JP3000182B2 - Silver halide photographic material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver halide photographic light-sensitive material having high sensitivity and low fogging, and more particularly, to a high-sensitivity silver halide emulsion coating solution having improved stagnation stability of a spectrally sensitized silver halide emulsion coating solution. It relates to a high sharpness, high contrast silver halide photographic material.

[0002]

BACKGROUND OF THE INVENTION Improvement and improvement of the sensitivity and image quality of silver halide photographic light-sensitive materials have been eternal research subjects for the related arts. Image quality is an essential requirement.

Therefore, it is necessary to increase the sensitivity and image quality of silver halide emulsions. A reduction sensitization method using a reducing substance, which is one of the conventional methods for sensitizing silver halide emulsions, is a method of forming silver nuclei having a small development activity on the surface and inside of silver halide by reduction treatment. It is known to be effective in preventing the recombination of photoelectrons and photoholes generated by light absorption, increasing the efficiency of converting photoelectrons into silver clusters (latent images), and increasing the sensitivity of silver halide emulsions. Has the effect of increasing Usually, as a means for increasing the sensitivity of a silver halide emulsion, other than the reduction sensitization method, a sulfur compound containing sulfur capable of reacting with silver ions, a sulfur sensitization method using active gelatin, and a noble metal compound such as gold are used. There is a method of using a noble metal sensitization method alone or a combination thereof. In particular, a gold / sulfur sensitization method using a gold sensitizer and a sulfur sensitizer in combination is said to be the most effective.

[0004] When a kind of reduction sensitization in which a gold-sulfur sensitized emulsion-coated sample is vacuum-degassed and then heat-treated in a hydrogen gas atmosphere is performed, a lower reduction sensitization than ordinary reduction sensitization is performed. It is also known that fog can provide a sensitizing effect, and is called a hydrogen sensitization method and used in astrophotography and the like. However, silver halide photographic emulsions whose sensitivity has been increased by reduction sensitization have a serious drawback in that the sensitivity is reduced during storage and softening occurs. Also, the hydrogen sensitization method has a disadvantage that the sensitizing effect is lost when the photographic material is left in the air after sensitization. Furthermore, in the prior art, when gold / sulfur sensitization is applied to the reduction-sensitized silver halide emulsion, the effect of increasing the sensitivity can be seen, but the storage stability is essentially poor, and after the photosensitive material is manufactured, Before use, photographic performance deteriorated with time, such as an increase in fog and a decrease in sensitivity. On the other hand, when a sensitizing dye was added to the silver halide emulsion for spectral sensitization, the dye was desorbed during the stagnation of the coating solution, and the spectral sensitivity was considerably reduced. Generally, in the mass production of silver halide photographic light-sensitive materials, the stagnation time from the production of an emulsion coating solution to the end of coating in the production process usually takes a long time, so that fog increases and sensitivity decreases. Inevitably occurred.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the stagnation stability of an emulsion coating solution in the production process of a silver halide photographic light-sensitive material, and to provide a silver halide photographic light-sensitive material having high sensitivity, high sharpness and high contrast. Is to provide the material.

[0006]

The object of the present invention is to provide a silver halide photographic light-sensitive material having at least one tabular silver halide emulsion layer having an aspect ratio of 2.0 or more on a support, wherein the silver halide emulsion is (1) having a reduced portion in the interior of the particle, further (2) containing at least one iron compound in the interior and / or surface of the particle, and (3) less than 5 mol% of the outermost shell layer of the particle A silver halide grain comprising silver iodide, wherein the silver halide emulsion has the following general formula (I):
This is achieved by a spectrally sensitized silver halide photographic material with at least one of the dyes represented by [II] or [III].

[0007]

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In the general formula (I), specific examples of the substituted or unsubstituted alkyl group represented by R ₁ , R ₂ and R ₃ include lower alkyl groups such as methyl, ethyl, propyl and butyl. Can be.

Examples of the substituted alkyl group substituted for R ₁ , R ₂ and R ₃ include 2-hydroxyethyl and 4-hydroxybutyl as hydroxyalkyl groups, and 2-acetoxyethyl and 3-acetoxybutyl as acetoxyalkyl groups. Groups, such as 2-carboxyethyl, 3-carboxypropyl, 2- (2-carboxyethoxy) ethyl groups as carboxyalkyl groups, and 2-sulfoethyl, 3-sulfopropyl, 3-sulfobutyl, 4-sulfobutyl, Examples thereof include a 2-hydroxy-3-sulfopropyl group.

The alkenyl groups represented by R ₁ , R ₂ and R ₃ include allyl, butynyl, octenyl and oleyl groups. Further, examples of the aryl group represented by R ₁ , R ₂ and R ₃ include a phenyl and carboxyphenyl group.

However, as described above, at least one of R ₁ and R ₃ is a sulfoalkyl group or a carboxyalkyl group.

[0012] In the general formula [I] X ₁ ^- Examples of the anion represented by, for example, chloride, bromide,
Examples thereof include iodine ion, thiocyanate ion, sulfate ion, perchlorate ion, p-toluenesulfonic acid ion, and ethyl sulfate ion.

Next, typical specific examples of the compound represented by the general formula [I] will be shown, but the present invention is not limited thereto.

[0014]

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[0015]

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[0016]

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The dyes represented by the general formula [I] of the present invention include, in addition to the specific examples described above, for example, Japanese Patent Application No. 2-11127.
No. 8, page 9 to page 19 of the compound examples, I-1, I-4, I-6, I-7, I-9 to I-13, I-1
5, I-16, I-I8 to I-21, I-24 to 33, I-35 to 40 and the like can be used.

[0018]

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Next, in the above general formula [II], R ₅ represents a hydrogen atom, a lower alkyl group or an aryl group. Examples of the lower alkyl group include methyl, ethyl, propyl and butyl. Examples of the aryl group include, for example, a phenyl group.

Examples of R ₄ and R ₆ include those exemplified as R ₁ and R ₃ in the general formula [I] in the general formula [I].

The anion of X ₂ ^- is also the same as that of the above-mentioned general formula [I].
₁ ^- those exemplified as the like.

Next, typical specific examples of the compound represented by the general formula [II] are shown, but the present invention is of course not limited to these examples.

[0023]

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[0024]

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As the dye represented by the general formula [II] of the present invention, in addition to the specific examples described above, for example, Japanese Patent Application No. 2-11127.
Nos. II-3, II-4, II-6, II-7, II-8, II-1 of the compound examples described on pages 20 to 28 of the specification
0, II-13, II-14, II-16, II-17, II-18, II-2
0, II-21, II-24 to II-44 can be used.

[0026]

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Next, in the general formula [III], R ₇ , R
Examples of the lower alkyl group ₉ include groups such as methyl, ethyl, propyl, and butyl. Examples of the substituted alkyl group include the groups exemplified as R _{1 to} R ₃ in the general formula [I].

Examples of the lower alkyl group for R ₈ and R ₁₀ are the same as those for R ₇ and R ₉ . Examples of the hydroxylalkyl group, sulfoalkyl group and carboxyalkyl group of R ₈ and R ₁₀ include the groups exemplified as R _{1 to} R ₃ in the general formula [I].

[0029] X ₃ ^- can be those exemplified as ^- X ₁ anion also general formula [I] of.

Representative specific examples of the compound represented by the general formula [III] are as follows.

Of course, in this case, the present invention is not limited by this example.

[0032]

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The dyes represented by the general formula [III] of the present invention include, in addition to the specific examples described above, for example, Japanese Patent Application No. 2-1112.
The compound examples III-1, III-5 and III-7 described on page 29 to page 31 of the specification of No. 78 can be used. The sensitizing dye represented by the above general formula used in the present invention is F.
“Heterocycrlic compounds Cyaninedyes and
related compounds ”(heterocyclic compounds-cyanine soybeans and relayed compounds) IV. V.VI, chapters 89-199 John wiley & sons (new yok.london), 1964, or DMSturmer“ He
terocycrlic compounds special topics in Heterocycr
lic chemistry ”(heterocyclic compounds-special topics in heterocyclic)
Chemistry) Chapter VIII IV.482-515 John Wiley & son
The compound can be easily synthesized based on the method described in s Company (new yok london), published in 1977.

It is to be noted that any of the above general formulas merely shows one state of the resonance structure, and means the same substance even when expressed in an extreme state in which + charge enters a symmetric heterocyclic nitrogen atom. It is.

The above-mentioned spectral sensitizing dyes are added individually or in combination to obtain a desired spectral sensitivity.

The amount of the dye represented by the general formula is not uniform depending on the kind of the dye and the emulsion conditions, but is preferably from 10 mg to 900 mg, more preferably from 60 mg to 600 mg per mol of silver halide.

In addition to these spectral sensitizing dyes, a dye which does not itself have a spectral sensitizing effect, or a substance which does not substantially absorb visible light and has a supersensitizing effect is added to the emulsion. May be added.

The spectral sensitizing dye according to the present invention is added during the nucleation step of the silver halide emulsion according to the present invention to the end of the desalting step, whereby the spectral sensitizing efficiency is excellent. A high-sensitivity silver halide emulsion is obtained,
Further, the present invention relates to the same or a different kind of the dye added to the above-mentioned step (from the nucleation step to the end of the desalting step) at any time from the end of the desalting step to just before the coating step after the chemical ripening step. A spectral sensitizing dye may be additionally added. The preferred timing of addition is during the chemical ripening step, particularly preferably at the start of chemical ripening.

The reduction treatment in the present invention, so-called reduction sensitization, is called a method of adding a reducing compound, called silver ripening.
Method for passing silver ion excess of pAg = 1 to 7, high p
It is applied to a silver halide emulsion by a method called H ripening which allows a high pH state of pH = 8 to 11 to elapse. Also, these two or more methods can be used in combination.

The method of adding a reducing compound is preferable because the degree of reduction sensitization can be finely adjusted.

The reducing compound may be any of inorganic or organic compounds, such as thiourea dioxide, stannous salts, amines and polyamines, hydrazine derivatives, formamidine sulfinic acid, silane compounds, borane compounds, ascorbic acid and Derivatives, sulfites and the like,
Particularly preferred are thiourea dioxide, stannous chloride and dimethylamine borane. The amount of these reducing compounds to be added varies depending on the reducibility of the compounds, the type of silver halide, and emulsion production conditions such as dissolution conditions, but is from 1 × 10 ⁻⁸ to 1 × 10 ⁻² mol per mol of silver halide. Is appropriate. These reducing compounds are dissolved in an organic solvent such as water or alcohols, and added during the growth of silver halide grains.

In the present invention, "having a reduced portion inside" means that any portion other than the outermost shell layer of the silver halide grain and / or the shell layer is subjected to a reduction treatment, and the grain is further grown as it is. From the viewpoint of controlling the effect, it is preferable to apply it to the surface of the inner shell layer which is multi-layered, for example, to the surface of seed emulsion grains or to the surface of the shell layer when growth is stopped.
It is preferable that the reducing compound is added at an appropriate time during the grain growth, and that the reducing compound is added to a water-soluble silver salt and / or a water-soluble halide solution in advance, and the aqueous solution is used to prepare silver halide. The particles may be allowed to settle. It is also a preferable method to add the reducing compound addition solution in several portions as the silver halide grains grow, or to continuously add the solution for a long time.

The reduction treatment in the present invention is described in JP-A-2-354.
The reaction may be carried out in the presence of a thiosulfonic acid compound shown in JP-A Nos. 39 and 2-136852 and the like.

In addition to the reduction sensitization according to the present invention, chemical sensitization includes sulfur sensitization, gold sensitization, sensitization with noble metals of Group VIII of the periodic table (eg, Pd, Pt, Id, etc.) A sensitization method by a combination can be used. Among them, it is preferable to use a combination of gold sensitization and sulfur sensitization (gold / sulfur sensitization). In the silver halide emulsion according to the present invention, it is particularly preferable to carry out reduction sensitization in combination with gold / sulfur sensitization.

By adding an iron compound to the silver halide emulsion according to the present invention having a portion reduced inside the grain, it is possible to increase the sensitivity and contrast of the spectrally sensitized silver halide emulsion. It was further found that the emulsion coating solution had a surprising effect on the stagnant stability of photographic performance.

The iron compounds used in the present invention include ferrous arsenate, ferrous bromide, ferrous carbonate, ferrous chloride, ferrous citrate, ferrous fluoride, and formic acid. Ferrous, ferrous gluconate, ferrous hydroxide, ferrous iodide, ferrous lactate, ferrous oxalate, ferrous phosphate, ferrous succinate, ferrous sulfate, thiocyanate Ferrous acid, ferrous nitrate, ammonium ferrous nitrate, ferric acetate basic, ferric albumate, ammonium ferric acetate, ferric bromide, ferric chloride, ferric chromate Iron, ferric citrate, ferric fluoride, ferric formate, glycero / ferric phosphate, ferric hydroxide, ferric acid phosphate, ferric nitrate, ferric phosphate Iron, ferric pyrophosphate, sodium ferric pyrophosphate, ferric thiocyanate, ferric sulfate, ammonium ferric sulfate, guanidine ferric sulfate, citric acid Ferric ammonium hexacyanoferrate (II), potassium hexacyanoferrate (II), ferrous potassium pentacyano ammine, sodium ferric ethylene dinitrilo tetraacetic acid, hexacyanoferrate (II
I) Potassium acid, ferric tris (dipyridyl) chloride, ferric potassium pentacyanonitrosyl, ferric hexaurea chloride, etc., and hexacyanoferric (III)
Potassium and potassium hexacyanoferrates (II) are preferred. The addition amount of the iron compound is suitably from 1 × 10 ⁻⁹ to 1 × 10 ⁻² mol, preferably from 1 × 10 ⁻⁷ to 1 × 10 ⁻⁴ mol per mol of silver halide finally formed. Is a mole.

The iron compound according to the present invention can be added at any step during the formation of the silver halide grains, and the core of the silver halide grains according to the present invention having a reduced portion or shell layer therein. In the case of the / shell-structured particles, they can be added at any step during the formation of the particles, but are preferably localized in the shell portion.

The average grain size of the tabular silver halide grains according to the present invention is preferably from 0.3 to 3.0 μm, particularly preferably from 0.5 to 3.0 μm.
1.5 μm.

The tabular silver halide emulsion of the present invention has an average value (called average aspect ratio) of grain diameter / thickness (called as aspect ratio) of 2.0 or more, and preferably 2.2 to 2
0.0, particularly preferably 2.5 to 10.0.

The average thickness of the tabular silver halide emulsion of the present invention is preferably 0.5 μm or less, particularly preferably 0.3 μm or less.

The advantage of such tabular grains is that they can improve the spectral sensitization efficiency, improve the graininess and sharpness of the image, etc., for example, in UK Patent 2,112,157 and US Patent 4,439,5.
Nos. 20,433,048, 4,414,310, and 4,434,226, and emulsions can be prepared by the methods described in these specifications.

In the present invention, the diameter of a silver halide grain is defined as the diameter of a circle having an area equal to the projected area of the grain from observation of an electron micrograph of the silver halide grain.

In the present invention, the thickness of the silver halide grains is defined as the minimum of the distance between two parallel planes constituting the tabular silver halide grains.

The thickness of the tabular silver halide grains can be determined from an electron micrograph with a shadow of the silver halide grains or an electron micrograph of a sample slice obtained by coating a silver halide emulsion on a support and drying. .

To determine the average aspect ratio, the minimum
Measure 100 samples.

In the silver halide emulsion of the present invention, the ratio of tabular silver halide grains to all silver halide grains is at least 50%, preferably at least 60%, particularly preferably at least 70%.

The tabular silver halide emulsion of the present invention is preferably monodisperse, and the average grain size is ±
50% by weight of silver halide grains contained in the 20% particle size range
The above are particularly preferably used.

The tabular silver halide emulsion of the present invention may have any halogen composition such as silver chloride, silver bromide, silver iodide, silver chlorobromide, silver iodobromide, etc. Silver halide is preferred, and the average silver iodide content is 0.1 to 4.0 mol%, particularly preferably 0.5 to 3.0 mol%.

The tabular silver halide emulsion of the present invention comprises:
The halogen composition may be uniform in the grains or silver iodide may be localized, but those localized in the center are preferably used.

The method for producing tabular silver halide emulsions is described in JP-A-58-113926, JP-A-58-113927, JP-A-58-113934 and JP-A-58-113934.
2-1855, European Patents 219,849 and 219,850 can also be referred to.

As a method for producing a monodisperse tabular silver halide emulsion, JP-A-61-6643 can be referred to.

As a method for producing a tabular silver iodobromide emulsion having a high aspect ratio, an aqueous silver nitrate solution or an aqueous silver nitrate solution and an aqueous halide solution are simultaneously added to an aqueous gelatin solution having a pBr of 2 or less to form seed crystals. And then grown by the double jet method.

The size of the tabular silver halide grains can be controlled by the temperature during grain formation and the rate of addition of the silver salt and the aqueous halide solution.

The average silver iodide content of the tabular silver halide emulsion can be controlled by changing the composition of the aqueous halide solution to be added, that is, the ratio of bromide to iodide.

In the production of tabular silver halide grains,
If necessary, silver halide solvents such as ammonia, thioether, and thiourea can be used.

The silver halide emulsion according to the present invention includes:
Core / shell type or double structure type grains having a silver halide composition different from the inside and the surface of the grains are preferably used. As a method for obtaining a core / shell emulsion, for example, US Pat. Nos. 3,505,068 and 4,444,877, and British Patent 1,02
No. 7,146, JP-A-60-14331 and the like. In the core / shell type grains of the silver halide emulsion according to the present invention, the outermost shell layer of the grains has a silver iodide content of less than 5 mol%, preferably less than 3 mol%.

The silver iodide content of the outermost shell layer of the silver halide grains of the present invention can be detected by various surface elemental analysis means. It is useful to use a method such as XPS (X-ray Photoelectron Spectroscopy), Auger electron spectroscopy, or ISS. XPS is the simplest and most accurate means, and the silver iodide content of the outermost layer of the present invention can be defined by the value measured by this method.

It is said that the depth analyzed by the XPS surface analysis method is about 10 °. Regarding the principle of the XPS method used to analyze the iodine content near the surface of silver halide grains, Junichi Aihara et al., “Electron spectroscopy” (Kyoritsu Library 1
6, published by Kyoritsu Shuppan, 1978).

The above-mentioned emulsions are either a surface latent image type for forming a latent image on the grain surface, an internal latent image type for forming a latent image inside the grain, or a type for forming a latent image on the surface and inside. You may. These emulsions may use a cadmium salt, a lead salt, a zinc salt, a thallium salt, a ruthenium salt, an osmium salt, an iridium salt or a complex salt thereof, a rhodium salt or a complex salt thereof at the stage of physical ripening or grain preparation.

The emulsion may be subjected to a water washing method such as a Nudel washing method or a flocculation sedimentation method to remove soluble salts. As a preferred washing method, for example,
As a particularly preferable desalting method, a method using an aromatic hydrocarbon aldehyde resin containing a sulfo group described in 35-16086, or a method using G3, G8 or the like as an agglomerated polymer agent described in JP-A-63-158644 is used. No.

In the emulsion according to the present invention, various photographic additives can be used before and after physical ripening or chemical ripening. Known additives include, for example, Research Disclosure (RD) No. 17643 (December 1978)
No. 18716 (November 1979) and No. 308119 (198
9 / Dec. 9). The types of compounds and the locations described in these three research disclosures are listed below.

Additive RD-17643 RD-18716 RD-308119 page Classification page Classification page Classification Chemical sensitizer 23 III 648 Upper right 996 III Sensitizing dye 23 IV 648-649 996-8 IV Desensitizing dye 23 IV 998 B Dye 25-26 VIII 649-650 1003 VIII Development accelerator 29 XXI 648 Upper right Fog inhibitor / stabilizer 24 IV 649 Upper right 1006-7 VI Brightener 24 V 998 V Hardener 26 X 651 Left 1004-5 X Surface activity 26 to 7 XI 650 right 1005 to 6 XI Antistatic agent 27 XII 650 right 1006 to 7 XIII Plasticizer 27 XII 650 right 1006 XII sliding agent 27 XII matting agent 28 XVI 650 right 1008 to 9 XVI binder 26 XXII 1003 to 4 IX support 28 XVII 1009 XVII Examples of the support that can be used in the light-sensitive material according to the present invention include the above-mentioned RD-17643, page 28 and RD-308119, 100.
What is described on page 9 is mentioned.

A suitable support is a plastic film or the like. The surface of the support may be provided with an undercoat layer, or subjected to corona discharge, ultraviolet irradiation, etc. in order to improve the adhesion of the coating layer.

[0074]

Embodiments of the present invention will be described below. However, needless to say, the present invention is not limited to the embodiments described below.

Example 1 (Preparation of spherical seed emulsion) A monodisperse spherical seed emulsion was prepared by the method described in JP-A-61-6643.

A1 Ossein gelatin 150 g Potassium bromide 53.1 g Potassium iodide 24 g Water 7.2 L B1 Silver nitrate 15000 g Water 6 L C1 Potassium bromide 1327 g 1-Phenyl-5-mercaptotetrazole (dissolved in methanol) 1.2 g Water 3 L D1 ammonia water (28%) 705 ml The B1 solution and the C1 solution were added to the A1 solution stirred vigorously at 40 ° C. for 30 seconds by a double jet method to generate nuclei.
The pBr at this time was 1.09 to 1.15.

After 1 minute and 30 seconds, solution D1 was added in 20 seconds and ripened for 5 minutes. During ripening, the KBr concentration was 0.071 mol / l, and the ammonia concentration was 0.63 mol / l.

Thereafter, the pH was adjusted to 6.0, and desalting and washing were immediately performed. When this seed emulsion was observed with an electron microscope, it was a monodisperse spherical emulsion having an average particle size of 0.26 μm and a distribution width of 18%.

(Preparation of Growth Emulsion) EM-1 The obtained spherical seed emulsion was used in an amount of 0.14 mol per mol of silver of the growth emulsion and contained sodium salt of polypropyleneoxy-polyethyleneoxy-disuccinate at a liquid temperature of 65 ° C. After dissolving and dispersing in an aqueous gelatin solution (Step A),
Dimethylamine borane was added at 1 × 10 ^-5 mole per mole of silver in the final silver halide emulsion. Subsequently, the final average silver iodide content is 2.25 mol%
A silver nitrate solution and a potassium bromide / potassium iodide halide solution prepared so as to have pH = 2.0, pAg = 8.0, 65
While maintaining the whole temperature at 0 ° C., the mixture was added over 45 minutes by the controlled double jet method (step B), and the average particle size was 1.22 μm.
Thus, a tabular silver iodobromide emulsion EM-1 having an average thickness of 0.29 μm and an aspect ratio of 4.2 was obtained.

EM-2 After step A, dimethylamine borane was added so as to be 1 × 10 ^-5 mol per mol of silver of the finally formed silver halide emulsion, and a silver nitrate solution, potassium bromide and iodine were added. While maintaining the potassium halide and the halide solution at pH = 2.0 and pAg = 8.0 throughout, the controlled double jet method was used.
Added in 31 minutes (step B '), average grain size 0.95 μm, average thickness 0.28 μm, aspect ratio 3.4, average silver iodide content 2.3
% Of tabular silver iodobromide emulsion was obtained. Using this emulsion as a core, a silver nitrate solution and a potassium bromide solution were further continuously added.
H = 2.0, pAg = 8.0, added in 13 minutes by the controlled double jet method (Step C), and the average particle size was 1.20 μm.
A tabular silver iodobromide emulsion EM-2 having an average thickness of 0.29 μm and an outermost shell layer of pure silver bromide having an aspect ratio of 4.1 was obtained.

EM-3 except that after step B, but not after step A, dimethylamine borane was added at 1 × 10 ^-6 mole per mole of silver in the final silver halide emulsion. EM-2
Average particle size 1.20μm, average thickness 0.29μ
m, and a tabular silver iodobromide emulsion EM-3 having an aspect ratio of 4.1 were obtained.

EM-4 K ₄ [Fe (CN) ₆ ] .3H ₂ O is added to the halide solution in step B at 2 × 2 mol / mol of silver of the silver halide emulsion finally formed.
A tabular silver iodobromide emulsion EM-4 having an average particle size of 1.22 μm, an average thickness of 0.29 μm, and an aspect ratio of 4.2 was obtained in the same manner as in EM-1 except that it was added to 10 ^-6 mol. .

EM-5 K ₄ [Fe (CN) ₆ ] .3H ₂ O is added to the halide solution in the step B ′ at 2 mol / mol silver of the silver halide emulsion finally formed.
A tabular silver iodobromide emulsion EM-5 having an average particle size of 1.20 μm, an average thickness of 0.29 μm, and an aspect ratio of 4.1 was obtained in exactly the same manner as in EM-2 except that it was added so as to be × 10 ⁻⁶ mol. Was.

EM-6 K ₄ was added to the halide solution comprising potassium bromide in Step C.
Except that [Fe (CN) ₆ ] .3H ₂ O was added in an amount of 2 × 10 ⁻⁶ mol per mol of silver in the finally formed silver halide emulsion, the same method as in EM-3 was used. A tabular silver iodobromide emulsion EM-6 having an average particle size of 1.20 μm, an average thickness of 0.29 μm, and an aspect ratio of 4.1 was obtained.

The emulsions EM-1 to EM-6 were desalted by a conventional method and then redispersed at 40 ° C. under the conditions of pAg 7.8 and pH 5.85. Subsequently, these emulsions were optimally sensitized with gold and sulfur using ammonium thiocyanate, chloroauric acid and sodium thiosulfate.

Prior to the gold / sulfur sensitization, a methanol solution of the spectral sensitizing dye according to the present invention shown in Tables 1 to 4 was added to perform spectral sensitization. After sensitization, 4-hydroxy-6-methyl-1,3,
It was stabilized by adding 3a, 7-tetrazaindene so as to give 1.0 g per mol of silver.

The resulting emulsion was added with the additives described below to prepare an emulsion layer coating solution. At the same time, a coating solution for a protective layer described below was prepared. The amount of silver per side was 2.0 g / m ² , and the amount of gelatin was 3.1 g / m ² with two slide hopper coaters at a speed of 80 m / min. The sample was applied and dried in 2 minutes and 20 seconds to obtain a sample. As a support, an aqueous dispersion of a copolymer obtained by diluting a copolymer composed of three monomers of glycidyl methacrylate 50% by weight, methyl acrylate 10% by weight, and butyl methacrylate 40% by weight so as to have a concentration of 10% by weight was used. 175μm used as eluent
A polyethylene terephthalate film base colored blue at a concentration of 0.15 for an X-ray film was used.

The additives used in the emulsion are as follows.
The amount of addition is shown in an amount per mole of silver halide.

1,1-dimethylol-1-bromo-1-nitromethane 70 mg t-butyl-catechol 400 mg polyvinylpyrrolidone (molecular weight 10,000) 1.0 g styrene-maleic anhydride copolymer 2.5 g nitrophenyl-triphenylphosphonium chloride 50 mg 1 2,3-Dihydroxybenzene-4-sulfonic acid ammonium 2g 2-Mercaptobenzimidazole-5-sulfonic acid sodium 1.5g

[0090]

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C ₄ H ₉ OCH ₂ CH (OH) CH ₂ N (CH ₂ COOH) ₂
1 g 1-phenyl-5-mercaptotetrazole 15 mg Protective layer solution Next, the following was prepared as a protective layer coating solution. Additives are shown in amounts per liter of coating solution.

Lime-treated inert gelatin 68 g Acid-treated gelatin 2 g Sodium-i-amyl-n-decylsulfosuccinate 1 g Polymethyl methacrylate (matting agent having an area average particle size of 3.5 μm) 1.1 g Silicon dioxide particles (area average particle size 1.2) 0.5 g Ludox AM (manufactured by DuPont) (colloidal silica) 30 g (CH ₂ = CHSO ₂ CH ₂ ) ₂ O (hardener) 500 mg C ₄ F ₉ SO ₃ K 2 mg C ₁₂ H ₂₅ CONH ( CH ₂ CH ₂ O) ₅ H 2.0g

[0093]

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Using the obtained coating solution, the following study was made on the stagnation of the emulsion coating solution on the photographic characteristics. That is, immediately after the preparation of the emulsion coating solution, the stagnation was made 0 hours, and after stagnation for 6 hours and 12 hours, coating was performed to prepare samples. Sensitometry uses two intensifying screens (KO-25
0), and X-rays were irradiated through an aluminum wedge at a tube voltage of 80 kvp and a tube current of 100 mA for 0.05 seconds. Then, using an automatic developing machine (SRX-501), after developing with (XD-SR) developer at 35 ° C,
Fixing was performed with fixer (XF-SR). (All manufactured by Konica Co., Ltd.) The processing time was dry to dry for 45 seconds, and then the sensitivity, gamma and fog were measured. Sensitivity is represented by the reciprocal of the exposure amount that gives a density of fog +0.5, and is a sample No. 1 with no stagnation of 0 hours.
The relative sensitivity when the sensitivity was set to 100 was shown.

Gamma (γ) = 1 / log E ₁ -log E _2, where log E ₁ is the logarithm of the amount of exposure required to achieve a density of 2.0, and log E ₂ is the logarithm of the exposure required to achieve a density of 1.0. Represents the logarithm of the exposure amount. The higher the value, the better the contrast. The obtained results are shown in Tables 1 to 3 below.

[0096]

[Table 1]

[0097]

[Table 2]

[0098]

[Table 3]

As is clear from the table, for example, sample No. 37
Nos. 39 to 39 show remarkable decrease in sensitivity and increase in fog during the stagnation of the coating solution, and further reduced the gamma value and softened, whereas the sample NO containing an iron compound during particle formation according to the present invention was used. It can be seen that, in the case of .40 to 42, there was no rise in fog, and high sensitivity and high gamma were maintained, and stagnation stability was excellent.

Example 2 The sharpness of the sample prepared in Example 1 and the sample prepared in the same manner as in Example 1 were measured. Sharpness is 0.5 ~ 10
MTF chart with line / mm rectangle intensifying screen (KO250)
And the sample film surface was irradiated with X-rays so that the density of the portion not covered by the lead chart was 1.0 on both sides. After the obtained sample was developed in the same manner as in Example 1, the recorded rectangular wave pattern was measured using a Konica Micro Densitometer PDM-5 (Konica Corporation). The aperture size is 300 in the parallel direction of the rectangular wave.
μm, 25 μm in the perpendicular direction, and the magnification was 20 times. In Table 4 below, a value of the spatial frequency of 2.0 lines / mm is shown as a representative of the MTF. As can be seen from the table, the sample of the present invention
The values show that the sharpness is good.

[0101]

[Table 4]

Example 3 (Preparation of hexagonal tabular twin seed emulsion) A hexagonal tabular seed emulsion was prepared by the following method.

A2 Ossein gelatin 24.2 g Distilled water 9657 ml Polypropylene oxy-polyethylene oxy-disuccinate sodium salt (10% ethanol aqueous solution) 6.78 ml KBr 10.8 g 10% nitric acid 114 ml B2 2.5N AgNO ₃ aqueous solution 2825 ml C2 KBr 824 g KI 23.5 g Make up to 2825 ml with distilled water D2 1.75N KBr aqueous solution At the following silver potential control amount at 35 ° C, use a mixing stirrer described in JP-B-58-58288 and 58-58289 to add solution B2 and solution B2 to solution A2. C2
Were added by the double-mixing method over 2 minutes to form nuclei.

After stopping the addition of the solution B2 and the solution C2, it takes 60 minutes to raise the temperature of the solution A2 to 60 ° C., adjust the pH to 5.0 with 3% KOH, and then re-add the solution B2. Solution C2 was added at a flow rate of 55.4 ml / min for 42 minutes by the double jet method. The silver potential (measured with a silver ion selective electrode using a saturated silver-silver chloride electrode as a reference electrode) during the temperature rise from 35 ° C to 60 ° C and re-simultaneous mixing with the solutions B2 and C2 was +8 mv using the solution D2. And +16 mv.

After the addition was completed, the pH was adjusted to 6 with 3% KOH, and the mixture was immediately desalted and washed with water. This kind of emulsion has a maximum adjacent side ratio of 1.0 to 90% or more of the total projected area of silver halide grains.
It was found by an electron microscope that the sample was composed of 2.0 hexagonal tabular grains, and that the average thickness of the hexagonal tabular grains was 0.06 μm and the average diameter (in terms of circular diameter) was 0.59 μm.

(Preparation of Growth Emulsion) EM-7 The obtained hexagonal tabular seed emulsion was prepared by
0.11 mol equivalent, polypropylene oxy at liquid temperature 60 ℃
It was dissolved and dispersed in an aqueous gelatin solution containing polyethylene oxy-disuccinate sodium salt (Step D)
Later, stannous chloride was added at 1 × 10 ^-6 mole per mole of silver in the final silver halide emulsion. Subsequently, the average silver iodide content finally becomes 1.55 mol%.
A silver nitrate solution prepared so as to obtain a halide solution of potassium bromide and potassium iodide was prepared at pH = 5.8 and pAg = 8.
8. While maintaining the whole temperature at 60 ° C., the mixture was added in 107 minutes by the controlled double jet method (Step E),
A tabular silver iodobromide emulsion EM-7 having an average thickness of 1.03 μm, an average thickness of 0.21 μm, and an aspect ratio of 4.83 was obtained.

EM-8 After the step D, stannous chloride was added so as to be 1 × 10 ^-6 mol per mol of silver of the finally formed silver halide emulsion, and a silver nitrate solution, potassium bromide and Potassium iodide and a halide solution were added over 83 minutes by the controlled double jet method while keeping the pH at 5.8 and the pAg at 8.8 (Step E '), and the average particle size was 0.92 μm and the average thickness was 0.20.
A tabular silver iodobromide emulsion having a thickness of 4.3 μm, an aspect ratio of 4.3 and an average silver iodide content of 1.55% was obtained. Using this emulsion as a core, a silver nitrate solution and a potassium bromide solution were successively added at pH = 5.8, pH
Ag = 8.8, added over 24 minutes by the controlled double jet method (Step F), average particle size 1.05 μm, average thickness 0.2
A tabular silver iodobromide emulsion EM-8 having an outermost shell layer of 1 μm and an aspect ratio of 4.88 consisting of pure silver bromide was obtained.

EM-9 Stannous chloride, not after step D, but after step E ', 1 × / mol of silver of the silver halide emulsion finally formed.
A tabular silver iodobromide emulsion EM-9 having an average particle size of 1.05 μm, an average thickness of 0.21 μm, and an aspect ratio of 4.88 was obtained in exactly the same manner as in EM-2 except that it was added to 10 ^-6 mol. .

EM-10 K ₄ [Fe (CN) ₆ ] · 3H ₂ O is added to the halide solution in step E at 2 × / mol of silver of the silver halide emulsion finally formed.
A tabular silver iodobromide emulsion EM-10 having an average particle size of 1.03 μm, an average thickness of 0.21 μm, and an aspect ratio of 4.83 was obtained in exactly the same manner as in EM-7 except that it was added so as to be 10 ^-7 mol. .

EM-11 K ₄ [Fe (CN) ₆ ] .3H ₂ O was added to the halide solution in step E ′ at 2 mol / mol of the silver halide emulsion finally formed.
A tabular silver iodobromide emulsion EM-11 having an average particle size of 1.05 μm, an average thickness of 0.21 μm, and an aspect ratio of 4.88 was obtained in exactly the same manner as in EM-8 except that it was added so as to be × 10 ⁻⁷ mol. Was.

EM-12 K ₄ was added to the halide solution comprising potassium bromide in Step F.
Except that [Fe (CN) ₆ ] .3H ₂ O was added in an amount of 2 × 10 ^-7 mol per mol of silver in the finally formed silver halide emulsion, the same method as EM-9 was used. A tabular silver iodobromide emulsion EM-12 having an average particle size of 1.05 μm, an average thickness of 0.21 μm, and an aspect ratio of 4.88 was obtained.

The EMs 7 to 12 of these emulsions were desalted by a usual method and then redispersed at 40 ° C. under the conditions of PAg 7.8 and pH 5.85. Subsequently, these emulsions were optimally sensitized with gold and sulfur using ammonium thiocyanate, chloroauric acid and sodium thiosulfate.

Prior to gold / sulfur sensitization, Tables 5 and 6
The spectral sensitization was carried out by adding a methanol solution of the spectral sensitizing dye according to the present invention shown in FIG. After sensitization, 4-hydroxy-6-methyl-1,
Stabilization was performed by adding 3,3a, 7-tetrazaindene in an amount of 1.0 g per mol of silver.

An emulsion coating solution and a protective layer coating solution were prepared from the obtained emulsion in the same manner as in Example 1.

The results obtained by examining the stagnation of the emulsion coating solution are shown in Table 5 below.

[0116]

[Table 5]

Example 4 In the same manner as in Example 2, the sharpness of the sample prepared in Example 3 was measured.

Table 6 shows the results. As is clear from the table, it can be seen from the MTF value that the sample of the present invention has good sharpness.

[0119]

[Table 6]

[0120]

According to the present invention, it is possible to improve the stagnation stability of an emulsion coating solution in the production process of a silver halide light-sensitive material and obtain a silver halide photographic light-sensitive material having high sensitivity, high sharpness and high contrast. Was completed.

Claims (1)

(57) [Claims] 1. A silver halide photographic material having at least one tabular silver halide emulsion layer having an aspect ratio of 2.0 or more on a support, wherein the silver halide emulsion is
(1) having a reduced portion in the interior of the particle, further (2) containing at least one iron compound in the interior and / or surface of the particle, and (3) less than 5 mol% of the outermost shell layer of the particle A silver halide grain comprising silver iodide, wherein the silver halide emulsion is spectrally sensitized by at least one of the dyes represented by the following general formulas (I), (II) or (III). A silver halide photographic light-sensitive material, characterized in that: Embedded image [Wherein, R ₁ , R ₂ and R ₃ each represent a substituted or unsubstituted three group; an alkyl group, an alkenyl group or an aryl group, and at least one of R ₁ and R ₃ is a sulfoalkyl Group or carboxyalkyl group. X ₁ ^- is an anion; Z ₁ and Z ₂ are a group of nonmetallic atoms necessary for completing a substituted or unsubstituted benzene ring; and n is 1 or 2. (However, when an internal salt is formed, n is 1.)] [Wherein R ₄ and R ₆ each represent a substituted or unsubstituted following three groups; an alkyl group, an alkenyl group, or an aryl group;
At least one of R ₄ and R ₆ takes a sulfoalkyl group or a carboxyalkyl group. R ₅ represents a hydrogen atom, a lower alkyl group or an aryl group. X ₂ ^- is an anion; Z ₁ and Z ₂ are non-metallic atoms necessary to complete a substituted or unsubstituted benzene ring; and n is 1 or 2. (However, when an inner salt is formed, n is 1.)] Wherein R ₇ and R ₉ are each a substituted or unsubstituted lower alkyl group, R ₈ and R ₁₀ are a lower alkyl group, a hydroxyalkyl group, a sulfoalkyl group, a carboxyalkyl group,
X ₃ ^- represents an anion; Z ₁ and Z ₂ represent a group of nonmetal atoms necessary to complete a substituted or unsubstituted benzene ring; and n represents 1 or 2. (However, when an inner salt is formed, n is 1.)]