Process For Forming Cyan Image In Light-sensitive Color Photographic Material

Abstract

A process for forming a cyan image in a light-sensitive color photographic material, characterized in that a light-sensitive color photographic material having a silver halide emulsion layer incorporated with a compound of the formula ##SPC1## Wherein A is a cyan image-forming coupler residue having an .alpha.-naphthol or phenol nucleus; ##SPC2## Is a group bonded to the P-position of the hydroxyl group of A; and Z is an atomic group necessary for forming an indazolyl group, is exposed to light imagewise and subjected to color development, or a light-sensitive color photographic material is exposed to light imagewise and subjected to color development using a color developer incorporated with the compound of the above-mentioned formula, thereby forming a cyan image corresponding to the silver image formed in the photographic material.

Description

This invention relates to a process for forming a cyan image in a light-sensitive color photographic material. More particularly, the invention is concerned with a process for forming a cyan dye image in a light-sensitive color photographic material using a two-equivalent cyan dye image-forming coupler.

A photographic process, in which a photographic material containing couplers is exposed and then developed with a developer containing an aromatic primary amine type developing agent to form a dye image, has already been well known. Among the couplers used in the above process, the cyan coupler, which forms an indoaniline dye by coupling with the oxidation product of the aromatic primary amine type developing agent, is a phenol or 1-naphthol derivative. In case the 4-position of said phenol or 1-naphthol derivative has not been substituted, 4 molecules of silver halide is required to form 1 molecule of dye. Thus, the said coupler is called a four-equivalent coupler.

However, it is also well known that a coupler, in which the hydrogen in the 4-position has been substituted by a halogen atom such as chlorine can also form the same dye as in the case of the four-equivalent coupler. In this case, the halogen atom is released during the course of color development, and 1 molecule of dye can be formed from 2 molecules of developed silver halide. Accordingly, the said coupler is called a two-equivalent coupler.

The two-equivalent coupler is more excellent than the four-equivalent coupler in the following points:

1. The two-equivalent coupler is higher in coupling reactivity than the known four-equivalent coupler.

2. The amount of silver halide required for forming a definite amount of dye may be one half of the amount required in the case of the four-equivalent coupler, so that the cost can be reduced.

3. The emulsion layer can be made thinner, so that the resulting color image is enhanced in resolution and sharpness.

4. In the case of a multi-layered photographic material, the transmission of light into the lower layers is improved, so that the sensitivity of the photographic material is enhanced.

Accordingly, the use of the two-equivalent coupler results in many advantages in forming a color image in a multi-layered light-sensitive color photographic material.

The above-mentioned excellent properties become particularly marked when the hydrogen in the 4-position of the cyan coupler (hydrogen in the coupling position) has been substituted by an indazolyl group such as ##SPC3## .

This substituent has the property of being released at the time of color development.

Some two-equivalent couplers tend to form color stains and have the property of inhibiting the development. However, the two-equivalent couplers used in the present invention are colorless and scarcely form stains. Further, cyan dyes obtained by color development from the cyan couplers used in the present invention are not only high in fastness to light, humidity and heat but also sharp in absorption and have an extremely desirable hue for color reproduction. Certain couplers used in the present invention can act as the so-called DIR (development inhibitor-releasing type) couplers which release a substance inhibiting the development at the time of color development.

The couplers used in the present invention are two-equivalent couplers having the formula, ##SPC4##

wherein A is a residue of a cyan image-forming coupler having an .alpha.-naphthol or phenol nucleus from which has been removed the hydrogen in the p-position to the hydroxyl group thereof; and Z is an atomic group necessary for forming an indazolyl group.

Typical examples of the couplers used in the present invention are shown below, but couplers usable in the present invention are not limited only to these.

1. 1-Hydroxy-4-(2'-indazolyl)-N-[.delta.(2,4-di-tert-amylphenoxy)-butyl]-2-na phthamide ##SPC5##

2. 1-Hydroxy-4-[2'-(5-chloroindazolyl)]-N-(n-dodecyl)-2-naphthamide ##SPC6##

3. 1-Hydroxy-4-[2'-(6-nitroindazolyl)]-N-[.delta.(2,4-di-tert-amylphenoxy)-bu tyl]-2-naphthamide ##SPC7##

4. 1-Hydroxy-4-[2'-(6-aminoindazolyl)]-N-[.delta.(2,4-di-tert-amylphenoxy)-bu tyl]-2-naphthamide ##SPC8##

5. 1-Hydroxy-4-[2'-(6-acetaminoindazolyl)]-N-[.delta.(2,4-di-tert-amylphenoxy )-butyl]-2-naphthamide ##SPC9##

6. 1-Hydroxy-4-[2'-(6-chloroindazolyl)]-4'-(4-tert-butylphenoxy)-2-naphthanil ide ##SPC10##

7. 1-Hydroxy-4-[2'-(6-nitroindazolyl)]-N-(n-dodecyl)-2-naphthamide ##SPC11##

8. 1-Hydroxy-4-[2'-(5-chloroindazolyl)]-N-(2'-ethylhexyl)-naphthamide ##SPC12##

9. 1-Hydroxy-4-( 2'-indazolyl)-4'-(4-tert-butylphenxoy)-2-naphthanilide ##SPC13##

10. 1-Hydroxy-4-(2'-indazolyl)-N-(n-octadecyl)-2-naphthamide ##SPC14##

These compounds can easily be obtained by synthesizing a colored cyan from a corresponding 1-naphthol type coupler and 2-aminobenzyl alcohol, and heating the colored cyan in 50 percent H.sub.2 SO.sub.4.

Typical synthesis examples are set forth below.

SYNTHESIS EXAMPLE 1

Synthesis of 1-hydroxy-4-(2'-indazolyl)-N-[.delta.-(2,4-di-tert-aminophenoxy)-butyl]-2- naphthamide

[Exemplified coupler (1)]:

a. Synthesis of 1-hydroxy-2-(2-hydroxymethyl-phenylazo)-N-[.delta.-(2,4-di-tert-amylphenox y)-butyl]-2-naphthamide:

Into a solution of 20 g. of 2-aminobenzyl alcohol in 250 ml. of 10 percent hydrochloric acid was dropped with stirring at 0.degree. to 5.degree. C. a solution of 10.5 g. of sodium nitrate in 75 ml. of water to prepare a diazonium salt solution. This solution was dropped with stirring at 20.degree. to 25.degree. C. into a solution of 60 g. of 1-hydroxy-N-[.delta.-(2,4-di-tert-amylphenoxy)-butyl]-2-naphthamide in 1.2 liters of pyridine, and the mixed solution was stirred at said temperature for 2 hours. The reaction mixture was poured into an aqueous hydrochloric acid solution and then extracted with ethyl acetate. Subsequently, the ethyl acetate was removed by distillation, and the residue was recrystallized from a mixture of ethyl acetate and n-hexane to obtain the desired compound, m.p. 122.degree.-125.degree. C., yield 65 g.

b. Synthesis of 1-hydroxy-4-(2'-indazolyl-N-[.delta.-(2,4-di-tert-amylphenoxy)-butyl]-2-na phthamide:

50 Grams of the 1-hydroxy-4-(2-hydroxy-methylphenylazo)-N-[ .delta.-(2,4-di-tert-amylphenoxy)-butyl]-2-naphthamide obtained in (a) was added to 800 ml. of 50 percent sulfuric acid, and the resulting mixture was heated with stirring over a water bath (80.degree.-90.degree. C.) for 2 hours. The reaction mixture was poured into ice water and then extracted with ethyl acetate. Subsequently, the ethyl acetate was removed by distillation, and the residue was recrystallized from alcohol to obtain the desired compound, yield 32 g., m.p. 225.degree.-227.degree. C.

Elementary analysis:

C(%) H(%) N(%) Calculated 71.86 6.96 6.45 Found 71.61 7.15 6.12 SYNTHESIS EXAMPLE 2

Synthesis of 1-hydroxy-4-[2'-(5-chloroindazolyl)]-N-(n-dodecyl)-2-naphthamide [Exemplified coupler (2)]:

a. Synthesis of 1-hydroxy-4-(2-hydroxymethyl-4-chlorophenylazo)-N-(n-dodecyl-2-naphthamide :

To a solution of 16 g. of 2-amino-5-chlorobenzyl alcohol in 250 ml. of hydrochloric acid was added with stirring at 0.degree. to 5.degree. C. a solution of 8 g. of sodium nitrate in 50 ml. of water. This solution was dropped at 15.degree. to 20.degree. C. into a solution of 55 g. of 1-hydroxy-N-(n-dodecyl)-2-naphthamide in 1 liter of pyridine, and then the mixed solution was stirred at room temperature for 2 hours. The reaction mixture was poured into an aqueous hydrochloric acid solution and extracted with ethyl acetate. Subsequently, the ethyl acetate was removed by distillation, and the residue was recrystallized from methanol to obtain the desired compound, yield 50 g., m.p. 137.degree.-138.degree. C.

b. Synthesis of 1-hydroxy-4-[2'-(5-chloroindazolyl)]-N-(n-dodecyl)-2-naphthamide:

40 Grams of the 1-hydroxy-4-(2'-hydroxymethyl-4-chlorophenylazo)-N-(n-dodecyl)-2-naphthami de obtained in (a) was added to 600 ml. of 50 percent sulfuric acid, and the resulting mixture was heated with stirring over a water bath for 2.5 hours. Thereafter, the reaction mixture was poured into ice water and extracted with ethyl acetate. The ethyl acetate was removed by distillation, and the residue was recrystallized from alcohol to obtain the desired compound, yield 23 g.

Elementary analysis:

C(%) H(%) N(%) Calculated 71.19 7.17 8.31 Found 71.07 7.14 8.56 SYNTHESIS EXAMPLE 3

Synthesis of 1-hydroxy-4-[2'-(6-aminoindazolyl)]-N-[.delta.-(2,4-di-tert-aminophenoxy)- butyl]-2-naphthamide [Exemplified coupler (4)] :

A solution of 20 g. of 1-hydroxy-4-[2'-(6-nitroimidazolyl)]-N-[.delta.-(2,4-di-tert-amylphenoxy)- butyl]-2-naphthamide in 500 ml. of 90 percent acetic acid was heated with stirring at 90.degree. to 100.degree. C. To this solution was added 7.5 g. of iron powder at an elevated temperature, and the resulting mixture was stirred as it was for 30 minutes. After cooling the reaction mixture, insolubles were removed by filtration, and the filtrate was poured into water to deposit crystals. The crystals were recovered by filtration and then recrystallized from methanol to obtain the desired compound, yield 12 g.

Elementary analysis:

C(%) H(%) N(%) Calculated 75.21 7.64 9.23 Found 75.46 7.38 9.20

The exemplified compound (5) is obtained by acetylating the exemplified compound (4) according to an ordinary procedure. Other compounds are obtained according to the same procedure as in the abovementioned synthesis examples.

For incorporation of the thus obtained couplers into light-sensitive color photographic materials, there may be adopted any of the known procedures. For example, one or two or more of the couplers are dissolved in a high boiling solvent having a boiling point of more than 175.degree. C., such as tricresyl phosphate or dibutyl phthalate, or in a low boiling solvent such as butyl acetate or butyl propionate (either alone or in the form of a mixture), and the resulting solution is mixed with an aqueous gelatin solution containing a surface active agent, and then subjected to a high speed rotary mixer or a colloid mill to form a coupler dispersion. Thereafter, the dispersion is added directly to a silver halide photographic emulsion, which is then coated on a support, followed by drying. Alternatively, the said dispersion is set, finely cut, freed from the low boiling solvent by water-washing or the like means, and added to a photographic emulsion, which is then coated on a support, followed by drying. In this case, the amount of the coupler to be added to the photographic emulsion is preferably in the range from 10 to 300 g. per mole of silver halide, but may be varied depending on the application purpose of the resulting photographic material.

The photographic emulsions used in the present invention may be prepared by use of various silver halides such as silver chloride, silver iodobromide and silver chlorobromide. These emulsions may contain chemical sensitizers, e.g. sulfur sensitizers, such natural sensitizer as present in gelatin, reduction sensitizers and noble metal salts. Further, the emulsions may have been incorporated with ordinary photographic additives such as, for example, antifoggants, stabilizers, anti-stain agents, anti-irradiation agents, physical property-improving high polymer additives, hardeners and coating aids, and may contain as known carbocyanine dye, merocyanine dye, etc. as optical sensitizers for the emulsions.

The present invention is illustrated in detail below with reference to examples, but it is needless to say that the invention is not limited to these.

EXAMPLE 1

2.0 Grams of the exemplified coupler (1) was dissolved in a mixed solvent comprising 2 ml. of dibutyl phthalate and 6 ml. of ethyl acetate. The resulting solution was mixed with 40 ml. of a 6 percent aqueous gelatin solution and 6 ml. of a 5 percent aqueous solution of Alkanol B (produced by Du Pont), and the mixed solution was subjected to ordinary protect dispersion method using a colloid mill to form a coupler dispersion. This dispersion was added to a silver iodobromide emulsion containing 5 g. of silver halide particles, and then the emulsion was coated on a triacetate base and dried to prepare a sample.

For comparison, a control sample was prepared in the same manner as above by use of a coupler identical in structure, except its having no indazolyl substituent, with the exemplified coupler (1).

The thus prepared samples were individually exposed according to an ordinary procedure and then developed at 24.degree. C. for 10 minutes with a developer of the following composition:

Anhydrous sodium sulfite 2.0 g. N-Ethyl-N-.beta.-methanesulfonamidoethyl- 5.0 g. 3-methyl-4-aminoaniline sulfate Sodium carbonate (monohydrate) 50.0 g Sodium bromide 0.9 g. Sodium hydroxide 4.0 g Sodium hexamethaphosphate 0.5 g. Benzyl alcohol 4.0 ml. Pure water to make 1,000 ml.

Subsequently, ordinary bleaching and fixing treatments were effected to obtain the results as set forth in Table 1.

TABLE 1

.lambda.-max Relative Coupler (m.mu.) D-max speed Fog Gamma Exemplified coupler (1) according to 690 3.5 130 0.09 2.2 the present invention Control coupler 690 2.8 100 0.11 2.0

As is clear from the results shown in Table 1, it is understood that the sample containing the exemplified coupler (1), despite its being less in emulsion fog, is more excellent in relative speed, gamma and D-max than the sample containing the control coupler, and thus the exemplified coupler (1) has prominent characteristics as a coupler bearing an indazolyl substituent.

Further, samples prepared by using each of the exemplified couplers (5), (9) and (10) in place of the exemplified coupler (1) were also less in emulsion fog and more excellent in relative speed, gamma and D-max than the sample containing the control coupler.

EXAMPLE 2

Samples were prepared in the same manner as in Example 1, except that 2.0 g. of the exemplified coupler (10) was used and the amount of silver iodobromide contained in the emulsion was varied to 1.25 g., 2.5 g. and 5.0 g.

For comparison, control samples were prepared in the same manner as above, except that a coupler identical in structure, except its having no indazolyl substituent, with the exemplified coupler (10) was used in such amounts as above.

These samples were exposed and then developed in the same manner as in Example 1 to obtain the results as set forth in Table 2.

TABLE 2

Amount of silver Relative Coupler halide(g) Fog speed Gamma Exemplified coupler (10) 5 0.13 135 2.3 according to the present 2.5 0.10 110 2.1 invention 1.25 0.08 107 2.0 Control 5 0.11 100 2.0 coupler 2.5 0.09 74 1.8 1.25 0.07 54 1.5

From Table 2, it is clear that even when the amount of silver halide is reduced to one fourth, the sample containing the exemplified coupler (10) is more excellent in characteristics than the control sample containing the control coupler, and thus the use of the coupler according to the present invention is extremely great in cost reduction effect.

EXAMPLE 3

A silver halide emulsion containing 5 g. of silver chlorobromide which had been incorporated with 2.0 g. of the exemplified coupler (10) was coated on a support to prepare a sample. This sample was exposed according to an ordinary procedure and then subjected to development. The developer used was identical in composition with that used in Example 1, except that the developing agent was vaired to N-methyl-p-phenylenediamine hydrochloride. After the development, the sample was sufficiently washed with water, dried and then treated under such conditions as shown below to obtain the results set forth in Table 3.

For comparison, a control sample was prepared in the same manner as above, except that the coupler used was a coupler identical in structure, except its having no indazolyl substitution, with the exemplified coupler (10), and then treated in the same manner as above to obtain the results as shown in Table 3. Treatment conditions:

Light fastness: Carbon arc lamp, 50.degree.C, 16 hrs., 32 hrs. Humidity and heat RH 80%, 77.degree.C. 7 days, fastness: 14 days.

TABLE 3

Light fastness Humidity and heat (fading ratio) fastness Coupler (fading ratio) 16 hr. 32 hr. 7 days 14 days Exemplified coupler 3 7 5 11 (10) Control 8 20 9 23 coupler Fading ratio: Fading (percent) after treating the portion where the initial density was 1.0.

As is clear from the results shown in Table 3, it is understood that the sample containing the coupler according to the present invention is more excellent in fastness to light, humidity and heat than the sample containing the control coupler.

EXAMPLE 4

A sample A was prepared in the following manner:

A mixture composed of 0.75 g. of the exemplified coupler (1), 0.75 g. of a coupler identical in structure, except its having no indazolyl substitution, with the exemplified coupler (1) and 0.5 g. of a colored coupler identical in nucleus with the exemplified coupler (1) (1-hydroxy-4-(2'-acetylphenylazo)-N[.delta.-(2,4-di-tert-amylphenoxy)-buty l]-2-naphthamide) was dissolved in a mixed solvent comprising 2 ml. of tricresyl phosphate and 7 ml. of ethyl acetate. The resulting solution was dispersed in 40 ml. of a 5 percent aqueous gelatin solution containing 4 ml. of a 5 percent aqueous sodium n-dodecylbenzenesulfonate solution. This dispersion was added to a red-sensitive photographic emulsion containing 5 g. of silver iodobromide, which was then coated on a cellulose triacetate base to a thickness of 5 microns and dried.

For comparison, a sample B was prepared in the same manner as above, except that 0.6 g. of a coupler identical in structure, except its having no indazolyl substitution, with the exemplified coupler (1) was used in place of the exemplified coupler (1).

The samples A and B were subjected to the same exposure and development treatments as in Example 1 to obtain the results set forth in Table 4.

TABLE 4

Fog Relative speed Gamma D-max Sample A 0.10 115 1.43 3.15 Sample B 0.11 100 1.44 2.88

From the results shown in Table 4, it is clear that even when used in admixture with couplers which are outside of the scope of the present invention, the coupler according to the present invention displays excellent characteristics. Accordingly, when the coupler according to the present invention is used in admixture with couplers which are outside of the scope of the present invention, the resulting photographic material can be controlled in speed, D-max and the like characteristics by merely varying the mixing ratio of the couplers, without varying the size or amount of silver halide particles.

EXAMPLE 5

A sample A was prepared in such a manner that a coupler mixture composed of 0.20 g. of the exemplified coupler (3) and 1.50 g. of a coupler identical in structure, except its having no indazolyl substitution, with the exemplied coupler (3) was dissolved in 10 ml. of a 1:3 solvent mixture of tricresyl phosphate and ethyl acetate, and the resulting solution was treated in the same manner as in the case of the sample A of Example 4.

For comparison, a sample B was prepared in the same manner as above, except that 1.65 g. of a coupler identical in structure, except its having no indazolyl substitution, with the exemplified coupler (3) was used in place of the coupler mixture.

The samples A and B were exposed according to an ordinary procedure, developed with the same developer as in Example 1, and then subjected to ordinary bleaching, fixing and water-washing treatments to obtain the results shown in the accompanying drawing which is a graph showing the density of cyan dye to red light at each stage described herein in which the horizontal axis represents the amount of exposure (log E) and the vertical axis the density of dye. As seen in the drawing, the sample A is longer in straight line portion of the characteristic curve and somewhat lower in gamma than the sample B, but it is understood that the sample A is entirely free from such detrimental effects as desensitization and the like, and is markedly effective as a socalled DIR (development inhibitor-releasing type) coupler.

Claims

What we claim is:

1. A process for forming a cyan image in a light-sensitive color photographic material, characterized in that a light-sensitive color photographic material having a silver halide emulsion layer incorporated with a compound of the formula ##SPC15##

wherein A is a cyan image-forming coupler residue having an .alpha.-naphthol or phenol nucleus; ##SPC16##

is a group bonded to the p-position of the hydroxyl group of A; and Z is an atomic group necessary for forming an indazolyl group, is exposed to light imagewise and subjected to color development, or a light-sensitive color photographic material is exposed to light imagewise and subjected to color development using a color developer incorporated with the compound of the abovementioned formula, thereby forming a cyan image corresponding to the silver image formed in the photographic material.

2. A process for forming a cyan image in a light-sensitive color photographic material as claimed in claim 1, wherein said compound is represented by the formula ##SPC17##

wherein Z is taken same as in the above and R is alkyl, aryl or a group ##SPC18##

in which R.sub.2 is hydrogen or alkyl, m is a positive integer up to four and n is a positive integer up to two.

3. A process for forming a cyan image in a light-sensitive color photographic material as claimed in claim 1, wherein said compound is selected from the group consisting of:

1-hydroxy-4-(2'-indazolyl)-N-[.delta.(2,4-di-tert-amylphenoxy)-butyl]-2-nap hthamide;

1-hydroxy-4-[2'-(5-chloroindazolyl)]-N-(n-dodecyl)-2-naphthamide;

1-hydroxy-4-[2'-(6-nitroindazolyl)]-N-[.delta.(2,4-di-tert-amylphenoxy)-but yl]-2-naphthamide;

1-hydroxy-4-[2'-(6-aminoindazolyl)]-N-[.delta.(2,4-di-tert-amylphenoxy)-but yl]-2-naphthamide;

1-hydroxy-4-[2'-(6-acetaminoindazolyl)]-N-[.delta.(2,4-di-tert-amylphenoxy) -butyl]-2-naphthamide;

1-hydroxy-4-[2'-(6-chloroindazolyl)]-4'-(4-tert-butylphenoxy)-2-naphthanili de;

1-hydroxy-4-[2'-(6-nitroindazolyl)]-N-(n-dodecyl)-2-naphthamide;

1-hydroxy-4-[2'-(5-chloroindazolyl)]-N-(2'-ethylhexyl)-naphthamide;

1-hydroxy-4-(2'-indazolyl)-4'-(4-tert-butylphenoxy)-2-naphthanilide and

1-hydroxy-4-(2'-indazolyl)-N-(n-octadecyl)-2-naphthamide.