US2899306A

US2899306A - Yh hci

Info

Publication number: US2899306A
Authority: US
Priority date: 1957-01-24
Publication date: 1959-08-11
Anticipated expiration: 1976-08-11
Also published as: GB886722A; BE564174A

Description

Unite tcs ANTIFOGGANTS FOR REVERSAL COLOR DEVELOPMENT Catherine Marilyn Spath, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey N Drawing. Application January 24, 1957 Serial No. 635,944

Claims. (Cl. 96-56) the blue-sensitive and green-sensitive layers is a filter layer for absorbing blue radiation which may be transmitted through the blue-sensitive layer. The multi-layer coating can also have other interlayers for specialized purposes. Such multi-layer materials have been previously described in the prior art, such as Mannes et al. US. Patent 2,252,718, issued August 19, 1941.

Color materials of the type employed in the instant invention are those intended primarily for reversal processes, wherein the exposed material is given a conventional black-and-white development, followed by a reversal exposure, or exposures, and color development.

The color materials used in my invention comprise emulsions which can contain color-forming materials or couplers, or these color couplers can be used instead in the color developers.

It is, therefore, an object of my invention to provide improved developers for reversal color photography. Another object is to provide a method of inhibiting color fog and increasing the maximum color density. Other objects will become apparent from a consideration of the following examples and description.

During the black-and-white development of multi-layer color materials, fog centers are introduced into the unexposed regions, and upon reversal exposure and subsequent color development, these unexposed areas have deposited therein coupled color-forming materials, resulting in severe loss of color quality. For example, in processing color materials of the Kodachrome type, color developer containing a cyan coupler results not only in development of the red-sensitive layer, but also in development of cyan fog in the blueand green-sensitive layers. This fog is particularly severe in emulsions which contain conventional chemical sensitizers, such as gold sensitizers, sulfur sensitizers, or polyethyleneglycol type chemical sensitizers.

I have now found that such undesirable fog can be eliminated or materially reduced by adding an organic compound containing a formamidinothiomethyl substituent to one or more of the color developers. These formamidinothiomethyl compounds decrease color fog in the unexposed areas with no substantial loss of color density in the exposed areas. These compounds can be conveniently added to the color developer, which may or may not contain a color coupler or color-forming compound, depending upon the particular color material being atent O 2,899,306 Patented Aug. 11, 1959 processed. It is to be understood that my invention comprises the use of color materials which may contain the color couplers or color-forming compounds either in the emulsions or in the color developing solutions. Particular benefits have been obtained with color materials wherein the color couplers or color-forming materials are present in the color developing solutions.

It is known that a colored image can be formed by adding to certain color developing solutions, or by incorporating in the silver halide emulsion, a compound which couples during development with the oxidation product of the developing agent, thus forming a colored compound which is deposited adjacent to the silver grains of the silver image during such development. Such compound which is employed in conjunction with the developing agent for the silver and which couples with the oxidation product of the developing agent during development is referred to as a color-forming compound or coupler. Such compounds usually belong to one of three widely known types, i.e., pyrazolone couplers, phenol couplers, or open-chain ketomethylene couplers. These couplers produce, respectively, magenta, cyan and yellow images.

The formamidinothiomethyl compounds useful in practicing my invention include compounds represented by the following general formula:

v such as dimethylamino, diethylamino, etc., monoarylamino, such as phenylamino, tolylamino, etc., diarylamino, such as diphenylamino, ditolylamino, etc., heterocyclylamino, such as Z-thiazylamino, triazylarnino, etc), and R represents a carbalkoxyl group (e.g., carbomethoxy, carb-ethoxyl, carbobutoxyl, etc., especially a carbalkoxyl group containing from 2 to 5 carbon atoms), an alkyl group (e.g., ethyl, n-propyl, n-butyl, p-sulfoethyl, etc., especially an alkyl group containing from 1 to 4 carbon atoms), a heterocyclyl group (e.g., tetrazaindenyl, pyridyl, etc.), or an amido group (e.g., amido thiazylamido phenylamido 2-formamidinothiomethyl-4-hydroxy-6-methy1-1,3,3a,7-

tetrazaindene Bis 2-formamidinothiomethyl-fi-methyl-l,3,3a,7- tetrazainden4-yl) sulfide HO3SCH2OH1S -i1=NH 2S-thlouroniumethanesulfonate "\N) E-S-CH,C 0 Cam S-carbethoxymethy1-1-pheny1-3- (4H-1,2,4-triazol-3-yl) isothlourea 0 NET-H01 i S-Z- thiazylamidomethylthiouronium chloride 0 NH-HCI H2NgCHg-S CNH2 S-amidomethyltlfiouronium chloride (0) NH-HBr C4H9S-CNH2 S-n-butylthionronium bromide The above formamidinothiomethyl compounds can be prepared according to methods previously described in the art. See, for example, Knott et al. U.S. Patent 2,461,987, issued February 15, 1949, and Tinker et a1. U.S. application Serial No. 515,785, filed June 15, .1955 (now U.S. Patent 2,835,581, issued May 20, 1958). Further examples describing the preparation of. these compounds are given below.

The formamidinothiomethyl compounds employed in the color developers of my invention can be utilized in various concentrations depending upon the particular emulsions employed, the concentration of silver halides in the emulsions, and the concentration of the developing agents in the developers. In general, not less than about mg. per liter of developer of formamidinothiomethyl compound should be employed. The most advantageous concentration can be determined by developing a series of test strips of silver halide emulsions wherein the concentration of formamidinothiomethyl compound is varied, as well as the concentration of the developing agent. The usual addenda can be employed in the developers, such as strongly alkaline agents, sodium carbonate, potassium carbonate, sodium hydroxide, etc., restraining agents, such as potassium bromide, stain preventives, such as alkali metal sulfites, etc.

My invention is primarilydirected to the development of the ordinarily employed gelatino-silver-halide developing-out emulsions, e.g., gelatino-silver-chloride,v -chlorobromide, -chloroiodide, -chlorobrorniodide, -bromide and -bromiodide developing-out emulsions. Whilethe results in the following examples were obtained using gelatinosilver-bromiodide emulsions, excellent results can alsobe obtained using other silverhalide emulsions. These emulsions can be coated in the usual manner on any suitable support, e.g., glass, cellulose nitrate film, cellulose acetate film, polyvinyl acetal resin film, paper or metal.

Photographic silver halide emulsions useful in my invention can also contain such addendaas chemical sen- 75 sitizers, e.g., sulfur sensitizers (e.g., allyl thiocarbamide, 'thiourea, allyl isothiocyanate, cystine, etc), various gold processes. Couplers or color-forming compounds which are soluble in the strongly alkaline developing solutions are well known to those skilled in the art. Typical couplers include the following:

COUPLERS FOR USE IN COLOR DEVELOPERS Cyan couplers:

1. S-benzenesulfonamino-l-naphthol 2. 2,4-dichloro-5-benzenesulfamino-l-naphthol 3. 2,4-dichloro-5-(p-toluenesulfamino)-1 naphthol 4. 5 (1,2,3,4 tetrahydronaphthalene 6-sulf0namino) -1-naphthol 5. 2,4-dich1oro 5 (4-bromodiphenyl 4 sulfonamino)-l-naphthol 6. o-(B-Naphthalenesulfonamino)-phenol 7. 5 (m nitrobenezenesulfonamino) l-naphthol 8. 5 (quinoline 5 sulfonamino) 1 naphthol (U.S. 2,362,598) 9. 2-acetylarnino-5-methylpheno1 10. 2 benzoylamino-3,5 dimethylphenol 11. 2 a-(p-tert. amylphenoxy)-n-butyrylamino-5- methylphenol 12. 2 a (p-tert. amylphenoxy)-n-butyrylamino4- chloro-S-methylphenol 13. 2 (p'-tert. amylphenoxy p-benzoyl)amino-4- chloro-S-methylphenol 14. 2 (4"-tert. amyl-3' phenoxybenzoylamino)- 3,5-dimethyl-1-phenol 15. 2 phenylacetylamino-4-chloro S-methylphenol 16. 2 L benzoylamino 4 chloro S-methylphenol 17. 2 anilinoacetylamino-4-chloro S-methylphenol 18. 2-{4'[oz-(4" tert. amylphenoxy) n-butyrylamino] benzoylamino}'4 chloro-S-methylphenol 19. 2 {4-[3"-(4"-tert. amylphenoxy) benzoylamino] benzoylamino}-4-chloro-5-methylphenol 20. 2-p-nitrobenzoylamino 4 chloro S-methylphenol 21. 2 m-aminobenzoyl 4-chloro-5-methylphenol 22. 2 acetamino-4-chloro-5-methylphenol 23. 2 (4'-sec. amylbenzamino)-4-chloro-5-methylphenol 24. 2-(4'- n amyloxybenzamino)-4-chloro-5-methylphenol Magenta couplers:

25. 1 phenyl 3-acetylarnino-5-pyrazolone 26. l phenyl 3 propionylamino-5-pyrazolone 27. 1 phenyl 3-dichloroacetylamino-S-pyrazolone 28. 1 phenyl 3-benzoylamino-S-pyrazolone 29. 1 phenyl 3-(m-aminobenzoyl) amino 5- pyrazolone hydrochloride 30. 1 phenyl 3 (diamylbenzoyl)amino 5 pyrazclone 31. 1 phenyl-3-phenylcarbamylamino-5-pyrazolone 32. 1 phenyl 3-phenoxyacetylamino-5-pyrazolone 33. 1 phenyl 3 p-aminobenzoylamino-5pyrazolone 34. 1 phenyl r 3-(o-carboxybenzoyl)amino-S-pyrazolone 35. 1 phenyl 3-palmitylamino-5-pyrazolone 36. 1 -phenyl-3-(p-sec. amylbenzenesulfonylamino)- S-pyrazolone 37. 1 phenyl 3-[p-(p'-sec. amylbenzoyl)amin0- benzoylaminol -5-pyrazolone 38. 1-m-tolyl-3-[m -(B-pheny1propiony1)aminobenzoylamino] -5-pyrazolone 39. 1 m tolyl 3-(2,4-di-tert. butyl-m-tolyloxyacetylamino)-5-pyrazolone 40. 1 [p-(p-tert. butylphenoxy)phenyl] -3-[p-(benzoylamino) -benzoylamino] -5-pyrazolone 41. l-(p-tert. butylphenoxyphenyl) 3 (p-m-amyloxyb enzoylamino) -5 -pyrazolone 42. 1-[p-(p'-tert. butylphenoxy)phenyl] 3 (3,5-dimethoxybenzoyDamino-S-pyrazolone 43. 1-[p-(p'-tert. butylphenoxy)phenyl]-3 [m-(ptoluene-sulfonylamino)benzoylamino] -5 pyrazolone 44. 1 [p-(3,5 dimethylphenoxy)phenyl]-3-(4-namyloxy-3 methylb enzoylamino) -5 -pyrazolone 45. 3-(p -'nitrophenoxyacetylamino) 1-(2',4',6'-trichlorophenyl) -5-pyrazolone Yellow couplers:

46. p-(w-Benzoylacetamino)benzenesulfonamide 47. p (w Benzoylacetamino)benzenesulfon N- methylamide 48. p-(w-Benzoylacetamino)benzenesulfonanilide 49. 4-benzenesulfonamino-w-benzoylacetanilide 50. 4 (p-toluenesulfonamino)-w-benzoylacetanilide 51. 4 (p-laurylbenzenesulfonamino) -w-benzoylacetanilide 52. 1,4-di [p (benzoylacetamino)benzenesulfonaminolbenzene 53. N,N' di (p-benzoylacetaminophenyl)benzene- 1,3-disulfonamide 54. N (p benzoylacetaminophenyl) -4-[p-(benzoylacetamino) benzenesulfonamido1benzenesulfonamide 55. N -benzoylacetyl N-(2-benzothiazo1yl)sulfanilamide 56. p Acetoacetaminobenzenesulfon-fl-naphthalide 5 7.' p Furoylacetaminobenzenesulfon-N-cyclohexylamide 58. p (4 ethoxybenzoylacetamino)benzenesulfonamide 59. Terephthaloyl bis[ (p-N-amylsulfonamido) acetanilide] 60. p (Quinoline 8 sulfonarnino) -w-benzoylacetanilide 61. p Acetoacetamino-o-methylbenzenesulfon N- anilide 62. N,N' di (p benzoylacetaminophenol)naphthalene-1,5-disulfonamide 63. p-(Benzenesulfonamino)benzoylacetone 64. N-benzoylaceto-o-anisidine Typical couplers that are primarily useful in the photographic silver halide emulsion layers of my invention comprise the following:

Coupler:

65. 1 hydroxy-2-[6-(2,4'-di-tert.amylphenoxy) nbutylJ-naphthamide (U.S. Patent 2,474,293) 66. l hydroxy 4-phenylazo-4-(p-tert.-butylphenoxy)-2-naphthanilide (U.S. Patent 2,521,908) 67. 2 (2,4-di-tert.-amylphenoxyacetamino)-4,6-dichloro-S-methylphenol (U.S. Patent 2,725,291) 68. 2 (a di-tert.amylphenoxy-n-butyrylarnino)-4,

6-dichloro-t-methylphenol 69. 6-{oc {4 [OL-'(2,4 di-tert.amylphenoxy)butyramido]-phenoxy}acetamido} 2,4 dichloro 3- methylphenol 70. 2 [3-(2",4" diamylphenoxy) acetamidolbenzamido-4-chloro-5-methylphenol 71. 1-(2,4,6 trichlorophenyl) 3 [3-(2",4"- di-tert.-amylphenoxyacetamido) benzamido] 5- pyrazolone (US. Patent 2,600,788)

72. 1-(2',4,6 trichlorophenyl)-3-[3"-(2",4-ditert.-amylphenoxyacetamido)-benzamido] 4-(pmethoxyphenyl-azo) -5 -pyrazo1one 6 73. N-(4 benz oyl'acetaminobenzenesulfonyl) N- ('y-phenylpropy1) -p-toluidine (U.S. Patent 2,298,- 443 74. u-o-Methoxybenzoyl-m-chloro 4-[u-(2,4-di-tert.- amylphenoxy) n butyramido] -acetanilide (Mc- Crossen U.S. Patent 2,728,658)

75. oc-{3-[oc (2,4-di-tert.amylphenoxy) acetamido-lbenzoyl}-2-rnethoxyacetanilide 76. 3 benzoylacetamido 4 methoxy-2',4'-di-tert.-

amylphenoxyacetanilide 77. 4 benzoylacetamido 3-methoxy-2,4-di-tert.-

amylphenoxyacetanilide Other couplers suitable for use in the emulsions of my invention comprise those disclosed in Spence and Carroll U.S. Patent 2,640,776, issued June 2, 1953; Weissberger et a1. U.S. Patent 2,407,210, issued September 3, 1946; and Weissberger et al. U.S. Patent 2,474,293, issued June 28, 1949.

The color-forming developers useful in my invention have been previously described in the prior art, and my invention is not to be restricted to the use of any particular color-forming developer. The color-forming, developers previously mentioned which I have found to be especially useful in my invention comprise aromatic primary amines containing an amino (substituted or not) or hydroxyl substituent. Phenylenediamines and substituted derivatives thereof containing a primary amino group have been found to provide excellent results when employed in combination with the formamidinothiomethyl compounds of my invention. Typical of such color-forming developers are the sulfonamido substituted p-phenylenediamines disclosed in Weissberger U.S. Patent 2,548,- 574, issued April 10, 1951, the substituted p-phenylenediamines disclosed in Weissberger et al. U.S. Patent 2,566,- 271, issued August 28, 1951. Other phenylenediamine color-forming developers can be employed to like advantage in the process of my invention.

The first developer employed in the process of my invention is generally a rapid developer of the MQ type, i.e., a combination of hydroquinone and Elon (p-N- methylaminophenyl) developer.

The photographic silver halide emulsions useful in the process of my invention can be prepared according to known methods, such as those described in Hewitson and McClintock U.S. Patent 2,618,556, issued November 18, 1952. Of course, emulsions prepared by other methods can be used to equal advantage in my invention. These emulsions can be chemically sensitized or not, as mentioned above. Additional chemical sensitizers useful in my invention comprise those disclosed in the c0- pending application Serial No. 550,495, filed December 1, 1955 (now U.S. Patent 2,886,437, issued May 12, 1958), in the name of D. E. Piper.

The following examples will serve to illustrate more fully the manner of practicing my invention.

Example 1 weight greater than 300 was added to a second portion of the same emulsion at a concentration of 5 gms. of the oleyl ether per mole of silver halide, and the emulsion coated onto a cellulose acetate support. The dried coating was then cut into several strips, identified coating series B below. One strip of each coating was exposed for. second to a SOO-Watt, 3000 K. light source on an -Eastman Type Ib sensitometer. The exposed coatings '7 were then developed for 3 minutes in adevelop'er having the following composition:

Sodium hexametaphosphate g 0.5 Sodium sulfite (anhydrous) g 40.0 N-methyl-p-aminophenolsulfate g 5.0 Hydroquinone g-.. 2.0 Sodium carbonate (monohydrate) g 25.0 Potassium bromide g 1.0 Potassium iodide (0.1% solution) cc. 2

Water to make one liter. (pH was 10.1 at 70 F.)

The coatings were then washed for two minutes.

Color development.-'Ihe above coatings were given a reversal exposure for about seconds (flash) with a No. 2 Photoflood set at a distance of 52 inches. The coatings were developed to an adequate D-max. in a developer having the following formula:

Sulfuric acid (conc.) cc 1.5

2 2,4-dlch1oro-5- (p-toluenesulfonamldo)-1-na.phthol.

The coatings were washed for ten minutes and treated for two minutes in a silver bleach bath having the following composition:

G. Potassium fierricyanide 100 Potassium bromide 10 Borax 7.5

Boric acid a 5.0

Water to make one liter.

The coatings were then treatedfor two minutes in a fixing bath having the composition given below, washed and dried. v G. Sodium thiosulfate (pentahydrate) 200 Sodium sulfite (anhydrous) 10 Water to make one liter.

1n the following table.

Coating Series A Coating Series B Cone, Compound No. g./liter D-max. Cyan D-max. Cyan Fog Fog none 3. 40 0. 18 3. 30 0. 31 0.15 3.10 0. 03 3. 30 .06 (b 0. no run no run 3. 16 .08 (c) 0.30 3. 50 .07 2. 90 11 The improvement obtained as a result of the use of one of the formamidinothiomethyl compounds of my invention is immediately apparent, in emulsions'with or without a polyethyleneglycol derivative. While color 8 density is maintained at a high level, the color fog has been materially reduced.

While the advantages of my invention are particularly noticeable in cyan development, they are also quite noticeable in providing improved results in magenta and yellow development, as illustrated in the following examples.

Example 2 i In a manner similar to that illustrated in Example 1 above, a portion of a' gelatino-silver-bromiodide emulsion which had been sensitized with a sulfur compound and a gold compound of the type described above, and the oleyl ether of a polyethyleneglycol having a molecular weight greater than 300 (5 g./mole of AgX), was coated on a cellulose acetate support. The coating was exposed for second to a -watt, 5400 K. light source on an Eastman Type Ib sensitometer. The exposed coating was then developed for 4 minutes in a developer having the following composition:

Sodium tetraphosphate g 0.5 Potassium bromide g 2.85 Potassium iodide (0.1% solution) cc 15 Sodium bisulfite g 4.2 N-methyl-p-aminophenolsu1fate 4.5 Sodium sulfite (anhydrous) g 75.9 Hydroquinone g-.. 2.8 Sodium carbonate (monohydrate) g 27.5 Hydroquinone sulfonate g 1.9

Isopropylamine g 6.43 Water to make one liter.

The coating was then washed for two minutes.

Color development.The above coating was given a reversal exposure for about 10 seconds (flash) with No. 2 Photofloods set at a distance of about 60 inches. The coating was developed 2 minutes in a color developer having the following composition:

' G. Sodium hexametaphosphate 0.5 Sodium sulfite 5.0 Color developer 1 1.5 Sodium carbonate (monohydrate) 20.0 Sodium bromide 0.22 Potassium iodide .002 6-nitrobenzimidazole nitrate .01 Coupler No. 45 0.5 Sodium hydroxide 0.7

Water to make one liter.

1 i-amino-3methyl-N,N-diethylanillne hydrochloride.

The coating was washed for 10 minutes and treated for 2 minutes in a silver bleach bath having the composition given above. The coating was then rinsed and treated for 2 minutes in a fixing bath having the composition given above, washed and dried. A second strip was given the same treatment except that the flash re-exposure was omitted. The D-max. and color (magenta) fog for the coating were then measured.

Another portion of the same emulsion was treated in exactly the manner described above, except that compound (a), as identified above, was added to the color developer (0.15 g./liter). The D-max. and magenta fog for this coating were also measured, the following tabulation showing the comparison between the untreated and treated coatings.

1 Development time-6 minutes.

' Example 3 An ordinary gelatino-silver-bromiodide emulsion sensitized with a sulfur sensitizer, a gold compound, and the oleyl ether of a polyethyleneglycol having a molecular weight greater than 300 (5.0 g./mole of AgX) was processed in exactly the manner described in Example 2 above, except that a yellow color-forming coupler was employed in place of the magenta developer of Example 2, while the concentration of compound (a) was reduced to 0.075 g./ liter for the processing of the second coating. The time of color development for the first coating, the color developer containing no formamidinothiomethyl compound, was 8 minuts, while the development time for the processing of the second coating in the color developer containing compound (a) was 30 min- Water to make one liter.

1 et-amino-3-methyl-N,N-diethylaniline hydrochloride.

Measurement of the D-max. and yellow fog for each of the coatings gave the following results:

D-max. Yellow Fog Control- 1. 23 0.86 Compound (a) 1. 22 0. 18

While it has been previously proposed to add various mercapto compounds to color developers, such compounds fail to maintain color density at a high level, although they do reduce color fog. For example, processing of an emulsion having the same composition as coating B of Example 1, the same developing compositions shown in Example 1 being used, except that 0.01 g./liter of 1-phenyl-5-mercaptotetrazole was added to the color developer in place of the formamidinothiomethyl compound of Example 1, gave the following results:

Color Cyan Develop- D-max. Fog

ment, min.

Control 4 3. 30 0. 31 1-phenyl-5-mercaptotetrazole 5 1. 42 0.

While the above mercapto compound did reduce the cyan fog to one-third the level of the coating treated with a color developer containing no antifoggant, it also caused a density loss of more than one-half.

While the above examples primarily illustrate the use of photographic emulsions which have been chemically sensitized with the oleyl ether of polyethylene glycol, it is to be understood that other condensates of alkylene oxides can be advantageously employed to sensitize such emulsions. Such condensates are generally referred to as alkylene oxide polymers, the alkylene oxides generally containing from 2 to 4 carbon atoms. Such alkylene oxide polymers include polyalkylene glycols and condensation products of alkylene oxides with organic compounds containing an active hydrogen atom, such as alcohols, amines, mercaptans, acids, amides, etc. Generally, such alkylene oxide polymers have a molecular weight of at least 300, as shown in U. S. application Serial No. 550,495, mentioned above. It is to be further understood that the emulsions employed in my invention need not be chemically sensitized, although particularly useful results have been obtained with emulsions which have been chemically sensitized with such alkylene oxide polymers.

The formamidinothiomethyl compounds useful in my invention can be added to the color developers either in the form of their free bases or in the form of acidaddition salts of these bases. Since the color developing solutions of my invention are strongly alkaline, the acidaddition salts are converted to the free bases, in which form they manifest their activity. It is to be understood that the term formamidinothiomethyl compound includes not only the free bases but also acid-addition salts of these bases.

As mentioned above, the compounds of Formula I can be prepared according to methods previously described in the prior art. For example, compound d above was prepared as follows:

Example A.S-carbethoxymethyl 1 phenyl 3 (4H- 1,2,4-triaz0l-3-yl)isothiourea 3-amino-1,2,4-triazole was boiled in dry dioxane with an equimolecular amount of phenyl isothiocyanate. There was obtained a 50 to 60 percent yield of the desired 1-phenyl-3-(3-triazolyl)thiourea as a white solid which was only slightly soluble in water and dioxane, but was readily soluble in dimethylformamide. It was recrystallized from its solution in dimethylformamide by addition of water to give white crystals melting at 230- 234 C.

The above thiourea compound was refluxed for 2 to 4 hours with ethyl chloroacetate in dry dioxane, yielding pale yellow solid which melted gradually with decomposition above 280 C. Recrystallization of this solid from dimethylformamide yielded S carbethoxymethyl 1- phenyl 3 (4H 1,2,4 triazol 3 yl) isothiourea as a solid melting at 296302 C. with decomposition.

Compound 0 above was prepared according to the directions given in 1 our. Am. Chem. Soc, vol. 77 (1955), page 6231.

As mentioned above,"the color-forming compounds of my invention can be prepared according to methods previously described in the literature. The following two examples will serve to illustrate methods of preparing two typical couplers useful in my invention.

Example B.N-benzoylaceto-o-anisidine A two-liter flask was fitted with a one-holed rubber stopper and a steam-jacketed Friedrichs condenser. To the top of this condenser was fitted a standard distillation head, thermometer and downward pointing Liebig condenser cooled with water. The flask was then charged with 600 cc. of neutral histological xylene, 74 g. (0.6 mol.) of o-anisidine and 115 g. (0.6 mol.) of ethyl benzoylacetate. The flask was refluxed for minutes at such a rate that most of the boiling xylene condensed in the steam-jacketed condenser, but some distillate was condensed in the cold condenser. The temperature at the top of the hot condenser was C. at the beginning of the reflux period, but slowly dropped to 70 C. at the end of the period. During this time, 45 cc. of distillate was collected from the cold condenser. The heating mantle was turned ofli, 500 cc. of ligroin was added to the hot solution, and the material allowed to cool for 16 hours. The resulting crystalline product was broken up, filtered olf and air-dried. A yield of 90 g. of crude product was obtained, M.P. 868 C. Recrystallization of the product from 520 cc. of methanol yielded 76.3 g. of product, M.P. 86-8 C. Yield was 47.4 percent of theory.

Example C.3- (p-nitrophenoxyacetylamino) -1- (2',4',6'- trichlorophenyl) -5-pyraz0l0ne A two-liter round-bottomed flask equipped with a condenser and a mechanical stirrer, was charged with 450 cc. of acetonitrile, 32 g. (0.1 mol.) of 1-(2,4,6-trichlorophenyl)-3-amino-5-pyrazolone (US. Patent 2,600,788),

and 27 g. (0.13 mol.) of p-nitrophenoxyacetyl chloride. The mixture was refluxed on the steam bath for three and one-half hours with good stirring, complete solution occurring when reflux temperature was attained. At the end of the reflux period, the crystalline product, which had separated from the refluxing mixture, was suctionfiltered from the hot mother liquors. It was then washed on the funnel with successive portions of acetonitrile, ethanol, water, ethanol, and ether. After drying overnight in a steam cabinet, there were obtained 47 g. (89% of theory) of the desired product as a white solid, M.P. 244-6 C.

The p-nitrophenoxyacetyl chloride used above was prepared as follows: In a SOD-ml. flask were mixed 19.7 g. (0.1 mole) of p-nitrophenoxyacetic acid and 100 ml. of thionyl chloride. The mixture was refluxed for hours on a steam bath and the excess thionyl chloride removed under reducdpressure. The removal of the thionyl chloride wascontinued until the residue had reached constant weight. The acid chloride was used without purification and gave good results. It can be crystallized from dried ligroin to obtain a white crystalline material melting at 86-87 C.

The p-nitrophenoxyacetic acid used above was prepared as follows: In a 5-liter flask were placed 278 g. (2 moles) of p-nitrophenol, 190 g. (2 moles) of chloroacetic acid, 168 g. (4.2 moles) of sodium hydroxide and 2 liters of water. The mixture was boiled in the open flask until it showed a neutral reaction to litmus paper. The reaction temperature reached 115 C. and some water was evaporated. When the neutral point had been reached (2.5-3 hours) an additional 84 g. (2.05 moles) of sodium hydroxide and 95 g. (1 mole) of chloroacetic acid were added to the flask and the heating continued until a neutral reaction again resulted.

To the cooled reaction mixture were added 500 ml. of concentrated hydrochloric acid with stirring. The solid formed was filtered, slurn'ed with 3 liters of ice cold water and again filtered and washed. with 1. liter of ice cold water. The dry product melted at 182184 C. and weighed 300 g. Yield was 76% of the 394 g. theory. It can be crystallized from denatured alcohol, if desired.

What I claim as my invention and desire secured by Letters Patent of the United States is:

1. A developing composition for color photography comprising an arylenediamine color developer and a compound selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of a hydrogen atom, an alkyl group containing from 1 to 3 carbon atoms, and a monocyclic aryl group of the benzene series containing from 6 to 7 carbon atoms, R represents an amino group, and R represents a member selected from the group consisting of a carbalkoxyl group containing from 2 to 5 carbon atoms, an alkyl group containing from 1 to 4 carbon atoms, a tetrazaindenyl group, a pyridyl group, and an amino carbonyl group.

2. A developing composition for color photography comprising alkali, an alkaline sulfite, a p-phenylenediamine color developer, and a compound selected from those represented by the following general formula:

group of the benzene series containing from'6 to 7 carbon atoms, R represents an amino group, and R;

represents a'member selected from the group consisting of a carbalkoxylgroup containing from 2 to 5 carbon atoms, an alkyl group containing from '1 to 4 carbon atoms,a tetrazaindenyl group, a pyridyl group, and an aminocarbonyl group. 4

3. A photographic developer for color photography comprising a strongly alkaline solution of a p-phenylenediamine photographic developing agent, an alkali metal sulfite and a compound selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of a hydrogen atom, an alkyl group containing from 1 to 3 carbon atoms, and a monocyclic aryl group of thebenzene series containing from 6 to ,7 carbon atoms,"R represents an amino group, and R, representsa'member'selected from the group consisting of a carbalkoxy group containing from 2 to 5 carbon atoms, an alkyl group containing from '1 to 4 carbon atoms, a tetrazaindenyl group, a pyridyl group, and an aminocarbonyl "group.

4. A developing composition for color photography comprising a p-phenylenediamine color developer, an alkali metal sulfite, and a compound selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of a hydrogen atom, an alkyl group containing from 1 to 3'carbon atoms, and a'monocyclic aryl group of the benzene series containing from 6 to 7 carbon atoms, R represents an amino group, and R represents a member selected from the group consisting of a carbalkoxyl group containing from 2 to 5 carbon atoms, an alkyl group containing from 1 to 4 carbon atoms, a tetrazaindenyl group, 'a pyridyl group, and an aminocarbonyl group.

5. A developing composition for color photography comprising a p-phenylenediamine color developer, an alkali metal sulfite, and a compound selected from those represented by the following general formula:

wherein R represents a member selected from the group consisting of a hydrogen atom, an alkyl group containing from 1 to 3 carhon atoms, and a monocyclic aryl group of the benzene series containing from 6 to 7 carbon atoms, R represents an amino group, and R represents a tetrazaindenyl group.

6. A photographic developing composition for color photography comprising a p-phenylenediamine color developer, an alkali metal sulfite, and 2-formamidinothiomethyl-4-hydroxy-6-methyl-l,3,3a,7-tetrazaindene.

7. A developing composition for color photography comprising a p-phenylenediamine color developer, an alkali metal sulfite, and bis(2-formamidinothiornethyl- G-methyl-l,3,3a,7-tetrazainden-4-yl)sulfide.

8. A developing composition for color photography comprising a p-phenylenediamine color developer, an alkali metal sulfite, and 2-S-thiouroniumethanesulfonate.

9. A developing composition for color photography comprising a p-phenylenediamin'e color developer, an alkali metal sulfite, and S-carbethoxymethyl-l-phenyl-3- (4H-1,2,4-triazol-3-yl)isothiourea.

10. A developing composition for color photography comprising a p-phenylenediamine color developing cornpou'nd,'an alkali metal sulfite, a color-forming compound capable of coupling with the oxidation products of said p-phenylenediamine color developing compound to produce a colored image selected from the group consisting of cyan, magenta and yellow, and a compound selected balkoxyl group containing from 2 to 5 carbon atoms, from those represented by the following general formula: an alkyl group containing from 1 to 4 carbon atoms, a

tetrazaindenyl group, a pyridyl group, and an aminocar- I bonyl group.

R 5 wherein R represents a member selected from the group References Cited in the file of this patent consisting of a hydrogen atom, an alkyl group containing UNITED STATES PATENTS from 1 to 3 carbon atoms, and a monocyclic aryl group of the benzene series containing from 6 to 7 carbon gig Mannes et 1941 atoms, R represents an amino group, and R represents 10 3,087 Dersch et a1 1948 a member selected from the group consisting of a car- 2,514,650 Knott et July 1950