JPS6232778B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a photofog exposure method in which a direct positive silver halide color photosensitive material photographed under a xenon light source is subjected to photofog exposure and color development processing to form a positive image. In the image forming method using a direct positive color photosensitive material, a positive color image is obtained by carrying out color development after or while performing a fogging treatment on the photographed photosensitive material. Conventionally known methods for providing this fogging treatment include a so-called optical fogging method in which the entire surface of the photosensitive layer is exposed to light, and a chemical fogging method in which a chemical such as a fogging agent is used. Among these methods, the chemical fogging method has severe conditions in that the fogging agent is effective at a high pH of 12 or higher, so deterioration of the fogging agent is likely to occur due to air oxidation, which significantly reduces the fogging effect. However, the optical fogging method does not require the above-mentioned severe conditions and is more convenient in practice. However, since the optical fog method is based on the formation of fog nuclei through photodecomposition of silver halide, its appropriate conditions vary depending on the type and characteristics of the silver halide used, photographing conditions, etc. . The relationship between these various factors and appropriate fog exposure conditions is not clear, and known techniques for optical fog exposure methods include, for example, Japanese Patent Publication No. 45-12709.
No. 2, etc., merely describe a method of uniformly exposing the entire surface with low-intensity light. Conventionally, when exposing photosensitive materials, sunlight was used as a light source, but in recent years xenon light sources have been used as light sources because their color temperature is relatively close to that of sunlight and their luminous properties are instantly stable, and they are also easier to carry and handle. Xenon flash has become commonly used due to its ease of use. Note that xenon light sources refer to ordinary xenon gas-filled discharge type and lighting type lamps.
There are two types of discharge methods: electrode discharge type and electrodeless discharge type.
Lighting methods include direct current, alternating current, continuous lighting, and flash light sources. Therefore, the balanced color temperature of a color photosensitive material photographed under a xenon light source is designed to match the color temperature of the xenon light source. From the viewpoint of color reproduction, it is considered preferable to use the same xenon light source used during photography as a light source for light fogging of direct positive color photosensitive materials designed to be photographed under this xenon light source, but It is not suitable as a source. This is because, due to the characteristics of direct positive silver halide photosensitive materials, if short exposure such as flash exposure is applied at the time of light fogging, high illuminance failure will occur and a desirable positive image cannot be obtained. When used as a light source, it is disadvantageous from a practical point of view, as it generates a large amount of heat when turned on, requiring a cooling device. In addition, from the point of view of color reproducibility, it is advantageous to use incandescent light bulbs such as photographic light bulbs with various filters such as color temperature conversion filters, but this is not satisfactory from the point of view of the lifespan of the light source. Although discharge lamps such as tin halide lamps are also advantageous in terms of color reproducibility, they are not satisfactory in terms of compactness and cost. Although it is advantageous to use a fluorescent lamp as a light source in terms of compactness, longevity, and low cost,
When a normal white fluorescent lamp or a warm white fluorescent lamp is used, satisfactory color reproduction cannot be expected because the light source itself lacks blue (400 to 500 nm) and red (600 to 700 nm) components. Further, direct fog exposure of a positive color light-sensitive material is usually carried out by impregnating the material with a solution (fogging liquid) containing a compound that promotes light fog, such as a developing agent, after photographing. Therefore, the light that has passed through the fogging liquid only becomes effective when it hits the silver halide grains in the photosensitive material, so the fogging liquid becomes colored due to fatigue of the fogging liquid and air oxidation, which reduces the amount of light that hits the surface of the photosensitive material. The spectral energy distribution tends to fluctuate, and as a result, it is not always possible to obtain images with good color reproducibility. For the reasons described above, a light source for optical fogging with good color reproducibility is desired. Therefore, as a result of various studies in view of the above points, the present invention has been developed by applying light fog exposure to a direct positive silver halide color photosensitive material photographed under a xenon light source using a fluorescent lamp with high color rendering properties, thereby stably We have invented a method to obtain images with good color reproduction using a compact and long-life light source. In the present invention, a fluorescent lamp with high color rendering properties means one having an average color rendering index Rα77 or more. The average color rendering index is a scale that shows the degree of color shift when a specified test color is illuminated with a sample light source, with the highest value being 100 and 50 for warm white fluorescent lamps. Some fluorescent lamps having an average color rendering index Rα of 77 or more have spectral energy distributions as shown in FIGS. 1 to 7. Adjustment of the optical fog illuminance can be done by changing the luminous intensity of the light source, by using a filter such as a neutral density filter under a constant light source, or by using the distance between the photosensitive material and the light source, and the angle between the photosensitive material and the light source. This can be done to advantage. Further, the present invention can be advantageously implemented by combining two or more types of light sources with different spectral distributions and color temperatures. Light conditions for photofogging vary depending on the photosensitive material used, but light of 0.01 to 2000 lux can be used. In the present invention, the light fog exposure may be performed before color development, that is, after photographing, in a processing bath where the entire surface is exposed prior to development, or may be performed while color development is being performed. In the former case, reducing substances, if necessary, are added to the treatment bath.
It can contain an alkali agent, an inhibitor, and a desensitizer. In the latter case, it is preferable to carry out the exposure at the beginning of the development because the development time can be shortened, and in this case, it is advantageous to start the exposure after the developer has sufficiently penetrated the emulsion layer. The color developer is substantially free of silver halide solvent, and the developer used in the developer is a conventional color developer. The processing temperature of the color developing solution is preferably 20°C to 70°C, preferably 30°C to 45°C. In the silver halide emulsion used in the direct positive silver halide color light-sensitive material of the present invention, the grain surface is not fogged in advance, and a latent image is mainly formed inside the silver halide grain, and most of the light-sensitive nuclei are An emulsion having silver halide grains inside the grains, which include any silver halide, such as silver bromide, silver chloride, silver chlorobromide, silver iodobromide, silver chloroiodobromide, etc. . This color photosensitive material includes a red-sensitive emulsion layer for forming cyan, magenta and yellow dye images;
It has a green-sensitive emulsion layer and a blue-sensitive emulsion layer, and commonly used couplers can be used as couplers. Further, the emulsion may contain known carbocyanine dyes, merocyanine dyes, etc. as optical sensitizers for emulsions, and may also contain conventional photographic additives such as fog suppressants, stabilizers, anti-staining agents, etc. And color photosensitive materials are
It is possible to provide a large number of various photographic constituent layers such as an emulsion layer, a filter layer, an intermediate layer, a protective layer, a subbing layer, a backing layer, and an antihalation layer on the support. Further, the photofog exposure method of the present invention provides a direct positive color photosensitive material in which the coupler and the color developing agent or the color developing agent precursor are protected from contact during unexposed exposure and are present in the same layer, so that they can come into contact with each other after exposure. Alternatively, when a color developing agent or a color developing agent precursor is contained in a coupler-free layer of a positive color light-sensitive material and an alkaline processing solution is permeated, the color developing agent or color developing agent precursor undergoes alkaline hydrolysis. It can also be applied to color photosensitive materials in which objects can be moved and come into contact with the coupler. The present invention will be explained in detail with reference to Examples below.
The present invention is not limited to these. Example 1 (1) Preparation of sample A direct positive silver halide color light-sensitive material serving as a sample in this example was prepared by sequentially coating the following layers on a resin-treated paper support from the support side. Layer 1: Cyan-forming red-sensitive silver halide emulsion layer An internal latent image type silver chloroiodobromide emulsion was prepared by a convergence method according to the method described in Example 1 of US Pat. No. 2,592,250. did. Cyan coupler 2,4-dichloro-3-methyl-6-[α-(2,4-di-tert-amylphenoxy)butyramide]phenol 80 g, 2.
2 g of 5-di-tert-octylhydroquinone,
100g dibutyl phthalate, 200g paraffin,
Mix and dissolve 50g of ethyl acetate, add to gelatin solution containing sodium dodecylbenzenesulfonate, and use the dispersed solution as a pigment. and The amount of silver is added to the emulsion spectrally sensitized by
The amount of coupler was 400 mg/m ² and the coupler was 320 mg/m ² . Layer 2: Intermediate layer 100 ml of a 2.5% gelatin solution containing 5 g of gray colloidal silver and 10 g of 2,5-di-tert-octylhydroquinone dispersed in dibutyl phthalate was applied to give a colloidal silver amount of 400 mg/ ^m2. . Layer 3: Magenta-forming green-sensitive silver halide emulsion layer Magenta coupler 1-(2,4,6-trichlorophenyl)-3-(2-chloro-5-octadecylsuccinimideanilino)-5-pyrazolone 100 g; 2-5-di-tert-octylhydroquinone 5g, Sumilizer MDP (manufactured by Sumitomo Chemical Co., Ltd.) 50g, paraffin 200g,
Mix and dissolve 100 g of dibutyl phthalate and 50 g of ethyl acetate, add to the gelatin solution containing sodium dodecylbenzenesulfonate, and prepare the dispersed solution in the same manner as layer 1 to prepare the pigment. and It was added to the internal latent image type silver chloroiodobromide emulsion which had been spectrally sensitized by the method described above, and coated so that the amount of silver was 400 mg/m ² and the amount of coupler was 400 mg/m ² . Layer 4...Yellow filter layer A 2.5% gelatin solution containing 5 g of yellow colloidal silver and 5 g of 2,5-di-tert-octylhydroquinone dispersed in dibutyl phthalate is applied so that the colloidal silver is 200 mg/ ^m2. did. Layer 5...Yellow-forming blue-sensitive silver halide emulsion layer Yellow coupler α-[4-(1-benzyl-
2-phenyl-3,5-dioxo-1,2,4
-triazolidinyl)]-α-piparyl-2-chloro-5-[γ-(2,4-di-tert-amylphenoxy)butyramide]acetanilide 120
g, 2,5-di-tert-octylhydroquinone 3.5 g, paraffin 200 g, Tinuvin (manufactured by Ciba Geigy) 100 g, dibutyl phthalate
Mix and dissolve 100 g of ethyl acetate and 70 ml of ethyl acetate, add gelatin solution containing sodium dodecylbenzenesulfonate to disperse, and add to the internal latent image type silver chloroiodobromide emulsion prepared above in the same manner as layer 1 to obtain a silver amount of 400.
mg/m ² , and the amount of coupler was 400 mg/m ² . Layer 6... Protective layer Coated so that the amount of gelatin was 200 mg/m ² . In addition, 4-hydroxy-6-methyl-1.3.
It contained 3a.7-tetracindene.
Further, layer 1, layer 2, layer 3, layer 5, and layer 6 contained bis(vinylsulfonylmethyl)ether as a hardening agent and saponin as a coating aid. (2) Photographing method The sample in (1) was divided into six equal parts, and each was photographed as a gray chart using a xenon flash lamp FS-7000R manufactured by Ushio Inc. as the photographing light source. (3) Processing conditions The samples photographed under (2) were processed under the following conditions. Color development (2 minutes 30 seconds, light fog exposure was carried out for 10 seconds after immersion in the developer) - Bleach fixing (1 minute 30 seconds)
- Washing with water (1 minute 30 seconds) - Stabilization (45 seconds) - Rinse (3 minutes)
The processing temperature was 38°C in each step, and the composition of each processing solution was as shown below. Color developer composition: Consists of an aqueous solution of chemicals with the following types and concentrations (g/). Potassium carbonate 28.9 Potassium sulfite 2.6 Sodium bromide 0.26 Benzyl alcohol 12.8 Ethylene glycol 3.4 Hydroxylamine sulfate 2.6 Diaminopropanol tetraacetic acid 0.09 Sodium chloride 3.2 Nitrilotriacetic acid 0.4 3-Methyl-4-amino-N-ethyl-N-
(β-methanesulfonamidoethyl)-aniline sulfate 4.25 PH (adjusted with potassium hydroxide) 10.20 Bleach-fix composition Composed of an aqueous solution of chemicals of the following types and concentrations (g/). Ammonium thiosulfate 110 Sodium hydrogen sulfite 10 Iron ammonium ethylenediaminetetraacetate 60 Diammonium ethylenediaminetetraacetate 5 Bisthiourea 2 PH (adjusted with aqueous ammonia) 6.5 Stable liquid composition Glacial acetic acid 20 Sodium acetate anhydride 5 (4) Photofog exposure conditions (2) The six samples photographed in (3) were exposed to light fog using a fluorescent lamp having a color rendering index (Rα) of A to F below during color development. The illuminance of these fluorescent lamps was lowered uniformly to 1 lux on the photosensitive surface of the sample using a neutral density filter and an acrylic light diffusion plate. Light fog exposure was carried out for 10 seconds by immersing the sample in the developer for 10 seconds, taking it out of the developer and positioning it horizontally so that the light hit the photosensitive surface vertically, and then immersing it in the developer again after exposure. Fluorescent lamps A and B used in this example are for comparison with the fluorescent lamp used in the present invention.
A is Rα=59 shown in FIG. 8, B is Rα=65 shown in FIG. 9, C to F are included in the present invention, C is Rα=77 shown in FIG. 1, and D is Rα=77 shown in FIG. 5
Rα=79 shown in the figure, E is Rα84 shown in FIG. 6,
F is Rα=98 as shown in FIG. (5) Results When the gray reflection density of the treated sample was measured, as shown in Table 1, C
Good gray reproduction was obtained in fog exposure using fluorescent lamps A to F, but yellow and cyan densities were insufficient when using fluorescent lamps A and B. Table 1 shows the density of the photographed gray chaat.
It represents the yellow (Y), magenta (M), and cyan (C) densities of samples obtained by processing corresponding to point 1.5.

[Table] Example 2 The same process as in Example 1 was repeated by repeating a cycle in which each fluorescent lamp was turned on for 3 hours and turned off for 10 minutes, and when a total of 5000 hours had elapsed, the same treatment as in Example 1 was carried out. obtained almost the same result. Example 3 A sample of a gray chart photographed in the same manner as in Example 1 was subjected to photofog exposure in the photofogged state described in Example 1, with the developer reaching up to 5 cm above the photosensitive surface of the sample. The other treatments were the same as in Example 1. Table 2 shows the difference in the Y, M, and C concentrations of the sample obtained by the treatment, which corresponds to the gray chert concentration of 1.5, from those of Example 1. As is clear from Table 2, the filter effect on the blue light of the developer was also
was found to be more effective than A and B.

[Table] As described above, the present invention performs optical fog exposure using a fluorescent lamp with high color rendering properties, so images with stable color reproducibility can be obtained using a compact, long-life, and inexpensive light source. be able to.

[Brief explanation of the drawing]

Figures 1 to 7 are spectral energy distribution diagrams showing examples of fluorescent lamps with high color rendering properties used in the present invention, and Figures 8 and 9 are diagrams showing fluorescent lamps used in embodiments of the present invention. FIG. 2 is a spectral energy distribution diagram of a fluorescent lamp used for comparison with a fluorescent lamp.

Claims (1)

[Claims] 1. In a method in which a direct positive silver halide color photosensitive material photographed under a xenon light source is subjected to photofog exposure and color development processing is performed to form a positive image, the photofog exposure is performed using a fluorescent lamp with high color rendering properties. An optical fog exposure method for direct positive color photography characterized by: