Title:
COLOR PHOTOGRAPHIC DEVELOPMENT UTILIZING PYRAZOLONE COUPLERS
United States Patent 3615502
Abstract:
In a color photographic developing process, the use of a coupler of the formula wherein R is methyl or methoxy.
US Patent References:
Pyrazolone coupler for color photography
Porter et al. - February 1943 - 2311082
/3127269.html
Greenhalgh et al. - March 1964 - 3127269
Magenta-forming couplers
Tuite - October 1964 - 3152896
Pyrazolone coupler for color photography
Porter et al. - February 1943 - 2311082
/3127269.html
Greenhalgh et al. - March 1964 - 3127269
Magenta-forming couplers
Tuite - October 1964 - 3152896
Application Number:
05/024250
Publication Date:
10/26/1971
Filing Date:
03/31/1970
View Patent Images:
Export Citation:
Assignee:
Fuji Photo Film Co., Ltd. (Kanagawa, JA)
Primary Class:
Other Classes:
548/368.700, 430/554, 430/474, 430/386
International Classes:
C07D231/52; G03C7/384; C07D231/00; G03C7/38; G03C7/00
Field of Search:
96/56.5,100
Primary Examiner:
Brown, Travis J.
Claims:
What is claimed is
1. A silver halide color photographic developing process which comprises color developing an exposed silver halide image using a solution containing an aromatic primary amino developing agent and couple of the formula
2. The color photographic developing process of claim 1 wherein said coupler is 1-(2,6-dichloro-4-methylphenyl)-3-(4-nitroanilino)-5-pyrazolone.
3. The color photographic developing process of claim 1 wherein said coupler is 1-(2,6-dichloro-4-methoxy-phenyl)-3-(4-nitro-anilino)-5-pyrazolone.
4. A color photographic developer comprising an aromatic amino developing agent and a compound of the formula
5. The color photographic developer of claim 4 wherein said compound is 1-(2,6-dichloro-4-methylphenyl)-3-(4-nitroanilino)-5-pyrazolone.
6. The color photographic developer of claim 4 wherein said compound is 1-(2,6-dichloro-4-methoxy-phenyl)-3-(4-nitro-anilino)-5-pyrazolone.
1. A silver halide color photographic developing process which comprises color developing an exposed silver halide image using a solution containing an aromatic primary amino developing agent and couple of the formula
2. The color photographic developing process of claim 1 wherein said coupler is 1-(2,6-dichloro-4-methylphenyl)-3-(4-nitroanilino)-5-pyrazolone.
3. The color photographic developing process of claim 1 wherein said coupler is 1-(2,6-dichloro-4-methoxy-phenyl)-3-(4-nitro-anilino)-5-pyrazolone.
4. A color photographic developer comprising an aromatic amino developing agent and a compound of the formula
5. The color photographic developer of claim 4 wherein said compound is 1-(2,6-dichloro-4-methylphenyl)-3-(4-nitroanilino)-5-pyrazolone.
6. The color photographic developer of claim 4 wherein said compound is 1-(2,6-dichloro-4-methoxy-phenyl)-3-(4-nitro-anilino)-5-pyrazolone.
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to color photography and more particularly to a color developer containing an improved coupler.
2. Description of the Prior Art
It is well known to use a coupler in a color photographic development, whereby a color image is formed by the reaction of such coupler with the oxidation product of an aromatic primary amine developing agent and many patents have been granted on such couplers, as well as on color photographic development processes using such couplers. Such a coupler reacts with the oxidation product of a developing agent to form a dye insoluble in an ordinary developing solution, whereby a color image is left in the photographic emulsion layer. There are two types of such couplers. The first is a coupler which is incorporated into a developer. The second is a coupler which is incorporated into a photographic emulsion layer prior to the exposure of the layer.
Such color development is generally performed by a subtractive color process, and couplers that form cyan, magenta, and yellow dyes are employed in the color development. Further it is necessary in color development processes, to employ couplers which form dyes having desirable hues and transparencies.
Among such, the magenta-forming coupler is ideally required to form a dye having such a color hue that it completely absorbs green light but is completely transparent to both blue and red light. Moreover, to improve the transparency of the color image and to prevent the formation of a rough-appearing image, it is desirable that the granularity of the dye particles formed be fine and the granularity contrast be low. This is particularly important in order to improve the sharpness of the image. It is further necessary that the dye formed be stable to heat, moisture, etc., and, in particular, it is most important that the dye possess excellent stability in the presence of light.
As couplers satisfying the above factors, there are known such derivatives as cyanoacetylcumarone, nitrophenylacetonitrile, indazolone, pyrazolone, and the like. Among them, it is well known that 1-phenyl-3-amino-5-pyrazolone derivatives having more than one halogen atom on the 1-phenyl group form a sharp magenta dye possessing excellent color hue and also that such pyrazolone derivatives having a nitroanilino group in the 3-position form a magenta dye having a high color density, as disclosed in British Patent No. 886,723, U.S. Pat. No. 3,152,896, British Patent No. 956,261, and Belgian Patent No. 682,384, of appliant.
For example, British Patent No. 886,723, specifically discloses the use of 1-(2,4,6-trichlorophenyl)-3-(4-nitroanilino)-5-pyrazolone. U.S. Pat. No. 3,152,896 relates to the use of 1-(2,6-dichloro-4-negative group-substituted phenyl)-3-anilino-5-pyrazolone. British Patent No. 956,261 relates to the use of 1-aryl-3-(2-substituted anilino)-5-pyrazolone. Furthermore, Belgian Patent No. 682,384 is concerned with the use of 1-(2,5-dichlorophenyl)-3-(4-nitroanilino)-5-pyrazolone.
However, the above-mentioned requirements are not sufficiently satisfied even by such couplers and hence it has been desired to discover improved magenta couplers for use in color development.
Thus, an object of the present invention is to provide a color developer containing a magenta coupler which produces a dye having excellent light fastness and excellent granularity.
Another object of the present invention is to provide a color developer containing an improved coupler capable of forming a magenta dye having excellent color hue and a magenta image sufficiently satisfying the aforesaid requirements.
A further object of the present invention is to provide an improved magenta coupler to be used in a color developer for providing a magenta image sufficiently satisfying the aforesaid requirements.
SUMMARY OF THE INVENTION
The above objects may be attained by using, as such magenta coupler, a 1-(2,6-dichloro-4-positive group-substituted phenyl)-3-(4-nitroanilino)-5-pyrazolone, which compounds are characterized by possessing a positive methyl or methoxy group in the 4-position of the 1-phenyl nucleus and also possessing chlorine atoms in the 2- and 6- positions thereof. That is to say, the magenta coupler of the instant invention is represented by the following general formula:
wherein R represents a member selected from the group consisting of a methyl group and a methoxy group.
These couplers of the present invention have excellent advantages as will be set forth below more fully.
BRIEF DESCRIPTION OF THE DRAWING
In FIGS. 1 and 2 of the accompanying drawings are shown the comparison between the spectral absorption curves E and F of color images formed by the coupling reaction of couplers A and B of the present invention and the oxidation product of a color developing agent, 2-methyl-4-N-ethyl-N-methanesulfoamino ethylamino aniline, according to the process shown in example 1 and the spectral absorption curves G and H of the color images obtained by that of the control couplers C and D and the oxidation product of the same color developing agent as above. The structural formulas of Couplers A and B of the present invention, as well as control Couplers C and D, are set forth below. ##SPC1##
DETAILED DESCRIPTION OF THE INVENTION
In table 1, below, are shown the maximum absorption wave length (λ max ) obtained from each spectral absorption curve, the widths at half absorption value Δλ 1 /2 S and Δλ 1 /2 L, which are the numerical values showing the sharpness of the absorption curve, and D 640 /Dλ max and D 450 /Dλ max (the numerical value obtained dividing the optical density at 640 n.m. or 450 n.m. by the maximum optical density) which are the numerical values showing unnecessary cyan and yellow components causing reduction in color hue. ##SPC2##
As shown by the spectral absorption curves of FIGS. 1 and 2, as well as table 1, the couplers A and B of the present invention have sharper absorption curves, less cyan and yellow components, and better absorption characteristics than the control coupler C or D. That is, as will be understood from table 1, the longer wave length side value Δλ 1 /2 L and the shorter wave length side value Δλ 1 /2 S are smaller in couplers A and B than in either of the control couplers C and D. Also, the values of D 640 /Dλ max and D 450 /Dλ max are much smaller in couplers A and B than in the control couplers C and D. As magenta is a color between cyan and yellow, it is required, from the view point of color reproduction for color photography, that the absorption curve thereof be sharp and to have as small as possible proportions of unnecessary cyan and yellow components. The magenta coupler of the present invention sufficiently fulfills these requirements and is therefore excellent in comparison with conventional couplers.
In order to demonstrate the finess of the dye particles in the color image obtained, it is useful to employ the value obtained by dividing Selwayn's granularity G (see E. W. H. Selwayn; "Photographic Journal"; 75, 571 (1935) and ibid.; 79, 513 (1939) by the coupling density of sample.
That is, the finer the granularity of the dye, the smaller is the ratio of these values. These ratios are shown for each of the color images corresponding to the spectral absorption curves of the accompanying drawings in table 2. ------------------------------------------------------------ --------------- ------------------------------------------------------------ --------------- TABLE 2 ------------------------------------------------------------ --------------- G/Coupling Density
Coupling density E F G H 0.3 0.31 0.31 0.35 0.36 0.6 0.42 0.41 0.45 0.45 1.2 0.45 0.44 0.50 0.49 ____________________________________________________________ ______________
from table 2, it will be understood that the granularity of the dye of the color image obtained from the coupler of the present invention is much finer than that obtained from the control coupler C or D. Thus, it is clear that, as the granularity of the dye becomes finer, the transparency of the dye image is improved, the formation of roughness in the color image is prevented, and the sharpness of color image is improved.
Also, each sample having the color image corresponding to the spectral absorption curve shown in the accompanying drawing was exposed for 50 hours to a XF-20 type xenon lamp Fade Tester manufactured by K .K. Shimazu Seisakusho and the fading of the color image was then measured. The results are shown in table 3, which shows that the color image obtained from the couplers of the present invention had better light fastness than those obtained from the control couplers. ------------------------------------------------------------ --------------- ------------------------------------------------------------ --------------- TABLE 3
Color image Percentage of Fade ____________________________________________________________ ______________ E 60% F 58% G 79% 75% ____________________________________________________________ ______________
although the mechanism by which the couplers of the present invention provide excellent, improved color hue, granularity, light fastness, etc., as compared with the known couplers is not known, it is considered to be probably mainly due to the fact that the 4-position of the 1-phenyl nucleus of the coupler has been substituted by the positive methyl group or methoxy group. However, such excellent coupling results cannot simply be obtained by replacing only one chlorine atom of the three chlorine atoms on the 1-phenyl nucleus as illustrated by those experiments using control coupler D. That is, control coupler D is similar to coupler B of this invention in that the 1-phenyl nucleus has two chlorine atoms and one methyoxy group, and the molecular formula and the molecular weight of these two couplers are completely the same. The difference between them is only in the positions of the two chlorine atoms. Thus, the mere difference in the positions of chlorine atoms is seen to produce a decisive change in the photographic properties of the coupler.
The coupler of the present invention can be used not only for natural color photography but also for monochromatic or dichromatic photography.
The couplers of the present invention may generally be prepared according to the processes disclosed in British Patent No. 886,723 or Belgian Patent No. 682,384. Examples of preparing the couplers of this invention are shown below:
SYNTHESIS EXAMPLE 1
Preparation of Coupler B
a): Preparation of 1-(2,6-dichloro-4-methoxyphenyl)-3-(4-nitrophenoxyacetoamido )-5-pyrazolone .
Into a 1 liter three-necked flask were charged 400 ml. of acetonitrile and 60 g. of 1-(2,6-dichloro-4-methoxyphenyl)-3-amino-5-pyrazolone (prepared by the method disclosed in U.S. Pat. No. 3,062,653). A solution of 56 g. of 4-nitrophenoxy-acetyl chloride in 200 ml. of acetonitrile was gradually added to the system and the resultant mixture was refluxed for about 3 hours. After distilling out about 400 ml. of acetonitrile under a reduced pressure, the reaction mixture was cooled by ice to precipitate crystals, which were collected by filtration and washed with acetonitrile, and then with methanol to give 75 g. (yield 80 percent) of white crystals having a melting point of 219°- 220° C. The analytical value for nitrogen was 12.50 percent (theoretical value 12.36 percent)
b): Preparation of 1-(2,6-dichloro-4-methoxyphenyl)- 3-(4-nitroanilino)-5-pyrazolone.
Into a solution of 21 g. of sodium hydroxide in 60 ml. of water and 240 ml. of ethanol was gradually added 79 g. of the product prepared in a) and the resultant mixture was stirred for about 8 hours at room temperature. The crystals deposited were filtered off, the filtrate was mixed with 400 ml. of water, and the mixture was acidified by the addition of glacial acetic acid. Crystals thus precipitated were collected by filtration, washed well with water, and then with methanol to give 60 g. (yield 87 percent) of the yellow crystals having a melting point of 281°- 282° C. The product dissolved in 120 ml. dimethylformamide and the resultant solution was mixed with 800 ml. of methanol to precipitate 54 g. of the pure product having a melting point of 283°- 284° C. with a yield of 78 percent. The analytical value for nitrogen was 14.36 (theoretical value 14.18 percent).
SYNTHESIS EXAMPLE 2
Preparation of Coupler A
a): Preparation of 1-(2,6-dichloro-4-methylphenyl)-3-amino-5-pyrazolone:
By hydrolyzing 2,6-dichloro-4-methylacetanilide (prepared by the method described in "Annalen del Chemie"; 231, 321), 2,6-dichloro-4-methylaniline was obtained. The methylaniline thus prepared was converted into 2,6-dichloro-4-methylphenyl hydrazine by diazotizing and reducing with tin chloride according to a conventional method. The yield was 62 percent, the melting point thereof was 98- 100° C., and the analytical value for nitrogen was 14.38 percent (theoretical value 14.66 percent).
By reacting the product prepared above and ethyl-β-imino-β-ethoxypropionate according to a conventional method of producing 1-aryl-3-amino-5-pyrazolones, the objective pyrazolone having a melting point of 216°-218° C. was obtained with a yield of 86 percent. The analytical value for nitrogen was 16.03 percent (theoretical value 16.28 percent).
b): Preparation of 1-(2,6-dichloro-4-methylphenyl)-3-(4-nitrophenoxyacetamido)- 5-pyrazolone.
By following the same procedure as in synthesis example 1 a), using the material prepared in a) of this example, the product having a melting point of 233°-234° C. was obtained with a yield of 78 percent. The analytical value for nitrogen was 12.57 percent (theoretical value 12.81 percent).
c): Preparation of 1-(2,6-dichloro-4-methylphenyl)-3-(4-nitroanilino)-5-pyrazol one. By following the same procedure as in synthesis example 1 b), using the material prepared in b) of this example, yellow crystals having a melting point of 266°-267° C. were obtained with a yield of 65 percent. The analytical value for nitrogen was 14.71 percent (theoretical value 14.77 percent).
SYNTHESIS EXAMPLE 3
Preparation of the Control Coupler D
a): Preparation of 1-(3,5-dichloro-4-methoxyphenyl)-b 3-(4-phenoxyacetamido)-5-pyrazolone.
By following the procedure of synthesis example 1 a), but using 1-(3,5-dichloro-4-methoxyphenyl)-3-amino-5-pyrazolone having a melting point of 173°-174° C., a product having a melting point of 210°-212° C. was obtained with a yield of 67 percent. The analytical value for nitrogen was 12.58 percent (theoretical value 12.36 percent).
b): Preparation of 1-(3,5-dichloro-4-methoxyphenyl)-3-(4-nitro nitroanilino)-5-pyrazolone.
The same procedure as in synthesis example 1 b) was followed, but using the material obtained in a) of this example to give yellow-brown crystals having a melting point of 253°-254° C. with a yield of 74 percent. The analytical value for nitrogen was 13.92 percent (theoretical value 14.18 percent).
The present invention will now be explained in more detail by the following illustrative examples.
EXAMPLE 1
A photographic light-sensitive film prepared by applying an ordinary green-sensitive silver iodobromide emulsion to a film and drying was exposed to green light using a stage-type wedge. After developing the exposed film in a black and white developer for 3 minutes, the film was subjected to reversal exposure with green light, developed for 5 minutes in a magenta developer containing the Coupler A of the present invention, and washed with water.
The developed film was subjected to silver bleaching by an ordinary process and fixed in a hypo-containing fixer, whereby a positive magenta image having excellent transparency was obtained. The spectral absorption curve of the color image is shown as curve E in the accompanying drawing.
The compositions of the black and white developer and the magenta developer were as follows;
Black and white developer ____________________________________________________________ ______________ N-methyl-p-aminophenol 1/2 sulfate 4,5 g. Sodium sulfite 70 g. Hydroquinone 8 g. Sodium Carbonate (monohydrate) 20 g. Potassium bromide 2.5 g. Water to make 1 1. Magenta developer ____________________________________________________________ ______________ Potassium bromide 3 g. Sodium sulfite 10 g. Sodium sulfate 50 g. Potassium thiocyanate 1 g. Sodium hydroxide 3 g. 1-(2,6-dichloro-4-methylphenyl)-3-(4-nitroanilino)-5-pyrazol one 2 g. Hexylene glycol 10 ml. 2-methyl-4-N-ethyl-N-methane-sulfoaminoethylaminoaniline 3/2 sulfate (monohydrate) 2 g. Water to make 1 l. ____________________________________________________________ ______________
EXAMPLE 2
By following the same procedure as in example 1, but using coupler B, (1-(2,6-dichloro-4-methoxyphenyl)-3-(4-nitroanilino)-5-pyraz olone), a positive magenta image having excellent transparency was obtained. The spectral absorption curve of the color image is shown as the curve F in the accompanying drawing.
EXAMPLE 3
By following the same procedure as in example 1, but using a magenta developer having the following composition instead of the developer of example 1, a positive magenta image having excellent transparency and λ max at 545 m μ was obtained.
Magenta developer ____________________________________________________________ ______________ Potassium bromide 2 g. Sodium sulfite 10 g. Sodium carbonate (monohydrate) 23 g. Sodium hydroxide 1.5 g. 1-(2,6-dichloro-4-methylphenyl)-b 3-(4-nitroanilino)-5-pyrazolone 1.5g. Hexylene glycol 10 ml. 2-methyl-4-N,N-diethylaminoaniline hydrochloride 3 g. Water to make 1 1. ____________________________________________________________ ______________
EXAMPLE 4
A multilayer reversal color photographic film of a type to be developed in color developers containing couplers was exposed, developed for 3 minutes in the black and white developer of example 1, washed with water, subjected to reversal exposure with red light, and developed for 4 minutes in a cyan developer having the following composition.
Cyan Developer ____________________________________________________________ ______________ Potassium Bromide 2 g. Potassium thiocyanate 2 g. Sodium sulfite 5 g. Sodium hydroxide 2 g. 2-(2-propiamido-β-phenylethyl)-1-hydroxyanaphthamide 3 g. Hexylene glycol 10 ml. ____________________________________________________________ ______________
2-methyl-4-N,N-diethylaminoaniline hydrochloride 1.5 g. Monobenzyl-p-aminophenol 0.4 g. Methanol 5 ml. Water to make 1 1. ____________________________________________________________ ______________
The developed film was washed with water, exposed to blue light, and then developed for 4 minutes in a yellow developer having the following composition;
Yellow developer ____________________________________________________________ ______________ Potassium bromide 2 g. Sodium sulfite 5 g. Sodium hydroxide 2 g. Benzoylacetanilide 1.5 g. 4-N,N-diethylaminoaniline sulfate 2 g. Water to make 1 1. ____________________________________________________________ ______________
After washing with water, the film was then developed for 2 minutes in the black and white developer described above and washed with water. Thereafter, the film was exposed to white light and developed for 4 minutes in a magenta developer having the following composition;
Magenta developer ____________________________________________________________ ______________ Potassium bromide 2 g. Sodium sulfite 5 g. Sodium hydroxide 2 g. 1-(2,6-dichloro-4-methoxyphenyl)- 3-(4-nitroanilino)-5-pyrazolone 1.5 g. 1-methyl-4-N,N-diethylaminoaniline hydrochloride 1.5 g. Water to make 1 l. ____________________________________________________________ ______________
After washing with water, the film was subjected to silver bleaching by an ordinary process and fixed in a hypo-containing fixer to give a color photographic image having excellent transparency.
1. Field of the Invention
The present invention relates generally to color photography and more particularly to a color developer containing an improved coupler.
2. Description of the Prior Art
It is well known to use a coupler in a color photographic development, whereby a color image is formed by the reaction of such coupler with the oxidation product of an aromatic primary amine developing agent and many patents have been granted on such couplers, as well as on color photographic development processes using such couplers. Such a coupler reacts with the oxidation product of a developing agent to form a dye insoluble in an ordinary developing solution, whereby a color image is left in the photographic emulsion layer. There are two types of such couplers. The first is a coupler which is incorporated into a developer. The second is a coupler which is incorporated into a photographic emulsion layer prior to the exposure of the layer.
Such color development is generally performed by a subtractive color process, and couplers that form cyan, magenta, and yellow dyes are employed in the color development. Further it is necessary in color development processes, to employ couplers which form dyes having desirable hues and transparencies.
Among such, the magenta-forming coupler is ideally required to form a dye having such a color hue that it completely absorbs green light but is completely transparent to both blue and red light. Moreover, to improve the transparency of the color image and to prevent the formation of a rough-appearing image, it is desirable that the granularity of the dye particles formed be fine and the granularity contrast be low. This is particularly important in order to improve the sharpness of the image. It is further necessary that the dye formed be stable to heat, moisture, etc., and, in particular, it is most important that the dye possess excellent stability in the presence of light.
As couplers satisfying the above factors, there are known such derivatives as cyanoacetylcumarone, nitrophenylacetonitrile, indazolone, pyrazolone, and the like. Among them, it is well known that 1-phenyl-3-amino-5-pyrazolone derivatives having more than one halogen atom on the 1-phenyl group form a sharp magenta dye possessing excellent color hue and also that such pyrazolone derivatives having a nitroanilino group in the 3-position form a magenta dye having a high color density, as disclosed in British Patent No. 886,723, U.S. Pat. No. 3,152,896, British Patent No. 956,261, and Belgian Patent No. 682,384, of appliant.
For example, British Patent No. 886,723, specifically discloses the use of 1-(2,4,6-trichlorophenyl)-3-(4-nitroanilino)-5-pyrazolone. U.S. Pat. No. 3,152,896 relates to the use of 1-(2,6-dichloro-4-negative group-substituted phenyl)-3-anilino-5-pyrazolone. British Patent No. 956,261 relates to the use of 1-aryl-3-(2-substituted anilino)-5-pyrazolone. Furthermore, Belgian Patent No. 682,384 is concerned with the use of 1-(2,5-dichlorophenyl)-3-(4-nitroanilino)-5-pyrazolone.
However, the above-mentioned requirements are not sufficiently satisfied even by such couplers and hence it has been desired to discover improved magenta couplers for use in color development.
Thus, an object of the present invention is to provide a color developer containing a magenta coupler which produces a dye having excellent light fastness and excellent granularity.
Another object of the present invention is to provide a color developer containing an improved coupler capable of forming a magenta dye having excellent color hue and a magenta image sufficiently satisfying the aforesaid requirements.
A further object of the present invention is to provide an improved magenta coupler to be used in a color developer for providing a magenta image sufficiently satisfying the aforesaid requirements.
SUMMARY OF THE INVENTION
The above objects may be attained by using, as such magenta coupler, a 1-(2,6-dichloro-4-positive group-substituted phenyl)-3-(4-nitroanilino)-5-pyrazolone, which compounds are characterized by possessing a positive methyl or methoxy group in the 4-position of the 1-phenyl nucleus and also possessing chlorine atoms in the 2- and 6- positions thereof. That is to say, the magenta coupler of the instant invention is represented by the following general formula:
wherein R represents a member selected from the group consisting of a methyl group and a methoxy group.
These couplers of the present invention have excellent advantages as will be set forth below more fully.
BRIEF DESCRIPTION OF THE DRAWING
In FIGS. 1 and 2 of the accompanying drawings are shown the comparison between the spectral absorption curves E and F of color images formed by the coupling reaction of couplers A and B of the present invention and the oxidation product of a color developing agent, 2-methyl-4-N-ethyl-N-methanesulfoamino ethylamino aniline, according to the process shown in example 1 and the spectral absorption curves G and H of the color images obtained by that of the control couplers C and D and the oxidation product of the same color developing agent as above. The structural formulas of Couplers A and B of the present invention, as well as control Couplers C and D, are set forth below. ##SPC1##
DETAILED DESCRIPTION OF THE INVENTION
In table 1, below, are shown the maximum absorption wave length (λ max ) obtained from each spectral absorption curve, the widths at half absorption value Δλ 1 /2 S and Δλ 1 /2 L, which are the numerical values showing the sharpness of the absorption curve, and D 640 /Dλ max and D 450 /Dλ max (the numerical value obtained dividing the optical density at 640 n.m. or 450 n.m. by the maximum optical density) which are the numerical values showing unnecessary cyan and yellow components causing reduction in color hue. ##SPC2##
As shown by the spectral absorption curves of FIGS. 1 and 2, as well as table 1, the couplers A and B of the present invention have sharper absorption curves, less cyan and yellow components, and better absorption characteristics than the control coupler C or D. That is, as will be understood from table 1, the longer wave length side value Δλ 1 /2 L and the shorter wave length side value Δλ 1 /2 S are smaller in couplers A and B than in either of the control couplers C and D. Also, the values of D 640 /Dλ max and D 450 /Dλ max are much smaller in couplers A and B than in the control couplers C and D. As magenta is a color between cyan and yellow, it is required, from the view point of color reproduction for color photography, that the absorption curve thereof be sharp and to have as small as possible proportions of unnecessary cyan and yellow components. The magenta coupler of the present invention sufficiently fulfills these requirements and is therefore excellent in comparison with conventional couplers.
In order to demonstrate the finess of the dye particles in the color image obtained, it is useful to employ the value obtained by dividing Selwayn's granularity G (see E. W. H. Selwayn; "Photographic Journal"; 75, 571 (1935) and ibid.; 79, 513 (1939) by the coupling density of sample.
That is, the finer the granularity of the dye, the smaller is the ratio of these values. These ratios are shown for each of the color images corresponding to the spectral absorption curves of the accompanying drawings in table 2. ------------------------------------------------------------ --------------- ------------------------------------------------------------ --------------- TABLE 2 ------------------------------------------------------------ --------------- G/Coupling Density
Coupling density E F G H 0.3 0.31 0.31 0.35 0.36 0.6 0.42 0.41 0.45 0.45 1.2 0.45 0.44 0.50 0.49 ____________________________________________________________ ______________
from table 2, it will be understood that the granularity of the dye of the color image obtained from the coupler of the present invention is much finer than that obtained from the control coupler C or D. Thus, it is clear that, as the granularity of the dye becomes finer, the transparency of the dye image is improved, the formation of roughness in the color image is prevented, and the sharpness of color image is improved.
Also, each sample having the color image corresponding to the spectral absorption curve shown in the accompanying drawing was exposed for 50 hours to a XF-20 type xenon lamp Fade Tester manufactured by K .K. Shimazu Seisakusho and the fading of the color image was then measured. The results are shown in table 3, which shows that the color image obtained from the couplers of the present invention had better light fastness than those obtained from the control couplers. ------------------------------------------------------------ --------------- ------------------------------------------------------------ --------------- TABLE 3
Color image Percentage of Fade ____________________________________________________________ ______________ E 60% F 58% G 79% 75% ____________________________________________________________ ______________
although the mechanism by which the couplers of the present invention provide excellent, improved color hue, granularity, light fastness, etc., as compared with the known couplers is not known, it is considered to be probably mainly due to the fact that the 4-position of the 1-phenyl nucleus of the coupler has been substituted by the positive methyl group or methoxy group. However, such excellent coupling results cannot simply be obtained by replacing only one chlorine atom of the three chlorine atoms on the 1-phenyl nucleus as illustrated by those experiments using control coupler D. That is, control coupler D is similar to coupler B of this invention in that the 1-phenyl nucleus has two chlorine atoms and one methyoxy group, and the molecular formula and the molecular weight of these two couplers are completely the same. The difference between them is only in the positions of the two chlorine atoms. Thus, the mere difference in the positions of chlorine atoms is seen to produce a decisive change in the photographic properties of the coupler.
The coupler of the present invention can be used not only for natural color photography but also for monochromatic or dichromatic photography.
The couplers of the present invention may generally be prepared according to the processes disclosed in British Patent No. 886,723 or Belgian Patent No. 682,384. Examples of preparing the couplers of this invention are shown below:
SYNTHESIS EXAMPLE 1
Preparation of Coupler B
a): Preparation of 1-(2,6-dichloro-4-methoxyphenyl)-3-(4-nitrophenoxyacetoamido )-5-pyrazolone .
Into a 1 liter three-necked flask were charged 400 ml. of acetonitrile and 60 g. of 1-(2,6-dichloro-4-methoxyphenyl)-3-amino-5-pyrazolone (prepared by the method disclosed in U.S. Pat. No. 3,062,653). A solution of 56 g. of 4-nitrophenoxy-acetyl chloride in 200 ml. of acetonitrile was gradually added to the system and the resultant mixture was refluxed for about 3 hours. After distilling out about 400 ml. of acetonitrile under a reduced pressure, the reaction mixture was cooled by ice to precipitate crystals, which were collected by filtration and washed with acetonitrile, and then with methanol to give 75 g. (yield 80 percent) of white crystals having a melting point of 219°- 220° C. The analytical value for nitrogen was 12.50 percent (theoretical value 12.36 percent)
b): Preparation of 1-(2,6-dichloro-4-methoxyphenyl)- 3-(4-nitroanilino)-5-pyrazolone.
Into a solution of 21 g. of sodium hydroxide in 60 ml. of water and 240 ml. of ethanol was gradually added 79 g. of the product prepared in a) and the resultant mixture was stirred for about 8 hours at room temperature. The crystals deposited were filtered off, the filtrate was mixed with 400 ml. of water, and the mixture was acidified by the addition of glacial acetic acid. Crystals thus precipitated were collected by filtration, washed well with water, and then with methanol to give 60 g. (yield 87 percent) of the yellow crystals having a melting point of 281°- 282° C. The product dissolved in 120 ml. dimethylformamide and the resultant solution was mixed with 800 ml. of methanol to precipitate 54 g. of the pure product having a melting point of 283°- 284° C. with a yield of 78 percent. The analytical value for nitrogen was 14.36 (theoretical value 14.18 percent).
SYNTHESIS EXAMPLE 2
Preparation of Coupler A
a): Preparation of 1-(2,6-dichloro-4-methylphenyl)-3-amino-5-pyrazolone:
By hydrolyzing 2,6-dichloro-4-methylacetanilide (prepared by the method described in "Annalen del Chemie"; 231, 321), 2,6-dichloro-4-methylaniline was obtained. The methylaniline thus prepared was converted into 2,6-dichloro-4-methylphenyl hydrazine by diazotizing and reducing with tin chloride according to a conventional method. The yield was 62 percent, the melting point thereof was 98- 100° C., and the analytical value for nitrogen was 14.38 percent (theoretical value 14.66 percent).
By reacting the product prepared above and ethyl-β-imino-β-ethoxypropionate according to a conventional method of producing 1-aryl-3-amino-5-pyrazolones, the objective pyrazolone having a melting point of 216°-218° C. was obtained with a yield of 86 percent. The analytical value for nitrogen was 16.03 percent (theoretical value 16.28 percent).
b): Preparation of 1-(2,6-dichloro-4-methylphenyl)-3-(4-nitrophenoxyacetamido)- 5-pyrazolone.
By following the same procedure as in synthesis example 1 a), using the material prepared in a) of this example, the product having a melting point of 233°-234° C. was obtained with a yield of 78 percent. The analytical value for nitrogen was 12.57 percent (theoretical value 12.81 percent).
c): Preparation of 1-(2,6-dichloro-4-methylphenyl)-3-(4-nitroanilino)-5-pyrazol one. By following the same procedure as in synthesis example 1 b), using the material prepared in b) of this example, yellow crystals having a melting point of 266°-267° C. were obtained with a yield of 65 percent. The analytical value for nitrogen was 14.71 percent (theoretical value 14.77 percent).
SYNTHESIS EXAMPLE 3
Preparation of the Control Coupler D
a): Preparation of 1-(3,5-dichloro-4-methoxyphenyl)-b 3-(4-phenoxyacetamido)-5-pyrazolone.
By following the procedure of synthesis example 1 a), but using 1-(3,5-dichloro-4-methoxyphenyl)-3-amino-5-pyrazolone having a melting point of 173°-174° C., a product having a melting point of 210°-212° C. was obtained with a yield of 67 percent. The analytical value for nitrogen was 12.58 percent (theoretical value 12.36 percent).
b): Preparation of 1-(3,5-dichloro-4-methoxyphenyl)-3-(4-nitro nitroanilino)-5-pyrazolone.
The same procedure as in synthesis example 1 b) was followed, but using the material obtained in a) of this example to give yellow-brown crystals having a melting point of 253°-254° C. with a yield of 74 percent. The analytical value for nitrogen was 13.92 percent (theoretical value 14.18 percent).
The present invention will now be explained in more detail by the following illustrative examples.
EXAMPLE 1
A photographic light-sensitive film prepared by applying an ordinary green-sensitive silver iodobromide emulsion to a film and drying was exposed to green light using a stage-type wedge. After developing the exposed film in a black and white developer for 3 minutes, the film was subjected to reversal exposure with green light, developed for 5 minutes in a magenta developer containing the Coupler A of the present invention, and washed with water.
The developed film was subjected to silver bleaching by an ordinary process and fixed in a hypo-containing fixer, whereby a positive magenta image having excellent transparency was obtained. The spectral absorption curve of the color image is shown as curve E in the accompanying drawing.
The compositions of the black and white developer and the magenta developer were as follows;
Black and white developer ____________________________________________________________ ______________ N-methyl-p-aminophenol 1/2 sulfate 4,5 g. Sodium sulfite 70 g. Hydroquinone 8 g. Sodium Carbonate (monohydrate) 20 g. Potassium bromide 2.5 g. Water to make 1 1. Magenta developer ____________________________________________________________ ______________ Potassium bromide 3 g. Sodium sulfite 10 g. Sodium sulfate 50 g. Potassium thiocyanate 1 g. Sodium hydroxide 3 g. 1-(2,6-dichloro-4-methylphenyl)-3-(4-nitroanilino)-5-pyrazol one 2 g. Hexylene glycol 10 ml. 2-methyl-4-N-ethyl-N-methane-sulfoaminoethylaminoaniline 3/2 sulfate (monohydrate) 2 g. Water to make 1 l. ____________________________________________________________ ______________
EXAMPLE 2
By following the same procedure as in example 1, but using coupler B, (1-(2,6-dichloro-4-methoxyphenyl)-3-(4-nitroanilino)-5-pyraz olone), a positive magenta image having excellent transparency was obtained. The spectral absorption curve of the color image is shown as the curve F in the accompanying drawing.
EXAMPLE 3
By following the same procedure as in example 1, but using a magenta developer having the following composition instead of the developer of example 1, a positive magenta image having excellent transparency and λ max at 545 m μ was obtained.
Magenta developer ____________________________________________________________ ______________ Potassium bromide 2 g. Sodium sulfite 10 g. Sodium carbonate (monohydrate) 23 g. Sodium hydroxide 1.5 g. 1-(2,6-dichloro-4-methylphenyl)-b 3-(4-nitroanilino)-5-pyrazolone 1.5g. Hexylene glycol 10 ml. 2-methyl-4-N,N-diethylaminoaniline hydrochloride 3 g. Water to make 1 1. ____________________________________________________________ ______________
EXAMPLE 4
A multilayer reversal color photographic film of a type to be developed in color developers containing couplers was exposed, developed for 3 minutes in the black and white developer of example 1, washed with water, subjected to reversal exposure with red light, and developed for 4 minutes in a cyan developer having the following composition.
Cyan Developer ____________________________________________________________ ______________ Potassium Bromide 2 g. Potassium thiocyanate 2 g. Sodium sulfite 5 g. Sodium hydroxide 2 g. 2-(2-propiamido-β-phenylethyl)-1-hydroxyanaphthamide 3 g. Hexylene glycol 10 ml. ____________________________________________________________ ______________
2-methyl-4-N,N-diethylaminoaniline hydrochloride 1.5 g. Monobenzyl-p-aminophenol 0.4 g. Methanol 5 ml. Water to make 1 1. ____________________________________________________________ ______________
The developed film was washed with water, exposed to blue light, and then developed for 4 minutes in a yellow developer having the following composition;
Yellow developer ____________________________________________________________ ______________ Potassium bromide 2 g. Sodium sulfite 5 g. Sodium hydroxide 2 g. Benzoylacetanilide 1.5 g. 4-N,N-diethylaminoaniline sulfate 2 g. Water to make 1 1. ____________________________________________________________ ______________
After washing with water, the film was then developed for 2 minutes in the black and white developer described above and washed with water. Thereafter, the film was exposed to white light and developed for 4 minutes in a magenta developer having the following composition;
Magenta developer ____________________________________________________________ ______________ Potassium bromide 2 g. Sodium sulfite 5 g. Sodium hydroxide 2 g. 1-(2,6-dichloro-4-methoxyphenyl)- 3-(4-nitroanilino)-5-pyrazolone 1.5 g. 1-methyl-4-N,N-diethylaminoaniline hydrochloride 1.5 g. Water to make 1 l. ____________________________________________________________ ______________
After washing with water, the film was subjected to silver bleaching by an ordinary process and fixed in a hypo-containing fixer to give a color photographic image having excellent transparency.