JP2002090938A - Heat developable material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable material having high sensitivity and low fog and to provide a heat developable material having superior light and heat resistances after heat development. SOLUTION: In the heat developable material with a photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a reducing agent and a binder and a layer adjacent to the photosensitive layer on the base, a polyhalomethane compound having an anthraquinone nucleus is contained in at least one of the layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-developable material for forming an image by heat development, and more particularly to a heat-developable material capable of obtaining high sensitivity and low fog and having excellent light resistance and heat resistance.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for photothermographic materials which do not generate waste liquid due to wet processing in the fields of medical treatment and printing in view of environmental protection and workability. Photothermographic materials capable of forming images have been commercialized and rapidly spread. Since these photothermographic materials are usually developed at a temperature of 80 ° C. or higher,
It is called a heat-developable material because it is distinguished from a conventional photosensitive material which is liquid-developed in the range of 5 ° C to 45 ° C. Conventionally, this type of heat-developable material has a high sensitivity to silver halide grains spectrally sensitized with a dye, a photosensitive layer containing an organic silver salt and a reducing agent, and further absorbs light irradiated toward the photosensitive layer. An antihalation layer (AI layer) for preventing irregular reflection at the interface of the support, an intermediate layer, an adhesive layer, etc., and a backing layer (BC layer) provided on the opposite side of the support; A protective layer is provided on the photosensitive layer and the BC layer to prevent damage during handling. Generally, a heat-developable material is easy to process because an image is formed only by heat development after exposure, but it is important to improve the storability of the image after development because there is no fixing step. In order to improve the storage stability after development, it is preferable to develop the image at a high temperature so that an image appears. However, if the development is performed at an excessively high temperature, fog is likely to occur and the sensitivity is reduced.

Therefore, development is generally performed at a temperature around 120 ° C. ± 10 ° C. The use of a mercapto compound to reduce the fog generated here is disclosed in
-301037, JP-A-5-341432, JP-A-5-509182, JP-A-2000-196
No. 81 discloses this. However, when any of the mercapto compounds is used alone, the effect of suppressing fog is small, and it is difficult to obtain high sensitivity, and there is a limit in improving light resistance and heat resistance. A phthalazine compound is often used as a heat developing material because it has little fog, accelerates development, obtains high sensitivity, and has good color tone. The use of these phthalazine compounds is described in JP-A-50-67132, JP-A-61-183642, JP-A-9-114036 and JP-A-9-25836.
No. 6, No. 10-508599, No. 10-33
Nos. 9928, 10-339930, and 10
No. 339931, No. 11-049756,
JP-A-11-052511, JP-A-11-180961, JP-A-11-218877, and JP-A-11-2239
No. 00, JP-A-2000-10234, 20
Nos. 00-10232 and 2000-35630
No. 6,009,036. It is described that the use of phthalazines improves fog, sensitivity, color tone, and the like. These phthalazines have low fog and can obtain high sensitivity, but have insufficient light resistance and heat resistance, and are not satisfactory.

[0004] In particular, a medical thermal developing material placed on a shakasten at the time of image reading is required not to increase fog or decrease the density of a high density portion due to light irradiation by a lamp of the shakasten. You. In order to improve the light resistance, techniques using many polyhalomethane compounds have been developed. Polyhalomethane compounds are used in heat-developable photosensitive materials because they release halogen radicals of oxidizable chlorine and bromine atoms by light or thermal excitation to bleach fog nuclei of silver halide and reduce fog. I have. For a technique using these polyhalomethane compounds, see, for example, US Pat. No. 3,874,946.
No. 4,452,885, No. 4,
Nos. 546,075, 4,756,999 and 5,340,712, Japanese Patent Publication No. 54-1979.
165, JP-A-50-137126, JP-A-7-2781, JP-A-9-265150 and JP-B-2-32614 (JP-A-59-90).
842) and the like. In addition, when a polyhalomethane compound is used, if the release of halogen radicals is excessive, the sensitivity is reduced or the concentration is reduced.
In order to suppress the reactivity, a method of introducing a ballast group or an adsorptive group is used, but there is a drawback that the mobility within a layer or between layers is suppressed and the original performance cannot be sufficiently exhibited. Further, the polyhalomethane compound has a problem in residual color if it has visible absorption, and therefore, has a spectral absorption of 400.
There is a restriction that the compound must be a compound of nm or less, and thus a good compound has not been found. Also,
There is a demand for storing the heat-developable material for a long time after development, and this also requires the provision of heat resistance to reduce the influence of photographic performance during high-temperature storage in summer. For imparting heat resistance, it may be effective to use a normal antifoggant such as a mercapto compound or a nitrogen-containing heterocyclic compound, but in a heat developing material without a fixing step, a more effective material may be used. There is a need for its use.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a heat-developable material having high sensitivity and low fog. It is a further object of the present invention to provide a heat-developable material having excellent light resistance and heat resistance after heat development.

[0006]

The object of the present invention is to provide: (1) photosensitive silver halide grains, an organic silver salt,
In a heat-developable material having a photosensitive layer containing a reducing agent and a binder and a layer adjacent to the photosensitive layer, at least one of the layers
A heat-developable material comprising a layer containing a polyhalomethane compound having an anthraquinone nucleus. (2) The heat-developable material as described in (1) above, wherein a polyacetal or a styrene-butadiene copolymer is used as a binder of the constituent layer. (3) The above (1) or (2), wherein the binder of the constituent layer is cured in the presence of a crosslinking agent having an isocyanate group, an alkoxysilane group, a vinylsone group or a carbodiimide group. Heat development material. (4) The heat-developable material as described in any one of (1) to (3) above, wherein the photosensitive layer or a layer adjacent to the photosensitive layer contains a mercapto compound. Achieved by

Hereinafter, the present invention will be described in detail. The heat-developable material of the present invention has at least one photosensitive layer and a layer adjacent to the photosensitive layer on a support, and has at least two layers on the support. The layers other than the photosensitive layer and the layer adjacent to the photosensitive layer include a backing layer (BC layer) and a protective layer provided on the opposite side of the photosensitive layer. The photosensitive layer of the heat-developable material contains photosensitive silver halide particles, an organic silver salt, a reducing agent and a binder,
The photosensitive silver halide grains may be sensitized with a spectral sensitizing dye, and the photosensitive layer may be composed of one layer containing photosensitive silver halide grains, an organic silver salt, and a reducing agent. It may be composed of a layer containing photosensitive silver halide grains and an adjacent layer containing an organic silver salt as a silver source and a layer containing a reducing agent for developing a silver salt to form a silver image. Further, the heat-developable material of the present invention contains "a polyhalomethane compound having an anthraquinone nucleus" (hereinafter may be abbreviated as AQH). Hereinafter, AQH, photosensitive silver halide particles, organic silver salts, reducing agents, binders, polyacetals or styrene-butadiene copolymers, isocyanate groups, alkoxysilane groups, vinylsphone groups or carbodiimides used in the heat developing material of the present invention will be described. The crosslinking agent having a group, the mercapto compound and the like will be described sequentially.

First, AQH will be described. AQH has an anthraquinone mother nucleus, and a polyhalomethane group or a group having a polyhalomethane is bonded to the mother nucleus. Anthraquinone nucleus is the 9th and 1st place of anthracene
It has a structure in which the 0-position is oxidized, and is also called 9,10-anthracenedione or 9,10-dioxoanthracene. AQH uses anthraquinone to have a functional group such as an amino group, a hydroxyl group, a carboxyl group, a vinyl group, an acid chloride group, or a halogen atom (chlorine, bromine, or iodine). Can be synthesized by introducing a substituent or the like, and replacing a hydrogen atom of a methyl group with a halogen atom. After the introduction of the halogen atom, oxidation can convert the thioether group to a sulfonyl group.

A method for synthesizing an anthraquinone nucleus into which an amino group, a hydroxyl group, a carboxyl group, a vinyl group, an acid chloride group, a halogen atom or the like is introduced is described, for example, in Japanese Patent Application Laid-Open No.
Nos. 6023, 6-097784 and 9-1
Nos. 76084 and 11-502865. The polyhalomethane group or the group having polyhalomethane may be bonded to the anthraquinone mother nucleus via a linking group, and the linking group may be 1-amino-4-
Phenylene group, sulfophenyl-4-amino group, carbonylphenyl-4-amino group, carboamidocyclohexyl-4-amino group, 4-sulfopyridyl-2-amino group, 1-carbamido-3-aminocyclopentadiene group, 3 , 5-tribromomethyl-4-aminophenyl group, 3,5-trichloromethylphenyl-4-amino group, triazine-1-amino group and the like. Preferred specific examples of AQH that can be used in the present invention are shown below.
H is not limited to these.

[0010]

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[0011]

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[0012]

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[0013]

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[0014]

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AQH is added by dissolving in an organic solvent such as alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone and acetone, aromatic solvents such as toluene and xylene, and non-aromatic solvents such as normal hexane and decane. Alternatively, it can be dispersed in water and added. Moreover, you may add directly to a powder or a tablet. AQH
Can be used in the range of 10 ^-5 mol to 10 ^-2 mol per mol of silver halide.

Next, the organic silver salt which can be used in the heat developing material of the present invention will be described. The organic silver salt used in the heat developing material of the present invention is a reducible silver source, and organic acids, heteroorganic acids, and silver salts of acid polymers containing a reducible silver ion source are used. Further, when the ligand is 4.0 to 4.0.
Organic or inorganic silver salt complexes having a total stability constant for silver ions of 10.0 are also useful. Examples of organic silver salts include Re
Search Disclosure Nos. 17029 and 29963, and include salts of organic acids (for example, salts of gallic acid, oxalic acid, behenic acid, stearic acid, palmitic acid, lauric acid and the like) and the like.

Next, the reducing agent that can be used in the heat developing material of the present invention will be described. Examples of preferred reducing agents used in the heat developing material of the present invention are described in US Pat.
No. 0,448, 3,773,512, 3,593,863, etc., Research,
ch Disclosure No. 17029 and 2996
No. 3 and the following are specifically mentioned. (K1) 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane (K2) bis (2-hydroxy-3-t-butyl-5-
Methylphenyl) methane (K3) 2,2-bis (4-hydroxy-3-methylphenyl) propane (K4) 4,4-ethylidene-bis (2-t-butyl-
6-methylphenol) (K5) 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane These compounds are added to a heat-developable material after being dispersed in water or dissolved in an organic solvent. can do. As organic solvents, alcohols such as methanol and ethanol,
Ketones such as acetone and methyl ethyl ketone, and aromatics such as toluene and xylene can be arbitrarily selected. The amount of the reducing agent used is 1 × 10 ^-2 to 10 per mol of silver.
Mol, preferably 1 × 10 ^{-2 to} 1.5 mol.

Next, photosensitive silver halide grains which can be used in the heat developing material of the present invention will be described. The photosensitive silver halide grains used in the heat developing material of the present invention are:
For example, it can be prepared by any method known in the field of photographic technology such as a single jet method and a double jet method, using any method such as an ammonia method, a neutral method, and an acidic method. The photosensitive silver halide grains can be mixed with other components of the present invention and introduced into the composition used in the present invention. In this case, in order to sufficiently effect the contact between the photosensitive silver halide and the organic silver salt, U.S. Pat.
No. 564, No. 3,706,565, No. 3,713,833, No. 3,748,14
No. 3, British Patent No. 1,362,970, means for using a polymer other than gelatin such as polyvinyl acetal, British Patent No. 1,354,18.
Means for enzymatically decomposing gelatin in a light-sensitive silver halide emulsion as described in US Pat.
As described in JP-A-76,539, various means such as a method of omitting the use of a protective polymer by preparing photosensitive silver halide grains in the presence of a surfactant can be applied.

The photosensitive silver halide preferably has a small grain size in order to suppress white turbidity after image formation and to obtain good image quality. The average particle size is 0.1 μm or less, preferably 0.01 to 0.1 μm, particularly preferably 0.02 to 0.08 μm. Further, the shape of the silver halide is not particularly limited, and there are cubic and octahedral so-called normal crystals and non-normal crystals such as spherical, rod-like and tabular grains, and these can be used. The composition of silver halide is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide, and silver iodide. The amount of the silver halide is 50% by mass or less, preferably 0.1 to 25%, based on the total amount of the silver halide and the organic silver salt.
%, More preferably between 0.1 and 15% by weight. Further, the silver halide may be obtained by converting a part of the organic silver salt to silver halide using a silver halide forming component, but in the step of converting a part of the organic silver salt to silver halide. Various conditions such as a reaction temperature, a reaction time, and a reaction pressure can be appropriately set according to the purpose of production. Usually, the reaction temperature is -23 ° C to 74 ° C, and the reaction time is 0.1 second to 7 seconds.
The reaction pressure is preferably set to atmospheric pressure for 2 hours.

The photosensitive silver halide prepared by the above-mentioned various methods can be chemically sensitized with, for example, a sulfur-containing compound, a gold compound, a platinum compound, a palladium compound, a silver compound, a tin compound, a chromium compound or a combination thereof. can do. The method and procedure of this chemical sensitization are described in, for example, U.S. Pat. No. 4,036,650, British Patent No. 1,518,850, JP-A-51-22430, and JP-A-51-78319. No.
No. 51-81124. The silver halide used in the present invention can be sensitized with a spectral sensitizing dye if necessary. Examples of the sensitizing dye include JP-A Nos. 63-159841, 60-140335 and 63-135. JP-A-231437, 63-25965
No. 1, No. 63-304242, No. 63-15
No. 245, U.S. Pat. Nos. 4,639,414, 4,740,455, and 4,744.
The sensitizing dyes described in 1,966, 4,751,175, and 4,835,096 can be used. Further, useful sensitizing dyes used in the present invention include, for example, Research Di.
section Item 17643 IV-A (1
December 978, p. 23), and the document described or cited in Item 1831X (p. 437, August 1978). In particular, as the sensitizing dye, it is advantageous to select a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources, for example, JP-A-9-34078, JP-A-9-54409, and JP-A-9-54409. -806
The compounds described in No. 79 are preferably used.

Next, the binder that can be used in the heat developing material of the present invention will be described. As the polymer binder that can be used in the heat developing material of the present invention, polyvinyl butyral, polyacrylamide, polystyrene, polyvinyl acetate, polyurethane, polyacrylate, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer , Vinyl chloride-vinyl acetate copolymer, styrene-butadiene-acrylic copolymer, and the like. As these polymer binders, those having a low equilibrium water content of the dried coating film are preferable.
Examples thereof include organic solvent-based cellulose acetate, cellulose acetate butyrate, and polyacetal. Polyacetal refers to a polymer obtained by producing polyvinyl alcohol by saponifying polyvinyl acetate and reacting this polyvinyl alcohol with an aldehyde compound.A preferred polyacetal for the present invention is polybutyral acetalized with butyraldehyde. And polyacetals acetalized with acetaldehyde (polyacetals in a narrow sense) are preferred.
Acetalization is theoretically present up to 1% to 100%, but practically preferably 20% to 95%. If the degree of acetalization is low, the number of hydroxyl groups is increased, and the photographic performance is weak against humidity. If the degree of acetalization is high, the reaction temperature and time are severe, and the cost and productivity are reduced.

For aqueous coating, a water-dispersed copolymer of styrene and butadiene, a copolymer of styrene and an alkyl acrylate or an alkyl methacrylate, or a copolymer of an alkyl acrylate and an alkyl methacrylate is used. Copolymers can be used. The water-dispersed polymer is preferably a fine particle having an average particle diameter in the range of 1 nm to several μm and dispersed in an aqueous dispersion medium. The water-dispersed polymer is particularly preferably hydrophobic from the viewpoint of improving the water resistance. The degree of polymerization of the polymer can be freely selected from about 10 to about 10,000, but 100 to 6000 is preferable from the viewpoint of applicability and productivity in synthesis. As the binder that can be used in the heat developing material of the present invention, polyacetal and styrene-butadiene copolymer are preferable.

Next, the crosslinking agent that can be used in the heat developing material of the present invention will be described. The binder can maintain adhesion with the lower layer and the upper layer by forming a film alone, and can obtain a film strength that is hard to be damaged, but further increases the film adhesion and the film strength by using a cross-linking agent. be able to.
The crosslinking agent preferably used in the present invention is preferably a crosslinking agent having an alkoxysilane group, an isocyanate group, an epoxy group (glycidyl group), a vinylsulfonyl group or a carbodiimide group. Particularly preferred crosslinking agents are crosslinking agents having at least two isocyanate groups, carbodiimide crosslinking agents having at least two carbodiimide groups,
An alkoxysilane crosslinking agent having at least two alkoxy groups and a vinylsulfonyl crosslinking agent having at least two vinylsulfonyl groups.

The crosslinking agents preferably used in the present invention are shown below. (H1) hexamethylene diisocyanate (H2) trimer of hexamethylene diisocyanate (H3) tolylene diisocyanate (H4) phenylene isocyanate (H5) xylylene diisocyanate (H6) 1,3-bis ( (Isocyanatomethyl) cyclohexane (H7) tetramethylenexylylenediisocyanate (H8) m-isopropenyl-α, α-dimethylbenzylisocyanate (H9) phenylaminopropyltrimethoxysilane (H10) p-methylphenylpropyltrimethoxysilane ( H11) Dimethylaminopropyltrimethoxysilane (H12) Diethoxyaminopropyltriethoxysilane (H13) 1,3-bis (vinylsulfonamido) propane (H14) 1,2-bis (vinylphone) Amido) ethane (H15) 1,3-bis (vinylsulfonamide) -2
-Hydroxypropane (H16) bis (vinylsulfonamide) ether

[0025]

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Crosslinking agents include water, alcohols, ketones,
It can be dissolved in a non-polar organic solvent and added to the coating solution, or can be added as a solid. The amount of addition is preferably equivalent to the group to be crosslinked, but may be increased up to 10 times or reduced to 1/10 or less. If the amount is too small, the crosslinking reaction does not proceed. If the amount is too large, the unreacted crosslinking agent deteriorates photographic properties, which is not preferable.

Next, the mercapto compound that can be used in the heat developing material of the present invention will be described. Examples of the mercapto compound that can be used in the present invention include a compound in which a mercapto group is bonded to an aromatic ring or a hetero ring via a linking group or directly. Here, a benzene ring or a naphthalene ring is preferable as the aromatic ring, and a 5- or 6-membered hetero ring containing a nitrogen atom, an oxygen atom or a sulfur atom is preferable as the hetero ring. Preferred heterocycles include imidazole ring, triazole ring, benzimidazole ring, benzotriazole ring, pyridine ring, pyrimidine ring, pyrazine ring, purine ring, tetrazaindene ring, tetrazole ring, thiophene ring, furan ring, triazine ring and the like. Can be mentioned.
The group linking the mercapto group to the aromatic ring or the hetero ring may be any divalent linking group, and the trunk length is preferably 1 to 30 atoms. As the atoms constituting the trunk of the linking group, carbon, sulfur, oxygen, nitrogen, silicon and the like are preferable. Examples of the linking group include a methylene group, an ethylene group, a propylene group, a butylene group, a butene group, a hexylene group, an amide group, a sulfonamide group, a phenylene group, a thioether group, and an oxyether group.
Further, a group obtained by combining these groups may be used.

Preferred mercapto compounds that can be used in the present invention are shown below, but the mercapto compounds that can be used in the present invention are not limited to these. (M1) 1-phenyl-5-mercaptotetrazole (M2) 2-mercaptobenzimidazole (M3) 5-mercaptobenzotriazole (M4) 2-mercaptomethylbenzimidazole (M5) 2-mercaptoethylbenzimidazole (M6) 1, 3,5-trimercapto-s-triazine (M7) 6-mercaptopurine (M8) 6-hydroxy-3-methyl-5-mercapto-1,3,3a, 7-tetrazaindene (M9) 2-mercaptopyridine (M10) 2-mercaptopyrimidine (M11) 2-mercaptofuran (M12) 2,5-dimercaptothiophene

Mercapto compounds include water, alcohols,
It can be dissolved in ketones and non-polar organic solvents and added to the coating solution, or can be added as a solid. The addition amount is preferably 10 ^-6 mol to 10 ^-2 mol per mol of silver halide. If the amount is less than this, it is difficult to obtain the intended effect, and if it is more than this, desensitization, coating failure and the like are caused, which is not preferable. The mercapto compound used in the present invention may be a commercially available product or may be produced by a known synthesis method.

In the heat-developable material of the present invention, similarly to the known light-sensitive material, the light irradiated to the light-sensitive layer passes without being absorbed and diffuses at the interface of the support, the intermediate layer, the adhesive layer, and the like. And a backing layer (BC layer) provided on the opposite side of the support. Further, a protective layer is provided on the photosensitive layer and the BC layer to prevent scratches during handling. These antihalation layers (AI layers) and backing layers (BC
A dye is used for the layer). The heat-developable material of the present invention may contain a dye for the purpose of preventing irradiation or for achieving various other purposes. As the dye used for the purpose of preventing irradiation and halation, a dye that absorbs image exposure is used. As these dyes, the thermal decolorizable dyes described in the above-mentioned US Pat. No. 5,384,237 are preferable. When a dye that is not heat-decolorable is used, the amount used is limited to a range that does not cause image damage. However, a heat-decolorable dye is preferable because a necessary and sufficient amount of dye can be used.

A matting agent can be used in the heat-developable material of the present invention as in the known light-sensitive material. The matting agent to be used may be either an organic substance or an inorganic substance. Examples of the inorganic matting agent include Swiss Patent No. 330,1.
Examples of the silica and organic matting agents described in the specification of No. 58 include polystyrene or polymethacrylate described in Swiss Patent No. 330,158, and US Pat. No. 3,079,257. Polyacrylonitrile, polycarbonate described in US Pat. No. 3,022,169, and the like can be used.

The shape of the matting agent may be either a fixed shape or an irregular shape, but is preferably a fixed shape matting agent, and a spherical matting agent is preferably used. The particle size of the matting agent is represented by a spherical diameter having the same volume as the volume of the matting agent. In the present invention, the particle diameter of the matting agent refers to the diameter converted into a sphere. The matting agent used in the present invention preferably has an average particle size of 0.5 to 10 μm, more preferably 1.0 to 8.0 μm. The matting agent particles preferably have a monodispersity of 50 or less, more preferably 40 or less, and particularly preferably 20 or less. The monodispersity of the particles here is represented by a number obtained by dividing the standard deviation of the particle size distribution by the average particle size and multiplying by 100. The matting agent can be contained by dispersing it in a coating solution in advance and applying it, or by spraying the matting agent after the application of the coating solution and before the drying is completed.

As the support for the heat-developable material of the present invention, supports used in known photosensitive materials can be used. For example, paper, synthetic paper, nonwoven fabric, metal foil, polyethylene terephthalate, polyethylene A plastic film such as naphthalate or polycarbonate can be used, and a composite sheet in which these are combined can be arbitrarily used. The heat-developable material of the present invention is disclosed in JP-A-9-304869 and JP-A-9-31140.
No. 3, JP-A-2000-10230 can be used for laser exposure. The exposed heat developing material can be developed using an apparatus described in, for example, JP-A Nos. 11-65067, 11-72897, and 11-84619.

[0034]

EXAMPLES The present invention will be described below in more detail with reference to examples.
However, the present invention is not limited by these examples.
Not. Example 1 <Preparation of Subbed Support> Polyethylene having a thickness of 175 μm
12 W / m on both sides of the terephthalate support^Two・ Minutes
Subjected to a Rona discharge treatment, and coated on one side with the following undercoating coating solution a-1
And dried so that the dry film thickness becomes 0.6 μm.
An undercoat layer A-1 is provided, and the following undercoat is applied on the opposite surface.
Apply the solution b-1 so that the dry film thickness becomes 0.6 μm, and
After drying, an undercoat layer B-1 was provided. << Undercoating coating liquid a-1 >> butyl acrylate (30 mass
%), T-butyl acrylate (20% by mass), styrene
(25% by mass), 2-hydroxyethyl acrylate
(25 mass%) copolymer latex liquid (solid content 30
%) Diluted 15-fold. << Undercoat coating solution b-1 >> butyl acrylate (40 mass
%), Styrene (20% by mass), glycidyl acrylate
(40 mass%) copolymer latex liquid (solid content 30
%) Diluted 15-fold. Subsequently, the undercoat layer A-1 and
12 W / m on the upper surface of the undercoat layer B-1^Two・ Minute corona release
And an undercoat layer A-1 was formed on the undercoat layer A-1.
A coating liquid for obtaining a layer having a-2 is coated and dried to form a subbing layer A
-2 provided on the undercoat layer B-1.
Antistatic by applying and drying a coating liquid to obtain a layer having b-2
An undercoating upper layer B-2 having a function was provided. << Underdraw upper layer composition a-2 >> 1: 2 copolymer of styrene and butadiene 0.4 g / m^Two Silica particles (average particle size 3 μm) 0.05 g / m^Two << Underdrawing upper layer composition b-2 >> 1: 2 copolymer of styrene and butadiene 0.4 g / m^Two Tin oxide fine particles (average particle diameter 16 nm) 0.023 g / m^Two <Preparation of silver halide grain emulsion A>
Dissolve 7.5 g of naart gelatin and 10 mg of potassium bromide
After unraveling and adjusting the temperature to 28 ° C and the pH to 3.0,
Molar ratio of 370 ml of aqueous solution containing 74 g to (98/2)
Aqueous solution containing potassium bromide and potassium iodide
With the controlled double jet method while maintaining 7.7
Added over 10 minutes. Synchronized with the addition of silver nitrate
1 × 10 sodium salt of sachroiridium ^-6Mol /
One mole of silver was added. Thereafter, 4-hydroxy-6-methyl
0.3 g of 1,3,3a, 7-tetrazaindene
And adjust the pH to 5 with NaOH to adjust the average particle size.
0.036 μm, coefficient of variation of projected diameter area 8%, (10
0) Cubic silver iodobromide grains having an area ratio of 87% were obtained. This milk
Gelatin flocculant was added to the solution, flocculated and sedimented and desalted.
Thereafter, water was added to make up to 160 ml. <Preparation of water-dispersed organic silver salt> Behen in 3980 ml of pure water
Acid 111.4 g, arachidic acid 83.8 g, stearin
54.9 g of the acid were dissolved at 80 ° C. Then stir at high speed
While 1.5 mol sodium hydroxide aqueous solution 540.2
After adding 6.9 ml of concentrated nitric acid,
Upon cooling, a sodium organic acid solution was obtained. The above organic acids
While maintaining the temperature of the thorium solution at 55 ° C.,
Silver halide emulsion A (containing 0.038 mol of silver) and pure water 4
20 ml was added and stirred for 5 minutes. Next, one mole of nitric acid
760.6 ml of the silver solution was added over 2 minutes, followed by 2 more minutes.
The mixture was stirred for 0 minutes, and water-soluble salts were removed by filtration. That
Then, deionized water until the conductivity of the filtrate becomes 2 μS / cm.
Washing with water and filtration, and finally centrifugal dehydration and drying.
Was. <Coating of photosensitive layer and BC layer>
Each layer having the following composition is coated on the photosensitive layer side and BC side on the carrier.
Samples 101 to 122 were formed using a cloth. What
Drying is 45 ° C for 1 minute on both the photosensitive layer side and the BC side.
Went between. << BC layer side coating >> The following composition and amount on back side
A BC layer and a BC protective layer having
A BC layer and a BC protective layer were formed in this order. (BC layer) Binder: PVB-1 1.8 g / m^Two

[0035]

Embedded image Dye: C1 1.2 × 10 ⁻⁵ mol / m ²

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(BC Protective Layer) Cellulose Acetate Butyrate 1.1 g / m ² Matting Agent (PMMA: Average Particle Diameter 5 μm) 0.12 g / m ² << Application on Photosensitive Layer >> (Application of AI Layer) And an AI layer having a coating amount. Binder: described in Table 1 0.4 g / m ² Dye: C1 (same type as BC layer) AQH: described in Table 1 1.0 × 10 ^-4 molar equivalent / m ² (coating of photosensitive layer) Prepare a coating solution for
The photosensitive layer was formed by coating and drying on the AI layer. The amount of each component is shown below. In preparing the coating solution, the prepared solution of the organic silver salt was mixed with a polymer binder in an amount of 1.36 g / m ² in terms of silver. Binder: described in Table 1 2.6 g / m ² AQH: described in Table 1 3.2 × 10 ⁻⁴ equivalent / m ² Spectral sensitizing dye A1 2 × 10 ⁻⁵ mol / m ²

[0038]

Embedded image Antifoggants -1: pyridinium hydrobromide perbromide 0.3 mg / m ² antifoggant -2: isothiazolone 1.2 mg / m ² reducing agent (coating of the surface protective layer) K1 3.3 mmol / m ² surface protection A coating solution for forming a layer was prepared, and coated and dried on the photosensitive layer to form a surface protective layer. The amount of each component is shown below. Cellulose acetate butyrate 1.2 g / m ² Phthalazine 0.2 g / m ² 4-Methylphthalic acid 0.7 g / m ² Tetrachlorophthalic acid 0.2 g / m ² Tetrachlorophthalic anhydride 0.5 g / m ² Silica Matting agent (average particle size 5 μm) 0.5 g / m ² AQH: described in Table 1 1.0 × 10 ⁻⁴ equivalent / m ²

The binders used are shown below. PVB-1 Polyvinyl acetate having a polymerization degree of 500 was saponified by 98%, and 86% of the remaining hydroxyl groups were butyralized before use. Methyl ethyl ketone (MEK) was used as an organic solvent for the coating solution. SB-1 An aqueous dispersion obtained by emulsion-copolymerizing styrene and butadiene in a mass ratio of 1: 2 by a conventional method was used. The coating liquid was an aqueous coating liquid.

<Evaluation of photographic performance> The sample was 48% at 25 ° C.
After storing for 3 days in an atmosphere of relative humidity, 8
Exposure with a sensitometer using a 10 nm semiconductor laser,
After heating at 120 ° C. for 8 seconds after the exposure, the obtained sample was used as an immediate sample to determine the fog and sensitivity of the instant processing. The sensitivity was evaluated by the reciprocal of the ratio of the exposure amount giving a density 0.3 higher than the fog density, and expressed as a relative sensitivity using the sample 101 as a reference (100). Further, a part of the developed sample was subjected to 60 ° C. and 20% RH.
Fog after storage for 3 days in a high temperature atmosphere (Δ
Fog) was measured, and the heat resistance was evaluated. Immediately, the smaller the increase in fog compared to the sample, the better the heat resistance. In addition, a part of the developed sample was left on a 1000 lux shark casten for 10 hours, and a decrease in maximum density (ΔDmax) of the placed sample was measured to evaluate light fastness. Immediately as compared with the sample, the smaller the decrease in the maximum concentration, the better the light resistance.

[0041]

[Table 1] PTS (Comparative polyhalomethane compound) The compound 5 (6-phenyl-2,4-bis (trichloromethyl) -s-triazine) used in Example 7 of JP-B-2-32614 was used. Table 1 shows that when the AQH of the present invention is used, fog during heat development is small, photographic characteristics with high sensitivity are obtained, and light resistance and heat resistance are excellent. Example 2 Samples 201 to 222 were prepared in the same manner as in Example 1.
However, the AQH and mercapto compounds shown in Table 2 were added to the layers shown in Table 2. Addition amount AQH: The addition amounts of the AI layer, the photosensitive layer and the protective layer are the same as in Example 1. Mercapto compound: AI layer 1 × 10 ⁻⁴ mol / m ² photosensitive layer 2 × 10 ⁻⁴ mol / m ² protective layer 1 × 10 ^-4 mol / m ² The binders listed in Table 2 were used. In the same manner as in Example 1, the sensitivity and fog of immediate processing, heat resistance,
The light fastness was evaluated. The sensitivity was represented by a relative sensitivity where the sensitivity of the sample 201 was 100.

[0042]

[Table 2] Table 2 shows that when the AQH of the present invention and the mercapto compound are used in combination, the light resistance and the heat resistance are excellent.

Example 3 Samples 301 to 322 were prepared in the same manner as in Example 1.
However, as shown in Table 3, the crosslinking agent was added to the AI layer, the photosensitive layer and
Added to the protective layer. 2.8 × 10 in the photosensitive layer ^-FourMol /
m^Two0.8 × 10 for the protective layer^-FourMol / m^Two In the AI layer
Is 0.9 × 10^{- Four}Mol / m^TwoWas added. The same sample
The same crosslinking agent was used therein. Also, as a binder
The binders described in Table 3 were used. Immediately as in Example 1.
The processing sensitivity, fog, heat resistance, and light resistance were evaluated. Feeling
The degree is expressed as relative sensitivity with the sensitivity of sample 301 as 100.
Was.

[0044]

[Table 3] Table 3 shows that the use of the AQH of the present invention and a crosslinking agent improves light resistance and heat resistance.

[0045]

The heat-developable material of the present invention has high sensitivity, low fog, and excellent light resistance and heat resistance after heat development.

Claims (4)

[Claims] 1. A photothermographic material comprising, on a support, a photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a reducing agent and a binder, and a layer adjacent to the photosensitive layer. A heat-developable material comprising a layer containing a polyhalomethane compound having an anthraquinone nucleus. 2. The heat-developable material according to claim 1, wherein a polyacetal or a styrene-butadiene copolymer is used as a binder of the constituent layer. 3. The composition according to claim 1, wherein the binder of the constituent layer is cured in the presence of a cross-linking agent having an isocyanate group, an alkoxysilane group, a vinylsone group or a carbodiimide group. Thermal development material. 4. The heat-developable material according to claim 1, wherein the photosensitive layer or a layer adjacent to the photosensitive layer contains a mercapto compound.