generate a silver halide. Tetrabutylammonium bromide, etc.), associates of halogenated quaternary nitrogen salts with halogen molecules (pyridinium bromide perbromide)
And the like. As the inorganic halogen compound, any compound may be used as long as it reacts with an organic silver salt to generate silver halide, and an alkali metal or ammonium halide (such as sodium chloride, lithium bromide, potassium iodide, ammonium bromide, etc.) ), Alkaline earth metal halides (such as calcium bromide and magnesium chloride), transition metal halides (such as ferric chloride and cupric bromide), and metal complexes having a halogen ligand (sodium iridium bromide) , Ammonium rhodate, etc.), and halogen molecules (bromine, chlorine, iodine). Further, a desired organic / inorganic halide may be used in combination.

In the present invention, the halide is added in an amount of preferably 1 to 500 mmol, more preferably 10 to 25 mmol, as a halogen atom per 1 mol of the organic silver salt.
0 mmol is more preferred.

The organic silver salt that can be used in the present invention is
Relatively stable to light, but forms a silver image when heated to 80 ° C or higher in the presence of an exposed photocatalyst (such as a latent image of photosensitive silver halide) and a reducing agent It is a silver salt. The organic silver salt can be any organic substance including a source capable of reducing silver ions. Silver salts of organic acids,
Particularly, a silver salt of a long-chain fatty carboxylic acid (having 10 to 30 carbon atoms, preferably 15 to 28 carbon atoms) is preferred. Complexes of organic or inorganic silver salts whose ligands have a complex stability constant in the range of 4.0 to 10.0 are also preferred. The silver donor material is preferably about 5% of the imaging layer.
Up to 70% by weight. Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. Examples of these include, but are not limited to, silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids.
Preferred examples of the silver salt of an aliphatic carboxylic acid include silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, silver maleate, and fumarate. Silver acid, silver tartrate,
Silver linoleate, silver butyrate and silver camphorate, and mixtures thereof.

Silver salts of compounds containing a mercapto group or a thione group and derivatives thereof can also be used.
Preferred examples of these compounds include silver salts of 3-mercapto-4-phenyl-1,2,4-triazole,
Silver salt of mercaptobenzimidazole, silver salt of 2-mercapto-5-aminothiadiazole, silver salt of 2- (ethylglycolamide) benzothiazole, S-alkylthioglycolic acid (where the alkyl group has 12 carbon atoms)
-22), such as a silver salt of thioglycolic acid;
Silver salt of dithiocarboxylic acid such as silver salt of dithioacetic acid, silver salt of thioamide, silver salt of 5-carboxyl-1-methyl-2-phenyl-4-thiopyridine, silver salt of mercaptotriazine, and silver salt of 2-mercaptobenzoxazole Silver salt,
Silver salts described in U.S. Pat. No. 4,123,274, for example silver salts of 1,2,4-mercaptothiazole derivatives such as silver salts of 3-amino-5-benzylthio-1,2,4-thiazole;
Silver salts of thione compounds such as the silver salt of 3- (3-carboxyethyl) -4-methyl-4-thiazoline-2-thione described in U.S. Pat. No. 3,301,678. Further, compounds containing an imino group can also be used. Preferred examples of these compounds include silver salts of benzotriazole and derivatives thereof, for example, silver salts of benzotriazole such as silver methylbenzotriazole, silver salts of halogen-substituted benzotriazole such as silver 5-chlorobenzotriazole, and US Pat. And silver salts of 1,2,4-triazole or 1-H-tetrazole as described in 4,220,709, and silver salts of imidazole and imidazole derivatives. For example, U.S. Pat.
Various silver acetylide compounds as described in 761,361 and 4,775,613 can also be used.

The shape of the organic silver salt that can be used in the present invention is not particularly limited, but a needle crystal having a short axis and a long axis is preferable. In the present invention, the minor axis is 0.01 μm or more.
20 μm or less, major axis 0.10 μm or more and 5.0 μm or less, minor axis 0.01 μm or more and 0.15 μm or less, major axis 0.10 μm or more
It is more preferably 4.0 μm or less. The particle size distribution of the organic silver salt is preferably monodispersed. Monodispersion means that the percentage of the value obtained by dividing the standard deviation of the length of each of the minor axis and major axis by the minor axis and major axis is preferably 100% or less, more preferably 80% or less, and still more preferably 50% or less. is there. The shape of the organic silver salt can be measured from a transmission electron microscope image of the organic silver salt dispersion. As another method of measuring the monodispersity, there is a method of obtaining the standard deviation of the volume-weighted average diameter of the organic silver salt, and the percentage (coefficient of variation) divided by the volume-weighted average diameter is preferably 100% or less,
It is more preferably at most 80%, further preferably at most 50%. As a measuring method, for example, the organic silver salt dispersed in a liquid is irradiated with laser light, and the particle size (volume weight average diameter) obtained by obtaining an autocorrelation function with respect to a time change of the fluctuation of the scattered light is obtained. Can be.

The organic silver salt that can be used in the present invention includes:
Preferably, desalting can be performed. The method for desalting is not particularly limited, and a known method can be used. However, a known filtration method such as centrifugal filtration, suction filtration, ultrafiltration, and floc forming water washing by a coagulation method can be preferably used. .

For the purpose of obtaining fine particles having a small particle size and no aggregation, the method of preparing a solid fine particle dispersion using a dispersant is used for the organic silver salt which can be used in the present invention. The method of dispersing the organic silver salt into solid fine particles is carried out by using a known fine means (for example, a ball mill, a vibrating ball mill, a planetary ball mill, a sand mill, a colloid mill, a jet mill, a roller mill) in the presence of a dispersing aid. Can be dispersed.

When the organic silver salt is formed into solid fine particles using a dispersant, for example, polyacrylic acid, a copolymer of acrylic acid, a maleic acid copolymer, a maleic acid monoester copolymer, and acryloylmethyl Synthetic anionic polymers such as propane sulfonic acid copolymer, semi-synthetic anionic polymers such as carboxymethyl starch and carboxymethyl cellulose, anionic polymers such as alginic acid and pectic acid, JP-A-52-92716, WO88 / 04794, etc. Anionic surfactant described, compounds described in Japanese Patent Application No. 7-350753, or known anionic, nonionic,
Cationic surfactants and other known polymers such as polyvinyl alcohol, polyvinylpyrrolidone, carboxymethylcellulose, hydroxypropylcellulose, and hydroxypropylmethylcellulose, or naturally occurring polymer compounds such as gelatin can be appropriately selected and used. .

It is a general method that the dispersing aid is mixed with the organic silver salt powder or the organic silver salt in a wet cake state before dispersion and then sent as a slurry to a dispersing machine. Heat treatment or treatment with a solvent may be performed in the combined state to obtain an organic silver salt powder or a wet cake. The pH may be controlled with a suitable pH adjuster before, during or after dispersion.

Instead of mechanically dispersing, fine particles may be formed by coarsely dispersing in a solvent by controlling the pH and then changing the pH in the presence of a dispersing aid. At this time, an organic solvent may be used as a solvent used for the coarse dispersion, and the organic solvent is usually removed after completion of the fine particle formation.

The prepared dispersion may be stored with stirring for the purpose of suppressing sedimentation of fine particles during storage, or stored in a highly viscous state by a hydrophilic colloid (for example, in a jelly state using gelatin). You can also.
Further, a preservative can be added for the purpose of preventing the propagation of various bacteria during storage.

[0099] The organic silver salt of the present invention can be used in a desired amount, preferably 0.1-5 g / m ^2, more preferably is 1 to 3 g / m ² expressed in an amount per photographic material 1 m ² .

The reducing agent used in the present invention may be any substance that reduces silver ions to metallic silver, preferably an organic substance. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful, but hindered phenol reducing agents are preferred. The reducing agent is preferably contained in an amount of 5 to 50% (mole), more preferably 10 to 40% (mole), based on 1 mol of silver on the surface having the image forming layer. The layer to which the reducing agent is added may be any layer on the side having the image forming layer. When it is added to a layer other than the image forming layer, it is preferable to use a relatively large amount of 10 to 50% (mol) with respect to 1 mol of silver. Further, the reducing agent may be a so-called precursor which is derivatized so as to have a function effectively only during development.

In photothermographic materials utilizing organic silver salts, a wide range of reducing agents are disclosed in JP-A-46-6074 and JP-A-47-1238.
No. 47-33621, No. 49-46427, No. 49-115540, No.
50-14334, 50-36110, 50-147711, 51-326
No. 32, No. 51-1023721, No. 51-32324, No. 51-51933,
52-84727, 55-108654, 56-146133, 57
-82828, 57-82829, JP-A-6-3793, U.S. Pat.
667,9586, 3,679,426, 3,751,252, 3,75
No. 1,255, No. 3,761,270, No. 3,782,949, No. 3,839,
No. 048, 3,928,686, 5,464,738, German patent 23
No. 21328 and European Patent No. 692732. For example, amide oximes such as phenylamidooxime, 2-thienylamidooxime and p-phenoxyphenylamidooxime; azines such as 4-hydroxy-3,5-dimethoxybenzaldehydeazine; 2,2-bis (hydroxymethyl) propionyl- a combination of an aliphatic carboxylic acid arylhydrazide such as a combination of β-phenylhydrazine and ascorbic acid with ascorbic acid; a combination of polyhydroxybenzene with hydroxylamine, reductone and / or hydrazine (eg, hydroquinone and bis (ethoxyethyl) ) Hydroxylamine, piperidinohexose reductone or formyl-4
-Hydroxamic acids such as phenylhydroxamic acid, p-hydroxyphenylhydroxamic acid and β-alinine hydroxamic acid; combinations of azine and sulfonamidophenol (eg phenothiazine and 2,6-dichloro-). 4-benzenesulfonamidophenol, etc.); ethyl-α-cyano-2-
Α-cyanophenylacetic acid derivatives such as methylphenylacetate and ethyl-α-cyanophenylacetate; 2,2-
Dihydroxy-1,1-binaphthyl, 6,6-dibromo-2,2-dihydroxy-1,1-binaphthyl and bis (2-hydroxy
1-naphthyl) bis-β-naphthol as exemplified by methane; bis-β-naphthol and 1,3-dihydroxybenzene derivatives (eg, 2,4-dihydroxybenzophenone or 2,4-dihydroxyacetophenone, etc.) Combinations; 5-pyrazolone, such as 3-methyl-1-phenyl-5-pyrazolone; as exemplified by dimethylaminohexose reductone, anhydrodihydroaminohexose reductone and anhydrodihydropiperidone hexose reductone Reductones; sulfonamide phenol reducing agents such as 2,6-dichloro-4-benzenesulfonamidophenol and p-benzenesulfonamidophenol;
2-phenylindane-1,3-dione, etc .; 2,2-dimethyl-
Chromans such as 7-t-butyl-6-hydroxychroman;
1,4-dihydropyridines such as 2,6-dimethoxy-3,5-dicarbethoxy-1,4-dihydropyridine; bisphenols (eg, bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-ethylidene-bis (2-t-butyl-6-methylphenol), 1,1, -bis (2-hydroxy
(-3,5-dimethylphenyl) -3,5,5-trimethylhexane and 2,2-bis (3,5-dimethyl-4-hydroxyphenyl)
Ascorbic acid derivatives (eg, 1-ascorbyl palmitate, ascorbyl stearate, etc.); aldehydes and ketones such as benzyl and biacetyl; 3-pyrazolidone and certain indan-1,3-diones; chromanol (tocopherol) Etc.). Particularly preferred reducing agents are bisphenol and chromanol.

The reducing agent of the present invention may be added by any method such as a solution, a powder, and a dispersion of solid fine particles. The dispersion of the solid fine particles is carried out by a known fine means (for example, ball mill, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

When an additive known as a "toning agent" for improving an image is contained, the optical density may be increased. The toning agent may also be advantageous in forming a black silver image. The toning agent is preferably contained in an amount of 0.1 to 50% (mole) per mole of silver on the surface having the image forming layer, and more preferably 0.5 to 20% (mole). Further, the color tone agent may be a so-called precursor which is derivatized so as to have a function effectively only during development.

In a photothermographic material utilizing an organic silver salt, a wide range of color toning agents are disclosed in JP-A-46-6077 and JP-A-47-10282.
Nos. 49-5019, 49-5020, 49-91215, 49
-91215, 50-5024, 50-32927, 50-67132
No. 50-67641, No. 50-114217, No. 51-3223, No. 5
1-27923, 52-14788, 52-99813, 53-1020
No. 53-76020, No. 54-156524, No. 54-156525,
No. 61-183642, JP-A-4-56848, JP-B-49-10727
No. 54-20333, U.S. Pat.Nos. 3,080,254, 3,446,64
No. 8, 3,782,941, 4,123,282, 4,510,236
And British Patent 1,380,795 and Belgian Patent 841,910. Examples of toning agents are phthalimide and N-hydroxyphthalimide; succinimide, pyrazolin-5-one, and quinazolinone, 3-phenyl-2-
Cyclic imides such as pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione;
Naphthalimide (eg, N-hydroxy-1,8-naphthalimide); cobalt complex (eg, cobalt hexamine trifluoroacetate); 3-mercapto-1,2,4-triazole, 2,4-dimercaptopyrimidine, 3 -Mercapto
Mercaptans exemplified by -4,5-diphenyl-1,2,4-triazole and 2,5-dimercapto-1,3,4-thiadiazole; N- (aminomethyl) aryldicarboximides (for example, (N , N-Dimethylaminomethyl) phthalimide and N, N- (dimethylaminomethyl) -naphthalene-
2,3-dicarboximide); and blocked pyrazoles, isothiuronium derivatives, and certain photobleaching agents (eg, N, N'-hexamethylenebis (1-carbamoyl-3,5-dimethylpyrazole), 1,8 -(3,6-diazaoctane) bis (isothiuronium trifluoroacetate) and 2-tribromomethylsulfonyl)-(benzothiazole)); and 3-ethyl-5 [(3-ethyl-2-benzothiazolini) Ridene) -1-methylethylidene] -2-thio-
2,4-oxazolidinedione; phthalazinone, phthalazinone derivative or metal salt, or 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethoxyphthalazinone and 2,3-dihydro-1,4- Derivatives such as phthalazinedione; combinations of phthalazinone with phthalic acid derivatives (eg, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride); phthalazine, phthalazine derivatives or metal salts, or (1
-Naphthyl) derivatives such as phthalazine, 6-chlorophthalazine, 5,7-dimethoxyphthalazine and 2,3-dihydrophthalazine; phthalazine and phthalic acid derivatives (eg phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid) And quinazolinedione, benzoxazine or naphthoxazine derivatives; rhodium complexes that function not only as color tone modifiers but also in situ as halide ion sources for silver halide formation; Such as ammonium hexachlororhodate (III), rhodium bromide, rhodium nitrate and potassium hexachlororhodate (III); inorganic peroxides and persulfates, such as ammonium disulfide and hydrogen peroxide; Benzoxazine-2,4-dione, 8-methyl-1,3-benzoxazine-2,4-di And benzoxazine-2,4-diones such as 6-nitro-1,3-benzoxazine-2,4-dione; pyrimidines and asymmetric triazines (eg, 2,4-dihydroxypyrimidine, 2-hydroxy-4- Aminopyrimidine, etc.), azauracil, and tetraazapentalene derivatives (eg, 3,6-dimercapto-1,4-diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene, and 1,4- And di (o-chlorophenyl) -3,6-dimercapto-1H, 4H-2,3a, 5,6a-tetraazapentalene.

The color tone agent of the present invention may be added by any method such as a solution, a powder, and a solid fine particle dispersion. The dispersion of the solid fine particles is carried out by a known fine means (for example, ball mill, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

As the binder for the emulsion layer in the present invention, well-known natural or synthetic resins such as gelatin, polyvinyl acetal, polyvinyl chloride,
Any one can be selected from polyvinyl acetate, cellulose acetate, polyolefin, polyester, polystyrene, polyacrylonitrile, polycarbonate and the like. Of course, copolymers and terpolymers are also included. Preferred polymers are polyvinyl butyral, butylethyl cellulose, methacrylate copolymer, maleic anhydride copolymer, polystyrene and butadiene-styrene copolymer. If necessary, two or more of these polymers can be used in combination. Such a polymer is used in an amount sufficient to hold the components therein. That is, it is used in an effective range to function as a binder.

In the present invention, a binder obtained by dispersing a hydrophobic polymer in an aqueous solvent may be used as the binder for the emulsion layer. The aqueous solvent here is water or a mixture of water and 70% by weight or less of a water-miscible organic solvent. Examples of the water-miscible organic solvent include methanol, ethanol, propanol, ethyl acetate, dimethylformamide, methyl cellosolve, butyl cellosolve and the like. Specific examples of the solvent composition include water / methyl alcohol = 90/10 or 70/30 or 50/50, water / isopropyl alcohol = 90/10, water / butyl cellosolve = 95/5, and water / dimethylformamide = 95.
/ 5, water / methyl alcohol / dimethylformamide =
90/5/5 or 80/15/5 (or more by weight).

The term “dispersion” as used herein refers to a state in which the polymer is not thermodynamically dissolved in the solvent but is dispersed in the latex, micelle state, or molecular dispersion state in the aqueous solvent. As the binder of the present invention, among these polymers, those having an "equilibrium water content at 25 ° C. and 60% RH" of 2 wt% or less are particularly preferred. The lower limit of the equilibrium water content is not particularly limited, but is preferably 0.01 wt%, more preferably 0.03 wt%. Here, the “equilibrium moisture content at 25 ° C and 60% RH” is the weight of the polymer that has reached the humidity control equilibrium in an atmosphere of 25 ° C and 60% RH, and the weight of the polymer that has been completely dried at 25 ° C.
It can be expressed as follows using W0.

“Equilibrium moisture content at 25 ° C. and 60% RH” = ｛(W
1-W0) / W0｝ × 100 (wt%) The polymer of the present invention is not particularly limited as long as it can be dispersed in the above-mentioned aqueous solvent. Examples include vinylidene resin, rubber-based resin (for example, SBR resin, NBR resin, etc.), vinyl acetate resin, polyolefin resin, polyvinyl acetal resin, and the like. The polymer may be a homopolymer or a copolymer in which two or more monomers are polymerized. The polymer may be linear or branched. Further, the polymers may be crosslinked. The number average molecular weight of the polymer is 1,00
Desirable is 0-1,000,000, preferably 3,000-500,000. Those having a number average molecular weight of less than 1,000 generally have low film strength after coating, and may cause inconvenience such as cracking of the photosensitive material. Among them, styrene-butadiene copolymers are preferable, although they are included in the above-mentioned SBR resin.

The “styrene-butadiene copolymer” used in the present invention is a polymer containing styrene and butadiene in the molecular chain. The molar ratio of styrene-butadiene is preferably from 99: 1 to 40:60.

The “styrene-butadiene copolymer” of the present invention also includes esters of acrylic acid or methacrylic acid such as methyl methacrylate and ethyl methacrylate, acids such as acrylic acid, methacrylic acid and itaconic acid, or acrylonitrile. Other vinyl monomers such as divinylbenzene may be copolymerized. Preferably, styrene-butadiene is present at 50% by weight or more.

The styrene-butadiene copolymer used in the present invention has a number average molecular weight of 2,000 to 1,
1,000,000, more preferably 5,000-500,
A range of 000 is preferred.

The styrene-butadiene copolymer of the present invention is usually a random copolymer, but these copolymers may be linear polymers, branched or crosslinked. Usually, it is used as particles having an average particle size of about 0.01 to 1 μm.

Specific examples of the polymer of the present invention include acrylic resins such as Sebian A-4635, 46584, and 4601 (all manufactured by Daicel Chemical Industries, Ltd.), Nipol LX811, 814, and 820;
821, 857 (both manufactured by Nippon Zeon Co., Ltd.) and other polyester resins such as FINETEX ES650, 611, 679, 67
5, 525, 801 and 850 (all manufactured by Dainippon Ink and Chemicals, Inc.)
, Wdsize WMS (Eastman Chemical) and others. Specific examples of the rubber-based (SBR) resin or styrene-butadiene copolymer are as follows.

Latex of P-1-St70-Bu30- (Mn = 30000) Latex of P-2-St60-Bu37-MAA3- (M
n = 45000) Latex of P-3-St50-Bu40-AN7-AA3- (Mn = 70000) Latex of P-4-St70-Bu20-DVB5-MAA5- (Mn = 100000) P-5-St50-Bu30- AN15-IA5-Latex (Mn = 60000) The abbreviations here represent structural units derived from the following monomers, numerical values are% by weight, and Mn is the number average molecular weight.

St: styrene, Bu: butadiene, MA
A: methacrylic acid, AN: acrylonitrile, AA: acrylic acid, DVB:
Divinylbenzene IA: itaconic acid Luckstar 3307B, DS-205, 602, Luckstar DS203, 7132C, DS807 (all manufactured by Dainippon Ink and Chemicals, Inc.), Nippol 2507, Lx41
6, Lx433, Lx410, Lx430, Lx435
(Nippon Zeon Co., Ltd.), DL-670, L-57
02, 1235 (these are Asahi Kasei Corporation).

In the binder of the present invention, these polymers may be used alone or in combination of two or more.

In the present invention, when a styrene-butadiene copolymer, which is preferably used as a binder, is used as a binder, the above-mentioned solvent is used to form a coating solution having a solid concentration of 0.5 to 12% by weight.
More preferably, the content is in the range of 1 to 8% by weight.

The effective range of the amount of the binder used can be appropriately determined by those skilled in the art. As a guide when at least the organic silver salt is retained, the ratio of the binder to the organic silver salt is 15: 1 to 1: 3, particularly 8: 1 to 1: 2 by weight.
Is preferable.

As the sensitizing dye in the present invention, any dye can be used as long as it can spectrally sensitize silver halide grains in a desired wavelength region when adsorbed on silver halide grains. As the sensitizing dye, a cyanine dye, a merocyanine dye, a complex cyanine dye, a complex merocyanine dye, a holopolar cyanine dye, a styryl dye, a hemicyanine dye, an oxonol dye, a hemioxonol dye, and the like can be used. Useful sensitizing dyes for use in the present invention include, for example, RESEARCH DISCLOSURE Item 17
Item 643IV-A (p.23, December 1978), Item 1831 Item X (1979
August, p. 437). Especially various laser imagers, scanners,
A sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of a light source of an image setter or a plate making camera can be advantageously selected.

Examples of spectral sensitization to red light include He-Ne
For so-called red light sources such as lasers, red semiconductor lasers and LEDs, the I-1 described in JP-A-54-18726 is used.
Compound of I-38, I-1 to I-35 described in JP-A-6-75322
Compounds and I-1 to I-34 described in JP-A-7-287338
From the dyes 1 to 20 described in JP-B-55-39818, from the compounds I-1 to I-37 described in JP-A-62-284343, and from the compounds described in JP-A-7-287338. The compound of I-34 and the like are advantageously selected.

For semiconductor laser light sources in the wavelength range of 750 to 1400 nm, various known dyes including cyanine, merocyanine, styryl, hemicyanine, oxonol, hemioxonol and xanthene dyes are spectrally advantageously sensitized. Can be done. Useful cyanine dyes are, for example, cyanine dyes having basic nuclei such as thiazoline nuclei, oxazoline nuclei, pyrroline nuclei, pyridine nuclei, oxazole nuclei, thiazole nuclei, selenazole nuclei and imidazole nuclei. Preferred useful merocyanine dyes include, in addition to the above basic nuclei, acidic nuclei such as thiohydantoin nucleus, rhodanine nucleus, oxazolidinedione nucleus, thiazolinedione nucleus, barbituric acid nucleus, thiazolinone nucleus, malononitrile nucleus and pyrazolone nucleus. Including. Among the above-mentioned cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective. For example, U.S. Pat.
No. 3,719,495; No. 3,877,943; British Patent No.
Nos. 1,466,201, 1,469,117, 1,422,057,
JP-B-3-10391, JP-B6-52387, JP-A-5-341432,
The dye may be appropriately selected from known dyes as described in JP-A-6-94781 and JP-A-6-301141.

Particularly preferred as the structure of the dye used in the present invention is a cyanine dye having a thioether bond-containing substituent (for example, JP-A Nos. 62-58239 and 3-1386).
No.38, No.3-138642, No.4-255840, No.5-72659, No.
5-72661, 6-222491, 2-230506, 6-258757
No., 6-317868, 6-324425, Tokuyohei 7-500926,
Dyes described in US Pat. No. 5,541,054), dyes having a carboxylic acid group (for example, JP-A-3-163440, JP-A-6-163440)
No. 301141, U.S. Pat.No.5,441,899)
, Merocyanine dyes, polynuclear merocyanine dyes and polynuclear cyanine dyes (JP-A-47-6329, JP-A-49-105524, and
-127719, 52-80829, 54-61517, 59-21484
No. 6, No. 60-6750, No. 63-159841, JP-A-6-35109
No. 6-59381, No. 7-46537, No. 7-46537, JP-T 55-50111, UK Patent No. 1,467,638, U.S. Patent No. 5,
No. 281,515).

Further, as dyes forming a J-band, the dyes described in Example 5 of US Pat. Nos. 5,510,236 and 3,871,887, JP-A-2-96131, and JP-A-59-48753 are disclosed. Can be preferably used in the present invention.

These sensitizing dyes may be used alone.
Two or more kinds may be used in combination. In particular, combinations of sensitizing dyes are frequently used for supersensitization. Along with the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization and substances exhibiting supersensitization are
Research Disclosure Volume 176 17643 (Issued December 1978) 2
Section J on page 3, IV, or JP-B-49-25500, 43-4933
And JP-A-59-19032 and JP-A-59-192242.

The sensitizing dyes used in the present invention may be used in combination of two or more. To add sensitizing dyes to a silver halide emulsion, they may be directly dispersed in the emulsion,
Or water, methanol, ethanol, propanol,
Acetone, methyl cellosolve, 2,2,3,3-tetrafluoropropanol, 2,2,2-trifluoroethanol, 3-methoxy-1-propanol, 3-methoxy-1-butanol, 1-
It may be added to the emulsion by dissolving it in a solvent such as methoxy-2-propanol or N, N-dimethylformamide alone or in a mixed solvent.

As disclosed in US Pat. No. 3,469,987, a dye is dissolved in a volatile organic solvent, and this solution is dispersed in water or a hydrophilic colloid. Method of adding into the inside, Japanese Patent Publication No. 44-23389,
As disclosed in JP-A-44-27555 and JP-A-57-22091, the dye is dissolved in an acid and this solution is added to the emulsion, or an acid or base is added to the emulsion as an aqueous solution in the presence of an acid or base. U.S. Pat.Nos. 3,822,135 and 4,006,025
JP-A-53-102733 and JP-A-58-105141 discloses a method of adding an aqueous solution or a colloidal dispersion in the presence of a surfactant to an emulsion as disclosed in JP-A-53-102733 and JP-A-58-105141. A method of directly dispersing a dye in a hydrophilic colloid and adding the dispersion to an emulsion as described in
As disclosed in JP-A-51-74624, a method in which a dye is dissolved using a compound that causes a red shift, and this solution is added to an emulsion can also be used. Also, ultrasonic waves can be used for dissolution.

The sensitizing dye used in the present invention may be added to the silver halide emulsion of the present invention at any stage of the emulsion preparation which has been found to be useful. For example, U.S. Pat.Nos. 2,735,766 and 3,628,96
No. 4, No. 4,183,756, No. 4,225,666, JP-A-58
As disclosed in the specifications of JP-A-184142, JP-A-60-196749, etc., the chemical ripening is carried out before the step of forming silver halide grains and / or before desalting, during the desilvering step and / or after desalting. Before the start of the process, as disclosed in the specification of JP-A-58-113920, etc., immediately before or during the chemical ripening, during the process, after the chemical ripening, the emulsion is coated before the coating. Any time before, it may be added in the process. Also, U.S. Pat.No.4,225,666, JP-A-58-762
As disclosed in the specification such as No. 9 or the like, the same compound may be used alone or in combination with a compound having a heterogeneous structure, for example, during the particle formation step and during the chemical ripening step or after the completion of the chemical ripening, The compound may be added in portions such as before aging or during the process and after completion, or may be added by changing the kind of compound to be added and the combination of compounds.

The amount of the sensitizing dye used in the present invention may be a desired amount according to the performance such as sensitivity and fog.
The amount is preferably from 10 ^-6 to 1 mol, more preferably from 10 ^-4 to 10 ^-1 , per mol of silver halide in the photosensitive layer.

In the present invention, the silver halide emulsion and / or
Alternatively, the organic silver salt can be further protected against the formation of additional fog by antifoggants, stabilizers and stabilizer precursors, and can be stabilized against reduced sensitivity during storage in inventory. Suitable antifoggants, stabilizers and stabilizer precursors which can be used alone or in combination are the thiazonium salts described in U.S. Pat.Nos. 2,131,038 and 2,694,716;
No. 4,605, azaindene, U.S. Pat.No. 2,728,663, mercury salt, U.S. Pat.
Nitroindazole, the polyvalent metal salt described in U.S. Pat.No. 2,839,405, the thyuronium salt described in U.S. Pat.
Palladium, platinum and gold salts described in U.S. Pat.
Halogen-substituted organic compounds described in U.S. Patent Nos. 8,665 and 4,442,202; U.S. Patents 4,128,557 and 4,137,079
No. 4,138,365 and 4,459,350 and the phosphorus compounds described in U.S. Pat. No. 4,411,985.

The antifoggant preferably used in the present invention is an organic halide, for example, as described in JP-A-50-119624.
No. 50-120328, No. 51-121332, No. 54-58022,
56-70543, 56-99335, 59-90842, 61-129
No. 642, No. 62-129845, JP-A-6-208191, No. 7-5621
Nos. 7-2781 and 8-15809; U.S. Patent 5,340,712
No. 5,369,000 and 5,464,737.

The antifoggant of the present invention may be added by any method such as a solution, a powder and a dispersion of solid fine particles. The dispersion of the solid fine particles is carried out by a known fine means (for example, ball mill, vibrating ball mill, sand mill, colloid mill, jet mill, roller mill, etc.). When dispersing the solid fine particles, a dispersing aid may be used.

Although not required to practice the present invention,
It may be advantageous to add a mercury (II) salt as an antifoggant to the emulsion layer. Preferred mercury (II) salts for this purpose are
Mercury acetate and mercury bromide. The amount of mercury used in the present invention is preferably 1 nmol to 1 mmol, more preferably 10 nmol to 100 μm per 1 mol of coated silver.
Range of moles.

The photothermographic material of the present invention may contain benzoic acids for the purpose of increasing the sensitivity and preventing fog. The benzoic acids of the present invention may be any benzoic acid derivative, but examples of preferred structures include those described in U.S. Pat.
No. 9, No. 4, 152, 160, Japanese Patent Application No. 8-151242, No. 8-151241
And compounds described in JP-A-8-98051. The benzoic acid of the present invention may be added to any part of the light-sensitive material. . The benzoic acids of the present invention may be added at any time during the preparation of the coating solution, and when they are added to the organic silver salt-containing layer, they may be added at any time from the preparation of the organic silver salt to the preparation of the coating solution. It is preferable after salt preparation and immediately before application. The benzoic acid of the present invention may be added by any method such as powder, solution, and fine particle dispersion. Further, it may be added as a solution mixed with other additives such as a sensitizing dye, a reducing agent and a color tone agent. The benzoic acid of the present invention may be added in any amount, but is preferably from 1 μmol to 2 mol, more preferably from 1 mmol to 0.5 mol, per mol of silver.

In the present invention, a mercapto compound, a disulfide compound, and a thione compound are contained in order to control development by suppressing or accelerating development, to improve spectral sensitization efficiency, to improve storage stability before and after development, and the like. be able to.

When a mercapto compound is used in the present invention, it may be of any structure, but may be any of Ar-SM, Ar-SSA
Those represented by r are preferred. In the formula, M is a hydrogen atom or an alkali metal atom, and Ar is an aromatic ring group or a condensed aromatic ring group having one or more nitrogen, sulfur, oxygen, selenium or tellurium atoms. Preferably, the heteroaromatic ring in such a group is benzimidazole, naphthimidazole, benzothiazole, naphthothiazole, benzoxazole, naphthoxazole, benzoselenazole, benzotellazole, imidazole, oxazole, pyrazole, triazole, thiadiazole, tetrazole, triazine, Pyrimidine, pyridazine, pyrazine, pyridine, purine, quinoline or quinazolinone. Such heteroaromatic rings include, for example, halogens (eg, Br and Cl), hydroxy, amino,
Carboxy, alkyl (eg, one or more carbon atoms,
Preferably those having 1 to 4 carbon atoms) and alkoxy (for example one or more carbon atoms, preferably 1 to 4 carbon atoms).
) May be selected from the substituent group consisting of those having from 4 to 4 carbon atoms). As mercapto-substituted heteroaromatic compounds, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-mercapto-5-methylbenzimidazole, 6-ethoxy-2-mercaptobenzothiazole,
2,2'-dithiobis-benzothiazole, 3-mercapto-
1,2,4-triazole, 4,5-diphenyl-2-imidazolethiol, 2-mercaptoimidazole, 1-ethyl-2-
Mercaptobenzimidazole, 2-mercaptoquinoline, 8-mercaptopurine, 2-mercapto-4 (3H) -quinazolinone, 7-trifluoromethyl-4-quinolinethiol,
2,3,5,6-tetrachloro-4-pyridinethiol, 4-amino
-6-hydroxy-2-mercaptopyrimidine monohydrate, 2-amino-5-mercapto-1,3,4-thiadiazole,
3-Amino-5-mercapto-1,2,4-triazole, 4-hydrochiroxy-2-mercaptopyrimidine, 2-mercaptopyrimidine, 4,6-diamino-2-mercaptopyrimidine, 2-mercapto-4-methylpyrimidinehydro Chloride, 3-mercapto-5-phenyl-1,2,4-triazole, 2-mercapto
-4-phenyloxazole and the like, but the present invention is not limited to these.

The addition amount of these mercapto compounds is preferably in the range of 0.001 to 1.0 mol per mol of silver in the emulsion layer, more preferably 0.01 to 1.0 mol per mol of silver.
The amount is 0.3 mol.

In the photosensitive layer according to the invention, a polyhydric alcohol (for example, US Pat. No. 2,963) is used as a plasticizer and a lubricant.
Glycerin and diols of the type described in U.S. Pat. No. 0,404), fatty acids or esters described in U.S. Pat. Nos. 2,588,765 and 3,121,060, and silicone resins described in British Patent No. 955,061.

In the photothermographic material of the present invention, the following formulas (A) to (C) are used as a super-high contrast agent for forming a super-high contrast image.
A substituted alkene derivative, a substituted isoxazole derivative and a specific acetal compound represented by the following formula (1) can be used. Formulas (A), (B), and (C) will be described.

[0140]

Embedded image

In the formula (A), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent, and Z represents an electron-withdrawing group or a silyl group. In the formula (A), R ¹ and Z, R ² and R ³ , R ¹ and R ² , or R ³ and Z may be bonded to each other to form a cyclic structure. In the formula (B), R ⁴ represents a substituent. In the formula (C), X and Y each independently represent a hydrogen atom or a substituent, and A and B each independently represent an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group, or a heterocyclic ring. Represents an oxy group, a heterocyclic thio group, or a heterocyclic amino group. In the formula (C), X and Y or A and B may be bonded to each other to form a cyclic structure.

The compound represented by the formula (A) will be described in detail.

In the formula (A), R ¹ , R ² and R ³ each independently represent a hydrogen atom or a substituent, and Z represents an electron-withdrawing group or a silyl group. In the formula (A), R ¹ and Z, R ² and R ³ , R ¹ and R ² , or R ³ and Z may be bonded to each other to form a cyclic structure.

When R ¹ , R ² , and R ³ represent a substituent, examples of the substituent include a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom) and an alkyl group (an aralkyl group, a cycloalkyl group). An alkyl group, an active methine group, etc.), an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group (including an N-substituted nitrogen-containing heterocyclic group), and a heterocyclic group containing a quaternized nitrogen atom ( For example, a pyridinio group), an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a carboxy group or a salt thereof, an imino group, an imino group substituted by an N atom, a thiocarbonyl group, a sulfonylcarbamoyl group, an acylcarbamoyl group, Famoylcarbamoyl group, carbazoyl group, oxalyl group, oxamoyl group, cyano group, thiocarbamoyl group, A droxy group or a salt thereof, an alkoxy group (including a group repeatedly containing an ethyleneoxy group or a propyleneoxy group unit), an aryloxy group, a heterocyclic oxy group, an acyloxy group, an (alkoxy or aryloxy) carbonyloxy group, and a carbamoyloxy group , Sulfonyloxy group, amino group, (alkyl, aryl, or heterocycle) amino group, acylamino group, sulfonamide group, ureido group, thioureido group, imide group, (alkoxy or aryloxy)
Carbonylamino group, sulfamoylamino group, semicarbazide group, thiosemicarbazide group, hydrazino group, 4
Grade ammonio group, oxamoylamino group, (alkyl or aryl) sulfonyluureido group, acylureido group, acylsulfamoylamino group, nitro group, mercapto group, (alkyl, aryl, or heterocycle)
Thio group, acylthio group, (alkyl or aryl) sulfonyl group, (alkyl or aryl) sulfinyl group, sulfo group or a salt thereof, sulfamoyl group, acylsulfamoyl group, sulfonylsulfamoyl group or a salt thereof, phosphoryl group, phosphorus Examples include groups having an acid amide or phosphate structure, silyl groups, stannyl groups, and the like.

These substituents may be further substituted with these substituents.

The electron-withdrawing group represented by Z in the formula (A) is a substituent whose Hammett's substituent constant σp can take a positive value, specifically, a cyano group, an alkoxycarbonyl Group, aryloxycarbonyl group, carbamoyl group, imino group, imino group substituted with an N atom, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, halogen atom,
A perfluoroalkyl group, a perfluoroalkaneamide group, a sulfonamide group, an acyl group, a formyl group, a phosphoryl group, a carboxy group (or a salt thereof), a sulfo group (or a salt thereof), a heterocyclic group, an alkenyl group, an alkynyl group, Examples include an acyloxy group, an acylthio group, a sulfonyloxy group, and an aryl group substituted with these electron-withdrawing groups. Here, the heterocyclic group is a saturated or unsaturated heterocyclic group, for example, a pyridyl group, a quinolyl group,
Examples thereof include a quinoxalinyl group, a pyrazinyl group, a benzotriazolyl group, an imidazolyl group, a benzimidazolyl group, a hydantoin-1-yl group, a succinimide group, and a phthalimido group.

The electron-withdrawing group represented by Z in the formula (A) may further have a substituent, and the substituent includes R ¹ , R ² and R ^{3 in the} formula (A). The same substituents as the substituents that may be present when representing the substituents are exemplified.

In the formula (A), R ¹ and Z, R ² and R ³ , R ¹
And R ² , or R ³ and Z may be bonded to each other to form a cyclic structure. The cyclic structure formed at this time is a non-aromatic carbon ring or a non-aromatic hetero ring. is there.

Next, the preferred range of the compound represented by the formula (A) will be described.

In the formula (A), the silyl group represented by Z is preferably a trimethylsilyl group, a t-butyldimethylsilyl group, a phenyldimethylsilyl group, a triethylsilyl group, a triisopropylsilyl group, a trimethylsilyldimethylsilyl group. And so on.

In the formula (A), the electron-withdrawing group represented by Z is preferably a group having a total number of carbon atoms of 0 to 30, that is, a cyano group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, Carbonyl group,
Imino group, imino group substituted by N atom, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, perfluoroalkyl group, acyl group, formyl group, phosphoryl group, acyloxy group, acylthio group, or any electron withdrawing And a phenyl group substituted with a functional group, more preferably a cyano group, an alkoxycarbonyl group, a carbamoyl group, an imino group, a sulfamoyl group,
An alkylsulfonyl group, an arylsulfonyl group, an acyl group, a formyl group, a phosphoryl group, a trifluoromethyl group, or a phenyl group substituted with an arbitrary electron-withdrawing group, and particularly preferably a cyano group, a formyl group, an acyl group. , An alkoxycarbonyl group, an imino group or a carbamoyl group.

The group represented by Z in the formula (A) is more preferably an electron-withdrawing group.

In the formula (A), the substituent represented by R ¹ , R ² and R ³ is preferably a group having a total carbon number of 0 to 30, specifically, Z in the above formula (A). Groups having the same meanings as the electron-withdrawing groups represented, and alkyl and hydroxy groups
(Or its salt), mercapto group (or its salt), alkoxy group, aryloxy group, heterocyclic oxy group, alkylthio group, arylthio group, heterocyclic thio group, amino group, alkylamino group, arylamino group, heterocyclic Examples include an amino group, a ureido group, an acylamino group, a sulfonamide group, and a substituted or unsubstituted aryl group.

In the formula (A), R ¹ is preferably an electron-withdrawing group, an aryl group, an alkylthio group, an alkoxy group, an acylamino group, a hydrogen atom or a silyl group.

When R ¹ represents an electron-withdrawing group, the following groups having preferably 0 to 30 carbon atoms in total, ie, a cyano group, a nitro group, an acyl group, a formyl group, an alkoxycarbonyl group,
An aryloxycarbonyl group, a thiocarbonyl group, an imino group, an imino group substituted with an N atom, an alkylsulfonyl group, an arylsulfonyl group, a carbamoyl group, a sulfamoyl group, a trifluoromethyl group, a phosphoryl group, a carboxy group (or a salt thereof), Or a saturated or unsaturated heterocyclic group, and a cyano group, an acyl group, a formyl group, an alkoxycarbonyl group, a carbamoyl group, an imino group, an imino group substituted with an N atom, a sulfamoyl group, a carboxy group (or a salt thereof) Or a saturated or unsaturated heterocyclic group. Particularly preferred are a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, and a saturated or unsaturated heterocyclic group.

When R ¹ represents an aryl group, it is preferably a substituted or unsubstituted phenyl group having 6 to 30 carbon atoms in total, and examples of the substituent include arbitrary substituents.
Among them, an electron-withdrawing substituent is preferable.

In formula (A), R ¹ is more preferably an electron-withdrawing group or an aryl group.

In the formula (A), the substituents represented by R ² and R ³ are preferably, specifically, groups having the same meaning as the electron-withdrawing group represented by Z in the above formula (A), and alkyl groups. , A hydroxy group (or a salt thereof), a mercapto group (or a salt thereof), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group, an alkylamino group, an anilino group, Examples include a heterocyclic amino group, an acylamino group, and a substituted or unsubstituted phenyl group.

In formula (A), R ² and R ³ are more preferably when one of them is a hydrogen atom and the other is a substituent. Preferably as the substituent, an alkyl group, a hydroxy group (or a salt thereof), a mercapto group (or a salt thereof), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, an amino group Group, an alkylamino group, an anilino group, a heterocyclic amino group, an acylamino group (particularly a perfluoroalkaneamide group), a sulfonamide group, a substituted or unsubstituted phenyl group, or a heterocyclic group,
More preferably a hydroxy group (or a salt thereof), a mercapto group (or a salt thereof), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, or a heterocyclic group, Preferably a hydroxy group (or a salt thereof), an alkoxy group,
Or a heterocyclic group.

In formula (A), it is also preferred that Z and R ¹ , or R ² and R ³ form a cyclic structure.
The cyclic structure formed in this case is a non-aromatic carbon ring or a non-aromatic hetero ring, preferably 5 to 7 members.
Having a total carbon number of 1 to 4 including substituents.
0, more preferably 3 to 30.

Among the compounds represented by the formula (A), one of the more preferable ones is that Z represents a cyano group, formyl group, acyl group, alkoxycarbonyl group, imino group or carbamoyl group, and R ¹ is Represents an electron-withdrawing group or an aryl group, and one of R ^{2 and} R ³ is a hydrogen atom;
The other is a compound representing a hydroxy group (or a salt thereof), a mercapto group (or a salt thereof), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic thio group, or a heterocyclic group. .

Further, among the compounds represented by the formula (A), one of the particularly preferable compounds is that Z and R ^{1 form a} non-aromatic 5- to 7-membered cyclic structure, and R ² Or one of R ³ is a hydrogen atom and the other is a hydroxy group (or a salt thereof), a mercapto group (or a salt thereof), an alkoxy group, an aryloxy group, a heterocyclic oxy group, an alkylthio group, an arylthio group, a heterocyclic group. It is a compound that represents a thio group or a heterocyclic group. At this time, the Z to form a cyclic structure of the non-aromatic with R ^1, an acyl group, a carbamoyl group, an oxycarbonyl group, a thiocarbonyl group, a sulfonyl group, and the like are preferable, and as R ¹ is acyl group,
A carbamoyl group, an oxycarbonyl group, a thiocarbonyl group, a sulfonyl group, an imino group, an imino group substituted with an N atom, an acylamino group, a carbonylthio group, and the like are preferable.

Next, the compound represented by the formula (B) will be described.

In the formula (B), examples of the substituent represented by R ⁴ include the same as those described for the substituents R ^{1 to} R ^{3 in} the formula (A).

In the formula (B), the substituent represented by R ⁴ is preferably an electron-withdrawing group or an aryl group.
When R ⁴ represents an electron-withdrawing group, it preferably has a total carbon number of 0.
To 30 or less of the following groups: cyano group, nitro group, acyl group, formyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylsulfonyl group, arylsulfonyl group, carbamoyl group, sulfamoyl group, trifluoromethyl group, phosphoryl Group, imino group, or a saturated or unsaturated heterocyclic group, and further a cyano group, an acyl group, a formyl group, an alkoxycarbonyl group,
A carbamoyl group, a sulfamoyl group, an alkylsulfonyl group, an arylsulfonyl group, and a heterocyclic group are preferred.
Particularly preferred are a cyano group, a formyl group, an acyl group, an alkoxycarbonyl group, a carbamoyl group, and a heterocyclic group.

When R ⁴ represents an aryl group, it is preferably a substituted or unsubstituted phenyl group having a total of 0 to 30 carbon atoms, and the substituent is represented by R ¹ , R ² , R ³ of the formula (A). When represents a substituent, the same as those described as the substituent can be mentioned.

In the formula (B), R ⁴ is particularly preferably a cyano group, an alkoxycarbonyl group, a carbamoyl group,
A heterocyclic group or a substituted or unsubstituted phenyl group, most preferably a cyano group, a heterocyclic group, or an alkoxycarbonyl group.

Next, the compound represented by the formula (C) will be described in detail.

In the formula (C), X and Y each independently represent a hydrogen atom or a substituent, and A and B each independently represent an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group. ,
Represents a heterocyclic thio group, a heterocyclic oxy group, or a heterocyclic amino group. X and Y or A and B may be bonded to each other to form a cyclic structure.

The substituents represented by X and Y in the formula (C) are the same as those described for the substituents R ^{1 to} R ^{3 in} the formula (A). Specifically, alkyl groups (including perfluoroalkyl groups, trichloromethyl groups, etc.), aryl groups, heterocyclic groups, halogen atoms, cyano groups, nitro groups, alkenyl groups, alkynyl groups, acyl groups, formyl groups, alkoxy groups Carbonyl group, aryloxycarbonyl group, imino group, imino group substituted with an N atom, carbamoyl group, thiocarbonyl group, acyloxy group, acylthio group, acylamino group, alkylsulfonyl group, arylsulfonyl group, sulfamoyl group, phosphoryl group, carboxy Group (or its salt), sulfo group (or its salt), hydroxy group (or its salt), mercapto group (or its salt), alkoxy group, aryloxy group, heterocyclic oxy group, alkylthio group, arylthio group, hetero group Ring thio group, amino group, alkylami Group, anilino group, heterocyclic amino group, a silyl group, and the like.

These groups may further have a substituent. X and Y may be bonded to each other to form a cyclic structure, and the cyclic structure formed in this case may be a non-aromatic carbon ring or a non-aromatic hetero ring. .

The substituent represented by X and Y in the formula (C) is preferably a group having a total of 1 to 40 carbon atoms, more preferably a group having a total of 1 to 30 carbon atoms, and is a cyano group, an alkoxycarbonyl group, Aryloxycarbonyl group, carbamoyl group, imino group, imino group substituted with N atom, thiocarbonyl group, sulfamoyl group, alkylsulfonyl group, arylsulfonyl group, nitro group, perfluoroalkyl group, acyl group, formyl group, phosphoryl group , An acylamino group, an acyloxy group, an acylthio group, a heterocyclic group, an alkylthio group, an alkoxy group, or an aryl group.

In the formula (C), X and Y are more preferably cyano, nitro, alkoxycarbonyl, carbamoyl, acyl, formyl, acylthio, acylamino, thiocarbonyl, sulfamoyl,
An alkylsulfonyl group, an arylsulfonyl group, an imino group, an imino group substituted with an N atom, a phosphoryl group, a trifluoromethyl group, a heterocyclic group, or a substituted phenyl group, and particularly preferably a cyano group or an alkoxycarbonyl group , A carbamoyl group, an alkylsulfonyl group,
An arylsulfonyl group, an acyl group, an acylthio group, an acylamino group, a thiocarbonyl group, a formyl group, an imino group, an imino group substituted with an N atom, a heterocyclic group, or a phenyl group substituted with any electron-withdrawing group; is there.

It is also preferable that X and Y combine with each other to form a non-aromatic carbon ring or a non-aromatic hetero ring. At this time, the cyclic structure to be formed is preferably a 5- to 7-membered ring, and has a total carbon number of 1 to 40, more preferably 3 to 7 members.
30 is preferred. X and Y forming a cyclic structure include an acyl group, a carbamoyl group, an oxycarbonyl group,
Preferred are a thiocarbonyl group, a sulfonyl group, an imino group, an imino group substituted with an N atom, an acylamino group, a carbonylthio group and the like.

In the formula (C), A and B each independently represent an alkoxy group, an alkylthio group, an alkylamino group, an aryloxy group, an arylthio group, an anilino group,
Represents a heterocyclic thio group, a heterocyclic oxy group, or a heterocyclic amino group, which may be bonded to each other to form a cyclic structure.

In the formula (C), the groups represented by A and B are
It is preferably a group having a total of 1 to 40 carbon atoms, more preferably a group having a total of 1 to 30 carbon atoms, and may further have a substituent.

In formula (C), A and B more preferably combine with each other to form a cyclic structure. The cyclic structure formed at this time is preferably a 5- to 7-membered non-aromatic hetero ring, and preferably has a total carbon number of 1 to 40, and more preferably 3 to 30. In this case, an example in which A and B are linked (-AB-) is, for example, -O- (CH
2) 2-O-, -O- (CH2) 3-O-, -S- (C
H2) 2-S-, -S- (CH2) 3-S-, -Sp
h-S-, -N (CH3)-(CH2) 2-O-, -N
(CH3)-(CH2) 2-S-,-O- (CH2) 2
-S-, -O- (CH2) 3-S-, -N (CH3)-
ph-O-, -N (CH3) -ph-S-, -N (p
h)-(CH2) 2-S- and the like.

The compounds represented by the formulas (A) to (C) used in the present invention may have incorporated therein an adsorptive group that adsorbs to silver halide. Such adsorbing groups include alkylthio, arylthio, thiourea,
U.S. Pat. Nos. 4,385,108 and 4,459, such as a thioamide group, a mercapto heterocyclic group and a triazole group;
347, JP-A-59-195233, and JP-A-59-20
Nos. 0231, 59-201045, 59-201
Nos. 046, 59-201047, 59-2010
No. 48, 59-201049, JP-A-61-170
No. 733, No. 61-270744, No. 62-948
Nos. 63-234244 and 63-234245
And groups described in JP-A-63-234246. These adsorbing groups to silver halide may be precursors. Examples of such a precursor include groups described in JP-A-2-285344.

The compounds represented by the formulas (A) to (C) used in the present invention incorporate therein a ballast group or a polymer commonly used in immobile photographic additives such as couplers. It may be something. Particularly, those incorporating a ballast group are one of preferred examples of the present invention. The ballast group is a group having a carbon number of 8 or more and relatively inactive to photographic properties. You can choose from. Examples of the polymer include those described in JP-A-1-100530.

The compounds represented by the formulas (A) to (C) used in the present invention contain a cationic group (specifically, a group containing a quaternary ammonium group, or a quaternized group). A nitrogen-containing heterocyclic group containing a nitrogen atom), a group containing a repeating unit of an ethyleneoxy group or a propyleneoxy group, an (alkyl, aryl, or heterocyclic) thio group,
Alternatively, it may contain a dissociable group that can be dissociated by a base (carboxy group, sulfo group, acylsulfamoyl group, carbamoylsulfamoyl group, etc.). Particularly, a group containing a group containing a repeating unit of an ethyleneoxy group or a propyleneoxy group or a group containing an (alkyl, aryl, or heterocyclic) thio group is one of preferred examples of the present invention. Specific examples of these groups include, for example, JP-A-7-234471 and JP-A-5-333466.
JP-A-6-19032, JP-A-6-19031
JP-A-5-45761, U.S. Pat. No. 4,994,365.
No. 4,988,604, JP-A-3-25924.
No. 0, JP-A-7-5610, JP-A-7-244348
And the compounds described in German Patent No. 4006032.

Next, specific examples of the compounds represented by the formulas (A) to (C) used in the present invention are shown below. However, the present invention is not limited to the following compounds.

[0182]

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[0183]

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[0184]

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[0185]

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[0186]

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[0187]

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[0188]

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[0189]

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[0190]

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The compounds represented by the formulas (A) to (C) used in the present invention may be water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol,
It can be used by dissolving in fluorinated alcohol), ketones (acetone, methyl ethyl ketone), dimethylformamide, dimethylsulfoxide, methylcellosolve and the like.

Further, by a well-known emulsification dispersion method, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate or an auxiliary solvent such as ethyl acetate or cyclohexanone is used for dissolution, An emulsified dispersion can be prepared and used. Alternatively, by a method known as a solid dispersion method, the powder of the compound represented by Formulas (A) to (C) of the present invention is dispersed in a suitable solvent such as water by a ball mill, a colloid mill, or ultrasonic waves. Can be used.

The compounds represented by the formulas (A) to (C) used in the present invention may be used in combination with a layer on an image forming layer side with respect to a support,
That is, it may be added to the image forming layer or any other layer on the layer side, but is preferably added to the image forming layer or a layer adjacent thereto.

The addition amount of the compounds represented by the formulas (A) to (C) of the present invention is preferably 1 × 10 ⁻⁶ to 1 mol per 1 mol of silver, and 1 × 10 ^{−5 to} 5 × 10 5 ^-1 mol is more preferred, and 2 × 10 ^-5 to 2 × 10 ^-1 mol is most preferred.

The compounds represented by the formulas (A) to (C) can be easily synthesized by known methods. For example, US Pat. No. 5,545,515 and US Pat.
No. 9, U.S. Pat. No. 5,654,130, International Patent WO-97
/ 34196, or Japanese Patent Application No. 9-354107.
The compounds can be synthesized with reference to the methods described in Japanese Patent Application Nos. 9-309813 and 9-272002.

The compounds represented by the formulas (A) to (C) used in the present invention may be used alone or in combination of two or more. In addition to the above, US Pat.
No. 515, US Pat. No. 5,635,339, US Pat.
No. 4,130, International Patent WO-97 / 34196, compounds described in U.S. Pat. No. 5,686,228, or Japanese Patent Application Nos. 8-279962 and 9-228881;
Japanese Patent Application No. 9-273935, Japanese Patent Application No. 9-354107
, Japanese Patent Application No. 9-309813, Japanese Patent Application No. 9-29617
4, Japanese Patent Application No. 9-282564, Japanese Patent Application No. 9-2720
02, Japanese Patent Application No. 9-272003, Japanese Patent Application No. 9-332
No. 388 may be used in combination.

Further, in the present invention, Japanese Patent Application No. 9-16 / 1990
No. 6628, Japanese Patent Application No. 8-279957, Japanese Patent Application No. 9-2
The hydrazine derivatives described in No. 40511 can also be used in combination. Further, the following hydrazine derivatives can be used in combination. That is,
A compound represented by (Chemical Formula 1) described in No. 77138, specifically, a compound described on pages 3 and 4 of the same publication. Tokuhei 6-
Compounds represented by the general formula (I) described in No. 93082, specifically, compounds 1 to 38 described on pages 8 to 18 of the same publication. Compounds represented by formulas (4), (5) and (6) described in JP-A-6-230497, specifically, compound 4- described on pages 25 and 26 of the same publication. 1 to 4-10, compounds 5-1 to 5-42 described on pages 28 to 36, and compounds 6-1 to 6-7 described on pages 39 and 40. JP-A-6-289520
Compounds represented by the general formulas (1) and (2) described in the above publications, specifically, the compounds 1-1) to 1-17) and 2-1 described on pages 5 to 7 of the same publication. ). JP-A-6-31
Compounds represented by (Chemical Formula 2) and (Chemical Formula 3) described in No. 3936, specifically, compounds described on pages 6 to 19 of the same publication. Compounds represented by (Chemical Formula 1) described in JP-A-6-313951, specifically, compounds described on pages 3 to 5 of the same. Compounds represented by formula (I) described in JP-A-7-5610, specifically, compounds I-1 to I-38 described on pages 5 to 10 of the same. Compounds represented by general formula (II) described in JP-A-7-77783, specifically, compounds II-1 to II-10 described on pages 10 to 27 of the same publication
2. Compounds represented by formulas (H) and (Ha) described in JP-A-7-104426, specifically, compounds H-1 to H-44 described on pages 8 to 15 of the same publication. A compound described in EP 713131A, which has an anionic group or a nonionic group that forms an intramolecular hydrogen bond with a hydrogen atom of hydrazine in the vicinity of a hydrazine group. Particularly, a compound represented by the general formula (A): A compound represented by the formula (B), the general formula (C), the general formula (D), the general formula (E), or the general formula (F).
-1 to N-30. Compounds represented by the general formula (1) described in European Patent 713131A, and specifically, compounds D-1 to D-55 described in the publication.

Further, “Known Techniques (1 to
207) ”(published by Aztec) on pages 25 to 34. Compounds D-2 and D-39 of JP-A-62-86354 (pages 6 to 7).

These hydrazine derivatives are dissolved in water or a suitable organic solvent such as alcohols (methanol, ethanol, propanol, fluorinated alcohol), ketones (acetone, methylethylketone), dimethylformamide, dimethylsulfoxide, methylcellosolve and the like. Can be used.

Further, by a well-known emulsification dispersion method, an oil such as dibutyl phthalate, tricresyl phosphate, glyceryl triacetate or diethyl phthalate, or an auxiliary solvent such as ethyl acetate or cyclohexanone is used to dissolve and dissolve. An emulsified dispersion can be prepared and used. Alternatively, a powder of a hydrazine derivative can be dispersed in water by a ball mill, a colloid mill, or an ultrasonic wave by a method known as a solid dispersion method and used.

These hydrazine derivatives may be added to the layer on the image forming layer side with respect to the support, that is, to the image forming layer or any other layer on the layer side, but may be added to the image forming layer or a layer adjacent thereto. It is preferred to add.

The addition amount of these hydrazine derivatives is preferably 1 × 10 ⁻⁶ to 1 mol per 1 mol of silver, and 1 × 10 ⁻⁵ to 1 × 10 ⁻⁵ .
5 × 10 ^-1 mol is more preferred, and 2 × 10 ^-5 to 2 × 10
^-1 mole is most preferred.

Further, acrylonitriles described in US Pat. No. 5,545,515, specifically, CN-1 to CN-13 and the like can be used as a super-high contrast agent.

Further, the present invention provides a method for forming a super-high contrast image.
A high contrast accelerator can be used in combination with the above-mentioned super-high contrast agent. For example, the amine compounds described in U.S. Patent No. 5,545,505, specifically AM-1 to AM-5, and 5,545,507
, Specifically HA-1 to HA
Hydrazine compounds described in US Pat. No. 5,558,983, specifically CA-1 to CA-6, and onium salts described in Japanese Patent Application No. 8-132836, specifically A-1 to A -42, B-1 to B-
27, C-1 to C-14 and the like can be used.

The method for synthesizing, adding, and adding the above-mentioned super-high contrast agent and these high-contrast accelerators can be carried out as described in each of the cited patents.

The light-sensitive material of the present invention may be provided with a surface protective layer for the purpose of preventing adhesion of an image forming layer.
Any anti-adhesion material may be used as the surface protective layer. Examples of anti-adhesion materials include waxes, silica particles, styrene-containing elastomeric block copolymers (eg, styrene-butadiene-styrene, styrene
-Isoprene-styrene), cellulose acetate, cellulose acetate butyrate, cellulose propionate and mixtures thereof.

In the emulsion layer or the protective layer of the emulsion layer in the present invention, in addition to the colored layer of the present invention, or in the case where these layers are the colored layers of the present invention, US Pat.
Nos. 921, 2,274,782, 2,527,583 and 2,95
Light absorbing materials and filter dyes as described in 6,879 can be used. Further, a dye can be mordant as described in, for example, US Pat. No. 3,282,699. The amount of the filter dye used is preferably from 0.1 to 3 at the exposure wavelength, particularly preferably from 0.2 to 1.5.

In the emulsion layer or the protective layer of the emulsion layer in the present invention, a matting agent such as starch, titanium dioxide, zinc oxide, silica, US Pat. Nos. 2,992,101 and 2,701,
Polymer beads, including beads of the type described in No. 245, can be included. The matte degree of the emulsion surface may be any value as long as stardust failure does not occur, but the Beck smoothness is preferably 200 seconds or more and 10,000 seconds or less, particularly 30 seconds.
It is preferably from 0 seconds to 10,000 seconds.

The photothermographic emulsion of the present invention is contained in one or more layers provided on a support. One layer must include the organic silver salt, silver halide, developer (reducing agent) and binder, and optional additional materials such as toning agents, coating aids and other auxiliaries. The two-layer construction is that the first emulsion layer (usually the layer adjacent to the support) contains an organic silver salt and silver halide, and the second layer or both layers do not contain some other components. No. However, a two-layer construction comprising a single emulsion layer containing all components and a protective topcoat is also contemplated. The construction of the multicolor photothermographic material may include a combination of these two layers for each color, and US Pat. No. 4,708,92
As described in No. 8, all components may be contained in a single layer. In the case of multi-dye, multi-color light-sensitive photothermographic materials, each emulsion layer generally employs a functional or non-functional barrier layer between the emulsion layers as described in U.S. Pat. No. 4,460,681. Thereby, they are kept distinct from each other. .

The photosensitive layer of the present invention may be an irradiation prevention layer at the same time. Further, the photosensitive layer of the present invention can contain various dyes from the viewpoint of improving color tone and preventing irradiation. These photosensitive layers may be the colored layers of the present invention, may not contain the photoradical generator of the present invention, and may further include these layers. The dye used in the photosensitive layer of the present invention may be any dye, for example, pyrazoloazole dye, anthraquinone dye, azo dye, azomethine dye, oxonol dye, carbocyanine dye, styryl dye, triphenylmethane dye, indoaniline dye,
And indophenol dyes. Preferred dyes used in the present invention include anthraquinone dyes (for example, compounds 1 to 9 described in JP-A-5-341441, JP-A-5-1651).
No. 47, such as compounds 3-6 to 18 and 3-23 to 38), azomethine dyes (such as compounds 17 to 47 described in JP-A-5-341441), and indoaniline dyes (e.g., those described in JP-A-5-289227). Compounds 11 to 19, compound 47 described in JP-A-5-341441,
And azo dyes (compounds 10 to 16 described in JP-A-5-341441). As a method for adding these dyes, any method such as a solution, an emulsion, a solid fine particle dispersion, and a state in which the dye is mordanted with a polymer mordant may be used. The amount of these compounds used is determined depending on the desired absorption amount, but it is generally preferable to use them in an amount of 1 μg or more and 1 g or less per 1 m ² of the photographic material.

In the present invention, the antihalation layer can be provided on the side farther from the light source than the photosensitive layer.
The antihalation layer has a maximum absorption in the desired wavelength range.
It is preferably 0.3 or more and 2 or less, more preferably absorption at an exposure wavelength of 0.5 or more and 2 or less, and absorption in the visible region after processing is preferably 0.001 or more and less than 0.5, and more preferably 0.001 or more. It is preferable that the layer has an optical density of less than 0.3, particularly preferably 0.001 or more and 0.1 or less. In the present invention, an antihalation layer can be provided as a separate layer from the colored layer of the present invention. The antihalation dye used in the layer may be any compound as long as it has the desired absorption in the wavelength range, has a sufficiently low absorption in the visible region after the treatment, and has a desirable absorbance spectrum of the antihalation layer. For example, the following are disclosed, but the present invention is not limited thereto. As a single dye, JP-A-59-56458, JP-A-2-216140, 7-13295
No. 7,114,432, U.S. Pat.
JP-A No. 2-68539, page 13, lower left column, line 1 to page 14, lower left column, line 9; JP-A-3-24539, page 14, lower left column, page 16, lower right column Dyes decolorized in JP-A-52-139136, JP-A-53-132334, JP-A-56-501480
No. 57-16060, No. 57-68831, No. 57-101835, No.
59-182436, JP-A-7-36145, JP-A-7-199409, JP-B-48-33692, JP-B-50-16648, JP-B-2-41734, U.S. Patents 4,088,497, 4,283,487, 4,548,896 ,
No. 5,187,049. When the coloring layer of the present invention is an antihalation layer, the above dye may be used in combination.

The heat-developable photosensitive material of the present invention comprises a support having at least one photosensitive layer (emulsion layer) containing a silver halide emulsion on one side and a back layer on the other side. It is preferably a single-sided photosensitive material.

In the present invention, a matting agent may be added to the single-sided photosensitive material in order to improve transportability. The matting agent is generally fine particles of an organic or inorganic compound insoluble in water. Any matting agent can be used, for example, U.S. Patent Nos. 1,939,213, 2,701,245, and 2,322,037.
No. 3,262,782, No. 3,539,344, No. 3,767,448, etc.
No. 2,192,241, No. 3,257,206, No. 3,370,951, No.
Inorganic matting agents well-known in the art, such as inorganic matting agents described in the specifications such as 3,523,022 and 3,769,020 can be used. For example, specific examples of organic compounds that can be used as a matting agent include polymethyl acrylate, polymethyl methacrylate, polyacrylonitrile, and acrylonitrile as examples of water-dispersible vinyl polymers.
-α-methylstyrene copolymer, polystyrene, styrene-divinylbenzene copolymer, polyvinyl acetate, polyethylene carbonate, polytetrafluoroethylene, etc.Examples of cellulose derivatives such as methylcellulose, cellulose acetate, cellulose acetate propionate, etc. Examples of the derivative preferably include carboxystarch, carboxynitrophenyl starch, urea-formaldehyde-starch reactant, and the like, gelatin hardened with a known hardener, hardened gelatin coacervated and hardened into fine capsule hollow granules, and the like. Examples of inorganic compounds include silicon dioxide, titanium dioxide, magnesium dioxide, aluminum oxide, barium sulfate, calcium carbonate, silver chloride desensitized by known methods,
Similarly, silver bromide, glass, diatomaceous earth and the like can be preferably used. The above matting agents can be used by mixing different types of substances as necessary. The size and shape of the matting agent are not particularly limited, and those having an arbitrary particle size can be used. In the practice of the present invention, 0.1 μm to 30 μm
It is preferable to use one having a particle size of m. Further, the particle size distribution of the matting agent may be narrow or wide. On the other hand, since the matting agent greatly affects the haze of the photosensitive material and the surface gloss, the particle size, shape, and particle size distribution can be adjusted as needed during the preparation of the matting agent or by mixing a plurality of matting agents. preferable.

In the present invention, the matte degree of the back layer is preferably such that the Bekk smoothness is 250 seconds or less and 10 seconds or more, and more preferably 180 seconds or less and 50 seconds or more.

In the present invention, the matting agent is preferably contained in the outermost surface layer of the light-sensitive material, a layer functioning as the outermost surface layer, or a layer close to the outer surface. It is preferable to be contained.

In the present invention, suitable binders for the back layer are transparent or translucent, generally colorless, and natural polymer synthetic resins, polymers and copolymers, and other film-forming media such as: gelatin, gum arabic, poly (vinyl) Alcohol), hydroxyethylcellulose, cellulose acetate, cellulose acetate butyrate, poly (vinylpyrrolidone), 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 (urethanes), phenoxy resins, poly ( Vinylidene chloride), poly (epoxide) s,
Poly (carbonate) s, poly (vinyl acetate),
There are cellulose esters and poly (amides). The binder may be coated from water or an organic solvent or an emulsion.

In the present invention, the back layer may be an antihalation layer at the same time, and the maximum absorption in a desired wavelength range is preferably 0.3 or more and 2 or less, more preferably 0.5 or more and 2 or less. The absorption in the visible region after the treatment is preferably 0.001 or more and less than 0.5, more preferably 0.001 or more and less than 0.3,
Particularly preferably, the layer has an optical density of 0.001 or more and 0.1 or less. Examples of the antihalation dye used in the back layer are the same as those of the antihalation layer described above.

US Pat. Nos. 4,460,681 and 4,374,921
Backside resistive heating layer (backside resist
ive heating layer) can also be used in the photothermographic image system of the present invention.

A hardening agent may be used for each layer such as the photosensitive layer, the protective layer and the back layer of the present invention. Examples of hardeners include polyisocyanates described in U.S. Pat.No. 4,281,060 and JP-A-6-208193, epoxy compounds described in U.S. Pat.No.4,791,042, and JP-A-62-89048.
And vinylsulfone compounds described in Nos. 1 and 2 are used.

In the present invention, a surfactant may be used for the purpose of improving coating properties and charging. As the surfactant, any surfactant such as nonionic, anionic, cationic, and fluorine can be used as appropriate. Specifically,
No. 62-170950, U.S. Pat.No.5,380,644, fluorine polymer surfactants described in JP-A-60-244945, JP-A-63
No. 188135, U.S. Patent
No. 3,885,965, etc.
Examples thereof include polyalkylene oxides and anionic surfactants described in JP-A-6-301140.

Examples of the solvent used in the present invention include New Solvent Pocket Book (Ohm Co., 1994), but the present invention is not limited thereto. The solvent used in the present invention has a boiling point of 40 ° C or more and 180 ° C or more.
C. or lower is preferred.

Examples of the solvent of the present invention include hexane, cyclohexane, toluene, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, ethyl acetate, 1,1,1-trichloroethane, tetrahydrofuran,
Triethylamine, thiophene, trifluoroethanol, perfluoropentane, xylene, n-butanol,
Phenol, methyl isobutyl ketone, cyclohexanone, butyl acetate, diethyl carbonate, chlorobenzene, dibutyl ether, anisole, ethylene glycol diethyl ether, N, N-dimethylformamide, morpholine,
Examples include propane sultone, perfluorotributylamine, and water.

The heat-developable photographic emulsion of the present invention can be coated on various supports. Typical supports include polyester films, primed polyester films, poly (ethylene terephthalate) films, polyethylene naphthalate films, cellulose nitrate films, cellulose ester films, poly (vinyl acetal) films, polycarbonate films and related or resinous Including materials, as well as glass, paper, metal and the like. Flexible substrates, especially coated with partially acetylated or baryta and / or α-olefin polymers, especially polymers of C 2-10 α-olefins such as polyethylene, polypropylene, ethylene-butene copolymers A coated paper support is typically used. Such a support may be transparent or opaque, but is preferably transparent.

The light-sensitive material of the present invention comprises an antistatic or conductive layer, for example, a soluble salt (eg, chloride, nitrate, etc.), a vapor-deposited metal layer, US Pat. No. 2,861,056 and US Pat.
It may have a layer containing an ionic polymer as described in US Pat. No. 206,312 or an insoluble inorganic salt as described in US Pat. No. 3,428,451.

A method for obtaining a color image using the photothermographic material of the present invention is described in JP-A-7-13295, page 10, left column.
There is a method described from the 43rd line to the 11th left column, 40th line. Also, as a stabilizer for color dye images, British Patent No. 1,326,889,
U.S. Patents 3,432,300, 3,698,909, 3,574,627
Nos. 3,573,050, 3,764,337 and 4,042,39
No. 4 illustrates this.

The photothermographic emulsion of the present invention can be coated by various coating operations including dip coating, air knife coating, flow coating or extrusion coating using a hopper of the type described in US Pat. No. 2,681,294. If desired, two or more layers can be coated simultaneously by the methods described in U.S. Pat. No. 2,761,791 and British Patent 837,095.

Additional layers in the photothermographic material of the present invention, such as a dye-receiving layer for receiving a moving dye image, an opaque layer if reflective printing is desired, a protective topcoat layer and photothermographic techniques It may include a known primer layer and the like. The light-sensitive material of the present invention is preferably capable of forming an image with only one light-sensitive material, and it is preferable that a functional layer required for image formation such as an image receiving layer does not become another light-sensitive material.

The light-sensitive material of the present invention may be developed by any method, but is usually developed by raising the temperature of the light-sensitive material exposed imagewise. The preferred development temperature is 80 to
The temperature is 250 ° C, more preferably 100 to 140 ° C.
The development time is preferably from 1 to 180 seconds, more preferably from 10 to 90 seconds.

The light-sensitive material of the present invention may be exposed by any method, but a laser beam is preferred as an exposure light source.
As the laser beam according to the present invention, gas laser, YAG
Lasers, dye lasers, semiconductor lasers and the like are preferred. Further, a semiconductor laser and a second harmonic generation element can be used.

The light-sensitive material of the present invention has a low haze at the time of exposure and tends to cause interference fringes. Examples of this interference fringe prevention technology include a technology for obliquely entering a laser beam into a photosensitive material as disclosed in JP-A-5-113548 and a multi-mode laser disclosed in WO95 / 31754 and the like. There is known a method of utilizing these techniques, and it is preferable to use these techniques.

For exposing the light-sensitive material of the present invention, SPIE vo
l.169 Laser Printing 116-128 (1979), JP-A-4-510
No. 43, WO95 / 31754, etc., it is preferable to expose the laser beams so that they overlap each other so that the scanning lines are not visible.

[0232]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. Example 1 Preparation of Sample 101 (Preparation of Colored Emulsion) 100 mg of the coloring composition (D-1) and 1 g of methylandrostenediol as a decolorizing agent were uniformly mixed using 20 ml of ethyl acetate. Next, 2.5 ml of a 5% aqueous solution of sodium dodecylbenzenesulfonate and gelatin 1
5.44 g was added, and water was further added to make the total amount 60 g. This was emulsified and dispersed using a dissolver for 5 minutes to prepare a colored emulsion. The emulsion was applied on an undercoated cellulose triacetate film having a thickness of 127 μm so that the application amount of the coloring composition was 40 mg / m ² (Sample 101). In exactly the same manner, colored emulsions using the coloring compositions D-2 and D-3 were prepared, and samples 102 and 103 were prepared. Keep these samples at 140 ° C for 2
After heating for 0 seconds, the absorption residual ratio of the coloring composition was examined. Table 1 shows the results.

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[0233]

[Table 1]

In any of Samples 101 to 103 of the present invention, no recoloring was observed at room temperature. From the results, it was clarified that the coloring composition can be efficiently decolorized by heating.

Example 2 (Preparation of colored emulsion) 54 mg of colored composition (D-4), 120 mg of thermal radical generator (R-1), and defoamer (S-
1) 250 mg was dissolved by heating in 15.4 ml of ethyl acetate. Next, 5% of sodium dodecylbenzenesulfonate
2.5 ml of an aqueous solution and 15.44 g of gelatin were added, and water was further added to adjust the total amount to 60 g. This was emulsified and dispersed by a dissolver for 5 minutes to prepare a colored emulsion a. Coloring composition (D-4) is equimolar to coloring composition (D-5), (D-6)
, (D-7), except that the colored emulsions prepared in exactly the same manner as the colored emulsion a, except that
d. A colored emulsion prepared in exactly the same manner as the colored emulsion a except that the thermal radical generator (R-2) was not added was designated as a colored emulsion e.

A colored emulsion prepared in exactly the same manner as colored emulsion a except that 120 mg of photoradical generator (P-1) was added instead of adding thermal radical generator (R-1) was used. f
And

[0237]

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[0238]

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(Preparation of Sample 201) The colored emulsion a was applied onto a 127 μm-thick cellulose triacetate film support having an undercoat so that the coating amount of the colored composition was 40 mg / m ² . Colored dispersions b to f were applied on a support in the same manner as above to prepare Samples 202 to 206. The samples were thermally developed at 120 ° C. for 30 seconds, and the absorption residual ratio of the coloring composition was examined at room temperature. Further, the sample f was heated at 120 ° C. for 30 seconds, and then, at a film surface temperature of 80 ° C. or more, a 2000 W high-frequency lighting type ultra-high pressure mercury lamp (Printer P627GA manufactured by Dainippon Screen Co., Ltd.)
For 30 seconds. The sample was similarly examined for the absorption residual ratio of the coloring composition. Table 2 shows the results.

[0240]

[Table 2]

From this, it was revealed that the color composition can be efficiently decolorized without recoloring by using a thermal radical generator or a photoradical generator in combination with the decolorant.

Example 3 (Preparation of silver halide grains) In 700 ml of water, 22 g of phthalated gelatin and 30 mg of potassium bromide were dissolved, and the mixture was dissolved at a temperature of 35 ° C.
After adjusting the pH to 5.0, 159 ml of an aqueous solution containing 18.6 g of silver nitrate and 0.9 g of ammonium nitrate and an aqueous solution containing potassium bromide and potassium iodide in a molar ratio of 92: 8 by a control double jet method while maintaining the pAg at 7.7. It was added over a minute. Then, 55.4g of silver nitrate and ammonium nitrate
After adding 476 ml of an aqueous solution containing 2 g and an aqueous solution pAg7.7 containing 10 μmol / l of dipotassium hexachloridate and 1 mol / l of potassium bromide over 30 minutes by a control double jet method, 4- Add 1 g of hydroxy-6-methyl-1,3,3a, 7-tetrazaindene,
Further, the pH was further lowered to perform coagulation sedimentation and desalting treatment. Thereafter, 0.1 g of phenoxyethanol was added, pH 5.9, pAg8.2
Silver iodobromide grains (core iodine content 8 mol%, average 2
Mol%, average size 0.05 μm, projection area variation coefficient 8%, (1
00) cubic particles having an area ratio of 88%).

The silver halide grains thus obtained were heated to 60 ° C., and 85 μmol of sodium thiosulfate and 2,2
11 μmol of 3,4,5,6-pentafluorophenyldiphenylphosphine selenide, 15 μmol of a tellurium compound, 3.5 μmol of chloroauric acid, and 270 μmol of thiocyanic acid were added.
After ripening for 0 minutes, the mixture was rapidly cooled to 30 ° C. to obtain a silver halide emulsion.

(Preparation of Silver Organic Acid Emulsion) 7 g of stearic acid,
4 g of arachidic acid, 36 g of behenic acid and 850 ml of distilled water were added with vigorous stirring at 90 ° C. while adding 187 ml of a 1N-NaOH aqueous solution and reacted for 60 minutes. Next, 0.62 g of N-bromosuccinimide was added while stirring more vigorously, and 10 minutes later, silver halide grains prepared in advance were added so that the amount of silver halide became 6.2 mmol. Furthermore, add 125 ml of an aqueous solution of 21 g of silver nitrate to 100
The mixture was added over seconds, and the mixture was continuously stirred for 10 minutes, 0.62 g of N-bromosuccinimide was added, and the mixture was further left for 10 minutes. Thereafter, the solid content was separated by suction filtration, and the solid content was washed with water until the conductivity of the filtrate became 30 μS / cm. 150 g of a 0.6% by weight solution of polyvinyl acetate in butyl acetate was added to the solid content thus obtained, and the mixture was stirred. The stirring was stopped, the mixture was allowed to stand, the mixture was separated into an oil layer and an aqueous layer, and the aqueous layer was removed together with the contained salts to obtain an oil layer. Next, 80 g of a 2.5 wt% 2-butanone solution of polyvinyl butyral (Denka Butyral # 3000-K, manufactured by Denki Kagaku Kogyo KK) was added to this oil layer.
Was added and stirred. In addition, pyridinium perbromide bromide 0.
After adding 1 mmol and 0.15 mmol of calcium bromide dihydrate together with 0.7 g of methanol, 200 g of 2-butanone and 59 g of polyvinyl butyral (BUTVARTM B-76 manufactured by Monsanto Co.) were added, and the mixture was dispersed with a homogenizer. A silver salt emulsion (acicular grains having an average minor axis of 0.04 μm, an average major axis of 1 μm, and a variation coefficient of 30%) was obtained.

(Preparation of Emulsion Layer Coating Solution) Each chemical was added to the above-obtained organic acid silver emulsion in the following amount per mole of silver. Sodium phenylthiosulfonate 10 at 25 ° C
mg, 80 mg dye, 2-mercapto-5-methylbenzimidazole 2 g, 4-chlorobenzophenone-2-carboxylic acid 21.5
g, 2-butanone 580 g, and dimethylformamide 220 g were added with stirring. Then, 5 g of 5-tribromomethylsulfonyl-2-methylthiadiazole, 6 g of 2-tribromomethylsulfonylbenzothiazole, 5 g of 4,6-ditrichloromethyl-2-phenyltriazine, 2 g of a disulfide compound, 1,1-bis ( 155 g of 2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, Megafax F-
176P (fluorinated surfactant manufactured by Dainippon Ink and Chemicals, Inc.) 1.1 g, 2-butanone 590 g, methyl isobutyl ketone 10
g was added with stirring.

The structural formula of the compound used in the above is as follows.

[0247]

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(Emulsion surface protective layer coating solution) 75 g of CAB171-15S (cellulose acetate butyrate manufactured by Eastman Chemical Co., Ltd.), 4-g
5.7 g of methylphthalic acid, 1.5 of tetrachlorophthalic anhydride
g, phthalazine 12.5 g, tetrachlorophthalic acid 5.1 g, 0.3
g Megafax F-176P, Sildex H31 (Dokai Chemical Co., Ltd. spherical silica average size 3 μm) 2 g, sumidur N3500
(Polyisocyanate manufactured by Sumitomo Bayer Urethane Co., Ltd.)
-A solution prepared by dissolving in 3070 g of butanone and 30 g of ethyl acetate was prepared.

(Coating solution for back surface protective layer) Gelatin 10
g, polymethyl methacrylate (average particle size: 7 μm)
6 g, sodium dodecylbenzenesulfonate 0.4
g, X-22-2809 (a silicone compound manufactured by Shin-Etsu Silicone Co., Ltd.) in an amount of 0.9 g was dissolved in 500 g of water to obtain a back surface protective layer coating solution.

(Preparation of Photothermographic Material) The colored emulsions a, b, c, d and e obtained in Example 2 were placed on one side of a 175 μm-thick colored polyethylene terephthalate support having gelatin undercoat on both sides. It was applied so that the absorbance at the absorption maximum was 0.5. 2.3 g of silver was applied to the emulsion layer coating solution on the side opposite to the side on which the coloring composition of each sample was applied.
/ M ^2, and then a back surface protective layer coating solution was applied to the surface opposite to the emulsion layer at a flow rate such that the dry thickness was 0.9 μm. Further, a coating solution for an emulsion surface protective layer was applied on the emulsion surface so as to have a dry thickness of 2 μm, thereby preparing photothermographic materials 301 to 305. A photothermographic material 306 was prepared in exactly the same manner as the photothermographic material 301 except that the colored emulsion was not applied to the support. The smoothness of the coated photosensitive material thus obtained (J.TAPPI
The Beck's smoothness was measured using the Oken type smoothness measurement described in Paper Pulp Test Method No. 5). The range was 900 to 1100 seconds for the emulsion surface and 70 to 100 seconds for the back surface. Further, when the amount of the solvent remaining on the emulsion layer coated surface in the coated sample was measured by gas chromatography, it was 40 to 200 ppm based on the weight of the coated material.
Of 2-butanone and 40 to 120 ppm of butyl acetate were detected.

The following evaluations were made on the photothermographic materials 301 to 306 prepared as described above.

(Evaluation of Photographic Properties) After exposing the photosensitive material with a 635 nm semiconductor laser photometer, the photosensitive material was processed (developed) at 120 ° C. for 30 seconds, and the obtained image was evaluated with a densitometer. The results of the measurement were evaluated in terms of Dmin (fog) and sensitivity (the reciprocal of the ratio of the exposure amount giving a density higher than Dmin by 1.0). For the sensitivity, set the sensitivity of the photosensitive material 301 to 100.
And

(Evaluation of Sharpness) When a 635 nm semiconductor laser photometer exposed a square having a side of 1 cm, the density was 2.
Assuming that the exposure amount to be 5 is the exposure amount x and the exposure amount to be 0.5 is the exposure amount y, the exposure amount x and the exposure amount y are alternately set so that the long side of the rectangle having the short side of 100 μm and the long side of 1 cm is in contact. The maximum density and the minimum density of the exposed area were measured with a microdensitometer, and the difference between the maximum density and the minimum density divided by 2 was defined as the sharpness. Here, the greater the sharpness, the better the sharpness. Table 3 shows the results.

[0254]

[Table 3]

As is clear from Table 3, the photothermographic materials 301 to 304 of the present invention are superior in sharpness to the comparative photosensitive material 306, and have the same sensitivity as Dmin. At this time, in the comparative photosensitive material 305, since the residual color was extremely large, the image was difficult to see, and the practical problem was large.

The use of the heat-decolorable coloring layer according to the present invention is effective in improving the image quality of the dry-processed photosensitive material, and can provide a decolorizing antihalation layer having little influence on photographic properties. I understood.

Example 4 (Preparation of Photothermographic Material) (Preparation of Organic Acid Silver Emulsion A) 933 g of behenic acid was added to 12 liters of water, and while maintaining at 90 ° C., 48 g of sodium hydroxide was added.
A solution prepared by dissolving 63 g of sodium carbonate in 1.5 liters of water was added. After stirring for 30 minutes, the temperature was raised to 50 ° C., 1.1 L of a 1% aqueous solution of N-bromosuccinimide was added, and then 17% of silver nitrate was added.
2.3 liters of the aqueous solution was added slowly with stirring. Further, the liquid temperature was 35 ° C., and 1.5 liters of a 2% aqueous solution of potassium bromide was added over 2 minutes with stirring, followed by stirring for 30 minutes.
2.4 L of a 1% aqueous solution of N-bromosuccinimide was added. To this aqueous mixture was added 3300 g of a 1.2% by weight polyvinyl acetate butyl acetate solution with stirring, and the mixture was allowed to stand for 10 minutes to separate into two layers, the aqueous layer was removed, and the remaining gel was further washed with water.
Washed twice. The gel-like mixture of silver behenate and silver bromide thus obtained was dispersed in 1800 g of a 2.6% 2-butanone solution of polyvinyl butyral (Denka Butyral # 3000-K manufactured by Denki Kagaku Kogyo Co., Ltd.), and further dispersed in polyvinyl butyral ( 600 g of Butvar B-76 (manufactured by Nippon Monsanto Co., Ltd.) and 300 g of isopropyl alcohol were dispersed to obtain a silver salt of an organic acid emulsion (acicular particles having an average minor axis of 0.05 μm, an average major axis of 1.2 μm, and a coefficient of variation of 25%).

The compounds used in Example 4 are shown below.

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[0260]

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[0261]

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[0262]

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(Preparation of Emulsion Layer Coating Solution A) Each of the chemicals was added to the above-obtained organic acid silver emulsion in the following amount per mole of silver. At 25 ° C., 520 mg of sensitizing dye A, compound (4-1)
1.70 g, 4-chlorobenzophenone-2-carboxylic acid (4-2) 2
1.5g, calcium bromide dihydrate 0.90g and 2-butanone
580 g and dimethylformamide 220 g were added with stirring.
Left for 3 hours. Then, 1,1-bis (2-hydroxy-3,5-
Dimethylphenyl) -3,5,5-trimethylhexane (4-3)
160 g, 2.1 g of Exemplified Compound B-42 as a contrast agent, 17.7 g of phenyltribromomethylsulfone, coloring composition (4-4) 1.
11g, sumidur N3500 (Sumitomo Bayer Urethane Co., Ltd. polyisocyanate) 6.45g, Megafax F-176P (Dainippon Ink and Chemicals Co., Ltd. fluorine surfactant) 0.60g, 2
-590 g of butanone and 10 g of methyl isobutyl ketone were added with stirring.

(Preparation of Coating Solution A for Emulsion Surface Protective Layer) CAB171-15
65 g of S (cellulose acetate butyrate manufactured by Eastman Chemical Co., Ltd.), 5.6 g of phthalazine (4-5), 1.91 g of tetrachlorophthalic acid (4-6), 2.6 g of 4-methylphthalic acid (4-7), tetrachloro 0.67 g of phthalic anhydride (4-8), Megafax
A solution prepared by dissolving 0.36 g of F-176P and 2 g of Sildex H31 (average size of true spherical silica 3 μm manufactured by Dokai Chemical Co., Ltd.) in 1050 g of 2-butanone and 50 g of dimethylformamide was prepared.

(Preparation of Coating Solution for Back Side) Polyvinyl butyral (Denka Butyral # 4000-, manufactured by Denki Kagaku Kogyo KK)
2) 6g, Decolorant (S-2) 3.0g, Sildex H121 (Tokai Chemical Co., Ltd., spherical silica average size 12μm) 0.2g, Sildex H51 (Dokai Chemical Co., Ltd., spherical silica average size 5μm) 0.2
g, 0.1 g of Megafax F-176P and 64 g of 2-propanol were added with stirring to dissolve and mix. In addition, 23
A mixed solution of 0 mg of the coloring composition (D-8) and 525 mg of the thermal radical generator (R-2) in 10 g of methanol and 20 g of acetone, and 0.8 g of 3-isocyanatomethyl-3,5,5-trimethylhexyl isocyanate A solution prepared by dissolving g in 6 g of ethyl acetate was added to prepare a coating solution (1).

A coating solution prepared in exactly the same manner as the coating solution (1) except that an equimolar amount of the coloring composition (D-9) to (D-11) was added instead of the coloring composition (D-8). Are coating liquids (2) to (4). In addition, thermal radical generator (R-2)
Instead of the above, the coating liquids (11) to (14) were prepared in exactly the same manner as the coating liquids (1) to (4) except that an equimolar amount of the thermal radical generator (R-1) was added.

A coating solution prepared in exactly the same manner as the coating solution (1) except that the photoradical generator (R-2) was not included was used except that the coating solution (21) and the coloring composition (D-2) were not included. Is a coating liquid prepared in exactly the same manner as the coating liquid (1).

The back surface coating solutions (1) to (4), (11) to (14), and (21) were coated on a polyethylene terephthalate film having a moisture-proof undercoat containing vinylidene chloride on both sides to an optical density of 0.7 at 780 nm. The coating solution (22) was applied in the same amount as the coating solution (1). The samples are referred to as samples 401 to 404 and 41, respectively.
1 to 414, 421 and 422.

The emulsion layer coating solution was coated on the support prepared as described above so that the silver concentration was 1.6 g / m ^2, and the emulsion surface protective layer coating solution was dried on the emulsion surface to a dry thickness of 2.3 μm. It applied so that it might become.

(Evaluation of photographic performance) After exposure through a step wedge through an interference filter having a peak at 780 nm, xenon flash light with a light emission time of 10 ^-4 sec was applied to the sample.
After processing (developing) at 20 ° C. for 20 seconds, the obtained image was evaluated using a densitometer. The result of the measurement was evaluated based on the gradation γ (inclination of a straight line connecting points 0.3 and 3.0 of the characteristic density curve). (Evaluation of sharpness of halftone dots) Using a laser beam of 780 nm, a 50% flat screen of the above sample was output to the coated light-sensitive material using a laser beam of 780 nm, and developed under the above-mentioned processing conditions. I checked the halftone dots with a loupe. Evaluation result is 5 (good)
The test was performed using the 1 (bad) 5-point method. Practically, three or more points are required. (Evaluation of Remaining Color of Lowest Density Part) Three samples of the lowest density part of the sample from which the image was obtained were superimposed and evaluated visually. Those which were practically acceptable were evaluated as "OK", and the others were evaluated as "impossible". Table 4 shows the results.

[0271]

[Table 4]

(Results) In the sample in which the coloring composition of the present invention was applied to the back layer, the residual color was small, and it was found that the material was a photothermographic material having excellent image quality.

[0273]

The recording material of the present invention is extremely stable during storage before processing, but has a high image sharpness having a colored layer which can be easily erased without being discolored by heating when necessary. The effect is obtained.

[Procedure amendment]

[Submission date] November 1, 1999 (1999.11.
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 4

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

[0017]

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[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction contents]

[0042]

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Claims (5)

[Claims] 1. A colored composition comprising at least an electron-donating color-forming organic compound and an acidic developer on a support, and aromatic hydrocarbons, alcohols, ethers, ketones, esters, and amides. Recording material comprising a decolorizable coloring layer containing a decoloring agent selected from the group consisting of carboxylic acids, carboxylic acids, bases and base precursors. 2. An electron-donating color-forming organic compound, a color developer,
At least one of the decoloring agents has a polymerizable functional group, characterized in that the decolorizable coloring layer further contains a polymerization initiator,
The recording material according to claim 1. 3. A heat-developable photosensitive material having a heat-developable photosensitive layer containing at least a reducible silver salt, a photocatalytic substance and a reducing agent, a coloring composition comprising at least an electron-donating color-forming organic compound and an acidic developer. And at least one decolorizable coloring layer containing a decolorant selected from aromatic hydrocarbons, alcohols, ethers, ketones, esters, amides, carboxylic acids, bases and base precursors. A photothermographic material comprising: 4. The method according to claim 2, wherein the reducible silver salt is an organic silver salt, the photocatalytic substance is a photosensitive silver halide,
4. The photothermographic material according to claim 3, further comprising a super-high contrast agent. 5. An electron-donating color-forming organic compound, a color developer,
At least one of the decoloring agents has a polymerizable functional group, characterized in that the decolorizable coloring layer further contains a polymerization initiator,
The photothermographic material according to claim 3.