JP2893143B2 - 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 which is excellent in rapid processing, has good pressure resistance, and has high sensitivity and high image quality.

[0002]

BACKGROUND OF THE INVENTION For silver halide photographic light-sensitive materials, high sensitivity and high image quality have been eternal issues for engineers involved in the art. There is a demand for a silver halide photographic material having no deterioration in image quality.

Conventionally, there has been known a technique for providing a core / shell structure by providing a layer having a high iodine content inside silver halide grains for increasing the sensitivity. This is because the high iodine layer exists inside the grain, and due to the band structure characteristic, photoholes move to the high iodide layer in the core, and photoelectrons are captured by the chemical sensitization nuclei on the grain surface and recombination is established. And the sensitivity is said to increase.

In addition, tabular silver halide grains having parallel twin planes can adsorb a large amount of spectral sensitizing dyes due to their large specific surface. In particular, in the radiographic system, the indirect transition of silver halide It is known that, since the extinction coefficient of the sensitizing dye is larger than the extinction coefficient of the sensitizing dye, crossover light can be significantly reduced, and as a result, deterioration of image quality can be prevented.

As described above, tabular silver halide grains having a layer having a high iodine content in the core have excellent features for improving sensitivity and image quality. However, when an attempt is made to produce tabular silver halide grains having a high iodine layer in the core, the production ratio of thick non-tabular silver halide grains such as multiple twins increases, and the tabular halide having a high iodine content is increased. The production ratio of silver halide grains was remarkably reduced, and in fact, it was very difficult to produce tabular silver halide grains whose core portion was composed of twin grains having a high iodine content.

Further, when a silver halide photographic light-sensitive material having a layer having a high iodine content therein is rapidly processed by an automatic developing machine, a portion of the developing machine which receives pressure from a transport roller of the developing machine may be desensitized. Have the disadvantage that they tend to cause catastrophic failures such as roller marks, and new technologies for that purpose have been strongly desired.

[0007]

Accordingly, an object of the present invention is to eliminate the occurrence of pressure desensitization and the occurrence of roller marks even when rapid processing is carried out by an automatic processor.
An object of the present invention is to provide a silver halide photographic material capable of obtaining a high-quality image with high sensitivity and little fog.

[0008]

As a result of intensive studies, the present inventors have found that the above-mentioned object is achieved by the present invention described below.

That is, on at least one side of the support,
In a silver halide photographic material having a silver halide emulsion layer, silver halide grains contained in at least one of the silver halide emulsion layers were obtained by growing twin seed grains containing an iron compound. Tabular silver halide grains having an aspect ratio of 2.0 or more, and wherein the tabular silver halide grains contain at least one selected from compounds of Group VIII metals of the periodic table excluding iron. Achieved by photosensitive material.

Hereinafter, the present invention will be described in detail.

The twin seed grains in the present invention mean silver halide crystals having one or more twin planes in one grain, and the classification of twin forms is described in a report by Klein and Moiser. Photographische Korrespondenz, Vol. 99, p. 99,
It is described in detail in Vol. 100, p. 57. Two or more twin planes of a twin may or may not be parallel to each other. or,
The crystal habit may be a {111} plane, a {100} plane, or both, or a spherical shape.

When these silver twin grains are observed with an electron microscope photograph of silver halide grains, the ridge line of the crystal in contact with the {111} face or the {100} face is rounded, And mutually orthogonal to one point near the center of gravity in the particle 3
When a dimension axis is set, particles having a ratio C = L / l between 1.0 and 1.5 of the longest piece length L and the shortest piece length 1 of the vertical, horizontal and height direction axis pieces cut out on the opposing particle plane. Say Particularly preferably, the {111} plane or the {100} plane of the crystal is so rounded that it cannot be distinguished. The tabular silver halide grains obtained by growing the twin grains containing the iron compound of the present invention preferably have two or more parallel twin planes, and more preferably have an even number. Particularly preferably, it has two twin planes. The tabular silver halide grains according to the present invention have a size of
It is preferable that the surface is composed of a 1-plane, a plane composed of a {100} plane, or both.

The iron compound used in the present invention includes 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, ferric glycerophosphate, 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 and the like.

[0014] with a compound of the Group VIII metal, excluding iron contained in the tabular silver halide grains of the present invention, Lee Li <br/> indium, platinum, palladium, nickel, rhodium, osmium, ruthenium , A metal compound derived from cobalt or the like. These metal compounds may be contained not only as metal compounds but also as metal ions and metal atoms in the silver halide grains of the present invention.

The Periodic Table VI excluding iron used in the present invention
Examples of the group II metal compound include iridium (III) chloride, iridium (III) bromide, iridium (IV) chloride, sodium hexachloroiridium (III), hexaammine iridium (III) salt, Hexammineiridium (IV) salt, trioxalatoiridium (III) salt, trioxalatoiridium (IV) salt, platinum chloride (IV), potassium hexachloroplatinate (IV), sodium hexachloroplatinate (IV), hexachloroplatinum (IV) ammonium, tetrachloroplatinic (II), tetrabromoplatinic (II), tetrakis (thiocyanato) platinum (VI) sodium, hexaammineplatinum (I
V) chloride, sodium tetrachloropalladium (II), sodium tetrachloropalladium (IV),
Potassium hexachloropalladium (IV), tetraamminepalladium (II) chloride, potassium tetracyanopalladium (II), nickel chloride, nickel bromide,
Potassium tetrachloronickel (II), hexaamminenickel (II) chloride, sodium tetracyanonickelate (II), potassium hexachlororhodate, sodium hexachlororhodate, sodium hexabromorhodate, ammonium hexachlororhodate, etc. .

In the present invention, the iron compound and the compound of the Group VIII metal of the periodic table excluding iron may be contained in the grains as long as these compounds are present during the formation of silver halide grains. It may be added or dividedly added several times. Further, it is preferable to add a water-soluble silver salt and / or a water-soluble halide solution in advance, and use these aqueous solutions to precipitate silver halide grains.

These compounds are preferably dissolved in water or a suitable solvent and added when forming silver halide grains.
For example, alkali halides (KCI, NaCI, KBr, NaBr, etc.)
May be added to the aqueous solution.

The Group VIII metal compound of the periodic table excluding iron according to the present invention may be added at any stage during the formation of tabular silver halide grains. Good.

As the iron compound contained in the twin seed particles of the present invention, potassium hexacyanoiron (III) and potassium hexacyanoiron (II) are preferable among the above. The amount of the iron compound to be added is as follows.
It may be in the range of 1 × 10 ^-9 to 1 × 10 ^-2 mol per mol, preferably 1 × 10 ^-7 to 1 × 10 ^-4 mol. The iron compound may be contained not only in the iron compound but also in the twin seed particles as iron ions and iron atoms.

Next, the amount of the compound of the Group VIII metal of the Periodic Table excluding iron of the present invention is from 1 × 10 ^-10 to 1 × 10 ^-2 mol per mol of silver halide finally formed. It may be in the range, preferably 1 × 10 ^-8 to 1 × 10 ^-5 mol.

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 1.0 μm or less, particularly preferably 0.5 μm or less, and further preferably 0.3 μm or less.

The advantages of such tabular silver halide grains are:
Improvement of spectral sensitization efficiency, such as improvement of image graininess and sharpness, for example, British Patent 2,112,157, U.S. Patent 4,439,520, 4,433,048, 4,414,310,
Emulsions can be prepared by the methods described in these specifications.

In the present invention, the diameter of a tabular 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 tabular 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 shadows 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,
Measure 100 samples.

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

The tabular silver halide emulsion of the present invention is preferably monodisperse. Here, the monodispersion means that the coefficient of variation of the grain size (standard deviation of grain size / average grain size × 100) is 25.
%, Preferably 20% or less, particularly preferably 15% or less.
% Or less.

The tabular silver halide emulsion of the present invention may have any halogen composition such as silver chloride, silver bromide, silver iodide, silver chlorobromide, and silver iodobromide. 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%.

Further, 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. Production methods of tabular silver halide emulsions are described in JP-A-58-113926, JP-A-58-113927, and JP-A-58-113927.
934, 62-1855, European Patent 219,849, 21
9,850 and so on can be referred to. As a method for producing a monodisperse tabular silver halide emulsion, JP-A-61-6
No. 643 can be referred to.

As a method for producing a tabular silver iodobromide emulsion having a high aspect ratio, a silver nitrate aqueous solution is added to a gelatin aqueous solution having a pBr of 2 or less, or a silver nitrate aqueous solution and a halide aqueous solution are simultaneously added. By generating twin seed particles and then growing them by a 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. Also, during 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 of the present invention is preferably used in combination with chalcogen sensitization and gold sensitization as a sensitization method.
In particular, the combined use of gold sensitization and sulfur sensitization is preferable because not only the sensitizing effect is remarkable but also the fog suppressing effect can be obtained.

For sulfur sensitization, sensitizers include, for example, thiosulfate, allylthiocarbamide thiourea, allylisothiocyanate, cystine, p-toluenethiosulfonate, rhodanine and the like. Other U.S. Patent 1,574,944
No. 3,656,955, German Patent 1,422,869, Japanese Patent Publication No. 56
Sensitizers described in JP-A-24937 and JP-A-55-45016 can also be used. The sulfur sensitizer may be added in an amount sufficient to effectively increase the sensitivity of the emulsion. This amount can be varied over a wide range under various conditions such as pH, temperature, and the size of silver halide grains, but as a guide, it is preferably from 10 ^-7 to 10 ^-1 mol per mol of silver halide.

For gold sensitization, gold sensitizers such as chloroaurate, potassium chloroaurate, auric trichloride, potassium auric thiocyanate, potassium iodooleate, tetracyano auric amide, ammonium aurothiocyanate, pyridyl trichlorogold And the like. The addition amount of these gold sensitizers can be varied over a wide range under various conditions, but as a guide, it is preferably 5 × 10 ^{−7 to} 5 × 10 ⁻³ mol per mol of silver halide, and preferably 2 × 10 ⁻⁶ to 4 × 10 ^-4 mol is more preferred.

In the present invention, reduction sensitization and hydrogen sensitization can be used. Stannous salts as reduction sensitizers,
Amines, formamine disulfinic acid, silane compounds, borane compounds, ascorbic acid and derivatives thereof can be used.

The amount of the reduction sensitizer to be added varies depending on the reducibility of the compound, the type of silver halide, the emulsion production conditions such as the dissolution conditions, etc., but is from 1 × 10 ^-8 to 1 × per mol of silver halide.
A range of 10 ^-2 mol is suitable.

The chemical ripening temperature of the emulsion according to the present invention is arbitrarily determined, but is preferably in the range of 20 ° C. to 90 ° C., preferably 30 ° C. to 80 ° C., and more preferably 35 ° C. to 70 ° C.

The emulsion may be subjected to a water washing method such as a noodle 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 (Dec. 1989)
Month). The following table shows the types and locations of the compounds shown in these three research disclosures.

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, and 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.

[0045]

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 seed emulsion for comparison) The following solution was prepared.

A ₁ solution water 11.5 l potassium bromide 2.05 g ossein gelatin 100 g B ₁ solution water 2.6 l potassium bromide 65 g potassium iodide 1.8 g ossein seratin 55 g 0.2 N sulfuric acid 38.5 cc C ₁ solution water 3.0 l bromide and kept at 60 ° C. put a ₁ solution of potassium 950g potassium iodide 27g ossein gelatin 75 g D ₁ liquid water 2.7l silver nitrate 95 g E ₁ solution water 3.2l silver nitrate 1410g kettle, other liquid was added at 59 ° C. . In this case, the controlled double jet method ₁ solution and D ₁ solution B, was added over 30 minutes, then, C
With _one solution and E ₁ solution controlled double jet method 10
Added over 5 minutes. The stirring was performed at 500 rpm. The flow rate is increased in proportion to the total surface area of the silver halide grains as the grains grow, and when the additive liquid flows in, no new growth nuclei are generated, and so-called Ostwald ripening occurs, and the particle size distribution is increased. At a flow rate that does not spread. At the time of adding the silver ion solution and the halide ion solution, pAg was adjusted to 8.3 ± 0.05 using a potassium bromide solution, and pH was adjusted to 2.0 ± 0.1 using sulfuric acid. The resulting emulsion has a particle size of 0.
Cubic tetradecahedral monodisperse grains having 30 μm, 5% of {111} planes, and a few corners of {100} planes, each having a slightly lacking angle and having a silver iodide content of 2 mol%. This emulsion is designated as Em-1.

(Preparation of Comparative Seed Emulsion Em-2) C _{1 of} Em- ₁
Comparative seed emulsion Em- was prepared in exactly the same manner as Em-1, except that 7 g of potassium hexacyanoferrate (II) trihydrate was added to the solution.
2 was prepared.

(Preparation of Comparative Seed Emulsion Em-3) C _{1 of} Em- ₁
Comparative seed emulsion Em- was prepared in exactly the same manner as Em-1, except that 0.7 g of potassium hexacyanoferrate (II) trihydrate was added to the solution.
3 was prepared.

(Preparation of Comparative Emulsion Em-4) C _{1 of} Em- ₁
Comparative seed emulsion Em was prepared in exactly the same manner as Em-1, except that 0.12 g of potassium hexacyanoferrate (II) trihydrate was added to the solution.
-4 was prepared.

(Preparation of Comparative Emulsion) First, the following solutions were prepared. All amounts are given per mole of silver halide.

J ₁ solution (reaction mother liquor) Gelatin 10 g concentrated ammonia water 28 ml glacial acetic acid 3 ml water 600 ml K ₁ solution potassium bromide 5 g potassium iodide 3 g gelatin 0.8 g water 110 ml L ₁ solution potassium bromide 90 g gelatin 2.0 g water 240 ml M ₁ solution (0.75N) AgNO ₃ 9.9 g NH ₄ OH 7.0 ml water 110 ml N ₁ solution AgNO ₃ 130 g NH ₄ OH 100 ml water 240 ml O ₁ solution Potassium bromide 94 g water 165 ml P ₁ solution AgN O ₃ was stirred at 800rpm with 9.9 g NH ₄ OH 7.0 ml water 110 ml J ₁ was kept at 40 ° C. with a stirrer.
PH of J ₁ solution was adjusted to 9.90 with acetic acid, the comparison seed emulsion Em-1 was dispersed and suspended in 1 mol of silver halide per 0.119 mole equivalent collected thereto. Then brought to 7.3 and the pAg was added at a constant rate over a P ₁ solution for 7 minutes. Further, the K ₁ solution and the M ₁ solution were simultaneously added over 20 minutes. The pAg at this time was kept constant at 7.30 (step 1). Further, after adjusting the pH to 8.83 and the pAg to 9.0 using a potassium bromide solution and acetic acid over 10 minutes,
The L ₁ solution and the N ₁ solution were simultaneously added over 30 minutes. At this time,
The inflow rate ratio at the start of addition and at the end of addition is 1:10,
The flow rate was increased over time. Also, the pH was lowered from 8.83 to 8.00 in proportion to the inflow. When the L ₁ solution and the N ₁ solution were added in only 2/3 of the total amount, the O ₁ solution was additionally injected and added at a constant speed over 8 minutes. At this time, pAg is 9.0
From 11.0 to 11.0. Further, acetic acid was added to adjust the pH to 6.0. Next, the excess salt was removed by the same desalting method as in the seed emulsion to obtain a comparative emulsion EM-1.

[0053] As a (comparative emulsion EM-2 of Preparation) EM-1 per mol of silver halide 1 × 10 ^-8 mol of potassium hexachloroiridate (VI) acid is finally formed on the L ₁ solution Comparative emulsion EM-2 was obtained in exactly the same manner as in EM-1, except that grains were formed by addition.

[0054] As a (comparative emulsion EM-3 of Preparation) EM-1 per mol of silver halide 1 × 10 ^-5 mol of potassium hexachloroiridate (VI) acid is finally formed on the L ₁ solution A comparative emulsion EM-3 was obtained in exactly the same manner as in EM-1 except that grain formation was performed by addition.

(Preparation of Comparative Emulsion EM-4)
Grain formation was carried out in exactly the same manner as for EM-2 except that Em-2 was used instead of -1 to obtain comparative emulsion EM-4.

(Preparation of Comparative Emulsion EM-5)
Grain formation was carried out in exactly the same manner as for EM-3 except that Em-2 was used instead of -1 to obtain Comparative Emulsion EM-5.

(Preparation of Comparative Emulsion EM-6)
Except for using -3, grains were formed in the same manner as in EM-2 to obtain comparative emulsion EM-6.

(Preparation of Comparative Emulsion EM-7)
Particle formation was carried out in exactly the same manner as in EM-3 except that EM-3 was used, whereby a comparative emulsion EM-7 was obtained.

(Preparation of Comparative Emulsion EM-8)
Particle formation was carried out in exactly the same manner as in EM-2, except that -4 was used, to obtain a comparative emulsion EM-8.

(Preparation of Comparative Emulsion EM-9)
Except for using -4, grains were formed in the same manner as in EM-3 to obtain comparative emulsion EM-9.

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

A ₂ ossein gelatin 150 g potassium bromide 53.1 g potassium iodide 24 g water 7.2 l B ■ silver nitrate 1500 g water 6 l C ■ potassium bromide 1327 g water 3 l D ■ ammonia water (28%) 705 ml at 40 ° C. The solution B _{2 and the} solution C ₂ were added to the vigorously stirred solution A _{2 in} 30 seconds by a double jet method to generate nuclei.
The pBr at this time was 1.09 to 1.15.

[0063] 1 min 30 seconds after D ₂ solution was added for 5 minutes and aged at 20 seconds. 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 immediately desalting and washing were 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 variation coefficient of the particle size of 18%. This twin seed emulsion was designated as Em-5.

(Preparation of Twin Seed Emulsion Em-6) C _{2 of} Em-5
The twin seed emulsion Em- was prepared in exactly the same manner as Em-5 except that 3 g of potassium hexacyanoferrate (II) trihydrate was added to the solution.
6 was prepared.

(Preparation of Twin Seed Emulsion Em-7) C _{2 of} Em-5
The twin seed emulsion Em- was prepared in exactly the same manner as Em-5, except that 0.3 g of potassium hexacyanoferrate (II) trihydrate was added to the solution.
7 was prepared.

(Preparation of twin seed emulsion Em-8) C _{2 of} Em-5
Twin seed emulsion Em was prepared in exactly the same manner as Em-5, except that 0.05 g of potassium hexacyanoferrate (II) trihydrate was added to the solution.
-8 was prepared.

[Preparation of Tabular Emulsion] The twin seed emulsion Em-
A tabular silver halide emulsion composed mainly of tabular twin grains was prepared using the following three solutions.

E ₂ ossein gelatin 37 g Propyleneoxy / polyethyleneoxy disuccinate disodium salt (10% methanol solution) 10 ml Twin seed emulsion Em-1 equivalent to 0.191 mol Equivalent to water 4000 ml F ₂ ossein gelatin 109 g Potassium bromide 804 g 23.1 g of potassium iodide 4628 ml of water 1128 g of G ₂ silver nitrate 6428 ml of water To the E ₂ solution stirred vigorously at 65 ° C., the F ₂ solution and the G ₂ solution were added by a double jet method over 112 minutes. During this time the pH was 5.8, pAg
Kept at 9.0 throughout. The addition rates of the F ₂ solution and the G ₂ solution were linearly increased so that the initial and final addition rates were 6.4 times.

After completion of the addition, the pH was adjusted to 6.0, and then desalting was carried out according to the method described in JP-B No. 35-16086 to remove excess salts. Emulsion EM-10 was obtained.

Observation of the obtained emulsion with an electron microscope revealed tabular silver halide grains having an average grain size of 1.75 μm and a variation coefficient of the grain size of 19%. The average aspect ratio of the particles was 5.2.

(Preparation of Tabular Emulsion EM-11) F _{2 of} EM-10
16 minutes and 32 seconds before the completion of the addition of the solution, potassium hexachloroiridate (IV) is finally formed.
Was added with stirring F ₂ solution so that 1 × 10 ^-8 mol per mol, except performing the grain formation to prepare a tabular silver halide emulsion EM-11 in exactly the same manner as EM-10 .

(Preparation of Tabular Emulsion EM-12) F _{2 of} EM-10
16 minutes and 32 seconds before the completion of the addition of the solution, potassium hexachloroiridate (IV) is finally formed.
Was added with stirring F ₂ solution so that 1 × 10 ^-5 mol per mol, except performing the grain formation to prepare a tabular silver halide emulsion EM-12 in exactly the same manner as EM-10 .

(Preparation of Tabular Emulsion EM-13) Grain formation was carried out in exactly the same manner as in EM-11, except that Em-6 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-13 was obtained.

(Preparation of Tabular Emulsion EM-14) Grain formation was carried out in exactly the same manner as in EM-12 except that Em-6 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-14 was obtained.

(Preparation of Tabular Emulsion EM-15) Grain formation was carried out in exactly the same manner as in EM-11 except that Em-7 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-15 was obtained.

(Preparation of Tabular Emulsion EM-16) Grain formation was carried out in exactly the same manner as in EM-12 except that Em-7 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-16 was obtained.

(Preparation of Tabular Emulsion EM-17) Grain formation was carried out in exactly the same manner as in EM-11 except that Em-8 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-17 was obtained.

(Preparation of Tabular Emulsion EM-18) Grain formation was carried out in exactly the same manner as in EM-12 except that Em-8 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-18 was obtained.

Next, these emulsions EM-1 to EM-18 were obtained.
Was optimally chemically sensitized using ammonium thiocyanate, chloroauric acid and sodium thiosulfate. After chemical sensitization, add a stabilizer to each emulsion
After adding an appropriate amount of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene and further adding potassium iodide, the following spectral sensitizing dyes (A) and (B) were added to silver halide 1 respectively. 300 mg and 5 mg were added per mole.

Spectral sensitizing dye (A) Anhydride of sodium 5,5'-dichloro-9-ethyl-3,3'-di- (3-sulfopropyl) oxacarbocyanine Spectral sensitizing dye (B) 5 , 5'-di- (butoxycarbonyl) -1,1'-diethyl-3,
Anhydrous 3'-di- (4-sulfobutyl) benzenezoimidazolocarbocyanine sodium salt The resulting emulsion was added with the following additives 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 applied per side was 2.
Using a two slide hopper type coater, apply simultaneously on both sides of the support at a speed of 80 m / min so that the amount of gelatin becomes 3.1 g / m ² with 0 g / m ² , and dry in 2 min 20 sec. A sample was obtained. Glycidi methacrylate 50wt as support
%, Methyl acrylate 10wt%, butyl methacrylate
The concentration of the copolymer consisting of 40 wt% of three monomers is 10 wt%
A polyethylene terephthalate film base colored blue to a concentration of 0.15 for an X-ray film of 175 μm using an aqueous dispersion of the copolymer obtained by diluting so as to give an undercoating liquid 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 , 3-Dihydroxybenzene-4-ammonium sulfonate 4g 2-Mercaptobenzimidazole-5-sodium sulfonate 1.5g

[0084]

Embedded image

C ₄ H ₉ OCH ₂ CH (OH) CH ₂ N (CH ₂ COOH) ₂ 1 g 1-phenyl-5-mercaptotetrazole 15 mg diethylene glycol 7 g dextran (average molecular weight 60,000) 600 mg sodium polyacrylate (average molecular weight 3.6 2.5 g Next, the following was prepared as a coating solution for the protective layer. The additives are shown in an amount per liter of the coating solution.

Lime-treated inert gelatin 68 g Acid-treated gelatin 2 g Sodium-i-amyl-n-decylsulfosuccinate 0.3 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 μm matting agent) 0.5 g Ludox AM (manufactured by DuPont) (colloidal silica) 30 g (CH ₂ = CHSO ₂ CH ₂ ) ₂ O (hardening agent) 7 mg

[0087]

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The obtained coated samples were evaluated for sensitometry, pressure resistance and roller mark.

(1) Sensitometry (Evaluation of photographic performance) In sensitometry, a sample was sandwiched between two intensifying screens (KO-250), a tube voltage of 80 kvp, and a tube current of 100 m via an aluminum wedge.
A, X-rays were irradiated for 0.05 seconds. Next, an automatic processor (SRX
-501), developed with (XD-SR) developer at 35 ° C., and fixed with fixer (XF-SR). The processing time was dry to dry for 45 seconds to determine the sensitivity. The sensitivity is expressed by the reciprocal of the exposure amount that gives a density of fog +0.5,
The relative sensitivity is shown with the sensitivity of o.1 as 100. (2) Evaluation of pressure resistance As a method of evaluating pressure resistance, each sample was kept at a constant temperature and humidity of 25 ° C. and a relative humidity of 50% for about 12 hours, and under this condition, it was bent at a radius of curvature of 2 cm and about 280 °. Was. Three minutes after the bending, exposure was performed using an optical wedge, and development was performed. The wedge blackening density of this sample was measured, and the density difference between the desensitized portion caused by bending and the portion not bent was defined as ΔD, ΔD was divided by each density D, and the average value ΔD was obtained.
/ D was calculated, and this value was used as a measure of pressure desensitization. That is, the smaller the value, the better the pressure desensitization resistance.

The obtained sample was similarly treated with SRX-501 and XD-SR.

(3) Evaluation of Roller Mark Property The pressure mark = roller mark by the roller of the automatic developing machine was evaluated as follows. That is, the film was processed in an undeveloped state by an automatic developing machine having a facing roller. Table 1 shows the obtained results. The roller marks generated at that time were visually evaluated and classified into the following five grades.

5: No roller mark occurred 4: Very slight occurrence 3: Slight occurrence (within practical use permission) 2: Many occurrences (out of practical use permission) 1: Very high occurrence Shown in

[0093]

[Table 1]

As is evident from the results in Table 1, the tabular silver halide emulsions EM-13 to EB-13 in which the twin seed grains contain an iron compound and further contain a compound of iridium which is a Group VIII metal of the periodic table. It can be seen that Sample Nos. 13 to 18 of EM-18 not only have good photographic performance, but also have no pressure desensitization when super-rapid processing is performed, and furthermore, the roller mark failure is suppressed.
This effect was not expected from the prior art.

[0095] Example 2 (tabular emulsion EM-19 Preparation of) EM-10 per mol of silver halide 1 × 10 ^-7 mol of potassium hexachloroiridate (IV) to be finally formed on F ₂ solution become so in advance was added, tabular silver halide in exactly the same manner as EM-10, except performing grain formation by regulating liquid F ₂ solution EM-
19 was prepared.

(Preparation of tabular emulsion EM-20) F _{2 of} EM-10
Was added in advance F ₂ solution so that 1 mol of silver halide per 1 × 10 ^-5 mol of potassium hexachloroiridate (IV) to be finally formed in the liquid, except for performing grain formation by solution preparation A tabular silver halide EM-20 was prepared in exactly the same manner as EM-10.

(Preparation of tabular emulsion EM-21) Grain formation was carried out in exactly the same manner as in EM-19 except that Em-6 was used instead of Em-5 as a twin seed emulsion, and tabular silver halide was formed. emulsion
EM-21 was obtained.

(Preparation of Tabular Emulsion EM-22) Grain formation was carried out in exactly the same manner as in EM-20 except that Em-6 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-22 was obtained.

(Preparation of Tabular Emulsion EM-23) Grain formation was carried out in exactly the same manner as in EM-19 except that Em-7 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-23 was obtained.

(Preparation of Tabular Emulsion EM-24) Grain formation was carried out in exactly the same manner as in EM-20 except that Em-7 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-24 was obtained.

(Preparation of Tabular Emulsion EM-25) Grain formation was carried out in exactly the same manner as in EM-19 except that Em-8 was used instead of Em-5 as a twin seed emulsion, and tabular silver halide was formed. emulsion
EM-25 was obtained.

(Preparation of Tabular Emulsion EM-26) Grain formation was carried out in exactly the same manner as in EM-20 except that Em-8 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-26 was obtained.

The obtained tabular silver halide emulsion EM
-19 to EM-26 in the same manner as in Example 1.
o.19 to 26 were prepared and evaluated in the same manner as in Example 1. The results obtained are shown in Table 2 below.

[0104]

[Table 2]

As is evident from Table 2, even if a compound of iridium, which is a Group VIII metal of the periodic table, is contained in the entire portion of the tabular silver halide grains formed from the twinned grains, It can be seen that the same effect as in Example 1 cannot be obtained unless the crystal seed emulsion contains an iron compound.

[0106] Example 3 (tabular emulsion preparation of EM-27) halogenation EM-10 to 16 minutes 32 seconds before the completion of the addition of F ₂ solution of hexachlororhodate sodium dihydrate finally formed 1 per mole of silver
Add the F ₂ solution with stirring so as to be × 10 ^-6 mol,
A tabular twin EM-27 was prepared in exactly the same manner as EM-10 except that the particles were formed.

(Preparation of Tabular Emulsion EM-28) Sodium hexachlororhodate dihydrate in F ₂ solution of EM-10 is 1 × 10 ^-6 mol per mol of silver halide finally formed. Add F ₂ solution in advance as
A tabular silver halide emulsion EM-28 was prepared in exactly the same manner as in EM-1 except that the solution was prepared and grains were formed.

(Preparation of Tabular Emulsion EM-29) Grain formation was carried out in exactly the same manner as in EM-27, except that Em-6 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-29 was obtained.

(Preparation of Tabular Emulsion EM-30) Grain formation was carried out in exactly the same manner as in EM-28 except that Em-6 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-30 was obtained.

(Preparation of tabular emulsion EM-31) Grain formation was carried out in exactly the same manner as in EM-27 except that Em-7 was used instead of Em-5 as a twin seed emulsion, and tabular silver halide was formed. emulsion
EM-31 was obtained.

(Preparation of tabular emulsion EM-32) Grain formation was carried out in exactly the same manner as in EM-28 except that Em-7 was used instead of Em-5 as a twin seed emulsion, and tabular silver halide was formed. emulsion
EM-32 was obtained.

(Preparation of Tabular Emulsion EM-33) Grain formation was carried out in exactly the same manner as in EM-27 except that Em-8 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-33 was obtained.

(Preparation of Tabular Emulsion EM-34) Grain formation was carried out in exactly the same manner as for EM-28 except that Em-8 was used instead of Em-5 as a twin seed emulsion. emulsion
EM-34 was obtained.

The obtained tabular silver halide emulsion EM-27-
Using EM-34, Sample Nos. 27 to 3
4 was prepared and evaluated in the same manner as in Example 1. The results obtained are shown in Table 3 below.

[0115]

[Table 3]

As is clear from Table 3, the periodic table VIII
No. 2 of the sample of the present invention containing a compound of rhodium which is a group metal and further containing an iron compound in the twin seed emulsion.
9 to 34 have the same effect as in the first embodiment.

[0117]

As described above, according to the present invention, high sensitivity and high sensitivity can be obtained with good photographic performance by rapid processing, and with little desensitization due to film bending or the like, and almost no occurrence of roller marks due to the pressure of the conveying roller of the automatic developing machine. A silver halide photographic light-sensitive material having high image quality could be provided.

Claims (1)

(57) [Claims] 1. A silver halide photographic material having a silver halide emulsion layer on at least one side of a support, wherein the silver halide grains contained in at least one of the silver halide emulsion layers are made of iron. An aspect ratio obtained by growing twin seed grains containing a compound is a tabular silver halide grain having a ratio of 2.0 or more, and the tabular silver halide grain is a Group VIII metal of the periodic table excluding iron. A silver halide photographic material comprising at least one compound selected from the group consisting of: