JPS6025774B2 - Method for manufacturing silver halide photographic materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to silver halide photographic materials, and more particularly to silver halide photographic materials with improved latent image stability.

It is generally known that latent images formed in exposed silver halide photographic materials have unstable properties and tend to deteriorate over time from flashing to development.

That is, if a silver halide photographic material is not developed immediately after exposure but is developed after a period of time, there is a phenomenon called latent image regression in which the density becomes lower than that developed immediately after exposure. Stability of the latent image is one of the important practical properties required of silver halide photographic materials, and it is desirable that the latent image formed by exposure to light does not change during storage prior to development.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for producing silver halide photographic materials which greatly reduces the tendency of latent image changes, particularly latent image regression, during storage.

The latent image regression of silver halide photographic materials increases as the storage time after exposure increases, and it tends to appear particularly quickly and greatly under high temperature conditions. There are significant differences depending on the individual properties of the emulsion.

For example, silver halide manufacturing method, silver halide composition, silver halide grain size, silver halide crystal habit, type, properties and amount of gelatin and other binders, sensitization of silver halide photographic emulsions. method, type, property, and amount of chemical sensitizer used, silver ion concentration in the emulsion, pH of the emulsion, and various other additives contained in silver halide photographic emulsions (e.g., stabilizers, fog suppressants, spectral sensitizers). agent, surfactant,
development accelerators, hardeners, couplers and their solvents, etc.)
There are significant differences due to factors such as Although the cause is not well understood, the latent image stability of silver halide photographic materials has important implications for the practical properties of the photographic material, and in particular, latent image regression may depend on the individual properties of the silver halide emulsion. We have had the unfortunate experience that when trying to obtain an emulsion with high sensitivity and low fog, the result is an emulsion with large latent image regression after exposure. Therefore, the present inventors conducted various studies in order to obtain a silver halide photographic emulsion with good latent image stability during storage. According to Hakama Kosho 46-21989, when silver halide crystals are precipitated (physically ripened) in the presence of monocarboxy-substituted phenyl mercaptan, ~
It is stated that this compound acts as a physical ripening inhibitor, resulting in a silver halide emulsion with extremely fine grains and with good latent image stability. However, by such a method, it is difficult to obtain an emulsion with high sensitivity and excellent latent image stability. This is because, as mentioned above, this compound is an extremely strong physical ripening inhibitor, and the silver halide emulsion obtained in its presence becomes fine grained, making it difficult to obtain high sensitivity. Furthermore, the above-mentioned patent clearly states that if the compound is added at a stage after physical ripening, the latent image regression phenomenon cannot be suppressed. As a result of intensive research, the present inventors have found that silver halide photographic emulsions chemically sensitized with gold compounds contain the following general formula (1) (where R is a hydrogen atom, a halogen atom, or an alkyl group). , an alkoxy group, an acyl group, or an amino group, and n is 1 or 2] at 60% per mole of silver halide.
It has been found that the latent image stability of silver halide photographic materials is greatly improved by adding 9 to 500.

[This compound is included in the compounds known in the prior art, but exhibits a remarkable latent image regression prevention effect when added to the emulsion after physical ripening, which has not been shown to have any effect in the prior art, and It is a surprising fact that it exhibits a completely different effect from monocarboxy-substituted phenyl mercaptans of other structures. That is, monocarpoxy-substituted phenyl mercaptans with other structures hardly exhibit the effect of preventing carcinogenesis.
Furthermore, the present inventors have also found that the compound exhibits a particularly remarkable effect in preventing latent regression in emulsions chemically sensitized with gold compounds, which are commonly used to obtain high-sensitivity silver halide photographic emulsions. I put it out. An object of the present invention is to provide a silver halide photographic material which retains the latent image formed on the exposed silver halide photographic material in the same state as when it was exposed and which does not cause a decrease in density when developed after storage. It is to be.

Still another object is to provide a silver halide photographic material which has high sensitivity and excellent latent image stability. Examples of the gold compound used in the present invention include chloroauric acid, potassium chloroaurate, potassium gold thiocyanate, and ammonium gold thiocyanate.

The amount of the compound represented by the general formula (1) used in the present invention is preferably 0.1 to 200, preferably 9 to 50, per mole of silver halide as the weight of the gold compound. Specific examples include, but are not limited to, the following.

These compounds were published in The Journal of Organic Chemistry. It can be produced by the method described in, for example, The Journal of Indian Chemical Society, Vol. 4, p. 295. These compounds may be added at any stage during or after completion of chemical sensitization in preparing a silver halide photographic emulsion.

These compounds contain 60 to 50 mol of silver halide.
When used in the range of 0.00 mo, the above-mentioned effect appears significantly, but when added in an amount less than 60 mo, the above-mentioned effect hardly appears or the effect is very small.
If more than 3:5000 is used, the sensitivity will drop considerably and a highly sensitive silver halide photographic material cannot be obtained. The above-mentioned effects are remarkable whether the halogenated emulsion used in the present invention is produced by an acid method, a neutral method, or an ammonia method.

The present invention relates to the properties of silver halide photographic emulsions, such as the composition of silver halide (e.g., silver bromide, silver chloride, silver chlorobromide, silver iodobromide, silver chloroiodobromide), silver halide crystals, etc. It can be performed regardless of shape, crystal habit, or size.

The emulsion according to the invention can contain various additives.

For example, when chemically sensitizing with a gold compound, other chemical sensitizers (e.g., sulfur sensitizers such as thiourea and noipo, noble metal sensitizers other than gold, and reduction sensitizers) are also used. It can be used as Also, spectral desensitizers, supersensitizers, stabilizers, antifoggants, surfactants, developers, development accelerators, hardeners, hardening accelerators, couplers, desilvering accelerators, dye extraction improvers. , a whitening agent, a thickening agent, and the like. Protective colloids for the silver halide emulsion used in the present invention include gelatin, modified gelatin, albumin, agar, gum arabic, natural products such as alginic acid, polyvinyl alcohol,
Examples include water-soluble synthetic resins such as polyvinylpyrrolidone, a copolymer of acrylamide, acrylic acid, and vinylimidazole.

The emulsions of this invention are coated onto a suitable support such as glass, cellulose acetate film, polyethylene terephthalate film, paper, baryta-coated paper, polyolefin (eg, polyethylene, polypropylene, etc.) coated paper.

These supports may be corona treated by a known method, and may also be undercoated by a known method if necessary. The effects of the present invention are noticeable even when the silver halide photographic material of the present invention is exposed not only to light but also to X-rays, Y-rays, electron beams, etc.

The silver halide photographic emulsion according to the present invention is coated with a protective layer, an intermediate layer, an ultraviolet absorbing layer, an undercoat layer or other silver halide emulsions, if necessary. The silver halide photographic materials to which the present invention can be applied include black and white photographic materials, color photographic materials, general use, printing use, X-ray film use, electron microscope film use, etc., and are not particularly limited in type or use. A feature of the present invention is that a silver halide photographic material with improved latent image stability can be obtained. Examples will be described below to further specifically explain the present invention, but the present invention also includes
It is not limited to this.

Example 1 An emulsion was prepared according to the following formulation.

・Pseudochin 60 evenings ·evening 400' .

(Silver acid .Miyoshi 8-potassium polybromide
85 tm Potassium iodide
1.2 28% ammonia water
100' water 900
Scream W Maintain acetic acid 1 solution at 40qo, add solution 2 while stirring vigorously, add solution m after 1 minute, age for 9 minutes at 40:00, add solution W, and set pH = 3.0. .

A sodium sulfate aqueous solution was added to this to precipitate it, which was washed with water. This raw emulsion had an average grain size of 0.454, a mainly cubic crystal habit, and was a silver chloroiodobromide emulsion containing 95 mol % or more of bromide. After redissolving this raw emulsion and adjusting the pH to 6.0 by adding gelatin, the emulsion was divided into two halves, and sodium thiosulfate was added to each mol of silver halide to the emulsion foot. In the emulsion field, sodium thiosulfate and 20% sodium thiosulfate per mole of silver halide were added. 10:9 of chloroauric acid was added per mole of silver germide, and chemical ripening was carried out at 60 qC for 60 minutes. After ripening, 1-phenyl-5-mercaptotetrazole was added at 20% per mole of silver halide.
After adding and dividing 0 to 9, the compound {1} of general formula [1] was added in varying amounts. A hardener and a surfactant were added to these emulsions, which were coated on a polyethylene terephthalate film provided with a subbing layer and dried. The amount of silver coated was 2.4 evenings/day. After cutting each of the samples thus prepared into appropriate sizes and exposing them through a wedge with a density difference of 0.15, one of the samples was developed immediately, and the other one was
After storage at 0.80% RH for 4 days, it was developed.

Development was carried out at 20qC for 2 minutes using a developer having the following composition. Water (approximately 30°C) 500 methane 3.1 hydroquinone 12 t anhydrous sodium sulfite 45 t anhydrous sodium carbonate 67.5 potassium polybromide
Add 1.9 t water
3000 skin After this, it was stopped, fixed, washed with water, and then dried. Sensitivity (relative value) obtained as a result of concentration measurement
As shown in Table 1, the degree of latent image regression can be determined by comparing the sensitivity when developed immediately after exposure and the sensitivity when developed after being stored at 38080% RH for 4 days after exposure. . Table 1 As is clear from Table 1, the compound of the formula [1] was added to an emulsion chemically sensitized with a gold compound at a concentration of 6% per mole of silver halide.
The emulsions containing 0 c to 5000 c had the least amount of latent image regression, and the method of the present invention had an extremely excellent latent image regression prevention effect.

Example 2 An emulsion was prepared according to the following formulation.

V ``Vertical sea bream song aqueous solution Another 20 Z L Li Lian shoji poison Added to the air-resistant grains [Kankei chicks'' Potassium bromide 92.8 Ta skin Potassium iodide 3.3 Evening wind 6 N sulfuric acid Keeping the V solution at 6000, add the solution and W solution at the same time for 8M minutes while shaking strongly, and the PAg during this time
was controlled to 7.4.

After that, the side liquid was added to adjust the pH to 3.5 to precipitate the mixture, and the mixture was washed with water. This raw emulsion is a silver iodobromide emulsion containing 97.5 mol% of bromide, and has an average grain size of 0.25 mm, and is cubic in which 95% by weight or more of grains are contained within ±20% of the average grain size. It is a monodisperse emulsion. This raw emulsion was redissolved and gelatin was added to adjust the pH to 6.5, and then sodium thiosulfate at a concentration of 40:9 per mole of silver halide and ammonium gold thiocyanate at a concentration of 15:9 per mole of silver halide were added. Chemical ripening was carried out for 55 o 60 minutes. After ripening, 1-phenyl-5-mercaptotetrazole was added in an amount of 300 m9 per mole of silver halide, and then 9 of 300 m9 of exemplified compounds of general formula [1] were added per mole of silver halide in portions as shown in Table 2 below. did. Thiosalicylic acid 300% was added as a comparative compound. A hardener and a surfactant were added to these emulsions, and a subbing layer was applied to a polyethylene laminated paper and dried. The amount of silver coated was 2.0 ta'. Example 1 Each sample prepared in this way
It was processed by the same machine. Sensitivity obtained as a result of reflection density measurement (
relative values) are shown in Table 2. As is clear from Table 2, the degree of latent image regression is much smaller in 2 to 8 than in 1, and it can be seen that the method of the present invention has an extremely excellent effect of preventing latent image regression.

Claims (1)

[Scope of Claims] 1. A halogen compound characterized in that 60 mg to 5000 mg of a compound represented by the following general formula (I) is added per mole of silver halide to a silver halide photographic emulsion chemically sensitized with a gold compound. A method for producing silver oxide photographic materials. General formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. are available▼ [In the formula, R represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an acyl group, or an amino group, and n represents 1 or 2. ]