JP2003241337A - Photothermographic imaging material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photothermographic imaging material ensuring high sensitivity and low fog, inhibited from fogging due to printed-out silver after development, excellent in raw stock preservability before development and in image preservability after development and having little residual color and a stable color tone after development. <P>SOLUTION: In the photothermographic imaging material having on a support a photosensitive layer comprising photosensitive silver halide grains, an organic silver salt, a developer and a binder, a maleimide compound is contained, a phthalazin compound is further contained in the photosensitive layer or a layer adjacent to the photosensitive layer, a binder forming the photosensitive layer or the adjacent layer has been crosslinked with a crosslinking agent and this crosslinking agent is selected from isocyanate compounds, vinylsulfone compounds and epoxy compounds. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic image forming material which forms an image by thermal development, and more particularly to a photothermographic image forming material which can obtain high sensitivity and low fog and has excellent storage stability. Further, the present invention relates to a photothermographic image forming material which has excellent storability of an image obtained after development, has improved residual color after development, and has suppressed fog due to printout silver.

[0002]

2. Description of the Related Art In recent years, a photothermographic material that does not produce waste liquid associated with a wet process has been strongly desired in the fields of medical treatment and printing from the viewpoint of environmental protection and workability. There is a need in the art for photothermographic materials for photographic applications that are capable of forming images. Since these photothermographic materials are usually developed at a temperature of 80 ° C. or higher, they are called photothermographic image forming materials.

This type of photothermographic image-forming material has hitherto been irradiated onto a photosensitive layer containing a highly sensitive silver halide grain spectrally sensitized with a dye, an organic silver salt and a developer, and the photosensitive layer. It is composed of an irradiation prevention layer (AI layer) that prevents light from passing through without being absorbed and diffused reflection at an interface of the support, an intermediate layer or an adhesive layer, or a backing layer (BC layer) provided on the opposite side of the support. , On the photosensitive layer and BC
A protective layer is provided on the layer to prevent scratching during handling.

Generally, the photothermographic image-forming material is easy to process because it forms an image only by heat development after exposure. However, since there is no fixing step, it is an important subject to improve the storability of the image after development. In order to improve the storability after development, it is general to develop the image at a high temperature so that an image appears, but if the temperature is too high, fog is likely to occur and the sensitivity decreases. Therefore, generally 120 ° C
Development is carried out at a temperature around ± 10 ° C. The use of a mercapto compound to reduce fog is disclosed in JP-A-63 / 1988.
-301037, JP-A-5-341432, 5-
509182 and Japanese Patent Laid-Open No. 2000-19681. However, in all cases, the mercapto compound is less effective in suppressing fog, and it is difficult to obtain high sensitivity, and there is a limit in improving storage stability. The use of a phthalazine compound for suppressing printed silver is disclosed in JP-A-50-67132.
No. 61-183642, JP-A-9-114036.
No. 9, No. 258366, No. 10-508599, No. 10-339931, No. 11-49756, No. 11
No. 218877, No. 11-223900, JP 20
00-10234, 2000-10232 and 200
0-35630 and the like. It is described that all of them are improved in fog, sensitivity, concentration, storability and the like by using together with a phthalazine compound or an additive other than the phthalazine compound.

However, it does not describe the effect of using a maleimide compound or using the compound and a phthalazine compound in combination. A polyhalomethane compound is effective for suppressing bake-out silver after development.
244177, 9-265150 and 9-31
No. 9022 describes that use of a compound having a specific structure has effects such as raw storability, image storability, color tone, and suppression of printout silver, but the effect is not yet sufficient. Attempts have been made to improve the cross-linking of the binder by improving the pH and the combined use of the cross-linking agent as an improvement in storage stability, but this is not sufficient.

[0006]

SUMMARY OF THE INVENTION It is a first object of the present invention to provide a photothermographic image forming material excellent in high sensitivity and low fog in photographic performance. A second object of the present invention is to provide a photothermographic image forming material in which fogging due to printed silver after development is suppressed. A third object of the present invention is to provide a photothermographic image forming material which is excellent in raw storability before development and image storability after development, and has little residual color after development and stable color tone. Especially.

[0007]

The photothermographic image-forming material according to the first aspect of the present invention (the photothermographic image-forming material according to claim 1) comprises a photosensitive silver halide grain, an organic silver salt, and A photothermographic image-forming material having a photosensitive layer containing a developer and a binder, characterized by containing a maleimide compound.

According to the photothermographic image forming material of the first aspect of the present invention, it is possible to provide a photothermographic image forming material having excellent photographic performance (sensitivity and fog characteristics) during heat development and storage stability.

The photothermographic image-forming material according to the second aspect of the present invention (the photothermographic image-forming material according to claim 2) comprises photosensitive silver halide grains, an organic silver salt, a developer and a binder on a support. A photothermographic image-forming material having a photosensitive layer that contains a maleimide compound, and further contains at least one selected from a phthalazine compound, a polyhalomethane compound and a bisphenol compound in the photosensitive layer or a layer adjacent to the photosensitive layer. It is characterized by.

According to the photothermographic image forming material of the second aspect of the present invention, a photothermographic image forming material having further improved photographic performance (sensitivity and fog characteristics) and storability during thermal development can be provided.

The photothermographic image-forming material according to the third aspect of the present invention (the photothermographic image-forming material according to claim 3) comprises photosensitive silver halide grains, an organic silver salt, a developer and a binder on a support. A photothermographic image-forming material having a photosensitive layer containing a maleimide compound, further containing a phthalazine compound in the photosensitive layer or a layer adjacent to the photosensitive layer, and forming the photosensitive layer or the adjacent layer The binder is cross-linked with a cross-linking agent, and the cross-linking agent is at least one cross-linking agent selected from an isocyanate compound, a vinyl sulfone compound and an epoxy compound.

According to the photothermographic image forming material of the third aspect of the present invention, in addition to further improvement in photographic performance (sensitivity and fog characteristics) and storability at the time of heat development, fog caused by sliver of silver after storage (printed silver) Fog), and a photothermographic image forming material having an improved residual color after development can be provided.

Further, in the first to third inventions, more preferable results are obtained when the maleimide compound is selected from the compounds represented by the general formula (M1) or the general formula (M2).

The present invention will be described in detail below. The photothermographic image-forming material of the present invention is usually composed of at least one photosensitive layer on a support and at least two layers having a layer adjacent to the photosensitive layer, which is opposite to the photosensitive layer. A BC layer provided on the side, a protective layer thereof, and the like are included.
Further, the above photothermographic image forming material is provided with an AI layer containing a dye for preventing irradiation or for preventing halation, if necessary.

The light-sensitive layer of the photothermographic image-forming material contains light-sensitive silver halide grains which may be sensitized with a spectral sensitizing dye, and the light-sensitive layer or its adjacent layer contains a silver source. And an organic silver salt, a developer for developing a silver salt to form a silver image, and a maleimide compound according to the present invention. When the photothermographic image forming material is manufactured, the maleimide compound according to the present invention can be contained in the BC layer. Generally, photothermographic image-forming materials are stored in roll form or in sheet form cut to an appropriate size, but the maleimide compound contained in the BC layer diffuses into the photosensitive layer during storage. it is conceivable that.

Further, a binder such as a polymer binder, a hydrophilic binder or a hydrophobic binder, which provides a field for a heat development reaction, is provided on the photosensitive layer of the photothermographic image-forming material or a layer adjacent to the photosensitive layer. Is contained, and more preferably, an isocyanate compound, a vinyl sulfone compound, an epoxy compound or the like that cross-links and cures the binder is contained.

The maleimide compound, phthalazine compound, polyhalomethane compound, bisphenol compound and crosslinking agent contained in the photothermographic image-forming material of the present invention will be described below in order. Further, the photosensitive silver halide grains contained in the photosensitive layer of the photothermographic image forming material, the organic silver salt contained in the photosensitive layer or its adjacent layer, the developer, the binder contained in the photosensitive layer or its adjacent layer. Etc. will be described later.

(Maleimide Compound) The maleimide compound according to the present invention will be described. The maleimide compound according to the present invention is a compound having at least one maleimide ring in the molecular structure, preferably a compound having two maleimide rings, and more preferably a bis-body structure maleimide compound. When the molecular structure has two or more maleimide rings, a compound in which an alkylenecarbonyloxy group is bonded to the maleimide ring (the alkylene part of the alkylenecarbonyloxy group is bonded to the nitrogen atom of the maleimide ring) is preferable.

The maleimide compound according to the present invention is typically a compound represented by the above general formula (M1) or general formula (M2). In the general formula (M1), X ₁ and Y are
Each represents a simple bond, an alkylene group or an alkylenecarbonyloxy group (the alkylene moiety is bonded to the nitrogen atom of the maleimide ring). This alkylene group and alkylenecarbonyloxy group may have a substituent. L
Represents a (m + n) -valent linking group. m and n are 1
Represents an integer of 5 (provided that 2 ≦ m + n ≦ 6). L is 2
When it is a valent linking group, L is preferably polyalkylene oxide or 2,4,8,10-tetraoxaspiro [5,5] undecane-3,9-bisalkylene. A linking group containing a triazine ring is also preferable.

In the general formula (M2), X ₂ has the same meaning as X ₁ . R represents a monovalent organic group. Examples of the monovalent organic group include an alkyl group, a cycloalkyl group, an aryl group and a heterocyclic group. The alkyl group, cycloalkyl group, aryl group and heterocyclic group may each have a substituent.

Specific examples of the maleimide compound according to the present invention are shown below, but the present invention is not limited thereto.

[0022]

[Chemical 2]

[0023]

[Chemical 3]

[0024]

[Chemical 4]

The synthesis of the maleimide compound according to the present invention is
It is known to those skilled in the art. For example, a synthetic reaction (a): a compound having an amino group at the terminal and a maleic anhydride synthetic reaction (b): an aldehyde or ketone having a maleimide group at the terminal and a pentaerythritol synthetic reaction (c): a maleimide compound having a carboxyl group It can be easily synthesized from a compound having a hydroxyl group at the terminal using a known technique.

Regarding the synthetic reaction (a), a known technique such as ZY Wan can be used to synthesize maleic anhydride and a compound having an amino group at the terminal.
g), "Synthetic Communications (Sy
nth. Comm. ) Volume 20, 1607-161
It can be synthesized with reference to page 0 (1990).
The compound having an amino group at the terminal can be obtained by a known technique such as M-Renol (MR) from an aldehyde or ketone having an amino group at the terminal and pentaerythritol.
Enol) et al., "Organic Synthesis" III
Vol. 502 (1955). Examples of the compound having an amino group at the terminal include 3,9-bis (aminomethyl) -2,4,8,1
0-Tetraoxaspiro [5,5] undecane, 3,9
-Bis (2-aminoethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro Examples include, but are not limited to, [5,5] undecane and 3,9-bis (diaminomethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane.

Regarding the synthetic reaction (b), a known technique such as M. Renol et al., "Organic Synthesis", Vol. III, aldehyde or ketone having a maleimide group at the terminal and pentaerythritol is used. It can be synthesized with reference to page 502 (1955). As the aldehyde or ketone having a maleimide group at the terminal, any aldehyde or ketone having a maleimide group at the terminal can be used. Examples of such aldehydes or ketones include maleimidoacetaldehyde, bis (maleimidomethyl) ketone, maleimidoacetic acid 4-formylphenyl,
Examples thereof include bis (5-maleimidopentanoic acid) 2-oxopropyl and the like, but are not limited thereto.

The maleimide compound having a carboxyl group used in the synthesis reaction (c) can be synthesized by the technique disclosed in European Patent Publication 878,482. The compound having a hydroxyl group at the terminal used in this reaction can be prepared by a known technique, for example, M. Renol (M.
Renoll) et al. "Organic Synthesis" Part II
Volume I, page 502 (1955), can be used for synthesis.

Examples of the method for adding these synthesized maleimide compounds include dissolving them in alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone and acetone, and polar solvents such as dimethyl sulfoxide and dimethylformamide. There are ways to do it.
Also, sand mill dispersion, jet mill dispersion, ultrasonic dispersion,
1μm of maleimide compound by homogenizer dispersion
The following fine particles may be dispersed and added in water or an organic solvent. The amount of addition is preferably in the range of 1/1000 to 60% by mass in the coating liquid, preferably 10% by mass.
The range of 1/30% by mass to 30% by mass is particularly preferable, and the amount of addition can be appropriately adjusted and used in this range.
When it is added in the number of moles, it is preferably added at 1 × 10 ⁻⁶ to 1 × 10 ⁻² mol / m ² .

The maleimide compound according to the present invention comprises the constituent layers (photosensitive layer, layers adjacent to the photosensitive layer (protective layer, AI layer, etc.)) and BC constituting the photothermographic image-forming material according to the present invention.
Layer, a protective layer for BC layer, etc.). It is preferably a photosensitive layer or a layer adjacent to the photosensitive layer.

(Phthalazine Compound) The phthalazine compound according to the present invention can be obtained by introducing various substituents into the phthalazine ring.

Preferred phthalazine compounds are represented by the general formula (2)
Can be shown as

[0033]

[Chemical 5]

In the formula, R ^{2 to} R ⁷ are each a hydrogen atom, a halogen atom, a cyano group, a hydroxyl group or an optionally substituted alkyl group, alkenyl group, akinyl group, alkoxy group, alkylthio group, It represents an alkylacylamino group, an arylsulfonamide group, an aryl group or a heterocyclic group. It may be a group that controls the diffusibility as a function of the substituent, a non-diffusible group, a diffusible group, an adsorptive group, an acidic group, or the like. The carbon number of the alkyl group and the alkoxy group is preferably 1 to 60, more preferably 1 to 40, and further preferably 1 to 12. The carbon number of the alkenyl group and alkynyl group is preferably 3 to 60, more preferably 3 to 40, and further preferably 3 to 1
It is 2. When the number of carbon atoms is large, good effects in fog control, color tone and storability cannot be obtained. Specific examples of preferable phthalazine compounds are shown below.

[0035]

[Chemical 6]

The addition amount of the phthalazine compound according to the present invention is 1 × 10 ^-6 mol to 1 × 1 mol per mol of silver halide.
It can be added in the range of 0 ^-2 mol. The position of addition is a photosensitive layer in which silver halide is present or a layer adjacent to the photosensitive layer, and preferably an adjacent layer such as a protective layer or an AI layer. The addition method can be the same as that for the maleimide compound.

(Polyhalomethane Compound) The polyhalomethane compound used in the present invention is a compound having at least one trihalomethyl group in the molecule. The trihalomethyl group is bonded to the aliphatic moiety, aromatic ring or heterocycle in the molecule directly or via a linking group.

A typical structure of the polyhalomethane compound according to the present invention is represented by the following general formula (3).

[0039]

[Chemical 7]

In the formula, Z ₂ represents a ring group, and X ¹ , X ² and X ³
Are each a hydrogen atom, a halogen atom, a haloalkyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, a carbamoyl group, a sulfamoyl group, a sulfonyl group or a heterocyclic group, and more preferably a halogen atom, a haloalkyl group, an acyl group. Represents an alkoxycarbonyl group, an aryloxycarbonyl group or a sulfonyl group, at least one of which is a halogen atom. L ₁ represents a divalent linking group, and p represents 0 or 1.

The ring group represented by Z ₂ may be a saturated or unsaturated monocyclic ring or a condensed ring, and preferably has 6 to 3 carbon atoms.
A monocyclic or bicyclic group of 0 (eg, adamantyl group, cyclobutane group, cyclopropane group, cyclopentane group, cyclooctane group, cyclobutene group, cyclopentene group, cyclohexene group, phenyl, naphthyl, etc.), and more preferably adamantyl Group, cyclopentane group, cyclohexane group, cyclohexene group, cyclohexanone group,
A cyclopentene group, a phenyl group or a naphthyl group,
More preferably, it is a phenyl group. The heterocyclic ring represented by Z ₂ is a 3- to 10-membered saturated or unsaturated heterocyclic group containing at least one atom of N, O or S, which may be a monocyclic ring. It may form a condensed ring with another ring. The heterocyclic group is preferably a 5- or 6-membered saturated or unsaturated heterocyclic group which may have a condensed ring, and more preferably 5- or 6-membered aromatic which may have a condensed ring. It is a heterocyclic group.
More preferably a 5- or 6-membered saturated or unsaturated heterocyclic group which may have a condensed ring containing a nitrogen atom,
Particularly preferred is a 5- to 6-membered unsaturated heterocyclic group which may have a condensed ring containing 1 to 4 nitrogen atoms. As the hetero ring in such a hetero ring group,
Imidazole, pyrazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, indole, phosphorene, purine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, acridine, phenanthroline, phenazine, tetrazole, Thiazole, oxazole, benzimidazole,
Examples thereof include benzoxazole, benzothiazole, indolenine and tetrazaindene. Among these, preferred are imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, oxadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, oxazole, benzimidazole, benzo. Oxazole, benzothiazole, tetrazaindene, more preferably imidazole, pyridine, pyrimidine, pyrazine, pyridazine, triazole, triazine, thiadiazole, quinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, tetrazole, thiazole, benzimidazole, benzo. Thiazole, particularly preferably pyridine, triazine, thiadiazole, quinoline, and benzene. Is Zochiazoru.

The ring group represented by Z ₂ is-(L ₁ ) _p -C
It may have any substituent other than (X ¹ ) (X ² ) (X ³ ), and the substituent is preferably an alkyl group, an alkenyl group, an aryl group, an alkoxy group, an aryloxy group, an acyloxy group. , Acyl group, alkoxycarbonyl group, aryloxycarbonyl group, acyloxy group, acylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, sulfonyl group, ureido group, phosphoramide group , A halogen atom, a cyano group, a sulfo group, a carboxyl group, a nitro group, a heterocyclic group, more preferably an alkyl group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an acylamino group,
Alkoxycarbonylamino group, aryloxycarbonylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, ureido group, phosphoric acid amide group, halogen atom, cyano group, nitro group, heterocyclic group,
More preferably alkyl group, aryl group, alkoxy group, aryloxy group, acyl group, acylamino group, sulfonylamino group, sulfamoyl group, carbamoyl group, halogen atom, cyano group, nitro group, heterocyclic group, and particularly preferably An alkyl group, an aryl group, and a halogen atom.

X ¹ , X ² and X ³ are preferably halogen atoms, haloalkyl groups, acyl groups, alkoxycarbonyl groups, aryloxycarbonyl groups, carbamoyl groups, sulfamoyl groups, sulfonyl groups and heterocyclic groups, and more preferably A halogen atom, a haloalkyl group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, and a sulfonyl group are more preferable, a halogen atom and a trihalomethyl group are more preferable, and a halogen atom is particularly preferable. Among the halogen atoms, chlorine atom, bromine atom and iodine atom are preferable, chlorine atom and bromine atom are more preferable, and bromine atom is particularly preferable.

L ₁ is -O-, -S-, -C (= O)-,
-COO -, - SO -, - SO 2 -, - CH 2 CH 2 - or -CF ₂ CF ₂ - represents a.

Among the polyhalomethane compounds according to the present invention,
Also particularly preferred compounds are -C (X ¹) (X²) (X³)
Is a trihalomethyl group, Z₂Is a heterocyclic group (Hete
Especially preferred as the heterocycle of the ring group is quinoline.
Ring, triazine ring, pyridine ring, benzoxazole
Ring, benzothiazole ring) or aromatic ring group (aromatic
The aromatic ring of the aromatic ring group is preferably a benzene ring.
And p is 0 or p is 1 and L₁But-
SO₂-, -COO-, -C (= O)-, and -SO-
(Especially -SO₂-Is preferred).

Specific examples of the polyhalomethane compound according to the present invention are shown below, but the invention is not limited thereto.

[0047]

[Chemical 8]

[0048]

[Chemical 9]

[0049]

[Chemical 10]

The addition amount of the polyhalomethane compound according to the present invention is 1 × 10 ^-6 mol to 1 × per mol of silver halide.
It can be added in the range of 10 ^-2 mol. The position of addition is a photosensitive layer in which silver halide is present or a layer adjacent to the photosensitive layer, and preferably an adjacent layer such as a protective layer or an AI layer. The addition method can be the same as that for the maleimide compound.

(Bisphenol Compound) The bisphenol compound used in the present invention is preferably a compound represented by the following general formula (4).

[0052]

[Chemical 11]

In the formula, R is a hydrogen atom or a carbon atom number of 1 to 1.
0 represents an alkyl group (eg, butyl group, 2,4,4-trimethylpentyl group, etc.), and R ′ and R ″ represent an alkyl group having 1 to 5 carbon atoms (eg, methyl group, ethyl group,
t-butyl group).

Specific examples of the bisphenol compound according to the present invention are shown below, but the invention is not limited thereto.

[0055]

[Chemical 12]

[0056]

[Chemical 13]

The addition amount of the bisphenol compound according to the present invention is preferably 1 × 10 ^-2 to 10 mol per mol of silver,
In particular, it is 1 × 10 ^{-2 to} 1.5 mol. The position to add is
It is a light-sensitive layer in which silver halide is present or a layer adjacent to the light-sensitive layer, preferably a protective layer, an AI layer or the like.
The addition method can be the same as that for the maleimide compound.

(Crosslinking Agent) In the third invention, a crosslinking agent selected from an isocyanate compound, a vinyl sulfone compound and an epoxy compound is used. This naturally improves the film physical properties such as film adhesion and film strength of the film formed by the binder, but the photographic performance (sensitivity and fog characteristics) during heat development and storage stability are improved. In addition to the further improvement, it was found that the effects peculiar to the photothermographic image-forming material, such as the fog (printed fog) due to the printed silver during storage and the residual color after development, can be improved.

The cross-linking agent according to the present invention cross-links a binder forming a photosensitive layer or a layer adjacent to the photosensitive layer, and is added to the photosensitive layer or an adjacent layer (protective layer, AI layer, etc.). Can be used. From the viewpoint of the stability of the coating liquid, it is preferable to add it using a static mixer immediately before coating, but it may be added at the time of preparing the coating liquid.

The crosslinking agent according to the present invention is an isocyanate compound, a vinyl sulfone compound or an epoxy compound, and a particularly preferable crosslinking agent is an isocyanate compound having at least two isocyanate groups.

These cross-linking agents according to the present invention are well known to those skilled in the art. For example, JP-A-7-145141.
No. 2001-3659, etc. can be referred to.

Specific examples of the crosslinking agent according to the present invention are shown below, but the invention is not limited thereto.

[0063] (H1) Hexamethylene diisocyanate (H2) Hexamethylene diisocyanate trimer (H3) Tolylene diisocyanate (H4) Phenylene diisocyanate (H5) Xylylene diisocyanate

[0064]

[Chemical 14]

Next, the organic silver salt, the developer, the photosensitive silver halide grain, the spectral sensitizing dye, the binder, the dye, the matting agent, the support and the like used in the photothermographic image forming material of the present invention will be explained in order. To do.

(Organic Silver Salt) The organic silver salt contained in the photothermographic image forming material of the present invention is a reducible silver source, and contains an organic acid, a heteroorganic acid and an acid containing a reducible silver ion source. A polymer silver salt or the like is used. Also, the ligand is
Organic or inorganic silver salt complexes having a total stability constant for silver ions of 4.0 to 10.0 are also useful. An example of silver salt is
Research Disclosure 17029
And 29963, and salts of organic acids (for example, salts of gallic acid, oxalic acid, behenic acid, stearic acid, palmitic acid, lauric acid, etc.) and the like can be mentioned.

(Developer) The photothermographic image-forming material of the present invention may contain a developer known to those skilled in the art. Typical developers include ascorbic acid and its derivatives, 3-pyrazolidone and its derivatives, 2, 3,
5-trimethylphenol, 2,3,5-triethylphenol, 2,3,5-tri (n) butylphenol,
It is a hindered phenol such as 2,3,5-tri (iso) butylphenol.

(Photosensitive Silver Halide Grains) The photosensitive silver halide according to the present invention can be prepared by any method known in the photographic art, such as a single jet method or a double jet method, for example, an ammonia method emulsion or a neutral method. Can be prepared in advance by any method such as an acid method or an acid method, and then mixed with other components according to the present invention and introduced into the composition used in the present invention. In this case, in order to sufficiently bring the photosensitive silver halide and the organic silver salt into contact with each other, for example, as a protective polymer when preparing the photosensitive silver halide, US Pat.
No. 6,564, No. 3,706,565, No. 3,7
Means using a polymer other than gelatin such as polyvinyl acetals described in 13,833, 3,748,143 and British Patent 1,362,970, and British Patent 1,354. Means for Enzymatic Degradation of Gelatin in Photosensitive Silver Halide Emulsions as described in US Pat. No. 4,076,539.
By preparing the light-sensitive silver halide grains in the presence of a surfactant as described in the specification, various means such as a means for omitting the use of a protective polymer can be applied.

The photosensitive silver halide preferably has a small grain size in order to suppress white turbidity after image formation and obtains a good image quality.
It is 1 μm or less, preferably 0.01 to 0.1 μm, and particularly preferably 0.02 to 0.08 μm. The shape of the silver halide is not particularly limited, and there are cubic and octahedral so-called normal crystals and non-normal crystals such as spherical, rod-shaped and tabular grains. The silver halide composition is also not particularly limited and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide. The amount of silver halide is 50% by mass or less, preferably 25 to 0.1% by mass, more preferably 15 to 0.1% by mass, based on the total amount of silver halide and the organic silver salt described below.

Various conditions such as reaction temperature, reaction time and reaction pressure in the step of converting a part of the organic silver salt into silver halide using the silver halide-forming component can be appropriately set according to the purpose of preparation. it can. Usually, the reaction temperature is 23 ° C to 74 ° C.
C., the reaction time is 0.1 second to 72 hours, and the reaction pressure is preferably set to atmospheric pressure.

The photosensitive silver halide prepared by the above-mentioned various methods is, for example, a sulfur-containing compound, a gold compound,
Platinum compound, palladium compound, silver compound, tin compound,
It can be chemically sensitized with a chromium compound or a combination thereof. The chemical sensitization method and procedure are described in, for example, U.S. Pat. No. 4,036,650, British Patent No. 1,518,850 and the like, and JP-A-51-1850.
No. 22430, No. 51-78319, No. 51-811
No. 24 and other publications. It also achieves sensitization, as described in US Pat. No. 3,980,482, when converting a portion of the organic silver salt to a photosensitive silver halide with a silver halide forming component. Therefore, a low molecular weight amide compound may coexist.

In addition, these photosensitive silver halides are added to groups 6 to 10 of the periodic table of the elements in order to adjust illuminance and gradation.
Group metals such as Rh, Ru, Re, Ir, O
An ion such as s or Fe, or a complex or complex ion thereof can be contained. In particular, it is preferable to contain an ion or a complex ion of a metal belonging to Groups 6 to 10 of the Periodic Table of the Elements. The above metals include W, Fe, Co, Ni, C
u, Ru, Rh, Pd, Re, Os, Ir, Pt, Au
In particular, when used in a photosensitive material for printing plate making, it is preferably selected from Rh, Re, Ru, Ir and Os. These metals can be introduced into the silver halide in the form of a complex.

The content of metal ions or complex ions is generally 1 × 10 ^-9 per mol of silver halide.
^-1 × 10 ^-2 mol is suitable, and preferably 1 × 10 ^-8.
˜1 × 10 ⁻⁴ mol. It is preferable that a compound providing an ion or a complex ion of these metals is added during the formation of silver halide grains and incorporated into the silver halide grains. Preparation of the silver halide grains, that is, nucleation, growth, physical ripening, may be added at any stage before and after chemical sensitization, it is particularly preferable to add at the stage of nucleation, growth, physical ripening, It is preferably added at the stage of nucleation and growth, and most preferably at the stage of nucleation.
Upon addition, it may be added dividedly over several times, or may be uniformly contained in the silver halide grains. Also, JP-A-63-29603 and JP-A-2-306
No. 236, No. 3-167545, No. 4-76534
No. 6,110,146, and No. 5-273683, etc., the particles may have a distribution in the particles. Further, it is possible to give a distribution inside the particles.

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

(Spectral Sensitizing Dye) The spectral sensitizing dye used in the present invention may be, for example, as disclosed in JP-A-63-159841.
No. 60, No. 14034035, No. 63-231437.
No. 63-259651, 63-304242.
Nos. 63-15245, etc., U.S. Pat. No. 4,
639,414, 4,740,455, 4,741,966, 4,751,175, 4,835,096 and the like. A dye can be used. Useful sensitizing dyes used in the present invention are, for example, Research Disclosure I.
tem17643 IV-A (December 1978 p. 2
3), Item 1831X (see p. 4 of August 1978).
37) or the literature cited. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of various scanner light sources can be advantageously selected. For example, JP-A Nos. 9-34078, 9-54409, and 9-
The compound described in 80679 is preferably used.

(Binder) The binder used in the photosensitive layer of the photothermographic image-forming material of the present invention or in the layer adjacent to the non-photosensitive layer is preferably a material which can react with silver halide, an organic silver salt and a developer. A material preferable for a reaction in which a heat-decolorable dye is decolored by heat of 80 to 200 ° C. or lower, or a material in which a base-generating precursor rapidly generates a base by heat is selected. Examples of the binder include alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone and acetone, polymers used by being dissolved in a polar solvent containing dimethyl sulfoxide, dimethylformamide, and the like, and water-dispersed polymers, Any binder may be used as the binder of the photothermographic image-forming material of the present invention.
Further, regarding the composition of the preferable polymer, the glass transition point is preferably −20 ° C. to 80 ° C., and particularly −5 ° C. to 60 ° C.
Is preferred. This is because when the glass transition point is high, the temperature for heat development becomes high, and when the glass transition point is low, fog is likely to occur, resulting in a decrease in sensitivity and a soft tone.

Examples of the polymer to be used by dissolving it in the polar solvent or the like include hydroxyethyl cellulose,
Cellulose derivatives such as carboxymethyl cellulose, methyl cellulose and ethyl cellulose, starch and its derivatives, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl butyral, sodium polyacrylate, polyethylene oxide, acrylic acid amide-acrylic acid ester copolymer, styrene-maleic anhydride. Copolymer, polyacrylamide, sodium alginate,
Gelatin, casein, polystyrene, polyvinyl acetate,
Examples thereof include polyurethane, polyacrylic acid, polyacrylic acid ester, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, vinyl chloride-vinyl acetate copolymer, and styrene-butadiene-acrylic acid copolymer.

Further, after drying and forming a film, the coating film preferably has a low equilibrium water content, and particularly, those having a low equilibrium water content include, for example, cellulose acetate, cellulose acetate butyrate and polymethylmethacrylate. Acrylic esters, polyacrylic acid, polymethacrylic acid, polyvinyl chloride, copoly (styrene-
Maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), polyvinyl acetals (for example, polyvinyl formal, polyvinyl butyral), polyesters, polyurethanes, phenoxy resins, polyvinylidene chloride, epoxy resins,
Examples thereof include polycarbonates, polyvinyl acetate, cellulose esters, and polyamides.

(Dye Used in AI Layer or BC Layer if Necessary) The photothermographic image-forming material of the present invention may optionally comprise an AI layer or BC layer for preventing irradiation or halation of the photothermographic image-forming material. It is provided.
The dye used in the AI layer or the BC layer may be any dye that absorbs imagewise exposure light, and preferably the thermal decolorizable dye described in US Pat. No. 5,384,237 is used. If the dye used is not thermally decolorizable,
The amount used is limited to a range that does not cause image damage to the photothermographic image-forming material, but if it is a heat-decolorable dye, a necessary and sufficient amount of dye can be added.

(Matting Agent) The matting agent may be either an organic substance or an inorganic substance. Examples of the inorganic matting agent include silica described in Swiss Patent No. 330,158 and Swiss Patent No. 330,158. Polystyrene or polymethacrylate described in US Pat.
The polyacrylonitrile described in 079,257 and the polycarbonate described in US Pat. No. 3,022,169 can be used.

The shape of the matting agent may be either a fixed shape or an amorphous shape, but a fixed shape is preferable, and a spherical shape is preferably used. The size of the matting agent is represented by the diameter when the volume of the matting agent is converted into a spherical shape. In the present invention, the particle size of the matting agent refers to the spherically converted diameter.
The matting agent used in the present invention has an average particle size of 0.5 to 1
It is preferably 0 μm, more preferably 1.0
Is about 8.0 μm. The monodispersity of the particles is preferably 50 or less, more preferably 40 or less, and particularly preferably 20 or less. Here, the monodispersity of the particles is calculated by dividing the standard deviation of the particle diameters by the average value of the particle diameters.
It is represented by a number multiplied by zero. The method of adding the matting agent according to the present invention may be a method of previously dispersing and coating in the coating solution, or a method of spraying the matting agent after coating the coating solution and before completion of drying. May be.

(Support) As the support, paper, synthetic paper,
A support such as a non-woven fabric, a metal foil or a plastic film can be used, and a composite sheet in which these are combined may be optionally used.

<Image exposure> As an exposure method, there is disclosed in Japanese Patent Laid-Open No.
No. 304869, No. 9-311403 and JP 20
Laser exposure can be performed by the method described in each publication of 00-10230.

<Heat Developing Device> The device for developing the photothermographic image forming material is disclosed in JP-A-11-65067 and 11-7.
The apparatus described in each publication of 2897 and 11-84619 can be used.

[0085]

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

Example 1 <Preparation of Subbed Substrate> A polyethylene terephthalate support having a thickness of 175 μm was subjected to corona discharge treatment at 8 W / m ² · min for both surfaces, and one surface thereof was coated with the subbing coating solution a- 1 was applied so as to have a dry film thickness of 0.8 μm and dried to form an undercoat layer A-1. Also, on the opposite surface,
-1 was applied to a dry film thickness of 0.8 μm and dried to form an undercoat layer B-1.

[0087]   << Subbing coating solution a-1 >>   Butyl acrylate (30% by mass), t-butyl acrylate (20% by mass) , Styrene (25% by weight), 2-hydroxyethyl acrylate (25% by weight) 270g of copolymer latex liquid (solid content 30%)   Hexamethylene-1,6-bis (ethylene urea) 0.8 g   Make up to 1L with water.

[0088]   <Subbing coating solution b-1>   Butyl acrylate (40% by mass), styrene (20% by mass), glycidyl Acrylate (40% by mass), copolymer latex liquid (solid content 30%)                                                                 270 g   Hexamethylene-1,6-bis (ethylene urea) 0.8 g   Make up to 1L with water.

Subsequently, the undercoat layer A-1 and the undercoat layer B-1
8 W / m ² · min of corona discharge is applied to the upper surface of the undercoat layer, and the undercoating upper layer coating solution a-2 is applied and dried on the undercoating layer A-1 to a dry film thickness of 0.1 μm. Then, the undercoat upper layer A-2 was provided. An undercoating upper layer B-2 having an antistatic function was provided on the undercoating layer B-1 by coating and drying the following undercoating upper layer coating solution b-2 to a dry film thickness of 0.8 μm. .

<< Undercoating Upper Layer Coating Liquid a-2 >> Gelatin 0.4 g / m ² Mass Mass Silica Particles (Average Particle Size 3 μm) 0.1 g Finish with Water to 1 L << Undercoating Upper Layer Coating Liquid b-2 >> Styrene -Butadiene copolymer latex liquid (solid content 20%) 80 g Polyethylene glycol (mass average molecular weight 600) 6 g Water is used to make 1 L.

<Preparation of silver halide grain emulsion A> Water 90
After 7.5 g of inert gelatin and 10 mg of potassium bromide were dissolved in 0 ml to adjust the temperature to 28 ° C. and pH to 3.0, 370 ml of an aqueous solution containing 74 g of silver nitrate (98 /
An aqueous solution containing potassium bromide and potassium iodide in the molar ratio of 2) was added over 10 minutes by the controlled double jet method while keeping pAg at 7.7. Synchronize with the addition of silver nitrate to add 1 × hexachloroiridium sodium salt.
10 ⁻⁶ mol / silver 1 mol was added. Thereafter, 0.3 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, and the pH was adjusted to 5 with a sodium hydroxide solution to obtain an average particle size of 0.036 μm and a projected diameter area. Cubic silver iodobromide grains having a coefficient of variation of 8% and a [100] plane ratio of 87% were obtained. This emulsion was subjected to coagulation sedimentation using a gelatin coagulant and desalted, and 0.1 g of phenoxyethanol was added to adjust the pH to 5.9 and pAg to 7.5 to obtain a silver halide grain emulsion A.

<Preparation of Organic Silver Salt> 111.4 g of behenic acid, 83.8 g of arachidic acid and 54.9 g of stearic acid were dissolved in 4720 ml of pure water at 80 ° C. Next, while stirring at high speed, a 1.5 molar sodium hydroxide aqueous solution 54
After adding 0.2 ml and 6.9 ml of concentrated nitric acid,
Cooled to 0 ° C. to give a sodium acidate solution. While maintaining the temperature of the above-mentioned sodium salt of an organic acid at 55 ° C., 420 ml of pure water was added to the silver halide grain emulsion A (containing 0.038 mol of silver) and stirred for 5 minutes. Next, 760.6 ml of a 1 mol silver nitrate solution was added over 2 minutes, the mixture was stirred for 20 minutes, and water-soluble salts were removed by filtration. Thereafter, washing with deionized water and filtration were repeated until the electric conductivity of the filtrate became 2 μS / cm, and the filtered substance was dried.

<Coating of Photosensitive Layer and BC Layer> Samples were prepared by sequentially forming the following layers on the undercoating upper layer B-2. In addition, each drying was performed at 45 ° C. for 1 minute.

<< Coating on BC layer >> On the back surface side, a coating solution prepared by further adding water to an aqueous solution or dispersion of the following thermobleachable dye composition is coated and dried to the following coating amounts. Then, a BC layer was formed.

<< BC Layer Coating >> Inert gelatin 1.8 g / m ² Dye: C1 1.2 × 10 ⁻⁵ mol / m ² Activator: N-propyloctylsulfonamidoacetic acid 0.02 g / m ² Dihexylsulfosuccinic acid Sodium salt 0.02 g / m ² Hardener: 1,2-bis (vinylsulfonamide) ethane 0.02 g / m ² << Application of BC protective layer >> Inert gelatin 1.1 g / m ² Hardener: 1, 2-bis (vinylsulfonamide) ethane 0.01 g / m ² Activator: N-propylperfluorooctylsulfonamide acetic acid 0.02 g / m ² Matting agent (PMMA: average particle size 5 μm) 0.12 g / m ² << Coating of photosensitive layer side << Coating of AI layer >> Binder: PVB-1 0.4 g / m ² Dye: C1 1.2 × 10 ^-5 mol / m ^{2 To} form a photosensitive layer, the following composition was added to methyl ethyl ketone. solvent A coating solution dissolved in was prepared. Apply this coating solution at 35 ℃
It was kept in the vicinity and coated and dried on the undercoat layer A-2 of the support so that the following coating amount was obtained.

Organic silver salt (including silver halide) Silver amount 1.36 g / m ² Binder: PVB-1 2.6 g / m ² Maleimide compound: described in Table 1 3.2 × 10 ⁻⁴ equivalent / m ² spectral sensitizing dyes: A1 2.0 × 10 ^-5 mol / m ² antifoggant -1: pyridinium hydrobromide perbromide 0.3 mg / m ² antifoggant -2: isothiazolone 1.2 mg / m ² developer: 2,3,5-trimethylphenol 3.3 × 10 ⁻³ mol / m ²

[0097]

[Chemical 15]

<< Surface Protective Layer >> A coating solution prepared by adding the following composition was coated and dried on the photosensitive layer so as to have the following coating amounts to form a surface protective layer.

Cellulose acetate butyrate 1.2 g / m ² 4-methylphthalic acid 0.7 g / m ² tetrachlorophthalic acid 0.2 g / m ² tetrachlorophthalic anhydride 0.5 g / m ² silica matting agent (average Particle size 5 μm) 0.5 g / m ² <Evaluation of photographic performance> The above-prepared sample was divided into two and one was stored at 25 ° C. in an atmosphere of 60% RH for 3 days, and then exposed to a semiconductor laser of 810 nm. The sample was exposed to light with a sensitometer of No. 2 and heated at 120 ° C. for 8 seconds, and the obtained sample was used as a normal humidity sample. The other one was stored in a high humidity atmosphere of 35 ° C. and 78% RH for 3 days, and then similarly exposed and developed to obtain a high humidity sample. Laser exposure and development of the above normal humidity sample were performed at 25 ° C. ± 1 ° C. and relative humidity of 54%.
It was performed in a room where the humidity was adjusted to ± 1%.

The sensitivity and fog of the normal humidity sample and the high humidity sample were measured with a densitometer. Sensitivity is 0 from fog density.
3 Defined as the reciprocal of the ratio of the exposure dose that gives a high density, Sample 1
The storage stability was represented by the relative sensitivity with 01 as the reference (100), and the storage stability was represented by the difference in fog and the difference in sensitivity between the normal humidity sample and the high humidity sample. The smaller the increase in fog and the decrease in sensitivity, the better the storage stability.

[0101]

[Table 1]

From Table 1, it can be seen that the photothermographic image-forming material containing the maleimide compound of the first invention is excellent in photographic performance (sensitivity and fog characteristics) and storability during heat development. However, it can be seen that the photothermographic image-forming material containing no maleimide compound according to the present invention is inferior in photographic performance and storability during thermal development.

Example 2 A sample was prepared in the same manner as in Example 1 and its performance was evaluated. Here, the phthalazine compound was additionally added to the AI layer and the photosensitive layer in the following amounts to evaluate fog, sensitivity and storability.

AI layer: 1.2 × 10 ⁻⁵ mol / m ² Photosensitive layer: 2.1 × 10 ⁻⁴ mol / m ²

[0105]

[Table 2]

From Table 2, it can be seen that the photothermographic image-forming material containing the maleimide compound and the phthalazine compound according to the second aspect of the invention is more sensitive than the first aspect of the invention, that is, the photographic performance at the time of heat development, that is, sensitivity and fog. It can be seen that the characteristics and storage stability are further improved.

Example 3 A sample was prepared in the same manner as in Example 1, except that a polyhalomethane compound (3.6 × 10 ⁻⁴ mol / silver 1 mol) and a phthalazine compound (2.6 × 10 ⁻⁴ mol / silver) were used. 1 mol), a bisphenol compound (3.8 × 10 ⁻⁴ mol / silver 1 mol),
A crosslinking agent (2.6 × 10 ⁻⁴ mol / m ² ) was added to the photosensitive layer. The photographic performance and storability were evaluated in the same manner as in Example 1.
Further, the fog test by the baked-out silver was carried out by illuminating the obtained developed sample with a fluorescent lamp of 1,000 lux. A diffusion sheet was interposed between the fluorescent lamp and the test sample so that the light irradiation was uniform. Although the irradiation time was changed, the fog value (referred to as "printed-out silver fog") after irradiation for 3 hours is shown in Table 3 here. As for the residual color, the tint of blackened silver was visually evaluated. A rating of 5 to 1 is used, the darker the black tint is, the better the yellow is. Rank 5
Is the best level, rank 1 is the worst level, and rank 3 is the level that has no practical problems.

[0108]

[Table 3]

From Table 3, the photothermographic image-forming material containing the maleimide compound and at least one selected from the phthalazine compound, the polyhalomethane compound and the bisphenol compound, which is the third invention, and the crosslinking agent is the second It can be seen that, compared with the present invention, the fog due to the printed silver during storage (printed silver fog) and the residual color after development are further improved.

[0110]

According to the present invention, high sensitivity and low fog are imparted, fog due to burned-out silver after development is suppressed, and further the raw storage stability before development and the image storage stability after development are excellent. It was possible to provide a photothermographic image-forming material with little residual color and stable color tone.

Claims (4)

[Claims] 1. A photothermographic image-forming material having a photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a developer and a binder on a support, wherein the photothermographic material contains a maleimide compound. Photographic material. 2. A photothermographic image-forming material having a photosensitive layer containing a photosensitive silver halide grain, an organic silver salt, a developer and a binder on a support, which further contains a maleimide compound, and further comprises the photosensitive layer or A photothermographic image-forming material comprising a layer adjacent to the photosensitive layer containing at least one selected from a phthalazine compound, a polyhalomethane compound and a bisphenol compound. 3. A photothermographic image forming material having a photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a developer and a binder on a support, which further contains a maleimide compound, and further comprises the photosensitive layer or The layer adjacent to the photosensitive layer contains a phthalazine compound, and the binder forming the photosensitive layer or the adjacent layer is crosslinked with a crosslinking agent, and the crosslinking agent is an isocyanate compound or vinyl. A photothermographic image-forming material comprising at least one crosslinking agent selected from a sulfone compound and an epoxy compound. 4. The maleimide compound has the following general formula (M
1) or a compound represented by (M2)
The photothermographic image according to any one of claims 1 to 3.
Imaging material. [Chemical 1] (In the general formula (M1), X₁And Y are single
Bond, alkylene group or alkylenecarbonyl
A xy group (where the alkylene moiety is bonded to the nitrogen atom of the maleimide ring)
Represent). This alkylene group and alkylene carb
The bonyloxy group may have a substituent. L is (m +
n) represents a valent linking group. m and n are 1 to 5 integers, respectively
It represents a number (however, 2 ≦ m + n ≦ 6). General formula (M2)
At X ₂Is X₁Is synonymous with. R is a monovalent organic group
Represent )