JPS6011343B2 - silver halide photographic emulsion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a silver halide photographic emulsion, and more particularly to a sulfur-sensitized silver halide photographic emulsion that has high sensitivity, high gradation, and low fog. .

In order to increase the sensitivity of silver halide photographic emulsions, for example, the silver halide grain size is increased or chemical sensitization methods are devised, but in general, these high sensitivities are In addition to lowering gradation and increasing fog, when the silver halide grain size is increased, it also has the disadvantage of lowering the graininess and sharpness of the photographic light-sensitive material.

Therefore, one of the major themes was the development of silver halide photographic emulsions having the contradictory photographic properties of high sensitivity, high gradation, and low fog. Tokkoku Sho 51-36130 proposed a method of sensitizing a specific sulfur-sensitized silver halide photographic emulsion by adding a specific heterocyclic compound having a mercapto group. 51-7722
No. 3 proposes a technique for sensitizing a sulfur-sensitized silver halide photographic emulsion having an average grain size of not more than 0.5 mm by incorporating a hydroxytetraazaindene compound therein. However, although these techniques can produce silver halide photographic emulsions with high sensitivity and low fog, they cannot increase the gradation, and may even decrease it. etc. are restricted. An object of the present invention is to provide a silver halide photographic emulsion with high sensitivity, high gradation, and low fog.

Other objects and features of the present invention will be naturally understood from the following description. The origin of the present invention lies in research into silver halide photographic emulsions using synthetic polymers.

In other words, gelatin is mainly used as a binder in ordinary silver halide photographic emulsions, but gelatin is often mixed with natural and artificial substances, such as substances that inhibit or accelerate physical ripening or chemical ripening. ,
Research on silver halide photographic emulsions would be too complicated, so using synthetic polymers instead of gelatin would
Since it does not contain the above-mentioned impurities, it is possible to clearly understand the effects of various photographically effective substances of known origin added to the emulsion, making it ideal for research on the ripening process. During chemical ripening, chemical ripening is usually controlled by combining a sulfur sensitizer with a chemical ripening inhibitor, but attempts to suppress fog as much as possible often result in insufficient sensitivity and gradation. .

According to the research conducted by the present inventors, when a certain type of compound is roughly combined with a sulfur sensitizer and subjected to chemical ripening, sulfur sensitization is strengthened and the object of the present invention, which is high sensitivity, high gradation, and low fog, is achieved. It has been found that a silver halide photographic emulsion can be obtained. The object of the present invention is to use a heterocyclic compound (having a fused benzene ring or a fused naphthalene ring) containing at least one nitrogen atom as a sulfur sensitization enhancer, which has a thione group that does not undergo henolization next to the nitrogen atom. This can be achieved by sulfur sensitizing a silver halide photographic emulsion by combining a compound containing a sulfur sensitizer in a specific ratio.

Compounds having a thione group that does not undergo phenolization are partially shown as capri inhibitors in Tokokukan Sho 50-43923, but in the present invention, the action as a reinforcing agent for sulfur sensitization has been newly discovered. , which is fundamentally different from its use as a mere inhibitor.

Depending on the type of these compounds, some exhibit no inhibitory effect at all, or their effect is extremely weak, so in this case, it is rather necessary to use them in combination with other well-known chemical ripening inhibitors. However, when the present invention is applied to gelatin emulsions, natural inhibitors are often present in gelatin, so if an appropriate gelatin is selected, no inhibitor may be required. The compound having a thione group that is not phenolated and used in the present invention includes a compound represented by the following general formula (1).

General Formula (1) In General Formula (1), Z represents a fused benzene ring or a fused naphthalene ring.

Y represents oxygen, sulfur, selenium, =N-R2 or vinegar.

In Shigeru, R, R2 are alkyl groups, substituted alkyl groups (e.g. hydroxyethyl, trifluoromethyl, chloromethyl,
trifluoromethyl, chloromethyl, sulfoalkyl, carboxyalkyl, etc.), alkylsulfonyl group, alkylsulfamoyl group, alkylcarbamoyl group, allyl group, aryl group (e.g. phenyl, tolyl, methoxyphenyl, chlorophenyl, 3. 4-methylenedioxyphenyl, etc., aralkyl group, alkoxycarbonyl group (
For example, methoxycarbonyl, ethoxycarbonyl, butoxycarbonyl, octoxycarbonyl, etc.), acetoxy group, acetoxyalkyl group, alkoxy group, hydroxy group, oxo group, penzoIJden group, alkylthio group (e.g. methylthio, ethylthio, etc.), cyano represents a monovalent substituent such as a group or a halogen atom. Further, the condensed ring represented by Z may have the substituents described for R, and R2. R3 and R4 represent an alkyl group. Some specific examples are listed below, but the present invention is of course not limited to these. 1 3-Methyl-benzothiazoline-2-thione 2 3-ethyl-penzothiazoline-2-thione 3 3-butyl-benzothiazoline-2-thione 4
3-benzyrubenzothiazoline-2-thione 5 3
・6-diethyl-penzothiazoline-2-thione 6 3
-Methyl-6-methoxy-penzothiazoline-2-thione 7 3-octyl-penzothiazoline-2-thione 8 3-sulfopropyl-penzothiazoline-2-thione 9 3-methyl-benzoselenazoline-2-thione 1
0 3,6-dimethyl-penzoselenazoline-2-thione 11 1,3-dimethyl-pendzimidazoline-2-thione 12 1,3-dibutyl-benzimidazoline-
2-thione 13 1,3-didecylbenzimidazoline-2-thione 14 1,3-dibenzyl-penzimidazoline-2-thione 15 1,3-dibenzyl-5-
Methyl-penduimidazoline-2-thione 161,3-diethyl-penduimidazoline-2-thione 17 1.
3-dimethyl-6-ethoxy-penduimidazoline-2
-thione 18 3-ethyl-pendimidazoline-2-thione i9 3-propyl-penzoxazoline-2-thione 20 3-methyl-6-ethylbenzoxazoline-2-thione 21 3-methyl-5-methoxycarbonyl-penzoxazoline-2-thione 22 3-sulfopropyl-5-chlorobenzoxazoline-2-
Thione 23 3-ethyl-8-naphthothiazoline-2-thione 24 3-ethyl-Q naphthothiazoline-2-thione 25 1,3-dimethyl-8-naphthoimidazoline-2-thione 26 1,3-carboxymethyl-8-naphthoimidazoline-2- Thione 27 3-methyl-8
・8'-Naphthoxazoline-2-thione 28 3-sulfopropyl-8naphthoxazoline-2-thione A compound having a thione group as shown in the above general formula (1) is miscible with water or water such as methanol. It is necessary to dissolve it in an organic solvent and add it to the silver halide emulsion together with a sulfur sensitizer during chemical ripening.

The amount added is usually within the range used in the photographic industry, ie from about 1 x 10-5 to about 1 x 1 per mole of silver halide.
Although it is possible in the range of 0 to 1 mole, the important finding of the present invention lies in the ratio with the sulfur sensitizer, which is about 4 times to about 100 times (molar ratio) to the sulfur sensitizer. It is necessary to use amounts that are greater than the amount ranges normally used as antifoggants. This is a major feature of the present invention, for example,
There are two compounds of the general formula (1), known in some cases, that exhibit only an excellent antifogging effect even when added in the usual amount after chemical ripening, such as It is predicted that a silver halide photographic emulsion with high sensitivity (sensitization), high gradation, and low fog, which is the object of the present invention, can be obtained by sulfur sensitization with the addition of a chemical ripening inhibitor in a balanced manner. This was impossible and was surprising. Various known sulfur sensitizers can be used as the sulfur sensitizer used in the present invention, such as thiosulfate, allylthiocarbamide, thiourea, allylisothiocyanate, cystine, P-toluenethiosulfonate, and polysulfur sensitizer. Rufaids, etc. U.S. Patent No. 1574944, U.S. Patent No. 227
No. 8947, No. 2410689, No. 244020
No. 6, No. 3187458, No. 3415649,
No. 3501313, French Patent No. 2059245
Compounds described in No. 1, etc. are used.

The amount of these sulfur sensitizers added varies depending on various conditions, such as the type and size of silver halide used, feed during chemical ripening, silver potential, temperature and time, but as a guide, silver halide 1 An amount sufficient to effectively increase the sensitivity of the emulsion may be determined in the range of about 10-5 mol to 10-1 mol per mol, taking into account the ratio to the compound of general formula (1). The sulfur sensitizer can be added in the form of water or an organic solution miscible with water according to a conventional method. It is also possible to provide some, or sometimes all, of the sulfur sensitizer from chemically active gelatin. Sulfur sensitizer, general formula (1
) can be added all at once or separately, but it is preferable to add the compound of general formula (1) at least before sulfur sensitization is completed. Alternatively, it may be added in advance during physical ripening. Along with sulfur sensitization, U.S. Patent Nos. 2,448,060 and 2,540,086
It is possible to use a combination of sensitization methods using salts of known noble metals (for example, gold, platinum, palladium, iridium, rhodium, ruthenium, etc.) described in No. 2,566,245, and 2,566,263. Also, instead of or in conjunction with sulfur sensitization, U.S. Pat.
It is also possible to use the selenium sensitization method described in No. 7446. Furthermore, known sensitization methods such as reduction sensitization, silver chloride sensitization as described in Tokoseki Sho 51-1116, or silver sensitization can be used in combination with the sulfur sensitization method.

Various silver halides can be used in the silver halide photographic emulsion of the present invention.

Examples include silver chloride, silver bromide, silver chlorobromide, silver iodobromide, and silver chloroiodobromide. The crystal form and grain size of the silver halide grains are not limited. Further, the crystal structure of the halogenated radiation particles may be uniform or may have a layered structure with different inside and outside. Furthermore, the latent image may be formed mainly on the surface of the particles or inside the particles. Silver halide emulsions can be prepared using known methods such as single jet method, double jet method, and US Pat.
It can be produced by various methods such as halogen conversion method such as No. 622318.

In this case, it has long been known to add a water-soluble rhodium compound for the purpose of increasing contrast. When the silver halide emulsion of the present invention is prepared using this rhodium compound, the high contrast of the rhodium compound is additively amplified by the use of the compound of general formula (1), and the maximum It was found that it also has the advantage of being able to compensate for the desensitizing effect, which is a disadvantage. All hydrophilic colloids commonly used in photographic emulsions can be used as binders for silver halide emulsions.

Useful binders include gelatin, gelatin derivatives, colloidal albumin, casein, cellulose derivatives, agar, sodium alginate, polyvinyl alcohol, polyN-vinylpyrrolidone, acrylic acid polymers, acrylamide polymers, and the like. These may be used in combination of two or more types, if necessary. Although gelatin is advantageously used in the present invention, gelatin may be either inert or active against chemical ripening, and some or all of the gelatin may be replaced by synthetic polymers.

Moreover, the amount used is not limited to silver halide and can be used in any ratio. It is possible to add various photographic additives to the silver halide photographic emulsion of the present invention without losing the effects of the present invention. For example, optical sensitizers that can be used include cyanines, merocyanines, trinuclear or tetranuclear merocyanines, trinuclear or tetranuclear cyanines, styryls, holopolar cyanines, hemicyanines, oxonols and hemioxonols. These optical sensitizers include a nitrogen-containing heterocyclic nucleus as part of their structure, a basic nucleus such as thiazoline, thiazole, oxazoline, oxazole, pyrroline, pyridine, imidazole, selenazole, or rhodanine, thiohydantoin. , oxazolidinedione, barbituric acid, thiobarbituric acid, vilazolone and the like are preferred.

Such a nucleus may have various substituents, and it is also possible to have a condensed carbon ring or a rear ring. Other optional antifoggants or stabilizers include azaindenes, thiazolium salts, sulfocatecols,
Known compounds such as urazoles, oximes, nitrones, nitroindazoles, mercaptotetrazoles, polycarboxylic acids, and polyoxyaryl compounds can be used without limitation.

Conventionally, in order to prevent the photographic properties (sensitivity, gradation, fog, etc.) of silver halide photographic materials from changing during storage, the above-mentioned compounds have been added to silver halide emulsions that have been chemically ripened. It is common for various stabilizers to be added.

However, it is well known to those skilled in the art that these stabilizers have the effect of reducing photographic sensitivity. Furthermore, it is known from experience that few of these stabilizers have a sufficiently satisfactory storage stabilizing effect. The silver halide photographic emulsion of the present invention has high sensitivity, high gradation, and low fog I.
In addition to having the excellent photographic properties of J, it also has the characteristics of providing excellent storage stability.

This is considered to be because the compound of general formula (1) used in the present invention not only effectively promotes sulfur sensitization, but also exhibits the conventionally known fog suppressing effect.

However, depending on the type of compound of general formula (1),
Since there are some compounds whose antifogging effect is smaller than their sensitizing and contrast-enhancing effects, it may be necessary to further use a chemical ripening inhibitor other than the compound of formula (1). As this chemical ripening inhibitor, for example, a nucleic acid or its base (
For example, 2,4-dioxypyridine, 5-methyl-2,
4-dioxypyrimidine, 2-oxy-4-aminopyrimidine, 6-aminopurine, 2-amino-6-oxypurine, etc.), double ring compounds having a mercapto group, hydroxytetraazaindenes, other heterocyclic compounds, cystine, cysteine, There are many compounds such as vitamin B. The chemical ripening inhibitor can also be obtained from the gelatin used depending on the type and amount of gelatin.

The silver halide photographic emulsion of the present invention includes, for example, aldehydes, ethyleneimines, epoxies, sulfonyl chlorides, vinyl sulfones, isocyanates, carbodiimides, activated olefins, aziridines, inorganic hardeners (e.g. Organic and inorganic hardeners such as chrome alum, etc.) may be included. Further, it is useful to use the silver halide photographic emulsion of the present invention for color photography, and in this case cyan, magenta and yellow coloring agents may be included. These color formers include phenols, 5-pyrazolones, ketomethylene compounds, and various color formers such as active point substitution type color formers (2-equivalent couplers), colored color formers, and development inhibitor release type color formers (Dm couplers). There is a drug,
One or more types of these may be used. Furthermore, it is preferable to add a surfactant to the silver halide photographic emulsion of the present invention.

Examples include saponin, alkylaryl sulfonates, higher alkyl sulfonates, higher alkyl sulfates, quaternary ammonium salts, polyhydric carboxylic acids, and the like. Other photographic additives include gelatin plasticizers, ultraviolet absorbers, sleeve adjustment agents, toning agents, antioxidants, antistatic agents, thickeners, graininess improvers, dyes, mordants,
It is optional to use brighteners, development speed regulators, matting agents, and the like.

The silver halide photographic emulsion of the present invention can be coated and dried on various supports such as various films, baryta paper, and polyethylene laminated paper to produce various photographic materials.

The photosensitive material can exhibit its effects in any development process. The present invention will be described below with reference to Examples, but the present invention is not limited thereto.

Example 1 After physically ripening a silver iodobromide gelatin emulsion (inert gelatin) containing 2 mol% silver iodide, it was washed with water by a conventional method to obtain small cowhide gelatin with low sulfur-containing sensitization and suppressed magnification. Chemical ripening was performed by adding a small amount of inert gelatin.

As a sulfur sensitizer per mole of silver halide/IPO (N
a2S203・9 also 0) and the exemplified compound of general formula (1) shown in Table 1 were added, and the pH was 6.5 and 40 to 55 qo.
Aged for 80 minutes. Next, 4-hydroxy-6-methyl 1.3 powder, 7-tetraazaindene, saponin, and formalin were added to each of these emulsions after sulfur sensitization.
Further, the pH was adjusted to 5.5, and the mixture was coated on a cellulose triacetate film support and dried. Each magazine material was exposed with a sensitometer, then developed with sand at 20°C9 using D-72 imaging solution, fixed in the usual manner, and washed with water. Sensitometry was performed on the samples to measure sensitivity, gradation, and fog. did. The results are shown in Table 1.

Regarding the same sensitization prescription, only the samples with the maximum sensitivity within the above aging time range of 40 to 8 vessels are shown, and the sensitivity of sample number 1 is 1.
The relative sensitivity is expressed as 00.

Table-1 Sulfur component and general formula (1) of Hypo in Table-1
The ratio of use to the compound is about 1:50 (weight ratio).

Example 2 A silver chlorobromide emulsion (silver bromide 50 mol %) with an average particle size of 0.4 mm was prepared using inert gelatin.

After adding inert gelatin to this emulsion and adjusting the pH to 5.5 for chemical ripening, the additives shown in Table 2 were added. Aged at 55°C for 30-90 minutes. Thereafter, the same procedure as in Example 1 was performed except that mercaptobenzothiazole was used as a stabilizer, and the results shown in Table 2 were obtained.
Sample number 12 was used for comparison (sensitivity 100). Table 2 In addition, Samples 12, 14, 1, 1 & 19, and these 5 samples, Samples 12A, 14A, 15A, 18A without adding mercaptobenzothiazole as a stabilizer.
, 1 lotus of 1 and the stabilizer of sample 12 were combined into exemplified compound 11 (
Table 3 below shows a total of 11 types of samples, one wave of which was replaced with 9) of loo.
A storage test was conducted as shown in .

The results show that the samples of the present invention have good storage stability even without containing stabilizers. Table 3 Example 3 A silver bromide emulsion with an average grain size of 0.8 mm was prepared by the ammonia method using inert gelatin.

Add this emulsion to small cow skin gelatin and adenine (9 of 50).
After adjusting the pH to 6.2 for chemical ripening, Table-
Additives as shown in No. 4 were added and ripened at 55q0 for 40 to 8 females. Thereafter, Table 4 was prepared by the same operation as in Example 1.
The results were obtained. Sample number 21 was used for comparison. Table 4 Example 4 After chemical ripening of sample numbers 21 and 23 of Example 3, the following yellow coupler was emulsified in an aqueous gelatin solution containing sodium laurylbenzenesulfonate using ethyl acetate and dibutyl phthalate by a conventional method. Silver halide emulsions were prepared in the same manner as Samples 21 and 23 except that the dispersed material was added, and the emulsions were coated on polyethylene laminate paper and dried.

After exposing these samples to light, they were subjected to color development, bleach-fixing, and stabilization, and sensitometry was performed, and the same results as in Example 3 were obtained. Example 5 Tests on silver halide photographic emulsions using synthetic polymers are presented to further aid in understanding the invention.

Acrylamide: Diacent acrylamide: Acrylic acid: 2-methyl-1-vinylimidazole (65
A silver chlorobromide emulsion (silver bromide: 50 mol %) was prepared by a conventional single-jet method using a quaternary copolymer consisting of a molar ratio of :20:7:8.

Aging was at 65 qo for 40 minutes. Add polyvinyl alcohol (1 part) and styrene-maleic anhydride (
After adding a blend of isobutylene-maleic anhydride copolymer (0.05 part) to 0.25 part (0.25 part) copolymer and heating at 90°C for 30 minutes at pH±4, physical ripening was stopped. It was precipitated with zirconium nitrate and magnesium sulfate and washed with water. Thereafter, citric acid was added and the additives shown in Table 5 were added to the redissolved emulsion, and the pH was adjusted to 4.4 and the pH was adjusted to 7.
Aged at 0 and 65qC for 30 minutes. After that, according to the usual method,
Stabilizers, surfactants, etc. were added and coated on baryta paper and dried. Development processing and sensitometry were as in Example 1. The results are shown in Table-5. Sample number 30 was used for comparison.
Table 5 Sample 31 is an example outside the present invention.

Unlike Examples 1 to 4, in which the aging time was changed, when the chemical aging time was the same, the amount of the compound of general formula (1) relative to the sulfur sensitizer showed a maximum in sensitivity and gradation (Samples 31 to 3).
4) The inhibitory effect becomes stronger. In that case, it can be seen that the amount of Hibo should be increased (Samples 35 to 36).

Claims (1)

[Claims] 1. A sulfur sensitizer and a heterocyclic compound containing at least one nitrogen atom (having a fused benzene ring or a fused naphthalene ring), which has a thione group that is not enolized next to the nitrogen atom, and the thione A silver halide photographic emulsion which is chemically ripened by combining a compound having a group in an amount of about 4 to about 100 times (molar ratio) relative to a sulfur sensitizer.