JPH022544A - Silver halide photographic sensitive material - Google Patents

Abstract

PURPOSE:To obtain the high contrast of the title material by incorporating a tetrazolium compd. composed of an anion part and a cation part in at least one layer of the hydrophilic colloid layers contd. in the photosensitive material, and by sulfurizing the anion part of the tetrazolium compd. CONSTITUTION:In the silver halide photographic sensitive material coated with at least one layer of the hydrophilic colloid layers (contg. a silver halide emul sion layer) on at least one surface of a supporting body, the tetrazolium compd. composed of the anion part and the cation part is incorporated in the hydrophilic colloid layer, and the anion part of the tetrazolium compd. is sulfu rized. Thus, the photosensitive material having the high contrast and the stable picture characteristics is obtd., even in a high temp. and a high humidity conditions using a developer having a good stability.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a silver mihalide photographic light-sensitive material, and more specifically, it is capable of producing images with high contrast using a stable developer, and is capable of being used under high temperature and high humidity conditions. This invention relates to a silver halide photographic material which has improved storage stability.

[Background of the invention]

Recently, in image processing using silver halide photographic materials, with the development of electronics, a method of outputting digital output from the silver halide photographic materials using laser light or light emitting diodes has become popular.

In order to operate such an image processing system stably,
There is a strong demand not only to improve the stability of processing solutions, but also to improve the stability of the photographic performance of silver halide photographic materials.

That is, it is desired that the above-mentioned photosensitive materials have long-term stability over time and further excellent storage stability under high temperature and high humidity conditions.

Conventionally, as a method to obtain high contrast, a photosensitive material consisting of a silver chlorobromide emulsion with relatively fine grains, a narrow particle size distribution, and a high silver chloride content is processed with an alkaline hydroquinone developer having a very low sulfite concentration. A method, the so-called Lith development method, is known.

However, when this method is used, the storage stability is extremely poor because the concentration of sulfite ions in the developer is low, and rapid processing is not possible because hydroquinone is used as a single active ingredient.

A photosensitive material that contains a super-additive developing agent that has good storage stability and can be processed quickly, and that can obtain high contrast by processing with a so-called PQ type or 111Q type developer that contains a relatively high concentration of sulfite. For example, a technique in which a tetrazolium compound is contained in a hydrophilic colloid layer on a support and treated with a superadditive type developer is disclosed in JP-A No. 52, for example.
-18317, 53-17719 and 53-1
No. 7720.

The method of obtaining a silver image with high contrast by processing a photosensitive material containing these oxidizing tetrazolium compounds with a superadditive type developer is an extremely innovative technology compared to the conventional technology.

However, the above-mentioned techniques have the disadvantage that the sensitivity fluctuates under conditions such as high temperature and high humidity, and the contrast decreases.

Further, when photographing a document through an intersection screen or a contact screen, particularly high contrast is required, and since the above-mentioned techniques do not always provide a sufficiently satisfactory contrast, improvements have been desired.

[Purpose of the invention]

The object of the present invention is, firstly, to produce a silver halide photographic light-sensitive material that can produce images with sufficiently high contrast even when processed using a stable developer that is resistant to autooxidation and has good storage stability. The second objective is to provide a 7% silver halide photographic material that has high contrast images and is stable even under high temperature and high humidity conditions.

[Structure of the invention]

The object of the present invention is to provide a silver halide photographic material comprising at least one hydrophilic colloid layer (including a silver halide emulsion layer) coated on at least one side of a support. This can be achieved by using a silver halide photographic light-sensitive material in which the hydrophilic colloid layer contains a tetrazolium compound consisting of an anion part and a cation part, and the anion part of the tetrazolium compound is converted into a sulfur atom.

However, the sulfur atom of the sulfonic acid group does not correspond to the sulfur atom of the present invention.

Hereinafter, the present invention will be explained in more detail.

The present invention is characterized in that a tetrazolium compound coated on a support and at least one hydrophilic colloid layer contains an anionic (sulfur-absorbed) tetrazolium compound; ±the following general formula CI),
(I[) or (III) shows the power (can be done).

General formula (In) In the formula, R+, Rs, R4, Rs, Rs, Re, R+a and R11 each represent an alkyl group (for example, a methyl group, a diqyl group, a propyl group, a dodecyl group, etc.), an alkenyl group (
(e.g. vinyl group, allyl group, propenyl group, etc.), aryl group (e.g. phenyl group, tolyl group, hydroxyphenyl group, carboxyphenyl group, aminophenyl group, mercaptophenyl group, α-naphthyl group, β-su7tyl group,
hydroxynaphthyl group, carboxynaphthyl group, aminonaphthyl group, etc.), and heterocyclic groups (e.g., thiazolyl group, penzothiγzolyl group, oxacylyl group, pyrimidinyl group,
It represents a group selected from (such as a lysyl group), and any of these may be a group that forms a metal chelate or a complex.

Rz, Rs and R2 each represent an allyl group, a phenyl group which may have a substituent, a naphthyl group which may have a substituent, a heterocyclic group, an alkyl group (for example, a methyl group, an ethyl group,
propyl group, butyl group, mercaptomethyl group, mercaptoethyl group, etc.), hydroxyl group, carboxyl group or its salt, alkoxycarbonyl group (e.g. methoxycarbonyl group, ethoxycarbonyl group, etc.), amino group (e.g. amino group, ethylamino group) , anilino group, etc.), a mercapto group, a nitro group, or a hydrogen atom,
D represents a divalent aromatic group, E represents a group selected from an alkylene group, an arylene group, an aralalkylene group, and Xθ
represents a sulfur atomized anion, and n represents an integer of l or 2. However, when the compound forms an inner salt, n is 1.

Next, specific examples of the cation moiety of the tetrazolium compound represented by the general formula (I), (n) or (I[[) will be shown, but the present invention is not limited to these.

Exemplary compounds: (1) 2-(benzothiazol-2-yl)-3-
Phenyl-5-dodecyl-2H-tetrazolium (2)
2.3-diphenyl-5-(4-t-octyloxyphenyl)-2H-tetrazolium (3) 2.3.54liphenyl-2H-tetrazolium (4) 2.3.5-1-ly(p-carboxy ethylphenyl)-2H-tetrazolium (5) 2-(benzothiazol-2-yl)-3-
Phenyl-5-(o-chlorophenyl)-2H-tetrazolium (6) 2.3-diphenyl-2H-tetrazolium (7) 2.3-diphenyl-5-methyl-2H-tetrazolium (8) 3-(p- Hydroxyphenyl)-5-methyl-2-phenyl-2H-tetrazolium (9) 2.3-diphenyl-5-ethyl-2H-tetrazolium (10) 2.3-diphenyl-5-n-hexyl-
2H-tetrazolium (11) 5-cyano-2,3-diphenyl-2H-
Tetrazolium (12) 2-(benzothiazol-2-yl)-5
-Phenyl-3-(4-tolyl)-2H-tetrazolium(13) 2-(benzothiazol-2-yl)-
5-(4-chlorophenyl)-3-(4-nitrophenyl)-2H-tetrazolium (14) 5-ethoxycarbonyl-2,3-di(3
-nitrophenyl)-2H-tetrazolium (15) 5-acetyl-2,3-di(p-ethoxyphenyl)-2H-tetrazolium (16) 2,5-diphenyl-3-(p-tolyl)-28-tetrazolium (17) 2.5-diphenyl-3-(p-iodophenyl)-28-tetrazolium (till) 2.3-diphenyl-5-(p-diphenyl)-214-tetrazolium (19) 5-(p-bromo phenyl)-2-phenyl-3-(2,4,6-)lychlorophenyl)-2H-
Tetrazolium (20) 3-(p-/\idroxyphenyl)-5
-(p-nitrophenyl)-2-phenyl-28-tetrazolium (21) 5-(3,4-dimethoxyphenyl)-3
-(2-ethoxyphenyl)-2-(4-methoxy7enyl)-2H-tetrazolium (22) 5-(4-cyanophenyl)-2,3-di7enyl-2H-tetrazolium (23 ) 3-(p-acetamidophenyl)-2,
5-Sif-nyl-2H-tetrazolium (24) 5-acetyl-2,3-diphenyl-2H
-tetrazolium (25) 5-(fluor-2-yl)-2,3-diphenyl-211-tetrazolium (26) 5-(thiec-2-yl)-2,3-diphenyl-28-tetrazolium (27) 2.3 -diphenyl-5-(pyrido-4-
yl)-2H-tetrazoliu A (28) 2.3-diphenyl-5-(quinol-2
-yl)-2[I-tetrazolium (29) 2.3-diphenyl-5-(penzoxazol-2-yl)-2H-tetrazolium (30)
2,3.5-tri(p-ethylphenyl)-2H-tetrazolium (31) 2.3.5-tri(p-allylphenyl)
-2H-tetrazolium (32) 2,3.5-tri(p-hydroxyethyloxyethoxyphenyl)-2H-tetrazolium (3
3) 2,3.5-)su(p-dodecylphenyl)-
2H-tetrazolium (34) 2,3.5-tri(p-benzylphenyl)-2H-tetrazolium Next, the anion part of the tetrazolium compound represented by the above general formula (1), (II) or (III) is as follows. General formula (
a), (b), (C), (d) or (e)
It can be expressed as

General formula (a) In the formula, Rlz represents an alkyl group having 1 to 32 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a hexyl group, a nonyl group, a dodecyl group, a hexadecyl group, etc. contains at least one sulfur atom. n is 1 to 3
represents an integer of 0 to 4, and n represents an integer of 0 to 4.

General formula (b) R,3-OCo-cH.

RIM 0CO-C1l RIM General formula (c) Rls -OCOC1b Rlz-OCOCR RIM 0COCH-R+s In the formula, R, , , R, , , R, , , R, and R1 each have 1 to 32 carbon atoms. A straight-chain or branched alkyl group, such as a methyl group, ethyl group, butyl group, isobutyl group, pentyl group, hexyl group, octyl group, nonyl group, decyl group, dodecyl group, octadecyl group, etc., but is cyclic. Alkyl groups may also be used, and these groups contain at least one sulfur atom. Also R 13. R141Rl@
+R+ and RIM each represent an aryl group, such as a phenyl group, a naphthyl group, etc., and these aryl groups contain at least one sulfur atom.

Further, R1 and R8 represent an acid group such as a carboxylad group, a sulfonate group or a phosphoric acid group.

General formula (d) In the formula, R8 represents a saturated or unsaturated linear or branched alkyl group having 1 to 32 carbon atoms, and examples of the saturated alkyl group include a methyl group, an ethyl group, a butyl group, It represents an isobutyl group, a hexyl group, a dodecyl group, an octadecyl group, etc., and as an unsaturated alkyl group, it represents, for example, an allyl group, a podenyl group, an octenyl group, etc. These saturated and unsaturated alkyl groups contain at least one sulfur atom.

R2 and n represent integers of 1 to 3. Also, n is O~6
represents an integer.

General formula (e) In the formula, Y is a sulfur atom, a selenium atom, an oxygen atom, a nitrogen atom, or a R12 group (where Rlz is a hydrogen atom or an N- alkyl group having 1 to 3 carbon atoms, such as a methyl group, an ethyl group Rtl represents a group having the same meaning as the group represented by R1□ in the general formula (a) or an aryl group containing at least one sulfur atom (eg, phenyl group, naphthyl group, etc.). In addition, Z represents an atomic group necessary to form a 5- or 6-membered heterocycle, examples of which include:
Thiazole ring, selenazole ring, oxazole ring, imidazole ring, 5-pyrazole ring, triazole ring, tetrazole ring, pyrimidine ring. Examples include triazine rings.

The above heterocycle may further have a substituent such as an alkyl group or an aryl group, and these substituents contain a sulfur atom.

Next, specific examples of the anion moiety of the tetrazolium compounds represented by the above general formulas (a) to (e) are shown in 2, but the compounds that can be used in the present invention are not limited to these.

Exemplary compound C.II.

Specific examples of the tetrazolium compound used in the present invention include all combinations of the above-mentioned specific examples of the cation moiety and specific examples of the anion moiety.

The tetrazolium compound in which the anion moiety is sulfur-atomized according to the present invention is synthesized from a potassium salt or sodium salt compound as seen in the above-mentioned exemplified compounds which are first sulfur-atomized and have a sulfur atom.

For example, JP 49-46733'), JP 50-1652
It can be synthesized by the method described in No. 5 and No. 51-32322.

It can be synthesized by mixing the potassium salt or sodium salt compound having a sulfur atomized anion moiety and the halide of the tetrazolium compound having a cation moiety according to the present invention.

Accordingly, in the present invention, a halide of a tetrazolium compound having a cation moiety and a potassium salt or sodium salt compound having a sulfurized anion moiety are added to a silver halide emulsion to form a hydrophilic colloid layer. Even if they are dispersed, they are mixed and integrated, so that the effects of the present invention, that is, high contrast and improved stability under high temperature and high humidity conditions can be obtained.

Furthermore, even if the above-mentioned recompounds having a cation moiety and an anion moiety according to the present invention are added separately, for example, one of them is added to a silver halide emulsion layer and the other is added to an adjacent layer, multilayer coating is possible. In this case, the recompounds undergo interdiffusion and are integrated by mixing, so the effects of the present invention can be obtained even in this case.

The tetrazolium compounds used in the present invention may be used alone or in combination of two or more in any ratio.

One preferred embodiment of the present invention is to add the tetrazolium compound according to the present invention to the silver emulsion layer. In another preferred embodiment of the present invention, it is added to a hydrophilic colloid layer directly adjacent to a hydrophilic colloid layer containing a silver halide emulsion layer, or to a hydrophilic colloid layer adjacent via an intermediate layer.

In another embodiment, the tetrazolium compound according to the present invention is dissolved in a suitable organic solvent, for example, alcohols such as methanol and ethanol, ethers, esters, etc., and a silver halide emulsion of a light-sensitive material is prepared by an overcoating method or the like. It may also be incorporated into the photosensitive material by directly applying it to the outermost layer of the layer side.

The tetrazolium compound according to the present invention contains I x 10 per mole of silver halide contained in the light-sensitive material of the present invention.
It is preferred to use a range from -' mol to 10 mol, especially from 2 x 10' t-ole to 2 x 10-' mol. No. 10 of photosensitive materials to which the present invention is applied.

The silver halide used in the silver emulsion layer may be any one used in ordinary silver halide photographic emulsions, such as silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide, silver chloride, etc. is included. In particular, when used as a photosensitive material exposed in a bright room using a printer using a metal halide or high-pressure mercury lamp as a light source, the halide #i composition consists essentially of silver chlorobromide containing 90 mol% or more of silver chloride. is preferred, but
In the case of ordinary ortho- or panchromatic-sensitized high-sensitivity darkroom photosensitive materials, those made of silver halide containing 60 mol % or more of silver chloride are suitable.

These silver halides may be coarse-grained or fine-grained, and can be prepared using any known method, such as that described in US Pat.
No. 592.250, No. 3.276.877, No. 3
．． 317.322, vg2,222.264+, 3.320.069, and 3,206.313, or the Journal of Ford Graphic Science (J, Phot, 5ci-
) J Vol. 12, No. 5 (September and October issue), 1964, pages 242-251, etc. It is also possible to mix and use silver halides prepared by different methods.

Although the silver halide contained in the silver halide emulsion layer of the present invention is not limited, the average grain size is 0.0.
5 to 1.5 microns, preferably O01 to 0.5 microns, and at least 75% of the total particle number, preferably 8
It is desirable that 0% or more contains silver halide having a grain size of 0.5 to 1.5@, preferably 0.6 to 1.4 times the average grain size.

According to one most preferred embodiment of the invention, the silver halide of the invention is 0. It has an average particle size of lO ~ 0.3 μl, and more than 80% of the total particles have an average particle size of 0.6 μl.
It is silver chlorobromide or silver chloroiodobromide having a grain size of ~1.4 times.

The silver halide used in the present invention can be sensitized with various chemical sensitizers. As a sensitizer,
For example, activated gelatin, sulfuric acid sensitizers (sodium thiosulfate, allylthiocarbamide, thiourea, allyl isothiacyanate, etc.), selenium sensitizers (N, N-dimethylselenourea, selenourea, etc.), reduction sensitizers (trisulfate, etc.), ethylenetetramine, stannic chloride, etc.), such as potassium chlorooleite, potassium aurithiocyanate, potassium chlorooleate, 2-oresulfobenzothiazole methyl chloride, ammonium chloroparadate, potassium chlorooleate, sodium chlorovaradite, etc. Various noble metal sensitizers represented by can be used alone or in combination of two or more. When using a metal sensitizer, rhodanammonium can also be used as an auxiliary agent.

In addition, iridium,
Atoms such as rhodium, osmium, bismuth, cobalt, nickel, palladium, ruthenium, iron, copper, zinc, lead, and cadmium may be contained. When these atoms are contained, the content is 10-'' to 1 per mole of silver halide.
It is preferable to contain per mole of O-2, especially 10-'
It is preferable to contain ~io-' moles.

Further, the silver halide emulsion used in the present invention may be of a surface latent image type or an internal latent image type.

Additionally, silver halides prepared by a variety of different methods may be mixed. The crystal shape may be cubic, octahedral, tetradecahedral, or spherical without any limitation.The silver halide and tetrazolium compounds according to the present invention are added to the hydrophilic colloid layer. The hydrophilic colloid particularly advantageously used in the present invention is gelatin, but hydrophilic colloids other than gelatin include, for example, colloidal albumin, agar, gum arabic, alginic acid, hydrolyzed cellulose acetate, acrylamide, and imidized polyamide. , polyvinyl alcohol, hydrolyzed polyvinyl acetate, gelatin derivatives, such as U.S. Pat.
phenylcarbamyl gelatin, acylated gelatin, phthalated gelatin as described in U.S. Pat. No. 2,548,520, U.S. Pat.
Styrene acrylate, acrylic ester, methacrylic acid, methacrylic m.
.

Examples include gelatin graft polymerized with a polymerizable monomer having an ethylene group such as an ester, and these hydrophilic colloids can be used as a layer containing no silver halide,
For example, it can be applied to anti-halogenation layers, protective layers, intermediate layers, etc.

The light-sensitive material of the present invention is formed by coating a hydrophilic colloid layer containing the above-mentioned silver halide and tetrazolium compound on a suitable photographic support. Examples of the support used in the present invention include baryta paper. Typical examples include polyethylene coated paper, polypropylene synthetic paper, glass plates, cellulose acetate, cellulose nitrate, polyester films such as polyethylene terephthalate, polyamide films, polypropylene films, polycarbonate films, polystyrene films, etc. These supports are appropriately selected depending on the intended use of the silver halide photographic material.

The light-sensitive material according to the present invention has at least one silver halide-containing hydrophilic colloid layer, that is, a silver halide emulsion layer, on at least one surface of the support, and includes a core layer. In at least one of the hydrophilic colloid layers on the layer side (hydrophilic colloid layers other than the silver halide emulsion layer include, for example, a protective layer, a subbing layer, a filter layer, an intermediate layer, etc.), there is a compound according to the present invention. Although it contains a tetrazolium compound, a protective layer having an appropriate thickness, that is, preferably a gelatin protective layer of 0.1 to 10 μm, particularly preferably 0.8 to 2 μm, is coated on the layer side. is desirable.

The hydrophilic colloid used in the present invention may contain various photographic additives, such as gelatin plasticizers, hardeners,
Surfactant, image stabilizer, ultraviolet absorber, antistain agent, pi adjuster, antioxidant, antistatic agent, thickener,
Graininess improvers, dyes, mordants, brighteners, development speed regulators, matting agents, and the like can be used within the range that does not impair the effects of the present invention.

Examples of the developer that can be included in the developer used in developing the photosensitive material of the present invention include the following.

Typical +l0-(CI-Ctl)n-OH type developers include catechol, pyrogallol and its derivatives, and ascorbic acid, as well as hydroquinone, chlorohydroquinone, bromohydroquinone, isopropylhydroquinone, toluhydroquinone, methylhydroquinone, .3-dichlorohydroquinone, 2.5
-dimethylhydroquinone, 2゜3-dibromohydroquinone, 2,5-dihydroxyacetophenone, 2,
5-diethylhydroquinone, 2.5-di-p-7enethylhydroquinone, 2.5-dibenzoylaminohydroquinone, catechol, 4-chlorocatechol, 3-
Phenylcatechol, 4-phenyl-catechol, 3-
Methoxy-catechol, 4-acetyl-pyrogallol-
Examples include 4-(2'hydroxybenzoyl)pyrogallol and sodium ascorbic acid.

In addition, typical lo-(CI1-CI)N-NHt type developers include ortho and para amine phenols or aminopyrazolones, including 4-aminophenol,
2. Amino-6-phenylphenol, 2-amino-4
-chloro-6-phenylphenol, 4-amino-2-
Phenylphenol, 3,4-diaminophenol, 3
-Methyl-4,6-diaminophenol, 2.4-cyamylsorcinol, 2.4.6-triaminophenol, N-methyl-p-aminophenol, N-β-hydroxyethyl-p-aminophenol, p-hydroxyphenylaminoacetic acid, 2-aminoacetic acid, and HzN (C=
C)n N11t type developers include, for example, 4-amino-2-methyl-N, N-diethylaniline, 2.4-
Diamino-N, N-diethylaniline, N-(4-amino-3-methylphenyl)-morpholine, p-phenylenediamine, 4-amino-N, N-dimethyl-3-hydroxyaniline, N N N 'N' -tetramethylparaphenylenediamine, 4-amino-N-ethyl-N
-(β-hydroxyethyl)-aniline, 1-amino-3-methyl-N-ethyl-N-(β-hydroxyethyl)-aniline, 4-amino-N-ethyl-(β-methoxyethyl)-3 -methyl-aniline, 4-amino-3
-Methyl-N-ethyl-N-(β-methylsulfonamidoethyl)-aniline, 4-amino-N-butyl-N-
γ-sulfobutylaniline, 1-(4-aminophenyl)-pyrrolidine; 6-amino-1-ethyl, Agents include, for example, tlfl
-Phenyl-3-pyrazolidone, l-phenyl-4-amino-5-pyrazolone, 1-(p-amino7enyl)-
Examples include 3-amino-2-pyrazoline, 1-phenyl-3-methyl-4-amino-5-pyrazolone, 5-aminouracil, and the like.

Other books include The Theory of the Photographic Process, 4th edition, by T. H. James.
ory or PI+otographic Proc
ess, Fourth Edition) m291~
334 pages and Journal of the American Chemical Society.
merican Chemical 5ociety)
The developer described in Vol. 73, *3, p. 100 (1951) can be effectively used in the present invention. These developers may be used alone or in combination of two or more types, but it is preferable to use two or more types in combination.The developer used in the present invention may also contain preservatives such as sodium sulfite, Even if sulfites such as potassium sulfite and ammonium sulfite are used, the effects of the present invention are not impaired and can be cited as one of the features of the present invention. Furthermore, hydroxylamine and hydrazide compounds may be used as preservatives. Others - adjustment of pi with caustic alkali, alkali carbonate, or amine used in general black and white developers, and provision of a buffer function; inorganic development inhibitors such as bromine; organic development inhibitors such as penttriazole; ethylenediaminetetraacetic acid, etc. metal ion scavenger,
Development accelerators such as methanol, ethanol, benzyl alcohol, and polyalkylene oxide, surfactants such as sodium alkylarylsulfonate, natural saponins, sugars or alkyl esters of the above compounds, and hardening agents such as glutaraldehyde, formalin, and glyoxal. It is optional to add ionic strength adjusting agents such as sodium sulfate and the like.

Hereinafter, the present invention will be explained in more detail with reference to Examples. The technical scope of the present invention is not limited in any way by the following examples, and various embodiments are possible.

〔Example〕

In particular, embodiments of the present invention will be explained using a high-sensitivity silver halide photographic light-sensitive material, a so-called darkroom type silver halide photographic light-sensitive material, but the present invention is not limited thereto in any way.

Example 1 A silver chlorobromide emulsion (containing 95 mol % silver chloride per mol silver) was prepared using a simultaneous mixing method.

An aqueous solution of silver nitrate and an aqueous solution containing sodium chloride and potassium bromide were continuously added to an aqueous gelatin solution at 60°C with stirring for 2 minutes to obtain an average particle size of 0.25μ.
m silver chlorobromide emulsion grains were formed.

After washing and desalting this emulsion, it was gold-sulfur sensitized at 50°C according to a conventional method, and then a 2-methyl-4-hydroxy-1,3,3a,7-tetrazaindene compound and gelatin were added as stabilizers. Aqueous solution was added.

Furthermore, 150 rag of the following compound as ortho-sensitizing dye
/silver mole added.

(Sensitizing dye) Next, 3 g of a 20% aqueous solution of saponin per mole of silver halide as a coating liquid auxiliary agent and 2 g of a styrene-maleic acid copolymer as a thickener were added to give a solution of 1.5 Q per mole of silver halide. After finishing, a coating solution was prepared.

This emulsion coating solution was divided into six parts, and a chloride salt of a tetrazolium compound having a cation moiety listed in Table 1 below was added to each part.

Next, a protective film coating solution for emulsion was prepared according to the following procedure.

(Preparation of protective film coating solution for emulsion) Add 10I2 of pure water to 1kg of gelatin, swell, and then warm to 40°C. Add amorphous silica gel with an average particle size of 3μ as a matting agent dispersed in 30g of gelatin. A protective film was prepared by finishing to 2oQ. This protective film solution was divided into six parts, and a sodium salt of a tetrazolium compound having an anion moiety shown in Table 1 below was added to each part. (Preparation of photosensitive material) The emulsion coating solution prepared above and the coating solution for a protective film were combined on a polyethylene terephthalate base support with a thickness of 100 μm that had been subjected to r drawing, and the amount of silver was 3.5 g.
/m'', gelatin was 1.5 g/+a'', and the amount of gelatin for the protective film was Ig/+s''.The coating conditions were a coating speed of 100 m/min, and a waning rate wet bulb of 24.
It was °C.

Six test samples as shown in Table 1 were thus obtained.

At the time of coating the protective film, two types of hardening agents, formaldehyde and ethyleneimine, were added in combination to the protective film coating solution to harden the film.

A backing solution having the following formulation was applied to the opposite side of the support from the emulsion-coated side, and at the same time, a protective layer having the following composition was applied thereon.

(Preparation of backing solution) Add 20Q of pure water to 1 kg of gelatin, and after swelling,
After heating to 0°C, add 10% aqueous solutions of compounds represented by the following structural formulas (a) and (b) as additives to 80% each.
Add 01 and 2% aqueous solution 4Q, and further add 5% aqueous solution 1,200 of a compound represented by the following structural formula (c) as a dye.
mQ and 16 g of styrene-maleic acid copolymer as a thickener and 16 g of saponin as a coating aid.
After adding pure water, finish to 30Q.

The pH of the coating solution was adjusted to 5.5 with sodium citrate,
The gelatin amount was applied at 1.8 g/m''.

Structural formula (a) So, Na Structural formula (b) So, Na Structural formula (c) (Preparation M of coating solution for protective film for backing) It was prepared in accordance with the protective film for emulsion in ordinary light-sensitive materials. The amount of gelatin applied was 1g7m2.

In Table 1, the test samples using the emulsion coating liquid and the protective film liquid are sequentially designated as Samples No. 001 to 6.

The above test sample was subjected to stepwise exposure with tungsten light according to a conventional method, and then processed in an automatic developing machine with a developing tank capacity of 40Q using a developer having the following formulation and a commercially available fixer.

[Development processing conditions]

(process) (ii degrees) (time)
Statue 30 '0 30
Fixed in seconds 〃 2
Wash with water for o seconds at room temperature
20 seconds [Developer composition] (Composition A) Pure water 150rIIQ
Ethylenediaminetetraacetic acid disodium salt
2g potassium sulfite (55% aqueous solution) 1
00m (potassium dicarbonate 50
g Hydroquinone 10g 5-methylbenzotriazole 200mg 1-phenyl-5-mercaptotetrazole 30mg Potassium bromide 2g (composition) Diethylene glycol 50g Pure water
3IIIQ Ethylenediaminetetraacetic acid disodium salt
25mg acetic acid (90% solution)
0.3rrr05-nitroindazole
110a+gl-phenyl-3-pyrazolidone
200mg potassium sulfite (55% aqueous solution)
When using a 1 mff developer, the above compositions were dissolved in 500 mQ of pure water in the order of composition 1 and finished to IQ before use.

For these test samples, in order to investigate the change in contrast immediately after application and after a certain period of time, the above test samples were conditioned at 25°C and 50% relative humidity, sealed in photographic barrier packaging material, and incubated at 50°C. Heat treated for 30 days.

(Comparative compound) II□C-C00CII ICH (C11□), CI+
.

NaO, S llc C00CToC1l(CIl
z)xcHsC2H.

In Table 1 above, the contrast is an indication curve with a density of 1.0.
It is a value representing the slope between each point to obtain 2.5 from .

From this table, it can be seen that the black and white silver halide photographic light-sensitive materials to which the compound of the present invention has been added have significantly higher contrast than the light-sensitive materials to which tetrazolium compounds other than the present invention have been added, and have been exposed to high temperatures and high humidity. It can be seen that even after long-term storage under low conditions, no change was observed in the contrast characteristics, indicating that it is stable.

On the other hand, a comparative sample (1) that does not contain a tetrazolium compound
It was also found that the image had a completely soft tone and could not be used as a lithographic photosensitive material for printing.

〔Effect of the invention〕

The photosensitive material containing the tetrazolium compound according to the present invention in the hydrophilic colloid layer can use a developer with good stability, has high contrast, and has stable image characteristics even under high temperature and high humidity conditions. It is a photosensitive material.

Claims (1)

[Claims] In a silver halide photographic material comprising at least one hydrophilic colloid layer (including a silver halide emulsion layer) coated on at least one side of a support, in at least one of the hydrophilic colloid layers. 1. A silver halide photographic material comprising a tetrazolium compound consisting of an anion part and a cation part, the anion part of the tetrazolium compound being converted into a sulfur atom.