JP2002062614A - Heat developable material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developable material excellent in scuffling resistance in development, less liable to stain, excellent also in the stability of photographic performance in storage and the shelf stability of an image at high humidity after development, ensuring superior heat decolorability of a heat decolorable dye and controlling print-out silver after heat development. SOLUTION: In the heat developable material with a photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a reducing agent and a binder and a layer adjacent to the photosensitive layer on one side of the base and a backing layer and a backing protective layer on the other side, a phosphazene compound is contained in at least one of the layers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-developable material for forming an image by heat development.
Stain by developing means, stability of photographic performance during storage, high humidity storage stability of developed image, bakeout fog after development, thermal decolorization of dye to achieve higher sharpness, development The present invention relates to a heat-developable material in which the remaining color afterward and the color tone of an obtained image are improved.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for photothermographic materials which do not generate waste liquid due to wet processing from the viewpoints of environmental protection and workability in the fields of medical treatment and printing. There is a need for technology relating to photothermographic materials for photographic technology applications that can form images. Since these photothermographic materials are usually developed at a temperature of 80 ° C. or higher, they are called heat development materials.

Conventionally, this type of heat-developable material has a light-sensitive layer containing high-sensitivity silver halide grains spectrally sensitized with a dye, an organic silver salt and a reducing agent, and light irradiated toward the light-sensitive layer. It comprises an irradiation preventing layer (AI layer) or a backing layer (BC layer) for preventing the light from passing through without being absorbed and being irregularly reflected at the interface of the support, the intermediate layer, the adhesive layer, and the like. A protective layer is provided on the BC layer to prevent scratches during handling.

In general, a heat-developable material requires a step of uniformly heating it after imagewise exposure in order to reduce the organic silver salt in the image area of the photosensitive layer. There is also microwave development, but most of them are heated and developed in contact with a heat roller. At this time, make sure that the contact between the photosensitive surface and the heat roller does not damage it, and that the additives of the photosensitive layer diffuse to the surface due to volatilization and melting, and do not adhere to the heat roller to cause contamination. It is important to:

For this reason, it is considered that the binder in the protective layer is cross-linked to prevent adhesion, and US Pat. Nos. 4,886,739, 4,942,115, and 5,264,334 disclose cross-linking techniques. The use of a polyalkoxysilane compound is disclosed in, for example, US Pat. It is stated that these compounds are hydrolyzed by heat and the exposed hydroxy groups are combined with a binder to enhance cross-linking. However, when the hydrolysis is performed by the heat, alcohol and moisture are released, and these are diffused into the support, and the support is curled, thereby causing poor conveyance. As a countermeasure against this, there are disadvantages such as the need for a diffusion preventing layer for water and alcohol.

On the other hand, US Pat. No. 4,828,971,
No. 5,891,610 and the like describe the use of polysilicate compounds. This compound is less hydrolyzable than polyalkoxysilane, but has drawbacks such as easy cracking of the dried film. Therefore, US Pat. No. 3,489,567 discloses a method for modifying the film surface of a heat developing material.
No. 3,885,965 discloses adding a polysiloxane compound as a lubricant. However, in these, although the slip of the film surface of the heat developing material is improved, no study has been made on the scratch resistance of the heat developing material, the contamination of the additive of the heat developing material to the heat roller, and the like. .

On the other hand, an anti-irradiation dye for improving sharpness is used in the heat-developable material. When the image is exposed to light, irradiation light not absorbed by the dye may cause an irradiation between the interlayer in the film and the support. Irregular reflection at the body interface causes loss of image sharpness. In order to solve this problem, a dye that absorbs unnecessary diffusely reflected light is used in the BC layer. The AI layer is set mainly between the photosensitive layer and the support, and the BC layer is set on the opposite side of the photosensitive layer with respect to the support. The anti-irradiation dye and anti-halation dye used in the AI layer and the BC layer become residual colors if absorption remains in the visible part after development, hindering discrimination of a silver image. Therefore, it was necessary to reduce this absorption as much as possible. For this reason, decolorizable dyes which are decomposed by heat during development and decolorized during development and which do not stain the thermally developed material and the heat roller during development have been studied, and many inventions have already been proposed. For example, JP-A-53-132334, JP-A-60-111239, U.S. Pat.
No. 8, 4,524, 128, 4,594, 312
Nos. 4,994,356 and 5,135,842
Nos. 5,314,795 and 5,324,627
No. 5,384,237 and European Patent No. 911,69.
No. 3 has been proposed. However, the problem of the residual color and stain after development of the above-mentioned heat developing material, and the problem of scratches due to the heat roller or heat drum for development are not only the problems of the dyes of the AI layer and the BC layer, but also the materials of the photosensitive layer and the protective layer. It turned out that there was a problem with the entangled overall membrane constituent material.

Further, since the heat-developable material does not have a step of fixing after the development, in order to prevent silver halide grains from being exposed to visible light to form baked-out silver and increasing fog,
A polyhalomethane compound is added. However, addition of the polyhalomethane compound does not sufficiently prevent baked silver, and there has been a need for a method of using the polyhalomethane compound more effectively.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and a first object of the present invention is to provide a device which is excellent in scratch resistance at the time of development and causes stains by the developing means. Another object of the present invention is to provide a heat-developable material which is excellent in stability of photographic performance during storage and high-humidity storage stability of an image after development. A second object of the present invention is to provide a heat-developable material in which fogging due to silver developed after development is suppressed. Further, a third object of the present invention is to provide a thermal developing method in which a dye for improving high sharpness is excellent in thermal decoloring property, the residual color after development is small, and the color tone of an obtained image is stable. It is to provide materials.

[0010]

The above object of the present invention is achieved by the following constitution.

1. Photosensitive silver halide grains on a support,
A photosensitive layer containing an organic silver salt, a reducing agent and a binder, a layer adjacent to the photosensitive layer, a heat-developable material having a backing layer and a backing protective layer on a support opposite to the side where the photosensitive layer is located; A heat-developable material comprising a phosphazene compound in at least one of the layers.

2. 2. The heat development material according to 1, wherein the phosphazene compound is a compound represented by the general formula (1).

3. 3. The heat-developable material according to 1 or 2, wherein the photosensitive layer or a layer adjacent to the photosensitive layer contains a polyhalomethane compound.

4. The photosensitive layer, a layer adjacent to the photosensitive layer,
4. The thermal development according to 1, 2, or 3, wherein at least one layer selected from a backing layer and a backing protective layer contains at least one selected from a heat-decolorable dye and a base-generating precursor compound. material.

Hereinafter, the present invention will be described in detail. The heat-developable material of the present invention usually has at least two or more layer constitutions in which a photosensitive layer and a layer adjacent to the photosensitive layer are provided on a support, and the support on the side opposite to the side where the photosensitive layer is provided It has a backing layer provided thereon, its protective layer, and the like. The photosensitive layer of the heat-developable material contains photosensitive silver halide grains that may be sensitized with a spectral sensitizing dye, and the photosensitive layer or an adjacent layer thereof includes an organic silver salt serving as a silver source. A reducing agent for developing a silver salt to form a silver image is contained, and the phosphazene compound of the present invention is contained. The phosphazene compound is
The film may be cured by a crosslinking reaction with the binder, or may be present only in the film without being cured.
More preferably, a hydrazine compound or the like as a silver image hardening agent is contained. The photosensitive layer of the heat-developable material and the layer adjacent to the photosensitive layer contain a polymer binder, a hydrophilic binder, a hydrophobic binder, particularly preferably a latex, and more preferably a cross-linking of the binder. An alkoxysilane compound or an isocyanate compound to be cured is contained. In the above-mentioned heat developing material, an AI layer or a BC layer containing a dye for preventing irradiation or halation is provided as necessary. Further, the photosensitive layer of the above-mentioned heat development material may contain a color tone agent for adjusting the color tone of a silver image as needed.

Hereinafter, the phosphazene compound, the heat-decolorable dye, the basic generation precursor compound, and the polyhalomethane compound contained in the heat-developable material of the present invention will be sequentially described. Incidentally, the photosensitive silver halide grains contained in the photosensitive layer of the heat-developable material, the organic silver salt contained in the photosensitive layer or a layer adjacent thereto, a reducing agent, a polymer binder, and hydrazine optionally contained therein Compounds, color tones and the like will be further described later.

The phosphazene compound of the present invention will be described. The phosphazene compound is a compound having phosphorus and nitrogen as main constituent atoms, and various groups can be introduced into a phosphorus atom. Phosphazenes are classified into two types: cyclophosphazenes, each of which is composed of three phosphazene units in which one phosphorus and nitrogen are bonded to form a 6-membered ring, and polyphosphazenes obtained by ring-opening polymerization of these. A substituent can be introduced into the phosphorus atom. The introduction of a substituent
It can be synthesized by condensing or transesterifying 2,4,4,6,6-hexachlorocyclophosphazene with a compound having a hydroxyl group or an amino group as a starting material. In the case of cyclophosphazene, since a maximum of six substituents can be introduced into one molecule, the substituent can be introduced in a dendritic manner, and a dendrimer molecule can be formed. As the phosphazene compound of the present invention having the specific preferred structure described above, a compound represented by formula (1) can be preferably mentioned.

In the general formula (1), R ¹ , R ² , R
^{As the} alkyl group, alkenyl group and alkynyl group represented by ³ and R ⁴ , those each having 1 to 30 carbon atoms which may be substituted are preferable, for example, methyl group, ethyl group, butyl group, octyl group, dodecyl Group, trifluorobutyl group, pentafluoropropyl group, butenyl group, nonenyl group, etc., ethynyl group, propynyl group and the like.

Examples of the aromatic group include a phenyl group,
p-hydroxyphenyl group, p-aminophenyl group, p
-Glycidylphenyl group, p-methylphenyl group, p-
Examples include a methoxyphenyl group, a p-cyanophenyl group, a naphthyl group, a 1,5-dimethylnaphthyl group, and a 2,6-dimethylnaphthyl group.

Examples of the heterocyclic group include a pyridyl group, a furyl group, an imidazolyl group, a triazolyl group, a thiazolyl group and the like.

Examples of the substituted oxy group include methoxy, ethoxy, butoxy, octoxy, butenooxy, phenoxy, p-aminophenoxy, p-amino
A glycidylphenoxy group, a p-cyanobutylphenoxy group, a p-trimethoxysilanopropyloxy-phenoxy group and the like.

Examples of the substituted amino group include a phenylamino group, a thiadiazoleamino group, a trimethoxysilanopropylamino group, a p-trimethoxypropyloxyphenoxyamino group and the like.

As the halogen atom, a chlorine atom or a bromine atom is preferable, and the alkyl group or the alkenyl group may contain a straight-chained or branched, saturated or unsaturated.

Phosphazene containing an epoxy group, isocyano group, polyalkoxysilano group, etc., which undergoes a crosslinking reaction with a binder in the phosphazene molecule is a hydrophilic or hydrophobic polymer containing a polyvinyl alcohol derivative, a cellulose derivative, gelatin, or a hydroxyalkyl acrylate unit. It is particularly preferable because the thermal strength of a heat-developable material using a binder having a hydroxyl group or an amino group as described above can increase the film strength and improve the scratch resistance.

Hereinafter, preferred specific examples of the phosphazene compound of the present invention are cyclophosphazene (1-1 to 1-1).
2) System and linear polyphosphazene (1-13 to 1-22)
Although shown for the system, the invention is not limited thereto.

[0026]

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[0027]

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[0028]

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The phosphazene compounds of the present invention are disclosed in JP-A-6-135977, JP-A-6-220077, and 9-
Nos. 183855, 10-273512 and 11
The compound can be synthesized with reference to -044955 or the like. These phosphazene compounds can be added in the production of the heat-developable material according to a known addition method. It can be added after being dissolved in alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone and acetone, and polar solvents such as dimethyl sulfoxide and dimethylformamide. Also,
Fine particles of 1 μm or less can be dispersed in water or an organic solvent by sand mill dispersion, jet mill dispersion, ultrasonic dispersion or homogenizer dispersion, and then added. The amount of addition is preferably in the range of 1 / 1,000% by mass to 60% by mass in the coating solution, particularly preferably in the range of 1/100% by mass to 30% by mass. Can be used. In terms of the number of moles, it can be added to the heat-developable material at 10 ⁻⁶ mol to 10 ⁻² mol / m ² . When the phosphazene compound is a polymer, the phosphazene compound can be added as a unit containing one phosphorus atom and one nitrogen atom as one molar equivalent. Also in this case, it is preferable to add to the heat developing material in the range of 10 ^-6 to 10 ^-2 molar equivalent / m ² .

<Thermal Decolorable Dye> As the thermal decolorizable dye of the present invention, a thermal decolorable dye represented by the following general formula (2) is preferable.

[0031]

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In the formula, each of Q ¹ and Q ² represents a 5- or 6-membered ring which may have a substituent and an atom group forming a condensed ring with the ring, and L ²¹ , L ²² and L ²³ represents a linking group having a methine chain connecting the ring containing ring, Q ² containing Q ^1, n represents an integer of 0 to 5. R ²¹ and R ²²
Represents a substituent, and at least one of R ²¹ and R ²² is-
CH ₂ CO-X ¹ -R ²³ or ^{_{-CH 2 CO-N (R 24}} ) R
²⁵ , X ¹ represents an oxygen atom or a sulfur atom,
R ²³ , R ²⁴ and R ²⁵ each represent a substituent. Also,
The ring on containing a ring or Q ² contains a Q ^1, or on the condensed ring with ring containing ring or Q ² contains a Q ^1, although it is preferred to have the -T-R ²⁶ group, limited to It is not something to be done. T represents SO, SO ₂ or a sulfur atom, and R ²⁶ represents a substituent. X ^- represents an anion.

The optionally substituted 5- or 6-membered ring formed by Q ¹ and Q ² or a condensed ring with the ring is preferably, for example, a pyridine ring, a pyrimidine ring, an imidazole Ring, benzimidazole ring, oxazole ring, benzoxazole ring, thiazole ring, benzothiazole ring, thiadiazole ring, isobenzofuran ring and the like. The linking group having a methine chain connecting the ring containing ring, Q ² comprising Q ¹ represented by L ^21, L ²² and L ^23, linking groups lined 1-9 methine chain. The methine chain may contain one or more hexene rings, or may have a halogen atom, an alkyl group substituted with a halogen atom, or an alkenyl group.

R ²¹ , R ²² , R ²³ , R ²⁴ , R ²⁵ and R ²⁶
As the substituent represented by each, for example, an aliphatic group having 1 to 30 carbon atoms which may have a substituent (for example,
Methyl group, ethyl group, butyl group, octyl group, dodecyl group, eicosyl group, propenyl group, butenyl group, cyclohexyl group, acetylenyl group, etc.), aromatic group (for example,
A phenyl group, a naphthyl group, or a heterocyclic group (for example, a pyridyl group, a pyrimidyl group, an imidazolyl group, a triazolyl group, a thiazolyl group, a benzotriazolyl group, a benzimidazolyl group, a benzoxazolyl group, a furyl group, a thiophene) Yl group etc.). R
²⁴ and R ²⁵ may form a ring, such as a piperidine ring, morpholine ring, pyridazine ring, pyrimidine ring, piperazine ring, s-triazine ring, indole ring, benzimidazole ring, quinoline ring, Examples include a carbazole ring, an acridine ring, a phenothiazine ring, a phenanthroline ring and the like.

Preferred specific examples of the heat-decolorable dye represented by the formula (2) are shown below.

[0036]

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[0037]

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[0038]

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The heat-decolorizable dye preferably used in the present invention can be synthesized according to a method for synthesizing a cyanine dye or a hemicyanine dye. The part of the substituent that contributes to decoloration can be synthesized with reference to EP 911,693.

When the heat-decolorable dye preferably used in the present invention is added to the antiirradiation layer or the backing layer, it is preferably 10 ^-2 to 10 ^-6 mol / m ² . In addition, when it is added to both the anti-irradiation layer and the backing layer, it is preferable to distribute and add in a ratio of 1:10 to 10: 1.

When adding, it may be added to an organic solvent such as an alcohol or a ketone, but it can be added in the form of fine particles dispersed in water. The average particle diameter of the fine particles is 1
The particles can be dispersed in a range from 0 nm (nanometer) to 10 μm (micrometer), but as far as possible, fine particles and monodispersion are preferred. Monodispersity expressed as a value obtained by dividing the standard deviation of the particle diameter by the average particle diameter and multiplying by 100 is 1 to 30%.
Is preferable, and 1 to 20% is more preferable.

<Base-Generating Precursor Compound> The base-generating precursor compound which promotes the thermal decoloring property of the thermo-decolorable dye preferably used in the present invention is a compound in which a base component and an acid component form a stable ionic bond at room temperature. Although it is formed, it is a precursor compound that is decomposed into a base component and an acid component by heat, and the decomposed base component acts on the dye as an active nucleophile and is presumed to decolorize. As the base generating precursor compound preferably used in the present invention, a base generating precursor compound represented by the following general formula (3) is preferable.

[0043]

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In the formula, Z ¹ and Z ² represent an atom group necessary for forming a 4- to 9-membered ring which may have a substituent, by L ³¹
Represents a group that bonds a ring containing Z ¹ to a ring containing Z ² , and Y represents a monovalent substituent. n represents 0 or an integer of 1 to 4,
When n is 2 or more, Y may be the same or different, and adjacent substituents may form a ring.

Z ¹ and Z ² are preferably an alkylene group having 1 to 5 carbon atoms, for example, a methylene group, a dimethylene group, a trimethylene group, a pentamethylene group, a hexamethylene group, and the like. May be provided. L ³¹ is a bonding group, which is a divalent having two bonding sites derived from a saturated or unsaturated aliphatic group having 1 to 30 carbon atoms, an aromatic group, and a hetero ring, each of which may have a substituent. (Having two binding sites). For example, ethylene group, propylene group, butylene group, isobutylene group, octylene group, dodecylene group, phenylene group,
Examples thereof include a biphenylene group, a naphthylene group and the like, and compounds having a substituent at these carbon atoms.

Examples of the monovalent substituent represented by Y include a hydrogen atom, a halogen atom (such as a chlorine atom and a bromine atom), a phenyl group, a methylsulfonyl group, and a phenylsulfonyl group.

The base generating precursor compounds preferably used in the present invention are described in JP-B-7-59545 and JP-B-8-59545.
It can be synthesized according to the method described in No. 10321.

Preferred specific examples of the base-generating precursor compound represented by the general formula (3) are shown below.

[0049]

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[0050]

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Formula (3) preferably used in the present invention
The method for adding the base-generating precursor compound represented by formula (1) can be added according to a known method. It can be added after being dissolved in alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone and acetone, and polar solvents such as dimethyl sulfoxide and dimethylformamide. The addition amount is 100 to the heat-decolorable dye.
A range from 1 / mole to 100-fold mol can be selected. A particularly preferred addition amount is in the range of 1/10 mol to 10 times mol with respect to the thermal decolorizable dye. In addition to dissolving in a solvent, 1μ by sand mill dispersion, jet mill dispersion, ultrasonic dispersion or homogenizer dispersion
m or less and dispersed in water or an organic solvent. Many techniques are disclosed for the fine particle dispersion technique.
Fine particle dispersions of 5 microns to 10 microns can be added. In order to use fine particles, the monodispersity, expressed as a value obtained by dividing the standard deviation of the particle diameter by the average particle diameter and multiplying by 100, is preferably 1 to 30, and more preferably 1 to 20.

(Polyhalomethane Compound) The polyhalomethane compound preferably used in the present invention is a compound having a polyhalomethane group in which at least two or more halogen atoms are present in one molecule. Substituted on an aromatic ring group or a heterocyclic group. The aromatic ring group or the heterocyclic group may be further connected to the aromatic ring or the hetero ring via a divalent linking group. As the aromatic ring group, a phenyl group or a naphthalene group is preferable, and a logen atom (for example,
It may have a substituent such as a chlorine atom, a bromine atom, a fluorine atom or the like, or an alkyl group (eg, a methyl group, an ethyl group, a butyl group, an octyl group, a dodecyl group, an octadecyl group). Examples of the heterocyclic group include, for example, a group derived from a pyridyl group, a pyrimidyl group, a quinolyl group, a furanyl group, a thiophenyl group, an imidazolyl group, a triazolyl group, an oxazolyl group, a thiazolyl group, a thiadiazolyl group, an oxadiazolyl group. The ring of the heterocyclic group may have the same substituent as in the case of the aromatic ring group.
The group adjacent to the polyhalomethane group is preferably a sulfonyl group or a carbonyl group, but may be directly bonded on an aromatic ring or a hetero ring, and the type of bonding is not limited. The halogen atom of the polyhalomethane group is preferably a bromine atom, but may be chlorine, fluorine, iodine or a combination thereof.

The addition amount of the polyhalomethane compound preferably used in the present invention is 10 ^-6 per mol of silver halide.
It can be added in the range of from mol to 10 ^-2 mol. The addition position is not limited to the photosensitive layer in which silver halide is present, but may be an adjacent layer or an undercoat layer. The addition method can be the same as that of the phosphazene compound or the heat-decolorable dye.

Preferred specific examples of the polyhalomethane compound preferably used in the present invention are shown below.

[0055]

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Next, the organic silver salt, the reducing agent, the photosensitive silver halide particles, the hydrazine compound, the binder, the color tone, the dye, the matting agent and other supports used in the heat developing material of the present invention will be explained in order.

(Organic Silver Salt) The organic silver salt contained in the heat-developable material of the present invention is a reducible silver source, and an organic acid, heteroorganic acid and acid polymer silver containing a reducible silver ion source. Salts and the like are used. Further, when the ligand is 4.0 to 4.0.
Organic or inorganic silver salt complexes having a total stability constant for silver ions of 10.0 are also useful. An example of a silver salt is Rese
archDisclosure Nos. 17029 and 29
963, and include: silver salts of organic acids (eg, silver salts of gallic acid, oxalic acid, behenic acid, stearic acid, palmitic acid, lauric acid, etc.); carboxyalkylthiourea salts of silver (E.g., silver salts such as 1- (3-carboxypropyl) thiourea, 1- (3-carboxypropyl) -3,3-dimethylthiourea); and polymer reaction products of aldehydes and hydroxy-substituted aromatic carboxylic acids. Silver complexes (for example, aldehydes such as formaldehyde, acetaldehyde, butyraldehyde and salicylic acid, benzylic acid 3,5-dihydroxybenzoic acid,
Silver complexes of polymer reaction products with hydroxy-substituted substituted aromatic carboxylic acids such as 5,5-thiodisalicylic acid);
Silver salts or complexes of thiones (eg, 3- (2-carboxyethyl) -4-hydroxymethyl-4-thiazoline-
2-thione, 3-carboxymethyl-4-methyl-4-
Silver salts or complexes such as thiazoline-2-thione); from imidazole, pyrazole, urazole, 1,2,4-thiazole and 1H-tetrazole, 3-amino-5-benzylthio-1,2,4-triazole and benzotriazole Complexes or salts of selected nitrogen acids with silver; silver salts such as saccharin and 5-chlorosalicylaldoxime; and silver salts of mercaptides.

(Reducing Agent) Examples of preferred reducing agents contained in the heat-developable material of the present invention are described in US Pat. No. 3,770,44.
No. 8, 3,773, 512, 3,593, 863
No. etc., and Research Discl
Osure Nos. 17029 and 29996, and include:

Aminohydroxycycloalkenone compounds (eg, 2-hydroxy-3-piperidino-2-cyclohexenone); aminoreductone esters (eg, piperidinohexose reductone monoacetate) as precursors of the reducing agent; Hydroxyurea derivatives (eg, Np-methylphenyl-N-hydroxyurea);
Hydrazones of aldehydes or ketones (e.g., anthracenaldehyde 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);
-Tetrazolylthiohydroquinones (e.g., 2-methyl-5- (1-phenyl-5-tetrazolylthio) hydroquinone); tetrahydroquinoxalines (e.g.,
1,2,3,4-tetrahydroquinoxaline); amide oximes; azines; a combination of aliphatic carboxylic acid arylhydrazides and ascorbic acid; a combination of polyhydroxybenzene and hydroxylamine; reductone and / or hydrazine; hydroxamic acids A combination of azines and sulfonamidophenols; α
A combination of bis-β-naphthol and a 1,3-dihydroxybenzene derivative; 5
-Pyrazolones; sulfonamidophenol reducing agent; 2
-Phenylindane-1,3-dione and the like; chroman;
1,4-dihydropyridines (for example, 2,6-dimethoxy-3,5-dicarbethoxy-1,4-dihydropyridine); bisphenols (for example, bis (2-hydroxy-3-t-butyl-5-methyl) Phenyl) methane, bis (6-hydroxy-m-tri) mesitol (m
esitol), 2,2-bis (4-hydroxy-3-
Methylphenyl) propane, 4,4-ethylidene-bis (2-t-butyl-6-methylphenol)), ultraviolet-sensitive ascorbic acid derivatives; hindered phenols; 3-pyrazolidones. Among them, particularly preferred reducing agents are hindered phenols. Examples of the hindered phenols include compounds represented by the following general formula (A).

[0060]

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In the formula, R is a hydrogen atom or a group having 1 to 1 carbon atoms.
10 alkyl groups (for example, i-propyl group, butyl group, 2,4,4-trimethylpentyl group, etc.)
R ′ and R ″ represent an alkyl group having 1 to 5 carbon atoms (eg, a methyl group, an ethyl group, a t-butyl group, etc.).

Hereinafter, specific examples of the compound represented by formula (A) will be shown. However, the present invention is not limited to the following compounds.

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

(Photosensitive silver halide grains) The photosensitive silver halide contained in the photosensitive layer of the heat-developable material of the present invention is:
Any method known in the field of photographic technology such as a single jet or double jet method, for example, an ammonia method emulsion, a neutral method, prepared in advance by any method such as an acid method, and then mixed with other components of the present invention. It can be mixed and introduced into the composition used in the present invention. In this case, in order to sufficiently contact the photosensitive silver halide and the organic silver salt,
For example, US Pat. Nos. 3,706,564 and 3,7 as protective polymers for preparing photosensitive silver halide.
No. 06,565, No. 3,713,833, No. 3,
No. 748,143, British Patent No. 1,362,970, which uses polymers other than gelatin, such as polyvinyl acetals, as protective polymers, while those described in British Patent No. 1,354,186. Means for enzymatically decomposing gelatin in a photosensitive silver halide emulsion,
As described in U.S. Pat. No. 4,076,539, various methods such as a method of preparing photosensitive silver halide grains in the presence of a surfactant and a method of using no protective polymer can be applied. it can.

The photosensitive silver halide preferably has a small grain size in order to suppress white turbidity after image formation and to obtain good image quality. The average particle size is 0.
1 μm or less, preferably 0.01 to 0.1 μm, particularly preferably 0.02 to 0.08 μm. The shape of the silver halide is not particularly limited, and may be cubic, octahedral, so-called normal crystals, or non-normal crystals, such as spherical, rod-shaped, or tabular grains. The silver halide composition is not particularly limited, and may be any of silver chloride, silver chlorobromide, silver chloroiodobromide, silver bromide, silver iodobromide, and silver iodide.

The amount of the silver halide is 50% by mass or less, preferably 25 to 0.1% by mass, more preferably 15 to 0.1% by mass based on the total amount of the silver halide and the organic silver salt described below.
% By weight.

The photosensitive silver halide used in the photothermographic material of the present invention is also disclosed in British Patent No. 1,447,454.
As described in the above item, when preparing an organic silver salt, a halogen component such as a halide ion is made to coexist with an organic silver salt forming component, and silver ions are implanted into this to almost simultaneously with the generation of the organic silver salt. Can be generated.

As another method, a silver halide forming component is allowed to act on a previously prepared solution or dispersion of an organic silver salt or a sheet material containing the organic silver salt, so that a part of the organic silver salt is exposed to light. It can also be converted to neutral silver halide. The silver halide thus formed is in effective contact with the organic silver salt and exhibits a preferable action. A silver halide-forming component is a compound capable of forming a photosensitive silver halide by reacting with an organic silver salt, and which compound is applicable and effective is determined by the following simple test. I can do it. That is, an organic silver salt is mixed with a compound to be tested, and if necessary, after heating, it is examined by an X-ray diffraction method whether there is a peak specific to silver halide. Silver halide-forming components confirmed to be effective by such tests include inorganic halides, onium halides, halogenated hydrocarbons, N-halogen compounds, and other halogen-containing compounds. Are U.S. Pat. Nos. 4,009,039, 3,457,075, 4,003,749, British Patent 1,498,956, and JP-A-53-2702.
No. 7, No. 53-25420 and the like.

These silver halides are used in a small amount stoichiometrically with respect to the organic silver salt. Usually, the range is from 0.001 mol to 0.7 mol, preferably from 0.03 mol to 0.5 mol, per 1 mol of the organic silver salt. Two or more silver halide forming components may be used in combination within the above range.
Reaction temperature, reaction time of the step of converting a part of the organic silver salt to silver halide using the silver halide forming component,
Various conditions such as the reaction pressure can be appropriately set according to the purpose of the production, but the reaction temperature is usually -23 ° C to 74 ° C.
C., the reaction time is 0.1 second to 72 hours, and the reaction pressure is preferably set to the atmospheric pressure. This reaction is also preferably performed in the presence of the polymer used as the binder. The amount of the polymer used at this time is 0.01 to 100 parts by mass, preferably 0.1 to 10 parts by mass per 1 part by mass of the organic silver salt.

The photosensitive silver halide prepared by the various methods described above includes, for example, sulfur-containing compounds, gold compounds,
Platinum compounds, palladium compounds, silver compounds, tin compounds,
Chemical sensitization can be performed by a chromium compound or a combination thereof. The method and procedure of the chemical sensitization are described in, for example, U.S. Pat. No. 4,036,650, British Patent No. 1,518,850, and JP-A-51-22430.
And Nos. 51-78319 and 51-81124. Also, when a part of the organic silver salt is converted to a photosensitive silver halide by a silver halide forming component, as described in U.S. Pat. An amide compound having a molecular weight may coexist.

In addition, these photosensitive silver halides may be used in order to prevent illuminance failure and to adjust the gradation.
Metals belonging to Group 0, such as Rh, Ru, Re, Ir, O
An ion such as s or Fe, a complex thereof or a complex ion can be contained. It is particularly preferable to contain ions or complex ions of metals belonging to Groups 6 to 10 of the periodic table. As the above metals, W, Fe, Co, Ni,
Cu, Ru, Rh, Pd, Re, Os, Ir, Pt, A
u is preferred and these metals can be incorporated into the silver halide in complex form.

The content of metal ions or complex ions is generally 1 × 10 ⁻⁹ per mol of silver halide.
~ 1 × 10 ^-2 mol is suitable, preferably 1 × 10 ^-8 mol.
１1 × 10 ^-4 mol. The compound that provides the ion or complex ion of these metals is preferably added during silver halide grain formation and incorporated into the silver halide grains. Preparation of silver halide grains, that is, nucleation, growth, and physical ripening It may be added at any stage before and after chemical sensitization, but is particularly preferably added at the stage of nucleation, growth, and physical ripening, more preferably at the stage of nucleation and growth. Preferably, it is added at the stage of nucleation.
In the addition, it may be added in several portions, may be added uniformly in the silver halide grains, or may be added to the silver halide grains as described in JP-A-63-29603 and JP-A-2-3062.
No. 36, No. 3-167545, No. 4-76534,
As described in JP-A-6-110146, JP-A-5-273683, and the like, the particles can be contained in the particles with a distribution. It is preferable to have a distribution inside the particles. These metal compounds can be prepared from water or a suitable organic solvent (eg, alcohols, ethers, glycols,
Ketones, esters, amides, etc.). For example, an aqueous solution of a powder of a metal compound or an aqueous solution of a metal compound and NaCl or KCl dissolved together may be added to the aqueous solution during particle formation. A silver halide grain is prepared by adding it to a silver salt solution or a water-soluble halide solution, or adding it as a third aqueous solution when the silver salt solution and the halide solution are mixed at the same time, and simultaneously mixing the three solutions. 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 another silver halide grain doped with metal ions or complex ions in advance during silver halide preparation is added. There is a method of dissolving.
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.

(Spectral Sensitizing Dye) The spectral sensitizing dye used in the present invention may be optionally used, for example, as described in JP-A-63-159814.
No., 60-140335, 63-231437
No., 63-259,651 and 63-304242
No. 63-15245, U.S. Pat. No. 4,639,4
No. 14, No. 4,740,455, No. 4,741,
No. 966, No. 4,751,175, No. 4,83
Sensitizing dyes described in US Pat. No. 5,096 can be used. Useful sensitizing dyes for use in the present invention include, for example,
ch Disclosure Item17643IV-
Item A (p.23, December 1978), Item 183
It is described in the literature described or cited in section 1X (p. 437, August 1978). 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-9-34078
And compounds described in JP-A Nos. 9-54409 and 9-80679 are preferably used.

(Hydrazine Compound) The photosensitive layer of the heat-developable material of the present invention or a layer adjacent to the photosensitive layer preferably contains a hydrazine compound as a high contrast agent for enhancing the contrast of a silver image. Examples of the hydrazine compound include columns 11 and 2 of US Pat. No. 5,545,505.
Compounds H-1 to H-29 described in US Pat.
Compounds 1 to 1 described in columns 9 to 11 of No. 64,738
The compounds described in No. 2 are preferably used. These hydrazine compounds can be synthesized by a known method.

The above-mentioned hydrazine compound is added to the photosensitive layer and / or the layer adjacent to the photosensitive layer, and the amount of the hydrazine compound depends on the particle size of silver halide grains, the halogen composition, the degree of chemical sensitization, the type of inhibitor, and the like. However, the range is usually about 10 ^-6 to 10 ^-1 mol, preferably 10 ^-5 to 10 ^-2 mol, per mol of silver halide.

(Binder) As the polymer binder used in the photosensitive layer or the non-photosensitive layer of the heat-developable material of the present invention, a material which is preferred as a place where silver halide, organic silver salt and reducing agent react, A material that is preferable for a reaction in which the color dye is decolorized by heat of 80 to 200 ° C. or lower, or a material that allows the base generating precursor compound to quickly generate a base by heat is selected. Examples of the polymer binder include alcohols such as methanol and ethanol, ketones such as methyl ethyl ketone and acetone, polymers used by dissolving in polar solvents including dimethyl sulfoxide and dimethylformamide, and water-dispersed polymers. As the polymer binder of the heat developing material of the present invention, an aqueous dispersion polymer is preferable. Further, with respect to a preferred polymer composition, the glass transition point is more preferably from -20 ° C to 80 ° C, particularly preferably from -5 ° C to 60 ° C. If the glass transition point is high, the temperature for thermal development is high, and if the glass transition point is low, fogging is likely to occur, resulting in a decrease in sensitivity and softness.

Examples of the polymer dissolved in the above-mentioned polar solvent and the like include cellulose derivatives such as hydroxyethylcellulose, carboxymethylcellulose, methylcellulose and ethylcellulose, starch and its derivatives, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl butyral, and polyacrylic acid. Sodium, polyethylene oxide, acrylamide-acrylate copolymer, styrene-maleic anhydride copolymer, polyacrylamide, sodium alginate,
Gelatin, casein, polystyrene, polyvinyl acetate,
Examples thereof include polyurethane, polyacrylic acid, polyacrylate, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, vinyl chloride-vinyl acetate copolymer, and styrene-butadiene-acryl copolymer. After drying, after forming a film, those having a low equilibrium water content of the coating film are preferred, and particularly those having a low water content include, for example, cellulose acetate, cellulose acetate butyrate, and poly (methyl methacrylic acid). Acrylates), poly (acrylic acid), poly (methacrylic acid), poly (vinyl chloride), copoly (styrene-maleic anhydride), copoly (styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl) Acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethanes), phenoxy resins, poly (vinylidene chloride), poly (epoxides),
Poly (carbonate) s, poly (vinyl acetate),
Examples include cellulose esters and poly (amide) s.

As the above-mentioned water-dispersed polymer, it is preferable to use fine particles having an average particle diameter in the range of 1 nm to several μm and dispersed in an aqueous dispersion medium. Water-dispersed polymers are widely used as binders for water-based coatings, and among them, latex is particularly preferred in that it can improve water resistance. The amount of latex used for the purpose of obtaining water resistance as a binder is determined in consideration of coatability, but is preferably as large as possible from the viewpoint of moisture resistance, and is usually 50 to 100% by mass, and 80 to 100% by mass based on all binders. % Is preferred.

(Dye used in AI layer or BC layer) In the heat-developable material of the present invention, a BC for preventing halation is used.
When a layer and / or an AI layer for preventing irradiation are provided, the dye used in the AI layer and the BC layer may be any dye that absorbs image exposure light, and is particularly preferably the heat decolorizable dye. Is mentioned. Further, heat-decolorable dyes described in U.S. Pat. No. 5,384,237 and the like can also be mentioned as preferable dyes. If the dye used is not heat-decolorable, the amount used is limited to a range that does not cause image damage to the heat-developable material. If the heat-decolorable dye is used, a necessary and sufficient amount of the dye is added. be able to.

(Color Toning Agent) It is preferable to add a color toning agent to the heat-developable material of the present invention. Examples of suitable toning agents are Re
Search Disclosure No. 17029, which includes the following: Imides (for example,
Phthalimide); cyclic imides, pyrazolin-5-ones, and quinazolinones (for example, succinimide, 3-
Phenyl-2-pyrazolin-5-one, 1-phenylurazole, quinazoline and 2,4-thiazolidinedione); naphthalimides (for example, N-hydroxy-
1,8-naphthalimide); cobalt complex (for example,
Hexamine trifluoroacetate of cobalt), mercaptans (eg, 3-mercapto-1,2,4-triazole); N- (aminomethyl) aryldicarboximides (eg, N- (dimethylaminomethyl)
Phthalimides); combinations of blocked pyrazoles, isothiuronium derivatives and certain photobleaches (e.g., 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-polyhalomethane compound dione); a combination of phthalazinone and a sulfinic acid derivative (for example, 6-chlorophthalazinone + benzenesulfin) A combination of a polyhalomethane compound and phthalic acid; a polyhalomethane compound (including an adduct of the polyhalomethane compound) and maleic anhydride, and phthalic acid, 2,3-naphthalenedicarboxylic acid or o-phenylene acid derivative and its anhydride (For example, a combination with at least one compound selected from phthalic acid, 4-methylphthalic acid, 4-nitrophthalic acid and tetrachlorophthalic anhydride; quinazolinediones;
Benzoxazine, naloxazine derivatives; benzoxazine-2,4-diones (eg, 1,3-benzoxazine-2,4-dione); pyrimidines and asymmetric compounds
Triazines (eg, 2,4-dihydroxypyrimidine) and tetraazapentalene derivatives (eg, 3,
6-dimercapto-1,4-diphenyl-1H, 4H-
2,3a, 5,6a-tetraazapentalene).

(Matting agent) The matting agent may be either an organic or inorganic substance. Examples of the inorganic matting agent include silica described in Swiss Patent No. 330,158, and French Patent No. 1,296,995. And alkaline earth metals or carbonates such as cadmium and zinc described in British Patent No. 1,173,181. Examples of organic matting agents include starch described in US Pat. No. 2,322,037 and Belgian Patent No. 6
No. 25,451, British Patent No. 981,198, etc., starch derivatives, polyvinyl alcohol described in JP-B-44-3643, polystyrene or polymethacrylate described in Swiss Patent No. 330,158, U.S. Pat. Polyacrylonitrile described in 3,079,257 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 sphere. 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 has an average particle size of 0.5 to 1
0 μm, more preferably 1.0 to
It is 8.0 μm. The matting agent has a monodispersity of 50 or less, more preferably 40 or less, and particularly preferably 20 or less. here,
The monodispersity of the particles is represented by a number obtained by dividing the standard deviation of the particle size by the average value of the particle size and multiplying by 100. The method for adding the matting agent according to the present invention may be a method in which the matting agent is dispersed in a coating liquid in advance, or a method in which the coating liquid is applied and then the matting agent is sprayed before drying is completed. You may.
When a plurality of types of matting agents are added, both methods may be used in combination.

(Support) As the support, paper, synthetic paper,
A support such as a nonwoven fabric, a metal foil, or a plastic film can be used, and a composite sheet combining these may be used arbitrarily.

(Image Exposure) In the image exposure for forming an image on the heat-developable material of the present invention, for example, the light emission wavelength is 660 n.
m, 670 nm, 780 nm, 810 nm, 830 nm
It is preferable to use a laser scanning exposure device in which the angle between the exposed surface of the heat developing material and the scanning laser beam does not become substantially perpendicular. Here, the phrase “there is no substantial vertical” means that the laser scanning angle is preferably 55 to 88.
Degrees, more preferably 60 to 86 degrees, still more preferably 65 degrees
About 84 degrees, most preferably 70 to 82 degrees. The beam spot diameter on the exposed surface of the photothermographic material when the laser beam is scanned on the photothermographic material is preferably 200 μm or less, more preferably 100 μm or less. This is preferable because the smaller the spot diameter is, the more the angle of deviation of the laser incident angle from the perpendicular can be reduced. Note that the lower limit of the beam spot diameter is preferably 10 μm.
By performing such laser scanning exposure, it is possible to reduce image quality deterioration related to reflected light such as occurrence of interference fringe-like unevenness.

The exposure in the present invention is also preferably performed using a laser scanning exposure machine that emits a scanning laser beam that is a vertical multi. By using vertical multi-mode laser exposure, image quality deterioration such as occurrence of interference fringe-like unevenness is reduced as compared with vertical single-mode scanning laser light. In addition to the above-described method, there is a method of vertical multiplexing, such as combining, using return light, or applying high frequency superposition. In addition, the vertical multi means that the exposure wavelength is not single, and the distribution of the exposure wavelength is usually 5 nm or more, preferably 10 nm or more.
nm or more. The upper limit of the exposure wavelength distribution is not particularly limited, but is usually about 60 nm.

(Developing Method) The developing method used in the present invention will be described below.

<Heat Roller or Heat Drum>
Heat roller used in the heat development section of a developing machine that develops image materials
-Has heat resistance, chemical resistance, abrasion resistance, antistatic properties, etc.
Any roller provided can be employed, but especially
Silicone rubber with improved heat and chemical resistance
(Risiloxane) rollers are preferred. silicone rubber
Is colored by adding various colorants as necessary.
Have been. Typical coloring to give black color to silicone rubber
As the agent, carbon black or black red iron (Fe_ThreeO_Four)
It has been known. Add various additives to improve heat resistance
Giving is also done. Such silicone rubber
As a method of imparting heat resistance to the composition, generally, a
A platinum catalyst is typical as a promoter, and a platinum catalyst and
Combinations with additives such as carbon black have also been proposed.
I have. For example, US Pat. No. 3,652,488
Bon Black is also disclosed in U.S. Pat. No. 3,635,874.
Mentions titanium oxide as an auxiliary agent. In Japan
Iron oxide (FeO) in Japanese Patent Publication No. 51-24302_x(Fe_Two
O _Three)_yIs used.
Gala (Fe_ThreeO_Four) Is black and has excellent thermal conductivity
Are preferred.

However, the color of the iron oxides such as the black iron oxide changes from black to red due to an oxidation-reduction reaction between the reducing agent and the oxidizing agent of the heat developing material.
There is a problem that heat resistance tends to decrease. In the present invention, when the metal oxide added to the silicone rubber roller is an iron oxide, it is preferable that the surface thereof is subjected to a treatment for preventing deterioration.

Preferred examples of the components for producing a silicone rubber roller as a heat roller are shown below.

(A) Organopolysiloxane 1 in which a part of silicon atoms may be substituted by a heteroatom having 1 to 30 carbon atoms
100 parts by mass, (B) 10 to 100 parts by mass of a filler, (C) 0.1 to 10 parts by mass of a curing agent, and (D) iron oxides subjected to a surface treatment for preventing deterioration. 1 to 50 parts by weight are added.

Hereinafter, the above (A), (B), (C) and (D) will be described in more detail. The organopolysiloxane of the component (A) for producing the silicone rubber roller used in the present invention has a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms at the silicon atom of the organopolysiloxane. Examples of the monovalent hydrocarbon group include an alkyl group, an alkenyl group, and an aryl group. Further, as a substituent that the monovalent hydrocarbon group may have, for example, a methyl group, a vinyl group, or a phenyl group A monovalent group selected from the above is preferred. The alkenyl group is 0.01 to 5
Molar%, particularly preferably 0.02 to 0.5 mole%. Further, the monovalent hydrocarbon group may be one in which part or all of the hydrogen atoms bonded to carbon atoms such as an alkyl group, an alkenyl group, and an aryl group are substituted with a halogen atom, a cyano group, or the like. , For example 3,
Examples thereof include a 3,3-trifluoropropyl group and a 2-cyanoethyl group, and a 3,3,3-trifluoropropyl group is particularly preferable. Examples of the both terminal groups of the molecular chain of the organopolysiloxane include a hydroxy group, a trimethylsilyl group, a dimethylvinylsilyl group, and a trivinylsilyl group, but are not particularly limited thereto. (A)
The component organopolysiloxane has a polymerization degree of preferably 2,700 or more, more preferably 3,000 to 20,000, and particularly preferably 4,800 to 10,000, in order to obtain sufficient mechanical strength. It is. The organopolysiloxane of the component (A) has a different structure and a different degree of polymerization.
More than one species may be used in combination.

The filler of the component (B) is used to reinforce silicone rubber, and examples thereof include silica, alumina, titanium oxide, magnetite, hematite, and black red iron oxide. Particularly preferred is silica. to improve the mechanical strength of and such that tensile strength gives the hardness of moderate to silicone rubber, the specific surface area having its but preferably used is not less than ^{66m 2 / g, 99m 2 ~444m} 2 / g are particularly preferred. As such reinforcing silica, specifically, fumed silica, calcined silica, precipitated silica, or the like is used alone or in combination of two or more. These silicas may be surface-treated with a linear organopolysiloxane, a cyclic organopolysiloxane, hexamethyldisilazane, dichlorodimethylsilane, or the like. (B)
The compounding amount of the component is the organopolysiloxane 1 of the component (A).
It is usually from 10 to 100 parts by mass, preferably from 20 to 50 parts by mass, per 100 parts by mass. If the compounding amount is out of this range, the processability of the silicone rubber composition may be deteriorated, or sufficient mechanical strength may not be obtained.

The curing agent of the component (C) cures the composition of the present invention to form a silicone rubber, and generally uses an organic peroxide. When the organopolysiloxane of the component (A) contains two or more alkenyl groups in the molecule, a combination of an organohydrogenpolysiloxane and a platinum-based catalyst can be used as a curing agent. The amount of the curing agent may be an amount sufficient to cure the composition of the present invention as described below. In addition, (A)
When the organopolysiloxane of the component contains two or more alkenyl groups in the molecule, the organohydrogenpolysiloxane that can be used as a curing agent includes methylhydrogenpolysiloxane having trimethylsiloxy groups at both ends and trimethylsiloxy at both ends. Group-blocked dimethylsiloxane / methylhydrogensiloxane copolymer,
Examples thereof include a dimethylsiloxane-methylhydrogensiloxane copolymer having both ends methylhydrogensiloxy groups blocked. On the other hand, platinum-based catalysts include chloroplatinic acid,
Examples thereof include an alcohol solution of chloroplatinic acid and a complex of chloroplatinic acid and divinyltetramethylsiloxane. In general, the compounding amount of the above-mentioned organohydrogenpolysiloxane is such that the ratio of the number of moles of hydrogen atoms bonded to silicon atoms contained in the organohydrogenpolysiloxane to the number of moles of alkenyl groups in the component (A) is ( 0.5: 1)
The amount of the platinum-based catalyst is generally 0.1 to 3,000 ppm in terms of platinum, based on the mass of the component (A). When using, it can be shared.

Next, iron oxides which have been subjected to a surface treatment for preventing deterioration as component (D) are preferred components of the silicone composition, and include alumina, silica, silica-alumina, titanium oxide, tin oxide and the like. Magnetite surface treatment with metal oxide of which is prevented from alteration, hematite, iron oxides such as black red iron oxide, or manganese, antimony, tin, magnetite which has been subjected to alteration prevention treatment by doping a metal such as zinc, Iron oxides such as hematite and black bengal are contained in an amount of 0.1 to 50% by mass.

The method for producing the silicone rubber composition is not particularly limited, but the components (A) and (B) are charged into a kneading device such as a kneader and blended at room temperature.
A method in which heat treatment is performed at a temperature of 200 ° C. for 30 minutes to 5 hours, and then the component (D) is added and kneaded with a roller mill, a Banbury mixer, or the like can be employed. After that, the component (C) may be added and heat-cured by a known method.
The cured silicone rubber thus obtained has good heat resistance and chemical resistance.

<Heat Developing Apparatus> FIG. 1 is a cross-sectional view showing a main part of an example of a heat developing apparatus for explaining a developing method used in the present invention. It is preferably introduced with the emulsion layer side down to the developing unit 7 by the carry-in roller 2, heated and transported by the developing unit 7 (inside the heat insulating cover), developed, and discharged by the discharge roller 4. The developing unit 7 has a heat source 3 such as a far-infrared heater or a nichrome wire heater, and has a heat drum 5 rotating in the direction of an arrow, and a plurality of heat rollers on the outer periphery rotating in synchronization with the heat drum 5. 6 and is conveyed. Reference numeral 8 denotes a heat insulating cover, and the rear surface of the heat insulating cover 8 is a cold mirror that reflects heat.
It is preferable to provide a preheating means (not shown) before introducing the heat developing material 1 into the developing unit 7 and a cooling means (not shown) after developing the heat developing material 1.

Here, the heat drum 5 is made of copper, aluminum,
A material having excellent thermal conductivity such as steel is used, and the plurality of heat roller groups 6 are preferably a silicone roller containing the above-described filler, and the surface hardness of the heat roller is expressed by a value represented by an elastic modulus. The pressure is preferably set to 1 × 10 ^{−4 to} 1 Pa. The transport speed of the heat developing material 1 is 1 to 100.
cm / sec.
It is preferable to carry out development by heating and conveying for 100 sec, and the pressure between the heat drum 5 and the heat roller group 6 during conveyance is preferably set to 10 ² to 10 ⁵ Pa. In the above description, the heat roller group 6 is not provided with a heat source, and the heat roller group 6 is pressed against the heat drum 5 having a built-in heat source and the heat is heated by heat reflection of a cold mirror on the inner surface of the heat insulating cover 8 to perform development. Although an example of performing the process is described, in the developing method of the present invention, the heat roller group 6 may be provided with a heat source for development.

[0100]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the embodiments of the present invention are not limited thereto.

Example 1 <Preparation of Subbed Support> A polyethylene terephthalate support having a thickness of 175 μm was subjected to a corona discharge treatment of 8 W / m ² · min on both sides, and the following coating liquid 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, and the undercoat coating solution b-
1 was applied so as to have a dry film thickness of 0.8 μm, and dried to form an undercoat layer B-1.

<< Undercoating Coating Solution a-1 >> Copolymer of butyl acrylate (30% by mass), t-butyl acrylate (20% by mass), styrene (25% by mass), and 2-hydroxyethyl acrylate (25% by mass) Combined latex liquid (solid content 30%) 270 g Finished to 1 liter with water.

<< Undercoat Coating Solution b-1 >> A copolymer latex solution of butyl acrylate (40% by mass), styrene (20% by mass) and glycidyl acrylate (40% by mass) (solid content: 30%) 270 g with water Finish to 1 liter.

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 described below is coated and dried on the lower layer A-1 so as to have a dry film thickness of 0.1 μm. To provide an undercoating upper layer A-2, and on the undercoating layer B-1, the following undercoating upper layer coating solution b-2
Was applied to a dry film thickness of 0.8 μm and dried to form an undercoating upper layer B-2 having an antistatic function.

<< Coating Solution for Undercoating Layer a-2 >> Gelatin 0.4 g / m ² Mass of Silica Particles (Average Particle Size 3 μm) 0.1 g Finishing to 1 L with Water << Coating Solution for Undercoating Layer b-2 >> Styrene butadiene copolymer latex liquid (solid content: 20%) 80 g Polyethylene glycol (number average molecular weight: 600) 6 g Finished to 1 liter with water.

<Preparation of silver halide grain emulsion A>
After dissolving 7.5 g of inert gelatin and 10 mg of potassium bromide in 0 ml and adjusting the temperature to 35 ° C. and the pH to 3.0, 370 ml of an aqueous solution containing 74 g of silver nitrate and (98 /
An aqueous solution containing potassium bromide and potassium iodide in the molar ratio of 2) was added over 10 minutes by a controlled double jet method while maintaining the pAg at 7.7. Thereafter, 0.3 g of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene was added, the pH was adjusted to 5 with NaOH, the average particle size was 0.06 μm, and the variation coefficient of the projected diameter area was 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 thereto.
After adjusting the pAg to 5.9 and pAg 7.5, a silver halide grain emulsion A was obtained.

<Preparation of water-dispersed organic silver salt> 111.4 g of behenic acid and 83.8 of arachidic acid were added to 4720 ml of pure water.
g and 54.9 g of stearic acid were dissolved at 80 ° C. Next, while stirring at a high speed, 540.2 ml of a 1.5 mol / L aqueous sodium hydroxide solution was added, 6.9 ml of concentrated nitric acid was added, and the mixture was cooled to 55 ° C. to obtain a sodium organic acid solution.
While maintaining the temperature of the above-mentioned organic acid sodium acid solution at 55 ° C., the silver halide grain emulsion A (containing 0.038 mol of silver) and 450 ml of pure water were added and stirred for 5 minutes. Next, 760.6 ml of a 1 mol / L silver nitrate solution was added over 2 minutes, the mixture was further stirred for 20 minutes, and water-soluble salts were removed by filtration. Thereafter, washing with deionized water and filtration were repeated until the conductivity of the filtrate reached 2 μS / cm, and then water was added to make up to 1 L.

<Coating of Photosensitive Layer and BC Layer> The following layers were sequentially formed on the support provided with the undercoat layer to prepare a sample. The drying was performed at 45 ° C. for 1 minute.

<< Coating on the BC Layer Side >> On the back surface side (on the undercoating upper layer B-2), a coating solution prepared by adding the following aqueous solution or aqueous dispersion of the phosphazene compound to water is added as follows. The resultant was applied and dried to form a BC layer.

<< Coating of BC Layer >> Inert gelatin 1.8 g / m ² Phosphazene compound of the present invention (described in Table 1) 1.4 × 10 ⁻⁴ equivalent / m ² Dye: C1 1.2 × 10 ⁻⁵ mol / m ² surfactant: N- propyl-octyl-sulfonamide acetate 0.02 g / m ² dihexyl sulfosuccinate sodium salt 0.02 g / m ² hardener: 1,2-bis (vinyl sulfonamido) ethane 0.02 g / m ² << Coating of BC protective layer >> Inert gelatin 1.1 g / m ² Hardener: 1,2-bis (vinylsulfonamide) ethane 0.01 g / m ² Surfactant: N-propylperfluorooctylsulfonamide Acetic acid 0.02 g / m ² Matting agent (PMMA: average particle diameter 5 μm) 0.12 g / m ² Phosphazene compound of the present invention (described in Table 1) 1.3 × 10 ^-3 equivalents / m ² << Coating on photosensitive layer side 》 《 On the application "lower pulling layer A-2 of the I layer, to form an AI layer by coating and drying the following coating solution so that the amount per below.

Binder: PVB-1 0.4 g / m ² Dye: C1 1.0 × 10 ⁻⁵ mol / m ² << Coating of photosensitive layer >> For forming the photosensitive layer, water was added to an aqueous dispersion of the following composition. Was added to prepare a coating solution. Apply this coating solution to 35
The silver potential was measured using a silver electrometer formed from a reference electrode composed of an Ag / AgCl electrode in a 3 mol / L solution through a salt bridge composed of a silver electrode and a 10% KNO ₃ salt solution, while keeping the temperature at around 0 ° C. After that, it was applied and dried on the AI layer so that the following amount was obtained. The aqueous dispersion of the prepared organic silver salt was mixed with a polymer binder in an amount of 1.4 g / m ² in terms of silver.

Binder: PVB-1 2.6 g / m ² Phosphazene compound of the present invention (described in Table 1) 3.2 × 10 ⁻⁴ equivalent / m ² Spectral sensitizing dye: A1 2 × 10 ⁻⁵ mol / m ² antifoggants -1: pyridinium hydrobromide perbromide 0.3 mg / m ² antifoggant -2: isothiazolone 1.2 mg / m ² reducing agent: pH of a-4 3.3 mmol / m ² photosensitive layer coating solution Was adjusted to 5.6.

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

Inert gelatin 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 1,2- (bisvinylsulfone acetamide) ethane 0.3 g / m ² Diethyl sulfosuccinate sodium salt 0.02 g / m ² The phosphazene compound of the present invention (described in Table 1) 2 × 10 ^-4 equivalents / m ²

[0115]

Embedded image

In the manner described above, a sample of the heat developing material was prepared (in the preparation of the sample, the photosensitive layer, the surface protective layer, the BC layer,
The same phosphazene compound was used in the same sample as the type of phosphazene compound in each layer of the BC protective layer. << Evaluation Method >><Fog, Sensitivity, Storage Property> The heat-developable material sample prepared above was divided into two, and one of them was stored at 25 ° C. in an atmosphere of 60% RH for 3 days, and then a 810 nm semiconductor laser was used. Exposure was performed with a photometer for exposure, and after exposure, heating was performed at 120 ° C. for 8 seconds (contact with a heat drum on the BC side) using the thermal developing apparatus in FIG. 1, and the obtained sample was used as a normal humidity sample. Another is 35 ° C, 78
After storing for 3 days in a high humidity atmosphere of% RH, a sample obtained by exposure and development in the same manner as a normal humidity sample was used as a high humidity sample.
The laser exposure and development processing of the above normal humidity sample is 25
The test was performed in a room conditioned at a temperature of ± 1 ° C and a relative humidity of 54% ± 1%.

The sensitivity and fog of the above normal humidity sample and high humidity sample were measured by a densitometer. The sensitivity is evaluated by the reciprocal of the ratio of the exposure amount that gives a density 0.3 higher than the fog density. The sensitivity is expressed by relative evaluation using the sample 101 as a reference (100). And the difference in sensitivity. The smaller the increase in fog and the decrease in sensitivity, the better the storage stability.

<Scratch resistance> The scratch resistance was determined by subjecting a sample subjected to a scratch resistance tester capable of rubbing with a nylon brush while applying a pressure change of 0 to 10 kPa to the surface of the heat-developable material to heat development. And the weight at which scratches were made (the weight at which scratches started) were measured. The larger the weight value at which the scratch is made, the better the scratch resistance.

<Dirt> Dirt can be removed by placing a 2.5 cm diameter silicone rubber heat roller (without a heat source) around a 12 cm diameter heat drum and applying a load of 3 kPa.
Using a test developing device that develops at 0 ° C., 20 × 30 c
When samples of m size were successively heated and developed by 200 sheets, stains of various samples were evaluated. Here, the level with the least amount of dirt was set to rank 5.0, the level with the most dirt was set to 1.0, and the level where practically no problem occurred even with a small amount of dirt was set to 3.0.

Table 1 shows the above results.

[0121]

[Table 1]

As shown in Table 1, the samples containing the phosphazene compound of the present invention showed that the samples were resistant to scratches during thermal development, stains on the samples,
It can be seen that the photographic performance (sensitivity and fog characteristics) of the normal humidity sample and the high humidity sample are excellent.

Example 2 A sample was prepared in the same manner as in Example 1 except that the polyhalomethane compound was added to the photosensitive layer or the protective layer of the photosensitive layer as described below.

That is, (A) In the case of adding only to the photosensitive layer,
In the case of adding 3.6 × 10 ^-4 mol / silver 1 mol and (b) adding only to the protective layer, the amount added per 1 mol of silver in the photosensitive layer is increased by 20% from the weight per unit area. Was added.
(C) When adding to both the protective layer and the photosensitive layer of the photosensitive layer, the addition amount per unit area of the protective layer and the photosensitive layer of the photosensitive layer was set to 2: 3. The same polyhalomethane compound was used in the same sample.

<Evaluation Method><Print-outfog> A 1000 lux fluorescent lamp was added to the developed sample obtained by thermally developing the above-prepared heat-developable material sample in the same manner as in the normal humidity sample of Example 1. (Note that a diffusion sheet was interposed between the fluorescent lamp and the test sample so that light irradiation was uniform). The irradiation time was changed. Here, the value of the increase in fog after irradiation for 3 hours was defined as burn-out fog.

<Residual Color> For the residual color, a developed sample obtained by heat development in the same manner as in the normal humidity sample of Example 1 was visually evaluated on a 5-point scale. Rank 5 was the best level without residual color, rank 1 was the worst level, and rank 3 was a level that was practically acceptable.

The scratch resistance was evaluated in the same manner as in Example 1. Table 2 shows the above results.

[0128]

[Table 2]

Table 2 shows that the use of the phosphazene compound and the polyhalomethane compound of the present invention is excellent in printout fog, heat resistance and residual color during thermal development.

Example 3 A heat-decolorizable dye and a base-generating precursor compound were added to a BC layer, AI
A sample was prepared in the same manner as in Example 1 except that the following amounts were added to the layer and the photosensitive layer (however, the dye C1 was not added to the BC layer and the AI layer). BC layer: Thermal decolorable dye 3.6 × 10 ⁻⁵ mol / m ² Base generating precursor compound 3.6 × 10 ⁻⁵ mol / m ² AI layer: Thermal decolorizable dye 1.2 × 10 ⁻⁵ Mol / m ² base-generating precursor compound 1.2 × 10 ⁻⁵ mol / m ² Photosensitive layer: thermal decolorable dye 2.1 × 10 ⁻⁴ mol / m ² base-generating precursor compound 2.1 × 10 ^{− 4} mol / m ² << Evaluation method >><Print-outfog> Evaluation was performed in the same manner as in Example 2.

<Remaining Color> Evaluation was performed in the same manner as in Example 2.

<Sharpness> As for sharpness, a chart having a sinusoidal transmittance distribution was prepared and tested for the obtained coated sample, and the modulation transfer function (MTF) was measured at a spatial frequency of 50%. The modulation transmission in cycles / mm is determined and indicated as sharpness.

The burn-out fog and residual color were evaluated in the same manner as in Example 2. Table 3 shows the above results.

[0134]

[Table 3]

Table 3 shows that the phosphazene compound of the present invention
It can be seen that the use of the heat-decolorable dye and the base-generating precursor compound is excellent in print-out fog, sharpness, and residual color. Further, it can be seen that the use of a polyhalomethane compound has an effect of suppressing burn-out fog.

[0136]

According to the present invention, firstly, it is excellent in scratch resistance at the time of development, less likely to cause stains by the developing means, stability of photographic performance at the time of storage, and high image quality after development. A heat-developable material having excellent moisture storage stability can be provided. Second
Can provide a heat-developable material in which fogging due to silver after development is suppressed. Thirdly, it is possible to provide a heat-developable material in which the dye for improving sharpness has excellent heat decoloring properties, has less residual color after development, and thus has a stable color tone of an obtained image.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing an example of a heat developing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thermal developing material 2 Carry-in roller 3 Heat source 4 Discharge roller 5 Heat drum 6 Heat roller group 7 Developing part 8 Heat insulation cover

Claims (4)

[Claims] 1. A photosensitive layer containing photosensitive silver halide grains, an organic silver salt, a reducing agent and a binder on a support, a layer adjacent to the photosensitive layer, and a support opposite to the photosensitive layer. A heat developing material having a backing layer and a backing protective layer on a body, wherein at least one of the layers contains a phosphazene compound. 2. The heat developing material according to claim 1, wherein the phosphazene compound is a compound represented by the following general formula (1). Embedded image (Wherein, R ¹ , R ² , R ³ and R ⁴ each have a halogen atom, an aromatic group, a heterocyclic group, a hydroxy group, a substituted oxy group, an amino group, a substituted amino group, Represents an alkyl group, an alkenyl group or an alkynyl group having ¹ to 60 carbon atoms, wherein R ¹ , R ² , R ³ and R ⁴ are
Each may be different or the same. n is 3 to 100,0
Represents an integer of 00. R ³ and R ⁴ may combine with each other to form a ring. ) 3. The heat developing material according to claim 1, wherein the photosensitive layer or a layer adjacent to the photosensitive layer contains a polyhalomethane compound. 4. The photosensitive layer, a layer adjacent to the photosensitive layer, a backing layer and at least one layer selected from a backing protective layer, wherein at least one selected from a heat-decolorable dye and a base-generating precursor compound is contained. 4. The heat-developable material according to claim 1, wherein the heat-developable material is contained.