JPH07311431A - Radiosensitive emulsion - Google Patents

Abstract

PURPOSE: To obtain an excellent radiation-sensitive photographic emulsion by forming 100} tabular grains occupying specific % of a total grain projection area in such a manner that these grains include non- 100} edge structures. CONSTITUTION: At least 50% of the total grain projection area of this photographic emulsion is occupied by the high (>90%) chloride thin type (<0.2μm) tabular grains having the 100} main faces respectively having at least one edge surfaces oriented to the atm. faces different from those of the main faces. Namely, for instance, the tabular grains 200 are partially bordered at the parallel 100} atom faces forming the main faces 202 and 204. Further, the tabular grains 200 have the 8 edge faces including slants S1, S3, S5, S7 intersecting with the upper 100} main face 202 and slants S2, S4, S6, S8 intersecting with the lower 100} main face. The four additional edge faces 206, 208, 210, 212 are oriented perpendicularly to the 100} main faces. The respective edge faces of the grains 200 exist at the 100} atom faces.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to radiosensitive photographic emulsions.

[0002]

2. Description of the Related Art In the 1980s, a wide range of photographic advantages,
For example, improved speed-granularity relationships, increased coating power (increased coating power both on an absolute basis and as a function of binder curing), faster developability, increased thermal stability, and increased imaging speed. Based on the discovery that increased separation of native and spectral sensitization provided, and improved image sharpness in both single emulsion layer and multiple emulsion layer formats, can be achieved by using thin tabular grain emulsions. And significant advances have been made in silver halide photography. These advantages are illustrated in U.S. Pat. No. 4,439,520 to Kofron et al.

Emulsions usually have a thickness (t) of less than 0.2 μm.
Tabular grains having at least 50% of total grain projected area
When considered as a percent, it is considered a "thin tabular grain emulsion". It is readily recognizable visually that tabular grains are tabular grains when the two parallel major faces include major faces such that they are substantially larger than either of the remaining faces. Quantitatively, particles with parallel major faces are generally considered to have an aspect ratio, their ratio of equivalent circular diameter (ECD) to their thickness (t) of at least 2. Tabular grain thickness is the distance between its major surfaces.

The initial practical interest in tabular grain emulsions was camera speed with film and indirect radiography (when an intensifying screen was exposed to X-ray radiation, the tabular grains were emitted by the light emitted from the intensifying screen). Focused on applications in radiographic imaging, where the emulsion is imagewise exposed. Silver iodobromide emulsions have traditionally been preferred for camera speed films, and silver bromide emulsions (optionally containing up to about 3 mole percent iodide) for radiographic films. Thin tabular grain emulsions that provide these utilities contain tabular grains having opposed {111} major faces. The {111} major faces of the tabular grains exhibit triple symmetry, representing hexagonal or triangular.

Relatively recent interest has grown in the photographic art which combines the known advantages of thin tabular grain emulsions with the advantages of high chloride grain structures. The term "high chloride" as applied to grain structure and emulsions refers to at least 9 based on silver.
Used herein to indicate the presence of 0 mole percent chloride. The advantage of high chloride emulsions over those of other halide compositions is that the blue sensitivity is less than the original blue sensitivity (thus reducing color contamination when used as a green or red recording emulsion layer). , Faster development rates, and faster fixing with ecologically favorable sulfite fixers.

It has been recognized from the outset that in order to obtain tabular grain emulsions of different halide content, a completely different emulsion preparation strategy must be carried out. Kofron
Although others disclosed high chloride tabular grain emulsions, they faced the difficulty that silver chloride exhibits a strong preference to form grain structures in the {100} crystal faces. The high chloride tabular grain emulsions disclosed by Kofron et al. Exhibit {111} major faces. Applications of high chloride {111} tabular grain emulsions are:
This has been hindered by the need to use morphological stabilizers to prevent the high chloride {111} tabular major faces from reverting to the non-tabular form. Mignot US Patent No. 4,38
6,156 (summarized in column 17 of Kofron et al.) Discloses the preparation of silver bromide tabular grains having {100} major faces. Saito EPO 0 569 971 discloses modified-form {100} tabular grains containing at least 25 mole percent bromide.

Relatively recently, high chloride tabular grain emulsions exhibiting {100} crystal faces have been disclosed. By first preparing high chloride tabular grains in their native stable crystalline form, the complex problems associated with morphological stabilizers were eliminated and a significant level of photographic behavior was observed. The sensitivity of these emulsions approached that of the more effective silver iodobromide emulsions. These thin high chloride {100} tabular grain emulsions are described in Maskasky US Pat. No. 5,264,337.
5,275,930 and 5,292,632; House et al., US Pat. No. 5,320,938; Szajewski et al., US Pat. Nos. 5,310,635 and 5,356,764; and Brust et al., US Pat. No. 5,314,798. Indicated

K. Endo and M. Okaji, "An Empirical Rule to Modify the Crystal Habit of
Silver Chloride to Form Tabular Grains in an Emul
sion) ”, J. photographicScience, 1988, Vol. 36,
(1988), pp. 182-189, on the creation of an empirical rule for selecting materials used as grain growth modifiers in preparing silver chloride tabular grain emulsions by the double jet precipitation method. It is described in detail. Various ligands, C
^{N -, SCN -, I -} , (S 2 O 3) -2, (SO 3) -3
And thiourea (including derivatives) in 3M sodium chloride solution at concentrations of 0.001, 0.005, 0.01 and 0.1.
The rule was tested by adding M. The 3M sodium chloride solution was then used in a double jet precipitation method with 2M silver nitrate. {100} and {1
Tabular grains having an 11} plane were produced. Based on these studies, Endo et al. Have determined that the first formation constant of the ligand, β ₁ (L), is to be useful as a grain growth modifier in forming tabular grain high chloride emulsions. , Β ₂ (C
l ⁻ ) must be exceeded--that is, β ₂ (C
We have come to the conclusion that l ⁻ ) / β ₁ (L) must be less than one (1). In Table 2, Endo et al. SCN
^- a ^{/ β} ₁ (L) is 6.3, therefore, SCN for use as grain growth modifiers - of beta ₂ (Cl) ^- it has reported that it is not appropriate to direct. In Figure 7, Endo et al., Generated using 0.10M KSCN,
It shows a relatively thick population of silver chloride grains. Maskasky U.S. Pat. No. 5,061,617 discloses the use of thiocyanate as a grain growth modifier in the formation of high chloride tabular grains having {111} major faces.

[0009]

SUMMARY OF THE INVENTION In one aspect, the present invention provides a radiation-sensitive emulsion containing a population of silver halide grains comprising at least 90 mole percent chloride, based on silver. At least the projected area of the particle population
Fifty percent are (1) bounded by {100} major faces having adjacent edge ratios less than 10, and (2) 0.2.
occupied by tabular grains having a thickness of less than μm; each of the tabular grains accounting for at least 50 percent of the total grain projected area being at least in an atomic plane different from that of (3) the major surface; Containing one crystal plane and (4) exhibiting a lower grain volume than tabular grains of the same length, width and thickness all bounded by crystal planes at {100} atomic planes , Which are directed to radiation-sensitive emulsions.

By providing tabular grains having at least one edge that is in an atomic plane different from the atomic plane of the {100} major surface, a different Ag ⁺ relative to the major surface of the grain is provided.
Ion and Cl ^- ion surface patterns are provided,
And the photographic utility of the particles is enhanced. The major faces of tabular grains are in the {100} atomic planes, while the 1-12 edge surfaces of the grains are in one or more other atomic faces--that is, non- {100} crystal faces. It uses different grain behaviour-enhancing compounds (eg, spectral sensitizing dyes, chemical sensitizers, antifoggants and stabilizers) in selected combinations based on different preferred crystal plane affinities. Allow to do. This reduces competition between the surface sites of these compounds. For example, dye desensitization can be reduced by reducing the competition between chemical sensitizers and spectral sensitizing dyes. As another illustrative photographic advantage, dye replacement with antifoggants and stabilizers is minimized.

[0011]

SPECIFIC EMBODIMENT FIG. 3 specifically shows a conventional {100} tabular grain 100. The tabular grains have an upper major surface 102 and a parallel lower major surface 104. Furthermore, the particles have four edge faces 106, 108, 110 and 112 that are oriented perpendicular to the major faces. Each of the edge faces is either parallel or perpendicular to the other edge face. 6 faces, 102, 1
Each of 04, 106, 108, 110 and 112 is
It is on the {100} atomic plane.

1A, 2A and 2B show one idealized tabular grain 200 that the tabular grains in the emulsions of this invention can take. The tabular grains are
It is partially bounded by the parallel {100} atomic planes that form the major faces 202 and 204. Further, the tabular grains have slopes S1 and S that intersect the upper {100} main surface 202.
3, S5 and S7, and the lower {100} major surface 20.
Slopes S2, S4, S6 and S8 intersecting 4
It has 8 beveled edge faces. The four additional edge faces 206, 208, 210 and 212 are {100}
The orientation is vertical to the main surface. By comparing the orientation of the edge faces of particles 200 with the orientation of the edge faces of particles 100, it is clear that none of the edge faces of particles 200 are {100} atomic planes. In grain 200, each edge plane is a {110} atomic plane.

Other ideal types of tabular grains satisfying the requirements of the emulsions of this invention are shown in FIGS. 1B, 3A and 3B. The tabular grains 300 have parallel {100} major faces 3
It is partially bounded by 02 and 304. Further, the tabular grains have four edge faces 306, 30 oriented with respect to the principal plane similarly to the edge faces of the tabular grain 100.
8, 310 and 312. That is, these 4
The two edge faces are {100} crystal faces. Further, the tabular grains 300 have inclined edge surfaces S10, S30, S50 and S70 intersecting the upper major surface 302 of the grain, and inclined edge surfaces S20, S40, S60 intersecting the lower {100} major surface of the grain. And S80, 8
It has two equal inclined edge surfaces. The tilted edge plane is the {111} atomic plane.

The difference between the {100} tabular grains 100 and the ideal tabular grains 200 and 300 that meet the requirements of the present invention is that the latter has the same length, width and thickness of {1}.
00} crystal planes all exhibit lower grain volume than tabular grains bounding all. The non- {100} edges of grains 200 and 300 give the appearance of {100} tabular grains with one or more corners removed. Therefore,
The name that has been applied to these particles is "cut co
rner) ”particles (although in reality, the horns are not cut away, they are simply not formed). The advantage is that tabular grains 200 and 300 require less silver than tabular grains 100 to provide the same projected area for capturing light. Another feature that distinguishes tabular grains 200 and 300 is common to all tabular grains satisfying the requirements of the invention, with the non- {100} crystal faces being the closest {10}.
0} does not project on the main surface, and further contributes to the reduction of the particle volume based on the displacement dimensions.

The emulsions of this invention have a total grain projected area of at least 50 percent, preferably at least 70 percent, and optimally at least 90 percent {10.
Similar to conventional thin high chloride tabular grain emulsions, which are populated with tabular grains having 0} major faces. Tabular grains 100, 200 and 300 are shown to have major faces of approximately equal length and width, whereas square major faces (having apparently unequal length and width) are common. . Therefore, in order to distinguish tabular grains from more rod-like grains, the length to width ratio of the grains should be less than 10, preferably less than 5, optimally less than 2.

Tabular grains accounting for at least 50 percent of total grain projected area have a thickness of less than 0.2 μm.
In fact, the tabular grains can have any desired conventional thinner thickness. For example, the tabular grains can be ultrathin, as illustrated in the Examples below.
That is, it shows an average thickness of less than 0.07 μm. Tabular grains accounting for at least 50 percent of total grain projected area are:
Preferably it has an average aspect ratio of greater than 8, and most preferably at least 12. It is clear that tabular grain structures satisfying the edge requirements of the invention can be grown to the same thickness and ECD as conventional thin {100} tabular grain emulsions, thus achieving similar average aspect ratios.

The tabular grains contain at least 90 mole percent chloride, based on total silver. The remaining halide, if any, can be a mixture of any conventional bromide and / or iodide. Silver chloride emulsions which are deliberately free of bromide and / or iodide are particularly contemplated. As demonstrated in the Examples below, certain techniques for forming the tabular grain structures of the present invention rely on the inclusion of iodide in the grains. Thus, in certain embodiments, the preferred type of tabular grains can consist essentially of silver iodochloride. The optimum iodide concentration will vary depending on the photographic application. For example, camera speed films can accommodate iodide concentrations up to 10 mole percent. For rapid access processing in radiography, iodide levels are typically selected to be less than 3 mole percent based on silver.
Iodide levels in color print emulsions are typically maintained below 1 mole percent based on silver. In all of these affiliated photographic applications, emulsions containing up to 10 mole percent bromide can be accepted.

The common difference between each emulsion of the invention and another similar conventional emulsion is that it accounts for at least 50 (preferably at least 70, and optimally at least 90) percent of the total grain projected area. The {100} tabular grains contain a non- {100} edge structure. The ideal tabular grain structure 200 is shown to have 12 equal {110} edge faces, while the ideal grain structure 300 is shown to have 8 equal {111} edge faces. There is. Since these grains are in an ideal state, achieving emulsion precipitation with minimal random grain dispersion provides maximum control over photographic behavior. In an ideal emulsion, the tabular grain edges, which account for at least 50 percent of total grain projected area, are modified (equivalently) to be non- {100} type.

[0019] Some preparation methods help to use small particles to form an ideal particle structure to a particle dispersion (ie, monodispersity) that meets a wider range of conditions than others. Particle dispersion can be reduced by ensuring uniform availability of reactants. This is more easily achieved with smaller scale precipitation methods. In some precipitation methods where the ideal level of reactant homogeneity is not conveniently achieved (eg, larger scale precipitation methods), the tabular grain corners are unequally modified. That is, one or more non- {100} crystal faces adjacent to one corner may be larger than another. Furthermore, if one or more corners are minimally modified, it is difficult to determine whether the corners of the particles have non- {100} crystal faces or are merely rounded by aging. right.

Tabular grains having {100} major faces that account for at least 50 percent of total grain projected area are {1
Sufficient photographic advantages can be realized when including at least one crystallographic plane that is in a different atomic plane than the {00} main plane. All of the grains produced in the precipitation of high chloride emulsions exhibit a face centered cubic crystal lattice structure, whether the grains are tabular or non-tabular. Furthermore, it is independent of the atomic surface where the particle surface is. However, depending on the atomic plane with the particle surface, with Ag ⁺ and Cl particle surface ^- It is important to note that different significantly spatial pattern of. Maskasky U.S. Pat.No. 4,643,966 describes
Ag ^{+ at} four higher indices of {100}, {110}, {111} and less common crystal planes
And Br ⁻ patterns are specifically depicted. Maskas
Also the pattern shown by ky, Cl ^- is Br ^-, except that less than, and is formed by AgCl. {10
The Ag ⁺ and Cl ⁻ patterns in the 0} atomic plane are shown schematically below.

[0021]

[Chemical 1]

Ag ⁺ and C in the {110} atomic plane
The l ^- pattern is shown schematically below.

[Chemical 2]

The {111} atomic planes in the grain are all C
l ⁻ or all Ag ⁺ are arranged alternately. Since the photographic emulsion contains a stoichiometric excess of halide ions, the surface is formed with a complete layer of Ag ⁺ , C
l ^- complete or incomplete layer is believed to be superimposed in. The outermost Ag ⁺ {111} crystal plane has the following arrangement.

[Chemical 3]

The outermost Cl {111} atomic plane is the outermost Ag {1
When formed on the 11} atomic plane, each Cl ⁻ is placed equidistant from the three Ag ⁺ ions in the underlying {111} crystal plane. When the Cl ⁻ {111} atomic plane is completely formed, Cl ⁻ ions are distributed in the same pattern as shown above for Ag ⁺ ions. It is clear from the above that each different atomic plane on the surface of the tabular grains of the invention presents significantly different cation and anion patterns. Compounds that adsorb to or react with the particle surface to provide photographically useful properties select the atomic plane for ionic and stereocompatibility-based interactions.

Although the ideal grain structure has been specifically shown above by the term non- {100} grain face in the {110} or {111} atomic plane, in other words, it is non- {100} grain face. } It is recognized that the grain planes may lie on different atomic planes. Maskasky U.S. Pat. No. 4,643,966 (incorporated by reference herein) contains {1
00}, {110}, {111}, {hh1}, {hk
Disclosed are silver halide grain structures bounded by 0}, {hl1} and {hk1} atomic planes. here,
h, k and l are in each case independently unequal integers above zero, where h is greater than l and k, and in some cases k is less than h and greater than l. Although there is no theoretical limit to the maximum value of the integer h, it is usually 5 or less in practice. After the {100} tabular grain emulsion is precipitated as a host, a precipitation technique selected from those taught by Maskasky finishes grain growth and reveals one or more non- {100} crystal faces on the grain. Can be used to

The emulsion of the present invention comprises a conventional thin high chloride {1
00} tabular grain emulsion can be prepared by improving the preparation method. That is, the conventional {10 of the type shown in FIG.
0} tabular grains are precipitated first. Techniques for precipitating initial thin high aspect ratio high chloride {100} tabular grain emulsions are described by Maskasky US Pat. Nos. 5,264,337 and 5,2.
92,930 and 5,292,632; House et al., US Pat. No. 5,320,938; Szajewski et al., US Pat. Nos. 5,310,635 and 5,356,764; and Brust et al., US Pat. No. 5,314,798 (above). References are incorporated herein by reference)
Is specifically illustrated by. 50 to 98 percent of the total silver forming the emulsion of the present invention, preferably 85 to 95%,
It is precipitated under these conventional precipitation conditions. The conditions of precipitation were then modified to provide non- {100} crystal faces while finishing grain growth.

In one preferred mode of the invention, during precipitation,
Non- {100} crystal faces are formed during increasing iodide concentration to a level of at least 5 (preferably at least 7) mole percent, based on the amount of silver introduced at the same time. The iodide is silver iodide Lippman.
n) Conveniently added as an emulsion or as a soluble salt (eg KI). The iodide ion concentration level can be increased to the saturation level of iodide ion in silver chloride.
Increasing iodide concentrations above their saturation level in silver chloride runs the risk of precipitating a separate silver iodide phase. Maskasky US Pat. No. 5,288,603 (incorporated herein by reference) discusses iodide saturation levels in silver chloride and silver bromochloride. The presence of iodide during precipitation, together with other precipitation parameters, results in a tabular grain emulsion that meets the requirements of this invention. The following examples are provided as specific illustrations of how to utilize iodide incorporation combined with alternative precipitation parameters to provide tabular grain emulsions that meet the requirements of the invention. Non- {100}
When relying on iodide to provide the crystallographic planes, the tabular grains can contain as little as 0.1 mole percent iodide, based on total silver, although the grains can contain at least about 0.5 mole percent. It preferably contains iodide. Tabular grains containing up to 10 mole percent iodide can be prepared with iodide to provide non- {100} edge surfaces. This precipitation method can be carried out in the presence or absence of bromide. The sum of iodide and bromide can range up to 10 mole percent, based on total silver.

The distinct advantage of using iodide to provide non- {100} crystal planes is that inclusion of iodide in the grain structure promotes latent image formation, resulting in enhanced levels of photographic speed. It can be realized. Further, because iodide ions are incorporated into the crystal structure, they do not compete with other photographic additives for adsorption sites on the surface of tabular grains. Another option when using iodide to form the non- {100} grain faces of the present invention is the use of thiocyanate. By using thiocyanates to form the non- {100} grain faces, it is possible to precipitate the emulsions of this invention that are substantially free of iodide. The thiocyanate can be placed in the reaction vessel in the form of an alkali salt, alkaline earth salt or ammonium salt. A typical thiocyanate concentration range is 0.2 to 10 (preferably 0.5 to 5) mole percent, based on the amount of silver introduced at the same time. It is believed that thiocyanate is incorporated into the grains because silver thiocyanate is less soluble than silver chloride. As shown in FIG. 5, during the latter stages of precipitation, the particles prepared in the presence of thiocyanate do not meet the permissible {100} atomic plane orientation and thus are non- {100} crystal faces. Shows at least one crystal face, which is easily recognized. A specific technique for producing the tabular grain emulsions of this invention using thiocyanate is illustrated in the examples below. Non {10
It will be appreciated that instead of choosing thiocyanate or iodide to produce the 0} grain edges, both can be used together.

In yet another method of this invention, the selected organic compound can be used to produce {100} tabular grains having non- {100} crystal faces. In the examples below, 4,5,6-triaminopyrimidine and 2,4,6-triiodophenol, which are known as grain growth modifiers for producing {111} grain faces, and {110} grain faces. 1- (3-acetamidophenyl) -known as a grain growth modifier for producing
It has been shown that 5-mercaptotetrazole successfully produces non- {111} edge faces on high chloride {100} tabular grains.

4,5,6-triaminopyrimidine is
skasky US Pat. No. 5,185,239, the disclosure of which is incorporated herein by reference, is an example of a formula defining a series of {111} growth modifiers. Mention. Particularly disclosed compounds include, in addition to 4,5,6-triaminopyrimidine,
5,6-diamino-4- (N-methylamino) pyrimidine, 4,5,6-tri (N-methylamino) pyrimidine, 4,6-diamino-5- (N, N-dimethylamino) pyrimidine and 4 , 6-diamino-5- (N-hexylamino) pyrimidine. Similar utility is expected for the various 7-azaindole grain growth modifiers disclosed in Maskasky US Pat. No. 5,178,997, the disclosure of which is incorporated herein by reference. It In addition to 7-azaindole, specifically disclosed compounds include 4,7-diazaindole, 5,7-diazaindole, 6,7-diazaindole, purine, 4-azabenzimidazole,
4,7-diazabenzimidazole, 4-azabenzotriazole, 4,7-diazabenzotriazole and 1,2,5,7-tetraazaindene are mentioned.

Similarly, 2,4,6-triiodophenol was filed on July 27, 1994 and is now patented by Maskas.
ky U.S. Patent Application No. 281,283, the disclosure of which is incorporated herein by reference
Are specific examples of the series of polyiodophenol {111} grain growth modifiers disclosed in US Pat. In addition to 2,4,6-triiodophenol, specifically disclosed compounds include:
2,6-diiodophenol, 2,6-diiodo-4-
Nitrophenol, 2,6-diiodo-4-methylphenol, 4-allyl-2,6-diiodophenol, 4
-Cyclohexyl-2,6-diiodophenol, 2,
6-diiodo-4-phenylphenol, 4,6-diiodo-2-acetophenone, 4,6-diiodothymol, 4,6-diiodocarbachlor, 3,5-diiodo-L-tyrosine, 3 ', 3 Examples include ", 5 ', 5" -tetraiodophenolphthalein, erythrosine and rose bengal. A structurally similar polyiodophenol particle growth modifier was filed on July 27, 1994 and is now patented by Maskasky in US Patent Application No.
281,500, the iodoquinoline {111} grain growth modifiers disclosed in US Pat. No. 4,801,500, the disclosure of which is incorporated herein by reference. Specific examples of iodoquinoline particle growth modifiers include 5-chloro-
8-hydroxy-7-iodoquinoline, 8-hydroxy-7-iodo-2-methylquinoline, 4-ethyl-8-
Hydroxy-7-iodoquinoline, 5-bromo-8-hydroxyiodoquinoline, 5,7-diiodo-8-hydroxyquinoline, 8-hydroxy-7-iodo-5-quinolinesulfonic acid, 8-hydroxy-7-iodo- 5-
Quinolinecarboxylic acid, 8-hydroxy-7-iodo-5
-Iodomethylquinoline, 8-hydroxy-7-iodo-5-trichloromethylquinoline, α- (8-hydroxy-7-iodoquinoline) acetic acid, 7-cyano-8-hydroxy-5-iodoquinoline and 8-hydroxy- 7
-Iodo-5-isocyanatoquinoline. Similar {111} grain growth modifiers, such as the various 5-iodobenz disclosed in Maskasky US Pat. No. 5,298,387, the disclosures of which are incorporated herein by reference. Similar utility is expected for oxazolium compounds and various benzimidazolium compounds disclosed in Maskasky US Pat. No. 5,298,388, the disclosures of which are incorporated herein by reference. To be done.

1- (3-acetamidophenyl) -5-
Because mercaptotetrazole (APMT) is a widely used and preferred antifoggant and stabilizer for high chloride photographic emulsions, the use of APMT as a grain growth modifier in the practice of this invention is very beneficial. . Thus, the grain growth modifier can provide a second photographic function after the grains have been formed. AMPT is useful {110}
It is a specific example of a thionamide compound known to be a particle growth modifier. A common feature of these compounds is the thioamide, -NH-C (S)-group. Thioamide compounds and their use as grain growth modifiers are described in Ma
skasky's "Photo 7 different crystal forms of silver halide (Th
e SevenDifferent Kind of Crystal Forms of Photogra
phic Silver Halides) ”, Journal of Imaging Scienc
e, No. 6, November and December 1986, pp. 247-254.

In preparing a high chloride {111} tabular grain emulsion, at least both of the major surfaces of each {111} tabular grain have a grain growth modifier adsorbed thereto, It is a disadvantage to use adsorbed particle growth modifiers for creation and storage. Effective grain growth modifiers involved in this patent application are non- {1
Adsorb on the plane of the {100} tabular grains on the 00 plane. That is, the non- {100} edge planes appear because they are the crystal planes where the effective grain growth modifier exhibits adsorption preference. Therefore, grain growth modifiers exhibit relatively low affinity for the {100} major faces of tabular grains,
The {100} major surface is free to accept other photographic additives. Therefore, high chloride emulsions, including {100} tabular grain emulsions prepared with non- {100} grain edges, by using adsorbed grain growth modifiers, have a
Even when two emulsions are prepared with the same grain growth modifier, they show significant advantages over {111} tabular grain emulsions.

Thionamide compound 2-mercaptopyridine and related compounds 5-carboxy-4-hydroxy-6
The following examples demonstrate that -methyl-2-methylthio-1,3,3a, 7-tetraazaindene failed to produce tabular grains with grain surfaces that are in different atomic planes. . Maskasky U.S. Pat. Nos. 4,400,463 and 4,713,323; Jones et al. U.S. Pat.
5,176,991, Maskasky U.S. Pat.No. 5,183,239
And the first and most widely described grain growth modifier for precipitating high chloride {111} tabular grains, as illustrated by Verbeek and EPO 0 481 133. Similar failures are reported in the examples below for adenine. Unfortunately, instead of selectively producing non- {100} crystal faces at the edges of the grains, these known grain growth modifiers cause silver chloride to be deposited over the entire outer surface of the grain, which is Crumpled grain surfaces of the type disclosed in U.S. Pat. No. 4,643,966 are produced, with further edges protruding. Therefore, the purpose of obtaining tabular grains having planes having different crystal plane orientations has not been realized.

Non- {1} while preserving the {100} main grain surface.
The success reported in the examples that the creation of the 00} edge facets was achieved was obtained by balancing such that silver and chloride precipitation occurred closer to equilibrium. That is, in the following reaction,

[Chemical 4] Although the driving force is to the right, the higher particle displacement reaction energy in the edge region compared to the major surface allows the edge region to act as a preferred acceptor site for deposition.

In addition to the emulsion grain characteristics specifically discussed, the emulsions of this invention and photographic elements in which they can be used are Mask
asky US Pat. Nos. 5,292,930 and 5,292,632; House et al. US Pat. No. 5,320,938; Sz
ajewski et al. U.S. Patents 5,310,635 and 5,35
6,764; and U.S. Pat. No. 5,314, Brust et al.
Features of the {100} tabular grain emulsions disclosed in 798, which are cited above and incorporated herein by reference. The features of photographic elements in which the emulsions of this invention can be used and the uses of such photographic elements are described in Research Disclosure, Vol. 365, September 1994, Item.
More detailed by 36544. Research Disclosure by Kenneth Maso
n Publications Ltd, Dudley House, 12 North St., Em
Published by sworth, Hampshire P010 7DQ, England.

[0037]

EXAMPLES The invention will be understood by the following specific examples. The acronym DW was used to indicate distilled water. Speed is in relative log units (ie 30 units =
0.3 log E, where E is the exposure dose (lux-sec, lux-sec
onds)). Examples 1-4 These examples demonstrate the effectiveness of thiocyanates to produce non- {100} grain faces on high chloride tabular grains bounded by {100} major faces. It is shown.

Example 1 Emulsion A (control) Six kinds of solutions were prepared as follows. Solution 1 Gelatin (bone) 75 g NaCl 2.88 g KI 0.44 g DW 4300 g Solution 2 NaCl 397.4 g DW up to total volume 1700 mL solution 3 NaCl 4.3 g DW 6500 g solution 4 AgNO ₃ 1155 g DW up to total volume 1700 mL solution 5 Gelatin (phthalated) 200g DW 1500g Solution 6 Gelatin (bone) 130g DW 1500g

Solution 1 was placed in a reaction vessel equipped with a stirrer. The pH was adjusted to 6.5 and the temperature was raised to 55 ° C. While vigorously stirring the contents of the reaction vessel, Solution 2 and Solution 4
Was added at 45 mL / min over 1 minute. Solution 3 was then added to the mixture. Next, to solution 4 which was not added to the reaction vessel, 0.066 mg / Ag of mercuric chloride antifoggant was added.
Added in an amount of 1 mol. The pH was adjusted to 6.5 and the pCl was adjusted to 1.91 while maintaining the pH at 6.5. The mixture was held for 5 minutes. Following this hold, Solution 2 and Solution 4 were each added simultaneously at a linearly accelerated rate of 15 mL / min to 37 mL / min for 56 minutes, maintaining pCl at 1.91. The mixture was then cooled to 40 ° C., Solution 5 was added with stirring and stirring was continued for 5 minutes. The pH was then adjusted to 3.8 and the gel was allowed to settle. At the same time, the temperature was lowered to 15 ° C, and then the liquid layer was decanted. The consumed capacity was restored by DW. Adjust pH to 4.5, and mix at 20 ° C for 20
The pH was adjusted to 3.8 after holding for a minute. The precipitation and decantation steps were repeated. Add solution 6,
The pH and pCl were adjusted to 5.6 and 1.6, respectively. Examination of the grain structure has shown that> 70 percent of the total grain projected area is accounted for by {100} tabular grains.
The tabular grains did not have any identifiable non- {100} faces. {100} tabular grains have an average thickness of 0.14
μm and mean equivalent circular diameter (ECD) 1.4 μm.

Emulsion B (Example) After introducing 80% of total silver into the reaction vessel, the precipitation was stopped, and a solution containing 3.0 g of NaSCN in 20 cc (cm ³ ) of DW was placed in the reaction vessel over 2 minutes. Emulsion B was prepared like Emulsion A, except that it was added. Grain structure studies show that> 70 percent total grain projected area is at least 1
{100} containing two identifiable non- {100} edge faces
It was shown to be occupied by tabular grains having major faces. The tabular grains had a mean thickness of 0.13 µm and a mean equivalent circular diameter (ECD) of 1.4 µm.

Finishing, Coating and Sensitometry Add 1 mol% NaBr based on the amount of silver, followed by 5
Hold for minutes, spectral sensitizing dye anhydro-9-ethyl-
5,5'-diphenyl-3,3'-di (3-sulfobutyl) oxacarbocyanine hydroxide, monosodium salt (SS-1) was added at 0.7 mmol / Ag 1 mol, followed by a 10 minute hold and Na ₂ S ₂ O ₃ .5H ₂ O was added at 2 mg / Ag 1 mol and KAuCl ₄ at 1 mg / Ag 1 mol, followed by heating for 10 minutes at 60 ° C., cooling to 40 ° C. and after the heating step 1- ( 3-acetamidophenyl) -5-mercaptotetrazole (APMT) 1
Emulsion A and Emulsion B were finished by adding 00 mg / mol. It is noted that APMT cannot act as a grain growth modifier because APMT is not added until after the emulsion grains have been formed. The finished emulsion was coated on a photographic film support at a Ag of 5.38 mg / dm ² with the magenta dye-forming coupler MC-1 (4.84 mg / dm ² ).
The coating was overcoated with gel and cured.

[0042]

[Chemical 5]

The coatings were exposed for 1/50 seconds in simulated daylight through a calibrated test subject, and British Journa
Photographic processing was carried out with the Kodak Flexicolor ™ C-41 Color Negative Process described in the I of Photography Annual of 1988, pp.196-198. The sensitometric results are summarized in Table I. Speed was measured at the intersection of extrapolated midscale contrast (γ) vs. minimum density (D _min ).

[0044]

[Table 1] Emulsion B, which meets the requirements of the invention, showed a significant reduction in contrast and a slight increase in speed compared to the control emulsion.

Example 2 Emulsion C (control) Six solutions were prepared as follows. Solution 1 Gelatin (bone) 52 g NaCl 0.96 g KI 0.18 g DW 2850 g Solution 2 NaCl 257.1 g DW up to total volume 1100 mL Solution 3 NaCl 2.1 g DW 6500 g Solution 4 AgNO ₃ 747.4 g DW up to total volume 1100 mL Solution 5 Gelatin (phthalated) 133g DW 500g Solution 6 Gelatin (bone) 87g DW 500g

Solution 1 was placed in a reaction vessel equipped with a stirrer. The pH was adjusted to 6.5 and the temperature was raised to 55 ° C. While vigorously stirring the contents of the reaction vessel, Solution 2 and Solution 4
Was added at 130 mL / min for 1.5 minutes. Solution 3 was then added to the mixture. Raise the temperature of the reaction vessel to 62 ° C,
Adjust pH to 6.5 and adjust pCl to 1.91 while maintaining pH at 6.5.
Adjusted to. The mixture was held for 5 minutes. Following this holding, solution 2 and solution 4 were each simultaneously applied at 10 mL / min to 24 mL.
PCl was added for 56 minutes at a linearly accelerated rate per minute while maintaining pCl at 1.91. The mixture was then cooled to 40 ° C., Solution 5 was added and stirred for 5 minutes. Then adjust the pH
Adjusted to 3.8 and allowed the gel to settle. At the same time, the temperature was lowered to 15 ° C, and then the liquid layer was decanted. The consumed capacity was restored by DW. The pH was adjusted to 4.5 and the mixture was kept at 40 ° C for 20 minutes before adjusting the pH to 3.8,
Then, the precipitation step and the decantation step were repeated. Solution 6 was added and the pH and pCl were adjusted to 5.6 and 1.6, respectively. Examination of the grain structure has shown that> 80 percent of the total grain projected area is accounted for by {100} tabular grains. The tabular grains did not have any identifiable non- {100} faces. The {100} tabular grains have an average thickness of 0.14 μm and an average equivalent circular diameter (EC
D) It had 1.3 μm.

Emulsion D (Example) After introducing 80% of the total silver into the reaction vessel, the precipitation was stopped, and a solution containing 1.6 g of NaSCN in 20 cc (cm ³ ) of DW was placed in the reaction vessel for 2 minutes. Emulsion D was prepared like Emulsion C except that it was added. Grain structure studies show that> 80 percent total grain projected area is at least 1.
{100} containing two identifiable non- {100} edge faces
It was shown to be occupied by tabular grains having major faces. The tabular grains had a mean thickness of 0.14 µm and a mean equivalent circular diameter (ECD) of 1.4 µm.

Example 3 Emulsion E (Control) Six solutions were prepared as follows. Solution 1 Gelatin (bone) 25 g NaCl 0.96 g KI 0.18 g DW 2850 g Solution 2 NaCl 257.1 g Total volume DW 1100 mL Solution 3 NaCl 2.1 g DW 6500 g Solution 4 AgNO ₃ 747.4 g Total volume DW 1100 mL Solution 5 Gelatin (phthalated) 133g DW 500g Solution 6 Gelatin (bone) 87g DW 500g

Solution 1 was placed in a reaction vessel equipped with a stirrer. The pH was adjusted to 6.5 and the temperature was raised to 55 ° C. While vigorously stirring the contents of the reaction vessel, Solution 2 and Solution 4
Was added at 130 mL / min for 1.5 minutes. Solution 3 was then added to the mixture. Then, to the solution 4 which was not added to the reaction vessel, 0.11 mg / A of a mercuric chloride antifoggant was added.
It was added in an amount of 1 mol of g. Raise the temperature of the reaction vessel to 62 ° C and adjust the pH to 6.5 while maintaining the pH at 6.5.
The pCl was adjusted to 1.91. The mixture was held for 5 minutes. Following this hold, solution 2 and solution 4 were each added simultaneously to 10 mL.
/ Min ~ 24 mL / min, linearly accelerated speed for 56 minutes, pC
l was added maintaining 1.91. Then the mixture at 40 ° C
Cool to room temperature, add solution 5 and add the contents of the reaction vessel to 5
Stir for minutes. The pH was then adjusted to 3.8 and the gel was allowed to settle. At the same time, the temperature was lowered to 15 ° C, and then the liquid layer was decanted. The consumed capacity was restored by DW.
The pH was adjusted to 4.5 and the mixture was kept at 40 ° C. for 20 minutes before adjusting the pH to 3.8. The precipitation and decantation steps were repeated. Add solution 6, add pH and pC
l was adjusted to 5.6 and 1.6 respectively. Examination of the grain structure has shown that> 70 percent of the total grain projected area is accounted for by {100} tabular grains. The tabular grains did not have any identifiable non- {100} faces. The {100} tabular grains had a mean thickness of 0.14 µm and a mean equivalent circular diameter (ECD) of 1.5 µm.

Emulsion F (Example) After introducing 80% of the total silver into the reaction vessel, the precipitation was stopped, and a solution containing 1.6 g of NaSCN in 20 cc (cm ³ ) of DW was placed in the reaction vessel for 2 minutes. Emulsion F was prepared like Emulsion E, except that it was added. Grain structure studies show that> 65 percent of total grain projected area is at least 1.
{100} containing two identifiable non- {100} edge faces
It was shown to be occupied by tabular grains having major faces. The tabular grains had a mean thickness of 0.14 µm and a mean equivalent circular diameter (ECD) of 1.4 µm.

Emulsion G (Example) After introducing 60% of total silver into the reaction vessel, the precipitation was stopped, and a solution containing 3.24 g of NaSCN in 20 cc (cm ³ ) of DW was placed in the reaction vessel for 2 minutes. Emulsion G was prepared like Emulsion E, except that it was added. Grain structure studies show that> 60 percent total grain projected area is at least 1.
{100} containing two identifiable non- {100} edge faces
It was shown to be occupied by tabular grains having major faces. The tabular grains had a mean thickness of 0.13 µm and a mean equivalent circular diameter (ECD) of 1.38 µm. A projection electron micrograph of the particle replica is shown in FIG.

Emulsion H (Example) After introducing 40% of the total silver into the reaction vessel, the precipitation was stopped, and a solution containing 3.24 g of NaSCN in 20 cc (cm ³ ) of DW was placed in the reaction vessel for 2 minutes. Emulsion H was prepared as Emulsion E except that all were added. A study of grain structure shows that> 70 percent of the total grain projected area contains at least one identifiable non- {100} edge surface {10.
It was shown to be occupied by tabular grains having a {0} major surface. The tabular grains had a mean thickness of 0.13 µm and a mean equivalent circular diameter (ECD) of 1.09 µm.

Finishing, Coating and Sensitometry Emulsions E and F were prepared with 4,4'-diphenyldisulfide diacetanilide antifoggant, 6 mg / Ag each.
Finished with 1 mol and 4 mg / Ag 1 mol. An amount of 0.25 mol% sodium bromide based on the amount of silver was added followed by a 5 minute hold. Spectral sensitizing dye Anhydro 3'-methyl-4'-phenyl-1- (3-sulfopropyl) naphtho [1,2-d] thiazolothiazolocyanine hydroxide (SS-2) 0.8 mmol / Ag 1 mol was added. And then held for 10 minutes. Then Na ₂ S ₂ O ₃
5H ₂ O 2.8 mg / Ag 1 mol and KAuCl ₄
Chemically sensitized by adding 1.4 mg / Ag 1 mol,
And it heated at 60 degreeC for 10 minutes. After the heating process, APM
The antifoggant was added at 100 mg / Ag 1 mol. A finished emulsion (deposition Ag 9.65 mg / dm ² ) was added to a mixture of yellow dye-forming couplers YC-1 and YC-2, respectively.
It was coated with a molar ratio of 1: 1 and a total coverage of 9.65 mg / dm ² . The coating was overcoated with gel and cured.

[0054]

[Chemical 6]

The coating is exposed for 1/50 second in simulated daylight through a calibrated test subject, and Kodak Flexicol
or (trademark) C-41 color negative process 3 '
15 ″ photograph processed. Sensitometric results are summarized in Table II. Speed measurements are the same as those reported in Table I.

[0056]

[Table 2] Emulsion F, which meets the requirements of the invention, showed significantly reduced fog and contrast compared to the control emulsion. Also, the speed was slightly reduced.

Example 4 Emulsion J (control) Six solutions were prepared as follows. Solution 1 Gelatin (bone) 25 g NaCl 0.96 g KI 0.18 g DW 2824 g Solution 2 NaCl 284 g DW 1215 mL solution up to total volume 3 NaCl 2.1 g DW 6488 g solution 4 AgNO ₃ 756.6 g DW 1069 mL solution up to total volume 5 Gelatin (phthalated) 133 g DW 500 g Solution 6 DW 500 g Gelatin (bone) 90 g

Solution 1 was placed in a reaction vessel equipped with a stirrer. The pH was adjusted to 6.5 and the temperature was raised to 55 ° C. While vigorously stirring the contents of the reaction vessel, Solution 2 and Solution 4
Was added at 90 mL / min over 0.67 minutes. Then solution 3
Was added to the mixture. Next, to solution 4 not added to the reaction vessel, 0.10 mg / Ag of mercuric chloride antifoggant was added.
Added in an amount of 1 mol. The temperature of the reaction vessel was raised to 62 ° C., the pH was adjusted to 6.5 and the pCl 2 was adjusted to 2.4. The mixture was held for 5 minutes. Following this hold, solution 2 and solution 4 were each maintained simultaneously at a linearly accelerated rate of 10 mL / min to 24 mL / min for 56 minutes at a pCl of 2.4, and
Add while maintaining pH at 6.5. Then the mixture at 40 ° C
Solution 5 was added, followed by stirring for 5 minutes.
The pH was then adjusted to 3.8 and the gel was allowed to settle. The liquid layer was decanted and the consumed volume was restored with DW. The mixture was held until the temperature returned to 40 ° C. Then
Adjust the pH to 4.2, hold the mixture for 5 minutes and then adjust the pH to 3.
Adjusted to 8. Then, the precipitation step and the decantation step were repeated. Solution 6 was added and the pH and pCl were adjusted to 5.7 and 1.6, respectively. Investigation of particle structure
It was shown that> 80 percent of the total grain projected area was occupied by {100} tabular grains. The tabular grains did not have any identifiable non- {100} faces.
The {100} tabular grains had a mean thickness of 0.14 µm and a mean equivalent circular diameter (ECD) of 1.48 µm.

Emulsion K (Example) After introducing 60% of the total silver into the reaction vessel, the precipitation was stopped, and a solution containing 3.24 g of NaSCN in 25 mL of DW was added to the reaction vessel over 2 minutes. Emulsion K was prepared as Emulsion J except. > 80 for particle structure investigation
It has been shown that the percent total grain projected area is accounted for by tabular grains having {100} major faces that include at least one identifiable non- {100} edge face. The tabular grains have an average thickness of 0.16 μm and an average equivalent circular diameter (EC
D) had 1.28 μm.

Finishing, Coating and Sensitometry Addition of 1 mol% NaBr, based on the amount of silver, followed by a 5 minute hold and the spectral sensitizing dye anhydro-5-chloro-
9-Ethyl-5'-phenyl-3 '-(3-sulfobutyl) -3- (3-sulfopropyl) oxacarbocyanine hydroxide, sodium salt (SS-3) and anhydro-11-ethyl-1,1'. -Bis (3-sulfopropyl) naphtho [1,2-d] oxacarbocyanine hydroxide sodium salt (SS-4) (SS-
Emulsions J and K were finished by adding a mixture of 3: SS-4 molar ratio 3: 1) at 0.7 mmol / Ag 1 mol followed by a 20 minute hold. Chemical sensitizer Na ₂ S
₂ O ₃ · 5H ₂ O (2 mg / Ag 1 mol) and KAuC
l ₄ (1 mg / Ag 1 mol) was added, followed by 10 minutes at 60 ° C.
Heated at. After the heating step, APMT (100 mg / mol) was added. Finished emulsion (Ag8.55mg / dm ² )
Coated with cyan dye-forming coupler CC-1 (10.76 mg / dm ² ). The coating was overcoated with gel and cured.

[0061]

[Chemical 7]

A sample of the coating was exposed for 1/50 second in simulated daylight through a calibrated test subject, and Kodak Fl
Exicolor ™ C-41 Color Negative Process 60 ″, 90 ″ or 120 ″ photograph processed. Sensitometric results are summarized in Table III. Speed measurements are the same as those reported in Table I. The speed column in Table III reports the speed measured after processing for 90 seconds.The process sensitivity is 60 times the processing time.
It is the speed difference between seconds and 120 seconds.

[0063]

[Table 3] Emulsion K satisfying the requirements of the invention is
It showed high speed and low contrast. Emulsion K
An important additional advantage of the was its low processing sensitivity.

Example 5 This example uses thiocyanate and iodide used in the same precipitation method to produce non- {100} grain surfaces on high chloride tabular grains having {100} major faces. It specifically shows the effectiveness of. Emulsion L (Example) Eight emulsions were prepared as follows. Solution 1 Gelatin (oxidized) 195 g NaCl 3.0 g DW 4369 g Solution 2 NaCl 420.4 g DW up to total volume 1799 mL Solution 3 NaCl 2.25 g KI 0.60 g DW 8983 g Solution 4 AgNO ₃ 1211.8 g DW up to total volume 1726 mL Solution 5 NaSCN 0.82 g DW 25 g Solution 6 KI 5.93 g DW 298 g Solution 7 Gelatin (phthalated) 215 g DW 1500 g Solution 8 Gelatin (oxidized) ^* 81 g DW 1500 g * Most methionine was eliminated by treatment with hydrogen peroxide.

Solution 1 was placed in a reaction vessel equipped with a stirrer. The pH was adjusted to 5.7 and the temperature was adjusted to 35 ° C. Solution 2 and Solution 4 at 22.5 mL / min while stirring the contents of the reaction vessel
Added over 1.28 minutes. Solution 3 was then added to the mixture and the pH was adjusted to 5.7. The mixture was held for 8 minutes. Then, a mercuric chloride antifoggant was added to Solution 4 not added to the reaction vessel in an amount of 0.08 mg / Ag 1 mol. Following this hold, solution 4 from 12 mL / min to 12.1 mL
/ Min while linearly accelerating for 2 minutes,
Solution 2 was added at a constant rate of 9.8 mL / min and the pCl was adjusted to 2.6
I raised it to. In addition, the temperature was increased linearly from 35 ℃ to 36.5 ℃. Then, Solution 2 and Solution 4 are each added simultaneously 1
A linearly accelerated rate of 2.1 mL / min to 15 mL / min was added for 38 minutes, maintaining pCl 2 at 2.6. Also, set the temperature to 3
The temperature was increased linearly from 6.5 ° C to 65 ° C. The mixture was held for 20 minutes. Following this hold, Solution 2 is 16.5 mL / min -1
The pCl was lowered to 2.6 by adding linearly accelerated rate of 6.2 mL / min and solution 4 at a linearly accelerated rate of 15 mL / min to 17.7 mL / min. Solution 2 and Solution 4 were then added simultaneously at a linearly accelerated rate of 17.7 mL / min to 27.6 mL / min for 18.5 minutes, maintaining pCl 2 at 2.6. Add Solution 5 to the reaction vessel (at once),
Hold for 5 minutes. Then, Solution 2 and Solution 4 were simultaneously accelerated linearly at a rate of 27.6 mL / min to 36.5 mL / min.
Addition of pCl 2 at 2.6 for 16.8 minutes. Solution 6 was then added to the mixture and held for 10 minutes. Following this hold, solution 2 and solution 4 were simultaneously added at 36.5 mL /
Min-39 mL / min linearly accelerated speed for 4.7 min, pC
l was added while maintaining 2.6. The mixture was held for 30 minutes. Following this hold, the mixture was cooled to 40 ° C. and Solution 7 was added and stirred for 5 minutes. Then adjust the pH
Adjusted to 3.8 and allowed the gel to settle. The liquid layer was decanted and the consumed volume was restored with DW. Temperature is 40
The mixture was held until it returned to ° C. The pH was then adjusted to 4.2 and the mixture was held for 5 minutes before adjusting the pH to 3.8. Then, the precipitation step and the decantation step were repeated. Add solution 8 and adjust pH and pCl to 5.7
And adjusted to 1.6.

A study of grain structure shows that> 65 percent of the total grain projected area is at least one identifiable non- {10
It was shown to be occupied by tabular grains having {100} major faces including 0} edge faces. Tabular grains have average thickness
It had a 0.19 μm and a mean equivalent circular diameter (ECD) of 1.66 μm. Finishing, Coating and Sensitometry Emulsion L was finished, coated and tested for sensitometry in the same manner as Emulsion J. The behavior of Emulsions J and L when processed for 120 seconds is compared in Table IV.

[0067]

[Table 4] Emulsion L, which meets the requirements of the present invention, showed significantly lower contrast than the control emulsion. The speed of emulsion L is
Somewhat lower than that of the control emulsion.

Examples 6-9 These examples demonstrate the effectiveness of iodide in producing non- {100} grain faces on high chloride tabular grains having {100} major faces. Is. Example 6 This example demonstrates the addition of iodide (at one time) at a later stage of high chloride {100} tabular grain precipitation to produce non- {100} square faces on the tabular grains. It is shown concretely. Emulsion M 12 L of reaction vessel was charged with 3.1 L of distilled water containing 2 g of NaCl and 130 g of oxidized gelatin, pH 5.7 and temperature of 35 ° C.
Adjusted to. During the precipitation process, the contents of the reaction vessel were vigorously stirred. To the first introduced solution, 1M AgNO ₃ solution and 1M NaCl solution were respectively added at a rate of 42 mL / min.
Each was added simultaneously for 1.6 minutes. 2.39 pCl 2 during nucleation
Maintained at.

Then, 5.8 L of distilled water, 190 g of 0.012
MKI solution and a solution containing 1.5 g of NaCl were added. The solution was held for 5 minutes. After maintaining, the temperature of the mixture is raised from 35 ° C to 50 ° C in 20 minutes and at the same time 4
10 mL / M AgNO ₃ solution and 4M NaCl solution
Each was added in minutes to reduce the pCl from 2.39 to 2.24. Further, the temperature is raised from 50 ° C. to 65 ° C. in 20 minutes, and during this period, AgNO ₃ solution and NaCl solution are added at 10 mL / min.
Add pCl at a linearly accelerated rate of 15 mL / min.
It was reduced linearly from 2.2 to 1.82. After this treatment, the medium was kept at 65 ° C for 15 minutes. After this maintenance, AgNO ₃
Solution and addition of NaCl solution from 10 mL / min to 28.7 mL /
Restarted for 45 minutes at a linearly accelerated speed of minutes. Of emulsion
pCl was maintained at 1.82 during the final growth period. 65 reaction vessels
Hold at ℃ for an additional 30 minutes.

After this maintenance, 200 mL containing 4.96 g of KI
Solution was added and the emulsion was held for 10 minutes. Final particle growth was done with 10 mL of 4M AgNO ₃ and NaCl solution.
Complete by adding 13 min / min, pCl 1.
Adjusted to 82. The resulting emulsion had a mean grain size of 1.0 μm and a mean grain thickness of 0.14 μm. Tabular grains with {100} major faces and visually identifiable non- {100} grain faces at their corners accounted for> 84 percent of total grain projected area.

Example 7 In this example, iodide was added (at once) at a later stage of high chloride {100} tabular grain precipitation to produce non- {100} square faces on the tabular grains. It shows inflow concretely. Emulsion N 12 L of reaction vessel was charged with 3.1 L of distilled water containing 2 g of NaCl and 130 g of oxidized gelatin, pH 5.7, temperature of 35 ° C.
Adjusted to. During the precipitation process, the contents of the reaction vessel were vigorously stirred. To the first introduced solution, 1M AgNO ₃ solution and 1M NaCl solution were added at a rate of 45 mL / min each.
Each was added simultaneously for 1.6 minutes. 2.39 pCl 2 during nucleation
Maintained at.

Then 5.8 L of distilled water, 190 g of 0.012
MKI solution and a solution containing 1.5 g of NaCl were added. The solution was held for 5 minutes. After maintaining, raise the temperature of the mixture from 35 ° C to 50 ° C in 20 minutes and
10 mL / M AgNO ₃ solution and 4M NaCl solution
Each was added in minutes to reduce the pCl from 2.39 to 2.24. Further, the temperature is raised from 50 ° C. to 65 ° C. in 20 minutes, and during this period, AgNO ₃ solution and NaCl solution are added at 10 mL / min.
Add pCl at a linearly accelerated rate of 15 mL / min.
It was reduced linearly from 2.2 to 1.82. After this treatment, the medium was kept at 65 ° C for 15 minutes. After this maintenance, AgNO ₃
Solution and NaCl solution addition was resumed for 30 minutes at a linearly accelerated rate of 10 mL / min to 22 mL / min. Emulsion p
Cl was maintained at 1.82 during the final growth period. 65 ℃ reaction vessel
And kept for another 30 minutes.

After this maintenance, 200 mL containing 4.96 g of KI
Solution was added and the emulsion was held for 10 minutes. Final particle growth was completed by adding 4M AgNO ₃ solution and 0.12M KI solution at 10 mL / min each for 10 minutes to adjust the pCl to 1.82. The resulting emulsion had a mean grain size of 1.1 μm and a mean grain thickness of 0.13 μm. {10
0} Non- {1 that can be visually confirmed on the major surfaces and their corners
Tabular grains having a 00} grain face accounted for> 70 percent of total grain projected area.

Example 8 In this example, iodide was added (at once) at a later stage of high chloride {100} tabular grain precipitation to produce non- {100} square faces on the tabular grains. It specifically shows what to do. Emulsion O 12 L of a reaction vessel was charged with 3.1 L of distilled water containing 2 g of NaCl and 130 g of oxidized gelatin, pH 5.7 and temperature of 35 ° C.
Adjusted to. During the precipitation process, the contents of the reaction vessel were vigorously stirred. To the first introduced solution, 1M AgNO ₃ solution and 1M NaCl solution were respectively added at a rate of 52 mL / min.
Each was added simultaneously for 1.6 minutes. 2.39 pCl 2 during nucleation
Maintained at.

Then 5.8 L of distilled water, 190 g of 0.012
M solution and a solution containing 1.5 g of NaCl were added. The solution was held for 5 minutes. After maintaining, the temperature of the mixture is raised from 35 ° C to 65 ° C in 30 minutes and at the same time 1M
AgNO ₃ solution and 1M NaCl solution were added at 10 mL / min each to reduce the pCl from 2.39 to 1.82. After this treatment, the medium was kept at 65 ° C for 60 minutes. After this maintenance, 4.96
200 mL of a solution containing g of KI was added and the emulsion was added to 10
Hold for minutes. Final particle growth was completed by adding 1 M AgNO ₃ solution and 1 M NaCl solution at 10 mL / min each for 10 minutes to adjust the pCl to 1.82. The resulting emulsion had an average grain size of 1.04 μm and an average grain thickness of 0.
It had a thickness of 07 μm. Tabular grains with {100} major faces and visually identifiable non- {100} grain faces at their corners accounted for> 90 percent of total grain projected area.

Example 9 This example was prepared to produce high chloride {100} tabular grains having at least one non- {100} grain face.
Illustrating the inflow of iodide in the late stage of high chloride {100} tabular grain precipitation. Emulsion P 18 L of a reaction vessel was charged with 4.368 L of distilled water containing 3.0 g of NaCl and 195.0 g of oxidized gelatin and adjusted to pH 5.7 and temperature of 35 ° C. During the precipitation process, the contents of the reaction vessel were vigorously stirred. While maintaining pCl at 1.97, the first introduced solution was 1 M AgNO ₃ solution at a rate of 78 mL / min and 4 M NaCl solution at a rate of 20 mL / min.
Simultaneously added for 1.6 minutes.

Then 9.285 L of a solution containing 2.25 g NaCl and 0.65 g KI was added to the reaction vessel. The solution was held for 5 minutes. After maintaining, the temperature of the solution was raised from 35 ° C to 36.5 ° C in 2 minutes and the pCl was raised from 2.19 to 2.35 while at the same time 0.08 mg of mercuric chloride per mol of silver nitrate.
A 4M AgNO ₃ solution containing 4M and a 4M NaCl solution were introduced into the reaction vessel at 15 mL / min. 4M Ag containing 0.08 mg mercuric chloride per mole silver nitrate in the next 18 minutes
NO ₃ solution and 4M NaCl solution were added to the reaction vessel at 15 mL / min while simultaneously decreasing the pCl 2 linearly from 2.35 to 2.21 and raising the temperature from 36.5 ° C to 50 ° C. Continue
Mercury chloride 0.08 mg per mol of silver nitrate in 20 minutes
Solution of 4M AgNO ₃ and 4M NaCl solution at a linearly accelerated rate of 15 mL / min to 22.5 mL / min to linearly reduce pCl from 2.21 to 1.72 and the temperature at 50 ° C. The temperature was linearly increased from to 70 ° C. After this treatment, the medium was kept at 70 ° C for 15 minutes.

After this maintenance, a 4M AgNO ₃ solution containing 0.08 mg of mercuric chloride per mol of silver nitrate and 4M
The NaCl solution was added at a linearly accelerated rate of 15 mL / min to 38.6 mL / min for 37.4 minutes while maintaining the pCl at 1.72. After this treatment, the medium was kept at 70 ° C. for 30 minutes. Final growth was completed by adding a 4M AgNO ₃ solution containing 0.08 mg mercuric chloride per mole silver nitrate, and 3.72 M NaCl and 0.28 M KI salt solution were added to the reaction vessel at 20 mL / min each. And p
Cl was maintained at 1.72. The resulting emulsion has an average grain size of about
It had a thickness of 1.6 μm and an average grain thickness of about 0.16 μm. {10
0} Non- {1 that can be visually confirmed on the major surfaces and their corners
Tabular grains having a {00} grain face accounted for> 50 percent of the total grain projected area.

Example 10 This example demonstrates a high chloride {100} tabular grain emulsion with edge modification to provide a non- {100} grain surface provided by an adsorbed organic grain growth modifier. The preparation method of is specifically shown. Host Emulsion HA House A high chloride {100} tabular grain emulsion was prepared using the method described in US Pat. No. 5,320,938 et al. The tabular grains had a mean equivalent circular diameter of 2.5 µm and a mean grain thickness of 0.16 µm. There was no visually recognizable non- {100} grain surface. Host Emulsion H-B The high chloride {100} tabular grain emulsion was replaced with host emulsion H-
Prepared as in A. Tabular grains have an average equivalent circular diameter
It had a thickness of 1.5 μm and a mean grain thickness of 0.13 μm. There was no visually recognizable non- {100} grain surface.

Emulsion Q High chloride {100} tabular grains with {111} angled faces, 2% bone, overformed by 13 mol% with 4,5,6-triaminopyrimidine as grain growth modifier. 400 mL of a solution of gelatin, 2.0 mM 4,5,6-triaminopyrimidine and 0.040M NaCl (pH
6.0 and 40 ° C.) containing 0.04 mol of host emulsion H-B in a stirred reaction vessel, 3.0 mL of 2M Ag
NO ₃ solution was added at 1.0 mL / min and 2.5 M Na
The Cl solution was added at the rate required to maintain a constant pCl 1.50. The resulting emulsion was examined by scanning electron microscopy. The total grain projected area above 60 percent was occupied by high chloride {100} tabular grains with two bevels adjacent each corner. None of the tabular grains protruding from the {100} main surface were observed. Examination of the particle angle at a suitable angle confirms that the angle between the two tilted angle faces is that they are {111} faces.
It was revealed to be 109 °. (By this confirmation,
The orientation of the crystal lattice of the grain is determined relative to its shape, so that the orientation of the edge planes perpendicular to the {100} major faces, as well as the faces 306-312 of the grain 300, is {110. It was confirmed to be the {100} plane rather than the} plane. Therefore, the particles were substantially similar to the ideal particle structure 300. )

Emulsion R High chloride {100} tabular grains with {111} square faces, 2% bone, overformed by 23 mol% with 2,4,6-triiodophenol as grain growth modifier. 400 ml of a solution of gelatin, 0.2 mM 2,4,6-triiodophenol, 0.040 M NaCl and 0.20 M sodium acetate containing 0.04 mol of host emulsion H-B in a stirred reaction vessel in, it was added 4M AgNO ₃ solution 3.0mL at 1.0 mL / min, and a 4.5 M NaCl solution was added at a rate needed to maintain a constant pCl 1.42. The resulting emulsion was examined by scanning electron microscopy. It is a high chloride {100} with two bevels adjoining each corner of the tabular grains.
It is composed of tabular grains and has a tabular grain size of {10
Nothing protruding from the 0} main surface was observed. Examination of the particle angle at a suitable angle confirms that the angle between the two corner faces is that they are {111} faces.
It was revealed to be 109 °.

Emulsion S High chloride {100} with {110} corners and edge faces, overformed by 23 mol% with 1- (3-acetamidophenyl) -5-mercaptotetrazole as grain growth modifier. Tabular grains This emulsion was prepared in the same manner as Emulsion R except that 0.30 mM 1- (3-acetamidophenyl) -5-mercaptotetrazole was added to the reaction vessel and no triiodophenol was added at all. did. Obtained {10
The 0} tabular grains had {110} faces along their edges and corners; 12 {110} faces per grain. Therefore, the tabular grains were equivalent to the ideal grain 200.

Emulsion T (Failure) 23 mol% overformed, high chloride non- {100} tabular grains with {110} angles and edge faces. This emulsion was charged with 0.20 mM 5-carboxy-4 in a reaction vessel. −
Hydroxy-6-methyl-2-methylthio-1,3,3
An emulsion R was prepared in the same manner as Emulsion R except that a, 7-tetraazaindene was added and triiodophenol was not added at all. Square tabular grains were observed. The edges and corners of square tabular grains are 12 {1
10} plane. However, {10
0} main surface was not confirmed at all. The major surface of the particles is clearly crumpled, which is described by Maskasky U.S. Pat.
It was representative of the grain surface formed by non- {100} cone precipitation of the type described in 43,966. This demonstrated the ineffectiveness of the tetraazaindene grain growth modifier for producing emulsions that met the requirements of the present invention.

Emulsion U (Failure) 23 mol% overformed, high chloride non- {100} tabular grains with {110} angles and edge faces This example was prepared in a reaction vessel with 0.30 mM 2-mercaptopyridine. Was prepared in the same manner as Emulsion R, except that triiodophenol was not added at all. The resulting rectangular tabular grains did not contain major {100} faces. The grains exhibited surface characteristics similar to those described for Emulsion T.

Emulsion V (Failure) 23 mol% overformed, high chloride non- {100} tabular grains with {110} angles and edge faces 2% bone gelatin, 3.9 mM adenine, 0.037M Na
400 mL of a solution of Cl and 0.20 M sodium acetate (pH
6.2 and 75 ° C.) containing 0.04 mol of host emulsion HA was added to a stirred reaction vessel and 15.0 mL of 4M Ag was added.
NO ₃ solution was added at 1.0 mL / min and 4.5 M Na
The Cl solution was added at the rate required to maintain a constant pCl 1.43. The resulting emulsion was examined by scanning electron microscopy. The resulting emulsion had a crumpled surface and {1
11} angled surface. No {100} major surface was observed. Although the present invention has been described in detail with particular reference to preferred embodiments thereof, it will be understood that changes and modifications can be made within the spirit and scope of the invention.

[Brief description of drawings]

FIG. 1A is a standard view of the {100} major faces of an ideal thin tabular grain satisfying the requirements of the invention having edge crystal faces in the {110} atomic faces. FIG. 1B shows {11
FIG. 3 is a standard view of {100} major faces of another type of ideal thin tabular grain satisfying the requirements of the present invention having edge crystal faces in 1} atomic faces.

2A and 2B are cross-sectional views taken along section lines 2A-2A and 2B-2B in FIG. 1A, respectively.

3A and 3B are cross-sectional views taken along section lines 3A-3A and 3B-3B in FIG. 1B, respectively.

FIG. 4 is an isometric view of conventional {100} tabular grains.

FIG. 5 is a projection electron micrograph of a tabular grain emulsion satisfying the requirements of the invention.

[Explanation of symbols]

 100 ... Tabular grains 102 ... Main surface 104 ... Main surface 106 ... Edge surface 108 ... Edge surface 110 ... Edge surface 112 ... Edge surface 200 ... Tabular particles 202 ... Main surface 204 ... Main surface 206 ... Edge surface 208 ... Edge surface 210 ... Edge surface 212 ... Edge surface 300 ... Tabular grain 302 ... Main surface 304 ... Main surface 306 ... Edge surface 308 ... Edge surface 310 ... Edge surface 312 ... Edge surface S1 ... Slope S2 ... Slope S3 ... Slope S4 ... Slope S5 ... Slope S6 ... Slope S7 ... Slope S8 ... Slope S10 ... Slope S20 ... Slope S30 ... Slope S40 ... Slope S50 ... Slope S60 ... Slope S70 ... Slope S80 ... Slope

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Lois Ambuitano New York, USA 14618, Rochester, Hillside Avenue 936 (72) Inventor Yun Chair Chang United States, New York 14625, Rochester, Cardgan Square 43

Claims (9)

[Claims] 1. A radiation-sensitive emulsion containing a silver halide grain population comprising at least 90 mole percent chloride based on silver, wherein at least 50 percent of the total grain population projected area comprises: (1) Bounded by parallel major faces in the {100} atomic plane and having an adjacent edge ratio of less than 10, and (2) occupied by tabular grains having a thickness of less than 0.2 μm, Each of the tabular grains accounting for at least 50 percent of the total grain projected area includes (3) at least one crystal plane that is in an atomic plane different from that of the main plane, and (4) {100} atomic plane. A radiation-sensitive emulsion characterized by exhibiting a lower grain volume than tabular grains of the same length, width and thickness all bounded by crystal planes at. 2. The radiation-sensitive emulsion according to claim 1, further characterized in that the crystal planes in atomic planes different from those of the main planes are inclined planes arranged adjacent to the grain angle. 3. The radiation of claim 2, further characterized in that the tabular grains accounting for at least 50 percent of the total grain projected area include bevels located adjacent each grain angle or edge. Sensitive emulsion. 4. The slope is {111} or {11}
0} Atomic plane further characterized by:
Alternatively, the radiation-sensitive emulsion according to claim 3. 5. A radiation sensitive emulsion according to any one of claims 2 to 4, further characterized in that the tabular grains having at least one bevel include iodide. 6. The radiation-sensitive emulsion according to claim 2, further characterized in that the emulsion contains thiocyanate. 7. A method according to claim 1, further characterized in that one of the crystal planes in an atomic plane different from that of the main plane is larger than any other crystal plane in the same atomic plane. The radiation-sensitive emulsion according to any one of items 6 to 6. 8. The tabular grains accounting for at least 50 percent of the total grain projected area are comprised of tabular grains each containing eight equal crystal faces at similar atomic planes different from the {100} atomic planes. The radiation-sensitive emulsion according to any one of claims 1 to 6, further characterized by: 9. Radiation sensitivity according to claim 8, further characterized in that the grain growth modifier is preferentially adsorbed on each crystal plane which is in an atomic plane different from that of the main surface. emulsion.