JP2002311534A - Heat developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable photosensitive material having high transparency (low haze) and containing a dye which is rapidly decolored in heat development. SOLUTION: In the heat developable photosensitive material having at least one photosensitive layer on one face of a support and at least one gelatin- containing non-photosensitive layer on the other face, a dye or its salt bleachable by a base, a base precursor and a water-soluble or water-dispersible polymer having a 2-oxazoline group of formula (A) are contained on the face with the non-photosensitive layer. In the formula, R1 -R4 are each H, halogen, alkyl, aralkyl, phenyl or substituted phenyl.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photothermographic material, and more particularly to a photothermographic material suitable for medical diagnosis, industrial diagnosis, industrial photography, printing, and COM.

[0002]

2. Description of the Related Art In recent years, in the field of medical diagnostic films and photoengraving films, it has been strongly desired to reduce the amount of processing waste liquid from the viewpoint of environmental protection and space saving. Therefore, it can be efficiently exposed by a laser image setter or a laser imager, and can be formed into a clear black image having high resolution and sharpness. There is a need for techniques relating to photosensitive materials. According to these photothermographic materials, solution-based processing chemicals are not required,
It is possible to supply a simpler and environmentally friendly thermal development processing system to customers.

[0003] In the field of general image forming materials, there are similar requirements, but in particular, medical diagnostic images are required to be finely described, so that high-quality images excellent in sharpness and granularity are required. It is common to add a dye to a photographic light-sensitive material for the purpose of preventing a filter, halation or irradiation. These dyes generally function during image exposure, remove the dye during development processing, and generally prevent the coloring of the image due to absorption of the dye in the visible region after image formation.

In the conventional wet development processing, it is relatively easy to elute and remove the dye from the photosensitive material in the processing solution, but in the dry development processing such as thermal development, it is difficult. Therefore, a method of decolorizing a dye by the heat of heat development processing has already been proposed. For example, Japanese Patent Application Laid-Open No.
No. 52626 discloses a technique in which a compound that lowers the melting point is used in combination, the melting point of the base precursor is controlled, and the dye is decolorized by a base generated by the base precursor during thermal development. However, this technique increases the solid content in the membrane due to the design of the membrane and deteriorates the transparency of the film (has a high haze). There is the disadvantage that the rapid decolorization of the dye at the time is lost.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, an object of the present invention is to provide a photothermographic material having high transparency (small haze) and capable of rapidly decoloring a dye in heat development.

[0006]

Means for solving the above problems are as follows. That is, <1> the support has at least one photosensitive layer on one surface side, and has at least one non-photosensitive layer containing gelatin on the other surface side, and the non-photosensitive layer is present. On the surface side, heat containing a dye or salt thereof bleachable by a base, a base precursor, and a water-soluble or water-dispersible polymer having a 2-oxazoline group represented by the following general formula (A): It is a developed photosensitive material.

[0007]

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(In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, a phenyl group or a substituted phenyl group.) The photothermographic material according to <1>, wherein at least one of the non-photosensitive layers simultaneously contains a dye bleachable by a base or a salt thereof, and a base precursor. <3> The value obtained by dividing the swelling value of the film thickness when immersed in distilled water at 25 ° C. for 30 seconds by the film thickness in a dry state (swelling ratio) is:
The photothermographic material according to <1> or <2>, wherein the content is 30% or more and 130% or less. <4> Any one of the above items <1> to <3>, wherein the value obtained by dividing the coating amount of the base precursor by the coating amount of gelatin of the non-photosensitive layer containing the base precursor is from 20% by mass to 70% by mass. Or a photothermographic material according to (1).

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The photothermographic material of the present invention has at least one photosensitive layer on one side of the support and at least one non-photosensitive layer containing gelatin on the opposite side.
In the present invention, the value obtained by dividing the swelling value of the film thickness when immersed in distilled water at 25 ° C. for 30 seconds by the film thickness in a dry state (dry film thickness) is 30% or more and 130% or less. Preferred from the viewpoint of the water resistance of the photosensitive material, and more than 50% to 120%
It is more preferred that: At this time, the object to be measured is the photosensitive material before the heat development processing is performed. As a method of measuring the swelling value of the film thickness, the photothermographic material is immersed in distilled water at 25 ° C. for 30 seconds, frozen in liquid nitrogen, and cross-sectioned with a microtome so as to be perpendicular to the material surface. After cutting, it is freeze-dried at −90 ° C. and observed with a scanning electron microscope to measure the swollen film thickness Tw. on the other hand,
The cross section of the dried film thickness Td is also measured by a scanning electron microscope. The difference between Tw and Td thus obtained was divided by Td and multiplied by 100, and the resulting value was defined as the swelling ratio (unit%).

In the present invention, the value obtained by dividing the coating amount of the base precursor by the coating amount of gelatin in the non-photosensitive layer containing the base precursor is from 20% by mass to 70% by mass. It is preferable in that the haze of the material is low, and it is more preferable that the haze is 30% by mass or more and 60% by mass or less.

Hereinafter, in the present invention, the material contained on the side where the non-photosensitive layer is located will be described in detail. The water-soluble polymer having a 2-oxazoline group used in the present invention is a water-soluble polymer having a pendant 2-oxazoline group represented by the following general formula (A).

[0012]

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In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, a phenyl group or a substituted phenyl group, preferably a hydrogen atom And lower alkyl groups. Specific examples include the following combinations, but are not limited thereto.

[0014]

(Equation 1)

As a water-soluble polymer, JP-A-5-2952
No. 75 polymer (B). In particular,
As monomers having a 2-oxazoline group, 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and, if necessary, at least one other monomer in an aqueous medium by a conventionally known polymerization method. It can be synthesized by performing solution polymerization.

The amount of the monomer having a 2-oxazoline group is not particularly limited.
It is preferable that the monomer having a 2-oxazoline group accounts for at least 5% by mass, and more preferably at least 5% by mass and at most 100% by mass.

Other monomers include, for example, methyl acrylate, ethyl acrylate, n- or i-propyl acrylate, n-, i- or t-butyl acrylate, 2-hydroxyethyl acrylate, cyclohexyl acrylate, benzyl acrylate, ethylene glycol diacrylate. Acrylate, propylene glycol diacrylate, polyethylene glycol acrylate, α-chloro-methyl acrylate, α-chloro-ethyl acrylate, methyl methacrylate, ethyl methacrylate, n- or i-propyl methacrylate, n-, i-
Or t-butyl methacrylate, 2-hydroxyethyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, ethylene glycol dimethacrylate, propylene glycol dimethacrylate, acrylates such as polyethylene glycol methacrylate, methacrylates, or α-chloro-acrylates,
Vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, benzyl vinyl ether, cyclohexyl vinyl ether, vinyl acetate, vinyl propionate,
Vinyl esters such as vinyl benzoate, vinyl ketones such as ethyl vinyl ketone and cyclohexyl vinyl ketone, styrenes such as styrene, methyl styrene, chlorostyrene and divinyl benzene, acrylamide, methacrylamide, dimethylacrylamide, diethylacrylamide, n- or i-dipropylacrylamide, n
Examples thereof include acrylamides such as-, i- or t-dibutylacrylamide, and chloroolefins such as vinyl chloride and vinylidene chloride.

However, in order to impart water solubility to the polymer, it is necessary that at least 50% of the constituent monomers are hydrophilic monomers. As the hydrophilic monomer, the above-mentioned monomer having a 2-oxazoline group, and as other monomers, 2-hydroxyethyl acrylate, methoxy polyethylene glycol acrylate, 2-aminoethyl acrylate and salts thereof, acrylamide, N-methylolacrylamide, N- (2 -Hydroxyethyl) -acrylamide, acrylonitrile, 2-hydroxyethyl methacrylate, methoxypolyethylene glycol methacrylate, aminoethyl methacrylate and its salts, methacrylamide, N-methylol methacrylamide, N
-(2-hydroxyethyl) -methacrylamide, methacrylonitrile, sodium styrenesulfonate and the like.

As specific examples (numerical values are molar ratios), W-1: 2-isopropenyl-2-oxazoline (10
0) W-2: 2-vinyl-2-oxazoline / ethyl acrylate (70/30) W-3: 2-isopropenyl-2-oxazoline / 2-
Hydroxyethyl methacrylate / n-butyl methacrylate (60/20/20) W-4: 2-vinyl-5-methyl-2-oxazoline /
Acrylamide (80/20) and the like can be mentioned, but it is not limited to these. Further, commercially available water-soluble polymers can also be used. For example, Epocross WS-500, WS-300
(Each is Nippon Shokubai Co., Ltd.).

The water-dispersible polymer having a 2-oxazoline group in the present invention is represented by the general formula (A):
A water-dispersible polymer having an oxazoline group, specifically, a polymer (B) described in JP-A-2-99537.

Specifically, for example, a monomer having a 2-oxazoline group as described above and, if necessary, at least one other monomer as described above are formed by a conventionally known emulsion polymerization method or a core / shell structure. It can be synthesized by performing an emulsion polymerization method or the like.

The amount of the monomer having a 2-oxazoline group is not particularly limited.
It is preferable that the monomer having a 2-oxazoline group accounts for at least 5% by mass, and more preferably at least 5% by mass and at most 100% by mass.

The synthesis method is described, for example, in W. R. Sorens
on, T .; W. The compound can be synthesized by the method described in “Experimental Method for Polymer Synthesis”, pages 144 and 152 (Tokyo Kagaku Dojin), co-authored by Cambell (translated by Toshio Hoshino and Naoya Yoda). Emulsion polymerization for forming a core / shell structure can be synthesized by a method described in JP-A-8-286301.

As specific examples (numerical values are molar ratios), P-1: 2-isopropenyl-2-oxazoline / styrene / ethyl acrylate (30/40/30), P-2: 2-vinyl-2-oxazoline / Methyl methacrylate / cyclohexyl methacrylate (40/40
/ 20), P-3: 2-isopropenyl-4-methyl-2-oxazoline / n-butyl acrylate / styrene (30/3
5/35), P-4: 2-isopropenyl-2-oxazoline / n-
Butyl acrylate / styrene / divinylbenzene (3
0/30/30/10), and the like, but are not limited thereto. In addition, commercially available water-dispersible polymers can also be used, and Epocross K-1010E, K-1020E,
K-1030E, K-2010E, K-2020E, K
-2030E (Nippon Shokubai Co., Ltd.).

The amount (coating amount) of the water-soluble or water-dispersible polymer having a 2-oxazoline group represented by the general formula (A) can be appropriately selected according to the purpose. 0.01 to 10.0 mmol / m ² is preferable from the viewpoint that residual color is small and water resistance is good,
0.1-5.0 mmol / m < ² > is more preferable.

In the present invention, it is preferable to use a substance which lowers the melting point by 3 ° C. (deg) or more when mixed with a base precursor (hereinafter referred to as “melting point depressant”).
The melting point depressant is preferably one in which the melting point of the mixture with the base precursor is 3 ° C. or more lower than the melting point of the base precursor alone, more preferably 3 to 20 ° C. lower,
Those lowering by 5 ° C. are more preferable. If two kinds of powders of the base precursor and the melting point depressant are mixed in a mortar and the sample is subjected to differential scanning calorimetry (DSC) or the like, a change in the melting point can be observed. Two or more melting point depressants may be used simultaneously.

The melting point depressant may be a substance which lowers the melting point by 3 ° C. (deg.) Or more by one kind of compound. In the case where the melting point is lowered by 3 ° C. or more only by using two or more kinds of compounds. May be.

As for the method of addition, it is preferable to add as a co-dispersion of a mixture with a base precursor, and it is particularly preferable to add as a solid fine particle dispersion. In this case, the average particle diameter of the fine particles is preferably from 0.03 to 0.3 μm.

In the present invention, preferred melting point depressants will be described in detail. Preferred melting point depressants include compounds represented by the following formulas (I) to (III).

[0030]

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In the general formula (I), R ₁₁ and R ₁₂ each independently represent an aliphatic group, an aromatic group or a heterocyclic group. However, when R ₁₂ is an aliphatic group, R ₁₁ represents an aromatic group or a heterocyclic group.

The compound represented by formula (I) will be described in detail. The “aliphatic group” means an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, a substituted alkynyl group, an aralkyl group or a substituted aralkyl group. In the present invention, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aralkyl group and a substituted aralkyl group are preferred, and an alkyl group, a substituted alkyl group, an aralkyl group and a substituted aralkyl group are more preferred. The chain aliphatic group may have a branch.

The number of carbon atoms of the alkyl group is preferably 1 to 30, more preferably 1 to 20, and even more preferably 1 to 15. The alkyl part of the substituted alkyl group is the same as the alkyl group.

The alkenyl group and the alkynyl group preferably have 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and even more preferably 2 to 15 carbon atoms. The alkenyl part of the substituted alkenyl group and the alkynyl part of the substituted alkynyl group are the same as the alkenyl group and the alkynyl group, respectively.

The "aromatic group" is a monocyclic or condensed-ring aryl group which may have a substituent. The aryl group preferably has 6 to 30 carbon atoms,
It is more preferably 20 and even more preferably 6 to 15. The aryl part of the substituted aryl group is the same as the aryl group. Examples include a benzene ring and a naphthalene ring.

"Heterocyclic group" means a 5- or 6-membered heterocyclic or substituted heterocyclic group. The heterocyclic moiety of the substituted heterocyclic group is the same as the heterocyclic group.

Examples of the heterocyclic group include pyrrole, indole, furan, thiophene, imidazole, pyrazole, indolizine, quinoline, carbazole, phenothiazine, indoline, thiazole, pyridine, pyridazine, thiadiazine, pyran, thiopyran, and the like.
Oxadiazole, benzoquinoline, thiadiazole,
Pyrrolothiazole, pyrrolopyridazine, tetrazole,
Oxazole, coumarin, chroman and the like can be mentioned. Each of these may have a substituent.

The substituents that each of the above groups may have are not particularly limited as long as they are other than a carboxyl group and a salt of the carboxyl group. Examples of the substituent include a sulfonamide group having 1 to 20 carbon atoms (eg, methanesulfonamide, benzenesulfonamide, butanesulfonamide, n-octanesulfonamide), and a sulfamoyl group having 0 to 20 carbon atoms (eg, unsubstituted sulfamoyl) , Methylsulfamoyl, phenylsulfamoyl, butylsulfamoyl), a sulfonylcarbamoyl group having 2 to 20 carbon atoms (eg, methanesulfonylcarbamoyl, propanesulfonylcarbamoyl, benzenesulfonylcarbamoyl),
An acylsulfamoyl group having 1 to 20 carbon atoms (eg, acetylsulfamoyl, propionylsulfamoyl, benzoylsulfamoyl), a chain or cyclic alkyl group having 1 to 20 carbon atoms (eg, methyl, ethyl, cyclohexyl, 2-hydroxyethyl, 4-carboxybutyl,
2-methoxyethyl, benzyl, 4-carboxybenzyl, 2-diethylaminoethyl), an alkenyl group having 2 to 20 carbon atoms (eg, vinyl, allyl), 1 to 20 carbon atoms
(E.g., methoxy, ethoxy, butoxy), a halogen atom (e.g., F, Cl, Br), an amino group having 0 to 20 carbon atoms (e.g., an unsubstituted amino group, dimethylamino, diethylamino, carboxyethylamino), carbon atom An alkoxycarbonyl group having 2 to 20 carbon atoms (for example, methoxycarbonyl), an amide group having 1 to 20 carbon atoms (for example, acetamido or benzamide),
0 carbamoyl group (for example, unsubstituted carbamoyl, methylcarbamoyl, phenylcarbamoyl), carbon number 6
To 20 aryl groups (eg, phenyl, naphthyl, 4-
Carboxyphenyl, 4-methanesulfonamidophenyl, 3-benzoylaminophenyl), having 6 to 20 carbon atoms
Aryloxy group (e.g., phenoxy, 3-methylphenoxy, naphthoxy), an alkylthio group having 1 to 20 carbon atoms (e.g., methylthio, octylthio),
20 arylthio groups (e.g., phenylthio, naphthylthio) and an acyl group having 1 to 20 carbon atoms (e.g., acetyl,
Benzoyl, 4-chlorobenzoyl), having 1 to 20 carbon atoms
(E.g., methanesulfonyl, benzenesulfonyl), a ureido group having 1 to 20 carbon atoms (e.g., methylureide, phenylureido), and an alkoxycarbonylamino group having 2 to 20 carbon atoms (e.g., methoxycarbonylamino, hexyloxycarbonylamino) , Cyano group, hydroxyl group, nitro group, heterocyclic group (for example, 5-ethoxycarbonylbenzoxazole ring, pyridine ring, sulfolane ring, furan ring, pyrrole ring, pyrrolidine ring, morpholine ring, piperazine ring, pyrimidine ring) and the like. Can be.

R ₁₁ is preferably an aromatic group, more preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, Examples include an acyl group, a sulfonyl group, an alkoxycarbonyl group, an alkoxy group, a substituted or unsubstituted carbamoyl group, and a halogen atom. A substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a sulfonyl group,
Alkoxy groups and halogen atoms are more preferred, and substituted or unsubstituted alkyl groups, sulfonyl groups and halogen atoms are most preferred.

As R ₁₂ , an aromatic group and a heterocyclic group are preferred. When R ₁₂ is an aromatic group, more preferred substituents for the substituted aryl group include a substituted or unsubstituted alkyl group, Substituted or unsubstituted aryl group, substituted or unsubstituted aralkyl group, acyl group, sulfonyl group, alkoxycarbonyl group, alkoxy group,
Examples include a substituted or unsubstituted carbamoyl group and a halogen atom. A substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a sulfonyl group, an alkoxy group and a halogen atom are more preferred, and a substituted or unsubstituted alkyl group, a sulfonyl group and a halogen atom are most preferred. When R ₁₁ or R ₁₂ is an aliphatic group, an aralkyl group is preferred.

Specific examples of the compound represented by formula (I) are shown below, but it should not be construed that the invention is limited thereto.

[0042]

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[0043]

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The compound represented by formula (II) which can be used in the present invention as a preferable melting point depressant will be described.

[0045]

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In the general formula (II), R ₂₁ and R ₂₂ each independently represent an aromatic group or a heterocyclic group, and X represents a linking group other than a sulfonyl group and a carboxy group.

The "aromatic group" is defined by the above-mentioned general formula (I)
Has the same meaning as "aromatic group". Also, “heterocyclic group”
It has the same meaning as the above-mentioned "heterocyclic group" in the general formula (I).

The substituents that each of the above groups may have have the same meaning as the “substituents that each of the groups may have” in the general formula (I). General formula (II) does not include general formula (I). As the linking group represented by X, a divalent linking group is preferably used. In the case of a trivalent or higher linking group, a hydrogen atom, an aliphatic group, or an aromatic group is independent of R ₂₁ and R _22. Alternatively, it may have a substituent selected from a heterocyclic group. Examples of specific linking groups include -C (= O)-,-
OC (= O) O-, -SO-, a substituted or unsubstituted methylene chain having 1 to 3 carbon atoms, -C (= O) -C (= O)-,
Examples include -C (OH) -C (= O)-, -S-, -O-, and the following.

[0049]

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R ₂₁ is preferably an aromatic group, more preferably a substituted aryl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, Examples include an acyl group, a sulfonyl group, an alkoxycarbonyl group, an alkoxy group, a substituted or unsubstituted carbamoyl group, and a halogen atom. A substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a sulfonyl group,
Alkoxy groups and halogen atoms are more preferred, and substituted or unsubstituted alkyl groups, sulfonyl groups and halogen atoms are most preferred.

As R ₂₂ , an aromatic group is preferable. When R ₂₂ is an aromatic group, more preferred substituents of the substituted aryl group include a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, and an acyl group. Group, sulfonyl group,
Examples include an alkoxycarbonyl group, an alkoxy group, a substituted or unsubstituted carbamoyl group, and a halogen atom.
A substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a sulfonyl group, an alkoxy group and a halogen atom are more preferred, and a substituted or unsubstituted alkyl group, a sulfonyl group and a halogen atom are most preferred. When R ₂₁ and R ₂₂ are an aliphatic group, an aralkyl group is preferred. Further, the substituents of R ₂₁ and R ₂₂ may combine with each other to form a ring together with X.

Specific examples of the compound represented by formula (II) are shown below, but it should not be construed that the invention is limited thereto.

[0053]

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[0054]

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The compound represented by formula (III) which can be used in the present invention as a preferable melting point depressant will be described.

[0056]

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In the general formula (III), R ₃₁ and R ₃₂ each independently represent an aromatic group or a heterocyclic group. However, the compound represented by the general formula (III) does not have a carboxyl group or a salt of a carboxyl group as a substituent.

The "aromatic group" is defined by the above-mentioned general formula (I)
Has the same meaning as "aromatic group". Also, “heterocyclic group”
It has the same meaning as the above-mentioned "heterocyclic group" in the general formula (I).

The substituents that each group may have are the same as those described above for the “substituents that each group may have” in formula (I).

R ₃₁ is preferably an aromatic group, more preferably a substituted aryl group as a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, Examples include an acyl group, a sulfonyl group, an alkoxycarbonyl group, an alkoxy group, a substituted or unsubstituted carbamoyl group, and a halogen atom. A substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a sulfonyl group,
Alkoxy groups and halogen atoms are more preferred, and substituted or unsubstituted alkyl groups, sulfonyl groups and halogen atoms are most preferred.

As R ₃₂ , an aromatic group is preferable. When R ₃₂ is an aromatic group, more preferred substituents of the substituted aryl group include a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, and an acyl group. Group, sulfonyl group,
Examples include an alkoxycarbonyl group, an alkoxy group, a substituted or unsubstituted carbamoyl group, and a halogen atom.
A substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a sulfonyl group, an alkoxy group and a halogen atom are more preferred, and a substituted or unsubstituted alkyl group, a sulfonyl group and a halogen atom are most preferred. Preferred specific examples of the compound represented by the general formula (III) include the compounds described on pages 6 to 8 of JP-A-11-352626.

[0062]

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The compounds represented by formulas (I) to (III) preferably have the same or higher melting point as the base precursor, and more preferably have a melting point of 70 to 400 ° C. Those having a melting point of 100 ° C to 300 ° C are more preferred. In the present invention, the total amount of the compounds represented by the general formulas (I) to (III) is preferably 20 parts by mass or more and 200 parts by mass or less based on 100 parts by mass of the base precursor. Also,
The compounds represented by the general formulas (I) to (III) remain in the background of the image after decolorization of the dye, and
Those which have an absorption maximum from 0 nm to 700 nm and do not give absorption which becomes a problem in the photothermographic material substantially do not occur. Further, it is preferable that the absorption at 400 nm or less does not give any substantial problematic absorption in the photothermographic material.

The base-bleachable dye or its salt (hereinafter sometimes referred to as “decolorizable dye”) used in the present invention is preferably a cyanine dye represented by the following general formula (IV) or a cyanine dye thereof. Salt.

[0065]

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In the general formula (IV), R¹Indicates an electron-withdrawing group
Then R^TwoRepresents a hydrogen atom, an aliphatic group or an aromatic group;^Three
And R^FourIs independently a hydrogen atom, a halogen atom,
Aliphatic group, aromatic group, -NR⁶R⁷, -OR⁶Or SR⁷To
Represents, R⁶And R⁷Are each independently a hydrogen atom or an aliphatic
A group or an aromatic group;^FiveRepresents an aliphatic group;¹, L
^TwoAnd L^ThreeAre, independently of each other, optionally substituted
A methine, wherein a substituent of methine is bonded to form an unsaturated aliphatic
It may form a ring or an unsaturated heterocyclic ring. Z¹And Z^TwoIs
Each independently form a 5- or 6-membered nitrogen-containing heterocycle
Is an atomic group in which an aromatic ring is fused to a nitrogen-containing heterocyclic ring.
The nitrogen-containing heterocycle and its fused ring may have a substituent.
It may be. m represents 0, 1, 2, or 3.

The compound represented by the general formula (IV) is described in detail.
This will be described in detail. In the general formula (IV), R ¹Represents an electron withdrawing group
And the degree is expressed by Hammett's substituent constant σm (eg,
For example, Chem. Rev .. , 91, 165 (1991).
) Is preferably 0.3 or more and 1.5 or less.
Preferably, -C (= O) R¹¹, -SOpR¹²The position represented by
And —C (＝ O) R¹¹Is preferred
No. R¹¹Represents a hydrogen atom, an aliphatic group, an aromatic group, -OR¹³,
-SR¹³Or NR¹³R¹⁴And R¹²Is an aliphatic group, aromatic
Group, -OR¹³Or NR¹³R¹⁴And p is 1 or 2
Represents Where R¹³, R¹⁴Is independently a hydrogen atom,
An aliphatic group or an aromatic group, or R¹³And R¹⁴
And combine to form a nitrogen-containing heterocyclic ring. R¹As further
Preferably -C (= O) R¹¹Where R¹¹But-
OR¹³Or NR¹³R¹⁴Is more preferable, and the photosensitive material
-NR in terms of storage stability¹³R¹⁴Is most preferred.

The "aliphatic group" means an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, a substituted alkynyl group, an aralkyl group or a substituted aralkyl group. In the present invention, an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aralkyl group and a substituted aralkyl group are preferred, and an alkyl group, a substituted alkyl group, an aralkyl group and a substituted aralkyl group are more preferred. A chain aliphatic group is preferred over a cyclic aliphatic group. The chain aliphatic group may have a branch. The alkyl group preferably has 1 to 30 carbon atoms, and has 1 to 20 carbon atoms.
Is more preferable, and it is still more preferable that it is 1-15. The alkyl part of the substituted alkyl group is the same as the alkyl group.

The alkenyl group and the alkynyl group preferably have 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, and even more preferably 2 to 15 carbon atoms. The alkenyl part of the substituted alkenyl group and the alkynyl part of the substituted alkynyl group are the same as the alkenyl group and the alkynyl group, respectively.

“Aromatic group” means an aryl group or a substituted aryl group. The number of carbon atoms in the aryl group is 6 to
It is preferably 30, more preferably 6 to 20, and still more preferably 6 to 15. The aryl part of the substituted aryl group is the same as the aryl group.

There are no particular restrictions on the substituents that each of the above groups may have. For example, a carboxyl group (which may be a salt), a sulfo group (which may be a salt), a sulfonamide group having 1 to 20 carbon atoms (for example, methanesulfonamide, benzenesulfonamide, butanesulfonamide, n- Octanesulfonamide), a sulfamoyl group having 0 to 20 carbon atoms (eg, unsubstituted sulfamoyl, methylsulfamoyl, phenylsulfamoyl, butylsulfamoyl), a sulfonylcarbamoyl group having 2 to 20 carbon atoms (eg, methanesulfonylcarbamoyl) , Propanesulfonylcarbamoyl, benzenesulfonylcarbamoyl), an acylsulfamoyl group having 1 to 20 carbon atoms (eg, acetylsulfamoyl, propionylsulfamoyl, benzoylsulfamoyl), a carbon number of 1 to 2
0 chain or cyclic alkyl group (for example, methyl, ethyl, cyclohexyl, trifluoromethyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl, 2-ethoxyethyl, benzyl, 4-carboxybenzyl, 2- Diethylaminoethyl), having 2 to 20 carbon atoms
Alkenyl group (e.g., vinyl, allyl) having 1 to 1 carbon atoms
20 alkoxy groups (eg, methoxy, ethoxy, butoxy), halogen atoms (eg, F, Cl, Br), amino groups having 0 to 20 carbon atoms (eg, unsubstituted amino groups, dimethylamino, diethylamino, carboxyethylamino), An alkoxycarbonyl group having 2 to 20 carbon atoms (e.g., methoxycarbonyl), an amide group having 1 to 20 carbon atoms (e.g., acetamido, benzamide, 4-chlorobenzamide), a carbamoyl group having 1 to 20 carbon atoms (e.g., unsubstituted carbamoyl, Methylcarbamoyl, phenylcarbamoyl, benzimidazol-2-onecarbamoyl), an aryl group having 6 to 20 carbon atoms (eg, phenyl, naphthyl, 4-carboxyphenyl, 4-methanesulfonamidophenyl, 3-benzoylaminophenyl), carbon number 6-20 Oxy group (eg, phenoxy, 3-methylphenoxy, naphthoxy), alkylthio group having 1 to 20 carbon atoms (eg, methylthio, octylthio), arylthio group having 6 to 20 carbon atoms (eg, phenylthio, naphthylthio), and 1 to 20 carbon atoms. Acyl group (eg, acetyl, benzoyl, 4-chlorobenzoyl), sulfonyl group having 1 to 20 carbon atoms (eg, methanesulfonyl, benzenesulfonyl), ureido group having 1 to 20 carbon atoms (eg, methylureide, phenylureide), carbon number 2 to 20 alkoxycarbonylamino groups (for example, methoxycarbonylamino, hexyloxycarbonylamino), a cyano group, a hydroxyl group, a nitro group, a heterocyclic group (for example, a 5-ethoxycarbonylbenzoxazole ring, a pyridine ring, a sulfolane ring, Orchid ring, pyrrole ring, pyrrolidine ring, morpholine ring, piperazine ring, pyrimidine ring, phthalimide ring, tetrachlorophthalimides ring, benzo isoquinolinedione ring) and the like.

In the general formula (IV), R ² is a hydrogen atom,
It is an aliphatic group or an aromatic group. The definitions of the aliphatic group and the aromatic group are as described above. R ² is preferably a hydrogen atom or an aliphatic group, more preferably a hydrogen atom or an alkyl group, further preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and more preferably a hydrogen atom. Is most preferred.

In the general formula (IV), R ³ and R ⁴ are each independently a hydrogen atom, a halogen atom, an aliphatic group, an aromatic group, —NR ⁶ R ⁷ , —OR ⁶ or SR ⁷ . R ⁶ and R ⁷ are each independently a hydrogen atom, an aliphatic group or an aromatic group. The definitions of the aliphatic group and the aromatic group are as described above. R ³ and R ⁴ are preferably a hydrogen atom or an aliphatic group, more preferably a hydrogen atom, an alkyl group, a substituted alkyl group, an aralkyl group or a substituted aralkyl group, and more preferably a hydrogen atom, an alkyl group or an aralkyl group. Is more preferable, and a hydrogen atom is most preferable.

In the general formula (IV), R ⁵ is an aliphatic group. The definition of the aliphatic group is as described above. R ⁵ is
It is preferably a substituted alkyl group. From the viewpoint of easy synthesis, R ⁵ is particularly preferably a substituted alkyl group having the same definition as —CHR ¹ R ² .

In the general formula (IV), L ¹ , L ² and L ³
Are each independently a methine which may be substituted. Examples of the substituent of methine include a halogen atom, an aliphatic group and an aromatic group. The definitions of the aliphatic group and the aromatic group are as described above. The substituents of methine may combine to form an unsaturated aliphatic ring or an unsaturated heterocyclic ring. Unsaturated aliphatic rings are preferred over unsaturated heterocycles. The ring formed is preferably a 6-membered ring or a 7-membered ring, more preferably a cycloheptene ring or a cyclohexene ring. It is particularly preferred that methine is unsubstituted or forms a cycloheptene ring or a cyclohexene ring.

In the general formula (IV), Z ¹ and Z ² are each independently an atomic group forming a 5- or 6-membered nitrogen-containing heterocyclic ring. Examples of the nitrogen-containing heterocyclic ring include an oxazole ring,
Examples include a thiazole ring, a selenazole ring, a pyrroline ring, an imidazole ring, and a pyridine ring. 5 than 6-membered ring
Member rings are preferred. An aromatic ring (benzene ring, naphthalene ring) may be condensed with the nitrogen-containing heterocyclic ring. The nitrogen-containing heterocycle and its condensed ring may have a substituent.
The substituents are as defined above. In the general formula (IV), m is 0, 1, 2, or 3.

The cyanine dye represented by the general formula (IV) is
It is preferable to use a salt after forming an anion. When the cyanine dye represented by the general formula (IV) has an anionic group such as carboxyl or sulfo as a substituent,
Dyes can form internal salts. Otherwise, the cyanine dye preferably forms a salt with an extramolecular anion. The anion is preferably monovalent or divalent, and more preferably monovalent. Examples of anions include halogen ions (Cl ⁻ , Br ⁻ , I ⁻ ),
p-toluenesulfonic acid ion, ethyl sulfate ion,
1,5-disulfonaphthalenedianion, PF ₆ ⁻ , BF
₄ ^- and ClO ₄ ^- are included. Preferred cyanine dyes are
It is represented by the following general formula (IVa).

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In the general formula (IVa), R ²¹ , R ²² , R
²³ , R ²⁴ , R ²⁵ , L ²¹ , L ²² , L ²³ and m ₁ are respectively R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁵ in the general formula (IVa).
It is synonymous with L ¹ , L ² , L ³ and m.

In the general formula (IVa), Y^{twenty one}And Y
^{twenty two}Are independently -CR²⁶R ²⁷, -NR²⁶−, −
O-, -S- or Se-. R²⁶And R²⁷Is it
Are each independently a hydrogen atom or an aliphatic group,
To form a ring. The aliphatic group is an alkyl group or
Particularly preferred is a substituted alkyl group.

In the general formula (IVa), the benzene ring Z ²¹
And Z ²² may be condensed with another benzene ring.
The benzene rings Z ²¹ and Z ²² and their condensed rings may have a substituent. The substituents are as defined above.

In the general formula (IVa), m ₁ is 0,
1, 2, or 3. The cyanine dye represented by the general formula (IVa) is preferably used after forming a salt with an anion. The formation of the salt is as described in the general formula (IV).

The following are specific examples of dyes or salts thereof that can be bleached with a base, but are not limited thereto.

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The above dyes and other cyanine dyes are disclosed in
The compound can be synthesized with reference to the methods described in JP-A-123454 and JP-A-7-333784.

Synthesis Example 1 Synthesis of Cyanine Dye (1) A mixture of 33.4 g of ethyl bromoacetate, 15.9 g of 2,3,3-trimethylindolenine and 30 ml of ethanol was heated under reflux for 5 hours. After the reaction, acetone 50m
l and 500 ml of ethyl acetate were added, and the precipitated quaternary salt was filtered off. The yield of the quaternary salt is 25.4 g, melting point 250 ° C
That was all.

16.3 g of a quaternary salt, 4.9 g of tetramethoxypropane, 75 g of N-methylpyrrolidone, 2.8 acetic acid
A mixed solution of 5 g and 19.0 g of acetic anhydride was heated at 50 ° C. for 3 hours. After completion of the reaction, 50 ml of water was added, and the precipitated crystals were separated by filtration and recrystallized with methanol / isopropanol / ethyl acetate. The yield is 13.1 g, the melting point is 250 ° C. or higher, λmax is 637.5 nm, and ε is 2.1.
It was 6 × 10 ⁵ (methanol).

The dye or salt thereof which can be bleached by a base in the present invention is a compound which can be decolorized by the action of a base under heating conditions. Such dyes include those which form a substantially colorless 5- or 7-membered ring compound by an intramolecular nucleophilic reaction. For example, the general formula (I
When a base is allowed to act on the dye of V) under heating conditions, CHR ¹ R
^A 5- or 7-membered ring compound is formed by ² and CR ³ or CR ⁴ , the conjugation is broken, and a substantially colorless compound is obtained.

The formed 5- or 7-membered ring compound is a substantially colorless and stable compound, which does not return to the original dye and does not cause a problem that the decolored substance is recolored.

Next, the base precursor will be described. There are various types of base precursors that can be used in the present invention. However, since the decolorization reaction is carried out under heating conditions, it is preferable to use a precursor of a type that generates (or releases) a base by heating. A typical example of a base precursor that generates a base by heating is a pyrolytic (decarboxylation) base precursor composed of a salt of a carboxylic acid and a base. When the decarboxylation type base precursor is heated, the carboxyl group of the carboxylic acid undergoes a decarboxylation reaction to release an organic base. As the carboxylic acid, sulfonylacetic acid or propiolic acid, which is easily decarboxylated, is used.
Sulfonyl acetic acid and propiolic acid are aromatic groups that promote decarboxylation (aryl groups and unsaturated heterocyclic groups)
As a substituent. The base precursor of sulfonyl acetate is disclosed in JP-A-59-1684.
Japanese Patent Application Laid-Open No. 41805/1979 discloses a propiolate base precursor in JP-A-59-180537.

The base side component of the decarboxylation type base precursor is preferably an organic base, more preferably amidine, guanidine or a derivative thereof. The organic base is preferably a diacid, triacid or tetraacid, more preferably a diacid, and most preferably an amidine derivative or a guanidine derivative.

The precursor of the diacid base, triacid base or tetraacid base of the amidine derivative is described in JP-B-7-595.
No. 45, there is a description. For the precursor of the diacid, triacid or tetraacid base of the guanidine derivative,
This is described in JP-B-8-10321.

The diacid base of the amidine derivative or guanidine derivative binds (A) two amidine moieties or guanidine moieties, (B) a substituent of amidine moieties or guanidine moieties, and (C) two amidine moieties or guanidine moieties. It consists of a divalent linking group. Examples of the substituent (B) include:
Includes alkyl groups (including cycloalkyl groups), alkenyl groups, alkynyl groups, aralkyl groups and heterocyclic residues. Two or more substituents may combine to form a nitrogen-containing heterocyclic ring. The linking group (C) is preferably an alkylene group or a phenylene group.

Examples of the diacid base precursor of the amidine derivative or the guanidine derivative are shown below.

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The use amount (mole) of the base precursor is preferably 1 to 100 times, more preferably 3 to 30 times the use amount (mole) of the decolorizing dye. The decolorizable dye can be used for various applications by utilizing the decolorization reaction as described above. For example, a solution of a decolorizable dye and a base precursor can be used as a thermal decolorizable ink. A solution obtained by applying a solution of a decoloring dye and a base precursor to a transparent support can also be used as a thermal decoloring type sheet (filter).

Further, the decolorizable dye and the base precursor can be applied to a thermal decolorable recording material. The heat-decolorable recording material has a recording layer on a support (preferably a transparent support). The decolorizable dye is dispersed in the recording layer in the form of a molecule or solid fine particles. When molecularly dispersed, a solution of the decoloring dye is added to the coating solution for the recording layer. In the case of dispersing in the form of solid fine particles, a dispersion of solid fine particles of the decolorizable dye is added to the coating solution for the recording layer. The base precursor is preferably dispersed in the recording layer in the form of solid fine particles. The recording layer preferably further contains a binder. As the binder, a hydrophilic polymer (eg, polyvinyl alcohol, gelatin, dextran, polyacrylamide) is preferably used.

In the present invention, a decolorizing dye and a base precursor are added to the non-photosensitive layer of the photothermographic material to make the non-photosensitive layer function as a filter layer or an antihalation layer. A photothermographic material generally has a non-photosensitive layer in addition to a photosensitive layer. The non-photosensitive layer is composed of (1) a protective layer provided on the photosensitive layer (on the side farther than the support) from the disposition thereof, and (2) a protective layer between a plurality of photosensitive layers or between the photosensitive layer and the protective layer. It can be classified into an intermediate layer provided therebetween, (3) an undercoat layer provided between the photosensitive layer and the support, and (4) a back layer provided on the opposite side of the photosensitive layer. The filter layer is (1)
Alternatively, it is provided on the photosensitive material as the layer (2). The antihalation layer is provided on the photosensitive material as the layer (3) or (4). In the present invention, the mode (4) is particularly preferable.

The decolorizing dye and the base precursor (and the melting point depressant) are preferably added to the same non-photosensitive layer. However, they may be separately added to two adjacent non-photosensitive layers. Further, a barrier layer may be provided between the two non-photosensitive layers. As used herein, "the layer contains a decolorizing dye and a base precursor (and a melting point depressant)"
The case where there are a plurality of “layers”, that is, the case where the plurality of layers are adjacent layers separately containing a decoloring dye and a base precursor is also included. In the present invention, an adjacent layer is also used when a barrier layer is interposed.

As a method of adding the decolorizable dye to the non-photosensitive layer, a method of adding a solution, an emulsion, a solid fine particle dispersion or a polymer impregnated substance to the coating solution for the non-photosensitive layer can be adopted. Further, a decoloring dye may be added to the non-photosensitive layer using a polymer mordant. These addition methods are the same as the method of adding a dye to an ordinary photothermographic material. Latex used for polymer impregnation is disclosed in US Pat.
No. 199363, West German Patent Publication Nos. 25141274 and 2541230, European Patent Publication No. 029104 and Japanese Patent Publication No. 53-41091.
Further, an emulsification method of adding a decolorable dye to a solution in which a polymer is dissolved is described in the specification of International Publication No. 88/00723.

The amount of the decolorizable dye to be added is determined depending on the use of the dye. Generally, the optical density (absorbance) measured at the target wavelength is used in an amount exceeding 0.1. The optical density is preferably from 0.2 to 2. The amount of the dye used to obtain such an optical density is generally about 0.001 to 1 g / m ² , in terms of a coating amount per 1 m ² of the light-sensitive material. Preferably is about 0.005~0.8g / m ^2, particularly preferably about 0.01~0.2g / m ^2.

When the dye is decolorized according to the present invention, the optical density can be reduced to 0.1 or less. Two or more decolorizable dyes may be used in combination in a heat-decolorable recording material or a photothermographic material. Similarly, two or more base precursors may be used in combination.

The photothermographic material will be further described below. The photothermographic material is preferably a mono-sheet type (a type capable of forming an image on the photothermographic material without using another sheet such as an image receiving material). The present invention
It is particularly effective in photothermographic materials for near infrared exposure.

The photothermographic material has a photosensitive layer containing a photosensitive silver halide (a catalytically active amount of a photocatalyst) and preferably a reducing agent, and a non-photosensitive layer. The photosensitive layer further contains a binder (generally a synthetic polymer), preferably an organic silver salt (a reducible silver source). Further, it is preferable to include a hydrazine compound (a super-high contrast agent) and a color tone adjuster (which controls the color tone of silver). A plurality of photosensitive layers may be provided.
For example, a high-sensitivity photosensitive layer and a low-sensitivity photosensitive layer can be provided on a photothermographic material for the purpose of adjusting the gradation. The order of arrangement of the high-sensitivity photosensitive layer and the low-sensitivity photosensitive layer may be such that the low-sensitivity photosensitive layer is disposed below (the support side) or the high-sensitivity photosensitive layer is disposed below.

The non-photosensitive layer may be provided as another functional layer such as a surface protective layer in addition to the dye-containing layer described above, that is, the filter layer and the antihalation layer.

As silver halide, any of silver bromide, silver iodide, silver chloride, silver chlorobromide, silver iodobromide and silver chloroiodobromide can be used.

The amount of silver halide added is from 0.03 to 0.1.
6 g / m ² , preferably 0.05 to 0.4 g
/ M ² , more preferably 0.1 to 0.4 g
/ M ² is most preferred.

The silver halide is generally prepared as a silver halide emulsion by reacting silver nitrate with a soluble halide salt. However, it may be prepared by reacting silver soap with halogen ions and converting the soap portion of silver soap into halogen. Further, halogen ions may be added during the formation of the silver soap.

Preferred reducing agents are phenidone, hydroquinones, catechol and hindered phenol. As for the reducing agent, US Pat. Nos. 3,770,448, 3,773,512, 3,593,863 and 44,606.
No. 81 and Research Disclosure Magazine 170
No. 29 and 29963.

Examples of the reducing agent include aminohydroxycycloalkenones (eg, 2-hydroxy-piperidino-
2-cyclohexenone), N-hydroxyurea derivative (eg, Np-methylphenyl-N-hydroxyurea), aldehyde or ketone hydrazone (eg, anthracenaldehyde phenylhydrazone), phosphoramidophenol, phosphor Amidoanilines, polyhydroxybenzenes (eg, hydroquinone, t-butyl-hydroquinone, isopropylhydroquinone, 2,5
-Dihydroxy-phenylmethylsulfone), sulfohydroxamic acids (eg, benzenesulfohydroxamic acid), sulfonamidoanilines (eg, 4- (N-methanesulfonamido) aniline), 2-tetrazolylthiohydroquinones (eg, 2 -Methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone), tetrahydroquinoxalines (eg, 1,2,3,4-tetrahydroquinoxaline), amidooxines, azines (eg, aryl hydryl aliphatic carboxylate) Combinations of zides) and ascorbic acid, combinations of polyhydroxybenzene and hydroxylamine, reductone, hydrazine, hydroxamic acids, combinations of azines and sulfonamidophenols, α-cyanophenylacetic acid derivatives, bis-β-naphthol And 1,3-dihydroxybenzene derivatives, 5-pyrazolones, sulfonamidophenols, 2-phenylindane-1,3-
Dione, chroman, 1,4-dihydropyridines (eg,
2,6-dimethoxy-3,5-dicarbethoxy-1,
4-dihydropyridine), bisphenols (eg, bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, bis (6-hydroxy-m-tri) mesitol, 2,2-bis (4-hydroxy -3-methylphenyl) propane, 4,4-ethylidene-bis (2-t-
Butyl-6-methyl) phenol), UV-sensitive ascorbic acid derivatives and 3-pyrazolidones.

An ester of an aminoreductone that functions as a precursor of the reducing agent (eg, piperidinohexose reductone monoacetate) may be used as the reducing agent. Particularly preferred reducing agents are hindered phenols.

The amount of the reducing agent to be added is 0.01 to 5.0 g / m
² , and more preferably 0.1 to 3.0 g / m ² .

The photosensitive layer and the non-photosensitive layer preferably contain a binder. Generally, a colorless transparent or translucent polymer is used as the binder. Although a natural or semi-synthetic polymer (eg, gelatin, gum arabic, hydroxyethyl cellulose, cellulose ester, casein, starch) can be used, a synthetic polymer is preferable to a natural or semi-synthetic polymer in consideration of heat resistance. However, cellulose ester (eg,
Acetate and cellulose acetate butyrate) are relatively heat-resistant even if they are semi-synthetic polymers, and are preferably used as a binder for photothermographic materials.

Examples of synthetic polymers include polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid, polymethyl methacrylate, polyvinyl chloride, polymethacrylic acid, styrene / maleic anhydride copolymer, styrene /
Includes acrylonitrile copolymer, styrene / butadiene copolymer, polyvinyl acetal (eg, polyvinyl formal, polyvinyl butyral), polyester, polyurethane, phenoxy resin, polyvinylidene chloride, polyepoxide, polycarbonate, polyvinyl acetate, and polyamide. Hydrophobic polymers are preferred over hydrophilic polymers. Thus, styrene / acrylonitrile copolymer, styrene / butadiene copolymer, polyvinyl acetal, polyester, polyurethane, rosin acetate butyrate, polyacrylic acid, polymethyl methacrylate, polyvinyl chloride and polyurethane are preferred, and styrene / butadiene copolymer and polyvinyl acetal are more preferred. .

The binder is used after being dissolved or emulsified in a solvent (water or organic solvent) of the coating solution for the photosensitive layer or the non-photosensitive layer. When emulsifying the binder in the coating solution, the emulsion of the binder may be mixed with the coating solution.

As the binder used in the photosensitive layer, it is preferable to coat a polymer latex with an aqueous coating solvent. The amount of the binder used in the photosensitive layer is preferably 0.2 to 30 g / m ² , more preferably 1 to 15 g / m ^2.
Range.

The amount of the binder used in the layer containing the decolorizable dye is preferably adjusted so that the amount of the decolorizable dye is 0.1 to 60% by weight of the binder. The decolorizable dye is preferably from 0.2 to 30% by weight of the binder, and most preferably from 0.5 to 10% by weight.

The photosensitive layer or the non-photosensitive layer preferably further contains an organic silver salt. The organic acid forming the silver salt is preferably a long-chain fatty acid. Fatty acid has 10 to 10 carbon atoms.
It is preferably 30 and more preferably 15 to 25. An organic silver salt complex may be used. The ligand of the complex has a total stability constant of 4.0 to 1 for silver ions.
It is preferable to have it in the range of 0.0. For organic silver salts, see Research Disclosure (Research)
h Disclosure) Magazine 17029 and 29
No. 963.

Examples of organic silver salts include silver salts of fatty acids (eg, gallic acid, oxalic acid, behenic acid, stearic acid, palmitic acid, lauric acid), carboxyalkylthioureas (eg, 1- (3-carboxypropyl) ) Thiourea, 1-
Silver salt of (3-carboxypropyl) -3,3-dimethylthiourea), silver complex of polymer reaction product of aldehyde (eg, formaldehyde, acetaldehyde, butyraldehyde) and hydroxy-substituted aromatic carboxylic acid, aromatic carboxylic acid Silver salts of (e.g., salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid), thioenes (e.g., 3- (2-carboxyethyl)-
Silver salts or silver complexes of 4-hydroxymethyl-4-thiazoline-2-thioene, 3-carboxymethyl-4-thiazoline-2-thioene), nitric acid (eg, imidazole,
Pyrazole, urazole, 1,2,4-thiazole, 1
H-tetrazole, 3-amino-5-benzylthio-
(1,2,4-triazole, benzotriazole), silver salts of saccharin, silver salts of 5-chlorosalicylaldoxime and silver salts of mercaptides. Silver behenate is most preferred. The organic silver salt is preferably used in 0.05 g / m ² or more 3 g / m ² or less as the amount of silver, and more preferably used in 0.3 g / m ² or more 2 g / m ² or less.

The photosensitive layer or the non-photosensitive layer preferably further contains a super-high contrast agent. When a photothermographic material is used in the field of photographic printing, it is important to reproduce a continuous tone image or a line image using halftone dots. By using a super-high contrast agent,
The reproducibility of halftone images and line images can be improved. Hydrazine compounds, quaternary ammonium compounds or acrylonitrile compounds (US Pat.
545515). Hydrazine compounds are particularly preferred ultrahigh contrast agents.

The hydrazine compound is hydrazine (H ₂ N
—NH ₂ ) and a compound in which at least one of the hydrogen atoms has been substituted. As the substituent, an aliphatic group, an aromatic group, or a heterocyclic group is directly bonded to a hydrazine nitrogen atom, or an aliphatic group, an aromatic group, or a heterocyclic group is bonded to a hydrazine nitrogen atom via a linking group. . Examples of linking groups include -CO-,
_{-CS -, - SO 2 -,} - POR- (R is an aliphatic group, an aromatic group or a heterocyclic group), - CNH- and combinations thereof.

The hydrazine compound is described in US Pat.
Nos. 464738, 5496695, 5551241
Nos. 1 and 5,536,622, JP-B-6-77
Nos. 138 and 6-93082, JP-A-6-23049
7, No. 6-289520, No. 6-313951,
No. 7-5610, No. 7-77783, No. 7-104
No. 426 is described in each publication.

The hydrazine compound can be dissolved in an appropriate organic solvent and added to the photosensitive layer coating solution. Examples of organic solvents include alcohols (eg, methanol, ethanol, propanol, fluorinated alcohols), ketones (eg, acetone, methyl ethyl ketone), dimethylformamide, dimethyl sulfoxide, and methyl cellosolve. Further, a solution in which a hydrazine compound is dissolved in an oily (auxiliary) solvent may be emulsified in a coating solution. Examples of oily (auxiliary) solvents include dibutyl phthalate, tricresyl phosphate, glyceryl triacetate, diethyl phthalate, ethyl acetate and cyclohexanone. Further, a solid dispersion of a hydrazine compound may be added to the coating solution. The hydrazine compound can be dispersed using a known disperser such as a ball mill, a colloid mill, a Menton-galling, a microfluidizer, and an ultrasonic disperser.

The amount of the super-high contrast agent added was 1 mol of silver halide.
1 × 10^-6~ 1 × 10 ^-2To be a mole
Preferably 1 × 10^-Five~ 5 × 10^-3Be a mole
More preferably 2 × 10^-Five~ 5 × 10^-3Be mole
Is most preferred.

In addition to the ultrahigh contrast agent, a high contrast accelerator may be used. Examples of the high contrast accelerator include amine compounds (described in US Pat. No. 5,545,505), hydroxamic acids (described in US Pat. No. 5,545,507), acrylonitriles (described in US Pat. No. 5,545,507), and hydrazine compounds (described in US Pat. No. 5,545,507). 5558983).

The photosensitive layer or the non-photosensitive layer preferably further contains a color tone adjuster. The color tone adjuster is described in Research Disclosure No. 17029.

Examples of color tone adjusting agents include imides (eg, phthalimide), cyclic imides (eg, succinimide), pyrazolin-5-ones (eg, 3-phenyl-2-pyrazolin-5-one, -Phenylurazole), quinazolinones (eg, quinazoline, 2,4-thiazolidinedione), naphthalimides (eg, N-hydroxy-1,
8-naphthalimide), a cobalt complex (eg, hexamine trifluoroacetate of cobalt), mercaptans (eg, 3-mercapto-1,2,4-triazole), N- (aminomethyl) aryldicarboximides (eg, N- (dimethylaminomethyl) phthalimide), blocked pyrazoles (eg, N, N′hexamethylene-1-carbamoyl-3,5-dimethylpyrazole), isothiuronium derivatives (eg, 1,8- ( A combination of 3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and a photobleach (eg, 2- (tribromomethylsulfonyl) benzothiazole), a merocyanine dye (eg, 3-
Ethyl-5-((3-ethyl-2-benzothiazolinylidene) -1-methylethylidene) -2-thio-2,4-oxazolidinedione (ox
azolidinedione)), phthalazinone compounds and metal salts thereof (eg, phthalazinone, 4- (1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, 2,3-dihydro-1,4- Phthalazinedione, 8-methylphthalazinone), a combination of a phthalazinone compound and a sulfinic acid derivative (eg, sodium benzenesulfinate), a combination of a phthalazinone compound and a sulfonic acid derivative (eg, sodium p-toluenesulfonate), Phthalazine and its derivatives (eg,
Phthalazine, 6-isopropylphthalazine, 6-methylphthalazine), a combination of phthalazines and phthalic acid, phthalazine or a phthalazine adduct and a dicarboxylic acid (preferably o-phenylene acid) or an anhydride thereof (eg,
Maleic anhydride, phthalic acid, 2,3-naphthalenedicarboxylic acid, phthalic anhydride, 4-methylphthalic acid, 4-
Nitrophthalic acid, tetrachlorophthalic anhydride), quinazolinediones, benzoxazine, naltoxazine derivatives, benzoxazine-2,4-diones (eg, 1,3-benzoxazine-2,4-dione), Pyrimidines, asymmetric-triazines (for example,
2,4-dihydroxypyrimidine) and tetraazapentalene derivatives (eg, 3,6-dimerocapto-1,4-diphenyl-1H, 4H-2,3a, 5,6a-tetraazapentalene). Phthalazines are particularly preferred.

The toning agent is preferably contained in the image forming layer surface in an amount of 0.1 to 50 mol% per mol of silver.
More preferably, the content is 0.5 to 20 mol%.

An antifoggant may be added to the photosensitive layer or the non-photosensitive layer (preferably the photosensitive layer). As the antifoggant, a non-mercury compound (US Pat. No. 3,8749) is more preferable than a mercury compound (described in US Pat. No. 3,589,903).
No. 46, No. 4546075, No. 44452885, No. 4756999, No. 5028523, British Patent Application Nos. 92221383.4 and 9300147.7.
Nos. 9311790.1 and JP-A-59-1790.1.
No. 57234, Japanese Patent Publication No. 55-12581,
No. 32015 and 63-292125).

Particularly preferred antifoggants are heterocyclic compounds having a halogen (F, Cl, Br, I) substituted methyl group.

Silver halide is generally used after spectral sensitization. Regarding spectral sensitizing dyes, see JP-A-60-1403.
No. 35, No. 63-159,841 and No. 63-23143
No. 7, 63-259,651 and 63-304242
Nos. 63-15245 and U.S. Pat.
Nos. 414, 474,455 and 474,966,
Nos. 4,751,175 and 4,835,096.

In the photosensitive layer of the present invention, various dyes and pigments (for example, CI Pigment) are used from the viewpoints of improving color tone, preventing interference fringes during laser exposure, and preventing irradiation.
Blue 60, C.I. I. Pigment Blue
64, C.I. I. Pigment Blue 15: 6)
Can be used. International publication WO about these
No. 98/36322, JP-A-10-268465, JP-A-11-338098 and the like.

In the photothermographic material of the present invention, an antihalation layer can be provided on the side farther from the light source than the photosensitive layer. Regarding the antihalation layer, JP-A-11-65021, paragraph numbers [0123] to [0123]
124], JP-A-11-223898 and 9-230
No. 531; No. 10-36695; No. 10-10478
No. 9, No. 11-231457, No. 11-352625
And No. 11-352626. The antihalation layer contains an antihalation dye having absorption at the exposure wavelength. When the exposure wavelength is in the infrared region, an infrared absorbing dye may be used, and in that case, a dye having no absorption in the visible region is preferable. When using a dye having absorption in the visible region to prevent halation, it is preferable that substantially no color of the dye remains after image formation, and a means for decoloring by the heat of heat development is used. It is particularly preferable to add a thermal decoloring dye and a base precursor to the non-photosensitive layer to function as an antihalation layer. These techniques are described in JP-A-11-231457.

In the present invention, a coloring agent having an absorption maximum at 300 to 450 nm can be added for the purpose of improving the silver tone and the temporal change of the image. Such coloring agents are described in JP-A-62-210458 and JP-A-63-10404.
No. 6, No. 63-103235, No. 63-208846
Nos. 63-306436 and 63-314535
No. JP-A-01-61745, Japanese Patent Application No. 11-2767.
No. 51, etc. Such a coloring agent is usually added in the range of 0.1 mg / m ^{2 to 1} g / m ² , and the layer to be added is preferably a back layer provided on the side opposite to the photosensitive layer.

The photothermographic material of the present invention has at least one light-sensitive layer containing a silver halide emulsion and at least one non-light-sensitive layer on one side of a support, and has a backing layer on the other side. It is preferably a so-called one-sided photosensitive material having a layer (non-photosensitive layer).

In the present invention, it is preferable to add a matting agent for improving transportability.
JP-A-11-65021, paragraph numbers [0126] to [0]
127]. Matting agent is 1m ² of photosensitive material
When indicated by the amount of application per unit, preferably 1 to 400 m
g / m ² , more preferably 5 to 300 mg / m ² .
The matting degree of the emulsion surface may be any value as long as stardust failure does not occur, but the Beck smoothness is preferably 30 seconds to 2000 seconds, and particularly preferably 40 seconds to 1500 seconds. Beck smoothness is measured according to Japanese Industrial Standards (JI
S) It can be easily obtained by P8119 “Smoothness test method of paper and paperboard with Beck tester” and TAPPI standard method T479.

In the present invention, the matting degree of the back layer is preferably such that the Beck smoothness is from 1200 seconds to 10 seconds, more preferably from 800 seconds to 20 seconds.
More preferably, it is 500 seconds to 40 seconds.

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.

The photothermographic material of the present invention preferably has a pH of 7.0 or less, more preferably 6.6 or less, before the heat development. The lower limit is not particularly limited, but is about 3. The most preferred pH range is between 4 and
6.2. The adjustment of the film surface pH is preferably performed using an organic acid such as a phthalic acid derivative, a nonvolatile acid such as sulfuric acid, or a volatile base such as ammonia from the viewpoint of reducing the film surface pH. In particular, ammonia is preferable in achieving a low film surface pH since ammonia is easily volatilized and can be removed before the application step and the heat development. It is also preferable to use ammonia in combination with a non-volatile base such as sodium hydroxide, potassium hydroxide, and lithium hydroxide. The method for measuring the film surface pH is described in Japanese Patent Application
-87297, paragraph [0123].

As the support used in the present invention, 130 to 1 is used in order to alleviate the internal strain remaining in the film at the time of biaxial stretching and to eliminate the heat shrinkage distortion generated during the heat development processing.
Polyester, especially polyethylene terephthalate, which has been subjected to a heat treatment in a temperature range of 85 ° C. is preferably used. Further, as the support used in the present invention, a transparent support is preferable. In the case of a photothermographic material for medical use, the transparent support may be colored with a blue dye (for example, Dye-1 described in Examples of JP-A-8-240877) or may be uncolored. Examples of the support include a water-soluble polyester described in JP-A-11-84574, a styrene-butadiene copolymer described in JP-A-10-186565, JP-A-2000-39684, and JP-A-2000-39684.
No. 1-106881, paragraph numbers [0063] to [008]
It is preferable to apply an undercoating technique such as a vinylidene chloride copolymer [0]. Further, regarding the antistatic layer or the undercoat, JP-A-56-143430 and JP-A-56-143.
No. 431, No. 58-62646, No. 56-12051
9, paragraph No. [004] of JP-A-11-84573.
0]-[0051], US Pat. No. 5,575,957.
, Paragraph number [007] of JP-A-11-223898.
8] to [0084] can be applied.

The photothermographic material may further contain an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber or a coating aid. Various additives are added to either the photosensitive layer or the non-photosensitive layer. These are described in WO 98/36322, European Patent Publication EP 803.
No. 764A1, JP-A-10-186567, and JP-A-10-186567.
No. 18568 can be referred to.

Techniques that can be used for the photothermographic material of the present invention include those described in European Patent Publication EP803676A1.
No., European Patent Publication No. EP 883022 A1, International Publication W
O98 / 36322, JP-A-56-62648, JP-A-58-62644, JP-A-9-43766, and 9-2.
81637, 9-297367, 9-30486
9, No. 9-31405, No. 9-329865,
No. 10-10669, No. 10-62899, No. 10
No.-69023, No. 10-186568, No. 10-9
No. 0823, No. 10-171063, No. 10-186
No. 565, No. 10-186567, No. 10-1865
No. 69-No. 10-186572, No. 10-19797
No. 4, 10-197982, 10-197983
Nos. 10-197985 to 10-197987
Nos., 10-207001, 10-207004
No., 10-221807, 10-282601
No., 10-288823, 10-288824
No. 10-307365, No. 10-312038
No. 10-339934, No. 11-7100, No. 11-15105, No. 11-24200, No. 11-
No. 24201, No. 11-30832, No. 11-845
No. 74, No. 11-65021, No. 11-109547
Nos. 11-125880 and 11-129629
Nos. 11-133536 to 11-133439
Nos. 11-133542 and 11-133543
Nos. 11-2223898 and 11-352627
No., 11-305377, 11-305378
No. 11-305384, No. 11-305380
No. 11-316435, No. 11-327076
No. 11-338096 and No. 11-338098
No. 11-338099 and No. 11-343420
No., Japanese Patent Application No. 2000-187298, 2000-10
No. 229, No. 2000-47345, No. 2000-2
No. 06624, No. 2000-98530, No. 2000
-98531, 2000-112059, 20
00-112060, 2000-112104,
Nos. 2000-11204 and 2000-17193
No. 6 is also mentioned.

The photothermographic material of the present invention may be developed by any method. Usually, the photothermographic material exposed imagewise is heated and developed. The preferred development temperature is 80 to 250 ° C, more preferably 10 to 250 ° C.
0-140 ° C. The development time is preferably 1 to 60 seconds, more preferably 5 to 30 seconds, and particularly preferably 10 to 20 seconds.

As a method of thermal development, a plate heater method is preferable. The heat development method using a plate heater method is preferably a method described in JP-A-11-133572, in which a heat-developable photosensitive material on which a latent image is formed is brought into contact with a heating means in a heat development section to obtain a visible image. A developing device, wherein the heating means comprises a plate heater, and a plurality of pressing rollers are provided to face each other along one surface of the plate heater, and the heating means is provided between the pressing roller and the plate heater. A thermal developing apparatus for performing thermal development by passing a developing photosensitive material. It is preferable to divide the plate heater into two to six stages and lower the temperature at the tip part by about 1 to 10 ° C. Such a method is also described in JP-A-54-30032, in which water and organic solvents contained in the photothermographic material can be excluded from the system. The change in the shape of the support of the photothermographic material due to the heating of the photothermographic material can also be suppressed.

As a heating method in the heat development processing, for example, the forms shown in FIGS.

The photothermographic material conveyed to the image exposing section is exposed to laser light or the like scanned by a light beam, and a latent image is formed on the photothermographic material. Transported to At this time, dust on the back surface and the front surface of the photothermographic material is removed by the dust removing roller.

The heat developing section 18 is a part for performing a heat development by heating the photothermographic material to convert a latent image into a visible image. As shown in FIG.
It is characterized by having a plate heater 120 and a plurality of pressing rollers 122 arranged opposite to the plate heater 120.

The plate heater 120 is a plate-like heating member in which a heating element such as a nichrome wire is laid and accommodated in a plane, and is maintained at the developing temperature of the photothermographic material. Further, it is preferable that a fluororesin is coated on a surface of the plate heater 120 for the purpose of reducing frictional resistance or imparting abrasion resistance, or a sheet made of a fluororesin is attached.

Further, the heat development photosensitive material evaporates volatile components by heating during the heat development, and accordingly, the heat development photosensitive material floats up from the plate heater 120, and the contact between the heat development photosensitive material and the plate heater 120 becomes uneven. May be. Therefore, it is preferable to form minute irregularities on the surface of the plate heater 120 in order to release the vapor.

In order to compensate for a temperature decrease due to heat radiation at both ends of the plate heater 120, it is preferable to provide a temperature gradient so that the temperatures at both ends are higher than those at other portions.

The holding roller 122 is a plate heater.
0, or at a predetermined pitch over the entire length of the plate heater 120 in the transport direction with an interval equal to or less than the thickness of the photothermographic material.
2 and the plate heater 120 form a photothermographic material conveying path. By arranging the photothermographic material conveying path at an interval equal to or less than the thickness of the photothermographic material, buckling of the photothermographic material can be prevented. A pair of supply rollers 126 for supplying the photothermographic material to the heat developing unit 18 in the direction indicated by an arrow and a pair of discharge rollers for discharging the photothermographic material in the direction indicated by an arrow after the heat development are provided at both ends of the photothermographic material conveying path. 12
8 are provided.

Further, it is preferable to dispose a heat retaining cover 125 for keeping the temperature on the opposite side of the pressing roller 122 from the plate heater 120.

When the photothermographic material is transported,
When the leading end of the photothermographic material strikes the pressing roller 122, the photothermographic material stops momentarily. At this time, if the pressing rollers 122 are separated at a constant pitch, the same portion of the photothermographic material stops for each pressing roller 122 and that portion is pressed by the plate heater 120 for a long time. As a result, in the photothermographic material, streak-like development unevenness extending in the width direction occurs. Therefore, it is preferable to make the pitch of each pressing roller 122 non-uniform.

Further, as shown in FIG.
A configuration is also possible in which a drive roller 130 having the envelope surface of the peripheral surface 22 as a peripheral surface is provided in contact with each press roller 122, and each press roller 122 is rotated by rotating the drive roller 130.

In the above description, the plate heater 120 also includes a plate member made of a heat conductor, and a structure in which a heat source is arranged on the side of the plate member opposite to the heating surface of the photothermographic material.

The photothermographic 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, a gas laser (Ar ⁺ , He—Ne), a YAG laser, a dye laser, a semiconductor laser, or the like is preferable. Further, a semiconductor laser and a second harmonic generation element can be used.
Preferably, it is a gas or semiconductor laser emitting red to infrared light.

As a medical laser imager having an exposure section and a heat development section, there is a Fuji Medical Dry Laser Imager FM-DPL.
Regarding FM-DP L, Fuji Medical
Review No. 8, pages 39 to 55, and it goes without saying that those techniques are applied as a laser imager for the photothermographic material of the present invention. In addition, Fuji Medical Systems proposed "A" as a network system conforming to the DICOM standard.
It can also be applied as a photothermographic material for a laser imager in "D network".

The photothermographic material of the present invention forms a black-and-white image by a silver image, and is used for medical diagnosis, photothermographic material for industrial photography, photothermographic material for printing, COM
It is preferably used as a photothermographic material for use.

[0179]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. (Example 1) [Preparation of PET support] Using terephthalic acid and ethylene glycol, an intrinsic viscosity IV = 0.66 (phenol / tetrachloroethane = 6/4 (mass ratio)) according to a conventional method. 2
PET (measured at 5 ° C.). This was pelletized, dried at 130 ° C. for 4 hours, melted at 300 ° C., extruded from a T-die, and quenched to prepare an unstretched film having a thickness of 175 μm after heat setting.

This was carried out by using rolls having different peripheral speeds.
The film was longitudinally stretched by a factor of 2, and then transversely stretched by a factor of 4.5. The temperatures at this time were 110 ° C. and 130 ° C., respectively. After that, it was heat-set at 240 ° C. for 20 seconds, and relaxed 4% in the horizontal direction at the same temperature. After slitting the chuck part of the tenter, knurling is performed on both ends,
Take up at 4 × 10 ⁴ Pa (4 kg / cm ² ), thickness 17
A 5 μm roll was obtained.

[Surface Corona Treatment] Using a solid state corona treatment machine 6KVA model manufactured by Pillar Co., both surfaces of the support were treated at room temperature at 20 m / min. From the current and voltage readings at this time, 0.375 kV was applied to the support.
-It turned out that the processing of A * minute / m < ² > was performed.
At this time, the processing frequency was 9.6 kHz, and the gap clearance between the electrode and the dielectric roll was 1.6 mm.

[Preparation of Undercoating Support] (1) Preparation of Undercoating Layer Coating Solution Formulation 1 (for the undercoating layer on the photosensitive layer side) 234 g of Pesresin A-515GB (30% by mass solution) manufactured by Takamatsu Yushi Co., Ltd. Polyethylene glycol monononyl phenyl ether 10% by mass solution (average ethylene oxide number = 8.5) 21.5 g ・ Soken Chemical Co., Ltd. MP-1000 0.91 g (polymer fine particles, average particle diameter 0.4 μm) ・ Distilled water 744 ml

Formulation 2 (for the first layer on the back surface side) 158 g of styrene-butadiene copolymer latex (solid content: 40% by mass, styrene / butadiene mass ratio = 68/32) 2,4-dichloro-6-hydroxy -S-Triazine sodium salt 8% by mass aqueous solution 20g ・ 1% by mass aqueous solution of sodium laurylbenzenesulfonate 10ml ・ Distilled water 854ml

Formulation 3 (for the second layer on the back side) 84 g of SnO ₂ / SbO (9/1 mass ratio, average particle size 0.038 μm, 17 mass% dispersion) ・ Gelatin (10 mass% aqueous solution) 2g ・ Shin-Etsu Chemical Co., Ltd. Metroose TC-5 (2% by mass aqueous solution) 8.6g ・ Soken Chemical Co., Ltd. MP-1000 0.01g ・ 1% by mass aqueous solution of sodium dodecylbenzenesulfonate 10ml ・ NaOH (1 Mass%) 6 ml ・ Proxel (manufactured by ICI) 1 ml ・ Distilled water 805 ml

(2) Preparation of Undercoating Support The above-mentioned corona discharge treatment was applied to both surfaces of the biaxially stretched polyethylene terephthalate support having a thickness of 175 μm, and then the undercoating coating solution formulation 1 was applied to one surface (photosensitive layer surface).
With a wire bar and wet coating amount of 6.6 ml / m
² (per side) and dried at 180 ° C. for 5 minutes. Then, the undercoating liquid formulation 2 was coated on the back surface (back surface) with a wire bar with a wet coating amount of 5.7 m.
1 / m ² and dried at 180 ° C. for 5 minutes. Further, the undercoating coating liquid formulation 3 was coated on the back surface (back surface) with a wire bar so that the wet coating amount was 7.7 ml / m ^2. It was coated and dried at 180 ° C. for 6 minutes to prepare an undercoated support.

[Preparation of Back Surface Coating Solution] (Preparation of Solid Precursor Dispersion of Base Precursor) 1.5 kg of the base precursor compound 11 and 225 g of a surfactant (trade name: Demol N, manufactured by Kao Corporation) 937.5 g of diphenylsulfone (Compound Example III-1), 15 g of butyl parahydroxybenzoate (trade name: Platings: manufactured by Ueno Pharmaceutical Co., Ltd.) and distilled water were added to make a total amount of 5.5.
0 kg, and mix the mixture with a horizontal sand mill (U
VM-2: manufactured by IMEX Co., Ltd.). In the dispersion method, the mixed solution was sent to UVM-2 filled with zirconia beads having an average diameter of 0.5 mm using a diaphragm pump, and dispersed at an internal pressure of 50 hPa or more until a desired average particle size was obtained. The dispersion was subjected to spectral absorption measurement to determine the ratio of the absorbance at 450 nm to the absorbance at 650 nm (D450 / D) of the spectral absorption of the dispersion.
D650) was 2.2 or more. The resulting dispersion was 20% by mass in the concentration of the base precursor.
Diluted with distilled water and filtered for dust removal (average pore diameter: 3 μm polypropylene filter)
For practical use.

(Preparation of Dye Solid Fine Particle Dispersion) As a dye capable of being bleached with a base in the present invention, 6.0 kg of cyanine dye compound 13 and surfactant (W-13T) 3.
0 kg, 0.6 kg of a surfactant (trade name: Demol SNB, manufactured by Kao Corporation) and 0.15 kg of an antifoaming agent (trade name: Surfynol 104E, manufactured by Nissin Chemical Co., Ltd.) are mixed with distilled water. Thus, the total liquid volume was adjusted to 60 kg. The mixed solution was dispersed in beads using a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.). The dispersion was subjected to spectral absorption measurement to determine the ratio of the absorbance at 650 nm to the absorbance at 750 nm (D650 / D75) in the spectral absorption of the dispersion.
0) was 5.0 or more. The obtained dispersion was diluted with distilled water so that the concentration of the cyanine dye became 6% by mass, and filtered to remove dust (average pore diameter: 1 μm) and put to practical use.

(Preparation of Antihalation Layer Coating Solution) 4
300 g of gelatin, 245 g of polyacrylamide, 22 g of 1 mol / l caustic while being kept in water at 0 ° C. while stirring,
24 g of monodispersed polymethyl methacrylate fine particles (average particle size: 8 μm, particle size standard deviation: 0.4), 0.8 g of benzoisothiazolinone, and the above-mentioned dye solid fine particle dispersion 448
g, solid fine particle dispersion liquid 900 of the above base precursor
g, 5.9 g of sodium polyethylene sulfonate, 2.1 g of blue dye compound 14, and 83 g of acrylic acid / ethyl acrylate copolymer (copolymerization mass ratio of 5/95), and the whole was adjusted to 8183 ml with water. An antihalation layer coating solution of Material 1 was prepared. Further, the addition amount of the solid precursor dispersion of the base precursor in the antihalation layer coating liquid was changed as shown in Table 1, and / or a water-soluble compound having a 2-oxazoline group represented by the general formula (A). Polymers were added as shown in Table 1 to prepare antihalation layer coating solutions for other photosensitive materials.

(Preparation of back surface protective layer coating solution)
While keeping the temperature at ℃ and stirring, 400 g of gelatin, 15 g of liquid paraffin emulsion as liquid paraffin, 0.35 g of benzoisothiazolinone, 1 mol / l of caustic 68
g, sodium t-octylphenoxyethoxyethanesulfonate, 5 g, fluorine-based surfactant (F-1: polyethylene glycol mono (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [ethylene oxide average polymerization degree] 15]) 0.4 g, fluorinated surfactant (F-2) 0.4 g, fluorinated surfactant (F-3) 0.4 g, sodium polystyrene sulfonate 2.7 g, acrylic acid / ethyl acrylate copolymer 60 g of the copolymer (copolymerization mass ratio of 5/95) and 10 g of N, N-ethylenebis (vinylsulfoneacetamide) were mixed, and the mixture was adjusted to 10 liters with water to obtain a back surface protective layer coating solution. In addition, N, N-ethylenebis (vinylsulfoneacetamide) of the coating solution for the back surface protective layer was applied to the photosensitive material 3
Only, the addition amount was changed to 20 g.

<< Preparation of Silver Halide Emulsion 1 >> Distilled Water 14
To 21 ml, 3.1 ml of a 1% by weight potassium bromide solution was added, and 3.5 ml of 0.5 mol / L sulfuric acid was further added.
While stirring the solution to which 31.7 g of phthalated gelatin was added in a stainless steel reaction bottle, the solution temperature was maintained at 30 ° C., a solution A obtained by adding distilled water to 22.22 g of silver nitrate to 95.4 ml, and bromide were added. A solution B obtained by diluting potassium (15.3 g) and potassium iodide (0.8 g) to a volume of 97.4 ml with distilled water was added at a constant flow rate over 45 seconds. Thereafter, 10 ml of a 3.5% by mass aqueous solution of hydrogen peroxide was added, and a 10% by mass aqueous solution of benzimidazole was further added to 1 ml.
0.8 ml was added. Further, a solution C obtained by adding 51.86 g of silver nitrate to 317.5 ml by adding distilled water and a solution D obtained by diluting 44.2 g of potassium bromide and 2.2 g of potassium iodide to 400 ml in distilled water were prepared. Solution C was added at a constant flow rate over 20 minutes, and solution D was added by a controlled double jet method while maintaining pAg at 8.1. The total amount of potassium hexachloride iridate (III) was added 10 minutes after starting to add the solution C and the solution D so as to be 1 × 10 ⁻⁴ mol per mol of silver. Five seconds after the completion of the addition of the solution C, iron (II) hexacyanide
An aqueous potassium solution was added in a total amount of 3 × 10 ^-4 mol per mol of silver. The pH was adjusted to 3.8 using 0.5 mol / L sulfuric acid, stirring was stopped, and the sedimentation / desalting / water washing steps were performed. The pH was adjusted to 5.9 with 1 mol / L sodium hydroxide to prepare a silver halide dispersion having a pAg of 8.0.

While stirring the above silver halide dispersion, 3
Maintained at 8 ° C, 0.34% by weight of 1,2-benzoiso
5 ml of a methanol solution of thiazolin-3-one was added,
Molar ratio of spectral sensitizing dye A to spectral sensitizing dye B after 40 minutes
1: 1 methanol solution per mole of silver for spectral sensitization
1.2 × 10 as the sum of elements A and B^-3Add mole, 1 minute
Later, the temperature was raised to 47 ° C. 20 minutes after the temperature rise
Sodium sulfonate to 1 mol silver with methanol solution
7.6 × 10^-FiveMole and tellurium 5 minutes later
Sensitizer C was dissolved in a methanol solution at 2.9 × 1 per mole of silver.
0^-FourMol was added and the mixture was aged for 91 minutes. N, N'-dihydro
0.8% by weight methano of xy-N ″ -diethylmelamine
1.3 ml of ethanol solution, and 4 minutes later, 5-methyl
2-mercaptobenzimidazole in methanol
4.8 × 10 per mole of silver in liquid ^-3Mol and 1-phenyl
Ru-2-heptyl-5-mercapto-1,3,4-tri
The azole is 5.4 × with respect to 1 mol of silver in a methanol solution.
10^-3By molar addition, a silver halide emulsion 1 was prepared.

The grains in the prepared silver halide emulsion are as follows:
Average sphere equivalent diameter 0.042 μm, coefficient of variation of sphere equivalent diameter 20
% Iodine was uniformly contained in 3.5 mol% of silver iodobromide grains. The particle size and the like were determined from the average of 1000 particles using an electron microscope. The {100} plane ratio of the particles was determined to be 80% using the Kubelka-Munk method.

<< Preparation of Silver Halide Emulsion 2 >> In the preparation of silver halide emulsion 1, a liquid temperature of 30 ° C. during grain formation was adjusted to 4 ° C.
The temperature was changed to 7 ° C., the solution B was changed to dilute 15.9 g of potassium bromide to a volume of 97.4 ml with distilled water, and the solution D was prepared by diluting 45.8 g of potassium bromide with a volume of 400 m in distilled water.
The silver halide emulsion 2 was prepared in the same manner except that the dilution was changed to 1 and the addition time of the solution C was changed to 30 minutes to remove potassium hexacyanoferrate (II). Precipitation / desalting / washing / dispersion was carried out in the same manner as in the preparation of silver halide emulsion 1. Further, the addition amount of the methanol solution having a molar ratio of 1: 1 between the spectral sensitizing dye A and the spectral sensitizing dye B is defined as the sum of the spectral sensitizing dye A and the spectral sensitizing dye B per mole of silver.
5 × 10 ^-4 mol, the amount of tellurium sensitizer C added was 1.1 × 10 ^-4 mol per mol of silver, and 1-phenyl-2-heptyl-5-mercapto-1,3,4-triazole was added to silver. Spectral sensitization, chemical sensitization, 5-methyl-2-mercaptobenzimidazole, and 1-molecule were carried out in the same manner as in the preparation of silver halide emulsion 1 except that the amount was changed to 3.3 × 10 ^-3 mol per mol.
-Phenyl-2-heptyl-5-mercapto-1,3,3
By adding 4-triazole, a silver halide emulsion 2 was obtained. The emulsion grains of the silver halide emulsion 2 were pure silver bromide cubic grains having an average equivalent sphere diameter of 0.080 μm and a coefficient of variation in equivalent sphere diameter of 20%.

<< Preparation of Silver Halide Emulsion 3 >> In the preparation of silver halide emulsion 1, the liquid temperature at the time of grain formation was set at 30 ° C.
Except that the temperature was changed to 7.degree.
Was prepared. Precipitation / desalting / washing / dispersion was performed in the same manner as in the preparation of silver halide emulsion 1. Spectral sensitizing dye A
And a spectral sensitizing dye B in a molar ratio of 1: 1 as a solid dispersion (aqueous gelatin solution) in an amount of 6 × 10 ⁻³ as a total of the spectral sensitizing dye A and the spectral sensitizing dye B per mole of silver. Mol, tellurium sensitizer C was added in an amount of 5.2 × per mol of silver.
Silver halide emulsion 3 was obtained in the same manner as in preparation of silver halide emulsion 1 except that the amount was changed to 10 ^-4 mol. The emulsion grains of the silver halide emulsion 3 had an average sphere equivalent diameter of 0.034 μm and iodine having a sphere equivalent diameter variation coefficient of 20% uniformly at 3.5 mol%.
Contained silver iodobromide particles.

<< Preparation of Mixed Emulsion A for Coating Solution >> A silver halide emulsion 1 was dissolved in 70% by mass, a silver halide emulsion 2 was dissolved in 15% by mass, and a silver halide emulsion 3 was dissolved in 15% by mass. 7 × 10 ⁻³ mol per mol of silver was added as a 1% by mass aqueous solution of the amide. Further, the content of silver halide per kg of the mixed emulsion for coating liquid was 38.2 as silver.
g.

<< Preparation of Non-Photosensitive Silver Behenate Dispersion >> CO
Behenic acid (product name EDENOR C22-85JP GW) manufactured by GNIS DEUTSCHLAND GmbH 8
7.6 kg, 423 L of distilled water, 5 mol / L concentration of Na
49.2 L of OH aqueous solution, 120 L of tert-butanol
Were mixed and reacted at 75 ° C. for 1 hour with stirring to obtain a sodium behenate solution. Separately, 206.2 L (pH 4.0) of an aqueous solution of 40.4 kg of silver nitrate was prepared and kept at 10 ° C. A reaction vessel containing 635 L of distilled water and 30 L of tert-butanol was kept at 30 ° C., and while thoroughly stirring, the total amount of the sodium behenate solution and the total amount of the silver nitrate aqueous solution were respectively 93 minutes 15 seconds at a constant flow rate. And 9
Added over 0 minutes. At this time, only the aqueous silver nitrate solution was added for 11 minutes after the start of the addition of the aqueous silver nitrate solution,
Thereafter, the addition of the sodium behenate solution was started, and only the sodium behenate solution was added for 14 minutes and 15 seconds after the completion of the addition of the aqueous silver nitrate solution. At this time, the temperature inside the reaction vessel was set at 30 ° C., and the external temperature was controlled so that the liquid temperature became constant. In addition, the piping of the addition system of the sodium behenate solution is kept warm by circulating hot water outside the double tube, and the liquid temperature at the outlet of the addition nozzle tip is 75 ° C.
It was adjusted to become. The piping of the silver nitrate aqueous solution addition system was kept warm by circulating cold water outside the double pipe. The addition position of the sodium behenate solution and the addition position of the silver nitrate aqueous solution are symmetrically arranged around the stirring axis.
The height was adjusted so as not to contact the reaction solution.

After the completion of the addition of the sodium behenate solution, the mixture was left to stir at the same temperature for 20 minutes, and 35 minutes over 30 minutes.
C., and aging was performed for 210 minutes. Immediately after the ripening, the solid content was separated by centrifugal filtration, and the solid content was washed with water until the conductivity of the filtered water became 30 μS / cm. that time,
The operation of adding pure water to the wet cake to form a slurry was performed three times in order to promote a decrease in electric conductivity. The obtained fatty acid silver wet cake was shaken off at a centrifugal force G of 700 for 1 hour. G is represented by 1.119 × 10 ⁻⁵ × radius of container (cm) × number of rotations (rpm) ² . The solid content (measured by drying 1 g of the wet cake at 110 ° C. for 2 hours) of the non-photosensitive silver behenate wet cake thus obtained was 44%.

The morphology of the obtained silver behenate particles was evaluated by electron microscopic photographing. The average value was a = 0.14 μm.
m, b = 0.4 μm, c = 0.6 μm, an average aspect ratio of 5.2, an average equivalent sphere diameter of 0.52 μm, and a flake-like crystal having a sphere equivalent diameter variation coefficient of 15%. (A, b, c
Is defined in Japanese Patent Application No. 2000-358846.)

To a wet cake having a dry solid content of 260 kg, polyvinyl alcohol (trade name: PVA-2)
17) Add 19.3 kg and water to make the total amount 1000
kg, and then slurried with a dissolver blade, and then a pipeline mixer (Model Mizuho Kogyo: PM-10)
Was predispersed.

Next, the pre-dispersed stock solution was subjected to a dispersing machine (trade name: Microfluidizer M-610, manufactured by Microfluidics International Corporation, using a Z-type interaction chamber) at a pressure of 1
The pressure was adjusted to 2.6 MPa (1260 kg / cm ² ), and the mixture was treated three times to obtain a silver behenate dispersion. In the cooling operation, a coiled heat exchanger was mounted before and after the interaction chamber, and the dispersion temperature was set at 18 ° C. by adjusting the temperature of the refrigerant.

<< Preparation of Dispersion of Reducing Agent Complex-1 >> Reducing Agent Complex-1 (2,2'-methylenebis- (4-ethyl-6-
10 kg of a 1: 1 complex of tert-butylphenol) and triphenylphosphine oxide, 0.12 kg of triphenylphosphine oxide and 10 kg of modified polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.)
7.2 kg of water was added to 16 kg of a mass% aqueous solution and mixed well to form a slurry. The slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 4 hours and 30 minutes, and then benzoisothiazolinone sodium salt was added. 0.2 g and water were added to adjust the concentration of the reducing agent to 25% by mass to obtain a reducing agent complex-1 dispersion. The reducing agent complex particles contained in the thus obtained reducing agent complex dispersion have a median diameter of 0.46 μm,
The maximum particle size was 1.6 μm or less. The resulting reducing agent complex dispersion was filtered through a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion of Organic Polyhalogen Compound-1 >> 10 kg of organic polyhalogen compound-1 (tribromomethanesulfonylbenzene) and 10 kg of a 20% by mass aqueous solution of modified polyvinyl alcohol (Poval MP203, manufactured by Kuraray Co., Ltd.) Then, 0.4 kg of a 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate and 14 kg of water were added and mixed well to form a slurry.
This slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by Imex Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 5 hours, and then sodium benzoisothiazolinone sodium salt was added.
2 g and water are added to make the concentration of the organic polyhalogen compound 2
It was adjusted to 6% by mass to obtain an organic polyhalogen compound-1 dispersion. The organic polyhalogen compound particles contained in the organic polyhalogen compound dispersion thus obtained had a median diameter of 0.41 μm and a maximum particle diameter of 2.0 μm or less. The resulting organic polyhalogen compound dispersion has a pore size of 1
Filtration was performed with a 0.0 μm polypropylene filter to remove foreign substances such as dust, and stored.

<< Preparation of Dispersion of Organic Polyhalogen Compound-2 >> 10 kg of chronological polyhalogen compound-2 (N-butyl-3-tribromomethanesulfonylbenzamide) and modified polyvinyl alcohol (Poval M, manufactured by Kuraray Co., Ltd.)
20 kg of a 10% by mass aqueous solution of P203), 0.4 kg of a 20% by mass aqueous solution of sodium triisopropylnaphthalenesulfonate, and 8 kg of water were added and mixed well to form a slurry. The slurry was sent by a diaphragm pump and dispersed in a horizontal sand mill (UVM-2: manufactured by IMEX Co., Ltd.) filled with zirconia beads having an average diameter of 0.5 mm for 5 hours, and then benzoisothiazolinone sodium salt was added. 2 g and water were added to adjust the concentration of the organic polyhalogen compound to 25% by mass. This dispersion was heated at 40 ° C. for 5 hours to obtain an organic polyhalogen compound-2 dispersion. The organic polyhalogen compound particles contained in the polyhalogen compound dispersion thus obtained had a median diameter of 0.36 μm and a maximum particle diameter of 1.5 μm or less. The obtained organic polyhalogen compound dispersion was filtered with a polypropylene filter having a pore size of 3.0 μm to remove foreign substances such as dust, and stored.

<< Preparation of Phthalazine Compound-1 Solution >> 8k
g modified Kuraray Co., Ltd. modified polyvinyl alcohol MP20
Was dissolved in 174.57 kg of water, and then 3.15 kg of a 20% by weight aqueous solution of sodium triisopropylnaphthalenesulfonate and 14.28 kg of a 70% by weight aqueous solution of phthalazine compound-1 (6-isopropylphthalazine).
Was added to prepare a 5% by mass solution of phthalazine compound-1.

<< Preparation of Aqueous Solution of Mercapto Compound-1 >> Mercapto Compound-1 (1- (3-sulfophenyl) -5
7 g of mercaptotetrazole sodium salt) in water 99
3 g to give a 0.7% by mass aqueous solution.

<< Preparation of Pigment-1 Dispersion >> I. Pig
250 g of water was added to 64 g of Ment Blue 60 and 6.4 g of Demol N manufactured by Kao Corporation, and mixed well to form a slurry. 800 g of zirconia beads having an average diameter of 0.5 mm was prepared, put into a vessel together with the slurry, and dispersed for 25 hours with a dispersing machine (1/4 Gallon sand grinder mill: manufactured by Imex Co., Ltd.) to obtain a pigment-1 dispersion. Obtained. The pigment particles contained in the pigment dispersion thus obtained had an average particle size of 0.21 μm.

<< Preparation of SBR Latex Liquid >> Tg = 23
C. SBR latex was prepared as follows. Using ammonium persulfate as a polymerization initiator and an anionic surfactant as an emulsifier, 70.5 mass% of styrene, 26.5 mass% of butadiene and 3 mass% of acrylic acid are emulsion-polymerized, and then aged at 80 ° C. for 8 hours. went. Then 4
Cooled to 0 ° C, adjusted to pH 7.0 with aqueous ammonia,
Further, Sandet BL manufactured by Sanyo Chemical Industries, Ltd. was added so as to be 0.22%. Next, a 5% aqueous sodium hydroxide solution was added to adjust the pH to 8.3, and the pH was further adjusted with aqueous ammonia.
Adjusted to H8.4. Na used at this time
The molar ratio of ⁺ ions to NH ₄ ⁺ ions was 1: 2.3. Further, 0.15 ml of a 7% aqueous solution of sodium salt of benzoisothiazolinone was added to 1 kg of this solution, and SB was added.
An R latex solution was prepared.

(SBR latex: -St (70.5)
-Bu (26.5) -AA (3)-latex) Tg
23 ° C. Average particle size 0.1 μm, concentration 43 mass%, equilibrium water content at 25 ° C., relative humidity 60% 0.6 mass%, ion conductivity 4.2 mS / cm (Ion conductivity was measured by Toa Denpa Kogyo ( Using a conductivity meter CM-30S manufactured by Co., Ltd., a latex stock solution (43% by mass) was measured at 25 ° C.). Prepared by

<< Preparation of Emulsion Layer (Photosensitive Layer) Coating Solution-1 >>
1000 g of the non-photosensitive silver behenate dispersion obtained above,
04 ml, organic polyhalogen compound-1 dispersion 21 g,
69 g of organic polyhalogen compound-2 dispersion, 173 g of phthalazine compound-1 solution, SBR latex (Tg: 2
3 ° C.) 1082 g of liquid, 258 g of reducing agent complex-1 dispersion,
9 g of a mercapto compound-1 solution was sequentially added, and 110 g of a mixed emulsion A for a silver halide coating solution was added immediately before coating.
Mix well.

The viscosity of the above emulsion layer coating solution was measured at 40 ° C. (No. 1 rotor, 60 rpm
pm) was 85 [mPa · s].

25 ° C. using an RFS fluid spectrometer manufactured by Rheometrics Far East Co., Ltd.
The viscosity of the coating solution at the shear rate is 0.1, 1, 10, 1
For 00 and 1000 [1 / sec], 150
0, 220, 70, 40, and 20 [mPa · s].

<< Preparation of Coating Solution for Intermediate Layer of Photosensitive Layer >> Polyvinyl alcohol PVA-205 (manufactured by Kuraray Co., Ltd.)
772 g of a 0% by mass aqueous solution, 5.3 g of a 20% by mass dispersion of Pigment-1 and a methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymerization mass ratio of 64/9/20/5/2) )
Aerosol O is added to 226 g of latex 27.5 mass% liquid.
2 ml of a 5 mass% aqueous solution of T (manufactured by American Cyanamid Co.), 10.5 ml of a 20 mass% aqueous solution of diammonium phthalate, and water were added so that the total amount was 880 g.
The solution was adjusted with NaOH so that the pH became 7.5, and the solution was applied to an intermediate layer so as to be 10 ml / m ² . The viscosity of the coating solution is 40 ° C (N
o. It was 21 [mPa · s] with one rotor at 60 rpm.

<< Preparation of Coating Solution for First Layer of Photosensitive Layer Protective Layer >>
64 g of inert gelatin was dissolved in water, and 27.5% by mass of methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20/5/2) latex was used.
80 g of the liquid, a 10% by mass methanol solution of phthalic acid
ml, a 10% by weight aqueous solution of 4-methylphthalic acid in 23 m
1, 28 ml of sulfuric acid having a concentration of 0.5 mol / L, 5 ml of a 5% by mass aqueous solution of aerosol OT (manufactured by American Cyanamid), 0.5 g of phenoxyethanol, and 0.1 g of benzoisothiazolinone were added. Further, a solution adjusted to a total amount of 776 g with water was used as a coating solution for the first layer of the surface protective layer, and was fed to a coating die at 18.6 ml / m ² . The viscosity of the coating solution was 17 mP with a B-type viscometer at 40 ° C. (No. 1 rotor, 60 rpm).
a · s].

<< Preparation of Coating Solution for Second Layer of Photosensitive Layer Protective Layer >>
80 g of inert gelatin is dissolved in water, and 27.5% by mass of methyl methacrylate / styrene / butyl acrylate / hydroxyethyl methacrylate / acrylic acid copolymer (copolymer mass ratio 64/9/20/5/2) latex
Liquid, 102 g, 3.2 ml of a 5% by mass solution of a fluorine-based surfactant (F-4: potassium N-perfluorooctylsulfonyl-N-propylalanine), and a fluorine-based surfactant (F-1: polyethylene glycol mono) (N-perfluorooctylsulfonyl-N-propyl-2-aminoethyl) ether [average degree of polymerization of ethylene oxide =
15]), 32 ml of a 2% by mass aqueous solution of aerosol O
A 5% by mass solution of T (manufactured by American Cyanamid) was added to 2
3 ml, polymethyl methacrylate fine particles (average particle diameter 0.7 μm) 4 g, polymethyl methacrylate fine particles (average particle diameter 4.5 μm) 21 g, 4-methylphthalic acid 1.6 g, phthalic acid 7.8 g, 0.5 mol / L concentration Of sulfuric acid and 10 mg of benzoisothiazolinone were added. Further, the solution adjusted to a total amount of 1095 g with water was used as a coating solution for the second layer of the surface protective layer, and 8.3 ml.
/ M ² to the coating die. The viscosity of the coating solution was measured using a B-type viscometer at 40 ° C (No. 1 rotor, 60
rpm] was 9 [mPa · s].

<< Preparation of Photothermographic Materials-1 to 10 >> An antihalation layer coating solution was coated on the back surface side of the undercoat support so that the gelatin coating amount was 0.44 g / m ^2, and the back surface was protected. The amount of gelatin applied to the layer coating solution was 1.
Coating was applied simultaneously to form a layer of 7 g / m ² and dried to form a back layer. Table 1 shows the contents of the levels of the photosensitive materials 1 to 10.

The photosensitive layer, the intermediate layer, the protective layer first layer, and the protective layer second layer were simultaneously coated on the surface opposite to the back surface in the order of the photosensitive layer, the intermediate layer, the first protective layer, and the second protective layer by slide bead coating. A sample was prepared. At this time, the temperature of the photosensitive layer and the intermediate layer was 31 ° C., the temperature of the first protective layer was 36 ° C., and the temperature of the second protective layer was 3 ° C.
The temperature was adjusted to 7 ° C. Coating amount of each compound in the photosensitive layer (g
/ M ² ) is as follows.

• Silver behenate 6.19 • Organic polyhalogen compound-1 0.13 • Organic polyhalogen compound-2 0.41 • Phthalazine compound-1 0.21 • SBR latex 11.1 • Reducing agent complex-1 1.54-mercapto compound-1 0.002-silver halide (as Ag) 0.10

The coating and drying conditions are as follows. The coating was performed at a speed of 160 m / min, the gap between the tip of the coating die and the support was set to 0.10 to 0.30 mm, and the pressure in the decompression chamber was set 196 to 882 Pa lower than the atmospheric pressure. The support was neutralized with ion wind before coating. In the subsequent chilling zone, the coating liquid is cooled by air having a dry-bulb temperature of 10 to 20 ° C., and is transferred in a non-contact type. It was dried with a dry air having a wet bulb temperature of 15 to 21 ° C. After drying, 25 ° C
After adjusting the humidity at 40 to 60% relative humidity at 80 ° C.
Heated for seconds. After heating, the film surface was cooled to 25 ° C.

The matte degree of the produced photothermographic material was as follows:
The Beck smoothness was 550 seconds on the photosensitive layer side and 1 on the back side.
30 seconds. Further, the pH of the film surface on the photosensitive layer surface side was measured and found to be 6.0. In order to confirm the effects of the present invention, all the photosensitive materials used in the experiments were conditioned at 25 ° C. and a relative humidity of 50%, sealed in a moisture-proof bag, and allowed to stand for 14 days before the experiment.

Hereinafter, the chemical structures of the compounds used in the examples of the present invention are shown.

[0221]

Embedded image

[0222]

Embedded image

[0223]

Embedded image

[0224]

Embedded image

[0225]

Embedded image

<Method of Measuring Water Swelling Value> The swelling ratio of each photosensitive material was measured. As a method of measuring the swelling value, the photosensitive material is immersed in distilled water at 25 ° C. for 30 seconds, frozen in liquid nitrogen, cut in a microtome so as to be perpendicular to the material surface, and further cut. It freeze-dried at -90 degreeC, observed with the scanning electron microscope, and measured the swollen film thickness Tw. On the other hand, the cross section of the dry film thickness Td was also measured by a scanning electron microscope. Tw and Td obtained in this way
The value obtained by dividing the difference from Td by Td and multiplying by 100 was defined as the swelling ratio (unit%). Table 1 shows the measurement results.

<Evaluation of Haze Property> Fuji Medical Dry Laser Imager FM-DP L (60 mW max.)
(IIIB) 660 nm semiconductor laser output) to expose and heat develop each photosensitive material (112 ° C-119 ° C-12
4 panel heaters set at 1 ° C-121 ° C for a total of 2
4 seconds), and the obtained image was subjected to a sensory evaluation of the haze property of the Dmin part (minimum density part). The evaluation criteria are as follows, and the evaluation results are shown in Table 1. ：: High transparency, very favorable level. ：: Transparent and preferable level. Δ: Very weak scattering, but not practically a problem. X: The level at which scattering properties are clearly recognized and are problematic.

<Evaluation of Remaining Color> Fuji Medical Dry Laser Imager FM-DP L (max. 60 mW (II
IB) Each photosensitive material is exposed and thermally developed (112 ° C.-119 ° C.-121 ° C.) with an output of 660 nm semiconductor laser).
12 seconds in total with 4 panel heaters set at -121 ° C (film transport speed was adjusted to 12 seconds)
Then, in the obtained image, a Dmin part (minimum density part)
Was evaluated organoleptically for residual color. The evaluation criteria are as follows, and the evaluation results are shown in Table 1. ：: No residual color is observed at the center of the film and at the rear end of the film, which is a very preferable level. ：: No residual color is observed at the center of the film, but there is some residual color at the rear end of the film, but at a preferable level. Δ: There is some residual color in the whole film, but there is no practical problem. ×: The residual color is clearly seen, and there is a problem.

[0229]

[Table 1]

[0230]

According to the present invention, it is possible to provide a photothermographic material having high transparency (small haze) and capable of rapidly decoloring a dye in heat development.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a plate heater type thermal developing device.

FIG. 2 is a schematic cross-sectional view of a plate heater type thermal developing device having a driving roller.

[Explanation of symbols]

 Reference Signs List 18 heat developing section 120 plate heater 122 press roller 125 heat retaining cover 126 supply roller pair 128 discharge roller pair 130 drive roller

Claims (4)

[Claims] 1. A support having at least one photosensitive layer on one side of a support and at least one non-photosensitive layer containing gelatin on the opposite side, wherein the non-photosensitive layer is provided. On the surface side, a dye bleachable by a base or a salt thereof,
A base precursor and 2 represented by the following general formula (A)
-A photothermographic material comprising a water-soluble or water-dispersible polymer having an oxazoline group. Embedded image (In the formula, R ₁ , R ₂ , R ₃ and R ₄ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, a phenyl group or a substituted phenyl group.) 2. The photothermographic material according to claim 1, wherein at least one of the non-photosensitive layers simultaneously contains a dye bleachable by a base or a salt thereof, and a base precursor. 3. The value obtained by dividing the swelling value of the film thickness when immersed in distilled water at 25 ° C. for 30 seconds by the film thickness in a dry state (swelling ratio) is 30% or more and 130% or less. Or 2
2. The photothermographic material according to item 1. 4. The method according to claim 1, wherein a value obtained by dividing the coating amount of the base precursor by the coating amount of gelatin of the non-photosensitive layer containing the base precursor is 20% by mass or more and 70% by mass or less. 2. The photothermographic material according to item 1.