JPS63305344A - Improved silver halide photographic sensitive material having less secular fogging, or the like - Google Patents

Abstract

PURPOSE:To lessen the increase of the fogging at the time of secular preservation, and to improve the sensitivity and the irregular sensitivity caused by a low illumination and the graininess of the titled material by providing with at least one layer of photosensitive layers contg. a silver halide emulsion which has <=8.5pAg, and is chemically aged in the presence of a sensitizing dye, in the titled material. CONSTITUTION:The titled material comprises at least one layer of the photosensitive layers contg. the silver halide emulsion which has <=8.5pAg and is chemically aged in the presence of the sensitizing dye. At the time of chemically aging the silver halide emulsion in the presence of the chemical sensitizing agent and sensitizing dye, pAg is preferably <=8.5 for at least one-third chemical aging time, especially, preferably <=8.5 for at least two-third chemical aging time in the first half of the chemical aging time. The additional amount of the sensitizing dye depends on the particle sized of the used silver halide emulsion and the crystal habit thereof, however, preferably 20-750mg per 1mol. of silver halide. Thus, the titled material having the less increase of fogging at the time of secular preservation, and the improved shelf life and the good graininess is obtd., and the irregular sensitivity caused by the low illumination is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a silver halide photographic light-sensitive material, and more specifically, to a method for reducing the increase in capri of a light-sensitive material over time,
The present invention also relates to a silver halide photographic material which reduces sensitivity failure during low-light exposure and also has improved graininess.

[Background of the invention]

Many proposals have been made to prevent deterioration of photographic performance over time, including for black and white photosensitive materials and color photosensitive materials.For example, regarding the occurrence of undesirable fog due to the effects of temperature and humidity over time, It has been known to add antifoggants or stabilizers to silver halide emulsions. Commonly known patents include U.S. Patent No. 2.403.927 and U.S. Patent No. 3.804.
．． 1-phenyl-5-mercaptotetrazoles described in each specification of No. 633, Japanese Patent Publication No. 39-2825, etc., or 4-hydroxy-6-methyl-1,3,3a
, 7-chitrazaindene, etc. are available.

However, these compounds have the disadvantage that although they suppress capri to some extent over time, they are not sufficient or are accompanied by significant desensitization when added to silver halide emulsions in amounts sufficient to prevent fog. On the other hand, with the development of high-sensitivity photosensitive materials, technology in the bridge field has expanded greatly, and in contrast to bridge shapes using high-speed shutters,
Bridge-shaping technology using a low-speed shutter is also used for astrophotography and bridge-shaping in theaters and museums where strobes cannot be used.

The photographic performance that becomes a problem in such cases is the reciprocity failure characteristic, and not only the high-illuminance failure characteristic but also the low-illuminance failure characteristic must be good. In other words, conventional photosensitive materials do not necessarily have good low-light failure characteristics; for example, even if a certain aperture value is set when taking astrophotography, the sensitivity is insufficient at that brightness, and calculations are required to obtain the appropriate exposure amount. more than twice the value,
In some cases, it took more than four times as long.

Proposals for improving the sensitivity reduction and gradation variation as reciprocity law failure characteristics have been made for a long time, but these are still insufficient in view of the advances in technology in each of the above-mentioned fields.

[Purpose of the invention]

An object of the present invention is to provide a highly sensitive photosensitive material with improved storage stability and less increase in fog during storage over time, and also to provide a photosensitive material with improved low-light sensitivity failure and good graininess. It's about doing.

[Structure of the invention]

As a result of intensive research, the inventors found that I) Ag is 8.5
It has been found that the above objectives can be achieved by a photosensitive material having at least one photosensitive layer containing a silver halide emulsion which has been chemically ripened in the presence of a sensitizing dye.

The present invention is based on the following findings discovered by the present inventors. In other words, it is well known among those skilled in the art that the setting of pAg when chemically ripening an emulsion has a sufficient effect on how the chemical ripening takes place.
A sensitization method in which ripening is performed at a temperature of about 4 to 5 has been known for a long time. However, if chemical aging is simply carried out with a low PAg setting, although the chemical aging will be completed in a short time, the fog may be unstable, for example, fog may increase due to storage over time, or if the same chemical aging is applied. There may be problems with reproducibility over time. If antifoggants or the like are used in combination as a countermeasure, other problems will occur as mentioned above, and this will not be a fundamental solution.

However, after various studies by the present inventors, pA
If chemical ripening is performed in the presence of a sensitizing dye when g is 8.5 or less, the relationship between fog and sensitivity will be better than when chemical ripening is performed with higher I)Ag, and fog stability will be improved. The inventors of the present invention have discovered that the granularity is improved, the low-light sensitivity failure is reduced, and the graininess is improved, and these results were unexpected even for the inventor. Ta.

The present invention will be explained in more detail below.

In the present invention, at least 11i of photosensitive layers containing a silver halide emulsion having a pAg of 8.5 or less and chemically ripened in the presence of a sensitizing dye are provided, and the silver halide photographic light-sensitive material of the present invention shall be.

The pAg during chemical ripening is determined by the short chemical ripening time in the presence of both a chemical sensitizer and a sensitizing dye (both 1/3 is 8.5
It is preferably at most 8.5, and particularly preferably at least two-thirds of the first half of the chemical ripening time is at most 8.5.

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

In the present invention, chemical ripening can be achieved by any chemical sensitization 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.

In addition, when using a gold compound, ammonium thiocyanate and sodium thiocyanate can also be used together.

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

As selenium sensitizers, active and inactive selenium compounds can be used.

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

As a chemical sensitizer that can more fully exhibit the objectives and effects of the present invention, a combination of a noble metal sensitizer and a sulfur sensitizer is preferred.

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

In the light-sensitive material of the present invention, at least one light-sensitive layer contains a silver halide emulsion obtained by chemically ripening an emulsion with a pAg of 8.5 or less.

In the present invention, the pAg of the emulsion subjected to chemical ripening is adjusted to the above value in order to control the removal rate when unnecessary soluble salts are removed after the growth of silver halide grains in the emulsion is completed. , or by adding silver ions or halide ions, thereby setting the desired pAg value.

The pAg to which chemical ripening is applied is 8.5 or less, but the preferred value is in the range of 8.4 to 6.5, and more preferably in the range of pAg 8.2 to 7.1. .

Further, in the present invention, 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, cyanine dyes or merocyanine dyes such as zeromethine dye, monomethine dye, dimethine dye, trimethine dye, etc. can be used alone or in combination, and can be selected depending on the purpose. can.

The sensitizing dye according to the present invention may be added to the silver halide emulsion as long as it is present during chemical ripening, but the specific pattern of addition conditions is as follows:
Chemical sensitizer ■ pAgtJl - chemical sensitizer - sensitizing dye ■ Sensitizing dye - pAgiji chemical sensitizer ■ Sensitizing dye - chemical sensitizer - pAgl! Adjustment (1) Chemical sensitizer - sensitizing dye - pAg adjustment (2) Chemical image sensitizer - pAgfl adjustment - It is also possible to simultaneously add the sensitizing dye and two of the above-mentioned adjoining substances (1) to (2). Here, the pAg adjustment includes addition adjustment using silver ions or halide ions in addition to controlling the degree of desalination after grain growth is completed. (1), (2), and (2) are preferable. In the case of (1), (2), and (2), it is preferable to add the sensitizing dye within 15 minutes after adding the chemical sensitizer.

More preferred are ■, ■, and ■.

In addition, in order to add a sensitizing dye to a silver halide emulsion, it can be added after being dissolved in water or an organic solvent miscible with water such as methanol or ethanol. You may use it in combination of more than one kind.

In the present invention, the amount of sensitizing dye added varies depending on the grain size, crystal habit, etc. of the silver halide emulsion used, and the optimum amount of sensitizing dye added is determined by a method commonly used by those skilled in the art. but usually preferably 20 750 +++ g, more preferably 50 g per mole of silver halide.
It is 450a+g.

Typical specific 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]

■ CH3 CZU% andttls (Glh)s
sIJs 1g U dew 11s C,H.

tHs GHzGHzOH shiu, shiuu+'I (22). □2゜Hz. □
Js しい-L;tl”L+tl! UsNa 〇ot e りし寞Hs (3 days) υ しH2C; 11rishiH: 5U3i1 ・N (L;ttlsJ 5COCI
(s (CHz)s 弌5su, ma SυkoNa0s
e 0se so, e SOsH5O2e 5UsNa L; ULI MA ISrL' In the present invention, chemical ripening is more preferably carried out in the presence of a silver halide solvent.

Silver halide solvents preferably used in the chemical ripening according to the present invention include (a) U.S. Patent No. 3.271°15;
7, 3.531.289, 3.574.6
28 specifications, JP-A No. 54-1019, JP-A No. 54-1
Organic onythyl compounds described in No. 58917 and No. 62-14646, etc., JP-A-53-8240
Thiourea derivatives described in No. 8, No. 55-77737 and No. 55-29829, etc., (e) JP-A No. 5
AgX solvent having a thiocarbonyl group sandwiched between an oxygen or sulfur atom and a nitrogen atom described in JP-A No. 3-144319, (d+imidazole described in JP-A-54-100717, (e) Sulfites, (f) thiocyanates, (g) hydroxyalkyl-substituted ethylenediamines described in JP-A No. 57-196228, (h) substituted mercaptotetrazoles described in JP-A-57-202531, etc. can be mentioned.

Next, specific examples of these (al to (N) silver halide solvents will be given. However, the silver halide solvents that can be used in the present invention are not limited to the following examples.

(a) A 3 80 (CHg)t S (CH
t)t S (Cut)g OHA 4
GHz NHCOCHtCHtCOOHCHg
S CHtCHzSCtHsCHg NHCOCH
tCHtCHsCHg S CHtCHtSCH*
CHtCOOH(b) (c) (d) H3 (e) E I KzSOs(f) (g) (h) H3 The amount of silver halide solvent present during chemical ripening of the silver halide emulsion is 0. 0005 to 1.0g, more preferably 0.001 to 0.0g.
5 g, particularly preferably 0.005 to 0.2 g.

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

7, ητL Below: Lower white \- and Near Examples of the silver halide in the silver halide emulsion according to the present invention include silver bromide, silver iodobromide, silver iodochloride, silver chlorobromide, and silver chloride. Any material commonly used in silver halide emulsions, such as silver bromide and silver chloride, can be used, but silver iodobromide is particularly preferred.

The silver halide grains used in the silver halide emulsion may be obtained by any of the acid method, neutral method, and ammonia method. The grains may be grown all at once or after forming seed grains. You can let it grow. The method of creating and growing the seed particles may be the same or different.

When preparing a silver halide emulsion, halide ions and silver ions may be mixed simultaneously, or one may be mixed in a liquid in which the other is present.

Also, while considering the critical growth rate of silver halide crystals,
pHSpA in a pot mixing silver halide ions and silver ions
It may also be produced by sequentially and simultaneously adding them while controlling the amount of g. By this method, silver halide grains having a regular crystal shape and a nearly uniform grain size can be obtained.

Conversion methods may be used at any step of the silver halide formation to change the halogen composition of the grains.

Known silver halide solvents such as ammonia, thioether, thiourea, etc. can be present during the growth of silver halide grains.

During the process of grain formation and/or growth, silver halide grains are produced using cadmium salts, zinc salts, lead salts, thallium salts, iridium salts (including complex salts), rhodium salts (including complex salts), and iron salts ( Metal ions can be added using at least one selected from the group consisting of complex salts) to contain these metal elements inside the particles and/or on the surface of the particles.

The silver halide grains may have a uniform silver halide composition distribution within the grain, but it is more preferable to have a core/silver halide composition in which the interior and surface layer of the grain have different silver halide compositions.
Preferably they are shell particles.

The silver halide grains may be such that the latent image is mainly formed on the surface, or may be such that the latent image is mainly formed inside the grain.

The silver halide grains may have a regular crystal shape such as a cube, octahedron, or dodecahedron, or may have an irregular crystal shape such as a spherical shape or a plate shape. In these particles, any ratio of the (100) plane to the (111) plane can be used. Further, the particles may have a composite form of these crystal forms, or particles of various crystal forms may be mixed.

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

Further, regarding the grain size distribution of the silver halide emulsion, any grain size distribution may be used.

An emulsion with a wide grain size distribution (referred to as a polydisperse emulsion) may be used, or an emulsion with a narrow grain size distribution (referred to as a monodisperse emulsion). A particle with a value of 0.20 or less when divided by the average grain size.The grain size is the diameter in the case of spherical silver halide, and the projection of the grain in the case of grains with a shape other than spherical. (This shows the diameter when the image is converted into a circular image with the same area.)
may also be used. However, it is more preferable to use a monodisperse emulsion.

Antifoggants, stabilizers, etc. can be added to the silver halide emulsion. It is advantageous to use gelatin as the binder for the emulsion.

The emulsion layer and other hydrophilic colloid layers can be hardened and can 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 light-sensitive material for color photography, a coupler is used in the emulsion layer.

Furthermore, colored couplers that have a color correction effect, competitive couplers, and accelerators that accelerate development by coupling with oxidized forms of developing agents, bleach accelerators, developers, silver halide solvents, toning agents, hardeners, etc. Compounds that release photographically useful fragments such as film agents, capri agents, antifoggants, chemical sensitizers, spectral sensitizers, and desensitizers can be used.

In carrying out the present invention, the photosensitive material includes a filter layer,
Auxiliary layers such as antihalation layers and antiirradiation layers can be provided. These layers and/or the emulsion layer may contain dyes that are leached from the light-sensitive material or bleached during the development process.

Furthermore, a formalin scavenger-3 fluorescent brightener, a matting agent, a lubricant, an image stabilizer, a surfactant, a color fog preventive agent, a development accelerator, a development retardant and a bleach accelerator can be added to the photosensitive material.

As a support, paper laminated with polyethylene, etc.
Polyethylene terephthalate film, baryta paper, cellulose triacetate, etc. can be used.

In order to obtain an image using the photosensitive material of the present invention, commonly known color or black and white photographic processing may be performed after exposure.

Refer to the following: [Examples] Specific examples of the present invention will be described below, but the 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 sequential mixing using the fluammonia method. After the particle growth is completed, divide into two parts, control the desalination degree of each, and measure pA g 9.
Emulsion E-IA with a g of 0 and emulsion E- with l) A g of 8.0.
Created IB. These emulsions have an average grain size of 0.70μ
It was a polydisperse emulsion of m.

Next, 45°C, pA g-11,0, pH=9.0
3. An ammoniacal silver nitrate solution of ON and a solution containing 3.0 mol % of potassium bromide and potassium iodide were added to the gelatin solution by a double jet method. The addition rate was gradually increased as the particles grew.

After grain growth is completed, the grain is divided into two parts, and the degree of desalination is controlled.
p A g 9. Emulsion E-2A of O and pAg8,0
Emulsion E-2B was prepared. These emulsions have an average grain size of 0
．． It was an octahedral monodispersed emulsion of 70 μm.

Next, 3 sensitizing dye N114 was added per mole of silver halide emulsion.
Chemical ripening was performed by adding 65 mg of sensitizing dye No. 16, 17 mg of sensitizing dye No. 16, 7.2 mg of sodium thiosulfate, 10.9 mg of chloroauric acid, and 60 mg of ammonium thiocyanate in the order shown in Table 1. . The temperature at this time is 5
At 5°C, the time after chemical sensitizer addition was 60 minutes.

At the end of this chemical ripening, 4-hydroxy-6-methyl-1
,3,3a,? -stabilized with 2 x 10-'' moles of tetrazaindene and further added with the following emulsion layer additives:
An emulsion layer solution was prepared. Further, for a 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 g of t-methyl-catechol per mole of silver halide was added to polyvinylpyrrolidone (molecular weight 10.0 g).
00) 1.0g, styrene-maleic anhydride copolymer 2.5g,) Limethylolpropane Log, diethylene glycol 5g1 Nitrophenyl-triphenylphosphonium chloride 5Qmg, 1.3-dihydroxybenzene-4-sulfonate ammonium 4g12 -Mercaptobenzimidazole-5-sulfonic acid soda 1
5mg.

10 mg of H tyrol-1-bromo-1-nitromethane, a hardening agent, etc. were added.

Further, the protective layer additives are as follows. That is, the following compounds were added as additives. Per 1g of gelatin, CHzCOO(C)It)9CH3 CHCOO(CH*)tcH(CH+)t 711
18103Na 7 mg of a matting agent made of polymethyl methacrylate with an average particle size of 5 μm and a colloid with an average particle size of 0.013 μm. Then, using the slide hopper method, both sides of the undercoated polyester film support were simultaneously halogenated in order from the support. Samples 11hl to 1l were coated with a silver emulsion layer and a protective layer.
I got h9.

The resulting sample was each divided into three parts, one part was given a sensitometric exposure at 1/125 seconds and one part was given a sensitometric exposure at 10 seconds. The remaining part is kept at 55℃ and 20%
After standing under RH conditions for 7 days, a sensitometric exposure was given at 1/125 seconds. For each, use developer
Table 2 shows the fog density and sensitivity when developed using D-90 (manufactured by the same company).

In Table 2, the sensitivity was calculated from the exposure amount that gives a density of fog + 0.20, but each value of Sample 1 was calculated by 10
It is expressed as a relative value when it is set to 0.

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

As is clear from Table 2, sample sizes 3, 6,
7 and 8.9 have high sensitivity and low light exposure sensitivity, and 5.
After being left at 5°C and 20% RHT for a day, there was little increase in capri, and there was also little desensitization due to the increase in capri.Also, among the samples of the present invention, the emulsion used was polydisperse (Na3
) more monodisperse <*6,7.

8.9) gives better results.

Example 2 The average particle diameter was 0.
A monodisperse core-shell emulsion with a diameter of 70 μm was prepared, and after grain growth was completed, it was divided into two parts, and the degree of desalination was controlled in each part to give a pA g
9.0 (7) Emulsion E-3A and emulsion E-3B with p A g of 8.0 were prepared. Furthermore, emulsion E-3A was divided into three parts to obtain emulsion E-3, which had a p A g of 8.3 with silver ions.
Emulsion E-3D with C and pAg of 8.0 was prepared. In addition, emulsion E-3B was divided into two parts and pAg7 was added with silver ions.
．． Emulsion E-3E was obtained. Table 3 shows the legal composition ratio of each emulsion E-3.

Next, add 210 m of 210 m of mulch dye per mole of silver halide.
g, sodium thiosulfate 8.0mg and chloroauric acid 6.0@
and 30 mg of ammonium thiocyanate were added in the order of addition shown in Table 4 to perform chemical ripening. 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, 4-hydroxy-6-
Methyl-1,3,3a,7-chitrazaindene 2X10
−” moles and further stabilized with yellow coupler (Y
-1) was added to 8 x 10-'' moles, and a surfactant and a hardening agent were added, and the emulsion thus prepared was coated on a triacetyl cellulose film support on which an undercoat layer was provided. I got 19.

Table 3 The resulting samples were each divided into three parts, one part was given a white light sensitometric exposure at 1/100 seconds and one part was given a white light sensitometric exposure at 10 seconds. Also, the remaining part is
After being left for 7 days at 55°C and 20% RH, 1/
A white light sensitometric exposure was given for 100 seconds. Each sample was subjected to the following development treatment.

Yellow coupler (Y-1) Processing process (38℃) Color development Bleaching for 3 minutes 15 seconds
Wash with water for 6 minutes and 30 seconds
Fixed for 3 minutes and 15 seconds
Wash with water for 6 minutes and 30 seconds
Stabilization for 3 minutes and 15 seconds Drying for 1 minute and 30 seconds The composition of the treatment liquid used in each treatment step 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 .0g Anhydrous potassium carbonate 37.5g Sodium bromide 1.3g Nitrilotriacetic acid trisodium salt (monohydrate) 2.5
g Potassium hydroxide Add 1.0g water to make 11.

Bleach solution> Ethylenediaminetetraacetic acid iron ammonium salt 100. g
Ethylenediaminetetraacetic acid diammonium salt 10.0 g
Ammonium bromide 150.0
g Glacial acetic acid 10.0m
Add 1 liter of water to make 1 liter, and adjust the pH using ammonia water.
Adjust to -6,0.

Fixer> Ammonium thiosulfate 175.0 g
Anhydrous sodium sulfite 8.5g Sodium metasulfite 2.3g Add water to make 11, and adjust the pH to -6.0 using acetic acid.

(Stabilizer) Formalin (37% aqueous solution) 1.5
mm! Conidax (manufactured by Konishiroku Photo Industry Co., Ltd.) 1.
Add 5al water to make 11.

Table 5 shows the results. Sensitivity is the value of sample 10 as 100
It is expressed as a relative value when .

In addition, the sensitivity after processing of samples left for 17 days (55℃, 20% R) is the rate of change (%) from the untreated sensitivity of each sample.
Expressed as

As is clear from Table 5, sample 11h1 of the present invention
2.15.16.17.18 and 19 have high sensitivity and high low-light exposure sensitivity, and there is little increase in capri after processing when left at 55°C and 20% RHT, and there is also a decrease due to increased fog. There is little feeling. Furthermore, among the samples of the present invention, the emulsion used was a monodisperse core-shell emulsion (m15.16.17°18) rather than a monodisperse emulsion (N112).
and 19) are found to give better results.

In addition, pAg adjustment method using silver ion (Na
l? , 18.19) have the same performance.

Example 3 In Example 2, instead of using 210 mg of sensitizing dye 2, 210a+g of sensitizing dye 11 & 160, 3 parts g of sensitizing dye Magnet 12, and in place of Yellow Cub and Ra. Cyan coupler (C-1) 3.5X
The method was changed to adding 10-''mol.Other than that, the procedure was carried out in the same manner, and samples No. 20 to N129 were obtained.

The resulting sample was each divided into three parts, one part was given a red light sensitometric exposure with a cyan filter N126 at 1/100 seconds and one part was given a red light sensitometric exposure for 10 seconds. The remaining portion was left for 7 days at 55° C. and 20% RH, and then exposed to red light at 1/100 second. The same development treatment as in Example-2 was carried out for each.

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

Furthermore, the sensitivity of the treated samples left for 17 days at 55° C. and 20% R) is expressed as the rate of change (%) from the untreated sample, as in Examples 1 and 2.

Further, a developed sample exposed to 1/100 seconds was printed on color paper at a magnification of 10 times, and the graininess was visually observed. The results are as follows: ○ Improvement △ No change × Deterioration As is clear from Table 6, sample N112 of the present invention
2.25.26, 27.28, and 29 have high sensitivity and high low-light exposure sensitivity, and also have little increase in fog after processing when left at 55°C and 20% RHT, and also have low sensitivity due to fog. The effect of the present invention is obvious, with less stagnation and good graininess.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a highly sensitive photosensitive material with improved storage stability and less increase in fog during storage over time, and also to obtain a photosensitive material with improved low-light sensitivity failure and good graininess. Obtainable.

Claims (1)

[Claims] 1. A silver halide photographic material having at least one photosensitive layer containing a silver halide emulsion having a pAg of 8.5 or less and chemically ripened in the presence of a sensitizing dye.