JPS58111936A - Radiosensitive emulsion and making thereof - 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 is useful in the field of photography. The first invention of this application relates to a radiation-sensitive emulsion containing a dispersion medium and silver halide grains. A second invention of this application relates to a method for producing the emulsion.

(b) Prior Art Radiation-sensitive silver halide photographic emulsions containing silver chloride are known and offer particular advantages. For example, other photographically useful silver halides have lower negative sensitivity to the visible portion of the spectrum.

Additionally, silver chloride is more soluble than other photographically useful silver halides, so development and fixing can be accomplished in a shorter time. Silver iodochloride emulsions have found particular utility in applications requiring high contrast, such as printed art, and applications requiring rapid processing, such as black-and-white and color printed products.

A wide variety of grain shapes have been observed in silver halide photographic emulsions. Although various factors such as the presence of grain growth modifiers or ripening agents or the choice of double-jet or single-jet precipitation have a substantial influence on crystal morphology,
There is no other important factor than the halide present during the precipitation.It is well known to those skilled in the art that silver chloride is extremely likely to form crystals with (100) crystal faces. In the overwhelming majority of photographic emulsions, when silver chloride crystals are present, they are in the form of cubic grains.Although there are some difficulties, it has been possible to change the crystalline properties of silver chloride. (claes) et al.
Modification of crystal properties of Agcl by impurities that determine solvation (Crystal HabltModificat
ion of Agcl by Impurities
Det@rming th@Solvatlon)
J, Journal of Photographic Science, Volume 21, Pages 39-50, 1973, Odor, by the use of various grain growth modifiers (110)
and the formation of silver chloride crystals with (111) planes. Wilshi. (vyrach) is r{111
}, (110) and (ioo) crystalline properties of single-dimensional silver chloride emulsions (SulfurSens
Initization of Monomized Si
lvvrChloride Emulsions wi
th ( 1 1 1 }, (110 ) and (
1 0 0 ) Crystal Ha
bit) J, page 79-III-13
, {International Congress of Photographic Science, pp. 122-124, 197
8, disclosed a triple-jet precipitated zorotheth for precipitating chloride pots in the presence of ammonia and small amounts of divalent cadmium ions. Control of pAg and − in the presence of cadmium ions is oblique 12
Hedron {110}, octahedron {1.11}, and cube (
100} gave rise to crystalline properties.

Tabular silver bromide grains have been widely studied, but most of them are of macroscopic size and cannot be used in the photographic field. Tabular grains herein refer to grains having two parallel or substantially parallel crystal faces that are substantially larger than any other single crystal face of the grain. The aspect ratio (ie, the ratio of diameter to thickness) of tabular grains is substantially greater than 1:l. High aspect ratio tabular grain bromide emulsions have been developed by Cugnac and Chat@au.
h@Morphologyof 811vvr Bro
mld@CrystalsDuringPhyslc
al Ripening) J, Science, Engineering, Industry Photography, Volume 33, Volume 2 (19
62), pp. Reported in 121-125.

From 1937 to the 1950s, the Eastman Kodak Company marketed a Desolitized® radiographic film product under the name No Screen X-Ray Code 5133. This product had sulfur sensitized silver bromide emulsion coating layers on opposite main sides of the film support. This emulsion was not spectrally sensitized as it was intended for exposure to X-ray radiation. The tabular grains had an average aspect ratio of about 5-7:1. In this grain, tabular grains occupied more than 50 inches of the projected area, and non-tabular grains occupied more than 25% of the projected area. Out of several replicates of these emulsions, the emulsion with the highest average aspect ratio had an average tabular grain diameter of 2.
5 micrometer λ average tabular grains JlO. 36 micrometers and an average aspect ratio of 7:1.

Other purified emulsions had thicker, larger diameter tabular grains with lower average aspect ratios. Although tabular grain silver iodobromide emulsions are known in the photographic industry, the presence of iozodes is known to limit the asvect ratio. Tabular iodobromide grains are described by Duffin, "Photographic Emulsion Chemistry".
graphic Emulslon Ch@mist
ry) JS Focal Press, 1966, PP-6
6-7 2 and Triperi (Tri▼●111
) and Swiss (8mi th), the influence of silver iodide on the structure of the r'Elk bromide precipitation series (T
h@Eff@ct of 811verIodide
Upon th@Structure@of Bromo
-Iodid@Pr@clpitation S@ri
es) J, De Photographic Journal,
Volume LXXX, l940, July, pp. 2 8 5 -
It was debunked in 288. Tripelli and Smith observed a significant reduction in both grain size and aspect ratio with the introduction of iodide. Gutov
off) rNucleation and growth rate in precipitation formation of silver halide photographic emulsions (Nucl@ation a
nd Growrh Rat@sDurlng th@
Pr@cipitationriSilverHalid
e Photographic Emulsions
) J, Photographic Sciences and Engineering, Volume 14, ▲4, July 1970-
In August, PP-248-257, the preparation of silver bromide and iodobromide complex emulsions of the type prepared by single-jet precipitation using a continuous precipitation apparatus is reported.

Recently, methods have become available for preparing emulsions in which the majority of the silver halide is present in the form of tabular grains. U.S. Pat. No. 4,063,951 teaches the formation of tabular silver halide crystals defined by (ioo)cubic faces and having aspect ratios of 1.5 to 7:1.

These tabular grains have square and rectangular major faces of {100
}Indicates the characteristics of crystal planes. U.S. Pat. No. 4,067,739 discloses forming crystals, increasing the size of the seed crystals by Ostwald ripening in the presence of a silver halide solvent, and p.
By controlling Br (the reciprocal of the logarithm of the bromide ion concentration) and completing grain growth without renucleation or Ostwald ripening, single-dimensional grains that are predominantly twinned octahedral crystals are produced.・The preparation of a thinner silver emulsion is explained. US Pat. No. 4,067,739 does not mention silver chloride. U.S. Patent No. 4,15
0.9 9 4 and 4.1 8 4,8 7
7, British Patent No. 1,5 7 0,5 8 1 and German Patent Publication Nos. 2,9 0 5, 6 5 5 and 2,9 2 1,0 7 7 contain at least 9
The formation of flat twinned octahedral silver octahedral grains is taught by using seeds in which 0 moles are iodide. Here, unless otherwise specified, all halogonide percentages are based on the silver present in the corresponding emulsion, grain, or grain region. For example, a particle made of bromochloride steel containing 60 moles of zolomide also contains 40 moles of 10 chloride. Several of the above references report emulsions with increased covering power and explain their usefulness as both black and white and color camera films. U.S. Patent No. 4ρ6 3951 specifically reports that the upper limit of the aspect ratio is 7=1, but the example only mentions a very low aspect ratio of 2:1. , the 7:1 aspect ratio described herein is considered unrealistic. The aspect ratio seen in the examples and other above-mentioned references from the micrographs is less than 5:1. These references refer to tabular grain halo r
Although he broadly deals with #4 silver emulsions, he does not have specific examples or teachings directed to the preparation of tabular grain silver bromochloride emulsions.・Japanese Patent Publication No. 55-142,329 (November 6, 1980) includes U.S. Patent No. 4,150,99
The teachings are substantially similar to No. 4, but are not limited to the use of silver iodide as the seed grain. This publication also specifically addresses the formation of tabular silver bromochloride grains containing less than 50 moles of chloride.

Although no specific examples of such emulsions are given, considering the information given, following this publication results in a relatively low proportion of tabular silver halide grains; Further, the tabular grains obtained are disclosed in US Pat. No. 415,094.
It appears that the aspect ratio of No. 9 is no higher than that of No. 4.

(QDisclosure of the Invention The object of the present invention is to provide a radiation-sensitive emulsion comprising a dispersion medium and silver halide grains, and a method for producing the same.This emulsion is a conventional converted silver bromochloride emulsion. It has a higher development speed.

In a first invention of this application, this object is achieved by an emulsion having the above-mentioned characteristics, in which the tabular grains have opposing parallel (iii) major faces, and the tabular grains have at least chloride and bromide in the annular grain region, the tabular grains having a thickness of less than 0.3 micrometers, a diameter of at least 0.6 micrometers, and an average aspect ratio of at least 7:1; accounting for at least 35% of the total projected area of the halonide grains, and characterized in that the tabular grains have an average molar ratio of chloride to bromide of 2:31 at least in the annular grain region. .

In the second invention of this application, this object consists of a dispersion medium and silver halide grains, the tabular grains having opposing parallel {111} major faces and containing chloride and promide in at least the annular grain region. and wherein the tabular grains have a thickness of less than 0.3 micrometers, a diameter of at least 0.6 micrometers, and an average aspect ratio of at least 7:1, and the total projected area of the silver halide grains is A radiation-sensitive emulsion comprising at least 35% and wherein said tabular grains have an average molar ratio of chloride to promide of up to 2:3 in at least said barbed grain region is placed in a reaction vessel containing at least a portion of a dispersion medium. silver,
A method for producing by simultaneously introducing chloride and promide salts, the molar ratio of chloride ions to promide salts in the reaction vessel is maintained at 1.6:1 to 258:1, and the molar ratio of chloride ions to promide salts in the reaction vessel is maintained at 1.6:1 to 258:1. Set the total concentration to 0
．． Maintaining it within the specified range of 10 to 0.90 is defined as % copying.

In a preferred embodiment, the emulsions of the invention have a high aspect ratio. A "high aspect ratio" candy, as applied to the emulsions of the present invention, comprises chloride and bromide in at least the annular grain region and has a thickness of less than 0.3 micrometers and a diameter of at least 0.6 micrometers. (1) tabular silver halide grains having an average aspect ratio of greater than 8=1, and (d) occupying at least 35 inches of the total projected area of the silver halide grains.

All average aspect ratios and projected areas, which will be discussed later, are
The same shall be determined unless otherwise specified.

Although the emulsions according to the invention may have an average aspect ratio of 7:1, it is preferred that they have a high average aspect ratio of greater than 8:1. The average aspect ratio is l5
:1, up to 30:1, or even higher. Preferred emulsions of the invention have an average thickness of less than 0.2 micrometers. In a preferred embodiment of the invention, these tabular grains account for at least 50%, and optimally at least 70%, of the total cast area of the 71-hole silver grain containing chloride and bromide in at least the annular grain region. occupy

The thinner the thickness of the tabular grains that account for a given percentage of the projected area, the higher the average aspect ratio of the emulsion. Typically, the tabular grains have an average thickness of at least 0.10 micrometers, although the principle K may be thinner.

It is known that the thickness of tabular grains can be increased to suit special applications. For example, planar grains having an average thickness of up to 0.5 micrometers can be used in image transfer films. For such applications, 0.3 for determining the aspect ratio
All references to micrometers should be corrected to 0.5 micrometers. However, in order to achieve higher aspect ratios without unduly increasing the grain size, the flat root grains of the emulsions of this invention must be 0.
It is usually possible to have an average thickness of less than 3 micrometers.

The above-mentioned grain characteristics of the emulsion according to the present invention can be easily determined by techniques well known in the art. As used herein, the term "aspect ratio" refers to the ratio of diameter to thickness of a particle. The "diameter" of a grain refers to the diameter of a circle having a surface pole equal to the projected area of the grain when the emulsion is observed under a microscope or an electron microscope. From shaded electron micrographs of emulsion samples, the thickness and diameter of each grain can be determined and tabular grains with a thickness of less than 0.3 micrometers and a diameter of at least 0.6 micrometers can be identified. I can do it. The aspect ratio of each tabular grain can be calculated from the straightness and thickness determined in this way, and when the thickness is 0.
The aspect ratios of all tabular grains in a sample that meet the criteria of less than 3 micrometers and at least 0.6 micrometers in diameter can be averaged to obtain an average aspect ratio. As is clear from this, the average aspect ratio is the average of the aspect ratios of individual tabular grains. In practice, the average thickness and average i7J diameter of the tabular grains, typically 0.3 micrometers thick and at least 0.6 micrometers south, are determined, and the average of these two is 1vIc? ) ratio @1 to obtain the −C average aspect ratio. Even if the average aspect ratio is determined by taking the average value of the individual aspect ratios or by calculating from the average value of the thickness and ridge shape, as long as the average aspect ratio is within the range of particle size determination, The average aspect ratios obtained are virtually the same. Calculate the projected area of the tabular silver halide grains that satisfy the thickness and diameter criteria, and separately calculate the projected area of the halide grains (remaining in the photograph), and From these two extreme values, it is possible to determine the percentage of the total projected area of the silver octaronide grains occupied by tabular grains that satisfy the thickness and directness criteria.

Standard tabular grains with a thickness of less than 0.3 micrometers were selected in the above determinations to distinguish them from thicker tabular grains with inferior imaging properties. The quasi-particles were chosen to have a diameter of at least 0.6 micrometers. This is because when the th shed is smaller, tabular and non-tabular grains cannot always be distinguished in micrographs. For example, Zoames (Jam●--) is a candy that is widely used in this industry.
) and Higgins, Fundamentals of Photographic Theory (Funclam*ntals of Pbo
tographjc Theory) Js Morgan●
See Ande Morgan, N.Bltp-15.

In certain preferred embodiments of the invention, the emulsion halo r
The silver chloride grains essentially consist of iodochloride. The molar ratio of chloride to zolomide can range up to 2:3. Photographically effective modifying effects result from chloride concentrations as low as about 1 molar.

Chloride concentrations of 1 to 30 molar are preferred, with concentrations of 5 to 20 molar being optimal for the practice of this invention. The remaining halide may consist essentially of bromide. The ratio of chloride to bromide is substantially uniform throughout the particles and can be varied as desired within the ranges stated above. The ratio of chloride to noromide can be made to increase from the central grain field to the surrounding loamy grain field. This increase may be discrete or may vary gradually. The ratio of chloride to pro-density may be reversed. Moreover, even if the ratio of chloride to zolomide is increased for the shaped particle region κ that is in close contact with the spring surface,
May be reduced.

In addition to silver, chloride and bromide, the tabular grains of the present invention can, but need not, contain iodine. k of iodine present in tabular grains
may vary widely as long as the stated chloride to propod ratio is maintained. The possible range of Taichidide depends on its position within the particle. It is generally preferred that the i-dide concentration be less than about 3 molar, optimally less than 0.05 molar, during particle nucleation, i.e., formation at or near the center of the particle. After nucleation (i.e. while the ape part around the lateral force direction is being grown), a much higher iodine concentration up to the solubility limit in the growing bromochloride crystal region of the iodide complex presides. It is. Therefore, the iodide concentration in the annular particle region may be up to greater than 1, but preferably less than 20 molar, and optimally less than 15 molar. If the concentration of iodide in the loamy grains is higher than the iodide concentration present in the nucleation of tabular grains, the effect on the destroyed emulsion is that the iodide concentration during precipitation is As a result, the iodine degree of the central particle region increases. Iodide migration
Of course, the degree of 7 points will vary depending on the precipitation conditions, especially the solubility and ripening conditions of the halogenated flax.

The iodide concentration of the tabular silver halide grains of the present invention may be uniform throughout or may be varied as desired depending on the above considerations. In the loamy particle region it is even higher (at least 1 mole per bird)'! ! - Can have a dido concentration.

It is possible to increase the density of the particles in the particles dramatically or gradually. The concentration can be increased between the central particle region and the annular particle region and then decreased again towards the outer edges of the particle.

Tabular grain silver halide emulsions having at least cyclic grain regions comprising chloride and t-lomide can be prepared by a precipitation process and this process also forms part of the invention. The dispersion medium is placed in a conventional silver halide precipitate reactor equipped with an efficient stirring mechanism. Usually, the amount of dispersion medium introduced into the reactor in the first stage is at least about 20 to 100 toots, preferably from 20 to 100, based on the total Iml of dispersion medium present in the emulsion in the final grain precipitation stage.
It weighs one. As taught in Belgian Percentage No. 866,645 (corresponding to French Special Fraud No. 2,471,620), the dispersion medium can be removed from the reactor by a centrifugal divider during the particle precipitation process. Therefore, the amount of dispersion medium initially present in the reactor can be equal to or even greater than the amount of emulsion present in the reactor in the final grain precipitation stage. The dispersion medium initially introduced into the reactor is water or a dispersion of a peptizer in water, and this dispersion is optionally combined with other components, such as one or more halo-silver oxides. compounding agents and/or metal dau agents (de d'andt) as detailed in him. If a peptizer is initially present, its concentration is at least 10% of the total amount of peptizer present at the final stage of precipitate formation, especially at least 4%
It is preferable that it is 0 excellent. Additional dispersion medium is added into the reactor along with the complex and halide salt, which can be introduced through a separate jet. Generally, the proportion of dispersion medium is adjusted after the halide salt introduction is completed, especially to increase the proportion of peptizer. Tabular shape containing chloride and pro-carbon in the central grain region...
In a preferred practice of the process in which tabular silver grains are formed, a small amount, typically less than 10 moles, of the chloride and noromide salts used to form the tabular grains are initially present in the reaction vessel; Adjust the concentration of ions in the dispersion medium at the beginning of precipitate formation. The dispersion medium in the reactor is initially 0.0
Preferably, it contains less than 5 molar iodide ions and is initially free of iodide ions. This is because the presence of iodide ions in the reactor before the simultaneous introduction of button, chloride, and promide salts tends to produce tabular grains with low aspect ratios. Ionodide salts are added to the reactor with silver, chloride, bromide and Ffi* according to techniques well known to those skilled in the art to form a precipitate. Usually, at the same time as the introduction of the no-ride salt, a water seedling solution of a malleable silver salt such as silver nitrate is introduced into the reaction mixture. Additionally, the no-ride salts are usually 1 or more CIj bath ammonium, alkaline gold (e.g., sodium or potassium) or alkaline earth gold (e.g., magne 7, still calcium) halide salts. Introduced as a saline solution, such as a water bath solution. At least initially, the Kushi salt is introduced into the reactor separately from the halide salt. No.1
The ride salts may be added separately to the reaction mixture or may be introduced as a mixture.

Instead of introducing the pot and the halide salt as an aqueous solution, the silver and...ride salts can be introduced initially or during the growth stage in the form of fine silver halide particles suspended in the dispersion medium. The particle size is such that when introduced into the reactor, it readily undergoes Ostwald ripening into larger particle nuclei that may be present. Useful reed macroparticle sizes will depend on the conditions within the reactor, ie, temperature and the presence or absence of solubilizing and ripening agents. Saw bromide, silver chloride and/or mixed silver halide grains can be introduced. It is desirable that the silver halide grains be very narrow, eg, having an average diameter of less than 0.1 micrometer.

In order to arrange chloride in the tabular grains in the proportions mentioned above, it is essential that chloride ions be present in the reaction vessel in a much higher proportion than prod ions. In particular, in order to achieve a 1:99 molar ratio of chloride to bromide in the tabular grains, a molar ratio of chloride to bromide ions of 1.6:1 must be present in the reaction vessel.

In order to increase the molar ratio of chloride to zolomide in the tabular grains to 2:3, the molar ratio of chloride to promide ions in the reaction vessel can be increased to 258:3 depending on the if of precipitation formation.
It would be necessary to increase it to 1. The typical molar ratio relationships of chloride F and bromide ion accumulation ratios in the reaction vessel and of chloride and bromide obtained in tabular grains are expressed as follows:
Extreme precipitation temperatures of 0 and 90°C and 40-80°C
For a precipitate formation temperature of 55°C, which is within the preferred precipitate formation knitting range of 0°C, as shown in Table 1 below. However, other values can be determined by extrapolation or interpolation.

In order to obtain tabular silver halide grains according to the present invention,
It is further necessary to control the total concentration of ions present in the reactor. Approximately 0.10~0
．． A total halodane ion concentration in the reaction vessel in the range of 90 N is required to give the chloride and zolomide precipitates a tabular crystal character.

To maximize the proportion of tabular grains of the desired 7 spectral ratio produced during coprecipitation, the total halo ion concentration in the reaction vessel is in the range of about 0.30 to about 0.60N. Preferably, it is retained.

The above precipitation process can be used for the formation of chloride and ploid containing tabular grain nuclei and for the growth of grain nuclei to the desired tabular grain thickness and aspect ratio. Alternatively, a precipitation process can be used to co-precipitate chloride and zolomide of tabular crystal character onto preformed or halogenated particles introduced into the reaction vessel. In this embodiment, the method of the present invention is used to produce only the annular particle regions containing silver, chloride, zolomide, and optionally iodide.

When the method of the invention is used to form only m-shaped grain regions, the halogenated plate forming the central region of the resulting grain is used to form the loam-like regions around the lateral periphery of the grain. Any halon composition having a melting point of pp1 that is comparable to or even lower than the bath solubility of the halogenated plate may be used. In a preferred embodiment of the invention, the halonide grains forming the central grain region are tabular and have a thickness not greater than the desired thickness of the finished tabular grain. The grains forming the central grain region may be of high aspect ratio, but need not have an aspect ratio greater than 1:1. The acceptable aspect ratio for the grains forming the central grain region will vary depending on the proportion of grains to be formed in the central region. For example, if the central grain area is to occupy 99 - of the entire grain, not only is it tabular, but the finished grain is 7:
It is clear that in order to exhibit an average aspect ratio of 1, it must also have an aspect ratio very close to 7:1. On the other hand, if the central particle region occupies only one part of the completed particles, the initial aspect ratio of the particles forming the t11 medium particle region may be 1:1, and the method of the present invention The chlorides and bromides present in the monkey-like grain regions during precipitation into the grains can readily produce tabular grains with an average aspect ratio of at least 7:1. The particular choice of halon composition for the central grain region and the proportion of the total grain occupied by the central grain region will vary depending on the particular photographic application.

By forming the loamy grain regions using the method of the invention, tabular grain silver halide emulsions of the invention are produced in which the central and oval grain regions have different halon compositions. You can. For example, tabular grain emulsions according to the present invention can be produced in which the central grain region is free of silver bromide and the chloride complex and bromide complex are present in the annular grain region. In certain embodiments, the central particle vM itself has an aspect ratio. It is possible to form a tabular grain silver iodine emulsion, and then form a trench-like powder emulsion containing monochemical mackerel and fuka mackerel according to the present invention. It is also possible to have a central particle with a composition mainly composed of sea bream. It can be used to make the aspect ratio darker.
4R does not necessarily have to be admired by the aspect ratio that is inevitable for photo-destructive particles. On the edge of the central grain field, chloride, noroid, and a-throat precipitate, forming a different kind of halodron, and the formation of Murako Ichijo. Halonide, which precipitates in the shape of the grain area a, precipitates on the platelet edge at the same time as the main face of the tabular grain is formed. Therefore, as C1 sedimentation progresses, the aspect ratio of the particles increases toward the east. Depending on the specific precipitate formation conditions of 4LC, some thickening of the 17-grain region may be experienced during precipitation. However, the deposition on the major faces of the tabular grains that are being formed is
Deposition, if any, on the annular edges of the tabular grains also occurs at low velocities.

Provided that the above conditions are met, the concentrations and rates of introduction of silver and halide salts may be similar to those conventionally used. A particularly preferred precipitation technique is to increase the rate of silver and halide salt introduction during the run to reduce precipitation time. The rate of introduction of silver and halide salts can be increased by increasing the rate of introduction of the dispersion medium and the silver and halide salts, or by increasing the concentration of silver and halide salts in the dispersion medium introduced. .

Although it is desirable to increase the rate of silver and halide salt introduction, U.S. Pat.
No. 2,900, No. 4.2 4 2,4 4 5
No. 2,107,118, European Mother Patent Application No. 80102242 and Way?
? ? y) and Strong, r Growth mechanism of AgBr crystals in gelatin solution (Gro
wthMsehanlsm of AgBr Crys
tals in GslatlmSolution)
J. Photographic Inc. Science and Ennonearing, Volume 21, I&1, January 1977-2.
Moon, p. It is particularly desirable to keep the introduction rate below a threshold at which the formation of new particle nuclei is likely to occur (i.e., to avoid h-nucleation) as taught in 14 et seq.

Modifying compounds can be present during the silver halide precipitate formation process. Such compounds may be initially present in the reactor or may be added to one or two
It can also be added along with the above salts. U.S. Patent No. 1,195,432, 1,9 5 1,9 3
No. 3, No. 2, 4 4 8, 0 6 0, Ki 2, 62
No. 8,167, No. 2, 9 5 0, 9 7 No. 2, No. 3
, No. 488,709, No. 3,737,313, No. 3,
7 7 2,0 3 1 and 4,269,927
Issue and Research Disclosure, Volume 134, 1
In June 1975, compounds of copper, thallium, lead, bismuth, cadmium, zinc, intermediate strength minerals (i.e. sulfur, selenium and tellurium), gold and Group II precious metals as described in Item No. 134. Modifying compounds such as these can be present during the silver rodanide precipitate formation process. Research Disclosure and its predecessor Product Licensing Index, UK, PO9-I
EF, no\nzo7ya. It is a publication of Harpando, Homewell, and Industrial Opportunities Limited. Moiday (Mois@r)
Yarnal Otsu Photographic Science, 2
5 volumes, 1977, PP. Tabular grain emulsions can be sensitized by internal reduction during the precipitation process as described in 19-27.

The respective silver and halide salts are described in U.S. Pat.
2 1,0 0 2, 3,0 3 1,3 0
No. 4 and Claes (Cla@s) et al., Photography Colles I Indents, Volume 102? , No. 10, 1967, P. surface or subsurface feed lines using a distribution device or using gravimetric feeding to adjust the distribution rate and adjust the pBr and/or PAg of the reactor contents as described in 162. can be added to the reactor through. Put the reaction mixture into the reactor, and add 17 minutes (not to mention, US special 1; 1 pay 2,9 9
6, 2 8 July, 161 No. 3,342,605, Doki 3, 4 1 5, 6 5 0, Doki 3, 7 8
5, 7 7 No. 7, same mackerel 4, 1 4 7, 5 5 1
No. 4,171,224, British Patent Application No. 1 2,022,431A, German Patent Application No. 2,555,364 and German Patent Application No. 2,555,6
, 8 8 No. 5 Research Disclosure l
166, February 1978, IDEM 16662 can be used. As specified in this specification,
r and pAg are defined as the negative logarithms of hydrogen, odor, and silver ions, respectively.

In preparation K of the tabular grain emulsion, the dispersion medium is initially placed in the reactor. In a preferred form, the dispersion medium consists of an aqueous dispersing solution of a peptizer. A peptizer concentration of 0.2 to about 101-0 based on the total AM of the emulsion components in the reactor can be employed to reduce the amount of HI to produce silver halide and the peptizer concentration in the reactor during production. Approximately 61 based on glue if all wit
It is a common practice to increase the emulsion vehicle concentration by keeping it below and adding emulsion vehicle from above to obtain optimum coating properties. The initially formed emulsion may contain from about 5 to 50 i peptizer per mole of silver halide, preferably from about lθ to 30 f peptizer.

By adding additional pickles later, it is possible to increase the sophistication to a high level of 91,000 per mole of halonide. Preferably, the vehicle concentration in the final emulsion is greater than 50 tons per mole of silver halide. During coating and drying during the production of photocopies, it is desirable that the vehicle occupy about 30 to 70 layers of the emulsion layer.

Vehicles (including both binders and peptizers) can be selected from those commonly used in the preparation of halogenated button emulsions. Preferred deflocculants are hydrophilic colloids, which can be used alone or in combination with hydrophobic substances. Suitable hydrophilic substances include proteins, protein*i conductors, such as cellulose conductors such as cellulose esdel, such as alkali-processed gelatin (cow or leather gelatin) or acid-processed gelatin (pig skin gelatin). Included are materials such as gelatin, gelatin carriers such as acetylated gelatin and phthalated gelatin. These and other vehicles are described in Research Documentation, Vol. 176, 1978.1.
February, item 17643. It is described in Section 1■. In particular, vehicle substances including hydrophilic colloids (as well as hydrophobic substances used therewith) are photographed according to the present invention.
! They can be incorporated not only in the first emulsion layer, but also in other layers such as upper layers, intermediate layers, and layers located below the emulsion layer.

Grain ripening may occur during the preparation of emulsions according to the invention. Because of its high solubility, silver geode is less affected by ripening agents than other silver halides.

Known halonated solvents are useful in promoting ripening. For example, it is known to have an excess of promide ions present in the reactor to promote ripening. It is therefore clear that ripening can be accelerated simply by introducing a bromide salt solution into the reactor. Other ripening agents can be used, and these ripening agents can be incorporated in their entirety into the dispersion medium in the reactor before the silver and halide salts are added, and one or more Halide salts, silver salts or peptizers can also be added and introduced into the reactor. As a further variant, the ripening agent can also be introduced independently at the halide salt and silver salt addition stages.

The tabular grain emulsions of this invention are preferably washed to remove soluble salts. Removal of soluble salts is carried out as described in Research Disclosure, Vol. 176, December 1978, Item 17643, Sexy Fengda, Kashirinaka, P. and/or by well-known techniques such as cryo-sedimentation and leaching.

In the present invention K, in order to avoid an increase in the thickness of the tabular grains, a decrease in the spectral ratio, and/or an excessive increase in the diameter, the ripening of the tabular grains is terminated after the precipitation is completed. It is particularly advantageous to clean the product between times. Prior to use, the emulsion with or without sensitizer is dried and stored.

According to the method for producing tabular open silver halide grains described above, the tabular grains satisfying the thickness and diameter criteria for the aspect ratio account for at least 3 of the total projected area of all the silver octalodenide grains.
Although it is possible to prepare tabular grain emulsions with aspect ratios as high as 5.5, it is recognized that greater benefits are achieved by increasing the proportion of such tabular grains.

It is desirable that tabular 71-hole silver grains satisfying the thickness and diameter criteria occupy at least 50 squares, preferably at least 70 squares (optimally at least 490 squares) of the total projection area. Although the presence of small amounts of non-tabular grains does not cause any interference in many photographic applications and still provides the benefits of tabular grains, the proportion of tabular grains can be increased. Large tabular silver oxide grains can be separated from small non-tabular grains in a grain mixture using conventional separation techniques such as centrifugation or hydrocyclones. Eight hydrocyclone separation is taught in US Pat. No. 3,326,641.

Once formed by the method of this invention, the tabular grain emulsions can be sheathed into core emulsions by techniques well known in the art. Any photographically useful silver salt can be used to form a sheath in the high aspect ratio tabular grain emulsions prepared by the method of this invention. Techniques for forming silver salt sheaths are described in U.S. Pat. No. 3,367,778;
No. 206,313, No. 3.3 1 7, 3 2 2, No. 3, 9 1 7, 4 8 5, No. 4. 1
5 0. 9 9 4, 4.1 8 4, 8 7
No. 7 and No. 4,184,878. Conventional sheathing techniques do not favor the formation of high spectral ratio tabular grains. This is because as sheath formation progresses, the average aspect ratio of the emulsion decreases. If favorable conditions for the formation of tabular grains exist in the reactor during the sheath formation process, as described in detail in the history of Jōki, it occurs preferentially at the ring-shaped or outer edges of the grains, and as a result, Aspect ratio does not necessarily decrease.

The high aspect ratio tabular grain single grain silver emulsions of this invention are chemically sensitized. Chemical sensitization is T. H. Ja
mes+the theory of the photographic
Process, 4th edition, McIlan, 1977. pp. 6
7-76, using activated gelatin, or as described in Research Disclosure, Vol. 120. April 1974, Item 12008, Research Disclosure, Volume 134, June 1975, Item 13452. U.S. Patent No. 1,6 2 3,4
9 9, same No. 1, 6 7 3.5 2 2, same No. 2.399.083, same No. 2.6 4 2.3 6
No. 1, No. 3.297,447, No. 3.297
, 4 4 6, 3.7 7 2.0 3 1,
Same No. 3,7 6 1,2 6 7, Same No. 3.8 5
'1,7 1 1, '3,565,633, '3,90 1,7 14 and '3,90
No. 4, 4 1 5 and British % pestle M1,315,755
pAg 5-10, p}15-8 and temperature 30-80 as described in No. 1,396,696.
C. using sulfur, selenium, tellurium, cauldron, platinum, radium, iridium, ospaum, rhodium, rhenium or phosphorus sensitizers or combinations of these sensitizers. Chemical sensitization is performed in the presence of thiocyanate compounds, as described in U.S. Pat.
5 2 1, 9 2 6, 3.0 2 1.2
The method is carried out in the presence of a sulfur-containing compound of Tide described in No. 15 and No. 4,054,457K. Finishing (Chemical Sensitization) Chemical K sensitization can be performed in the presence of modifiers. Finishing modifiers used include azaindene, azapyridine, azapyrimidine, penzothousazolium salts, and sensitizers with one or more heterocyclic nuclei that suppress capri during the chemical sensitization process. Compounds known to increase sensitivity and increase sensitivity are used. Examples of finishing modifiers are US Special Fraud No. 2,1 3 1,0 3
No. 8, No. 3.4 1 1, 9 1 4, No. 3.
554.757, Canadian Patent No. 3,565,631 and Canadian Patent No. 3.901,714, Canadian Patent No. 778
．． No. 723 and Duffin + 7
ttographic emulsion. N. Kebastory, Focal Zores (1966), New York, pp. 1
38-143. In addition to or as an alternative to chemical sensitization, hydrogen reduction, for example, as described in U.S. Pat. It can be sensitized, and US Pat. 2.5 1 8, 6 9 8
No. 2.739.060, No. 2,7 4 3.
1 8 2, 2,743.183, 3.0
2 6, 2 0 3 and 3.361, 564
stannous chloride, thiourene dioxide,
using dentifrice agents such as PolyRyomin and Ryoingolan, or with low pAg (e.g. less than 5) and/or high pH.
(For example, 8 or higher) Reduction sensitization can be achieved by treatment.

1. U.S. Patents M3.9 1 7, 4 8 5 and 3
Surface chemical sensitization can be performed, including subsurface sensitization as described in , 966.476.

In addition to chemical sensitization, the high aspect ratio tabular grain chloride steel emulsions of this invention can be spectrally sensitized. In combination with high aspect ratio tabular grain emulsions, spectral sensitizing dyes having absorption maxima in the blue and minus blue (i.e., green and red) portions of the visible spectrum can be used. Additionally, in special applications, spectral sensitizing dyes can be used to improve spectral sensitivity beyond the visible spectrum. for example,
It is possible to use infrared absorption spectral sensitizers.

The emulsions of this invention can be spectrally sensitized using a variety of dyes. Dyes that may be used include cyanines, merocyanines, complex cyanines and complex merocyanines (i.e., tri-, tetra-, and polymononuclear myrionins and merocyanines), oxonol, hemioxonol, styryl, merostyryl, and strenotocyanine. Contains polymethine base.

The spectral sensitizing dyes include quinolinium, pyridinium, inquinolinium, 3H-indolium, and benzene.
●] Indolium, oxazolium, oxazolinium, thiolizolium, thiolzolinium, selenazolium, selenazolinium, ibadazolium, imidazolinium,
Penzoxazolinium, penzothiazolium, penzoselenazolium, penzimidazolium, naphthoxazolium, naphthothiolizolium, naphthoselenazolium, thiolizolium, nohydronaphthothiolizolium, pyrylium and imidazovirazinium Two radical heterocyclic nuclei linked by a methine linkage, as derived from a quaternary salt, are included.

Melon Ryonino spectral sensitizing dyes include parbituric acid, 2-
'y-opalbituric acid, rhodanine, hintoin,
2-thiohydantoin, 4-thiohydantoin, 2-vilazolin-5-one, 2-inxazolin-5-one,
Indane-1,3-noone, cyclohexane-1,3-
44 from dione, l,3-zoxane-4.6-none, birazolin-3.5-none, bentane-2.4-none, alkylsulfonylacetonitrile, malonitrile, inquinolin-4-one and chroman-2,4-none It includes a combination of an acidic nucleus and a cyanine dye-type basic multicyclic nucleus through a methine bond.

One or more spectral sensitizing dyes can be used.

Dyes are known that have maximum sensitivity at wavelengths throughout the visible spectrum and have spectral sensitivity curve shapes with great variety. The choice and relative proportions of dyes will depend on the spectral domain for which sensitization is desired as well as the desired shape of the spectral sensitivity curve. Dyes with overlapping spectral sensitivity curves often exhibit a combined shape of the curves in which 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 dyes having different maximum sensitivities, a spectral sensitivity curve having a maximum value midway between the maximum sensitivities of the individual dyes can be obtained.

Multiple spectral sensitizing dyes can be used in combination, thereby producing supersensitization, that is, greater sensitization in a given spectral region than if one of the spectral sensitizing dyes were used at any concentration in the spa. Also, large spectral sensitization is achieved due to the additive effects of these spectral sensitizing dyes. Supersensitization involves the use of spectral sensitizing dyes and other additives (
(e.g. stabilizers and anticapri agents, dust image promoters or inhibitors, coating aids, fluorescent brighteners and antistatic agents)
achieved by a selected combination of Several mechanisms and compound K that may be responsible for supersensitization are described in Gilman's overview of the supersensitization mechanism.
(Ftevisw of th@Mechanimms
ofSupersens tzatlon) J, Photographic Science and Engineering, Volume 18, 1974, pP. 418-43
It is listed in 0. Spectral sensitizing compounds also shade the emulsion in other ways. In addition, the spectral sensitizing dye may be an 80rn acceptor or an electron acceptor as disclosed in U.S. Pat. No. 2,131,038 and U.S. Pat.
Acts as an antifoggant or stabilizer, fjlg1 promoter or inhibitor.

Among the spectral sensitizers useful for sensitizing external silver oxide agents are Research Disclosure, Vol. 176. 197
In December 1988, item 17643 was published in Sexy 1 ■. When iodide is used for rounding to improve spectral sensitization, it can replace the halide present on the grain surface, thereby converting the grain to a silver iodide grain.

Amounts of dyes conventionally used for spectrally sensitizing emulsion layers containing nontabular or low aspect ratio tabular silver octane grains can be used. To provide the full benefits of the present invention, an optimal amount (i.e., an amount sufficient to achieve at least 60 ts of the maximum photographic sensitivity achievable from K grains under the exposure conditions) of spectral sensitizing dye is added to a high aspect ratio. It is desirable to absorb it on the grain surfaces of tabular grain emulsions. The amount of dye used will vary based on the particular dye or combination of dyes used and the particle size and aspect ratio. Optimal spectral sensitization is achieved when using organic dyes in monolayer coatings corresponding to about 25 to 100 or more of the available total surface area of surface-sensitized silver halide grains. This is known in the photographic field. That is, this means that, for example, the waist (
We m t et al., “The Adsorption of Sensitizing Dyes in Photographic Emulsions”
Ising Dyes InPhotographic
Emulsions) J. Journal 6 of Physical Chemistry. Volume 56. p-1065,195
2: Spence et al., “Desensitization of sensitizing dyes (
Dessns1tzation ofSnsitiz
ing Dye@)J+Journal Ozo Physical and Colloid Chemistry. Volume 56, No. 6. June 1948, pp. 1090-1103: and U.S. Special Fraud No. 3.9 7 9. -2 1 Described in No. 3. The optimal dye concentration level is Mee
a) Theory of the Photographic
Process, 1942, Macmillan, pp. 106
7-1069. This method is chosen from the method K taught by.

Spectral sensitization can be carried out at any stage of emulsion preparation known to be useful. Most commonly, spectral sensitization is performed subsequent to completion of chemical sensitization. However, U.S. Patent No. 3. 6 2 8, 9
Spectral sensitization can be performed simultaneously with chemical sensitization, as taught in No. 60 and No. 4,225,666K, or it can be performed entirely prior to chemical sensitization;
The K spectral sensitization can also be started before the completion of the silver gunide grain precipitation formation. As taught in U.S. Pat. However, it is possible to introduce the remainder after chemical sensitization. US patent! Unlike No. 4,2 2 5, 6 6 6, spectral sensitizing dyes can be added to the emulsion after the 80 part silver halide has been precipitated. Sensitization can be achieved through pAg regulation, including circulation during chemical and/or spectral sensitization. can be increased. An example of PAN adjustment can be found in Research.
Disclosure, Volume 181. Listed in May 1979, Item 18155.

In one preferred form, the spectral sensitizer can be incorporated into the emulsion according to the invention after completion of the formation of the silver octoffide precipitate and before chemical sensitization. Also, in some cases similar results have been achieved by introducing other adsorptive agents, such as finishing modifiers, into the emulsion prior to chemical sensitization.

Independently of the prior incorporation of the adsorbent Qf-capable substance,
It is desirable to use about 2.times.10@-' to 2 moles of naocyanate based on silver during the chemical sensitization process as taught in U.S. Pat. No. 2,642,361. Other ripening agents can also be used during the chemical sensitization process.

A third technique, in combination with or independently of either or both of the techniques described above, is to provide a spectrally sensitized high aspect ratio tabular grain emulsion to one of the tabular grains.
Alternatively, chemical sensitization is preferably carried out at two or more predetermined separate positions. It is believed that chemical sensitization can occur selectively on different crystal surfaces of the tabular grains because the spectral sensitizing dye is preferentially adsorbed on the crystal surfaces forming the main surfaces of the tabular grains. Deposition of silver octide at the corners of the tabular grains, which occurs with selectively absorbed dye, increases the sensitivity of the grains, and conventional chemical sensitization can then increase the sensitivity of the emulsion.

Although not necessary to achieve all advantages, the emulsions of this invention are optimally chemically and spectrally sensitized according to typical practical manufacturing methods.

That is, it is desirable to achieve a sensitivity equivalent to at least 60 degrees of the maximum Log sensitivity achieved from those particles in the sensitizing film range under normal use and processing conditions. Here, Log sensitivity is 100(1-Ao
gE), and in this formula, E is the exposure amount expressed in meters-candle-seconds at a density of 0.1 on Capri. Once the silver octide grains in the emulsion layer have been characterized, it is no longer necessary to determine whether a product is optimally optically and spectrally sensitized with respect to comparable products from other manufacturers. This can be determined through analysis and performance evaluation. To achieve the sharpness advantages of the present invention, it is immaterial whether the silver octaronide emulsion is chemically or spectrally sensitized efficiently or inefficiently.

Once tabular grain emulsions have been formed by the precipitation method as described above, washed and sensitized, their preparation can be completed by incorporating commonly used photographic IIJ≦additives. can. They can then be applied in photographic applications where silver images are to be produced, for example in conventional black and white photography.

Photographic materials having emulsions according to the invention intended to form silver hazes can be sufficiently hardened that no additional hardeners need to be incorporated during processing. This hardening increases silver coverage compared to photographic elements using tabular grain emulsions that are similarly hardened but have a lower aspect ratio than the non-tabular or high aspect ratio. Can be done. In particular, the high aspect ratio tabular grain emulsion layers and other hydrophilic colloid layers of black-and-white photographic elements can be hardened to a degree K sufficient to reduce the degree of swelling of those layers to less than 200 inches. Here, the degree of swelling is determined by (a) maintaining the photographic element at 38° C. and relative humidity of 50° C. for 3 days, (b) measuring the layer thickness, and (c) maintaining the photographic element at 20° C.
Determined by immersion in distilled water at 0.degree. C. for 3 minutes and then (d) measuring the change in layer thickness. Although it is particularly desirable to harden photographic elements intended for the formation of a silver border to a degree that requires the inclusion of a hardener in the processing solution, the degree of hardening of the emulsions of this invention is not limited to any conventional use. It may be at a certain level. Furthermore, it is also possible to incorporate hardeners into the processing liquid, which is particularly useful in relation to the processing of radiographic materials, for example in Research Disclosure, Volume 184, August 1979, Item 18431, It is described in Section K.

A typical compound hardener (pre-hardener) is Research F4
Scrooger, vol. 176. December 1978. It is listed in Item 17643, Section X.

Research Disclosure, Volume 176. Stabilizers as described in December 1978, Item I 7643, Section M. Incorporation of antifoggants, antikinks, latent image stabilizers, and similar additives into the emulsion and adjacent layers prior to coating increases the minimum density (i.e., capri) in negative-working emulsion coatings or directly into positive-working Instabilities that would increase the minimum density or reduce the maximum density in emulsion coatings can be avoided. C. E. K. Mass *The theory op des photographic noroses, ed. 2nd edition, Macmillan, 1954, pp. Many of the effective anti-cazzing agents in Emulsion K can also be incorporated into dust images and can be classified under a few general headings, as described in US Pat. No. 6,777-680.

When aldehyde tizo hardeners are used, the emulsion layers can be protected by conventional anticapri agents.

In addition to sensitizers, hardeners, and anticaprilants and stabilizers, various other commonly used photographic additives may be present. The specific selection of additives used will depend on the characteristic K of the photographic application and can be easily accomplished by one skilled in the art. Research Disclosure for useful additives for plants. 176, 1, December 1978, Idem 1764
3. Same document item 17643. Vl
Fluorescent brighteners can be incorporated as described in JK. Absorbing and scattering materials can also be used in separate layers of emulsions and photographic elements according to the present invention, as described in Section 2 of the same document. Coating aids as described in Section X and plasticizers and detergents as described in Section X may also be present. An antistatic layer can be present as described in section (2). The method of adding additives is described in Section W. A matting agent may be added as described in Section K. If desired, developers and development modifiers can be formulated as described in Section Xx and Section X.

Photographic elements containing emulsions according to the present invention, when used in the field of radiography, may be specifically incorporated into the emulsions and other layers of radiographic elements by reference to Research Disc Noyer, Item 18431. It is also possible to take the form of

The emulsions of this invention and the presence of other commonly used silver octide emulsion layers, interlayers, overcoats, and subbing layers in photographic elements are disclosed in Research Disclosure. Volume 176, December 1978, Item 1 7
6 4 3. XVr1IK can be coated and dried as described.

Blending the high aspect ratio tabular grain emulsions of the present invention with each other or with commonly used emulsions in accordance with established practice among those skilled in the art will thus satisfy the properties required for a particular emulsion layer. I can do it. for example,
By blending a large number of emulsions, the characteristic curve of the photographic material can be adjusted to suit a given purpose. ! Lend K can increase or decrease the maximum density achieved by exposure and processing κ, reduce or increase the minimum density, and make the shape of the characteristic curve congruent between toe and shoulder. . For this purpose, the emulsion according to the present invention was prepared in the above-mentioned Research Disclosure Vol. 176, 19.
It can be blended with commonly used silver octacrocin emulsions such as those described in December 1978, Item 17643.1. In its simplest form, a photographic element employing an emulsion according to the present invention comprises a single emulsion layer containing a tabular grain silver bromochloride emulsion according to the present invention and a photographic support. Of course, two or more silver halide emulsion layers as well as overcoats, subbing layers and interlayers may be included. Instead of blending the emulsions as described above, similar rice efficacy can be achieved by coating each of the emulsions to be blended as separate layers. Coating the emulsion layers separately to obtain exposure latitude is well known in the photographic art, as described by Zelikman (Z@11kman) and Levy (Ls▼1), Making and Coating.
Photographic emulsion. focal glare. 1964, pp. 234-238, U.S. Patent No. 3,662,228 and British Patent No. 923
, No. 045. In addition, blend high-speed and low-speed emulsions? It is also well known in the photographic art that photographic sensitivity can be increased by coding in separate layers rather than in separate layers. Usually, a high-speed emulsion layer is coated at a position closer to the exposure source than a low-speed emulsion layer. This technique uses 3 or more M) emulsions
It can be applied to products made by IIl. Such a layer structure is also useful in implementing the emulsion according to the present invention. The layers of the photographic element can be coated onto the support of choice. Typical support materials include summer coal films, wood fibers (e.g. paper), metal sheets and foils, glass and ceramics, and wood support materials, which improve the adhesion of the support surface and the anti-banding properties. One or more subbing layers may be formed to improve dimensional stability, abrasion resistance, hardness, friction properties, antihalation properties, and/or other properties. These supports are well known in the art and are described, for example, in Research Disclosure, 1764. December 1978. Item 17643
．． It is described in Section X■.

Single or multiple emulsion layers are usually paired with flat primary surfaces.
is coated as a continuous layer on a support having, but need not necessarily be, a continuous layer. The emulsion layer can be coated as a plurality of 1-segments with lateral K displacements onto a flat support surface. When using one or more emulsion layers as segments, it is desirable to use a microporous support. Useful microporous supports are disclosed in PCT Application Publication No. W.
O8Q/01614 (Published on August 7, 1980;
Belgian Patent No. 881,513. (Corresponding to August 1, 1980) and US Pat. No. 4,307,165. The size of the micropores can be 1 to 200 micrometers in width and 1000 micrometers or less in depth. In general, in the field of normal black and white photography, especially when enlarging photographic images, the size of the micropores is preferably at least 4 micrometers wide and less than 200 micrometers deep, with the best size being both wide and deep. Also about lO~
It is 100 micrometers. The photographic element carrying the emulsion of the present invention can be imagewise exposed by any method that can be used.This is described in the above research. Disclaw Noyer, Item 17643. Friend, please refer to section X. In particular, Genmei Yomoto is
It is useful when performing imagewise exposure using electromagnetic radiation in the spectral region in which the spectral sensitizer present exhibits maximum absorption.

Photographic Element K When recording blue, green, red, or infrared exposures, a spectral sensitizer is present that absorbs in the blue, green, red, or infrared portion of the spectrum. In the field of black and white, it is desirable to orthomatically or achromatically 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). High or low intensity exposure, intermittent or continuous exposure, exposure times over relatively short periods of minutes to milliseconds to microseconds, and solarization. All exposures, including light exposures at room temperature, high or low temperatures, and/or normal, high or low pressures, are described in T.H. 1977, No. 4.6.17.
As described in Sections 18 and 23, they can be used within the useful sensitivity range determined by conventional cytometry techniques.

The photosensitive silver fluoride contained in the photographic element is prepared by combining the silver fluoride with an aqueous alkaline medium in the presence of an alkaline medium or a developer contained in the photographic element following exposure to light. It can be processed according to conventional methods to form a visible image.

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

The above-described copying techniques for producing blank silver images can be readily applied to producing color images using colored books. Perhaps in the most advanced technique of obtaining ridged images, commonly used dyes can be incorporated into the support of photographic dyes, and as mentioned above, the shape of the silver image can be improved. I can do it now. In the area where the bulge is formed, the photographic material is actually no longer light-transmissive, and in other areas the support is transparent.In this way, The same effect can also be achieved by using another dye filter I or a dye filter layer and a transparent color filter. .hJc can be done., Silver octalogonide ^ * element is F!!.It can be used to form a dye image by the recessive destruction or formation of the element.The above-mentioned penance can be formed. The photographic materials used for this purpose are as described in Research Disc. No. 4, Volume 176, December 1978, γ IDEM 17643. Shima, Section D, using a 56-color image forming agent such as color canola. It can be used to form a color*ii by using a developer that is 1. In such a form, the developer reacts with the coupler in its acetylated form (combing). and a color dust image agent (eg, a primary aromatic amine) that can be used to form a dye image.

The dye-forming coupler can alternatively be incorporated into the photographic coupler according to conventional methods. The color nest-forming kaglar can be incorporated in different amounts to achieve different photographic effects. For example, the m degree of the coupler with respect to the amount of silver coverage can be limited to less than that normally used in speed and intermediate speed emulsion layers. Dye-forming couplers typically contain subtractive primaries (i.e., yellow,
Magenta and cyan) are selected to form monolithic dyes, and these cassolers are non-diffusible colorless cassolers.

Dye-forming cazolers with different reaction rates in different parts of a single straddle can be used to achieve the desired effect in a particular photographic application.

A dye-forming cazoler can be used as a development inhibitor or accelerator, a whitening accelerator, a developer, a toner, a diluting compound, a capri agent, an anti-capri agent, a competitive coupler, Releases photographically useful fragments such as chemical or spectral sensitizers and desensitizers. Development inhibitor releasing (DIR) canolers are well known in the industrial arts. They are non-dye-forming compounds that release a fraction of photographically useful groups upon fogging, as described in US Pat. No. 4,248,962, as well as color-forming couplers. Color present 1iI that can be transformed! DIR compounds that do not form pigments when reacted with radish can also be used.

Silver halide emulsions, such as Ritnoman emulsions, which have poor specific photosensitivity, were utilized as interlayers and overcoat layers to prevent or suppress migration of dust suppressant fragments.

The dye elements can be incorporated with colored dye-forming couplers such as the colored dyes JK-forming cazolers and/or competitive Kapfu used to form negative color imaging layer masks. Photo 1! An image color book stabilizer can be added to the base.
It is described in item 17643, section ■.

A dye image is formed by employing a method of using an oxidizing agent and/or a peroxidizing agent to form an inert transition metal ion complex in combination with a colored OiIl image-forming reducing agent. or can be amplified. The photographic element is particularly suited for forming dye 1 [l11 images.

Dye images can be formed on photographic elements by negative selective destruction of dyes or dye precursors, such as the Kinichi dye-white method.

Removal of developable silver by Ippaku is a common practice in the technique of forming colored images on photographic materials. Removal of such silver can be accelerated by incorporating bleach accelerators or precursors thereof into the processing solution or into certain layers of the photographic element. In some cases, in particular the color index I1ilIlgII. as mentioned above. When amplifying the
The silver particles formed by development are small compared to the amount of dye produced. Therefore, Gin-Oki-Haku is omitted because it has no obvious meaning in terms of humor.

In still other ratios, the @ image is held and the pigment is used to increase the density delivered to the plate of ζ or to fill the edge. When the density of the image is corrected with arsenic, it is usually desirable to take advantage of the color nests of the wake ridges that can produce a neutral image t- as a whole of a single neutral ω table.

Honmaru Akira products can be used to produce melancholy photographic images. In general, any conventional multicolor r# element containing at least one octalodenated edge emulsion layer can be improved simply by the addition or replacement of the gamma spectral tabular grain emulsion of the present invention. It is Noh. This technique is applicable to both additive polychromatic images and subtractive polychromatic images.

First, to explain the application of the present invention to additive polychromatic images, in combination with a compound containing an emulsion according to the present invention, which can be related to cypress, internal spiders, green and Filter devices enriched with red filter elements can be used.・
The aspect ratio tabular grain emulsion of the present invention which is chromatically exposed and forms one layer of the A-grain pattern is imaged through an additive primary filter system.

It has been treated to produce silver iron, and when viewed through a filter, a multicolored image can be seen. Such images are best viewed by projection. Therefore, both the donor element and the filter pupil have or share a transparent support.

fJ! Application of the emulsions of this invention in multicolor photographic elements in which multicolor images are produced by combinations of k-method primary image-forming dyes can provide particular advantages. ``Such photographic elements typically include a support and at least three overlapping dyestuffs that separately record the developing, green, and red light as yellow, magenta, and cyan dye images, respectively.
It consists of a set of...silver emulsion layers.

Although only one aspect ratio tabular grain silver chloride emulsion as described in the above is required, the multicolor photographic element contains at least 381 separate emulsions for recording each blue, green, and red element. . Emulsions other than the required aspect ratio tabular grain green or red recording emulsions may be in shapes such as those for normal use. Tomojo's emulsion is the glue 1 above.
- Disclosure, Item 17643.1. two or more emulsion layers are spectral blue;
Green and/or part 8i. ．． :M is given for at least sensitivity v? It is preferred that the higher emulsion layer be colored with a high aspect tabular grain emulsion as described above. Of course, give it! It has been established by PJT that it is advantageous to use tabular grain emulsions according to the present invention in total of ten layers of the emulsion layers, edge and red.

Multicolor photographic applications are often described in terms of color-forming layer units. The common multicolor photographic system of frogs also contains three overlapping color-forming layer units, and each color-forming layer unit can record a different IA of the spectrum, and is a subtractive color-mixing primary color. At least one silver emulsion capable of producing a dye image is included. That is, l', green, and red color-forming layer units are used to produce yellow, magenta, and cyan color patterns, respectively. The dye image-forming material does not necessarily have to be present in any color-forming enhancement unit and can be supplied entirely from the processing solution. When a dye image product is provided in a photographic element, it can be placed in an emulsion layer, and an electron transfer agent may be used as a development aid for image formation from the edge emulsion layer of the same color-forming layer. can be placed in a layer positioned to receive the Scavengers are commonly used to prevent color degradation due to migration of oxidizing gII or kase transfer agents between color-forming layer units.

Scavennowers can be incorporated into the emulsion layer itself as taught in U.S. Pat. No. 2,937,086 and/or U.S. Pat. No. 2,336,327.
Intermediate layer f: can also be arranged between adjacent color-forming layer units as described in No. Although each color-forming layer unit can include a single emulsion layer, emulsion layers with different photographic speeds of d2, 3 or higher are often provided in a single color-forming layer unit.
If it is not planned to arrange a plurality of multicolor emulsion layers with different 7'5i desired layer compositions in a single color-forming layer unit, the sacrificial number (usually 2 or 3)
It is common to provide blue, green, and/or red color-forming layer units.

The multicolor copy X cost A may be in any commonly used form as long as it satisfies the above requirements. Gorokovsky
hoviki i) r Spectral Sme f” is・
Of de photographic grosses, focal nore; <, 2. Ej-k, p. All of the six layer arrangements listed in Table 27m are suitable for adoption. To simplify and #3, in the preparation process of commonly used polychromatic silver oxide photograins, the minus blue part of the spectrum TCG
A high aspect ratio flat plate of 1'* or 2 or more so as to receive the radiation before the other layers. A grain emulsion layer with a grain size of ζ is formed. however,
In the case of large or low grains, it is desirable to modify the 11 configuration as necessary and replace the conventional negative blue recording emulsion layer with a negative blue recording emulsion layer having a tabular grain aspect ratio of 1 or 2 or more. Other layer arrangements will become clearer with reference to the preferred examples below.

In the above, B, G, and R are the normal type of recording color forming layer ratio 'k4<, respectively,
A T in front of a color-forming layer unit B, G, or R indicates that the emulsion layer contains a tabular grain emulsion such as fc, as described in more detail above, and the color-forming layer unit B. F in front of G1 or R is a photograph in which the color-forming layer unit is higher than at least one other color-forming layer unit that has the same level of color formation in the same 1/3 of the spectrum in the same layer order arrangement. S indicates that the color-forming layer unit has a sensitivity, and an S before a color-forming layer position B, G, or H records exposure in the same third of the spectrum in the same layer position. at least 1
The IL is shown to have a lower photographic sensitivity than the other color-forming layer units, except that the IL carries a scattering agent, but does not include an intermediate layer that is substantially free of yellow negative filter material.

Each color-forming layer unit of high or low sensitivity, due to the position it occupies in the layer configuration, is different from other color-forming units that register exposure in the same third of the spectrum. They can differ in their photographic sensitivity, inherent sensitivity characteristics, or a combination of both.

Layers: In one-position orientations 1 to 2, the position of the support is not indicated. According to convention, the support will in most cases be located in the position closest to the source, i.e., in the first layer. If the support is colorless and specular or transparent, then 1'yt. Between the source and the indicated layer V
There may be C. More generally, the support can be placed between the light source and the color-forming layer unit for recording the light to which the support is transparent.

A multicolor photographic emulsion consisting of a combination of color-mixing original basoplasts is usually made by combining color cord-forming materials such as dye-forming cassoplars to increase the number of nuclei that combine. Jl'k, but the and 7+ are no longer necessary.・A silver halide emulsion and a complementary color subtractive primary color system can be formed to record light in 1/3 of the optical spectrum, respectively.
The material is called Bakenoto, and the three color-forming ingredients are multicolored! It can be put together during the photo shoot of JX to generate the image. Typical mixed and multicolor photographic compositions are disclosed in US Pat. No. 2,698,794 and US Pat.

The high aspect ratio tabular silver chloride emulsions of this invention are advantageous because they exhibit less high angle light scattering compared to non-tabular and low aspect ratio tabular grain emulsions. This can be determined quantitatively. In FIG. 6, a sample of emulsion 1 according to the invention is coated on a transparent (specular) support 3 in a silvered crossbar of 1.08 #/m@2. Although not shown, the emulsion and support are preferably immersed in liquids having practically balanced refractive indices to reduce the Fresnel reflection ei at the surfaces of the support and emulsion. The emulsion layer is patterned by Motogen Hirakura 5 at right angles to the plane of the support. Light from the light source following the path indicated by point -7 forming the optical axis strikes the IL agent layer at point A. Light passing through the support and emulsion can be detected at a fixed distance from the emulsion at a hemispherical detection surface 9. The maximum intensity level of light is extracted at point B, which is at the intersection of the initial optical path extension and the detection hexagon.

An arbitrarily selected ttk point C is marked on the Chieda surface in FIG. The point between A and C can be changed from υφ2o to 90' by moving point c5, which forms an angle φr with respect to the emulsion layer, t above the surface of the emulsion layer. San*.
By measuring 551 degrees of i as a function of the angle φ, the cumulative element 4tie can be determined as a function of the angle φ (this is because the light scattering around the element @7 is a rotational pair). ).

We will give a self-explanatory explanation of cumulative light scattering, and then we will discuss de Lumma (
Depalmm) and Yayasu l+ - (Gas
per), 1 Measuring the optical properties of emulsions using the Monte Carlo method (Determining the Opt
ical Proper eyes @I orPhotogra
phic Emulsion@by the Mont
eCarlo Method) J, Photographic Science and Engineering, Volume 16, No. 3, 1971. Cattle May-June, 1″81-191t
Please refer.

After determining the summation element 41 as a function of the angle φ at the value of O to 90° for the emulsion 1 in the fourth part of the present invention, the other parts of the support 3 were decorated with the same button opening. Same operation using regular emulsion with same average grain volume? repeated. Up to 70° (80° in some cases) to the Emalnoyon of the two gods.
In the relative softness of the cumulative light distribution as a function of the month φ with respect to the value of φ (up to and above), the emulsion according to the invention has less scattered light iu. In FIG. 6 -C, the angle θ is shown as a component of the angle antiφ. The angle of scattering is referred to herein as C, with respect to the angle θ. Therefore, the high aspect ratio tabular grain emulsions of this invention exhibit lower high angle failure. Due to the excessively low sharpness of the high-angle 11°-1 unit, Akira Motomoto's sieve aspect ratio tabular grain emulsion can give a sharper image 111k in that case. So it's a must.

As shown here, the candy called ``Kumego angle'' means that half of the light coming from the test i + J clothes surface V forms an angle θ around the polar axis of the line AC.
The angle θυ is set within the area defined by the cone formed by rotating it with the angle θυ such that it falls within the area defined by the cone formed by rotating it, while hitting the detection surface other than the half of 9 or the 9 glen area that corresponds to the detection table. .

According to the present invention, the orchid aspect ratio semi-plate-like ductal breast wound is 5-lowered and high-angle with a special burying tool.
I don't mean to be rude, but if you have a flat main axis crystal circumference provided by pseudomorphic particles with an aspect ratio, you can observe the arrangement of Chengzi during the Japanese siege. It is thought that this improves the parking level by 10. It is said that the tabular grains present in the surface of silver halide A are flat on the surface of the support F1. Therefore, light directed at right angles to the photographic grain, which corresponds to the Eika layer, hits tabular grains at 11 angles to one main crystal ■15. If the tabular grains are thin, the -1 direction when they are coated means that the aspect ratio of the tabular grains fL of this older brother is actually thinner than that of the normal drilling layer. *nsLX This can also give a sharpness of 20 degrees.However, since the emulsions 1- of this invention have a sharpness of 20 degrees even when they are coated to the same thickness as the conventional emulsion 1-. Improving is a waste.

In certain preferred embodiments of this invention, the high aspect ratio tabular-autumn grain (Okuchika silver) emulsion layer is at least 1.
0 micrometers, most preferably at least 2
Shows the small average particle diameter in micrometers. Improved sensitivity and sharpness are both achieved as the average particle size is increased. The maximum effective average particle diameter is
The maximum average grain size of the aspect ratio tabular af emulsions according to the present invention is in all cases 30<0, although it will vary with the granularity that can be tolerated for II11 forming applications. It is smaller than 10 microns, optimally larger than 10 microns.

By a single layer coating of a tabular grain emulsion with a cylindrical aspect ratio according to the heather invention VC. Although it is possible to obtain reduced gathering angles, low gathering angles are not necessarily achieved in multicolored coatings. In some multicolor coating formers, increased sharpness can be achieved with the high aspect ratio tabular grain emulsions of this invention. However, in other multicolor coating formers It can be seen that the low aspect ratio tabular grain emulsions of this invention have a lower IlI sharpness at the edge of the underlying emulsion layer.

Looking back, I was ranked 1st place by 1k - Nateru! It can be seen that the recording emulsion 1- is located closest to the source of Fukuro's radiation, while the green recording emulsion 1- below the yellow is the tabular grain according to the present invention. This green recording emulsion layer, on the other hand, overlies the red recording emulsion layer.

Evening recording emulsion layer is normal for many non-tabular emulsions.
. If particles with average diameters in the range 2 to 0.6 micrometers were included, they would have a large scattering of 9, which is suitable for green and red iSf tags, respectively. If unfortunately the light is swarmed by the cocoon reaching the high aspect ratio tabular rice grain emulsion in the green recording emulsion, the tabular grains will pass through the light reaching the red recording emulsion. Normal “I”
L. Soeri also pardoned him to a much higher degree. i sometimes make it happen. This particular choice of emulsion and layer arrangement therefore improves the sharpness of the red recording emulsion layer to an even greater extent than if this older emulsion were not present in the 71 rVn1 configuration. It will lower the

In order to fully realize the sharpness benefits in the underlying tabular grain emulsion layers of the present invention, it is preferred that the tabular emulsion layer be positioned so that it receives light without obvious scattering ( A position that receives substantially purely theoretically transmitted light is preferred). In other words, improvement in sharpness in emulsion layers under tabular grain emulsion enhancement is best realized only when the tabular grain emulsion layer is not itself under turbidity enhancement. For example, if the tabular grain green recording emulsion layer is above the red recording emulsion 1- and below the Rizzoman emulsion j-1 and/or the high aspect ratio tabular grain recording emulsion layer of this invention, The sharpness of the red recording 4L recording layer will be improved by the presence of the overlying tabular grain emulsion layer. If the angle is less than about 10°,
An improvement in the sharpness of the red emulsion layer is obtained. Of course, as far as the salmon button 1 above is concerned,
It is not certain whether the red DJI agent layer itself can be combined with the tabular grain emulsion layer according to the present invention.

In the case of multicolor emulsions in which the density formation rate is all the same, at least the emulsion layer closest to the light emission is composed of tabular grains.
Advantages of freshness lf: Preferable to belittle. In a particularly preferred embodiment, each emulsion layer that is closer to the source than the other image recording sources is a tabular grain emulsion layer. The above-mentioned layer j first rank ■, ■, ■, ■, ■
and () are examples of one arrangement of multi-layered photographic elements that can clearly increase the density of the underlying emulsion layer.

The advantageous effect of tabular grain silver halide emulsions on the image sharpness in multicolor photographic elements has been specifically discussed in relation to multicolor photographic materials, but the advantages of sharpness are You can also pray in the multi-layered black and white photographs that are created. Black and white painting 17 k Emulsion T pan 1 degree and low sensitivity 1
It is normal to divide into −. When used in a semi-platelet emulsion according to the present invention, which is as close as possible to a#i, the sharpness of the underlying emulsion layer will be improved.

(d) Embodiment The present EJ8 can be better understood by reference to the specific examples in Example Y. In each example, the contents of the reaction vessel were was vigorously stirred through.

rToJ's eyelids are 9wt.yascenttt unless otherwise specified, "M" is rj1I is 7 ruift- unless otherwise noted, "N" is candy is All solutions are water bath solutions unless otherwise noted.

Example l 3% gelatin at 55°C with vigorous stirring, 0.47M potassium chloride, 'o. A 1.72M potassium bromide solution (potassium chloride 1.24M) and 2. Added 6k of OM Ship #R silver solution and kept the pAg read before starting the halide and silver additions (3k of total silver nitrate used).
．． Consumes 8 Yu). The addition of the two solutions was then continued in an accelerated flow (3 times faster from start to finish, i.e. 3 times faster at the end than at the beginning) for 64 minutes, during which time the pAg was kept unchanged, and the total nitric acid used was 96% .2% consumed6
It was. The molar ratio of chloride and chloride ions in the reaction vessel during precipitation was kept constant at 0.48 M, and the molar ratio of chloride to chloride ions was 47:1. In the past, 4 moles of silver nitrate were mixed in 1. Next, the sacrificial preparation was drained and coagulated using the method described in US Pat. No. 2,614,929.

In Figure 1, there was chlorinated milk from shellfish containing an extremely high proportion of tabular grains. The tabular grains occupied about 809b of the total projection area of the grain. The average aspect ratio of the emulsion is 10:1 and the average tabular grain 4 is 0.1
It was μm. It appears that the ten-shaped particles having a diameter smaller than 0.6 μm were somewhat reduced in size, as determined by the average aspect ratio and projection l[1] obtained in the Examples. However, there are enough numbers to change the result to the intention of the meeting,
There wasn't. The halide content of "Reisaku" was 85 moles of bromide and 15 moles of chloride. Examples 2 to 5 The operation of Example 1 was repeated. However, by changing the normality of all halide ions in the reaction vessel (i.e., the pA at the time of precipitate formation)
g k was varied), while other parameters remained unchanged.

The results of Examples 1 to 5 are shown in Table 1 below. Examples 1 and 4 represent preferred embodiments of the invention Kurahashi, and Example 2 is a contrast.

Example 6 1.51 gelatin at 80°C with vigorous stirring, 0.168
1.95 liters of M potassium bromide solution,! ! The entire 2.20 M bromide solution was added in 2 minutes by jet, and the 2.0 M silver nitrate solution was added at such a rate that 2.8 mm of the total silver nitrate used was consumed; The recorded pAg't-retained. The addition of bromide and silver nitrate solution was then continued for 6 minutes (11.4 times from start to finish) with an accelerated flow t during which the same pAg t
- 52.6 tons of total silver nitrate retained and used was consumed.

Next, add 30 t of 0.68 M sodium chloride solution and then add 22 t of total silver nitrate using vitreous solution.
It was added in 1.5 minutes at a flow rate where 5% was consumed.

It gave a pAg value that was 3 pAg units lower than the original pAg value. Next, 1.4M potassium bromide solution (0.61M
Sodium chloride) and 2.0 M silver nitrate solution t1 were added simultaneously in 2.2 minutes at the same constant flow rate where 22.1% of the total silver nitrate was consumed while pAg t was held constant. Next, pAgt-0-4 pAg units were lowered. A total of 2.2 moles of silver nitrate were used.

The grains included a silver bromide central grain region and a loamy grain region consisting essentially of silver bromochloride surrounding the central grain region K laterally. Tabular grains with thicknesses of less than 0.3 μm and diameters of at least 0.6 μm exhibit an average aspect ratio of 10:1, accounting for approximately 9 of the total projected area of the halo-chain grains present.
It occupied 0%'i.

The particles had an average thickness of approximately 16 Am and an average diameter of 1.6 μm. The total halide content of the emulsion was 93 moles of turamide and 7 moles of chloride.

Example 7 A 2.0 M potassium bromide solution and a 2.0 M silver nitrate solution were added to 6.0 liters of a vigorously stirred 0.168 M potassium bromide solution containing 1.5 qk gelatin at 55° C. using a double jet for 12 minutes. during which pAg'
Holding the value recorded before the lr addition, 9.1 g of the total silver nitrate used was consumed. When the addition of these solutions is stopped, the contents of the reaction volume are dialyzed to remove pAgt in the reaction vessel.
decreased by 1.23 pAg units. The volume in the reaction vessel was raised to 8 liters by adding 2.0 liters of 1.88 M potassium chloride solution (0.01 M potassium bromide), which gave a ratio of (Ct'''']/(Br-3 of 47 :1.1.72M potassium bromide solution (1
．． 24M potassium chloride) t-, at an equal constant rate for 2 hours, 2. It was added simultaneously with the OMfi acid silver solution. 90.991 of the total silver nitrate used was consumed.

While Oku chloride steel is precipitating, the temperature of 79° in the reaction vessel is 0.
．． It was 48M. A total of 4 moles of silver nitrate were used in preparing the emulsion. Upon completion of precipitation, the emulsion was precipitated in the manner of Example 1.

The grains included a central grain region of bromide chains and an angular grain region of silver bromochloride surrounding the sides of the central grain region. 0.
The tabular grains t'i had an average aspect ratio of 7.5:1 with a thickness of less than 3 μm and a diameter of at least 0.6 μm and accounted for about 85+ of the total projected area of silver halide present. The particles have an average thickness of 0.17 μm and 1.3 μm.
It had an average diameter of m. The total halon content of the emulsion was 86 moles of bromide and 14 moles of chloride.

Example 8 (comparative example) Total halogen ion concentration t-0 during the formation of inner silver chloride precipitate
．． The procedure of Example 7 was repeated except that the amount was reduced to 0.048M.

The tabular grains produced had a much smaller diameter of 0.82 μm compared to 1.30 μm in Example 7, and were thicker at 0.21 μm compared to 0.17 μm in Example 7. Oh.

Example 9 High aspect ratio tabular grains kgclB used in this example
Emulsion r was prepared as described in Example 1. The resulting high aspect ratio tabular grains AgCtBr (approximately 1
5:85) The emulsion has a mean grain diameter of 1.5 μm, 0.15
It had an average grain thickness of μm and an average aspect ratio of lO:l. Tabular grains having a thickness less than 0.30 μm and a diameter of at least 0.6 μm accounted for about 80% of the total projected area of the grains. This flat AgCjBr
The emulsion had an average volume/grain of 0.49 μms.

Control^gcLBr emulsion Ai was prepared by the halide conversion process described below.

A solution of 460 Il/l of 1709 silver nitrate in distilled water at 40° C. was added to a solution of 2590 monosensitized gelatin derivative and 85 g potassium chloride in 1 liter of distilled water at 65° C. under stirring for about 15 minutes. Immediately after addition of silver nitrate, 4
A solution of 1221i potassium bromide in distilled water at 65° C. was added to the production vessel in about 28 minutes. After the addition of potassium bromide was complete, the emulsion was held at a temperature of 65°C for about 15 minutes under stirring and then cooled to about 33°C. The pH of the emulsion was then lowered to -3.8, the coagulated emulsion was cooled to about 5°C, allowed to settle, and the supernatant liquid was then removed. Next, the emulsion was redispersed in the original volume of 40°C distilled water, and 6.
Adjusted to 0. Next, the pH was lowered to 4.0, the temperature was lowered to about 5°C, the solidified emulsion was allowed to settle again, and the supernatant liquid was removed.The emulsion was then redispersed at 40°C and gelatin was added. and pAg'ft-5.5 and 8 respectively
．． Adjusted to 4. The haloron concentration of the silver bromochloride emulsion obtained was about 15 moles of chloride and about 85 moles of bromide. The resulting non-tabular AgCtBr emulsion was 0.69μ
It had an average volume of m2/particle.

High aspect ratio tabular AgCtBr Tr was optically sensitized as described below.

emulsion? Chemical treatment with 4.0 m 9 sodium thiosulfate pentahydrate/Ag mol and 4,θ~potassium tetrachloroaurate for 20 minutes at 70°C, followed by 400 μm of anhydro-5,6-dimethoxy-5'-methylthio-3, 3'-di(3-sulfozolobyl)thiocyanine hydroxide,
Spectrally sensitized using triethylene salt/Ag mole KA.

Both the tabular grain kgcLBr emulsion and the control AgCtBr emulsion A were separately deposited on cellulose triacetate film supports at 2.15 #silver/m and 8.6.9 #gelatin 7
It was applied in m2.

In order to measure the intrinsic sensitivity of the halogenated emulsion as a reference point, the coating layer was passed through a continuous density tablet of 0 to 3.
Exposure to mercury vapor at a wavelength of 65 nm for 1 second, and use N-methyl-p-aminophenolsulfate hydrochloride developer (Kodak Developer DK-50).
) for 3 minutes at 20°C. To evaluate the spectral response, the coated layer was exposed to a 600 W, 5500 °K tungsten light source 1 through a θ ~ 4, 0 continuous density tablet and a Wratt@n A4 7 filter system.
It was exposed to light for 2 seconds and processed for 3 minutes at 20 DEG C. in Kodak Teherotsuno 4'-DK-50. Relative sensitivity values were recorded at 0.30 densities above the Foog point. As shown in Table 1 below, tabular grain and non-tabular grain conversion -ride AgC
The jBr emulsion layers had comparable proprioception. but,
With optimal chemical and spectral sensitization, the tabular grain kgclH r emulsion layer exhibited excellent sensitivity in the blue spectral region.

(.) Effects and Advantages of the Invention The radiation-sensitive emulsion of the present invention has a higher development rate than the known converted chloride chlorobrode emulsion.

The present invention primarily focuses on the advantages, in a single emulsion, of (l) a tabular silver halide grain morphology consisting primarily of bromide with a substantial proportion of chloride present; (2) an aspect ratio of at least 7:l; (3) f
This achieves the advantage that the majority of all grains, including romides and chlorides, are tabular. In certain preferred embodiments, the present invention provides high aspect ratio silver bromochloride emulsions in which the halides are primarily bromides and the chlorides are present in significant concentrations. This invention allows for the first time tabular silver bromochloride edge growth on silver halide core grains. The present invention primarily provides a tabular grain-containing emulsion in which the central grain region can have a different halogenated steel composition from the surrounding stacked halonized grain regions containing chloride and bromide. It is something.

The present invention provides an advantageous method for making these emulsions, which does not require ammonia, grain growth modifiers, special peptizers or seed particles, and thus allows for the preparation of tabular grain emulsions containing chlorides and zolomides. gives a great deal of confession to.

The present invention provides the advantages of tabular grain structure for photographic applications, such as black-and-white and color print materials, where silver halide grains consisting primarily of zolomides, including chloride and promide, are used. The present invention is a silver halide emulsion containing a chloride and a bromide as a king component, comprising:
It enables the production of emulsions exhibiting high contrast such as required for graphic arts applications. The bromochloride pot emulsions of this invention can also provide other photographic advantages such as higher night speed and faster photographic processing than converted no-ride emulsions of no-ride-like composition.

The sensitivity-grainness relationship and sharpness of photographic images can be improved by using the emulsion according to the present invention, especially an emulsion having a large average grain size. When spectrally sensitized outside the spectral region of native sensitivity, the emulsions of the invention exhibit greater sensitivity separation in the spectral region of native sensitivity compared to the spectral region in which they are fractionally sensitized. .

When the emulsion according to the present invention is used in a radiographic element coated on both sides of a radiolucent support, cross-over/4
Alternatively, with the emulsions of the present invention, significant crossover levels can be achieved with lower silver coverage and/or while achieving improved speed-to-granularity relationships.

The image transfer film unit containing the emulsion according to the present invention is
After the start of the process, a town view image can be generated in a short period of time. High contrast of transferred images}
t-Can be achieved with short-time development. The emulsions of the present invention generally allow for reduced silver coverage, more efficient use of dye image forming agents in the image transfer film unit and advantageous layer ordering, elimination or reduction of yellow filter material, and lower Gives the temperature dependence of the image.

Margin below

[Brief explanation of the drawing]

1, 3, 4, and 5 are electron micrographs of the emulsion according to the present invention, FIG. 2 is an electron micrograph of an emulsion as a comparative example9, and FIG. 6 is a rounded image explaining the sharpness characteristics. FIG. DESCRIPTION OF SYMBOLS 1... Emulsion, 3... Support, 5... Parallel light source, 9
...Detection surface. -276-

Claims (2)

[Claims] 1. The tabular grains are composed of a dispersion medium and an octaryl silver grain, the tabular grains have opposing parallel (111) major faces, the tabular grains contain chloride and bromide at least in the annular grain region, and the tabular grains have a thickness of less than 0.3 micrometers, a diameter of at least 0.6 micrometers, and an average aspect ratio of at least 7:1 and at least 35% of the total projected area of the silver halide grains;
1, and the tabular grains have a chloride to 1P ratio of up to 2:3 in at least 4 regions of the annular grains.
A radiation-sensitive emulsion characterized in that it has a mean ratio of 0. 2. The tabular grains are composed of a dispersion medium and halogenated fil grains, and the tabular grains have opposing parallel (I'll} major faces and contain chloride and proκ-d in at least the annular grain region, and the tabular grains have having a thickness of 0.3 micrometers, a diameter of at least 0.6 micrometers, and an average aspect ratio of at least 7:1, and having at least the total projected area of the pre-formed silver grains. A radiation-sensitive emulsion in which the tabular grains have an average chloride to bromide molar ratio of up to 2:3 in at least the annular grain region is placed in a reaction vessel containing at least a portion of a dispersion medium. , a method for producing by simultaneously introducing chloride and bromide salt, the molar ratio of chloride ions to bromide ions in the reaction vessel being 1.6:
1 to gss:t, and the total concentration of halon ions in the reaction vessel is maintained in the range of 0.10 to 0.90 normal. to one