JPS6235341A - Silver halide photographic sensitive material - Google Patents

Abstract

PURPOSE:To obtain the title material having an excellent graininess and sharp ness and a broad exposing range by lowering an iodine content contd. in the most outer shell of a silver halide emulsion particle than that of an inner layer of the silver halide emulsion particle, and by specifying a silver density contg. in the silver halide emulsion layer. CONSTITUTION:The iodine content compdd. in the most outer layer of the silver halide particle is <=10mol%. The iodine contact contd. in the inner side from the most uuter shell of the silver halide particle is higher than that of the most outer shell thereof by >=6mol%. When the silver density (d) contg. in the precribed silver halide emulsion layer is expressed by the following relationship (d)=N/V, (d)>=4.0X10<-1>g/cm<2> wherein; N (unit g) (expressed in a weight of a metallic silve) is the total silver amount contd. in the silver halide emulsion layer, (unit cm<3>) V is a volume of the silver halide emulsion layer. If the prescribed silver density is too high, as the side effects such as the deterioration of the graininess and the increasement of a fog are easy to generate, the preferable silver density range is a range of 5.0X10<-1>-1.2g/cm<3>. Said range is the most preferable for a blue sensitive emulsion layer.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention provides an internal core consisting essentially of silver bromide and/or silver iodobromide, and an internal core provided outside the internal core and consisting essentially of silver bromide and/or silver iodobromide. The present invention relates to a silver halide photographic light-sensitive material containing negative-working silver halide grains having a plurality of outer shells made of silver oxide and/or silver iodobromide.

BACKGROUND OF THE INVENTION In recent years, there has been a demand for silver halide photographic materials, especially silver halide photographic materials for photographing, that have high sensitivity and excellent image quality. In particular, in recent years in this industry, as the format of negative photography has shrunk due to the spread of compact cameras that are convenient to carry, it has become desirable for small format screens to have the same image quality as those enlarged from large format screens. It became so. That is, there is a strong desire to develop a silver halide photographic material that does not lose its granularity and sharpness even when the magnification during printing increases.

In order to improve sharpness, it is necessary to significantly reduce light scattering in the emulsion film. It is known that this technique involves coarsening the grain size of silver halide emulsion grains to a region where light scattering is small and drastically reducing the amount of coated silver. It is clear that the number of development active sites decreases due to coarsening and the like, leading to deterioration of graininess.

Furthermore, in order to reduce light scattering in the emulsion film, a method is known in which dyes are used to improve sharpness by preventing irradiation and Halley silane. This will cause the color balance to collapse.

In order to improve the graininess, a technique is known in which the grain size of silver halide grains is made smaller to make the coloring dye cloud smaller, but this technique causes a significant decrease in sensitivity.

OBJECTS OF THE INVENTION An object of the present invention is to provide a silver halide photographic material having excellent graininess, sharpness, and a wide exposure range.

20 Structure of the invention and its effects, that is, the present invention comprises an inner core consisting essentially of silver bromide and/or silver iodobromide, and an inner core provided outside the inner core and consisting essentially of silver bromide and/or silver iodobromide. /or a silver halide photographic material containing negative-working silver halide grains having a plurality of outer shells made of silver iodobromide, wherein the iodine content of the outermost shell of the silver halide grains is 10 mol% or less An iodine-rich shell having an iodine content higher than that of the outermost shell by 6 mol % or more is provided inside the outermost shell, and the silver density (d) of the predetermined silver halide emulsion layer is.

d=N/V [However, N is the total amount of silver (converted to metallic silver) in the βllV silver halide emulsion layer (unit: 1), and Volume (unit: cIrL
3) is shown. ], d≧4. OX10
-'97 cm''.

In the present invention, the volume of the emulsion layer is expressed as the product of the coating area and the dry film thickness.

When there are two or more emulsion layers in the present invention, the amount of silver and the film thickness are calculated based on the total amount of silver in each emulsion layer.

The above-mentioned silver density in the present invention should be 4X10't/x" or more in order to achieve the object of the present invention. However, if the silver density is too high, side effects such as deterioration of graininess and increase of fog may occur. Since this occurs easily, the silver density is 2.0t/
llXm” or less, more preferably 5.0×l
The silver density is in the range of Cr1t/33 or more and 1.2t/cIL" or less. In particular, this silver density is suitable for the blue-sensitive emulsion layer. For the green-sensitive emulsion layer, the silver density is 6.5 within the above range.
X I G” t/[” or more is desirable, and 6
．． 5 x 1O-1-a2597cm” is even better, 8
．． OX 10-' ~2, O2/cr113 is particularly good.

Further, the dry film thickness of the present invention is 4.0 μm or less and 6.0 μm or less in each of the blue-sensitive and green-sensitive layers, respectively.
It is better if the dry film thickness is below, but if the dry film thickness is too thin,
Since side effects such as deterioration of coating properties, pressure characteristics, emulsion stability, and decrease in color density occur, the dry film thickness of each photosensitive layer should be 0.8 to 4.0 μm, and 1.2 to 1.2 μm, respectively. 6.0
μm is preferable, more preferably 1.0 to 3.8 μm, respectively.
μm, in the range of 1.5-5.7 μm.

Note that each of the blue-sensitive layer and the green-sensitive layer may be composed of one layer or two or more layers, and at least one layer each may contain the above-mentioned silver halide grains.

Furthermore, at least one of these photosensitive layers can contain the silver halide grains of the present invention.

In the present invention, the method for measuring the amount of silver for determining the silver density is based on atomic absorption spectrometry. Furthermore, as for the film thickness, which determines the volume of the emulsion layer, the cross section of the dried sample is photographed under magnification using a scanning electron microscope, and the film thickness of each layer is measured.

On the other hand, the silver halide grains used in the present invention are
As described above, there is an inner core consisting essentially of silver halide and/or silver iodobromide, and a plurality of outer cores provided outside the inner core and consisting essentially of silver bromide and/or silver iodobromide. In a silver halide photographic material containing negative-working silver halide grains having a shell, the outermost shell of the silver halide grain has an iodine content of 10 mol% or less, and has a higher iodine content than the outermost shell. A high iodine content shell having a high iodine content of 6 mol% or more (hereinafter referred to as a high iodine shell) is provided inside the outermost shell, and preferably, the outermost shell and the high iodine shell are An intermediate shell having an iodine content between these two shells is provided between them, and the iodine content of the intermediate shell is 3 mol% or more higher than the outermost shell, and the iodine content of the high iodine content shell is is higher than that of the intermediate shell by 3 mol% or more.

In the silver halide composition of the halogenated shunt grains according to the present invention, the above-mentioned "consisting essentially of" means silver bromide or iodine to the extent that the effects of the present invention are not impaired. This means that silver halide other than silver chloride, such as silver chloride, may be contained. Specifically, in the case of silver chloride, the proportion thereof is preferably 1 mol % or less.

The features of the photographic light-sensitive material according to the present invention can be summarized as follows (1) to (6).

(x+, by increasing the silver density to d≧4.0 , sharpness can be improved.

(2), silver density d≧4. OX 10-' f/cr
n'', the amount of silver can be increased without increasing the dry film thickness of the emulsion layer, so graininess can be improved without deteriorating sharpness.Moreover, interimage can be improved without deteriorating sharpness. The effectiveness, desilvering properties, and sensitivity are also improved.

(3) By using an emulsion containing core/shell type silver halide grains with a high iodine shell on the inside, superior graininess and a wide exposure range can be obtained (compared to non-core/shell type emulsions). It will be done.

(4) The iodine content of the high iodine shell is preferably 6 to 40 mol%, and is higher than the outermost shell layer by 6 mol% or more, but if this content is less than 6 mol% (or the outermost shell layer If the amount is less than 6 mol %), the sensitivity will decrease, and if it exceeds Tochi mol %, polydispersity will occur, and from the viewpoint of sensitivity and sharpness, 40 mol %
It is preferable not to exceed.

(5) If the iodine content in the entire silver halide grain is too high, developability will be poor and sensitivity will be lowered; if it is too low, the gradation will be too hard, the exposure area will be narrow, and grain Therefore, it is preferable to select a specific range.

(6) Monodisperse emulsions are better in sensitivity, sharpness, and fog-sensitivity relationships than polydisperse emulsions. In other words, in polydispersion, the shell-forming reaction is non-uniform, making it difficult to form an ideal core/shell structure, the presence of microparticles that degrade sharpness, and chemical sensitization after particle formation. Since the optimum conditions differ depending on the individual grains, the sensitivity tends to be low and the Capri-sensitivity relationship tends to deteriorate, so monodisperse emulsions are preferably used.

How to further improve the excellent effects mentioned above! h: Iodine content of high iodine shell (mol%) - Iodine content of intermediate shell (
mole%)! l: When the iodine content of the outermost shell (mol%), Δ
I = 1 B, -1j>8 mol%, ΔIh 1h-
1+y > 4 mol%, Δ17-1. -11 >4 mol%, Δ14 >10 mol%, Δ11>
It is even better to set it to 4 mol%, ΔL/>4 mol%.

Here, the content is preferably 11-0 to 5 mol%, more preferably 0 to 2 mol%, and more preferably 0 to 1 mol%. Further, 1 is preferably 6 to 40 mol%, and even more preferably 10 to 40 mol% ((4) above).

In addition, the volume of the outermost shell is 4 to 70 mol% of the entire particle.
, 10 to 50 mol% is more preferable. The volume of the high iodine shell is preferably 10 to 80% of the whole grain, and 20% to 80% of the whole grain.
-50%, more preferably 20-45%.

The volume of the intermediate shell is 5 to 60% of the whole particle, and even 20 to 60%.
55% is good. The high iodine shell may be at least a part of the inner shell, but preferably a separate inner core exists inside the high iodine shell.

The iodine content of the internal core is preferably 0 to 40 mol%, and 0 to 10
Mol% is preferred, and 0 to 6 mol% is more preferred. The particle size of the inner core is 01) 5-0.8 μm, furthermore 0.05~
0.4 μm is good.

In addition, in the characteristic point (5) above, the iodine content in the entire particle is preferably 1 to 30 mol%, preferably 1 to 2 mol%.
The content is desirably 5 mol%, more preferably 2 to 20 mol%.

Regarding the characteristic point (6) above, the particle size distribution of the particles may be either polydisperse or monodisperse, but it is preferable that the coefficient of variation of the particle size distribution be a monodisperse emulsion of less than %, and furthermore, It is preferable that the coefficient of variation be 15% or less. This coefficient of variation is defined as , and is a measure of monodispersity.

As a multilayer color light-sensitive material having the characteristic point (7) above, the multilayer is constituted by three or more emulsion layers consisting of three types of light-sensitive layers: a blue-sensitive layer, a green-sensitive layer, and a red-sensitive layer, and a blue-sensitive layer, It is desirable that at least one emulsion layer of the green-sensitive layer contains the silver halide grains according to the present invention (or as described above).

The grain size of the silver halide grains (defined as the length of one side of a cube with the same volume as the silver halide grains) is 0, 3.0 μm.
It is better to set it to m. Moreover, the shape may be any of an octahedron, a cube, a sphere, a flat plate, etc., but an octahedron is preferable.

To further describe the layer structure of the silver halide grains according to the present invention, as described above, the internal core and the high iodine shell may be the same, or the internal core may be provided separately inside the high iodine shell. It's okay to be beaten. The inner core and the high iodine shell, the high iodine shell and the middle shell, and the middle shell and the outermost shell may be adjacent to each other, or there may be at least one layer of another shell having an arbitrary composition between each shell. (This is called an arbitrary shell).

These arbitrary shells may be a single shell with a uniform composition, a shell group consisting of multiple shells with a uniform composition whose composition changes in a stepwise manner, or continuous shells within an arbitrary shell. It may be a continuous shell whose composition changes, or it may be a combination of these. Further, there may be a plurality of high-iodity shells and intermediate shells, or there may be only one set.

Next, an example of the layer structure of silver halide grains according to the present invention will be explained. The iodine content is indicated by I.

1. Three-layer structure iodine content of inner core-high iodine shell Shell diameter core (third) (inner core-high iodine shell) 1. -1. >3 mol% 13 -15 mol% 1
．． 2μm second shell (intermediate shell) 1, -1. >3 mol% 1. Rich 5 mol% 1.4
/Am#! 1 shell (outermost shell) 1. -0 to 10 mol% I -0.5 mol% 1.
6/Jm2 A fourth layer of arbitrary composition between the inner core and the high-iodide shell
, 6-layer structure including 5th shell Iodine content Shell diameter core (6th) (inner core) Arbitrary 1. -4.0 mol% 0.1
/Jm 5th shell (arbitrary shell) arbitrary lm=2.0 mol% 0.27
/Am 4th shell (arbitrary shell) Arbitrary 1. -2.6 layer% 0.8 μm 3rd shell (high iodine shell) 1, -1>3 mol% I, = 15.0 mol% 1.
12, ljm second shell (intermediate shell) 1, -1. >3 mol% l, = 5.0 mol% 1.44 μm first shell (outermost shell) 1, -0 to 10 mol% I, -9, 5 mol% 1
．． 6 μm3, with an optional fifth layer between the inner shell and the high iodine shell.
7-layer structure with 6th shell and 2 intermediate shells between outermost shell and high iodine shell Iodine content Shell diameter 7th shell (inner core) 1, = 4 mol% 0.10 μm 6th shell (Arbitrary shell) Arbitrary l6-2 mol% 0.27/A
m5th shell (optional shell) Arbitrary! ,=8 mol% 0.8 μm
Fourth shell (high iodine shell) 1-1. >3 mol% I, -15 mol% 1.12 μ
m Third shell (middle shell) 1 −1 >3 mol% I, = 8 mol% 1.24μ
mIa -13>3 mol% 2nd shell (middle shell) 1st shell (outermost shell) 1, -0 to 10 mol% 1m-0,5 mol% 1.6
μm4, any 6th and 7th shells between the inner shell and the high-iodity shell, and 1 between the high-iodity shell (5th shell) and the intermediate shell (3rd shell)
8-layer structure with arbitrary shell (4th shell) of layer, and 1 layer of arbitrary shell (2nd shell) between intermediate shell (3rd fa) and outermost shell Iodine content Shell diameter 8th shell (inner core ) Any rs=4 mol% 0.10/
jm 7th shell (optional shell) Arbitrary 1. -2 mol% 0.27μ
m 6th shell (optional shell) Arbitrary ■. -4 mol% 0.8 μm
Fifth shell (high iodine shell) 1m-13>3 mol% I5-15 mol% 1.12
ttm 4th shell (optional shell) Optional I4111I 9 mol% 1.24 μm 3rd shell (intermediate shell) 1, -1. -3 mol% I1 = 5 mol/L/X
1.44 μm 2nd shell (arbitrary shell) Arbitrary lx = 4.5 mol% 1.50 ttm 1st shell (outermost shell) 1, = O ~ 10 mol% I+ = 2 mol% 1.6
am5, structure with multiple high iodine shells Iodine content Shell diameter 6th shell (inner core) Arbitrary Is = 4 mol%
0.10μ, m 5th shell (high iodine shell) 1, -1. >3 mol% l5=15 mol% 0
．． 27μml, -1. >6 mol% 4th shell (optional shell) Arbitrary 1a Ms 5 mol%
0.80 μm third shell (high iodine shell) 1, -1. >3 mol% In-15 mol% 1.
12μm1, -1. >6 mol% Second shell (intermediate shell) 1, -1. >3 mol% I, -5 mol% 1.
44 fim first shell (outermost shell) 1, = O ~ 10 mol% I, = 0.3 mol% 1.6
The inner core of the silver halide grains of the present invention having a diameter of 0 μm is described in Chimie et Ph Photographic by Glafkides, P.
ysique.

Photohraphique) (Paul Montel, 1967),
Photographic Immulsion Chemistry (Photog) by G, F, Duffin
rapic Emulsion Chemistry
) (The Focal P
ress), 1966), Making and Coating Ph
It can be prepared using the method described in ``Otograhic Emulsion'' (published by The Focal Press, 1964). That is, any of the acidic method, neutral method, ammonia method, etc. may be used, and the method for reacting the soluble silver salt with the soluble halogen salt may be any one-sided mixing method, simultaneous mixing method, or a combination thereof. good.

It is also possible to use a method in which particles are formed in an excess of silver ions (so-called back-mixing method).

As one type of simultaneous mixing method, a method in which the pAg in the liquid phase in which silver halide is produced can be kept constant, that is, a so-called Chondrald double jet method can also be used. According to this method, a silver halide emulsion having a regular crystal shape and a nearly uniform grain size can be obtained.

Although two or more types of silver halide emulsions formed separately may be used as a mixture, it is preferable to use the double jet method or the Chondrold double jet method.

The pAg when preparing the inner core varies depending on the reaction temperature and the type of silver halide solvent, but is preferably 2 to 11. Further, it is preferable to use a halogen silver oxide solvent because the grain formation time can be shortened.
For example, commonly known silver halide solvents such as ammonia and thioethyl can be used.

The shape of the internal core may be plate-like, monospherical, twin-crystalline, octahedral, cubic, tetradecahedral, or mixed.

In addition, to make the particle size uniform, British Patent No. 453 to 016, Japanese Patent Publication No. 48-36890, British Patent Publication No. 52-1636
As described in No. 4, there is a method of changing the addition rate of silver nitrate or alkali halide aqueous solution depending on the grain growth rate, and US Pat.
It is preferable to use a method of changing the concentration of an aqueous solution as described in Japanese Patent No. 158124 to grow rapidly within a range that does not exceed the critical saturation level. These methods do not cause re-nucleation and each silver halide grain is coated uniformly, so they are preferably used when introducing any number of high iodine shells, intermediate shells, and outermost shells.

In the middle of the high iodine shell and the inner shell of the silver halide grains of the present invention, one or more gates may be provided as necessary. This high iodine shell can be provided by a conventional halogen substitution method, a method of coating with silver halide, etc. after subjecting the formed inner core or an arbitrary number of inner shells to a desalting step, if necessary.

The halogen substitution method can be carried out, for example, by adding an aqueous solution consisting mainly of an iodo compound (preferably potassium iodo), preferably at a concentration of 10% or less, after the internal core is formed. For details, see U.S. Patent No. 2,592,250, No. 4,0
This can be carried out by the methods described in Japanese Patent Application Laid-open No. 75,020, Japanese Patent Application Laid-Open No. 55-127549, and the like.

At this time, in order to reduce the difference in iodine distribution between grains of high iodine shells, it is desirable to reduce the concentration of the iodine compound bath solution to 10@-8 mol % or less and add over 10 minutes.

Further, as a method for newly coating the inner core with silver halide, it can be carried out, for example, by simultaneously adding a halide bath solution and a silver nitrate aqueous solution, that is, by a simultaneous mixing method or a controlled double jet method. For details, see JP-A No. 53-22408, JP-A No. 43-
No. 13162, Japanese Unexamined Patent Publication No. 14829/1983, J Photo Science (J, Photo, Sc
I, ), 24, 198 (1976).

pAg when forming a high iodine shell is the reaction temperature,
Although it varies depending on the type and amount of the silver halide solvent, it is preferable to use the internal core material S as described above.
When using ammonia as a solvent, 7 to 11 are preferable.

Methods for forming high iodine shells include simultaneous mixing method,
Controlled double jet method is more preferred.

The intermediate shell of the silver halide grains of the present invention includes a high-iodide shell having a high-iodide shell on the surface, or a high-iodide shell having one or more arbitrary numbers on the high-iodide shell as necessary, and an inner core. The outer surface of the grains containing iodine can be further coated with silver halide having a halogen composition different from that of the high iodine shell by a simultaneous mixing method or a controlled double jet method.

For these methods, the above-mentioned method of providing a high iodine shell can be similarly used.

The outermost shell of the silver halide grains of the present invention includes an intermediate shell, a high iodine shell, and an inner core having an intermediate shell on the surface or having one or more arbitrary numbers on the intermediate shell as necessary. The outer surface of the grain containing the iodine layer can be further coated with silver halide having a halogen composition different from that of the high iodine shell and the intermediate shell by a simultaneous mixing method or a controlled double jet method.

Regarding these methods, the above-mentioned method of providing a high iodine shell is similarly used.

An arbitrary number of layers can be provided between the inner core and the high iodine shell, between the high iodine shell and the intermediate shell, and between the intermediate shell and the outermost shell, as necessary, or there is no need to provide any special layer. good. For these arbitrary numbers, the above-mentioned method of providing a high iodine shell can be similarly used. In the inner shell, high iodine shell, intermediate shell, outermost shell, and any number of adjacent shells at each position, a desalination step may be carried out according to a conventional method as necessary during the preparation of adjacent shells, or The shells may be formed continuously without performing any steps.

The iodine content of each coating shell of the silver halide grains of the present invention is 1, for example, J, 1. Goldstein (
Goldatein, D.B., Wil
liams [X-ray analysis in rTEM/ATEM” Scanning Electron Fist Microscope (19
77), Vol. 1 (IIT Research Institute, p. 651 (March 1977)).

The silver halide grains as the final product after the formation of the outermost shell of the present invention are freed from excess halogen compounds generated during preparation or by-products or unnecessary salts and compounds such as nitrates and ammonia from the dispersion medium of the grains. May be removed.
The removal method can be the Tardel water washing method or dialysis method commonly used for general emulsions, or inorganic salts, anionic surfactants, anionic polymers (e.g. polystyrene sulfonic acid), or gelatin derivatives (e.g. acylated gelatin, carbamoylated gelatin, etc.). ), a flocculation method, etc. can be used as appropriate.

The core/shell type silver halide grains of the present invention can be optically sensitized to a desired wavelength range.

1. There are no particular restrictions on the optical sensitization method; for example, optical sensitization may be performed using an optical sensitizer such as a cyanine dye such as a zeromethine dye, a monomethine dye, a dimethine dye, or a trimethine dye, or an optical sensitizer such as a merocyanine dye, either alone or in combination. can do. Combinations of sensitizing dyes are often used, especially for the purpose of supersensitization. Along with the sensitizing dye, the emulsion may contain a dye that itself does not have a spectral sensitizing effect or a substance that does not substantially absorb visible light and exhibits supersensitization. U.S. Patent 2 describes these technologies.
, No. 545 to 68, No. 2,912,329, No. 3, 3
No. 97,060, No. 3,615β35, No. 3,628
, No. 964, British Patent No. L195,302, Ibid., 24
μs No. 88, μs No. 29 Tame No. 862, West German patent (0LS)
No. 2,030,326, Prefectural No. 21,780, Special Publication No. 43-4936, No. 44-14030, Research.
Disclosure ar (Re5earch Discl
osure) Vol. 176, 17643 (published December 1978), page 23, Section 1, etc. The selection can be arbitrarily determined depending on the wavelength range to be sensitized, sensitivity, etc., and the purpose and use of the photosensitive material.

The core/shell type silver halide crystals of the present invention can be subjected to various chemical sensitization methods that are applied to general emulsions.

For chemical sensitization, use a bar freezer (H.

Fr1eser) Edited by Die Grundlagen der.
Fotokrafischen Brotsese Mitzi/L/
Bar Halogenide 7 (Die Grund l
agender Photography
Prozesse mitSilberhaloge
niden) (Akademische Verlagsgesellschaft)
ese order schaft), 1968)
The method described on pages 675-734 can be used. That is, a sulfur sensitization method using a compound containing sulfur that can react with silver ions or active gelatin, a reduction sensitization method using a reducing substance, a noble metal sensitization method using gold or other noble metal compounds, etc. are used alone or in combination. be able to.

As the sulfur sensitizer, thiosulfates, thioureas, thiazoles, rhodanines, and other compounds can be used, and specific examples thereof are described in U.S. Pat. No. 1,574,94.
No. 4, Mu No. 410,689, No. 2,278,947, 2
, No. 728,668, No. 3,656,955, 4032
．． No. 928, No. 4.067.740.

As the reduction sensitizer, stannous salts, amines, hydrazine derivatives, formamidine sulfinic acid, silane compounds, etc. can be used, and specific examples thereof are described in U.S. Pat.
No. 487.850, No. 3419.974, 2,518,
No. 698, No. 2.983609, No. 2.98%610,
No. 2,694,637, No. 3,93q867, No. 4,05
No. 4,458. For noble metal sensitization, in addition to total complex salts, complex salts of metals in group I of the periodic table, such as platinum, iridium, and palladium, can be used. Specific examples thereof include U.S. Pat.
No. 613061, British Patent No. 613061, etc.

The silver salt particles of the present invention can be produced using a combination of two or more of these chemical sensitization methods.

Additionally, photosensitive layers containing the particles may be present on both sides of the support.

Various dopants can be doped during the formation of each shell of the core/shell emulsion of the present invention. Examples of this internal dopant include silver, sulfur, iridium,
Gold, platinum, osmium, rhodium, tellurium, selenium, cadmium, zinc, lead, thallium, iron, antimony,
Contains bismuth, arsenic, etc.

In order to dope with these dopants, water-soluble salts or complex salts of each type can be present at the time of formation.

As the binder for the core/shell type silver halide grains according to the present invention or the dispersion medium used in their production, hydrophilic colloids commonly used in silver halide emulsions are used. Hydrolytic colloids include not only gelatin (either lime-treated or acid-treated) but also gelatin derivatives such as those described in US Pat. Gelatin derivatives made by reaction with anhydrides, isocyanates, and 1,4-diketones, US Pat. No. 3
Gelatin derivatives produced by the reaction of gelatin and trimellitic anhydride as described in Japanese Patent Publication No. 118766, gelatin derivatives produced by the reaction of gelatin with an organic acid having an active halogen as described in Japanese Patent Publication No. 39-5514; Gelatin derivatives obtained by reacting aromatic glycidyl ether with gelatin as described in US Pat. , UK Patent 1,033,189
Polyoxyalkylene derivatives of gelatin described in U.S. Pat.
Esters with alcohols or polyhydric alcohols, also amides,
Acrylic (or methacrylic) nitrile, styrene, or other vinyl threads grafted onto gelatin, singly or in combination; synthetic hydrophilic polymeric substances such as vinyl alcohol, N-vinylpyrrolidone, hydroxyalkyl (meth) Homopolymers containing monomers such as acrylate, (meth)acrylamide, and N-substituted (meth)acrylamide, or copolymers of these with each other;
Copolymers of these with (meth)acrylic acid esters, vinyl acetate, styrene, etc., copolymers of any of the above with maleic anhydride, maleamic acid, etc.; natural hydrophilic polymer substances other than gelatin, such as casein , agar,
Alginate polysaccharides and the like can also be used alone or in combination.

The silver halide photographic emulsion containing core/shell type silver halide grains according to the present invention may contain various commonly used additives depending on the purpose.

These additives include, for example, azoles or imidazoles, such as benzothiazolium salts, nitroindazoles, nitrobenzimidazoles, chlorobenzimidazoles, bromobenzimidazoles, mercaptothiazoles, mercaptobenzthiazoles,
Mercaptobenzimidazoles, mercaptothiadiazoles; triazole notes, such as aminotriazoles, benzotriazoles, nitrobenzotriazoles; tetrazole notes, such as mercaptotetrazoles (1-phenyl-5-mercaptotetrazole in @); mercaptopyrimidines ; mercaptotriazines, e.g. thioketo compounds such as oxazolinthione; azaindenes, e.g. triazaindenes, tetraazaindenes (especially 4-hydroxy substituted (le ”
t3 a,? ) Tetraazaindenes), pentaazaindenes; Contains stabilizers and antifoggants such as henzenethiosulfonic acid, benzenesulfinic acid, benzenesulfonic acid amide, imidazolium salts, tetrazolium salts, polyhydroxy compounds, etc. I can do things.

The photographic light-sensitive material using the core/shell type emulsion of the present invention may contain an inorganic or organic hardening agent in the photographic emulsion layer and other hydrophilic colloid layers. For example, chromium salts (chromium alum, chromium acetate, etc.), aldehydes (formaldehyde, glyoxal, geltaraldehyde, etc.)
, N-methylol compounds (dimethylol urea, methylol dimethyl hydantoin, etc.), dioxane derivatives (2
゜3-dihydroxydioxane, etc.), active vinyl compounds (1,3,5-1-lyacryloyl-hexahydro-
8-triazine, 1,3-vinylsulfonyl-2-propanol, etc.), active halogen compounds (2,4-dichloro-6-hydroxy-8-triazine, etc.), mucohalogen acids (mucochloric acid, mucovinoxy chloric acid, etc.) can be used alone or in combination.

The four true sensitizers using the core/shell type emulsion of the present invention include:
The photographic emulsion layer and other hydrophilic colloid layers may contain a dispersion of a synthetic polymer that is insoluble or sparingly soluble in water for the purpose of improving dimensional stability. For example, alkyl (
meth)acrylate, alkoxyalkyl(meth)acrylate, glycidyl(meth)acrylate, (meth)
Acrylamide, vinyl esters (e.g. vinyl acetate), acrylonitrile, olefins, styrene, etc. alone or in combination, or together with acrylic acid, methacrylic acid, α,β-unsaturated dicarboxylic acids, hydroxyalkyl (meth)acrylates, sulfoalkyl A polymer containing a combination of (meth)acrylate, styrene sulfonic acid, etc. as a monomer component can be used.

The silver halide photographic material according to the present invention may optionally contain a development accelerator such as benzyl alcohol or a polyoxyethylene compound; an image stabilizer such as a chroman type, a claman type, a bisphenol type, or a phosphite type; wax,
It may contain lubricants such as glycerides of higher fatty acids and higher alcohol esters of higher fatty acids, development regulators, developing agents, plasticizers, and whitening agents. Surfactants that may be included include coating aids, permeability improvers for processing liquids, etc.
Anionic, cationic, nonionic, or amphoteric antifoaming agents or materials for controlling various physical properties of photosensitive materials can be used. As the antistatic agent, diacetyl cellulose, styrene perfluoroalkyl sodium maleate copolymer, alkali salt of a reaction product of styrene-maleic anhydride copolymer and p-aminobenzenesulfonic acid, etc. are effective.

Examples of matting agents include polymethyl methacrylate, polystyrene, and alkali-soluble polymers.

It is also possible to use colloidal silicon oxide.

Further, examples of the latex added to improve the physical properties of the film include copolymers of acrylic esters, vinyl esters, etc. and other monomers having ethylene groups. Gelatin plasticizers include glycerin and glycol compounds, and thickeners include styrene.
Sodium maleate copolymer, alkyl vinyl ether
Examples include maleic acid copolymers.

The emulsion containing silver halide grains of the present invention can have a rich latitude by mixing at least two types of emulsions having different average grain sizes and different sensitivities, or by coating the emulsion with an image layer.

The core/shell type silver halide emulsion according to the present invention is suitable for black and white general use, X-ray use, color use, infrared use, micro use, silver dye bleaching method, reversal use, diffusion transfer method, high contrast use, photo It can be effectively applied to photographic materials for various purposes such as thermography and heat-developable materials, but is particularly suitable for high-sensitivity color materials.

In order to apply the core/shell type silver halide emulsion according to the present invention to a color photographic light-sensitive material, an emulsion containing the above-mentioned crystals of the present invention adjusted to have red sensitivity, green sensitivity and blue sensitivity is added to cyan, magenta and Techniques and materials used for color photosensitive materials may be used, such as incorporating a combination of yellow couplers. For example, magenta couplers include 5-pyrazolone couplers, pyrazolobenzimidazole couplers, pyrazolotriazole couplers, cyanoacetylcoumaron couplers, open-chain acylacetonitrile couplers, and yellow couplers include acylacetamide couplers (e.g., benzoylacetanilides, Examples of cyan couplers include naphthol couplers and phenol couplers. These couplers are preferably non-diffusive and have a hydrophobic group called a ballast group in the molecule. The coupler is 4-equivalent or 2-equivalent to silver ion.
Either equivalence is acceptable. It may also be a colored coupler that has a color correction effect or a coupler that releases a development inhibitor during development (colorless DIR coupler). In addition to the DIR coupler, the coupling reaction product may include a colorless DIR coupling compound which is colorless and releases a development inhibitor.

In carrying out the present invention, the following known anti-fading agents may be used in combination, and color image stabilizers may be used alone or in combination of two or more. Known antifading agents include hydroquinone derivatives, gallic acid derivatives, p-alkoxyphenols, p-oxyphenol derivatives, and bisphenols.

The photosensitive material of the present invention may contain an ultraviolet absorber in the hydrophilic colloid layer. For example, benzotriazole compounds substituted with aryl groups, 4-thiazolidone compounds, benzophenone compounds, cinnamic acid ester compounds, butadiene compounds, benzoxazole compounds, and ultraviolet absorbing polymers can be used. These ultraviolet absorbers may be fixed in the hydrophilic colloid layer.

The photosensitive material of the present invention may contain a water-soluble dye in the hydrophilic colloid layer as a filter dye or for irradiation prevention or other purposes. Such dyes include oxonol dyes, hemioxonol dyes, styryl dyes, merocyanine dyes, cyanine dyes and azo dyes.

Among them, oxonol dyes, hemioxonol dyes and merocyanine dyes are useful.

The photosensitive material of the present invention uses hydroquinone derivatives, aminephenol derivatives, gallic acid derivatives,
It may also contain ascorbic acid derivatives.

The invention is also applicable to multilayer, multicolor photographic materials having at least two different spectral sensitivities on the support.

Multilayer natural color photographic materials usually have a red-sensitive emulsion layer on a support,
It has at least one green-sensitive emulsion layer and at least one blue-sensitive emulsion layer. The order of these layers can be arbitrarily selected as necessary. Usually, the red-sensitive emulsion layer contains a cyan-forming coupler, the green-sensitive emulsion layer contains a magenta-forming coupler, and the blue-sensitive emulsion layer contains a yellow-forming coupler.
Different combinations may be used depending on the case.

In the photographic material of the present invention, the photographic emulsion layer and other hydrophilic colloid layers can be coated on the support or on other layers by any known coating method.

For coating, a tip coating method, a roller coating method, a curtain coating method, an extrusion coating method, etc. can be used. The methods described in U.S. Pat. Nos. 2,681,294, 2,761,791, and 3,526,528 are advantageous.

Supports for photographic light-sensitive materials include, for example, baryta paper, polyethylene-coated paper, polypropylene synthetic paper, glass, cellulose acetate, cellulose nitrate, polyvinyl acecool, polypropylene, polyester films such as polyethylene terephthalate, and polystyrene. The type of photosensitive material can be selected as appropriate depending on the purpose of use of each photographic material.

These supports are subjected to undercoat processing if necessary.

After exposure, the photographic material containing the core/shell type silver halide emulsion according to the present invention can be developed by a commonly used known method.

The black and white developer is an alkaline solution containing developing agents such as hydroxybenzenes, aminophenols, and aminobenzenes, and other alkali metal salts such as sulfites, carbonates,
May include bisulfites, bromides, iodides, and the like. Further, when the photographic light-sensitive material is for color use, color development can be carried out by a commonly used color development method. In the reversal method, the image is first developed with a black-and-white negative developer, then exposed to white light or treated with a bath containing a fogging agent, and then color developed with an alkaline developer containing a color developing agent. There are no particular restrictions on the processing method, and any processing method can be applied, but typical examples include a method in which a bleach-fixing process is performed after color development, followed by washing with water and stabilization treatment if necessary, or a method in which color development is performed. rear,
Bleaching and fixing are carried out separately, and if necessary, washing with water,
A method of performing stabilization processing can be applied.

Color developing solutions generally consist of an alkaline aqueous solution containing a color developing agent. The color developing agent is a known primary aromatic amine developer, such as phenylene diamines (e.g. 4-amino-N, N-diethylaniline, 3-methyl-4-amino-N, N-diethylaniline, 4-7-mi/ -N-
Nij-ru N-β-hydroxyethylaniline, 3-
Methyl-4-amino-N-ethyl-N-β-hydroxyethylaniline, 3-methyl-4-amino-N-ethyl-N-β-methanesulfamidoethylaniline, 4-amino-3-methyl-N- ethyl-N-β-methoxyethylaniline, etc.) can be used.

In addition, L.F.A.Mason (L, F, A.

Photographic Processing Chemistry (Photographic Processing Chemistry)
ing Chemistry).

(Published by Focal Press,
1966), pp. 226-229, U.S. Pat. No. 2,193.
, No. 015, No. 21592.364, Japanese Unexamined Patent Publication No. 1973-6
Those described in No. 4933 and the like may be used.

The color developing solution may also contain a pH buffer, a development inhibitor or an antifoggant.

In addition, water softeners, preservatives, organic solvents, development accelerators, dye-forming couplers, competitive couplers, fogging agents, auxiliary developers, viscosity-imparting agents, polycarboxylic acid chelating agents, and antioxidants are added as necessary. It may also include.

After color development, the photographic emulsion layer is usually bleached. The bleaching process may be performed simultaneously with the fixing process, or may be performed separately. As bleaching agents, compounds of polyvalent metals such as iron (U), cobalt (JT), chromium (Vl), and copper (It), peracids, quinones, and nitroso compounds are used.

U.S. Patent No. 3,042,52 is used for bleaching or bleach-fixing solutions.
No. 0, No. 3,241,966, Special Publication No. 45-8506
Bleaching accelerators described in Japanese Patent Publication No. 45-8836, etc.
In addition to the thiol compounds described in JP-A No. 53-65732, various additives may also be added.

The photosensitive material according to the present invention can be used not only for photographic film but also for photographic paper.

E, Example Specific examples of the present invention will be described below.

In all the examples below, the amount added in the silver halide color photographic material is shown per 1 d.
In addition, silver halide and colloidal silver are shown in terms of silver.

<Example 1> (1) Preparation of silver halide emulsion First, silver halide seed particles and gelatin aqueous solution were placed in a reaction vessel, and while controlling the pAg and pH in the reaction vessel, ammoniacal silver nitrate was added. An aqueous solution, an aqueous potassium bromide solution (1), and an aqueous potassium bromide solution (2-1) or an aqueous potassium bromide solution (2-2), which has a lower potassium iodide content than the solution (1), are mixed into particles. Add in proportion to the increase in surface area during growth, and add solution (1) at an appropriate particle size.
The ratio of solution (2-1) or solution (2-2) to the solution was increased and the addition was continued. In some cases, the addition ratio of solution (2-1) or solution (2-2) to solution (1) was increased in two stages. Next, Demol N aqueous solution manufactured by Kao Atlas Co., Ltd. and magnesium sulfate aqueous solution were added to perform precipitation desalting, and gelatin was added to pA.
g7.8. I) An emulsion of H6,0 was obtained.

Furthermore, sodium thiosulfate, chloroauric acid, and ammonium rhodanate were added to perform chemical ripening, resulting in 4-hydroxy-
6-methyl-1,3,3a,? -tetrazaindene and 6
- Nitropenzimidazole was added, and gelatin was further added to obtain a core/shell type silver iodobromide emulsion.

Here, solution (1) and solution (2-1) or solution (2-
By changing the addition ratio of 2), the silver iodide mol% is changed, and by changing the addition amounts of ammoniacal silver nitrate and potassium nitrate, the grain size is changed, and the solution ( 1) and solution (2-1)
Alternatively, by changing the particle diameter when changing the addition ratio of solution (2-2), the outermost shell thickness and middle shell thickness are changed, and furthermore, by changing the pAg during the reaction, the crystal habit is changed, Core/shell type silver iodobromide emulsion samples EM-1-1 to EM-11-2 as shown in Table 1 were prepared.

Each emulsion sample shown in Table 1 was found to be a monodisperse emulsion having the average grain size and coefficient of variation of grain size distribution shown in the table by electron microscopic observation.

(The following margins are continued on the next page.) <Example 2> RL-1, RH-1, IL, and GL-1 shown below in order from the support (BS) coated with the Halley silane prevention layer upwards
, GH-1, YF, BL-1, BH-1, and Pro were laminated.

Low-sensitivity layer of red-sensitive silver halide emulsion layer (RL-emulsion EMI-1 shown in Example 1 color-sensitized to red sensitivity 1.
8 g and 0.2 g of 1-hydroxy-4-(isopropylcarbamoylmethoxy)-N-(δ-(2,4-di-
t-amylphenoxy)butyl] = 2-naphthamide (
C-1), 0.07 g of 1-hydroxy-4-(
4-(l-hydroxy-8=acetamido-3,6-disulfo-2-naphthylazo)phenoxy)-N-Cδ-
(2,4-di-t-amylphenoxy)butyl2-
Naphthamide disodium (referred to as CC-1), 0.
8 g of 1-hydroxy-2-[δ-(2,4-di-t-
amylphenoxy)-n-butyl]naphthamide (C-
2) and Oj) Ig DIR compound (D-1) dissolved in 0.5 g of tricresyl phosphate (TCP) and emulsified and dispersed in an aqueous solution containing 1.85 g of gelatin. A low-speed layer of a red-sensitive silver halide emulsion layer containing .

High-sensitivity layer of red-sensitive silver halide emulsion layer (RH - emulsion EM-1-2 shown in Example 1 sensitized to red sensitivity)
og, 0.20 g of cyan coupler (C-1),
A red-sensitive halogenated compound containing a dispersion in which 0.03 g of colored cyan coupler (CC-1) was dissolved in 0.23 g of TCP and emulsified and dispersed in an aqueous solution containing 1.2 g of gelatin. High sensitivity layer of silver emulsion layer.

Low-sensitivity layer of green-sensitive silver halide emulsion layer (GL-emulsion 1
1.5g of -1 color sensitized to green sensitivity and 0.65g
1-(2,4,6-1-lichlorophenyl)-3-(
3-(p-dodecyloxybenzenesulfonamide)benzamide to 5-pyrazolone (referred to as M-1), 0.
15 g of 1-(2,4,6-)lichlorophenyl)-
4-(1-naphthylazo)-3-(2-chloro-5-octadecenylsuccinimidoanilino)-5-pyrazolone (referred to as CM-1), 0.03 g of DIR compound (D-1) was dissolved. 0.68g TCP to 1.4g
A low-sensitivity layer of a green-sensitive silver halide emulsion layer containing a dispersion emulsified and dispersed in an aqueous solution containing gelatin.

High-sensitivity layer of green-sensitive silver halide emulsion layer (GH-emulsion 1
-2, 0g of emulsion sensitized to green sensitivity, and 0.22
g of magenta coupler (M-1) and 0.045 g of colored magenta coupler (CM-1) were dissolved.
A high-sensitivity layer of a green-sensitive silver halide emulsion layer containing a dispersion in which 27 g of TCP was emulsified and dispersed in an aqueous solution containing 1.9 g of gelatin.

Low-sensitivity layer of blue-sensitive silver halide emulsion layer (BL-emulsion 1
0.88g and 1.2g of -1 color sensitized to blue sensitivity
α-pivaloyl-α-(1-benzyl-2-phenyl-3,5-dioxysoimidazolidin-4-yl)-2
-chloro-5-[α-dodecyloxycarbonyl)ethoxycarbonyl]acedoanilide (referred to as Y-1),
0,6 in which 0.01g of DIR compound (D-1) was dissolved
A low-speed layer of a blue-sensitive silver halide emulsion layer containing a dispersion in which 8 g of TCP was emulsified and dispersed in an aqueous solution containing gelatin.

High-sensitivity layer of blue-sensitive silver halide emulsion layer (BH-emulsion E
A blue-sensitive emulsion containing 0.7 g of an emulsion color-sensitized to blue sensitivity of M-1-2 and a dispersion of 0.35 g of TCP in which a yellow coupler is dissolved in an aqueous solution containing gelatin. A highly sensitive silver halide emulsion layer.

Intermediate layer (IL) 0.8 g gelatin and 0.07 g 2,5-di-t
- an intermediate layer containing 0.07 g of dibutyl phthalate (referred to as DBP), which is a hexalysis of octylhydroquinone (referred to as HQ-1);

Yellow filter (YF) 0.15 g of yellow colloidal silver, 0.2 g of color stain inhibitor (HQ-1) dissolved in O, 1 g of DBP, 1
．． One layer of yellow filter containing 0g gelatin.

Protective layer (Pro) 2.3g gelatin protective layer.

DIR compound R21 Regarding sample wind 1 prepared in this way, GL-1, GH
The silver halide grains contained in -1 were replaced with those listed in coating-1, and the amount of gelatin and silver halide emulsion contained in GL-1 and GH-1 were changed to change the amount of silver halide in each layer and dry Set the film thickness and silver density to the values shown in Table 2, and write the values in Table 2. Samples NaA-1 to A-19 shown in 2A were obtained. Also, BL-1
, BH-1 were similarly subjected to the above operations to obtain samples B-1 to B-19 shown in Table 2B.

Further, the silver halide grains according to the present invention are composed of a green-sensitive layer composed of a single layer or a plurality of layers having the silver density and dry film thickness according to the present invention, and composed of a single layer or several layers. It may be used in at least one of the blue-sensitive layers.

Each sample was subjected to conventional wedge exposure for measurements of sensitometric performance (sensitivity, exposure range, fog) and graininess, and square wave frequency wedge exposure for sharpness measurements, followed by subsequent processing. processed in the process.

Processing steps: Color development 3 minutes 15 seconds Bleaching 6 minutes 30 seconds Washing 3 minutes 15 seconds
Arrive: Wash for 6 minutes and 30 seconds
Stabilized for 3 minutes 15 seconds 1 minute 3
0 second drying The composition of the treatment liquid used in each treatment step is shown below.

[Color developer]

4-Amino-3-methyl-N-(β-hydroxyethyl)-aniline sulfate 4.57g Anhydrous sodium sulfite 4.25g Hydroxylamine pseudosulfate 2.0g Anhydrous potassium carbonate
37.5 g sodium bromide
Add 1.3g nitrilotriacetic acid trisodium salt (monohydrate) 2.5g potassium hydroxide 1.0g water to prepare IE.

[Brewing liquid]

Ethylenediaminetetraacetic acid iron ammonium salt 100.
0 g Ethylenediaminetetra vinegar #I! 2 ammonium salt 10
．． 0 g Ammonium bromide 150.0 g
Add 10.0ml of glacial acetic acid water to make IJ, and adjust to pH 6.0I using ammonia water.
C Adjust.

[Fixer]

Ammonium thiosulfate 175.0 g
Anhydrous ammonium sulfite 8.6g Sodium metasulfite 2.3g Add water to 1
1 and adjust the pH to 6.0 using acetic acid.

[Stabilizing liquid]

Formalin (37% aqueous solution) 1.5 ml Conidax (manufactured by Konishiroku Photo Industry Co., Ltd.) 7.5 ml Add water to make 11.

The developed samples were subjected to sensitometric measurements, granularity measurements, and sharpness measurements using blue light, green light, and red light, respectively.

Sensitivity: The reciprocal of the exposure amount (true value) that gives an optical density of Turnip IJ +0.1 on the characteristic curve (in the table of results of Examples, the binary value expressed as a relative value with the sensitivity of the comparative emulsion as 100 is The larger the value, the faster the sensitivity, which is preferable.)

Sharpness: Detection of the improvement effect of image sharpness is performed using MTF (
Modulation Transfer Function
ion) and compared the MTF size of 10 fins/fin.

The larger the value, the better.

Graininess...RMS: Dye image density is Dmin +0.
The 1000 times value of the standard deviation of the density value variation that occurs when the dye image of No. 8 is scanned by a microdensitometer with a circular scanning aperture of 25 μm is expressed as a relative value with the control sample as 100. The higher the value, the coarser the grains, which is not preferable.

Width of exposure range: Exposure amount (log value) that gives an optical density of Cub IJ +0.1 on the characteristic curve and maximum optical density -0
, 1, the larger the difference between the exposure doses (logarithmic value), the wider the exposure range, which is preferable.

(The following margins continue on the next page.) From these results, it can be seen that all the results are improved when a core/shell type emulsion is used and the At concentration is set based on the present invention.

<Example 3> A sample was prepared in the same manner as in Example 2 except that the layer structure was reversed as follows.

From the bottom, BS→RL-1→IL-, GL-1→I
L-BL-1→IL→RH-1→IL→GH-In I
L-+B H-1-+Pro.

The results are shown in Tables 3A and 3B, and the results are good for all the examples based on the present invention.

(Margin below, continued on next page.)

Claims (1)

[Claims] 1. An inner core consisting essentially of silver bromide and/or silver iodobromide, and an inner core provided outside the inner core and consisting essentially of silver bromide and/or silver iodobromide. In the silver halide photographic material containing negative-working silver halide grains having a plurality of outer shells, the iodine content of the outermost shell of the silver halide grain is 10 mol% or less, and the outermost shell An iodine-rich shell having an iodine content of 6 mol % or more higher than that of the outermost shell is provided inside the outermost shell, and the silver density (
d) is d=N/V [where, N is the total amount of silver (converted to metallic silver) in the silver halide emulsion layer (unit: g), V is the halo, and d ≧4.0×10^-^1g/cm
A silver halide photographic material that is ^3.