JPS5853328B2 - Spectrally sensitized silver halide photographic emulsion - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a silver halide photographic emulsion spectrally sensitized with a novel merocyanine dye, and particularly to a silver halide photographic emulsion with increased spectral sensitivity in the blue and green wavelength regions. be.

Photographic materials are required to have high sensitivity in different wavelength ranges depending on their intended use.

As one of the manufacturing techniques for such light-sensitive materials, various types of cyanine dyes and merocyanine dyes are added to silver halide photographic emulsions, and these dyes are used to produce specific photosensitive materials in wavelength ranges longer than the wavelength range to which silver halide is uniquely sensitive. It is generally well known that the sensitivity in the wavelength range can be extremely effectively increased.

Among these, although various types of merocyanine dyes have been studied so far, the reality is that there are only a few that satisfy photographic properties including sensitization.

In other words, when applying the spectral sensitization method using merocyanine dyes to silver halide photographic emulsions, it is necessary not only to impart a spectral sensitization effect and increase sensitivity, but also to satisfy the following requirements. No.

(1) The spectral sensitization region is appropriate.

(2) There should be no adverse interaction with other additive chemicals for photography, and the photographic properties should be maintained stably even during storage of the photosensitive material.

(3) It is required that no coloring or fogging due to residual dyes administered for spectral sensitization be left after the development process.

In particular, in recent years, with the spread of processing systems using automatic processors, the processing time has been significantly shortened, and for this reason, coloring tends to remain after processing, and there is a need for spectral sensitization technology using dyes with less residual color. It is being

For example, there is a method to reduce the appearance of residual coloring by using a fluorescent brightener, but in order to cover up the residual coloring,
It is necessary to pay sufficient attention to the amount used and the effect on photographic characteristics.

There is also a method of increasing the water solubility of the sensitizing dye and reducing residual coloring after development by introducing a water-solubilizing group such as a carboxy group or a sulfo group into the dye molecule structure.

However, this method also shows that under the same amount of dye used,
Although residual coloring is certainly improved, sensitization is generally lower than that of dyes without water-solubilizing groups.

Furthermore, when the amount used is increased in order to increase sensitivity, the residual coloring density also increases in many cases.

Therefore, a first object of the present invention is to provide a spectrally sensitized silver halide photographic emulsion that has high sensitivity in the blue and green wavelength ranges and has little coloration or fog due to residual dyes.

A second object of the present invention is to provide a spectrally sensitized silver halide photographic emulsion that exhibits little decrease in sensitivity when the manufactured photographic material is aged.

As a result of various studies, the present inventors have found that the above objects can be effectively achieved by incorporating at least one of the novel merocyanine dyes represented by the following general formula (1) into a silver halide photographic emulsion. I found it.

General formula (1) In the formula, Z represents an atomic group necessary to form a dihydro-4)(-1,3-oxazine ring.

The carbon atoms of this ring may have substituents such as alkyl groups (eg, methyl, ethyl, etc.), alkoxy groups (eg, methoxy, ethoxy, etc.), aryl groups (eg, phenyl), and the like.

Q represents an atomic group necessary to form a pyrazolone ring, a thiobarbic acid ring, a 2-thioxapridine 2,4-dione ring, a 2-thiohydantoin ring, and a rhodanine ring.

These rings may be substituted with the following groups.

That is, alkyl groups (for example, lower alkyl groups such as methyl, ethyl, propyl, butyl, cycloalkyl groups such as cyclohexyl, sulfoalkyl groups such as 2-sulfoethyl, 3-sulfopropyl, 3-sulfobutyl, 4-sulfobutyl, etc.), carboxy Carboxyalkyl groups such as methyl, 2-carboxyethyl, 3-carboxypropyl, 4-carboxybutyl, hydroxyalkyl groups such as 2-hydroxyethyl, 3-hydroxypropyl, 4-hydroxybutyl, 2-methoxyethyl, 3-methoxypropyl alkoxyalkyl groups such as 2-acetoxyethyl, acyloxyalkyl groups such as 2-benzoyloxyethyl, alkoxycarbonylalkyl groups such as methoxycarbonylmethyl, 2-methoxycarbonylethyl, 4-ethoxycarbonylbutyl, 2-sulfadobutyl, 4
- sulfatoalkyl groups such as sulfadobutyl, aralkyl groups such as benzyl, phenethyl, P-sulfobenzyl, etc.), alkenyl groups (e.g. allyl), aryl groups (
For example, phenyl, biphenyl, carboxydiphenyl,
sulfophenyl, tolyl, anisyl, chlorophenyl, etc.).

R1 represents a hydrogen atom, an alkyl group (for example, a lower alkyl group such as methyl or ethyl, a substituted alkyl group such as β-hydroxyethyl group or carboxymethyl), or an aryl group (for example, phenyl, tolyl, carboxyphenyl, etc.) .

R2 is an alkyl group (for example, lower alkyl group, sulfoalkyl group, carboxyalkyl group, hydroxyalkyl group, alkoxyalkyl group, acyloxyalkyl group, alkoxycarbonylalkyl group, sulfatoalkyl group as defined in the substituent examples for Q) , aralkyl group, etc.),
Represents an alkenyl group (eg allyl).

Further, among the dyes represented by the general formula (1), particularly preferred are those in which the ring containing Q is a 2-thioxapridine-2,4-dione ring, a 2-thiohydantoin ring,
This is the case when it is a rhodanine ring or a thiobarbituric acid ring.

Next, typical examples of dyes used in the present invention will be given.

The dye represented by the general formula (I) used in the present invention can be easily synthesized by a conventional method well known to those skilled in the art by merocyanine dye synthesis.Next, typical examples will be described. .

Synthesis Example 1: Exemplary dye (1) (I) 300.9 of 2-methyl-4H-5,6-sihydro 1.3 oxazine was dissolved in 11 ethyl acetate, 900 g of ethyl iodide was added thereto, and the mixture was heated under reflux for 3 hours. did.

After cooling, the precipitated crystals were collected. After recrystallization with isopropanol and drying, 440.9% of white needle crystals were obtained.

This crystal was hygroscopic and was used in the next reaction without measuring its melting point.

(II) 254 g of ethyl orthoformate was added to 440 g of 3-ethyl-2-methyl-4H-5,6-sihydro-1,3-oxazinium ioside obtained in reaction (I) above, and after heating on a water bath for 1 hour. Add 160g of aniline and add 1
．． Heated for 5 hours.

After cooling, the precipitated crystals were collected in a furnace and washed with ethanol.

When recrystallized from ethanol and dried, the melting point is 181.0-2.
．． 203 g of yellowish white needle crystals at 0°C were obtained.

(1) 2-ω-anilinovinyl=3-ethyl-4H-5,6-sihydro1.3 obtained in reaction (II) above
-203g of oxazinium yossite and 600r of acetic anhydride
After adding Ill, the mixture was heated under reflux for 30 minutes.

After cooling, ether was added and the supernatant was decanted.

After washing the candy with ether, acetone was added and stirred, and the candy became solid.

It was taken out of the furnace and washed with acetone.

When recrystallized from ethanol and dried, the melting point is 149.5-1.
105 g of yellow-brown crystalline powder at 50.5° C. was obtained.

(a) 4.00 g of 2-ω-acetanilide vinyl-3-ethyl-4H-5,6-sihydroxazinium iodide obtained in reaction (II) above and 1.3-dimethyl 2-thiohydantoin. Dissolve 44 g in 50 ml of ethanol, and add 3.0 g of triethylamine to this. After adding OOg, the mixture was heated under reflux for 30 minutes.

After cooling, the precipitated crude pigment was collected and washed with a small amount of ethanol.

Then, when recrystallized from ethanol and dried, the melting point was 206.5.
1.60 g of an orange crystalline powder of ˜7.5° C. was obtained.

Synthesis Example 2: Exemplary dye (22) 3-ethyl-2-methyl-4H-5,6-sihydro 1
．． 2.55 g of 3-oxazinium yossite and 3.06 g of 5-acetanilide methylene-3-ethylrhodanine. F
was dissolved in 50 ml of ethanol, and then 3.00 g of triethylamine was added thereto, followed by heating under reflux for 30 minutes.

After cooling, the precipitated crude pigment was collected and washed with a small amount of ethanol.

Next, when recrystallized from ethanol and dried, the melting point was 186.5.
1.80 g of red and colored platelets of 6C (decomposed) were obtained.

The absorption maximum value (n m 7) of the methanol solution of the representative example of the dye used in the present invention is as follows.

Exemplary dye (1)465 Exemplary dye (21)458
(2) 458 (22) 475 (3) 47
3 (23) 459 (4) 458
(24) 475 (5) 458 (2
5) 458 (6) 456 (26) 460
(7) 476 (27) 470 (8) 45
8 (28) 458 (9) 465
(29) 475 (10) 402
(30) 458 (11) 458
(31) 450 (12) 467 (
32) 451 (13) 458 (3
3) 458 (14) 459 (34
) 455 (15) 459 (35)
458 (16) 461 (36)
468 (17) 456 (37) 4
55 (18) 458 (38) 41
2 (19) 476 (39) 456
(20)459 The silver halide photographic emulsion used in the present invention may be any of silver chloride, silver bromide, silver chlorobromide, silver iodobromide, silver chloroiodobromide, etc. produced by a conventional method. In order to add the dye to these silver halide photographic emulsions, an aqueous solution or a solution in an organic solvent optionally miscible with water, such as methanol, ethanol, acetone, cellosolve, pyridine, dimethylformamide, etc., alone or in combination, can be used. It can be added as

Although these dyes may be added to the silver halide photographic emulsion at any time during the emulsion manufacturing process, it is generally preferable to add them immediately after the second ripening.

The amount added varies depending on the type of dye or the type of silver halide photographic emulsion, but it can be used in a wide range of about 4 to 1,200 µm per 100 g in terms of silver nitrate.

The silver halide photographic emulsion used in the present invention may be subjected to noble metal sensitization, sulfur sensitization, reduction sensitization, a combination thereof, or addition of a polyalkylene oxide compound or the like.

The silver halide photographic emulsion of the present invention may be color sensitized by using other sensitizing dyes, for example, known cyanine and merocyanine dyes, as required, and furthermore, by a known method, stabilizers, surfactants, etc. Additives such as agents, hardeners, brighteners, UV absorbers, preservatives, matting agents, plasticizers, etc. may be included.

When the silver halide photographic emulsion of the present invention is used in a light-sensitive material for color photography, it may contain a color coupler or a dispersant thereof.

Furthermore, when used in a photosensitive material for stabilization processing, a developing agent may also be included.

Protective colloids for the silver halide photographic emulsion of the present invention include, in addition to gelatin, gelatin derivatives such as phthalated gelatin and malonated gelatin, cellulose derivatives, soluble starch, and water-soluble polymers.

Examples of the support used in the present invention include baryta paper, plastic-laminated paper, synthetic paper, and resin films such as cellulose triacetate and polyethylene terephthalate.

If necessary, a subbing layer and an antihalation layer can be applied to these supports by a known method.

EXAMPLES The present invention will be described in detail below based on Examples, but the present invention is of course not limited thereto.

Example 1 A pure silver bromide emulsion prepared by the double jet method was subjected to second ripening by the sulfur sensitization method, and then the emulsion was divided into several parts and sensitizing dyes were added in the amounts shown in Table 1 below. A solution of was added.

After this emulsion was aged in a bath at about 40°C for 45 minutes to stabilize the color sensitization effect, predetermined amounts of coating aids and hardeners were added, and then coated on a paper support laminated with polyethylene.
Dried and cut into strips.

A portion of this strip was aged for 2 days at 50° C. and 80% relative humidity.

These samples were exposed to light using a sensitometer having a light source with a color temperature of 5.4000, and the white light sensitivity was measured.

Further, exposure was performed to obtain a spectrum using a diffraction grating type spectrograph having a tungsten light source at 2666°.

Subsequently, each sample was developed using D-72 developer (developed by Eastman Kodak, USA) at 20°C for 90 seconds, stopped, fixed, and washed with water. After drying, a prescribed black and white image was formed. I got Motsu Strips.

This is MACBETH manufactured by Macbeth Corporation in the United States.
Density was measured using a TD-504 densitometer to obtain white light sensitivity.

The optical density reference point for determining sensitivity is 0.75 in both cases.
This was the point.

The results obtained are shown in Table 1 as relative values.

Table 1 *White light sensitivity is expressed as a relative value with the value of the raw emulsion without dye added as 100.

As is clear from Table 1 above, the novel merocyanine dye used in the present invention shows sufficient spectral sensitization effect.

In addition, almost no staining due to residual dye was observed after development.

Furthermore, with respect to the samples aged for 2 days at 50° C. and 80% relative humidity, almost no change was observed in sensitivity or fog.

The high value of fog is due to the fact that no fog suppressant was added to the pure silver bromide emulsion that was tested to see the true behavior of the sensitizing dye.

Example 2 A silver chlorobromide emulsion prepared by the single-jet method was subjected to a second sulfur sensitization method, and then the emulsion was divided and treated with the amounts of sensitizing dyes shown in Table 2 below and each fixed amount. After adding a certain amount of fog suppressant, processed gelatin, coating aid, and hardening agent, the mixture was coated on a polyethylene-laminated paper support, dried, and a sample piece was collected.

For comparison, one without a sensitizing dye (comparative sample A) and one with a sensitizing dye of the following structure added, ○-CH-CH eyes ≦
-)=S N N 1 0 C2H5c2H6 (Comparative Sample B) and a sensitizing dye having the following structure (Comparative Sample C) were added to prepare a comparative sample.

Some of these sample pieces were heated at 40° C. for 2 days for sensitivity measurement.

Another sample piece was kept at 50°C for development fog and dye removal measurement.
It was aged for 2 days under conditions of relative humidity of 80%.

The sample piece for sensitivity measurement was treated in the same manner as in Example 1, and after drawing a characteristic curve, the sensitivity was determined based on the point giving an optical density of 0.60.

Development fog was determined by immersing the film in the D-72 developer for 5 minutes at 20°C, stopping, fixing, washing with water, drying, and then measuring the optical density.

The dye-free sample pieces were processed in a Mitsubishi MR Processor Model 330 automatic processor as follows.

1. Current bath: Mytone (Chugai Photo Pharmaceutical ■Prescription) 33°
CI 3 seconds 2, fixing bath: My Fix Rapid P (Chugai Photo Yakuhin ■
Prescription) 33°C 13 seconds 3, water washing bath: water flow 61/min 16 seconds
Measure a, b, and compare b with comparative sample A (no dye)
The difference in values (Δb) was taken as a measure of pigment loss.

The results are shown in Table 2.

Table 2 As is clear from Table 2 above, the novel merocyanine dye used in the present invention exhibits a sufficient spectral sensitizing effect over Comparative Sample A (no dye).

Furthermore, there is almost no fog, and there is no sensitizing effect on photographic properties.

Furthermore, it is clear that staining due to residual dye after processing with an automatic processor is significantly improved compared to Comparative Samples B and C.

Claims (1)

[Scope of Claims] 1. A spectrally sensitized silver halide photographic emulsion characterized by containing at least one sensitizing dye represented by the following general formula (I). General formula (I), Z R1,Q, \1. PA1'C=CH-C=C-C=0'/N2 [Wherein, Z represents an atomic group necessary to form a 4H-5,6-sihydro-1,3-oxazine ring. Q represents an atomic group necessary to form a pyrazolone ring, a thiobarbic acid ring, a 2-thioxapridine-2,4-dione ring, a 2-thiohydantoin ring, and a rhodanine ring. R1 represents a hydrogen atom, an alkyl group or an aryl group. R2 represents an alkyl group or an alkenyl group. 2. The spectrally sensitized silver halide photographic emulsion according to claim 1, wherein the Q-containing ring in general formula (1) is a 2-thioxapridine-2,4-dione ring. 3. The spectrally sensitized silver halide photographic emulsion according to claim 1, wherein the Q-containing ring in general formula (I) is a 2-thiohydantoin ring. 4. The spectrally sensitized silver halide photographic emulsion according to claim 1, wherein the Q-containing ring in general formula (1) is a rhodanine ring. 5. The spectrally sensitized silver halide photographic emulsion according to claim 1, wherein the Q-containing ring in general formula (1) is a thiobarbic acid ring.