JPH08171154A - Method for forming silver halide grains and silver halide emulsion formed by the same - Google Patents

Abstract

PURPOSE: To provide a superior silver halide emulsion low in fog. CONSTITUTION: In this method for forming silver halide grains, an N-containing heterocyclic compound represented by the general formula; Het-(SR)i is used, in which Het is an N-containing hetero ring; R is H atom or an alkyl, alkenyl, alkynyl, or aryl group or a heterocyclic group; i is 0, 1, or 2; and Het or R has directly or indirectly at least one of -SO3 H, -COOH, -OH, and their salts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silver halide emulsion, and more particularly to a silver halide emulsion having high sensitivity, excellent pressure resistance and low fog.

[0002]

2. Description of the Related Art In recent years, the demand for silver halide emulsions for photography has become more and more strict, and higher demands have been made on the sensitivity, pressure resistance and fog relation.

Regarding tabular silver halide grains, US Pat. Nos. 4,434,226, 4,439,520 and 4,414,310 have already been disclosed.
No. 4,433,048, 4,414,306, 4,459,353,
JP-A-59-994335 and JP-A-60-209445 disclose the production method and the use technology thereof, and improve the sensitivity including the improvement of the color sensitizing efficiency by the sensitizing dye, and the improvement of the sensitivity / granularity relationship. The advantages such as are known.

Further, JP-A-63-220238 discloses a technique of introducing a dislocation line into a tabular silver halide grain in order to improve the sensitivity and pressure resistance of the grain.

However, although these techniques had an effect on the sensitivity, graininess and pressure resistance, the fog of the emulsion after physical ripening was adversely deteriorated, and the fog of the light-sensitive material was deteriorated by using the emulsion. Led to.

The emulsion after physical ripening refers to an emulsion which has not been sensitized (chemically ripened) in a state of being washed with water after the completion of grain growth and redispersed in gelatin.

Therefore, while maintaining the advantages of this prior art,
New technology was strongly desired to achieve low fog.

[0008]

With respect to the above problems,
An object of the present invention is to provide a silver halide emulsion excellent in low fog.

[0009]

As a result of earnest research, the inventors of the present invention have found that the above object of the present invention can be achieved by the following, and have completed the present research.

That is, a method for forming silver halide grains characterized by using a nitrogen-containing heterocyclic compound represented by the following general formula [I].

In the general formula [I] Het- (SR) _i , Het represents a nitrogen-containing heterocycle, and R represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group.

I represents an integer of 0, 1 or 2. However,
Het or R has -SO ₃ H, -COOH, in at least one directly or indirectly groups selected from -OH or a salt thereof.

Formed by the method described in the above paragraph, 20% or more of the total projected area is composed of internal high iodine type core / shell type tabular silver halide grains, and the aspect ratio of the tabular silver halide grains is A silver halide emulsion characterized by being 3 or more.

Formed by the method described in the above item, 20% or more of the total projected area consists of internal high iodine type core / shell type silver halide grains, and 50% by number or more of the silver halide grains are 1 grain. A silver halide emulsion characterized by containing five or more dislocation lines per unit.

Formed by the method described in the above item, 20% or more of the total projected area is composed of internal high iodine type core / shell type tabular silver halide grains, and the tabular silver halide grains have an aspect ratio of A silver halide emulsion having a number of 3 or more, and 50% by number or more of the silver halide grains contain 5 or more dislocation lines per grain.

The present invention will be described in detail below.

The compound represented by the following general formula [I] according to the present invention will be explained.

In the general formula [I] Het- (SR) _i , Het represents a nitrogen-containing heterocycle, R represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group,
Represents a heterocyclic group. i represents an integer of 0, 1 or 2. However Het or R has -SO ₃ H, -COOH, in at least one directly or indirectly groups selected from -OH or a salt thereof.

Examples of the nitrogen-containing heterocycle represented by Het of the general formula [I] include an oxazole ring, an imidazole ring,
Thiazole ring, triazole ring, selenazole ring, tetrazole ring, oxadiazole ring, thiadiazole ring,
Thiazine ring, triazine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, indolenine ring, benzoselenazole ring, naphthothiazole ring, triazaindolizine ring, diazaindolizine ring, tetraazaindolizine ring, etc. Represent

Among the compounds represented by the general formula [I], the compounds represented by the following general formulas [II] and [III] are more preferable.

[0021]

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In the formula, R ¹ or R ² is a hydrogen atom, an alkyl group,
It represents an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group, and j represents an integer of 0 or 1. R ¹ or R ² is -SO
_It has directly or indirectly at least one group selected from ₃ H, —COOH, —OH or salts thereof.

[0023]

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In the formula, R ³ represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, and R ⁴ represents a substituent.

Z ¹ is an oxygen atom, a sulfur atom, or --N (R ⁵ )-
The stands, R ⁵ is a hydrogen atom, an alkyl group, an alkenyl group,
Alkynyl group, an aryl group, a heterocyclic group, a ^{-N (R 6) (R 7} ).

R ⁶ or R ⁷ represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. R ^3, with R ⁴ or R ⁵ is -SO ₃ H, -COOH, in at least one directly or indirectly groups selected from -OH or a salt thereof.

In the general formulas [I], [II] and [III], examples of the alkyl group represented by R, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ or R ⁷ include Methyl, ethyl, propyl, i-propyl, butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, dodecyl and the like can be mentioned. These alkyl groups further include halogen atoms (eg chlorine, bromine, fluorine etc.), alkoxy groups (eg methoxy, ethoxy, 1,1-dimethylethoxy, hexyloxy, dodecyloxy etc.), aryloxy groups (eg phenoxy, naphthyl). Oxy etc.), aryl group (eg phenyl, naphthyl etc.), alkoxycarbonyl group (eg methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, 2-ethylhexylcarbonyl etc.) aryloxycarbonyl group (eg phenoxycarbonyl, naphthyloxycarbonyl etc.), alkenyl Groups (eg vinyl, allyl, etc.), heterocyclic groups (eg
2-pyridyl, 3-pyridyl, 4-pyridyl, morpholyl, piperidyl, piperazyl, selenazolyl, sulforanyl,
Piperidinyl, tetrazolyl, thiazolyl, oxazolyl, imidazolyl, thienyl, pyrrolyl, pyrazinyl,
Pyrimidinyl, pyridazinyl, pyrimidyl, pyrazolyl, furyl, etc.), alkynyl group (eg propargyl), amino group (eg amino, N, N-dimethylamino,
Anilino, etc.), a hydroxy group, a cyano group, a sulfo group, a carboxy group, a sulfonamide group (eg, methylsulfonylamino, ethylsulfonylamino, butylsulfonylamino, octylsulfonylamino, phenylsulfonylamino, etc.) and the like.

R, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ or R
Examples of the alkenyl group represented by ⁷ include vinyl and allyl, examples of the alkynyl group include propargyl, examples of the aryl group include phenyl and naphthyl, and a heterocyclic group. As, for example, a pyridyl group (eg, 2-pyridyl, 3-pyridyl, 4-pyridyl, etc.), a thiazolyl group, an oxazolyl group,
Imidazolyl group, furyl group, cenyl group, pyrrolyl group,
Examples thereof include a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a selenazolyl group, a sulforanyl group, a piperidinyl group, a pyrazolyl group and a tetrazolyl group.

The above alkenyl group, alkynyl group, aryl group and heterocyclic group are all R, R ¹ , R ² , R ³ , R ⁴ ,
The alkyl group represented by R ⁵ , R ⁶ or R ⁷ and a group similar to the group shown as the substituent for the alkyl group can be substituted.

The substituent represented by R ⁴ is an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heterocyclic group, a halogen atom, an alkoxy group, an aryloxy group,
Alkoxycarbonyl group, aryloxycarbonyl group, sulfonamide group, sulfamoyl group, ureido group, acyl group, carbamoyl group, amide group, sulfonyl group, amino group, cyano group, nitro group, carboxy group, hydroxy group, hydrogen atom, mercapto Represents a group, an alkylthio group, an arylthio group, an alkenylthio group, a heterocyclic thio group and the like. These groups are R, R ¹ , R ² , R ³ , R ⁴ ,
The alkyl group represented by R ⁵ , R ⁶ or R ⁷ and a group similar to the group shown as the substituent for the alkyl group can be substituted.

The general formulas [I], [II] and [III] are shown below.
Specific examples of the compound represented by are shown below, but the present invention is not limited thereto.

[0032]

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[0033]

[Chemical 4]

[0034]

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[0035]

[Chemical 6]

[0036]

[Chemical 7]

[0037]

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[0038]

[Chemical 9]

[0039]

[Chemical 10]

[0040]

[Chemical 11]

[0041]

[Chemical 12]

[0042]

[Chemical 13]

A considerable effect can be obtained if the water-soluble mercapto compound is contained in any amount, but preferably 10
If it is at least mg / mol silver, and at least 15 mg / mol silver and at most 70 mg, a more remarkable effect can be obtained.

Further, in the case of a nitrogen-containing heterocyclic compound having a mercapto group, some effect can be obtained even if it does not have a water-soluble group (hereinafter referred to as a water-soluble mercapto compound), but it is not sufficient. The water-soluble mercapto is more easily dissolved in the solvent during grain growth, and has a larger effect on the grain during growth. The effect was magnified by using the water-soluble mercapto compound.

Further, when the silver halide photographic emulsion is spectrally sensitized and / or chemically sensitized and the compound added during grain formation remains adsorbed on the surface of the silver halide grain, the performance is affected. It is known that it causes a fluctuation in performance when the residual adsorption amount changes. The compound represented by the general formula [I] has a high efficiency of being removed in the desalting step after the formation of silver halide grains, and spectral sensitization,
The influence on the chemical sensitization process can be reduced and the instability in production can be reduced.

The water-soluble mercapto compound may be added at any stage of emulsion preparation, but it is preferable to add it during grain growth, and it is preferable to add it continuously from the initial stage of growth to the end of growth. More preferable.

The method for quantifying the water-soluble mercapto compound in the silver halide grains in the emulsion of the present invention is generally HPLC.
The (high performance liquid chromatography) method is known. First, as a pretreatment, a certain amount of emulsion is immersed in pure water for about 1 hour and then adjusted to a certain amount to obtain an HPLC sample. As an apparatus, for example, Hitachi L-6000 (pump) / L-6200 (UV-V
is detector) type and the column uses inert silt ODS-
2. Quantify with an organic solvent / water system eluent under the conditions of a flow rate of 1.0 ml / min and a detection wavelength of 254 nm. Absolute calibration curve method, internal standard method and the like are known as quantitative methods.

It is preferable that 50% by number or more of the silver halide emulsions of the present invention contain 5 or more transition lines per grain. The transition line is preferably present at the fringe portion of the tabular grain and at the inner side thereof, and the fringe portion transition line introduction position is preferably introduced at the stage of growth of from 50% to 95% of the silver amount of the entire grain, More preferably 60% or more
It is preferably less than 80%, and more preferably introduced at the boundary where the inner high iodine layer and the outer lower iodine layer are adjacent to each other. Incidentally, the internal high iodine layer referred to in the present invention does not include a high iodine portion formed by the introduction of dislocation lines.

The method of introducing dislocation lines is not particularly limited, but a method of adding a potassium iodide solution and a silver nitrate solution with a double jet at a position where dislocations are to be introduced, a method of adding fine silver iodide particles and an iodine ion-releasing compound are used. The addition method is preferable, and the addition method of silver iodide fine grains is particularly preferable. At that time, the number of dislocation lines can be controlled by the addition amount of the potassium iodide solution or the silver iodide fine particles, but the preferable addition amount varies depending on the total surface area of the grains at the time of introducing the dislocation lines, but the total silver amount of the grains. Is preferably 0.2 mol% or more and 10 mol% or less, more preferably 0.5 mol% or more and 5 mol% or less. If the number of dislocation lines is 5 or more per particle, the effect on sensitivity and pressure property can be obtained, but it is preferably 10 or more per particle.

The dislocations of tabular grains are, for example, J, F. Hamilto.
n, Phot.Sci.Eng., 11,57, (1967) T.Shiozawa, J.Soc.Phot.
It can be observed by a direct method using a transmission electron microscope at low temperature described in Sci Japan, 35, 213, (1972). In other words, the silver halide grains taken out from the emulsion with care not to apply the pressure to generate dislocations on the grains are placed on a mesh for electron microscope observation to prevent damage (printout etc.) due to electron beams. The sample is observed by the transmission method while it is cooled. At this time, the thicker the particles, the more difficult it is for the electron beam to pass therethrough. Therefore, it is possible to more clearly observe using a high-voltage electron microscope (200 kV for a thickness of 0.25 μm). From the photograph of the grain obtained by such a method, the position and number of dislocation lines for each grain when viewed from the direction perpendicular to the principal plane can be obtained.

In the silver halide emulsion of the present invention, tabular grains are preferably used, and 20% of all grains in the emulsion layer are used.
The above is preferably an aspect ratio of 3 or more, and more preferably 5 or more. The aspect ratio as used herein refers to the ratio of the diameter of a circle having the same area as the projected area of tabular grains (projected area diameter) to the distance between parallel planes.
The average diameter / grain thickness ratio of an emulsion is a value obtained by dividing the average aspect ratio of each grain or the total projected area diameter of the corresponding grains by the total distance between parallel planes for grains having an aspect ratio of 2 or more. Represents

As an example of the method of measuring the aspect ratio, there is a method of taking a transmission electron microscope photograph by the replica method and determining the equivalent circle diameter and thickness of each particle. In this case, the thickness is calculated from the length of the shadow of the replica.

The size of the silver halide emulsion of the present invention basically does not matter, but the variation coefficient of the average projected surface diameter is 30.
% Is preferable, and more preferably 20% or less.
Here, the coefficient of variation is a value defined by (standard deviation / average value) × 100 = variation coefficient (%).

The average cubic equivalent diameter of the silver halide emulsion of the present invention (the length of one side of a cube having the same volume as the grain is referred to as cubic equivalent diameter) is preferably 0.05 to 10.0 μm, more preferably 0.1 to 5.0. μm, particularly preferably 0.1 to 3.0
μm.

The average iodine content of the silver halide emulsion of the present invention is preferably 1 mol% or more and 20 mol% or less, more preferably 3 mol% or more and 10 mol% or less.

The intergranular distribution of the silver iodide content of the silver halide emulsion of the present invention is preferably within 30%, more preferably within 20%.

The silver iodide content of the internal high iodide layer of the silver halide grains in the silver halide emulsion of the present invention is preferably 10 mol% or less, more preferably 5 mol% or more and less than 8 mol%.

The silver iodide content of silver halide grains and the average silver iodide content in the emulsion of the present invention can be measured by the EPMA method (Elec
It can be determined by using the tron Probe Micro Analyzer method). This method is a technique in which a sample in which emulsion grains are well dispersed so as not to come into contact with each other is prepared, and an extremely minute portion is subjected to elemental analysis by X-ray analysis by electron beam irradiation with electron beam irradiation. By this method, the halogen composition of each grain can be determined by obtaining the characteristic X-ray intensities of silver and iodine emitted from each grain.

If the silver iodide content of at least 50 grains is determined by the EPMA method, the average silver iodide content can be determined from the average of them. The device used for the measurement does not need to have any special specifications, but in the embodiment of the present invention described later, an X-ray micro analyzer JXA-86 manufactured by JEOL Ltd. is used.
21 was used to measure the silver iodide content of the emulsion. The measurement was performed by cooling to a low temperature in order to remove electron beam damage.

Regarding the halogen composition and structure of the silver halide grains of the present invention, in addition to the EPMA method described above, X-ray diffraction, fluorescent X-ray and XPS methods (X-ray Photoelectoron Spectroscopy) are also used.
It can be confirmed by combining analysis methods.

The silver halide emulsion according to the present invention is prepared by adding silver ion (generally water-soluble silver salt solution) and halogen ion (generally water-soluble halogen salt solution) to a solution containing a protective colloid. The particles can be formed and adjusted, and various techniques known in the art can be used as the forming means in this case. For example, JP-A-61
-6643, 61-146305, 62-157024, 62-18556
Issue 63-92942, Issue 151618, Issue 63-163451, Issue 63-
Known methods such as 220238 and 63-311244 can be referred to.

For example, one of the simultaneous mixing method, the double jet method, and the double mixing method, the so-called control double jet method for keeping the pAg in the liquid phase in which silver halide is produced constant, the soluble silver halide having a different composition are used. A triple double jet method in which they are added independently can also be used. A forward mixing method can be used, or a method of forming grains in the presence of excess silver ions (so-called reverse mixing method) can be used.

A silver halide solvent may be used in the emulsion according to the present invention, if necessary. Examples of the silver halide solvent often used include ammonia, thioethers and thioureas. Regarding thioethers, U.S. Pat.Nos. 3,271,157, 3,790,387 and 3,574,62
You can refer to No. 8 etc.

The mixing method is not particularly limited, and a neutral method without using ammonia, an ammonia method, an acid method or the like can be used.
It is preferably a weak acid method of 5.8 or less, more preferably 2.0.
Not less than 5.0 and not more than 5.0.

The silver halide grain of the present invention contains at least iodine. In this case, the method of adding iodide ion in grain growth is not particularly limited, and it may be added as an ionic solution such as potassium iodide. Further, it may be added as grains having a smaller solubility product than the growing halide grains, for example, silver iodide fine grains. Iodine ion releasing compounds may be used. When added as fine silver iodobromide grains, silver ions and halogen ions are preferably added not as an aqueous solution but as silver halide grains having a desired halogen composition.

In the present invention, iodide ions are preferably added as fine silver halide grains such as fine silver iodide grains or fine silver iodobromide grains from the viewpoint of narrowing the silver iodide content distribution among grains. .

In the present invention, the silver halide emulsion is Research Disclosure No. 308119 (hereinafter referred to as RD308119).
Abbreviated) can be used.

The places described below are shown.

[Item] [Page of RD308119] Iodine composition 993 IA item Manufacturing method 993 IA item and 994E item Crystal wall Normal crystal 993 IA item Twin 993 IA item Epitaxial 993 I- Item A Halogen composition is uniform 993 IB item is not uniform 993 IB item Halogen conversion 994 I-C item Halogen substitution 994 I-C item Metal-containing 994 I-D item Monodisperse 995 IF item Solvent addition 995 IF item Latent image formation position Surface 995 I-G item Internal 995 I-G item Applicable photographic material negative 995 I-H item Positive (including internal fog particles) 995 I-H item Emulsion mixed 995 I- Item J Desalting 995 II-A In the present invention, the silver halide emulsion used is one that has been physically ripened, scientifically ripened and spectrally sensitized. The additives used in such processes are Research Disclosure
No.17643, No.18716 and NO.308119 (Respectively RD
17643, RD18716 and RD308119).

The places described below are shown.

[Item] [Page of RD308119] [RD17643] [RD18716] Chemical sensitizer 996 Item III-A 23 648 Spectral sensitizer 996 IV-A-A, B, C, D, 23-24 648- 649 H, I, J Item Supersensitizer 996 IV-AE, J Item 23-24 648-649 Antifoggant 998 VI 24-25 649 Stabilizer 998 VI 24-25 649 Known compounds usable in the present invention Photographic additives are also described in Research Disclosure above.

The following are relevant points to be described.

[Item] [Page of RD308119] [RD17643] [RD18716] Color turbidity inhibitor 1002 VII-I item 25 650 Dye image stabilizer 1001 VII-J item 25 Whitening agent 998 V 24 UV absorber 1003 VIII- Item I, XIII-C Item 25-26 Light absorber 1003 VIII 25-26 Light scattering agent 1003 VIII Filter dye 1003 VШ 25-26 Binder 1003 IX 26 651 Static inhibitor 1006 XIII 27 650 Hardener 1004 X 26 651 Plastic Agent 1006 XII 27 650 Lubricant 1006 XII 27 650 Activator / Coating aid 1005 XI 26-276
50 Matting agent 1007 XVI Developer (contained in light-sensitive material) 1001 XXB Item Various couplers can be added to the present invention,
Specific examples thereof are described in Research Disclosure above.

The following are relevant descriptions.

[Item] [Page of RD308119] [RD17643] [RD18716] Yellow coupler 1001 VII-D item VIIC-G item Magenta coupler 1001 VII-D item VIIC-G item Cyan coupler 1001 VII-D item VIIC-G item Colored coupler 1002 Item VII-G Item VIIG Item DIR coupler 1001 Item VII-F Item VIIF Item BAR coupler 1002 Item VII-F Other useful residue release 1001 Item VII-F Item Coupler Alkali-soluble coupler Item 1001 Item VII-E Used in the present invention The additive to be added can be added by the dispersion method described in RD308119X IV.

In the present invention, the above-mentioned RD17643 page 28, RD
The supports described in 18716, pages 647-648 and RD308119, XIX, can be used.

The light-sensitive material of the present invention includes the above-mentioned RD308119VII.
An auxiliary layer such as a filter layer or an intermediate layer described in the section -K can be provided.

The light-sensitive material of the present invention is the above-mentioned RD308119VII-
Various layer configurations such as the forward layer, the reverse layer, and the unit configuration described in the section K can be adopted.

As the development processing used in the image forming method of the present invention, known development processing for negative film or reversal film can be utilized.

[0080]

EXAMPLES The present invention will be specifically described with reference to Examples.

[Preparation of Seed Crystal Emulsion] A seed crystal emulsion was prepared as follows.

Using the mixing stirrer shown in JP-B-58-58288 and JP-A-58-58289, the following solution A1 adjusted to 35 ° C. was added with an aqueous solution of silver nitrate (1.161 mol) and potassium bromide and potassium iodide. A mixed aqueous solution (2 mol% potassium iodide) was added over 2 minutes by the simultaneous mixing method while keeping the silver potential (measured with a silver ion selective electrode using a saturated silver-silver chloride electrode as a reference electrode) at 0 mV, Nucleation was performed. Then, it took 60 minutes to raise the liquid temperature to 60 ° C, adjust the pH to 5.0 with an aqueous sodium carbonate solution, and then add an aqueous silver nitrate solution (5.902 mol).
Then, a mixed aqueous solution of potassium bromide and potassium iodide (2 mol% of potassium iodide) was added over 42 minutes by the simultaneous mixing method while maintaining the silver potential at 9 mV. After completion of the addition, desalting and washing with water were immediately performed using an ion exchange membrane and an ultrafiltration membrane while cooling to 40 ° C.

The obtained seed crystal emulsion had an average spherical equivalent diameter of 0.
The emulsion was composed of hexagonal tabular grains having a maximum side ratio of 1.0 to 2.0 and having an average aspect ratio of 24 .mu.m, 4.8, and 90% or more of the total projected area of silver halide grains. This emulsion is called a seed crystal emulsion.

(Solution A1) Oscein gelatin 24.2 g Potassium bromide 10.8 g Polypropyleneoxy-polyethyleneoxy-disuccinate sodium salt (10% aqueous ethanol solution) 6.78 ml 10% nitric acid 114 ml Water 9657 ml [Preparation of silver iodide fine grain emulsion] While vigorously stirring 5.0 liters of a 6.0% by weight gelatin aqueous solution containing 0.06 moles of potassium iodide, 7.06 moles of silver nitrate aqueous solution and 7.06 moles of potassium iodide aqueous solution, 2.0 liters each, were added over 10 minutes. During this period p
H was controlled to 2.0 using nitric acid, and the temperature was controlled to 40 ° C. After the particles were prepared, the pH was adjusted to 5.0 with an aqueous sodium carbonate solution. The average cubic equivalent diameter of the obtained silver iodide fine particles is 0.
It was 05 μm.

[Preparation of Emulsion JN1] 700 ml of a 4.5 wt% inert gelatin aqueous solution containing 0.178 mol of seed crystal emulsion and 0.5 ml of a 10% ethanol solution of polyisoprene-polyethyleneoxy-disuccinate sodium salt. After keeping at 75 ° C. and adjusting pAg to 8.4 and pH to 4.0, particles were formed by the following procedure by the simultaneous mixing method with vigorous stirring.

1) p-Ag of 2.020 mol silver nitrate aqueous solution, 0.188 mol silver iodide fine grain emulsion, and potassium bromide aqueous solution
Was added while keeping pH at 8.4 and pH at 4.0.

2) Then, the solution was cooled to 60 ° C., and pAg was adjusted to 9.8.
Adjusted to. Thereafter, 0.071 mol of silver iodide fine grain emulsion was added and ripened for 2 minutes.

3) Add 1.044 mol of silver nitrate aqueous solution, 0.032 mol of silver iodide fine grain emulsion, and potassium bromide aqueous solution to pAg.
Was added while keeping pH at 9.8 and pH at 4.0. During steps 1) and 3) 430 mg of compound II-23 was dissolved in potassium bromide solution and added.

During the grain formation, each solution was added at an optimum rate so as to prevent the formation of new nuclei and the Ostwald ripening between grains. After completion of the above addition, washing treatment was carried out at 40 ° C. using a usual flocculation method, and then gelatin was added and redispersed to adjust pAg to 8.1 and pH to 5.8.

The obtained emulsion had a cubic equivalent diameter of 0.65 μm,
The emulsion consisted of tabular grains having an average aspect ratio of 5.0. When this emulsion was observed with a transmission electron microscope, it was 80%.
Ten or more dislocation lines were observed in the above (number ratio) grains. The content of compound II-23 in the emulsion was 35.2 mg / mol silver.

[Preparation of Emulsion JN2] Compound II-23 of JN1
Emulsion JN2 was prepared in the same manner as JN1 except that the amount was changed to 200 mg. The obtained emulsion was a tabular grain having a cubic equivalent diameter of 0.65 μm and an average aspect ratio of 4.8. When this emulsion was observed with a transmission electron microscope, 10 or more dislocation lines were observed in 80% or more (number ratio) of grains. The content of compound II-23 in the emulsion was 16.4 mg / mol silver.

[Preparation of Emulsion HN1] Emulsion HN1 was prepared in the same manner as JN1 except that Compound II-23 of JN1 was changed to Comparative Compound A.
It was created. The obtained emulsion has a cubic equivalent diameter of 0.65 μm,
The emulsion consisted of tabular grains having an average aspect ratio of 4.8. When this emulsion was observed with a transmission electron microscope, it was 80%.
Ten or more dislocation lines were observed in the above (number ratio) grains. The content of compound A in the particles was 22.6 mg / mol silver.

[0093]

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[Preparation of Emulsion HN2] From JN1 to Compound II-23
Emulsion HN2 was prepared in the same manner as JN1 except that the above was omitted.
The resulting emulsion was a tabular grain having a cubic equivalent diameter of 0.65 μm and an average aspect ratio of 5.1. When this emulsion was observed with a transmission electron microscope, it was 80% or more (number ratio).
More than 10 dislocation lines were observed in the grain.

[Preparation of emulsion JN3] 700 ml of a 4.5% by weight inert gelatin aqueous solution containing 0.067 mol of a seed crystal emulsion and 0.5 ml of a 10% ethanol solution of polyisoprene-polyethyleneoxy-disuccinate sodium salt was added. After keeping at 75 ° C. and adjusting pAg to 8.4 and pH to 4.0, particles were formed by the following procedure by the simultaneous mixing method with vigorous stirring.

1) 2.086 mol of silver nitrate aqueous solution, 0.194 mol of silver iodide fine grain emulsion, and potassium bromide aqueous solution were pAg
Was added while keeping pH at 8.4 and pH at 4.0.

2) Then, the solution was cooled to 60 ° C. and the pAg was adjusted to 9.8.
Adjusted to. Thereafter, 0.071 mol of silver iodide fine grain emulsion was added and ripened for 2 minutes.

3) pAg of 1.079 mol silver nitrate aqueous solution, 0.033 mol silver iodide fine grain emulsion, and potassium bromide aqueous solution.
Was added while keeping pH at 9.8 and pH at 4.0. During steps 1) and 3) 430 mg of compound II-23 was dissolved in potassium bromide solution and added.

During the formation of particles, each solution was added at an optimum rate so as to prevent the formation of new nuclei and the Ostwald ripening between particles. After completion of the above addition, washing treatment was carried out at 40 ° C. using a usual flocculation method, and then gelatin was added and redispersed to adjust pAg to 8.1 and pH to 5.8.

The obtained emulsion had a cubic equivalent diameter of 0.90 μm,
The emulsion consisted of tabular grains having an average aspect ratio of 6.2. When this emulsion was observed with a transmission electron microscope, it was 80%.
Ten or more dislocation lines were observed in the above (number ratio) grains. The content of compound II-23 in the emulsion was 35.6 mg / mol silver.

[Preparation of Emulsion HN3] From JN3 to Compound II-23
Emulsion HN4 was prepared in the same manner as JN3 except that the above was omitted.
The obtained emulsion was a tabular grain having a cubic equivalent diameter of 0.90 μm and an average aspect ratio of 6.0. When this emulsion was observed with a transmission electron microscope, it was 80% or more (number ratio).
More than 10 dislocation lines were observed in the grain.

[Preparation of Emulsion HN4] Redispersion was completed and pAg,
35.2 mg of compound II-23 was added to HN2 after the adjustment of pH was completed.
/ HN4 was prepared by adding mol silver.

[Preparation of Light-Sensitive Material Sample] Each of the above emulsions JN1,
JN2, JN3, HN1, HN2, HN3, HN4 were prepared by adding general photographic additives such as a hardener to an aqueous solution containing gelatin to prepare a coating solution, which was then coated on an undercoated cellulose triacetate film support. By coating and drying by a conventional method, samples J1, J2, J3, H1, H2, H3, and H4, which are photosensitive materials, were prepared.

Samples J1, J2, J3, H1, H2, H
After performing the following processing and development on 3, H4 in an unexposed state, the density was measured to obtain the fog. The obtained fog value is shown as a value with the fog of Sample J1 being 1. However, the fog means the optical density of the unexposed portion.

Treatment process Treatment time Treatment temperature Image 10 minutes 20 ℃ Stop 2 minutes 20 ℃ Settlement 5 minutes 20 ℃ Wash with water 10 minutes 20 ℃ Dry 1 minute 5 ℃ The composition of the treatment solution used in the above treatment is as follows. Is the street.

(Developer) P-methylaminophenol sulfate 2.5 g L-ascorbic acid 10 g Sodium metaborate (tetrahydrate) 35 g Potassium bromide 1 g Sodium thiosulfate (pentahydrate) 6 g Water was added to 1000 ml (stop solution) ) 3% concentrated acetic acid aqueous solution 1000ml (fixer) ammonium thiosulfate 175.0g anhydrous sodium sulfite 8.5g sodium metasulfite 2.3g water added 1000ml acetic acid pH 6.0 emulsions JN1, JN2, JN3, HN1, HN2, HN3 , HN4 with sodium thiosulfate, chloroauric acid, and sensitizing dye (SSD-
1), (SSD-2) and (SSD-3) were added, and after 1-phenyl-5 after spectral and chemical sensitization so that the fog and sensitivity during 1/100 second exposure were optimized. -Mercaptotetrazole 10 mg / mol silver and 4-hydroxy-6-methyl-1,3,3a, 7
-Tetrazaindene was stabilized by adding 500 mg / mol silver.

Further, the coupler (MCP-1) described below is dissolved in ethyl acetate and tricresyl phosphate, and the resulting dispersion is emulsified and dispersed in an aqueous solution containing gelatin. Prepare a coating solution by adding photographic additives,
Sample JC, which is a color light-sensitive material, is coated and dried on an undercoated cellulose triacetate film support by a conventional method.
1, JC2, JC3, HC1, HC2, HC3, HC4 were prepared.

[0108]

[Chemical 15]

Samples JC1, JC2, JC3, HC1, HC2, HC
After carrying out the following developing treatments for HC3 and HC4 in an unexposed state, the density was measured using green light to obtain the fog.
The obtained fog value is shown as a value with the fog of Sample JC1 being 1.

(Processing step) Processing step Processing time Processing temperature Replenishment amount * Color development 3 minutes 15 seconds 38 ± 0.3 ° C 780ml Bleach 45 seconds 38 ± 2.0 ° C 150ml fixation 1 minute 30 seconds 38 ± 2.0 ° C 830ml stability 60 Second 38 ± 5.0 ℃ 830ml Drying 1 minute 55 ± 5.0 ℃ − * Replenishment amount is the value per 1 m ² of light-sensitive material.

The following color developing solution, bleaching solution, fixing solution, stabilizing solution and its replenishing solution were used.

Color developing solution and color developing replenisher developing solution replenisher Water 800 ml 800 ml Potassium carbonate 30 g 35 g Sodium hydrogen carbonate 2.5 g 3.0 g Potassium sulfite 3.0 g 5.0 g Sodium bromide 1.3 g 0.4 g Potassium iodide 1.2 mg-hydroxylamine Sulfate 2.5g 3.1g Sodium chloride 0.6g-4-Amino-3-methyl-N-ethyl-N- (β-hydroxyethyl) aniline sulfate 4.5g 6.3g Diethylenetriaminepentaacetic acid 3.0g 3.0g Potassium hydroxide 1.2g 2.0 g of water is added to make 1 liter, and the color developer is adjusted to pH 10.06 and the replenisher is adjusted to pH 10.18 using potassium hydroxide or 20% sulfuric acid.

Bleaching solution and bleach replenishing solution Bleaching solution Replenishing solution Water 700 ml 700 ml 1,3-Diaminopropanetetraacetic acid iron (III) ammonium 125 g 175 g Ethylenediaminetetraacetic acid 2 g 2 g Sodium nitrate 40 g 50 g Ammonium bromide 150 g 200 g Glacial acetic acid 40 g 56 g Water Then, the bleaching solution is adjusted to pH 4.4 and the replenisher is adjusted to pH 4.0 using ammonia water or glacial acetic acid.

Fixing Solution and Fixing Replenishing Solution Fixing Solution Replenishing Solution Water 800 ml 800 ml Ammonium thiocyanate 120 g 150 g Ammonium thiosulfate 150 g 180 g Sodium sulfite 15 g 20 g Ethylenediaminetetraacetic acid 2 g 2 g Ammonia water or glacial acetic acid was used as a fixing solution at pH 6.2, After adjusting the replenisher to pH 6.5, add water to make 1 liter.

Stabilizer and stable replenisher water 900 ml p-octylphenol ethylene oxide 10 mol adduct 2.0 g dimethylolurea 0.5 g hexamethylenetetramine 0.2 g 1,2-benzisothiazolin-3-one 0.1 g siloxane (UC-L-77 ) 0.1 g Ammonia water 0.5 ml Water is added to make 1 liter, and the pH is adjusted to 8.5 with ammonia water or 50% sulfuric acid.

The results obtained are shown in the table below.

[0117]

[Table 1]

As can be seen from the table, an emulsion having a low fog was obtained by incorporating the nitrogen-containing heterocyclic compound having a mercapto group of the present invention into a silver halide emulsion.

[0119]

The silver halide emulsion excellent in low fog can be provided.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoji Matsuzaka Konica Stock Company, 1 Sakura-cho, Hino-shi, Tokyo In-house

Claims (4)

[Claims] 1. A method for forming silver halide grains, which comprises using a nitrogen-containing heterocyclic compound represented by the following general formula [I]. In the general formula [I] Het- (SR) _i , Het represents a nitrogen-containing heterocycle, and R represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group or a heterocyclic group. i represents an integer of 0, 1 or 2. However, Het or R has -SO ₃ H, -COOH, in at least one directly or indirectly groups selected from -OH or a salt thereof. 2. A tabular silver halide grain formed by the method according to claim 1, wherein 20% or more of the total projected area is composed of internal high iodine type core / shell type tabular silver halide grains. A silver halide emulsion characterized in that the ratio is 3 or more. 3. The method according to claim 1, wherein 20% or more of the total projected area is composed of internal high iodine type core / shell type silver halide grains, and 50% by number or more of the silver halide grains. A silver halide emulsion characterized by containing 5 or more dislocation lines per grain. 4. A tabular silver halide grain formed by the method of claim 1, wherein 20% or more of the total projected area consists of internal high iodine type core / shell type tabular silver halide grains. The ratio is 3 or more and the silver halide grains
The silver halide emulsion according to claim 1, wherein 50% by number or more contains 5 or more dislocation lines per grain.