JPS62136645A - Heat developable photosensitive material - Google Patents

Abstract

PURPOSE:To obtain a heat developable photosensitive material having an excellent green shelf life by incorporating a heat solvent having the m.p. of a specific value or above in the form of solid particles into the heat developable photosensitive material. CONSTITUTION:The heat solvent is a compd. having >=130 deg.C, more preferably 130-200 deg.C m.p. and is solid at an ordinary temp. A compd. which exhibits the characteristic of the ratio between the inorg. and org. characteristics ranging 0.5-3.0, more preferably 0.7-2.5, further preferably 1.0-2.0 is useful. The more particularly preferable heat solvent is the compd. expressed by the formula. This developable photosensitive material is color-developed simply by heating the same for 1-180sec, more preferably 1.5-120sec usually in a 80-200 deg.C, more preferably 120-170 deg.C temp. range after imagewise exposing as it is. The heat developable photosensitive material having the excellent green shelf life is thus obtd.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a photographic light-sensitive material that forms an image by heat development, and more specifically relates to storage stability (
This relates to the improvement of shelf life (hereinafter referred to as raw shelf life).

[Conventional technology]

A method in which the development step for obtaining an image is performed by dry heat treatment has many advantages over the conventional wet method in terms of processing time, cost, and concerns about pollution.

For heat-developable photosensitive materials in which the second development step can be carried out by dry heat treatment, for example, Japanese Patent Publication Nos. 43-4921 and 1983
This is described in Japanese Patent No. 3-4924, which discloses a black-and-white photothermographic material comprising a silver salt, a silver halide, and a reducing agent.

Attempts have also been made to improve such heat-developable photosensitive materials and obtain color images by various methods.

For example, JP-A-57-179840, JP-A No. 57-186
Fuii No. 57-198458, No. 57-2072
No. 50-, No. 5g-40551, No. 5g-58543
No. 5g-79247, No. 59-12431,
No. 59-22049, No. 59-68730, No. 59
-124339, 59-124333, 59-
No. 124331, No. 59-159159, No. 59-1
No. 81345, No. 59-159161, No. 58-11
No. 6537, No. 58-123533, No. 58-149
There are No. 046 and No. 58-14947.

The basic structure of a color type photothermographic material that produces this color image consists of a photosensitive element and an image receiving element. It consists of a photosensitive silver halide, a reducing agent, a dye-providing substance, and a binder. In the present invention, only the photosensitive element is referred to as a heat-developable photosensitive material in a narrow sense.

In the former black and white type, optical information is imparted to the photosensitive silver halide through image exposure, and during thermal development,
The photosensitive silver halide in the photosensitive layer and the reducing agent present in the vicinity of the exposed photosensitive silver halide cause an oxidation-reduction reaction to produce silver, and the exposed areas of the photosensitive layer turn black. A silver image is formed.

In addition, in the color type, optical information is given to the photosensitive silver halide by image exposure, and in heat development,
Under the action of a reducing agent, dissolution physical development according to optical information was performed between an organic silver salt and a photosensitive silver halide.
Alternatively, the dye that forms the image is released or formed by the reaction of the reducing agent that has not acted with the dye-providing substance.

The image-forming dye obtained by thermal development is transferred to an image-receiving element to form an image.

It is known that in the development process or transfer process, the development and transfer can be accelerated by adding a so-called hot solvent. For example, JP-A No. 59-84236 discloses sulfamide y derivatives, JP-A No. 60-14241 discloses a thermal solvent supply layer, and JP-A No. 59-68730 and Japanese Patent Application No. 59-47787 disclose polyhydric alcohols. ing.

However, it has been revealed that when these thermal solvents are used, although the development and transfer characteristics are improved, the raw storage stability of the photothermographic materials containing the thermal solvents is decreased.

c.Object of the present invention] Accordingly, an object of the present invention is to provide a heat-developable photosensitive material that has excellent shelf life.

[Structure of the invention]

The above object of the present invention is to provide a heat-developable photosensitive material having at least silver halide, a reducing agent, and a binder on a support, characterized in that the photosensitive material contains a thermal solvent having a melting point of 130° C. or higher as solid particles. This is achieved using a heat-developable photosensitive material.

The thermal solvent of the present invention is a compound with a melting point of 30" C or more, preferably 130 C or more and 200 C or less, and is solid at room temperature. Also, the inorganic/organic ratio ("organic conceptual diagram" Yoshio Koda A long time ago, Sankaku Publishing Co., Ltd., 1984) was 0.5 to 3.
0, preferably G 0.7 to 2.5, more preferably i.

Compounds exhibiting properties in the range of .about.2.0 are useful as compounds of the present invention.

More specifically, the heat solvent of the present invention has the following general formula (1
), (II), and (Ill) are preferred.

General formula (1) In the formula, rt and rt are each a hydrogen atom and a carbon number l~
represents an alkyl group having 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a hetyl group. R1 represents an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a heterocyclic group.

General formula (II) In the formula, R4, RlRe and R7 are each a hydrogen atom,
Represents an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or a 1-ring group.

General formula (II) In the formula, Ra and n a are each a hydrogen atom and a carbon number of 1
~12 alkyl group, aryl group having 6 to 12 carbon atoms, or heterocycle J, (represents rt, , which represents 1 to 12 carbon atoms
represents an alkyl group, an aryl group having 6 to 12 carbon atoms, or a heterocyclic group.

A particularly preferable thermal solvent in the present invention is the following general formula (I
V).

General formula (1v) In the formula, RII and RI2 are each a hydrogen atom, and have 1 to 1 carbon atoms.
12 alkyl group, an aryl group having 6 to 12 carbon atoms, or a heterocyclic group. R+s, R14,R+s
, R+a.

RB is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heterocyclic group having 6 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms, respectively. No oxy group, halogen atom, or hydroxy group is shown. Also R++ and Rl! + or any two adjacent ones of R13 to R+7 may be bonded to form a 5- or 6-membered ring.

The alkyl group having 1 to 12 carbon atoms shown in RI-R57 includes those having a substituent. For example, methyl group, ethyl group, 2-methoxyethyl group, trichloromethyl group,
Hydroxymethyl group, hydroxyethyl group, isopropyl group, butyl group, t-amyl group, n-octyl group, 2-
Examples include ethylhexyl group and hensyl group.

The aryl group having 6 to 12 carbon atoms shown in R+4 R above includes those having a substituent. Examples include phenyl group, tolyl group, 4-chlorophenyl group, 3-chlorophenyl group, 4-methoxyphenyl group, 2-ethoxyphenyl group, 4-bromophenyl group, 4-hydroxyphenyl group, and naphthyl group.

The heterocyclic group having 6 to 12 carbon atoms represented by R1 to R17 includes those having substituents, such as 3-pyridyl group, 3-furyl group, 2-imidazole group, 2-chenyl group, etc. .

The alkoxy group having 1 to 12 carbon atoms shown in R13 to TLr7 includes those having a 1ξ substituent. Examples include methoxy, ethoxy, benzoyloxy, butquin, and isopropoxy groups.

The aryloxy group having 6 to 12 carbon atoms represented by R83 to R87 includes those having a substituent.

Examples include phenoxy group, tolyloxy group, 2-naphdyloxy group, and 4-chlorophenoxy group.

Said R1, ~R1? The halogen atom shown in is fluorine, chlorine, bromine, iodine, etc.

゛Specific compound examples of the thermal solvent of the present invention are shown below, but the present invention is not limited thereto.

Melting point Inorganic/Organic Melting point Inorganic/Organic C (CI2) scONHz 141'C1
, 44 melting point Inorganic/organic melting point Inorganic/organic melting point Inorganic/organic melting point Inorganic/organic Many of these compounds are commercially available, and can be easily synthesized by those skilled in the art. General formula (I
The same applies to the compound represented by V), but in the synthesis Beil, 9.486, 13eil.

9.465.11 ail, 10(2), 100,
B cil, lo(2) 82, [3eil.

9.33B, Be11.9, 341 can be referred to.

The thermal solvent of the present invention is added to the heat-developable photosensitive material as homogeneous particles. As for the addition method, it is preferable to add after pulverizing and dispersing using a pulverizer such as a ball mill, sand mill, or colloid mill.

In this case, it is preferable that a protective colloid agent coexists during the pulverization and dispersion. Protective colloids include gelatin, gelatin derivatives (e.g. phenylcarbamoylated gelatin,
phthalated gelatin, etc.), gum arabic, albumin,
Sodium alginate, polyvinylpyrrolidone, and the like are useful. These protective colloid agents are preferably used as an aqueous solution of 5% by weight or less.

The average particle diameter of the solid particles of the heat solvent of the present invention is 10 μm or less, preferably 0.05 μm or more and 2 μm or less.

The temperature during dispersion of the hot solvent is between 5°C and 70'C, preferably between 1Q'C and 50'C.

For the part of the pulverizer that comes into contact with the hot solvent dispersion, it is preferable to avoid metal and use an inorganic material such as ceramics, alumina, glass, or ceramic, or a synthetic polymer material such as hard polyethylene or Teflon.

The thermal solvent of the present invention can be added to any layer in the photothermographic material. That is, there may be a photosensitive layer containing silver halide or a non-photosensitive layer such as an intermediate layer, a protective layer, an undercoat layer, etc., but a photosensitive layer or a layer adjacent thereto is preferred.

The amount of the heat solvent added in the present invention is one for the photosensitive layer and one for the binder.
0.3 Li to 2.47 per g, preferably 0.5 g to 2
．． It is 09. In the case of a non-photosensitive layer, 0.1 g to 3.0 fl;
Preferably it is 0.37 to 2.4 rl. When the photothermographic material of the present invention has a multilayer structure, M of the heat solvent contained in a certain area is 0.1 g to 3.09, preferably 0.5 g to 2.0 g, per binder 19 contained therein. .09
It is.

The thermal solvent of the present invention can be used in combination of two or more, or can be used in combination with six known thermal solvents other than the present invention. In this case, the amount of the hot solvent other than the one according to the invention is preferably 30% by weight or less of the total amount of the hot solvent.

The photosensitive silver halide used in the present invention includes silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodide, silver iodobromide,
Examples include silver chloroiodobromide. The photosensitive silver halide is
Although it can be prepared by any method in the photographic field such as a single jet method or a double jet method, in the present invention, a photosensitive silver halide emulsion prepared according to a conventional method for preparing a silver halide gelatin emulsion is used. A light-sensitive silver halide emulsion containing 0.05 to 1.5 g gives favorable results.

The light-sensitive silver halide emulsion may be chemically sensitized by any method known in the photographic art. Such sensitization methods include
Various methods include gold sensitization, sulfur sensitization, gold-sulfur sensitization, and reduction sensitization.

The silver halide in the above-mentioned photosensitive emulsion may be coarse or fine, but the preferred grain size is about 0.001 μm to about 1.5 μm, more preferably about 0.001 μm to about 1.5 μm, and more preferably about 0.001 μm to about 1.5 μm. .01 μm to about 0.5 μm.

The photosensitive silver halide emulsion prepared as described above can most preferably be applied to the heat-developable photosensitive layer which is a constituent layer of the photosensitive material of the present invention.

In the present invention, as another method for preparing photosensitive silver halide, a photosensitive silver salt-forming component may be allowed to coexist with an organic silver salt described below, and photosensitive silver halide may be formed in a part of the organic silver salt. can. The photosensitive silver salt forming component used in this preparation method is an inorganic halide, for example, a halide represented by MXn (where M is an H atom, Nl (,
represents a group or a metal atom, and X represents Ci2. Br or I
, and n is 1 when M is an II atom, NHa, or a group. M
When is a metal atom, it indicates its valence. Metal atoms include lithium, sodium, potassium, rubidium, cesium, copper, gold, beryllium, magnesium, calcium, strontium, barium, zinc, cadmium, mercury, aluminum, indium, lanthanum, ruthenium,
Examples include chromium germanium, tin, lead, antimony, bismuth, chromium, molybdenum, tungsten, manganese, rhenium, iron, cobalt, nickel, rhodium J1, palladium, osmium, iridium, platinum, and cerium. ), halogen-containing metal complexes (e.g., KtPt
C12o, KtPtllro.

11AucL,, (NHa)tlrc12a, (N
Ha4)alrc(!o, (Nlla)tRuCI2
a, (Ni14)JuC5o, (N)I, )21? h
CI2. , (N11.), I? hBr, etc.), onium halides (e.g., quaternary ammonium 11 halides such as tetramethylammonium bromide, trimethylphenylammonium bromide, cetylethyldimethylammonium bromide, 3-methyldeazolium bromide, trimethylbenzylammonium bromide, tetraethylphosph) 4 like onium bromide
Tertiary sulfonium halides such as phnasphonium halide, penzyl ethyl methyl sulfonium bromide, bromo-2-methylpropane, etc.), N-
Halogen compounds (N-chloro [J succinimide, N-bromosuccinimide, N-bromophthalimide, N-
Bromoacetamide, N-iodosuccinimide, N-
Bromophthalazinone, N-chlorophthalazinone, N-bromoacetanilide, N,N-dibromobenzenesulfonamide, N-bromo-N-methylbenzenesulfonamide, 1,3-dibromo-4,4-tumedelhydantoin, etc. ), other halogen-containing compounds (eg, triphenylmethyl chloride, triphenylmethyl bromide, 2-bromobutyric acid, 2-bromoethanol, etc.).

These photosensitive silver halides and photosensitive silver salt-forming components can be used in combination in various methods, and the amount used is 0.002 to 1 mole of the dye image-9 material monomer.
It is preferably from mol to 10 mol, more preferably from 0.2 mol to 2.0 mol.

The heat-developable color photosensitive material of the present invention has a multilayer structure including each layer sensitive to blue light, green light, and red light, that is, a heat-developable blue-sensitive layer, a heat-developable green-sensitive layer, and a heat-developable red-sensitive layer. You can also. Further, the photosensitive layer of the same color can be divided into two or more layers L (for example, a high-sensitivity layer and a low-sensitivity layer).

In the above cases, the blue-sensitive silver halide emulsion, green-sensitive silver halide emulsion, and red-sensitive silver halide emulsion used, respectively, are obtained by adding various spectral sensitizing dyes to the surface silver halide emulsion. be able to.

Typical spectral sensitizing dyes used in the present invention include, for example, cyanine, merocyanine, complex (trinuclear or tetranuclear) cyanine, holopolar cyanine, sudaryl, hemicyanine, oxonol, and the like. Among cyanine dyes, those having a basic nucleus such as thiazoline, oxazoline, viroline, pyridine, oxazole, thiazole, selenazole, and imidazole are more preferred. Such a nucleus contains an alkyl group, an alkylene group, a hydroxyalkyl group, a sulfoalkyl group, a carboxyalkyl group, an aminoalkyl group or an enamine group capable of forming a fused carbocyclic or heterocyclic ring. Good too. Further, it may be symmetrical or asymmetrical, and the methine chain or polymethine chain may have an alkyl group, a phenyl group, an enamine group, or a heterocyclic substituent.

In addition to the above basic nucleus, the merocyanine dye may have a strong acidic nucleus such as a diohydantoin nucleus, a rhodanine nucleus, an oxazolidine nucleus, a barbyl nucleus, a deazolithion nucleus, a malononitrile nucleus, or a pyrazolone nucleus. These acidic nuclei may be further substituted with an alkyl group, an alkylene group, a phenyl group, a carboxyalkyl group, a sulfoalkyl group, a hydroxyalkyl group, an alkoxyalkyl group, an alkylamine group, or a heterocyclic nucleus.

If necessary, these dyes may be used in combination. Furthermore, ascorbic acid derivatives, azaindene cadmium salts, sulfonic acid, etc., such as U.S. Pat. No. 2,933,
A supersensitizing additive that does not absorb visible light, such as those described in the specifications of No. 390 and No. 2,937,089, can be used in combination.

The amount of these dyes added is I x 10 -' mol - 1 mol per mol of silver monogenide or silver halide forming component. More preferably IXIG-'mol to IXIG-'
It is a mole.

Further, in the present invention, it is preferable to add an organic silver salt.

In the heat-developable photosensitive material of the present invention, various types of silver salts can be used, if necessary, for the purpose of increasing sensitivity and improving developability.

As the Tf machine silver salt used with the heat-developable photosensitive material of the present invention, Japanese Patent Publication No. 4: (-4921, No. 44-2658)
No. 2, 45. -18416, No. 45-12700, No. 45-22185, JP-A-49-52626,
No. 52-31728, No. 52-137321, No. 5
No. 2-141222, No. 53-: 36224 and No. 53-37610, as well as U.S. Pat.
, No. 105,451, No. 4,123,274, No. 4.168.980, etc., such as silver salts of aliphatic carboxylic acids, such as silver laurate,
Silver myristate, silver palmitate, silver stearate, silver arachidonate, silver behenate, silver α-(1-phenyltetrazolthio)acetate, etc., silver aromatic carboxylates, such as silver benzoate, silver phthalate, etc. Tokuko Showa 44-26582
No. 45-12700, No. 45-18416, No. 45-22185, JP-A-52-31728, No. 5
Silver salts of imino groups, such as benzotriazole silver, 5-
Methylbenzotriazole silver, 5-acetamidobenzotriazole silver, 5-nitrobenzotriazole silver, 5
-chlorobenzotriazole silver, 5-methoxybenzotriazole silver, 4-sulfobenzotriazole silver, 4-
Hydroxybenzotriazole silver, 5-aminobenzotriazole silver, 5-methylsulfobenzotriazole silver, 5-carboxybenzotriazole silver, imidazole silver, benzimidazole silver, 6-nidropenzimidazole silver, pyrazole silver, urazole silver, 1, 2゜4-triazole, I 11-tetrazole silver, 3-amino-5-benzylthio-1,2,4-1-riazole silver,
Silver saccharin, silver phthalazinone, silver phthalimide, etc.
Others 2-mercaptobenzoxazole silver, mercaptooxadiazole silver, 2-mercaptobenzodeazole silver, 2-mercaptobenzimidazole silver, 3-mercapto-4-phenyl-1,2,4-)riazole silver,
4-human [1xy-6-methyl-1,3,3a, 7-titrazaindene silver and 5-methyl-7-hydroxy-
Examples include 1,2,3,4,6-pentazaindene silver.

Among the organic silver salts of -H below, silver salts of imino groups are preferred, and silver salts of benzotriazole derivatives are particularly preferred.

The organic silver salts used in the present invention may be used alone or in combination of two or more, and isolated ones may be used by dispersing them in a binder by appropriate means, or they may be used in combination with a suitable binder. A silver salt may be prepared therein and used as is without isolation.

The amount of the organic silver salt used is 1 unit of the dye-donating substance.
The amount per mole is preferably 0.1 to 5 mol, more preferably 0.3 mol to 3 mol.

As the reducing agent used in the photothermographic material of the present invention, those commonly used in the field of photothermographic materials can be used, such as those disclosed in US Pat. No. 3,531,286 and US Pat.
No. 761,270 and No. 3,764,328, each specification 2
F, also FL D No. 12146, same No. 1
510g, same No. 15127 and JP-A-1983-
Examples thereof include p-phenylenediamine-based and p-aminophenol-based developing agents, phosphoramidophenol-based and sulponamidophenol-based developing agents, and hydrazone-based color developing agents described in Japanese Patent No. 27132 and the like.

Also, U.S. Patent Nos. 3,342,599 and 3,71
No. 9,492, JP-A-53-135628, JP-A No. 54-
Color developing agent precursors described in No. 79035 and the like can also be used advantageously.

As a particularly preferable reducing agent, JP-A-56-14613:
(Reducing agents represented by the following general formula [20] described in the specification of No.

General formula [20] In the formula, El' and It3 are hydrogen atoms, or have 1 to 30 carbon atoms (preferably 1 to 30 carbon atoms, which may have 6 L substituents).
4) represents an alkyl group, and R1 and R' may be ring-closed to form a heterocycle. R', R', It5 and It
' is a hydrogen atom, a halogen atom, a hydroxy group, an amino group, an alkoxy group, an acylamido group, a sulfonamide group, an alkylsulfonamide group, or a substituent. It represents an alkyl group, and It3 and R1 and It5 and R2 may each be closed to form a heterocycle. M represents an alkali metal atom, a nitrogen-containing base, or a compound containing a quaternary nitrogen atom.

The nitrogen-containing organic base in the general formula [20] is an a-organic compound containing a basic nitrogen atom capable of forming a salt with an inorganic acid, and particularly important organic bases include amine compounds. And as a chain amine compound, the first
Typical examples of cyclic amine compounds include pyridine, quinoline, piperidine, and imidazole, which are typical examples of heterocyclic organic bases. In addition, compounds such as hydroxylamine, hydrazine, and amidine are also useful as chain amines. Salts of nitrogen-containing organic bases include the above-mentioned inorganic acid salts of organic bases (e.g. hydrochlorides, sulfates,
nitrates, etc.) are preferably used.

On the other hand, examples of the compound containing quaternary nitrogen in the above general formula (20) include salts or hydroxides of substituted compounds having a tetravalent covalent bond.

4I.

Next, preferred specific examples of the reducing agent represented by the general formula [20] are shown below.

(R-1) (R-2) (R-3) (R-6) (R-7) (R-8) (R-9) (R-10) (R-11) (R-12) (R-13) (R-14) (R~15) ' (R-16) (R-17) (R-18) (R-19) (R-20) (R-21) (R-22 ) (R-23) The reducing agent represented by the above general formula (20) can be prepared by a known method such as tlouben-11eyl, Method
En der Organ-ischen Chemi
It can be synthesized according to the method described in e, BandX I/2.645-703.

Other reducing agents as described below can also be used.

For example, phenols (e.g., p-phenylphenol, p-methoxyphenol, 2,6-tert-butyl-p-cresol, N-methyl-p-aminophenol, etc.), sulfonamide phenols [e.g., 4-
Benzenesulfonamidophenol, 2benzenesulfonamidophenol, 2゜6-dichloro-4-benzenesulfonamidophenol, 2,6-dibromo-4-(
p-)luenesulfonamide) phenol, etc.], or polyhydroquine benzenes (e.g. hydroquinone,
tert-butylhydroquinone, 2,6-dimethylhydroquinone, chlorohydroquinone, carboxyhydroquinone, catechol, 3-carboxycatechol, etc.), naphthols (e.g. α-naphthol, β-naphthol, 4-aminonaphthol, 4-methquinnaphthol) etc.), hydroxybinaphthyls and methylene bisnaphthols [e.g.! , 1'-dihydroxy-2.2'
-binaphthyl, 6.6'-dibromo-2,2'-onehydroxy-t, t'-binaphthyl, 6.6-sinitro2.2'-dihydroxy-1,1'-binaphthyl, 4.
4'-dimethoxy-1,1'-dihydroxy-2,2'
-binaphthyl, bis(2-hydroxy-1-naphthyl)
methane, etc.], methylene bisphenols [e.g. 1.1
= His(2-hydroxy-3,5-dimethylphenyl)
-3,5,5-trimethylhexane, 1,1-bis(2
-hydroxy-3-tert-butyl-5-methylphenyl)methane, 1,1-bis(2-hydroxy-3,5
~di-tert-butylphenyl)methane, 2,6-methylenebis(2-hydroxy-3-tert-butyl-
5-methylphenyl)-4-methylphenol, α-phenyl-α, α-bis(2-hydroxy-3,5-di-tert-butylphenyl)methane, α-phenyl-α
, α-bis(2-hydroxy-3-tert-butyl-
5-methylphenyl)methane, 1,1-bis(2-hydroxy-3,5-dimethylphenyl)-2-methylpropane, 1,1,5.5-tetrakis(2-hydroxy-
3,5-dimethylphenyl)-2,4-ditylbencune, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3
-Methyl-5=tert-butylphenyl)propane, 2,2-bis(4-hydroxy-3,5-di-tert)
t-butylphenyl)propane, etc.], ascorbic acids, 3-pyrazolidones, ascorbic acids, 3-pyrazolidones, pyrazolones, hydrazones, and paraphenylenediamines.

These reducing agents can be used alone or in combination of two or more. The amount of reducing agent used depends on the type of photosensitive silver halide used, the type of organic acid silver salt, and the type of other additives used, but it is usually about 1 mole of the dye-providing substance monomer. The amount ranges from 0.05 to 10 mol, preferably from 0.1 to 5 mol.

Examples of the binder used in the heat-developable photosensitive material of the present invention include synthetic or natural polymers such as polyvinyl butyral, polyvinyl acetate, ethyl cellulose, polymethyl methacrylate, cellulose acetate butyrate, polyvinyl alcohol, polyvinylpyrrolidone, gelatin, and phthalated gelatin. One or more molecular substances can be used in combination. In particular, it is preferable to use gelatin or a derivative thereof in combination with a hydrophilic polymer such as polyvinylpyrrolidone or polyvinyl alcohol, and more preferably the following binder described in Japanese Patent Application No. 104249/1982.

This binder includes gelatin and vinylpyrrolidone polymer. The vinyl pyrrolidone polymer may be polyvinyl pyrrolidone, which is a monopolymer of vinyl pyrrolidone, or a copolymer of vinyl pyrrolidone with one or more other monomers that can be copolymerized (Cura 7! Co-polymer). (including polymers). These polymers can be used regardless of their degree of polymerization. Polyvinylpyrrolidone may be substituted polyvinylpyrrolidone, and preferred polyvinylpyrrolidone has a molecular weight of 1.000 to
400.000. Other monomers copolymerizable with vinylpyrrolidone include (meth)acrylic acid esters such as acrylic acid, methacrylic acid and alkyl esters thereof, vinyl alcohols, vinyl imidazoles, (meth)acrylamides, vinyl carbinols, Examples include vinyl monomers such as vinyl alkyl ethers, but it is preferable that polyvinylpyrrolidone accounts for at least 20% (weight %, same hereinafter) of the composition ratio. A preferred example of such a copolymer has a molecular weight of 5,000
0 to 400.000.

Gelatin may be obtained by lime treatment or acid treatment, and may be ossein gelatin, pickskin gelatin, hydrogelatin, or modified gelatin obtained by esterifying, phenylcarbamoylating, or phthalating these gelatins.

In the binder, gelatin preferably accounts for 10 to 90%, more preferably 20 to 60%.

1- The binder may contain other polymeric substances, such as gelatin and a mixture of polyvinylpyrrolidone with a molecular weight of 1.000 to 400,000 and one or more other polymeric substances, gelatin and a molecular weight s ,ooo～400゜0
A mixture of the vinylpyrrolidone copolymer No. 00 and one or more other polymeric substances is preferred. Other polymeric substances that can be used include polyvinyl alcohol, polyacrylamide, polymethacrylamide, polyvinyl butyral, polyethylene glycol, polyethylene glycol ester, or proteins such as cellulose derivatives,
Natural substances such as starch, polysaccharides such as gum arabic and the like can be mentioned. These range from 0 to 85%, preferably from 0 to 70%
% may be contained.

Note that the vinyl pyrrolidone polymer may be a crosslinked polymer, but in this case, it is preferable to crosslink it after coating it on the support (including the case where the crosslinking reaction progresses by being left to stand).

The use of binder is usually 0.0 per In” of the support.
05g to 100g, preferably 0.01g to 40g
It is g. Further, the binder is preferably used in an amount of 0.1 to 10 g, more preferably 0.25 to 4 g, per unit tg of the dye-donating substance monomer.

In the heat-developable photosensitive material of the present invention, it is preferable to add a dye-providing substance, and a preferred embodiment is to obtain a color image by this addition.

As the dye-providing substance of the present invention, a particularly diffusible dye-providing substance that can be preferably used in the present invention will be explained. The dye-donating substance may be one that participates in the reduction reaction of silver halide and/or organic silver salt and can form a diffusible dye as a function of the reaction, and depending on the form of the reaction, it may have a positive function. negative-working dye-donors (i.e., form a negative dye image when negative-working silver halide is used) and positive-acting dye-donors (i.e., form a negative dye image when negative-working silver halide is used). (forms a positive dye image when using negative silver halide). Negative dye-donating substances are further classified as follows.

Each dye-providing substance will be further explained.

As the reducing dye releasing compound, for example, the following general formula (2
Examples include compounds represented by 1).

General formula (2I) Car-NIISO2=D yc In the formula, Car is a reducing substrate that is oxidized and releases a dye upon reduction of silver halide and/or (-fIli silver salt (
Dye is a diffusible dye residue.

Specific examples of the reducible dye-releasing compounds listed in L are given in Japanese Patent Application Laid-Open No.
No. 7-179840, No. 5g-116537, No. 59
-60434, 59-65839, 59-71
No. 046, No. 59-87450, No. 59-88730
No. 59-123837, No. 59-165054, No. 59-165055, etc., and examples thereof include the following compounds.

Exemplary dye-providing substance■ Another reduced dye-releasing compound is, for example, the general formula (22)
Examples include compounds represented by:

In the formula, A1 and Δ each represent a hydrogen atom, a hydroxyl group, or an amino group, and Dye is the same & as Dye shown in general formula (2I). Specific examples of the compound represented by the general formula (22) are shown in JP-A-59-124329.

As a coupled dye-releasing compound, general formula (2
Examples include compounds shown in 3).

General formula (23) % formula % In the formula, cp is a group (so-called coupler residue) that can react with the oxidized form of the reducing agent to release a diffusible dye.
, J is a divalent bonding group, and the bond between Cpl and J is cleaved by reaction with the oxidant of the reducing agent. n represents O or 1, and Dye has the same meaning as defined in general formula (21). In addition, Cpl is preferably substituted with various ballast groups in order to make the coupled dye-releasing compound non-diffusible. or more (more preferably 12 or more) 41 groups, or hydrophilic groups such as sulfo groups or carboxy groups, or 8 or more (more preferably 12 or more carbon atoms on each side) and sulfo groups or carboxy groups It is a group that also has hydrophilic groups such as.

Another particularly preferred ballast group can include polymer chains.

, as a specific example of the compound represented by the general formula (23) in F, Teha, JP-A-57-186744, JP-A-57-1225.
No. 96, No. 57-160698, No. 59-17483
No. 4, No. 57-224883, No. 59-159159
No. 59-104901, examples of which include the following compounds.

Exemplary dye-providing substance ■ Coupling dye-forming compounds include the following general formula (2
Examples include compounds shown in 4).

General formula (24) % formula %) ( ) In the formula, Cps is an organic group that can react with the oxidized product of the reducing agent (cubupling reaction) to form a diffusible dye (
(so-called coupler residue), where X represents a divalent bonding group and Q represents a ballast group.

The coupler residue represented by Cpt is preferably 700 or less for the molecule due to the diffusibility of the dye formed.
More preferably it is 500 or less.

In addition, the ballast group of Q is preferably the same ballast group as the ballast group defined in general formula (23), and in particular, the ballast group with the 8 side and (
A group having both carbon atoms (more preferably 12 or more) and a hydrophilic group such as a sulfo group or a carboxy group is preferred, and a polymer chain is even more preferred.

As the coupling dye-forming compound having this polymer chain, a polymer having a repeating unit derived from a monomer (11) represented by the following general formula (25) is preferable.

General formula (25) %Formula% (7) In the formula, CI)2 and X have the same meanings as defined in general formula (24), Y represents an alkylene group, arylene group or aralkylene group, and Z represents Represents a divalent organic group, L
represents an ethylenically unsaturated group or a group representing an ethylenically unsaturated group.

Specific examples of coupling dye-forming compounds represented by general formulas (24) and (25) include JP-A-59-1243
No. 39, No. 59-181345, Patent Application No. 581092
No. 93, No. 59-179657, No. 59-13160
4 So, No. 59-132506, No. 59-182507
It is described in the specifications of and, for example, the following compounds.

Exemplary dye-providing substance ■ 16H3a ■ H ■ C1ell+s "Polymer ■ [Co.] I13 H3 H In the above general formulas (23), (24) and (25), regarding the coupler residue defined by CI) + or Cpt, Specifically, groups represented by the following general formula are preferred.

In the formula, nl, R2, R3 and R4 are each a hydrogen atom, a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, an acyl group, an alkyloxycarbonyl group, an aryloxycarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, It represents a carbamoyl group, a sulfamoyl group, an acyloxy group, an amino group, an alkoxy group, an aryloxy group, a cyano group, a ureido group, an alkylthio group, an aryldio group, a carboxyl group, a sulfo group, or a heterocyclic residue, which can further be hydroxyl, carboxyl, etc. basis,
It may be substituted with a sulfo group, an alkokene group, a cyano group, a nitro group, an alkyl group, an aryl group, an aryloxy group, an acyloxy group, an acyl group, a sulfamoyl group, a carbamoyl group, an imide group, a halogen atom, or the like.

These substituents are selected depending on the purpose of CI)+ and Cpt, and as described in 13if <Cp+, one of the substituents is preferably a ballast group, and in Cpt, it is preferable to In order to increase the molecular weight, the substitution J& is preferably selected so that the molecular weight is 700 or less, more preferably 500 or less.

As a positive dye-donating substance, for example, the following general formula (2
There is an oxidative dye-releasing compound represented by 6).

In the formula, W+ represents an atomic group necessary to form a quinone ring (which may have a substituent on this ring), R5 represents an alkyl group or a hydrogen atom, and BB represents *R
8 ■ -N -CiR7 (in the formula, R6 represents an alkyl group or a hydrogen atom, R7
represents an oxygen atom or -N-. ) or -SO, -, r represents 0 or I, Dye is the general formula (21)
It has the same meaning as defined in .

Specific examples of this compound are described in the specifications of JP-A-59-166954 and JP-A-59-154445, and include the following compounds.

Exemplary dye-donor substances H3 Another positive dye-donor substance is represented by the following general formula (27).
There are compounds that lose their dye-releasing ability when oxidized, such as the compound represented by:

[Jll In the formula, W2 represents an atomic group necessary to form a benzene ring (which may have a substituent on the ring), and Tl 5,
■(, "and Dye is defined by general formula (17)'
It is synonymous with thing. A specific example of this compound is JP-A-59-
No. 124329, No. 59-154445, etc., and include, for example, the following compounds.

, 7゛4°ゝ or less, Yu゛Yu\-1, ・' Exemplary dye-donor substance [Co., Ltd.] Still another positive dye-donor substance has the following general formula (
Examples include compounds represented by 28).

In the general formula (28), W'', Ie'' and I)ya have the same meanings as defined in the general formula (27). Specific examples of this compound are described in JP-A-59-154445, etc., and include the following compounds.

Exemplary dye-providing substance [phase] General formula (21), (22), (26), (27) above
The residue of the diffusible dye represented by Dye in and (28) will be described in further detail. The residue of the diffusible dye preferably has a molecular weight of 800 or less, more preferably 600 or less, for the sake of the diffusibility of the dye;
Examples include residues such as azomethine dyes, anthraquinone dyes, naphthoquinone dyes, styryl dyes, nitro dyes, quinoline dyes, carbonyl dyes, and phthalocyanine dyes.

These dye residues may be in a temporary short-waveform form that allows multiple colors during thermal development or transfer. In addition, these dye residues reduce the light fastness of the image [1, for example,
No. 9-48765, No. 50-124: (The chelatable dye residue described in No. 37 is also a preferred form.

These dye-providing substances may be used alone or in combination of two or more. Its use! Kura is not limited to the type of dye-donating substance,? The amount to be used may be determined depending on whether the photographic constituent layer of the photosensitive material is a single layer or a multilayer of two or more. .005g to 50g, preferably 0.1
g to IOg can be used.

The dye-providing compound described above can be incorporated into the photographic constituent layer of the heat-developable light-sensitive material using any method. etc.) without ultrasonic dispersion or in an alkaline aqueous solution (e.g. 10% aqueous sodium hydroxide solution etc.).
It can be used after being neutralized with hydrochloric acid or nitric acid, etc., or after being dispersed using a grinder with an aqueous solution of an appropriate polymer (e.g., gelatin, polyvinylbutyrate, polyvinylpyrrolidone, etc.). .

In addition to the above-mentioned components, various additives may be added to the heat-developable photosensitive material of the present invention, if necessary.

For example, as a development accelerator, U.S. Patent No. 3.220°8
No. 40, No. 3.531,285, No. 4.012,
No. 260, No. 4,060,420, No. 4.01'
No. 38,496 No. 4,207,392 Each town! F
, rj I) No, l5LH1 Same No, 1573
No. 4, No. 15776, JP-A-56-1307
Urea described in No. 45, No. 56-132332, etc.
Alkali releasing agents such as guanidium trichloroacetate;
Non-aqueous polar solvent compound with -5o- group (f), Melt former described in U.S. Pat. No. 3,438,776 U.S. Pat.
There are polyalkylene glycols described in No. In addition, as a color toning agent, for example, JP-A-46-4928, JP-A-46-4928;
No. 6-6077, No. 49-5019, No. 49-502
No. 0, No. 49-91215, No. 49-107727, No. 50-2524, No. 50-67132, No. 5 (
No. 1-67641, No. 50-114217, No. 52-
No. 33722, No. 52-99813, No. 53-102
No. 0, No. 53-55115, No. 53-76020,
No. 53-125014, No. 54-156523, No. 54-156524, No. 54-156525,
No. 54-156526, No. 55-4060, No. 55
Publications such as -4061 and 55-32015, as well as West German Patent No. 2.140,406 and West German Patent No. 2,147,0.
No. 63, No. 2,220.618, U.S. Patent No. 3,08
0.254, 3,847,612, 3,7
No. 82,941, No. 3,994,732, No. 4,
Phthalazinone, phthalimide, pyrazolone, quinazolinone, N-hydroxynaphthalimide, benzoxazine, naphthooxazinedione, 2.3 -dihydro-phthalazinedione, 2,3
-nohydrocl-1,3-year-old Quizazine-2,71-dione, oquinpyridine, aminopyridine, hydroxyquinoline, aminoquinoline, isocarbostyryl, sulponamide, 211-1.3-benzothiazine-2゜4-(3
H) Diones, benzotriazine, mercaptotriazole, nomercaptotetrazapentalene, phthalic acid, naphthalic acid, phthalamic acid, etc., mixtures of one or more of these with imidazole compounds, and phthalic acid, naphthalic acid at least one acid or acid anhydride such as
Examples include mixtures of phthalazine and phthalazine compounds, and combinations of phthalazine and maleic acid, itaconic acid, quinolinic acid, gentisic acid, and the like.

Also, JP-A-58-189628, JP-A-58-1934
3-amino-5-mercapto-1゜2.4-) lyazoles and 3-acylamino-5 described in Publication No. 60
-Mercapto-1,2,4-triazoles are also effective.

In addition, as a stabilizer, a printout preventive agent may also be used at the same time, especially after processing.
The halogenated hydrocarbons described in Publication No. 53-46020, specifically, tetrabromobutane, tribromoethanol, 2-bromo-2-tolylacetamide, 2-
Bromo-2-tolylsulfonylace1-amide, 2-tribromomethylsulfonylbenzothiazole, 2,4-
Examples include bis(tribromomethyl)-6-methyltriazine.

Also, Japanese Patent Publication No. 46-5393, Japanese Patent Publication No. 50-54329
A post-treatment may be carried out using a sulfur-containing compound as described in No. 50-77034.

Furthermore, U.S. Patent No. 3,301,678;
506゜444, same No. 3,824.103, same No. 3
, 844,788, as well as the isothiuronium stabilizer precursors described in U.S. Patent No. 3.6.
No. 69,670, No. 4,012,260, No. 4,
It may contain the actylvator stabilizer precursor described in 060,420 and the like.

Also, sucrose, N114FO(Sot)t"1211t
A water release agent such as O may be used.
Heat development may be performed by supplying water as in No. 6-132332.

In addition to the above-mentioned components, the light-sensitive material of the present invention may further include spectral sensitizing dyes, antihalation dyes, optical brighteners, hardeners, antistatic agents, plasticizers, and various additives such as spreading knots. Coating aids etc. are added.

The heat-developable photosensitive material of the present invention basically has (1
) photosensitive silver halide, (2) reducing agent, (3) iT12
It is preferable to contain a silver salt and (4) a binder. Furthermore, it is preferable to contain (5) a dye-providing substance as necessary.

However, these are not necessarily included in a single photographic constituent layer.
The components (+), (3), and (4) may be contained in one photosensitive layer, and (2) and (5) may be contained in another layer adjacent to this photosensitive layer. , they may be contained separately in two or more photographic constituent layers as long as they are in a state where they can react with each other.

Furthermore, the photosensitive layer may be divided into two or more layers, such as a high-sensitivity layer and a low-sensitivity layer, and may further include one or more photosensitive layers having different color sensitivities. It may also have various photographic constituent layers such as a two-coat layer, an undercoat layer, a backing layer, an intermediate layer, or a single filter layer.

The heat-developable photosensitive layer of the photosensitive material of the present invention, a protective layer, an intermediate layer, an undercoat layer, a back layer, which may be provided as necessary,
Other photographic constituent layers can be formed by adjusting the coating solution and applying the dipping method, air knife method, curtain coating method or U.S. Patent No. 3
The photosensitive material can be prepared by various coating methods such as the hopper coating method described in , No. 681,294.

Furthermore, if desired, two or more layers can be applied simultaneously by the methods described in US Pat. No. 2,761.791 and British Patent No. 837,095.

11 used in the photographic constituent layer of the heat-developable photosensitive material of the present invention
The above components are applied onto a support, and the thickness of the coating after drying is preferably 1 to 1,000 μm, more preferably 3 to 2 μm.
It is 0 μm.

The support used in the heat-developable photosensitive material of the present invention includes:
For example, synthetic plastic films such as polyethylene film, cellulose acetate film, polycarbonate film, polyimide film, polyethylene terephthalate film, polyvinyl chloride, and paper supports such as photographic base paper, printing paper, baryta paper, and resin coated paper. etc.

After the heat-developable photosensitive material of the present invention is imagewise exposed as it is,
Usually 80°C to 200°C, preferably 120°C to 170°C
at a temperature range of 1 second to 180 seconds, preferably 1.5
Color development can be achieved by simply heating for 120 seconds. Further, if necessary, the film may be developed with a water-impermeable material in close contact with the film, or it may be preheated at a temperature in the range of 70° C. to 180° C. before exposure.

Various exposure means can be used for the photothermographic material according to the present invention. The latent image is obtained by imagewise exposure to radiation, including visible light. In general, light sources used for ordinary color printing, such as tungsten lamps, mercury lamps, xenon lamps, laser beams, CR'r beams, etc., can be used as the light source.

As the heating means, all methods applicable to ordinary heat-developable photosensitive materials can be used, such as contacting with a heated block or plate, contacting with a heated roller or drum, passing through a high-temperature atmosphere, etc. Alternatively, high frequency heating can be used, or furthermore, a conductive layer can be provided in the photosensitive material of the present invention or in the image receiving layer (element) for thermal transfer, and Joule heat generated by electricity or a strong magnetic field can be utilized. There are no particular restrictions on the heating pattern, including preheating (breheating) and then reheating, continuous rises, falls, or repeats at high temperatures for short periods of time, low temperatures for long periods of time, and even discontinuous heating patterns. Although heating is possible, a simple pattern is preferred. Further, when the photothermographic material of the present invention contains a dye-providing substance that releases or forms a diffusible dye, it is necessary to use an image-receiving layer.

In the present invention, as the image-receiving layer that receives the diffusible dye formed imagewise by imagewise exposure and thermal development of the photographic constituent layer, those commonly used in this field can be used, such as paper, Although cloth, Plus Deck, etc. can be used, it is preferable to use a support provided with an image-receiving layer containing a mordant or a compound having dye-receiving ability on the support.

As a particularly preferable image receiving layer, Japanese Patent Application No. 58-97907
Layer made of polyvinyl chloride and patent application No. 1983-
A layer made of polycarbonate and a plasticizer described in No. 128600 may be mentioned.

The image-receiving layer may be provided on the same support as the photographic constituent layer, in which case it may have a peel-and-stick structure from the photographic constituent layer after the dye has been transferred, or it may be provided on a separate support. There is no particular restriction on its formation, and any technique can be used.

〔Example〕

Examples of the present invention are shown below, but the embodiments of the present invention are not limited thereto.

Example-■ [Preparation of 5-methylbenzotriazole silver] 5-methylbenzotriazole and silver nitrate were reacted in a mixed solvent of water and ethanol, and 28.8 g of 5-methylbenzotriazole silver and poly-N -150- of water containing 16 g of vinylpyrrolidone (molecule S130.0 OQ) was dispersed in an alumina ball mill, and this dispersion was made into I) I (5,5) and then finished to 200 m12.

[Preparation of dye-providing substance dispersion]

Exemplary dye-providing substance [phase] 97.59, 5.0 g of the following hydroquinone compound was dissolved in ethyl acetate 200-, and a 5 weight rit% aqueous solution of Alkanol XC (manufactured by DuPont) +
24mL Phenylcarbamoylated geladine (Rus a-
The mixture was mixed with 720 ml of gelatin aqueous solution containing 30.5 g of gelatin, Type +7819P C), dispersed with an ultrasonic homogenizer, and after distilling off ethyl acetate, the pH was adjusted to 5.5 and adjusted to 800N+12.

11 [Developer solution] 23.3 g of developer (R-II), the following development accelerator 1. I
Og.

Poly(N-vinylpyrrolidone) (molecular weight 30,000)
Dissolve 0.5 g of the following fluorine-based surfactant in water and add 1
)115.5 and finished it at 250mff.

Phenomenon accelerator surfactant Na0ffS C11C11COOC1lt (CPz
CFt) CI+, C00C11, (CF, CF,)nl
l (mSn==2 or 3) [Preparation of thermal solvent dispersion] Poly(N-vinylpyrrolidone) (molecular 1140,000
426 g of each of the thermal solvents listed in Table 1 below were mixed with 1400 + n (2) of a 1 side 11% aqueous solution of ) and dispersed in an alumina ball mill for 20 hours.

Preparation of heat-developable photosensitive material> 11.12.5 m12 of the organic silver salt dispersion, 40.0 mff of the dye-providing substance dispersion, and 12.5 m12 of the developer.
．． 8.0ml of the above hot solvent dispersion, 10ml of photographic gelatin
Weight% aqueous solution 4.5-1 Silver halide emulsion liquid 6-1 with an average grain size of 0.13 μm (7.5 in terms of silver halide)
A hardening agent solution [tetra(vinylsulfonylmethyl)methane and taurine containing I
:I (weight ratio) and dissolved in phenylcarbamoylated gelatin I% aqueous solution so that tetho(vinylsulfonylmethyl)methane was 3% by weight]2
．． After adding 5-, a silver Fa
2.64 g/m'', and then a protective layer made of a mixture of the phenylcarbamoylated geladine and poly(N-vinylpyrrolidone) (molecule Q: 30.0OO) was provided on the second layer, and photosensitive material No. I-8 were produced.

After drying the resulting light-sensitive material, a white exposure of 8000 CMS was applied through a step wedge.

Next, the image-receiving surface of an image-receiving sheet on which polyvinyl chloride as an image-receiving layer material was coated (1.2 g/m2) on baryta paper and the coated surface of the exposed photosensitive material were overlapped and heated at 150°C for 1 hour. Heat development was performed for a minute, and the image-receiving sheet was peeled off to obtain a magenta transferred image on the image-receiving sheet.

On the other hand, for the same photosensitive material, 50
The same operation was performed on the sample that had been subjected to constant temperature and humidity treatment at 80% relative humidity of ℃ for 48 hours.

Table 1 shows the sensitivity reduction rate ΔS (%) and fog increase density ΔF after the treatment for each sample obtained.

Table 1 Comparative Compounds As is clear from the melting point table ■, the thermal solvent of the present invention showed a small decrease in sensitivity in the forced degradation test assuming raw storage.
It can be seen that it is an excellent product with little fogging.

Example-2 In Example-1, instead of the developer (R-II), (
The same operation as in Example 1 was carried out except that R-12) was used, and the shelf life of the heat-developable photosensitive materials using the heat solvents shown in Table 2 below was investigated. However, polycarbonate was used as the image-receiving material instead of polyvinyl chloride in Example-1.

As is clear from Table 2, it can be seen that the thermal solvent of the present invention is superior to the comparative compounds in that it exhibits less decrease in sensitivity and less increase in fog during storage.

Under the tatami, 'sha t ′、　　　　.

-L-17 Table-2 Comparative Compound Melting Point Inorganic/Organic (d) Saccharin 2266C2,04(e) D-Mannitol 166°C 5,0 Example-3 Preparation of Dye-Providing Substance Dispersion> Exemplary Dye-Providing Substance ■ 2g, 5g tricresyl phosphate 3
0 g and 90 ml of ethyl acetate, mixed with 46 h of a 5% by weight aqueous geladine solution (2) containing alkanol

Preparation of heat-developable photosensitive material> 50ml of the dye-providing substance dispersion, the same silver halide emulsion 40-1 as in Example-1, and 25+Q of organic silver salt liquid were mixed, and 1-phenyl-4,4-dimethyl- 1.5 mQ of 10 wt% methanol solution of 3-pyrazolidone, Example-
3.0 + nL of the same hardening agent as in 1. 18 ml of a 10% water-alcohol solution of guanidine trichloroacetic acid, and 7.5 ml of a dispersion of a hot solvent not shown in Table 3 below, which was dispersed in the same manner as in Example 1. Added and underlined thickness 18
It was coated onto a photographic polyethylene terephthalate film at 0° C. for 1 m at a coating amount of 2.5 g/m 2 .

The following layers were sequentially coated on a 100 μm thick transparent polyethylene terephthalate film.

(1) Layer made of polyacrylic acid. (7,00y/m”
)(2) A layer consisting of cellulose acetate. (4,009/m
(3) A layer consisting of a 1=1 copolymer of styrene and N-benzyl-N, N-dimethyl-N-(3-maleimidopropyl) ammonium chloride and gelatin.

(Copolymer 3.0g/m”) (Gelatin 3.0g/m2) (4) Layer made of urea and polyvinyl alcohol
(Urea 1.0g/Il+') (Polyvinyl alcohol 3.0/m') (Saponification degree 98%) 3.2000 for each sample in the same manner as in Example-1,
M and S exposures were applied, and heat development was similarly carried out at 150° C. for 1 minute to obtain a yellow image on the image-receiving material. Furthermore, Example-1
A constant temperature and humidity treatment was performed in the same manner as above.

Table 3 below shows the sensitivity low F rate ΔS (%) and fog increase density ΔF of each sample.

Table 3 Comparative Compound (d) Melting Point As is clear from Coordination 3, the present invention is also effective when a reducing dye-releasing compound is used as the dye-donating substance and has excellent shelf life. .

Applicant Konishiroku Photo Industry Co., Ltd. Procedural amendment (method) % formula %! , Indication of the case Patent Application No. 278331 filed in 1985 2 Name of the invention Heat-developable photosensitive material 3 Person making the amendment Relationship to the case Patent applicant Location 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Contact address 191 Konishiroku Photo Industry Co., Ltd., 1 Sakuracho, Hino City, Tokyo (Telephone: 0425-83-1521)
Patent Department

Claims (1)

[Claims] 1. A photothermographic material having at least silver halide, a reducing agent, and a binder on a support, characterized in that the photosensitive material contains a thermal solvent having a melting point of 130° C. or higher as solid particles. material.