JPS5828736A - Heat developable photosensitive material - Google Patents

Abstract

PURPOSE:To increase the maximum density and to obtain an image having a black tone by using gelatin or a gelatin deriv. as a binder and forming a water impermeable layer on the heat devlopable photosensitive layer. CONSTITUTION:An org. silver salt such as silver behenate is dispersed in ethanol and 10% aqueous gelatin soln. To the dispersion are added a silver halide such as silver bromide or a component forming a photosensitive silver salt and a reducing agent such as hydroquinone as well as a toning agent such as phthalazinone, an antifoggant such as mercuric acetate, a sensitizing dye, etc. The prepared coating liq. is coated onto base paper for photography, and polyvinylidene chloride, polystyrene, polyvinyl acetate or the like is coated onto the coated surface of the paper to form a water impermeable layer.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat-developable photosensitive material, and more particularly to a heat-developable photosensitive material with improved photographic properties such as sensitivity and maximum density.

The conventionally known photographic method using a photosensitive halogen system is superior to other photographic methods in terms of photosensitive liW tonality, image storage stability, etc., and is the most widely put into practical use.

However, in this method, wet processing is used for processing steps such as development, fixing, and water washing, which takes time and effort, and there are concerns about pollution to the human body due to the products being processed. There are many problems, such as concerns about contamination of rooms and workers with the above-mentioned chemicals, and consideration of pollution caused by waste liquid.

Therefore, there has been a demand for the development of a photosensitive material that uses photosensitive silver halide and can be dry processed.

Many proposals have been made regarding the above-mentioned dry processing photographic method, and among them, heat-developable photosensitive materials in which the developing step can be performed by heat treatment have attracted attention as photosensitive materials that meet the above-mentioned requirements.

Regarding such heat-developable photosensitive materials, for example,
It is described in No. 3-41j/ and Japanese Patent Publication No. 13-tI92II, and is a shoulder machine silver salt.

A photosensitive material comprising silver halide and a reducing agent is disclosed.

An example of using gelatin as a binder to increase the sensitivity of this heat-developable photosensitive material is, for example, US Patent @ 4'
, / t I, qr No. 0 specification, Tokuko Sho pp-
26! rlr, No. 2, As'-t, No. 2qoo, No. I
It is described in Japanese Patent Application Laid-open No. Ij-/11116, Japanese Patent Application Laid-open No. 52626, and Japanese Patent Application Laid-open No. 63-//4III.

That is, when gelatin is used as a binder in a heat-developable photosensitive material, it is possible to use a silver halide gelatin emulsion that has been made highly sensitive by various known methods. Higher sensitivity can be easily obtained than when using a binder. Furthermore, by using a high-sensitivity silver halide gelatin emulsion in a heat-developable photosensitive material, after heat development, the remaining silver halide can be fixed and removed using a normal fixing solution, thereby removing unexposed areas. It is also possible to prevent blackening due to silver printing out, and when the heat-developable photosensitive material is used as a color photosensitive material, it has advantages such as easy bleaching or bleach-fixing. However, when gelatin is used as a binder, since gelatin is not thermoplastic, the softening necessary to accelerate development does not occur at the temperatures required for thermal development, and when a thermoplastic binder is used, gelatin is not thermoplastic. It has the disadvantage that the progress of development is more significantly hindered than the conventional method, and it has the disadvantage that a black image cannot be obtained and the maximum density is low.

Therefore, an object of the present invention is to provide a heat-developable photosensitive material with high sensitivity and a high maximum density.

Another object of the present invention is to provide a photothermographic material from which a black image can be obtained.

The present inventors have conducted various studies to solve the above problem, and as a result, the present inventors have found that (a) an organic silver salt, (b) a photosensitive silver halide, (C) a reducing agent, and ((1) A heat-developable photosensitive material having at least one heat-developable photosensitive layer containing a binder, wherein the binder consists essentially of gelatin and/or a gelatin derivative, and a water-impermeable layer is provided on the heat-developable photosensitive layer. It has been found that the above object can be achieved using a developable photosensitive material.

It was surprising to the inventors, who have been involved in this field for many years, that the present invention significantly accelerates the development of heat-developable photosensitive materials using gelatin and/or gelatin derivatives as binders. The present inventor has not completely elucidated the salt mountain that significantly accelerates development, or perhaps by providing a water-impermeable layer in the above-mentioned light-sensitive material, water can be removed from gelatin during thermal development. This is thought to be because dissipation is prevented, and this moisture causes the gelatin to soften at the temperature during thermal development, exhibiting properties similar to those of a thermoplastic binder.

The amount of water necessary to impart these properties to gelatin is sufficient at the equilibrium water content contained in gelatin and the light-sensitive material at a relative humidity of ~100%, and this water is removed during thermal development. By preventing the loss of color due to evaporation or the like, it becomes possible to significantly increase sensitivity and maximum density, and to obtain images with a black tone.

The heat-developable photosensitive material of the present invention will be explained in more detail below. I will clarify.

Specific examples of substances used as the water-impermeable layer provided in the photothermographic material of the present invention include polystyrene, polyvinyl acetate, polyvinyl butyral, polyvinyl acetal, and polyvinyl fluoride.

Polyvinylpyrrolidone, polyvinyl chloride, polyethyl acrylate, polymethyl methacrylate, polyethyl methacrylate, polyvinylidene chloride, chlorinated polyethylene, chlorinated polypropylene, polycarbonate, polybutadiene, cellulose acetate.

Mention may be made of film-forming organic substances such as cellulose acetate butyrate, cellulose acetate propionate, ethyl cellulose, benzyl cellulose, cellulose acetate phthalate.

The above-mentioned water-impermeable layer can be formed by applying a solution of the film-forming organic substance dissolved in water or an organic solvent onto the photosensitive layer of the heat-developable photosensitive material, or by applying a dispersion (emulsion) of the film-forming organic substance. , latex, etc.), or a transparent polymer sheet made of a film-forming organic material is laminated onto the photosensitive layer, or the polymer sheet is photosensitive using, for example, a transparent adhesive sheet such as sellotape. It can be easily formed as a layer on the photosensitive layer by pressing onto the layer.

The thickness of the water-impermeable layer of the present invention is suitably 1 micron or more, preferably s micron or more.

These water-impermeable layers may be peeled off from the photosensitive layer after thermal development if necessary, and in such a case, a material that does not have very high adhesion to gelatin may be used as the layer-forming adhesive. It is necessary.

As an organic silver salt used in the thermal imitation material of the present invention, the Special Prince Sho Ga 3-119.2 /, the same Gu ψ -2TSRS, the same +! -/Ill/ No. 4 (J-/2700,
Samellll-22/I! No. i, JP-A-41+9-6262
No. 6, No. 12-3/7.2r, S2-/3732/
No. 32-/II/, No. 2.2-, No. 33-JG
jJ4j issue, same! No. 3-37610, U.S. Patent No. 3,3
No. 30,633, No. 3,79V.

Geta No. 4, same No. 10! ;,ll! ; / issue, same issue.

/23,2717, No. 1I, /4ff, 910
issue.

Silver salts of aliphatic carboxylic acids such as silver laurate, silver myristate, silver palmitate, silver stearate, silver arachidonate, silver behenate, α- (/-phenyltetrazolethio)silver acetate, etc.

Silver salts of aromatic carboxylic acids such as silver benzoate and phthalate, silver salts of organic compounds having imino groups such as silver benzotriazole, silver saccharin, silver phthalazinone, silver phthalimide, etc. of compounds having mercapto or thione groups. Silver salts such as λ-mercaptobenzoxazole silver, mercaptooxadiazole silver 9.2-mercaptobenzothiazole silver, 2-mercaptobenzimidazole silver.

3-mercapto-gouphenyl-/, 2. If-triazole silver, others≠-hydroxy-t-methyl-/, 3
．． 3PL, 7-chitrazaindene silver,! -Methyl-7-
Hydroxy/, 2, 3. ≠, 6-pentazaindene C, and the like.

Among the above organic silver salts, silver salts of aliphatic carboxylic acids are preferred, and silver salts of long-chain aliphatic carboxylic acids having a bromine atom number of /g to 33 are particularly preferred.

The photosensitive silver halide used in the present invention is as follows:
The photosensitive silver halides include silver chloride, silver bromide, silver iodide, silver chlorobromide, silver chloroiodide, silver iodobromide, silver chloride iodide 1, etc. It can be prepared by any method such as single jet method or double jet method,
Particularly in the present invention, a light-sensitive silver halide emulsion prepared according to a method including preparing a silver halide gelatin emulsion gives preferable 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 such as gold sensitization, sulfur sensitization, gold-sulfur sensitization, and reduction sensitization.

The silver halide in the above-mentioned photosensitive emulsion may be coarse grains or fine grains, but the preferred grain size is approximately S micron to approximately O, oo micron, more preferably approximately O. ,S microns to 9-about O,OS microns.

The light-sensitive silver halide emulsion prepared as described above can be applied to a layer containing light-sensitive silver halide, which is a constituent layer of the light-sensitive material of the present invention.

As another method for preparing photosensitive silver halide, it is also possible to allow a photosensitive silver salt-forming component to coexist with an organic silver salt to form photosensitive silver halide in a portion of the organic silver salt. The photosensitive silver salt forming component used in this preparation method includes an inorganic halide 9, for example, a halide represented by MXn (where M represents an H atom, an NH4 group, or a metal atom, and X represents CI).

Br or I%n is when M is a H atom or an NH4 group.

When M is a metal atom, its valence is shown. Metal atoms include lithium, sodium, potassium, rubidium,
Cesium, copper, gold, beryllium, magnesium, calcium, strontium, barium, zinc, cadmium,
Mercury, aluminum, potassium, indium, lanthanum, ruthenium, thallium, germanium, tin, lead, antimony, -/θ - bismuth, chromium, molybdenum, tungsten, manganese, rhenium, iron, cobalt, nickel, ruthenium,
Examples include rhodium, palladium, osmium, iridium, platinum, and cerium.

Halogen-containing gold (for example, 2Ptc16.K2
PtBr6゜HAuCl4. (NH4)2Ir(J6
．． (NH4), IrC1/6. (NH4)2Rue1
6゜(NH4), RuC16, (NH4), Rho/6
．． (NH4)5RhBr6 etc.), onium halide (
For example, μ-class ammonium halides such as tetramethylammonium furomite, trimethylphenylammonium bromide, cetylethyldimethylammonium bromide, 3-methylthiazolium bromide, trimethylbenzylammonium bromide, and V-class phosphants such as tetraethylphosphonium bromide. onium halides, benzylethyl methyl bromide, tertiary sulfonium halides such as l-ethylthiazolium bromide, etc.), halogenated hydrocarbons (e.g. iodoform, 1:1 mohom, carbon tetrabromide, λ-bromo), --Methylpropane $), N-halogen compounds (N-chlorosuccinimide, N-
Bromosuccinimide, N-bromphthalic acid imide, N
-bromoacetamide, N-iodosuccinimide, N
-bromphthalazinone, N-chlorophthalazinone, N-
Bromoacetanilide, N,N-dibromobenzenesulfonamide, N-bromo-N-methylbenzenesulfonamide, 3-dibromo-dimethylhydantoin, etc.), other halogen-containing compounds (e.g. triphenylmethyl chloride, odor) 1,1 phenylmethyl, 2-bromobutyric acid, λ-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 preferably 0.00/~/, 0-c-nyl per mol of organic silver salt. The sweetness is 0.0/~0.3 mol.

Furthermore, the reducing agent used in the present invention includes phenols (for example, p-phenylphenol, p-methoxyphenol, co-tert-butyl-p-cresol, N-methyl-p-aminophenol, etc.), Sulfonamidophenols (e.g. V-benzenesulfonamidophenol, -benzenesulfonamidophenol, !, d-dichlorobenzenesulfonamidophenol 1.2.4-dibromo-4'-(p-)
di- or polyhydroxybenzenes (e.g. hydroquinone, tert-butylhydroquinone, dimethylhydroquinone, chlorohydroquinone, carboxyhydroquinone, catechol, 3-carboxycatechol, etc.), naphthols (e.g. -su7thol, β-naphthol, Hiro-aminonaphthol, q-methoxynaphthol)
, Hydroxybinaphthyls and methylene bisnaphthol @
(For example, 1./'-dihydroxy-2..2'-binaphthyl, O, 6'-dibromo-, 2,,2'-dihydroxy-/, l'-binaphthyl, 6.t'-dinito 73-loose 1 .2'-dihydroxy-/, /'-binaphthyl, +, <Z'-dimethoxy-/, /'-dihydroxy-β2'-binaphthyl, bis(2-hydroxy-/-
(naphthyl) methane, etc.), methine/bisphenols (e.g. fil, /-bis(,
2-Hydroxy-3,s-dimethylphenyl)-3,!
;、! ;-) Limethylhexane, /,/-bis(2-hydroxy-3-tart-butyl-j-methylphenyl)methane, l,/-bis(2-hydroxy-3,j-di-tert-butylphenyl) Methane, 2. -methylenebis(,2-hydroxy-j-tert-butyl-
! -methylphenyl)-l-methylphenol, α-phenyl-α α-bis(,7-hydroxy-3,j-di-tert-butylphenyl)methane, α-phenyl-
α α-bis(2-hydroxy=J-tert-butyl-5-methylphenyl)methane, /, l-bis(,2
-hydroxy-3, dimethylphenyl) -2-methylpropane, /l/, yo, j-tetrakis (,2-7
-Hydroxy-3,5-dimethylphenyl)-,2゜ethylpentane, 2. ．． 2-bis(<<-hydroxy-J, s-dimethylphenyl)propane, 2゜2
-bis(cuhydroxy-3-methyl-yo-tert-
butylphenyl)propane, +2++2-bis(tI-
hydroxy-3,3-di-tart-butylphenyl)
propane, etc.), ascorbic acids, 3-pyrazolidones, pyrazolines, pyrazolones, hydrazones, and paraphenylenediamines.

Moreover, when hydrazones and paraphenylene diamines are used as reducing agents, US Patent No. 3,! ;3/,
, No. 21#, No. 3.7≦4t, Specifications of No. 321 and JP-A-Sho! ; t<-2 When used in combination with phenol-based, naphthol-based compounds and compounds having active methylene such as pyrazolone, pyrazolotriazole, indazole, pyrazolobenzimidazole, and pyrazoline as described in Publication No. 132, coloring can be achieved. An image is obtained.

The above-mentioned reducing agents can be used alone or in combination of two or more. The reducing agent used M depends on the type of organic silver salt used and the ELLs of other additives, but is usually 10 moles of O,OS per 1 mole of the organic silver salt, and is preferably The amount is 0.1 to 3 moles.

The binder used in the present invention consists essentially of gelatin and/or gelatin derivatives. The binder preferably comprises gelatin and/or a gelatin derivative, but in addition to these, water-soluble binders other than gelatin and gelatin derivatives, such as polyvinyl alcohol.

There is no problem even if polyacrylamide, carboxymable cellulose, etc. are contained within a range that does not impede the effects of the present invention, and such embodiments are also included in the present invention.

When dispersing the organic acid silver in gelatin and/or gelatin derivatives, water is used as the solvent, but in order to further improve the dispersibility, 5 g of B
It is preferable to use an organic solvent that is miscible with water within %i.
T-i.

The above organic solvents and [2] lower alcohols such as methanol, ethanol, isopropanol, and n-propanol, as well as acetone, methyl ethyl ketone, ethylene glycol, phlopylene glycol, chrycerin, ethylene glycol monomethyl ether, and ethylene glycol monomethyl Examples include ethyl ether and dioxane.

Furthermore, the use of surfactants is also effective in improving dispersibility.

As the surfactant in this case, any of anionic, cationic, amphoteric, and nonionic types are effective, but anionic surfactants such as alkylbenzene sulfonate and alkylnaphthalene sulfonate (4-) are particularly preferred.

The amount of the surfactant used is 0.0/
weight-it% to 10.0 weight l1%, preferably,
From 0.1% by weight to S, O% by weight.

A toning agent can be used in the heat-developable photosensitive material of the present invention for the purpose of blackening the image.

Examples of the above-mentioned color toning agents include, for example, JP-A No. 4/;-t077;
17- tIq-30/9, 119-! ;0.20, same 4'? -97,2/,! No. 107727, No. 1O-232I1, No. 3; 0-67/32, No. 30-67, No. q/, Same! ;0-//112/7 issue, same! r, No. 2-337.2.2, same! ;, 2-99113
No. 33-10.20, j-3-, t j /
/ 5-4, No. 33-10.20, Same! ;3-/,2
3;0/ll-'yha same J'l-/! ;t! ;, No. 23, same! r&-/! ; 4 j, 2 F, same! ;Hiroshi-/Jt! , 2! ; No., same! ;11-/3 Otsu Sj
J, 5r-Iloto, 3N-tlOt1,
Publications such as No. 1320/3 and West German Patent No. 2.
/IIO, No. 106, same No. 2. /II7,063, 2.2.20. tIr, U.S. Patent No. 3,010
．． ．． 23v No. 3.1117. t/- issue, same number 3,
No. 712,9111, No. 3.9 tag, No. 732, No. 3, /23. ．． No. 2g-, same No. G, Ko01. ! phthalimide, pyrazolone, quinazolinone, N-hydroxynaphthalimide, penzoxazine, naphthoxazinedione 1, ?, which are compounds described in the specifications of No. 12, etc. , J-dihydro-7talazinedione, 2.3--
7g - dihydro-/, 3-oxazine-2, goudione, oxypyridine, aminopyridine, hydroxyquinoline, aminoquinoline, isocarbostyryl, sulfonamide,
Examples include derivatives such as 2H-/, J-benzothiazine-,2,gu (3H) dione, penztriazine, mercaptotriazole, dimercaptotetrazabentalene, phthalic acid, naphthalic acid, phthalamic acid, and 7-taladinone.

Further, an antifoggant can be used to prevent thermal capping of the photothermographic material of the present invention.

As an antifoggant, for example, Tokko Sho F7-/l//3
No., Japanese Patent Application Publication No. 9-90//I, No. 119-10724
No. I, ll9-974/,? No. s.

-Toioiq No. 119-/30720, No. 10
-/ko3331, same j/-II7II/9, same j-
/-! ;71133, j/-71r, 227, 6l-10II331, 3-1m3, J 3
-209.23, 31-107 coj, same/-3
, 2, 23, same j/-da, 2jλ9, same 3l-II
/2II issue, same j'l-r/12/ issue, same S! ;-93
/11 de shouting publication and British Patent No. 1. It!
;! , 27/, U.S. Patent No. 3. l#! ;, TTR No. 3, 700, II! r7, same no. tl, /
No. 37,079, No. 37,079, No. 3, KotS, and West German Patent No. 2,617゜907. -halogenoacetamides, N-halogenosuccinic acids, perchlorates and their salts, inorganic peroxides, persulfates), acids and their salts (e.g. sulfinic acids, lithium laurates, rosins, diterpene acids, Thiosulfonic acid @=), sulfur-containing compounds (e.g. mercapto compound-releasing compounds, thiouracil, disulfide, simple sulfur, mercapto-/, j,!-) lyazole, thiazolinthione,
polysulfide compounds, etc.), others, oxazolines, /
, 2. II-) Compounds such as lyazole and phthalimide can be mentioned.

The heat-developable photosensitive material of the present invention may contain a compound that releases water upon heating, that is, a water-releasing agent.

Such water release agents include, for example, trisodium phosphate decahydrate, sodium sulfate decahydrate, ammonium iron sulfate hydrate, ammonium alum 21 hydrate, potassium alum 2
Compounds containing water of crystallization such as monohydrate magnesium acetate q hydrate and manganese acetate V hydrate are mentioned.

Further, the heat-developable photosensitive material of the present invention may contain a water-retentive compound for the purpose of keeping the water content in the photosensitive material constant. Such water-retentive compounds include, for example, U.S. Pat.
．． J17. Examples include polyalkylene oxide (Borig IJ Cole), hydroxyethyl cellulose, carboxymethyl cellulose, etc., which are described in the specification of No. J7J.

In addition to the above-mentioned components, the heat-developable photosensitive material of the present invention may optionally contain various known additives such as a spectral sensitizing dye, an antihalation dye, a printout inhibitor, and a non-mercury-based anticapri agent. be able to.

12/- The above-mentioned spectral sensitizing dyes include cyanine, merocyanine, rhodacyanine, etc., which are effective for halogenated emulsions.
Styrils and the like can be used.

Examples of the printout inhibitor include tetrabromobutane, tribromoethanol, s-7'romo-2-tolylacetamide, no-promo-2-tolylsulfonylacetamide%-2) riflomomethylsulfonylbenzothiazole1. l, u-bis(tribromomethyl)-6
-Methyltriazine, etc.

The support used in the heat-developable photosensitive material of the present invention includes:
Examples include synthetic plastic films such as polyethylene film, cellulose acetate film, and polyethylene terephthalate film, and papers such as photographic base paper, printing paper, baryta paper, and resin coated paper.

Each component used in the photosensitive material is coated on the support together with a binder dissolved in water or a mixture of water and an organic solvent. The thickness of the coating layer after drying is 1 to 1000 microns, preferably 3 to 20 microns. Furthermore, an overcoat layer may be formed on the photosensitive material, if necessary.

The heat-developable photosensitive material produced as described above is image-wise exposed as a photosensitive material as it is, and then the photothermographic material is usually heated at a temperature of 10°C to 200°C.
It is developed by heating for 1 to 60 seconds at a temperature range of . If necessary, preheating may be performed in a temperature range of 70° C. to 180° C. before exposure. Light sources used for the image exposure include tungsten lamps, fluorescent lamps, mercury lamps, and iodine lamps.

Examples include a xenon lamp, a CRT light source, and a laser light source.

In addition to the above-mentioned effects, the photothermographic material of the present invention has the advantage of less fogging at the same sensitivity compared to conventional photothermographic materials that use gelatin as a binder.

The present invention will be specifically explained below using Examples.

Example 1゜Toluene 1200m/! 2400 ml of water was added to a solution in which 54.4 F of behenic acid was dissolved, and the mixture was homogenized using a high-speed homogenizer. Add 27% silver nitrate to this solution.
, 400 ml of am% anionic silver nitrate aqueous solution containing 2 F
was added dropwise over 30 minutes while stirring while maintaining the temperature of the reaction solution at 60°C, and after further stirring for 30 minutes, the resulting crystals were filtered, washed with water, washed with methanol, and dried under reduced pressure. , O
Silver behenate of f was obtained.

Obtained silver behenate9. Of (approximately 0.02 mol),
Ethanol 200 tAt, 10% gelatin aqueous solution 100 ygl.

100 ml of water, 10% aqueous solution of Alkanol B (alkylnaphthalene sulfonate, manufactured by DuPont) Jr1
was added and subjected to ultrasonic dispersion to create a dispersion liquid.

While stirring this dispersion liquid, the following components were added in order to prepare a coating liquid.

(Ingredients) 1) Phthalazinone (Ik% methanol solution 12 kg)
)Mercuric acetate</**% methanol solution)/θva1 5) Silver bromide emulsion (emulsion/gelatin/, Of and silver 0
．． 3! Cubic emulsion with an average particle size of 002 microns containing f3 moles) 9*1 4) Sensitizing dye (merocyanine dye O, OS-
2g-5) Hydroquinone (5% by weight methanol solution) d The coating solution prepared in this manner was applied onto photographic base paper in such a manner that the pinning needles per 1 m2 were o and st to prepare a photothermographic material ( A) was created.

On the coated surface of this heat-developable photosensitive material (A), a water-impermeable layer of polyvinylidene chloride according to the present invention is further applied.
A photothermographic material (B) was prepared by applying a 0% acetone solution to a film thickness of S, 0 micron. A photothermographic material (0) was also prepared by applying a 5% acetone solution of chlorinated polyethylene in place of polyvinylidene chloride to a film thickness of 0 microns.

Photothermographic materials prepared in this way (A) (B)
and (0) were each exposed to white light through a step wedge. The exposure amount was given as ttoo OMS (2j-la-meter-second). Next, the film was developed by heating at /10'C for 70 seconds.

The results obtained are shown in Table 1.

Table l (The specific sensitivity shows the relative sensitivity when the sensitivity of the photosensitive material (1) without a water-impermeable layer is taken as 100.) From the above results, the photosensitive material according to the present invention has the highest density and sensitivity. It can be seen that both are clearly superior.

Example 2゜Penztriazole//, 91i' in methanol 100%
Silver nitrate/19 f was dissolved in 200 It.
(Dropped into a solution dissolved in water for S minutes. The resulting crystals were filtered, washed with water, further washed with methanol, and dried under pressure) to obtain IJ Azole Silver 2/, 01i'. .

Add 100 ml of 70% gelatin aqueous solution and 100 r of water to the obtained Penztriazole book Ljg (approximately 0.02 mol).
nt.

A dispersion liquid was prepared by ultrasonically dispersing a 70% aqueous solution of Alkanol B (alkylnaphthalene sulfonate, manufactured by DuPont).

While stirring this dispersion liquid, the following components were added in order to prepare a coating liquid.

(Components) 1) Phthalazinone (!r″ijl'E+% methanol solution) Cubic emulsion containing 0.333 mol of merocyanine and having an average particle size of 2 microns) 9 ml 4) Sensitizing dye (merocyanine dye of the following formula O, OS deuterium % methanol solution), 2.S translation! 5) Hydroquinone (j weight % methanol solution) 5rnt The coating solution prepared in this way was applied onto photographic base paper so that the amount of M per m2 was o, ty to form a photothermographic material. It was created.

On the coated surface of this heat-developable photosensitive material (T)), a coating of vinylidene chloride 7.
A 0% acetone solution was applied so that the film thickness was j, 0 microns, to prepare a heat-developable photosensitive material (g). A photothermographic material (F') was prepared by applying a t% acetone solution of chlorinated polyethylene instead of polyvinylidene chloride to a thickness of 0 microns.

Heat-developable photosensitive material (D) (g)) prepared in this way
and (F) were each exposed to white light through a step wedge. The exposure was given at /loo OMS (Canday 21 - La Meter Second) 3, then at 120°C and 70°C.
Developed by heating for 1 second.

The results obtained are shown in Table 1.

The sensitivity of Table 2 (specific sensitivity is for a light-sensitive material without a water-impermeable layer) is 1.
It shows the relative sensitivity when it is set to 00. ) From the above results, it can be seen that the photosensitive material according to the present invention is clearly superior in both maximum density and sensitivity.

Examples & Heat-developable photosensitive materials (A) and ■) of Examples 1 and 2
A transparent pressure-sensitive adhesive sheet (3M Wa Co., Ltd., Sue-Cotup Acetate Film Tape) was pressed onto the heat-developable photosensitive material (Q and ()), and each was exposed to white light through a step wedge.

With correction light/≦000MS (candela meter second)
gave. Next, the photosensitive materials fA) and (G) were added to I10'C
Photosensitive material (1) and (70 each at /20″C)
It was developed by heating for a second.

The results obtained are shown in Table 3 and Table V.

Table q (Specific sensitivities are for light-sensitive materials without water-impermeable layer (A), or (
The relative sensitivity is shown when the sensitivity of D) is set to 100. ) From the above results, it can be seen that the photosensitive material according to the present invention is clearly superior in both maximum density and sensitivity.

Agent Yoshi Kuwahara Procedural Amendment September 1980 241” Patent Application No. 114563 of 1980 2 Name of the invention: Heat-developable photosensitive material: (Supplementary + 1: Case and relationship) Patent applicant address: Tokyo Shinjuku-ku Nishi-Shinjuku 1-26-2 Lee name
Name (+27) Roku Konishi Photo] Nigyo Co., Ltd. Address 1-5 Sakura-cho, Hino-shi, Tokyo Date of amendment order] Self-initiated 6, "Detailed description of the invention" column 7 of the specification to be amended, Contents of the amendment (1) "Osnium" on page 11, line 3 of the specification is corrected to "osmium".

(2) ``And non-mercury-based antifoggant'' on page 21, lines 18 to 19, Y is deleted.

2-

Claims (1)

[Scope of Claims] A heat-developable material having, on a support, at least seven heat-developable photosensitive layers containing ta) an organic silver salt, (b) a photosensitive silver halide, (0) a reducing agent, and (d) a binder. In the photosensitive material, the binder is gelatin and/or
Alternatively, a heat-developable photosensitive material consisting essentially of a gelatin derivative and having a water-impermeable layer on the heat-developable photosensitive layer.