JPH07113738B2 - Improved silver halide photographic light-sensitive material with less fog over time - Google Patents

Description

The present invention relates to a silver halide photographic light-sensitive material, and more specifically, to reduce an increase in fog of the light-sensitive material over time,
The present invention also relates to a silver halide photographic light-sensitive material which has reduced sensitivity failure during exposure to low illuminance and has improved graininess.

[Background of the Invention]

Many proposals have heretofore been made to prevent deterioration of photographic performance over time, including black and white photosensitive materials and color photosensitive materials. For example, it has been known to add an antifoggant, a stabilizer, or the like to a silver halide emulsion with respect to the generation of undesirable fog due to the influence of temperature and humidity over time. Commonly known compounds include 1-phenyl-described in U.S. Pat.Nos. 2,403,927 and 3,804,633, Japanese Patent Publication No. 39-2825, and the like.
There is a technique of adding 5-mercaptotetrazole or 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene.

However, these compounds have a drawback that they are insufficient in suppressing fogging with time to some extent, or that they are significantly desensitized when added to a silver halide emulsion in an amount sufficient to prevent fogging.

On the other hand, the development of high-sensitivity light-sensitive materials has greatly expanded the technology in the field of photography, contrary to photography with high-speed shutters,
Shooting technology using low-speed shutters is also used for astronomical photography and shooting at theaters and museums where flash photography cannot be used.

The photographic performance which becomes a problem in such a case is reciprocity failure characteristics, and not only high illumination failure characteristics but also low illumination failure characteristics must be good. That is, conventional light-sensitive materials do not always have good low-illumination failure characteristics. For example, even if a certain aperture value is set when taking astronomical photographs, the sensitivity is not sufficient for the brightness, and calculation is required to obtain an appropriate exposure amount. More than twice the value,
In some cases, it took more than four times as long.
Although there have been many proposals for improvement in sensitivity reduction and gradation variation as reciprocity law failure characteristics, it is still insufficient in view of the technical progress in each of the above fields.

[Object of the Invention]

An object of the present invention is to provide a high-sensitivity light-sensitive material having improved storage stability with little increase in fog during storage, and to provide a light-sensitive material having improved low-illuminance sensitivity failure and good graininess. To do.

[Structure of Invention]

As a result of intensive studies, the inventors of the present invention have found that a silver halide emulsion containing pAg of 6.5 to 8.4 and chemically ripened in the presence of a sensitizing dye and thiocyanate which is a silver halide solvent is used. It has been found that the above-mentioned objects can be achieved by a silver halide photographic light-sensitive material characterized by having at least one layer.

The present invention is based on the following findings found by the present inventors. That is, it is well known by those skilled in the art that how much pAg is set when chemically ripening an emulsion has a sufficient effect on how the chemical ripening is performed, and a sensitizing method of ripening at about pAg 4 to 5 is used. Has been known since ancient times. However, if pAg is simply set low and chemical ripening is performed, chemical ripening will be completed in a short time, but instability of fog, for example, increase in fog due to storage over time,
Or there may be a problem in reproducibility when the same chemical aging is applied. If an antifoggant or the like is used together as a countermeasure, another problem occurs as described above, and it is not a drastic solution.

However, as a result of various investigations by the present inventors, pAg
When the chemical ripening is carried out in the presence of a sensitizing dye and a thiocyanate which is a silver halide solvent, the pA
It was found that the relationship between fog and sensitivity is better, the stability of fog is improved, low-light sensitivity failure is reduced, and the graininess is improved in comparison with the case of chemically aging with g. The present invention has been reached, and such a result was unexpected for the inventor of the present invention.

The present invention will be described in more detail below.

In the present invention, at least one photosensitive layer containing a silver halide emulsion having a pAg of 6.5 to 8.4 and chemically ripened in the presence of a sensitizing dye and thiocyanate which is a silver halide solvent is provided. To obtain the silver halide photographic light-sensitive material of the present invention.

The pAg during the chemical ripening is preferably at least 1/3 of the chemical ripening time in the presence of both the chemical sensitizer and the sensitizing dye is 8.5 or less, and particularly at least 2 in the first half of the chemical ripening time. It is preferable that / 3 is 8.5 or less.

In the present invention, chemical ripening refers to sensitizing silver halide grains with a chemical sensitizer when forming a silver halide emulsion.

In the present invention, chemical ripening can be achieved by any chemical sensitizing means, and the chemical sensitizer used is not particularly limited.

Chemical sensitizers that can be advantageously used in the present invention include noble metal sensitizers, sulfur sensitizers, selenium sensitizers and reduction sensitizers.

As the noble metal sensitizer, gold compounds and compounds such as ruthenium, rhodium, palladium, iridium and platinum can be used.

When a gold compound is used, ammonium thiocyanate and sodium thiocyanate can be used together.

As the sulfur sensitizer, in addition to active gelatin, sulfur compounds such as sodium thiosulfate, thiourea and allyl isothiocyanate can be used.

As the selenium sensitizer, active and inactive selenium compounds can be used.

Reduction sensitizers include monovalent tin salts, polyamines, bisalkylaminosulfides, silane compounds, iminoaminomethanesulfinic acid, hydrazinium salts, and hydrazine derivatives.

A combination of a noble metal sensitizer and a sulfur sensitizer is preferable as the chemical sensitizer capable of more fully exerting the objects and effects of the present invention.

The amount of the chemical sensitizer added during the chemical ripening of the silver halide emulsion according to the present invention depends on the silver halide grains used.
It can be set appropriately.

In the light-sensitive material of the present invention, at least one light-sensitive layer contains a silver halide emulsion obtained by chemically ripening the emulsion with pAg of 6.5 to 8.4.

In the present invention, the pAg of the emulsion to be chemically ripened is adjusted to the above value by controlling the removal rate when removing unnecessary soluble salts after the growth of silver halide grains in the emulsion is completed. , Or silver ion or halide ion is added to set the desired pAg value.

The pAg subjected to chemical aging is 6.5 to 8.4, and a more preferable value is in the range of pAg 7.1 to 8.2.

In the present invention, the chemical ripening of the emulsion is carried out in the presence of a sensitizing dye.

The sensitizing dye according to the present invention is not particularly limited, and for example, a cyanine dye such as a zeromethine dye, a monomethine dye, a dimethine dye, a trimethine dye or a merocyanine dye can be used alone or in combination, and can be selected according to the purpose. it can.

The position of addition of the sensitizing dye according to the present invention to the silver halide emulsion may be during chemical ripening, but the specific pattern of conditions for addition, etc. is pAg adjustment-sensitizing dye-chemical sensitization. Agent pAg adjustment-Chemical sensitizer-Sensitizing dye Sensitizing dye-pAg adjustment-Chemical sensitizer Sensitizing dye-Chemical sensitizer-pAg adjustment Chemical sensitizer-Sensitizing dye-pAg adjustment Chemical sensitizer- It is also possible to add the pAg adjustment-sensitizing dye and the above-mentioned two adjacent substances at the same time. Here, the pAg adjustment includes the addition adjustment by silver ion or halide ion in addition to the desalting degree control after the completion of grain growth. Preferably, in the case of, and in the case of, it is preferable to add the sensitizing dye within 15 minutes after addition of the chemical sensitizer.

More preferably,

To add the sensitizing dye to the silver halide emulsion, it can be added after being dissolved in water or an organic solvent such as methanol or ethanol which is optionally miscible with water, and can be used alone or in a mixture of 2 You may use it in combination of 2 or more types.

In the present invention, the addition amount of the sensitizing dye varies depending on the grain size, crystal habit, etc. of the silver halide emulsion to be used, and the optimum addition amount of the sensitizing dye is determined by a method commonly used by those skilled in the art. However, it is usually preferably 20 to 750 mg, and more preferably 50 to 450 mg per mol of silver halide.

Typical examples of sensitizing dyes that can be used in the present invention are shown below, but the compounds that can be used in the present invention are not limited to these.

[Sensitizing dye]

In the present invention, chemical ripening is carried out in the presence of thiocyanate which is a silver halide solvent.

Examples of the cyanogen acid salt which is a silver halide solvent preferably used in the present invention include HN ₄ SCN and KSCN.

The amount of thiocyanate present as a silver halide solvent during the chemical ripening of the silver halide emulsion is from 0.0005 to
It is preferably 1.0 g, more preferably 0.001 to
It is 0.5 g, and particularly preferably 0.005 to 0.2 g.

In the production method of the present invention, the chemical aging temperature is 90 ° to
It is preferably 20 ° C, more preferably 80 ° C to 30 ° C.
C., particularly preferably 70 to 35.degree.

Examples of the silver halide in the silver halide emulsion according to the present invention include ordinary silver halides such as silver bromide, silver iodobromide, silver iodochloride, silver chlorobromide, silver chloroiodobromide and silver chloride. Although any of those used in emulsions can be used, silver iodobromide is particularly preferable.

The silver halide grains used in the silver halide emulsion may be those obtained by any of the acidic method, the neutral method and the ammonia method. The grains may be grown at one time, or may be grown after forming seed grains. The method of forming seed particles and the method of growing seed particles may be the same or different.

When preparing the silver halide emulsion, the halide ion and the silver ion may be mixed at the same time, or the other may be mixed in the solution containing either one. Alternatively, it may be produced by successively adding silver halide ions and silver ions at the same time while controlling the pH and pAg in the mixing vessel while considering the critical growth rate of silver halide crystals. By this method, silver halide grains having a regular crystal form and a substantially uniform grain size can be obtained. The conversion may be used at any step in the formation of the silver halide to change the halogen composition of the grains.

A known silver halide solvent such as ammonia, thioether or thiourea can be present during the growth of silver halide grains.

The silver halide grains are cadmium salt, zinc salt, lead salt, thallium salt, iridium salt (including complex salt), rhodium salt (including complex salt) and iron salt (in the process of forming and / or growing the grain). It is possible to add a metal ion by using at least one selected from the group consisting of complex salts) to make these metal elements contained inside the particle and / or on the surface of the particle.

The silver halide grain may have a uniform silver halide composition distribution within the grain, but more preferably, a core / silver halide composition having a different silver halide composition between the inside of the grain and the surface layer is used.
It is preferably shell particles.

The silver halide grain may be a grain in which a latent image is mainly formed on the surface, or may be a grain in which a latent image is mainly formed inside the grain.

The silver halide grain may have a regular crystal form such as a cube, an octahedron or a tetradecahedron, or may have an irregular crystal form such as a sphere or a plate. In these grains, any ratio of {100} plane to {111} plane can be used. Further, it may have a composite form of these crystal forms, and particles of various crystal forms may be mixed.

The size of silver halide grains in the emulsion used in the present invention is
The average grain size is preferably 0.05 to 3.0 µ, but it is more preferable to use an emulsion containing grains of 0.15 to 2.2 µ.

Regarding the grain size distribution of the silver halide emulsion, any grain size distribution may be used.
An emulsion having a wide grain size distribution (referred to as a polydisperse emulsion) may be used, or an emulsion having a narrow grain size distribution (referred to as a monodisperse emulsion. The monodisperse emulsion referred to here is the standard deviation of the grain size distribution. When divided by the average grain size, the value is 0.20 or less, where the grain size is the diameter in the case of spherical silver halide and the projected image in the case of grains other than spherical. The diameter when converted to a circular image of the same area is shown). However, it is more preferable to use a monodisperse emulsion.

An antifoggant, a stabilizer and the like can be added to the silver halide emulsion. It is advantageous to use gelatin as the binder of the emulsion.

The emulsion layer and other hydrophilic colloid layers may be hardened and may contain a dispersion (latex) of a plastic, water-insoluble or sparingly soluble synthetic polymer.

The silver halide emulsion according to the present invention can be used in color photographic light-sensitive materials, X-ray light-sensitive materials and the like.

When the light-sensitive material of the present invention is embodied as a color photographic light-sensitive material, a coupler is used in its emulsion layer.

Further, a color coupler having a color-correcting curing agent, a accelerating agent, a bleaching accelerator, a developer, a silver halide solvent, a toning agent, a hardener which accelerates development by coupling with a colored coupler, a competing coupler and an oxidized product of a developing agent. Compounds that release photographically useful fragments such as film agents, antifoggants, antifoggants, chemosensitizers, spectral sensitizers, and desensitizers can be used.

In carrying out the present invention, the light-sensitive material includes a filter layer,
An auxiliary layer such as an antihalation layer or an irradiation prevention layer can be provided. In these layers and / or in the emulsion layers, dyes which are bleached or bleached from the light-sensitive material during the development processing may be contained.

Further, a formalin scavenger, a fluorescent whitening agent, a matting agent, a lubricant, an image stabilizer, a surfactant, an antifoggant, a development accelerator, a development retarder or a bleaching accelerator can be added to the light-sensitive material.

As the support, paper laminated with polyethylene or the like,
Polyethylene terephthalate film, baryta paper, cellulose triacetate and the like can be used.

In order to obtain an image using the light-sensitive material of the present invention, a generally known color or black and white photographic process may be carried out after exposure.

〔Example〕

Specific examples of the present invention will be described below, but embodiments of the present invention are not limited to these.

Example-1 First, a silver iodobromide emulsion containing 3.0 mol% of silver iodide was prepared by a forward ammonia method forward mixing. After the grain growth was completed, it was divided into two parts, and the desalting degree was controlled respectively, and the pAg 9.0 emulsion E-
Emulsion E-1B of 1A and pAg8.0 was prepared. These emulsions were polydisperse emulsions having an average grain size of 0.70 μm.

Next, while maintaining pAg = 11.0 and pH = 9.0 at 45 ° C., a 3.0N ammoniacal silver nitrate solvent and a solution containing potassium bromide and 3.0 mol% potassium iodide were added to the gelatin solution by the double jet method. The addition rate was gradually increased as the particles grew.

After the particle growth is completed, it is divided into two parts and the desalination degree is controlled.
Emulsion E-2A of pAg9.0 and emulsion E-2B of pAg8.0 were prepared. These emulsions were octahedral monodisperse emulsions having an average grain size of 0.70 μm.

Next, 365 mg of sensitizing dye No. 14 per mol of silver halide emulsion
And 17 mg of sensitizing dye No. 16 and 7.2 mg of sodium thiosulfate
And 10.9 mg of chloroauric acid and 60 mg of ammonium thiocyanate
Was added in the order of addition shown in Table 1 to perform chemical aging. The temperature at this time was 55 ° C., and the time after addition of the chemical sensitizer was 60 minutes. At the end of this chemical ripening, 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene 2 × 10 ^-2
An emulsion layer liquid was prepared by stabilizing the compound by using moles and further adding the following emulsion layer additives. For the protective layer, a protective layer solution was prepared by adding the following protective layer additives to gelatin. The emulsion layer additives are as follows. That is, as an additive, 400 mg of t-butyl-catechol per 1 mol of silver halide, polyvinylpyrrolidone (molecular weight 10,000) 1.0
g, styrene-maleic anhydride copolymer 2.5 g, trimethiol propane 10 g, diethylene glycol 5 g, nitrophenyl-triphenylphosphonium chloride 50
mg, 1,3-dihydroxybenzene-4-sulfonic acid ammonium 4 g, 2-mercaptobenzimidazole-5-
Sodium sulfonate 15 mg, 1,1-Dimethylol-1-bromo-1-nitromethane 10m
g, a hardener, etc. were added.

The protective layer additives are as follows. That is, the following compounds were added as additives. Per 1 g of gelatin, 7 mg of matting agent made of polymethylmethacrylate having an average particle diameter of 5 μm, 70 mg of colloidal silica having an average particle diameter of 0.013 μm
And a hardener etc. were added.

Next, a silver halide emulsion layer and a protective layer were simultaneously coated in layers from the support on both sides of the polyester film support that had been subbed by the slide hopper method, and sample Nos. 1 to N
got o.9.

Each of the resulting samples was divided into three parts, one part was given a sensitometric exposure in 1/125 seconds and one part was given a sensitometric exposure in 10 seconds. The remaining part was allowed to stand for 7 days under the conditions of 55 ° C. and 20% RH, and then subjected to sensitometric exposure for 1/125 seconds. Table 2 shows the fog density and sensitivity when the development processing was performed using the developing solution XD-90 (manufactured by the same company) with the automatic processor GX-300 (manufactured by Konishi Rokusha Kogyo Co., Ltd.).

In Table 2, the sensitivity was calculated from the amount of exposure that gives a density of fog +0.20, but is expressed as a relative value when each value of Sample 1 is 100.

However, the sensitivities after treatment after being left for 7 days at 55 ° C. and 20% RH are expressed as the variation rate from the untreated sensitivity of each sample.

As is clear from Table 2, sample Nos. 3, 6, 7, and
8 and 9 have high sensitivity and high low-light exposure sensitivity, and also at 55 ℃, 20
% RH There is little increase in fog after processing for 7 days, and there is little desensitization due to increased fog. Further, among the samples of the present invention, it can be seen that the emulsion used is monodisperse (No. 6, 7, 8, 9) and gives better results than the polydisperse emulsion (No. 3).

Example-2 A monodisperse core-shell emulsion having an average particle size of 0.70 .mu.m was prepared by the method described in JP-A-61-245151, divided into two after completion of grain growth, and the desalting degree was controlled for each emulsion of pAg 9.0. E-3A
And pAg8.0 emulsion E-3B were prepared. Further, the emulsion E-3A was divided into three to obtain pAg8.3 with silver ions.
Emulsion E-3D with 8.0 was prepared. Emulsion E-3B was added to 2
Emulsion E-3E having pAg 7.0 with silver ions was obtained by dividing.
Table 3 shows the iodide composition ratio of each E-3 emulsion.

Next, 210 mg of sensitizing dye No.2, 8.0 mg of sodium thiosulfate, 6.0 mg of chloroauric acid, and 30 mg of ammonium thiocyanate were added per 1 mol of silver halide in the order of addition shown in Table 4 to perform chemical ripening. went. The temperature at this time was 55 ° C., and the time after addition of the chemical sensitizer was 90 minutes. At the end of this chemical ripening, stabilization was carried out with 2 × 10 ^-2 mol of 4-hydroxy-6-methyl-1,3,3a, 7-tetrazaindene, and further yellow coupler (Y-1) was added to 8 × 10. ^-2 mol, in addition to the addition of surfactants and hardeners, the emulsion thus prepared is coated on a triacetyl cellulose film support provided with an undercoat layer, Sample No. 10 to No. 19 Got

Each of the obtained samples was divided into three parts, and 1 part was subjected to white light sensitometric exposure in 1/100 seconds and 1 part was subjected to white light sensitometric exposure in 10 seconds. The remaining part is 55 ° C,
After standing for 7 days under the condition of 20% RH, white light sensitometric exposure was given for 1/100 second. The following development processing was performed on each sample.

Treatment process (38 ℃) Color development 3 minutes 15 seconds Bleach 6 minutes 30 seconds Water washing 3 minutes 15 seconds Fixing 6 minutes 30 seconds Water washing 3 minutes 15 seconds Stabilization 1 minute 30 seconds Dry Used in each processing step The composition of the treatment liquid is as follows.

<Color developer> 4-amino-3-methyl-N-ethyl-N- (β-hydroxyethyl) -aniline / sulfate 4.75 g anhydrous sodium sulfite 4.25 g hydroxylamine / 1/2 sulfate 2.0 g anhydrous potassium carbonate 37.5 g Sodium bromide 1.3 g Nitrilotriacetic acid trisodium salt (monohydrate) 2.5 g Potassium hydroxide 1.0 g Add water to make 1.

<Bleach> Ethylenediaminetetraacetic acid iron ammonium salt 100. g Ethylenediaminetetraacetic acid diammonium salt 10.0 g Ammonium bromide 150.0 g Glacial acetic acid 10.0 ml Water is added to adjust the pH to 6.0 using ammonia water.

<Fixing solution> Ammonium thiosulfate 175.0g Anhydrous sodium sulfite 8.5g Sodium metasulfite 2.3g Add water to make 1 and adjust the pH to 6.0 with acetic acid.

<Stabilizer> Formalin (37% aqueous solution) 1.5 ml Conidax (Konishi Rokusha Kogyo Co., Ltd.) 7.5 ml Add water to make 1.

The results are shown in Table 5. The sensitivity is expressed as a relative value when the value of Sample 10 is 100.

Also, the sensitivity after treatment after leaving it at 55 ° C, 20% RH for 7 days is
Expressed as the percent change from the untreated sensitivity of each sample.

As is apparent from Table 5, Sample No. 12, 1 of the present invention
Nos. 5,16,17,18 and 19 have high sensitivity and high sensitivity to low illuminance exposure, and the increase in fog after treatment after leaving them to stand at 55 ° C and 20% RH for 7 days is also small. Few. Further, among the samples of the present invention, the one using the monodisperse core-shell emulsion (No. 15, 16, 17, 18 and 19) is more preferable than the one using the monodisperse emulsion (No. 12). It turns out that it gives good results. Furthermore, the pAg adjustment method performed with silver ions (No. 17, 18, 19) has the same performance.

Example-3 Instead of using 210 mg of sensitizing dye No. 2 in Example-2, 210 mg of sensitizing dye No. 60 and 30 mg of sensitizing dye No. 12 were used.
Furthermore, instead of the yellow coupler, the cyan coupler (C-1) was changed to 3.5 × 10 ^-2 mol. Others were carried out similarly and sample No.20-No.29 was obtained.

Each of the obtained samples was divided into three parts, and 1 part was subjected to red light sensitometric exposure with a Ratten filter No. 26 in 1/100 seconds and 1 part was subjected to red light sensitometric exposure in 10 seconds. The remaining 1 part was left for 7 days under the conditions of 55 ° C. and 20% RH, and then exposed to red light for 1/100 second. The same development processing as in Example-2 was performed.

The results are shown in Table 6. The sensitivity is expressed as a relative sensitivity value when the value of Sample 19 is 100.

Also, the indication of the processed sensitivity after leaving it at 55 ° C, 20% RH for 7 days is the same as in Examples 1 and 2, and the variation rate (%) from the untreated is
Express with.

The developed sample exposed at 1/100 second was printed on color paper at a magnification of 10 times, and the graininess was visually observed.
The results are represented by the following criteria: ○ Improvement △ No change × Deterioration.

As is apparent from Table 6, Sample No. 22, 2 of the present invention
Nos. 5,26,27,28 and 29 have high sensitivity and high sensitivity to low illuminance exposure. Also, there is little increase in fog after processing when left at 55 ° C, 20% RH for 7 days, and the sensitivity due to fog also increases. Few. Further, the graininess is also good, and the effect of the present invention is clear.

Example-4 In this example, it was confirmed that the effect was brought about when pAg was within the range of the present invention.

That is, here, the emulsion E-3A of Example-2 was pA with silver ions.
Emulsion E-3F with g8.5 was prepared, and emulsions E-3B, E-3G, E-3H, and E-3I with pAg 6.7, 6.3, and 6.0 were added to emulsion E-3B.
Was prepared, and sample Nos. 13A, 16A, 16B, and 16C were prepared using these.

Next, Table 7 shows the addition compounds and the order of addition.

The results of evaluation of each sample in the same manner as in the above example are shown in Table 8 below. Table 8 shows that excellent results were obtained in the pAg range of the present invention.

Comparative Example Here, it is shown that the effect cannot be obtained when ammonium thiocyanate is not used as the silver halide solvent.

That is, here, the same applies to Sample Nos. 3 and 6 of Example-1 (all of which are samples according to the present invention), except that 60 mg of ammonium thiocyanate used was replaced with the equivalent thioether compound A-2. Then, sample Nos. 3A and 6A were prepared.

The results of the same evaluation as in Example 1 are shown in Table 9 below. From Table 9, it can be seen that these comparative samples do not give favorable results.

[Effects of the Invention] As described above, according to the present invention, it is possible to obtain a highly sensitive light-sensitive material with less fog increase during storage over time and improved storability, and improved low illuminance sensitivity failure, and graininess. A good photosensitive material can be obtained.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-55-26589 (JP, A) JP-A-59-148050 (JP, A) JP-A 61-160739 (JP, A) JP-A 61- 210345 (JP, A)

Claims (1)

[Claims] 1. At least one photosensitive layer containing a silver halide emulsion having a pAg of 6.5 to 8.4 and chemically ripened in the presence of a sensitizing dye and a thiocyanate which is a silver halide solvent. A silver halide photographic light-sensitive material characterized by: