JP3268109B2 - Low silver color photographic element and dye image forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION This invention relates to color photographic elements containing silver halide emulsions and a method for forming a dye image.

[0002]

BACKGROUND OF THE INVENTION Radiation-sensitive silver halide emulsions containing one or a combination of chloride, bromide and iodide ions have long been recognized as being useful in photography.
Each halide ion selection is known to provide certain photographic advantages. Due to wide limits, the most commonly used photographic emulsions are silver bromide and silver bromoiodide emulsions. Despite being known and used for many years for selected photographic applications, the faster developability and ecological benefits of high chloride emulsions extend beyond a wide range of photographic applications to those emulsions. Promoted use. The term "high chloride emulsion" as used herein refers to a silver halide emulsion containing at least 50 mol% chloride, based on total silver. The most ecologically attractive high chloride emulsions are those that contain very low levels of iodide ions.

[0003] In the 1980's, improved sensitivity-granularity relationships, increased coverage on an exquisite basis and as a function of binder curing, faster developability, increased temperature stability, and inherently provided image forming sensitivity. A wide range of photographic advantages, such as increased sensitivity and spectral sensitization separation, and improved image sharpness in both single emulsion layer and dual emulsion layer formats, have been identified in selected tabular grain populations in photographic emulsions. Significant progress has been made in silver halide photography based on the finding that it can be achieved by increasing the ratio of

Various definitions have been applied to define tabular grain emulsions, but tabular grain equivalent circular diameters (ECD,
Diameter of a circle having an area equal to the projected area of the tabular grains)
The difference between the tabular grain thickness (t, the dimension of the tabular grains perpendicular to their opposing parallel major faces), and the functionally significant distinguishing characteristics of the tabular grains, is generally observed. There is a match. Tabular grain aspect ratio (ECD / t)
Has been accepted in the art as defining the amount of this disparity. To distinguish tabular grains from those containing only secondary tabular grains, a useful percentage of total grain projected area (eg, greater than 30%, and typically greater than 50%) is at least 2%. aspect ratio,
And, typically requiring that it be occupied by tabular grains having an average aspect ratio of at least 5, is also routinely recognized in the art.

In many and all cases, the particle thickness (t),
Tabular grain emulsions meeting the goals of aspect ratio (ECD / t) and projected area have been produced by introducing two or more parallel twin planes into octahedral grains during precipitation. Regular octahedral particles are separated by {111} crystal faces. An excellent feature of tabular grains made by twinning is the opposing parallel {111} major crystal faces. The main crystal plane has triple symmetry and typically represents a triangle or hexagon.

The formation of tabular grain emulsions having parallel twin planes is very easily achieved in the preparation of silver bromide emulsions. This technique has found the potential to include photographically useful levels of iodide. Inclusion of high levels of chloride against bromide (alone or in combination with iodide) has been difficult. Silver chloride differs from silver bromide in that it exhibits a very strong tendency to form grains having {100} crystal planes. Unfortunately, twinning of grains bounded by {100} crystal faces does not produce tabular shaped grains. In order to successfully produce high chloride tabular grain emulsions by twinning, conditions must be found that assist in the formation of both twin and {111} crystal planes. In addition, care must be taken in subsequent handling after the emulsion is formed to prevent the grains from reverting to a more stable shape exhibiting the preferred {100} crystal planes of the grains.

The following represent background art relating to emulsions: Wey US Pat. No. 4,399,215; Wey et al. US Pat. No. 4,414,306; Maskasky US Pat. , 400,463
No. (hereinafter referred to as Maskasky I), Ma
U.S. Pat. No. 4,713,323 to Skasky (hereinafter Maskasky II); U.S. Pat. No. 4,942,120 to King et al .; Tufan;
O. et al., U.S. Pat. No. 4,804,621, Tak.
ada et al., U.S. Pat. No. 4,783,398;
U.S. Pat. No. 4,952,491 to Ishikawa et al .; U.S. Pat.
No. 508, Bogg U.S. Pat. No. 4,063,9.
No. 51, Mignot U.S. Pat.
No. 156.

[0008] At times, there has been interest in redox amplification processing to produce dye images in color photographic elements containing silver halide emulsions. A major advantage of the redox amplification process is that less silver can be used in the construction of color photographic elements. For such processing, particularly configured redox amplification processing and color photographic elements are described in Research Disclosure, Vol. 308, 1989.
December, item 308119, section XIX, subsections G and H. ResearchDisclosur
e is Kenneth Mason Publication Ltd., Dudley Annex,
12a North Street, Emsworth, Hampshire PO10 7DQ, E
Published by ngland.

[0009]

A problem has arisen in an attempt to combine the known advantages of high aspect ratio tabular grain emulsions, high chloride emulsions and redox amplification processing. High chloride silver halide grains prefer a grain shape having {100} crystal faces (eg, cubic, less commonly cubo-octahedral). Prior to the present invention, if the redox amplification process was performed using a high chloride emulsion, the particles were typically high chloride cubic grains.

In one aspect, the invention relates to a method wherein the total amount of silver in the dye image-forming layer unit is less than 200 mg / m ² and the emulsion comprises at least 50 mol% chloride, based on total silver forming the grain population. And wherein more than 30% of the projected area of the grain population has an aspect ratio of at least 2, 0.3, respectively.
comprising at least one silver halide emulsion and a dye image-providing compound characterized by being occupied by tabular grains having an average thickness of less than .mu.m and parallel major faces lying in {100} crystal faces. It is directed to a color photographic element containing a dye image forming layer unit.

In another aspect, the present invention is directed to a method of developing a silver halide emulsion to form imagewise silver, wherein the oxidizing agent is inert to redox interactions in the absence of developed silver. And at least one silver halide emulsion by using the developed silver to catalyze the reaction of the reducing agent and reacting the oxidized reducing agent with the image-providing compound to form a dye image. A method for producing a dye image of an imagewise exposed color photographic element comprising a dye image forming layer unit comprising a dye image providing compound, wherein the total silver content of the dye image forming layer unit is 200 mg / m ^2.
Less and the emulsion comprises a silver halide grain population comprising at least 50 mol% chloride, based on total silver forming the grain population, and more than 30% of the grain population projected area, respectively, Aspect ratio of at least 2, average thickness less than 0.3 μm, and {100}
The present invention is directed to a dye image forming method characterized by being occupied by tabular grains having parallel major faces in the crystal plane.

[0012]

The present invention provides a combination of advantages not previously realized. The use of tabular grain emulsions achieves known advantages including improved light sensitivity and increased image sharpness of these emulsions. By using high aspect ratio tabular grains, which are high chloride grains, advantages are realized in faster processing and improved environmental compatibility of consumed processing solutions. By using high chloride tabular grains having a major surface in the {100} crystal plane, tabular grains that are inherently more stable than {111} tabular grains (hereinafter referred to as {100} tabular grains) Call)
Is provided. For example, {100} tabular grains are
It does not show a tendency to revert to non-tabular shape, thus eliminating the need to rely on adsorbed particle shape stabilizers used in combination with high chloride {111} tabular grains. When a color photographic element is constructed in accordance with the present invention, the extremely low levels of total silver inherent in the redox amplification process, combined with the remaining advantages, are superior to those previously available in the art. Color photographic elements and redox amplification processes and systems can be achieved. The color photographic elements of the present invention have the potential to produce lower granularity dye images than previously realized in dye image generation by redox amplified imaging using high chloride emulsions. Thus the photographic element also has the potential to produce dye images of normal quality using lower levels of total silver than using the high chloride emulsions heretofore used. Consequently, despite the known higher covering power of tabular grains, the color photographic elements can be used to produce dye images that are maintained without bleaching. This means that the silver coverage,
It offers advantages in processing simplicity and in the environmental compatibility of the processing solution consumed.

In a simple form, a color photographic element satisfying the requirements of the present invention can be constructed as follows: ───────────── Protective overcoat layer ────────────────────────────────── Magenta dye-forming layer unit 中間 Intermediate layer ─────────単 位 Cyan dye forming layer unit ──────────────────── ────────────── Middle layer ────────────────────────────────── Yellow dye forming layer unit ─────────────────────────────── ─── Support ────────────────────────────────── Configuration I The support (S) is transparent or It can be a reflective support and can take any of the conventional forms described in Research Disclosure, Item 308119, Section XVII above. When the color photographic element is used as a camera film, the support is preferably a transparent film support, preferably provided with a processing solution removable or decolorizable antihalation backing layer (not shown) Is done. If a color photographic element is used to produce a visible positive image, the support is preferably a reflective support of the type found in conventional photographic prints.

A protective overcoat (OC) is preferred, but not an essential feature, and provides for the physical protection of the underlying layer unit from physical damage during handling and processing. The protective overcoat is preferably a transparent layer that constitutes a photographic vehicle of the type described in Research Disclosure, Item 308119, Section IX above, and typically includes one or more of the following: coating as described in Section XI. Auxiliaries, plasticizers and / or lubricants as described in Section XII, antistatic agents as described in Section XIII, and matting agents as described in Section XVI.

The magenta (M) dye image forming layer unit is coated furthest from the support and first receives light of imagewise exposure. The magenta dye image-forming layer unit contains at least one silver halide emulsion. This emulsion is most typically a green sensitized emulsion, preferably containing high chloride grains, to minimize blue light contamination of the green light exposure record produced by this emulsion layer.

The cyan (C) dye image forming layer unit is arranged to receive light of imagewise exposure after light passes through the magenta dye image forming layer unit. This emulsion is most typically a red sensitized emulsion, preferably containing high chloride grains, to minimize blue light contamination of the red light exposure record produced by this emulsion layer. The yellow (Y) dye image forming layer unit is typically blue sensitized and is coated closest to the support because the human eye has little sensitivity to this image. Thus, the lower image sharpness during exposure experienced by the dye image-forming layer unit provided by this layer arrangement, with less perceived image collapse,
Can be best adapted. The yellow dye image forming layer unit record preferably contains high chloride particles for a completely different reason than the remaining dye image forming layer units. The processing solution must pass through the two overlying dye image-forming layer units to arrive at the yellow dye image-forming layer unit, where high chloride particles (which can be processed faster) Can be)
Choosing to offset this disadvantage. Blue sensitization
It relies on compensating for the inherently lower blue sensitivity of the high chloride particles in the yellow dye image forming layer unit.

During the processing following the imagewise exposure, the layer units M, C
It is possible to introduce a magenta, cyan and yellow dye image providing compound into each of Y and Y. Processing is preferred. Each dye image-providing compound can be formulated in layer units, together with the emulsion or emulsions, or can be coated in adjacent layers.

Configuration I (using M / C / Y / S order)
Are preferred, but in another order, C / M / Y / S, Y / M / C
/ S, Y / C / M / S, M / Y / C / S, and C / Y
/ M / S are all feasible and possible. Intermediate layer (I
L) includes a conventional oxidized developer scavenger,
Prevents oxidized developing agent from migrating in the layer during processing that may reversely produce color stain in the layer-by-layer dye image. In the order of M / C / Y / S and C / M / Y / S, the usual yellow filter material is inevitably in the intermediate layer, but in the remaining order of application, the yellow filter material is blue sensitized. Can be present in any of the intermediate layers beneath the applied dye image forming layer unit.

The order of the above six types of dye image forming layer units is a sample of the known order of the dye image forming layer units. Ko
U.S. Pat. No. 4,439,520 to Fron et al., which is hereby incorporated by reference, is made possible by providing a plurality of dye image layer units that are responsive in the same spectral region. Various dye image forming layer units are described.

In addition, many other configuration variations are possible. Yellow, magenta and cyan dye image forming layer units, in place of sensitizing to blue, green and red light, respectively, one type or combination of dye image forming layer units,
Sensitization can be made for other portions of the spectrum (one or more spectra outside the visible region, eg, near ultraviolet and near infrared).

In order to capture the color of a photographic subject, at least three types of dye image forming image units are required. However, for certain photographic applications, only two or one dye image forming layer unit is sufficient to provide the required dye image. For example, in order to generate a color separation image, a single dye image generation layer unit is sufficient for each element.
For the simplest multicolor image generation, at least two types of dye image generation layer units are required.

The photographic element has at least two types, preferably
Contains three types of dye image forming layer units,
-The photographic element is 400 mg / m^Two Less total silver,
Preferably 220 mg / m^Two Less and optimally
Is 170 mg / m^Two Includes less total silver. Each dye
Image generation layer unit (used alone or in combination
Used) is 200 mg / m^Two Less total silver,
Preferably 133 mg / m^Two Less, most preferred
110 mg / m^2,And optimally 85mg / m^Two 
Includes less total silver. At least color photographic elements
Also contains two, preferably three, dye image-forming layer units
If so, the photographic element is preferably at least 30 mg
/ M^Two And most preferably at least 40 mg / m
^Two Of total silver. The color photographic element has a reduced number of
If a dye image forming layer unit is included, the entire color photographic element
Silver content can be reduced proportionately. For example, single color
At least 1mg / m2 in raw image generation layer unit^Two Silver amount is good
Preferably, at least 10mg / m ^Two Silver amount is most preferable,
And at least 20 mg / m^Two Of silver
Optimally.

The color photographic element of the present invention contains at least one high chloride {100} tabular grain emulsion in at least one dye image forming layer unit. Preferably, a high chloride {100} tabular grain emulsion is present in each dye image-forming layer unit, and optimally each of the emulsions is a high chloride {100} tabular grain emulsion. All of the emulsions present in the color photographic elements of this invention have a high chloride content of $ 10.
If not a 0 ° tabular grain emulsion, the remaining emulsions can take any of the known forms useful for producing redox amplified images. In certain preferred forms, they
It is a high chloride cubic or cubo-octahedral grain emulsion.
In another particular anticipated form, they are tabular grain silver bromide or silver iodobromide emulsions. High chloride ｛10
It is also possible to use 0% tabular grain emulsions in combination with high chloride {111} tabular grain emulsions, but high chloride {100} tabular grains can be used as high chloride {111} tabular grain emulsions. All high chloride tabular grain emulsions used should be high chloride {100} tabular grain emulsions, as they meet the same application requirements as above and provide the added benefit of intrinsic grain shape stability. Is particularly preferred. The incorporation of emulsions incorporated into the dye image-forming layer units is specifically contemplated to achieve known adjustments in image properties. However, it is generally preferred that the high chloride emulsion or emulsions in the dye image forming layer be a single latent image forming emulsion or emulsions. The high chloride {100} tabular grain emulsions incorporated in and in the color photographic elements of the present invention each comprise at least 50 mole percent chloride, based on the total silver forming the grain population. The silver particle population and more than 30% of the particle population projected area each have an aspect ratio of at least 2, a thickness less than 0.3 μm, and {100}
It is occupied by tabular grains having parallel major faces in the crystal plane. The highest achievable percentage of total grain projected area is an aspect ratio of at least 2 and 0.3 μm.
It is generally preferred to be occupied by high chloride {100} tabular grains having a thickness of less than m (hereinafter referred to as the selected high chloride {100} tabular grain population). The selected high chloride {100} tabular grain population is
Of the total high chloride particle population present in the dye image forming layer unit,
Preferably it accounts for at least 50 mol%, most preferably at least 70% and optimally at least 90% mol. Needle-like and rod-like grains having {100} major faces are, of course, excluded from achieving the selected high chloride {100} tabular grain projected area.
Typically, such particles make up a negligible fraction of the total particle population. In the rare case where the presence of rod-like {100} is not negligible, the distinction between rods and rod-like and tabular grains can be easily achieved by visual inspection of micrographs and 10 or more. For the purpose of providing a quantitative segment, rectangular grain, {100} major surface representation with a greater adjacent edge length ratio, it is excluded from the selected high chloride {100} tabular grain population.

The selected high chloride {100} tabular grain population preferably exhibits an average aspect ratio of at least 5, and most preferably at least 8. Given that the useful maximum average ECD of a photographic element is about 10 μm, just at tabular grain thicknesses of less than 0.3 μm,
It is clear that the tabular grain average aspect ratio just exceeds 33.3. High chloride {100} tabular grains
When selected on the basis of a preferred thickness of less than 0.2 μm (based on the thickness of thin tabular grains), the average aspect ratio will be greater than 50. For tabular grains that are optimally thinner than 0.1 μm, the average aspect ratio can range above 100. Depending on the emulsion precipitation procedure used, extremely thin high chloride {100} tabular grains can form a selected tabular grain population. Ultra-thin (0.07μ in thickness) satisfying the above projected area
m thinner) high chloride {100} tabular grain populations can be prepared. In practice, the maximum average ECD
Rarely exceeds 6 μm, more typically 4 μm
Less than. Thus, an average aspect ratio of 5 to 100, and more typically 8 to 50, is considered to be the selected high chloride {10
Typical of a 0 ° tabular grain population.

In one preferred form, high chloride $ 10
The 0 ° tabular grain emulsion contains at least 50 mole percent chloride and less than 2 mole percent iodide, with the remaining halide being bromide. Silver chloride, silver iodochloride, silver bromochloride,
Silver iodobromochloride and silver bromoiodochloride emulsions are particularly contemplated.
In certain preferred embodiments, the high chloride {100} tabular grains are free of iodide internally and most preferably free of iodide at the site of grain nucleation. When grains are nucleated without iodide, pure silver chloride {100} tabular grains can be formed. Emulsions of this type can be made by the precipitation technique taught in Maskasky, US Pat. No. 5,264,337, incorporated herein by reference. A detailed description of the preparation of this type of emulsion is provided in the examples and the discussion below.

Another method is to nucleate high chloride {100} tabular grains in the presence of iodide. In this method, under conditions that favor the appearance of {100} crystal planes, grain nucleation occurs in a high chloride environment where iodide ions are present. When grain nucleation results in the inclusion of iodide in the cubic lattice formed by silver ions, the diameter of iodide ions is larger than chloride ions,
Chloride residual halide ions are destroyed. The incorporated iodide ions introduce irregularities into the crystal as the grains grow further, producing tabular rather than regular (cubic) grains.

At the beginning of the nucleation, the incorporation of iodide ions into the crystal structure involves the formation of one or more cubic faces,
It is believed to produce cubic grain nuclei generated with growth promoting one or more irregularities. The cubic plane containing at least one disorder then receives silver halide in an enhanced proportion compared to a regular cubic plane (ie, one lacking disorder). If only one of the cubic faces has disorder, grain growth on only one face is promoted, and the grain structure resulting from continued growth is a rod. The same result occurs if only two opposing parallel planes of the cubic structure have irregularities. However, if either of the two adjacent cubic planes has an irregularity, continued growth will promote the growth of both planes and produce a tabular grain structure. It is believed that the tabular grains of the emulsion are formed by these grain nuclei having two, three or four faces with growth promoting disorder.

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

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

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

Grain nucleation occurs immediately upon introduction of silver ions into the dispersion medium. For convenience and reproducibility of the operation, silver ion introduction during the nucleation step is preferably
Prolonged to a convenient period, typically less than 5 seconds to less than 1 minute. No additional chloride ions need to be added to the dispersion medium during the nucleation step as long as pCl remains within the above range. However, during the nucleation step, it is preferred to introduce both the silver salt and the halide salt simultaneously. The advantage of adding the halide salt along with the silver salt throughout the nucleation step is to ensure that the grain nuclei formed after the initial silver ion addition have essentially the same chloride content as the initially formed grain nuclei. That is what you can do. The addition of iodide ions during the nucleation step is particularly preferred. Unless replenished, iodide is consumed in the dispersing medium since the rate of iodide deposition is much higher than the rate of deposition of other halides.

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

It is possible, but not preferred, to introduce silver chloride or silver iodochloride Lippmann grains into the dispersion medium during the nucleation step. In this case, particle nucleation has already occurred, and the nucleation step already referred to herein is actually a step for introducing irregularities on the particle surface. The advantage of delaying the step of introducing grain surface irregularities is that it produces thicker tabular grains than otherwise obtainable.

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

The peptizer is a photographic silver halide emulsion,
In particular, it can take any convenient conventional form known to be useful for precipitating tabular grain silver halide emulsions. For an overview of peptizing agents, see Research Discl
osure, Vol. 308, December 1989, section IX. Research Disclosure by Kenneth Maso
n Publication Ltd., Emsworth, Hampshire PO10 7DQ,
Published by England. Maska already quoted
Synthetic polymeric peptizers of the type disclosed by sky I (herein incorporated by reference) can be used, but gelatinous peptizers (eg, gelatin and gelatin derivatives) can be used. It is preferably used. It is a known practice to use deionized gelatinous peptizers, since gelatinous peptizers produced and used in the field of photography typically contain significant concentrations of calcium ions. In the latter case, calcium ions removed are supplemented by adding divalent or trivalent metal ions such as alkaline earth or alkaline earth metals (preferably magnesium, calcium, barium or aluminum ions). Is preferred. Particularly preferred peptizers are low methionine gelatinous peptizers (ie, those containing less than 30 micromoles of methionine per gram of peptizer), and optimally less than 12 micromoles per gram of peptizer. belongs to. These peptizers and their preparation are disclosed in the patent specifications of Maskasky II and King et al., Cited above (herein incorporated by reference). But MaskaskyI and Maskasky II
It should be noted that grain growth modifiers of the type taught as inclusions in emulsions such as adenine are not suitable as inclusions in dispersion media. This is because these grain growth modifiers promote twinning and formation of tabular grains having {111} major faces. Generally, at least about 10% and typically 20% of the dispersion medium that produces the finished emulsion.
８０80% is present in the reaction vessel at the beginning of the nucleation step. It is common practice to maintain a relatively low level of peptizer in the reaction vessel at the beginning of precipitation, typically 10-20% of the finished emulsion. At the beginning of the nucleation step, the concentration of the peptizer in the dispersing medium is 0.1% of the total weight of the dispersing medium in order to increase the proportion of thin tabular grains having {100} faces formed during nucleation. Preferably it is in the range of 5 to 6% by weight. It is common practice to add gelatin, gelatin derivatives and other vehicles and vehicle extenders to prepare emulsions for application after precipitation. After precipitation is complete, natural levels of methionine can be present in the added gelatin and gelatin derivatives.

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

The nucleation step is followed by a grain growth step in which grain nuclei are grown until tabular grains having the desired average ECD {100} major surface are obtained. Whereas the purpose of the nucleation step is to form a population of grains with the desired incorporated crystal structure irregularities, the purpose of the growth step is to avoid or minimize the formation of additional grains. To deposit (grow) additional silver halide on existing grain populations. If additional grains are formed during the growing step, the polydispersity of the emulsion increases and if the conditions in the reaction vessel are not maintained as described above during the nucleation step, the additional grains formed during the growing step Will not have the desired tabular grain characteristics described herein for use in the present invention.

In its simplest form, the emulsion preparation process can be performed as a single jet precipitation without interruption of silver ion introduction from start to completion. As generally recognized by those skilled in the art, a spontaneous transition from grain formation to grain growth also occurs at a uniform rate of silver ion introduction. This is because grain nuclei increase in size from the dispersing medium by increasing the size of the nuclei until the point where the nuclei accept silver and halide ions at a sufficiently high rate that new grains cannot form. This is because the rate at which the halide ions can be accepted is increased. While easy to operate, single jet precipitation limits halide content and profile and generally results in a more polydisperse population of particles.

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

In preparing the desired emulsion, it is preferable to interrupt the introduction of silver and halide salts at the end of the nucleation step and before beginning the growth step which brings the desired final size and shape to the emulsion. . The emulsion is maintained within the temperature range described herein for nucleation for a period sufficient to reduce the degree of grain dispersion. The retention time is 1
It can range from minutes to hours, with typical retention times of 5
Minutes to an hour. During the retention period, the relatively smaller particles Ostwald ripen over the remaining relatively larger particle nuclei, resulting in an overall reduction in particle dispersity.

If necessary, during the holding period, the ripening rate can be increased by the presence of a ripening agent in the emulsion. A common and simple way to promote ripening is to increase the halide ion concentration in the dispersion medium. This produces a complex of silver ions having multiple halide ions that promote ripening. When using this method, it is preferable to increase chloride ions in the dispersion medium. That is, it is preferable to lower the pCl of the dispersion medium within a range where increased silver halide dissolution is observed. Alternatively, ripening can be promoted and the percentage of projected area of the grain population occupied by {100} tabular grains can be increased by using conventional ripening agents. Preferred ripening agents are sulfur-containing ripening agents such as thioethers. A typical thioether ripening agent is McBride
U.S. Pat. No. 3,271,157, Jone
U.S. Pat. No. 3,574,628 and R.
Osencrantz et al., US Pat. No. 3,737,3.
No. 13 (disclosed herein by reference). Recently crown thioethers have been proposed for use as ripening agents. Ripening agents with primary or secondary amino components such as imidazole, glycine or substituted derivatives are also effective. Sodium sulfite has also been demonstrated to be effective in increasing the percentage of total grain projected area occupied by {100} tabular grains.

Once the desired population of grain nuclei has been formed, grain growth begins according to any convenient conventional precipitation technique for precipitating silver halide grains separated by {100} grain faces. It is necessary that iodide and chloride ions be incorporated into the grains during nucleation, so that iodide and chloride ions are present at internal nucleation sites in the finished grains, but have a cubic lattice structure. A halide or a combination of halides known to form can be used during the growth step. Once introduced, the irregular grain nuclei that cause tabular grain growth persist during the next grain growth, irrespective of the halide being precipitated, so that both iodide and chloride ions are grown during the growth process. It need not be incorporated into the grains, but the given halide or combination of halides will form a cubic lattice. This means that iodide levels above 13 mol% (preferably 6 mol%) of the precipitated silver iodochloride, above 40 mol% (preferably 30 mol%) of the precipitated silver iodobromide. It excludes only iodide levels and proportionately intermediate levels of precipitated silver iodohalide, including bromide and chloride. If silver bromide or silver iodobromide is deposited during the growth step,
It is preferred to maintain the pBr in the dispersion medium in the range 4.2, preferably in the range 1.6-3.4. When silver chloride, silver iodochloride, silver bromochloride or silver iodobromochloride is deposited during the growth step, it is preferable to maintain pCl in the dispersion medium within the range already shown in the nucleation step described above.

It was a completely unexpected finding that by introducing certain halides during grain growth, a reduction in tabular grain thickness of up to 20% could be achieved. Surprisingly, the addition of bromide in the range of 0.05 to 15 mol%, preferably 1 to 10 mol% based on silver during grain growth is more than achieved in precipitation under the same conditions without bromide ions. Also relatively thinner $ 1
It was observed to form 00 tabular grains. Similarly, the addition of iodide in the range of 0.001 to less than 1 mole% based on silver during grain growth is relatively thinner than that achieved by precipitation under the same conditions without iodide ions. It was observed to produce {100} tabular grains.

During the growth step, both the silver and the halide salt are preferably introduced into the dispersion medium. In other words, a double-jet precipitation is conceivable, with the addition of an iodide salt which, if necessary, is introduced together with the remaining halide salt or via a separate jet. The rate at which silver and halide salts are introduced is controlled to avoid renucleation (ie, formation of a new grain population). The addition rate control to avoid renucleation is Wilgus
German Offenlegungsschrift 2,107,118, Ir
IE, U.S. Pat. No. 3,650,757, Kur
z, US Pat. No. 3,672,900, Sait.
o U.S. Pat. No. 4,242,445 and We
y's "Growth Mechanism of AgBr Crystals in Gelatin"
Solution ", Photographic Science and Engineering, V
ol. 21, No. 1, February 1977, page 14, etc., as is generally known in the art.

In the simplest form of particle precipitation, the nucleation and growth stages of the particle precipitation occur in the same reaction vessel. However, it is recognized that the particle precipitation can be interrupted, especially after the nucleation stage has ended. Further, two separate reaction vessels can be replaced by a single reaction vessel described herein. The nucleation step of particle precipitation can be performed in an upstream reaction vessel (referred to herein as a nucleation reaction vessel), and the dispersed particle nuclei are converted to a downstream reaction vessel (herein referred to as a nucleation reaction step) where the growth step of particle precipitation occurs. (Referred to as the growth reaction vessel in the text). U.S. Pat. No. 3,790,386 to Posse et al., Forster.
Et al., U.S. Patent No. 3,897,935, Finn.
U.S. Pat. No. 4,147,551 to Icum et al.
And U.S. Pat.
As described in U.S. Pat. No. 24, incorporated herein by reference, some arrangements of this type use a closed nucleation vessel to receive the reactant upstream of the growth reaction vessel. And it can be stirred. In these arrangements, the contents of the growth reaction vessel are recycled to the nucleation reaction vessel. It is contemplated herein that various important parameters controlling particle formation and growth, such as pH, pAg, ripening, temperature, and residence time, are independently controlled in separate nucleation and growth reaction vessels. Can be In order to make the particle nucleation completely independent of the particle growth occurring downstream of the growth reaction vessel of the nucleation reaction vessel, it is better not to recirculate the contents of the growth reaction vessel at all to the nucleation reaction vessel. A preferred arrangement for separating particle nucleation from the contents of a growth reaction vessel is described in US Pat.
No. 334,012 (which also discloses useful aspects of ultrafiltration during particle growth), Urabe U.S. Pat. No. 4,879,208, and published European Patent Application 326852. No. 326853 No. 3
55535 and 370116, Ich
Published European Patent Application No. 368,275 to Izo; Published European Patent Application No. 3749 to Urabe et al.
No. 54 and Onishi et al., JP-A-2-172817.
The issue is disclosed by

The method of grain nucleation has been described herein above using the term iodide to form the crystal irregularities required for tabular grain formation, but in the following examples As described, another nucleation method has been devised which eliminates the need for iodide ions present during nucleation to produce tabular grains. Furthermore, these alternative methods are compatible with the use of iodide during nucleation. Therefore, these methods are quite reliable during nucleation for tabular grain formation,
Alternatively, it can be relied on in combination with iodide ions during nucleation to form tabular grains.

Rapid grain nucleation, so-called dump nucleation (a significant level of the dispersing medium is supersaturated with halides and silver ions present during nucleation) is the cause of tabular irregularities. Promote the introduction of Since nucleation is achieved essentially instantaneously, the immediate transition from initial supersaturation to the preferred pCl range described herein is entirely consistent with this method.

It has also been observed that maintaining the level of peptizer in the dispersing medium during grain nucleation at a level of less than 1% by weight enhances tabular grain formation. It is believed that the fusion of grain nucleus pairs is at least partly responsible for introducing crystal disorder leading to tabular grain formation. Limited coalescence can be facilitated by not using a peptizer in the dispersion medium or by limiting the concentration of the peptizer initially. Mignot
U.S. Patent No. 4,334,012 describes particle nucleation without peptizers, with removal of soluble salt reaction products to avoid nuclear fusion. Because limited fusion of particle nuclei may be desirable, Mignot's aggressive intervention to eliminate particle nuclei can either be eliminated or moderate. It is also conceivable to increase the limited particle coalescence by using one or more peptizers with low adsorption on the particle surface.
For example, it is observed that low methionine gelatins of the type disclosed by Maskasky II are not as well absorbed as those containing higher levels of methionine. Further, moderate particle adsorption can be achieved with so-called "synthetic peptizers" (ie, peptizers made from synthetic polymers).
The maximum amount of peptizer that is compatible with limited particle nucleus fusion is, of course, related to the strength of the adsorption on the particle surface. Once grain nucleation is complete, immediately after the introduction of the silver salt, the peptizer level can be increased to a convenient normal level for the remainder of the precipitation step.

At concentrations of up to 10 ^-2 moles per silver mole, typically less than 10 ^-4 moles per silver mole, the dopant can be present in the grains.
Copper, thallium, lead, mercury, bismuth, zinc, cadmium, rhenium, and Group VIII metals (eg, iron,
Metal compounds such as ruthenium, rhodium, palladium, osmium, iridium and platinum) can be present during the precipitation of the particles, preferably during the growth phase of the precipitation. Improvements in photographic properties are related to the level and location of the dopant within the grain. If the metal forms part of a coordination complex, such as a hexa or tetra coordination complex, the ligand can also be included within the particle, and further, the ligand is Can affect photographic properties. Ligands such as halo, aquo, cyano, cyanate, thiocyanate, nitrosyl, thionitrosyl, oxo and carbonyl ligands are conceivable and can be relied upon to improve photographic properties.

The dopants and their addition are
Old et al., U.S. Pat. No. 1,195,432, H.
ochsetter U.S. Pat. No. 1,951,933
No. 2,628,1 to Overman.
No. 67, U.S. Pat. No. 2,952 to Mueller et al.
No. 0,972, McBride, U.S. Pat.
No. 287,136; Sidebotham US Pat. No. 3,488,709; Rosecran.
ts et al., US Pat. No. 3,737,313, Sp.
U.S. Pat. No. 3,687,676 to No. ence et al.
U.S. Pat. No. 3,761,267 to Gilman et al., U.S. Pat. No. 3,790,390 to Shiba et al., U.S. Pat. No. 3,890,154 to Ohkubo et al.
US Patent No. 3,901,7, Iwaosa et al.
No. 11, Habu et al., US Pat. No. 4,173,4.
No. 83, Atwell, U.S. Pat. No. 4,269,
No. 927, Janusonis et al., U.S. Pat. No. 4,835,093, McDuggle et al., U.S. Pat. Nos. 4,933,272, 4,981,781
No. 5,037,732, and Keeve
No. 4,945,035 to rt et al. and US Pat. No. 5,024,931 to Evans et al. (herein incorporated by reference). For background on known alternatives in the technical field of interest, see B.A. H. Carroll's "Iridium
Sensitization: A Literature Review ", Photographic
Science and Engineering, Vol. 24, No. 6, 1980 11
Dec., pp. 265-257, suggested in published European Patent Application 264,288 to Grzekowiak et al.

Although not required, an additional measure that can be used to maximize the population of high chloride {100} tabular grains is the appearance of non- {100} grain crystal faces of the emulsion during emulsion preparation. Is to incorporate a drug that can suppress the If an inhibitor is used, it can be activated during grain formation, growth or throughout precipitation. Under possible precipitation conditions, useful inhibitors are resonance stabilized p
Organic compounds containing nitrogen atoms with electron pairs. Resonance stabilization prevents protonation of the nitrogen atom under the relative acid conditions of the precipitation.

Aromatic resonance can rely on the stability of the π electron pair of the nitrogen atom. The nitrogen atom can be incorporated into an aromatic ring, such as an azole or azine ring, or can be a ring substituent on an aromatic ring. In one preferred form, the inhibitor can satisfy the following formula (I):

[0053]

Embedded image

Wherein Z represents the atoms necessary to complete a 5- or 6-membered aromatic ring structure and is preferably formed by carbon and nitrogen ring atoms.
An aromatic ring has one, two or three nitrogen atoms. Particularly contemplated ring structures include 2H-pyrrole, pyrrole, imidazole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, 1,3,5-triazole, pyridine, pyrazine, pyrimidine, and pyridazine. Include.

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

[0056]

Embedded image

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

The following are compounds of formula I and / or
Representative compounds considered to satisfy I:

[0059]

Embedded image

[0060]

Embedded image

[0061]

Embedded image

[0062]

Embedded image

[0063]

Embedded image

[0064]

Embedded image

[0065]

Embedded image

The selection of preferred inhibitors and their effective concentrations can be carried out by the following selection procedure: The compounds to be used as inhibitors are converted from essentially cubic grains having an average grain edge length of 0.3 μm. To the resulting silver chloride emulsion. This emulsion was prepared in sodium acetate at 0.2
Molar, pCl is 2.1, at a pH at least one unit greater than the pKa of the compound considered. The emulsion is kept at 75 ° C. for 24 hours with inhibitors. 2
When the cubic particles have a sharper edge of {100} crystal face than the control, which differs only in the absence of possible compounds, by microscopic examination after 4 hours, the incorporated compound functions as an inhibitor. I have. The meaning that the intersecting edges of the {100} crystal planes are angular is the fact that the particle edge is the most active site on the particle due to ions re-entering the dispersion medium. By maintaining sharp edges, inhibitors are present at, for example, rounded edges and corners, and serve to suppress the appearance of non- {100} grain crystal faces. In some cases, instead of dissolved silver chloride which exclusively adheres to the edges of cubic grains,
A new population of particles is formed, separated by the 00 crystal plane. Optimum inhibitor activity occurs when the new grain population is a tabular grain population where the tabular grains are separated by {100} major crystal faces.

It is particularly conceivable that silver salt is epitaxially attached to tabular grains acting as a host. Conventional, epitaxial deposition on high chloride silver halide grains is described in Maskasky US Pat. No. 4,435,50.
No. 11 (especially Example 24B); U.S. Pat. Nos. 4,786,588 and 4,791,05 to Ogawa et al.
No. 3, U.S. Pat. No. 4,820, to Hasebe et al.
No. 624 and 4,865,962, Sugi
Moto and Miyake's "Mechanism of Halide Co"
nversion Process of Colloidal AgCl Microcrystals b
y Br ^- Ions ", Parts I and II, Journal of Colloid a
nd Interface Science, Vol. 140, No. 2, 1990 December
Moon, pp. 335-361, Houle et al., US Pat. No. 5,033.
No. 5,992, Japanese Patent Application Laid-Open No. 03-252649 (Japanese Patent Application No. 02-051165 filed on March 2, 1990 has priority) and Japanese Patent Application Laid-Open No. 03-288143 (April 4, 1990) Priority is given to Japanese Patent Application No. 02-089380 filed in Japanese Patent Application No.
Nos. 73430, 341728 and 531799. The disclosure of the above U.S. patent specification is incorporated herein by reference.

The emulsion used in the present invention was prepared using an activated gelatin (TH James, The Theory of the Photograph).
ic Process 4th Edition, Macmillan, 1977, pp. 76-76) or sulfur, selenium, tellurium, gold,
Platinum, palladium, iridium, osmium, rhenium or phosphorus sensitizers, or combinations of these sensitizers (particularly combinations of gold or selenium and sulfur), for example, pAg levels of 5-10, pH levels of 5-8 and At a temperature of 30 to 80 ° C, Research Disclosure, Vol.
120, April 1974, Item 12008, Research Disclos
ure, Vol. 134, June 1975, item 13452, She
U.S. Pat. No. 1,623,499 to Ppard et al .; U.S. Pat. No. 1,673,52 to Matthies et al.
No. 2, U.S. Pat. No. 2,399, to Waller et al.
No. 083, U.S. Pat. No. 2,642,361 to Damschroder et al., U.S. Pat. No. 3,297,447 to McVeigh, U.S. Pat. No. 3,297,446 to Dunn, McBrideno.
British Patent 1,315,755; Berry et al., US Pat. No. 3,772,031, Gilma
U.S. Pat. No. 3,761,267 to Ohi et al.
Et al., U.S. Pat. No. 3,857,711, Klin.
Ger et al., U.S. Pat. No. 3,565,633;
U.S. Pat. No. 3,901,714 to ftedahl, U.S. Pat. No. 1,396,696 to Simons and U.S. Pat. No. 5,049,48 to Deaton.
No. 5, chemical sensitization can be performed, and the chemical sensitization can be performed, if necessary, by Damschrod.
r, the thiocyanate derivatives described in US Pat. No. 2,642,361, Lowe et al., US Pat.
No. 521,926, U.S. Pat. No. 3,021,215 to Williams et al. And Bigelow.
Thioether compounds described in U.S. Pat. No. 4,054,457 to Dostes, U.S. Pat. No. 3,411,914 to Dostes, U.S. Pat. No. 3,554,757 to Kuwabara et al. Et al., US Pat. No. 3,565,631 and Offt.
Azaindene, azapyridazine, and azapyrimidine, published European patent application 294149, such as Miyoshi, and published European patent application 297804, such as Tanaka, described in U.S. Pat. No. 3,901,714 to edahl. The reaction is carried out in the presence of the elemental sulfur described in the above specification and the thiosulfonate described in published European Patent Application 293917 to Nishikawa et al. Additionally or alternatively, the emulsion may be prepared as described, for example, in Janusonis U.S. Pat.
Low pAg (eg, below 5), high pH (eg, above 8) treatment with hydrogen as described in US Pat. No. 1,446 and Babcock et al., US Pat. No. 3,984,249. Or by Allen
Et al., U.S. Pat. No. 2,983,609;
Dahl et al., Research Disclosure, Vol. 136, 1975
August, Item 13654, US Patent No. 2,5 to Lowe et al.
18,698 and 2,739,060,
U.S. Pat. Nos. 2,743,182 and 2,743,183 to Roberts et al., Chambers;
Et al., U.S. Pat. No. 3,026,203 and Bi.
Reduction sensitization can be accomplished using reducing agents such as stannous chloride, thiourea dioxide, polyamines and amine borane as described in US Pat. No. 3,361,564 to gelow et al.

Chemical sensitization is described in US Pat. No. 3,628,960 to Philippaerts et al., Kofro.
U.S. Patent No. 4,439,520 to Dic.
US Pat. No. 4,520,098 to Kerson, US Pat. No. 4,435,501 to Maskasky.
No. 4,693,96 to Ihama et al.
5 and Ogawa U.S. Pat. No. 4,791,
This can be done in the presence of a spectral sensitizing dye as described in EP-A-053. Chemical sensitization is performed on silver halide grains as described in British Patent Application Publication No. 2,038,792 to Haugh et al. And Published European Patent Application No. 302528 to Mifrne et al. Or the crystal plane. Mor
Ugan, U.S. Pat. No. 3,917,485, B.
As described in U.S. Pat. No. 3,966,476 to Ecker and Research Disclosure, Vol. 181, May 1979, Item 18155, the photosensitive centers resulting from chemical sensitization may be added to twin jet-added or silver And partially or totally plugged by precipitation of an additional layer of silver halide using means such as pAg circulation with another addition of a halide salt. In addition, the above M
As described by organ, a chemical sensitizer is
It can be added before or simultaneously with the additional silver halide formation. Chemical sensitization can be performed during or after halide conversion, as described in published European Patent Application 273404 to Hasebe et al. In many cases, epitaxial deposition on selected tabular grain sites (eg, edges or corners)
It can be used either for direct chemical sensitization, or for itself to perform the action normally performed by chemical sensitization.

Emulsions used in the present invention may be prepared from cyanines, merocyanines, complexes of cyanines and merocyanines (eg, tri-, tetra- and polynuclear cyanines and merocyanines), styryls, merostyryls,
It can be spectrally sensitized with dyes from various classes, including polymethine dye classes, including streptocyanins, hemicyanines, arylidenes, allopolar cyanines, and enamine cyanines.

The cyanine spectral sensitizing dye is composed of two basic heterocyclic nuclei connected by a methine bond, for example, quinolinium, pyridinium, isoquinolinium,
3H-indolium, benzoindolium, oxazolium, thiazolium, selenazolium, imidazolium, benzoxazolium, benzothiazolium, benzoselenazolium, benzotellrazolium, benzimidazolium, naphthoxazolium, naphthothiazol Includes those derived from ium, naphthoselenazolium, naphthotellazolium, thiazolinium, dihydronaphthothiazolium, pyrylium, and imidazopyrazinium quaternary salts.

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

It is possible to use one or more spectral sensitizing dyes. Dyes with maximum sensitization at wavelengths over the visible and infrared spectra and dyes with a wide variety of spectral sensitivity curve shapes are known. The choice and relative proportion of the dye will depend on the region of the spectrum with the desired sensitivity and on the desired spectral sensitization curve shape. Examples of materials sensitive to the infrared spectrum include U.S. Pat.
No. 619,892, which describes materials which produce cyan, magenta and yellow dyes as a function of exposure to three regions of the infrared spectrum (sometimes referred to as "false" sensitization). . Dyes with overlapping spectral sensitivity curves often yield a combined curve whose sensitivity at each wavelength in the overlap region is approximately equal to the sum of the sensitivities of the individual dyes. Thus, using a combination of dyes with different maxima, it is possible to achieve a spectral sensitivity curve with a maximum intermediate between the sensitization maxima of the individual dyes.

Supersensitization (ie, spectral sensitization in a given spectral region is greater than sensitization resulting from any concentration of the dye alone in the plurality of dyes or sensitization resulting from the effect of adding the plurality of dyes). ) Can be used. Supersensitization is accomplished by selecting a combination of spectral sensitizing dyes and other additives (eg, stabilizers and antifoggants, development accelerators or inhibitors, coating aids, optical brighteners and antistatic agents). Can be achieved using Any one of several mechanisms, as well as compounds that ensure supersensitization, are described by Gilma
n PhotographicScience and Engineering, Vol. 18,
It is discussed in 1974, pp. 418-430.

The spectral sensitizing dyes can also act on the emulsion in other ways. For example, spectral sensitizing dyes can increase photographic sensitivity in the spectral region where they are inherently sensitive. U.S. Patent No. 2,13 to Brooker et al.
No. 1,038, U.S. Pat. No. 3,501,310 to Illingsworth et al., Webster.
Et al., U.S. Pat. No. 3,630,749;
As disclosed in U.S. Pat. No. 3,718,470 to Ce et al. and U.S. Pat. No. 3,930,860 to Shiba et al., spectral sensitizing dyes can also be used as antifoggants or stabilizers; They can also act as development accelerators or inhibitors, reducing or nucleating agents, and halogen or electron acceptors.

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

[0077] Spectral sensitizing dyes can be added at any stage during emulsion preparation. Wall's Phot
ographic Emulsions, American Photographic Publishi
ng Co., Boston, 1929, p. 65; Hill U.S. Pat. No. 2,735,766; Philippaert.
et al., U.S. Pat. No. 3,628,960, Loc.
As described in U.S. Patent No. 4,225,666 to Ker et al. and Research Disclosure, Vol 181, May 1979, Item 18155, and published European Patent Application 301508 by Tani et al. They can be added at the beginning of the precipitation or during the precipitation.
U.S. Pat. No. 4,439,520 to Kofron et al., U.S. Pat. No. 4,520,09 to Dickerson.
No. 8, Maskasky US Pat.
They can be added prior to or during chemical sensitization, as described in US Pat. No. 5,501 and in the above cited specification such as Philippaerts.
Published European Patent Application No. 287100 to Asami et al.
They can be added prior to or during emulsion washing, as described in US Pat. U.S. Pat. No. 2,912,34 to Collins et al.
The dye can be mixed directly before application, as described in US Pat. As described in Dickerson, cited above, small amounts of iodide can be adsorbed on the emulsion grains to promote aggregation and adsorption of spectral sensitizing dyes. As described by Dickerson, the dye stain after processing can be reduced by bringing the high iodide grains closer to the dyed emulsion layer. According to their solubility, spectral sensitizing dyes
Water or a solution of a solvent such as methanol, ethanol, acetone or pyridine, dissolved in the surfactant solution described in U.S. Pat. No. 3,822,135 to Sakai et al. Patent No. 3,469,987 and JP-A-46-24
No. 185, can be added to the emulsion. As described in published European Patent Application No. 302528 to Mifune et al., Dyes are selectively adsorbed to specific crystal faces of emulsion grains as a means of limiting chemical sensitization centers to other crystal faces. be able to.
Published European Patent Application No. 270 to Miyasaka et al.
As described in US Pat. Nos. 079, 270082 and 278510, spectral sensitizing dyes can be used with poorly adsorbed luminescent dyes.

The selection of a particular spectral sensitizing dye will now be described: SS-1 Anhydro-5'-chloro-3'-di- (3-sulfopropyl) naphtho [1,2-d] -thiazolothiocyanine Hydroxide, sodium salt SS-2 anhydro-5'-chloro-3'-di- (3-sulfopropyl) naphtho [1,2-d] -oxazolothiocyanin hydroxide, sodium salt SS-3 anhydro-4 , 5-benzo-3'-methyl-4'-phenyl-1- (3-sulfopropyl) naphtho [1,2-
d] -Thiazolothiazolocyanine hydroxide SS-4 1,1'-diethylnaphtho [1,2-d] thiazolo-
2'-Cyanine bromide SS-5 Anhydro-1,1'-dimethyl-5,5'-di- (trifluoromethyl) -3- (4-sulfobutyl) -3 '
-(2,2,2-trifluoroethyl) benzimidazolocarbocyanine hydroxide SS-6 anhydro-3,3 '-(2-methoxyethyl) -5
5'-diphenyl-9-ethyloxacarbocyanine,
Sodium salt SS-7 Anhydro-11-ethyl-1,1′-di- (3-sulfopropyl) naphtho [1,2-d] -oxazolocarbocyanine hydroxide, sodium salt SS-8 Anhydro-5,5 '-Dichloro-9-ethyl-3,
3'-di- (3-sulfopropyl) -oxaselenacarbocyanine hydroxide, sodium salt SS-9 5,6-dichloro-3 ', 3'-dimethyl-1,1',
3-triethylbenzimidazolo-3H-indolocarbocyanine bromide SS-10 anhydro-5,6-dichloro-1,1-diethyl-3
-(3-Sulfopropylbenzimidazolooxacarbocyanine hydroxide SS-11 anhydro-5,5'-dichloro-9-ethyl-3,
3'-di- (2-sulfoethyl-carbamoylmethyl)
Thiacarbocyanine hydroxide, sodium salt SS-12 Anhydro-5 ', 6'-dimethoxy-9-ethyl-5
-Phenyl-3- (3-sulfobutyl) -3 ′-(3-
Sulfopropyl) -oxathiacarbocyanine hydroxide, sodium salt SS-13 Anhydro-5,5'-dichloro-9-ethyl-3-
(3-phosphonopropyl) -3 '-(3-sulfopropyl) thiacarbocyanine hydroxide SS-14 anhydro-3,3'-di- (2-carboxyethyl)
-5,5'-Dichloro-9-ethyl-thiacarbocyanine bromide SS-15 Anhydro-5,5'-dichloro-3- (2-carboxyethyl) -3 '-(3-sulfopropyl) thiocyanine, sodium salt SS-16 9- (5-Barbituric acid) -3,5-dimethyl-3 '
-Ethyltelluriacarbocyanine bromide SS-17 anhydro-5,6-methylenedioxy-9-ethyl-
3-methyl-3 '-(3-sulfopropyl) tellurciacarbocyanine hydroxide SS-18 3-ethyl-6,6'-dimethyl-3'-pentyl-
9,11-neopenthylene azicarbocyanine bromide SS-19 anhydro-3-ethyl-9,11-neopenthylene-
3 '-(3-sulfopropyl) -thiadicarbocyanine hydroxide SS-20 Anhydro-3-ethyl-11,13-neopenthylene-3'-(3-sulfopropyl) -oxathiatricarbocyanine hydroxide, sodium Salt SS-21 Anhydro-5-chloro-9-ethyl-5'-phenyl-3 '-(3-sulfobutyl) -3- (3-sulfopropyl) oxacarbocyanine hydroxide, sodium salt SS-22 Anhydro-5 , 5'-Diphenyl-3,3'-di-
(3-Sulfobutyl) -9-ethyl-oxacarbocyanine hydroxide, sodium salt SS-23 Anhydro-5,5'-dichloro-3,3'-di- (3
-Sulfopropyl) -9-ethyl-thiacarbocyanine hydroxide, triethylammonium salt SS-24 Anhydro-5,5'-dimethyl-3,3'-di- (3
-Sulfopropyl) -9-ethyl-thiacarbocyanine hydroxide, sodium salt SS-25 Anhydro-5,6-dichloro-1-ethyl-3- (3
-Sulfobutyl) -1 '-(3-sulfopropyl) benzimidazolonenaphthothio [1,2-d] thiazolocarbocyanine hydroxide, triethylammonium salt SS-26 Anhydro-11-ethyl-1,1'- Di- (3-sulfopropyl) naphtho [1,2-d] oxazolocarbocyanine hydroxide, sodium salt SS-27 Anhydro-3,9-diethyl-3'-methylsulfonylcarbamoylmethyl-5-phenyloxathiacarbo Cyanine p-toluenesulfonate SS-28 Anhydro-6,6'-dichloro-1,1'-diethyl-3,3'-di- (3-sulfopropyl) -5,5'-
Bis (trifluoromethyl) benzimidazolocarbocyanine hydroxide, sodium salt SS-29 Anhydro-5'-chloro-5-phenyl-3,3'-
Di- (3-sulfopropyl) oxathiacarbocyanine hydroxide, sodium salt SS-30 Anhydro-5,5'-dichloro-3,3'-di- (3
-Sulfopropyl) thiocyanine hydroxide, sodium salt SS-31 3-ethyl-5- [1,4-dihydro-1- (4-sulfobutyl) pyridine-4-ylidene] rhodanine, triethylammonium salt SS-321- Carboxyethyl-5- [2- (3-ethylbenzoxazoline-2-ylidene) -ethylidene] -3-phenylthiohydantoin SS-33 4- [2-((1,4-dihydro-1-dodecylpyridine-ylidene) ) Ethylidene] -3-phenyl-2-isoxazolin-5-one SS-34 5- (3-ethylbenzoxazolin-2-ylidene)
-3-Phenylrhodanine SS-35 1,3-Diethyl-5-{[1-ethyl-3- (3-sulfopropyl) benzimidazoline-2-ylidene] ethylidene} -2-thiobarbituric acid SS-36 5- [2- (3-ethylbenzoxazoline-2-ylidene) ethylidene] -1-methyl-2-dimethylamino-4-oxo-3-phenylimidazolium p-toluenesulfonate SS-37 5- [2- ( 5-carboxy-3-methylbenzoxazoline-2-ylidene) ethylidene] -3-cyano-4
-Phenyl-1- (4-methylsulfonamido-3-pyrrolin-5-one SS-38 2- [4- (hexylsulfonamido) benzoylcyanomethine] -2- [2- {3- (2-methoxyethyl) )
-5-[(2-methoxyethyl) sulfonamido] -benzoxazoline-2-ylidenediethylidene] acetonitrile SS-39 3-methyl-4- [2- (3-ethyl-5,6-dimethylbenzotellrazoline- 2-ylidene) ethylidene]-
1-phenyl-2-pyrazolin-5-one SS-40 3-heptyl-1-phenyl-5- {4- [3- (3-
Sulfobutyl) -naphtho [1,2-d] thiazoline]-
2-butenylidene} -2-thiohydantoin SS-41 1,4-phenylene-bis (2-aminovinyl-3-methyl-2-thiazolinium) dichloride SS-42 Anhydro-4- {2- [3- (3- Sulfopropyl)
Thiazoline-2-ylidene] -ethylidene {-2-} 3
-[3- (3-Sulfopropyl) thiazoline-2-ylidene] propenyl-5-oxazolium, hydroxide, sodium salt SS-43 3-carboxymethyl-5- {3-carboxymethyl-
4-oxo-5-methyl-1,3,4-thiadiazoline-2-ylidene) ethylidene] thiazoline-2-ylidene} rhodanine, dipotassium salt SS-44 1,3-diethyl-5- [1-methyl-2 − (3,5-
Dimethylbenzotellrazolin-2-ylidene) ethylidene] -2-thiabarbituric acid SS-45 3-methyl-4- [2- (3-ethyl-5,6-dimethylbenzotellrazolin-2-ylidene) -1 -Methylethylidene] -1-phenyl-2-pyrazolin-5-one SS-46 1,3-diethyl-5- (1-ethyl-2- (3-ethyl-5,6-dimethoxybenzotellrazolin-2- Iridene) ethylidene] -2-thiobarbituric acid SS-47 3-ethyl-5-{[(ethylbenzothiazoline-2-
(Ylidene) -methyl]-[(1,5-dimethylnaphtho [1,2-d] selenazoline-2-ylidene) methyl]
Methylene {rhodanine SS-48 5- {bis [(3-ethyl-5,6-dimethylbenzothiazoline-2-ylidene) -methyl] methylene} -1,
3-Diethyl-barbituric acid SS-49 3-Ethyl-5-{[(3-ethyl-5-methylbenzotellrazolin-2-ylidene) -methyl]-[1-ethylnaphtho [1,2-d]- Tellurazoline-2-ylidene) methyl] methylene} rhodanine SS-50 anhydro-5,5'-diphenyl-3,3'-di-
(3-Sulfopropyl) thiocyanine hydroxide, triethylammonium salt SS-51 Anhydro-5-chloro-5'-phenyl-3,3'-
Di- (3-sulfopropyl) thiocyanine hydroxide, triethylammonium salt Additional suitable spectral sensitizing dyes are included in the examples.

The instability (ie, fog) that increases the maximum density of negative working emulsion coatings can be improved by adding stabilizers, antifoggants, anti-kinks, latent image stabilizers and similar additives to the emulsion and adjacent layers. In addition, it can be prevented by incorporating before application. Many antifoggants effective for the emulsion used in the present invention can be used in a developer, and C.I.
E. FIG. K. Meer's The Theory of Photographic Proce
ss, 2nd edition, Macmillan, 1954, pp. 677-680, classified under a few general headings.

To avoid such instability in emulsion coatings, stabilizers and antifoggants can be used,
They include, for example, halide ions (eg, bromide salts), US Pat.
No. 63, chloroparadate (chlor)
opalladate) and chloropalladit
e), Jones U.S. Pat. No. 2,839,405 and Sidebotam U.S. Pat.
Water soluble inorganic salts of magnesium, calcium, cadmium, cobalt, manganese and zinc described in US Pat. No. 8,709 to Allen et al.
The mercury salt described in US Pat. No. 8,663, Brown
and British Patent No. 1,336,570 and P.
selenol and diselenide, described in UK Patent 1,282,303 to Ollet et al., All.
U.S. Patent No. 2,694,716 to Br et al.
U.S. Pat. No. 2,131,038 to Oaker et al., U.S. Pat. No. 3,342,596 to Graham, and U.S. Pat. No. 3,954,478 to Arai et al.
Quaternary ammonium salts described in US Pat.
Azomethine desensitizing dyes as described in U.S. Pat. No. 3,630,744 to Hers et al .; U.S. Pat. No. 3,220,839 to Herz et al. and U.S. Pat. No. 2,514,650 to Kott. Isothiurea derivatives described in US Pat. No. 3,565,625 to Scavron; thiazolidine described in US Pat. No. 3,274,002 to Maffet; Peptide derivatives, Welsh U.S. Pat. No. 3,161,515 and Hood
Pyrimidine and 3-pyrazolidone, as described in U.S. Pat. No. 2,751,297, Balda
Azotriazoles and azotetrazoles described in US Pat. No. 3,925,086 to Ssarri et al., US Pat. No. 2,444,6 to Heimbach.
No. 05, Knott US Pat. No. 2,933,3.
No. 88, Williams, U.S. Pat.
2,512, Research Disclosure, Vol. 134,
June 1975, Item 13452 and Vol. 148, 1976
August 148, item 14851, and azaindenes (especially tetraazaindenes), as described in UK Patent No. 1,338,567 to Nepker et al.
U.S. Pat. No. 2,403,927 to Ke et al.
No. 3,266,897, Research Disclosure, Vol. 116, December 1973, Item 11684, U.S. Pat. No. 3,39 to Luckey, et al.
Mercaptotetrazole, mercaptotriazole and mercapdiazole, described in US Pat. No. 7,987 and Salein, US Pat. No. 3,708,303; Peterson et al., US Pat.
No. 71,229 and the above Research Disclosur
e, azoles described in item 11684, She
U.S. Pat. No. 2,319,090 to Ppard et al., U.S. Pat. No. 2,152,460 to Birr et al., Research Disclosure, Item 13452, supra, and French Patent 2,296,204 to Dostes et al.
Purines described in US Pat. No. 3,926,635 to Salek et al., And 1,3-dihydroxy (and / or 1,3-carbamoxy) -2-methylenepropane described in US Pat. , And Gunt
Herr et al., U.S. Pat. No. 4,661,438, tellurazole, tellrazoline, tellrazolinium and tellurazolium salts, Gunther U.S. Pat. No. 4,581,330 and Przyk.
No. 4,661,43 to Lek-Elling et al.
No. 8 and 4,677,202 are aromatic oxatellazidinium salts. Miyo
The elemental sulfur described in published European Patent Application 294,149 to Shi et al. and published European Patent Application 297804 to Tanaka et al.
High chloride emulsions can be stabilized by the presence of thiosulfonates (especially during chemical sensitization) described in published European Patent Application 293917 to Kawa et al.

Particularly useful stabilizers for gold sensitized emulsions are benzothiazole, benzoxazole, naphthothiazole and US Pat. No. 2,595 to Yutzy et al.
Water soluble gold compounds of certain merocyanine and cyanine dyes described in US Pat. No. 7,915 and sulfinamides described in US Pat. No. 3,498,792 to Nishio et al.

Particularly effective stabilizers in layers containing poly (alkylene oxide) are described in US Pat. No. 2,716,062 to Carroll et al., British Patent 1,46.
No. 6,024 and U.S. Pat.
No. 929,486 (especially in combination with Group VIII noble metals or resorcinol derivatives), the quaternary ammonium described in Piper US Pat. No. 2,886,437. Salt, Maffet US Patent 2,953,45
The water-insoluble hydroxide described in the specification of No. 5, Smith
U.S. Patent Nos. 2,955,037 and 2,95
The phenol described in US Pat. No. 5,038, Ders
ethylene diurea, as described in US Pat. No. 3,582,346 to Ch.
Barbituric acid derivatives described in US Pat. No. 7,290, borane described in Biglow, U.S. Pat. No. 3,725,078;
3-pyrazolidinone described in US Pat. No. 158,059 and British Patent No. 988,052 to Butler et al.
Aldoximines, amides, anilides and esters described in US Pat.

The high chloride {100} tabular grain emulsions described herein can be prepared by the method of Kennard et al., US Pat.
Additives such as the sulfocatechol type compounds described in US Pat. No. 36,652, aldoximine described in UK Patent 623,448 to Carroll et al.
By incorporating meta- and polyphosphates described in U.S. Pat. No. 2,239,284 to Draisbach and carboxylic acids such as ethylenediaminetetraacetic acid described in British Patent No. 691,715. In addition, desensitization caused by a small amount of metal such as copper, lead, tin, and iron can be prevented.

In layers containing synthetic polymers of the type used as a vehicle and to improve coverage, particularly effective stabilizers are the monovalent and polyvalent monomers described in Forsgard US Pat. No. 3,043,697. Phenols, British Patent 897,497 and British Patent 1,039,471 to Stevens et al.
And the quinoline derivatives described in US Pat. No. 3,446,618 to Dersch et al.

Particularly useful stabilizers for protecting the emulsion layer against bicolor fog are described in US Pat. Nos. 3,679,424 and 3,820,998 to Barbier et al. Additives such as salts of nitrones, Wi
mercaptocarboxylic acids described in U.S. Pat. No. 3,600,178 to E. J. B
Irr Stabilization of Photographic Silver Halid
e Emulsions, Focal Press, London, 1974, pages 126-218.

Particularly useful stabilizers for protecting the emulsion layer against development fog are British Patent 1,356,142 to Bloom et al. And US Pat.
No. 5,699, Rogers, U.S. Pat.
Additives such as azabenzimidazole described in US Pat. No. 3,649,267 to Carlson et al., US Pat. No. 2,131,038 to Brooker et al., Laud. U.S. Patent Nos. 2,704,721 to Rogers et al., U.S. Patent No. 3,265,498 to Rogers et al. No. 2,432,864, Rauch et al., U.S. Pat. No. 3,081,170, Weyerts et al., U.S. Pat. No. 3,260,597, Grassho
ff et al., US Pat. No. 3,674,478 and Arond US Pat. No. 3,706,557 (eg, mercaptotetrazole); Herz et al., US Pat. 3,2
The isothiourea derivatives described in US Pat. No. 20,839, and von Kong US Pat.
Thiodiazole derivatives described in US Patent No. 028 and British Patent No. 1,186,441 to von Kong et al.

When an aldehyde type curing agent is used,
Mono- and polyhydric phenols of the type described in U.S. Pat. No. 2,165,421 to Sheppard et al., And nitros of the type disclosed in British Patent 1,269,268 to Rees et al. Substituted compounds,
Poly (alkylene oxide) as described in Valbusa GB 1,151,914;
and U.S. Pat.
Such as mucohalogenic acid in combination with urazole described in 232,764, or further in combination with maleic hydrazide described in US Pat. No. 3,295,980 to Rees et al. The emulsion layer can be protected by a suitable antifoggant.

To protect the emulsion layer coated on a linear polyester support, paravanic acid, hydantoic hydrazide and urazole, as described in Anderson et al., US Pat. No. 3,287,135, and two symmetrical Additives may be used, such as pirazines having a 6-membered cyclic carbon which are condensed in general, especially those in combination with aldehyde-type hardeners described in US Pat. No. 3,396,023 to Rees et al. .

The kink desensitization of the emulsion was determined by the method described in US Pat. No. 2,628,167 to Overman, thallous nitrate, US Pat. No. 2,759,8 to Jones et al.
Compounds of the type disclosed in U.S. Pat. Nos. 21 and 2,759,822; polymer crystal lattices and dispersions;
search Disclosure, Vol. 116, December 1973, item
No. 11684, azole and mercaptotetrazole hydrophilic colloid dispersions of the type disclosed in US Pat. No. 3,033,680 to Milton et al., Plasticized gelatin compositions of the type disclosed in Water soluble copolymers of the type disclosed in U.S. Pat. No. 3,536,491;
Polymer crystal lattice prepared by emulsion polymerization in the presence of poly (alkylene oxide) disclosed in US Pat. No. 2,032, and Rakoczy US Pat.
It can be reduced by incorporating a gelatin graft copolymer of the type disclosed in US Pat. No. 7,861.

If the color photographic element is to be processed at a high temperature bath or high drying temperature, as in a high speed access processor, pressure insensitivity and / or increased fog may be reduced by Abbott et al., US Pat. No. 3,295,97.
No. 6, Barnes et al., US Pat.
No. 971 in Salesin, US Pat. No. 3,70
8,303, Yamamoto et al., U.S. Pat. No. 3,615,619, Brown et al., U.S. Pat. No. 3,623,873, Taber U.S. Pat. No. 3,671,258. U.S. Pat. No. 3,791,830 to Abele, Research Disclosure,
Vol. 99, July 1972, Item 9930, Florens
Et al., U.S. Patent No. 3,843,364;
M. et al., U.S. Pat. No. 3,867,152, Ada
Additives, vehicles, cures as described in US Pat. No. 3,967,965 to Ch. et al. and US Pat. Nos. 3,947,274 and 3,954,474 to Mikawa et al. It can be controlled by the selected combination of agents and / or processing conditions.

The p, which is known to prevent latent image fading,
In addition to increasing the H or lowering the pAg of the emulsion and adding gelatin, Ezekiel's British Patent Nos. 1,335,923 and 1,378,35.
No. 4, No. 1, 378, 654 and No. 1, 391, 6
No. 72, British Patent No. 1,39 to Ezekiel et al.
No. 4,371, U.S. Pat. No. 3,843,372 to Jefferson, U.S. Pat. No. 1,412,294 to Jefferson et al. And Thur.
The amino acids described in Stone, UK Patent No. 1,343,904; U.S. Pat.
Carbonyl-bisulfite addition products in combination with hydroxybenzene or aromatic amine developing agents, described in US Pat. No. 3,447,926 to Beckett et al. Cycloalkyl-1,3-dione, a catalase-type enzyme described in U.S. Pat. No. 3,600,182 to Matejec et al., And described in U.S. Pat. No. 3,881,933 to Kumai et al. A halogen-substituted curing agent in combination with certain cyanine dyes,
US Pat. No. 3,386,831 to Hong et al .; US Pat. No. 3,955 to Arai et al.
Alkenyl benzothiazolium salts described in U.S. Pat. No. 4,478, Thurston, British Patent 1,30
No. 8,777, and Ezekiel et al., British Patents 1,347,544 and 1,353,527, the hydroxy-substituted benzylidene derivatives described in Sutherns, U.S. Pat. No. 3,519,4.
No. 3,639, Mercapto-substituted compounds of the type disclosed in US Pat.
A metal-organic complex of the type disclosed in US Pat.
penkiillin derivatives described in Zekiel, UK Patent 1,389,089; propynylthio derivatives, such as benzimidazole, pyrimidine, etc., described in von Konig et al., US Pat. No. 3,910,791; U.S. Pat. No. 3,901,71
No. 3,881,933 to the combination of the iridium and rhodium compounds disclosed in US Pat.
No. 9, thiazolidine derivatives described in Ezekiel, UK Patent No. 1,458,197, and Research.
Latent image stabilizers such as thioether-substituted imidazoles described in Disclosure, Vol. 136, August 1975, Item 13651 can be incorporated.

The dye image providing compounds incorporated into the color photographic elements of the present invention can take any convenient conventional form. Dye image providing compounds useful in color photographic elements are described in Research Disclosure, Item 30 above.
The dye image providing compounds described in Section VII of 8119 are typically dye image forming couplers (hereinafter "couplers"), but other dye image providing compounds such as dye redox releasing compounds, dye development Compounds, oxichromic developing agents, or bleachable dyes or dye precursor compounds are also contemplated. Dye redox emitters, dye developing agents, and oxychrome developing agents useful in color photographic elements are described in The theory of the Photographic Process, Chapter 4.
Edition, THJames, Macmillan, New York, 1977, Chapter 12,
It is described in Section V and Research Disclosure, Item 308119, Section XXIII above. Dye compounds useful in color photographic elements used in dye bleaching are described in The Theory of the Photographic Process,
It is described in 4th Edition, Chapter 12, Section IV.

The coupler compound is a coupler component COUP
And a coupling reaction with an oxidized color developing agent to form an image dye. The coupler compound can additionally contain a group (referred to as a coupling-off group) that is bonded to the coupler component by a bond that is broken during the reaction between the coupler compound and the oxidized color developing agent. The coupling off group can be a halogen or an organic radical, such as chloro, bromo, fluoro, and iodo, attached to the coupler component by an atom such as oxygen, sulfur, nitrogen, phosphorus, and the like.

The following are patent specifications and publications describing representative coupler compounds containing a COUP group useful in the present invention. Couplers that react with oxidized color developing agents to form cyan dyes are described in the following representative patents and publications: US Pat. No. 2,772,1.
No. 62, No. 2,895,826, No. 3,002,83
Nos. 6, 3,034, 892 and 2,474, 293
No. 2,423,730, 2,367,531
Nos. 3,041,236 and 4,333,999
No., "Farbkupplereine Literaturubersicht", Agfa M
Published by Itteilungen, Band III, pp. 156-175 (19
61), and Research Disclosure above, item 3
Section VII D of 08119. Preferred couplers are phenols and naphthols.

Couplers which react with oxidized color developing agents to form magenta dyes are described in the following representative patent specifications and publications: US Pat. No. 2,600,7
No. 88, No. 2,369,489, No. 2,343,70
No. 3, 2,311,082, 3,152,896
Nos. 3,519,429 and 3,062,653
No. 2,908,573, “Farbkupplereine Lite
raturubersicht ", published by Agfa Mitteilungen, Band II
I, pages 126-156 (1961), and Resea, supra.
rch Disclosure, section VII D of item 308119
. Preferred couplers are pyrazolones and pyrazolotriazoles.

Couplers which react with oxidized color developing agents to form yellow dyes are described in the following representative patent specifications and publications: US Pat.
No.57, No.2,407,210, No.3,265,50
No. 6, 2,298,443 and 3,048,194
No. 3,447,928, “Farbkupplereine Lite
raturubersicht ", published by Agfa Mitteilungen, Band II
I, pages 112-126 (1961), and Resea, supra.
Section VII D of rch Disclosure, item 308119.
Preferred couplers are acylacetamides, such as benzoylacetamides, and pivaloylacetamides.

In a preferred form, the color photographic elements of the present invention can be used to make color prints for viewing. If the color photographic element of the present invention is to be used as a photographic film (i.e., to produce an image that is printed sequentially using another element), then in addition to the dye image forming coupler, Research Disclosur
e, releasing masking couplers, as disclosed in section VII, subsection G of item 308119, and photographically useful groups, such as development inhibitors, as disclosed in section VII, subsection F It is preferable to incorporate couplers that improve the image quality.

If necessary, color photographic elements can be
Disclosure, Vol. 343, November 1992, item 34390
Can be included. The color photographic element can be imagewise exposed by any of the conventional techniques used. Possible exposures include those described in Research Disclosure, Item 308119, supra, Section XVIII and publications therein.

Apart from high chloride {100} tabular grain emulsions, color photographic elements and their processing following imagewise exposure are any convenient conventional known to be useful in redox amplified dye image formation. It can also take the form. Redox-amplified dye image generation, and color photographic elements specifically intended for redox-amplified dye image generation processing,
Bissonette, U.S. Pat. No. 3,748,138.
No. 3,826,652, 3,847,619
Nos. 3,856,524 and 3,862,842
Nos. 3,923,511 and 3,989,526
No. 4,002,477, 4,088,486
No. 4,089,685, 4,097,278
No. 4,146,395, each specification; Tra
vis US Pat. No. 3,765,891; Mt.
US Patent Nos. 3,674,490 and 3,776,730 to Eject; U.S. Patent No. 3,822,129 to Dunn et al .; U.S. Patent Nos. 3,904,413 to Mowrey. U.S. Pat. No. 4,022,616 to Barr et al .; Research Disclosure, Vol. 116, December 1973.
Mon, item 311660; Research Disclosure, Vol. 14
8, August 1976, items 14836, 14846 and 14847
(Which is incorporated herein by reference). Note that Bissonette U.S. Pat. No. 4,089,685 discloses a preferred reversal process.

In the production of redox-amplified dye images, an oxidizing agent and a reducing agent are used which are inactive in the absence of silver but catalyzed by the developed silver to enter the redox action. The oxidized reducing agent generated by the redox reaction then reacts with the dye image providing compound to form a dye image. The most typical reducing agents are color developing agents (eg, p
-Phenylene-diamine). Typical preferred color developing agents are 4-amino-3-methyl-N, N-diethylaniline hydrochloride, 4-amino-3-methyl-N-ethyl-N- (methanesulfonamido) ethylaniline sulfate hydrate Compound, 4-amino-3-methyl-N-ethyl-N
-Hydroxyethylaniline sulfate, 4-amino-3-
(Methanesulfonamido) ethyl-N, N-diethylaniline hydrochloride and 4-amino-N-ethyl-N-
(2-methoxyethyl) -m-toluidine di-p-toluenesulfonic acid. The oxidized color developing agent generated by the redox reaction then reacts with a dye image providing compound (usually a coupler) to form a dye image.
When the dye image providing compound is a redox dye releasing agent, the reducing agent is an electron transfer agent (for example, aminophenol, 3-pyrazolidinone, p-phenylenediamine or reductone). Typical preferred redox dye releasing agents and electron transfer agents are described in Research Disclosure,
Vol. 151, November 1976, Item 15162.

Useful oxidizing agents can be selected from among transition metal ion complexes (eg, cobalt (III) and ruthenium (III) complexes containing amines and / or amine ligands). Cobalt hexaamine is a particularly preferred transition metal ion complex useful as an oxidizing agent. Peroxy compounds (eg, compounds that provide hydrogen peroxide and hydrogen peroxide such as alkali metal perborates, percarbonates, and periodates) are also useful as oxidizing agents. Hydrogen peroxide is a particularly preferred oxidation.
If necessary, a mixture of oxidizing agents can be used.

Development of an imagewise exposed color photographic element according to the present invention in a first processing solution, followed by redox-amplified dye image formation in a second processing solution, followed by undeveloped particles by fixing in a third processing solution. Removal and removal of developed silver by bleaching with a fourth processing solution can be performed. Combinations of bleach and fix baths (referred to as brick baths) are well known in the art and are specifically contemplated. One of the significant advantages of the present invention is that the low silver coverage of the color photographic element allows the silver bleaching step to be omitted. This means
Eliminate normal processing steps, which are generally regarded as least preferred, due to actual work and due to the environmental burden of the reaction products produced. The fixing step can also be eliminated because the silver coverage is low and retained silver is acceptable. However, since this step is generally not a burden, it is preferred to include fusing during the overall process.
Since the reducing agent used in the redox-amplified dye image forming step is often a silver halide developing agent itself, development and redox dye image formation can be performed in the same processing solution, thereby reducing processing. Simplification is allowed. In fact, it is possible to carry out the treatment entirely in a single bath (called a mono bath). The above cited patents describing the redox amplification process provide specific examples of monobass and their use. The relatively high solubility and development rate of high chloride emulsions, as well as higher chloride environmental tolerance than bromide or iodide ions, provide additional important advantages to the practice of this invention.

[0103]

The invention can be better appreciated by reference to the following specific examples. Example 1: High aspect ratio high chloride {100} tabular grain milk
Agent emulsion 1A 0.5 wt% of bone gelatin, 6 mmol of 3-amino -
A stirred reaction vessel containing 400 ml of a solution of 1H-1,2,4-triazole, 0.040 mol of sodium chloride and 0.20 mol of sodium acetate was prepared by:
The pH was adjusted to 6.1 at 55 ° C. 55 ° C
, 5.0 ml of 4 mol silver nitrate and 5.0 ml of 4 mol sodium chloride solution were simultaneously added at a rate of 5 ml / min each. Thereafter, the temperature of the mixture is increased at a constant rate to 1
Raised to 75 ° C. over 2 minutes and held at this temperature for 5 minutes. The pH was adjusted to 6.2, keeping this value within ± 0.1 and the flow of silver nitrate solution was 0.8 ml at 5 ml / min.
Started again until moles of silver were added. The flow of the NaCl solution was also resumed at the rate necessary to maintain a constant pAg of 6.64.

The resulting silver chloride emulsion comprised tabular grains having {100} major faces for 65% of the projected area of the total grain population. This tabular grain population has an average equivalent circular diameter (E
CD) 1.95 μm and average thickness 0.165 μm. The average aspect ratio was 11.8.

Emulsion 1B Except for stopping the precipitation when 0.4 mole of silver was added,
This emulsion was prepared similarly to Emulsion 1A. The resulting emulsion consisted of tabular grains having {100} major faces for 65% of the projected area of the total grain population. The tabular grain population has an average ECD of 1.28 μm and an average thickness of 0.130 μm.
m. The average aspect ratio was 9.8.

Emulsion 2 pH = 6.1 nucleation, pH ~ / = 3.6 During the last 95% of the growth silver addition, the pH of the reaction vessel was set to 3.
This emulsion was prepared in the same manner as in Emulsion 1B, except that the emulsion was adjusted to 6. The resulting emulsion accounts for 60% of the projected area of the total grain population.
But consisted of tabular grains having {100} major faces.
This tabular grain population had an average ECD of 1.39 μm and an average thickness of 0.180 μm. The average aspect ratio is
7.7.

[0107]Emulsion 3 High aspect ratio AgBrCl
(10% Br) {100} tabular grain emulsion The salt solution is 3.6 mol NaCl and 0.4 mol N
This emulsion was prepared in the same manner as in emulsion 1B except that the emulsion was aBr.
Prepared. The resulting silver bromochloride (10% Br) emulsion was
52% of the projected area of the child group has a {100} plane.
It consisted of plate-like particles. This tabular grain population has an average
Has an ECD of 1.28 μm and an average thickness of 0.115 μm
Was. The average aspect ratio was 11.1.

Emulsion 4 {100} tabular grain nucleating agent
3,5-diamino-1,2,4-triazole {100} as a tabular grain nucleating agent, except that 3,5-diamino-1,2,4-triazole (2.4 mmol) was used. This emulsion was prepared similarly to Emulsion 1A.

The resulting silver chloride emulsion consisted of tabular grains having {100} major faces for 45% of the projected area of the total grain population. This tabular grain population has an average ECD of 1.54
μm and an average thickness of 0.20 μm. The average aspect ratio was 7.7.

Emulsion 5 {100} tabular grain nucleating agent
This emulsion was prepared in the same manner as in Emulsion 1A, except that imidazole (9.6 mmol) was used as an imidazole {100} tabular grain nucleating agent. The resulting silver chloride emulsion consisted of tabular grains having {100} major faces for 40% of the projected area of the total grain population. This tabular grain population has an average E
It had a CD of 2.20 μm and an average thickness of 0.23 μm.
The average aspect ratio was 9.6.

Emulsion 6 made without aromatic amine inhibitor
AgCl {100} tabular grains containing 0.25% by weight of a low methionine content (<4 μmol / g of gelatin) of bone gelatin and 400 ml of 0.008 mol of sodium chloride at 85 ° C., p.
Into a reaction vessel stirred at H6.2, 4 mol of silver nitrate solution at 5.0 ml / min and 4 mol of sodium chloride solution at a rate necessary to maintain the pCl at a constant value of 2.09. Added at the same time. When 0.20 mole of silver nitrate was added, the addition was stopped for 20 seconds and the pH was adjusted to 6.2 during the time of adding 15 ml of a 13.3% low methionine gelatin solution. The addition was started again until a total of 0.4 mol of silver nitrate had been added. The pH was kept constant at 6.2 ± 0.1 during the precipitation.

In the resulting silver chloride emulsion, 40% of the projected area of the whole grain population consisted of tabular grains having {100} major faces. This tabular grain population has an average ECD 2.18
μm and an average thickness of 0.199 μm. The average aspect ratio was 11.0.

Emulsion 7 high aspect ratio high chloride # 10
0 % tabular grain emulsion 3.5% by weight low methionine (oxidized) gelatin,
Two liters of the solution, containing a solution of 5.6 mmol sodium chloride and 0.15 mmol potassium iodide, were charged to the reaction vessel. While stirring the solution, 30 ml of a 2 molar silver nitrate solution and 30 ml of a 1.99 molar sodium chloride and 0.01 molar potassium iodide solution were added.
At the same time, they were added at a rate of 60 ml / min. The mixture is stirred for 10 minutes and a 0.5 molar silver nitrate solution 1.8
8 liters first at 8.0 ml / min for 40 minutes then 1
The flow rate was doubled over 30 minutes. 0.5 mole of Na
The Cl solution was added simultaneously at a rate necessary to keep the pCl constant at 2.32. To the resulting emulsion was added 20 g of phthalated gelatin, which was added to US Pat. No. 2,614,92.
No. 9, washing by the coagulation method and finally resuspending in 500 ml of a 1% gelatin solution,
Adjusted to 7. The total gelatin content was about 20 g / Ag mole.

75% of the total grain projected area consisted of tabular grains having {100} major faces. This population had an average diameter of 1.66 and an average thickness of 0.11 μm.

Control Emulsion 8 A control emulsion was prepared which was an AgBr tabular grain emulsion consisting of grains having an average diameter of 1.7 μm and an average thickness of 0.085 μm.

Control Emulsion 9 This emulsion was a silver chloride emulsion containing cubic grains having an average grain edge length of 0.6.

Control Emulsion 10 This emulsion was a silver chloride emulsion containing cubic grains having an average grain edge length of 0.75.

Illuminated Emulsion 11 3.52% by weight of low methionine gelatin, 0.0056
2030 ml of a solution containing mol sodium chloride and 3.35 × 10 ^-4 mol potassium iodide were placed in the reaction vessel with stirring. Iodide was incorporated to promote tabular grain nucleation, but was kept well below the amount required to significantly increase blue absorption. The contents of the reaction vessel were maintained at 40 ° C. and the pCl was 2.25.

While the solution was vigorously stirred, 40.6 ml of a 2.0 molar silver nitrate solution and 40.6 ml of a 2.00 molar sodium chloride solution were simultaneously added to each of 81.12 ml.
It was added at a rate of 2 ml / min. The mixture was then held for 4 minutes and the temperature remained at 40 ° C. 0.5 after holding
Mol silver nitrate solution and 0.5 mol NaCl solution,
The pCl is maintained at 2.25 and the rate is 4.83 ml / min.
Added simultaneously for 0 minutes. Thereafter, a 0.5 M solution of silver nitrate and a 0.5 M NaCl solution was added to maintain 10.83. The flow rate was increased linearly from ml / min to 16.73 ml / min and added simultaneously over 70 minutes.
This was followed by a 0.75M silver nitrate solution and 0.7
The 5M NaCl solution was used to maintain the pCl at 2.25 and the 16.73. ml over 90 minutes.

The resulting emulsion had an average ECD of 1.524 μm.
And a tabular grain emulsion having a {100} major surface and an average thickness of 0.148 μm.

Example 1 A 50 g portion (0.05 mol) of Emulsion 7 was stirred at 25 ° C. with H ₂ SO ₄ to pH 5.3 and with NaCl to pH 5.3.
Cl was adjusted to 2.06. Add 5 ml of 0.2 to this emulsion.
A molar NaBr solution was added at 0.5 ml / min. afterwards,
0.7 mmol / Ag mol of green spectral sensitizing dye, anhydro-5-chloro-9-ethyl-5'-phenyl-3'-
A solution containing (3-sulfobutyl) -3- (3-sulfopropyl) oxacarbocyanine hydroxide, triethylamine salt, and dye A was added. The temperature was raised to 40 ° C. and 4 × 10 ⁻⁶ mol / Ag mol of sodium thiosulfate and 2.6 × 10 ⁻⁶ mol / Ag mol of potassium potassium tetrachloride were added. The mixture was heated at 60 C for 15 minutes.
A portion of this emulsion is mixed with a cyan color coupler dispersion, gelatin, a surfactant and a hardener, and
1 was 5 × 10 ⁻³ mol. 0.011gAg /
Example coating 1 was made by coating on a paper support at m ² , 1.1 g coupler / m ² and 2.2 g gelatin / m ² .

In Control Emulsion 8, 0.7 mmol dye A / A
g mol were added, followed by 20 × 10 ^-6 mol / Ag mol of sodium thiosulfate and 13 × 10 ^-6 mol / Ag mol of potassium potassium tetrachloride. The mixture is brought to 60 ° C. for 15 minutes.
Heated for minutes. A portion of this emulsion was mixed with a cyan color coupler dispersion, gelatin, surfactant and hardener, and the NaCl was made up to 5 × 10 ^-3 mole. It was coated on a paper support with 0.011 g Ag / m ² , 1.1 g coupler / m ² and 2.2 g gelatin / m ² to form Control Coating 2.

Exposure and Processing Examples Coating 1 and Control Coating 2 were exposed through a 0-4.0 density step tablet to a 600 W, 3000 K degree tungsten light source for 0.1 second. The exposed coating film was developed at 20 ° C. for 10 seconds in a developer having the following composition. Developer composition: 4-amino-N-ethyl-N- (2-methoxyethyl) -m-toluidine p-Toluenesulfonate 10 g Potassium carbonate 20 g Potassium sulfite 4 g Distilled water was added to make 2 liters, and 30% immediately before use 20 ml of hydrogen peroxide were added. Thereafter, the coating was placed in a 1% acetic acid stop bath and washed with water. No bleaching or fixing was required. The results are shown in Table I.

Table I Coatings Dmin Dmax Relative Sensitivity Example 1 0.36 1.0 140 Control 2 0.12 0.4 100

Note that after just 10 seconds of development processing, example coating 1 provided significantly higher Dmax and photographic speed than control coating 2. This demonstrated that the redox-amplified dye image forming process using the high chloride {100} tabular grain emulsion was excellent.

Example 2 Yellow Monochrome Layer Emulsions 9, 10 and 11 were each optimally chemically and blue sensitized, then double coated with a dispersion incorporating a yellow dye forming coupler and subjected to a redox amplification process. An appropriate yellow single record was given. The silver coating amounts used are as shown in Table II. The prepared coatings were sensitometrically calibrated and exposed to light (0.1 second exposure time, using a 0.62 neutral density filter and a Wratten® 98 filter). This coating film was subjected to redox amplification treatment according to the redox amplifier formulation and processing order given below.

Formulation of 1.0 liter of redox amplifier: 1-hydroxyethylidene-1,1'-diphosphonic acid 0.6 g diethyltriamine-pentaacetic acid 2.0 ml K ₂ CO ₃ 10.0 g KBr 1.0 mg KCl 35 g diethylhydroxylamine (85%) 4.0 ml 4-N-ethyl-N- (β-methanesulfonamidoethyl) -o-toluidine sesquisulfate 3.5 g Add water to make 1000.0 ml. pH (27 ° C.), adjusted with KOH 10.3 Hydrogen peroxide 5.0 ml

Processing order: Development 32 ° C., 8 liter tank for 45 seconds Stop 15 g / l Sodium metabisulfite 30 seconds Bleaching / fixing (Ektacolor RA4®) 30 seconds Rinse 60 seconds

Thereafter, the yellow wedge on the treated material was read using a densitometer and the appropriate sensitometric parameters were calculated. These are shown in Table II.

Table II Emulsion Silver Amount Grain Volume Nucleus Dmin Dmax Contrast Sensitivity ** (mg / m ² ) (10 ⁹ ) * 9 47.1.270 52.2.082 2.093 2.608 193 10 59.0.422 33.4.126 2.129 2.908 209 11 51.9 .292 45.9 .104 2.146 2.726 231 * 1m in number ** this example and following examples of ² per particle concentrations that are measurements at the lowest perceptible concentration on Dmin

High chloride {100} tabular grain emulsion 11
Resulted in higher sensitivity than either of the control cubic grain emulsions 9 and 10, and all others were selected to produce coating and performance parameters just above and below the value of emulsion 11. I understand.

Example 3 Using redox amplification only for fixing
Lower yellow silver coverage and higher amplification
Nocro layer Sample emulsions 9, 10 and 11 were used again as described previously. The silver laydowns used are shown in Table III.
The prepared coatings were sensitometrically calibrated and exposed to light as described in Example 2. The coating was processed in the same redox process as in Example 2 except that a fixing step was incorporated instead of the bleach / fixing step. 4 to increase amplification
A development time of 60 seconds was used instead of 5 seconds. The outline of the processing order is as follows.

Processing order: Development 60 ° C. in an 8 liter tank at 32 ° C. Stopping 15 g / l Sodium metabisulfite 30 seconds Fixing (Flexicolor C41, trademark) 30 seconds Rinsing 60 seconds

Thereafter, the yellow wedge on the treated material was read using a densitometer and the appropriate sensitometric parameters were calculated. These are shown in Table III.

Table III Emulsion Silver Content Grain Volume Nucleus Dmin Dmax Contrast Sensitivity * (mg / m ² ) (10 ⁹ ) * 9 28.9.270 32.1.099 2.108 2.320 193 10 36.3.422 20.5.129 2.142 2.449 209 11 32.4. 292 28.6 .167 2.231 2.074 236 11 39.5 .292 35.0 .190 2.355 2.576 229

It can be seen that Emulsion 11 provided higher sensitivity than achieved with Controls 9 and 10. , Emulsion 1
Comparison of the control emulsion 10 with the two levels of 1 shows a higher Dmax and similar contrast.
Thus, in systems where developed silver is retained in the dye image, the advantage is maintained at reduced silver levels (see also Example 2).

Example 4 Multilayers Six types of multilayer color photographic papers were coated in the same manner as currently available silver chloride color papers. Sample Control Emulsion 10 and Emulsion 11, prepared as described above, were used for the yellow dye image-forming layer units at the following silver amounts (mg / m ² ): (Control Emulsion 10) 45.2, 64.
6, 83.9; (Emulsion 11) 37.7, 53.8, 6
9.9. A conventional red sensitized cubic grain silver chloride emulsion of 0.38 μm edge length was used at a silver loading of 32.3 mg / m ² for the cyan dye image forming layer units of these coatings; A sensitized 0.31 μm cubic grain silver chloride emulsion with an edge length of 0.31 μm was used at 37.7 mg / m ² silver for the magenta dye image forming layer units of these coatings.

Each color paper was applied to four different color wedges (giving red, green, blue and neutral exposure) Wratten® 2B + 60M + 60Y.
Exposure was made with a filter for 0.1 seconds on a sensitometer. Thereafter, the exposed coating film was subjected to redox amplification using the following formulation and processing order.

Formulation of 1.0 liter of redox amplifier: 1-hydroxyethylidene-1,1'-diphosphonic acid 0.6 g diethyltriamine-pentaacetic acid 2.0 ml K ₂ CO ₃ 25.0 g KBr 1.0 mg KCl 5 g diethylhydroxylamine (85%) 4.0 ml catechol disulfonic acid (Na) 0.60 g 4-N-ethyl-N- (β-methanesulfonamidoethyl) -o-toluidine sesquisulfate 3.5 g Water was added. To 1000.0 ml. pH (27 ° C.), adjusted with KOH 10.3 Hydrogen peroxide 5.0 ml

Processing order: Development 32 ° C., drum 45 seconds Stop 2% acetic acid 30 seconds Rinse 30 seconds Bleaching / fixing (Ektacolor RA4®) 30 seconds Rinse water 60 seconds

The yellow separation wedge on the treated material was then read using a densitometer and sensitometric parameters were calculated. These are shown in Table IV.

Table IV Emulsion Silver Amount Dmin Dmax Contrast Sensitivity * Sensitivity ** (mg / m ² ) 10 45.2.097 1.773 1.956 118 155 64.6.103 2.086 2.483 117 158 83.9.103 2.191 2.823 118 160 11 37.7.106 1.936 1.98 152 192 53.8.115 2.197 2.449 154 195 69.9.124 2.238 2.87 156 199 * Yellow separation wedge ** Neutral (unbalanced) wedge

As observed in the monochrome example, higher sensitivity was obtained with constant contrast and lower silver. For example, the result of the comparison of Emulsion C in a silver amount of control emulsion 10 to 69.9 mg / m ² of silver amount of 83.9mg / m ^2. Due to the very high blue speed difference observed between the color paper containing the high chloride {100} tabular grain emulsion and the comparative color paper, the neutral image was not well balanced, resulting in a neutral sensitizer. The metrology results could not be compared effectively. Adjust the exposure fill ratio,
Three types of coating films (control emulsion 1 with 83.9 mg / m ² silver amount)
0, and 53.8 mg / m ² and 69.9 mg / m
^{The two} silver emulsions 11) were given the same neutrality. The sensitometric parameters generated for these aligned neutral wedges are shown in Table V.

Table V Neutralized Blue Response (0.1 second exposure) Emulsion Silver Amount Dmin Dmax Contrast Shoulder Filtration n * Delta ** 10 83.9.117 2.441 3.145 1.816.354 50Y + 5M 0 11 53.8 .122 2.327 2.914 1.751 .390 105Y + 5M 55Y 11 69.9 .124 2.378 3.145 1.822 .378 120Y 70Y-5M * Kodak Color Compensation Filter ** Difference in Filtration

As previously observed, dye image amplification was
When performed on the yellow, magenta, and cyan dye image forming layer units, higher sensitivity (indicated by the higher yellow filtration required to produce combined neutrality) results in constant contrast and higher sensitivity. Maintained at low silver coverage.

Example 5 Single Color Recording and Fix Only Processing
Sample of multilayer color was compared in the comparison Table V of silver held by the paper, Control Emulsion 10 (83.9mg / m ² silver) and emulsions 11
(69.9 mg / m ² silver amount) and processed in a fix-only process (the processing sequence shown in Example 4 except that the bleach / fix step was replaced by sulfite fix). In this process, the developed silver image is held for each dye image forming layer. By aligning the wedges at a density of 2.0 (blue separation exposure in the case of the multilayer example) and measuring the undesired red and green absorption, it is possible to obtain a measurement limit for yellow dye decay caused by retained silver. It is possible. These are shown in Table VI. A similar experiment, Example 3
For the yellow single color record previously tested at. The results are shown in Table VII.

Table VI Multilayer Data Emulsion Silver Yellow Separation Yellow Separation Yellow Separation Blue Density Green Density Red Density 10 83.9 2.0 0.53 0.25 11 69.9 2.0 0.52 0.25 Table VII Yellow Single color recording data Emulsion Silver Blue density Green density Red density mg / m ² 9 28.9 2.00 0.43 0.22 10 36.3 2.00 0.45 0.23 11 32.4 2.00 0.45 0.24 11 39.5 2.00 0.45 0.24

From Tables VI and VII, very similar (especially red) unwanted absorptions were observed. This, contrary to the expectation based on the higher covering power of the tabular grain emulsions reported, did not result in the imaging disadvantages compared to the cubic grain emulsions from the retained unbleached silver. Explain that. When compared to cubic grain emulsions,
Instead of speed, the advantage of {100} tabular grain emulsions was obtained, with no significant loss in dye image quality due to retained silver.

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Peter Douglas Marsden Middlesex H. 26, UK, North Harrow, Southfield Park 49 (72) Inventor Joe Edward Muscasky United States of America, New York 14625, Rochester, Sherwood JP-A-4-233535 (JP, A) JP-A-58-95337 (JP, A) JP-A-51-88017 (JP, A) JP-A-3-137632 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03C 1/035 G03C 1/74 G03C 7/407

Claims (4)

(57) [Claims] 1. A color photographic element comprising a dye image forming layer unit comprising at least one silver halide emulsion and a dye image providing compound, wherein the total silver in the dye image forming layer unit is 200 mg / m ^2. And the emulsion comprises a silver halide grain population comprising at least 50 mol% chloride, based on total silver forming the grain population, and greater than 30% of the grain population projected area Proportions at least 2 each
Aspect ratio, thickness less than 0.3 μm, and ｛1
A color photographic element characterized by being occupied by tabular grains having parallel major faces lying in the 00 @ crystal plane. 2. The color photographic element of claim 1, further comprising tabular grains accounting for greater than 50% of the grain projected area. 3. A color photographic element according to claim 1, wherein the tabular grains have an average thickness of less than 0.2 μm. 4. The silver was difference <br/> raw silver halide emulsion is developed imagewise, using a developed silver for redox interactions when no silver is developed not the reaction of the oxidizing and reducing agents which are active with catalyst and the oxidized reducing agent by reacting the dye image providing compounds Ri by to form a dye image, any one of 請 Motomeko 1 to 3 Described in
Write <br/> method of producing a dye image image imagewise exposed color photographic element.