JPS62215261A - Photographic silver halide emulsion - Google Patents

Abstract

PURPOSE:To obtain a photographic silver halide emulsion having high sensitivity to color sensitization by dissolving a spectral sensitizing dye in water in the presence of an ether deriv. of cyclodextrin which makes the practically water- insoluble dye soluble in water so as to improve the stability of the dye. CONSTITUTION:An ether deriv. of cyclodextrin used is prepd. by etherifying a compound represented by the formula (where n is an integer of >=5) by the alkylation of hydroxyl groups in the compound. The hydroxyl groups at the 2- and 6-positions are preferably alkylated. For example, heptakis-2,6-dimethyl-beta- cyclodextrin has remarkably high solubility in water, so various advantages are expected. A spectral sensitizing dye used is preferably of nonion, betaine or cation type. The ether deriv. of cyclodextrin is used by an amount required to dissolve the spectral sensitizing dye and the preferred amount of the deriv. is 10-100 times the amount of the dye.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a halogenated dye that is useful for spectral sensitization (spectral sensitizing dye) dissolved in an aqueous medium using an ether derivative of cyclodextrin. Regarding silver photographic emulsions.

(Prior Art) In the production of photographic light-sensitive materials, spectral sensitization technology, that is, a method of expanding the sensitive wavelength range of light-sensitive materials to the visible range and even the infrared range, is important, especially in the production of photographic light-sensitive materials. It is well known that this technology is essential for color photosensitive materials.

When a spectral sensitizing dye is added to a silver halide photographic emulsion, the state of adsorption on the surface of silver halide microcrystals varies significantly depending on the conditions under which it is added, resulting in photographic effects such as cuffing, sensitivity, and spectral sensitivity distribution. , which has a significant effect on desensitization and sensitivity stability. This is sh, e, k.

The Theory of the Technical Process by C.E. Mees
eory of the Photographic P
rocess) 2nd edition (published by Macmillan in 1954), Chapter 12, pages 430 to 500.

Generally, many of the spectral sensitizing dyes in silver halide photographic emulsions are substantially insoluble in water. For this reason, the commonly used method for adding spectral sensitizing dyes to silver halide photographic emulsions is to first add organic solvents that are freely miscible with water, such as acetone, methanol, ethanol, propatool,
Dissolve the dye in methyl cellosol, pyridine, etc.
This is a method of adding it to an emulsion. A portion of water may be mixed and added to this organic solvent. As described in Japanese Patent Publication No. 44-23389, a method of adding a strong acid to a sensitizing dye having an amidinium ion chromophore to protonate it and adding it as an aqueous solution, and as described in Japanese Patent Publication No. 44-22948, There is a method of dispersing the dye in the parent wood colloid by adding and mixing a substantially water-insoluble sensitizing dye to a colloid of a volatile solvent and heating it to remove the solvent.

(Problems to be Solved by the Invention) However, these methods have many deficiencies. First, the commonly used method of adding the organic solvent by dissolving it in an organic solvent that is freely miscible with water reduces the surface activity of the coating aid coexisting with the organic solvent, coagulates the binder, and adds color. In the case of photosensitive materials, coexisting couplers are solidified, making high-speed coating, for example, coating over 100 m per minute, extremely difficult. On the other hand, when added, the organic solvent used immediately mixes with water, so it may adsorb to the binder or aggregate itself before adsorbing to the sensitizing dye or silver halide crystals. may provide only weak spectral sensitivity. Furthermore, methods using organic solvents are not preferred from the viewpoint of explosion protection. Next, the method described in Japanese Patent Publication No. 44-23389 makes the aqueous solution strongly acidic, which is often unfavorable from the viewpoint of dye stability. Also, the special public official public interest rate was 44-229.
The method of dispersing a pigment in parent wood colloid described in Japanese Patent No. 48 requires an organic solvent, and therefore has the same drawbacks as the case using the organic solvent.

Therefore, an object of the present invention is to provide a silver halide photographic emulsion in which a spectral sensitizing dye is made into an aqueous solution without using an organic solvent or a strong acid.

(Means for Solving the Problems) The present inventors have conducted extensive research to overcome the above problems, and have found that by making a spectral sensitizing dye into an aqueous solution in the presence of an ether derivative of cyclodextrin, By making the spectral sensitizing dye, which was virtually insoluble in water, soluble in water,
It has been discovered that a desired silver halide photographic emulsion can be prepared, and the present invention has been completed based on this knowledge.

That is, the present invention provides a silver halide photographic emulsion characterized by containing a spectral sensitizing dye dissolved in an aqueous medium in the presence of an ether derivative of cyclodextrin.

Cyclodextrin is a compound in which many D(+)-glucobylanose units form a ring through α-1,4= bonds, and depending on the number of glucose units constituting one molecule,
α (6 units), β (7 units), γ (8 units), etc. are prefixed with α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, etc., respectively.
... (see general formula (I)). this house,
Three types, α, β, and γ, are well known and commercially available.

These are also sometimes called cyclohexaamylose, cyclohexaamylose, cyclooctaamylose, etc. Also known are derivatives in which the hydroxyl group of these cyclodextrins is replaced by an ether, ester, amino group, or the like. Regarding these siphrobuchytrins, see Cyclodextrin Chemistry, M. L., Bender, M. Komyama.
rinChemistry) Sbringerfuerlag, published in 1978.

The ether derivative of cyclodextrin used in the present invention refers to one in which the hydroxyl group of the compound represented by the above general formula (I) is alkylated to become an ether. Among various ether derivatives, those in which two positions, the 2-position and the 6-position, are etherified are particularly preferred. An example of this is heptakis-2,6-dimethyl-β-cyclodex1
~ Phosphorus, hexakis-2,6-dimethyl-α-cyclodextrin, octakis-2,6-dimethyl-γ-cyclodextrin, etc. are available. For example, heptakis-2,6-ramethyl-β-cyclodextrin has significantly increased solubility in water compared to β-cyclodextrin, which is less soluble in water (1.85g/100m).
Reach more than double. Therefore, it becomes possible to prepare concentrated aqueous solutions, which is expected to have many advantages over β-cyclodextrin.

The sensitizing dyes used in the present invention include cyanine dyes, merocyanine dyes, composite cyanine dyes, composite merocyanine dyes, holopolar cyanine dyes, hemicyanine dyes, styryl dyes, and hemiogisonol dyes. Particularly useful dyes include those belonging to cyanine dyes, merocyanine dyes and complex merocyanine dyes. Preferably used sensitizing dyes include nonionic, betaine, and cationic sensitizing dyes. Any of the nuclei commonly used for cyanine dyes can be used as the basic heterocyclic nucleus for these dyes. Namely, pyridine nucleus, oxazolidine, thianrin nucleus,
Virol nucleus, oxazole nucleus, thiazole nucleus, selenazole nucleus, imidazole nucleus, tetrazole nucleus, pyridine nucleus, etc.; a nucleus condensed with an alicyclic hydrocarbon ring to these nuclei, and an aromatic hydrocarbon ring condensed to these nuclei Nuclei, namely, indolenine nucleus, benzindolenine nucleus, indole nucleus, benzoxazole nucleus, naphthoxazole nucleus, benzothiazole nucleus, naphthothiazole nucleus, benzoselenazole nucleus, penzimitazole nucleus, naphthoxazole nucleus, quinoline nucleus imitane [4,5-b] quinoxaline nucleus etc. can be applied. These nuclei may be substituted on carbon atoms.

For merocyanine dyes or complex merocyanine dyes,
- As a nucleus having a methylene structure, pyrazolin-5-one nucleus, thiohytantoin nucleus, 2-thioxazolidine-
2,4-dione nucleus, thiazolidine-2,4-dione nucleus,
Rhodanine nucleus, thiobarbyl acid group, 2-thioselenazolidine-2,4-dione nucleus, pyrazolo[1,5-a]
A 5- to 6-membered heterocyclic nucleus such as a penzimitazole nucleus or a pyrazolo[5,1-b]quinasolone nucleus can be applied. Furthermore, F., M. Hammer, “Heterocyclic Compounds - Cyanine Dyes and Related Compounds”, Schonwille Ant.
The dyes described in Sands (New York, London), 1964 are used.

The amount of the ether derivative of Sifurobukis 1 to Phosphorus used in the present invention is the amount necessary to dissolve the spectral sensitizing dye, and this may vary depending on the type and concentration of the spectral sensitizing dye.
The molar ratio is usually 1 to 10,000 times, preferably 10 to 1,000 times, and more preferably 10 to 100 times the molar ratio of the spectral sensitizing dye.

In the present invention, the amount of spectral sensitizing dye used in the silver halide photographic emulsion is not particularly different from the conventional method.

The preparation of Kibatomo's silver halide photographic emulsion is usually carried out by dissolving a spectral sensitizing dye in an aqueous solution of an ether 1 derivative of Schiflovkis 1 to Phosphorus, and mixing this aqueous solution with a silver halide photographic emulsion. .

The aqueous spectral sensitizing dye solution used in the present invention can be prepared by the following method. For example, (1) an aqueous solution of a needle derivative of cyclodextrin is prepared and a powder of a spectral sensitizing dye is added thereto.

(2) Add the ether derivative of cyclodextrin and the spectral sensitizing dye to water simultaneously. Alternatively, you can add water later.

At this time, a treatment to improve the wettability of the spectral sensitizing dye (for example, wetting it with a small amount of water-soluble organic solvent) may be applied.

The aqueous solution obtained here can be added to the silver halide emulsion during or after the formation of silver halide grains, at the beginning or end of chemical ripening, before the water washing step, or at any time during the formation of silver halide grains. Also includes. At this time, a compound that is more easily included in the ether derivative of cyclodextrin than the spectral sensitizing dye used may be used (eg, added after addition of the dye aqueous solution, added to the emulsion in advance, etc.).

The silver halide emulsion used in the present invention is usually prepared by mixing a water-soluble silver salt (for example, silver nitrate) solution and a water-soluble halide salt (for example, potassium bromide) solution in the presence of a water-soluble polymer solution such as gelatin. able to make. As the silver halide, in addition to silver chloride and silver bromide, mixed silver halides such as silver chlorobromide, silver iodobromide, silver chloroiodobromide, etc. can be used. The average grain size of silver halide grains (in the case of spherical or approximately spherical grains, the grain size is taken as the grain diameter; in the case of cubic grains, the grain size is expressed as the ridge length, and the average is expressed in terms of the projected area) is 4 JLm or less is preferred. The particle size distribution may be narrow (so-called "monodisperse") or broad.

The shapes of these silver halide grains are cubic, tetradecahedral,
Any rhombic dodecahedral, octahedral, mixed crystal shape, spherical shape, plate shape, etc. may be used.

Further, an emulsion may be used in which ultratabular silver halide grains having a grain diameter of five times or more the grain thickness occupy 50% or more of the total projected area. For details, see JP-A-58-12792.
1, No. 58-113927, etc.

Furthermore, two or more types of silver halide photographic emulsions formed separately may be mixed. Furthermore, even if the crystal structure of silver halide grains is uniform inside, there are also grains with a layered structure in which the halogen composition inside and outside differs, and those described in British Patent No. 635,841 and US Patent No. 3,622. There may also be a so-called conversion type as described in , No. 318. Further, either a type in which a latent image is mainly formed on the surface or an internal latent image type in which a latent image is formed inside the particle may be used.

These photographic emulsions are described in James James, "The Theory of Photographic Process", 4th edition, Matsukumiran Publishing (1976); p. Grafkide, "Simmy".
``Photographic Emulsion Chemistry'' by G. F. Daaffin (Published by Four Power J.Repress, 1966), V. L. Zelikman et al. Author: “Making and Coating Photographic Emergence” () Ocalref.

James r The T
theory of the Photographic
ProcessJ The 4th edition,
Mac Millan (1976), P. Glaf
kids, “Chimie et Physique
Photographique'' (Paul Mon
tel, 1967), G., F., Duffin, P.
photographic Emulsion Chemi
try'' (The Focal Press, 19
66), V.

L, Zelika+an et al, “Maki
ng and coatingphotography
c Emulsion'' (The Focal Pre
ss.

1964)). That is, any of the acidic method, neutral method, ammonia method, etc. may be used, and the method for reacting the soluble silver salt with the soluble halogen salt may be any one-sided mixing method, simultaneous mixing method, or a combination thereof. good.

It is also possible to use a method in which particles are formed in an excess of silver ions (so-called back-mixing method).

As one form of the simultaneous mixing method, a method in which p and Ag in the liquid phase in which silver halide is produced can be kept constant, that is, a so-called Chondrald or double jet method can also be used. According to this method, a silver halide emulsion having a regular crystal shape and a nearly uniform grain size can be obtained.

Two or more types of silver halide emulsions formed separately may be mixed and used.

The silver halide emulsion may be a so-called primitive emulsion which is not chemically sensitized, but it is usually chemically sensitized. For chemical sensitization, the above-mentioned book by Grafkide or Zerikman et al., or by H.
Friesel ed.
er Photography Proze
ssemit Silbcrbalogeniden
” AkademischeVcrlagsgese
llschaft (1968)).

In other words, sulfur sensitization using active gelatin and compounds containing sulfur that react with silver (e.g. thiosulfates, thioureas, mercapto compounds, rotanidines), reducing substances (
For example, reduction sensitization using stannous salts, amines, hydrazine derivatives, formamidine sulfinic acid, silane compounds), noble metal compounds (for example, gold compounds, as well as metals from group Ⅰ of the periodic table such as platinum, iridium, palladium, etc.) A noble metal sensitization method using complex salts of 1,2,2, etc. can be carried out alone or in combination.

Binders or protective colloids used in photosensitive materials include:
Although it is advantageous to use gelatin, other hydrophilic colloids may also be used.

As the gelatin, lime-treated gelatin, acid-treated gelatin, gelatin derivatives, etc. can be used.

Also, various other additives may be used. For example, color formers (e.g. yellow couplers, magenta couplers, cyan couplers, etc.), optical brighteners (stilbenes, etc.)
, anti-coupler, stabilizer (1-phenyl-5-mercaptotetrazole, 4-hydroxy substituted (1,3,3a,
7) Tetraazaindene, etc.), desensitizers, hardeners (e.g. 1.3.5-triacryloyl-hexahythroyl-5-
t-Ryazine, 2,4-dichloro-6-hydroxys
-) riazine, etc.), coating aids, antistatic agents, plasticizers,
Slip agents, matting agents, development accelerators, oils (e.g. phthalate alkyl esters, phosphate esters, etc.), mordants, ultraviolet absorbers, anti-fading agents (hydroquinone derivatives, etc.), color coupler inhibitors (hydroquinone derivatives, etc.)
, anti-piping agents (2-thiazolylbenzicitazoles, intiazolones, etc.).

For more information on these additives, please refer to Research Disclosure (RESEARCH DISCLO3URE).
) No. 176, pp. 22-31 (RD-17643) (D
EC, 1978) can be used.

The finished emulsion is coated onto a suitable support such as baryta paper, resin coated paper, synthetic paper, triacetate film, polyethylene terephthalate film, other plastic bases or glass plates. i.e. dip coat, air knife coat, curtain coat, or U.S. Pat. No. 2,681,2
A photographic light-sensitive material can be obtained by coating by various coating methods including extrusion coating using a hopper as described in No. 94.

Photographic materials in which the photographic emulsion of the present invention can be used include various color and black-and-white light-sensitive materials.

For example, color negative film for photography (general use, movie use, etc.)
, color reversal film (for slides, movies, etc., and may or may not contain couplers), color photographic paper, color positive film (for movies, etc.), color reversal photographic paper, color photosensitive materials for heat development, silver Color light-sensitive materials using the bare bleaching method, photographic light-sensitive materials for plate making (lith film,
scanner film, etc.), X-ray photosensitive materials (direct,
(indirect medical use, industrial use, etc.), black and white negative film for photography, black and white photographic paper, microphotosensitive materials (for C0M, microfilm, etc.), color diffusion transfer photosensitive materials (DTR), silver salt diffusion transfer photosensitive materials, printouts Examples include photosensitive materials.

When the photoresponsive material of the present invention is a photosensitive material, any known method can be used for its photographic processing, and known processing solutions can be used. Also, the processing temperature is usually chosen between 18°C and 50°C;
The temperature may be lower than 18°C or above 50°C. Depending on the purpose, either a developing process for forming a recorded image (black and white photographic process) or a color photographic process consisting of a developing process for forming a dye image can be applied.

For details regarding the development processing method, see Research Disclosure No. 176, pages 28 to 30 (RD-176
43) (Dec, 1978).

(Effects of the Invention) According to the present invention, by using an ether derivative of cyclodextrin, a spectral sensitizing dye, which has conventionally been substantially insoluble in water, can be made soluble in water. Therefore, the stability of the spectral sensitizing dye in an aqueous solution is high, and it exhibits excellent effects as a silver halide photographic emulsion with high color sensitization sensitivity. It is assumed that these effects are due to the inclusion of the ether derivative of cyclodextrin. Such a silver halide photographic emulsion of the present invention has improved dispersion stability of the contained components without using an organic solvent, and has excellent coating properties such as suitability for high-speed coating.

(Example) Next, the present invention will be explained in more detail based on examples.

Reference Example 1 Regarding the following two types of spectral sensitizing dyes, heptakis-2,
The difference in water solubility between the presence and absence of 6-dimethyl-β-cyclodextrin (DMCD) was measured. The results are shown in Table 1.

Dye 1 Dye 2 Table 1 As is clear from the above results, the solubility of the spectral sensitizing dye in water can be increased by adding DMCD.

Example 1 Dye 1 was prepared using 5% DMCD aqueous solution.
A mol/l solution was prepared and added to a silver halide emulsion. Spectral sensitization experiments were conducted on this silver halide emulsion. Details are as below.

An aqueous solution containing potassium bromide and sodium chloride at a molar ratio of 7:3 and an aqueous silver nitrate solution were added to an aqueous gelatin solution containing sodium chloride under vigorous stirring, and a silver chlorobromide emulsion (silver bromide content: 70%) was prepared by simultaneous mixing. Mol%, average particle size 0.45 lm
, coefficient of variation 15%) were prepared. Furthermore, 2.0×10 sodium thiosulfate was added to the above emulsion per mole of silver halide.
-5 mol, 1.0X10-4 mol of sensitizing dye l was added,
Optimal sensitization was performed to obtain the highest sensitivity. In addition, when adding the above-mentioned dye, the above-mentioned aqueous solution of 5% hebutakis-2,6-dimethyl-β-cyclodextrin (trade name: Seldex Nippon Foods Chemical Co., Ltd.) was added as a solvent, and for comparison. Prepare one without adding sensitive dye 1,
The resulting red-sensitive silver chlorobromide emulsions were designated as A and A, respectively.

Next, cyan couplers *a and *b are dissolved in a mixture of dibutyl phthalate (DBP) and ethyl acetate, along with anti-fade agent *C1 ultraviolet absorber *d, *e, *f, containing sodium dodecylbenzenesulfonate. It was emulsified and dispersed in a 10% aqueous gelatin solution. (See Table 2 for the amount of each chemical.) This emulsified dispersion was mixed with the emulsions A and I to prepare a coating solution, which was coated on double-sided polyethylene laminated paper to prepare samples No. 101 and 102, respectively. The polyethylene on the coated side contains titanium dioxide as a white pigment and a trace amount of ultramarine blue. Gelatin was applied as a protective layer. As a hardening agent for each layer, 2,4-dichloro-6-hydroxy-5-)-lyazine sodium salt was used. Table 2 shows the contents and coating amount of the coating sample.

For comparison, when 1.0xlO-4 mole of sensitizing dye was added without using cyclodextrin, the amount of water required for dissolution was large and good coating could not be achieved.

(*a) Cyan coupler (*b) Cyan coupler W (*C) Anti-fading agent (*d) Ultraviolet absorber H (*e) Ultraviolet absorber (*f) Ultraviolet absorber R 4H9 [tl These The sample was subjected to gradation exposure for sensitometry through a red filter using an enlarger (Fushicolor Head 609 manufactured by Fuji Photo Film Co., Ltd.), and then subjected to the following processing steps.

Processing process Temperature Time Developer
Bleach-fix solution for 3.5 minutes at 33°C Wash with water for 1.5 minutes at 33°C Wash for 3.0 minutes at 24-35°C Diethylenetriaminepentavinegar vinegar/5Na 2.0g Benzyl alcohol 15m diethylene glycol 10m Naz so3
2. OgKBr
0.5g hydroxylamine sulfate
3.0g4-amino-3-methyl-N-ethyl-N-(β-(methanesulfonamido)ethyl]-p-phenylenecyamine sulfate 5.OgN a 2
CO3 (-water salt) 30.0g Fluorescent brightener (stilbene type) 1.0g Add water to make 1 liter (pH 10,1) Bleach-fix ammonium thiosulfate (54wt%) 50nlj Naz so3 15.0gNH4
(Fe (EDTA)) 55. OgEDTA・
Add 4.0 g of 2Na to make up to 1 liter (pH 6,9) The results obtained are shown in Table 3. Sensitivity is sample no.

The sensitivity of 101 was set to 100 for convenience. Sensitivity was expressed as a relative value of the reciprocal of the exposure amount required to provide the minimum density plus 0.5. As shown in Table 3, it can be seen that color sensitization sensitivity was obtained in the system using the solvent of the present invention. It was also confirmed in a similar experiment using different exposure filters that the two sample emulsions had similar intrinsic sensitivities.

Table 3 Example 2 The stability of an aqueous solution of Dye 1 was evaluated. A sample containing 5% DMCD (A) and a sample without DMCD (B) (each dye concentration 2X 10-4 mol/view) were stored at room temperature in the dark.
The absorbance was compared between the sample immediately after preparation and the sample after one week. The results are shown in Table 4.

Table 4 The values in the table are relative values of absorbance measured after each sample was diluted 20 times with methanol.

As is clear from the above examples, it is clear that the method of the present invention makes it possible to make sensitizing dyes that are poorly soluble in water soluble in water, enable spectral sensitization, and further stabilize the aqueous solution. be.

Claims (1)

[Claims] A silver halide photographic emulsion comprising a spectral sensitizing dye dissolved in an aqueous medium in the presence of an ether derivative of cyclodextrin.