US2527476A - Cyanoacetylhydrazones as photographic color couplers - Google Patents

Description

Patented Oct. 24, 1950 CYANOACETYLHYDRAZONES AS PHOTO- GRAPHIC COLOR COUPLERS Pierre Joseph Marie Bruylants, Winksele-Veltem,

near Louvain, and Philibert Leopold Jozef Raymond Merckx, Mortsel, near Antwerp, Belgium, assignors to Gevaert Photo-Producten N; V., Mortsel-Antwcrp, Belgium, a company of Belgium No Drawing. Application March 14, 1947, Serial No. 734,854. In Germany March 17, 1941 I Section 1, Public Law 690, August 8, 1946 Patent expires March 17, 1961 11 Claims. (Cl.95--6) P with the NH2 group of the hydrazides, such as aldehydes, ketones, dialdehydes; diketones, :keto- This invention relates to photographic color developers and to processes for color development applicable in color photography. aldehydes, and halogen compounds containing the It is known that colored photographs may be group --CX2 wherein, X represents an-halogen obtained by using a developer which during the 5 atom such as CH3-CO--CHC1zand development forms colored insoluble oxidation products. These products color the gelatine around the silver grains of the silver image.

It is also known to obtain colored images by using in the developing baths certain substances called color couplers which combine with the oxidation products of the developer with the formation of dyestuifs which precipitate simultaneously with the developed silver grains.

Many color couplers have hitherto been used or proposed, such as substituted or unsubstituted phenols and naphthols, nitrophenylacetonitriles and acetamide derivatives, characterized by the presence of an acid-reactive methylene group, isoxazolones, coumarones and pyrazolones.

Up to now, no theory has been advanced for p the mechanism of photographic color development. Consequently, it is impossible to specify I in advance with dependable certitude whether a CHBn Color couplers obtained by condensationof cyanoacetylhydrazides with products containing one or more reactive methylene groupshave been described in U. S. Patent,2,375,344 and are not included in the .present invention.

As typical examples of color couplers of the new group, the following may be mentioned:

given product is a usable color coupler or not.

Furthermore, although numerous color couplers Cmmacetymydmmne are known, it is not always possible to choose (2) among them the product which will give by condensation with the oxidation product of the developer the desired color corresponding to the tint 0f the dyestuffs already formed or subsequently to be formed in other layers. A further limitation in connection with the color couplers 3 r OCHPCH=NJNHCO=CH2 CN Cyanoacetylhydrazone of piperonal already known resides in the fact that only such color couplers can be used which form dyestuffs which are both non-diffusing in water and stable to photographic baths. 4)

The present invention relates to a new group of color couplers which meet the aforesaid con- Cyanoacetylhydrazone -of phenylacetaldehyde CHr-GH=CH-Cl3I=N-NHCO-GHr-GN Cyanoacetylhydrazone of crotonaldehyde ditions. I v I Cyanoacetylhydrazide can scarcely be consid- CH (IJCH=CHYCH=NNH OOCHQCN ered as a usable color coupler. If added to a v developer which .contains among thers d.iethy1 Cyauoacetymydrazone of beta-furylacrolein para-phenylenediamine, it only gives a slightly r 1, colored image. e) .CH=N-NH-COCHn-CN Unexpectedly, we now have found that very favorable results as to color intensity and color brightness are obtained by adding to the developers as color couplers monoor polyoyanoacetylhydraz'ones derived from substances without a reactive methylene group.

These monoand polycyanoacetylhydrazones are obtained by condensation of one or more cyanoacetylhydrazide molecules with products C a n one 01 more groups which may react Cyanoacetylhydrazone 701f pyruvic-aldehyde Bis-cyanoacetylhydrazone of terephthalic-aldehyde cH3'co-o11=N-NH-co-om-cN ocmwhm co-om-on Cyanoacetylhydrazone of acetophenone NNH-C O-CHz-CN Cyanoacetylhydrazone otbenzal-acetone Br- C=N-NH-COCHz-CN O O NH Cyanoacetylhydrazone of mono-bromoisatinx (11) CH3CCHCOOC2H5 NHCO-CHz-CN Cyanoacetylhydrazone of alpha-phenylacetoacetic ethylester g I These formulaecorrespondat'the date of the present invention '"to' the'commonly accepted structures of' these products, but are nct:.intended to be rigorously binding."

These compounds are fully defined with regard to the practical application of the invention by the following description-'of their preparation. A hot aqueous solution .of cyanoacetylhydrazide is mixed with a hot alcoholic solution of the compound with which the hydrazide is to be condensed. Generally, condensation takes place immediately and the condensation product precipitates .inthe form of.crystals; ifnot, the solution-.is warmed'forsome time in a water bath. The condensation. of. a hydrazide, and especially of cyanoacetylhydrazide} with various compounds containing a ketone or. an. aldehyde group is.fully described in Berichte 27 (1894) 688, 40 (1907) 712 and 41 (1908)f 643.

By development in a diethyl-para-phenylenediamine developer containing a color coupler according to this invention, dyestuffs are obtained with an absorption maximumat about 4,800 to 5,500 A.

The new color couplers maybe added to a developing bath containing a normal quantity of sulphite and on account of this are very stable. They may easily be produced. and isolated, and are, moreover, very stable.

With aryl amine developers the new color couplers form dyestuffs practically insoluble in water and photographic baths and arecharacterized by an extreme brightness. or brilliance. The absorption curves of these dye-stuffs are generally of marked steepness which in color photography is. of great importance. Used with substituted aryl diamine developers, the color yield is generally very high.

The present invention also comprises:

(a) A new or an improved process for obtaining mu1ti-color photographs by the use of color couplers as above described.

(1)) The process for manufacturing multicolor photographs by adding the above-mentioned color couplers to the emulsion before or after it is coated and treating the latent photographic image with an aryl amine developer.

(0) New or improved color developers containing besides an aryl amine developer at least one of the above-specified color couplers.

(d) A new and improved process for color development by developing latent photographic image with an aryl amine developer containing at least one of the aforesaid color components followed by the removal of the silver image 4 formed by development so that only a bright and transparent color image remains.

(e) A photographic material which contains at least in one layer a bright and transparent color image consisting of the condensation product formed during the development from a color coupler as herein described and the oxidation product of an aryl amine developer.

The aryl amine derivatives which may be used as developers are mono-, diand tri-amino aryl compounds. As mono-amino developers may be mentioned aminophenols, aminocresols, aminonaphthols and their halogen derivatives. The most suitable and at the same time the best developers for use in the present invention are the aryl orthoand para-diamines such as orthoand para-phenylene diamines. These developers may be substituted in one amino group and/or in the nucleus. In this way, several developers may be obtained, as, for instance:

N-diethyl-paraphenylenediamine N-mono-ethyl-para phenylenediamine N dimethyl-para-phenylenediamine 3 -amino-6-diethyl-aminotoluene These developers are usually used in the form of their salts such as hydrochlorides or sulphates.

By the expression color development as used in.this specification is broadly to be understood the formation of a color image by the action of the color couplers. as described above on any oxidizing compounds formed either during development by the action of the silver halide of the latent image on the aryl developers or by the interventionof the silver of the developed image. I

In this last case, the silver image is treated with an oxidizing. bath before color develop? ment.

In order to obtain color images according to the present invention,.the following developing compositions may be used:

Formula 1 N-diethyl-para-phenylenediaminehydrochloride grams 4 Sodium sulphite cryst do 5 Sodium carbonate cryst do Sodium hydroxide do 0.5 Water to cubic centimeters 1000 Cyanoacetylhydrazone of piperonal rams 2 Formula 2 N-diethyl-para-phenylenediamine- Cyanoacetylhydrazone of monobromoisatin grams 2 name Acetone c ubic centimeters' 30 j 1 For use, B is added to A.

The color couplers may be dissolved in organic solvents, for instance acetone, though it is .'also ,possible to add them directly to the developing baths without using organic solvents.

The invention is not limited to the use of the color couplers in the photographic developing baths. One of the essential ingredients (the color coupler) which forms the dyestuif. during the development may also be added to the photographic emulsion, for instance, by adsorption ,on the silver salts before or after the emulsion is coated. The other ingredient of the colorforming baths, especially the aryl amine developer, may afterwards be applied as a bath during the development.

The invention may be applied for the manufacture of photographic multi-color pictures on plates, paper or film provided with gelatine or any other protective colloid for silver salts. The color developing process may be carried out for developing photographic material with one or more light-sensitive layers coated on one or on both sides of the support. The silver image formed during development may easily be bleached out, whereby the bleaching bath may not exert any undesirable influence on the color image. An aqueous solution of potassium ferricyanide and sodium thiosulphate easily removes the silver without damaging the color image.

We claim:

1. A color-forming developer comprising a primary aromatic amino silver halide developing agent and as color coupler a cyanoacetylhydrazone of the general formula wherein X represents the radical of a compound, which does not contain group capable of coupling with the oxidation product of a primary aromatic amino silver halide developing agent to form a dye image but which is capable of froming a hydrazone by reaction with a hydrazine and selected from the group consisting of aldehydes, ketones, and compounds having two halogen atoms directly linked to the same carbon atom, and n is a positive integer selected from the group consisting of l and 2, the cyanoacetyl group comprising the methylene group which acts as coupling function on color development.

2. A color-forming developer comprising a primary aromatic amino silver halide developing agent and as color coupler a cyanoacetylhydrazone of the general formula wherein X represents the radical of a compound which does not contain a group capable of coupling with the oxidation product of a primary aromatic amino silver halide developing agent to form a dye image but which is capable of forming a hydrazone by reacting with a hydrazine and selected from the group consisting of aldehydes, ketones, and compounds having two halogen atoms directly linked to the same carbon atom, the cyano acetyl group comprising the methylene group Which acts as coupling function on color development. c I T 3. A color-forming developer comprising a, primary-aromatic amino silver halide developing agent and as' color coupler the cyanoacetylhydrazone of piperonal. v

4. A color-forming developer comprising a primary aromatic amino silver halide developing agent'and as color coupler the cyanoacetylhydrazone of 5-nitro-7-methylisatin.

5. A color-forming developer comprising a primary aromaticamino silver halide developingagent and as color couplerthe cyanoacetylhydrazone of cinnamic aldehyde. j I 6. A color-forming developer comprising a primary aromatic amino silver halide developing agent and as color coupler a di-cyanoacetylhydr'azone of the general formula wherein X represent the radical of a comopund which does not contain a group capable of coupling with the oxidation product of a primary aromatic amino silver halide developing agent to form a dye image but which is capable of forming a hydrazone by reacting with a hydrazine and selected from the group consisting of "aldehydes, ketones, diand tetra-halogen compounds, the cyano acetyl group comprising the methylene group which acts as coupling function on color development.

'7. A photographic emulsion containing silver halide and a color coupler consisting of a cyanoacetylhydrazone of the general formula (CNCH2CONH-N=) "X wherein X represents the radical of a compound, which does not contain a group capable of coupling with the oxidation product of a primary aromatic amino silver halide developing agent to form a dye image but which is capable of forming a hydrazone by reaction with a hydra.- zine and selected from the group consisting of aldehydes, ketones, and compounds having two halogen atoms directly linked to the same carbon atom, and n is a positive integer selected from the group consisting of 1 and 2, the cyanoacetyl group comprising the methylene group which acts as coupling function on color development.

8. A photographic emulsion containing silver halide and a color coupler consisting of a cyanoacetylhydrazone of the general formula wherein X represents the radical of a compound which does not contain a group capable of coupling with the oxidation product of a primary aromatic amino silver halide developing agent to form a dye image but which is capable of forming a hydrazone by reacting with a hydrazine and selected from the group consisting of aldehydes, ketones and compounds having two halogen atoms directly linked to the same carbon atom, the cyano acetyl group comprising the methylene group which acts as coupling function on color development.

9. A photographic emulsion containing silver halide and a color coupler consisting of a dicyanoacetylhydrazone of the general formula wherein X represents the radical of a compound which does not contain a group capable of coupounds, the cyano acetyl group comprisinglthe methylene group which acts as coupling function on the color development.

10. A photographic material having at least one light-sensitive silver halide emulsion layer and containing a color coupler consisting of a cyanoacetylhydrazone of the general, formula wherein X represent the radical of a compound which does not contain a group capable of coupling with the oxidation product of a primary .aromatic amino silver halide developing agent to form a dye image but which is capable of forming a hydrazone by reaction with a hydrazine and selected from the group consisting of aldehydes, ketones, and compounds having two halogen atoms directly linked to. the same carbon atom, and n is a positiveinteger selected from the group consisting of, 1 and 2, the cyanoacetyl group comprising the methylene group which acts as coupling function on color development;

. 11. A process for the manufacture of-a colored photographic image, which comprises developing a reducible silver salt image with a vcolor developer comprising a primary aromatic amino silver halide developing agent and a cyanoacetylhydrazone of the general formula wherein X represents the radical of a compound, which does not contain a group capable of coupling with the oxidation product of a primary aromatic amino silver halide developing agent to form a dye image but which is capable of forming a hydrazone by reaction with a hydrazine and selected from the group consisting of aldehydes, ketones, and compounds having two halogen atoms directly linked to the same carbon atom,v and n isa positive integer selected from the group consisting of 1 and 2, the cyanoacetyl group comprising the methylene group which acts as coupling function on color development.

PIERRE JOSEPH MARIE BRUYLANTS.

PHILIBERT LEOPOLD JOZEF RAYMOND MERCKX.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,969,479 Seymour Aug. '7, 1934 2,108,602 Mannes Feb. 15, 1938 2,266,442 Schinzel Dec. 16, 1941 2,375,344 Bruylants .a May 8, 1945

Claims (1)

1. A COLOR-FORMING DEVELOPER COMPRISING A PRIMARY AROMATIC AMINO SILVER HALIDE DEVELOPING AGENT AND AS COLOR COUPLER A CYANOACETYLHYDRAZONE OF THE GENERAL FORMULA