Yellow couplers having ionizable and/or solubilizing aaryloxy coupling-off groups.

Abstract

 Novel yellow dye-forming couplers, and photographic elements, emulsions and processes for developing images utilizing the novel couplers, are disclosed. The novel couplers include (a) an acyl acetanilide in which said acyl group includes a multicyclic carbon center attached to the carbonyl moiety, and (b) an aryloxy coupling-off group at the coupling position of the acyl acetanilide, said coupling-off group having at least one substituent which is an ionizable group or a solubilizing group.

Description

Technical Field

[0001] This invention pertains to a new class of yellow dye- forming couplers and to silver halide color photographic light-sensitive elements, emulsions and processes comprising such couplers. More specifically, the invention pertains to a new class of yellow couplers having a multicyclic carbon center attached to the 2- position of a substituted phenyl carbamoyl acetyl group and a coupling-off group having a hydrophilic functional group.

[0002] It is well known in the photographic art that color images are customarily obtained by reaction between an oxidized aromatic primary amine developer and a color forming coupler. Typically, yellow dye-forming couplers are open chain ketomethylene compounds which yield azomethine dyes upon coupling with an oxidized developer. The most common yellow couplers are acylacetanilides, such as pivaloylacetanilides and benzoylacetanilides. Pivaloylacetanilide yellow couplers which are frequently used in the art have, in general, low coupling efficiencies due to their high pK_a values. To overcome this problem, benzoylacetanilide couplers have been proposed and employed in the art. However, benzoylacetanilide yellow couplers yield image dyes with very poor light stability.

[0003] The foregoing classes of yellow couplers are described, for example, in U.S. Patent Nos. 2,298,443; 2,407,210; 2,875,057; 3,048,194; 3,265,506; 3,447,928; 4,157,919; 4,230,851; 4,327,175; and 4,529,691, and in "Farbkuppler - ein Literaturü bersicht," published in AGFA MITTEILUNGEN, Band III, pp. 112-126 (1961).

[0004] A class of yellow couplers containing an adamantoyl group, such as adamantoylacetanalides, was disclosed in U.S. Patent No. 4,336,327. The disclosed couplers were characterized by improved light fastness over the corresponding pivaloylacetanilides. Nevertheless, the adamantoylacetanalide yellow couplers are characterized by unsatisfactory coupling efficiency.

[0005] To enhance the coupling efficiency, 2-equivalent yellow couplers containing a substituent in the coupling position, known as a coupling-off group (COG), are disclosed and employed in the art. Although some 2- equivalent adamantoylacetanilide yellow couplers are known, for example from U.S. Patent No. 4,336,327, the coupling activity of such couplers is still unsatisfactory.

[0006] There has thus been a continuing need for novel couplers which improve upon existing couplers, as well as for novel couplers which optimize photographic properties such as coupling activity and image-dye light stability. It would be highly desirable to provide new coupling-off groups capable of enhancing the coupling efficiency of adamantoylacetanilide-class yellow couplers.

Disclosure of the Invention

[0007] These needs have been satisfied by providing a yellow dye-forming coupler comprising an acyl acetanilide in which the acyl group includes a multicyclic carbon center attached to the carbonyl moiety, and an aryloxy coupling- off group at the coupling position of the acyl acetanilide, the coupling-off group having at least one substituent which is an ionizable group or a solubilizing group.

[0008] It has now been discovered that an aryloxy coupling- off group having at least one ionizable or solubilizing substituent significantly enhances the coupling efficiency and image-dye light stability of this class of yellow couplers.

[0009] In another embodiment, the invention relates to a photographic element comprising a support and a silver halide emulsion layer having associated therewith a yellow dye-forming coupler as described above.

[0010] In yet another embodiment, this invention relates to a process for developing an image in a photographic element by developing it in the presence of a yellow dye- forming coupler as described above.

[0011] In still another embodiment this invention relates to a photographic silver halide emulsion comprising a yellow dye-forming coupler as described above.

Detailed Description of the Invention

[0012] The yellow dye-forming coupler according to the invention comprises an acyl acetanilide in which the acyl group includes a multicyclic carbon center attached to the carbonyl moiety, and an aryloxy coupling-off group at the coupling position of the acyl acetanilide. According to the invention, the aryloxy coupling-off group has at least one substituent which is an ionizable group or a solubilizing group. The term "multicyclic carbon center" as used herein denotes a carbon atom which is part of two or more non-aromatic ring systems. The term "ionizable substituent" denotes a substituent which contains at least one acidic hydrogen that ionizes substantially at the processing pH of the color developer. The term "solubilizing substituent" denotes a substituent which has a hydrophilic character and ionizes completely at the processing pH of the color developer.

[0013] Preferred yellow dye-forming couplers according to the invention can be represented by the formula


wherein

R⁰

denotes

R¹

denotes an ionizable or solubilizing group;

v

denotes an integer from 1 to 3;

X

denotes the atoms necessary to complete a phenyl or naphthyl ring system;

Y

denotes hydrogen, halogen, CN, CF₃, C(O)_nR², CR²R³C(O)_nR², CR²R³CONR²R³, COO(CH₂CH₂O)_pR², CONR²R³, CONR²(CH₂CH₂-O)_pR³, NO₂, NR²S(O)_nR³, NR²S(O)_nNR²R³, NR²COR³, NR²COCH(R²)(OR³), NR²CONR²R³, OR², O(CH₂)_qR², O(CH₂CH₂O)_pR², O(CH₂CH₂O)_pCOOR², O(CH₂CH₂O)_pCONR²R³, S(O)_nR², S(O)_nNR²R³, or S(O)_nNR²(CH₂CH₂-O)_pR³;

R²,R³

independently denote hydrogen or unsubstituted or substituted alkyl, aryl or heterocyclyl, or together complete a heterocyclic ring with the nitrogen or oxygen atoms to which they are attached;

n

denotes 1 or 2;

p, q,

independently denote an integer from 1 to 3; and

r

denotes an integer from 1 to 4.

[0014] Each substituent Y is independently the same or different.

[0015] As R⁰, the adamantyl, bicyclo[2.2.1]heptyl and bicyclo[2.2.2]octyl groups can be unsubstituted or substituted.

[0016] Exemplary ionizable/solubilizable groups include:
   -OH -NH-C₂H₄-OH -N(C₂H₄-OH)₂ -COOH -NH-C₃H₆-COOH -N(C₂H₄-COOH)₂ -N(SO₂-C₂H₄-OH)₂ -NHSO₂-C₂H₄-OH -SO₂NH-C₂H₄-OH -SO₂N(C₂H₄OH)₂ -N(SO₂-C₂H₄-COOH)₂ -NHSO₂-C₂H₄-COOH


wherein p = 1 or 2.

[0017] In general, the alkyl and aryl portions of the foregoing groups contain 1 to 20 carbon atoms (alkyl) and 6 to 20 carbon atoms (aryl). They can be substituted with halogen, hydroxy, cyano, carboxy, alkoxy, aryloxy, alkoxycarbonyl, aryloxycarbonyl, amido (-NR²COR³), carbamoyl (CONR²R³), alkylsulfinyl, alkylsulfonyl, hydroxyalkylsulfonyl, sulfonamido (NR²SO₂R³), and sulfamoyl (SO₂NR²R³).

[0018] Preferred coupling-off groups include the following:


   Exemplary embodiments of yellow couplers within the scope of the present invention are given below:












   The known 2-equivalent adamantoylacetanilide-class yellow couplers containing hydrophobic COGs, such as those disclosed in U.S. Patent No. 4,336,327, do not show good coupling efficiency in practical use in color photographic products. It has unexpectedly been discovered that by changing the disclosed hydrophobic COGs to hydrophilic COGs, the coupling efficiency of this class of couplers is significantly improved. Likewise, other yellow couplers having multicyclic substituents, as described above, display unexpectedly improved coupling efficiency.

[0019] Preferably, the couplers according to the invention are incorporated in silver halide emulsions and the emulsions are coated on a support to form a photographic element. Alternatively, the inventive couplers can be incorporated in photographic elements adjacent the silver halide emulsion where, during development, the coupler will be in reactive association with development products such as oxidized color developing agent. Thus, as used herein, the term "associated therewith" signifies that the coupler is in a silver halide emulsion layer or in an adjacent location where, during processing, it will come into reactive association with silver halide development products. The amount of coupler to be incorporated in an emulsion is generally between about 5 x 10⁻⁴ and 5 x 10⁻³ mol/m².

[0020] In a preferred embodiment, the inventive coupler can be ballasted. Ballast groups, if employed, comprise groups of such molecular size and configuration as to render the inventive coupler nondiffusible as described, for example, in U.S. Patent Nos. 4,420,556 and 4,923,789. Advantageous ballast groups include alkyl and aryl groups having from about 8 to 32 carbon atoms.

[0021] Unballasted couplers can be used in a Kodachrome-type process.

[0022] In the following discussion of suitable materials for use in the emulsions and elements according to the invention, reference will be made to Research Disclosure, December 1989, Item 308119, published by Kenneth Mason Publications Ltd., Emsworth, Hampshire PO10 7DQ, U.K., the disclosures of which are incorporated herein in their entireties by reference. This publication will be identified hereafter as "Research Disclosure".

[0023] The support of the element of the invention can be any of a number of well known supports for photographic elements. These include polymeric films, such as cellulose esters (for example, cellulose triacetate and diacetate) and polyesters of dibasic aromatic carboxylic acids with divalent alcohols (such as polyethylene terephthalate), paper, and polymer-coated paper.

[0024] The photographic elements according to the invention can be coated on the selected supports as described in Research Disclosure Section XVII and the references cited therein.

[0025] The radiation-sensitive layer of a photographic element according to the invention can contain any of the known radiation-sensitive materials, such as silver halide, or other light sensitive silver salts. Silver halide is preferred as a radiation-sensitive material. Silver halide emulsions can contain for example, silver bromide, silver chloride, silver iodide, silver chlorobromide, silver chloroiodide, silver bromoiodide, or mixtures thereof. The emulsions can include coarse, medium, or fine silver halide grains bounded by 100, 111, or 110 crystal planes.

[0026] The silver halide emulsions employed in the elements according to the invention can be either negative-working or positive-working. Suitable emulsions and their preparation are described in Research Disclosure Sections I and II and the publications cited therein.

[0027] Also useful are tabular grain silver halide emulsions. In general, tabular grain emulsions are those in which greater than 50 percent of the total grain projected area comprises tabular grain silver halide crystals having a grain diameter and thickness selected so that the diameter divided by the mathematical square of the thickness is greater than 25, wherein the diameter and thickness are both measured in microns. An example of tabular grain emulsions is described in U.S. Patent No. 4,439,520. Suitable vehicles for the emulsion layers and other layers of elements according to the invention are described in Research Disclosure Section IX and the publications cited therein.

[0028] The radiation-sensitive materials described above can be sensitized to a particular wavelength range of radiation, such as the red, blue, or green portions of the visible spectrum, or to other wavelength ranges, such as ultraviolet, infrared, X-ray, and the like. Sensitization of silver halide can be accomplished with chemical sensitizers such as gold compounds, iridium compounds, or other group VIII metal compounds, or with spectral sensitizing dyes such as cyanine dyes, merocyanine dyes, or other known spectral sensitizers. Exemplary sensitizers are described in Research Disclosure Section IV and the publications cited therein.

[0029] Multicolor photographic elements according to the invention generally comprise a blue-sensitive silver halide layer having a yellow color-forming coupler associated therewith, a green-sensitive layer having a magenta color-forming coupler associated therewith, and a red-sensitive silver halide layer having a cyan color- forming coupler associated therewith. Color photographic elements and color-forming couplers are well-known in the art. in Research Disclosure Section VII, paragraphs D, E, F and G and the publications cited therein. These couplers can be incorporated in the elements and emulsions as described in Research Disclosure Section VII, paragraph C and the publications cited therein.

[0030] A photographic element according to the invention, or individual layers thereof, can also include any of a number of other well-known additives and layers. These include, for example, optical brighteners (see Research Disclosure Section V), antifoggants and image stabilizers (see Research Disclosure Section VI), light-absorbing materials such as filter layers of intergrain absorbers, and light-scattering materials (see Research Disclosure Section VIII), gelatin hardeners (see Research Disclosure Section X), oxidized developer scavengers, coating aids and various surfactants, overcoat layers, interlayers, barrier layers and antihalation layers (see Research Disclosure Section VII, paragraph K), antistatic agents (see Research Disclosure Section XIII), plasticizers and lubricants (see Research Disclosure Section XII), matting agents (see Research Disclosure Section XVI), antistain agents and image dye stabilizers (see Research Disclosure Section VII, paragraphs I and J), development-inhibitor releasing couplers and bleach accelerator-releasing couplers (see Research Disclosure Section VII, paragraph F), development modifiers (see Research Disclosure Section XXI), and other additives and layers known in the art.

[0031] Photographic elements according to the invention can be exposed to actinic radiation, typically in the visible region of the spectrum, to form a latent image as described in Research Disclosure Section XVIII, and then processed to form a visible dye image as described in Research Disclosure Section XIX. Processing can be any type of known photographic processing, although it is preferably carried out at a pH of 9 to 14 and includes a nucleophile such as hydrogen peroxide, hydroxylamine, perborate, an alkyl peroxide, an aryl peroxide, or a compound releasing such nucleophiles.

[0032] A negative image can be developed by color development using one or more of the aforementioned nucleophiles. A positive image can be developed by first developing with a nonchromogenic developer, then uniformly fogging the element, and then developing by a process employing one or more of the aforementioned nucleophiles. If the material does not contain a color- forming coupler compound, dye images can be produced by incorporating a coupler in the developer solutions.

[0033] Development is followed by the conventional steps of bleaching, fixing, or bleach-fixing, to remove silver and silver halide, washing and drying. Bleaching and fixing can be performed with any of the materials known to be used for that purpose. Bleach baths generally comprise an aqueous solution of an oxidizing agent such as water soluble salts and complexes of iron (III) (such as potassium ferricyanide, ferric chloride, ammonium or potassium salts of ferric ethylenediaminetetraacetic acid), water-soluble dichromates (such as potassium, sodium, and lithium dichromate), and the like. Fixing baths generally comprise an aqueous solution of compounds that form soluble salts with silver ions, such as sodium thiosulfate, ammonium thiosulfate, potassium thiocyanate, sodium thiocyanate, thioureas, and the like.

[0034] The invention is further illustrated by the following examples, without being limited thereby.

Synthesis Example: Preparation of coupler Y-3

[0035] The coupler is prepared according to the following reaction scheme:


   A solution of ethyl 3-(1-adamantyl)-3-oxopropionate (A) (10.0 g, 0.04 mole) and n-dodecyl 4-chloro-3- aminobenzoate (B) (13.6 g, 0.04 mole) in toluene (100 ml) was heated and refluxed for 3 hours. After distilling off 50-60 ml toluene, 100 ml heptane was added to the hot mixture. Upon cooling to room temperature, a mass of white solid crystallized out. The solid was collected and dried to yield 4-equivalent coupler (C) (17.4 g, 80% yield), m.p. 96-97° C.

[0036] To a stirred solution of coupler (C) (13.6 g, 0.02 mole) in dichloromethane (50 ml) at room temperature was slowly added sulfuryl chloride (3.5 g, 0.026 mole). After stirring for 1.5 hours, the solvent was removed under reduced pressure to give a clear colorless oil. TLC (heptane-ethyl acetate, 2:1) showed only one product spot. Chlorinated product (D) thus obtained was used in the next stage of the reaction sequence without further purification.

[0037] Next, to a suspension of chlorinated product (D) (8.1 g, 0.014 mole) in DMF (250 ml) was added a solution of sulfonyl bisphenol (E) (20 g, 0.12 mole) and triethylamine (12.1 g, 0.12 mole). The mixture was stirred at room temperature overnight, then poured into a stirring mixture of ethyl acetate (300 ml) and water (500 ml) in which was dissolved potassium carbonate (15 g). After stirring for 30 minutes, the ethyl acetate layer was separated from the aqueous layer and dried over anhydrous magnesium sulfate. The ethyl acetate solvent was distilled off under reduced pressure to about one third its volume. Heptane was then added until it just turned cloudy. The mixture was heated, filtered and the product allowed to crystallize out at room temperature. The white solid was collected and dried to give coupler Y-3 (F) (8.0 g, 72%), m.p. 123-124° C.

[0038] Yellow couplers Y-1 and Y-2 can be prepared by the procedure described for Y-3.

[0039] The following couplers C-1, C-2 and C-3 were used for comparison:

Preparation of Photographic Elements

[0040] Dispersions of the couplers were prepared in the following manner. The quantities of each component are found in Table I. In one vessel, the coupler, stabilizer (2,2ʼ-methylenebis-(3-t-butyl-5-methylphenol) monoacetate), coupler solvent (dibutyl phthalate), and ethyl acetate were combined and warmed to dissolve. In a second vessel, the gelatin, Alkanol XC™ (E.I. DuPont Co.) and water were combined and warmed to about 40° C. The two mixtures were mixed together and passed three times through a Gaulin colloid mill. The ethyl acetate was removed by evaporation and water was added to restore the original weight after milling.

[0041] The photographic elements were prepared by coating the following layers on a resin-coated paper support:

DOC	Gelatin (1.40 g/m²) bis(vinylsulfonylmethyl) ether (0.14 g/m²)
OVERLAYER	Gelatin (1.33 g/m²) 2-(2H-benzotriazol-2-yl)-4,6-bis-(1,1-dimethylpropyl)phenol (0.73 g/m²) Tinuvin 326™ (Ciba-Geigy) (0.13 g/m²)
EMULSION LAYER	Gelatin (1.61 g/m²) Coupler dispersion from Table II (7.0 x 10⁻⁴ mole coupler/m²)Blue-sensitized AgCl emulsion (0.24 g Ag/m²)
UNDERLAYER	Gelatin (3.23 g/m²)
FILMBASE	Resin-coated paper support

Exposing and Processing of Photographic Elements

[0042] The photographic elements were given stepwise exposures to green light and processed as follows at 35° C:

Developer	45 sec
Bleach-Fix	45 sec
Wash (running water)	1 min 30 sec

[0043] The developer and bleach-fix were of the following compositions:

Developer
Water	700.00 ml
Triethanolamine	12.41 g
Anhydrous potassium carbonate	21.16 g
Potassium chloride	1.60 g
Potassium bromide	7.00 mg
Lithium sulfate	2.70 g
Lithium polystyrene sulfonate (30%)	0.30 g
N-{2-[(4-amino-3-methylphenyl)ethylamino]ethyl}-methanesulfonamide, sesquisulfate	5.00 g
N,N-Diethylhydroxylamine (85%)	5.40 g
1-Hydorxyethyl-1,1-diphosphonic acid (60%)	0.81 g
Blankophor REU™ (Mobay Corp.)	2.30 g
Water to make 1 liter, pH 10.4 ± 0.05 @ 26.7°C

Bleach-Fix
Water	700.00 ml
Solution of ammonium thiosulfate (56.4%) + ammonium sulfite (4%)	127.40 g
Sodium metabisulfite	10.00 g
Acetic acid (glacial)	10.20 9
Solution of ammonium ferric ethylenediaminetetraacetate (44%) + ethylenediaminetetraacetic acid (3.5%)	110.40 g
Water to make 1 liter, pH 6.7 @ 26.7°C

[0044] Yellow dyes were formed upon processing. The following photographic characteristics were determined: Dmax (maximum density to blue light); Dmin (minimum density to blue light); Contrast (slope of a line connecting the two points on the Density v. Log Exposure (D vs logE) curve at which logE is 0.3 less and 0.3 more, respectively, than the point at which the density is 1.0). These values for each example are tabulated in Table II.

Table II

Coupler	Dmax	Dmin	Contrast
Y-1	1.13	0.065	0.86
C-1	1.10	0.067	0.77
Y-2	2.23	0.085	2.54
C-2	1.84	0.093	2.08
Y-3	1.70	0.066	1.83
C-3	1.29	0.061	1.09

[0045] Additional coatings prepared and processed as described above were illuminated by simulated daylight at 50 klux for periods of 2 and 4 weeks. The blue densities were monitored and the time in weeks required for 30% density loss from an initial density of 1.0 (T30) was calculated. These data are found in Table III.

Table III

Coupler	T-30 (fade)	Printout (4 weeks)
Y-1	1.76	0
C-1	1.70	-1
Y-2	3.44	-1
C-2	2.39	-5
Y-3	2.39	0
C-3	2.12	0

[0046] As is evident from Tables II and III, the yellow couplers according to the present invention provide not only improved coupling efficiency (as expressed by Dmax and contrast), but, unexpectedly, also superior image dye stability and printout.

[0047] It is to be understood that the foregoing detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.

Claims

1. A photographic element comprising a support and a silver halide emulsion layer having associated therewith a yellow dye-forming coupler comprising (a) an acyl acetanilide in which said acyl group includes a multicyclic carbon center attached to the carbonyl moiety, and (b) an aryloxy coupling-off group at the coupling position of the acyl acetanilide, said coupling-off group having at least one substituent which is an ionizable group or a solubilizing group.

2. A photographic element as claimed in claim 1, wherein said yellow dye-forming coupler is represented by the formula

wherein

R⁰   denotes

R¹   denotes an ionizable or solubilizing group;

v   denotes an integer from 1 to 3;

X   denotes the atoms necessary to complete a phenyl or naphthyl ring system;

Y   denotes hydrogen, halogen, CN, CF₃, C(O)_nR², CR²R³C(O)_nR², CR²R³CONR²R³, COO(CH₂CH₂O)_pR², CONR²R³, CONR²(CH₂CH₂-O)_pR³, NO₂, NR²S(O)_nR³, NR²S(O)_nNR²R³, NR²COR³, NR²COCH(R²)(OR³), NR²CONR²R³, OR², O(CH2)_qR², O(CH₂CH₂O)_pR², O(CH₂CH₂O)_pCOOR², O(CH₂CH₂O)_pCONR²R³, S(O)_nR², S(O)_nNR²R³, or S(O)_nNR²(CH₂CH₂-O)_pR³;

R²,R³   independently denote hydrogen or unsubstituted or substituted alkyl, aryl or heterocyclyl, or together complete a heterocyclic ring with the nitrogen or oxygen atoms to which they are attached;

n   denotes 1 or 2;

p, q,   independently denote an integer from 1 to 3; and

r   denotes an integer from 1 to 4.

3. A photographic element as claimed in claim 2 , wherein R⁰ is an adamantyl group, a bicyclo[2,2,1]heptyl group, or a bicyclo[2,2,2]octyl group.

4. A photographic element as claimed in claim 2 or 3, wherein R¹ is a group selected from
   -OH -NH-C₂H₂-OH -N(C₂H₂-OH)₂ -COOH -NH-C₃H₆-COOH -N(C₂H₄-COOH)₂ -N(SO₂-C₂H₄-OH)₂ -NHSO₂-C₂H₄-OH -SO₂NH-C₂H₄-OH -SO₂N(C₂H₄OH)₂ -N(SO₂-C₂H₄-COOH)₂ -NHSO₂-C₂H₄-COOH

   wherein p = 1 or 2.

5. A photographic element as claimed in any of claims 1 to 4, wherein said yellow dye-forming coupler comprises a ballast group.

6. A photographic element as claimed in claim 2, wherein said coupling-off group is selected from:

7. A photographic element as claimed in claim 2, wherein said yellow coupler is selected from:

8. A yellow dye-forming coupler as defined in any of claims 1 to 7.

9. A process for developing an image in a photographic element comprising a support and a silver halide emulsion containing an imagewise distribution of developable silver halide grains, said process comprising the step of developing said element with a silver halide color developing agent in the presence of a yellow dye-forming coupler as claimed in claim 8.

10. A photographic silver halide emulsion containing a yellow dye-forming coupler as claimed in claim 8.