JPH02250049A - Silver halide photographic material high in sensitivity - Google Patents

Abstract

PURPOSE:To enhance sensitivity and to reduce fluctuation of sensitivity by forming a silver halide emulsion layer obtained by adding a solution or dispersion containing a spectral sensitizing dyestuff and a hydrophilic polymer compound adjusted to a pH of 7.5-10.5. CONSTITUTION:The silver halide emulsion high in sensitivity is obtained by adding the solution or dispersion containing the spectral sensitizing dyestuff and the hydrophilic polymer, such as gelatin derivatives, a graft polymer of gelatin and another polymer, albumin, or casein, alone or in a mixture or copolymer of them, and the solution of dispersion of the dyestuff is adjusted to a pH of 7.5-10.5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a highly sensitive silver halide photographic light-sensitive material, and in particular, it suppresses a decrease in sensitivity due to storage of a spectral sensitizing dye solution and improves sensitivity. This invention relates to a silver halide photographic light-sensitive material.

[Background of the invention]

In recent years, with the development of photographic technology, there has been a strong desire for higher sensitivity of silver halide photographic materials. For example, high sensitivity that meets the needs of each field, such as faster camera shutters, faster processing of color and black and white photographic paper, electronics and simplification in the printing industry, and lower X-ray exposure doses in the medical field. It is

Taking the field of medical X-ray photography as an example, the conventional 45Qnm
From the regular type, which was sensitive to a wavelength range of 540 to 550 nm, orthotized photosensitive materials, which are orthogon-sensitized and sensitive to a wavelength range of 540 to 550 nm, are now being used. Those sensitized in this way have a wider wavelength range and higher sensitivity, and therefore can reduce the amount of X-rays that they are exposed to, and the effects on the human body and the like.

Various research and developments have been carried out on sensitizing technology for photographic emulsions, and many useful methods have been discovered.One of them is a technology using sensitizing dyes, so-called color sensitization. It is being

In general, the production of silver halide emulsions involves steps such as the formation of silver halide grains, physical ripening, desalting, and chemical sensitization. The conventional method is to add it to a photographic emulsion: first, after chemical sensitization and before coating, or before the start of chemical sensitization as described in U.S. Pat. No. 4,425,426; There is a technique that can be used in the middle of the process. Furthermore, secondly, U.S. Patent No. 2.735.766, U.S. Pat.
No. 8,960, No. 4,183.756, No. 4,225
, No. 666 specifications, JP-A-58-184142,
As described in publications such as No. 61-19628, No. 61-103149, and No. 61-205929, there is a technique of adding during particle formation (during physical ripening). Thirdly, as described in JP-A-61-103149 and JP-A-61-196238, the second half of particle growth, when the shape of the particles does not substantially change, and from after particle formation to before the desalination process. There is a technology to add it to

To add the dye, the dye is first dissolved in a suitable solvent such as evaporated methyl alcohol, ethyl alcohol, methyl cellosolve, acetone, water, pyridine, or a mixed solvent thereof, and then added to the emulsion in the form of a solution. There is a way.

Also, as described in U.S. Pat. No. 3,469,987, etc., a method in which a dye is dissolved in a volatile organic solvent, the solution is dispersed in a hydrophilic colloid, and this dispersion is added to an emulsion; A method of dispersing a water-insoluble dye in a water-soluble solvent without dissolving it and adding this dispersion to an emulsion, as described in Japanese Patent Publication No. 46-24185; U.S. Patent No. 3,8
22.135, a method in which a dye is dissolved in a surfactant and the solution is added to an emulsion; JP-A-51-7
A method of dissolving the dye using a red-shifting compound and adding the solution into an emulsion as described in JP-A-50-80826; A method of dissolving and adding the solution into an emulsion; as described in JP-A-60-196749, pH
There is a method in which a dye dispersion adjusted to 7.0 is added to an aqueous gelatin solution and the resulting dye dispersion is added to an emulsion.

However, when a dye is added to a silver halide emulsion by the above method, there is a drawback that sensitivity decreases or sensitivity variations occur if the dye solution or dispersion is prepared and stored for a certain period of time before use. Ta.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a silver halide photographic material with higher sensitivity without decreasing sensitivity even when a preserved dye solution or dispersion is used. Another object of the present invention is to provide a silver halide photographic light-sensitive material that exhibits small variations in sensitivity even when a preserved dye solution or dispersion is used.

[Means for solving problems]

The above object of the present invention is to provide particles with a pH of 7.5 to 1O, 5 in the particle formation step, physical ripening step and desalting step on the support.
No. 1, characterized in that it has at least one silver halide emulsion layer obtained by adding a solution or dispersion containing a spectral sensitizing dye and a hydrophilic polymer compound adjusted to
This can be achieved using a silver genide photographic material.

The present invention will be explained in more detail below.

In the present invention, a high-sensitivity silver halide emulsion is obtained by adding a spectral sensitizing dye to a silver halide emulsion. It is customary to prepare silver halide grains through the steps of forming silver halide grains by means such as metathesis of halides, physical ripening, desalting, and chemical sensitization. Formation process of silver oxide particles,
This is at least one of a physical ripening step and a desalting step.

The process of forming silver halide grains refers to the formation of silver halide grains through double decomposition of soluble silver salt and soluble halide, and the physical ripening process refers to the formation of silver halide grains by metathesis of soluble silver salt and soluble halide, and the physical ripening process refers to the formation of silver halide grains in the presence of excess halogen salt or excess halogen salt and ammonia. This refers to growing silver halide crystals to an appropriate size by heating and stirring. Furthermore, in the present invention, the desalting step refers to a step of removing soluble salts after the formation of emulsion grains is completed (after precipitation or physical ripening).

The desalting process typically involves the addition of a desalting agent, standing, and decantation, which are repeated at least once and usually several times, after which post-gelatin is generally added and dispersed, and then chemical In the sensitization step, the desalting step in the present invention refers to the period after precipitation formation or physical ripening and before chemical sensitization (at least the post-gelatin addition step is included).

There are various methods for desalting, such as the long-known Nodel water washing method in which gelatin is gelatinized, and inorganic salts made of polyvalent anions (for example, sulfuric acid #X such as sodium sulfate). anionic surfactant,
Anionic polymers (e.g. polystyrene sulfonic acid)
, or a precipitation method (flocculation) using a gelatin derivative (for example, aliphatic acylated gelatin, aromatic acylated gelatin, aromatic carbamoylated gelatin, etc.)
There is a method using

A preferred desalting means uses sulfate (MgSO4) as a desalting agent.
, Na25Oa, etc.), or anionic polymers (polystyrylsulfonic acid polymers such as those described in Japanese Patent Publication No. 35-16086, etc., or JP-A-62
A vinyl polymer having a carboxylic acid in the side chain described in Japanese Patent No. 32445 is used. In the present invention, the spectral sensitizing dye is added to each of these steps at any point (addition position) at any time during the silver halide grain formation step, physical ripening step, and desalting step.

In the present invention, the spectral sensitizing dye is added at a pH of 7.
5 to 1005, and is carried out in the form of a solution or dispersion (hereinafter referred to as the dye solution of the present invention) containing a spectral sensitizing dye and a hydrophilic polymer compound.

The hydrophilic polymer compound used in the present invention is preferably gelatin, but other compounds can also be used.

For example, gelatin derivatives, graft polymers of gelatin and other polymers Proteins such as albumin and casein; Cellulose derivatives such as hydroxyethyl cellulose, carboxymethyl cellulose, and cellulose sulfates; Sugar derivatives such as sodium alginate and starch derivatives; Polyvinyl alcohol, Polyvinyl alcohol partial acetal, poly-N-vinylpyrrolidone, polyacrylic acid,
A wide variety of synthetic hydrophilic polymeric materials can be used, such as single or copolymers of polymethacrylic acid, polyacrylamide, polyvinylimidazole, polyvinylpyrazole, and the like.

In addition to lime ring gelatin, acid-treated gelatin and Bul 1. Soc, Sci, Phot, Jap
an, No.16. Oxygen-treated gelatin as described in P2O (1966) may be used, and gelatin hydrolysates and oxygen-decomposed products may also be used. Examples of gelatin derivatives include various compounds such as acid halides, acid anhydrides, isocyanates, bromoacetic acids, alkanesultones, vinyl sulfonamides, maleimide compounds, polyalkylene oxides, and epoxy compounds. The product obtained by reacting can be used.

Specific examples include U.S. Pat.
No. 132.945, No. 3.186.846, No. 3.3
No. 12.553, British Patent No. 861,414, 1.0
No. 33,189, No. 1,005,784, Special Publication No. 1977
-26845 etc.

The gelatin-copolymer may include a single (homo) or copolymer of vinyl tertiary polymers such as gelatin, acrylic acid, methacrylic acid, derivatives thereof such as esters and amides, acrylonitrile, styrene, etc. Kuzeraft can be used. In particular,
Graft polymers on polymers having some degree of compatibility with gelatin, such as acrylic acid, methacrylic acid, acrylamide, methacrylamide, hydroxyalkyl methacrylates, are preferred. Examples of these are described in U.S. Pat. Nos. 2,763,625, 2,831,767, and 2.956.884.

The content of these hydrophilic polymer compounds is 0.005 to 2
0% by weight, preferably 0.01-10% by weight.

More preferably, it is 0.02 to 5% by weight.

Various spectral sensitizing dyes can be used in the present invention. For example, cyanine dye, merocyanine dye, complex cyanine dye, complex merocyanine dye,
Holopolar cyanine dyes, hemicyanine dyes, steryl dyes, and hekiomysanol dyes can be used.

Particularly useful dyes are cyanine dyes, merocyanine dyes and complex merocyanine dyes. These pigments include
Any of the nuclei commonly used for cyanine dyes can be used as the basic heterocyclic nucleus.

That is, viroline nucleus, oxazoline nucleus, thiazoline nucleus, pyrrole nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus, imidazole nucleus, tetrazole nucleus, pyridine nucleus, and a nucleus in which an alicyclic hydrocarbon ring is fused to these nuclei: and these. A nucleus in which an aromatic hydrocarbon ring is fused to the nucleus, i.e.
These include indolenine nucleus, benzindolenine nucleus, indole nucleus, benzoxazole nucleus, naphthoxazole nucleus, benzothiazole nucleus, naphthothiazole nucleus, penzosarenazole nucleus, benzimidazole nucleus, and quinoline nucleus. These nuclei may be substituted on carbon atoms.

Merocyanine dyes or composite merocyanine dyes include a nucleus having a ketomethylene structure 1, such as a pyrazolion-5-one nucleus, a thiohydantoin nucleus, and a 2-thioxazolidine-2 nucleus.
, 4-dione nucleus, thiazolidine-2゜4-dione nucleus, rhodanine ring, and thiobarbyl acid nucleus can be applied. These sensitizing dyes may be used alone or in combination. Specifically, for example, RD (Research Disclosure) 1
743, pages 22 to 24, RDl13716, page 648, right column and below, and the dyes described in JP-A-61-80237 can be preferably used.

Further, tricarbocyanine dyes and dicarbocyanine dyes containing a 4-quinoline nucleus, such as those described in JP-A-63-89838, can also be preferably used.

The dye liquid of the present invention has a pH of 7.5 to 1015, and has a pH of 7.5 to 1015.
As the H adjuster, ammonia water, sodium hydroxide,
Inorganic alkaline agents such as potassium hydroxide, sodium carbonate, and sodium bicarbonate, organic bases such as triethylamine and triethanolamine, inorganic acids such as sulfuric acid and nitric acid, and organic acids such as acetic acid, tartaric acid, and citric acid can be used.

The dye liquid of the present invention is preferably an aqueous solution, but the solvent or dispersion medium used may be water or a mixture of water and a water-soluble organic solvent. The content of the organic solvent used in the mixed liquid is preferably 10% by weight or less, more preferably 51% by weight or less.

Furthermore, a disaggregating agent such as a surfactant described in JP-A-63-55544 may be added to the dye solution of the present invention.

The dye liquid of the present invention is added to the silver halide emulsion in at least one of the silver halide grain formation process, physical ripening process, and desalting process, but the timing of addition is selected depending on the type of sensitizing dye and emulsion. be able to. The entire amount of the dye solution of the present invention can be added at once, it can be added in portions, or it can be added continuously in proportion to the growing surface of the silver halide grains.

The amount of the sensitizing dye added is ltag- per mole of silver.
1 gs is preferably 5 mg to 500 mg.

The composition of silver halide to which the present invention is applied is arbitrary,
For example, silver halides such as silver chloroiodobromide, silver chloride, silver chlorobromide, silver bromide, silver iodobromide, and silver iodide may be used. Silver iodobromide is preferred from the viewpoint of high sensitivity. Further, the average silver iodide content in the silver iodobromide is preferably 0.1 to 10 mol%, particularly preferably 1 to 8 mol%. The average grain size of the silver halide grains is preferably 0.2 to 8.0 μm, more preferably 0.3 to 1.5 μm.

Although the internal structure of the silver halide grains is arbitrary, those having a multilayer structure of two or more layers can be preferably used. In this case, it is preferable to have a layer in which the difference in silver iodide (Agl) content between adjacent layers is 20 mol% or more greater than the layer inside the grain. Further, each layer is preferably made of silver bromide or silver iodobromide. It is preferable that the localized portion in which silver iodide is localized at a high concentration of 20 mol % or more is located as far inward as possible from the outer surface of the grain, and particularly within 0.0 mol % from the outer surface.
It is preferable that the localized portion exists in a portion separated by 1 μm or more.

Silver halide emulsions are usually chemically sensitized.

As the chemical sensitization method, for example, gold sensitization, sensitization with Group I metal ions, sulfur sensitization, reduction sensitization, sensitization with thioether compound #1J, or a combination thereof; sensitization methods are applied. Ru.

More specific chemical sensitizers include sulfur sensitizers such as sulfur thiosulfate, allylthiocarbamide, thiourea, thiosulfate, and cystine, potassium chloroaurate, auricular thiosulfate, and potassium chloride. Examples include noble metal sensitizers such as valadate, and reduction sensitizers such as tin chloride and phenylhydrazine.

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 arbitrary additives, which are described in Research Disclosure FF-1F, Vol. 6, No. 17643 (January 1978).
(February) and Vol. 187, No. 18716 (November 1976), 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. It has at least one silver halide emulsion layer on at least one side.

That is, in the present invention, at least one 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 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 most of the emulsion layers, and more preferably all of the emulsion layers according to the present invention l) It contains such an emulsion. 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 silver halide photographic light-sensitive material of the present invention may have non-photosensitive layers such as a surface protective layer, an intermediate layer, and an antihalation layer in addition to the silver halide emulsion layer.

The silver halide photographic light-sensitive material of the present invention is produced by applying a silver halide emulsion to baryta paper, polyethylene-coated paper, polypropylene synthetic paper, glass paper, cellulose acetate, cellulose nitrate, etc. via a subbing layer, an intermediate layer, etc., if necessary.
It is constructed by coating on a support such as polyvinyl acetal, polypropylene, a polyester film such as polyethylene terephthalate, or polystyrene by a known method.

The silver halide photographic material of the present invention may be either a black-and-white photographic material or a color photographic material, and can be used for various purposes such as general use, printing, X-ray use, and radiation use. It exhibits remarkable effects as a sensitive silver iodobromide photographic material.

The silver halide photographic material of 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.

〔Example〕

The present invention will be explained in more detail below by showing examples of the present invention. However, it goes without saying that the present invention is not limited to the embodiments described below.

The compounds and sensitizing dyes used in the following examples are as follows.

Compound (I) Sensitizing dye (C) Compound (I[) Sensitizing dye (D) Sensitizing dye (A) OHONa Sensitizing dye (F) C! Ha (cuJ+5o3-sensitizing dye (G) Silver iodide 2 with an average particle size of 0.3 μl was produced using the double jet method while controlling the temperature at 60°C, pAg-8, and pH-2.0.
A monodisperse cubic emulsion (A) of silver iodobromide containing mol % was obtained. In this emulsion (A), the incidence of twins was 1% or less in terms of number, as determined by electron micrographs. Using this emulsion (A) as a seed crystal, grains were grown as follows.

That is, this seed crystal emulsion (A) was dissolved in a solution 8.512 containing protected gelatin kept at 40° C. and ammonia if necessary, and the pH was adjusted with acetic acid. Using this liquid as a mother liquid, a 3.2N aqueous ammoniacal silver ion solution was added 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, 1) Ag was controlled to 7.3 and pH to 9.7 to form a layer with a silver iodide content of 30 mol %.

The pH was then changed from 9 to 8 to form a layer of silver bromide. At this time, the pAg was kept at 9.0 until 95% of the particle size (step 1), and then a potassium bromide solution was added over 8 minutes with a nozzle to reduce the pAg to 11.0. Mixing was completed 3 minutes after the addition was completed. (Step 2). Next, the pH was adjusted to 6.0 with acetic acid (Step 3). The emulsion 1-1 thus obtained had an average grain size of 0.65 μm and a silver iodide content of the entire grains of about 2 mol %.

Next, a desalting step was performed to remove excess soluble salts from this reaction solution. That is, the reaction solution was kept at 40° C., compound (I) was added at 5 g/AgX 1 mol, and Mg5O was added at 8 g/AgX 1 mol, stirred for 5 minutes, and then left to stand still. Thereafter, the supernatant liquid was discharged to give a liquid volume of 200 cc per mole of Ag. Next, 1.812 mol of water/1 mol of AgX was added at 40°C (llI!), and the mixture was stirred for 5 minutes.
Step 4).

Next, 20 g/1 mole of AgX was added to the mixture, stirred in the same manner as above, and allowed to stand. The supernatant was removed and desalted.

This solution was then stirred (step 5). After stirring, post-gelatin was added to redisperse the silver halide, and 55%
Dispersed at °C.

The resulting emulsion was subjected to chemical sensitization as follows.

That is, the emulsion was first maintained at 55°C. Thereafter, ammonium thiocyanate, chloroauric acid, and hypo were added to perform gold-sulfur sensitization. After completion of sensitization, 4-hydroxy-〇-methyl-1.3,3a,7-tetrazaindene was added (Step 6).

In the present invention, an emulsion is obtained by adding a sensitizing dye, but the emulsion was prepared by changing the addition position. However, the addition position is at the end of each step. Further, the sensitizing dye was added in the form of a gelatin solution (dye solution). Table 1 shows the addition position of this dye solution, the type and amount of the sensitizing dye used, the amount of gelatin, and the pH of the dye solution.

The dye liquid storage solution used was one that had been left for one week under a daylight fluorescent lamp at 24° C. and 55% relative humidity.

To the emulsion obtained as described above, a conventional stabilizer was added in a conventional amount, namely, 4-hydroxy-6-methyl-1,3゜3a,
7-thitrazaindene in 2 x 10-” mol 1 mol A
In addition to gX, conventional inhibitors and other conventional stabilizers, hardeners and coating aids were added in the same manner as usual, and then this emulsion was coated on a polyethylene terephthalate base as a support as follows. That is, a copolymer made of three types of heptamers, 50% by weight of glycidyl methacrylate, 10% by weight of methyl acrylate, and 40% by weight of butyl methacrylate, was diluted to a concentration of 10% by weight. The aqueous polymer dispersion is used as a subbing liquid and is coated on a polyethylene terephthalate base, and the above emulsion is added to the film base thus obtained by adding a conventional antistatic agent, a conventional matting agent, a coating aid, etc. Sample No. 1 was coated uniformly on both sides with a gelatin protective layer containing a hardening agent and dried.
I got ~30. The coating amount of the emulsion of each sample was such that the rooting amount per side was 2.5 g/m''.

The obtained sample was exposed to 3.20 M5 at an exposure time of 1 second using the standard light B described on page 39 of the [New Edition: Lighting Data Book] (edited by the Illuminating Society of Japan, 1st edition, 2nd printing) as a light source. White exposure with a non-filter, and an optical path 15cm from the light source under the same conditions.
584 (manufactured by Eastman Kodak) and exposed to green light.

This sample was processed for 45 seconds with an XD-5R developing solution using a 5RX-501 automatic processor manufactured by Konica Corporation, and the sensitivity of each sample was determined. Sensitivity was determined by calculating the reciprocal of the amount of light necessary for the blackening density to increase by 1.0 due to exposure, and sample No. in Table 1 was used for both white exposure and green exposure.

It is expressed as a relative value with each sensitivity of 6 as 100. As is clear from Table 1, when the dye solution of the present invention is used, it has a high sensitivity, and there is almost no variation in sensitivity even when using the dye solution immediately after preparation and when it has been stored. A photosensitive material can be obtained.

Example 2.3.4 Instead of gelatin used in the dye solution in Example 1,
Gelatin-benzoyl chloride reactant, gelatin-hetatalic anhydride reactant and gelatin-P described in Examples 3, 5 and 8 of U.S. Pat. No. 2,614.928, respectively.
- Processing and sensitivity were determined in the same manner as in Example 1 except that the tolylisocyanate reactant was used. The method of the present invention had high sensitivity, and there was almost no variation in sensitivity due to storage of the dye solution. Ta.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a silver halide photographic material with almost no variation in sensitivity even if a highly sensitive and preserved dye solution is used.

Procedural amendment July IO date, 1999 1.Display of the incident 1988 Patent Application No. 263275 2. Name of the invention High sensitivity silver halide material 3. Person who makes corrections Relationship to the case Patent applicant Address: 26-2 Nishi-Shinjuku IT, Shinjuku-ku, Tokyo Contact information 〒191 1 Sakuracho, Hino City, Tokyo

Claims (1)

[Claims] On the support, in at least one of the particle forming step, the physical ripening step, and the desalting step, the pH is 7.5 to 10.
．． A silver halide photographic light-sensitive material comprising at least one silver halide emulsion layer obtained by adding a solution or dispersion containing a spectral sensitizing dye and a hydrophilic polymer compound adjusted to .