US3369895A - Two equivalent yellow couplers for color photography - Google Patents

Description

United States Patent TWO EQUIVALENT YELLOW COUPLERS FOR COLOR PHOTOGRAPHY Anthony Loria, Ilmari F. Salminen, and Arnold Weissberger, Rochester, N.Y., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey No Drawing. Original application-Aug. 24, 1960, Ser. No. 51,549, now Patent No. 3,277,155, dated Oct. 4, 1966. Divided and this application Dec. 29, 1965, Ser.

18 Claims. (Cl. 96-55) ABSTRACT OF THE DISCLOSURE Two-equivalent yellow dye-forming couplers derived from any of the known 4-equivalent yellow dye-forming couplers by replacing one of the hydrogens on the active methylene group with a fluorine atom are used to advantage as the yellow dye-forming coupler incorporated in light-sensitive silver halide emulsion layers, as the yellow dye-forming coupler in yellow color developer solutions and as the yellow dye-forming coupler in color processes.

This is a divisional application of Loria et al., US. Ser. No. 51.549, filed Aug. 24, 1960, now U.S. Patent 3,277,155.

This invention relates to photography and particularly to a new class of two-equivalent yellow-dye-forming coupler compounds, their preparation by a novel process, and their use in color photography.

The formation of colored photographic images in multilayer elements by coupling the oxidation products of aromatic amino color developing agents with color-forming or coupling compounds is well known. In these processes, the subtractive process for color formation is ordinarily used; and the image dyes are intended to be of the complementary primary colors, cyan or blue-green, magenta, and yellow. The coupler which produce the cyan dyes are usually phenols or naphthols, those producing the magenta dyes are ordinarily pyrazolones, and those producing the yellow dyes are ordinarily compounds containing a methylene group having 2 carbonyl groups attached to it. In multilayer elements for color photography, the cyan couplers are usually incorporated in the red-sensitive layer, the magenta coupler in the greensensitive layer, and the yellow coupler in the blue-sensitive layer. The dyes produced by coupling are azomethine, indamines, or indophenols, depending upon the composition of the coupler and of the developer.

Many of the known couplers are unstable and when incorporated in photographic emulsions are subject to discoloration, an effect called printout when caused by exposure to light over a period of time, or yellowing, an efiect produced by continued exposure of the coupler to heat.

The yellow dyes produced from many of the well known couplers are not as stable as desired when exposed to heat or light for periods of time.

Conventional acetoacetanilide yellow-dye forming couplers have an active methylene group which reacts with oxidized color developer during color development to produce the dyes. These couplers are four-equivalent couplers because they are characterized by requiring the development of four exposed silver halide molecules in order to produce one molecule of dye from a coupler molecule and a developer molecule.

Two-equivalent acetoacetanilide couplers having one of the hydrogen atoms of the active methylene group of each molecule replaced with a chlorine atom have the advantage over the conventional couplers in that they re- Patented Feb. 20, 1968 quire the development of only two silver halide molecules instead of four to produce a molecule of dye. This advantage of the u-chloro couplers is frequently outweighed by the serious disadvantage of a high dye stain produced by these couplers.

Attempts to produce a-fiuoroacetanilide type couplers have previously been unsuccessful. Available methods for preparing these compounds have been tedious and uncertain. Fluorinating agents tend to difluorinate the active methylene group of these compounds. The attempt to prepare monofluoro derivatives by limiting the amount of fiuorinating agent used with respect to the active methylene compound yields only difluorinated and unfluorinated pro-ducts.

It is, therefore, an object of our invention to provide a novel method for preparing yellow-dye forming couplers having one hydrogen of each active methylene group replaced with a fluorine atom.

Another object is to provide a novel class of twoequivalent yellow-dye-forming couplers having a monofluorinated active methylene group.

Another object is to provide a novel class of twoequivalent couplers which has all the advantages of the corresponding monochloro two-equivalent couplers without the disadvantages of the dye stain that characterize many of the monochloro two-equivalent couplers.

Another object is to provide a novel class of yellowdye-forming couplers for color photography that have good stability and also relatively little printout and yellowing upon prolonged exposure to light, heat, and humidity.

Another object is to provide a novel class of yellowdye-forming couplers which produce dyes upon reaction With oxidized color developer, that have valuable spectral absorption properties for color photography.

Still another object is to provide a method for forming yellow dye images in photographic emulsion layers by color development in which our two-equivalent yellowforming couplers are used.

Still another object is to provide photographic silver halide emulsion layers containing our couplers.

Still another object is to provide color developer solutions containing our two-equivalent-yellow dye-forming couplers.

Still further objects will become apparent from the following specification and claims.

We have discovered that these and other objects can be accomplished by using for yellow image formation our novel yellow-dye-forming two-equivalent couplers that are synthesized according to our invention from any of the known four-equivalent yellow-dye-forming couplers. Our couplers are used to advantage in color photographic processing either incorporated in the light-sensitive silver halide emulsion layer of a photographic element or in a color developer solution.

Our yellow-dye-forming couplers contain an active methylene group separating and joined directly to the carbon atoms of two carbonyl groups, one of said carbonyl groups being part of a acyl group or an amide group and the other carbonyl group being part of an acyl group, said active methylene group being the coupling position of said coupler and having substituted thereon a fluorine atom. It is the single fluorine atom on the active methylene group of our couplers which makes our couplers novel and imparts their valuable characteristics. Our couplers include those having the formula:

wherein X represents an alkyl group (substituted'or not),

an aryl group (substituted or not) or a heterocyclic group (substituted or not); Y represents the hydrogen atom, an alkyl group (substituted or not); 11 represents an integer of from 1 to 2; and 2 represents an alkyl group (substituted or not), an aryl group (substituted or not) or a heterocyclic group (substituted or not). Our preferred couplers include those having the formula:

in which R represents an alkyl group having from 1 to 32 carbon atoms which may be a normal alkyl radical having from 1 to 18 carbon atoms, e.g., methyl, propyl, heXyl, octyl, dodecyl, pentadecyl, octadecyl, etc., a secondary alkyl radical in which the secondary carbon atom is attached directly to the carbonyl radical and has attached to it two alkyl radicals each of which may have from 1 to 18 carbon atoms, as defined above, provided that the R group does not have more than a total of 32 carbon atoms,

and includes such groups as l-methylheptadecyl, l-butylheptadecyl, l-decylheptadecyl, l-dodecylheptadecyl, 1- pentadecylhexadecyl, etc a tertiary alkyl radical in which the tertiary carbon atom is preferably attached directly to the carbonyl radical and has attached to it three al-kyl radicals each of which may have from 1 to 18 carbon atoms as defined above, provided that the R group does not have more than a total of 32 carbon atoms and in which one or two of these alkyl radicals attached to the tertiary carbon may themselves be secondary or tertiary alkyl radicals having from 1 to 18 varbon atoms, and includes such groups as a-pivalyl, 1,1-dimethylpropyl, 1,1- dibutylheptadecyl, 1-butyl-l-pentadecylheptadecyl, 1,1-diisobutylheptadecyl, 1,1-di-tert-butylheptadecyl, etc., a tertiary alkyl radical in which one, two or three of the alkyl groups defined above that are attached to the tertiary carbon atom are replaced by alkoxy radicals having from 1 to 18 carbon atoms such as methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, octoxy, nonoxy, decoxy, dodecosy, tridecoxy, tetradecoxy, pentadecoxy, hexadecoxy, octadecosy, etc., or alkoxyalkyl radicals having from 1 to 18 carbon atoms in which the alkoxy and alkyl radicals are among those defined above such as methoxyrnethyl, ethoxymethyl, propoxymethyl, butoxymethyl, hexoxymethyl, decoxymethyl, pentadecoxymethyl, methoxypropyl, methoxyhexyl, methoxyoctyl, methoxydecyl, methoxydodecyl, methoxypentadecyl, nonoxynonyl, etc., and include such groups as l-methoxy-l-butylhexoxy, 1,1-dioctoxyhexadecyl, l-decoxy-l-octoxyhexadecyl, l-methoxyethyll-butoxyethylhexadecyl, etc., or R represents a cyclohexyl radical substituted with an alkyl radical, an alkoxy radical, an alkoxyalkyl radical, each having from 1 to 18 carbon atoms as described above, for example, l-methylcyclohexyl, l-ethylcyclohexyl, l-propylcyclohexyl, 1-octylcyclohexyl, l-dodecylcyclohexyl, l-pentadecylcyclohexyl, l-octadecylcyclohexyl, 2-methylcyclohexyl, 3-ethy1cyclohexyl, 4-octylcyclohexyl, etc., 1 methoxycyclohexyl, 1- ethoxycyclohexyl, 1-propoxycyclohexyl, l-nonoxycyclohexyl, l-octadecoxycyclohexyl, 2-butoXycycloheXyl, etc., 1-methoxymethylcyclohexyl, 1-propoxy methylcyclohexyl, 1-decoxymethylcyclohexyl, 1-pentoxymethylcyclohexyl, 1- methoxydecylcyclohexyl, l-nonoxynonylcyclohexyl, 2-nonoxynonylcyclohexyl, 3-nonoxydecylcyclohexyl, etc., or a cyclohexyl radical substituted with an aryl group such as l-phenylcyclohexyl, l-tloylcyclohexyl, etc., or R represents a bicycloalkyl radical such as a terpenyl radical, e.g., 7,7-dimethylnorbornyl, a 2-alkyl-7,7-dimethylnorbornyl, a 2-alkoxy-7,7-dimethylnorbornyl, a 2-alkoxyalkyl-7,7-dimethylnorbornyl, preferably although not necessarily attached to the carbonyl group through the bridgehead carbon, and in which the alkyl, alkoxy, and alkoxyalkyl substituents may each have from 1 to 18 carbon atoms as defined above, such as 2-methyl-7,7-dimethylnorbornyl, 2-octyl-7,7-dimethynorbornyl, 2-octadecyl-7,7-dimethylnorbornyl, etc., 2-ethoXy-7,7-dimethylnorbornyl, 2-

nonoxy-7,7-dimethylnorbornyl, 2-octadecoxy-7,7-dimethylnorbornyl, etc., 2-methoxybutyl-7,7-dimethylnorbornyl, 2-octoxydecyl-7,7-dimethylnorbornyl, etc., a 2-aryl-7,7- dimethylnorbornyl such as 2-phenyl-7,7-dimethylnorbornyl, 2-tolyl-7,7-dimethylnorbornyl, etc., an aryl radical, e.g., phenyl, an alkphenyl radical in which the alkyl radical has from 1 to 18, carbon atoms, e.g., 3-methylphenyl, 2-butylphenyl, 4-octylphenyl, 2-dodecylphenyl, 3-octadecylphenyl, etc., an alkoxyphenyl radical in which the alkyl group has from 1 to 18 carbon atoms, e.g., 2-methoxyphenyl, 2-propoxyphenyl, 2-hexoxyphenyl, 2-nonoxyphenyl, 2-decoxyphenyl, 2-octadecoxyphenyl, etc., a halophenyl such as 2-chlorophenyl, 2,4,6-tribromophenyl, 2,4,6-trifluorophenyl, etc., a 2-halo-5-alkamidophenyl radical, e.g., 2-chloro-5- Dt- 2,4-di-tert-amylphenoxy acetamido] phenyl, Z-chloro-S- cc- 2,4-di-tert-amylphenoxy) butyramido] phenyl, Z-chloro-S- OL- (2,4-di-tert-amylphenoxy) amylamido] phenyl, Z-chloro-S- [7- 2,4-di-tert-amylphenoxy butyramido] phenyl, Z-chloro-S-(4-rnethylphenylsulfonamido)phenyl, Z-fiuoro-S-(N-hexylamido)phenyl, etc.,

a Z-methoxy-S-alkamidophenyl radical, e.g.,

2-methoxy-5 2,4-di-tert-amylphenoxy) acetamidophenyl,

Z-methoxy-S- [OL- (2,4-ditert-amylphenoxy butyramido] phenyl, etc.,

a 4-alkamidophenyl radical, e.g.,

4- 2,4-di-tert-amylphenoxy) acetamidophenyl,

4 ['y- 2,4-di-tert-amylphenoxy butyramido phenyl, etc.,

a 4-methoxyphenyl radical, e.g.,

4- [N- ('y-phenylpropyl) -N- (p-tolyl) -carbamylmethoxy] phenyl,

4- [N- ('y-phenylheXyl) -N- (p-tolyl carbamylmethoxy] phenyl, etc.,

a 4-sulfamylphenyl radical, e.g.,

4-[N-(7-phenylpropy1) -N-(p-tolyl) sulfamyl]phenyl,

4- [N- (phenylethyl -N- p-tolyl) sulfamyl] phenyl, etc.,

a 2-chloro-5-sulfonamidophenyl radical, e.g.,

Z-chloro-S-(p-toluenesulfonamido)phenyl,

2-chloro-5-(benzenesulfonamido)phenyl, etc.,

a 3,5-dicarboxyphenyl radical,

esters of 3,5-dicarboxyphenyl radicals, e.g.,

3,S-dicarbomcthoxyphenyl,

3,5-dicarbohexoxyphenyl,

3,S-dicarbododecoxyphenyl,

3,5-dicarbopentadacoxyphenyl,

3,S-dicarbooctadecoxyphenyl, etc.,

a Z-phenoxy-S-carbamylphenyl radical, e.g.,

2-(2,4-di-tert-amylphenoxy)-5-(3,5-dicarbomethoxyphenylcarb amyl phenyl,

2- 2,4-di-tert-amylphenoxy -5- (N-morpholinocarb onyl) phenyl, etc.,

a 3,5-dicarbamylphenyl radical, etc.,

a heterocyclic radical, e.g., a benzofuranyl radical, a furanyl radical, a thiazolyl radical, a benzothiazolyl radical, a naphthothiazolyl radical, an oxazolyl radical, a benzoxazolyl radical, an imidazolyl radical, a benzimidazolyl radical, a quinolinyl radical, etc.; where n is the integer 1 or 2; and R represents an aryl radical such as phenyl, alkoxyphenyl in which the alkyl radical may have from 1 to 18 carbon atoms as defined above for R, halophenyl radicals such as 2-chlorophenyl, 2,4-dichlorophenyl, 2,4,6- trichlorophenyl, the corresponding bromoand corresponding fiuorophenyl radicals, etc., a 2-halo-5-alkamidophenyl radical, e.g.,

Z-chloro-S- Ot- (2,4-di-tert-amylphenoxy) acetamido] phenyl,

2-chl0r0-5- [OL- 2,4-di-tert-amylphenoxy butyramido] phenyl,

2-chloro-5- Ot- 2,4-di-tert-amylphenoxy amylarnido] phenyl,

2-chloro-5- ['y- (2,4-di-tert-amylphenoxy butyramido] phenyl,

2-chloro-5- (4-methylphenylsulfonamido) phenyl,

2-fiuoro-5-(N-hexylamido)phenyl, etc.,

a 2-methoxy-5-alkamidophenyl radical, e.g.,

2-methoxy-5- 2,4-di-tert-amylphenoxy) acetamidophenyl,

2-methoxy-5-[a-(2,4-di-tert-amylphenoxy)butyramido] phenyl, etc.,

a 4-alkarnidophenyl radical, e.g.,

4-(2,4-di-tert-amylphenoxy) acetamidophenyl,

4-['y-(2,4-di-tert-amylphenoxy)butyramido1phenyl, etc.,

a 4-methoxyphenyl radical, e.g.,

4 [N- ('y-phenylpropyl) -N- (p-tolyl) -carbamylmethoxy] phenyl,

4- [N- ('y-phenylhexyl) -N- (p-tolyl) carbamylmethoxy] phenyl, etc.,

a 4-sulfamylphenyl radical, e.g.,

4-[N-(v-phenylpropyl)-N-(p-tolyl)sulfamyl1phenyl,

4- [N- (phenylethyl -N- (p-tolyl sulfamyl] phenyl, etc.,

a 2-chloro-5-sulfonamidophenyl radical, e.g., 2-chloro-5- (p-toluenesulfonamido)phenyl, 2 chloro-S-(benzenesulfamid)phenyl, etc., a 3,5-dicarboxyphenyl radical, esters of 3,5-dicarboxyphenyl radicals, e.g., 3,5-dicarbo-methoxyphenyl, 3,S-dicarbohexoxyphenyl, 3,5-dicarbod odecoxyphenyl, 3,5-dicarbopentadecoxyphenyl, 3,5-dicarbooctadecoxyphenyl, etc., a Z-phenoxy-S-carbamylphenyl radical, e. g., 2- 2,4-di-tert-amylphenoxy) 3,5 -dicarbomethoxyphenylcarbamyl phenyl, 2- 2,4-di-tert-amylphenoxy) -5- (N-rnorpholinocarbonyl)phenyl, etc., a 3,5-dicarbamylphenyl radical, etc., or an alkyl group of 1 to 18 carbon atoms, preferably a long-chain alkyl of to 18 carbon atoms, e.g., stearyl an alkoxy group having from 1 to 18 carbon atoms.

The following specific examples are representative of our couplers and will serve to illustrate them.

a-{3- a- (2,4-di-tert-amylphenoxy) butyramid'o benzoylyaflu oro-2-meth'oxyacetanilide COUPLER 2 I 091350 0 CH0 ONHCaH5 a-Benzoyl-a-fluoroacetanilide COUPLER 3 l ctr-no 0 CH0 ONE-Q a-Benzoy1-a-fiuoro-2-methoxyacetanilide COUPLER 4 Ethyl-e-benzoyl-a-fluoroacetate COUPLER 5 ITIHCO (CH2) 30 051111 r cnmocoono onn 6 COUPLER 6 1 l canto 0 one ONHSO2N OHa aBenzoyl-u-fiuoro-4-{ [N- (p-tolyl) -N- (v-phenyl) propyl] -sulfamyl} acetanilide COUPLER 7 CH3 CsHn (l7) a-Fluoro -a- (o-methoxyb enzoyl -4- a- (di-tertamylphenoxy) -n-butyramido] acetanilide According to our invention our couplers are prepared by treating the sodium enolate of the parent coupler having the formula:

wherein R, R and n have the values given above, with perchloryl fluoride under conditions which favor the separation of the monofluoro derivative having the Formula I from the reaction mixture immediately on formation. This is accomplished by adding a solution of the sodium salt of the parent coupler slowly to perchloryl fluoride dissolved in methyl alcohol and maintaining the reacting mixture at 45 to -20 C. by an acetone-Dry Ice bath. The monofluoride coupler precipitates out of the solution as it is formed with the result that none of the difiuorinated compound is produced. The reaction mixture is then allowed to warm up to about 10 over a period of time during which the monofluorinated coupler dissolves, and then the mixture is added to ice water. The monofluorinated coupler which precipitates is filtered, washed with cold water, and air dried.

The detailed synthesis of representative Couplers 1 through 7 are described in Loria Salminen and Weissberger U.S. Ser. No. 51,549, filed Aug. 24, 1960, now U.S. Patent 3,277,155.

Some of the couplers of our invention are difrusible and are especially suited for use in developer solutions for developing the yellow-dye image in exposed color photographic film which does not contain incorporated yellow coupler. Our couplers of this type are illustrated by Couplers 2, 3 and 4.

The other couplers of our invention are nondiifusing and are especially suited for incorporation in silver halide emulsion layers for color photography. Upon exposure, such emulsions containing our couplers are developed with conventional color developing solutions which do not contain yellow forming coupler.

The following composition illustrates a developer solution in which one of our couplers is used.

DEVELOPER 1 G. Sodium hydroxide 4.0 Sodium sulfite 10.0 a-Benzoyl-a-fluoroacetanilide (Coupler 2) 1.5 2-amino-5-diethylaminotolnene hydrochloride 2.5

Water to 1 liter.

Any color-forming developer containing a primary aromatic amino developing agent may be used. These include developers having two primary amino groups as well as those having one of the amino groups substituted, or having substituents in the ring such as alkylphenylenediamines and alkyltoluenediamines. These compounds are usually used in the salt form such as the hydrochloride and the sulfate which are more stable than the amines themselves. Suitable developing agents are diethyl-p-phenylenediamine hydrochloride, monomethyl-p-phenylenediamine hydrochloride, dirnethyl-p-phenylenediamine hydrochloride, 2- amino diethylaminotoluene hydrochloride, N- ethyl N (/3 methanesulfonamidoethyl) 4 aminoaniline sulfate, N ethyl N (B methanesulfonamidoethyl) 3 methyl 4 aminoaniline sulfate, and 4- amino N ethyl N (B methanesulfonamideoethyl)- m-toluidine sesquisulfate monohydrate. The p-aminophenols and their substitution products may also be used where the amino group is unsubstituted. All of these groups have unsubstituted amino groups which enable the oxidation products of the developer to couple with the color-forming compounds to form a dye image.

The following example will serve to illustrate a typical way in which our couplers are used in color developers for developing yellow dye images in exposed silver halide emulsion layers.

Exwmple l A film coated with an ordinary silver bromoiodide emulsion for color photography was exposed under an image at 125th of a second with light having a color temperature of 3,000 K. and developed for ten minutes in a developer having the composition of Developer 1. Then the silver image and the residual silver halide was removed by treating the film for five minutes in a conventional potassium ferricyanide-potassium bromide bleach followed by fixing in a conventional hypo fixing bath for five minutes. After a ten minute final wash, the film was dried. The result was a negative dye image having a A-max. value of 440 m Similarly, other diffusible couplers of our invention have been used in developer solutions such as Developer 1 to develop yellow dye images as in Example I. For example, a developer solution containing Coupler 3 produced a dye image having a A-max. value of 447 mg, and Coupler 4 a dye image having a A-max. value of 450* m The couplers of our invention which are adapted especially for incorporation in emulsion layers for color photography are particularly valuable because in this application full advantage can be made of their low printout and low yellowing tendencies and their twoequivalent characteristic. Emulsions containing our couplers are coated on transparent supports, such as glass, cellulose esters, etc., or on a nontransparent reflecting material, such as paper, opaque cellulose esters, etc.

Our couplers are incorporated in light-sensitive silver halide emulsion layers as described in M-annes and Godowsky, U.S. Patent 2,304,940 or in Jelley and Vittum U.S. Patent 2,322,027. A wide range of coupler to coupler incorporating solvent ratios may be used. For example, this ratio may range from 1:3 to 1:0. The preferred range of coupler to coupler solvent ratios is from 1: /z to 12%.

Any of the standard emulsion addenda may be used in the emulsions containing our couplers such as the emulsion addenda disclosed in Dann and Gates US. Patent 3,062,646, issued Nov. 6, 1962.

Photographic emulsions containing our couplers are color developed by developer solutions containing any of the well-known primary aromatic amino silver halide developing agents such as have been described above. Variations in concentration and composition such as is described in Developer 1 may also be made in developers used for developing emulsions containing our couplers.

Typical developers containing these developing agents are as follows:

8 DEVELOPER 2 G. 2-amino-5-diethylaminotoluene hydrochloride 2.5 Sodium sulfite (anhydrous) 5.0 Sodium carbonate (anhydrous) 20 .0 Potassium bromide 2.0 Water to 1 liter.

DEVELOPER 3 G. N ethyl N-(B-methanesulfonamidoethyl)-3-methyl-4-aminoaniline sulfate 2.0 Sodium sulfite (anhydrous) .6 Sodium carbonate (anhydrous) 30.0

Water to 1 liter.

Our invention is further illustrated by the following specific examples showing how our couplers are incorporated in photographic emulsions and then used to produce yellow dye images having valuable light absorption characteristics for color photography.

Example II 25 ml. of a dispersion of 1 g. of Coupler 1 and 0.5 g. of di-n-butylphthalate coupler solvent in 2.2 g. of gelatin was mixed with 5 ml. of a conventional medium-speed silver bromoiodide emulsion, and the mixture was coated on a suitably-subbed cellulose acetate support. After being dried, the coating was exposed under an image and developed in Developer 3 to form a negative silver and yellow dye image. The silver image and the residual silver halide were removed by treatment with a conventional ferricyanide bleaching followed by a hypo fixing bath leaving a yellow negative image having a A-max. of 444 m and exhibiting good absorption characteristics.

Example III Another film sample coated with the above emulsion in which an equal amount of Coupler 5 was used in place of Coupler 1 was exposed and given the same processing as was used in Example 11 to produce a yellow dye image having a A-max. value of 444 III/1. with very desirable absorption characteristics.

The dyes formed by the reactions of our couplers with oxidized color developer are characterized by having not only very desirable \-max. values but by having good stability to prolonged exposure to light and to heat. These characteristics are illustrated by the following table which lists the A-max. values and the amount of light fading produced by 30 hours exposure to an Xenon Arc Fade ometer and the amount of heat-fading produced by one weeks storage at F. and 75 percent relative humidity in density units.

TABLE I Light Fading in Heat Fading in Density Units Density Units Coupler Developer )l-max. Produced by 30 Produced by 1 Formula in m Hours Exposure Week's Storage to Xenon Arc at 140 F. Fadeometer 75% RH 1 Developer 2 448 .60 .0 1 Developer 3. 444 58 02 2 Developer 1 440 12 14 3. .do 447 .36 02 4 do 450 5 Developer 2 448 l3 0 5 Developer 3 444 11 O TABLE II in Yellowing Measured in "Printout Measured Change in Light Trans- Change in Light Transmis- From this table it can be seen that only a very small amount of printout was produced by 30 hours of exposure to the Xenon Arc Fadeometer and that no yellowing was produced at all by storage at 140 F. and 75 percent RH.

The monofluoro couplers of our invention are distinguished from the corresponding monochloro coupler derivatives by not producing yellow fog in the yellow image layer during the development process which is characteristic of many of the monochloro couplers.

Our couplers are not only valuable for the characteristics which have been described above but because they are two-equivalent. Two-equivalent couplers are particularly valuable for incorporation in photographic emulsion layers because the production of a given amount of dye with an emulsion coating of two-equivalent coupler requires only one-half the amount of silver halide that is required in an emulsion incorporating a conventional coupler. This means that not only can emulsions containing two-equivalent couplers be produced more economically but they can be made in thinner coatings. It is known that image definition and sharpness can be improved by reducing the thickness of image-bearing emulsion layers.

The novel fiuorination process of our invention is characterized by providing a direct and simple method for producing valuable monofluorinated yellow-dye-forming couplers which have previously been impossible to make. The diifusing couplers of our invention are valuable for use in color developer solutions, while the nondiifusing couplers are valuable for incorporation in emulsion layers for color photography. Photographic emulsion layers containing our couplers are characterized by producing very low printout upon prolonged exposure to strong light and extremely little or no yellowing upon prolonged exposure to high temperatures and high humidity. The dyes formed by use of our yellow-dye forming monofluorinated couplers have very desirable absorption characteristics and show good stability to prolonged exposure to strong light and high temperatures at high humidities. Our couplers are distinguished from the corresponding monochloro couplers by not producing yellow fog during the development process that is characteristic of many of the monochloro couplers.

This invention has been described in detail with particular reference to preferred embodiments thereof but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. In a process for forming a yellow-dye image in an exposed light-sensitive silver halide emulsion layer comprising the step of developing the said exposed layer with an aqueous alkaline solution of a primary aromatic amino developing agent in the presence of a yellow-dye forming coupler containing an active methylene group separating and joined directly to the'carbon atoms of two carbonyl groups, one of said carbonyl groups being part of a group selected from the class consisting of an acyl group and an amide group and the other of said carbonyl groups being part of an acyl group, said active methylene group being the coupling position of said coupler, the improvement wherein said yellow-dye-forming coupler of said process has a fluorine atom substituted on the said active methylene group of said coupler.

10 2. The process of claim 1 in which the yellow-dyeforming coupler has the formula:

wherein X represents a member selected from the class consisting of hydrogen, an alkyl group, an aryl group, and a heterocyclic group; Y represents a member selected from the class consisting of hydrogen, and an alkyl group; n represents an integer of from 1 to 2; and Z represents a group selected from the class consisting of an alkyl group, an aryl group, and a heterocyclic group.

3. The process of claim 1 for forming dye images in which the yellow-dye-forming coupler has the formula:

wherein R is selected from the class consisting of an alkyl group, a cycloalkyl group, a bicycloalkyl group, an aryl group, and a heterocyclic group; n is an integer from 1 to 2; R represents a group selected from the class consisting of a phenyl group and an alkyl group.

4. The process of claim 1 for forming yellow-dye images in which the yellow-dye-forming coupler is @{3 [oz-(2,4-di-t6ft amylphenoxy)butyramido]benzolyl}- a-fiuoro-2-methoxy. acetanilide.

, 5. The process of claim 1 for forming yellow-dyeimages in which the yellow-dye-forming coupler is ubenzoyl-a-fiuoroacetanilide.

6. The process of claim 1 for forming yellow-dye images in which the yellow-dye-forming coupler is w benzoyl-a-fiuoro-2-methoxy acetanilide.

7. The process of claim 1 for forming yellow-dye images in which the yellow-dye-forming coupler is ethylu-benzoyl-a-fluoroacetate.

8. The process of claim 1 for forming yellow-dye images in which the ye'llow-dye-forming coupler is cafluoro-u-pivalyl-5-['y-(2-,4-di tert amylphenoxy butyramido]-2chloroacetanilide.

9. In a yellow color developing solution containing an alkali, a color developing agent and a yellow-dye-forming coupler containing an active methylene group separating and joined directly to the carbon atoms of two carbonyl groups, one of said carbonyl groups being part of a group selected from the class consisting of an acyl group and an amide group and the other of said carbonyl groups being part of an acyl group, said active methylene group being the coupling position of said coupler, the improvement wherein said yellow-dye-forming coupler of said yellow color developing solution has a fluorine atom substituted on the said active methylene group of said coupler.

10. A yellow color developer solution of claim 9 in which the yellow-dye-torming coupler has the formula:

0 X(i(lJH( J ITT Z F Y n-l wherein X represents a member selected from the class consisting of hydrogen, an alkyl group, an aryl group, and a heterocyclic group; Y represents a member selected from the class consisting of hydrogen, and an alkyl group; n represents an integer of from 1 to 2; and Z represents a group selected from the class consisting of an alkyl group, an aryl group, and a heterocyclic group.

1 1. A yellow color developer solution of claim 9 in WhlCh the yellow-dye-forrning coupler has the formula:

wherein R is selected from the class consisting of an alkyl group, a cycloalkyl group, a bicycloalkyl group, an aryl lll group, and a heterocyclic group; n is an integer from 1 to 2; R represents a group selected from the class consisting of a phenyl group and an alkyl group.

12. The yellow color developer solution of claim 9 in which the yellow-forming coupler is a-benzoyl-a-fluoroacetanilide.

13. The yellow color developer solution of claim 9 in which the yellow-forming coupler is u-benzoyl-a-fluoro-2- methoXy acetanilide.

14. The yellow color developer solution of claim 9 in which the yellow-forming coupler is ethyl-u-benzoyla-fluoroacetate.

15. In a light-sensitive silver halide emulsion layer containing a yellow-dye-forming coupler containing an active methylene group separating and joined directly to the carbon atoms of two carbonyl groups, one of said carbonyl groups being part of a group selected from the class consisting of an acyl group and an amide group and the other of said carbonyl groups being part of an acyl group, said active methylene group being the coupling position of said coupler, the improvement wherein said yellowdye-forming coupler of said light-sensitive layer has a fluorine atom substituted on the said active methylene group of said coupler.

16. A light-sensitive silver halide layer of claim 1'5 in which the yellow-dye-forming coupler has the formula:

(DH-( 5 -N -z t t wherein X represents a member selected from the class consisting of hydrogen, an alkyl group, an aryl group, and a heterocyclic group; Y represents a member selected from the class consisting of hydrogen, and an alkyl group; n represents an integer of from 1 to 2; and Z represents a group selected from the class consisting of an alkyl group, an aryl group, and a heterocyclic group.

17. The light-sensitive silver halide layer of claim 15 in which the yellow-dye-forming coupler is oc{3[oc(2,4-ditert-amylphenoxy)butyramido]benzoyl} a fluoro 2- methoxy acetanilide.

18. The light-sensitive silver halide layer of claim 15 in which the yellow-dye-forming coupler is d-fiuo'ro-apivalyl-S-[' -(Z-A-di-tert arnylphenoxy butyrarnido] 2- chloroacetanilide.

References Cited UNITED STATES PATENTS 3,277,155 10/1966 Loria et a1. 96-400 NORMAN G. TORCHIN, Primary Examiner.

J. TRAVIS BROWN, Examiner.