JPS6138460B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a silver halide photographic material. Silver halide photographic materials are produced by coating a variety of supports with at least one silver halide emulsion layer, an undercoat layer, an intermediate layer, an antihalation layer, an ultraviolet absorbing layer, a protective layer, a back coat layer, etc., and drying. Manufactured by Those skilled in the art should take precautions to prevent unnecessary silver from being developed during the production of silver halide emulsions and during coating and drying, or so-called fog, or, conversely, to prevent undevelopable areas from occurring in silver image areas that should be developed. paid. It has recently been discovered that silver halide photographic materials often have serious defects called "white spots" or "white spots", which are spots that cannot be developed in the silver image area to be developed. An object of the present invention is to provide a method for producing a silver halide photographic material that does not have the above-mentioned drawbacks.
The present inventors have attempted to investigate the cause of and countermeasures for this "white spot" from all angles, from the production of the silver halide emulsion to coating drying and storage of the obtained material. One of the causes was found to be the type of support used. That is, for example, JP-A-53-
As described in 19021 and 1984-46035, it is known to mix various pigments, etc. in order to improve the hue of the resin of a paper support coated with polyolefin resin. However, it has been confirmed through experiments using various supports that among these pigments, ultramarine blue and pigments with the same chemical components as ultramarine blue are responsible for the above-mentioned "white spots." However, not all silver halide photographic materials with supports containing ultramarine blue produced "white spots." In other words, it was confirmed that there are some photosensitive materials that do not generate this phenomenon. Subsequently, through extensive efforts, it was discovered that, contrary to expectations, developer substances contained in the constituent layers of silver halide photographic materials were involved in the occurrence of "white spots." Hydroquinones and 3-pyrazolidones are mixed into the photographic layer, for example, in order to process with an alkali activating solution that does not substantially contain a developer in the silver complex diffusion transfer method or stabilization treatment, or in order to process the photosensitive material with an alkali activating solution that does not substantially contain a developer. It is mixed for the purpose of accelerating development and improving storage stability. It has been found that for hydroquinones, the occurrence of "white spots" is remarkable at concentrations of 30 mg, especially 50 mg or more, and for 3-pyrazolidones, 5 mg, especially 10 mg or more per square meter. A silver halide photographic light-sensitive material using a support containing ultramarine blue and containing 20 mg/m ² of hydroquinone in the photographic layer is
No occurrence of "white spots" was observed. Moreover, even when this material was left under high temperature and high humidity conditions, such as 50°C and 80% RH, for 72 hours, "white spots" did not occur. Furthermore, it was confirmed that when transferring from diffusion transfer negative paper with "white spots" to positive paper, such "white spots" appeared as "black spots" on the positive material. The process leading to the present invention has been outlined, and after many experiments, a method for producing a silver halide photographic material that does not produce "white spots" was discovered. In particular, the present invention relates to a photograph containing a dihydroxypenzene-based developer or/and a 3-pyrazolidone developer in an amount of 30 mg/m ² or more and/or a 3-pyrazolidone developer in an amount of 5 mg/m ² or more on a support having ultramarine blue or a pigment having the same chemical components as ultramarine blue. This is basically achieved by substantially stopping the diffusion of the developer into the layer substantially immediately after the application of the coating solution. In the above, "substantially immediately after coating" means the time from when the coating solution adheres to the support until the diffusion of the developer in the photographic layer substantially stops. Therefore, the shorter the time, the better. Although it varies to some extent depending on the amount of ultramarine blue and developer, it is within about 180 seconds at most, preferably within about 120 seconds. Furthermore, "substantially stopping" means that in a photographic coating solution or in a coating layer simply adhered to a support, the developer is dissolved in molecular form and diffuses and moves three-dimensionally. The solution forms a hard photographic layer film during the cooling, setting and drying processes, but by the time a completely dry photographic layer film is formed, the layer diffusion of various photographic additives, such as developing agents and matting agents, is almost complete. There is a period of complete cessation, and this should be interpreted as almost complete cessation, and not microscopic movement or movement associated with membrane contraction that may occur afterwards. Even when the silver halide photographic material produced by the method of the present invention was left for a long period of time under the above-mentioned high temperature and high humidity conditions, no "white spots" were observed. Although not limited to inferences from the obtained developed surface, the "white spots" of the present invention may be caused by a developing material that has undergone a chemical change due to contact between the ultramarine blue and the developing material, or may have been newly formed. It is thought that this is because some kind of reactant diffuses and renders the silver halide grains inactive for development. In this sense, the present invention may be applicable to other developing agents or similar compounds. In order to substantially stop the diffusion of the developer in the layer substantially immediately after coating the photographic coating solution, for example, the concentration of the binder, preferably gelatin, in the coating solution containing the developer should be as high as possible; Although it was found that the effect of preventing white spots is small, it is necessary to reduce the amount of moisture (both moisture and solids), use a binder with low water diffusivity, and use an intermediate barrier layer (also an undercoat layer) such as gelatin on the support. A variety of measures can be taken, such as providing the developer material with a higher temperature, making the developer material as diffusion resistant as possible, increasing the conditions of the cooling set, and speeding up the drying process. The support used in the present invention is preferably an opaque support, such as a paper support coated with a polyolefin resin, baryta paper, a polypropylene film sheet as described in JP-A-49-99022, and JP-A-48-81521. Sheets such as those described in , polystyrene film sheets, etc. are used. On the other hand, the cause of the "white spots" is thought to be related to the sulfur component among the components of ultramarine, which will be described later. This is because the other components are not as photographically active. Therefore, it is considered that a support mixed with a pigment containing a sulfur component can be advantageously used in the present invention. To give an example of the coated polyolefin resin, about 0.01 to 0.5 parts by weight of these pigments can be mixed into 100 parts by weight of the polyolefin resin. For other supports, the amount of pigment for the required hue can be determined by a simple experiment using this amount as a guide. The general chemical composition of ultramarine is Sio ₂ (38-42
%), _Al2O3 (23-27%) _{, Na2O} (20-23%) and S (11-14%). Pigments with the content ratio of each component other than those mentioned above, such as the above-mentioned JP-A-54-
46035 pigment may also be used. Furthermore, as mentioned above, pigments containing sulfur components can be widely employed. In addition to the supports used in the present invention,
Contains pigments such as titanium dioxide, zinc white, kaolin, clay, calcium carbonate, lead white, zirconium oxide, antimony trioxide, titanium phosphate, fluorescent brighteners, antistatic agents, antioxidants, lubricants, etc. are also obvious to those skilled in the art. The developer substances used in the present invention include dihydroxybenzene-based developers such as hydroquinone, methylhydroquinone, chlorohydroquinone, and pyrocatechol, 1-phenyl-3-pyrazolidone, 1-(m-tolyl)-3-pyrazolidone, and 1-phenyl-3-pyrazolidone. −
Phenyl-2-acetyl-3-pyrazolidone, 1
-phenyl-4-methyl-3-pyrazolidone, 1
-phenyl-4,4-dimethyl-3-pyrazolidone, 1,5-diphenyl-3-pyrazolidone,
Examples include 3-pyrazolidones such as 1.4-dimethyl-3-pyrazolidone and 1-(P-tolyl)-5-phenyl-3-pyrazolidone. These developers include water or water-miscible organic solvents,
For example, it can be dissolved in methanol, ethanol, isopropanol, dimethylformamide, acetone, etc. and applied to a silver halide emulsion layer or other photographic layer. The amount added varies depending on the purpose of use. 30mg/m ² for dihydroxybenzene developer, especially
It ranges from 50mg/m ² or more to about 2g/m ² . For 3-pyrazolidones, the amount is 5 mg/m ² , particularly from 10 mg/m ² or more to about 1 g/m ² . Of course, it is possible to use a dihydroxybenzene developer and a 3-pyrazolidone developer in combination. In carrying out the present invention, known coating methods such as the dip method, extrusion bar method, curtain coating method, and air knife method can be employed. The photographic layer to be coated may be only the silver halide emulsion layer, or may be a plurality of the above-mentioned photographic layers, and may be coated simultaneously or separately. The amount of binder applied in the photographic layer is generally 1 to 15
g/m ² , preferably 2 to 10 g/m ² . As the hydrophilic binder, in addition to gelatin, natural or synthetic binders well known to those skilled in the art, such as gelatin derivatives, polyvinyl alcohol, polyvinylpyrrolidone, and carboxymethylcellulose, are used. Silver halide emulsions can be produced by known and commonly used methods, and silver chloride, silver bromide, silver chlorobromide, or silver halide mixed with silver iodide can be used, but the silver chloride content Silver halide containing 80 mol% or more is particularly preferred. Mercapto compounds, azaindene compounds, etc. may be added for the purpose of preventing or stabilizing fog, and optical sensitization may be performed using merocyanine, cyanine dyes, etc. A coupler may also be included. Each photographic coating solution also contains surfactants, hardeners, ultraviolet absorbers, development accelerators, PH adjusters, matting agents, antistatic agents, fluorescent brighteners, synthetic polymer latexes, and plasticizers. It may contain agents, thickeners, etc. The present invention can be applied to all light-sensitive materials that use silver halide emulsions, such as black-and-white or color light-sensitive materials, direct positive-type light-sensitive materials, and plate-making materials produced by silver complex diffusion transfer. The present invention will be described below with reference to examples, but the present invention is not limited to these examples, and the idea of the present invention can be applied in various ways. Example 1 A silver chlorobromide gelatin emulsion containing 5 mol% of silver bromide was optically sensitized with an oxacarbocyanine green sensitizer after chemical heat treatment, and a hardening agent, stabilizer, surfactant, etc. were added. It was prepared using 8% gelatin, 6% silver chlorobromide
The concentration was . This emulsion is designated as A. Furthermore, as a methanol solution of hydroquinone in emulsion A,
B to E were prepared by adding the coating amount per unit area as shown in Table 1 below. Each of the emulsions A to E was applied to corona discharge treated polyethylene laminate paper. A thin film coating was performed so that the coating amount was 1.0 g/m ² of gelatin, which was advantageous for experimental operations. At the same time as applying it to the support, it was cooled and set, and then, after the time shown in Table 1 had elapsed,
It was dried with hot air for about 30 seconds. The supports used were polyethylene laminate paper (referred to as The body (let it be Y) comes out. After cutting the resulting sample, it was uniformly exposed to light so as to obtain a density of about 0.5, processed with an ordinary black and white developer, and fixed. The results of the occurrence of "white spots" were judged based on the following criteria. ○ Does not occur at all. △ Some small white spots occur. × Many large white spots appear. The results are shown in Table 1.

[Table] From the results in Table 1, it is objectively recognized that white spots are generated due to the ultramarine blue in the support and the hydroquinone in the emulsion. It can be seen that the white spots are also affected by the setting time of the emulsion. Example 2 Example 1 was repeated except that hydroquinone in the silver halide emulsion of Example 1 was replaced with 1-phenyl-3-pyrazolidone at 3,6,12,24,48 mg/ ^m2 . No white spots were observed in any of the supports Y. Only the results for Support X are shown in Table 2.

[Table] Example 3 Polyethylene laminated paper with ultramarine blue containing 1.0 g/m ² of hydroquinone, 0.3 g/m ² of 1-phenyl-4,4-dimethyl-3-pyrazolidone and 5 g/m ² of gelatin containing carbon black. An undercoat layer was provided, and a silver halide emulsion layer containing 1.5 g/m ² of silver chloride and 1.5 g/m ² of gelatin was provided thereon. The undercoat layer and emulsion layer were coated in multiple layers using an extrusion bar. After coating and cooling the support in a few seconds, hot air was blown onto the support, and after about 45 to 60 seconds, it was almost semi-dry, and after about 3 minutes, drying was completed. On the other hand, after adjusting the drying temperature and air volume and finishing the cooling set in a few seconds, hot air is blown, and after about 5 to 6 minutes, it is almost semi-dry.
Drying was completed in about 10 minutes. After exposing the obtained sample to light, it was developed by diffusion transfer using an alkaline activating solution containing sodium thiosulfate.
A transferred silver image was produced on the positive material. In the latter case, many black silver spots appeared on the white background of the positive material, whereas in the former case, no silver spots were observed at all.

Claims (1)

[Claims] 1. On a support having a pigment containing a sulfur component, 30 milligrams or more of a dihydroxybenzene-based developer and/or 5 milligrams or more of a 3-pyrazolidone developer per square meter. 1. A method for producing a silver halide photographic light-sensitive material, which comprises substantially stopping diffusion of the developer in the layer substantially immediately after coating the photographic coating solution. 2. The manufacturing method according to claim 1, wherein the pigment containing a sulfur component is ultramarine blue or a pigment with the same chemical composition as ultramarine blue.