US3552960A - Silver dye bleach process using bleachable nitro-aryl dyes - Google Patents

Abstract

THE COMPOUNDS ARE OF THE CLASS OF NOBEL NITRO DYES, USEFUL IN A SLVER DYE BLEACHING METHOD OF COLOR PHOTOGRAPHY, HAVING AS THE CHROMOPHORE A NITRO GROUP, AND AS THE AUXOCHROME -OX (WHEREIN X REPRESENTS A HYDROGEN ATOM, AN ALKALI META OR 1/2 CALCIUM AND AMMONIUM) OR -NHY (WHEREIN Y REPRESENTS A HYDROGEN ATOM, A LOWER ALKYL GROUP, A SUBSTITUTED ALKYL GROUP, A CYCLIC ALKYL GROUP, AN ARYL GROUP AND A SUBSTITUTED ARYL GROUP), AND THE -NHY MAY FORM A RING TOGETHER WIT -O- OR -N-R (WHEREIN R IS AN ARYL GROUP OR A SUBSTITUTED ARYL GROUP).

Description

United States Patent ()flice 3,552,960 Patented Jan. 5, 1971 3,552,960 SILVER DYE BLEACH PROCESS USING BLEACHABLE NITRO-ARYL DYES Hideo Kondo and Shigeru Wata iabe, Kanagawa, Japan, ilssignors to Fuji Photo 'Film Co., Ltd., Kanagawa,

apan I No Drawing. Filed July 19, 1967, Ser. No. 654,349 Claims priority, application Japan, July 19, 1966,

41/47,188 Int. Cl. G03c 1/10, 5/52 US. CI. 96-20 29 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION (1 Field of the invention The present invention relates generally to a photoggraphic color process and particularly to a process for represents a hydrogen atom, an alkali metal, /2 calcium or ammonium) or NHY, (wherein Y represents a hydrogen atom; a lower alkyl group;'a substituted'alkyl group, such as an aminomethyl group or a hydroxyethyl group, a cyclic alkyl group; an aryl group; or a spbstituted aryl group such as a hydroxyphenyi group or {sulfanaphthyl group) which may form fa ring together with APR (wherein R represents an aryl group or a substituted aryl group such as a m'ethoxyphenyl group) which is at the ortho position to NHY.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Among thesenitro dyes a preferable dye is a nitrobenzene or a nitronaphthalene having OX or NHY (X and Y are as defined above) at the ortho-position to the nitro group. In addition, the benzene ring or the naphthalene ring may be substituted with at least one of the following: a n'itro group, a lower alkyl group, an

obtaining color photographs by a silver dye bleaching method. 7

(2) Description of the prior art The production of photographic colorimages by a silver dye bleaching method is based on the fact that certain types of dyes are destroyed by a suitable treatment in the presence of metallic silver. In a silver dye bleaching method, after exposure and development, a photographic .gelatine-silver halide emulsion layer which is uniformly colored with a proper dye is processed in a bleaching bath capable of simultaneously oxidizing the silver image formed and reducing (bleaching) the dye at the areas having the silver images. The silver salts and remaining metallic silver are then removed to provide a reversal dye image of the initial silver image. By this process, a monochromatic ir nage or a multi-color image canvbe obtained. For these purposes, there have hitherto been used azo dyes, anthraquinone dyes, indigoid dyes, and phthalocyanine dyes. 7

aryl group, a substituted aryl group such as a nitro phenyl group, an amino group, a cyano group, a halogen atom, a carboxyl group, a sulfonic acid group, SO R (vihere R represents an aryl group or a substituted aryl group such as a nitro-phenyl group), and

R2 SO2N/ R3 I (R and R each represent a hydrogen atom, a lower alkyl group, a substituted alkyl group such as an aminomethyl group or a hydroxyethyl group, a cyclic alkyl group, an aryl .group or a substituted aryl group such as a hydroxyphe'nyl group). The typical examples of the The dye used in the silver dye bleaching method must a be one which can be easily bleached by a bleaching bath in proportion to the amount'of photographic silver image and can also be completely bleached at the areas of maxi- :mum silver image density. In addition, the dye must have I good fastness to light. It is desirable that the individual light. Therefore, it is desirable to provide a process of ,obtaining photographic color images by a silver dye 'bleaching method using a dye satisfying the aforesaid conditions.

SUMMARY OF THE INVENTION The present invention is based on the discovery of the fact that nitro dyes can be bleached by a photographic "silver image in a step of asilver dye bleaching method.

By nitro dye is meant a dye having as the chromophore a nitro group and as the auxochrome OX (wherein X nitro dyes used in this invention areas follows:

oooH

(1) Br NO:

00101; In dextram oline 1 6300 (IJNHR 02N i-NOz SOaNH;

Color Index Compound No. 10302 O2N NH:

-- NC CN Color Index Compound No. 10306 Color Index Compound No. 10310 N02 7 NOa H .1. 7 .1

NO; NO; (5) 5 Color Index-Comp Color Index Compound No.10311 N 02 N01 7 Color Index Compound No. 10345 10 v i I N(|)2 N02 (6) 3 I Color Index Compound No. 10315 15 00101 Index Compound 10350 ONaaS- N02 I j (16) Color Index Compound No. 10385 I N02 7 N0: OzN-QNH-QSOaNa' Color Index Compound No. 10310 I v 7 Color Index Compound No. 10370 ongomsoaiwa Color Index Compound No. 10325 N 0:

Color Index Compound No. 10380 I m 1."? W 0 J r' j v 1 NO, '31 1 C1 0 I Color Index Compound No. 10395 Color Index Compound No. 10330 i 0, v

N02 HgNO2S I v v, I I V I K (20) NH 4 Color Index Disperse Yellow 33 r (10) v .NOI

Color Index Compound No. 10335 I i l I I I v v o I H E (11) Color Index Compound No. 10338 00101- Index Compound No. 10305 I 0, N01 f 501M N02 f I v,

OzN-QNH-Q H color Index Compound No. 10340 p01 Indox Compound No. 10400 H v HsCz N071 v slbaNa I I v I Nozs-NHNHNncoom I-I5C2/ (2 Color Indx Compound No. 10405- SOaNa S OaNa 0010i Indx Compound No. 10410 v SOaNa Color Index Compound'No. 10415 N02 1 Naols O/ -NO2 l COOH Color Index Compound No. 10425 N02 NH l NaOsS- N I g Color Index Compound No. 10430 NH; NH H03S '-NOg Color Index Compound No. 10435 N02 NH NQO5S- NO2 r NHz H-C CO Color Index Compound No. 10440 Kagabu Kyokai (The Organic Synthetic Chemical Society) and published in 1959. As disclosed therein, the method of preparing this dye is by the condensation of aniline with 3-nitro-4-chlorbenzene sulfonamide.

The dyes shown by the above structures (3), (18), (19) and (212)-(28) have a brownish color hue and hence can be used as the dyes for mono-chromatic lightsensitive elements, for example, the copying light-sensitive elements described in the specifications of British Pats. 999,996 and 1,002,345. By exposing a silver halide emulsion layer colored by such a dye through a black and white original, developingand fixing as in a conventional silver dye bleaching method, processing the layer in a dye bleaching bath to form a color image, and removing remaining silver, a positive copy can be obtained.

As is well known, nitro dyes have been employed for dyeing natural fibers such as wool and cotton or artificial fibers such as acetates, polyamides, and polyesters. Many nitro dyes as well as the preparation processes thereof are known. 1

In the present invention, the nitro dye is used for dyeing a colloid, such as gelatin or poly-vinyl alcohol, for forming a photographic layer. In particular, the nitro dye is used as a dye for forming the yellow image of a multiple layer light-sensitive color element such as a light-sensitive negative color element or a light-sensitive positive color element the image of which may be observed by transmitted light or reflected light. A colloid for forming a light-sensitive layer is colored by the nitro dye and then mixed with a silver halide emulsion. The resulting mixture may be applied to a support as a photographic layer. Alternately, the dye may be brought into contact with an emulsion layer to be incorporated into the layer which consists of only the above-mentioned colloid, such as a layer consisting only of gelatin. Furthermore, after exposure or development, the emulsion layer may be colored with the nitro dye. These nitro dyes may be used in the same manner as conventionally employed dyes.

In the case of a water-soluble nitro dye, the dye can be mixed in a gelatin solution or a photographic emulsion as an aquous solution thereof. In the case of a waterinsoluble dye, the dye is dispersed in a gelatin solution or a photographic emulsion by using a dispersing agent such as sodium alkylbenzene sulfonic acid. Moreover, a nitro dye soluble in an organic solvent may be dissolved in an organic solvent and the solution thus obtained may be mixed in a gelatin solution or a photographic emulsion, or the organic solvent solution may be emulsion-dispersed in getain by using a surface active agent. In addition, after exposing and developing, an uncolored photographic emulsion layer may be dyed with an aqueous solution of a water-soluble nitro dye. The colored layer obtained is then used, for example, as a component of a two or three-color system.

Suitable organic solvents are alcohols such as methanol, ethanol, ethylene glycol, a monoalkyl ether of ethylene glycol, and a monoalkyl ether of diethylene-glycol, esters such as ethyl acetate and butyl acetate; ethers such as ethyl ether, dioxane, and tetrahydrofuran, ketones such as acetone and methylethylketone; amides such as lactams and dialkylcarbamides; and the like. Moreover, high boiling point oily solvents may be employed. For example, alkyl esters of phthalic acid such as dibutyl phthalate, dioctyl phthalate, etc., phosphoric acid esters such as triphenyl phosphate and tricresyl phosphate; alkylamides such as dibutyllaurylamidel and acetanilides such as N- butylacetanilide.

As the dye bleaching bath, known acid bleaching baths may be used. The bleaching bath contains a solvent for silver such as thiourea, se-micarbazide, etc., and an alkali metal halide such as sodium chloride, potassium bromide, etc. The bleaching bath may contain as a catalyst an accelerator used in the bleaching processing of an azo dye in a conventional silver dye bleaching method, such as anthraquinone sulfonic acid, dimethylquinoxaline, aminohydroxyphenazine, and the like.

According to the present invention, an image having utterly colorless highlight portions can be obtained since the nitro dye can be easily bleached and hence the bleaching can be completely conducted.

The invention will be explained in more detail by referring to the following examples.

EXAMPLE 1 Into 2 ml. of tricresyl phosphate was dissolved 0.2 g. of Cl. Disperse Yellow 42 represented by aforesaid structure (21). The solution obtained was added into 10 ml.

of a 10% aqueous gelatin solution containing 2 ml. of a 10% aqueous solution of sodium alkyl-benzene sulfonate and subjected to dispersing by means of a homoblender. After mixing 6 g. of the dispersion with 20 g. of a silver bromide photographic emulsion (containing about 30 g. of silver bromide per one kg. of emulsion), the resulting mixture was applied on a glass plate.

The light-sensitive plate was exposed through a step wedge and then developed for 10 minutes in a developer having the following composition.

G. N-methyl-p-aminophenol 1/2. sulfate 2 Sodium sulfite (anhydrous) 30 Hydroquinone 8 Sodium carbonate (mono-hydrate) 20 Potassium bromide 4 Water to make 1 liter.

The plate was then washed with water and fixed for 4 minutes in a fixing solution having the following composition:

. G. Sodium thiosulfate (anhydrous) 350 Sodium sulfite (anhydrous) 10 Water to make 1 liter.

The plate was washed with Water, hardened with a 10% aqueous solution of formaldehyde, and then washed with water again. The plate was then processed for 15 minutes in a dye bleaching solution having the following composition:

Thiourea-6O g.

Potassium bromide-30 g. Concentrated hydrochloric acid-.430 ml. 2-amino-3-hydroxyphenazine0.01 g. Water to make 1 liter.

The plate thus bleached was then washed With water and subjected to silver bleaching in a solution having the following composition:

Crystalline copper sulfate100 g. Concentrated hydrochloric acid-100 ml. Water to make 1 liter.

The plate was then washed with water, fixed in a fixing bath having the same composition as shown above, washed again with water, and dried. A yellow dye image having excellent light fastness and a lemon-yellow hue Was obtained. Bleaching of highlights was complete, and the blue optical density was 0.12. This is particularly suitable as an image of a yellow component in a multiple color type light-sensitive element. For comparison, the same procedure as above was repeated using the conventional yellow azo dye having the following structure to provide an image. The blue optical density of the highlight portion was only 0.35.

e t-Q EXAMPLE 2 The same procedure as in Example 1 was repeated using 4 ml. of ethyl acetate instead of 2 ml. to tricresyl phosphate and almost identical results were obtained.

EXAMPLE 3 By repeating the same procedure as in Example 1 While using 2 ml. of dibutyl phthalate and 1 ml. of butyl acetate instead of 2 ml. of tricresyl phosphate, almost identical results were obtained.

EXAMPLE 4 EXAMPLE 5 By repeating the same procedureas in Example 1 while using the dye shown by structure (9) instead of Cl.

Disperse Yellow 42 in Example 1., a yellow image was obtained.

EXAMPLE 6 By repeating the same procedure as in Example 1 while using the dye shown by structure (11), a yellow image was obtained.

EXAMPLE 7 Into 40 m1. of water, 0.4 g. of Cl. Disperse Yellow 33 shown by structure (20) was dispersed. The dispersion was mixed with 50 g. of a silver bromide emulsion (containing about 30 g. of silver bromide per one kg. of emulsion), and the mixture was applied to a glass plate. The light-sensitive plate was exposed and processed as in Example 1 to provide a yellow wedge image.

EXAMPLE 8 Into 100 ml. of water, one g. of Cl. Acid Yellow shown by structure (7) was dissolved. After mixing ml. of the solution of the dye with g. of a silver bromide emulsion (containing about 30 g. of silver bromide per one kg. of emulsion), the mixture was applied to a glass plate. The dye was fixed in the emulsion'layer by a precipitant such as diphenylguanidine (described in the specification of U.S. Pat. 2,172,308). The light-sensitive plate was exposed through a step Wedge, developed in a developer containing N-methyl-paminophenol /2 sulfate and hydroquinone, and then fixed. The plate was then hardened by a diluted solution of formaldehyde and thereafter processed in a dye bleaching bath containing 30 ml. of concentrated hydrochloric acid, 30 g. of potassium bromide and 60 g. of thiourea per one liter of bleaching bath. After bleaching remaining silver in a copper sulfate bath strongly acidified by hydrochloric acid, the plate was fixed in a conventional manner. A yellow dye image was obtained.

EXAMPLE 9 Into 300 ml. of a 10% aqueous gelatin solution, 2 g. of Cl. Acid Yellow 24 shown by structure (6) was dissolved. The colored gelatin solution was applied to a dry-thickness of 3 microns to a silver halide emulsion layer of 7 microns dry-thickness coated on a glass plate. When the light-sensitive plate was processed as in Example 1, a yellow image was obtained in the colored gelatin layer in proportion to the silver image formed in the silver halide emulsion layer.

' EXAMPLE 10 A standard photographic light-sensitive black and White film was exposed, developed, and fixed in the conventional manner. The film was dyed for about 20 minutes at room temperature in a 2% aqueous solution of Cl. Acid Yellow 24 shown by structure (6). In this case, a dyeing aid may be added as in standard dyeing techniques. After dyeing, the film was subjected to the dye bleaching and subsequent processings as in Example 1 to provide a yellow image.

What is claimed is:

1. In a silver dye bleaching method which comprises exposing to light a photographic light sensitive element comprising a silver halide containing'emulsion layer uniformly colored with at least one bleacha'ble nitro aryl dye, processing and subsequently bleaching said element, the improvement wherein said dye is a bleachable nitro aryl dye having as the chromophore a nitro group and as the auxochrome a member selected from the group consisting of OX, wherein X represents a member selected from the group consisting of a hydrogen atom, an alkali metal, /2 calcium and ammonium, and NHY, wherein Y represents a member selected from the group consisting of a hydrogen atom, a lower alkyl group, a substituted alkyl group, a. cyclic alkyl group, an aryl Z9 group and a substituted .aryl. group,; said --NHY having the capability of forming a .ring together with a member selected from the group consisting of O and iwherein R is selected from the group consisting of an aryl group and a substituted .arylgrofip, which is at the ortho position to NHY.

'2. A process as in "claim 1 wherein Y represents a substituted alkyl group selected from the group consisting of an afninomethyl group and a hydroxyethyl group.

3. A process as in claim 1 wherein Y representsa substituted aryl group selected from the group consisting of a hydroxyphenyl group and a sulfonaphthyl group.

4. A process as in claim 1 wherein R represents a methoxyphenyl group.

5. A process as in claim 1 wherein the dye is nitrobenzene havin OX or NHY at the orthoposition to the nitro group. 1

6. A process as in claim wherein the dye is substituted with at least one member selected from the group consisting of a nitro group, a lower alkyl group, an aryl group, a Substituted aryl group such as a; nitrophenyl group, an amino group, a eyano group, a halogen atom, a carboxyl group, a sulfonic acid group, SO R (wherein R represents a member selected from the group consisting of an aryl group and a substitutd aryl group such as a nitrophenyl group),

(wherein R and R may be selected from the group consisting of a hydrogen atom, a lower alkyl group, a substituted alkyl group selected from the group consisting of an amino methyl group and a hydroxy ethyl group, a cyclic alkyl group, an aryl group and a substituted aryl group such as a hydroxyphenyl group).

7. A process as in claim '5 wherein the dye is nitro naphthalene.

8. A process as in claim 6 wherein the dye is nitro naphthalene.

9. A process of obtaining color photographs by a silver dye bleaching method as described in claim 1, using 2. nitro dye having the formula:

10. A process of obtaining color photographs by a silver dye bleaching method as described in claim 1 using a nitro dye having the formula:

11. A process of obtaining color photographs by a silver dye bleaching method as described in claim 1 using a nitro dye having the formula:

12. A process of obtaining color photographs by a silver dye bleaching method as described in claim 1 using a nitro dye having the formula:

I QM H 13. A process of obtaining color photographs by a silver dye bleaching method as described in claim 1 using a nitro dye having the formula:

14. A process of obtaining color photographs by a silver dye bleaching method as described in claim 1 using a nitro dye having the formula:

16. The process as claimed in claim 1 wherein said nitro dye is incorporated in a photographic silverhalide light-sensitive emulsion layer in said photographic lightsensitive element.

17. A process as in claim 16 wherein the nitro dye is used as a dye for dyeing a colloid in the photographic light-sensitive element so as to form the yellow image of a multiple layer light-sensitive element, said colloid being selected from the group consisting of gelatin and polyvinyl alcohol.

18. A process as in claim 16 wherein a colloid for forming a light-sensitive layer in said photographic element is colored by the nitro dye and then mixed with a silver halide emulsion for subsequent application to a support.

19. A process as in claim 16 wherein a water soluble nitro dye is mixed in the sensitive emulsion layer as an aqueous solution thereof.

20. A process as in claim 16 wherein a water insoluble nitro dye is dispersed into the sensitive emulsion layer by using a dispersing agent.

21. A process as in claim 16 wherein a nitro dye soluble in an organic solvent is formed into a solution, and the solution thus obtained is mixed with the sensitive photographic emulsion.

22. The process as claimed in claim 1 wherein said nitro dye is incorporated in a gelatin layer adjacent to 211 photographic silver-halide light-sensitive emulsion ayer.

23. A process as in claim 22 wherein a water soluble nitro dye is mixed into the gelatin emulsion by dissolving it in an aqueous gelatin solution.

24. A process as in claim 22 wherein a water soluble nitro dye is dispersed into the gelatin emulsion by using a dispersing agent.

25. A process as in claim 22 wherein a nitro dye soluble in an organic solvent is formed into a solution therewith and mixed with a gelatin solution.

26. A process as in claim 22 wherein the organic solvent solution is emulsion dispersed in gelatin by using a surface active agent.

27. The process as claimed in claim 1 wherein, after exposing and processing, said bleaching of said nitro dye is accomplished by subjecting said element to a dye bleaching bath.

28. A process as in claim 27 wherein the dye bleaching bath contains a solvent for silver and an alkali metal halide.

29. A process as in claim 27 wherein the dye bleaching bath contains, as a catalyst, a dye bleaching accelerator.

m sis- 99 I 5 NORMAN TORCHZIN, l ri mary. Examiner