JPS60221320A - Novel silver halide crystal and its manufacture - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel silver halide crystal and a method for producing the same.

Monodisperse silver halide crystals of standard shape useful in photography are obtained by introducing separate streams of an aqueous solution of a water-soluble silver salt and a bath solution of a swamp salt of an alkali metal halide into a fully stirred gelatin solution, and It can be produced using a technique known as equilibrium dual jet precipitation, where the process is controlled to control the overall shape of the silver halide crystals produced.

There are many descriptions of core-shell structures for silver halide grains in various literatures. Typically, the entire surface of the core is coated with one or more layers, or "shells," of silver halide.

For experts in the field of photographic science, the halide ratio kf
It has been known for a long time to use both sensitized and unsensitized core-shell emulsions.

In addition, an epitaxial hybrid arsenic crystal that fully combines the radiation sensitivity of silver iodide and the rapid developability of silver chloride is disclosed in JP-A No. 53-103725;
No. 5-124139 discloses a hybrid composite having a different /10 silver saponide composition τ for the corner portion and the body portion.
Silver halide cubic crystals are disclosed. However, the specific crystal of the present invention has not been published in any literature.

It is an object of the present invention to provide a new type of silver halogenide crystal, the structure of which confers advantageous photographic properties.

Another object of the present invention is to provide a method for producing a photographic emulsion containing the novel silver halide crystals described above.

Another object of the present invention is to provide a photographic material that provides advantageous photographic properties using the above-described silver halide crystals.

The burnable silver halide crystal of the present invention is a cubic crystal, and each face of the crystal has a recess, or preferably, the recesses are deep and intersect with each other to form a space. It is a silver halogenide crystal with a structure of

The photographs attached as drawings (Figures 2 and 3) are photographs taken using an electron microscope of the silver halide crystals of the present invention, and show depressions (intermediate density) and spaces (
It can be seen that there are more crystals in the space in Figure 3.

The silver halogenide crystals of the present invention have higher commercial sensitivity than conventional cubic silver halogenide crystals of the same grain size and halogen composition.

The silver halide crystal of the present invention has a first silver halide crystal with high solubility and a second silver halide crystal with lower solubility.
The dissolution of the first silver chloride crystals and the formation of the 20th silver chloride are caused by introducing under certain conditions an aqueous solution of silver and a compound that forms silver chloride. It is thought that this can be obtained along with this.

That is, the 20th silver halogenide, S, starts to grow from each of the eight corners of the first silver halogenide crystal, and the growth is accompanied by the dissolution of the first silver halogenide crystal. It is inferred that this causes a depression, and as it progresses further, a space is formed.

It can be understood from Figures 2 and 3 that although it depends on the manufacturing conditions, the speed of the above-mentioned progress differs between each crystal or between each face (or each) of the crystals, so that different crystal forms coexist. .

The silver halide crystals of the present invention are produced by the balanced double jet sedimentation method. That is, a first monodisperse cubic crystal of silver halide is preferably prepared by equilibrium double-jet precipitation (Fig. 1), and then a second monodisperse cubic crystal is prepared by equilibrium double-jet precipitation, which includes a dissolution process of the first silver halide crystal. The silver halide is precipitated to produce monodisperse cubic silver halide crystals (FIGS. 2 and 3) formed by dissolving the first silver halide and having fc depressions or spaces. However, the first silver halide crystals do not necessarily have to be equilibrium double jet precipitated. The solubility of silver halide is determined by Mees and James [The Th
theory of the Photographic
As described in ProcessJ (1966) page 6,
Silver chloride, silver bromide, and silver iodide show values that are about 100 times smaller in that order. Therefore, it is preferable that the first and second silver halides useful in the present invention are mainly composed of silver chloride and silver bromide, respectively. Specifically, the halogen composition of the first silver halide is mainly silver chloride, and can contain up to 30 moles of silver bromide, and can further contain up to several moles of silver iodide. The halogen composition of the second silver halide is mainly silver bromide, and can contain up to 30 moles of silver chloride, and can further contain up to several moles of silver iodide.

The novel silver halide crystals of the present invention, together with the solubility conditions of the first and second silver halide, have certain conditions, i.e., supply of the second silver halide per unit number of the first silver halide crystals. It is produced by adding a water bath solution of halides and silver to an equilibrium double jet precipitation method in such a manner that the amount of silver is increased per unit time.

That is, the distance t (μm) between silver halide crystals in the first silver halide emulsion and the addition rate ap during equilibrium double jet precipitation of the second silver halide are specified as the manufacturing conditions. Must be. Here, the addition rate Rp is an amount defined as the number of moles of halide ions or silver ions supplied per hour per 1015 first silver rhodide crystals.

According to a preferred embodiment of the production method of the present invention, the equilibrium double jet precipitation of the second silver halide is carried out at a tXRpO value of 2.
to 20-1. When the value of zxRp is 2 or less, the second silver halide precipitates before the first silver halide is formed, so the silver halide having the interwall portion of the present invention is not formed. Furthermore, when the value of zxRp exceeds 20, second silver halide crystals are newly generated, and in either case, the useful photographic properties of the present invention cannot be obtained.

Furthermore, according to a preferred embodiment of the production method of the present invention, the temperature during equilibrium dual jet precipitation of the second halogen ion is in the range of 35°C to 70°C, pAg is in the range of 3 to 8, and pH is in the range of 4 to 8. It is preferable.

Next, preferred embodiments of the manufacturing method of the present invention will be described in more detail.

(a) a first monodisperse cubic silver halide emulsion;
Produced by the known equilibrium double jet precipitation method. That is, an aqueous solution of a water-soluble silver salt and an aqueous solution of an alkali metal halide are simultaneously added to an aqueous gelatin solution so as to maintain a constant pAg.

However, the halogen ions in the aqueous solution of water-soluble alkali metal halides are mainly chlorine ions, but bromine ions
It can contain up to several moles of iodide ions.

(b) Adjust the emulsion concentration so that the distance t between silver halide crystals in the first silver halide emulsion becomes a specified value. Here, the distance t between silver halide crystals can be calculated from the size of the silver halide crystals and the total number of moles of silver halide contained in the emulsion.

(C) The first silver halide emulsion (PH 4 to 8) in which the distance t between the silver halide crystals has been adjusted is maintained at a temperature of 35°C to 70°C and stirred vigorously, and an aqueous solution of a water bathable silver salt and At the same time, a water bath solution of a water bathing alkali metal halide was added to pA
Add so that g becomes a constant value in the range of 3 to 8. Here, the addition rate takes a value such that the value of zxRp ranges from 2 to 20. Further, the halogen ions in the aqueous solution of the water-soluble alkali metal halide are mainly bromide ions, but they can be contained in an amount of 30 moles of chloride ions and several moles of iodide ions.

(cl) The emulsion obtained in the second equilibrium double jet precipitation is precipitated by a known method and washed with water.

By the above method, a silver halide photographic material containing all monodisperse cubic silver halide crystals having spaces can be produced.

Examples of water-soluble silver salts used in equilibrium double jet precipitation include silver nitrate and silver perchlorate, and examples of water-based alkali metal halides include sodium halide and potassium halide. Furthermore, protective colloids for silver halide include gelatin, gelatin fat conductors, colloidal albumin, casein, cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose, agar,
Examples include sugar derivatives such as sodium alginate and starch derivatives, synthetic hydrophilic colloids such as polyvinyl alcohol, polyN-vinylpyrrolidone, polyacrylic acid copolymers, polyacrylamide, and derivatives thereof. Compatible mixtures of two or more may be used, such as copolymers of acrylamide, acrylic acid and methylvinylimidazole.

The silver halide photographic emulsion containing the novel silver halide crystals of the present invention may be doped with various metal salts or metal complex salts during or after crystal growth. For example, metal salts or complex salts such as gold, platinum, palladium, iridium, rhodium, bismuth, cadmium, copper, lead, and combinations thereof can be used.

Further, the emulsion of the present invention can be subjected to various chemical sensitization methods that are applied to general emulsions. i.e. active gelatin,
Noble metal sensitizers such as water-soluble gold salts, water-based platinum salts, water-based palladium salts, water-soluble rhodium salts, and water-based iridium salts;
Chemical sensitization can be carried out using sulfur sensitizers; selenium sensitizers; chemical sensitizers such as polyamines, reduction sensitizers such as stannous chloride, etc., either alone or in combination.

Furthermore, this emulsion can also be subjected to dye sensitization in a desired wavelength range.

The emulsion of the present invention can contain various commonly used additives depending on the purpose. For example, stabilizers and antifoggants such as azaindenes, triazoles, tetrazoles, imidazolium salts, tetrazolium salts, polyhydroxy compounds; aldehyde-based, aziridine-based, inoxazole-based, vinylsulfone-based, acryloyl-based, albodiimide-based, maleimide-based hardeners such as methane sulfonate, triazine, etc.; development accelerators such as benzyl alcohol and polyoxyethylene compounds; chroman,
Examples include Claman-based, bisphenol-based, and phosphite-based image stabilizers; lubricants such as waxes, glycerides of higher fatty acids, and higher alcohol esters of higher fatty acids. 'In addition, anionic, cationic, and nonionic surfactants are used as surfactants, as permeability improvers for processing solutions, defoaming agents, and as materials for controlling various physical properties of photosensitive materials. All kinds of substances of type or amphoteric nature can be used. As antistatic agents, diacetyl cellulose, styrene perfluoroalkyl rhidium maleate copolymer, styrene-maleic anhydride copolymer and P-
An alkali salt of a reaction product with amide/benzenesulfonic acid is effective. Examples of matting agents include polymethyl methacrylate, polystyrene, and alkali-soluble polymers. It is also possible to further use colloidal silicon oxide. Further, examples of the latex added to improve the overall physical properties of the film include copolymers of acrylic esters, vinyl esters, etc. and other monomers having ethylene groups. Examples of gelatin plasticizers include glycerin and glycol compounds, and examples of thickeners include styrene-sodium maleate copolymers, alkyl vinyl ether-maleic acid copolymers, and the like.

Supports for photographic materials made using the emulsion of the present invention prepared as described above include, for example, baryta paper, polyethylene paper, polypropylene synthetic paper, glass paper, cellulose acetate, cellulose nitrate, Polyvinyl acecool, polypropylene, e.g.
Examples include polyester films such as polyethylene terephthalate, polystyrene, and the like, and these supports are appropriately selected depending on the purpose of use of each silver halide photographic light-sensitive material. Further, these supports are subjected to undercoating processing as necessary.

The emulsion of the present invention can be effectively applied to photosensitive materials for a wide range of applications, including black and white general use, melay use, color use, infrared use, micro use, silver dye bleaching use, reversal use, and diffusion transfer use. I can do it.

In order to apply the emulsion of the present invention to a color photosensitive material, the emulsion of the present invention adjusted to have red sensitivity, green sensitivity, and blue sensitivity may be combined with cyan, macenta, and yellow turnip 2-. All methods and materials used for photosensitive materials may be used.

After exposure, a light-sensitive material prepared using the emulsion of the present invention can be developed by a commonly used known method.

The black and white developer is an alkaline solution containing developing agents such as hydroxybenzenes, aminophenols, and aminebenzenes, as well as alkali metal salts such as 1iiilcates,
Carbonate salts, bisulfites, bromides, iodides, etc. can be stored.

Further, when the light-sensitive material is for color use, color development can be carried out by a commonly used color development method.

In the reversal process, the image is first developed with a black-and-white negative developer, then exposed to white light, or treated with a bath containing a capric acid, and then color-developed with an alkaline developer containing a color developing agent. There are no particular restrictions on the processing method, and any processing method can be applied, but representative examples include a method in which color development is followed by bleach-fixing, followed by washing with water and stabilization treatment if necessary, or color development. After that, bleaching and constant separation are carried out, and if necessary, washing with water and stabilization treatment can be carried out. It is also known to process light-sensitive materials with low silver halide content using an approximation agent such as a hydrogen peroxide cobalt complex salt, and these methods can also be used for processing. Further, these treatments may be carried out at high temperatures in order to perform them quickly, or may be carried out at room temperature or, in special cases, lower temperatures. Pre-dural treatment can also be performed when rapid in-place treatment is performed.

Hereinafter, examples will be presented in order to fully understand the effects of the present invention, but the invention is not limited thereto.

Reference Example Using the three types of solutions shown below, a first equilibrium double jet precipitation was carried out to prepare a monodisperse cubic silver chloride emulsion.

[Bath liquid A]

[Bath liquid B] [Solution C] Add bath liquid B and solution C to solution A' while stirring at 60°C.
was added to solution A over 60 minutes using an equilibrium dual jet precipitation method. During the addition, the pAg value of solution A was maintained at 6.5 by measuring the silver potential and adjusting the flow rate of bath solution C. The finally obtained emulsion is shown in the electron micrograph in Figure 1 (1
They were monodisperse cubic silver chloride crystal grains having an average side length of 0.3 μm and having 0.00) faces. This emulsion will be referred to as IBM-1.

Example I By diluting with EM-1i gelatin water bath solution, a seed emulsion with a distance t between silver halide crystals of 1.39 μm and a gelatin concentration of 3% was obtained.

A second equilibrium double-jet precipitation was carried out using the following three types of bath sounds:

[Bath liquid A]

400 ml of seed emulsion (t=1.39 μm, PH=6).

[Solution B]

[Bath liquid C] While maintaining bath liquid A at 150°C and stirring, add solution B and bath gC to solution A at a speed of 2 to 7 minutes using an equilibrium double jet precipitation method.
The addition took 23 minutes. In this case, the RpO value of the number of moles of silver ions or bromine ions supplied per hour per 1015 seed crystals was 2.26. Therefore, the value of zxRp is 3.14. The pAg value of Solution A was maintained at 5.5 during the addition. The emulsion finally obtained was monodisperse cubic crystal grains having an average side length of 0.34 μm and having depressions or spaces, as shown in the electron micrograph of FIG.

This emulsion will be called EM-2.

Example 2 By diluting with EM-1i gelatin water bath solution, the distance t between silver halide crystals was 1.63 μm, and ze→壬so)R
The equilibrium double-jet precipitation of the Hiromoe trend 1 and I ears of q≦ is the following three types of solution/ll
! It was carried out using '.

[Bath liquid A]

Seed emulsion (t=1.63 μm, PH5) 140+/[Solution B] [Solution C] While keeping the solution at 45°C and stirring, add bath solution B and solution C to bath gA for 24 minutes by equilibrium double jet precipitation method. Speed, 5.
It took 5 minutes to add. In this case, ap (7) value U
9.68 fA, D, subv tetxkLp (7) Value f
d, 15.78. pAg' of bath solution A during the addition.
It was kept at 6.0. The finally obtained emulsion had an average side length of 0.34 μm as shown in the electron micrograph of FIG. 3, and was monodisperse cubic crystal grains having depressions or spaces. This emulsion will be called iEM-3.

Run 4113 By diluting with EM-1i gelatin water bath solution, a seed emulsion with a distance t between silver halide crystals of 0.83 μm and a gelatin concentration of 3% was obtained.

The second 10 m double jet precipitation was carried out using the following three types of solution sounds.

[Numa dA': 1 ridge milk i'tll (Z=0.83μm, PH, 6) 200
m/! [Bath liquid B] [Bath liquid C] While keeping the bath liquid at 50°C and stirring, mix # liquid B and m liquid C.
was applied to liquid A at a speed of 2'tnl 1 min for 38.5 minutes using an equilibrium double jet precipitation method.

In this case, the R2O value is 1.36, so t
The value of X J (, p was 1.13. During the addition,
The pAg of Jixin A was kept at 5.5. The final borrowed emulsion was found to have an average side length of 0.32
μm in diameter, it was a core-shell cubic crystal with no voids. This entire emulsion will be referred to as EM-4.

Example 4 As a comparative emulsion for examining the sensitivity to f of the emulsion of the present invention, a cubic arsenic emulsion having an average side length of 0.33 μm was prepared in the same manner as described in the reference example. This emulsion will be called 5EM-5.

Precipitation and washing with water were carried out according to the usual method, and 'fcEM-2, EM-
3. To E 4-4. Equal parts of each part of EM-5 were mixed with sodium chlorauric acid salt and sodium thiosulfate to achieve maximum sensitivity at pH 5 and pAg 7.3 and temperature of 50°C. At that time, it was sensitized using a conventional method. These emulsions were spun and coated onto a film support. When tested under the same exposure and development conditions, the emulsions EM,-2, EM-3 of the present invention were as soft as the soft emulsions EM-4, E.
It showed more than twice the sensitivity than M-5.

[Brief explanation of the drawing]

Figure 1 shows the first silver halide (silver chloride) crystal produced in Reference Example, Figure 2 shows the halogen II crystal of the present invention produced in Example 1, and Figure 3 shows the crystal produced in Example 2. 3A and 3B are electron micrographs showing silver halide crystals of the invention, respectively. 1st mouth 1”I

Claims (3)

[Claims] (1) A silver halide crystal that is a cubic crystal and has a depression or space on each face of the crystal. (2) forming a first monodisperse cubic silver halide crystal by an equilibrium double jet precipitation method, then total precipitation of a second silver halide crystal having a lower solubility than the first silver halide crystal; A method for producing a monodisperse cubic silver halide crystal in which each face of the crystal has depressions or walls by melting the silver halide crystal. (3) The production method according to claim 2, which is carried out under conditions in which the second silver halide precipitation 'fctXRpO value is from 2 to 20. (However, t is the distance M (in μm) between the first silver halide crystals, and Rp is the halide ion of the second silver halide supplied in 1 hour per 1015 first silver halide crystals, or (Represents the number of moles of silver ions.)