US3706562A

US3706562A - Photographic materials and processes for developing photographic compositions

Info

Publication number: US3706562A
Application number: US137614A
Authority: US
Inventors: Arthur H Herz; Donald M Burness; Edward J Seus
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1967-10-02
Filing date: 1971-04-26
Publication date: 1972-12-19
Anticipated expiration: 1989-12-19
Also published as: GB1247883A; BE721568A; FR1585284A

Abstract

PHOTOGRAPHIC COMPOSITIONS AND ELEMENTS COMPRISING A ZWITTERIONIC COMPOUND AND A CATIONIC AND/OR A NONIONIC DEVELOPMENT MODIFIER. IN ONE ASPECT, THIS INVENTION RELATES TO A PRCESS COMPRISING DEVELOPING A PHOTOGRAPHIC IMAGE IN THE PRESENCE OF A ZWITTERIONIC COMPOUND AND A CATIONIC OR A NON-IONIC DEVELOPMENT MODIFIER. IN ANOTHER ASPECT, THIS INVENTION RELATES TO A PHOTOGRAPHIC DEVELOPER COMPOSITION COMPRISING A PHOTOGRAPHIC DEVELOPING AGENT, A ZWITTERIONIC COMPOUND, AND A CATIONIC OR A NONIONIC DEVELOPMENT MODIFIER.

Description

United States Patent Ofice 3,706,562 Patented Dec. 19, 1972 3,706,562 PHOTOGRAPHIC MATERIALS AND PROCESSES FOR DEVELOPING PHOTOGRAPHIC COM- POSITIONS Arthur H. Herz, Donald M. Burness, and Edward J. Sens, $1165 6 Eastman Kodak Company, Rochester, NY.

4 No Drawing. Continuation of abandoned application Ser. No. 671,998, Oct. 2, 1967. This application Apr. 26, 1971, Ser. No. 137,614

Int. Cl. G03c 5/30 U.S. Cl. 96-665 22 Claims ABSTRACT OF THE DISCLOSURE Photographic compositions and elements comprising a zwitterionic compound and a cationic and/or a nonionic development modifier. In one aspect, this invention relates to a process comprising developing a photographic image in the presence of a zwitterionic compound and a cationic or a non-ionic development modifier. In another aspect, this invention relates to a photographic developer composition comprising a photographic developing agent, a zwitterionic compound, and a cationic or a nonionic development modifier.

This is a continuation of Ser. No. 671,998, filed Oct. 2, 1967, now abandoned.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to novel photographic materials and their preparation and to novel photographic processes. In one aspect, this invention relates to photographic emulsions and elements which have improved speed to fog ratios. In another aspect, this invention relates to photographic emulsions, elements and processes in which zwitterionic compounds are used in combination with cationic and non-ionic development modifiers and which yield synergistic speed gains in development.

Description of the prior art It is known to use certain zwitterionic compounds as wetting agents to produce photographic emulsions having improved wetting characteristics. In U.S. Pat. 2,197,809 of McQueen, granted Apr. 23, 1940, various cation-active surface active compounds including certain betaines are incorporated in photographic emulsions to give more thorough wetting of the emulsion during development. Zwitterionic compounds have also been used as coating aids. In U.S. Pat. 3,133,816 of Ben-Ezra, granted May 19, 1964, certain betaines are used in combination with certain amino acids as a coating solution for photographic materials. Moreover, it is known that many surface active organic compounds will increase the development speed of silver halide emulsions without changing their spectral sensitivity. However, many of these surfactants strongly increase development fog, and tend to produce high fog on storage.

Thus it is an object of this invention to provide new photographic compositions.

It is another object of the invention to provide a combination of compounds which yield a good speed gain in development and result in little or no increase of incubation and development fog when used in a photographic emulsion.

Another object of this invention is to provide novel photographic emulsions and elements which comprise a zwitterionic compound.

A further object of this invention is to provide photographic emulsions and elements which have improved speed to fog ratios.

Still another object of this invention is to provide means for developing photographic emulsions or elements which produce improved speed or contrast.

A further object of this invention is to provide novel photographic developer compositions which can be used to give improved speed in photographic emulsions.

Other objects will be apparent from the specification and claims.

SUMMARY OF THE INVENTION It has been found that when photographic elements are developed in the presence of a zwitterionic compound and a cationic or non-ionic development modifier, an increase in speed is obtained with little or no increase in incubation or development fog. The zwitterionic compounds and the development modifiers can be contained in a photographic emulsion or element, as well as in a processing solution or element. The zwitterionic compounds and the development modifiers can be contained in the same or in different layers in a photographic element. When the development modifier is itself a development accelerator, it has been found that using the development modifier in combination with a zwitterionic compound yields synergistic speed gains in development. The zwitterionic compounds and the cationic or non-ionic development modifiers can be contained in photographic developer compositions which also comprise photographic developing agents.

The zwitterionic compounds employed in the practice of this invention are compounds which contain both a negatively and a positively charged atom in each molecule. Zwitterions are also sometimes referred to as inner salts. These zwitterions can be represented generically as compounds having the formula C B-A wherein C represents an organic cationic residue and BA represents the covalently bound anionic part of the molecule. The zwitterions can be used in the form of adducts with protonic acids. Betaines, which are zwitterions having a positively charged nitrogen atom, and thetins, which are zwitterions having a positively charged sulfur atom, are among the preferred types of zwitterions used in the invention. Pyridinium betaines, in which the positively charged nitrogen atom is part of a pyridine ring, are among the heterocyclic betaines which are generally useful in our invention. Two preferred classes of zwitterions which are useful in the practice of this invention are represented by the following Formulas, I and II:

A can be a nitrogen or a phosphorus atom; R R and R can be unsubstituted or substituted alkyl or aryl groups, such as methyl, ethyl, propyl, 2-methylpropyl, decyl, hexadecyl, hydroxyethyl, benzyl, and the like, and phenyl, naphthyl, tolyl, and the like; and two or more of the groups R R or R can be taken together to form a heterocyclic ring having one or more hetero atoms; R, can be an unsubstituted or substituted alkyl chain containing one or more carbon atoms, such as a methyl, ethyl, pentyl, and decyl chain and the like, and B is an anionic acid residue;

wherein D is a sulfur atom; R and R can be unsubstituted or substituted alkyl or aryl groups, such as methyl, ethyl, propyl, 2-methylpropyl, decyl, hexadecyl, hydroxyethyl, benzyl, and the like, and phenyl, naphthyl, tolyl, and the like; and 'R and R can be taken together to form a heterocyclic ring having one or more hetero atoms; R; can be an unsubstituted or substituted alkyl chain containing two or more carbon atoms such as an ethyl, pentyl, and decyl chain and the like; and E is an anionic acidic residue.

Typical anionic acidic residues represented by B and E in Formulas I and II include carboxylate, phosphate, sulfate, sulfonate groups, and the like. The zwitterionic compounds of this invention preferably contain from about 10 to 30 carbon atoms and have a molecular weight of greater than about 150. Typical zwitterions which are useful in this invention include:

(l-carboxyethyl)methyldodecylsulfonium hydroxide,

inner salt,

(Z-carboxyethyl)methyldodecylsulfonium hydroxide,

inner salt,

(3-sulfopropyl)methyldodecylsulfonium hydroxide,

inner salt,

(2-carboxyethyl)methylhexadecylsulfonium hydroxide,

inner salt,

(l-carboxyethyl)methylhexadecylsulfonium hyroxide,

inner salt,

(2-carboxy-i-butyl)methyldodecylsulfonium hydroxide,

inner salt,

(10-carboxydecyl)tetrahydrothiophenium hydroxide,

inner salt,

( IO-carboxydecyl)dimethyldodecylammonium hydroxide,

inner salt,

(Z-carboxy-i-butyl)dimethyldodecylammonium hydroxide, inner salt,

(2-carboxyethyl) dimethyldodecylammonium hydroxide,

inner salt,

(Z-carboxymethyl)dimethydodecylammonium hydroxide,

inner salt,

(3-sulfopropyl)dimethyldodecylammonium hydroxide,

inner salt,

(4-sulfobutyl) dimethyldodecylammonium hydroxide,

inner salt,

(3-sulfobutyl)dimethyldodecylammonium hydroxide,

inner salt,

(3-sulfopropyl)diethyldodecylammonium hydroxide,

inner salt,

(4-sulfobutyl)diethyldodecylammonium hydroxide,

inner salt,

(Z-carboxyethyl)dimethyloctadecylammonium hydroxide,

inner salt,

(carboxymethyl) dimethyloctadecylammonium hydroxide,

inner salt,

(3-sulfopropyl)dimethyloctadecylammonium hydroxide,

inner salt,

l-(l0-carboxydecyl)pyridinium hydroxide, inner salt,

1-(10-sulfatodecyl)pyridinium hydroxide, inner salt,

B-carbethoxy- 1-( 10-carboxydecyl)pyridinium hydroxide,

inner salt,

1-(l-carboxytridecyl)pyridinium hydroxide, inner salt,

1-( l-carboxyundecyl)pyridinium hydroxide, inner salt, 1-( 17-carboxy-6-oxo-7-azaheptadecyl pyridinium hydroxide, inner salt, 3-carboxy-l-dodecylpyridinium hydroxide, inner salt, and the like.

The development modifiers which are useful in the practice of this invention are cationic and non-ionic compounds which affect photographic characteristics of a photographic emulsion. These development modifiers are sometimes compounds which themselves act as development accelerators. A wide variety of compounds have been found to be particularly useful as development modifiers in this invention, including cationic compounds such as,

for example, quaternary ammonium compounds such as those disclosed in U.S. Pat. 2,271,623 of Carroll, granted Feb. 3, 1942, quaternary phosphonium compounds such as those disclosed in U.S. Pat. 2,271,622 of Carroll et al., granted Feb. 3, 1942, and ternary sulfonium compounds such as those disclosed in U.S. Pat. 2,275,727 of Carroll et al., granted Mar. 10, 1942, and neutral compounds such as, for example, polyalkylene glycols such as polyethylene glycol, polypropylene glycol and the like, which preferably have a molecular weight of more than about 400, organic thioethers such as those disclosed in U.S. Pat. 3,046,134 of Dann et al., granted July 24, 1962, U.S. Pat. 3,038,805 of Dann et al., granted June 12, 1962, and U.S. Pat. 3,021,215 of Williams, granted Feb. 13, 1962, and their derivatives. Among the preferred development modifiers of this invention are bispyridinium salts such as, for example, 7, 18-diaza-6, l9-dioxotetracosane- 1,24-bis (pyridinium perchlorate), 12,15-diaza-11,16-dioxohexacosane-1,26- bis (pyridinium perchlorate), tetradecamethylene-bis(pyridinium perchlorate), and the like, hydrazinium salts such as, for example, N-decyldimethylhydrazinium perchlorate, and the like and ethers of polyethylene oxide such as, for example, the oleyl ether of polyethylene oxide, and the like.

In a preferred embodimnt of this invention, the photographic elements contain silver halide emulsions. The silver halide can be silver chloride, silver bromide, silver iodide, or mixed silver halides such as silver chlorobromide, silver chloroiodide, silver bromoiodide, silver chlorobromoiodide, and the like. Particularly useful are high contrast photographic emulsions of the type described in U.S. Pat. 2,756,148 of MacWilliam, granted July 24, 1956. The silver halides preferably used can be those which form latent images predominantly on the surface of the silver halide grains or those which form latent images inside the silver halide crystals such as described in U.S. Pat. 2,592,250 of Davey and Knott, issued Apr. 8, 1952. For one preferred emulsion, the silver halide of the emulsions comprises more than about mole percent silver chloride. For another preferred emulsion, the silver halide can be advantageously gold or sulfur sensitized. The silver halide, the zwitterionic compounds and the developer modifier can be contained in the same layer or in different layers of a photographic element. The preferred concentration of the zwitterions in the silver halide emulsions and elements of the invention is from about 0.50 to 50 grams per mole of silver in the silver halide layer, and is generally from about 1.0 to 30 grams per mole of silver in the silver halide layer. The preferred concentration of the development modifiers in the silver halide emulsions and elements of the invention is from about 5 milligrams to 10 grams per mole of silver in the silver halide layer and is generally from about 0.1 to 5 grams per mole of silver in the silver halide layer.

Any customary photographic developing agent can be used in the developer compositions of this invention. Typical developers include polyhydroxybenzenes such as hydroquinone, pyrogallol, catechol, and the like, ascorbic acids, 3-pyrazolidones, p-aminophenols, phenylenediamines, and the like or combinations thereof. The developer compositions of the invention comprise a photographic developing agent and generally from about 1.0 to 50 grams per liter of the developer composition of a Zwitterionic compound and from about 50 mg. to 25 grams per liter of the developer composition of a cationic or non-ionic developer modifier. Furthermore, the zwitterionic compound can be contained in an emulsion while the development modifier is in a processing solution or element, and similarly the development modifier can be contained in an emulsion while the zwitterion is in a processing solution or element.

The new developer compositions according to this invention can be provided in kit form as long as the essential ingredients are present, namely the developer, the zwitterionic compound and the developer modifier. The kit may comprise diluted, concentrated or powdered forms of said ingredients individually packaged or combined together, which can be used to form an aqueous bath of said ingredients. The compounds are generally provided individually in a form which can be added to Water just prior to using the developer bath.

The silver halide emulsion of a photographic element useful in this invention can contain conventional addenda such as gelatin plasticizers, coating aids, antifoggants such as the azaindines and hardeners such as aldehyde hardeners, e.g., formaldehyde, mucochloric acid, glutaraldehyde bis(sodium bisulfite), maleic dialdehyde, aziridines, dioxane derivatives and oxypolysaccharides. Sensitizing dyes useful in sensitizing such emulsions are described, for example, in U.S. Pats. 2,526,632 of Brooker and White, issued Oct. 24, 1950, and 2,503,776 of Sprague, issued Apr. 11, 1950. Spectral sensitizers which can be used are the cyanines, merocyanines, complex (trinuclear) cyanines, complex (trinuclear) merocyanines, styryls, and hemicyanines.

The silver halide emulsion layer of a photographic elements which is useful in the instant invention can contain any of the hydrophilic, water permeable binding materials suitable for this purpose. Suitable materials include gelatin, colloidal albumin, polyvinyl compounds, cellulose derivatives, acrylamide polymers, etc. Mixtures of these binding agents can also be used. The binding agents for the emulsion layer of the photographic element can also contain dispersed polymerized vinyl compounds. Such compounds are disclosed, for example, in U.S. Pat. 3,142,568 of Nottorf issued July 28, 1964; 3,193,386 of White issued July 6, 1965; 3,062,674 of Houck et al. issued Nov. 6, 1962 and 3,220,844 of Houck et al. issued Nov. 30, 1965; and include the water insoluble polymers of alkyl acrylates and methacrylates, acrylic acid, sulfoalkyl acrylates or methacrylates and the like.

The silver halide emulsion of a photographic element which is useful in the instant invention can be coated on a wide variety of supports. Typical supports are cellulose nitrate film, cellulose ester film, polyvinyl acetal film, polystyrene film, polyester film supports such as poly(ethylene terephthalate) and related films or resinous materials as Well as glass, paper, metal and the like. Supports such as paper which are coated with a-olefin polymers, particularly polymers of u-olefins containing two or more carbon atoms, as exemplified by polyethylene, polypropylene, ethylene-butene copolymers and the like, can also be employed.

The sensitometric characteristics of the photographic emuslions useful in the instant invention can be further enhanced by including in the emulsions a variety of hydrophilic colloids such as carboxymethyl protein of the type described in U.S. Pat. 3,011,890 of Gates, Jr., et al. issued Dec. 5, 1961, and polysaccharides of the type described in Canadian Pat. 635,206 of Koller et al. issued Jan. 23, 1962.

The photographic elements prepared according to the instant invention can be used in'various kinds of photographic systems. In addition to being useful in X-ray and other nonoptically sensitized systems, they can also be used in orthochromatic, panchromatic and infrared sensitive systems. The sensitizing addenda can be added to photographic systems before or after any sensitizing dyes which are used.

Silver halide emulsions useful in the instant invention can be sensitized using any of the well known techniques in emulsion making, for example, by digesting with gold compounds and/or with naturally active gelatin or various sulfur, selenium, tellurium compounds. The emulsions can also be sensitized with salts of noble metals of Group VIII of the Periodic Table which have an atomic weight greater than 100.

The invention can be further illustrated by the following examples of preferred embodiments thereof, although it will be understood that the examples are included merely for purposes of illustration and are not intended to limit the scope of the invention unless otherwise indicated.

EXAMPLE 1 Gold and sulfur sensitized high speed silver brornoiodide emulsions are prepared and to each are added the p-toluenesulfonic acid salt of (1-carboxyethyl)methyldodecylsulfonium hydroxide, inner salt and a development modifier. The emulsions are coated on a film support, to yield 0.355 g. of Ag and 0.84 g. of gelatin per sq. ft., dried, exposed and developed at 20 C. in an elon-hydroquinone developer (Kodak D-19) for 4 minutes. Where necessary, the compound is neutralized before addition to the emulsion and in all examples the pH of the emulsions is kept constant. The following development modifiers were employed:

(1) 7,18-diaza-6,19-dioxotetracosane 1,24-bis(pyridinum perchlorate) (II) polyethylene oxide, oleyl ether The tested emulsions have the following speed, expressed as a reciprocal of exposure on an Eastman I-B sensitometer (relative to the value of assigned to a control) and measured at 0.3 density units above fog:

Zwitterion conc. Development Cone. (g./ Relative (g./mole Ag) modifier mole Ag) speed Fog After one week incubation at 49 C. and 50% relative humidity, the fog is not appreciably increased where the zwitterion-development modifier combination is used. When the thetins such as (2-carboxyethyl)methyldodecylsulfonium hydroxide, inner salt, (3-sulfopropyl)methyldodecylsulfonium hydroxide, inner salt, and (Z-carboxyethyl)methylhexadecylsulfonium hydroxide, inner salt, are tested in the same manner, similar results are obtained.

Thus, the emulsions which contain both the zwitterionic compound and the development modifier show unexpected synergistic speed gains on development and improved speed to fog ratios when compared to emulsions containing the zwitterion alone or the development modifier alone.

EXAMPLE 2 Following the procedure of Example 1, the following betaines:

(A) (Z-carboxyethyl)dimethyloctadecylammonium hydroxide, inner salt,

(B) (carboxymethyl)dimethyloctadecylammonium hydroxide, inner salt,

(C) (3-sulfopropyl)dimethyloctadecylammonium hydroxide, iner salt,

(D) (4-sulfobutyl)diethyldodecylammonium hydroxide,

inner salt,

(E) (4-sulfobutyl)dimethyldodecylammonium hydroxide, inner salt,

(F) 1-(10-sulfatodecyl)pyridinium hydroxide, inner salt,

and the following development modifiers:

(II) polyethylene oxide, oleyl ether,

(III) Carbowax 1540,

(IV) 12,15-diaza-11,16-dioxohexacosane 1,26-bis(pyr idinium perchlorate),

(V) tetradecamethylene bis(pyridinium perchlorate),

(VI) N-decyldimethylhydrazinium perchlorate,

were tested, giving the following results:

Cone. Cone. zwitterionic (g./mo1e Development (gJmole Relative compound Ag) modifier Ag) speed Fog After oneweek incubation at 49 C. and 50% relative humidity, the fog is not appreciably increased over a control. When the betaines such as (IO-carboxydecyl) dimethyldodecylammonium hydroxide, inner salt, (2-carboxyethyl)dimethyldodecylammonium hydroxide, inner salt, (Z-carboxymethyl)dimethyldodecylammonium hydroxide, inner salt, and (3-sulfopropyl)dimethyldodecylammonium hydroxide, inner salt, are tested in the same manner, similar results are obtained.

Similar results are also obtained when the zwitterionic compounds and development modifiers are used in the developing composition.

As in Example 1, the emulsions which contain both the zwitterionic compound and the development modifier show synergistic speed gains on development improved speed to fog ratios.

EXAMPLE 3 Emulsions are prepared and coated by the procedure of Example 1, using the p-toluenesulfonic acid salt of (l-carboxyethyl)methyldodecylsulfonium hydroxide as the zwitterion and development modifier (I) (specified in Example 1). These emulsions are exposed and developed in a paraformaldehyde developer (Kodak D-85), and gave the following results:

Development zwitterion cone. modifier conc. Relative (g./mole Ag) (gJmole Ag) speed Fog Contrast Thus, when developed with a high contrast developer used in lith processes, emulsions which contain both the zwitterion and the development modifier show synergistic speed gains on development.

The 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. A photographic element comprising (1) a support, (2) at least one layer thereon comprising a photosensitive silver halide composition, (3) at least one layer thereon containing at least 1 gram of a zwitterionic organic compound per mole of said silver halide, said zwitterionic compound having the formula:

wherein: A is a nitrogen or a phorphorus atom; R R and R are unsubstituted alkyl, aralkyl, or substituted or unsubstituted aryl groups; and two or more of the groups R R and R can be taken together with A to form a heterocyclic ring; R; is an unsubstituted or substituted alkylene chain containing one or more carbon atoms, and B is an anionic acid residue; or the formula:

wherein: D is a sulfur atom; R and R are unsubstituted or substituted alkyl, aralkyl or aryl groups; and R and R can be taken together with D to form a heterocyclic ring; R; is an unsubstituted or substituted alkylene chain containing two or more carbon atoms; and E is an anionic acidic residue; and (4) at least one layer containing a nonionic organic development modifier; a cationic compound which contains an ammonium, phosphonium or sulfonium group; or mixtures thereof.

2. A photographic element according to claim 1 wherein said zwitterionic compound, and said nonionic organic development modifier, cationic compound or mixtures thereof are present together with a gelatin binder in said layer containing said silver halide composition.

3. A photographic element according to claim 1 comprising at least one layer wherein said cationic compound is a bispyridinium salt.

4. A photographic element according to claim 1 comprising at least one layer wherein said nonionic develop ment modifier is a polyalkylene glycol.

5. A photographic element according to claim 1 comprising at least one layer wherein said nonionic development modifier is an organic thioether compound.

6. A photographic element according to claim 1 comprising at least one layer wherein said zwitterionic compound is a betaine.

7. A photographic element according to claim 1 comprising at least one layer wherein said zwitterionic compound is a pyridinium betaine.

8. A photographic element according to claim 1 comprising at least one layer wherein said zwitterionic compound is a thetin.

9. A photographic element according to claim 1 which comprises from about 1 gram to about 30 grams of said zwitterionic compound per mole of silver in said photographic element.

10. A photographic element according to claim 1 which comprises from about 0.1 gram to about 5 grams of said nonionic organic development modifier, cationic compound or mixtures thereof per mole of silver in said photographic element.

11. A photographic element according to claim 1 wherein said silver halide composition comprises a sulfur and gold-sensitized silver halide emulsion wherein the halide in said silver halide is more than 50 mole percent chloride.

12. The emulsion of claim 1 wherein said zwitterionic compound is (l-carboxyethyl)methyldodecylsulfonium hydroxide, inner salt, and said nonionic development modifier is the oleyl ether of polyethylene oxide.

13. The emulsion of claim 1 wherein said zwitterionic compound is (4-sulfobutyl)dimethyldodecylammonium hydroxide, inner salt, and said cationic compound is tetradecamethylene bis(pyridinium perchlorate).

14. A photographic element comprising 1) a support, (2) at least one layer comprising (a) a photosensitive silver halide emulsion, (b) a zwitterionic compound and (c) an organic cationic compound containing an ammonium, phosphonium or sulfonium group; a nonionic organic development modifier; or mixtures thereof; said zwitterionic compound having the formula:

1 wherein: A is a nitrogen or a phosphorus atom; R R

and R are unsubstituted alkyl, aralkyl, or substituted or unsubstituted aryl groups; and two or more of the groups R R and R can be taken together with A to form a heterocyclic ring; R; is an unsubstituted or substituted alkylene chain containing one or more carbon atoms, and B is an anionic acid residue; or the formula:

wherein: D is a sulfur atom; R and R are unsubstituted or substituted alkyl, aralkyl or aryl groups; and R and R can be taken together with D to form a heterocyclic ring; R is an unsubstituted or substituted alkylene chain containing two or more carbon atoms; and E is an anionic acidic residue.

15. The photograph element of claim 14 wherein said nonionic development modifier is a polyalkylene glycol with a molecular weight of at least about 400.

16. The photographic element of claim 14 wherein said cationic compound is a bis-pyridinium salt.

17. A photographic element comprising (1) a support, (2) at least one layer containing a silver halide emulsion, (3) at least one layer containing a zwitterionic organic compound which is a thetin or a betaine and (4) at least one layer containing a polyalkylene glycol or an organic thioether compound.

18. In a process for producing an image in a photographic element which comprises at least one layer which contains a photosensitive silver halide composition, the improvement comprising developing the image with a silver halide developer in the presence of (1) a zwitterionic organic compound, said zwitterionic compound having the formula:

wherein: A is a nitrogen or a phosphorus atom; R R and R are unsubstituted alkyl, aralkyl, or substituted or unsubstituted aryl groups; and two or more of the groups R R and R can be taken together with A to form a heterocyclic ring; R; is an unsubstituted or substituted alkylene chain containing one or more carbon atoms, and B is an anionic acid residue; or the formula:

wherein: D is a sulfur atom; R and R are unsubstituted or substituted alkyl, aralkyl or aryl groups; and R and R can be taken together with D to form a heterocyclic ring; R, is an unsubstituted or substituted alkylene chain containing two or more carbon atoms; and E is an anionic acid residue; and (2) a cationic compound which contains an ammonium, sulfonium or phosphonium group; a nonionic organic development modifier; or mixtures thereof.

19. The process of claim 18 wherein said zwitterionic compound is a thetin or a betaine.

20. The process of claim 18 wherein said cationic compound is a bis-pyridinium salt and said nonionic organic development modifier is a polyalkylene glycol or an organic thioether.

21. The composition according to claim 18 wherein said silver halide developer is a paraformaldehyde compound.

22. A kit comprising the ingredients for providing the silver halide developer, said zwitterionic compound, said nonionic organic development modifier, or said mixtures thereof, for the developer composition of claim 18.

References Cited UNITED STATES PATENTS 3,113,026 12/1963 Sprung 96107 FOREIGN PATENTS 1,019,222 8/1962 England. 1,066,007 7/1965 England.

OTHER REFERENCES Mason: Photographic Processing Chemistry, Focal Press, pp. 41-45.

NORMAN G. TORCHIN, Primary Examiner J. L. GOODROW, Assistant Examiner US. Cl. X.R. 96-66, 76,

PO-wso UNTEED STATES MTENT @FFECE v CER'EFEFEEATE GE QQEQ'HQN Patent No. 5,706,562 Dated December 19, 1972 Inventor) Arthur H. Herz, Donald M. Burness, dward J. Seus It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

001. 7, line 70, structure "R2 1?? R R B should read R Col. 9, line 7, "photograph" should read ---photogr*aphio-- Signed and sealed this 10th day of July 1973'.

(SEAL) Attest:

EDWARD M.F LETCHER,JR. e Tegtmeyer Attesting Officer Acting Commissioner of Patents