US3592656A - Photographic silver halide materials supersensitized with a combination of a triazole and a cyanine dye - Google Patents

Abstract

PHOTOGRAPHIC SILVER HALIDE EMULSIONS ARE SUPERSENSITIZED WITH THE COMBINATION OF A PHOTOGRAPHIC SPECTRAL SENSITIZING METHINE DYE AND A HETEROCYCLIC COMPOUND SELECTED FROM A PYRAZOLE, A 5-PYRAZOLONE, A 3-PYRAZOLONE, A 3,5-PYRAZOLIDINEDIONE, A TRIAZOLE, A TETRAZZOLE, A XANTHINE, AN IMIDAZOLE, AN IMIDAZOLIDINE AND AN AMIDAZOLINIUM SALT.

Description

United States Patent Oihce 3,592,656 Patented July 13, 1971 Int. Cl. G03c 1/28 US. Cl. 96--126 6 Claims ABSTRACT OF THE DISCLOSURE Photographic silver halide emulsions are supersensitized with the combination of a photographic spectral sensitizing methine dye and a heterocyclic compound selected from a pyrazole, a S-pyrazolone, a 3-pyrazolone, a 3,5-pyrazolidinedione, a triazole, a tetrazole, a xanthine, an imidazole, an imidazolidine and an imidazolinium salt.

This invention relates to novel photographic silver halide emulsions containing a new supersensitizing combination.

It is well known in the photographic art that certain cyanine dyes extend the spectral sensitivity of photographic emulsions. It is further known that a number of such dyes in combination with each other .or with certain other compounds markedly alter the sensitivity of photographic emulsions, for example in relative speed, compared with the individual dyes by themselves in such emulsions. While supersensitizing combinations of the above kind have been proposed for various photographic uses, only a relatively few have proven entirely satisfactory for commercial photographic applications. Consequently there is still need in the art for improved supersensitizing combinations comprising methine cyanine dyes.

It is, accordingly an object of this invention to provide a new class of supersensitizing combinations for photographic silver halide emulsions.

Another object of this invention is to provide novel emulsions containing novel supersensitizing combinations, and photographic elements prepared therewith.

Other objects of the invention will be apparent from this disclosure and the appended claims.

I have now made the important discovery that new and improved supersensitizing combinations for lightsensitive photographic silver halide emulsions are produced with (l) a heterocyclic compound selected from a pyrazole, a S-pyrazolone, a 3-pyrazolone, a 3,5-pyrazolidinedione, a triazole, a tetrazole, a Xanthine, an imidazole, an imidazolidine and an imidazolinium salt; and, (2) a photographic spectral sensitizing methine dye.

Especially good results are obtained in accordance with this invention when the heterocyclic compound is a pyrazolone; a l,2,3,4-tetrazole; a 1,2,4-triazole; an imidazole; or, an imidazolinium salt. Some particularly useful (III) N wherein A represents the atoms required to complete an imidazole nucleus, such as imidazole or benzimidazole; R represents a hydrogen atom, an alkyl group of from 1 to 4 carbon atoms, such as methyl, 2-carboxypropyl, butyl, etc., or an aryl group such as phenyl; R represents an aryl group, such as phenyl or 2,4,6-trichlorophenyl; R represents an aryl group such as phenyl, or an amino group such as an arylamino group, e.g., 3,4-dichloroani1ino, anilino, 4-methylsulfonamidophenylamino, or an amido group such as 3,5-disulfobenzamido; R represents a hydrogen atom or an arylthio group such as 3-octadecyclarbamylphenylthio; R represents a hydrogen atom or an aryl group such as phenyl; R represents an aryl group such as phenyl, 4 cyanophenyl, 4 methoxyphenyl, 4 carboxyphenyl, naphthyl, a benzoyl group, or pyridyl (EV-pyridyl or 4'- pyridyl); R and R each represents a hydrogen atom, or an aryl group such as phenyl; and, R represents a hydrogen atom or an amino group.

Typical heterocyclic compounds which can be used in this invention include those listed in the following Table 1.

phenyD-S-pyrazolone. 3-(3,4-dichloroanilino)-1-(2,4, -trichlorophenyl)-5- pyrazolone.

VIII bis[5m%thyl-2-p-sulfophenyl-3-pyrazolone-(4)1-meth1ne oxono IX 3-(3,5-dicarbeth0xybenzamido)-4(3-oetadecylearbamylphenylthio)-1-phony1-5-pyrazolone. X 1,2-d1pl enyl-3,S-pyrazolidinedione. XI. p-(3,5-d1phenyl-2-pyrazolin l-yl)benzaldehyde. XII. 5-benzyl-5phenyl-4-phenylazopyrazole. XIII. 1,5-diphenyltetrazole. XIV 1,3-diphenyl-5-hydroxy-pseudo-tetrazole. $6 5 N HO-(l3 N-H 1L N C 5H5 XV 5-(3,4-d.imethoxyphenyl)tetrazole. XVII- 5-(4-cyanophenyl) tetraZOle-HzO XIX- 5-(4-earboxyphenyl) tetrazole- H2O XX. 5-pheny1tetrazole.

5-benzoyltetraz0le.

XXVIA 4-(N-methyl-p-toluenesulfonamido)-l-(1-phenyl-5 tetrazolyloxy)-2methylthi0benzene.

XXVII 3-amino-5-phenyl-l,2,4-trizaole.

1,5-diphenyl-1,2,4-triazole. 4amino-3,5-di(p-aminophenyl)-l,2,4trlazolo.

XXXI. Poly(l,2,4triazole). XXXII. 4-(5-cyanomethyl-1-phenyl-l,2,4-triazol-3-yl)- benzaldehyde-Nchlorophenylhydrazone. XXXIIL 3,3tp-pllienylenebis (fi-cyanomethyl-1-pheny1-1 2,4-

nazo XXXIV 4-phenylimidazole. XXXV 2-(4,S-diphenyl-Z-imidazolyl)phenol. XXXVI 1,3-diphenylimidazolidine. XXXVIL. l,3-diphenylimidazolinium perchlorate. XXXVIII 2(3-pyridyl)benzimidazole. XXXIX. 2-(4pyridyl)benzimidazole. XL. B-(Z-mercaptobeuzimidaz0le)propionie acid. XLI 3-isopentyl-2,6-dithioxanthine.

The above classes of heterocyclic compounds are well known and methods for their preparations are described in the various prior art patent references and literature. Some of the references relating to a number of the specific compounds mentioned in above Table 1 are included herein for illustrative purposes, for example, reference can be had to Chemical Abstracts 22, P3170 25, P3364 32, 5831 41, P1699e; 45, P7603 c; 47, 4335c; 49, 9153c: 51, 13876i; 53, 2216c; 53, 4317d; 54, 14234e; 55, 1644c; 55, 2626c; 55, 16520c; 62, P177821; etc.

The rnethine dye spectral sensitizers of the invention are represented by the following formulas:

wherein e and 12 represent a positive integer of from 1 to 2; d and In each represents a positive integer of from 1 to 3; L represents a rnethine linkage, e.g. =CH,

etc.; R and R each represents an alkyl group, including substituted :alkyl (preferably a lower alkyl containing from 1 to 4 carbon atoms), e.g., methyl, ethyl, propyl, isopropyl, butyl, hexyl, cyclohexyl, decyl, dodecyl, etc., and substituted alkyl groups (preferably a substituted lower alkyl containing from 1 to 4 carbon atoms), such as a hydroxyalkyl group, e.g., fi-hydroxyethyl, w-hydroxybutyl, etc., an alkoxyalkyl group, e.g., B-methoxyethyl, w-blltoxybutyl, etc., a carboxyalkyl group, e.g., B-carboxyethyl, w-carboxybutyl, etc.; a sulfoalkyl group, e.g., fl-sulfoethyl, w-sulfobutyl, etc., a sulfatoalkyl group, e.g., fi-sulfatoethyl, w.-sulfatobuyl, etc., an acyloxyalkyl group, e.g., [3- acetoxyethyl, 'y-acetoxypropyl, w-butyryloxybutyl, etc., an alkoxycarbonylalkyl group, e.g., fl-methoxycarbonylethyl, w-ethoxycarbonylbutyl, etc., or an aralkyl group, e.g., benzyl, phenethyl, etc., or, any aryl group, e.g., phenyl, tolyl, naphthyl, methoxyphenyl, chlorophenyl, etc.; X represents an acid anion, e.g., chloride, bromide, iodide, thiocyanate, sulfamate, perchlorate, p-toluenesulfonate, methylsulfate, etc.; R represents a hydrogen atom, an alkyl group of 1-4 carbon atoms, including substituted alkyl, e.g., methyl, ethyl, isopropyl, butyl, dimethylaminopropyl, benzyl, phenethyl, etc. or an aryl group, e.g., phenyl, tolyl, chlorophenyl, methoxyphenyl, naphthyl, etc.; D represents an atom of oxygen or sulfur; or the non-metallic atoms necessary to complete a diazole ring, e.g., D is NR wherein R is an alkyl group of 1 to 4 carbon atoms, e.g., methyl, ethyl, isopropyl, butyl, etc., or an aryl group such as phenyl, tolyl, chlorophenyl, rnethoxyphenyl, naphthyl, etc.; Z and Z each represents the non-metallic atoms necessary to complete the same or different 5- to 6-membered heterocyclic nucleus such as used in cyanine dyes which may contain a second hetero atom such as oxygen, sulfur, selenium or nitrogen, such as the following nuclei:

a thiazole nucleus, e.g., thiazole, 4-methylthiazole, 4- phenylthiazole, S-methylthiazole, S-phenylthiazole, 4,5- dimethylthiazole, 4,5-diphenylthiazole, 4-(2-thienyl) thiazole, benzothiazole, 4-chlorobenzothiazole, S-chlorobenzothiazole, 6-chlorobenzothiazole, 7-chlorobenzothiazole, 4-methylbenzothiazole, S-methylbenzothiazole, 6-methylbenzothiazole, 5-bromobenzothiazole, 6-bromobenzothiazole, 5 phenylbenzothiazole, 4 methoxybenzothiazole, S-methoxybenzothiazole, 6-methoxybenzothiazole, 5-i0dobenzothiazole, 6 iodobenzothiazole, 4-

ethoxybenzothiazole, S-ethoxybenzothiazole, tetrahydrobenzothiazole, 5,6 dimethoxybenzothiazole, 5,6 dioxymethylenebenzothiazole, S-hydroxybenzothiazole, 6 hydroxybenzothiazole, naphtho[2,1 d]thiazole, naphtho- [l,2-d]thiazole, 5 methoxynaphtho[2,3 d]thiazole, 5-

ethoxynaphtho[2,3-d1thiazo1e, 8 methoxynaphtho[2,3-d]

thiazole, 7-methoxynaphtho[2,3-d]thiazole, 4 methoxythianaphtheno-7,6'-4,5-thiazole, etc.;

an oxazole nucleus, e.g., 4 methyloxazole, 5 methyloxazole, 4-phenyloxazole, 4,5-diphenyloxazole, 4-ethy1- oxazole, 4,5-dimethyloxazole, S-phenyloxazole, benzoxazole, S-chlorobenzoxazole, S-methylbenzoxazole, 5- phenylbenzoxazole, 6-methylbenzoxazole, 5,6-dimethylbenzoxazole, 4,6 dimethylbenzoxazole, 5 methoxybenzoxazole, 5 ethoxybenzoxazole, 5-chlor0benzoxazole, 6-methoxybenzoxazole, S-hydroxybenzoxazole, 6- hydroxybenzoxazole, naphtho [2,1-d]oxazole, naphtho- [l,2-d]-oxazole, etc.;

a selenazole nucleus, e.g., 4-methylselenazole, 4-phenylselenazole, benzoselenazole, 5-chlorobenzoselenazole, 5-me'thoxybenzoselenazole, S-hydroxybenzoselenazole, tetrahydrobenzoselenazole, naphtho[2,1-d]selenazole, naphtho[1,2-d]se1enazole, etc.;

a thiazoline nucleus, e.g., thiazoline, 4-methylthiazoline,

etc.;

a pyridine nucleus, e.g., 2-pyridine, S-methyI-Z-pyridine,

4-pyridine, 3-methyl-4-pyridine, etc.;

a quinoline nucleus, e.g., 2-quinoline, 3-methyl-2-quinoline, S-ethyI-Z-quinoline, 6-chloro-2-quinoline, 8-chloro- Z-quinoline, 6-methoxy-2-quinoline, 8-ethoxy-2-quinoline, 8-hydroxy-2-quinoline, 4-quinoline, 6-rnethoxy-4- quinoline, 7-methyl-4-quinoline, 8-chloro-4-quinoline, 1- isoquinoline, 3,4-dihydro-l-isoquinoline, 3-isoquino1ine, etc.;

a 3,3 dialkylindolenine nucleus, e.g., 3,3 dimethylindolenine, 3,3,5-trimethylindolenine, etc.; and,

an imidazole nucleus, e.g., imidazole, l-alkylimidazole, l-

alkyl-4-phenylimidazole, 1-alky1-4,5-dimethylimidazole, benzimidazole, 1 alkylbenzimidazole, 1 aryl-5,6-dichlorobenzimidazole, l-alkyl-lH-naphth[ 1,2-d] imidazole, 1-aryl-3H-naphth[ 1,2-d1imidazole, l-alkyl-S-methoxy-1H-naphtha[1,2-d]imidazole, etc.;

and QQ represents the non-metallic atoms necessary to complete a 5- or 6-membered heterocyclic ketomethylene nucleus of the type used in merocyanine dyes typically containing a hetero atom selected from nitrogen, sulfur, selenium, and oxygen, such as a 2-pyrazolin-5-one nucleus, e.g., 3-methyl-1-phenyl-2- pyrazolin-S-one, 1-phenyl-2-pyrazolin-5-one, 1-(2-benzothiazolyl)3-methyl-2-pyrazolin-5-one, etc.;

an isoxazolone nucleus, e.g,, 3-phenyl-5(4H)-is oxazolone,

3-methyl-5 (4H)-isoxazolone, etc.;

an oxindole nucleus, e.g., 1-alky1-2-oxindoles, etc.;

a 2,4,6-triketohexahydropyrimidine nucleus, e.g., barbituric acid or 2-thiobarbituric acid as well as their 1- alkyl (e.g., l-methyl, l-ethyl, l-propyl, l-heptyl, etc.) or 1,3-dialkyl (e.g., 1,3-dimethyl, 1,3-diethyl, 1,3-dipropyl, l,3-diisopropyl, 1,3dicyclohexyl, 1,3-di(fl-me thoxyethyl), etc.; or 1,3-diaryl (e.g., 1,3-diphenyl, 1,3- di(p-chlorophenyl) 1,3 di(p-ethoxycarbonylphenyl), etc.); or l-aryl (e.g., 1- phenyl, l-p-chlorophenyl, 1-pethoxycarbonylphenyl), etc.) or 1-alkyI-3-aryl (e.g., 1- ethyl-3-phenyl, 1-n-heptyl-3-phenyl, etc.) derivatives;

a rhodanine nucleus (i.e., 2-thio-2,4-thiazolidinedione series), such as rhodanine, 3-alkylrhodanines, e.g., 3-ethylrhodanine, 3 allylrhodanine, etc., 3 carboxyalkylrhodanines, e.g., 3-(2-carboxyethyl)rhodanine, 3-(4- carboxybutyl)rhodanine, etc., 3 sulfoalkylrhodanines, e.g., 3 (2 sulfoethyl)rhodanine, 3-(3-sulfopropyl)- rhodanine, 3-(4-sulfobutyl)rhodanine, etc., or 3-arylrhodanines, e.g., 3-phenylrhodanine, etc.;

a 5,7 dioxo-6,7-dihydro-5-thiazolo[3,2-a] pyrimidine nucleus, e.g., 5,7 dioxo-3-phenyl-6,7-dihydro-S-thiazolo- [3,2-a]pyrimidine, etc.;

' a 2-thio 2,4-oxazolidinedione nucleus (i.e., those of the 2-thio-2,4(3H,5H)-oxazoledione series) e.g., 3-ethyl-2- thio-2,4 oxazolidinedione, 3-(2-sulfoethyl)-2-thio-2,4- oxazolidinedione, 3-(4 sulfobutyl) 2-thio-2,4-oxazolidinedione, 3-(3-carboxypropyl)-2-thio-2,4 oxazo1idinedione, etc.;

a thianaphthenone nucleus, e.g., 3-(2H)-thianaphthenone,

etc.;

a 2-thio-2,S-thiazolidinedione nucleus (i.e., the 2-thio-2,5- -(3H,4H)-thiazoledione series), e.g., 3-ethyl-2-thio-2,5- thiazolidinedione, etc.;

a 2,4-thiazolidinedione nucleus, e.g., 2,4-thiazolidinedione, 3-ethyl-2,4-thiazolidinedione, 3-phenyl-2,4-thiazolidine dione, 3-u-naphthyl-2,4-thiazolidinedione, etc.;

a thiazolidinone nucleus, e.g., 4-thiazolidinone, 3-ethyl-4- thiazolidinone, 3-phenyl-4-thiazolidinone, 3-u-naphthyl- 4-thiazolidinone, etc.;

2-thiazolin-4-one nucleus, e.g., 2 ethylmercapto-Z- thiazolin-4-one, 2-alkylphenylamino-2-thiazolin-4-one,

2-diphenylamino2-thiazolin-4-one, etc.;

a 2-imino-4-oxazolidinone (i.e., pseudohydantoin) nucleus;

a 2,4-imidazolidinedione (hydantoin) nucleus, e.g., 2,4- imidazolidinedione, 3-ethyl-2,4-imidazolidinedione, 3- phenyl-2,4-imidazolidinedione, 3-or-naphthyl-2,4-imidazolidinedione, 1,3 diethyl-2,4-imidazolidinedione, 1- ethyl-3-phenyl 2,4 imidazolidinedione, 1-ethy1-3-anaphthyl 2,4 imidazolidinedione, 1,3-diphenyl-2,4- imida zolidinedione, etc.;

a Z-thio-2,4-imidazolidinedione (i.e., 2 thiohydantoin) nucleus, e.g., 2-thio-2,4-imidazolidinedione, 3-ethyl-2- thio-2,4-imidazolidinedione, 3 (4-sulfobutyl)-2-thio- 2,4 imidazolidinedione, 3 (2-carboXyethyl)-2thio- 2,4-imidazolidinedione, 3 phenyl-2-thio-2,4-imidazolidinedione, 3-u-naphthyl-2-thio-2,4-imidazolidinedione, 1-ethyl-3-phenyl-2-thi0-2,4-imidazolidinedione, l-ethyl- 3-a-naphthyl-Z-thiO-Z,4-imidazolidinedione, 1,3-diphenyl-2-thio-2,4-imidazolidinedione, etc.;

a Z-imidazolin-S-one nucleus, e.g., 2-propylmercapto-2- imidazolinS-one, etc.

Typical cyanine spectral sensitizing dyes of the invention represented by Formulas IV, V and VI above include those listed in the following table.

benzothiazolylideney methylene]-6-methyl-4H- pyran.

L 1,1-diethyl-2,2-oyanine iodide. M 3,3-diethyloxacarbocyanine iodide. N 1,3-diethylthia-4-carbocyanine iodide.

1,3-diethyloxai carbooyanine iodide.

3 3'-di- 3-hydroxyethy]thiadicarbocyanine iodide.

3 3-di-flhydroxyethylthiadicarbocyanine bromide.

-diethy1oxatricarbocyanine iodide.

3-diethyl-4,5,4,5-naphthothiadicarbocyanine iodide.

3,3-dimethyl-8,12-diphenoxyoxadicarbocyanine iodide.

10-oyano-3,3'-diethy1o radiearbocyanine iodide.

, -tetraphenylthiazolodicarbocyanine iodide.

anine hydroxide.

W Anhydro-3-ethyl-5-phenyl-1-(4-sulfobutyl)thia-4-carbocyanine hydroxide. X 3,3'-diethylthiadicarbocyanine iodide.

. 5-[di-(1-ethyl-2(1H)-B-naphthothiazolylidene)isopropylidenel- 1,3-di(fl-methoxyethyl)-barbitu ric acid.

Z 2[ (Z-benzothiazolylethoperchlorate)rnethylene1-3-(B-dimethylaminopropyl)-5-[(l-methylnaphtho[1,2-d]thiazolin-2-ylidene)- l-phenylethylidene]-4thiazolidinone.

The methine dyes of the invention illustrated by those listed in above Table 2 have been previously described in the literature and methods for their preparations are well known. Included among the more pertinent references are the following.

Zeh et al. U.S. Pat. No. 2,068,047 issued 1/ 19/37 Koslowsky U.S. Pat. No. 2,107,379 issued 2/8/38 Mees U.S. Pat No 2,158,883 issued 5/16/39 Carroll et al. U.S. Pat. No. 2,177,635 issued 10/3/39 Brooker et al. U.S. Pat. No. 2,213,238 issued 9/3/40 Brooker U.S. Pat. No. 2,307,916, issued 1/12/43 Brooker et al. U.S. Pat. No. 2,313,922, issued 3/16/43 Schneider U.S. Pat. No. 2,374,505 issued 4/24/45 Falleson et al. U.S. Pat. No. 2,378,917 issued 6/26/45 Brooker U.S. Pat. No. 2,454,629 issued 11/23/48 Thompson U.S. Pat. No. 2,535,993 issued 12/26/50 Carroll et a1. U .S. Pat. No. 2,950,196 issued 8/23/60 Jones U.S. Pat. No. 2,961,318 issued 11/22/60 Tabor et al. U.S. Pat. No. 3,335,010 issued 8/8/67 Brooker et al. U.S. Patent Reissue No. 24,292, Reissued 3/ 19/57 British Pat. No. 435,235 accepted 8/ 28/ 35 Dye K can be prepared by heating compounds having the following formulas:

in triethylamine and ethanol, to obtain an intermediate of the formula:

02115 The above intermediate is then reacted with a compound of the formula:

6 CHa by heating in pyridine and triethylamine, to obtain dye K.

According to the invention, one or more of the heterocyclic compounds represented by Formulas I, II, III or IIIa above are incorporated with one or more of the cyanine dyes represented by Formulas IV, V and VI above. The invention is particularly directed to gelatinosilver-halide developing-out emulsions. However, the supersensitizing combinations can also be employed in silver halide emulsions in which the carrier of vehicle is a hydrophilic colloid other than gelatin, such as, for example, albumin, agar-agar, .gum arabic, alginic acid, etc., or a hydrophilic resin such as polyvinyl alcohol, polyvinyl pyrrolidone, a cellulose ether, a partially hydrolyzed cellulose acetate, acrylamide polymers, etc., which has no deleterious efiect upon the light sensitive silver halide. The heterocyclic compounds of Formulas I, II, III and IIIa and the dyes of Formulas IV, V and VI, can be employed in the combinations of the invention in various concen trations depending upon the particular emulsion, concentration of the silver halide, particular results desired, etc. The optimum concentration of an individual sensitizing dye can be determined in a manner well known to those skilled in the art by measuring the sensitivity of a series of test portions of the same emulsion, each portion containing a different concentration of the sensitizing dye. In general, the heterocyclic compounds in my invention have little or no sensitizing action by themselves alone in the emulsions employed. Ordinarily, the optimum or near optimum concentration of the cyanine dyes herein is of the order 001 to 1.2 g. per mole of silver halide in the emulsion, and that of the heterocyclic compound herein is of the order of from about 0.02 to 5.0 g., but generally in the range of about 0.3 to 1.0 g., per mole of silver halide. The preferred combinations range about from 10 to 50% by weight of the cyanine dye and conversely about from 90 to 50% by weight of the heterocyclic compound.

The methods of incorporating sensitizing dyes in silver halide emulsions are well known to those skilled in the art and these known techniques are employed in dispersing the dyes of the invention in the emulsions. In practicing my invention the sensitizing dyes and the heterocyclic compounds can be directly dispersed in the emulsions, or they can first be dissolved in some convenient solvent, such as pyridine, methyl alcohol, acetone, etc. (or mixtures of such solvents), or diluted with water in some instances, and added to the emulsions in the form of these solutions. If desired, the components can be separately dissolved in a given solvent and added separately to the emulsion, or they can be dissolved in the same or different solvent and these solutions mixed together before addition is made to the silver halide emulsions. The dyes and heterocyclic compounds of the invention are dispersed in the finished emulsions in such manner as to be uniformly distributed throughout the emulsions prior to coating on a suitable support, such as paper, glass, cellulose ester film, polyvinyl resin film (e.g., polystyrene film, polyvinyl chloride film. etc.), polyester film, etc. The following procedure has been found quite satisfactory: Stock solutions of the dyes and heterocyclic compounds of Formulas I, II, III and IIIa and the dyes of Formulas IV, V and VI above are prepared by separately dissolving these in appropriate solvents as described above. Then, to the flowable silver halide emulsion, the desired amount of stock solution of one of the dyes is slowly added while stirring the emulsion. Stirring is continued until the dye is thoroughly incorporated in the emulsion. Then, the desired amount of stock solution of one of the heterocyclic compounds is slowly added to the emulsion while stirring. Stirring is continued until the added materials are incorporated in the emulsion. The supersensitized emulsions can then be coated on a suitable support and the coating allowed to dry. In some instances, it may be desirable to heat the supersensitized emulsion for a few minutes before coating onto the suitable support. The details of such coating techniques are well known to those skilled in the art. The foregoing procedure and proportions are to be regarded only as illustrative. Clearly, the invention is directed to any silver halide emulsion containing a supersensitizing combination of the invention, e.g., gelatinosilver chloride, -chlorobromide, -chloroiodide, -chlorobromoiodide, -bromoiodide, etc., emulsions. Fine grain photographic emulsions, such as those described by Sutherns in US. patent application Ser. N0. 622,034, filed Mar. 10, 1967, can also be supersensitized in accordance with this invention.

The emulsions of this invention can contain the chemical sensitizers, speed increasing compounds, plasticizers, hardeners and coating aids, and the silver halide grains can be dispersed in any of the binders, that are described and referred to by Graham et al. in US Pat. 3,046,129 issued July 24, 1962.

The following examples are included for a further understanding of the invention.

EXAMPLES 1 TO 19 These examples illustrate the supersensitization produced with the compounds containing the pyrazole nucleus in combination with various methane dyes of the invention. The testing procedure and the results thereof are set forth in the following description and Table 3.

are) The specified cyanine dyes and heterocyclic compounds are identifiable from Tables 1 and 2 above.

To different portions of the same batch of melted gelatino-silver bromoiodide emulsion, containing 0.77 mole percent iodide, of the type described by Trivelli and Smith, Phot. Journal, 79, 330 (1939), are added mg. per mole of silver of dye and the heterocyclic compounds in the proportions given in Table 3 hereinafter. In each case, after being digested at about 50 C. for 10 minutes, the emulsion is coated at a coverage of 432 mg. silver per square foot on a cellulose acetate film support. A sample of each coating is exposed on an Eastman IB Sensitometer to light from a tungsten source modulated by a step-wedge and Kodak Wratten No. 16 filter and processed for three minutes in Kodak Developer D-l9 which has the following composition:

G. N-methyl-p-aminophenol sulfate 2.0 Hydroquinone 8.0 Sodium sulfite (desiccated) 90.0 Sodium carbonate (monohydrate) 52.5 Potassium bromide 5.0

Water to make 1.0 liter.

' and then fixed in a conventional sodium thiosulfate fixing bath, washed and dried. Densitometric measurements are then made of the developed images of each coating. The relative speed values are determined by the exposure necessary to produce a density of 0.3 above fog, an arbitrary relative speed of 100 being chosen for the control containing only dye. The results are listed in the following table together with the values for gamma and fog.

TABLE 3.-SUPERSENSITIZATION BY PYRAZOLE TYPE 00 MP0 UN DS (Addendum) Dye N 0.. 80 mg. per Addendum .3 mole of to 10 gJmole Relative Example No. silver silver speed 7 Fog A 100 2. 40 06 A. 170 2. 74 06 A 182 2. 40 08 B 100 1. 06 B 174 1. 99 06 A 100 2. 34 06 A 234 2. 72 08 A 112 2. 78 06 A 214 2. 70 08 A 200 2. 70 08 B 100 2. 06 06 B 155 1. 96 09 B 151 1. 90 06 B 151 2. 04 06 B 123 2. 02 06 B 347 2. 02 ()8 G 100 2. 54 06 G 27 48 08 G 118 2. 78 06 H 100 2. 46 06 II 186 2. 40 08 II 269 2. 32 12 II 263 2. 38 06 K 100 2. 60 07 K 141 2. 72 07 1g 148 2. 74 08 Ix 2. 90 08 E 100 2. 46 06 E 214 2. 28 08 E 229 2. 22 06 E 339 2. 30 (JG 3 100 1. 96 06 C 355 2. 50 07 J 100 2. 46 08 J 151 2. 44 08 F 100 2. 38 09 F 692 1. 58 11 I 100 2. 52 08 I 309 2. 28 12 D 100 3. 10 08 D 204 2. 64 08 A 100 2. 62 08 A 132 2. 20 07 A 214 2. 30 48 A 100 2. 96 07 A 138 2. 45 06 Z 100 1. 28 05 A 100 1. 08 05 A 151 0. S4 04 S 100 1. 62 04 Y 407 0. 96 06 TABLE 4 Concentration compound No. I (g./mle Relative Example N0. silver) spee 7 Fog These data indicate that the optimum concentration of the addendum in the supersensitizing combinations of the invention are as previously mentioned generally in the range of about 0.3 to 1.0 g./mole of silver.

EXAMPLES 20 TO 44 These examples illustrate the supersensitization produced with the tetrazoles and tetrazolium salts in combination with various methine dyes coming under the defini tions of Formulas :IV to VI above. The testing procedure is exactly the same as that described in the preceding examples and the results are tabulated in similar manner in the following Table 5.

TABLE 5.SUPERSENSITIZATION BY TETRAZOLE TYPE COMPOUNDS [Addendum[ Addendum and cone.

Dye No. and superseusl- Example cone. (g./ tizer (gJmole Relative No. mole silver) silver) speed 7 Fog 20(a) A (0.053) 100 3.22 .07 A (0.053) 115 3. 06 06 P (0.05) 100 2.80 .08 P (0.05) 436 3.90 .33 P (0.038) 100 3. 90 .07 P (0.038) 269 5. 40 06 P (0.030) 100 2.82 .08 P (0.030) 251 4.15 .07 P (0.030) 148 3. 80 07 P (0.030) 355 3. 64 .07 D (0.03) 100 3. 28 07 D (0.03) 380 3. 24 06 D (0.03) 427 4. 40 T (0.04) 100 3. 44 06 T (0.04) 191 3. 12 05 S (0.015) 100 2. 80 06 S (0.015) 257 3. 05 S (0.015) 240 4. 60 06 U (0.015) 100 3. 04 08 U (0.015) 129 3. 60 05 R (0015) 100 3.04 .08 R (0.015) 186 2. 74 07 A (0.06) 100 2.90 07 A (0.06) 138 2. 80 07 L (0.08) 100 1. 06 L (0.08) 209 3. 06 M (0.08) 100 1. 30 .07 M (0.08) 178 3. 10 07 B (0.05) 100 1. 07 B (0.05) 631 3. 16 06 Q (0.033) 100 2. 50 05 Q (0033) 289 3. 26 06 X (0,04) 100 08 X (0.04) 1,200 3. 28 13 A (0.05) 100 2. 75 08 A(0.05) 141 2. 84 05 A (0.05) 151 2. 68 .07 O (0.115) 100 2. 16 06 C (0.115) 282 2. 98 06 O (0.115) 162 2.80 .05 B (0.080) 100 2.14 .07 B (0.080) 141 3.00 04 B (0.080) 151 2. 64 O (0.115) 100 2. 57 06 TABLE 5.-Continued Addendum and cone.

Dye N o. and supersensi- Example cone. (g./ tizer (g./mole Relative No mole silver) silver) speed 7 Fog O (0.115) 178 2. 44 04 O (0.115) 30!) 3. 18 03 0 (0.115) 513 3. 26 03 O (0.115) 417 3. 30 03 O (0.115) 166 2. 36 03 O (0.115) 219 2. 22 04 V (0.115) 100 3. 18 04 V (0.115) 155 3. 14 03 W (0.115) 100 1. 70 04 W (0.115) 110 2. 30 04 W (0.115) 132 3.18 03 v 0.1 100 2. 40 .03 V (0.1) 308 2. 70 03 C (0.12) 100 1. 47 03 C (0.12) 501 2. 04 03 B (0.1) 100 1. 03 B (0.1) 468 2.00 03 C (0.12) 100 1. 74 04 C (0.12) 347 2. 76 03 Y 0.070 100 Y 0.070) 290 It will be noted from above Table 5 that in each instance substantial improvement in relative speed over each dye alone is shown by the supersensitizing combinations of the invention.

EXAMPLES 45-57 These examples illustrate the supersensitization produced with the triazoles and imidazole compounds of the invention in combination with various methine dyes coming under the definitions of Formulas IV to VI above. The testing procedure is exactly the same as that described in the preceding examples and the results are tabulated in similar manner in the following Table 6.

TABLE 6.SUPERSENSITIZATION BY TRIAZOLE AND IMIDAZOLE TYPE COMPOUNDS {Addendum} Addendum Dye N 0. and and cone. Example cone. (g./ (g./m01e Relative N 0. mole silver) silver) speed '7 Fog Y 0.070 100 1. 32 00 Y 0.070 XXVII 0 as 0, 170 1. 40 .00 Y 0.070 None 100 1. 50 00 Y 0.070) XXVIII 1.0 0, 400 1.68 00 Y 0.070 XXIX 0.00 000 1. 33 .05 z 0.000 100 1.20 .05 2 0.000 XXXVI 0 a 101 1.18 .12 D 0.05% None 100 0. .04 D 0.053 xfg vn 430 1.10 .00 0. 05 None; 1.50 .04 0. 05 XXX 0 00)-- 1. 24 .04 (0. 04 None 100 1. 34 .05 0. 04 102 1. 15 .05

1 0.04 XX'Xvi 0.3 138 1.02 .14 1 0.04 XXv 186 0. 70 .05 1 0.01 XEgIVII 173 1.10 .05 Y 0.070) None 100 1.70 .00 Y 0. 070 5,750 1. 59 .00 Y 0.070 X%(()'X)VII 55,000 1.50 .05

.0 w 0. 070 None 100 1. 55 .04 w 0. 070 xggi vrr 132 1.40 .05 A 0.000 100 1. 0s .05 A 0.000 XXXVI 0 a 151 0.88 .25 Y 0. 070 None 100 0. 00 .04 Y 0. 070 10251 3111 1,380 1.48 .04 Y (0. 070 XX'XI'I 0.3 750 1.18 .04 Y 0. 070) XXXI 0.3 031 1. 74 .04 Y (0.076) None 100 1.00 .04 Y 0. 070 10251 7111 2, 240 1.18 .04. Y 0. 070) 5,510 1.24. .04

Referring to above Table 6, it will be observed that the relative speed for each of the specified supersensitizing combinations is markedly greater than that of the control 1 1 example containing the dye alone, i.e., without the supersensitizing addendum. Remarkably high relative speeds are shown for Example 46 (c) comprising Dye No. Y and addendum Compound No. XXIX, and Example 51(c) comprising Dye No. Y and addendum Compound No. XXXVII, with no increase in fog in each instance.

It will be apparent from all of the foregoing description that still other combinations of the invention can be produced by appropriate selection of other heterocyclic compounds of the type described herein with other photographic methine dyes and that such combinations likewise will result in supersensitized photographic silver halide emulsions.

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 described hereinabove and in the appended claims.

I claim:

1. A photographic silver halide emulsion containing a supersensitizing combination of (1) a heterocyclic compound having the following formula:

wherein R and R each represents a member selected from the group consisting of a hydrogen atom or an aryl group; and, R represents a member selected from the group consisting of hydrogen and amino; and (2) a photographic spectral sensitizing methine dye selected from those having one of the following formulas:

wherein n and e each represents a positive integer of from 1 to 2; d and In each represents a positive integer of from 1 to 3; R and R each represents a member selected from the group consisting of an alkyl group and an aryl group; X represents an acid anion; Z and Z each represents the non-metallic atoms necessary to complete a nucleus selected from the group consisting of a thiazole nucleus, an oxazole nucleus, a selenazole nucleus, a thiazoline nucleus, a pyridine nucleus, a 3,3-dialkyl-indolenine nucleus, a quinoline nucleus and an imidazole nucleus; L repre- 12 sents a methine linkage; and, Q represents the non-metallic atoms necessary to complete a heterocyclic ketomethylene nucleus selected from the group consisting of a 2-pyrazolin-S-one nucleus, an isoxazolone nucleus, an oxindole nucleus, a 2,4,6 triketohexahydropyrimidine nucleus, 21 rhodanine nucleus, a 2(3H)-imidazo[1,2-a]pyridone nucleus, a 5,7 dioxo-6,7-dihydro-5-thiazolo[3,2-a]pyrimidine nucleus, a 2 thio-2,4-oxazolidinedione nucleus, at thianaphthenone nucleus, a 2 thio-2,5-thiazolidinedione nucleus, a 2,4-thiazolidinedione nucleus, a thiazolidinone nucleus, a 2-thiaZolin-4-one nucleus, a 2-imino-4-oxazolidinone nucleus, a 2,4-imidazolidinedione nucleus, a 2-thio- 2,4-imidazolidinedione nucleus, and a 2-irnidazolin-5-one nucleus.

2. A photographic silver halide emulsion comprising a supersensitizing combination of (l) a heterocyclic compound selected from the group consisting of 3 -amino-5-phenyl-1,2,4-triazole,

3,3 -bis( 1,5 -diphenyl- 1 ,2,4-triazole 1,5 -diphenyl- 1 ,2,4-triazole,

4-amino-3,5-di-(p-aminophenyl)-1,2,4-triazole,

po1y(1,2,4-triazole),

4- S-cyanomethyll-phenyl- 1 ,2,4-triazol-3-yl benzaldehyde-N-chlorophenylhydrazone,

3,3 '-p-phenylenebis-(S-cyanomethyl-l-phenyl-1,2,4-

triazole and (2) a methine dye selected from the group consisting of 3,3-di-fl-hydroxyethylthiadicarbocyanine salt and 5-[di- (1 ethyl-2(1H-p-naphthothiazolylidene)isopropylidene]- 1,3-di({R-methoxyethyl)-barbituric acid.

3. A photographic silver halide emulsion comprising a supersensitizing combination of (1) the heterocyclic compound 1,5-diphenyl-1,2,4-triazole and 2) the methine dye 5-[di(l-ethyl-2(1H) ,8 naphthothiazolylidene)isopropylidene]-1,3-di-fl-rnethoxyethyl)-barbituric acid.

4. A photographic element comprising a support having a coating thereon containing an emulsion of claim 1.

5. A photographic element comprising a support having a coating thereon containing an emulsion of claim 2.

6. A photographic element comprising a support having a coating thereon containing an emulsion of claim 3.

References Cited UNITED STATES PATENTS 2,271,623 2/1942 Carroll 96104 2,566,167 8/1951 Carroll et a1 96104 2,680,686 6/1954 Van Dormael 96l04 3,255,012 6/1966 Glockner et al 9674 3,397,987 8/1968 Luckey et al. 96-l09 3,411,915 11/1968 Jones et al. 96104 3,420,664 1/1969 Dersch et al. 96109 3,457,078 7/1969 Riester 96-104 3,468,665 9/1969 Misu et al 96-74 I. TRAVIS BROWN, Primary Examiner U.S. Cl. X.R. 96109