Chromogenic black-and-white photographic imaging systems

Description: TECHNICAL FIELD [Detailed description of the invention]

Cross-reference of related applications This application is a partial continuation of US Patent Application No. 810,311 filed December 19, 1991, which was previously filed. Field of invention The present invention relates to the configuration of a photographic system that forms a black-and-white image using a combination of cyan, magenta and yellow pigments. The dye is formed from a mixture of cyan, magenta and yellow pigment-forming couplers during the color-developing process, which forms a neutral image when reacted with an oxidized color-developing agent. .. Background of the invention The black-and-white image formed in the photographic process is generally formed by developing silver halide in a black-and-white developer to form a silver image. In order to reduce silver halide after exposure to silver metal, a black-and-white developer such as hydroquinone is usually used. Undeveloped silver halide is removed from the print by "fixing" with aqueous sodium thiosulfate. The silver metal that remains on the print constitutes the image. In the photographic industry, photographic finishers seeking to prepare both black and white and color photographs or prints must have separate processing systems; one for color and one for black and white, because For example, these two systems are incompatible. For photographic finishers, it would therefore be advantageous if there was something that could be prepared in either black and white or color materials in one process. Scheerer, U.S. Pat. No. 4,348,474 discloses a system that forms a black-and-white image by using one emulsion that is treated with three sensitizing dyes. Schneider, US Pat. No. 2,186,736, discloses the use of several color components in one layer for black-and-white image formation. Harsh, U.S. Pat. No. 2,592,514 discloses a color film in which couplers that form more than one color are present in the same layer of color film. There are products that have already been commercialized, in which black-and-white images are formed by the use of pancrosensitizing emulsions containing three types of spectrosensitizing dyes, color dye-forming couplers and one type of emulsion. There is. Since these pancrosensitized emulsions form an image after exposure and development of the coupler, they are often applied to a high-sensitivity layer and a low-sensitivity layer. Although the above products have been successful to some extent, they have not achieved a neutral image. In addition, the color reproduction of such materials is severely limited by the contrast range of the emulsion. Problems to be solved by the invention There is a need for high quality black and white photographic products suitable for development in color image forming systems. Furthermore, it is desirable to recover from the photographic prints used to form the black and white image, rather than using silver as part of the image and thus making it unrecoverable. Outline of the invention One object of the present invention is to provide a black-and-white image that can be developed by a color process. One object of the present invention is to provide a black-and-white image having a degree of color tone improved by using a color coupler and a conventional color treatment. The present invention generally comprises at least one layer of balanced cyan, magenta and yellow pigment-forming couplers containing at least one of blue sensitized silver halide particles and green sensitized silver halide particles. Achieved by providing photographic elements for forming a neutral image with silver halide particles. In one preferred embodiment, at least one layer of balanced cyan, magenta and yellow pigment-forming couplers with blue-sensitized silver halide particles, and balanced cyan, magenta with green-sensitized silver halide particles. And a photographic element having at least one layer of a yellow pigment-forming coupler is formed. In another preferred embodiment, a photographic element is formed that includes at least one layer of balanced cyan, magenta, and yellow pigment-forming couplers and blue-sensitized silver halide particles, and green-sensitized silver halide particles. .. Further, a method for forming a neutral black-and-white image by developing the above-mentioned elements of the present invention is provided. In a preferred embodiment, the invention is generally achieved by forming a multilayer consisting of a mixture of a coupler dispersion and an emulsion. In such a multilayer, at least one layer in which the silver halide emulsion is sensitized to blue light, one silver halide emulsion layer sensitive to red light, and sensitivity to green light. At least two layers are present so that there is one silver halide emulsion layer with. Each emulsion-containing layer also contains a mixture of cyan, magenta and yellow pigment-forming couplers, independent of the color sensitivity of silver halide. Furthermore, in order to obtain a black-and-white image that reproduces the brightness ratio of the scenery as seen by the human eye, the contrast ratio of the red-sensitive emulsion, the green-sensitive emulsion, and the blue-sensitive emulsion in the photographic element is about 2: 3: 1. Is advantageous. These contrast ratios were found to be similar to the relative response of the eye to changes in color brightness. This contrast ratio, however, can be changed to meet customer preference and to expand the range of contrast that can be achieved if a black-and-white or color negative print with varying contrast is to be produced. Similarly, relative contrast and tonal reproduction can be tailored by adjusting the coverage of silver halide and color couplers, for example, usually in current colors and black-and-white photographic films and prints. It is done in the paper system. Advantageous effects of the present invention The present invention has many advantages over the prior art. The photographic product of the present invention eliminates the need for an independent processing system to prepare black and white photographs by accurately reproducing color exposure in black and white. The black-and-white photographic system of the present invention further makes it possible to recover substantially all of silver from a black-and-white photographic image. Another advantage of this system is that the lightness ratio and tonal reproduction are more accurate than other systems that use a color coupler to form a black and white image. Another advantage is that if it is desirable to change the brightness and color of the black and white image, this can be achieved by using regular color filters while printing the negatives. A photographic print formed in accordance with the present invention will respond to changes in the filter light of colored light during printing in a direction that allows easy adjustment of color tone and lightness. This advantage cannot be obtained with other black-and-white photographic systems in which pancro or orthosensitive emulsion systems are used. A brief description of the drawing Figure 1 shows 30 different standard colors and 30 different standard colors when comparing Kodak Panalua M black and white photographic paper with Kodak Supra color photographic paper when making prints using the same negatives. It shows the reproduction of lightness vs. saturation for neutral density. In each case, the tail of the arrow represents the brightness and saturation values obtained with color photographic paper, while the head of the arrow and the extension of the arrow are when the negative is printed on Kodak Panalua M black and white photographic paper. Represents a change in saturation and lightness. FIG. 2 shows a comparison when Kodak Polycontrast III black and white photographic paper is used instead of Kodak Panalua M black and white photographic paper. FIG. 3 shows the change in brightness obtained when black and white photographic paper such as that described in the present invention is used instead of Kodak Panalua M photographic paper. Detailed description of the invention To create a black-and-white image using a mixture of dyes formed from the coupler, the image obtained after exposure and color development is neutral, and the cambium is to avoid having specific color habits. It is necessary to balance the ratio of couplers in. However, there are demands from the photographic market, according to which the desired reproduction color should not be neutral. For example, in order to accurately reproduce the tones of a "sepia" print, the ratio of couplers in the dispersion or the ratio of dispersions in the emulsion layer should be such that a favorable "sepia" color balance is obtained. It will need to be changed. It is also known that many "black and white photographic papers" based on the silver halide system currently on the market do not form a neutral image. Depending on the composition of the silver halide material and the properties of the black-white development process, a wide variety of hues of green, red, yellow or brown can be produced. Each has its own unique and distinctive color and photographic use. The term "balanced cyan, magenta and yellow pigment-forming couplers" means that those couplers are generally balanced to provide a neutral image. This neutral and balanced image will preferably be black and white for most applications. Also, according to the techniques of the present invention, it is possible to balance the images in order to give them sepia or slightly bluish tones, but still generally obtain neutral images. The present invention utilizes an oil-in-water dispersion containing a mixture of cyan, magenta and yellow pigment-forming couplers. It is also clear that independent dispersions containing cyan, magenta and yellow pigment-forming couplers can be used. In addition, other dispersion additives such as coupler solvents, auxiliary coupler solvents and / or dye stabilizers can be added. Dispersion additives such as latex polymers or hydrophobic polymers can also be added. The aqueous phase of the dispersion is composed of gelatin, a surfactant, and water. The composition of the oil phase portion of the dispersion forms a neutral image when processed in a color development bath, the density of which image changes only in proportion to the amount of silver developed in the process. It is adjusted to do so. If separate coupler dispersions are used, each dispersion is added to the layer in appropriate proportions to ensure that a neutral image is formed after exposure and development. According to one embodiment, the coupler dispersion can be applied in a multi-layer format as used in conventional color films or photographic papers after its preparation has been completed. However, there are two main differences; the first difference is that the same neutral pigment-forming coupler dispersion is applied to each emulsion-containing layer. Therefore, a neutral image is formed during color development in proportion to the amount of silver development, regardless of whether the element is exposed to red, green or blue light. After color development, post-development and undeveloped silver is removed from the element by bleaching and fixing, or more simply, by bricking (bleaching-fixing). The second difference is that the ratio of sensitized silver halide is adjusted in the elements so that the brightness of the subject to be reproduced in the original landscape is more accurately reproduced. This effect can be obtained by applying the spectrally sensitized silver halide layer in an amount corresponding to the relative sensitivity to light of the naked eye. It is generally accepted that the macroscopic response to red, green and blue light is in a ratio of about 2: 3: 1. The higher the number, the higher the sensitivity. Therefore, in the elements of the present invention, it is advantageous that the ratio of the amount of the red-sensitive emulsion to the amount of the green-sensitive emulsion to the amount of the blue-sensitive emulsion is also about 2: 3: 1. However, this ratio can be adjusted to any ratio depending on the needs and requirements of the photographic system. For example, a film designed for X-rays, usually applied on a blue support, is 2: 2: 1 or 3: 2: 1 to improve the visual process of contrast discernment. It may be selected by using the ratio. In the second aspect of the present invention, one layer containing silver halide particles sensitized to one or more colors of an oil-in-water dispersion containing a mixture of cyan, magenta and yellow pigment-forming couplers. Apply to. In this aspect, the silver halide particles are a mixture of particles that have been sensitized to be sensitive to various colors of light. Preferably, the silver halide emulsion contains blue-sensitized, green-sensitized, and red-sensitized silver halide particles. The element may contain only blue-sensitized and green-sensitized silver halide particles to form an ortho-sensitized element. The present invention can be embodied using materials commonly used in color photographic paper. As is well known, such photographic papers have couplers for forming yellow, cyan and magenta pigments. Since they are suitable for rapid processing, it is most common to mainly use silver chloride emulsions for color photographic paper. It is clear that other photographic systems require the use of emulsions other than silver chloride. Such a system, in fact, requires silver bromide, silver bromide, silver bromide or silver iodide salt. Emulsions are sensitized to light of wavelengths that should be absorbed by the particular layer in which they are present. For example, silver halide particles in the yellow layer will be most sensitive to blue light, and silver halide particles in the magenta layer will be most sensitive to green light. It is known to use sensitizing dyes to provide such emulsions. For a description of emulsion preparation, sensitizing dyes, antifoggants and stabilizers, couplers, dural agents, coating aids, and other commonly used materials for use in the formation of silver halide images, see December 1989. See the monthly research disclosure, # 308119. It is considered that the present invention can be embodied using any known material for use in silver halide color photography. Furthermore, it is conceivable that this technique would be satisfactory for use with future materials using pigment-forming couplers that form silver halides with yellow, cyan and magenta pigments. The following is a list of preferred cyan, magenta and yellow couplers for the present invention. Following the coupler, three preferred hydroquinone structures for the present invention are described.<img file="JPP3222467B2_D0001.tif" /><img file="JPP3222467B2_D0002.tif" /><img file="JPP3222467B2_D0003.tif" /><img file="JPP3222467B2_D0004.tif" /><img file="JPP3222467B2_D0005.tif" /><img file="JPP3222467B2_D0006.tif" /><img file="JPP3222467B2_D0007.tif" /><img file="JPP3222467B2_D0008.tif" /><img file="JPP3222467B2_D0009.tif" /><img file="JPP3222467B2_D0010.tif" /><img file="JPP3222467B2_D0011.tif" /><img file="JPP3222467B2_D0012.tif" /><img file="JPP3222467B2_D0013.tif" /><img file="JPP3222467B2_D0014.tif" /><img file="JPP3222467B2_D0015.tif" /><img file="JPP3222467B2_D0016.tif" /><img file="JPP3222467B2_D0017.tif" /><img file="JPP3222467B2_D0018.tif" /><img file="JPP3222467B2_D0019.tif" /><img file="JPP3222467B2_D0020.tif" /><img file="JPP3222467B2_D0021.tif" /><img file="JPP3222467B2_D0022.tif" /><img file="JPP3222467B2_D0023.tif" /><img file="JPP3222467B2_D0024.tif" /><img file="JPP3222467B2_D0025.tif" /><img file="JPP3222467B2_D0026.tif" /><img file="JPP3222467B2_D0027.tif" /><img file="JPP3222467B2_D0028.tif" /><img file="JPP3222467B2_D0029.tif" /><img file="JPP3222467B2_D0030.tif" /><img file="JPP3222467B2_D0031.tif" /><img file="JPP3222467B2_D0032.tif" /><img file="JPP3222467B2_D0033.tif" /><img file="JPP3222467B2_D0034.tif" /><img file="JPP3222467B2_D0035.tif" /><img file="JPP3222467B2_D0036.tif" /><img file="JPP3222467B2_D0037.tif" /><img file="JPP3222467B2_D0038.tif" /><img file="JPP3222467B2_D0039.tif" /><img file="JPP3222467B2_D0040.tif" /><img file="JPP3222467B2_D0041.tif" /><img file="JPP3222467B2_D0042.tif" /><img file="JPP3222467B2_D0043.tif" /><img file="JPP3222467B2_D0044.tif" /><img file="JPP3222467B2_D0045.tif" /><img file="JPP3222467B2_D0046.tif" /><img file="JPP3222467B2_D0047.tif" /> The examples described below are intended to illustrate the invention, not all of the invention: Implementation of the present invention Implementation of the present invention will be described with reference to the following examples. Example 1: Preparation of neutral image-forming dispersion The oil phase of the dispersion composition consists of a mixture of: Cyan Coupler A 50.0 grams Magenta Coupler B 37.1g Yellow Coupler C 65.6g Coupler Solvent D 62.6g Auxiliary solvent E 78.5 grams The aqueous phase of the dispersion consists of a mixture of: 120.0 grams of gelatin Alkanol-XC Surfactant 12.0 grams 1574.2 grams of water Total weight 2000.0 grams Procedure: 1) Combine the substances used in the oil phase and heat to 125 ° C with stirring until dissolution occurs. 2) After dissolution occurs, quickly add the hot oil phase to the aqueous phase mixture after preheating (70 ° C) with stirring. 3) The mixture is then passed through a colloid mill, collected and rapidly quenched until a dispersion is obtained. The preferred composition described above was derived from a statistically planned central complex mixture experiment. In this experiment, the ratio of the components of the oil phase was taxonomically changed at various ratios. In total, 27 different compositions were prepared and tested, including repeats of the central point. After preparing the coupler dispersions, the dispersions were mixed with additional gelatin, water and silver halide and applied in the form of a single layer on a resin coating. The sample format is as follows:<img file="JPP3222467B2_D0048.tif" /> After the application was finished, the sample was subjected to staircase exposure with a Kodak Model 1B sensitometer. More specifically, the sample was exposed to a 3000 ° K tungsten light source for 0.1 seconds via a 0-3 density step optical wedge. After exposure, the samples were processed by the standard process RA-4 color process. The process consists of 45 seconds of development, 45 seconds of bleaching-fixing, and 90 seconds of washing. Subsequently, the photographic paper sample after application was dried with hot air. Composition of RA-4 color developer Triethanolamine 12.41g / l Phorwite REU 2.30 Lithium polystyrene sulfonate (30%) 0.30 N, N-diethylhydroxylamine (85%) 5.40 Lithium sulphate 2.70 Kodak / Color Developer CD-3 5.00 DEQUEST 2010 (60%) 1.16 Potassium carbonate 21.16 Potassium bicarbonate 2.79 Potassium chloride 1.60 Potassium bromide 7.00 mg / l 1 liter with water The pH value at 80 ° F is 10.04 +/- 0.05. RA-4 Bleach-Fixer Composition Sodium thiosulfate (56.5%) 127.40g / l Sodium metabisulfite 10.00 Glacial acetic acid 10.20 EDTA ammonium ferric 110.40 1 liter with water 80 The pH value at ° F is 5.5 +/- 0.10. Post-exposure photographic paper sample processing was performed at developer and bleach-fixer temperatures adjusted to 95 ° F. Cleaning was performed with 90 ° F tap water. Neutrality test After the developed sample is dried, the density of each staircase is measured to determine which exposure staircase produced the status A density closest to 1.0. After the determination is complete, the exposure staircase has measurements of the visible absorption spectrum. Then, the spectrophotometric data is converted to colorimetric data, and the corresponding a^*, b^*, C^*And L^*Is calculated. These chromaticity coordinates are well-known chromatic methods in the CIE system (International Commission on Illumination), and their origins are detailed in many textbooks on the science of color. For example, Fred W. Billmeyer, Jr. and Max Saltzman, PRINCIPLES OF COLOR TECHNOLOGY (2nd edition), published by John Wiley and Sons in New York, and especially its 25-66 pages are of interest. Therefore, the coordinates a^*And b^*Is a measure of the color of the subject. a^*The value of is generally considered to be a measure of the degree of red or blue of the subject. a^*A subject for which is a positive value has a deeper red color, while a^*A negative value means the degree of greenness of the subject. Similarly, b^*For, a positive value means that yellow is stronger, while a negative b^*The value means an increase in blue. The brightness or darkness of the subject is the symbol L^*To measure using. 100 L^*Values indicate that the subject is completely white, and L of 0^*The value indicates that the subject is completely black. L^*A value between 0 and 100 indicates that the lightness is intermediate. This does not make much sense in a black-and-white image formation system. Because the system is a^*And b^*And because both of these symbols are near zero, meaning they are uncolored. For black-and-white photos, C^*Is also almost zero. If the subject should be reproduced neutrally, a^*And b^*Should have a very small value for. In fact, a^*And b^*The closer to zero, the less color the subject will have, and the more neutral the subject will be. In the example below, L^*Indicates the brightness of the sample piece and is independent of the color of the sample piece. In the colorimetric calculation here, the present inventors assumed a color temperature of D5500 and used a CIE1931 standard two-degree colorimeter. In the above-mentioned coating film forming example, the color measurement result for the test piece is a.^*Values are -1.15, b^*Is 1.23, and the brightness is L^*Was 38.2. a^*Value and b^*Both values were close to zero, indicating that neutrality was achieved. As a side note, the specimen was visually neutral when observed under near D5500 illumination, with no evidence of color bias. a^*, b^*, L^*And C^*The calculation of the colorimetric value of is simple and is detailed in the literature shown above. However, to further clarify this calculation, the following derivatives are given for the four terms. First, it is necessary to know the spectral distribution of the light source used for observation illumination. For these calculations, we chose a daylight source with a color temperature of 5500 Kelvin (D5500). The spectral distribution P (λ) of this light source is known, and in our case we chose to use a spectral range of 340 nm to 800 nm for an increment of 10 nm. Secondly, it is necessary to know the reflection spectrum R (λ) of the subject to be observed. These data can be appropriately obtained by using a commercially available reflective spectrophotometer. The wavelength range to be measured is 340 nm to 800 nm. Finally, it is necessary to know the CIE1931 two-degree standard colorimetric functions x (λ), y (λ) and z (λ). These values can also be conveniently obtained from the literature cited above for the entire required wavelength range. After obtaining the above values, multiply them together as a function of wavelength, and sum the respective values of x (λ), y (λ) and z (λ) to the stimulus values X, Y and Get Z. After the calculation, these stimulus values are measured using the following equation.^*, b^*, L^*And C^*Used to calculate: a^*= 500 [(X / X_n)^1/3-(Y / Y_n)^1/3] b^*= 200 [(Y / Y_n)^1/3-(Z / Z_n)^1/3] L^*= 116 (Y / Y_n)^1/3-16 C^*= (a^*2+ b^*2)^1/2 In these equations, X_n, Y_nAnd Z_nRepresents the stimulus value of the reference white object. Other methods are also useful in assessing the reproduction of tone in various photographic systems. For example, when comparing the color reproduction of subjects when reproducing colors by two different color photographic systems, the color difference is ΔE.^*It is often convenient to express as, and ΔE is defined as: ΔE^*= [(ΔL^*)²+ (Δa^*)²+ (Δb^*)²〕^1/2This equation is known as the color difference equation and was established by the CIE in 1976. As you can see by examining this equation, the L of the two subjects^*, a^*And b^*The color difference can be determined by summing the squares of the difference and calculating the square root. To mention more similar ones, we evaluated the overall tone reproduction of the black-and-white prints used to reproduce the landscape with various and harmonious colors, and the tone reproduction was a color photograph of the same original landscape. It is often desirable to compare it with that of. One method of comparing the reproduction of two types of photographs in terms of tone accuracy is to use the above-mentioned color difference formula. In order to evaluate the color difference, the first thing you need to do is take a picture of the scenery. In this case, a test scene is prepared with a neutral staircase optical wedge exposed area and other colors to harmonize, including red, green, blue, cyan, magenta, yellow and other colors. The color negative used to shoot this scene is developed and subsequently used to print the scene on comparative black and white photographic paper. The two commercially available black and white photographic papers are Kodak Polycontrast III Paper and Kodak Panalua M Paper. Polycontrast III paper is an orthomatic photosensitive photographic paper. This means that the photographic paper has spectral sensitivity in the blue and green regions of the visible spectrum. In contrast, Kodak Panalua M Paper is panchromatic photosensitive. This means that this paper is sensitive to red, green and blue light. The third black-and-white photographic paper to be subjected to the test is the photographic paper described in the section of the multilayer invention below. For comparison, the above-mentioned photographic paper and Kodak Ectacolor Supra color photographic paper are printed using a color negative including a test scene. Develop color prints using the standard Kodak RA-4 color development process. Develop Kodak Polycontrast III and Kodak Panalua M prints using the black and white processes recommended for them respectively. The color-developing black-and-white photographic paper of the present invention is developed by the same Kodak RA-4 color development process as in the case of the color print described above. After printing on each photographic paper and finishing color matching for one density of neutral patches (at a density of about 0.8), each color and neutral patch for each print was determined for it. It will have a visible absorption spectrum. These absorption spectra are then converted to their corresponding stimulus values, and therefore their colorimetric values are also stopped using the equations described above. To assess overall color reproduction errors, compare Kodak Ectacolor Supra Color Paper prints with Kodak Polycontrast III prints, Kodak Panalua M prints and the color-developed black-and-white prints from the present invention below. It can be performed. In assessing the overall error in color reproduction, ΔE for each of the 30 patches on each print.^*It is convenient to sum the values. As is clear, ΔE^*The print with the smallest total value of has the smallest color reproduction error compared to the color print. The table below shows the above-mentioned black and white prints.^*It is a summary of the cumulative values. Table 1 Print material ΔE^* Kodak Polycontrast III 755.7 Kodak Panalua M 688.3 INDUSTRIAL APPLICABILITY 633.7 ΔE listed in Table 1^*Regarding the values, some of those calculated values are a for each test patch.^*And b^*Includes relative changes in. In black and white print a^*And b^*Is expected to approach zero, so ΔE^*The value of will increase as expected. To better clarify the colors of these reproductions, the new colorimeter ΔZ^*It is easier to compare the absolute difference in brightness of each patch by comparing and defining. Where ΔZ^*Is simply the absolute value of the difference in brightness between the two test patches: ΔZ^*= | L^*₁-L^*₂| Here, if each of the prints using Kodak, Ectacolor, and Supra color prints as reference prints, each ΔZ of the test patch^*Summing the values together, as can be seen in Table 2 below, the present invention makes the overall error in brightness reproduction lower than any of the other black and white prints. Table 2 Print material ΔE^* Kodak Polycontrast III 312.6 Kodak Panalua M 182.0 Invention 107.8 The graph information of these data is shown in Fig. 1, Fig. 2 and Fig. 3. These graphs show the saturation C for each of the 30 different test patches in each test print.^*And lightness L^*The color reproduction of Kodak Polycontrast III, Kodak Panalua M and the present invention is compared with Kodak Ectacolor Supra Color Paper. Multi-layer example configuration in color photographic paper format:<img file="JPP3222467B2_D0049.tif" /> The structure of the film described above is the same as that of ordinary commercially available color photographic paper. However, in the case of the black and white photographic paper of the present invention, it is considered that the intermediate layer and the central UV absorbing layer do not preferably exist because there is no need to prevent cross-contamination between the layers of the oxidized developer. .. All three emulsions used in this multilayer element are silver bromide (99: 1). This coating was prepared on a regular film making device. After coating, exposure and treatment were performed as described above. The colorimetric data was also obtained as described above. From the results of the analysis, when the status A density is red 1.03, green 1.04 and blue 1.02, the corresponding a^*And b^*It can be seen that the values are 0.18 and 0.09, respectively. Related L^*The value is 38.5. Extremely low a^*And b^*Besides, the post-exposure patch was found to be visually neutral.<img file="JPP3222467B2_D0050.tif" /><img file="JPP3222467B2_D0051.tif" /><img file="JPP3222467B2_D0052.tif" /><img file="JPP3222467B2_D0053.tif" /><img file="JPP3222467B2_D0054.tif" /><img file="JPP3222467B2_D0055.tif" /><img file="JPP3222467B2_D0056.tif" /><img file="JPP3222467B2_D0057.tif" /><img file="JPP3222467B2_D0058.tif" /><img file="JPP3222467B2_D0059.tif" /><img file="JPP3222467B2_D0060.tif" /><img file="JPP3222467B2_D0061.tif" /><img file="JPP3222467B2_D0062.tif" /><img file="JPP3222467B2_D0063.tif" /><img file="JPP3222467B2_D0064.tif" /> The above-mentioned layer structure 1 shows the structure and composition of the photographic element referred to in Example 1. The layer structure 2 described above shows the structure of Example 2, and here all three types of spectrosensitive emulsions are contained in a single emulsion layer. This element is referred to as "panchromatically sensitized". Satisfactory black and white prints can be obtained by preparing and processing as in Example 1. Example 3-Example 7: Blend of yellow emulsions for improved exposure latitude It has been found that the amount of blue-sensitive emulsion required is compared to the amount of red-sensitive or green-sensitive emulsion in order to accurately reproduce the brightness of the subject in the elements described herein when using color negatives. It was a relatively small amount. However, since the emulsion used in these elements is a monodisperse emulsion, it has only a very narrow range of exposure latitude when treated. This defect is exaggerated when the coating amount of the emulsion is significantly reduced for reasons such as the reduced lightness referred to above. To correct for this defect, it is possible to design an emulsion with a higher dispersity and thus improve the desired exposure latitude. This polydisperse emulsion, when used in place of the monodisperse emulsion, increases the relative exposure latitude of the elements, resulting in a black-and-white print with clearer color tones where the polydisperse emulsion was exposed. Will result. Another approach for correcting this defect is to blend two or more emulsions that are also spectrosensitized but have different particle sizes or sensitivities. If we choose to develop two emulsions that are similarly sensitized but have different particle sizes, there will be differences in the sensitivity of those emulsions to light. The larger the particles, the higher the sensitivity, and the smaller the particles, the lower the sensitivity. Since these two or more emulsions have uniquely different sensitivities due to the difference in particle size of each of these emulsions, a blend of at least two such emulsions is exposed. It will result in an effective increase in latitude. An example of this technique was achieved by blending two monodisperse yellow emulsions with different particle sizes. Table 1 below summarizes the emulsion particles used to achieve this improvement in exposure latitude. Here, the relative particle selection of the emulsion is based on a technique known for estimating the relative sensitivity difference between emulsion particle sizes where the particle shapes are similar. In the example below, the calculated sensitivity difference between the first and second particles is 0.23 log exposure. This difference in sensitivity is sufficient to increase the relative exposure latitude of the elements, and is not large enough to prevent exposure due to inadequate sensitivity, and the difference in sensitivity from the first emulsion. Was judged to be large enough not to be noticeable.<img file="JPP3222467B2_D0065.tif" /> The above-mentioned elements were prepared according to the specifications and formulations shown in the multilayer element, layer structure 1 described in Example 1. The emulsion blends described above were used as Examples 3-7 instead of a single bluish emulsion. A pair of blended emulsions was applied in the same coating amount as a single emulsion. The prepared material was exposed with a color negative. The color negative used here is a pre-exposure to a large number of colored test subjects having various brightnesses. The materials of each example were then treated with a standard Kodak Ectacolor RA-4 process. The resulting prints were judged with respect to the improved exposure latitude using a skilled observer. The result of the determination indicates that the print showing the highest improvement in exposure latitude is when the blend ratio of the first and second emulsions is 0.50 to 0.50, as in example print number 3. The prints showing the lowest level of exposure latitude were Example 3 and Example 7. Overall, these observations are consistent with the assumption that the exposure latitude of the sensitizing layer can be increased by combining emulsions of different sensitivities. It is also considered that this advantage of the emulsion mixture can also be obtained when using the emulsion blend for the single layer structure of Example 2. Example 8-Example 10: Use of another yellow pigment-forming coupler for improved photostability The defect observed in the behavior of the elements described in Example 1 is that the relative regression rates (fade rates) of the three image dyes with respect to light are unbalanced. If the recession rates of the three dyes are not the same, the print will undergo undesired discoloration after prolonged exposure to light. In the first example described above, when the print is exposed to light for an extended period of time, the neutral-looking image will turn into a "bluish" image. The change in hue of the image is caused by the loss of the yellow image dye at a rate greater than the loss of the cyan or magenta image dye. We have discovered that some yellow pigment-forming couplers are less sensitive to photoregression than other couplers. The data shown in Table 2 below compare the regression of coupler C with the regression of couplers C5 and C8, two other types of yellow pigment-forming couplers. These two types of couplers were dispersed in an oil phase containing cyan coupler A and magenta coupler B in an amount equal to that of coupler C together with the coupler solvent and auxiliary solvent.<img file="JPP3222467B2_D0066.tif" />Example 11-Example 15 Other yellow couplers were compared to couplers (C) and their photostability was measured using a modified dispersion composition with stabilizer (L) removed from the oil phase. The results of these experiments are shown in Table 3 below.<img file="JPP3222467B2_D0067.tif" /> In preparing these dispersions, equimolar amounts of other yellow couplers were used instead of the coupler (C) in the color-developing dispersion. The formulation and preparation method of the dispersion used is described in Example 1. The data in Tables 2 and 3 clearly show that the photostability of the yellow component in the color dispersion can be significantly improved by optionally using these preferred couplers instead of the coupler (C). There is. The next layer structure 3 shows the coating formats prepared in each of these Examples 11 to 15.<img file="JPP3222467B2_D0068.tif" />Example 16: Use of polyester support for diversification of applications When a coating is applied on the resin-coated paper, a photographic element suitable for direct reflection observation is completed. Resin-coated papers have shown only one type of material to which the types of sensitizers described herein can be applied. A material exemplified in Example 1 having a transparent 0.18 mm polyester base as a support was prepared. This material is suitable for backlit display type observations where the display box contains a light source and a translucent diffuser. The thickness of the polyester basesheet support can be varied to meet the requirements of that particular application. Normally, the thickness of the support having this property is about 0.10 to 0.18 mm. Other transparent supports such as acetate or cellulose nitrate can also be used. Examples of other applications that require a transparent support include X-ray film, cinema film, cinema intermediate film, slide film, and others. Example 17 For some applications, print display boxes do not use a translucent diffuser over the light source. For applications such as these display boxes, a light diffusing layer is applied between the transparent photographic support of Example 16 and the sensitizing layer of the elements. The diffusion layer is composed of a mixture of gelatin and titanium dioxide particles, the thickness and concentration of which is adjusted to produce the minimum concentration without being translucent enough to expose the backlight of the display box. Example 18 A second type of support commercially available from DuPont is known as Melinex . This material is a diffusive reflective support, composed of void-forming polyester and barium sulfate particles filled therein. Sensitization was performed using the elements described in Example 1 to obtain a black-and-white print. Other types of supports include films made from polyvinyl acetate, polyvinyl chloride, polyethylene, polycarbonate, polystyrene, cellulose nitrate and others. For perfection, there are biaxially stretched and void-forming polypropylene or polyethylene supports and paper fiber supports that include materials known to act as a water vapor or oxygen barrier layer. In the case of oxygen barriers, polyvinyl alcohol is known to be very effective. Requirements for changing the color development process for the elements of Examples 16-18 When sensitizing a transparent support, it is necessary to increase the coating amount of a sensitizer such as a coupler dispersion and silver halide. Usually high enough satisfying D_maxIn order to achieve the above contrast, it is required that the coating amount of the emulsion and the dispersion is almost doubled as compared with the reflective support. For this reason, it is necessary to develop about twice as much silver halide as in the standard color development process. According to the findings of the present inventors, in the case of the standard 45-second color development process, a color developer that is insufficient to react with silver halide during development can be diffused in the element anyway. The solution to this problem is to increase the development time (and / or bleaching-fixing time) to almost twice the normal time. Through this small process change, contrast and D_maxThe density is substantially higher than in the case of standard color development time, and also. It will be judged to be suitable for observing direct transmission. Example 19: Development of photographic paper containing a very small amount of silver halide Samples of elements were prepared in which the amount of silver halide was substantially reduced. In the case of this sample, the coating amounts of red, green and blue silver halide are as shown in Table 4 below, and the amounts used in Example 1 are also shown for comparison.<img file="JPP3222467B2_D0069.tif" /> The key to a substantial reduction in silver halide coverage is the use of "developer-enhanced" baths instead of standard color developing baths. This developer-enhancing solution contains hydrogen peroxide. The presence of hydrogen peroxide allows the developed silver halide to be reused by acting as an electron transfer agent between the developed silver and the color developer, thus the developed silver. The need can be substantially reduced. The formulations used for the developer-enhancing solution are as shown in Table 5 below.<img file="JPP3222467B2_D0070.tif" /><img file="JPP3222467B2_D0071.tif" />Example 20-Example 23: Addition of antioxidant to dispersion oil phase to reduce seizure As is well known, photo regression occurs when exposed to light. The degree of this regression is proportional to the type of photographic image (silver vs. pigment vs. pigment), the intensity of light, and the wavelength of light. Depending on the photographic image, the area that does not have an image (D_maxAlso known as) also shows fading. This brown color is mainly due to yellow contamination (yellow stain). Yellow stain is known as "baking". Various additives and treatments are usually used to reduce or minimize the formation of this stain due to prolonged light exposure. Among the more effective stain inhibitors used in color photography using dye images, there is a category of antioxidants known as hydroquinone. When hydroquinone is mixed into the oil phase of the coupler dispersion, it can act as an antioxidant and significantly reduce the formation of yellow stains even after prolonged exposure to light. According to the findings of the present inventor, when such hydroquinone is mixed in the oil phase of the dispersion, the formation of burnout during exposure can be significantly reduced. Table 7 below shows the reduction in burnout obtained when the photographic element sample formed in Example 1 was exposed to 50 klux of sunlight for 2 weeks.<img file="JPP3222467B2_D0072.tif" /> In Examples 20 to 23 above, the selected hydroquinones are 1,4-benzenediol and 2-5-di-sec-dodecyl. The data shown in Table 7 clearly show how the degree of burnout formed during light exposure can be reduced when hydroquinone oxidants are mixed. It can also be added that hydroquinones other than those used in the above examples are also effective. Example 24-Example 30: Addition of hydrophobic polymer to reduce sensitivity to leuco dye formation in bleaching-fixing baths As is well known, the cyan dye formed in the color development process is sensitive to the formation of leucocyan dye if the oxidation potential of the bleach-fixing bath (Brix) is below a certain minimum threshold. It has an electrolytic reduction potential low enough to prepare the dye. Sensitivity to dye reduction is a function of the concentration of ferrous ions in Brix, the pH value of Brix, and the hydrophobicity of the dispersion in which the cyan pigment is formed. The formation of leucocian pigments is usually not a problem in the developing process if Brix is exhausted and reinforced. When replenishing Brix, the amount of ferric ions generated and developed as ferric ions to oxidize the developed silver to form silver bromide can cause significant formation of leucocyanine pigments there. Increase to quantity. The formation of this leucocyanine pigment is undesirable because it causes a noticeable reduction in the cyan contrast of the print, which adversely affects color reproduction. For example, in the case of a neutral print formed in color as described in the present specification, an image in which the color looks red can be obtained because the desired amount of cyan pigment is lacking. To reduce the susceptibility to this leucocyan dye formation, we have balanced the addition of hydrophobic polymers, such as poly-t-butylacrylamide, to the oil phase of the chromogenic dispersion. It was also found that the sensitivity of the leucocian dye was substantially reduced in this image. Table 8 below shows the composition of the dispersions used to test the present invention:<img file="JPP3222467B2_D0073.tif" /> As can be seen in Table 8, mixing the polymer poly-t-butylacrylamide into various dispersions effectively and surprisingly reduces the sensitivity of the treated coating to the formation of leucocian dyes. Be urged. Description of the procedure used to test leucocian pigments: A color-developing dispersion was prepared as described above. Where necessary, the polymer poly-t-butylacrylamide is added to the oil phase of the dispersion in the proportions shown in Table 8 above. After the dispersion was prepared, it was applied with a predetermined amount of silver halide on resin coated color photographic paper using standard coating techniques. After preparing the coating, it is exposed and processed as described above. An X-rite densitometer is used to measure and mark areas of the coating with a status A concentration of 1.0. The coating is then immersed in a ferrous sulfate reduction bath for 5 minutes. After rinsing and drying in distilled water, the concentration of the sample is measured again and the change in concentration from Dr = 1.0 is calculated by the difference from the original sample. For example, the ferrous sulfate bath described below resembles the chemistry of a depleted bleaching-fixing bath. Here, in the case of a bleach-fixing bath, the bleaching bath (ferric ion) is reduced by the developed silver to ferric ion, which is known to be a strong reducing agent. The ferrous sulfate bath used to process the sample was prepared by dissolving 41.8 g of ethylenediaminetetraacetic acid (EDTA) tetrasodium in 1.01 distilled water and then adding a 10% solution of nitric acid to adjust the pH to 4.0. Prepare. The solution is then deoxidized by bubbling nitrogen over 15 minutes. Then, 15.2 g of ferrous sulfate (7hydrate) is added with stirring. Dilute ammonium hydroxide is then added to raise the pH value of the solution to 5.0. It will be readily apparent that the present invention is not limited to the applications described above. Listed below are examples of other photographic systems that have the utility and advantages of forming silver-free black-and-white images: 1) Production of black and white movie print film. In making a black-and-white cinematic print film on an acetate or polyester base, prints can be printed from color negative products using conventional cinematic printing techniques. At present, black-and-white movie print film has not yet reached the market. This would allow the contrast to be manipulated at the printing stage rather than at the processing stage as is normally done by adjusting the ratio of the red, green and blue sensibility layers independently. .. It will also allow the color timer to create scene-scene contrast changes during the burning stage, similar to the current scene-scene color timing method. This is currently impossible. 2) Production of black-and-white movie intermediate film. This will be extremely useful in industries with unique effects and will provide greater flexibility in the production of burn-in and holdout properties. 3) Fabrication of black and white display film for backlight applications. 4) Manufacture of X-ray film in which the entire amount of silver is recovered. 5) Manufacture of masking film. 6) Making movie soundtrack film. 7) A black-and-white layer added into the ultra-low sensitivity emulsion layer of a color negative film to improve detail. 8) Using a neutral image-forming dispersion in a layer adjacent to one or more color layers, for example as described in British Patent No. 4,946,765 (P. Hahm; Eastman Kodak). Increasing the exposure latitude of color prints. These and other modifications in the present invention are within the scope of the present invention as disclosed herein. Although the invention has been described in detail with reference to particularly preferred embodiments thereof, it should be understood that various modifications and improvements may be made within the spirit and scope of the invention.