JPH11194445A - Heat-developable photosensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-developable photosensitive material superior in long-time storage after development and improved in film adhesion after development. SOLUTION: This heat-developable photosensitive material is provided on at least one side of a support body with at least each one of a photosensitive layer containing silver halide grains and a nonphotosensitive layer adjacent to the photosensitive layer and far from the support body, the total thickness of the both layers is 5-14 μm and the silver amount is 0.3-1.6 g/m<2> .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photothermographic material, and more particularly, to a photothermographic material having excellent image storability after development and without deterioration in film strength after development. .

[0002]

2. Description of the Related Art Conventionally, in the field of printing plate making and medical treatment, waste liquid caused by wet processing of an image forming material has been a problem in terms of workability. It is strongly desired to reduce the amount of waste liquid.

[0003] Therefore, there is a need for a technique relating to photothermographic materials for photographic technology, which enables efficient exposure with a laser imagesetter or laser imager and can form a high-resolution, clear black image. I have.

[0004] Such techniques include, for example, US Patent Nos. 3,152,904 and 3,487,075 and D.C. Morgan (Dry Silver Photograph)
hic Materials) ”(Handbook)
of Imaging Materials, Mar
cel Dekker, Inc. 48, 1991)
And the like, a photothermographic material containing an organic silver salt, photosensitive silver halide grains and a reducing agent on a support is known.

[0005]

Incidentally, these photothermographic materials are characterized in that an image is usually formed by heat development at 80 to 250 ° C., and fixing is not performed. Therefore, the silver halide and the organic silver salt remaining in the unexposed area remain in the photosensitive material without being removed. However, when these remaining silver halides and organic silver salts are stored for a long period of time, the fog density of the unexposed portions increases, or the color tone of the developed silver changes to a warm black tone. That was the problem.

Further, since the binder is softened by heat immediately after thermal development, the film is easily peeled off even with a nail or the like, which may have a great adverse effect on the image quality.

Therefore, the present invention has been made in view of the above circumstances, and an object of the present invention is to provide a photothermographic material which has excellent long-term storage properties after development and has improved film formation after development. To provide.

[0008]

A photothermographic material according to the present invention for solving the above-mentioned problems is provided on at least one side of a support, a photosensitive layer containing photosensitive silver halide grains,
In a photothermographic material having at least one non-photosensitive layer adjacent to the photosensitive layer and remote from the support, the total thickness of the photosensitive layer and the non-photosensitive layer is 5 to 14
μm, and the amount of silver is 0.3 to 1.6 g / m ² .

In a preferred embodiment of the present invention, the photosensitive layer contains at least an organic silver salt and a reducing agent; the photosensitive layer and / or the non-photosensitive layer contains an inorganic matting agent; Infrared sensitization for external laser exposure.

[0010]

Embodiments of the present invention will be described below in detail.

The photothermographic material of the present invention is provided on a support.
At least two or more layers are formed. At least one of the layers is constituted by a photosensitive layer containing a photosensitive silver halide, and at least one layer located adjacent to the photosensitive layer and remote from the support is constituted by a non-light-sensitive layer. .

The non-photosensitive layer as used herein refers to a layer substantially free of photosensitive silver halide.

Here, "substantially not containing" means that the silver content of silver halide is 0.05 g or less per 1 m ^2, and may contain a non-photosensitive organic silver salt or the like.

The photothermographic material of the present invention is preferably a so-called one-sided photosensitive material having at least one backing layer on the side of the support opposite to the side containing the photosensitive layer.

The silver halide grains according to the present invention function as an optical sensor. In the present invention, in order to suppress white turbidity after image formation, and to obtain good image quality, the average particle size is preferably small, specifically, the average particle size is preferably 0.1 μm or less, more preferably 0.01 μm to 0.1 μm, particularly 0.02 μm to 0.0
8 μm is preferred.

When the silver halide grains are cubic or octahedral so-called normal crystals, the average grain size means the length of the ridges of the silver halide grains. In the case of non-normal crystals, for example, in the case of spherical, rod-shaped or tabular grains, it refers to the diameter of a sphere equivalent to the volume of silver halide grains.

The silver halide grains are preferably monodisperse grains. The monodisperse particles referred to herein are particles having a degree of monodispersity of 40% or less, more preferably 30% or less, particularly preferably 0.1% or more and 20% or less.
% Or less.

Monodispersity = (standard deviation of particle size) / (average value of particle size) × 100 In the present invention, the silver halide particles have an average particle size of 0.1.
μm or less and more preferably monodisperse particles,
By setting it in this range, the granularity of the image is also improved.

The shape of the silver halide grains is not particularly limited, but the proportion occupied by the Miller index [100] plane is preferably high, and this proportion is 50% or more, and more preferably 7%.
It is preferably at least 0%, particularly preferably at least 80%. The ratio of the [100] plane of the Miller index is determined by the T.V. method using the dependence of the adsorption of the sensitizing dye on the [111] plane and the [100] plane. Tani, J .; Imaging Sci. , 29,
165 (1985).

The average particle diameter of the monodisperse particles is 0.1 μm.
The following is preferable, and more preferably 0.01 μm to 0.1
μm, particularly preferably 0.02 μm to 0.08 μm.

Another preferred form of silver halide grains is tabular grains. Here, the tabular grains are:
The aspect ratio (= r / h) is 3 or more when the square root of the projected area of the particle is r μm and the thickness in the vertical direction is h μm. Among them, those having an aspect ratio of 3 or more and 50 or less are preferable.

The average particle diameter of the tabular grains is preferably 0.1 μm or less, and more preferably 0.01 μm to 0.08 μm.
μm is more preferred. These are disclosed in U.S. Pat.
No. 337, 5,314,798, 5,320,9
No. 58 and the like, and the desired tabular grains can be easily obtained. In the present invention, when these tabular grains are used, the sharpness of an image is further improved.

The composition of the silver halide is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide and silver iodide. The photographic emulsion used in the present invention is P.I. Chimie et by Glafkids
Physique Photographique (P
aul Montel, 1967); F. D
Photographic Emuls by uffin
ion Chemistry (The Focal P
Res., 1966); L. Zelikman
Making and Coating by et al
Photographic Emulsion (Th
e Focal Press, 1964) and the like.

That is, any of an acidic method, a neutral method, an ammonia method and the like may be used. In order to form a solution by reacting a soluble silver salt and a soluble halide, a one-side mixing method, a double-mixing method, a combination thereof and the like are used. Either may be used.

The silver halide may be added to the image forming layer by any method, and the silver halide is arranged so as to be close to the reducible silver source.

The silver halide may be prepared by converting part or all of the silver in the organic silver salt to silver halide by reacting the organic silver salt with a halogen ion,
Silver halide may be prepared in advance and added to a solution for preparing an organic silver salt, or a combination of these methods is possible, but the latter is preferred.

Generally, the silver halide is preferably contained in an amount of 0.75 to 30% by weight based on the organic silver salt.

The silver halide used in the present invention is selected from VIB, VIIB and VII belonging to transition metals of the Periodic Table of the Elements.
It preferably contains an ion or a complex ion of a metal belonging to Group I or IB. The above metals include Cr, W
(The above-mentioned VIB group): Re (VIIB group): Fe, Co,
Ni, Ru, Rh, Pd, Os, Ir, Pt (VI
II): Cu and Au (above IB) are preferable, and when used for a photosensitive material for plate making, Rh, Re, and
It is preferable to be selected from Ru, Ir, and Os.

These metals can be introduced into the silver halide in the form of a complex. In the present invention, the transition metal complex is preferably a six-coordinate complex represented by the following general formula.

In the formula [ML ₆ ] ^m , M is a group of elements of the periodic table VIB, VIIB, VIII
A transition metal selected from Group IV and IB elements, L represents a bridging ligand, and m represents 0, -1, -2 or -3.

Specific examples of the ligand represented by L include halides (fluoride, chloride, bromide and iodide), cyanide, cyanate, thiocyanate, selenocyanate, tellurocyanate, azide and alcohol. Each ligand of
Nitrosyl, thionitrosyl and the like can be mentioned, and preferred are aquo, nitrosyl and thionitrosyl. If an aquo ligand is present, it preferably occupies one or two of the ligands. L may be the same or different.

Particularly preferred examples of M are rhodium (Rh), ruthenium (Ru), rhenium (Re) or osmium (Os).

Specific examples of the transition metal coordination complex are shown below. ^{_{1: [RhCl 6] 3- 2}} : [RuCl 6] 3- 3: [ReCl 6] 3- 4: [RuBr 6] 3- 5: [OsCl 6] 3- 6: [CrCl 6] 4- 7: _{[Ru (NO) Cl 5]} 2- 8: [RuBr 4 (H 2 O)] 2- 9: [Ru (NO) (H 2 O) Cl 4] - 10: [RhCl 5 (H 2 O)] ^{2- 11: [Re (NO)} Cl 5] 2- 12: [Re (NO) CN 5] 2- 13: [Re (NO) ClCN 4] 2- 14: [Rh (NO) 2 Cl 4] - 15: [Rh (NO) ( H 2 O) Cl 4] - 16: [Ru (NO) CN 5] 2- 17: [Fe (CN) 6] 3- 18: [Rh (NS) Cl 5] 2 ^{- 19: [Os (NO)} Cl 5] 2- 20: [Cr (NO) Cl 5] 2- 21: [Re (NO) Cl 5] - 22: [Os (NS) Cl 4 (TeCN)] 2 ^{- 23: [Ru (NS)} C ^{_{5] 2- 24: [Re (}} NS) Cl 4 (SeCN)] 2- 25: [Os (NS) Cl (SCN) 4] 2- 26: [Ir (NO) Cl 5] 2-

One of these metal ions or complex ions may be used, or two or more of the same or different metals may be used in combination.

The content of these metal ions or complex ions is generally in the range of 1 to 1 mol per mol of silver halide.
The amount is suitably from ^10-9 to ^1-10-2 mol, preferably 1 mol.
X 10 ^-8 to 1 X 10 ^-4 mol.

The compound providing these metal ions or complex ions is preferably added during silver halide grain formation and incorporated into the silver halide grains. Preparation of silver halide grains, that is, nucleation and growth , Physical aging,
Although it may be added at any stage before and after chemical sensitization, it is particularly preferable to add at the stage of nucleation, growth, and physical ripening,
Further, it is preferably added at the stage of nucleation and growth, most preferably at the stage of nucleation.

In addition, the compound may be added in several divided portions, may be added uniformly in the silver halide grains, or may be added to silver halide grains.
-306236, 3-167545, 4-76
No. 534, No. 6-110146, No. 5-273683
As described in Japanese Patent Application Laid-Open No. H10-284, etc., the particles can be contained in the particles with a distribution. Preferably, a distribution can be provided inside the particles.

These metal compounds can be added by dissolving them in water or a suitable organic solvent (eg, alcohols, ethers, glycols, ketones, esters, amides). A method in which an aqueous solution of a powder or an aqueous solution in which a metal compound and NaCl and KCl are dissolved together is added to a water-soluble silver salt solution or a water-soluble halide solution during particle formation and placed, or a silver salt solution and a halide solution are used. When mixed simultaneously, a third aqueous solution is added to prepare silver halide grains by a three-liquid simultaneous mixing method, a method in which a required amount of an aqueous solution of a metal compound is charged into a reaction vessel during grain formation, or halogen is added. There is a method in which another silver halide grain doped with a metal ion or a complex ion in advance at the time of preparing silver halide is added and dissolved. 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 and KCl are dissolved together is added to a water-soluble halide solution. When adding to the particle surface, a required amount of an aqueous solution of a metal compound can be charged into the reaction vessel immediately after the formation of the particles, during or at the end of physical ripening, or at the time of chemical ripening.

A sensitizing dye can be used in the photothermographic material of the present invention. When the sensitizing dye is adsorbed on silver halide grains, the silver halide grains are spectrally sensitized in a desired wavelength region. Anything that can be used may be used.

As the sensitizing dye, a cyanine dye, a merocyanine dye, a complex cyanine dye, a complex merocyanine dye, a holo-holer cyanine dye, a styryl dye, a hemicyanine dye, an oxonol dye, a hemioxonol dye, and the like can be used.

Useful sensitizing dyes for use in the present invention include, for example, Research Disclosure Item
m17643 IV-A (p.2 December 1978)
3), Item 1831X (p.4, August 1979)
37) or in the literature cited. In particular, a sensitizing dye having a spectral sensitivity suitable for the spectral characteristics of the light source of various laser imagers, laser imagesetters and plate making cameras can be advantageously selected.

As an example of spectral sensitization of red light, He-N
For the e-laser light source, compounds of I-1 to I-38 described in JP-A-54-18726,
Compounds I-1 to I-35 described in JP-A-322 and compounds I-1 to I-34 described in JP-A-7-287338, and for the LED light source, Japanese Patent Publication No. 55-39818.
Dyes 1 to 20 described in JP-A-62-284343
And compounds of I-1 to I-37 described in
The compounds of I-1 to I-34 described in -287338 are advantageously selected.

To spectrally sensitize silver halide grains in any wavelength range of 750 to 1400 nm, specifically, a photosensitive silver halide is prepared by adding cyanine, merocyanine, styryl, hemicyanine, oxonol, A variety of known dyes, including oxonol and xanthene dyes, can be used to spectrally sensitize advantageously.

Useful cyanine dyes are, for example, cyanine dyes having a basic nucleus such as a thiazoline nucleus, an oxazoline nucleus, a pyrroline nucleus, a pyridine nucleus, an oxazole nucleus, a thiazole nucleus, a selenazole nucleus and an imidazole nucleus.

Preferred useful merocyanine dyes are, in addition to the above basic nuclei, thiohydantoin nuclei, rhodanine nuclei, oxazolidinedione nuclei, thiazolinedione nuclei, barbituric acid nuclei, thiazolinone nuclei, malononitrile nuclei and pyrazolone nuclei. Including acid nuclei.

Among the above-mentioned cyanine and merocyanine dyes, those having an imino group or a carboxyl group are particularly effective. For example, U.S. Pat.
Nos. 3,719,495, 3,877,943, British Patent Nos. 1,466,201, 1,469,117, 1,422,057, JP-B-3-103391, JP-B-6-52387, JP-A-5-341432, It may be appropriately selected from known dyes as described in JP-A-6-194787 and JP-A-6-301141. A particularly preferred structure of the dye is a cyanine dye having a thioether bond.
239, JP-A-3-13838, 3-138462,
4-255840, 5-72659, 5-72661,
6-222491, 2-230506, 6-25875
7, 6-317868, 6-324425, Tokiohei 7-
500926.

These sensitizing dyes may be used alone,
Two or more kinds may be used in combination. The combination of sensitizing dyes
In particular, it is often used for supersensitization.

In addition to the sensitizing dye, the emulsion may contain a dye which does not itself have a spectral sensitizing effect or a substance which does not substantially absorb visible light and exhibits supersensitization. Useful sensitizing dyes, combinations of dyes exhibiting supersensitization, and substances exhibiting supersensitization are Research Disclo.
Sure 176, 17643 (issued in December 1978), page 23, IV, J, or JP-B-49-255.
And JP-A-43-4933, JP-A-59-19032, and JP-A-59-192242.

The sensitizing dyes used in the present invention may be used in combination of two or more. The sensitizing dyes can be added to the silver halide emulsion by dispersing them directly in the emulsion or by adding water, methanol, ethanol, propanol, acetone, methylcellosolve, 2,2,3,3 -Tetrafluoropropanol, 2,2,2-trifluoroethanol, 3-methoxy-1-propanol, 3-methoxy-1-butanol, 1-methoxy-2-propanol, 3-methoxy-1-butanol, 1-methoxy −
A solvent such as 2-propanol or N, N-dimethylformamide may be added to the emulsion alone or in a mixed solvent.

Further, as disclosed in US Pat. No. 3,469,987, etc., a dye is dissolved in a volatile organic solvent, and the solution is dispersed in water or a hydrophilic colloid.
A method of adding this dispersion to an emulsion, JP-B-44-23
No. 389, No. 44-27555, No. 57-22091
A method in which a dye is dissolved in an acid and the solution is added to the emulsion, or a solution is added to the emulsion as an aqueous solution in the presence of an acid or a base, as disclosed in U.S. Pat.
No. 135, No. 4006025, etc., a method of adding an aqueous solution or a colloidal dispersion in the presence of a surfactant to an emulsion as disclosed in JP-A Nos. 53-102733 and 58; A method of directly dispersing a dye in a hydrophilic colloid and adding the dispersion to an emulsion as disclosed in JP-A-105141.
As disclosed in Japanese Patent No. 74624, a method of dissolving a dye using a compound that causes red shift and adding the solution to an emulsion can also be used. Also, ultrasonic waves can be used for the solution.

The sensitizing dye used in the present invention may be added to the silver halide emulsion at any stage of the emulsion preparation which has been found to be useful.
For example, US Patent Nos. 2,735,766 and 362,896
No. 0, No. 4183756, No. 4222566,
As disclosed in the specifications of JP-A-58-184142 and JP-A-60-196747, the timing before silver halide grain formation and / or desalting, during and / or during desalting. After the period before the start of chemical ripening,
As disclosed in the specification of JP-A-58-113920 and the like, at any time during the process immediately before or during chemical ripening, or after chemical ripening and before coating, before the emulsion is coated. May be added. Further, as disclosed in the specification of U.S. Pat. No. 4,225,666, JP-A-58-7629, etc., the same compound is used alone.
Or, in combination with a compound having a heterogeneous structure, for example, it is divided and added during the particle forming step and during the chemical ripening step or after the completion of the chemical ripening, or divided before or during the chemical ripening and after the completion. Alternatively, the compound to be divided and added and the type of combination of compounds may be changed and added.

In the present invention, the organic silver salt is a reducible silver source, and a silver salt of an organic acid or a heteroorganic acid containing a reducible silver ion source, especially a long chain (10 to 3 carbon atoms).
An aliphatic carboxylic acid having 0, preferably 15 to 25 carbon atoms, and a nitrogen-containing heterocyclic ring are preferred.

Organic or inorganic silver salt complexes wherein the ligand has a total stability constant for silver ions of 4.0 to 10.0 are also useful.

An example of a suitable silver salt is Research D
No. 17029 and 29996, and include: salts of organic acids, such as salts of gallic acid, oxalic acid, behenic acid, stearic acid, palmitic acid, lauric acid, etc .; silver carboxyalkylthio Urea salts (eg, 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea, etc.); silver of a polymer reaction product of an aldehyde and a hydroxy-substituted aromatic carboxylic acid Complexes (e.g., aldehydes (formaldehyde, acetaldehyde, butyraldehyde, etc.), hydroxy-substituted acids (e.g., salicylic acid, benzoic acid, 3,5-dihydroxybenzoic acid, 5,5-thiodisalicylic acid), silver salts of thioenes or Complex (for example, 3- (2-carboxyethyl) -4
-Hydroxymethyl-4- (thiazoline-2-thioene and 3-carboxymethyl-4-thiazoline-2-
Thioene), imidazole, pyrazole, urazole,
1,2,4-thiazole and 1H-tetrazole, 3-
Complexes or salts of silver and a nitrogen acid selected from amino-5-benzylthio-1,2,4-triazole and benzotriazole; silver salts such as saccharin and 5-chlorosalicylaldoxime; and silver salts of mercaptides.

In the present invention, a particularly preferred silver source is silver behenate.

The organic silver salt compound can be obtained by mixing a water-soluble silver compound and a compound which forms a complex with silver, and can be obtained by a forward mixing method, a reverse mixing method, a simultaneous mixing method, and a method described in JP-A-9-12764.
A controlled double jet method as described in No. 3 is preferably used.

In the present invention, the organic silver salt preferably has an average particle size of 1 μm or less and is monodispersed. The average particle size of the organic silver salt means that the particles of the organic silver salt are, for example, spherical,
In the case of rod-shaped or tabular grains, it refers to the diameter of a sphere equivalent to the volume of the organic silver salt grains. The average particle size is preferably 0.01 μm to 0.8 μm, particularly 0.05 μm.
m to 0.5 μm is preferred. Monodispersion has the same meaning as in the case of silver halide grains, and the preferred degree of monodispersion is 1 to 5.
30. In the present invention, the organic silver salt has an average particle size of 1
It is more preferable that the particles are monodisperse particles having a particle size of not more than μm.

The photothermographic material of the present invention preferably contains a reducing agent. Examples of suitable reducing agents are described in U.S. Patent Nos. 3,770,448, 3,773,512,
No. 3,593,863 and Research D
No. 17029 and 29996, and include the following:

Aminohydroxycycloalkenones (eg, 2-hydroxypiperidino-2-cyclohexenone); aminoreductones esters (eg, piperidinohexose reductone monoacetate) as precursors of reducing agents An N-hydroxyurea derivative (for example, Np-methylphenyl-N
Hydrazones of aldehydes or ketones (e.g. anthracene aldehyde phenylhydrazone); phosphoramidophenols; phosphoramidoanilines; polyhydroxybenzenes (e.g.
Hydroquinone, t-butyl-hydroquinone, isopropylhydroquinone and (2,5-dihydroxy-phenyl) methylsulfone); sulfhydroxamic acids (eg, benzenesulfhydroxamic acid); sulfonamidoanilines (eg, 4- (N- Methanesulfonamido) aniline); 2-tetrazolylthiohydroquinones (eg, 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone); tetrahydroquinoxalines (eg, 1,2,3,4-tetrahydro) Aminooxins; Azines (eg, a combination of an aliphatic carboxylic acid arylhydrazide and ascorbic acid); a combination of polyhydroxybenzene and hydroxylamine, reductone and / or hydrazine; Hydroxanoic acids Combinations of azines and sulfonamidophenols; α-cyanophenylacetic acid derivatives; combinations of bis-β-naphthol and 1,3-dihydroxybenzene derivatives; 5-pyrazolones; sulfonamidophenol reducing agents; 2-phenylindane-1 ,
3-dione and the like; 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,
4,5-ethylidene-bis (2-t-butyl-6-methyl) phenol), ultraviolet-sensitive ascorbic acid derivatives and 3-pyrazolidones.

Particularly preferred reducing agents are hindered phenols.

The hindered phenols include compounds represented by the following general formula (A).

[0062]

Embedded image

In the formula, R is a hydrogen atom or a group having 1 to 1 carbon atoms.
10 alkyl group (e.g., -C ₄ H _9, 2,4,4-
R ′ and R ″ represent an alkyl group having 1 to 5 carbon atoms (eg, methyl, ethyl, t-
Butyl).

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

[0065]

Embedded image

[0066]

Embedded image

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

Binders suitable for the photothermographic material of the present invention are transparent or translucent, generally colorless, and include natural polymer synthetic resins, polymers and copolymers, and other film-forming media such as gelatin, gum arabic,
Poly (vinyl alcohol), hydroxyethyl cellulose, cellulose acetate, cellulose acetate butyrate, poly (vinyl pyrrolidone), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid) ), Copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (ester) ), Poly (urethane), phenoxy resin, poly (vinylidene chloride), poly (epoxide),
Poly (carbonate) s, poly (vinyl acetate),
There are cellulose esters and poly (amides). These may be hydrophilic or non-hydrophilic.

In the present invention, the amount of the binder in the photosensitive layer is preferably 1.5 to 10 for the purpose of preventing dimensional fluctuation after thermal development.
g / m ² , more preferably 1.
It is 7 to 8 g / m ² . If it is less than 1.5 g / m ² , the density of the unexposed portion will increase significantly and may not be usable.

In the present invention, a matting agent is preferably contained on the photosensitive layer side, and in order to prevent the image after thermal development from being damaged, it is preferable to provide a matting agent on the surface of the photosensitive material. The matting agent is preferably contained in a weight ratio of 0.5 to 10% with respect to all binders on the emulsion layer side.

The material of the matting agent used in the present invention may be either an organic substance or an inorganic substance. For example, as inorganic substances, silica described in Swiss Patent No. 330,158, glass powder described in French Patent No. 1,296,995, etc., and alkali described in British Patent No. 1,173,181 etc. An earth metal or a carbonate such as cadmium or zinc can be used as a matting agent.

As organic substances, US Pat. No. 2,322,
037 etc., Belgian Patent No. 625, 45
No. 1 and British Patent Nos. 981, 198, etc., polyvinyl alcohol described in JP-B-44-3643, etc., polystyrene or polymethacrylate described in Swiss Patent No. 330,158, U.S. Pat. Organic matting agents such as polyacrylonitrile described in 3,079,257 and the like and polycarbonate described in U.S. Pat. No. 3,022,169 can be used.

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

The size of the matting agent is represented by a diameter when the volume of the matting agent is converted into a spherical shape. In the present invention, the particle diameter of the matting agent indicates the diameter converted into a sphere. The matting agent used in the present invention preferably has an average particle size of 0.5 μm to 10 μm, more preferably 1.0 μm to 8.0 μm. The variation coefficient of the particle size distribution is preferably 50% or less, more preferably 40% or less, and particularly preferably 30% or less.

Here, the variation coefficient of the particle size distribution is a value represented by the following equation.

(Standard deviation of particle size) / (average value of particle size) × 100 The matting agent according to the present invention can be contained in any constituent layer, but is preferably used in order to achieve the object of the present invention. Is a constituent layer other than the photosensitive layer, and is more preferably the outermost layer as viewed from the support.

The method of adding the matting agent according to the present invention may be a method of dispersing in a coating solution in advance and applying the solution.
A method of spraying a matting agent after the application liquid is applied and before the drying is completed may be used. When a plurality of types of matting agents are added, both methods may be used in combination.

In the present invention, the most preferably used matting agent is colloidal silica. The main component of the colloidal silica is silicon dioxide, and may contain alumina or sodium aluminate as a minor component. These colloidal silicas may contain an inorganic base such as sodium hydroxide, potassium hydroxide, lithium hydroxide, or ammonia as a stabilizer.

Specific examples of these colloidal silicas include, for example, E.C. I. Du Pontde Nemouv
Ludox AS, L from s & Co (USA)
S, TM HS, etc., Snowtex 20, 30, C, O, etc. from Nissan Chemical Co., Ltd., Monsanto Co.
Zoon from Nalco Chem C
o from Nalcoag-1060, Nalcoag-
It is commercially available under trade names such as ID 21 to 64, and these can be easily obtained.

The colloidal silica-added layer is preferably a photosensitive layer and / or a hydrophilic colloid layer outside the photosensitive layer.

In the present invention, the total thickness of the photosensitive layer and the non-photosensitive layer is 5 to 14 μm, preferably 7 to 13 μm. If the thickness is too large, the developability during thermal development deteriorates, and if it is too thin, the adhesiveness deteriorates.

In the present invention, the amount of silver is 0.1 per m ² .
3 g or more and 1.6 g or less, and if it exceeds 1.6 g, the image storability after development is deteriorated, and when exposed to natural light, Dmi is obtained.
n is remarkable, and if it is less than 0.3 g, an appropriate Dma
x cannot be obtained.

By setting the amount of silver per 1 m ² to 1.6 g or less, film peeling after development is surprisingly improved, and the total thickness of the photosensitive layer and the non-photosensitive layer can be reduced to 14 μm or less. A level without any problems has been achieved.

The above-mentioned silver amount is a total amount of silver halide and organic silver salt, and is a value converted into silver amount.

In the present invention, the amount of silver halide relative to the total amount of silver is preferably at most 50%, more preferably at most 25%, even more preferably at most 0.1% by weight.
１５15%.

The photothermographic material of the present invention, which forms a photographic image by heat development, comprises a reducible silver source (organic silver salt), a catalytically active amount of silver halide, a hydrazine derivative,
The photothermographic material preferably contains a reducing agent and, if necessary, a color tone agent for suppressing the color tone of silver in a state of being usually dispersed in an (organic) binder matrix.

The photothermographic material of the present invention is stable at room temperature, but is developed by heating to a high temperature (for example, 80 ° C. to 220 ° C.) after exposure. Heating produces silver through an oxidation-reduction reaction between an organic silver salt (functioning as an oxidizing agent) and a reducing agent. This oxidation-reduction reaction is accelerated by the catalytic action of the latent image generated on the silver halide upon exposure. Silver produced by the reaction of the organic silver salt in the exposed areas provides a black image, which contrasts with the unexposed areas,
An image is formed. This reaction process proceeds without supplying a processing liquid such as water from the outside.

The photothermographic material of the present invention has at least one photosensitive layer on a support. A filter layer may be formed on the same side as or opposite to the photosensitive layer to control the amount or wavelength distribution of light passing through the photosensitive layer, or the photosensitive layer may contain a dye or pigment. . As the dye, the compounds described in Japanese Patent Application No. 7-11184 are preferred.

The light-sensitive layer may be composed of a plurality of layers, and the sensitivity may be changed to a high-sensitivity layer / low-sensitivity layer or a low-sensitivity layer / high-sensitivity layer for adjusting the gradation.

Various additives may be added to any of the photosensitive layer, the non-photosensitive layer, and other layers.

The photothermographic material of the present invention may contain, for example, a surfactant, an antioxidant, a stabilizer, a plasticizer, an ultraviolet absorber, and a coating aid.

It is preferable to add a color tone agent to the photothermographic material of the present invention. An example of a suitable toning agent is Resea
rc Disclosure No. 17029, which includes:

Imides (eg, phthalimide); cyclic imides, pyrazolin-5-ones, and quinazolinones (eg, succinimide, 3-phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and , 4-thiazolidinedione); naphthalimides (eg, N-hydroxy-1,8-naphthalimide); cobalt complexes (eg, hexamine trifluoroacetate of cobalt); mercaptans (eg, 3
-Mercapto-1,2,4-triazole); N- (aminomethyl) aryldicarboximides (for example,
N- (dimethylaminomethyl) phthalimide); blocked pyrazoles, isothiuronium (isoth
uronium) derivatives and certain photobleaching combinations (eg, N, N'-hexamethylene (1-carbamoyl-3,5-dimethylpyrazole), 1,8-
A combination of (3,6-dioxaoctane) bis (isothiuronium trifluoroacetate) and 2- (tribromomethylsulfonyl) benzothiazole; a merocyanine dye (e.g., 3-ethyl-5-((3-ethyl -2-benzothiazolinylidene (benzothiazolinylidene))-1-methylethylidene) -2-thio-2,4
-Oxazolidinedione); phthalazinone, a phthalazinone derivative or a metal salt of these derivatives (for example, 4-
(1-naphthyl) phthalazinone, 6-chlorophthalazinone, 5,7-dimethyloxyphthalazinone, and 2,3
-Dihydro-1,4-phthalazinedione); a combination of phthalazinone and a sulfinic acid derivative (for example, 6-chlorophthalazinone + sodium benzenesulfinate or 8-methylphthalazinone + sodium p-trisulfonate); phthalazine + phthalate Acid combinations; phthalazine (including phthalazine adducts) and maleic anhydride,
And phthalic acid, 2,3-naphthalenedicarboxylic acid or o
At least one selected from phenylene acid derivatives and anhydrides thereof (for example, phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride);
Quinazolinediones, benzoxazines, naloxazine derivatives; benzoxazine-2,4-diones (eg, 1,3-benzoxazine-2,4-dione); pyrimidines and asymmetric triazines (E.g., 2,4-dihydroxypyrimidine) and tetraazapentalene derivatives (e.g., 3,
6-dimercapto-1,4-diphenyl-1H, 4H-
2,3a, 5,6a-tetraazapentalene). Preferred toning agents are phthalazone or phthalazine.

The photothermographic material of the present invention may contain an antifoggant. What is known as the most effective antifoggant is mercury ion. Regarding the use of mercury compounds as antifoggants in photosensitive materials,
For example, it is disclosed in U.S. Pat. No. 3,589,903. However, mercury compounds are environmentally unfriendly. Non-mercury antifoggants include, for example, U.S. Pat.
No. 075 and 4,452,885 and JP-A-59
Preferred are antifoggants as disclosed in US Pat.

Particularly preferred non-mercury antifoggants are US Pat. Nos. 3,874,946 and 4,756,993.
No. 9, compound -C (X ₁ ) (X
₂ ) 1 represented by (X ₃ ), wherein X ₁ and X ₂ are halogen atoms, and X ₃ is hydrogen or a halogen atom.
It is a heterocyclic compound having the above substituent. As examples of suitable antifoggants, compounds described in paragraphs [0062] to [0063] of JP-A-9-90550 are preferably used.

Further, more preferred antifoggants are disclosed in US Pat. No. 5,028,523 and British Patent Application No. 92221.
No. 383.4, No. 9300147.7, No. 931
No. 1790.1.

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

Among them, a preferred support is a support of polyethylene terephthalate (hereinafter abbreviated as PET) and a plastic (hereinafter abbreviated as SPS) containing a styrene polymer having a syndiotactic structure.

The thickness of the support is preferably about 50 to 300 μm, more preferably 70 to 180 μm.

A plastic support which has been heat-treated can also be used. The plastics to be employed include the above-mentioned plastics. The heat treatment of the support means that after forming these supports and before the photosensitive layer is applied, at a temperature higher than the glass transition point of the support by 30 ° C. or more,
Preferably at a temperature higher than 35 ° C., more preferably 40 ° C.
Heating at a temperature higher than ℃. However, the effect of the present invention cannot be obtained by heating at a temperature exceeding the melting point of the support.

Next, the plastic used will be described.

PET is composed of polyethylene terephthalate in which all polyester components are used. In addition to polyethylene terephthalate, terephthalic acid, naphthalene-2,6-dicarboxylic acid, isophthalic acid, butylene dicarboxylic acid, and 5-sodium acid are used as acid components. Polyesters containing modified polyester components such as sulfoisophthalic acid, adipic acid, etc., and glycol components such as ethylene glycol, propylene glycol, butanediol, cyclohexane dimethanol, etc. in an amount of 10 mol% or less of the total polyester may be used.

SPS, unlike ordinary polystyrene (atactic polystyrene), is polystyrene having steric regularity. The regular stereoregular structure part of SPS is called a racemo chain, and it is preferable that there are more regular parts such as two, three, five or more. In the present invention, the racemo chain is 2 It is preferably 85% or more in the chain, 75% or more in the three chains, 50% or more in the five chains, and 30% or more in the further chains. The polymerization of SPS can be carried out according to the method described in JP-A-3-131843.

The method of forming a support and the method of producing an undercoat according to the present invention may be a known method, but preferably are described in paragraphs [0030] to [0] of JP-A-9-50094.
070].

[0105]

EXAMPLES The present invention will be described below in detail with reference to examples, but embodiments of the present invention are not limited thereto.

Example 1 [Preparation of Subbed Photographic Support] <Preparation of PET Subbed Photographic Support> A commercially available biaxially stretched and heat-fixed PET film having a thickness of 100 μm was coated on both sides with 8 w / m. Apply a corona discharge treatment for ² minutes, apply the following undercoating coating solution a-1 on one surface to a dry film thickness of 0.8 μm, and dry to form an undercoating layer A-1. Was coated with the following undercoating coating solution b-1 so as to have a dry film thickness of 0.8 μm and dried to obtain an undercoating layer B-1.

<< Undercoat Coating Solution a-1 >> Butyl acrylate (30% by weight) t-butyl acrylate (20% by weight) Styrene (25% by weight) 2-hydroxyethyl acrylate (25% by weight) copolymer latex liquid (Solid content 30%) 270 g (C-1) 0.6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g Finished to 1 liter with water.

<< Undercoat Coating Solution b-1 >> Butyl acrylate (40% by weight) Styrene (20% by weight) Glycidyl acrylate (40% by weight) copolymer latex liquid (solid content 30%) 270 g (C-1) 0.6 g Hexamethylene-1,6-bis (ethylene urea) 0.8 g Make up to 1 liter with water.

Subsequently, the undercoat layer A-1 and the undercoat layer B-1
A corona discharge of 8 w / m ² · min is applied to the upper surface of the lower layer, and the lower layer upper layer coating solution a-2 is coated on the lower layer A-1 so as to have a dry film thickness of 0.1 μm. Sublayer B as Layer A-2
-1 is coated with the following undercoating layer coating solution b-2 having a dry film thickness of 0.
Coating was performed as a subbing upper layer B-2 having an antistatic function so as to have a thickness of 8 μm.

<< Coating Solution a-2 for Lower Substrate >> Gelatin 0.4 g / m ² Weight (C-1) 0.2 g (C-2) 0.2 g (C-3) 0.1 g Silica particles ( (Average particle size: 3 μm) 0.1 g Finish to 1 liter with water.

<< Coating solution b-2 for lower undercoat >> (C-4) 60 g Latex solution containing (C-5) as a component (solid content: 20%) 80 g Ammonium sulfate 0.5 g (C-6) 12 g Polyethylene glycol ( (Weight average molecular weight: 600) 6 g Finished to 1 liter with water.

[0112]

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[0113]

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(Preparation of Emulsion A) In 900 ml of water, 7.5 g of inert gelatin and 10 mg of potassium bromide were dissolved and adjusted to a temperature of 35 ° C. and a pH of 3.0.
g of an aqueous solution containing potassium bromide and potassium iodide in a molar ratio of (98/2) and iridium chloride in an amount of 1 × 10 ⁻⁴ mol per mol of silver, and pAg of 7.7.
, And added over 10 minutes by a controlled double jet method. Thereafter, 0.3 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, the pH was adjusted to 5 with NaOH, and the average particle size was 0.0.
Cubic silver iodobromide grains having a size of 6 μm, a variation coefficient of the projected diameter area of 8%, and a [100] face ratio of 87% were obtained. This emulsion was subjected to coagulation sedimentation using a gelatin coagulant and desalting treatment, and then 0.1 g of phenoxyethanol was added to the emulsion to give a pH of 5.9 and a pAg of 7.5.
To obtain a silver halide emulsion.

According to the method of Example 1 of JP-A-9-127463, silver behenate was prepared by the following method.

(Preparation of Na Behenate Solution) 34 g of behenic acid was dissolved in 340 ml of isopropanol at 65 ° C. Next, while stirring, a 0.25N aqueous sodium hydroxide solution was added so as to have a pH of 8.7. At this time, about 400 ml of the sodium hydroxide aqueous solution was required. Next, the aqueous sodium behenate solution was concentrated under reduced pressure to adjust the concentration of sodium behenate to 8.9% by weight.

(Preparation of silver behenate) 2.9 ml of a solution prepared by dissolving 30 g of ossein gelatin in 750 ml of distilled water.
A 4M silver nitrate solution was added to adjust the silver potential to 400 mV. 78 ° C using a controlled double jet method
374 ml of the above sodium behenate solution at a temperature of 4
At a rate of 4.6 ml / min, a 2.94 M silver nitrate aqueous solution was added so that the silver potential became 400 mV. The amounts of sodium behenate and silver nitrate used at the time of addition were 0.092 mol and 0.101 mol, respectively.

After the addition was completed, the mixture was further stirred for 30 minutes, and the water-soluble salts were removed by ultrafiltration.

(Preparation of Photosensitive Emulsion) The silver halide emulsion was added to this silver behenate dispersion so as to have a silver ratio as shown in Table 1, and the mixture was further stirred with n-acetic acid of polyvinyl acetate.
100 g of a butyl solution (1.2 wt%) is gradually added to form a floc of the dispersion, water is removed, washed twice and water is removed, and then polyvinyl butyral is used as a binder (average molecular weight 3000). 60 g of a 1: 2 mixed solution of 2.5 wt% of butyl acetate and isopropyl alcohol was added with stirring, and polyvinyl butyral (average molecular weight 4000) as a binder was added to the thus obtained mixture of behenic acid and silver halide. ) And isopropyl alcohol.

The following layers are sequentially formed on the support,
A sample was prepared. The drying was performed at 75 ° C. for 5 minutes.

Back side coating : A solution having the following composition was applied to a dry film thickness of 5 μm. Polyvinyl butyral (10% isopropanol solution) 150 ml Dye-B 70 mg Dye-C 70 mg

[0122]

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Photosensitive layer side coated photosensitive layer: A solution having the following composition is coated so that polyvinyl butyral as a binder has a film thickness after drying shown in Table 1 so that the amount of silver applied is as shown in Table 1. Was applied in the same manner.

Emulsion A An amount that gives a silver amount of 3 g / m ² Sensitizing dye-1 (0.1% DMF solution) 2 mg Antifoggant-1 (0.01% methanol solution) 3 ml Antifoggant-2 (1 8 ml Antifoggant-3 (2.4% DMF solution) 5 ml Phthalazone (4.5% DMF solution) 8 ml Developer-1 (10% acetone solution) 13 ml Hardening agent H (1% methanol solution) / DMF = 4: 1 solution) 2ml

[0125]

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[0126]

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Surface protective layer : A solution having the following composition was applied on each photosensitive layer so as to have a thickness after drying.

Acetone 175 ml 2-propanol 40 ml methanol 15 ml cellulose acetate 8.0 g phthalazine 1.0 g 4-methylphthalic acid 0.72 g tetrachlorophthalic acid 0.22 g tetrachlorophthalic anhydride 0.5 g matting agent

<Evaluation of Photographic Performance> After exposing the photographic material with a laser sensitometer equipped with an 820 nm diode, the photographic material was processed (developed) at 120 ° C. for 15 seconds, and the obtained image was evaluated with a densitometer. Was. The result of the measurement is Dmin,
The evaluation was made based on the sensitivity (reciprocal of the ratio of the exposure amount giving a density higher than Dmin by 1.0).

<Evaluation of Storage Property> Two samples treated in the same manner as in the evaluation of photographic performance were stored, one of which was shielded from light at 25 ° C. and 55%, and the other was stored at 25 ° C. and 55% for 7 days. After exposure to natural light, the density of both fog portions was measured. Table 2 shows the increase in fog obtained by the following equation.

(Increase in fog) = (Fog after exposure to natural light) − (Fog after storage under light shielding)

<Evaluation of Adhesiveness After Development> Twenty-six vertical and horizontal scratches were made with a razor on the emulsion surface of a light-sensitive material cut into a length of 3 cm and a length of 12 cm, and 25 cells were formed. A Mylar tape (manufactured by Nitto Denko Corporation) having a width of 25 mm is adhered on this and strongly pressed, and then quickly peeled at a peeling angle of 90 degrees. The test was conducted at 120 ° C1 with a hot roller type developing machine.
Performed on samples developed for 5 seconds. The results are shown in Table 2 according to the ranks of 1 to 5 according to the number of peeling meshes as follows.

Separation 0 cells ... 5 Separation to 3 cells ... 4 Separation to 7 cells ... 3 Separation to 15 cells ... 2 Separation to 25 cells ... 1

[0134]

[Table 1]

[0135]

[Table 2]

[0136]

As is clear from the above examples, according to the present invention, it is possible to provide a photothermographic material having excellent long-term storage properties after development and having improved film formation after development. it can.

Claims (4)

[Claims] A photosensitive layer containing photosensitive silver halide grains is provided on at least one side of the support, and at least one non-photosensitive layer is provided adjacent to the photosensitive layer and remote from the support. In a photothermographic material having at least two layers, the total thickness of the photosensitive layer and the non-photosensitive layer is 5 to 14 μm, and the amount of silver is 0.3 to 1.6 g / m ^2. Photothermographic material. 2. The photothermographic material according to claim 1, wherein the photosensitive layer contains at least an organic silver salt and a reducing agent. 3. The method according to claim 2, wherein the photosensitive layer and / or the non-photosensitive layer
3. The photothermographic material according to claim 1, further comprising an inorganic matting agent. 4. The photothermographic material according to claim 1, wherein the photothermographic material is infrared-sensitized for infrared laser exposure.