JPH1031277A - Silver halide photographic emulsion, and silver halide photographic sensitive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a platelike silver halide emulsion and silver halide photographic sensitive material which are excellent in fogging and sensitivity and are improved in reciprocity law failure. SOLUTION: This silver halide emulsion contains silver halide particles which are tabular silver halide particles having hexagonal [111] surfaces at >=10% of a total projection area on a main plane and have the grooves parallel respectively with the six sides of this main plane on the main plane. The silver halide photographic sensitive material contains the silver halide emulsions in at least one layer of the silver halide emulsion layers formed on a substrate.

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 (hereinafter, also simply referred to as "emulsion") and a silver halide photographic material (hereinafter, also simply referred to as "photosensitive material"). More specifically, the present invention relates to a silver halide emulsion and a silver halide photographic light-sensitive material which are excellent in sensitivity and fogging relation and have high illuminance failure.

[0002]

2. Description of the Related Art The demand for improving the performance of silver halide photographic light-sensitive materials has become increasingly severe, and the development of photographic emulsions having high sensitivity and low fog has been further desired.
On the other hand, there is also a strong market demand for improving the performance stability of silver halide photographic materials. The performance stability of a silver halide photographic light-sensitive material can be roughly classified before, during, and after photographing. The stability before photographing is due to the stability of the recording material itself, the stability during photographing is due to the uniformity of the recording process, and the stability after photographing is due to the robustness of the recorded information.

In recent years, with the spread of compact cameras and films with lenses, photography using a strobe has become commonplace. However, with conventional photosensitive materials, there was a substantial difference in photographic sensitivity between photography using a strobe and photography under sunlight (high illuminance failure). Characteristics are being strongly demanded.

[0004] Silver halide grains are a dominant factor in the basic performance of silver halide photographic light-sensitive materials, and the development of silver halide grains aimed at improving sensitivity and image quality has been energetically addressed. In general, in order to improve the image quality, it is effective to reduce the particle size of the silver halide particles, increase the number of particles per unit silver amount, and increase the number of coloring points (the number of pixels). However, reducing the particle size causes a serious decrease in sensitivity, and there is a limit to satisfying both high sensitivity and high image quality. Techniques for improving the sensitivity / size ratio per silver halide grain have been studied in order to achieve higher sensitivity and higher image quality. One of the techniques is to use tabular silver halide. JP-A-58-
No. 111935, No. 58-111936, No. 58-1
Nos. 11937, 58-113927, 59-99
No. 433, etc.

When these tabular silver halide grains are compared with so-called normal crystal silver halide grains such as hexahedral, octahedral, or dodecahedral grains, the surface area per unit volume of the silver halide grains is increased. In the case of the same volume, tabular grains have the advantage that more spectral sensitizing dyes can be adsorbed on the grain surface and that higher sensitivity can be achieved. JP-A-63-92942 discloses a technique for providing a region having a high silver iodide content in tabular silver halide grains, and JP-A-63-151618 discloses a hexagonal tabular silver halide. Techniques using particles have been taken and the effects on sensitivity and granularity have been shown, respectively.

[0006] Japanese Patent Application Laid-Open No. 63-106746 discloses that
Japanese Patent Application Laid-Open No. 1-279237 discloses that a tabular silver halide grain having a substantially layered structure in a direction parallel to two opposing main planes is substantially parallel to two opposing main planes. Tabular silver halide grains having a layered structure delimited by planes parallel to each other, wherein the average silver iodide content of the outermost layer is at least 1 mol% or more higher than the average silver iodide content of the whole silver halide grains Are described for each of the techniques used. In addition, in JP-A-1-183644,
A technique using tabular silver halide grains in which the silver iodide distribution of a silver halide phase containing silver iodide is completely uniform is described.

[0007] There are also several reports on techniques focusing on parallel twin planes in tabular silver halide grains. For example, in JP-A-63-163451, the ratio (b / a) of the longest distance (a) between two or more twin planes and the thickness (b) of a grain is 5 or more. A technique using tabular silver halide grains is further disclosed in
No. 1649 discloses a technique in which the number of dislocation lines present in tabular silver halide grains is also defined at the same time, and reports effects on sensitivity, graininess, and sharpness.

In WO 91/18320, a technique using tabular silver halide grains having a distance between at least two twin planes of less than 0.012 μm is disclosed in JP-A-3-35543. A technique using core / shell twin silver halide grains having an average interplanar distance of 10 to 100 ° has been reported, and the effects of improving sensitivity, granularity, sharpness, pressure characteristics, and granularity have been described, respectively. I have.

In order to improve various photographic performances,
Silver halide grains having an epitaxial junction phase have also been developed. For example, Japanese Patent Publication No. 3-45809 discloses that a silver different from the host grains which is arranged by epitaxial growth mainly on the edge of the host silver halide grains having an average aspect ratio of less than 8 surrounded by {111} crystal planes. A technique for increasing photographic sensitivity by using a silver halide emulsion having a salt has been disclosed. JP 6
JP-A-2-124552 discloses a silver halide emulsion in which the surface of silver halide grains is ruffled. Also,
A report by Mascasky "Journal of Im
aging Science, 32, 160 (198
8) ", silver halide grains having various epitaxial junction phases are introduced.

However, a halogen containing tabular silver halide grains having a hexagonal main plane, wherein the main plane has grooves parallel to six sides of the main plane. Silver halide emulsions were not previously known.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a tabular silver halide emulsion and a silver halide photographic light-sensitive material which are excellent in sensitivity and fog and have high illuminance failure.

[0012]

The above object of the present invention is attained by the following constitutions.

1. 10% or more of the entire projected area is a tabular silver halide grain having a hexagonal {111} plane on a main plane, and grooves on the main plane each parallel to six sides of the main plane. A silver halide emulsion containing tabular silver halide grains.

2. A silver halide photographic light-sensitive material comprising the silver halide emulsion described in 1 above in at least one photosensitive silver halide emulsion layer provided on a support.

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

Incidentally, tabular silver halide grains contained in the silver halide emulsion of the present invention may be simply referred to as silver halide grains of the present invention.

Tabular silver halide grains are crystallographically classified as twins. A twin is a crystal having one or more twin planes in one grain. The classification of twin morphology in silver halide grains is described in a report by Klein and Moiser, "Photographhishhe Korrespon."
denz, Vol. 99, p. 99, and Vol. 100, p. 57. The tabular silver halide grains in the present invention are defined as one or two or more ｛1 grains parallel to each other in the grains.
Although it has a twin plane parallel to the 11 ° plane, it is preferably a particle having two parallel twin planes.

The silver halide grains of the present invention have a surface consisting mainly of {111} planes parallel to the twin plane. The surface has the largest area among the planes forming the surface of the tabular grains, and in the present invention, the surface is referred to as a main plane. In the present invention, having a hexagonal main plane means
This refers to a case where the main plane has a hexagonal shape.

The expression "having a hexagonal shape" means that the main plane is composed of six sides. The length a of the longest side and the length of the shortest side among the six sides are described. The ratio of b is 4 or less (a / b ≦ 4). In the present invention, the value is preferably 1 ≦ a / b ≦ 2.5, and preferably 1 ≦ a / b ≦ 2.5.
It is more preferable that ≦ a / b ≦ 1.5.

In the present invention, the corners may be slightly rounded. The shape of the main plane and the length of the side can be easily determined and measured from electron micrographs of silver halide grains.

In the present invention, having grooves in the main plane parallel to the six sides of the main plane means that linear recesses (hereinafter also referred to as grooves) are formed inside the six sides constituting the main plane. ) In the main plane at positions parallel to the six sides. Here, having a groove inside the side means that the distance X from the side to the groove is 0 <X <L, where L is the distance to the main plane.
It means that they have a relationship.

The presence or absence of the groove on the main plane and its position can be easily determined from an electron micrograph of silver halide grains and the like.

The groove referred to in the present invention preferably has a width that can be observed with a scanning electron microscope, and the linear portion on either side a or b in FIG. of)
It is observed longer than the width. When grooves are connected to adjacent sides as shown in FIG. 2, the grooves are counted according to the number of corresponding sides (in this case, 2). In the present invention, it is preferable to have one parallel groove for any one side constituting the main plane. However, the term “parallel” in the present invention also includes a case where the formed angle is less than 5 degrees even when the respective extension lines of the groove and the side intersect.

In the silver halide emulsion of the present invention, 10% or more of the total projected area of the silver halide grains contained in the emulsion is occupied by the silver halide grains of the present invention. Here, “10% or more of the total projected area” means that 1000 or more silver halide grains contained in the emulsion are arbitrarily observed using an electron micrograph and the projected area of the silver halide grains corresponding to the present invention is determined. The sum means that the projected area of all the observed silver halide grains is 10% or more.

The projected area ratio of the silver halide grains of the present invention contained in the silver halide emulsion of the present invention is as follows.
It is preferably at least 30%, more preferably at least 60%.

The average aspect ratio of the silver halide grains contained in the silver halide emulsion of the present invention is preferably 3 or more, more preferably 5 or more. The aspect ratio is the ratio of the particle size to the thickness (aspect ratio = diameter /
Thickness). The particle size is represented by the diameter of a circle having an area equal to the area (projected area) when the particle is projected perpendicular to the main plane. Grain thickness is the thickness of a grain in a direction perpendicular to the major plane and generally corresponds to the distance between the two major planes.

The particle size and thickness can be determined by the following method. After preparing a sample coated with silver halide particles so that the main surface and the latex ball of known particle size as an internal standard are oriented in parallel on the support, and shadowed by carbon vapor deposition from a certain angle, A replica sample is prepared by a normal replica method. An electron micrograph of the sample is taken, and the projected area and thickness of each particle are determined using an image processing device or the like. In this case, the projected area of the particle can be calculated from the projected area of the internal standard, and the thickness of the particle can be calculated from the length of the internal standard and the shadow of the particle. The average value of the aspect ratio, the grain size, and the grain thickness is obtained by arbitrarily measuring 1,000 or more silver halide grains contained in the silver halide emulsion by using the above-described shadowing method, and calculating the arithmetic average thereof. Say.

The silver halide grains contained in the silver halide emulsion of the present invention preferably have a variation coefficient of both grain size and thickness of 20% or less. The variation coefficient of the grain size and grain thickness of the silver halide grains is a value defined by the following equation using the values obtained from the grain size and grain thickness measurements by the shadowing method.

Coefficient of variation of particle size (%) = (standard deviation of particle size / average value of particle size) × 100 Coefficient of variation of thickness (%) = (standard deviation of thickness / average value of thickness) × 100 The silver halide composition of the silver halide emulsion of the present invention is preferably silver iodobromide or silver chloroiodobromide. In particular, silver iodobromide containing 10 mol% or less of silver iodide is preferable. Further, the average silver iodide content of the silver halide emulsion is preferably from 0.5 mol% to 8 mol%, particularly preferably from 1 mol% to 6 mol%. The composition of the silver halide grains can be determined by a composition analysis method such as an EPMA method and an X-ray diffraction method.

The average silver iodide content of the surface phase of the silver halide emulsion of the present invention is preferably at least 1 mol%.
It is more preferably from 2 mol% to 20 mol%, and still more preferably from 3 mol% to 15 mol%.

The average silver iodide content of the surface phase of the silver halide grains is a value obtained by using the XPS method or the ISS method.

For example, the surface silver iodide content by the XPS method can be obtained as follows. The sample was placed at 1 × 10 ^-4 torr
After cooling to −155 ° C. or less in the following ultra-high vacuum, MgKa is irradiated as a probe X-ray at an X-ray source current of 40 mA, and Ag3d5 / 2, Br3d, and I3d3 / 2 electrons are measured. The integrated intensity of the measured peak is corrected by a sensitivity factor, and the composition such as the silver iodide content of the silver halide surface phase is determined from these intensity ratios.

The silver halide emulsion of the present invention preferably has substantially dislocation lines. Substantially having dislocation lines means that the silver halide grains contained in the emulsion have a total shadow area of 5%.
0% or more has dislocation lines. There is no particular limitation on the position where the dislocation line exists, but it is preferable that the dislocation line exists near the outer peripheral portion, near the ridge line, or near the vertex of the tabular silver halide grains. In terms of the positional relationship of dislocation introduction in the whole grain, it is preferable that the silver is introduced at 50% or more of the silver amount of the whole grain, more preferably between 60% and 95%, more preferably 70% or more. % Is most preferably introduced. Regarding the number of dislocation lines, grains containing 5 or more dislocation lines account for 50% of the total projected area.
It is preferably at least 70%, more preferably at least 70%, even more preferably at least 90%. In each case, it is particularly desirable that the number of dislocation lines is 10 or more.

Dislocation lines of silver halide grains are described, for example, in J. Am. F. Hamilton, Photo. Sci. E
ng. 11 (1967) 57 and T.I. Shiozaw
a, J. et al. Soc. Photo. Sci. Japan35
(1972) 213 can be observed by a direct method using a transmission electron microscope at a low temperature. That is, the silver halide grains taken out from the emulsion so as not to apply enough pressure to generate dislocations on the grains are placed on a mesh for an electron microscope so as to prevent damage by electron beams (such as printout). Observation is performed by a transmission method while the sample is cooled. At this time, the thicker the particle, the more difficult it is for an electron beam to pass through, so that a method using a high-pressure electron microscope can observe more clearly. From the grain photograph obtained by such a method, the position and number of dislocation lines in each grain can be determined.

In the silver halide emulsion of the present invention, the silver iodide content between silver halide grains is preferably more uniform. That is, the coefficient of variation of the silver iodide content in the silver halide emulsion is preferably 30% or less,
More preferably, it is 20% or less. The coefficient of variation as referred to herein is a value obtained by dividing the standard deviation of the silver iodide content by the average value of the silver iodide content and multiplying by 100. 1 in
A value obtained by measuring 000 or more pieces.

The silver halide grains for photography are microcrystals composed of silver chloride, silver bromide, silver iodide, or a solid solution thereof, and two or more phases having different silver halide compositions are contained in the crystal. It is possible to form. As a grain having such a structure, a grain composed of an inner core phase and an outer surface phase having mutually different silver halide compositions is known, and is generally called a core / shell type grain. The silver halide grains of the present invention preferably have a core / shell type grain structure in which the outer surface phase has a higher silver iodide content than the inner core phase.

As a method for producing a silver halide emulsion of the present invention, a method known in the art can be appropriately applied. For example, pAg of the reaction solution at the time of forming silver halide grains
, A controlled double jet method or a controlled triple jet method. In addition, a silver halide solvent can be used if necessary. Examples of useful silver halide solvents include ammonia, thioethers, and thioureas.

Regarding thioethers, US Pat.
No. 71,157, No. 3,790,387, No. 3,
No. 574,628 can be referred to.

The method for preparing the grains is not particularly limited, and an ammonia method, a neutral method using no ammonia, an acidic method, or the like can be used. From the viewpoint that fogging during silver halide grain formation can be suppressed. , Preferably p
It is preferable to form particles in an environment where H (the logarithm of the reciprocal of the hydrogen ion concentration) is 5.5 or less, more preferably 4.5 or less.

In order to more precisely control the silver iodide content between and within the silver halide grains, at least a part of the formation of the silver iodide-containing phase of the silver halide grains is more than that of the silver halide grains. It is desirable to carry out the reaction in the presence of silver halide grains having a low solubility, and it is particularly desirable to use silver iodide as the silver halide grains having a low solubility. For the same reason, a method of forming at least a part of the silver iodide-containing phase of silver halide grains by supplying only one or more types of silver halide fine grains is also preferable.

The method for introducing dislocation lines into silver halide grains is not particularly limited. For example, a method in which an aqueous solution of an iodide ion such as potassium iodide and a solution of a water-soluble silver salt are added by a double jet, or silver iodide is used. A method of adding fine particles,
A method of adding only an iodine ion solution;
A known method such as a method using an iodide ion releasing agent described in No. 81 can be used to form a dislocation at a desired position as a source of a dislocation line. Among these methods, a method of adding an aqueous iodide ion solution and a water-soluble silver salt solution by a double jet, a method of adding silver iodide fine particles, and a method of using an iodide ion releasing agent are preferable.
The method of adding silver iodide fine grains is most preferable.

The silver halide grains of the present invention preferably have a particle size in terms of volume of 0.1 to 1.2 μm, more preferably 0.20 to 0.8 μm.
m is more preferred. If it is less than 0.1 μm, it is difficult to obtain practical sensitivity, while if it is more than 1.2 μm, the granularity is significantly deteriorated due to the large particle diameter. Here, the volume-converted particle size is a value of the length of one side of a cube having the same volume as the silver halide grains.

In the silver halide emulsion of the present invention, Research Disclosure No. 308119
(Hereinafter abbreviated as RD308119) can be used.

The following shows the places to be described.

[0045]

[Table 1]

The silver halide emulsion of the present invention can be subjected to physical ripening, other chemical ripening and spectral sensitization according to a known method.

The additives used in such a step include Research Disclosure No. 17643,
No. 18716 and no. 308119 (respectively,
RD17643, RD18716, RD30811
9) can be used. The places to be described are shown below.

[0048]

[Table 2]

Known photographic additives which can be used in the present invention are also described in the above-mentioned Research Disclosure.
The places to be described are shown below.

[0050]

[Table 3]

Various couplers can be used in the present invention, and specific examples are described in the above-mentioned Research Disclosure.

The following are relevant descriptions.

[0053]

[Table 4]

The additive used in the present invention is RD3081
It can be added by the dispersion method described in 19XIV.

In the present invention, the aforementioned RD17643
28 pages, RD18716 pages 647-8 and RD308
The support described in 119XIX can be used.

The light-sensitive material of the present invention includes the aforementioned RD3081
An auxiliary layer such as a filter layer or an intermediate layer described in Item 19VII-K can be provided.
Various layer configurations such as a normal layer, a reverse layer, and a unit configuration described in section 08119VII-K can be employed.

The present invention can be applied to various color light-sensitive materials represented by general or movie color negative films, slide or television color reversal films, color papers, color positive films, and color reversal papers. .

The light-sensitive material of the present invention is obtained by using the above-mentioned RD17643.
Pages 28 to 29, RD18716647 and RD30
Development processing can be performed by the usual method described in 8119XIX.

[0059]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these embodiments.

(Preparation of Comparative Example Emulsion Em-1) A silver iodobromide emulsion having a cubic equivalent particle size of 0.24 μm and an average aspect ratio of 4.8 was used as a seed crystal emulsion, and Comparative Example Emulsion E was prepared in the following manner.
m-1 was prepared.

The following gelatin solution G-10 containing a seed crystal emulsion
While maintaining the temperature at 75 ° C., the S-10 solution and the X-10 solution were added by a double jet method using a mixing and stirring apparatus described in JP-A-62-160128. During this time, the pAg was controlled to 8.35 using a 1N aqueous potassium bromide solution.

(G-10) Seed Emulsion 0.711 mol equivalent Alkali-treated gelatin (average molecular weight 100,000) 126.0 g 10 wt% methanol solution of the following (Compound A) 2.00 ml Add H ₂ O 2800 0.0 ml (Compound A) HO (CH ₂ CH ₂ O) m (CH (CH ₃ ) CH ₂ O) _19.8 (CH ₂ CH ₂ O) nH (m + n = 9.77) (S-10) Silver nitrate aqueous solution (3 8.5N) 8.855 mol equivalent (X-10) A mixed aqueous solution of potassium bromide (92 mol%) and potassium iodide (8 mol%) (3.5 N) 8.855 mol equivalent After lowering the temperature to 60 ° C. and adjusting the pAg to 9.7 with a 3.5N aqueous potassium bromide solution, the S-11 solution and the X-11 solution were added in 2 minutes by a double jet method, and the mixture was aged for 2 minutes. went.

(S-11) Aqueous solution of silver nitrate (1.0 N) 0.268 mol equivalent (X-11) Aqueous potassium iodide solution (0.5 N) 0.268 mol equivalent 12 liquids and X-12
The liquid was added. During this time, the pAg was controlled to 10.1 using a 1N aqueous potassium bromide solution.

(S-12) Aqueous solution of silver nitrate (3.5N) 4.294 mol equivalent (X-12) An aqueous solution of a mixture of potassium bromide (97 mol%) and potassium iodide (3 mol%) (3.5 N) 4.294 molar equivalents Throughout the emulsion preparation, the rate of addition of each solution was appropriately controlled so that no new silver halide nucleation occurred and no Ostwald ripening between the growing grains occurred.
The pH was controlled at 5.0 using 0.5N nitric acid. After completion of the growth, desalting and washing are carried out according to a conventional method, and gelatin is added and dispersed well.
g was adjusted to 8.1. Observation of the silver halide grains contained in this emulsion using an electron microscope revealed that the grains were tabular silver halide grains having a hexagonal {111} plane on the principal plane and at least parallel to six sides of the principal plane. No tabular silver halide grains having six grooves in the main plane were included.

(Preparation of Comparative Example Emulsion Em-2) A silver iodobromide emulsion having a cubic equivalent particle size of 0.24 μm and an average aspect ratio of 4.8 was used as a seed crystal emulsion, and Comparative Example Emulsion E was prepared by the following method.
m-2 was prepared.

The following gelatin solution G-20 containing a seed crystal emulsion
While maintaining the temperature at 75 ° C., the S-20 solution and the X-20 solution were added by a double jet method using a mixing and stirring apparatus described in JP-A-62-160128. During this time, the pAg was controlled to 8.35 using a 1N aqueous potassium bromide solution.

(G-20) Seed Emulsion 0.711 mol equivalent Alkali-treated gelatin (average molecular weight 100,000) 126.0 g 10% by weight methanol solution of (Compound A) 2.00 ml H ₂ O was added and 2800 g 2.0 ml (S-20) Aqueous silver nitrate solution (3.5 N) 8.855 mol equivalent (X-20) Mixed aqueous solution of potassium bromide (92 mol%) and potassium iodide (8 mol%) (3.5 N) 8 After the above addition, the solution temperature was lowered to 40 ° C., the pAg was adjusted to 9.7 with a 3.5N aqueous potassium bromide solution, and then the S-21 solution and the X-21 solution were obtained by the double jet method. Was added for 2 minutes and aging was performed for 2 minutes.

(S-21) Aqueous solution of silver nitrate (1.0 N) 0.268 mol equivalent (X-21) Aqueous potassium iodide solution (0.5 N) 0.268 mol equivalent 22 liquid and X-22
The liquid was added. During this time, the pAg was controlled to 10.1 using a 1N aqueous potassium bromide solution.

(S-22) Aqueous solution of silver nitrate (3.5N) 4.294 mol equivalent (X-22) Aqueous solution (3.5N) of a mixed solution of potassium bromide (97 mol%) and potassium iodide (3 mol%) 4.294 molar equivalents Throughout the emulsion preparation, the rate of addition of each solution was appropriately controlled so that no new silver halide nucleation occurred and no Ostwald ripening between the growing grains occurred.
The pH was controlled at 5.0 using 0.5N nitric acid. After completion of the growth, desalting and washing are carried out according to a conventional method, and gelatin is added and dispersed well.
g was adjusted to 8.1. Observation of the silver halide grains contained in this emulsion using an electron microscope revealed that the grains were tabular silver halide grains having a hexagonal {111} plane on the principal plane and at least parallel to six sides of the principal plane. It was found that tabular silver halide grains having six grooves in the main plane accounted for less than 5% of the total projected area.

(Preparation of Emulsion Em-3 of the Present Invention) A silver iodobromide emulsion having a cubic equivalent particle size of 0.24 μm and an average aspect ratio of 4.8 was used as a seed crystal emulsion, and the emulsion E-3 of the present invention was prepared by the following method.
m-3 was prepared.

The following gelatin solution G-30 containing a seed crystal emulsion
While keeping the temperature at 75 ° C., the S-30 solution and the X-30 solution were added by a double jet method using a mixing and stirring apparatus described in JP-A-62-160128. During this time, the pAg was controlled to 8.35 using a 1N aqueous potassium bromide solution.

(G-30) Seed Emulsion 0.711 mol equivalent Alkali-treated gelatin (average molecular weight 100,000) 126.0 g 10% by weight methanol solution of the above (Compound A) 2.00 ml H ₂ O was added 2800 g 0.0ml (S-30) Silver nitrate aqueous solution (3.5N) 8.855 mole equivalent (X-30) Potassium bromide (92 mol%) and potassium iodide (8 mol%) mixed aqueous solution (3.5N) 8 After the above addition, the solution temperature was lowered to 40 ° C., the pAg was adjusted to 9.7 with a 3.5N aqueous potassium bromide solution, and then the S-31 solution and the X-31 solution were obtained by the double jet method. Was added for 2 minutes and aging was performed for 2 minutes.

(S-31) Aqueous solution of silver nitrate (1.0 N) 0.268 mol equivalent (X-31) Potassium iodide aqueous solution (0.5 N) 0.268 mol equivalent 32 liquids and X-32
The liquid was added. During this time, the pAg was controlled to 10.1 using a 1N aqueous potassium bromide solution.

(S-32) Aqueous solution of silver nitrate (3.5N) 1.610 mol equivalent (X-32) Aqueous solution of mixed solution of potassium bromide (97 mol%) and potassium iodide (3 mol%) (3.5 N) 1.610 mol equivalent After the completion of the above addition, the solution temperature was raised to 60 ° C., and the S-33 solution and the X-33 solution were added by a double jet method. During this time, the pAg of the solution was continuously changed to 8.2.

(S-33) Aqueous solution of silver nitrate (3.5N) 2.683 mol equivalent (X-33) Mixed aqueous solution of potassium bromide (97 mol%) and potassium iodide (3 mol%) (3.5 N) 2.683 mole equivalents Throughout the emulsion preparation, the rate of addition of each solution was appropriately controlled so that no new silver halide nucleation occurred and no Ostwald ripening between the growing grains occurred.
The pH was controlled at 5.0 using 0.5N nitric acid. After completion of the growth, desalting and washing are carried out according to a conventional method, and gelatin is added and dispersed well.
g was adjusted to 8.1. Observation of the silver halide grains contained in this emulsion using an electron microscope revealed that the grains were tabular silver halide grains having a hexagonal {111} plane on the principal plane and at least parallel to six sides of the principal plane. It was found that tabular silver halide grains having six major grooves on the main plane accounted for about 60% or more of the total projected area.

(Preparation of Emulsions Em-4 and 5 of the Present Invention) Emulsions Em-4 to 5 having the following characteristics were prepared by changing the emulsion Em-3 at 60 ° C. and the ripening time with pAg.

Em-4: tabular silver halide grains having a hexagonal {111} plane in the main plane, and having at least six grooves parallel to six sides of the main plane in the main plane. A silver halide emulsion in which silver halide grains account for about 30% or more of the total projected area.

Em-5: tabular silver halide grains having a hexagonal {111} plane in the main plane, and having at least six grooves parallel to six sides of the main plane in the main plane. A silver halide emulsion in which silver halide grains account for about 10% or more of the total projected area.

(Preparation of Photosensitive Material Sample) Emulsion Em-1
While maintaining the temperature at 52 ° C., the following sensitizing dyes S-1, S-
2, S-3 was added. After 20 minutes, sodium thiosulfate, chloroauric acid and potassium thiocyanate were added, and after aging, 1-phenyl-5-mercaptotetrazole and 4-hydroxy-6-methyl-1,3,3a,
Stabilized by adding 7-tetraazaindene. The amount of sensitizing dye, sensitizer and stabilizer added and the aging time are 1/200.
The sensitivity and fog relation during second exposure were set to be optimal. Em-1 which has been subjected to sensitization treatment, coupler MC described later
A coating solution was prepared by adding a general photographic additive such as a dispersion, a spreading agent, and a hardening agent obtained by dissolving P-1 in ethyl acetate and tricresyl phosphate and emulsifying and dispersing it in an aqueous solution containing gelatin. Coated on an undercoated cellulose triacetate film support according to a conventional method and dried to obtain a color photographic material sample No. 1 was produced. In the same manner, a light-sensitive material sample was prepared using each of the emulsions.

[0080]

Embedded image

Immediately after the preparation of these samples, each sample was used as a set and subjected to wedge exposure for 1/200 second for control. Similarly, 1/1000 for one set of samples
A 0 second wedge exposure was performed. After the exposure, the two sets of samples were developed according to the following processing steps.

(Processing Step) Processing Step Processing Time Processing Temperature Replenishment Color Developing 3 min 15 sec 38 ± 0.3 ° C. 780 ml Bleaching 45 sec 38 ± 2.0 ° C. 150 ml Fixing 1 min 30 sec 38 ± 2.0 ° C. 830 ml Stabilizing 1 min 38 ± 5.0 ° C. 830 ml drying 1 min 55 ± 5.0 ° C. - Note that the replenishing amount is a value per photosensitive material 1 m ^2.

The following color developing solutions, bleaching solutions, fixing solutions, stabilizing solutions and replenishers were used.

Color developing solution and color developing replenishing solution Developer replenishing solution 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 iodide Potassium 1.2 mg-Hydroxylamine sulfate 2.5 g 3.1 g Sodium chloride 0.6 g-4-Amino-3-methyl-N-ethyl-N-([beta] -hydroxylethyl) aniline sulfate 4.5 g 6.3 g Diethylenetriaminepentaacetic acid 3.0 g 3.0 g Potassium hydroxide 1.2 g 2.0 g Add water to make 1 liter, and add potassium hydroxide or 20%
The color developing solution is adjusted to pH 10.06 and the replenisher is adjusted to pH 10.18 using sulfuric acid.

Bleach and bleach replenisher Bleach replenisher replenisher water 700 ml 700 ml 1,3-diaminopropanetetraacetic acid ammonium (III) iron 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 To 1 liter, and adjust the pH of the bleaching solution to 4.4 and the pH of the replenishing solution to 4.0 using ammonia water or glacial acetic acid.

Fixing Solution and Fixing Replenisher Fixing Solution Replenisher 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 Aqueous solution using ammonia water or glacial acetic acid, pH 6.2
Then, the pH of the replenisher is adjusted to 6.5, and then water is added to make 1 liter.

Stabilizing Solution and Stabilizing Replenishing Solution Water 900 ml p-octylphenol ethylene oxide 10 mol adduct 2.0 g dimethylolurea 0.5 g hexamethylenetetramine 0.2 g 1,2-benzoisothiazolin-3-one 0.1 g siloxane (UCC L-77) 0.1 g ammonia water 0.5 ml water was added to make up to 1 liter.
Adjust to pH 8.5 with% sulfuric acid.

The sensitivity and fog of the obtained sample were measured using green light. The measuring method and conditions are shown below.

The relative sensitivity and relative fog were measured for each control sample. The relative sensitivity was determined by calculating the reciprocal of the exposure amount that gives a density of minimum density (Dmin) +0.2 in each sample. The relative value was set to 100 with the sensitivity of 1 being 100 (the larger the value, the higher the sensitivity). The relative fog was determined by measuring the density (= Dmin) of the unexposed portion of each sample. Dmi of 1
The relative value was set to an n value of 100 (the smaller the value, the lower the fog).

The evaluation of the high illuminance failure property was performed by evaluating the sensitivity (Dmin +
The difference between the sensitivity of the control sample (Dmin + the reciprocal of the exposure amount giving a density of 0.2) and the sensitivity of the control sample was determined. The value of the difference obtained in 1 is shown as a relative value with the value of 100 taken as a value (a smaller value means a higher illuminance failure is smaller).

Table 5 shows the results obtained for each sample.

[0092]

[Table 5]

From the results shown in Table 5, it can be seen that the silver halide emulsion of the present invention and the silver halide photographic material using the emulsion have high sensitivity, low fog, and low high illuminance failure. Further, it can be seen that the higher the projected area ratio of the silver halide grains of the present invention, the more remarkable the effect of the present invention.

[0094]

The silver halide emulsion and silver halide photographic light-sensitive material of the present invention are excellent in sensitivity and fog, and have an improved effect of high illuminance failure.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example in which a groove parallel to a side constituting a main plane of a tabular silver halide grain of the present invention is provided in the main plane.

FIG. 2 is a plan view showing another example of the tabular silver halide grains of the present invention having grooves parallel to the sides constituting the main plane on the main plane.

Claims (2)

[Claims] 1. A hexagonal # 1 in which 10% or more of the total projected area is a hexagon
A tabular silver halide grain having an 11 ° plane in a main plane, and comprising tabular silver halide grains having grooves parallel to six sides of the main plane in the main plane. Silver halide emulsion. 2. A silver halide photographic light-sensitive material comprising the silver halide emulsion according to claim 1 in at least one light-sensitive silver halide emulsion layer provided on a support. .