Title:
LIGHT-SENSITIVE SILVER HALIDE COLOR PHOTOGRAPHIC EMULSION
United States Patent 3808945
Abstract:
An alkoxal-oxy type coupler of the formula: ##SPC1## And at least one coupler of the formulas: ##SPC2## Or ##SPC3## Wherein R is substituted aryl, substituted aralkyl or a saturated or unsaturated aliphatic group having 1-22 carbon atoms; R' is an aliphatic group having 1-6 carbon atoms; R" is COCH3, COOC2 H5 or ##SPC4## And X is hydrogen or a group which will split off during the dye forming reaction and will not substantially color the coupler, is incorporated into a photographic material containing a light-sensitive gelatino silver halide photographic emulsion. The resultant material exhibits improved graininess and control of photographic gamma, without exhibiting desensitization.
US Patent References:
COLOR-PHOTOGRAPHIC SILVER HALIDE MATERIALS CONTAINING COLORED AND UNCOLORED COUPLERS
Oishi et al. - February 1972 - 3642485
LIGHT-SENSITIVE SILVER HALIDE COLOR PHOTOGRAPHIC MATERIALS CONTAINING CYAN COUPLER
Iwama et al. - March 1972 - 3649285
COLOR-PHOTOGRAPHIC SILVER HALIDE MATERIALS CONTAINING COLORED AND UNCOLORED COUPLERS
Oishi et al. - February 1972 - 3642485
LIGHT-SENSITIVE SILVER HALIDE COLOR PHOTOGRAPHIC MATERIALS CONTAINING CYAN COUPLER
Iwama et al. - March 1972 - 3649285
Inventors:
Matsuo, Shunji (Tokyo, JA)
Sato, Shui (Tokyo, JA)
Endo, Takaya (Tokyo, JA)
Kasai, Keiji (Tokyo, JA)
Inoue, Izaburo (Tokyo, JA)
Sato, Shui (Tokyo, JA)
Endo, Takaya (Tokyo, JA)
Kasai, Keiji (Tokyo, JA)
Inoue, Izaburo (Tokyo, JA)
Application Number:
05/236655
Publication Date:
05/07/1974
Filing Date:
03/21/1972
View Patent Images:
Export Citation:
Assignee:
Konishiroku Photo Industry Co., Ltd. (Tokyo, JA)
Primary Class:
Other Classes:
430/380, 430/553, 430/552, 430/443, 430/562, 430/543, 430/957, 430/558
International Classes:
G03C7/305; G03C7/333; G03C7/34; G03C1/40
Field of Search:
96/9,100
Primary Examiner:
Brown, Travis J.
Attorney, Agent or Firm:
Bierman & Bierman
Claims:
What we claim is
1. A light-sensitive gelatino silver halide color photographic emulsion which contains an alkoxal-oxy type coupler of the general formula (I) in combination with one or both of a naphthol or phenol type colorless coupler of the general formula (II) and a phenol type colored coupler of the general formula (III) said general formula (I) being ##SPC13##
2. A light-sensitive gelatino silver halide color photographic emulsion as claimed in claim 1, wherein said alkoxal-oxy type coupler of the general formula (I) is a compound of the following structural formula ##SPC18##
3. A light-sensitive gelatino silver halide color photographic emulsion as claimed in claim 1, wherein said colorless compler of the general formula (II) is a compound of the following structural formula ##SPC19##
4. A light-sensitive gelatino silver halide color photographic emulsion as claimed in claim 1, wherein said colored coupler of the general formula (III) is a compound of the following structure formula ##SPC20##
1. A light-sensitive gelatino silver halide color photographic emulsion which contains an alkoxal-oxy type coupler of the general formula (I) in combination with one or both of a naphthol or phenol type colorless coupler of the general formula (II) and a phenol type colored coupler of the general formula (III) said general formula (I) being ##SPC13##
2. A light-sensitive gelatino silver halide color photographic emulsion as claimed in claim 1, wherein said alkoxal-oxy type coupler of the general formula (I) is a compound of the following structural formula ##SPC18##
3. A light-sensitive gelatino silver halide color photographic emulsion as claimed in claim 1, wherein said colorless compler of the general formula (II) is a compound of the following structural formula ##SPC19##
4. A light-sensitive gelatino silver halide color photographic emulsion as claimed in claim 1, wherein said colored coupler of the general formula (III) is a compound of the following structure formula ##SPC20##
Description:
This invention relates to a light-sensitive color photographic material capable of giving an excellent color photographic image which contains an iodine-substituted alkoxal-oxy type cyan coupler in combination with one or two of known cyan couplers.
An alkoxal-oxy type cyan coupler has the formula, ##SPC5##
Where R is a substituted aryl group, a substituted aralkyl group or a saturated or unsaturated aliphatic hydrocarbon radical having one to 22 carbon atoms; R' is an aliphatic hydrocarbon radical having one to six carbon atoms; and X is a hydrogen or halogen atom.
The dye-forming reaction mechanism of the alkoxal-oxy type cyan coupler has not been clarified yet, though it would be clearly elucidated by future studies, but is somewhat different from that of a conventional cyan coupler. That is, a cyan coupler having an -OH group in the 4-position and a cyan coupler having an alkoxal-oxy group in such position are greatly different from each other in shape of spectral curve, photosensitivity and graininess, though the two are entirely identical in structure of other portion, and the characteristics of the coupler having an alkoxal-oxy group in the 4-position cannot be anticipated from the coupler having an -OH group. It may therefore be said that the alkoxal-oxy type coupler is different in kind from the conventional cyan couplers.
According to the present invention, an iodine-substituted alkoxal-oxy type cyan coupler is used in admixture with other cyan coupler to make it possible to attain an effect which has never been anticipatable from a mere alkoxal-oxy type coupler or a mere iodine-substituted coupler, or from a mixture of said two couplers.
It was considered that alkoxal-oxy type couplers had such drawback that they were somewhat desensitized. However, it has been found that not only an iodine-substituted alkoxal-oxy type cyan coupler itself has excellent characteristics but also a mixture of said coupler with other cyan coupler results in such remarkable effect that the mixture can display such merits of alkoxal-oxy type cyan coupler as control of photographic gamma, improvement of graininess, etc., without any desensitization at all.
In case a light-sensitive photographic material is required to be improved in graininess or controlled in photographic gamma, there has heretofore been used a cyan coupler having an -OH group in the 4-position which contains as substituent an iodine atom or a group capable of being split-off to yield a development inhibitor (i.e. a so-called development inhibitor-yielding coupler), as disclosed in, for example, U.S. Pat. No. 3,227,554 or Belgian Pat. No. 737,971. However, an iodine-substituted coupler having an -OH group in the 4-position cannot give such favorable effects as mentioned above. As will be illustrated in the working examples shown later, iodine-substituted cyan couplers of the naphthol or phenol type, which have widely been known hitherto, have no such effect as to lower the photographic gamma, and light-sensitive photographic materials containing said couplers show up such phenomena that they are prevented from desensitization but rather become high in photographic gamma. Accordingly, ordinary iodine-substituted cyan couplers have not been able to improve light-sensitive materials in graininess and to lower them in gamma value, without deteriorating the photosensitivities thereof. Further, other substituent than iodine is required to be a group capable of satisfying such conditions that it should be suitable in split-off rate, should act as a development inhibitor after splitting, and should give no detrimental effect at all, and thus no satisfactory cyan coupler has been obtained yet.
As the result of extensive studies, we have found that a satisfactory cyan coupler can be obtained by replacing the active point of a cyan coupler with an iodine atom, which is less in problem when the coupler is incorporated into a photographic emulsion, and replacing the hydrogen atom of the -OH group of the coupler with an alkoxal-oxy group. Even when used alone, the iodine-substituted alkoxal-oxy type cyan coupler exhibits excellent characteristics, but it has been found that when the said coupler is used in admixture with other known cyan coupler, the mixed coupler displays such effects as control of photographic gamma and improvement of graininess and desensitization which have never been expected hitherto.
That is, the present invention is concerned with a light-sensitive color photographic material characterized by containing an alkoxal-oxy type coupler of the general formula (I) in combination with one or both of a naphthol type or phenol type colorless coupler of the general formula (II) and a phenol type colored coupler of the general formula (III).
General formula (I): ##SPC6##
General formula (II): ##SPC7##
General formula (III): ##SPC8##
wherein R is a substituted aryl group, a substituted aralkyl group or a saturated or unsaturated aliphatic hydrocarbon radical having one to 22 carbon atoms; R' is an aliphatic hydrocarbon radical having one to six carbon atoms; R" is COCH 3 , COOC 2 H 5 or ##SPC9##
and X is a hydrogen atom or an atomic group capable of being split off at the time of dye-forming reaction which does not substantially color the coupler.
Typical examples of the alkoxal-oxy type coupler of the general formula (I) which is used in the present invention are as follows: ##SPC10##
Examples of the known coupler of the formula (II), which is used in admixture with the above-mentioned coupler, are those shown below, but these are, of course, not limitative. The mixing proportion of the known coupler is ordinarily in the range from about 30 percent to about 80 percent based on the amount of the alkoxal-oxy type coupler, but varies depending on the structure and application purpose of the coupler, and there are some cases where the optimum mixing proportion is out of the above-mentioned range. ##SPC11##
Examples of the diazo-substituted colored coupler of the general formula (III) are as follows: ##SPC12##
In order to incorporate the couplers used in the present invention into a light-sensitive color photographic material, there may be adopted any of the known procedures. For example, the couplers are dissolved in either one, or if necessary in a mixture, of a high boiling solvent having a boiling point of more than 175° C. such as tricresyl phosphate or dibutyl phthalate and a low boiling solvent such as butyl acetate or butyl propionate. The resulting solution is mixed with an aqueous gelatin solution containing a surface active agent, and the mixed solution is formed into a dispersion by means of a high speed rotary mixer or a colloid mill. The thus formed dispersion is added directly to a silver halide photographic emulsion, which is then coated on such a support as glass plate, synthetic resin sheet, film base, baryta paper or laminated paper, followed by drying to remove a major proportion of the low boiling solvent. Alternatively the said dispersion is set, finely cut to noodless and freed from the low boiling solvent by water-washing or the like procedure, and the residue is added to a light-sensitive photographic emulsion, which is then coated on the above-mentioned support, followed by drying. In the above manner, a light-sensitive color photographic material of the present invention can be obtained.
The amount of the couplers to be added is ordinarily within the range from 5 to 15 mole percent based on the amount of the silver halide used. However, equivalent effects can, of course, be obtained even if the amount of the couplers is out of said range.
The light-sensitive photographic material of the present invention may be developed according to any procedure for the development of ordinary light-sensitive color photographic materials, and no particular consideration is required to be taken.
That is, as the color developing agent, there may be used any of such aromatic primary amino compounds as set forth below.
1. Diethyl-p-phenylenediamine hydrochloride
2. Monomethyl-p-phenylenediamine hydrochloride
3. Dimethyl-p-phenylenediamine hydrochloride
4. 2-Amino-5-diethylaminotoluene hydrochloride
5. 2-Amino-5-(N-ethyl-N-dodecylamino)-toluene
6. N-Ethyl-N-β-methanesulfonamidoethyl-3-methyl-4-aminoaniline sulfate
7. N-Methyl-N-β-methanesulfonamidoethyl-4-aminoaniline
8. 4-N-Ethyl-N-β-hydroxyethyl-aminoaniline
The developer solution may contain a sulfite, carbonate, bisulfite, bromide or iodide of an alkali metal. The photographic emulsion used in the present invention may have been chemically sensitized or may have been optically sensitized by means of a carbocyanine, merocyanine or the like dye, and may have been incorporated with ordinary photographic additives such as, for example, antifoggant, stabilizer, anti-stain agent, physical property-improving high molecular additive, hardener, coating aid, etc. When an ultraviolet absorber is incorporated into a light sensitive color photographic material containing the couplers used in the present invention, a color image obtained from the photographic material can further be enhanced in durability. Furthermore, the color developer solution may contain, in addition to the aforesaid developing agent, such a development controller as citrazinic acid or the like.
The accompanying drawing shows the spectral curves of the light-sensitive color photographic materials of the present invention which are described in Example 1 shown later.
The present invention is illustrated in further detail below with reference to examples, but it is needless to say that the scope of the invention is not limited to these.
EXAMPLE 1 PREPARATION OF SAMPLES 1 TO 5
Sample 1:
2.0 Grams of the exemplified coupler II-1 was dissolved at 60° C. in a mixed solvent comprising 2.0 ml. of dibutyl phthalate and 3.0 ml. of butyl acetate. The resulting solution was mixed with 10 ml. of a 10 percent aqueous solution of Alkanol B (alkylnaphthalene sulfonate produced by Du Pont) and 10 ml. of a 5 percent aqueous gelatin solution, and then subjected to a colloid mill to form a coupler dispersion. The thus formed coupler dispersion was added to 100 ml. of a red-sensitive high speed gelatin-silver iodobromide emulsion, which was then coated on a film base.
Sample 2:
2.0 Grams of the exemplified coupler I-1 was treated in the same manner as in the case of the sample 1.
Sample 3:
A mixture of 1.0 g. of the exemplified coupler I-1 and 1.0 g. of the exemplified coupler II-1 was treated in the same manner as in the case of the sample 1.
Sample 4:
A mixture of 1.6 g. of the exemplified coupler I-2 and 0.4 g. of the exemplified coupler III-2 was treated in the same manner as in the case of the sample 1.
Sample 5:
A mixture of 1.2 g. of the exemplified coupler I-1, 0.6 g. of the exemplified coupler II-3 and 0.4 g. of the exemplified coupler III-2 was dissolved in a mixed solvent comprising 2.5 ml. of dibutyl phthalate and 5.0 ml. of butyl acetate, and the resulting solution was treated in the same manner as in the case of the sample 1.
The above-mentioned samples were individually exposed according to an ordinary procedure and then developed at 20° C. for 10 minutes with a developer of the following composition:
N-Ethyl-N-β-methanesulfonamidoethyl-3-methyl-4-aminoani line 5.0 g. Anhydrous sodium sulfite 2.0 g. Benzyl alcohol 3.8 g. Sodium carbonate (monohydrate) 5.0 g. Potassium bromide 1.0 g. Caustic soda 0.55 g. Water to make 1,000 ml.
Subsequently, the developed samples were subjected to ordinary stop-fixing treatment, washed with water for 10 to 15 minutes, and then treated for 5 minutes with a bleaching solution of the following composition:
Potassium ferricyanide 100 g. Potassium bromide 50 g. Water to make 1,000 ml.
Thereafter, the samples were washed with water for 5 minutes and then dried. Photographic properties of the thus treated samples were as set forth in Table 1.
Table 1 ____________________________________________________________ ______________ Relative Gamma D-max Grainin- Sample speed (γ) ess ____________________________________________________________ ______________ 1 Exemplified 100 0.98 2.05 Relative- coupler II-1 ly fine 2 Exemplified 86 0.79 1.87 Fine coupler I-1 3 Exemplified coupler I-1 93 0.92 2.10 Fine do. II-1 14 Exemplified coupler I-2 90 0.91 1.74 Fine do. III-2 5 Exemplified coupler I-1 do. II-3 96 0.94 1.61 Fine do. III-2 ____________________________________________________________ ______________
Spectral curves of the samples 1, 3 and 5 were as shown in the accompanying drawing, in which the dotted line (.....), solid line (--) and chained line (.--.--) show the spectral curves of the samples 1, 3 and 5, respectively.
EXAMPLE 2
A high speed emulsion after completion of chemical ripening was subjected to optical sensitization by addition of a red-sensitive sensitizing dye 3,3'-diethyl-5,5'-dichloro-9-ethylthiacarbocyanine bromide. This emulsion was divided into three portions (each 100 ml. in amount) to prepare samples 1, 2 and 3. On the other hand, 2.0 g. of the exemplified coupler II-6, a mixture of 1.0 g. of the exemplified coupler I-3 and 1.0 g. of the exemplified coupler II-6, and a mixture of 1.0 g. of the exemplified coupler II-6, 0.8 g. of the exemplified coupler I-3 and 0.4 g. of the exemplified coupler III-2 were individually dissolved in a mixed solvent comprising 2.0 ml. of dibutyl phthalate and 6.0 ml. of butyl acetate, and then dispersed in the same manner as in Example 1 to prepare coupler dispersions (a), (b) and (c), respectively. The dispersion (a) was added to the sample 1, the dispersion (b) to the sample 2, and the dispersion (c) to the sample 3. Thereafter, the samples 1, 2 and 3 were treated in the same manner as in Example 1 to obtain the results as set forth in Table 2.
Table 2 ____________________________________________________________ ______________ Relative Gamma D-max Grainin- Sample speed (γ) ess ____________________________________________________________ ______________ 1 Exemplified 100 1.13 2.32 Relative- coupler II-6 ly fine 2 Exemplified coupler I-3 95 0.98 2.20 Fine do. II-6 3 Exemplified coupler I-3 do. II-6 92 0.94 2.14 Fine do. III-2 ____________________________________________________________ ______________
As is clear from Table 2, the samples according to the present invention are favorable in control of gamma and in graininess, and are excellent as lightsensitive color photographic materials.
An alkoxal-oxy type cyan coupler has the formula, ##SPC5##
Where R is a substituted aryl group, a substituted aralkyl group or a saturated or unsaturated aliphatic hydrocarbon radical having one to 22 carbon atoms; R' is an aliphatic hydrocarbon radical having one to six carbon atoms; and X is a hydrogen or halogen atom.
The dye-forming reaction mechanism of the alkoxal-oxy type cyan coupler has not been clarified yet, though it would be clearly elucidated by future studies, but is somewhat different from that of a conventional cyan coupler. That is, a cyan coupler having an -OH group in the 4-position and a cyan coupler having an alkoxal-oxy group in such position are greatly different from each other in shape of spectral curve, photosensitivity and graininess, though the two are entirely identical in structure of other portion, and the characteristics of the coupler having an alkoxal-oxy group in the 4-position cannot be anticipated from the coupler having an -OH group. It may therefore be said that the alkoxal-oxy type coupler is different in kind from the conventional cyan couplers.
According to the present invention, an iodine-substituted alkoxal-oxy type cyan coupler is used in admixture with other cyan coupler to make it possible to attain an effect which has never been anticipatable from a mere alkoxal-oxy type coupler or a mere iodine-substituted coupler, or from a mixture of said two couplers.
It was considered that alkoxal-oxy type couplers had such drawback that they were somewhat desensitized. However, it has been found that not only an iodine-substituted alkoxal-oxy type cyan coupler itself has excellent characteristics but also a mixture of said coupler with other cyan coupler results in such remarkable effect that the mixture can display such merits of alkoxal-oxy type cyan coupler as control of photographic gamma, improvement of graininess, etc., without any desensitization at all.
In case a light-sensitive photographic material is required to be improved in graininess or controlled in photographic gamma, there has heretofore been used a cyan coupler having an -OH group in the 4-position which contains as substituent an iodine atom or a group capable of being split-off to yield a development inhibitor (i.e. a so-called development inhibitor-yielding coupler), as disclosed in, for example, U.S. Pat. No. 3,227,554 or Belgian Pat. No. 737,971. However, an iodine-substituted coupler having an -OH group in the 4-position cannot give such favorable effects as mentioned above. As will be illustrated in the working examples shown later, iodine-substituted cyan couplers of the naphthol or phenol type, which have widely been known hitherto, have no such effect as to lower the photographic gamma, and light-sensitive photographic materials containing said couplers show up such phenomena that they are prevented from desensitization but rather become high in photographic gamma. Accordingly, ordinary iodine-substituted cyan couplers have not been able to improve light-sensitive materials in graininess and to lower them in gamma value, without deteriorating the photosensitivities thereof. Further, other substituent than iodine is required to be a group capable of satisfying such conditions that it should be suitable in split-off rate, should act as a development inhibitor after splitting, and should give no detrimental effect at all, and thus no satisfactory cyan coupler has been obtained yet.
As the result of extensive studies, we have found that a satisfactory cyan coupler can be obtained by replacing the active point of a cyan coupler with an iodine atom, which is less in problem when the coupler is incorporated into a photographic emulsion, and replacing the hydrogen atom of the -OH group of the coupler with an alkoxal-oxy group. Even when used alone, the iodine-substituted alkoxal-oxy type cyan coupler exhibits excellent characteristics, but it has been found that when the said coupler is used in admixture with other known cyan coupler, the mixed coupler displays such effects as control of photographic gamma and improvement of graininess and desensitization which have never been expected hitherto.
That is, the present invention is concerned with a light-sensitive color photographic material characterized by containing an alkoxal-oxy type coupler of the general formula (I) in combination with one or both of a naphthol type or phenol type colorless coupler of the general formula (II) and a phenol type colored coupler of the general formula (III).
General formula (I): ##SPC6##
General formula (II): ##SPC7##
General formula (III): ##SPC8##
wherein R is a substituted aryl group, a substituted aralkyl group or a saturated or unsaturated aliphatic hydrocarbon radical having one to 22 carbon atoms; R' is an aliphatic hydrocarbon radical having one to six carbon atoms; R" is COCH 3 , COOC 2 H 5 or ##SPC9##
and X is a hydrogen atom or an atomic group capable of being split off at the time of dye-forming reaction which does not substantially color the coupler.
Typical examples of the alkoxal-oxy type coupler of the general formula (I) which is used in the present invention are as follows: ##SPC10##
Examples of the known coupler of the formula (II), which is used in admixture with the above-mentioned coupler, are those shown below, but these are, of course, not limitative. The mixing proportion of the known coupler is ordinarily in the range from about 30 percent to about 80 percent based on the amount of the alkoxal-oxy type coupler, but varies depending on the structure and application purpose of the coupler, and there are some cases where the optimum mixing proportion is out of the above-mentioned range. ##SPC11##
Examples of the diazo-substituted colored coupler of the general formula (III) are as follows: ##SPC12##
In order to incorporate the couplers used in the present invention into a light-sensitive color photographic material, there may be adopted any of the known procedures. For example, the couplers are dissolved in either one, or if necessary in a mixture, of a high boiling solvent having a boiling point of more than 175° C. such as tricresyl phosphate or dibutyl phthalate and a low boiling solvent such as butyl acetate or butyl propionate. The resulting solution is mixed with an aqueous gelatin solution containing a surface active agent, and the mixed solution is formed into a dispersion by means of a high speed rotary mixer or a colloid mill. The thus formed dispersion is added directly to a silver halide photographic emulsion, which is then coated on such a support as glass plate, synthetic resin sheet, film base, baryta paper or laminated paper, followed by drying to remove a major proportion of the low boiling solvent. Alternatively the said dispersion is set, finely cut to noodless and freed from the low boiling solvent by water-washing or the like procedure, and the residue is added to a light-sensitive photographic emulsion, which is then coated on the above-mentioned support, followed by drying. In the above manner, a light-sensitive color photographic material of the present invention can be obtained.
The amount of the couplers to be added is ordinarily within the range from 5 to 15 mole percent based on the amount of the silver halide used. However, equivalent effects can, of course, be obtained even if the amount of the couplers is out of said range.
The light-sensitive photographic material of the present invention may be developed according to any procedure for the development of ordinary light-sensitive color photographic materials, and no particular consideration is required to be taken.
That is, as the color developing agent, there may be used any of such aromatic primary amino compounds as set forth below.
1. Diethyl-p-phenylenediamine hydrochloride
2. Monomethyl-p-phenylenediamine hydrochloride
3. Dimethyl-p-phenylenediamine hydrochloride
4. 2-Amino-5-diethylaminotoluene hydrochloride
5. 2-Amino-5-(N-ethyl-N-dodecylamino)-toluene
6. N-Ethyl-N-β-methanesulfonamidoethyl-3-methyl-4-aminoaniline sulfate
7. N-Methyl-N-β-methanesulfonamidoethyl-4-aminoaniline
8. 4-N-Ethyl-N-β-hydroxyethyl-aminoaniline
The developer solution may contain a sulfite, carbonate, bisulfite, bromide or iodide of an alkali metal. The photographic emulsion used in the present invention may have been chemically sensitized or may have been optically sensitized by means of a carbocyanine, merocyanine or the like dye, and may have been incorporated with ordinary photographic additives such as, for example, antifoggant, stabilizer, anti-stain agent, physical property-improving high molecular additive, hardener, coating aid, etc. When an ultraviolet absorber is incorporated into a light sensitive color photographic material containing the couplers used in the present invention, a color image obtained from the photographic material can further be enhanced in durability. Furthermore, the color developer solution may contain, in addition to the aforesaid developing agent, such a development controller as citrazinic acid or the like.
The accompanying drawing shows the spectral curves of the light-sensitive color photographic materials of the present invention which are described in Example 1 shown later.
The present invention is illustrated in further detail below with reference to examples, but it is needless to say that the scope of the invention is not limited to these.
EXAMPLE 1 PREPARATION OF SAMPLES 1 TO 5
Sample 1:
2.0 Grams of the exemplified coupler II-1 was dissolved at 60° C. in a mixed solvent comprising 2.0 ml. of dibutyl phthalate and 3.0 ml. of butyl acetate. The resulting solution was mixed with 10 ml. of a 10 percent aqueous solution of Alkanol B (alkylnaphthalene sulfonate produced by Du Pont) and 10 ml. of a 5 percent aqueous gelatin solution, and then subjected to a colloid mill to form a coupler dispersion. The thus formed coupler dispersion was added to 100 ml. of a red-sensitive high speed gelatin-silver iodobromide emulsion, which was then coated on a film base.
Sample 2:
2.0 Grams of the exemplified coupler I-1 was treated in the same manner as in the case of the sample 1.
Sample 3:
A mixture of 1.0 g. of the exemplified coupler I-1 and 1.0 g. of the exemplified coupler II-1 was treated in the same manner as in the case of the sample 1.
Sample 4:
A mixture of 1.6 g. of the exemplified coupler I-2 and 0.4 g. of the exemplified coupler III-2 was treated in the same manner as in the case of the sample 1.
Sample 5:
A mixture of 1.2 g. of the exemplified coupler I-1, 0.6 g. of the exemplified coupler II-3 and 0.4 g. of the exemplified coupler III-2 was dissolved in a mixed solvent comprising 2.5 ml. of dibutyl phthalate and 5.0 ml. of butyl acetate, and the resulting solution was treated in the same manner as in the case of the sample 1.
The above-mentioned samples were individually exposed according to an ordinary procedure and then developed at 20° C. for 10 minutes with a developer of the following composition:
N-Ethyl-N-β-methanesulfonamidoethyl-3-methyl-4-aminoani line 5.0 g. Anhydrous sodium sulfite 2.0 g. Benzyl alcohol 3.8 g. Sodium carbonate (monohydrate) 5.0 g. Potassium bromide 1.0 g. Caustic soda 0.55 g. Water to make 1,000 ml.
Subsequently, the developed samples were subjected to ordinary stop-fixing treatment, washed with water for 10 to 15 minutes, and then treated for 5 minutes with a bleaching solution of the following composition:
Potassium ferricyanide 100 g. Potassium bromide 50 g. Water to make 1,000 ml.
Thereafter, the samples were washed with water for 5 minutes and then dried. Photographic properties of the thus treated samples were as set forth in Table 1.
Table 1 ____________________________________________________________ ______________ Relative Gamma D-max Grainin- Sample speed (γ) ess ____________________________________________________________ ______________ 1 Exemplified 100 0.98 2.05 Relative- coupler II-1 ly fine 2 Exemplified 86 0.79 1.87 Fine coupler I-1 3 Exemplified coupler I-1 93 0.92 2.10 Fine do. II-1 14 Exemplified coupler I-2 90 0.91 1.74 Fine do. III-2 5 Exemplified coupler I-1 do. II-3 96 0.94 1.61 Fine do. III-2 ____________________________________________________________ ______________
Spectral curves of the samples 1, 3 and 5 were as shown in the accompanying drawing, in which the dotted line (.....), solid line (--) and chained line (.--.--) show the spectral curves of the samples 1, 3 and 5, respectively.
EXAMPLE 2
A high speed emulsion after completion of chemical ripening was subjected to optical sensitization by addition of a red-sensitive sensitizing dye 3,3'-diethyl-5,5'-dichloro-9-ethylthiacarbocyanine bromide. This emulsion was divided into three portions (each 100 ml. in amount) to prepare samples 1, 2 and 3. On the other hand, 2.0 g. of the exemplified coupler II-6, a mixture of 1.0 g. of the exemplified coupler I-3 and 1.0 g. of the exemplified coupler II-6, and a mixture of 1.0 g. of the exemplified coupler II-6, 0.8 g. of the exemplified coupler I-3 and 0.4 g. of the exemplified coupler III-2 were individually dissolved in a mixed solvent comprising 2.0 ml. of dibutyl phthalate and 6.0 ml. of butyl acetate, and then dispersed in the same manner as in Example 1 to prepare coupler dispersions (a), (b) and (c), respectively. The dispersion (a) was added to the sample 1, the dispersion (b) to the sample 2, and the dispersion (c) to the sample 3. Thereafter, the samples 1, 2 and 3 were treated in the same manner as in Example 1 to obtain the results as set forth in Table 2.
Table 2 ____________________________________________________________ ______________ Relative Gamma D-max Grainin- Sample speed (γ) ess ____________________________________________________________ ______________ 1 Exemplified 100 1.13 2.32 Relative- coupler II-6 ly fine 2 Exemplified coupler I-3 95 0.98 2.20 Fine do. II-6 3 Exemplified coupler I-3 do. II-6 92 0.94 2.14 Fine do. III-2 ____________________________________________________________ ______________
As is clear from Table 2, the samples according to the present invention are favorable in control of gamma and in graininess, and are excellent as lightsensitive color photographic materials.