JPS58111937A - Making of radiosensitive photographic emulsion - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of the Invention The present invention provides a method for dispersing silver by contacting an aqueous silver salt solution and an aqueous chloride-containing halide salt solution, which are useful in the photographic field, in the presence of a dispersion medium. Radiation (or radiation) for producing tabular silver halide grains with a halide content of at least 50 mole % chloride (1) Relates to a process for producing sensitive photographic emulsions.

(b) Prior Art Photographic emulsions containing radiation-sensitive silver chloride are known to offer particular advantages. For example, silver pentachloride has a lower natural photosensitivity to the visible portion of the spectrum than other silver halides useful in photography.

Additionally, silver chloride is more soluble than other silver halides useful in photography, so development and fixing can be accomplished in less time.

It is well recognized in the IC photography art that silver chloride has a strong tendency to form crystals with (100) crystal faces. In the vast majority of photographic emulsions, when silver chloride is present, the silver chloride crystals are in the form of cubic grains. With a certain degree of difficulty, this crystallization behavior of silver chloride can be changed. C1aes etc. are”
Cyrstal 1 (abit Modi-fica
tion of AgCl by Ta+purity
es Deters+iningSolvation
”, The Journal of Photo
ra hieScience, vol. 21, 39-50
P., 1973, teaches the formation of silver chloride crystals with (110) and (2) (ilt) planes using various grain growth modifiers.

Wyrsch is-,” 5ulfur 5ensit
Ization of Mono-5ized 5il
ver Chloride Emulstons wi
th (111) + (l l O) , and
(100) Crystal Habit''.

chloride in the presence of ammonia and a small amount of divalent cadmium ions, 1-13, pp. 122-124, 1978. A triple jet precipitation process for precipitating silver is disclosed. In the presence of cadmium ions, pAg
By controlling the (negative logarithm of silver ion concentration) and pH, dodecahedral, octahedral, and cubic crystal habits represented by grain planes located at (110), (111), and (100), respectively, are generated. do.

Although tabular silver bromide grains have been extensively studied, these have been mostly macro-sized and unavailable for photographic applications. Here, tabular grains are
Refers to a particle having two parallel or substantially parallel crystal planes that are substantially larger than the other single crystal planes of the particle.

The (3) aspect ratio (ie, the ratio of diameter to thickness) of the tabular grains is substantially greater than l;1. High aspect ratio tabular tin bromide grain emulsions are de Cugnac and Chateau's “E
revolution of the morpholog
y of 5tlver Broa+1deCryst
as During Physjcal Ripen
ing”, 5cieet Industry
ies Pbotographiques + 33'
t5, Magneto 2 (1962), pp. 121-125.

From 1937 to the 1950s, Eastman Kodasoku Co., Ltd.
d) No.(registered trademark) radiographic film products.
It was sold under the name Screen/X-Ray Coat 5133.

This product included sulfur-sensitized silver bromide emulsion coating layers on opposite major sides of the film support.

This emulsion was intended for exposure to X-ray radiation and was therefore not spectrally sensitized.

The average aspect ratio of the tabular grains was about 5-7:1. In these grains, tabular grains accounted for more than 50% of the projected area, and non-tabular grains accounted for more than 25% of the projected area.

(4) As these emulsions were replicated several times, the emulsion with the highest average aspect ratio had an average tabular grain diameter of 2.5 μm.
m, an average tabular grain thickness of 0.36 μm, and an average aspect ratio of 7:l. Other replica emulsions had thicker, smaller diameter tabular grains with lower average aspect ratios.

Although tabular silver iodobromide grain emulsions are known in the photographic industry, none are known to exhibit high average aspect ratios. Tabular silver iodobromide grains are Duffin's Ph
otographic Emulsion Chemi
stry 1Focal Press+ 1966,
pp. 66-72 and Trivelli and Smlth's 'The Effect of 5ilverIod'
ide 1pon the 5structure o
f Bromo-1 odide Precipitati
on 5eries”, The Photogra
phicJournal, Volume LXXX, 19
July 1940, pp. 285-288. Tr
ivelli and Sm1th observed a significant reduction in both grain size and aspect ratio with the introduction of iodide. “Cutoff” Nucleation and
Growth Rates During theP
Recipitation of 5ilver Ha
ride! mulsions”.

(5) Photographic 5sciences and
Engineering + 1 Volume 4, Nn4
．． July-August 1970, pp. 248-257, reports the preparation of silver bromide and silver iodobromide emulsions of the type prepared by single jet precipitation using a continuous precipitation apparatus. .

Recently, certain processes have been published for producing silver halide emulsions in which the grains are tabular (ie, grains that extend in the plane relative to their thickness).

U.S. Pat. No. 4,063,951 discloses that the aspect ratio (
Here, the ratio of edge length to thickness) is 1.5 to 7:l.
It teaches the formation of tabular silver halide crystals. As shown in FIG. 3 of this patent, the produced silver halide grains have square and rectangular major faces (10(N
Indicates crystal plane characteristics. British Patent No. 4,067,739 discloses forming seed crystals, increasing the size of said seed crystals by Ostwald ripening in the presence of a silver halide solvent, and p
While controlling Br (negative logarithm of bromide ion concentration), (
6) Teach the production of monosized silver halide emulsions with predominantly twinned octahedral crystals by completing grain growth without nucleation or ostwart ripening. There is. US Patent Nos. 4,150,994, 4,184,877 and 4,184,878, British Patent No. 1,570,581 and German Patent Publication No. 29
No. 05655 and No. 2921077 teach the formation of flat twinned octahedral shaped silver halide grains by using seeds that are at least 90 mole percent iodide. Unless otherwise specified, all halide percentages are based on the silver present in the corresponding emulsion, grain, or grain region. For example, particles consisting of chlorobromide containing 60 mole percent chloride contain 40 mole percent bromide.

E. Klein and E. Mo1sar, Berri
chte der Bun-sengesellsch
aft, Volume 67 (No. 4), 349-3551j,
(1963) reported the disturbing effect on the growth of silver chloride grains when purine bases, such as adenine, were added at various stages of emulsion precipitation. US Patent No. 351
No. 9426 discloses the preparation of silver chloride emulsions with increased covering power by precipitation in the presence of azaindenes, such as te(7) traazaindene, pentaazaindene, or adenine.

It has been observed that the covering power of finer grain size silver halide emulsions is greater than that of larger grain size silver halide emulsions, other properties being comparable.

It is known in the photographic field that silver halide grains can be precipitated in the presence of various peptizers. US Pat. No. 3,415,653 discloses the use of a copolymer of vinylamine and acrylic acid as a veptizer to precipitate silver iodobromide grains of various shapes, including tabular. U.S. Pat. No. 3,692,753 describes at least three different types of peptizers, one of which is an acrylamide or acrylate, containing an additional alkyl chain in which the bonded alkyl carbon is replaced with one or two sulfur atoms, as peptizers that can be solidified and redispersed. A copolymer of seven polymers (inLer-(8) polymer) is used. US Patent No. 361
No. 5624 discloses that for peptizing silver chloride, the amine or alcohol condensation residue contains an amide or amide of maleic acid, acrylic acid or methacrylic acid containing an organic radical having at least one sulfur atom bonded to two alkyl carbon atoms. The use of linear copolymers with repeating ester units is disclosed. U.S. Patent No. 3,615,624
In one study of a neutral silver iodobromide emulsion precipitated as in Example 5 of this issue, the emulsion was
It is acknowledged that less than % was due to tabular grains. The tabular grains, although of low aspect ratio, appeared to have peripheral edges parallel to the <211> crystal vector located in the plane of the major faces.

(c) Disclosure of the Invention The object of the present invention is to contact an aqueous silver salt solution and a chloride-containing halide salt aqueous solution useful in the photographic field in the presence of a dispersion medium so that at least 50 mol% of the silver salt is It is an object of the present invention to provide a method for preparing radiation-sensitive photographic emulsions producing tabular silver halide grains with a halide content of chloride (9), which can be incorporated into multilayer photographic elements to enhance sharpness and Appropriate chemical and spectral sensitization can be used to obtain a good sensitivity (speed)-grain size relationship, and spectral sensitization when blue, green and/or red sensitized and incorporated into Shaaran Yoraku Radiation-sensitive photographic emulsions are provided that are capable of producing photographic elements that exhibit increased separation in area sensitivity and ultraviolet light sensitivity.

This purpose is characterized by reacting the silver salt aqueous solution with the chloride-containing halide salt aqueous solution in the presence of a peptizer having an aminoazaindene and a thioether bond. This is accomplished by a method of preparing a radiation-sensitive photographic emulsion in which tabular silver halide grains of a noclogenide device are formed by contacting the emulsion and the like in the presence of a dispersion medium to form tabular silver halide grains of a nochloride device in which at least 50 mole percent of chloride, based on silver, is chloride.

The present invention relates to a method for preparing (lO) high aspect ratio tabular silver halide grain emulsions in which the halide is primarily chloride. In one preferred aspect, the emulsion contains tabular grains of a shape hitherto unknown in the photographic art. In another form, the tabular grains are (bonded throughout by 11N crystal faces and have a different shape than previously obtained with chloride and bromide halide combinations. , the tabular grains include edge faces located in different crystal planes providing a plurality of different adsorption sites, which can reduce competition for adsorption sites due to different additives.

As used herein, the term "high aspect ratio" includes chloride as the predominant halide with a thickness of less than 0.5 μm (preferably less than 0.3 μm) and a diameter of at least 0.6 μm; is greater than 8:l and at least 50% of the total projected area of the predominantly chloride silver halide grains present in the emulsion is based on tabular silver halide grains. The terms average aspect ratio and projected area described below are defined similarly unless otherwise specified.

Preferred high aspect ratio tabular silver halide grain emulsions of the invention have a thickness of less than 0.5 μm (preferably 0.3 μm).
μm) and at least 12 halogenated particles with a diameter of at least 0.6 μm;
It has an average aspect ratio of l. Very high average aspect ratios (50:1.100:1 or higher) can be obtained. In a preferred form of the invention, these silver halide grains account for at least 70%, optimally at least 90%, of the total projected area of the silver halide grains.
Configure.

The aforementioned grain characteristics of the silver halide emulsions produced according to the present invention can be readily ascertained by methods well known to those skilled in the art. As used herein, the term "aspect ratio" refers to the ratio of particle diameter to particle thickness. The term "diameter" of a grain is then defined as the diameter of a circle having an area equal to the projected area of the grain when an emulsion sample is viewed under a light or electron microscope. From shaded electron micrographs of emulsion samples, the thickness and diameter of each grain can be determined, and is less than 0.5 μm (or 0.3 μm) thick and 0.6 μm in diameter.
The above tabular grains can be identified. from now,
The aspect ratio of each tabular grain can be calculated and the aspect ratios of all the tabular grains of the sample that meet the above thickness and diameter criteria can be averaged to obtain their average aspect ratio. This definition will make it clear that the average aspect ratio is the average of the individual tabular grain aspect ratios. in fact,
It is generally easy to determine the average thickness and average diameter of tabular grains with a thickness of less than 0.3 μm and a diameter of 0.6 μm or more, and to calculate the average aspect ratio as the ratio of these two average values. Whether the average of the individual aspect ratios is used to determine the average aspect ratio, or the average of the thickness and diameter is used to determine the average aspect ratio, the resulting average There is virtually no difference in aspect ratio. In the micrograph, the projected area of silver halide grains that meet the thickness and diameter standards mentioned above (13) and the projected area of remaining silver halide grains can be added separately, and these two From the summed values, the percentage of the total projected area of the silver halide grains contributed by grains meeting the thickness and diameter criteria can be calculated.

In the above measurements, reference (or reference) tabular grain thicknesses of less than 0.5 μm (or 0.3 μm) were chosen to distinguish uniquely thin tabular grains from thicker grains with inferior photographic properties. . This is because if the reference grain diameter is smaller than 0, 6, /J m, it is not always possible to distinguish between tabular grains and non-tabular grains in a micrograph. As used herein, [projectedarea] J is widely used in the art [projectedarea]
area or projective area) has exactly the same meaning as the term J, and these are, for example, J
Fundamentals of ames and old ggins
of Photogra hic TheorVIMo
rgan and Morgan+-knee yoke, 15
Please refer to page.

(14) As defined herein, the radiation uA sensitive photographic emulsions of the present invention, in one preferred form, contain tabular grains of novel shape. Typical particle shapes are shown schematically in Figures 1a and 1b. Particle 100 has opposed parallel major faces 102 and 104 as shown.

Looking at the plane in the micrograph, the main plane is the end face 10
6a,b.

It appears as a regular hexagon bounded by c, d, e,' and f. The end face seen in an electron micrograph appears planar. Crystallographic studies have shown that the major faces of the particles are located in the respective (IIN crystal planes).

<211> crystal vectors 108a, 10 shown in FIG. 1a
8b, 110a, 110b, 112a.

and 112b intersect the plane of major surface 102 at an angle of 60°. In particle 100, each of the six end faces is shown as being located parallel to one of the <211> crystal vectors. End surfaces 106a and 106b are located parallel to vector 108, and end surfaces 106c and 106
d is located parallel to vector 110 and end face 106
e and 106f are located parallel to vector 112.

These end faces are thought to be located on the (110) crystal plane,
In some cases, it is specified separately (it seems to be located on the 2201 crystal plane).

The unique crystal structure of the tabular grains defined herein can be further elucidated by reference to the accompanying FIGS. A typical controlled grain of tabular silver chloride is schematically shown. Crystallographic studies suggest that not only major faces 202 and 204 but also end face 206 are located in the (111) crystal plane. This end surface does not appear planar. That is,
In terms of facet and edge configuration, the controlled tabular silver chloride grains appear similar to those in many published studies of tabular and sheet crystals of silver bromide and silver iodobromide. As is evident in the plane, these particles cannot be recognized as regular hexagons. Rather, these particles are typically irregular hexagonal and can be observed as truncated equilateral triangles as indicated by the Danossier lines. According to crystallographic studies, 60
<211> crystal vector 20'8a intersecting at an angle of degrees
, 208b, 210a, 210b, 212a, and 21
2b appears not to be parallel to edge 206. Thus, the end faces of the tabular grains defined herein have a 30° rotation relative to the crystal lattice compared to the end faces of controlled tabular grains and similar tabular silver bromide and silver iodobromide grains. It can be seen as rotating around the axis.

Although tabular grains that appear in micrographs as regular hexagons can be produced according to the present invention, other circumferential shapes have also been produced and observed.

This is shown schematically as a particle 300 in FIG. 3, for example. Instead of having 6 edges, these particles have 6 (1M edges 306a and 6 edges 306a).
06b appear alternately, that is, it appears to have a total of 12 edges. When viewed from the floor plan like this,
These particles can be seen as deca-trigonal (l 7 ) shapes. As indicated by the dashed lines, six additional chips appear to have been obtained by cutting the hexagonal particles at the final stage of their growth. A circle can be seen when the number of edges of a regular polygon reaches infinity, so the reason why a ten-triangle, which is even larger than a hexagon, appears rounder in a micrograph is because of the intersections of those edges. It's no surprise that it looks even more rounded. In one preferred form, the tabular grains as defined herein have a very distinct regular hexagonal shape, an almost circular shape whose flat edges are not easily visually distinguishable;
as well as shapes intermediate between these. In one preferred form, the tabular grains as defined herein are <2 in each case in the plane of one of their major faces.
11> can be characterized as having at least one edge parallel to the crystal vector.

The chloride-containing tabular grain emulsions prepared in accordance with the present invention, in formed form, contain a pebutizer containing (18) thioether linkages as part of the dispersion medium. The thioether bond-containing peptizer is present in the emulsion at the end of precipitation in a concentration of about 0.1 to 10% by weight, based on the total weight. The peptizer can be present entirely in the reaction vessel in which precipitation of the particles occurs, or it can be included in the reaction vessel along with the silver and halide salts through the same or separate jets. However, at least a minimum concentration must be present in the reaction vessel during initial nucleation and subsequent tabular grain growth.

The concentration of the thioether bond-containing peptizer in the reaction vessel is 0.3 to 6% by weight, optimally 0.5 to 2.0% by weight, based on the total weight of the contents of the reaction vessel. It is preferable that it exists in the range of Offi amount %. During precipitation, or preferably after precipitation,
The thioether bond-containing peptizer can be supplemented with any common peptizer to give a total veptizer concentration of up to about 10% by weight based on total weight. The thioether bond-containing peptizer is at least partially adsorbed to the surface of the tabular grains and is not easily completely replaced once an emulsion is formed in its presence.

Nevertheless, after the emulsion is fully formed, the peptizer concentration can be reduced by common washing methods, leaving very little (if any) of the original thioether linkage-containing peptizer in the final emulsion. can.

Common silver halide peptizers containing thioether linkages can be used in the practice of this invention. Particularly preferred thioether bond-containing peptizers are U.S. Pat. Nos. 3,615,624 and 36,927, cited above.
One example is the one disclosed in No. 53. These veptizers preferably include (1) repeating units of amides or esters of maleic acid, acrylic acid, or methacrylic acid in a linear polymer chain, the respective amines or alcohol condensates contained in the respective amides and esters; The residue is a water-soluble linear copolymer containing an organic radical having two alkyl carbon atoms to which at least one sulfide-sulfur atom is attached and (2) containing units of at least one other ethylenically unsaturated monomer. The latter repeating unit typically contains at least one group capable of conferring water solubility to the heptamine at the pH level at which it is precipitated.

For example, said unit is similar to repeating unit (1) above, except that the sulfonic acid or sulfonate substituted alkyl group is replaced by a thioether group containing two alkyl carbon atoms to which sulfide-sulfur atoms are attached. can do. This type of unit is further described in U.S. Patent No. 361,562.
It is disclosed in No. 4.

The thioether bond-containing repeat units preferably represent about 2.5-35 mole percent of the peptizer.

Chloride-containing tabular grains as defined herein are not formed in the absence of a thioether bond-containing peptizer.

Furthermore, the tabular grains are not formed even in the presence of a thioether bond-containing peptizer unless a small amount of crystal modifier is present.

As explained in more detail below with respect to Emulsion 28, in some cases high aspect ratio tabular grain emulsions can also be obtained with iodide as the crystal modifier, but the preferred crystal modifier is is aminoazaine (21). As defined herein, aminoazaindene refers to an azaindene having an amino group attached to the ring at the amino nitrogen atom as a ring substituent. As commonly understood, azaindene is a compound having the aromatic ring structure of indene, but with one or more of the ring carbon atoms replaced by a nitrogen atom. Such compounds, especially those in which 3 to 5 carbon atoms are replaced by nitrogen atoms, have been found to be useful as grain growth modifiers, antifoggants, and stabilizers in photographic emulsions. . Particularly preferred aminoazaindenes for use in the practice of this invention are those having a primary amino substituent attached to the ring member S atom of the tetraazaindene, such as adenine and guanine, sometimes also referred to as aminopurines. It is.

Aminoazaindenes can be used in amounts commonly used as grain growth modifiers, but are effective at very low concentrations, on the order of 10 moles per mole of silver. Useful concentrations can range as high as 0.1 mole per mole of silver (22). It is generally preferred to maintain an amount of aminoazaindene in the silver halide precipitation step of about 0.5.times.10 to 5.times.10 moles per mole of silver in the reactor. Certain aminoazaindenes known to be useful as stabilizers in photographic emulsions are illustrated in US Pat. Nos. 2,444,605, 2,743,181 and 2,772,164. Once the emulsion is formed, the aminoazaindene is no longer needed, but typically at least a portion of it remains adsorbed to the grain surface. Compounds that exhibit a strong affinity for the silver halide grain surfaces, such as spectral sensitizing dyes, can be replaced with aminoazaindenes, thereby allowing the azaindenes to be virtually completely removed from the emulsion by washing.

It is believed that the aminoazaindene and the thioether bond-containing peptizer work together to provide the desired tabular grain properties. In some cases, in the early stages of grain formation, tabular grains were observed to have not only (l l 1) major crystal faces but also (111) edges. As precipitation progressed, transition to dodecahedral main crystal planes was observed. Finally, as the precipitation progresses further, <211> crystal vectors located in the plane of one of the major surfaces appear to indicate regular hexahedral (111) major crystal faces and edges located in the (110) crystal plane. Tabular grains with peripheral edges parallel to can be produced.

Although the present invention is not particularly intended to limit the present invention by the theory that tabular grains having the above-mentioned unique characteristics obtained by the method of the present invention are produced, the present inventors have determined that aminoazaindene is crystallized at each production stage. I think it affects the main chloride particles to slow down the formation of surfaces. Next, this (111) crystal plane is thought to form a double twin plane, which was conventionally regarded as forming tabular grains. Bebutizers containing 1,000-onythyl linkages appear to subsequently induce a transition during the grain growth stage that produces the unique tabular grain edges observed above. This grain growth mechanism idea was confirmed by observing the grains at various stages of grain growth and adjusting the level of aminoazaindene. Increasing the concentration of aminoazaindene results in fully satisfactory particles with a (111) crystalline edge, but the formation of the characteristic particle edge described above is delayed and in some cases eliminated.

When the tabular grain emulsions defined herein are initially precipitated in the absence of halides other than chloride, the central region of the resulting grains is substantially free of either bromide or iodide, and The presence of one or more grain edges located parallel to one or more <211> crystal vectors located in one plane of the surface distinguishes the tabular grains defined herein from other grains. gives advantageous additional structural differences.

At least the central region of the tabular grains as defined herein can be at least 50 mole percent chloride, based on silver, and can further contain substantial amounts of at least one of bromide and iodide.

(25) When bromide and/or iodide are present, they are usually present at concentrations of at least about 0.5 mole percent, but important photographic effects may occur at concentrations as low as 0.05 mole percent. This can be achieved with a compound.

The tabular grains may also contain up to about 10 mole percent iodide, preferably up to 6 mole percent, and optimally up to 2 mole percent. When a halide is included in addition to chloride and iodide, bromide can be included.

In a preferred form of the invention, the tabular grains contain greater than 75 mole % chloride, suitably 90 mole %, based on silver.
Contains higher amounts of chloride. Tabular grains consisting essentially of silver chloride are possible and are particularly preferred in applications where silver chloride emulsions are commonly used. Substantial amounts of bromide and/or iodide can be incorporated into tabular grains without adversely affecting tabular shape, thereby allowing better use in a variety of photographic applications requiring a variety of halides. It is a particular advantage of the present invention that tabular grains can be provided.

At the beginning of emulsion precipitation, a pebutizer (2
6) At least a portion of the dispersion medium containing - and the crystal modifier is present in a reaction vessel containing an effective stirring mechanism.

Typically, the dispersion medium initially introduced into the reaction vessel is
It is at least about 10% by weight, preferably from 20 to 100% by weight, based on the total weight of dispersion medium present in the emulsion at the end of grain precipitation. As taught in Belgian patent no. 886645 corresponding to French patent no. The volume of dispersion medium can be equal to the volume of emulsion present in the reaction vessel at the end of grain precipitation, or even greater than the volume of emulsion. The dispersion medium initially introduced into the reaction vessel is water or a dispersion of veptizer in water, optionally with one or more silver halide ripening agents and as described in more detail below. and/or may include other formulation ingredients such as metal dopants. If peptizer is initially present, it is preferably used in a concentration of at least 10%, more preferably at least 20% of the amount of total peptizer present at the end of the precipitation. Additional dispersion medium is added to the reaction vessel along with the silver and halide salts and can also be introduced through a separate jet.

After the introduction of the salt has been completed, it is a common practice to adjust the proportion of the dispersion medium, in particular to increase the proportion of peptizer.

The pH in the reaction vessel during precipitation is maintained at 1 acidic side with respect to neutrality. The optimum pH level is influenced by the growth modifier and temperature chosen for precipitation. Within the temperature range of 20-90°C, the pH value is within the range of 2-5.0. Precipitation occurs at pH values ranging from about 2.5 to 3.5 and from 40 to 9
Preferably, it is carried out in a temperature range of 0°C. During the precipitation operation, the chloride ion concentration in the reaction vessel is also controlled. Generally useful chloride ion concentrations in the reaction vessel are about 0.
The concentration is 1 to 5.0 molar. The preferred chloride ion concentration is about 0.5 to 3.0 mole once. The ratio of other halides incorporated into the tabular grains can be controlled by adjusting the ratio of chloride to other halide salts introduced. Halide ion concentration in the reaction vessel can be monitored by measuring pAg.

Once tabular grains in which the halide is primarily chloride are formed according to the method of the present invention, other halides can be incorporated into the grains by methods well known to those skilled in the art. The technology for forming a silver salt shell is disclosed in U.S. Patent No. 3.
No. 367778, No. 3206313, No. 3317
No. 322, No. 3917485 and No. 415099
It is shown in No. 4. Since conventional shelling methods are not designed to form high aspect ratio tabular grains, the average aspect ratio of the emulsion decreases as shell growth progresses. If favorable conditions for the formation of tabular grains are present in the reaction vessel during shell formation, shell growth will occur preferentially on the outer edges of the grains and no reduction in aspect ratio will occur. can. Tabular grains can be shelled without necessarily reducing the aspect (29) ratio of the resulting core-shell grains compared to tabular grains used as core grains. High aspect ratio core-shell tabular grain emulsions can be prepared for use in producing direct reversal images.

After the silver chloride tabular grains are formed, by adding both the halide and the silver salt, the original grains remain intact but act as nuclei for the attachment of additional silver halide. Salts that can react with silver to form silver salts that are less soluble than silver chloride, such as thiocyanate, bromide and/or iodide salts, without the addition of silver salts.
When added to emulsions containing primarily tabular chloride grains, these salts will replace chloride in the crystal structure. This replacement begins at the crystal surface and progresses into the interior of the particle. The replacement of chloride ions in the silver chloride crystal lattice by bromide ions, and in some cases by small proportions of iodide ions, is well known. Such emulsions are referred to in the photographic industry as halide-converted halogen 2 (silver oxide) emulsions. Such halide (30)-converted emulsions and techniques for their use are described in U.S. Pat.
No. 3, No. 2592250, No. 2756148, and No. 3622318. In the present invention less than 20 mol %, preferably less than 10 mol % of halide is introduced for substitution. At high levels of substitution, the tabular shape of the grains is degraded and even destroyed. Thus, replacement of bromide and/or iodide ions with chloride ions at or near the grain surface is possible, but not in large quantities, as is commonly done when producing internal latent image-forming grains. The halide conversion of is not considered here.

In forming the tabular silver chloride grains defined herein, an aqueous dispersion medium is charged into a conventional silver halide reaction vessel. The pH and pAg of the dispersion medium within the reaction vessel are adjusted to satisfy the precipitation conditions according to the present invention.

Since the range of pAg that can be used in the practice of the present invention is on the halide side of the equilibrium point (the pAg at which the concentrations of silver and halide ions are stoichiometrically equal), an aqueous chloride salt solution is first prepared. Used to adjust pAg. Thereafter, the silver salt aqueous solution and the chloride salt aqueous solution are simultaneously charged into the reaction vessel. The pAg within the reaction vessel is maintained within the desired range by common measurement techniques and by adjusting the relative flow rates of the silver and chloride salt solutions. Using common sensing techniques, the pH of the reaction vessel is also monitored and maintained within a predetermined range by addition of base while introducing silver and chloride salts. Apparatus and facts for controlling pAg and pH during silver halide precipitation operations are disclosed in U.S. Patent No. 303
No. 1304 and No. 3821002 and C1aes
and Peelaers Photography
e Korrespondenz.

103L, page 161 (1967). As used herein, the terms pAg, pBr, and pt+ are defined as the negative logarithm (reciprocal of the logarithm) of the silver, bromine, and hydrogen ion concentrations, respectively.

Individual silver and halide salts are described in U.S. Pat. No. 3,821,002 to Cuhane et al., U.S. Pat.
hische Korres-〃Flash, hand 10
2 Bunt, November 1967, page 162, surface or internal surface feeding is carried out by gravity feeding or by a delivery device to control the delivery rate and the pi and/or pag of the reaction vessel contents. It can be added to the reaction vessel via a tube. For rapid distribution of reactants within a reaction vessel, U.S. Pat.
No. 3342605, No. 3415650, No. 3785777, No. 4147551, No. 41
71224, UK Patent Application No. 2022431A, German Patent Application No. 2555364 and German Patent Application No. 255688
No. 5, and Total 5earch Disclosure
*Specially constructed mixing equipment can be used, as shown in Volume 166, February 1978, Item 16662. Takumi5earch Disclosure
re and its previous publications, Product, cens↓
I-RojiμL is Industrial 0pportu
nities Ltd, HHomewell, Ha
vant; Hampshire+ PO91EF
.

It is a publication of the United Kingdom.

A particularly preferred method of precipitation is one that shortens the precipitation time by increasing the rate of silver and halide salt introduction during the operation. The rate of silver and halide salt introduction can be increased by increasing the rate of introduction of the dispersion medium and the silver and halide salts, or by increasing the silver and halide salt concentration in the dispersion medium introduced. You can also make it faster by slowing down . It is particularly preferred to increase the rate of introduction of silver and halide salts, but US Pat.
72900 and 4242445, German Publication No. 2107118, European Patent Application No. 801022
No. 42 and -ey's Growth Mechanism
of AgBr Crystals in Ge1a
tin 5 solution''.

Photographic 5science and
As taught in Engineering+ Volume 21, Issue 1, January/Monday 1977, Pages 14 et seq., keeping the introduction rate below a critical level at which the formation of new particle nuclei is likely to occur, i.e., re-nucleation. It is particularly preferred to avoid. Emulsions having a coefficient of variation of less than about 30% can be prepared using the process of this invention. As used herein, the term "coefficient of variation" is defined as 100 times the standard deviation of particle diameters divided by the average particle diameter.

During the precipitation growth stage, re-nucleation is intentionally performed (3,
4) It goes without saying that polydisperse emulsions having substantially higher coefficients of variation can be produced by increasing the coefficient of variation. In addition to those specifically mentioned above, methods for preparing tabular grain emulsions in which the halide content is primarily chloride can take a variety of general forms. The aqueous silver salt solution can be a soluble silver salt such as silver nitrate, while the aqueous halide salt solution can be one or more water-soluble ammonium, alkali metals (e.g. lithium, sodium or potassium) or alkaline earth metals (e.g. Halide salts of magnesium or calcium can be used. The aqueous silver and halide salt solutions can have a wide range of concentrations, for example from 0.2 to 7.0 molar or higher.

In addition to charging the silver and halide salts into the reaction vessel, various compounds are known to be useful in being present in the reaction vessel during the process of silver halide precipitation.

For example, copper, thallium, lead, bismuth, cadmium,
Compounds of metals such as zinc, intermediate chalcogens (ie sulfur, selenium and tellurium), gold and group I noble metals can be present in low concentrations during the precipitation of the silver halide emulsion. This is reflected in U.S. Patent No. 1195432, U.S. Pat.
No. 88709, No. 3737313, No. 37720
No. 31 and No. 4269927 and Re5earc
hDisclosure.

134S, June 1975, item 13452. The distribution of these metal dopants in the tin chloride particles can be controlled by selecting the location of the metal compound in the reaction vessel or by adjusting the addition during the introduction of the silver and chloride salts. can. Tabular grain emulsions are described in the Journal of Mo1sar et al.
Photographic 5science.

25, 1977, pp. 19-27, reduction sensitization can be carried out internally during the precipitation process.

In forming the tabular silver chloride grain emulsion, a dispersion medium is initially included in the reaction vessel. In a preferred form, the dispersion medium consists of an aqueous suspension of peptizer. Pebutizer concentration is 0
．． 2 to about 10% by weight. Maintaining the concentration of veptizer in the reaction vessel at less than about 6% by total weight before and during silver halide production, and adding additional vehicle afterwards to obtain optimal coating properties. A common method is to adjust the emulsion vehicle concentration to a high value by The initially formed emulsion contains about 1 to 50 grams, preferably about 2.5 to 30 grams, of veptizer per mole of silver halide. The vehicle to be added is added later at 1000 g/mole of silver halide.
Concentrations as high as g can be achieved. Preferably, the vehicle concentration in the final emulsion is greater than 50 grams per mole of silver halide. Preferably, the vehicle comprises about 30 to 70 percent by weight of the emulsion layer when coated and dried during the manufacture of the photographic element.

In addition to the aforementioned peptizers containing thioether bonds,
Vehicle (including both binder and peptizer)
can be selected from those commonly used in the preparation of silver halide emulsions (37). Preferred peptizers are hydrophilic colloids, which can be used alone or in combination with hydrophobic substances. Suitable hydrophilic vehicles include proteins, protein derivatives, e.g. cellulose derivatives such as cellulose esters, gelatins such as alkali-processed gelatin (cow bone or leather gelatin) or acid-processed gelatin (pig skin gelatin), e.g. acetylated Included are materials such as gelatin derivatives such as seratin and fudalized gelatin. These and other vehicles are available at Re5earchDisc
losure+ Volume 176, December 1978, Item 1
Described in Chapter 7643.1X. In particular, vehicle materials containing hydrophilic colloids and hydrophobic materials useful therewith are useful not only in the emulsion layers of photographic elements, but also in the overcoat layers,
It can be used in other layers such as interlayers and layers located below emulsion layers.

Grain ripening may occur during the preparation of the emulsion.

Because of its high level of solubility, silver chloride is less affected by the absence of ripening agents (38) than other silver halide solvents known to promote ripening. For example, the ripening agent can be present in its entirety in the dispersion medium in the reaction vessel prior to adding the silver and halide salts, or one or more halide salts, It can also be introduced into the reaction vessel at the same time as adding the silver salt or peptizer. In another variant, the ripening agent can be introduced separately at the halide salt and silver salt addition steps. The ripening agent can be added separately. It can also be introduced subsequent to the introduction of silver and halide salts at step .

The high aspect ratio tabular grain emulsions defined herein are preferably washed to remove soluble salts. This soluble salt is, for example, Re5earch Disclo
sure+ Volume 176, December 1978, Item 176
43. As shown in Chapter ■, decantation,
It can be removed by known techniques such as filtration and/or quenching and leaching.

In the present invention, washing is carried out when the ripening of the tabular grains is completed after the completion of precipitation to increase the thickness of the tabular grains.
It is particularly advantageous to avoid reducing the aspect ratio and/or excessively increasing the diameter. Emulsions with or without sensitizers can be dried and stored prior to use.

According to the method for preparing tabular silver halide grains described above, high aspect ratio tabular grains are produced in which tabular grains satisfying the thickness and diameter criteria for aspect ratio account for at least 50% of the total projected area of all silver halide grains. Although it is possible to prepare tabular grain emulsions, it is recognized that additional advantages are achieved by increasing the proportion of such tabular grains.

Preferably, tabular silver halide grains satisfying thickness and diameter criteria account for at least 70% (optimally at least 90%) of the total projected area.

Although the presence of small amounts of non-tabular grains is not a problem in many photographic applications and the full benefits of tabular grains are obtained, the proportion of tabular grains can be increased. silver halide grains are commonly used separated wave □′
The particles can be mechanically separated from small non-tabular particles in the particle mixture using techniques such as centrifugation or hydrocyclones.

Separation by hydrocyclone is US Patent No. 33266
No. 41 teaches.

The high aspect ratio tabular silver halide grain emulsions defined herein can be chemically sensitized. That is, the emulsion is based on The Theory of theP
Photographic Process, 4th edition, M
acmillan+1977, pages 67-76, and can be chemically sensitized using activated gelatin as described in Re5earch Disclosure.
+l 20t! , April 1974, Item 1200
8,,Re5earch Disclosure
+134 Volume, June 1975, Item 13452, U.S. Patent No. 1623499, U.S. Patent No. 1673522, U.S. Patent No. 2
No. 399083, No. 2642361, No. 3297
447 and 3297446, British Patent No. 131
5755, U.S. Pat. No. 3,772,031, U.S. Pat. No. 376
No. 1267, No. 3857711, No. 356563
3, 3901714 and 3904415 and British Patent No. 1396696.
At °C, sulfur, selenium, tellurium, gold, white (41) gold, palladium, iridium, osmium, rhodium,
Rhenium or phosphorus 4m! ! Chemical sensitization can be performed using agents or combinations of these agents.

Chemical sensitization is sometimes described in U.S. Patent No. 264,236.
In the presence of thiocyanate compounds as described in US Pat. No. 2,521,926;
No. 15 and No. 4,054,457. Chemical sensitization uses finishing (chemical sensitization) modifiers, namely azaindene, azapyridazine, azapyrimidine, benzothiazolium salts,
The process of chemical sensitization can be carried out in the presence of compounds known to suppress fog and increase sensitivity, such as sensitizers with and - or more heterocyclic nuclei. Examples of finish modifiers include U.S. Patent No. 2131
No. 038, No. 3411914, No. 3554757
No. 3565631 and No. 3901714,
Canadian Patent No. 778723 and Duffin's Pho
togra hic E+++ulsion Chem
istr +Focal Press (1966
), New York, pp. 138-143. In addition to chemical sensitization, (42) or alternatively, reduction sensitization can be performed, e.g. with hydrogen, as described in U.S. Pat. 29
Re5earch No. 83609, 0ftedah1 etc.
Disclosure.

Volume 136, August 1975, Item 13654, U.S. Patent Nos. 2,518,698, 2,739,060, 2
No. 743182, No. 2743183, No. 3026
No. 203 and No. 3,361,564, using reducing agents such as stannous chloride, thiourea dioxide, polyamines and amineboranes, or with low pAg (e.g. less than 5) and/or high pH (e.g. 8. It can be reduced sensitized by treatment. US Patent No. 39
Surface chemical sensitization including inner layer surface sensitization as described in No. 17485 and No. 3966476 can be performed.

In addition to chemical sensitization, the high aspect ratio tabular silver chloride grain emulsions of this invention can be spectrally sensitized. Spectral sensitizing dyes can be used that exhibit absorption maxima in the blue and minus blue (ie, fringe and red) portions of the visible spectrum.

In addition, in special fields of application, spectral sensitizing dyes are used to
For example, it is possible to use infrared absorption spectral sensitizers that can improve the spectral response beyond the visible spectrum.

The emulsions of this invention can be spectrally sensitized using various dyes. Dyes used include cyanine, merocyanine, complex cyanine, and complex merocyanine (i.e., tree,
Included are polymethine dyes including tetra- and polynuclear myanines and merocyanines), oxonol, hemioxonol, styryl, merostyryl and streptocyanine.

Cyanine spectral sensitizing dyes include quinolinium, pyridinium, inquinolinium, 3H-indolium, benz(
e) Indolium, oxacillium, oxazolinium, thiazolium, thiazolinium, selenazolium, selenacylinium, imidazolium, imidazolinium,
Henzoxazolinium, benzothiazolium, henzoselenazolium, benzimidazolium, naphthoxazolium, naphthothiazolium, naphthoselenazolium, dihydronaphthothiazolium, pyrylium and imidazopyrazinium quaternary salts It contains two basic heterocyclic nuclei connected by a methine bond, as derived from .

Merocyanine spectral sensitizing dyes include barbituric acid, 2-
Thiobarbic acid, rhodanine, hydantoin, 2-
Thiohydantoin, 4-thiohydantoin, 2-pyrazolin-5-one, 2-isoxazolin-5-one, indan-1,3-dione, cyclohexane-1,3-dione, 1,3-dioxane-4,6- Acidic nuclei and cyanine dye types such as those derived from dione, pyrazoline-3°5-dione, pentane-2,4-dione, alkylsulfonylacetonitrile, malononitrile, isoquinolin-4-one and chroman-2,4-dione. and a basic heterocyclic nucleus linked through a methine bond.

- or more spectral sensitizing dyes can be used.

Dyes are known that have maximum sensitivity at wavelengths throughout the visible spectrum and have a wide variety of spectral sensitivity curve shapes. The choice and relative proportions of dyes depend on the region of the spectrum in which sensitization is desired and the shape of the spectral sensitivity curve desired. Dyes with overlapping spectral sensitivity curves often exhibit a combined shape of the curve where the sensitivity at each wavelength in the overlapping region is approximately equal to the sum of the sensitivities of the individual dyes.

Therefore, by using a combination of a plurality of dyes having different maximum sensitivities, it is possible to obtain a spectral sensitivity curve having a maximum value between the maximum sensitivities of the individual dyes.

Multiple spectral sensitizing dyes can be used in combination, thereby producing supersensitization, i.e., in a certain spectral region.
Spectral sensitization is achieved that is greater than when one of these spectral sensitizing dyes is used alone at any concentration, and greater than the sensitization resulting from the acidic effects of these spectral sensitizing dyes.

Supersensitization involves the addition of a selected set of spectral sensitizing dyes and other additives such as stabilizers and antifoggants, development accelerators or inhibitors, coating aids, fluorescent brighteners, and antistatic agents. This is achieved by matching. Several mechanisms and compounds that may be responsible for supersensitization are all discussed in Photo
ograpbic 5science and (46) Engineering + Volume 18, 1974, 4
Pages 18-430, “Review o” by Gil*an
f the Mechanisa+sof 5uper
sensitization”.

Spectral sensitizing dyes also affect emulsions in other ways. Spectral sensitizing dyes also act as halogen or electron acceptors, antifoggants or stabilizers, and development accelerators or inhibitors, as disclosed in US Pat. Nos. 2,131,038 and 3,930,860.

Among the spectral sensitizers useful for sensitizing silver halide emulsions are Re5earch Disclosure + 1
There is something described in Volume 76, December 1978, Item 177643, Chapter ■.

Typical amounts of dyes can be used to spectrally sensitize emulsions containing non-tabular or low aspect ratio tabular silver halide grains. Optimum amounts (i.e., amounts sufficient to achieve at least 60% of the maximum photographic sensitivity achievable from the grains under likely exposure conditions) of spectral sensitizing dyes at high aspect ratios to provide the full benefits of the present invention. It is desirable that the compound be adsorbed onto the grain surface of the tabular grain emulsion. The amount of dye used will vary based on the particular dye or combination of dyes used and the particle size and aspect ratio. Optimum spectral sensitization is achieved when the surface sensitized silver halide grains have a surface area of about 25 to 1
Monolayer solution TFii corresponding to 00% or more
It is known in the photographic art that this can be achieved when using organic dyes. This means that, for example, The Adsorption of Wes L. et al.
of Sensitizing Dyesin Ph
otographic Emulsions”,
Journal of Phys.

Cheap, + vol. 56, p. 1065, 1952;
"Desensitization" of 5pence etc.
of Sensitizing Dyes” 1
Journal of Physical and C
o11oid Chemistry +56S, No. 6,
June 1948, pp. 1090-1103; and U.S. Pat. No. 3,979,213. The optimal dye density level is determined by Mees' Theory of the Photo.
graphic Process+ 1942, M
aca+1llan+ pages 1067-1069.

Spectral sensitization can be carried out at any stage of emulsion preparation known to be useful in the art.

Most commonly, spectral sensitization is performed following completion of chemical sensitization. However, U.S. Patent No. 3,628,960
As taught in US Pat. No. 4,225,666, spectral sensitization can be carried out simultaneously with chemical sensitization, or it can be carried out entirely prior to chemical sensitization, and even after completion of precipitation of the silver halide grains. You can even start ahead. Incorporation of the spectral sensitizing dye into the emulsion such that a portion of the spectral sensitizing dye is present prior to chemical sensitization and the remainder is introduced after chemical sensitization, as taught in U.S. Pat. No. 4,225,666. can be done separately. Unlike U.S. Pat. No. 4,225,666, 80% of silver halide
After precipitation, a spectral sensitizing dye can be added to the emulsion. In the process of chemical and/or spectral sensitization, p
The sensitization number can be increased by Ag 11 section. pl
A specific example of '1g regulation can be found in Re5search Discl.
o-赳术, Volume 181, May 1979, Item 18155
is shown.

In one preferred form, spectral sensitizers can be incorporated into the emulsions of the invention prior to chemical (49) sensitization. Also, in some cases similar results are achieved by introducing other adsorbent materials, such as finish modifiers, into the emulsion prior to chemical sensitization.

Apart from pre-introducing the adsorptive material, as taught in the above-cited US Pat. No. 2,642,361,
It is preferred to use thiocyanate in a concentration of about 2 X 1 O' to 2 mole percent, based on silver, during the chemical sensitization process.

Other ripening agents can be used during the chemical sensitization process.

In a third approach, which can be carried out in combination with or separately from one or both of the approaches mentioned above, silver and/or halogens present immediately before or during chemical sensitization Preferably, the concentration of the compound salt is adjusted. Soluble silver salts such as silver acetate, silver trifluoroacetate and silver nitrate can be introduced along with silver salts that can be precipitated onto the particle surface such as silver thiocyanate, silver phosphorus, silver carbonate. Male (
50) Fine silver halide grains (i.e., silver bromide, silver iodide and/or silver chloride grains) that can be toard ripened
can be introduced. For example, Lippmann emulsions can be introduced during the chemical sensitization process. Additionally, chemical sensitization of spectrally sensitized high aspect ratio tabular grain emulsions can be accomplished at one or more predetermined remote locations of the tabular grains. In one preferred form, chemical sensitization can occur at selected crystal surfaces of the tabular grains by preferential adsorption of the spectral sensitizing dye onto the crystal surfaces forming the major faces of the tabular grains. Become.

Although not necessary to achieve all advantages, the emulsions of the present invention are optimally chemically and spectrally sensitized according to typical practical manufacturing methods. That is, these sensitizations reduce the maximum, log
A sensitivity corresponding to at least 60% of the sensitivity is achieved.

Here, log sensitivity means 100100 (1-1o), and in this formula, E is the exposure amount expressed in meters-cantleux seconds at a density of 0.3 above fog. Once characterized, whether the emulsion layers of a product are optimally chemically and spectrally sensitized relative to comparable products from other manufacturers can be determined by further product analysis and performance evaluation. To achieve the sharpness benefits of the present invention, it is immaterial whether the silver halide emulsion is chemically or spectrally sensitized efficiently or inefficiently.

As mentioned above, once high aspect ratio tabular grain emulsions have been produced by precipitation methods, washed, and sensitized, their preparation is completed by incorporating commonly used photographic additives. can do. And these can be applied in photographic applications where silver images are to be produced, for example, black and white photography.

Photographic elements in which silver images are formed using the emulsions defined herein can be sufficiently hardened that no additional hardeners need be incorporated during processing.

This hardening can increase silver coverage compared to photographic elements using tabular grain emulsions that are similarly hardened and processed but are not nontabular or high aspect ratio. In particular, the high aspect ratio tabular grain emulsion layers and other hydrophilic colloid layers of black and white photographic elements can be hardened sufficiently to reduce the degree of swelling of those layers to less than 200%. Here, the degree of swelling % is (a) 3 for the photographic element.
Incubate for 3 days at 8° C. and 50% relative humidity, (b) measure layer thickness, (c) photographic element at 21
(d) Determined by immersion in distilled water for three places and then measuring the change in thickness of the (d) layer.For photographic elements to form silver images, it is necessary to include a hardening agent in the processing solution. Although it is particularly desirable that the emulsion be hardened to a certain degree, the degree of hardening of the emulsion according to the present invention may be at any commonly used level.Furthermore, a hardening agent may be added to the processing solution. possible, and this is particularly true with regard to the processing of radiographic materials, e.g.
184, August 1979, item (53) 18431.

A typical useful compound hardener (pre-hardener) is Re5earc.
hDisclosure+ Volume 176, December 1978
Month, Item 17643, Chapter X. Re5e
archDisclosure, Volume 176, 197
By incorporating stabilizers, antifoggants, antikinks, latent image stabilizers and similar additives into the emulsion and adjacent layers prior to coating, as described in December 8, Item 17643, Chapter ■. , increasing the minimum density (ie, fog) in negative-working emulsion coatings, or increasing the minimum density or reducing the maximum density in direct positive-working emulsion coatings. C, E, Me
es, The Theory of the Pho
to-B Mimochiic Process% 2nd edition, Mac
Many of the antifoggants useful in emulsions can also be incorporated into developers and are classified under a few general headings, as described in Millan+ 1954, pages 677-680. be able to.

If an aldehyde type hardener is used, the emulsion layer can be protected with a common antifoggant (54).

In addition to sensitizers, hardeners, and anticaprilants and stabilizers, various other commonly used photographic additives may be present. The specific selection of additives to be used depends on the characteristics of the photographic field of application and can be easily made by one skilled in the art. Various useful additives include Re5earch D
isclosure + l 76 t.

Listed in December 1978, item 17643.

Fluorescent brighteners can be incorporated as described in Entry 17643, Chapter V of the same document.

Absorbing and scattering materials can also be used in separate layers of emulsions and photographic elements according to the invention, as described in Chapter 1 of the same document. Coating aids may also be present, as described in Chapter Xt, and plasticizers and lubricants, as described in Chapter X■. X
An antistatic layer can be present as described in Chapter 2. Methods for adding additives are described in Chapter XIV. Matting agents can be incorporated as described in Chapter XVl, ·'1'.

If desired, developers and development modifiers can be formulated as described in Sections XX and XX1. When photographic elements containing emulsions according to the invention are used in the field of radiography, the emulsion layers and other layers of the radiographic elements can be found in the Re5earch Disclo, cited above.
It can be in any form specifically described in item 18431 of sure. If other conventional silver halide emulsion layers, interlayers, overcoats, and subbing layers are present in the emulsions of this invention as well as in photographic elements,
These (Re5earch Disclosure
, Volume 176, December 1978, Item 176431
．． It can be coated and dried as described in Section XV.

The high aspect ratio tabular grain emulsions of this invention can be blended with each other or with commonly used emulsions to meet the properties required for a particular emulsion layer, according to established practice among those skilled in the art. can. For example, by blending multiple emulsions, the characteristic curve of a photographic element can be tailored to meet a given objective. Blending can increase or decrease the maximum density achieved by exposure and processing, reduce or increase the minimum density, and adjust the shape of the characteristic curve between toe and shoulder. For this purpose, the emulsion according to the present invention was prepared in the above-mentioned Re5search Disclosure + 176
Vol., December 1978, Item 17643.1.

In its simplest form, a photographic element comprises a single silver halide emulsion layer containing a high aspect ratio tabular grain emulsion according to the invention and a photographic support. Of course, more than one silver halide emulsion layer as well as overcoats, subbing layers and interlayers can be included. Instead of blending the emulsions as described above, a similar effect can be achieved by coating the emulsions to be blended as separate layers.

Coating emulsion layers separately to obtain exposure latitude is well known in the photographic art and is described by Zelikman and Levi, Makin and Coatin, P.
Ho Jun'μ 1 Deaf-RIIulsions, Foc
al Press+ 1964, pp. 234-238,
It is described in US Pat. No. 3,662,228 and British Patent (57) No. 923,045. Additionally, it is well known in the photographic art that photographic speed can be increased by coating fast and slow silver halide emulsions in separate layers rather than blending them. The high-speed emulsion layer is coated at a position closer to the exposure source than the low-speed emulsion layer. This approach can be applied to the preparation of three or more stacked emulsion layers. Such a 1-configuration can also be used in implementing the present invention.

Photographic elements can be coated on a variety of supports. Typical photographic supports include polymeric films, wood fibers (e.g. paper), metal sheets and foils, glass and ceramic support elements, and these supports are characterized by their surface adhesion, antistatic properties, and dimensional stability. properties, wear resistance, hardness,
It can have one or more subbing layers to improve frictional properties, antihalation properties and/or other properties. These supports are well known in the art and are available, for example, from Re5earch Disclosure.
+ Volume 176) December 1978, Item 17643, X
It is listed in Chapter ■ (58).

The emulsion layer or layers are usually, but not necessarily, coated as a continuous layer on a support having opposing planar major surfaces. The emulsion layer can be coated as a plurality of laterally displaced layer segments onto a flat support surface. When one or more emulsion layers are used as segments, it is desirable to use a microporous (+1 crocellular) support. Useful microporous supports are described in PCT Publication No. 80101641 (Published August 7, 1980; 1980 Belgian Patent No. 88151 of August 1st
No. 3 and US Pat. No. 4,307,165. The size of the micropores is 1 to 200 μm in width and 1 in depth.
000 μm or less. Generally, in the field of ordinary black and white photography, especially when enlarging photographic images, the size of the micropores is preferably at least 4 μm in width and less than 200 μm in depth, and the best size is about 10 to 10 μm in both width and depth.
It is 100 μm.

Photographic elements employing emulsions of this invention can be imagewise exposed by any conventional method. Regarding this, see Research Disclosure above.

See item 17643, chapter X1. The present invention is particularly useful when imagewise exposure is carried out using electromagnetic radiation in the spectral region in which the spectral sensitizer present exhibits maximum absorption. If blue, green, red or infrared exposures are to be recorded in the photographic element, a spectral sensitizer is present which absorbs in the blue, green, red or infrared portion of the spectrum. In the field of whiteners, it is desirable to orthochromatically or panchromatically sensitize photographic elements to extend sensitivity within the visible spectrum. The radiation used for exposure produced by a laser can be either incoherent (random phase) or coherent (in phase). ambient temperature, high or low temperature and/or subdued, high pressure or Both image exposures at low pressures include T, H, Jaa+es
ory of thePhotograph Hic Pr
ocess, 4th edition, Macmillan+ 1977
may be used within the useful sensitivity range as determined by commonly used sensitometric techniques, as described in Chapters 4.6, 17.18 and 23 of 2003.

Following exposure, the photosensitive silver halide contained in the photographic element is processed in conventional manner by combining the silver halide with an aqueous alkaline medium in the presence of an alkaline medium or developer contained in the photographic element. , can form a visible image.

Once the silver image has been formed in the photographic element, it is common practice to fix the undeveloped silver halide. The high aspect ratio tabular grain emulsion of the present invention is particularly advantageous in that fixing can be completed in a shorter time. This allows for accelerated processing.

The photographic elements and techniques described above for producing silver images can be readily applied to producing color images using dyes. In perhaps the simplest technique for obtaining projectable color images, conventional dyes can be incorporated into the support of the photographic element, (61) and silver image formation can be carried out as described above.

In the areas where the silver image is formed, the photographic element becomes substantially opaque to light, and in other areas, corresponding to the color of the support, it transmits light. Color images can be easily formed in this way. This same effect can also be achieved by using a separate dye filter layer or an element with a dye filter element and a transparent support element.

Silver halide photographic elements can be used to form dye images by selective destruction or formation of dyes. The photographic element for forming the silver image described above is Re5earch
Disclosure + Volume 176, December 1978
It can be used to form dye images by using a developer containing a dye image forming agent such as a color coupler as described in May, Item 17643, Chapter XIV, Section D. In such a form, the developer is a color developer (e.g., an aromatic primary
amines).

(62) Dye-forming couplers can also be incorporated into photographic elements according to conventional methods. Dye-forming couplers can be incorporated in different amounts to achieve different photographic effects. For example, British Patent No. 923045 and British Patent No. 384
No. 3369 teaches limiting the concentration of coupler with respect to silver coverage to less than the amounts normally used in fast and intermediate speed emulsion layers.

The dye-forming couplers that are formulated are usually subtractive primaries (
(i.e., yellow, magenta and cyan) image dyes, these couplers are non-diffusing colorless couplers. Dye-forming couplers with different reaction rates in one or more separate layers can be used to achieve the desired effect in a particular photographic application.

Dye-forming couplers can be used by coupling with development inhibitors or accelerators, bleach accelerators, developers, silver halide solvents, toners, hardeners, couplers, antifoggants, competitive couplers, r, chemical or spectral enhancers. Releases photographically useful fragments such as sensitizers and desensitizers. Development inhibitor releasing (DIR) couplers are well known in the photographic art.

They are non-dye-forming compounds and dye-forming couplers that release a variety of photographically useful groups upon coupling. DIR compounds that do not form dyes when reacted with oxidized color developer may also be used. Silver halide pores with relatively poor photosensitivity, such as Lippmann emulsions, were utilized in interlayers and overcoat layers to prevent or inhibit migration of development inhibitor fragments.

The photographic element may incorporate colored dye-forming couplers and/or competing couplers, such as colored dye-forming couplers used to form layered masks for negative color images.

The photographic element may further include conventional image dye stabilizers. All of these are Re5earchDisc
losure+ Volume 176, December 1978, Item 1
7643, Chapter ■.

Forming or amplifying a dye image by employing a method using an oxidizing agent in the form of an inert reduced metal ion complex and/or a peroxide oxidizing agent in combination with a dye image-forming reducing agent. I can do it.

The dye elements are particularly suited for forming dye images by such methods.

Dye images can be formed in photographic elements by selective destruction of dyes or dye precursors, such as silver-dye-bleaching techniques.

Removal of developed silver by bleaching is common practice in forming dye images in silver halide photographic elements. Removal of such silver can be facilitated by incorporating bleach accelerators or precursors thereof into the processing solutions or into certain layers of the photographic element. In some cases, especially when amplifying dye images as described above, the amount of silver formed by development is small compared to the amount of dye produced. Silver bleaching is thus omitted without substantially visible effects. In still other applications, a silver image is retained and a dye image is utilized to enhance or supplement the density provided by the silver image. When increasing the density of a silver image with dyes, it is usually desirable to use a single neutral dye (65) or a combination of dyes that can produce an overall neutral image.

The present invention can be used to produce multicolor photographic images. Generally, at least one silver halide emulsion I
Conventional multicolor image elements containing - can be improved by simply adding or replacing the high aspect ratio tabular grain emulsions defined herein.

The present invention is fully applicable to both additive and subtractive polychromatic images.

To demonstrate the applicability of the present invention to additive multicolor images, a filter array containing intervening blue, green, and red filter elements is used in combination with a photographic element capable of producing a silver image. be able to. The high aspect ratio tabular grain emulsion defined herein, which is panchromatically sensitized and constitutes one layer of the photographic element, is imagewise exposed through an array of added primary color filters. After processing to produce a silver image, a multicolored image is seen when viewed through the filter array. This image (66) is best viewed by projection. Thus, both the photographic element and the filter array have both or a common transparent support.

Significant advantages are also obtained when the present invention is applied to multicolor photographic elements that produce multicolor images by combinations of subtractive mixed primary color image dyes. Such photographic elements consist of a support and typically at least triad stacked silver halide emulsion layers, i.e., blue, green, and red exposures, yellow, yellow, and red, respectively.
It consists of layers that record separately as magenta and cyan dye images.

As mentioned above, although only one high aspect ratio tabular silver chloride emulsion is required, multicolor photographic elements contain at least three separate emulsions, each recording blue, green, and red light. The emulsions, other than the required high aspect ratio tabular grain green or red recording emulsions, can be of any conventionally commonly used form. Various common emulsions are available in Re5earch Disclosure
re, item 17643° Chapter 1. - If three or more emulsion layers are intended to record in the blue, green and/or red portions of the spectrum, at least the more sensitive emulsion I- contains high aspect ratio tabular grains as described above. Preferably, it contains an emulsion. of course,
All of the blue, green and red recording emulsions of photographic elements are
It goes without saying that if desired, tabular grain emulsions as defined herein are preferred.

Multicolor photographic elements are often referred to as color-forming layer units. The most common multicolor photographic elements contain three stacked color-forming layer units.

Each of these layer units contains at least one silver halide emulsion layer capable of recording exposures in three different spectra and producing complementary subtractive mixed primary color dye images. That is, blue, green, and red recording color-forming layer units are used to produce yellow, magenta, and cyan dye images, respectively. The dye image-forming material need not be present in each color-forming layer unit, but can be supplied entirely from the processing solution. When dye image-forming materials are incorporated into the photographic element, they can be located in emulsion layers or they can absorb oxidized developer or electron transfer agents from adjacent emulsion layers of the same color-forming layer unit. The receptacle can be located in the layer arranged to receive the receptacle.

It is common practice to use scavengers to prevent migration of oxidized developer or electron transfer agents between color-forming layer units with color separation. The scavenger can be located in the emulsion layer itself, as taught in U.S. Pat. No. 2,937,086, and/or between adjacent color-forming layer units, as shown in U.S. Pat. No. 2,336,327. It can be positioned as an intermediate layer.

Each color-forming layer unit can include a single emulsion layer, but has two, three, or three different photographic speeds. or more emulsion layers can often be combined into a single color-forming layer unit. Multiple (usually 2 or 3) blue, green, and/or red layers, if the desired layer sequence does not allow for the inclusion of porous agent layers of different sensitivities in a single color-forming layer unit. It is common practice to include a recording color-forming layer unit in a single photographic element.

The multicolor photographic element can take any convenient form consistent with the requirements noted above. Gorokhovski
i's dudies of the Photograp
hicProcess.

Any of the possible layer arrangements of the human species in Table 272 on page 211, as disclosed in Focal Press, New York, can be used. A typical multicolor silver halide photographic method includes one or more high aspect ratio tabular grain emulsion layers sensitized in the blue region and positioned to receive exposure radiation prior to the remaining emulsion layers. may be added to the element during its manufacture, but most commonly one or more negative blue recording high aspect ratio tabular grain emulsion layers are added to the general negative blue recording element. Preferably, the emulsion layers are replaced, possibly in combination with a change in the layer sequence.

Preferred exemplary embodiments (70) with some layer arrangements shown below. to make it even clearer.

Layer arrangement order I Exposure ■ (71) Ichirin β! Exposure (72) - Exposure (73) Layer arrangement order■ Exposure■ (74) Interlayer sequence order V Exposure (75) Interlayer sequence order■ Exposure■ (76) -1U exposure■ (In the formula, D, G and R are blue, green and red recording color forming layers of any common type, respectively.
(77) T located before said color-forming layer unit B, G, or R comprises one or more of the high aspect ratio tabular silver chloride grain emulsions described in detail above. F indicates an emulsion layer, F located before a color-forming layer unit D, G, or R at least one other color-forming layer unit recording light exposure in the same 1/3 of the spectrum in the same interlayer sequence; indicates a color-forming layer unit with a photographic speed faster than the photographic speed of indicates a color-forming layer unit having a photographic speed slower than that of at least one other color-forming layer unit recording, and IL is an interlayer containing a scavenger that does not substantially disturb the yellow filter material. Show layers.

Each fast or slow color-forming layer unit has a position in the interlayer sequence (78) with another color-forming layer unit that records light exposure in the same third of the spectrum; its unique sensitivity characteristics; Or as a result of a combination thereof, they can differ in terms of photographic sensitivity. ) In the above-mentioned interlayer arrangement orders I to (2), the arrangement of the support is not shown. According to common practice, the support is often positioned furthest from the exposure radiation source. That is,
Generally located at the bottom of the layer. If the support is colorless and specular, ie transparent, the support can be positioned between the exposure source and the layer shown in the figure. More generally, the support can be positioned between the exposure source and any color-forming layer unit in which light transmitted by the support is to be recorded.

Photographic emulsions intended to form multicolor images consisting of a combination of subtractive primary dyes generally take the form of a plurality of stacked layers containing a combination of dye-forming substances such as dye-forming couplers. is never necessary. The three color-forming components, commonly referred to as packets, include a silver halide emulsion that records light in one-third of the visible spectrum and a coupler that can form complementary subtractive primary dyes. can be placed together in layers to produce multicolor images. Examples of mixed packet multicolor photographic elements are U.S. Pat. Nos. 2,698,794 and 2,843,489.
Disclosed in the issue.

The high aspect ratio tabular halogenated set grains defined herein are advantageous because they can reduce high angle light scattering compared to non-tabular, low aspect ratio tabular grain emulsions. This can be shown quantitatively. As shown in FIG. 4, a sample of emulsion 1 as defined herein is coated onto a transparent (specular) support 3 at a coverage of 1.08 g/nf. Although not shown, the emulsion and support are preferably immersed in a liquid having an index of refraction that is substantially matched to minimize Fresnel reflections at the surfaces of the support and emulsion. The emulsion coating is exposed perpendicular to the plane of the support by parallel light #5. Light from the light source following the optical path indicated by dashed line 7, forming the optical axis, strikes the emulsion coating at point A. The light passing through the support and emulsion can be detected at a semicircular sensing surface 9 at a fixed distance from the emulsion. At the intersection B of the first optical path extension and the sensing surface, the maximum intensity level of light is detected.

Point C in FIG. 4 is an arbitrary point selected on the sensing surface.

The dashed line between A and C constitutes an angle φ with the emulsion coating. By moving point C on the sensing surface, this angle φ can be varied in the range 0° to 90°. By measuring the intensity of the scattered light as a function of the angle φ, the cumulative light distribution can be determined as a function of the angle φ (due to the rotational symmetry of the light scattering about the optical axis 7). For the description of the cumulative light distribution, see 口epalwa and Ga5pe.
r's” Determining the 0ptic
al Properties of Photo-gr
aphic Emulsions by the
Monte Carlo Method
(Photography'c 5science an
d Engineering+ Volume 16, Issue 3, 19
May-June 1971, pp. 181-191).

After measuring the cumulative light distribution as a function of the angle φ from 0° to 90° for emulsion l, another part (81) of the support 3 with the same average grain volume coated with the same silver coverage Repeat the same measurements for common emulsions. Comparing the cumulative light distributions determined as a function of the angle φ for the two emulsions up to φ 70° (in some cases up to 80° and above), it is found that the emulsion specified here has a lower amount of scattered light. I understand that. In FIG. 4, the angle θ is the supplementary angle of the angle φ. In this specification, the scattering angle will be explained in terms of angle θ. That is, high aspect ratio tabular grain emulsions exhibit less high angle scattering. Since high angle scattering of light inversely reduces image sharpness, the high aspect ratio tabular grain emulsions defined herein will produce sharper images in any case.

The “convergence angle (col 1ec
-tion angle) The term J refers to the value of the angle θΦ such that half of the light striking the sensing surface falls within the area for the cone produced by the rotation of the line AC around the polar axis of the angle θ, Half of the light falls on the remaining part of the sensing surface.

(82) The theory of reducing the high-angle scattering properties of high aspect ratio tabular grain emulsions as defined herein is not intended to specifically limit the invention to this theory, but It is believed that the improved sharpness is due to the large flat major crystal faces and the arrangement of the grains in the coating. In particular, it has been observed that the tabular grains present in the silver halide emulsion coating are substantially parallel to the planar support surface on which they reside. That is, light normal to the photographic element that hits the emulsion layer tends to impinge on tabular grains that are substantially perpendicular to one major crystal plane.

Due to the thinness of the tabular grains and their placement during coating, high aspect ratio tabular grain emulsion layers can be substantially thinner than conventional emulsion layers, which also enhances sharpness. However, tabular grain emulsion layers exhibit high sharpness even when coated to the same thickness as conventional conventional emulsion layers.

In particularly preferred forms of the invention, the high aspect ratio tabular grain emulsion layers exhibit a maximum zJ<average grain diameter of at least 1.0 μm, most preferably at least 2 μm.

Both improved sensitivity and improved sharpness are obtained due to the increased average particle diameter. Although the maximum average grain diameter useful will vary depending on the grain size acceptable for the particular imaging application, the maximum average grain diameter for the high aspect ratio tabular grain emulsions defined herein is in all cases 30 microns.
m, preferably less than 15 μm, and optimally less than 10 μm
It is less than μm.

Although high angle scattering can be reduced with a single layer coating of tabular grain emulsions of the aspect ratios specified herein, this phenomenon of high angle scattering does not necessarily need to be realized in polychromatic coatings. In some multicolor coating types, high sharpness can be achieved with the high aspect ratio tabular grain emulsions specified herein, while in other multicolor coating types, high sharpness can be achieved with the high aspect ratio tabular grain emulsions specified herein. Tabular grain emulsions can substantially reduce the sharpness of the emulsion layers stacked below them.

Referring to interlayer sequence order I above, the blue recording emulsion layer is located closest to the exposure radiation source and the green recording emulsion layer below is the tabular grain emulsion as defined herein.

This green recording emulsion layer then overlies the red recording emulsion layer. If the blue recording emulsion layer has average diameter grains in the range of 0.2 to 0.6 μm, as is typical in many non-tabular emulsions, then the blue recording emulsion layer will cause light passing through it to be green. and will exhibit maximum scattering such that it reaches the red recording emulsion layer. Unfortunately, if the light has already been scattered before it reaches the green recording emulsion layer of a high aspect ratio tabular grain emulsion, the tabular grains will absorb the light passing through them using the typical conventional It scatters into the blue recording emulsion layer at a larger rate than the emulsion.

Thus, by special selection of emulsions and arrangement of layers, the sharpness of the red recording emulsion layer is significantly reduced to a greater extent than if the emulsions defined herein were not present in said interlayer sequence. let

In order to fully realize the sharpness characteristics of the emulsion layer located below the high aspect ratio tabular silver chloride grain emulsion layer defined herein, the tabular grain emulsion layer (85) must be less susceptible to scattering. It is preferably positioned to receive non-transparent light (preferably positioned to receive substantially specular light). Stated another way, improving the sharpness of an emulsion layer located below a tabular grain emulsion layer is best achieved only when the tabular grain emulsion layer is not located below a turbid layer. can do. For example, if a high aspect ratio tabular grain green recording emulsion layer overlies a red recording emulsion layer and overlies a Knobman emulsion layer and/or a high aspect ratio tabular grain blue recording emulsion layer, then The sharpness of the red recording emulsion layer may be improved by the presence of the overlying tabular grain emulsion layer(s). Stationarily speaking, sharpness of the red recording emulsion layer is improved if the collection angle of the layer or layers overlying the high aspect ratio tabular grain green recording emulsion layer is less than about 10°. can do. Of course, if the red recording emulsion layer itself is a high aspect ratio tabular grain emulsion j- as defined herein, problem (86) is resolved as far as the influence of the overlying layer on its sharpness is concerned. do not have.

In multicolor photographic elements containing stacked color-forming units, to obtain sharpness benefits, the emulsion layer located closest to the exposing radiation source should be at least a high aspect ratio tabular grain emulsion. is preferred. In a particularly preferred form, each emulsion layer located closer to the exposure radiation source than another image-recording emulsion layer is a high aspect ratio tabular grain emulsion layer. The above interlayer sequence order n, m, ■,
v, vi, and ■ are examples of multicolor photographic element emulsion arrangements that can significantly increase the sharpness of the underlying emulsion layers.

The characteristic contribution of image sharpness in multicolor photographic elements of high aspect ratio tabular silver chloride grain emulsions has been specifically described for multicolor photographic elements; They can also be implemented in multilayer black and white photographic elements. It is common practice to divide emulsions forming black and white images into high-speed and low-speed layers. The use of high aspect ratio tabular grain emulsions as defined herein in the layer located closest to the exposure radiation source improves the sharpness of the underlying emulsion layer.

Margin below Example The invention will be further explained according to the following examples.

In each case, the contents of the reaction vessel were stirred vigorously during the introduction of the string and halide salt. Further, "%" indicates weight % unless otherwise specified, rMJ indicates molar concentration unless otherwise specified, and all solutions are aqueous solutions unless otherwise specified.

1 Measurement 21 These emulsions demonstrate that the use of a thioether bond-containing peptizer is essential in order to obtain the high aspect ratio tabular grain emulsions defined herein.

Emulsion l (control) (AgC1, without peptizer) ammonium nitrate (0,12 molar) and adenine (0,12 molar)
1.00 molar aqueous lithium chloride solution (solution A) containing 0.1! was prepared at 7θ°C and pH 3.0. Solution A maintained at initial chloride ion concentration
A silver nitrate aqueous solution (7,θ molar concentration, solution C), lithium chloride (9,0 molar concentration), ammonium nitrate (0,0 molar concentration),
25 molar) and adenine (89) (0.02727 molar) aqueous solution (solution B) was mixed with a double jet at constant speed for 1 min (1.1% of total silver nitrate).
consumption) was added.

Solutions B and C while maintaining the initial chloride ion concentration.
for 9 minutes (98.9% of total silver nitrate) at a flow rate accelerated by a double jet (20 times from start to finish, i.e. the flow rate at the end is 20 times faster than the flow rate at the start).
(consumed).

A total of 0.67 moles of silver nitrate were consumed during precipitation. An aqueous lithium hydroxide solution (1.0 molar concentration, solution D) was used to maintain a pH of 3.0 at 70°C.

LIL (control) (A g C199,8B r O
, 2 gelatin) calcium chloride (0,50 molar concentration),
Ammonium nitrate, monium (0,25 molar), sodium bromide (0,0025 molar) and adenine (0,01
Bone gelatin aqueous solution (1.5% gelatin, solution A) containing 85 molar concentration) 0.1! was prepared at pH 3.0 and 70°C. In solution A, maintained at the initial chloride ion concentration,
An aqueous solution of calcium chloride (4,49 molar concentration) containing nitrate flikM (7,0 molar '4 degrees, 1fic) of water 1fi (90) and ammonium nitrate (0,50 molar concentration) (solution B) was heated in a double jet was added over 12 minutes at an accelerated flow rate (2x from start to finish). pH 3.0
Sodium hydroxide was used to maintain the temperature. During precipitation formation, 0.50 mol of silver nitrate was consumed.

Emulsion 3 (A g C199,8Br O,2, gelatin-peptizer TA/^PSA (2:1))
Poly (3-thiapentyl acrylate-3-acryloxypropane-1-sulfonic acid, sodium salt)
[TA/8P to A (1:6 molar ratio) polymer 0.7
5%], adenine (0,0185 molar), ammonium nitrate (0,25 molar), sodium bromide (0,
An aqueous bone gelatin solution (1,5% gelatin, solution A) containing 0,41% gelatin (1,5% molar) and calcium chloride (0,50 molar) was prepared at pH 3,0 and 70°C. Emulsion 3 was prepared by adding Solutions B, C and D identical to Emulsion 2 to Example 2 in the same manner. A 0.50 molar amount of silver nitrate was consumed during precipitation formation.

Figures 5, 6 and 7 are emulsion 1 (control) and emulsion 2.
(Control) and Emulsion 3.

The magnification in FIG. 5 is 1,500 times, whereas the magnification in both FIG. 65 and FIG. 7 is 600 times. Emulsion 3 contains tabular grains, whereas Emulsion 1 and Emulsion 2 only exhibit the formation of blurred non-tabular grains. Emulsion 1.2
and 3 taken together, the importance of using a peptizer containing thioether bonds to obtain the high aspect ratio tabular grains l (emulsions) defined herein will be appreciated. The properties are shown in more detail in Table 1 below. Unless otherwise noted, in calculating the tabular grain IE mean diameter and percent projected area for the emulsions of these and the following examples, the diameter 0.6
Although some sub-μm tabular grains were included, the presence of insufficient small diameter grains did not significantly shift the reported numbers.

2 (Emulsion 4 (A g CI 99.7B r O,3
, Peptizer-T^/APSA, Single Jet) This example describes the preparation of the emulsion defined herein by a single jet precipitation process.

Aqueous solution of TA/APSA (1:6 molar ratio) containing calcium chloride (1,62 molar), ammonium nitrate (0,25 molar), adenine (0,01515 molar) and sodium bromide (0,00505 molar) (1,25
% polymer, solution A) 0.4N po3. o and 70℃
Prepared with Silver nitrate aqueous solution (7.0 molar concentration, solution B
), while maintaining the initial chloride ion concentration ζ, solution A
was added using a single jet at a constant rate of 1 minute (consuming 1.1% of the total silver nitrate).

Solution B was then added at an accelerated flow rate (20x from start to finish) until solution B was consumed. 9H3
, 0, a sodium hydroxide aqueous solution (1,
0 molar concentration, solution C) was used. The amount of silver nitrate used to prepare this emulsion was 0.67 mole.

The properties of the high aspect ratio tabular grain emulsion defined herein prepared with this emulsion are as shown in Table 1 (93).

”肚L(AgCl99Br1.PeptizerTA/APSA.

Constant Flow Rate) This example describes the use of constant flow rate precipitation to prepare the high aspect ratio tabular ξ-grain emulsions defined herein.

Calcium chloride dihydrate (0.50 molar concentration), adenine (0.02626 molar concentration) and sodium bromide (0.01
An aqueous solution of TA/^PSA (1:6 molar ratio) containing 313 molar concentrations (0,625% polymer, solution A) 0,4
J2 was prepared at pH 2,6 and 55°C. Solution A, which maintains the initial chloride ion concentration, is added to a calcium chloride aqueous solution (3.0 molar concentration, solution B) and a silver nitrate aqueous solution (2.0 molar concentration, solution B).
Molar solution C) was added at a constant rate of 21 minutes over 1 minute using a heavy jet. To maintain the pH at 2.6,
An aqueous sodium hydroxide solution (0.2 molar concentration, solution D) was used. The amount of silver nitrate used to prepare this emulsion was 0.50 mole.

The grain characteristics of the obtained emulsion are as shown in Table 1.

(94) Emulsion 6 (AgC1, Peptizer T^/APSA,
LiC1 salt) This example shows the results of using lithium chloride instead of calcium chloride.

Lithium chloride (1,00 molar concentration), adenine (0,0
TA/APSA (1:6 molar ratio) aqueous solution (1,32% polymer, solution A) containing 0.11 molar concentration) and ammonium nitrate (0.12 molar concentration) at pH 3.0
and 70°C. Solutions B, C and D, identical to those described in Emulsion 1, were prepared and added as in Emulsion 1. The amount of silver chloride used to prepare this emulsion was 0.67 mole.

The grain characteristics of the obtained emulsion are shown in Table 1.

emulsion? (AgC199Br1.Pebutizer TA/^
ps^) This example demonstrates the use of lower reaction vessel temperatures and chloride concentrations to produce the high aspect ratio tabular grain emulsions defined herein.

Adenine (0,02626 molar concentration, calcium chloride (0
, 44 molar concentration), ammonium nitrate (0.25 molar concentration) and sodium bromide (0.01313 molar concentration) in T^/APSA (1:6 molar ratio) aqueous solution (0.63 molar concentration).
% polymer, solution A) 0.41t at pH 2, 6 and 5
Prepared at 5°C. A calcium chloride aqueous solution (3.5 molar concentration, solution B) and a silver nitrate aqueous solution (2.0 molar concentration, solution C) were added to solution A maintaining the initial chloride ion concentration using a double jet at a constant flow rate. Minutes (total nitrate # & silver 0
．． 8% consumed).

1 (after the first minute, solutions B and C were mixed using a double jet with an accelerated flow rate profile (4x from start to finish) of 22.0% of the total silver nitrate for approximately 1 min.
consumed). However, the flow rate of solution B was half that of solution C.

After an IE 11 minute accelerated flow rate addition period, solutions B and C were added at a constant flow rate for 19 minutes. The flow rate of solution B was half that of solution C (77.2% of total silver nitrate consumed). p
To retain H2,6, sodium hydroxide solution/&
The initial chloride ion concentration was maintained during precipitation. The amount of silver nitrate used to prepare this emulsion was 0.50 mol. The grain characteristics of the prepared emulsion are shown in Table 1. Also, a micrograph (magnification: 600 times) of the prepared emulsion is shown in FIG.

Emulsion 8 (AgC1, Pebutizer TA/APSA,
This example demonstrates the preparation of high aspect ratio tabular grain emulsions as defined herein without the inclusion of either ammonium or bromide ions in the reaction vessel (no NH4 or Br present in the reaction vessel). show.

Adenine (0,02626 molar concentration and calcium chloride (
TA/APSA (1:6 molar concentration) containing
molar ratio) aqueous solution (0.63% polymer, solution A) 0.4
1 was prepared at pH 2,6 and 55°C. Sodium hydroxide (0,
An aqueous solution of calcium chloride (3,0 molar) containing 01414 molar concentration (solution B) and an aqueous solution of silver nitrate (4,0 molar, solution C) were mixed at a constant flow rate of 1
minutes (consuming 1.6% of gold and silver). After the first minute, while maintaining the initial chloride (97) ion concentration, solutions B and C were run for 11 minutes (total (consuming 44.0% of silver nitrate).

ε After this 11 minute accelerated flow rate period, solutions B and C were flowed at a constant flow rate for 6.5 minutes (consuming 54.4% of the total silver nitrate).
I added it.

The amount of silver nitrate used to prepare this emulsion was 0.50
It was a mole.

The grain characteristics of the emulsions produced by I.1(il) are shown in Table 1.

Milk JPJ9 (AgCl, Heptizer TA/AP
S.A.

85°C) This example has a precipitation temperature of 85°C and the high 1! 1 shows the production of tabular grain emulsions with aspect ratios.

Calcium chloride (0,50 molar concentration), adenine (0,
TA/APSA containing 02626 molar and ammonium nitrate (0,25 molar) (1:6 molar 2 (ratio) water 7jj'a (1,25% H'J -/-2/8 m
A) 0.4 tt(98) was prepared at pH 3.0 and 85°C. An aqueous solution of calcium chloride (4,5 molar) containing ammonium nitrate (0,50 molar) (solution B), an aqueous solution of silver nitrate (7,0 molar, solution C) and an aqueous solution of lithium hydroxide (1,0 molar, Solution D) was prepared and added to solution A maintaining the original chloride ion concentration in the same manner as in the preparation of emulsion 1.

The amount of silver nitrate used to prepare this emulsion was 0.67
It was a mole.

The grain characteristics of the prepared emulsions are shown in Table 1. A micrograph (600x) of the prepared emulsion is shown in FIG.

Emulsion 10 (AgC199B, rl, Peptizer TA
/APSA) This example illustrates the unique tabular crystal structure that can be produced by practicing the present invention.

Adenine (0,02626 molar concentration, calcium chloride (0
,50 molar concentration), ammonium nitrate (0.25 molar concentration) and sodium bromide (0.01313 molar concentration) in T^/APSA (1:6 molar ratio) aqueous solution (0.63 molar concentration).
% polymer, solution A) 2.0# at pH 2,6 and 55°C
So I did J. Solution A retaining the initial chloride ion concentration
, calcium chloride aqueous solution (3,θ molar concentration, solution B)
and silver nitrate aqueous solution (4.0 molar concentration, solution C) for 1 min at constant flow rate using a double jet (1.6% of total silver nitrate).
consumption) was added.

After an initial 1 min of constant flow rate addition, solutions B and C were added at an accelerated flow rate (4x from start to finish) for 11 min (44% of total silver nitrate) while maintaining the initial chloride ion concentration. 0% consumed).

After this 11 minute accelerated flow rate addition period, Solutions B and C were added at a constant flow rate over approximately 9 minutes (consuming 54.4% of the total silver nitrate) while maintaining the initial chloride ion concentration.

P) Sodium hydroxide aqueous solution (
1.0 molar solution D) was used. The amount of silver nitrate used to prepare this emulsion was 2.5 moles.

Table 1 shows the grain characteristics of the emulsion thus prepared. In addition, a micrograph of the emulsion prepared in this way (6
00x) is shown in Figure 10a. Figures 10b and 100 are electron micrographs taken directly above (0° tilt) and at an angle (60° tilt), respectively, of a sample of emulsion 10.

The magnification of FIGS. 10b and 10c is 1ooo.

It's double.

To compare the crystal structure of the high aspect ratio tabular grains of Emulsion 10 with conventional conventional emulsions containing high aspect ratio tabular grains, grains from a high aspect ratio tabular silver bromide grain emulsion were Used as a control. It has been generally accepted that tabular silver bromide grains are completely surrounded by (l l 1) crystal planes. Tabular silver bromide grains tested for comparison were cooled to the temperature of liquid nitrogen and placed in an electron microscope operating at 100 KV. The electron beam penetrating the tabular silver bromide grains was diffracted by the crystal planes. Six sub-nodes are clearly visible (101) around the central ring in Figure 10d, equidistant from the central beam position. These spots are reflections from the (220) crystal plane. (A second outer ring of spots is also visible, but these are reflections from other crystal planes and are of no direct interest.) Relationship between the generated electron beam diffraction spot pattern and the crystal edge structure Electron micrographs of the test particles are shown oriented at appropriate angles on the electron beam diffraction pattern to demonstrate the properties of the particles. (The appropriate angular configuration was confirmed by using an asymmetric crystal with known diffraction properties for calibration purposes.) From the material composing Figure 10d, six angular configurations corresponding to reflections from the (220) plane It can be seen that the frog's inner reflected sub-throttle lies in the line between the central electron beam and the apex of the hexagon defined by the tabular silver bromide grains.

FIG. 108 is obtained in the same manner using tabular grains obtained from emulsion 1O in place of the grains in FIG. 10d. It is observed that the inner ring of six spots equidistant from the central electron beam position does not lie in a line between the central beam position and the apex of the hexagonal tabular grain (102). Looking at the particle edge, (22
G) The diffraction pattern from the crystal plane appears to be rotated by 30° compared to the diffraction pattern seen in Figure 10d. This is evidence of the unique crystal orientation of the tabular grains defined here. In the first Qe diagram, the <211> spectrum located on the plane of the main surface (not shown)
is perpendicular to the intersection line connecting adjacent points of the six diffraction spots. In each case, the <211> spectrum extends from the central spot on the particle to the apex and is parallel to one of the crystal planes. Thus, the six crystal planes of the tabular grain as shown in FIG. 10e defined herein are parallel to the <211> crystal vector.

From this and other similarly tested emulsion samples, it appears that the tabular grains of Emulsions 4-9 all exhibit similar crystal structures.

” Punishment 11 (AgC199Bl, Pebutizer TPM
A/ AA/ MOBS) In this example, by changing the thioether bond-containing peptizer,
An example of preparing the emulsion as defined herein is given.

This example further demonstrates responsiveness to spectral sensitization.

Poly (3-thousand apentyl methacrylate-co-acrylic acid-2-methacryloyloxy-ethyl-1-sulfonic acid, sodium salt) (TPMA/AA/MO
BS, 1:2:7 molar ratio), an aqueous solution (0,63% Polymer, solution A) 2.0β was prepared at pH 2.6 and 55°C. Add calcium chloride aqueous solution (2,
0 molar, solution B) and an aqueous silver nitrate solution (2.0 molar, solution C) were added using double jets at a constant flow rate over 1 minute (consuming 1.2% of the total silver nitrate).

After an initial 1 minute constant flow rate period, solutions I, B and C were transferred at an accelerated flow rate (2.3 times from start to finish) using double jets while maintaining the initial chloride ion concentration. ) for 53 minutes (consuming 98.8% of total #&silver).

Sodium hydroxide aqueous solution (
0.2 molar solution D) was used. The amount of silver nitrate used in preparing this emulsion was 2.5 moles. The resulting emulsion was separated from most of the soluble salts using a hydrocyclone washing method, after which gelatin was added.

The grain characteristics of the obtained emulsion are shown in Table 1. Further, a micrograph (magnification: 600 times) of the emulsion is shown in FIG.

An unsensitized sample of Emulsion 11 was deposited on a cellulose triacetate support at 1.07 g silver/d and 3.58 g gelatin/lr.
It was coated with a coverage of r. This coated element is 1.07 g/n
1 of the magenta coupler, 1-(6-chloro-2,4-dimethylphenyl)-3-(α-(m-pentadecylphenoxy)butyramide)-5-pyrazolone. This coating is coated with Horton (
® spectrograph for 4 seconds and processed for 2 minutes at 33.4 DEG C. in p-phenylenediamine color developer.

Before coating, the emulsion was mixed with 0.25 t remol 1 mol A35-(
3-Ethyl-2-penzothiazolinylidene)-(105
) 3-β-sulfoethylrhodanine and 0.5% KBr1
The second sample was coated in the same manner as the first, except that it was spectrally sensitized in the blue region with 8 g of mole.

Before coating, the emulsion was mixed with 0.25 mmol 1 mol 88 anhydro-5-chloro-9-ethyl-5'-phenyl-3,
3'-diethyloxacarphocyanine hydroxyto, p
-Toluenesulfonate and 0.5% KBr 1 mol Ag
A third sample was coated in the same manner as the first except that the green region was spectrally sensitized.

In Figure 111a, the log sensitivity of these three samples was plotted as a function of the sunlight illumination wavelength. curve 11
a, llb and llC correspond to the first, second and third samples, respectively. These curves show the effect of expanding the sensitive wavelength range by spectral sensitization.

Emulsion 12 (AgC194Br6.Peptizer-T^/
APSA) This example illustrates the use of a higher proportion of bromine than in the previous examples to prepare the emulsion defined herein.

Calcium chloride (0,500 molar concentration), adenine (10
6) (0,02626 molar concentration, ammonium nitrate (0,25
molar concentration) and sodium bromide (T^/^ps^ (l:6 molar ratio) containing 0.01313 molar concentration) aqueous solution (0.6
3% polymer, solution A) 0.4j! pH 2, 6 and 5
Prepared at 5°C. Solution B (
Calcium chloride 3.00 molar, sodium bromide 0.
18 molar) and solution C (silver nitrate 4.0 molar) were added. Solution D (
NaOH (1.0 molar) was added. The concentration of silver nitrate used to prepare this emulsion was 0.50 molar.

The grain characteristics of the prepared emulsions are shown in Table 1.

Emulsion 13 (AgC189B r 11. Peptizer TPMA/AA/MOES) This example illustrates the preparation of the emulsion defined herein using a higher proportion of bromine than in the previous example.

TPM^/AA/MOf containing calcium chloride dihydrate (0.50 molar concentration), adenine (0.02626 molar concentration) and sodium bromide 1 (0.01313 molar concentration)
! A 0.4A S (1:l near molar ratio) aqueous solution (0.63% polymer, solution A) was prepared at pH 2.6 and 55°C. Solution A, which maintained the initial chloride ion concentration during total precipitation, was added with an aqueous solution of calcium chloride (2.0 molar concentration) containing potassium bromide (0.20 molar concentration) (solution B) and an aqueous solution of silver nitrate (2 molar concentration). , 0 molar concentration, melt 11N, c) for 1 min at a constant flow rate using a double jet (1 of total silver nitrate
．． 6% consumed).

After this first minute of constant flow rate addition, solutions B and C were added at an accelerated flow rate of 1 (1,75 times) from start to finish.
(98.4 of total silver nitrate) for 49 minutes using double jets at
% was added at consumption y′.

Aqueous sodium hydroxide solution (
0.20 mol once, solution D) was used. The salt used to prepare this emulsion! The amount of silver was 0.501 Emol.

The grain characteristics of the prepared emulsions are shown in Table 1 below.

Further, a micrograph (magnification: 600 times) of this emulsion is shown in FIG.

Using a scanning transmission electron microscope for energy dispersive X-ray analysis, individual tabular grains were analyzed for bromine along with appropriate standards.
It was shown to contain bromine at a concentration of 1 mol%.

14-17 These emulsions show examples in which the ratio of the thioether-bonded gold-containing heptamer unit to the sulfonic acid-containing monomer unit to form the polymeric veptizer is varied.

"1L ((A g Cl 99B r 1. Hepticer TPMA/MOES (1:9) ) Adenine (
Poly (
3-thiapentyl methacrylate-2-methacryloyloxyethyl-1-sulfonic acid, sodium salt)
(TPMA/MOBS, 1:9 molar ratio) aqueous solution (
0.63% polymer, solution A) 0.4β was prepared at pH 2.6 and 55°C. Aqueous solutions of calcium chloride (3.0 molar, (109) solution B) and silver nitrate (4.0 molar, solution C) were added to solution A, which maintained the initial chloride ion concentration throughout the entire precipitation period. Addition was made using a heavy jet at a constant flow rate for 1 minute (consuming 1.6% of the total silver nitrate).

After the first minute of constant flow rate addition, f4 solutions B and 5C were added at an accelerated flow rate (4x from start to finish) at 1
Added in 1 minute (44.0% of total silver nitrate consumed).

After an 11 minute accelerated flow rate addition period, solutions B and C were added at a constant flow rate for 9 minutes (54.4% of total silver nitrate was added).

Sodium hydroxide solution (
1.06 molar solution D) was used. Acid silver was used in an amount of 0.50 mole in preparing this emulsion.

Emulsion 15 (AgC199Brl, veptizer l-poor
Emulsion 15 was prepared according to the precipitation method described for Emulsion 14, except that the monomer ratio TPMA/MOBS (1:12) was changed to 1:12.

Emulsion 16 (AgC199BrL Peptizer-2i
TPMA/MOES (1:15)
)(l 10) Emulsion 16 was prepared according to the precipitation method described for emulsion 14 except that the monomer ratio TPM^/MOES was 1=15.
was prepared. Emulsion 17 was prepared according to the precipitation method described for Emulsion 14, except that the seven-mer ratio TPMA/MOBS was 1:18.

The grain characteristics of Emulsions 14-17 are shown in Table 1 below. The micrograph of emulsion 15 (600x magnification) is the 13th
As shown in the figure.

Emulsions 18-20 These emulsions demonstrate variations in the use of decoagulants containing thioether linkages as veptizers in the preparation of the tabular grain emulsions defined herein.

Emulsion 1B (AgC1, Pebutizer TAA/APSA
) Calcium chloride (0,50 molar concentration), adenine (0
,02626 molar concentration and ammonium nitrate (0,25 molar concentration) poly(N-3-thiapentylacrylamideco]3-acryloyloxypropane-1-sulfonic acid, sodium salt) (TAA/APSA,
1:9 molar ratio) aqueous solution (1.25% polymer, solution A) 0.4 J was prepared at pua, o and 80°C. Add emulsion l to solution A while maintaining the initial chloride ion concentration.
Aqueous solution B (calcium chloride 4.5 molar, ammonium nitrate 0.50 molar), aqueous solution C (silver nitrate 7.0 molar) and aqueous solution D (sodium hydroxide 1.0 molar) in the same manner as described for ) was added. This emulsion was prepared in Preparation 1 (the amount of silver nitrate used was 0.6
It was 7 moles.

Emulsion 18 was prepared according to the precipitation method described for Emulsion 1, except that precipitation was carried out at 80°C.

Emulsion 19 (AgC1, Peptizer TA/A^/^PS
A) 1F Calcium chloride (0.50 molar concentration), adenine (0.02020 molar concentration) and ammonium nitrate (
Poly (3-thiapentyl acrylate-co-acrylic acid-co-3-acryloyloxypropane-1-sulfonic acid, nato2(lium salt)) containing 0,25 molar concentration)
(TA/^^/APSA, 1:2:11
molar ratio) aqueous solution (1.25% polymer, solution A) 0.4
N was prepared at pH 3.0 and 80°C. Solution B (4,5
0 molar calcium chloride, 0.50 molar ammonium nitrate), solution C (7,0 molar silver nitrate) and solution D (1,0 molar sodium hydroxide), solution "
A was added in the same manner as described for Emulsion I, maintaining the initial chloride ion concentration throughout. The amount of silver nitrate used to prepare this solution was 0.67 moles.

For each emulsion l (
Emulsion 19 was prepared according to the precipitation method described above.

! L-20 (AgC1, to Veptizer TBA/AA
/^ps^) Poly (N-3-thiabutylacrylamide-co-acrylic acid-2-3-acryloyloxypropane-1-sulfonic acid, sodium salt) (molar ratio l; l
Emulsion 20 was prepared according to the method described for Emulsion 19, except that Emulsion 22 (Nia) was used in place of TA/^A/APSA.

The grain characteristics of Emulsions 18-20 are shown in Table 1.

Micrographs of emulsions 18 and 20 (magnification 21 (11
3) 600x) are shown in Figures 14 and 15, respectively.

EXAMPLE 1 (Ag CI 99B rl, Veptizer TPMA/^A/MOES) This example illustrates the relatively large tabular grain emulsion defined herein with a high percentage of tabular grains.

Calcium chloride (0,50 molar concentration) and adeni7 (
TPMA/AA/MO containing 0,026 molar concentration)
2.01 ES (1:2:9 molar ratio) aqueous solution (0.63% polymer, solution A) was prepared at pH 2.6 and 55°C.

A calcium chloride aqueous solution (2.0 molar concentration, solution B) was added to solution A, which maintained the initial chloride ion concentration throughout the period.
) and an aqueous silver nitrate solution (2.0 molar concentration, solution C) at a constant flow rate for 1 min using a double jet (1.2 molar concentration of total silver nitrate).
% consumed).

After an initial 1 minute constant flow rate addition, solutions B and C were added at an accelerated flow rate (2.3 times from start to finish) for 50 minutes (consuming 98.8% of the gold/silver) using a double shed. added.

(l l 4) Sodium hydroxide aqueous solution (0
, 20 molar, solution D) was used. The amount of silver nitrate used to prepare this emulsion was 2.5 moles.

The grain characteristics of Emulsion 21 are shown in Table 1.

A micrograph (magnification: 600 times) of this emulsion is shown in FIG.

Emulsion 22 (Blue Spectral Sensitization) This example shows the photographic sensitivity of the emulsion defined herein when sensitized with a blue spectral sensitizing dye.

Calcium chloride (0,50 molar concentration), adenine (0,
02626 molar concentration and sodium bromide (0,01313
TA/APSA (1:6 molar ratio) aqueous solution (0.63% polymer, solution A) containing molar concentration 0.41 at pH 2,
Prepared at 6 and 55°C. A calcium chloride aqueous solution (3.0 mol,
Solution B) and an aqueous silver nitrate solution (4.0 mol, solution C) were mixed at a constant flow rate for 1 min using a double jet (1.0 molar of total silver nitrate).
6% consumed).

After the first 1 minute of addition at a constant flow rate, solutions B and C were added using a double jet at an accelerated flow rate (4x from start to finish) for 11 minutes (consuming 44.0% of the total silver nitrate). Ta.

After an 11 minute accelerated flow period, solutions B and C were added at a constant flow rate over approximately 10 minutes (consuming 54.4% of the total silver nitrate).

Aqueous sodium hydroxide solution F6 (0.2 molar concentration, solution D) was used to maintain the pH at 2.6 at 55°C.

The average of silver nitrate used to prepare this emulsion is 0.50
It was a mole.

The emulsion was cooled to 23°C, added to 51 g of distilled water, allowed to stand, decanted, and resuspended in approximately 300 g of aqueous bone gelatin (3% gelatin).

This emulsion was mixed with 0.25 mmol of 5-(3-ethyl-2
-penzothiazolinylidene)-3-β-sulfoethylrhodanine was spectrally sensitized by addition of 1 mol Ag and 0.5% KBr 1 mol Ag. 1.07 g of the spectrally sensitized rice emulsion was deposited on a cellulose triacetate support.
silver/n (and a coating weight of 3.58 g gelatin/-). This coated element also had a coating weight of 1.07 g/rd v,
It also contains the zenta coupler, 1-(6-chloro-2°4-dimethyl-phenyl)-3-(α-(m-pentadecylphenoxy)butyramide]-5-pyrazolone, and is 1.11% based on the total gelatin content. % bis(vinylsulfonylmethyl)ether.The coating was then heated at 600 W through a 0-4.0 density step tablet.
and a tungsten light source at 2850° for 2 seconds. 33.4 in p-phenylenediamine color developer
C. for 2 minutes, and the following sensitometric values were obtained.

Spectral sensitization contrast! ! (shi maximum density dye +
The grain characteristics of KBr 1.44 Q, 20 2.05 Emulsion 21 are shown in Table 1.

A micrograph (magnification: 600 times) of this emulsion is shown in FIG.

1 anus 1 ± (coefficient of variation) This example has a coefficient of variation of approximately 20, which is relatively monodisperse (117
) is an example illustrating the preparation of the emulsion as defined herein.

Calcium chloride (0,66 molar concentration), adenine (0,
02626 molar concentration and sodium bromide (0,01313
T^/APS^ (l:6 molar ratio) aqueous solution (0.63% polymer, solution A) containing molar concentration 0.41 at pH 2.6
and 55°C. Solution A is double jetted with an aqueous solution of calcium chloride (4,5 molar, solution B) and an aqueous silver nitrate solution (2,0 molar, solution C), keeping the initial chloride ion concentration constant throughout the period. using a constant flow rate for 1 minute (consuming 0.8% of the total silver nitrate).

After an initial 1 minute constant flow rate addition, solutions B and C were added at an accelerated flow rate (4x from start to finish) using double jets for 11 minutes (consuming 22.0% of the total silver nitrate).
I added it. The flow rate of solution B was half the addition flow rate of solution C.

After an 11 minute accelerated flow rate period, solutions B and C were added at a constant flow rate for approximately 23 minutes (consuming 70.0% of the total silver nitrate). The flow rate of solution B was half that of solution C.

(118) Aqueous solution of sodium hydroxide (1.0 molar concentration, solution D)
was used to maintain 9H2,6 at 55°C.

The amount of silver nitrate used to precipitate this emulsion was 0.5
It was 0 mole.

The grain characteristics of the obtained emulsion are shown in Table 1. A micrograph (magnification: 600 times) of this emulsion is shown in FIG.

11 This example demonstrates the photographic sensitivity of the emulsion defined herein when sensitized with a blue spectral sensitizing dye and shows the performance compared to that obtained in the absence of the blue spectral sensitizing dye. This is an example for comparison.

Calcium chloride (0,500 molar concentration), adenine (0,
TPMA/A^/MO1iS (1;2
near molar ratio) aqueous solution (0.63% polymer, solution A) 4
．． OIt was prepared at PH 2,6 and 55°C. solution A, maintaining the initial chloride ion concentration throughout the period.
, calcium chloride aqueous solution (2.0 molar concentration, solution B)
and silver nitrate aqueous solution (2.0 molar concentration, solution C) at a constant flow rate for 1 minute using a double shed (1.2% of total silver nitrate).
consumed).

After an initial 1 minute constant flow period, solutions B and C were flowed at an accelerated flow rate (2.3 times from start to finish) using double jets for 52 minutes (consuming 98.8% of the total silver nitrate). ) was added.

Aqueous sodium hydroxide solution (0.2 molar, solution D) was used to maintain pH 2.6 at 55°C.

By the end of this run the pH gradually approached 2.8.

The amount of silver nitrate used to prepare this emulsion was 5.0 moles.

The emulsion was cooled to 23° C., added to 301 g of distilled water, allowed to stand, decanted, and resuspended in approximately 1.4 kg of 4.0% gelatin solution.

This emulsion was mixed with 0.25 mmol of 5-(3-ethyl-2-
Spectral sensitization was achieved by addition of 1 mol Ag of benzothiazolinylidene)-3-β-sulfoethylrhodanine and 1 mol Ag of 0.5% KBr. This spectrally sensitized emulsion was deposited on a cellulose triacetate support at 1.07 g silver/d and 3.58 g silver/d.
The coated element was coated with 1.07 g/rd magenta coupler, 1-(6-convex rho 2.4-dimethylphenyl')-3-(α(m-pentadecyl phenoxy)butyramide]-5-pyrazolone and was hardened with 1.1% bis(vinylsulfonylmethyl)ether based on the total gelatin content.

The coating was then exposed to tungsten antigen at 600 W and 2850° for 2 seconds through a 0-4.0 density step tablet. Processing was carried out in p-phenylenediamine color developer at 33.4°C for 2 minutes. The obtained sensitometric values are as follows.

Spectral sensitization Relative sensitivity Contrast Fog Guino01
Wind.

None 39 0.61 0.1
4 1.40 dye + Br 115 0.
83 0.13 1.76 As is clear from the table above, blue spectrally sensitized tabular AgClBr (99:
1) The grain emulsion exhibited an increased photographic speed of 0.76 logH.

The grain characteristics of this emulsion are shown in Table 1 below, and the LLI characteristics of this emulsion (600 times magnification) are shown in Figure 19 (121).

Margin below (122) [Footnotes to Table 1] *1 Poly(3-thiapentyl acrylate-to-3-acryloxypropane-1-sulfonic acid, sodium salt) *2 Poly(3-thiapentyl methacrylate-to-acrylic acid-co) 2-methacryloyloxyethyl-1
-sulfonic acid, sodium salt) *3 Poly(3-thiapentyl methacrylate-2-methacryloyloxyethyl-1-sulfonic acid,
Sodium salt) *4 Poly(N-(3-thiapentyl)acrylamide-2-3-acryloyloxypropane-1-sulfonic acid, sodium salt) *5 Poly(3-thiapentyl acrylate-acrylic acid-3-acryloyloxypropane) -1
-sulfonic acid, sodium salt) *6 Poly(N-(3-thiabutyl)acrylic (12
6) ) 5) Amide °-co-acrylic acid-co-3-acryloyloxypropane-1-sulfonic acid, sodium salt) Emulsions below the particle standard with a thickness of less than 0.5 μm and a diameter of 0.6 μm or more are specified herein. In the process of growth of tabular grains, there is a transition from the (111) edge to the (l l O) edge. Additionally, these emulsions exhibit suppression of the (110) edge due to the use of higher levels of adenine.

Emulsion 25A [Tabular AgCl with (110) edges
Particles] Calcium chloride (0.50 molar concentration), adenine (0.50 molar concentration),
TPMA/AA/MOES (1:2 near molar ratio) aqueous solution (0.63% polymer, solution A) containing 0.026 molar concentration) and sodium bromide (0.013 molar concentration)
J was prepared at pH 2,6 and 55°C. Solution A, which maintained this initial chloride ion concentration throughout the period, was double jetted with an aqueous calcium chloride solution (2,0 molar, solution B) and an aqueous silver nitrate solution (2,0 molar, (127) solution C). using a constant flow rate for 1 minute (consuming 0.75% of the total silver nitrate).

After an initial 1 minute constant flow rate addition, solutions B and C were added at an accelerated flow rate (2.3 times from start to finish) using double jets for 15 minutes (consuming 18.8% of the total silver nitrate). ) was added.

After a 15 minute accelerated flow rate period, solutions B and C were added using dual jets at a constant flow rate over approximately 46 minutes (consuming 80.5% of the total silver nitrate).

Aqueous sodium hydroxide solution (0.2 molar, solution D) was used to maintain pH 2.6 at 55°C.

The amount of silver nitrate used to precipitate this emulsion was 4.0
It was a mole.

After introducing 1.05 moles of Ag into the reaction vessel, the emulsion was tested and the grains were as shown in FIG. When a grain test was conducted to determine the grain edge as described above for emulsion IO, the tabular grain edge was found to be (
It was found that it is located on the 1111 crystal plane. After introducing 1.68 moles of Ag into the reaction vessel, the emulsion was tested again. As a result, the particles were as shown in FIG. Both FIG. 20 and FIG. 21 have a magnification of 600 times.

Figure 22 is a photograph at 15,500x magnification of a single grain taken from the emulsion shown in Figure 21. Note that there are 12 distinct edges on the particle. Half of the edges are located in the (111) crystal plane and the other half are located in the (110) crystal plane. A in the reaction vessel
After introducing 4.0 moles of g, the emulsion was again tested as described for emulsion IO. This examination revealed that the tabular grains had edges located in the (110) crystal plane. A photograph of this emulsion at a magnification of 600 times is shown in FIG. This example can prove that a transition from the (111) crystal plane edge to the (l l O) crystal plane grain edge occurs during the growth of tabular grains.

Emulsion 25, (Tabular AgC with (111) edge
1 grain] Emulsion 25B was precipitated in the same manner as Emulsion 25A, except that additional adenine was added during the precipitation process. A quantity of 1.0 g of adenine suspended in 25 ml of 0.5 molar calcium chloride solution was added to solution A seven times at 5 minute intervals starting 20 minutes after the start of the precipitation operation. Nitric acid was added at each addition of adenine to maintain pH 2.6 at 55°C.

Emulsion 25A has an average thickness of 0.28 μm and an average grain size of 6.
．． It contained tabular AgCl grains with a 2 μm aspect ratio of 21:l and 80% of the grains being tabular based on projected area. The presence of additional adenine during the precipitation of Emulsion 25B prevented the formation of (110) edges.

Emulsion 25B containing tabular grains of (I'll) Engineering Noji had an average thickness of 0.50 μm, an average grain size of 5.8 μm,
The grains were tabular with an aspect ratio of 11.6:1 and 85% of the grains being tabular based on projected surface area.

Flat AgC1 with 4-drug 26A (4110) edge
Particles] Calcium chloride (0,5 molar concentration) and adenine (0,5 molar concentration)
A 2.0-# aqueous solution of 0.63% by weight of T^/APS^ (1:6 molar ratio) containing (013 molar concentration) was prepared at pH 2.6 and (130) at 70°C. To this solution, which maintained the initial chloride ion concentration throughout the entire precipitation process, a calcium chloride aqueous solution (2.0 molar concentration) and a silver nitrate aqueous solution (2.0 molar concentration) were added using a double jet at a constant flow rate for 1 minute ( 19% of the total silver nitrate was consumed).

After an initial 1 minute constant flow rate addition, the halide and silver salt solutions were added at an accelerated flow rate (1.11 times from start to finish) using dual jets for 4 minutes. The consumption of silver nitrate was 81% of the total silver nitrate.

Aqueous sodium hydroxide solution (0.2 molar) was used to maintain pH 2.6 at 70°C. The amount of #11 silver used to prepare this emulsion was 0.156 mole.

The AgC1 emulsion obtained has hexagonal major faces and (110)
It contained tabular grains with edges. These tabular grains have an average diameter of 1.7 μm and an average thickness of 0.20 μm.
1 had an average aspect ratio of 8.5:1 and was approximately 60% of the total grain projected area.

(131) Emulsion 26B (tabular AgCl grains with (110) and (111) edges) Calcium chloride (0.5 molar concentration) and adenine (0.5 molar concentration)
Poly(N-(3-thiabutyl) containing
acrylamide-2-acrylamido-2-methylpropanesulfonic acid, sodium salt) (1:4 molar ratio>
0.63% by weight aqueous solution 0.41 at pH 2,6 and 55
Prepared at °C. An aqueous calcium chloride solution (
2,277 molar) and an aqueous silver nitrate solution (4.0 molar) were added using double jets at a constant flow rate over 1 minute (consuming 2.5% of the total silver nitrate).

After this first minute of constant flow rate addition, the halide and silver salt aqueous solutions were added using double jets at an accelerated flow rate (4.0x from start to finish) for 20 minutes (total silver nitrate used). 67.0% consumed). The halide and silver salt aqueous solutions were then added using double jets at a constant rate of 3 minutes (consuming 29.6% of the total silver nitrate used).

Aqueous sodium hydroxide solution (0.2 molar) was used to maintain pH 2.6 at 55°C. The amount of silver nitrate used to prepare this emulsion was 0.324 mole.

The resulting AgCl emulsion contained tabular grains with deca-triangular major faces and six (1101) edges and six (111) edges positioned alternately. The tabular grains had an average grain diameter of 1.7μm 1 average thickness 0.196μ
m, with an average aspect ratio of 8.7=1, and accounted for approximately 70% of the total particle projected area.

The following examples illustrate emulsions with average aspect ratios slightly greater than 8=1.

Emulsion 27 (AgC179Br21. Aspect ratio 8
．． 2:1) ↑PM^/^A/MOES (1:
1:7 molar ratio), calcium chloride (0.5 mol i
1 degree), JL sodium chloride 0.0125 molar concentration)
and aqueous solution containing adenine (0,0259 molar concentration) 0
．． 1! into a settling vessel, and °ζp82.6 and 5
Stir at 5°C. Potassium bromide (0,
An aqueous solution of calcium chloride (2,0 molar concentration) containing aqueous calcium chloride (2,0 molar concentration) and an aqueous silver nitrate solution (2,0 molar concentration) were added using a double jet at a constant flow rate for 1 minute (all sets [1 im
The halide salt and silver salt solutions were then fed at an accelerated flow rate (1.6% from start to finish).
．． 75 times) in 48.4 minutes (9 of the total silver nitrate used).
(consuming 8.4%). The initial chloride ion concentration was maintained in the precipitation vessel throughout the entire operation using an aqueous sodium hydroxide solution (0.2 molar) to maintain the pH at 2.6.
It was used. The amount of silver nitrate used to prepare this emulsion was 0.5 moles.

The resulting tabular agglomerated silver emulsion had an average tabular grain diameter slightly larger than 2.0 μm (estimated value 2.05 μm), 0
．． It had an average tabular grain thickness of 25 μm and an average aspect ratio of slightly greater than 8:1 (estimated 8.2:1). Tabular grains account for 50% of the total grain projected area
There were more.

The following emulsions yield tabular grains as defined herein (134
) This is an example showing that iodine can be used instead of aminoazaindene. When using this grain preparation method, it is preferred to use iodine at a grain concentration of about 5 to 10 mole percent, generally speaking, than when aminoazaindene is used according to the preferred method of this invention. A low average aspect ratio is obtained.

Emulsion 28 (chemically and spectrally sensitized A g C199B
rl emulsion) 0.63% TPM^/AA/MOES (1:2:
7 molar ratio) and 0.026 molar concentration of adenine were placed in the reaction vessel. This solution is further 0
．． It contained 5M calcium chloride and 0.0125M sodium bromide. p) l was adjusted to 2.6 at 55°C. Add 2.0M calcium chloride solution and lOMV4@silver solution to this reaction vessel using double jets at constant speed for 1 minute (consuming 1.2% of total silver nitrate used) (2.33x from start to finish) ) for 15 minutes, consuming 30.0% of the total silver nitrate used.

During emulsion preparation, the pct should be measured 1 minute after the start of addition.
5) Added in. The addition of the solution was then maintained at an accelerated flow rate in the reaction vessel. The solution was then added at a constant flow rate for an additional 26 minutes, consuming 68.8% of the total silver nitrate used. During the first third of the precipitation, 0.2M sodium hydroxide solution was added slowly to maintain the pH at 2.6 at 55°C. A total of 2.6 mol of silver nitrate was consumed during precipitation. The emulsion was cooled to 23°C, added to 151 molar concentration of nitric acid, allowed to stand, and finally the solid was
% spine gelatin.

The grains of this emulsion have an average diameter of 4.5 μm and an average thickness of 0.5 μm.
It had a diameter of 28 μm. Particles with a thickness of less than 0.5 μm and a diameter of at least 0.6 μm exhibit an average aspect ratio of 16:1 and account for 80% of the total projected area.
occupied a larger area. The tabular grains obtained were dodecahedral, suggesting the presence of (110) and (l l 1) edges.

Part A where the tabular AgC1 grain emulsion is divided into four parts
was not chemically or photosensitized and was coated on a polyester film support with a Wi loading of 1.07 g silver/- and 4.3 g gelatin/rd.

Part B was sensitized as follows. Gold sulfide (1,0
(1 mol Hg) was added and the emulsion was held at 655°C for 5 minutes. This emulsion was mixed with anhydro-5-chloro-9
-Ethyl-5'-phenyl-3゜3'-bis(3-sulfopropyl)oxacarbocyanine hydroxide, triethylamine salt (0.75 mmol 1 mol Ag) for 40
It was spectrally sensitized for 10 minutes at 100° C. and then coated as in Part A. Chemical and spectral sensitization were optimal for the sensitizers used.

Parts C and D are optimally sensitized.

To Part C, add 0.75 mmol 1 mole Ag of the triethylamine salt of anhydroIF-5-chloro9-ethyl-5'-phenyl-3°3'-bis(3-sulfopropyl)oxacarbocyanine hydroxide; This emulsion was then held at 40°C for 10 minutes.

Next, 3.0 mol% NaBr (total silver halide groups 2
(Semi) was added and the emulsion was held at 40'C for 5 minutes. Next, Na2S20a-5H2Ow 1 mol Ag, Na SCN (16001 g 1 mol Ag) and KAuCl4 (5.1 mol 8 g) were added and the emulsion was held at 65 DEG C. for 5 minutes before coating. The part is lO■
It was sensitized in the same manner as Part C above, except that 1 mol Ag of Na2SλOa.5.0 was used.

Pass the coating through a 600W and 5500° tungsten light source through a θ~4.0 density stencil taplet.11
Exposure was 50 seconds and processed for 10 minutes at 20° C. in N-methyl-p-aminophenol sulfate (Elon®) ascorbic acid surface developer. The obtained sensitometric values are as shown below.

Below margin (138) Ichito-2m- A None *
O, OSB Au2S ten dyes *
0.05C dye+NaBr+ 277
0.06 (S+SCN+Au) D Dye+NpBr+ 298 0.
13 [S→-5CN + Au) * Under the conditions of this experiment, the maximum concentration was 0.0% above fog.
The sensitivity limit level of 1 was not reached. However, images were also obtained for parts A and B by varying the exposure and processing conditions. Parts A and B were about 2 log E less sensitive than parts C and D at 365 nm exposure.

The results in Table 2 demonstrate the excellent sensitivity of the optimally sensitized emulsions.

The following examples are examples in which the tabular emulsions defined herein exhibit greater covering power than comparable non-tabular emulsions of halide composition.

m (nontabular A g Cl 98B r 2 emulsion) (1
39) 0.5 molar calcium chloride bone gelatin aqueous solution (1,
0 wt% gelatin) to 2.01, pH 2.6 and 55°C
A 2.0 molar solution of lesium and a 2.0 molar solution of silver nitrate containing 0.04 molar concentration of sodium bromide at a constant rate of 1 min (containing 0.04 molar concentration of sodium bromide at .9% consumed). Next, the halide and silver salt solution was applied at an accelerated flow rate (3.6 times from start to finish) using a double jet for about 25.
Added in 5 minutes.

(Consuming 50.5% of total silver nitrate). The halide and silver salt aqueous solution was then added at a constant rate for an additional 15.8 minutes, consuming 48.9% of the total silver nitrate used.

Chloride ion concentration was held constant during the entire precipitation.

The amount of silver salt used to prepare this emulsion is approximately 1.15
It was a mole. Following precipitation, the emulsion was dispersed in distilled water, allowed to stand, decanted, and then resuspended in approximately 0.51 aqueous bone gelatin solution (3.0% yield). The grains of this emulsion are non-tabular and have an average diameter of 0.
It was 94 μm.

l limb mu 1 ko (tabular A g Cl 98B r 2 emulsion) 0.625 overlapping% (7) TPMA/AA/MOES
(1:2:7 molar ratio) 0.5 molar calcium chloride and 0.26 molar adenine aqueous solution 2
．． 01, a 2.0 molar calcium chloride aqueous solution containing 0.04 molar sodium bromide and a 2.0 molar silver nitrate aqueous solution were added at a constant speed using a double jet at pH 2.6 and 55°C. 1 minute (4.2 of total silver nitrate used)
% consumed). The halide and silver salt solution was then applied using double jets at an accelerated flow rate (1.4 times from start to finish) for about 19 minutes (consuming 95.8% of the total tin salt used). added. Chloride ion concentration was kept constant during the entire precipitation. Approximately 0.72 mole of silver salt was used to prepare this emulsion. Following precipitation, the emulsion was kept under stirring at 55° C. for 2.5 hours. next,
This emulsion was dispersed in distilled water, allowed to stand, decanted, and an aqueous bone gelatin solution (3,0% direct) of approx.
, 251.

The emulsion contained tabular grains with an average thickness of 0.3 μm, an average diameter of 2.8 μm, and an average aspect ratio of 9.3:1. These tabular grains account for 8 of the projected area of all existing grains.
It accounted for 5%.

Emulsion 29A was deposited on a polyester film support at 3, 26
Similarly, emulsion 29B was coated with 3.07 g silver/d and 11.6 g silver/n (and 11.6 g silver/d).
Coated with 6g gelatin/rd. Both these coatings were passed through a 0 to 6.0 concentration stencil press (0,30 concentration steps) in a mercury vapor lamp at 3'65 nm wavelength.
Exposure for seconds and processing for 6 minutes at 20 DEG C. in n-methyl-p-aminophenol sulfate (Elon) (registration side 1)-hydroquinone developer.

The sensitometric value is this tabular AgCIBr (98:
2) The grain emulsion was shown to have higher covering power than the three-dimensional grain emulsion of AgClBr (98:2). The coverage of emulsion 29A was determined by X-ray fluorescence analysis to be 96
．． It showed a D l1lax density of 1.07 for 1% developed silver. However, the coverage of emulsion 29B was approximately 1
It showed a D wax density of 1.37 for 0.00% developed silver. Non-tabular emulsion grains have a smaller average volume per grain (0.83 (μm)) than tabular (142) grains.
) a vs. 1.85 (μm?) and 3.13 g/nf vs. 3.04 g/n () with more developed silver, and the difference between these two is that the non-tabular compared to the tabular emulsion Although it acts to increase the covering power of the grains, tabular grains give a higher D wax than non-tabular grains and therefore -ci
It gave greater covering power than Agent 29B.

The new radiation-sensitive photographic elements produced according to the method of this invention provide properties in a variety of photographic applications. For example, the emulsions can enhance sharpness when incorporated into multi-photographic elements. The emulsions exhibit better sensitivity-grain size relationships when optimally chemically and spectrally sensitized. The emulsions are blue, green and/or red sensitized and when incorporated into photographic elements produce photographic elements with increased sensitivity separation to the spectral sensitized regions of the spectrum and high ultraviolet sensitivity. Furthermore, the emulsions exhibit properties that increase maximum density and covering power. Furthermore, additional features of the invention include, for example, increased sharpness, increased sensitivity separation in the natural and spectrally sensitized regions of the spectrum, and improved speed-granularity correlation. It is also possible to realize an increase in the sensitivity when blue sensitization is performed, or an increase in the sensitivity particle size correlation.

Further features of the present invention are that radiographic elements with relatively reduced crossover can be obtained, and the performance ratio of photographic speed to silver coverage (i.e., silver halide coverage per unit area) is higher. , image transfer films can be provided that provide faster access to the visible transfer image and provide higher contrast or transfer images with less development time.

[Brief explanation of the drawing]

Figures 1a, 2a and 3 are plane views of individual silver halide grains, Figure 1b is a detailed cross-sectional view taken along line 1b-1b of Figure 1a, and Figure 2b is a detailed cross-sectional view taken along line 1b--1b of Figure 1a. FIG. 4 is a schematic diagram showing sharpness characteristics, and FIG. 5, FIG. 6, and FIG.
Figures 8, 9, 10a, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 and 23 are micrographs of emulsions according to the invention; FIGS. 10b and 10C are electron micrographs of silver halide grains; and FIG. 10d. and FIG. 10e are plan views of silver halide grains showing the diffraction pattern, and FIG.
Correlation between og spectral sensitivity and wavelength IE Patent application agent Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney Yukio Uchida Patent attorney Ishi 1) Honorable patent attorney Akira Yamaguchi b Hirot ItM FIG 10d Treatment by FIG

Claims (1)

[Claims] 1. Bringing a silver salt aqueous solution and a chloride-containing halide salt aqueous solution into contact with each other in the presence of a dispersion medium,
In a method for producing a radiation-sensitive photographic emulsion for producing tabular silver halide grains having a halide content of 0 mol % of chloride, the silver salt aqueous solution and chloride are mixed in the presence of a peptizer having an aminoazaindene and a thioether bond. A method for producing a radiation-sensitive photographic emulsion, which comprises reacting an aqueous solution of a halide salt.