US3512979A - Process for development of photographic silver halide color materials - Google Patents

Description

United States Patent Oflice 3,512,979 Patented May 19, 1970 3,512,979 PROCESS FOR DEVELOPMENT OF PHO- TOGRAPHIC SILVER HALIDE COLOR MATERIALS Tadashi Nagae, Haruhiko Iwano, and Isao Shimamura, Kanagawa, Japan, assignors to Fuji Photo Film (30., Ltd., Kanagawa, Japan No Drawing. Filed June 14, 1967, Ser. No. 645,900 Claims priority, application Japan, June 17, 1966, 41/39,231 Int. Cl. G03c 7/30 US. C]. 9655 6 Claims ABSTRACT OF THE DISCLOSURE In the case of developing a photographic silver halide light-sensitive color film in a developer containing pphenylenediamine or a derivative of it, the formation of fogs can be reduced without lowering the developed color density by incorporating in the developer a mercapto aliphatic acid or derivative thereof represented by the formula: HSRCOOM, wherein R is a divalent alkyl group having from 1 to carbon atoms, inclusive, in the chain, M isH, or an alkali metal, or a monovalent positive group such as NHJ. Preferably used in coupler developer solutions.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to an improved process for color development of photographic silver halide color materials and, more particularly, to a process for color development using a color developer containing a mercapto aliphatic acid or a derivative thereof.

Description of the prior art A multi-layer photographic material used for color photography has usually on a support at least three superimposed silver halide layers having different spectral sensitivities. For example, such photographic color material is usually composed of a lowermost red sensitive emulsion layer, a green sensitive emulsion layer, a yellow filter layer and an uppermost blue sensitive emulsion layer, in that order. By the yellow filter layer, a blue light passed through the uppermost blue sensitive emulsion layer is absorbed almost completely, so that it does not affect the green sensitive or the red sensitive emulsion layers. Further, in some cases, the material may have other emulsion layers or intermediate layers for other specific purposes, and may have also a surface protective layer. On the other hand, in the case of color positive film or paper, the yellow filter layer is omitted and the arrangement of the silver halide emulsion layers on the support may often be changed to suit the circumstances.

In the usual reversal photographic color process, a color image is obtained by subjecting the aforesaid photographic color material, after exposure, to (l) a first development, (2) washing, (3) reversal exposure (to red light), (4) cyan development, (5) wash, (6) reversal exposure (to blue light), (7) yellow development, (8) wash, (9) second black and white development, (10) wash, (l1) reversal exposure (to white light), (12) magenta development, (13) Wash, (14) bleaching, (15) Wash, (16) fixing and (17) final wash.

In the color developments in the above-mentioned processes, a color developer mainly consisting of p-phenylenediamine or a derivative thereof is usually used. In such a color developer, anti-foggants, such as, 6-nitro-benzimidazole, are usually incorporated to prevent the formation of fogs, but the addition of the anti-foggant is accompanied with the disadvantage of reduction in developed density, or that of increase in developing time necessary to obtain sufiicient density. The prolonged development causes a color contamination. Recently, various antifoggants have been reported which do not reduce the density so much, for example, formamidinothiomethyl compounds (U.S. Pats. 2,899,306, British Pat. 886,722) and tetrazaindenyl or pentazaindenyl compounds (Birtish Pat. 898,005 and US. Pat. 2,956,876).

'lherefore, an object of this invention is to provide a color development process capable of preventing effectively unexposed areas of a photographic silver halide color material from being fogged during development, preventing the reduction in developed color density, reducing remarkably the formation of color contamination, promoting the rate of bleaching, and increasing color purity.

SUMMARY OF THE INVENTION The inventors have found, as the results of various investigations, that the above objects of this invention can be achieved by incorporating in a color developer mainly consisting of p-phenylenediamine or a derivative thereof a mercapto aliphatic acid or a derivative thereof represented by the following general formula: HSRCOOM, wherein R represents a divalent alkyl group having from 1 to 5 carbon atoms, inclusive, in the chain, M is H, or an alkali metal, or a monovalent positive group such as NH4+- The examples of the compounds shown by the above general formula are illustrated below:

(1) Thioglycollic acid HS--CH COOH (2) a-Mercaptopropionic acid SH (3) fl-Mercaptopropionic acid HS(CH COOH (4) p-Mercaptobutyric acid CHaOHOHz-C 0 OH in (5) B-Mercaptoisovaleric acid O-CH2-C 0 OH 0113 SH (6) e-Mercaptocaproic acid HS-(CH COOH In the above formula, the number of carbon atoms in R is from 1 to 5 but is most preferably from 1 to 3 and the mercapto aliphatic acids having higher carbon atoms in R are comparatively inferior on the point of solubility in the color developer.

The above-mentioned compounds of this invention are effectively added to color developers for processing of photographic reversal color materials and these compounds are particularly effective for the development by coupler-developer type solutions, that is, the development composed of three different color developers into which couplers suitable for each of them are added and used successively.

The concentration of the mercapto aliphatic acids or the derivatives thereof used in the present invention depends on compound to be employed, type and concentration of color developing agents used, type of coupler and the pH of the color developer. Usually it falls in the range from 0.00 to 2.0 g. and most preferably 0.01 g. to 0.5 g. per one liter of the color developing solution. If

the concentration of the compound of this invention is too high, decrease in developed density occurs although the fog formation may be sufliciently prevented, while if the concentration is lower than that mentioned above, the anti-fogging effect will be insufficient.

A color developing solution may contain, besides a color developing agent and a color coupler, alkaline substances such as sodium hydroxide or sodium carbonate; fog retarders, such as potassium iodide, potassium bromide, or benzimidazole, an anti-oxidant, such as sodium sulfite and other inorganic salts, such as sodium sulfate. The mercapto aliphatic acids or derivatives thereof used in this invention can be effectively added to the color developer containing the aforesaid various additives.

In a photographic reversal color process in accordance with the present invention, any silver halide emulsion can be employed. This may be sensitized by a chemical sen sitizer and the like. Besides, other usual stabilizers, hardening agents, etc., may also be used in the emulsion.

The color developing agents used in the color developers of this invention are N,N-diethyl-p-phenylenediamine sulfite, N,N-diethyl-3-methyl-p-phenylenediamine hydrochloride, 4-amino-3-methyl-N-ethyl-N-methane-sulfonamide ethylam'line sulfate, 4-amino-3-methyl-N-ethyl-N-hydroxyethylaniline sulfate, N-et-hyl-N-hydroxyethyl-p-phenylenediamine sulfate and the like.

Further, the examples of cyan couplers used in cyan developer of this invention are 2,4-dichloro-l-naphthol, 2,-4-dichloro-S-teryl-sulfonamide-l -naphthol, 1 oxy 2- benzylnaphthamide, 2,6-dibromo-1,5-dihydroxynaphthalene and the like. Yellow couplers for yellow developers are benzoylacetoanilide, 1-w-benzoyl-4-(p-toluene-sulfonamido) acetoanilide and the like and magenta coupler for magenta developers are 1-phenyl-3-(m-nitrobenzoylamino)-5-pyrazo1one, cyanoacetyl cumarone and the like. Other couplers soluble in the developer may also be suitable for this invention.

The following examples will serve to illustrate more fully the manner of practicing the invention.

EXAMPLE 1 A multi-layer color film prepared by applying on a cellulose acetate support a gelatino iodobromide emulsion sensitive to red light, a gelatino iodobromide emulsion sensitive to green light, a yellow filter layer containing colloidal silver capable to absorb blue light, and a gelatino iodobromide emulsion sensitive to blue light, in this order successively, was exposed on a sensitometer and then subjected to the following processes:

Tempera- Time Process Step ture 0.) (min.)

First development 24 5 Wash 24 2 Reversal exposure (to red light) (from the back), GMS- 200 Cyan color development 24 5 Wash 24 2 Reversal exposure (to blue light) (from the front), OMS 200 Yellow color development 24 5 ash 24 2 Second Black and White Development- 222 g as Reversal exposure (to white light), OMS... 2, 000 Magenta color development 22: 5 8 24 2 24 2 Fixin 24 2 Final wash 24 2 The compositions of the processing solutions used in this process were as follows:

First and second black and white developers Sodium sulfite g. N-methyl-p-aminophenol sulfate-2.0 g. Hydroquinone8.0 g.

Sodium carbonate mono-hydrate-S 2.5 g. Potassium bromide5.0 g.

Potassium thiocyanatel.0 g.

Water to make-1 liter Cyan developers Yellow developer Sodium sulfite5.0 g.

N,N-diethyl-p-phenylenediamine sulfate-2.5 g. Potassium bromidel.0 g.

Potassium iodide (0.1% aqueous solution)5.0 ml. w-Benzoyl-4-(p-toluenesulfoamido) acetoanilide1.2 g. Sodium hydroxide2.5 g.

Magenta color developer Sodium sulfite-S .0 g.

2-amino-5-diethylaminotoluene hydrochloride2.0 g. Potassium bromide-0.8 g.

1-phenyl-3- (m-nitrobenzoylamino -5-pyrazolone1.4 g. Sodium hydroxide-2.0 g.

n-Butylamine5.0 ml.

Water to make-l liter.

Ferricyanide bleach Potassium ferricyanide-IOO g. Potassium bromide10 g. Borax-2 g. Boric acidl g. Water to make1 liter.

Fixer Sodium thiosulfite-- g. Sodium sulfite--10 g. Water to make-1 liter.

In this color reversal processing, the mercapto aliphatic acids of our invention were added to the cyan developer (the amount of mercapto aliphatic acids added were described by grams per one liter of the color developer throughout the examples of this invention).

Experiment No. Additives Amount, g./l.

1 Nona 2 B-Mercaptoproplouic acid 0. 05 3- do 0. 10

The photographic results obtained by the development are shown in the following table in which the degree of color contamination of the areas exposed to red light is expressed by the ratio (DR/DG), that is the ratio of red filter density to green filter density and the ratio (DR/DB), that is, the ratio of red filter density to blue filter density of the areas exposed to red light. The lower these ratios are, the better the purity of the red color on a photographic material reproduced from an object.

Purity of Red Color Reproduced Experiment No. DR/DG DR/DB 5 As shown in the above table, by incorporating the mercapto aliphatic acid of this invention into the color developer the quality of color reproduction was improved effectively.

EXAMPLE 2 In the process as described in Example. 1, after the cyan development, the film was washed with water for 8 minutes and bleached and fixed as in Example 1 to provide a cyan image.

The results are shown in the following table. In the table, the degree of cyan color contamination is expressed by cyan density values of thereas exposed to red light. The cyan density at the area is caused by the formation of undesirable fogs in the green or blue sensitive emulsion layers which should be principally developed to magenta or yellow.

A single layer film containing-no sensitizing dye was exposed to a white light instead of red reversal exposure and then developed in the cyan developer as in Example 1. Thereafter, omitting the blue reversal exposure, yellow color development and the second black and white development, the film was subjected to the magenta color development and then, after a wash of 8 minutes, was bleached and fixed. The results are shown in the following table in which the color density ratio DG/DR, that is, the ratio of the magenta density to the cyan density, shows the extent of another type of color contamination, that is, contamination in cyan. A large value of the ratio means that the extent of magenta contamination in cyan during magenta color development is great. The addition of the compound of this invention lowers the contamination value as shown in the following table.

Color Con- Experiment Additive to Cyan Color Amount tamination N 0. Developer (grams) D G/D R None 0. 49 fi-Mercaptopropionle aoid 05 0. 31

Sodium B-mercaptopropionate.-. 0. 12 0. 30

EXAMPLE 4 The photographic material of Example 1 was developed by the same procedure as in Example 1 except that the compounds of the invention are added to yellow developer The photographic results thus obtained by the developments are shown in the following table. In the table, the purity of the blue color reproduced is shown by the ratio DB/DG, that is, the ratio of the blue filter density to green filter density and by the ratio DB/DR, that is, the ratio of blue filter density to red filter density of the areas exposed to a blue light. This corresponds to the extent of purity of the reproduced color of a blue object. The lower the ratio, the better the quality. The Stain D6 or DB in the table shows density values of the highest-light portion of the test film measured through green or blue filters and the lower the value, the better the image quality. Besides these values, the maximum blue density (D and the maximum green density (D are also shown in the table. Of course, the larger the value, the better the quality.

Purity of Blue Color lljllgp'eri- Reproduced Stain Maximum Density N0. DB/DG DB/DR DG DB DGmex. DBmeh' EXAMPLE} 5 A single layer spectrally unsensitized photographic material was processed as in Example 1, but this time, the compounds of this invention are added to the yellow developer and the red reversal exposure, and the cyan color development were omitted.

The results as shown in the following table, in which the ratio DG/ DB, that is, the ratio of the magenta density to the yellow density shows the extent of color contamination. Inadequate yellow development causes magenta 'color formation in the film, that is, magenta color contamination in yellow. By the addition of the compound of this invention, the value of color contamination was decreased effectively.

Color Contamination, D G/DB Amount (grams) Experiment No.

The photographic materials of Example 1 were developed by the same procedure as in Example 1, except that the cyan developer applied at 24 C., for 7 minutes, has the following composition:

Cyan developer Purity of Red Color Reproduced Experiment I Amount N0. Additive (grams) D RID G D R/DB 1 None 0. 34 0. 36 2. Thioglyeollic acid 0. 1 0.30 0. 31 3. B-Mercaptopropionie acid 0. 1 0. 28 0. 29 4- a-Mercaptopropionie acid- 0. 1 0. 29 0. 5. a-Mercaptocapronie acid- 0. 1 0. 31 0. 33

EXAMPLE 7 The same procedure as in Example 4 was repeated but using a yellow color developer, applied at 24 C., for 7 mints, having the following composition:

Yellow developer Sodium sulfite5.0 g.

Sodium sulfate50 g.

Potassium bromide-O.5 g.

Potassium iodide (0.1% aqueous solution)10 ml. Benztriazole (1% methanol solution)-1.0 ml. N,N-Diethyl-p-phenylenediamine sulfite3.0 g. w-Benzoyl-o-chloroacetonanilide-1.8 g.

Sodium hydroxide-2.8 g.

Water to make 1 liter.

The results obtained by adding the mercapto aliphatic acid of this invention into the yellow color developer are shown in the following table.

2. The process as claimed in claim 1 wherein said mercapto aliphatic acid is selected from the group consisting of thioglycollic acid, a mercaptopropionic acid, 3 mercaptopropionic acid, ,8 mercaptobutyl ic acid, ,8 mercaptoiso-valeric acid, and u-mercaptocapronic acid.

3. The process as claimed in claim 1 wherein said .rnercapto aliphatic acid and a derivative thereof are incorporated in the color developing solutions in an amount of from about 0.001 g. to 2.0 g.

4. The process as claimed in claim 1 wherein said compound is incorporated in a cyan color developing solution.

5. The process as claimed in claim 1 wherein said compound is incorporated in a magenta color developing solution.

Purity of Blue Color Reproduced Stain Experiment Amount No. Additive (grams) DB [D G DB/D R D G DB ne 0. 40 0. 45 0. l4 0. l4

2 Thioglycollic acid 0. 1 0. 35 O. 43 0. 12 0. 11

3-- fl-Mercaptopropionic acid 0. 1 0. 30 0. 40 0. 10 0. 10

4.- a-Mercaptopropionie acid- 0. 1 0. 32 0. 41 0. 10 0. 10

5 e-Mercaptocapronic acid- 0. 1 0. 34 0. 42 0. 11 0. 11

What we claim is: 25 6. The process as claimed in claim 1 wherein said com- 1. A process for color development of a photographic silver halide color material comprising contacting said material with a. color-developing solution containing a color developing agent selected from the group consisting of pphenylenediamine and derivatives thereof, a coupler soluble in the developing solution, and a mercapto aliphatic acid compound represented by the following general formula: HSRCOOM, wherein R represents a divalent alkyl radical having from one to five carbon atoms and M represents a member selected from the group consisting of hydrogen, alkali metal and an NH radical.

pound is incorporated in a yellow color developing solution.

References Cited UNITED STATES PATENTS 3,201,243 8/1965 Larson 96-109 3,255,008 6/1966 Telft. 3,326,684 6/1967 Nishio 96--61 J. TRAVIS BROWN, Primary Examiner U.S. Cl. X.R.