JPH06301129A - Medium-aspect-ratio platelike grain emulsion - Google Patents

Abstract

PURPOSE: To obtain an emulsion having both the known advantages of tabular grain due to their unique deformed shape and those of a high chloride emulsion having essentially more stable crystal faces of tabular grain than [111] crystal faces. CONSTITUTION: This emulsion is a radiation sensitive emulsion contg. a dispersive medium and silver halide particles. At least 50% of the total projection area of all the particles is occupied by tabular grain each partitioned by [100] principal face having an adjacent edge ratio of <10, each having an aspect ratio of at least 2, having an average aspect ratio of <=8 and contg. iodide and at least 50mol% chloride practically in their nucleus forming parts.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to radiation-sensitive silver halide emulsions.

[0002]

2. Description of the Related Art In the 1980s, the sensitivity-granularity relationship was improved, at the absolute standard, and as a function of binder curing, the coating power was increased, the developability was faster, the temperature stability was increased, and the image sensitivity was increased. A wide range of photographic advantages, such as increased separation of inherent sensitivity and spectral sensitization and improved image sharpness in both single emulsion layer and multiple emulsion layer formats, were obtained by using tabular grain emulsions. Significant progress has been made in silver halide photography based on what it has found to be attainable.

The tabular grains account for at least 5 of the grain projected area.
At 0%, the emulsion is generally understood to be a "tabular grain emulsion". A grain is generally considered to be a tabular grain if the equivalent circular diameter (ECD) ratio of the grain to its thickness is at least 2. The equivalent circular diameter of a particle is the diameter of a circle having an area equal to the projected area of the particle. The term "medium aspect ratio tabular grain emulsion" refers to an emulsion having an average tabular grain aspect ratio in the range of 5-8. The term “thin tabular grain” is 0.2 μm
It is generally understood to be tabular grains with thinner thickness. The term "ultra-thin tabular grain" is 0.06 μm
Alternatively, it is generally understood to be a tabular grain having a smaller thickness. The term "high chloride" refers to particles containing at least 50 mol% chloride based on silver. For mixed halogen-containing particles, the halogens are named in order of increasing molarity. For example, silver iodochloride contains a higher concentration of chloride than iodide.

The overwhelming majority of tabular grain emulsions contain irregular octahedral tabular grain emulsions. Octahedral grains have eight identical crystal faces (each in a different {111} crystal face). The tabular irregular octahedron has two or more parallel twin planes that separate the two main grain faces in the {111} crystal face. The {111} major surface of the tabular grain has triple symmetry and shows a triangle or a hexagon. The tabular shape of the grains creates the preferred edge sites in silver halide deposition with the result of lateral grain growth (if necessary) with a slight increase in thickness after incorporation of parallel twin planes. It is generally accepted that it comes from twin planes.

Tabular grain emulsions have been used to advantage in a wide variety of photographic and radiographic applications, while the need for parallel twin plane formation and {111} crystal faces has led to emulsion preparation and It raises the issue of limiting both use. These drawbacks are most apparent when considering tabular grains containing significant chloride concentrations. It is generally accepted that silver chloride grains prefer to produce tetragonal cubic grains (ie the grains are separated by six identical {100} crystal faces). In silver chloride emulsions, tabular grains bounded by {111} planes often revert to nontabular shapes unless morphologically stabilized.

Tabular grain silver bromide emulsions have been available for a long time in 19
Wey, U.S. Pat. No. 4,399,215, known in the art in the eighties, produced the first tabular grain silver chloride emulsions. The tabular grains are {11
It was a twin type, showing a triple symmetrical main surface in the 1} crystal plane. The ammoniacal double-jet precipitation technique was used. The tabular grains were thicker than the silver bromide and silver bromoiodide tabular grain emulsions of the same era, as the ammonia ripening agent thickened the tabular grains. In order to achieve ammonia ripening, it was also necessary to precipitate the emulsion at a relatively high pH (known as minimum density enhancement (fog) in high chloride emulsions). Furthermore, both bromide and iodide ions were removed from the tabular grains early in their formation to prevent the desired tabular grain shape from collapsing.

US Pat. No. 4,414,306 to Wey et al.
The specification developed a twinning process for preparing silver chlorobromide emulsions containing up to 40 mol% chloride, based on total silver.
This method of preparation did not successfully extend high chloride emulsions. The highest average aspect ratio reported in the examples was 11. Maskasky US Patent No. 4,
No. 400,463 (hereinafter, Maskasky I
Precipitates high chloride emulsions containing tabular grains with parallel twin planes and {111} major crystal faces, which has the important advantage of allowing inclusion of substantially significant other halides. Developed the method. This method uses a specially selected synthetic polymer peptizer as its action {1
11} was to be used in combination with a grain growth modifier that promotes the formation of crystal planes. Adsorbed aminoazaindene (preferably adenine) and iodide ions have been disclosed as useful grain growth modifiers.

Maskasky US Pat. No. 4,71
No. 3,323 (hereinafter referred to as Maskasky II) describes an aminoazaindene growth modifier and a maximum of 3
A high chloride emulsion containing tabular grains having parallel twin planes and {111} major crystal faces was prepared by using a gelatin peptizer containing 0 μmol / g methionine. Advanced significantly. If the methionine content of the gelatin peptizer is undesirably high, it can be easily reduced by treatment with a strong oxidant (ie, alkylating agent, King et al., US Pat. No. 4,942,120). Because it can be done, Maskasky
II was within the reach of the art to place high chloride tabular grains encapsulating the key bromide and iodide ions prepared, including conventional, commonly available peptizers.

Maskasky I and II stimulated further studies of grain growth modifiers that allowed the preparation of high chloride emulsions of similar tabular grain content: di (hydroamino) as a grain growth modifier. Tafa with azine
No. et al., U.S. Pat. No. 4,804,621; Takada et al., U.S. Pat. No. 4,783,398, using heterocycles with divalent sulfur ring atoms; spectral sensitizing dyes and heterocycles; US Pat. No. 4,9, Nishikawa et al. Using a divalent sulfur atom containing an acyclic compound.
52,491; as well as US Pat. No. 4,983,5 to Ishiguro et al. Using organic bis quaternary amine salts.
No. 08 specification.

Bogg US Pat. No. 4,063,951
The specification first reported a tabular grain emulsion in which the tabular grains had parallel {100} major crystal faces. Bogg's tabular grains exhibited square or rectangular major faces (thus lacking the triple symmetry of conventional tabular grain {111} major crystal faces). In one example, Bogg is 4: 1 to 1:
The ammonia ripening method was used to prepare silver bromoiodide tabular grains having aspect ratios of 1. The highest aspect ratio grains (grain A in Figure 3) were only 4, and the average aspect ratio of this emulsion was reported to be 2. Bogg states that this emulsion can contain less than 1% iodide and describes only a 99.5% bromide 0.5% iodide emulsion. Attempts to prepare tabular grain emulsions by the Bogg procedure were unsuccessful.

Symposium: Turin 1963, C.I. Se
Photogra edited by merano and Mazzucato
Phic Science, Focal Press, pages 52-55, discloses ripening of cubic grain silver chloride emulsions at 77 ° C for several hours. During ripening tabular grains appear and the original cubic grains are depleted by Ostwald ripening. After 3 hours of ripening, the tabular grains accounted for only a small portion of the total grain projected area, with only a few tabular grains having a thickness of less than 0.3 μm, as illustrated by the Comparative Examples below. It was In a further study beyond the teaching provided in reality, extended aging removed a large number of smaller cubic grains, but
Also, many tabular grains were downgraded to thicker shapes.

[0012]

SUMMARY OF THE INVENTION In one aspect, the present invention is a radiation-sensitive emulsion comprising a dispersion medium and silver halide grains having a total grain projected area of at least 5 grains.
0% is bounded by {100} major faces with (1) adjacent edge ratios less than 10, and (2)
Each has an aspect ratio of at least 2, and together has an average aspect ratio of up to 8, and (3)
It is directed to emulsions which are characterized in that they are occupied by tabular grains containing iodide and at least 50 mol% chloride substantially at their nucleation sites.

[0013]

The present invention is based on the discovery of a new method for producing tabular grains. In lieu of introducing parallel twin planes into the grains, the selected pCl 2 is chosen so as to form parallel twin planes and produce tabularity, thereby producing tabular grains with {111} major faces. The presence of iodide during the high chloride nucleation step, which keeps the chloride ion of the solution within the range, results in the formation of a tabular grain emulsion in which the tabular grains are bounded by {100} crystal faces. I have found

In addition to practicing the present invention, which represents the discovery of a novel process for preparing tabular grain emulsions, the emulsions made by that process are also novel. The present invention places tabular grains bounded by {100} crystal faces with halide content, halide arrangement, and grain thicknesses not heretofore realized, within the reach of the art. The invention can provide selected photographic applications and can range from ultrathin tabular grains to thicknesses found in thicker tabular grains, sometimes referred to as slabular grains. . In one preferred form, the present invention provides intermediate aspect ratio tabular grain high chloride emulsions which exhibit high levels of grain stability. Unlike high chloride tabular grain emulsions in which the tabular grains have {111} major faces, the emulsions of this invention incorporate a morphological stabilizer that is adsorbed on the major faces of the grains and maintains its tabular shape. do not need. Finally, while high chloride emulsions are applicable, the present invention extends high chloride emulsions beyond those containing a wide range of bromide, iodide and chloride concentrations.

Photographically useful radiation-sensitive emulsions of this invention comprise a dispersion medium and silver halide grains.
At least 50% of the total grain projected area is accounted for by tabular grains bounded by {100} major faces having an adjacent edge ratio of less than 10. Tabular grains having {100} major faces are also referred to hereinafter as {100} tabular grains. By definition, each {100} tabular grain exhibits an aspect ratio of at least 2. The {100} tabular grains contain an iodide and at least 50 mole percent chloride at an average aspect ratio of up to 8 and substantially at their nucleation sites.

Identification of emulsions satisfying the {100} tabular grain projected area and aspect ratio requirements of this invention can be made by analytical procedures well known in the art. For example, micrographs of shaded carbon grain replicas of representative emulsions of the present invention show that grains having {100} major faces are readily available from their orthogonal rectangular (square or rectangular) major faces and / or projected areas. Can be identified. Nontabular grains either lack parallel grain faces or lack parallel major faces (ie, faces are distinctly larger than the other faces of the grain). Tabular grains having {111} major faces exhibit triple symmetry. That is, the particles usually have a triangular or hexagonal principal surface and, in some cases, a polygonal or circular principal surface, but they do not exhibit orthogonal rectangular principal surfaces.

Among the particles having an orthogonal square surface (ie, {100} surface), a small amount of needle-shaped or rod-shaped particles (hereinafter referred to as rods) is observed. These particles are
The length in one direction is ten times longer than the length in the other direction and can be excluded from the desired tabular grain population based on its high edge length ratio. The projected area occupied by rod-shaped particles is small.

The determination, based on the ratio of adjacent edges, that the remaining grains having orthogonal rectangular faces, after eliminating the rod-shaped grains present, are tabular grains requires the measurement of grain thickness. From knowledge of the projection angle, it is possible to calculate the thickness by measuring the length of the shadow. {10
A tabular grain having a 0} major surface is a grain having a major surface having an orthogonal rectangular projected area or an aspect ratio of at least 2. Aspect ratio (ECD / t) is the ratio of the equivalent circular diameter (ECD) of a particle divided by its thickness (t). The ECD of a grain is the diameter of a circle that has the same projected area as the grain. A tabular grain that is bounded by {100} major faces with adjacent edge ratios less than 10 occupies at least 50% {100} of the total grain projected area and exhibits an average aspect ratio of up to 8. Invention requires {1
00} tabular grain projected areas and aspect ratios are satisfied. Emulsions according to the invention which are very useful for many photographic applications are those having an average aspect ratio in the intermediate range, i.e. 5-8.

Preferably, the {100} tabular grain population exhibits a major surface edge length ratio of less than 5, and optimally less than 2. The closer the principal face edge length ratio is to 1 (ie, equal to the edge length), the smaller the probability of rod populations being significantly present in the emulsion. In addition, tabular grains with smaller edge lengths are believed to be less sensitive to pressure desensitization.

The tabular grain population can exhibit any grain thickness compatible with the above average aspect ratios. Surprisingly, ultrathin tabular emulsions have been prepared which meet the requirements of the present invention. Ultra-thin tabular grain emulsion is {10
The 0} tabular grain population is composed of tabular grains having an average thickness of less than 0.06 μm. It was generally believed that it was essential to form tabular grains by the mechanism of parallel twin plane incorporation to achieve ultrathin dimensions. Parallel twin plane is {111}
Tabular grains having major faces are produced. Emulsions prepared as described herein can be prepared so that the tabular grain population has an average thickness of at least 0.02 μm, and even 0.01 μm. Ultrathin tabular grains have extremely high volume to surface ratios. This allows
Ultra-thin particles can facilitate photographic processing. Furthermore, when spectrally sensitized, the ultrathin grains show a much higher sensitivity ratio in the sensitized spectral region compared to the original spectral region of sensitivity. For example, the ultrathin tabular grain emulsions described herein have quite negligible blue sensitivity levels and, therefore, produce minimal blue contamination in photographic products when placed in a position to receive blue light. A green or red record can be provided to indicate.

In many photographic applications, {100} tabular grains accounting for at least 50 percent of total grain projected area are:
It is preferred to have a thickness of less than 0.3 μm and optimally less than 0.2 μm. It is recognized that limiting the tabular grain thickness also limits the average tabular grain ECD of the emulsion. Therefore, 0.3 μm or 0.2 μm
ECD of {100} tabular grains having a thickness of less than
Are less than 2.4 μm or 1.6 μm, respectively.

There are specific photographic applications that can benefit from a larger tabular grain thickness. For example, when forming a blue recording layer with the maximum achievable sensitivity, the average is 1 μm.
Or larger, but preferably up to 0.8 μm
In particular, a tabular grain thickness that can tolerate
This is because the eyes have little sensitivity to blue records, and therefore higher levels of image granularity (noise) can be tolerated without problems. There is an additional motivation to use larger particles in the blue record, which is that it is sometimes difficult to match the highest achievable sensitivity of the blue record to the green and red records. The source of this difficulty is the lack of blue photons in sunlight. Energy-based sunlight shows an equal proportion of blue, green, and red light, while at shorter wavelengths, photons have higher energy. Thus, for photons, the distribution based on daylight is slightly blue deficient.

Large tabular grain thickness (eg 0.5 μm)
> 100), the {100} tabular grain populations can exhibit average ECD's across the highest photographically useful grades. An average ECD of less than 10 μm is considered for photographic practicality, but for most photographic applications,
The average ECD rarely exceeds 6 μm. . As is generally understood by those skilled in the art, tabular grain emulsions with higher ECD are advantageous in achieving a relatively high level of photographic speed while at the same time having a smaller E
Tabular grain emulsions with CD are advantageous in achieving low levels of granularity.

The tabular grain population satisfying the parameters set forth herein is at least 5 of the grain population projected area.
As long as it occupies 0%, the desired particle population is available. The advantageous properties of the emulsions used in this invention are {10
It is observed that as the proportion of tabular grains having 0} major faces increases. Preferred emulsions have at least 70 percent, and optimally at least 90 percent of total grain projected area occupied by tabular grains having {100} major faces. When grain populations other than {100} tabular grains are rarely present in the emulsion, {100} tabular grain projected areas can approach 100% of total grain projected areas. If the tabular grains do not account for 50% of the total grain projected area, the emulsion does not meet the requirements of the invention and
It is generally a photographically inferior emulsion.

To the extent that tabular grains having the desired properties set forth herein account for the requisite proportion of grain population projected area, the balance of the grain population projected area will account for any combination of coprecipitated grains. Can also be occupied by.
Of course, it is conventional in the art to formulate emulsions to achieve particular photographic purposes. Formulated emulsions satisfying the tabular grain rating required by at least one component emulsion are clearly envisioned.

Obtaining an emulsion satisfying the requirements of the invention was achieved by discovering a new precipitation method. In this method, grain nucleation occurs in a high chloride environment where iodide ions are present under conditions that favor the appearance of {100} crystal faces. Grain formation results in the inclusion of iodide in the cubic lattice formed by silver ions, and because of the larger diameter of iodide ions compared to chloride ions, the remaining chloride ions collapse. . The incorporated iodide ions introduce crystal irregularities which, in further grain growth, give rise to tabular grains rather than regular (cubic) grains.

Incorporation of iodide ions into the crystal structure at the beginning of nucleation results in one or more cubic planes,
It is believed to produce cubic grain nuclei that are formed with growth that promotes one or more crystal lattice irregularities. A cubic plane containing at least one crystal lattice disorder, then
It accepts silver halide in a promoted proportion as compared to the regular cubic crystal plane (ie lacking the crystal lattice disorder). If only one of the cubic faces has a crystal lattice disorder, grain growth on only one face is promoted and the grain structure resulting from continued growth is the rod. The same result occurs when only two facing parallel faces of the cubic structure have crystal lattice irregularities. But,
If either of two adjacent cubic faces has a crystal lattice disorder, continued growth promotes growth of both faces and produces a tabular grain structure. It is believed that the tabular grains of the emulsions of this invention are formed by these grain nuclei having 2, 3 or 4 faces with growth promoting crystal lattice disorder. Initially, the growth-promoting crystal lattice disorder was believed to be a screw transition, but more recently questions have been raised regarding this explanation.

At the beginning of precipitation, the reaction vessel is provided with a dispersion medium and conventional silver as well as associated electrodes for monitoring halide ion concentration in the dispersion medium. A halide ion that is at least 50 mol% chloride is introduced into the dispersion medium (ie, at least half of the halide ions in the dispersion medium are chloride ions). The pCl of the dispersion medium is adjusted to facilitate the production of {100} grain faces during nucleation. That is, within the range of 0.5-3.5, preferably 1.0-3.0, and optimally 1.5-
It is within the range of 2.5.

The grain nucleation process begins when the silver jet is opened to introduce silver ions into the dispersion medium. Preferably the iodide ions are simultaneously together or,
Optimally, it is introduced into the dispersion medium before opening the silver jet. Effective tabular grain formation can occur over a range of iodide ion concentrations up to the saturation limit of iodide in silver chloride. The saturation limit of iodide in silver chloride is H.I.
Hirsch's "Photographic Emulsion Grains with C"
ores: Part I Evidence for the Presence of Cores ",
J. of Photog. Science, vol. 10 (1962), pages 129-134, it is reported to be 13 mol%. For silver halide grains in which equimolar proportions of chloride and bromide are present, up to 27 mole percent iodide, based on silver, can be incorporated into the grain. In order to avoid precipitation of a separate silver iodide phase, it is preferable to perform grain nucleation and grain growth below the iodide saturation limit, thereby avoiding the formation of additional undesirable categories of grains. It is generally preferred to keep the iodide ion concentration in the dispersion medium below 10 mol% at the beginning of nucleation. In fact
With nucleation, only small amounts of iodide are needed to achieve the desired tabular grain population. At least 0.00
Initial iodide ion concentrations up to 1 mol% are contemplated.
However, for convenience of reproducibility of results, an initial iodide concentration of at least 0.01 mol% is preferred, and optimally at least 0.05 mol%.

In the preferred method, silver iodochloride grain nuclei are formed during the nucleation step. A small amount of bromide ion can be present in the dispersion medium during nucleation. Any amount of bromide ion compatible with at least 50 mole% halide in the grain nuclei in which chloride ion is present can be present in the dispersing medium during nucleation. The grain nuclei preferably comprise at least 70 mol% and optimally at least 90 mol% chloride ions, based on silver.

Grain nucleation occurs immediately upon introduction of silver ions into the dispersing medium. For operational convenience and reproducibility, silver ion introduction during the nucleation step is preferably
It is extended for a convenient period, typically 5 seconds to less than 1 minute. It is not necessary to add additional chloride ions to the dispersion medium during the nucleation step as long as the pCl remains within the above range. However, it is preferred to introduce both the silver salt and the halide salt simultaneously during the nucleation step. The advantage of adding the halide salt along with the silver salt throughout the nucleation process ensures that the grain nuclei formed after the initial silver ion addition have essentially the same chloride content as the grain nuclei initially formed. That is what you can do. Addition of iodide ions during the nucleation step is particularly preferred. The iodide ion deposition rate far exceeds that of other halides, so iodide is consumed in the dispersion medium unless replenished.

During the nucleation process, any convenient conventional source of silver and chloride ions can be used. The silver ion is preferably an aqueous silver ion solution (for example,
(A silver nitrate solution). Chloride ions are preferably introduced as alkali or alkaline earth chlorides (eg lithium, sodium and / or potassium chloride bromide and / or iodide).

It is possible, but not preferred, to introduce silver chloride or silver iodochloride Lippmann grains into the dispersing medium during the nucleation step. In this case, grain nucleation has already occurred, and the nucleation step already referred to in this specification is actually a step for introducing crystal lattice disorder in the grain plane. The advantage of delaying the grain face crystal lattice disorder introduction process is that it produces thicker tabular grains than would otherwise be obtained.

The dispersion medium contained in the reaction vessel prior to the nucleation step comprises water, the dissolved halide ions previously discussed, and the peptizer. The dispersion medium can exhibit a pH within the usual range that is convenient for silver halide precipitation, typically 2-8. It is preferred, but not necessary, to maintain the dispersion medium on the neutral acid side (ie, below pH 7.0). The preferred pH range for precipitation is 2. to minimize fog.
It is 0 to 5.0. Using a mineral acid such as nitric acid or hydrochloric acid, and a base such as alkali hydroxide,
H can be adjusted. It is also possible to incorporate a pH buffer.

The peptizer is a silver halide emulsion for photography,
In particular, any convenient conventional form known to be useful for precipitating tabular grain silver halide emulsions can be employed. See Research Discl for an overview of peptizers.
osure, Vol. 308, December 1989, Section IX. Research Disclosure is Kenneth Mason
Publication Ltd., Emsworth, Hampshire PO10 7DQ, E
Published by ngland. Maskas already quoted
Synthetic polymeric peptizers of the type disclosed by ky I (which are hereby incorporated by reference) may be used, while gelatinous peptizers (eg, gelatin and gelatin derivatives) may be used. It is preferably used. The use of deionized gelatinous peptizers is a well-known practice, as gelatinous peptizers produced and used in the field of photography typically contain significant concentrations of calcium ions. In the latter case, the removed calcium ions are supplemented by the addition of divalent or trivalent metal ions such as alkaline earth or alkaline earth metals (preferably magnesium, calcium, barium or aluminum ions). It is preferable. Particularly preferred peptizers are low methionine gelatinous peptizers (ie containing less than 30 micromoles of methionine per gram of peptizer), optimally less than 12 micromoles per gram of peptizer. belongs to. These peptizers and their preparation are disclosed in the previously cited patent specifications of Maskasky II and King et al. (Herein incorporated by reference). But Maskasky I and Maskasky II
It should be noted that grain growth modifiers of the type taught for inclusion in emulsions (e.g., adenine) are not suitable for inclusion in dispersion media. This is because these grain growth modifiers promote twinning and formation of tabular grains having {111} major faces. Generally, at least about 10% and typically 20% of the dispersion medium that produces the finished emulsion.
~ 80% is present in the reaction vessel at the beginning of the nucleation step. It is common practice to maintain a relatively low level of peptizer, typically 10-20% of the finished emulsion, in the reaction vessel at the beginning of precipitation. In order to increase the proportion of thin tabular grains with {100} faces that are formed during nucleation, at the beginning of the nucleation step, the concentration of the peptizing agent in the dispersion medium is 0. It is preferably in the range of 5 to 6% by weight. It is common practice to add gelatin, gelatin derivatives and other vehicles as well as vehicle extenders to prepare emulsions for post-precipitation coating. Natural levels of methionine can be present in the added gelatin and gelatin derivatives after the precipitation is complete.

The nucleation step can be carried out at any convenient conventional temperature for precipitation of silver halide emulsions. Temperatures near room temperature (eg, 30 ° C to about 9 ° C)
0 ° C) is considered, and the nucleation temperature is from 35 ° C to
Temperatures in the range of 70 ° C are preferred. Since grain nucleation occurs almost instantaneously, only a small fraction of the total silver introduced into the reaction vessel is needed during the nucleation process. Typically, about 0.1-10 mol% of the total silver is introduced during the nucleation process.

The nucleation step is followed by a grain growth step in which the grain nuclei grow until tabular grains having {100} major faces of the desired average ECD are obtained. The purpose of the nucleation step is to form a population of particles with the desired incorporated crystallographic disorder, whereas the purpose of the growth step is to avoid or minimize the formation of additional particles. , Depositing (growing) additional silver halide to existing grain populations. If additional grains are formed during the growth step, the polydispersity of the emulsion is increased and if the conditions in the reaction vessel are not maintained as described above during the nucleation step, the additional grains formed during the growth step are formed. Of the above-mentioned grain populations will not have the desired tabular grain characteristics described above.

In its simplest form, the emulsion preparation method according to the invention can be carried out as a single jet precipitation from start to finish without interruption of the introduction of silver ions. As is generally recognized by those skilled in the art, the spontaneous transition from particle formation to particle growth is
It also occurs at a uniform rate of silver ion introduction. This is because the size of the grain nuclei increases until they reach the point of accepting silver and halide ions at a rate that is fast enough that new grains cannot form, so that the grain nuclei are removed from the dispersion medium by silver and halogen. This is because it increases the rate at which the compound ions can be accepted. Although easy to operate, single jet precipitation limits halide content and profile and generally results in a more polydisperse grain population.

Since a higher percentage of the particle population can be optimally sensitized or optimally prepared for photographic use,
It is usually preferred to prepare photographic emulsions with the most geometrically uniform grain populations achievable. Furthermore, it is usually more convenient to formulate a relatively monodisperse emulsion to obtain the desired sensitometric profile than to precipitate a single polydisperse emulsion that matches the desired profile.

In the preparation of emulsions according to the invention, it is possible to interrupt the introduction of silver and halide salts at the end of the nucleation step and before starting the growth step which brings the desired final size and shape to the emulsion. preferable. The emulsion is held within the temperature range described herein for nucleation for a period sufficient to reduce grain dispersity. Retention times can range from 1 minute to several hours, with typical retention times ranging from 5 minutes to 1 hour. During the retention period, the relatively smaller particles age Ostwald over the remaining relatively larger particle nuclei, with the overall result that the particle dispersity is reduced.

If desired, during the holding period the ripening rate can be increased by the presence of ripening agents in the emulsion. The usual simple way to accelerate ripening is to increase the halide ion concentration of the dispersion medium. This creates a silver ion complex with multiple halide ions that promote ripening. When using this method, it is preferable to increase the chloride ion in the dispersion medium. That is, it is preferable to lower the pCl of the dispersion medium within the range in which the increased dissolution of silver halide is observed. Alternatively, ripening can be accelerated and the proportion of projected area of the grain population occupied by {100} tabular grains can be increased by using conventional ripening agents. Preferred ripening agents are sulfur-containing ripening agents such as thioethers and thiocyanates. Typical thiocyanate ripening agents are described in Nietz et al., US Pat. No. 2,222,264.
No. 2,448,53 to Lowe et al.
No. 4, and Illingsworth, U.S. Pat. No. 3,320,069 (hereby incorporated by reference). Typical thioether ripening agents are McBride, U.S. Pat. No. 3,271,157, Jones, U.S. Pat. No. 3,574,628 and Rosencra.
ntz et al., U.S. Pat. No. 3,737,313, which is hereby incorporated by reference. Recently crown thioethers have been proposed for use as ripening agents. Aging agents with primary or secondary amino components such as imidazole, glycine or substituted derivatives are also effective. Sodium sulfite has also been demonstrated to be effective in increasing the percentage of total grain projected area occupied by {100} tabular grains.

Once the desired population of grain nuclei has been formed, the emulsion of this invention is prepared according to any convenient conventional precipitation technique which precipitates silver halide grains bounded by {100} grain faces. Grain growth to obtain begins. It is necessary that the iodide and chloride ions be incorporated into the grains during nucleation, so that the iodide and chloride ions are present in the finished grains substantially at the nucleation sites, but the cubic crystal Halides or combinations of halides known to form a lattice structure can be used during the growth process. Irregular grain nuclei that cause tabular grain growth once introduced persist during the next grain growth regardless of halide precipitation, so iodide and chloride ions are incorporated into the grains during the growth process. It is not necessary that the given halide or combination of halides form a cubic lattice. This means that 13 mol% of the precipitated silver iodochloride (preferably 6 mol%)
Mol%), iodide levels above 40 mol% (preferably 30 mol%) of the precipitated silver iodobromide, and precipitated silver iodohalide containing bromide and chloride. Exclude only intermediate levels of iodide. When silver bromide or silver iodobromide is attached during the growth step, it is in the range of 1.0 to 4.2, preferably 1.6 to 4.2.
It is preferable to maintain pBr in the dispersion medium in the range of 3.4. When silver chloride, silver iodochloride, silver bromochloride or silver iodobromochloride is deposited during the growth step, it is preferred to maintain pCl in the dispersion medium within the ranges already mentioned in the nucleation step described.

It was quite an unexpected finding that reductions in tabular grain thickness of up to 20% can be achieved by introducing specific halides during grain growth. Surprisingly, addition of bromide in the range of 0.05 to 15 mol%, preferably 1 to 10 mol%, based on silver during grain growth is more than achieved under the same conditions precipitation without bromide ions. Is relatively thinner {1
00} was observed to produce tabular grains. Similarly, addition of iodide in the range of 0.001 to less than 1 mol% based on silver during grain growth is relatively thinner than that achieved for precipitation under the same conditions without iodide ions. It was observed to produce {100} tabular grains.

Both silver and halide salts are preferably introduced into the dispersing medium during the growth process. In other words, double jet precipitation is contemplated, with the addition of iodide salt introduced with the remaining halide salt or through a separate jet if necessary. The rates of introducing silver and halide salts are controlled to avoid re-nucleation (ie formation of new grain populations). The addition rate control to avoid re-nucleation is Wilgus
German Patent Publication No. 2,107,118, Ir
IE, U.S. Pat. No. 3,650,757, Kur.
U.S. Pat. No. 3,672,900 to Z. Sait
o U.S. Pat. No. 4,242,445, Teit
European patent application 80102242 to Schied et al. and Wey's "Growth Mechanism of AgBr Crys".
tals in Gelatin Solution ", Photographic Science an
d Engineering, Vol. 21, No. 1, January 1977,
It is generally well known in the art, as described on page 14.

In the simplest form of the invention, the nucleation and growth stages of particle precipitation occur in the same reaction vessel.
However, it is recognized that grain precipitation can be interrupted, especially after the end of the nucleation step. Furthermore, two separate reaction vessels can be replaced by the single reaction vessel described above. The nucleation step of particle precipitation can be carried out in an upstream reaction vessel (referred to herein as a nucleation reaction vessel) and the dispersed particle nuclei are transferred to a downstream reaction vessel (wherein the growth step of particle precipitation occurs). Call the growth reaction vessel). US Pat. No. 3,79 to Pose et al.
0,386, Forster et al., U.S. Pat. No. 3,897,935, Finnicum et al., U.S. Pat. No. 4,147,551, and Verh.
One arrangement of this type uses a closed nucleation vessel, as described in U.S. Pat. No. 4,171,224 to Ille et al., which is hereby incorporated by reference. , Can receive the reactant upstream of the growth reaction vessel and agitate. In these arrangements, the contents of the growth reaction vessel are recycled to the nucleation reaction vessel. p
It is contemplated herein that various important parameters controlling particle formation and growth, such as H, pAg, aging, temperature, and residence time, are independently controlled in separate nucleation and growth reaction vessels. To be In order to make the grain nucleation completely independent of the grain growth occurring in the growth reaction vessel downflow of the nucleation reaction vessel, it is better not to recycle the contents of the growth reaction vessel to the nucleation reaction vessel at all. A preferred arrangement for separating particle nucleation from the contents of a growth reaction vessel is Mignot US Pat. No. 4,334,334.
012 (which also discloses useful aspects of ultrafiltration during particle growth), Urabe, US Pat.
No. 879,208, and published European patent applications Nos. 326852, 326852 and 35553.
5 and 370116, Ichizo, published European Patent Application No. 368275, Ur.
Published European Patent Application No. 374954 of Abe et al. and Japanese Patent Application Laid-Open No. 2-172817 (19) of Onishi et al.
90).

The emulsions of the present invention can include silver iodochloride emulsions, silver iodobromochloride emulsions and silver iodochlorobromide emulsions.
The dopant can be present in the grain at a concentration of up to 10 ^-2 mol per mol of silver, typically less than 10 ^-4 mol per mol of silver. Metal compounds such as copper, thallium, lead, mercury, bismuth, zinc, cadmium, rhenium, and Group VIII metals (eg iron, ruthenium, rhodium, palladium, osmium, iridium and platinum) are preferred during particle precipitation. Can be present during the growth stage of precipitation.
The improvement in photographic properties is related to the level and location of the dopant within the grain. When the metal forms part of a coordination complex, such as a hexa coordination complex or a tetra coordination complex,
Ligands can also be included within the grain and, in addition, the ligand can affect photographic properties.
Halo, aquo, cyano, cyanate, thiocyanate,
Ligands such as nitrosyl, thionitrosyl, oxo and carbonyl ligands are contemplated and can be relied upon to improve photographic properties.

The dopants and their additions are Arn
US Pat. No. 1,195,432 to Old et al., H
ochsetter US Pat. No. 1,951,933
U.S. Pat. No. 2,628,1 to Overman.
67, Mueller et al., U.S. Pat.
0,972, McBride U.S. Pat.
287,136, Sidebotham U.S. Pat. No. 3,488,709, Rosetran.
ts et al., U.S. Pat. No. 3,737,313, Sp.
U.S. Pat. No. 3,687,676 to Ence et al.,
Gilman et al., U.S. Pat. No. 3,761,267, Shiba et al., U.S. Pat. No. 3,790,390, Ohkubo et al., U.S. Pat. No. 3,890,154.
No. 3,901,7 to Iwaosa et al.
11, U.S. Pat. No. 4,173,4 to Habu et al.
83, Atwell U.S. Pat. No. 4,269,
927, Janusonis et al., U.S. Pat. No. 4,835,093, McDugle et al., U.S. Pat. Nos. 4,933,272, 4,981,781.
No. 5,037,732, Keeve
rt et al., U.S. Pat. No. 4,945,035, and Evans et al., U.S. Pat. No. 5,024,931 (incorporated herein by reference). For background on known alternatives in the field of interest, see B. H. Carroll's "Iridium
Sensitization: A Literature Review ", Photographic
Scienceand Engineering, Vol. 24, No. 6, 1980 11 /
December, pp. 265-257, suggested in published European patent application No. 264288 to Grzeskowiak et al.

Conventional high chloride tabular grain emulsions having tabular grains bounded by {111} are inherently unstable and a morphological stabilizer to prevent the grains from reverting to their nontabular morphology. The present invention is advantageous in providing high chloride (higher than 50 mole% chloride) tabular grain emulsions because of the presence of Highly preferred, high chloride emulsions are higher than 70 mol% according to the invention (optimally 90%).
Higher than mol%) chloride.

Although not essential to the practice of the present invention, {10
An additional treatment that can be used to maximize the population of tabular grains having 0} major faces is to incorporate agents that can suppress the appearance of non- {100} grain crystal faces of the emulsion during emulsion preparation. is there. If an inhibitor is used, it can be activated during grain formation, growth or throughout precipitation.

Under the contemplated precipitation conditions, useful inhibitors are organic compounds containing a nitrogen atom with a resonance stabilized p electron pair. Resonance stabilization prevents protonation of the nitrogen atom under the relative acid conditions of precipitation. Aromatic resonance can rely on the stability of the π electron pair of the nitrogen atom. The nitrogen atom can be incorporated into the aromatic ring, such as an azole or azine ring, or can be a ring substituent on the aromatic ring.

In one preferred form, the inhibitor may satisfy the following formula (I): (I)

[0052]

[Chemical 1]

Wherein Z represents an atom necessary to complete a 5- or 6-membered aromatic ring structure, and is preferably formed by carbon and nitrogen ring atoms.
Aromatic rings are those with 1, 2 or 3 nitrogen atoms. Particularly contemplated ring structures are 2H-pyrrole, pyrrole, imidazole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, 1,3,5-triazole, pyridine, pyrazine, pyrimidine, and pyridazine. Include.

When the stabilized nitrogen atom is a ring substituent, preferred compounds satisfy the formula (II): (II)

[0055]

[Chemical 2]

Wherein Ar is an aromatic ring structure having 5 to 14 carbon atoms, and R ¹ and R ² are each independently hydrogen, Ar or a convenient aliphatic group, or , Together to complete a 5- or 6-member ring.)
Ar is preferably a cyclic carboaromatic ring such as phenyl or naphthyl. Alternatively, any nitrogen and carbon bearing the above aromatic ring can be attached to the nitrogen atom of formula II via a ring carbon atom. In this case, the resulting compound satisfies both formula I and II. Any of a wide variety of aliphatic groups can be selected. The most easily considered aliphatic groups are alkyl groups, preferably 1 to
It has 10 carbon atoms, most preferably 1 to 6 carbon atoms. Functional substituents on any of the alkyl groups known to be compatible with silver halide precipitation can be present. It is also conceivable to use cycloaliphatic substituents exhibiting a 5- or 6-membered ring such as cycloalkanes, cycloalkenes and aliphatic heterocycles such as those having oxygen and / or nitrogen heteroatoms. Cyclopentyl, cyclohexyl, pyrrolidinyl, piperidinyl, furanyl and similar heterocycles are especially contemplated.

The following are Formula I and / or Formula I
Representative compounds believed to satisfy I:

R-1

[Chemical 3]

[0059]

[Chemical 4]

[0060]

[Chemical 5]

[0061]

[Chemical 6]

[0062]

[Chemical 7]

[0063]

[Chemical 8]

[0064]

[Chemical 9]

The selection of preferred inhibitors and their effective concentrations can be carried out by the following selection procedure: The compounds considered for use as inhibitors are selected from essentially cubic grains with a mean grain edge length of 0.3 μm. It is added to the silver chloride emulsion. This emulsion is 0.2 in sodium acetate.
Molar, pCl is 2.1, a pH that is at least 1 unit greater than the pKa of the compound considered. The emulsion is held with the inhibitor for 24 hours at 75 ° C. Two
When the cubic grains have a square edge of {100} crystal faces than the control, which differs only in the absence of a possible compound, after 4 hours of microscopic examination, the incorporated compound acts as an inhibitor. There is. The angular crossing edge of the {100} crystal plane is the fact that the particle edge is the most active site on the particle due to the ions re-entering the dispersion medium. By maintaining sharp edges, the suppressor acts, for example, at rounded edges and corners to suppress the appearance of non- {100} grain crystal faces. In some cases, replacing the dissolved silver chloride that adheres exclusively on the edges of the cubic grains, {1
A new particle population is formed, which is bounded by the {00} crystal planes. Optimal inhibitor activity occurs when the new grain population is a tabular grain population in which the tabular grains are bounded by {100} major crystal faces.

It is particularly conceivable to epitaxially deposit the silver salt in the form of tabular grains that serve as a host. Conventional, epitaxial deposition on high chloride silver halide grains is described by Maskasky, US Pat. No. 4,435,50.
No. 11, especially Example 24B, U.S. Pat. Nos. 4,786,588 and 4,791,05 to Ogawa.
3, Hasebe et al., U.S. Pat. No. 4,820,
624 and 4,865,962, Sugi.
"Mechanism of Halide C" by moto and Miyake
onversion Process of Colloidal AgCl Microcrystals
by Br ^- Ions ", Parts I and II, Journal of Colloid
and Interface Science, Vol. 140, No. 2, 1990 12
Moon, pp. 335-361, Houle et al., US Pat.
5,992, Japanese Patent Application Laid-Open No. 03-252649 (prior application Japanese Patent Application No. 02-051165 filed on Mar. 2, 1990) and Japanese Patent Application Laid-Open No. 03-288143 (April 4, 1990). (Japanese Patent Application No. 02-089380 is a priority). The disclosures of the above US patent specifications are incorporated herein by reference.

The emulsion used in the present invention was prepared by using activated gelatin (The Theory of the Photographi of TH James).
c Process 4th Edition, Macmillan, 1977, pp. 76-76) or sulfur, selenium, tellurium, gold,
Research Disclosur with platinum, palladium, iridium, osmium, rhenium or phosphorus sensitizers, or combinations of these sensitizers, for example at pAg levels of 5-10, pH levels of 5-8 and temperatures of 30-80 ° C.
e, Vol. 120, April 1974, Item 12008, Research
Disclosure, Vol. 134, June 1975, Item 13452
U.S. Pat. No. 1,623,49 to Sheppard et al.
No. 9, Matthies et al., US Pat. No. 1,67
3,522, Waller et al., U.S. Pat.
399,083, Damschroder et al., U.S. Pat. No. 2,642,361, McVeig.
U.S. Pat. No. 3,297,447 to Dun, Dunn.
U.S. Pat. No. 3,297,446 to McBri.
deno British Patent No. 1,315,755, Be
rry et al., U.S. Pat. No. 3,772,031, G
Ilman et al., U.S. Pat. No. 3,761,267, Ohi et al., U.S. Pat. No. 3,857,711, Klinger et al. U.S. Pat. No. 3,565,633.
No. 3,901, of Oftedahl
714 and Simons British Patent No. 1,
Chemical sensitization as described by US Pat.
thiocyanate derivatives as described by Hroder in U.S. Pat. No. 2,642,361, Lowe et al. in U.S. Pat. No. 2,521,926, Williams.
U.S. Pat. No. 3,021,215 and Bi
thioether compounds described in gelow, U.S. Pat. No. 4,054,457, as well as Doses, U.S. Pat. No. 3,411,914, Kuwaba.
Ra et al., U.S. Pat. No. 3,554,757, Og.
Uchi et al U.S. Pat. No. 3,565,631 and Oftedahl U.S. Pat. No. 3,901,714.
Azaindene, azapyridazine,
As well as published European patent application No. 294149, such as azapyrimidine, Miyashi et al. And published European patent application No. 297804, such as Tanaka, and published European patent application No., such as Nishikawa. It is carried out in the presence of thiosulfonate as described in 293917. Additionally or alternatively, the emulsions can be treated with a low pAg using, for example, the hydrogen described in Janusonis US Pat. No. 3,891,446 and Babcock et al. US Pat. No. 3,984,249. (Eg lower than 5), high p
H (eg, higher than 8) treatment, or A
Llen et al., U.S. Pat. No. 2,983,609.
Research Disclosure, Vol. 136, of Oftedahl, etc.
August 1975, Item 13654, Lowe et al., U.S. Pat. Nos. 2,518,698 and 2,739,060, Roberts et al., U.S. Pat. No. 2,743,1.
82 and 2,743,183, Cham.
Bers et al U.S. Pat. No. 3,026,203 and Bigelow et al U.S. Pat. No. 3,361,564.
Reduction sensitization can be carried out using reducing agents such as stannous chloride, thiourea dioxide, polyamines and amineboranes as described in US Pat.

Chemical sensitization is described by Philipperts et al., US Pat. No. 3,628,960, Kofro.
N. et al., U.S. Pat. No. 4,439,520, Dic
Kerson U.S. Pat. No. 4,520,098, Maskasky U.S. Pat. No. 4,435,501.
U.S. Pat. No. 4,693,96 to Ihama et al.
No. 5, and Ogawa US Pat. No. 4,791,
It can be carried out in the presence of a spectral sensitizing dye as described in 053. Chemical sensitization was performed on silver halide grains as described in British Patent Application Publication No. 2,038,792 to Haugh et al. And Published European Patent Application No. 302528 to Mifrne et al. Can be directed to the site or the crystal plane. Mor
Ugan U.S. Pat. No. 3,917,485, B
Ecker, U.S. Pat. No. 3,966,476 and Research Disclosure, Vol. 181, May 1979, Item 18155, where the photosensitized centers derived from chemical sensitization are twin-jet added or silver. And partially or wholly plugged by precipitation of an additional layer of silver halide using such means as pAg circulation with separate addition of halide salts. Also, the above M
a chemical sensitizer, as described by Organ,
It can be added before or simultaneously with the additional silver halide formation. Chemical sensitization can be carried out during or after halide conversion, as described in published European patent application No. 273404 to Hasebe et al. Often, epitaxial deposition on selected tabular grain sites (eg, edges or corners) is
It can be used either for direct chemical sensitization or for itself to perform the action normally performed by chemical sensitization.

The emulsion of the present invention can be prepared by using cyanines, merocyanines, cyanines and complexes of merocyanines (for example, tri-, tetra- and polynuclear cyanines and merocyanines), styryls, merostyrils, streptocyanines, It can be spectrally sensitized with dyes from various classes, including polymethine dye classes, including hemicyanines, arylidenes, allopolar cyanines, and enamine cyanines.

Cyanine spectral sensitizing dyes are two types of basic heterocyclic nuclei connected by methine bonds, such as quinolinium, pyridinium, isoquinolinium,
3H-indolium, benzoindolium, oxazolium, thiazolium, selenazolium, imidazolium, benzoxazolium, benzothiazolium, benzoselenazolium, benzoterrazolium, benzimidazolium, naphthoxazolium, naphthothiazol Included are those derived from ium, naphthoselenazolium, naphthotelrazolium, thiazolinium, dihydronaphthothiazolium, pyrylium, and imidazopyrazinium quaternary salts.

Merocyanine spectral sensitizing dyes are cyanine dye-type basic heterocyclic and acidic nuclei connected by methine bonds, such as barbituric acid, 2-thiobarbituric acid, rhodanin, hydantoin, 2- Thiohydantoin, 4-thiohydantoin, 2-pyrazolin-5-one, 2-isoxazoline-5 one, indan-
1,3-dione, cyclohexane-1,3-dione,
1,3-dioxane-4,6-dione, pyrazoline-
3,5-dione, pentane-2,4-dione, alkylsulfonylacetonitrile, benzoylacetonitrile, malonnitrile, malonamide, isoquinoline-4
-On, chroman-2,4-dione, 5H-furan-2
-One, 5H-3-pyrrolin-2-one, 1,1,3-
Those derived from tricyanopropene and telluracyclohexanedione.

It is possible to use one or more spectral sensitizing dyes. Dyes with maximum sensitization at wavelengths across the visible and infrared spectra, and dyes with a wide variety of spectral sensitivity curve shapes are known. The choice and relative proportion of dyes depends on the region of the spectrum of sensitivity desired and on the shape of the spectral sensitization curve desired. Dyes with overlapping spectral sensitivity curves often produce a combined curve where the sensitivity at each wavelength in the overlap region is approximately equal to the sum of the sensitivities of the individual dyes. Therefore, it is possible to use a combination of dyes with different maxima to achieve a spectral sensitivity curve with a maximum midway between the sensitization maxima of the individual dyes.

Supersensitization (that is, spectral sensitization in a certain spectral region is greater than sensitization derived from any concentration of dyes alone in a plurality of dyes or sensitization derived from addition effect of a plurality of dyes. A combination of spectral sensitizing dyes that give) can be used. Supersensitization, selected combinations of spectral sensitizing dyes and other additives (eg stabilizers and antifoggants, development accelerators or inhibitors, coating aids, optical brighteners and antistatic agents). Can be achieved with. Any one of several mechanisms, as well as compounds that ensure supersensitization, can be found in Gilma.
n's Photographic Science and Engineering, Vol. 18,
1974, pp. 418-430. Spectral sensitizing dyes can also act on the emulsion in other ways.
For example, spectral sensitizing dyes can increase photographic sensitivity in the spectral region where they are inherently sensitive. Broo
Ker et al., U.S. Pat. No. 2,131,038, I
Lillingsworth et al., U.S. Pat. No. 3,501,3
No. 10, U.S. Pat. No. 3,633 to Webster et al.
0,749, Spence et al., U.S. Pat.
Spectral sensitizing dyes may also be antifoggants or stabilizers, development accelerators or suppressors, reducing or reducing agents, as disclosed in U.S. Pat. No. 3,918,470 and Shiba et al., U.S. Pat. No. 3,930,860. It can also act as a nucleating agent and a halogen or electron acceptor.

In particular, useful spectral sensitizing dyes to sensitize the emulsions described herein are British Patent 742,112, Brooker US Pat. No. 1,846,300.
Issue No. 1,846,301 Issue No. 1,846,302
Issue 1, 846, 303 Issue 1, 846, 304
No. 2,078,233 and 2,089,72
No. 9, Brooker et al., US Pat. No. 2,16
5,338, 2,213,238, 2,49
3,747, 2,493,748, 2,52
No. 6,632, No. 2,739,964, (Reissue Patent No. 24,392), No. 2,778,823, No. 2,
917,516, 3,352,857, 3,4
11,916 and 3,5311,111, Sprague U.S. Pat. No. 2,503,776, Nys et al. U.S. Pat. No. 3,282,933, Riester U.S. Pat. , 660, 102
, Kampfer et al., U.S. Pat. No. 3,660,
103, Taber et al., U.S. Pat. No. 3,33.
5,010, 3,352,680 and 3,3
84,486, Lincoln et al U.S. Pat. No. 3,397,981, Fumia et al U.S. Pat. Nos. 3,482,978 and 3,623,881, Spence U.S. Pat. Third 3,718,47
No. 0 and Mee US Pat. No. 4,025,34
No. 9 (which is hereby incorporated by reference). Examples of useful supersensitizing dye combinations, non-light absorbing additives that act as supersensitizers or useful dye combinations are described in McFall et al., US Pat. No. 2,937,089, Motter US Pat. See US Pat. No. 3,506,443, and US Pat. No. 3,672,898 to Schwan et al., Which is hereby incorporated by reference.

Spectral sensitizing dyes can be added at any stage during emulsion preparation. Wall's Phot
ographic Emulsions, American Photographic Publishi
ngCo., Boston, 1929, p. 65, Hill U.S. Pat. No. 2,735,766, Philippaert.
U.S. Pat. No. 3,628,960, Loc, et al.
Ker et al., U.S. Pat. No. 4,225,666 and Research Disclosure, Vol. 181, May 1979, Item 18155, and Tani et al., Published European Patent Application No. 301508. , They can be added at the beginning of precipitation or during precipitation. U.S. Pat. No. 4,439,520 to Kofron et al., U.S. Pat. No. 4,520 to Dickerson,
098, Maskasky U.S. Pat. No. 4,4.
35,501 and Philippaerts
They can be added before or during chemical sensitization, as described in the above cited references. Published European patent application No. 2871 of Asami et al.
They can be added before or during emulsion washing, as described in published patent application No. 00 and published European patent application 291399 to Metoki et al. Collins et al., U.S. Pat.
The dye can be mixed directly prior to coating, as described in US Pat. A small amount of iodide can be adsorbed on the emulsion grains to promote aggregation and adsorption of the spectral sensitizing dye, as described in the above-referenced Dickerson. Post-processing dye stain can be reduced by the proximity of the high iodide grains to the dyed emulsion layer, as described by Dickerson. According to their solubility, the spectral sensitizing dyes, as a solution of water or a solvent such as methanol, ethanol, acetone or pyridine, are described in US Pat. No. 3,822,135 to Sakai et al. Dissolved in an agent solution, or in US Pat. No. 3,469,987 to Owens et al.
It can be added to the emulsion as a dispersion described in No. 24185. Selective adsorption of dyes to specific crystallographic planes of emulsion grains as a means of limiting chemosensitization centers to other crystallographic planes, as described in published European patent application No. 302528 to Mifune et al. be able to. Published European patent application No. 2 by Miyasaka et al.
No. 70079, No. 270082 and No. 278510
Spectral sensitizing dyes can be used with poorly adsorbed luminescent dyes as described in US Pat.

The selection of a particular spectral sensitizing dye will now be described: SS-1 Anhydro-5'-chloro-3'-di- (3-sulfopropyl) naphtho [1,2-d] -thiazolothiacyanine. Hydroxide, sodium salt SS-2 Anhydro-5'-chloro-3'-di- (3-sulfopropyl) naphtho [1,2-d] -oxazolothiacyanine hydroxide, sodium salt SS-3 Anhydro-4 , 5-benzo-3′-methyl-4′-phenyl-1- (3-sulfopropyl) naphtho [1,2-
d] -thiazolo thiazolocyanine hydroxide SS-
4 1,1'-Diethylnaphtho [1,2-d] thiazolo-
2'-cyanine bromide SS-5 anhydro-1,1'-dimethyl-5,5'-di- (trifluoromethyl) -3- (4-sulfobutyl) -3 '
-(2,2,2-trifluoroethyl) benzimidazolocarbocyanine hydroxide SS-6 anhydro-3,3 '-(2-methoxyethyl) -5,
5'-diphenyl-9-ethyloxacarbocyanine,
Sodium salt SS-7 Anhydro-11-ethyl-1,1'-di- (3-sulfopropyl) naphtho [1,2-d] -oxazolocarbocyanine hydroxide, sodium salt SS-8 Anhydro-5,5 '-Dichloro-9-ethyl-3,
3'-di- (3-sulfopropyl) -oxaselenacarbocyanine hydroxide, sodium salt SS-9 5,6-dichloro-3 ', 3'-dimethyl-1,1',
3-Triethylbenzimidazolo-3H-indolocarbocyanine bromide SS-10 Anhydro-5,6-dichloro-1,1-diethyl-3
-(3-Sulfopropylbenzimidazoloxacarbocyanine hydroxide SS-11 anhydro-5,5'-dichloro-9-ethyl-3,
3'-di- (2-sulfoethyl-carbamoylmethyl)
Thiacarbocyanine hydroxide, sodium salt SS-12 anhydro-5 ', 6'-dimethoxy-9-ethyl-5
-Phenyl-3- (3-sulfobutyl) -3 '-(3-
Sulfopropyl) -oxathiacarbocyanine hydroxide, sodium salt SS-13 anhydro-5,5'-dichloro-9-ethyl-3-
(3-phosphonopropyl) -3 ′-(3-sulfopropyl) thiacarbocyanine hydroxide SS-14 anhydro-3,3′-di- (2-carboxyethyl)
-5,5'-Dichloro-9-ethyl-thiacarbocyanine bromide SS-15 Anhydro-5,5'-dichloro-3- (2-carboxyethyl) -3 '-(3-sulfopropyl) thiacyanine, sodium salt SS-16 9- (5-barbituric acid) -3,5-dimethyl-3 '
-Ethyl telluriacarbocyanine bromide SS-17 anhydro-5,6-methylenedioxy-9-ethyl-
3-Methyl-3 '-(3-sulfopropyl) tellurathiacarbocyanine hydroxide SS-18 3-ethyl-6,6'-dimethyl-3'-pentyl-
9,11-Neopentyrentyazicarbocyanine bromide SS-19 Anhydro-3-ethyl-9,11-neopentylene-
3 '-(3-Sulfopropyl) -thiadicarbocyanine hydroxide SS-20 Anhydro-3-ethyl-11,13-neopenthylene-3'-(3-sulfopropyl) -oxathiatricarbocyanine hydroxide, sodium Salt SS-21 Anhydro-5-chloro-9-ethyl-5'-phenyl-3 '-(3-sulfobutyl) -3- (3-sulfopropyl) oxacarbocyanine hydroxide, sodium salt SS-22 Anhydro-5 , 5'-diphenyl-3,3'-di-
(3-sulfobutyl) -9-ethyl-oxacarbocyanine hydroxide, sodium salt SS-23 anhydro-5,5'-dichloro-3,3'-di- (3
-Sulfopropyl) -9-ethyl-thiacarbocyanine hydroxide, triethylammonium salt SS-24 anhydro-5,5'-dimethyl-3,3'-di- (3
-Sulfopropyl) -9-ethyl-thiacarbocyanine hydroxide, sodium salt SS-25 anhydro-5,6-dichloro-1-ethyl-3- (3
-Sulfobutyl) -1 '-(3-sulfopropyl) benzimidazolonaphthothio [1,2-d] thiazolocarbocyanine hydroxide, triethylammonium salt SS-26 anhydro-11-ethyl-1,1'- Di- (3-sulfopropyl) naphtho [1,2-d] oxazolocarbocyanine hydroxide, sodium salt SS-27 anhydro-3,9-diethyl-3'-methylsulfonylcarbamoylmethyl-5-phenyloxathiacarbo Cyanine p-toluenesulfonate SS-28 Anhydro-6,6'-dichloro-1,1'-diethyl-3,3'-di- (3-sulfopropyl) -5,5'-
Bis (trifluoromethyl) benzimidazole carbocyanine hydroxide, sodium salt SS-29 anhydro-5'-chloro-5-phenyl-3,3'-
Di- (3-sulfopropyl) oxathiacarbocyanine hydroxide, sodium salt SS-30 Anhydro-5,5'-dichloro-3,3'-di- (3
-Sulfopropyl) thiacyanine hydroxide, sodium salt SS-31 3-ethyl-5- [1,4-dihydro-1- (4-sulfobutyl) pyridine-4-ylidene] rhodannin, triethylammonium salt SS-321- Carboxyethyl-5- [2- (3-ethylbenzoxazoline-2-ylidene) -ethylidene] -3-phenylthiohydantoin SS-33 4- [2-((1,4-dihydro-1-dodecylpyridine-ylidene ) Ethylidene] -3-phenyl-2-isoxazolin-5-one SS-34 5- (3-ethylbenzoxazoline-2-ylidene)
-3-Phenylrhoddanine SS-35 1,3-Diethyl-5-{[1-ethyl-3- (3-sulfopropyl) benzimidazoline-2-ylidene] ethylidene} -2-thiobarbituric acid SS-36 5- [2- (3-Ethylbenzoxazoline-2-ylidene) ethylidene] -1-methyl-2-dimethylamino-4-oxo-3-phenylimidazolium p-toluenesulfonate SS-37 5- [2- ( 5-carboxy-3-methylbenzoxazoline-2-ylidene) ethylidene] -3-cyano-4
-Phenyl-1- (4-methylsulfonamido-3-pyrrolin-5-one SS-38 2- [4- (hexylsulfonamido) benzoylcyanomethine] -2- [2- {3- (2-methoxyethyl) )
-5-[(2-Methoxyethyl) sulfonamide] -benzoxazoline-2-ylidene} ethylidene] acetonitrile SS-39 3-methyl-4- [2- (3-ethyl-5,6-dimethylbenzoterrazoline- 2-ylidene) ethylidene]-
1-phenyl-2-pyrazolin-5-one SS-40 3-heptyl-1-phenyl-5- {4- [3- (3-
Sulfobutyl) -naphtho [1,2-d] thiazoline]-
2-Butenylidene} -2-thiohydantoin SS-41 1,4-phenylene-bis (2-aminovinyl-3-methyl-2-thiazolinium) dichloride SS-42 anhydro-4- {2- [3- (3- Sulfopropyl)
Thiazoline-2-ylidene] -ethylidene} -2- {3
-[3- (3-Sulfopropyl) thiazoline-2-ylidene] propenyl-5-oxazolium, hydroxide, sodium salt SS-43 3-carboxymethyl-5- {3-carboxymethyl-
4-oxo-5-methyl-1,3,4-thiadiazoline-2-ylidene) ethylidene] thiazoline-2-ylidene} rhodanine, dipotassium salt SS-44 1,3-diethyl-5- [1-methyl-2 -(3,5-
Dimethylbenzoterrazoline-2-ylidene) ethylidene] -2-thiabarbituric acid SS-45 3-Methyl-4- [2- (3-ethyl-5,6-dimethylbenzotelrazoline-2-ylidene) -1 -Methylethylidene] -1-phenyl-2-pyrazolin-5-one SS-46 1,3-diethyl-5- (1-ethyl-2- (3-ethyl-5,6-dimethoxybenzoterrazoline-2- Ylidene) ethylidene] -2-thiobarbituric acid SS-47 3-ethyl-5-{[(ethylbenzothiazoline-2-
Ylidene) -methyl]-[(1,5-dimethylnaphtho [1,2-d] selenazoline-2-ylidene) methyl]
Methylene} rhodanine SS-48 5- {bis [(3-ethyl-5,6-dimethylbenzothiazoline-2-ylidene) -methyl] methylene} -1,
3-Diethyl-barbituric acid SS-49 3-Ethyl-5-{[(3-ethyl-5-methylbenzotelazoline-2-ylidene) -methyl]-[1-ethylnaphtho [1,2-d]- Tellrazolin-2-ylidene) methyl] methylene} rhodamine SS-50 anhydro-5,5′-diphenyl-3,3′-di-
(3-Sulfopropyl) thiacyanine hydroxide, triethylammonium salt SS-51 anhydro-5-chloro-5'-phenyl-3,3'-
Di- (3-sulfopropyl) thiacyanine hydroxide, triethylammonium salt Instability increasing the maximum density of negative emulsion coatings (ie,
Fog) can be prevented by incorporating stabilizers, antifoggants, antikink agents, latent image stabilizers and similar additives into the emulsion and adjacent layers prior to coating. Many antifoggants useful in the emulsions used in this invention can also be used in the developer, C.I. E. K. M
eer's The Theory of Photographic Process, 2nd
Edition, Macmillan, 1954, pp. 677-680,
It is classified under a few general headings.

To avoid such instability in the emulsion coating, stabilizers and antifoggants can be used,
They are, for example, halide ions (eg bromide salts), US Pat. No. 2,566,2 to Trivelli et al.
The chloroparadates described in 63
opalladate) and chloropalladit
e), Jones U.S. Pat. No. 2,839,405 and Sidebotham U.S. Pat. No. 3,48.
Water-soluble inorganic salts of magnesium, calcium, cadmium, cobalt, manganese and zinc described in US Pat. No. 8,709, Allen et al., US Pat. No. 2,72.
Mercury salt as described in 8,663, Brow
n et al., British Patent No. 1,336,570 and P.
Selenol and diselenide, Alll, et al., described in British Patent 1,282,303, All.
En et al., U.S. Pat. No. 2,694,716, Br.
Uker et al., U.S. Pat. No. 2,131,038, Graham U.S. Pat. No. 3,342,596 and Arai et al. U.S. Pat. No. 3,954,478.
The quaternary ammonium salts described in the specification, Th
azomethine desensitizing dyes described in US Pat. No. 3,630,744 to Herers et al., US Pat. No. 3,220,839 to Herz et al. and US Pat. No. 2,514,650 to Kott et al. Derivatives described in US Pat. No. 3,274,002 to Savron, US Pat. No. 3,565,625 to Thiazolidine, and Maffet to US Pat. No. 3,274,002. Peptide derivatives, Welsh U.S. Pat. No. 3,161,515 and Hood
Pyrimidine and 3-pyrazolidone described in U.S. Pat. No. 2,751,297, Balda, et al.
Azotriazoles and azotetrazoles described in US Pat. No. 3,925,086 to Ssarri et al., Heimbach US Pat. No. 2,444,6.
No. 05, Knott US Pat. No. 2,933,3
88, Williams U.S. Pat. No. 3,20
2,512, Research Disclosure, Vol. 134,
June 1975, Item 13452 and Vol. 148, 1976
August 14th, Item 14851, and Azaindene (especially tetraazaindene), Kenda as described in British Patent No. 1,338,567 to Nepker et al.
11 et al., U.S. Pat. No. 2,403,927, Ke.
Nnard et al., U.S. Pat. No. 3,266,897, Research Disclosure, Vol. 116, December 1973, item 11684, Luckey et al., U.S. Pat.
US Pat. No. 2,2, mercaptotetrazole, mercaptotriazole and mercapdiazol, Peterson et al., Described in US Pat. No. 7,987 and Salesin, US Pat. No. 3,708,303.
No. 71,229 and Research Disclosur mentioned above
e, the azoles described in Item 11684, She
U.S. Pat. No. 2,319,090 to Ppard et al., U.S. Pat. No. 2,152,460 to Birr et al., Research Disclosure, Item 13452, above, and French Patent No. 2,296,204 to Dotes et al.
Purines described in US Pat. No. 3,926,635, 1,3-dihydroxy (and / or 1,3-carbamoxy) -2-methylenepropanes described in US Pat. No. 3,926,635. , And Gunt
Tellurazole, tellrazoline, tellurazolinium and tellurazolium salts described in Her et al., US Pat. No. 4,661,438, Gunther US Pat. No. 4,581,330 and Przyk.
US Pat. No. 4,661,43 to lek-Elling et al.
No. 8 and 4,677,202, which are aromatic oxaterradinium salts. Miyo
elemental sulfur as disclosed in published European patent application No. 294149 to Shi et al. and published European patent application No. 297804 to Tanaka et al.
The presence of thiosulfonates (especially upon chemical sensitization) as described in published European Patent Application No. 293917 to Kawa et al. can stabilize high chloride emulsions.

Stabilizers that are especially effective in gold-sensitized emulsions are benzothiazole, benzoxazole, naphthothiazole and Yutzy et al., US Pat.
Water-soluble gold compounds of certain merocyanine and cyanine dyes described in 7,915 and sulfinamides described in US Pat. No. 3,498,792 to Nishio et al.

Among other effective stabilizers in layers containing poly (alkylene oxide) are Carroll et al. US Pat. No. 2,716,062, British Patent No. 1,46.
6,024 and Habu et al., U.S. Pat.
Tetraazaindene (especially in combination with a Group VIII noble metal or resorcinol derivative) as described in 929,486, Quaternary ammonium as described in Piper US Pat. No. 2,886,437. Salt, Maffet U.S. Pat. No. 2,953,45
Water-insoluble hydroxide described in No. 5, Smith
U.S. Pat. Nos. 2,955,037 and 2,952
Phenols described in 5,038, Ders
ch. U.S. Pat. No. 3,582,346, ethylene diurea, Wood U.S. Pat. No. 3,61.
Barbituric acid derivatives described in US Pat. No. 7,290,290, Borane described in Bigelow, US Pat.
3-pyrazolidinone as described in US Pat. No. 158,059, as well as British Patent No. 988,052 to Butler et al.
Aldoximines, amides, anilides and esters described in the specification.

Emulsions of the present invention are disclosed in additives such as the sulfocatechol-type compounds described in Kennard et al., US Pat. No. 3,236,652, Carroll et al., GB 623,448. Aldoximine Explained, US Patent No. 2,23 to Draisbach
Fog and copper, lead, tin, by incorporating the meta- and polyphosphates described in US Pat. No. 9,284, and carboxylic acids such as ethylenediaminetetraacetic acid described in British Patent No. 691,715. It is possible to prevent desensitization caused by a small amount of metal such as iron.

In layers containing synthetic polymers of the type used as vehicles and improving covering power, among others, effective stabilizers are monovalent and polyvalent compounds described in Forsgard US Pat. No. 3,043,697. -Valent phenols, British Patent No. 897,497 and Stevens et al. British Patent No. 1,039,471.
And the quinoline derivatives described in US Pat. No. 3,446,618 to Dersch et al.

Stabilizers that are particularly useful in protecting emulsion layers against two-color fog are described in US Pat. Nos. 3,679,424 and 3,820,998 to Barbier et al. Nitron salt-like additives, Wi
llems et al., U.S. Pat. No. 3,600,178, and mercaptocarboxylic acids, as well as E.I. J. B
Stabilization of Photographic Silver Halid of irr
e Emulsions, Focal Press, London, 1974, pages 126-218.

Particularly useful stabilizers for protecting emulsion layers against development fog are Bloom et al., British Patent 1,356,142 and US Pat. No. 3,57.
5,699, Rogers U.S. Pat. No. 3,4.
73,924 and additives such as azabenzimidazole described in Carlson et al., U.S. Pat. No. 3,649,267, Brooker et al., U.S. Pat. No. 2,131,038, Laud. U.S. Pat. No. 2,704,721, Rogers et al. U.S. Pat. No. 3,265,498, substituted benzimidazoles, benzothiazoles, benzothyrazoles, etc. 2,432,864, Rauch et al., U.S. Pat. No. 3,081,170, Weyerts et al., U.S. Pat. No. 3,260,597, Grassho.
ff, et al., U.S. Pat. No. 3,674,478 and Arondo, U.S. Pat. 3,2
Isothiourea derivatives described in U.S. Pat. No. 20,839, as well as von Kong US Patent 3,364,364.
No. 028 and von Kong et al., British Patent No. 1,186,441.

When using an aldehyde type curing agent,
Mono- and polyhydric phenols of the type described in Sheppard et al., U.S. Pat. No. 2,165,421, nitros of the type disclosed in Rees et al., British Patent No. 1,269,268. A substituted compound,
Poly (alkylene oxide) as described in Valbusa's British Patent 1,151,914, as well as All.
En et al., U.S. Pat. Nos. 3,232,761 and 3,
Such as mucohalogenic acid in combination with urazole as described in US Pat. No. 3,232,764, or mucohalogenic acid in combination with maleic hydrazide as further described in US Pat. No. 3,295,980 to Rees et al. The antifoggant can protect the emulsion layer.

Parabanic acid, hydantoic acid hydrazide and urazole, as described in Anderson et al., US Pat. No. 3,287,135, and two symmetrical layers, to protect the emulsion layers coated on the linear polyester support. Additives such as piazines with chemically fused 6-membered cyclic carbons, especially those in combination with aldehyde-type hardeners described in US Pat. No. 3,396,023 to Rees et al., Can be used. .

Kink desensitization of emulsions is described by Overman, US Pat. No. 2,628,167, thallium nitrate, Jones et al., US Pat. No. 2,759,8.
21 and 2,759,822, compounds of the type disclosed, polymer crystal lattices and dispersions, Re
search Disclosure, Vol. 116, December 1973, item
11684, hydrophilic colloidal dispersions of azole and mercaptotetrazole, of the type disclosed in US Pat. No. 3,033,680 to Milton et al., Plasticized gelatin compositions of the type disclosed in US Pat. Water-soluble copolymers of the type disclosed in 3,536,491, Pearson et al., U.S. Pat. No. 3,773.
Polymer crystal lattices prepared by emulsion polymerization in the presence of poly (alkylene oxide) as disclosed in US Pat. No. 3,832, Rakoczy.
It can be reduced by incorporating a gelatin graft copolymer of the type disclosed in 7,861.

When the photographic element is processed in a hot bath or hot drying temperature, such as in a fast access processor, pressure insensitivity and / or increased fog is
US Pat. No. 3,295,976 to Bbot et al.,
Barnes et al., U.S. Pat. No. 3,545,971, Salesin U.S. Pat. No. 3,708,303, Yamamoto et al. U.S. Pat.
619, Brown et al., U.S. Pat. No. 3,62.
No. 3,873, Taber US Pat. No. 3,673.
1,258, Abele, U.S. Pat. No. 3,79.
No. 1,830, Research Disclosure, Vol. 99,1
July 972, Item 9930, US Patent 3,843,364 to Florens et al., US Patent 3,867,152 to Priem et al., US Patent 3,967,965 to Adach et al. Description and Mika
U.S. Pat. Nos. 3,947,274 and 3,
Controlled by selected combinations of additives, vehicles, hardeners and / or processing conditions as described in US Pat. No. 954,474.

P, known to prevent latent image fading,
In addition to increasing H or lowering the pAg of the emulsion and adding gelatin, Ezekiel, British Patent Nos. 1,335,923, 1,378,35
No. 4, No. 1,378,654 and No. 1,391,6
72, Ezekiel et al., British Patent No. 1,39
4,371, Jefferson, U.S. Pat. No. 3,843,372, Jefferson et al., British Patent 1,412,294 and Thur.
Amino Acids Explained in Ston UK Patent No. 1,343,904, US Pat. No. 3,4 to Seiter et al.
Carbonyl-bisulfite addition products in combination with hydroxybenzene or aromatic amine developing agents, described in US Pat. No. 3,447,926 to Beckett et al. Cycloalkyl-1,3-diones, catalase-type enzymes described in US Pat. No. 3,600,182 to Matejec et al., US Pat. No. 3,881,933 to Kumai et al. A halogen-substituted curing agent in combination with certain cyanine dyes,
Hardeners described in Hong et al., US Pat. No. 3,386,831, Arai et al., US Pat. No. 3,953.
Alkenylbenzothiazolium salts described in US Pat. No. 4,478, Thurston, British Patent 1,30.
US Pat. No. 3,519,4 to Sutherns, a hydroxy-substituted benzylidene derivative as described in U.S. Pat. No. 8,777,773 and Ezekiel et al.
27. Mercapto-substituted compounds of the type disclosed in US Pat. No. 3,639, Matejec et al.
Metal-organic complexes of the type disclosed in 128, E
Zekiel's British Patent No. 1,389,089, penicillin derivatives, von Konig et al., U.S. Patent No. 3,910,791, benzimidazoles, pyrimidines and other propynylthio derivatives, Yamasue. U.S. Pat. No. 3,901,71
Combination of iridium and rhodium compounds disclosed in U.S. Patent No. 3,881,931 to Noda et al.
No. 9, sydnone or sydnonimine, the thiazolidine derivatives described in Ezekiel's British Patent No. 1,458,197, and Research.
Disclosure, Vol. 136, August 1975, latent image stabilizers such as thioether substituted imidazoles, described in item 13651, can be incorporated.

In addition to the features of tabular grain emulsion preparation methods specifically discussed, the resulting tabular grains and additional use in photography can take any convenient conventional form. Possible to replace ordinary emulsions of the same or similar silver halide composition, replacing silver halide emulsions with different halogen compositions, especially other tabular grain emulsions are also possible in many types of photographic applications Is. The inherently low levels of blue sensitivity of the high chloride {100} tabular grain emulsions of this invention are found in both Ko in terms of layer sequence and the normal function of photographic elements containing tabular grain emulsions.
Any of the layer sequence orders disclosed in US Pat. No. 4,439,520 to Fron et al., which is hereby incorporated by reference, including those desired in a multicolor photographic element. Can be used in the order of layer arrangement. Normal function is explained by reference to the following disclosure: ICBR-1 Research Disclosure, Vol. 308, 1989.1
2, Item 308,119, ICBR-2 Research Disclosure, Vol.225, 1983.
1, Item 22,534, ICBR-3 Wey et al., U.S. Pat. No. 4,414,30
No. 6, (issued Nov. 8, 1983) ICBR-4 solberg et al., U.S. Pat. No. 4,43.
3,048, (issued February 21, 1984), ICBR-5 Wilgus et al., U.S. Pat. No. 4,43.
4,226, issued Feb. 28, 1984, ICBR-6 Mskasky, U.S. Pat. No. 4,43.
5,501, issued February 6, 1984, ICBR-7 Mskasky, U.S. Pat. No. 4,64.
3,996, (issued February 17, 1987), ICBR-8 Daubendiek, et al., U.S. Pat. No. 4,672,027, (issued January 9, 1987), ICBR-9 Daubendiek, etc. U.S. Pat. No. 4,693,964, issued Sep. 15, 1987, ICBR-10 Mskasky U.S. Pat. No. 4,71.
3,320, (December 15, 1987), ICBR-11 Saitou et al., U.S. Pat. No. 4,79.
7,354, issued Jan. 10, 1989, ICBR-12 Ikeda et al., U.S. Pat. No. 4,80.
6,461, issued Feb. 21, 1989, ICBR-13 Makino et al., U.S. Pat. No. 4,85.
3,322, (August 1, 1989), ICBR-14 Daubendiek et al., U.S. Pat. No. 4,914,014, (April 3, 1990).

Photographic elements comprising high chloride {100} tabular grain emulsions in accordance with this invention can be imagewise exposed using various forms of energy. The forms of energy include the ultraviolet, visible (eg actinic) and infrared regions of the electromagnetic spectrum and electron beam radiation, either incoherent (out of phase) or coherent (in phase), and β, γ, X Includes rays, alpha particles, and neutron energy. Exposure is monochromatic, color matching,
It can be full color. Imagewise exposure in a room, at high or low temperature and / or pressure, including high or low intensity exposure, continuous or intermittent exposure, exposure times over relatively short times from minutes to milliseconds to microseconds and overexposure. By TH James's The theory of t
he Photographic Process 4th edition, Macmillan, 1977,
It can be used within the useful response range determined by the usual sensitometric techniques described in chapters 4, 6, 17, 18 and 23.

[0091]

EXAMPLES The invention can be better evaluated by reference to the following examples. Throughout the example, 1-
The acronym "APMT" was used to indicate (3-acetamidophenyl) -5-mercaptotetrazole.
Unless otherwise indicated, the term "low methionine gelatin" refers to
Used to refer to gelatin that has been treated with an oxidizing agent to reduce its methionine content below 30 μm / g. The acronym "DW" is used to indicate distilled water. The acronym "mppm" is used to indicate the molar part per million. Emulsions: AK (Comparative) These examples are from Bogg U.S. Pat. No. 4,063,95.
Iterative practice is described to produce {100} tabular grain emulsions in accordance with the technique of No. 1 specification. Bo
Initial emulsion preparations also used iodide and bromide salts, as only the examples provided by gg suggest silver iodobromide emulsions. Subsequent preparations contemplated chloride and iodochloride emulsion preparations. Emulsion: A 5.0 wt% bone gelatin, 2000 ml of a solution of 0.2 ml of tributyl phosphate defoamer in a reaction vessel at a temperature of 65 ° C. while stirring at a high pitch of 250 rpm with a three-piece propeller having a diameter of 7.6 cm. I put it in. The initial pH is
It was 5.74. While stirring this solution, a solution of 4.7 mol of silver nitrate and a solution of 4.465 mol of ammonium bromide and 0.235 mol of ammonium iodide were simultaneously added while controlling the pAg to 6.0.
Added at a rate of 1.2 ml / min for 22.2 minutes. afterwards,
The temperature was reduced linearly to 45 ° C over 10 minutes. After the temperature had dropped, 147 ml of 11.8 molar ammonium hydroxide solution was added rapidly and the mixture was held for 10 minutes. The pBr after adding ammonia was 3.25.

The resulting emulsion contained relatively polydisperse cubic grains with rounded corners. 20,000
Observing over 672 particles under a 0X scanning electron microscope (SEM), 21 particles (3%) show a slightly rectangular shape with adjacent edge length ratios less than 1.3 and typically 1.1. It was SEM observation of particles tilted such that the thickness was observable showed that few particles were clearly present with rectangles showing aspect ratios less than 2.

Emulsion: B stirring was improved by increasing the number of revolutions of the B propeller to 600, centering around the tolerance of pAg variation during preparation.
The precipitation method was the same as that used for Emulsion A except that it was more limited to pAg of 7. After adding ammonium hydroxide, the pBr was 2.7.

The resulting emulsion had an ECD of about 0.5 μm, {1
11} (ie, octahedral) crystallographic planes were included. Emulsion: The same precipitation method used for Emulsion A except that the C propeller was replaced with a high speed stirrer operating at 5000 rpm. The variation range of pAg was limited to the range of 5.7 to 6.5, with pAg 6.1 being the center. After adding ammonium hydroxide, the pBr was 2.7.

The resulting emulsion had an average EC of about 0.5 μm.
D, containing polydisperse spherical particles exhibiting {111} crystal faces. Emulsion: 18.1 ml of 4.7 immediately after adding ammonium hydroxide.
The same precipitation method was used for Emulsion B except that molar silver nitrate was added to reduce excess halide and the pBr was increased to 3.5 during the 10 minute ripening period.

The sample emulsion taken before lowering the temperature to 45 ° C. exhibited a relatively monodisperse cubic population with an edge length of about 0.2 μm, similar to that described by Bogg. After a ripening period of 10 minutes, the emulsion consisted of almost perfect cubic grains containing rectangles and a small proportion of grains exhibiting an aspect ratio of less than 2, essentially Emulsion A.
Looked similar to.

Emulsion: E Immediately after adding ammonium hydroxide, 39.5 ml of 4.7
Molar silver nitrate is added to further reduce excess halide, and the pBr is reduced to 3.95 during the 10 minute ripening period.
The precipitation method was the same as that used for Emulsion D, except that the precipitation rate was increased. The resulting emulsion looked similar to Emulsion D.

Emulsion: Immediately after adding F ammonium hydroxide, 115 ml of 4.7 mol silver nitrate was added and pBr was adjusted to 5. during the ripening period of 10 minutes.
The precipitation method was the same as that used for Emulsion D except raised to zero. The resulting emulsion again looked like Emulsion D.

Emulsion: G Immediately after adding ammonium hydroxide, 142 ml of 4.7 mol silver nitrate was added, and pBr was adjusted to 6. during the ripening period of 10 minutes.
The precipitation method was the same as that used for Emulsion D, except raised to 1. The resulting emulsion again looked like Emulsion D.

Emulsion: Emulsion F except that the iodide content of the salt solution was reduced by a factor of 10 using a solution consisting of H 4.6765M ammonium bromide and 0.0235 ammonium iodide.
The precipitation method was the same as that used for. After adding ammonium hydroxide, the amount of 4.7 mol silver nitrate added was 124 ml.
The pBr was 5.4.

The resulting emulsion again looked like Emulsions DG. Emulsion: I The amount of silver nitrate added after adding ammonium hydroxide was 9 ml.
The same precipitation method was used for Emulsion H except that pBr was adjusted to 3.25 during the 10 minute ripening period.

The resulting emulsion again looked approximately the same as Emulsions DH. Emulsions A and D-H closely resembled the grain shapes disclosed by Bogg, U.S. Pat. And (2) differed in two ways in that the average particle diameter was about 0.3 μm. No method was known for preparing silver iodobromide emulsions with grain populations disclosed by Bogg using a precipitation method of the type taught by Bogg.

The following two emulsions represent the results obtained when ammonium bromide was replaced by ammonium chloride. Emulsion: J The same precipitation method used for Emulsion A, except the ammonium bromide and ammonium iodide solutions were replaced with equimolar amounts of ammonium chloride. PCl during aging
Was 1.5. No iodide was added.

The resulting emulsion has a wide variety of shapes, {11
It was composed of very small aspect ratio grains exhibiting a wide variety of crystal planes, including the 1} plane. Very few particles were square or rectangular, but exhibited an aspect ratio of less than 2. The corner of each particle is changing, {1
Both the 11} and {110} crystal faces are shown. The average grain ECD was about 10 μm, much larger than the previous emulsion.

Emulsion: K composition of 4.465 mol ammonium chloride and 0.26
The precipitation method was the same as that used for Emulsion J except that ammonium iodide was added to the salt solution to give 5 moles ammonium iodide. PCl during the 10 minute aging period
It was 1.6. The resulting emulsion has most of the emulsion grains
It looked almost the same as Bromide Emulsions A and D-H except that it had altered corners showing {111} or {110} crystal faces. The average grain ECD was also less than 0.5 μm, as observed for bromide emulsions. This silver iodochloroiodide emulsion also has slightly rectangular grains,
Although included in small proportions, the rectangular particles showed an aspect ratio of less than 2. As with Emulsion J, most of the grain corners changed and showed {111} faces.

From these studies, tabular grain emulsions satisfying the requirements of the invention were found to be Bogg US Pat.
It was concluded that it could not be prepared by following the teachings of 3,951. Example 1 3.52% by weight low methionine gelatin, 0.0056
A 6090 ml solution containing mol / l sodium chloride and 1.48 × 10 ⁻⁴ mol / l potassium iodide was placed in a reaction vessel at 40 ° C. with stirring. While vigorously stirring the solution, 90 ml of a 2.0 mol silver nitrate solution and 90 ml of a 1.99 mol sodium chloride and 0.01 mol potassium iodide solution were simultaneously added to 180 ml each.
Added at a rate of ml / min.

The temperature is kept at 40 ° C. and the mixture is then reduced to 1
Hold for 0 minutes. Following the hold, 1.0 molar silver nitrate solution and 1.0 molar NaCl solution were added, pCl 2.25.
Maintained at 12 ml / min for 40 minutes, then 12 m
1 / min to 33.7 ml / min increasing linearly to 233.
It was added simultaneously over 2 minutes. The pCl was adjusted with NaCl, then 1.30, and washed with ultrafiltration to a pCl of 2.0, and then NaCl was used to adjust the pCl to 1.65.

The resulting emulsion was a tabular grain silver iodochloride emulsion containing 0.03 mol% iodide having an average equivalent circular diameter of 1.51 μm and an average thickness of 0.22 μm. More than 50% of the total grain projected area was accounted for by {100} tabular grains exhibiting an average aspect ratio of 6.9. Example 2 3.52% by weight low methionine (hydrogen peroxide treated) gelatin, 0.0056 mol / l sodium chloride, 2.34 × 10 ^-4 mol / l potassium iodide and 0.3 ml 15 including polyethylene glycol defoamer
36 ml of the solution was placed in a reaction vessel at 40 ° C. with stirring. While vigorously stirring the solution, 30 ml of 2.0 mol silver nitrate solution and 30 ml of 2.0 mol sodium chloride solution were simultaneously added at a rate of 60 ml / min each.

The temperature is kept at 40 ° C. and the mixture is then cooled to 1
Hold for 0 seconds. Following the hold, 0.5 molar silver nitrate solution and 0.5 molar NaCl solution, pCl 2.35.
Maintained at 8 ml / min for 40 minutes at the same time. Thereafter, the pCl was maintained at 1.65 with 1.0 molar sodium chloride to give 0.5 molar silver nitrate solution and 0.5 molar N 2.
The aCl solution was added linearly with increasing flow rate (starting at 8 ml / min and increasing at a rate of 0.0615 ml / min), respectively. After 90 minutes, microscopic examination of the emulsion showed an equivalent circular diameter of 0.9 μm with a mean grain thickness of 0.17 μm. More than 50% of the total grain projected area was accounted for by {100} tabular grains exhibiting an average aspect ratio of 5.3.

Example 3 3.52% by weight low methionine gelatin, 0.0056
A 1.5 L (liter) solution containing mol / l sodium chloride and 0.2 ml polyethylene glycol antifoam was placed in a reaction vessel at 40 ° C. with stirring. While vigorously stirring this solution, 45 ml of 0.01 potassium iodide solution was added, then 50 ml of 1.25 molar silver nitrate and 50 ml of 1.25 molar sodium chloride solution were simultaneously added at a rate of 100 ml / min each. It was

The temperature is kept at 40 ° C. and the mixture is then reduced to 1
Hold for 0 seconds. Following the hold, a 0.625 molar silver nitrate solution containing 0.08 mg mercuric chloride per mole silver nitrate and a 0.625 molar NaCl solution were added to pCl
Were maintained at 2.35 and added simultaneously at 10 ml / min for 30 minutes each. Thereafter, 2 molar NaCl was added over 1 minute to adjust the reaction vessel pCl to 1.25. Following this, the pCl was maintained at 1.25 to give 0.625
Molar silver nitrate and 0.625 molar NaCl solutions were linearly increased in flow rate (from 10 ml / min to 15 ml respectively).
125 minutes (at the rate of ml / min), then 1 each
Simultaneous additions were made at a constant flow rate of 5 ml / min for 30 minutes. 40
g of phthalated gelatin was added and the emulsion was washed and concentrated using the procedure of Yutzy et al., US Pat. No. 2,614,918. The pCl after washing was 2.0. 21 g of low methionine gelatin was added, the pCl was adjusted to 1.65 with NaCl and the pH was adjusted to 5.7. The resulting emulsion was a silver iodochloride {100} tabular grain emulsion containing 0.036 mol% iodide. More than 90% of the total grain projected area is a rectangle {100}
It was occupied by particles with major surfaces and unchanged corner shapes. This emulsion had an average ECD of 0.89 μm and an average grain thickness of 0.34 μm.

Example 4 The pCl was increased to 1.6 during the increasing addition rate and in the last growing portion.
This emulsion was precipitated and washed like the emulsion of Example 3 except that it was maintained at 5. About 90% of the total particle projected area is
It was occupied by square and rectangular grains with {100} major faces. The average ECD of this emulsion is 1.08μ
m, and its average grain thickness was 0.25 μm.

Emulsion L (Comparative) Silver chloride {100} with average grain volume matching that of the emulsion of Example 3
Prepare this emulsion to provide a cubic grain emulsion,
This allowed for easy comparison of emulsion photographic responses. 8.0 wt% low methionine gelatin,
0.026 mol / l sodium chloride, and 1.0 m
5.0 liters of a solution containing 1 liter of ethylene oxide / propylene oxide block copolymer defoamer while stirring 6
Placed in reaction vessel at 5 ° C. While controlling the pCl to 1.6 and stirring this solution vigorously, a 4.0 mol silver nitrate solution and a 4.0 mol sodium chloride solution containing 0.08 mg of mercuric chloride per mol of silver nitrate were added.
At the same time, a rate of 18 ml / min was added for 1 minute each. Next, the pCl was controlled to 1.6, and 20
The flow rate of the silver nitrate solution and the salt solution was changed to 18 ml over a period of 18 minutes.
/ Min to 80 ml / min, then increase the flow rate to 80 ml
A constant flow rate of / min was maintained for 65 minutes. The emulsion was then washed and concentrated by ultrafiltration. An amount of 560 g of low methionine gelatin was added and the pCl was adjusted to 1.6 with NaCl.

The resulting cubic grain emulsion had an average cubic grain edge length of 0.6 μm. Example 5 Example 3 Emulsion and Emulsion L were similarly sensitized, coated and evaluated photographically. For experimental identification, a substantially optimal sensitized sample of each emulsion was prepared by adding spectral sensitizing dyes, sulfur sensitizers and gold sensitizers in addition concentrations, and holding at elevated temperature following addition of sensitizers ( It was sensitized by changing the aging time.

The general sensitization procedure is as follows:
1200 mg / mol potassium bromide was added to the sample and the emulsion sample was melted at 40 ° C. Next, the green spectral sensitizing dye SS-21 was added, followed by holding for 20 minutes. To this was added sodium thiosulfate pentahydrate, and potassium gold pentachloride. Then, the temperature of the well-stirred mixture was raised to 60 degreeC over 12 minutes, and it hold | maintained at 60 degreeC for 10 minutes. The emulsion was quenched to 40 ° C., 70 mg / mol APMT was added and the emulsion was refrigerated.

Each sample was coated on a support and silver 0.8
An antihalation layer of 5 g / m ² , 1.08 g / m ² of cyan dye-forming coupler C and 2.7 g / m ² of gelatin were provided. This layer was overcoated with 1.6 g / m ² of gelatin and the entire coating was cured with 1.75% bis (vinylsulfonylmethyl) ether of the total gelatin applied. Coat the film with Daylight V and Kodak Wrat
Exposure was through a step wedge for 0.02 seconds using a 3000 degree K tungsten light source with a ten 9 ™ filter. Apply this coating to Kodak Flexicol
or (TM) C-41 treatment.

Coupler C

[0118]

[Chemical 10]

The minimum acceptable concentration and maximum achievable sensitivity (ie, substantially optimally sensitized sample)
The photographic properties of substantially combined emulsion L and a sample of the emulsion of Example 3 were as follows: Emulsion L was 0.2
A minimum concentration of 3 was shown. It was assigned a relative sensitivity of 100. The contrast standardized granularity is 0.01
It was 8.

Example 3 The emulsion exhibited a minimum density of 0.22. Its relative sensitivity was 178. The contrast standardized granularity was 0.019. The emulsion of Example 3 showed a great sensitivity advantage. Example 3 Emulsion and Emulsion L showed slightly different granularity, but a large difference in sensitivity over and above the granularity difference. From the data, it is clear that the Example 3 emulsion shows a great sensitivity advantage over the cubic grain emulsion with a matched granularity.

Emulsion M This emulsion preparation shows that ripening from the special procedure referred to above in the 1963 Turin Symposium to produce tabular grain emulsions satisfying the requirements of the invention is ineffective. explain. At 40 ° C., 75 ml of distilled water, 6.7
5 g deionized bone gelatin and 2.25 ml 1.0
In a reaction vessel containing a molar NaCl solution, with efficient stirring, 15 ml of 1.0 molar silver nitrate solution and 15 ml
15 ml of 1.0 molar sodium chloride solution of
/ Min at the same time. The mixture is stirred at 40 ° C. for 4 minutes, then the temperature is raised to 77 ° C. over 10 minutes and 7.2
ml of 1.0 molar sodium chloride solution was added. The mixture was stirred at 77 ° C for 180 minutes and then cooled to 40 ° C.

The resulting particle mixture was examined by light and electron microscopy. The emulsion contained a population of tabular grains with small cubic crystals of approximately 0.2 μm edge length, large nontabular grains, and square or rectangular major faces. From the number of particles, small particles were overwhelmingly dominant. Tabular grains accounted for less than 25% of the total grain projected area of the emulsion.

The average thickness of the tabular grain population was measured from edge observations obtained using an electron microscope. A total of 26 tabular grains were measured and found to have an average thickness of 0.38 μm. Of the 26 tabular grains whose thickness was measured, only one had a thickness less than 0.3 μm (the tabular grain thickness was 0.25 μm).

Front Page Continuation (72) Inventor Debra Lin Harzel USA, New York 14612, Rochester, Snag Harbor Court 42 (72) Inventor Donald Lee Black USA, New York 14580, Webster, High Tower Way 803

Claims (9)

[Claims] 1. A radiation-sensitive emulsion comprising a dispersion medium and silver halide grains, wherein at least 50% of the total grain projected area is (1) {100} major faces having an adjacent edge ratio of less than 10. (2) each has an aspect ratio of at least 2 and in combination has an average aspect ratio of at most 8, and (3) substantially at their nucleation sites, iodide and at least A radiation-sensitive emulsion characterized in that it is occupied by tabular grains containing 50 mol% chloride. 2. A radiation sensitive emulsion according to claim 1, further characterized in that the tabular grains have an average aspect ratio of at least 5. 3. The radiation-sensitive emulsion according to claim 1, further characterized in that the tabular grains have an adjacent principal surface edge ratio of less than 5. 4. A radiation-sensitive emulsion according to claim 3, further characterized in that the tabular grains have an adjacent major surface edge ratio of less than 2. 5. A radiation-sensitive emulsion according to any one of claims 1 to 4, further characterized in that the tabular grains have a thickness of less than 0.8 µm. 6. A radiation-sensitive emulsion according to claim 5, further characterized in that the tabular grains have a thickness of less than 0.3 μm. 7. The radiation-sensitive emulsion according to claim 1, wherein the tabular grains further contain at least 70 mol% chloride. 8. The radiation-sensitive emulsion according to claim 7, further characterized in that the tabular grains contain at least 90 mol% chloride. 9. The radiation-sensitive emulsion according to claim 8, further characterized in that the tabular grains are silver iodochloride grains.