JPH0229639A - Silver halide photographic sensitive material improved in pressure desensitization - Google Patents

Abstract

PURPOSE:To provide high sensitivity, low fogging and good pressure resistance by incorporating a silver halide emulsion obtd. by flocculating silver halide particles together with a protective colloid by a flocculating high polymer agent and removing the dissolved matter into a soln. contg. the protective colloid which contains a thioether compd. CONSTITUTION:This photosensitive material has at least one layer of the photosensitive silver halide emulsion layers on at least one side of a base. The emulsion in this case is prepd. by adding a water soluble silver salt soln. and a water soluble silver halide soln. into a soln. contg. the protective colloid in which the thioether compd. is made to exist; thereafter, the formed silver halide particles are flocculated together with the protective colloid by the flocculating high polymer agent from the suspension and the dissolved matter in the suspension is removed to obtain the emulsion. The high sensitivity, the low fogging and the good pressure resistance are obtd. in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a silver halide photographic material having high sensitivity, low capri, and excellent pressure resistance.

[Background of the invention]

In recent years, the consumption of silver halide photographic materials has continued to increase. For this reason, the number of silver halide photographic materials to be processed has increased, and there is a demand for speeding up the development processing of the negative layer, that is, increasing the processing amount within the same amount of time.

The above-mentioned trend is also observed in the field of X-ray sensitive materials, such as medical X-ray films. That is, the number of medical examinations is rapidly increasing due to the enforcement of regular health examinations, and the number of examination items is increasing in order to make the diagnosis more accurate, and the number of X-ray photographs is increasing.

On the other hand, it is also necessary to inform the patient of the diagnosis as soon as possible.

In other words, there is a strong demand for faster development and diagnosis than before. Particularly in angiography photography, intraoperative photography, etc., it is essentially necessary to view the photographs as quickly as possible.

To meet the above demands of the medical community, there is a need to process X-ray films more rapidly, as well as to facilitate diagnostic automation (imaging, transport, etc.).

However, when ultra-rapid processing is performed, there is a problem that the density is not sufficient (decrease in sensitivity, contrast, and maximum density).

Recently, especially with the increase in medical X-ray examinations, reductions in radiation doses have been strongly demanded not only by the medical community but also by international public opinion. For this reason, there is a desire to develop photographic materials that can provide precise images with a small amount of X-rays, that is, photographic materials with even higher sensitivity.

Conventionally, there are various techniques for increasing sensitivity, that is, sensitization methods. With appropriate sensitization techniques,
It is expected that it will be able to increase sensitivity while maintaining its power. This technique includes, for example, adding a development accelerator such as thioethers to the emulsion, supersensitizing spectrally sensitized silver halide emulsions with a suitable combination of dyes, and adding optical sensitizers to the emulsion. Many improved technologies have been reported. However, it cannot be said that these methods are necessarily versatile for high-sensitivity silver halide photographic materials. That is, silver halide emulsions for use in high-sensitivity silver halide photographic light-sensitive materials are subject to maximum chemical sensitization as much as possible, and the above method tends to cause fogging during storage.

Furthermore, in the field of medical X-ray photography, from the conventional regular type photosensitive material, which was sensitive to a wavelength range of 450 nm, to the ortho-sensitized, ortho-type photosensitive material that is sensitive to a wavelength range of 540 to 550 nm. ing. Those sensitized in this manner have a wider photosensitive wavelength range and higher sensitivity, and therefore can reduce the amount of X-rays that they are exposed to and lessen the impact on the human body. Although dye sensitization is thus an extremely useful means of sensitization, there are still many unresolved problems, such as the inability to obtain sufficient sensitivity depending on the type of photographic emulsion used.

As a method for preventing fog, it is well known to use indazoles and penztriazoles as antifoggants in developer solutions. Both have been used for this purpose in both black and white developers and color developers. Among the numerous patent specifications cited for this type of application are U.S. Pat.
British Patent No. 1,437.0 describing the use of indazoles as antifoggants in X-ray developers
No. 53, and US Pat. No. 4,172,728, which describes the use of indazoles as antifoggants in graphic arts developers.

Although indazoles and penztriazoles are very effective antifoggants, they have the problem of a large decrease in sensitivity.

Various mechanical pressures applied before exposure can cause pressure desensitization (desensitization observed during development due to mechanical pressure before exposure). For example, since medical X-ray film is large in size, it may bend under its own weight from the supported part, or film bending such as so-called claw folding, which can lead to pressure desensitization.

Furthermore, in recent years, automatic exposure and development devices using mechanical conveyance have been widely used as medical X-ray photography systems.
Mechanical forces are applied to the film in such devices, and the above-mentioned pressure deterioration and pressure desensitization are likely to occur, especially in dry areas such as in winter. Such a phenomenon may cause serious problems in medical diagnosis. It is well known that pressure desensitization is particularly likely to occur in photographic materials having large grain size and highly sensitive silver halide grains. U.S. Pat. No. 2,628.167 and U.S. Pat. No. 2,75
9°822, 3,455.235, 2,296
．． No. 204, and French Patent No. 2,296.204,
JP-A-51-107129 and JP-A No. 50-116025
For example, methods using thallium and dyes are described in the No. 1, etc., but these improvements are insufficient.

[Purpose of the invention]

The object of the present invention is high sensitivity and low fog.

It is an object of the present invention to provide a silver halide photographic material which also has excellent pressure resistance.

[Structure of the invention]

The above object of the present invention is to provide a silver halide photographic material having at least one silver halide emulsion layer on a support, in which the silver halide emulsion layer is placed in a solution containing a protective colloid in which a thioether compound is present. It is produced by adding a water-soluble silver salt solution and a water-soluble halide solution; contains a silver halide emulsion obtained by agglomerating silver halide grains with a protective colloid using an aggregating polymer agent and removing dissolved substances. This can be achieved using silver halide photographic materials.

The present invention will be explained in more detail below.

The silver halide photographic material of the present invention has at least one light-sensitive silver halide emulsion layer on at least one side of the support.

That is, in the present invention, at least one photosensitive silver halide emulsion layer may be provided on both sides of the support to provide a double-sided photosensitive material, or it may be provided on one side to provide a single-sided photosensitive material.

The silver halide photographic material of the present invention is produced by adding a water-soluble silver salt solution and a water-soluble halide solution to a solution containing a protective colloid in which a thioether compound is present. contains a silver halide emulsion (hereinafter appropriately referred to as "emulsion according to the present invention") obtained by aggregating together with a protective colloid using an aggregating polymer agent and removing dissolved substances.

The emulsion according to the present invention may be contained in at least one emulsion layer of the light-sensitive material of the present invention, but preferably many of the emulsion layers, more preferably all of the emulsion layers contain the emulsion according to the present invention. This means that it contains Furthermore, an emulsion according to the present invention and an emulsion obtained through a different history may be used together in one emulsion layer.

The emulsion according to the present invention is prepared, for example, by adding a water-soluble silver salt solution and a water-soluble halide solution to a solution containing a protective colloid in which a thioether compound is present, and then adding the produced silver halide grains. It can be obtained by aggregating a suspension together with a protective colloid using an aggregating polymer agent and removing dissolved substances in the suspension.

Here, the thioether compound is a compound represented by the following general formula (1).

General formula CI) R1(-X-R, +-X-Rs .nZ In the formula, X represents a sulfur atom, an oxygen atom or -CNH-, and at least one is a sulfur atom.

Preferably, the number of sulfur atoms represented by X is from 1 to 4
The most preferred number is 2 or 3. Here, when m is 2 or more, X and R may be the same or different.

It is an integer of 1 to 0 or 1 to 5, preferably an integer of 1 to 5.

R1 is an alkylene group having 1 to 5 carbon atoms, preferably an alkylene group having 2 to 5 carbon atoms, and specific examples thereof include dimethylene group, trimethylene group, tetramethylene group, and methylethylene group.

R1 is an alkyl group having 1 to 5 carbon atoms and having at least one -NR4R6Ra group. Preferably 2 or more carbon atoms
5 is a substituted alkyl group.

Rs is a substituted alkyl group having 1 to 5 carbon atoms, preferably a substituted alkyl group having 2 to 5 carbon atoms.

The substituents are preferably -N R, R, R.

Here, R4, Rs, Rs, R7, Ra and R9 are alkyl groups having 1 to 5 carbon atoms.

R, , Rs, RIRF, Rs and R9 may be the same or different.

2 is an anion.

n is an integer that adjusts the charge of the molecule to neutrality.

Specific examples of thioether compounds preferably used in the present invention are shown below. Of course, it is not limited to these.

(CHa)sNCHzCHzCHzSCHzCH*5C
HzCIbC)IzN(CHs)s-2CH3[ySO
, e These exemplified compounds are described in British Patent No. 950,089, US Patent No. 3,021.215, and JP-A-62-1464.
It can be obtained by the method described in the specifications of No. 6 and the like.

Here, the solution containing a protective colloid refers to an aqueous solution in which a protective colloid is formed from gelatin or other substances that can constitute a hydrophilic colloid (substances that can act as a binder, etc.), and preferably a colloidal protective gelatin. It is an aqueous solution containing.

When carrying out the present invention, if gelatin is used as the protective colloid, the gelatin may be lime-treated or
It may be treated with an acid. Details of the method for producing gelatin are described in The Macromolecular Chemistry of Gelatin, written by Arthur Weiss (Academic Press, published in 1964).

Hydrophilic colloids other than gelatin that can be used as protective colloids include, for example, gelatin derivatives, graft polymers of gelatin and other polymers, albumin,
Proteins such as casein; cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, and cellulose sulfur ρ esters; sugar derivatives such as sodium alginate and starch derivatives; polyvinyl alcohol/ni-, polyvinyl alcohol partial acetal, poly-N-vinylpyrrolidone There are a wide variety of synthetic hydrophilic polymeric materials such as single or copolymers of polyacrylic acid, polymethacrylic acid, polyacrylamide, polyvinylimidazole, polyvinylpyrazole, and the like.

In the case of gelatin, use the baggy method with a gel strength of 200.
It is preferable to use the above.

In the photographic material of the present invention, it is advantageous to use gelatin as a hydrophilic colloid that can be used in photographic constituent layers such as a protective layer, a backing layer, and an intermediate layer, which are formed as necessary. The other hydrophilic colloids mentioned above can also be used alone or together with gelatin.

The water-soluble silver salt solution and the water-soluble halide solution are reacted to obtain the desired silver halide, and are appropriately selected and combined depending on the desired silver halide composition.

The agglomerating polymeric agent refers to a polymeric substance capable of coagulating silver halide grains together with a protective colloid. Usually, gelatin, which is a protective colloid, is agglomerated and gelled using such an aggregating polymer agent, and a step (so-called desalting step) is performed in which dissolved substances such as soluble salts in the liquid are removed.

Various types of aggregating polymeric agents can be used in the present invention, including polymeric compounds containing the A chain and B chain of the following general formula (I []) in the molecule.

General Formula (II) In the formula, R, 2, R, and 3 represent a hydrogen atom, an aliphatic group, an aryl group, or an aralkyl group, and may be different or the same. R8 represents a hydrogen atom, an aliphatic group, an aryl group, an aralkyl group, or M. Y represents 10- or -NH-. M represents a hydrogen atom, an alkali metal, a quaternary ammonium group, or a quaternary phosphonium group. p takes a value of 10-10'. The two links of the Naori chain are Rl of the A chain! +
Either side may be attached to the tertiary carbon bearing R1m. Further, when Y is -NH-, it may form a nitrogen-containing ring together with RI4. Furthermore, modified gelatin in which 50% or more of the amino groups are substituted is preferably used (hereinafter referred to as "agglomerated gelatin agent"). Examples of substituents for the amino groups of gelatin and methods for synthesizing aggregated gelatin agents are described in US Pat. No. 2,691.582, US Pat. No. 2,614.928, and US Pat.

Useful substituents include (1) acyl groups such as alkylacyl, arylacyl, acetyl, and substituted or unsubstituted benzoyl; (2) carbamoyl groups such as alkylcarbamoyl and arylcarbamoyl; (3) alkylsulfonyl and arylsulfonyl. sulfonyl groups such as (4) thiocarbamoyl groups such as alkylthiocarbamoyl and arylthiocarbamoyl, (5) linear and branched alkyl groups having 1 to 18 carbon atoms, (
6) Substituted and unsubstituted phenyl, naphthyl and pyridyl,
Examples include aryl groups such as aromatic heterocycles such as furyl.

Among them, preferred modified gelatin has an acyl group (-COR+s) or a carbamoyl group (-CON R+
s).

The RIS is a substituted or unsubstituted aliphatic group (for example, an alkyl group having 1 to 18 carbon atoms, an allyl group), an aryl group, or an aralkyl group (for example, a phenethyl group), and Ro is a hydrogen atom, an aliphatic group, It is an aryl group or an aralkyl group.

Particularly preferred is the case where R1 is a substituted or unsubstituted aryl group %Rta is a hydrogen atom.

When using an agglomerated gelatin agent for removing dissolved substances (desalting), there is no particular restriction on the amount added, but the substance contained as a protective colloid during removal (preferably gelatin)
An amount of 0.3 to 10 times (by weight) is suitable, and an amount of 1 to 5 times (by weight) is particularly preferable.

Further, after adding the agglomerated gelatin agent, the pH can be adjusted to coagulate the silver halide emulsion.

The pH for coagulation is 5.5 or less, especially 4.5 to 4.5.
2 is preferred. There are no particular restrictions on the acids used for pH adjustment, but organic acids such as acetic acid, citric acid, and salicylic acid, hydrochloric acid,
Inorganic acids such as nitric acid, sulfuric acid, and phosphoric acid are preferably used. Heavy metal ions such as magnesium ions, cadmium ions, lead ions, zirconium ions, etc. may also be added to the aggregated gelatin agent.

Removal of dissolved substances (desalting) may be repeated once or several times. When repeating several times, the flocculated gelatin agent may be added each time the removal is performed, or the flocculated gelatin agent may be added only at the beginning.

Next, in the present invention, as the agglomerated polymer agent, the above-mentioned formula (
A case where a polymer compound represented by If) is used will be explained. This polymer compound preferably has a molecular weight of 103 to 106, more preferably 3 x 103 to 2
10', and the amount added is preferably 1150 to 1/4, more preferably l/40 to l/10 in weight ratio to the protective colloid (preferably gelatin) contained in the emulsion.
It is. The method of use is similar to that for the agglomerated gelatin agent.

Specific examples of the polymer compound represented by formula (II) will be listed below, but the invention is not limited thereto.

- Exemplary polymer compound represented by formula (II) H ONH, NH.

P-9 p-t.

The above-mentioned polymer compound is described in, for example, Industrial Chemistry Magazine, Vol. 60,
1004 (1957).

The emulsion according to the present invention is prepared by preparing an emulsion containing seed crystals,
It may be obtained by growing particles from seed crystals or without using seed crystals. When seed crystals are used, if the emulsion containing the seed crystals itself is an emulsion according to the present invention using a thioether compound and a coagulating polymer, all emulsions obtained from this emulsion fall under the emulsion according to the present invention. However, the seed crystal emulsion for obtaining the emulsion according to the present invention does not necessarily have to be the emulsion according to the present invention. Preferably, a seed crystal emulsion according to the present invention is used as a seed crystal, and an emulsion according to the present invention obtained by using the thioether compound and aggregating polymer agent according to the present invention is also used during grain growth from the seed crystal. be.

Although the silver halide composition of the emulsion according to the present invention is arbitrary,
In particular, silver iodobromide is preferably used. When silver iodobromide is used, the silver iodide content is not particularly limited, but the average silver iodide content in the entire silver halide grains is preferably 10 mol% or less, and 6 mol% or less. It is more preferable that the amount is 0.2 to 6 mol %.

In this case, it is desirable that the silver iodide be concentrated inside.

Preferred silver halide grains contained in the emulsion of the present invention include silver halide grains having a multilayer structure and tabular grains.

Tabular grains can be obtained by adding certain agents, such as thioethers, during grain growth.

Regarding tabular grains, for example, JP-A-58-11392
No. 7, No. 58-113928 and JP-A-59
-Pages 252-253 of Publication No. 105636, 60-
This is disclosed in Japanese Patent No. 147727.

Here, the particles having a multilayer structure are particles in which a coating layer having an arbitrary halogen composition is provided on the outside of an inner core, and include so-called core/shell plastic particles. There may be only one covering layer, or two or more layers, for example three or four layers, may be stacked. Preferably the number of layers is 5 or less.

As the silver halide for the inner core and coating layer, silver bromide, silver iodobromide, and silver iodide are preferably used, but a mixture with a small amount of silver chloride (specifically, preferably 10 mol of silver chloride) is used. % or less, more preferably 5 mol% or less).

Preferably, silver iodobromide grains having layers formed by different silver iodide contents are used.

Further, the outermost layer is preferably substantially silver bromide or substantially silver iodobromide (silver iodide content 10% or less), and several percent
It may contain less than chlorine atoms.

The emulsion according to the present invention is prepared by adding a water-soluble silver salt solution and a water-soluble halide solution to a solution containing a protective colloid in which a thioether compound is present to form silver halide grains. In this case, as a forming means, for example, a simultaneous mixing method, a double jet method, a Chondrald double jet method, a triple jet method, a forward mixing method, a back mixing method, etc. can be used.

The grain size of silver halide grains is not particularly limited, but
Those having an average particle size of 0.1 to 3 μl are preferable.

More preferably, it is 0.3 to 2 μm.

The emulsion according to the present invention can effectively exhibit the effects of the present invention whether it is a monodisperse emulsion or a polydisperse emulsion.

The emulsion according to the invention can be chemically sensitized.

In addition, the emulsion according to the present invention and other emulsions used to constitute the light-sensitive material of the present invention may contain appropriate additives, if necessary.

That is, the photosensitive material embodying the present invention may contain any additives, which are described in Research Disclosure Vol. 176, No. 17643 (December 1978) and Vol. 187, No. 18716 (December 1978). 197
(November 2006), and the relevant sections are summarized in the table below.

Further, photographic additives that can be used in the preparation of emulsions in carrying out the present invention are also described in the above two Research Disclosures. If necessary, through a subbing layer, intermediate layer, etc., baryta paper, polyethylene-coated paper, polypropylene synthetic paper, glass paper, cellulose acetate, cellulose nitrate, polyvinyl acecool, polypropylene, polyester film such as polyethylene terephthalate, polystyrene, etc. It is constructed by coating on a support by a known method.

The silver halide photographic material according to the present invention may be either a black and white photographic material or a color photographic material, and may be a general purpose,
Although it is used for various purposes such as printing, X-ray, and radiation, it is especially effective as a high-sensitivity silver iodobromide photographic light-sensitive material.

The silver halide photographic material according to the present invention may be subjected to short-time or flash exposure in addition to ordinary exposure, and can be photographically processed by ordinary methods.

The silver halide photographic material of the present invention has remarkable effects in ultra-rapid processing. Here, ultra-quick processing as used in this specification refers to inserting the leading edge of the film into an automatic developing machine, passing through a developing tank, a transfer section, a fixing tank, a transfer section, a washing tank, a transfer section, and a drying section. The total time until the leading edge of the film emerges from the drying section [in other words, the quotient (see, ) of the total length of the processing line (s+) divided by the line conveyance speed (m/see, )) is 20 seconds to This refers to a process that takes 60 seconds.

In the silver halide photographic material of the present invention, good results are obtained when the processing time is 3 minutes and 30 seconds or less, and even better results are obtained when the processing time is 90 seconds or less.

〔Example〕

Examples of the present invention will be described in detail below. It should be noted that, as a matter of course, the present invention is not limited to the examples described below.

(i) Preparation of emulsions Seed crystals T-1, T-2, T-3 and T-4 were prepared as follows.

(A) Preparation of seed crystals T-1 and T-2 Silver iodide 2 with an average grain size of 0.3μ was prepared by the double jet method at 60°C, while controlling pAg-8.0 and pH = 2.0. Monodisperse cubic grains of silver iodobromide containing mol % were prepared. The reaction solution containing the obtained particles was divided into two parts, each was desalted as shown below, and two types of seed crystals T-
1, T-2 was obtained.

(B) Preparation of seed crystals T-3 and T-4 Add the above thioether exemplified compound (2) to the gelatin solution.
(0.05g/AgX1 mol) Total addition L, above tJ
They were prepared in the same manner as in the R production method, and desalted as shown below to obtain two types of seed crystals T-3 and T-4.

Desalting method for T-1 and T-3: Add a condensate of sodium naphthalene sulfonate and formalin to the mixed reaction solution at 40°C and add sulfuric acid magnezol.
7 MuMg5O, each 15g/AgX 1
mol, 60 g/1 mol of AgX was added and stirred for 3 minutes. After that, it is left to stand and excess salt is removed by decantation. After that, 40℃ pure water 2.14/AgX 1%
After adding and dispersing MgSO4, add 30g/A
After adding 1 mol of gX and stirring for 3 minutes, the mixture was allowed to stand and decanted.

Thereafter, post-gelatin was added, kept at 55°C, and stirred for 20 minutes to redisperse to obtain T-1 and T-3.

Desalting method for T-2 and T-4: Add 38g of 60% benzoyl-modified gelatin as a flocculating polymer agent to the mixed reaction solution at 40°C,
The mixture was stirred for a minute. Then, potassium hydroxide KOHO, 13g
/ Add 1 mol of AgX, adjust the pH to 4.0, let stand, and decant. After that, pure water at 40℃ 2.
After adding the IQ/AgX 1-T-ru, the KOH was added to 0.
Add 25g/1 mole of AgX and adjust the pH to 5.8.
Stir for a minute. Thereafter, 1.5 cc/1 mol of AgX was added to the mixture, and the mixture was left to stand still and decanted. After that, add 0.2 g of cerant KOH/AgX l mol, pH 5,
8 and redispersed to obtain T-2 and T-4. Seed crystal emulsion T
Since Emulsion-4 is an emulsion according to the present invention, the emulsion obtained therefrom is an emulsion according to Invention 1.

Using the above-mentioned T-1, T-2, 7-3, and T-4 seed crystals,
It was grown using two methods (a) and (b) as shown below.

Growth method (a): Using the seed crystal of T-1 above, particles were grown as follows. First, the seed crystals T to 1 are dispersed in a solution 8.5Q (corresponding to a solution containing a protective colloid) containing protected gelatin and, if necessary, ammonia, kept at 40°C, and then pn with acetic acid. was prepared.

Using this solution as a mother liquid, a 3.2N ammoniacal silver ion aqueous solution was added as a water-soluble silver salt solution by a double jet method. In this case, the pH and EAg were changed as needed depending on the silver iodide content and crystal habit. That is, pAg is 7.3.
The pH was controlled at 9.7 to form a layer containing 35 mol % of silver iodide. Next, the pH was changed from 9 to 8 to reach 95% of the particle size, and the pAg was kept at 9.0 for growth.

After that, a potassium bromide solution was added as a water-soluble halide solution through a nozzle over 8 minutes to lower the pAg to 11.0.
Mixing was completed 3 minutes after the addition of potassium bromide was completed. The pH was then lowered to 6.0 with acetic acid. This emulsion has an average grain size of 0
．． The silver iodide content of the grains as a whole was about 2 mol %, and the grains were monodispersed. Seed crystals T72°T-3 and T-4 were grown in the same manner.

Growth method (b): Using the above-mentioned T-1 seed crystal, particles were grown as follows. First, protected gelatin kept at 40°C and the thioether exemplified compound (2) O-05g/AgX
8.5Q solution containing 1 mol and optionally ammonia
(corresponding to a solution containing a protective colloid), this seed crystal T-1
was dispersed, and the pH was further adjusted with acetic acid. Using this solution as a mother liquid, a 3.2N ammoniacal silver ion aqueous solution was added as a water-soluble silver salt solution by a double jet method. In this case, pi (and EAg were changed as needed depending on the silver iodide content and crystal habit. That is, pAg was 7.3, pH
was controlled to 9.7 to form a layer with a silver iodide content of 35 mol%. Next, the pH was changed from 9 to 8 to reach 95% of the particle size, and the pAg was kept at 9.0 for growth. Thereafter, a potassium bromide solution was added as a water-soluble halide solution using a nozzle over a period of 8 minutes to reduce the pAg to 11.0, and the mixing was completed 3 minutes after the addition of potassium bromide was completed. The pH was then lowered to 6.0 with acetic acid. This emulsion had monodispersed grains with an average grain size of 0.53 μm and a silver iodide content of about 2 mol % in the entire grains. Seed crystals T-2, T-3, and T-4 were grown in the same manner.

Next, the reaction solution of T-1 of growth method (a) is divided into two parts, and excess soluble salts are removed (dissolved (corresponding to removal) was carried out.

Desalting method (a): 1. Add 5.58% of the condensate of sodium naphthalene sulfonate and formalin (corresponding to the comparative compound for the flocculating polymer agent used in the present invention) to the mixed reaction solution at 40°C. 1 mole of AgX, 8.5 g of MgSO4
/ Add 1 mole of AgX, stir for 3 minutes, leave to stand, and decant.

Add 1.8Q/AgX l mol of 2.40'C pure water, disperse and set, then add 20g/AgX of Mg5Oa.
After adding 1 mol and stirring for 3 minutes, let stand and decant.

3. Repeat step 2 above one more time.

4. Add 15g of post-gelatin/Agx1 malt water, 4.
After finishing to 50cc/AgX1 mole, heat at 55°C for 20
Stir for 1 minute to disperse.

In this way, emulsion 1-1 was obtained.

Desalting method (b): ■ Add 50 g/Ag of 60% benzoyl-modified gelatin as a flocculating polymer agent to the mixed reaction solution at 40°C.
X1 mol was added, then 56 wt% acetic acid (HAC) was added to 110μ0. /Agx1AgX1molH5. (H:
N, let stand, and decant.

2. Add 1.8Q/AgX l mol of pure water at 40°C, then add KOH6.8g/AgX l mol, I)
Set H to 6.0 and disperse. After well dispersing, 5f
Add 70cc of iwt% HAC/1 mole of AgX and adjust the pH.
to 4.5, let stand, and decant.

3. Repeat step 2 above once again.

4. After that, 715 g of after gelatin/AgX l mol K
Add OHl g/AgX and water, 450cc/Ag
Finish to 1 mole of X.

In this way, emulsion 1-2 was obtained.

Similarly, the reaction solution of T-1 in the growth method (b) was divided into two parts, and emulsions 1-3.1-4 were obtained respectively by the two desalting methods (a) and (b) described above. .

The reaction solutions of T-2, T-3, and T-4 were also treated in the same manner as T-1 to obtain 1-5 to 1-16.

(C) Preparation of emulsion 1-17.1-18.1-19.1-20 by preparation of monodisperse grains without using seed crystals. %pH
A halogen salt aqueous solution and a silver salt aqueous solution were added by the Chondrald double jet method under conditions where the particle size was 2.0 to obtain particles with an average grain size of 0.53 μm and an average silver iodide content of 2 mol %. . These grain-containing emulsions were desalted using two methods in the same manner as the seed crystals to obtain emulsions 1-17 and 1-18.

In addition, the thioether exemplified compound (2) (0.05g
/AgX1 mol) was carried out in the same manner as described above, and desalted by two methods to obtain emulsions 1-19 (comparative emulsion),
Emulsion 1-20 (emulsion according to the present invention) was obtained.

(D) Preparation of polydisperse emulsion The following four solutions were prepared using the mixing method.

Solution B and solution C were poured into a reaction vessel for emulsion preparation and stirred with a propeller type stirrer at a rotation speed of 300 revolutions/minute, and the reaction temperature was maintained at 55°C.

Next, the liquid A was divided into 1 volume = 2 volumes, and 1 volume, 100 m12 of which, was added over 1 minute.

After continuing stirring for 10 minutes, the remaining 2 volumes of Solution A, 20
0a<l was added over 10 minutes. Stirring was continued for an additional 30 minutes. Then, D coffin was added to adjust the pH of the solution in the reaction vessel to 640, and the reaction was stopped.

The average grain size of the silver halide grains was 0.56 μI, and the degree of dispersion was 0.32. Further, the silver iodide content was 1.2 mol%.

Thereafter, desalting was carried out using two desalting methods (a) and (q) to obtain emulsion 1-21 (comparative emulsion) and emulsion 1-22 (comparative emulsion), respectively.

(0.05 g/1 mol of Ag An emulsion according to the invention) was obtained.

(E) Preparation of tabular grains 5 g of KBrlO, 10 cc of the 0.5 wt % aqueous solution of the above-mentioned thio-ester exemplified compound (2), and 30 g of gelatin were added and dissolved in water la, and the mixture was maintained at 70°C. Add 0.88 mol/123 silver nitrate aqueous solution to this solution while stirring.
0+m12, potassium iodide and potassium bromide (molar ratio 3
．． 5: 96.5) aqueous solution 0.88 mol/Q30r
aQ was added by double jet method, and the average particle size was 0.
Grains with a silver iodide content of 3.5 mol % were obtained in a 60μ grain size.

After the addition of the mixed solution was completed, the temperature was lowered to 40°C. After that 2
24. Divide, and one part contains a condensate of sodium naphthalene sulfonate and formalin and MgSO4.
6g/AgX 1% was added, the pH was lowered to 4.0 and desalted, and then 15g/AgX was added after gelatin.
1 mol was added to prepare emulsion 1-25 (comparative emulsion). Further, one of the emulsions was desalted by steps 1 and 4 of the desalting method (b) to obtain emulsion 1-26 (emulsion according to the present invention).

(n) Preparation and evaluation of samples (u-1) Preparation of samples The 26 types of emulsions obtained in (i) above were chemically sensitized. That is, ammonium thiocyanate, chloroauric acid, and hypo were added to perform gold-sulfur sensitization.

After this chemical sensitization, 4-hydroxy-6-methyl-1
,3,3a,7-chitrazaindene was added. after that,
Potassium iodide 15011%/AgX 1 mol and the following spectral sensitizing dyes ① and ②, 300a+g, respectively, 15
+g/1 mol of AgX was added to perform spectral sensitization.

Spectral sensitizing dye■ Spectral sensitizing dye■ The coating emulsion thus obtained and the coating solution for protective layer are applied to both sides of the subbed polyester film support.
Two layers were coated at the same time in the order of the silver halide emulsion layer and the protective layer from the support side. Thereafter, it was dried to produce a silver halide photographic film.

The following additives were added to the emulsion layer per mole of silver halide.

t-Butylcatechol 400mg Polyvinylpyrrolidone (molecular weight 10.000) 1.0
g Styrene-maleic anhydride strict copolymer 2.5g trimethylolpropane 10g diethylene glycol 5&nitrophenyl-triphenyl-7male 7onium chloride F 50 Fl
g1.3-dihydroxybenzene-4-ammonium sulfonate 2-mercaptobenzimidazole-5-sulfonate sodium g 1511g So, Na c, F+s-low CH, CH, O crown H2C1 (,002m
g C, F, ? SO, g 1,1-dimethylol-1 to bromo-1-nitromethane 10 mg Also, the following compound was added to the protective layer for gelatin Ig.

Polymethyl methacrylate (matting agent) with an average particle size of 5μI 71mg
Colloidal silica (average particle size 0.13μm) 70
mg (CHO) z aqueous solution 40%
1.5m<1)ICHO35%
2taQ2.4-Dichloro-6-hydroxy-1,3,5-1-riazine sodium salt aqueous solution 2% 10mff The following was used as the subtraction liquid.

A copolymer consisting of three types of monomers: 50 wt% glycidyl methacrylate, 1 Qwt% methyl methacrylate, and 40 wt% butyl methacrylate, was added at a concentration of 10 wt%.
diluted to t% to obtain a copolymer aqueous dispersion,
This was used as the subtraction liquid.

Also, the amount of gelatin in the undeveloped film at this time was 3.1 Og/m'' per side.In this way, emulsion 1-1-1-26 corresponded to samples 2-1 to 2-2. 26 (see Table 1).

(ii-2) Evaluation of Sample (Processing and Measurement of Sample) The following measurements and evaluations were carried out for sample l.

Sensitometric measurement: Use the standard light B described on page 39 of “New Edition: Lighting Data Book” (edited by the Illuminating Society of Japan, 1st edition, 2nd printing) as a light source,
All samples 2-1 to 2-10 shown in Table 1 were processed for 0.0 g light time.
A so-called white exposure was performed for 1 second at 3.2 CMS without a filter. Here, this exposure was performed from both sides of the film so that both sides of the film received the same amount of light. The above sample is KX-800 manufactured by Konica Corporation.
Using an automatic processor, use XD-90 processing solution for 3 minutes and 30 minutes.
Development was performed at 32°C for second processing, 35°C for 90 second processing, and 37°C for 145 second processing, and the sensitivity and fog of each sample were determined.

The sensitivity was obtained by calculating the reciprocal of the amount of light required to increase the deterioration density by 1.0 due to exposure. However, in Table 1, the sensitivity is expressed as a relative sensitivity with the sensitivity of sample 2-1 set as 100.

As a method for evaluating pressure resistance, each sample was heated at 25°C for about 12 hours.
It was kept at a constant temperature and humidity with a relative humidity of 50%, and was bent about 280 degrees with a radius of curvature of 2 co+ under these conditions.

Three minutes after bending, exposure was performed using an optical wedge and development was performed. Measure the blackening density of each wedge of this sample, take the density difference between the desensitized part caused by bending and the part that was not bent as 80, divide ΔD by each density, and calculate the average value ΔD/D. was calculated, and this value was used as a guideline for pressure desensitization.

In other words, the smaller this value is, the better the pressure desensitization resistance is.

The compositions of the developer and fixer used in the processing are as shown below.

developer potassium sulfite Hydroxyethylethylene di Sodium amine triacetate 1.4-dihydroxybenzene boric acid 5-methylbenzimidazole l-7enilme 5-mercapto Tetrazole Sodium metabisulfite Acetic acid (90%) diethylene glycol ■-Phenyl-3-pyrazolidone 5-nitroindazole 68.75g g 7g 0g 0.035g 0.015g 5.0g 12.8g 16.0g 1.2g 0.14g shall be.

Fixer ammonium thiosulfate sodium sulfite sodium acetate aluminum sulfate 10 ~ 18 water! Sulfuric acid (50wt%) 40g 7.3g 15.5g 27.7g 6.0g Glutaraldehyde 3.08g Potassium bromide 4.0g 5-Methylbenzotriazole 0.05g Make an IQ aqueous solution and add potassium hydroxide to pu = 10.40 Table It was found that all the samples of the present invention from Sample No. 1 had low fog, high sensitivity, good ΔD/D characteristics, and improved pressure desensitization.

Note that similar results were obtained when the exemplified compounds (3), (4), and (5) were used instead of exemplified compound (2) as the thioether compound.

〔Effect of the invention〕

The silver halide photographic material of the present invention has high sensitivity, low fog, and excellent pressure resistance.

In particular, the shorter the treatment time, the more remarkable the effect.

Claims (1)

[Claims] In a silver halide photographic material having at least one silver halide emulsion layer on at least one side of a support, the silver halide emulsion layer is water-soluble in a solution containing a protective colloid in which a thioether compound is present. It is characterized by containing a silver halide emulsion obtained by agglomerating silver halide grains produced by adding a silver salt solution and a water-soluble halide solution together with a protective colloid using an aggregating polymer agent, and removing dissolved substances. A silver halide photographic light-sensitive material.